1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* SCTP kernel implementation 3 * (C) Copyright IBM Corp. 2002, 2004 4 * Copyright (c) 2001 Nokia, Inc. 5 * Copyright (c) 2001 La Monte H.P. Yarroll 6 * Copyright (c) 2002-2003 Intel Corp. 7 * 8 * This file is part of the SCTP kernel implementation 9 * 10 * SCTP over IPv6. 11 * 12 * Please send any bug reports or fixes you make to the 13 * email address(es): 14 * lksctp developers <linux-sctp@vger.kernel.org> 15 * 16 * Written or modified by: 17 * Le Yanqun <yanqun.le@nokia.com> 18 * Hui Huang <hui.huang@nokia.com> 19 * La Monte H.P. Yarroll <piggy@acm.org> 20 * Sridhar Samudrala <sri@us.ibm.com> 21 * Jon Grimm <jgrimm@us.ibm.com> 22 * Ardelle Fan <ardelle.fan@intel.com> 23 * 24 * Based on: 25 * linux/net/ipv6/tcp_ipv6.c 26 */ 27 28 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 29 30 #include <linux/module.h> 31 #include <linux/errno.h> 32 #include <linux/types.h> 33 #include <linux/socket.h> 34 #include <linux/sockios.h> 35 #include <linux/net.h> 36 #include <linux/in.h> 37 #include <linux/in6.h> 38 #include <linux/netdevice.h> 39 #include <linux/init.h> 40 #include <linux/ipsec.h> 41 #include <linux/slab.h> 42 43 #include <linux/ipv6.h> 44 #include <linux/icmpv6.h> 45 #include <linux/random.h> 46 #include <linux/seq_file.h> 47 48 #include <net/protocol.h> 49 #include <net/ndisc.h> 50 #include <net/ip.h> 51 #include <net/ipv6.h> 52 #include <net/transp_v6.h> 53 #include <net/addrconf.h> 54 #include <net/ip6_route.h> 55 #include <net/inet_common.h> 56 #include <net/inet_ecn.h> 57 #include <net/sctp/sctp.h> 58 #include <net/udp_tunnel.h> 59 60 #include <linux/uaccess.h> 61 62 static inline int sctp_v6_addr_match_len(union sctp_addr *s1, 63 union sctp_addr *s2); 64 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr, 65 __be16 port); 66 static int sctp_v6_cmp_addr(const union sctp_addr *addr1, 67 const union sctp_addr *addr2); 68 69 /* Event handler for inet6 address addition/deletion events. 70 * The sctp_local_addr_list needs to be protocted by a spin lock since 71 * multiple notifiers (say IPv4 and IPv6) may be running at the same 72 * time and thus corrupt the list. 73 * The reader side is protected with RCU. 74 */ 75 static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev, 76 void *ptr) 77 { 78 struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr; 79 struct sctp_sockaddr_entry *addr = NULL; 80 struct sctp_sockaddr_entry *temp; 81 struct net *net = dev_net(ifa->idev->dev); 82 int found = 0; 83 84 switch (ev) { 85 case NETDEV_UP: 86 addr = kzalloc(sizeof(*addr), GFP_ATOMIC); 87 if (addr) { 88 addr->a.v6.sin6_family = AF_INET6; 89 addr->a.v6.sin6_addr = ifa->addr; 90 addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex; 91 addr->valid = 1; 92 spin_lock_bh(&net->sctp.local_addr_lock); 93 list_add_tail_rcu(&addr->list, &net->sctp.local_addr_list); 94 sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_NEW); 95 spin_unlock_bh(&net->sctp.local_addr_lock); 96 } 97 break; 98 case NETDEV_DOWN: 99 spin_lock_bh(&net->sctp.local_addr_lock); 100 list_for_each_entry_safe(addr, temp, 101 &net->sctp.local_addr_list, list) { 102 if (addr->a.sa.sa_family == AF_INET6 && 103 ipv6_addr_equal(&addr->a.v6.sin6_addr, 104 &ifa->addr)) { 105 sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL); 106 found = 1; 107 addr->valid = 0; 108 list_del_rcu(&addr->list); 109 break; 110 } 111 } 112 spin_unlock_bh(&net->sctp.local_addr_lock); 113 if (found) 114 kfree_rcu(addr, rcu); 115 break; 116 } 117 118 return NOTIFY_DONE; 119 } 120 121 static struct notifier_block sctp_inet6addr_notifier = { 122 .notifier_call = sctp_inet6addr_event, 123 }; 124 125 /* ICMP error handler. */ 126 static int sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 127 u8 type, u8 code, int offset, __be32 info) 128 { 129 struct inet6_dev *idev; 130 struct sock *sk; 131 struct sctp_association *asoc; 132 struct sctp_transport *transport; 133 struct ipv6_pinfo *np; 134 __u16 saveip, savesctp; 135 int err, ret = 0; 136 struct net *net = dev_net(skb->dev); 137 138 idev = in6_dev_get(skb->dev); 139 140 /* Fix up skb to look at the embedded net header. */ 141 saveip = skb->network_header; 142 savesctp = skb->transport_header; 143 skb_reset_network_header(skb); 144 skb_set_transport_header(skb, offset); 145 sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &transport); 146 /* Put back, the original pointers. */ 147 skb->network_header = saveip; 148 skb->transport_header = savesctp; 149 if (!sk) { 150 __ICMP6_INC_STATS(net, idev, ICMP6_MIB_INERRORS); 151 ret = -ENOENT; 152 goto out; 153 } 154 155 /* Warning: The sock lock is held. Remember to call 156 * sctp_err_finish! 