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| author | gVisor bot <gvisor-bot@google.com> | 2021-01-23 00:23:34 +0000 |
|---|---|---|
| committer | gVisor bot <gvisor-bot@google.com> | 2021-01-23 00:23:34 +0000 |
| commit | 21c64a9aad986590172ef814f2bd0335a2b88399 (patch) | |
| tree | 4b6a92af8753865c1049f17cb3e44f55373c7ef7 /pkg | |
| parent | 9e2762d9c5704a608a008b4b9da5264834303286 (diff) | |
| parent | 76da673a0ddaf33e410d48501a9b089979411d4d (diff) | |
Merge release-20210112.0-77-g76da673a0 (automated)
Diffstat (limited to 'pkg')
| -rw-r--r-- | pkg/tcpip/network/ipv4/igmp.go | 15 |
1 files changed, 7 insertions, 8 deletions
diff --git a/pkg/tcpip/network/ipv4/igmp.go b/pkg/tcpip/network/ipv4/igmp.go index 9515fde45..4550aacd6 100644 --- a/pkg/tcpip/network/ipv4/igmp.go +++ b/pkg/tcpip/network/ipv4/igmp.go @@ -157,14 +157,13 @@ func (igmp *igmpState) handleIGMP(pkt *stack.PacketBuffer) { } h := header.IGMP(headerView) - // Temporarily reset the checksum field to 0 in order to calculate the proper - // checksum. - wantChecksum := h.Checksum() - h.SetChecksum(0) - gotChecksum := ^header.ChecksumVV(pkt.Data, 0 /* initial */) - h.SetChecksum(wantChecksum) - - if gotChecksum != wantChecksum { + // As per RFC 1071 section 1.3, + // + // To check a checksum, the 1's complement sum is computed over the + // same set of octets, including the checksum field. If the result + // is all 1 bits (-0 in 1's complement arithmetic), the check + // succeeds. + if header.ChecksumVV(pkt.Data, 0 /* initial */) != 0xFFFF { received.checksumErrors.Increment() return } |