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 1.4 2008/09/24 14:26:39 sephe 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 NETISR_FLAG_NOTMPSAFE); 81 } 82 83 static void 84 mpls_input_handler(struct netmsg *msg0) 85 { 86 struct mbuf *m = ((struct netmsg_packet *)msg0)->nm_packet; 87 88 mpls_input(m); 89 } 90 91 void 92 mpls_input(struct mbuf *m) 93 { 94 struct mpls *mpls = NULL; 95 mpls_label_t label; 96 97 M_ASSERTPKTHDR(m); 98 99 mplsstat.mplss_total++; 100 101 /* length checks already performed at mpls_demux() */ 102 KASSERT(m->m_pkthdr.len >= sizeof(struct mpls), 103 ("mpls_input: mpls header too small")); 104 105 again: 106 if (m->m_len < sizeof(struct mpls)) { 107 m = m_pullup(m, sizeof(struct mpls)); 108 if (m == NULL) { 109 mplsstat.mplss_toosmall++; 110 return; 111 } 112 } 113 114 mpls = mtod(m, struct mpls*); 115 label = MPLS_LABEL(ntohl(mpls->mpls_shim)); 116 switch (label) { 117 case 0: 118 /* 119 * Label 0: represents "IPv4 Explicit NULL Label". 120 */ 121 if (MPLS_STACK(ntohl(mpls->mpls_shim))) { 122 /* Decapsulate the ip datagram from the mpls frame. */ 123 m_adj(m, sizeof(struct mpls)); 124 /* 125 ip_input(m); 126 */ 127 netisr_dispatch(NETISR_IP, m); 128 return; 129 } 130 goto again; /* If not the bottom label, per RFC4182. */ 131 132 case 1: 133 /* 134 * Label 1: represents "Router Alert Label" and is valid 135 * anywhere except at the bottom of the stack. 136 */ 137 break; 138 139 case 2: 140 /* 141 * Label 2: represents "IPv6 Explicit NULL Label". 142 */ 143 if (MPLS_STACK(ntohl(mpls->mpls_shim))) { 144 /* Decapsulate the ip datagram from the mpls frame. */ 145 m_adj(m, sizeof(struct mpls)); 146 netisr_dispatch(NETISR_IPV6, m); 147 return; 148 } 149 goto again; /* If not the bottom label, per RFC4182. */ 150 151 case 3: 152 /* 153 * Label 3: represents the "Implicit NULL Label" and must not 154 * appear on the wire. 155 */ 156 break; 157 default: 158 /* 159 * Labels 4 - 15: reserved, drop them. 160 */ 161 if (label <= 15) { 162 mplsstat.mplss_reserved++; 163 m_freem(m); 164 return; 165 } 166 if (mplsforwarding) { 167 mpls_forward(m); 168 return; 169 } else { 170 mplsstat.mplss_cantforward++; 171 m_freem(m); 172 return; 173 } 174 } 175 176 mplsstat.mplss_invalid++; 177 m_freem(m); 178 } 179 180 static void 181 mpls_forward(struct mbuf *m) 182 { 183 struct sockaddr_mpls *smpls; 184 struct mpls *mpls; 185 struct route *cache_rt = &mplsforward_rt[mycpuid]; 186 mpls_label_t label; 187 struct ifnet *ifp; 188 struct sockaddr *dst; 189 int error; 190 191 KASSERT(m->m_len >= sizeof(struct mpls), 192 ("mpls_forward: mpls header not in one mbuf")); 193 194 mpls = mtod(m, struct mpls *); 195 label = MPLS_LABEL(ntohl(mpls->mpls_shim)); 196 197 smpls = (struct sockaddr_mpls *) &cache_rt->ro_dst; 198 if (cache_rt->ro_rt == NULL || smpls->smpls_label != label) { 199 if (cache_rt->ro_rt != NULL) { 200 RTFREE(cache_rt->ro_rt); 201 cache_rt->ro_rt = NULL; 202 } 203 smpls->smpls_family = AF_MPLS; 204 smpls->smpls_len = sizeof(struct sockaddr_mpls); 205 smpls->smpls_label = htonl(label); 206 rtalloc(cache_rt); 207 if (cache_rt->ro_rt == NULL) { 208 /* route not found */ 209 return; 210 } 211 } 212 213 ifp = cache_rt->ro_rt->rt_ifp; 214 dst = cache_rt->ro_rt->rt_gateway; 215 error = mpls_output(m, cache_rt->ro_rt); 216 if (error) 217 goto bad; 218 error = (*ifp->if_output)(ifp, m, dst, cache_rt->ro_rt); 219 if (error) 220 goto bad; 221 mplsstat.mplss_forwarded++; 222 223 return; 224 bad: 225 m_freem(m); 226 } 227