1 /* SCTP kernel implementation 2 * (C) Copyright IBM Corp. 2002, 2004 3 * Copyright (c) 2001 Nokia, Inc. 4 * Copyright (c) 2001 La Monte H.P. Yarroll 5 * Copyright (c) 2002-2003 Intel Corp. 6 * 7 * This file is part of the SCTP kernel implementation 8 * 9 * SCTP over IPv6. 10 * 11 * This SCTP implementation is free software; 12 * you can redistribute it and/or modify it under the terms of 13 * the GNU General Public License as published by 14 * the Free Software Foundation; either version 2, or (at your option) 15 * any later version. 16 * 17 * This SCTP implementation is distributed in the hope that it 18 * will be useful, but WITHOUT ANY WARRANTY; without even the implied 19 * ************************ 20 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 21 * See the GNU General Public License for more details. 22 * 23 * You should have received a copy of the GNU General Public License 24 * along with GNU CC; see the file COPYING. If not, see 25 * <http://www.gnu.org/licenses/>. 26 * 27 * Please send any bug reports or fixes you make to the 28 * email address(es): 29 * lksctp developers <linux-sctp@vger.kernel.org> 30 * 31 * Written or modified by: 32 * Le Yanqun <yanqun.le@nokia.com> 33 * Hui Huang <hui.huang@nokia.com> 34 * La Monte H.P. Yarroll <piggy@acm.org> 35 * Sridhar Samudrala <sri@us.ibm.com> 36 * Jon Grimm <jgrimm@us.ibm.com> 37 * Ardelle Fan <ardelle.fan@intel.com> 38 * 39 * Based on: 40 * linux/net/ipv6/tcp_ipv6.c 41 */ 42 43 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 44 45 #include <linux/module.h> 46 #include <linux/errno.h> 47 #include <linux/types.h> 48 #include <linux/socket.h> 49 #include <linux/sockios.h> 50 #include <linux/net.h> 51 #include <linux/in.h> 52 #include <linux/in6.h> 53 #include <linux/netdevice.h> 54 #include <linux/init.h> 55 #include <linux/ipsec.h> 56 #include <linux/slab.h> 57 58 #include <linux/ipv6.h> 59 #include <linux/icmpv6.h> 60 #include <linux/random.h> 61 #include <linux/seq_file.h> 62 63 #include <net/protocol.h> 64 #include <net/ndisc.h> 65 #include <net/ip.h> 66 #include <net/ipv6.h> 67 #include <net/transp_v6.h> 68 #include <net/addrconf.h> 69 #include <net/ip6_route.h> 70 #include <net/inet_common.h> 71 #include <net/inet_ecn.h> 72 #include <net/sctp/sctp.h> 73 74 #include <linux/uaccess.h> 75 76 static inline int sctp_v6_addr_match_len(union sctp_addr *s1, 77 union sctp_addr *s2); 78 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr, 79 __be16 port); 80 static int sctp_v6_cmp_addr(const union sctp_addr *addr1, 81 const union sctp_addr *addr2); 82 83 /* Event handler for inet6 address addition/deletion events. 84 * The sctp_local_addr_list needs to be protocted by a spin lock since 85 * multiple notifiers (say IPv4 and IPv6) may be running at the same 86 * time and thus corrupt the list. 87 * The reader side is protected with RCU. 88 */ 89 static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev, 90 void *ptr) 91 { 92 struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr; 93 struct sctp_sockaddr_entry *addr = NULL; 94 struct sctp_sockaddr_entry *temp; 95 struct net *net = dev_net(ifa->idev->dev); 96 int found = 0; 97 98 switch (ev) { 99 case NETDEV_UP: 100 addr = kmalloc(sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC); 101 if (addr) { 102 addr->a.v6.sin6_family = AF_INET6; 103 addr->a.v6.sin6_port = 0; 104 addr->a.v6.sin6_addr = ifa->addr; 105 addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex; 106 addr->valid = 1; 107 spin_lock_bh(&net->sctp.local_addr_lock); 108 list_add_tail_rcu(&addr->list, &net->sctp.local_addr_list); 109 sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_NEW); 110 spin_unlock_bh(&net->sctp.local_addr_lock); 111 } 112 break; 113 case NETDEV_DOWN: 114 spin_lock_bh(&net->sctp.local_addr_lock); 115 list_for_each_entry_safe(addr, temp, 116 &net->sctp.local_addr_list, list) { 117 if (addr->a.sa.sa_family == AF_INET6 && 118 ipv6_addr_equal(&addr->a.v6.sin6_addr, 119 &ifa->addr)) { 120 sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL); 121 found = 1; 122 addr->valid = 0; 123 list_del_rcu(&addr->list); 124 break; 125 } 126 } 127 spin_unlock_bh(&net->sctp.local_addr_lock); 128 if (found) 129 kfree_rcu(addr, rcu); 130 break; 131 } 132 133 return NOTIFY_DONE; 134 } 135 136 static struct notifier_block sctp_inet6addr_notifier = { 137 .notifier_call = sctp_inet6addr_event, 138 }; 139 140 /* ICMP error handler. */ 141 static void sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 142 u8 type, u8 code, int offset, __be32 info) 143 { 144 struct inet6_dev *idev; 145 struct sock *sk; 146 struct sctp_association *asoc; 147 struct sctp_transport *transport; 148 struct ipv6_pinfo *np; 149 __u16 saveip, savesctp; 150 int err; 151 struct net *net = dev_net(skb->dev); 152 153 idev = in6_dev_get(skb->dev); 154 155 /* Fix up skb to look at the embedded net header. */ 156 saveip = skb->network_header; 157 savesctp = skb->transport_header; 158 skb_reset_network_header(skb); 159 skb_set_transport_header(skb, offset); 160 sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &transport); 161 /* Put back, the original pointers. */ 162 skb->network_header = saveip; 163 skb->transport_header = savesctp; 164 if (!sk) { 165 __ICMP6_INC_STATS(net, idev, ICMP6_MIB_INERRORS); 166 goto out; 167 } 168 169 /* Warning: The sock lock is held. Remember to call 170 * sctp_err_finish! 171 */ 172 173 switch (type) { 174 case ICMPV6_PKT_TOOBIG: 175 if (ip6_sk_accept_pmtu(sk)) 176 sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info)); 177 goto out_unlock; 178 case ICMPV6_PARAMPROB: 179 if (ICMPV6_UNK_NEXTHDR == code) { 180 sctp_icmp_proto_unreachable(sk, asoc, transport); 181 goto out_unlock; 182 } 183 break; 184 case NDISC_REDIRECT: 185 sctp_icmp_redirect(sk, transport, skb); 186 goto out_unlock; 187 default: 188 break; 189 } 190 191 np = inet6_sk(sk); 192 icmpv6_err_convert(type, code, &err); 193 if (!sock_owned_by_user(sk) && np->recverr) { 194 sk->sk_err = err; 195 sk->sk_error_report(sk); 196 } else { /* Only an error on timeout */ 197 sk->sk_err_soft = err; 198 } 199 200 out_unlock: 201 sctp_err_finish(sk, transport); 202 out: 203 if (likely(idev != NULL)) 204 in6_dev_put(idev); 205 } 206 207 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport) 208 { 209 struct sock *sk = skb->sk; 210 struct ipv6_pinfo *np = inet6_sk(sk); 211 struct flowi6 *fl6 = &transport->fl.u.ip6; 212 int res; 213 214 pr_debug("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n", __func__, skb, 215 skb->len, &fl6->saddr, &fl6->daddr); 216 217 IP6_ECN_flow_xmit(sk, fl6->flowlabel); 218 219 if (!(transport->param_flags & SPP_PMTUD_ENABLE)) 220 skb->ignore_df = 1; 221 222 SCTP_INC_STATS(sock_net(sk), SCTP_MIB_OUTSCTPPACKS); 223 224 rcu_read_lock(); 225 res = ip6_xmit(sk, skb, fl6, sk->sk_mark, rcu_dereference(np->opt), 226 np->tclass); 227 rcu_read_unlock(); 228 return res; 229 } 230 231 /* Returns the dst cache entry for the given source and destination ip 232 * addresses. 233 */ 234 static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr, 235 struct flowi *fl, struct sock *sk) 236 { 237 struct sctp_association *asoc = t->asoc; 238 struct dst_entry *dst = NULL; 239 struct flowi6 *fl6 = &fl->u.ip6; 240 struct sctp_bind_addr *bp; 241 struct ipv6_pinfo *np = inet6_sk(sk); 242 struct sctp_sockaddr_entry *laddr; 243 union sctp_addr *daddr = &t->ipaddr; 244 union sctp_addr dst_saddr; 245 struct in6_addr *final_p, final; 246 enum sctp_scope scope; 247 __u8 matchlen = 0; 248 249 memset(fl6, 0, sizeof(struct flowi6)); 250 fl6->daddr = daddr->v6.sin6_addr; 251 fl6->fl6_dport = daddr->v6.sin6_port; 252 fl6->flowi6_proto = IPPROTO_SCTP; 253 if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) 254 fl6->flowi6_oif = daddr->v6.sin6_scope_id; 255 else if (asoc) 256 fl6->flowi6_oif = asoc->base.sk->sk_bound_dev_if; 257 258 pr_debug("%s: dst=%pI6 ", __func__, &fl6->daddr); 259 260 if (asoc) 261 fl6->fl6_sport = htons(asoc->base.bind_addr.port); 262 263 if (saddr) { 264 fl6->saddr = saddr->v6.sin6_addr; 265 fl6->fl6_sport = saddr->v6.sin6_port; 266 267 pr_debug("src=%pI6 - ", &fl6->saddr); 268 } 269 270 rcu_read_lock(); 271 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final); 272 rcu_read_unlock(); 273 274 dst = ip6_dst_lookup_flow(sk, fl6, final_p); 275 if (!asoc || saddr) 276 goto out; 277 278 bp = &asoc->base.bind_addr; 279 scope = sctp_scope(daddr); 280 /* ip6_dst_lookup has filled in the fl6->saddr for us. Check 281 * to see if we can use it. 282 */ 283 if (!IS_ERR(dst)) { 284 /* Walk through the bind address list and look for a bind 285 * address that matches the source address of the returned dst. 286 */ 287 sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port)); 288 rcu_read_lock(); 289 list_for_each_entry_rcu(laddr, &bp->address_list, list) { 290 if (!laddr->valid || laddr->state == SCTP_ADDR_DEL || 291 (laddr->state != SCTP_ADDR_SRC && 292 !asoc->src_out_of_asoc_ok)) 293 continue; 294 295 /* Do not compare against v4 addrs */ 296 if ((laddr->a.sa.sa_family == AF_INET6) && 297 (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) { 298 rcu_read_unlock(); 299 goto out; 300 } 301 } 302 rcu_read_unlock(); 303 /* None of the bound addresses match the source address of the 304 * dst. So release it. 305 */ 306 dst_release(dst); 307 dst = NULL; 308 } 309 310 /* Walk through the bind address list and try to get the 311 * best source address for a given destination. 312 */ 313 rcu_read_lock(); 314 list_for_each_entry_rcu(laddr, &bp->address_list, list) { 315 struct dst_entry *bdst; 316 __u8 bmatchlen; 317 318 if (!laddr->valid || 319 laddr->state != SCTP_ADDR_SRC || 320 laddr->a.sa.sa_family != AF_INET6 || 321 scope > sctp_scope(&laddr->a)) 322 continue; 323 324 fl6->saddr = laddr->a.v6.sin6_addr; 325 fl6->fl6_sport = laddr->a.v6.sin6_port; 326 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final); 327 bdst = ip6_dst_lookup_flow(sk, fl6, final_p); 328 329 if (!IS_ERR(bdst) && 330 ipv6_chk_addr(dev_net(bdst->dev), 331 &laddr->a.v6.sin6_addr, bdst->dev, 1)) { 332 if (!IS_ERR_OR_NULL(dst)) 333 dst_release(dst); 334 dst = bdst; 335 break; 336 } 337 338 bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a); 339 if (matchlen > bmatchlen) 340 continue; 341 342 if (!IS_ERR_OR_NULL(dst)) 343 dst_release(dst); 344 dst = bdst; 345 matchlen = bmatchlen; 346 } 347 rcu_read_unlock(); 348 349 out: 350 if (!IS_ERR_OR_NULL(dst)) { 351 struct rt6_info *rt; 352 353 rt = (struct rt6_info *)dst; 354 t->dst = dst; 355 t->dst_cookie = rt6_get_cookie(rt); 356 pr_debug("rt6_dst:%pI6/%d rt6_src:%pI6\n", 357 &rt->rt6i_dst.addr, rt->rt6i_dst.plen, 358 &fl6->saddr); 359 } else { 360 t->dst = NULL; 361 362 pr_debug("no route\n"); 363 } 364 } 365 366 /* Returns the number of consecutive initial bits that match in the 2 ipv6 367 * addresses. 368 */ 369 static inline int sctp_v6_addr_match_len(union sctp_addr *s1, 370 union sctp_addr *s2) 371 { 372 return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr); 373 } 374 375 /* Fills in the source address(saddr) based on the destination address(daddr) 376 * and asoc's bind address list. 377 */ 378 static void sctp_v6_get_saddr(struct sctp_sock *sk, 379 struct sctp_transport *t, 380 struct flowi *fl) 381 { 382 struct flowi6 *fl6 = &fl->u.ip6; 383 union sctp_addr *saddr = &t->saddr; 384 385 pr_debug("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst); 386 387 if (t->dst) { 388 saddr->v6.sin6_family = AF_INET6; 389 saddr->v6.sin6_addr = fl6->saddr; 390 } 391 } 392 393 /* Make a copy of all potential local addresses. */ 394 static void sctp_v6_copy_addrlist(struct list_head *addrlist, 395 struct net_device *dev) 396 { 397 struct inet6_dev *in6_dev; 398 struct inet6_ifaddr *ifp; 399 struct sctp_sockaddr_entry *addr; 400 401 rcu_read_lock(); 402 if ((in6_dev = __in6_dev_get(dev)) == NULL) { 403 rcu_read_unlock(); 404 return; 405 } 406 407 read_lock_bh(&in6_dev->lock); 408 list_for_each_entry(ifp, &in6_dev->addr_list, if_list) { 409 /* Add the address to the local list. */ 410 addr = kzalloc(sizeof(*addr), GFP_ATOMIC); 411 if (addr) { 412 addr->a.v6.sin6_family = AF_INET6; 413 