mirror of
https://github.com/tailscale/tailscale.git
synced 2024-11-25 19:15:34 +00:00
util/linuxfw: remove yet-unused code to fix linux/arm64 crash
The util/linuxfw/iptables.go had a bunch of code that wasn't yet used (in prep for future work) but because of its imports, ended up initializing code deep within gvisor that panicked on init on arm64 systems not using 4KB pages. This deletes the unused code to delete the imports and remove the panic. We can then cherry-pick this back to the branch and restore it later in a different way. A new test makes sure we don't regress in the future by depending on the panicking package in question. Fixes #8658 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This commit is contained in:
Brad Fitzpatrick
Brad Fitzpatrick
parent
7560435eb5
commit
88cc0ad9f7
@ -77,20 +77,6 @@ tailscale.com/cmd/derper dependencies: (generated by github.com/tailscale/depawa
|
||||
google.golang.org/protobuf/runtime/protoimpl from github.com/golang/protobuf/proto+
|
||||
google.golang.org/protobuf/types/descriptorpb from google.golang.org/protobuf/reflect/protodesc
|
||||
google.golang.org/protobuf/types/known/timestamppb from github.com/prometheus/client_golang/prometheus+
|
||||
L gvisor.dev/gvisor/pkg/abi from gvisor.dev/gvisor/pkg/abi/linux
|
||||
L 💣 gvisor.dev/gvisor/pkg/abi/linux from tailscale.com/util/linuxfw
|
||||
L gvisor.dev/gvisor/pkg/bits from gvisor.dev/gvisor/pkg/abi/linux
|
||||
L gvisor.dev/gvisor/pkg/context from gvisor.dev/gvisor/pkg/abi/linux
|
||||
L 💣 gvisor.dev/gvisor/pkg/gohacks from gvisor.dev/gvisor/pkg/abi/linux+
|
||||
L 💣 gvisor.dev/gvisor/pkg/hostarch from gvisor.dev/gvisor/pkg/abi/linux+
|
||||
L gvisor.dev/gvisor/pkg/linewriter from gvisor.dev/gvisor/pkg/log
|
||||
L gvisor.dev/gvisor/pkg/log from gvisor.dev/gvisor/pkg/context
|
||||
L gvisor.dev/gvisor/pkg/marshal from gvisor.dev/gvisor/pkg/abi/linux+
|
||||
L 💣 gvisor.dev/gvisor/pkg/marshal/primitive from gvisor.dev/gvisor/pkg/abi/linux
|
||||
L 💣 gvisor.dev/gvisor/pkg/state from gvisor.dev/gvisor/pkg/abi/linux+
|
||||
L gvisor.dev/gvisor/pkg/state/wire from gvisor.dev/gvisor/pkg/state
|
||||
L 💣 gvisor.dev/gvisor/pkg/sync from gvisor.dev/gvisor/pkg/linewriter+
|
||||
L gvisor.dev/gvisor/pkg/waiter from gvisor.dev/gvisor/pkg/context
|
||||
nhooyr.io/websocket from tailscale.com/cmd/derper+
|
||||
nhooyr.io/websocket/internal/errd from nhooyr.io/websocket
|
||||
nhooyr.io/websocket/internal/xsync from nhooyr.io/websocket
|
||||
@ -156,7 +142,7 @@ tailscale.com/cmd/derper dependencies: (generated by github.com/tailscale/depawa
|
||||
tailscale.com/util/dnsname from tailscale.com/hostinfo+
|
||||
tailscale.com/util/httpm from tailscale.com/client/tailscale
|
||||
tailscale.com/util/lineread from tailscale.com/hostinfo+
|
||||
L 💣 tailscale.com/util/linuxfw from tailscale.com/net/netns
|
||||
L tailscale.com/util/linuxfw from tailscale.com/net/netns
|
||||
tailscale.com/util/mak from tailscale.com/syncs+
|
||||
tailscale.com/util/multierr from tailscale.com/health+
|
||||
tailscale.com/util/set from tailscale.com/health+
|
||||
|
||||
@ -55,20 +55,6 @@ tailscale.com/cmd/tailscale dependencies: (generated by github.com/tailscale/dep
|
||||
go4.org/netipx from tailscale.com/wgengine/filter
|
||||
W 💣 golang.zx2c4.com/wireguard/windows/tunnel/winipcfg from tailscale.com/net/interfaces+
|
||||
gopkg.in/yaml.v2 from sigs.k8s.io/yaml
|
||||
L gvisor.dev/gvisor/pkg/abi from gvisor.dev/gvisor/pkg/abi/linux
|
||||
L 💣 gvisor.dev/gvisor/pkg/abi/linux from tailscale.com/util/linuxfw
|
||||
L gvisor.dev/gvisor/pkg/bits from gvisor.dev/gvisor/pkg/abi/linux
|
||||
L gvisor.dev/gvisor/pkg/context from gvisor.dev/gvisor/pkg/abi/linux
|
||||
L 💣 gvisor.dev/gvisor/pkg/gohacks from gvisor.dev/gvisor/pkg/abi/linux+
|
||||
L 💣 gvisor.dev/gvisor/pkg/hostarch from gvisor.dev/gvisor/pkg/abi/linux+
|
||||
