Ping support via IPv4 raw sockets.

Broadly, this change:
* Enables sockets to be created via `socket(AF_INET, SOCK_RAW, IPPROTO_ICMP)`.
* Passes the network-layer (IP) header up the stack to the transport endpoint,
  which can pass it up to the socket layer. This allows a raw socket to return
  the entire IP packet to users.
* Adds functions to stack.TransportProtocol, stack.Stack, stack.transportDemuxer
  that enable incoming packets to be delivered to raw endpoints. New raw sockets
  of other protocols (not ICMP) just need to register with the stack.
* Enables ping.endpoint to return IP headers when created via SOCK_RAW.

PiperOrigin-RevId: 235993280
Change-Id: I60ed994f5ff18b2cbd79f063a7fdf15d093d845a

1 files changed, 4 insertions, 4 deletions

diff --git a/pkg/tcpip/stack/nic.go b/pkg/tcpip/stack/nic.go
index 2278fbf65..79f845225 100644
--- a/pkg/tcpip/stack/nic.go
+++ b/pkg/tcpip/stack/nic.go
@@ -505,7 +505,7 @@ func (n *NIC) getRef(protocol tcpip.NetworkProtocolNumber, dst tcpip.Address) *r
 
 // DeliverTransportPacket delivers the packets to the appropriate transport
 // protocol endpoint.
-func (n *NIC) DeliverTransportPacket(r *Route, protocol tcpip.TransportProtocolNumber, vv buffer.VectorisedView) {
+func (n *NIC) DeliverTransportPacket(r *Route, protocol tcpip.TransportProtocolNumber, netHeader buffer.View, vv buffer.VectorisedView) {
 	state, ok := n.stack.transportProtocols[protocol]
 	if !ok {
 		n.stack.stats.UnknownProtocolRcvdPackets.Increment()
@@ -525,16 +525,16 @@ func (n *NIC) DeliverTransportPacket(r *Route, protocol tcpip.TransportProtocolN
 	}
 
 	id := TransportEndpointID{dstPort, r.LocalAddress, srcPort, r.RemoteAddress}
-	if n.demux.deliverPacket(r, protocol, vv, id) {
+	if n.demux.deliverPacket(r, protocol, netHeader, vv, id) {
 		return
 	}
-	if n.stack.demux.deliverPacket(r, protocol, vv, id) {
+	if n.stack.demux.deliverPacket(r, protocol, netHeader, vv, id) {
 		return
 	}
 
 	// Try to deliver to per-stack default handler.
 	if state.defaultHandler != nil {
-		if state.defaultHandler(r, id, vv) {
+		if state.defaultHandler(r, id, netHeader, vv) {
 			return
 		}
 	}