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-rw-r--r--pkg/tcpip/network/ipv4/ipv4.go81
-rw-r--r--pkg/tcpip/network/ipv6/ipv6.go25
2 files changed, 65 insertions, 41 deletions
diff --git a/pkg/tcpip/network/ipv4/ipv4.go b/pkg/tcpip/network/ipv4/ipv4.go
index 7e2e53523..743aa0575 100644
--- a/pkg/tcpip/network/ipv4/ipv4.go
+++ b/pkg/tcpip/network/ipv4/ipv4.go
@@ -190,29 +190,6 @@ func (e *endpoint) NetworkProtocolNumber() tcpip.NetworkProtocolNumber {
return e.protocol.Number()
}
-// writePacketFragments fragments pkt and writes the results on the link
-// endpoint. The IP header must already present in the original packet. The mtu
-// is the maximum size of the packets.
-func (e *endpoint) writePacketFragments(r *stack.Route, gso *stack.GSO, mtu uint32, pkt *stack.PacketBuffer) *tcpip.Error {
- networkHeader := header.IPv4(pkt.NetworkHeader().View())
- fragMTU := int(calculateFragmentInnerMTU(mtu, pkt))
- pf := fragmentation.MakePacketFragmenter(pkt, fragMTU, pkt.AvailableHeaderBytes()+len(networkHeader))
-
- for {
- fragPkt, more := buildNextFragment(&pf, networkHeader)
- if err := e.nic.WritePacket(r, gso, ProtocolNumber, fragPkt); err != nil {
- r.Stats().IP.OutgoingPacketErrors.IncrementBy(uint64(pf.RemainingFragmentCount() + 1))
- return err
- }
- r.Stats().IP.PacketsSent.Increment()
- if !more {
- break
- }
- }
-
- return nil
-}
-
func (e *endpoint) addIPHeader(r *stack.Route, pkt *stack.PacketBuffer, params stack.NetworkHeaderParams) {
ip := header.IPv4(pkt.NetworkHeader().Push(header.IPv4MinimumSize))
length := uint16(pkt.Size())
@@ -234,6 +211,32 @@ func (e *endpoint) addIPHeader(r *stack.Route, pkt *stack.PacketBuffer, params s
pkt.NetworkProtocolNumber = ProtocolNumber
}
+func (e *endpoint) packetMustBeFragmented(pkt *stack.PacketBuffer, gso *stack.GSO) bool {
+ return (gso == nil || gso.Type == stack.GSONone) && pkt.Size() > int(e.nic.MTU())
+}
+
+// handleFragments fragments pkt and calls the handler function on each
+// fragment. It returns the number of fragments handled and the number of
+// fragments left to be processed. The IP header must already be present in the
+// original packet. The mtu is the maximum size of the packets.
+func (e *endpoint) handleFragments(r *stack.Route, gso *stack.GSO, mtu uint32, pkt *stack.PacketBuffer, handler func(*stack.PacketBuffer) *tcpip.Error) (int, int, *tcpip.Error) {
+ fragMTU := int(calculateFragmentInnerMTU(mtu, pkt))
+ networkHeader := header.IPv4(pkt.NetworkHeader().View())
+ pf := fragmentation.MakePacketFragmenter(pkt, fragMTU, pkt.AvailableHeaderBytes()+len(networkHeader))
+
+ var n int
+ for {
+ fragPkt, more := buildNextFragment(&pf, networkHeader)
+ if err := handler(fragPkt); err != nil {
+ return n, pf.RemainingFragmentCount() + 1, err
+ }
+ n++
+ if !more {
+ return n, pf.RemainingFragmentCount(), nil
+ }
+ }
+}
+
// WritePacket writes a packet to the given destination address and protocol.
func (e *endpoint) WritePacket(r *stack.Route, gso *stack.GSO, params stack.NetworkHeaderParams, pkt *stack.PacketBuffer) *tcpip.Error {
e.addIPHeader(r, pkt, params)
@@ -276,8 +279,18 @@ func (e *endpoint) writePacket(r *stack.Route, gso *stack.GSO, pkt *stack.Packet
if r.Loop&stack.PacketOut == 0 {
return nil
}
- if pkt.Size() > int(e.nic.MTU()) && (gso == nil || gso.Type == stack.GSONone) {
- return e.writePacketFragments(r, gso, e.nic.MTU(), pkt)
+
+ if e.packetMustBeFragmented(pkt, gso) {
+ sent, remain, err := e.handleFragments(r, gso, e.nic.MTU(), pkt, func(fragPkt *stack.PacketBuffer) *tcpip.Error {
+ // TODO(gvisor.dev/issue/3884): Evaluate whether we want to send each
+ // fragment one by one using WritePacket() (current strategy) or if we
+ // want to create a PacketBufferList from the fragments and feed it to
+ // WritePackets(). It'll be faster but cost more memory.
