1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* SCTP kernel implementation
3 * (C) Copyright IBM Corp. 2002, 2004
4 * Copyright (c) 2001 Nokia, Inc.
5 * Copyright (c) 2001 La Monte H.P. Yarroll
6 * Copyright (c) 2002-2003 Intel Corp.
7 *
8 * This file is part of the SCTP kernel implementation
9 *
10 * SCTP over IPv6.
11 *
12 * Please send any bug reports or fixes you make to the
13 * email address(es):
14 * lksctp developers <linux-sctp@vger.kernel.org>
15 *
16 * Written or modified by:
17 * Le Yanqun <yanqun.le@nokia.com>
18 * Hui Huang <hui.huang@nokia.com>
19 * La Monte H.P. Yarroll <piggy@acm.org>
20 * Sridhar Samudrala <sri@us.ibm.com>
21 * Jon Grimm <jgrimm@us.ibm.com>
22 * Ardelle Fan <ardelle.fan@intel.com>
23 *
24 * Based on:
25 * linux/net/ipv6/tcp_ipv6.c
26 */
27
28 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
29
30 #include <linux/module.h>
31 #include <linux/errno.h>
32 #include <linux/types.h>
33 #include <linux/socket.h>
34 #include <linux/sockios.h>
35 #include <linux/net.h>
36 #include <linux/in.h>
37 #include <linux/in6.h>
38 #include <linux/netdevice.h>
39 #include <linux/init.h>
40 #include <linux/ipsec.h>
41 #include <linux/slab.h>
42
43 #include <linux/ipv6.h>
44 #include <linux/icmpv6.h>
45 #include <linux/random.h>
46 #include <linux/seq_file.h>
47
48 #include <net/protocol.h>
49 #include <net/ndisc.h>
50 #include <net/ip.h>
51 #include <net/ipv6.h>
52 #include <net/transp_v6.h>
53 #include <net/addrconf.h>
54 #include <net/ip6_route.h>
55 #include <net/inet_common.h>
56 #include <net/inet_ecn.h>
57 #include <net/sctp/sctp.h>
58
59 #include <linux/uaccess.h>
60
61 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
62 union sctp_addr *s2);
63 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
64 __be16 port);
65 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
66 const union sctp_addr *addr2);
67
68 /* Event handler for inet6 address addition/deletion events.
69 * The sctp_local_addr_list needs to be protocted by a spin lock since
70 * multiple notifiers (say IPv4 and IPv6) may be running at the same
71 * time and thus corrupt the list.
72 * The reader side is protected with RCU.
73 */
sctp_inet6addr_event(struct notifier_block * this,unsigned long ev,void * ptr)74 static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev,
75 void *ptr)
76 {
77 struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
78 struct sctp_sockaddr_entry *addr = NULL;
79 struct sctp_sockaddr_entry *temp;
80 struct net *net = dev_net(ifa->idev->dev);
81 int found = 0;
82
83 switch (ev) {
84 case NETDEV_UP:
85 addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
86 if (addr) {
87 addr->a.v6.sin6_family = AF_INET6;
88 addr->a.v6.sin6_addr = ifa->addr;
89 addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
90 addr->valid = 1;
91 spin_lock_bh(&net->sctp.local_addr_lock);
92 list_add_tail_rcu(&addr->list, &net->sctp.local_addr_list);
93 sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_NEW);
94 spin_unlock_bh(&net->sctp.local_addr_lock);
95 }
96 break;
97 case NETDEV_DOWN:
98 spin_lock_bh(&net->sctp.local_addr_lock);
99 list_for_each_entry_safe(addr, temp,
100 &net->sctp.local_addr_list, list) {
101 if (addr->a.sa.sa_family == AF_INET6 &&
102 ipv6_addr_equal(&addr->a.v6.sin6_addr,
103 &ifa->addr)) {
104 sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL);
105 found = 1;
106 addr->valid = 0;
107 list_del_rcu(&addr->list);
108 break;
109 }
110 }
111 spin_unlock_bh(&net->sctp.local_addr_lock);
112 if (found)
113 kfree_rcu(addr, rcu);
114 break;
115 }
116
117 return NOTIFY_DONE;
118 }
119
120 static struct notifier_block sctp_inet6addr_notifier = {
121 .notifier_call = sctp_inet6addr_event,
122 };
123
124 /* ICMP error handler. */
sctp_v6_err(struct sk_buff * skb,struct inet6_skb_parm * opt,u8 type,u8 code,int offset,__be32 info)125 static int sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
126 u8 type, u8 code, int offset, __be32 info)
127 {
128 struct inet6_dev *idev;
129 struct sock *sk;
130 struct sctp_association *asoc;
131 struct sctp_transport *transport;
132 struct ipv6_pinfo *np;
133 __u16 saveip, savesctp;
134 int err, ret = 0;
135 struct net *net = dev_net(skb->dev);
136
137 idev = in6_dev_get(skb->dev);
138
139 /* Fix up skb to look at the embedded net header. */
140 saveip = skb->network_header;
141 savesctp = skb->transport_header;
142 skb_reset_network_header(skb);
143 skb_set_transport_header(skb, offset);
144 sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
145 /* Put back, the original pointers. */
146 skb->network_header = saveip;
147 skb->transport_header = savesctp;
148 if (!sk) {
149 __ICMP6_INC_STATS(net, idev, ICMP6_MIB_INERRORS);
150 ret = -ENOENT;
151 goto out;
152 }
153
154 /* Warning: The sock lock is held. Remember to call
155 * sctp_err_finish!
