Merge tag 'block-6.1-2022-11-05' of git://git.kernel.dk/linux
[platform/kernel/linux-starfive.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         struct ipv6_pinfo *np;
132         int err = 0;
133
134         switch (type) {
135         case ICMPV6_PKT_TOOBIG:
136                 if (ip6_sk_accept_pmtu(sk))
137                         sctp_icmp_frag_needed(sk, asoc, t, info);
138                 return;
139         case ICMPV6_PARAMPROB:
140                 if (ICMPV6_UNK_NEXTHDR == code) {
141                         sctp_icmp_proto_unreachable(sk, asoc, t);
142                         return;
143                 }
144                 break;
145         case NDISC_REDIRECT:
146                 sctp_icmp_redirect(sk, t, skb);
147                 return;
148         default:
149                 break;
150         }
151
152         np = inet6_sk(sk);
153         icmpv6_err_convert(type, code, &err);
154         if (!sock_owned_by_user(sk) && np->recverr) {
155                 sk->sk_err = err;
156                 sk_error_report(sk);
157         } else {
158                 sk->sk_err_soft = err;
159         }
160 }
161
162 /* ICMP error handler. */
163 static int sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
164                        u8 type, u8 code, int offset, __be32 info)
165 {
166         struct net *net = dev_net(skb->dev);
167         struct sctp_transport *transport;
168         struct sctp_association *asoc;
169         __u16 saveip, savesctp;
170         struct sock *sk;
171
172         /* Fix up skb to look at the embedded net header. */
173         saveip   = skb->network_header;
174         savesctp = skb->transport_header;
175         skb_reset_network_header(skb);
176         skb_set_transport_header(skb, offset);
177         sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
178         /* Put back, the original pointers. */
179         skb->network_header   = saveip;
180         skb->transport_header = savesctp;
181         if (!sk) {
182                 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS);
183                 return -ENOENT;
184         }
185
186         sctp_v6_err_handle(transport, skb, type, code, ntohl(info));
187         sctp_err_finish(sk, transport);
188
189         return 0;
190 }
191
192 int sctp_udp_v6_err(struct sock *sk, struct sk_buff *skb)
193 {
194         struct net *net = dev_net(skb->dev);
195         struct sctp_association *asoc;
196         struct sctp_transport *t;
197         struct icmp6hdr *hdr;
198         __u32 info = 0;
199
200         skb->transport_header += sizeof(struct udphdr);
201         sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &t);
202         if (!sk) {
203                 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS);
204                 return -ENOENT;
205         }
206
207         skb->transport_header -= sizeof(struct udphdr);
208         hdr = (struct icmp6hdr *)(skb_network_header(skb) - sizeof(struct icmp6hdr));
209         if (hdr->icmp6_type == NDISC_REDIRECT) {
210                 /* can't be handled without outer ip6hdr known, leave it to udpv6_err */
211                 sctp_err_finish(sk, t);
212                 return 0;
213         }
214         if (hdr->icmp6_type == ICMPV6_PKT_TOOBIG)
215                 info = ntohl(hdr->icmp6_mtu);
216         sctp_v6_err_handle(t, skb, hdr->icmp6_type, hdr->icmp6_code, info);
217
218         sctp_err_finish(sk, t);
219         return 1;
220 }
221
222 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *t)
223 {
224         struct dst_entry *dst = dst_clone(t->dst);
225         struct flowi6 *fl6 = &t->fl.u.ip6;
226         struct sock *sk = skb->sk;
227         struct ipv6_pinfo *np = inet6_sk(sk);
228         __u8 tclass = np->tclass;
229         __be32 label;
230
231         pr_debug("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n", __func__, skb,
232                  skb->len, &fl6->saddr, &fl6->daddr);
233
234         if (t->dscp & SCTP_DSCP_SET_MASK)
235                 tclass = t->dscp & SCTP_DSCP_VAL_MASK;
236
237         if (INET_ECN_is_capable(tclass))
238                 IP6_ECN_flow_xmit(sk, fl6->flowlabel);
239
240         if (!(t->param_flags & SPP_PMTUD_ENABLE))
241                 skb->ignore_df = 1;
242
243         SCTP_INC_STATS(sock_net(sk), SCTP_MIB_OUTSCTPPACKS);
244
245         if (!t->encap_port || !sctp_sk(sk)->udp_port) {
246                 int res;
247
248                 skb_dst_set(skb, dst);
249                 rcu_read_lock();
250                 res = ip6_xmit(sk, skb, fl6, sk->sk_mark,
251                                rcu_dereference(np->opt),
252                                tclass, sk->sk_priority);
253                 rcu_read_unlock();
254                 return res;
255         }
256
257         if (skb_is_gso(skb))
258                 skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL_CSUM;
259
260         skb->encapsulation = 1;
261         skb_reset_inner_mac_header(skb);
262         skb_reset_inner_transport_header(skb);
263         skb_set_inner_ipproto(skb, IPPROTO_SCTP);
264         label = ip6_make_flowlabel(sock_net(sk), skb, fl6->flowlabel, true, fl6);
265
266         return udp_tunnel6_xmit_skb(dst, sk, skb, NULL, &fl6->saddr,
267                                     &fl6->daddr, tclass, ip6_dst_hoplimit(dst),
268                                     label, sctp_sk(sk)->udp_port, t->encap_port, false);
269 }
270
271 /* Returns the dst cache entry for the given source and destination ip
272  * addresses.
