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Linux/net/sctp/protocol.c

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  1 // SPDX-License-Identifier: GPL-2.0-or-later
  2 /* SCTP kernel implementation
  3  * (C) Copyright IBM Corp. 2001, 2004
  4  * Copyright (c) 1999-2000 Cisco, Inc.
  5  * Copyright (c) 1999-2001 Motorola, Inc.
  6  * Copyright (c) 2001 Intel Corp.
  7  * Copyright (c) 2001 Nokia, Inc.
  8  * Copyright (c) 2001 La Monte H.P. Yarroll
  9  *
 10  * This file is part of the SCTP kernel implementation
 11  *
 12  * Initialization/cleanup for SCTP protocol support.
 13  *
 14  * Please send any bug reports or fixes you make to the
 15  * email address(es):
 16  *    lksctp developers <linux-sctp@vger.kernel.org>
 17  *
 18  * Written or modified by:
 19  *    La Monte H.P. Yarroll <piggy@acm.org>
 20  *    Karl Knutson <karl@athena.chicago.il.us>
 21  *    Jon Grimm <jgrimm@us.ibm.com>
 22  *    Sridhar Samudrala <sri@us.ibm.com>
 23  *    Daisy Chang <daisyc@us.ibm.com>
 24  *    Ardelle Fan <ardelle.fan@intel.com>
 25  */
 26 
 27 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 28 
 29 #include <linux/module.h>
 30 #include <linux/init.h>
 31 #include <linux/netdevice.h>
 32 #include <linux/inetdevice.h>
 33 #include <linux/seq_file.h>
 34 #include <linux/memblock.h>
 35 #include <linux/highmem.h>
 36 #include <linux/swap.h>
 37 #include <linux/slab.h>
 38 #include <net/net_namespace.h>
 39 #include <net/protocol.h>
 40 #include <net/ip.h>
 41 #include <net/ipv6.h>
 42 #include <net/route.h>
 43 #include <net/sctp/sctp.h>
 44 #include <net/addrconf.h>
 45 #include <net/inet_common.h>
 46 #include <net/inet_ecn.h>
 47 #include <net/udp_tunnel.h>
 48 
 49 #define MAX_SCTP_PORT_HASH_ENTRIES (64 * 1024)
 50 
 51 /* Global data structures. */
 52 struct sctp_globals sctp_globals __read_mostly;
 53 
 54 struct idr sctp_assocs_id;
 55 DEFINE_SPINLOCK(sctp_assocs_id_lock);
 56 
 57 static struct sctp_pf *sctp_pf_inet6_specific;
 58 static struct sctp_pf *sctp_pf_inet_specific;
 59 static struct sctp_af *sctp_af_v4_specific;
 60 static struct sctp_af *sctp_af_v6_specific;
 61 
 62 struct kmem_cache *sctp_chunk_cachep __read_mostly;
 63 struct kmem_cache *sctp_bucket_cachep __read_mostly;
 64 
 65 long sysctl_sctp_mem[3];
 66 int sysctl_sctp_rmem[3];
 67 int sysctl_sctp_wmem[3];
 68 
 69 /* Private helper to extract ipv4 address and stash them in
 70  * the protocol structure.
 71  */
 72 static void sctp_v4_copy_addrlist(struct list_head *addrlist,
 73                                   struct net_device *dev)
 74 {
 75         struct in_device *in_dev;
 76         struct in_ifaddr *ifa;
 77         struct sctp_sockaddr_entry *addr;
 78 
 79         rcu_read_lock();
 80         if ((in_dev = __in_dev_get_rcu(dev)) == NULL) {
 81                 rcu_read_unlock();
 82                 return;
 83         }
 84 
 85         in_dev_for_each_ifa_rcu(ifa, in_dev) {
 86                 /* Add the address to the local list.  */
 87                 addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
 88                 if (addr) {
 89                         addr->a.v4.sin_family = AF_INET;
 90                         addr->a.v4.sin_addr.s_addr = ifa->ifa_local;
 91                         addr->valid = 1;
 92                         INIT_LIST_HEAD(&addr->list);
 93                         list_add_tail(&addr->list, addrlist);
 94                 }
 95         }
 96 
 97         rcu_read_unlock();
 98 }
 99 
100 /* Extract our IP addresses from the system and stash them in the
101  * protocol structure.
102  */
103 static void sctp_get_local_addr_list(struct net *net)
104 {
105         struct net_device *dev;
106         struct list_head *pos;
107         struct sctp_af *af;
108 
109         rcu_read_lock();
110         for_each_netdev_rcu(net, dev) {
111                 list_for_each(pos, &sctp_address_families) {
112                         af = list_entry(pos, struct sctp_af, list);
113                         af->copy_addrlist(&net->sctp.local_addr_list, dev);
114                 }
115         }
116         rcu_read_unlock();
117 }
118 
119 /* Free the existing local addresses.  */
120 static void sctp_free_local_addr_list(struct net *net)
121 {
122         struct sctp_sockaddr_entry *addr;
123         struct list_head *pos, *temp;
124 
125         list_for_each_safe(pos, temp, &net->sctp.local_addr_list) {
126                 addr = list_entry(pos, struct sctp_sockaddr_entry, list);
127                 list_del(pos);
128                 kfree(addr);
129         }
130 }
131 
132 /* Copy the local addresses which are valid for 'scope' into 'bp'.  */
133 int sctp_copy_local_addr_list(struct net *net, struct sctp_bind_addr *bp,
134                               enum sctp_scope scope, gfp_t gfp, int copy_flags)
135 {
136         struct sctp_sockaddr_entry *addr;
137         union sctp_addr laddr;
138         int error = 0;
139 
140         rcu_read_lock();
141         list_for_each_entry_rcu(addr, &net->sctp.local_addr_list, list) {
142                 if (!addr->valid)
143                         continue;
144                 if (!sctp_in_scope(net, &addr->a, scope))
145                         continue;
146 
147                 /* Now that the address is in scope, check to see if
148                  * the address type is really supported by the local
149                  * sock as well as the remote peer.
150                  */
151                 if (addr->a.sa.sa_family == AF_INET &&
152                     (!(copy_flags & SCTP_ADDR4_ALLOWED) ||
153                      !(copy_flags & SCTP_ADDR4_PEERSUPP)))
154                         continue;
155                 if (addr->a.sa.sa_family == AF_INET6 &&
156                     (!(copy_flags & SCTP_ADDR6_ALLOWED) ||
157                      !(copy_flags & SCTP_ADDR6_PEERSUPP)))
158                         continue;
159 
160                 laddr = addr->a;
161                 /* also works for setting ipv6 address port */
162                 laddr.v4.sin_port = htons(bp->port);
163                 if (sctp_bind_addr_state(bp, &laddr) != -1)
164                         continue;
165 
166                 error = sctp_add_bind_addr(bp, &addr->a, sizeof(addr->a),
167                                            SCTP_ADDR_SRC, GFP_ATOMIC);
168                 if (error)
169                         break;
170         }
171 
172         rcu_read_unlock();
173         return error;
174 }
175 
176 /* Copy over any ip options */
177 static void sctp_v4_copy_ip_options(struct sock *sk, struct sock *newsk)
178 {
179         struct inet_sock *newinet, *inet = inet_sk(sk);
180         struct ip_options_rcu *inet_opt, *newopt = NULL;
181 
182         newinet = inet_sk(newsk);
183 
184         rcu_read_lock();
185         inet_opt = rcu_dereference(inet->inet_opt);
186         if (inet_opt) {
187                 newopt = sock_kmalloc(newsk, sizeof(*inet_opt) +
188                                       inet_opt->opt.optlen, GFP_ATOMIC);
189                 if (newopt)
190                         memcpy(newopt, inet_opt, sizeof(*inet_opt) +
191                                inet_opt->opt.optlen);
192                 else
193                         pr_err("%s: Failed to copy ip options\n", __func__);
194         }
195         RCU_INIT_POINTER(newinet->inet_opt, newopt);
196         rcu_read_unlock();
197 }
198 
199 /* Account for the IP options */
200 static int sctp_v4_ip_options_len(struct sock *sk)
201 {
202         struct inet_sock *inet = inet_sk(sk);
203         struct ip_options_rcu *inet_opt;
204         int len = 0;
205 
206         rcu_read_lock();
207         inet_opt = rcu_dereference(inet->inet_opt);
208         if (inet_opt)
209                 len = inet_opt->opt.optlen;
210 
211         rcu_read_unlock();
212         return len;
213 }
214 
215 /* Initialize a sctp_addr from in incoming skb.  */
216 static void sctp_v4_from_skb(union sctp_addr *addr, struct sk_buff *skb,
217                              int is_saddr)
218 {
219         /* Always called on head skb, so this is safe */
220         struct sctphdr *sh = sctp_hdr(skb);
221         struct sockaddr_in *sa = &addr->v4;
222 
223         addr->v4.sin_family = AF_INET;
224 
225         if (is_saddr) {
226                 sa->sin_port = sh->source;
227                 sa->sin_addr.s_addr = ip_hdr(skb)->saddr;
228         } else {
229                 sa->sin_port = sh->dest;
230                 sa->sin_addr.s_addr = ip_hdr(skb)->daddr;
231         }
232         memset(sa->sin_zero, 0, sizeof(sa->sin_zero));
233 }
234 
235 /* Initialize an sctp_addr from a socket. */
236 static void sctp_v4_from_sk(union sctp_addr *addr, struct sock *sk)
237 {
238         addr->v4.sin_family = AF_INET;
239         addr->v4.sin_port = 0;
240         addr->v4.sin_addr.s_addr = inet_sk(sk)->inet_rcv_saddr;
241         memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
242 }
243 
244 /* Initialize sk->sk_rcv_saddr from sctp_addr. */
245 static void sctp_v4_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
246 {
247         inet_sk(sk)->inet_rcv_saddr = addr->v4.sin_addr.s_addr;
248 }
249 
250 /* Initialize sk->sk_daddr from sctp_addr. */
251 static void sctp_v4_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
252 {
253         inet_sk(sk)->inet_daddr = addr->v4.sin_addr.s_addr;
254 }
255 
256 /* Initialize a sctp_addr from an address parameter. */
257 static void sctp_v4_from_addr_param(union sctp_addr *addr,
258                                     union sctp_addr_param *param,
259                                     __be16 port, int iif)
260 {
261         addr->v4.sin_family = AF_INET;
262         addr->v4.sin_port = port;
263         addr->v4.sin_addr.s_addr = param->v4.addr.s_addr;
264         memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
265 }
266 
267 /* Initialize an address parameter from a sctp_addr and return the length
268  * of the address parameter.
