xref: /linux/net/mptcp/pm_userspace.c (revision 508ecc78b6c983a7921bee2f4bd22682f9f0396e)
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 
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 
28 static int mptcp_userspace_pm_append_new_local_addr(struct mptcp_sock *msk,
29 						    struct mptcp_pm_addr_entry *entry)
30 {
31 	DECLARE_BITMAP(id_bitmap, MPTCP_PM_MAX_ADDR_ID + 1);
32 	struct mptcp_pm_addr_entry *match = NULL;
33 	struct sock *sk = (struct sock *)msk;
34 	struct mptcp_pm_addr_entry *e;
35 	bool addr_match = false;
36 	bool id_match = false;
37 	int ret = -EINVAL;
38 
39 	bitmap_zero(id_bitmap, MPTCP_PM_MAX_ADDR_ID + 1);
40 
41 	spin_lock_bh(&msk->pm.lock);
42 	list_for_each_entry(e, &msk->pm.userspace_pm_local_addr_list, list) {
43 		addr_match = mptcp_addresses_equal(&e->addr, &entry->addr, true);
44 		if (addr_match && entry->addr.id == 0)
45 			entry->addr.id = e->addr.id;
46 		id_match = (e->addr.id == entry->addr.id);
47 		if (addr_match && id_match) {
48 			match = e;
49 			break;
50 		} else if (addr_match || id_match) {
51 			break;
52 		}
53 		__set_bit(e->addr.id, id_bitmap);
54 	}
55 
56 	if (!match && !addr_match && !id_match) {
57 		/* Memory for the entry is allocated from the
58 		 * sock option buffer.
59 		 */
60 		e = sock_kmalloc(sk, sizeof(*e), GFP_ATOMIC);
61 		if (!e) {
62 			ret = -ENOMEM;
63 			goto append_err;
64 		}
65 
66 		*e = *entry;
67 		if (!e->addr.id)
68 			e->addr.id = find_next_zero_bit(id_bitmap,
69 							MPTCP_PM_MAX_ADDR_ID + 1,
70 							1);
71 		list_add_tail_rcu(&e->list, &msk->pm.userspace_pm_local_addr_list);
72 		msk->pm.local_addr_used++;
73 		ret = e->addr.id;
74 	} else if (match) {
75 		ret = entry->addr.id;
76 	}
77 
78 append_err:
79 	spin_unlock_bh(&msk->pm.lock);
80 	return ret;
81 }
82 
83 /* If the subflow is closed from the other peer (not via a
84  * subflow destroy command then), we want to keep the entry
85  * not to assign the same ID to another address and to be
86  * able to send RM_ADDR after the removal of the subflow.
87  */
88 static int mptcp_userspace_pm_delete_local_addr(struct mptcp_sock *msk,
89 						struct mptcp_pm_addr_entry *addr)
90 {
91 	struct mptcp_pm_addr_entry *entry, *tmp;
92 
93 	list_for_each_entry_safe(entry, tmp, &msk->pm.userspace_pm_local_addr_list, list) {
94 		if (mptcp_addresses_equal(&entry->addr, &addr->addr, false)) {
95 			/* TODO: a refcount is needed because the entry can
96 			 * be used multiple times (e.g. fullmesh mode).
97 			 */
98 			list_del_rcu(&entry->list);
99 			kfree(entry);
100 			msk->pm.local_addr_used--;
101 			return 0;
102 		}
103 	}
104 
105 	return -EINVAL;
106 }
107 
108 int mptcp_userspace_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk,
109 						   unsigned int id,
110 						   u8 *flags, int *ifindex)
111 {
112 	struct mptcp_pm_addr_entry *entry, *match = NULL;
113 
114 	spin_lock_bh(&msk->pm.lock);
115 	list_for_each_entry(entry, &msk->pm.userspace_pm_local_addr_list, list) {
116 		if (id == entry->addr.id) {
117 			match = entry;
118 			break;
119 		}
120 	}
121 	spin_unlock_bh(&msk->pm.lock);
122 	if (match) {
123 		*flags = match->flags;
124 		*ifindex = match->ifindex;
125 	}
126 
127 	return 0;
128 }
129 
130 int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk,
131 				    struct mptcp_addr_info *skc)
132 {
133 	struct mptcp_pm_addr_entry *entry = NULL, *e, new_entry;
134 	__be16 msk_sport =  ((struct inet_sock *)
135 			     inet_sk((struct sock *)msk))->inet_sport;
136 
137 	spin_lock_bh(&msk->pm.lock);
138 	list_for_each_entry(e, &msk->pm.userspace_pm_local_addr_list, list) {
139 		if (mptcp_addresses_equal(&e->addr, skc, false)) {
140 			entry = e;
141 			break;