157 */ 158 159 switch (type) { 160 case ICMPV6_PKT_TOOBIG: 161 if (ip6_sk_accept_pmtu(sk)) 162 sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info)); 163 goto out_unlock; 164 case ICMPV6_PARAMPROB: 165 if (ICMPV6_UNK_NEXTHDR == code) { 166 sctp_icmp_proto_unreachable(sk, asoc, transport); 167 goto out_unlock; 168 } 169 break; 170 case NDISC_REDIRECT: 171 sctp_icmp_redirect(sk, transport, skb); 172 goto out_unlock; 173 default: 174 break; 175 } 176 177 np = inet6_sk(sk); 178 icmpv6_err_convert(type, code, &err); 179 if (!sock_owned_by_user(sk) && np->recverr) { 180 sk->sk_err = err; 181 sk->sk_error_report(sk); 182 } else { /* Only an error on timeout */ 183 sk->sk_err_soft = err; 184 } 185 186 out_unlock: 187 sctp_err_finish(sk, transport); 188 out: 189 if (likely(idev != NULL)) 190 in6_dev_put(idev); 191 192 return ret; 193 } 194 195 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *t) 196 { 197 struct dst_entry *dst = dst_clone(t->dst); 198 struct flowi6 *fl6 = &t->fl.u.ip6; 199 struct sock *sk = skb->sk; 200 struct ipv6_pinfo *np = inet6_sk(sk); 201 __u8 tclass = np->tclass; 202 __be32 label; 203 204 pr_debug("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n", __func__, skb, 205 skb->len, &fl6->saddr, &fl6->daddr); 206 207 if (t->dscp & SCTP_DSCP_SET_MASK) 208 tclass = t->dscp & SCTP_DSCP_VAL_MASK; 209 210 if (INET_ECN_is_capable(tclass)) 211 IP6_ECN_flow_xmit(sk, fl6->flowlabel); 212 213 if (!(t->param_flags & SPP_PMTUD_ENABLE)) 214 skb->ignore_df = 1; 215 216 SCTP_INC_STATS(sock_net(sk), SCTP_MIB_OUTSCTPPACKS); 217 218 if (!t->encap_port || !sctp_sk(sk)->udp_port) { 219 int res; 220 221 skb_dst_set(skb, dst); 222 rcu_read_lock(); 223 res = ip6_xmit(sk, skb, fl6, sk->sk_mark, 224 rcu_dereference(np->opt), 225 tclass, sk->sk_priority); 226 rcu_read_unlock(); 227 return res; 228 } 229 230 if (skb_is_gso(skb)) 231 skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL_CSUM; 232 233 skb->encapsulation = 1; 234 skb_reset_inner_mac_header(skb); 235 skb_reset_inner_transport_header(skb); 236 skb_set_inner_ipproto(skb, IPPROTO_SCTP); 237 label = ip6_make_flowlabel(sock_net(sk), skb, fl6->flowlabel, true, fl6); 238 239 return udp_tunnel6_xmit_skb(dst, sk, skb, NULL, &fl6->saddr, 240 &fl6->daddr, tclass, ip6_dst_hoplimit(dst), 241 label, sctp_sk(sk)->udp_port, t->encap_port, false); 242 } 243 244 /* Returns the dst cache entry for the given source and destination ip 245 * addresses. 246 */ 247 static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr, 248 struct flowi *fl, struct sock *sk) 249 { 250 struct sctp_association *asoc = t->asoc; 251 struct dst_entry *dst = NULL; 252 struct flowi _fl; 253 struct flowi6 *fl6 = &_fl.u.ip6; 254 struct sctp_bind_addr *bp; 255 struct ipv6_pinfo *np = inet6_sk(sk); 256 struct sctp_sockaddr_entry *laddr; 257 union sctp_addr *daddr = &t->ipaddr; 258 union sctp_addr dst_saddr; 259 struct in6_addr *final_p, final; 260 enum sctp_scope scope; 261 __u8 matchlen = 0; 262 263 memset(&_fl, 0, sizeof(_fl)); 264 fl6->daddr = daddr->v6.sin6_addr; 265 fl6->fl6_dport = daddr->v6.sin6_port; 266 fl6->flowi6_proto = IPPROTO_SCTP; 267 if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) 268 fl6->flowi6_oif = daddr->v6.sin6_scope_id; 269 else if (asoc) 270 fl6->flowi6_oif = asoc->base.sk->sk_bound_dev_if; 271 if (t->flowlabel & SCTP_FLOWLABEL_SET_MASK) 272 fl6->flowlabel = htonl(t->flowlabel & SCTP_FLOWLABEL_VAL_MASK); 273 274 if (np->sndflow && (fl6->flowlabel & IPV6_FLOWLABEL_MASK)) { 275 struct ip6_flowlabel *flowlabel; 276 277 flowlabel = fl6_sock_lookup(sk, fl6->flowlabel); 278 if (IS_ERR(flowlabel)) 279 goto out; 280 fl6_sock_release(flowlabel); 281 } 282 283 pr_debug("%s: dst=%pI6 ", __func__, &fl6->daddr); 284 285 if (asoc) 286 fl6->fl6_sport = htons(asoc->base.bind_addr.port); 287 288 if (saddr) { 289 fl6->saddr = saddr->v6.sin6_addr; 290 if (!fl6->fl6_sport) 291 fl6->fl6_sport = saddr->v6.sin6_port; 292 293 pr_debug("src=%pI6 - ", &fl6->saddr); 294 } 295 296 rcu_read_lock(); 297 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final); 298 rcu_read_unlock(); 299 300 dst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p); 301 if (!asoc || saddr) { 302 t->dst = dst; 303 memcpy(fl, &_fl, sizeof(_fl)); 304 goto out; 305 } 306 307 bp = &asoc->base.bind_addr; 308 scope = sctp_scope(daddr); 309 /* ip6_dst_lookup has filled in the fl6->saddr for us. Check 310 * to see if we can use it. 311 */ 312 if (!IS_ERR(dst)) { 313 /* Walk through the bind address list and look for a bind 314 * address that matches the source address of the returned dst. 315 */ 316 sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port)); 317 rcu_read_lock(); 318 list_for_each_entry_rcu(laddr, &bp->address_list, list) { 319 if (!laddr->valid || laddr->state == SCTP_ADDR_DEL || 320 (laddr->state != SCTP_ADDR_SRC && 321 !asoc->src_out_of_asoc_ok)) 322 continue; 323 324 /* Do not compare against v4 addrs */ 325 if ((laddr->a.sa.sa_family == AF_INET6) && 326 (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) { 327 rcu_read_unlock(); 328 t->dst = dst; 329 memcpy(fl, &_fl, sizeof(_fl)); 330 goto out; 331 } 332 } 333 rcu_read_unlock(); 334 /* None of the bound addresses match the source address of the 335 * dst. So release it. 336 */ 337 dst_release(dst); 338 dst = NULL; 339 } 340 341 /* Walk through the bind address list and try to get the 342 * best source address for a given destination. 343 */ 344 rcu_read_lock(); 345 list_for_each_entry_rcu(laddr, &bp->address_list, list) { 346 struct dst_entry *bdst; 347 __u8 bmatchlen; 348 349 if (!laddr->valid || 350 laddr->state != SCTP_ADDR_SRC || 351 laddr->a.sa.sa_family != AF_INET6 || 352 scope > sctp_scope(&laddr->a)) 353 continue; 354 355 fl6->saddr = laddr->a.v6.sin6_addr; 356 fl6->fl6_sport = laddr->a.v6.sin6_port; 357 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final); 358 bdst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p); 359 360 if (IS_ERR(bdst)) 361 continue; 362 363 if (ipv6_chk_addr(dev_net(bdst->dev), 364 &laddr->a.v6.sin6_addr, bdst->dev, 1)) { 365 if (!IS_ERR_OR_NULL(dst)) 366 dst_release(dst); 367 dst = bdst; 368 t->dst = dst; 369 memcpy(fl, &_fl, sizeof(_fl)); 370 break; 371 } 372 373 bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a); 374 if (matchlen > bmatchlen) { 375 dst_release(bdst); 376 continue; 377 } 378 379 if (!IS_ERR_OR_NULL(dst)) 380 dst_release(dst); 381 dst = bdst; 382 matchlen = bmatchlen; 383 t->dst = dst; 384 memcpy(fl, &_fl, sizeof(_fl)); 385 } 386 rcu_read_unlock(); 387 388 out: 389 if (!IS_ERR_OR_NULL(dst)) { 390 struct rt6_info *rt; 391 392 rt = (struct rt6_info *)dst; 393 t->dst_cookie = rt6_get_cookie(rt); 394 pr_debug("rt6_dst:%pI6/%d rt6_src:%pI6\n", 395 &rt->rt6i_dst.addr, rt->rt6i_dst.plen, 396 &fl->u.ip6.saddr); 397 } else { 398 t->dst = NULL; 399 pr_debug("no route\n"); 400 } 401 } 402 403 /* Returns the number of consecutive initial bits that match in the 2 ipv6 404 * addresses. 405 */ 406 static inline int sctp_v6_addr_match_len(union sctp_addr *s1, 407 union sctp_addr *s2) 408 { 409 return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr); 410 } 411 412 /* Fills in the source address(saddr) based on the destination address(daddr) 413 * and asoc's bind address list. 414 */ 415 static void sctp_v6_get_saddr(struct sctp_sock *sk, 416 struct sctp_transport *t, 417 struct flowi *fl) 418 { 419 struct flowi6 *fl6 = &fl->u.ip6; 420 union sctp_addr *saddr = &t->saddr; 421 422 pr_debug("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst); 423 424 if (t->dst) { 425 saddr->v6.sin6_family = AF_INET6; 426 saddr->v6.sin6_addr = fl6->saddr; 427 } 428 } 429 430 /* Make a copy of all potential local addresses. */ 431 static void sctp_v6_copy_addrlist(struct list_head *addrlist, 432 struct net_device *dev) 433 { 434 struct inet6_dev *in6_dev; 435 struct inet6_ifaddr *ifp; 436 struct sctp_sockaddr_entry *addr; 437 438 rcu_read_lock(); 439 if ((in6_dev = __in6_dev_get(dev)) == NULL) { 440 rcu_read_unlock(); 441 return; 442 } 443 444 read_lock_bh(&in6_dev->lock); 445 list_for_each_entry(ifp, &in6_dev->addr_list, if_list) { 