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>
This commit is contained in:
David Anderson
committed by
Brad Fitzpatrick
Brad Fitzpatrick
parent
d0baece5fa
commit
cb96b14bf4
@ -6,47 +6,11 @@ package packet
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import (
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"encoding/binary"
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"fmt"
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"errors"
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"inet.af/netaddr"
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)
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// IP4 is an IPv4 address.
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type IP4 uint32
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// IPFromNetaddr converts a netaddr.IP to an IP4. Panics if !ip.Is4.
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func IP4FromNetaddr(ip netaddr.IP) IP4 {
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ipbytes := ip.As4()
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return IP4(binary.BigEndian.Uint32(ipbytes[:]))
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}
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// Netaddr converts ip to a netaddr.IP.
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func (ip IP4) Netaddr() netaddr.IP {
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return netaddr.IPv4(byte(ip>>24), byte(ip>>16), byte(ip>>8), byte(ip))
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}
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func (ip IP4) String() string {
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return fmt.Sprintf("%d.%d.%d.%d", byte(ip>>24), byte(ip>>16), byte(ip>>8), byte(ip))
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}
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// IsMulticast returns whether ip is a multicast address.
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func (ip IP4) IsMulticast() bool {
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return byte(ip>>24)&0xf0 == 0xe0
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}
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// IsLinkLocalUnicast returns whether ip is a link-local unicast
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// address.
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func (ip IP4) IsLinkLocalUnicast() bool {
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return byte(ip>>24) == 169 && byte(ip>>16) == 254
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}
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// IsMostLinkLocalUnicast returns whether ip is a link-local unicast
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// address other than the magical "169.254.169.254" address used by
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// GCP DNS.
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func (ip IP4) IsMostLinkLocalUnicast() bool {
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return ip.IsLinkLocalUnicast() && ip != 0xA9FEA9FE
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}
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// ip4HeaderLength is the length of an IPv4 header with no IP options.
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const ip4HeaderLength = 20
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@ -54,8 +18,8 @@ const ip4HeaderLength = 20
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type IP4Header struct {
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IPProto IPProto
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IPID uint16
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SrcIP IP4
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DstIP IP4
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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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@ -63,6 +27,8 @@ func (h IP4Header) Len() int {
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return ip4HeaderLength
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}
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var errWrongFamily = errors.New("wrong address family for src/dst IP")
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// Marshal implements Header.
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func (h IP4Header) Marshal(buf []byte) error {
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if len(buf) < h.Len() {
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@ -71,6 +37,9 @@ func (h IP4Header) Marshal(buf []byte) error {
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if len(buf) > maxPacketLength {
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return errLargePacket
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}
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if !h.Src.Is4() || !h.Dst.Is4() {
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return errWrongFamily
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}
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buf[0] = 0x40 | (byte(h.Len() >> 2)) // IPv4 + IHL
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buf[1] = 0x00 // DSCP + ECN
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@ -83,8 +52,10 @@ func (h IP4Header) Marshal(buf []byte) error {
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// it later, because the checksum computation runs over these
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// bytes and expects them to be zero.
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binary.BigEndian.PutUint16(buf[10:12], 0)
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binary.BigEndian.PutUint32(buf[12:16], uint32(h.SrcIP)) // Src
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binary.BigEndian.PutUint32(buf[16:20], uint32(h.DstIP)) // Dst
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src := h.Src.As4()
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dst := h.Dst.As4()
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copy(buf[12:16], src[:])
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copy(buf[16:20], dst[:])
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binary.BigEndian.PutUint16(buf[10:12], ip4Checksum(buf[0:20])) // Checksum
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@ -93,7 +64,7 @@ func (h IP4Header) Marshal(buf []byte) error {
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// ToResponse implements Header.
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func (h *IP4Header) ToResponse() {
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h.SrcIP, h.DstIP = h.DstIP, h.SrcIP
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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
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}
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@ -135,8 +106,9 @@ func (h IP4Header) marshalPseudo(buf []byte) error {
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}
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length := len(buf) - h.Len()
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binary.BigEndian.PutUint32(buf[8:12], uint32(h.SrcIP))
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binary.BigEndian.PutUint32(buf[12:16], uint32(h.DstIP))
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src, dst := h.Src.As4(), h.Dst.As4()
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copy(buf[8:12], src[:])
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copy(buf[12:16], dst[:])
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buf[16] = 0x0
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buf[17] = uint8(h.IPProto)
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binary.BigEndian.PutUint16(buf[18:20], uint16(length))
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