GNU Linux-libre 6.8.9-gnu
[releases.git] / 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 #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         int err = 0;
132
133         switch (type) {
134         case ICMPV6_PKT_TOOBIG:
135                 if (ip6_sk_accept_pmtu(sk))
136                         sctp_icmp_frag_needed(sk, asoc, t, info);
137                 return;
138         case ICMPV6_PARAMPROB:
139                 if (ICMPV6_UNK_NEXTHDR == code) {
140                         sctp_icmp_proto_unreachable(sk, asoc, t);
141                         return;
142                 }
143                 break;
144         case NDISC_REDIRECT:
145                 sctp_icmp_redirect(sk, t, skb);
146                 return;
147         default:
148                 break;
149         }
150
151         icmpv6_err_convert(type, code, &err);
152         if (!sock_owned_by_user(sk) && inet6_test_bit(RECVERR6, sk)) {
153                 sk->sk_err = err;
154                 sk_error_report(sk);
155         } else {
156                 WRITE_ONCE(sk->sk_err_soft, err);
157         }
158 }
159
160 /* ICMP error handler. */
161 static int sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
162                        u8 type, u8 code, int offset, __be32 info)
163 {
164         struct net *net = dev_net(skb->dev);
165         struct sctp_transport *transport;
166         struct sctp_association *asoc;
167         __u16 saveip, savesctp;
168         struct sock *sk;
169
170         /* Fix up skb to look at the embedded net header. */
171         saveip   = skb->network_header;
172         savesctp = skb->transport_header;
173         skb_reset_network_header(skb);
174         skb_set_transport_header(skb, offset);
175         sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
176         /* Put back, the original pointers. */
177         skb->network_header   = saveip;
178         skb->transport_header = savesctp;
179         if (!sk) {
180                 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS);
181                 return -ENOENT;
182         }
183
184         sctp_v6_err_handle(transport, skb, type, code, ntohl(info));
185         sctp_err_finish(sk, transport);
186
187         return 0;
188 }
189
190 int sctp_udp_v6_err(struct sock *sk, struct sk_buff *skb)
191 {
192         struct net *net = dev_net(skb->dev);
193         struct sctp_association *asoc;
194         struct sctp_transport *t;
195         struct icmp6hdr *hdr;
196         __u32 info = 0;
197
198         skb->transport_header += sizeof(struct udphdr);
199         sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &t);
200         if (!sk) {
201                 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS);
202                 return -ENOENT;
203         }
204
205         skb->transport_header -= sizeof(struct udphdr);
206         hdr = (struct icmp6hdr *)(skb_network_header(skb) - sizeof(struct icmp6hdr));
207         if (hdr->icmp6_type == NDISC_REDIRECT) {
208                 /* can't be handled without outer ip6hdr known, leave it to udpv6_err */
209                 sctp_err_finish(sk, t);
210                 return 0;
211         }
212         if (hdr->icmp6_type == ICMPV6_PKT_TOOBIG)
213                 info = ntohl(hdr->icmp6_mtu);
214         sctp_v6_err_handle(t, skb, hdr->icmp6_type, hdr->icmp6_code, info);
215
216         sctp_err_finish(sk, t);
217         return 1;
218 }
219
220 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *t)
221 {
222         struct dst_entry *dst = dst_clone(t->dst);
223         struct flowi6 *fl6 = &t->fl.u.ip6;
224         struct sock *sk = skb->sk;
225         struct ipv6_pinfo *np = inet6_sk(sk);
226         __u8 tclass = np->tclass;
227         __be32 label;
228
229         pr_debug("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n", __func__, skb,
230                  skb->len, &fl6->saddr, &fl6->daddr);
231
232         if (t->dscp & SCTP_DSCP_SET_MASK)
233                 tclass = t->dscp & SCTP_DSCP_VAL_MASK;
234
235         if (INET_ECN_is_capable(tclass))
236                 IP6_ECN_flow_xmit(sk, fl6->flowlabel);
237
238         if (!(t->param_flags & SPP_PMTUD_ENABLE))
239                 skb->ignore_df = 1;
240
241         SCTP_INC_STATS(sock_net(sk), SCTP_MIB_OUTSCTPPACKS);
242
243         if (!t->encap_port || !sctp_sk(sk)->udp_port) {
244                 int res;
245
246                 skb_dst_set(skb, dst);
247                 rcu_read_lock();
248                 res = ip6_xmit(sk, skb, fl6, sk->sk_mark,
249                                rcu_dereference(np->opt),
250                                tclass, READ_ONCE(sk->sk_priority));
251                 rcu_read_unlock();
252                 return res;
253         }
254
255         if (skb_is_gso(skb))
256                 skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL_CSUM;
257
258         skb->encapsulation = 1;
259         skb_reset_inner_mac_header(skb);
260         skb_reset_inner_transport_header(skb);
261         skb_set_inner_ipproto(skb, IPPROTO_SCTP);
262         label = ip6_make_flowlabel(sock_net(sk), skb, fl6->flowlabel, true, fl6);
263
264         return udp_tunnel6_xmit_skb(dst, sk, skb, NULL, &fl6->saddr,
265                                     &fl6->daddr, tclass, ip6_dst_hoplimit(dst),
266                                     label, sctp_sk(sk)->udp_port, t->encap_port, false);
267 }
268
269 /* Returns the dst cache entry for the given source and destination ip
270  * addresses.
