xref: /openbmc/linux/net/mptcp/pm_userspace.c (revision 19758688)
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_nl_cmd_announce(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 	u32 token_val;
167 
168 	if (!addr || !token) {
169 		GENL_SET_ERR_MSG(info, "missing required inputs");
170 		return err;
171 	}
172 
173 	token_val = nla_get_u32(token);
174 
175 	msk = mptcp_token_get_sock(sock_net(skb->sk), token_val);
176 	if (!msk) {
177 		NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
178 		return err;
179 	}
180 
181 	if (!mptcp_pm_is_userspace(msk)) {
182 		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
183 		goto announce_err;
184 	}
185 
186 	err = mptcp_pm_parse_entry(addr, info, true, &addr_val);
187 	if (err < 0) {
188 		GENL_SET_ERR_MSG(info, "error parsing local address");
189 		goto announce_err;
190 	}
191 
192 	if (addr_val.addr.id == 0 || !(addr_val.flags & MPTCP_PM_ADDR_FLAG_SIGNAL)) {
193 		GENL_SET_ERR_MSG(info, "invalid addr id or flags");
194 		err = -EINVAL;
195 		goto announce_err;
196 	}
197 
198 	err = mptcp_userspace_pm_append_new_local_addr(msk, &addr_val);
199 	if (err < 0) {
200 		GENL_SET_ERR_MSG(info, "did not match address and id");
201 		goto announce_err;
202 	}
203 
204 	lock_sock((struct sock *)msk);
205 	spin_lock_bh(&msk->pm.lock);
206 
207 	if (mptcp_pm_alloc_anno_list(msk, &addr_val.addr)) {
208 		msk->pm.add_addr_signaled++;
209 		mptcp_pm_announce_addr(msk, &addr_val.addr, false);
210 		mptcp_pm_nl_addr_send_ack(msk);
211 	}
212 
213 	spin_unlock_bh(&msk->pm.lock);
214 	release_sock((struct sock *)msk);
215 
216 	err = 0;
217  announce_err:
218 	sock_put((struct sock *)msk);
219 	return err;
220 }
221 
222 int mptcp_nl_cmd_remove(struct sk_buff *skb, struct genl_info *info)
223 {
224 	struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
225 	struct nlattr *id = info->attrs[MPTCP_PM_ATTR_LOC_ID];
226 	struct mptcp_pm_addr_entry *match = NULL;
227 	struct mptcp_pm_addr_entry *entry;
228 	struct mptcp_sock *msk;
229 	LIST_HEAD(free_list);
230 	int err = -EINVAL;
231 	u32 token_val;
232 	u8 id_val;
233 
234 	if (!id || !token) {
235 		GENL_SET_ERR_MSG(info, "missing required inputs");
236 		return err;
237 	}
238 
239 	id_val = nla_get_u8(id);
240 	token_val = nla_get_u32(token);
241 
242 	msk = mptcp_token_get_sock(sock_net(skb->sk), token_val);
243 	if (!msk) {
244 		NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
245 		return err;
246 	}
247 
248 	if (!mptcp_pm_is_userspace(msk)) {
249 		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
250 		goto remove_err;
251 	}
252 
253 	lock_sock((struct sock *)msk);
254 
255 	list_for_each_entry(entry, &msk->pm.userspace_pm_local_addr_list, list) {
256 		if (entry->addr.id == id_val) {
257 			match = entry;
258 			break;
259 		}
260 	}
261 
262 	if (!match) {
263 		GENL_SET_ERR_MSG(info, "address with specified id not found");
264 		release_sock((struct sock *)msk);
265 		goto remove_err;
266 	}
267 
268 	list_move(&match->list, &free_list);
269 
270 	mptcp_pm_remove_addrs(msk, &free_list);
271 
272 	release_sock((struct sock *)msk);
273 
274 	list_for_each_entry_safe(match, entry, &free_list, list) {
275 		sock_kfree_s((struct sock *)msk, match, sizeof(*match));
276 	}
277 
278 	err = 0;
279  remove_err:
280 	sock_put((struct sock *)msk);
281 	return err;
282 }
283 
284 int mptcp_nl_cmd_sf_create(struct sk_buff *skb, struct genl_info *info)
285 {
286 	struct nlattr *raddr = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
287 	struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
288 	struct nlattr *laddr = info->attrs[MPTCP_PM_ATTR_ADDR];
289 	struct mptcp_pm_addr_entry local = { 0 };
290 	struct mptcp_addr_info addr_r;
291 	struct mptcp_addr_info addr_l;
292 	struct mptcp_sock *msk;
293 	int err = -EINVAL;
294 	struct sock *sk;
295 	u32 token_val;
296 
297 	if (!laddr || !raddr || !token) {
298 		GENL_SET_ERR_MSG(info, "missing required inputs");
299 		return err;
300 	}
301 
302 	token_val = nla_get_u32(token);
303 
304 	msk = mptcp_token_get_sock(genl_info_net(info), token_val);
305 	if (!msk) {
306 		NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
307 		return err;
308 	}
309 
310 	if (!mptcp_pm_is_userspace(msk)) {
311 		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
312 		goto create_err;
313 	}
314 
315 	err = mptcp_pm_parse_addr(laddr, info, &addr_l);
316 	if (err < 0) {
317 		NL_SET_ERR_MSG_ATTR(info->extack, laddr, "error parsing local addr");
318 		goto create_err;
319 	}
320 
321 	err = mptcp_pm_parse_addr(raddr, info, &addr_r);
322 	if (err < 0) {
323 		NL_SET_ERR_MSG_ATTR(info->extack, raddr, "error parsing remote addr");
324 		goto create_err;
325 	}
326 
327 	sk = (struct sock *)msk;
328 
329 	if (!mptcp_pm_addr_families_match(sk, &addr_l, &addr_r)) {
330 		GENL_SET_ERR_MSG(info, "families mismatch");
331 		err = -EINVAL;
332 		goto create_err;
333 	}
334 
335 	local.addr = addr_l;
336 	err = mptcp_userspace_pm_append_new_local_addr(msk, &local);
337 	if (err < 0) {
338 		GENL_SET_ERR_MSG(info, "did not match address and id");
339 		goto create_err;
340 	}
341 
342 	lock_sock(sk);
343 
344 	err = __mptcp_subflow_connect(sk, &addr_l, &addr_r);
345 
346 	release_sock(sk);
347 
348 	spin_lock_bh(&msk->pm.lock);
349 	if (err)
350 		mptcp_userspace_pm_delete_local_addr(msk, &local);
351 	else
352 		msk->pm.subflows++;
353 	spin_unlock_bh(&msk->pm.lock);
354 
355  create_err:
356 	sock_put((struct sock *)msk);
357 	return err;
358 }
359 
360 static struct sock *mptcp_nl_find_ssk(struct mptcp_sock *msk,
361 				      const struct mptcp_addr_info *local,
362 				      const struct mptcp_addr_info *remote)
363 {
364 	struct mptcp_subflow_context *subflow;
365 
366 	if (local->family != remote->family)
367 		return NULL;
368 
369 	mptcp_for_each_subflow(msk, subflow) {
370 		const struct inet_sock *issk;
371 		struct sock *ssk;
372 
373 		ssk = mptcp_subflow_tcp_sock(subflow);
374 
375 		if (local->family != ssk->sk_family)
376 			continue;
377 
378 		issk = inet_sk(ssk);
379 
380 		switch (ssk->sk_family) {
381 		case AF_INET:
382 			if (issk->inet_saddr != local->addr.s_addr ||
383 			    issk->inet_daddr != remote->addr.s_addr)
384 				continue;
385 			break;
386 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
387 		case AF_INET6: {
388 			const struct ipv6_pinfo *pinfo = inet6_sk(ssk);
389 
390 			if (!ipv6_addr_equal(&local->addr6, &pinfo->saddr) ||
391 			    !ipv6_addr_equal(&remote->addr6, &ssk->sk_v6_daddr))
392 				continue;
393 			break;
394 		}
395 #endif
396 		default:
397 			continue;
398 		}
399 
