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Update switch flow separation for IPv4

This commit is contained in:
Neil Alexander 2019-01-21 12:27:29 +00:00
parent 9d5085492e
commit cdfb930703
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@ -554,23 +554,36 @@ func (sinfo *sessionInfo) doSend(bs []byte) {
} }
// code isn't multithreaded so appending to this is safe // code isn't multithreaded so appending to this is safe
coords := sinfo.coords coords := sinfo.coords
// Read IPv6 flowlabel field (20 bits). var flowkey uint64
// Assumes packet at least contains IPv6 header. // Try to read IPv6 flowlabel field (20 bits)
flowkey := uint64(bs[1]&0x0f)<<16 | uint64(bs[2])<<8 | uint64(bs[3]) if bs[0]&0xf0 == 0x60 {
// Check if the flowlabel was specified flowkey = uint64(bs[1]&0x0f)<<16 | uint64(bs[2])<<8 | uint64(bs[3])
}
// Check if the flowlabel was specified. If not then try to use known
// protocols' ports: protokey: proto | sport | dport
if flowkey == 0 { if flowkey == 0 {
// Is the protocol TCP, UDP, SCTP?
switch bs[0] & 0xf0 {
case 0x40: // IPv4 packet
if len(bs) >= 24 {
if bs[9] == 0x06 || bs[9] == 0x11 || bs[9] == 0x84 {
ihl := bs[0] & 0x0f * 4 // Header length
flowkey = uint64(bs[9])<<32 /* proto */ |
uint64(bs[ihl+0])<<24 | uint64(bs[ihl+1])<<16 /* sport */ |
uint64(bs[ihl+2])<<8 | uint64(bs[ihl+3]) /* dport */
}
}
case 0x60: // IPv6 packet
// Does the packet meet the minimum UDP packet size? (others are bigger) // Does the packet meet the minimum UDP packet size? (others are bigger)
if len(bs) >= 48 { if len(bs) >= 48 {
// Is the protocol TCP, UDP, SCTP?
if bs[6] == 0x06 || bs[6] == 0x11 || bs[6] == 0x84 { if bs[6] == 0x06 || bs[6] == 0x11 || bs[6] == 0x84 {
// if flowlabel was unspecified (0), try to use known protocols' ports
// protokey: proto | sport | dport
flowkey = uint64(bs[6])<<32 /* proto */ | flowkey = uint64(bs[6])<<32 /* proto */ |
uint64(bs[40])<<24 | uint64(bs[41])<<16 /* sport */ | uint64(bs[40])<<24 | uint64(bs[41])<<16 /* sport */ |
uint64(bs[42])<<8 | uint64(bs[43]) /* dport */ uint64(bs[42])<<8 | uint64(bs[43]) /* dport */
} }
} }
} }
}
// If we have a flowkey, either through the IPv6 flowlabel field or through // If we have a flowkey, either through the IPv6 flowlabel field or through
// known TCP/UDP/SCTP proto-sport-dport triplet, then append it to the coords. // known TCP/UDP/SCTP proto-sport-dport triplet, then append it to the coords.
// Appending extra coords after a 0 ensures that we still target the local router // Appending extra coords after a 0 ensures that we still target the local router