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 sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL); 107 found = 1; 108 addr->valid = 0; 109 list_del_rcu(&addr->list); 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 struct ipv6_pinfo *np; 132 int err = 0; 133 134 switch (type) { 135 case ICMPV6_PKT_TOOBIG: 136 if (ip6_sk_accept_pmtu(sk)) 137 sctp_icmp_frag_needed(sk, asoc, t, info); 138 return; 139 case ICMPV6_PARAMPROB: 140 if (ICMPV6_UNK_NEXTHDR == code) { 141 sctp_icmp_proto_unreachable(sk, asoc, t); 142 return; 143 } 144 break; 145 case NDISC_REDIRECT: 146 sctp_icmp_redirect(sk, t, skb); 147 return; 148 default: 149 break; 150 } 151 152 np = inet6_sk(sk); 153 icmpv6_err_convert(type, code, &err); 154 if (!sock_owned_by_user(sk) && np->recverr) { 155 sk->sk_err = err; 156 sk_error_report(sk); 157 } else { 158 WRITE_ONCE(sk->sk_err_soft, err); 159 } 160 } 161 162 /* ICMP error handler. */ 163 static int sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, 164 u8 type, u8 code, int offset, __be32 info) 165 { 166 struct net *net = dev_net(skb->dev); 167 struct sctp_transport *transport; 168 struct sctp_association *asoc; 169 __u16 saveip, savesctp; 170 struct sock *sk; 171 172 /* Fix up skb to look at the embedded net header. */ 173 saveip = skb->network_header; 174 savesctp = skb->transport_header; 175 skb_reset_network_header(skb); 176 skb_set_transport_header(skb, offset); 177 sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &transport); 178 /* Put back, the original pointers. */ 179 skb->network_header = saveip; 180 skb->transport_header = savesctp; 181 if (!sk) { 182 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS); 183 return -ENOENT; 184 } 185 186 sctp_v6_err_handle(transport, skb, type, code, ntohl(info)); 187 sctp_err_finish(sk, transport); 188 189 return 0; 190 } 191 192 int sctp_udp_v6_err(struct sock *sk, struct sk_buff *skb) 193 { 194 struct net *net = dev_net(skb->dev); 195 struct sctp_association *asoc; 196 struct sctp_transport *t; 197 struct icmp6hdr *hdr; 198 __u32 info = 0; 199 200 skb->transport_header += sizeof(struct udphdr); 201 sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &t); 202 if (!sk) { 203 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS); 204 return -ENOENT; 205 } 206 207 skb->transport_header -= sizeof(struct udphdr); 208 hdr = (struct icmp6hdr *)(skb_network_header(skb) - sizeof(struct icmp6hdr)); 209 if (hdr->icmp6_type == NDISC_REDIRECT) { 210 /* can't be handled without outer ip6hdr known, leave it to udpv6_err */ 211 sctp_err_finish(sk, t); 212 return 0; 213 } 214 if (hdr->icmp6_type == ICMPV6_PKT_TOOBIG) 215 info = ntohl(hdr->icmp6_mtu); 216 sctp_v6_err_handle(t, skb, hdr->icmp6_type, hdr->icmp6_code, info); 217 218 sctp_err_finish(sk, t); 219 return 1; 220 } 221 222 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *t) 223 { 224 struct dst_entry *dst = dst_clone(t->dst); 225 struct flowi6 *fl6 = &t->fl.u.ip6; 226 struct sock *sk = skb->sk; 227 struct ipv6_pinfo *np = inet6_sk(sk); 228 __u8 tclass = np->tclass; 229 __be32 label; 230 231 pr_debug("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n", __func__, skb, 232 skb->len, &fl6->saddr, &fl6->daddr); 233 234 if (t->dscp & SCTP_DSCP_SET_MASK) 235 tclass = t->dscp & SCTP_DSCP_VAL_MASK; 236 237 if (INET_ECN_is_capable(tclass)) 238 IP6_ECN_flow_xmit(sk, fl6->flowlabel); 239 240 if (!(t->param_flags & SPP_PMTUD_ENABLE)) 241 skb->ignore_df = 1; 242 243 SCTP_INC_STATS(sock_net(sk), SCTP_MIB_OUTSCTPPACKS); 244 245 if (!t->encap_port || !sctp_sk(sk)->udp_port) { 246 int res; 247 248 skb_dst_set(skb, dst); 249 rcu_read_lock(); 250 res = ip6_xmit(sk, skb, fl6, sk->sk_mark, 251 rcu_dereference(np->opt), 252 tclass, sk->sk_priority); 253 rcu_read_unlock(); 254 return res; 255 } 256 257 if (skb_is_gso(skb)) 258 skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL_CSUM; 259 260 skb->encapsulation = 1; 261 skb_reset_inner_mac_header(skb); 262 skb_reset_inner_transport_header(skb); 263 skb_set_inner_ipproto(skb, IPPROTO_SCTP); 264 label = ip6_make_flowlabel(sock_net(sk), skb, fl6->flowlabel, true, fl6); 265 266 return udp_tunnel6_xmit_skb(dst, sk, skb, NULL, &fl6->saddr, 267 &fl6->daddr, tclass, ip6_dst_hoplimit(dst), 268 label, sctp_sk(sk)->udp_port, t->encap_port, false); 269 } 270 271 /* Returns the dst cache entry for the given source and destination ip 272 * addresses. 