tailscale/net/packet/packet.go

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// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package packet
import (
"encoding/binary"
"fmt"
net/packet: remove the custom IP4/IP6 types in favor of netaddr.IP. Upstream netaddr has a change that makes it alloc-free, so it's safe to use in hot codepaths. This gets rid of one of the many IP types in our codebase. Performance is currently worse across the board. This is likely due in part to netaddr.IP being a larger value type (4b -> 24b for IPv4, 16b -> 24b for IPv6), and in other part due to missing low-hanging fruit optimizations in netaddr. However, the regression is less bad than it looks at first glance, because we'd micro-optimized packet.IP* in the past few weeks. This change drops us back to roughly where we were at the 1.2 release, but with the benefit of a significant code and architectural simplification. name old time/op new time/op delta pkg:tailscale.com/net/packet goos:linux goarch:amd64 Decode/tcp4-8 12.2ns ± 5% 29.7ns ± 2% +142.32% (p=0.008 n=5+5) Decode/tcp6-8 12.6ns ± 3% 65.1ns ± 2% +418.47% (p=0.008 n=5+5) Decode/udp4-8 11.8ns ± 3% 30.5ns ± 2% +157.94% (p=0.008 n=5+5) Decode/udp6-8 27.1ns ± 1% 65.7ns ± 2% +142.36% (p=0.016 n=4+5) Decode/icmp4-8 24.6ns ± 2% 30.5ns ± 2% +23.65% (p=0.016 n=4+5) Decode/icmp6-8 22.9ns ±51% 65.5ns ± 2% +186.19% (p=0.008 n=5+5) Decode/igmp-8 18.1ns ±44% 30.2ns ± 1% +66.89% (p=0.008 n=5+5) Decode/unknown-8 20.8ns ± 1% 10.6ns ± 9% -49.11% (p=0.016 n=4+5) pkg:tailscale.com/wgengine/filter goos:linux goarch:amd64 Filter/icmp4-8 30.5ns ± 1% 77.9ns ± 3% +155.01% (p=0.008 n=5+5) Filter/tcp4_syn_in-8 43.7ns ± 3% 123.0ns ± 3% +181.72% (p=0.008 n=5+5) Filter/tcp4_syn_out-8 24.5ns ± 2% 45.7ns ± 6% +86.22% (p=0.008 n=5+5) Filter/udp4_in-8 64.8ns ± 1% 210.0ns ± 2% +223.87% (p=0.008 n=5+5) Filter/udp4_out-8 119ns ± 0% 278ns ± 0% +133.78% (p=0.016 n=4+5) Filter/icmp6-8 40.3ns ± 2% 204.4ns ± 4% +407.70% (p=0.008 n=5+5) Filter/tcp6_syn_in-8 35.3ns ± 3% 199.2ns ± 2% +464.95% (p=0.008 n=5+5) Filter/tcp6_syn_out-8 32.8ns ± 2% 81.0ns ± 2% +147.10% (p=0.008 n=5+5) Filter/udp6_in-8 106ns ± 2% 290ns ± 2% +174.48% (p=0.008 n=5+5) Filter/udp6_out-8 184ns ± 2% 314ns ± 3% +70.43% (p=0.016 n=4+5) pkg:tailscale.com/wgengine/tstun goos:linux goarch:amd64 Write-8 9.02ns ± 3% 8.92ns ± 1% ~ (p=0.421 n=5+5) name old alloc/op new alloc/op delta pkg:tailscale.com/net/packet goos:linux goarch:amd64 Decode/tcp4-8 0.00B 0.00B ~ (all equal) Decode/tcp6-8 0.00B 0.00B ~ (all equal) Decode/udp4-8 0.00B 0.00B ~ (all equal) Decode/udp6-8 0.00B 0.00B ~ (all equal) Decode/icmp4-8 0.00B 0.00B ~ (all equal) Decode/icmp6-8 0.00B 0.00B ~ (all equal) Decode/igmp-8 0.00B 0.00B ~ (all equal) Decode/unknown-8 0.00B 0.00B ~ (all equal) pkg:tailscale.com/wgengine/filter goos:linux goarch:amd64 Filter/icmp4-8 0.00B 0.00B ~ (all equal) Filter/tcp4_syn_in-8 0.00B 0.00B ~ (all equal) Filter/tcp4_syn_out-8 0.00B 0.00B ~ (all equal) Filter/udp4_in-8 0.00B 0.00B ~ (all equal) Filter/udp4_out-8 16.0B ± 0% 64.0B ± 0% +300.00% (p=0.008 n=5+5) Filter/icmp6-8 0.00B 0.00B ~ (all equal) Filter/tcp6_syn_in-8 0.00B 0.00B ~ (all equal) Filter/tcp6_syn_out-8 0.00B 0.00B ~ (all equal) Filter/udp6_in-8 0.00B 0.00B ~ (all equal) Filter/udp6_out-8 48.0B ± 0% 64.0B ± 0% +33.33% (p=0.008 n=5+5) name old allocs/op new allocs/op delta pkg:tailscale.com/net/packet goos:linux goarch:amd64 Decode/tcp4-8 0.00 0.00 ~ (all equal) Decode/tcp6-8 0.00 0.00 ~ (all equal) Decode/udp4-8 0.00 0.00 ~ (all equal) Decode/udp6-8 0.00 0.00 ~ (all equal) Decode/icmp4-8 0.00 0.00 ~ (all equal) Decode/icmp6-8 0.00 0.00 ~ (all equal) Decode/igmp-8 0.00 0.00 ~ (all equal) Decode/unknown-8 0.00 0.00 ~ (all equal) pkg:tailscale.com/wgengine/filter goos:linux goarch:amd64 Filter/icmp4-8 0.00 0.00 ~ (all equal) Filter/tcp4_syn_in-8 0.00 0.00 ~ (all equal) Filter/tcp4_syn_out-8 0.00 0.00 ~ (all equal) Filter/udp4_in-8 0.00 0.00 ~ (all equal) Filter/udp4_out-8 1.00 ± 0% 1.00 ± 0% ~ (all equal) Filter/icmp6-8 0.00 0.00 ~ (all equal) Filter/tcp6_syn_in-8 0.00 0.00 ~ (all equal) Filter/tcp6_syn_out-8 0.00 0.00 ~ (all equal) Filter/udp6_in-8 0.00 0.00 ~ (all equal) Filter/udp6_out-8 1.00 ± 0% 1.00 ± 0% ~ (all equal) Signed-off-by: David Anderson <danderson@tailscale.com>
