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_obj(*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 local_bh_disable(); 265 udp_tunnel6_xmit_skb(dst, sk, skb, NULL, &fl6->saddr, &fl6->daddr, 266 tclass, ip6_dst_hoplimit(dst), label, 267 sctp_sk(sk)->udp_port, t->encap_port, false, 0); 268 local_bh_enable(); 269 return 0; 270 } 271 272 /* Returns the dst cache entry for the given source and destination ip 273 * addresses. 274 */ 275 static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr, 276 struct flowi *fl, struct sock *sk) 277 { 278 struct sctp_association *asoc = t->asoc; 279 struct dst_entry *dst = NULL; 280 struct flowi _fl; 281 struct flowi6 *fl6 = &_fl.u.ip6; 282 struct sctp_bind_addr *bp; 283 struct ipv6_pinfo *np = inet6_sk(sk); 284 struct sctp_sockaddr_entry *laddr; 285 union sctp_addr *daddr = &t->ipaddr; 286 union sctp_addr dst_saddr; 287 struct in6_addr *final_p, final; 288 enum sctp_scope scope; 289 __u8 matchlen = 0; 290 291 memset(&_fl, 0, sizeof(_fl)); 292 fl6->daddr = daddr->v6.sin6_addr; 293 fl6->fl6_dport = daddr->v6.sin6_port; 294 fl6->flowi6_proto = IPPROTO_SCTP; 295 if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) 296 fl6->flowi6_oif = daddr->v6.sin6_scope_id; 297 else if (asoc) 298 fl6->flowi6_oif = asoc->base.sk->sk_bound_dev_if; 299 if (t->flowlabel & SCTP_FLOWLABEL_SET_MASK) 300 fl6->flowlabel = htonl(t->flowlabel & SCTP_FLOWLABEL_VAL_MASK); 301 302 if (inet6_test_bit(SNDFLOW, sk) && 303 (fl6->flowlabel & IPV6_FLOWLABEL_MASK)) { 304 struct ip6_flowlabel *flowlabel; 305 306 flowlabel = fl6_sock_lookup(sk, fl6->flowlabel); 307 if (IS_ERR(flowlabel)) 308 goto out; 309 fl6_sock_release(flowlabel); 310 } 311 312 pr_debug("%s: dst=%pI6 ", __func__, &fl6->daddr); 313 314 if (asoc) 315 fl6->fl6_sport = htons(asoc->base.bind_addr.port); 316 317 if (saddr) { 318 fl6->saddr = saddr->v6.sin6_addr; 319 if (!fl6->fl6_sport) 320 fl6->fl6_sport = saddr->v6.sin6_port; 321 322 pr_debug("src=%pI6 - ", &fl6->saddr); 323 } 324 325 rcu_read_lock(); 326 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final); 327 rcu_read_unlock(); 328 329 dst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p); 330 if (!asoc || saddr) { 331 t->dst = dst; 332 memcpy(fl, &_fl, sizeof(_fl)); 333 goto out; 334 } 335 336 bp = &asoc->base.bind_addr; 337 scope = sctp_scope(daddr); 338 /* ip6_dst_lookup has filled in the fl6->saddr for us. Check 339 * to see if we can use it. 340 */ 341 if (!IS_ERR(dst)) { 342 /* Walk through the bind address list and look for a bind 343 * address that matches the source address of the returned dst. 344 */ 345 sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port)); 346 rcu_read_lock(); 347 list_for_each_entry_rcu(laddr, &bp->address_list, list) { 348 if (!laddr->valid || laddr->state == SCTP_ADDR_DEL || 349 (laddr->state != SCTP_ADDR_SRC && 350 !asoc->src_out_of_asoc_ok)) 351 continue; 352 353 /* Do not compare against v4 addrs */ 354 if ((laddr->a.sa.sa_family == AF_INET6) && 355 (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) { 356 rcu_read_unlock(); 357 t->dst = dst; 358 memcpy(fl, &_fl, sizeof(_fl)); 359 goto out; 360 } 361 } 362 rcu_read_unlock(); 363 /* None of the bound addresses match the source address of the 364 * dst. So release it. 365 */ 366 dst_release(dst); 367 dst = NULL; 368 } 369 370 /* Walk through the bind address list and try to get the 371 * best source address for a given destination. 