273 */ 274 static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr, 275 struct flowi *fl, struct sock *sk) 276 { 277 struct sctp_association *asoc = t->asoc; 278 struct dst_entry *dst = NULL; 279 struct flowi _fl; 280 struct flowi6 *fl6 = &_fl.u.ip6; 281 struct sctp_bind_addr *bp; 282 struct ipv6_pinfo *np = inet6_sk(sk); 283 struct sctp_sockaddr_entry *laddr; 284 union sctp_addr *daddr = &t->ipaddr; 285 union sctp_addr dst_saddr; 286 struct in6_addr *final_p, final; 287 enum sctp_scope scope; 288 __u8 matchlen = 0; 289 290 memset(&_fl, 0, sizeof(_fl)); 291 fl6->daddr = daddr->v6.sin6_addr; 292 fl6->fl6_dport = daddr->v6.sin6_port; 293 fl6->flowi6_proto = IPPROTO_SCTP; 294 if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) 295 fl6->flowi6_oif = daddr->v6.sin6_scope_id; 296 else if (asoc) 297 fl6->flowi6_oif = asoc->base.sk->sk_bound_dev_if; 298 if (t->flowlabel & SCTP_FLOWLABEL_SET_MASK) 299 fl6->flowlabel = htonl(t->flowlabel & SCTP_FLOWLABEL_VAL_MASK); 300 301 if (np->sndflow && (fl6->flowlabel & IPV6_FLOWLABEL_MASK)) { 302 struct ip6_flowlabel *flowlabel; 303 304 flowlabel = fl6_sock_lookup(sk, fl6->flowlabel); 305 if (IS_ERR(flowlabel)) 306 goto out; 307 fl6_sock_release(flowlabel); 308 } 309 310 pr_debug("%s: dst=%pI6 ", __func__, &fl6->daddr); 311 312 if (asoc) 313 fl6->fl6_sport = htons(asoc->base.bind_addr.port); 314 315 if (saddr) { 316 fl6->saddr = saddr->v6.sin6_addr; 317 if (!fl6->fl6_sport) 318 fl6->fl6_sport = saddr->v6.sin6_port; 319 320 pr_debug("src=%pI6 - ", &fl6->saddr); 321 } 322 323 rcu_read_lock(); 324 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final); 325 rcu_read_unlock(); 326 327 dst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p); 328 if (!asoc || saddr) { 329 t->dst = dst; 330 memcpy(fl, &_fl, sizeof(_fl)); 331 goto out; 332 } 333 334 bp = &asoc->base.bind_addr; 335 scope = sctp_scope(daddr); 336 /* ip6_dst_lookup has filled in the fl6->saddr for us. Check 337 * to see if we can use it. 338 */ 339 if (!IS_ERR(dst)) { 340 /* Walk through the bind address list and look for a bind 341 * address that matches the source address of the returned dst. 342 */ 343 sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port)); 344 rcu_read_lock(); 345 list_for_each_entry_rcu(laddr, &bp->address_list, list) { 346 if (!laddr->valid || laddr->state == SCTP_ADDR_DEL || 347 (laddr->state != SCTP_ADDR_SRC && 348 !asoc->src_out_of_asoc_ok)) 349 continue; 350 351 /* Do not compare against v4 addrs */ 352 if ((laddr->a.sa.sa_family == AF_INET6) && 353 (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) { 354 rcu_read_unlock(); 355 t->dst = dst; 356 memcpy(fl, &_fl, sizeof(_fl)); 357 goto out; 358 } 359 } 360 rcu_read_unlock(); 361 /* None of the bound addresses match the source address of the 362 * dst. So release it. 363 */ 364 dst_release(dst); 365 dst = NULL; 366 } 367 368 /* Walk through the bind address list and try to get the 369 * best source address for a given destination. 