2020-12-20 00:43:25 +00:00
"net"
"strings"
net/packet: remove the custom IP4/IP6 types in favor of netaddr.IP. Upstream netaddr has a change that makes it alloc-free, so it's safe to use in hot codepaths. This gets rid of one of the many IP types in our codebase. Performance is currently worse across the board. This is likely due in part to netaddr.IP being a larger value type (4b -> 24b for IPv4, 16b -> 24b for IPv6), and in other part due to missing low-hanging fruit optimizations in netaddr. However, the regression is less bad than it looks at first glance, because we'd micro-optimized packet.IP* in the past few weeks. This change drops us back to roughly where we were at the 1.2 release, but with the benefit of a significant code and architectural simplification. name old time/op new time/op delta pkg:tailscale.com/net/packet goos:linux goarch:amd64 Decode/tcp4-8 12.2ns ± 5% 29.7ns ± 2% +142.32% (p=0.008 n=5+5) Decode/tcp6-8 12.6ns ± 3% 65.1ns ± 2% +418.47% (p=0.008 n=5+5) Decode/udp4-8 11.8ns ± 3% 30.5ns ± 2% +157.94% (p=0.008 n=5+5) Decode/udp6-8 27.1ns ± 1% 65.7ns ± 2% +142.36% (p=0.016 n=4+5) Decode/icmp4-8 24.6ns ± 2% 30.5ns ± 2% +23.65% (p=0.016 n=4+5) Decode/icmp6-8 22.9ns ±51% 65.5ns ± 2% +186.19% (p=0.008 n=5+5) Decode/igmp-8 18.1ns ±44% 30.2ns ± 1% +66.89% (p=0.008 n=5+5) Decode/unknown-8 20.8ns ± 1% 10.6ns ± 9% -49.11% (p=0.016 n=4+5) pkg:tailscale.com/wgengine/filter goos:linux goarch:amd64 Filter/icmp4-8 30.5ns ± 1% 77.9ns ± 3% +155.01% (p=0.008 n=5+5) Filter/tcp4_syn_in-8 43.7ns ± 3% 123.0ns ± 3% +181.72% (p=0.008 n=5+5) Filter/tcp4_syn_out-8 24.5ns ± 2% 45.7ns ± 6% +86.22% (p=0.008 n=5+5) Filter/udp4_in-8 64.8ns ± 1% 210.0ns ± 2% +223.87% (p=0.008 n=5+5) Filter/udp4_out-8 119ns ± 0% 278ns ± 0% +133.78% (p=0.016 n=4+5) Filter/icmp6-8 40.3ns ± 2% 204.4ns ± 4% +407.70% (p=0.008 n=5+5) Filter/tcp6_syn_in-8 35.3ns ± 3% 199.2ns ± 2% +464.95% (p=0.008 n=5+5) Filter/tcp6_syn_out-8 32.8ns ± 2% 81.0ns ± 2% +147.10% (p=0.008 n=5+5) Filter/udp6_in-8 106ns ± 2% 290ns ± 2% +174.48% (p=0.008 n=5+5) Filter/udp6_out-8 184ns ± 2% 314ns ± 3% +70.43% (p=0.016 n=4+5) pkg:tailscale.com/wgengine/tstun goos:linux goarch:amd64 Write-8 9.02ns ± 3% 8.92ns ± 1% ~ (p=0.421 n=5+5) name old alloc/op new alloc/op delta pkg:tailscale.com/net/packet goos:linux goarch:amd64 Decode/tcp4-8 0.00B 0.00B ~ (all equal) Decode/tcp6-8 0.00B 0.00B ~ (all equal) Decode/udp4-8 0.00B 0.00B ~ (all equal) Decode/udp6-8 0.00B 0.00B ~ (all equal) Decode/icmp4-8 0.00B 0.00B ~ (all equal) Decode/icmp6-8 0.00B 0.00B ~ (all equal) Decode/igmp-8 0.00B 0.00B ~ (all equal) Decode/unknown-8 0.00B 0.00B ~ (all equal) pkg:tailscale.com/wgengine/filter goos:linux goarch:amd64 Filter/icmp4-8 0.00B 0.00B ~ (all equal) Filter/tcp4_syn_in-8 0.00B 0.00B ~ (all equal) Filter/tcp4_syn_out-8 0.00B 0.00B ~ (all equal) Filter/udp4_in-8 0.00B 0.00B ~ (all equal) Filter/udp4_out-8 16.0B ± 0% 64.0B ± 0% +300.00% (p=0.008 n=5+5) Filter/icmp6-8 0.00B 0.00B ~ (all equal) Filter/tcp6_syn_in-8 0.00B 0.00B ~ (all equal) Filter/tcp6_syn_out-8 0.00B 0.00B ~ (all equal) Filter/udp6_in-8 0.00B 0.00B ~ (all equal) Filter/udp6_out-8 48.0B ± 0% 64.0B ± 0% +33.33% (p=0.008 n=5+5) name old allocs/op new allocs/op delta pkg:tailscale.com/net/packet goos:linux goarch:amd64 Decode/tcp4-8 0.00 0.00 ~ (all equal) Decode/tcp6-8 0.00 0.00 ~ (all equal) Decode/udp4-8 0.00 0.00 ~ (all equal) Decode/udp6-8 0.00 0.00 ~ (all equal) Decode/icmp4-8 0.00 0.00 ~ (all equal) Decode/icmp6-8 0.00 0.00 ~ (all equal) Decode/igmp-8 0.00 0.00 ~ (all equal) Decode/unknown-8 0.00 0.00 ~ (all equal) pkg:tailscale.com/wgengine/filter goos:linux goarch:amd64 Filter/icmp4-8 0.00 0.00 ~ (all equal) Filter/tcp4_syn_in-8 0.00 0.00 ~ (all equal) Filter/tcp4_syn_out-8 0.00 0.00 ~ (all equal) Filter/udp4_in-8 0.00 0.00 ~ (all equal) Filter/udp4_out-8 1.00 ± 0% 1.00 ± 0% ~ (all equal) Filter/icmp6-8 0.00 0.00 ~ (all equal) Filter/tcp6_syn_in-8 0.00 0.00 ~ (all equal) Filter/tcp6_syn_out-8 0.00 0.00 ~ (all equal) Filter/udp6_in-8 0.00 0.00 ~ (all equal) Filter/udp6_out-8 1.00 ± 0% 1.00 ± 0% ~ (all equal) Signed-off-by: David Anderson <danderson@tailscale.com>
2020-12-20 00:43:25 +00:00
"inet.af/netaddr"
"tailscale.com/types/ipproto"
)
const unknown = ipproto.Unknown
// RFC1858: prevent overlapping fragment attacks.
