1 /* 2 * Copyright 1998 Massachusetts Institute of Technology 3 * 4 * Permission to use, copy, modify, and distribute this software and 5 * its documentation for any purpose and without fee is hereby 6 * granted, provided that both the above copyright notice and this 7 * permission notice appear in all copies, that both the above 8 * copyright notice and this permission notice appear in all 9 * supporting documentation, and that the name of M.I.T. not be used 10 * in advertising or publicity pertaining to distribution of the 11 * software without specific, written prior permission. M.I.T. makes 12 * no representations about the suitability of this software for any 13 * purpose. It is provided "as is" without express or implied 14 * warranty. 15 * 16 * THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''. M.I.T. DISCLAIMS 17 * ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE, 18 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 19 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT 20 * SHALL M.I.T. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF 23 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 25 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 26 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * $FreeBSD$ 30 */ 31 32 /* 33 * if_vlan.c - pseudo-device driver for IEEE 802.1Q virtual LANs. 34 * Might be extended some day to also handle IEEE 802.1p priority 35 * tagging. This is sort of sneaky in the implementation, since 36 * we need to pretend to be enough of an Ethernet implementation 37 * to make arp work. The way we do this is by telling everyone 38 * that we are an Ethernet, and then catch the packets that 39 * ether_output() left on our output queue queue when it calls 40 * if_start(), rewrite them for use by the real outgoing interface, 41 * and ask it to send them. 42 * 43 * 44 * XXX It's incorrect to assume that we must always kludge up 45 * headers on the physical device's behalf: some devices support 46 * VLAN tag insersion and extraction in firmware. For these cases, 47 * one can change the behavior of the vlan interface by setting 48 * the LINK0 flag on it (that is setting the vlan interface's LINK0 49 * flag, _not_ the parent's LINK0 flag; we try to leave the parent 50 * alone). If the interface as the LINK0 flag set, then it will 51 * not modify the ethernet header on output because the parent 52 * can do that for itself. On input, the parent can call vlan_input_tag() 53 * directly in order to supply us with an incoming mbuf and the vlan 54 * tag value that goes with it. 55 */ 56 57 #include "vlan.h" 58 #if NVLAN > 0 59 #include "opt_inet.h" 60 #include "bpf.h" 61 62 #include <sys/param.h> 63 #include <sys/kernel.h> 64 #include <sys/malloc.h> 65 #include <sys/mbuf.h> 66 #include <sys/queue.h> 67 #include <sys/socket.h> 68 #include <sys/sockio.h> 69 #include <sys/sysctl.h> 70 #include <sys/systm.h> 71 72 #if NBPF > 0 73 #include <net/bpf.h> 74 #endif 75 #include <net/ethernet.h> 76 #include <net/if.h> 77 #include <net/if_arp.h> 78 #include <net/if_dl.h> 79 #include <net/if_types.h> 80 #include <net/if_vlan_var.h> 81 82 #ifdef INET 83 #include <netinet/in.h> 84 #include <netinet/if_ether.h> 85 #endif 86 87 SYSCTL_DECL(_net_link); 88 