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 return udp_tunnel6_xmit_skb(dst, sk, skb, NULL, &fl6->saddr, 265 &fl6->daddr, tclass, ip6_dst_hoplimit(dst), 266 label, sctp_sk(sk)->udp_port, t->encap_port, false); 267 } 268 269 /* Returns the dst cache entry for the given source and destination ip 270 * addresses. 271 */ 272 static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr, 273 struct flowi *fl, struct sock *sk) 274 { 275 struct sctp_association *asoc = t->asoc; 276 struct dst_entry *dst = NULL; 277 struct flowi _fl; 278 struct flowi6 *fl6 = &_fl.u.ip6; 279 struct sctp_bind_addr *bp; 280 struct ipv6_pinfo *np = inet6_sk(sk); 281 struct sctp_sockaddr_entry *laddr; 282 union sctp_addr *daddr = &t->ipaddr; 283 union sctp_addr dst_saddr; 284 struct in6_addr *final_p, final; 285 enum sctp_scope scope; 286 __u8 matchlen = 0; 287 288 memset(&_fl, 0, sizeof(_fl)); 289 fl6->daddr = daddr->v6.sin6_addr; 290 fl6->fl6_dport = daddr->v6.sin6_port; 291 fl6->flowi6_proto = IPPROTO_SCTP; 292 if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) 293 fl6->flowi6_oif = daddr->v6.sin6_scope_id; 294 else if (asoc) 295 fl6->flowi6_oif = asoc->base.sk->sk_bound_dev_if; 296 if (t->flowlabel & SCTP_FLOWLABEL_SET_MASK) 297 fl6->flowlabel = htonl(t->flowlabel & SCTP_FLOWLABEL_VAL_MASK); 298 299 if (inet6_test_bit(SNDFLOW, sk) && 300 (fl6->flowlabel & IPV6_FLOWLABEL_MASK)) { 301 struct ip6_flowlabel *flowlabel; 302 303 flowlabel = fl6_sock_lookup(sk, fl6->flowlabel); 304 if (IS_ERR(flowlabel)) 305 goto out; 306 fl6_sock_release(flowlabel); 307 } 308 309 pr_debug("%s: dst=%pI6 ", __func__, &fl6->daddr); 310 311 if (asoc) 312 fl6->fl6_sport = htons(asoc->base.bind_addr.port); 313 314 if (saddr) { 315 fl6->saddr = saddr->v6.sin6_addr; 316 if (!fl6->fl6_sport) 317 fl6->fl6_sport = saddr->v6.sin6_port; 318 319 pr_debug("src=%pI6 - ", &fl6->saddr); 320 } 321 322 rcu_read_lock(); 323 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final); 324 rcu_read_unlock(); 325 326 dst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p); 327 if (!asoc || saddr) { 328 t->dst = dst; 329 memcpy(fl, &_fl, sizeof(_fl)); 330 goto out; 331 } 332 333 bp = &asoc->base.bind_addr; 334 scope = sctp_scope(daddr); 335 /* ip6_dst_lookup has filled in the fl6->saddr for us. Check 336 * to see if we can use it. 337 */ 338 if (!IS_ERR(dst)) { 339 /* Walk through the bind address list and look for a bind 340 * address that matches the source address of the returned dst. 341 */ 342 sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port)); 343 rcu_read_lock(); 344 list_for_each_entry_rcu(laddr, &bp->address_list, list) { 345 if (!laddr->valid || laddr->state == SCTP_ADDR_DEL || 346 (laddr->state != SCTP_ADDR_SRC && 347 !asoc->src_out_of_asoc_ok)) 348 continue; 349 350 /* Do not compare against v4 addrs */ 351 if ((laddr->a.sa.sa_family == AF_INET6) && 352 (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) { 353 rcu_read_unlock(); 354 t->dst = dst; 355 memcpy(fl, &_fl, sizeof(_fl)); 356 goto out; 357 } 358 } 359 rcu_read_unlock(); 360 /* None of the bound addresses match the source address of the 361 * dst. So release it. 362 */ 363 dst_release(dst); 364 dst = NULL; 365 } 366 367 /* Walk through the bind address list and try to get the 368 * best source address for a given destination. 