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tailscale/derp/xdp/headers/bpf_helper_defs.h

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derp/xdp,cmd/xdpderper: initial skeleton (#12390) This commit introduces a userspace program for managing an experimental eBPF XDP STUN server program. derp/xdp contains the eBPF pseudo-C along with a Go pkg for loading it and exporting its metrics. cmd/xdpderper is a package main user of derp/xdp. Updates tailscale/corp#20689 Signed-off-by: Jordan Whited <jordan@tailscale.com>
2024-06-14 15:45:24 +00:00
/* This is auto-generated file. See bpf_doc.py for details. */
/* Forward declarations of BPF structs */
struct bpf_fib_lookup;
struct bpf_sk_lookup;
struct bpf_perf_event_data;
struct bpf_perf_event_value;
struct bpf_pidns_info;
struct bpf_redir_neigh;
struct bpf_sock;
struct bpf_sock_addr;
struct bpf_sock_ops;
struct bpf_sock_tuple;
struct bpf_spin_lock;
struct bpf_sysctl;
struct bpf_tcp_sock;
struct bpf_tunnel_key;
struct bpf_xfrm_state;
struct linux_binprm;
struct pt_regs;
struct sk_reuseport_md;
struct sockaddr;
struct tcphdr;
struct seq_file;
struct tcp6_sock;
struct tcp_sock;
struct tcp_timewait_sock;
struct tcp_request_sock;
struct udp6_sock;
struct unix_sock;
struct task_struct;
struct cgroup;
struct __sk_buff;
struct sk_msg_md;
struct xdp_md;
struct path;
struct btf_ptr;
struct inode;
struct socket;
struct file;
struct bpf_timer;
struct mptcp_sock;
struct bpf_dynptr;
struct iphdr;
struct ipv6hdr;
/*
* bpf_map_lookup_elem
*
* Perform a lookup in *map* for an entry associated to *key*.
*
* Returns
* Map value associated to *key*, or **NULL** if no entry was
* found.
*/
static void *(* const bpf_map_lookup_elem)(void *map, const void *key) = (void *) 1;
/*
* bpf_map_update_elem
*
* Add or update the value of the entry associated to *key* in
* *map* with *value*. *flags* is one of:
*
* **BPF_NOEXIST**
* The entry for *key* must not exist in the map.
* **BPF_EXIST**
* The entry for *key* must already exist in the map.
* **BPF_ANY**
* No condition on the existence of the entry for *key*.
*
* Flag value **BPF_NOEXIST** cannot be used for maps of types
* **BPF_MAP_TYPE_ARRAY** or **BPF_MAP_TYPE_PERCPU_ARRAY** (all
* elements always exist), the helper would return an error.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_map_update_elem)(void *map, const void *key, const void *value, __u64 flags) = (void *) 2;
/*
* bpf_map_delete_elem
*
* Delete entry with *key* from *map*.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_map_delete_elem)(void *map, const void *key) = (void *) 3;
/*
* bpf_probe_read
*
* For tracing programs, safely attempt to read *size* bytes from
* kernel space address *unsafe_ptr* and store the data in *dst*.
*
* Generally, use **bpf_probe_read_user**\ () or
* **bpf_probe_read_kernel**\ () instead.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_probe_read)(void *dst, __u32 size, const void *unsafe_ptr) = (void *) 4;
/*
* bpf_ktime_get_ns
*
* Return the time elapsed since system boot, in nanoseconds.
* Does not include time the system was suspended.
* See: **clock_gettime**\ (**CLOCK_MONOTONIC**)
*
* Returns
* Current *ktime*.
*/
static __u64 (* const bpf_ktime_get_ns)(void) = (void *) 5;
/*
* bpf_trace_printk
*
* This helper is a "printk()-like" facility for debugging. It
* prints a message defined by format *fmt* (of size *fmt_size*)
* to file *\/sys/kernel/tracing/trace* from TraceFS, if
* available. It can take up to three additional **u64**
* arguments (as an eBPF helpers, the total number of arguments is
* limited to five).
*
* Each time the helper is called, it appends a line to the trace.
* Lines are discarded while *\/sys/kernel/tracing/trace* is
* open, use *\/sys/kernel/tracing/trace_pipe* to avoid this.
* The format of the trace is customizable, and the exact output
* one will get depends on the options set in
* *\/sys/kernel/tracing/trace_options* (see also the
* *README* file under the same directory). However, it usually
* defaults to something like:
*
* ::
*
* telnet-470 [001] .N.. 419421.045894: 0x00000001: <formatted msg>
*
* In the above:
*
* * ``telnet`` is the name of the current task.
* * ``470`` is the PID of the current task.
* * ``001`` is the CPU number on which the task is
* running.
* * In ``.N..``, each character refers to a set of
* options (whether irqs are enabled, scheduling
* options, whether hard/softirqs are running, level of
* preempt_disabled respectively). **N** means that
* **TIF_NEED_RESCHED** and **PREEMPT_NEED_RESCHED**
* are set.
* * ``419421.045894`` is a timestamp.
* * ``0x00000001`` is a fake value used by BPF for the
* instruction pointer register.
* * ``<formatted msg>`` is the message formatted with
* *fmt*.
*
* The conversion specifiers supported by *fmt* are similar, but
* more limited than for printk(). They are **%d**, **%i**,
* **%u**, **%x**, **%ld**, **%li**, **%lu**, **%lx**, **%lld**,
* **%lli**, **%llu**, **%llx**, **%p**, **%s**. No modifier (size
* of field, padding with zeroes, etc.) is available, and the
* helper will return **-EINVAL** (but print nothing) if it
* encounters an unknown specifier.
*
* Also, note that **bpf_trace_printk**\ () is slow, and should
* only be used for debugging purposes. For this reason, a notice
* block (spanning several lines) is printed to kernel logs and
* states that the helper should not be used "for production use"
* the first time this helper is used (or more precisely, when
* **trace_printk**\ () buffers are allocated). For passing values
* to user space, perf events should be preferred.
*
* Returns
* The number of bytes written to the buffer, or a negative error
* in case of failure.
*/
static long (* const bpf_trace_printk)(const char *fmt, __u32 fmt_size, ...) = (void *) 6;
/*
* bpf_get_prandom_u32
*
* Get a pseudo-random number.
*
* From a security point of view, this helper uses its own
* pseudo-random internal state, and cannot be used to infer the
* seed of other random functions in the kernel. However, it is
* essential to note that the generator used by the helper is not
* cryptographically secure.
*
* Returns
* A random 32-bit unsigned value.
*/
static __u32 (* const bpf_get_prandom_u32)(void) = (void *) 7;
/*
* bpf_get_smp_processor_id
*
* Get the SMP (symmetric multiprocessing) processor id. Note that
* all programs run with migration disabled, which means that the
* SMP processor id is stable during all the execution of the
* program.
*
* Returns
* The SMP id of the processor running the program.
*/
static __u32 (* const bpf_get_smp_processor_id)(void) = (void *) 8;
/*
* bpf_skb_store_bytes
*
* Store *len* bytes from address *from* into the packet
* associated to *skb*, at *offset*. *flags* are a combination of
* **BPF_F_RECOMPUTE_CSUM** (automatically recompute the
* checksum for the packet after storing the bytes) and
* **BPF_F_INVALIDATE_HASH** (set *skb*\ **->hash**, *skb*\
* **->swhash** and *skb*\ **->l4hash** to 0).
*
* A call to this helper is susceptible to change the underlying
* packet buffer. Therefore, at load time, all checks on pointers
* previously done by the verifier are invalidated and must be
* performed again, if the helper is used in combination with
* direct packet access.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_skb_store_bytes)(struct __sk_buff *skb, __u32 offset, const void *from, __u32 len, __u64 flags) = (void *) 9;
/*
* bpf_l3_csum_replace
*
* Recompute the layer 3 (e.g. IP) checksum for the packet
* associated to *skb*. Computation is incremental, so the helper
* must know the former value of the header field that was
* modified (*from*), the new value of this field (*to*), and the
* number of bytes (2 or 4) for this field, stored in *size*.
* Alternatively, it is possible to store the difference between
* the previous and the new values of the header field in *to*, by
* setting *from* and *size* to 0. For both methods, *offset*
* indicates the location of the IP checksum within the packet.
*
* This helper works in combination with **bpf_csum_diff**\ (),
* which does not update the checksum in-place, but offers more
* flexibility and can handle sizes larger than 2 or 4 for the
* checksum to update.
*
* A call to this helper is susceptible to change the underlying
* packet buffer. Therefore, at load time, all checks on pointers
* previously done by the verifier are invalidated and must be
* performed again, if the helper is used in combination with
* direct packet access.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_l3_csum_replace)(struct __sk_buff *skb, __u32 offset, __u64 from, __u64 to, __u64 size) = (void *) 10;
/*
* bpf_l4_csum_replace
*
* Recompute the layer 4 (e.g. TCP, UDP or ICMP) checksum for the
* packet associated to *skb*. Computation is incremental, so the
* helper must know the former value of the header field that was
* modified (*from*), the new value of this field (*to*), and the
* number of bytes (2 or 4) for this field, stored on the lowest
* four bits of *flags*. Alternatively, it is possible to store
* the difference between the previous and the new values of the
* header field in *to*, by setting *from* and the four lowest
* bits of *flags* to 0. For both methods, *offset* indicates the
* location of the IP checksum within the packet. In addition to
* the size of the field, *flags* can be added (bitwise OR) actual
* flags. With **BPF_F_MARK_MANGLED_0**, a null checksum is left
* untouched (unless **BPF_F_MARK_ENFORCE** is added as well), and
* for updates resulting in a null checksum the value is set to
* **CSUM_MANGLED_0** instead. Flag **BPF_F_PSEUDO_HDR** indicates
* the checksum is to be computed against a pseudo-header.
*
* This helper works in combination with **bpf_csum_diff**\ (),
* which does not update the checksum in-place, but offers more
* flexibility and can handle sizes larger than 2 or 4 for the
* checksum to update.
*
* A call to this helper is susceptible to change the underlying
* packet buffer. Therefore, at load time, all checks on pointers
* previously done by the verifier are invalidated and must be
* performed again, if the helper is used in combination with
* direct packet access.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_l4_csum_replace)(struct __sk_buff *skb, __u32 offset, __u64 from, __u64 to, __u64 flags) = (void *) 11;
/*
* bpf_tail_call
*
* This special helper is used to trigger a "tail call", or in
* other words, to jump into another eBPF program. The same stack
* frame is used (but values on stack and in registers for the
* caller are not accessible to the callee). This mechanism allows
* for program chaining, either for raising the maximum number of
* available eBPF instructions, or to execute given programs in
* conditional blocks. For security reasons, there is an upper
* limit to the number of successive tail calls that can be
* performed.
*
* Upon call of this helper, the program attempts to jump into a
* program referenced at index *index* in *prog_array_map*, a
* special map of type **BPF_MAP_TYPE_PROG_ARRAY**, and passes
* *ctx*, a pointer to the context.
*
* If the call succeeds, the kernel immediately runs the first
* instruction of the new program. This is not a function call,
* and it never returns to the previous program. If the call
* fails, then the helper has no effect, and the caller continues
* to run its subsequent instructions. A call can fail if the
* destination program for the jump does not exist (i.e. *index*
* is superior to the number of entries in *prog_array_map*), or
* if the maximum number of tail calls has been reached for this
* chain of programs. This limit is defined in the kernel by the
* macro **MAX_TAIL_CALL_CNT** (not accessible to user space),
* which is currently set to 33.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_tail_call)(void *ctx, void *prog_array_map, __u32 index) = (void *) 12;
/*
* bpf_clone_redirect
*
* Clone and redirect the packet associated to *skb* to another
* net device of index *ifindex*. Both ingress and egress
* interfaces can be used for redirection. The **BPF_F_INGRESS**
* value in *flags* is used to make the distinction (ingress path
* is selected if the flag is present, egress path otherwise).
* This is the only flag supported for now.
*
* In comparison with **bpf_redirect**\ () helper,
* **bpf_clone_redirect**\ () has the associated cost of
* duplicating the packet buffer, but this can be executed out of
* the eBPF program. Conversely, **bpf_redirect**\ () is more
* efficient, but it is handled through an action code where the
* redirection happens only after the eBPF program has returned.
*
* A call to this helper is susceptible to change the underlying
* packet buffer. Therefore, at load time, all checks on pointers
* previously done by the verifier are invalidated and must be
* performed again, if the helper is used in combination with
* direct packet access.
*
* Returns
* 0 on success, or a negative error in case of failure. Positive
* error indicates a potential drop or congestion in the target
* device. The particular positive error codes are not defined.
*/
static long (* const bpf_clone_redirect)(struct __sk_buff *skb, __u32 ifindex, __u64 flags) = (void *) 13;
/*
* bpf_get_current_pid_tgid
*
* Get the current pid and tgid.
*
* Returns
* A 64-bit integer containing the current tgid and pid, and
* created as such:
* *current_task*\ **->tgid << 32 \|**
* *current_task*\ **->pid**.
*/
static __u64 (* const bpf_get_current_pid_tgid)(void) = (void *) 14;
/*
* bpf_get_current_uid_gid
*
* Get the current uid and gid.
*
* Returns
* A 64-bit integer containing the current GID and UID, and
* created as such: *current_gid* **<< 32 \|** *current_uid*.
*/
static __u64 (* const bpf_get_current_uid_gid)(void) = (void *) 15;
/*
* bpf_get_current_comm
*
* Copy the **comm** attribute of the current task into *buf* of
* *size_of_buf*. The **comm** attribute contains the name of
* the executable (excluding the path) for the current task. The
* *size_of_buf* must be strictly positive. On success, the
* helper makes sure that the *buf* is NUL-terminated. On failure,
* it is filled with zeroes.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_get_current_comm)(void *buf, __u32 size_of_buf) = (void *) 16;
/*
* bpf_get_cgroup_classid
*
* Retrieve the classid for the current task, i.e. for the net_cls
* cgroup to which *skb* belongs.
*
* This helper can be used on TC egress path, but not on ingress.
*
* The net_cls cgroup provides an interface to tag network packets
* based on a user-provided identifier for all traffic coming from
* the tasks belonging to the related cgroup. See also the related
* kernel documentation, available from the Linux sources in file
* *Documentation/admin-guide/cgroup-v1/net_cls.rst*.
*
* The Linux kernel has two versions for cgroups: there are
* cgroups v1 and cgroups v2. Both are available to users, who can
* use a mixture of them, but note that the net_cls cgroup is for
* cgroup v1 only. This makes it incompatible with BPF programs
* run on cgroups, which is a cgroup-v2-only feature (a socket can
* only hold data for one version of cgroups at a time).
*
* This helper is only available is the kernel was compiled with
* the **CONFIG_CGROUP_NET_CLASSID** configuration option set to
* "**y**" or to "**m**".
*
* Returns
* The classid, or 0 for the default unconfigured classid.
*/
static __u32 (* const bpf_get_cgroup_classid)(struct __sk_buff *skb) = (void *) 17;
/*
* bpf_skb_vlan_push
*
* Push a *vlan_tci* (VLAN tag control information) of protocol
* *vlan_proto* to the packet associated to *skb*, then update
* the checksum. Note that if *vlan_proto* is different from
* **ETH_P_8021Q** and **ETH_P_8021AD**, it is considered to
* be **ETH_P_8021Q**.
*
* A call to this helper is susceptible to change the underlying
* packet buffer. Therefore, at load time, all checks on pointers
* previously done by the verifier are invalidated and must be
* performed again, if the helper is used in combination with
* direct packet access.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_skb_vlan_push)(struct __sk_buff *skb, __be16 vlan_proto, __u16 vlan_tci) = (void *) 18;
/*
* bpf_skb_vlan_pop
*
* Pop a VLAN header from the packet associated to *skb*.
*
* A call to this helper is susceptible to change the underlying
* packet buffer. Therefore, at load time, all checks on pointers
* previously done by the verifier are invalidated and must be
* performed again, if the helper is used in combination with
* direct packet access.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_skb_vlan_pop)(struct __sk_buff *skb) = (void *) 19;
/*
* bpf_skb_get_tunnel_key
*
* Get tunnel metadata. This helper takes a pointer *key* to an
* empty **struct bpf_tunnel_key** of **size**, that will be
* filled with tunnel metadata for the packet associated to *skb*.
* The *flags* can be set to **BPF_F_TUNINFO_IPV6**, which
* indicates that the tunnel is based on IPv6 protocol instead of
* IPv4.
*
* The **struct bpf_tunnel_key** is an object that generalizes the
* principal parameters used by various tunneling protocols into a
* single struct. This way, it can be used to easily make a
* decision based on the contents of the encapsulation header,
* "summarized" in this struct. In particular, it holds the IP
* address of the remote end (IPv4 or IPv6, depending on the case)
* in *key*\ **->remote_ipv4** or *key*\ **->remote_ipv6**. Also,
* this struct exposes the *key*\ **->tunnel_id**, which is
* generally mapped to a VNI (Virtual Network Identifier), making
* it programmable together with the **bpf_skb_set_tunnel_key**\
* () helper.
*
* Let's imagine that the following code is part of a program
* attached to the TC ingress interface, on one end of a GRE
* tunnel, and is supposed to filter out all messages coming from
* remote ends with IPv4 address other than 10.0.0.1:
*
* ::
*
* int ret;
* struct bpf_tunnel_key key = {};
*
* ret = bpf_skb_get_tunnel_key(skb, &key, sizeof(key), 0);
* if (ret < 0)
* return TC_ACT_SHOT; // drop packet
*
* if (key.remote_ipv4 != 0x0a000001)
* return TC_ACT_SHOT; // drop packet
*
* return TC_ACT_OK; // accept packet
*
* This interface can also be used with all encapsulation devices
* that can operate in "collect metadata" mode: instead of having
* one network device per specific configuration, the "collect
* metadata" mode only requires a single device where the
* configuration can be extracted from this helper.
*
* This can be used together with various tunnels such as VXLan,
* Geneve, GRE or IP in IP (IPIP).
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_skb_get_tunnel_key)(struct __sk_buff *skb, struct bpf_tunnel_key *key, __u32 size, __u64 flags) = (void *) 20;
/*
* bpf_skb_set_tunnel_key
*
* Populate tunnel metadata for packet associated to *skb.* The
* tunnel metadata is set to the contents of *key*, of *size*. The
* *flags* can be set to a combination of the following values:
*
* **BPF_F_TUNINFO_IPV6**
* Indicate that the tunnel is based on IPv6 protocol
* instead of IPv4.
* **BPF_F_ZERO_CSUM_TX**
* For IPv4 packets, add a flag to tunnel metadata
* indicating that checksum computation should be skipped
* and checksum set to zeroes.
* **BPF_F_DONT_FRAGMENT**
* Add a flag to tunnel metadata indicating that the
* packet should not be fragmented.
* **BPF_F_SEQ_NUMBER**
* Add a flag to tunnel metadata indicating that a
* sequence number should be added to tunnel header before
* sending the packet. This flag was added for GRE
* encapsulation, but might be used with other protocols
* as well in the future.
* **BPF_F_NO_TUNNEL_KEY**
* Add a flag to tunnel metadata indicating that no tunnel
* key should be set in the resulting tunnel header.
*
* Here is a typical usage on the transmit path:
*
* ::
*
* struct bpf_tunnel_key key;
* populate key ...
* bpf_skb_set_tunnel_key(skb, &key, sizeof(key), 0);
* bpf_clone_redirect(skb, vxlan_dev_ifindex, 0);
*
* See also the description of the **bpf_skb_get_tunnel_key**\ ()
* helper for additional information.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_skb_set_tunnel_key)(struct __sk_buff *skb, struct bpf_tunnel_key *key, __u32 size, __u64 flags) = (void *) 21;
/*
* bpf_perf_event_read
*
* Read the value of a perf event counter. This helper relies on a
* *map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. The nature of
* the perf event counter is selected when *map* is updated with
* perf event file descriptors. The *map* is an array whose size
* is the number of available CPUs, and each cell contains a value
* relative to one CPU. The value to retrieve is indicated by
* *flags*, that contains the index of the CPU to look up, masked
* with **BPF_F_INDEX_MASK**. Alternatively, *flags* can be set to
* **BPF_F_CURRENT_CPU** to indicate that the value for the
* current CPU should be retrieved.
*
* Note that before Linux 4.13, only hardware perf event can be
* retrieved.
*
* Also, be aware that the newer helper
* **bpf_perf_event_read_value**\ () is recommended over
* **bpf_perf_event_read**\ () in general. The latter has some ABI
* quirks where error and counter value are used as a return code
* (which is wrong to do since ranges may overlap). This issue is
* fixed with **bpf_perf_event_read_value**\ (), which at the same
* time provides more features over the **bpf_perf_event_read**\
* () interface. Please refer to the description of
* **bpf_perf_event_read_value**\ () for details.
*
* Returns
* The value of the perf event counter read from the map, or a
* negative error code in case of failure.
*/
static __u64 (* const bpf_perf_event_read)(void *map, __u64 flags) = (void *) 22;
/*
* bpf_redirect
*
* Redirect the packet to another net device of index *ifindex*.
* This helper is somewhat similar to **bpf_clone_redirect**\
* (), except that the packet is not cloned, which provides
* increased performance.