370 */ 371 rcu_read_lock(); 372 list_for_each_entry_rcu(laddr, &bp->address_list, list) { 373 struct dst_entry *bdst; 374 __u8 bmatchlen; 375 376 if (!laddr->valid || 377 laddr->state != SCTP_ADDR_SRC || 378 laddr->a.sa.sa_family != AF_INET6 || 379 scope > sctp_scope(&laddr->a)) 380 continue; 381 382 fl6->saddr = laddr->a.v6.sin6_addr; 383 fl6->fl6_sport = laddr->a.v6.sin6_port; 384 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final); 385 bdst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p); 386 387 if (IS_ERR(bdst)) 388 continue; 389 390 if (ipv6_chk_addr(dev_net(bdst->dev), 391 &laddr->a.v6.sin6_addr, bdst->dev, 1)) { 392 if (!IS_ERR_OR_NULL(dst)) 393 dst_release(dst); 394 dst = bdst; 395 t->dst = dst; 396 memcpy(fl, &_fl, sizeof(_fl)); 397 break; 398 } 399 400 bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a); 401 if (matchlen > bmatchlen) { 402 dst_release(bdst); 403 continue; 404 } 405 406 if (!IS_ERR_OR_NULL(dst)) 407 dst_release(dst); 408 dst = bdst; 409 matchlen = bmatchlen; 410 t->dst = dst; 411 memcpy(fl, &_fl, sizeof(_fl)); 412 } 413 rcu_read_unlock(); 414 415 out: 416 if (!IS_ERR_OR_NULL(dst)) { 417 struct rt6_info *rt; 418 419 rt = (struct rt6_info *)dst; 420 t->dst_cookie = rt6_get_cookie(rt); 421 pr_debug("rt6_dst:%pI6/%d rt6_src:%pI6\n", 422 &rt->rt6i_dst.addr, rt->rt6i_dst.plen, 423 &fl->u.ip6.saddr); 424 } else { 425 t->dst = NULL; 426 pr_debug("no route\n"); 427 } 428 } 429 430 /* Returns the number of consecutive initial bits that match in the 2 ipv6 431 * addresses. 432 */ 433 static inline int sctp_v6_addr_match_len(union sctp_addr *s1, 434 union sctp_addr *s2) 435 { 436 return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr); 437 } 438 439 /* Fills in the source address(saddr) based on the destination address(daddr) 440 * and asoc's bind address list. 441 */ 442 static void sctp_v6_get_saddr(struct sctp_sock *sk, 443 struct sctp_transport *t, 444 struct flowi *fl) 445 { 446 struct flowi6 *fl6 = &fl->u.ip6; 447 union sctp_addr *saddr = &t->saddr; 448 449 pr_debug("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst); 450 451 if (t->dst) { 452 saddr->v6.sin6_family = AF_INET6; 453 saddr->v6.sin6_addr = fl6->saddr; 454 } 455 } 456 457 /* Make a copy of all potential local addresses. */ 458 static void sctp_v6_copy_addrlist(struct list_head *addrlist, 459 struct net_device *dev) 460 { 461 struct inet6_dev *in6_dev; 462 struct inet6_ifaddr *ifp; 463 struct sctp_sockaddr_entry *addr; 464 465 rcu_read_lock(); 466 if ((in6_dev = __in6_dev_get(dev)) == NULL) { 467 rcu_read_unlock(); 468 return; 469 } 470 471 read_lock_bh(&in6_dev->lock); 472 list_for_each_entry(ifp, &in6_dev->addr_list, if_list) { 473 /* Add the address to the local list. */ 474 addr = kzalloc(sizeof(*addr), GFP_ATOMIC); 475 if (addr) { 476 addr->a.v6.sin6_family = AF_INET6; 477 addr->a.v6.sin6_addr = ifp->addr; 478 addr->a.v6.sin6_scope_id = dev->ifindex; 479 addr->valid = 1; 480 INIT_LIST_HEAD(&addr->list); 481 list_add_tail(&addr->list, addrlist); 482 } 483 } 484 485 read_unlock_bh(&in6_dev->lock); 486 rcu_read_unlock(); 487 } 488 489 /* Copy over any ip options */ 490 static void sctp_v6_copy_ip_options(struct sock *sk, struct sock *newsk) 491 { 492 struct ipv6_pinfo *newnp, *np = inet6_sk(sk); 493 struct ipv6_txoptions *opt; 494 495 newnp = inet6_sk(newsk); 496 497 rcu_read_lock(); 498 opt = rcu_dereference(np->opt); 499 if (opt) { 500 opt = ipv6_dup_options(newsk, opt); 501 if (!opt) 502 pr_err("%s: Failed to copy ip options\n", __func__); 503 } 504 RCU_INIT_POINTER(newnp->opt, opt); 505 rcu_read_unlock(); 506 } 507 508 /* Account for the IP options */ 509 static int sctp_v6_ip_options_len(struct sock *sk) 510 { 511 struct ipv6_pinfo *np = inet6_sk(sk); 512 struct ipv6_txoptions *opt; 513 int len = 0; 514 515 rcu_read_lock(); 516 opt = rcu_dereference(np->opt); 517 if (opt) 518 len = opt->opt_flen + opt->opt_nflen; 519 520 rcu_read_unlock(); 521 return len; 522 } 523 524 /* Initialize a sockaddr_storage from in incoming skb. */ 525 static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb, 526 int is_saddr) 527 { 528 /* Always called on head skb, so this is safe */ 529 struct sctphdr *sh = sctp_hdr(skb); 530 struct sockaddr_in6 *sa = &addr->v6; 531 532 addr->v6.sin6_family = AF_INET6; 533 addr->v6.sin6_flowinfo = 0; /* FIXME */ 534 addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif; 535 536 if (is_saddr) { 537 sa->sin6_port = sh->source; 538 