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cb96b14bf4
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>
77 lines
1.9 KiB
Go
77 lines
1.9 KiB
Go
// Copyright (c) 2020 Tailscale Inc & AUTHORS All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package packet
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import (
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"encoding/binary"
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"inet.af/netaddr"
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)
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// ip6HeaderLength is the length of an IPv6 header with no IP options.
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const ip6HeaderLength = 40
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// IP6Header represents an IPv6 packet header.
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type IP6Header struct {
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IPProto IPProto
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IPID uint32 // only lower 20 bits used
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Src netaddr.IP
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Dst netaddr.IP
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}
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// Len implements Header.
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func (h IP6Header) Len() int {
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return ip6HeaderLength
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}
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// Marshal implements Header.
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func (h IP6Header) Marshal(buf []byte) error {
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if len(buf) < h.Len() {
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return errSmallBuffer
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}
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if len(buf) > maxPacketLength {
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return errLargePacket
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}
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binary.BigEndian.PutUint32(buf[:4], h.IPID&0x000FFFFF)
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buf[0] = 0x60
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binary.BigEndian.PutUint16(buf[4:6], uint16(len(buf)-ip6HeaderLength)) // Total length
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buf[6] = uint8(h.IPProto) // Inner protocol
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buf[7] = 64 // TTL
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src, dst := h.Src.As16(), h.Dst.As16()
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copy(buf[8:24], src[:])
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copy(buf[24:40], dst[:])
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return nil
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}
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// ToResponse implements Header.
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func (h *IP6Header) ToResponse() {
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h.Src, h.Dst = h.Dst, h.Src
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// Flip the bits in the IPID. If incoming IPIDs are distinct, so are these.
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h.IPID = (^h.IPID) & 0x000FFFFF
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}
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// marshalPseudo serializes h into buf in the "pseudo-header" form
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// required when calculating UDP checksums.
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func (h IP6Header) marshalPseudo(buf []byte) error {
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if len(buf) < h.Len() {
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return errSmallBuffer
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}
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if len(buf) > maxPacketLength {
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return errLargePacket
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}
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src, dst := h.Src.As16(), h.Dst.As16()
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copy(buf[:16], src[:])
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copy(buf[16:32], dst[:])
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binary.BigEndian.PutUint32(buf[32:36], uint32(len(buf)-h.Len()))
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buf[36] = 0
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buf[37] = 0
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buf[38] = 0
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buf[39] = 17 // NextProto
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return nil
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}
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