*
* Except for XDP, both ingress and egress interfaces can be used
* for redirection. The **BPF_F_INGRESS** value in *flags* is used
* to make the distinction (ingress path is selected if the flag
* is present, egress path otherwise). Currently, XDP only
* supports redirection to the egress interface, and accepts no
* flag at all.
*
* The same effect can also be attained with the more generic
* **bpf_redirect_map**\ (), which uses a BPF map to store the
* redirect target instead of providing it directly to the helper.
*
* Returns
* For XDP, the helper returns **XDP_REDIRECT** on success or
* **XDP_ABORTED** on error. For other program types, the values
* are **TC_ACT_REDIRECT** on success or **TC_ACT_SHOT** on
* error.
*/
static long (* const bpf_redirect)(__u32 ifindex, __u64 flags) = (void *) 23;
/*
* bpf_get_route_realm
*
* Retrieve the realm or the route, that is to say the
* **tclassid** field of the destination for the *skb*. The
* identifier retrieved is a user-provided tag, similar to the
* one used with the net_cls cgroup (see description for
* **bpf_get_cgroup_classid**\ () helper), but here this tag is
* held by a route (a destination entry), not by a task.
*
* Retrieving this identifier works with the clsact TC egress hook
* (see also **tc-bpf(8)**), or alternatively on conventional
* classful egress qdiscs, but not on TC ingress path. In case of
* clsact TC egress hook, this has the advantage that, internally,
* the destination entry has not been dropped yet in the transmit
* path. Therefore, the destination entry does not need to be
* artificially held via **netif_keep_dst**\ () for a classful
* qdisc until the *skb* is freed.
*
* This helper is available only if the kernel was compiled with
* **CONFIG_IP_ROUTE_CLASSID** configuration option.
*
* Returns
* The realm of the route for the packet associated to *skb*, or 0
* if none was found.
*/
static __u32 (* const bpf_get_route_realm)(struct __sk_buff *skb) = (void *) 24;
/*
* bpf_perf_event_output
*
* Write raw *data* blob into a special BPF perf event held by
* *map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. This perf
* event must have the following attributes: **PERF_SAMPLE_RAW**
* as **sample_type**, **PERF_TYPE_SOFTWARE** as **type**, and
* **PERF_COUNT_SW_BPF_OUTPUT** as **config**.
*
* The *flags* are used to indicate the index in *map* for which
* the value must be put, masked with **BPF_F_INDEX_MASK**.
* Alternatively, *flags* can be set to **BPF_F_CURRENT_CPU**
* to indicate that the index of the current CPU core should be
* used.
*
* The value to write, of *size*, is passed through eBPF stack and
* pointed by *data*.
*
* The context of the program *ctx* needs also be passed to the
* helper.
*
* On user space, a program willing to read the values needs to
* call **perf_event_open**\ () on the perf event (either for
* one or for all CPUs) and to store the file descriptor into the
* *map*. This must be done before the eBPF program can send data
* into it. An example is available in file
* *samples/bpf/trace_output_user.c* in the Linux kernel source
* tree (the eBPF program counterpart is in
* *samples/bpf/trace_output_kern.c*).
*
* **bpf_perf_event_output**\ () achieves better performance
* than **bpf_trace_printk**\ () for sharing data with user
* space, and is much better suitable for streaming data from eBPF
* programs.
*
* Note that this helper is not restricted to tracing use cases
* and can be used with programs attached to TC or XDP as well,
* where it allows for passing data to user space listeners. Data
* can be:
*
* * Only custom structs,
* * Only the packet payload, or
* * A combination of both.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_perf_event_output)(void *ctx, void *map, __u64 flags, void *data, __u64 size) = (void *) 25;
/*
* bpf_skb_load_bytes
*
* This helper was provided as an easy way to load data from a
* packet. It can be used to load *len* bytes from *offset* from
* the packet associated to *skb*, into the buffer pointed by
* *to*.
*
* Since Linux 4.7, usage of this helper has mostly been replaced
* by "direct packet access", enabling packet data to be
* manipulated with *skb*\ **->data** and *skb*\ **->data_end**
* pointing respectively to the first byte of packet data and to
* the byte after the last byte of packet data. However, it
* remains useful if one wishes to read large quantities of data
* at once from a packet into the eBPF stack.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_skb_load_bytes)(const void *skb, __u32 offset, void *to, __u32 len) = (void *) 26;
/*
* bpf_get_stackid
*
* Walk a user or a kernel stack and return its id. To achieve
* this, the helper needs *ctx*, which is a pointer to the context
* on which the tracing program is executed, and a pointer to a
* *map* of type **BPF_MAP_TYPE_STACK_TRACE**.
*
* The last argument, *flags*, holds the number of stack frames to
* skip (from 0 to 255), masked with
* **BPF_F_SKIP_FIELD_MASK**. The next bits can be used to set
* a combination of the following flags:
*
* **BPF_F_USER_STACK**
* Collect a user space stack instead of a kernel stack.
* **BPF_F_FAST_STACK_CMP**
* Compare stacks by hash only.
* **BPF_F_REUSE_STACKID**
* If two different stacks hash into the same *stackid*,
* discard the old one.
*
* The stack id retrieved is a 32 bit long integer handle which
* can be further combined with other data (including other stack
* ids) and used as a key into maps. This can be useful for
* generating a variety of graphs (such as flame graphs or off-cpu
* graphs).
*
* For walking a stack, this helper is an improvement over
* **bpf_probe_read**\ (), which can be used with unrolled loops
* but is not efficient and consumes a lot of eBPF instructions.
* Instead, **bpf_get_stackid**\ () can collect up to
* **PERF_MAX_STACK_DEPTH** both kernel and user frames. Note that
* this limit can be controlled with the **sysctl** program, and
* that it should be manually increased in order to profile long
* user stacks (such as stacks for Java programs). To do so, use:
*
* ::
*
* # sysctl kernel.perf_event_max_stack=<new value>
*
* Returns
* The positive or null stack id on success, or a negative error
* in case of failure.
*/
static long (* const bpf_get_stackid)(void *ctx, void *map, __u64 flags) = (void *) 27;
/*
* bpf_csum_diff
*
* Compute a checksum difference, from the raw buffer pointed by
* *from*, of length *from_size* (that must be a multiple of 4),
* towards the raw buffer pointed by *to*, of size *to_size*
* (same remark). An optional *seed* can be added to the value
* (this can be cascaded, the seed may come from a previous call
* to the helper).
*
* This is flexible enough to be used in several ways:
*
* * With *from_size* == 0, *to_size* > 0 and *seed* set to
* checksum, it can be used when pushing new data.
* * With *from_size* > 0, *to_size* == 0 and *seed* set to
* checksum, it can be used when removing data from a packet.
* * With *from_size* > 0, *to_size* > 0 and *seed* set to 0, it
* can be used to compute a diff. Note that *from_size* and
* *to_size* do not need to be equal.
*
* This helper can be used in combination with
* **bpf_l3_csum_replace**\ () and **bpf_l4_csum_replace**\ (), to
* which one can feed in the difference computed with
* **bpf_csum_diff**\ ().
*
* Returns
* The checksum result, or a negative error code in case of
* failure.
*/
static __s64 (* const bpf_csum_diff)(__be32 *from, __u32 from_size, __be32 *to, __u32 to_size, __wsum seed) = (void *) 28;
/*
* bpf_skb_get_tunnel_opt
*
* Retrieve tunnel options metadata for the packet associated to
* *skb*, and store the raw tunnel option data to the buffer *opt*
* of *size*.
*
* This helper can be used with encapsulation devices that can
* operate in "collect metadata" mode (please refer to the related
* note in the description of **bpf_skb_get_tunnel_key**\ () for
* more details). A particular example where this can be used is
* in combination with the Geneve encapsulation protocol, where it
* allows for pushing (with **bpf_skb_get_tunnel_opt**\ () helper)
* and retrieving arbitrary TLVs (Type-Length-Value headers) from
* the eBPF program. This allows for full customization of these
* headers.
*
* Returns
* The size of the option data retrieved.
*/
static long (* const bpf_skb_get_tunnel_opt)(struct __sk_buff *skb, void *opt, __u32 size) = (void *) 29;
/*
* bpf_skb_set_tunnel_opt
*
* Set tunnel options metadata for the packet associated to *skb*
* to the option data contained in the raw buffer *opt* of *size*.
*
* See also the description of the **bpf_skb_get_tunnel_opt**\ ()
* helper for additional information.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_skb_set_tunnel_opt)(struct __sk_buff *skb, void *opt, __u32 size) = (void *) 30;
/*
* bpf_skb_change_proto
*
* Change the protocol of the *skb* to *proto*. Currently
* supported are transition from IPv4 to IPv6, and from IPv6 to
* IPv4. The helper takes care of the groundwork for the
* transition, including resizing the socket buffer. The eBPF
* program is expected to fill the new headers, if any, via
* **skb_store_bytes**\ () and to recompute the checksums with
* **bpf_l3_csum_replace**\ () and **bpf_l4_csum_replace**\
* (). The main case for this helper is to perform NAT64
* operations out of an eBPF program.
*
* Internally, the GSO type is marked as dodgy so that headers are
* checked and segments are recalculated by the GSO/GRO engine.
* The size for GSO target is adapted as well.
*
* All values for *flags* are reserved for future usage, and must
* be left at zero.
*
* A call to this helper is susceptible to change the underlying
* packet buffer. Therefore, at load time, all checks on pointers
* previously done by the verifier are invalidated and must be
* performed again, if the helper is used in combination with
* direct packet access.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_skb_change_proto)(struct __sk_buff *skb, __be16 proto, __u64 flags) = (void *) 31;
/*
* bpf_skb_change_type
*
* Change the packet type for the packet associated to *skb*. This
* comes down to setting *skb*\ **->pkt_type** to *type*, except
* the eBPF program does not have a write access to *skb*\
* **->pkt_type** beside this helper. Using a helper here allows
* for graceful handling of errors.
*
* The major use case is to change incoming *skb*s to
* **PACKET_HOST** in a programmatic way instead of having to
* recirculate via **redirect**\ (..., **BPF_F_INGRESS**), for
* example.
*
* Note that *type* only allows certain values. At this time, they
* are:
*
* **PACKET_HOST**
* Packet is for us.
* **PACKET_BROADCAST**
* Send packet to all.
* **PACKET_MULTICAST**
* Send packet to group.
* **PACKET_OTHERHOST**
* Send packet to someone else.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_skb_change_type)(struct __sk_buff *skb, __u32 type) = (void *) 32;
/*
* bpf_skb_under_cgroup
*
* Check whether *skb* is a descendant of the cgroup2 held by
* *map* of type **BPF_MAP_TYPE_CGROUP_ARRAY**, at *index*.
*
* Returns
* The return value depends on the result of the test, and can be:
*
* * 0, if the *skb* failed the cgroup2 descendant test.
* * 1, if the *skb* succeeded the cgroup2 descendant test.
* * A negative error code, if an error occurred.
*/
static long (* const bpf_skb_under_cgroup)(struct __sk_buff *skb, void *map, __u32 index) = (void *) 33;
/*
* bpf_get_hash_recalc
*
* Retrieve the hash of the packet, *skb*\ **->hash**. If it is
* not set, in particular if the hash was cleared due to mangling,
* recompute this hash. Later accesses to the hash can be done
* directly with *skb*\ **->hash**.
*
* Calling **bpf_set_hash_invalid**\ (), changing a packet
* prototype with **bpf_skb_change_proto**\ (), or calling
* **bpf_skb_store_bytes**\ () with the
* **BPF_F_INVALIDATE_HASH** are actions susceptible to clear
* the hash and to trigger a new computation for the next call to
* **bpf_get_hash_recalc**\ ().
*
* Returns
* The 32-bit hash.
*/
static __u32 (* const bpf_get_hash_recalc)(struct __sk_buff *skb) = (void *) 34;
/*
* bpf_get_current_task
*
* Get the current task.
*
* Returns
* A pointer to the current task struct.
*/
static __u64 (* const bpf_get_current_task)(void) = (void *) 35;
/*
* bpf_probe_write_user
*
* Attempt in a safe way to write *len* bytes from the buffer
* *src* to *dst* in memory. It only works for threads that are in
* user context, and *dst* must be a valid user space address.
*
* This helper should not be used to implement any kind of
* security mechanism because of TOC-TOU attacks, but rather to
* debug, divert, and manipulate execution of semi-cooperative
* processes.
*
* Keep in mind that this feature is meant for experiments, and it
* has a risk of crashing the system and running programs.
* Therefore, when an eBPF program using this helper is attached,
* a warning including PID and process name is printed to kernel
* logs.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_probe_write_user)(void *dst, const void *src, __u32 len) = (void *) 36;
/*
* bpf_current_task_under_cgroup
*
* Check whether the probe is being run is the context of a given
* subset of the cgroup2 hierarchy. The cgroup2 to test is held by
* *map* of type **BPF_MAP_TYPE_CGROUP_ARRAY**, at *index*.
*
* Returns
* The return value depends on the result of the test, and can be:
*
* * 1, if current task belongs to the cgroup2.
* * 0, if current task does not belong to the cgroup2.
* * A negative error code, if an error occurred.
*/
static long (* const bpf_current_task_under_cgroup)(void *map, __u32 index) = (void *) 37;
/*
* bpf_skb_change_tail
*
* Resize (trim or grow) the packet associated to *skb* to the
* new *len*. The *flags* are reserved for future usage, and must
* be left at zero.
*
* The basic idea is that the helper performs the needed work to
* change the size of the packet, then the eBPF program rewrites
* the rest via helpers like **bpf_skb_store_bytes**\ (),
* **bpf_l3_csum_replace**\ (), **bpf_l3_csum_replace**\ ()
* and others. This helper is a slow path utility intended for
* replies with control messages. And because it is targeted for
* slow path, the helper itself can afford to be slow: it
* implicitly linearizes, unclones and drops offloads from the
* *skb*.
*
* A call to this helper is susceptible to change the underlying
* packet buffer. Therefore, at load time, all checks on pointers
* previously done by the verifier are invalidated and must be
* performed again, if the helper is used in combination with
* direct packet access.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_skb_change_tail)(struct __sk_buff *skb, __u32 len, __u64 flags) = (void *) 38;
/*
* bpf_skb_pull_data
*
* Pull in non-linear data in case the *skb* is non-linear and not
* all of *len* are part of the linear section. Make *len* bytes
* from *skb* readable and writable. If a zero value is passed for
* *len*, then all bytes in the linear part of *skb* will be made
* readable and writable.
*
* This helper is only needed for reading and writing with direct
* packet access.
*
* For direct packet access, testing that offsets to access
* are within packet boundaries (test on *skb*\ **->data_end**) is
* susceptible to fail if offsets are invalid, or if the requested
* data is in non-linear parts of the *skb*. On failure the
* program can just bail out, or in the case of a non-linear
* buffer, use a helper to make the data available. The
* **bpf_skb_load_bytes**\ () helper is a first solution to access
* the data. Another one consists in using **bpf_skb_pull_data**
* to pull in once the non-linear parts, then retesting and
* eventually access the data.
*
* At the same time, this also makes sure the *skb* is uncloned,
* which is a necessary condition for direct write. As this needs
* to be an invariant for the write part only, the verifier
* detects writes and adds a prologue that is calling
* **bpf_skb_pull_data()** to effectively unclone the *skb* from
* the very beginning in case it is indeed cloned.
*
* A call to this helper is susceptible to change the underlying
* packet buffer. Therefore, at load time, all checks on pointers
* previously done by the verifier are invalidated and must be
* performed again, if the helper is used in combination with
* direct packet access.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_skb_pull_data)(struct __sk_buff *skb, __u32 len) = (void *) 39;
/*
* bpf_csum_update
*
* Add the checksum *csum* into *skb*\ **->csum** in case the
* driver has supplied a checksum for the entire packet into that
* field. Return an error otherwise. This helper is intended to be
* used in combination with **bpf_csum_diff**\ (), in particular
* when the checksum needs to be updated after data has been
* written into the packet through direct packet access.
*
* Returns
* The checksum on success, or a negative error code in case of
* failure.
*/
static __s64 (* const bpf_csum_update)(struct __sk_buff *skb, __wsum csum) = (void *) 40;
/*
* bpf_set_hash_invalid
*
* Invalidate the current *skb*\ **->hash**. It can be used after
* mangling on headers through direct packet access, in order to
* indicate that the hash is outdated and to trigger a
* recalculation the next time the kernel tries to access this
* hash or when the **bpf_get_hash_recalc**\ () helper is called.
*
* Returns
* void.
*/
static void (* const bpf_set_hash_invalid)(struct __sk_buff *skb) = (void *) 41;
/*
* bpf_get_numa_node_id
*
* Return the id of the current NUMA node. The primary use case
* for this helper is the selection of sockets for the local NUMA
* node, when the program is attached to sockets using the
* **SO_ATTACH_REUSEPORT_EBPF** option (see also **socket(7)**),
* but the helper is also available to other eBPF program types,
* similarly to **bpf_get_smp_processor_id**\ ().
*
* Returns
* The id of current NUMA node.
*/
static long (* const bpf_get_numa_node_id)(void) = (void *) 42;
/*
* bpf_skb_change_head
*
* Grows headroom of packet associated to *skb* and adjusts the
* offset of the MAC header accordingly, adding *len* bytes of
* space. It automatically extends and reallocates memory as
* required.
*
* This helper can be used on a layer 3 *skb* to push a MAC header
* for redirection into a layer 2 device.
*
* All values for *flags* are reserved for future usage, and must
* be left at zero.
*
* A call to this helper is susceptible to change the underlying
* packet buffer. Therefore, at load time, all checks on pointers
* previously done by the verifier are invalidated and must be
* performed again, if the helper is used in combination with
* direct packet access.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_skb_change_head)(struct __sk_buff *skb, __u32 len, __u64 flags) = (void *) 43;
/*
* bpf_xdp_adjust_head
*
* Adjust (move) *xdp_md*\ **->data** by *delta* bytes. Note that
* it is possible to use a negative value for *delta*. This helper
* can be used to prepare the packet for pushing or popping
* headers.
*
* A call to this helper is susceptible to change the underlying
* packet buffer. Therefore, at load time, all checks on pointers
* previously done by the verifier are invalidated and must be
* performed again, if the helper is used in combination with
* direct packet access.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_xdp_adjust_head)(struct xdp_md *xdp_md, int delta) = (void *) 44;
/*
* bpf_probe_read_str
*
* Copy a NUL terminated string from an unsafe kernel address
* *unsafe_ptr* to *dst*. See **bpf_probe_read_kernel_str**\ () for
* more details.
*
* Generally, use **bpf_probe_read_user_str**\ () or
* **bpf_probe_read_kernel_str**\ () instead.
*
* Returns
* On success, the strictly positive length of the string,
* including the trailing NUL character. On error, a negative
* value.
*/
static long (* const bpf_probe_read_str)(void *dst, __u32 size, const void *unsafe_ptr) = (void *) 45;
/*
* bpf_get_socket_cookie
*
* If the **struct sk_buff** pointed by *skb* has a known socket,
* retrieve the cookie (generated by the kernel) of this socket.
* If no cookie has been set yet, generate a new cookie. Once
* generated, the socket cookie remains stable for the life of the
* socket. This helper can be useful for monitoring per socket
* networking traffic statistics as it provides a global socket
* identifier that can be assumed unique.
*
* Returns
* A 8-byte long unique number on success, or 0 if the socket
* field is missing inside *skb*.
*/
static __u64 (* const bpf_get_socket_cookie)(void *ctx) = (void *) 46;
/*
* bpf_get_socket_uid
*
* Get the owner UID of the socked associated to *skb*.
*
* Returns
* The owner UID of the socket associated to *skb*. If the socket
* is **NULL**, or if it is not a full socket (i.e. if it is a
* time-wait or a request socket instead), **overflowuid** value
* is returned (note that **overflowuid** might also be the actual
* UID value for the socket).
*/
static __u32 (* const bpf_get_socket_uid)(struct __sk_buff *skb) = (void *) 47;
/*
* bpf_set_hash
*
* Set the full hash for *skb* (set the field *skb*\ **->hash**)
* to value *hash*.
*
* Returns
* 0
*/
static long (* const bpf_set_hash)(struct __sk_buff *skb, __u32 hash) = (void *) 48;
/*
* bpf_setsockopt
*
* Emulate a call to **setsockopt()** on the socket associated to
* *bpf_socket*, which must be a full socket. The *level* at
* which the option resides and the name *optname* of the option
* must be specified, see **setsockopt(2)** for more information.
* The option value of length *optlen* is pointed by *optval*.
*
* *bpf_socket* should be one of the following:
*
* * **struct bpf_sock_ops** for **BPF_PROG_TYPE_SOCK_OPS**.
* * **struct bpf_sock_addr** for **BPF_CGROUP_INET4_CONNECT**,
* **BPF_CGROUP_INET6_CONNECT** and **BPF_CGROUP_UNIX_CONNECT**.
*
* This helper actually implements a subset of **setsockopt()**.