sa->sin6_addr = ipv6_hdr(skb)->saddr; 539 } else { 540 sa->sin6_port = sh->dest; 541 sa->sin6_addr = ipv6_hdr(skb)->daddr; 542 } 543 } 544 545 /* Initialize an sctp_addr from a socket. */ 546 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk) 547 { 548 addr->v6.sin6_family = AF_INET6; 549 addr->v6.sin6_port = 0; 550 addr->v6.sin6_addr = sk->sk_v6_rcv_saddr; 551 } 552 553 /* Initialize sk->sk_rcv_saddr from sctp_addr. */ 554 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk) 555 { 556 if (addr->sa.sa_family == AF_INET) { 557 sk->sk_v6_rcv_saddr.s6_addr32[0] = 0; 558 sk->sk_v6_rcv_saddr.s6_addr32[1] = 0; 559 sk->sk_v6_rcv_saddr.s6_addr32[2] = htonl(0x0000ffff); 560 sk->sk_v6_rcv_saddr.s6_addr32[3] = 561 addr->v4.sin_addr.s_addr; 562 } else { 563 sk->sk_v6_rcv_saddr = addr->v6.sin6_addr; 564 } 565 } 566 567 /* Initialize sk->sk_daddr from sctp_addr. */ 568 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk) 569 { 570 if (addr->sa.sa_family == AF_INET) { 571 sk->sk_v6_daddr.s6_addr32[0] = 0; 572 sk->sk_v6_daddr.s6_addr32[1] = 0; 573 sk->sk_v6_daddr.s6_addr32[2] = htonl(0x0000ffff); 574 sk->sk_v6_daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr; 575 } else { 576 sk->sk_v6_daddr = addr->v6.sin6_addr; 577 } 578 } 579 580 /* Initialize a sctp_addr from an address parameter. */ 581 static bool sctp_v6_from_addr_param(union sctp_addr *addr, 582 union sctp_addr_param *param, 583 __be16 port, int iif) 584 { 585 if (ntohs(param->v6.param_hdr.length) < sizeof(struct sctp_ipv6addr_param)) 586 return false; 587 588 addr->v6.sin6_family = AF_INET6; 589 addr->v6.sin6_port = port; 590 addr->v6.sin6_flowinfo = 0; /* BUG */ 591 addr->v6.sin6_addr = param->v6.addr; 592 addr->v6.sin6_scope_id = iif; 593 594 return true; 595 } 596 597 /* Initialize an address parameter from a sctp_addr and return the length 598 * of the address parameter. 599 */ 600 static int sctp_v6_to_addr_param(const union sctp_addr *addr, 601 union sctp_addr_param *param) 602 { 603 int length = sizeof(struct sctp_ipv6addr_param); 604 605 param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS; 606 param->v6.param_hdr.length = htons(length); 607 param->v6.addr = addr->v6.sin6_addr; 608 609 return length; 610 } 611 612 /* Initialize a sctp_addr from struct in6_addr. */ 613 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr, 614 __be16 port) 615 { 616 addr->sa.sa_family = AF_INET6; 617 addr->v6.sin6_port = port; 618 addr->v6.sin6_flowinfo = 0; 619 addr->v6.sin6_addr = *saddr; 620 addr->v6.sin6_scope_id = 0; 621 } 622 623 static int __sctp_v6_cmp_addr(const union sctp_addr *addr1, 624 const union sctp_addr *addr2) 625 { 626 if (addr1->sa.sa_family != addr2->sa.sa_family) { 627 if (addr1->sa.sa_family == AF_INET && 628 addr2->sa.sa_family == AF_INET6 && 629 ipv6_addr_v4mapped(&addr2->v6.sin6_addr) && 630 addr2->v6.sin6_addr.s6_addr32[3] == 631 addr1->v4.sin_addr.s_addr) 632 return 1; 633 634 if (addr2->sa.sa_family == AF_INET && 635 addr1->sa.sa_family == AF_INET6 && 636 ipv6_addr_v4mapped(&addr1->v6.sin6_addr) && 637 addr1->v6.sin6_addr.s6_addr32[3] == 638 addr2->v4.sin_addr.s_addr) 639 return 1; 640 641 return 0; 642 } 643 644 if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr)) 645 return 0; 646 647 /* If this is a linklocal address, compare the scope_id. */ 648 if ((ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) && 649 addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id && 650 addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id) 651 return 0; 652 653 return 1; 654 } 655 656 /* Compare addresses exactly. 657 * v4-mapped-v6 is also in consideration. 