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 addr->a.v6.sin6_scope_id == ifa->idev->dev->ifindex) { 106 found = 1; 107 addr->valid = 0; 108 list_del_rcu(&addr->list); 109 sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL); 110 break; 111 } 112 } 113 spin_unlock_bh(&net->sctp.local_addr_lock); 114 if (found) 115 kfree_rcu(addr, rcu); 116 break; 117 } 118 119 return NOTIFY_DONE; 120 } 121 122 static struct notifier_block sctp_inet6addr_notifier = { 123 .notifier_call = sctp_inet6addr_event, 124 }; 125 126 static void sctp_v6_err_handle(struct sctp_transport *t, struct sk_buff *skb, 127 __u8 type, __u8 code, __u32 info) 128 { 129 struct sctp_association *asoc = t->asoc; 130 struct sock *sk = asoc->base.sk; 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 icmpv6_err_convert(type, code, &err); 152 if (!sock_owned_by_user(sk) && inet6_test_bit(RECVERR6, sk)) { 153 sk->sk_err = err; 154 sk_error_report(sk); 155 } else { 156 WRITE_ONCE(sk->sk_err_soft, err); 157 } 158 } 159 160 /* ICMP error handler. */ 161 static int sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 162 u8 type, u8 code, int offset, __be32 info) 163 { 164 struct net *net = dev_net(skb->dev); 165 struct sctp_transport *transport; 166 struct sctp_association *asoc; 167 __u16 saveip, savesctp; 168 struct sock *sk; 169 170 /* Fix up skb to look at the embedded net header. */ 171 saveip = skb->network_header; 172 savesctp = skb->transport_header; 173 skb_reset_network_header(skb); 174 skb_set_transport_header(skb, offset); 175 sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &transport); 176 /* Put back, the original pointers. */ 177 skb->network_header = saveip; 178 skb->transport_header = savesctp; 179 if (!sk) { 180 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS); 181 return -ENOENT; 182 } 183 184 sctp_v6_err_handle(transport, skb, type, code, ntohl(info)); 185 sctp_err_finish(sk, transport); 186 187 return 0; 188 } 189 190 int sctp_udp_v6_err(struct sock *sk, struct sk_buff *skb) 191 { 192 struct net *net = dev_net(skb->dev); 193 struct sctp_association *asoc; 194 struct sctp_transport *t; 195 struct icmp6hdr *hdr; 196 __u32 info = 0; 197 198 skb->transport_header += sizeof(struct udphdr); 199 sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &t); 200 if (!sk) { 201 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS); 202 return -ENOENT; 203 } 204 205 skb->transport_header -= sizeof(struct udphdr); 206 hdr = (struct icmp6hdr *)(skb_network_header(skb) - sizeof(struct icmp6hdr)); 207 if (hdr->icmp6_type == NDISC_REDIRECT) { 208 /* can't be handled without outer ip6hdr known, leave it to udpv6_err */ 209 sctp_err_finish(sk, t); 210 return 0; 211 } 212 if (hdr->icmp6_type == ICMPV6_PKT_TOOBIG) 213 info = ntohl(hdr->icmp6_mtu); 214 sctp_v6_err_handle(t, skb, hdr->icmp6_type, hdr->icmp6_code, info); 215 216 sctp_err_finish(sk, t); 217 return 1; 218 } 219 220 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *t) 221 { 222 struct dst_entry *dst = dst_clone(t->dst); 223 struct flowi6 *fl6 = &t->fl.u.ip6; 224 struct sock *sk = skb->sk; 225 struct ipv6_pinfo *np = inet6_sk(sk); 226 __u8 tclass = np->tclass; 227 __be32 label; 228 229 pr_debug("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n", __func__, skb, 230 skb->len, &fl6->saddr, &fl6->daddr); 231 232 if (t->dscp & SCTP_DSCP_SET_MASK) 233 tclass = t->dscp & SCTP_DSCP_VAL_MASK; 234 235 if (INET_ECN_is_capable(tclass)) 236 IP6_ECN_flow_xmit(sk, fl6->flowlabel); 237 238 if (!