+ return e.nic.WritePacket(r, gso, ProtocolNumber, fragPkt)
+ })
+ r.Stats().IP.PacketsSent.IncrementBy(uint64(sent))
+ r.Stats().IP.OutgoingPacketErrors.IncrementBy(uint64(remain))
+ return err
}
if err := e.nic.WritePacket(r, gso, ProtocolNumber, pkt); err != nil {
r.Stats().IP.OutgoingPacketErrors.Increment()
@@ -296,9 +309,23 @@ func (e *endpoint) WritePackets(r *stack.Route, gso *stack.GSO, pkts stack.Packe
return pkts.Len(), nil
}
- for pkt := pkts.Front(); pkt != nil; {
+ for pkt := pkts.Front(); pkt != nil; pkt = pkt.Next() {
e.addIPHeader(r, pkt, params)
- pkt = pkt.Next()
+ if e.packetMustBeFragmented(pkt, gso) {
+ // Keep track of the packet that is about to be fragmented so it can be
+ // removed once the fragmentation is done.
+ originalPkt := pkt
+ if _, _, err := e.handleFragments(r, gso, e.nic.MTU(), pkt, func(fragPkt *stack.PacketBuffer) *tcpip.Error {
+ // Modify the packet list in place with the new fragments.
+ pkts.InsertAfter(pkt, fragPkt)
+ pkt = fragPkt
+ return nil
+ }); err != nil {
+ panic(fmt.Sprintf("e.handleFragments(_, _, %d, _, _) = %s", e.nic.MTU(), err))
+ }
+ // Remove the packet that was just fragmented and process the rest.
+ pkts.Remove(originalPkt)
+ }
}
nicName := e.protocol.stack.FindNICNameFromID(e.nic.ID())
diff --git a/pkg/tcpip/network/ipv6/ipv6.go b/pkg/tcpip/network/ipv6/ipv6.go
index 632914dd6..9670696c7 100644
--- a/pkg/tcpip/network/ipv6/ipv6.go
+++ b/pkg/tcpip/network/ipv6/ipv6.go
@@ -387,7 +387,7 @@ func (e *endpoint) addIPHeader(r *stack.Route, pkt *stack.PacketBuffer, params s
}
func (e *endpoint) packetMustBeFragmented(pkt *stack.PacketBuffer, gso *stack.GSO) bool {
- return pkt.Size() > int(e.nic.MTU()) && (gso == nil || gso.Type == stack.GSONone)
+ return (gso == nil || gso.Type == stack.GSONone) && pkt.Size() > int(e.nic.MTU())
}
// handleFragments fragments pkt and calls the handler function on each
@@ -416,11 +416,9 @@ func (e *endpoint) handleFragments(r *stack.Route, gso *stack.GSO, mtu uint32, p
}
n++
if !more {
- break
+ return n, pf.RemainingFragmentCount(), nil
}
}
-
- return n, 0, nil
}
// WritePacket writes a packet to the given destination address and protocol.
@@ -504,21 +502,20 @@ func (e *endpoint) WritePackets(r *stack.Route, gso *stack.GSO, pkts stack.Packe
for pb := pkts.Front(); pb != nil; pb = pb.Next() {
e.addIPHeader(r, pb, params)
if e.packetMustBeFragmented(pb, gso) {
- current := pb
- _, _, err := e.handleFragments(r, gso, e.nic.MTU(), pb, params.Protocol, func(fragPkt *stack.PacketBuffer) *tcpip.Error {
+ // Keep track of the packet that is about to be fragmented so it can be
+ // removed once the fragmentation is done.
+ originalPkt := pb
+ if _, _, err := e.handleFragments(r, gso, e.nic.MTU(), pb, params.Protocol, func(fragPkt *stack.PacketBuffer) *tcpip.Error {
// Modify the packet list in place with the new fragments.
- pkts.InsertAfter(current, fragPkt)
- current = current.Next()
+ pkts.InsertAfter(pb, fragPkt)
+ pb = fragPkt
return nil
- })
- if err != nil {
+ }); err != nil {
r.Stats().IP.OutgoingPacketErrors.IncrementBy(uint64(pkts.Len()))
return 0, err
}
- // The fragmented packet can be released. The rest of the packets can be
- // processed.
- pkts.Remove(pb)
- pb = current
+ // Remove the packet that was just fragmented and process the rest.
+ pkts.Remove(originalPkt)
}
}