1 /* $OpenBSD: if_mpe.c,v 1.62 2017/08/14 16:14:02 reyk Exp $ */ 2 3 /* 4 * Copyright (c) 2008 Pierre-Yves Ritschard <pyr@spootnik.org> 5 * 6 * Permission to use, copy, modify, and distribute this software for any 7 * purpose with or without fee is hereby granted, provided that the above 8 * copyright notice and this permission notice appear in all copies. 9 * 10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17 */ 18 #include "mpe.h" 19 20 #include <sys/param.h> 21 #include <sys/systm.h> 22 #include <sys/mbuf.h> 23 #include <sys/socket.h> 24 #include <sys/sockio.h> 25 #include <sys/ioctl.h> 26 27 #include <net/if.h> 28 #include <net/if_dl.h> 29 #include <net/if_var.h> 30 #include <net/if_types.h> 31 #include <net/netisr.h> 32 #include <net/route.h> 33 34 #include <netinet/in.h> 35 #include <netinet/ip.h> 36 37 #ifdef INET6 38 #include <netinet/ip6.h> 39 #endif /* INET6 */ 40 41 #include "bpfilter.h" 42 #if NBPFILTER > 0 43 #include <net/bpf.h> 44 #endif 45 46 #include <netmpls/mpls.h> 47 48 #ifdef MPLS_DEBUG 49 #define DPRINTF(x) do { if (mpedebug) printf x ; } while (0) 50 #else 51 #define DPRINTF(x) 52 #endif 53 54 void mpeattach(int); 55 int mpeoutput(struct ifnet *, struct mbuf *, struct sockaddr *, 56 struct rtentry *); 57 int mpeioctl(struct ifnet *, u_long, caddr_t); 58 void mpestart(struct ifnet *); 59 int mpe_clone_create(struct if_clone *, int); 60 int mpe_clone_destroy(struct ifnet *); 61 62 LIST_HEAD(, mpe_softc) mpeif_list; 63 struct if_clone mpe_cloner = 64 IF_CLONE_INITIALIZER("mpe", mpe_clone_create, mpe_clone_destroy); 65 66 extern int mpls_mapttl_ip; 67 #ifdef INET6 68 extern int mpls_mapttl_ip6; 69 #endif 70 71 void 72 mpeattach(int nmpe) 73 { 74 LIST_INIT(&mpeif_list); 75 if_clone_attach(&mpe_cloner); 76 } 77 78 int 79 mpe_clone_create(struct if_clone *ifc, int unit) 80 { 81 struct ifnet *ifp; 82 struct mpe_softc *mpeif; 83 84 if ((mpeif = malloc(sizeof(*mpeif), 85 M_DEVBUF, M_NOWAIT|M_ZERO)) == NULL) 86 return (ENOMEM); 87 88 mpeif->sc_unit = unit; 89 ifp = &mpeif->sc_if; 90 snprintf(ifp->if_xname, sizeof ifp->if_xname, "mpe%d", unit); 91 ifp->if_flags = IFF_POINTOPOINT; 92 ifp->if_xflags = IFXF_CLONED; 93 ifp->if_softc = mpeif; 94 ifp->if_mtu = MPE_MTU; 95 ifp->if_ioctl = mpeioctl; 96 ifp->if_output = mpeoutput; 97 ifp->if_start = mpestart; 98 ifp->if_type = IFT_MPLS; 99 ifp->if_hdrlen = MPE_HDRLEN; 100 IFQ_SET_MAXLEN(&ifp->if_snd, IFQ_MAXLEN); 101 if_attach(ifp); 102 if_alloc_sadl(ifp); 103 #if NBPFILTER > 0 104 bpfattach(&ifp->if_bpf, ifp, DLT_LOOP, sizeof(u_int32_t)); 105 #endif 106 107 mpeif->sc_ifa.ifa_ifp = ifp; 108 mpeif->sc_ifa.ifa_addr = sdltosa(ifp->if_sadl); 109 