1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* SCTP kernel implementation 3 * (C) Copyright IBM Corp. 2002, 2004 4 * Copyright (c) 2001 Nokia, Inc. 5 * Copyright (c) 2001 La Monte H.P. Yarroll 6 * Copyright (c) 2002-2003 Intel Corp. 7 * 8 * This file is part of the SCTP kernel implementation 9 * 10 * SCTP over IPv6. 11 * 12 * Please send any bug reports or fixes you make to the 13 * email address(es): 14 * lksctp developers <linux-sctp@vger.kernel.org> 15 * 16 * Written or modified by: 17 * Le Yanqun <yanqun.le@nokia.com> 18 * Hui Huang <hui.huang@nokia.com> 19 * La Monte H.P. Yarroll <piggy@acm.org> 20 * Sridhar Samudrala <sri@us.ibm.com> 21 * Jon Grimm <jgrimm@us.ibm.com> 22 * Ardelle Fan <ardelle.fan@intel.com> 23 * 24 * Based on: 25 * linux/net/ipv6/tcp_ipv6.c 26 */ 27 28 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 29 30 #include <linux/module.h> 31 #include <linux/errno.h> 32 #include <linux/types.h> 33 #include <linux/socket.h> 34 #include <linux/sockios.h> 35 #include <linux/net.h> 36 #include <linux/in.h> 37 #include <linux/in6.h> 38 #include <linux/netdevice.h> 39 #include <linux/init.h> 40 #include <linux/ipsec.h> 41 #include <linux/slab.h> 42 43 #include <linux/ipv6.h> 44 #include <linux/icmpv6.h> 45 #include <linux/random.h> 46 #include <linux/seq_file.h> 47 48 #include <net/protocol.h> 49 #include <net/ndisc.h> 50 #include <net/ip.h> 51 #include <net/ipv6.h> 52 #include <net/transp_v6.h> 53 #include <net/addrconf.h> 54 #include <net/ip6_route.h> 55 #include <net/inet_common.h> 56 #include <net/inet_ecn.h> 57 #include <net/sctp/sctp.h> 58 #include <net/udp_tunnel.h> 59 60 #include <linux/uaccess.h> 61 62 static inline int sctp_v6_addr_match_len(union sctp_addr *s1, 63 union sctp_addr *s2); 64 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr, 65 __be16 port); 66 static int sctp_v6_cmp_addr(const union sctp_addr *addr1, 67 const union sctp_addr *addr2); 68 69 /* Event handler for inet6 address addition/deletion events. 70 * The sctp_local_addr_list needs to be protocted by a spin lock since 71 * multiple notifiers (say IPv4 and IPv6) may be running at the same 72 * time and thus corrupt the list. 73 * The reader side is protected with RCU. 74 */ 75 static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev, 76 void *ptr) 77 { 78 struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr; 79 struct sctp_sockaddr_entry *addr = NULL; 80 struct sctp_sockaddr_entry *temp; 81 struct net *net = dev_net(ifa->idev->dev); 82 int found = 0; 83 84 switch (ev) { 85 case NETDEV_UP: 86 addr = kzalloc(sizeof(*addr), GFP_ATOMIC); 87 if (addr) { 88 addr->a.v6.sin6_family = AF_INET6; 89 addr->a.v6.sin6_addr = ifa->addr; 90 addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex; 91 addr->valid = 1; 92 spin_lock_bh(&net->sctp.local_addr_lock); 93 list_add_tail_rcu(&addr->list, &net->sctp.local_addr_list); 94 sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_NEW); 95 spin_unlock_bh(&net->sctp.local_addr_lock); 96 } 97 break; 98 case NETDEV_DOWN: 99 spin_lock_bh(&net->sctp.local_addr_lock); 100 list_for_each_entry_safe(addr, temp, 101 &net->sctp.local_addr_list, list) { 102 if (addr->a.sa.sa_family == AF_INET6 && 103 ipv6_addr_equal(&addr->a.v6.sin6_addr, 104 &ifa->addr)) { 105 sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL); 106 found = 1; 107 addr->valid = 0; 108 list_del_rcu(&addr->list); 109 break; 110 } 111 } 112 spin_unlock_bh(&net->sctp.local_addr_lock); 113 if (found) 114 kfree_rcu(addr, rcu); 115 break; 116 } 117 118 return NOTIFY_DONE; 119 } 120 121 static struct notifier_block sctp_inet6addr_notifier = { 122 .notifier_call = sctp_inet6addr_event, 123 }; 124 125 static void sctp_v6_err_handle(struct sctp_transport *t, struct sk_buff *skb, 126 __u8 type, __u8 code, __u32 info) 127 { 128 struct sctp_association *asoc = t->asoc; 129 struct sock *sk = asoc->base.sk; 130 struct ipv6_pinfo *np; 131 int err = 0; 132 133 switch (type) { 134 case ICMPV6_PKT_TOOBIG: 135 if (ip6_sk_accept_pmtu(sk)) 136 sctp_icmp_frag_needed(sk, asoc, t, info); 137 return; 138 case ICMPV6_PARAMPROB: 139 if (ICMPV6_UNK_NEXTHDR == code) { 140 sctp_icmp_proto_unreachable(sk, asoc, t); 141 return; 142 } 143 break; 144 case NDISC_REDIRECT: 145 