156 */
157
158 switch (type) {
159 case ICMPV6_PKT_TOOBIG:
160 if (ip6_sk_accept_pmtu(sk))
161 sctp_icmp_frag_needed(sk, asoc, transport, ntohl(info));
162 goto out_unlock;
163 case ICMPV6_PARAMPROB:
164 if (ICMPV6_UNK_NEXTHDR == code) {
165 sctp_icmp_proto_unreachable(sk, asoc, transport);
166 goto out_unlock;
167 }
168 break;
169 case NDISC_REDIRECT:
170 sctp_icmp_redirect(sk, transport, skb);
171 goto out_unlock;
172 default:
173 break;
174 }
175
176 np = inet6_sk(sk);
177 icmpv6_err_convert(type, code, &err);
178 if (!sock_owned_by_user(sk) && np->recverr) {
179 sk->sk_err = err;
180 sk->sk_error_report(sk);
181 } else { /* Only an error on timeout */
182 sk->sk_err_soft = err;
183 }
184
185 out_unlock:
186 sctp_err_finish(sk, transport);
187 out:
188 if (likely(idev != NULL))
189 in6_dev_put(idev);
190
191 return ret;
192 }
193
sctp_v6_xmit(struct sk_buff * skb,struct sctp_transport * transport)194 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *transport)
195 {
196 struct sock *sk = skb->sk;
197 struct ipv6_pinfo *np = inet6_sk(sk);
198 struct flowi6 *fl6 = &transport->fl.u.ip6;
199 __u8 tclass = np->tclass;
200 int res;
201
202 pr_debug("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n", __func__, skb,
203 skb->len, &fl6->saddr, &fl6->daddr);
204
205 if (transport->dscp & SCTP_DSCP_SET_MASK)
206 tclass = transport->dscp & SCTP_DSCP_VAL_MASK;
207
208 if (INET_ECN_is_capable(tclass))
209 IP6_ECN_flow_xmit(sk, fl6->flowlabel);
210
211 if (!(transport->param_flags & SPP_PMTUD_ENABLE))
212 skb->ignore_df = 1;
213
214 SCTP_INC_STATS(sock_net(sk), SCTP_MIB_OUTSCTPPACKS);
215
216 rcu_read_lock();
217 res = ip6_xmit(sk, skb, fl6, sk->sk_mark, rcu_dereference(np->opt),
218 tclass, sk->sk_priority);
219 rcu_read_unlock();
220 return res;
221 }
222
223 /* Returns the dst cache entry for the given source and destination ip
224 * addresses.
225 */
sctp_v6_get_dst(struct sctp_transport * t,union sctp_addr * saddr,struct flowi * fl,struct sock * sk)226 static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
227 struct flowi *fl, struct sock *sk)
228 {
229 struct sctp_association *asoc = t->asoc;
230 struct dst_entry *dst = NULL;
231 struct flowi _fl;
232 struct flowi6 *fl6 = &_fl.u.ip6;
233 struct sctp_bind_addr *bp;
234 struct ipv6_pinfo *np = inet6_sk(sk);
235 struct sctp_sockaddr_entry *laddr;
236 union sctp_addr *daddr = &t->ipaddr;
237 union sctp_addr dst_saddr;
238 struct in6_addr *final_p, final;
239 enum sctp_scope scope;
240 __u8 matchlen = 0;
241
242 memset(&_fl, 0, sizeof(_fl));
243 fl6->daddr = daddr->v6.sin6_addr;
244 fl6->fl6_dport = daddr->v6.sin6_port;
245 fl6->flowi6_proto = IPPROTO_SCTP;
246 if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
247 fl6->flowi6_oif = daddr->v6.sin6_scope_id;
248 else if (asoc)
249 fl6->flowi6_oif = asoc->base.sk->sk_bound_dev_if;
250 if (t->flowlabel & SCTP_FLOWLABEL_SET_MASK)
251 fl6->flowlabel = htonl(t->flowlabel & SCTP_FLOWLABEL_VAL_MASK);
252
253 if (np->sndflow && (fl6->flowlabel & IPV6_FLOWLABEL_MASK)) {
254 struct ip6_flowlabel *flowlabel;
255
256 flowlabel = fl6_sock_lookup(sk, fl6->flowlabel);
257 if (IS_ERR(flowlabel))
258 goto out;
259 fl6_sock_release(flowlabel);
260 }
261
262 pr_debug("%s: dst=%pI6 ", __func__, &fl6->daddr);
263
264 if (asoc)
265 fl6->fl6_sport = htons(asoc->base.bind_addr.port);
266
267 if (saddr) {
268 fl6->saddr = saddr->v6.sin6_addr;
269 if (!fl6->fl6_sport)
270 fl6->fl6_sport = saddr->v6.sin6_port;
271
272 pr_debug("src=%pI6 - ", &fl6->saddr);
273 }
274
275 rcu_read_lock();
276 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
277 rcu_read_unlock();
278
279 dst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p);
280 if (!asoc || saddr) {
281 t->dst = dst;
282 memcpy(fl, &_fl, sizeof(_fl));
283 goto out;
284 }
285
286 bp = &asoc->base.bind_addr;
287 scope = sctp_scope(daddr);
288 /* ip6_dst_lookup has filled in the fl6->saddr for us. Check
289 * to see if we can use it.