addr->a.v6.sin6_port = 0; 414 addr->a.v6.sin6_addr = ifp->addr; 415 addr->a.v6.sin6_scope_id = dev->ifindex; 416 addr->valid = 1; 417 INIT_LIST_HEAD(&addr->list); 418 list_add_tail(&addr->list, addrlist); 419 } 420 } 421 422 read_unlock_bh(&in6_dev->lock); 423 rcu_read_unlock(); 424 } 425 426 /* Initialize a sockaddr_storage from in incoming skb. */ 427 static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb, 428 int is_saddr) 429 { 430 /* Always called on head skb, so this is safe */ 431 struct sctphdr *sh = sctp_hdr(skb); 432 struct sockaddr_in6 *sa = &addr->v6; 433 434 addr->v6.sin6_family = AF_INET6; 435 addr->v6.sin6_flowinfo = 0; /* FIXME */ 436 addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif; 437 438 if (is_saddr) { 439 sa->sin6_port = sh->source; 440 sa->sin6_addr = ipv6_hdr(skb)->saddr; 441 } else { 442 sa->sin6_port = sh->dest; 443 sa->sin6_addr = ipv6_hdr(skb)->daddr; 444 } 445 } 446 447 /* Initialize an sctp_addr from a socket. */ 448 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk) 449 { 450 addr->v6.sin6_family = AF_INET6; 451 addr->v6.sin6_port = 0; 452 addr->v6.sin6_addr = sk->sk_v6_rcv_saddr; 453 } 454 455 /* Initialize sk->sk_rcv_saddr from sctp_addr. */ 456 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk) 457 { 458 if (addr->sa.sa_family == AF_INET) { 459 sk->sk_v6_rcv_saddr.s6_addr32[0] = 0; 460 sk->sk_v6_rcv_saddr.s6_addr32[1] = 0; 461 sk->sk_v6_rcv_saddr.s6_addr32[2] = htonl(0x0000ffff); 462 sk->sk_v6_rcv_saddr.s6_addr32[3] = 463 addr->v4.sin_addr.s_addr; 464 } else { 465 sk->sk_v6_rcv_saddr = addr->v6.sin6_addr; 466 } 467 } 468 469 /* Initialize sk->sk_daddr from sctp_addr. */ 470 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk) 471 { 472 if (addr->sa.sa_family == AF_INET) { 473 sk->sk_v6_daddr.s6_addr32[0] = 0; 474 sk->sk_v6_daddr.s6_addr32[1] = 0; 475 sk->sk_v6_daddr.s6_addr32[2] = htonl(0x0000ffff); 476 sk->sk_v6_daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr; 477 } else { 478 sk->sk_v6_daddr = addr->v6.sin6_addr; 479 } 480 } 481 482 /* Initialize a sctp_addr from an address parameter. */ 483 static void sctp_v6_from_addr_param(union sctp_addr *addr, 484 union sctp_addr_param *param, 485 __be16 port, int iif) 486 { 487 addr->v6.sin6_family = AF_INET6; 488 addr->v6.sin6_port = port; 489 addr->v6.sin6_flowinfo = 0; /* BUG */ 490 addr->v6.sin6_addr = param->v6.addr; 491 addr->v6.sin6_scope_id = iif; 492 } 493 494 /* Initialize an address parameter from a sctp_addr and return the length 495 * of the address parameter. 496 */ 497 static int sctp_v6_to_addr_param(const union sctp_addr *addr, 498 union sctp_addr_param *param) 499 { 500 int length = sizeof(struct sctp_ipv6addr_param); 501 502 param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS; 503 param->v6.param_hdr.length = htons(length); 504 param->v6.addr = addr->v6.sin6_addr; 505 506 return length; 507 } 508 509 /* Initialize a sctp_addr from struct in6_addr. */ 510 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr, 511 __be16 port) 512 { 513 addr->sa.sa_family = AF_INET6; 514 addr->v6.sin6_port = port; 515 addr->v6.sin6_flowinfo = 0; 516 addr->v6.sin6_addr = *saddr; 517 addr->v6.sin6_scope_id = 0; 518 } 519 520 /* Compare addresses exactly. 521 * v4-mapped-v6 is also in consideration. 522 */ 523 static int sctp_v6_cmp_addr(const union sctp_addr *addr1, 524 const union sctp_addr *addr2) 525 { 526 if (addr1->sa.sa_family != addr2->sa.sa_family) { 527 if (addr1->sa.sa_family == AF_INET && 528 addr2->sa.sa_family == AF_INET6 && 529 ipv6_addr_v4mapped(&addr2->v6.sin6_addr)) { 530 if (addr2->v6.sin6_port == addr1->v4.sin_port && 531 addr2->v6.sin6_addr.s6_addr32[3] == 532 addr1->v4.sin_addr.s_addr) 533 return 1; 534 } 535 if (addr2->sa.sa_family == AF_INET && 536 addr1->sa.sa_family == AF_INET6 && 537 ipv6_addr_v4mapped(&addr1->v6.sin6_addr)) { 538 if (addr1->v6.sin6_port == addr2->v4.sin_port && 539 addr1->v6.sin6_addr.s6_addr32[3] == 540 addr2->v4.sin_addr.s_addr) 541 return 1; 542 } 543 return 0; 544 } 545 if (addr1->v6.sin6_port != addr2->v6.sin6_port) 