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 32 #include <sys/globaldata.h> 33 #include <sys/kernel.h> 34 #include <sys/mbuf.h> 35 #include <sys/param.h> 36 #include <sys/sysctl.h> 37 #include <sys/systm.h> 38 39 #include <net/if_var.h> 40 #include <net/netisr.h> 41 #include <net/route.h> 42 43 #include <sys/thread2.h> 44 #include <sys/mplock2.h> 45 46 #include <netproto/mpls/mpls.h> 47 #include <netproto/mpls/mpls_var.h> 48 49 struct mpls_stats mplsstats_percpu[MAXCPU]; 50 struct route mplsforward_rt[MAXCPU]; 51 52 int mplsforwarding = 1; 53 /* 54 SYSCTL_INT(_net_mpls, OID_AUTO, forwarding, CTLFLAG_RW, 55 &mplsforwarding, 0, "Enable MPLS forwarding between interfaces"); 56 */ 57 58 static void mpls_input_handler(netmsg_t); 59 static void mpls_forward(struct mbuf *); 60 61 void 62 mpls_init(void) 63 { 64 int cpu; 65 66 /* 67 * Initialize MPLS statistics counters for each CPU. 68 * 69 */ 70 for (cpu = 0; cpu < ncpus; ++cpu) { 71 bzero(&mplsstats_percpu[cpu], sizeof(struct mpls_stats)); 72 } 73 74 netisr_register(NETISR_MPLS, mpls_input_handler, mpls_hashfn); 75 } 76 77 static void 78 mpls_input_handler(netmsg_t msg) 79 { 80 struct mbuf *m = msg->packet.nm_packet; 81 82 get_mplock(); 83 mpls_input(m); 84 rel_mplock(); 85 /* do not reply, msg embedded in mbuf */ 86 } 87 88 void 89 mpls_input(struct mbuf *m) 90 { 91 struct mpls *mpls = NULL; 92 mpls_label_t label; 93 94 M_ASSERTPKTHDR(m); 95 96 mplsstat.mplss_total++; 97 98 /* length checks already performed at mpls_demux() */ 99 KASSERT(m->m_pkthdr.len >= sizeof(struct mpls), 100 ("mpls_input: mpls header too small")); 101 102 again: 103 if (m->m_len < sizeof(struct mpls)) { 104 m = m_pullup(m, sizeof(struct mpls)); 105 if (m == NULL) { 106 mplsstat.mplss_toosmall++; 107 return; 108 } 109 } 110 111 mpls = mtod(m, struct mpls*); 112 label = MPLS_LABEL(ntohl(mpls->mpls_shim)); 113 switch (label) { 114 case 0: 115 /* 116 * Label 0: represents "IPv4 Explicit NULL Label". 117 */ 118 if (MPLS_STACK(ntohl(mpls->mpls_shim))) { 119 /* Decapsulate the ip datagram from the mpls frame. */ 120 m_adj(m, sizeof(struct mpls)); 121 netisr_queue(NETISR_IP, m); 122 return; 123 } 124 goto again; /* If not the bottom label, per RFC4182. */ 125 126 case 1: 127 /* 128 * Label 1: represents "Router Alert Label" and is valid 129 * anywhere except at the bottom of the stack. 130 */ 131 break; 132 133 case 2: 134 /* 135 * Label 2: represents "IPv6 Explicit NULL Label". 136 */ 137 if (MPLS_STACK(ntohl(mpls->mpls_shim))) { 138 /* Decapsulate the ip datagram from the mpls frame. */ 139 m_adj(m, sizeof(struct mpls)); 140 netisr_queue(NETISR_IPV6, m); 141 return; 142 } 143 goto again; /* If not the bottom label, per RFC4182. */ 144 145 case 3: 146 /* 147 * Label 3: represents the "Implicit NULL Label" and must not 148 * appear on the wire. 149 */ 150 break; 151 default: 152 /* 153 * Labels 4 - 15: reserved, drop them. 154 */ 155 if (label <= 15) { 156 mplsstat.mplss_reserved++; 157 m_freem(m); 158 return; 159 } 160 if (mplsforwarding) { 161 mpls_forward(m); 162 return; 163 } else { 164 mplsstat.mplss_cantforward++; 165 m_freem(m); 166 return; 167 } 168 } 169 170 mplsstat.mplss_invalid++; 171 m_freem(m); 172 } 173 174 static void 175 mpls_forward(struct mbuf *m) 176 { 177 struct sockaddr_mpls *smpls; 178 struct mpls *mpls; 179 struct route *cache_rt = &mplsforward_rt[mycpuid]; 180 mpls_label_t label; 181 struct ifnet *ifp; 182 struct sockaddr *dst; 183 int error; 184 185 KASSERT(m->m_len >= sizeof(struct mpls), 186 ("mpls_forward: mpls header not in one mbuf")); 187 188 mpls = mtod(m, struct mpls *); 189 label = MPLS_LABEL(ntohl(mpls->mpls_shim)); 190 191 smpls = (struct sockaddr_mpls *) &cache_rt->ro_dst; 192 if (cache_rt->ro_rt == NULL || smpls->smpls_label != label) { 193 if (cache_rt->ro_rt != NULL) { 194 RTFREE(cache_rt->ro_rt); 195 cache_rt->ro_rt = NULL; 196 } 197 smpls->smpls_family = AF_MPLS; 198 smpls->smpls_len = sizeof(struct sockaddr_mpls); 199 smpls->smpls_label = htonl(label); 200 rtalloc(cache_rt); 201 if (cache_rt->ro_rt == NULL) { 202 /* route not found */ 203 return; 204 } 205 } 206 207 ifp = cache_rt->ro_rt->rt_ifp; 208 dst = cache_rt->ro_rt->rt_gateway; 209 error = mpls_output(m, cache_rt->ro_rt); 210 if (error) 211 goto bad; 212 error = (*ifp->if_output)(ifp, m, dst, cache_rt->ro_rt); 213 if (error) 214 goto bad; 215 mplsstat.mplss_forwarded++; 216 217 return; 218 bad: 219 m_freem(m); 220 } 221