L gvisor.dev/gvisor/pkg/linewriter from gvisor.dev/gvisor/pkg/log
|
||||
L gvisor.dev/gvisor/pkg/log from gvisor.dev/gvisor/pkg/context
|
||||
L gvisor.dev/gvisor/pkg/marshal from gvisor.dev/gvisor/pkg/abi/linux+
|
||||
L 💣 gvisor.dev/gvisor/pkg/marshal/primitive from gvisor.dev/gvisor/pkg/abi/linux
|
||||
L 💣 gvisor.dev/gvisor/pkg/state from gvisor.dev/gvisor/pkg/abi/linux+
|
||||
L gvisor.dev/gvisor/pkg/state/wire from gvisor.dev/gvisor/pkg/state
|
||||
L 💣 gvisor.dev/gvisor/pkg/sync from gvisor.dev/gvisor/pkg/linewriter+
|
||||
L gvisor.dev/gvisor/pkg/waiter from gvisor.dev/gvisor/pkg/context
|
||||
k8s.io/client-go/util/homedir from tailscale.com/cmd/tailscale/cli
|
||||
nhooyr.io/websocket from tailscale.com/derp/derphttp+
|
||||
nhooyr.io/websocket/internal/errd from nhooyr.io/websocket
|
||||
@ -148,7 +134,7 @@ tailscale.com/cmd/tailscale dependencies: (generated by github.com/tailscale/dep
|
||||
tailscale.com/util/groupmember from tailscale.com/cmd/tailscale/cli
|
||||
tailscale.com/util/httpm from tailscale.com/client/tailscale
|
||||
tailscale.com/util/lineread from tailscale.com/net/interfaces+
|
||||
L 💣 tailscale.com/util/linuxfw from tailscale.com/net/netns
|
||||
L tailscale.com/util/linuxfw from tailscale.com/net/netns
|
||||
tailscale.com/util/mak from tailscale.com/net/netcheck+
|
||||
tailscale.com/util/multierr from tailscale.com/control/controlhttp+
|
||||
tailscale.com/util/must from tailscale.com/cmd/tailscale/cli
|
||||
|
||||
@ -162,18 +162,13 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
|
||||
go4.org/netipx from tailscale.com/ipn/ipnlocal+
|
||||
W 💣 golang.zx2c4.com/wintun from github.com/tailscale/wireguard-go/tun+
|
||||
W 💣 golang.zx2c4.com/wireguard/windows/tunnel/winipcfg from tailscale.com/net/dns+
|
||||
L gvisor.dev/gvisor/pkg/abi from gvisor.dev/gvisor/pkg/abi/linux
|
||||
L 💣 gvisor.dev/gvisor/pkg/abi/linux from tailscale.com/util/linuxfw
|
||||
gvisor.dev/gvisor/pkg/atomicbitops from gvisor.dev/gvisor/pkg/tcpip+
|
||||
gvisor.dev/gvisor/pkg/bits from gvisor.dev/gvisor/pkg/bufferv2+
|
||||
gvisor.dev/gvisor/pkg/bits from gvisor.dev/gvisor/pkg/bufferv2
|
||||
💣 gvisor.dev/gvisor/pkg/bufferv2 from gvisor.dev/gvisor/pkg/tcpip+
|
||||
gvisor.dev/gvisor/pkg/context from gvisor.dev/gvisor/pkg/refs+
|
||||
gvisor.dev/gvisor/pkg/context from gvisor.dev/gvisor/pkg/refs
|
||||
💣 gvisor.dev/gvisor/pkg/gohacks from gvisor.dev/gvisor/pkg/state/wire+
|
||||
L 💣 gvisor.dev/gvisor/pkg/hostarch from gvisor.dev/gvisor/pkg/abi/linux+
|
||||
gvisor.dev/gvisor/pkg/linewriter from gvisor.dev/gvisor/pkg/log
|
||||
gvisor.dev/gvisor/pkg/log from gvisor.dev/gvisor/pkg/context+
|
||||
L gvisor.dev/gvisor/pkg/marshal from gvisor.dev/gvisor/pkg/abi/linux+
|
||||
L 💣 gvisor.dev/gvisor/pkg/marshal/primitive from gvisor.dev/gvisor/pkg/abi/linux
|
||||
gvisor.dev/gvisor/pkg/rand from gvisor.dev/gvisor/pkg/tcpip/network/hash+
|
||||
gvisor.dev/gvisor/pkg/refs from gvisor.dev/gvisor/pkg/bufferv2+
|
||||
💣 gvisor.dev/gvisor/pkg/sleep from gvisor.dev/gvisor/pkg/tcpip/transport/tcp
|
||||
@ -333,7 +328,7 @@ tailscale.com/cmd/tailscaled dependencies: (generated by github.com/tailscale/de
|
||||
💣 tailscale.com/util/hashx from tailscale.com/util/deephash
|
||||
tailscale.com/util/httpm from tailscale.com/client/tailscale+
|
||||
tailscale.com/util/lineread from tailscale.com/hostinfo+
|
||||
L 💣 tailscale.com/util/linuxfw from tailscale.com/net/netns+
|
||||
L tailscale.com/util/linuxfw from tailscale.com/net/netns+
|
||||
tailscale.com/util/mak from tailscale.com/control/controlclient+
|
||||
tailscale.com/util/multierr from tailscale.com/control/controlclient+
|
||||
tailscale.com/util/must from tailscale.com/logpolicy
|
||||
|
||||
@ -20,17 +20,15 @@ func TestDeps(t *testing.T) {
|
||||
GOOS: "darwin",
|
||||
GOARCH: "arm64",
|
||||
BadDeps: map[string]string{
|
||||
