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 <asm/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_BH(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, asoc); 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; 212 213 pr_debug("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n", __func__, skb, 214 skb->len, &fl6->saddr, &fl6->daddr); 215 216 IP6_ECN_flow_xmit(sk, fl6->flowlabel); 217 218 if (!(transport->param_flags & SPP_PMTUD_ENABLE)) 219 skb->ignore_df = 1; 220 221 SCTP_INC_STATS(sock_net(sk), SCTP_MIB_OUTSCTPPACKS); 222 223 return ip6_xmit(sk, skb, fl6, np->opt, np->tclass); 224 } 225 226 /* Returns the dst cache entry for the given source and destination ip 227 * addresses. 228 */ 229 static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr, 230 struct flowi *fl, struct sock *sk) 231 { 232 struct sctp_association *asoc = t->asoc; 233 struct dst_entry *dst = NULL; 234 struct flowi6 *fl6 = &fl->u.ip6; 235 struct sctp_bind_addr *bp; 236 struct ipv6_pinfo *np = inet6_sk(sk); 237 struct sctp_sockaddr_entry *laddr; 238 union sctp_addr *baddr = NULL; 239 union sctp_addr *daddr = &t->ipaddr; 240 union sctp_addr dst_saddr; 241 struct in6_addr *final_p, final; 242 __u8 matchlen = 0; 243 __u8 bmatchlen; 244 sctp_scope_t scope; 245 246 memset(fl6, 0, sizeof(struct flowi6)); 247 fl6->daddr = daddr->v6.sin6_addr; 248 fl6->fl6_dport = daddr->v6.sin6_port; 249 fl6->flowi6_proto = IPPROTO_SCTP; 250 if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) 251 fl6->flowi6_oif = daddr->v6.sin6_scope_id; 252 253 pr_debug("%s: dst=%pI6 ", __func__, &fl6->daddr); 254 255 if (asoc) 256 fl6->fl6_sport = htons(asoc->base.bind_addr.port); 257 258 if (saddr) { 259 fl6->saddr = saddr->v6.sin6_addr; 260 fl6->fl6_sport = saddr->v6.sin6_port; 261 262 pr_debug("src=%pI6 - ", &fl6->saddr); 263 } 264 265 final_p = fl6_update_dst(fl6, np->opt, &final); 266 dst = ip6_dst_lookup_flow(sk, fl6, final_p); 267 if (!asoc || saddr) 268 goto out; 269 270 bp = &asoc->base.bind_addr; 271 scope = sctp_scope(daddr); 272 /* ip6_dst_lookup has filled in the fl6->saddr for us. Check 273 * to see if we can use it. 274 */ 275 if (!IS_ERR(dst)) { 276 /* Walk through the bind address list and look for a bind 277 * address that matches the source address of the returned dst. 278 */ 279 sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port)); 280 rcu_read_lock(); 281 list_for_each_entry_rcu(laddr, &bp->address_list, list) { 282 if (!laddr->valid || laddr->state == SCTP_ADDR_DEL || 283 (laddr->state != SCTP_ADDR_SRC && 284 !asoc->src_out_of_asoc_ok)) 285 continue; 286 287 /* Do not compare against v4 addrs */ 288 if ((laddr->a.sa.sa_family == AF_INET6) && 289 (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) { 290 rcu_read_unlock(); 291 goto out; 292 } 293 } 294 rcu_read_unlock(); 295 /* None of the bound addresses match the source address of the 296 * dst. So release it. 297 */ 298 dst_release(dst); 299 dst = NULL; 300 } 301 302 /* Walk through the bind address list and try to get the 303 * best source address for a given destination. 