273  */
274 static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
275                             struct flowi *fl, struct sock *sk)
276 {
277         struct sctp_association *asoc = t->asoc;
278         struct dst_entry *dst = NULL;
279         struct flowi _fl;
280         struct flowi6 *fl6 = &_fl.u.ip6;
281         struct sctp_bind_addr *bp;
282         struct ipv6_pinfo *np = inet6_sk(sk);
283         struct sctp_sockaddr_entry *laddr;
284         union sctp_addr *daddr = &t->ipaddr;
285         union sctp_addr dst_saddr;
286         struct in6_addr *final_p, final;
287         enum sctp_scope scope;
288         __u8 matchlen = 0;
289
290         memset(&_fl, 0, sizeof(_fl));
291         fl6->daddr = daddr->v6.sin6_addr;
292         fl6->fl6_dport = daddr->v6.sin6_port;
293         fl6->flowi6_proto = IPPROTO_SCTP;
294         if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
295                 fl6->flowi6_oif = daddr->v6.sin6_scope_id;
296         else if (asoc)
297                 fl6->flowi6_oif = asoc->base.sk->sk_bound_dev_if;
298         if (t->flowlabel & SCTP_FLOWLABEL_SET_MASK)
299                 fl6->flowlabel = htonl(t->flowlabel & SCTP_FLOWLABEL_VAL_MASK);
300
301         if (np->sndflow && (fl6->flowlabel & IPV6_FLOWLABEL_MASK)) {
302                 struct ip6_flowlabel *flowlabel;
303
304                 flowlabel = fl6_sock_lookup(sk, fl6->flowlabel);
305                 if (IS_ERR(flowlabel))
306                         goto out;
307                 fl6_sock_release(flowlabel);
308         }
309
310         pr_debug("%s: dst=%pI6 ", __func__, &fl6->daddr);
311
312         if (asoc)
313                 fl6->fl6_sport = htons(asoc->base.bind_addr.port);
314
315         if (saddr) {
316                 fl6->saddr = saddr->v6.sin6_addr;
317                 if (!fl6->fl6_sport)
318                         fl6->fl6_sport = saddr->v6.sin6_port;
319
320                 pr_debug("src=%pI6 - ", &fl6->saddr);
321         }
322
323         rcu_read_lock();
324         final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
325         rcu_read_unlock();
326
327         dst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p);
328         if (!asoc || saddr) {
329                 t->dst = dst;
330                 memcpy(fl, &_fl, sizeof(_fl));
331                 goto out;
332         }
333
334         bp = &asoc->base.bind_addr;
335         scope = sctp_scope(daddr);
336         /* ip6_dst_lookup has filled in the fl6->saddr for us.  Check
337          * to see if we can use it.
338          */
339         if (!IS_ERR(dst)) {
340                 /* Walk through the bind address list and look for a bind
341                  * address that matches the source address of the returned dst.
342                  */
343                 sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port));
344                 rcu_read_lock();
345                 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
346                         if (!laddr->valid || laddr->state == SCTP_ADDR_DEL ||
347                             (laddr->state != SCTP_ADDR_SRC &&
348                              !asoc->src_out_of_asoc_ok))
349                                 continue;
350
351                         /* Do not compare against v4 addrs */
352                         if ((laddr->a.sa.sa_family == AF_INET6) &&
353                             (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) {
354                                 rcu_read_unlock();
355                                 t->dst = dst;
356                                 memcpy(fl, &_fl, sizeof(_fl));
357                                 goto out;
358                         }
359                 }
360                 rcu_read_unlock();
361                 /* None of the bound addresses match the source address of the
362                  * dst. So release it.
363                  */
364                 dst_release(dst);
365                 dst = NULL;
366         }
367
368         /* Walk through the bind address list and try to get the
369          * best source address for a given destination.
