netbird/gvisor
0
0
Fork 0
mirror of https://github.com/netbirdio/gvisor.git synced 2026-05-22 17:12:49 -07:00
Code Issues Packages Projects Releases Wiki Activity

gro: factor out TCP checks

Browse Source 
PiperOrigin-RevId: 513599763
This commit is contained in:
Kevin Krakauer
2023-03-02 11:57:10 -08:00
committed by gVisor bot
parent 20270e4268
commit e825c7d5e0
1 changed files with 26 additions and 16 deletions
Download Patch File Download Diff File Expand all files Collapse all files
pkg/tcpip/stack/gro.go
+26 -16
View File
@@ -140,25 +140,12 @@ func (gb *groBucket) findGROPacket(pkt PacketBufferPtr, ipHdr header.IPv4, tcpHd
}
// TCP checks.
flags := tcpHdr.Flags()
groPktFlags := groPkt.tcpHdr.Flags()
dataOff := tcpHdr.DataOffset()
if flags&header.TCPFlagCwr != 0 || // Is congestion control occurring?
(flags^groPktFlags)&^(header.TCPFlagCwr|header.TCPFlagFin|header.TCPFlagPsh) != 0 || // Do the flags differ besides CRW, FIN, and PSH?
tcpHdr.AckNumber() != groPkt.tcpHdr.AckNumber() || // Do the ACKs match?
dataOff != groPkt.tcpHdr.DataOffset() || // Are the TCP headers the same length?
groPkt.tcpHdr.SequenceNumber()+uint32(groPkt.payloadSize()) != tcpHdr.SequenceNumber() { // Does the incoming packet match the expected sequence number?
if shouldFlushTCP(groPkt, tcpHdr) {
return groPkt, true
}
// The options, including timestamps, must be identical.
for i := header.TCPMinimumSize; i < int(dataOff); i++ {
if tcpHdr[i] != groPkt.tcpHdr[i] {
return groPkt, true
}
}
// There's an upper limit on coalesced packet size.
if pkt.Data().Size()-header.IPv4MinimumSize-int(dataOff)+groPkt.pkt.Data().Size() >= groMaxPacketSize {
if pkt.Data().Size()-header.IPv4MinimumSize-int(tcpHdr.DataOffset())+groPkt.pkt.Data().Size() >= groMaxPacketSize {
return groPkt, true
}
@@ -171,6 +158,7 @@ func (gb *groBucket) findGROPacket(pkt PacketBufferPtr, ipHdr header.IPv4, tcpHd
// +checklocks:gb.mu
func (gb *groBucket) found(groPkt *groPacket, flushGROPkt bool, pkt PacketBufferPtr, ipHdr header.IPv4, tcpHdr header.TCP, ep NetworkEndpoint) {
// Flush groPkt or merge the packets.
pktSize := pkt.Data().Size()
flags := tcpHdr.Flags()
if flushGROPkt {
// Flush the existing GRO packet. Don't hold bucket.mu while
@@ -208,7 +196,7 @@ func (gb *groBucket) found(groPkt *groPacket, flushGROPkt bool, pkt PacketBuffer
// GRO.
flush := header.TCPFlags(flags)&(header.TCPFlagUrg|header.TCPFlagPsh|header.TCPFlagRst|header.TCPFlagSyn|header.TCPFlagFin) != 0
if groPkt != nil {
flush = flush || pkt.Data().Size() != groPkt.initialLength
flush = flush || pktSize != groPkt.initialLength
}
switch {
@@ -540,3 +528,25 @@ func (gd *groDispatcher) String() string {
}
return ret
}
// shouldFlushTCP returns whether the TCP headers indicate that groPkt should
// be flushed
func shouldFlushTCP(groPkt *groPacket, tcpHdr header.TCP) bool {
flags := tcpHdr.Flags()
groPktFlags := groPkt.tcpHdr.Flags()
dataOff := tcpHdr.DataOffset()
if flags&header.TCPFlagCwr != 0 || // Is congestion control occurring?
(flags^groPktFlags)&^(header.TCPFlagCwr|header.TCPFlagFin|header.TCPFlagPsh) != 0 || // Do the flags differ besides CRW, FIN, and PSH?
tcpHdr.AckNumber() != groPkt.tcpHdr.AckNumber() || // Do the ACKs match?
dataOff != groPkt.tcpHdr.DataOffset() || // Are the TCP headers the same length?
groPkt.tcpHdr.SequenceNumber()+uint32(groPkt.payloadSize()) != tcpHdr.SequenceNumber() { // Does the incoming packet match the expected sequence number?
return true
}
// The options, including timestamps, must be identical.
for i := header.TCPMinimumSize; i < int(dataOff); i++ {
if tcpHdr[i] != groPkt.tcpHdr[i] {
return true
}
}
return false
}