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
94 list_for_each_entry_safe(entry, tmp, &msk->pm.userspace_pm_local_addr_list, list) {
95 if (mptcp_addresses_equal(&entry->addr, &addr->addr, false)) {
96 /* TODO: a refcount is needed because the entry can
97 * be used multiple times (e.g. fullmesh mode).
98 */
99 list_del_rcu(&entry->list);
100 kfree(entry);
101 msk->pm.local_addr_used--;
102 return 0;
103 }
104 }
105
106 return -EINVAL;
107 }
108
mptcp_userspace_pm_get_flags_and_ifindex_by_id(struct mptcp_sock * msk,unsigned int id,u8 * flags,int * ifindex)109 int mptcp_userspace_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk,
110 unsigned int id,
111 u8 *flags, int *ifindex)
112 {
113 struct mptcp_pm_addr_entry *entry, *match = NULL;
114
115 spin_lock_bh(&msk->pm.lock);
116 list_for_each_entry(entry, &msk->pm.userspace_pm_local_addr_list, list) {
117 if (id == entry->addr.id) {
118 match = entry;
119 break;
120 }
121 }
122 spin_unlock_bh(&msk->pm.lock);
123 if (match) {
124 *flags = match->flags;
125 *ifindex = match->ifindex;
126 }
127
128 return 0;
129 }
130
mptcp_userspace_pm_get_local_id(struct mptcp_sock * msk,struct mptcp_addr_info * skc)131 int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk,
132 struct mptcp_addr_info *skc)
133 {
134 struct mptcp_pm_addr_entry *entry = NULL, *e, new_entry;
135 __be16 msk_sport = ((struct inet_sock *)
136 inet_sk((struct sock *)msk))->inet_sport;
137
138 spin_lock_bh(&msk->pm.lock);
139 list_for_each_entry(e, &msk->pm.userspace_pm_local_addr_list, list) {
140 if (mptcp_addresses_equal(&e->addr, skc, false)) {
141 entry = e;
142 break;
143 }
144 }
145 spin_unlock_bh(&msk->pm.lock);
146 if (entry)
147 return entry->addr.id;
148
149 memset(&new_entry, 0, sizeof(struct mptcp_pm_addr_entry));
150 new_entry.addr = *skc;
151 new_entry.addr.id = 0;
152 new_entry.flags = MPTCP_PM_ADDR_FLAG_IMPLICIT;
153
154 if (new_entry.addr.port == msk_sport)
155 new_entry.addr.port = 0;
156
157 return mptcp_userspace_pm_append_new_local_addr(msk, &new_entry, true);
158 }
159
mptcp_userspace_pm_is_backup(struct mptcp_sock * msk,struct mptcp_addr_info * skc)160 bool mptcp_userspace_pm_is_backup(struct mptcp_sock *msk,
161 struct mptcp_addr_info *skc)
162 {
163 struct mptcp_pm_addr_entry *entry;
164 bool backup = false;
165
166 spin_lock_bh(&msk->pm.lock);
167 list_for_each_entry(entry, &msk->pm.userspace_pm_local_addr_list, list) {
168 if (mptcp_addresses_equal(&entry->addr, skc, false)) {
169 backup = !!(entry->flags & MPTCP_PM_ADDR_FLAG_BACKUP);
170 break;
171 }
172 }
173 spin_unlock_bh(&msk->pm.lock);
174
175 return backup;
176 }
177
mptcp_nl_cmd_announce(struct sk_buff * skb,struct genl_info * info)178 int mptcp_nl_cmd_announce(struct sk_buff *skb, struct genl_info *info)
179 {
180 struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
181 struct nlattr *addr = info->attrs[MPTCP_PM_ATTR_ADDR];
182 struct mptcp_pm_addr_entry addr_val;
183 struct mptcp_sock *msk;
184 int err = -EINVAL;
185 u32 token_val;
186
187 if (!addr || !token) {
188 GENL_SET_ERR_MSG(info, "missing required inputs");
189 return err;
190 }
191
192 token_val = nla_get_u32(token);
193
194 msk = mptcp_token_get_sock(sock_net(skb->sk), token_val);
195 if (!msk) {
196 NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
197 return err;
198 }
199
200 if (!mptcp_pm_is_userspace(msk)) {
201 GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
202 goto announce_err;
203 }
204
205 err = mptcp_pm_parse_entry(addr, info, true, &addr_val);
