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 inet_sk(newsk)->inet_opt = NULL; 496 497 newnp = inet6_sk(newsk); 498 499 rcu_read_lock(); 500 opt = rcu_dereference(np->opt); 501 if (opt) { 502 opt = ipv6_dup_options(newsk, opt); 503 if (!opt) 504 pr_err("%s: Failed to copy ip options\n", __func__); 505 } 506 RCU_INIT_POINTER(newnp->opt, opt); 507 rcu_read_unlock(); 508 } 509 510 /* Account for the IP options */ 511 static int sctp_v6_ip_options_len(struct sock *sk) 512 { 513 struct ipv6_pinfo *np = inet6_sk(sk); 514 struct ipv6_txoptions *opt; 515 int len = 0; 516 517 rcu_read_lock(); 518 opt = rcu_dereference(np->opt); 519 if (opt) 520 len = opt->opt_flen + opt->opt_nflen; 521 522 rcu_read_unlock(); 523 return len; 524 } 525 526 /* Initialize a sockaddr_storage from in incoming skb. */ 527 static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb, 528 int is_saddr) 529 { 530 /* Always called on head skb, so this is safe */ 531 struct sctphdr *sh = sctp_hdr(skb); 532 struct sockaddr_in6 *sa = &addr->v6; 533 534 addr->v6.sin6_family = AF_INET6; 535 addr->v6.sin6_flowinfo = 0; /* FIXME */ 536 addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif; 537 538 if (is_saddr) { 539 sa->sin6_port = sh->source; 540 sa->sin6_addr = ipv6_hdr(skb)->saddr; 541 } else { 542 sa->sin6_port = sh->dest; 543 sa->sin6_addr = ipv6_hdr(skb)->daddr; 544 } 545 } 546 547 /* Initialize an sctp_addr from a socket. */ 548 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk) 549 { 550 addr->v6.sin6_family = AF_INET6; 551 addr->v6.sin6_port = 0; 552 addr->v6.sin6_flowinfo = 0; 553 addr->v6.sin6_addr = sk->sk_v6_rcv_saddr; 554 addr->v6.sin6_scope_id = 0; 555 } 556 557 /* Initialize sk->sk_rcv_saddr from sctp_addr. */ 558 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk) 559 { 560 if (addr->sa.sa_family == AF_INET) { 561 sk->sk_v6_rcv_saddr.s6_addr32[0] = 0; 562 sk->sk_v6_rcv_saddr.s6_addr32[1] = 0; 563 sk->sk_v6_rcv_saddr.s6_addr32[2] = htonl(0x0000ffff); 564 sk->sk_v6_rcv_saddr.s6_addr32[3] = 565 addr->v4.sin_addr.s_addr; 566 } else { 567 sk->sk_v6_rcv_saddr = addr->v6.sin6_addr; 568 } 569 } 570 571 /* Initialize sk->sk_daddr from sctp_addr. */ 572 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk) 573 { 574 if (addr->sa.sa_family == AF_INET) { 575 sk->sk_v6_daddr.s6_addr32[0] = 0; 576 sk->sk_v6_daddr.s6_addr32[1] = 0; 577 sk->sk_v6_daddr.s6_addr32[2] = htonl(0x0000ffff); 578 sk->sk_v6_daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr; 579 } else { 580 sk->sk_v6_daddr = addr->v6.sin6_addr; 581 } 582 } 583 584 /* Initialize a sctp_addr from an address parameter. */ 585 static bool sctp_v6_from_addr_param(union sctp_addr *addr, 586 union sctp_addr_param *param, 587 __be16 port, int iif) 588 { 589 if (ntohs(param->v6.param_hdr.length) < sizeof(struct sctp_ipv6addr_param)) 590 return false; 591 592 addr->v6.sin6_family = AF_INET6; 593 addr->v6.sin6_port = port; 594 addr->v6.sin6_flowinfo = 0; /* BUG */ 595 addr->v6.sin6_addr = param->v6.addr; 596 addr->v6.sin6_scope_id = iif; 597 598 return true; 599 } 600 601 /* Initialize an address parameter from a sctp_addr and return the length 602 * of the address parameter. 