372 */ 373 rcu_read_lock(); 374 list_for_each_entry_rcu(laddr, &bp->address_list, list) { 375 struct dst_entry *bdst; 376 __u8 bmatchlen; 377 378 if (!laddr->valid || 379 laddr->state != SCTP_ADDR_SRC || 380 laddr->a.sa.sa_family != AF_INET6 || 381 scope > sctp_scope(&laddr->a)) 382 continue; 383 384 fl6->saddr = laddr->a.v6.sin6_addr; 385 fl6->fl6_sport = laddr->a.v6.sin6_port; 386 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final); 387 bdst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p); 388 389 if (IS_ERR(bdst)) 390 continue; 391 392 if (ipv6_chk_addr(dev_net(bdst->dev), 393 &laddr->a.v6.sin6_addr, bdst->dev, 1)) { 394 if (!IS_ERR_OR_NULL(dst)) 395 dst_release(dst); 396 dst = bdst; 397 t->dst = dst; 398 memcpy(fl, &_fl, sizeof(_fl)); 399 break; 400 } 401 402 bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a); 403 if (matchlen > bmatchlen) { 404 dst_release(bdst); 405 continue; 406 } 407 408 if (!IS_ERR_OR_NULL(dst)) 409 dst_release(dst); 410 dst = bdst; 411 matchlen = bmatchlen; 412 t->dst = dst; 413 memcpy(fl, &_fl, sizeof(_fl)); 414 } 415 rcu_read_unlock(); 416 417 out: 418 if (!IS_ERR_OR_NULL(dst)) { 419 struct rt6_info *rt; 420 421 rt = dst_rt6_info(dst); 422 t->dst_cookie = rt6_get_cookie(rt); 423 pr_debug("rt6_dst:%pI6/%d rt6_src:%pI6\n", 424 &rt->rt6i_dst.addr, rt->rt6i_dst.plen, 425 &fl->u.ip6.saddr); 426 } else { 427 t->dst = NULL; 428 pr_debug("no route\n"); 429 } 430 } 431 432 /* Returns the number of consecutive initial bits that match in the 2 ipv6 433 * addresses. 434 */ 435 static inline int sctp_v6_addr_match_len(union sctp_addr *s1, 436 union sctp_addr *s2) 437 { 438 return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr); 439 } 440 441 /* Fills in the source address(saddr) based on the destination address(daddr) 442 * and asoc's bind address list. 443 */ 444 static void sctp_v6_get_saddr(struct sctp_sock *sk, 445 struct sctp_transport *t, 446 struct flowi *fl) 447 { 448 struct flowi6 *fl6 = &fl->u.ip6; 449 union sctp_addr *saddr = &t->saddr; 450 451 pr_debug("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst); 452 453 if (t->dst) { 454 saddr->v6.sin6_family = AF_INET6; 455 saddr->v6.sin6_addr = fl6->saddr; 456 } 457 } 458 459 /* Make a copy of all potential local addresses. */ 460 static void sctp_v6_copy_addrlist(struct list_head *addrlist, 461 struct net_device *dev) 462 { 463 struct inet6_dev *in6_dev; 464 struct inet6_ifaddr *ifp; 465 struct sctp_sockaddr_entry *addr; 466 467 rcu_read_lock(); 468 if ((in6_dev = __in6_dev_get(dev)) == NULL) { 469 rcu_read_unlock(); 470 return; 471 } 472 473 read_lock_bh(&in6_dev->lock); 474 list_for_each_entry(ifp, &in6_dev->addr_list, if_list) { 475 /* Add the address to the local list. */ 476 addr = kzalloc_obj(*addr, GFP_ATOMIC); 477 if (addr) { 478 addr->a.v6.sin6_family = AF_INET6; 479 addr->a.v6.sin6_addr = ifp->addr; 480 addr->a.v6.sin6_scope_id = dev->ifindex; 481 addr->valid = 1; 482 INIT_LIST_HEAD(&addr->list); 483 list_add_tail(&addr->list, addrlist); 484 } 485 } 486 487 read_unlock_bh(&in6_dev->lock); 488 rcu_read_unlock(); 489 } 490 491 /* Copy over any ip options */ 492 static void sctp_v6_copy_ip_options(struct sock *sk, struct sock *newsk) 493 { 494 struct ipv6_pinfo *newnp, *np = inet6_sk(sk); 495 struct ipv6_txoptions *opt; 496 497 inet_sk(newsk)->inet_opt = NULL; 498 499 newnp = inet6_sk(newsk); 500 501 rcu_read_lock(); 502 opt = rcu_dereference(np->opt); 503 if (opt) { 504 opt = ipv6_dup_options(newsk, opt); 505 if (!opt) 506 pr_err("%s: Failed to copy ip options\n", __func__); 507 } 508 RCU_INIT_POINTER(newnp->opt, opt); 509 rcu_read_unlock(); 510 } 511 512 /* Account for the IP options */ 513 static int sctp_v6_ip_options_len(struct sock *sk) 514 { 515 struct ipv6_pinfo *np = inet6_sk(sk); 516 struct ipv6_txoptions *opt; 517 int len = 0; 518 519 rcu_read_lock(); 520 opt = rcu_dereference(np->opt); 521 if (opt) 522 len = opt->opt_flen + opt->opt_nflen; 523 524 rcu_read_unlock(); 525 return len; 526 } 527 528 /* Initialize a sockaddr_storage from in incoming skb. */ 529 static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb, 530 int is_saddr) 531 { 532 /* Always called on head skb, so this is safe */ 533 struct sctphdr *sh = sctp_hdr(skb); 534 struct sockaddr_in6 *sa = &addr->v6; 535 536 addr->v6.sin6_family = AF_INET6; 537 addr->v6.sin6_flowinfo = 0; /* FIXME */ 538 addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif; 539 540 if (is_saddr) { 541 sa->sin6_port = sh->source; 542 sa->sin6_addr = ipv6_hdr(skb)->saddr; 543 } else { 544 sa->sin6_port = sh->dest; 545 sa->sin6_addr = ipv6_hdr(skb)->daddr; 546 } 547 } 548 549 /* Initialize an sctp_addr from a socket. */ 550 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk) 551 { 552 addr->v6.sin6_family = AF_INET6; 553 addr->v6.sin6_port = 0; 554 addr->v6.sin6_flowinfo = 0; 555 addr->v6.sin6_addr = sk->sk_v6_rcv_saddr; 556 addr->v6.sin6_scope_id = 0; 557 } 558 559 /* Initialize sk->sk_rcv_saddr from sctp_addr. */ 560 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk) 561 { 562 if (addr->sa.sa_family == AF_INET) { 563 sk->sk_v6_rcv_saddr.s6_addr32[0] = 0; 564 sk->sk_v6_rcv_saddr.s6_addr32[1] = 0; 565 sk->sk_v6_rcv_saddr.s6_addr32[2] = htonl(0x0000ffff); 566 sk->sk_v6_rcv_saddr.s6_addr32[3] = 567 addr->v4.sin_addr.s_addr; 568 } else { 569 sk->sk_v6_rcv_saddr = addr->v6.sin6_addr; 570 } 571 } 572 573 /* Initialize sk->sk_daddr from sctp_addr. */ 574 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk) 575 { 576 if (addr->sa.sa_family == AF_INET) { 577 sk->sk_v6_daddr.s6_addr32[0] = 0; 578 sk->sk_v6_daddr.s6_addr32[1] = 0; 579 sk->sk_v6_daddr.s6_addr32[2] = htonl(0x0000ffff); 580 sk->sk_v6_daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr; 581 } else { 582 sk->sk_v6_daddr = addr->v6.sin6_addr; 583 } 584 } 585 586 /* Initialize a sctp_addr from an address parameter. */ 587 static bool sctp_v6_from_addr_param(union sctp_addr *addr, 588 union sctp_addr_param *param, 589 __be16 port, int iif) 590 { 591 if (ntohs(param->v6.param_hdr.length) < sizeof(struct sctp_ipv6addr_param)) 592 return false; 593 594 addr->v6.sin6_family = AF_INET6; 595 addr->v6.sin6_port = port; 596 addr->v6.sin6_flowinfo = 0; /* BUG */ 597 addr->v6.sin6_addr = param->v6.addr; 598 addr->v6.sin6_scope_id = iif; 599 600 return true; 601 } 602 603 /* Initialize an address parameter from a sctp_addr and return the length 604 * of the address parameter. 