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 = kzalloc(sizeof(*addr), GFP_ATOMIC); 101 if (addr) { 102 addr->a.v6.sin6_family = AF_INET6; 103 addr->a.v6.sin6_addr = ifa->addr; 104 addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex; 105 addr->valid = 1; 106 spin_lock_bh(&net->sctp.local_addr_lock); 107 list_add_tail_rcu(&addr->list, &net->sctp.local_addr_list); 108 sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_NEW); 109 spin_unlock_bh(&net->sctp.local_addr_lock); 110 } 111 break; 112 case NETDEV_DOWN: 113 spin_lock_bh(&net->sctp.local_addr_lock); 114 list_for_each_entry_safe(addr, temp, 115 &net->sctp.local_addr_list, list) { 116 if (addr->a.sa.sa_family == AF_INET6 && 117 ipv6_addr_equal(&addr->a.v6.sin6_addr, 118 &ifa->addr)) { 119 sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL); 120 found = 1; 121 addr->valid = 0; 122 list_del_rcu(&addr->list); 123 break; 124 } 125 } 126 spin_unlock_bh(&net->sctp.local_addr_lock); 127 if (found) 128 kfree_rcu(addr, rcu); 129 break; 130 } 131 132 return NOTIFY_DONE; 133 } 134 135 static struct notifier_block sctp_inet6addr_notifier = { 136 .notifier_call = sctp_inet6addr_event, 137 }; 138 139 /* ICMP error handler. */ 140 static int sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 141 u8 type, u8 code, int offset, __be32 info) 142 { 143 struct inet6_dev *idev; 144 struct sock *sk; 145 struct sctp_association *asoc; 146 struct sctp_transport *transport; 147 struct ipv6_pinfo *np; 148 __u16 saveip, savesctp; 149 int err, ret = 0; 150 struct net *net = dev_net(skb->dev); 151 152 idev = in6_dev_get(skb->dev); 153 154 /* Fix up skb to look at the embedded net header. */ 155 saveip = skb->network_header; 156 savesctp = skb->transport_header; 157 skb_reset_network_header(skb); 158 skb_set_transport_header(skb, offset); 159 sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &transport); 160 /* Put back, the original pointers. */ 161 skb->network_header = saveip; 162 skb->transport_header = savesctp; 163 if (!sk) { 164 __ICMP6_INC_STATS(net, idev, ICMP6_MIB_INERRORS); 165 ret = -ENOENT; 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 return ret; 207 } 208 209 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport) 210 { 211 struct sock *sk = skb->sk; 212 struct ipv6_pinfo *np = inet6_sk(sk); 213 struct flowi6 *fl6 = &transport->fl.u.ip6; 214 __u8 tclass = np->tclass; 215 int res; 216 217 pr_debug("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n", __func__, skb, 218 skb->len, &fl6->saddr, &fl6->daddr); 219 220 if (transport->dscp & SCTP_DSCP_SET_MASK) 221 tclass = transport->dscp & SCTP_DSCP_VAL_MASK; 222 223 if (INET_ECN_is_capable(tclass)) 224 IP6_ECN_flow_xmit(sk, fl6->flowlabel); 225 226 if (!(transport->param_flags & SPP_PMTUD_ENABLE)) 227 skb->ignore_df = 1; 228 229 SCTP_INC_STATS(sock_net(sk), SCTP_MIB_OUTSCTPPACKS); 230 231 rcu_read_lock(); 232 res = ip6_xmit(sk, skb, fl6, sk->sk_mark, rcu_dereference(np->opt), 233 tclass); 234 rcu_read_unlock(); 235 return res; 236 } 237 238 /* Returns the dst cache entry for the given source and destination ip 239 * addresses. 240 */ 241 static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr, 242 struct flowi *fl, struct sock *sk) 243 { 244 struct sctp_association *asoc = t->asoc; 245 struct dst_entry *dst = NULL; 246 struct flowi6 *fl6 = &fl->u.ip6; 247 struct sctp_bind_addr *bp; 248 struct ipv6_pinfo *np = inet6_sk(sk); 249 struct sctp_sockaddr_entry *laddr; 250 union sctp_addr *daddr = &t->ipaddr; 251 union sctp_addr dst_saddr; 252 struct in6_addr *final_p, final; 253 enum sctp_scope scope; 254 __u8 matchlen = 0; 255 256 memset(fl6, 0, sizeof(struct flowi6)); 257 fl6->daddr = daddr->v6.sin6_addr; 258 fl6->fl6_dport = daddr->v6.sin6_port; 