1 // SPDX-License-Identifier: GPL-2.0
2 /* Multipath TCP
3 *
4 * Copyright (c) 2022, Intel Corporation.
5 */
6
7 #include "protocol.h"
8 #include "mib.h"
9
mptcp_free_local_addr_list(struct mptcp_sock * msk)10 void mptcp_free_local_addr_list(struct mptcp_sock *msk)
11 {
12 struct mptcp_pm_addr_entry *entry, *tmp;
13 struct sock *sk = (struct sock *)msk;
14 LIST_HEAD(free_list);
15
16 if (!mptcp_pm_is_userspace(msk))
17 return;
18
19 spin_lock_bh(&msk->pm.lock);
20 list_splice_init(&msk->pm.userspace_pm_local_addr_list, &free_list);
21 spin_unlock_bh(&msk->pm.lock);
22
23 list_for_each_entry_safe(entry, tmp, &free_list, list) {
24 sock_kfree_s(sk, entry, sizeof(*entry));
25 }
26 }
27
mptcp_userspace_pm_append_new_local_addr(struct mptcp_sock * msk,struct mptcp_pm_addr_entry * entry,bool needs_id)28 static int mptcp_userspace_pm_append_new_local_addr(struct mptcp_sock *msk,
29 struct mptcp_pm_addr_entry *entry,
30 bool needs_id)
31 {
32 DECLARE_BITMAP(id_bitmap, MPTCP_PM_MAX_ADDR_ID + 1);
33 struct mptcp_pm_addr_entry *match = NULL;
34 struct sock *sk = (struct sock *)msk;
35 struct mptcp_pm_addr_entry *e;
36 bool addr_match = false;
37 bool id_match = false;
38 int ret = -EINVAL;
39
40 bitmap_zero(id_bitmap, MPTCP_PM_MAX_ADDR_ID + 1);
41
42 spin_lock_bh(&msk->pm.lock);
43 list_for_each_entry(e, &msk->pm.userspace_pm_local_addr_list, list) {
44 addr_match = mptcp_addresses_equal(&e->addr, &entry->addr, true);
45 if (addr_match && entry->addr.id == 0 && needs_id)
46 entry->addr.id = e->addr.id;
47 id_match = (e->addr.id == entry->addr.id);
48 if (addr_match && id_match) {
49 match = e;
50 break;
51 } else if (addr_match || id_match) {
52 break;
53 }
54 __set_bit(e->addr.id, id_bitmap);
55 }
56
57 if (!match && !addr_match && !id_match) {
58 /* Memory for the entry is allocated from the
59 * sock option buffer.
60 */
61 e = sock_kmalloc(sk, sizeof(*e), GFP_ATOMIC);
62 if (!e) {
63 ret = -ENOMEM;
64 goto append_err;
65 }
66
67 *e = *entry;
68 if (!e->addr.id && needs_id)
69 e->addr.id = find_next_zero_bit(id_bitmap,
70 MPTCP_PM_MAX_ADDR_ID + 1,
71 1);
72 list_add_tail_rcu(&e->list, &msk->pm.userspace_pm_local_addr_list);
73 msk->pm.local_addr_used++;
74 ret = e->addr.id;
75 } else if (match) {
76 ret = entry->addr.id;
77 }
78
79 append_err:
80 spin_unlock_bh(&msk->pm.lock);
81 return ret;
82 }
83
84 /* If the subflow is closed from the other peer (not via a
85 * subflow destroy command then), we want to keep the entry
86 * not to assign the same ID to another address and to be
87 * able to send RM_ADDR after the removal of the subflow.
88 */
mptcp_userspace_pm_delete_local_addr(struct mptcp_sock * msk,struct mptcp_pm_addr_entry * addr)89 static int mptcp_userspace_pm_delete_local_addr(struct mptcp_sock *msk,
90 struct mptcp_pm_addr_entry *addr)
91 {
92 struct mptcp_pm_addr_entry *entry, *tmp;
93 struct sock *sk = (struct sock *)msk;
94
95 list_for_each_entry_safe(entry, tmp, &msk->pm.userspace_pm_local_addr_list, list) {
96 if (mptcp_addresses_equal(&entry->addr, &addr->addr, false)) {
97 /* TODO: a refcount is needed because the entry can
98 * be used multiple times (e.g. fullmesh mode).