"gvisor.dev/gvisor/pkg/hostarch": "will crash on non-4K page sizes",
|
||||
"gvisor.dev/gvisor/pkg/hostarch": "will crash on non-4K page sizes; see https://github.com/tailscale/tailscale/issues/8658",
|
||||
},
|
||||
}.Check(t)
|
||||
|
||||
deptest.DepChecker{
|
||||
GOOS: "linux",
|
||||
GOARCH: "arm64",
|
||||
GOOS: "linux",
|
||||
GOARCH: "arm64",
|
||||
BadDeps: map[string]string{
|
||||
// TODO: per https://github.com/tailscale/tailscale/issues/8658,
|
||||
// add this line too:
|
||||
// "gvisor.dev/gvisor/pkg/hostarch": "will crash on non-4K page sizes",
|
||||
"gvisor.dev/gvisor/pkg/hostarch": "will crash on non-4K page sizes; see https://github.com/tailscale/tailscale/issues/8658",
|
||||
},
|
||||
}.Check(t)
|
||||
}
|
||||
|
||||
@ -7,94 +7,13 @@
|
||||
package linuxfw
|
||||
|
||||
import (
|
||||
"encoding/hex"
|
||||
"errors"
|
||||
"fmt"
|
||||
"net"
|
||||
"net/netip"
|
||||
"strings"
|
||||
"unsafe"
|
||||
|
||||
"github.com/josharian/native"
|
||||
"golang.org/x/sys/unix"
|
||||
linuxabi "gvisor.dev/gvisor/pkg/abi/linux"
|
||||
"tailscale.com/net/netaddr"
|
||||
"tailscale.com/types/logger"
|
||||
)
|
||||
|
||||
type sockLen uint32
|
||||
|
||||
var (
|
||||
iptablesChainNames = map[int]string{
|
||||
linuxabi.NF_INET_PRE_ROUTING: "PREROUTING",
|
||||
linuxabi.NF_INET_LOCAL_IN: "INPUT",
|
||||
linuxabi.NF_INET_FORWARD: "FORWARD",
|
||||
linuxabi.NF_INET_LOCAL_OUT: "OUTPUT",
|
||||
linuxabi.NF_INET_POST_ROUTING: "POSTROUTING",
|
||||
}
|
||||
iptablesStandardChains = (func() map[string]bool {
|
||||
ret := make(map[string]bool)
|
||||
for _, v := range iptablesChainNames {
|
||||
ret[v] = true
|
||||
}
|
||||
return ret
|
||||
})()
|
||||
)
|
||||
|
||||
// DebugNetfilter prints debug information about iptables rules to the
|
||||
// provided log function.
|
||||
func DebugIptables(logf logger.Logf) error {
|
||||
for _, table := range []string{"filter", "nat", "raw"} {
|
||||
type chainAndEntry struct {
|
||||
chain string
|
||||
entry *entry
|
||||
}
|
||||
|
||||
// Collect all entries first so we can resolve jumps
|
||||
var (
|
||||
lastChain string
|
||||
ces []chainAndEntry
|
||||
chainOffsets = make(map[int]string)
|
||||
)
|
||||
err := enumerateIptablesTable(logf, table, func(chain string, entry *entry) error {
|
||||
if chain != lastChain {
|
||||
chainOffsets[entry.Offset] = chain
|
||||
lastChain = chain
|
||||
}
|
||||
|
||||
ces = append(ces, chainAndEntry{
|
||||
chain: lastChain,
|
||||
entry: entry,
|
||||
})
|
||||
return nil
|
||||
})
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
lastChain = ""
|
||||
for _, ce := range ces {
|
||||
if ce.chain != lastChain {
|
||||
logf("iptables: table=%s chain=%s", table, ce.chain)
|
||||
lastChain = ce.chain
|
||||
}
|
||||
|
||||
// Fixup jump
|
||||
if std, ok := ce.entry.Target.Data.(standardTarget); ok {
|
||||
if strings.HasPrefix(std.Verdict, "JUMP(") {
|
||||
var off int
|
||||
if _, err := fmt.Sscanf(std.Verdict, "JUMP(%d)", &off); err == nil {
|
||||
if jt, ok := chainOffsets[off]; ok {
|
||||
std.Verdict = "JUMP(" + jt + ")"
|
||||
ce.entry.Target.Data = std
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
logf("iptables: entry=%+v", ce.entry)
|
||||
}
|
||||
}
|
||||
// unused.
|
||||
return nil
|
||||
}
|
||||
|
||||
@ -106,721 +25,5 @@ type chainAndEntry struct {
|
||||
// syscall fails); when there are no iptables rules, it is valid for this
|
||||
// function to return 0, nil.
|
||||
func DetectIptables() (int, error) {
|
||||
dummyLog := func(string, ...any) {}
|
||||
|
||||
var (
|
||||
validRules int
|
||||
firstErr error
|
||||
)
|
||||
for _, table := range []string{"filter", "nat", "raw"} {
|
||||
err := enumerateIptablesTable(dummyLog, table, func(chain string, entry *entry) error {
|
||||
// If we have any rules other than basic 'ACCEPT' entries in a
|
||||
// standard chain, then we consider this a valid rule.