sctp_icmp_redirect(sk, t, skb); 146 return; 147 default: 148 break; 149 } 150 151 np = inet6_sk(sk); 152 icmpv6_err_convert(type, code, &err); 153 if (!sock_owned_by_user(sk) && np->recverr) { 154 sk->sk_err = err; 155 sk->sk_error_report(sk); 156 } else { 157 sk->sk_err_soft = err; 158 } 159 } 160 161 /* ICMP error handler. */ 162 static int sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 163 u8 type, u8 code, int offset, __be32 info) 164 { 165 struct net *net = dev_net(skb->dev); 166 struct sctp_transport *transport; 167 struct sctp_association *asoc; 168 __u16 saveip, savesctp; 169 struct sock *sk; 170 171 /* Fix up skb to look at the embedded net header. */ 172 saveip = skb->network_header; 173 savesctp = skb->transport_header; 174 skb_reset_network_header(skb); 175 skb_set_transport_header(skb, offset); 176 sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &transport); 177 /* Put back, the original pointers. */ 178 skb->network_header = saveip; 179 skb->transport_header = savesctp; 180 if (!sk) { 181 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS); 182 return -ENOENT; 183 } 184 185 sctp_v6_err_handle(transport, skb, type, code, ntohl(info)); 186 sctp_err_finish(sk, transport); 187 188 return 0; 189 } 190 191 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *t) 192 { 193 struct dst_entry *dst = dst_clone(t->dst); 194 struct flowi6 *fl6 = &t->fl.u.ip6; 195 struct sock *sk = skb->sk; 196 struct ipv6_pinfo *np = inet6_sk(sk); 197 __u8 tclass = np->tclass; 198 __be32 label; 199 200 pr_debug("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n", __func__, skb, 201 skb->len, &fl6->saddr, &fl6->daddr); 202 203 if (t->dscp & SCTP_DSCP_SET_MASK) 204 tclass = t->dscp & SCTP_DSCP_VAL_MASK; 205 206 if (INET_ECN_is_capable(tclass)) 207 IP6_ECN_flow_xmit(sk, fl6->flowlabel); 208 209 if (!(t->param_flags & SPP_PMTUD_ENABLE)) 210 skb->ignore_df = 1; 211 212 SCTP_INC_STATS(sock_net(sk), SCTP_MIB_OUTSCTPPACKS); 213 214 if (!t->encap_port || !sctp_sk(sk)->udp_port) { 215 int res; 216 217 skb_dst_set(skb, dst); 218 rcu_read_lock(); 219 res = ip6_xmit(sk, skb, fl6, sk->sk_mark, 220 rcu_dereference(np->opt), 221 tclass, sk->sk_priority); 222 rcu_read_unlock(); 223 return res; 224 } 225 226 if (skb_is_gso(skb)) 227 skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL_CSUM; 228 229 skb->encapsulation = 1; 230 skb_reset_inner_mac_header(skb); 231 skb_reset_inner_transport_header(skb); 232 skb_set_inner_ipproto(skb, IPPROTO_SCTP); 233 label = ip6_make_flowlabel(sock_net(sk), skb, fl6->flowlabel, true, fl6); 234 235 return udp_tunnel6_xmit_skb(dst, sk, skb, NULL, &fl6->saddr, 236 &fl6->daddr, tclass, ip6_dst_hoplimit(dst), 237 label, sctp_sk(sk)->udp_port, t->encap_port, false); 238 } 239 240 /* Returns the dst cache entry for the given source and destination ip 241 * addresses. 242 */ 243 static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr, 244 struct flowi *fl, struct sock *sk) 245 { 246 struct sctp_association *asoc = t->asoc; 247 struct dst_entry *dst = NULL; 248 struct flowi _fl; 249 struct flowi6 *fl6 = &_fl.u.ip6; 250 struct sctp_bind_addr *bp; 251 struct ipv6_pinfo *np = inet6_sk(sk); 252 struct sctp_sockaddr_entry *laddr; 253 union sctp_addr *daddr = &t->ipaddr; 254 union sctp_addr dst_saddr; 255 struct in6_addr *final_p, final; 256 enum sctp_scope scope; 257 __u8 matchlen = 0; 258 259 memset(&_fl, 0, sizeof(_fl)); 260 fl6->daddr = daddr->v6.sin6_addr; 261 fl6->fl6_dport = daddr->v6.sin6_port; 262 fl6->flowi6_proto = IPPROTO_SCTP; 263 if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) 264 fl6->flowi6_oif = daddr->v6.sin6_scope_id; 265 else if (asoc) 266 fl6->flowi6_oif = asoc->base.sk->sk_bound_dev_if; 267 if (t->flowlabel & SCTP_FLOWLABEL_SET_MASK) 268 fl6->flowlabel = htonl(t->flowlabel & SCTP_FLOWLABEL_VAL_MASK); 269 270 if (np->sndflow && (fl6->flowlabel & IPV6_FLOWLABEL_MASK)) { 271 struct ip6_flowlabel *flowlabel; 272 273 flowlabel = fl6_sock_lookup(sk, fl6->flowlabel); 274 if (IS_ERR(flowlabel)) 275 goto out; 276 fl6_sock_release(flowlabel); 277 } 278 279 pr_debug("%s: dst=%pI6 ", __func__, &fl6->daddr); 280 281 if (asoc) 282 fl6->fl6_sport = htons(asoc->base.bind_addr.port); 283 284 if (saddr) { 285 fl6->saddr = saddr->v6.sin6_addr; 286 if (!fl6->fl6_sport) 287 fl6->fl6_sport = saddr->v6.sin6_port; 288 289 pr_debug("src=%pI6 - ", &fl6->saddr); 290 } 291 292 rcu_read_lock(); 293 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final); 294 rcu_read_unlock(); 295 296 dst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p); 297 if (!asoc || saddr) { 298 t->dst = dst; 299 memcpy(fl, &_fl, sizeof(_fl)); 300 goto out; 301 } 302 303 bp = &asoc->base.bind_addr; 304 scope = sctp_scope(daddr); 305 /* ip6_dst_lookup has filled in the fl6->saddr for us. Check 306 * to see if we can use it. 307 */ 308 if (!IS_ERR(dst)) { 309 /* Walk through the bind address list and look for a bind 310 * address that matches the source address of the returned dst. 311 */ 312 sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port)); 313 rcu_read_lock(); 314 list_for_each_entry_rcu(laddr, &bp->address_list, list) { 315 if (!laddr->valid || laddr->state == SCTP_ADDR_DEL || 316 (laddr->state != SCTP_ADDR_SRC && 317 !asoc->src_out_of_asoc_ok)) 318 continue; 319 320 /* Do not compare against v4 addrs */ 321 if ((laddr->a.sa.sa_family == AF_INET6) && 322 (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) { 323 rcu_read_unlock(); 324 t->dst = dst; 325 memcpy(fl, &_fl, sizeof(_fl)); 326 goto out; 327 } 328 } 329 rcu_read_unlock(); 330 /* None of the bound addresses match the source address of the 331 * dst. So release it. 332 */ 333 dst_release(dst); 334 dst = NULL; 335 } 336 337 /* Walk through the bind address list and try to get the 338 * best source address for a given destination. 339 */ 340 rcu_read_lock(); 341 list_for_each_entry_rcu(laddr, &bp->address_list, list) { 342 struct dst_entry *bdst; 343 __u8 bmatchlen; 344 345 if (!laddr->valid || 346 laddr->state != SCTP_ADDR_SRC || 347 laddr->a.sa.sa_family != AF_INET6 || 348 scope > sctp_scope(&laddr->a)) 349 continue; 350 351 fl6->saddr = laddr->a.v6.sin6_addr; 352 fl6->fl6_sport = laddr->a.v6.sin6_port; 353 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final); 354 bdst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p); 355 356 if (IS_ERR(bdst)) 357 continue; 358 359 if (ipv6_chk_addr(dev_net(bdst->dev), 360 &laddr->a.v6.sin6_addr, bdst->dev, 1)) { 361 if (!IS_ERR_OR_NULL(dst)) 362 dst_release(dst); 363 dst = bdst; 364 t->dst = dst; 365 memcpy(fl, &_fl, sizeof(_fl)); 366 break; 367 } 368 369 bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a); 370 if (matchlen > bmatchlen) { 371 dst_release(bdst); 372 continue; 373 } 374 375 if (!IS_ERR_OR_NULL(dst)) 376 dst_release(dst); 377 dst = bdst; 378 matchlen = bmatchlen; 379 t->dst = dst; 380 memcpy(fl, &_fl, sizeof(_fl)); 381 } 382 rcu_read_unlock(); 383 384 out: 385 if (!IS_ERR_OR_NULL(dst)) { 386 struct rt6_info *rt; 387 388 rt = (struct rt6_info *)dst; 389 t->dst_cookie = rt6_get_cookie(rt); 390 pr_debug("rt6_dst:%pI6/%d rt6_src:%pI6\n", 391 &rt->rt6i_dst.addr, rt->rt6i_dst.plen, 392 &fl->u.ip6.saddr); 393 } else { 394 t->dst = NULL; 395 pr_debug("no route\n"); 396 } 397 } 398 399 /* Returns the number of consecutive initial bits that match in the 2 ipv6 400 * addresses. 401 */ 402 static inline int sctp_v6_addr_match_len(union sctp_addr *s1, 403 union sctp_addr *s2) 404 { 405 return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr); 406 } 407 408 /* Fills in the source address(saddr) based on the destination address(daddr) 409 * and asoc's bind address list. 410 */ 411 static void sctp_v6_get_saddr(struct sctp_sock *sk, 412 struct sctp_transport *t, 413 struct flowi *fl) 414 { 415 struct flowi6 *fl6 = &fl->u.ip6; 416 union sctp_addr *saddr = &t->saddr; 417 418 pr_debug("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst); 419 420 if (t->dst) { 421 saddr->v6.sin6_family = AF_INET6; 422 saddr->v6.sin6_addr = fl6->saddr; 423 } 424 } 425 426 /* Make a copy of all potential local addresses. */ 427 static void sctp_v6_copy_addrlist(struct list_head *addrlist, 428 struct net_device *dev) 429 { 430 struct inet6_dev *in6_dev; 431 struct inet6_ifaddr *ifp; 432 struct sctp_sockaddr_entry *addr; 433 434 rcu_read_lock(); 435 if ((in6_dev = __in6_dev_get(dev)) == NULL) { 436 rcu_read_unlock(); 437 return; 438 } 439 440 read_lock_bh(&in6_dev->lock); 441 list_for_each_entry(ifp, &in6_dev->addr_list, if_list) { 442 /* Add the address to the local list. */ 443 addr = kzalloc(sizeof(*addr), GFP_ATOMIC); 444 if (addr) { 445 addr->a.v6.sin6_family = AF_INET6; 446 addr->a.v6.sin6_addr = ifp->addr; 447 addr->a.v6.sin6_scope_id = dev->ifindex; 448 addr->valid = 1; 449 INIT_LIST_HEAD(&addr->list); 450 list_add_tail(&addr->list, addrlist); 451 } 452 } 453 454 read_unlock_bh(&in6_dev->lock); 455 rcu_read_unlock(); 456 } 457 458 /* Copy over any ip options */ 459 static void sctp_v6_copy_ip_options(struct sock *sk, struct sock *newsk) 460 { 461 struct ipv6_pinfo *newnp, *np = inet6_sk(sk); 462 struct ipv6_txoptions *opt; 463 464 newnp = inet6_sk(newsk); 465 466 rcu_read_lock(); 467 opt = rcu_dereference(np->opt); 468 if (opt) { 469 opt = ipv6_dup_options(newsk, opt); 470 if (!opt) 471 pr_err("%s: Failed to copy ip options\n", __func__); 472 } 473 RCU_INIT_POINTER(newnp->opt, opt); 474 rcu_read_unlock(); 475 } 476 477 /* Account for the IP options */ 478 static int sctp_v6_ip_options_len(struct sock *sk) 479 { 480 struct ipv6_pinfo *np = inet6_sk(sk); 481 struct ipv6_txoptions *opt; 482 int len = 0; 483 484 rcu_read_lock(); 485 opt = rcu_dereference(np->opt); 486 if (opt) 487 len = opt->opt_flen + opt->opt_nflen; 488 489 rcu_read_unlock(); 490 return len; 491 } 492 493 /* Initialize a sockaddr_storage from in incoming skb. */ 494 static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb, 495 int is_saddr) 496 { 497 /* Always called on head skb, so this is safe */ 498 struct sctphdr *sh = sctp_hdr(skb); 499 struct sockaddr_in6 *sa = &addr->v6; 500 501 addr->v6.sin6_family = AF_INET6; 502 addr->v6.sin6_flowinfo = 0; /* FIXME */ 503 addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif; 504 505 if (is_saddr) { 506 sa->sin6_port = sh->source; 507 sa->sin6_addr = ipv6_hdr(skb)->saddr; 508 } else { 509 sa->sin6_port = sh->dest; 510 sa->sin6_addr = ipv6_hdr(skb)->daddr; 511 } 512 } 513 514 /* Initialize an sctp_addr from a socket. */ 515 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk) 516 { 517 addr->v6.sin6_family = AF_INET6; 518 addr->v6.sin6_port = 0; 519 addr->v6.sin6_addr = sk->sk_v6_rcv_saddr; 520 } 521 522 /* Initialize sk->sk_rcv_saddr from sctp_addr. */ 523 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk) 524 { 525 if (addr->sa.sa_family == AF_INET) { 526 sk->sk_v6_rcv_saddr.s6_addr32[0] = 0; 527 sk->sk_v6_rcv_saddr.s6_addr32[1] = 0; 528 sk->sk_v6_rcv_saddr.s6_addr32[2] = htonl(0x0000ffff); 529 sk->sk_v6_rcv_saddr.s6_addr32[3] = 530 addr->v4.sin_addr.s_addr; 531 } else { 532 sk->sk_v6_rcv_saddr = addr->v6.sin6_addr; 533 } 534 } 535 536 /* Initialize sk->sk_daddr from sctp_addr. */ 537 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk) 538 { 539 if (addr->sa.sa_family == AF_INET) { 540 sk->sk_v6_daddr.s6_addr32[0] = 0; 541 sk->sk_v6_daddr.s6_addr32[1] = 0; 542 sk->sk_v6_daddr.s6_addr32[2] = htonl(0x0000ffff); 543 sk->sk_v6_daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr; 544 } else { 545 sk->sk_v6_daddr = addr->v6.sin6_addr; 546 } 547 } 548 549 /* Initialize a sctp_addr from an address parameter. */ 550 static void sctp_v6_from_addr_param(union sctp_addr *addr, 551 union sctp_addr_param *param, 552 __be16 port, int iif) 553 { 554 addr->v6.sin6_family = AF_INET6; 555 addr->v6.sin6_port = port; 556 addr->v6.sin6_flowinfo = 0; /* BUG */ 557 addr->v6.sin6_addr = param->v6.addr; 558 addr->v6.sin6_scope_id = iif; 559 } 560 561 /* Initialize an address parameter from a sctp_addr and return the length 562 * of the address parameter. 563 */ 564 static int sctp_v6_to_addr_param(const union sctp_addr *addr, 565 union sctp_addr_param *param) 566 { 567 int length = sizeof(struct sctp_ipv6addr_param); 568 569 param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS; 570 param->v6.param_hdr.length = htons(length); 571 param->v6.addr = addr->v6.sin6_addr; 572 573 return length; 574 } 575 576 /* Initialize a sctp_addr from struct in6_addr. */ 577 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr, 578 __be16 port) 579 { 580 addr->sa.sa_family = AF_INET6; 581 addr->v6.sin6_port = port; 582 addr->v6.sin6_flowinfo = 0; 583 addr->v6.sin6_addr = *saddr; 584 addr->v6.sin6_scope_id = 0; 585 } 586 587 static int __sctp_v6_cmp_addr(const union sctp_addr *addr1, 588 const