net/sctp/ipv6.c

   1 /* SCTP kernel reference Implementation
   2  * (C) Copyright IBM Corp. 2002, 2004
   3  * Copyright (c) 2001 Nokia, Inc.
   4  * Copyright (c) 2001 La Monte H.P. Yarroll
   5  * Copyright (c) 2002-2003 Intel Corp.
   6  *
   7  * This file is part of the SCTP kernel reference Implementation
   8  *
   9  * SCTP over IPv6.
  10  *
  11  * The SCTP reference implementation is free software;
  12  * you can redistribute it and/or modify it under the terms of
  13  * the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2, or (at your option)
  15  * any later version.
  16  *
  17  * The SCTP reference implementation is distributed in the hope that it
  18  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
  19  *                 ************************
  20  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  21  * See the GNU General Public License for more details.
  22  *
  23  * You should have received a copy of the GNU General Public License
  24  * along with GNU CC; see the file COPYING.  If not, write to
  25  * the Free Software Foundation, 59 Temple Place - Suite 330,
  26  * Boston, MA 02111-1307, USA.
  27  *
  28  * Please send any bug reports or fixes you make to the
  29  * email address(es):
  30  *    lksctp developers <lksctp-developers@lists.sourceforge.net>
  31  *
  32  * Or submit a bug report through the following website:
  33  *    http://www.sf.net/projects/lksctp
  34  *
  35  * Written or modified by:
  36  *    Le Yanqun             <yanqun.le@nokia.com>
  37  *    Hui Huang             <hui.huang@nokia.com>
  38  *    La Monte H.P. Yarroll <piggy@acm.org>
  39  *    Sridhar Samudrala     <sri@us.ibm.com>
  40  *    Jon Grimm             <jgrimm@us.ibm.com>
  41  *    Ardelle Fan           <ardelle.fan@intel.com>
  42  *
  43  * Based on:
  44  *      linux/net/ipv6/tcp_ipv6.c
  45  *
  46  * Any bugs reported given to us we will try to fix... any fixes shared will
  47  * be incorporated into the next SCTP release.
  48  */
  49
  50 #include <linux/module.h>
  51 #include <linux/errno.h>
  52 #include <linux/types.h>
  53 #include <linux/socket.h>
  54 #include <linux/sockios.h>
  55 #include <linux/net.h>
  56 #include <linux/sched.h>
  57 #include <linux/in.h>
  58 #include <linux/in6.h>
  59 #include <linux/netdevice.h>
  60 #include <linux/init.h>
  61 #include <linux/ipsec.h>
  62
  63 #include <linux/ipv6.h>
  64 #include <linux/icmpv6.h>
  65 #include <linux/random.h>
  66 #include <linux/seq_file.h>
  67
  68 #include <net/protocol.h>
  69 #include <net/tcp.h>
  70 #include <net/ndisc.h>
  71 #include <net/ipv6.h>
  72 #include <net/transp_v6.h>
  73 #include <net/addrconf.h>
  74 #include <net/ip6_route.h>
  75 #include <net/inet_common.h>
  76 #include <net/inet_ecn.h>
  77 #include <net/sctp/sctp.h>
  78
  79 #include <asm/uaccess.h>
  80
  81 extern int sctp_inetaddr_event(struct notifier_block *, unsigned long, void *);
  82 static struct notifier_block sctp_inet6addr_notifier = {
  83         .notifier_call = sctp_inetaddr_event,
  84 };
  85
  86 /* ICMP error handler. */
  87 void sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
  88                  int type, int code, int offset, __u32 info)
  89 {
  90         struct inet6_dev *idev;
  91         struct ipv6hdr *iph = (struct ipv6hdr *)skb->data;
  92         struct sctphdr *sh = (struct sctphdr *)(skb->data + offset);
  93         struct sock *sk;
  94         struct sctp_endpoint *ep;
  95         struct sctp_association *asoc;
  96         struct sctp_transport *transport;
  97         struct ipv6_pinfo *np;
  98         char *saveip, *savesctp;
  99         int err;
 100
 101         idev = in6_dev_get(skb->dev);
 102
 103         /* Fix up skb to look at the embedded net header. */
 104         saveip = skb->nh.raw;
 105         savesctp  = skb->h.raw;
 106         skb->nh.ipv6h = iph;
 107         skb->h.raw = (char *)sh;
 108         sk = sctp_err_lookup(AF_INET6, skb, sh, &ep, &asoc, &transport);
 109         /* Put back, the original pointers. */
 110         skb->nh.raw = saveip;
 111         skb->h.raw = savesctp;
 112         if (!sk) {
 113                 ICMP6_INC_STATS_BH(idev, ICMP6_MIB_INERRORS);
 114                 goto out;
 115         }
 116
 117         /* Warning:  The sock lock is held.  Remember to call
 118          * sctp_err_finish!