259 fl6->flowi6_proto = IPPROTO_SCTP; 260 if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) 261 fl6->flowi6_oif = daddr->v6.sin6_scope_id; 262 else if (asoc) 263 fl6->flowi6_oif = asoc->base.sk->sk_bound_dev_if; 264 if (t->flowlabel & SCTP_FLOWLABEL_SET_MASK) 265 fl6->flowlabel = htonl(t->flowlabel & SCTP_FLOWLABEL_VAL_MASK); 266 267 if (np->sndflow && (fl6->flowlabel & IPV6_FLOWLABEL_MASK)) { 268 struct ip6_flowlabel *flowlabel; 269 270 flowlabel = fl6_sock_lookup(sk, fl6->flowlabel); 271 if (!flowlabel) 272 goto out; 273 fl6_sock_release(flowlabel); 274 } 275 276 pr_debug("%s: dst=%pI6 ", __func__, &fl6->daddr); 277 278 if (asoc) 279 fl6->fl6_sport = htons(asoc->base.bind_addr.port); 280 281 if (saddr) { 282 fl6->saddr = saddr->v6.sin6_addr; 283 if (!fl6->fl6_sport) 284 fl6->fl6_sport = saddr->v6.sin6_port; 285 286 pr_debug("src=%pI6 - ", &fl6->saddr); 287 } 288 289 rcu_read_lock(); 290 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final); 291 rcu_read_unlock(); 292 293 dst = ip6_dst_lookup_flow(sk, fl6, final_p); 294 if (!asoc || saddr) 295 goto out; 296 297 bp = &asoc->base.bind_addr; 298 scope = sctp_scope(daddr); 299 /* ip6_dst_lookup has filled in the fl6->saddr for us. Check 300 * to see if we can use it. 301 */ 302 if (!IS_ERR(dst)) { 303 /* Walk through the bind address list and look for a bind 304 * address that matches the source address of the returned dst. 305 */ 306 sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port)); 307 rcu_read_lock(); 308 list_for_each_entry_rcu(laddr, &bp->address_list, list) { 309 if (!laddr->valid || laddr->state == SCTP_ADDR_DEL || 310 (laddr->state != SCTP_ADDR_SRC && 311 !asoc->src_out_of_asoc_ok)) 312 continue; 313 314 /* Do not compare against v4 addrs */ 315 if ((laddr->a.sa.sa_family == AF_INET6) && 316 (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) { 317 rcu_read_unlock(); 318 goto out; 319 } 320 } 321 rcu_read_unlock(); 322 /* None of the bound addresses match the source address of the 323 * dst. So release it. 324 */ 325 dst_release(dst); 326 dst = NULL; 327 } 328 329 /* Walk through the bind address list and try to get the 330 * best source address for a given destination. 331 */ 332 rcu_read_lock(); 333 list_for_each_entry_rcu(laddr, &bp->address_list, list) { 334 struct dst_entry *bdst; 335 __u8 bmatchlen; 336 337 if (!laddr->valid || 338 laddr->state != SCTP_ADDR_SRC || 339 laddr->a.sa.sa_family != AF_INET6 || 340 scope > sctp_scope(&laddr->a)) 341 continue; 342 343 fl6->saddr = laddr->a.v6.sin6_addr; 344 fl6->fl6_sport = laddr->a.v6.sin6_port; 345 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final); 346 bdst = ip6_dst_lookup_flow(sk, fl6, final_p); 347 348 if (IS_ERR(bdst)) 349 continue; 350 351 if (ipv6_chk_addr(dev_net(bdst->dev), 352 &laddr->a.v6.sin6_addr, bdst->dev, 1)) { 353 if (!IS_ERR_OR_NULL(dst)) 354 dst_release(dst); 355 dst = bdst; 356 break; 357 } 358 359 bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a); 360 if (matchlen > bmatchlen) { 361 dst_release(bdst); 362 continue; 363 } 364 365 if (!IS_ERR_OR_NULL(dst)) 366 dst_release(dst); 367 dst = bdst; 368 matchlen = bmatchlen; 369 } 370 rcu_read_unlock(); 371 372 out: 373 if (!IS_ERR_OR_NULL(dst)) { 374 struct rt6_info *rt; 375 376 rt = (struct rt6_info *)dst; 377 t->dst = dst; 378 t->dst_cookie = rt6_get_cookie(rt); 379 pr_debug("rt6_dst:%pI6/%d rt6_src:%pI6\n", 380 &rt->rt6i_dst.addr, rt->rt6i_dst.plen, 381 &fl6->saddr); 382 } else { 383 t->dst = NULL; 384 385 pr_debug("no route\n"); 386 } 387 } 388 389 /* Returns the number of consecutive initial bits that match in the 2 ipv6 390 * addresses. 