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 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 			spin_unlock_bh(&msk->pm.lock);
63 			return -ENOMEM;
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 		ret = e->addr.id;
73 	} else if (match) {
74 		ret = entry->addr.id;
75 	}
76 
77 	spin_unlock_bh(&msk->pm.lock);
78 	return ret;
79 }
80 
mptcp_userspace_pm_get_flags_and_ifindex_by_id(struct mptcp_sock * msk,unsigned int id,u8 * flags,int * ifindex)81 int mptcp_userspace_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk,
82 						   unsigned int id,
83 						   u8 *flags, int *ifindex)
84 {
85 	struct mptcp_pm_addr_entry *entry, *match = NULL;
86 
87 	*flags = 0;
88 	*ifindex = 0;
89 
90 	spin_lock_bh(&msk->pm.lock);
91 	list_for_each_entry(entry, &msk->pm.userspace_pm_local_addr_list, list) {
92 		if (id == entry->addr.id) {
93 			match = entry;
94 			break;
95 		}
96 	}
97 	spin_unlock_bh(&msk->pm.lock);
98 	if (match) {
99 		*flags = match->flags;
100 		*ifindex = match->ifindex;
101 	}
102 
103 	return 0;
104 }
105 
mptcp_userspace_pm_get_local_id(struct mptcp_sock * msk,struct mptcp_addr_info * skc)106 int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk,
107 				    struct mptcp_addr_info *skc)
108 {
109 	struct mptcp_pm_addr_entry new_entry;
110 	__be16 msk_sport =  ((struct inet_sock *)
111 			     inet_sk((struct sock *)msk))->inet_sport;
112 
113 	memset(&new_entry, 0, sizeof(struct mptcp_pm_addr_entry));
114 	new_entry.addr = *skc;
115 	new_entry.addr.id = 0;
116 	new_entry.flags = MPTCP_PM_ADDR_FLAG_IMPLICIT;
117 
118 	if (new_entry.addr.port == msk_sport)
119 		new_entry.addr.port = 0;
120 
121 	return mptcp_userspace_pm_append_new_local_addr(msk, &new_entry);
122 }
123 
mptcp_nl_cmd_announce(struct sk_buff * skb,struct genl_info * info)124 int mptcp_nl_cmd_announce(struct sk_buff *skb, struct genl_info *info)
125 {
126 	struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
127 	struct nlattr *addr = info->attrs[MPTCP_PM_ATTR_ADDR];
128 	struct mptcp_pm_addr_entry addr_val;
129 	struct mptcp_sock *msk;
130 	int err = -EINVAL;
131 	u32 token_val;
132 
133 	if (!addr || !token) {
134 		GENL_SET_ERR_MSG(info, "missing required inputs");
135 		return err;
136 	}
137 
138 	token_val = nla_get_u32(token);
139 
140 	msk = mptcp_token_get_sock(sock_net(skb->sk), token_val);
141 	if (!msk) {
142 		NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
143 		return err;
144 	}
145 
146 	if (!mptcp_pm_is_userspace(msk)) {
147 		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
148 		goto announce_err;
149 	}
150 
151 	err = mptcp_pm_parse_entry(addr, info, true, &addr_val);
152 	if (err < 0) {
153 		GENL_SET_ERR_MSG(info, "error parsing local address");
154 		goto announce_err;
155 	}
156 
157 	if (addr_val.addr.id == 0 || !(addr_val.flags & MPTCP_PM_ADDR_FLAG_SIGNAL)) {
158 		GENL_SET_ERR_MSG(info, "invalid addr id or flags");
159 		err = -EINVAL;
160 		goto announce_err;
161 	}
162 
163 	err = mptcp_userspace_pm_append_new_local_addr(msk, &addr_val);
164 	if (err < 0) {
165 		GENL_SET_ERR_MSG(info, "did not match address and id");
166 		goto announce_err;
167 	}
168 
169 	lock_sock((struct sock *)msk);
170 	spin_lock_bh(&msk->pm.lock);
171 
172 	if (mptcp_pm_alloc_anno_list(msk, &addr_val)) {
173 		mptcp_pm_announce_addr(msk, &addr_val.addr, false);
174 		mptcp_pm_nl_addr_send_ack(msk);
175 	}
176 
177 	spin_unlock_bh(&msk->pm.lock);
178 	release_sock((struct sock *)msk);
179 
180 	err = 0;
181  announce_err:
182 	sock_put((struct sock *)msk);
183 	return err;
184 }
185 
mptcp_nl_cmd_remove(struct sk_buff * skb,struct genl_info * info)186 int mptcp_nl_cmd_remove(struct sk_buff *skb, struct genl_info *info)
187 {
188 	struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
189 	struct nlattr *id = info->attrs[MPTCP_PM_ATTR_LOC_ID];
190 	struct mptcp_pm_addr_entry *match = NULL;
