net/sctp/ipv6.c

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