Introduced Uniform Model for TTL handling.

MPLS TTL is mapped into network layer one as the packet exits the LSP.
Just IPv4 support for now.
Added the relevant sysctls to enable this behaviour.

Input and OK claudio@

4 files changed, 55 insertions, 18 deletions

diff --git a/sys/net/if_mpe.c b/sys/net/if_mpe.c
index 20f21292570..7915f861813 100644
--- a/sys/net/if_mpe.c
+++ b/sys/net/if_mpe.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: if_mpe.c,v 1.12 2008/10/28 01:16:14 michele Exp $ */
+/* $OpenBSD: if_mpe.c,v 1.13 2008/11/01 16:37:55 michele Exp $ */
 
 /*
  * Copyright (c) 2008 Pierre-Yves Ritschard <pyr@spootnik.org>
@@ -69,6 +69,9 @@ LIST_HEAD(, mpe_softc)	mpeif_list;
 struct if_clone	mpe_cloner =
     IF_CLONE_INITIALIZER("mpe", mpe_clone_create, mpe_clone_destroy);
 
+extern int	mpls_mapttl_ip;
+extern int	mpls_mapttl_ip6;
+
 void
 mpeattach(int nmpe)
 {
@@ -277,12 +280,37 @@ mpeioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
 
 void
 mpe_input(struct mbuf *m, struct ifnet *ifp, struct sockaddr_mpls *smpls,
-    u_int32_t ttl)
+    u_int8_t ttl)
 {
-	int		 s;
+	struct ip	*ip;
+	int		 s, hlen;
 
-	/* fixup ttl */
 	/* label -> AF lookup */
+
+	if (mpls_mapttl_ip) {
+		if (m->m_len < sizeof (struct ip) &&
+		    (m = m_pullup(m, sizeof(struct ip))) == NULL)
+			return;
+		ip = mtod(m, struct ip *);
+		hlen = ip->ip_hl << 2;
+		if (m->m_len < hlen) {
+			if ((m = m_pullup(m, hlen)) == NULL)
+				return;
+			ip = mtod(m, struct ip *);
+		}
+
+		if (in_cksum(m, hlen) != 0) {
+			m_free(m);
+			return;
+		}
+
+		/* set IP ttl from MPLS ttl */
+		ip->ip_ttl = ttl;
+
+		/* recalculate checksum */
+		ip->ip_sum = 0;
+		ip->ip_sum = in_cksum(m, hlen);
+	}
 	
 #if NBPFILTER > 0
 	if (ifp && ifp->if_bpf)
@@ -296,13 +324,16 @@ mpe_input(struct mbuf *m, struct ifnet *ifp, struct sockaddr_mpls *smpls,
 
 void
 mpe_input6(struct mbuf *m, struct ifnet *ifp, struct sockaddr_mpls *smpls,
-    u_int32_t ttl)
+    u_int8_t ttl)
 {
 	int		 s;
 
-	/* fixup ttl */
 	/* label -> AF lookup */
-	
+
+	if (mpls_mapttl_ip6) {
+		/* XXX: fixup IPv6 ttl */
+	}
+
 #if NBPFILTER > 0
 	if (ifp && ifp->if_bpf)
 		bpf_mtap(ifp->if_bpf, m, BPF_DIRECTION_OUT);
diff --git a/sys/netmpls/mpls.h b/sys/netmpls/mpls.h
index 7b4b464d642..03017c9b63c 100644
--- a/sys/netmpls/mpls.h
+++ b/sys/netmpls/mpls.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: mpls.h,v 1.13 2008/10/28 01:16:14 michele Exp $	*/
+/*	$OpenBSD: mpls.h,v 1.14 2008/11/01 16:37:55 michele Exp $	*/
 
 /*
  * Copyright (C) 1999, 2000 and 2001 AYAME Project, WIDE Project.
@@ -116,7 +116,9 @@ struct sockaddr_mpls {
 #define	MPLSCTL_DEFTTL			2
 #define MPLSCTL_IFQUEUE			3
 #define	MPLSCTL_MAXINKLOOP		4
-#define MPLSCTL_MAXID			5
+#define MPLSCTL_MAPTTL_IP		5
+#define MPLSCTL_MAPTTL_IP6		6
+#define MPLSCTL_MAXID			7	
 