269  */
270 static int sctp_v4_to_addr_param(const union sctp_addr *addr,
271                                  union sctp_addr_param *param)
272 {
273         int length = sizeof(struct sctp_ipv4addr_param);
274 
275         param->v4.param_hdr.type = SCTP_PARAM_IPV4_ADDRESS;
276         param->v4.param_hdr.length = htons(length);
277         param->v4.addr.s_addr = addr->v4.sin_addr.s_addr;
278 
279         return length;
280 }
281 
282 /* Initialize a sctp_addr from a dst_entry. */
283 static void sctp_v4_dst_saddr(union sctp_addr *saddr, struct flowi4 *fl4,
284                               __be16 port)
285 {
286         saddr->v4.sin_family = AF_INET;
287         saddr->v4.sin_port = port;
288         saddr->v4.sin_addr.s_addr = fl4->saddr;
289         memset(saddr->v4.sin_zero, 0, sizeof(saddr->v4.sin_zero));
290 }
291 
292 /* Compare two addresses exactly. */
293 static int sctp_v4_cmp_addr(const union sctp_addr *addr1,
294                             const union sctp_addr *addr2)
295 {
296         if (addr1->sa.sa_family != addr2->sa.sa_family)
297                 return 0;
298         if (addr1->v4.sin_port != addr2->v4.sin_port)
299                 return 0;
300         if (addr1->v4.sin_addr.s_addr != addr2->v4.sin_addr.s_addr)
301                 return 0;
302 
303         return 1;
304 }
305 
306 /* Initialize addr struct to INADDR_ANY. */
307 static void sctp_v4_inaddr_any(union sctp_addr *addr, __be16 port)
308 {
309         addr->v4.sin_family = AF_INET;
310         addr->v4.sin_addr.s_addr = htonl(INADDR_ANY);
311         addr->v4.sin_port = port;
312         memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
313 }
314 
315 /* Is this a wildcard address? */
316 static int sctp_v4_is_any(const union sctp_addr *addr)
317 {
318         return htonl(INADDR_ANY) == addr->v4.sin_addr.s_addr;
319 }
320 
321 /* This function checks if the address is a valid address to be used for
322  * SCTP binding.
323  *
324  * Output:
325  * Return 0 - If the address is a non-unicast or an illegal address.
326  * Return 1 - If the address is a unicast.
327  */
328 static int sctp_v4_addr_valid(union sctp_addr *addr,
329                               struct sctp_sock *sp,
330                               const struct sk_buff *skb)
331 {
332         /* IPv4 addresses not allowed */
333         if (sp && ipv6_only_sock(sctp_opt2sk(sp)))
334                 return 0;
335 
336         /* Is this a non-unicast address or a unusable SCTP address? */
337         if (IS_IPV4_UNUSABLE_ADDRESS(addr->v4.sin_addr.s_addr))
338                 return 0;
339 
340         /* Is this a broadcast address? */
341         if (skb && skb_rtable(skb)->rt_flags & RTCF_BROADCAST)
342                 return 0;
343 
344         return 1;
345 }
346 
347 /* Should this be available for binding?   */
348 static int sctp_v4_available(union sctp_addr *addr, struct sctp_sock *sp)
349 {
350         struct net *net = sock_net(&sp->inet.sk);
351         int ret = inet_addr_type(net, addr->v4.sin_addr.s_addr);
352 
353 
354         if (addr->v4.sin_addr.s_addr != htonl(INADDR_ANY) &&
355            ret != RTN_LOCAL &&
356            !sp->inet.freebind &&
357            !net->ipv4.sysctl_ip_nonlocal_bind)
358                 return 0;
359 
360         if (ipv6_only_sock(sctp_opt2sk(sp)))
361                 return 0;
362 
363         return 1;
364 }
365 
366 /* Checking the loopback, private and other address scopes as defined in
367  * RFC 1918.   The IPv4 scoping is based on the draft for SCTP IPv4
368  * scoping <draft-stewart-tsvwg-sctp-ipv4-00.txt>.
369  *
370  * Level 0 - unusable SCTP addresses
371  * Level 1 - loopback address
372  * Level 2 - link-local addresses
373  * Level 3 - private addresses.
374  * Level 4 - global addresses
375  * For INIT and INIT-ACK address list, let L be the level of
376  * requested destination address, sender and receiver
377  * SHOULD include all of its addresses with level greater
378  * than or equal to L.
379  *
380  * IPv4 scoping can be controlled through sysctl option
381  * net.sctp.addr_scope_policy
382  */
383 static enum sctp_scope sctp_v4_scope(union sctp_addr *addr)
384 {
385         enum sctp_scope retval;
386 
387         /* Check for unusable SCTP addresses. */
388         if (IS_IPV4_UNUSABLE_ADDRESS(addr->v4.sin_addr.s_addr)) {
389                 retval =  SCTP_SCOPE_UNUSABLE;
390         } else if (ipv4_is_loopback(addr->v4.sin_addr.s_addr)) {
391                 retval = SCTP_SCOPE_LOOPBACK;
392         } else if (ipv4_is_linklocal_169(addr->v4.sin_addr.s_addr)) {
393                 retval = SCTP_SCOPE_LINK;
394         } else if (ipv4_is_private_10(addr->v4.sin_addr.s_addr) ||
395                    ipv4_is_private_172(addr->v4.sin_addr.s_addr) ||
396                    ipv4_is_private_192(addr->v4.sin_addr.s_addr)) {
397                 retval = SCTP_SCOPE_PRIVATE;
398         } else {
399                 retval = SCTP_SCOPE_GLOBAL;
400         }
401 
402         return retval;
403 }
404 
405 /* Returns a valid dst cache entry for the given source and destination ip
406  * addresses. If an association is passed, trys to get a dst entry with a
407  * source address that matches an address in the bind address list.
408  */
409 static void sctp_v4_get_dst(struct sctp_transport *t, union sctp_addr *saddr,
410                                 struct flowi *fl, struct sock *sk)
411 {
412         struct sctp_association *asoc = t->asoc;
413         struct rtable *rt;
414         struct flowi _fl;
415         struct flowi4 *fl4 = &_fl.u.ip4;
416         struct sctp_bind_addr *bp;
417         struct sctp_sockaddr_entry *laddr;
418         struct dst_entry *dst = NULL;
419         union sctp_addr *daddr = &t->ipaddr;
420         union sctp_addr dst_saddr;
421         __u8 tos = inet_sk(sk)->tos;
422 
423         if (t->dscp & SCTP_DSCP_SET_MASK)
424                 tos = t->dscp & SCTP_DSCP_VAL_MASK;
425         memset(&_fl, 0x0, sizeof(_fl));
426         fl4->daddr  = daddr->v4.sin_addr.s_addr;
427         fl4->fl4_dport = daddr->v4.sin_port;
428         fl4->flowi4_proto = IPPROTO_SCTP;
429         if (asoc) {
430                 fl4->flowi4_tos = RT_CONN_FLAGS_TOS(asoc->base.sk, tos);
431                 fl4->flowi4_oif = asoc->base.sk->sk_bound_dev_if;
432                 fl4->fl4_sport = htons(asoc->base.bind_addr.port);
433         }
434         if (saddr) {
435                 fl4->saddr = saddr->v4.sin_addr.s_addr;
436                 if (!fl4->fl4_sport)
437                         fl4->fl4_sport = saddr->v4.sin_port;
438         }
439 
440         pr_debug("%s: dst:%pI4, src:%pI4 - ", __func__, &fl4->daddr,
441                  &fl4->saddr);
442 
443         rt = ip_route_output_key(sock_net(sk), fl4);
444         if (!IS_ERR(rt)) {
445                 dst = &rt->dst;
446                 t->dst = dst;
447                 memcpy(fl, &_fl, sizeof(_fl));
448         }
449 
450         /* If there is no association or if a source address is passed, no
451          * more validation is required.