* It supports the following *level*\ s:
*
* * **SOL_SOCKET**, which supports the following *optname*\ s:
* **SO_RCVBUF**, **SO_SNDBUF**, **SO_MAX_PACING_RATE**,
* **SO_PRIORITY**, **SO_RCVLOWAT**, **SO_MARK**,
* **SO_BINDTODEVICE**, **SO_KEEPALIVE**, **SO_REUSEADDR**,
* **SO_REUSEPORT**, **SO_BINDTOIFINDEX**, **SO_TXREHASH**.
* * **IPPROTO_TCP**, which supports the following *optname*\ s:
* **TCP_CONGESTION**, **TCP_BPF_IW**,
* **TCP_BPF_SNDCWND_CLAMP**, **TCP_SAVE_SYN**,
* **TCP_KEEPIDLE**, **TCP_KEEPINTVL**, **TCP_KEEPCNT**,
* **TCP_SYNCNT**, **TCP_USER_TIMEOUT**, **TCP_NOTSENT_LOWAT**,
* **TCP_NODELAY**, **TCP_MAXSEG**, **TCP_WINDOW_CLAMP**,
* **TCP_THIN_LINEAR_TIMEOUTS**, **TCP_BPF_DELACK_MAX**,
* **TCP_BPF_RTO_MIN**.
* * **IPPROTO_IP**, which supports *optname* **IP_TOS**.
* * **IPPROTO_IPV6**, which supports the following *optname*\ s:
* **IPV6_TCLASS**, **IPV6_AUTOFLOWLABEL**.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_setsockopt)(void *bpf_socket, int level, int optname, void *optval, int optlen) = (void *) 49;
/*
* bpf_skb_adjust_room
*
* Grow or shrink the room for data in the packet associated to
* *skb* by *len_diff*, and according to the selected *mode*.
*
* By default, the helper will reset any offloaded checksum
* indicator of the skb to CHECKSUM_NONE. This can be avoided
* by the following flag:
*
* * **BPF_F_ADJ_ROOM_NO_CSUM_RESET**: Do not reset offloaded
* checksum data of the skb to CHECKSUM_NONE.
*
* There are two supported modes at this time:
*
* * **BPF_ADJ_ROOM_MAC**: Adjust room at the mac layer
* (room space is added or removed between the layer 2 and
* layer 3 headers).
*
* * **BPF_ADJ_ROOM_NET**: Adjust room at the network layer
* (room space is added or removed between the layer 3 and
* layer 4 headers).
*
* The following flags are supported at this time:
*
* * **BPF_F_ADJ_ROOM_FIXED_GSO**: Do not adjust gso_size.
* Adjusting mss in this way is not allowed for datagrams.
*
* * **BPF_F_ADJ_ROOM_ENCAP_L3_IPV4**,
* **BPF_F_ADJ_ROOM_ENCAP_L3_IPV6**:
* Any new space is reserved to hold a tunnel header.
* Configure skb offsets and other fields accordingly.
*
* * **BPF_F_ADJ_ROOM_ENCAP_L4_GRE**,
* **BPF_F_ADJ_ROOM_ENCAP_L4_UDP**:
* Use with ENCAP_L3 flags to further specify the tunnel type.
*
* * **BPF_F_ADJ_ROOM_ENCAP_L2**\ (*len*):
* Use with ENCAP_L3/L4 flags to further specify the tunnel
* type; *len* is the length of the inner MAC header.
*
* * **BPF_F_ADJ_ROOM_ENCAP_L2_ETH**:
* Use with BPF_F_ADJ_ROOM_ENCAP_L2 flag to further specify the
* L2 type as Ethernet.
*
* * **BPF_F_ADJ_ROOM_DECAP_L3_IPV4**,
* **BPF_F_ADJ_ROOM_DECAP_L3_IPV6**:
* Indicate the new IP header version after decapsulating the outer
* IP header. Used when the inner and outer IP versions are different.
*
* A call to this helper is susceptible to change the underlying
* packet buffer. Therefore, at load time, all checks on pointers
* previously done by the verifier are invalidated and must be
* performed again, if the helper is used in combination with
* direct packet access.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_skb_adjust_room)(struct __sk_buff *skb, __s32 len_diff, __u32 mode, __u64 flags) = (void *) 50;
/*
* bpf_redirect_map
*
* Redirect the packet to the endpoint referenced by *map* at
* index *key*. Depending on its type, this *map* can contain
* references to net devices (for forwarding packets through other
* ports), or to CPUs (for redirecting XDP frames to another CPU;
* but this is only implemented for native XDP (with driver
* support) as of this writing).
*
* The lower two bits of *flags* are used as the return code if
* the map lookup fails. This is so that the return value can be
* one of the XDP program return codes up to **XDP_TX**, as chosen
* by the caller. The higher bits of *flags* can be set to
* BPF_F_BROADCAST or BPF_F_EXCLUDE_INGRESS as defined below.
*
* With BPF_F_BROADCAST the packet will be broadcasted to all the
* interfaces in the map, with BPF_F_EXCLUDE_INGRESS the ingress
* interface will be excluded when do broadcasting.
*
* See also **bpf_redirect**\ (), which only supports redirecting
* to an ifindex, but doesn't require a map to do so.
*
* Returns
* **XDP_REDIRECT** on success, or the value of the two lower bits
* of the *flags* argument on error.
*/
static long (* const bpf_redirect_map)(void *map, __u64 key, __u64 flags) = (void *) 51;
/*
* bpf_sk_redirect_map
*
* Redirect the packet to the socket referenced by *map* (of type
* **BPF_MAP_TYPE_SOCKMAP**) at index *key*. Both ingress and
* egress interfaces can be used for redirection. The
* **BPF_F_INGRESS** value in *flags* is used to make the
* distinction (ingress path is selected if the flag is present,
* egress path otherwise). This is the only flag supported for now.
*
* Returns
* **SK_PASS** on success, or **SK_DROP** on error.
*/
static long (* const bpf_sk_redirect_map)(struct __sk_buff *skb, void *map, __u32 key, __u64 flags) = (void *) 52;
/*
* bpf_sock_map_update
*
* Add an entry to, or update a *map* referencing sockets. The
* *skops* is used as a new value for the entry associated to
* *key*. *flags* is one of:
*
* **BPF_NOEXIST**
* The entry for *key* must not exist in the map.
* **BPF_EXIST**
* The entry for *key* must already exist in the map.
* **BPF_ANY**
* No condition on the existence of the entry for *key*.
*
* If the *map* has eBPF programs (parser and verdict), those will
* be inherited by the socket being added. If the socket is
* already attached to eBPF programs, this results in an error.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_sock_map_update)(struct bpf_sock_ops *skops, void *map, void *key, __u64 flags) = (void *) 53;
/*
* bpf_xdp_adjust_meta
*
* Adjust the address pointed by *xdp_md*\ **->data_meta** by
* *delta* (which can be positive or negative). Note that this
* operation modifies the address stored in *xdp_md*\ **->data**,
* so the latter must be loaded only after the helper has been
* called.
*
* The use of *xdp_md*\ **->data_meta** is optional and programs
* are not required to use it. The rationale is that when the
* packet is processed with XDP (e.g. as DoS filter), it is
* possible to push further meta data along with it before passing
* to the stack, and to give the guarantee that an ingress eBPF
* program attached as a TC classifier on the same device can pick
* this up for further post-processing. Since TC works with socket
* buffers, it remains possible to set from XDP the **mark** or
* **priority** pointers, or other pointers for the socket buffer.
* Having this scratch space generic and programmable allows for
* more flexibility as the user is free to store whatever meta
* data they need.
*
* A call to this helper is susceptible to change the underlying
* packet buffer. Therefore, at load time, all checks on pointers
* previously done by the verifier are invalidated and must be
* performed again, if the helper is used in combination with
* direct packet access.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_xdp_adjust_meta)(struct xdp_md *xdp_md, int delta) = (void *) 54;
/*
* bpf_perf_event_read_value
*
* Read the value of a perf event counter, and store it into *buf*
* of size *buf_size*. This helper relies on a *map* of type
* **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. The nature of the perf event
* counter is selected when *map* is updated with perf event file
* descriptors. The *map* is an array whose size is the number of
* available CPUs, and each cell contains a value relative to one
* CPU. The value to retrieve is indicated by *flags*, that
* contains the index of the CPU to look up, masked with
* **BPF_F_INDEX_MASK**. Alternatively, *flags* can be set to
* **BPF_F_CURRENT_CPU** to indicate that the value for the
* current CPU should be retrieved.
*
* This helper behaves in a way close to
* **bpf_perf_event_read**\ () helper, save that instead of
* just returning the value observed, it fills the *buf*
* structure. This allows for additional data to be retrieved: in
* particular, the enabled and running times (in *buf*\
* **->enabled** and *buf*\ **->running**, respectively) are
* copied. In general, **bpf_perf_event_read_value**\ () is
* recommended over **bpf_perf_event_read**\ (), which has some
* ABI issues and provides fewer functionalities.
*
* These values are interesting, because hardware PMU (Performance
* Monitoring Unit) counters are limited resources. When there are
* more PMU based perf events opened than available counters,
* kernel will multiplex these events so each event gets certain
* percentage (but not all) of the PMU time. In case that
* multiplexing happens, the number of samples or counter value
* will not reflect the case compared to when no multiplexing
* occurs. This makes comparison between different runs difficult.
* Typically, the counter value should be normalized before
* comparing to other experiments. The usual normalization is done
* as follows.
*
* ::
*
* normalized_counter = counter * t_enabled / t_running
*
* Where t_enabled is the time enabled for event and t_running is
* the time running for event since last normalization. The
* enabled and running times are accumulated since the perf event
* open. To achieve scaling factor between two invocations of an
* eBPF program, users can use CPU id as the key (which is
* typical for perf array usage model) to remember the previous
* value and do the calculation inside the eBPF program.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_perf_event_read_value)(void *map, __u64 flags, struct bpf_perf_event_value *buf, __u32 buf_size) = (void *) 55;
/*
* bpf_perf_prog_read_value
*
* For an eBPF program attached to a perf event, retrieve the
* value of the event counter associated to *ctx* and store it in
* the structure pointed by *buf* and of size *buf_size*. Enabled
* and running times are also stored in the structure (see
* description of helper **bpf_perf_event_read_value**\ () for
* more details).
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_perf_prog_read_value)(struct bpf_perf_event_data *ctx, struct bpf_perf_event_value *buf, __u32 buf_size) = (void *) 56;
/*
* bpf_getsockopt
*
* Emulate a call to **getsockopt()** on the socket associated to
* *bpf_socket*, which must be a full socket. The *level* at
* which the option resides and the name *optname* of the option
* must be specified, see **getsockopt(2)** for more information.
* The retrieved value is stored in the structure pointed by
* *opval* and of length *optlen*.
*
* *bpf_socket* should be one of the following:
*
* * **struct bpf_sock_ops** for **BPF_PROG_TYPE_SOCK_OPS**.
* * **struct bpf_sock_addr** for **BPF_CGROUP_INET4_CONNECT**,
* **BPF_CGROUP_INET6_CONNECT** and **BPF_CGROUP_UNIX_CONNECT**.
*
* This helper actually implements a subset of **getsockopt()**.
* It supports the same set of *optname*\ s that is supported by
* the **bpf_setsockopt**\ () helper. The exceptions are
* **TCP_BPF_*** is **bpf_setsockopt**\ () only and
* **TCP_SAVED_SYN** is **bpf_getsockopt**\ () only.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_getsockopt)(void *bpf_socket, int level, int optname, void *optval, int optlen) = (void *) 57;
/*
* bpf_override_return
*
* Used for error injection, this helper uses kprobes to override
* the return value of the probed function, and to set it to *rc*.
* The first argument is the context *regs* on which the kprobe
* works.
*
* This helper works by setting the PC (program counter)
* to an override function which is run in place of the original
* probed function. This means the probed function is not run at
* all. The replacement function just returns with the required
* value.
*
* This helper has security implications, and thus is subject to
* restrictions. It is only available if the kernel was compiled
* with the **CONFIG_BPF_KPROBE_OVERRIDE** configuration
* option, and in this case it only works on functions tagged with
* **ALLOW_ERROR_INJECTION** in the kernel code.
*
* Also, the helper is only available for the architectures having
* the CONFIG_FUNCTION_ERROR_INJECTION option. As of this writing,
* x86 architecture is the only one to support this feature.
*
* Returns
* 0
*/
static long (* const bpf_override_return)(struct pt_regs *regs, __u64 rc) = (void *) 58;
/*
* bpf_sock_ops_cb_flags_set
*
* Attempt to set the value of the **bpf_sock_ops_cb_flags** field
* for the full TCP socket associated to *bpf_sock_ops* to
* *argval*.
*
* The primary use of this field is to determine if there should
* be calls to eBPF programs of type
* **BPF_PROG_TYPE_SOCK_OPS** at various points in the TCP
* code. A program of the same type can change its value, per
* connection and as necessary, when the connection is
* established. This field is directly accessible for reading, but
* this helper must be used for updates in order to return an
* error if an eBPF program tries to set a callback that is not
* supported in the current kernel.
*
* *argval* is a flag array which can combine these flags:
*
* * **BPF_SOCK_OPS_RTO_CB_FLAG** (retransmission time out)
* * **BPF_SOCK_OPS_RETRANS_CB_FLAG** (retransmission)
* * **BPF_SOCK_OPS_STATE_CB_FLAG** (TCP state change)
* * **BPF_SOCK_OPS_RTT_CB_FLAG** (every RTT)
*
* Therefore, this function can be used to clear a callback flag by
* setting the appropriate bit to zero. e.g. to disable the RTO
* callback:
*
* **bpf_sock_ops_cb_flags_set(bpf_sock,**
* **bpf_sock->bpf_sock_ops_cb_flags & ~BPF_SOCK_OPS_RTO_CB_FLAG)**
*
* Here are some examples of where one could call such eBPF
* program:
*
* * When RTO fires.
* * When a packet is retransmitted.
* * When the connection terminates.
* * When a packet is sent.
* * When a packet is received.
*
* Returns
* Code **-EINVAL** if the socket is not a full TCP socket;
* otherwise, a positive number containing the bits that could not
* be set is returned (which comes down to 0 if all bits were set
* as required).
*/
static long (* const bpf_sock_ops_cb_flags_set)(struct bpf_sock_ops *bpf_sock, int argval) = (void *) 59;
/*
* bpf_msg_redirect_map
*
* This helper is used in programs implementing policies at the
* socket level. If the message *msg* is allowed to pass (i.e. if
* the verdict eBPF program returns **SK_PASS**), redirect it to
* the socket referenced by *map* (of type
* **BPF_MAP_TYPE_SOCKMAP**) at index *key*. Both ingress and
* egress interfaces can be used for redirection. The
* **BPF_F_INGRESS** value in *flags* is used to make the
* distinction (ingress path is selected if the flag is present,
* egress path otherwise). This is the only flag supported for now.
*
* Returns
* **SK_PASS** on success, or **SK_DROP** on error.
*/
static long (* const bpf_msg_redirect_map)(struct sk_msg_md *msg, void *map, __u32 key, __u64 flags) = (void *) 60;
/*
* bpf_msg_apply_bytes
*
* For socket policies, apply the verdict of the eBPF program to
* the next *bytes* (number of bytes) of message *msg*.
*
* For example, this helper can be used in the following cases:
*
* * A single **sendmsg**\ () or **sendfile**\ () system call
* contains multiple logical messages that the eBPF program is
* supposed to read and for which it should apply a verdict.
* * An eBPF program only cares to read the first *bytes* of a
* *msg*. If the message has a large payload, then setting up
* and calling the eBPF program repeatedly for all bytes, even
* though the verdict is already known, would create unnecessary
* overhead.
*
* When called from within an eBPF program, the helper sets a
* counter internal to the BPF infrastructure, that is used to
* apply the last verdict to the next *bytes*. If *bytes* is
* smaller than the current data being processed from a
* **sendmsg**\ () or **sendfile**\ () system call, the first
* *bytes* will be sent and the eBPF program will be re-run with
* the pointer for start of data pointing to byte number *bytes*
* **+ 1**. If *bytes* is larger than the current data being
* processed, then the eBPF verdict will be applied to multiple
* **sendmsg**\ () or **sendfile**\ () calls until *bytes* are
* consumed.
*
* Note that if a socket closes with the internal counter holding
* a non-zero value, this is not a problem because data is not
* being buffered for *bytes* and is sent as it is received.
*
* Returns
* 0
*/
static long (* const bpf_msg_apply_bytes)(struct sk_msg_md *msg, __u32 bytes) = (void *) 61;
/*
* bpf_msg_cork_bytes
*
* For socket policies, prevent the execution of the verdict eBPF
* program for message *msg* until *bytes* (byte number) have been
* accumulated.
*
* This can be used when one needs a specific number of bytes
* before a verdict can be assigned, even if the data spans
* multiple **sendmsg**\ () or **sendfile**\ () calls. The extreme
* case would be a user calling **sendmsg**\ () repeatedly with
* 1-byte long message segments. Obviously, this is bad for
* performance, but it is still valid. If the eBPF program needs
* *bytes* bytes to validate a header, this helper can be used to
* prevent the eBPF program to be called again until *bytes* have
* been accumulated.
*
* Returns
* 0
*/
static long (* const bpf_msg_cork_bytes)(struct sk_msg_md *msg, __u32 bytes) = (void *) 62;
/*
* bpf_msg_pull_data
*
* For socket policies, pull in non-linear data from user space
* for *msg* and set pointers *msg*\ **->data** and *msg*\
* **->data_end** to *start* and *end* bytes offsets into *msg*,
* respectively.
*
* If a program of type **BPF_PROG_TYPE_SK_MSG** is run on a
* *msg* it can only parse data that the (**data**, **data_end**)
* pointers have already consumed. For **sendmsg**\ () hooks this
* is likely the first scatterlist element. But for calls relying
* on the **sendpage** handler (e.g. **sendfile**\ ()) this will
* be the range (**0**, **0**) because the data is shared with
* user space and by default the objective is to avoid allowing
* user space to modify data while (or after) eBPF verdict is
* being decided. This helper can be used to pull in data and to
* set the start and end pointer to given values. Data will be
* copied if necessary (i.e. if data was not linear and if start
* and end pointers do not point to the same chunk).
*
* A call to this helper is susceptible to change the underlying
* packet buffer. Therefore, at load time, all checks on pointers
* previously done by the verifier are invalidated and must be
* performed again, if the helper is used in combination with
* direct packet access.
*
* All values for *flags* are reserved for future usage, and must
* be left at zero.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_msg_pull_data)(struct sk_msg_md *msg, __u32 start, __u32 end, __u64 flags) = (void *) 63;
/*
* bpf_bind
*
* Bind the socket associated to *ctx* to the address pointed by
* *addr*, of length *addr_len*. This allows for making outgoing
* connection from the desired IP address, which can be useful for
* example when all processes inside a cgroup should use one
* single IP address on a host that has multiple IP configured.
*
* This helper works for IPv4 and IPv6, TCP and UDP sockets. The
* domain (*addr*\ **->sa_family**) must be **AF_INET** (or
* **AF_INET6**). It's advised to pass zero port (**sin_port**
* or **sin6_port**) which triggers IP_BIND_ADDRESS_NO_PORT-like
* behavior and lets the kernel efficiently pick up an unused
* port as long as 4-tuple is unique. Passing non-zero port might
* lead to degraded performance.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_bind)(struct bpf_sock_addr *ctx, struct sockaddr *addr, int addr_len) = (void *) 64;
/*
* bpf_xdp_adjust_tail
*
* Adjust (move) *xdp_md*\ **->data_end** by *delta* bytes. It is
* possible to both shrink and grow the packet tail.
* Shrink done via *delta* being a negative integer.
*
* A call to this helper is susceptible to change the underlying
* packet buffer. Therefore, at load time, all checks on pointers
* previously done by the verifier are invalidated and must be
* performed again, if the helper is used in combination with
* direct packet access.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_xdp_adjust_tail)(struct xdp_md *xdp_md, int delta) = (void *) 65;
/*
* bpf_skb_get_xfrm_state
*
* Retrieve the XFRM state (IP transform framework, see also
* **ip-xfrm(8)**) at *index* in XFRM "security path" for *skb*.
*
* The retrieved value is stored in the **struct bpf_xfrm_state**
* pointed by *xfrm_state* and of length *size*.
*
* All values for *flags* are reserved for future usage, and must
* be left at zero.
*
* This helper is available only if the kernel was compiled with
* **CONFIG_XFRM** configuration option.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_skb_get_xfrm_state)(struct __sk_buff *skb, __u32 index, struct bpf_xfrm_state *xfrm_state, __u32 size, __u64 flags) = (void *) 66;
/*
* bpf_get_stack
*
* Return a user or a kernel stack in bpf program provided buffer.
* To achieve this, the helper needs *ctx*, which is a pointer
* to the context on which the tracing program is executed.
* To store the stacktrace, the bpf program provides *buf* with
* a nonnegative *size*.
*
* The last argument, *flags*, holds the number of stack frames to
* skip (from 0 to 255), masked with
* **BPF_F_SKIP_FIELD_MASK**. The next bits can be used to set
* the following flags:
*
* **BPF_F_USER_STACK**
* Collect a user space stack instead of a kernel stack.
* **BPF_F_USER_BUILD_ID**
* Collect (build_id, file_offset) instead of ips for user
* stack, only valid if **BPF_F_USER_STACK** is also
* specified.