369 */ 370 rcu_read_lock(); 371 list_for_each_entry_rcu(laddr, &bp->address_list, list) { 372 struct dst_entry *bdst; 373 __u8 bmatchlen; 374 375 if (!laddr->valid || 376 laddr->state != SCTP_ADDR_SRC || 377 laddr->a.sa.sa_family != AF_INET6 || 378 scope > sctp_scope(&laddr->a)) 379 continue; 380 381 fl6->saddr = laddr->a.v6.sin6_addr; 382 fl6->fl6_sport = laddr->a.v6.sin6_port; 383 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final); 384 bdst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p); 385 386 if (IS_ERR(bdst)) 387 continue; 388 389 if (ipv6_chk_addr(dev_net(bdst->dev), 390 &laddr->a.v6.sin6_addr, bdst->dev, 1)) { 391 if (!IS_ERR_OR_NULL(dst)) 392 dst_release(dst); 393 dst = bdst; 394 t->dst = dst; 395 memcpy(fl, &_fl, sizeof(_fl)); 396 break; 397 } 398 399 bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a); 400 if (matchlen > bmatchlen) { 401 dst_release(bdst); 402 continue; 403 } 404 405 if (!IS_ERR_OR_NULL(dst)) 406 dst_release(dst); 407 dst = bdst; 408 matchlen = bmatchlen; 409 t->dst = dst; 410 memcpy(fl, &_fl, sizeof(_fl)); 411 } 412 rcu_read_unlock(); 413 414 out: 415 if (!IS_ERR_OR_NULL(dst)) { 416 struct rt6_info *rt; 417 418 rt = dst_rt6_info(dst); 419 t->dst_cookie = rt6_get_cookie(rt); 420 pr_debug("rt6_dst:%pI6/%d rt6_src:%pI6\n", 421 &rt->rt6i_dst.addr, rt->rt6i_dst.plen, 422 &fl->u.ip6.saddr); 423 } else { 424 t->dst = NULL; 425 pr_debug("no route\n"); 426 } 427 } 428 429 /* Returns the number of consecutive initial bits that match in the 2 ipv6 430 * addresses. 431 */ 432 static inline int sctp_v6_addr_match_len(union sctp_addr *s1, 433 union sctp_addr *s2) 434 { 435 return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr); 436 } 437 438 /* Fills in the source address(saddr) based on the destination address(daddr) 439 * and asoc's bind address list. 440 */ 441 static void sctp_v6_get_saddr(struct sctp_sock *sk, 442 struct sctp_transport *t, 443 struct flowi *fl) 444 { 445 struct flowi6 *fl6 = &fl->u.ip6; 446 union sctp_addr *saddr = &t->saddr; 447 448 pr_debug("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst); 449 450 if (t->dst) { 451 saddr->v6.sin6_family = AF_INET6; 452 saddr->v6.sin6_addr = fl6->saddr; 453 } 454 } 455 456 /* Make a copy of all potential local addresses. */ 457 static void sctp_v6_copy_addrlist(struct list_head *addrlist, 458 struct net_device *dev) 459 { 460 struct inet6_dev *in6_dev; 461 struct inet6_ifaddr *ifp; 462 struct sctp_sockaddr_entry *addr; 463 464 rcu_read_lock(); 465 if ((in6_dev = __in6_dev_get(dev)) == NULL) { 466 rcu_read_unlock(); 467 return; 468 } 469 470 read_lock_bh(&in6_dev->lock); 471 list_for_each_entry(ifp, &in6_dev->addr_list, if_list) { 472 /* Add the address to the local list. */ 473 addr = kzalloc(sizeof(*addr), GFP_ATOMIC); 474 if (addr) { 475 addr->a.v6.sin6_family = AF_INET6; 476 addr->a.v6.sin6_addr = ifp->addr; 477 addr->a.v6.sin6_scope_id = dev->ifindex; 478 addr->valid = 1; 479 INIT_LIST_HEAD(&addr->list); 480 list_add_tail(&addr->list, addrlist); 481 } 482 } 483 484 read_unlock_bh(&in6_dev->lock); 485 rcu_read_unlock(); 486 } 487 488 /* Copy over any ip options */ 489 static void sctp_v6_copy_ip_options(struct sock *sk, struct sock *newsk) 490 { 491 struct ipv6_pinfo *newnp, *np = inet6_sk(sk); 492 struct ipv6_txoptions *opt; 493 494 newnp = inet6_sk(newsk); 495 496 rcu_read_lock(); 497 opt = rcu_dereference(np->opt); 498 if (opt) { 499 opt = ipv6_dup_options(newsk, opt); 500 if (!opt) 501 pr_err("%s: Failed to copy ip options\n", __func__); 502 } 503 RCU_INIT_POINTER(newnp->opt, opt); 504 rcu_read_unlock(); 505 } 506 507 /* Account for the IP options */ 508 static