OpenBSD-4.6/sys/netmpls/mpls_input.c
/* $OpenBSD: mpls_input.c,v 1.21 2009/04/29 19:26:52 michele Exp $ */
/*
* Copyright (c) 2008 Claudio Jeker <claudio@openbsd.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include "mpe.h"
#include <sys/param.h>
#include <sys/mbuf.h>
#include <sys/systm.h>
#include <sys/socket.h>
#include <net/if.h>
#include <net/if_types.h>
#include <net/netisr.h>
#include <net/route.h>
#ifdef INET
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#endif
#ifdef INET6
#include <netinet/ip6.h>
#ifndef INET
#include <netinet/in.h>
#endif
#endif /* INET6 */
#include <netmpls/mpls.h>
struct ifqueue mplsintrq;
int mplsqmaxlen = IFQ_MAXLEN;
extern int mpls_inkloop;
#ifdef MPLS_DEBUG
#define MPLS_LABEL_GET(l) ((ntohl((l) & MPLS_LABEL_MASK)) >> MPLS_LABEL_OFFSET)
#define MPLS_TTL_GET(l) (ntohl((l) & MPLS_TTL_MASK))
#endif
extern int mpls_mapttl_ip;
extern int mpls_mapttl_ip6;
void
mpls_init(void)
{
mplsintrq.ifq_maxlen = mplsqmaxlen;
}
void
mplsintr(void)
{
struct mbuf *m;
int s;
for (;;) {
/* Get next datagram of input queue */
s = splnet();
IF_DEQUEUE(&mplsintrq, m);
splx(s);
if (m == NULL)
return;
#ifdef DIAGNOSTIC
if ((m->m_flags & M_PKTHDR) == 0)
panic("ipintr no HDR");
#endif
mpls_input(m);
}
}
void
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 rtentry *rt = NULL;
struct rt_mpls *rt_mpls;
u_int8_t ttl;
int i, hasbos;
if (!mpls_enable) {
m_freem(m);
return;
}
/* drop all broadcast and multicast packets */
if (m->m_flags & (M_BCAST | M_MCAST)) {
m_freem(m);
return;
}
if (m->m_len < sizeof(*shim))
if ((m = m_pullup(m, sizeof(*shim))) == NULL)
return;
shim = mtod(m, struct shim_hdr *);
#ifdef MPLS_DEBUG
printf("mpls_input: iface %s label=%d, ttl=%d BoS %d\n",
ifp->if_xname, MPLS_LABEL_GET(shim->shim_label),
MPLS_TTL_GET(shim->shim_label),
MPLS_BOS_ISSET(shim->shim_label));
#endif /* MPLS_DEBUG */
/* check and decrement TTL */
ttl = ntohl(shim->shim_label & MPLS_TTL_MASK);
if (ttl <= 1) {
/* TTL exceeded */
/*
* XXX if possible hand packet up to network layer so that an
* ICMP TTL exceeded can be sent back.
*/
m_freem(m);
return;
}
ttl--;
for (i = 0; i < mpls_inkloop; i++) {
bzero(&sa_mpls, sizeof(sa_mpls));
smpls = &sa_mpls;
smpls->smpls_family = AF_MPLS;
smpls->smpls_len = sizeof(*smpls);
smpls->smpls_label = shim->shim_label & MPLS_LABEL_MASK;
#ifdef MPLS_DEBUG
printf("smpls af %d len %d in_label %d in_ifindex %d\n",
smpls->smpls_family, smpls->smpls_len,
MPLS_LABEL_GET(smpls->smpls_label),
ifp->if_index);
#endif
if (ntohl(smpls->smpls_label) < MPLS_LABEL_RESERVED_MAX) {
hasbos = MPLS_BOS_ISSET(shim->shim_label);
m = mpls_shim_pop(m);
shim = mtod(m, struct shim_hdr *);
switch (ntohl(smpls->smpls_label)) {
case MPLS_LABEL_IPV4NULL:
if (hasbos) {
mpls_ip_input(m, ttl);
goto done;
} else
continue;
case MPLS_LABEL_IPV6NULL:
if (hasbos) {
mpls_ip6_input(m, ttl);
goto done;
} else
continue;
default:
m_freem(m);
goto done;
}
/* Other cases are not handled for now */
}
rt = rtalloc1(smplstosa(smpls), 1, 0);
if (rt == NULL) {
/* no entry for this label */
#ifdef MPLS_DEBUG
printf("MPLS_DEBUG: label not found\n");
#endif
m_freem(m);
goto done;
}
rt->rt_use++;
smpls = satosmpls(rt_key(rt));
rt_mpls = (struct rt_mpls *)rt->rt_llinfo;
if (rt_mpls == NULL || (rt->rt_flags & RTF_MPLS) == 0) {
#ifdef MPLS_DEBUG
printf("MPLS_DEBUG: no MPLS information "
"attached\n");
#endif
m_freem(m);
goto done;
}
if (rt_mpls->mpls_operation == MPLS_OP_LOCAL) {
/* Packet is for us */
hasbos = MPLS_BOS_ISSET(shim->shim_label);
if (!hasbos) {
#ifdef MPLS_DEBUG
printf("MPLS_DEBUG: packet malformed\n");
#endif
m_freem(m);
goto done;
}
m = mpls_shim_pop(m);
if (!rt->rt_gateway) {
#ifdef MPLS_DEBUG
printf("MPLS_DEBUG: no layer 3 informations "
"attached\n");
#endif
m_freem(m);
goto done;
}
switch(rt->rt_gateway->sa_family) {
case AF_INET:
mpls_ip_input(m, ttl);
break;
case AF_INET6:
mpls_ip6_input(m, ttl);
break;
default:
m_freem(m);
}
goto done;
}
if (rt_mpls->mpls_operation & MPLS_OP_POP) {
hasbos = MPLS_BOS_ISSET(shim->shim_label);
if (hasbos) {
m = mpls_shim_pop(m);
#if NMPE > 0
if (rt->rt_ifp->if_type == IFT_MPLS) {
mpe_input(m, rt->rt_ifp, smpls, ttl);
goto done;
}
#endif
/* last label but we have no clue so drop */
m_freem(m);
goto done;
}
}
/* refetch label */
shim = mtod(m, struct shim_hdr *);
ifp = rt->rt_ifp;
if (ifp != NULL)
break;
RTFREE(rt);
rt = NULL;
}
if (rt == NULL) {
m_freem(m);
goto done;
}
/* write back 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",
ifp->if_xname, ntohl(shim->shim_label), smpls->smpls_family,
MPLS_LABEL_GET(smpls->smpls_label),
MPLS_LABEL_GET(rt_mpls->mpls_label));
#endif
(*ifp->if_output)(ifp, m, smplstosa(smpls), rt);
done:
if (rt)
RTFREE(rt);
}
void
mpls_ip_input(struct mbuf *m, u_int8_t ttl)
{
struct ip *ip;
int s, hlen;
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);
}
s = splnet();
IF_ENQUEUE(&ipintrq, m);
schednetisr(NETISR_IP);
splx(s);
}
void
mpls_ip6_input(struct mbuf *m, u_int8_t ttl)
{
struct ip6_hdr *ip6hdr;
int s;
if (mpls_mapttl_ip6) {
if (m->m_len < sizeof (struct ip6_hdr) &&
(m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL)
return;
ip6hdr = mtod(m, struct ip6_hdr *);
/* set IPv6 ttl from MPLS ttl */
ip6hdr->ip6_hlim = ttl;
}
s = splnet();
IF_ENQUEUE(&ip6intrq, m);
schednetisr(NETISR_IPV6);
splx(s);
}