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 			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 		ret = e->addr.id;
73 	} else if (match) {
74 		ret = entry->addr.id;
75 	}
76 
77 append_err:
78 	spin_unlock_bh(&msk->pm.lock);
79 	return ret;
80 }
81 
mptcp_userspace_pm_get_flags_and_ifindex_by_id(struct mptcp_sock * msk,unsigned int id,u8 * flags,int * ifindex)82 int mptcp_userspace_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk,
83 						   unsigned int id,
84 						   u8 *flags, int *ifindex)
85 {
86 	struct mptcp_pm_addr_entry *entry, *match = NULL;
87 
88 	*flags = 0;
89 	*ifindex = 0;
90 
91 	spin_lock_bh(&msk->pm.lock);
92 	list_for_each_entry(entry, &msk->pm.userspace_pm_local_addr_list, list) {
93 		if (id == entry->addr.id) {
94 			match = entry;
95 			break;
96 		}
97 	}
98 	spin_unlock_bh(&msk->pm.lock);
99 	if (match) {
100 		*flags = match->flags;
101 		*ifindex = match->ifindex;
102 	}
103 
104 	return 0;
105 }
106 
mptcp_userspace_pm_get_local_id(struct mptcp_sock * msk,struct mptcp_addr_info * skc)107 int mptcp_userspace_pm_get_local_id(struct mptcp_sock *msk,
108 				    struct mptcp_addr_info *skc)
109 {
110 	struct mptcp_pm_addr_entry new_entry;
111 	__be16 msk_sport =  ((struct inet_sock *)
112 			     inet_sk((struct sock *)msk))->inet_sport;
113 
114 	memset(&new_entry, 0, sizeof(struct mptcp_pm_addr_entry));
115 	new_entry.addr = *skc;
116 	new_entry.addr.id = 0;
117 	new_entry.flags = MPTCP_PM_ADDR_FLAG_IMPLICIT;
118 
119 	if (new_entry.addr.port == msk_sport)
120 		new_entry.addr.port = 0;
121 
122 	return mptcp_userspace_pm_append_new_local_addr(msk, &new_entry);
123 }
124 
mptcp_nl_cmd_announce(struct sk_buff * skb,struct genl_info * info)125 int mptcp_nl_cmd_announce(struct sk_buff *skb, struct genl_info *info)
126 {
127 	struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
128 	struct nlattr *addr = info->attrs[MPTCP_PM_ATTR_ADDR];
129 	struct mptcp_pm_addr_entry addr_val;
130 	struct mptcp_sock *msk;
131 	int err = -EINVAL;
132 	u32 token_val;
133 
134 	if (!addr || !token) {
135 		GENL_SET_ERR_MSG(info, "missing required inputs");
136 		return err;
137 	}
138 
139 	token_val = nla_get_u32(token);
140 
141 	msk = mptcp_token_get_sock(sock_net(skb->sk), token_val);
142 	if (!msk) {
143 		NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
144 		return err;
145 	}
146 
147 	if (!mptcp_pm_is_userspace(msk)) {
148 		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
149 		goto announce_err;
150 	}
151 
152 	err = mptcp_pm_parse_entry(addr, info, true, &addr_val);
153 	if (err < 0) {
154 		GENL_SET_ERR_MSG(info, "error parsing local address");
155 		goto announce_err;
156 	}
157 
158 	if (addr_val.addr.id == 0 || !(addr_val.flags & MPTCP_PM_ADDR_FLAG_SIGNAL)) {
159 		GENL_SET_ERR_MSG(info, "invalid addr id or flags");
160 		err = -EINVAL;
161 		goto announce_err;
162 	}
163 
164 	err = mptcp_userspace_pm_append_new_local_addr(msk, &addr_val);
165 	if (err < 0) {
166 		GENL_SET_ERR_MSG(info, "did not match address and id");
167 		goto announce_err;
168 	}
169 
170 	lock_sock((struct sock *)msk);
171 	spin_lock_bh(&msk->pm.lock);
172 
173 	if (mptcp_pm_alloc_anno_list(msk, &addr_val)) {
174 		mptcp_pm_announce_addr(msk, &addr_val.addr, false);
175 		mptcp_pm_nl_addr_send_ack(msk);
176 	}
177 
178 	spin_unlock_bh(&msk->pm.lock);
179 	release_sock((struct sock *)msk);
180 
181 	err = 0;
182  announce_err:
183 	sock_put((struct sock *)msk);
184 	return err;
185 }
186 
mptcp_nl_cmd_remove(struct sk_buff * skb,struct genl_info * info)187 int mptcp_nl_cmd_remove(struct sk_buff *skb, struct genl_info *info)
188 {
189 	struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
190 	struct nlattr *id = info->attrs[MPTCP_PM_ATTR_LOC_ID];
191 	struct mptcp_pm_addr_entry *match = NULL;
192 	struct mptcp_pm_addr_entry *entry;
193 	struct mptcp_sock *msk;