SYSCTL_NODE(_net_link, IFT_8021_VLAN, vlan, CTLFLAG_RW, 0, "IEEE 802.1Q VLAN"); 89 SYSCTL_NODE(_net_link_vlan, PF_LINK, link, CTLFLAG_RW, 0, "for consistency"); 90 91 u_int vlan_proto = ETHERTYPE_VLAN; 92 SYSCTL_INT(_net_link_vlan_link, VLANCTL_PROTO, proto, CTLFLAG_RW, &vlan_proto, 93 0, "Ethernet protocol used for VLAN encapsulation"); 94 95 static struct ifvlan ifv_softc[NVLAN]; 96 97 static void vlan_start(struct ifnet *ifp); 98 static void vlan_ifinit(void *foo); 99 static int vlan_ioctl(struct ifnet *ifp, u_long cmd, caddr_t addr); 100 static int vlan_setmulti(struct ifnet *ifp); 101 static int vlan_unconfig(struct ifnet *ifp); 102 static int vlan_config(struct ifvlan *ifv, struct ifnet *p); 103 104 /* 105 * Program our multicast filter. What we're actually doing is 106 * programming the multicast filter of the parent. This has the 107 * side effect of causing the parent interface to receive multicast 108 * traffic that it doesn't really want, which ends up being discarded 109 * later by the upper protocol layers. Unfortunately, there's no way 110 * to avoid this: there really is only one physical interface. 111 */ 112 static int vlan_setmulti(struct ifnet *ifp) 113 { 114 struct ifnet *ifp_p; 115 struct ifmultiaddr *ifma, *rifma = NULL; 116 struct ifvlan *sc; 117 struct vlan_mc_entry *mc = NULL; 118 struct sockaddr_dl sdl; 119 int error; 120 121 /* Find the parent. */ 122 sc = ifp->if_softc; 123 ifp_p = sc->ifv_p; 124 125 sdl.sdl_len = ETHER_ADDR_LEN; 126 sdl.sdl_family = AF_LINK; 127 128 /* First, remove any existing filter entries. */ 129 while(sc->vlan_mc_listhead.slh_first != NULL) { 130 mc = sc->vlan_mc_listhead.slh_first; 131 bcopy((char *)&mc->mc_addr, LLADDR(&sdl), ETHER_ADDR_LEN); 132 error = if_delmulti(ifp_p, (struct sockaddr *)&sdl); 133 if (error) 134 return(error); 135 SLIST_REMOVE_HEAD(&sc->vlan_mc_listhead, mc_entries); 136 free(mc, M_DEVBUF); 137 } 138 139 /* Now program new ones. */ 140 for (ifma = ifp->if_multiaddrs.lh_first; 141 ifma != NULL;ifma = ifma->ifma_link.le_next) { 142 if (ifma->ifma_addr->sa_family != AF_LINK) 143 continue; 144 mc = malloc(sizeof(struct vlan_mc_entry), M_DEVBUF, M_NOWAIT); 145 bcopy(LLADDR((struct sockaddr_dl *)ifma->ifma_addr), 146 (char *)&mc->mc_addr, ETHER_ADDR_LEN); 147 SLIST_INSERT_HEAD(&sc->vlan_mc_listhead, mc, mc_entries); 148 error = if_addmulti(ifp_p, (struct sockaddr *)&sdl, &rifma); 149 if (error) 150 return(error); 151 } 152 153 return(0); 154 } 155 156 static void 157 vlaninit(void *dummy) 158 { 159 int i; 160 161 for (i = 0; i < NVLAN; i++) { 162 struct ifnet *ifp = &ifv_softc[i].ifv_if; 163 164 ifp->if_softc = &ifv_softc[i]; 165 ifp->if_name = "vlan"; 166 ifp->if_unit = i; 167 /* NB: flags are not set here */ 168 ifp->if_linkmib = &ifv_softc[i].ifv_mib; 169 ifp->if_linkmiblen = sizeof ifv_softc[i].ifv_mib; 170 /* NB: mtu is not set here */ 171 172 ifp->if_init = vlan_ifinit; 173 ifp->if_start = vlan_start; 174 ifp->if_ioctl = vlan_ioctl; 175 ifp->if_output = ether_output; 176 ifp->if_snd.ifq_maxlen = ifqmaxlen; 177 if_attach(ifp); 178 ether_ifattach(ifp); 179 #if NBPF > 0 180 bpfattach(ifp, DLT_EN10MB, sizeof(struct ether_header)); 181 #endif 182 /* Now undo some of the damage... */ 183 ifp->if_data.ifi_type = IFT_8021_VLAN; 184 ifp->if_data.ifi_hdrlen = EVL_ENCAPLEN; 