1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* SCTP kernel implementation
3 * (C) Copyright IBM Corp. 2002, 2004
4 * Copyright (c) 2001 Nokia, Inc.
5 * Copyright (c) 2001 La Monte H.P. Yarroll
6 * Copyright (c) 2002-2003 Intel Corp.
7 *
8 * This file is part of the SCTP kernel implementation
9 *
10 * SCTP over IPv6.
11 *
12 * Please send any bug reports or fixes you make to the
13 * email address(es):
14 * lksctp developers <linux-sctp@vger.kernel.org>
15 *
16 * Written or modified by:
17 * Le Yanqun <yanqun.le@nokia.com>
18 * Hui Huang <hui.huang@nokia.com>
19 * La Monte H.P. Yarroll <piggy@acm.org>
20 * Sridhar Samudrala <sri@us.ibm.com>
21 * Jon Grimm <jgrimm@us.ibm.com>
22 * Ardelle Fan <ardelle.fan@intel.com>
23 *
24 * Based on:
25 * linux/net/ipv6/tcp_ipv6.c
26 */
27
28 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
29
30 #include <linux/module.h>
31 #include <linux/errno.h>
32 #include <linux/types.h>
33 #include <linux/socket.h>
34 #include <linux/sockios.h>
35 #include <linux/net.h>
36 #include <linux/in.h>
37 #include <linux/in6.h>
38 #include <linux/netdevice.h>
39 #include <linux/init.h>
40 #include <linux/ipsec.h>
41 #include <linux/slab.h>
42
43 #include <linux/ipv6.h>
44 #include <linux/icmpv6.h>
45 #include <linux/random.h>
46 #include <linux/seq_file.h>
47
48 #include <net/protocol.h>
49 #include <net/ndisc.h>
50 #include <net/ip.h>
51 #include <net/ipv6.h>
52 #include <net/transp_v6.h>
53 #include <net/addrconf.h>
54 #include <net/ip6_route.h>
55 #include <net/inet_common.h>
56 #include <net/inet_ecn.h>
57 #include <net/sctp/sctp.h>
58 #include <net/udp_tunnel.h>
59
60 #include <linux/uaccess.h>
61
62 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
63 union sctp_addr *s2);
64 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
65 __be16 port);
66 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
67 const union sctp_addr *addr2);
68
69 /* Event handler for inet6 address addition/deletion events.
70 * The sctp_local_addr_list needs to be protocted by a spin lock since
71 * multiple notifiers (say IPv4 and IPv6) may be running at the same
72 * time and thus corrupt the list.
73 * The reader side is protected with RCU.
74 */
75 static int sctp_inet6addr_event(struct notifier_block *this, unsigned long ev,
76 void *ptr)
77 {
78 struct inet6_ifaddr *ifa = (struct inet6_ifaddr *)ptr;
79 struct sctp_sockaddr_entry *addr = NULL;
80 struct sctp_sockaddr_entry *temp;
81 struct net *net = dev_net(ifa->idev->dev);
82 int found = 0;
83
84 switch (ev) {
85 case NETDEV_UP:
86 addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
87 if (addr) {
88 addr->a.v6.sin6_family = AF_INET6;
89 addr->a.v6.sin6_addr = ifa->addr;
90 addr->a.v6.sin6_scope_id = ifa->idev->dev->ifindex;
91 addr->valid = 1;
92 spin_lock_bh(&net->sctp.local_addr_lock);
93 list_add_tail_rcu(&addr->list, &net->sctp.local_addr_list);
94 sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_NEW);
95 spin_unlock_bh(&net->sctp.local_addr_lock);
96 }
97 break;
98 case NETDEV_DOWN:
99 spin_lock_bh(&net->sctp.local_addr_lock);
100 list_for_each_entry_safe(addr, temp,
101 &net->sctp.local_addr_list, list) {
102 if (addr->a.sa.sa_family == AF_INET6 &&
103 ipv6_addr_equal(&addr->a.v6.sin6_addr,
104 &ifa->addr) &&
105 addr->a.v6.sin6_scope_id == ifa->idev->dev->ifindex) {
106 sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL);
107 found = 1;
108 addr->valid = 0;
109 list_del_rcu(&addr->list);
110 break;
111 }
112 }
113 spin_unlock_bh(&net->sctp.local_addr_lock);
114 if (found)
115 kfree_rcu(addr, rcu);
116 break;
117 }
118
119 return NOTIFY_DONE;
120 }
121
122 static struct notifier_block sctp_inet6addr_notifier = {
123 .notifier_call = sctp_inet6addr_event,
124 };
125
126 static void sctp_v6_err_handle(struct sctp_transport *t, struct sk_buff *skb,
127 __u8 type, __u8 code, __u32 info)
128 {
129 struct sctp_association *asoc = t->asoc;
130 struct sock *sk = asoc->base.sk;
131 int err = 0;
132
133 switch (type) {
134 case ICMPV6_PKT_TOOBIG:
135 if (ip6_sk_accept_pmtu(sk))
136 sctp_icmp_frag_needed(sk, asoc, t, info);
137 return;
138 case ICMPV6_PARAMPROB:
139 if (ICMPV6_UNK_NEXTHDR == code) {
140 sctp_icmp_proto_unreachable(sk, asoc, t);
141 return;
142 }
143 break;
144 case NDISC_REDIRECT:
145 sctp_icmp_redirect(sk, t, skb);
146 return;
147 default:
148 break;
149 }
150
151 icmpv6_err_convert(type, code, &err);
152 if (!sock_owned_by_user(sk) && inet6_test_bit(RECVERR6, sk)) {
153 sk->sk_err = err;
154 sk_error_report(sk);
155 } else {
156 WRITE_ONCE(sk->sk_err_soft, err);
157 }
158 }
159
160 /* ICMP error handler. */
161 static int sctp_v6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
162 u8 type, u8 code, int offset, __be32 info)
163 {
164 struct net *net = dev_net(skb->dev);
165 struct sctp_transport *transport;
166 struct sctp_association *asoc;
167 __u16 saveip, savesctp;
168 struct sock *sk;
169
170 /* Fix up skb to look at the embedded net header. */
171 saveip = skb->network_header;
172 savesctp = skb->transport_header;
173 skb_reset_network_header(skb);