union sctp_addr *addr2) 589 { 590 if (addr1->sa.sa_family != addr2->sa.sa_family) { 591 if (addr1->sa.sa_family == AF_INET && 592 addr2->sa.sa_family == AF_INET6 && 593 ipv6_addr_v4mapped(&addr2->v6.sin6_addr) && 594 addr2->v6.sin6_addr.s6_addr32[3] == 595 addr1->v4.sin_addr.s_addr) 596 return 1; 597 598 if (addr2->sa.sa_family == AF_INET && 599 addr1->sa.sa_family == AF_INET6 && 600 ipv6_addr_v4mapped(&addr1->v6.sin6_addr) && 601 addr1->v6.sin6_addr.s6_addr32[3] == 602 addr2->v4.sin_addr.s_addr) 603 return 1; 604 605 return 0; 606 } 607 608 if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr)) 609 return 0; 610 611 /* If this is a linklocal address, compare the scope_id. */ 612 if ((ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) && 613 addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id && 614 addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id) 615 return 0; 616 617 return 1; 618 } 619 620 /* Compare addresses exactly. 621 * v4-mapped-v6 is also in consideration. 622 */ 623 static int sctp_v6_cmp_addr(const union sctp_addr *addr1, 624 const union sctp_addr *addr2) 625 { 626 return __sctp_v6_cmp_addr(addr1, addr2) && 627 addr1->v6.sin6_port == addr2->v6.sin6_port; 628 } 629 630 /* Initialize addr struct to INADDR_ANY. */ 631 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port) 632 { 633 memset(addr, 0x00, sizeof(union sctp_addr)); 634 addr->v6.sin6_family = AF_INET6; 635 addr->v6.sin6_port = port; 636 } 637 638 /* Is this a wildcard address? */ 639 static int sctp_v6_is_any(const union sctp_addr *addr) 640 { 641 return ipv6_addr_any(&addr->v6.sin6_addr); 642 } 643 644 /* Should this be available for binding? */ 645 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp) 646 { 647 int type; 648 struct net *net = sock_net(&sp->inet.sk); 649 const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr; 650 651 type = ipv6_addr_type(in6); 652 if (IPV6_ADDR_ANY == type) 653 return 1; 654 if (type == IPV6_ADDR_MAPPED) { 655 if (sp && ipv6_only_sock(sctp_opt2sk(sp))) 656 return 0; 657 sctp_v6_map_v4(addr); 658 return sctp_get_af_specific(AF_INET)->available(addr, sp); 659 } 660 if (!(type & IPV6_ADDR_UNICAST)) 661 return 0; 662 663 return ipv6_can_nonlocal_bind(net, &sp->inet) || 664 ipv6_chk_addr(net, in6, NULL, 0); 665 } 666 667 /* This function checks if the address is a valid address to be used for 668 * SCTP. 669 * 670 * Output: 671 * Return 0 - If the address is a non-unicast or an illegal address. 672 * Return 1 - If the address is a unicast. 673 */ 674 static int sctp_v6_addr_valid(union sctp_addr *addr, 675 struct sctp_sock *sp, 676 const struct sk_buff *skb) 677 { 678 int ret = ipv6_addr_type(&addr->v6.sin6_addr); 679 680 /* Support v4-mapped-v6 address. */ 681 if (ret == IPV6_ADDR_MAPPED) { 682 /* Note: This routine is used in input, so v4-mapped-v6 683 * are disallowed here when there is no sctp_sock. 684 */ 685 if (sp && ipv6_only_sock(sctp_opt2sk(sp))) 686 return 0; 687 sctp_v6_map_v4(addr); 688 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb); 689 } 690 691 /* Is this a non-unicast address */ 692 if (!(ret & IPV6_ADDR_UNICAST)) 693 return 0; 694 695 return 1; 696 } 697 698 /* What is the scope of 'addr'? */ 699 static enum sctp_scope sctp_v6_scope(union sctp_addr *addr) 700 { 701 enum sctp_scope retval; 702 int v6scope; 703 704 /* The IPv6 scope is really a set of bit fields. 705 * See IFA_* in <net/if_inet6.h>. Map to a generic SCTP scope. 706 */ 707 708 v6scope = ipv6_addr_scope(&addr->v6.sin6_addr); 709 switch (v6scope) { 710 case IFA_HOST: 711 retval = SCTP_SCOPE_LOOPBACK; 712 break; 713 case IFA_LINK: 714 retval = SCTP_SCOPE_LINK; 715 break; 716 case IFA_SITE: 717 retval = SCTP_SCOPE_PRIVATE; 718 break; 719 default: 720 retval = SCTP_SCOPE_GLOBAL; 721 break; 722 } 723 724 return retval; 725 } 726 727 /* Create and initialize a new sk for the socket to be returned by accept(). */ 728 static struct sock *sctp_v6_create_accept_sk(struct sock *sk, 729 struct sctp_association *asoc, 730 bool kern) 731 { 732 struct sock *newsk; 733 struct ipv6_pinfo *newnp, *np = inet6_sk(sk); 734 struct sctp6_sock *newsctp6sk; 735 736 newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot, kern); 737 if (!newsk) 738 goto out; 739 740 sock_init_data(NULL, newsk); 741 742 sctp_copy_sock(newsk, sk, asoc); 743 sock_reset_flag(sk, SOCK_ZAPPED); 744 745 newsctp6sk = (struct sctp6_sock *)newsk; 746 inet_sk(newsk)->pinet6 = &newsctp6sk->inet6; 747 748 sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped; 749 750 newnp = inet6_sk(newsk); 751 752 memcpy(newnp, np, sizeof(struct ipv6_pinfo)); 753 newnp->ipv6_mc_list = NULL; 754 newnp->ipv6_ac_list = NULL; 755 newnp->ipv6_fl_list = NULL; 756 757 sctp_v6_copy_ip_options(sk, newsk); 758 759 /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname() 760 * and getpeername(). 