370          */
371         rcu_read_lock();
372         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
373                 struct dst_entry *bdst;
374                 __u8 bmatchlen;
375
376                 if (!laddr->valid ||
377                     laddr->state != SCTP_ADDR_SRC ||
378                     laddr->a.sa.sa_family != AF_INET6 ||
379                     scope > sctp_scope(&laddr->a))
380                         continue;
381
382                 fl6->saddr = laddr->a.v6.sin6_addr;
383                 fl6->fl6_sport = laddr->a.v6.sin6_port;
384                 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
385                 bdst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p);
386
387                 if (IS_ERR(bdst))
388                         continue;
389
390                 if (ipv6_chk_addr(dev_net(bdst->dev),
391                                   &laddr->a.v6.sin6_addr, bdst->dev, 1)) {
392                         if (!IS_ERR_OR_NULL(dst))
393                                 dst_release(dst);
394                         dst = bdst;
395                         t->dst = dst;
396                         memcpy(fl, &_fl, sizeof(_fl));
397                         break;
398                 }
399
400                 bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
401                 if (matchlen > bmatchlen) {
402                         dst_release(bdst);
403                         continue;
404                 }
405
406                 if (!IS_ERR_OR_NULL(dst))
407                         dst_release(dst);
408                 dst = bdst;
409                 matchlen = bmatchlen;
410                 t->dst = dst;
411                 memcpy(fl, &_fl, sizeof(_fl));
412         }
413         rcu_read_unlock();
414
415 out:
416         if (!IS_ERR_OR_NULL(dst)) {
417                 struct rt6_info *rt;
418
419                 rt = (struct rt6_info *)dst;
420                 t->dst_cookie = rt6_get_cookie(rt);
421                 pr_debug("rt6_dst:%pI6/%d rt6_src:%pI6\n",
422                          &rt->rt6i_dst.addr, rt->rt6i_dst.plen,
423                          &fl->u.ip6.saddr);
424         } else {
425                 t->dst = NULL;
426                 pr_debug("no route\n");
427         }
428 }
429
430 /* Returns the number of consecutive initial bits that match in the 2 ipv6
431  * addresses.
432  */
433 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
434                                          union sctp_addr *s2)
435 {
436         return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
437 }
438
439 /* Fills in the source address(saddr) based on the destination address(daddr)
440  * and asoc's bind address list.
441  */
442 static void sctp_v6_get_saddr(struct sctp_sock *sk,
443                               struct sctp_transport *t,
444                               struct flowi *fl)
445 {
446         struct flowi6 *fl6 = &fl->u.ip6;
447         union sctp_addr *saddr = &t->saddr;
448
449         pr_debug("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);
450
451         if (t->dst) {
452                 saddr->v6.sin6_family = AF_INET6;
453                 saddr->v6.sin6_addr = fl6->saddr;
454         }
455 }
456
457 /* Make a copy of all potential local addresses. */
458 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
459                                   struct net_device *dev)
460 {
461         struct inet6_dev *in6_dev;
462         struct inet6_ifaddr *ifp;
463         struct sctp_sockaddr_entry *addr;
464
465         rcu_read_lock();
466         if ((in6_dev = __in6_dev_get(dev)) == NULL) {
467                 rcu_read_unlock();
468                 return;
469         }
470
471         read_lock_bh(&in6_dev->lock);
472         list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
473                 /* Add the address to the local list.  */
474                 addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
475                 if (addr) {
476                         addr->a.v6.sin6_family = AF_INET6;
477                         addr->a.v6.sin6_addr = ifp->addr;
478                         addr->a.v6.sin6_scope_id = dev->ifindex;
479                         addr->valid = 1;
480                         INIT_LIST_HEAD(&addr->list);
481                         list_add_tail(&addr->list, addrlist);
482                 }
483         }
484
485         read_unlock_bh(&in6_dev->lock);
486         rcu_read_unlock();
487 }
488
489 /* Copy over any ip options */
490 static void sctp_v6_copy_ip_options(struct sock *sk, struct sock *newsk)
491 {
492         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
493         struct ipv6_txoptions *opt;
494
495         newnp = inet6_sk(newsk);
496
497         rcu_read_lock();
498         opt = rcu_dereference(np->opt);
499         if (opt) {
500                 opt = ipv6_dup_options(newsk, opt);
501                 if (!opt)
502                         pr_err("%s: Failed to copy ip options\n", __func__);
503         }
504         RCU_INIT_POINTER(newnp->opt, opt);
505         rcu_read_unlock();
506 }
507
508 /* Account for the IP options */
509 static int sctp_v6_ip_options_len(struct sock *sk)
510 {
511         struct ipv6_pinfo *np = inet6_sk(sk);
512         struct ipv6_txoptions *opt;
513         int len = 0;
514
515         rcu_read_lock();