const minFrag = 60 + 20 // max IPv4 header + basic TCP header
type TCPFlag uint8
const (
TCPFin TCPFlag = 0x01
TCPSyn TCPFlag = 0x02
TCPRst TCPFlag = 0x04
TCPPsh TCPFlag = 0x08
TCPAck TCPFlag = 0x10
TCPSynAck TCPFlag = TCPSyn | TCPAck
)
// Parsed is a minimal decoding of a packet suitable for use in filters.
type Parsed struct {
// b is the byte buffer that this decodes.
b []byte
// subofs is the offset of IP subprotocol.
subofs int
// dataofs is the offset of IP subprotocol payload.
dataofs int
// length is the total length of the packet.
// This is not the same as len(b) because b can have trailing zeros.
length int
// IPVersion is the IP protocol version of the packet (4 or
// 6), or 0 if the packet doesn't look like IPv4 or IPv6.
IPVersion uint8
// IPProto is the IP subprotocol (UDP, TCP, etc.). Valid iff IPVersion != 0.
IPProto ipproto.Proto
net/packet: remove the custom IP4/IP6 types in favor of netaddr.IP. Upstream netaddr has a change that makes it alloc-free, so it's safe to use in hot codepaths. This gets rid of one of the many IP types in our codebase. Performance is currently worse across the board. This is likely due in part to netaddr.IP being a larger value type (4b -> 24b for IPv4, 16b -> 24b for IPv6), and in other part due to missing low-hanging fruit optimizations in netaddr. However, the regression is less bad than it looks at first glance, because we'd micro-optimized packet.IP* in the past few weeks. This change drops us back to roughly where we were at the 1.2 release, but with the benefit of a significant code and architectural simplification. name old time/op new time/op delta pkg:tailscale.com/net/packet goos:linux goarch:amd64 Decode/tcp4-8 12.2ns ± 5% 29.7ns ± 2% +142.32% (p=0.008 n=5+5) Decode/tcp6-8 12.6ns ± 3% 65.1ns ± 2% +418.47% (p=0.008 n=5+5) Decode/udp4-8 11.8ns ± 3% 30.5ns ± 2% +157.94% (p=0.008 n=5+5) Decode/udp6-8 27.1ns ± 1% 65.7ns ± 2% +142.36% (p=0.016 n=4+5) Decode/icmp4-8 24.6ns ± 2% 30.5ns ± 2% +23.65% (p=0.016 n=4+5) Decode/icmp6-8 22.9ns ±51% 65.5ns ± 2% +186.19% (p=0.008 n=5+5) Decode/igmp-8 18.1ns ±44% 30.2ns ± 1% +66.89% (p=0.008 n=5+5) Decode/unknown-8 20.8ns ± 1% 10.6ns ± 9% -49.11% (p=0.016 n=4+5) pkg:tailscale.com/wgengine/filter goos:linux goarch:amd64 Filter/icmp4-8 30.5ns ± 1% 77.9ns ± 3% +155.01% (p=0.008 n=5+5) Filter/tcp4_syn_in-8 43.7ns ± 3% 123.0ns ± 3% +181.72% (p=0.008 n=5+5) Filter/tcp4_syn_out-8 24.5ns ± 2% 45.7ns ± 6% +86.22% (p=0.008 n=5+5) Filter/udp4_in-8 64.8ns ± 1% 210.0ns ± 2% +223.87% (p=0.008 n=5+5) Filter/udp4_out-8 119ns ± 0% 278ns ± 0% +133.78% (p=0.016 n=4+5) Filter/icmp6-8 40.3ns ± 2% 204.4ns ± 4% +407.70% (p=0.008 n=5+5) Filter/tcp6_syn_in-8 35.3ns ± 3% 199.2ns ± 2% +464.95% (p=0.008 n=5+5) Filter/tcp6_syn_out-8 32.8ns ± 2% 81.0ns ± 2% +147.10% (p=0.008 n=5+5) Filter/udp6_in-8 106ns ± 2% 290ns ± 2% +174.48% (p=0.008 n=5+5) Filter/udp6_out-8 184ns ± 2% 314ns ± 3% +70.43% (p=0.016 n=4+5) pkg:tailscale.com/wgengine/tstun goos:linux goarch:amd64 Write-8 9.02ns ± 3% 8.92ns ± 1% ~ (p=0.421 n=5+5) name old alloc/op new alloc/op delta pkg:tailscale.com/net/packet goos:linux goarch:amd64 Decode/tcp4-8 0.00B 0.00B ~ (all equal) Decode/tcp6-8 0.00B 0.00B ~ (all equal) Decode/udp4-8 0.00B 0.00B ~ (all equal) Decode/udp6-8 0.00B 0.00B ~ (all equal) Decode/icmp4-8 0.00B 0.00B ~ (all equal) Decode/icmp6-8 0.00B 0.00B ~ (all equal) Decode/igmp-8 0.00B 0.00B ~ (all equal) Decode/unknown-8 0.00B 0.00B ~ (all equal) pkg:tailscale.com/wgengine/filter goos:linux goarch:amd64 Filter/icmp4-8 0.00B 0.00B ~ (all equal) Filter/tcp4_syn_in-8 0.00B 0.00B ~ (all equal) Filter/tcp4_syn_out-8 0.00B 0.00B ~ (all equal) Filter/udp4_in-8 0.00B 0.00B ~ (all equal) Filter/udp4_out-8 16.0B ± 0% 64.0B ± 0% +300.00% (p=0.008 n=5+5) Filter/icmp6-8 0.00B 0.00B ~ (all equal) Filter/tcp6_syn_in-8 0.00B 0.00B ~ (all equal) Filter/tcp6_syn_out-8 0.00B 0.00B ~ (all equal) Filter/udp6_in-8 0.00B 0.00B ~ (all equal) Filter/udp6_out-8 