446 /* Add the address to the local list. */ 447 addr = kzalloc(sizeof(*addr), GFP_ATOMIC); 448 if (addr) { 449 addr->a.v6.sin6_family = AF_INET6; 450 addr->a.v6.sin6_addr = ifp->addr; 451 addr->a.v6.sin6_scope_id = dev->ifindex; 452 addr->valid = 1; 453 INIT_LIST_HEAD(&addr->list); 454 list_add_tail(&addr->list, addrlist); 455 } 456 } 457 458 read_unlock_bh(&in6_dev->lock); 459 rcu_read_unlock(); 460 } 461 462 /* Copy over any ip options */ 463 static void sctp_v6_copy_ip_options(struct sock *sk, struct sock *newsk) 464 { 465 struct ipv6_pinfo *newnp, *np = inet6_sk(sk); 466 struct ipv6_txoptions *opt; 467 468 newnp = inet6_sk(newsk); 469 470 rcu_read_lock(); 471 opt = rcu_dereference(np->opt); 472 if (opt) { 473 opt = ipv6_dup_options(newsk, opt); 474 if (!opt) 475 pr_err("%s: Failed to copy ip options\n", __func__); 476 } 477 RCU_INIT_POINTER(newnp->opt, opt); 478 rcu_read_unlock(); 479 } 480 481 /* Account for the IP options */ 482 static int sctp_v6_ip_options_len(struct sock *sk) 483 { 484 struct ipv6_pinfo *np = inet6_sk(sk); 485 struct ipv6_txoptions *opt; 486 int len = 0; 487 488 rcu_read_lock(); 489 opt = rcu_dereference(np->opt); 490 if (opt) 491 len = opt->opt_flen + opt->opt_nflen; 492 493 rcu_read_unlock(); 494 return len; 495 } 496 497 /* Initialize a sockaddr_storage from in incoming skb. */ 498 static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb, 499 int is_saddr) 500 { 501 /* Always called on head skb, so this is safe */ 502 struct sctphdr *sh = sctp_hdr(skb); 503 struct sockaddr_in6 *sa = &addr->v6; 504 505 addr->v6.sin6_family = AF_INET6; 506 addr->v6.sin6_flowinfo = 0; /* FIXME */ 507 addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif; 508 509 if (is_saddr) { 510 sa->sin6_port = sh->source; 511 sa->sin6_addr = ipv6_hdr(skb)->saddr; 512 } else { 513 sa->sin6_port = sh->dest; 514 sa->sin6_addr = ipv6_hdr(skb)->daddr; 515 } 516 } 517 518 /* Initialize an sctp_addr from a socket. */ 519 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk) 520 { 521 addr->v6.sin6_family = AF_INET6; 522 addr->v6.sin6_port = 0; 523 addr->v6.sin6_addr = sk->sk_v6_rcv_saddr; 524 } 525 526 /* Initialize sk->sk_rcv_saddr from sctp_addr. */ 527 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk) 528 { 529 if (addr->sa.sa_family == AF_INET) { 530 sk->sk_v6_rcv_saddr.s6_addr32[0] = 0; 531 sk->sk_v6_rcv_saddr.s6_addr32[1] = 0; 532 sk->sk_v6_rcv_saddr.s6_addr32[2] = htonl(0x0000ffff); 533 sk->sk_v6_rcv_saddr.s6_addr32[3] = 534 addr->v4.sin_addr.s_addr; 535 } else { 536 sk->sk_v6_rcv_saddr = addr->v6.sin6_addr; 537 } 538 } 539 540 /* Initialize sk->sk_daddr from sctp_addr. */ 541 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk) 542 { 543 if (addr->sa.sa_family == AF_INET) { 544 sk->sk_v6_daddr.s6_addr32[0] = 0; 545 sk->sk_v6_daddr.s6_addr32[1] = 0; 546 sk->sk_v6_daddr.s6_addr32[2] = htonl(0x0000ffff); 547 sk->sk_v6_daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr; 548 } else { 549 sk->sk_v6_daddr = addr->v6.sin6_addr; 550 } 551 } 552 553 /* Initialize a sctp_addr from an address parameter. */ 554 static void sctp_v6_from_addr_param(union sctp_addr *addr, 555 union sctp_addr_param *param, 556 __be16 port, int iif) 557 { 558 addr->v6.sin6_family = AF_INET6; 559 addr->v6.sin6_port = port; 560 addr->v6.sin6_flowinfo = 0; /* BUG */ 561 addr->v6.sin6_addr = param->v6.addr; 562 addr->v6.sin6_scope_id = iif; 563 } 564 565 /* Initialize an address parameter from a sctp_addr and return the length 566 * of the address parameter. 567 */ 568 static int sctp_v6_to_addr_param(const union sctp_addr *addr, 569 union sctp_addr_param *param) 570 { 571 int length = sizeof(struct sctp_ipv6addr_param); 572 573 param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS; 574 param->v6.param_hdr.length = htons(length); 575 param->v6.addr = addr->v6.sin6_addr; 576 577 return length; 578 } 579 580 /* Initialize a sctp_addr from struct in6_addr. */ 581 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr, 582 __be16 port) 583 { 584 addr->sa.sa_family = AF_INET6; 585 addr->v6.sin6_port = port; 586 addr->v6.sin6_flowinfo = 0; 587 addr->v6.sin6_addr = *saddr; 588 addr->v6.sin6_scope_id = 0; 589 } 590 591 static int __sctp_v6_cmp_addr(const union sctp_addr *addr1, 592 