271  */
272 static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
273                             struct flowi *fl, struct sock *sk)
274 {
275         struct sctp_association *asoc = t->asoc;
276         struct dst_entry *dst = NULL;
277         struct flowi _fl;
278         struct flowi6 *fl6 = &_fl.u.ip6;
279         struct sctp_bind_addr *bp;
280         struct ipv6_pinfo *np = inet6_sk(sk);
281         struct sctp_sockaddr_entry *laddr;
282         union sctp_addr *daddr = &t->ipaddr;
283         union sctp_addr dst_saddr;
284         struct in6_addr *final_p, final;
285         enum sctp_scope scope;
286         __u8 matchlen = 0;
287
288         memset(&_fl, 0, sizeof(_fl));
289         fl6->daddr = daddr->v6.sin6_addr;
290         fl6->fl6_dport = daddr->v6.sin6_port;
291         fl6->flowi6_proto = IPPROTO_SCTP;
292         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
293                 fl6->flowi6_oif = daddr->v6.sin6_scope_id;
294         else if (asoc)
295                 fl6->flowi6_oif = asoc->base.sk->sk_bound_dev_if;
296         if (t->flowlabel & SCTP_FLOWLABEL_SET_MASK)
297                 fl6->flowlabel = htonl(t->flowlabel & SCTP_FLOWLABEL_VAL_MASK);
298
299         if (inet6_test_bit(SNDFLOW, sk) &&
300             (fl6->flowlabel & IPV6_FLOWLABEL_MASK)) {
301                 struct ip6_flowlabel *flowlabel;
302
303                 flowlabel = fl6_sock_lookup(sk, fl6->flowlabel);
304                 if (IS_ERR(flowlabel))
305                         goto out;
306                 fl6_sock_release(flowlabel);
307         }
308
309         pr_debug("%s: dst=%pI6 ", __func__, &fl6->daddr);
310
311         if (asoc)
312                 fl6->fl6_sport = htons(asoc->base.bind_addr.port);
313
314         if (saddr) {
315                 fl6->saddr = saddr->v6.sin6_addr;
316                 if (!fl6->fl6_sport)
317                         fl6->fl6_sport = saddr->v6.sin6_port;
318
319                 pr_debug("src=%pI6 - ", &fl6->saddr);
320         }
321
322         rcu_read_lock();
323         final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
324         rcu_read_unlock();
325
326         dst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p);
327         if (!asoc || saddr) {
328                 t->dst = dst;
329                 memcpy(fl, &_fl, sizeof(_fl));
330                 goto out;
331         }
332
333         bp = &asoc->base.bind_addr;
334         scope = sctp_scope(daddr);
335         /* ip6_dst_lookup has filled in the fl6->saddr for us.  Check
336          * to see if we can use it.
337          */
338         if (!IS_ERR(dst)) {
339                 /* Walk through the bind address list and look for a bind
340                  * address that matches the source address of the returned dst.
341                  */
342                 sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port));
343                 rcu_read_lock();
344                 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
345                         if (!laddr->valid || laddr->state == SCTP_ADDR_DEL ||
346                             (laddr->state != SCTP_ADDR_SRC &&
347                              !asoc->src_out_of_asoc_ok))
348                                 continue;
349
350                         /* Do not compare against v4 addrs */
351                         if ((laddr->a.sa.sa_family == AF_INET6) &&
352                             (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) {
353                                 rcu_read_unlock();
354                                 t->dst = dst;
355                                 memcpy(fl, &_fl, sizeof(_fl));
356                                 goto out;
357                         }
358                 }
359                 rcu_read_unlock();
360                 /* None of the bound addresses match the source address of the
361                  * dst. So release it.
362                  */
363                 dst_release(dst);
364                 dst = NULL;
365         }
366
367         /* Walk through the bind address list and try to get the
368          * best source address for a given destination.