290 */
291 if (!IS_ERR(dst)) {
292 /* Walk through the bind address list and look for a bind
293 * address that matches the source address of the returned dst.
294 */
295 sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port));
296 rcu_read_lock();
297 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
298 if (!laddr->valid || laddr->state == SCTP_ADDR_DEL ||
299 (laddr->state != SCTP_ADDR_SRC &&
300 !asoc->src_out_of_asoc_ok))
301 continue;
302
303 /* Do not compare against v4 addrs */
304 if ((laddr->a.sa.sa_family == AF_INET6) &&
305 (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) {
306 rcu_read_unlock();
307 t->dst = dst;
308 memcpy(fl, &_fl, sizeof(_fl));
309 goto out;
310 }
311 }
312 rcu_read_unlock();
313 /* None of the bound addresses match the source address of the
314 * dst. So release it.
315 */
316 dst_release(dst);
317 dst = NULL;
318 }
319
320 /* Walk through the bind address list and try to get the
321 * best source address for a given destination.
322 */
323 rcu_read_lock();
324 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
325 struct dst_entry *bdst;
326 __u8 bmatchlen;
327
328 if (!laddr->valid ||
329 laddr->state != SCTP_ADDR_SRC ||
330 laddr->a.sa.sa_family != AF_INET6 ||
331 scope > sctp_scope(&laddr->a))
332 continue;
333
334 fl6->saddr = laddr->a.v6.sin6_addr;
335 fl6->fl6_sport = laddr->a.v6.sin6_port;
336 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
337 bdst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p);
338
339 if (IS_ERR(bdst))
340 continue;
341
342 if (ipv6_chk_addr(dev_net(bdst->dev),
343 &laddr->a.v6.sin6_addr, bdst->dev, 1)) {
344 if (!IS_ERR_OR_NULL(dst))
345 dst_release(dst);
346 dst = bdst;
347 t->dst = dst;
348 memcpy(fl, &_fl, sizeof(_fl));
349 break;
350 }
351
352 bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
353 if (matchlen > bmatchlen) {
354 dst_release(bdst);
355 continue;
356 }
357
358 if (!IS_ERR_OR_NULL(dst))
359 dst_release(dst);
360 dst = bdst;
361 matchlen = bmatchlen;
362 t->dst = dst;
363 memcpy(fl, &_fl, sizeof(_fl));
364 }
365 rcu_read_unlock();
366
367 out:
368 if (!IS_ERR_OR_NULL(dst)) {
369 struct rt6_info *rt;
370
371 rt = (struct rt6_info *)dst;
372 t->dst_cookie = rt6_get_cookie(rt);
373 pr_debug("rt6_dst:%pI6/%d rt6_src:%pI6\n",
374 &rt->rt6i_dst.addr, rt->rt6i_dst.plen,
375 &fl->u.ip6.saddr);
376 } else {
377 t->dst = NULL;
378 pr_debug("no route\n");
379 }
380 }
381
382 /* Returns the number of consecutive initial bits that match in the 2 ipv6
383 * addresses.
384 */
sctp_v6_addr_match_len(union sctp_addr * s1,union sctp_addr * s2)385 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
386 union sctp_addr *s2)
387 {
388 return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
389 }
390
391 /* Fills in the source address(saddr) based on the destination address(daddr)
392 * and asoc's bind address list.
393 */
sctp_v6_get_saddr(struct sctp_sock * sk,struct sctp_transport * t,struct flowi * fl)394 static void sctp_v6_get_saddr(struct sctp_sock *sk,
395 struct sctp_transport *t,
396 struct flowi *fl)
397 {
398 struct flowi6 *fl6 = &fl->u.ip6;
399 union sctp_addr *saddr = &t->saddr;
400
401 pr_debug("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);
402
403 if (t->dst) {
404 saddr->v6.sin6_family = AF_INET6;
405 saddr->v6.sin6_addr = fl6->saddr;
406 }
407 }
408
409 /* Make a copy of all potential local addresses. */
sctp_v6_copy_addrlist(struct list_head * addrlist,struct net_device * dev)410 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
411 struct net_device *dev)
412 {
413 struct inet6_dev *in6_dev;
414 struct inet6_ifaddr *ifp;
415 struct sctp_sockaddr_entry *addr;
416
417 rcu_read_lock();
418 if ((in6_dev = __in6_dev_get(dev)) == NULL) {
419 rcu_read_unlock();
420 return;
421 }
422
423 read_lock_bh(&in6_dev->lock);
424 list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
425 /* Add the address to the local list. */
426 addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
427 if (addr) {
428 addr->a.v6.sin6_family = AF_INET6;
429 addr->a.v6.sin6_addr = ifp->addr;
430 addr->a.v6.sin6_scope_id = dev->ifindex;
431 addr->valid = 1;
432 INIT_LIST_HEAD(&addr->list);
433 list_add_tail(&addr->list, addrlist);
434 }
435 }
436
437 read_unlock_bh(&in6_dev->lock);
438 rcu_read_unlock();
439 }
440
441 /* Copy over any ip options */
sctp_v6_copy_ip_options(struct sock * sk,struct sock * newsk)442 static void sctp_v6_copy_ip_options(struct sock *sk, struct sock *newsk)
443 {
444 struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
445 struct ipv6_txoptions *opt;
446
447 newnp = inet6_sk(newsk);
448
449 rcu_read_lock();
450 opt = rcu_dereference(np->opt);
451 if (opt) {
452 opt = ipv6_dup_options(newsk, opt);
453 if (!opt)
454 pr_err("%s: Failed to copy ip options\n", __func__);
455 }
456 RCU_INIT_POINTER(newnp->opt, opt);
457 rcu_read_unlock();
458 }
459
