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