516         opt = rcu_dereference(np->opt);
517         if (opt)
518                 len = opt->opt_flen + opt->opt_nflen;
519
520         rcu_read_unlock();
521         return len;
522 }
523
524 /* Initialize a sockaddr_storage from in incoming skb. */
525 static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb,
526                              int is_saddr)
527 {
528         /* Always called on head skb, so this is safe */
529         struct sctphdr *sh = sctp_hdr(skb);
530         struct sockaddr_in6 *sa = &addr->v6;
531
532         addr->v6.sin6_family = AF_INET6;
533         addr->v6.sin6_flowinfo = 0; /* FIXME */
534         addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
535
536         if (is_saddr) {
537                 sa->sin6_port = sh->source;
538                 sa->sin6_addr = ipv6_hdr(skb)->saddr;
539         } else {
540                 sa->sin6_port = sh->dest;
541                 sa->sin6_addr = ipv6_hdr(skb)->daddr;
542         }
543 }
544
545 /* Initialize an sctp_addr from a socket. */
546 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
547 {
548         addr->v6.sin6_family = AF_INET6;
549         addr->v6.sin6_port = 0;
550         addr->v6.sin6_addr = sk->sk_v6_rcv_saddr;
551 }
552
553 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
554 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
555 {
556         if (addr->sa.sa_family == AF_INET) {
557                 sk->sk_v6_rcv_saddr.s6_addr32[0] = 0;
558                 sk->sk_v6_rcv_saddr.s6_addr32[1] = 0;
559                 sk->sk_v6_rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
560                 sk->sk_v6_rcv_saddr.s6_addr32[3] =
561                         addr->v4.sin_addr.s_addr;
562         } else {
563                 sk->sk_v6_rcv_saddr = addr->v6.sin6_addr;
564         }
565 }
566
567 /* Initialize sk->sk_daddr from sctp_addr. */
568 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
569 {
570         if (addr->sa.sa_family == AF_INET) {
571                 sk->sk_v6_daddr.s6_addr32[0] = 0;
572                 sk->sk_v6_daddr.s6_addr32[1] = 0;
573                 sk->sk_v6_daddr.s6_addr32[2] = htonl(0x0000ffff);
574                 sk->sk_v6_daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
575         } else {
576                 sk->sk_v6_daddr = addr->v6.sin6_addr;
577         }
578 }
579
580 /* Initialize a sctp_addr from an address parameter. */
581 static bool sctp_v6_from_addr_param(union sctp_addr *addr,
582                                     union sctp_addr_param *param,
583                                     __be16 port, int iif)
584 {
585         if (ntohs(param->v6.param_hdr.length) < sizeof(struct sctp_ipv6addr_param))
586                 return false;
587
588         addr->v6.sin6_family = AF_INET6;
589         addr->v6.sin6_port = port;
590         addr->v6.sin6_flowinfo = 0; /* BUG */
591         addr->v6.sin6_addr = param->v6.addr;
592         addr->v6.sin6_scope_id = iif;
593
594         return true;
595 }
596
597 /* Initialize an address parameter from a sctp_addr and return the length
598  * of the address parameter.
599  */
600 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
601                                  union sctp_addr_param *param)
602 {
603         int length = sizeof(struct sctp_ipv6addr_param);
604
605         param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
606         param->v6.param_hdr.length = htons(length);
607         param->v6.addr = addr->v6.sin6_addr;
608
609         return length;
610 }
611
612 /* Initialize a sctp_addr from struct in6_addr. */
613 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
614                               __be16 port)
615 {
616         addr->sa.sa_family = AF_INET6;
617         addr->v6.sin6_port = port;
618         addr->v6.sin6_flowinfo = 0;
619         addr->v6.sin6_addr = *saddr;
620         addr->v6.sin6_scope_id = 0;
621 }
622
623 static int __sctp_v6_cmp_addr(const union sctp_addr *addr1,
624                               const union sctp_addr *addr2)
625 {
626         if (addr1->sa.sa_family != addr2->sa.sa_family) {
627                 if (addr1->sa.sa_family == AF_INET &&
628                     addr2->sa.sa_family == AF_INET6 &&
629                     ipv6_addr_v4mapped(&addr2->v6.sin6_addr) &&
630                     addr2->v6.sin6_addr.s6_addr32[3] ==
631                     addr1->v4.sin_addr.s_addr)
632                         return 1;
633
634                 if (addr2->sa.sa_family == AF_INET &&
635                     addr1->sa.sa_family == AF_INET6 &&
636                     ipv6_addr_v4mapped(&addr1->v6.sin6_addr) &&
637                     addr1->v6.sin6_addr.s6_addr32[3] ==
638                     addr2->v4.sin_addr.s_addr)
639                         return 1;
640
641                 return 0;
642         }
643
644         if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
645                 return 0;
646
647         /* If this is a linklocal address, compare the scope_id. */
648         if ((ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) &&
649             addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
650             addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)
651                 return 0;
652
653         return 1;
654 }
655
656 /* Compare addresses exactly.
657  * v4-mapped-v6 is also in consideration.