185 ifp->if_resolvemulti = 0; 186 } 187 } 188 PSEUDO_SET(vlaninit, if_vlan); 189 190 static void 191 vlan_ifinit(void *foo) 192 { 193 return; 194 } 195 196 static void 197 vlan_start(struct ifnet *ifp) 198 { 199 struct ifvlan *ifv; 200 struct ifnet *p; 201 struct ether_vlan_header *evl; 202 struct mbuf *m; 203 204 ifv = ifp->if_softc; 205 p = ifv->ifv_p; 206 207 ifp->if_flags |= IFF_OACTIVE; 208 for (;;) { 209 IF_DEQUEUE(&ifp->if_snd, m); 210 if (m == 0) 211 break; 212 #if NBPF > 0 213 if (ifp->if_bpf) 214 bpf_mtap(ifp, m); 215 #endif /* NBPF > 0 */ 216 217 /* 218 * If the LINK0 flag is set, it means the underlying interface 219 * can do VLAN tag insertion itself and doesn't require us to 220 * create a special header for it. In this case, we just pass 221 * the packet along. However, we need some way to tell the 222 * interface where the packet came from so that it knows how 223 * to find the VLAN tag to use, so we set the rcvif in the 224 * mbuf header to our ifnet. 225 * 226 * Note: we also set the M_PROTO1 flag in the mbuf to let 227 * the parent driver know that the rcvif pointer is really 228 * valid. We need to do this because sometimes mbufs will 229 * be allocated by other parts of the system that contain 230 * garbage in the rcvif pointer. Using the M_PROTO1 flag 231 * lets the driver perform a proper sanity check and avoid 232 * following potentially bogus rcvif pointers off into 233 * never-never land. 234 */ 235 if (ifp->if_flags & IFF_LINK0) { 236 m->m_pkthdr.rcvif = ifp; 237 m->m_flags |= M_PROTO1; 238 } else { 239 M_PREPEND(m, EVL_ENCAPLEN, M_DONTWAIT); 240 if (m == 0) 241 continue; 242 /* M_PREPEND takes care of m_len, m_pkthdr.len for us */ 243 244 /* 245 * Transform the Ethernet header into an Ethernet header 246 * with 802.1Q encapsulation. 247 */ 248 bcopy(mtod(m, char *) + EVL_ENCAPLEN, mtod(m, char *), 249 sizeof(struct ether_header)); 250 evl = mtod(m, struct ether_vlan_header *); 251 evl->evl_proto = evl->evl_encap_proto; 252 evl->evl_encap_proto = htons(vlan_proto); 253 evl->evl_tag = htons(ifv->ifv_tag); 254 #ifdef DEBUG 255 printf("vlan_start: %*D\n", sizeof *evl, 256 (char *)evl, ":"); 257 #endif 258 } 259 260 /* 261 * Send it, precisely as ether_output() would have. 262 * We are already running at splimp. 263 */ 264 if (IF_QFULL(&p->if_snd)) { 265 IF_DROP(&p->if_snd); 266 /* XXX stats */ 267 ifp->if_oerrors++; 268 m_freem(m); 269 continue; 270 } 271 IF_ENQUEUE(&p->if_snd, m); 272 if ((p->if_flags & IFF_OACTIVE) == 0) { 273 p->if_start(p); 274 ifp->if_opackets++; 275 } 276 } 277 ifp->if_flags &= ~IFF_OACTIVE; 278 279 return; 280 } 281 282 void 283 vlan_input_tag(struct ether_header *eh, struct mbuf *m, u_int16_t t) 284 { 285 int i; 286 struct ifvlan *ifv; 287 288 for (i = 0; i < NVLAN; i++) { 289 ifv = &ifv_softc[i]; 290 if (ifv->ifv_tag == t) 291 break; 292 } 293 294 if (i >= NVLAN || (ifv->ifv_if.if_flags & IFF_UP) == 0) { 295 m_freem(m); 296 ifv->ifv_p->if_data.ifi_noproto++; 297 return; 298 } 299 300 /* 301 * Having found a valid vlan interface corresponding to 302 * the given source interface and vlan tag, run the 303 * the real packet through ethert_input(). 