int sctp_v6_ip_options_len(struct sock *sk) 509 { 510 struct ipv6_pinfo *np = inet6_sk(sk); 511 struct ipv6_txoptions *opt; 512 int len = 0; 513 514 rcu_read_lock(); 515 opt = rcu_dereference(np->opt); 516 if (opt) 517 len = opt->opt_flen + opt->opt_nflen; 518 519 rcu_read_unlock(); 520 return len; 521 } 522 523 /* Initialize a sockaddr_storage from in incoming skb. */ 524 static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb, 525 int is_saddr) 526 { 527 /* Always called on head skb, so this is safe */ 528 struct sctphdr *sh = sctp_hdr(skb); 529 struct sockaddr_in6 *sa = &addr->v6; 530 531 addr->v6.sin6_family = AF_INET6; 532 addr->v6.sin6_flowinfo = 0; /* FIXME */ 533 addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif; 534 535 if (is_saddr) { 536 sa->sin6_port = sh->source; 537 sa->sin6_addr = ipv6_hdr(skb)->saddr; 538 } else { 539 sa->sin6_port = sh->dest; 540 sa->sin6_addr = ipv6_hdr(skb)->daddr; 541 } 542 } 543 544 /* Initialize an sctp_addr from a socket. */ 545 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk) 546 { 547 addr->v6.sin6_family = AF_INET6; 548 addr->v6.sin6_port = 0; 549 addr->v6.sin6_addr = sk->sk_v6_rcv_saddr; 550 } 551 552 /* Initialize sk->sk_rcv_saddr from sctp_addr. */ 553 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk) 554 { 555 if (addr->sa.sa_family == AF_INET) { 556 sk->sk_v6_rcv_saddr.s6_addr32[0] = 0; 557 sk->sk_v6_rcv_saddr.s6_addr32[1] = 0; 558 sk->sk_v6_rcv_saddr.s6_addr32[2] = htonl(0x0000ffff); 559 sk->sk_v6_rcv_saddr.s6_addr32[3] = 560 addr->v4.sin_addr.s_addr; 561 } else { 562 sk->sk_v6_rcv_saddr = addr->v6.sin6_addr; 563 } 564 } 565 566 /* Initialize sk->sk_daddr from sctp_addr. */ 567 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk) 568 { 569 if (addr->sa.sa_family == AF_INET) { 570 sk->sk_v6_daddr.s6_addr32[0] = 0; 571 sk->sk_v6_daddr.s6_addr32[1] = 0; 572 sk->sk_v6_daddr.s6_addr32[2] = htonl(0x0000ffff); 573 sk->sk_v6_daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr; 574 } else { 575 sk->sk_v6_daddr = addr->v6.sin6_addr; 576 } 577 } 578 579 /* Initialize a sctp_addr from an address parameter. */ 580 static bool sctp_v6_from_addr_param(union sctp_addr *addr, 581 union sctp_addr_param *param, 582 __be16 port, int iif) 583 { 584 if (ntohs(param->v6.param_hdr.length) < sizeof(struct sctp_ipv6addr_param)) 585 return false; 586 587 addr->v6.sin6_family = AF_INET6; 588 addr->v6.sin6_port = port; 589 addr->v6.sin6_flowinfo = 0; /* BUG */ 590 addr->v6.sin6_addr = param->v6.addr; 591 addr->v6.sin6_scope_id = iif; 592 593 return true; 594 } 595 596 /* Initialize an address parameter from a sctp_addr and return the length 597 * of the address parameter. 598 */ 599 static int sctp_v6_to_addr_param(const union sctp_addr *addr, 600 union sctp_addr_param *param) 601 { 602 int length = sizeof(struct sctp_ipv6addr_param); 603 604 param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS; 605 param->v6.param_hdr.length = htons(length); 606 param->v6.addr = addr->v6.sin6_addr; 607 608 return length; 609 } 610 611 /* Initialize a sctp_addr from struct in6_addr. */ 612 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr, 613 __be16 port) 614 { 615 addr->sa.sa_family = AF_INET6; 616 addr->v6.sin6_port = port; 617 addr->v6.sin6_flowinfo = 0; 618 addr->v6.sin6_addr = *saddr; 619 addr->v6.sin6_scope_id = 0; 620 } 621 622 static int __sctp_v6_cmp_addr(const union sctp_addr *addr1, 623 const union sctp_addr *addr2) 624 { 625 if (addr1->sa.sa_family != addr2->sa.sa_family) { 626 if (addr1->sa.sa_family == AF_INET && 627 addr2->sa.sa_family == AF_INET6 && 628 ipv6_addr_v4mapped(&addr2->v6.sin6_addr) && 629 addr2->v6.sin6_addr.s6_addr32[3] == 630 addr1->v4.sin_addr.s_addr) 631 return 1; 632 633 if (addr2->sa.sa_family == AF_INET && 634 addr1->sa.sa_family == AF_INET6 && 635 ipv6_addr_v4mapped(&addr1->v6.sin6_addr) && 636 addr1->v6.sin6_addr.s6_addr32[3] == 637 addr2->v4.sin_addr.s_addr) 638 return 1; 639 640 return 0; 641 } 642 643 if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr)) 644 return 0; 645 646 /* If this is a linklocal address, compare the scope_id. */ 647 if ((ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) && 648 addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id && 649 addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id) 650 return 0; 651 652 return 1; 653 } 654 655 /* Compare addresses exactly. 656 * v4-mapped-v6 is also in consideration. 657 */ 658 static int sctp_v6_cmp_addr(const union sctp_addr *addr1, 659 const union sctp_addr *addr2) 660 { 661 return __sctp_v6_cmp_addr(addr1, addr2) && 662 addr1->v6.sin6_port == addr2->v6.sin6_port; 663 } 664 665 /* Initialize addr struct to INADDR_ANY. */ 666 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port) 667 { 668 memset(addr, 0x00, sizeof(union sctp_addr)); 669 addr->v6.sin6_family = AF_INET6; 670 addr->v6.sin6_port = port; 671 } 672 673 /* Is this a wildcard address? */ 674 static int sctp_v6_is_any(const union sctp_addr *addr) 675 { 676 return ipv6_addr_any(&addr->v6.sin6_addr); 677 } 678 679 /* Should this be available for binding? */ 680 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp) 681 { 682 const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr; 683 struct sock *sk = &sp->inet.sk; 684 struct net *net = sock_net(sk); 685 struct net_device *dev = NULL; 686 int type, res, bound_dev_if; 687 688 type = ipv6_addr_type(in6); 689 if (IPV6_ADDR_ANY == type) 690 return 1; 691 if (type == IPV6_ADDR_MAPPED) { 692 if (sp && ipv6_only_sock(sctp_opt2sk(sp))) 693 return 0; 694 sctp_v6_map_v4(addr); 695 return sctp_get_af_specific(AF_INET)->available(addr, sp); 696 } 697 if (!(type & IPV6_ADDR_UNICAST)) 698 return 0; 699 700 rcu_read_lock(); 701 bound_dev_if = READ_ONCE(sk->sk_bound_dev_if); 702 if (bound_dev_if) { 703 res = 0; 704 dev = dev_get_by_index_rcu(net, bound_dev_if); 705 if (!dev) 706 goto out; 707 } 708 709 res = ipv6_can_nonlocal_bind(net, &sp->inet) || 710 ipv6_chk_addr(net, in6, dev, 0); 711 712 out: 713 rcu_read_unlock(); 714 return res; 715 } 716 717 /* This function checks if the address is a valid address to be used for 718 * SCTP. 719 * 720 * Output: 721 * Return 0 - If the address is a non-unicast or an illegal address. 722 * Return 1 - If the address is a unicast. 723 */ 724 static int sctp_v6_addr_valid(union sctp_addr *addr, 725 struct sctp_sock *sp, 726 const struct sk_buff *skb) 727 { 728 int ret = ipv6_addr_type(&addr->v6.sin6_addr); 729 730 /* Support v4-mapped-v6 address. */ 731 if (ret == IPV6_ADDR_MAPPED) { 732 /* Note: This routine is used in input, so v4-mapped-v6 733 * are disallowed here when there is no sctp_sock. 734 */ 735 if (sp && ipv6_only_sock(sctp_opt2sk(sp))) 736 return 0; 737 sctp_v6_map_v4(addr); 738 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb); 739 } 740 741 /* Is this a non-unicast address */ 742 if (!