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 flowi6 *fl6 = &fl->u.ip6;
232 struct sctp_bind_addr *bp;
233 struct ipv6_pinfo *np = inet6_sk(sk);
234 struct sctp_sockaddr_entry *laddr;
235 union sctp_addr *daddr = &t->ipaddr;
236 union sctp_addr dst_saddr;
237 struct in6_addr *final_p, final;
238 enum sctp_scope scope;
239 __u8 matchlen = 0;
240
241 memset(fl6, 0, sizeof(struct flowi6));
242 fl6->daddr = daddr->v6.sin6_addr;
243 fl6->fl6_dport = daddr->v6.sin6_port;
244 fl6->flowi6_proto = IPPROTO_SCTP;
245 if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
246 fl6->flowi6_oif = daddr->v6.sin6_scope_id;
247 else if (asoc)
248 fl6->flowi6_oif = asoc->base.sk->sk_bound_dev_if;
249 if (t->flowlabel & SCTP_FLOWLABEL_SET_MASK)
250 fl6->flowlabel = htonl(t->flowlabel & SCTP_FLOWLABEL_VAL_MASK);
251
252 if (np->sndflow && (fl6->flowlabel & IPV6_FLOWLABEL_MASK)) {
253 struct ip6_flowlabel *flowlabel;
254
255 flowlabel = fl6_sock_lookup(sk, fl6->flowlabel);
256 if (IS_ERR(flowlabel))
257 goto out;
258 fl6_sock_release(flowlabel);
259 }
260
261 pr_debug("%s: dst=%pI6 ", __func__, &fl6->daddr);
262
263 if (asoc)
264 fl6->fl6_sport = htons(asoc->base.bind_addr.port);
265
266 if (saddr) {
267 fl6->saddr = saddr->v6.sin6_addr;
268 if (!fl6->fl6_sport)
269 fl6->fl6_sport = saddr->v6.sin6_port;
270
271 pr_debug("src=%pI6 - ", &fl6->saddr);
272 }
273
274 rcu_read_lock();
275 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
276 rcu_read_unlock();
277
278 dst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p);
279 if (!asoc || saddr)
280 goto out;
281
282 bp = &asoc->base.bind_addr;
283 scope = sctp_scope(daddr);
284 /* ip6_dst_lookup has filled in the fl6->saddr for us. Check
285 * to see if we can use it.
286 */
287 if (!IS_ERR(dst)) {
288 /* Walk through the bind address list and look for a bind
289 * address that matches the source address of the returned dst.
290 */
291 sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port));
292 rcu_read_lock();
293 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
294 if (!laddr->valid || laddr->state == SCTP_ADDR_DEL ||
295 (laddr->state != SCTP_ADDR_SRC &&
296 !asoc->src_out_of_asoc_ok))
297 continue;
298
299 /* Do not compare against v4 addrs */
300 if ((laddr->a.sa.sa_family == AF_INET6) &&
301 (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) {
302 rcu_read_unlock();
303 goto out;
304 }
305 }
306 rcu_read_unlock();
307 /* None of the bound addresses match the source address of the
308 * dst. So release it.
309 */
310 dst_release(dst);
311 dst = NULL;
312 }
313
314 /* Walk through the bind address list and try to get the
315 * best source address for a given destination.
316 */
317 rcu_read_lock();
318 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
319 struct dst_entry *bdst;
320 __u8 bmatchlen;
321
322 if (!laddr->valid ||
323 laddr->state != SCTP_ADDR_SRC ||
324 laddr->a.sa.sa_family != AF_INET6 ||
325 scope > sctp_scope(&laddr->a))
326 continue;
327
328 fl6->saddr = laddr->a.v6.sin6_addr;
329 fl6->fl6_sport = laddr->a.v6.sin6_port;
330 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
331 bdst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p);
332
333 if (IS_ERR(bdst))
334 continue;
335
336 if (ipv6_chk_addr(dev_net(bdst->dev),
337 &laddr->a.v6.sin6_addr, bdst->dev, 1)) {
338 if (!IS_ERR_OR_NULL(dst))
339 dst_release(dst);
340 dst = bdst;
341 break;
342 }
343
344 bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
345 if (matchlen > bmatchlen) {
346 dst_release(bdst);
347 continue;
348 }
349
350 if (!IS_ERR_OR_NULL(dst))
351 dst_release(dst);
352 dst = bdst;
353 matchlen = bmatchlen;
354 }
355 rcu_read_unlock();
356
357 out:
358 if (!IS_ERR_OR_NULL(dst)) {
359 struct rt6_info *rt;
360
361 rt = (struct rt6_info *)dst;
362 t->dst = dst;
363 t->dst_cookie = rt6_get_cookie(rt);
364 pr_debug("rt6_dst:%pI6/%d rt6_src:%pI6\n",
365 &rt->rt6i_dst.addr, rt->rt6i_dst.plen,
366 &fl6->saddr);
367 } else {
368 t->dst = NULL;
369
370 pr_debug("no route\n");
371 }
372 }
373
374 /* Returns the number of consecutive initial bits that match in the 2 ipv6
375 * addresses.