369          */
370         rcu_read_lock();
371         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
372                 struct dst_entry *bdst;
373                 __u8 bmatchlen;
374
375                 if (!laddr->valid ||
376                     laddr->state != SCTP_ADDR_SRC ||
377                     laddr->a.sa.sa_family != AF_INET6 ||
378                     scope > sctp_scope(&laddr->a))
379                         continue;
380
381                 fl6->saddr = laddr->a.v6.sin6_addr;
382                 fl6->fl6_sport = laddr->a.v6.sin6_port;
383                 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
384                 bdst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p);
385
386                 if (IS_ERR(bdst))
387                         continue;
388
389                 if (ipv6_chk_addr(dev_net(bdst->dev),
390                                   &laddr->a.v6.sin6_addr, bdst->dev, 1)) {
391                         if (!IS_ERR_OR_NULL(dst))
392                                 dst_release(dst);
393                         dst = bdst;
394                         t->dst = dst;
395                         memcpy(fl, &_fl, sizeof(_fl));
396                         break;
397                 }
398
399                 bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
400                 if (matchlen > bmatchlen) {
401                         dst_release(bdst);
402                         continue;
403                 }
404
405                 if (!IS_ERR_OR_NULL(dst))
406                         dst_release(dst);
407                 dst = bdst;
408                 matchlen = bmatchlen;
409                 t->dst = dst;
410                 memcpy(fl, &_fl, sizeof(_fl));
411         }
412         rcu_read_unlock();
413
414 out:
415         if (!IS_ERR_OR_NULL(dst)) {
416                 struct rt6_info *rt;
417
418                 rt = (struct rt6_info *)dst;
419                 t->dst_cookie = rt6_get_cookie(rt);
420                 pr_debug("rt6_dst:%pI6/%d rt6_src:%pI6\n",
421                          &rt->rt6i_dst.addr, rt->rt6i_dst.plen,
422                          &fl->u.ip6.saddr);
423         } else {
424                 t->dst = NULL;
425                 pr_debug("no route\n");
426         }
427 }
428
429 /* Returns the number of consecutive initial bits that match in the 2 ipv6
430  * addresses.
431  */
432 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
433                                          union sctp_addr *s2)
434 {
435         return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
436 }
437
438 /* Fills in the source address(saddr) based on the destination address(daddr)
439  * and asoc's bind address list.
440  */
441 static void sctp_v6_get_saddr(struct sctp_sock *sk,
442                               struct sctp_transport *t,
443                               struct flowi *fl)
444 {
445         struct flowi6 *fl6 = &fl->u.ip6;
446         union sctp_addr *saddr = &t->saddr;
447
448         pr_debug("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);
449
450         if (t->dst) {
451                 saddr->v6.sin6_family = AF_INET6;
452                 saddr->v6.sin6_addr = fl6->saddr;
453         }
454 }
455
456 /* Make a copy of all potential local addresses. */
457 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
458                                   struct net_device *dev)
459 {
460         struct inet6_dev *in6_dev;
461         struct inet6_ifaddr *ifp;
462         struct sctp_sockaddr_entry *addr;
463
464         rcu_read_lock();
465         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
466                 rcu_read_unlock();
467                 return;
468         }
469
470         read_lock_bh(&in6_dev->lock);
471         list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
472                 /* Add the address to the local list.  */
473                 addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
474                 if (addr) {
475                         addr->a.v6.sin6_family = AF_INET6;
476                         addr->a.v6.sin6_addr = ifp->addr;
477                         addr->a.v6.sin6_scope_id = dev->ifindex;
478                         addr->valid = 1;
479                         INIT_LIST_HEAD(&addr->list);
480                         list_add_tail(&addr->list, addrlist);
481                 }
482         }
483
484         read_unlock_bh(&in6_dev->lock);
485         rcu_read_unlock();
486 }
487
488 /* Copy over any ip options */
489 static void sctp_v6_copy_ip_options(struct sock *sk, struct sock *newsk)
490 {
491         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
492         struct ipv6_txoptions *opt;
493
494         newnp = inet6_sk(newsk);
495
496         rcu_read_lock();
497         opt = rcu_dereference(np->opt);
498         if (opt) {
499                 opt = ipv6_dup_options(newsk, opt);
500                 if (!opt)
501                         pr_err("%s: Failed to copy ip options\n", __func__);
502         }
503         RCU_INIT_POINTER(newnp->opt, opt);
504         rcu_read_unlock();
505 }
506
507 /* Account for the IP options */
508 static int sctp_v6_ip_options_len(struct sock *sk)
509 {
510         struct ipv6_pinfo *np = inet6_sk(sk);
511         struct ipv6_txoptions *opt;
512         int len = 0;
513
514         rcu_read_lock();