658 */ 659 static int sctp_v6_cmp_addr(const union sctp_addr *addr1, 660 const union sctp_addr *addr2) 661 { 662 return __sctp_v6_cmp_addr(addr1, addr2) && 663 addr1->v6.sin6_port == addr2->v6.sin6_port; 664 } 665 666 /* Initialize addr struct to INADDR_ANY. */ 667 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port) 668 { 669 memset(addr, 0x00, sizeof(union sctp_addr)); 670 addr->v6.sin6_family = AF_INET6; 671 addr->v6.sin6_port = port; 672 } 673 674 /* Is this a wildcard address? */ 675 static int sctp_v6_is_any(const union sctp_addr *addr) 676 { 677 return ipv6_addr_any(&addr->v6.sin6_addr); 678 } 679 680 /* Should this be available for binding? */ 681 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp) 682 { 683 const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr; 684 struct sock *sk = &sp->inet.sk; 685 struct net *net = sock_net(sk); 686 struct net_device *dev = NULL; 687 int type; 688 689 type = ipv6_addr_type(in6); 690 if (IPV6_ADDR_ANY == type) 691 return 1; 692 if (type == IPV6_ADDR_MAPPED) { 693 if (sp && ipv6_only_sock(sctp_opt2sk(sp))) 694 return 0; 695 sctp_v6_map_v4(addr); 696 return sctp_get_af_specific(AF_INET)->available(addr, sp); 697 } 698 if (!(type & IPV6_ADDR_UNICAST)) 699 return 0; 700 701 if (sk->sk_bound_dev_if) { 702 dev = dev_get_by_index_rcu(net, sk->sk_bound_dev_if); 703 if (!dev) 704 return 0; 705 } 706 707 return ipv6_can_nonlocal_bind(net, &sp->inet) || 708 ipv6_chk_addr(net, in6, dev, 0); 709 } 710 711 /* This function checks if the address is a valid address to be used for 712 * SCTP. 713 * 714 * Output: 715 * Return 0 - If the address is a non-unicast or an illegal address. 716 * Return 1 - If the address is a unicast. 717 */ 718 static int sctp_v6_addr_valid(union sctp_addr *addr, 719 struct sctp_sock *sp, 720 const struct sk_buff *skb) 721 { 722 int ret = ipv6_addr_type(&addr->v6.sin6_addr); 723 724 /* Support v4-mapped-v6 address. */ 725 if (ret == IPV6_ADDR_MAPPED) { 726 /* Note: This routine is used in input, so v4-mapped-v6 727 * are disallowed here when there is no sctp_sock. 728 */ 729 if (sp && ipv6_only_sock(sctp_opt2sk(sp))) 730 return 0; 731 sctp_v6_map_v4(addr); 732 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb); 733 } 734 735 /* Is this a non-unicast address */ 736 if (!(ret & IPV6_ADDR_UNICAST)) 737 return 0; 738 739 return 1; 740 } 741 742 /* What is the scope of 'addr'? */ 743 static enum sctp_scope sctp_v6_scope(union sctp_addr *addr) 744 { 745 enum sctp_scope retval; 746 int v6scope; 747 748 /* The IPv6 scope is really a set of bit fields. 749 * See IFA_* in <net/if_inet6.h>. Map to a generic SCTP scope. 750 */ 751 752 v6scope = ipv6_addr_scope(&addr->v6.sin6_addr); 753 switch (v6scope) { 754 case IFA_HOST: 755 retval = SCTP_SCOPE_LOOPBACK; 756 break; 757 case IFA_LINK: 758 retval = SCTP_SCOPE_LINK; 759 break; 760 case IFA_SITE: 761 retval = SCTP_SCOPE_PRIVATE; 762 break; 763 default: 764 retval = SCTP_SCOPE_GLOBAL; 765 break; 766 } 767 768 return retval; 769 } 770 771 /* Create and initialize a new sk for the socket to be returned by accept(). */ 772 static struct sock *sctp_v6_create_accept_sk(struct sock *sk, 773 struct sctp_association *asoc, 774 bool kern) 775 { 776 struct sock *newsk; 777 struct ipv6_pinfo *newnp, *np = inet6_sk(sk); 778 struct sctp6_sock *newsctp6sk; 779 780 newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot, kern); 781 if (!newsk) 782 goto out; 783 784 sock_init_data(NULL, newsk); 785 786 sctp_copy_sock(newsk, sk, asoc); 787 sock_reset_flag(sk, SOCK_ZAPPED); 788 789 newsctp6sk = (struct sctp6_sock *)newsk; 790 inet_sk(newsk)->pinet6 = &newsctp6sk->inet6; 791 792 sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped; 793 794 newnp = inet6_sk(newsk); 795 796 memcpy(newnp, np, sizeof(struct ipv6_pinfo)); 797 newnp->ipv6_mc_list = NULL; 798 newnp->ipv6_ac_list = NULL; 799 newnp->ipv6_fl_list = NULL; 800 801 sctp_v6_copy_ip_options(sk, newsk); 802 803 /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname() 804 * and getpeername(). 805 */ 806 sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk); 807 808 newsk->sk_v6_rcv_saddr = sk->sk_v6_rcv_saddr; 809 810 if (newsk->sk_prot->init(newsk)) { 811 sk_common_release(newsk); 812 newsk = NULL; 813 } 814 815 out: 816 return newsk; 817 } 818 819 /* Format a sockaddr for return to user space. This makes sure the return is 820 * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option. 