 119          */
 120
 121         switch (type) {
 122         case ICMPV6_PKT_TOOBIG:
 123                 sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
 124                 goto out_unlock;
 125         default:
 126                 break;
 127         }
 128
 129         np = inet6_sk(sk);
 130         icmpv6_err_convert(type, code, &err);
 131         if (!sock_owned_by_user(sk) && np->recverr) {
 132                 sk->sk_err = err;
 133                 sk->sk_error_report(sk);
 134         } else {  /* Only an error on timeout */
 135                 sk->sk_err_soft = err;
 136         }
 137
 138 out_unlock:
 139         sctp_err_finish(sk, ep, asoc);
 140 out:
 141         if (likely(idev != NULL))
 142                 in6_dev_put(idev);
 143 }
 144
 145 /* Based on tcp_v6_xmit() in tcp_ipv6.c. */
 146 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport,
 147                         int ipfragok)
 148 {
 149         struct sock *sk = skb->sk;
 150         struct ipv6_pinfo *np = inet6_sk(sk);
 151         struct flowi fl;
 152
 153         memset(&fl, 0, sizeof(fl));
 154
 155         fl.proto = sk->sk_protocol;
 156
 157         /* Fill in the dest address from the route entry passed with the skb
 158          * and the source address from the transport.
 159          */
 160         ipv6_addr_copy(&fl.fl6_dst, &transport->ipaddr.v6.sin6_addr);
 161         ipv6_addr_copy(&fl.fl6_src, &transport->saddr.v6.sin6_addr);
 162
 163         fl.fl6_flowlabel = np->flow_label;
 164         IP6_ECN_flow_xmit(sk, fl.fl6_flowlabel);
 165         if (ipv6_addr_type(&fl.fl6_src) & IPV6_ADDR_LINKLOCAL)
 166                 fl.oif = transport->saddr.v6.sin6_scope_id;
 167         else
 168                 fl.oif = sk->sk_bound_dev_if;
 169         fl.fl_ip_sport = inet_sk(sk)->sport;
 170         fl.fl_ip_dport = transport->ipaddr.v6.sin6_port;
 171
 172         if (np->opt && np->opt->srcrt) {
 173                 struct rt0_hdr *rt0 = (struct rt0_hdr *) np->opt->srcrt;
 174                 ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
 175         }
 176
 177         SCTP_DEBUG_PRINTK("%s: skb:%p, len:%d, "
 178                           "src:%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x "
 179                           "dst:%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
 180                           __FUNCTION__, skb, skb->len,
 181                           NIP6(fl.fl6_src), NIP6(fl.fl6_dst));
 182
 183         SCTP_INC_STATS(SCTP_MIB_OUTSCTPPACKS);
 184
 185         return ip6_xmit(sk, skb, &fl, np->opt, ipfragok);
 186 }
 187
 188 /* Returns the dst cache entry for the given source and destination ip
 189  * addresses.
 190  */
 191 struct dst_entry *sctp_v6_get_dst(struct sctp_association *asoc,
 192                                   union sctp_addr *daddr,
 193                                   union sctp_addr *saddr)
 194 {
 195         struct dst_entry *dst;
 196         struct flowi fl;
 197
 198         memset(&fl, 0, sizeof(fl));
 199         ipv6_addr_copy(&fl.fl6_dst, &daddr->v6.sin6_addr);
 200         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
 201                 fl.oif = daddr->v6.sin6_scope_id;
 202
 203
 204         SCTP_DEBUG_PRINTK("%s: DST=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ",
 205                           __FUNCTION__, NIP6(fl.fl6_dst));
 206
 207         if (saddr) {
 208                 ipv6_addr_copy(&fl.fl6_src, &saddr->v6.sin6_addr);
 209                 SCTP_DEBUG_PRINTK(
 210                         "SRC=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x - ",
 211                         NIP6(fl.fl6_src));
 212         }
 213
 214         dst = ip6_route_output(NULL, &fl);
 215         if (dst) {
 216                 struct rt6_info *rt;
 217                 rt = (struct rt6_info *)dst;
 218                 SCTP_DEBUG_PRINTK(
 219                         "rt6_dst:%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x "
 220                         "rt6_src:%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
 221                         NIP6(rt->rt6i_dst.addr), NIP6(rt->rt6i_src.addr));
 222         } else {
 223                 SCTP_DEBUG_PRINTK("NO ROUTE\n");
 224         }
 225
 226         return dst;
 227 }
 228
 229 /* Returns the number of consecutive initial bits that match in the 2 ipv6
 230  * addresses.
 231  */
 232 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
 233                                          union sctp_addr *s2)
 234 {
 235         struct in6_addr *a1 = &s1->v6.sin6_addr;
 236         struct in6_addr *a2 = &s2->v6.sin6_addr;
 237         int i, j;
 238
 239         for (i = 0; i < 4 ; i++) {
 240                 __u32 a1xora2;
 241
 242                 a1xora2 = a1->s6_addr32[i] ^ a2->s6_addr32[i];
 243
 244                 if ((j = fls(ntohl(a1xora2))))
 245                         return (i * 32 + 32 - j);
 246         }
 247
 248         return (i*32);
 249 }
 250
 251 /* Fills in the source address(saddr) based on the destination address(daddr)
 252  * and asoc's bind address list.