99 */
100 list_del_rcu(&entry->list);
101 sock_kfree_s(sk, entry, sizeof(*entry));
102 msk->pm.local_addr_used--;
103 return 0;
104 }
105 }
106
107 return -EINVAL;
108 }
109
110 static struct mptcp_pm_addr_entry *
mptcp_userspace_pm_lookup_addr_by_id(struct mptcp_sock * msk,unsigned int id)111 mptcp_userspace_pm_lookup_addr_by_id(struct mptcp_sock *msk, unsigned int id)
112 {
113 struct mptcp_pm_addr_entry *entry;
114
115 list_for_each_entry(entry, &msk->pm.userspace_pm_local_addr_list, list) {
116 if (entry->addr.id == id)
117 return entry;
118 }
119 return NULL;
120 }
121
mptcp_userspace_pm_get_flags_and_ifindex_by_id(struct mptcp_sock * msk,unsigned int id,u8 * flags,int * ifindex)122 int mptcp_userspace_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk,
123 unsigned int id,
124 u8 *flags, int *ifindex)
125 {
126 struct mptcp_pm_addr_entry *match;
127
128 spin_lock_bh(&msk->pm.lock);
129 match = mptcp_userspace_pm_lookup_addr_by_id(msk, id);
130 spin_unlock_bh(&msk->pm.lock);
131 if (match) {
132 *flags = match->flags;
133 *ifindex = match->ifindex;
134 }
135
136 return 0;
137 }
138
mptcp_userspace_pm_get_local_id(struct mptcp_sock * msk,struct mptcp_addr_info * skc)139 int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk,
140 struct mptcp_addr_info *skc)
141 {
142 struct mptcp_pm_addr_entry *entry = NULL, *e, new_entry;
143 __be16 msk_sport = ((struct inet_sock *)
144 inet_sk((struct sock *)msk))->inet_sport;
145
146 spin_lock_bh(&msk->pm.lock);
147 list_for_each_entry(e, &msk->pm.userspace_pm_local_addr_list, list) {
148 if (mptcp_addresses_equal(&e->addr, skc, false)) {
149 entry = e;
150 break;
151 }
152 }
153 spin_unlock_bh(&msk->pm.lock);
154 if (entry)
155 return entry->addr.id;
156
157 memset(&new_entry, 0, sizeof(struct mptcp_pm_addr_entry));
158 new_entry.addr = *skc;
159 new_entry.addr.id = 0;
160 new_entry.flags = MPTCP_PM_ADDR_FLAG_IMPLICIT;
161
162 if (new_entry.addr.port == msk_sport)
163 new_entry.addr.port = 0;
164
165 return mptcp_userspace_pm_append_new_local_addr(msk, &new_entry, true);
166 }
167
mptcp_userspace_pm_is_backup(struct mptcp_sock * msk,struct mptcp_addr_info * skc)168 bool mptcp_userspace_pm_is_backup(struct mptcp_sock *msk,
169 struct mptcp_addr_info *skc)
170 {
171 struct mptcp_pm_addr_entry *entry;
172 bool backup = false;
173
174 spin_lock_bh(&msk->pm.lock);
175 list_for_each_entry(entry, &msk->pm.userspace_pm_local_addr_list, list) {
176 if (mptcp_addresses_equal(&entry->addr, skc, false)) {
177 backup = !!(entry->flags & MPTCP_PM_ADDR_FLAG_BACKUP);
178 break;
179 }
180 }
181 spin_unlock_bh(&msk->pm.lock);
182
183 return backup;
184 }
185
mptcp_nl_cmd_announce(struct sk_buff * skb,struct genl_info * info)186 int mptcp_nl_cmd_announce(struct sk_buff *skb, struct genl_info *info)
187 {
188 struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
189 struct nlattr *addr = info->attrs[MPTCP_PM_ATTR_ADDR];
190 struct mptcp_pm_addr_entry addr_val;
191 struct mptcp_sock *msk;
192 int err = -EINVAL;
193 struct sock *sk;
194 u32 token_val;
195
196 if (!addr || !token) {
197 GENL_SET_ERR_MSG(info, "missing required inputs");
198 return err;
199 }
200
201 token_val = nla_get_u32(token);
202
203 msk = mptcp_token_get_sock(sock_net(skb->sk), token_val);
204 if (!msk) {
205 NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
206 return err;
207 }
208
209 sk = (struct sock *)msk;
210
211 if (!mptcp_pm_is_userspace(msk)) {
212 GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
213 goto announce_err;
214 }
215
216 err = mptcp_pm_parse_entry(addr, info, true, &addr_val);
217 if (err < 0) {