391 */ 392 static inline int sctp_v6_addr_match_len(union sctp_addr *s1, 393 union sctp_addr *s2) 394 { 395 return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr); 396 } 397 398 /* Fills in the source address(saddr) based on the destination address(daddr) 399 * and asoc's bind address list. 400 */ 401 static void sctp_v6_get_saddr(struct sctp_sock *sk, 402 struct sctp_transport *t, 403 struct flowi *fl) 404 { 405 struct flowi6 *fl6 = &fl->u.ip6; 406 union sctp_addr *saddr = &t->saddr; 407 408 pr_debug("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst); 409 410 if (t->dst) { 411 saddr->v6.sin6_family = AF_INET6; 412 saddr->v6.sin6_addr = fl6->saddr; 413 } 414 } 415 416 /* Make a copy of all potential local addresses. */ 417 static void sctp_v6_copy_addrlist(struct list_head *addrlist, 418 struct net_device *dev) 419 { 420 struct inet6_dev *in6_dev; 421 struct inet6_ifaddr *ifp; 422 struct sctp_sockaddr_entry *addr; 423 424 rcu_read_lock(); 425 if ((in6_dev = __in6_dev_get(dev)) == NULL) { 426 rcu_read_unlock(); 427 return; 428 } 429 430 read_lock_bh(&in6_dev->lock); 431 list_for_each_entry(ifp, &in6_dev->addr_list, if_list) { 432 /* Add the address to the local list. */ 433 addr = kzalloc(sizeof(*addr), GFP_ATOMIC); 434 if (addr) { 435 addr->a.v6.sin6_family = AF_INET6; 436 addr->a.v6.sin6_addr = ifp->addr; 437 addr->a.v6.sin6_scope_id = dev->ifindex; 438 addr->valid = 1; 439 INIT_LIST_HEAD(&addr->list); 440 list_add_tail(&addr->list, addrlist); 441 } 442 } 443 444 read_unlock_bh(&in6_dev->lock); 445 rcu_read_unlock(); 446 } 447 448 /* Copy over any ip options */ 449 static void sctp_v6_copy_ip_options(struct sock *sk, struct sock *newsk) 450 { 451 struct ipv6_pinfo *newnp, *np = inet6_sk(sk); 452 struct ipv6_txoptions *opt; 453 454 newnp = inet6_sk(newsk); 455 456 rcu_read_lock(); 457 opt = rcu_dereference(np->opt); 458 if (opt) { 459 opt = ipv6_dup_options(newsk, opt); 460 if (!opt) 461 pr_err("%s: Failed to copy ip options\n", __func__); 462 } 463 RCU_INIT_POINTER(newnp->opt, opt); 464 rcu_read_unlock(); 465 } 466 467 /* Account for the IP options */ 468 static int sctp_v6_ip_options_len(struct sock *sk) 469 { 470 struct ipv6_pinfo *np = inet6_sk(sk); 471 struct ipv6_txoptions *opt; 472 int len = 0; 473 474 rcu_read_lock(); 475 opt = rcu_dereference(np->opt); 476 if (opt) 477 len = opt->opt_flen + opt->opt_nflen; 478 479 rcu_read_unlock(); 480 return len; 481 } 482 483 /* Initialize a sockaddr_storage from in incoming skb. */ 484 static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb, 485 int is_saddr) 486 { 487 /* Always called on head skb, so this is safe */ 488 struct sctphdr *sh = sctp_hdr(skb); 489 struct sockaddr_in6 *sa = &addr->v6; 490 491 addr->v6.sin6_family = AF_INET6; 492 addr->v6.sin6_flowinfo = 0; /* FIXME */ 493 addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif; 494 495 if (is_saddr) { 496 sa->sin6_port = sh->source; 497 sa->sin6_addr = ipv6_hdr(skb)->saddr; 498 } else { 499 sa->sin6_port = sh->dest; 500 sa->sin6_addr = ipv6_hdr(skb)->daddr; 501 } 502 } 503 504 /* Initialize an sctp_addr from a socket. */ 505 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk) 506 { 507 addr->v6.sin6_family = AF_INET6; 508 addr->v6.sin6_port = 0; 509 addr->v6.sin6_addr = sk->sk_v6_rcv_saddr; 510 } 511 512 /* Initialize sk->sk_rcv_saddr from sctp_addr. */ 513 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk) 514 { 515 if (addr->sa.sa_family == AF_INET) { 516 sk->sk_v6_rcv_saddr.s6_addr32[0] = 0; 517 sk->sk_v6_rcv_saddr.s6_addr32[1] = 0; 518 sk->sk_v6_rcv_saddr.s6_addr32[2] = htonl(0x0000ffff); 519 sk->sk_v6_rcv_saddr.s6_addr32[3] = 520 addr->v4.sin_addr.s_addr; 521 } else { 522 sk->sk_v6_rcv_saddr = addr->v6.sin6_addr; 523 } 524 } 525 526 /* Initialize sk->sk_daddr from sctp_addr. */ 527 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk) 528 { 