const union sctp_addr *addr2) 593 { 594 if (addr1->sa.sa_family != addr2->sa.sa_family) { 595 if (addr1->sa.sa_family == AF_INET && 596 addr2->sa.sa_family == AF_INET6 && 597 ipv6_addr_v4mapped(&addr2->v6.sin6_addr) && 598 addr2->v6.sin6_addr.s6_addr32[3] == 599 addr1->v4.sin_addr.s_addr) 600 return 1; 601 602 if (addr2->sa.sa_family == AF_INET && 603 addr1->sa.sa_family == AF_INET6 && 604 ipv6_addr_v4mapped(&addr1->v6.sin6_addr) && 605 addr1->v6.sin6_addr.s6_addr32[3] == 606 addr2->v4.sin_addr.s_addr) 607 return 1; 608 609 return 0; 610 } 611 612 if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr)) 613 return 0; 614 615 /* If this is a linklocal address, compare the scope_id. */ 616 if ((ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) && 617 addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id && 618 addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id) 619 return 0; 620 621 return 1; 622 } 623 624 /* Compare addresses exactly. 625 * v4-mapped-v6 is also in consideration. 626 */ 627 static int sctp_v6_cmp_addr(const union sctp_addr *addr1, 628 const union sctp_addr *addr2) 629 { 630 return __sctp_v6_cmp_addr(addr1, addr2) && 631 addr1->v6.sin6_port == addr2->v6.sin6_port; 632 } 633 634 /* Initialize addr struct to INADDR_ANY. */ 635 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port) 636 { 637 memset(addr, 0x00, sizeof(union sctp_addr)); 638 addr->v6.sin6_family = AF_INET6; 639 addr->v6.sin6_port = port; 640 } 641 642 /* Is this a wildcard address? */ 643 static int sctp_v6_is_any(const union sctp_addr *addr) 644 { 645 return ipv6_addr_any(&addr->v6.sin6_addr); 646 } 647 648 /* Should this be available for binding? */ 649 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp) 650 { 651 int type; 652 struct net *net = sock_net(&sp->inet.sk); 653 const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr; 654 655 type = ipv6_addr_type(in6); 656 if (IPV6_ADDR_ANY == type) 657 return 1; 658 if (type == IPV6_ADDR_MAPPED) { 659 if (sp && ipv6_only_sock(sctp_opt2sk(sp))) 660 return 0; 661 sctp_v6_map_v4(addr); 662 return sctp_get_af_specific(AF_INET)->available(addr, sp); 663 } 664 if (!(type & IPV6_ADDR_UNICAST)) 665 return 0; 666 667 return sp->inet.freebind || net->ipv6.sysctl.ip_nonlocal_bind || 668 ipv6_chk_addr(net, in6, NULL, 0); 669 } 670 671 /* This function checks if the address is a valid address to be used for 672 * SCTP. 673 * 674 * Output: 675 * Return 0 - If the address is a non-unicast or an illegal address. 676 * Return 1 - If the address is a unicast. 677 */ 678 static int sctp_v6_addr_valid(union sctp_addr *addr, 679 struct sctp_sock *sp, 680 const struct sk_buff *skb) 681 { 682 int ret = ipv6_addr_type(&addr->v6.sin6_addr); 683 684 /* Support v4-mapped-v6 address. */ 685 if (ret == IPV6_ADDR_MAPPED) { 686 /* Note: This routine is used in input, so v4-mapped-v6 687 * are disallowed here when there is no sctp_sock. 688 */ 689 if (sp && ipv6_only_sock(sctp_opt2sk(sp))) 690 return 0; 691 sctp_v6_map_v4(addr); 692 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb); 693 } 694 695 /* Is this a non-unicast address */ 696 if (!(ret & IPV6_ADDR_UNICAST)) 697 return 0; 698 699 return 1; 700 } 701 702 /* What is the scope of 'addr'? */ 703 static enum sctp_scope sctp_v6_scope(union sctp_addr *addr) 704 { 705 enum sctp_scope retval; 706 int v6scope; 707 708 /* The IPv6 scope is really a set of bit fields. 709 * See IFA_* in <net/if_inet6.h>. Map to a generic SCTP scope. 710 */ 711 712 v6scope = ipv6_addr_scope(&addr->v6.sin6_addr); 713 switch (v6scope) { 714 case IFA_HOST: 715 retval = SCTP_SCOPE_LOOPBACK; 716 break; 717 case IFA_LINK: 718 retval = SCTP_SCOPE_LINK; 719 break; 720 case IFA_SITE: 721 retval = SCTP_SCOPE_PRIVATE; 722 break; 723 default: 724 retval = SCTP_SCOPE_GLOBAL; 725 break; 726 } 727 728 return retval; 729 } 730 731 /* Create and initialize a new sk for the socket to be returned by accept(). */ 732 static struct sock *sctp_v6_create_accept_sk(struct sock *sk, 733 struct sctp_association *asoc, 734 bool kern) 735 { 736 struct sock *newsk; 737 struct ipv6_pinfo *newnp, *np = inet6_sk(sk); 738 struct sctp6_sock *newsctp6sk; 739 740 newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot, kern); 741 if (!newsk) 742 goto out; 743 744 sock_init_data(NULL, newsk); 745 746 sctp_copy_sock(newsk, sk, asoc); 747 sock_reset_flag(sk, SOCK_ZAPPED); 748 749 newsctp6sk = (struct sctp6_sock *)newsk; 750 inet_sk(newsk)->pinet6 = &newsctp6sk->inet6; 751 752 sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped; 753 754 newnp = inet6_sk(newsk); 755 756 memcpy(newnp, np, sizeof(struct ipv6_pinfo)); 757 newnp->ipv6_mc_list = NULL; 758 newnp->ipv6_ac_list = NULL; 759 newnp->ipv6_fl_list = NULL; 760 761 sctp_v6_copy_ip_options(sk, newsk); 762 763 /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname() 764 * and getpeername(). 