304 */ 305 rcu_read_lock(); 306 list_for_each_entry_rcu(laddr, &bp->address_list, list) { 307 if (!laddr->valid) 308 continue; 309 if ((laddr->state == SCTP_ADDR_SRC) && 310 (laddr->a.sa.sa_family == AF_INET6) && 311 (scope <= sctp_scope(&laddr->a))) { 312 bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a); 313 if (!baddr || (matchlen < bmatchlen)) { 314 baddr = &laddr->a; 315 matchlen = bmatchlen; 316 } 317 } 318 } 319 rcu_read_unlock(); 320 321 if (baddr) { 322 fl6->saddr = baddr->v6.sin6_addr; 323 fl6->fl6_sport = baddr->v6.sin6_port; 324 final_p = fl6_update_dst(fl6, np->opt, &final); 325 dst = ip6_dst_lookup_flow(sk, fl6, final_p); 326 } 327 328 out: 329 if (!IS_ERR_OR_NULL(dst)) { 330 struct rt6_info *rt; 331 332 rt = (struct rt6_info *)dst; 333 t->dst = dst; 334 t->dst_cookie = rt6_get_cookie(rt); 335 pr_debug("rt6_dst:%pI6/%d rt6_src:%pI6\n", 336 &rt->rt6i_dst.addr, rt->rt6i_dst.plen, 337 &fl6->saddr); 338 } else { 339 t->dst = NULL; 340 341 pr_debug("no route\n"); 342 } 343 } 344 345 /* Returns the number of consecutive initial bits that match in the 2 ipv6 346 * addresses. 347 */ 348 static inline int sctp_v6_addr_match_len(union sctp_addr *s1, 349 union sctp_addr *s2) 350 { 351 return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr); 352 } 353 354 /* Fills in the source address(saddr) based on the destination address(daddr) 355 * and asoc's bind address list. 356 */ 357 static void sctp_v6_get_saddr(struct sctp_sock *sk, 358 struct sctp_transport *t, 359 struct flowi *fl) 360 { 361 struct flowi6 *fl6 = &fl->u.ip6; 362 union sctp_addr *saddr = &t->saddr; 363 364 pr_debug("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst); 365 366 if (t->dst) { 367 saddr->v6.sin6_family = AF_INET6; 368 saddr->v6.sin6_addr = fl6->saddr; 369 } 370 } 371 372 /* Make a copy of all potential local addresses. */ 373 static void sctp_v6_copy_addrlist(struct list_head *addrlist, 374 struct net_device *dev) 375 { 376 struct inet6_dev *in6_dev; 377 struct inet6_ifaddr *ifp; 378 struct sctp_sockaddr_entry *addr; 379 380 rcu_read_lock(); 381 if ((in6_dev = __in6_dev_get(dev)) == NULL) { 382 rcu_read_unlock(); 383 return; 384 } 385 386 read_lock_bh(&in6_dev->lock); 387 list_for_each_entry(ifp, &in6_dev->addr_list, if_list) { 388 /* Add the address to the local list. */ 389 addr = kzalloc(sizeof(*addr), GFP_ATOMIC); 390 if (addr) { 391 addr->a.v6.sin6_family = AF_INET6; 392 addr->a.v6.sin6_port = 0; 393 addr->a.v6.sin6_addr = ifp->addr; 394 addr->a.v6.sin6_scope_id = dev->ifindex; 395 addr->valid = 1; 396 INIT_LIST_HEAD(&addr->list); 397 list_add_tail(&addr->list, addrlist); 398 } 399 } 400 401 read_unlock_bh(&in6_dev->lock); 402 rcu_read_unlock(); 403 } 404 405 /* Initialize a sockaddr_storage from in incoming skb. */ 406 static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb, 407 int is_saddr) 408 { 409 __be16 *port; 410 struct sctphdr *sh; 411 412 port = &addr->v6.sin6_port; 413 addr->v6.sin6_family = AF_INET6; 414 addr->v6.sin6_flowinfo = 0; /* FIXME */ 415 addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif; 416 417 sh = sctp_hdr(skb); 418 if (is_saddr) { 419 *port = sh->source; 420 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr; 421 } else { 422 *port = sh->dest; 423 addr->v6.sin6_addr = ipv6_hdr(skb)->daddr; 424 } 425 } 426 427 /* Initialize an sctp_addr from a socket. */ 428 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk) 429 { 430 addr->v6.sin6_family = AF_INET6; 431 addr->v6.sin6_port = 0; 432 addr->v6.sin6_addr = sk->sk_v6_rcv_saddr; 433 } 434 435 /* Initialize sk->sk_rcv_saddr from sctp_addr. */ 436 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk) 437 { 438 if (addr->sa.sa_family == AF_INET) { 439 sk->sk_v6_rcv_saddr.s6_addr32[0] = 0; 440 sk->sk_v6_rcv_saddr.s6_addr32[1] = 0; 441 sk->sk_v6_rcv_saddr.s6_addr32[2] = htonl(0x0000ffff); 442 sk->sk_v6_rcv_saddr.s6_addr32[3] = 443 addr->v4.sin_addr.s_addr; 444 } else { 445 sk->sk_v6_rcv_saddr = addr->v6.sin6_addr; 446 } 447 } 448 449 /* Initialize sk->sk_daddr from sctp_addr. */ 450 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk) 