|
||||
switch {
|
||||
case !iptablesStandardChains[chain]:
|
||||
validRules++
|
||||
case entry.Target.Name != "standard":
|
||||
validRules++
|
||||
case entry.Target.Name == "standard" && entry.Target.Data.(standardTarget).Verdict != "ACCEPT":
|
||||
validRules++
|
||||
}
|
||||
return nil
|
||||
})
|
||||
if err != nil && firstErr == nil {
|
||||
firstErr = err
|
||||
}
|
||||
}
|
||||
|
||||
return validRules, firstErr
|
||||
}
|
||||
|
||||
func enumerateIptablesTable(logf logger.Logf, table string, cb func(string, *entry) error) error {
|
||||
ln, err := net.Listen("tcp4", ":0")
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
defer ln.Close()
|
||||
|
||||
tcpLn := ln.(*net.TCPListener)
|
||||
conn, err := tcpLn.SyscallConn()
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
|
||||
var tableName linuxabi.TableName
|
||||
copy(tableName[:], []byte(table))
|
||||
|
||||
tbl := linuxabi.IPTGetinfo{
|
||||
Name: tableName,
|
||||
}
|
||||
slt := sockLen(linuxabi.SizeOfIPTGetinfo)
|
||||
|
||||
var ctrlErr error
|
||||
err = conn.Control(func(fd uintptr) {
|
||||
_, _, errno := unix.Syscall6(
|
||||
unix.SYS_GETSOCKOPT,
|
||||
fd,
|
||||
uintptr(unix.SOL_IP),
|
||||
linuxabi.IPT_SO_GET_INFO,
|
||||
uintptr(unsafe.Pointer(&tbl)),
|
||||
uintptr(unsafe.Pointer(&slt)),
|
||||
0,
|
||||
)
|
||||
if errno != 0 {
|
||||
ctrlErr = errno
|
||||
return
|
||||
}
|
||||
})
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
if ctrlErr != nil {
|
||||
return ctrlErr
|
||||
}
|
||||
|
||||
if tbl.Size < 1 {
|
||||
return nil
|
||||
}
|
||||
|
||||
// Allocate enough space to be able to get all iptables information.
|
||||
entsBuf := make([]byte, linuxabi.SizeOfIPTGetEntries+tbl.Size)
|
||||
entsHdr := (*linuxabi.IPTGetEntries)(unsafe.Pointer(&entsBuf[0]))
|
||||
entsHdr.Name = tableName
|
||||
entsHdr.Size = tbl.Size
|
||||
|
||||
slt = sockLen(len(entsBuf))
|
||||
|
||||
err = conn.Control(func(fd uintptr) {
|
||||
_, _, errno := unix.Syscall6(
|
||||
unix.SYS_GETSOCKOPT,
|
||||
fd,
|
||||
uintptr(unix.SOL_IP),
|
||||
linuxabi.IPT_SO_GET_ENTRIES,
|
||||
uintptr(unsafe.Pointer(&entsBuf[0])),
|
||||
uintptr(unsafe.Pointer(&slt)),
|
||||
0,
|
||||
)
|
||||
if errno != 0 {
|
||||
ctrlErr = errno
|
||||
return
|
||||
}
|
||||
})
|
||||
if err != nil {
|
||||
return err
|
||||
}
|
||||
if ctrlErr != nil {
|
||||
return ctrlErr
|
||||
}
|
||||
|
||||
// Skip header
|
||||
entsBuf = entsBuf[linuxabi.SizeOfIPTGetEntries:]
|
||||
|
||||
var (
|
||||
totalOffset int
|
||||
currentChain string
|
||||
)
|
||||
for len(entsBuf) > 0 {
|
||||
parser := entryParser{
|
||||
buf: entsBuf,
|
||||
logf: logf,
|
||||
checkExtraBytes: true,
|
||||
}
|
||||
entry, err := parser.parseEntry(entsBuf)
|
||||
if err != nil {
|
||||
logf("iptables: err=%v", err)
|
||||
break
|
||||
}
|
||||
entry.Offset += totalOffset
|
||||
|
||||
// Don't pass 'ERROR' nodes to our caller
|
||||
if entry.Target.Name == "ERROR" {
|
||||
if parser.offset == len(entsBuf) {
|
||||
// all done
|
||||
break
|
||||
}
|
||||
|
||||
// New user-defined chain
|
||||
currentChain = entry.Target.Data.(errorTarget).ErrorName
|
||||
} else {
|
||||
// Detect if we're at a new chain based on the hook
|
||||
// offsets we fetched earlier.
|
||||
for i, he := range tbl.HookEntry {
|
||||
if int(he) == totalOffset {
|
||||
currentChain = iptablesChainNames[i]
|
||||
}
|
||||
}
|
||||
|
||||
// Now that we have everything, call our callback.