460 /* Account for the IP options */
sctp_v6_ip_options_len(struct sock * sk)461 static int sctp_v6_ip_options_len(struct sock *sk)
462 {
463 struct ipv6_pinfo *np = inet6_sk(sk);
464 struct ipv6_txoptions *opt;
465 int len = 0;
466
467 rcu_read_lock();
468 opt = rcu_dereference(np->opt);
469 if (opt)
470 len = opt->opt_flen + opt->opt_nflen;
471
472 rcu_read_unlock();
473 return len;
474 }
475
476 /* Initialize a sockaddr_storage from in incoming skb. */
sctp_v6_from_skb(union sctp_addr * addr,struct sk_buff * skb,int is_saddr)477 static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb,
478 int is_saddr)
479 {
480 /* Always called on head skb, so this is safe */
481 struct sctphdr *sh = sctp_hdr(skb);
482 struct sockaddr_in6 *sa = &addr->v6;
483
484 addr->v6.sin6_family = AF_INET6;
485 addr->v6.sin6_flowinfo = 0; /* FIXME */
486 addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
487
488 if (is_saddr) {
489 sa->sin6_port = sh->source;
490 sa->sin6_addr = ipv6_hdr(skb)->saddr;
491 } else {
492 sa->sin6_port = sh->dest;
493 sa->sin6_addr = ipv6_hdr(skb)->daddr;
494 }
495 }
496
497 /* Initialize an sctp_addr from a socket. */
sctp_v6_from_sk(union sctp_addr * addr,struct sock * sk)498 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
499 {
500 addr->v6.sin6_family = AF_INET6;
501 addr->v6.sin6_port = 0;
502 addr->v6.sin6_addr = sk->sk_v6_rcv_saddr;
503 }
504
505 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
sctp_v6_to_sk_saddr(union sctp_addr * addr,struct sock * sk)506 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
507 {
508 if (addr->sa.sa_family == AF_INET) {
509 sk->sk_v6_rcv_saddr.s6_addr32[0] = 0;
510 sk->sk_v6_rcv_saddr.s6_addr32[1] = 0;
511 sk->sk_v6_rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
512 sk->sk_v6_rcv_saddr.s6_addr32[3] =
513 addr->v4.sin_addr.s_addr;
514 } else {
515 sk->sk_v6_rcv_saddr = addr->v6.sin6_addr;
516 }
517 }
518
519 /* Initialize sk->sk_daddr from sctp_addr. */
sctp_v6_to_sk_daddr(union sctp_addr * addr,struct sock * sk)520 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
521 {
522 if (addr->sa.sa_family == AF_INET) {
523 sk->sk_v6_daddr.s6_addr32[0] = 0;
524 sk->sk_v6_daddr.s6_addr32[1] = 0;
525 sk->sk_v6_daddr.s6_addr32[2] = htonl(0x0000ffff);
526 sk->sk_v6_daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
527 } else {
528 sk->sk_v6_daddr = addr->v6.sin6_addr;
529 }
530 }
531
532 /* Initialize a sctp_addr from an address parameter. */
sctp_v6_from_addr_param(union sctp_addr * addr,union sctp_addr_param * param,__be16 port,int iif)533 static void sctp_v6_from_addr_param(union sctp_addr *addr,
534 union sctp_addr_param *param,
535 __be16 port, int iif)
536 {
537 addr->v6.sin6_family = AF_INET6;
538 addr->v6.sin6_port = port;
539 addr->v6.sin6_flowinfo = 0; /* BUG */
540 addr->v6.sin6_addr = param->v6.addr;
541 addr->v6.sin6_scope_id = iif;
542 }
543
544 /* Initialize an address parameter from a sctp_addr and return the length
545 * of the address parameter.
546 */
sctp_v6_to_addr_param(const union sctp_addr * addr,union sctp_addr_param * param)547 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
548 union sctp_addr_param *param)
549 {
550 int length = sizeof(struct sctp_ipv6addr_param);
551
552 param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
553 param->v6.param_hdr.length = htons(length);
554 param->v6.addr = addr->v6.sin6_addr;
555
556 return length;
557 }
558
559 /* Initialize a sctp_addr from struct in6_addr. */
sctp_v6_to_addr(union sctp_addr * addr,struct in6_addr * saddr,__be16 port)560 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
561 __be16 port)
562 {
563 addr->sa.sa_family = AF_INET6;
564 addr->v6.sin6_port = port;
565 addr->v6.sin6_flowinfo = 0;
566 addr->v6.sin6_addr = *saddr;
567 addr->v6.sin6_scope_id = 0;
568 }
569
__sctp_v6_cmp_addr(const union sctp_addr * addr1,const union sctp_addr * addr2)570 static int __sctp_v6_cmp_addr(const union sctp_addr *addr1,
571 const union sctp_addr *addr2)
572 {
573 if (addr1->sa.sa_family != addr2->sa.sa_family) {
574 if (addr1->sa.sa_family == AF_INET &&
575 addr2->sa.sa_family == AF_INET6 &&
576 ipv6_addr_v4mapped(&addr2->v6.sin6_addr) &&
577 addr2->v6.sin6_addr.s6_addr32[3] ==
578 addr1->v4.sin_addr.s_addr)
579 return 1;
580
581 if (addr2->sa.sa_family == AF_INET &&
582 addr1->sa.sa_family == AF_INET6 &&
583 ipv6_addr_v4mapped(&addr1->v6.sin6_addr) &&
584 addr1->v6.sin6_addr.s6_addr32[3] ==
585 addr2->v4.sin_addr.s_addr)
586 return 1;
587
588 return 0;
589 }
590
591 if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
592 return 0;
593
594 /* If this is a linklocal address, compare the scope_id. */
595 if ((ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) &&
596 addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
597 addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)
598 return 0;
599
600 return 1;
601 }
602
603 /* Compare addresses exactly.