(t->param_flags & SPP_PMTUD_ENABLE)) 239 skb->ignore_df = 1; 240 241 SCTP_INC_STATS(sock_net(sk), SCTP_MIB_OUTSCTPPACKS); 242 243 if (!t->encap_port || !sctp_sk(sk)->udp_port) { 244 int res; 245 246 skb_dst_set(skb, dst); 247 rcu_read_lock(); 248 res = ip6_xmit(sk, skb, fl6, sk->sk_mark, 249 rcu_dereference(np->opt), 250 tclass, READ_ONCE(sk->sk_priority)); 251 rcu_read_unlock(); 252 return res; 253 } 254 255 if (skb_is_gso(skb)) 256 skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL_CSUM; 257 258 skb->encapsulation = 1; 259 skb_reset_inner_mac_header(skb); 260 skb_reset_inner_transport_header(skb); 261 skb_set_inner_ipproto(skb, IPPROTO_SCTP); 262 label = ip6_make_flowlabel(sock_net(sk), skb, fl6->flowlabel, true, fl6); 263 264 udp_tunnel6_xmit_skb(dst, sk, skb, NULL, &fl6->saddr, &fl6->daddr, 265 tclass, ip6_dst_hoplimit(dst), label, 266 sctp_sk(sk)->udp_port, t->encap_port, false, 0); 267 return 0; 268 } 269 270 /* Returns the dst cache entry for the given source and destination ip 271 * addresses. 272 */ 273 static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr, 274 struct flowi *fl, struct sock *sk) 275 { 276 struct sctp_association *asoc = t->asoc; 277 struct dst_entry *dst = NULL; 278 struct flowi _fl; 279 struct flowi6 *fl6 = &_fl.u.ip6; 280 struct sctp_bind_addr *bp; 281 struct ipv6_pinfo *np = inet6_sk(sk); 282 struct sctp_sockaddr_entry *laddr; 283 union sctp_addr *daddr = &t->ipaddr; 284 union sctp_addr dst_saddr; 285 struct in6_addr *final_p, final; 286 enum sctp_scope scope; 287 __u8 matchlen = 0; 288 289 memset(&_fl, 0, sizeof(_fl)); 290 fl6->daddr = daddr->v6.sin6_addr; 291 fl6->fl6_dport = daddr->v6.sin6_port; 292 fl6->flowi6_proto = IPPROTO_SCTP; 293 if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) 294 fl6->flowi6_oif = daddr->v6.sin6_scope_id; 295 else if (asoc) 296 fl6->flowi6_oif = asoc->base.sk->sk_bound_dev_if; 297 if (t->flowlabel & SCTP_FLOWLABEL_SET_MASK) 298 fl6->flowlabel = htonl(t->flowlabel & SCTP_FLOWLABEL_VAL_MASK); 299 300 if (inet6_test_bit(SNDFLOW, sk) && 301 (fl6->flowlabel & IPV6_FLOWLABEL_MASK)) { 302 struct ip6_flowlabel *flowlabel; 303 304 flowlabel = fl6_sock_lookup(sk, fl6->flowlabel); 305 if (IS_ERR(flowlabel)) 306 goto out; 307 fl6_sock_release(flowlabel); 308 } 309 310 pr_debug("%s: dst=%pI6 ", __func__, &fl6->daddr); 311 312 if (asoc) 313 fl6->fl6_sport = htons(asoc->base.bind_addr.port); 314 315 if (saddr) { 316 fl6->saddr = saddr->v6.sin6_addr; 317 if (!fl6->fl6_sport) 318 fl6->fl6_sport = saddr->v6.sin6_port; 319 320 pr_debug("src=%pI6 - ", &fl6->saddr); 321 } 322 323 rcu_read_lock(); 324 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final); 325 rcu_read_unlock(); 326 327 dst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p); 328 if (!asoc || saddr) { 329 t->dst = dst; 330 memcpy(fl, &_fl, sizeof(_fl)); 331 goto out; 332 } 333 334 bp = &asoc->base.bind_addr; 335 scope = sctp_scope(daddr); 336 /* ip6_dst_lookup has filled in the fl6->saddr for us. Check 337 * to see if we can use it. 338 */ 339 if (!IS_ERR(dst)) { 340 /* Walk through the bind address list and look for a bind 341 * address that matches the source address of the returned dst. 342 */ 343 sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port)); 344 rcu_read_lock(); 345 list_for_each_entry_rcu(laddr, &bp->address_list, list) { 346 if (!laddr->valid || laddr->state == SCTP_ADDR_DEL || 347 (laddr->state != SCTP_ADDR_SRC && 348 !asoc->src_out_of_asoc_ok)) 349 continue; 350 351 /* Do not compare against v4 addrs */ 352 if ((laddr->a.sa.sa_family == AF_INET6) && 353 (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) { 354 rcu_read_unlock(); 355 t->dst = dst; 356 memcpy(fl, &_fl, sizeof(_fl)); 357 goto out; 358 } 359 } 360 rcu_read_unlock(); 361 /* None of the bound addresses match the source address of the 362 * dst. So release it. 363 */ 364 dst_release(dst); 365 dst = NULL; 366 } 367 368 /* Walk through the bind address list and try to get the 369 * best source address for a given destination. 