Add support for IPv6 over GRE [1]. PR kern/80340 includes the

  FreeBSD specific ip_newid() changes NetBSD does not have.
Correct handling of non AF_INET packets passed to bpf [2].

PR:		kern/80340[1], NetBSD PRs 29150[1], 30844[2]
Obtained from:	NetBSD ip_gre.c rev. 1.34,1.35, if_gre.c rev. 1.56
Submitted by:	Gert Doering <gert at greenie.muc.de>[2]
MFC after:	4 days

1 files changed, 19 insertions, 3 deletions

diff --git a/sys/net/if_gre.c b/sys/net/if_gre.c
index 90f54c9..dc7355d 100644
--- a/sys/net/if_gre.c
+++ b/sys/net/if_gre.c
@@ -8,6 +8,8 @@
  * This code is derived from software contributed to The NetBSD Foundation
  * by Heiko W.Rupp <hwr@pilhuhn.de>
  *
+ * IPv6-over-GRE contributed by Gert Doering <gert@greenie.muc.de>
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
@@ -39,7 +41,7 @@
 
 /*
  * Encapsulate L3 protocols into IP
- * See RFC 1701 and 1702 for more details.
+ * See RFC 2784 (successor of RFC 1701 and 1702) for more details.
  * If_gre is compatible with Cisco GRE tunnels, so you can
  * have a NetBSD box as the other end of a tunnel interface of a Cisco
  * router. See gre(4) for more details.
@@ -237,6 +239,8 @@ gre_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
 	struct gre_softc *sc = ifp->if_softc;
 	struct greip *gh;
 	struct ip *ip;
+	u_short ip_id = 0;
+	uint8_t ip_tos = 0;
 	u_int16_t etype = 0;
 	struct mobile_h mob_h;
 	u_int32_t af;
@@ -352,8 +356,16 @@ gre_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
 		switch (dst->sa_family) {
 		case AF_INET:
 			ip = mtod(m, struct ip *);
+			ip_tos = ip->ip_tos;
+			ip_id = ip->ip_id;
 			etype = ETHERTYPE_IP;
 			break;
+#ifdef INET6
+		case AF_INET6:
+			ip_id = ip_newid();
+			etype = ETHERTYPE_IPV6;
+			break;
+#endif
 #ifdef NETATALK
 		case AF_APPLETALK:
 			etype = ETHERTYPE_ATALK;
@@ -393,8 +405,8 @@ gre_output(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
 		((struct ip*)gh)->ip_v = IPPROTO_IPV4;
 		((struct ip*)gh)->ip_hl = (sizeof(struct ip)) >> 2;
 		((struct ip*)gh)->ip_ttl = GRE_TTL;
-		((struct ip*)gh)->ip_tos = ip->ip_tos;
-		((struct ip*)gh)->ip_id = ip->ip_id;
+		((struct ip*)gh)->ip_tos = ip_tos;
+		((struct ip*)gh)->ip_id = ip_id;
 		gh->gi_len = m->m_pkthdr.len;
 	}
 
@@ -473,6 +485,10 @@ gre_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
 		case AF_INET:
 			break;
 #endif
+#ifdef INET6
+		case AF_INET6:
+			break;
+#endif
 		default:
 			error = EAFNOSUPPORT;
 			break;