604 * v4-mapped-v6 is also in consideration.
605 */
sctp_v6_cmp_addr(const union sctp_addr * addr1,const union sctp_addr * addr2)606 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
607 const union sctp_addr *addr2)
608 {
609 return __sctp_v6_cmp_addr(addr1, addr2) &&
610 addr1->v6.sin6_port == addr2->v6.sin6_port;
611 }
612
613 /* Initialize addr struct to INADDR_ANY. */
sctp_v6_inaddr_any(union sctp_addr * addr,__be16 port)614 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
615 {
616 memset(addr, 0x00, sizeof(union sctp_addr));
617 addr->v6.sin6_family = AF_INET6;
618 addr->v6.sin6_port = port;
619 }
620
621 /* Is this a wildcard address? */
sctp_v6_is_any(const union sctp_addr * addr)622 static int sctp_v6_is_any(const union sctp_addr *addr)
623 {
624 return ipv6_addr_any(&addr->v6.sin6_addr);
625 }
626
627 /* Should this be available for binding? */
sctp_v6_available(union sctp_addr * addr,struct sctp_sock * sp)628 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
629 {
630 int type;
631 struct net *net = sock_net(&sp->inet.sk);
632 const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
633
634 type = ipv6_addr_type(in6);
635 if (IPV6_ADDR_ANY == type)
636 return 1;
637 if (type == IPV6_ADDR_MAPPED) {
638 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
639 return 0;
640 sctp_v6_map_v4(addr);
641 return sctp_get_af_specific(AF_INET)->available(addr, sp);
642 }
643 if (!(type & IPV6_ADDR_UNICAST))
644 return 0;
645
646 return sp->inet.freebind || net->ipv6.sysctl.ip_nonlocal_bind ||
647 ipv6_chk_addr(net, in6, NULL, 0);
648 }
649
650 /* This function checks if the address is a valid address to be used for
651 * SCTP.
652 *
653 * Output:
654 * Return 0 - If the address is a non-unicast or an illegal address.
655 * Return 1 - If the address is a unicast.
656 */
sctp_v6_addr_valid(union sctp_addr * addr,struct sctp_sock * sp,const struct sk_buff * skb)657 static int sctp_v6_addr_valid(union sctp_addr *addr,
658 struct sctp_sock *sp,
659 const struct sk_buff *skb)
660 {
661 int ret = ipv6_addr_type(&addr->v6.sin6_addr);
662
663 /* Support v4-mapped-v6 address. */
664 if (ret == IPV6_ADDR_MAPPED) {
665 /* Note: This routine is used in input, so v4-mapped-v6
666 * are disallowed here when there is no sctp_sock.
667 */
668 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
669 return 0;
670 sctp_v6_map_v4(addr);
671 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
672 }
673
674 /* Is this a non-unicast address */
675 if (!(ret & IPV6_ADDR_UNICAST))
676 return 0;
677
678 return 1;
679 }
680
681 /* What is the scope of 'addr'? */
sctp_v6_scope(union sctp_addr * addr)682 static enum sctp_scope sctp_v6_scope(union sctp_addr *addr)
683 {
684 enum sctp_scope retval;
685 int v6scope;
686
687 /* The IPv6 scope is really a set of bit fields.
688 * See IFA_* in <net/if_inet6.h>. Map to a generic SCTP scope.
689 */
690
691 v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
692 switch (v6scope) {
693 case IFA_HOST:
694 retval = SCTP_SCOPE_LOOPBACK;
695 break;
696 case IFA_LINK:
697 retval = SCTP_SCOPE_LINK;
698 break;
699 case IFA_SITE:
700 retval = SCTP_SCOPE_PRIVATE;
701 break;
702 default:
703 retval = SCTP_SCOPE_GLOBAL;
704 break;
705 }
706
707 return retval;
708 }
709
710 /* Create and initialize a new sk for the socket to be returned by accept(). */
sctp_v6_create_accept_sk(struct sock * sk,struct sctp_association * asoc,bool kern)711 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
712 struct sctp_association *asoc,
713 bool kern)
714 {
715 struct sock *newsk;
716 struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
717 struct sctp6_sock *newsctp6sk;
718
719 newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot, kern);
720 if (!newsk)
721 goto out;
722
723 sock_init_data(NULL, newsk);
724
725 sctp_copy_sock(newsk, sk, asoc);
726 sock_reset_flag(sk, SOCK_ZAPPED);
727
728 newsctp6sk = (struct sctp6_sock *)newsk;
729 inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
730
731 sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
732
733 newnp = inet6_sk(newsk);
734
735 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
736 newnp->ipv6_mc_list = NULL;
737 newnp->ipv6_ac_list = NULL;
738 newnp->ipv6_fl_list = NULL;
739
740 sctp_v6_copy_ip_options(sk, newsk);
741
742 /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
743 * and getpeername().
