Merge release-20210301.0-12-g1cd76d958 (automated)

4 files changed, 51 insertions, 54 deletions

diff --git a/pkg/tcpip/header/checksum.go b/pkg/tcpip/header/checksum.go
index 14a4b2b44..6aa9acfa8 100644
--- a/pkg/tcpip/header/checksum.go
+++ b/pkg/tcpip/header/checksum.go
@@ -186,42 +186,29 @@ func Checksum(buf []byte, initial uint16) uint16 {
 //
 // The initial checksum must have been computed on an even number of bytes.
 func ChecksumVV(vv buffer.VectorisedView, initial uint16) uint16 {
-	return ChecksumVVWithOffset(vv, initial, 0, vv.Size())
+	var c Checksumer
+	for _, v := range vv.Views() {
+		c.Add([]byte(v))
+	}
+	return ChecksumCombine(initial, c.Checksum())
 }
 
-// ChecksumVVWithOffset calculates the checksum (as defined in RFC 1071) of the
-// bytes in the given VectorizedView.
-//
-// The initial checksum must have been computed on an even number of bytes.
-func ChecksumVVWithOffset(vv buffer.VectorisedView, initial uint16, off int, size int) uint16 {
-	odd := false
-	sum := initial
-	for _, v := range vv.Views() {
-		if len(v) == 0 {
-			continue
-		}
-
-		if off >= len(v) {
-			off -= len(v)
-			continue
-		}
-		v = v[off:]
-
-		l := len(v)
-		if l > size {
-			l = size
-		}
-		v = v[:l]
-
-		sum, odd = unrolledCalculateChecksum(v, odd, uint32(sum))
-
-		size -= len(v)
-		if size == 0 {
-			break
-		}
-		off = 0
+// Checksumer calculates checksum defined in RFC 1071.
+type Checksumer struct {
+	sum uint16
+	odd bool
+}
+
+// Add adds b to checksum.
+func (c *Checksumer) Add(b []byte) {
+	if len(b) > 0 {
+		c.sum, c.odd = unrolledCalculateChecksum(b, c.odd, uint32(c.sum))
 	}
-	return sum
+}
+
+// Checksum returns the latest checksum value.
+func (c *Checksumer) Checksum() uint16 {
+	return c.sum
 }
 
 // ChecksumCombine combines the two uint16 to form their checksum. This is done
diff --git a/pkg/tcpip/header/icmpv4.go b/pkg/tcpip/header/icmpv4.go
index f840a4322..91c1c3cd2 100644
--- a/pkg/tcpip/header/icmpv4.go
+++ b/pkg/tcpip/header/icmpv4.go
@@ -18,7 +18,6 @@ import (
 	"encoding/binary"
 
 	"gvisor.dev/gvisor/pkg/tcpip"
-	"gvisor.dev/gvisor/pkg/tcpip/buffer"
 )
 
 // ICMPv4 represents an ICMPv4 header stored in a byte array.
@@ -198,8 +197,8 @@ func (b ICMPv4) SetSequence(sequence uint16) {
 
 // ICMPv4Checksum calculates the ICMP checksum over the provided ICMP header,
 // and payload.
-func ICMPv4Checksum(h ICMPv4, vv buffer.VectorisedView) uint16 {
-	xsum := ChecksumVV(vv, 0)
+func ICMPv4Checksum(h ICMPv4, payloadCsum uint16) uint16 {
+	xsum := payloadCsum
 
 	// h[2:4] is the checksum itself, skip it to avoid checksumming the checksum.
 	xsum = Checksum(h[:2], xsum)
diff --git a/pkg/tcpip/header/icmpv6.go b/pkg/tcpip/header/icmpv6.go
index eca9750ab..668da623a 100644
--- a/pkg/tcpip/header/icmpv6.go
+++ b/pkg/tcpip/header/icmpv6.go
@@ -18,7 +18,6 @@ import (
 	"encoding/binary"
 
 	"gvisor.dev/gvisor/pkg/tcpip"
-	"gvisor.dev/gvisor/pkg/tcpip/buffer"
 )
 
 // ICMPv6 represents an ICMPv6 header stored in a byte array.
@@ -262,12 +261,22 @@ func (b ICMPv6) Payload() []byte {
 	return b[ICMPv6PayloadOffset:]
 }
 
+// ICMPv6ChecksumParams contains parameters to calculate ICMPv6 checksum.
+type ICMPv6ChecksumParams struct {
+	Header      ICMPv6
+	Src         tcpip.Address
+	Dst         tcpip.Address
+	PayloadCsum uint16
+	PayloadLen  int
+}
+
 // ICMPv6Checksum calculates the ICMP checksum over the provided ICMPv6 header,
 // IPv6 src/dst addresses and the payload.
-func ICMPv6Checksum(h ICMPv6, src, dst tcpip.Address, vv buffer.VectorisedView) uint16 {
-	xsum := PseudoHeaderChecksum(ICMPv6ProtocolNumber, src, dst, uint16(len(h)+vv.Size()))
+func ICMPv6Checksum(params ICMPv6ChecksumParams) uint16 {
+	h := params.Header
 
-	xsum = ChecksumVV(vv, xsum)
+	xsum := PseudoHeaderChecksum(ICMPv6ProtocolNumber, params.Src, params.Dst, uint16(len(h)+params.PayloadLen))
+	xsum = ChecksumCombine(xsum, params.PayloadCsum)
 