546 return 0; 547 if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr)) 548 return 0; 549 /* If this is a linklocal address, compare the scope_id. */ 550 if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) { 551 if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id && 552 (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) { 553 return 0; 554 } 555 } 556 557 return 1; 558 } 559 560 /* Initialize addr struct to INADDR_ANY. */ 561 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port) 562 { 563 memset(addr, 0x00, sizeof(union sctp_addr)); 564 addr->v6.sin6_family = AF_INET6; 565 addr->v6.sin6_port = port; 566 } 567 568 /* Is this a wildcard address? */ 569 static int sctp_v6_is_any(const union sctp_addr *addr) 570 { 571 return ipv6_addr_any(&addr->v6.sin6_addr); 572 } 573 574 /* Should this be available for binding? */ 575 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp) 576 { 577 int type; 578 struct net *net = sock_net(&sp->inet.sk); 579 const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr; 580 581 type = ipv6_addr_type(in6); 582 if (IPV6_ADDR_ANY == type) 583 return 1; 584 if (type == IPV6_ADDR_MAPPED) { 585 if (sp && ipv6_only_sock(sctp_opt2sk(sp))) 586 return 0; 587 sctp_v6_map_v4(addr); 588 return sctp_get_af_specific(AF_INET)->available(addr, sp); 589 } 590 if (!(type & IPV6_ADDR_UNICAST)) 591 return 0; 592 593 return sp->inet.freebind || net->ipv6.sysctl.ip_nonlocal_bind || 594 ipv6_chk_addr(net, in6, NULL, 0); 595 } 596 597 /* This function checks if the address is a valid address to be used for 598 * SCTP. 599 * 600 * Output: 601 * Return 0 - If the address is a non-unicast or an illegal address. 602 * Return 1 - If the address is a unicast. 603 */ 604 static int sctp_v6_addr_valid(union sctp_addr *addr, 605 struct sctp_sock *sp, 606 const struct sk_buff *skb) 607 { 608 int ret = ipv6_addr_type(&addr->v6.sin6_addr); 609 610 /* Support v4-mapped-v6 address. */ 611 if (ret == IPV6_ADDR_MAPPED) { 612 /* Note: This routine is used in input, so v4-mapped-v6 613 * are disallowed here when there is no sctp_sock. 614 */ 615 if (sp && ipv6_only_sock(sctp_opt2sk(sp))) 616 return 0; 617 sctp_v6_map_v4(addr); 618 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb); 619 } 620 621 /* Is this a non-unicast address */ 622 if (!(ret & IPV6_ADDR_UNICAST)) 623 return 0; 624 625 return 1; 626 } 627 628 /* What is the scope of 'addr'? */ 629 static enum sctp_scope sctp_v6_scope(union sctp_addr *addr) 630 { 631 enum sctp_scope retval; 632 int v6scope; 633 634 /* The IPv6 scope is really a set of bit fields. 635 * See IFA_* in <net/if_inet6.h>. Map to a generic SCTP scope. 636 */ 637 638 v6scope = ipv6_addr_scope(&addr->v6.sin6_addr); 639 switch (v6scope) { 640 case IFA_HOST: 641 retval = SCTP_SCOPE_LOOPBACK; 642 break; 643 case IFA_LINK: 644 retval = SCTP_SCOPE_LINK; 645 break; 646 case IFA_SITE: 647 retval = SCTP_SCOPE_PRIVATE; 648 break; 649 default: 650 retval = SCTP_SCOPE_GLOBAL; 651 break; 652 } 653 654 return retval; 655 } 656 657 /* Create and initialize a new sk for the socket to be returned by accept(). */ 658 static struct sock *sctp_v6_create_accept_sk(struct sock *sk, 659 struct sctp_association *asoc, 660 bool kern) 661 { 662 struct sock *newsk; 663 struct ipv6_pinfo *newnp, *np = inet6_sk(sk); 664 struct sctp6_sock *newsctp6sk; 665 struct ipv6_txoptions *opt; 666 667 newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot, kern); 668 if (!newsk) 669 goto out; 670 671 sock_init_data(NULL, newsk); 672 673 sctp_copy_sock(newsk, sk, asoc); 674 sock_reset_flag(sk, SOCK_ZAPPED); 675 676 newsctp6sk = (struct sctp6_sock *)newsk; 677 inet_sk(newsk)->pinet6 = &newsctp6sk->inet6; 678 679 sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped; 680 681 newnp = inet6_sk(newsk); 682 683 memcpy(newnp, np, sizeof(struct ipv6_pinfo)); 684 newnp->ipv6_mc_list = NULL; 685 newnp->ipv6_ac_list = NULL; 686 newnp->ipv6_fl_list = NULL; 687 688 rcu_read_lock(); 689 opt = rcu_dereference(np->opt); 690 if (opt) 691 opt = ipv6_dup_options(newsk, opt); 692 RCU_INIT_POINTER(newnp->opt, opt); 693 rcu_read_unlock(); 694 695 /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname() 696 * and getpeername(). 