603 */ 604 static int sctp_v6_to_addr_param(const union sctp_addr *addr, 605 union sctp_addr_param *param) 606 { 607 int length = sizeof(struct sctp_ipv6addr_param); 608 609 param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS; 610 param->v6.param_hdr.length = htons(length); 611 param->v6.addr = addr->v6.sin6_addr; 612 613 return length; 614 } 615 616 /* Initialize a sctp_addr from struct in6_addr. */ 617 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr, 618 __be16 port) 619 { 620 addr->sa.sa_family = AF_INET6; 621 addr->v6.sin6_port = port; 622 addr->v6.sin6_flowinfo = 0; 623 addr->v6.sin6_addr = *saddr; 624 addr->v6.sin6_scope_id = 0; 625 } 626 627 static int __sctp_v6_cmp_addr(const union sctp_addr *addr1, 628 const union sctp_addr *addr2) 629 { 630 if (addr1->sa.sa_family != addr2->sa.sa_family) { 631 if (addr1->sa.sa_family == AF_INET && 632 addr2->sa.sa_family == AF_INET6 && 633 ipv6_addr_v4mapped(&addr2->v6.sin6_addr) && 634 addr2->v6.sin6_addr.s6_addr32[3] == 635 addr1->v4.sin_addr.s_addr) 636 return 1; 637 638 if (addr2->sa.sa_family == AF_INET && 639 addr1->sa.sa_family == AF_INET6 && 640 ipv6_addr_v4mapped(&addr1->v6.sin6_addr) && 641 addr1->v6.sin6_addr.s6_addr32[3] == 642 addr2->v4.sin_addr.s_addr) 643 return 1; 644 645 return 0; 646 } 647 648 if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr)) 649 return 0; 650 651 /* If this is a linklocal address, compare the scope_id. */ 652 if ((ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) && 653 addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id && 654 addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id) 655 return 0; 656 657 return 1; 658 } 659 660 /* Compare addresses exactly. 661 * v4-mapped-v6 is also in consideration. 662 */ 663 static int sctp_v6_cmp_addr(const union sctp_addr *addr1, 664 const union sctp_addr *addr2) 665 { 666 return __sctp_v6_cmp_addr(addr1, addr2) && 667 addr1->v6.sin6_port == addr2->v6.sin6_port; 668 } 669 670 /* Initialize addr struct to INADDR_ANY. */ 671 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port) 672 { 673 memset(addr, 0x00, sizeof(union sctp_addr)); 674 addr->v6.sin6_family = AF_INET6; 675 addr->v6.sin6_port = port; 676 } 677 678 /* Is this a wildcard address? */ 679 static int sctp_v6_is_any(const union sctp_addr *addr) 680 { 681 return ipv6_addr_any(&addr->v6.sin6_addr); 682 } 683 684 /* Should this be available for binding? */ 685 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp) 686 { 687 const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr; 688 struct sock *sk = &sp->inet.sk; 689 struct net *net = sock_net(sk); 690 struct net_device *dev = NULL; 691 int type, res, bound_dev_if; 692 693 type = ipv6_addr_type(in6); 694 if (IPV6_ADDR_ANY == type) 695 return 1; 696 if (type == IPV6_ADDR_MAPPED) { 697 if (sp && ipv6_only_sock(sctp_opt2sk(sp))) 698 return 0; 699 sctp_v6_map_v4(addr); 700 return sctp_get_af_specific(AF_INET)->available(addr, sp); 701 } 702 if (!(type & IPV6_ADDR_UNICAST)) 703 return 0; 704 705 rcu_read_lock(); 706 bound_dev_if = READ_ONCE(sk->sk_bound_dev_if); 707 if (bound_dev_if) { 708 res = 0; 709 dev = dev_get_by_index_rcu(net, bound_dev_if); 710 if (!dev) 711 goto out; 712 } 713 714 res = ipv6_can_nonlocal_bind(net, &sp->inet) || 715 ipv6_chk_addr(net, in6, dev, 0); 716 717 out: 718 rcu_read_unlock(); 719 return res; 720 } 721 722 /* This function checks if the address is a valid address to be used for 723 * SCTP. 724 * 725 * Output: 726 * Return 0 - If the address is a non-unicast or an illegal address. 