376 */
sctp_v6_addr_match_len(union sctp_addr * s1,union sctp_addr * s2)377 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
378 union sctp_addr *s2)
379 {
380 return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
381 }
382
383 /* Fills in the source address(saddr) based on the destination address(daddr)
384 * and asoc's bind address list.
385 */
sctp_v6_get_saddr(struct sctp_sock * sk,struct sctp_transport * t,struct flowi * fl)386 static void sctp_v6_get_saddr(struct sctp_sock *sk,
387 struct sctp_transport *t,
388 struct flowi *fl)
389 {
390 struct flowi6 *fl6 = &fl->u.ip6;
391 union sctp_addr *saddr = &t->saddr;
392
393 pr_debug("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);
394
395 if (t->dst) {
396 saddr->v6.sin6_family = AF_INET6;
397 saddr->v6.sin6_addr = fl6->saddr;
398 }
399 }
400
401 /* Make a copy of all potential local addresses. */
sctp_v6_copy_addrlist(struct list_head * addrlist,struct net_device * dev)402 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
403 struct net_device *dev)
404 {
405 struct inet6_dev *in6_dev;
406 struct inet6_ifaddr *ifp;
407 struct sctp_sockaddr_entry *addr;
408
409 rcu_read_lock();
410 if ((in6_dev = __in6_dev_get(dev)) == NULL) {
411 rcu_read_unlock();
412 return;
413 }
414
415 read_lock_bh(&in6_dev->lock);
416 list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
417 /* Add the address to the local list. */
418 addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
419 if (addr) {
420 addr->a.v6.sin6_family = AF_INET6;
421 addr->a.v6.sin6_addr = ifp->addr;
422 addr->a.v6.sin6_scope_id = dev->ifindex;
423 addr->valid = 1;
424 INIT_LIST_HEAD(&addr->list);
425 list_add_tail(&addr->list, addrlist);
426 }
427 }
428
429 read_unlock_bh(&in6_dev->lock);
430 rcu_read_unlock();
431 }
432
433 /* Copy over any ip options */
sctp_v6_copy_ip_options(struct sock * sk,struct sock * newsk)434 static void sctp_v6_copy_ip_options(struct sock *sk, struct sock *newsk)
435 {
436 struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
437 struct ipv6_txoptions *opt;
438
439 newnp = inet6_sk(newsk);
440
441 rcu_read_lock();
442 opt = rcu_dereference(np->opt);
443 if (opt) {
444 opt = ipv6_dup_options(newsk, opt);
445 if (!opt)
446 pr_err("%s: Failed to copy ip options\n", __func__);
447 }
448 RCU_INIT_POINTER(newnp->opt, opt);
449 rcu_read_unlock();
450 }
451
452 /* Account for the IP options */
sctp_v6_ip_options_len(struct sock * sk)453 static int sctp_v6_ip_options_len(struct sock *sk)
454 {
455 struct ipv6_pinfo *np = inet6_sk(sk);
456 struct ipv6_txoptions *opt;
457 int len = 0;
458
459 rcu_read_lock();
460 opt = rcu_dereference(np->opt);
461 if (opt)
462 len = opt->opt_flen + opt->opt_nflen;
463
464 rcu_read_unlock();
465 return len;
466 }
467
468 /* Initialize a sockaddr_storage from in incoming skb. */
sctp_v6_from_skb(union sctp_addr * addr,struct sk_buff * skb,int is_saddr)469 static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb,
470 int is_saddr)
471 {
472 /* Always called on head skb, so this is safe */
473 struct sctphdr *sh = sctp_hdr(skb);
474 struct sockaddr_in6 *sa = &addr->v6;
475
476 addr->v6.sin6_family = AF_INET6;
477 addr->v6.sin6_flowinfo = 0; /* FIXME */
478 addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
479
480 if (is_saddr) {
481 sa->sin6_port = sh->source;
482 sa->sin6_addr = ipv6_hdr(skb)->saddr;
483 } else {
484 sa->sin6_port = sh->dest;
485 sa->sin6_addr = ipv6_hdr(skb)->daddr;
486 }
487 }
488
489 /* Initialize an sctp_addr from a socket. */
sctp_v6_from_sk(union sctp_addr * addr,struct sock * sk)490 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