206 if (err < 0) {
207 GENL_SET_ERR_MSG(info, "error parsing local address");
208 goto announce_err;
209 }
210
211 if (addr_val.addr.id == 0 || !(addr_val.flags & MPTCP_PM_ADDR_FLAG_SIGNAL)) {
212 GENL_SET_ERR_MSG(info, "invalid addr id or flags");
213 err = -EINVAL;
214 goto announce_err;
215 }
216
217 err = mptcp_userspace_pm_append_new_local_addr(msk, &addr_val, false);
218 if (err < 0) {
219 GENL_SET_ERR_MSG(info, "did not match address and id");
220 goto announce_err;
221 }
222
223 lock_sock((struct sock *)msk);
224 spin_lock_bh(&msk->pm.lock);
225
226 if (mptcp_pm_alloc_anno_list(msk, &addr_val.addr)) {
227 msk->pm.add_addr_signaled++;
228 mptcp_pm_announce_addr(msk, &addr_val.addr, false);
229 mptcp_pm_nl_addr_send_ack(msk);
230 }
231
232 spin_unlock_bh(&msk->pm.lock);
233 release_sock((struct sock *)msk);
234
235 err = 0;
236 announce_err:
237 sock_put((struct sock *)msk);
238 return err;
239 }
240
mptcp_userspace_pm_remove_id_zero_address(struct mptcp_sock * msk,struct genl_info * info)241 static int mptcp_userspace_pm_remove_id_zero_address(struct mptcp_sock *msk,
242 struct genl_info *info)
243 {
244 struct mptcp_rm_list list = { .nr = 0 };
245 struct mptcp_subflow_context *subflow;
246 struct sock *sk = (struct sock *)msk;
247 bool has_id_0 = false;
248 int err = -EINVAL;
249
250 lock_sock(sk);
251 mptcp_for_each_subflow(msk, subflow) {
252 if (subflow->local_id == 0) {
253 has_id_0 = true;
254 break;
255 }
256 }
257 if (!has_id_0) {
258 GENL_SET_ERR_MSG(info, "address with id 0 not found");
259 goto remove_err;
260 }
261
262 list.ids[list.nr++] = 0;
263
264 spin_lock_bh(&msk->pm.lock);
265 mptcp_pm_remove_addr(msk, &list);
266 spin_unlock_bh(&msk->pm.lock);
267
268 err = 0;
269
270 remove_err:
271 release_sock(sk);
272 return err;
273 }
274
mptcp_nl_cmd_remove(struct sk_buff * skb,struct genl_info * info)275 int mptcp_nl_cmd_remove(struct sk_buff *skb, struct genl_info *info)
276 {
277 struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
278 struct nlattr *id = info->attrs[MPTCP_PM_ATTR_LOC_ID];
279 struct mptcp_pm_addr_entry *match = NULL;
280 struct mptcp_pm_addr_entry *entry;
281 struct mptcp_sock *msk;
282 LIST_HEAD(free_list);
283 int err = -EINVAL;
284 u32 token_val;
285 u8 id_val;
286
287 if (!id || !token) {
288 GENL_SET_ERR_MSG(info, "missing required inputs");
289 return err;
290 }
291
292 id_val = nla_get_u8(id);
293 token_val = nla_get_u32(token);
294
295 msk = mptcp_token_get_sock(sock_net(skb->sk), token_val);
296 if (!msk) {
297 NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
298 return err;
299 }
300
301 if (!mptcp_pm_is_userspace(msk)) {
302 GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
303 goto remove_err;
304 }
305
306 if (id_val == 0) {
307 err = mptcp_userspace_pm_remove_id_zero_address(msk, info);
308 goto remove_err;
309 }
310
311 lock_sock((struct sock *)msk);
312
313 list_for_each_entry(entry, &msk->pm.userspace_pm_local_addr_list, list) {
314 if (entry->addr.id == id_val) {
315 match = entry;
316 break;
317 }
318 }
319
320 if (!match) {
321 GENL_SET_ERR_MSG(info, "address with specified id not found");
322 release_sock((struct sock *)msk);
323 goto remove_err;
324 }
325
326 list_move(&match->list, &free_list);
327
328 mptcp_pm_remove_addrs(msk, &free_list);
329
330 release_sock((struct sock *)msk);
331
332 list_for_each_entry_safe(match, entry, &free_list, list) {
333 sock_kfree_s((struct sock *)msk, match, sizeof(*match));
334 }
335
336 err = 0;
337 remove_err:
338 sock_put((struct sock *)msk);
339 return err;
340 }
341
mptcp_nl_cmd_sf_create(struct sk_buff * skb,struct genl_info * info)342 int mptcp_nl_cmd_sf_create(struct sk_buff *skb, struct genl_info *info)
343 {
344 struct nlattr *raddr = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
345 struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
346 struct nlattr *laddr = info->attrs[MPTCP_PM_ATTR_ADDR];
347 struct mptcp_pm_addr_entry local = { 0 };
348 struct mptcp_addr_info addr_r;
349 struct mptcp_addr_info addr_l;
350 struct mptcp_sock *msk;
351 int err = -EINVAL;
352 struct sock *sk;
353 u32 token_val;
354
355 if (!laddr || !raddr || !token) {
356 GENL_SET_ERR_MSG(info, "missing required inputs");
357 return err;
358 }
359
360 token_val = nla_get_u32(token);
361
362 msk = mptcp_token_get_sock(genl_info_net(info), token_val);
363 if (!msk) {
364 NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
365 return err;
366 }
367
368 if (!mptcp_pm_is_userspace(msk)) {
369 GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
370 goto create_err;
371 }
372
373 err = mptcp_pm_parse_addr(laddr, info, &addr_l);
374 if (err < 0) {
375 NL_SET_ERR_MSG_ATTR(info->extack, laddr, "error parsing local addr");
376 goto create_err;
377 }
378
379 err = mptcp_pm_parse_addr(raddr, info, &addr_r);
380 if (err < 0) {
381 NL_SET_ERR_MSG_ATTR(info->extack, raddr, "error parsing remote addr");
382 goto create_err;
383 }
384
385 sk = (struct sock *)msk;
386
387 if (!mptcp_pm_addr_families_match(sk, &addr_l, &addr_r)) {
388 GENL_SET_ERR_MSG(info, "families mismatch");
389 err = -EINVAL;
390 goto create_err;
391 }
392
393 local.addr = addr_l;
394 err = mptcp_userspace_pm_append_new_local_addr(msk, &local, false);
395 if (err < 0) {
396 GENL_SET_ERR_MSG(info, "did not match address and id");
397 goto create_err;
398 }
399
400 lock_sock(sk);
401
402 err = __mptcp_subflow_connect(sk, &addr_l, &addr_r);
403
404 release_sock(sk);
405
406 spin_lock_bh(&msk->pm.lock);
407 if (err)
408 mptcp_userspace_pm_delete_local_addr(msk, &local);
409 else
410 msk->pm.subflows++;
411 spin_unlock_bh(&msk->pm.lock);
412
413 create_err:
414 sock_put((struct sock *)msk);
415 return err;
416 }
417
mptcp_nl_find_ssk(struct mptcp_sock * msk,const struct mptcp_addr_info * local,const struct mptcp_addr_info * remote)418 static struct sock *mptcp_nl_find_ssk(struct mptcp_sock *msk,
419 const struct mptcp_addr_info *local,
420 const struct mptcp_addr_info *remote)
421 {
422 struct mptcp_subflow_context *subflow;
423
424 if (local->family != remote->family)
425 return NULL;
426
427 mptcp_for_each_subflow(msk, subflow) {
428 const struct inet_sock *issk;
429 struct sock *ssk;
430
431 ssk = mptcp_subflow_tcp_sock(subflow);
432
433 if (local->family != ssk->sk_family)
434 continue;
435
436 issk = inet_sk(ssk);
437
438 switch (ssk->sk_family) {
439 case AF_INET:
440 if (issk->inet_saddr != local->addr.s_addr ||
441 issk->inet_daddr != remote->addr.s_addr)
442 continue;
443 break;
444 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
445 case AF_INET6: {
446 const struct ipv6_pinfo *pinfo = inet6_sk(ssk);
447
448 if (!ipv6_addr_equal(&local->addr6, &pinfo->saddr) ||
449 !ipv6_addr_equal(&remote->addr6, &ssk->sk_v6_daddr))
450 continue;
451 break;
452 }
453 #endif
454 default:
455 continue;
456 }
457
458 if (issk->inet_sport == local->port &&
459 issk->inet_dport == remote->port)
460 return ssk;
461 }
462
463 return NULL;
464 }
465
