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
 10void 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
 28static 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
 79append_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 */
 89static 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
109int 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
131int 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
160int mptcp_pm_nl_announce_doit(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	struct sock *sk;
168	u32 token_val;
169
170	if (!addr || !token) {
171		GENL_SET_ERR_MSG(info, "missing required inputs");
172		return err;
173	}
174
175	token_val = nla_get_u32(token);
176
177	msk = mptcp_token_get_sock(sock_net(skb->sk), token_val);
178	if (!msk) {
179		NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
180		return err;
181	}
182
183	sk = (struct sock *)msk;
184
185	if (!mptcp_pm_is_userspace(msk)) {
186		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
187		goto announce_err;
188	}
189
190	err = mptcp_pm_parse_entry(addr, info, true, &addr_val);
191	if (err < 0) {
192		GENL_SET_ERR_MSG(info, "error parsing local address");
193		goto announce_err;
194	}
195
196	if (addr_val.addr.id == 0 || !(addr_val.flags & MPTCP_PM_ADDR_FLAG_SIGNAL)) {
197		GENL_SET_ERR_MSG(info, "invalid addr id or flags");
198		err = -EINVAL;
199		goto announce_err;
200	}
201
202	err = mptcp_userspace_pm_append_new_local_addr(msk, &addr_val, false);
203	if (err < 0) {
204		GENL_SET_ERR_MSG(info, "did not match address and id");
205		goto announce_err;
206	}
207
208	lock_sock(sk);
209	spin_lock_bh(&msk->pm.lock);
210
211	if (mptcp_pm_alloc_anno_list(msk, &addr_val.addr)) {
212		msk->pm.add_addr_signaled++;
213		mptcp_pm_announce_addr(msk, &addr_val.addr, false);
214		mptcp_pm_nl_addr_send_ack(msk);
215	}
216
217	spin_unlock_bh(&msk->pm.lock);
218	release_sock(sk);
219
220	err = 0;
221 announce_err:
222	sock_put(sk);
223	return err;
224}
225
226static int mptcp_userspace_pm_remove_id_zero_address(struct mptcp_sock *msk,
227						     struct genl_info *info)
228{
229	struct mptcp_rm_list list = { .nr = 0 };
230	struct mptcp_subflow_context *subflow;
231	struct sock *sk = (struct sock *)msk;
232	bool has_id_0 = false;
233	int err = -EINVAL;
234
235	lock_sock(sk);
236	mptcp_for_each_subflow(msk, subflow) {
237		if (READ_ONCE(subflow->local_id) == 0) {
238			has_id_0 = true;
239			break;
240		}
241	}
242	if (!has_id_0) {
243		GENL_SET_ERR_MSG(info, "address with id 0 not found");
244		goto remove_err;
245	}
246
247	list.ids[list.nr++] = 0;
248
249	spin_lock_bh(&msk->pm.lock);
250	mptcp_pm_remove_addr(msk, &list);
251	spin_unlock_bh(&msk->pm.lock);
252
253	err = 0;
254
255remove_err:
256	release_sock(sk);
257	return err;
258}
259
260int mptcp_pm_nl_remove_doit(struct sk_buff *skb, struct genl_info *info)
261{
262	struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
263	struct nlattr *id = info->attrs[MPTCP_PM_ATTR_LOC_ID];
264	struct mptcp_pm_addr_entry *match = NULL;
265	struct mptcp_pm_addr_entry *entry;
266	struct mptcp_sock *msk;
267	LIST_HEAD(free_list);
268	int err = -EINVAL;
269	struct sock *sk;
270	u32 token_val;
271	u8 id_val;
272
273	if (!id || !token) {
274		GENL_SET_ERR_MSG(info, "missing required inputs");
275		return err;
276	}
277
278	id_val = nla_get_u8(id);
279	token_val = nla_get_u32(token);
280
281	msk = mptcp_token_get_sock(sock_net(skb->sk), token_val);
282	if (!msk) {
283		NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
284		return err;
285	}
286
287	sk = (struct sock *)msk;
288
289	if (!mptcp_pm_is_userspace(msk)) {
290		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
291		goto out;
292	}
293