370 */ 371 rcu_read_lock(); 372 list_for_each_entry_rcu(laddr, &bp->address_list, list) { 373 struct dst_entry *bdst; 374 __u8 bmatchlen; 375 376 if (!laddr->valid || 377 laddr->state != SCTP_ADDR_SRC || 378 laddr->a.sa.sa_family != AF_INET6 || 379 scope > sctp_scope(&laddr->a)) 380 continue; 381 382 fl6->saddr = laddr->a.v6.sin6_addr; 383 fl6->fl6_sport = laddr->a.v6.sin6_port; 384 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final); 385 bdst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p); 386 387 if (IS_ERR(bdst)) 388 continue; 389 390 if (ipv6_chk_addr(dev_net(bdst->dev), 391 &laddr->a.v6.sin6_addr, bdst->dev, 1)) { 392 if (!IS_ERR_OR_NULL(dst)) 393 dst_release(dst); 394 dst = bdst; 395 t->dst = dst; 396 memcpy(fl, &_fl, sizeof(_fl)); 397 break; 398 } 399 400 bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a); 401 if (matchlen > bmatchlen) { 402 dst_release(bdst); 403 continue; 404 } 405 406 if (!IS_ERR_OR_NULL(dst)) 407 dst_release(dst); 408 dst = bdst; 409 matchlen = bmatchlen; 410 t->dst = dst; 411 memcpy(fl, &_fl, sizeof(_fl)); 412 } 413 rcu_read_unlock(); 414 415 out: 416 if (!IS_ERR_OR_NULL(dst)) { 417 struct rt6_info *rt; 418 419 rt = dst_rt6_info(dst); 420 t->dst_cookie = rt6_get_cookie(rt); 421 pr_debug("rt6_dst:%pI6/%d rt6_src:%pI6\n", 422 &rt->rt6i_dst.addr, rt->rt6i_dst.plen, 423 &fl->u.ip6.saddr); 424 } else { 425 t->dst = NULL; 426 pr_debug("no route\n"); 427 } 428 } 429 430 /* Returns the number of consecutive initial bits that match in the 2 ipv6 431 * addresses. 432 */ 433 static inline int sctp_v6_addr_match_len(union sctp_addr *s1, 434 union sctp_addr *s2) 435 { 436 return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr); 437 } 438 439 /* Fills in the source address(saddr) based on the destination address(daddr) 440 * and asoc's bind address list. 441 */ 442 static void sctp_v6_get_saddr(struct sctp_sock *sk, 443 struct sctp_transport *t, 444 struct flowi *fl) 445 { 446 struct flowi6 *fl6 = &fl->u.ip6; 447 union sctp_addr *saddr = &t->saddr; 448 449 pr_debug("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst); 450 451 if (t->dst) { 452 saddr->v6.sin6_family = AF_INET6; 453 saddr->v6.sin6_addr = fl6->saddr; 454 } 455 } 456 457 /* Make a copy of all potential local addresses. */ 458 static void sctp_v6_copy_addrlist(struct list_head *addrlist, 459 struct net_device *dev) 460 { 461 struct inet6_dev *in6_dev; 462 struct inet6_ifaddr *ifp; 463 struct sctp_sockaddr_entry *addr; 464 465 rcu_read_lock(); 466 if ((in6_dev = __in6_dev_get(dev)) == NULL) { 467 rcu_read_unlock(); 468 return; 469 } 470 471 read_lock_bh(&in6_dev->lock); 472 list_for_each_entry(ifp, &in6_dev->addr_list, if_list) { 473 /* Add the address to the local list. */ 474 addr = kzalloc(sizeof(*addr), GFP_ATOMIC); 475 if (addr) { 476 addr->a.v6.sin6_family = AF_INET6; 477 addr->a.v6.sin6_addr = ifp->addr; 478 addr->a.v6.sin6_scope_id = dev->ifindex; 479 addr->valid = 1; 480 INIT_LIST_HEAD(&addr->list); 481 list_add_tail(&addr->list, addrlist); 482 } 483 } 484 485 read_unlock_bh(&in6_dev->lock); 486 rcu_read_unlock(); 487 } 488 489 /* Copy over any ip options */ 490 static void sctp_v6_copy_ip_options(struct sock *sk, struct sock *newsk) 491 { 492 struct ipv6_pinfo *newnp, *np = inet6_sk(sk); 493 struct ipv6_txoptions *opt; 494 495 newnp = inet6_sk(newsk); 496 497 rcu_read_lock(); 498 opt = rcu_dereference(np->opt); 499 if (opt) { 500 opt = ipv6_dup_options(newsk, opt); 501 if (!opt) 502 pr_err("%s: Failed to copy ip options\n", __func__); 503 } 504 RCU_INIT_POINTER(newnp->opt, opt); 505 rcu_read_unlock(); 506 } 507 508 /* Account for the IP options */ 509 static int sctp_v6_ip_options_len(struct sock *sk) 510 { 511 struct ipv6_pinfo *np = inet6_sk(sk); 512 struct ipv6_txoptions *opt; 513 int len = 0; 514 515 rcu_read_lock(); 516 opt = rcu_dereference(np->opt); 517 if (opt) 518 len = opt->opt_flen + opt->opt_nflen; 519 520 rcu_read_unlock(); 521 return len; 522 } 523 524 /* Initialize a sockaddr_storage from in incoming