174 skb_set_transport_header(skb, offset);
175 sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &transport);
176 /* Put back, the original pointers. */
177 skb->network_header = saveip;
178 skb->transport_header = savesctp;
179 if (!sk) {
180 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS);
181 return -ENOENT;
182 }
183
184 sctp_v6_err_handle(transport, skb, type, code, ntohl(info));
185 sctp_err_finish(sk, transport);
186
187 return 0;
188 }
189
190 int sctp_udp_v6_err(struct sock *sk, struct sk_buff *skb)
191 {
192 struct net *net = dev_net(skb->dev);
193 struct sctp_association *asoc;
194 struct sctp_transport *t;
195 struct icmp6hdr *hdr;
196 __u32 info = 0;
197
198 skb->transport_header += sizeof(struct udphdr);
199 sk = sctp_err_lookup(net, AF_INET6, skb, sctp_hdr(skb), &asoc, &t);
200 if (!sk) {
201 __ICMP6_INC_STATS(net, __in6_dev_get(skb->dev), ICMP6_MIB_INERRORS);
202 return -ENOENT;
203 }
204
205 skb->transport_header -= sizeof(struct udphdr);
206 hdr = (struct icmp6hdr *)(skb_network_header(skb) - sizeof(struct icmp6hdr));
207 if (hdr->icmp6_type == NDISC_REDIRECT) {
208 /* can't be handled without outer ip6hdr known, leave it to udpv6_err */
209 sctp_err_finish(sk, t);
210 return 0;
211 }
212 if (hdr->icmp6_type == ICMPV6_PKT_TOOBIG)
213 info = ntohl(hdr->icmp6_mtu);
214 sctp_v6_err_handle(t, skb, hdr->icmp6_type, hdr->icmp6_code, info);
215
216 sctp_err_finish(sk, t);
217 return 1;
218 }
219
220 static int sctp_v6_xmit(struct sk_buff *skb, struct sctp_transport *t)
221 {
222 struct dst_entry *dst = dst_clone(t->dst);
223 struct flowi6 *fl6 = &t->fl.u.ip6;
224 struct sock *sk = skb->sk;
225 struct ipv6_pinfo *np = inet6_sk(sk);
226 __u8 tclass = np->tclass;
227 __be32 label;
228
229 pr_debug("%s: skb:%p, len:%d, src:%pI6 dst:%pI6\n", __func__, skb,
230 skb->len, &fl6->saddr, &fl6->daddr);
231
232 if (t->dscp & SCTP_DSCP_SET_MASK)
233 tclass = t->dscp & SCTP_DSCP_VAL_MASK;
234
235 if (INET_ECN_is_capable(tclass))
236 IP6_ECN_flow_xmit(sk, fl6->flowlabel);
237
238 if (!(t->param_flags & SPP_PMTUD_ENABLE))
239 skb->ignore_df = 1;
240
241 SCTP_INC_STATS(sock_net(sk), SCTP_MIB_OUTSCTPPACKS);
242
243 if (!t->encap_port || !sctp_sk(sk)->udp_port) {
244 int res;
245
246 skb_dst_set(skb, dst);
247 rcu_read_lock();
248 res = ip6_xmit(sk, skb, fl6, sk->sk_mark,
249 rcu_dereference(np->opt),
250 tclass, READ_ONCE(sk->sk_priority));
251 rcu_read_unlock();
252 return res;
253 }
254
255 if (skb_is_gso(skb))
256 skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL_CSUM;
257
258 skb->encapsulation = 1;
259 skb_reset_inner_mac_header(skb);
260 skb_reset_inner_transport_header(skb);
261 skb_set_inner_ipproto(skb, IPPROTO_SCTP);
262 label = ip6_make_flowlabel(sock_net(sk), skb, fl6->flowlabel, true, fl6);
263
264 return udp_tunnel6_xmit_skb(dst, sk, skb, NULL, &fl6->saddr,
265 &fl6->daddr, tclass, ip6_dst_hoplimit(dst),
266 label, sctp_sk(sk)->udp_port, t->encap_port, false);
267 }
268
269 /* Returns the dst cache entry for the given source and destination ip
270 * addresses.
271 */
272 static void sctp_v6_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
273 struct flowi *fl, struct sock *sk)
274 {
275 struct sctp_association *asoc = t->asoc;
276 struct dst_entry *dst = NULL;
277 struct flowi _fl;
278 struct flowi6 *fl6 = &_fl.u.ip6;
279 struct sctp_bind_addr *bp;
280 struct ipv6_pinfo *np = inet6_sk(sk);
281 struct sctp_sockaddr_entry *laddr;
282 union sctp_addr *daddr = &t->ipaddr;
283 union sctp_addr dst_saddr;
284 struct in6_addr *final_p, final;
285 enum sctp_scope scope;
286 __u8 matchlen = 0;
287
288 memset(&_fl, 0, sizeof(_fl));
289 fl6->daddr = daddr->v6.sin6_addr;
290 fl6->fl6_dport = daddr->v6.sin6_port;
291 fl6->flowi6_proto = IPPROTO_SCTP;
292 if (ipv6_addr_type(&daddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
293 fl6->flowi6_oif = daddr->v6.sin6_scope_id;
294 else if (asoc)
295 fl6->flowi6_oif = asoc->base.sk->sk_bound_dev_if;
296 if (t->flowlabel & SCTP_FLOWLABEL_SET_MASK)
297 fl6->flowlabel = htonl(t->flowlabel & SCTP_FLOWLABEL_VAL_MASK);
298
299 if (inet6_test_bit(SNDFLOW, sk) &&
300 (fl6->flowlabel & IPV6_FLOWLABEL_MASK)) {
301 struct ip6_flowlabel *flowlabel;
302
303 flowlabel = fl6_sock_lookup(sk, fl6->flowlabel);
304 if (IS_ERR(flowlabel))
305 goto out;
306 fl6_sock_release(flowlabel);
307 }
308
309 pr_debug("%s: dst=%pI6 ", __func__, &fl6->daddr);
310
311 if (asoc)
312 fl6->fl6_sport = htons(asoc->base.bind_addr.port);
313
314 if (saddr) {
315 fl6->saddr = saddr->v6.sin6_addr;
316 if (!fl6->fl6_sport)
317 fl6->fl6_sport = saddr->v6.sin6_port;
318
319 pr_debug("src=%pI6 - ", &fl6->saddr);
320 }
321
322 rcu_read_lock();
323 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
324 rcu_read_unlock();
325
326 dst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p);
327 if (!asoc || saddr) {
328 t->dst = dst;
329 memcpy(fl, &_fl, sizeof(_fl));
330 goto out;
331 }
332
333 bp = &asoc->base.bind_addr;
334 scope = sctp_scope(daddr);
335 /* ip6_dst_lookup has filled in the fl6->saddr for us. Check
336 * to see if we can use it.
