Use flow label instead of TCP/UDP/SCTP source/destination ports

This commit is contained in:
Neil Alexander 2018-07-22 18:16:03 +01:00
parent 3f4295f8cd
commit 81fde1a805
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GPG Key ID: A02A2019A2BB0944

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@ -429,30 +429,20 @@ func (sinfo *sessionInfo) doSend(bs []byte) {
// Specifically, we append a 0, and then arbitrary data
// The 0 ensures that the destination node switch forwards to the self peer (router)
// The rest is ignored, but it's still part as the coords, so it affects switch queues
// This helps separate traffic streams (protocol + source + dest port) are queued independently
// This helps separate traffic streams (coords, flowlabel) to be queued independently
var coords []byte
addUint64 := func(bs []byte) {
// Converts bytes to a uint64
// Converts that back to variable length bytes
// Appends it to coords
var u uint64
for _, b := range bs {
u <<= 8
u |= uint64(b)
}
coords = append(coords, wire_encode_uint64(u)...)
}
coords = append(coords, sinfo.coords...) // Start with the real coords
flowlabel := int(bs[1:2][0]&0x0f)<<16 | int(bs[2:3][0])<<8 | int(bs[3:4][0])
if flowlabel > 0 {
coords = append(coords, 0) // Add an explicit 0 for the destination's self peer
addUint64(bs[6:7]) // Byte 6, next header type (e.g. TCP vs UDP)
// Is the next header TCP, UDP, SCTP for finding source port?
// 0x06 (6) = TCP, 0x11 (17) = UDP, 0x84 (132) = SCTP
// TODO: Perhaps improve this for other protocols
// TODO: Consider that the Next Header could be an IPv6 Extension Header instead
if bs[6:7][0] == 0x06 || bs[6:7][0] == 0x11 || bs[6:7][0] == 0x84 {
if len(bs) > 44 {
addUint64(bs[40:42]) // Bytes 40-41, source port for TCP/UDP/SCTP
addUint64(bs[42:44]) // Bytes 42-43, destination port for TCP/UDP/SCTP
if flowlabel>>16 > 0 {
coords = append(coords, byte(flowlabel>>16))
}
if flowlabel>>8 > 0 {
coords = append(coords, byte(flowlabel>>8))
}
if flowlabel>>0 > 0 {
coords = append(coords, byte(flowlabel>>0))
}
}
payload, nonce := boxSeal(&sinfo.sharedSesKey, bs, &sinfo.myNonce)