697 */ 698 sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk); 699 700 newsk->sk_v6_rcv_saddr = sk->sk_v6_rcv_saddr; 701 702 sk_refcnt_debug_inc(newsk); 703 704 if (newsk->sk_prot->init(newsk)) { 705 sk_common_release(newsk); 706 newsk = NULL; 707 } 708 709 out: 710 return newsk; 711 } 712 713 /* Format a sockaddr for return to user space. This makes sure the return is 714 * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option. 715 */ 716 static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr) 717 { 718 if (sp->v4mapped) { 719 if (addr->sa.sa_family == AF_INET) 720 sctp_v4_map_v6(addr); 721 } else { 722 if (addr->sa.sa_family == AF_INET6 && 723 ipv6_addr_v4mapped(&addr->v6.sin6_addr)) 724 sctp_v6_map_v4(addr); 725 } 726 727 if (addr->sa.sa_family == AF_INET) 728 return sizeof(struct sockaddr_in); 729 return sizeof(struct sockaddr_in6); 730 } 731 732 /* Where did this skb come from? */ 733 static int sctp_v6_skb_iif(const struct sk_buff *skb) 734 { 735 return IP6CB(skb)->iif; 736 } 737 738 /* Was this packet marked by Explicit Congestion Notification? */ 739 static int sctp_v6_is_ce(const struct sk_buff *skb) 740 { 741 return *((__u32 *)(ipv6_hdr(skb))) & (__force __u32)htonl(1 << 20); 742 } 743 744 /* Dump the v6 addr to the seq file. */ 745 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr) 746 { 747 seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr); 748 } 749 750 static void sctp_v6_ecn_capable(struct sock *sk) 751 { 752 inet6_sk(sk)->tclass |= INET_ECN_ECT_0; 753 } 754 755 /* Initialize a PF_INET msgname from a ulpevent. */ 756 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event, 757 char *msgname, int *addrlen) 758 { 759 union sctp_addr *addr; 760 struct sctp_association *asoc; 761 union sctp_addr *paddr; 762 763 if (!msgname) 764 return; 765 766 addr = (union sctp_addr *)msgname; 767 asoc = event->asoc; 768 paddr = &asoc->peer.primary_addr; 769 770 if (paddr->sa.sa_family == AF_INET) { 771 addr->v4.sin_family = AF_INET; 772 addr->v4.sin_port = htons(asoc->peer.port); 773 addr->v4.sin_addr = paddr->v4.sin_addr; 774 } else { 775 addr->v6.sin6_family = AF_INET6; 776 addr->v6.sin6_flowinfo = 0; 777 if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) 778 addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id; 779 else 780 addr->v6.sin6_scope_id = 0; 781 addr->v6.sin6_port = htons(asoc->peer.port); 782 addr->v6.sin6_addr = paddr->v6.sin6_addr; 783 } 784 785 *addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr); 786 } 787 788 /* Initialize a msg_name from an inbound skb. */ 789 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname, 790 int *addr_len) 791 { 792 union sctp_addr *addr; 793 struct sctphdr *sh; 794 795 if (!msgname) 796 return; 797 798 addr = (union sctp_addr *)msgname; 799 sh = sctp_hdr(skb); 800 801 if (ip_hdr(skb)->version == 4) { 802 addr->v4.sin_family = AF_INET; 803 addr->v4.sin_port = sh->source; 804 addr->v4.sin_addr.s_addr = ip_hdr(skb)->saddr; 805 } else { 806 addr->v6.sin6_family = AF_INET6; 807 addr->v6.sin6_flowinfo = 0; 808 addr->v6.sin6_port = sh->source; 809 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr; 810 if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) { 811 addr->v6.sin6_scope_id = sctp_v6_skb_iif(skb); 812 } 813 } 814 815 *addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr); 816 } 817 818 /* Do we support this AF? */ 819 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp) 820 { 821 switch (family) { 822 case AF_INET6: 823 return 1; 824 /* v4-mapped-v6 addresses */ 825 case AF_INET: 826 if (!__ipv6_only_sock(sctp_opt2sk(sp))) 827 return 1; 828 default: 829 return 0; 830 } 831 } 832 833 /* Address matching with wildcards allowed. This extra level 834 * of indirection lets us choose whether a PF_INET6 should 835 * disallow any v4 addresses if we so choose. 