218 GENL_SET_ERR_MSG(info, "error parsing local address");
219 goto announce_err;
220 }
221
222 if (addr_val.addr.id == 0 || !(addr_val.flags & MPTCP_PM_ADDR_FLAG_SIGNAL)) {
223 GENL_SET_ERR_MSG(info, "invalid addr id or flags");
224 err = -EINVAL;
225 goto announce_err;
226 }
227
228 err = mptcp_userspace_pm_append_new_local_addr(msk, &addr_val, false);
229 if (err < 0) {
230 GENL_SET_ERR_MSG(info, "did not match address and id");
231 goto announce_err;
232 }
233
234 lock_sock(sk);
235 spin_lock_bh(&msk->pm.lock);
236
237 if (mptcp_pm_alloc_anno_list(msk, &addr_val.addr)) {
238 msk->pm.add_addr_signaled++;
239 mptcp_pm_announce_addr(msk, &addr_val.addr, false);
240 mptcp_pm_nl_addr_send_ack(msk);
241 }
242
243 spin_unlock_bh(&msk->pm.lock);
244 release_sock(sk);
245
246 err = 0;
247 announce_err:
248 sock_put(sk);
249 return err;
250 }
251
mptcp_userspace_pm_remove_id_zero_address(struct mptcp_sock * msk,struct genl_info * info)252 static int mptcp_userspace_pm_remove_id_zero_address(struct mptcp_sock *msk,
253 struct genl_info *info)
254 {
255 struct mptcp_rm_list list = { .nr = 0 };
256 struct mptcp_subflow_context *subflow;
257 struct sock *sk = (struct sock *)msk;
258 bool has_id_0 = false;
259 int err = -EINVAL;
260
261 lock_sock(sk);
262 mptcp_for_each_subflow(msk, subflow) {
263 if (subflow->local_id == 0) {
264 has_id_0 = true;
265 break;
266 }
267 }
268 if (!has_id_0) {
269 GENL_SET_ERR_MSG(info, "address with id 0 not found");
270 goto remove_err;
271 }
272
273 list.ids[list.nr++] = 0;
274
275 spin_lock_bh(&msk->pm.lock);
276 mptcp_pm_remove_addr(msk, &list);
277 spin_unlock_bh(&msk->pm.lock);
278
279 err = 0;
280
281 remove_err:
282 release_sock(sk);
283 return err;
284 }
285
mptcp_nl_cmd_remove(struct sk_buff * skb,struct genl_info * info)286 int mptcp_nl_cmd_remove(struct sk_buff *skb, struct genl_info *info)
287 {
288 struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
289 struct nlattr *id = info->attrs[MPTCP_PM_ATTR_LOC_ID];
290 struct mptcp_pm_addr_entry *match;
291 struct mptcp_pm_addr_entry *entry;
292 struct mptcp_sock *msk;
293 LIST_HEAD(free_list);
294 int err = -EINVAL;
295 struct sock *sk;
296 u32 token_val;
297 u8 id_val;
298
299 if (!id || !token) {
300 GENL_SET_ERR_MSG(info, "missing required inputs");
301 return err;
302 }
303
304 id_val = nla_get_u8(id);
305 token_val = nla_get_u32(token);
306
307 msk = mptcp_token_get_sock(sock_net(skb->sk), token_val);
308 if (!msk) {
309 NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
310 return err;
311 }
312
313 sk = (struct sock *)msk;
314
315 if (!mptcp_pm_is_userspace(msk)) {
316 GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
317 goto remove_err;
318 }
319
320 if (id_val == 0) {
321 err = mptcp_userspace_pm_remove_id_zero_address(msk, info);
322 goto remove_err;
323 }
324
325 lock_sock(sk);
326
327 spin_lock_bh(&msk->pm.lock);
328 match = mptcp_userspace_pm_lookup_addr_by_id(msk, id_val);
329 if (!match) {
330 GENL_SET_ERR_MSG(info, "address with specified id not found");
331 spin_unlock_bh(&msk->pm.lock);
332 release_sock(sk);
333 goto remove_err;
334 }
335
336 list_move(&match->list, &free_list);
337 spin_unlock_bh(&msk->pm.lock);
338
339 mptcp_pm_remove_addrs(msk, &free_list);
340
341 release_sock(sk);
342
343 list_for_each_entry_safe(match, entry, &free_list, list) {
344 sock_kfree_s(sk, match, sizeof(*match));
345 }
346
347 err = 0;
348 remove_err:
349 sock_put(sk);
350 return err;
351 }
352
mptcp_nl_cmd_sf_create(struct sk_buff * skb,struct genl_info * info)353 int mptcp_nl_cmd_sf_create(struct sk_buff *skb, struct genl_info *info)
354 {