194 	LIST_HEAD(free_list);
195 	int err = -EINVAL;
196 	u32 token_val;
197 	u8 id_val;
198 
199 	if (!id || !token) {
200 		GENL_SET_ERR_MSG(info, "missing required inputs");
201 		return err;
202 	}
203 
204 	id_val = nla_get_u8(id);
205 	token_val = nla_get_u32(token);
206 
207 	msk = mptcp_token_get_sock(sock_net(skb->sk), token_val);
208 	if (!msk) {
209 		NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
210 		return err;
211 	}
212 
213 	if (!mptcp_pm_is_userspace(msk)) {
214 		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
215 		goto remove_err;
216 	}
217 
218 	lock_sock((struct sock *)msk);
219 
220 	list_for_each_entry(entry, &msk->pm.userspace_pm_local_addr_list, list) {
221 		if (entry->addr.id == id_val) {
222 			match = entry;
223 			break;
224 		}
225 	}
226 
227 	if (!match) {
228 		GENL_SET_ERR_MSG(info, "address with specified id not found");
229 		release_sock((struct sock *)msk);
230 		goto remove_err;
231 	}
232 
233 	list_move(&match->list, &free_list);
234 
235 	mptcp_pm_remove_addrs_and_subflows(msk, &free_list);
236 
237 	release_sock((struct sock *)msk);
238 
239 	list_for_each_entry_safe(match, entry, &free_list, list) {
240 		sock_kfree_s((struct sock *)msk, match, sizeof(*match));
241 	}
242 
243 	err = 0;
244  remove_err:
245 	sock_put((struct sock *)msk);
246 	return err;
247 }
248 
mptcp_nl_cmd_sf_create(struct sk_buff * skb,struct genl_info * info)249 int mptcp_nl_cmd_sf_create(struct sk_buff *skb, struct genl_info *info)
250 {
251 	struct nlattr *raddr = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
252 	struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
253 	struct nlattr *laddr = info->attrs[MPTCP_PM_ATTR_ADDR];
254 	struct mptcp_addr_info addr_r;
255 	struct mptcp_addr_info addr_l;
256 	struct mptcp_sock *msk;
257 	int err = -EINVAL;
258 	struct sock *sk;
259 	u32 token_val;
260 
261 	if (!laddr || !raddr || !token) {
262 		GENL_SET_ERR_MSG(info, "missing required inputs");
263 		return err;
264 	}
265 
266 	token_val = nla_get_u32(token);
267 
268 	msk = mptcp_token_get_sock(genl_info_net(info), token_val);
269 	if (!msk) {
270 		NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
271 		return err;
272 	}
273 
274 	if (!mptcp_pm_is_userspace(msk)) {
275 		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
276 		goto create_err;
277 	}
278 
279 	err = mptcp_pm_parse_addr(laddr, info, &addr_l);
280 	if (err < 0) {
281 		NL_SET_ERR_MSG_ATTR(info->extack, laddr, "error parsing local addr");
282 		goto create_err;
283 	}
284 
285 	if (addr_l.id == 0) {
286 		NL_SET_ERR_MSG_ATTR(info->extack, laddr, "missing local addr id");
287 		err = -EINVAL;
288 		goto create_err;
289 	}
290 
291 	err = mptcp_pm_parse_addr(raddr, info, &addr_r);
292 	if (err < 0) {
293 		NL_SET_ERR_MSG_ATTR(info->extack, raddr, "error parsing remote addr");
294 		goto create_err;
295 	}
296 
297 	sk = (struct sock *)msk;
298 
299 	if (!mptcp_pm_addr_families_match(sk, &addr_l, &addr_r)) {
300 		GENL_SET_ERR_MSG(info, "families mismatch");
301 		err = -EINVAL;
302 		goto create_err;
303 	}
304 
305 	lock_sock(sk);
306 
307 	err = __mptcp_subflow_connect(sk, &addr_l, &addr_r);
308 
309 	release_sock(sk);
310 
311  create_err:
312 	sock_put((struct sock *)msk);
313 	return err;
314 }
315 
mptcp_nl_find_ssk(struct mptcp_sock * msk,const struct mptcp_addr_info * local,const struct mptcp_addr_info * remote)316 static struct sock *mptcp_nl_find_ssk(struct mptcp_sock *msk,
317 				      const struct mptcp_addr_info *local,
318 				      const struct mptcp_addr_info *remote)
319 {
320 	struct mptcp_subflow_context *subflow;
321 
322 	if (local->family != remote->family)
323 		return NULL;
324 
325 	mptcp_for_each_subflow(msk, subflow) {
326 		const struct inet_sock *issk;
327 		struct sock *ssk;
328 
329 		ssk = mptcp_subflow_tcp_sock(subflow);
330 
331 		if (local->family != ssk->sk_family)