 253  */
 254 void sctp_v6_get_saddr(struct sctp_association *asoc, struct dst_entry *dst,
 255                        union sctp_addr *daddr, union sctp_addr *saddr)
 256 {
 257         struct sctp_bind_addr *bp;
 258         rwlock_t *addr_lock;
 259         struct sctp_sockaddr_entry *laddr;
 260         struct list_head *pos;
 261         sctp_scope_t scope;
 262         union sctp_addr *baddr = NULL;
 263         __u8 matchlen = 0;
 264         __u8 bmatchlen;
 265
 266         SCTP_DEBUG_PRINTK("%s: asoc:%p dst:%p "
 267                           "daddr:%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ",
 268                           __FUNCTION__, asoc, dst, NIP6(daddr->v6.sin6_addr));
 269
 270         if (!asoc) {
 271                 ipv6_get_saddr(dst, &daddr->v6.sin6_addr,&saddr->v6.sin6_addr);
 272                 SCTP_DEBUG_PRINTK("saddr from ipv6_get_saddr: "
 273                                   "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
 274                                   NIP6(saddr->v6.sin6_addr));
 275                 return;
 276         }
 277
 278         scope = sctp_scope(daddr);
 279
 280         bp = &asoc->base.bind_addr;
 281         addr_lock = &asoc->base.addr_lock;
 282
 283         /* Go through the bind address list and find the best source address
 284          * that matches the scope of the destination address.
 285          */
 286         sctp_read_lock(addr_lock);
 287         list_for_each(pos, &bp->address_list) {
 288                 laddr = list_entry(pos, struct sctp_sockaddr_entry, list);
 289                 if ((laddr->a.sa.sa_family == AF_INET6) &&
 290                     (scope <= sctp_scope(&laddr->a))) {
 291                         bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
 292                         if (!baddr || (matchlen < bmatchlen)) {
 293                                 baddr = &laddr->a;
 294                                 matchlen = bmatchlen;
 295                         }
 296                 }
 297         }
 298
 299         if (baddr) {
 300                 memcpy(saddr, baddr, sizeof(union sctp_addr));
 301                 SCTP_DEBUG_PRINTK("saddr: "
 302                                   "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
 303                                   NIP6(saddr->v6.sin6_addr));
 304         } else {
 305                 printk(KERN_ERR "%s: asoc:%p Could not find a valid source "
 306                        "address for the "
 307                        "dest:%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x\n",
 308                        __FUNCTION__, asoc, NIP6(daddr->v6.sin6_addr));
 309         }
 310
 311         sctp_read_unlock(addr_lock);
 312 }
 313
 314 /* Make a copy of all potential local addresses. */
 315 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
 316                                   struct net_device *dev)
 317 {
 318         struct inet6_dev *in6_dev;
 319         struct inet6_ifaddr *ifp;
 320         struct sctp_sockaddr_entry *addr;
 321
 322         read_lock(&addrconf_lock);
 323         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
 324                 read_unlock(&addrconf_lock);
 325                 return;
 326         }
 327
 328         read_lock(&in6_dev->lock);
 329         for (ifp = in6_dev->addr_list; ifp; ifp = ifp->if_next) {
 330                 /* Add the address to the local list.  */
 331                 addr = t_new(struct sctp_sockaddr_entry, GFP_ATOMIC);
 332                 if (addr) {
 333                         addr->a.v6.sin6_family = AF_INET6;
 334                         addr->a.v6.sin6_port = 0;
 335                         addr->a.v6.sin6_addr = ifp->addr;
 336                         addr->a.v6.sin6_scope_id = dev->ifindex;
 337                         INIT_LIST_HEAD(&addr->list);
 338                         list_add_tail(&addr->list, addrlist);
 339                 }
 340         }
 341
 342         read_unlock(&in6_dev->lock);
 343         read_unlock(&addrconf_lock);
 344 }
 345
 346 /* Initialize a sockaddr_storage from in incoming skb. */
 347 static void sctp_v6_from_skb(union sctp_addr *addr,struct sk_buff *skb,
 348                              int is_saddr)
 349 {
 350         void *from;
 351         __u16 *port;
 352         struct sctphdr *sh;
 353
 354         port = &addr->v6.sin6_port;
 355         addr->v6.sin6_family = AF_INET6;
 356         addr->v6.sin6_flowinfo = 0; /* FIXME */
 357         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
 358
 359         sh = (struct sctphdr *) skb->h.raw;
 360         if (is_saddr) {
 361                 *port  = ntohs(sh->source);
 362                 from = &skb->nh.ipv6h->saddr;
 363         } else {
 364                 *port = ntohs(sh->dest);
 365                 from = &skb->nh.ipv6h->daddr;
 366         }
 367         ipv6_addr_copy(&addr->v6.sin6_addr, from);
 368 }
 369
 370 /* Initialize an sctp_addr from a socket. */
 371 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
 372 {
 373         addr->v6.sin6_family = AF_INET6;
 374         addr->v6.sin6_port = inet_sk(sk)->num;
 375         addr->v6.sin6_addr = inet6_sk(sk)->rcv_saddr;
 376 }
 377
 378 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
 379 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
 380 {
 381         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
 382                 inet6_sk(sk)->rcv_saddr.s6_addr32[0] = 0;
 383                 inet6_sk(sk)->rcv_saddr.s6_addr32[1] = 0;
 384                 inet6_sk(sk)->rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