*
* *file_offset* is an offset relative to the beginning
* of the executable or shared object file backing the vma
* which the *ip* falls in. It is *not* an offset relative
* to that object's base address. Accordingly, it must be
* adjusted by adding (sh_addr - sh_offset), where
* sh_{addr,offset} correspond to the executable section
* containing *file_offset* in the object, for comparisons
* to symbols' st_value to be valid.
*
* **bpf_get_stack**\ () can collect up to
* **PERF_MAX_STACK_DEPTH** both kernel and user frames, subject
* to sufficient large buffer size. Note that
* this limit can be controlled with the **sysctl** program, and
* that it should be manually increased in order to profile long
* user stacks (such as stacks for Java programs). To do so, use:
*
* ::
*
* # sysctl kernel.perf_event_max_stack=<new value>
*
* Returns
* The non-negative copied *buf* length equal to or less than
* *size* on success, or a negative error in case of failure.
*/
static long (* const bpf_get_stack)(void *ctx, void *buf, __u32 size, __u64 flags) = (void *) 67;
/*
* bpf_skb_load_bytes_relative
*
* This helper is similar to **bpf_skb_load_bytes**\ () in that
* it provides an easy way to load *len* bytes from *offset*
* from the packet associated to *skb*, into the buffer pointed
* by *to*. The difference to **bpf_skb_load_bytes**\ () is that
* a fifth argument *start_header* exists in order to select a
* base offset to start from. *start_header* can be one of:
*
* **BPF_HDR_START_MAC**
* Base offset to load data from is *skb*'s mac header.
* **BPF_HDR_START_NET**
* Base offset to load data from is *skb*'s network header.
*
* In general, "direct packet access" is the preferred method to
* access packet data, however, this helper is in particular useful
* in socket filters where *skb*\ **->data** does not always point
* to the start of the mac header and where "direct packet access"
* is not available.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_skb_load_bytes_relative)(const void *skb, __u32 offset, void *to, __u32 len, __u32 start_header) = (void *) 68;
/*
* bpf_fib_lookup
*
* Do FIB lookup in kernel tables using parameters in *params*.
* If lookup is successful and result shows packet is to be
* forwarded, the neighbor tables are searched for the nexthop.
* If successful (ie., FIB lookup shows forwarding and nexthop
* is resolved), the nexthop address is returned in ipv4_dst
* or ipv6_dst based on family, smac is set to mac address of
* egress device, dmac is set to nexthop mac address, rt_metric
* is set to metric from route (IPv4/IPv6 only), and ifindex
* is set to the device index of the nexthop from the FIB lookup.
*
* *plen* argument is the size of the passed in struct.
* *flags* argument can be a combination of one or more of the
* following values:
*
* **BPF_FIB_LOOKUP_DIRECT**
* Do a direct table lookup vs full lookup using FIB
* rules.
* **BPF_FIB_LOOKUP_TBID**
* Used with BPF_FIB_LOOKUP_DIRECT.
* Use the routing table ID present in *params*->tbid
* for the fib lookup.
* **BPF_FIB_LOOKUP_OUTPUT**
* Perform lookup from an egress perspective (default is
* ingress).
* **BPF_FIB_LOOKUP_SKIP_NEIGH**
* Skip the neighbour table lookup. *params*->dmac
* and *params*->smac will not be set as output. A common
* use case is to call **bpf_redirect_neigh**\ () after
* doing **bpf_fib_lookup**\ ().
* **BPF_FIB_LOOKUP_SRC**
* Derive and set source IP addr in *params*->ipv{4,6}_src
* for the nexthop. If the src addr cannot be derived,
* **BPF_FIB_LKUP_RET_NO_SRC_ADDR** is returned. In this
* case, *params*->dmac and *params*->smac are not set either.
*
* *ctx* is either **struct xdp_md** for XDP programs or
* **struct sk_buff** tc cls_act programs.
*
* Returns
* * < 0 if any input argument is invalid
* * 0 on success (packet is forwarded, nexthop neighbor exists)
* * > 0 one of **BPF_FIB_LKUP_RET_** codes explaining why the
* packet is not forwarded or needs assist from full stack
*
* If lookup fails with BPF_FIB_LKUP_RET_FRAG_NEEDED, then the MTU
* was exceeded and output params->mtu_result contains the MTU.
*/
static long (* const bpf_fib_lookup)(void *ctx, struct bpf_fib_lookup *params, int plen, __u32 flags) = (void *) 69;
/*
* bpf_sock_hash_update
*
* Add an entry to, or update a sockhash *map* referencing sockets.
* The *skops* is used as a new value for the entry associated to
* *key*. *flags* is one of:
*
* **BPF_NOEXIST**
* The entry for *key* must not exist in the map.
* **BPF_EXIST**
* The entry for *key* must already exist in the map.
* **BPF_ANY**
* No condition on the existence of the entry for *key*.
*
* If the *map* has eBPF programs (parser and verdict), those will
* be inherited by the socket being added. If the socket is
* already attached to eBPF programs, this results in an error.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_sock_hash_update)(struct bpf_sock_ops *skops, void *map, void *key, __u64 flags) = (void *) 70;
/*
* bpf_msg_redirect_hash
*
* This helper is used in programs implementing policies at the
* socket level. If the message *msg* is allowed to pass (i.e. if
* the verdict eBPF program returns **SK_PASS**), redirect it to
* the socket referenced by *map* (of type
* **BPF_MAP_TYPE_SOCKHASH**) using hash *key*. Both ingress and
* egress interfaces can be used for redirection. The
* **BPF_F_INGRESS** value in *flags* is used to make the
* distinction (ingress path is selected if the flag is present,
* egress path otherwise). This is the only flag supported for now.
*
* Returns
* **SK_PASS** on success, or **SK_DROP** on error.
*/
static long (* const bpf_msg_redirect_hash)(struct sk_msg_md *msg, void *map, void *key, __u64 flags) = (void *) 71;
/*
* bpf_sk_redirect_hash
*
* This helper is used in programs implementing policies at the
* skb socket level. If the sk_buff *skb* is allowed to pass (i.e.
* if the verdict eBPF program returns **SK_PASS**), redirect it
* to the socket referenced by *map* (of type
* **BPF_MAP_TYPE_SOCKHASH**) using hash *key*. Both ingress and
* egress interfaces can be used for redirection. The
* **BPF_F_INGRESS** value in *flags* is used to make the
* distinction (ingress path is selected if the flag is present,
* egress otherwise). This is the only flag supported for now.
*
* Returns
* **SK_PASS** on success, or **SK_DROP** on error.
*/
static long (* const bpf_sk_redirect_hash)(struct __sk_buff *skb, void *map, void *key, __u64 flags) = (void *) 72;
/*
* bpf_lwt_push_encap
*
* Encapsulate the packet associated to *skb* within a Layer 3
* protocol header. This header is provided in the buffer at
* address *hdr*, with *len* its size in bytes. *type* indicates
* the protocol of the header and can be one of:
*
* **BPF_LWT_ENCAP_SEG6**
* IPv6 encapsulation with Segment Routing Header
* (**struct ipv6_sr_hdr**). *hdr* only contains the SRH,
* the IPv6 header is computed by the kernel.
* **BPF_LWT_ENCAP_SEG6_INLINE**
* Only works if *skb* contains an IPv6 packet. Insert a
* Segment Routing Header (**struct ipv6_sr_hdr**) inside
* the IPv6 header.
* **BPF_LWT_ENCAP_IP**
* IP encapsulation (GRE/GUE/IPIP/etc). The outer header
* must be IPv4 or IPv6, followed by zero or more
* additional headers, up to **LWT_BPF_MAX_HEADROOM**
* total bytes in all prepended headers. Please note that
* if **skb_is_gso**\ (*skb*) is true, no more than two
* headers can be prepended, and the inner header, if
* present, should be either GRE or UDP/GUE.
*
* **BPF_LWT_ENCAP_SEG6**\ \* types can be called by BPF programs
* of type **BPF_PROG_TYPE_LWT_IN**; **BPF_LWT_ENCAP_IP** type can
* be called by bpf programs of types **BPF_PROG_TYPE_LWT_IN** and
* **BPF_PROG_TYPE_LWT_XMIT**.
*
* A call to this helper is susceptible to change the underlying
* packet buffer. Therefore, at load time, all checks on pointers
* previously done by the verifier are invalidated and must be
* performed again, if the helper is used in combination with
* direct packet access.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_lwt_push_encap)(struct __sk_buff *skb, __u32 type, void *hdr, __u32 len) = (void *) 73;
/*
* bpf_lwt_seg6_store_bytes
*
* Store *len* bytes from address *from* into the packet
* associated to *skb*, at *offset*. Only the flags, tag and TLVs
* inside the outermost IPv6 Segment Routing Header can be
* modified through this helper.
*
* A call to this helper is susceptible to change the underlying
* packet buffer. Therefore, at load time, all checks on pointers
* previously done by the verifier are invalidated and must be
* performed again, if the helper is used in combination with
* direct packet access.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_lwt_seg6_store_bytes)(struct __sk_buff *skb, __u32 offset, const void *from, __u32 len) = (void *) 74;
/*
* bpf_lwt_seg6_adjust_srh
*
* Adjust the size allocated to TLVs in the outermost IPv6
* Segment Routing Header contained in the packet associated to
* *skb*, at position *offset* by *delta* bytes. Only offsets
* after the segments are accepted. *delta* can be as well
* positive (growing) as negative (shrinking).
*
* A call to this helper is susceptible to change the underlying
* packet buffer. Therefore, at load time, all checks on pointers
* previously done by the verifier are invalidated and must be
* performed again, if the helper is used in combination with
* direct packet access.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_lwt_seg6_adjust_srh)(struct __sk_buff *skb, __u32 offset, __s32 delta) = (void *) 75;
/*
* bpf_lwt_seg6_action
*
* Apply an IPv6 Segment Routing action of type *action* to the
* packet associated to *skb*. Each action takes a parameter
* contained at address *param*, and of length *param_len* bytes.
* *action* can be one of:
*
* **SEG6_LOCAL_ACTION_END_X**
* End.X action: Endpoint with Layer-3 cross-connect.
* Type of *param*: **struct in6_addr**.
* **SEG6_LOCAL_ACTION_END_T**
* End.T action: Endpoint with specific IPv6 table lookup.
* Type of *param*: **int**.
* **SEG6_LOCAL_ACTION_END_B6**
* End.B6 action: Endpoint bound to an SRv6 policy.
* Type of *param*: **struct ipv6_sr_hdr**.
* **SEG6_LOCAL_ACTION_END_B6_ENCAP**
* End.B6.Encap action: Endpoint bound to an SRv6
* encapsulation policy.
* Type of *param*: **struct ipv6_sr_hdr**.
*
* A call to this helper is susceptible to change the underlying
* packet buffer. Therefore, at load time, all checks on pointers
* previously done by the verifier are invalidated and must be
* performed again, if the helper is used in combination with
* direct packet access.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_lwt_seg6_action)(struct __sk_buff *skb, __u32 action, void *param, __u32 param_len) = (void *) 76;
/*
* bpf_rc_repeat
*
* This helper is used in programs implementing IR decoding, to
* report a successfully decoded repeat key message. This delays
* the generation of a key up event for previously generated
* key down event.
*
* Some IR protocols like NEC have a special IR message for
* repeating last button, for when a button is held down.
*
* The *ctx* should point to the lirc sample as passed into
* the program.
*
* This helper is only available is the kernel was compiled with
* the **CONFIG_BPF_LIRC_MODE2** configuration option set to
* "**y**".
*
* Returns
* 0
*/
static long (* const bpf_rc_repeat)(void *ctx) = (void *) 77;
/*
* bpf_rc_keydown
*
* This helper is used in programs implementing IR decoding, to
* report a successfully decoded key press with *scancode*,
* *toggle* value in the given *protocol*. The scancode will be
* translated to a keycode using the rc keymap, and reported as
* an input key down event. After a period a key up event is
* generated. This period can be extended by calling either
* **bpf_rc_keydown**\ () again with the same values, or calling
* **bpf_rc_repeat**\ ().
*
* Some protocols include a toggle bit, in case the button was
* released and pressed again between consecutive scancodes.
*
* The *ctx* should point to the lirc sample as passed into
* the program.
*
* The *protocol* is the decoded protocol number (see
* **enum rc_proto** for some predefined values).
*
* This helper is only available is the kernel was compiled with
* the **CONFIG_BPF_LIRC_MODE2** configuration option set to
* "**y**".
*
* Returns
* 0
*/
static long (* const bpf_rc_keydown)(void *ctx, __u32 protocol, __u64 scancode, __u32 toggle) = (void *) 78;
/*
* bpf_skb_cgroup_id
*
* Return the cgroup v2 id of the socket associated with the *skb*.
* This is roughly similar to the **bpf_get_cgroup_classid**\ ()
* helper for cgroup v1 by providing a tag resp. identifier that
* can be matched on or used for map lookups e.g. to implement
* policy. The cgroup v2 id of a given path in the hierarchy is
* exposed in user space through the f_handle API in order to get
* to the same 64-bit id.
*
* This helper can be used on TC egress path, but not on ingress,
* and is available only if the kernel was compiled with the
* **CONFIG_SOCK_CGROUP_DATA** configuration option.
*
* Returns
* The id is returned or 0 in case the id could not be retrieved.
*/
static __u64 (* const bpf_skb_cgroup_id)(struct __sk_buff *skb) = (void *) 79;
/*
* bpf_get_current_cgroup_id
*
* Get the current cgroup id based on the cgroup within which
* the current task is running.
*
* Returns
* A 64-bit integer containing the current cgroup id based
* on the cgroup within which the current task is running.
*/
static __u64 (* const bpf_get_current_cgroup_id)(void) = (void *) 80;
/*
* bpf_get_local_storage
*
* Get the pointer to the local storage area.
* The type and the size of the local storage is defined
* by the *map* argument.
* The *flags* meaning is specific for each map type,
* and has to be 0 for cgroup local storage.
*
* Depending on the BPF program type, a local storage area
* can be shared between multiple instances of the BPF program,
* running simultaneously.
*
* A user should care about the synchronization by himself.
* For example, by using the **BPF_ATOMIC** instructions to alter
* the shared data.
*
* Returns
* A pointer to the local storage area.
*/
static void *(* const bpf_get_local_storage)(void *map, __u64 flags) = (void *) 81;
/*
* bpf_sk_select_reuseport
*
* Select a **SO_REUSEPORT** socket from a
* **BPF_MAP_TYPE_REUSEPORT_SOCKARRAY** *map*.
* It checks the selected socket is matching the incoming
* request in the socket buffer.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_sk_select_reuseport)(struct sk_reuseport_md *reuse, void *map, void *key, __u64 flags) = (void *) 82;
/*
* bpf_skb_ancestor_cgroup_id
*
* Return id of cgroup v2 that is ancestor of cgroup associated
* with the *skb* at the *ancestor_level*. The root cgroup is at
* *ancestor_level* zero and each step down the hierarchy
* increments the level. If *ancestor_level* == level of cgroup
* associated with *skb*, then return value will be same as that
* of **bpf_skb_cgroup_id**\ ().
*
* The helper is useful to implement policies based on cgroups
* that are upper in hierarchy than immediate cgroup associated
* with *skb*.
*
* The format of returned id and helper limitations are same as in
* **bpf_skb_cgroup_id**\ ().
*
* Returns
* The id is returned or 0 in case the id could not be retrieved.
*/
static __u64 (* const bpf_skb_ancestor_cgroup_id)(struct __sk_buff *skb, int ancestor_level) = (void *) 83;
/*
* bpf_sk_lookup_tcp
*
* Look for TCP socket matching *tuple*, optionally in a child
* network namespace *netns*. The return value must be checked,
* and if non-**NULL**, released via **bpf_sk_release**\ ().
*
* The *ctx* should point to the context of the program, such as
* the skb or socket (depending on the hook in use). This is used
* to determine the base network namespace for the lookup.
*
* *tuple_size* must be one of:
*
* **sizeof**\ (*tuple*\ **->ipv4**)
* Look for an IPv4 socket.
* **sizeof**\ (*tuple*\ **->ipv6**)
* Look for an IPv6 socket.
*
* If the *netns* is a negative signed 32-bit integer, then the
* socket lookup table in the netns associated with the *ctx*
* will be used. For the TC hooks, this is the netns of the device
* in the skb. For socket hooks, this is the netns of the socket.
* If *netns* is any other signed 32-bit value greater than or
* equal to zero then it specifies the ID of the netns relative to
* the netns associated with the *ctx*. *netns* values beyond the
* range of 32-bit integers are reserved for future use.
*
* All values for *flags* are reserved for future usage, and must
* be left at zero.
*
* This helper is available only if the kernel was compiled with
* **CONFIG_NET** configuration option.
*
* Returns
* Pointer to **struct bpf_sock**, or **NULL** in case of failure.
* For sockets with reuseport option, the **struct bpf_sock**
* result is from *reuse*\ **->socks**\ [] using the hash of the
* tuple.
*/
static struct bpf_sock *(* const bpf_sk_lookup_tcp)(void *ctx, struct bpf_sock_tuple *tuple, __u32 tuple_size, __u64 netns, __u64 flags) = (void *) 84;
/*
* bpf_sk_lookup_udp
*
* Look for UDP socket matching *tuple*, optionally in a child
* network namespace *netns*. The return value must be checked,
* and if non-**NULL**, released via **bpf_sk_release**\ ().
*
* The *ctx* should point to the context of the program, such as
* the skb or socket (depending on the hook in use). This is used
* to determine the base network namespace for the lookup.
*
* *tuple_size* must be one of:
*
* **sizeof**\ (*tuple*\ **->ipv4**)
* Look for an IPv4 socket.
* **sizeof**\ (*tuple*\ **->ipv6**)
* Look for an IPv6 socket.
*
* If the *netns* is a negative signed 32-bit integer, then the
* socket lookup table in the netns associated with the *ctx*
* will be used. For the TC hooks, this is the netns of the device
* in the skb. For socket hooks, this is the netns of the socket.
* If *netns* is any other signed 32-bit value greater than or
* equal to zero then it specifies the ID of the netns relative to
* the netns associated with the *ctx*. *netns* values beyond the
* range of 32-bit integers are reserved for future use.
*
* All values for *flags* are reserved for future usage, and must
* be left at zero.
*
* This helper is available only if the kernel was compiled with
* **CONFIG_NET** configuration option.
*
* Returns
* Pointer to **struct bpf_sock**, or **NULL** in case of failure.
* For sockets with reuseport option, the **struct bpf_sock**
* result is from *reuse*\ **->socks**\ [] using the hash of the
* tuple.
*/
static struct bpf_sock *(* const bpf_sk_lookup_udp)(void *ctx, struct bpf_sock_tuple *tuple, __u32 tuple_size, __u64 netns, __u64 flags) = (void *) 85;
/*
* bpf_sk_release
*
* Release the reference held by *sock*. *sock* must be a
* non-**NULL** pointer that was returned from
* **bpf_sk_lookup_xxx**\ ().
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_sk_release)(void *sock) = (void *) 86;
/*
* bpf_map_push_elem
*
* Push an element *value* in *map*. *flags* is one of:
*
* **BPF_EXIST**
* If the queue/stack is full, the oldest element is
* removed to make room for this.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_map_push_elem)(void *map, const void *value, __u64 flags) = (void *) 87;
/*
* bpf_map_pop_elem
*
* Pop an element from *map*.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_map_pop_elem)(void *map, void *value) = (void *) 88;
/*
* bpf_map_peek_elem
*
* Get an element from *map* without removing it.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_map_peek_elem)(void *map, void *value) = (void *) 89;
/*
* bpf_msg_push_data
*
* For socket policies, insert *len* bytes into *msg* at offset
* *start*.
*
* If a program of type **BPF_PROG_TYPE_SK_MSG** is run on a
* *msg* it may want to insert metadata or options into the *msg*.
* This can later be read and used by any of the lower layer BPF
* hooks.
*
* This helper may fail if under memory pressure (a malloc
* fails) in these cases BPF programs will get an appropriate
* error and BPF programs will need to handle them.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_msg_push_data)(struct sk_msg_md *msg, __u32 start, __u32 len, __u64 flags) = (void *) 90;
/*
* bpf_msg_pop_data
*
* Will remove *len* bytes from a *msg* starting at byte *start*.
* This may result in **ENOMEM** errors under certain situations if
* an allocation and copy are required due to a full ring buffer.
* However, the helper will try to avoid doing the allocation
* if possible. Other errors can occur if input parameters are
* invalid either due to *start* byte not being valid part of *msg*
* payload and/or *pop* value being to large.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_msg_pop_data)(struct sk_msg_md *msg, __u32 start, __u32 len, __u64 flags) = (void *) 91;
/*
* bpf_rc_pointer_rel
*
* This helper is used in programs implementing IR decoding, to
* report a successfully decoded pointer movement.
*
* The *ctx* should point to the lirc sample as passed into
* the program.
*
* This helper is only available is the kernel was compiled with
* the **CONFIG_BPF_LIRC_MODE2** configuration option set to
* "**y**".