337 */
338 if (!IS_ERR(dst)) {
339 /* Walk through the bind address list and look for a bind
340 * address that matches the source address of the returned dst.
341 */
342 sctp_v6_to_addr(&dst_saddr, &fl6->saddr, htons(bp->port));
343 rcu_read_lock();
344 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
345 if (!laddr->valid || laddr->state == SCTP_ADDR_DEL ||
346 (laddr->state != SCTP_ADDR_SRC &&
347 !asoc->src_out_of_asoc_ok))
348 continue;
349
350 /* Do not compare against v4 addrs */
351 if ((laddr->a.sa.sa_family == AF_INET6) &&
352 (sctp_v6_cmp_addr(&dst_saddr, &laddr->a))) {
353 rcu_read_unlock();
354 t->dst = dst;
355 memcpy(fl, &_fl, sizeof(_fl));
356 goto out;
357 }
358 }
359 rcu_read_unlock();
360 /* None of the bound addresses match the source address of the
361 * dst. So release it.
362 */
363 dst_release(dst);
364 dst = NULL;
365 }
366
367 /* Walk through the bind address list and try to get the
368 * best source address for a given destination.
369 */
370 rcu_read_lock();
371 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
372 struct dst_entry *bdst;
373 __u8 bmatchlen;
374
375 if (!laddr->valid ||
376 laddr->state != SCTP_ADDR_SRC ||
377 laddr->a.sa.sa_family != AF_INET6 ||
378 scope > sctp_scope(&laddr->a))
379 continue;
380
381 fl6->saddr = laddr->a.v6.sin6_addr;
382 fl6->fl6_sport = laddr->a.v6.sin6_port;
383 final_p = fl6_update_dst(fl6, rcu_dereference(np->opt), &final);
384 bdst = ip6_dst_lookup_flow(sock_net(sk), sk, fl6, final_p);
385
386 if (IS_ERR(bdst))
387 continue;
388
389 if (ipv6_chk_addr(dev_net(bdst->dev),
390 &laddr->a.v6.sin6_addr, bdst->dev, 1)) {
391 if (!IS_ERR_OR_NULL(dst))
392 dst_release(dst);
393 dst = bdst;
394 t->dst = dst;
395 memcpy(fl, &_fl, sizeof(_fl));
396 break;
397 }
398
399 bmatchlen = sctp_v6_addr_match_len(daddr, &laddr->a);
400 if (matchlen > bmatchlen) {
401 dst_release(bdst);
402 continue;
403 }
404
405 if (!IS_ERR_OR_NULL(dst))
406 dst_release(dst);
407 dst = bdst;
408 matchlen = bmatchlen;
409 t->dst = dst;
410 memcpy(fl, &_fl, sizeof(_fl));
411 }
412 rcu_read_unlock();
413
414 out:
415 if (!IS_ERR_OR_NULL(dst)) {
416 struct rt6_info *rt;
417
418 rt = dst_rt6_info(dst);
419 t->dst_cookie = rt6_get_cookie(rt);
420 pr_debug("rt6_dst:%pI6/%d rt6_src:%pI6\n",
421 &rt->rt6i_dst.addr, rt->rt6i_dst.plen,
422 &fl->u.ip6.saddr);
423 } else {
424 t->dst = NULL;
425 pr_debug("no route\n");
426 }
427 }
428
429 /* Returns the number of consecutive initial bits that match in the 2 ipv6
430 * addresses.
431 */
432 static inline int sctp_v6_addr_match_len(union sctp_addr *s1,
433 union sctp_addr *s2)
434 {
435 return ipv6_addr_diff(&s1->v6.sin6_addr, &s2->v6.sin6_addr);
436 }
437
438 /* Fills in the source address(saddr) based on the destination address(daddr)
439 * and asoc's bind address list.