 385                 inet6_sk(sk)->rcv_saddr.s6_addr32[3] =
 386                         addr->v4.sin_addr.s_addr;
 387         } else {
 388                 inet6_sk(sk)->rcv_saddr = addr->v6.sin6_addr;
 389         }
 390 }
 391
 392 /* Initialize sk->sk_daddr from sctp_addr. */
 393 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
 394 {
 395         if (addr->sa.sa_family == AF_INET && sctp_sk(sk)->v4mapped) {
 396                 inet6_sk(sk)->daddr.s6_addr32[0] = 0;
 397                 inet6_sk(sk)->daddr.s6_addr32[1] = 0;
 398                 inet6_sk(sk)->daddr.s6_addr32[2] = htonl(0x0000ffff);
 399                 inet6_sk(sk)->daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
 400         } else {
 401                 inet6_sk(sk)->daddr = addr->v6.sin6_addr;
 402         }
 403 }
 404
 405 /* Initialize a sctp_addr from an address parameter. */
 406 static void sctp_v6_from_addr_param(union sctp_addr *addr,
 407                                     union sctp_addr_param *param,
 408                                     __u16 port, int iif)
 409 {
 410         addr->v6.sin6_family = AF_INET6;
 411         addr->v6.sin6_port = port;
 412         addr->v6.sin6_flowinfo = 0; /* BUG */
 413         ipv6_addr_copy(&addr->v6.sin6_addr, &param->v6.addr);
 414         addr->v6.sin6_scope_id = iif;
 415 }
 416
 417 /* Initialize an address parameter from a sctp_addr and return the length
 418  * of the address parameter.
 419  */
 420 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
 421                                  union sctp_addr_param *param)
 422 {
 423         int length = sizeof(sctp_ipv6addr_param_t);
 424
 425         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
 426         param->v6.param_hdr.length = ntohs(length);
 427         ipv6_addr_copy(&param->v6.addr, &addr->v6.sin6_addr);
 428
 429         return length;
 430 }
 431
 432 /* Initialize a sctp_addr from a dst_entry. */
 433 static void sctp_v6_dst_saddr(union sctp_addr *addr, struct dst_entry *dst,
 434                               unsigned short port)
 435 {
 436         struct rt6_info *rt = (struct rt6_info *)dst;
 437         addr->sa.sa_family = AF_INET6;
 438         addr->v6.sin6_port = port;
 439         ipv6_addr_copy(&addr->v6.sin6_addr, &rt->rt6i_src.addr);
 440 }
 441
 442 /* Compare addresses exactly.
 443  * v4-mapped-v6 is also in consideration.
 444  */
 445 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
 446                             const union sctp_addr *addr2)
 447 {
 448         if (addr1->sa.sa_family != addr2->sa.sa_family) {
 449                 if (addr1->sa.sa_family == AF_INET &&
 450                     addr2->sa.sa_family == AF_INET6 &&
 451                     IPV6_ADDR_MAPPED == ipv6_addr_type(&addr2->v6.sin6_addr)) {
 452                         if (addr2->v6.sin6_port == addr1->v4.sin_port &&
 453                             addr2->v6.sin6_addr.s6_addr32[3] ==
 454                             addr1->v4.sin_addr.s_addr)
 455                                 return 1;
 456                 }
 457                 if (addr2->sa.sa_family == AF_INET &&
 458                     addr1->sa.sa_family == AF_INET6 &&
 459                     IPV6_ADDR_MAPPED == ipv6_addr_type(&addr1->v6.sin6_addr)) {
 460                         if (addr1->v6.sin6_port == addr2->v4.sin_port &&
 461                             addr1->v6.sin6_addr.s6_addr32[3] ==
 462                             addr2->v4.sin_addr.s_addr)
 463                                 return 1;
 464                 }
 465                 return 0;
 466         }
 467         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
 468                 return 0;
 469         /* If this is a linklocal address, compare the scope_id. */
 470         if (ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 471                 if (addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
 472                     (addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)) {
 473                         return 0;
 474                 }
 475         }
 476
 477         return 1;
 478 }
 479
 480 /* Initialize addr struct to INADDR_ANY. */
 481 static void sctp_v6_inaddr_any(union sctp_addr *addr, unsigned short port)
 482 {
 483         memset(addr, 0x00, sizeof(union sctp_addr));
 484         addr->v6.sin6_family = AF_INET6;
 485         addr->v6.sin6_port = port;
 486 }
 487
 488 /* Is this a wildcard address? */
 489 static int sctp_v6_is_any(const union sctp_addr *addr)
 490 {
 491         int type;
 492         type = ipv6_addr_type((struct in6_addr *)&addr->v6.sin6_addr);
 493         return IPV6_ADDR_ANY == type;
 494 }
 495
 496 /* Should this be available for binding?   */
 497 static int sctp_v6_available(union sctp_addr *addr, struct sctp_opt *sp)
 498 {
 499         int type;
 500         struct in6_addr *in6 = (struct in6_addr *)&addr->v6.sin6_addr;
 501
 502         type = ipv6_addr_type(in6);
 503         if (IPV6_ADDR_ANY == type)
 504                 return 1;
 505         if (type == IPV6_ADDR_MAPPED) {
 506                 if (sp && !sp->v4mapped)
 507                         return 0;
 508                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 509                         return 0;
 510                 sctp_v6_map_v4(addr);
 511                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
 512         }
 513         if (!(type & IPV6_ADDR_UNICAST))
 514                 return 0;
 515
 516         return ipv6_chk_addr(in6, NULL, 0);
 517 }
 518
 519 /* This function checks if the address is a valid address to be used for
 520  * SCTP.
