1 /* 2 * Copyright (c) 2007 The DragonFly Project. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in 12 * the documentation and/or other materials provided with the 13 * distribution. 14 * 3. Neither the name of The DragonFly Project nor the names of its 15 * contributors may be used to endorse or promote products derived 16 * from this software without specific, prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 21 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 22 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 23 * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, 24 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 25 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED 26 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 27 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 28 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 * 31 * $DragonFly: src/sys/netproto/mpls/mpls_input.c,v 1.2 2008/08/05 15:11:32 nant Exp $ 32 */ 33 34 #include <sys/globaldata.h> 35 #include <sys/kernel.h> 36 #include <sys/mbuf.h> 37 #include <sys/param.h> 38 #include <sys/sysctl.h> 39 #include <sys/systm.h> 40 41 #include <net/if_var.h> 42 #include <net/netisr.h> 43 #include <net/route.h> 44 45 #include <netproto/mpls/mpls.h> 46 #include <netproto/mpls/mpls_var.h> 47 48 struct mpls_stats mplsstats_percpu[MAXCPU]; 49 struct route mplsforward_rt[MAXCPU]; 50 51 int mplsforwarding = 1; 52 /* 53 SYSCTL_INT(_net_mpls, OID_AUTO, forwarding, CTLFLAG_RW, 54 &mplsforwarding, 0, "Enable MPLS forwarding between interfaces"); 55 */ 56 57 static void mpls_input_handler(struct netmsg *); 58 static void mpls_forward(struct mbuf *); 59 60 void 61 mpls_init(void) 62 { 63 #ifdef SMP 64 int cpu; 65 #endif 66 67 /* 68 * Initialize MPLS statistics counters for each CPU. 69 * 70 */ 71 #ifdef SMP 72 for (cpu = 0; cpu < ncpus; ++cpu) { 73 bzero(&mplsstats_percpu[cpu], sizeof(struct mpls_stats)); 74 } 75 #else 76 bzero(&mplsstat, sizeof(struct mpls_stats)); 77 #endif 78 79 netisr_register(NETISR_MPLS, mpls_mport, mpls_input_handler); 80 } 81 82 static void 83 mpls_input_handler(struct netmsg *msg0) 84 { 85 struct mbuf *m = ((struct netmsg_packet *)msg0)->nm_packet; 86 87 mpls_input(m); 88 } 89 90 void 91 mpls_input(struct mbuf *m) 92 { 93 struct mpls *mpls = NULL; 94 mpls_label_t label; 95 96 M_ASSERTPKTHDR(m); 97 98 mplsstat.mplss_total++; 99 100 /* length checks already performed at mpls_demux() */ 101 KASSERT(m->m_pkthdr.len >= sizeof(struct mpls), 102 ("mpls_input: mpls header too small")); 103 104 again: 105 if (m->m_len < sizeof(struct mpls)) { 106 m = m_pullup(m, sizeof(struct mpls)); 107 if (m == NULL) { 108 mplsstat.mplss_toosmall++; 109 return; 110 } 111 } 112 113 mpls = mtod(m, struct mpls*); 114 label = MPLS_LABEL(ntohl(mpls->mpls_shim)); 115 switch (label) { 116 case 0: 117 /* 118 * Label 0: represents "IPv4 Explicit NULL Label". 119 */ 120 if (MPLS_STACK(ntohl(mpls->mpls_shim))) { 121 /* Decapsulate the ip datagram from the mpls frame. */ 122 m_adj(m, sizeof(struct mpls)); 123 /* 124 ip_input(m); 125 */ 126 netisr_dispatch(NETISR_IP, m); 127 return; 128 } 129 goto again; /* If not the bottom label, per RFC4182. */ 130 131 case 1: 132 /* 133 * Label 1: represents "Router Alert Label" and is valid 134 * anywhere except at the bottom of the stack. 135 */ 136 break; 137 138 case 2: 139 /* 140 * Label 2: represents "IPv6 Explicit NULL Label". 141 */ 142 if (MPLS_STACK(ntohl(mpls->mpls_shim))) { 143 /* Decapsulate the ip datagram from the mpls frame. */ 144 m_adj(m, sizeof(struct mpls)); 145 netisr_dispatch(NETISR_IPV6, m); 146 return; 147 } 148 goto again; /* If not the bottom label, per RFC4182. */ 149 150 case 3: 151 /* 152 * Label 3: represents the "Implicit NULL Label" and must not 153 * appear on the wire. 154 */ 155 break; 156 default: 157 /* 158 * Labels 4 - 15: reserved, drop them. 159 */ 160 if (label <= 15) { 161 mplsstat.mplss_reserved++; 162 m_freem(m); 163 return; 164 } 165 if (mplsforwarding) { 166 mpls_forward(m); 167 return; 168 } else { 169 mplsstat.mplss_cantforward++; 170 m_freem(m); 171 return; 172 } 173 } 174 175 mplsstat.mplss_invalid++; 176 m_freem(m); 177 } 178 179 static void 180 mpls_forward(struct mbuf *m) 181 { 182 struct sockaddr_mpls *smpls; 183 struct mpls *mpls; 184 struct route *cache_rt = &mplsforward_rt[mycpuid]; 185 mpls_label_t label; 186 struct ifnet *ifp; 187 struct sockaddr *dst; 188 int error; 189 190 KASSERT(m->m_len >= sizeof(struct mpls), 191 ("mpls_forward: mpls header not in one mbuf")); 192 193 mpls = mtod(m, struct mpls *); 194 label = MPLS_LABEL(ntohl(mpls->mpls_shim)); 195 196 smpls = (struct sockaddr_mpls *) &cache_rt->ro_dst; 197 if (cache_rt->ro_rt == NULL || smpls->smpls_label != label) { 198 if (cache_rt->ro_rt != NULL) { 199 RTFREE(cache_rt->ro_rt); 200 cache_rt->ro_rt = NULL; 201 } 202 smpls->smpls_family = AF_MPLS; 203 smpls->smpls_len = sizeof(struct sockaddr_mpls); 204 smpls->smpls_label = htonl(label); 205 rtalloc(cache_rt); 206 if (cache_rt->ro_rt == NULL) { 207 /* route not found */ 208 return; 209 } 210 } 211 212 ifp = cache_rt->ro_rt->rt_ifp; 213 dst = cache_rt->ro_rt->rt_gateway; 214 error = mpls_output(m, cache_rt->ro_rt); 215 if (error) 216 goto bad; 217 error = (*ifp->if_output)(ifp, m, dst, cache_rt->ro_rt); 218 if (error) 219 goto bad; 220 mplsstat.mplss_forwarded++; 221 222 return; 223 bad: 224 m_freem(m); 225 } 226