765 */ 766 sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk); 767 768 newsk->sk_v6_rcv_saddr = sk->sk_v6_rcv_saddr; 769 770 sk_refcnt_debug_inc(newsk); 771 772 if (newsk->sk_prot->init(newsk)) { 773 sk_common_release(newsk); 774 newsk = NULL; 775 } 776 777 out: 778 return newsk; 779 } 780 781 /* Format a sockaddr for return to user space. This makes sure the return is 782 * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option. 783 */ 784 static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr) 785 { 786 if (sp->v4mapped) { 787 if (addr->sa.sa_family == AF_INET) 788 sctp_v4_map_v6(addr); 789 } else { 790 if (addr->sa.sa_family == AF_INET6 && 791 ipv6_addr_v4mapped(&addr->v6.sin6_addr)) 792 sctp_v6_map_v4(addr); 793 } 794 795 if (addr->sa.sa_family == AF_INET) { 796 memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero)); 797 return sizeof(struct sockaddr_in); 798 } 799 return sizeof(struct sockaddr_in6); 800 } 801 802 /* Where did this skb come from? */ 803 static int sctp_v6_skb_iif(const struct sk_buff *skb) 804 { 805 return IP6CB(skb)->iif; 806 } 807 808 /* Was this packet marked by Explicit Congestion Notification? */ 809 static int sctp_v6_is_ce(const struct sk_buff *skb) 810 { 811 return *((__u32 *)(ipv6_hdr(skb))) & (__force __u32)htonl(1 << 20); 812 } 813 814 /* Dump the v6 addr to the seq file. */ 815 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr) 816 { 817 seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr); 818 } 819 820 static void sctp_v6_ecn_capable(struct sock *sk) 821 { 822 inet6_sk(sk)->tclass |= INET_ECN_ECT_0; 823 } 824 825 /* Initialize a PF_INET msgname from a ulpevent. */ 826 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event, 827 char *msgname, int *addrlen) 828 { 829 union sctp_addr *addr; 830 struct sctp_association *asoc; 831 union sctp_addr *paddr; 832 833 if (!msgname) 834 return; 835 836 addr = (union sctp_addr *)msgname; 837 asoc = event->asoc; 838 paddr = &asoc->peer.primary_addr; 839 840 if (paddr->sa.sa_family == AF_INET) { 841 addr->v4.sin_family = AF_INET; 842 addr->v4.sin_port = htons(asoc->peer.port); 843 addr->v4.sin_addr = paddr->v4.sin_addr; 844 } else { 845 addr->v6.sin6_family = AF_INET6; 846 addr->v6.sin6_flowinfo = 0; 847 if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) 848 addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id; 849 else 850 addr->v6.sin6_scope_id = 0; 851 addr->v6.sin6_port = htons(asoc->peer.port); 852 addr->v6.sin6_addr = paddr->v6.sin6_addr; 853 } 854 855 *addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr); 856 } 857 858 /* Initialize a msg_name from an inbound skb. */ 859 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname, 860 int *addr_len) 861 { 862 union sctp_addr *addr; 863 struct sctphdr *sh; 864 865 if (!msgname) 866 return; 867 868 addr = (union sctp_addr *)msgname; 869 sh = sctp_hdr(skb); 870 871 if (ip_hdr(skb)->version == 4) { 872 addr->v4.sin_family = AF_INET; 873 addr->v4.sin_port = sh->source; 874 addr->v4.sin_addr.s_addr = ip_hdr(skb)->saddr; 875 } else { 876 addr->v6.sin6_family = AF_INET6; 877 addr->v6.sin6_flowinfo = 0; 878 addr->v6.sin6_port = sh->source; 879 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr; 880 if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) 881 addr->v6.sin6_scope_id = sctp_v6_skb_iif(skb); 882 else 883 addr->v6.sin6_scope_id = 0; 884 } 885 886 *addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr); 887 } 888 889 /* Do we support this AF? */ 890 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp) 891 { 892 switch (family) { 893 case AF_INET6: 894 return 1; 895 /* v4-mapped-v6 addresses */ 896 case AF_INET: 897 if (!