761 */ 762 sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk); 763 764 newsk->sk_v6_rcv_saddr = sk->sk_v6_rcv_saddr; 765 766 sk_refcnt_debug_inc(newsk); 767 768 if (newsk->sk_prot->init(newsk)) { 769 sk_common_release(newsk); 770 newsk = NULL; 771 } 772 773 out: 774 return newsk; 775 } 776 777 /* Format a sockaddr for return to user space. This makes sure the return is 778 * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option. 779 */ 780 static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr) 781 { 782 if (sp->v4mapped) { 783 if (addr->sa.sa_family == AF_INET) 784 sctp_v4_map_v6(addr); 785 } else { 786 if (addr->sa.sa_family == AF_INET6 && 787 ipv6_addr_v4mapped(&addr->v6.sin6_addr)) 788 sctp_v6_map_v4(addr); 789 } 790 791 if (addr->sa.sa_family == AF_INET) { 792 memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero)); 793 return sizeof(struct sockaddr_in); 794 } 795 return sizeof(struct sockaddr_in6); 796 } 797 798 /* Where did this skb come from? */ 799 static int sctp_v6_skb_iif(const struct sk_buff *skb) 800 { 801 return IP6CB(skb)->iif; 802 } 803 804 /* Was this packet marked by Explicit Congestion Notification? */ 805 static int sctp_v6_is_ce(const struct sk_buff *skb) 806 { 807 return *((__u32 *)(ipv6_hdr(skb))) & (__force __u32)htonl(1 << 20); 808 } 809 810 /* Dump the v6 addr to the seq file. */ 811 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr) 812 { 813 seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr); 814 } 815 816 static void sctp_v6_ecn_capable(struct sock *sk) 817 { 818 inet6_sk(sk)->tclass |= INET_ECN_ECT_0; 819 } 820 821 /* Initialize a PF_INET msgname from a ulpevent. */ 822 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event, 823 char *msgname, int *addrlen) 824 { 825 union sctp_addr *addr; 826 struct sctp_association *asoc; 827 union sctp_addr *paddr; 828 829 if (!msgname) 830 return; 831 832 addr = (union sctp_addr *)msgname; 833 asoc = event->asoc; 834 paddr = &asoc->peer.primary_addr; 835 836 if (paddr->sa.sa_family == AF_INET) { 837 addr->v4.sin_family = AF_INET; 838 addr->v4.sin_port = htons(asoc->peer.port); 839 addr->v4.sin_addr = paddr->v4.sin_addr; 840 } else { 841 addr->v6.sin6_family = AF_INET6; 842 addr->v6.sin6_flowinfo = 0; 843 if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) 844 addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id; 845 else 846 addr->v6.sin6_scope_id = 0; 847 addr->v6.sin6_port = htons(asoc->peer.port); 848 addr->v6.sin6_addr = paddr->v6.sin6_addr; 849 } 850 851 *addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr); 852 } 853 854 /* Initialize a msg_name from an inbound skb. */ 855 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname, 856 int *addr_len) 857 { 858 union sctp_addr *addr; 859 struct sctphdr *sh; 860 861 if (!msgname) 862 return; 863 864 addr = (union sctp_addr *)msgname; 865 sh = sctp_hdr(skb); 866 867 if (ip_hdr(skb)->version == 4) { 868 addr->v4.sin_family = AF_INET; 869 addr->v4.sin_port = sh->source; 870 addr->v4.sin_addr.s_addr = ip_hdr(skb)->saddr; 871 } else { 872 addr->v6.sin6_family = AF_INET6; 873 addr->v6.sin6_flowinfo = 0; 874 addr->v6.sin6_port = sh->source; 875 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr; 876 if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) 877 addr->v6.sin6_scope_id = sctp_v6_skb_iif(skb); 878 else 879 addr->v6.sin6_scope_id = 0; 880 } 881 882 *addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr); 883 } 884 885 /* Do we support this AF? */ 886 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp) 887 { 888 switch (family) { 889 case AF_INET6: 890 return 1; 891 /* v4-mapped-v6 addresses */ 892 case AF_INET: 893 if (!