452          */
453         if (!asoc || saddr)
454                 goto out;
455 
456         bp = &asoc->base.bind_addr;
457 
458         if (dst) {
459                 /* Walk through the bind address list and look for a bind
460                  * address that matches the source address of the returned dst.
461                  */
462                 sctp_v4_dst_saddr(&dst_saddr, fl4, htons(bp->port));
463                 rcu_read_lock();
464                 list_for_each_entry_rcu(laddr, &bp->address_list, list) {
465                         if (!laddr->valid || (laddr->state == SCTP_ADDR_DEL) ||
466                             (laddr->state != SCTP_ADDR_SRC &&
467                             !asoc->src_out_of_asoc_ok))
468                                 continue;
469                         if (sctp_v4_cmp_addr(&dst_saddr, &laddr->a))
470                                 goto out_unlock;
471                 }
472                 rcu_read_unlock();
473 
474                 /* None of the bound addresses match the source address of the
475                  * dst. So release it.
476                  */
477                 dst_release(dst);
478                 dst = NULL;
479         }
480 
481         /* Walk through the bind address list and try to get a dst that
482          * matches a bind address as the source address.
483          */
484         rcu_read_lock();
485         list_for_each_entry_rcu(laddr, &bp->address_list, list) {
486                 struct net_device *odev;
487 
488                 if (!laddr->valid)
489                         continue;
490                 if (laddr->state != SCTP_ADDR_SRC ||
491                     AF_INET != laddr->a.sa.sa_family)
492                         continue;
493 
494                 fl4->fl4_sport = laddr->a.v4.sin_port;
495                 flowi4_update_output(fl4,
496                                      asoc->base.sk->sk_bound_dev_if,
497                                      RT_CONN_FLAGS_TOS(asoc->base.sk, tos),
498                                      daddr->v4.sin_addr.s_addr,
499                                      laddr->a.v4.sin_addr.s_addr);
500 
501                 rt = ip_route_output_key(sock_net(sk), fl4);
502                 if (IS_ERR(rt))
503                         continue;
504 
505                 /* Ensure the src address belongs to the output
506                  * interface.
507                  */
508                 odev = __ip_dev_find(sock_net(sk), laddr->a.v4.sin_addr.s_addr,
509                                      false);
510                 if (!odev || odev->ifindex != fl4->flowi4_oif) {
511                         if (!dst) {
512                                 dst = &rt->dst;
513                                 t->dst = dst;
514                                 memcpy(fl, &_fl, sizeof(_fl));
515                         } else {
516                                 dst_release(&rt->dst);
517                         }
518                         continue;
519                 }
520 
521                 dst_release(dst);
522                 dst = &rt->dst;
523                 t->dst = dst;
524                 memcpy(fl, &_fl, sizeof(_fl));
525                 break;
526         }
527 
528 out_unlock:
529         rcu_read_unlock();
530 out:
531         if (dst) {
532                 pr_debug("rt_dst:%pI4, rt_src:%pI4\n",
533                          &fl->u.ip4.daddr, &fl->u.ip4.saddr);
534         } else {
535                 t->dst = NULL;
536                 pr_debug("no route\n");
537         }
538 }
539 
540 /* For v4, the source address is cached in the route entry(dst). So no need
541  * to cache it separately and hence this is an empty routine.
542  */
543 static void sctp_v4_get_saddr(struct sctp_sock *sk,
544                               struct sctp_transport *t,
545                               struct flowi *fl)
546 {
547         union sctp_addr *saddr = &t->saddr;
548         struct rtable *rt = (struct rtable *)t->dst;
549 
550         if (rt) {
551                 saddr->v4.sin_family = AF_INET;
552                 saddr->v4.sin_addr.s_addr = fl->u.ip4.saddr;
553         }
554 }
555 
556 /* What interface did this skb arrive on? */
557 static int sctp_v4_skb_iif(const struct sk_buff *skb)
558 {
559         return inet_iif(skb);
560 }
561 
562 /* Was this packet marked by Explicit Congestion Notification? */
563 static int sctp_v4_is_ce(const struct sk_buff *skb)
564 {
565         return INET_ECN_is_ce(ip_hdr(skb)->tos);
566 }
567 
568 /* Create and initialize a new sk for the socket returned by accept(). */
569 static struct sock *sctp_v4_create_accept_sk(struct sock *sk,
570                                              struct sctp_association *asoc,
571                                              bool kern)
572 {
573         struct sock *newsk = sk_alloc(sock_net(sk), PF_INET, GFP_KERNEL,
574                         sk->sk_prot, kern);
575         struct inet_sock *newinet;
576 
577         if (!newsk)
578                 goto out;
579 
580         sock_init_data(NULL, newsk);
581 
582         sctp_copy_sock(newsk, sk, asoc);
583         sock_reset_flag(newsk, SOCK_ZAPPED);
584 
585         sctp_v4_copy_ip_options(sk, newsk);
586 
587         newinet = inet_sk(newsk);
588 
589         newinet->inet_daddr = asoc->peer.primary_addr.v4.sin_addr.s_addr;
590 
591         sk_refcnt_debug_inc(newsk);
592 
593         if (newsk->sk_prot->init(newsk)) {
594                 sk_common_release(newsk);
595                 newsk = NULL;
596         }
597 
598 out:
599         return newsk;
600 }
601 
602 static int sctp_v4_addr_to_user(struct sctp_sock *sp, union sctp_addr *addr)
603 {
604         /* No address mapping for V4 sockets */
605         memset(addr->v4.sin_zero, 0, sizeof(addr->v4.sin_zero));
606         return sizeof(struct sockaddr_in);
607 }
608 
609 /* Dump the v4 addr to the seq file. */
610 static void sctp_v4_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
611 {
612         seq_printf(seq, "%pI4 ", &addr->v4.sin_addr);
613 }
614 
615 static void sctp_v4_ecn_capable(struct sock *sk)
616 {
617         INET_ECN_xmit(sk);
618 }
619 
620 static void sctp_addr_wq_timeout_handler(struct timer_list *t)
621 {
622         struct net *net = from_timer(net, t, sctp.addr_wq_timer);
623         struct sctp_sockaddr_entry *addrw, *temp;
624         struct sctp_sock *sp;
625 
626         spin_lock_bh(&net->sctp.addr_wq_lock);
627 
628         list_for_each_entry_safe(addrw, temp, &net->sctp.addr_waitq, list) {
629                 pr_debug("%s: the first ent in wq:%p is addr:%pISc for cmd:%d at "
630                          "entry:%p\n", __func__, &net->sctp.addr_waitq, &addrw->a.sa,
631                          addrw->state, addrw);
632 
633 #if IS_ENABLED(CONFIG_IPV6)
634                 /* Now we send an ASCONF for each association */
635                 /* Note. we currently don't handle link local IPv6 addressees */
636                 if (addrw->a.sa.sa_family == AF_INET6) {
637                         struct in6_addr *in6;
638 
639                         if (ipv6_addr_type(&addrw->a.v6.sin6_addr) &
640                             IPV6_ADDR_LINKLOCAL)
641                                 goto free_next;
642 
643                         in6 = (struct in6_addr *)&addrw->a.v6.sin6_addr;
644                         if (ipv6_chk_addr(net, in6, NULL, 0) == 0 &&
645                             addrw->state == SCTP_ADDR_NEW) {
646                                 unsigned long timeo_val;
647 
648                                 pr_debug("%s: this is on DAD, trying %d sec "
649                                          "later\n", __func__,
650                                          SCTP_ADDRESS_TICK_DELAY);
651 
652                                 timeo_val = jiffies;
653                                 timeo_val += msecs_to_jiffies(SCTP_ADDRESS_TICK_DELAY);
654                                 mod_timer(&net->sctp.addr_wq_timer, timeo_val);
655                                 break;
656                         }
657                 }
658 #endif
659                 list_for_each_entry(sp, &net->sctp.auto_asconf_splist, auto_asconf_list) {
660                         struct sock *sk;
661 
662                         sk = sctp_opt2sk(sp);
663                         /* ignore bound-specific endpoints */
664                         if (!sctp_is_ep_boundall(sk))
665                                 continue;
666                         bh_lock_sock(sk);
667                         if (sctp_asconf_mgmt(sp, addrw) < 0)
668                                 pr_debug("%s: sctp_asconf_mgmt failed\n", __func__);
669                         bh_unlock_sock(sk);
670                 }
671 #if IS_ENABLED(CONFIG_IPV6)
672 free_next:
673 #endif
674                 list_del(&addrw->list);
675                 kfree(addrw);
676         }
677         spin_unlock_bh(&net->sctp.addr_wq_lock);
678 }
679 
680 static void sctp_free_addr_wq(struct net *net)
681 {
682         struct sctp_sockaddr_entry *addrw;
683         struct sctp_sockaddr_entry *temp;
684 
685         spin_lock_bh(&net->sctp.addr_wq_lock);
686         del_timer(&net->sctp.addr_wq_timer);
687         list_for_each_entry_safe(addrw, temp, &net->sctp.addr_waitq, list) {
688                 list_del(&addrw->list);
689                 kfree(addrw);
690         }
691         spin_unlock_bh(&net->sctp.addr_wq_lock);
692 }
693 
694 /* lookup the entry for the same address in the addr_waitq
695  * sctp_addr_wq MUST be locked
696  */
697 static struct sctp_sockaddr_entry *sctp_addr_wq_lookup(struct net *net,
698                                         struct sctp_sockaddr_entry *addr)
699 {
700         struct sctp_sockaddr_entry *addrw;
701 
702         list_for_each_entry(addrw, &net->sctp.addr_waitq, list) {
703                 if (addrw->a.sa.sa_family != addr->a.sa.sa_family)
704                         continue;
705                 if (addrw->a.sa.sa_family == AF_INET) {
706                         if (addrw->a.v4.sin_addr.s_addr ==
707                             addr->a.v4.sin_addr.s_addr)
708                                 return addrw;
709                 } else if (addrw->a.sa.sa_family == AF_INET6) {
710                         if (ipv6_addr_equal(&addrw->a.v6.sin6_addr,
711                             &addr->a.v6.sin6_addr))
712                                 return addrw;
713                 }
714         }
715         return NULL;
716 }
717 
718 void sctp_addr_wq_mgmt(struct net *net, struct sctp_sockaddr_entry *addr, int cmd)
719 {
720         struct sctp_sockaddr_entry *addrw;
721         unsigned long timeo_val;
722 
723         /* first, we check if an opposite message already exist in the queue.
