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)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  */
mptcp_userspace_pm_delete_local_addr(struct mptcp_sock * msk,struct mptcp_pm_addr_entry * addr)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 
mptcp_userspace_pm_get_flags_and_ifindex_by_id(struct mptcp_sock * msk,unsigned int id,u8 * flags,int * ifindex)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 
mptcp_userspace_pm_get_local_id(struct mptcp_sock * msk,struct mptcp_addr_info * skc)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 new_entry;
134 	__be16 msk_sport =  ((struct inet_sock *)
135 			     inet_sk((struct sock *)msk))->inet_sport;
136 
137 	memset(&new_entry, 0, sizeof(struct mptcp_pm_addr_entry));
138 	new_entry.addr = *skc;
139 	new_entry.addr.id = 0;
140 	new_entry.flags = MPTCP_PM_ADDR_FLAG_IMPLICIT;
141 
142 	if (new_entry.addr.port == msk_sport)
143 		new_entry.addr.port = 0;
144 
145 	return mptcp_userspace_pm_append_new_local_addr(msk, &new_entry);
146 }
147 
mptcp_nl_cmd_announce(struct sk_buff * skb,struct genl_info * info)148 int mptcp_nl_cmd_announce(struct sk_buff *skb, struct genl_info *info)
149 {
150 	struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
151 	struct nlattr *addr = info->attrs[MPTCP_PM_ATTR_ADDR];
152 	struct mptcp_pm_addr_entry addr_val;
153 	struct mptcp_sock *msk;
154 	int err = -EINVAL;
155 	u32 token_val;
156 
157 	if (!addr || !token) {
158 		GENL_SET_ERR_MSG(info, "missing required inputs");
159 		return err;
160 	}
161 
162 	token_val = nla_get_u32(token);
163 
164 	msk = mptcp_token_get_sock(sock_net(skb->sk), token_val);
165 	if (!msk) {
166 		NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
167 		return err;
168 	}
169 
170 	if (!mptcp_pm_is_userspace(msk)) {
171 		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
172 		goto announce_err;
173 	}
174 
175 	err = mptcp_pm_parse_entry(addr, info, true, &addr_val);
176 	if (err < 0) {
177 		GENL_SET_ERR_MSG(info, "error parsing local address");
178 		goto announce_err;
179 	}
180 
181 	if (addr_val.addr.id == 0 || !(addr_val.flags & MPTCP_PM_ADDR_FLAG_SIGNAL)) {
182 		GENL_SET_ERR_MSG(info, "invalid addr id or flags");
183 		err = -EINVAL;
184 		goto announce_err;
185 	}
186 
187 	err = mptcp_userspace_pm_append_new_local_addr(msk, &addr_val);
188 	if (err < 0) {
189 		GENL_SET_ERR_MSG(info, "did not match address and id");
190 		goto announce_err;
191 	}
192 
193 	lock_sock((struct sock *)msk);
194 	spin_lock_bh(&msk->pm.lock);
195 
196 	if (mptcp_pm_alloc_anno_list(msk, &addr_val.addr)) {
197 		msk->pm.add_addr_signaled++;
198 		mptcp_pm_announce_addr(msk, &addr_val.addr, false);
199 		mptcp_pm_nl_addr_send_ack(msk);
200 	}
201 
202 	spin_unlock_bh(&msk->pm.lock);
203 	release_sock((struct sock *)msk);
204 
205 	err = 0;
206  announce_err:
207 	sock_put((struct sock *)msk);
208 	return err;
209 }
210 
mptcp_nl_cmd_remove(struct sk_buff * skb,struct genl_info * info)211 int mptcp_nl_cmd_remove(struct sk_buff *skb, struct genl_info *info)
212 {
213 	struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
214 	struct nlattr *id = info->attrs[MPTCP_PM_ATTR_LOC_ID];
215 	struct mptcp_pm_addr_entry *match = NULL;
216 	struct mptcp_pm_addr_entry *entry;
217 	struct mptcp_sock *msk;
218 	LIST_HEAD(free_list);
219 	int err = -EINVAL;
220 	u32 token_val;
221 	u8 id_val;
222 
223 	if (!id || !token) {
224 		GENL_SET_ERR_MSG(info, "missing required inputs");
225 		return err;
226 	}
227 
228 	id_val = nla_get_u8(id);
229 	token_val = nla_get_u32(token);
230 
231 	msk = mptcp_token_get_sock(sock_net(skb->sk), token_val);
232 	if (!msk) {
233 		NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
234 		return err;
235 	}
236 
237 	if (!mptcp_pm_is_userspace(msk)) {
238 		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