skb. */ 525 static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb, 526 int is_saddr) 527 { 528 /* Always called on head skb, so this is safe */ 529 struct sctphdr *sh = sctp_hdr(skb); 530 struct sockaddr_in6 *sa = &addr->v6; 531 532 addr->v6.sin6_family = AF_INET6; 533 addr->v6.sin6_flowinfo = 0; /* FIXME */ 534 addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif; 535 536 if (is_saddr) { 537 sa->sin6_port = sh->source; 538 sa->sin6_addr = ipv6_hdr(skb)->saddr; 539 } else { 540 sa->sin6_port = sh->dest; 541 sa->sin6_addr = ipv6_hdr(skb)->daddr; 542 } 543 } 544 545 /* Initialize an sctp_addr from a socket. */ 546 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk) 547 { 548 addr->v6.sin6_family = AF_INET6; 549 addr->v6.sin6_port = 0; 550 addr->v6.sin6_flowinfo = 0; 551 addr->v6.sin6_addr = sk->sk_v6_rcv_saddr; 552 addr->v6.sin6_scope_id = 0; 553 } 554 555 /* Initialize sk->sk_rcv_saddr from sctp_addr. */ 556 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk) 557 { 558 if (addr->sa.sa_family == AF_INET) { 559 sk->sk_v6_rcv_saddr.s6_addr32[0] = 0; 560 sk->sk_v6_rcv_saddr.s6_addr32[1] = 0; 561 sk->sk_v6_rcv_saddr.s6_addr32[2] = htonl(0x0000ffff); 562 sk->sk_v6_rcv_saddr.s6_addr32[3] = 563 addr->v4.sin_addr.s_addr; 564 } else { 565 sk->sk_v6_rcv_saddr = addr->v6.sin6_addr; 566 } 567 } 568 569 /* Initialize sk->sk_daddr from sctp_addr. */ 570 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk) 571 { 572 if (addr->sa.sa_family == AF_INET) { 573 sk->sk_v6_daddr.s6_addr32[0] = 0; 574 sk->sk_v6_daddr.s6_addr32[1] = 0; 575 sk->sk_v6_daddr.s6_addr32[2] = htonl(0x0000ffff); 576 sk->sk_v6_daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr; 577 } else { 578 sk->sk_v6_daddr = addr->v6.sin6_addr; 579 } 580 } 581 582 /* Initialize a sctp_addr from an address parameter. */ 583 static bool sctp_v6_from_addr_param(union sctp_addr *addr, 584 union sctp_addr_param *param, 585 __be16 port, int iif) 586 { 587 if (ntohs(param->v6.param_hdr.length) < sizeof(struct sctp_ipv6addr_param)) 588 return false; 589 590 addr->v6.sin6_family = AF_INET6; 591 addr->v6.sin6_port = port; 592 addr->v6.sin6_flowinfo = 0; /* BUG */ 593 addr->v6.sin6_addr = param->v6.addr; 594 addr->v6.sin6_scope_id = iif; 595 596 return true; 597 } 598 599 /* Initialize an address parameter from a sctp_addr and return the length 600 * of the address parameter. 601 */ 602 static int sctp_v6_to_addr_param(const union sctp_addr *addr, 603 union sctp_addr_param *param) 604 { 605 int length = sizeof(struct sctp_ipv6addr_param); 606 607 param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS; 608 param->v6.param_hdr.length = htons(length); 609 param->v6.addr = addr->v6.sin6_addr; 610 611 return length; 612 } 613 614 /* Initialize a sctp_addr from struct in6_addr. */ 615 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr, 616 __be16 port) 617 { 618 addr->sa.sa_family = AF_INET6; 619 addr->v6.sin6_port = port; 620 addr->v6.sin6_flowinfo = 0; 621 addr->v6.sin6_addr = *saddr; 622 addr->v6.sin6_scope_id = 0; 623 } 624 625 static int __sctp_v6_cmp_addr(const union sctp_addr *addr1, 626 const union sctp_addr *addr2) 627 { 628 if (addr1->sa.sa_family != addr2->sa.sa_family) { 629 if (addr1->sa.sa_family == AF_INET && 630 addr2->sa.sa_family == AF_INET6 && 631 ipv6_addr_v4mapped(&addr2->v6.sin6_addr) && 632 addr2->v6.sin6_addr.s6_addr32[3] == 633 addr1->v4.sin_addr.s_addr) 634 return 1; 635 636 if (addr2->sa.sa_family == AF_INET && 637 addr1->sa.sa_family == AF_INET6 && 638 ipv6_addr_v4mapped(&addr1->v6.sin6_addr) && 639 addr1->v6.sin6_addr.s6_addr32[3] == 640 addr2->v4.sin_addr.s_addr) 641 return 1; 642 643 return 0; 644 } 645 646 if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr)) 647 return 0; 648 649 /* If this is a linklocal address, compare the scope_id. */ 650 if ((ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) && 651 addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id && 652 addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id) 653 return 0; 654 655 return 1; 656 } 657 658 /* Compare addresses exactly. 