727 * Return 1 - If the address is a unicast. 728 */ 729 static int sctp_v6_addr_valid(union sctp_addr *addr, 730 struct sctp_sock *sp, 731 const struct sk_buff *skb) 732 { 733 int ret = ipv6_addr_type(&addr->v6.sin6_addr); 734 735 /* Support v4-mapped-v6 address. */ 736 if (ret == IPV6_ADDR_MAPPED) { 737 /* Note: This routine is used in input, so v4-mapped-v6 738 * are disallowed here when there is no sctp_sock. 739 */ 740 if (sp && ipv6_only_sock(sctp_opt2sk(sp))) 741 return 0; 742 sctp_v6_map_v4(addr); 743 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb); 744 } 745 746 /* Is this a non-unicast address */ 747 if (!(ret & IPV6_ADDR_UNICAST)) 748 return 0; 749 750 return 1; 751 } 752 753 /* What is the scope of 'addr'? */ 754 static enum sctp_scope sctp_v6_scope(union sctp_addr *addr) 755 { 756 enum sctp_scope retval; 757 int v6scope; 758 759 /* The IPv6 scope is really a set of bit fields. 760 * See IFA_* in <net/if_inet6.h>. Map to a generic SCTP scope. 761 */ 762 763 v6scope = ipv6_addr_scope(&addr->v6.sin6_addr); 764 switch (v6scope) { 765 case IFA_HOST: 766 retval = SCTP_SCOPE_LOOPBACK; 767 break; 768 case IFA_LINK: 769 retval = SCTP_SCOPE_LINK; 770 break; 771 case IFA_SITE: 772 retval = SCTP_SCOPE_PRIVATE; 773 break; 774 default: 775 retval = SCTP_SCOPE_GLOBAL; 776 break; 777 } 778 779 return retval; 780 } 781 782 /* Format a sockaddr for return to user space. This makes sure the return is 783 * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option. 784 */ 785 static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr) 786 { 787 if (sp->v4mapped) { 788 if (addr->sa.sa_family == AF_INET) 789 sctp_v4_map_v6(addr); 790 } else { 791 if (addr->sa.sa_family == AF_INET6 && 792 ipv6_addr_v4mapped(&addr->v6.sin6_addr)) 793 sctp_v6_map_v4(addr); 794 } 795 796 if (addr->sa.sa_family == AF_INET) { 797 memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero)); 798 return sizeof(struct sockaddr_in); 799 } 800 return sizeof(struct sockaddr_in6); 801 } 802 803 /* Where did this skb come from? */ 804 static int sctp_v6_skb_iif(const struct sk_buff *skb) 805 { 806 return inet6_iif(skb); 807 } 808 809 static int sctp_v6_skb_sdif(const struct sk_buff *skb) 810 { 811 return inet6_sdif(skb); 812 } 813 814 /* Was this packet marked by Explicit Congestion Notification? */ 815 static int sctp_v6_is_ce(const struct sk_buff *skb) 816 { 817 return *((__u32 *)(ipv6_hdr(skb))) & (__force __u32)htonl(1 << 20); 818 } 819 820 /* Dump the v6 addr to the seq file. */ 821 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr) 822 { 823 seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr); 824 } 825 826 static void sctp_v6_ecn_capable(struct sock *sk) 827 { 828 inet6_sk(sk)->tclass |= INET_ECN_ECT_0; 829 } 830 831 /* Initialize a PF_INET msgname from a ulpevent. */ 832 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event, 833 char *msgname, int *addrlen) 834 { 835 union sctp_addr *addr; 836 struct sctp_association *asoc; 837 union sctp_addr *paddr; 838 839 if (!msgname) 840 return; 841 842 addr = (union sctp_addr *)msgname; 843 asoc = event->asoc; 844 paddr = &asoc->peer.primary_addr; 845 846 if (paddr->sa.sa_family == AF_INET) { 847 addr->v4.sin_family = AF_INET; 848 addr->v4.sin_port = htons(asoc->peer.port); 849 addr->v4.sin_addr = paddr->v4.sin_addr; 850 } else { 851 addr->v6.sin6_family = AF_INET6; 852 addr->v6.sin6_flowinfo = 0; 853 if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) 854 addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id; 855 else 856 addr->v6.sin6_scope_id = 0; 857 addr->v6.sin6_port = htons(asoc->peer.port); 858 addr->v6.sin6_addr = paddr->v6.sin6_addr; 859 } 860 861 *addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr); 862 } 863 864 /* Initialize a msg_name from an inbound skb. */ 865 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname, 866 int *addr_len) 867 { 868 union sctp_addr *addr; 869 struct sctphdr *sh; 870 871 if (!msgname) 872 return; 873 874 addr = (union sctp_addr *)msgname; 875 sh = sctp_hdr(skb); 876 877 if (ip_hdr(skb)->version == 4) { 878 addr->v4.sin_family = AF_INET; 879 addr->v4.sin_port = sh->source; 880 addr->v4.sin_addr.s_addr = ip_hdr(skb)->saddr; 881 } else { 882 addr->v6.sin6_family = AF_INET6; 883 addr->v6.sin6_flowinfo = 0; 884 addr->v6.sin6_port = sh->source; 885 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr; 886 if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) 887 addr->v6.sin6_scope_id = sctp_v6_skb_iif(skb); 888 else 889 addr->v6.sin6_scope_id = 0; 890 } 891 892 *addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr); 893 } 894 895 /* Do we support this AF? */ 896 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp) 897 { 898 switch (family) { 899 case AF_INET6: 900 return 1; 901 /* v4-mapped-v6 addresses */ 902 case AF_INET: 903 if (!ipv6_only_sock(sctp_opt2sk(sp))) 904 return 1; 905 fallthrough; 906 default: 907 return 0; 908 } 909 } 910 911 /* Address matching with wildcards allowed. This extra level 912 * of indirection lets us choose whether a PF_INET6 should 913 * disallow any v4 addresses if we so choose. 914 */ 915 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1, 916 const union sctp_addr *addr2, 917 struct sctp_sock *opt) 918 { 919 struct sock *sk = sctp_opt2sk(opt); 920 struct sctp_af *af1, *af2; 921 922 af1 = sctp_get_af_specific(addr1->sa.sa_family); 923 af2 = sctp_get_af_specific(addr2->sa.sa_family); 924 925 if (!af1 || !af2) 926 return 0; 927 928 /* If the socket is IPv6 only, v4 addrs will not match */ 929 if (ipv6_only_sock(sk) && af1 != af2) 930 return 0; 931 932 /* Today, wildcard AF_INET/AF_INET6. */ 933 if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2)) 934 return 1; 935 936 if (addr1->sa.sa_family == AF_INET && addr2->sa.sa_family == AF_INET) 937 return addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr; 938 939 return __sctp_v6_cmp_addr(addr1, addr2); 940 } 941 942 /* Verify that the provided sockaddr looks bindable. Common verification, 943 * has already been taken care of. 944 */ 945 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr) 946 { 947 struct sctp_af *af; 948 949 /* ASSERT: address family has already been verified. */ 950 if (addr->sa.sa_family != AF_INET6) 951 af = sctp_get_af_specific(addr->sa.sa_family); 952 else { 953 int type = ipv6_addr_type(&addr->v6.sin6_addr); 954 struct net_device *dev; 955 956 if (type & IPV6_ADDR_LINKLOCAL) { 957 struct net *net; 958 if (!addr->v6.sin6_scope_id) 959 return 0; 960 net = sock_net(&opt->inet.sk); 961 rcu_read_lock(); 962 dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id); 963 if (!dev || !