515         opt = rcu_dereference(np->opt);
516         if (opt)
517                 len = opt->opt_flen + opt->opt_nflen;
518
519         rcu_read_unlock();
520         return len;
521 }
522
523 /* Initialize a sockaddr_storage from in incoming skb. */
524 static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb,
525                              int is_saddr)
526 {
527         /* Always called on head skb, so this is safe */
528         struct sctphdr *sh = sctp_hdr(skb);
529         struct sockaddr_in6 *sa = &addr->v6;
530
531         addr->v6.sin6_family = AF_INET6;
532         addr->v6.sin6_flowinfo = 0; /* FIXME */
533         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
534
535         if (is_saddr) {
536                 sa->sin6_port = sh->source;
537                 sa->sin6_addr = ipv6_hdr(skb)->saddr;
538         } else {
539                 sa->sin6_port = sh->dest;
540                 sa->sin6_addr = ipv6_hdr(skb)->daddr;
541         }
542 }
543
544 /* Initialize an sctp_addr from a socket. */
545 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
546 {
547         addr->v6.sin6_family = AF_INET6;
548         addr->v6.sin6_port = 0;
549         addr->v6.sin6_addr = sk->sk_v6_rcv_saddr;
550 }
551
552 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
553 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
554 {
555         if (addr->sa.sa_family == AF_INET) {
556                 sk->sk_v6_rcv_saddr.s6_addr32[0] = 0;
557                 sk->sk_v6_rcv_saddr.s6_addr32[1] = 0;
558                 sk->sk_v6_rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
559                 sk->sk_v6_rcv_saddr.s6_addr32[3] =
560                         addr->v4.sin_addr.s_addr;
561         } else {
562                 sk->sk_v6_rcv_saddr = addr->v6.sin6_addr;
563         }
564 }
565
566 /* Initialize sk->sk_daddr from sctp_addr. */
567 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
568 {
569         if (addr->sa.sa_family == AF_INET) {
570                 sk->sk_v6_daddr.s6_addr32[0] = 0;
571                 sk->sk_v6_daddr.s6_addr32[1] = 0;
572                 sk->sk_v6_daddr.s6_addr32[2] = htonl(0x0000ffff);
573                 sk->sk_v6_daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
574         } else {
575                 sk->sk_v6_daddr = addr->v6.sin6_addr;
576         }
577 }
578
579 /* Initialize a sctp_addr from an address parameter. */
580 static bool sctp_v6_from_addr_param(union sctp_addr *addr,
581                                     union sctp_addr_param *param,
582                                     __be16 port, int iif)
583 {
584         if (ntohs(param->v6.param_hdr.length) < sizeof(struct sctp_ipv6addr_param))
585                 return false;
586
587         addr->v6.sin6_family = AF_INET6;
588         addr->v6.sin6_port = port;
589         addr->v6.sin6_flowinfo = 0; /* BUG */
590         addr->v6.sin6_addr = param->v6.addr;
591         addr->v6.sin6_scope_id = iif;
592
593         return true;
594 }
595
596 /* Initialize an address parameter from a sctp_addr and return the length
597  * of the address parameter.
598  */
599 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
600                                  union sctp_addr_param *param)
601 {
602         int length = sizeof(struct sctp_ipv6addr_param);
603
604         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
605         param->v6.param_hdr.length = htons(length);
606         param->v6.addr = addr->v6.sin6_addr;
607
608         return length;
609 }
610
611 /* Initialize a sctp_addr from struct in6_addr. */
612 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
613                               __be16 port)
614 {
615         addr->sa.sa_family = AF_INET6;
616         addr->v6.sin6_port = port;
617         addr->v6.sin6_flowinfo = 0;
618         addr->v6.sin6_addr = *saddr;
619         addr->v6.sin6_scope_id = 0;
620 }
621
622 static int __sctp_v6_cmp_addr(const union sctp_addr *addr1,
623                               const union sctp_addr *addr2)
624 {
625         if (addr1->sa.sa_family != addr2->sa.sa_family) {
626                 if (addr1->sa.sa_family == AF_INET &&
627                     addr2->sa.sa_family == AF_INET6 &&
628                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr) &&
629                     addr2->v6.sin6_addr.s6_addr32[3] ==
630                     addr1->v4.sin_addr.s_addr)
631                         return 1;
632
633                 if (addr2->sa.sa_family == AF_INET &&
634                     addr1->sa.sa_family == AF_INET6 &&
635                     ipv6_addr_v4mapped(&addr1->v6.sin6_addr) &&
636                     addr1->v6.sin6_addr.s6_addr32[3] ==
637                     addr2->v4.sin_addr.s_addr)
638                         return 1;
639
640                 return 0;
641         }
642
643         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
644                 return 0;
645
646         /* If this is a linklocal address, compare the scope_id. */
647         if ((ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) &&
648             addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
649             addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)
650                 return 0;
651
652         return 1;
653 }
654
655 /* Compare addresses exactly.
656  * v4-mapped-v6 is also in consideration.