304 */ 305 m->m_pkthdr.rcvif = &ifv->ifv_if; 306 307 #if NBPF > 0 308 if (ifv->ifv_if.if_bpf) { 309 /* 310 * Do the usual BPF fakery. Note that we don't support 311 * promiscuous mode here, since it would require the 312 * drivers to know about VLANs and we're not ready for 313 * that yet. 314 */ 315 struct mbuf m0; 316 m0.m_next = m; 317 m0.m_len = sizeof(struct ether_header); 318 m0.m_data = (char *)eh; 319 bpf_mtap(&ifv->ifv_if, &m0); 320 } 321 #endif 322 ifv->ifv_if.if_ipackets++; 323 ether_input(&ifv->ifv_if, eh, m); 324 return; 325 } 326 327 int 328 vlan_input(struct ether_header *eh, struct mbuf *m) 329 { 330 int i; 331 struct ifvlan *ifv; 332 333 for (i = 0; i < NVLAN; i++) { 334 ifv = &ifv_softc[i]; 335 if (m->m_pkthdr.rcvif == ifv->ifv_p 336 && (EVL_VLANOFTAG(ntohs(*mtod(m, u_int16_t *))) 337 == ifv->ifv_tag)) 338 break; 339 } 340 341 if (i >= NVLAN || (ifv->ifv_if.if_flags & IFF_UP) == 0) { 342 m_freem(m); 343 return -1; /* so ether_input can take note */ 344 } 345 346 /* 347 * Having found a valid vlan interface corresponding to 348 * the given source interface and vlan tag, remove the 349 * encapsulation, and run the real packet through 350 * ether_input() a second time (it had better be 351 * reentrant!). 352 */ 353 m->m_pkthdr.rcvif = &ifv->ifv_if; 354 eh->ether_type = mtod(m, u_int16_t *)[1]; 355 m->m_data += EVL_ENCAPLEN; 356 m->m_len -= EVL_ENCAPLEN; 357 m->m_pkthdr.len -= EVL_ENCAPLEN; 358 359 #if NBPF > 0 360 if (ifv->ifv_if.if_bpf) { 361 /* 362 * Do the usual BPF fakery. Note that we don't support 363 * promiscuous mode here, since it would require the 364 * drivers to know about VLANs and we're not ready for 365 * that yet. 366 */ 367 struct mbuf m0; 368 m0.m_next = m; 369 m0.m_len = sizeof(struct ether_header); 370 m0.m_data = (char *)eh; 371 bpf_mtap(&ifv->ifv_if, &m0); 372 } 373 #endif 374 ifv->ifv_if.if_ipackets++; 375 ether_input(&ifv->ifv_if, eh, m); 376 return 0; 377 } 378 379 static int 380 vlan_config(struct ifvlan *ifv, struct ifnet *p) 381 { 382 struct ifaddr *ifa1, *ifa2; 383 struct sockaddr_dl *sdl1, *sdl2; 384 385 if (p->if_data.ifi_type != IFT_ETHER) 386 return EPROTONOSUPPORT; 387 if (ifv->ifv_p) 388 return EBUSY; 389 ifv->ifv_p = p; 390 if (p->if_data.ifi_hdrlen == sizeof(struct ether_vlan_header)) 391 ifv->ifv_if.if_mtu = p->if_mtu; 392 else 393 ifv->ifv_if.if_mtu = p->if_data.ifi_mtu - EVL_ENCAPLEN; 394 395 /* 396 * Preserve the state of the LINK0 flag for ourselves. 397 */ 398 ifv->ifv_if.if_flags = (p->if_flags & ~(IFF_LINK0)); 399 400 /* 401 * Set up our ``Ethernet address'' to reflect the underlying 402 * physical interface's. 403 */ 404 ifa1 = ifnet_addrs[ifv->ifv_if.if_index - 1]; 405 ifa2 = ifnet_addrs[p->if_index - 1]; 406 sdl1 = (struct sockaddr_dl *)ifa1->ifa_addr; 407 sdl2 = (struct sockaddr_dl *)ifa2->ifa_addr; 408 sdl1->sdl_type = IFT_ETHER; 409 sdl1->sdl_alen = ETHER_ADDR_LEN; 410 bcopy(LLADDR(sdl2), LLADDR(sdl1), ETHER_ADDR_LEN); 411 bcopy(LLADDR(sdl2), ifv->ifv_ac.ac_enaddr, ETHER_ADDR_LEN); 412 return 0; 413 } 414 415 static int 416 vlan_unconfig(struct ifnet *ifp) 417 { 418 struct ifaddr *ifa; 419 struct sockaddr_dl *sdl; 420 struct vlan_mc_entry *mc; 421 struct ifvlan *ifv; 422 struct ifnet *p; 423 int error; 424 425 ifv = ifp->if_softc; 426 p = ifv->ifv_p; 427 428 /* 429 * Since the interface is being unconfigured, we need to 430 * empty the list of multicast