191 	struct mptcp_pm_addr_entry *entry;
192 	struct mptcp_sock *msk;
193 	LIST_HEAD(free_list);
194 	int err = -EINVAL;
195 	u32 token_val;
196 	u8 id_val;
197 
198 	if (!id || !token) {
199 		GENL_SET_ERR_MSG(info, "missing required inputs");
200 		return err;
201 	}
202 
203 	id_val = nla_get_u8(id);
204 	token_val = nla_get_u32(token);
205 
206 	msk = mptcp_token_get_sock(sock_net(skb->sk), token_val);
207 	if (!msk) {
208 		NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
209 		return err;
210 	}
211 
212 	if (!mptcp_pm_is_userspace(msk)) {
213 		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
214 		goto remove_err;
215 	}
216 
217 	lock_sock((struct sock *)msk);
218 
219 	list_for_each_entry(entry, &msk->pm.userspace_pm_local_addr_list, list) {
220 		if (entry->addr.id == id_val) {
221 			match = entry;
222 			break;
223 		}
224 	}
225 
226 	if (!match) {
227 		GENL_SET_ERR_MSG(info, "address with specified id not found");
228 		release_sock((struct sock *)msk);
229 		goto remove_err;
230 	}
231 
232 	list_move(&match->list, &free_list);
233 
234 	mptcp_pm_remove_addrs_and_subflows(msk, &free_list);
235 
236 	release_sock((struct sock *)msk);
237 
238 	list_for_each_entry_safe(match, entry, &free_list, list) {
239 		sock_kfree_s((struct sock *)msk, match, sizeof(*match));
240 	}
241 
242 	err = 0;
243  remove_err:
244 	sock_put((struct sock *)msk);
245 	return err;
246 }
247 
mptcp_nl_cmd_sf_create(struct sk_buff * skb,struct genl_info * info)248 int mptcp_nl_cmd_sf_create(struct sk_buff *skb, struct genl_info *info)
249 {
250 	struct nlattr *raddr = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
251 	struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
252 	struct nlattr *laddr = info->attrs[MPTCP_PM_ATTR_ADDR];
253 	struct mptcp_addr_info addr_r;
254 	struct mptcp_addr_info addr_l;
255 	struct mptcp_sock *msk;
256 	int err = -EINVAL;
257 	struct sock *sk;
258 	u32 token_val;
259 
260 	if (!laddr || !raddr || !token) {
261 		GENL_SET_ERR_MSG(info, "missing required inputs");
262 		return err;
263 	}
264 
265 	token_val = nla_get_u32(token);
266 
267 	msk = mptcp_token_get_sock(genl_info_net(info), token_val);
268 	if (!msk) {
269 		NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
270 		return err;
271 	}
272 
273 	if (!mptcp_pm_is_userspace(msk)) {
274 		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
275 		goto create_err;
276 	}
277 
278 	err = mptcp_pm_parse_addr(laddr, info, &addr_l);
279 	if (err < 0) {
280 		NL_SET_ERR_MSG_ATTR(info->extack, laddr, "error parsing local addr");
281 		goto create_err;
282 	}
283 
284 	if (addr_l.id == 0) {
285 		NL_SET_ERR_MSG_ATTR(info->extack, laddr, "missing local addr id");
286 		err = -EINVAL;
287 		goto create_err;
288 	}
289 
290 	err = mptcp_pm_parse_addr(raddr, info, &addr_r);
291 	if (err < 0) {
292 		NL_SET_ERR_MSG_ATTR(info->extack, raddr, "error parsing remote addr");
293 		goto create_err;
294 	}
295 
296 	sk = &msk->sk.icsk_inet.sk;
297 
298 	if (!mptcp_pm_addr_families_match(sk, &addr_l, &addr_r)) {
299 		GENL_SET_ERR_MSG(info, "families mismatch");
300 		err = -EINVAL;
301 		goto create_err;
302 	}
303 
304 	lock_sock(sk);
305 
306 	err = __mptcp_subflow_connect(sk, &addr_l, &addr_r);
307 
308 	release_sock(sk);
309 
310  create_err:
311 	sock_put((struct sock *)msk);
312 	return err;
313 }
314 
mptcp_nl_find_ssk(struct mptcp_sock * msk,const struct mptcp_addr_info * local,const struct mptcp_addr_info * remote)315 static struct sock *mptcp_nl_find_ssk(struct mptcp_sock *msk,
316 				      const struct mptcp_addr_info *local,
317 				      const struct mptcp_addr_info *remote)
318 {
319 	struct mptcp_subflow_context *subflow;
320 
321 	if (local->family != remote->family)
322 		return NULL;
323 
324 	mptcp_for_each_subflow(msk, subflow) {
325 		const struct inet_sock *issk;
326 		struct sock *ssk;
327 
328 		ssk = mptcp_subflow_tcp_sock(subflow);