657  */
658 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
659                             const union sctp_addr *addr2)
660 {
661         return __sctp_v6_cmp_addr(addr1, addr2) &&
662                addr1->v6.sin6_port == addr2->v6.sin6_port;
663 }
664
665 /* Initialize addr struct to INADDR_ANY. */
666 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
667 {
668         memset(addr, 0x00, sizeof(union sctp_addr));
669         addr->v6.sin6_family = AF_INET6;
670         addr->v6.sin6_port = port;
671 }
672
673 /* Is this a wildcard address? */
674 static int sctp_v6_is_any(const union sctp_addr *addr)
675 {
676         return ipv6_addr_any(&addr->v6.sin6_addr);
677 }
678
679 /* Should this be available for binding?   */
680 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
681 {
682         const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
683         struct sock *sk = &sp->inet.sk;
684         struct net *net = sock_net(sk);
685         struct net_device *dev = NULL;
686         int type;
687
688         type = ipv6_addr_type(in6);
689         if (IPV6_ADDR_ANY == type)
690                 return 1;
691         if (type == IPV6_ADDR_MAPPED) {
692                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
693                         return 0;
694                 sctp_v6_map_v4(addr);
695                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
696         }
697         if (!(type & IPV6_ADDR_UNICAST))
698                 return 0;
699
700         if (sk->sk_bound_dev_if) {
701                 dev = dev_get_by_index_rcu(net, sk->sk_bound_dev_if);
702                 if (!dev)
703                         return 0;
704         }
705
706         return ipv6_can_nonlocal_bind(net, &sp->inet) ||
707                ipv6_chk_addr(net, in6, dev, 0);
708 }
709
710 /* This function checks if the address is a valid address to be used for
711  * SCTP.
712  *
713  * Output:
714  * Return 0 - If the address is a non-unicast or an illegal address.
715  * Return 1 - If the address is a unicast.
716  */
717 static int sctp_v6_addr_valid(union sctp_addr *addr,
718                               struct sctp_sock *sp,
719                               const struct sk_buff *skb)
720 {
721         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
722
723         /* Support v4-mapped-v6 address. */
724         if (ret == IPV6_ADDR_MAPPED) {
725                 /* Note: This routine is used in input, so v4-mapped-v6
726                  * are disallowed here when there is no sctp_sock.
727                  */
728                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
729                         return 0;
730                 sctp_v6_map_v4(addr);
731                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
732         }
733
734         /* Is this a non-unicast address */
735         if (!(ret & IPV6_ADDR_UNICAST))
736                 return 0;
737
738         return 1;
739 }
740
741 /* What is the scope of 'addr'?  */
742 static enum sctp_scope sctp_v6_scope(union sctp_addr *addr)
743 {
744         enum sctp_scope retval;
745         int v6scope;
746
747         /* The IPv6 scope is really a set of bit fields.
748          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
749          */
750
751         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
752         switch (v6scope) {
753         case IFA_HOST:
754                 retval = SCTP_SCOPE_LOOPBACK;
755                 break;
756         case IFA_LINK:
757                 retval = SCTP_SCOPE_LINK;
758                 break;
759         case IFA_SITE:
760                 retval = SCTP_SCOPE_PRIVATE;
761                 break;
762         default:
763                 retval = SCTP_SCOPE_GLOBAL;
764                 break;
765         }
766
767         return retval;
768 }
769
770 /* Create and initialize a new sk for the socket to be returned by accept(). */
771 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
772                                              struct sctp_association *asoc,
773                                              bool kern)
774 {
775         struct sock *newsk;
776         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
777         struct sctp6_sock *newsctp6sk;
778
779         newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot, kern);
780         if (!newsk)
781                 goto out;
782
783         sock_init_data(NULL, newsk);
784
785         sctp_copy_sock(newsk, sk, asoc);
786         sock_reset_flag(sk, SOCK_ZAPPED);
787
788         newsctp6sk = (struct sctp6_sock *)newsk;
789         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
790
791         sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
792
793         newnp = inet6_sk(newsk);
794
795         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
796         newnp->ipv6_mc_list = NULL;
797         newnp->ipv6_ac_list = NULL;
798         newnp->ipv6_fl_list = NULL;
799
800         sctp_v6_copy_ip_options(sk, newsk);
801
802         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
803          * and getpeername().
804          */
805         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
806
807         newsk->sk_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
808
809         if (newsk->sk_prot->init(newsk)) {
810                 sk_common_release(newsk);
811                 newsk = NULL;
812         }
813
814 out:
815         return newsk;
816 }
817
818 /* Format a sockaddr for return to user space. This makes sure the return is
819  * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option.