744 */
745 sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
746
747 newsk->sk_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
748
749 sk_refcnt_debug_inc(newsk);
750
751 if (newsk->sk_prot->init(newsk)) {
752 sk_common_release(newsk);
753 newsk = NULL;
754 }
755
756 out:
757 return newsk;
758 }
759
760 /* Format a sockaddr for return to user space. This makes sure the return is
761 * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option.
762 */
sctp_v6_addr_to_user(struct sctp_sock * sp,union sctp_addr * addr)763 static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr)
764 {
765 if (sp->v4mapped) {
766 if (addr->sa.sa_family == AF_INET)
767 sctp_v4_map_v6(addr);
768 } else {
769 if (addr->sa.sa_family == AF_INET6 &&
770 ipv6_addr_v4mapped(&addr->v6.sin6_addr))
771 sctp_v6_map_v4(addr);
772 }
773
774 if (addr->sa.sa_family == AF_INET) {
775 memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
776 return sizeof(struct sockaddr_in);
777 }
778 return sizeof(struct sockaddr_in6);
779 }
780
781 /* Where did this skb come from? */
sctp_v6_skb_iif(const struct sk_buff * skb)782 static int sctp_v6_skb_iif(const struct sk_buff *skb)
783 {
784 return IP6CB(skb)->iif;
785 }
786
787 /* Was this packet marked by Explicit Congestion Notification? */
sctp_v6_is_ce(const struct sk_buff * skb)788 static int sctp_v6_is_ce(const struct sk_buff *skb)
789 {
790 return *((__u32 *)(ipv6_hdr(skb))) & (__force __u32)htonl(1 << 20);
791 }
792
793 /* Dump the v6 addr to the seq file. */
sctp_v6_seq_dump_addr(struct seq_file * seq,union sctp_addr * addr)794 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
795 {
796 seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
797 }
798
sctp_v6_ecn_capable(struct sock * sk)799 static void sctp_v6_ecn_capable(struct sock *sk)
800 {
801 inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
802 }
803
804 /* Initialize a PF_INET msgname from a ulpevent. */
sctp_inet6_event_msgname(struct sctp_ulpevent * event,char * msgname,int * addrlen)805 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
806 char *msgname, int *addrlen)
807 {
808 union sctp_addr *addr;
809 struct sctp_association *asoc;
810 union sctp_addr *paddr;
811
812 if (!msgname)
813 return;
814
815 addr = (union sctp_addr *)msgname;
816 asoc = event->asoc;
817 paddr = &asoc->peer.primary_addr;
818
819 if (paddr->sa.sa_family == AF_INET) {
820 addr->v4.sin_family = AF_INET;
821 addr->v4.sin_port = htons(asoc->peer.port);
822 addr->v4.sin_addr = paddr->v4.sin_addr;
823 } else {
824 addr->v6.sin6_family = AF_INET6;
825 addr->v6.sin6_flowinfo = 0;
826 if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
827 addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id;
828 else
829 addr->v6.sin6_scope_id = 0;
830 addr->v6.sin6_port = htons(asoc->peer.port);
831 addr->v6.sin6_addr = paddr->v6.sin6_addr;
832 }
833
834 *addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr);
835 }
836
837 /* Initialize a msg_name from an inbound skb. */
sctp_inet6_skb_msgname(struct sk_buff * skb,char * msgname,int * addr_len)838 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
839 int *addr_len)
840 {
841 union sctp_addr *addr;
842 struct sctphdr *sh;
843
844 if (!msgname)
845 return;
846
847 addr = (union sctp_addr *)msgname;
848 sh = sctp_hdr(skb);
849
850 if (ip_hdr(skb)->version == 4) {
851 addr->v4.sin_family = AF_INET;
852 addr->v4.sin_port = sh->source;
853 addr->v4.sin_addr.s_addr = ip_hdr(skb)->saddr;
854 } else {
855 addr->v6.sin6_family = AF_INET6;
856 addr->v6.sin6_flowinfo = 0;
857 addr->v6.sin6_port = sh->source;
858 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
859 if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
860 addr->v6.sin6_scope_id = sctp_v6_skb_iif(skb);
861 else
862 addr->v6.sin6_scope_id = 0;
863 }
864
865 *addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr);
866 }
867
868 /* Do we support this AF? */
sctp_inet6_af_supported(sa_family_t family,struct sctp_sock * sp)869 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
870 {
871 switch (family) {
872 case AF_INET6:
873 return 1;
874 /* v4-mapped-v6 addresses */
875 case AF_INET:
876 if (!__ipv6_only_sock(sctp_opt2sk(sp)))
877 return 1;
878 fallthrough;
879 default:
880 return 0;
881 }
882 }
883
884 /* Address matching with wildcards allowed. This extra level
885 * of indirection lets us choose whether a PF_INET6 should
886 * disallow any v4 addresses if we so choose.