*
* Returns
* 0
*/
static long (* const bpf_rc_pointer_rel)(void *ctx, __s32 rel_x, __s32 rel_y) = (void *) 92;
/*
* bpf_spin_lock
*
* Acquire a spinlock represented by the pointer *lock*, which is
* stored as part of a value of a map. Taking the lock allows to
* safely update the rest of the fields in that value. The
* spinlock can (and must) later be released with a call to
* **bpf_spin_unlock**\ (\ *lock*\ ).
*
* Spinlocks in BPF programs come with a number of restrictions
* and constraints:
*
* * **bpf_spin_lock** objects are only allowed inside maps of
* types **BPF_MAP_TYPE_HASH** and **BPF_MAP_TYPE_ARRAY** (this
* list could be extended in the future).
* * BTF description of the map is mandatory.
* * The BPF program can take ONE lock at a time, since taking two
* or more could cause dead locks.
* * Only one **struct bpf_spin_lock** is allowed per map element.
* * When the lock is taken, calls (either BPF to BPF or helpers)
* are not allowed.
* * The **BPF_LD_ABS** and **BPF_LD_IND** instructions are not
* allowed inside a spinlock-ed region.
* * The BPF program MUST call **bpf_spin_unlock**\ () to release
* the lock, on all execution paths, before it returns.
* * The BPF program can access **struct bpf_spin_lock** only via
* the **bpf_spin_lock**\ () and **bpf_spin_unlock**\ ()
* helpers. Loading or storing data into the **struct
* bpf_spin_lock** *lock*\ **;** field of a map is not allowed.
* * To use the **bpf_spin_lock**\ () helper, the BTF description
* of the map value must be a struct and have **struct
* bpf_spin_lock** *anyname*\ **;** field at the top level.
* Nested lock inside another struct is not allowed.
* * The **struct bpf_spin_lock** *lock* field in a map value must
* be aligned on a multiple of 4 bytes in that value.
* * Syscall with command **BPF_MAP_LOOKUP_ELEM** does not copy
* the **bpf_spin_lock** field to user space.
* * Syscall with command **BPF_MAP_UPDATE_ELEM**, or update from
* a BPF program, do not update the **bpf_spin_lock** field.
* * **bpf_spin_lock** cannot be on the stack or inside a
* networking packet (it can only be inside of a map values).
* * **bpf_spin_lock** is available to root only.
* * Tracing programs and socket filter programs cannot use
* **bpf_spin_lock**\ () due to insufficient preemption checks
* (but this may change in the future).
* * **bpf_spin_lock** is not allowed in inner maps of map-in-map.
*
* Returns
* 0
*/
static long (* const bpf_spin_lock)(struct bpf_spin_lock *lock) = (void *) 93;
/*
* bpf_spin_unlock
*
* Release the *lock* previously locked by a call to
* **bpf_spin_lock**\ (\ *lock*\ ).
*
* Returns
* 0
*/
static long (* const bpf_spin_unlock)(struct bpf_spin_lock *lock) = (void *) 94;
/*
* bpf_sk_fullsock
*
* This helper gets a **struct bpf_sock** pointer such
* that all the fields in this **bpf_sock** can be accessed.
*
* Returns
* A **struct bpf_sock** pointer on success, or **NULL** in
* case of failure.
*/
static struct bpf_sock *(* const bpf_sk_fullsock)(struct bpf_sock *sk) = (void *) 95;
/*
* bpf_tcp_sock
*
* This helper gets a **struct bpf_tcp_sock** pointer from a
* **struct bpf_sock** pointer.
*
* Returns
* A **struct bpf_tcp_sock** pointer on success, or **NULL** in
* case of failure.
*/
static struct bpf_tcp_sock *(* const bpf_tcp_sock)(struct bpf_sock *sk) = (void *) 96;
/*
* bpf_skb_ecn_set_ce
*
* Set ECN (Explicit Congestion Notification) field of IP header
* to **CE** (Congestion Encountered) if current value is **ECT**
* (ECN Capable Transport). Otherwise, do nothing. Works with IPv6
* and IPv4.
*
* Returns
* 1 if the **CE** flag is set (either by the current helper call
* or because it was already present), 0 if it is not set.
*/
static long (* const bpf_skb_ecn_set_ce)(struct __sk_buff *skb) = (void *) 97;
/*
* bpf_get_listener_sock
*
* Return a **struct bpf_sock** pointer in **TCP_LISTEN** state.
* **bpf_sk_release**\ () is unnecessary and not allowed.
*
* Returns
* A **struct bpf_sock** pointer on success, or **NULL** in
* case of failure.
*/
static struct bpf_sock *(* const bpf_get_listener_sock)(struct bpf_sock *sk) = (void *) 98;
/*
* bpf_skc_lookup_tcp
*
* Look for TCP socket matching *tuple*, optionally in a child
* network namespace *netns*. The return value must be checked,
* and if non-**NULL**, released via **bpf_sk_release**\ ().
*
* This function is identical to **bpf_sk_lookup_tcp**\ (), except
* that it also returns timewait or request sockets. Use
* **bpf_sk_fullsock**\ () or **bpf_tcp_sock**\ () to access the
* full structure.
*
* This helper is available only if the kernel was compiled with
* **CONFIG_NET** configuration option.
*
* Returns
* Pointer to **struct bpf_sock**, or **NULL** in case of failure.
* For sockets with reuseport option, the **struct bpf_sock**
* result is from *reuse*\ **->socks**\ [] using the hash of the
* tuple.
*/
static struct bpf_sock *(* const bpf_skc_lookup_tcp)(void *ctx, struct bpf_sock_tuple *tuple, __u32 tuple_size, __u64 netns, __u64 flags) = (void *) 99;
/*
* bpf_tcp_check_syncookie
*
* Check whether *iph* and *th* contain a valid SYN cookie ACK for
* the listening socket in *sk*.
*
* *iph* points to the start of the IPv4 or IPv6 header, while
* *iph_len* contains **sizeof**\ (**struct iphdr**) or
* **sizeof**\ (**struct ipv6hdr**).
*
* *th* points to the start of the TCP header, while *th_len*
* contains the length of the TCP header (at least
* **sizeof**\ (**struct tcphdr**)).
*
* Returns
* 0 if *iph* and *th* are a valid SYN cookie ACK, or a negative
* error otherwise.
*/
static long (* const bpf_tcp_check_syncookie)(void *sk, void *iph, __u32 iph_len, struct tcphdr *th, __u32 th_len) = (void *) 100;
/*
* bpf_sysctl_get_name
*
* Get name of sysctl in /proc/sys/ and copy it into provided by
* program buffer *buf* of size *buf_len*.
*
* The buffer is always NUL terminated, unless it's zero-sized.
*
* If *flags* is zero, full name (e.g. "net/ipv4/tcp_mem") is
* copied. Use **BPF_F_SYSCTL_BASE_NAME** flag to copy base name
* only (e.g. "tcp_mem").
*
* Returns
* Number of character copied (not including the trailing NUL).
*
* **-E2BIG** if the buffer wasn't big enough (*buf* will contain
* truncated name in this case).
*/
static long (* const bpf_sysctl_get_name)(struct bpf_sysctl *ctx, char *buf, unsigned long buf_len, __u64 flags) = (void *) 101;
/*
* bpf_sysctl_get_current_value
*
* Get current value of sysctl as it is presented in /proc/sys
* (incl. newline, etc), and copy it as a string into provided
* by program buffer *buf* of size *buf_len*.
*
* The whole value is copied, no matter what file position user
* space issued e.g. sys_read at.
*
* The buffer is always NUL terminated, unless it's zero-sized.
*
* Returns
* Number of character copied (not including the trailing NUL).
*
* **-E2BIG** if the buffer wasn't big enough (*buf* will contain
* truncated name in this case).
*
* **-EINVAL** if current value was unavailable, e.g. because
* sysctl is uninitialized and read returns -EIO for it.
*/
static long (* const bpf_sysctl_get_current_value)(struct bpf_sysctl *ctx, char *buf, unsigned long buf_len) = (void *) 102;
/*
* bpf_sysctl_get_new_value
*
* Get new value being written by user space to sysctl (before
* the actual write happens) and copy it as a string into
* provided by program buffer *buf* of size *buf_len*.
*
* User space may write new value at file position > 0.
*
* The buffer is always NUL terminated, unless it's zero-sized.
*
* Returns
* Number of character copied (not including the trailing NUL).
*
* **-E2BIG** if the buffer wasn't big enough (*buf* will contain
* truncated name in this case).
*
* **-EINVAL** if sysctl is being read.
*/
static long (* const bpf_sysctl_get_new_value)(struct bpf_sysctl *ctx, char *buf, unsigned long buf_len) = (void *) 103;
/*
* bpf_sysctl_set_new_value
*
* Override new value being written by user space to sysctl with
* value provided by program in buffer *buf* of size *buf_len*.
*
* *buf* should contain a string in same form as provided by user
* space on sysctl write.
*
* User space may write new value at file position > 0. To override
* the whole sysctl value file position should be set to zero.
*
* Returns
* 0 on success.
*
* **-E2BIG** if the *buf_len* is too big.
*
* **-EINVAL** if sysctl is being read.
*/
static long (* const bpf_sysctl_set_new_value)(struct bpf_sysctl *ctx, const char *buf, unsigned long buf_len) = (void *) 104;
/*
* bpf_strtol
*
* Convert the initial part of the string from buffer *buf* of
* size *buf_len* to a long integer according to the given base
* and save the result in *res*.
*
* The string may begin with an arbitrary amount of white space
* (as determined by **isspace**\ (3)) followed by a single
* optional '**-**' sign.
*
* Five least significant bits of *flags* encode base, other bits
* are currently unused.
*
* Base must be either 8, 10, 16 or 0 to detect it automatically
* similar to user space **strtol**\ (3).
*
* Returns
* Number of characters consumed on success. Must be positive but
* no more than *buf_len*.
*
* **-EINVAL** if no valid digits were found or unsupported base
* was provided.
*
* **-ERANGE** if resulting value was out of range.
*/
static long (* const bpf_strtol)(const char *buf, unsigned long buf_len, __u64 flags, long *res) = (void *) 105;
/*
* bpf_strtoul
*
* Convert the initial part of the string from buffer *buf* of
* size *buf_len* to an unsigned long integer according to the
* given base and save the result in *res*.
*
* The string may begin with an arbitrary amount of white space
* (as determined by **isspace**\ (3)).
*
* Five least significant bits of *flags* encode base, other bits
* are currently unused.
*
* Base must be either 8, 10, 16 or 0 to detect it automatically
* similar to user space **strtoul**\ (3).
*
* Returns
* Number of characters consumed on success. Must be positive but
* no more than *buf_len*.
*
* **-EINVAL** if no valid digits were found or unsupported base
* was provided.
*
* **-ERANGE** if resulting value was out of range.
*/
static long (* const bpf_strtoul)(const char *buf, unsigned long buf_len, __u64 flags, unsigned long *res) = (void *) 106;
/*
* bpf_sk_storage_get
*
* Get a bpf-local-storage from a *sk*.
*
* Logically, it could be thought of getting the value from
* a *map* with *sk* as the **key**. From this
* perspective, the usage is not much different from
* **bpf_map_lookup_elem**\ (*map*, **&**\ *sk*) except this
* helper enforces the key must be a full socket and the map must
* be a **BPF_MAP_TYPE_SK_STORAGE** also.
*
* Underneath, the value is stored locally at *sk* instead of
* the *map*. The *map* is used as the bpf-local-storage
* "type". The bpf-local-storage "type" (i.e. the *map*) is
* searched against all bpf-local-storages residing at *sk*.
*
* *sk* is a kernel **struct sock** pointer for LSM program.
* *sk* is a **struct bpf_sock** pointer for other program types.
*
* An optional *flags* (**BPF_SK_STORAGE_GET_F_CREATE**) can be
* used such that a new bpf-local-storage will be
* created if one does not exist. *value* can be used
* together with **BPF_SK_STORAGE_GET_F_CREATE** to specify
* the initial value of a bpf-local-storage. If *value* is
* **NULL**, the new bpf-local-storage will be zero initialized.
*
* Returns
* A bpf-local-storage pointer is returned on success.
*
* **NULL** if not found or there was an error in adding
* a new bpf-local-storage.
*/
static void *(* const bpf_sk_storage_get)(void *map, void *sk, void *value, __u64 flags) = (void *) 107;
/*
* bpf_sk_storage_delete
*
* Delete a bpf-local-storage from a *sk*.
*
* Returns
* 0 on success.
*
* **-ENOENT** if the bpf-local-storage cannot be found.
* **-EINVAL** if sk is not a fullsock (e.g. a request_sock).
*/
static long (* const bpf_sk_storage_delete)(void *map, void *sk) = (void *) 108;
/*
* bpf_send_signal
*
* Send signal *sig* to the process of the current task.
* The signal may be delivered to any of this process's threads.
*
* Returns
* 0 on success or successfully queued.
*
* **-EBUSY** if work queue under nmi is full.
*
* **-EINVAL** if *sig* is invalid.
*
* **-EPERM** if no permission to send the *sig*.
*
* **-EAGAIN** if bpf program can try again.
*/
static long (* const bpf_send_signal)(__u32 sig) = (void *) 109;
/*
* bpf_tcp_gen_syncookie
*
* Try to issue a SYN cookie for the packet with corresponding
* IP/TCP headers, *iph* and *th*, on the listening socket in *sk*.
*
* *iph* points to the start of the IPv4 or IPv6 header, while
* *iph_len* contains **sizeof**\ (**struct iphdr**) or
* **sizeof**\ (**struct ipv6hdr**).
*
* *th* points to the start of the TCP header, while *th_len*
* contains the length of the TCP header with options (at least
* **sizeof**\ (**struct tcphdr**)).
*
* Returns
* On success, lower 32 bits hold the generated SYN cookie in
* followed by 16 bits which hold the MSS value for that cookie,
* and the top 16 bits are unused.
*
* On failure, the returned value is one of the following:
*
* **-EINVAL** SYN cookie cannot be issued due to error
*
* **-ENOENT** SYN cookie should not be issued (no SYN flood)
*
* **-EOPNOTSUPP** kernel configuration does not enable SYN cookies
*
* **-EPROTONOSUPPORT** IP packet version is not 4 or 6
*/
static __s64 (* const bpf_tcp_gen_syncookie)(void *sk, void *iph, __u32 iph_len, struct tcphdr *th, __u32 th_len) = (void *) 110;
/*
* bpf_skb_output
*
* Write raw *data* blob into a special BPF perf event held by
* *map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. This perf
* event must have the following attributes: **PERF_SAMPLE_RAW**
* as **sample_type**, **PERF_TYPE_SOFTWARE** as **type**, and
* **PERF_COUNT_SW_BPF_OUTPUT** as **config**.
*
* The *flags* are used to indicate the index in *map* for which
* the value must be put, masked with **BPF_F_INDEX_MASK**.
* Alternatively, *flags* can be set to **BPF_F_CURRENT_CPU**
* to indicate that the index of the current CPU core should be
* used.
*
* The value to write, of *size*, is passed through eBPF stack and
* pointed by *data*.
*
* *ctx* is a pointer to in-kernel struct sk_buff.
*
* This helper is similar to **bpf_perf_event_output**\ () but
* restricted to raw_tracepoint bpf programs.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_skb_output)(void *ctx, void *map, __u64 flags, void *data, __u64 size) = (void *) 111;
/*
* bpf_probe_read_user
*
* Safely attempt to read *size* bytes from user space address
* *unsafe_ptr* and store the data in *dst*.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_probe_read_user)(void *dst, __u32 size, const void *unsafe_ptr) = (void *) 112;
/*
* bpf_probe_read_kernel
*
* Safely attempt to read *size* bytes from kernel space address
* *unsafe_ptr* and store the data in *dst*.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_probe_read_kernel)(void *dst, __u32 size, const void *unsafe_ptr) = (void *) 113;
/*
* bpf_probe_read_user_str
*
* Copy a NUL terminated string from an unsafe user address
* *unsafe_ptr* to *dst*. The *size* should include the
* terminating NUL byte. In case the string length is smaller than
* *size*, the target is not padded with further NUL bytes. If the
* string length is larger than *size*, just *size*-1 bytes are
* copied and the last byte is set to NUL.
*
* On success, returns the number of bytes that were written,
* including the terminal NUL. This makes this helper useful in
* tracing programs for reading strings, and more importantly to
* get its length at runtime. See the following snippet:
*
* ::
*
* SEC("kprobe/sys_open")
* void bpf_sys_open(struct pt_regs *ctx)
* {
* char buf[PATHLEN]; // PATHLEN is defined to 256
* int res = bpf_probe_read_user_str(buf, sizeof(buf),
* ctx->di);
*
* // Consume buf, for example push it to
* // userspace via bpf_perf_event_output(); we
* // can use res (the string length) as event
* // size, after checking its boundaries.
* }
*
* In comparison, using **bpf_probe_read_user**\ () helper here
* instead to read the string would require to estimate the length
* at compile time, and would often result in copying more memory
* than necessary.
*
* Another useful use case is when parsing individual process
* arguments or individual environment variables navigating
* *current*\ **->mm->arg_start** and *current*\
* **->mm->env_start**: using this helper and the return value,
* one can quickly iterate at the right offset of the memory area.
*
* Returns
* On success, the strictly positive length of the output string,
* including the trailing NUL character. On error, a negative
* value.
*/
static long (* const bpf_probe_read_user_str)(void *dst, __u32 size, const void *unsafe_ptr) = (void *) 114;
/*
* bpf_probe_read_kernel_str
*
* Copy a NUL terminated string from an unsafe kernel address *unsafe_ptr*
* to *dst*. Same semantics as with **bpf_probe_read_user_str**\ () apply.
*
* Returns
* On success, the strictly positive length of the string, including
* the trailing NUL character. On error, a negative value.
*/
static long (* const bpf_probe_read_kernel_str)(void *dst, __u32 size, const void *unsafe_ptr) = (void *) 115;
/*
* bpf_tcp_send_ack
*
* Send out a tcp-ack. *tp* is the in-kernel struct **tcp_sock**.
* *rcv_nxt* is the ack_seq to be sent out.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_tcp_send_ack)(void *tp, __u32 rcv_nxt) = (void *) 116;
/*
* bpf_send_signal_thread
*
* Send signal *sig* to the thread corresponding to the current task.
*
* Returns
* 0 on success or successfully queued.
*
* **-EBUSY** if work queue under nmi is full.
*
* **-EINVAL** if *sig* is invalid.
*
* **-EPERM** if no permission to send the *sig*.
*
* **-EAGAIN** if bpf program can try again.
*/
static long (* const bpf_send_signal_thread)(__u32 sig) = (void *) 117;
/*
* bpf_jiffies64
*
* Obtain the 64bit jiffies
*
* Returns
* The 64 bit jiffies
*/
static __u64 (* const bpf_jiffies64)(void) = (void *) 118;
/*
* bpf_read_branch_records
*
* For an eBPF program attached to a perf event, retrieve the
* branch records (**struct perf_branch_entry**) associated to *ctx*
* and store it in the buffer pointed by *buf* up to size
* *size* bytes.
*
* Returns
* On success, number of bytes written to *buf*. On error, a
* negative value.
*
* The *flags* can be set to **BPF_F_GET_BRANCH_RECORDS_SIZE** to
* instead return the number of bytes required to store all the
* branch entries. If this flag is set, *buf* may be NULL.
*
* **-EINVAL** if arguments invalid or **size** not a multiple
* of **sizeof**\ (**struct perf_branch_entry**\ ).
*
* **-ENOENT** if architecture does not support branch records.
*/
static long (* const bpf_read_branch_records)(struct bpf_perf_event_data *ctx, void *buf, __u32 size, __u64 flags) = (void *) 119;
/*
* bpf_get_ns_current_pid_tgid
*
* Returns 0 on success, values for *pid* and *tgid* as seen from the current
* *namespace* will be returned in *nsdata*.
*
* Returns
* 0 on success, or one of the following in case of failure:
*
* **-EINVAL** if dev and inum supplied don't match dev_t and inode number
* with nsfs of current task, or if dev conversion to dev_t lost high bits.
*
* **-ENOENT** if pidns does not exists for the current task.
*/
static long (* const bpf_get_ns_current_pid_tgid)(__u64 dev, __u64 ino, struct bpf_pidns_info *nsdata, __u32 size) = (void *) 120;
/*
* bpf_xdp_output
*
* Write raw *data* blob into a special BPF perf event held by
* *map* of type **BPF_MAP_TYPE_PERF_EVENT_ARRAY**. This perf
* event must have the following attributes: **PERF_SAMPLE_RAW**
* as **sample_type**, **PERF_TYPE_SOFTWARE** as **type**, and
* **PERF_COUNT_SW_BPF_OUTPUT** as **config**.
*
* The *flags* are used to indicate the index in *map* for which
* the value must be put, masked with **BPF_F_INDEX_MASK**.
* Alternatively, *flags* can be set to **BPF_F_CURRENT_CPU**
* to indicate that the index of the current CPU core should be
* used.
*
* The value to write, of *size*, is passed through eBPF stack and
* pointed by *data*.
*
* *ctx* is a pointer to in-kernel struct xdp_buff.