|
||||
if err := cb(currentChain, &entry); err != nil {
|
||||
return err
|
||||
}
|
||||
}
|
||||
|
||||
entsBuf = entsBuf[parser.offset:]
|
||||
totalOffset += parser.offset
|
||||
}
|
||||
return nil
|
||||
}
|
||||
|
||||
// TODO(andrew): convert to use cstruct
|
||||
type entryParser struct {
|
||||
buf []byte
|
||||
offset int
|
||||
|
||||
logf logger.Logf
|
||||
|
||||
// Set to 'true' to print debug messages about unused bytes returned
|
||||
// from the kernel
|
||||
checkExtraBytes bool
|
||||
}
|
||||
|
||||
func (p *entryParser) haveLen(ln int) bool {
|
||||
if len(p.buf)-p.offset < ln {
|
||||
return false
|
||||
}
|
||||
return true
|
||||
}
|
||||
|
||||
func (p *entryParser) assertLen(ln int) error {
|
||||
if !p.haveLen(ln) {
|
||||
return fmt.Errorf("need %d bytes: %w", ln, errBufferTooSmall)
|
||||
}
|
||||
return nil
|
||||
}
|
||||
|
||||
func (p *entryParser) getBytes(amt int) []byte {
|
||||
ret := p.buf[p.offset : p.offset+amt]
|
||||
p.offset += amt
|
||||
return ret
|
||||
}
|
||||
|
||||
func (p *entryParser) getByte() byte {
|
||||
ret := p.buf[p.offset]
|
||||
p.offset += 1
|
||||
return ret
|
||||
}
|
||||
|
||||
func (p *entryParser) get4() (ret [4]byte) {
|
||||
ret[0] = p.buf[p.offset+0]
|
||||
ret[1] = p.buf[p.offset+1]
|
||||
ret[2] = p.buf[p.offset+2]
|
||||
ret[3] = p.buf[p.offset+3]
|
||||
p.offset += 4
|
||||
return
|
||||
}
|
||||
|
||||
func (p *entryParser) setOffset(off, max int) error {
|
||||
// We can't go back
|
||||
if off < p.offset {
|
||||
return fmt.Errorf("invalid target offset (%d < %d): %w", off, p.offset, errMalformed)
|
||||
}
|
||||
|
||||
// Ensure we don't go beyond our maximum, if given
|
||||
if max >= 0 && off >= max {
|
||||
return fmt.Errorf("invalid target offset (%d >= %d): %w", off, max, errMalformed)
|
||||
}
|
||||
|
||||
// If we aren't already at this offset, move forward
|
||||
if p.offset < off {
|
||||
if p.checkExtraBytes {
|
||||
extraData := p.buf[p.offset:off]
|
||||
diff := off - p.offset
|
||||
p.logf("%d bytes (%d, %d) are unused: %s", diff, p.offset, off, hex.EncodeToString(extraData))
|
||||
}
|
||||
|
||||
p.offset = off
|
||||
}
|
||||
return nil
|
||||
}
|
||||
|
||||
var (
|
||||
errBufferTooSmall = errors.New("buffer too small")
|
||||
errMalformed = errors.New("data malformed")
|
||||
)
|
||||
|
||||
type entry struct {
|
||||
Offset int
|
||||
IP iptip
|
||||
NFCache uint32
|
||||
PacketCount uint64
|
||||
ByteCount uint64
|
||||
Matches []match
|
||||
Target target
|
||||
}
|
||||
|
||||
func (e entry) String() string {
|
||||
var sb strings.Builder
|
||||
sb.WriteString("{")
|
||||
|
||||
fmt.Fprintf(&sb, "Offset:%d IP:%v PacketCount:%d ByteCount:%d", e.Offset, e.IP, e.PacketCount, e.ByteCount)
|
||||
if len(e.Matches) > 0 {
|
||||
fmt.Fprintf(&sb, " Matches:%v", e.Matches)
|
||||
}
|
||||
fmt.Fprintf(&sb, " Target:%v", e.Target)
|
||||
|
||||
sb.WriteString("}")
|
||||
return sb.String()
|
||||
}
|
||||
|
||||
func (p *entryParser) parseEntry(b []byte) (entry, error) {
|
||||
startOff := p.offset
|
||||
|
||||
iptip, err := p.parseIPTIP()
|
||||
if err != nil {
|
||||
return entry{}, fmt.Errorf("parsing IPTIP: %w", err)
|
||||
}
|
||||
|
||||
ret := entry{
|
||||
Offset: startOff,
|
||||
IP: iptip,
|
||||
}
|
||||
|
||||
// Must have space for the rest of the members
|
||||
if err := p.assertLen(28); err != nil {
|
||||
return entry{}, err
|
||||
}
|
||||
|
||||
ret.NFCache = native.Endian.Uint32(p.getBytes(4))
|
||||
targetOffset := int(native.Endian.Uint16(p.getBytes(2)))
|
||||
nextOffset := int(native.Endian.Uint16(p.getBytes(2)))
|
||||
/* unused field: Comeback = */ p.getBytes(4)
|
||||
ret.PacketCount = native.Endian.Uint64(p.getBytes(8))
|
||||
ret.ByteCount = native.Endian.Uint64(p.getBytes(8))
|
||||
|
||||
// Must have at least enough space in our buffer to get to the target;
|
||||
// doing this here means we can avoid bounds checks in parseMatches
|
||||
if err := p.assertLen(targetOffset - p.offset); err != nil {
|
||||
return entry{}, err
|
||||
}
|
||||
|
||||
// Matches are stored between the end of the entry structure and the
|
||||
// start of the 'targets' structure.
