AF_PACKET support for netstack (aka epsocket).

Like (AF_INET, SOCK_RAW) sockets, AF_PACKET sockets require CAP_NET_RAW. With
runsc, you'll need to pass `--net-raw=true` to enable them.

Binding isn't supported yet.

PiperOrigin-RevId: 275909366

1 files changed, 12 insertions, 9 deletions

diff --git a/pkg/tcpip/link/fdbased/endpoint_test.go b/pkg/tcpip/link/fdbased/endpoint_test.go
index 04406bc9a..59378b96c 100644
--- a/pkg/tcpip/link/fdbased/endpoint_test.go
+++ b/pkg/tcpip/link/fdbased/endpoint_test.go
@@ -43,9 +43,10 @@ const (
 )
 
 type packetInfo struct {
-	raddr    tcpip.LinkAddress
-	proto    tcpip.NetworkProtocolNumber
-	contents buffer.View
+	raddr      tcpip.LinkAddress
+	proto      tcpip.NetworkProtocolNumber
+	contents   buffer.View
+	linkHeader buffer.View
 }
 
 type context struct {
@@ -92,8 +93,8 @@ func (c *context) cleanup() {
 	syscall.Close(c.fds[1])
 }
 
-func (c *context) DeliverNetworkPacket(linkEP stack.LinkEndpoint, remote tcpip.LinkAddress, local tcpip.LinkAddress, protocol tcpip.NetworkProtocolNumber, vv buffer.VectorisedView) {
-	c.ch <- packetInfo{remote, protocol, vv.ToView()}
+func (c *context) DeliverNetworkPacket(linkEP stack.LinkEndpoint, remote tcpip.LinkAddress, local tcpip.LinkAddress, protocol tcpip.NetworkProtocolNumber, vv buffer.VectorisedView, linkHeader buffer.View) {
+	c.ch <- packetInfo{remote, protocol, vv.ToView(), linkHeader}
 }
 
 func TestNoEthernetProperties(t *testing.T) {
@@ -293,11 +294,12 @@ func TestDeliverPacket(t *testing.T) {
 					b[i] = uint8(rand.Intn(256))
 				}
 
+				var hdr header.Ethernet
 				if !eth {
 					// So that it looks like an IPv4 packet.
 					b[0] = 0x40
 				} else {
-					hdr := make(header.Ethernet, header.EthernetMinimumSize)
+					hdr = make(header.Ethernet, header.EthernetMinimumSize)
 					hdr.Encode(&header.EthernetFields{
 						SrcAddr: raddr,
 						DstAddr: laddr,
@@ -315,9 +317,10 @@ func TestDeliverPacket(t *testing.T) {
 				select {
 				case pi := <-c.ch:
 					want := packetInfo{
-						raddr:    raddr,
-						proto:    proto,
-						contents: b,
+						raddr:      raddr,
+						proto:      proto,
+						contents:   b,
+						linkHeader: buffer.View(hdr),
 					}
 					if !eth {
 						want.proto = header.IPv4ProtocolNumber