48.0B ± 0% 64.0B ± 0% +33.33% (p=0.008 n=5+5) name old allocs/op new allocs/op delta pkg:tailscale.com/net/packet goos:linux goarch:amd64 Decode/tcp4-8 0.00 0.00 ~ (all equal) Decode/tcp6-8 0.00 0.00 ~ (all equal) Decode/udp4-8 0.00 0.00 ~ (all equal) Decode/udp6-8 0.00 0.00 ~ (all equal) Decode/icmp4-8 0.00 0.00 ~ (all equal) Decode/icmp6-8 0.00 0.00 ~ (all equal) Decode/igmp-8 0.00 0.00 ~ (all equal) Decode/unknown-8 0.00 0.00 ~ (all equal) pkg:tailscale.com/wgengine/filter goos:linux goarch:amd64 Filter/icmp4-8 0.00 0.00 ~ (all equal) Filter/tcp4_syn_in-8 0.00 0.00 ~ (all equal) Filter/tcp4_syn_out-8 0.00 0.00 ~ (all equal) Filter/udp4_in-8 0.00 0.00 ~ (all equal) Filter/udp4_out-8 1.00 ± 0% 1.00 ± 0% ~ (all equal) Filter/icmp6-8 0.00 0.00 ~ (all equal) Filter/tcp6_syn_in-8 0.00 0.00 ~ (all equal) Filter/tcp6_syn_out-8 0.00 0.00 ~ (all equal) Filter/udp6_in-8 0.00 0.00 ~ (all equal) Filter/udp6_out-8 1.00 ± 0% 1.00 ± 0% ~ (all equal) Signed-off-by: David Anderson <danderson@tailscale.com>
2020-12-20 00:43:25 +00:00
// SrcIP4 is the source address. Family matches IPVersion. Port is
// valid iff IPProto == TCP || IPProto == UDP.
Src netaddr.IPPort
// DstIP4 is the destination address. Family matches IPVersion.
Dst netaddr.IPPort
// TCPFlags is the packet's TCP flag bigs. Valid iff IPProto == TCP.
TCPFlags TCPFlag
}
func (p *Parsed) String() string {
net/packet: remove the custom IP4/IP6 types in favor of netaddr.IP. Upstream netaddr has a change that makes it alloc-free, so it's safe to use in hot codepaths. This gets rid of one of the many IP types in our codebase. Performance is currently worse across the board. This is likely due in part to netaddr.IP being a larger value type (4b -> 24b for IPv4, 16b -> 24b for IPv6), and in other part due to missing low-hanging fruit optimizations in netaddr. However, the regression is less bad than it looks at first glance, because we'd micro-optimized packet.IP* in the past few weeks. This change drops us back to roughly where we were at the 1.2 release, but with the benefit of a significant code and architectural simplification. name old time/op new time/op delta pkg:tailscale.com/net/packet goos:linux goarch:amd64 Decode/tcp4-8 12.2ns ± 5% 29.7ns ± 2% +142.32% (p=0.008 n=5+5) Decode/tcp6-8 12.6ns ± 3% 65.1ns ± 2% +418.47% (p=0.008 n=5+5) Decode/udp4-8 11.8ns ± 3% 30.5ns ± 2% +157.94% (p=0.008 n=5+5) Decode/udp6-8 27.1ns ± 1% 65.7ns ± 2% +142.36% (p=0.016 n=4+5) Decode/icmp4-8 24.6ns ± 2% 30.5ns ± 2% +23.65% (p=0.016 n=4+5) Decode/icmp6-8 22.9ns ±51% 65.5ns ± 2% +186.19% (p=0.008 n=5+5) Decode/igmp-8 18.1ns ±44% 30.2ns ± 1% +66.89% (p=0.008 n=5+5) Decode/unknown-8 20.8ns ± 1% 10.6ns ± 9% -49.11% (p=0.016 n=4+5) pkg:tailscale.com/wgengine/filter goos:linux goarch:amd64 Filter/icmp4-8 30.5ns ± 1% 77.9ns ± 3% +155.01% (p=0.008 n=5+5) Filter/tcp4_syn_in-8 43.7ns ± 3% 123.0ns ± 3% +181.72% (p=0.008 n=5+5) Filter/tcp4_syn_out-8 24.5ns ± 2% 45.7ns ± 6% +86.22% (p=0.008 n=5+5) Filter/udp4_in-8 64.8ns ± 1% 210.0ns ± 2% +223.87% (p=0.008 n=5+5) Filter/udp4_out-8 119ns ± 0% 278ns ± 0% +133.78% (p=0.016 n=4+5) Filter/icmp6-8 40.3ns ± 2% 204.4ns ± 4% +407.70% (p=0.008 n=5+5) Filter/tcp6_syn_in-8 35.3ns ± 3% 199.2ns ± 2% +464.95% (p=0.008 n=5+5) Filter/tcp6_syn_out-8 32.8ns ± 2% 81.0ns ± 2% +147.10% (p=0.008 n=5+5) Filter/udp6_in-8 106ns ± 2% 290ns ± 2% +174.48% (p=0.008 n=5+5) Filter/udp6_out-8 184ns ± 2% 314ns ± 3% +70.43% (p=0.016 n=4+5) pkg:tailscale.com/wgengine/tstun goos:linux goarch:amd64 Write-8 9.02ns ± 3% 8.92ns ± 1% ~ (p=0.421 n=5+5) name old alloc/op new alloc/op delta pkg:tailscale.com/net/packet goos:linux goarch:amd64 Decode/tcp4-8 0.00B 0.00B ~ (all equal) Decode/tcp6-8 0.00B 0.00B ~ (all equal) Decode/udp4-8 0.00B 0.00B ~ (all equal) Decode/udp6-8 0.00B 0.00B ~ (all equal) Decode/icmp4-8 0.00B 0.00B ~ (all equal) Decode/icmp6-8 0.00B 0.00B ~ (all equal) Decode/igmp-8 0.00B 0.00B ~ (all equal) Decode/unknown-8 