Add RFC 3378 EtherIP support. This change makes it possible to add gif

interfaces to bridges, which will then send and receive IP protocol 97 packets.
Packets are Ethernet frames with an EtherIP header prepended.

Obtained from:	NetBSD
MFC after:	2 weeks

1 files changed, 67 insertions, 4 deletions

diff --git a/sys/net/if_gif.c b/sys/net/if_gif.c
index c946a1c..940e00e 100644
--- a/sys/net/if_gif.c
+++ b/sys/net/if_gif.c
@@ -80,6 +80,8 @@
 #endif /* INET6 */
 
 #include <netinet/ip_encap.h>
+#include <net/ethernet.h>
+#include <net/if_bridgevar.h>
 #include <net/if_gif.h>
 
 #include <net/net_osdep.h>
@@ -99,6 +101,7 @@ void	(*ng_gif_input_orphan_p)(struct ifnet *ifp, struct mbuf *m, int af);
 void	(*ng_gif_attach_p)(struct ifnet *ifp);
 void	(*ng_gif_detach_p)(struct ifnet *ifp);
 
+static void	gif_start(struct ifnet *);
 static int	gif_clone_create(struct if_clone *, int);
 static void	gif_clone_destroy(struct ifnet *);
 
@@ -177,6 +180,7 @@ gifattach0(sc)
 	GIF2IFP(sc)->if_flags  |= IFF_LINK2;
 #endif
 	GIF2IFP(sc)->if_ioctl  = gif_ioctl;
+	GIF2IFP(sc)->if_start  = gif_start;
 	GIF2IFP(sc)->if_output = gif_output;
 	GIF2IFP(sc)->if_snd.ifq_maxlen = IFQ_MAXLEN;
 	if_attach(GIF2IFP(sc));
@@ -289,6 +293,9 @@ gif_encapcheck(m, off, proto, arg)
 	case IPPROTO_IPV6:
 		break;
 #endif
+	case IPPROTO_ETHERIP:
+		break;
+
 	default:
 		return 0;
 	}
@@ -321,6 +328,28 @@ gif_encapcheck(m, off, proto, arg)
 	}
 }
 
+static void
+gif_start(struct ifnet *ifp)
+{
+	struct gif_softc *sc;
+	struct mbuf *m;
+
+	sc = ifp->if_softc;
+
+	ifp->if_drv_flags |= IFF_DRV_OACTIVE;
+	for (;;) {
+		IFQ_DEQUEUE(&ifp->if_snd, m);
+		if (m == 0)
+			break;
+
+		gif_output(ifp, m, sc->gif_pdst, NULL);
+
+	}
+	ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
+
+	return;
+}
+
 int
 gif_output(ifp, m, dst, rt)
 	struct ifnet *ifp;
@@ -395,13 +424,17 @@ gif_output(ifp, m, dst, rt)
 		dst->sa_family = af;
 	}
 
+	af = dst->sa_family;
 	if (ifp->if_bpf) {
-		af = dst->sa_family;
 		bpf_mtap2(ifp->if_bpf, &af, sizeof(af), m);
 	}
 	ifp->if_opackets++;	
 	ifp->if_obytes += m->m_pkthdr.len;
 
+	/* override to IPPROTO_ETHERIP for bridged traffic */
+	if (ifp->if_bridge)
+		af = AF_LINK;
+
 	/* inner AF-specific encapsulation */
 
 	/* XXX should we check if our outer source is legal? */
@@ -410,12 +443,12 @@ gif_output(ifp, m, dst, rt)
 	switch (sc->gif_psrc->sa_family) {
 #ifdef INET
 	case AF_INET:
-		error = in_gif_output(ifp, dst->sa_family, m);
+		error = in_gif_output(ifp, af, m);
 		break;
 #endif
 #ifdef INET6
 	case AF_INET6:
-		error = in6_gif_output(ifp, dst->sa_family, m);
+		error = in6_gif_output(ifp, af, m);
 		break;
 #endif
 	default:
@@ -436,7 +469,8 @@ gif_input(m, af, ifp)
 	int af;
 	struct ifnet *ifp;
 {
-	int isr;
+	int isr, n;
+	struct etherip_header *eip;
 
 	if (ifp == NULL) {
 		/* just in case */
@@ -483,6 +517,35 @@ gif_input(m, af, ifp)
 		isr = NETISR_IPV6;
 		break;
 #endif
+	case AF_LINK:
+		n = sizeof(struct etherip_header) + sizeof(struct ether_header);
+		if (n > m->m_len) {
+			m = m_pullup(m, n);
+			if (m == NULL) {
+				ifp->if_ierrors++;
+				return;
+			}
+		}
+
+		eip = mtod(m, struct etherip_header *);
+ 		if (eip->eip_ver !=
+		    (ETHERIP_VERSION & ETHERIP_VER_VERS_MASK)) {
+			/* discard unknown versions */
+			m_freem(m);
+			return;
+		}
+		m_adj(m, sizeof(struct etherip_header));
+
+		m->m_flags &= ~(M_BCAST|M_MCAST);
+		m->m_pkthdr.rcvif = ifp;
+
+		if (ifp->if_bridge)
+			BRIDGE_INPUT(ifp, m);
+		
+		if (m != NULL)
+			m_freem(m);
+		return;
+
 	default:
 		if (ng_gif_input_orphan_p != NULL)
 			(*ng_gif_input_orphan_p)(ifp, m, af);