820  */
821 static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr)
822 {
823         if (sp->v4mapped) {
824                 if (addr->sa.sa_family == AF_INET)
825                         sctp_v4_map_v6(addr);
826         } else {
827                 if (addr->sa.sa_family == AF_INET6 &&
828                     ipv6_addr_v4mapped(&addr->v6.sin6_addr))
829                         sctp_v6_map_v4(addr);
830         }
831
832         if (addr->sa.sa_family == AF_INET) {
833                 memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
834                 return sizeof(struct sockaddr_in);
835         }
836         return sizeof(struct sockaddr_in6);
837 }
838
839 /* Where did this skb come from?  */
840 static int sctp_v6_skb_iif(const struct sk_buff *skb)
841 {
842         return inet6_iif(skb);
843 }
844
845 static int sctp_v6_skb_sdif(const struct sk_buff *skb)
846 {
847         return inet6_sdif(skb);
848 }
849
850 /* Was this packet marked by Explicit Congestion Notification? */
851 static int sctp_v6_is_ce(const struct sk_buff *skb)
852 {
853         return *((__u32 *)(ipv6_hdr(skb))) & (__force __u32)htonl(1 << 20);
854 }
855
856 /* Dump the v6 addr to the seq file. */
857 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
858 {
859         seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
860 }
861
862 static void sctp_v6_ecn_capable(struct sock *sk)
863 {
864         inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
865 }
866
867 /* Initialize a PF_INET msgname from a ulpevent. */
868 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
869                                      char *msgname, int *addrlen)
870 {
871         union sctp_addr *addr;
872         struct sctp_association *asoc;
873         union sctp_addr *paddr;
874
875         if (!msgname)
876                 return;
877
878         addr = (union sctp_addr *)msgname;
879         asoc = event->asoc;
880         paddr = &asoc->peer.primary_addr;
881
882         if (paddr->sa.sa_family == AF_INET) {
883                 addr->v4.sin_family = AF_INET;
884                 addr->v4.sin_port = htons(asoc->peer.port);
885                 addr->v4.sin_addr = paddr->v4.sin_addr;
886         } else {
887                 addr->v6.sin6_family = AF_INET6;
888                 addr->v6.sin6_flowinfo = 0;
889                 if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
890                         addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id;
891                 else
892                         addr->v6.sin6_scope_id = 0;
893                 addr->v6.sin6_port = htons(asoc->peer.port);
894                 addr->v6.sin6_addr = paddr->v6.sin6_addr;
895         }
896
897         *addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr);
898 }
899
900 /* Initialize a msg_name from an inbound skb. */
901 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
902                                    int *addr_len)
903 {
904         union sctp_addr *addr;
905         struct sctphdr *sh;
906
907         if (!msgname)
908                 return;
909
910         addr = (union sctp_addr *)msgname;
911         sh = sctp_hdr(skb);
912
913         if (ip_hdr(skb)->version == 4) {
914                 addr->v4.sin_family = AF_INET;
915                 addr->v4.sin_port = sh->source;
916                 addr->v4.sin_addr.s_addr = ip_hdr(skb)->saddr;
917         } else {
918                 addr->v6.sin6_family = AF_INET6;
919                 addr->v6.sin6_flowinfo = 0;
920                 addr->v6.sin6_port = sh->source;
921                 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
922                 if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
923                         addr->v6.sin6_scope_id = sctp_v6_skb_iif(skb);
924                 else
925                         addr->v6.sin6_scope_id = 0;
926         }
927
928         *addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr);
929 }
930
931 /* Do we support this AF? */
932 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
933 {
934         switch (family) {
935         case AF_INET6:
936                 return 1;
937         /* v4-mapped-v6 addresses */
938         case AF_INET:
939                 if (!ipv6_only_sock(sctp_opt2sk(sp)))
940                         return 1;
941                 fallthrough;
942         default:
943                 return 0;
944         }
945 }
946
947 /* Address matching with wildcards allowed.  This extra level
948  * of indirection lets us choose whether a PF_INET6 should
949  * disallow any v4 addresses if we so choose.
950  */
951 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
952                                const union sctp_addr *addr2,
953                                struct sctp_sock *opt)
954 {
955         struct sock *sk = sctp_opt2sk(opt);
956         struct sctp_af *af1, *af2;
957
958         af1 = sctp_get_af_specific(addr1->sa.sa_family);
959         af2 = sctp_get_af_specific(addr2->sa.sa_family);
960
961         if (!af1 || !af2)
962                 return 0;
963
964         /* If the socket is IPv6 only, v4 addrs will not match */
965         if (ipv6_only_sock(sk) && af1 != af2)
966                 return 0;
967
968         /* Today, wildcard AF_INET/AF_INET6. */
969         if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
970                 return 1;
971
972         if (addr1->sa.sa_family == AF_INET && addr2->sa.sa_family == AF_INET)
973                 return addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr;
974
975         return __sctp_v6_cmp_addr(addr1, addr2);
976 }
977
978 /* Verify that the provided sockaddr looks bindable.   Common verification,
979  * has already been taken care of.