mptcp_nl_cmd_sf_destroy(struct sk_buff * skb,struct genl_info * info)466 int mptcp_nl_cmd_sf_destroy(struct sk_buff *skb, struct genl_info *info)
467 {
468 struct nlattr *raddr = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
469 struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
470 struct nlattr *laddr = info->attrs[MPTCP_PM_ATTR_ADDR];
471 struct mptcp_addr_info addr_l;
472 struct mptcp_addr_info addr_r;
473 struct mptcp_sock *msk;
474 struct sock *sk, *ssk;
475 int err = -EINVAL;
476 u32 token_val;
477
478 if (!laddr || !raddr || !token) {
479 GENL_SET_ERR_MSG(info, "missing required inputs");
480 return err;
481 }
482
483 token_val = nla_get_u32(token);
484
485 msk = mptcp_token_get_sock(genl_info_net(info), token_val);
486 if (!msk) {
487 NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
488 return err;
489 }
490
491 if (!mptcp_pm_is_userspace(msk)) {
492 GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
493 goto destroy_err;
494 }
495
496 err = mptcp_pm_parse_addr(laddr, info, &addr_l);
497 if (err < 0) {
498 NL_SET_ERR_MSG_ATTR(info->extack, laddr, "error parsing local addr");
499 goto destroy_err;
500 }
501
502 err = mptcp_pm_parse_addr(raddr, info, &addr_r);
503 if (err < 0) {
504 NL_SET_ERR_MSG_ATTR(info->extack, raddr, "error parsing remote addr");
505 goto destroy_err;
506 }
507
508 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
509 if (addr_l.family == AF_INET && ipv6_addr_v4mapped(&addr_r.addr6)) {
510 ipv6_addr_set_v4mapped(addr_l.addr.s_addr, &addr_l.addr6);
511 addr_l.family = AF_INET6;
512 }
513 if (addr_r.family == AF_INET && ipv6_addr_v4mapped(&addr_l.addr6)) {
514 ipv6_addr_set_v4mapped(addr_r.addr.s_addr, &addr_r.addr6);
515 addr_r.family = AF_INET6;
516 }
517 #endif
518 if (addr_l.family != addr_r.family) {
519 GENL_SET_ERR_MSG(info, "address families do not match");
520 err = -EINVAL;
521 goto destroy_err;
522 }
523
524 if (!addr_l.port || !addr_r.port) {
525 GENL_SET_ERR_MSG(info, "missing local or remote port");
526 err = -EINVAL;
527 goto destroy_err;
528 }
529
530 sk = (struct sock *)msk;
531 lock_sock(sk);
532 ssk = mptcp_nl_find_ssk(msk, &addr_l, &addr_r);
533 if (ssk) {
534 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
535 struct mptcp_pm_addr_entry entry = { .addr = addr_l };
536
537 spin_lock_bh(&msk->pm.lock);
538 mptcp_userspace_pm_delete_local_addr(msk, &entry);
539 spin_unlock_bh(&msk->pm.lock);
540 mptcp_subflow_shutdown(sk, ssk, RCV_SHUTDOWN | SEND_SHUTDOWN);
541 mptcp_close_ssk(sk, ssk, subflow);
542 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RMSUBFLOW);
543 err = 0;
544 } else {
545 err = -ESRCH;
546 }
547 release_sock(sk);
548
549 destroy_err:
550 sock_put((struct sock *)msk);
551 return err;
552 }
553
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)554 int mptcp_userspace_pm_set_flags(struct net *net, struct nlattr *token,
555 struct mptcp_pm_addr_entry *loc,
556 struct mptcp_pm_addr_entry *rem, u8 bkup)
557 {
558 struct mptcp_sock *msk;
559 int ret = -EINVAL;
560 u32 token_val;
561
562 token_val = nla_get_u32(token);
563
564 msk = mptcp_token_get_sock(net, token_val);
565 if (!msk)
566 return ret;
567
568 if (!mptcp_pm_is_userspace(msk))
569 goto set_flags_err;
570
571 if (loc->addr.family == AF_UNSPEC ||
572 rem->addr.family == AF_UNSPEC)
573 goto set_flags_err;
574
575 lock_sock((struct sock *)msk);
576 ret = mptcp_pm_nl_mp_prio_send_ack(msk, &loc->addr, &rem->addr, bkup);
577 release_sock((struct sock *)msk);
578
579 set_flags_err:
580 sock_put((struct sock *)msk);
581 return ret;
582 }
583