658  */
659 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
660                             const union sctp_addr *addr2)
661 {
662         return __sctp_v6_cmp_addr(addr1, addr2) &&
663                addr1->v6.sin6_port == addr2->v6.sin6_port;
664 }
665
666 /* Initialize addr struct to INADDR_ANY. */
667 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
668 {
669         memset(addr, 0x00, sizeof(union sctp_addr));
670         addr->v6.sin6_family = AF_INET6;
671         addr->v6.sin6_port = port;
672 }
673
674 /* Is this a wildcard address? */
675 static int sctp_v6_is_any(const union sctp_addr *addr)
676 {
677         return ipv6_addr_any(&addr->v6.sin6_addr);
678 }
679
680 /* Should this be available for binding?   */
681 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
682 {
683         int type;
684         struct net *net = sock_net(&sp->inet.sk);
685         const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
686
687         type = ipv6_addr_type(in6);
688         if (IPV6_ADDR_ANY == type)
689                 return 1;
690         if (type == IPV6_ADDR_MAPPED) {
691                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
692                         return 0;
693                 sctp_v6_map_v4(addr);
694                 return sctp_get_af_specific(AF_INET)->available(addr, sp);
695         }
696         if (!(type & IPV6_ADDR_UNICAST))
697                 return 0;
698
699         return ipv6_can_nonlocal_bind(net, &sp->inet) ||
700                ipv6_chk_addr(net, in6, NULL, 0);
701 }
702
703 /* This function checks if the address is a valid address to be used for
704  * SCTP.
705  *
706  * Output:
707  * Return 0 - If the address is a non-unicast or an illegal address.
708  * Return 1 - If the address is a unicast.
709  */
710 static int sctp_v6_addr_valid(union sctp_addr *addr,
711                               struct sctp_sock *sp,
712                               const struct sk_buff *skb)
713 {
714         int ret = ipv6_addr_type(&addr->v6.sin6_addr);
715
716         /* Support v4-mapped-v6 address. */
717         if (ret == IPV6_ADDR_MAPPED) {
718                 /* Note: This routine is used in input, so v4-mapped-v6
719                  * are disallowed here when there is no sctp_sock.
720                  */
721                 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
722                         return 0;
723                 sctp_v6_map_v4(addr);
724                 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
725         }
726
727         /* Is this a non-unicast address */
728         if (!(ret & IPV6_ADDR_UNICAST))
729                 return 0;
730
731         return 1;
732 }
733
734 /* What is the scope of 'addr'?  */
735 static enum sctp_scope sctp_v6_scope(union sctp_addr *addr)
736 {
737         enum sctp_scope retval;
738         int v6scope;
739
740         /* The IPv6 scope is really a set of bit fields.
741          * See IFA_* in <net/if_inet6.h>.  Map to a generic SCTP scope.
742          */
743
744         v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
745         switch (v6scope) {
746         case IFA_HOST:
747                 retval = SCTP_SCOPE_LOOPBACK;
748                 break;
749         case IFA_LINK:
750                 retval = SCTP_SCOPE_LINK;
751                 break;
752         case IFA_SITE:
753                 retval = SCTP_SCOPE_PRIVATE;
754                 break;
755         default:
756                 retval = SCTP_SCOPE_GLOBAL;
757                 break;
758         }
759
760         return retval;
761 }
762
763 /* Create and initialize a new sk for the socket to be returned by accept(). */
764 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
765                                              struct sctp_association *asoc,
766                                              bool kern)
767 {
768         struct sock *newsk;
769         struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
770         struct sctp6_sock *newsctp6sk;
771
772         newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot, kern);
773         if (!newsk)
774                 goto out;
775
776         sock_init_data(NULL, newsk);
777
778         sctp_copy_sock(newsk, sk, asoc);
779         sock_reset_flag(sk, SOCK_ZAPPED);
780
781         newsctp6sk = (struct sctp6_sock *)newsk;
782         inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
783
784         sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
785
786         newnp = inet6_sk(newsk);
787
788         memcpy(newnp, np, sizeof(struct ipv6_pinfo));
789         newnp->ipv6_mc_list = NULL;
790         newnp->ipv6_ac_list = NULL;
791         newnp->ipv6_fl_list = NULL;
792
793         sctp_v6_copy_ip_options(sk, newsk);
794
795         /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
796          * and getpeername().
797          */
798         sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
799
800         newsk->sk_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
801
802         sk_refcnt_debug_inc(newsk);
803
804         if (newsk->sk_prot->init(newsk)) {
805                 sk_common_release(newsk);
806                 newsk = NULL;
807         }
808
809 out:
810         return newsk;
811 }
812
813 /* Format a sockaddr for return to user space. This makes sure the return is
814  * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option.