142 		}
143 	}
144 	spin_unlock_bh(&msk->pm.lock);
145 	if (entry)
146 		return entry->addr.id;
147 
148 	memset(&new_entry, 0, sizeof(struct mptcp_pm_addr_entry));
149 	new_entry.addr = *skc;
150 	new_entry.addr.id = 0;
151 	new_entry.flags = MPTCP_PM_ADDR_FLAG_IMPLICIT;
152 
153 	if (new_entry.addr.port == msk_sport)
154 		new_entry.addr.port = 0;
155 
156 	return mptcp_userspace_pm_append_new_local_addr(msk, &new_entry);
157 }
158 
159 int mptcp_pm_nl_announce_doit(struct sk_buff *skb, struct genl_info *info)
160 {
161 	struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
162 	struct nlattr *addr = info->attrs[MPTCP_PM_ATTR_ADDR];
163 	struct mptcp_pm_addr_entry addr_val;
164 	struct mptcp_sock *msk;
165 	int err = -EINVAL;
166 	struct sock *sk;
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 	sk = (struct sock *)msk;
183 
184 	if (!mptcp_pm_is_userspace(msk)) {
185 		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
186 		goto announce_err;
187 	}
188 
189 	err = mptcp_pm_parse_entry(addr, info, true, &addr_val);
190 	if (err < 0) {
191 		GENL_SET_ERR_MSG(info, "error parsing local address");
192 		goto announce_err;
193 	}
194 
195 	if (addr_val.addr.id == 0 || !(addr_val.flags & MPTCP_PM_ADDR_FLAG_SIGNAL)) {
196 		GENL_SET_ERR_MSG(info, "invalid addr id or flags");
197 		err = -EINVAL;
198 		goto announce_err;
199 	}
200 
201 	err = mptcp_userspace_pm_append_new_local_addr(msk, &addr_val);
202 	if (err < 0) {
203 		GENL_SET_ERR_MSG(info, "did not match address and id");
204 		goto announce_err;
205 	}
206 
207 	lock_sock(sk);
208 	spin_lock_bh(&msk->pm.lock);
209 
210 	if (mptcp_pm_alloc_anno_list(msk, &addr_val.addr)) {
211 		msk->pm.add_addr_signaled++;
212 		mptcp_pm_announce_addr(msk, &addr_val.addr, false);
213 		mptcp_pm_nl_addr_send_ack(msk);
214 	}
215 
216 	spin_unlock_bh(&msk->pm.lock);
217 	release_sock(sk);
218 
219 	err = 0;
220  announce_err:
221 	sock_put(sk);
222 	return err;
223 }
224 
225 static int mptcp_userspace_pm_remove_id_zero_address(struct mptcp_sock *msk,
226 						     struct genl_info *info)
227 {
228 	struct mptcp_rm_list list = { .nr = 0 };
229 	struct mptcp_subflow_context *subflow;
230 	struct sock *sk = (struct sock *)msk;
231 	bool has_id_0 = false;
232 	int err = -EINVAL;
233 
234 	lock_sock(sk);
235 	mptcp_for_each_subflow(msk, subflow) {
236 		if (subflow->local_id == 0) {
237 			has_id_0 = true;
238 			break;
239 		}
240 	}
241 	if (!has_id_0) {
242 		GENL_SET_ERR_MSG(info, "address with id 0 not found");
243 		goto remove_err;
244 	}
245 
246 	list.ids[list.nr++] = 0;
247 
248 	spin_lock_bh(&msk->pm.lock);
249 	mptcp_pm_remove_addr(msk, &list);
250 	spin_unlock_bh(&msk->pm.lock);
251 
252 	err = 0;
253 
254 remove_err:
255 	release_sock(sk);
256 	return err;
257 }
258 
259 int mptcp_pm_nl_remove_doit(struct sk_buff *skb, struct genl_info *info)
260 {
261 	struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
262 	struct nlattr *id = info->attrs[MPTCP_PM_ATTR_LOC_ID];
263 	struct mptcp_pm_addr_entry *match = NULL;
264 	struct mptcp_pm_addr_entry *entry;
265 	struct mptcp_sock *msk;
266 	LIST_HEAD(free_list);
267 	int err = -EINVAL;
268 	struct sock *sk;
269 	u32 token_val;
270 	u8 id_val;
271 
272 	if (!id || !token) {
273 		GENL_SET_ERR_MSG(info, "missing required inputs");
274 		return err;
275 	}
276 
277 	id_val = nla_get_u8(id);
278 	token_val = nla_get_u32(token);
279 
280 	msk = mptcp_token_get_sock(sock_net(skb->sk), token_val);
281 	if (!msk) {
282 		NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
283 		return err;
284 	}
285 
286 	sk = (struct sock *)msk;
287 
288 	if (!mptcp_pm_is_userspace(msk)) {
289 		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