724          * If we found such message, it is removed.
725          * This operation is a bit stupid, but the DHCP client attaches the
726          * new address after a couple of addition and deletion of that address
727          */
728 
729         spin_lock_bh(&net->sctp.addr_wq_lock);
730         /* Offsets existing events in addr_wq */
731         addrw = sctp_addr_wq_lookup(net, addr);
732         if (addrw) {
733                 if (addrw->state != cmd) {
734                         pr_debug("%s: offsets existing entry for %d, addr:%pISc "
735                                  "in wq:%p\n", __func__, addrw->state, &addrw->a.sa,
736                                  &net->sctp.addr_waitq);
737 
738                         list_del(&addrw->list);
739                         kfree(addrw);
740                 }
741                 spin_unlock_bh(&net->sctp.addr_wq_lock);
742                 return;
743         }
744 
745         /* OK, we have to add the new address to the wait queue */
746         addrw = kmemdup(addr, sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
747         if (addrw == NULL) {
748                 spin_unlock_bh(&net->sctp.addr_wq_lock);
749                 return;
750         }
751         addrw->state = cmd;
752         list_add_tail(&addrw->list, &net->sctp.addr_waitq);
753 
754         pr_debug("%s: add new entry for cmd:%d, addr:%pISc in wq:%p\n",
755                  __func__, addrw->state, &addrw->a.sa, &net->sctp.addr_waitq);
756 
757         if (!timer_pending(&net->sctp.addr_wq_timer)) {
758                 timeo_val = jiffies;
759                 timeo_val += msecs_to_jiffies(SCTP_ADDRESS_TICK_DELAY);
760                 mod_timer(&net->sctp.addr_wq_timer, timeo_val);
761         }
762         spin_unlock_bh(&net->sctp.addr_wq_lock);
763 }
764 
765 /* Event handler for inet address addition/deletion events.
766  * The sctp_local_addr_list needs to be protocted by a spin lock since
767  * multiple notifiers (say IPv4 and IPv6) may be running at the same
768  * time and thus corrupt the list.
769  * The reader side is protected with RCU.
770  */
771 static int sctp_inetaddr_event(struct notifier_block *this, unsigned long ev,
772                                void *ptr)
773 {
774         struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
775         struct sctp_sockaddr_entry *addr = NULL;
776         struct sctp_sockaddr_entry *temp;
777         struct net *net = dev_net(ifa->ifa_dev->dev);
778         int found = 0;
779 
780         switch (ev) {
781         case NETDEV_UP:
782                 addr = kzalloc(sizeof(*addr), GFP_ATOMIC);
783                 if (addr) {
784                         addr->a.v4.sin_family = AF_INET;
785                         addr->a.v4.sin_addr.s_addr = ifa->ifa_local;
786                         addr->valid = 1;
787                         spin_lock_bh(&net->sctp.local_addr_lock);
788                         list_add_tail_rcu(&addr->list, &net->sctp.local_addr_list);
789                         sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_NEW);
790                         spin_unlock_bh(&net->sctp.local_addr_lock);
791                 }
792                 break;
793         case NETDEV_DOWN:
794                 spin_lock_bh(&net->sctp.local_addr_lock);
795                 list_for_each_entry_safe(addr, temp,
796                                         &net->sctp.local_addr_list, list) {
797                         if (addr->a.sa.sa_family == AF_INET &&
798                                         addr->a.v4.sin_addr.s_addr ==
799                                         ifa->ifa_local) {
800                                 sctp_addr_wq_mgmt(net, addr, SCTP_ADDR_DEL);
801                                 found = 1;
802                                 addr->valid = 0;
803                                 list_del_rcu(&addr->list);
804                                 break;
805                         }
806                 }
807                 spin_unlock_bh(&net->sctp.local_addr_lock);
808                 if (found)
809                         kfree_rcu(addr, rcu);
810                 break;
811         }
812 
813         return NOTIFY_DONE;
814 }
815 
816 /*
817  * Initialize the control inode/socket with a control endpoint data
818  * structure.  This endpoint is reserved exclusively for the OOTB processing.