529 if (addr->sa.sa_family == AF_INET) { 530 sk->sk_v6_daddr.s6_addr32[0] = 0; 531 sk->sk_v6_daddr.s6_addr32[1] = 0; 532 sk->sk_v6_daddr.s6_addr32[2] = htonl(0x0000ffff); 533 sk->sk_v6_daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr; 534 } else { 535 sk->sk_v6_daddr = addr->v6.sin6_addr; 536 } 537 } 538 539 /* Initialize a sctp_addr from an address parameter. */ 540 static void sctp_v6_from_addr_param(union sctp_addr *addr, 541 union sctp_addr_param *param, 542 __be16 port, int iif) 543 { 544 addr->v6.sin6_family = AF_INET6; 545 addr->v6.sin6_port = port; 546 addr->v6.sin6_flowinfo = 0; /* BUG */ 547 addr->v6.sin6_addr = param->v6.addr; 548 addr->v6.sin6_scope_id = iif; 549 } 550 551 /* Initialize an address parameter from a sctp_addr and return the length 552 * of the address parameter. 553 */ 554 static int sctp_v6_to_addr_param(const union sctp_addr *addr, 555 union sctp_addr_param *param) 556 { 557 int length = sizeof(struct sctp_ipv6addr_param); 558 559 param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS; 560 param->v6.param_hdr.length = htons(length); 561 param->v6.addr = addr->v6.sin6_addr; 562 563 return length; 564 } 565 566 /* Initialize a sctp_addr from struct in6_addr. */ 567 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr, 568 __be16 port) 569 { 570 addr->sa.sa_family = AF_INET6; 571 addr->v6.sin6_port = port; 572 addr->v6.sin6_flowinfo = 0; 573 addr->v6.sin6_addr = *saddr; 574 addr->v6.sin6_scope_id = 0; 575 } 576 577 static int __sctp_v6_cmp_addr(const union sctp_addr *addr1, 578 const union sctp_addr *addr2) 579 { 580 if (addr1->sa.sa_family != addr2->sa.sa_family) { 581 if (addr1->sa.sa_family == AF_INET && 582 addr2->sa.sa_family == AF_INET6 && 583 ipv6_addr_v4mapped(&addr2->v6.sin6_addr) && 584 addr2->v6.sin6_addr.s6_addr32[3] == 585 addr1->v4.sin_addr.s_addr) 586 return 1; 587 588 if (addr2->sa.sa_family == AF_INET && 589 addr1->sa.sa_family == AF_INET6 && 590 ipv6_addr_v4mapped(&addr1->v6.sin6_addr) && 591 addr1->v6.sin6_addr.s6_addr32[3] == 592 addr2->v4.sin_addr.s_addr) 593 return 1; 594 595 return 0; 596 } 597 598 if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr)) 599 return 0; 600 601 /* If this is a linklocal address, compare the scope_id. */ 602 if ((ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) && 603 addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id && 604 addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id) 605 return 0; 606 607 return 1; 608 } 609 610 /* Compare addresses exactly. 611 * v4-mapped-v6 is also in consideration. 612 */ 613 static int sctp_v6_cmp_addr(const union sctp_addr *addr1, 614 const union sctp_addr *addr2) 615 { 616 return __sctp_v6_cmp_addr(addr1, addr2) && 617 addr1->v6.sin6_port == addr2->v6.sin6_port; 618 } 619 620 /* Initialize addr struct to INADDR_ANY. */ 621 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port) 622 { 623 memset(addr, 0x00, sizeof(union sctp_addr)); 624 addr->v6.sin6_family = AF_INET6; 625 addr->v6.sin6_port = port; 626 } 627 628 /* Is this a wildcard address? */ 629 static int sctp_v6_is_any(const union sctp_addr *addr) 630 { 631 return ipv6_addr_any(&addr->v6.sin6_addr); 632 } 633 634 /* Should this be available for binding? */ 635 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp) 636 { 637 int type; 638 struct net *net = sock_net(&sp->inet.sk); 639 const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr; 640 641 type = ipv6_addr_type(in6); 642 if (IPV6_ADDR_ANY == type) 643 return 1; 644 if (type == IPV6_ADDR_MAPPED) { 645 if (sp && ipv6_only_sock(sctp_opt2sk(sp))) 646 return 0; 647 sctp_v6_map_v4(addr); 648 return sctp_get_af_specific(AF_INET)->available(addr, sp); 649 } 650 if (!