836 */ 837 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1, 838 const union sctp_addr *addr2, 839 struct sctp_sock *opt) 840 { 841 struct sctp_af *af1, *af2; 842 struct sock *sk = sctp_opt2sk(opt); 843 844 af1 = sctp_get_af_specific(addr1->sa.sa_family); 845 af2 = sctp_get_af_specific(addr2->sa.sa_family); 846 847 if (!af1 || !af2) 848 return 0; 849 850 /* If the socket is IPv6 only, v4 addrs will not match */ 851 if (__ipv6_only_sock(sk) && af1 != af2) 852 return 0; 853 854 /* Today, wildcard AF_INET/AF_INET6. */ 855 if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2)) 856 return 1; 857 858 if (addr1->sa.sa_family != addr2->sa.sa_family) 859 return 0; 860 861 return af1->cmp_addr(addr1, addr2); 862 } 863 864 /* Verify that the provided sockaddr looks bindable. Common verification, 865 * has already been taken care of. 866 */ 867 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr) 868 { 869 struct sctp_af *af; 870 871 /* ASSERT: address family has already been verified. */ 872 if (addr->sa.sa_family != AF_INET6) 873 af = sctp_get_af_specific(addr->sa.sa_family); 874 else { 875 int type = ipv6_addr_type(&addr->v6.sin6_addr); 876 struct net_device *dev; 877 878 if (type & IPV6_ADDR_LINKLOCAL) { 879 struct net *net; 880 if (!addr->v6.sin6_scope_id) 881 return 0; 882 net = sock_net(&opt->inet.sk); 883 rcu_read_lock(); 884 dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id); 885 if (!dev || !(opt->inet.freebind || 886 net->ipv6.sysctl.ip_nonlocal_bind || 887 ipv6_chk_addr(net, &addr->v6.sin6_addr, 888 dev, 0))) { 889 rcu_read_unlock(); 890 return 0; 891 } 892 rcu_read_unlock(); 893 } 894 895 af = opt->pf->af; 896 } 897 return af->available(addr, opt); 898 } 899 900 /* Verify that the provided sockaddr looks sendable. Common verification, 901 * has already been taken care of. 902 */ 903 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr) 904 { 905 struct sctp_af *af = NULL; 906 907 /* ASSERT: address family has already been verified. */ 908 if (addr->sa.sa_family != AF_INET6) 909 af = sctp_get_af_specific(addr->sa.sa_family); 910 else { 911 int type = ipv6_addr_type(&addr->v6.sin6_addr); 912 struct net_device *dev; 913 914 if (type & IPV6_ADDR_LINKLOCAL) { 915 if (!addr->v6.sin6_scope_id) 916 return 0; 917 rcu_read_lock(); 918 dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk), 919 addr->v6.sin6_scope_id); 920 rcu_read_unlock(); 921 if (!dev) 922 return 0; 923 } 924 af = opt->pf->af; 925 } 926 927 return af != NULL; 928 } 929 930 /* Fill in Supported Address Type information for INIT and INIT-ACK 931 * chunks. Note: In the future, we may want to look at sock options 932 * to determine whether a PF_INET6 socket really wants to have IPV4 933 * addresses. 934 * Returns number of addresses supported. 935 */ 936 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt, 937 __be16 *types) 938 { 939 types[0] = SCTP_PARAM_IPV6_ADDRESS; 940 if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) { 941 types[1] = SCTP_PARAM_IPV4_ADDRESS; 942 return 2; 943 } 944 return 1; 945 } 946 947 /* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */ 948 static int sctp_getname(struct socket *sock, struct sockaddr *uaddr, 949 int *uaddr_len, int peer) 950 { 951 int rc; 952 953 rc = inet6_getname(sock, uaddr, uaddr_len, peer); 954 955 if (rc != 0) 956 return rc; 957 958 *uaddr_len = sctp_v6_addr_to_user(sctp_sk(sock->sk), 959 (union sctp_addr *)uaddr); 960 961 return rc; 962 } 963 964 static const struct proto_ops inet6_seqpacket_ops = { 965 .family = PF_INET6, 966 .owner = THIS_MODULE, 967 .release = inet6_release, 968 .bind = inet6_bind, 969 .connect = inet_dgram_connect, 970 .socketpair = sock_no_socketpair, 971 .accept = inet_accept, 972 .getname = sctp_getname, 973 .poll = sctp_poll, 974 .ioctl = inet6_ioctl, 975 .listen = sctp_inet_listen, 976 .shutdown = inet_shutdown, 977 .setsockopt = sock_common_setsockopt, 978 .getsockopt = sock_common_getsockopt, 979 .sendmsg = inet_sendmsg, 980 .recvmsg = inet_recvmsg, 981 .mmap = sock_no_mmap, 982 #ifdef CONFIG_COMPAT 983 .compat_setsockopt = compat_sock_common_setsockopt, 