0.00B 0.00B ~ (all equal) pkg:tailscale.com/wgengine/filter goos:linux goarch:amd64 Filter/icmp4-8 0.00B 0.00B ~ (all equal) Filter/tcp4_syn_in-8 0.00B 0.00B ~ (all equal) Filter/tcp4_syn_out-8 0.00B 0.00B ~ (all equal) Filter/udp4_in-8 0.00B 0.00B ~ (all equal) Filter/udp4_out-8 16.0B ± 0% 64.0B ± 0% +300.00% (p=0.008 n=5+5) Filter/icmp6-8 0.00B 0.00B ~ (all equal) Filter/tcp6_syn_in-8 0.00B 0.00B ~ (all equal) Filter/tcp6_syn_out-8 0.00B 0.00B ~ (all equal) Filter/udp6_in-8 0.00B 0.00B ~ (all equal) Filter/udp6_out-8 48.0B ± 0% 64.0B ± 0% +33.33% (p=0.008 n=5+5) name old allocs/op new allocs/op delta pkg:tailscale.com/net/packet goos:linux goarch:amd64 Decode/tcp4-8 0.00 0.00 ~ (all equal) Decode/tcp6-8 0.00 0.00 ~ (all equal) Decode/udp4-8 0.00 0.00 ~ (all equal) Decode/udp6-8 0.00 0.00 ~ (all equal) Decode/icmp4-8 0.00 0.00 ~ (all equal) Decode/icmp6-8 0.00 0.00 ~ (all equal) Decode/igmp-8 0.00 0.00 ~ (all equal) Decode/unknown-8 0.00 0.00 ~ (all equal) pkg:tailscale.com/wgengine/filter goos:linux goarch:amd64 Filter/icmp4-8 0.00 0.00 ~ (all equal) Filter/tcp4_syn_in-8 0.00 0.00 ~ (all equal) Filter/tcp4_syn_out-8 0.00 0.00 ~ (all equal) Filter/udp4_in-8 0.00 0.00 ~ (all equal) Filter/udp4_out-8 1.00 ± 0% 1.00 ± 0% ~ (all equal) Filter/icmp6-8 0.00 0.00 ~ (all equal) Filter/tcp6_syn_in-8 0.00 0.00 ~ (all equal) Filter/tcp6_syn_out-8 0.00 0.00 ~ (all equal) Filter/udp6_in-8 0.00 0.00 ~ (all equal) Filter/udp6_out-8 1.00 ± 0% 1.00 ± 0% ~ (all equal) Signed-off-by: David Anderson <danderson@tailscale.com>
2020-12-20 00:43:25 +00:00
if p.IPVersion != 4 && p.IPVersion != 6 {
return "Unknown{???}"
}
net/packet: use netaddr AppendTo methods This lets us remote the types/strbuilder package, which had only a single user. And it's faster. name old time/op new time/op delta String/tcp4-8 175ns ± 0% 58ns ± 1% -66.95% (p=0.000 n=10+9) String/tcp6-8 226ns ± 1% 136ns ± 1% -39.85% (p=0.000 n=10+10) String/udp4-8 175ns ± 1% 58ns ± 1% -67.01% (p=0.000 n=10+9) String/udp6-8 230ns ± 1% 140ns ± 0% -39.32% (p=0.000 n=10+9) String/icmp4-8 164ns ± 0% 50ns ± 1% -69.89% (p=0.000 n=10+10) String/icmp6-8 217ns ± 1% 129ns ± 0% -40.46% (p=0.000 n=10+10) String/igmp-8 196ns ± 0% 56ns ± 1% -71.32% (p=0.000 n=10+10) String/unknown-8 2.06ns ± 1% 2.06ns ± 2% ~ (p=0.985 n=10+10) name old alloc/op new alloc/op delta String/tcp4-8 32.0B ± 0% 32.0B ± 0% ~ (all equal) String/tcp6-8 168B ± 0% 96B ± 0% -42.86% (p=0.000 n=10+10) String/udp4-8 32.0B ± 0% 32.0B ± 0% ~ (all equal) String/udp6-8 168B ± 0% 96B ± 0% -42.86% (p=0.000 n=10+10) String/icmp4-8 32.0B ± 0% 32.0B ± 0% ~ (all equal) String/icmp6-8 104B ± 0% 64B ± 0% -38.46% (p=0.000 n=10+10) String/igmp-8 48.0B ± 0% 48.0B ± 0% ~ (all equal) String/unknown-8 0.00B 0.00B ~ (all equal) name old allocs/op new allocs/op delta String/tcp4-8 1.00 ± 0% 1.00 ± 0% ~ (all equal) String/tcp6-8 3.00 ± 0% 1.00 ± 0% -66.67% (p=0.000 n=10+10) String/udp4-8 1.00 ± 0% 1.00 ± 0% ~ (all equal) String/udp6-8 3.00 ± 0% 1.00 ± 0% -66.67% (p=0.000 n=10+10) String/icmp4-8 1.00 ± 0% 1.00 ± 0% ~ (all equal) String/icmp6-8 3.00 ± 0% 1.00 ± 0% -66.67% (p=0.000 n=10+10) String/igmp-8 1.00 ± 0% 1.00 ± 0% ~ (all equal) String/unknown-8 0.00 0.00 ~ (all equal) Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
2021-05-18 19:46:30 +00:00
// max is the maximum reasonable length of the string we are constructing.
// It's OK to overshoot, as the temp buffer is allocated on the stack.
const max = len("ICMPv6{[ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff%enp5s0]:65535 > [ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff%enp5s0]:65535}")
b := make([]byte, 0, max)
b = append(b, p.IPProto.String()...)
b = append(b, '{')
b = p.Src.AppendTo(b)
b = append(b, ' ', '>', ' ')
b = p.Dst.AppendTo(b)
b = append(b, '}')
return string(b)
}
// Decode extracts data from the packet in b into q.
// It performs extremely simple packet decoding for basic IPv4 and IPv6 packet types.