__ipv6_only_sock(sctp_opt2sk(sp))) 898 return 1; 899 fallthrough; 900 default: 901 return 0; 902 } 903 } 904 905 /* Address matching with wildcards allowed. This extra level 906 * of indirection lets us choose whether a PF_INET6 should 907 * disallow any v4 addresses if we so choose. 908 */ 909 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1, 910 const union sctp_addr *addr2, 911 struct sctp_sock *opt) 912 { 913 struct sock *sk = sctp_opt2sk(opt); 914 struct sctp_af *af1, *af2; 915 916 af1 = sctp_get_af_specific(addr1->sa.sa_family); 917 af2 = sctp_get_af_specific(addr2->sa.sa_family); 918 919 if (!af1 || !af2) 920 return 0; 921 922 /* If the socket is IPv6 only, v4 addrs will not match */ 923 if (__ipv6_only_sock(sk) && af1 != af2) 924 return 0; 925 926 /* Today, wildcard AF_INET/AF_INET6. */ 927 if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2)) 928 return 1; 929 930 if (addr1->sa.sa_family == AF_INET && addr2->sa.sa_family == AF_INET) 931 return addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr; 932 933 return __sctp_v6_cmp_addr(addr1, addr2); 934 } 935 936 /* Verify that the provided sockaddr looks bindable. Common verification, 937 * has already been taken care of. 938 */ 939 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr) 940 { 941 struct sctp_af *af; 942 943 /* ASSERT: address family has already been verified. */ 944 if (addr->sa.sa_family != AF_INET6) 945 af = sctp_get_af_specific(addr->sa.sa_family); 946 else { 947 int type = ipv6_addr_type(&addr->v6.sin6_addr); 948 struct net_device *dev; 949 950 if (type & IPV6_ADDR_LINKLOCAL) { 951 struct net *net; 952 if (!addr->v6.sin6_scope_id) 953 return 0; 954 net = sock_net(&opt->inet.sk); 955 rcu_read_lock(); 956 dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id); 957 if (!dev || !(opt->inet.freebind || 958 net->ipv6.sysctl.ip_nonlocal_bind || 959 ipv6_chk_addr(net, &addr->v6.sin6_addr, 960 dev, 0))) { 961 rcu_read_unlock(); 962 return 0; 963 } 964 rcu_read_unlock(); 965 } 966 967 af = opt->pf->af; 968 } 969 return af->available(addr, opt); 970 } 971 972 /* Verify that the provided sockaddr looks sendable. Common verification, 973 * has already been taken care of. 974 */ 975 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr) 976 { 977 struct sctp_af *af = NULL; 978 979 /* ASSERT: address family has already been verified. */ 980 if (addr->sa.sa_family != AF_INET6) 981 af = sctp_get_af_specific(addr->sa.sa_family); 982 else { 983 int type = ipv6_addr_type(&addr->v6.sin6_addr); 984 struct net_device *dev; 985 986 if (type & IPV6_ADDR_LINKLOCAL) { 987 if (!addr->v6.sin6_scope_id) 988 return 0; 989 rcu_read_lock(); 990 dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk), 991 addr->v6.sin6_scope_id); 992 rcu_read_unlock(); 993 if (!dev) 994 return 0; 995 } 996 af = opt->pf->af; 997 } 998 999 return af != NULL; 1000 } 1001 1002 /* Fill in Supported Address Type information for INIT and INIT-ACK 1003 * chunks. Note: In the future, we may want to look at sock options 1004 * to determine whether a PF_INET6 socket really wants to have IPV4 1005 * addresses. 1006 * Returns number of addresses supported. 1007 */ 1008 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt, 1009 __be16 *types) 1010 { 1011 types[0] = SCTP_PARAM_IPV6_ADDRESS; 1012 if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) { 1013 types[1] = SCTP_PARAM_IPV4_ADDRESS; 1014 return 2; 1015 } 1016 return 1; 1017 } 1018 1019 /* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */ 1020 static int sctp_getname(struct socket *sock, struct sockaddr *uaddr, 1021 int peer) 1022 { 1023 int rc; 1024 1025 rc = inet6_getname(sock, uaddr, peer); 1026 1027 if (rc < 0) 1028 return rc; 1029 1030 rc = sctp_v6_addr_to_user(sctp_sk(sock->sk), 1031 (union sctp_addr *)uaddr); 1032 1033 return rc; 1034 } 1035 1036 static const struct proto_ops inet6_seqpacket_ops = { 1037 .family = PF_INET6, 1038 .owner = THIS_MODULE, 1039 .release = inet6_release, 1040 .bind = inet6_bind, 1041 .connect = sctp_inet_connect, 1042 .socketpair = sock_no_socketpair, 1043 .accept = inet_accept, 1044 .getname = sctp_getname, 1045 .poll = sctp_poll, 1046 .ioctl = inet6_ioctl, 1047 .gettstamp = sock_gettstamp, 1048 .listen = sctp_inet_listen, 