(type & IPV6_ADDR_UNICAST)) 651 return 0; 652 653 return sp->inet.freebind || net->ipv6.sysctl.ip_nonlocal_bind || 654 ipv6_chk_addr(net, in6, NULL, 0); 655 } 656 657 /* This function checks if the address is a valid address to be used for 658 * SCTP. 659 * 660 * Output: 661 * Return 0 - If the address is a non-unicast or an illegal address. 662 * Return 1 - If the address is a unicast. 663 */ 664 static int sctp_v6_addr_valid(union sctp_addr *addr, 665 struct sctp_sock *sp, 666 const struct sk_buff *skb) 667 { 668 int ret = ipv6_addr_type(&addr->v6.sin6_addr); 669 670 /* Support v4-mapped-v6 address. */ 671 if (ret == IPV6_ADDR_MAPPED) { 672 /* Note: This routine is used in input, so v4-mapped-v6 673 * are disallowed here when there is no sctp_sock. 674 */ 675 if (sp && ipv6_only_sock(sctp_opt2sk(sp))) 676 return 0; 677 sctp_v6_map_v4(addr); 678 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb); 679 } 680 681 /* Is this a non-unicast address */ 682 if (!(ret & IPV6_ADDR_UNICAST)) 683 return 0; 684 685 return 1; 686 } 687 688 /* What is the scope of 'addr'? */ 689 static enum sctp_scope sctp_v6_scope(union sctp_addr *addr) 690 { 691 enum sctp_scope retval; 692 int v6scope; 693 694 /* The IPv6 scope is really a set of bit fields. 695 * See IFA_* in <net/if_inet6.h>. Map to a generic SCTP scope. 696 */ 697 698 v6scope = ipv6_addr_scope(&addr->v6.sin6_addr); 699 switch (v6scope) { 700 case IFA_HOST: 701 retval = SCTP_SCOPE_LOOPBACK; 702 break; 703 case IFA_LINK: 704 retval = SCTP_SCOPE_LINK; 705 break; 706 case IFA_SITE: 707 retval = SCTP_SCOPE_PRIVATE; 708 break; 709 default: 710 retval = SCTP_SCOPE_GLOBAL; 711 break; 712 } 713 714 return retval; 715 } 716 717 /* Create and initialize a new sk for the socket to be returned by accept(). */ 718 static struct sock *sctp_v6_create_accept_sk(struct sock *sk, 719 struct sctp_association *asoc, 720 bool kern) 721 { 722 struct sock *newsk; 723 struct ipv6_pinfo *newnp, *np = inet6_sk(sk); 724 struct sctp6_sock *newsctp6sk; 725 726 newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot, kern); 727 if (!newsk) 728 goto out; 729 730 sock_init_data(NULL, newsk); 731 732 sctp_copy_sock(newsk, sk, asoc); 733 sock_reset_flag(sk, SOCK_ZAPPED); 734 735 newsctp6sk = (struct sctp6_sock *)newsk; 736 inet_sk(newsk)->pinet6 = &newsctp6sk->inet6; 737 738 sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped; 739 740 newnp = inet6_sk(newsk); 741 742 memcpy(newnp, np, sizeof(struct ipv6_pinfo)); 743 newnp->ipv6_mc_list = NULL; 744 newnp->ipv6_ac_list = NULL; 745 newnp->ipv6_fl_list = NULL; 746 747 sctp_v6_copy_ip_options(sk, newsk); 748 749 /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname() 750 * and getpeername(). 751 */ 752 sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk); 753 754 newsk->sk_v6_rcv_saddr = sk->sk_v6_rcv_saddr; 755 756 sk_refcnt_debug_inc(newsk); 757 758 if (newsk->sk_prot->init(newsk)) { 759 sk_common_release(newsk); 760 newsk = NULL; 761 } 762 763 out: 764 return newsk; 765 } 766 767 /* Format a sockaddr for return to user space. This makes sure the return is 768 * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option. 769 */ 770 static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr) 771 { 772 if (sp->v4mapped) { 773 if (addr->sa.sa_family == AF_INET) 774 sctp_v4_map_v6(addr); 775 } else { 776 if (addr->sa.sa_family == AF_INET6 && 777 ipv6_addr_v4mapped(&addr->v6.sin6_addr)) 778 sctp_v6_map_v4(addr); 779 } 780 781 if (addr->sa.sa_family == AF_INET) { 782 memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero)); 783 return sizeof(struct sockaddr_in); 784 } 785 return sizeof(struct sockaddr_in6); 786 } 787 788 /* Where did this skb come from? */ 789 static int sctp_v6_skb_iif(const struct sk_buff *skb) 790 { 791 return