440 */
441 static void sctp_v6_get_saddr(struct sctp_sock *sk,
442 struct sctp_transport *t,
443 struct flowi *fl)
444 {
445 struct flowi6 *fl6 = &fl->u.ip6;
446 union sctp_addr *saddr = &t->saddr;
447
448 pr_debug("%s: asoc:%p dst:%p\n", __func__, t->asoc, t->dst);
449
450 if (t->dst) {
451 saddr->v6.sin6_family = AF_INET6;
452 saddr->v6.sin6_addr = fl6->saddr;
453 }
454 }
455
456 /* Make a copy of all potential local addresses. */
457 static void sctp_v6_copy_addrlist(struct list_head *addrlist,
458 struct net_device *dev)
459 {
460 struct inet6_dev *in6_dev;
461 struct inet6_ifaddr *ifp;
462 struct sctp_sockaddr_entry *addr;
463
464 rcu_read_lock();
465 if ((in6_dev = __in6_dev_get(dev)) == NULL) {
466 rcu_read_unlock();
467 return;
468 }
469
470 read_lock_bh(&in6_dev->lock);
471 list_for_each_entry(ifp, &in6_dev->addr_list, if_list) {
472 /* Add the address to the local list. */
473 addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
474 if (addr) {
475 addr->a.v6.sin6_family = AF_INET6;
476 addr->a.v6.sin6_addr = ifp->addr;
477 addr->a.v6.sin6_scope_id = dev->ifindex;
478 addr->valid = 1;
479 INIT_LIST_HEAD(&addr->list);
480 list_add_tail(&addr->list, addrlist);
481 }
482 }
483
484 read_unlock_bh(&in6_dev->lock);
485 rcu_read_unlock();
486 }
487
488 /* Copy over any ip options */
489 static void sctp_v6_copy_ip_options(struct sock *sk, struct sock *newsk)
490 {
491 struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
492 struct ipv6_txoptions *opt;
493
494 newnp = inet6_sk(newsk);
495
496 rcu_read_lock();
497 opt = rcu_dereference(np->opt);
498 if (opt) {
499 opt = ipv6_dup_options(newsk, opt);
500 if (!opt)
501 pr_err("%s: Failed to copy ip options\n", __func__);
502 }
503 RCU_INIT_POINTER(newnp->opt, opt);
504 rcu_read_unlock();
505 }
506
507 /* Account for the IP options */
508 static int sctp_v6_ip_options_len(struct sock *sk)
509 {
510 struct ipv6_pinfo *np = inet6_sk(sk);
511 struct ipv6_txoptions *opt;
512 int len = 0;
513
514 rcu_read_lock();
515 opt = rcu_dereference(np->opt);
516 if (opt)
517 len = opt->opt_flen + opt->opt_nflen;
518
519 rcu_read_unlock();
520 return len;
521 }
522
523 /* Initialize a sockaddr_storage from in incoming skb. */
524 static void sctp_v6_from_skb(union sctp_addr *addr, struct sk_buff *skb,
525 int is_saddr)
526 {
527 /* Always called on head skb, so this is safe */
528 struct sctphdr *sh = sctp_hdr(skb);
529 struct sockaddr_in6 *sa = &addr->v6;
530
531 addr->v6.sin6_family = AF_INET6;
532 addr->v6.sin6_flowinfo = 0; /* FIXME */
533 addr->v6.sin6_scope_id = ((struct inet6_skb_parm *)skb->cb)->iif;
534
535 if (is_saddr) {
536 sa->sin6_port = sh->source;
537 sa->sin6_addr = ipv6_hdr(skb)->saddr;
538 } else {
539 sa->sin6_port = sh->dest;
540 sa->sin6_addr = ipv6_hdr(skb)->daddr;
541 }
542 }
543
544 /* Initialize an sctp_addr from a socket. */
545 static void sctp_v6_from_sk(union sctp_addr *addr, struct sock *sk)
546 {
547 addr->v6.sin6_family = AF_INET6;
548 addr->v6.sin6_port = 0;
549 addr->v6.sin6_addr = sk->sk_v6_rcv_saddr;
550 }
551
552 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
553 static void sctp_v6_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
554 {
555 if (addr->sa.sa_family == AF_INET) {
556 sk->sk_v6_rcv_saddr.s6_addr32[0] = 0;
557 sk->sk_v6_rcv_saddr.s6_addr32[1] = 0;
558 sk->sk_v6_rcv_saddr.s6_addr32[2] = htonl(0x0000ffff);
559 sk->sk_v6_rcv_saddr.s6_addr32[3] =
560 addr->v4.sin_addr.s_addr;
561 } else {
562 sk->sk_v6_rcv_saddr = addr->v6.sin6_addr;
563 }
564 }
565
566 /* Initialize sk->sk_daddr from sctp_addr. */
567 static void sctp_v6_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
568 {
569 if (addr->sa.sa_family == AF_INET) {
570 sk->sk_v6_daddr.s6_addr32[0] = 0;
571 sk->sk_v6_daddr.s6_addr32[1] = 0;
572 sk->sk_v6_daddr.s6_addr32[2] = htonl(0x0000ffff);
573 sk->sk_v6_daddr.s6_addr32[3] = addr->v4.sin_addr.s_addr;
574 } else {
575 sk->sk_v6_daddr = addr->v6.sin6_addr;
576 }
577 }
578
579 /* Initialize a sctp_addr from an address parameter. */
580 static bool sctp_v6_from_addr_param(union sctp_addr *addr,
581 union sctp_addr_param *param,
582 __be16 port, int iif)
583 {
584 if (ntohs(param->v6.param_hdr.length) < sizeof(struct sctp_ipv6addr_param))
585 return false;
586
587 addr->v6.sin6_family = AF_INET6;
588 addr->v6.sin6_port = port;
589 addr->v6.sin6_flowinfo = 0; /* BUG */
590 addr->v6.sin6_addr = param->v6.addr;
591 addr->v6.sin6_scope_id = iif;
592
593 return true;
594 }
595
596 /* Initialize an address parameter from a sctp_addr and return the length
597 * of the address parameter.