*
* This helper is similar to **bpf_perf_eventoutput**\ () but
* restricted to raw_tracepoint bpf programs.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_xdp_output)(void *ctx, void *map, __u64 flags, void *data, __u64 size) = (void *) 121;
/*
* bpf_get_netns_cookie
*
* Retrieve the cookie (generated by the kernel) of the network
* namespace the input *ctx* is associated with. The network
* namespace cookie remains stable for its lifetime and provides
* a global identifier that can be assumed unique. If *ctx* is
* NULL, then the helper returns the cookie for the initial
* network namespace. The cookie itself is very similar to that
* of **bpf_get_socket_cookie**\ () helper, but for network
* namespaces instead of sockets.
*
* Returns
* A 8-byte long opaque number.
*/
static __u64 (* const bpf_get_netns_cookie)(void *ctx) = (void *) 122;
/*
* bpf_get_current_ancestor_cgroup_id
*
* Return id of cgroup v2 that is ancestor of the cgroup associated
* with the current task at the *ancestor_level*. The root cgroup
* is at *ancestor_level* zero and each step down the hierarchy
* increments the level. If *ancestor_level* == level of cgroup
* associated with the current task, then return value will be the
* same as that of **bpf_get_current_cgroup_id**\ ().
*
* The helper is useful to implement policies based on cgroups
* that are upper in hierarchy than immediate cgroup associated
* with the current task.
*
* The format of returned id and helper limitations are same as in
* **bpf_get_current_cgroup_id**\ ().
*
* Returns
* The id is returned or 0 in case the id could not be retrieved.
*/
static __u64 (* const bpf_get_current_ancestor_cgroup_id)(int ancestor_level) = (void *) 123;
/*
* bpf_sk_assign
*
* Helper is overloaded depending on BPF program type. This
* description applies to **BPF_PROG_TYPE_SCHED_CLS** and
* **BPF_PROG_TYPE_SCHED_ACT** programs.
*
* Assign the *sk* to the *skb*. When combined with appropriate
* routing configuration to receive the packet towards the socket,
* will cause *skb* to be delivered to the specified socket.
* Subsequent redirection of *skb* via **bpf_redirect**\ (),
* **bpf_clone_redirect**\ () or other methods outside of BPF may
* interfere with successful delivery to the socket.
*
* This operation is only valid from TC ingress path.
*
* The *flags* argument must be zero.
*
* Returns
* 0 on success, or a negative error in case of failure:
*
* **-EINVAL** if specified *flags* are not supported.
*
* **-ENOENT** if the socket is unavailable for assignment.
*
* **-ENETUNREACH** if the socket is unreachable (wrong netns).
*
* **-EOPNOTSUPP** if the operation is not supported, for example
* a call from outside of TC ingress.
*/
static long (* const bpf_sk_assign)(void *ctx, void *sk, __u64 flags) = (void *) 124;
/*
* bpf_ktime_get_boot_ns
*
* Return the time elapsed since system boot, in nanoseconds.
* Does include the time the system was suspended.
* See: **clock_gettime**\ (**CLOCK_BOOTTIME**)
*
* Returns
* Current *ktime*.
*/
static __u64 (* const bpf_ktime_get_boot_ns)(void) = (void *) 125;
/*
* bpf_seq_printf
*
* **bpf_seq_printf**\ () uses seq_file **seq_printf**\ () to print
* out the format string.
* The *m* represents the seq_file. The *fmt* and *fmt_size* are for
* the format string itself. The *data* and *data_len* are format string
* arguments. The *data* are a **u64** array and corresponding format string
* values are stored in the array. For strings and pointers where pointees
* are accessed, only the pointer values are stored in the *data* array.
* The *data_len* is the size of *data* in bytes - must be a multiple of 8.
*
* Formats **%s**, **%p{i,I}{4,6}** requires to read kernel memory.
* Reading kernel memory may fail due to either invalid address or
* valid address but requiring a major memory fault. If reading kernel memory
* fails, the string for **%s** will be an empty string, and the ip
* address for **%p{i,I}{4,6}** will be 0. Not returning error to
* bpf program is consistent with what **bpf_trace_printk**\ () does for now.
*
* Returns
* 0 on success, or a negative error in case of failure:
*
* **-EBUSY** if per-CPU memory copy buffer is busy, can try again
* by returning 1 from bpf program.
*
* **-EINVAL** if arguments are invalid, or if *fmt* is invalid/unsupported.
*
* **-E2BIG** if *fmt* contains too many format specifiers.
*
* **-EOVERFLOW** if an overflow happened: The same object will be tried again.
*/
static long (* const bpf_seq_printf)(struct seq_file *m, const char *fmt, __u32 fmt_size, const void *data, __u32 data_len) = (void *) 126;
/*
* bpf_seq_write
*
* **bpf_seq_write**\ () uses seq_file **seq_write**\ () to write the data.
* The *m* represents the seq_file. The *data* and *len* represent the
* data to write in bytes.
*
* Returns
* 0 on success, or a negative error in case of failure:
*
* **-EOVERFLOW** if an overflow happened: The same object will be tried again.
*/
static long (* const bpf_seq_write)(struct seq_file *m, const void *data, __u32 len) = (void *) 127;
/*
* bpf_sk_cgroup_id
*
* Return the cgroup v2 id of the socket *sk*.
*
* *sk* must be a non-**NULL** pointer to a socket, e.g. one
* returned from **bpf_sk_lookup_xxx**\ (),
* **bpf_sk_fullsock**\ (), etc. The format of returned id is
* same as in **bpf_skb_cgroup_id**\ ().
*
* This helper is available only if the kernel was compiled with
* the **CONFIG_SOCK_CGROUP_DATA** configuration option.
*
* Returns
* The id is returned or 0 in case the id could not be retrieved.
*/
static __u64 (* const bpf_sk_cgroup_id)(void *sk) = (void *) 128;
/*
* bpf_sk_ancestor_cgroup_id
*
* Return id of cgroup v2 that is ancestor of cgroup associated
* with the *sk* at the *ancestor_level*. The root cgroup is at
* *ancestor_level* zero and each step down the hierarchy
* increments the level. If *ancestor_level* == level of cgroup
* associated with *sk*, then return value will be same as that
* of **bpf_sk_cgroup_id**\ ().
*
* The helper is useful to implement policies based on cgroups
* that are upper in hierarchy than immediate cgroup associated
* with *sk*.
*
* The format of returned id and helper limitations are same as in
* **bpf_sk_cgroup_id**\ ().
*
* Returns
* The id is returned or 0 in case the id could not be retrieved.
*/
static __u64 (* const bpf_sk_ancestor_cgroup_id)(void *sk, int ancestor_level) = (void *) 129;
/*
* bpf_ringbuf_output
*
* Copy *size* bytes from *data* into a ring buffer *ringbuf*.
* If **BPF_RB_NO_WAKEUP** is specified in *flags*, no notification
* of new data availability is sent.
* If **BPF_RB_FORCE_WAKEUP** is specified in *flags*, notification
* of new data availability is sent unconditionally.
* If **0** is specified in *flags*, an adaptive notification
* of new data availability is sent.
*
* An adaptive notification is a notification sent whenever the user-space
* process has caught up and consumed all available payloads. In case the user-space
* process is still processing a previous payload, then no notification is needed
* as it will process the newly added payload automatically.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_ringbuf_output)(void *ringbuf, void *data, __u64 size, __u64 flags) = (void *) 130;
/*
* bpf_ringbuf_reserve
*
* Reserve *size* bytes of payload in a ring buffer *ringbuf*.
* *flags* must be 0.
*
* Returns
* Valid pointer with *size* bytes of memory available; NULL,
* otherwise.
*/
static void *(* const bpf_ringbuf_reserve)(void *ringbuf, __u64 size, __u64 flags) = (void *) 131;
/*
* bpf_ringbuf_submit
*
* Submit reserved ring buffer sample, pointed to by *data*.
* If **BPF_RB_NO_WAKEUP** is specified in *flags*, no notification
* of new data availability is sent.
* If **BPF_RB_FORCE_WAKEUP** is specified in *flags*, notification
* of new data availability is sent unconditionally.
* If **0** is specified in *flags*, an adaptive notification
* of new data availability is sent.
*
* See 'bpf_ringbuf_output()' for the definition of adaptive notification.
*
* Returns
* Nothing. Always succeeds.
*/
static void (* const bpf_ringbuf_submit)(void *data, __u64 flags) = (void *) 132;
/*
* bpf_ringbuf_discard
*
* Discard reserved ring buffer sample, pointed to by *data*.
* If **BPF_RB_NO_WAKEUP** is specified in *flags*, no notification
* of new data availability is sent.
* If **BPF_RB_FORCE_WAKEUP** is specified in *flags*, notification
* of new data availability is sent unconditionally.
* If **0** is specified in *flags*, an adaptive notification
* of new data availability is sent.
*
* See 'bpf_ringbuf_output()' for the definition of adaptive notification.
*
* Returns
* Nothing. Always succeeds.
*/
static void (* const bpf_ringbuf_discard)(void *data, __u64 flags) = (void *) 133;
/*
* bpf_ringbuf_query
*
* Query various characteristics of provided ring buffer. What
* exactly is queries is determined by *flags*:
*
* * **BPF_RB_AVAIL_DATA**: Amount of data not yet consumed.
* * **BPF_RB_RING_SIZE**: The size of ring buffer.
* * **BPF_RB_CONS_POS**: Consumer position (can wrap around).
* * **BPF_RB_PROD_POS**: Producer(s) position (can wrap around).
*
* Data returned is just a momentary snapshot of actual values
* and could be inaccurate, so this facility should be used to
* power heuristics and for reporting, not to make 100% correct
* calculation.
*
* Returns
* Requested value, or 0, if *flags* are not recognized.
*/
static __u64 (* const bpf_ringbuf_query)(void *ringbuf, __u64 flags) = (void *) 134;
/*
* bpf_csum_level
*
* Change the skbs checksum level by one layer up or down, or
* reset it entirely to none in order to have the stack perform
* checksum validation. The level is applicable to the following
* protocols: TCP, UDP, GRE, SCTP, FCOE. For example, a decap of
* | ETH | IP | UDP | GUE | IP | TCP | into | ETH | IP | TCP |
* through **bpf_skb_adjust_room**\ () helper with passing in
* **BPF_F_ADJ_ROOM_NO_CSUM_RESET** flag would require one call
* to **bpf_csum_level**\ () with **BPF_CSUM_LEVEL_DEC** since
* the UDP header is removed. Similarly, an encap of the latter
* into the former could be accompanied by a helper call to
* **bpf_csum_level**\ () with **BPF_CSUM_LEVEL_INC** if the
* skb is still intended to be processed in higher layers of the
* stack instead of just egressing at tc.
*
* There are three supported level settings at this time:
*
* * **BPF_CSUM_LEVEL_INC**: Increases skb->csum_level for skbs
* with CHECKSUM_UNNECESSARY.
* * **BPF_CSUM_LEVEL_DEC**: Decreases skb->csum_level for skbs
* with CHECKSUM_UNNECESSARY.
* * **BPF_CSUM_LEVEL_RESET**: Resets skb->csum_level to 0 and
* sets CHECKSUM_NONE to force checksum validation by the stack.
* * **BPF_CSUM_LEVEL_QUERY**: No-op, returns the current
* skb->csum_level.
*
* Returns
* 0 on success, or a negative error in case of failure. In the
* case of **BPF_CSUM_LEVEL_QUERY**, the current skb->csum_level
* is returned or the error code -EACCES in case the skb is not
* subject to CHECKSUM_UNNECESSARY.
*/
static long (* const bpf_csum_level)(struct __sk_buff *skb, __u64 level) = (void *) 135;
/*
* bpf_skc_to_tcp6_sock
*
* Dynamically cast a *sk* pointer to a *tcp6_sock* pointer.
*
* Returns
* *sk* if casting is valid, or **NULL** otherwise.
*/
static struct tcp6_sock *(* const bpf_skc_to_tcp6_sock)(void *sk) = (void *) 136;
/*
* bpf_skc_to_tcp_sock
*
* Dynamically cast a *sk* pointer to a *tcp_sock* pointer.
*
* Returns
* *sk* if casting is valid, or **NULL** otherwise.
*/
static struct tcp_sock *(* const bpf_skc_to_tcp_sock)(void *sk) = (void *) 137;
/*
* bpf_skc_to_tcp_timewait_sock
*
* Dynamically cast a *sk* pointer to a *tcp_timewait_sock* pointer.
*
* Returns
* *sk* if casting is valid, or **NULL** otherwise.
*/
static struct tcp_timewait_sock *(* const bpf_skc_to_tcp_timewait_sock)(void *sk) = (void *) 138;
/*
* bpf_skc_to_tcp_request_sock
*
* Dynamically cast a *sk* pointer to a *tcp_request_sock* pointer.
*
* Returns
* *sk* if casting is valid, or **NULL** otherwise.
*/
static struct tcp_request_sock *(* const bpf_skc_to_tcp_request_sock)(void *sk) = (void *) 139;
/*
* bpf_skc_to_udp6_sock
*
* Dynamically cast a *sk* pointer to a *udp6_sock* pointer.
*
* Returns
* *sk* if casting is valid, or **NULL** otherwise.
*/
static struct udp6_sock *(* const bpf_skc_to_udp6_sock)(void *sk) = (void *) 140;
/*
* bpf_get_task_stack
*
* Return a user or a kernel stack in bpf program provided buffer.
* Note: the user stack will only be populated if the *task* is
* the current task; all other tasks will return -EOPNOTSUPP.
* To achieve this, the helper needs *task*, which is a valid
* pointer to **struct task_struct**. To store the stacktrace, the
* bpf program provides *buf* with a nonnegative *size*.
*
* The last argument, *flags*, holds the number of stack frames to
* skip (from 0 to 255), masked with
* **BPF_F_SKIP_FIELD_MASK**. The next bits can be used to set
* the following flags:
*
* **BPF_F_USER_STACK**
* Collect a user space stack instead of a kernel stack.
* The *task* must be the current task.
* **BPF_F_USER_BUILD_ID**
* Collect buildid+offset instead of ips for user stack,
* only valid if **BPF_F_USER_STACK** is also specified.
*
* **bpf_get_task_stack**\ () can collect up to
* **PERF_MAX_STACK_DEPTH** both kernel and user frames, subject
* to sufficient large buffer size. Note that
* this limit can be controlled with the **sysctl** program, and
* that it should be manually increased in order to profile long
* user stacks (such as stacks for Java programs). To do so, use:
*
* ::
*
* # sysctl kernel.perf_event_max_stack=<new value>
*
* Returns
* The non-negative copied *buf* length equal to or less than
* *size* on success, or a negative error in case of failure.
*/
static long (* const bpf_get_task_stack)(struct task_struct *task, void *buf, __u32 size, __u64 flags) = (void *) 141;
/*
* bpf_load_hdr_opt
*
* Load header option. Support reading a particular TCP header
* option for bpf program (**BPF_PROG_TYPE_SOCK_OPS**).
*
* If *flags* is 0, it will search the option from the
* *skops*\ **->skb_data**. The comment in **struct bpf_sock_ops**
* has details on what skb_data contains under different
* *skops*\ **->op**.
*
* The first byte of the *searchby_res* specifies the
* kind that it wants to search.
*
* If the searching kind is an experimental kind
* (i.e. 253 or 254 according to RFC6994). It also
* needs to specify the "magic" which is either
* 2 bytes or 4 bytes. It then also needs to
* specify the size of the magic by using
* the 2nd byte which is "kind-length" of a TCP
* header option and the "kind-length" also
* includes the first 2 bytes "kind" and "kind-length"
* itself as a normal TCP header option also does.
*
* For example, to search experimental kind 254 with
* 2 byte magic 0xeB9F, the searchby_res should be
* [ 254, 4, 0xeB, 0x9F, 0, 0, .... 0 ].
*
* To search for the standard window scale option (3),
* the *searchby_res* should be [ 3, 0, 0, .... 0 ].
* Note, kind-length must be 0 for regular option.
*
* Searching for No-Op (0) and End-of-Option-List (1) are
* not supported.
*
* *len* must be at least 2 bytes which is the minimal size
* of a header option.
*
* Supported flags:
*
* * **BPF_LOAD_HDR_OPT_TCP_SYN** to search from the
* saved_syn packet or the just-received syn packet.
*
*
* Returns
* > 0 when found, the header option is copied to *searchby_res*.
* The return value is the total length copied. On failure, a
* negative error code is returned:
*
* **-EINVAL** if a parameter is invalid.
*
* **-ENOMSG** if the option is not found.
*
* **-ENOENT** if no syn packet is available when
* **BPF_LOAD_HDR_OPT_TCP_SYN** is used.
*
* **-ENOSPC** if there is not enough space. Only *len* number of
* bytes are copied.
*
* **-EFAULT** on failure to parse the header options in the
* packet.
*
* **-EPERM** if the helper cannot be used under the current
* *skops*\ **->op**.
*/
static long (* const bpf_load_hdr_opt)(struct bpf_sock_ops *skops, void *searchby_res, __u32 len, __u64 flags) = (void *) 142;
/*
* bpf_store_hdr_opt
*
* Store header option. The data will be copied
* from buffer *from* with length *len* to the TCP header.
*
* The buffer *from* should have the whole option that
* includes the kind, kind-length, and the actual
* option data. The *len* must be at least kind-length
* long. The kind-length does not have to be 4 byte
* aligned. The kernel will take care of the padding
* and setting the 4 bytes aligned value to th->doff.
*
* This helper will check for duplicated option
* by searching the same option in the outgoing skb.
*
* This helper can only be called during
* **BPF_SOCK_OPS_WRITE_HDR_OPT_CB**.
*
*
* Returns
* 0 on success, or negative error in case of failure:
*
* **-EINVAL** If param is invalid.
*
* **-ENOSPC** if there is not enough space in the header.
* Nothing has been written
*
* **-EEXIST** if the option already exists.
*
* **-EFAULT** on failure to parse the existing header options.
*
* **-EPERM** if the helper cannot be used under the current
* *skops*\ **->op**.
*/
static long (* const bpf_store_hdr_opt)(struct bpf_sock_ops *skops, const void *from, __u32 len, __u64 flags) = (void *) 143;
/*
* bpf_reserve_hdr_opt
*
* Reserve *len* bytes for the bpf header option. The
* space will be used by **bpf_store_hdr_opt**\ () later in
* **BPF_SOCK_OPS_WRITE_HDR_OPT_CB**.
*
* If **bpf_reserve_hdr_opt**\ () is called multiple times,
* the total number of bytes will be reserved.
*
* This helper can only be called during
* **BPF_SOCK_OPS_HDR_OPT_LEN_CB**.
*
*
* Returns
* 0 on success, or negative error in case of failure:
*
* **-EINVAL** if a parameter is invalid.
*
* **-ENOSPC** if there is not enough space in the header.
*
* **-EPERM** if the helper cannot be used under the current
* *skops*\ **->op**.
*/
static long (* const bpf_reserve_hdr_opt)(struct bpf_sock_ops *skops, __u32 len, __u64 flags) = (void *) 144;
/*
* bpf_inode_storage_get
*
* Get a bpf_local_storage from an *inode*.
*
* Logically, it could be thought of as getting the value from
* a *map* with *inode* as the **key**. From this
* perspective, the usage is not much different from
* **bpf_map_lookup_elem**\ (*map*, **&**\ *inode*) except this
* helper enforces the key must be an inode and the map must also
* be a **BPF_MAP_TYPE_INODE_STORAGE**.
*
* Underneath, the value is stored locally at *inode* instead of
* the *map*. The *map* is used as the bpf-local-storage
* "type". The bpf-local-storage "type" (i.e. the *map*) is
* searched against all bpf_local_storage residing at *inode*.
*
* An optional *flags* (**BPF_LOCAL_STORAGE_GET_F_CREATE**) can be
* used such that a new bpf_local_storage will be
* created if one does not exist. *value* can be used
* together with **BPF_LOCAL_STORAGE_GET_F_CREATE** to specify
* the initial value of a bpf_local_storage. If *value* is
* **NULL**, the new bpf_local_storage will be zero initialized.
*
* Returns
* A bpf_local_storage pointer is returned on success.
*
* **NULL** if not found or there was an error in adding
* a new bpf_local_storage.
*/
static void *(* const bpf_inode_storage_get)(void *map, void *inode, void *value, __u64 flags) = (void *) 145;
/*
* bpf_inode_storage_delete
*
* Delete a bpf_local_storage from an *inode*.
*
* Returns
* 0 on success.
*
* **-ENOENT** if the bpf_local_storage cannot be found.
*/
static int (* const bpf_inode_storage_delete)(void *map, void *inode) = (void *) 146;
/*
* bpf_d_path
*
* Return full path for given **struct path** object, which
* needs to be the kernel BTF *path* object. The path is
* returned in the provided buffer *buf* of size *sz* and
* is zero terminated.
*
*
* Returns
* On success, the strictly positive length of the string,
* including the trailing NUL character. On error, a negative
* value.
*/
static long (* const bpf_d_path)(struct path *path, char *buf, __u32 sz) = (void *) 147;
/*
* bpf_copy_from_user
*
* Read *size* bytes from user space address *user_ptr* and store
* the data in *dst*. This is a wrapper of **copy_from_user**\ ().