659 * v4-mapped-v6 is also in consideration. 660 */ 661 static int sctp_v6_cmp_addr(const union sctp_addr *addr1, 662 const union sctp_addr *addr2) 663 { 664 return __sctp_v6_cmp_addr(addr1, addr2) && 665 addr1->v6.sin6_port == addr2->v6.sin6_port; 666 } 667 668 /* Initialize addr struct to INADDR_ANY. */ 669 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port) 670 { 671 memset(addr, 0x00, sizeof(union sctp_addr)); 672 addr->v6.sin6_family = AF_INET6; 673 addr->v6.sin6_port = port; 674 } 675 676 /* Is this a wildcard address? */ 677 static int sctp_v6_is_any(const union sctp_addr *addr) 678 { 679 return ipv6_addr_any(&addr->v6.sin6_addr); 680 } 681 682 /* Should this be available for binding? */ 683 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp) 684 { 685 const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr; 686 struct sock *sk = &sp->inet.sk; 687 struct net *net = sock_net(sk); 688 struct net_device *dev = NULL; 689 int type, res, bound_dev_if; 690 691 type = ipv6_addr_type(in6); 692 if (IPV6_ADDR_ANY == type) 693 return 1; 694 if (type == IPV6_ADDR_MAPPED) { 695 if (sp && ipv6_only_sock(sctp_opt2sk(sp))) 696 return 0; 697 sctp_v6_map_v4(addr); 698 return sctp_get_af_specific(AF_INET)->available(addr, sp); 699 } 700 if (!(type & IPV6_ADDR_UNICAST)) 701 return 0; 702 703 rcu_read_lock(); 704 bound_dev_if = READ_ONCE(sk->sk_bound_dev_if); 705 if (bound_dev_if) { 706 res = 0; 707 dev = dev_get_by_index_rcu(net, bound_dev_if); 708 if (!dev) 709 goto out; 710 } 711 712 res = ipv6_can_nonlocal_bind(net, &sp->inet) || 713 ipv6_chk_addr(net, in6, dev, 0); 714 715 out: 716 rcu_read_unlock(); 717 return res; 718 } 719 720 /* This function checks if the address is a valid address to be used for 721 * SCTP. 722 * 723 * Output: 724 * Return 0 - If the address is a non-unicast or an illegal address. 725 * Return 1 - If the address is a unicast. 726 */ 727 static int sctp_v6_addr_valid(union sctp_addr *addr, 728 struct sctp_sock *sp, 729 const struct sk_buff *skb) 730 { 731 int ret = ipv6_addr_type(&addr->v6.sin6_addr); 732 733 /* Support v4-mapped-v6 address. */ 734 if (ret == IPV6_ADDR_MAPPED) { 735 /* Note: This routine is used in input, so v4-mapped-v6 736 * are disallowed here when there is no sctp_sock. 737 */ 738 if (sp && ipv6_only_sock(sctp_opt2sk(sp))) 739 return 0; 740 sctp_v6_map_v4(addr); 741 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb); 742 } 743 744 /* Is this a non-unicast address */ 745 if (!(ret & IPV6_ADDR_UNICAST)) 746 return 0; 747 748 return 1; 749 } 750 751 /* What is the scope of 'addr'? */ 752 static enum sctp_scope sctp_v6_scope(union sctp_addr *addr) 753 { 754 enum sctp_scope retval; 755 int v6scope; 756 757 /* The IPv6 scope is really a set of bit fields. 758 * See IFA_* in <net/if_inet6.h>. Map to a generic SCTP scope. 759 */ 760 761 v6scope = ipv6_addr_scope(&addr->v6.sin6_addr); 762 switch (v6scope) { 763 case IFA_HOST: 764 retval = SCTP_SCOPE_LOOPBACK; 765 break; 766 case IFA_LINK: 767 retval = SCTP_SCOPE_LINK; 768 break; 769 case IFA_SITE: 770 retval = SCTP_SCOPE_PRIVATE; 771 break; 772 default: 773 retval = SCTP_SCOPE_GLOBAL; 774 break; 775 } 776 777 return retval; 778 } 779 780 /* Format a sockaddr for return to user space. This makes sure the return is 781 * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option. 