|
||||
ret.Matches, err = p.parseMatches(targetOffset)
|
||||
if err != nil {
|
||||
return entry{}, err
|
||||
}
|
||||
|
||||
if targetOffset > 0 {
|
||||
if err := p.setOffset(targetOffset, nextOffset); err != nil {
|
||||
return entry{}, err
|
||||
}
|
||||
|
||||
ret.Target, err = p.parseTarget(nextOffset)
|
||||
if err != nil {
|
||||
return entry{}, fmt.Errorf("parsing target: %w", err)
|
||||
}
|
||||
}
|
||||
|
||||
if err := p.setOffset(nextOffset, -1); err != nil {
|
||||
return entry{}, err
|
||||
}
|
||||
|
||||
return ret, nil
|
||||
}
|
||||
|
||||
type iptip struct {
|
||||
Src netip.Addr
|
||||
Dst netip.Addr
|
||||
SrcMask netip.Addr
|
||||
DstMask netip.Addr
|
||||
InputInterface string
|
||||
OutputInterface string
|
||||
InputInterfaceMask []byte
|
||||
OutputInterfaceMask []byte
|
||||
Protocol uint16
|
||||
Flags uint8
|
||||
InverseFlags uint8
|
||||
}
|
||||
|
||||
var protocolNames = map[uint16]string{
|
||||
unix.IPPROTO_ESP: "esp",
|
||||
unix.IPPROTO_GRE: "gre",
|
||||
unix.IPPROTO_ICMP: "icmp",
|
||||
unix.IPPROTO_ICMPV6: "icmpv6",
|
||||
unix.IPPROTO_IGMP: "igmp",
|
||||
unix.IPPROTO_IP: "ip",
|
||||
unix.IPPROTO_IPIP: "ipip",
|
||||
unix.IPPROTO_IPV6: "ip6",
|
||||
unix.IPPROTO_RAW: "raw",
|
||||
unix.IPPROTO_TCP: "tcp",
|
||||
unix.IPPROTO_UDP: "udp",
|
||||
}
|
||||
|
||||
func (ip iptip) String() string {
|
||||
var sb strings.Builder
|
||||
sb.WriteString("{")
|
||||
|
||||
formatAddrMask := func(addr, mask netip.Addr) string {
|
||||
if pref, ok := netaddr.FromStdIPNet(&net.IPNet{
|
||||
IP: addr.AsSlice(),
|
||||
Mask: mask.AsSlice(),
|
||||
}); ok {
|
||||
return fmt.Sprint(pref)
|
||||
}
|
||||
return fmt.Sprintf("%s/%s", addr, mask)
|
||||
}
|
||||
|
||||
fmt.Fprintf(&sb, "Src:%s", formatAddrMask(ip.Src, ip.SrcMask))
|
||||
fmt.Fprintf(&sb, ", Dst:%s", formatAddrMask(ip.Dst, ip.DstMask))
|
||||
|
||||
translateMask := func(mask []byte) string {
|
||||
var ret []byte
|
||||
for _, b := range mask {
|
||||
if b != 0 {
|
||||
ret = append(ret, 'X')
|
||||
} else {
|
||||
ret = append(ret, '.')
|
||||
}
|
||||
}
|
||||
return string(ret)
|
||||
}
|
||||
|
||||
if ip.InputInterface != "" {
|
||||
fmt.Fprintf(&sb, ", InputInterface:%s/%s", ip.InputInterface, translateMask(ip.InputInterfaceMask))
|
||||
}
|
||||
if ip.OutputInterface != "" {
|
||||
fmt.Fprintf(&sb, ", OutputInterface:%s/%s", ip.OutputInterface, translateMask(ip.OutputInterfaceMask))
|
||||
}
|
||||
if nm, ok := protocolNames[ip.Protocol]; ok {
|
||||
fmt.Fprintf(&sb, ", Protocol:%s", nm)
|
||||
} else {
|
||||
fmt.Fprintf(&sb, ", Protocol:%d", ip.Protocol)
|
||||
}
|
||||
|
||||
if ip.Flags != 0 {
|
||||
fmt.Fprintf(&sb, ", Flags:%d", ip.Flags)
|
||||
}
|
||||
if ip.InverseFlags != 0 {
|
||||
fmt.Fprintf(&sb, ", InverseFlags:%d", ip.InverseFlags)
|
||||
}
|
||||
|
||||
sb.WriteString("}")
|
||||
return sb.String()
|
||||
}
|
||||
|
||||
func (p *entryParser) parseIPTIP() (iptip, error) {
|
||||
if err := p.assertLen(84); err != nil {
|
||||
return iptip{}, err
|
||||
}
|
||||
|
||||
var ret iptip
|
||||
|
||||
ret.Src = netip.AddrFrom4(p.get4())
|
||||
ret.Dst = netip.AddrFrom4(p.get4())
|
||||
ret.SrcMask = netip.AddrFrom4(p.get4())
|
||||
ret.DstMask = netip.AddrFrom4(p.get4())
|
||||
|
||||
const IFNAMSIZ = 16
|
||||
ret.InputInterface = unix.ByteSliceToString(p.getBytes(IFNAMSIZ))
|
||||
ret.OutputInterface = unix.ByteSliceToString(p.getBytes(IFNAMSIZ))
|
||||
|
||||
ret.InputInterfaceMask = p.getBytes(IFNAMSIZ)
|
||||
ret.OutputInterfaceMask = p.getBytes(IFNAMSIZ)
|
||||
|
||||
ret.Protocol = native.Endian.Uint16(p.getBytes(2))
|
||||
ret.Flags = p.getByte()
|
||||
ret.InverseFlags = p.getByte()
|
||||
return ret, nil
|
||||
}
|
||||
|
||||
type match struct {
|
||||
Name string
|
||||
Revision int
|
||||
Data any
|
||||
RawData []byte
|
||||
}
|
||||
|
||||
func (m match) String() string {
|
||||
return fmt.Sprintf("{Name:%s, Data:%v}", m.Name, m.Data)
|
||||
}
|
||||
|
||||
type matchTCP struct {
|
||||
SourcePortRange [2]uint16
|
||||
DestPortRange [2]uint16
|
||||
Option byte
|
||||
FlagMask byte
|
||||
FlagCompare byte
|
||||
InverseFlags byte
|
||||
}
|
||||
|
||||
func (m matchTCP) String() string {
|
||||
var sb strings.Builder
|
||||
sb.WriteString("{")
|
||||
|
||||
fmt.Fprintf(&sb, "SrcPort:%s, DstPort:%s",
|
||||
formatPortRange(m.SourcePortRange),
|
||||
formatPortRange(m.DestPortRange))
|
||||
|
||||
// TODO(andrew): format semantically
|
||||
if m.Option != 0 {
|
||||
fmt.Fprintf(&sb, ", Option:%d", m.Option)
|
||||
}
|
||||
if m.FlagMask != 0 {
|
||||
fmt.Fprintf(&sb, ", FlagMask:%d", m.FlagMask)
|
||||
}
|
||||
if m.FlagCompare != 0 {
|
||||
fmt.Fprintf(&sb, ", FlagCompare:%d", m.FlagCompare)
|
||||
}
|
||||
if m.InverseFlags != 0 {
|
||||
fmt.Fprintf(&sb, ", InverseFlags:%d", m.InverseFlags)
|
||||
}
|
||||
|
||||
sb.WriteString("}")
|
||||
return sb.String()
|
||||
}
|
||||
|
||||
func (p *entryParser) parseMatches(maxOffset int) ([]match, error) {
|
||||
const XT_EXTENSION_MAXNAMELEN = 29
|
||||
const structSize = 2 + XT_EXTENSION_MAXNAMELEN + 1
|
||||
|
||||
var ret []match
|
||||
for {
|
||||
// If we don't have space for a single match structure, we're done
|
||||
if p.offset+structSize > maxOffset {
|
||||
break
|
||||
}
|
||||
|
||||
var curr match
|
||||
|
||||
matchSize := int(native.Endian.Uint16(p.getBytes(2)))
|
||||
curr.Name = unix.ByteSliceToString(p.getBytes(XT_EXTENSION_MAXNAMELEN))
|
||||
curr.Revision = int(p.getByte())
|
||||
|
||||
// The data size is the total match size minus what we've already consumed.