887 */
sctp_inet6_cmp_addr(const union sctp_addr * addr1,const union sctp_addr * addr2,struct sctp_sock * opt)888 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
889 const union sctp_addr *addr2,
890 struct sctp_sock *opt)
891 {
892 struct sock *sk = sctp_opt2sk(opt);
893 struct sctp_af *af1, *af2;
894
895 af1 = sctp_get_af_specific(addr1->sa.sa_family);
896 af2 = sctp_get_af_specific(addr2->sa.sa_family);
897
898 if (!af1 || !af2)
899 return 0;
900
901 /* If the socket is IPv6 only, v4 addrs will not match */
902 if (__ipv6_only_sock(sk) && af1 != af2)
903 return 0;
904
905 /* Today, wildcard AF_INET/AF_INET6. */
906 if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
907 return 1;
908
909 if (addr1->sa.sa_family == AF_INET && addr2->sa.sa_family == AF_INET)
910 return addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr;
911
912 return __sctp_v6_cmp_addr(addr1, addr2);
913 }
914
915 /* Verify that the provided sockaddr looks bindable. Common verification,
916 * has already been taken care of.
917 */
sctp_inet6_bind_verify(struct sctp_sock * opt,union sctp_addr * addr)918 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
919 {
920 struct sctp_af *af;
921
922 /* ASSERT: address family has already been verified. */
923 if (addr->sa.sa_family != AF_INET6)
924 af = sctp_get_af_specific(addr->sa.sa_family);
925 else {
926 int type = ipv6_addr_type(&addr->v6.sin6_addr);
927 struct net_device *dev;
928
929 if (type & IPV6_ADDR_LINKLOCAL) {
930 struct net *net;
931 if (!addr->v6.sin6_scope_id)
932 return 0;
933 net = sock_net(&opt->inet.sk);
934 rcu_read_lock();
935 dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id);
936 if (!dev || !(opt->inet.freebind ||
937 net->ipv6.sysctl.ip_nonlocal_bind ||
938 ipv6_chk_addr(net, &addr->v6.sin6_addr,
939 dev, 0))) {
940 rcu_read_unlock();
941 return 0;
942 }
943 rcu_read_unlock();
944 }
945
946 af = opt->pf->af;
947 }
948 return af->available(addr, opt);
949 }
950
951 /* Verify that the provided sockaddr looks sendable. Common verification,
952 * has already been taken care of.
953 */
sctp_inet6_send_verify(struct sctp_sock * opt,union sctp_addr * addr)954 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
955 {
956 struct sctp_af *af = NULL;
957
958 /* ASSERT: address family has already been verified. */
959 if (addr->sa.sa_family != AF_INET6)
960 af = sctp_get_af_specific(addr->sa.sa_family);
961 else {
962 int type = ipv6_addr_type(&addr->v6.sin6_addr);
963 struct net_device *dev;
964
965 if (type & IPV6_ADDR_LINKLOCAL) {
966 if (!addr->v6.sin6_scope_id)
967 return 0;
968 rcu_read_lock();
969 dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk),
970 addr->v6.sin6_scope_id);
971 rcu_read_unlock();
972 if (!dev)
973 return 0;
974 }
975 af = opt->pf->af;
976 }
977
978 return af != NULL;
979 }
980
981 /* Fill in Supported Address Type information for INIT and INIT-ACK
982 * chunks. Note: In the future, we may want to look at sock options
983 * to determine whether a PF_INET6 socket really wants to have IPV4
984 * addresses.
985 * Returns number of addresses supported.
986 */
sctp_inet6_supported_addrs(const struct sctp_sock * opt,__be16 * types)987 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
988 __be16 *types)
989 {
990 types[0] = SCTP_PARAM_IPV6_ADDRESS;
991 if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
992 types[1] = SCTP_PARAM_IPV4_ADDRESS;
993 return 2;
994 }
995 return 1;
996 }
997
998 /* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */
sctp_getname(struct socket * sock,struct sockaddr * uaddr,int peer)999 static int sctp_getname(struct socket *sock, struct sockaddr *uaddr,
1000 int peer)
1001 {
1002 int rc;
1003
1004 rc = inet6_getname(sock, uaddr, peer);
1005
1006 if (rc < 0)
1007 return rc;
1008
1009 rc = sctp_v6_addr_to_user(sctp_sk(sock->sk),
1010 (union sctp_addr *)uaddr);
1011
1012 return rc;
1013 }
1014
1015 static const struct proto_ops inet6_seqpacket_ops = {
1016 .family = PF_INET6,
1017 .owner = THIS_MODULE,
1018 .release = inet6_release,
1019 .bind = inet6_bind,
1020 .connect = sctp_inet_connect,
1021 .socketpair = sock_no_socketpair,
1022 .accept = inet_accept,
1023 .getname = sctp_getname,
1024 .poll = sctp_poll,
1025 .ioctl = inet6_ioctl,
1026 .gettstamp = sock_gettstamp,
1027 .listen = sctp_inet_listen,
1028 .shutdown = inet_shutdown,