605 */ 606 static int sctp_v6_to_addr_param(const union sctp_addr *addr, 607 union sctp_addr_param *param) 608 { 609 int length = sizeof(struct sctp_ipv6addr_param); 610 611 param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS; 612 param->v6.param_hdr.length = htons(length); 613 param->v6.addr = addr->v6.sin6_addr; 614 615 return length; 616 } 617 618 /* Initialize a sctp_addr from struct in6_addr. */ 619 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr, 620 __be16 port) 621 { 622 addr->sa.sa_family = AF_INET6; 623 addr->v6.sin6_port = port; 624 addr->v6.sin6_flowinfo = 0; 625 addr->v6.sin6_addr = *saddr; 626 addr->v6.sin6_scope_id = 0; 627 } 628 629 static int __sctp_v6_cmp_addr(const union sctp_addr *addr1, 630 const union sctp_addr *addr2) 631 { 632 if (addr1->sa.sa_family != addr2->sa.sa_family) { 633 if (addr1->sa.sa_family == AF_INET && 634 addr2->sa.sa_family == AF_INET6 && 635 ipv6_addr_v4mapped(&addr2->v6.sin6_addr) && 636 addr2->v6.sin6_addr.s6_addr32[3] == 637 addr1->v4.sin_addr.s_addr) 638 return 1; 639 640 if (addr2->sa.sa_family == AF_INET && 641 addr1->sa.sa_family == AF_INET6 && 642 ipv6_addr_v4mapped(&addr1->v6.sin6_addr) && 643 addr1->v6.sin6_addr.s6_addr32[3] == 644 addr2->v4.sin_addr.s_addr) 645 return 1; 646 647 return 0; 648 } 649 650 if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr)) 651 return 0; 652 653 /* If this is a linklocal address, compare the scope_id. */ 654 if ((ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) && 655 addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id && 656 addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id) 657 return 0; 658 659 return 1; 660 } 661 662 /* Compare addresses exactly. 663 * v4-mapped-v6 is also in consideration. 664 */ 665 static int sctp_v6_cmp_addr(const union sctp_addr *addr1, 666 const union sctp_addr *addr2) 667 { 668 return __sctp_v6_cmp_addr(addr1, addr2) && 669 addr1->v6.sin6_port == addr2->v6.sin6_port; 670 } 671 672 /* Initialize addr struct to INADDR_ANY. */ 673 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port) 674 { 675 memset(addr, 0x00, sizeof(union sctp_addr)); 676 addr->v6.sin6_family = AF_INET6; 677 addr->v6.sin6_port = port; 678 } 679 680 /* Is this a wildcard address? */ 681 static int sctp_v6_is_any(const union sctp_addr *addr) 682 { 683 return ipv6_addr_any(&addr->v6.sin6_addr); 684 } 685 686 /* Should this be available for binding? */ 687 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp) 688 { 689 const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr; 690 struct sock *sk = &sp->inet.sk; 691 struct net *net = sock_net(sk); 692 struct net_device *dev = NULL; 693 int type, res, bound_dev_if; 694 695 type = ipv6_addr_type(in6); 696 if (IPV6_ADDR_ANY == type) 697 return 1; 698 if (type == IPV6_ADDR_MAPPED) { 699 if (sp && ipv6_only_sock(sctp_opt2sk(sp))) 700 return 0; 701 sctp_v6_map_v4(addr); 702 return sctp_get_af_specific(AF_INET)->available(addr, sp); 703 } 704 if (!(type & IPV6_ADDR_UNICAST)) 705 return 0; 706 707 rcu_read_lock(); 708 bound_dev_if = READ_ONCE(sk->sk_bound_dev_if); 709 if (bound_dev_if) { 710 res = 0; 711 dev = dev_get_by_index_rcu(net, bound_dev_if); 712 if (!dev) 713 goto out; 714 } 715 716 res = ipv6_can_nonlocal_bind(net, &sp->inet) || 717 ipv6_chk_addr(net, in6, dev, 0); 718 719 out: 720 rcu_read_unlock(); 721 return res; 722 } 723 724 /* This function checks if the address is a valid address to be used for 725 * SCTP. 726 * 727 * Output: 728 * Return 0 - If the address is a non-unicast or an illegal address. 