 521  *
 522  * Output:
 523  * Return 0 - If the address is a non-unicast or an illegal address.
 524  * Return 1 - If the address is a unicast.
 525  */
 526 static int sctp_v6_addr_valid(union sctp_addr *addr, struct sctp_opt *sp)
 527 {
 528         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
 529
 530         /* Support v4-mapped-v6 address. */
 531         if (ret == IPV6_ADDR_MAPPED) {
 532                 /* Note: This routine is used in input, so v4-mapped-v6
 533                  * are disallowed here when there is no sctp_opt.
 534                  */
 535                 if (!sp || !sp->v4mapped)
 536                         return 0;
 537                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
 538                         return 0;
 539                 sctp_v6_map_v4(addr);
 540                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp);
 541         }
 542
 543         /* Is this a non-unicast address */
 544         if (!(ret & IPV6_ADDR_UNICAST))
 545                 return 0;
 546
 547         return 1;
 548 }
 549
 550 /* What is the scope of 'addr'?  */
 551 static sctp_scope_t sctp_v6_scope(union sctp_addr *addr)
 552 {
 553         int v6scope;
 554         sctp_scope_t retval;
 555
 556         /* The IPv6 scope is really a set of bit fields.
 557          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
 558          */
 559
 560         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
 561         switch (v6scope) {
 562         case IFA_HOST:
 563                 retval = SCTP_SCOPE_LOOPBACK;
 564                 break;
 565         case IFA_LINK:
 566                 retval = SCTP_SCOPE_LINK;
 567                 break;
 568         case IFA_SITE:
 569                 retval = SCTP_SCOPE_PRIVATE;
 570                 break;
 571         default:
 572                 retval = SCTP_SCOPE_GLOBAL;
 573                 break;
 574         };
 575
 576         return retval;
 577 }
 578
 579 /* Create and initialize a new sk for the socket to be returned by accept(). */
 580 struct sock *sctp_v6_create_accept_sk(struct sock *sk,
 581                                       struct sctp_association *asoc)
 582 {
 583         struct inet_opt *inet = inet_sk(sk);
 584         struct sock *newsk;
 585         struct inet_opt *newinet;
 586         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
 587         struct sctp6_sock *newsctp6sk;
 588
 589         newsk = sk_alloc(PF_INET6, GFP_KERNEL, sk->sk_prot->slab_obj_size,
 590                          sk->sk_prot->slab);
 591         if (!newsk)
 592                 goto out;
 593
 594         sock_init_data(NULL, newsk);
 595         sk_set_owner(newsk, THIS_MODULE);
 596
 597         newsk->sk_type = SOCK_STREAM;
 598
 599         newsk->sk_prot = sk->sk_prot;
 600         newsk->sk_no_check = sk->sk_no_check;
 601         newsk->sk_reuse = sk->sk_reuse;
 602
 603         newsk->sk_destruct = inet_sock_destruct;
 604         newsk->sk_zapped = 0;
 605         newsk->sk_family = PF_INET6;
 606         newsk->sk_protocol = IPPROTO_SCTP;
 607         newsk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
 608         newsk->sk_shutdown = sk->sk_shutdown;
 609
 610         newsctp6sk = (struct sctp6_sock *)newsk;
 611         newsctp6sk->pinet6 = &newsctp6sk->inet6;
 612
 613         newinet = inet_sk(newsk);
 614         newnp = inet6_sk(newsk);
 615
 616         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
 617
 618         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
 619          * and getpeername().
 620          */
 621         newinet->sport = inet->sport;
 622         newnp->saddr = np->saddr;
 623         newnp->rcv_saddr = np->rcv_saddr;
 624         newinet->dport = htons(asoc->peer.port);
 625         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
 626
 627         /* Init the ipv4 part of the socket since we can have sockets
 628          * using v6 API for ipv4.