 	// h[2:4] is the checksum itself, skip it to avoid checksumming the checksum.
 	xsum = Checksum(h[:2], xsum)
diff --git a/pkg/tcpip/header/parse/parse.go b/pkg/tcpip/header/parse/parse.go
index 2042f214a..ebb4b2c1d 100644
--- a/pkg/tcpip/header/parse/parse.go
+++ b/pkg/tcpip/header/parse/parse.go
@@ -41,7 +41,7 @@ func ARP(pkt *stack.PacketBuffer) bool {
 //
 // Returns true if the header was successfully parsed.
 func IPv4(pkt *stack.PacketBuffer) bool {
-	hdr, ok := pkt.Data.PullUp(header.IPv4MinimumSize)
+	hdr, ok := pkt.Data().PullUp(header.IPv4MinimumSize)
 	if !ok {
 		return false
 	}
@@ -62,27 +62,29 @@ func IPv4(pkt *stack.PacketBuffer) bool {
 	ipHdr = header.IPv4(hdr)
 
 	pkt.NetworkProtocolNumber = header.IPv4ProtocolNumber
-	pkt.Data.CapLength(int(ipHdr.TotalLength()) - len(hdr))
+	pkt.Data().CapLength(int(ipHdr.TotalLength()) - len(hdr))
 	return true
 }
 
 // IPv6 parses an IPv6 packet found in pkt.Data and populates pkt's network
 // header with the IPv6 header.
 func IPv6(pkt *stack.PacketBuffer) (proto tcpip.TransportProtocolNumber, fragID uint32, fragOffset uint16, fragMore bool, ok bool) {
-	hdr, ok := pkt.Data.PullUp(header.IPv6MinimumSize)
+	hdr, ok := pkt.Data().PullUp(header.IPv6MinimumSize)
 	if !ok {
 		return 0, 0, 0, false, false
 	}
 	ipHdr := header.IPv6(hdr)
 
-	// dataClone consists of:
+	// Create a VV to parse the packet. We don't plan to modify anything here.
+	// dataVV consists of:
 	// - Any IPv6 header bytes after the first 40 (i.e. extensions).
 	// - The transport header, if present.
 	// - Any other payload data.
 	views := [8]buffer.View{}
-	dataClone := pkt.Data.Clone(views[:])
-	dataClone.TrimFront(header.IPv6MinimumSize)
-	it := header.MakeIPv6PayloadIterator(header.IPv6ExtensionHeaderIdentifier(ipHdr.NextHeader()), dataClone)
+	dataVV := buffer.NewVectorisedView(0, views[:0])
+	dataVV.AppendViews(pkt.Data().Views())
+	dataVV.TrimFront(header.IPv6MinimumSize)
+	it := header.MakeIPv6PayloadIterator(header.IPv6ExtensionHeaderIdentifier(ipHdr.NextHeader()), dataVV)
 
 	// Iterate over the IPv6 extensions to find their length.
 	var nextHdr tcpip.TransportProtocolNumber
@@ -98,7 +100,7 @@ traverseExtensions:
 		// If we exhaust the extension list, the entire packet is the IPv6 header
 		// and (possibly) extensions.
 		if done {
-			extensionsSize = dataClone.Size()
+			extensionsSize = dataVV.Size()
 			break
 		}
 
@@ -110,12 +112,12 @@ traverseExtensions:
 				fragMore = extHdr.More()
 			}
 			rawPayload := it.AsRawHeader(true /* consume */)
-			extensionsSize = dataClone.Size() - rawPayload.Buf.Size()
+			extensionsSize = dataVV.Size() - rawPayload.Buf.Size()
 			break traverseExtensions
 
 		case header.IPv6RawPayloadHeader:
 			// We've found the payload after any extensions.
-			extensionsSize = dataClone.Size() - extHdr.Buf.Size()
+			extensionsSize = dataVV.Size() - extHdr.Buf.Size()
 			nextHdr = tcpip.TransportProtocolNumber(extHdr.Identifier)
 			break traverseExtensions
 
@@ -127,10 +129,10 @@ traverseExtensions:
 	// Put the IPv6 header with extensions in pkt.NetworkHeader().
 	hdr, ok = pkt.NetworkHeader().Consume(header.IPv6MinimumSize + extensionsSize)
 	if !ok {
-		panic(fmt.Sprintf("pkt.Data should have at least %d bytes, but only has %d.", header.IPv6MinimumSize+extensionsSize, pkt.Data.Size()))
+		panic(fmt.Sprintf("pkt.Data should have at least %d bytes, but only has %d.", header.IPv6MinimumSize+extensionsSize, pkt.Data().Size()))
 	}
 	ipHdr = header.IPv6(hdr)
-	pkt.Data.CapLength(int(ipHdr.PayloadLength()))
+	pkt.Data().CapLength(int(ipHdr.PayloadLength()))
 	pkt.NetworkProtocolNumber = header.IPv6ProtocolNumber
 
 	return nextHdr, fragID, fragOffset, fragMore, true
@@ -153,13 +155,13 @@ func UDP(pkt *stack.PacketBuffer) bool {
 func TCP(pkt *stack.PacketBuffer) bool {
 	// TCP header is variable length, peek at it first.
 	hdrLen := header.TCPMinimumSize
-	hdr, ok := pkt.Data.PullUp(hdrLen)
+	hdr, ok := pkt.Data().PullUp(hdrLen)
 	if !ok {
 		return false
 	}
 
 	// If the header has options, pull those up as well.
-	if offset := int(header.TCP(hdr).DataOffset()); offset > header.TCPMinimumSize && offset <= pkt.Data.Size() {
+	if offset := int(header.TCP(hdr).DataOffset()); offset > header.TCPMinimumSize && offset <= pkt.Data().Size() {
 		// TODO(gvisor.dev/issue/2404): Figure out whether to reject this kind of
 		// packets.
 		hdrLen = offset