290 		goto out;
291 	}
292 
293 	if (id_val == 0) {
294 		err = mptcp_userspace_pm_remove_id_zero_address(msk, info);
295 		goto out;
296 	}
297 
298 	lock_sock(sk);
299 
300 	list_for_each_entry(entry, &msk->pm.userspace_pm_local_addr_list, list) {
301 		if (entry->addr.id == id_val) {
302 			match = entry;
303 			break;
304 		}
305 	}
306 
307 	if (!match) {
308 		GENL_SET_ERR_MSG(info, "address with specified id not found");
309 		release_sock(sk);
310 		goto out;
311 	}
312 
313 	list_move(&match->list, &free_list);
314 
315 	mptcp_pm_remove_addrs(msk, &free_list);
316 
317 	release_sock(sk);
318 
319 	list_for_each_entry_safe(match, entry, &free_list, list) {
320 		sock_kfree_s(sk, match, sizeof(*match));
321 	}
322 
323 	err = 0;
324 out:
325 	sock_put(sk);
326 	return err;
327 }
328 
329 int mptcp_pm_nl_subflow_create_doit(struct sk_buff *skb, struct genl_info *info)
330 {
331 	struct nlattr *raddr = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
332 	struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
333 	struct nlattr *laddr = info->attrs[MPTCP_PM_ATTR_ADDR];
334 	struct mptcp_pm_addr_entry local = { 0 };
335 	struct mptcp_addr_info addr_r;
336 	struct mptcp_addr_info addr_l;
337 	struct mptcp_sock *msk;
338 	int err = -EINVAL;
339 	struct sock *sk;
340 	u32 token_val;
341 
342 	if (!laddr || !raddr || !token) {
343 		GENL_SET_ERR_MSG(info, "missing required inputs");
344 		return err;
345 	}
346 
347 	token_val = nla_get_u32(token);
348 
349 	msk = mptcp_token_get_sock(genl_info_net(info), token_val);
350 	if (!msk) {
351 		NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
352 		return err;
353 	}
354 
355 	sk = (struct sock *)msk;
356 
357 	if (!mptcp_pm_is_userspace(msk)) {
358 		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
359 		goto create_err;
360 	}
361 
362 	err = mptcp_pm_parse_addr(laddr, info, &addr_l);
363 	if (err < 0) {
364 		NL_SET_ERR_MSG_ATTR(info->extack, laddr, "error parsing local addr");
365 		goto create_err;
366 	}
367 
368 	err = mptcp_pm_parse_addr(raddr, info, &addr_r);
369 	if (err < 0) {
370 		NL_SET_ERR_MSG_ATTR(info->extack, raddr, "error parsing remote addr");
371 		goto create_err;
372 	}
373 
374 	if (!mptcp_pm_addr_families_match(sk, &addr_l, &addr_r)) {
375 		GENL_SET_ERR_MSG(info, "families mismatch");
376 		err = -EINVAL;
377 		goto create_err;
378 	}
379 
380 	local.addr = addr_l;
381 	err = mptcp_userspace_pm_append_new_local_addr(msk, &local);
382 	if (err < 0) {
383 		GENL_SET_ERR_MSG(info, "did not match address and id");
384 		goto create_err;
385 	}
386 
387 	lock_sock(sk);
388 
389 	err = __mptcp_subflow_connect(sk, &addr_l, &addr_r);
390 
391 	release_sock(sk);
392 
393 	spin_lock_bh(&msk->pm.lock);
394 	if (err)
395 		mptcp_userspace_pm_delete_local_addr(msk, &local);
396 	else
397 		msk->pm.subflows++;
398 	spin_unlock_bh(&msk->pm.lock);
399 
400  create_err:
401 	sock_put(sk);
402 	return err;
403 }
404 
405 static struct sock *mptcp_nl_find_ssk(struct mptcp_sock *msk,
406 				      const struct mptcp_addr_info *local,
407 				      const struct mptcp_addr_info *remote)
408 {
409 	struct mptcp_subflow_context *subflow;
410 
411 	if (local->family != remote->family)
412 		return NULL;
413 
414 	mptcp_for_each_subflow(msk, subflow) {
415 		const struct inet_sock *issk;
416 		struct sock *ssk;
417 
418 		ssk = mptcp_subflow_tcp_sock(subflow);
419 
420 		if (local->family != ssk->sk_family)
421 			continue;
422 
423 		issk = inet_sk(ssk);
424 
425 		switch (ssk->sk_family) {
426 		case AF_INET:
427 			if (issk->inet_saddr != local->addr.s_addr ||
428 			    issk->inet_daddr != remote->addr.s_addr)
429 				continue;