294	if (id_val == 0) {
295		err = mptcp_userspace_pm_remove_id_zero_address(msk, info);
296		goto out;
297	}
298
299	lock_sock(sk);
300
301	list_for_each_entry(entry, &msk->pm.userspace_pm_local_addr_list, list) {
302		if (entry->addr.id == id_val) {
303			match = entry;
304			break;
305		}
306	}
307
308	if (!match) {
309		GENL_SET_ERR_MSG(info, "address with specified id not found");
310		release_sock(sk);
311		goto out;
312	}
313
314	list_move(&match->list, &free_list);
315
316	mptcp_pm_remove_addrs(msk, &free_list);
317
318	release_sock(sk);
319
320	list_for_each_entry_safe(match, entry, &free_list, list) {
321		sock_kfree_s(sk, match, sizeof(*match));
322	}
323
324	err = 0;
325out:
326	sock_put(sk);
327	return err;
328}
329
330int mptcp_pm_nl_subflow_create_doit(struct sk_buff *skb, struct genl_info *info)
331{
332	struct nlattr *raddr = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
333	struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
334	struct nlattr *laddr = info->attrs[MPTCP_PM_ATTR_ADDR];
335	struct mptcp_pm_addr_entry local = { 0 };
336	struct mptcp_addr_info addr_r;
337	struct mptcp_addr_info addr_l;
338	struct mptcp_sock *msk;
339	int err = -EINVAL;
340	struct sock *sk;
341	u32 token_val;
342
343	if (!laddr || !raddr || !token) {
344		GENL_SET_ERR_MSG(info, "missing required inputs");
345		return err;
346	}
347
348	token_val = nla_get_u32(token);
349
350	msk = mptcp_token_get_sock(genl_info_net(info), token_val);
351	if (!msk) {
352		NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
353		return err;
354	}
355
356	sk = (struct sock *)msk;
357
358	if (!mptcp_pm_is_userspace(msk)) {
359		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
360		goto create_err;
361	}
362
363	err = mptcp_pm_parse_addr(laddr, info, &addr_l);
364	if (err < 0) {
365		NL_SET_ERR_MSG_ATTR(info->extack, laddr, "error parsing local addr");
366		goto create_err;
367	}
368
369	err = mptcp_pm_parse_addr(raddr, info, &addr_r);
370	if (err < 0) {
371		NL_SET_ERR_MSG_ATTR(info->extack, raddr, "error parsing remote addr");
372		goto create_err;
373	}
374
375	if (!mptcp_pm_addr_families_match(sk, &addr_l, &addr_r)) {
376		GENL_SET_ERR_MSG(info, "families mismatch");
377		err = -EINVAL;
378		goto create_err;
379	}
380
381	local.addr = addr_l;
382	err = mptcp_userspace_pm_append_new_local_addr(msk, &local, false);
383	if (err < 0) {
384		GENL_SET_ERR_MSG(info, "did not match address and id");
385		goto create_err;
386	}
387
388	lock_sock(sk);
389
390	err = __mptcp_subflow_connect(sk, &addr_l, &addr_r);
391
392	release_sock(sk);
393
394	spin_lock_bh(&msk->pm.lock);
395	if (err)
396		mptcp_userspace_pm_delete_local_addr(msk, &local);
397	else
398		msk->pm.subflows++;
399	spin_unlock_bh(&msk->pm.lock);
400
401 create_err:
402	sock_put(sk);
403	return err;
404}
405
406static struct sock *mptcp_nl_find_ssk(struct mptcp_sock *msk,
407				      const struct mptcp_addr_info *local,
408				      const struct mptcp_addr_info *remote)
409{
410	struct mptcp_subflow_context *subflow;
411
412	if (local->family != remote->family)
413		return NULL;
414
415	mptcp_for_each_subflow(msk, subflow) {
416		const struct inet_sock *issk;
417		struct sock *ssk;
418
419		ssk = mptcp_subflow_tcp_sock(subflow);
420
421		if (local->family != ssk->sk_family)
422			continue;
423
424		issk = inet_sk(ssk);
425
426		switch (ssk->sk_family) {
427		case AF_INET:
428			if (issk->inet_saddr != local->addr.s_addr ||
429			    issk->inet_daddr != remote->addr.s_addr)
430				continue;
431			break;
432#if IS_ENABLED(CONFIG_MPTCP_IPV6)
433		case AF_INET6: {
434			const struct ipv6_pinfo *pinfo = inet6_sk(ssk);
435
436			if (!ipv6_addr_equal(&local->addr6, &pinfo->saddr) ||