821 */ 822 static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr) 823 { 824 if (sp->v4mapped) { 825 if (addr->sa.sa_family == AF_INET) 826 sctp_v4_map_v6(addr); 827 } else { 828 if (addr->sa.sa_family == AF_INET6 && 829 ipv6_addr_v4mapped(&addr->v6.sin6_addr)) 830 sctp_v6_map_v4(addr); 831 } 832 833 if (addr->sa.sa_family == AF_INET) { 834 memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero)); 835 return sizeof(struct sockaddr_in); 836 } 837 return sizeof(struct sockaddr_in6); 838 } 839 840 /* Where did this skb come from? */ 841 static int sctp_v6_skb_iif(const struct sk_buff *skb) 842 { 843 return inet6_iif(skb); 844 } 845 846 static int sctp_v6_skb_sdif(const struct sk_buff *skb) 847 { 848 return inet6_sdif(skb); 849 } 850 851 /* Was this packet marked by Explicit Congestion Notification? */ 852 static int sctp_v6_is_ce(const struct sk_buff *skb) 853 { 854 return *((__u32 *)(ipv6_hdr(skb))) & (__force __u32)htonl(1 << 20); 855 } 856 857 /* Dump the v6 addr to the seq file. */ 858 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr) 859 { 860 seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr); 861 } 862 863 static void sctp_v6_ecn_capable(struct sock *sk) 864 { 865 inet6_sk(sk)->tclass |= INET_ECN_ECT_0; 866 } 867 868 /* Initialize a PF_INET msgname from a ulpevent. */ 869 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event, 870 char *msgname, int *addrlen) 871 { 872 union sctp_addr *addr; 873 struct sctp_association *asoc; 874 union sctp_addr *paddr; 875 876 if (!msgname) 877 return; 878 879 addr = (union sctp_addr *)msgname; 880 asoc = event->asoc; 881 paddr = &asoc->peer.primary_addr; 882 883 if (paddr->sa.sa_family == AF_INET) { 884 addr->v4.sin_family = AF_INET; 885 addr->v4.sin_port = htons(asoc->peer.port); 886 addr->v4.sin_addr = paddr->v4.sin_addr; 887 } else { 888 addr->v6.sin6_family = AF_INET6; 889 addr->v6.sin6_flowinfo = 0; 890 if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) 891 addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id; 892 else 893 addr->v6.sin6_scope_id = 0; 894 addr->v6.sin6_port = htons(asoc->peer.port); 895 addr->v6.sin6_addr = paddr->v6.sin6_addr; 896 } 897 898 *addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr); 899 } 900 901 /* Initialize a msg_name from an inbound skb. */ 902 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname, 903 int *addr_len) 904 { 905 union sctp_addr *addr; 906 struct sctphdr *sh; 907 908 if (!msgname) 909 return; 910 911 addr = (union sctp_addr *)msgname; 912 sh = sctp_hdr(skb); 913 914 if (ip_hdr(skb)->version == 4) { 915 addr->v4.sin_family = AF_INET; 916 addr->v4.sin_port = sh->source; 917 addr->v4.sin_addr.s_addr = ip_hdr(skb)->saddr; 918 } else { 919 addr->v6.sin6_family = AF_INET6; 920 addr->v6.sin6_flowinfo = 0; 921 addr->v6.sin6_port = sh->source; 922 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr; 923 if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) 924 addr->v6.sin6_scope_id = sctp_v6_skb_iif(skb); 925 else 926 addr->v6.sin6_scope_id = 0; 927 } 928 929 *addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr); 930 } 931 932 /* Do we support this AF? */ 933 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp) 934 { 935 switch (family) { 936 case AF_INET6: 937 return 1; 938 /* v4-mapped-v6 addresses */ 939 case AF_INET: 940 if (!ipv6_only_sock(sctp_opt2sk(sp))) 941 return 1; 942 fallthrough; 943 default: 944 return 0; 945 } 946 } 947 948 /* Address matching with wildcards allowed. This extra level 949 * of indirection lets us choose whether a PF_INET6 should 950 * disallow any v4 addresses if we so choose. 