598 */
599 static int sctp_v6_to_addr_param(const union sctp_addr *addr,
600 union sctp_addr_param *param)
601 {
602 int length = sizeof(struct sctp_ipv6addr_param);
603
604 param->v6.param_hdr.type = SCTP_PARAM_IPV6_ADDRESS;
605 param->v6.param_hdr.length = htons(length);
606 param->v6.addr = addr->v6.sin6_addr;
607
608 return length;
609 }
610
611 /* Initialize a sctp_addr from struct in6_addr. */
612 static void sctp_v6_to_addr(union sctp_addr *addr, struct in6_addr *saddr,
613 __be16 port)
614 {
615 addr->sa.sa_family = AF_INET6;
616 addr->v6.sin6_port = port;
617 addr->v6.sin6_flowinfo = 0;
618 addr->v6.sin6_addr = *saddr;
619 addr->v6.sin6_scope_id = 0;
620 }
621
622 static int __sctp_v6_cmp_addr(const union sctp_addr *addr1,
623 const union sctp_addr *addr2)
624 {
625 if (addr1->sa.sa_family != addr2->sa.sa_family) {
626 if (addr1->sa.sa_family == AF_INET &&
627 addr2->sa.sa_family == AF_INET6 &&
628 ipv6_addr_v4mapped(&addr2->v6.sin6_addr) &&
629 addr2->v6.sin6_addr.s6_addr32[3] ==
630 addr1->v4.sin_addr.s_addr)
631 return 1;
632
633 if (addr2->sa.sa_family == AF_INET &&
634 addr1->sa.sa_family == AF_INET6 &&
635 ipv6_addr_v4mapped(&addr1->v6.sin6_addr) &&
636 addr1->v6.sin6_addr.s6_addr32[3] ==
637 addr2->v4.sin_addr.s_addr)
638 return 1;
639
640 return 0;
641 }
642
643 if (!ipv6_addr_equal(&addr1->v6.sin6_addr, &addr2->v6.sin6_addr))
644 return 0;
645
646 /* If this is a linklocal address, compare the scope_id. */
647 if ((ipv6_addr_type(&addr1->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL) &&
648 addr1->v6.sin6_scope_id && addr2->v6.sin6_scope_id &&
649 addr1->v6.sin6_scope_id != addr2->v6.sin6_scope_id)
650 return 0;
651
652 return 1;
653 }
654
655 /* Compare addresses exactly.
656 * v4-mapped-v6 is also in consideration.
657 */
658 static int sctp_v6_cmp_addr(const union sctp_addr *addr1,
659 const union sctp_addr *addr2)
660 {
661 return __sctp_v6_cmp_addr(addr1, addr2) &&
662 addr1->v6.sin6_port == addr2->v6.sin6_port;
663 }
664
665 /* Initialize addr struct to INADDR_ANY. */
666 static void sctp_v6_inaddr_any(union sctp_addr *addr, __be16 port)
667 {
668 memset(addr, 0x00, sizeof(union sctp_addr));
669 addr->v6.sin6_family = AF_INET6;
670 addr->v6.sin6_port = port;
671 }
672
673 /* Is this a wildcard address? */
674 static int sctp_v6_is_any(const union sctp_addr *addr)
675 {
676 return ipv6_addr_any(&addr->v6.sin6_addr);
677 }
678
679 /* Should this be available for binding? */
680 static int sctp_v6_available(union sctp_addr *addr, struct sctp_sock *sp)
681 {
682 const struct in6_addr *in6 = (const struct in6_addr *)&addr->v6.sin6_addr;
683 struct sock *sk = &sp->inet.sk;
684 struct net *net = sock_net(sk);
685 struct net_device *dev = NULL;
686 int type;
687
688 type = ipv6_addr_type(in6);
689 if (IPV6_ADDR_ANY == type)
690 return 1;
691 if (type == IPV6_ADDR_MAPPED) {
692 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
693 return 0;
694 sctp_v6_map_v4(addr);
695 return sctp_get_af_specific(AF_INET)->available(addr, sp);
696 }
697 if (!(type & IPV6_ADDR_UNICAST))
698 return 0;
699
700 if (sk->sk_bound_dev_if) {
701 dev = dev_get_by_index_rcu(net, sk->sk_bound_dev_if);
702 if (!dev)
703 return 0;
704 }
705
706 return ipv6_can_nonlocal_bind(net, &sp->inet) ||
707 ipv6_chk_addr(net, in6, dev, 0);
708 }
709
710 /* This function checks if the address is a valid address to be used for
711 * SCTP.
712 *
713 * Output:
714 * Return 0 - If the address is a non-unicast or an illegal address.
715 * Return 1 - If the address is a unicast.
716 */
717 static int sctp_v6_addr_valid(union sctp_addr *addr,
718 struct sctp_sock *sp,
719 const struct sk_buff *skb)
720 {
721 int ret = ipv6_addr_type(&addr->v6.sin6_addr);
722
723 /* Support v4-mapped-v6 address. */
724 if (ret == IPV6_ADDR_MAPPED) {
725 /* Note: This routine is used in input, so v4-mapped-v6
726 * are disallowed here when there is no sctp_sock.
727 */
728 if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
729 return 0;
730 sctp_v6_map_v4(addr);
731 return sctp_get_af_specific(AF_INET)->addr_valid(addr, sp, skb);
732 }
733
734 /* Is this a non-unicast address */
735 if (!(ret & IPV6_ADDR_UNICAST))
736 return 0;
737
738 return 1;
739 }
740
741 /* What is the scope of 'addr'? */
742 static enum sctp_scope sctp_v6_scope(union sctp_addr *addr)
743 {
744 enum sctp_scope retval;
745 int v6scope;
746
747 /* The IPv6 scope is really a set of bit fields.
748 * See IFA_* in <net/if_inet6.h>. Map to a generic SCTP scope.