 #define MPLSCTL_NAMES { \
 	{ 0, 0 }, \
@@ -124,6 +126,8 @@ struct sockaddr_mpls {
 	{ "ttl", CTLTYPE_INT }, \
 	{ "ifq", CTLTYPE_NODE },\
 	{ "maxloop_inkernel", CTLTYPE_INT }, \
+	{ "mapttl_ip", CTLTYPE_INT }, \
+	{ "mapttl_ip6", CTLTYPE_INT }, \
 }
 
 #define MPLSCTL_VARS { \
@@ -132,6 +136,8 @@ struct sockaddr_mpls {
 	&mpls_defttl, \
 	0, \
 	&mpls_inkloop, \
+	&mpls_mapttl_ip, \
+	&mpls_mapttl_ip6, \
 }
 
 #endif
@@ -151,9 +157,9 @@ struct mpe_softc {
 #define MPE_MTU_MAX	8192
 
 void	mpe_input(struct mbuf *, struct ifnet *, struct sockaddr_mpls *,
-	    u_int32_t);
+	    u_int8_t);
 void	mpe_input6(struct mbuf *, struct ifnet *, struct sockaddr_mpls *,
-	    u_int32_t);
+	    u_int8_t);
 
 extern int mpls_raw_usrreq(struct socket *, int, struct mbuf *,
 			struct mbuf *, struct mbuf *, struct proc *);
diff --git a/sys/netmpls/mpls_input.c b/sys/netmpls/mpls_input.c
index 39ff4c621b6..e267fd9ea1b 100644
--- a/sys/netmpls/mpls_input.c
+++ b/sys/netmpls/mpls_input.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: mpls_input.c,v 1.14 2008/10/14 20:43:33 michele Exp $	*/
+/*	$OpenBSD: mpls_input.c,v 1.15 2008/11/01 16:37:55 michele Exp $	*/
 
 /*
  * Copyright (c) 2008 Claudio Jeker <claudio@openbsd.org>
@@ -71,9 +71,9 @@ mpls_input(struct mbuf *m)
 	struct ifnet *ifp = m->m_pkthdr.rcvif;
 	struct sockaddr_mpls *smpls;
 	struct sockaddr_mpls sa_mpls;
-	struct shim_hdr *shim;
+	struct shim_hdr	*shim;
 	struct rtentry *rt = NULL;
-	u_int32_t ttl;
+	u_int8_t ttl;
 	int i, hasbos;
 
 	if (!mpls_enable) {
@@ -111,7 +111,7 @@ mpls_input(struct mbuf *m)
 		m_freem(m);
 		return;
 	}
-	ttl = htonl(ttl - 1);
+	ttl--;
 
 	for (i = 0; i < mpls_inkloop; i++) {
 		bzero(&sa_mpls, sizeof(sa_mpls));
@@ -219,7 +219,7 @@ mpls_input(struct mbuf *m)
 	}
 
 	/* write back TTL */
-	shim->shim_label = (shim->shim_label & ~MPLS_TTL_MASK) | ttl;
+	shim->shim_label = (shim->shim_label & ~MPLS_TTL_MASK) | htonl(ttl);
 
 #ifdef MPLS_DEBUG
 	printf("MPLS: sending on %s outlabel %x dst af %d in %d out %d\n",
diff --git a/sys/netmpls/mpls_raw.c b/sys/netmpls/mpls_raw.c
index 1f3257cb7ab..2350afe652d 100644
--- a/sys/netmpls/mpls_raw.c
+++ b/sys/netmpls/mpls_raw.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: mpls_raw.c,v 1.3 2008/05/23 16:03:03 thib Exp $	*/
+/*	$OpenBSD: mpls_raw.c,v 1.4 2008/11/01 16:37:55 michele Exp $	*/
 
 /*
  * Copyright (C) 1999, 2000 and 2001 AYAME Project, WIDE Project.
@@ -129,7 +129,7 @@ mpls_sysctl(int *name, u_int namelen, void *oldp, size_t *oldlenp, void *newp,
     size_t newlen)
 {
 	if (name[0] >= MPLSCTL_MAXID)
-		return EOPNOTSUPP;
+		return (EOPNOTSUPP);
 
 	/* Almost all sysctl names at this level are terminal. */
 	if (namelen != 1 && name[0] != MPLSCTL_IFQUEUE)