xref: /openbmc/linux/net/mptcp/pm_userspace.c (revision cc698db4)
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 						    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  */
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 
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 
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 
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 
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 
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 
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 
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 
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 (addr_l.family != addr_r.family) {
491 		GENL_SET_ERR_MSG(info, "address families do not match");
492 		err = -EINVAL;
493 		goto destroy_err;
494 	}
495 
496 	if (!addr_l.port || !addr_r.port) {
497 		GENL_SET_ERR_MSG(info, "missing local or remote port");
498 		err = -EINVAL;
499 		goto destroy_err;
500 	}
501 
502 	sk = (struct sock *)msk;
503 	lock_sock(sk);
504 	ssk = mptcp_nl_find_ssk(msk, &addr_l, &addr_r);
505 	if (ssk) {
506 		struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
507 		struct mptcp_pm_addr_entry entry = { .addr = addr_l };
508 
509 		spin_lock_bh(&msk->pm.lock);
510 		mptcp_userspace_pm_delete_local_addr(msk, &entry);
511 		spin_unlock_bh(&msk->pm.lock);
512 		mptcp_subflow_shutdown(sk, ssk, RCV_SHUTDOWN | SEND_SHUTDOWN);
513 		mptcp_close_ssk(sk, ssk, subflow);
514 		MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RMSUBFLOW);
515 		err = 0;
516 	} else {
517 		err = -ESRCH;
518 	}
519 	release_sock(sk);
520 
521 destroy_err:
522 	sock_put((struct sock *)msk);
523 	return err;
524 }
525 
526 int mptcp_userspace_pm_set_flags(struct net *net, struct nlattr *token,
527 				 struct mptcp_pm_addr_entry *loc,
528 				 struct mptcp_pm_addr_entry *rem, u8 bkup)
529 {
530 	struct mptcp_sock *msk;
531 	int ret = -EINVAL;
532 	u32 token_val;
533 
534 	token_val = nla_get_u32(token);
535 
536 	msk = mptcp_token_get_sock(net, token_val);
537 	if (!msk)
538 		return ret;
539 
540 	if (!mptcp_pm_is_userspace(msk))
541 		goto set_flags_err;
542 
543 	if (loc->addr.family == AF_UNSPEC ||
544 	    rem->addr.family == AF_UNSPEC)
545 		goto set_flags_err;
546 
547 	lock_sock((struct sock *)msk);
548 	ret = mptcp_pm_nl_mp_prio_send_ack(msk, &loc->addr, &rem->addr, bkup);
549 	release_sock((struct sock *)msk);
550 
551 set_flags_err:
552 	sock_put((struct sock *)msk);
553 	return ret;
554 }
555