984 .compat_getsockopt = compat_sock_common_getsockopt, 985 #endif 986 }; 987 988 static struct inet_protosw sctpv6_seqpacket_protosw = { 989 .type = SOCK_SEQPACKET, 990 .protocol = IPPROTO_SCTP, 991 .prot = &sctpv6_prot, 992 .ops = &inet6_seqpacket_ops, 993 .flags = SCTP_PROTOSW_FLAG 994 }; 995 static struct inet_protosw sctpv6_stream_protosw = { 996 .type = SOCK_STREAM, 997 .protocol = IPPROTO_SCTP, 998 .prot = &sctpv6_prot, 999 .ops = &inet6_seqpacket_ops, 1000 .flags = SCTP_PROTOSW_FLAG, 1001 }; 1002 1003 static int sctp6_rcv(struct sk_buff *skb) 1004 { 1005 return sctp_rcv(skb) ? -1 : 0; 1006 } 1007 1008 static const struct inet6_protocol sctpv6_protocol = { 1009 .handler = sctp6_rcv, 1010 .err_handler = sctp_v6_err, 1011 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL, 1012 }; 1013 1014 static struct sctp_af sctp_af_inet6 = { 1015 .sa_family = AF_INET6, 1016 .sctp_xmit = sctp_v6_xmit, 1017 .setsockopt = ipv6_setsockopt, 1018 .getsockopt = ipv6_getsockopt, 1019 .get_dst = sctp_v6_get_dst, 1020 .get_saddr = sctp_v6_get_saddr, 1021 .copy_addrlist = sctp_v6_copy_addrlist, 1022 .from_skb = sctp_v6_from_skb, 1023 .from_sk = sctp_v6_from_sk, 1024 .from_addr_param = sctp_v6_from_addr_param, 1025 .to_addr_param = sctp_v6_to_addr_param, 1026 .cmp_addr = sctp_v6_cmp_addr, 1027 .scope = sctp_v6_scope, 1028 .addr_valid = sctp_v6_addr_valid, 1029 .inaddr_any = sctp_v6_inaddr_any, 1030 .is_any = sctp_v6_is_any, 1031 .available = sctp_v6_available, 1032 .skb_iif = sctp_v6_skb_iif, 1033 .is_ce = sctp_v6_is_ce, 1034 .seq_dump_addr = sctp_v6_seq_dump_addr, 1035 .ecn_capable = sctp_v6_ecn_capable, 1036 .net_header_len = sizeof(struct ipv6hdr), 1037 .sockaddr_len = sizeof(struct sockaddr_in6), 1038 #ifdef CONFIG_COMPAT 1039 .compat_setsockopt = compat_ipv6_setsockopt, 1040 .compat_getsockopt = compat_ipv6_getsockopt, 1041 #endif 1042 }; 1043 1044 static struct sctp_pf sctp_pf_inet6 = { 1045 .event_msgname = sctp_inet6_event_msgname, 1046 .skb_msgname = sctp_inet6_skb_msgname, 1047 .af_supported = sctp_inet6_af_supported, 1048 .cmp_addr = sctp_inet6_cmp_addr, 1049 .bind_verify = sctp_inet6_bind_verify, 1050 .send_verify = sctp_inet6_send_verify, 1051 .supported_addrs = sctp_inet6_supported_addrs, 1052 .create_accept_sk = sctp_v6_create_accept_sk, 1053 .addr_to_user = sctp_v6_addr_to_user, 1054 .to_sk_saddr = sctp_v6_to_sk_saddr, 1055 .to_sk_daddr = sctp_v6_to_sk_daddr, 1056 .af = &sctp_af_inet6, 1057 }; 1058 1059 /* Initialize IPv6 support and register with socket layer. */ 1060 void sctp_v6_pf_init(void) 1061 { 1062 /* Register the SCTP specific PF_INET6 functions. */ 1063 sctp_register_pf(&sctp_pf_inet6, PF_INET6); 1064 1065 /* Register the SCTP specific AF_INET6 functions. */ 1066 sctp_register_af(&sctp_af_inet6); 1067 } 1068 1069 void sctp_v6_pf_exit(void) 1070 { 1071 list_del(&sctp_af_inet6.list); 1072 } 1073 1074 /* Initialize IPv6 support and register with socket layer. */ 1075 int sctp_v6_protosw_init(void) 1076 { 1077 int rc; 1078 1079 rc = proto_register(&sctpv6_prot, 1); 1080 if (rc) 1081 return rc; 1082 1083 /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */ 1084 inet6_register_protosw(&sctpv6_seqpacket_protosw); 1085 inet6_register_protosw(&sctpv6_stream_protosw); 1086 1087 return 0; 1088 } 1089 1090 void sctp_v6_protosw_exit(void) 1091 { 1092 inet6_unregister_protosw(&sctpv6_seqpacket_protosw); 1093 inet6_unregister_protosw(&sctpv6_stream_protosw); 1094 proto_unregister(&sctpv6_prot); 1095 } 1096 1097 1098 /* Register with inet6 layer. */ 1099 int sctp_v6_add_protocol(void) 1100 { 1101 /* Register notifier for inet6 address additions/deletions. */ 1102 register_inet6addr_notifier(&sctp_inet6addr_notifier); 1103 1104 if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0) 1105 return -EAGAIN; 1106 1107 return 0; 1108 } 1109 1110 /* Unregister with inet6 layer. */ 1111 void sctp_v6_del_protocol(void) 1112 { 1113 inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP); 1114 unregister_inet6addr_notifier(&sctp_inet6addr_notifier); 1115 } 1116