819  */
820 static int sctp_ctl_sock_init(struct net *net)
821 {
822         int err;
823         sa_family_t family = PF_INET;
824 
825         if (sctp_get_pf_specific(PF_INET6))
826                 family = PF_INET6;
827 
828         err = inet_ctl_sock_create(&net->sctp.ctl_sock, family,
829                                    SOCK_SEQPACKET, IPPROTO_SCTP, net);
830 
831         /* If IPv6 socket could not be created, try the IPv4 socket */
832         if (err < 0 && family == PF_INET6)
833                 err = inet_ctl_sock_create(&net->sctp.ctl_sock, AF_INET,
834                                            SOCK_SEQPACKET, IPPROTO_SCTP,
835                                            net);
836 
837         if (err < 0) {
838                 pr_err("Failed to create the SCTP control socket\n");
839                 return err;
840         }
841         return 0;
842 }
843 
844 static int sctp_udp_rcv(struct sock *sk, struct sk_buff *skb)
845 {
846         SCTP_INPUT_CB(skb)->encap_port = udp_hdr(skb)->source;
847 
848         skb_set_transport_header(skb, sizeof(struct udphdr));
849         sctp_rcv(skb);
850         return 0;
851 }
852 
853 static int sctp_udp_err_lookup(struct sock *sk, struct sk_buff *skb)
854 {
855         struct sctp_association *asoc;
856         struct sctp_transport *t;
857         int family;
858 
859         skb->transport_header += sizeof(struct udphdr);
860         family = (ip_hdr(skb)->version == 4) ? AF_INET : AF_INET6;
861         sk = sctp_err_lookup(dev_net(skb->dev), family, skb, sctp_hdr(skb),
862                              &asoc, &t);
863         if (!sk)
864                 return -ENOENT;
865 
866         sctp_err_finish(sk, t);
867         return 0;
868 }
869 
870 int sctp_udp_sock_start(struct net *net)
871 {
872         struct udp_tunnel_sock_cfg tuncfg = {NULL};
873         struct udp_port_cfg udp_conf = {0};
874         struct socket *sock;
875         int err;
876 
877         udp_conf.family = AF_INET;
878         udp_conf.local_ip.s_addr = htonl(INADDR_ANY);
879         udp_conf.local_udp_port = htons(net->sctp.udp_port);
880         err = udp_sock_create(net, &udp_conf, &sock);
881         if (err) {
882                 pr_err("Failed to create the SCTP UDP tunneling v4 sock\n");
883                 return err;
884         }
885 
886         tuncfg.encap_type = 1;
887         tuncfg.encap_rcv = sctp_udp_rcv;
888         tuncfg.encap_err_lookup = sctp_udp_err_lookup;
889         setup_udp_tunnel_sock(net, sock, &tuncfg);
890         net->sctp.udp4_sock = sock->sk;
891 
892 #if IS_ENABLED(CONFIG_IPV6)
893         memset(&udp_conf, 0, sizeof(udp_conf));
894 
895         udp_conf.family = AF_INET6;
896         udp_conf.local_ip6 = in6addr_any;
897         udp_conf.local_udp_port = htons(net->sctp.udp_port);
898         udp_conf.use_udp6_rx_checksums = true;
899         udp_conf.ipv6_v6only = true;
900         err = udp_sock_create(net, &udp_conf, &sock);
901         if (err) {
902                 pr_err("Failed to create the SCTP UDP tunneling v6 sock\n");
903                 udp_tunnel_sock_release(net->sctp.udp4_sock->sk_socket);
904                 net->sctp.udp4_sock = NULL;
905                 return err;
906         }
907 
908         tuncfg.encap_type = 1;
909         tuncfg.encap_rcv = sctp_udp_rcv;
910         tuncfg.encap_err_lookup = sctp_udp_err_lookup;
911         setup_udp_tunnel_sock(net, sock, &tuncfg);
912         net->sctp.udp6_sock = sock->sk;
913 #endif
914 
915         return 0;
916 }
917 
918 void sctp_udp_sock_stop(struct net *net)
919 {
920         if (net->sctp.udp4_sock) {
921                 udp_tunnel_sock_release(net->sctp.udp4_sock->sk_socket);
922                 net->sctp.udp4_sock = NULL;
923         }
924         if (net->sctp.udp6_sock) {
925                 udp_tunnel_sock_release(net->sctp.udp6_sock->sk_socket);
926                 net->sctp.udp6_sock = NULL;
927         }
928 }
929 
930 /* Register address family specific functions. */
931 int sctp_register_af(struct sctp_af *af)
932 {
933         switch (af->sa_family) {
934         case AF_INET:
935                 if (sctp_af_v4_specific)
936                         return 0;
937                 sctp_af_v4_specific = af;
938                 break;
939         case AF_INET6:
940                 if (sctp_af_v6_specific)
941                         return 0;
942                 sctp_af_v6_specific = af;
943                 break;
944         default:
945                 return 0;
946         }
947 
948         INIT_LIST_HEAD(&af->list);
949         list_add_tail(&af->list, &sctp_address_families);
950         return 1;
951 }
952 
953 /* Get the table of functions for manipulating a particular address
954  * family.
955  */
956 struct sctp_af *sctp_get_af_specific(sa_family_t family)
957 {
958         switch (family) {
959         case AF_INET:
960                 return sctp_af_v4_specific;
961         case AF_INET6:
962                 return sctp_af_v6_specific;
963         default:
964                 return NULL;
965         }
966 }
967 
968 /* Common code to initialize a AF_INET msg_name. */
969 static void sctp_inet_msgname(char *msgname, int *addr_len)
970 {
971         struct sockaddr_in *sin;
972 
973         sin = (struct sockaddr_in *)msgname;
974         *addr_len = sizeof(struct sockaddr_in);
975         sin->sin_family = AF_INET;
976         memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
977 }
978 
979 /* Copy the primary address of the peer primary address as the msg_name. */
980 static void sctp_inet_event_msgname(struct sctp_ulpevent *event, char *msgname,
981                                     int *addr_len)
982 {
983         struct sockaddr_in *sin, *sinfrom;
984 
985         if (msgname) {
986                 struct sctp_association *asoc;
987 
988                 asoc = event->asoc;
989                 sctp_inet_msgname(msgname, addr_len);
990                 sin = (struct sockaddr_in *)msgname;
991                 sinfrom = &asoc->peer.primary_addr.v4;
992                 sin->sin_port = htons(asoc->peer.port);
993                 sin->sin_addr.s_addr = sinfrom->sin_addr.s_addr;
994         }
995 }
996 
997 /* Initialize and copy out a msgname from an inbound skb. */
998 static void sctp_inet_skb_msgname(struct sk_buff *skb, char *msgname, int *len)
999 {
1000         if (msgname) {
1001                 struct sctphdr *sh = sctp_hdr(skb);
1002                 struct sockaddr_in *sin = (struct sockaddr_in *)msgname;
1003 
1004                 sctp_inet_msgname(msgname, len);
1005                 sin->sin_port = sh->source;
1006                 sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
1007         }
1008 }
1009 
1010 /* Do we support this AF? */
1011 static int sctp_inet_af_supported(sa_family_t family, struct sctp_sock *sp)
1012 {
1013         /* PF_INET only supports AF_INET addresses. */
1014         return AF_INET == family;
1015 }
1016 
1017 /* Address matching with wildcards allowed. */
1018 static int sctp_inet_cmp_addr(const union sctp_addr *addr1,
1019                               const union sctp_addr *addr2,
1020                               struct sctp_sock *opt)
1021 {
1022         /* PF_INET only supports AF_INET addresses. */
1023         if (addr1->sa.sa_family != addr2->sa.sa_family)
1024                 return 0;
1025         if (htonl(INADDR_ANY) == addr1->v4.sin_addr.s_addr ||
1026             htonl(INADDR_ANY) == addr2->v4.sin_addr.s_addr)
1027                 return 1;
1028         if (addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr)
1029                 return 1;
1030 
1031         return 0;
1032 }
1033 
1034 /* Verify that provided sockaddr looks bindable.  Common verification has
1035  * already been taken care of.
1036  */
1037 static int sctp_inet_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
1038 {
1039         return sctp_v4_available(addr, opt);
1040 }
1041 
1042 /* Verify that sockaddr looks sendable.  Common verification has already
1043  * been taken care of.
1044  */
1045 static int sctp_inet_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
1046 {
1047         return 1;
1048 }
1049 
1050 /* Fill in Supported Address Type information for INIT and INIT-ACK
1051  * chunks.  Returns number of addresses supported.
1052  */
1053 static int sctp_inet_supported_addrs(const struct sctp_sock *opt,
1054                                      __be16 *types)
1055 {
1056         types[0] = SCTP_PARAM_IPV4_ADDRESS;
1057         return 1;
1058 }
1059 
1060 /* Wrapper routine that calls the ip transmit routine. */
1061 static inline int sctp_v4_xmit(struct sk_buff *skb, struct sctp_transport *t)
1062 {
1063         struct dst_entry *dst = dst_clone(t->dst);
1064         struct flowi4 *fl4 = &t->fl.u.ip4;
1065         struct sock *sk = skb->sk;
1066         struct inet_sock *inet = inet_sk(sk);
1067         __u8 dscp = inet->tos;
1068         __be16 df = 0;
1069 
1070         pr_debug("%s: skb:%p, len:%d, src:%pI4, dst:%pI4\n", __func__, skb,
1071                  skb->len, &fl4->saddr, &fl4->daddr);
1072 
1073         if (t->dscp & SCTP_DSCP_SET_MASK)