(ret & IPV6_ADDR_UNICAST)) 743 return 0; 744 745 return 1; 746 } 747 748 /* What is the scope of 'addr'? */ 749 static enum sctp_scope sctp_v6_scope(union sctp_addr *addr) 750 { 751 enum sctp_scope retval; 752 int v6scope; 753 754 /* The IPv6 scope is really a set of bit fields. 755 * See IFA_* in <net/if_inet6.h>. Map to a generic SCTP scope. 756 */ 757 758 v6scope = ipv6_addr_scope(&addr->v6.sin6_addr); 759 switch (v6scope) { 760 case IFA_HOST: 761 retval = SCTP_SCOPE_LOOPBACK; 762 break; 763 case IFA_LINK: 764 retval = SCTP_SCOPE_LINK; 765 break; 766 case IFA_SITE: 767 retval = SCTP_SCOPE_PRIVATE; 768 break; 769 default: 770 retval = SCTP_SCOPE_GLOBAL; 771 break; 772 } 773 774 return retval; 775 } 776 777 /* Create and initialize a new sk for the socket to be returned by accept(). */ 778 static struct sock *sctp_v6_create_accept_sk(struct sock *sk, 779 struct sctp_association *asoc, 780 bool kern) 781 { 782 struct sock *newsk; 783 struct ipv6_pinfo *newnp, *np = inet6_sk(sk); 784 struct sctp6_sock *newsctp6sk; 785 786 newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot, kern); 787 if (!newsk) 788 goto out; 789 790 sock_init_data(NULL, newsk); 791 792 sctp_copy_sock(newsk, sk, asoc); 793 sock_reset_flag(sk, SOCK_ZAPPED); 794 795 newsctp6sk = (struct sctp6_sock *)newsk; 796 inet_sk(newsk)->pinet6 = &newsctp6sk->inet6; 797 798 sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped; 799 800 newnp = inet6_sk(newsk); 801 802 memcpy(newnp, np, sizeof(struct ipv6_pinfo)); 803 newnp->ipv6_mc_list = NULL; 804 newnp->ipv6_ac_list = NULL; 805 newnp->ipv6_fl_list = NULL; 806 807 sctp_v6_copy_ip_options(sk, newsk); 808 809 /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname() 810 * and getpeername(). 811 */ 812 sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk); 813 814 newsk->sk_v6_rcv_saddr = sk->sk_v6_rcv_saddr; 815 816 if (newsk->sk_prot->init(newsk)) { 817 sk_common_release(newsk); 818 newsk = NULL; 819 } 820 821 out: 822 return newsk; 823 } 824 825 /* Format a sockaddr for return to user space. This makes sure the return is 826 * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option. 827 */ 828 static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr) 829 { 830 if (sp->v4mapped) { 831 if (addr->sa.sa_family == AF_INET) 832 sctp_v4_map_v6(addr); 833 } else { 834 if (addr->sa.sa_family == AF_INET6 && 835 ipv6_addr_v4mapped(&addr->v6.sin6_addr)) 836 sctp_v6_map_v4(addr); 837 } 838 839 if (addr->sa.sa_family == AF_INET) { 840 memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero)); 841 return sizeof(struct sockaddr_in); 842 } 843 return sizeof(struct sockaddr_in6); 844 } 845 846 /* Where did this skb come from? */ 847 static int sctp_v6_skb_iif(const struct sk_buff *skb) 848 { 849 return inet6_iif(skb); 850 } 851 852 static int sctp_v6_skb_sdif(const struct sk_buff *skb) 853 { 854 return inet6_sdif(skb); 855 } 856 857 /* Was this packet marked by Explicit Congestion Notification? */ 858 static int sctp_v6_is_ce(const struct sk_buff *skb) 859 { 860 return *((__u32 *)(ipv6_hdr(skb))) & (__force __u32)htonl(1 << 20); 861 } 862 863 /* Dump the v6 addr to the seq file. */ 864 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr) 865 { 866 seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr); 867 } 868 869 static void sctp_v6_ecn_capable(struct sock *sk) 870 { 871 inet6_sk(sk)->tclass |= INET_ECN_ECT_0; 872 } 873 874 /* Initialize a PF_INET msgname from a ulpevent. */ 875 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event, 876 char *msgname, int *addrlen) 877 { 878 union sctp_addr *addr; 