329 
330 		if (local->family != ssk->sk_family)
331 			continue;
332 
333 		issk = inet_sk(ssk);
334 
335 		switch (ssk->sk_family) {
336 		case AF_INET:
337 			if (issk->inet_saddr != local->addr.s_addr ||
338 			    issk->inet_daddr != remote->addr.s_addr)
339 				continue;
340 			break;
341 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
342 		case AF_INET6: {
343 			const struct ipv6_pinfo *pinfo = inet6_sk(ssk);
344 
345 			if (!ipv6_addr_equal(&local->addr6, &pinfo->saddr) ||
346 			    !ipv6_addr_equal(&remote->addr6, &ssk->sk_v6_daddr))
347 				continue;
348 			break;
349 		}
350 #endif
351 		default:
352 			continue;
353 		}
354 
355 		if (issk->inet_sport == local->port &&
356 		    issk->inet_dport == remote->port)
357 			return ssk;
358 	}
359 
360 	return NULL;
361 }
362 
mptcp_nl_cmd_sf_destroy(struct sk_buff * skb,struct genl_info * info)363 int mptcp_nl_cmd_sf_destroy(struct sk_buff *skb, struct genl_info *info)
364 {
365 	struct nlattr *raddr = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
366 	struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
367 	struct nlattr *laddr = info->attrs[MPTCP_PM_ATTR_ADDR];
368 	struct mptcp_addr_info addr_l;
369 	struct mptcp_addr_info addr_r;
370 	struct mptcp_sock *msk;
371 	struct sock *sk, *ssk;
372 	int err = -EINVAL;
373 	u32 token_val;
374 
375 	if (!laddr || !raddr || !token) {
376 		GENL_SET_ERR_MSG(info, "missing required inputs");
377 		return err;
378 	}
379 
380 	token_val = nla_get_u32(token);
381 
382 	msk = mptcp_token_get_sock(genl_info_net(info), token_val);
383 	if (!msk) {
384 		NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
385 		return err;
386 	}
387 
388 	if (!mptcp_pm_is_userspace(msk)) {
389 		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
390 		goto destroy_err;
391 	}
392 
393 	err = mptcp_pm_parse_addr(laddr, info, &addr_l);
394 	if (err < 0) {
395 		NL_SET_ERR_MSG_ATTR(info->extack, laddr, "error parsing local addr");
396 		goto destroy_err;
397 	}
398 
399 	err = mptcp_pm_parse_addr(raddr, info, &addr_r);
400 	if (err < 0) {
401 		NL_SET_ERR_MSG_ATTR(info->extack, raddr, "error parsing remote addr");
402 		goto destroy_err;
403 	}
404 
405 	if (addr_l.family != addr_r.family) {
406 		GENL_SET_ERR_MSG(info, "address families do not match");
407 		err = -EINVAL;
408 		goto destroy_err;
409 	}
410 
411 	if (!addr_l.port || !addr_r.port) {
412 		GENL_SET_ERR_MSG(info, "missing local or remote port");
413 		err = -EINVAL;
414 		goto destroy_err;
415 	}
416 
417 	sk = &msk->sk.icsk_inet.sk;
418 	lock_sock(sk);
419 	ssk = mptcp_nl_find_ssk(msk, &addr_l, &addr_r);
420 	if (ssk) {
421 		struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
422 
423 		mptcp_subflow_shutdown(sk, ssk, RCV_SHUTDOWN | SEND_SHUTDOWN);
424 		mptcp_close_ssk(sk, ssk, subflow);
425 		MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RMSUBFLOW);
426 		err = 0;
427 	} else {
428 		err = -ESRCH;
429 	}
430 	release_sock(sk);
431 
432 destroy_err:
433 	sock_put((struct sock *)msk);
434 	return err;
435 }
436 
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)437 int mptcp_userspace_pm_set_flags(struct net *net, struct nlattr *token,
438 				 struct mptcp_pm_addr_entry *loc,
439 				 struct mptcp_pm_addr_entry *rem, u8 bkup)
440 {
441 	struct mptcp_sock *msk;
442 	int ret = -EINVAL;
443 	u32 token_val;
444 
445 	token_val = nla_get_u32(token);
446 
447 	msk = mptcp_token_get_sock(net, token_val);
448 	if (!msk)
449 		return ret;
450 
451 	if (!mptcp_pm_is_userspace(msk))
452 		goto set_flags_err;
453 
454 	if (loc->addr.family == AF_UNSPEC ||
455 	    rem->addr.family == AF_UNSPEC)
456 		goto set_flags_err;
457 
458 	lock_sock((struct sock *)msk);
459 	ret = mptcp_pm_nl_mp_prio_send_ack(msk, &loc->addr, &rem->addr, bkup);
460 	release_sock((struct sock *)msk);
461 
462 set_flags_err:
463 	sock_put((struct sock *)msk);
464 	return ret;
465 }
466