1074                 dscp = t->dscp & SCTP_DSCP_VAL_MASK;
1075 
1076         inet->pmtudisc = t->param_flags & SPP_PMTUD_ENABLE ? IP_PMTUDISC_DO
1077                                                            : IP_PMTUDISC_DONT;
1078         SCTP_INC_STATS(sock_net(sk), SCTP_MIB_OUTSCTPPACKS);
1079 
1080         if (!t->encap_port || !sctp_sk(sk)->udp_port) {
1081                 skb_dst_set(skb, dst);
1082                 return __ip_queue_xmit(sk, skb, &t->fl, dscp);
1083         }
1084 
1085         if (skb_is_gso(skb))
1086                 skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL_CSUM;
1087 
1088         if (ip_dont_fragment(sk, dst) && !skb->ignore_df)
1089                 df = htons(IP_DF);
1090 
1091         skb->encapsulation = 1;
1092         skb_reset_inner_mac_header(skb);
1093         skb_reset_inner_transport_header(skb);
1094         skb_set_inner_ipproto(skb, IPPROTO_SCTP);
1095         udp_tunnel_xmit_skb((struct rtable *)dst, sk, skb, fl4->saddr,
1096                             fl4->daddr, dscp, ip4_dst_hoplimit(dst), df,
1097                             sctp_sk(sk)->udp_port, t->encap_port, false, false);
1098         return 0;
1099 }
1100 
1101 static struct sctp_af sctp_af_inet;
1102 
1103 static struct sctp_pf sctp_pf_inet = {
1104         .event_msgname = sctp_inet_event_msgname,
1105         .skb_msgname   = sctp_inet_skb_msgname,
1106         .af_supported  = sctp_inet_af_supported,
1107         .cmp_addr      = sctp_inet_cmp_addr,
1108         .bind_verify   = sctp_inet_bind_verify,
1109         .send_verify   = sctp_inet_send_verify,
1110         .supported_addrs = sctp_inet_supported_addrs,
1111         .create_accept_sk = sctp_v4_create_accept_sk,
1112         .addr_to_user  = sctp_v4_addr_to_user,
1113         .to_sk_saddr   = sctp_v4_to_sk_saddr,
1114         .to_sk_daddr   = sctp_v4_to_sk_daddr,
1115         .copy_ip_options = sctp_v4_copy_ip_options,
1116         .af            = &sctp_af_inet
1117 };
1118 
1119 /* Notifier for inetaddr addition/deletion events.  */
1120 static struct notifier_block sctp_inetaddr_notifier = {
1121         .notifier_call = sctp_inetaddr_event,
1122 };
1123 
1124 /* Socket operations.  */
1125 static const struct proto_ops inet_seqpacket_ops = {
1126         .family            = PF_INET,
1127         .owner             = THIS_MODULE,
1128         .release           = inet_release,      /* Needs to be wrapped... */
1129         .bind              = inet_bind,
1130         .connect           = sctp_inet_connect,
1131         .socketpair        = sock_no_socketpair,
1132         .accept            = inet_accept,
1133         .getname           = inet_getname,      /* Semantics are different.  */
1134         .poll              = sctp_poll,
1135         .ioctl             = inet_ioctl,
1136         .gettstamp         = sock_gettstamp,
1137         .listen            = sctp_inet_listen,
1138         .shutdown          = inet_shutdown,     /* Looks harmless.  */
1139         .setsockopt        = sock_common_setsockopt, /* IP_SOL IP_OPTION is a problem */
1140         .getsockopt        = sock_common_getsockopt,
1141         .sendmsg           = inet_sendmsg,
1142         .recvmsg           = inet_recvmsg,
1143         .mmap              = sock_no_mmap,
1144         .sendpage          = sock_no_sendpage,
1145 };
1146 
1147 /* Registration with AF_INET family.  */
1148 static struct inet_protosw sctp_seqpacket_protosw = {
1149         .type       = SOCK_SEQPACKET,
1150         .protocol   = IPPROTO_SCTP,
1151         .prot       = &sctp_prot,
1152         .ops        = &inet_seqpacket_ops,
1153         .flags      = SCTP_PROTOSW_FLAG
1154 };
1155 static struct inet_protosw sctp_stream_protosw = {
1156         .type       = SOCK_STREAM,
1157         .protocol   = IPPROTO_SCTP,
1158         .prot       = &sctp_prot,
1159         .ops        = &inet_seqpacket_ops,
1160         .flags      = SCTP_PROTOSW_FLAG
1161 };
1162 
1163 static int sctp4_rcv(struct sk_buff *skb)
1164 {
1165         SCTP_INPUT_CB(skb)->encap_port = 0;
1166         return sctp_rcv(skb);
1167 }
1168 
1169 /* Register with IP layer.  */
1170 static const struct net_protocol sctp_protocol = {
1171         .handler     = sctp4_rcv,
1172         .err_handler = sctp_v4_err,
1173         .no_policy   = 1,
1174         .netns_ok    = 1,
1175         .icmp_strict_tag_validation = 1,
1176 };
1177 
1178 /* IPv4 address related functions.  */
1179 static struct sctp_af sctp_af_inet = {
1180         .sa_family         = AF_INET,
1181         .sctp_xmit         = sctp_v4_xmit,
1182         .setsockopt        = ip_setsockopt,
1183         .getsockopt        = ip_getsockopt,
1184         .get_dst           = sctp_v4_get_dst,
1185         .get_saddr         = sctp_v4_get_saddr,
1186         .copy_addrlist     = sctp_v4_copy_addrlist,
1187         .from_skb          = sctp_v4_from_skb,
1188         .from_sk           = sctp_v4_from_sk,
1189         .from_addr_param   = sctp_v4_from_addr_param,
1190         .to_addr_param     = sctp_v4_to_addr_param,
1191         .cmp_addr          = sctp_v4_cmp_addr,
1192         .addr_valid        = sctp_v4_addr_valid,
1193         .inaddr_any        = sctp_v4_inaddr_any,
1194         .is_any            = sctp_v4_is_any,
1195         .available         = sctp_v4_available,
1196         .scope             = sctp_v4_scope,
1197         .skb_iif           = sctp_v4_skb_iif,
1198         .is_ce             = sctp_v4_is_ce,
1199         .seq_dump_addr     = sctp_v4_seq_dump_addr,
1200         .ecn_capable       = sctp_v4_ecn_capable,
1201         .net_header_len    = sizeof(struct iphdr),
1202         .sockaddr_len      = sizeof(struct sockaddr_in),
1203         .ip_options_len    = sctp_v4_ip_options_len,
1204 };
1205 
1206 struct sctp_pf *sctp_get_pf_specific(sa_family_t family)
1207 {
1208         switch (family) {
1209         case PF_INET:
1210                 return sctp_pf_inet_specific;
1211         case PF_INET6:
1212                 return sctp_pf_inet6_specific;
1213         default:
1214                 return NULL;
1215         }
1216 }
1217 
1218 /* Register the PF specific function table.  */
1219 int sctp_register_pf(struct sctp_pf *pf, sa_family_t family)
1220 {
1221         switch (family) {
1222         case PF_INET:
1223                 if (sctp_pf_inet_specific)
1224                         return 0;
1225                 sctp_pf_inet_specific = pf;
1226                 break;
1227         case PF_INET6:
1228                 if (sctp_pf_inet6_specific)
1229                         return 0;
1230                 sctp_pf_inet6_specific = pf;
1231                 break;
1232         default:
1233                 return 0;
1234         }
1235         return 1;
1236 }
1237 
1238 static inline int init_sctp_mibs(struct net *net)
1239 {
1240         net->sctp.sctp_statistics = alloc_percpu(struct sctp_mib);
1241         if (!net->sctp.sctp_statistics)
1242                 return -ENOMEM;
1243         return 0;
1244 }
1245 
1246 static inline void cleanup_sctp_mibs(struct net *net)
1247 {
1248         free_percpu(net->sctp.sctp_statistics);
1249 }
1250 
1251 static void sctp_v4_pf_init(void)
1252 {
1253         /* Initialize the SCTP specific PF functions. */
1254         sctp_register_pf(&sctp_pf_inet, PF_INET);
1255         sctp_register_af(&sctp_af_inet);
1256 }
1257 
1258 static void sctp_v4_pf_exit(void)
1259 {
1260         list_del(&sctp_af_inet.list);
1261 }
1262 
1263 static int sctp_v4_protosw_init(void)
1264 {
1265         int rc;
1266 
1267         rc = proto_register(&sctp_prot, 1);
1268         if (rc)
1269                 return rc;
1270 
1271         /* Register SCTP(UDP and TCP style) with socket layer.  */
1272         inet_register_protosw(&sctp_seqpacket_protosw);
1273         inet_register_protosw(&sctp_stream_protosw);
1274 
1275         return 0;
1276 }
1277 
1278 static void sctp_v4_protosw_exit(void)
1279 {
1280         inet_unregister_protosw(&sctp_stream_protosw);
1281         inet_unregister_protosw(&sctp_seqpacket_protosw);
1282         proto_unregister(&sctp_prot);
1283 }
1284 
1285 static int sctp_v4_add_protocol(void)
1286 {
1287         /* Register notifier for inet address additions/deletions. */
1288         register_inetaddr_notifier(&sctp_inetaddr_notifier);
1289 
1290         /* Register SCTP with inet layer.  */
1291         if (inet_add_protocol(&sctp_protocol, IPPROTO_SCTP) < 0)
1292                 return -EAGAIN;
1293 
1294         return 0;
1295 }
1296 
1297 static void sctp_v4_del_protocol(void)
1298 {
1299         inet_del_protocol(&sctp_protocol, IPPROTO_SCTP);
1300         unregister_inetaddr_notifier(&sctp_inetaddr_notifier);
1301 }
1302 
1303 static int __net_init sctp_defaults_init(struct net *net)
1304 {
1305         int status;
1306 
1307         /*
1308          * 14. Suggested SCTP Protocol Parameter Values
1309          */
1310         /* The following protocol parameters are RECOMMENDED:  */
1311         /* RTO.Initial              - 3  seconds */
1312         net->sctp.rto_initial                   = SCTP_RTO_INITIAL;
