afpacket/pcapgo: fix htons in big endian systems#75
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mosajjal merged 1 commit intogopacket:masterfrom Nov 9, 2024
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The old implementation swaps the bits regardless of the host endianess. Signed-off-by: wagner riffel <w@104d.net>
mosajjal
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Nov 9, 2024
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I don't think the use of unsafe is justified here. Surprisingly, idiomatic dumb code is pretty efficient: func htons(v uint16) uint16 {
var buf [4]byte
binary.NativeEndian.PutUint16(buf[:], v)
return binary.BigEndian.Uint16(buf[:])
} |
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Currently afpacket/pcapgo fails to receive any packet in big endian hosts because the interface index is never matched due the swap, regardless the host endianess
An alternative for unsafe would be add a dependency to Go maintained x/sys/cpu and hope the tag list is maintained accordingly as architectures are added and removed, I found it too big of a dependency for a simple question, and that's cheap to compute at runtime, but it's up to you.