__ipv6_only_sock(sctp_opt2sk(sp))) 894 return 1; 895 fallthrough; 896 default: 897 return 0; 898 } 899 } 900 901 /* Address matching with wildcards allowed. This extra level 902 * of indirection lets us choose whether a PF_INET6 should 903 * disallow any v4 addresses if we so choose. 904 */ 905 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1, 906 const union sctp_addr *addr2, 907 struct sctp_sock *opt) 908 { 909 struct sock *sk = sctp_opt2sk(opt); 910 struct sctp_af *af1, *af2; 911 912 af1 = sctp_get_af_specific(addr1->sa.sa_family); 913 af2 = sctp_get_af_specific(addr2->sa.sa_family); 914 915 if (!af1 || !af2) 916 return 0; 917 918 /* If the socket is IPv6 only, v4 addrs will not match */ 919 if (__ipv6_only_sock(sk) && af1 != af2) 920 return 0; 921 922 /* Today, wildcard AF_INET/AF_INET6. */ 923 if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2)) 924 return 1; 925 926 if (addr1->sa.sa_family == AF_INET && addr2->sa.sa_family == AF_INET) 927 return addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr; 928 929 return __sctp_v6_cmp_addr(addr1, addr2); 930 } 931 932 /* Verify that the provided sockaddr looks bindable. Common verification, 933 * has already been taken care of. 934 */ 935 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr) 936 { 937 struct sctp_af *af; 938 939 /* ASSERT: address family has already been verified. */ 940 if (addr->sa.sa_family != AF_INET6) 941 af = sctp_get_af_specific(addr->sa.sa_family); 942 else { 943 int type = ipv6_addr_type(&addr->v6.sin6_addr); 944 struct net_device *dev; 945 946 if (type & IPV6_ADDR_LINKLOCAL) { 947 struct net *net; 948 if (!addr->v6.sin6_scope_id) 949 return 0; 950 net = sock_net(&opt->inet.sk); 951 rcu_read_lock(); 952 dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id); 953 if (!dev || !(ipv6_can_nonlocal_bind(net, &opt->inet) || 954 ipv6_chk_addr(net, &addr->v6.sin6_addr, 955 dev, 0))) { 956 rcu_read_unlock(); 957 return 0; 958 } 959 rcu_read_unlock(); 960 } 961 962 af = opt->pf->af; 963 } 964 return af->available(addr, opt); 965 } 966 967 /* Verify that the provided sockaddr looks sendable. Common verification, 968 * has already been taken care of. 969 */ 970 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr) 971 { 972 struct sctp_af *af = NULL; 973 974 /* ASSERT: address family has already been verified. */ 975 if (addr->sa.sa_family != AF_INET6) 976 af = sctp_get_af_specific(addr->sa.sa_family); 977 else { 978 int type = ipv6_addr_type(&addr->v6.sin6_addr); 979 struct net_device *dev; 980 981 if (type & IPV6_ADDR_LINKLOCAL) { 982 if (!addr->v6.sin6_scope_id) 983 return 0; 984 rcu_read_lock(); 985 dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk), 986 addr->v6.sin6_scope_id); 987 rcu_read_unlock(); 988 if (!dev) 989 return 0; 990 } 991 af = opt->pf->af; 992 } 993 994 return af != NULL; 995 } 996 997 /* Fill in Supported Address Type information for INIT and INIT-ACK 998 * chunks. Note: In the future, we may want to look at sock options 999 * to determine whether a PF_INET6 socket really wants to have IPV4 1000 * addresses. 1001 * Returns number of addresses supported. 1002 */ 1003 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt, 1004 __be16 *types) 1005 { 1006 types[0] = SCTP_PARAM_IPV6_ADDRESS; 1007 if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) { 1008 types[1] = SCTP_PARAM_IPV4_ADDRESS; 1009 return 2; 1010 } 1011 return 1; 1012 } 1013 1014 /* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */ 1015 static int sctp_getname(struct socket *sock, struct sockaddr *uaddr, 1016 int peer) 1017 { 1018 int rc; 1019 1020 rc = inet6_getname(sock, uaddr, peer); 1021 1022 if (rc < 0) 1023 return rc; 1024 1025 rc = sctp_v6_addr_to_user(sctp_sk(sock->sk), 1026 (union sctp_addr *)uaddr); 1027 1028 return rc; 1029 } 1030 1031 static const struct proto_ops inet6_seqpacket_ops = { 1032 .family = PF_INET6, 1033 .owner = THIS_MODULE, 1034 .release = inet6_release, 1035 .bind = inet6_bind, 1036 .connect = sctp_inet_connect, 1037 .socketpair = sock_no_socketpair, 1038 .accept = inet_accept, 1039 .getname = sctp_getname, 1040 .poll = sctp_poll, 1041 .ioctl = inet6_ioctl, 1042 .gettstamp = sock_gettstamp, 1043 .listen = sctp_inet_listen, 1044 .shutdown = inet_shutdown, 1045 .setsockopt = sock_common_setsockopt, 1046 .getsockopt = sock_common_getsockopt, 1047 .sendmsg = inet_sendmsg, 1048 .recvmsg = inet_recvmsg, 1049 .mmap = sock_no_mmap, 1050 #ifdef CONFIG_COMPAT 1051 .compat_ioctl = inet6_compat_ioctl, 1052 #endif 1053 }; 1054 1055 static struct inet_protosw sctpv6_seqpacket_protosw = { 1056 .type = SOCK_SEQPACKET, 1057 .protocol = IPPROTO_SCTP, 1058 .prot = &sctpv6_prot, 1059 .ops = &inet6_seqpacket_ops, 1060 .flags = SCTP_PROTOSW_FLAG 1061 }; 1062 static struct inet_protosw sctpv6_stream_protosw = { 1063 .type = SOCK_STREAM, 1064 .protocol = IPPROTO_SCTP, 1065 .prot = &sctpv6_prot, 1066 .ops = &inet6_seqpacket_ops, 1067 .flags = SCTP_PROTOSW_FLAG, 1068 }; 1069 1070 static int sctp6_rcv(struct sk_buff *skb) 1071 { 1072 SCTP_INPUT_CB(skb)->encap_port = 0; 1073 return sctp_rcv(skb) ? -1 : 0; 1074 } 1075 1076 static const struct inet6_protocol sctpv6_protocol = { 1077 .handler = sctp6_rcv, 1078 .err_handler = sctp_v6_err, 1079 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL, 1080 }; 1081 1082 static struct sctp_af sctp_af_inet6 = { 1083 .sa_family = AF_INET6, 1084 .sctp_xmit = sctp_v6_xmit, 1085 .setsockopt = ipv6_setsockopt, 1086 .getsockopt = ipv6_getsockopt, 1087 .get_dst = sctp_v6_get_dst, 1088 .get_saddr = sctp_v6_get_saddr, 1089 .copy_addrlist = sctp_v6_copy_addrlist, 1090 .from_skb = sctp_v6_from_skb, 1091 .from_sk = sctp_v6_from_sk, 1092 .from_addr_param = sctp_v6_from_addr_param, 1093 .to_addr_param = sctp_v6_to_addr_param, 1094 .cmp_addr = sctp_v6_cmp_addr, 1095 .scope = sctp_v6_scope, 1096 .addr_valid = sctp_v6_addr_valid, 1097 .inaddr_any = sctp_v6_inaddr_any, 1098 .is_any = sctp_v6_is_any, 1099 .available = sctp_v6_available, 1100 .skb_iif = sctp_v6_skb_iif, 1101 .is_ce = sctp_v6_is_ce, 1102 .seq_dump_addr = sctp_v6_seq_dump_addr, 1103 .ecn_capable = sctp_v6_ecn_capable, 1104 .net_header_len = sizeof(struct ipv6hdr), 1105 .sockaddr_len = sizeof(struct sockaddr_in6), 1106 .ip_options_len = sctp_v6_ip_options_len, 1107 }; 1108 1109 static struct sctp_pf sctp_pf_inet6 = { 1110 .event_msgname = sctp_inet6_event_msgname, 1111 .skb_msgname = sctp_inet6_skb_msgname, 1112 .af_supported = sctp_inet6_af_supported, 1113 .cmp_addr = sctp_inet6_cmp_addr, 1114 .bind_verify = sctp_inet6_bind_verify, 1115 .send_verify = sctp_inet6_send_verify, 1116 .supported_addrs = sctp_inet6_supported_addrs, 1117 .create_accept_sk = sctp_v6_create_accept_sk, 1118 .addr_to_user = sctp_v6_addr_to_user, 1119 .to_sk_saddr = sctp_v6_to_sk_saddr, 1120 .to_sk_daddr = sctp_v6_to_sk_daddr, 1121 .copy_ip_options = sctp_v6_copy_ip_options, 1122 .af = &sctp_af_inet6, 1123 }; 1124 1125 /* Initialize IPv6 support and register with socket layer. */ 1126 void sctp_v6_pf_init(void) 1127 { 1128 /* Register the SCTP specific PF_INET6 functions. */ 1129 sctp_register_pf(&sctp_pf_inet6, PF_INET6); 1130 1131 /* Register the SCTP specific AF_INET6 functions. */ 1132 sctp_register_af(&sctp_af_inet6); 1133 } 1134 1135 void sctp_v6_pf_exit(void) 1136 { 1137 list_del(&sctp_af_inet6.list); 1138 } 1139 1140 /* Initialize IPv6 support and register with socket layer. */ 1141 int sctp_v6_protosw_init(void) 1142 { 1143 int rc; 1144 1145 rc = proto_register(&sctpv6_prot, 1); 1146 if (rc) 1147 return rc; 1148 1149 /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */ 1150 inet6_register_protosw(&sctpv6_seqpacket_protosw); 1151 inet6_register_protosw(&sctpv6_stream_protosw); 1152 1153 return 0; 1154 } 1155 1156 void sctp_v6_protosw_exit(void) 1157 { 1158 inet6_unregister_protosw(&sctpv6_seqpacket_protosw); 1159 inet6_unregister_protosw(&sctpv6_stream_protosw); 1160 proto_unregister(&sctpv6_prot); 1161 } 1162 1163 1164 /* Register with inet6 layer. */ 1165 int sctp_v6_add_protocol(void) 1166 { 1167 /* Register notifier for inet6 address additions/deletions. */ 1168 register_inet6addr_notifier(&sctp_inet6addr_notifier); 1169 1170 if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0) 1171 return -EAGAIN; 1172 1173 return 0; 1174 } 1175 1176 /* Unregister with inet6 layer. */ 1177 void sctp_v6_del_protocol(void) 1178 { 1179 inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP); 1180 unregister_inet6addr_notifier(&sctp_inet6addr_notifier); 1181 } 1182