IP6CB(skb)->iif; 792 } 793 794 /* Was this packet marked by Explicit Congestion Notification? */ 795 static int sctp_v6_is_ce(const struct sk_buff *skb) 796 { 797 return *((__u32 *)(ipv6_hdr(skb))) & (__force __u32)htonl(1 << 20); 798 } 799 800 /* Dump the v6 addr to the seq file. */ 801 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr) 802 { 803 seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr); 804 } 805 806 static void sctp_v6_ecn_capable(struct sock *sk) 807 { 808 inet6_sk(sk)->tclass |= INET_ECN_ECT_0; 809 } 810 811 /* Initialize a PF_INET msgname from a ulpevent. */ 812 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event, 813 char *msgname, int *addrlen) 814 { 815 union sctp_addr *addr; 816 struct sctp_association *asoc; 817 union sctp_addr *paddr; 818 819 if (!msgname) 820 return; 821 822 addr = (union sctp_addr *)msgname; 823 asoc = event->asoc; 824 paddr = &asoc->peer.primary_addr; 825 826 if (paddr->sa.sa_family == AF_INET) { 827 addr->v4.sin_family = AF_INET; 828 addr->v4.sin_port = htons(asoc->peer.port); 829 addr->v4.sin_addr = paddr->v4.sin_addr; 830 } else { 831 addr->v6.sin6_family = AF_INET6; 832 addr->v6.sin6_flowinfo = 0; 833 if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) 834 addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id; 835 else 836 addr->v6.sin6_scope_id = 0; 837 addr->v6.sin6_port = htons(asoc->peer.port); 838 addr->v6.sin6_addr = paddr->v6.sin6_addr; 839 } 840 841 *addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr); 842 } 843 844 /* Initialize a msg_name from an inbound skb. */ 845 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname, 846 int *addr_len) 847 { 848 union sctp_addr *addr; 849 struct sctphdr *sh; 850 851 if (!msgname) 852 return; 853 854 addr = (union sctp_addr *)msgname; 855 sh = sctp_hdr(skb); 856 857 if (ip_hdr(skb)->version == 4) { 858 addr->v4.sin_family = AF_INET; 859 addr->v4.sin_port = sh->source; 860 addr->v4.sin_addr.s_addr = ip_hdr(skb)->saddr; 861 } else { 862 addr->v6.sin6_family = AF_INET6; 863 addr->v6.sin6_flowinfo = 0; 864 addr->v6.sin6_port = sh->source; 865 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr; 866 if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) 867 addr->v6.sin6_scope_id = sctp_v6_skb_iif(skb); 868 else 869 addr->v6.sin6_scope_id = 0; 870 } 871 872 *addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr); 873 } 874 875 /* Do we support this AF? */ 876 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp) 877 { 878 switch (family) { 879 case AF_INET6: 880 return 1; 881 /* v4-mapped-v6 addresses */ 882 case AF_INET: 883 if (!__ipv6_only_sock(sctp_opt2sk(sp))) 884 return 1; 885 /* fallthru */ 886 default: 887 return 0; 888 } 889 } 890 891 /* Address matching with wildcards allowed. This extra level 892 * of indirection lets us choose whether a PF_INET6 should 893 * disallow any v4 addresses if we so choose. 894 */ 895 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1, 896 const union sctp_addr *addr2, 897 struct sctp_sock *opt) 898 { 899 struct sock *sk = sctp_opt2sk(opt); 900 struct sctp_af *af1, *af2; 901 902 af1 = sctp_get_af_specific(addr1->sa.sa_family); 903 af2 = sctp_get_af_specific(addr2->sa.sa_family); 904 905 if (!af1 || !af2) 906 return 0; 907 908 /* If the socket is IPv6 only, v4 addrs will not match */ 909 if (__ipv6_only_sock(sk) && af1 != af2) 910 return 0; 911 912 /* Today, wildcard AF_INET/AF_INET6. */ 913 if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2)) 914 return 1; 915 916 if (addr1->sa.sa_family == AF_INET && addr2->sa.sa_family == AF_INET) 917 return addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr; 918 919 return __sctp_v6_cmp_addr(addr1, addr2); 920 } 921 922 /* Verify that the provided sockaddr