491 {
492 addr->v6.sin6_family = AF_INET6;
493 addr->v6.sin6_port = 0;
494 addr->v6.sin6_addr = sk->sk_v6_rcv_saddr;
495 }
496
497 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
sctp_v6_to_sk_saddr(union sctp_addr * addr,struct sock * sk)498 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
499 {
500 if (addr->sa.sa_family == AF_INET) {
501 sk->sk_v6_rcv_saddr.s6_addr32[0] = 0;
502 sk->sk_v6_rcv_saddr.s6_addr32[1] = 0;
503 sk->sk_v6_rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
504 sk->sk_v6_rcv_saddr.s6_addr32[3] =
505 addr->v4.sin_addr.s_addr;
506 } else {
507 sk->sk_v6_rcv_saddr = addr->v6.sin6_addr;
508 }
509 }
510
511 /* Initialize sk->sk_daddr from sctp_addr. */
sctp_v6_to_sk_daddr(union sctp_addr * addr,struct sock * sk)512 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
513 {
514 if (addr->sa.sa_family == AF_INET) {
515 sk->sk_v6_daddr.s6_addr32[0] = 0;
516 sk->sk_v6_daddr.s6_addr32[1] = 0;
517 sk->sk_v6_daddr.s6_addr32[2] = htonl(0x0000ffff);
518 sk->sk_v6_daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
519 } else {
520 sk->sk_v6_daddr = addr->v6.sin6_addr;
521 }
522 }
523
524 /* 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)525 static void sctp_v6_from_addr_param(union sctp_addr *addr,
526 union sctp_addr_param *param,
527 __be16 port, int iif)
528 {
529 addr->v6.sin6_family = AF_INET6;
530 addr->v6.sin6_port = port;
531 addr->v6.sin6_flowinfo = 0; /* BUG */
532 addr->v6.sin6_addr = param->v6.addr;
533 addr->v6.sin6_scope_id = iif;
534 }
535
536 /* Initialize an address parameter from a sctp_addr and return the length
537 * of the address parameter.
538 */
sctp_v6_to_addr_param(const union sctp_addr * addr,union sctp_addr_param * param)539 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
540 union sctp_addr_param *param)
541 {
542 int length = sizeof(struct sctp_ipv6addr_param);
543
544 param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
545 param->v6.param_hdr.length = htons(length);
546 param->v6.addr = addr->v6.sin6_addr;
547
548 return length;
549 }
550
551 /* Initialize a sctp_addr from struct in6_addr. */
sctp_v6_to_addr(union sctp_addr * addr,struct in6_addr * saddr,__be16 port)552 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
553 __be16 port)
554 {
555 addr->sa.sa_family = AF_INET6;
556 addr->v6.sin6_port = port;
557 addr->v6.sin6_flowinfo = 0;
558 addr->v6.sin6_addr = *saddr;
559 addr->v6.sin6_scope_id = 0;
560 }
561
__sctp_v6_cmp_addr(const union sctp_addr * addr1,const union sctp_addr * addr2)562 static int __sctp_v6_cmp_addr(const union sctp_addr *addr1,
563 const union sctp_addr *addr2)
564 {
565 if (addr1->sa.sa_family != addr2->sa.sa_family) {
566 if (addr1->sa.sa_family == AF_INET &&
567 addr2->sa.sa_family == AF_INET6 &&
568 ipv6_addr_v4mapped(&addr2->v6.sin6_addr) &&
569 addr2->v6.sin6_addr.s6_addr32[3] ==
570 addr1->v4.sin_addr.s_addr)
571 return 1;
572
573 if (addr2->sa.sa_family == AF_INET &&
574 addr1->sa.sa_family == AF_INET6 &&
575 ipv6_addr_v4mapped(&addr1->v6.sin6_addr) &&
576 addr1->v6.sin6_addr.s6_addr32[3] ==
577 addr2->v4.sin_addr.s_addr)
578 return 1;
579
580 return 0;
581 }
582
583 if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
584 return 0;
585
586 /* If this is a linklocal address, compare the scope_id. */
587 if ((ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) &&
588 addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
589 addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)
590 return 0;
591
592 return 1;
593 }
594
595 /* Compare addresses exactly.