879 struct sctp_association *asoc; 880 union sctp_addr *paddr; 881 882 if (!msgname) 883 return; 884 885 addr = (union sctp_addr *)msgname; 886 asoc = event->asoc; 887 paddr = &asoc->peer.primary_addr; 888 889 if (paddr->sa.sa_family == AF_INET) { 890 addr->v4.sin_family = AF_INET; 891 addr->v4.sin_port = htons(asoc->peer.port); 892 addr->v4.sin_addr = paddr->v4.sin_addr; 893 } else { 894 addr->v6.sin6_family = AF_INET6; 895 addr->v6.sin6_flowinfo = 0; 896 if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) 897 addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id; 898 else 899 addr->v6.sin6_scope_id = 0; 900 addr->v6.sin6_port = htons(asoc->peer.port); 901 addr->v6.sin6_addr = paddr->v6.sin6_addr; 902 } 903 904 *addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr); 905 } 906 907 /* Initialize a msg_name from an inbound skb. */ 908 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname, 909 int *addr_len) 910 { 911 union sctp_addr *addr; 912 struct sctphdr *sh; 913 914 if (!msgname) 915 return; 916 917 addr = (union sctp_addr *)msgname; 918 sh = sctp_hdr(skb); 919 920 if (ip_hdr(skb)->version == 4) { 921 addr->v4.sin_family = AF_INET; 922 addr->v4.sin_port = sh->source; 923 addr->v4.sin_addr.s_addr = ip_hdr(skb)->saddr; 924 } else { 925 addr->v6.sin6_family = AF_INET6; 926 addr->v6.sin6_flowinfo = 0; 927 addr->v6.sin6_port = sh->source; 928 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr; 929 if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) 930 addr->v6.sin6_scope_id = sctp_v6_skb_iif(skb); 931 else 932 addr->v6.sin6_scope_id = 0; 933 } 934 935 *addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr); 936 } 937 938 /* Do we support this AF? */ 939 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp) 940 { 941 switch (family) { 942 case AF_INET6: 943 return 1; 944 /* v4-mapped-v6 addresses */ 945 case AF_INET: 946 if (!ipv6_only_sock(sctp_opt2sk(sp))) 947 return 1; 948 fallthrough; 949 default: 950 return 0; 951 } 952 } 953 954 /* Address matching with wildcards allowed. This extra level 955 * of indirection lets us choose whether a PF_INET6 should 956 * disallow any v4 addresses if we so choose. 957 */ 958 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1, 959 const union sctp_addr *addr2, 960 struct sctp_sock *opt) 961 { 962 struct sock *sk = sctp_opt2sk(opt); 963 struct sctp_af *af1, *af2; 964 965 af1 = sctp_get_af_specific(addr1->sa.sa_family); 966 af2 = sctp_get_af_specific(addr2->sa.sa_family); 967 968 if (!af1 || !af2) 969 return 0; 970 971 /* If the socket is IPv6 only, v4 addrs will not match */ 972 if (ipv6_only_sock(sk) && af1 != af2) 973 return 0; 974 975 /* Today, wildcard AF_INET/AF_INET6. */ 976 if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2)) 977 return 1; 978 979 if (addr1->sa.sa_family == AF_INET && addr2->sa.sa_family == AF_INET) 980 return addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr; 981 982 return __sctp_v6_cmp_addr(addr1, addr2); 983 } 984 985 /* Verify that the provided sockaddr looks bindable. Common verification, 986 * has already been taken care of. 987 */ 988 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr) 989 { 990 struct sctp_af *af; 991 992 /* ASSERT: address family has already been verified. */ 993 if (addr->sa.sa_family != AF_INET6) 994 af = sctp_get_af_specific(addr->sa.sa_family); 995 else { 996 int type = ipv6_addr_type(&addr->v6.sin6_addr); 997 struct net_device *dev; 998 999 if (type & IPV6_ADDR_LINKLOCAL) { 1000 struct net *net; 1001 if (!addr->v6.sin6_scope_id) 1002 return 0; 1003 net = sock_net(&opt->inet.sk); 1004 rcu_read_lock(); 1005 dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id); 1006 if (!dev || !