mpeif->sc_smpls.smpls_len = sizeof(mpeif->sc_smpls); 110 mpeif->sc_smpls.smpls_family = AF_MPLS; 111 112 LIST_INSERT_HEAD(&mpeif_list, mpeif, sc_list); 113 114 return (0); 115 } 116 117 int 118 mpe_clone_destroy(struct ifnet *ifp) 119 { 120 struct mpe_softc *mpeif = ifp->if_softc; 121 122 LIST_REMOVE(mpeif, sc_list); 123 124 if (mpeif->sc_smpls.smpls_label) { 125 rt_ifa_del(&mpeif->sc_ifa, RTF_MPLS, 126 smplstosa(&mpeif->sc_smpls)); 127 } 128 129 if_detach(ifp); 130 free(mpeif, M_DEVBUF, sizeof *mpeif); 131 return (0); 132 } 133 134 struct sockaddr_storage mpedst; 135 /* 136 * Start output on the mpe interface. 137 */ 138 void 139 mpestart(struct ifnet *ifp0) 140 { 141 struct mbuf *m; 142 struct sockaddr *sa = sstosa(&mpedst); 143 sa_family_t af; 144 struct rtentry *rt; 145 struct ifnet *ifp; 146 147 for (;;) { 148 IFQ_DEQUEUE(&ifp0->if_snd, m); 149 if (m == NULL) 150 return; 151 152 af = *mtod(m, sa_family_t *); 153 m_adj(m, sizeof(af)); 154 switch (af) { 155 case AF_INET: 156 bzero(sa, sizeof(struct sockaddr_in)); 157 satosin(sa)->sin_family = af; 158 satosin(sa)->sin_len = sizeof(struct sockaddr_in); 159 bcopy(mtod(m, caddr_t), &satosin(sa)->sin_addr, 160 sizeof(in_addr_t)); 161 m_adj(m, sizeof(in_addr_t)); 162 break; 163 default: 164 m_freem(m); 165 continue; 166 } 167 168 rt = rtalloc(sa, RT_RESOLVE, 0); 169 if (!rtisvalid(rt)) { 170 m_freem(m); 171 rtfree(rt); 172 continue; 173 } 174 175 ifp = if_get(rt->rt_ifidx); 176 if (ifp == NULL) { 177 m_freem(m); 178 rtfree(rt); 179 continue; 180 } 181 182 #if NBPFILTER > 0 183 if (ifp0->if_bpf) { 184 /* remove MPLS label before passing packet to bpf */ 185 m->m_data += sizeof(struct shim_hdr); 186 m->m_len -= sizeof(struct shim_hdr); 187 m->m_pkthdr.len -= sizeof(struct shim_hdr); 188 bpf_mtap_af(ifp0->if_bpf, af, m, BPF_DIRECTION_OUT); 189 m->m_data -= sizeof(struct shim_hdr); 190 m->m_len += sizeof(struct shim_hdr); 191 m->m_pkthdr.len += sizeof(struct shim_hdr); 192 } 193 #endif 194 /* XXX lie, but mpls_output will only look at sa_family */ 195 sa->sa_family = AF_MPLS; 196 197 mpls_output(ifp, m, sa, rt); 198 if_put(ifp); 199 rtfree(rt); 200 } 201 } 202 203 int 204 mpeoutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 205 struct rtentry *rt) 206 { 207 struct shim_hdr shim; 208 int error; 209 int off; 210 u_int8_t op = 0; 211 212 #ifdef DIAGNOSTIC 213 if (ifp->if_rdomain != rtable_l2(m->m_pkthdr.ph_rtableid)) { 214 printf("%s: trying to send packet on wrong domain. " 215 "if %d vs. mbuf %d\n", ifp->if_xname, 216 ifp->if_rdomain, rtable_l2(m->m_pkthdr.ph_rtableid)); 217 } 218 #endif 219 m->m_pkthdr.ph_ifidx = ifp->if_index; 220 /* XXX assumes