// It extracts only the subprotocol id, IP addresses, and (if any) ports,
// and shouldn't need any memory allocation.
func (q *Parsed) Decode(b []byte) {
q.b = b
if len(b) < 1 {
q.IPVersion = 0
q.IPProto = unknown
return
}
q.IPVersion = b[0] >> 4
switch q.IPVersion {
case 4:
q.decode4(b)
case 6:
q.decode6(b)
default:
q.IPVersion = 0
q.IPProto = unknown
}
}
// StuffForTesting makes Parsed contain a len-bytes buffer. Used in
// tests to build up a synthetic parse result with a non-zero buffer.
func (q *Parsed) StuffForTesting(len int) {
q.b = make([]byte, len)
}
func (q *Parsed) decode4(b []byte) {
if len(b) < ip4HeaderLength {
q.IPVersion = 0
q.IPProto = unknown
return
}
// Check that it's IPv4.
q.IPProto = ipproto.Proto(b[9])
q.length = int(binary.BigEndian.Uint16(b[2:4]))
if len(b) < q.length {
// Packet was cut off before full IPv4 length.
q.IPProto = unknown
return
}
// If it's valid IPv4, then the IP addresses are valid
q.Src = q.Src.WithIP(netaddr.IPv4(b[12], b[13], b[14], b[15]))
q.Dst = q.Dst.WithIP(netaddr.IPv4(b[16], b[17], b[18], b[19]))
q.subofs = int((b[0] & 0x0F) << 2)
if q.subofs > q.length {
// next-proto starts beyond end of packet.
q.IPProto = unknown
return
}
sub := b[q.subofs:]
sub = sub[:len(sub):len(sub)] // help the compiler do bounds check elimination
// We don't care much about IP fragmentation, except insofar as it's
// used for firewall bypass attacks. The trick is make the first
// fragment of a TCP or UDP packet so short that it doesn't fit
// the TCP or UDP header, so we can't read the port, in hope that
// it'll sneak past. Then subsequent fragments fill it in, but we're
// missing the first part of the header, so we can't read that either.
//
// A "perfectly correct" implementation would have to reassemble
// fragments before deciding what to do. But the truth is there's
// zero reason to send such a short first fragment, so we can treat
// it as Unknown. We can also treat any subsequent fragment that starts
// at such a low offset as Unknown.
fragFlags := binary.BigEndian.Uint16(b[6:8])
moreFrags := (fragFlags & 0x20) != 0
fragOfs := fragFlags & 0x1FFF
if fragOfs == 0 {
// This is the first fragment
if moreFrags && len(sub) < minFrag {
// Suspiciously short first fragment, dump it.
q.IPProto = unknown
return
}
// otherwise, this is either non-fragmented (the usual case)
// or a big enough initial fragment that we can read the
// whole subprotocol header.
switch q.IPProto {
case ipproto.ICMPv4:
if len(sub) < icmp4HeaderLength {
q.IPProto = unknown
return
}
q.Src = q.Src.WithPort(0)
q.Dst = q.Dst.WithPort(0)
q.dataofs = q.subofs + icmp4HeaderLength
return
case ipproto.IGMP:
// Keep IPProto, but don't parse anything else
// out.
return
case ipproto.TCP:
if len(sub) < tcpHeaderLength {
q.IPProto = unknown
return
}
q.Src = q.Src.WithPort(binary.BigEndian.Uint16(sub[0:2]))
q.Dst = q.Dst.WithPort(binary.BigEndian.Uint16(sub[2:4]))
q.TCPFlags = TCPFlag(sub[13]) & 0x3F
headerLength := (sub[12] & 0xF0) >> 2
q.dataofs = q.subofs + int(headerLength)
return
case ipproto.UDP:
if len(sub) < udpHeaderLength {
q.IPProto = unknown
return
}
q.Src = q.Src.WithPort(binary.BigEndian.Uint16(sub[0:2]))
q.Dst = q.Dst.WithPort(binary.BigEndian.Uint16(sub[2:4]))
q.dataofs = q.subofs + udpHeaderLength
return
case ipproto.SCTP:
if len(sub) < sctpHeaderLength {
q.IPProto = unknown
return
}
q.Src = q.Src.WithPort(binary.BigEndian.Uint16(sub[0:2]))
q.Dst = q.Dst.WithPort(binary.BigEndian.Uint16(sub[2:4]))
return
case ipproto.TSMP:
// Inter-tailscale messages.
q.dataofs = q.subofs
return
default:
q.IPProto = unknown
return
}
} else {
// This is a fragment other than the first one.
if fragOfs < minFrag {
// First frag was suspiciously short, so we can't
// trust the followup either.
q.IPProto = unknown
return
}
// otherwise, we have to permit the fragment to slide through.
// Second and later fragments don't have sub-headers.
// Ideally, we would drop fragments that we can't identify,
// but that would require statefulness. Anyway, receivers'
// kernels know to drop fragments where the initial fragment
// doesn't arrive.
q.IPProto = ipproto.Fragment
return
}
}
func (q *Parsed) decode6(b []byte) {
if len(b) < ip6HeaderLength {
q.IPVersion = 0
q.IPProto = unknown
return
}
q.IPProto = ipproto.Proto(b[6])
q.length = int(binary.BigEndian.Uint16(b[4:6])) + ip6HeaderLength
if len(b) < q.length {
// Packet was cut off before the full IPv6 length.