1313         /* RTO.Min                  - 1  second */
1314         net->sctp.rto_min                       = SCTP_RTO_MIN;
1315         /* RTO.Max                 -  60 seconds */
1316         net->sctp.rto_max                       = SCTP_RTO_MAX;
1317         /* RTO.Alpha                - 1/8 */
1318         net->sctp.rto_alpha                     = SCTP_RTO_ALPHA;
1319         /* RTO.Beta                 - 1/4 */
1320         net->sctp.rto_beta                      = SCTP_RTO_BETA;
1321 
1322         /* Valid.Cookie.Life        - 60  seconds */
1323         net->sctp.valid_cookie_life             = SCTP_DEFAULT_COOKIE_LIFE;
1324 
1325         /* Whether Cookie Preservative is enabled(1) or not(0) */
1326         net->sctp.cookie_preserve_enable        = 1;
1327 
1328         /* Default sctp sockets to use md5 as their hmac alg */
1329 #if defined (CONFIG_SCTP_DEFAULT_COOKIE_HMAC_MD5)
1330         net->sctp.sctp_hmac_alg                 = "md5";
1331 #elif defined (CONFIG_SCTP_DEFAULT_COOKIE_HMAC_SHA1)
1332         net->sctp.sctp_hmac_alg                 = "sha1";
1333 #else
1334         net->sctp.sctp_hmac_alg                 = NULL;
1335 #endif
1336 
1337         /* Max.Burst                - 4 */
1338         net->sctp.max_burst                     = SCTP_DEFAULT_MAX_BURST;
1339 
1340         /* Disable of Primary Path Switchover by default */
1341         net->sctp.ps_retrans = SCTP_PS_RETRANS_MAX;
1342 
1343         /* Enable pf state by default */
1344         net->sctp.pf_enable = 1;
1345 
1346         /* Ignore pf exposure feature by default */
1347         net->sctp.pf_expose = SCTP_PF_EXPOSE_UNSET;
1348 
1349         /* Association.Max.Retrans  - 10 attempts
1350          * Path.Max.Retrans         - 5  attempts (per destination address)
1351          * Max.Init.Retransmits     - 8  attempts
1352          */
1353         net->sctp.max_retrans_association       = 10;
1354         net->sctp.max_retrans_path              = 5;
1355         net->sctp.max_retrans_init              = 8;
1356 
1357         /* Sendbuffer growth        - do per-socket accounting */
1358         net->sctp.sndbuf_policy                 = 0;
1359 
1360         /* Rcvbuffer growth         - do per-socket accounting */
1361         net->sctp.rcvbuf_policy                 = 0;
1362 
1363         /* HB.interval              - 30 seconds */
1364         net->sctp.hb_interval                   = SCTP_DEFAULT_TIMEOUT_HEARTBEAT;
1365 
1366         /* delayed SACK timeout */
1367         net->sctp.sack_timeout                  = SCTP_DEFAULT_TIMEOUT_SACK;
1368 
1369         /* Disable ADDIP by default. */
1370         net->sctp.addip_enable = 0;
1371         net->sctp.addip_noauth = 0;
1372         net->sctp.default_auto_asconf = 0;
1373 
1374         /* Enable PR-SCTP by default. */
1375         net->sctp.prsctp_enable = 1;
1376 
1377         /* Disable RECONF by default. */
1378         net->sctp.reconf_enable = 0;
1379 
1380         /* Disable AUTH by default. */
1381         net->sctp.auth_enable = 0;
1382 
1383         /* Enable ECN by default. */
1384         net->sctp.ecn_enable = 1;
1385 
1386         /* Set UDP tunneling listening port to 0 by default */
1387         net->sctp.udp_port = 0;
1388 
1389         /* Set remote encap port to 0 by default */
1390         net->sctp.encap_port = 0;
1391 
1392         /* Set SCOPE policy to enabled */
1393         net->sctp.scope_policy = SCTP_SCOPE_POLICY_ENABLE;
1394 
1395         /* Set the default rwnd update threshold */
1396         net->sctp.rwnd_upd_shift = SCTP_DEFAULT_RWND_SHIFT;
1397 
1398         /* Initialize maximum autoclose timeout. */
1399         net->sctp.max_autoclose         = INT_MAX / HZ;
1400 
1401         status = sctp_sysctl_net_register(net);
1402         if (status)
1403                 goto err_sysctl_register;
1404 
1405         /* Allocate and initialise sctp mibs.  */
1406         status = init_sctp_mibs(net);
1407         if (status)
1408                 goto err_init_mibs;
1409 
1410 #ifdef CONFIG_PROC_FS
1411         /* Initialize proc fs directory.  */
1412         status = sctp_proc_init(net);
1413         if (status)
1414                 goto err_init_proc;
1415 #endif
1416 
1417         sctp_dbg_objcnt_init(net);
1418 
1419         /* Initialize the local address list. */
1420         INIT_LIST_HEAD(&net->sctp.local_addr_list);
1421         spin_lock_init(&net->sctp.local_addr_lock);
1422         sctp_get_local_addr_list(net);
1423 
1424         /* Initialize the address event list */
1425         INIT_LIST_HEAD(&net->sctp.addr_waitq);
1426         INIT_LIST_HEAD(&net->sctp.auto_asconf_splist);
1427         spin_lock_init(&net->sctp.addr_wq_lock);
1428         net->sctp.addr_wq_timer.expires = 0;
1429         timer_setup(&net->sctp.addr_wq_timer, sctp_addr_wq_timeout_handler, 0);
1430 
1431         return 0;
1432 
1433 #ifdef CONFIG_PROC_FS
1434 err_init_proc:
1435         cleanup_sctp_mibs(net);
1436 #endif
1437 err_init_mibs:
1438         sctp_sysctl_net_unregister(net);
1439 err_sysctl_register:
1440         return status;
1441 }
1442 
1443 static void __net_exit sctp_defaults_exit(struct net *net)
1444 {
1445         /* Free the local address list */
1446         sctp_free_addr_wq(net);
1447         sctp_free_local_addr_list(net);
1448 
1449 #ifdef CONFIG_PROC_FS
1450         remove_proc_subtree("sctp", net->proc_net);
1451         net->sctp.proc_net_sctp = NULL;
1452 #endif
1453         cleanup_sctp_mibs(net);
1454         sctp_sysctl_net_unregister(net);
1455 }
1456 
1457 static struct pernet_operations sctp_defaults_ops = {
1458         .init = sctp_defaults_init,
1459         .exit = sctp_defaults_exit,
1460 };
1461 
1462 static int __net_init sctp_ctrlsock_init(struct net *net)
1463 {
1464         int status;
1465 
1466         /* Initialize the control inode/socket for handling OOTB packets.  */
1467         status = sctp_ctl_sock_init(net);
1468         if (status)
1469                 pr_err("Failed to initialize the SCTP control sock\n");
1470 
1471         return status;
1472 }
1473 
1474 static void __net_exit sctp_ctrlsock_exit(struct net *net)
1475 {
1476         /* Free the control endpoint.  */
1477         inet_ctl_sock_destroy(net->sctp.ctl_sock);
1478 }
1479 
1480 static struct pernet_operations sctp_ctrlsock_ops = {
1481         .init = sctp_ctrlsock_init,
1482         .exit = sctp_ctrlsock_exit,
1483 };
1484 
1485 /* Initialize the universe into something sensible.  */
1486 static __init int sctp_init(void)
1487 {
1488         unsigned long nr_pages = totalram_pages();
1489         unsigned long limit;
1490         unsigned long goal;
1491         int max_entry_order;
1492         int num_entries;
1493         int max_share;
1494         int status;
1495         int order;
1496         int i;
1497 
1498         sock_skb_cb_check_size(sizeof(struct sctp_ulpevent));
1499 
1500         /* Allocate bind_bucket and chunk caches. */
1501         status = -ENOBUFS;
1502         sctp_bucket_cachep = kmem_cache_create("sctp_bind_bucket",
1503                                                sizeof(struct sctp_bind_bucket),
1504                                                0, SLAB_HWCACHE_ALIGN,
1505                                                NULL);
1506         if (!sctp_bucket_cachep)
1507                 goto out;
1508 
1509         sctp_chunk_cachep = kmem_cache_create("sctp_chunk",
1510                                                sizeof(struct sctp_chunk),
1511                                                0, SLAB_HWCACHE_ALIGN,
1512                                                NULL);
1513         if (!sctp_chunk_cachep)
1514                 goto err_chunk_cachep;
1515 
1516         status = percpu_counter_init(&sctp_sockets_allocated, 0, GFP_KERNEL);
1517         if (status)
1518                 goto err_percpu_counter_init;
1519 
1520         /* Implementation specific variables. */
1521 
1522         /* Initialize default stream count setup information. */
1523         sctp_max_instreams              = SCTP_DEFAULT_INSTREAMS;
1524         sctp_max_outstreams             = SCTP_DEFAULT_OUTSTREAMS;
1525 
1526         /* Initialize handle used for association ids. */
1527         idr_init(&sctp_assocs_id);
1528 
1529         limit = nr_free_buffer_pages() / 8;
1530         limit = max(limit, 128UL);
1531         sysctl_sctp_mem[0] = limit / 4 * 3;
1532         sysctl_sctp_mem[1] = limit;
1533         sysctl_sctp_mem[2] = sysctl_sctp_mem[0] * 2;
1534 
1535         /* Set per-socket limits to no more than 1/128 the pressure threshold*/
1536         limit = (sysctl_sctp_mem[1]) << (PAGE_SHIFT - 7);
1537         max_share = min(4UL*1024*1024, limit);
1538 
1539         sysctl_sctp_rmem[0] = SK_MEM_QUANTUM; /* give each asoc 1 page min */
1540         sysctl_sctp_rmem[1] = 1500 * SKB_TRUESIZE(1);
1541         sysctl_sctp_rmem[2] = max(sysctl_sctp_rmem[1], max_share);
1542 
1543         sysctl_sctp_wmem[0] = SK_MEM_QUANTUM;
1544         sysctl_sctp_wmem[1] = 16*1024;
1545         sysctl_sctp_wmem[2] = max(64*1024, max_share);
1546 
1547         /* Size and allocate the association hash table.