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_copy_from_user)(void *dst, __u32 size, const void *user_ptr) = (void *) 148;
/*
* bpf_snprintf_btf
*
* Use BTF to store a string representation of *ptr*->ptr in *str*,
* using *ptr*->type_id. This value should specify the type
* that *ptr*->ptr points to. LLVM __builtin_btf_type_id(type, 1)
* can be used to look up vmlinux BTF type ids. Traversing the
* data structure using BTF, the type information and values are
* stored in the first *str_size* - 1 bytes of *str*. Safe copy of
* the pointer data is carried out to avoid kernel crashes during
* operation. Smaller types can use string space on the stack;
* larger programs can use map data to store the string
* representation.
*
* The string can be subsequently shared with userspace via
* bpf_perf_event_output() or ring buffer interfaces.
* bpf_trace_printk() is to be avoided as it places too small
* a limit on string size to be useful.
*
* *flags* is a combination of
*
* **BTF_F_COMPACT**
* no formatting around type information
* **BTF_F_NONAME**
* no struct/union member names/types
* **BTF_F_PTR_RAW**
* show raw (unobfuscated) pointer values;
* equivalent to printk specifier %px.
* **BTF_F_ZERO**
* show zero-valued struct/union members; they
* are not displayed by default
*
*
* Returns
* The number of bytes that were written (or would have been
* written if output had to be truncated due to string size),
* or a negative error in cases of failure.
*/
static long (* const bpf_snprintf_btf)(char *str, __u32 str_size, struct btf_ptr *ptr, __u32 btf_ptr_size, __u64 flags) = (void *) 149;
/*
* bpf_seq_printf_btf
*
* Use BTF to write to seq_write a string representation of
* *ptr*->ptr, using *ptr*->type_id as per bpf_snprintf_btf().
* *flags* are identical to those used for bpf_snprintf_btf.
*
* Returns
* 0 on success or a negative error in case of failure.
*/
static long (* const bpf_seq_printf_btf)(struct seq_file *m, struct btf_ptr *ptr, __u32 ptr_size, __u64 flags) = (void *) 150;
/*
* bpf_skb_cgroup_classid
*
* See **bpf_get_cgroup_classid**\ () for the main description.
* This helper differs from **bpf_get_cgroup_classid**\ () in that
* the cgroup v1 net_cls class is retrieved only from the *skb*'s
* associated socket instead of the current process.
*
* Returns
* The id is returned or 0 in case the id could not be retrieved.
*/
static __u64 (* const bpf_skb_cgroup_classid)(struct __sk_buff *skb) = (void *) 151;
/*
* bpf_redirect_neigh
*
* Redirect the packet to another net device of index *ifindex*
* and fill in L2 addresses from neighboring subsystem. This helper
* is somewhat similar to **bpf_redirect**\ (), except that it
* populates L2 addresses as well, meaning, internally, the helper
* relies on the neighbor lookup for the L2 address of the nexthop.
*
* The helper will perform a FIB lookup based on the skb's
* networking header to get the address of the next hop, unless
* this is supplied by the caller in the *params* argument. The
* *plen* argument indicates the len of *params* and should be set
* to 0 if *params* is NULL.
*
* The *flags* argument is reserved and must be 0. The helper is
* currently only supported for tc BPF program types, and enabled
* for IPv4 and IPv6 protocols.
*
* Returns
* The helper returns **TC_ACT_REDIRECT** on success or
* **TC_ACT_SHOT** on error.
*/
static long (* const bpf_redirect_neigh)(__u32 ifindex, struct bpf_redir_neigh *params, int plen, __u64 flags) = (void *) 152;
/*
* bpf_per_cpu_ptr
*
* Take a pointer to a percpu ksym, *percpu_ptr*, and return a
* pointer to the percpu kernel variable on *cpu*. A ksym is an
* extern variable decorated with '__ksym'. For ksym, there is a
* global var (either static or global) defined of the same name
* in the kernel. The ksym is percpu if the global var is percpu.
* The returned pointer points to the global percpu var on *cpu*.
*
* bpf_per_cpu_ptr() has the same semantic as per_cpu_ptr() in the
* kernel, except that bpf_per_cpu_ptr() may return NULL. This
* happens if *cpu* is larger than nr_cpu_ids. The caller of
* bpf_per_cpu_ptr() must check the returned value.
*
* Returns
* A pointer pointing to the kernel percpu variable on *cpu*, or
* NULL, if *cpu* is invalid.
*/
static void *(* const bpf_per_cpu_ptr)(const void *percpu_ptr, __u32 cpu) = (void *) 153;
/*
* bpf_this_cpu_ptr
*
* Take a pointer to a percpu ksym, *percpu_ptr*, and return a
* pointer to the percpu kernel variable on this cpu. See the
* description of 'ksym' in **bpf_per_cpu_ptr**\ ().
*
* bpf_this_cpu_ptr() has the same semantic as this_cpu_ptr() in
* the kernel. Different from **bpf_per_cpu_ptr**\ (), it would
* never return NULL.
*
* Returns
* A pointer pointing to the kernel percpu variable on this cpu.
*/
static void *(* const bpf_this_cpu_ptr)(const void *percpu_ptr) = (void *) 154;
/*
* bpf_redirect_peer
*
* Redirect the packet to another net device of index *ifindex*.
* This helper is somewhat similar to **bpf_redirect**\ (), except
* that the redirection happens to the *ifindex*' peer device and
* the netns switch takes place from ingress to ingress without
* going through the CPU's backlog queue.
*
* The *flags* argument is reserved and must be 0. The helper is
* currently only supported for tc BPF program types at the
* ingress hook and for veth and netkit target device types. The
* peer device must reside in a different network namespace.
*
* Returns
* The helper returns **TC_ACT_REDIRECT** on success or
* **TC_ACT_SHOT** on error.
*/
static long (* const bpf_redirect_peer)(__u32 ifindex, __u64 flags) = (void *) 155;
/*
* bpf_task_storage_get
*
* Get a bpf_local_storage from the *task*.
*
* Logically, it could be thought of as getting the value from
* a *map* with *task* as the **key**. From this
* perspective, the usage is not much different from
* **bpf_map_lookup_elem**\ (*map*, **&**\ *task*) except this
* helper enforces the key must be a task_struct and the map must also
* be a **BPF_MAP_TYPE_TASK_STORAGE**.
*
* Underneath, the value is stored locally at *task* instead of
* the *map*. The *map* is used as the bpf-local-storage
* "type". The bpf-local-storage "type" (i.e. the *map*) is
* searched against all bpf_local_storage residing at *task*.
*
* An optional *flags* (**BPF_LOCAL_STORAGE_GET_F_CREATE**) can be
* used such that a new bpf_local_storage will be
* created if one does not exist. *value* can be used
* together with **BPF_LOCAL_STORAGE_GET_F_CREATE** to specify
* the initial value of a bpf_local_storage. If *value* is
* **NULL**, the new bpf_local_storage will be zero initialized.
*
* Returns
* A bpf_local_storage pointer is returned on success.
*
* **NULL** if not found or there was an error in adding
* a new bpf_local_storage.
*/
static void *(* const bpf_task_storage_get)(void *map, struct task_struct *task, void *value, __u64 flags) = (void *) 156;
/*
* bpf_task_storage_delete
*
* Delete a bpf_local_storage from a *task*.
*
* Returns
* 0 on success.
*
* **-ENOENT** if the bpf_local_storage cannot be found.
*/
static long (* const bpf_task_storage_delete)(void *map, struct task_struct *task) = (void *) 157;
/*
* bpf_get_current_task_btf
*
* Return a BTF pointer to the "current" task.
* This pointer can also be used in helpers that accept an
* *ARG_PTR_TO_BTF_ID* of type *task_struct*.
*
* Returns
* Pointer to the current task.
*/
static struct task_struct *(* const bpf_get_current_task_btf)(void) = (void *) 158;
/*
* bpf_bprm_opts_set
*
* Set or clear certain options on *bprm*:
*
* **BPF_F_BPRM_SECUREEXEC** Set the secureexec bit
* which sets the **AT_SECURE** auxv for glibc. The bit
* is cleared if the flag is not specified.
*
* Returns
* **-EINVAL** if invalid *flags* are passed, zero otherwise.
*/
static long (* const bpf_bprm_opts_set)(struct linux_binprm *bprm, __u64 flags) = (void *) 159;
/*
* bpf_ktime_get_coarse_ns
*
* Return a coarse-grained version of the time elapsed since
* system boot, in nanoseconds. Does not include time the system
* was suspended.
*
* See: **clock_gettime**\ (**CLOCK_MONOTONIC_COARSE**)
*
* Returns
* Current *ktime*.
*/
static __u64 (* const bpf_ktime_get_coarse_ns)(void) = (void *) 160;
/*
* bpf_ima_inode_hash
*
* Returns the stored IMA hash of the *inode* (if it's available).
* If the hash is larger than *size*, then only *size*
* bytes will be copied to *dst*
*
* Returns
* The **hash_algo** is returned on success,
* **-EOPNOTSUP** if IMA is disabled or **-EINVAL** if
* invalid arguments are passed.
*/
static long (* const bpf_ima_inode_hash)(struct inode *inode, void *dst, __u32 size) = (void *) 161;
/*
* bpf_sock_from_file
*
* If the given file represents a socket, returns the associated
* socket.
*
* Returns
* A pointer to a struct socket on success or NULL if the file is
* not a socket.
*/
static struct socket *(* const bpf_sock_from_file)(struct file *file) = (void *) 162;
/*
* bpf_check_mtu
*
* Check packet size against exceeding MTU of net device (based
* on *ifindex*). This helper will likely be used in combination
* with helpers that adjust/change the packet size.
*
* The argument *len_diff* can be used for querying with a planned
* size change. This allows to check MTU prior to changing packet
* ctx. Providing a *len_diff* adjustment that is larger than the
* actual packet size (resulting in negative packet size) will in
* principle not exceed the MTU, which is why it is not considered
* a failure. Other BPF helpers are needed for performing the
* planned size change; therefore the responsibility for catching
* a negative packet size belongs in those helpers.
*
* Specifying *ifindex* zero means the MTU check is performed
* against the current net device. This is practical if this isn't
* used prior to redirect.
*
* On input *mtu_len* must be a valid pointer, else verifier will
* reject BPF program. If the value *mtu_len* is initialized to
* zero then the ctx packet size is use. When value *mtu_len* is
* provided as input this specify the L3 length that the MTU check
* is done against. Remember XDP and TC length operate at L2, but
* this value is L3 as this correlate to MTU and IP-header tot_len
* values which are L3 (similar behavior as bpf_fib_lookup).
*
* The Linux kernel route table can configure MTUs on a more
* specific per route level, which is not provided by this helper.
* For route level MTU checks use the **bpf_fib_lookup**\ ()
* helper.
*
* *ctx* is either **struct xdp_md** for XDP programs or
* **struct sk_buff** for tc cls_act programs.
*
* The *flags* argument can be a combination of one or more of the
* following values:
*
* **BPF_MTU_CHK_SEGS**
* This flag will only works for *ctx* **struct sk_buff**.
* If packet context contains extra packet segment buffers
* (often knows as GSO skb), then MTU check is harder to
* check at this point, because in transmit path it is
* possible for the skb packet to get re-segmented
* (depending on net device features). This could still be
* a MTU violation, so this flag enables performing MTU
* check against segments, with a different violation
* return code to tell it apart. Check cannot use len_diff.
*
* On return *mtu_len* pointer contains the MTU value of the net
* device. Remember the net device configured MTU is the L3 size,
* which is returned here and XDP and TC length operate at L2.
* Helper take this into account for you, but remember when using
* MTU value in your BPF-code.
*
*
* Returns
* * 0 on success, and populate MTU value in *mtu_len* pointer.
*
* * < 0 if any input argument is invalid (*mtu_len* not updated)
*
* MTU violations return positive values, but also populate MTU
* value in *mtu_len* pointer, as this can be needed for
* implementing PMTU handing:
*
* * **BPF_MTU_CHK_RET_FRAG_NEEDED**
* * **BPF_MTU_CHK_RET_SEGS_TOOBIG**
*/
static long (* const bpf_check_mtu)(void *ctx, __u32 ifindex, __u32 *mtu_len, __s32 len_diff, __u64 flags) = (void *) 163;
/*
* bpf_for_each_map_elem
*
* For each element in **map**, call **callback_fn** function with
* **map**, **callback_ctx** and other map-specific parameters.
* The **callback_fn** should be a static function and
* the **callback_ctx** should be a pointer to the stack.
* The **flags** is used to control certain aspects of the helper.
* Currently, the **flags** must be 0.
*
* The following are a list of supported map types and their
* respective expected callback signatures:
*
* BPF_MAP_TYPE_HASH, BPF_MAP_TYPE_PERCPU_HASH,
* BPF_MAP_TYPE_LRU_HASH, BPF_MAP_TYPE_LRU_PERCPU_HASH,
* BPF_MAP_TYPE_ARRAY, BPF_MAP_TYPE_PERCPU_ARRAY
*
* long (\*callback_fn)(struct bpf_map \*map, const void \*key, void \*value, void \*ctx);
*
* For per_cpu maps, the map_value is the value on the cpu where the
* bpf_prog is running.
*
* If **callback_fn** return 0, the helper will continue to the next
* element. If return value is 1, the helper will skip the rest of
* elements and return. Other return values are not used now.
*
*
* Returns
* The number of traversed map elements for success, **-EINVAL** for
* invalid **flags**.
*/
static long (* const bpf_for_each_map_elem)(void *map, void *callback_fn, void *callback_ctx, __u64 flags) = (void *) 164;
/*
* bpf_snprintf
*
* Outputs a string into the **str** buffer of size **str_size**
* based on a format string stored in a read-only map pointed by
* **fmt**.
*
* Each format specifier in **fmt** corresponds to one u64 element
* in the **data** array. For strings and pointers where pointees
* are accessed, only the pointer values are stored in the *data*
* array. The *data_len* is the size of *data* in bytes - must be
* a multiple of 8.
*
* Formats **%s** and **%p{i,I}{4,6}** require to read kernel
* memory. Reading kernel memory may fail due to either invalid
* address or valid address but requiring a major memory fault. If
* reading kernel memory fails, the string for **%s** will be an
* empty string, and the ip address for **%p{i,I}{4,6}** will be 0.
* Not returning error to bpf program is consistent with what
* **bpf_trace_printk**\ () does for now.
*
*
* Returns
* The strictly positive length of the formatted string, including
* the trailing zero character. If the return value is greater than
* **str_size**, **str** contains a truncated string, guaranteed to
* be zero-terminated except when **str_size** is 0.
*
* Or **-EBUSY** if the per-CPU memory copy buffer is busy.
*/
static long (* const bpf_snprintf)(char *str, __u32 str_size, const char *fmt, __u64 *data, __u32 data_len) = (void *) 165;
/*
* bpf_sys_bpf
*
* Execute bpf syscall with given arguments.
*
* Returns
* A syscall result.
*/
static long (* const bpf_sys_bpf)(__u32 cmd, void *attr, __u32 attr_size) = (void *) 166;
/*
* bpf_btf_find_by_name_kind
*
* Find BTF type with given name and kind in vmlinux BTF or in module's BTFs.
*
* Returns
* Returns btf_id and btf_obj_fd in lower and upper 32 bits.
*/
static long (* const bpf_btf_find_by_name_kind)(char *name, int name_sz, __u32 kind, int flags) = (void *) 167;
/*
* bpf_sys_close
*
* Execute close syscall for given FD.
*
* Returns
* A syscall result.
*/
static long (* const bpf_sys_close)(__u32 fd) = (void *) 168;
/*
* bpf_timer_init
*
* Initialize the timer.
* First 4 bits of *flags* specify clockid.
* Only CLOCK_MONOTONIC, CLOCK_REALTIME, CLOCK_BOOTTIME are allowed.
* All other bits of *flags* are reserved.
* The verifier will reject the program if *timer* is not from
* the same *map*.
*
* Returns
* 0 on success.
* **-EBUSY** if *timer* is already initialized.
* **-EINVAL** if invalid *flags* are passed.
* **-EPERM** if *timer* is in a map that doesn't have any user references.
* The user space should either hold a file descriptor to a map with timers
* or pin such map in bpffs. When map is unpinned or file descriptor is
* closed all timers in the map will be cancelled and freed.
*/
static long (* const bpf_timer_init)(struct bpf_timer *timer, void *map, __u64 flags) = (void *) 169;
/*
* bpf_timer_set_callback
*
* Configure the timer to call *callback_fn* static function.
*
* Returns
* 0 on success.
* **-EINVAL** if *timer* was not initialized with bpf_timer_init() earlier.
* **-EPERM** if *timer* is in a map that doesn't have any user references.
* The user space should either hold a file descriptor to a map with timers
* or pin such map in bpffs. When map is unpinned or file descriptor is
* closed all timers in the map will be cancelled and freed.
*/
static long (* const bpf_timer_set_callback)(struct bpf_timer *timer, void *callback_fn) = (void *) 170;
/*
* bpf_timer_start
*
* Set timer expiration N nanoseconds from the current time. The
* configured callback will be invoked in soft irq context on some cpu
* and will not repeat unless another bpf_timer_start() is made.
* In such case the next invocation can migrate to a different cpu.
* Since struct bpf_timer is a field inside map element the map
* owns the timer. The bpf_timer_set_callback() will increment refcnt
* of BPF program to make sure that callback_fn code stays valid.
* When user space reference to a map reaches zero all timers
* in a map are cancelled and corresponding program's refcnts are
* decremented. This is done to make sure that Ctrl-C of a user
* process doesn't leave any timers running. If map is pinned in
* bpffs the callback_fn can re-arm itself indefinitely.
* bpf_map_update/delete_elem() helpers and user space sys_bpf commands
* cancel and free the timer in the given map element.
* The map can contain timers that invoke callback_fn-s from different
* programs. The same callback_fn can serve different timers from
* different maps if key/value layout matches across maps.
* Every bpf_timer_set_callback() can have different callback_fn.
*
* *flags* can be one of:
*
* **BPF_F_TIMER_ABS**
* Start the timer in absolute expire value instead of the
* default relative one.
* **BPF_F_TIMER_CPU_PIN**
* Timer will be pinned to the CPU of the caller.
*
*
* Returns
* 0 on success.
* **-EINVAL** if *timer* was not initialized with bpf_timer_init() earlier
* or invalid *flags* are passed.
*/
static long (* const bpf_timer_start)(struct bpf_timer *timer, __u64 nsecs, __u64 flags) = (void *) 171;
/*
* bpf_timer_cancel
*
* Cancel the timer and wait for callback_fn to finish if it was running.
*
* Returns
* 0 if the timer was not active.
* 1 if the timer was active.
* **-EINVAL** if *timer* was not initialized with bpf_timer_init() earlier.
* **-EDEADLK** if callback_fn tried to call bpf_timer_cancel() on its
* own timer which would have led to a deadlock otherwise.
*/
static long (* const bpf_timer_cancel)(struct bpf_timer *timer) = (void *) 172;
/*
* bpf_get_func_ip
*
* Get address of the traced function (for tracing and kprobe programs).
*
* When called for kprobe program attached as uprobe it returns
* probe address for both entry and return uprobe.
*
*
* Returns
* Address of the traced function for kprobe.
* 0 for kprobes placed within the function (not at the entry).
* Address of the probe for uprobe and return uprobe.
*/
static __u64 (* const bpf_get_func_ip)(void *ctx) = (void *) 173;
/*
* bpf_get_attach_cookie
*
* Get bpf_cookie value provided (optionally) during the program
* attachment. It might be different for each individual
* attachment, even if BPF program itself is the same.
* Expects BPF program context *ctx* as a first argument.
*
* Supported for the following program types:
* - kprobe/uprobe;
* - tracepoint;
* - perf_event.
*
* Returns
* Value specified by user at BPF link creation/attachment time
* or 0, if it was not specified.
*/
static __u64 (* const bpf_get_attach_cookie)(void *ctx) = (void *) 174;
/*
* bpf_task_pt_regs
*
* Get the struct pt_regs associated with **task**.
*
* Returns
* A pointer to struct pt_regs.
*/
static long (* const bpf_task_pt_regs)(struct task_struct *task) = (void *) 175;
/*
* bpf_get_branch_snapshot
*
* Get branch trace from hardware engines like Intel LBR. The
* hardware engine is stopped shortly after the helper is
* called. Therefore, the user need to filter branch entries
* based on the actual use case. To capture branch trace
* before the trigger point of the BPF program, the helper
* should be called at the beginning of the BPF program.
*
* The data is stored as struct perf_branch_entry into output
* buffer *entries*. *size* is the size of *entries* in bytes.
* *flags* is reserved for now and must be zero.
*
*
* Returns
* On success, number of bytes written to *buf*. On error, a
* negative value.
*
* **-EINVAL** if *flags* is not zero.
*
* **-ENOENT** if architecture does not support branch records.
*/
static long (* const bpf_get_branch_snapshot)(void *entries, __u32 size, __u64 flags) = (void *) 176;
/*
* bpf_trace_vprintk
*
* Behaves like **bpf_trace_printk**\ () helper, but takes an array of u64
* to format and can handle more format args as a result.
*
* Arguments are to be used as in **bpf_seq_printf**\ () helper.