 629          */
 630         newinet->uc_ttl = -1;
 631         newinet->mc_loop = 1;
 632         newinet->mc_ttl = 1;
 633         newinet->mc_index = 0;
 634         newinet->mc_list = NULL;
 635
 636         if (ipv4_config.no_pmtu_disc)
 637                 newinet->pmtudisc = IP_PMTUDISC_DONT;
 638         else
 639                 newinet->pmtudisc = IP_PMTUDISC_WANT;
 640
 641 #ifdef INET_REFCNT_DEBUG
 642         atomic_inc(&inet6_sock_nr);
 643         atomic_inc(&inet_sock_nr);
 644 #endif
 645
 646         if (newsk->sk_prot->init(newsk)) {
 647                 sk_common_release(newsk);
 648                 newsk = NULL;
 649         }
 650
 651 out:
 652         return newsk;
 653 }
 654
 655 /* Map v4 address to mapped v6 address */
 656 static void sctp_v6_addr_v4map(struct sctp_opt *sp, union sctp_addr *addr)
 657 {
 658         if (sp->v4mapped && AF_INET == addr->sa.sa_family)
 659                 sctp_v4_map_v6(addr);
 660 }
 661
 662 /* Where did this skb come from?  */
 663 static int sctp_v6_skb_iif(const struct sk_buff *skb)
 664 {
 665         struct inet6_skb_parm *opt = (struct inet6_skb_parm *) skb->cb;
 666         return opt->iif;
 667 }
 668
 669 /* Was this packet marked by Explicit Congestion Notification? */
 670 static int sctp_v6_is_ce(const struct sk_buff *skb)
 671 {
 672         return *((__u32 *)(skb->nh.ipv6h)) & htonl(1<<20);
 673 }
 674
 675 /* Dump the v6 addr to the seq file. */
 676 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
 677 {
 678         seq_printf(seq, "%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ",
 679                    NIP6(addr->v6.sin6_addr));
 680 }
 681
 682 /* Initialize a PF_INET6 socket msg_name. */
 683 static void sctp_inet6_msgname(char *msgname, int *addr_len)
 684 {
 685         struct sockaddr_in6 *sin6;
 686
 687         sin6 = (struct sockaddr_in6 *)msgname;
 688         sin6->sin6_family = AF_INET6;
 689         sin6->sin6_flowinfo = 0;
 690         sin6->sin6_scope_id = 0; /*FIXME */
 691         *addr_len = sizeof(struct sockaddr_in6);
 692 }
 693
 694 /* Initialize a PF_INET msgname from a ulpevent. */
 695 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
 696                                      char *msgname, int *addrlen)
 697 {
 698         struct sockaddr_in6 *sin6, *sin6from;
 699
 700         if (msgname) {
 701                 union sctp_addr *addr;
 702                 struct sctp_association *asoc;
 703
 704                 asoc = event->asoc;
 705                 sctp_inet6_msgname(msgname, addrlen);
 706                 sin6 = (struct sockaddr_in6 *)msgname;
 707                 sin6->sin6_port = htons(asoc->peer.port);
 708                 addr = &asoc->peer.primary_addr;
 709
 710                 /* Note: If we go to a common v6 format, this code
 711                  * will change.
 712                  */
 713
 714                 /* Map ipv4 address into v4-mapped-on-v6 address.  */
 715                 if (sctp_sk(asoc->base.sk)->v4mapped &&
 716                     AF_INET == addr->sa.sa_family) {
 717                         sctp_v4_map_v6((union sctp_addr *)sin6);
 718                         sin6->sin6_addr.s6_addr32[3] =
 719                                 addr->v4.sin_addr.s_addr;
 720                         return;
 721                 }
 722
 723                 sin6from = &asoc->peer.primary_addr.v6;
 724                 ipv6_addr_copy(&sin6->sin6_addr, &sin6from->sin6_addr);
 725                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL)
 726                         sin6->sin6_scope_id = sin6from->sin6_scope_id;
 727         }
 728 }
 729
 730 /* Initialize a msg_name from an inbound skb. */
 731 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
 732                                    int *addr_len)
 733 {
 734         struct sctphdr *sh;
 735         struct sockaddr_in6 *sin6;
 736
 737         if (msgname) {
 738                 sctp_inet6_msgname(msgname, addr_len);
 739                 sin6 = (struct sockaddr_in6 *)msgname;
 740                 sh = (struct sctphdr *)skb->h.raw;
 741                 sin6->sin6_port = sh->source;
 742
 743                 /* Map ipv4 address into v4-mapped-on-v6 address. */
 744                 if (sctp_sk(skb->sk)->v4mapped &&
 745                     skb->nh.iph->version == 4) {
 746                         sctp_v4_map_v6((union sctp_addr *)sin6);
 747                         sin6->sin6_addr.s6_addr32[3] = skb->nh.iph->saddr;
 748                         return;
 749                 }
 750
 751                 /* Otherwise, just copy the v6 address. */
 752                 ipv6_addr_copy(&sin6->sin6_addr, &skb->nh.ipv6h->saddr);
 753                 if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LINKLOCAL) {
 754                         struct sctp_ulpevent *ev = sctp_skb2event(skb);
 755                         sin6->sin6_scope_id = ev->iif;
 756                 }
 757         }
 758 }
 759
 760 /* Do we support this AF? */
 761 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_opt *sp)
 762 {
 763         switch (family) {
 764         case AF_INET6:
 765                 return 1;
 766         /* v4-mapped-v6 addresses */
 767         case AF_INET:
 768                 if (!__ipv6_only_sock(sctp_opt2sk(sp)) && sp->v4mapped)
 769                         return 1;
 770         default:
 771                 return 0;
 772         }
 773 }
 774
 775 /* Address matching with wildcards allowed.  This extra level
 776  * of indirection lets us choose whether a PF_INET6 should
 777  * disallow any v4 addresses if we so choose.