437			    !ipv6_addr_equal(&remote->addr6, &ssk->sk_v6_daddr))
438				continue;
439			break;
440		}
441#endif
442		default:
443			continue;
444		}
445
446		if (issk->inet_sport == local->port &&
447		    issk->inet_dport == remote->port)
448			return ssk;
449	}
450
451	return NULL;
452}
453
454int mptcp_pm_nl_subflow_destroy_doit(struct sk_buff *skb, struct genl_info *info)
455{
456	struct nlattr *raddr = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
457	struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
458	struct nlattr *laddr = info->attrs[MPTCP_PM_ATTR_ADDR];
459	struct mptcp_addr_info addr_l;
460	struct mptcp_addr_info addr_r;
461	struct mptcp_sock *msk;
462	struct sock *sk, *ssk;
463	int err = -EINVAL;
464	u32 token_val;
465
466	if (!laddr || !raddr || !token) {
467		GENL_SET_ERR_MSG(info, "missing required inputs");
468		return err;
469	}
470
471	token_val = nla_get_u32(token);
472
473	msk = mptcp_token_get_sock(genl_info_net(info), token_val);
474	if (!msk) {
475		NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
476		return err;
477	}
478
479	sk = (struct sock *)msk;
480
481	if (!mptcp_pm_is_userspace(msk)) {
482		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
483		goto destroy_err;
484	}
485
486	err = mptcp_pm_parse_addr(laddr, info, &addr_l);
487	if (err < 0) {
488		NL_SET_ERR_MSG_ATTR(info->extack, laddr, "error parsing local addr");
489		goto destroy_err;
490	}
491
492	err = mptcp_pm_parse_addr(raddr, info, &addr_r);
493	if (err < 0) {
494		NL_SET_ERR_MSG_ATTR(info->extack, raddr, "error parsing remote addr");
495		goto destroy_err;
496	}
497
498#if IS_ENABLED(CONFIG_MPTCP_IPV6)
499	if (addr_l.family == AF_INET && ipv6_addr_v4mapped(&addr_r.addr6)) {
500		ipv6_addr_set_v4mapped(addr_l.addr.s_addr, &addr_l.addr6);
501		addr_l.family = AF_INET6;
502	}
503	if (addr_r.family == AF_INET && ipv6_addr_v4mapped(&addr_l.addr6)) {
504		ipv6_addr_set_v4mapped(addr_r.addr.s_addr, &addr_r.addr6);
505		addr_r.family = AF_INET6;
506	}
507#endif
508	if (addr_l.family != addr_r.family) {
509		GENL_SET_ERR_MSG(info, "address families do not match");
510		err = -EINVAL;
511		goto destroy_err;
512	}
513
514	if (!addr_l.port || !addr_r.port) {
515		GENL_SET_ERR_MSG(info, "missing local or remote port");
516		err = -EINVAL;
517		goto destroy_err;
518	}
519
520	lock_sock(sk);
521	ssk = mptcp_nl_find_ssk(msk, &addr_l, &addr_r);
522	if (ssk) {
523		struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
524		struct mptcp_pm_addr_entry entry = { .addr = addr_l };
525
526		spin_lock_bh(&msk->pm.lock);
527		mptcp_userspace_pm_delete_local_addr(msk, &entry);
528		spin_unlock_bh(&msk->pm.lock);
529		mptcp_subflow_shutdown(sk, ssk, RCV_SHUTDOWN | SEND_SHUTDOWN);
530		mptcp_close_ssk(sk, ssk, subflow);
531		MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RMSUBFLOW);
532		err = 0;
533	} else {
534		err = -ESRCH;
535	}
536	release_sock(sk);
537
538destroy_err:
539	sock_put(sk);
540	return err;
541}
542
543int mptcp_userspace_pm_set_flags(struct net *net, struct nlattr *token,
544				 struct mptcp_pm_addr_entry *loc,
545				 struct mptcp_pm_addr_entry *rem, u8 bkup)
546{
547	struct mptcp_sock *msk;
548	int ret = -EINVAL;
549	struct sock *sk;
550	u32 token_val;
551
552	token_val = nla_get_u32(token);
553
554	msk = mptcp_token_get_sock(net, token_val);
555	if (!msk)
556		return ret;
557
558	sk = (struct sock *)msk;
559
560	if (!mptcp_pm_is_userspace(msk))
561		goto set_flags_err;
562
563	if (loc->addr.family == AF_UNSPEC ||
564	    rem->addr.family == AF_UNSPEC)
565		goto set_flags_err;
566
567	lock_sock(sk);
568	ret = mptcp_pm_nl_mp_prio_send_ack(msk, &loc->addr, &rem->addr, bkup);
569	release_sock(sk);
570
571set_flags_err:
572	sock_put(sk);
573	return ret;
574}