(ipv6_can_nonlocal_bind(net, &opt->inet) || 964 ipv6_chk_addr(net, &addr->v6.sin6_addr, 965 dev, 0))) { 966 rcu_read_unlock(); 967 return 0; 968 } 969 rcu_read_unlock(); 970 } 971 972 af = opt->pf->af; 973 } 974 return af->available(addr, opt); 975 } 976 977 /* Verify that the provided sockaddr looks sendable. Common verification, 978 * has already been taken care of. 979 */ 980 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr) 981 { 982 struct sctp_af *af = NULL; 983 984 /* ASSERT: address family has already been verified. */ 985 if (addr->sa.sa_family != AF_INET6) 986 af = sctp_get_af_specific(addr->sa.sa_family); 987 else { 988 int type = ipv6_addr_type(&addr->v6.sin6_addr); 989 struct net_device *dev; 990 991 if (type & IPV6_ADDR_LINKLOCAL) { 992 if (!addr->v6.sin6_scope_id) 993 return 0; 994 rcu_read_lock(); 995 dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk), 996 addr->v6.sin6_scope_id); 997 rcu_read_unlock(); 998 if (!dev) 999 return 0; 1000 } 1001 af = opt->pf->af; 1002 } 1003 1004 return af != NULL; 1005 } 1006 1007 /* Fill in Supported Address Type information for INIT and INIT-ACK 1008 * chunks. Note: In the future, we may want to look at sock options 1009 * to determine whether a PF_INET6 socket really wants to have IPV4 1010 * addresses. 1011 * Returns number of addresses supported. 1012 */ 1013 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt, 1014 __be16 *types) 1015 { 1016 types[0] = SCTP_PARAM_IPV6_ADDRESS; 1017 if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) { 1018 types[1] = SCTP_PARAM_IPV4_ADDRESS; 1019 return 2; 1020 } 1021 return 1; 1022 } 1023 1024 /* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */ 1025 static int sctp_getname(struct socket *sock, struct sockaddr *uaddr, 1026 int peer) 1027 { 1028 int rc; 1029 1030 rc = inet6_getname(sock, uaddr, peer); 1031 1032 if (rc < 0) 1033 return rc; 1034 1035 rc = sctp_v6_addr_to_user(sctp_sk(sock->sk), 1036 (union sctp_addr *)uaddr); 1037 1038 return rc; 1039 } 1040 1041 static const struct proto_ops inet6_seqpacket_ops = { 1042 .family = PF_INET6, 1043 .owner = THIS_MODULE, 1044 .release = inet6_release, 1045 .bind = inet6_bind, 1046 .connect = sctp_inet_connect, 1047 .socketpair = sock_no_socketpair, 1048 .accept = inet_accept, 1049 .getname = sctp_getname, 1050 .poll = sctp_poll, 1051 .ioctl = inet6_ioctl, 1052 .gettstamp = sock_gettstamp, 1053 .listen = sctp_inet_listen, 1054 .shutdown = inet_shutdown, 1055 .setsockopt = sock_common_setsockopt, 1056 .getsockopt = sock_common_getsockopt, 1057 .sendmsg = inet_sendmsg, 1058 .recvmsg = inet_recvmsg, 1059 .mmap = sock_no_mmap, 1060 #ifdef CONFIG_COMPAT 1061 .compat_ioctl = inet6_compat_ioctl, 1062 #endif 1063 }; 1064 1065 static struct inet_protosw sctpv6_seqpacket_protosw = { 1066 .type = SOCK_SEQPACKET, 1067 .protocol = IPPROTO_SCTP, 1068 .prot = &sctpv6_prot, 1069 .ops = &inet6_seqpacket_ops, 1070 .flags = SCTP_PROTOSW_FLAG 1071 }; 1072 static struct inet_protosw sctpv6_stream_protosw = { 1073 .type = SOCK_STREAM, 1074 .protocol = IPPROTO_SCTP, 1075 .prot = &sctpv6_prot, 1076 .ops = &inet6_seqpacket_ops, 1077 .flags = SCTP_PROTOSW_FLAG, 1078 }; 1079 1080 static int sctp6_rcv(struct sk_buff *skb) 1081 { 1082 SCTP_INPUT_CB(skb)->encap_port = 0; 1083 return sctp_rcv(skb) ? -1 : 0; 1084 } 1085 1086 static const struct