596 * v4-mapped-v6 is also in consideration.
597 */
sctp_v6_cmp_addr(const union sctp_addr * addr1,const union sctp_addr * addr2)598 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
599 const union sctp_addr *addr2)
600 {
601 return __sctp_v6_cmp_addr(addr1, addr2) &&
602 addr1->v6.sin6_port == addr2->v6.sin6_port;
603 }
604
605 /* Initialize addr struct to INADDR_ANY. */
sctp_v6_inaddr_any(union sctp_addr * addr,__be16 port)606 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
607 {
608 memset(addr, 0x00, sizeof(union sctp_addr));
609 addr->v6.sin6_family = AF_INET6;
610 addr->v6.sin6_port = port;
611 }
612
613 /* Is this a wildcard address? */
sctp_v6_is_any(const union sctp_addr * addr)614 static int sctp_v6_is_any(const union sctp_addr *addr)
615 {
616 return ipv6_addr_any(&addr->v6.sin6_addr);
617 }
618
619 /* Should this be available for binding? */
sctp_v6_available(union sctp_addr * addr,struct sctp_sock * sp)620 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
621 {
622 int type;
623 struct net *net = sock_net(&sp->inet.sk);
624 const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
625
626 type = ipv6_addr_type(in6);
627 if (IPV6_ADDR_ANY == type)
628 return 1;
629 if (type == IPV6_ADDR_MAPPED) {
630 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
631 return 0;
632 sctp_v6_map_v4(addr);
633 return sctp_get_af_specific(AF_INET)->available(addr, sp);
634 }
635 if (!(type & IPV6_ADDR_UNICAST))
636 return 0;
637
638 return sp->inet.freebind || net->ipv6.sysctl.ip_nonlocal_bind ||
639 ipv6_chk_addr(net, in6, NULL, 0);
640 }
641
642 /* This function checks if the address is a valid address to be used for
643 * SCTP.
644 *
645 * Output:
646 * Return 0 - If the address is a non-unicast or an illegal address.
647 * Return 1 - If the address is a unicast.
648 */
sctp_v6_addr_valid(union sctp_addr * addr,struct sctp_sock * sp,const struct sk_buff * skb)649 static int sctp_v6_addr_valid(union sctp_addr *addr,
650 struct sctp_sock *sp,
651 const struct sk_buff *skb)
652 {
653 int ret = ipv6_addr_type(&addr->v6.sin6_addr);
654
655 /* Support v4-mapped-v6 address. */
656 if (ret == IPV6_ADDR_MAPPED) {
657 /* Note: This routine is used in input, so v4-mapped-v6
658 * are disallowed here when there is no sctp_sock.
659 */
660 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
661 return 0;
662 sctp_v6_map_v4(addr);
663 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
664 }
665
666 /* Is this a non-unicast address */
667 if (!(ret & IPV6_ADDR_UNICAST))
668 return 0;
669
670 return 1;
671 }
672
673 /* What is the scope of 'addr'? */
sctp_v6_scope(union sctp_addr * addr)674 static enum sctp_scope sctp_v6_scope(union sctp_addr *addr)
675 {
676 enum sctp_scope retval;
677 int v6scope;
678
679 /* The IPv6 scope is really a set of bit fields.
680 * See IFA_* in <net/if_inet6.h>. Map to a generic SCTP scope.