815  */
816 static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr)
817 {
818         if (sp->v4mapped) {
819                 if (addr->sa.sa_family == AF_INET)
820                         sctp_v4_map_v6(addr);
821         } else {
822                 if (addr->sa.sa_family == AF_INET6 &&
823                     ipv6_addr_v4mapped(&addr->v6.sin6_addr))
824                         sctp_v6_map_v4(addr);
825         }
826
827         if (addr->sa.sa_family == AF_INET) {
828                 memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
829                 return sizeof(struct sockaddr_in);
830         }
831         return sizeof(struct sockaddr_in6);
832 }
833
834 /* Where did this skb come from?  */
835 static int sctp_v6_skb_iif(const struct sk_buff *skb)
836 {
837         return IP6CB(skb)->iif;
838 }
839
840 /* Was this packet marked by Explicit Congestion Notification? */
841 static int sctp_v6_is_ce(const struct sk_buff *skb)
842 {
843         return *((__u32 *)(ipv6_hdr(skb))) & (__force __u32)htonl(1 << 20);
844 }
845
846 /* Dump the v6 addr to the seq file. */
847 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
848 {
849         seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
850 }
851
852 static void sctp_v6_ecn_capable(struct sock *sk)
853 {
854         inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
855 }
856
857 /* Initialize a PF_INET msgname from a ulpevent. */
858 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
859                                      char *msgname, int *addrlen)
860 {
861         union sctp_addr *addr;
862         struct sctp_association *asoc;
863         union sctp_addr *paddr;
864
865         if (!msgname)
866                 return;
867
868         addr = (union sctp_addr *)msgname;
869         asoc = event->asoc;
870         paddr = &asoc->peer.primary_addr;
871
872         if (paddr->sa.sa_family == AF_INET) {
873                 addr->v4.sin_family = AF_INET;
874                 addr->v4.sin_port = htons(asoc->peer.port);
875                 addr->v4.sin_addr = paddr->v4.sin_addr;
876         } else {
877                 addr->v6.sin6_family = AF_INET6;
878                 addr->v6.sin6_flowinfo = 0;
879                 if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
880                         addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id;
881                 else
882                         addr->v6.sin6_scope_id = 0;
883                 addr->v6.sin6_port = htons(asoc->peer.port);
884                 addr->v6.sin6_addr = paddr->v6.sin6_addr;
885         }
886
887         *addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr);
888 }
889
890 /* Initialize a msg_name from an inbound skb. */
891 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
892                                    int *addr_len)
893 {
894         union sctp_addr *addr;
895         struct sctphdr *sh;
896
897         if (!msgname)
898                 return;
899
900         addr = (union sctp_addr *)msgname;
901         sh = sctp_hdr(skb);
902
903         if (ip_hdr(skb)->version == 4) {
904                 addr->v4.sin_family = AF_INET;
905                 addr->v4.sin_port = sh->source;
906                 addr->v4.sin_addr.s_addr = ip_hdr(skb)->saddr;
907         } else {
908                 addr->v6.sin6_family = AF_INET6;
909                 addr->v6.sin6_flowinfo = 0;
910                 addr->v6.sin6_port = sh->source;
911                 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
912                 if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
913                         addr->v6.sin6_scope_id = sctp_v6_skb_iif(skb);
914                 else
915                         addr->v6.sin6_scope_id = 0;
916         }
917
918         *addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr);
919 }
920
921 /* Do we support this AF? */
922 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
923 {
924         switch (family) {
925         case AF_INET6:
926                 return 1;
927         /* v4-mapped-v6 addresses */
928         case AF_INET:
929                 if (!ipv6_only_sock(sctp_opt2sk(sp)))
930                         return 1;
931                 fallthrough;
932         default:
933                 return 0;
934         }
935 }
936
937 /* Address matching with wildcards allowed.  This extra level
938  * of indirection lets us choose whether a PF_INET6 should
939  * disallow any v4 addresses if we so choose.
940  */
941 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
942                                const union sctp_addr *addr2,
943                                struct sctp_sock *opt)
944 {
945         struct sock *sk = sctp_opt2sk(opt);
946         struct sctp_af *af1, *af2;
947
948         af1 = sctp_get_af_specific(addr1->sa.sa_family);
949         af2 = sctp_get_af_specific(addr2->sa.sa_family);
950
951         if (!af1 || !af2)
952                 return 0;
953
954         /* If the socket is IPv6 only, v4 addrs will not match */
955         if (ipv6_only_sock(sk) && af1 != af2)
956                 return 0;
957
958         /* Today, wildcard AF_INET/AF_INET6. */
959         if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
960                 return 1;
961
962         if (addr1->sa.sa_family == AF_INET && addr2->sa.sa_family == AF_INET)
963                 return addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr;
964
965         return __sctp_v6_cmp_addr(addr1, addr2);
966 }
967
968 /* Verify that the provided sockaddr looks bindable.   Common verification,
969  * has already been taken care of.