355 struct nlattr *raddr = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
356 struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
357 struct nlattr *laddr = info->attrs[MPTCP_PM_ATTR_ADDR];
358 struct mptcp_pm_addr_entry local = { 0 };
359 struct mptcp_addr_info addr_r;
360 struct mptcp_addr_info addr_l;
361 struct mptcp_sock *msk;
362 int err = -EINVAL;
363 struct sock *sk;
364 u32 token_val;
365
366 if (!laddr || !raddr || !token) {
367 GENL_SET_ERR_MSG(info, "missing required inputs");
368 return err;
369 }
370
371 token_val = nla_get_u32(token);
372
373 msk = mptcp_token_get_sock(genl_info_net(info), token_val);
374 if (!msk) {
375 NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
376 return err;
377 }
378
379 if (!mptcp_pm_is_userspace(msk)) {
380 GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
381 goto create_err;
382 }
383
384 err = mptcp_pm_parse_addr(laddr, info, &addr_l);
385 if (err < 0) {
386 NL_SET_ERR_MSG_ATTR(info->extack, laddr, "error parsing local addr");
387 goto create_err;
388 }
389
390 err = mptcp_pm_parse_addr(raddr, info, &addr_r);
391 if (err < 0) {
392 NL_SET_ERR_MSG_ATTR(info->extack, raddr, "error parsing remote addr");
393 goto create_err;
394 }
395
396 sk = (struct sock *)msk;
397
398 if (!mptcp_pm_addr_families_match(sk, &addr_l, &addr_r)) {
399 GENL_SET_ERR_MSG(info, "families mismatch");
400 err = -EINVAL;
401 goto create_err;
402 }
403
404 local.addr = addr_l;
405 err = mptcp_userspace_pm_append_new_local_addr(msk, &local, false);
406 if (err < 0) {
407 GENL_SET_ERR_MSG(info, "did not match address and id");
408 goto create_err;
409 }
410
411 lock_sock(sk);
412
413 err = __mptcp_subflow_connect(sk, &addr_l, &addr_r);
414
415 release_sock(sk);
416
417 spin_lock_bh(&msk->pm.lock);
418 if (err)
419 mptcp_userspace_pm_delete_local_addr(msk, &local);
420 else
421 msk->pm.subflows++;
422 spin_unlock_bh(&msk->pm.lock);
423
424 create_err:
425 sock_put((struct sock *)msk);
426 return err;
427 }
428
mptcp_nl_find_ssk(struct mptcp_sock * msk,const struct mptcp_addr_info * local,const struct mptcp_addr_info * remote)429 static struct sock *mptcp_nl_find_ssk(struct mptcp_sock *msk,
430 const struct mptcp_addr_info *local,
431 const struct mptcp_addr_info *remote)
432 {
433 struct mptcp_subflow_context *subflow;
434
435 if (local->family != remote->family)
436 return NULL;
437
438 mptcp_for_each_subflow(msk, subflow) {
439 const struct inet_sock *issk;
440 struct sock *ssk;
441
442 ssk = mptcp_subflow_tcp_sock(subflow);
443
444 if (local->family != ssk->sk_family)
445 continue;
446
447 issk = inet_sk(ssk);
448
449 switch (ssk->sk_family) {
450 case AF_INET:
451 if (issk->inet_saddr != local->addr.s_addr ||
452 issk->inet_daddr != remote->addr.s_addr)
453 continue;
454 break;
455 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
456 case AF_INET6: {
457 const struct ipv6_pinfo *pinfo = inet6_sk(ssk);
458
459 if (!ipv6_addr_equal(&local->addr6, &pinfo->saddr) ||
460 !ipv6_addr_equal(&remote->addr6, &ssk->sk_v6_daddr))
461 continue;
462 break;
463 }
464 #endif
465 default:
466 continue;
467 }
468
469 if (issk->inet_sport == local->port &&
470 issk->inet_dport == remote->port)
471 return ssk;
472 }
473
474 return NULL;
475 }
476
mptcp_nl_cmd_sf_destroy(struct sk_buff * skb,struct genl_info * info)477 int mptcp_nl_cmd_sf_destroy(struct sk_buff *skb, struct genl_info *info)
478 {
479 struct nlattr *raddr = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
480 struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
481 struct nlattr *laddr = info->attrs[MPTCP_PM_ATTR_ADDR];
482 struct mptcp_addr_info addr_l;
483 struct mptcp_addr_info addr_r;