|
||||
dataLen := matchSize - structSize
|
||||
dataEnd := p.offset + dataLen
|
||||
|
||||
// If we don't have space for the match data, then there's something wrong
|
||||
if dataEnd > maxOffset {
|
||||
return nil, fmt.Errorf("out of space for match (%d > max %d): %w", dataEnd, maxOffset, errMalformed)
|
||||
} else if dataEnd > len(p.buf) {
|
||||
return nil, fmt.Errorf("out of space for match (%d > buf %d): %w", dataEnd, len(p.buf), errMalformed)
|
||||
}
|
||||
|
||||
curr.RawData = p.getBytes(dataLen)
|
||||
|
||||
// TODO(andrew): more here; UDP, etc.
|
||||
switch curr.Name {
|
||||
case "tcp":
|
||||
/*
|
||||
struct xt_tcp {
|
||||
__u16 spts[2]; // Source port range.
|
||||
__u16 dpts[2]; // Destination port range.
|
||||
__u8 option; // TCP Option iff non-zero
|
||||
__u8 flg_mask; // TCP flags mask byte
|
||||
__u8 flg_cmp; // TCP flags compare byte
|
||||
__u8 invflags; // Inverse flags
|
||||
};
|
||||
*/
|
||||
if len(curr.RawData) >= 12 {
|
||||
curr.Data = matchTCP{
|
||||
SourcePortRange: [...]uint16{
|
||||
native.Endian.Uint16(curr.RawData[0:2]),
|
||||
native.Endian.Uint16(curr.RawData[2:4]),
|
||||
},
|
||||
DestPortRange: [...]uint16{
|
||||
native.Endian.Uint16(curr.RawData[4:6]),
|
||||
native.Endian.Uint16(curr.RawData[6:8]),
|
||||
},
|
||||
Option: curr.RawData[8],
|
||||
FlagMask: curr.RawData[9],
|
||||
FlagCompare: curr.RawData[10],
|
||||
InverseFlags: curr.RawData[11],
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
ret = append(ret, curr)
|
||||
}
|
||||
return ret, nil
|
||||
}
|
||||
|
||||
type target struct {
|
||||
Name string
|
||||
Revision int
|
||||
Data any
|
||||
RawData []byte
|
||||
}
|
||||
|
||||
func (t target) String() string {
|
||||
return fmt.Sprintf("{Name:%s, Data:%v}", t.Name, t.Data)
|
||||
}
|
||||
|
||||
func (p *entryParser) parseTarget(nextOffset int) (target, error) {
|
||||
const XT_EXTENSION_MAXNAMELEN = 29
|
||||
const structSize = 2 + XT_EXTENSION_MAXNAMELEN + 1
|
||||
|
||||
if err := p.assertLen(structSize); err != nil {
|
||||
return target{}, err
|
||||
}
|
||||
|
||||
var ret target
|
||||
|
||||
targetSize := int(native.Endian.Uint16(p.getBytes(2)))
|
||||
ret.Name = unix.ByteSliceToString(p.getBytes(XT_EXTENSION_MAXNAMELEN))
|
||||
ret.Revision = int(p.getByte())
|
||||
|
||||
if targetSize > structSize {
|
||||
dataLen := targetSize - structSize
|
||||
if err := p.assertLen(dataLen); err != nil {
|
||||
return target{}, err
|
||||
}
|
||||
|
||||
ret.RawData = p.getBytes(dataLen)
|
||||
}
|
||||
|
||||
// Special case; matches what iptables does
|
||||
if ret.Name == "" {
|
||||
ret.Name = "standard"
|
||||
}
|
||||
|
||||
switch ret.Name {
|
||||
case "standard":
|
||||
if len(ret.RawData) >= 4 {
|
||||
verdict := int32(native.Endian.Uint32(ret.RawData))
|
||||
|
||||
var info string
|
||||
switch verdict {
|
||||
case -1:
|
||||
info = "DROP"
|
||||
case -2:
|
||||
info = "ACCEPT"
|
||||
case -4:
|
||||
info = "QUEUE"
|
||||
case -5:
|
||||
info = "RETURN"
|
||||
case int32(nextOffset):
|
||||
info = "FALLTHROUGH"
|
||||
default:
|
||||
info = fmt.Sprintf("JUMP(%d)", verdict)
|
||||
}
|
||||
ret.Data = standardTarget{Verdict: info}
|
||||
}
|
||||
|
||||
case "ERROR":
|
||||
ret.Data = errorTarget{
|
||||
ErrorName: unix.ByteSliceToString(ret.RawData),
|
||||
}
|
||||
|
||||
case "REJECT":
|
||||
if len(ret.RawData) >= 4 {
|
||||
ret.Data = rejectTarget{
|
||||
With: rejectWith(native.Endian.Uint32(ret.RawData)),
|
||||
}
|
||||
}
|
||||
|
||||
case "MARK":
|
||||
if len(ret.RawData) >= 8 {
|
||||
mark := native.Endian.Uint32(ret.RawData[0:4])
|
||||
mask := native.Endian.Uint32(ret.RawData[4:8])
|
||||
|
||||
var mode markMode
|
||||
switch {
|
||||
case mark == 0:
|
||||
mode = markModeAnd
|
||||
mark = ^mask
|
||||
|
||||
case mark == mask:
|
||||
mode = markModeOr
|
||||
|
||||
case mask == 0:
|
||||
mode = markModeXor
|
||||
|
||||
case mask == 0xffffffff:
|
||||
mode = markModeSet
|
||||
|
||||
default:
|
||||
// TODO(andrew): handle xset?