451 { 452 if (addr->sa.sa_family == AF_INET) { 453 sk->sk_v6_daddr.s6_addr32[0] = 0; 454 sk->sk_v6_daddr.s6_addr32[1] = 0; 455 sk->sk_v6_daddr.s6_addr32[2] = htonl(0x0000ffff); 456 sk->sk_v6_daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr; 457 } else { 458 sk->sk_v6_daddr = addr->v6.sin6_addr; 459 } 460 } 461 462 /* Initialize a sctp_addr from an address parameter. */ 463 static void sctp_v6_from_addr_param(union sctp_addr *addr, 464 union sctp_addr_param *param, 465 __be16 port, int iif) 466 { 467 addr->v6.sin6_family = AF_INET6; 468 addr->v6.sin6_port = port; 469 addr->v6.sin6_flowinfo = 0; /* BUG */ 470 addr->v6.sin6_addr = param->v6.addr; 471 addr->v6.sin6_scope_id = iif; 472 } 473 474 /* Initialize an address parameter from a sctp_addr and return the length 475 * of the address parameter. 476 */ 477 static int sctp_v6_to_addr_param(const union sctp_addr *addr, 478 union sctp_addr_param *param) 479 { 480 int length = sizeof(sctp_ipv6addr_param_t); 481 482 param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS; 483 param->v6.param_hdr.length = htons(length); 484 param->v6.addr = addr->v6.sin6_addr; 485 486 return length; 487 } 488 489 /* Initialize a sctp_addr from struct in6_addr. */ 490 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr, 491 __be16 port) 492 { 493 addr->sa.sa_family = AF_INET6; 494 addr->v6.sin6_port = port; 495 addr->v6.sin6_addr = *saddr; 496 } 497 498 /* Compare addresses exactly. 499 * v4-mapped-v6 is also in consideration. 500 */ 501 static int sctp_v6_cmp_addr(const union sctp_addr *addr1, 502 const union sctp_addr *addr2) 503 { 504 if (addr1->sa.sa_family != addr2->sa.sa_family) { 505 if (addr1->sa.sa_family == AF_INET && 506 addr2->sa.sa_family == AF_INET6 && 507 ipv6_addr_v4mapped(&addr2->v6.sin6_addr)) { 508 if (addr2->v6.sin6_port == addr1->v4.sin_port && 509 addr2->v6.sin6_addr.s6_addr32[3] == 510 addr1->v4.sin_addr.s_addr) 511 return 1; 512 } 513 if (addr2->sa.sa_family == AF_INET && 514 addr1->sa.sa_family == AF_INET6 && 515 ipv6_addr_v4mapped(&addr1->v6.sin6_addr)) { 516 if (addr1->v6.sin6_port == addr2->v4.sin_port && 517 addr1->v6.sin6_addr.s6_addr32[3] == 518 addr2->v4.sin_addr.s_addr) 519 return 1; 520 } 521 return 0; 522 } 523 if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr)) 524 return 0; 525 /* If this is a linklocal address, compare the scope_id. */ 526 if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) { 527 if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id && 528 (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) { 529 return 0; 530 } 531 } 532 533 return 1; 534 } 535 536 /* Initialize addr struct to INADDR_ANY. */ 537 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port) 538 { 539 memset(addr, 0x00, sizeof(union sctp_addr)); 540 addr->v6.sin6_family = AF_INET6; 541 addr->v6.sin6_port = port; 542 } 543 544 /* Is this a wildcard address? */ 545 static int sctp_v6_is_any(const union sctp_addr *addr) 546 { 547 return ipv6_addr_any(&addr->v6.sin6_addr); 548 } 549 550 /* Should this be available for binding? */ 551 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp) 552 { 553 int type; 554 const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr; 555 556 type = ipv6_addr_type(in6); 557 if (IPV6_ADDR_ANY == type) 558 return 1; 559 if (type == IPV6_ADDR_MAPPED) { 560 if (sp && ipv6_only_sock(sctp_opt2sk(sp))) 561 return 0; 562 sctp_v6_map_v4(addr); 563 return sctp_get_af_specific(AF_INET)->available(addr, sp); 564 } 565 if (!