729 * Return 1 - If the address is a unicast. 730 */ 731 static int sctp_v6_addr_valid(union sctp_addr *addr, 732 struct sctp_sock *sp, 733 const struct sk_buff *skb) 734 { 735 int ret = ipv6_addr_type(&addr->v6.sin6_addr); 736 737 /* Support v4-mapped-v6 address. */ 738 if (ret == IPV6_ADDR_MAPPED) { 739 /* Note: This routine is used in input, so v4-mapped-v6 740 * are disallowed here when there is no sctp_sock. 741 */ 742 if (sp && ipv6_only_sock(sctp_opt2sk(sp))) 743 return 0; 744 sctp_v6_map_v4(addr); 745 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb); 746 } 747 748 /* Is this a non-unicast address */ 749 if (!(ret & IPV6_ADDR_UNICAST)) 750 return 0; 751 752 return 1; 753 } 754 755 /* What is the scope of 'addr'? */ 756 static enum sctp_scope sctp_v6_scope(union sctp_addr *addr) 757 { 758 enum sctp_scope retval; 759 int v6scope; 760 761 /* The IPv6 scope is really a set of bit fields. 762 * See IFA_* in <net/if_inet6.h>. Map to a generic SCTP scope. 763 */ 764 765 v6scope = ipv6_addr_scope(&addr->v6.sin6_addr); 766 switch (v6scope) { 767 case IFA_HOST: 768 retval = SCTP_SCOPE_LOOPBACK; 769 break; 770 case IFA_LINK: 771 retval = SCTP_SCOPE_LINK; 772 break; 773 case IFA_SITE: 774 retval = SCTP_SCOPE_PRIVATE; 775 break; 776 default: 777 retval = SCTP_SCOPE_GLOBAL; 778 break; 779 } 780 781 return retval; 782 } 783 784 /* Format a sockaddr for return to user space. This makes sure the return is 785 * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option. 786 */ 787 static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr) 788 { 789 if (sp->v4mapped) { 790 if (addr->sa.sa_family == AF_INET) 791 sctp_v4_map_v6(addr); 792 } else { 793 if (addr->sa.sa_family == AF_INET6 && 794 ipv6_addr_v4mapped(&addr->v6.sin6_addr)) 795 sctp_v6_map_v4(addr); 796 } 797 798 if (addr->sa.sa_family == AF_INET) { 799 memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero)); 800 return sizeof(struct sockaddr_in); 801 } 802 return sizeof(struct sockaddr_in6); 803 } 804 805 /* Where did this skb come from? */ 806 static int sctp_v6_skb_iif(const struct sk_buff *skb) 807 { 808 return inet6_iif(skb); 809 } 810 811 static int sctp_v6_skb_sdif(const struct sk_buff *skb) 812 { 813 return inet6_sdif(skb); 814 } 815 816 /* Was this packet marked by Explicit Congestion Notification? */ 817 static int sctp_v6_is_ce(const struct sk_buff *skb) 818 { 819 return *((__u32 *)(ipv6_hdr(skb))) & (__force __u32)htonl(1 << 20); 820 } 821 822 /* Dump the v6 addr to the seq file. */ 823 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr) 824 { 825 seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr); 826 } 827 828 static void sctp_v6_ecn_capable(struct sock *sk) 829 { 830 inet6_sk(sk)->tclass |= INET_ECN_ECT_0; 831 } 832 833 /* Initialize a PF_INET msgname from a ulpevent. */ 834 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event, 835 char *msgname, int *addrlen) 836 { 837 union sctp_addr *addr; 838 struct sctp_association *asoc; 839 union sctp_addr *paddr; 840 841 if (!msgname) 842 return; 843 844 addr = (union sctp_addr *)msgname; 845 asoc = event->asoc; 846 paddr = &asoc->peer.primary_addr; 847 848 if (paddr->sa.sa_family == AF_INET) { 849 addr->v4.sin_family = AF_INET; 850 addr->v4.sin_port = htons(asoc->peer.port); 851 