inet6_protocol sctpv6_protocol = { 1087 .handler = sctp6_rcv, 1088 .err_handler = sctp_v6_err, 1089 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL, 1090 }; 1091 1092 static struct sctp_af sctp_af_inet6 = { 1093 .sa_family = AF_INET6, 1094 .sctp_xmit = sctp_v6_xmit, 1095 .setsockopt = ipv6_setsockopt, 1096 .getsockopt = ipv6_getsockopt, 1097 .get_dst = sctp_v6_get_dst, 1098 .get_saddr = sctp_v6_get_saddr, 1099 .copy_addrlist = sctp_v6_copy_addrlist, 1100 .from_skb = sctp_v6_from_skb, 1101 .from_sk = sctp_v6_from_sk, 1102 .from_addr_param = sctp_v6_from_addr_param, 1103 .to_addr_param = sctp_v6_to_addr_param, 1104 .cmp_addr = sctp_v6_cmp_addr, 1105 .scope = sctp_v6_scope, 1106 .addr_valid = sctp_v6_addr_valid, 1107 .inaddr_any = sctp_v6_inaddr_any, 1108 .is_any = sctp_v6_is_any, 1109 .available = sctp_v6_available, 1110 .skb_iif = sctp_v6_skb_iif, 1111 .skb_sdif = sctp_v6_skb_sdif, 1112 .is_ce = sctp_v6_is_ce, 1113 .seq_dump_addr = sctp_v6_seq_dump_addr, 1114 .ecn_capable = sctp_v6_ecn_capable, 1115 .net_header_len = sizeof(struct ipv6hdr), 1116 .sockaddr_len = sizeof(struct sockaddr_in6), 1117 .ip_options_len = sctp_v6_ip_options_len, 1118 }; 1119 1120 static struct sctp_pf sctp_pf_inet6 = { 1121 .event_msgname = sctp_inet6_event_msgname, 1122 .skb_msgname = sctp_inet6_skb_msgname, 1123 .af_supported = sctp_inet6_af_supported, 1124 .cmp_addr = sctp_inet6_cmp_addr, 1125 .bind_verify = sctp_inet6_bind_verify, 1126 .send_verify = sctp_inet6_send_verify, 1127 .supported_addrs = sctp_inet6_supported_addrs, 1128 .addr_to_user = sctp_v6_addr_to_user, 1129 .to_sk_saddr = sctp_v6_to_sk_saddr, 1130 .to_sk_daddr = sctp_v6_to_sk_daddr, 1131 .copy_ip_options = sctp_v6_copy_ip_options, 1132 .af = &sctp_af_inet6, 1133 }; 1134 1135 /* Initialize IPv6 support and register with socket layer. */ 1136 void sctp_v6_pf_init(void) 1137 { 1138 /* Register the SCTP specific PF_INET6 functions. */ 1139 sctp_register_pf(&sctp_pf_inet6, PF_INET6); 1140 1141 /* Register the SCTP specific AF_INET6 functions. */ 1142 sctp_register_af(&sctp_af_inet6); 1143 } 1144 1145 void sctp_v6_pf_exit(void) 1146 { 1147 list_del(&sctp_af_inet6.list); 1148 } 1149 1150 /* Initialize IPv6 support and register with socket layer. */ 1151 int sctp_v6_protosw_init(void) 1152 { 1153 int rc; 1154 1155 rc = proto_register(&sctpv6_prot, 1); 1156 if (rc) 1157 return rc; 1158 1159 /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */ 1160 inet6_register_protosw(&sctpv6_seqpacket_protosw); 1161 inet6_register_protosw(&sctpv6_stream_protosw); 1162 1163 return 0; 1164 } 1165 1166 void sctp_v6_protosw_exit(void) 1167 { 1168 inet6_unregister_protosw(&sctpv6_seqpacket_protosw); 1169 inet6_unregister_protosw(&sctpv6_stream_protosw); 1170 proto_unregister(&sctpv6_prot); 1171 } 1172 1173 1174 /* Register with inet6 layer. */ 1175 int sctp_v6_add_protocol(void) 1176 { 1177 /* Register notifier for inet6 address additions/deletions. */ 1178 register_inet6addr_notifier(&sctp_inet6addr_notifier); 1179 1180 if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0) 1181 return -EAGAIN; 1182 1183 return 0; 1184 } 1185 1186 /* Unregister with inet6 layer. */ 1187 void sctp_v6_del_protocol(void) 1188 { 1189 inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP); 1190 unregister_inet6addr_notifier(&sctp_inet6addr_notifier); 1191 } 1192