681 */
682
683 v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
684 switch (v6scope) {
685 case IFA_HOST:
686 retval = SCTP_SCOPE_LOOPBACK;
687 break;
688 case IFA_LINK:
689 retval = SCTP_SCOPE_LINK;
690 break;
691 case IFA_SITE:
692 retval = SCTP_SCOPE_PRIVATE;
693 break;
694 default:
695 retval = SCTP_SCOPE_GLOBAL;
696 break;
697 }
698
699 return retval;
700 }
701
702 /* 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)703 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
704 struct sctp_association *asoc,
705 bool kern)
706 {
707 struct sock *newsk;
708 struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
709 struct sctp6_sock *newsctp6sk;
710
711 newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot, kern);
712 if (!newsk)
713 goto out;
714
715 sock_init_data(NULL, newsk);
716
717 sctp_copy_sock(newsk, sk, asoc);
718 sock_reset_flag(sk, SOCK_ZAPPED);
719
720 newsctp6sk = (struct sctp6_sock *)newsk;
721 inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
722
723 sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
724
725 newnp = inet6_sk(newsk);
726
727 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
728 newnp->ipv6_mc_list = NULL;
729 newnp->ipv6_ac_list = NULL;
730 newnp->ipv6_fl_list = NULL;
731
732 sctp_v6_copy_ip_options(sk, newsk);
733
734 /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
735 * and getpeername().
736 */
737 sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
738
739 newsk->sk_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
740
741 sk_refcnt_debug_inc(newsk);
742
743 if (newsk->sk_prot->init(newsk)) {
744 sk_common_release(newsk);
745 newsk = NULL;
746 }
747
748 out:
749 return newsk;
750 }
751
752 /* Format a sockaddr for return to user space. This makes sure the return is
753 * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option.
754 */
sctp_v6_addr_to_user(struct sctp_sock * sp,union sctp_addr * addr)755 static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr)
756 {
757 if (sp->v4mapped) {
758 if (addr->sa.sa_family == AF_INET)
759 sctp_v4_map_v6(addr);
760 } else {
761 if (addr->sa.sa_family == AF_INET6 &&
762 ipv6_addr_v4mapped(&addr->v6.sin6_addr))
763 sctp_v6_map_v4(addr);
764 }
765
766 if (addr->sa.sa_family == AF_INET) {
767 memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
768 return sizeof(struct sockaddr_in);
769 }
770 return sizeof(struct sockaddr_in6);
771 }
772
773 /* Where did this skb come from? */
sctp_v6_skb_iif(const struct sk_buff * skb)774 static int sctp_v6_skb_iif(const struct sk_buff *skb)
775 {
776 return IP6CB(skb)->iif;
777 }
778
779 /* Was this packet marked by Explicit Congestion Notification? */
sctp_v6_is_ce(const struct sk_buff * skb)780 static int sctp_v6_is_ce(const struct sk_buff *skb)
781 {
782 return *((__u32 *)(ipv6_hdr(skb))) & (__force __u32)htonl(1 << 20);
783 }
784
785 /* Dump the v6 addr to the seq file. */
sctp_v6_seq_dump_addr(struct seq_file * seq,union sctp_addr * addr)786 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
787 {
788 seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
789 }
790
sctp_v6_ecn_capable(struct sock * sk)791 static void sctp_v6_ecn_capable(struct sock *sk)
792 {
793 inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
794 }
795
796 /* Initialize a PF_INET msgname from a ulpevent. */
sctp_inet6_event_msgname(struct sctp_ulpevent * event,char * msgname,int * addrlen)797 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
798 char *msgname, int *addrlen)
799 {
800 union sctp_addr *addr;
801 struct sctp_association *asoc;
802 union sctp_addr *paddr;
803
804 if (!msgname)
805 return;
806
807 addr = (union sctp_addr *)msgname;
808 asoc = event->asoc;
809 paddr = &asoc->peer.primary_addr;
810
811 if (paddr->sa.sa_family == AF_INET) {
812 addr->v4.sin_family = AF_INET;
813 addr->v4.sin_port = htons(asoc->peer.port);
814 addr->v4.sin_addr = paddr->v4.sin_addr;
815 } else {
816 addr->v6.sin6_family = AF_INET6;