 778  */
 779 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
 780                                const union sctp_addr *addr2,
 781                                struct sctp_opt *opt)
 782 {
 783         struct sctp_af *af1, *af2;
 784
 785         af1 = sctp_get_af_specific(addr1->sa.sa_family);
 786         af2 = sctp_get_af_specific(addr2->sa.sa_family);
 787
 788         if (!af1 || !af2)
 789                 return 0;
 790         /* Today, wildcard AF_INET/AF_INET6. */
 791         if (sctp_is_any(addr1) || sctp_is_any(addr2))
 792                 return 1;
 793
 794         if (addr1->sa.sa_family != addr2->sa.sa_family)
 795                 return 0;
 796
 797         return af1->cmp_addr(addr1, addr2);
 798 }
 799
 800 /* Verify that the provided sockaddr looks bindable.   Common verification,
 801  * has already been taken care of.
 802  */
 803 static int sctp_inet6_bind_verify(struct sctp_opt *opt, union sctp_addr *addr)
 804 {
 805         struct sctp_af *af;
 806
 807         /* ASSERT: address family has already been verified. */
 808         if (addr->sa.sa_family != AF_INET6)
 809                 af = sctp_get_af_specific(addr->sa.sa_family);
 810         else {
 811                 struct sock *sk;
 812                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 813                 sk = sctp_opt2sk(opt);
 814                 if (type & IPV6_ADDR_LINKLOCAL) {
 815                         /* Note: Behavior similar to af_inet6.c:
 816                          *  1) Overrides previous bound_dev_if
 817                          *  2) Destructive even if bind isn't successful.
 818                          */
 819
 820                         if (addr->v6.sin6_scope_id)
 821                                 sk->sk_bound_dev_if = addr->v6.sin6_scope_id;
 822                         if (!sk->sk_bound_dev_if)
 823                                 return 0;
 824                 }
 825                 af = opt->pf->af;
 826         }
 827         return af->available(addr, opt);
 828 }
 829
 830 /* Verify that the provided sockaddr looks bindable.   Common verification,
 831  * has already been taken care of.
 832  */
 833 static int sctp_inet6_send_verify(struct sctp_opt *opt, union sctp_addr *addr)
 834 {
 835         struct sctp_af *af = NULL;
 836
 837         /* ASSERT: address family has already been verified. */
 838         if (addr->sa.sa_family != AF_INET6)
 839                 af = sctp_get_af_specific(addr->sa.sa_family);
 840         else {
 841                 struct sock *sk;
 842                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
 843                 sk = sctp_opt2sk(opt);
 844                 if (type & IPV6_ADDR_LINKLOCAL) {
 845                         /* Note: Behavior similar to af_inet6.c:
 846                          *  1) Overrides previous bound_dev_if
 847                          *  2) Destructive even if bind isn't successful.
 848                          */
 849
 850                         if (addr->v6.sin6_scope_id)
 851                                 sk->sk_bound_dev_if = addr->v6.sin6_scope_id;
 852                         if (!sk->sk_bound_dev_if)
 853                                 return 0;
 854                 }
 855                 af = opt->pf->af;
 856         }
 857
 858         return af != NULL;
 859 }
 860
 861 /* Fill in Supported Address Type information for INIT and INIT-ACK
 862  * chunks.   Note: In the future, we may want to look at sock options
 863  * to determine whether a PF_INET6 socket really wants to have IPV4
 864  * addresses.
 865  * Returns number of addresses supported.