(type & IPV6_ADDR_UNICAST)) 566 return 0; 567 568 return ipv6_chk_addr(sock_net(&sp->inet.sk), in6, NULL, 0); 569 } 570 571 /* This function checks if the address is a valid address to be used for 572 * SCTP. 573 * 574 * Output: 575 * Return 0 - If the address is a non-unicast or an illegal address. 576 * Return 1 - If the address is a unicast. 577 */ 578 static int sctp_v6_addr_valid(union sctp_addr *addr, 579 struct sctp_sock *sp, 580 const struct sk_buff *skb) 581 { 582 int ret = ipv6_addr_type(&addr->v6.sin6_addr); 583 584 /* Support v4-mapped-v6 address. */ 585 if (ret == IPV6_ADDR_MAPPED) { 586 /* Note: This routine is used in input, so v4-mapped-v6 587 * are disallowed here when there is no sctp_sock. 588 */ 589 if (sp && ipv6_only_sock(sctp_opt2sk(sp))) 590 return 0; 591 sctp_v6_map_v4(addr); 592 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb); 593 } 594 595 /* Is this a non-unicast address */ 596 if (!(ret & IPV6_ADDR_UNICAST)) 597 return 0; 598 599 return 1; 600 } 601 602 /* What is the scope of 'addr'? */ 603 static sctp_scope_t sctp_v6_scope(union sctp_addr *addr) 604 { 605 int v6scope; 606 sctp_scope_t retval; 607 608 /* The IPv6 scope is really a set of bit fields. 609 * See IFA_* in <net/if_inet6.h>. Map to a generic SCTP scope. 610 */ 611 612 v6scope = ipv6_addr_scope(&addr->v6.sin6_addr); 613 switch (v6scope) { 614 case IFA_HOST: 615 retval = SCTP_SCOPE_LOOPBACK; 616 break; 617 case IFA_LINK: 618 retval = SCTP_SCOPE_LINK; 619 break; 620 case IFA_SITE: 621 retval = SCTP_SCOPE_PRIVATE; 622 break; 623 default: 624 retval = SCTP_SCOPE_GLOBAL; 625 break; 626 } 627 628 return retval; 629 } 630 631 /* Create and initialize a new sk for the socket to be returned by accept(). */ 632 static struct sock *sctp_v6_create_accept_sk(struct sock *sk, 633 struct sctp_association *asoc) 634 { 635 struct sock *newsk; 636 struct ipv6_pinfo *newnp, *np = inet6_sk(sk); 637 struct sctp6_sock *newsctp6sk; 638 639 newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot, 0); 640 if (!newsk) 641 goto out; 642 643 sock_init_data(NULL, newsk); 644 645 sctp_copy_sock(newsk, sk, asoc); 646 sock_reset_flag(sk, SOCK_ZAPPED); 647 648 newsctp6sk = (struct sctp6_sock *)newsk; 649 inet_sk(newsk)->pinet6 = &newsctp6sk->inet6; 650 651 sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped; 652 653 newnp = inet6_sk(newsk); 654 655 memcpy(newnp, np, sizeof(struct ipv6_pinfo)); 656 657 /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname() 658 * and getpeername(). 659 */ 660 sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk); 661 662 newsk->sk_v6_rcv_saddr = sk->sk_v6_rcv_saddr; 663 664 sk_refcnt_debug_inc(newsk); 665 666 if (newsk->sk_prot->init(newsk)) { 667 sk_common_release(newsk); 668 newsk = NULL; 669 } 670 671 out: 672 return newsk; 673 } 674 675 /* Format a sockaddr for return to user space. This makes sure the return is 676 * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option. 677 */ 678 static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr) 679 { 680 if (sp->v4mapped) { 681 if (addr->sa.sa_family == AF_INET) 682 sctp_v4_map_v6(addr); 683 } else { 684 if (addr->sa.sa_family == AF_INET6 && 685 ipv6_addr_v4mapped(&addr->v6.sin6_addr)) 686 sctp_v6_map_v4(addr); 687 } 688 689 if (addr->sa.sa_family == AF_INET) 690 return sizeof(struct sockaddr_in); 691 return sizeof(struct sockaddr_in6); 692 } 693 694 /* Where did this skb come from? */ 695 static int sctp_v6_skb_iif(const struct sk_buff *skb) 696 { 697 struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb; 698 return opt->iif; 699 } 700 701 /* Was this packet marked by Explicit Congestion Notification? */ 702 static int sctp_v6_is_ce(const