239 		goto remove_err;
240 	}
241 
242 	lock_sock((struct sock *)msk);
243 
244 	list_for_each_entry(entry, &msk->pm.userspace_pm_local_addr_list, list) {
245 		if (entry->addr.id == id_val) {
246 			match = entry;
247 			break;
248 		}
249 	}
250 
251 	if (!match) {
252 		GENL_SET_ERR_MSG(info, "address with specified id not found");
253 		release_sock((struct sock *)msk);
254 		goto remove_err;
255 	}
256 
257 	list_move(&match->list, &free_list);
258 
259 	mptcp_pm_remove_addrs(msk, &free_list);
260 
261 	release_sock((struct sock *)msk);
262 
263 	list_for_each_entry_safe(match, entry, &free_list, list) {
264 		sock_kfree_s((struct sock *)msk, match, sizeof(*match));
265 	}
266 
267 	err = 0;
268  remove_err:
269 	sock_put((struct sock *)msk);
270 	return err;
271 }
272 
mptcp_nl_cmd_sf_create(struct sk_buff * skb,struct genl_info * info)273 int mptcp_nl_cmd_sf_create(struct sk_buff *skb, struct genl_info *info)
274 {
275 	struct nlattr *raddr = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
276 	struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
277 	struct nlattr *laddr = info->attrs[MPTCP_PM_ATTR_ADDR];
278 	struct mptcp_pm_addr_entry local = { 0 };
279 	struct mptcp_addr_info addr_r;
280 	struct mptcp_addr_info addr_l;
281 	struct mptcp_sock *msk;
282 	int err = -EINVAL;
283 	struct sock *sk;
284 	u32 token_val;
285 
286 	if (!laddr || !raddr || !token) {
287 		GENL_SET_ERR_MSG(info, "missing required inputs");
288 		return err;
289 	}
290 
291 	token_val = nla_get_u32(token);
292 
293 	msk = mptcp_token_get_sock(genl_info_net(info), token_val);
294 	if (!msk) {
295 		NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
296 		return err;
297 	}
298 
299 	if (!mptcp_pm_is_userspace(msk)) {
300 		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
301 		goto create_err;
302 	}
303 
304 	err = mptcp_pm_parse_addr(laddr, info, &addr_l);
305 	if (err < 0) {
306 		NL_SET_ERR_MSG_ATTR(info->extack, laddr, "error parsing local addr");
307 		goto create_err;
308 	}
309 
310 	err = mptcp_pm_parse_addr(raddr, info, &addr_r);
311 	if (err < 0) {
312 		NL_SET_ERR_MSG_ATTR(info->extack, raddr, "error parsing remote addr");
313 		goto create_err;
314 	}
315 
316 	sk = (struct sock *)msk;
317 
318 	if (!mptcp_pm_addr_families_match(sk, &addr_l, &addr_r)) {
319 		GENL_SET_ERR_MSG(info, "families mismatch");
320 		err = -EINVAL;
321 		goto create_err;
322 	}
323 
324 	local.addr = addr_l;
325 	err = mptcp_userspace_pm_append_new_local_addr(msk, &local);
326 	if (err < 0) {
327 		GENL_SET_ERR_MSG(info, "did not match address and id");
328 		goto create_err;
329 	}
330 
331 	lock_sock(sk);
332 
333 	err = __mptcp_subflow_connect(sk, &addr_l, &addr_r);
334 
335 	release_sock(sk);
336 
337 	spin_lock_bh(&msk->pm.lock);
338 	if (err)
339 		mptcp_userspace_pm_delete_local_addr(msk, &local);
340 	else
341 		msk->pm.subflows++;
342 	spin_unlock_bh(&msk->pm.lock);
343 
344  create_err:
345 	sock_put((struct sock *)msk);
346 	return err;
347 }
348 
mptcp_nl_find_ssk(struct mptcp_sock * msk,const struct mptcp_addr_info * local,const struct mptcp_addr_info * remote)349 static struct sock *mptcp_nl_find_ssk(struct mptcp_sock *msk,
350 				      const struct mptcp_addr_info *local,
351 				      const struct mptcp_addr_info *remote)
352 {
353 	struct mptcp_subflow_context *subflow;
354 
355 	if (local->family != remote->family)
356 		return NULL;
357 
358 	mptcp_for_each_subflow(msk, subflow) {
359 		const struct inet_sock *issk;
360 		struct sock *ssk;
361 
362 		ssk = mptcp_subflow_tcp_sock(subflow);
363 
364 		if (local->family != ssk->sk_family)
365 			continue;
366 
367 		issk = inet_sk(ssk);
368 
369 		switch (ssk->sk_family) {
370 		case AF_INET:
371 			if (issk->inet_saddr != local->addr.s_addr ||
372 			    issk->inet_daddr != remote->addr.s_addr)