addr->v4.sin_addr = paddr->v4.sin_addr; 852 } else { 853 addr->v6.sin6_family = AF_INET6; 854 addr->v6.sin6_flowinfo = 0; 855 if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) 856 addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id; 857 else 858 addr->v6.sin6_scope_id = 0; 859 addr->v6.sin6_port = htons(asoc->peer.port); 860 addr->v6.sin6_addr = paddr->v6.sin6_addr; 861 } 862 863 *addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr); 864 } 865 866 /* Initialize a msg_name from an inbound skb. */ 867 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname, 868 int *addr_len) 869 { 870 union sctp_addr *addr; 871 struct sctphdr *sh; 872 873 if (!msgname) 874 return; 875 876 addr = (union sctp_addr *)msgname; 877 sh = sctp_hdr(skb); 878 879 if (ip_hdr(skb)->version == 4) { 880 addr->v4.sin_family = AF_INET; 881 addr->v4.sin_port = sh->source; 882 addr->v4.sin_addr.s_addr = ip_hdr(skb)->saddr; 883 } else { 884 addr->v6.sin6_family = AF_INET6; 885 addr->v6.sin6_flowinfo = 0; 886 addr->v6.sin6_port = sh->source; 887 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr; 888 if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) 889 addr->v6.sin6_scope_id = sctp_v6_skb_iif(skb); 890 else 891 addr->v6.sin6_scope_id = 0; 892 } 893 894 *addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr); 895 } 896 897 /* Do we support this AF? */ 898 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp) 899 { 900 switch (family) { 901 case AF_INET6: 902 return 1; 903 /* v4-mapped-v6 addresses */ 904 case AF_INET: 905 if (!ipv6_only_sock(sctp_opt2sk(sp))) 906 return 1; 907 fallthrough; 908 default: 909 return 0; 910 } 911 } 912 913 /* Address matching with wildcards allowed. This extra level 914 * of indirection lets us choose whether a PF_INET6 should 915 * disallow any v4 addresses if we so choose. 916 */ 917 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1, 918 const union sctp_addr *addr2, 919 struct sctp_sock *opt) 920 { 921 struct sock *sk = sctp_opt2sk(opt); 922 struct sctp_af *af1, *af2; 923 924 af1 = sctp_get_af_specific(addr1->sa.sa_family); 925 af2 = sctp_get_af_specific(addr2->sa.sa_family); 926 927 if (!af1 || !af2) 928 return 0; 929 930 /* If the socket is IPv6 only, v4 addrs will not match */ 931 if (ipv6_only_sock(sk) && af1 != af2) 932 return 0; 933 934 /* Today, wildcard AF_INET/AF_INET6. */ 935 if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2)) 936 return 1; 937 938 if (addr1->sa.sa_family == AF_INET && addr2->sa.sa_family == AF_INET) 939 return addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr; 940 941 return __sctp_v6_cmp_addr(addr1, addr2); 942 } 943 944 /* Verify that the provided sockaddr looks bindable. Common verification, 945 * has already been taken care of. 946 */ 947 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr) 948 { 949 struct sctp_af *af; 950 951 /* ASSERT: address family has already been verified. */ 952 if (addr->sa.sa_family != AF_INET6) 953 af = sctp_get_af_specific(addr->sa.sa_family); 954 else { 955 int type = ipv6_addr_type(&addr->v6.sin6_addr); 956 struct net_device *dev; 957 958 if (type & IPV6_ADDR_LINKLOCAL) { 959 struct net *net; 960 if (!addr->v6.sin6_scope_id) 961 return 0; 962 net = sock_net(&opt->inet.sk); 963 rcu_read_lock(); 964 dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id); 965 if (!dev || !