*
* Returns
* The number of bytes written to the buffer, or a negative error
* in case of failure.
*/
static long (* const bpf_trace_vprintk)(const char *fmt, __u32 fmt_size, const void *data, __u32 data_len) = (void *) 177;
/*
* bpf_skc_to_unix_sock
*
* Dynamically cast a *sk* pointer to a *unix_sock* pointer.
*
* Returns
* *sk* if casting is valid, or **NULL** otherwise.
*/
static struct unix_sock *(* const bpf_skc_to_unix_sock)(void *sk) = (void *) 178;
/*
* bpf_kallsyms_lookup_name
*
* Get the address of a kernel symbol, returned in *res*. *res* is
* set to 0 if the symbol is not found.
*
* Returns
* On success, zero. On error, a negative value.
*
* **-EINVAL** if *flags* is not zero.
*
* **-EINVAL** if string *name* is not the same size as *name_sz*.
*
* **-ENOENT** if symbol is not found.
*
* **-EPERM** if caller does not have permission to obtain kernel address.
*/
static long (* const bpf_kallsyms_lookup_name)(const char *name, int name_sz, int flags, __u64 *res) = (void *) 179;
/*
* bpf_find_vma
*
* Find vma of *task* that contains *addr*, call *callback_fn*
* function with *task*, *vma*, and *callback_ctx*.
* The *callback_fn* should be a static function and
* the *callback_ctx* should be a pointer to the stack.
* The *flags* is used to control certain aspects of the helper.
* Currently, the *flags* must be 0.
*
* The expected callback signature is
*
* long (\*callback_fn)(struct task_struct \*task, struct vm_area_struct \*vma, void \*callback_ctx);
*
*
* Returns
* 0 on success.
* **-ENOENT** if *task->mm* is NULL, or no vma contains *addr*.
* **-EBUSY** if failed to try lock mmap_lock.
* **-EINVAL** for invalid **flags**.
*/
static long (* const bpf_find_vma)(struct task_struct *task, __u64 addr, void *callback_fn, void *callback_ctx, __u64 flags) = (void *) 180;
/*
* bpf_loop
*
* For **nr_loops**, call **callback_fn** function
* with **callback_ctx** as the context parameter.
* The **callback_fn** should be a static function and
* the **callback_ctx** should be a pointer to the stack.
* The **flags** is used to control certain aspects of the helper.
* Currently, the **flags** must be 0. Currently, nr_loops is
* limited to 1 << 23 (~8 million) loops.
*
* long (\*callback_fn)(u32 index, void \*ctx);
*
* where **index** is the current index in the loop. The index
* is zero-indexed.
*
* If **callback_fn** returns 0, the helper will continue to the next
* loop. If return value is 1, the helper will skip the rest of
* the loops and return. Other return values are not used now,
* and will be rejected by the verifier.
*
*
* Returns
* The number of loops performed, **-EINVAL** for invalid **flags**,
* **-E2BIG** if **nr_loops** exceeds the maximum number of loops.
*/
static long (* const bpf_loop)(__u32 nr_loops, void *callback_fn, void *callback_ctx, __u64 flags) = (void *) 181;
/*
* bpf_strncmp
*
* Do strncmp() between **s1** and **s2**. **s1** doesn't need
* to be null-terminated and **s1_sz** is the maximum storage
* size of **s1**. **s2** must be a read-only string.
*
* Returns
* An integer less than, equal to, or greater than zero
* if the first **s1_sz** bytes of **s1** is found to be
* less than, to match, or be greater than **s2**.
*/
static long (* const bpf_strncmp)(const char *s1, __u32 s1_sz, const char *s2) = (void *) 182;
/*
* bpf_get_func_arg
*
* Get **n**-th argument register (zero based) of the traced function (for tracing programs)
* returned in **value**.
*
*
* Returns
* 0 on success.
* **-EINVAL** if n >= argument register count of traced function.
*/
static long (* const bpf_get_func_arg)(void *ctx, __u32 n, __u64 *value) = (void *) 183;
/*
* bpf_get_func_ret
*
* Get return value of the traced function (for tracing programs)
* in **value**.
*
*
* Returns
* 0 on success.
* **-EOPNOTSUPP** for tracing programs other than BPF_TRACE_FEXIT or BPF_MODIFY_RETURN.
*/
static long (* const bpf_get_func_ret)(void *ctx, __u64 *value) = (void *) 184;
/*
* bpf_get_func_arg_cnt
*
* Get number of registers of the traced function (for tracing programs) where
* function arguments are stored in these registers.
*
*
* Returns
* The number of argument registers of the traced function.
*/
static long (* const bpf_get_func_arg_cnt)(void *ctx) = (void *) 185;
/*
* bpf_get_retval
*
* Get the BPF program's return value that will be returned to the upper layers.
*
* This helper is currently supported by cgroup programs and only by the hooks
* where BPF program's return value is returned to the userspace via errno.
*
* Returns
* The BPF program's return value.
*/
static int (* const bpf_get_retval)(void) = (void *) 186;
/*
* bpf_set_retval
*
* Set the BPF program's return value that will be returned to the upper layers.
*
* This helper is currently supported by cgroup programs and only by the hooks
* where BPF program's return value is returned to the userspace via errno.
*
* Note that there is the following corner case where the program exports an error
* via bpf_set_retval but signals success via 'return 1':
*
* bpf_set_retval(-EPERM);
* return 1;
*
* In this case, the BPF program's return value will use helper's -EPERM. This
* still holds true for cgroup/bind{4,6} which supports extra 'return 3' success case.
*
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static int (* const bpf_set_retval)(int retval) = (void *) 187;
/*
* bpf_xdp_get_buff_len
*
* Get the total size of a given xdp buff (linear and paged area)
*
* Returns
* The total size of a given xdp buffer.
*/
static __u64 (* const bpf_xdp_get_buff_len)(struct xdp_md *xdp_md) = (void *) 188;
/*
* bpf_xdp_load_bytes
*
* This helper is provided as an easy way to load data from a
* xdp buffer. It can be used to load *len* bytes from *offset* from
* the frame associated to *xdp_md*, into the buffer pointed by
* *buf*.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_xdp_load_bytes)(struct xdp_md *xdp_md, __u32 offset, void *buf, __u32 len) = (void *) 189;
/*
* bpf_xdp_store_bytes
*
* Store *len* bytes from buffer *buf* into the frame
* associated to *xdp_md*, at *offset*.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_xdp_store_bytes)(struct xdp_md *xdp_md, __u32 offset, void *buf, __u32 len) = (void *) 190;
/*
* bpf_copy_from_user_task
*
* Read *size* bytes from user space address *user_ptr* in *tsk*'s
* address space, and stores the data in *dst*. *flags* is not
* used yet and is provided for future extensibility. This helper
* can only be used by sleepable programs.
*
* Returns
* 0 on success, or a negative error in case of failure. On error
* *dst* buffer is zeroed out.
*/
static long (* const bpf_copy_from_user_task)(void *dst, __u32 size, const void *user_ptr, struct task_struct *tsk, __u64 flags) = (void *) 191;
/*
* bpf_skb_set_tstamp
*
* Change the __sk_buff->tstamp_type to *tstamp_type*
* and set *tstamp* to the __sk_buff->tstamp together.
*
* If there is no need to change the __sk_buff->tstamp_type,
* the tstamp value can be directly written to __sk_buff->tstamp
* instead.
*
* BPF_SKB_TSTAMP_DELIVERY_MONO is the only tstamp that
* will be kept during bpf_redirect_*(). A non zero
* *tstamp* must be used with the BPF_SKB_TSTAMP_DELIVERY_MONO
* *tstamp_type*.
*
* A BPF_SKB_TSTAMP_UNSPEC *tstamp_type* can only be used
* with a zero *tstamp*.
*
* Only IPv4 and IPv6 skb->protocol are supported.
*
* This function is most useful when it needs to set a
* mono delivery time to __sk_buff->tstamp and then
* bpf_redirect_*() to the egress of an iface. For example,
* changing the (rcv) timestamp in __sk_buff->tstamp at
* ingress to a mono delivery time and then bpf_redirect_*()
* to sch_fq@phy-dev.
*
* Returns
* 0 on success.
* **-EINVAL** for invalid input
* **-EOPNOTSUPP** for unsupported protocol
*/
static long (* const bpf_skb_set_tstamp)(struct __sk_buff *skb, __u64 tstamp, __u32 tstamp_type) = (void *) 192;
/*
* bpf_ima_file_hash
*
* Returns a calculated IMA hash of the *file*.
* If the hash is larger than *size*, then only *size*
* bytes will be copied to *dst*
*
* Returns
* The **hash_algo** is returned on success,
* **-EOPNOTSUP** if the hash calculation failed or **-EINVAL** if
* invalid arguments are passed.
*/
static long (* const bpf_ima_file_hash)(struct file *file, void *dst, __u32 size) = (void *) 193;
/*
* bpf_kptr_xchg
*
* Exchange kptr at pointer *map_value* with *ptr*, and return the
* old value. *ptr* can be NULL, otherwise it must be a referenced
* pointer which will be released when this helper is called.
*
* Returns
* The old value of kptr (which can be NULL). The returned pointer
* if not NULL, is a reference which must be released using its
* corresponding release function, or moved into a BPF map before
* program exit.
*/
static void *(* const bpf_kptr_xchg)(void *map_value, void *ptr) = (void *) 194;
/*
* bpf_map_lookup_percpu_elem
*
* Perform a lookup in *percpu map* for an entry associated to
* *key* on *cpu*.
*
* Returns
* Map value associated to *key* on *cpu*, or **NULL** if no entry
* was found or *cpu* is invalid.
*/
static void *(* const bpf_map_lookup_percpu_elem)(void *map, const void *key, __u32 cpu) = (void *) 195;
/*
* bpf_skc_to_mptcp_sock
*
* Dynamically cast a *sk* pointer to a *mptcp_sock* pointer.
*
* Returns
* *sk* if casting is valid, or **NULL** otherwise.
*/
static struct mptcp_sock *(* const bpf_skc_to_mptcp_sock)(void *sk) = (void *) 196;
/*
* bpf_dynptr_from_mem
*
* Get a dynptr to local memory *data*.
*
* *data* must be a ptr to a map value.
* The maximum *size* supported is DYNPTR_MAX_SIZE.
* *flags* is currently unused.
*
* Returns
* 0 on success, -E2BIG if the size exceeds DYNPTR_MAX_SIZE,
* -EINVAL if flags is not 0.
*/
static long (* const bpf_dynptr_from_mem)(void *data, __u32 size, __u64 flags, struct bpf_dynptr *ptr) = (void *) 197;
/*
* bpf_ringbuf_reserve_dynptr
*
* Reserve *size* bytes of payload in a ring buffer *ringbuf*
* through the dynptr interface. *flags* must be 0.
*
* Please note that a corresponding bpf_ringbuf_submit_dynptr or
* bpf_ringbuf_discard_dynptr must be called on *ptr*, even if the
* reservation fails. This is enforced by the verifier.
*
* Returns
* 0 on success, or a negative error in case of failure.
*/
static long (* const bpf_ringbuf_reserve_dynptr)(void *ringbuf, __u32 size, __u64 flags, struct bpf_dynptr *ptr) = (void *) 198;
/*
* bpf_ringbuf_submit_dynptr
*
* Submit reserved ring buffer sample, pointed to by *data*,
* through the dynptr interface. This is a no-op if the dynptr is
* invalid/null.
*
* For more information on *flags*, please see
* 'bpf_ringbuf_submit'.
*
* Returns
* Nothing. Always succeeds.
*/
static void (* const bpf_ringbuf_submit_dynptr)(struct bpf_dynptr *ptr, __u64 flags) = (void *) 199;
/*
* bpf_ringbuf_discard_dynptr
*
* Discard reserved ring buffer sample through the dynptr
* interface. This is a no-op if the dynptr is invalid/null.
*
* For more information on *flags*, please see
* 'bpf_ringbuf_discard'.
*
* Returns
* Nothing. Always succeeds.
*/
static void (* const bpf_ringbuf_discard_dynptr)(struct bpf_dynptr *ptr, __u64 flags) = (void *) 200;
/*
* bpf_dynptr_read
*
* Read *len* bytes from *src* into *dst*, starting from *offset*
* into *src*.
* *flags* is currently unused.
*
* Returns
* 0 on success, -E2BIG if *offset* + *len* exceeds the length
* of *src*'s data, -EINVAL if *src* is an invalid dynptr or if
* *flags* is not 0.
*/
static long (* const bpf_dynptr_read)(void *dst, __u32 len, const struct bpf_dynptr *src, __u32 offset, __u64 flags) = (void *) 201;
/*
* bpf_dynptr_write
*
* Write *len* bytes from *src* into *dst*, starting from *offset*
* into *dst*.
*
* *flags* must be 0 except for skb-type dynptrs.
*
* For skb-type dynptrs:
* * All data slices of the dynptr are automatically
* invalidated after **bpf_dynptr_write**\ (). This is
* because writing may pull the skb and change the
* underlying packet buffer.
*
* * For *flags*, please see the flags accepted by
* **bpf_skb_store_bytes**\ ().
*
* Returns
* 0 on success, -E2BIG if *offset* + *len* exceeds the length
* of *dst*'s data, -EINVAL if *dst* is an invalid dynptr or if *dst*
* is a read-only dynptr or if *flags* is not correct. For skb-type dynptrs,
* other errors correspond to errors returned by **bpf_skb_store_bytes**\ ().
*/
static long (* const bpf_dynptr_write)(const struct bpf_dynptr *dst, __u32 offset, void *src, __u32 len, __u64 flags) = (void *) 202;
/*
* bpf_dynptr_data
*
* Get a pointer to the underlying dynptr data.
*
* *len* must be a statically known value. The returned data slice
* is invalidated whenever the dynptr is invalidated.
*
* skb and xdp type dynptrs may not use bpf_dynptr_data. They should
* instead use bpf_dynptr_slice and bpf_dynptr_slice_rdwr.
*
* Returns
* Pointer to the underlying dynptr data, NULL if the dynptr is
* read-only, if the dynptr is invalid, or if the offset and length
* is out of bounds.
*/
static void *(* const bpf_dynptr_data)(const struct bpf_dynptr *ptr, __u32 offset, __u32 len) = (void *) 203;
/*
* bpf_tcp_raw_gen_syncookie_ipv4
*
* Try to issue a SYN cookie for the packet with corresponding
* IPv4/TCP headers, *iph* and *th*, without depending on a
* listening socket.
*
* *iph* points to the IPv4 header.
*
* *th* points to the start of the TCP header, while *th_len*
* contains the length of the TCP header (at least
* **sizeof**\ (**struct tcphdr**)).
*
* Returns
* On success, lower 32 bits hold the generated SYN cookie in
* followed by 16 bits which hold the MSS value for that cookie,
* and the top 16 bits are unused.
*
* On failure, the returned value is one of the following:
*
* **-EINVAL** if *th_len* is invalid.
*/
static __s64 (* const bpf_tcp_raw_gen_syncookie_ipv4)(struct iphdr *iph, struct tcphdr *th, __u32 th_len) = (void *) 204;
/*
* bpf_tcp_raw_gen_syncookie_ipv6
*
* Try to issue a SYN cookie for the packet with corresponding
* IPv6/TCP headers, *iph* and *th*, without depending on a
* listening socket.
*
* *iph* points to the IPv6 header.
*
* *th* points to the start of the TCP header, while *th_len*
* contains the length of the TCP header (at least
* **sizeof**\ (**struct tcphdr**)).
*
* Returns
* On success, lower 32 bits hold the generated SYN cookie in
* followed by 16 bits which hold the MSS value for that cookie,
* and the top 16 bits are unused.
*
* On failure, the returned value is one of the following:
*
* **-EINVAL** if *th_len* is invalid.
*
* **-EPROTONOSUPPORT** if CONFIG_IPV6 is not builtin.
*/
static __s64 (* const bpf_tcp_raw_gen_syncookie_ipv6)(struct ipv6hdr *iph, struct tcphdr *th, __u32 th_len) = (void *) 205;
/*
* bpf_tcp_raw_check_syncookie_ipv4
*
* Check whether *iph* and *th* contain a valid SYN cookie ACK
* without depending on a listening socket.
*
* *iph* points to the IPv4 header.
*
* *th* points to the TCP header.
*
* Returns
* 0 if *iph* and *th* are a valid SYN cookie ACK.
*
* On failure, the returned value is one of the following:
*
* **-EACCES** if the SYN cookie is not valid.
*/
static long (* const bpf_tcp_raw_check_syncookie_ipv4)(struct iphdr *iph, struct tcphdr *th) = (void *) 206;
/*
* bpf_tcp_raw_check_syncookie_ipv6
*
* Check whether *iph* and *th* contain a valid SYN cookie ACK
* without depending on a listening socket.
*
* *iph* points to the IPv6 header.
*
* *th* points to the TCP header.
*
* Returns
* 0 if *iph* and *th* are a valid SYN cookie ACK.
*
* On failure, the returned value is one of the following:
*
* **-EACCES** if the SYN cookie is not valid.
*
* **-EPROTONOSUPPORT** if CONFIG_IPV6 is not builtin.
*/
static long (* const bpf_tcp_raw_check_syncookie_ipv6)(struct ipv6hdr *iph, struct tcphdr *th) = (void *) 207;
/*
* bpf_ktime_get_tai_ns
*
* A nonsettable system-wide clock derived from wall-clock time but
* ignoring leap seconds. This clock does not experience
* discontinuities and backwards jumps caused by NTP inserting leap
* seconds as CLOCK_REALTIME does.
*
* See: **clock_gettime**\ (**CLOCK_TAI**)
*
* Returns
* Current *ktime*.
*/
static __u64 (* const bpf_ktime_get_tai_ns)(void) = (void *) 208;
/*
* bpf_user_ringbuf_drain
*
* Drain samples from the specified user ring buffer, and invoke
* the provided callback for each such sample:
*
* long (\*callback_fn)(const struct bpf_dynptr \*dynptr, void \*ctx);
*
* If **callback_fn** returns 0, the helper will continue to try
* and drain the next sample, up to a maximum of
* BPF_MAX_USER_RINGBUF_SAMPLES samples. If the return value is 1,
* the helper will skip the rest of the samples and return. Other
* return values are not used now, and will be rejected by the
* verifier.
*
* Returns
* The number of drained samples if no error was encountered while
* draining samples, or 0 if no samples were present in the ring
* buffer. If a user-space producer was epoll-waiting on this map,
* and at least one sample was drained, they will receive an event
* notification notifying them of available space in the ring
* buffer. If the BPF_RB_NO_WAKEUP flag is passed to this
* function, no wakeup notification will be sent. If the
* BPF_RB_FORCE_WAKEUP flag is passed, a wakeup notification will
* be sent even if no sample was drained.
*
* On failure, the returned value is one of the following:
*
* **-EBUSY** if the ring buffer is contended, and another calling
* context was concurrently draining the ring buffer.
*
* **-EINVAL** if user-space is not properly tracking the ring
* buffer due to the producer position not being aligned to 8
* bytes, a sample not being aligned to 8 bytes, or the producer
* position not matching the advertised length of a sample.
*
* **-E2BIG** if user-space has tried to publish a sample which is
* larger than the size of the ring buffer, or which cannot fit
* within a struct bpf_dynptr.
*/
static long (* const bpf_user_ringbuf_drain)(void *map, void *callback_fn, void *ctx, __u64 flags) = (void *) 209;
/*
* bpf_cgrp_storage_get
*
* Get a bpf_local_storage from the *cgroup*.
*
* Logically, it could be thought of as getting the value from
* a *map* with *cgroup* as the **key**. From this
* perspective, the usage is not much different from
* **bpf_map_lookup_elem**\ (*map*, **&**\ *cgroup*) except this
* helper enforces the key must be a cgroup struct and the map must also
* be a **BPF_MAP_TYPE_CGRP_STORAGE**.
*
* In reality, the local-storage value is embedded directly inside of the
* *cgroup* object itself, rather than being located in the
* **BPF_MAP_TYPE_CGRP_STORAGE** map. When the local-storage value is
* queried for some *map* on a *cgroup* object, the kernel will perform an
* O(n) iteration over all of the live local-storage values for that
* *cgroup* object until the local-storage value for the *map* is found.
*
* An optional *flags* (**BPF_LOCAL_STORAGE_GET_F_CREATE**) can be
* used such that a new bpf_local_storage will be
* created if one does not exist. *value* can be used
* together with **BPF_LOCAL_STORAGE_GET_F_CREATE** to specify
* the initial value of a bpf_local_storage. If *value* is
* **NULL**, the new bpf_local_storage will be zero initialized.
*
* Returns
* A bpf_local_storage pointer is returned on success.
*
* **NULL** if not found or there was an error in adding
* a new bpf_local_storage.
*/
static void *(* const bpf_cgrp_storage_get)(void *map, struct cgroup *cgroup, void *value, __u64 flags) = (void *) 210;
/*
* bpf_cgrp_storage_delete
*
* Delete a bpf_local_storage from a *cgroup*.
*
* Returns
* 0 on success.
*
* **-ENOENT** if the bpf_local_storage cannot be found.
*/
static long (* const bpf_cgrp_storage_delete)(void *map, struct cgroup *cgroup) = (void *) 211;
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