373 				continue;
374 			break;
375 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
376 		case AF_INET6: {
377 			const struct ipv6_pinfo *pinfo = inet6_sk(ssk);
378 
379 			if (!ipv6_addr_equal(&local->addr6, &pinfo->saddr) ||
380 			    !ipv6_addr_equal(&remote->addr6, &ssk->sk_v6_daddr))
381 				continue;
382 			break;
383 		}
384 #endif
385 		default:
386 			continue;
387 		}
388 
389 		if (issk->inet_sport == local->port &&
390 		    issk->inet_dport == remote->port)
391 			return ssk;
392 	}
393 
394 	return NULL;
395 }
396 
mptcp_nl_cmd_sf_destroy(struct sk_buff * skb,struct genl_info * info)397 int mptcp_nl_cmd_sf_destroy(struct sk_buff *skb, struct genl_info *info)
398 {
399 	struct nlattr *raddr = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
400 	struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
401 	struct nlattr *laddr = info->attrs[MPTCP_PM_ATTR_ADDR];
402 	struct mptcp_addr_info addr_l;
403 	struct mptcp_addr_info addr_r;
404 	struct mptcp_sock *msk;
405 	struct sock *sk, *ssk;
406 	int err = -EINVAL;
407 	u32 token_val;
408 
409 	if (!laddr || !raddr || !token) {
410 		GENL_SET_ERR_MSG(info, "missing required inputs");
411 		return err;
412 	}
413 
414 	token_val = nla_get_u32(token);
415 
416 	msk = mptcp_token_get_sock(genl_info_net(info), token_val);
417 	if (!msk) {
418 		NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
419 		return err;
420 	}
421 
422 	if (!mptcp_pm_is_userspace(msk)) {
423 		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
424 		goto destroy_err;
425 	}
426 
427 	err = mptcp_pm_parse_addr(laddr, info, &addr_l);
428 	if (err < 0) {
429 		NL_SET_ERR_MSG_ATTR(info->extack, laddr, "error parsing local addr");
430 		goto destroy_err;
431 	}
432 
433 	err = mptcp_pm_parse_addr(raddr, info, &addr_r);
434 	if (err < 0) {
435 		NL_SET_ERR_MSG_ATTR(info->extack, raddr, "error parsing remote addr");
436 		goto destroy_err;
437 	}
438 
439 	if (addr_l.family != addr_r.family) {
440 		GENL_SET_ERR_MSG(info, "address families do not match");
441 		err = -EINVAL;
442 		goto destroy_err;
443 	}
444 
445 	if (!addr_l.port || !addr_r.port) {
446 		GENL_SET_ERR_MSG(info, "missing local or remote port");
447 		err = -EINVAL;
448 		goto destroy_err;
449 	}
450 
451 	sk = (struct sock *)msk;
452 	lock_sock(sk);
453 	ssk = mptcp_nl_find_ssk(msk, &addr_l, &addr_r);
454 	if (ssk) {
455 		struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
456 		struct mptcp_pm_addr_entry entry = { .addr = addr_l };
457 
458 		spin_lock_bh(&msk->pm.lock);
459 		mptcp_userspace_pm_delete_local_addr(msk, &entry);
460 		spin_unlock_bh(&msk->pm.lock);
461 		mptcp_subflow_shutdown(sk, ssk, RCV_SHUTDOWN | SEND_SHUTDOWN);
462 		mptcp_close_ssk(sk, ssk, subflow);
463 		MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RMSUBFLOW);
464 		err = 0;
465 	} else {
466 		err = -ESRCH;
467 	}
468 	release_sock(sk);
469 
470 destroy_err:
471 	sock_put((struct sock *)msk);
472 	return err;
473 }
474 
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)475 int mptcp_userspace_pm_set_flags(struct net *net, struct nlattr *token,
476 				 struct mptcp_pm_addr_entry *loc,
477 				 struct mptcp_pm_addr_entry *rem, u8 bkup)
478 {
479 	struct mptcp_sock *msk;
480 	int ret = -EINVAL;
481 	u32 token_val;
482 
483 	token_val = nla_get_u32(token);
484 
485 	msk = mptcp_token_get_sock(net, token_val);
486 	if (!msk)
487 		return ret;
488 
489 	if (!mptcp_pm_is_userspace(msk))
490 		goto set_flags_err;
491 
492 	if (loc->addr.family == AF_UNSPEC ||
493 	    rem->addr.family == AF_UNSPEC)
494 		goto set_flags_err;
495 
496 	lock_sock((struct sock *)msk);
497 	ret = mptcp_pm_nl_mp_prio_send_ack(msk, &loc->addr, &rem->addr, bkup);
498 	release_sock((struct sock *)msk);
499 
500 set_flags_err:
501 	sock_put((struct sock *)msk);
502 	return ret;
503 }
504