MPLS is always in rdomain 0 */ 221 m->m_pkthdr.ph_rtableid = 0; 222 223 error = 0; 224 switch (dst->sa_family) { 225 case AF_INET: 226 if (rt && rt->rt_flags & RTF_MPLS) { 227 shim.shim_label = 228 ((struct rt_mpls *)rt->rt_llinfo)->mpls_label; 229 shim.shim_label |= MPLS_BOS_MASK; 230 op = ((struct rt_mpls *)rt->rt_llinfo)->mpls_operation; 231 } 232 if (op != MPLS_OP_PUSH) { 233 m_freem(m); 234 error = ENETUNREACH; 235 goto out; 236 } 237 if (mpls_mapttl_ip) { 238 struct ip *ip; 239 ip = mtod(m, struct ip *); 240 shim.shim_label |= htonl(ip->ip_ttl) & MPLS_TTL_MASK; 241 } else 242 shim.shim_label |= htonl(mpls_defttl) & MPLS_TTL_MASK; 243 off = sizeof(sa_family_t) + sizeof(in_addr_t); 244 M_PREPEND(m, sizeof(shim) + off, M_DONTWAIT); 245 if (m == NULL) { 246 error = ENOBUFS; 247 goto out; 248 } 249 *mtod(m, sa_family_t *) = AF_INET; 250 m_copyback(m, sizeof(sa_family_t), sizeof(in_addr_t), 251 (caddr_t)&((satosin(dst)->sin_addr)), M_NOWAIT); 252 break; 253 default: 254 m_freem(m); 255 error = EPFNOSUPPORT; 256 goto out; 257 } 258 259 m_copyback(m, off, sizeof(shim), (caddr_t)&shim, M_NOWAIT); 260 261 error = if_enqueue(ifp, m); 262 out: 263 if (error) 264 ifp->if_oerrors++; 265 return (error); 266 } 267 268 int 269 mpeioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 270 { 271 struct mpe_softc *ifm; 272 struct ifreq *ifr; 273 struct shim_hdr shim; 274 int error = 0; 275 276 ifr = (struct ifreq *)data; 277 switch (cmd) { 278 case SIOCSIFADDR: 279 if (!ISSET(ifp->if_flags, IFF_UP)) 280 if_up(ifp); 281 break; 282 case SIOCSIFFLAGS: 283 if (ifp->if_flags & IFF_UP) 284 ifp->if_flags |= IFF_RUNNING; 285 else 286 ifp->if_flags &= ~IFF_RUNNING; 287 break; 288 case SIOCSIFMTU: 289 if (ifr->ifr_mtu < MPE_MTU_MIN || 290 ifr->ifr_mtu > MPE_MTU_MAX) 291 error = EINVAL; 292 else 293 ifp->if_mtu = ifr->ifr_mtu; 294 break; 295 case SIOCGETLABEL: 296 ifm = ifp->if_softc; 297 shim.shim_label = 298 ((ntohl(ifm->sc_smpls.smpls_label & MPLS_LABEL_MASK)) >> 299 MPLS_LABEL_OFFSET); 300 error = copyout(&shim, ifr->ifr_data, sizeof(shim)); 301 break; 302 case SIOCSETLABEL: 303 ifm = ifp->if_softc; 304 if ((error = copyin(ifr->ifr_data, &shim, sizeof(shim)))) 305 break; 306 if (shim.shim_label > MPLS_LABEL_MAX || 307 shim.shim_label <= MPLS_LABEL_RESERVED_MAX) { 308 error = EINVAL; 309 break; 310 } 311 shim.shim_label = htonl(shim.shim_label << MPLS_LABEL_OFFSET); 312 if (ifm->sc_smpls.smpls_label == shim.shim_label) 313 break; 314 LIST_FOREACH(ifm, &mpeif_list, sc_list) { 315 if (ifm != ifp->if_softc && 316 ifm->sc_smpls.smpls_label == shim.shim_label) { 317 error = EEXIST; 318 break; 319 } 320 } 321 if (error) 322 