484 struct mptcp_sock *msk;
485 struct sock *sk, *ssk;
486 int err = -EINVAL;
487 u32 token_val;
488
489 if (!laddr || !raddr || !token) {
490 GENL_SET_ERR_MSG(info, "missing required inputs");
491 return err;
492 }
493
494 token_val = nla_get_u32(token);
495
496 msk = mptcp_token_get_sock(genl_info_net(info), token_val);
497 if (!msk) {
498 NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
499 return err;
500 }
501
502 if (!mptcp_pm_is_userspace(msk)) {
503 GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
504 goto destroy_err;
505 }
506
507 err = mptcp_pm_parse_addr(laddr, info, &addr_l);
508 if (err < 0) {
509 NL_SET_ERR_MSG_ATTR(info->extack, laddr, "error parsing local addr");
510 goto destroy_err;
511 }
512
513 err = mptcp_pm_parse_addr(raddr, info, &addr_r);
514 if (err < 0) {
515 NL_SET_ERR_MSG_ATTR(info->extack, raddr, "error parsing remote addr");
516 goto destroy_err;
517 }
518
519 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
520 if (addr_l.family == AF_INET && ipv6_addr_v4mapped(&addr_r.addr6)) {
521 ipv6_addr_set_v4mapped(addr_l.addr.s_addr, &addr_l.addr6);
522 addr_l.family = AF_INET6;
523 }
524 if (addr_r.family == AF_INET && ipv6_addr_v4mapped(&addr_l.addr6)) {
525 ipv6_addr_set_v4mapped(addr_r.addr.s_addr, &addr_r.addr6);
526 addr_r.family = AF_INET6;
527 }
528 #endif
529 if (addr_l.family != addr_r.family) {
530 GENL_SET_ERR_MSG(info, "address families do not match");
531 err = -EINVAL;
532 goto destroy_err;
533 }
534
535 if (!addr_l.port || !addr_r.port) {
536 GENL_SET_ERR_MSG(info, "missing local or remote port");
537 err = -EINVAL;
538 goto destroy_err;
539 }
540
541 sk = (struct sock *)msk;
542 lock_sock(sk);
543 ssk = mptcp_nl_find_ssk(msk, &addr_l, &addr_r);
544 if (ssk) {
545 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
546 struct mptcp_pm_addr_entry entry = { .addr = addr_l };
547
548 spin_lock_bh(&msk->pm.lock);
549 mptcp_userspace_pm_delete_local_addr(msk, &entry);
550 spin_unlock_bh(&msk->pm.lock);
551 mptcp_subflow_shutdown(sk, ssk, RCV_SHUTDOWN | SEND_SHUTDOWN);
552 mptcp_close_ssk(sk, ssk, subflow);
553 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RMSUBFLOW);
554 err = 0;
555 } else {
556 err = -ESRCH;
557 }
558 release_sock(sk);
559
560 destroy_err:
561 sock_put((struct sock *)msk);
562 return err;
563 }
564
mptcp_userspace_pm_set_flags(struct net * net,struct nlattr * token,struct mptcp_pm_addr_entry * loc,struct mptcp_pm_addr_entry * rem,u8 bkup)565 int mptcp_userspace_pm_set_flags(struct net *net, struct nlattr *token,
566 struct mptcp_pm_addr_entry *loc,
567 struct mptcp_pm_addr_entry *rem, u8 bkup)
568 {
569 struct mptcp_pm_addr_entry *entry;
570 struct mptcp_sock *msk;
571 int ret = -EINVAL;
572 struct sock *sk;
573 u32 token_val;
574
575 token_val = nla_get_u32(token);
576
577 msk = mptcp_token_get_sock(net, token_val);
578 if (!msk)
579 return ret;
580
581 sk = (struct sock *)msk;
582
583 if (!mptcp_pm_is_userspace(msk))
584 goto set_flags_err;
585
586 if (loc->addr.family == AF_UNSPEC ||
587 rem->addr.family == AF_UNSPEC)
588 goto set_flags_err;
589
590 spin_lock_bh(&msk->pm.lock);
591 list_for_each_entry(entry, &msk->pm.userspace_pm_local_addr_list, list) {
592 if (mptcp_addresses_equal(&entry->addr, &loc->addr, false)) {
593 if (bkup)
594 entry->flags |= MPTCP_PM_ADDR_FLAG_BACKUP;
595 else
596 entry->flags &= ~MPTCP_PM_ADDR_FLAG_BACKUP;
597 }
598 }
599 spin_unlock_bh(&msk->pm.lock);
600
601 lock_sock(sk);
602 ret = mptcp_pm_nl_mp_prio_send_ack(msk, &loc->addr, &rem->addr, bkup);
603 release_sock(sk);
604
605 set_flags_err:
606 sock_put(sk);
607 return ret;
608 }
609