430 			break;
431 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
432 		case AF_INET6: {
433 			const struct ipv6_pinfo *pinfo = inet6_sk(ssk);
434 
435 			if (!ipv6_addr_equal(&local->addr6, &pinfo->saddr) ||
436 			    !ipv6_addr_equal(&remote->addr6, &ssk->sk_v6_daddr))
437 				continue;
438 			break;
439 		}
440 #endif
441 		default:
442 			continue;
443 		}
444 
445 		if (issk->inet_sport == local->port &&
446 		    issk->inet_dport == remote->port)
447 			return ssk;
448 	}
449 
450 	return NULL;
451 }
452 
453 int mptcp_pm_nl_subflow_destroy_doit(struct sk_buff *skb, struct genl_info *info)
454 {
455 	struct nlattr *raddr = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
456 	struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
457 	struct nlattr *laddr = info->attrs[MPTCP_PM_ATTR_ADDR];
458 	struct mptcp_addr_info addr_l;
459 	struct mptcp_addr_info addr_r;
460 	struct mptcp_sock *msk;
461 	struct sock *sk, *ssk;
462 	int err = -EINVAL;
463 	u32 token_val;
464 
465 	if (!laddr || !raddr || !token) {
466 		GENL_SET_ERR_MSG(info, "missing required inputs");
467 		return err;
468 	}
469 
470 	token_val = nla_get_u32(token);
471 
472 	msk = mptcp_token_get_sock(genl_info_net(info), token_val);
473 	if (!msk) {
474 		NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
475 		return err;
476 	}
477 
478 	sk = (struct sock *)msk;
479 
480 	if (!mptcp_pm_is_userspace(msk)) {
481 		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
482 		goto destroy_err;
483 	}
484 
485 	err = mptcp_pm_parse_addr(laddr, info, &addr_l);
486 	if (err < 0) {
487 		NL_SET_ERR_MSG_ATTR(info->extack, laddr, "error parsing local addr");
488 		goto destroy_err;
489 	}
490 
491 	err = mptcp_pm_parse_addr(raddr, info, &addr_r);
492 	if (err < 0) {
493 		NL_SET_ERR_MSG_ATTR(info->extack, raddr, "error parsing remote addr");
494 		goto destroy_err;
495 	}
496 
497 	if (addr_l.family != addr_r.family) {
498 		GENL_SET_ERR_MSG(info, "address families do not match");
499 		err = -EINVAL;
500 		goto destroy_err;
501 	}
502 
503 	if (!addr_l.port || !addr_r.port) {
504 		GENL_SET_ERR_MSG(info, "missing local or remote port");
505 		err = -EINVAL;
506 		goto destroy_err;
507 	}
508 
509 	lock_sock(sk);
510 	ssk = mptcp_nl_find_ssk(msk, &addr_l, &addr_r);
511 	if (ssk) {
512 		struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
513 		struct mptcp_pm_addr_entry entry = { .addr = addr_l };
514 
515 		spin_lock_bh(&msk->pm.lock);
516 		mptcp_userspace_pm_delete_local_addr(msk, &entry);
517 		spin_unlock_bh(&msk->pm.lock);
518 		mptcp_subflow_shutdown(sk, ssk, RCV_SHUTDOWN | SEND_SHUTDOWN);
519 		mptcp_close_ssk(sk, ssk, subflow);
520 		MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RMSUBFLOW);
521 		err = 0;
522 	} else {
523 		err = -ESRCH;
524 	}
525 	release_sock(sk);
526 
527 destroy_err:
528 	sock_put(sk);
529 	return err;
530 }
531 
532 int mptcp_userspace_pm_set_flags(struct net *net, struct nlattr *token,
533 				 struct mptcp_pm_addr_entry *loc,
534 				 struct mptcp_pm_addr_entry *rem, u8 bkup)
535 {
536 	struct mptcp_sock *msk;
537 	int ret = -EINVAL;
538 	struct sock *sk;
539 	u32 token_val;
540 
541 	token_val = nla_get_u32(token);
542 
543 	msk = mptcp_token_get_sock(net, token_val);
544 	if (!msk)
545 		return ret;
546 
547 	sk = (struct sock *)msk;
548 
549 	if (!mptcp_pm_is_userspace(msk))
550 		goto set_flags_err;
551 
552 	if (loc->addr.family == AF_UNSPEC ||
553 	    rem->addr.family == AF_UNSPEC)
554 		goto set_flags_err;
555 
556 	lock_sock(sk);
557 	ret = mptcp_pm_nl_mp_prio_send_ack(msk, &loc->addr, &rem->addr, bkup);
558 	release_sock(sk);
559 
560 set_flags_err:
561 	sock_put(sk);
562 	return ret;
563 }
564