Merge release-20210125.0-36-g825c185dc (automated)

2 files changed, 35 insertions, 36 deletions

diff --git a/pkg/tcpip/network/fragmentation/fragmentation.go b/pkg/tcpip/network/fragmentation/fragmentation.go
index 1af87d713..243738951 100644
--- a/pkg/tcpip/network/fragmentation/fragmentation.go
+++ b/pkg/tcpip/network/fragmentation/fragmentation.go
@@ -84,7 +84,7 @@ type Fragmentation struct {
 	lowLimit       int
 	reassemblers   map[FragmentID]*reassembler
 	rList          reassemblerList
-	size           int
+	memSize        int
 	timeout        time.Duration
 	blockSize      uint16
 	clock          tcpip.Clock
@@ -156,22 +156,22 @@ func NewFragmentation(blockSize uint16, highMemoryLimit, lowMemoryLimit int, rea
 // the protocol to identify a fragment.
 func (f *Fragmentation) Process(
 	id FragmentID, first, last uint16, more bool, proto uint8, pkt *stack.PacketBuffer) (
-	buffer.VectorisedView, uint8, bool, error) {
+	*stack.PacketBuffer, uint8, bool, error) {
 	if first > last {
-		return buffer.VectorisedView{}, 0, false, fmt.Errorf("first=%d is greater than last=%d: %w", first, last, ErrInvalidArgs)
+		return nil, 0, false, fmt.Errorf("first=%d is greater than last=%d: %w", first, last, ErrInvalidArgs)
 	}
 
 	if first%f.blockSize != 0 {
-		return buffer.VectorisedView{}, 0, false, fmt.Errorf("first=%d is not a multiple of block size=%d: %w", first, f.blockSize, ErrInvalidArgs)
+		return nil, 0, false, fmt.Errorf("first=%d is not a multiple of block size=%d: %w", first, f.blockSize, ErrInvalidArgs)
 	}
 
 	fragmentSize := last - first + 1
 	if more && fragmentSize%f.blockSize != 0 {
-		return buffer.VectorisedView{}, 0, false, fmt.Errorf("fragment size=%d bytes is not a multiple of block size=%d on non-final fragment: %w", fragmentSize, f.blockSize, ErrInvalidArgs)
+		return nil, 0, false, fmt.Errorf("fragment size=%d bytes is not a multiple of block size=%d on non-final fragment: %w", fragmentSize, f.blockSize, ErrInvalidArgs)
 	}
 
 	if l := pkt.Data.Size(); l != int(fragmentSize) {
-		return buffer.VectorisedView{}, 0, false, fmt.Errorf("got fragment size=%d bytes not equal to the expected fragment size=%d bytes (first=%d last=%d): %w", l, fragmentSize, first, last, ErrInvalidArgs)
+		return nil, 0, false, fmt.Errorf("got fragment size=%d bytes not equal to the expected fragment size=%d bytes (first=%d last=%d): %w", l, fragmentSize, first, last, ErrInvalidArgs)
 	}
 
 	f.mu.Lock()
@@ -190,24 +190,24 @@ func (f *Fragmentation) Process(
 	}
 	f.mu.Unlock()
 
-	res, firstFragmentProto, done, consumed, err := r.process(first, last, more, proto, pkt)
+	resPkt, firstFragmentProto, done, memConsumed, err := r.process(first, last, more, proto, pkt)
 	if err != nil {
 		// We probably got an invalid sequence of fragments. Just
 		// discard the reassembler and move on.
 		f.mu.Lock()
 		f.release(r, false /* timedOut */)
 		f.mu.Unlock()
-		return buffer.VectorisedView{}, 0, false, fmt.Errorf("fragmentation processing error: %w", err)
+		return nil, 0, false, fmt.Errorf("fragmentation processing error: %w", err)
 	}
 	f.mu.Lock()
-	f.size += consumed
+	f.memSize += memConsumed
 	if done {
 		f.release(r, false /* timedOut */)
 	}
 	// Evict reassemblers if we are consuming more memory than highLimit until
 	// we reach lowLimit.
-	if f.size > f.highLimit {
-		for f.size > f.lowLimit {
+	if f.memSize > f.highLimit {
+		for f.memSize > f.lowLimit {
 			tail := f.rList.Back()
 			if tail == nil {
 				break
@@ -216,7 +216,7 @@ func (f *Fragmentation) Process(
 		}
 	}
 	f.mu.Unlock()
-	return res, firstFragmentProto, done, nil
+	return resPkt, firstFragmentProto, done, nil
 }
 
 func (f *Fragmentation) release(r *reassembler, timedOut bool) {
@@ -228,10 +228,10 @@ func (f *Fragmentation) release(r *reassembler, timedOut bool) {
 
 	delete(f.reassemblers, r.id)
 	f.rList.Remove(r)
-	f.size -= r.size
-	if f.size < 0 {
-		log.Printf("memory counter < 0 (%d), this is an accounting bug that requires investigation", f.size)
-		f.size = 0
+	f.memSize -= r.memSize
+	if f.memSize < 0 {
+		log.Printf("memory counter < 0 (%d), this is an accounting bug that requires investigation", f.memSize)
+		f.memSize = 0
 	}
 
 	if h := f.timeoutHandler; timedOut && h != nil {
diff --git a/pkg/tcpip/network/fragmentation/reassembler.go b/pkg/tcpip/network/fragmentation/reassembler.go
index 9b20bb1d8..933d63d32 100644
--- a/pkg/tcpip/network/fragmentation/reassembler.go
+++ b/pkg/tcpip/network/fragmentation/reassembler.go
@@ -20,7 +20,6 @@ import (
 