struct sk_buff *skb) 703 { 704 return *((__u32 *)(ipv6_hdr(skb))) & htonl(1 << 20); 705 } 706 707 /* Dump the v6 addr to the seq file. */ 708 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr) 709 { 710 seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr); 711 } 712 713 static void sctp_v6_ecn_capable(struct sock *sk) 714 { 715 inet6_sk(sk)->tclass |= INET_ECN_ECT_0; 716 } 717 718 /* Initialize a PF_INET msgname from a ulpevent. */ 719 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event, 720 char *msgname, int *addrlen) 721 { 722 union sctp_addr *addr; 723 struct sctp_association *asoc; 724 union sctp_addr *paddr; 725 726 if (!msgname) 727 return; 728 729 addr = (union sctp_addr *)msgname; 730 asoc = event->asoc; 731 paddr = &asoc->peer.primary_addr; 732 733 if (paddr->sa.sa_family == AF_INET) { 734 addr->v4.sin_family = AF_INET; 735 addr->v4.sin_port = htons(asoc->peer.port); 736 addr->v4.sin_addr = paddr->v4.sin_addr; 737 } else { 738 addr->v6.sin6_family = AF_INET6; 739 addr->v6.sin6_flowinfo = 0; 740 if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) 741 addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id; 742 else 743 addr->v6.sin6_scope_id = 0; 744 addr->v6.sin6_port = htons(asoc->peer.port); 745 addr->v6.sin6_addr = paddr->v6.sin6_addr; 746 } 747 748 *addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr); 749 } 750 751 /* Initialize a msg_name from an inbound skb. */ 752 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname, 753 int *addr_len) 754 { 755 union sctp_addr *addr; 756 struct sctphdr *sh; 757 758 if (!msgname) 759 return; 760 761 addr = (union sctp_addr *)msgname; 762 sh = sctp_hdr(skb); 763 764 if (ip_hdr(skb)->version == 4) { 765 addr->v4.sin_family = AF_INET; 766 addr->v4.sin_port = sh->source; 767 addr->v4.sin_addr.s_addr = ip_hdr(skb)->saddr; 768 } else { 769 addr->v6.sin6_family = AF_INET6; 770 addr->v6.sin6_flowinfo = 0; 771 addr->v6.sin6_port = sh->source; 772 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr; 773 if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) { 774 struct sctp_ulpevent *ev = sctp_skb2event(skb); 775 addr->v6.sin6_scope_id = ev->iif; 776 } 777 } 778 779 *addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr); 780 } 781 782 /* Do we support this AF? */ 783 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp) 784 { 785 switch (family) { 786 case AF_INET6: 787 return 1; 788 /* v4-mapped-v6 addresses */ 789 case AF_INET: 790 if (!__ipv6_only_sock(sctp_opt2sk(sp))) 791 return 1; 792 default: 793 return 0; 794 } 795 } 796 797 /* Address matching with wildcards allowed. This extra level 798 * of indirection lets us choose whether a PF_INET6 should 799 * disallow any v4 addresses if we so choose. 800 */ 801 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1, 802 const union sctp_addr *addr2, 803 struct sctp_sock *opt) 804 { 805 struct sctp_af *af1, *af2; 806 struct sock *sk = sctp_opt2sk(opt); 807 808 af1 = sctp_get_af_specific(addr1->sa.sa_family); 809 af2 = sctp_get_af_specific(addr2->sa.sa_family); 810 811 if (!af1 || !af2) 812 return 0; 813 814 /* If the socket is IPv6 only, v4 addrs will not match */ 815 if (__ipv6_only_sock(sk) && af1 != af2) 816 return 0; 817 818 /* Today, wildcard AF_INET/AF_INET6. */ 819 if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2)) 820 return 1; 821 822 if (addr1->sa.sa_family != addr2->sa.sa_family) 823 return 0; 824 825 return af1->cmp_addr(addr1, addr2); 826 } 827 828 /* Verify that the provided sockaddr looks bindable. Common verification, 829 * has already been taken care of. 830 */ 