749 */
750
751 v6scope = ipv6_addr_scope(&addr->v6.sin6_addr);
752 switch (v6scope) {
753 case IFA_HOST:
754 retval = SCTP_SCOPE_LOOPBACK;
755 break;
756 case IFA_LINK:
757 retval = SCTP_SCOPE_LINK;
758 break;
759 case IFA_SITE:
760 retval = SCTP_SCOPE_PRIVATE;
761 break;
762 default:
763 retval = SCTP_SCOPE_GLOBAL;
764 break;
765 }
766
767 return retval;
768 }
769
770 /* Create and initialize a new sk for the socket to be returned by accept(). */
771 static struct sock *sctp_v6_create_accept_sk(struct sock *sk,
772 struct sctp_association *asoc,
773 bool kern)
774 {
775 struct sock *newsk;
776 struct ipv6_pinfo *newnp, *np = inet6_sk(sk);
777 struct sctp6_sock *newsctp6sk;
778
779 newsk = sk_alloc(sock_net(sk), PF_INET6, GFP_KERNEL, sk->sk_prot, kern);
780 if (!newsk)
781 goto out;
782
783 sock_init_data(NULL, newsk);
784
785 sctp_copy_sock(newsk, sk, asoc);
786 sock_reset_flag(sk, SOCK_ZAPPED);
787
788 newsctp6sk = (struct sctp6_sock *)newsk;
789 inet_sk(newsk)->pinet6 = &newsctp6sk->inet6;
790
791 sctp_sk(newsk)->v4mapped = sctp_sk(sk)->v4mapped;
792
793 newnp = inet6_sk(newsk);
794
795 memcpy(newnp, np, sizeof(struct ipv6_pinfo));
796 newnp->ipv6_mc_list = NULL;
797 newnp->ipv6_ac_list = NULL;
798 newnp->ipv6_fl_list = NULL;
799
800 sctp_v6_copy_ip_options(sk, newsk);
801
802 /* Initialize sk's sport, dport, rcv_saddr and daddr for getsockname()
803 * and getpeername().
804 */
805 sctp_v6_to_sk_daddr(&asoc->peer.primary_addr, newsk);
806
807 newsk->sk_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
808
809 if (newsk->sk_prot->init(newsk)) {
810 sk_common_release(newsk);
811 newsk = NULL;
812 }
813
814 out:
815 return newsk;
816 }
817
818 /* Format a sockaddr for return to user space. This makes sure the return is
819 * AF_INET or AF_INET6 depending on the SCTP_I_WANT_MAPPED_V4_ADDR option.
820 */
821 static int sctp_v6_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr)
822 {
823 if (sp->v4mapped) {
824 if (addr->sa.sa_family == AF_INET)
825 sctp_v4_map_v6(addr);
826 } else {
827 if (addr->sa.sa_family == AF_INET6 &&
828 ipv6_addr_v4mapped(&addr->v6.sin6_addr))
829 sctp_v6_map_v4(addr);
830 }
831
832 if (addr->sa.sa_family == AF_INET) {
833 memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
834 return sizeof(struct sockaddr_in);
835 }
836 return sizeof(struct sockaddr_in6);
837 }
838
839 /* Where did this skb come from? */
840 static int sctp_v6_skb_iif(const struct sk_buff *skb)
841 {
842 return inet6_iif(skb);
843 }
844
845 static int sctp_v6_skb_sdif(const struct sk_buff *skb)
846 {
847 return inet6_sdif(skb);
848 }
849
850 /* Was this packet marked by Explicit Congestion Notification? */
851 static int sctp_v6_is_ce(const struct sk_buff *skb)
852 {
853 return *((__u32 *)(ipv6_hdr(skb))) & (__force __u32)htonl(1 << 20);
854 }
855
856 /* Dump the v6 addr to the seq file. */
857 static void sctp_v6_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
858 {
859 seq_printf(seq, "%pI6 ", &addr->v6.sin6_addr);
860 }
861
862 static void sctp_v6_ecn_capable(struct sock *sk)
863 {
864 inet6_sk(sk)->tclass |= INET_ECN_ECT_0;
865 }
866
867 /* Initialize a PF_INET msgname from a ulpevent. */
868 static void sctp_inet6_event_msgname(struct sctp_ulpevent *event,
869 char *msgname, int *addrlen)
870 {
871 union sctp_addr *addr;
872 struct sctp_association *asoc;
873 union sctp_addr *paddr;
874
875 if (!msgname)
876 return;
877
878 addr = (union sctp_addr *)msgname;
879 asoc = event->asoc;
880 paddr = &asoc->peer.primary_addr;
881
882 if (paddr->sa.sa_family == AF_INET) {
883 addr->v4.sin_family = AF_INET;
884 addr->v4.sin_port = htons(asoc->peer.port);
885 addr->v4.sin_addr = paddr->v4.sin_addr;
886 } else {
887 addr->v6.sin6_family = AF_INET6;
888 addr->v6.sin6_flowinfo = 0;
889 if (ipv6_addr_type(&paddr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
890 addr->v6.sin6_scope_id = paddr->v6.sin6_scope_id;
891 else
892 addr->v6.sin6_scope_id = 0;
893 addr->v6.sin6_port = htons(asoc->peer.port);
894 addr->v6.sin6_addr = paddr->v6.sin6_addr;
895 }
896
897 *addrlen = sctp_v6_addr_to_user(sctp_sk(asoc->base.sk), addr);
898 }
899
900 /* Initialize a msg_name from an inbound skb. */
901 static void sctp_inet6_skb_msgname(struct sk_buff *skb, char *msgname,
902 int *addr_len)
903 {
904 union sctp_addr *addr;
905 struct sctphdr *sh;
906
907 if (!msgname)
908 return;
909
910 addr = (union sctp_addr *)msgname;
911 sh = sctp_hdr(skb);
912
913 if (ip_hdr(skb)->version == 4) {
914 addr->v4.sin_family = AF_INET;
915 addr->v4.sin_port = sh->source;
916 addr->v4.sin_addr.s_addr = ip_hdr(skb)->saddr;
917 } else {
918 addr->v6.sin6_family = AF_INET6;
919 addr->v6.sin6_flowinfo = 0;
920 addr->v6.sin6_port = sh->source;
921 addr->v6.sin6_addr = ipv6_hdr(skb)->saddr;
922 if (ipv6_addr_type(&addr->v6.sin6_addr) & IPV6_ADDR_LINKLOCAL)
923 addr->v6.sin6_scope_id = sctp_v6_skb_iif(skb);
924 else
925 addr->v6.sin6_scope_id = 0;
926 }
927
928 *addr_len = sctp_v6_addr_to_user(sctp_sk(skb->sk), addr);
929 }
930
931 /* Do we support this AF? */
932 static int sctp_inet6_af_supported(sa_family_t family, struct sctp_sock *sp)
933 {
934 switch (family) {
935 case AF_INET6:
936 return 1;
937 /* v4-mapped-v6 addresses */
938 case AF_INET:
939 if (!ipv6_only_sock(sctp_opt2sk(sp)))
940 return 1;
941 fallthrough;
942 default:
943 return 0;
944 }
945 }
946
947 /* Address matching with wildcards allowed. This extra level
948 * of indirection lets us choose whether a PF_INET6 should
949 * disallow any v4 addresses if we so choose.