782 */ 783 static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr) 784 { 785 if (sp->v4mapped) { 786 if (addr->sa.sa_family == AF_INET) 787 sctp_v4_map_v6(addr); 788 } else { 789 if (addr->sa.sa_family == AF_INET6 && 790 ipv6_addr_v4mapped(&addr->v6.sin6_addr)) 791 sctp_v6_map_v4(addr); 792 } 793 794 if (addr->sa.sa_family == AF_INET) { 795 memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero)); 796 return sizeof(struct sockaddr_in); 797 } 798 return sizeof(struct sockaddr_in6); 799 } 800 801 /* Where did this skb come from? */ 802 static int sctp_v6_skb_iif(const struct sk_buff *skb) 803 { 804 return inet6_iif(skb); 805 } 806 807 static int sctp_v6_skb_sdif(const struct sk_buff *skb) 808 { 809 return inet6_sdif(skb); 810 } 811 812 /* Was this packet marked by Explicit Congestion Notification? */ 813 static int sctp_v6_is_ce(const struct sk_buff *skb) 814 { 815 return *((__u32 *)(ipv6_hdr(skb))) & (__force __u32)htonl(1 << 20); 816 } 817 818 /* Dump the v6 addr to the seq file. */ 819 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr) 820 { 821 seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr); 822 } 823 824 static void sctp_v6_ecn_capable(struct sock *sk) 825 { 826 inet6_sk(sk)->tclass |= INET_ECN_ECT_0; 827 } 828 829 /* Initialize a PF_INET msgname from a ulpevent. */ 830 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event, 831 char *msgname, int *addrlen) 832 { 833 union sctp_addr *addr; 834 struct sctp_association *asoc; 835 union sctp_addr *paddr; 836 837 if (!msgname) 838 return; 839 840 addr = (union sctp_addr *)msgname; 841 asoc = event->asoc; 842 paddr = &asoc->peer.primary_addr; 843 844 if (paddr->sa.sa_family == AF_INET) { 845 addr->v4.sin_family = AF_INET; 846 addr->v4.sin_port = htons(asoc->peer.port); 847 addr->v4.sin_addr = paddr->v4.sin_addr; 848 } else { 849 addr->v6.sin6_family = AF_INET6; 850 addr->v6.sin6_flowinfo = 0; 851 if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) 852 addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id; 853 else 854 addr->v6.sin6_scope_id = 0; 855 addr->v6.sin6_port = htons(asoc->peer.port); 856 addr->v6.sin6_addr = paddr->v6.sin6_addr; 857 } 858 859 *addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr); 860 } 861 862 /* Initialize a msg_name from an inbound skb. */ 863 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname, 864 int *addr_len) 865 { 866 union sctp_addr *addr; 867 struct sctphdr *sh; 868 869 if (!msgname) 870 return; 871 872 addr = (union sctp_addr *)msgname; 873 sh = sctp_hdr(skb); 874 875 if (ip_hdr(skb)->version == 4) { 876 addr->v4.sin_family = AF_INET; 877 addr->v4.sin_port = sh->source; 878 addr->v4.sin_addr.s_addr = ip_hdr(skb)->saddr; 879 } else { 880 addr->v6.sin6_family = AF_INET6; 881 addr->v6.sin6_flowinfo = 0; 882 addr->v6.sin6_port = sh->source; 883 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr; 884 if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) 885 addr->v6.sin6_scope_id = sctp_v6_skb_iif(skb); 886 else 887 addr->v6.sin6_scope_id = 0; 888 } 889 890 *addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr); 891 } 892 893 /* Do we support this AF? */ 894 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp) 895 { 896 switch (family) { 897 case AF_INET6: 898 return 1; 899 /* v4-mapped-v6 addresses */ 900 case AF_INET: 901 if (!ipv6_only_sock(sctp_opt2sk(sp))) 902 return 1; 903 fallthrough; 904 default: 905 return 0; 906 } 907 } 908 909 /* Address matching with wildcards allowed. This extra level 910 * of indirection lets us choose whether a PF_INET6 should 911 * disallow any v4 addresses if we so choose. 