25eb973e00
Replace the src storage inside StdNetEndpoint with a copy of the raw control message buffer, to reduce allocation and perform less work on a per-packet basis. Signed-off-by: James Tucker <james@tailscale.com> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
111 lines
3.0 KiB
Go
111 lines
3.0 KiB
Go
//go:build linux && !android
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/* SPDX-License-Identifier: MIT
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*
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* Copyright (C) 2017-2023 WireGuard LLC. All Rights Reserved.
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*/
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package conn
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import (
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"net/netip"
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"unsafe"
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"golang.org/x/sys/unix"
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)
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func (e *StdNetEndpoint) SrcIP() netip.Addr {
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switch len(e.src) {
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case unix.CmsgSpace(unix.SizeofInet4Pktinfo):
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info := (*unix.Inet4Pktinfo)(unsafe.Pointer(&e.src[unix.CmsgLen(0)]))
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return netip.AddrFrom4(info.Spec_dst)
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case unix.CmsgSpace(unix.SizeofInet6Pktinfo):
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info := (*unix.Inet6Pktinfo)(unsafe.Pointer(&e.src[unix.CmsgLen(0)]))
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// TODO: set zone. in order to do so we need to check if the address is
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// link local, and if it is perform a syscall to turn the ifindex into a
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// zone string because netip uses string zones.
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return netip.AddrFrom16(info.Addr)
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}
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return netip.Addr{}
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}
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func (e *StdNetEndpoint) SrcIfidx() int32 {
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switch len(e.src) {
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case unix.CmsgSpace(unix.SizeofInet4Pktinfo):
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info := (*unix.Inet4Pktinfo)(unsafe.Pointer(&e.src[unix.CmsgLen(0)]))
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return info.Ifindex
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case unix.CmsgSpace(unix.SizeofInet6Pktinfo):
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info := (*unix.Inet6Pktinfo)(unsafe.Pointer(&e.src[unix.CmsgLen(0)]))
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return int32(info.Ifindex)
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}
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return 0
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}
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func (e *StdNetEndpoint) SrcToString() string {
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return e.SrcIP().String()
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}
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// getSrcFromControl parses the control for PKTINFO and if found updates ep with
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// the source information found.
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func getSrcFromControl(control []byte, ep *StdNetEndpoint) {
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ep.ClearSrc()
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var (
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hdr unix.Cmsghdr
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data []byte
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rem []byte = control
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err error
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)
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for len(rem) > unix.SizeofCmsghdr {
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hdr, data, rem, err = unix.ParseOneSocketControlMessage(rem)
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if err != nil {
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return
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}
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if hdr.Level == unix.IPPROTO_IP &&
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hdr.Type == unix.IP_PKTINFO {
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if ep.src == nil || cap(ep.src) < unix.CmsgSpace(unix.SizeofInet4Pktinfo) {
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ep.src = make([]byte, 0, unix.CmsgSpace(unix.SizeofInet4Pktinfo))
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}
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ep.src = ep.src[:unix.CmsgSpace(unix.SizeofInet4Pktinfo)]
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hdrBuf := unsafe.Slice((*byte)(unsafe.Pointer(&hdr)), unix.SizeofCmsghdr)
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copy(ep.src, hdrBuf)
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copy(ep.src[unix.CmsgLen(0):], data)
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return
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}
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if hdr.Level == unix.IPPROTO_IPV6 &&
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hdr.Type == unix.IPV6_PKTINFO {
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if ep.src == nil || cap(ep.src) < unix.CmsgSpace(unix.SizeofInet6Pktinfo) {
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ep.src = make([]byte, 0, unix.CmsgSpace(unix.SizeofInet6Pktinfo))
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}
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ep.src = ep.src[:unix.CmsgSpace(unix.SizeofInet6Pktinfo)]
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hdrBuf := unsafe.Slice((*byte)(unsafe.Pointer(&hdr)), unix.SizeofCmsghdr)
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copy(ep.src, hdrBuf)
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copy(ep.src[unix.CmsgLen(0):], data)
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return
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}
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}
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}
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// setSrcControl sets an IP{V6}_PKTINFO in control based on the source address
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// and source ifindex found in ep. control's len will be set to 0 in the event
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// that ep is a default value.
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func setSrcControl(control *[]byte, ep *StdNetEndpoint) {
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if cap(*control) < len(ep.src) {
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return
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}
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*control = (*control)[:0]
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*control = append(*control, ep.src...)
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}
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var srcControlSize = unix.CmsgSpace(unix.SizeofInet6Pktinfo)
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const StdNetSupportsStickySockets = true
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