(ipv6_can_nonlocal_bind(net, &opt->inet) || 966 ipv6_chk_addr(net, &addr->v6.sin6_addr, 967 dev, 0))) { 968 rcu_read_unlock(); 969 return 0; 970 } 971 rcu_read_unlock(); 972 } 973 974 af = opt->pf->af; 975 } 976 return af->available(addr, opt); 977 } 978 979 /* Verify that the provided sockaddr looks sendable. Common verification, 980 * has already been taken care of. 981 */ 982 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr) 983 { 984 struct sctp_af *af = NULL; 985 986 /* ASSERT: address family has already been verified. */ 987 if (addr->sa.sa_family != AF_INET6) 988 af = sctp_get_af_specific(addr->sa.sa_family); 989 else { 990 int type = ipv6_addr_type(&addr->v6.sin6_addr); 991 struct net_device *dev; 992 993 if (type & IPV6_ADDR_LINKLOCAL) { 994 if (!addr->v6.sin6_scope_id) 995 return 0; 996 rcu_read_lock(); 997 dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk), 998 addr->v6.sin6_scope_id); 999 rcu_read_unlock(); 1000 if (!dev) 1001 return 0; 1002 } 1003 af = opt->pf->af; 1004 } 1005 1006 return af != NULL; 1007 } 1008 1009 /* Fill in Supported Address Type information for INIT and INIT-ACK 1010 * chunks. Note: In the future, we may want to look at sock options 1011 * to determine whether a PF_INET6 socket really wants to have IPV4 1012 * addresses. 1013 * Returns number of addresses supported. 1014 */ 1015 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt, 1016 __be16 *types) 1017 { 1018 types[0] = SCTP_PARAM_IPV6_ADDRESS; 1019 if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) { 1020 types[1] = SCTP_PARAM_IPV4_ADDRESS; 1021 return 2; 1022 } 1023 return 1; 1024 } 1025 1026 /* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */ 1027 static int sctp_getname(struct socket *sock, struct sockaddr *uaddr, 1028 int peer) 1029 { 1030 int rc; 1031 1032 rc = inet6_getname(sock, uaddr, peer); 1033 1034 if (rc < 0) 1035 return rc; 1036 1037 rc = sctp_v6_addr_to_user(sctp_sk(sock->sk), 1038 (union sctp_addr *)uaddr); 1039 1040 return rc; 1041 } 1042 1043 static const struct proto_ops inet6_seqpacket_ops = { 1044 .family = PF_INET6, 1045 .owner = THIS_MODULE, 1046 .release = inet6_release, 1047 .bind = inet6_bind, 1048 .connect = sctp_inet_connect, 1049 .socketpair = sock_no_socketpair, 1050 .accept = inet_accept, 1051 .getname = sctp_getname, 1052 .poll = sctp_poll, 1053 .ioctl = inet6_ioctl, 1054 .gettstamp = sock_gettstamp, 1055 .listen = sctp_inet_listen, 1056 .shutdown = inet_shutdown, 1057 .setsockopt = sock_common_setsockopt, 1058 .getsockopt = sock_common_getsockopt, 1059 .sendmsg = inet_sendmsg, 1060 .recvmsg = inet_recvmsg, 1061 .mmap = sock_no_mmap, 1062 #ifdef CONFIG_COMPAT 1063 .compat_ioctl = inet6_compat_ioctl, 1064 #endif 1065 }; 1066 1067 static struct inet_protosw sctpv6_seqpacket_protosw = { 1068 .type = SOCK_SEQPACKET, 1069 .protocol = IPPROTO_SCTP, 1070 .prot = &sctpv6_prot, 1071 .ops = &inet6_seqpacket_ops, 1072 .flags = SCTP_PROTOSW_FLAG 1073 }; 1074 static struct inet_protosw sctpv6_stream_protosw = { 1075 .type = SOCK_STREAM, 1076 .protocol = IPPROTO_SCTP, 1077 .prot = &sctpv6_prot, 1078 .ops = &inet6_seqpacket_ops, 1079 .flags = SCTP_PROTOSW_FLAG, 1080 }; 1081 1082 static int sctp6_rcv(struct sk_buff *skb) 1083 { 1084 SCTP_INPUT_CB(skb)->encap_port = 0; 1085 return sctp_rcv(skb) ? -1 : 0; 1086 } 1087 1088 static const struct