 866  */
 867 static int sctp_inet6_supported_addrs(const struct sctp_opt *opt,
 868                                       __u16 *types)
 869 {
 870         types[0] = SCTP_PARAM_IPV4_ADDRESS;
 871         types[1] = SCTP_PARAM_IPV6_ADDRESS;
 872         return 2;
 873 }
 874
 875 static struct proto_ops inet6_seqpacket_ops = {
 876         .family     = PF_INET6,
 877         .owner      = THIS_MODULE,
 878         .release    = inet6_release,
 879         .bind       = inet6_bind,
 880         .connect    = inet_dgram_connect,
 881         .socketpair = sock_no_socketpair,
 882         .accept     = inet_accept,
 883         .getname    = inet6_getname,
 884         .poll       = sctp_poll,
 885         .ioctl      = inet6_ioctl,
 886         .listen     = sctp_inet_listen,
 887         .shutdown   = inet_shutdown,
 888         .setsockopt = sock_common_setsockopt,
 889         .getsockopt = sock_common_getsockopt,
 890         .sendmsg    = inet_sendmsg,
 891         .recvmsg    = sock_common_recvmsg,
 892         .mmap       = sock_no_mmap,
 893 };
 894
 895 static struct inet_protosw sctpv6_seqpacket_protosw = {
 896         .type          = SOCK_SEQPACKET,
 897         .protocol      = IPPROTO_SCTP,
 898         .prot          = &sctpv6_prot,
 899         .ops           = &inet6_seqpacket_ops,
 900         .capability    = -1,
 901         .no_check      = 0,
 902         .flags         = SCTP_PROTOSW_FLAG
 903 };
 904 static struct inet_protosw sctpv6_stream_protosw = {
 905         .type          = SOCK_STREAM,
 906         .protocol      = IPPROTO_SCTP,
 907         .prot          = &sctpv6_prot,
 908         .ops           = &inet6_seqpacket_ops,
 909         .capability    = -1,
 910         .no_check      = 0,
 911         .flags         = SCTP_PROTOSW_FLAG,
 912 };
 913
 914 static int sctp6_rcv(struct sk_buff **pskb, unsigned int *nhoffp)
 915 {
 916         return sctp_rcv(*pskb) ? -1 : 0;
 917 }
 918
 919 static struct inet6_protocol sctpv6_protocol = {
 920         .handler      = sctp6_rcv,
 921         .err_handler  = sctp_v6_err,
 922         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
 923 };
 924
 925 static struct sctp_af sctp_ipv6_specific = {
 926         .sctp_xmit       = sctp_v6_xmit,
 927         .setsockopt      = ipv6_setsockopt,
 928         .getsockopt      = ipv6_getsockopt,
 929         .get_dst         = sctp_v6_get_dst,
 930         .get_saddr       = sctp_v6_get_saddr,
 931         .copy_addrlist   = sctp_v6_copy_addrlist,
 932         .from_skb        = sctp_v6_from_skb,
 933         .from_sk         = sctp_v6_from_sk,
 934         .to_sk_saddr     = sctp_v6_to_sk_saddr,
 935         .to_sk_daddr     = sctp_v6_to_sk_daddr,
 936         .from_addr_param = sctp_v6_from_addr_param,
 937         .to_addr_param   = sctp_v6_to_addr_param,
 938         .dst_saddr       = sctp_v6_dst_saddr,
 939         .cmp_addr        = sctp_v6_cmp_addr,
 940         .scope           = sctp_v6_scope,
 941         .addr_valid      = sctp_v6_addr_valid,
 942         .inaddr_any      = sctp_v6_inaddr_any,
 943         .is_any          = sctp_v6_is_any,
 944         .available       = sctp_v6_available,
 945         .skb_iif         = sctp_v6_skb_iif,
 946         .is_ce           = sctp_v6_is_ce,
 947         .seq_dump_addr   = sctp_v6_seq_dump_addr,
 948         .net_header_len  = sizeof(struct ipv6hdr),
 949         .sockaddr_len    = sizeof(struct sockaddr_in6),
 950         .sa_family       = AF_INET6,
 951 };
 952
 953 static struct sctp_pf sctp_pf_inet6_specific = {
 954         .event_msgname = sctp_inet6_event_msgname,
 955         .skb_msgname   = sctp_inet6_skb_msgname,
 956         .af_supported  = sctp_inet6_af_supported,
 957         .cmp_addr      = sctp_inet6_cmp_addr,
 958         .bind_verify   = sctp_inet6_bind_verify,
 959         .send_verify   = sctp_inet6_send_verify,
 960         .supported_addrs = sctp_inet6_supported_addrs,
 961         .create_accept_sk = sctp_v6_create_accept_sk,
 962         .addr_v4map    = sctp_v6_addr_v4map,
 963         .af            = &sctp_ipv6_specific,
 964 };
 965
 966 /* Initialize IPv6 support and register with inet6 stack.  */
 967 int sctp_v6_init(void)
 968 {
 969         int rc = sk_alloc_slab(&sctpv6_prot, "sctpv6_sock");
 970
 971         if (rc)
 972                 goto out;
 973         /* Register inet6 protocol. */
 974         rc = -EAGAIN;
 975         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
 976                 goto out_sctp_free_slab;
 977
 978         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
 979         inet6_register_protosw(&sctpv6_seqpacket_protosw);
 980         inet6_register_protosw(&sctpv6_stream_protosw);
 981
 982         /* Register the SCTP specific PF_INET6 functions. */
 983         sctp_register_pf(&sctp_pf_inet6_specific, PF_INET6);
 984
 985         /* Register the SCTP specific AF_INET6 functions. */
 986         sctp_register_af(&sctp_ipv6_specific);
 987
 988         /* Register notifier for inet6 address additions/deletions. */
 989         register_inet6addr_notifier(&sctp_inet6addr_notifier);
 990         rc = 0;
 991 out:
 992         return rc;
 993 out_sctp_free_slab:
 994         sk_free_slab(&sctpv6_prot);
 995         goto out;
 996 }
 997
 998 /* IPv6 specific exit support. */
 999 void sctp_v6_exit(void)
1000 {
1001         list_del(&sctp_ipv6_specific.list);
1002         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1003         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1004         inet6_unregister_protosw(&sctpv6_stream_protosw);
1005         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1006         sk_free_slab(&sctpv6_prot);
1007 }