951 */ 952 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1, 953 const union sctp_addr *addr2, 954 struct sctp_sock *opt) 955 { 956 struct sock *sk = sctp_opt2sk(opt); 957 struct sctp_af *af1, *af2; 958 959 af1 = sctp_get_af_specific(addr1->sa.sa_family); 960 af2 = sctp_get_af_specific(addr2->sa.sa_family); 961 962 if (!af1 || !af2) 963 return 0; 964 965 /* If the socket is IPv6 only, v4 addrs will not match */ 966 if (ipv6_only_sock(sk) && af1 != af2) 967 return 0; 968 969 /* Today, wildcard AF_INET/AF_INET6. */ 970 if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2)) 971 return 1; 972 973 if (addr1->sa.sa_family == AF_INET && addr2->sa.sa_family == AF_INET) 974 return addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr; 975 976 return __sctp_v6_cmp_addr(addr1, addr2); 977 } 978 979 /* Verify that the provided sockaddr looks bindable. Common verification, 980 * has already been taken care of. 981 */ 982 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr) 983 { 984 struct sctp_af *af; 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 struct net *net; 995 if (!addr->v6.sin6_scope_id) 996 return 0; 997 net = sock_net(&opt->inet.sk); 998 rcu_read_lock(); 999 dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id); 1000 if (!dev || !(ipv6_can_nonlocal_bind(net, &opt->inet) || 1001 ipv6_chk_addr(net, &addr->v6.sin6_addr, 1002 dev, 0))) { 1003 rcu_read_unlock(); 1004 return 0; 1005 } 1006 rcu_read_unlock(); 1007 } 1008 1009 af = opt->pf->af; 1010 } 1011 return af->available(addr, opt); 1012 } 1013 1014 /* Verify that the provided sockaddr looks sendable. Common verification, 1015 * has already been taken care of. 1016 */ 1017 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr) 1018 { 1019 struct sctp_af *af = NULL; 1020 1021 /* ASSERT: address family has already been verified. */ 1022 if (addr->sa.sa_family != AF_INET6) 1023 af = sctp_get_af_specific(addr->sa.sa_family); 1024 else { 1025 int type = ipv6_addr_type(&addr->v6.sin6_addr); 1026 struct net_device *dev; 1027 1028 if (type & IPV6_ADDR_LINKLOCAL) { 1029 if (!addr->v6.sin6_scope_id) 1030 return 0; 1031 rcu_read_lock(); 1032 dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk), 1033 addr->v6.sin6_scope_id); 1034 rcu_read_unlock(); 1035 if (!dev) 1036 return 0; 1037 } 1038 af = opt->pf->af; 1039 } 1040 1041 return af != NULL; 1042 } 1043 1044 /* Fill in Supported Address Type information for INIT and INIT-ACK 1045 * chunks. Note: In the future, we may want to look at sock options 1046 * to determine whether a PF_INET6 socket really wants to have IPV4 1047 * addresses. 1048 * Returns number of addresses supported. 1049 */ 1050 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt, 1051 __be16 *types) 1052 { 1053 types[0] = SCTP_PARAM_IPV6_ADDRESS; 1054 if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) { 1055 types[1] = SCTP_PARAM_IPV4_ADDRESS; 1056 return 2; 1057 } 1058 return 1; 1059 } 1060 1061 /* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */ 1062 static int sctp_getname(struct socket *sock, struct sockaddr *uaddr, 1063 int peer) 1064 { 1065 int rc; 1066 1067 rc = inet6_getname(sock, uaddr, peer); 1068 1069 if (rc < 0) 1070 return rc; 1071 1072 rc = sctp_v6_addr_to_user(sctp_sk(sock->sk), 1073 (union sctp_addr *)uaddr); 1074 1075 return rc; 1076 } 1077 1078 static const struct proto_ops inet6_seqpacket_ops = { 1079 .family = PF_INET6, 1080 .owner = THIS_MODULE, 1081 .release = inet6_release, 1082 .bind = inet6_bind, 1083 .connect = sctp_inet_connect, 1084 .socketpair = sock_no_socketpair, 1085 .accept = inet_accept, 1086 .getname = sctp_getname, 1087 .poll = sctp_poll, 1088 .ioctl = inet6_ioctl, 1089 .gettstamp = sock_gettstamp, 1090 .listen = sctp_inet_listen, 1091 .shutdown = inet_shutdown, 1092 .setsockopt = sock_common_setsockopt, 1093 .getsockopt = sock_common_getsockopt, 1094 .sendmsg = inet_sendmsg, 1095 .recvmsg = inet_recvmsg, 1096 .mmap = sock_no_mmap, 1097 #ifdef CONFIG_COMPAT 1098 .compat_ioctl = inet6_compat_ioctl, 1099 #endif 1100 }; 1101 1102 static struct inet_protosw sctpv6_seqpacket_protosw = { 1103 .type = SOCK_SEQPACKET, 1104 .protocol = IPPROTO_SCTP, 1105 .prot = &sctpv6_prot, 1106 .ops = &inet6_seqpacket_ops, 1107 .flags = SCTP_PROTOSW_FLAG 1108 }; 1109 static struct inet_protosw sctpv6_stream_protosw = { 1110 .type = SOCK_STREAM, 1111 .protocol = IPPROTO_SCTP, 1112 .prot = &sctpv6_prot, 1113 .ops = &inet6_seqpacket_ops, 1114 .flags = SCTP_PROTOSW_FLAG, 1115 }; 1116 1117 static int sctp6_rcv(struct sk_buff *skb) 1118 { 1119 SCTP_INPUT_CB(skb)->encap_port = 0; 1120 return sctp_rcv(skb) ? -1 : 0; 1121 } 1122 1123 static const struct inet6_protocol sctpv6_protocol = { 1124 .handler = sctp6_rcv, 1125 .err_handler = sctp_v6_err, 1126 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL, 1127 }; 1128 1129 static struct sctp_af sctp_af_inet6 = { 1130 .sa_family = AF_INET6, 1131 .sctp_xmit = sctp_v6_xmit, 1132 .setsockopt = ipv6_setsockopt, 1133 .getsockopt = ipv6_getsockopt, 1134 .get_dst = sctp_v6_get_dst, 1135 .get_saddr = sctp_v6_get_saddr, 1136 .copy_addrlist = sctp_v6_copy_addrlist, 1137 .from_skb = sctp_v6_from_skb, 1138 .from_sk = sctp_v6_from_sk, 1139 .from_addr_param = sctp_v6_from_addr_param, 1140 .to_addr_param = sctp_v6_to_addr_param, 1141 .cmp_addr = sctp_v6_cmp_addr, 1142 .scope = sctp_v6_scope, 1143 .addr_valid = sctp_v6_addr_valid, 1144 .inaddr_any = sctp_v6_inaddr_any, 1145 .is_any = sctp_v6_is_any, 1146 .available = sctp_v6_available, 1147 .skb_iif = sctp_v6_skb_iif, 1148 .skb_sdif = sctp_v6_skb_sdif, 1149 .is_ce = sctp_v6_is_ce, 1150 .seq_dump_addr = sctp_v6_seq_dump_addr, 1151 .ecn_capable = sctp_v6_ecn_capable, 1152 .net_header_len = sizeof(struct ipv6hdr), 1153 .sockaddr_len = sizeof(struct sockaddr_in6), 1154 .ip_options_len = sctp_v6_ip_options_len, 1155 }; 1156 1157 static struct sctp_pf sctp_pf_inet6 = { 1158 .event_msgname = sctp_inet6_event_msgname, 1159 .skb_msgname = sctp_inet6_skb_msgname, 1160 .af_supported = sctp_inet6_af_supported, 1161 .cmp_addr = sctp_inet6_cmp_addr, 1162 .bind_verify = sctp_inet6_bind_verify, 1163 .send_verify = sctp_inet6_send_verify, 1164 .supported_addrs = sctp_inet6_supported_addrs, 1165 .create_accept_sk = sctp_v6_create_accept_sk, 1166 .addr_to_user = sctp_v6_addr_to_user, 1167 .to_sk_saddr = sctp_v6_to_sk_saddr, 1168 .to_sk_daddr = sctp_v6_to_sk_daddr, 1169 .copy_ip_options = sctp_v6_copy_ip_options, 1170 .af = &sctp_af_inet6, 1171 }; 1172 1173 /* Initialize IPv6 support and register with socket layer. */ 1174 void sctp_v6_pf_init(void) 1175 { 1176 /* Register the SCTP specific PF_INET6 functions. */ 1177 sctp_register_pf(&sctp_pf_inet6, PF_INET6); 1178 1179 /* Register the SCTP specific AF_INET6 functions. */ 1180 sctp_register_af(&sctp_af_inet6); 1181 } 1182 1183 void sctp_v6_pf_exit(void) 1184 { 1185 list_del(&sctp_af_inet6.list); 1186 } 1187 1188 /* Initialize IPv6 support and register with socket layer. */ 1189 int sctp_v6_protosw_init(void) 1190 { 1191 int rc; 1192 1193 rc = proto_register(&sctpv6_prot, 1); 1194 if (rc) 1195 return rc; 1196 1197 /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */ 1198 inet6_register_protosw(&sctpv6_seqpacket_protosw); 1199 inet6_register_protosw(&sctpv6_stream_protosw); 1200 1201 return 0; 1202 } 1203 1204 void sctp_v6_protosw_exit(void) 1205 { 1206 inet6_unregister_protosw(&sctpv6_seqpacket_protosw); 1207 inet6_unregister_protosw(&sctpv6_stream_protosw); 1208 proto_unregister(&sctpv6_prot); 1209 } 1210 1211 1212 /* Register with inet6 layer. */ 1213 int sctp_v6_add_protocol(void) 1214 { 1215 /* Register notifier for inet6 address additions/deletions. */ 1216 register_inet6addr_notifier(&sctp_inet6addr_notifier); 1217 1218 if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0) 1219 return -EAGAIN; 1220 1221 return 0; 1222 } 1223 1224 /* Unregister with inet6 layer. */ 1225 void sctp_v6_del_protocol(void) 1226 { 1227 inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP); 1228 unregister_inet6addr_notifier(&sctp_inet6addr_notifier); 1229 } 1230