q.IPProto = unknown
return
}
net/packet: remove the custom IP4/IP6 types in favor of netaddr.IP. Upstream netaddr has a change that makes it alloc-free, so it's safe to use in hot codepaths. This gets rid of one of the many IP types in our codebase. Performance is currently worse across the board. This is likely due in part to netaddr.IP being a larger value type (4b -> 24b for IPv4, 16b -> 24b for IPv6), and in other part due to missing low-hanging fruit optimizations in netaddr. However, the regression is less bad than it looks at first glance, because we'd micro-optimized packet.IP* in the past few weeks. This change drops us back to roughly where we were at the 1.2 release, but with the benefit of a significant code and architectural simplification. name old time/op new time/op delta pkg:tailscale.com/net/packet goos:linux goarch:amd64 Decode/tcp4-8 12.2ns ± 5% 29.7ns ± 2% +142.32% (p=0.008 n=5+5) Decode/tcp6-8 12.6ns ± 3% 65.1ns ± 2% +418.47% (p=0.008 n=5+5) Decode/udp4-8 11.8ns ± 3% 30.5ns ± 2% +157.94% (p=0.008 n=5+5) Decode/udp6-8 27.1ns ± 1% 65.7ns ± 2% +142.36% (p=0.016 n=4+5) Decode/icmp4-8 24.6ns ± 2% 30.5ns ± 2% +23.65% (p=0.016 n=4+5) Decode/icmp6-8 22.9ns ±51% 65.5ns ± 2% +186.19% (p=0.008 n=5+5) Decode/igmp-8 18.1ns ±44% 30.2ns ± 1% +66.89% (p=0.008 n=5+5) Decode/unknown-8 20.8ns ± 1% 10.6ns ± 9% -49.11% (p=0.016 n=4+5) pkg:tailscale.com/wgengine/filter goos:linux goarch:amd64 Filter/icmp4-8 30.5ns ± 1% 77.9ns ± 3% +155.01% (p=0.008 n=5+5) Filter/tcp4_syn_in-8 43.7ns ± 3% 123.0ns ± 3% +181.72% (p=0.008 n=5+5) Filter/tcp4_syn_out-8 24.5ns ± 2% 45.7ns ± 6% +86.22% (p=0.008 n=5+5) Filter/udp4_in-8 64.8ns ± 1% 210.0ns ± 2% +223.87% (p=0.008 n=5+5) Filter/udp4_out-8 119ns ± 0% 278ns ± 0% +133.78% (p=0.016 n=4+5) Filter/icmp6-8 40.3ns ± 2% 204.4ns ± 4% +407.70% (p=0.008 n=5+5) Filter/tcp6_syn_in-8 35.3ns ± 3% 199.2ns ± 2% +464.95% (p=0.008 n=5+5) Filter/tcp6_syn_out-8 32.8ns ± 2% 81.0ns ± 2% +147.10% (p=0.008 n=5+5) Filter/udp6_in-8 106ns ± 2% 290ns ± 2% +174.48% (p=0.008 n=5+5) Filter/udp6_out-8 184ns ± 2% 314ns ± 3% +70.43% (p=0.016 n=4+5) pkg:tailscale.com/wgengine/tstun goos:linux goarch:amd64 Write-8 9.02ns ± 3% 8.92ns ± 1% ~ (p=0.421 n=5+5) name old alloc/op new alloc/op delta pkg:tailscale.com/net/packet goos:linux goarch:amd64 Decode/tcp4-8 0.00B 0.00B ~ (all equal) Decode/tcp6-8 0.00B 0.00B ~ (all equal) Decode/udp4-8 0.00B 0.00B ~ (all equal) Decode/udp6-8 0.00B 0.00B ~ (all equal) Decode/icmp4-8 0.00B 0.00B ~ (all equal) Decode/icmp6-8 0.00B 0.00B ~ (all equal) Decode/igmp-8 0.00B 0.00B ~ (all equal) Decode/unknown-8 0.00B 0.00B ~ (all equal) pkg:tailscale.com/wgengine/filter goos:linux goarch:amd64 Filter/icmp4-8 0.00B 0.00B ~ (all equal) Filter/tcp4_syn_in-8 0.00B 0.00B ~ (all equal) Filter/tcp4_syn_out-8 0.00B 0.00B ~ (all equal) Filter/udp4_in-8 0.00B 0.00B ~ (all equal) Filter/udp4_out-8 16.0B ± 0% 64.0B ± 0% +300.00% (p=0.008 n=5+5) Filter/icmp6-8 0.00B 0.00B ~ (all equal) Filter/tcp6_syn_in-8 0.00B 0.00B ~ (all equal) Filter/tcp6_syn_out-8 0.00B 0.00B ~ (all equal) Filter/udp6_in-8 0.00B 0.00B ~ (all equal) Filter/udp6_out-8 48.0B ± 0% 64.0B ± 0% +33.33% (p=0.008 n=5+5) name old allocs/op new allocs/op delta pkg:tailscale.com/net/packet goos:linux goarch:amd64 Decode/tcp4-8 0.00 0.00 ~ (all equal) Decode/tcp6-8 0.00 0.00 ~ (all equal) Decode/udp4-8 0.00 0.00 ~ (all equal) Decode/udp6-8 0.00 0.00 ~ (all equal) Decode/icmp4-8 0.00 0.00 ~ (all equal) Decode/icmp6-8 0.00 0.00 ~ (all equal) Decode/igmp-8 0.00 0.00 ~ (all equal) Decode/unknown-8 0.00 0.00 ~ (all equal) pkg:tailscale.com/wgengine/filter goos:linux goarch:amd64 Filter/icmp4-8 0.00 0.00 ~ (all equal) Filter/tcp4_syn_in-8 0.00 0.00 ~ (all equal) Filter/tcp4_syn_out-8 0.00 0.00 ~ (all equal) Filter/udp4_in-8 0.00 0.00 ~ (all equal) Filter/udp4_out-8 1.00 ± 0% 1.00 ± 0% ~ (all equal) Filter/icmp6-8 0.00 0.00 ~ (all equal) Filter/tcp6_syn_in-8 0.00 0.00 ~ (all equal) Filter/tcp6_syn_out-8 0.00 0.00 ~ (all equal) Filter/udp6_in-8 0.00 0.00 ~ (all equal) Filter/udp6_out-8 1.00 ± 0% 1.00 ± 0% ~ (all equal) Signed-off-by: David Anderson <danderson@tailscale.com>
2020-12-20 00:43:25 +00:00
// okay to ignore `ok` here, because IPs pulled from packets are
// always well-formed stdlib IPs.
srcIP, _ := netaddr.FromStdIP(net.IP(b[8:24]))
dstIP, _ := netaddr.FromStdIP(net.IP(b[24:40]))
q.Src = q.Src.WithIP(srcIP)
q.Dst = q.Dst.WithIP(dstIP)
// We don't support any IPv6 extension headers. Don't try to
// be clever. Therefore, the IP subprotocol always starts at
// byte 40.
//
// Note that this means we don't support fragmentation in
// IPv6. This is fine, because IPv6 strongly mandates that you
// should not fragment, which makes fragmentation on the open
// internet extremely uncommon.