1049 .shutdown = inet_shutdown, 1050 .setsockopt = sock_common_setsockopt, 1051 .getsockopt = sock_common_getsockopt, 1052 .sendmsg = inet_sendmsg, 1053 .recvmsg = inet_recvmsg, 1054 .mmap = sock_no_mmap, 1055 #ifdef CONFIG_COMPAT 1056 .compat_ioctl = inet6_compat_ioctl, 1057 #endif 1058 }; 1059 1060 static struct inet_protosw sctpv6_seqpacket_protosw = { 1061 .type = SOCK_SEQPACKET, 1062 .protocol = IPPROTO_SCTP, 1063 .prot = &sctpv6_prot, 1064 .ops = &inet6_seqpacket_ops, 1065 .flags = SCTP_PROTOSW_FLAG 1066 }; 1067 static struct inet_protosw sctpv6_stream_protosw = { 1068 .type = SOCK_STREAM, 1069 .protocol = IPPROTO_SCTP, 1070 .prot = &sctpv6_prot, 1071 .ops = &inet6_seqpacket_ops, 1072 .flags = SCTP_PROTOSW_FLAG, 1073 }; 1074 1075 static int sctp6_rcv(struct sk_buff *skb) 1076 { 1077 SCTP_INPUT_CB(skb)->encap_port = 0; 1078 return sctp_rcv(skb) ? -1 : 0; 1079 } 1080 1081 static const struct inet6_protocol sctpv6_protocol = { 1082 .handler = sctp6_rcv, 1083 .err_handler = sctp_v6_err, 1084 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL, 1085 }; 1086 1087 static struct sctp_af sctp_af_inet6 = { 1088 .sa_family = AF_INET6, 1089 .sctp_xmit = sctp_v6_xmit, 1090 .setsockopt = ipv6_setsockopt, 1091 .getsockopt = ipv6_getsockopt, 1092 .get_dst = sctp_v6_get_dst, 1093 .get_saddr = sctp_v6_get_saddr, 1094 .copy_addrlist = sctp_v6_copy_addrlist, 1095 .from_skb = sctp_v6_from_skb, 1096 .from_sk = sctp_v6_from_sk, 1097 .from_addr_param = sctp_v6_from_addr_param, 1098 .to_addr_param = sctp_v6_to_addr_param, 1099 .cmp_addr = sctp_v6_cmp_addr, 1100 .scope = sctp_v6_scope, 1101 .addr_valid = sctp_v6_addr_valid, 1102 .inaddr_any = sctp_v6_inaddr_any, 1103 .is_any = sctp_v6_is_any, 1104 .available = sctp_v6_available, 1105 .skb_iif = sctp_v6_skb_iif, 1106 .is_ce = sctp_v6_is_ce, 1107 .seq_dump_addr = sctp_v6_seq_dump_addr, 1108 .ecn_capable = sctp_v6_ecn_capable, 1109 .net_header_len = sizeof(struct ipv6hdr), 1110 .sockaddr_len = sizeof(struct sockaddr_in6), 1111 .ip_options_len = sctp_v6_ip_options_len, 1112 }; 1113 1114 static struct sctp_pf sctp_pf_inet6 = { 1115 .event_msgname = sctp_inet6_event_msgname, 1116 .skb_msgname = sctp_inet6_skb_msgname, 1117 .af_supported = sctp_inet6_af_supported, 1118 .cmp_addr = sctp_inet6_cmp_addr, 1119 .bind_verify = sctp_inet6_bind_verify, 1120 .send_verify = sctp_inet6_send_verify, 1121 .supported_addrs = sctp_inet6_supported_addrs, 1122 .create_accept_sk = sctp_v6_create_accept_sk, 1123 .addr_to_user = sctp_v6_addr_to_user, 1124 .to_sk_saddr = sctp_v6_to_sk_saddr, 1125 .to_sk_daddr = sctp_v6_to_sk_daddr, 1126 .copy_ip_options = sctp_v6_copy_ip_options, 1127 .af = &sctp_af_inet6, 1128 }; 1129 1130 /* Initialize IPv6 support and register with socket layer. */ 1131 void sctp_v6_pf_init(void) 1132 { 1133 /* Register the SCTP specific PF_INET6 functions. */ 1134 sctp_register_pf(&sctp_pf_inet6, PF_INET6); 1135 1136 /* Register the SCTP specific AF_INET6 functions. */ 1137 sctp_register_af(&sctp_af_inet6); 1138 } 1139 1140 void sctp_v6_pf_exit(void) 1141 { 1142 list_del(&sctp_af_inet6.list); 1143 } 1144 1145 /* Initialize IPv6 support and register with socket layer. */ 1146 int sctp_v6_protosw_init(void) 1147 { 1148 int rc; 1149 1150 rc = proto_register(&sctpv6_prot, 1); 1151 if (rc) 1152 return rc; 1153 1154 /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */ 1155 inet6_register_protosw(&sctpv6_seqpacket_protosw); 1156 inet6_register_protosw(&sctpv6_stream_protosw); 1157 1158 return 0; 1159 } 1160 1161 void sctp_v6_protosw_exit(void) 1162 { 1163 inet6_unregister_protosw(&sctpv6_seqpacket_protosw); 1164 inet6_unregister_protosw(&sctpv6_stream_protosw); 1165 proto_unregister(&sctpv6_prot); 1166 } 1167 1168 1169 /* Register with inet6 layer. */ 1170 int sctp_v6_add_protocol(void) 1171 { 1172 /* Register notifier for inet6 address additions/deletions. */ 1173 register_inet6addr_notifier(&sctp_inet6addr_notifier); 1174 1175 if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0) 1176 return -EAGAIN; 1177 1178 return 0; 1179 } 1180 1181 /* Unregister with inet6 layer. */ 1182 void sctp_v6_del_protocol(void) 1183 { 1184 inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP); 1185 unregister_inet6addr_notifier(&sctp_inet6addr_notifier); 1186 } 1187