groups that we may have joined 431 * while we were alive and remove them from the parent's list 432 * as well. 433 */ 434 while(ifv->vlan_mc_listhead.slh_first != NULL) { 435 struct sockaddr_dl sdl; 436 437 sdl.sdl_len = ETHER_ADDR_LEN; 438 sdl.sdl_family = AF_LINK; 439 mc = ifv->vlan_mc_listhead.slh_first; 440 bcopy((char *)&mc->mc_addr, LLADDR(&sdl), ETHER_ADDR_LEN); 441 error = if_delmulti(p, (struct sockaddr *)&sdl); 442 error = if_delmulti(ifp, (struct sockaddr *)&sdl); 443 if (error) 444 return(error); 445 SLIST_REMOVE_HEAD(&ifv->vlan_mc_listhead, mc_entries); 446 free(mc, M_DEVBUF); 447 } 448 449 /* Disconnect from parent. */ 450 ifv->ifv_p = NULL; 451 ifv->ifv_if.if_mtu = ETHERMTU; 452 453 /* Clear our MAC address. */ 454 ifa = ifnet_addrs[ifv->ifv_if.if_index - 1]; 455 sdl = (struct sockaddr_dl *)ifa->ifa_addr; 456 sdl->sdl_type = IFT_ETHER; 457 sdl->sdl_alen = ETHER_ADDR_LEN; 458 bzero(LLADDR(sdl), ETHER_ADDR_LEN); 459 bzero(ifv->ifv_ac.ac_enaddr, ETHER_ADDR_LEN); 460 461 return 0; 462 } 463 464 static int 465 vlan_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 466 { 467 struct ifaddr *ifa; 468 struct ifnet *p; 469 struct ifreq *ifr; 470 struct ifvlan *ifv; 471 struct vlanreq vlr; 472 int error = 0; 473 474 ifr = (struct ifreq *)data; 475 ifa = (struct ifaddr *)data; 476 ifv = ifp->if_softc; 477 478 switch (cmd) { 479 case SIOCSIFADDR: 480 ifp->if_flags |= IFF_UP; 481 482 switch (ifa->ifa_addr->sa_family) { 483 #ifdef INET 484 case AF_INET: 485 arp_ifinit(&ifv->ifv_ac, ifa); 486 break; 487 #endif 488 default: 489 break; 490 } 491 break; 492 493 case SIOCGIFADDR: 494 { 495 struct sockaddr *sa; 496 497 sa = (struct sockaddr *) &ifr->ifr_data; 498 bcopy(((struct arpcom *)ifp->if_softc)->ac_enaddr, 499 (caddr_t) sa->sa_data, ETHER_ADDR_LEN); 500 } 501 break; 502 503 case SIOCSIFMTU: 504 /* 505 * Set the interface MTU. 506 * This is bogus. The underlying interface might support 507 * jumbo frames. 508 */ 509 if (ifr->ifr_mtu > ETHERMTU) { 510 error = EINVAL; 511 } else { 512 ifp->if_mtu = ifr->ifr_mtu; 513 } 514 break; 515 516 case SIOCSETVLAN: 517 error = copyin(ifr->ifr_data, &vlr, sizeof vlr); 518 if (error) 519 break; 520 if (vlr.vlr_parent[0] == '\0') { 521 vlan_unconfig(ifp); 522 if_down(ifp); 523 ifp->if_flags = 0; 524 break; 525 } 526 p = ifunit(vlr.vlr_parent); 527 if (p == 0) { 528 error = ENOENT; 529 break; 530 } 531 error = vlan_config(ifv, p); 532 if (error) 533 break; 534 ifv->ifv_tag = vlr.vlr_tag; 535 break; 536 537 case SIOCGETVLAN: 538 bzero(&vlr, sizeof vlr); 539 if (ifv->ifv_p) { 540 snprintf(vlr.vlr_parent, sizeof(vlr.vlr_parent), 541 "%s%d", ifv->ifv_p->if_name, ifv->ifv_p->if_unit); 542 vlr.vlr_tag = ifv->ifv_tag; 543 } 544 error = copyout(&vlr, ifr->ifr_data, sizeof vlr); 545 break; 546 547 case SIOCSIFFLAGS: 548 /* 549 * We don't support promiscuous mode 550 * right now because it would require help from the 551 * underlying drivers, which hasn't been implemented. 552 */ 553 if (ifr->ifr_flags & (IFF_PROMISC)) { 554 ifp->if_flags &= ~(IFF_PROMISC); 555 error = EINVAL; 556 } 557 break; 558 case SIOCADDMULTI: 559 case SIOCDELMULTI: 560 error = vlan_setmulti(ifp); 561 break; 562 default: 563 error = EINVAL; 564 } 565 return error; 566 } 567 568 #endif /* NVLAN > 0 */ 569