817 addr->v6.sin6_flowinfo = 0;
818 if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
819 addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id;
820 else
821 addr->v6.sin6_scope_id = 0;
822 addr->v6.sin6_port = htons(asoc->peer.port);
823 addr->v6.sin6_addr = paddr->v6.sin6_addr;
824 }
825
826 *addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr);
827 }
828
829 /* Initialize a msg_name from an inbound skb. */
sctp_inet6_skb_msgname(struct sk_buff * skb,char * msgname,int * addr_len)830 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
831 int *addr_len)
832 {
833 union sctp_addr *addr;
834 struct sctphdr *sh;
835
836 if (!msgname)
837 return;
838
839 addr = (union sctp_addr *)msgname;
840 sh = sctp_hdr(skb);
841
842 if (ip_hdr(skb)->version == 4) {
843 addr->v4.sin_family = AF_INET;
844 addr->v4.sin_port = sh->source;
845 addr->v4.sin_addr.s_addr = ip_hdr(skb)->saddr;
846 } else {
847 addr->v6.sin6_family = AF_INET6;
848 addr->v6.sin6_flowinfo = 0;
849 addr->v6.sin6_port = sh->source;
850 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
851 if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
852 addr->v6.sin6_scope_id = sctp_v6_skb_iif(skb);
853 else
854 addr->v6.sin6_scope_id = 0;
855 }
856
857 *addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr);
858 }
859
860 /* Do we support this AF? */
sctp_inet6_af_supported(sa_family_t family,struct sctp_sock * sp)861 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
862 {
863 switch (family) {
864 case AF_INET6:
865 return 1;
866 /* v4-mapped-v6 addresses */
867 case AF_INET:
868 if (!__ipv6_only_sock(sctp_opt2sk(sp)))
869 return 1;
870 /* fallthru */
871 default:
872 return 0;
873 }
874 }
875
876 /* Address matching with wildcards allowed. This extra level
877 * of indirection lets us choose whether a PF_INET6 should
878 * disallow any v4 addresses if we so choose.
879 */
sctp_inet6_cmp_addr(const union sctp_addr * addr1,const union sctp_addr * addr2,struct sctp_sock * opt)880 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
881 const union sctp_addr *addr2,
882 struct sctp_sock *opt)
883 {
884 struct sock *sk = sctp_opt2sk(opt);
885 struct sctp_af *af1, *af2;
886
887 af1 = sctp_get_af_specific(addr1->sa.sa_family);
888 af2 = sctp_get_af_specific(addr2->sa.sa_family);
889
890 if (!af1 || !af2)
891 return 0;
892
893 /* If the socket is IPv6 only, v4 addrs will not match */
894 if (__ipv6_only_sock(sk) && af1 != af2)
895 return 0;
896
897 /* Today, wildcard AF_INET/AF_INET6. */
898 if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
899 return 1;
900
901 if (addr1->sa.sa_family == AF_INET && addr2->sa.sa_family == AF_INET)
902 return addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr;
903
904 return __sctp_v6_cmp_addr(addr1, addr2);
905 }
906
907 /* Verify that the provided sockaddr looks bindable. Common verification,
908 * has already been taken care of.
909 */
sctp_inet6_bind_verify(struct sctp_sock * opt,union sctp_addr * addr)910 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
911 {
912 struct sctp_af *af;
913
914 /* ASSERT: address family has already been verified. */
915 if (addr->sa.sa_family != AF_INET6)
916 af = sctp_get_af_specific(addr->sa.sa_family);
917 else {
918 int type = ipv6_addr_type(&addr->v6.sin6_addr);
919 struct net_device *dev;
920
921 if (type & IPV6_ADDR_LINKLOCAL) {
922 struct net *net;
923 if (!addr->v6.sin6_scope_id)
924 return 0;
925 net = sock_net(&opt->inet.sk);
926 rcu_read_lock();
927 dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id);
928 if (!dev || !(opt->inet.freebind ||
929 net->ipv6.sysctl.ip_nonlocal_bind ||
930 ipv6_chk_addr(net, &addr->v6.sin6_addr,
931 dev, 0))) {
932 rcu_read_unlock();
933 return 0;
934 }
935 rcu_read_unlock();
936 }
937
938 af = opt->pf->af;
939 }
940 return af->available(addr, opt);
941 }
942
943 /* Verify that the provided sockaddr looks sendable. Common verification,
944 * has already been taken care of.