970  */
971 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
972 {
973         struct sctp_af *af;
974
975         /* ASSERT: address family has already been verified. */
976         if (addr->sa.sa_family != AF_INET6)
977                 af = sctp_get_af_specific(addr->sa.sa_family);
978         else {
979                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
980                 struct net_device *dev;
981
982                 if (type & IPV6_ADDR_LINKLOCAL) {
983                         struct net *net;
984                         if (!addr->v6.sin6_scope_id)
985                                 return 0;
986                         net = sock_net(&opt->inet.sk);
987                         rcu_read_lock();
988                         dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id);
989                         if (!dev || !(ipv6_can_nonlocal_bind(net, &opt->inet) ||
990                                       ipv6_chk_addr(net, &addr->v6.sin6_addr,
991                                                     dev, 0))) {
992                                 rcu_read_unlock();
993                                 return 0;
994                         }
995                         rcu_read_unlock();
996                 }
997
998                 af = opt->pf->af;
999         }
1000         return af->available(addr, opt);
1001 }
1002
1003 /* Verify that the provided sockaddr looks sendable.   Common verification,
1004  * has already been taken care of.
1005  */
1006 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
1007 {
1008         struct sctp_af *af = NULL;
1009
1010         /* ASSERT: address family has already been verified. */
1011         if (addr->sa.sa_family != AF_INET6)
1012                 af = sctp_get_af_specific(addr->sa.sa_family);
1013         else {
1014                 int type = ipv6_addr_type(&addr->v6.sin6_addr);
1015                 struct net_device *dev;
1016
1017                 if (type & IPV6_ADDR_LINKLOCAL) {
1018                         if (!addr->v6.sin6_scope_id)
1019                                 return 0;
1020                         rcu_read_lock();
1021                         dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk),
1022                                                    addr->v6.sin6_scope_id);
1023                         rcu_read_unlock();
1024                         if (!dev)
1025                                 return 0;
1026                 }
1027                 af = opt->pf->af;
1028         }
1029
1030         return af != NULL;
1031 }
1032
1033 /* Fill in Supported Address Type information for INIT and INIT-ACK
1034  * chunks.   Note: In the future, we may want to look at sock options
1035  * to determine whether a PF_INET6 socket really wants to have IPV4
1036  * addresses.
1037  * Returns number of addresses supported.
1038  */
1039 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
1040                                       __be16 *types)
1041 {
1042         types[0] = SCTP_PARAM_IPV6_ADDRESS;
1043         if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
1044                 types[1] = SCTP_PARAM_IPV4_ADDRESS;
1045                 return 2;
1046         }
1047         return 1;
1048 }
1049
1050 /* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */
1051 static int sctp_getname(struct socket *sock, struct sockaddr *uaddr,
1052                         int peer)
1053 {
1054         int rc;
1055
1056         rc = inet6_getname(sock, uaddr, peer);
1057
1058         if (rc < 0)
1059                 return rc;
1060
1061         rc = sctp_v6_addr_to_user(sctp_sk(sock->sk),
1062                                           (union sctp_addr *)uaddr);
1063
1064         return rc;
1065 }
1066
1067 static const struct proto_ops inet6_seqpacket_ops = {
1068         .family            = PF_INET6,
1069         .owner             = THIS_MODULE,
1070         .release           = inet6_release,
1071         .bind              = inet6_bind,
1072         .connect           = sctp_inet_connect,
1073         .socketpair        = sock_no_socketpair,
1074         .accept            = inet_accept,
1075         .getname           = sctp_getname,
1076         .poll              = sctp_poll,
1077         .ioctl             = inet6_ioctl,
1078         .gettstamp         = sock_gettstamp,
1079         .listen            = sctp_inet_listen,
1080         .shutdown          = inet_shutdown,
1081         .setsockopt        = sock_common_setsockopt,
1082         .getsockopt        = sock_common_getsockopt,
1083         .sendmsg           = inet_sendmsg,
1084         .recvmsg           = inet_recvmsg,
1085         .mmap              = sock_no_mmap,
1086 #ifdef CONFIG_COMPAT
1087         .compat_ioctl      = inet6_compat_ioctl,
1088 #endif
1089 };
1090
1091 static struct inet_protosw sctpv6_seqpacket_protosw = {