950 */
951 static int sctp_inet6_cmp_addr(const union sctp_addr *addr1,
952 const union sctp_addr *addr2,
953 struct sctp_sock *opt)
954 {
955 struct sock *sk = sctp_opt2sk(opt);
956 struct sctp_af *af1, *af2;
957
958 af1 = sctp_get_af_specific(addr1->sa.sa_family);
959 af2 = sctp_get_af_specific(addr2->sa.sa_family);
960
961 if (!af1 || !af2)
962 return 0;
963
964 /* If the socket is IPv6 only, v4 addrs will not match */
965 if (ipv6_only_sock(sk) && af1 != af2)
966 return 0;
967
968 /* Today, wildcard AF_INET/AF_INET6. */
969 if (sctp_is_any(sk, addr1) || sctp_is_any(sk, addr2))
970 return 1;
971
972 if (addr1->sa.sa_family == AF_INET && addr2->sa.sa_family == AF_INET)
973 return addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr;
974
975 return __sctp_v6_cmp_addr(addr1, addr2);
976 }
977
978 /* Verify that the provided sockaddr looks bindable. Common verification,
979 * has already been taken care of.
980 */
981 static int sctp_inet6_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
982 {
983 struct sctp_af *af;
984
985 /* ASSERT: address family has already been verified. */
986 if (addr->sa.sa_family != AF_INET6)
987 af = sctp_get_af_specific(addr->sa.sa_family);
988 else {
989 int type = ipv6_addr_type(&addr->v6.sin6_addr);
990 struct net_device *dev;
991
992 if (type & IPV6_ADDR_LINKLOCAL) {
993 struct net *net;
994 if (!addr->v6.sin6_scope_id)
995 return 0;
996 net = sock_net(&opt->inet.sk);
997 rcu_read_lock();
998 dev = dev_get_by_index_rcu(net, addr->v6.sin6_scope_id);
999 if (!dev || !(ipv6_can_nonlocal_bind(net, &opt->inet) ||
1000 ipv6_chk_addr(net, &addr->v6.sin6_addr,
1001 dev, 0))) {
1002 rcu_read_unlock();
1003 return 0;
1004 }
1005 rcu_read_unlock();
1006 }
1007
1008 af = opt->pf->af;
1009 }
1010 return af->available(addr, opt);
1011 }
1012
1013 /* Verify that the provided sockaddr looks sendable. Common verification,
1014 * has already been taken care of.
1015 */
1016 static int sctp_inet6_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
1017 {
1018 struct sctp_af *af = NULL;
1019
1020 /* ASSERT: address family has already been verified. */
1021 if (addr->sa.sa_family != AF_INET6)
1022 af = sctp_get_af_specific(addr->sa.sa_family);
1023 else {
1024 int type = ipv6_addr_type(&addr->v6.sin6_addr);
1025 struct net_device *dev;
1026
1027 if (type & IPV6_ADDR_LINKLOCAL) {
1028 if (!addr->v6.sin6_scope_id)
1029 return 0;
1030 rcu_read_lock();
1031 dev = dev_get_by_index_rcu(sock_net(&opt->inet.sk),
1032 addr->v6.sin6_scope_id);
1033 rcu_read_unlock();
1034 if (!dev)
1035 return 0;
1036 }
1037 af = opt->pf->af;
1038 }
1039
1040 return af != NULL;
1041 }
1042
1043 /* Fill in Supported Address Type information for INIT and INIT-ACK
1044 * chunks. Note: In the future, we may want to look at sock options
1045 * to determine whether a PF_INET6 socket really wants to have IPV4
1046 * addresses.
1047 * Returns number of addresses supported.
1048 */
1049 static int sctp_inet6_supported_addrs(const struct sctp_sock *opt,
1050 __be16 *types)
1051 {
1052 types[0] = SCTP_PARAM_IPV6_ADDRESS;
1053 if (!opt || !ipv6_only_sock(sctp_opt2sk(opt))) {
1054 types[1] = SCTP_PARAM_IPV4_ADDRESS;
1055 return 2;
1056 }
1057 return 1;
1058 }
1059
1060 /* Handle SCTP_I_WANT_MAPPED_V4_ADDR for getpeername() and getsockname() */
1061 static int sctp_getname(struct socket *sock, struct sockaddr *uaddr,
1062 int peer)
1063 {
1064 int rc;
1065
1066 rc = inet6_getname(sock, uaddr, peer);
1067
1068 if (rc < 0)
1069 return rc;
1070
1071 rc = sctp_v6_addr_to_user(sctp_sk(sock->sk),
1072 (union sctp_addr *)uaddr);
1073
1074 return rc;
1075 }
1076
1077 static const struct proto_ops inet6_seqpacket_ops = {
1078 .family = PF_INET6,
1079 .owner = THIS_MODULE,
1080 .release = inet6_release,
1081 .bind = inet6_bind,
1082 .connect = sctp_inet_connect,
1083 .socketpair = sock_no_socketpair,
1084 .accept = inet_accept,
1085 .getname = sctp_getname,
1086 .poll = sctp_poll,
1087 .ioctl = inet6_ioctl,
1088 .gettstamp = sock_gettstamp,
1089 .listen = sctp_inet_listen,
1090 .shutdown = inet_shutdown,
1091 .setsockopt = sock_common_setsockopt,
1092 .getsockopt = sock_common_getsockopt,
1093 .sendmsg = inet_sendmsg,