831 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr) 832 { 833 struct sctp_af *af; 834 835 /* ASSERT: address family has already been verified. */ 836 if (addr->sa.sa_family != AF_INET6) 837 af = sctp_get_af_specific(addr->sa.sa_family); 838 else { 839 int type = ipv6_addr_type(&addr->v6.sin6_addr); 840 struct net_device *dev; 841 842 if (type & IPV6_ADDR_LINKLOCAL) { 843 struct net *net; 844 if (!addr->v6.sin6_scope_id) 845 return 0; 846 net = sock_net(&opt->inet.sk); 847 rcu_read_lock(); 848 dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id); 849 if (!dev || 850 !ipv6_chk_addr(net, &addr->v6.sin6_addr, dev, 0)) { 851 rcu_read_unlock(); 852 return 0; 853 } 854 rcu_read_unlock(); 855 } 856 857 af = opt->pf->af; 858 } 859 return af->available(addr, opt); 860 } 861 862 /* Verify that the provided sockaddr looks sendable. Common verification, 863 * has already been taken care of. 864 */ 865 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr) 866 { 867 struct sctp_af *af = NULL; 868 869 /* ASSERT: address family has already been verified. */ 870 if (addr->sa.sa_family != AF_INET6) 871 af = sctp_get_af_specific(addr->sa.sa_family); 872 else { 873 int type = ipv6_addr_type(&addr->v6.sin6_addr); 874 struct net_device *dev; 875 876 if (type & IPV6_ADDR_LINKLOCAL) { 877 if (!addr->v6.sin6_scope_id) 878 return 0; 879 rcu_read_lock(); 880 dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk), 881 addr->v6.sin6_scope_id); 882 rcu_read_unlock(); 883 if (!dev) 884 return 0; 885 } 886 af = opt->pf->af; 887 } 888 889 return af != NULL; 890 } 891 892 /* Fill in Supported Address Type information for INIT and INIT-ACK 893 * chunks. Note: In the future, we may want to look at sock options 894 * to determine whether a PF_INET6 socket really wants to have IPV4 895 * addresses. 896 * Returns number of addresses supported. 897 */ 898 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt, 899 __be16 *types) 900 { 901 types[0] = SCTP_PARAM_IPV6_ADDRESS; 902 if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) { 903 types[1] = SCTP_PARAM_IPV4_ADDRESS; 904 return 2; 905 } 906 return 1; 907 } 908 909 /* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */ 910 static int sctp_getname(struct socket *sock, struct sockaddr *uaddr, 911 int *uaddr_len, int peer) 912 { 913 int rc; 914 915 rc = inet6_getname(sock, uaddr, uaddr_len, peer); 916 917 if (rc != 0) 918 return rc; 919 920 *uaddr_len = sctp_v6_addr_to_user(sctp_sk(sock->sk), 921 (union sctp_addr *)uaddr); 922 923 return rc; 924 } 925 926 static const struct proto_ops inet6_seqpacket_ops = { 927 .family = PF_INET6, 928 .owner = THIS_MODULE, 929 .release = inet6_release, 930 .bind = inet6_bind, 931 .connect = inet_dgram_connect, 932 .socketpair = sock_no_socketpair, 933 .accept = inet_accept, 934 .getname = sctp_getname, 935 .poll = sctp_poll, 936 .ioctl = inet6_ioctl, 937 .listen = sctp_inet_listen, 938 .shutdown = inet_shutdown, 939 .setsockopt = sock_common_setsockopt, 940 .getsockopt = sock_common_getsockopt, 941 .sendmsg = inet_sendmsg, 942 .recvmsg = sock_common_recvmsg, 943 .mmap = sock_no_mmap, 944 #ifdef CONFIG_COMPAT 945 .compat_setsockopt = compat_sock_common_setsockopt, 946 .compat_getsockopt = compat_sock_common_getsockopt, 947 #endif 948 }; 949 950 static struct inet_protosw sctpv6_seqpacket_protosw = { 951 .type = SOCK_SEQPACKET, 952 .protocol = IPPROTO_SCTP, 953 .prot = &sctpv6_prot, 954 .ops = &inet6_seqpacket_ops, 955 .flags = SCTP_PROTOSW_FLAG 956 }; 957 static struct inet_protosw sctpv6_stream_protosw = { 958 .type = SOCK_STREAM, 959 .protocol = IPPROTO_SCTP, 