looks bindable. Common verification, 923 * has already been taken care of. 924 */ 925 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr) 926 { 927 struct sctp_af *af; 928 929 /* ASSERT: address family has already been verified. */ 930 if (addr->sa.sa_family != AF_INET6) 931 af = sctp_get_af_specific(addr->sa.sa_family); 932 else { 933 int type = ipv6_addr_type(&addr->v6.sin6_addr); 934 struct net_device *dev; 935 936 if (type & IPV6_ADDR_LINKLOCAL) { 937 struct net *net; 938 if (!addr->v6.sin6_scope_id) 939 return 0; 940 net = sock_net(&opt->inet.sk); 941 rcu_read_lock(); 942 dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id); 943 if (!dev || !(opt->inet.freebind || 944 net->ipv6.sysctl.ip_nonlocal_bind || 945 ipv6_chk_addr(net, &addr->v6.sin6_addr, 946 dev, 0))) { 947 rcu_read_unlock(); 948 return 0; 949 } 950 rcu_read_unlock(); 951 } 952 953 af = opt->pf->af; 954 } 955 return af->available(addr, opt); 956 } 957 958 /* Verify that the provided sockaddr looks sendable. Common verification, 959 * has already been taken care of. 960 */ 961 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr) 962 { 963 struct sctp_af *af = NULL; 964 965 /* ASSERT: address family has already been verified. */ 966 if (addr->sa.sa_family != AF_INET6) 967 af = sctp_get_af_specific(addr->sa.sa_family); 968 else { 969 int type = ipv6_addr_type(&addr->v6.sin6_addr); 970 struct net_device *dev; 971 972 if (type & IPV6_ADDR_LINKLOCAL) { 973 if (!addr->v6.sin6_scope_id) 974 return 0; 975 rcu_read_lock(); 976 dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk), 977 addr->v6.sin6_scope_id); 978 rcu_read_unlock(); 979 if (!dev) 980 return 0; 981 } 982 af = opt->pf->af; 983 } 984 985 return af != NULL; 986 } 987 988 /* Fill in Supported Address Type information for INIT and INIT-ACK 989 * chunks. Note: In the future, we may want to look at sock options 990 * to determine whether a PF_INET6 socket really wants to have IPV4 991 * addresses. 992 * Returns number of addresses supported. 993 */ 994 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt, 995 __be16 *types) 996 { 997 types[0] = SCTP_PARAM_IPV6_ADDRESS; 998 if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) { 999 types[1] = SCTP_PARAM_IPV4_ADDRESS; 1000 return 2; 1001 } 1002 return 1; 1003 } 1004 1005 /* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */ 1006 static int sctp_getname(struct socket *sock, struct sockaddr *uaddr, 1007 int peer) 1008 { 1009 int rc; 1010 1011 rc = inet6_getname(sock, uaddr, peer); 1012 1013 if (rc < 0) 1014 return rc; 1015 1016 rc = sctp_v6_addr_to_user(sctp_sk(sock->sk), 1017 (union sctp_addr *)uaddr); 1018 1019 return rc; 1020 } 1021 1022 static const struct proto_ops inet6_seqpacket_ops = { 1023 .family = PF_INET6, 1024 .owner = THIS_MODULE, 1025 .release = inet6_release, 1026 .bind = inet6_bind, 1027 .connect = sctp_inet_connect, 1028 .socketpair = sock_no_socketpair, 1029 .accept = inet_accept, 1030 .getname = sctp_getname, 1031 .poll = sctp_poll, 1032 .ioctl = inet6_ioctl, 1033 .listen = sctp_inet_listen, 1034 .shutdown = inet_shutdown, 1035 .setsockopt = sock_common_setsockopt, 1036 .getsockopt = sock_common_getsockopt, 1037 .sendmsg = inet_sendmsg, 1038 .recvmsg = inet_recvmsg, 1039 .mmap = sock_no_mmap, 1040 #ifdef CONFIG_COMPAT 1041 .compat_setsockopt = compat_sock_common_setsockopt, 1042 .compat_getsockopt = compat_sock_common_getsockopt, 1043 #endif 1044 }; 1045 1046 static struct inet_protosw sctpv6_seqpacket_protosw = { 1047 .type = SOCK_SEQPACKET, 1048 .protocol = IPPROTO_SCTP, 1049 .prot = &sctpv6_prot, 1050 .ops = &inet6_seqpacket_ops, 1051 .flags = SCTP_PROTOSW_FLAG 1052 }; 1053 static struct inet_protosw sctpv6_stream_protosw = { 1054 .type = SOCK_STREAM, 1055 .protocol = IPPROTO_SCTP, 1056 .prot = &sctpv6_prot, 1057 .ops = &inet6_seqpacket_ops, 1058 .flags = SCTP_PROTOSW_FLAG, 1059 }; 1060 1061 static int sctp6_rcv(struct sk_buff *skb) 1062 { 1063 return sctp_rcv(skb) ? -1 : 0; 1064 } 1065 1066 static const struct inet6_protocol sctpv6_protocol = { 1067 .handler = sctp6_rcv, 1068 .err_handler = sctp_v6_err, 1069 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL, 1070 }; 1071 1072 static struct sctp_af sctp_af_inet6 = { 1073 .sa_family = AF_INET6, 1074 .sctp_xmit = sctp_v6_xmit, 1075 .setsockopt = ipv6_setsockopt, 1076 .getsockopt = ipv6_getsockopt, 1077 .get_dst = sctp_v6_get_dst, 1078 .get_saddr = sctp_v6_get_saddr, 1079 .copy_addrlist = sctp_v6_copy_addrlist, 1080 .from_skb = sctp_v6_from_skb, 1081 .from_sk = sctp_v6_from_sk, 1082 .from_addr_param = sctp_v6_from_addr_param, 1083 .to_addr_param = sctp_v6_to_addr_param, 1084 .cmp_addr = sctp_v6_cmp_addr, 1085 .scope = sctp_v6_scope, 1086 .addr_valid = sctp_v6_addr_valid, 1087 .inaddr_any = sctp_v6_inaddr_any, 1088 .is_any = sctp_v6_is_any, 1089 .available = sctp_v6_available, 1090 .skb_iif = sctp_v6_skb_iif, 1091 .is_ce = sctp_v6_is_ce, 1092 .seq_dump_addr = sctp_v6_seq_dump_addr, 1093 .ecn_capable = sctp_v6_ecn_capable, 1094 .net_header_len = sizeof(struct ipv6hdr), 1095 .sockaddr_len = sizeof(struct sockaddr_in6), 1096 .ip_options_len = sctp_v6_ip_options_len, 1097 #ifdef CONFIG_COMPAT 1098 .compat_setsockopt = compat_ipv6_setsockopt, 1099 .compat_getsockopt = compat_ipv6_getsockopt, 1100 #endif 1101 }; 1102 1103 static struct sctp_pf sctp_pf_inet6 = { 1104 .event_msgname = sctp_inet6_event_msgname, 1105 .skb_msgname = sctp_inet6_skb_msgname, 1106 .af_supported = sctp_inet6_af_supported, 1107 .cmp_addr = sctp_inet6_cmp_addr, 1108 .bind_verify = sctp_inet6_bind_verify, 1109 .send_verify = sctp_inet6_send_verify, 1110 .supported_addrs = sctp_inet6_supported_addrs, 1111 .create_accept_sk = sctp_v6_create_accept_sk, 1112 .addr_to_user = sctp_v6_addr_to_user, 1113 .to_sk_saddr = sctp_v6_to_sk_saddr, 1114 .to_sk_daddr = sctp_v6_to_sk_daddr, 1115 .copy_ip_options = sctp_v6_copy_ip_options, 1116 .af = &sctp_af_inet6, 1117 }; 1118 1119 /* Initialize IPv6 support and register with socket layer. */ 1120 void sctp_v6_pf_init(void) 1121 { 1122 /* Register the SCTP specific PF_INET6 functions. */ 1123 sctp_register_pf(&sctp_pf_inet6, PF_INET6); 1124 1125 /* Register the SCTP specific AF_INET6 functions. */ 1126 sctp_register_af(&sctp_af_inet6); 1127 } 1128 1129 void sctp_v6_pf_exit(void) 1130 { 1131 list_del(&sctp_af_inet6.list); 1132 } 1133 1134 /* Initialize IPv6 support and register with socket layer. */ 1135 int sctp_v6_protosw_init(void) 1136 { 1137 int rc; 1138 1139 rc = proto_register(&sctpv6_prot, 1); 1140 if (rc) 1141 return rc; 1142 1143 /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */ 1144 inet6_register_protosw(&sctpv6_seqpacket_protosw); 1145 inet6_register_protosw(&sctpv6_stream_protosw); 1146 1147 return 0; 1148 } 1149 1150 void sctp_v6_protosw_exit(void) 1151 { 1152 inet6_unregister_protosw(&sctpv6_seqpacket_protosw); 1153 inet6_unregister_protosw(&sctpv6_stream_protosw); 1154 proto_unregister(&sctpv6_prot); 1155 } 1156 1157 1158 /* Register with inet6 layer. */ 1159 int sctp_v6_add_protocol(void) 1160 { 1161 /* Register notifier for inet6 address additions/deletions. */ 1162 register_inet6addr_notifier(&sctp_inet6addr_notifier); 1163 1164 if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0) 1165 return -EAGAIN; 1166 1167 return 0; 1168 } 1169 1170 /* Unregister with inet6 layer. */ 1171 void sctp_v6_del_protocol(void) 1172 { 1173 inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP); 1174 unregister_inet6addr_notifier(&sctp_inet6addr_notifier); 1175 } 1176