//
// This also means we don't support IPSec headers (AH/ESP), or
// IPv6 jumbo frames. Those will get marked Unknown and
// dropped.
q.subofs = 40
sub := b[q.subofs:]
sub = sub[:len(sub):len(sub)] // help the compiler do bounds check elimination
switch q.IPProto {
case ipproto.ICMPv6:
if len(sub) < icmp6HeaderLength {
q.IPProto = unknown
return
}
q.Src = q.Src.WithPort(0)
q.Dst = q.Dst.WithPort(0)
q.dataofs = q.subofs + icmp6HeaderLength
case ipproto.TCP:
if len(sub) < tcpHeaderLength {
q.IPProto = unknown
return
}
q.Src = q.Src.WithPort(binary.BigEndian.Uint16(sub[0:2]))
q.Dst = q.Dst.WithPort(binary.BigEndian.Uint16(sub[2:4]))
q.TCPFlags = TCPFlag(sub[13]) & 0x3F
headerLength := (sub[12] & 0xF0) >> 2
q.dataofs = q.subofs + int(headerLength)
return
case ipproto.UDP:
if len(sub) < udpHeaderLength {
q.IPProto = unknown
return
}
q.Src = q.Src.WithPort(binary.BigEndian.Uint16(sub[0:2]))
q.Dst = q.Dst.WithPort(binary.BigEndian.Uint16(sub[2:4]))
q.dataofs = q.subofs + udpHeaderLength
case ipproto.SCTP:
if len(sub) < sctpHeaderLength {
q.IPProto = unknown
return
}
q.Src = q.Src.WithPort(binary.BigEndian.Uint16(sub[0:2]))
q.Dst = q.Dst.WithPort(binary.BigEndian.Uint16(sub[2:4]))
return
case ipproto.TSMP:
// Inter-tailscale messages.
q.dataofs = q.subofs
return
default:
q.IPProto = unknown
return
}
}
func (q *Parsed) IP4Header() IP4Header {
if q.IPVersion != 4 {
panic("IP4Header called on non-IPv4 Parsed")
}
ipid := binary.BigEndian.Uint16(q.b[4:6])
return IP4Header{
IPID: ipid,
IPProto: q.IPProto,
Src: q.Src.IP(),
Dst: q.Dst.IP(),
}
}
func (q *Parsed) IP6Header() IP6Header {
if q.IPVersion != 6 {
panic("IP6Header called on non-IPv6 Parsed")
}
ipid := (binary.BigEndian.Uint32(q.b[:4]) << 12) >> 12
return IP6Header{
IPID: ipid,
IPProto: q.IPProto,
Src: q.Src.IP(),
Dst: q.Dst.IP(),
}
}
func (q *Parsed) ICMP4Header() ICMP4Header {
return ICMP4Header{
IP4Header: q.IP4Header(),
Type: ICMP4Type(q.b[q.subofs+0]),
Code: ICMP4Code(q.b[q.subofs+1]),
}
}
func (q *Parsed) ICMP6Header() ICMP6Header {
return ICMP6Header{
IP6Header: q.IP6Header(),
Type: ICMP6Type(q.b[q.subofs+0]),
Code: ICMP6Code(q.b[q.subofs+1]),
}
}
func (q *Parsed) UDP4Header() UDP4Header {
return UDP4Header{
IP4Header: q.IP4Header(),
SrcPort: q.Src.Port(),
DstPort: q.Dst.Port(),
}
}
// Buffer returns the entire packet buffer.
// This is a read-only view; that is, q retains the ownership of the buffer.
func (q *Parsed) Buffer() []byte {
return q.b
}
// Payload returns the payload of the IP subprotocol section.
// This is a read-only view; that is, q retains the ownership of the buffer.
func (q *Parsed) Payload() []byte {
return q.b[q.dataofs:q.length]
}
// IsTCPSyn reports whether q is a TCP SYN packet
// (i.e. the first packet in a new connection).
func (q *Parsed) IsTCPSyn() bool {
return (q.TCPFlags & TCPSynAck) == TCPSyn
}
// IsError reports whether q is an ICMP "Error" packet.
func (q *Parsed) IsError() bool {
switch q.IPProto {
case ipproto.ICMPv4:
if len(q.b) < q.subofs+8 {
return false
}
t := ICMP4Type(q.b[q.subofs])
return t == ICMP4Unreachable || t == ICMP4TimeExceeded
case ipproto.ICMPv6:
if len(q.b) < q.subofs+8 {
return false
}
t := ICMP6Type(q.b[q.subofs])
return t == ICMP6Unreachable || t == ICMP6TimeExceeded
default:
return false
}
}
// IsEchoRequest reports whether q is an ICMP Echo Request.
func (q *Parsed) IsEchoRequest() bool {
switch q.IPProto {
case ipproto.ICMPv4:
return len(q.b) >= q.subofs+8 && ICMP4Type(q.b[q.subofs]) == ICMP4EchoRequest && ICMP4Code(q.b[q.subofs+1]) == ICMP4NoCode
case ipproto.ICMPv6:
return len(q.b) >= q.subofs+8 && ICMP6Type(q.b[q.subofs]) == ICMP6EchoRequest && ICMP6Code(q.b[q.subofs+1]) == ICMP6NoCode
default:
return false
}
}
// IsEchoResponse reports whether q is an IPv4 ICMP Echo Response.
func (q *Parsed) IsEchoResponse() bool {
switch q.IPProto {
case ipproto.ICMPv4:
return len(q.b) >= q.subofs+8 && ICMP4Type(q.b[q.subofs]) == ICMP4EchoReply && ICMP4Code(q.b[q.subofs+1]) == ICMP4NoCode
case ipproto.ICMPv6:
return len(q.b) >= q.subofs+8 && ICMP6Type(q.b[q.subofs]) == ICMP6EchoReply && ICMP6Code(q.b[q.subofs+1]) == ICMP6NoCode
default:
return false
}
}
func Hexdump(b []byte) string {
out := new(strings.Builder)
for i := 0; i < len(b); i += 16 {
if i > 0 {
fmt.Fprintf(out, "\n")
}
fmt.Fprintf(out, " %04x ", i)
j := 0
for ; j < 16 && i+j < len(b); j++ {
if j == 8 {
fmt.Fprintf(out, " ")
}
fmt.Fprintf(out, "%02x ", b[i+j])
}
for ; j < 16; j++ {
if j == 8 {
fmt.Fprintf(out, " ")
}
fmt.Fprintf(out, " ")
}
fmt.Fprintf(out, " ")
for j = 0; j < 16 && i+j < len(b); j++ {
if b[i+j] >= 32 && b[i+j] < 128 {
fmt.Fprintf(out, "%c", b[i+j])
} else {
fmt.Fprintf(out, ".")
}
}
}
return out.String()
}