945 */
sctp_inet6_send_verify(struct sctp_sock * opt,union sctp_addr * addr)946 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
947 {
948 struct sctp_af *af = NULL;
949
950 /* ASSERT: address family has already been verified. */
951 if (addr->sa.sa_family != AF_INET6)
952 af = sctp_get_af_specific(addr->sa.sa_family);
953 else {
954 int type = ipv6_addr_type(&addr->v6.sin6_addr);
955 struct net_device *dev;
956
957 if (type & IPV6_ADDR_LINKLOCAL) {
958 if (!addr->v6.sin6_scope_id)
959 return 0;
960 rcu_read_lock();
961 dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk),
962 addr->v6.sin6_scope_id);
963 rcu_read_unlock();
964 if (!dev)
965 return 0;
966 }
967 af = opt->pf->af;
968 }
969
970 return af != NULL;
971 }
972
973 /* Fill in Supported Address Type information for INIT and INIT-ACK
974 * chunks. Note: In the future, we may want to look at sock options
975 * to determine whether a PF_INET6 socket really wants to have IPV4
976 * addresses.
977 * Returns number of addresses supported.
978 */
sctp_inet6_supported_addrs(const struct sctp_sock * opt,__be16 * types)979 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
980 __be16 *types)
981 {
982 types[0] = SCTP_PARAM_IPV6_ADDRESS;
983 if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
984 types[1] = SCTP_PARAM_IPV4_ADDRESS;
985 return 2;
986 }
987 return 1;
988 }
989
990 /* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */
sctp_getname(struct socket * sock,struct sockaddr * uaddr,int peer)991 static int sctp_getname(struct socket *sock, struct sockaddr *uaddr,
992 int peer)
993 {
994 int rc;
995
996 rc = inet6_getname(sock, uaddr, peer);
997
998 if (rc < 0)
999 return rc;
1000
1001 rc = sctp_v6_addr_to_user(sctp_sk(sock->sk),
1002 (union sctp_addr *)uaddr);
1003
1004 return rc;
1005 }
1006
1007 static const struct proto_ops inet6_seqpacket_ops = {
1008 .family = PF_INET6,
1009 .owner = THIS_MODULE,
1010 .release = inet6_release,
1011 .bind = inet6_bind,
1012 .connect = sctp_inet_connect,
1013 .socketpair = sock_no_socketpair,
1014 .accept = inet_accept,
1015 .getname = sctp_getname,
1016 .poll = sctp_poll,
1017 .ioctl = inet6_ioctl,
1018 .gettstamp = sock_gettstamp,
1019 .listen = sctp_inet_listen,
1020 .shutdown = inet_shutdown,
1021 .setsockopt = sock_common_setsockopt,
1022 .getsockopt = sock_common_getsockopt,
1023 .sendmsg = inet_sendmsg,
1024 .recvmsg = inet_recvmsg,
1025 .mmap = sock_no_mmap,
1026 #ifdef CONFIG_COMPAT
1027 .compat_setsockopt = compat_sock_common_setsockopt,
1028 .compat_getsockopt = compat_sock_common_getsockopt,
1029 #endif
1030 };
1031
1032 static struct inet_protosw sctpv6_seqpacket_protosw = {
1033 .type = SOCK_SEQPACKET,
1034 .protocol = IPPROTO_SCTP,
1035 .prot = &sctpv6_prot,
1036 .ops = &inet6_seqpacket_ops,
1037 .flags = SCTP_PROTOSW_FLAG
1038 };
1039 static struct inet_protosw sctpv6_stream_protosw = {
1040 .type = SOCK_STREAM,
1041 .protocol = IPPROTO_SCTP,
1042 .prot = &sctpv6_prot,
1043 .ops = &inet6_seqpacket_ops,
1044 .flags = SCTP_PROTOSW_FLAG,
1045 };
1046
sctp6_rcv(struct sk_buff * skb)1047 static int sctp6_rcv(struct sk_buff *skb)
1048 {
1049 return sctp_rcv(skb) ? -1 : 0;
1050 }
1051
1052 static const struct inet6_protocol sctpv6_protocol = {
1053 .handler = sctp6_rcv,
1054 .err_handler = sctp_v6_err,
1055 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
1056 };
1057
1058 static struct sctp_af sctp_af_inet6 = {