break; 323 ifm = ifp->if_softc; 324 if (ifm->sc_smpls.smpls_label) { 325 /* remove old MPLS route */ 326 rt_ifa_del(&ifm->sc_ifa, RTF_MPLS, 327 smplstosa(&ifm->sc_smpls)); 328 } 329 /* add new MPLS route */ 330 ifm->sc_smpls.smpls_label = shim.shim_label; 331 error = rt_ifa_add(&ifm->sc_ifa, RTF_MPLS, 332 smplstosa(&ifm->sc_smpls)); 333 if (error) { 334 ifm->sc_smpls.smpls_label = 0; 335 break; 336 } 337 break; 338 case SIOCSIFRDOMAIN: 339 /* must readd the MPLS "route" for our label */ 340 ifm = ifp->if_softc; 341 if (ifr->ifr_rdomainid != ifp->if_rdomain) { 342 if (ifm->sc_smpls.smpls_label) { 343 rt_ifa_add(&ifm->sc_ifa, RTF_MPLS, 344 smplstosa(&ifm->sc_smpls)); 345 } 346 } 347 /* return with ENOTTY so that the parent handler finishes */ 348 return (ENOTTY); 349 default: 350 return (ENOTTY); 351 } 352 353 return (error); 354 } 355 356 void 357 mpe_input(struct mbuf *m, struct ifnet *ifp, struct sockaddr_mpls *smpls, 358 u_int8_t ttl) 359 { 360 struct ip *ip; 361 int hlen; 362 363 /* label -> AF lookup */ 364 365 if (mpls_mapttl_ip) { 366 if (m->m_len < sizeof (struct ip) && 367 (m = m_pullup(m, sizeof(struct ip))) == NULL) 368 return; 369 ip = mtod(m, struct ip *); 370 hlen = ip->ip_hl << 2; 371 if (m->m_len < hlen) { 372 if ((m = m_pullup(m, hlen)) == NULL) 373 return; 374 ip = mtod(m, struct ip *); 375 } 376 377 if (in_cksum(m, hlen) != 0) { 378 m_freem(m); 379 return; 380 } 381 382 /* set IP ttl from MPLS ttl */ 383 ip->ip_ttl = ttl; 384 385 /* recalculate checksum */ 386 ip->ip_sum = 0; 387 ip->ip_sum = in_cksum(m, hlen); 388 } 389 390 /* new receive if and move into correct rtable */ 391 m->m_pkthdr.ph_ifidx = ifp->if_index; 392 m->m_pkthdr.ph_rtableid = ifp->if_rdomain; 393 394 #if NBPFILTER > 0 395 if (ifp->if_bpf) 396 bpf_mtap_af(ifp->if_bpf, AF_INET, m, BPF_DIRECTION_IN); 397 #endif 398 399 ipv4_input(ifp, m); 400 } 401 402 #ifdef INET6 403 void 404 mpe_input6(struct mbuf *m, struct ifnet *ifp, struct sockaddr_mpls *smpls, 405 u_int8_t ttl) 406 { 407 struct ip6_hdr *ip6hdr; 408 409 /* label -> AF lookup */ 410 411 if (mpls_mapttl_ip6) { 412 if (m->m_len < sizeof (struct ip6_hdr) && 413 (m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) 414 return; 415 416 ip6hdr = mtod(m, struct ip6_hdr *); 417 418 /* set IPv6 ttl from MPLS ttl */ 419 ip6hdr->ip6_hlim = ttl; 420 } 421 422 /* new receive if and move into correct rtable */ 423 m->m_pkthdr.ph_ifidx = ifp->if_index; 424 m->m_pkthdr.ph_rtableid = ifp->if_rdomain; 425 426 #if NBPFILTER > 0 427 if (ifp->if_bpf) 428 bpf_mtap_af(ifp->if_bpf, AF_INET6, m, BPF_DIRECTION_IN); 429 #endif 430 431 ipv6_input(ifp, m); 432 } 433 #endif /* INET6 */ 434