|
||||
}
|
||||
|
||||
ret.Data = markTarget{
|
||||
Mark: mark,
|
||||
Mode: mode,
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
return ret, nil
|
||||
}
|
||||
|
||||
// Various types for things in iptables-land follow.
|
||||
|
||||
type standardTarget struct {
|
||||
Verdict string
|
||||
}
|
||||
|
||||
type errorTarget struct {
|
||||
ErrorName string
|
||||
}
|
||||
|
||||
type rejectWith int
|
||||
|
||||
const (
|
||||
rwIPT_ICMP_NET_UNREACHABLE rejectWith = iota
|
||||
rwIPT_ICMP_HOST_UNREACHABLE
|
||||
rwIPT_ICMP_PROT_UNREACHABLE
|
||||
rwIPT_ICMP_PORT_UNREACHABLE
|
||||
rwIPT_ICMP_ECHOREPLY
|
||||
rwIPT_ICMP_NET_PROHIBITED
|
||||
rwIPT_ICMP_HOST_PROHIBITED
|
||||
rwIPT_TCP_RESET
|
||||
rwIPT_ICMP_ADMIN_PROHIBITED
|
||||
)
|
||||
|
||||
func (rw rejectWith) String() string {
|
||||
switch rw {
|
||||
case rwIPT_ICMP_NET_UNREACHABLE:
|
||||
return "icmp-net-unreachable"
|
||||
case rwIPT_ICMP_HOST_UNREACHABLE:
|
||||
return "icmp-host-unreachable"
|
||||
case rwIPT_ICMP_PROT_UNREACHABLE:
|
||||
return "icmp-prot-unreachable"
|
||||
case rwIPT_ICMP_PORT_UNREACHABLE:
|
||||
return "icmp-port-unreachable"
|
||||
case rwIPT_ICMP_ECHOREPLY:
|
||||
return "icmp-echo-reply"
|
||||
case rwIPT_ICMP_NET_PROHIBITED:
|
||||
return "icmp-net-prohibited"
|
||||
case rwIPT_ICMP_HOST_PROHIBITED:
|
||||
return "icmp-host-prohibited"
|
||||
case rwIPT_TCP_RESET:
|
||||
return "tcp-reset"
|
||||
case rwIPT_ICMP_ADMIN_PROHIBITED:
|
||||
return "icmp-admin-prohibited"
|
||||
default:
|
||||
return "UNKNOWN"
|
||||
}
|
||||
}
|
||||
|
||||
type rejectTarget struct {
|
||||
With rejectWith
|
||||
}
|
||||
|
||||
type markMode byte
|
||||
|
||||
const (
|
||||
markModeSet markMode = iota
|
||||
markModeAnd
|
||||
markModeOr
|
||||
markModeXor
|
||||
)
|
||||
|
||||
func (mm markMode) String() string {
|
||||
switch mm {
|
||||
case markModeSet:
|
||||
return "set"
|
||||
case markModeAnd:
|
||||
return "and"
|
||||
case markModeOr:
|
||||
return "or"
|
||||
case markModeXor:
|
||||
return "xor"
|
||||
default:
|
||||
return "UNKNOWN"
|
||||
}
|
||||
}
|
||||
|
||||
type markTarget struct {
|
||||
Mode markMode
|
||||
Mark uint32
|
||||
panic("unused")
|
||||
}
|
||||
|
||||
@ -1,20 +0,0 @@
|
||||
// Copyright (c) Tailscale Inc & AUTHORS
|
||||
// SPDX-License-Identifier: BSD-3-Clause
|
||||
|
||||
// TODO(#8502): add support for more architectures
|
||||
//go:build linux && (arm64 || amd64)
|
||||
|
||||
package linuxfw
|
||||
|
||||
import (
|
||||
"testing"
|
||||
"unsafe"
|
||||
|
||||
"tailscale.com/util/linuxfw/linuxfwtest"
|
||||
)
|
||||
|
||||
func TestSizes(t *testing.T) {
|
||||
linuxfwtest.TestSizes(t, &linuxfwtest.SizeInfo{
|
||||
SizeofSocklen: unsafe.Sizeof(sockLen(0)),
|
||||
})
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user