912 */ 913 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1, 914 const union sctp_addr *addr2, 915 struct sctp_sock *opt) 916 { 917 struct sock *sk = sctp_opt2sk(opt); 918 struct sctp_af *af1, *af2; 919 920 af1 = sctp_get_af_specific(addr1->sa.sa_family); 921 af2 = sctp_get_af_specific(addr2->sa.sa_family); 922 923 if (!af1 || !af2) 924 return 0; 925 926 /* If the socket is IPv6 only, v4 addrs will not match */ 927 if (ipv6_only_sock(sk) && af1 != af2) 928 return 0; 929 930 /* Today, wildcard AF_INET/AF_INET6. */ 931 if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2)) 932 return 1; 933 934 if (addr1->sa.sa_family == AF_INET && addr2->sa.sa_family == AF_INET) 935 return addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr; 936 937 return __sctp_v6_cmp_addr(addr1, addr2); 938 } 939 940 /* Verify that the provided sockaddr looks bindable. Common verification, 941 * has already been taken care of. 942 */ 943 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr) 944 { 945 struct sctp_af *af; 946 947 /* ASSERT: address family has already been verified. */ 948 if (addr->sa.sa_family != AF_INET6) 949 af = sctp_get_af_specific(addr->sa.sa_family); 950 else { 951 int type = ipv6_addr_type(&addr->v6.sin6_addr); 952 struct net_device *dev; 953 954 if (type & IPV6_ADDR_LINKLOCAL) { 955 struct net *net; 956 if (!addr->v6.sin6_scope_id) 957 return 0; 958 net = sock_net(&opt->inet.sk); 959 rcu_read_lock(); 960 dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id); 961 if (!dev || !(ipv6_can_nonlocal_bind(net, &opt->inet) || 962 ipv6_chk_addr(net, &addr->v6.sin6_addr, 963 dev, 0))) { 964 rcu_read_unlock(); 965 return 0; 966 } 967 rcu_read_unlock(); 968 } 969 970 af = opt->pf->af; 971 } 972 return af->available(addr, opt); 973 } 974 975 /* Verify that the provided sockaddr looks sendable. Common verification, 976 * has already been taken care of. 977 */ 978 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr) 979 { 980 struct sctp_af *af = NULL; 981 982 /* ASSERT: address family has already been verified. */ 983 if (addr->sa.sa_family != AF_INET6) 984 af = sctp_get_af_specific(addr->sa.sa_family); 985 else { 986 int type = ipv6_addr_type(&addr->v6.sin6_addr); 987 struct net_device *dev; 988 989 if (type & IPV6_ADDR_LINKLOCAL) { 990 if (!addr->v6.sin6_scope_id) 991 return 0; 992 rcu_read_lock(); 993 dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk), 994 addr->v6.sin6_scope_id); 995 rcu_read_unlock(); 996 if (!dev) 997 return 0; 998 } 999 af = opt->pf->af; 1000 } 1001 1002 return af != NULL; 1003 } 1004 1005 /* Fill in Supported Address Type information for INIT and INIT-ACK 1006 * chunks. Note: In the future, we may want to look at sock options 1007 * to determine whether a PF_INET6 socket really wants to have IPV4 1008 * addresses. 1009 * Returns number of addresses supported. 1010 */ 1011 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt, 1012 __be16 *types) 1013 { 1014 types[0] = SCTP_PARAM_IPV6_ADDRESS; 1015 if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) { 1016 types[1] = SCTP_PARAM_IPV4_ADDRESS; 1017 return 2; 1018 } 1019 return 1; 1020 } 1021 1022 /* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */ 1023 static int sctp_getname(struct socket *sock, struct sockaddr *uaddr, 1024 int peer) 1025 { 1026 int rc; 1027 1028 rc = inet6_getname(sock, uaddr, peer); 1029 1030 if (rc < 0) 1031 return rc; 1032 1033 rc = sctp_v6_addr_to_user(sctp_sk(sock->sk), 1034 (union sctp_addr *)uaddr); 1035 1036 return rc; 1037 } 1038 1039 static const struct proto_ops inet6_seqpacket_ops = { 1040 .family = PF_INET6, 1041 .owner = THIS_MODULE, 1042 .release = inet6_release, 1043 .bind = inet6_bind, 1044 .connect = sctp_inet_connect, 1045 .socketpair = sock_no_socketpair, 1046 .accept = inet_accept, 1047 .getname = sctp_getname, 1048 .poll = sctp_poll, 1049 .ioctl = inet6_ioctl, 1050 .gettstamp = sock_gettstamp, 1051 .listen = sctp_inet_listen, 1052 .shutdown = inet_shutdown, 1053 .setsockopt = sock_common_setsockopt, 1054 .getsockopt = sock_common_getsockopt, 1055 .sendmsg = inet_sendmsg, 1056 .recvmsg = inet_recvmsg, 1057 .mmap = sock_no_mmap, 1058 #ifdef CONFIG_COMPAT 1059 .compat_ioctl = inet6_compat_ioctl, 1060 #endif 1061 }; 1062 1063 static struct inet_protosw sctpv6_seqpacket_protosw = { 1064 .type = SOCK_SEQPACKET, 1065 .protocol = IPPROTO_SCTP, 1066 .prot = &sctpv6_prot, 1067 .ops = &inet6_seqpacket_ops, 1068 .flags = SCTP_PROTOSW_FLAG 1069 }; 1070 static struct inet_protosw sctpv6_stream_protosw = { 1071 .type = SOCK_STREAM, 1072 .protocol = IPPROTO_SCTP, 1073 .prot = &sctpv6_prot, 1074 .ops = &inet6_seqpacket_ops, 1075 .flags = SCTP_PROTOSW_FLAG, 1076 }; 1077 1078 static int sctp6_rcv(struct sk_buff *skb) 1079 { 1080 SCTP_INPUT_CB(skb)->encap_port = 0; 1081 return sctp_rcv(skb) ? -1 : 0; 1082 } 1083 1084 static const struct inet6_protocol sctpv6_protocol = { 1085 .handler = sctp6_rcv, 1086 .err_handler = sctp_v6_err, 1087 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL, 1088 }; 1089 1090 static struct sctp_af sctp_af_inet6 = { 1091 .sa_family = AF_INET6, 1092 .sctp_xmit = sctp_v6_xmit, 1093 .setsockopt = ipv6_setsockopt, 1094 .getsockopt = ipv6_getsockopt, 1095 .get_dst = sctp_v6_get_dst, 1096 .get_saddr = sctp_v6_get_saddr, 1097 .copy_addrlist = sctp_v6_copy_addrlist, 1098 .from_skb = sctp_v6_from_skb, 1099 .from_sk = sctp_v6_from_sk, 1100 .from_addr_param = sctp_v6_from_addr_param, 1101 .to_addr_param = sctp_v6_to_addr_param, 1102 .cmp_addr = sctp_v6_cmp_addr, 1103 .scope = sctp_v6_scope, 1104 .addr_valid = sctp_v6_addr_valid, 1105 .inaddr_any = sctp_v6_inaddr_any, 1106 .is_any = sctp_v6_is_any, 1107 .available = sctp_v6_available, 1108 .skb_iif = sctp_v6_skb_iif, 1109 .skb_sdif = sctp_v6_skb_sdif, 1110 .is_ce = sctp_v6_is_ce, 1111 .seq_dump_addr = sctp_v6_seq_dump_addr, 1112 .ecn_capable = sctp_v6_ecn_capable, 1113 .net_header_len = sizeof(struct ipv6hdr), 1114 .sockaddr_len = sizeof(struct sockaddr_in6), 1115 .ip_options_len = sctp_v6_ip_options_len, 1116 }; 1117 1118 static struct sctp_pf sctp_pf_inet6 = { 1119 .event_msgname = sctp_inet6_event_msgname, 1120 .skb_msgname = sctp_inet6_skb_msgname, 1121 .af_supported = sctp_inet6_af_supported, 1122 .cmp_addr = sctp_inet6_cmp_addr, 1123 .bind_verify = sctp_inet6_bind_verify, 1124 .send_verify = sctp_inet6_send_verify, 1125 .supported_addrs = sctp_inet6_supported_addrs, 1126 .addr_to_user = sctp_v6_addr_to_user, 1127 .to_sk_saddr = sctp_v6_to_sk_saddr, 1128 .to_sk_daddr = sctp_v6_to_sk_daddr, 1129 .copy_ip_options = sctp_v6_copy_ip_options, 1130 .af = &sctp_af_inet6, 1131 }; 1132 1133 /* Initialize IPv6 support and register with socket layer. */ 1134 void sctp_v6_pf_init(void) 1135 { 1136 /* Register the SCTP specific PF_INET6 functions. */ 1137 sctp_register_pf(&sctp_pf_inet6, PF_INET6); 1138 1139 /* Register the SCTP specific AF_INET6 functions. */ 1140 sctp_register_af(&sctp_af_inet6); 1141 } 1142 1143 void sctp_v6_pf_exit(void) 1144 { 1145 list_del(&sctp_af_inet6.list); 1146 } 1147 1148 /* Initialize IPv6 support and register with socket layer. */ 1149 int sctp_v6_protosw_init(void) 1150 { 1151 int rc; 1152 1153 rc = proto_register(&sctpv6_prot, 1); 1154 if (rc) 1155 return rc; 1156 1157 /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */ 1158 inet6_register_protosw(&sctpv6_seqpacket_protosw); 1159 inet6_register_protosw(&sctpv6_stream_protosw); 1160 1161 return 0; 1162 } 1163 1164 void sctp_v6_protosw_exit(void) 1165 { 1166 inet6_unregister_protosw(&sctpv6_seqpacket_protosw); 1167 inet6_unregister_protosw(&sctpv6_stream_protosw); 1168 proto_unregister(&sctpv6_prot); 1169 } 1170 1171 1172 /* Register with inet6 layer. */ 1173 int sctp_v6_add_protocol(void) 1174 { 1175 /* Register notifier for inet6 address additions/deletions. */ 1176 register_inet6addr_notifier(&sctp_inet6addr_notifier); 1177 1178 if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0) 1179 return -EAGAIN; 1180 1181 return 0; 1182 } 1183 1184 /* Unregister with inet6 layer. */ 1185 void sctp_v6_del_protocol(void) 1186 { 1187 inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP); 1188 unregister_inet6addr_notifier(&sctp_inet6addr_notifier); 1189 } 1190