980  */
981 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
982 {
983         struct sctp_af *af;
984
985         /* ASSERT: address family has already been verified. */
986         if (addr->sa.sa_family != AF_INET6)
987                 af = sctp_get_af_specific(addr->sa.sa_family);
988         else {
989                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
990                 struct net_device *dev;
991
992                 if (type & IPV6_ADDR_LINKLOCAL) {
993                         struct net *net;
994                         if (!addr->v6.sin6_scope_id)
995                                 return 0;
996                         net = sock_net(&opt->inet.sk);
997                         rcu_read_lock();
998                         dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id);
999                         if (!dev || !(ipv6_can_nonlocal_bind(net, &opt->inet) ||
1000                                       ipv6_chk_addr(net, &addr->v6.sin6_addr,
1001                                                     dev, 0))) {
1002                                 rcu_read_unlock();
1003                                 return 0;
1004                         }
1005                         rcu_read_unlock();
1006                 }
1007
1008                 af = opt->pf->af;
1009         }
1010         return af->available(addr, opt);
1011 }
1012
1013 /* Verify that the provided sockaddr looks sendable.   Common verification,
1014  * has already been taken care of.
1015  */
1016 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
1017 {
1018         struct sctp_af *af = NULL;
1019
1020         /* ASSERT: address family has already been verified. */
1021         if (addr->sa.sa_family != AF_INET6)
1022                 af = sctp_get_af_specific(addr->sa.sa_family);
1023         else {
1024                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
1025                 struct net_device *dev;
1026
1027                 if (type & IPV6_ADDR_LINKLOCAL) {
1028                         if (!addr->v6.sin6_scope_id)
1029                                 return 0;
1030                         rcu_read_lock();
1031                         dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk),
1032                                                    addr->v6.sin6_scope_id);
1033                         rcu_read_unlock();
1034                         if (!dev)
1035                                 return 0;
1036                 }
1037                 af = opt->pf->af;
1038         }
1039
1040         return af != NULL;
1041 }
1042
1043 /* Fill in Supported Address Type information for INIT and INIT-ACK
1044  * chunks.   Note: In the future, we may want to look at sock options
1045  * to determine whether a PF_INET6 socket really wants to have IPV4
1046  * addresses.
1047  * Returns number of addresses supported.
1048  */
1049 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
1050                                       __be16 *types)
1051 {
1052         types[0] = SCTP_PARAM_IPV6_ADDRESS;
1053         if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
1054                 types[1] = SCTP_PARAM_IPV4_ADDRESS;
1055                 return 2;
1056         }
1057         return 1;
1058 }
1059
1060 /* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */
1061 static int sctp_getname(struct socket *sock, struct sockaddr *uaddr,
1062                         int peer)
1063 {
1064         int rc;
1065
1066         rc = inet6_getname(sock, uaddr, peer);
1067
1068         if (rc < 0)
1069                 return rc;
1070
1071         rc = sctp_v6_addr_to_user(sctp_sk(sock->sk),
1072                                           (union sctp_addr *)uaddr);
1073
1074         return rc;
1075 }
1076
1077 static const struct proto_ops inet6_seqpacket_ops = {
1078         .family            = PF_INET6,
1079         .owner             = THIS_MODULE,
1080         .release           = inet6_release,
1081         .bind              = inet6_bind,
1082         .connect           = sctp_inet_connect,
1083         .socketpair        = sock_no_socketpair,
1084         .accept            = inet_accept,
1085         .getname           = sctp_getname,
1086         .poll              = sctp_poll,
1087         .ioctl             = inet6_ioctl,
1088         .gettstamp         = sock_gettstamp,
1089         .listen            = sctp_inet_listen,
1090         .shutdown          = inet_shutdown,
1091         .setsockopt        = sock_common_setsockopt,
1092         .getsockopt        = sock_common_getsockopt,
1093         .sendmsg           = inet_sendmsg,
1094         .recvmsg           = inet_recvmsg,
1095         .mmap              = sock_no_mmap,
1096 #ifdef CONFIG_COMPAT
1097         .compat_ioctl      = inet6_compat_ioctl,
1098 #endif
1099 };
1100
1101 static struct inet_protosw sctpv6_seqpacket_protosw = {