1029 .setsockopt = sock_common_setsockopt,
1030 .getsockopt = sock_common_getsockopt,
1031 .sendmsg = inet_sendmsg,
1032 .recvmsg = inet_recvmsg,
1033 .mmap = sock_no_mmap,
1034 #ifdef CONFIG_COMPAT
1035 .compat_ioctl = inet6_compat_ioctl,
1036 #endif
1037 };
1038
1039 static struct inet_protosw sctpv6_seqpacket_protosw = {
1040 .type = SOCK_SEQPACKET,
1041 .protocol = IPPROTO_SCTP,
1042 .prot = &sctpv6_prot,
1043 .ops = &inet6_seqpacket_ops,
1044 .flags = SCTP_PROTOSW_FLAG
1045 };
1046 static struct inet_protosw sctpv6_stream_protosw = {
1047 .type = SOCK_STREAM,
1048 .protocol = IPPROTO_SCTP,
1049 .prot = &sctpv6_prot,
1050 .ops = &inet6_seqpacket_ops,
1051 .flags = SCTP_PROTOSW_FLAG,
1052 };
1053
sctp6_rcv(struct sk_buff * skb)1054 static int sctp6_rcv(struct sk_buff *skb)
1055 {
1056 return sctp_rcv(skb) ? -1 : 0;
1057 }
1058
1059 static const struct inet6_protocol sctpv6_protocol = {
1060 .handler = sctp6_rcv,
1061 .err_handler = sctp_v6_err,
1062 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
1063 };
1064
1065 static struct sctp_af sctp_af_inet6 = {
1066 .sa_family = AF_INET6,
1067 .sctp_xmit = sctp_v6_xmit,
1068 .setsockopt = ipv6_setsockopt,
1069 .getsockopt = ipv6_getsockopt,
1070 .get_dst = sctp_v6_get_dst,
1071 .get_saddr = sctp_v6_get_saddr,
1072 .copy_addrlist = sctp_v6_copy_addrlist,
1073 .from_skb = sctp_v6_from_skb,
1074 .from_sk = sctp_v6_from_sk,
1075 .from_addr_param = sctp_v6_from_addr_param,
1076 .to_addr_param = sctp_v6_to_addr_param,
1077 .cmp_addr = sctp_v6_cmp_addr,
1078 .scope = sctp_v6_scope,
1079 .addr_valid = sctp_v6_addr_valid,
1080 .inaddr_any = sctp_v6_inaddr_any,
1081 .is_any = sctp_v6_is_any,
1082 .available = sctp_v6_available,
1083 .skb_iif = sctp_v6_skb_iif,
1084 .is_ce = sctp_v6_is_ce,
1085 .seq_dump_addr = sctp_v6_seq_dump_addr,
1086 .ecn_capable = sctp_v6_ecn_capable,
1087 .net_header_len = sizeof(struct ipv6hdr),
1088 .sockaddr_len = sizeof(struct sockaddr_in6),
1089 .ip_options_len = sctp_v6_ip_options_len,
1090 };
1091
1092 static struct sctp_pf sctp_pf_inet6 = {
1093 .event_msgname = sctp_inet6_event_msgname,
1094 .skb_msgname = sctp_inet6_skb_msgname,
1095 .af_supported = sctp_inet6_af_supported,
1096 .cmp_addr = sctp_inet6_cmp_addr,
1097 .bind_verify = sctp_inet6_bind_verify,
1098 .send_verify = sctp_inet6_send_verify,
1099 .supported_addrs = sctp_inet6_supported_addrs,
1100 .create_accept_sk = sctp_v6_create_accept_sk,
1101 .addr_to_user = sctp_v6_addr_to_user,
1102 .to_sk_saddr = sctp_v6_to_sk_saddr,
1103 .to_sk_daddr = sctp_v6_to_sk_daddr,
1104 .copy_ip_options = sctp_v6_copy_ip_options,
1105 .af = &sctp_af_inet6,
1106 };
1107
1108 /* Initialize IPv6 support and register with socket layer. */
sctp_v6_pf_init(void)1109 void sctp_v6_pf_init(void)
1110 {
1111 /* Register the SCTP specific PF_INET6 functions. */
1112 sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1113
1114 /* Register the SCTP specific AF_INET6 functions. */
1115 sctp_register_af(&sctp_af_inet6);
1116 }
1117
sctp_v6_pf_exit(void)1118 void sctp_v6_pf_exit(void)
1119 {
1120 list_del(&sctp_af_inet6.list);
1121 }
1122
1123 /* Initialize IPv6 support and register with socket layer. */
sctp_v6_protosw_init(void)1124 int sctp_v6_protosw_init(void)
1125 {
1126 int rc;
1127
1128 rc = proto_register(&sctpv6_prot, 1);
1129 if (rc)
1130 return rc;
1131
1132 /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1133 inet6_register_protosw(&sctpv6_seqpacket_protosw);
1134 inet6_register_protosw(&sctpv6_stream_protosw);
1135
1136 return 0;
1137 }
1138
sctp_v6_protosw_exit(void)1139 void sctp_v6_protosw_exit(void)
1140 {
1141 inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1142 inet6_unregister_protosw(&sctpv6_stream_protosw);
1143 proto_unregister(&sctpv6_prot);
1144 }
1145
1146
1147 /* Register with inet6 layer. */
sctp_v6_add_protocol(void)1148 int sctp_v6_add_protocol(void)
1149 {
1150 /* Register notifier for inet6 address additions/deletions. */
1151 register_inet6addr_notifier(&sctp_inet6addr_notifier);
1152
1153 if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1154 return -EAGAIN;
1155
1156 return 0;
1157 }
1158
1159 /* Unregister with inet6 layer. */
sctp_v6_del_protocol(void)1160 void sctp_v6_del_protocol(void)
1161 {
1162 inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1163 unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1164 }
1165