inet6_protocol sctpv6_protocol = { 1089 .handler = sctp6_rcv, 1090 .err_handler = sctp_v6_err, 1091 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL, 1092 }; 1093 1094 static struct sctp_af sctp_af_inet6 = { 1095 .sa_family = AF_INET6, 1096 .sctp_xmit = sctp_v6_xmit, 1097 .setsockopt = ipv6_setsockopt, 1098 .getsockopt = ipv6_getsockopt, 1099 .get_dst = sctp_v6_get_dst, 1100 .get_saddr = sctp_v6_get_saddr, 1101 .copy_addrlist = sctp_v6_copy_addrlist, 1102 .from_skb = sctp_v6_from_skb, 1103 .from_sk = sctp_v6_from_sk, 1104 .from_addr_param = sctp_v6_from_addr_param, 1105 .to_addr_param = sctp_v6_to_addr_param, 1106 .cmp_addr = sctp_v6_cmp_addr, 1107 .scope = sctp_v6_scope, 1108 .addr_valid = sctp_v6_addr_valid, 1109 .inaddr_any = sctp_v6_inaddr_any, 1110 .is_any = sctp_v6_is_any, 1111 .available = sctp_v6_available, 1112 .skb_iif = sctp_v6_skb_iif, 1113 .skb_sdif = sctp_v6_skb_sdif, 1114 .is_ce = sctp_v6_is_ce, 1115 .seq_dump_addr = sctp_v6_seq_dump_addr, 1116 .ecn_capable = sctp_v6_ecn_capable, 1117 .net_header_len = sizeof(struct ipv6hdr), 1118 .sockaddr_len = sizeof(struct sockaddr_in6), 1119 .ip_options_len = sctp_v6_ip_options_len, 1120 }; 1121 1122 static struct sctp_pf sctp_pf_inet6 = { 1123 .event_msgname = sctp_inet6_event_msgname, 1124 .skb_msgname = sctp_inet6_skb_msgname, 1125 .af_supported = sctp_inet6_af_supported, 1126 .cmp_addr = sctp_inet6_cmp_addr, 1127 .bind_verify = sctp_inet6_bind_verify, 1128 .send_verify = sctp_inet6_send_verify, 1129 .supported_addrs = sctp_inet6_supported_addrs, 1130 .addr_to_user = sctp_v6_addr_to_user, 1131 .to_sk_saddr = sctp_v6_to_sk_saddr, 1132 .to_sk_daddr = sctp_v6_to_sk_daddr, 1133 .copy_ip_options = sctp_v6_copy_ip_options, 1134 .af = &sctp_af_inet6, 1135 }; 1136 1137 /* Initialize IPv6 support and register with socket layer. */ 1138 void sctp_v6_pf_init(void) 1139 { 1140 /* Register the SCTP specific PF_INET6 functions. */ 1141 sctp_register_pf(&sctp_pf_inet6, PF_INET6); 1142 1143 /* Register the SCTP specific AF_INET6 functions. */ 1144 sctp_register_af(&sctp_af_inet6); 1145 } 1146 1147 void sctp_v6_pf_exit(void) 1148 { 1149 list_del(&sctp_af_inet6.list); 1150 } 1151 1152 /* Initialize IPv6 support and register with socket layer. */ 1153 int sctp_v6_protosw_init(void) 1154 { 1155 int rc; 1156 1157 rc = proto_register(&sctpv6_prot, 1); 1158 if (rc) 1159 return rc; 1160 1161 /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */ 1162 inet6_register_protosw(&sctpv6_seqpacket_protosw); 1163 inet6_register_protosw(&sctpv6_stream_protosw); 1164 1165 return 0; 1166 } 1167 1168 void sctp_v6_protosw_exit(void) 1169 { 1170 inet6_unregister_protosw(&sctpv6_seqpacket_protosw); 1171 inet6_unregister_protosw(&sctpv6_stream_protosw); 1172 proto_unregister(&sctpv6_prot); 1173 } 1174 1175 1176 /* Register with inet6 layer. */ 1177 int sctp_v6_add_protocol(void) 1178 { 1179 /* Register notifier for inet6 address additions/deletions. */ 1180 register_inet6addr_notifier(&sctp_inet6addr_notifier); 1181 1182 if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0) 1183 return -EAGAIN; 1184 1185 return 0; 1186 } 1187 1188 /* Unregister with inet6 layer. */ 1189 void sctp_v6_del_protocol(void) 1190 { 1191 inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP); 1192 unregister_inet6addr_notifier(&sctp_inet6addr_notifier); 1193 } 1194