960 .prot = &sctpv6_prot, 961 .ops = &inet6_seqpacket_ops, 962 .flags = SCTP_PROTOSW_FLAG, 963 }; 964 965 static int sctp6_rcv(struct sk_buff *skb) 966 { 967 return sctp_rcv(skb) ? -1 : 0; 968 } 969 970 static const struct inet6_protocol sctpv6_protocol = { 971 .handler = sctp6_rcv, 972 .err_handler = sctp_v6_err, 973 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL, 974 }; 975 976 static struct sctp_af sctp_af_inet6 = { 977 .sa_family = AF_INET6, 978 .sctp_xmit = sctp_v6_xmit, 979 .setsockopt = ipv6_setsockopt, 980 .getsockopt = ipv6_getsockopt, 981 .get_dst = sctp_v6_get_dst, 982 .get_saddr = sctp_v6_get_saddr, 983 .copy_addrlist = sctp_v6_copy_addrlist, 984 .from_skb = sctp_v6_from_skb, 985 .from_sk = sctp_v6_from_sk, 986 .from_addr_param = sctp_v6_from_addr_param, 987 .to_addr_param = sctp_v6_to_addr_param, 988 .cmp_addr = sctp_v6_cmp_addr, 989 .scope = sctp_v6_scope, 990 .addr_valid = sctp_v6_addr_valid, 991 .inaddr_any = sctp_v6_inaddr_any, 992 .is_any = sctp_v6_is_any, 993 .available = sctp_v6_available, 994 .skb_iif = sctp_v6_skb_iif, 995 .is_ce = sctp_v6_is_ce, 996 .seq_dump_addr = sctp_v6_seq_dump_addr, 997 .ecn_capable = sctp_v6_ecn_capable, 998 .net_header_len = sizeof(struct ipv6hdr), 999 .sockaddr_len = sizeof(struct sockaddr_in6), 1000 #ifdef CONFIG_COMPAT 1001 .compat_setsockopt = compat_ipv6_setsockopt, 1002 .compat_getsockopt = compat_ipv6_getsockopt, 1003 #endif 1004 }; 1005 1006 static struct sctp_pf sctp_pf_inet6 = { 1007 .event_msgname = sctp_inet6_event_msgname, 1008 .skb_msgname = sctp_inet6_skb_msgname, 1009 .af_supported = sctp_inet6_af_supported, 1010 .cmp_addr = sctp_inet6_cmp_addr, 1011 .bind_verify = sctp_inet6_bind_verify, 1012 .send_verify = sctp_inet6_send_verify, 1013 .supported_addrs = sctp_inet6_supported_addrs, 1014 .create_accept_sk = sctp_v6_create_accept_sk, 1015 .addr_to_user = sctp_v6_addr_to_user, 1016 .to_sk_saddr = sctp_v6_to_sk_saddr, 1017 .to_sk_daddr = sctp_v6_to_sk_daddr, 1018 .af = &sctp_af_inet6, 1019 }; 1020 1021 /* Initialize IPv6 support and register with socket layer. */ 1022 void sctp_v6_pf_init(void) 1023 { 1024 /* Register the SCTP specific PF_INET6 functions. */ 1025 sctp_register_pf(&sctp_pf_inet6, PF_INET6); 1026 1027 /* Register the SCTP specific AF_INET6 functions. */ 1028 sctp_register_af(&sctp_af_inet6); 1029 } 1030 1031 void sctp_v6_pf_exit(void) 1032 { 1033 list_del(&sctp_af_inet6.list); 1034 } 1035 1036 /* Initialize IPv6 support and register with socket layer. */ 1037 int sctp_v6_protosw_init(void) 1038 { 1039 int rc; 1040 1041 rc = proto_register(&sctpv6_prot, 1); 1042 if (rc) 1043 return rc; 1044 1045 /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */ 1046 inet6_register_protosw(&sctpv6_seqpacket_protosw); 1047 inet6_register_protosw(&sctpv6_stream_protosw); 1048 1049 return 0; 1050 } 1051 1052 void sctp_v6_protosw_exit(void) 1053 { 1054 inet6_unregister_protosw(&sctpv6_seqpacket_protosw); 1055 inet6_unregister_protosw(&sctpv6_stream_protosw); 1056 proto_unregister(&sctpv6_prot); 1057 } 1058 1059 1060 /* Register with inet6 layer. */ 1061 int sctp_v6_add_protocol(void) 1062 { 1063 /* Register notifier for inet6 address additions/deletions. */ 1064 register_inet6addr_notifier(&sctp_inet6addr_notifier); 1065 1066 if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0) 1067 return -EAGAIN; 1068 1069 return 0; 1070 } 1071 1072 /* Unregister with inet6 layer. */ 1073 void sctp_v6_del_protocol(void) 1074 { 1075 inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP); 1076 unregister_inet6addr_notifier(&sctp_inet6addr_notifier); 1077 } 1078