diff options
| -rw-r--r-- | pkg/tcpip/network/fragmentation/fragmentation.go | 16 | ||||
| -rw-r--r-- | pkg/tcpip/network/fragmentation/reassembler.go | 10 | ||||
| -rw-r--r-- | pkg/tcpip/network/ipv4/ipv4.go | 8 |
3 files changed, 24 insertions, 10 deletions
diff --git a/pkg/tcpip/network/fragmentation/fragmentation.go b/pkg/tcpip/network/fragmentation/fragmentation.go index 1628a82be..6da5238ec 100644 --- a/pkg/tcpip/network/fragmentation/fragmentation.go +++ b/pkg/tcpip/network/fragmentation/fragmentation.go @@ -17,6 +17,7 @@ package fragmentation import ( + "fmt" "log" "sync" "time" @@ -82,7 +83,7 @@ func NewFragmentation(highMemoryLimit, lowMemoryLimit int, reassemblingTimeout t // Process processes an incoming fragment belonging to an ID // and returns a complete packet when all the packets belonging to that ID have been received. -func (f *Fragmentation) Process(id uint32, first, last uint16, more bool, vv buffer.VectorisedView) (buffer.VectorisedView, bool) { +func (f *Fragmentation) Process(id uint32, first, last uint16, more bool, vv buffer.VectorisedView) (buffer.VectorisedView, bool, error) { f.mu.Lock() r, ok := f.reassemblers[id] if ok && r.tooOld(f.timeout) { @@ -97,8 +98,15 @@ func (f *Fragmentation) Process(id uint32, first, last uint16, more bool, vv buf } f.mu.Unlock() - res, done, consumed := r.process(first, last, more, vv) - + res, done, consumed, err := r.process(first, last, more, vv) + if err != nil { + // We probably got an invalid sequence of fragments. Just + // discard the reassembler and move on. + f.mu.Lock() + f.release(r) + f.mu.Unlock() + return buffer.VectorisedView{}, false, fmt.Errorf("fragmentation processing error: %v", err) + } f.mu.Lock() f.size += consumed if done { @@ -114,7 +122,7 @@ func (f *Fragmentation) Process(id uint32, first, last uint16, more bool, vv buf } } f.mu.Unlock() - return res, done + return res, done, nil } func (f *Fragmentation) release(r *reassembler) { diff --git a/pkg/tcpip/network/fragmentation/reassembler.go b/pkg/tcpip/network/fragmentation/reassembler.go index 8037f734b..9e002e396 100644 --- a/pkg/tcpip/network/fragmentation/reassembler.go +++ b/pkg/tcpip/network/fragmentation/reassembler.go @@ -78,7 +78,7 @@ func (r *reassembler) updateHoles(first, last uint16, more bool) bool { return used } -func (r *reassembler) process(first, last uint16, more bool, vv buffer.VectorisedView) (buffer.VectorisedView, bool, int) { +func (r *reassembler) process(first, last uint16, more bool, vv buffer.VectorisedView) (buffer.VectorisedView, bool, int, error) { r.mu.Lock() defer r.mu.Unlock() consumed := 0 @@ -86,7 +86,7 @@ func (r *reassembler) process(first, last uint16, more bool, vv buffer.Vectorise // A concurrent goroutine might have already reassembled // the packet and emptied the heap while this goroutine // was waiting on the mutex. We don't have to do anything in this case. - return buffer.VectorisedView{}, false, consumed + return buffer.VectorisedView{}, false, consumed, nil } if r.updateHoles(first, last, more) { // We store the incoming packet only if it filled some holes. @@ -96,13 +96,13 @@ func (r *reassembler) process(first, last uint16, more bool, vv buffer.Vectorise } // Check if all the holes have been deleted and we are ready to reassamble. if r.deleted < len(r.holes) { - return buffer.VectorisedView{}, false, consumed + return buffer.VectorisedView{}, false, consumed, nil } res, err := r.heap.reassemble() if err != nil { - panic(fmt.Sprintf("reassemble failed with: %v. There is probably a bug in the code handling the holes.", err)) + return buffer.VectorisedView{}, false, consumed, fmt.Errorf("fragment reassembly failed: %v", err) } - return res, true, consumed + return res, true, consumed, nil } func (r *reassembler) tooOld(timeout time.Duration) bool { diff --git a/pkg/tcpip/network/ipv4/ipv4.go b/pkg/tcpip/network/ipv4/ipv4.go index df1a08113..5cd895ff0 100644 --- a/pkg/tcpip/network/ipv4/ipv4.go +++ b/pkg/tcpip/network/ipv4/ipv4.go @@ -326,7 +326,13 @@ func (e *endpoint) HandlePacket(r *stack.Route, vv buffer.VectorisedView) { return } var ready bool - vv, ready = e.fragmentation.Process(hash.IPv4FragmentHash(h), h.FragmentOffset(), last, more, vv) + var err error + vv, ready, err = e.fragmentation.Process(hash.IPv4FragmentHash(h), h.FragmentOffset(), last, more, vv) + if err != nil { + r.Stats().IP.MalformedPacketsReceived.Increment() + r.Stats().IP.MalformedFragmentsReceived.Increment() + return + } if !ready { return } |