1102         .type          = SOCK_SEQPACKET,
1103         .protocol      = IPPROTO_SCTP,
1104         .prot          = &sctpv6_prot,
1105         .ops           = &inet6_seqpacket_ops,
1106         .flags         = SCTP_PROTOSW_FLAG
1107 };
1108 static struct inet_protosw sctpv6_stream_protosw = {
1109         .type          = SOCK_STREAM,
1110         .protocol      = IPPROTO_SCTP,
1111         .prot          = &sctpv6_prot,
1112         .ops           = &inet6_seqpacket_ops,
1113         .flags         = SCTP_PROTOSW_FLAG,
1114 };
1115
1116 static int sctp6_rcv(struct sk_buff *skb)
1117 {
1118         SCTP_INPUT_CB(skb)->encap_port = 0;
1119         return sctp_rcv(skb) ? -1 : 0;
1120 }
1121
1122 static const struct inet6_protocol sctpv6_protocol = {
1123         .handler      = sctp6_rcv,
1124         .err_handler  = sctp_v6_err,
1125         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
1126 };
1127
1128 static struct sctp_af sctp_af_inet6 = {
1129         .sa_family         = AF_INET6,
1130         .sctp_xmit         = sctp_v6_xmit,
1131         .setsockopt        = ipv6_setsockopt,
1132         .getsockopt        = ipv6_getsockopt,
1133         .get_dst           = sctp_v6_get_dst,
1134         .get_saddr         = sctp_v6_get_saddr,
1135         .copy_addrlist     = sctp_v6_copy_addrlist,
1136         .from_skb          = sctp_v6_from_skb,
1137         .from_sk           = sctp_v6_from_sk,
1138         .from_addr_param   = sctp_v6_from_addr_param,
1139         .to_addr_param     = sctp_v6_to_addr_param,
1140         .cmp_addr          = sctp_v6_cmp_addr,
1141         .scope             = sctp_v6_scope,
1142         .addr_valid        = sctp_v6_addr_valid,
1143         .inaddr_any        = sctp_v6_inaddr_any,
1144         .is_any            = sctp_v6_is_any,
1145         .available         = sctp_v6_available,
1146         .skb_iif           = sctp_v6_skb_iif,
1147         .skb_sdif          = sctp_v6_skb_sdif,
1148         .is_ce             = sctp_v6_is_ce,
1149         .seq_dump_addr     = sctp_v6_seq_dump_addr,
1150         .ecn_capable       = sctp_v6_ecn_capable,
1151         .net_header_len    = sizeof(struct ipv6hdr),
1152         .sockaddr_len      = sizeof(struct sockaddr_in6),
1153         .ip_options_len    = sctp_v6_ip_options_len,
1154 };
1155
1156 static struct sctp_pf sctp_pf_inet6 = {
1157         .event_msgname = sctp_inet6_event_msgname,
1158         .skb_msgname   = sctp_inet6_skb_msgname,
1159         .af_supported  = sctp_inet6_af_supported,
1160         .cmp_addr      = sctp_inet6_cmp_addr,
1161         .bind_verify   = sctp_inet6_bind_verify,
1162         .send_verify   = sctp_inet6_send_verify,
1163         .supported_addrs = sctp_inet6_supported_addrs,
1164         .create_accept_sk = sctp_v6_create_accept_sk,
1165         .addr_to_user  = sctp_v6_addr_to_user,
1166         .to_sk_saddr   = sctp_v6_to_sk_saddr,
1167         .to_sk_daddr   = sctp_v6_to_sk_daddr,
1168         .copy_ip_options = sctp_v6_copy_ip_options,
1169         .af            = &sctp_af_inet6,
1170 };
1171
1172 /* Initialize IPv6 support and register with socket layer.  */
1173 void sctp_v6_pf_init(void)
1174 {
1175         /* Register the SCTP specific PF_INET6 functions. */
1176         sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1177
1178         /* Register the SCTP specific AF_INET6 functions. */
1179         sctp_register_af(&sctp_af_inet6);
1180 }
1181
1182 void sctp_v6_pf_exit(void)
1183 {
1184         list_del(&sctp_af_inet6.list);
1185 }
1186
1187 /* Initialize IPv6 support and register with socket layer.  */
1188 int sctp_v6_protosw_init(void)
1189 {
1190         int rc;
1191
1192         rc = proto_register(&sctpv6_prot, 1);
1193         if (rc)
1194                 return rc;
1195
1196         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1197         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1198         inet6_register_protosw(&sctpv6_stream_protosw);
1199
1200         return 0;
1201 }
1202
1203 void sctp_v6_protosw_exit(void)
1204 {
1205         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1206         inet6_unregister_protosw(&sctpv6_stream_protosw);
1207         proto_unregister(&sctpv6_prot);
1208 }
1209
1210
1211 /* Register with inet6 layer. */
1212 int sctp_v6_add_protocol(void)
1213 {
1214         /* Register notifier for inet6 address additions/deletions. */
1215         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1216
1217         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1218                 return -EAGAIN;
1219
1220         return 0;
1221 }
1222
1223 /* Unregister with inet6 layer. */
1224 void sctp_v6_del_protocol(void)
1225 {
1226         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1227         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1228 }