332 			continue;
333 
334 		issk = inet_sk(ssk);
335 
336 		switch (ssk->sk_family) {
337 		case AF_INET:
338 			if (issk->inet_saddr != local->addr.s_addr ||
339 			    issk->inet_daddr != remote->addr.s_addr)
340 				continue;
341 			break;
342 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
343 		case AF_INET6: {
344 			const struct ipv6_pinfo *pinfo = inet6_sk(ssk);
345 
346 			if (!ipv6_addr_equal(&local->addr6, &pinfo->saddr) ||
347 			    !ipv6_addr_equal(&remote->addr6, &ssk->sk_v6_daddr))
348 				continue;
349 			break;
350 		}
351 #endif
352 		default:
353 			continue;
354 		}
355 
356 		if (issk->inet_sport == local->port &&
357 		    issk->inet_dport == remote->port)
358 			return ssk;
359 	}
360 
361 	return NULL;
362 }
363 
mptcp_nl_cmd_sf_destroy(struct sk_buff * skb,struct genl_info * info)364 int mptcp_nl_cmd_sf_destroy(struct sk_buff *skb, struct genl_info *info)
365 {
366 	struct nlattr *raddr = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
367 	struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
368 	struct nlattr *laddr = info->attrs[MPTCP_PM_ATTR_ADDR];
369 	struct mptcp_addr_info addr_l;
370 	struct mptcp_addr_info addr_r;
371 	struct mptcp_sock *msk;
372 	struct sock *sk, *ssk;
373 	int err = -EINVAL;
374 	u32 token_val;
375 
376 	if (!laddr || !raddr || !token) {
377 		GENL_SET_ERR_MSG(info, "missing required inputs");
378 		return err;
379 	}
380 
381 	token_val = nla_get_u32(token);
382 
383 	msk = mptcp_token_get_sock(genl_info_net(info), token_val);
384 	if (!msk) {
385 		NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
386 		return err;
387 	}
388 
389 	if (!mptcp_pm_is_userspace(msk)) {
390 		GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
391 		goto destroy_err;
392 	}
393 
394 	err = mptcp_pm_parse_addr(laddr, info, &addr_l);
395 	if (err < 0) {
396 		NL_SET_ERR_MSG_ATTR(info->extack, laddr, "error parsing local addr");
397 		goto destroy_err;
398 	}
399 
400 	err = mptcp_pm_parse_addr(raddr, info, &addr_r);
401 	if (err < 0) {
402 		NL_SET_ERR_MSG_ATTR(info->extack, raddr, "error parsing remote addr");
403 		goto destroy_err;
404 	}
405 
406 	if (addr_l.family != addr_r.family) {
407 		GENL_SET_ERR_MSG(info, "address families do not match");
408 		err = -EINVAL;
409 		goto destroy_err;
410 	}
411 
412 	if (!addr_l.port || !addr_r.port) {
413 		GENL_SET_ERR_MSG(info, "missing local or remote port");
414 		err = -EINVAL;
415 		goto destroy_err;
416 	}
417 
418 	sk = (struct sock *)msk;
419 	lock_sock(sk);
420 	ssk = mptcp_nl_find_ssk(msk, &addr_l, &addr_r);
421 	if (ssk) {
422 		struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
423 
424 		mptcp_subflow_shutdown(sk, ssk, RCV_SHUTDOWN | SEND_SHUTDOWN);
425 		mptcp_close_ssk(sk, ssk, subflow);
426 		MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RMSUBFLOW);
427 		err = 0;
428 	} else {
429 		err = -ESRCH;
430 	}
431 	release_sock(sk);
432 
433 destroy_err:
434 	sock_put((struct sock *)msk);
435 	return err;
436 }
437 
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)438 int mptcp_userspace_pm_set_flags(struct net *net, struct nlattr *token,
439 				 struct mptcp_pm_addr_entry *loc,
440 				 struct mptcp_pm_addr_entry *rem, u8 bkup)
441 {
442 	struct mptcp_sock *msk;
443 	int ret = -EINVAL;
444 	u32 token_val;
445 
446 	token_val = nla_get_u32(token);
447 
448 	msk = mptcp_token_get_sock(net, token_val);
449 	if (!msk)
450 		return ret;
451 
452 	if (!mptcp_pm_is_userspace(msk))
453 		goto set_flags_err;
454 
455 	if (loc->addr.family == AF_UNSPEC ||
456 	    rem->addr.family == AF_UNSPEC)
457 		goto set_flags_err;
458 
459 	lock_sock((struct sock *)msk);
460 	ret = mptcp_pm_nl_mp_prio_send_ack(msk, &loc->addr, &rem->addr, bkup);
461 	release_sock((struct sock *)msk);
462 
463 set_flags_err:
464 	sock_put((struct sock *)msk);
465 	return ret;
466 }
467