 	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/tcpip"
-	"gvisor.dev/gvisor/pkg/tcpip/buffer"
 	"gvisor.dev/gvisor/pkg/tcpip/stack"
 )
 
@@ -29,13 +28,15 @@ type hole struct {
 	last   uint16
 	filled bool
 	final  bool
-	data   buffer.View
+	// pkt is the fragment packet if hole is filled. We keep the whole pkt rather
+	// than the fragmented payload to prevent binding to specific buffer types.
+	pkt *stack.PacketBuffer
 }
 
 type reassembler struct {
 	reassemblerEntry
 	id           FragmentID
-	size         int
+	memSize      int
 	proto        uint8
 	mu           sync.Mutex
 	holes        []hole
@@ -59,18 +60,18 @@ func newReassembler(id FragmentID, clock tcpip.Clock) *reassembler {
 	return r
 }
 
-func (r *reassembler) process(first, last uint16, more bool, proto uint8, pkt *stack.PacketBuffer) (buffer.VectorisedView, uint8, bool, int, error) {
+func (r *reassembler) process(first, last uint16, more bool, proto uint8, pkt *stack.PacketBuffer) (*stack.PacketBuffer, uint8, bool, int, error) {
 	r.mu.Lock()
 	defer r.mu.Unlock()
 	if r.done {
 		// 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{}, 0, false, 0, nil
+		return nil, 0, false, 0, nil
 	}
 
 	var holeFound bool
-	var consumed int
+	var memConsumed int
 	for i := range r.holes {
 		currentHole := &r.holes[i]
 
@@ -90,12 +91,12 @@ func (r *reassembler) process(first, last uint16, more bool, proto uint8, pkt *s
 		// https://github.com/torvalds/linux/blob/38525c6/net/ipv4/inet_fragment.c#L349
 		if first < currentHole.first || currentHole.last < last {
 			// Incoming fragment only partially fits in the free hole.
-			return buffer.VectorisedView{}, 0, false, 0, ErrFragmentOverlap
+			return nil, 0, false, 0, ErrFragmentOverlap
 		}
 		if !more {
 			if !currentHole.final || currentHole.filled && currentHole.last != last {
 				// We have another final fragment, which does not perfectly overlap.
-				return buffer.VectorisedView{}, 0, false, 0, ErrFragmentConflict
+				return nil, 0, false, 0, ErrFragmentConflict
 			}
 		}
 
@@ -124,16 +125,15 @@ func (r *reassembler) process(first, last uint16, more bool, proto uint8, pkt *s
 			})
 			currentHole.final = false
 		}
-		v := pkt.Data.ToOwnedView()
-		consumed = v.Size()
-		r.size += consumed
+		memConsumed = pkt.MemSize()
+		r.memSize += memConsumed
 		// Update the current hole to precisely match the incoming fragment.
 		r.holes[i] = hole{
 			first:  first,
 			last:   last,
 			filled: true,
 			final:  currentHole.final,
-			data:   v,
+			pkt:    pkt,
 		}
 		r.filled++
 		// For IPv6, it is possible to have different Protocol values between
@@ -153,25 +153,24 @@ func (r *reassembler) process(first, last uint16, more bool, proto uint8, pkt *s
 	}
 	if !holeFound {
 		// Incoming fragment is beyond end.
-		return buffer.VectorisedView{}, 0, false, 0, ErrFragmentConflict
+		return nil, 0, false, 0, ErrFragmentConflict
 	}
 
 	// Check if all the holes have been filled and we are ready to reassemble.
 	if r.filled < len(r.holes) {
-		return buffer.VectorisedView{}, 0, false, consumed, nil
+		return nil, 0, false, memConsumed, nil
 	}
 
 	sort.Slice(r.holes, func(i, j int) bool {
 		return r.holes[i].first < r.holes[j].first
 	})
 
-	var size int
-	views := make([]buffer.View, 0, len(r.holes))
-	for _, hole := range r.holes {
-		views = append(views, hole.data)
-		size += hole.data.Size()
+	resPkt := r.holes[0].pkt
+	for i := 1; i < len(r.holes); i++ {
+		fragPkt := r.holes[i].pkt
+		fragPkt.Data.ReadToVV(&resPkt.Data, fragPkt.Data.Size())
 	}
-	return buffer.NewVectorisedView(size, views), r.proto, true, consumed, nil
+	return resPkt, r.proto, true, memConsumed, nil
 }
 
 func (r *reassembler) checkDoneOrMark() bool {