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| author |   Josh Bleecher Snyder <josharian@gmail.com> | 2020-08-13 15:39:09 -0700 |
|---|---|---|
| committer |   Josh Bleecher Snyder <josh@tailscale.com> | 2020-12-08 14:27:36 -0800 |
| commit | f64d2a2bbc915338d8c77700883466be0e2dee87 (patch) | |
| tree | fe9a1b97b87d150f9330523c246d49791c09397a | |
| parent | device: avoid copying lock in tests (diff) | |
| download | wireguard-go-f64d2a2bbc915338d8c77700883466be0e2dee87.tar.xz wireguard-go-f64d2a2bbc915338d8c77700883466be0e2dee87.zip | |
tun/tuntest: make genICMPv4 allocate less
It doesn't really matter, because it is only used in tests,
but it does remove some noise from pprof profiles.
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
| -rw-r--r-- | tun/tuntest/tuntest.go | 15 |
1 files changed, 7 insertions, 8 deletions
diff --git a/tun/tuntest/tuntest.go b/tun/tuntest/tuntest.go index e94c6d8..efafebe 100644 --- a/tun/tuntest/tuntest.go +++ b/tun/tuntest/tuntest.go @@ -50,12 +50,13 @@ func genICMPv4(payload []byte, dst, src net.IP) []byte { ipv4TotalLenOffset = 2 ipv4ChecksumOffset = 10 ttl = 65 + headerSize = ipv4Size + icmpv4Size ) - hdr := make([]byte, ipv4Size+icmpv4Size) + pkt := make([]byte, headerSize+len(payload)) - ip := hdr[0:ipv4Size] - icmpv4 := hdr[ipv4Size : ipv4Size+icmpv4Size] + ip := pkt[0:ipv4Size] + icmpv4 := pkt[ipv4Size : ipv4Size+icmpv4Size] // https://tools.ietf.org/html/rfc792 icmpv4[0] = icmpv4Echo // type @@ -64,7 +65,7 @@ func genICMPv4(payload []byte, dst, src net.IP) []byte { binary.BigEndian.PutUint16(icmpv4[icmpv4ChecksumOffset:], chksum) // https://tools.ietf.org/html/rfc760 section 3.1 - length := uint16(len(hdr) + len(payload)) + length := uint16(len(pkt)) ip[0] = (4 << 4) | (ipv4Size / 4) binary.BigEndian.PutUint16(ip[ipv4TotalLenOffset:], length) ip[8] = ttl @@ -74,10 +75,8 @@ func genICMPv4(payload []byte, dst, src net.IP) []byte { chksum = ^checksum(ip[:], 0) binary.BigEndian.PutUint16(ip[ipv4ChecksumOffset:], chksum) - var v []byte - v = append(v, hdr...) - v = append(v, payload...) - return []byte(v) + copy(pkt[headerSize:], payload) + return pkt } // TODO(crawshaw): find a reusable home for this. package devicetest? |