400 		if (issk->inet_sport == local->port &&
401 		    issk->inet_dport == remote->port)
402 			return ssk;
403 	}
404 
405 	return NULL;
406 }
407 
408 int mptcp_nl_cmd_sf_destroy(struct sk_buff *skb, struct genl_info *info)
409 {
410 	struct nlattr *raddr = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
411 	struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
412 	struct nlattr *laddr = info->attrs[MPTCP_PM_ATTR_ADDR];
413 	struct mptcp_addr_info addr_l;
414 	struct mptcp_addr_info addr_r;
415 	struct mptcp_sock *msk;
416 	struct sock *sk, *ssk;
417 	int err = -EINVAL;
418 	u32 token_val;
419 
420 	if (!laddr || !raddr || !token) {
421 		GENL_SET_ERR_MSG(info, "missing required inputs");
422 		return err;
423 	}
424 
425 	token_val = nla_get_u32(token);
426 
427 	msk = mptcp_token_get_sock(genl_info_net(info), token_val);
428 	if (!msk) {
429 		NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
430 		return err;
431 	}
432 
433 	if (!mptcp_pm_is_userspace(msk)) {
434 		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
435 		goto destroy_err;
436 	}
437 
438 	err = mptcp_pm_parse_addr(laddr, info, &addr_l);
439 	if (err < 0) {
440 		NL_SET_ERR_MSG_ATTR(info->extack, laddr, "error parsing local addr");
441 		goto destroy_err;
442 	}
443 
444 	err = mptcp_pm_parse_addr(raddr, info, &addr_r);
445 	if (err < 0) {
446 		NL_SET_ERR_MSG_ATTR(info->extack, raddr, "error parsing remote addr");
447 		goto destroy_err;
448 	}
449 
450 	if (addr_l.family != addr_r.family) {
451 		GENL_SET_ERR_MSG(info, "address families do not match");
452 		err = -EINVAL;
453 		goto destroy_err;
454 	}
455 
456 	if (!addr_l.port || !addr_r.port) {
457 		GENL_SET_ERR_MSG(info, "missing local or remote port");
458 		err = -EINVAL;
459 		goto destroy_err;
460 	}
461 
462 	sk = (struct sock *)msk;
463 	lock_sock(sk);
464 	ssk = mptcp_nl_find_ssk(msk, &addr_l, &addr_r);
465 	if (ssk) {
466 		struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
467 		struct mptcp_pm_addr_entry entry = { .addr = addr_l };
468 
469 		spin_lock_bh(&msk->pm.lock);
470 		mptcp_userspace_pm_delete_local_addr(msk, &entry);
471 		spin_unlock_bh(&msk->pm.lock);
472 		mptcp_subflow_shutdown(sk, ssk, RCV_SHUTDOWN | SEND_SHUTDOWN);
473 		mptcp_close_ssk(sk, ssk, subflow);
474 		MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RMSUBFLOW);
475 		err = 0;
476 	} else {
477 		err = -ESRCH;
478 	}
479 	release_sock(sk);
480 
481 destroy_err:
482 	sock_put((struct sock *)msk);
483 	return err;
484 }
485 
486 int mptcp_userspace_pm_set_flags(struct net *net, struct nlattr *token,
487 				 struct mptcp_pm_addr_entry *loc,
488 				 struct mptcp_pm_addr_entry *rem, u8 bkup)
489 {
490 	struct mptcp_sock *msk;
491 	int ret = -EINVAL;
492 	u32 token_val;
493 
494 	token_val = nla_get_u32(token);
495 
496 	msk = mptcp_token_get_sock(net, token_val);
497 	if (!msk)
498 		return ret;
499 
500 	if (!mptcp_pm_is_userspace(msk))
501 		goto set_flags_err;
502 
503 	if (loc->addr.family == AF_UNSPEC ||
504 	    rem->addr.family == AF_UNSPEC)
505 		goto set_flags_err;
506 
507 	lock_sock((struct sock *)msk);
508 	ret = mptcp_pm_nl_mp_prio_send_ack(msk, &loc->addr, &rem->addr, bkup);
509 	release_sock((struct sock *)msk);
510 
511 set_flags_err:
512 	sock_put((struct sock *)msk);
513 	return ret;
514 }
515