1548          * The methodology is similar to that of the tcp hash tables.
1549          * Though not identical.  Start by getting a goal size
1550          */
1551         if (nr_pages >= (128 * 1024))
1552                 goal = nr_pages >> (22 - PAGE_SHIFT);
1553         else
1554                 goal = nr_pages >> (24 - PAGE_SHIFT);
1555 
1556         /* Then compute the page order for said goal */
1557         order = get_order(goal);
1558 
1559         /* Now compute the required page order for the maximum sized table we
1560          * want to create
1561          */
1562         max_entry_order = get_order(MAX_SCTP_PORT_HASH_ENTRIES *
1563                                     sizeof(struct sctp_bind_hashbucket));
1564 
1565         /* Limit the page order by that maximum hash table size */
1566         order = min(order, max_entry_order);
1567 
1568         /* Allocate and initialize the endpoint hash table.  */
1569         sctp_ep_hashsize = 64;
1570         sctp_ep_hashtable =
1571                 kmalloc_array(64, sizeof(struct sctp_hashbucket), GFP_KERNEL);
1572         if (!sctp_ep_hashtable) {
1573                 pr_err("Failed endpoint_hash alloc\n");
1574                 status = -ENOMEM;
1575                 goto err_ehash_alloc;
1576         }
1577         for (i = 0; i < sctp_ep_hashsize; i++) {
1578                 rwlock_init(&sctp_ep_hashtable[i].lock);
1579                 INIT_HLIST_HEAD(&sctp_ep_hashtable[i].chain);
1580         }
1581 
1582         /* Allocate and initialize the SCTP port hash table.
1583          * Note that order is initalized to start at the max sized
1584          * table we want to support.  If we can't get that many pages
1585          * reduce the order and try again
1586          */
1587         do {
1588                 sctp_port_hashtable = (struct sctp_bind_hashbucket *)
1589                         __get_free_pages(GFP_KERNEL | __GFP_NOWARN, order);
1590         } while (!sctp_port_hashtable && --order > 0);
1591 
1592         if (!sctp_port_hashtable) {
1593                 pr_err("Failed bind hash alloc\n");
1594                 status = -ENOMEM;
1595                 goto err_bhash_alloc;
1596         }
1597 
1598         /* Now compute the number of entries that will fit in the
1599          * port hash space we allocated
1600          */
1601         num_entries = (1UL << order) * PAGE_SIZE /
1602                       sizeof(struct sctp_bind_hashbucket);
1603 
1604         /* And finish by rounding it down to the nearest power of two.
1605          * This wastes some memory of course, but it's needed because
1606          * the hash function operates based on the assumption that
1607          * the number of entries is a power of two.
1608          */
1609         sctp_port_hashsize = rounddown_pow_of_two(num_entries);
1610 
1611         for (i = 0; i < sctp_port_hashsize; i++) {
1612                 spin_lock_init(&sctp_port_hashtable[i].lock);
1613                 INIT_HLIST_HEAD(&sctp_port_hashtable[i].chain);
1614         }
1615 
1616         status = sctp_transport_hashtable_init();
1617         if (status)
1618                 goto err_thash_alloc;
1619 
1620         pr_info("Hash tables configured (bind %d/%d)\n", sctp_port_hashsize,
1621                 num_entries);
1622 
1623         sctp_sysctl_register();
1624 
1625         INIT_LIST_HEAD(&sctp_address_families);
1626         sctp_v4_pf_init();
1627         sctp_v6_pf_init();
1628         sctp_sched_ops_init();
1629 
1630         status = register_pernet_subsys(&sctp_defaults_ops);
1631         if (status)
1632                 goto err_register_defaults;
1633 
1634         status = sctp_v4_protosw_init();
1635         if (status)
1636                 goto err_protosw_init;
1637 
1638         status = sctp_v6_protosw_init();
1639         if (status)
1640                 goto err_v6_protosw_init;
1641 
1642         status = register_pernet_subsys(&sctp_ctrlsock_ops);
1643         if (status)
1644                 goto err_register_ctrlsock;
1645 
1646         status = sctp_v4_add_protocol();
1647         if (status)
1648                 goto err_add_protocol;
1649 
1650         /* Register SCTP with inet6 layer.  */
1651         status = sctp_v6_add_protocol();
1652         if (status)
1653                 goto err_v6_add_protocol;
1654 
1655         if (sctp_offload_init() < 0)
1656                 pr_crit("%s: Cannot add SCTP protocol offload\n", __func__);
1657 
1658 out:
1659         return status;
1660 err_v6_add_protocol:
1661         sctp_v4_del_protocol();
1662 err_add_protocol:
1663         unregister_pernet_subsys(&sctp_ctrlsock_ops);
1664 err_register_ctrlsock:
1665         sctp_v6_protosw_exit();
1666 err_v6_protosw_init:
1667         sctp_v4_protosw_exit();
1668 err_protosw_init:
1669         unregister_pernet_subsys(&sctp_defaults_ops);
1670 err_register_defaults:
1671         sctp_v4_pf_exit();
1672         sctp_v6_pf_exit();
1673         sctp_sysctl_unregister();
1674         free_pages((unsigned long)sctp_port_hashtable,
1675                    get_order(sctp_port_hashsize *
1676                              sizeof(struct sctp_bind_hashbucket)));
1677 err_bhash_alloc:
1678         sctp_transport_hashtable_destroy();
1679 err_thash_alloc:
1680         kfree(sctp_ep_hashtable);
1681 err_ehash_alloc:
1682         percpu_counter_destroy(&sctp_sockets_allocated);
1683 err_percpu_counter_init:
1684         kmem_cache_destroy(sctp_chunk_cachep);
1685 err_chunk_cachep:
1686         kmem_cache_destroy(sctp_bucket_cachep);
1687         goto out;
1688 }
1689 
1690 /* Exit handler for the SCTP protocol.  */
1691 static __exit void sctp_exit(void)
1692 {
1693         /* BUG.  This should probably do something useful like clean
1694          * up all the remaining associations and all that memory.
1695          */
1696 
1697         /* Unregister with inet6/inet layers. */
1698         sctp_v6_del_protocol();
1699         sctp_v4_del_protocol();
1700 
1701         unregister_pernet_subsys(&sctp_ctrlsock_ops);
1702 
1703         /* Free protosw registrations */
1704         sctp_v6_protosw_exit();
1705         sctp_v4_protosw_exit();
1706 
1707         unregister_pernet_subsys(&sctp_defaults_ops);
1708 
1709         /* Unregister with socket layer. */
1710         sctp_v6_pf_exit();
1711         sctp_v4_pf_exit();
1712 
1713         sctp_sysctl_unregister();
1714 
1715         free_pages((unsigned long)sctp_port_hashtable,
1716                    get_order(sctp_port_hashsize *
1717                              sizeof(struct sctp_bind_hashbucket)));
1718         kfree(sctp_ep_hashtable);
1719         sctp_transport_hashtable_destroy();
1720 
1721         percpu_counter_destroy(&sctp_sockets_allocated);
1722 
1723         rcu_barrier(); /* Wait for completion of call_rcu()'s */
1724 
1725         kmem_cache_destroy(sctp_chunk_cachep);
1726         kmem_cache_destroy(sctp_bucket_cachep);
1727 }
1728 
1729 module_init(sctp_init);
1730 module_exit(sctp_exit);
1731 
1732 /*
1733  * __stringify doesn't likes enums, so use IPPROTO_SCTP value (132) directly.
1734  */
1735 MODULE_ALIAS("net-pf-" __stringify(PF_INET) "-proto-132");
1736 MODULE_ALIAS("net-pf-" __stringify(PF_INET6) "-proto-132");
1737 MODULE_AUTHOR("Linux Kernel SCTP developers <linux-sctp@vger.kernel.org>");
1738 MODULE_DESCRIPTION("Support for the SCTP protocol (RFC2960)");
1739 module_param_named(no_checksums, sctp_checksum_disable, bool, 0644);
1740 MODULE_PARM_DESC(no_checksums, "Disable checksums computing and verification");
1741 MODULE_LICENSE("GPL");
1742 

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