1094 .recvmsg = inet_recvmsg,
1095 .mmap = sock_no_mmap,
1096 #ifdef CONFIG_COMPAT
1097 .compat_ioctl = inet6_compat_ioctl,
1098 #endif
1099 };
1100
1101 static struct inet_protosw sctpv6_seqpacket_protosw = {
1102 .type = SOCK_SEQPACKET,
1103 .protocol = IPPROTO_SCTP,
1104 .prot = &sctpv6_prot,
1105 .ops = &inet6_seqpacket_ops,
1106 .flags = SCTP_PROTOSW_FLAG
1107 };
1108 static struct inet_protosw sctpv6_stream_protosw = {
1109 .type = SOCK_STREAM,
1110 .protocol = IPPROTO_SCTP,
1111 .prot = &sctpv6_prot,
1112 .ops = &inet6_seqpacket_ops,
1113 .flags = SCTP_PROTOSW_FLAG,
1114 };
1115
1116 static int sctp6_rcv(struct sk_buff *skb)
1117 {
1118 SCTP_INPUT_CB(skb)->encap_port = 0;
1119 return sctp_rcv(skb) ? -1 : 0;
1120 }
1121
1122 static const struct inet6_protocol sctpv6_protocol = {
1123 .handler = sctp6_rcv,
1124 .err_handler = sctp_v6_err,
1125 .flags = INET6_PROTO_NOPOLICY | INET6_PROTO_FINAL,
1126 };
1127
1128 static struct sctp_af sctp_af_inet6 = {
1129 .sa_family = AF_INET6,
1130 .sctp_xmit = sctp_v6_xmit,
1131 .setsockopt = ipv6_setsockopt,
1132 .getsockopt = ipv6_getsockopt,
1133 .get_dst = sctp_v6_get_dst,
1134 .get_saddr = sctp_v6_get_saddr,
1135 .copy_addrlist = sctp_v6_copy_addrlist,
1136 .from_skb = sctp_v6_from_skb,
1137 .from_sk = sctp_v6_from_sk,
1138 .from_addr_param = sctp_v6_from_addr_param,
1139 .to_addr_param = sctp_v6_to_addr_param,
1140 .cmp_addr = sctp_v6_cmp_addr,
1141 .scope = sctp_v6_scope,
1142 .addr_valid = sctp_v6_addr_valid,
1143 .inaddr_any = sctp_v6_inaddr_any,
1144 .is_any = sctp_v6_is_any,
1145 .available = sctp_v6_available,
1146 .skb_iif = sctp_v6_skb_iif,
1147 .skb_sdif = sctp_v6_skb_sdif,
1148 .is_ce = sctp_v6_is_ce,
1149 .seq_dump_addr = sctp_v6_seq_dump_addr,
1150 .ecn_capable = sctp_v6_ecn_capable,
1151 .net_header_len = sizeof(struct ipv6hdr),
1152 .sockaddr_len = sizeof(struct sockaddr_in6),
1153 .ip_options_len = sctp_v6_ip_options_len,
1154 };
1155
1156 static struct sctp_pf sctp_pf_inet6 = {
1157 .event_msgname = sctp_inet6_event_msgname,
1158 .skb_msgname = sctp_inet6_skb_msgname,
1159 .af_supported = sctp_inet6_af_supported,
1160 .cmp_addr = sctp_inet6_cmp_addr,
1161 .bind_verify = sctp_inet6_bind_verify,
1162 .send_verify = sctp_inet6_send_verify,
1163 .supported_addrs = sctp_inet6_supported_addrs,
1164 .create_accept_sk = sctp_v6_create_accept_sk,
1165 .addr_to_user = sctp_v6_addr_to_user,
1166 .to_sk_saddr = sctp_v6_to_sk_saddr,
1167 .to_sk_daddr = sctp_v6_to_sk_daddr,
1168 .copy_ip_options = sctp_v6_copy_ip_options,
1169 .af = &sctp_af_inet6,
1170 };
1171
1172 /* Initialize IPv6 support and register with socket layer. */
1173 void sctp_v6_pf_init(void)
1174 {
1175 /* Register the SCTP specific PF_INET6 functions. */
1176 sctp_register_pf(&sctp_pf_inet6, PF_INET6);
1177
1178 /* Register the SCTP specific AF_INET6 functions. */
1179 sctp_register_af(&sctp_af_inet6);
1180 }
1181
1182 void sctp_v6_pf_exit(void)
1183 {
1184 list_del(&sctp_af_inet6.list);
1185 }
1186
1187 /* Initialize IPv6 support and register with socket layer. */
1188 int sctp_v6_protosw_init(void)
1189 {
1190 int rc;
1191
1192 rc = proto_register(&sctpv6_prot, 1);
1193 if (rc)
1194 return rc;
1195
1196 /* Add SCTPv6(UDP and TCP style) to inetsw6 linked list. */
1197 inet6_register_protosw(&sctpv6_seqpacket_protosw);
1198 inet6_register_protosw(&sctpv6_stream_protosw);
1199
1200 return 0;
1201 }
1202
1203 void sctp_v6_protosw_exit(void)
1204 {
1205 inet6_unregister_protosw(&sctpv6_seqpacket_protosw);
1206 inet6_unregister_protosw(&sctpv6_stream_protosw);
1207 proto_unregister(&sctpv6_prot);
1208 }
1209
1210
1211 /* Register with inet6 layer. */
1212 int sctp_v6_add_protocol(void)
1213 {
1214 /* Register notifier for inet6 address additions/deletions. */
1215 register_inet6addr_notifier(&sctp_inet6addr_notifier);
1216
1217 if (inet6_add_protocol(&sctpv6_protocol, IPPROTO_SCTP) < 0)
1218 return -EAGAIN;
1219
1220 return 0;
1221 }
1222
1223 /* Unregister with inet6 layer. */
1224 void sctp_v6_del_protocol(void)
1225 {
1226 inet6_del_protocol(&sctpv6_protocol, IPPROTO_SCTP);
1227 unregister_inet6addr_notifier(&sctp_inet6addr_notifier);
1228 }
1229
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