(ipv6_can_nonlocal_bind(net, &opt->inet) || 1007 ipv6_chk_addr(net, &addr->v6.sin6_addr, 1008 dev, 0))) { 1009 rcu_read_unlock(); 1010 return 0; 1011 } 1012 rcu_read_unlock(); 1013 } 1014 1015 af = opt->pf->af; 1016 } 1017 return af->available(addr, opt); 1018 } 1019 1020 /* Verify that the provided sockaddr looks sendable. Common verification, 1021 * has already been taken care of. 1022 */ 1023 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr) 1024 { 1025 struct sctp_af *af = NULL; 1026 1027 /* ASSERT: address family has already been verified. */ 1028 if (addr->sa.sa_family != AF_INET6) 1029 af = sctp_get_af_specific(addr->sa.sa_family); 1030 else { 1031 int type = ipv6_addr_type(&addr->v6.sin6_addr); 1032 struct net_device *dev; 1033 1034 if (type & IPV6_ADDR_LINKLOCAL) { 1035 if (!addr->v6.sin6_scope_id) 1036 return 0; 1037 rcu_read_lock(); 1038 dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk), 1039 addr->v6.sin6_scope_id); 1040 rcu_read_unlock(); 1041 if (!dev) 1042 return 0; 1043 } 1044 af = opt->pf->af; 1045 } 1046 1047 return af != NULL; 1048 } 1049 1050 /* Fill in Supported Address Type information for INIT and INIT-ACK 1051 * chunks. Note: In the future, we may want to look at sock options 1052 * to determine whether a PF_INET6 socket really wants to have IPV4 1053 * addresses. 1054 * Returns number of addresses supported. 1055 */ 1056 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt, 1057 __be16 *types) 1058 { 1059 types[0] = SCTP_PARAM_IPV6_ADDRESS; 1060 if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) { 1061 types[1] = SCTP_PARAM_IPV4_ADDRESS; 1062 return 2; 1063 } 1064 return 1; 1065 } 1066 1067 /* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */ 1068 static int sctp_getname(struct socket *sock, struct sockaddr *uaddr, 1069 int peer) 1070 { 1071 int rc; 1072 1073 rc = inet6_getname(sock, uaddr, peer); 1074 1075 if (rc < 0) 1076 return rc; 1077 1078 rc = sctp_v6_addr_to_user(sctp_sk(sock->sk), 1079 (union sctp_addr *)uaddr); 1080 1081 return rc; 1082 } 1083 1084 static const struct proto_ops inet6_seqpacket_ops = { 1085 .family = PF_INET6, 1086 .owner = THIS_MODULE, 1087 .release = inet6_release, 1088 .bind = inet6_bind, 1089 .connect = sctp_inet_connect, 1090 .socketpair = sock_no_socketpair, 1091 .accept = inet_accept, 1092 .getname = sctp_getname, 1093 .poll = sctp_poll, 1094 .ioctl = inet6_ioctl, 1095 .gettstamp = sock_gettstamp, 1096 .listen = sctp_inet_listen, 1097 .shutdown = inet_shutdown, 1098 .setsockopt = sock_common_setsockopt, 1099 .getsockopt = sock_common_getsockopt, 1100 .sendmsg = inet_sendmsg, 1101 .recvmsg = inet_recvmsg, 1102 .mmap = sock_no_mmap, 1103 #ifdef CONFIG_COMPAT 1104 .compat_ioctl = inet6_compat_ioctl, 1105 #endif 1106 }; 1107 1108 static struct inet_protosw sctpv6_seqpacket_protosw = { 1109 .type = SOCK_SEQPACKET, 1110 .protocol = IPPROTO_SCTP, 1111 .prot = &sctpv6_prot, 1112 .ops = &inet6_seqpacket_ops, 1113 .flags = SCTP_PROTOSW_FLAG 1114 }; 1115 static struct inet_protosw sctpv6_stream_protosw = { 1116 .type = SOCK_STREAM, 1117 .protocol = IPPROTO_SCTP, 1118 .prot = &sctpv6_prot, 1119 .ops = &inet6_seqpacket_ops, 1120 .flags = SCTP_PROTOSW_FLAG, 1121 }; 1122 1123 static int sctp6_rcv(struct sk_buff *skb) 1124 { 1125 