1059 .sa_family = AF_INET6,
1060 .sctp_xmit = sctp_v6_xmit,
1061 .setsockopt = ipv6_setsockopt,
1062 .getsockopt = ipv6_getsockopt,
1063 .get_dst = sctp_v6_get_dst,
1064 .get_saddr = sctp_v6_get_saddr,
1065 .copy_addrlist = sctp_v6_copy_addrlist,
1066 .from_skb = sctp_v6_from_skb,
1067 .from_sk = sctp_v6_from_sk,
1068 .from_addr_param = sctp_v6_from_addr_param,
1069 .to_addr_param = sctp_v6_to_addr_param,
1070 .cmp_addr = sctp_v6_cmp_addr,
1071 .scope = sctp_v6_scope,
1072 .addr_valid = sctp_v6_addr_valid,
1073 .inaddr_any = sctp_v6_inaddr_any,
1074 .is_any = sctp_v6_is_any,
1075 .available = sctp_v6_available,
1076 .skb_iif = sctp_v6_skb_iif,
1077 .is_ce = sctp_v6_is_ce,
1078 .seq_dump_addr = sctp_v6_seq_dump_addr,
1079 .ecn_capable = sctp_v6_ecn_capable,
1080 .net_header_len = sizeof(struct ipv6hdr),
1081 .sockaddr_len = sizeof(struct sockaddr_in6),
1082 .ip_options_len = sctp_v6_ip_options_len,
1083 #ifdef CONFIG_COMPAT
1084 .compat_setsockopt = compat_ipv6_setsockopt,
1085 .compat_getsockopt = compat_ipv6_getsockopt,
1086 #endif
1087 };
1088
1089 static struct sctp_pf sctp_pf_inet6 = {
1090 .event_msgname = sctp_inet6_event_msgname,
1091 .skb_msgname = sctp_inet6_skb_msgname,
1092 .af_supported = sctp_inet6_af_supported,
1093 .cmp_addr = sctp_inet6_cmp_addr,
1094 .bind_verify = sctp_inet6_bind_verify,
1095 .send_verify = sctp_inet6_send_verify,
1096 .supported_addrs = sctp_inet6_supported_addrs,
1097 .create_accept_sk = sctp_v6_create_accept_sk,
1098 .addr_to_user = sctp_v6_addr_to_user,
1099 .to_sk_saddr = sctp_v6_to_sk_saddr,
1100 .to_sk_daddr = sctp_v6_to_sk_daddr,
1101 .copy_ip_options = sctp_v6_copy_ip_options,
1102 .af = &sctp_af_inet6,
1103 };
1104
1105 /* Initialize IPv6 support and register with socket layer. */
sctp_v6_pf_init(void)1106 void sctp_v6_pf_init(void)
1107 {
1108 /* Register the SCTP specific PF_INET6 functions. */
1109 sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1110
1111 /* Register the SCTP specific AF_INET6 functions. */
1112 sctp_register_af(&sctp_af_inet6);
1113 }
1114
sctp_v6_pf_exit(void)1115 void sctp_v6_pf_exit(void)
1116 {
1117 list_del(&sctp_af_inet6.list);
1118 }
1119
1120 /* Initialize IPv6 support and register with socket layer. */
sctp_v6_protosw_init(void)1121 int sctp_v6_protosw_init(void)
1122 {
1123 int rc;
1124
1125 rc = proto_register(&sctpv6_prot, 1);
1126 if (rc)
1127 return rc;
1128
1129 /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1130 inet6_register_protosw(&sctpv6_seqpacket_protosw);
1131 inet6_register_protosw(&sctpv6_stream_protosw);
1132
1133 return 0;
1134 }
1135
sctp_v6_protosw_exit(void)1136 void sctp_v6_protosw_exit(void)
1137 {
1138 inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1139 inet6_unregister_protosw(&sctpv6_stream_protosw);
1140 proto_unregister(&sctpv6_prot);
1141 }
1142
1143
1144 /* Register with inet6 layer. */
sctp_v6_add_protocol(void)1145 int sctp_v6_add_protocol(void)
1146 {
1147 /* Register notifier for inet6 address additions/deletions. */
1148 register_inet6addr_notifier(&sctp_inet6addr_notifier);
1149
1150 if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1151 return -EAGAIN;
1152
1153 return 0;
1154 }
1155
1156 /* Unregister with inet6 layer. */
sctp_v6_del_protocol(void)1157 void sctp_v6_del_protocol(void)
1158 {
1159 inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1160 unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1161 }
1162