1092         .type          = SOCK_SEQPACKET,
1093         .protocol      = IPPROTO_SCTP,
1094         .prot          = &sctpv6_prot,
1095         .ops           = &inet6_seqpacket_ops,
1096         .flags         = SCTP_PROTOSW_FLAG
1097 };
1098 static struct inet_protosw sctpv6_stream_protosw = {
1099         .type          = SOCK_STREAM,
1100         .protocol      = IPPROTO_SCTP,
1101         .prot          = &sctpv6_prot,
1102         .ops           = &inet6_seqpacket_ops,
1103         .flags         = SCTP_PROTOSW_FLAG,
1104 };
1105
1106 static int sctp6_rcv(struct sk_buff *skb)
1107 {
1108         SCTP_INPUT_CB(skb)->encap_port = 0;
1109         return sctp_rcv(skb) ? -1 : 0;
1110 }
1111
1112 static const struct inet6_protocol sctpv6_protocol = {
1113         .handler      = sctp6_rcv,
1114         .err_handler  = sctp_v6_err,
1115         .flags        = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
1116 };
1117
1118 static struct sctp_af sctp_af_inet6 = {
1119         .sa_family         = AF_INET6,
1120         .sctp_xmit         = sctp_v6_xmit,
1121         .setsockopt        = ipv6_setsockopt,
1122         .getsockopt        = ipv6_getsockopt,
1123         .get_dst           = sctp_v6_get_dst,
1124         .get_saddr         = sctp_v6_get_saddr,
1125         .copy_addrlist     = sctp_v6_copy_addrlist,
1126         .from_skb          = sctp_v6_from_skb,
1127         .from_sk           = sctp_v6_from_sk,
1128         .from_addr_param   = sctp_v6_from_addr_param,
1129         .to_addr_param     = sctp_v6_to_addr_param,
1130         .cmp_addr          = sctp_v6_cmp_addr,
1131         .scope             = sctp_v6_scope,
1132         .addr_valid        = sctp_v6_addr_valid,
1133         .inaddr_any        = sctp_v6_inaddr_any,
1134         .is_any            = sctp_v6_is_any,
1135         .available         = sctp_v6_available,
1136         .skb_iif           = sctp_v6_skb_iif,
1137         .is_ce             = sctp_v6_is_ce,
1138         .seq_dump_addr     = sctp_v6_seq_dump_addr,
1139         .ecn_capable       = sctp_v6_ecn_capable,
1140         .net_header_len    = sizeof(struct ipv6hdr),
1141         .sockaddr_len      = sizeof(struct sockaddr_in6),
1142         .ip_options_len    = sctp_v6_ip_options_len,
1143 };
1144
1145 static struct sctp_pf sctp_pf_inet6 = {
1146         .event_msgname = sctp_inet6_event_msgname,
1147         .skb_msgname   = sctp_inet6_skb_msgname,
1148         .af_supported  = sctp_inet6_af_supported,
1149         .cmp_addr      = sctp_inet6_cmp_addr,
1150         .bind_verify   = sctp_inet6_bind_verify,
1151         .send_verify   = sctp_inet6_send_verify,
1152         .supported_addrs = sctp_inet6_supported_addrs,
1153         .create_accept_sk = sctp_v6_create_accept_sk,
1154         .addr_to_user  = sctp_v6_addr_to_user,
1155         .to_sk_saddr   = sctp_v6_to_sk_saddr,
1156         .to_sk_daddr   = sctp_v6_to_sk_daddr,
1157         .copy_ip_options = sctp_v6_copy_ip_options,
1158         .af            = &sctp_af_inet6,
1159 };
1160
1161 /* Initialize IPv6 support and register with socket layer.  */
1162 void sctp_v6_pf_init(void)
1163 {
1164         /* Register the SCTP specific PF_INET6 functions. */
1165         sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1166
1167         /* Register the SCTP specific AF_INET6 functions. */
1168         sctp_register_af(&sctp_af_inet6);
1169 }
1170
1171 void sctp_v6_pf_exit(void)
1172 {
1173         list_del(&sctp_af_inet6.list);
1174 }
1175
1176 /* Initialize IPv6 support and register with socket layer.  */
1177 int sctp_v6_protosw_init(void)
1178 {
1179         int rc;
1180
1181         rc = proto_register(&sctpv6_prot, 1);
1182         if (rc)
1183                 return rc;
1184
1185         /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1186         inet6_register_protosw(&sctpv6_seqpacket_protosw);
1187         inet6_register_protosw(&sctpv6_stream_protosw);
1188
1189         return 0;
1190 }
1191
1192 void sctp_v6_protosw_exit(void)
1193 {
1194         inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1195         inet6_unregister_protosw(&sctpv6_stream_protosw);
1196         proto_unregister(&sctpv6_prot);
1197 }
1198
1199
1200 /* Register with inet6 layer. */
1201 int sctp_v6_add_protocol(void)
1202 {
1203         /* Register notifier for inet6 address additions/deletions. */
1204         register_inet6addr_notifier(&sctp_inet6addr_notifier);
1205
1206         if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1207                 return -EAGAIN;
1208
1209         return 0;
1210 }
1211
1212 /* Unregister with inet6 layer. */
1213 void sctp_v6_del_protocol(void)
1214 {
1215         inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1216         unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1217 }