SCTP_INPUT_CB(skb)->encap_port = 0; 1126 return sctp_rcv(skb) ? -1 : 0; 1127 } 1128 1129 static const struct inet6_protocol sctpv6_protocol = { 1130 .handler = sctp6_rcv, 1131 .err_handler = sctp_v6_err, 1132 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL, 1133 }; 1134 1135 static struct sctp_af sctp_af_inet6 = { 1136 .sa_family = AF_INET6, 1137 .sctp_xmit = sctp_v6_xmit, 1138 .setsockopt = ipv6_setsockopt, 1139 .getsockopt = ipv6_getsockopt, 1140 .get_dst = sctp_v6_get_dst, 1141 .get_saddr = sctp_v6_get_saddr, 1142 .copy_addrlist = sctp_v6_copy_addrlist, 1143 .from_skb = sctp_v6_from_skb, 1144 .from_sk = sctp_v6_from_sk, 1145 .from_addr_param = sctp_v6_from_addr_param, 1146 .to_addr_param = sctp_v6_to_addr_param, 1147 .cmp_addr = sctp_v6_cmp_addr, 1148 .scope = sctp_v6_scope, 1149 .addr_valid = sctp_v6_addr_valid, 1150 .inaddr_any = sctp_v6_inaddr_any, 1151 .is_any = sctp_v6_is_any, 1152 .available = sctp_v6_available, 1153 .skb_iif = sctp_v6_skb_iif, 1154 .skb_sdif = sctp_v6_skb_sdif, 1155 .is_ce = sctp_v6_is_ce, 1156 .seq_dump_addr = sctp_v6_seq_dump_addr, 1157 .ecn_capable = sctp_v6_ecn_capable, 1158 .net_header_len = sizeof(struct ipv6hdr), 1159 .sockaddr_len = sizeof(struct sockaddr_in6), 1160 .ip_options_len = sctp_v6_ip_options_len, 1161 }; 1162 1163 static struct sctp_pf sctp_pf_inet6 = { 1164 .event_msgname = sctp_inet6_event_msgname, 1165 .skb_msgname = sctp_inet6_skb_msgname, 1166 .af_supported = sctp_inet6_af_supported, 1167 .cmp_addr = sctp_inet6_cmp_addr, 1168 .bind_verify = sctp_inet6_bind_verify, 1169 .send_verify = sctp_inet6_send_verify, 1170 .supported_addrs = sctp_inet6_supported_addrs, 1171 .create_accept_sk = sctp_v6_create_accept_sk, 1172 .addr_to_user = sctp_v6_addr_to_user, 1173 .to_sk_saddr = sctp_v6_to_sk_saddr, 1174 .to_sk_daddr = sctp_v6_to_sk_daddr, 1175 .copy_ip_options = sctp_v6_copy_ip_options, 1176 .af = &sctp_af_inet6, 1177 }; 1178 1179 /* Initialize IPv6 support and register with socket layer. */ 1180 void sctp_v6_pf_init(void) 1181 { 1182 /* Register the SCTP specific PF_INET6 functions. */ 1183 sctp_register_pf(&sctp_pf_inet6, PF_INET6); 1184 1185 /* Register the SCTP specific AF_INET6 functions. */ 1186 sctp_register_af(&sctp_af_inet6); 1187 } 1188 1189 void sctp_v6_pf_exit(void) 1190 { 1191 list_del(&sctp_af_inet6.list); 1192 } 1193 1194 /* Initialize IPv6 support and register with socket layer. */ 1195 int sctp_v6_protosw_init(void) 1196 { 1197 int rc; 1198 1199 rc = proto_register(&sctpv6_prot, 1); 1200 if (rc) 1201 return rc; 1202 1203 /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */ 1204 inet6_register_protosw(&sctpv6_seqpacket_protosw); 1205 inet6_register_protosw(&sctpv6_stream_protosw); 1206 1207 return 0; 1208 } 1209 1210 void sctp_v6_protosw_exit(void) 1211 { 1212 inet6_unregister_protosw(&sctpv6_seqpacket_protosw); 1213 inet6_unregister_protosw(&sctpv6_stream_protosw); 1214 proto_unregister(&sctpv6_prot); 1215 } 1216 1217 1218 /* Register with inet6 layer. */ 1219 int sctp_v6_add_protocol(void) 1220 { 1221 /* Register notifier for inet6 address additions/deletions. */ 1222 register_inet6addr_notifier(&sctp_inet6addr_notifier); 1223 1224 if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0) 1225 return -EAGAIN; 1226 1227 return 0; 1228 } 1229 1230 /* Unregister with inet6 layer. */ 1231 void sctp_v6_del_protocol(void) 1232 { 1233 inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP); 1234 unregister_inet6addr_notifier(&sctp_inet6addr_notifier); 1235 } 1236