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bus: mhi: core: Fix some error return code
[linux/fpc-iii.git] / net / mptcp / pm_netlink.c
blobb78edf237ba0ad6457f82758edf8623c913f9a4e
1 // SPDX-License-Identifier: GPL-2.0
2 /* Multipath TCP
3 *
4 * Copyright (c) 2020, Red Hat, Inc.
5 */
6
7 #define pr_fmt(fmt) "MPTCP: " fmt
8
9 #include <linux/inet.h>
10 #include <linux/kernel.h>
11 #include <net/tcp.h>
12 #include <net/netns/generic.h>
13 #include <net/mptcp.h>
14 #include <net/genetlink.h>
15 #include <uapi/linux/mptcp.h>
16
17 #include "protocol.h"
18
19 /* forward declaration */
20 static struct genl_family mptcp_genl_family;
21
22 static int pm_nl_pernet_id;
23
24 struct mptcp_pm_addr_entry {
25 struct list_head list;
26 unsigned int flags;
27 int ifindex;
28 struct mptcp_addr_info addr;
29 struct rcu_head rcu;
30 };
31
32 struct pm_nl_pernet {
33 /* protects pernet updates */
34 spinlock_t lock;
35 struct list_head local_addr_list;
36 unsigned int addrs;
37 unsigned int add_addr_signal_max;
38 unsigned int add_addr_accept_max;
39 unsigned int local_addr_max;
40 unsigned int subflows_max;
41 unsigned int next_id;
42 };
43
44 #define MPTCP_PM_ADDR_MAX 8
45
46 static bool addresses_equal(const struct mptcp_addr_info *a,
47 struct mptcp_addr_info *b, bool use_port)
48 {
49 bool addr_equals = false;
50
51 if (a->family != b->family)
52 return false;
53
54 if (a->family == AF_INET)
55 addr_equals = a->addr.s_addr == b->addr.s_addr;
56 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
57 else
58 addr_equals = !ipv6_addr_cmp(&a->addr6, &b->addr6);
59 #endif
60
61 if (!addr_equals)
62 return false;
63 if (!use_port)
64 return true;
65
66 return a->port == b->port;
67 }
68
69 static void local_address(const struct sock_common *skc,
70 struct mptcp_addr_info *addr)
71 {
72 addr->port = 0;
73 addr->family = skc->skc_family;
74 if (addr->family == AF_INET)
75 addr->addr.s_addr = skc->skc_rcv_saddr;
76 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
77 else if (addr->family == AF_INET6)
78 addr->addr6 = skc->skc_v6_rcv_saddr;
79 #endif
80 }
81
82 static void remote_address(const struct sock_common *skc,
83 struct mptcp_addr_info *addr)
84 {
85 addr->family = skc->skc_family;
86 addr->port = skc->skc_dport;
87 if (addr->family == AF_INET)
88 addr->addr.s_addr = skc->skc_daddr;
89 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
90 else if (addr->family == AF_INET6)
91 addr->addr6 = skc->skc_v6_daddr;
92 #endif
93 }
94
95 static bool lookup_subflow_by_saddr(const struct list_head *list,
96 struct mptcp_addr_info *saddr)
97 {
98 struct mptcp_subflow_context *subflow;
99 struct mptcp_addr_info cur;
100 struct sock_common *skc;
101
102 list_for_each_entry(subflow, list, node) {
103 skc = (struct sock_common *)mptcp_subflow_tcp_sock(subflow);
104
105 local_address(skc, &cur);
106 if (addresses_equal(&cur, saddr, false))
107 return true;
108 }
109
110 return false;
111 }
112
113 static struct mptcp_pm_addr_entry *
114 select_local_address(const struct pm_nl_pernet *pernet,
115 struct mptcp_sock *msk)
116 {
117 struct mptcp_pm_addr_entry *entry, *ret = NULL;
118
119 rcu_read_lock();
120 spin_lock_bh(&msk->join_list_lock);
121 list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
122 if (!(entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW))
123 continue;
124
125 /* avoid any address already in use by subflows and
126 * pending join
127 */
128 if (entry->addr.family == ((struct sock *)msk)->sk_family &&
129 !lookup_subflow_by_saddr(&msk->conn_list, &entry->addr) &&
130 !lookup_subflow_by_saddr(&msk->join_list, &entry->addr)) {
131 ret = entry;
132 break;
133 }
134 }
135 spin_unlock_bh(&msk->join_list_lock);
136 rcu_read_unlock();
137 return ret;
138 }
139
140 static struct mptcp_pm_addr_entry *
141 select_signal_address(struct pm_nl_pernet *pernet, unsigned int pos)
142 {
143 struct mptcp_pm_addr_entry *entry, *ret = NULL;
144 int i = 0;
145
146 rcu_read_lock();
147 /* do not keep any additional per socket state, just signal
148 * the address list in order.
149 * Note: removal from the local address list during the msk life-cycle
150 * can lead to additional addresses not being announced.
151 */
152 list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
153 if (!(entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL))
154 continue;
155 if (i++ == pos) {
156 ret = entry;
157 break;
158 }
159 }
160 rcu_read_unlock();
161 return ret;
162 }
163
164 static void check_work_pending(struct mptcp_sock *msk)
165 {
166 if (msk->pm.add_addr_signaled == msk->pm.add_addr_signal_max &&
167 (msk->pm.local_addr_used == msk->pm.local_addr_max ||
168 msk->pm.subflows == msk->pm.subflows_max))
169 WRITE_ONCE(msk->pm.work_pending, false);
170 }
171
172 static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk)
173 {
174 struct sock *sk = (struct sock *)msk;
175 struct mptcp_pm_addr_entry *local;
176 struct mptcp_addr_info remote;
177 struct pm_nl_pernet *pernet;
178
179 pernet = net_generic(sock_net((struct sock *)msk), pm_nl_pernet_id);
180
181 pr_debug("local %d:%d signal %d:%d subflows %d:%d\n",
182 msk->pm.local_addr_used, msk->pm.local_addr_max,
183 msk->pm.add_addr_signaled, msk->pm.add_addr_signal_max,
184 msk->pm.subflows, msk->pm.subflows_max);
185
186 /* check first for announce */
187 if (msk->pm.add_addr_signaled < msk->pm.add_addr_signal_max) {
188 local = select_signal_address(pernet,
189 msk->pm.add_addr_signaled);
190
191 if (local) {
192 msk->pm.add_addr_signaled++;
193 mptcp_pm_announce_addr(msk, &local->addr);
194 } else {
195 /* pick failed, avoid fourther attempts later */
196 msk->pm.local_addr_used = msk->pm.add_addr_signal_max;
197 }
198
199 check_work_pending(msk);
200 }
201
202 /* check if should create a new subflow */
203 if (msk->pm.local_addr_used < msk->pm.local_addr_max &&
204 msk->pm.subflows < msk->pm.subflows_max) {
205 remote_address((struct sock_common *)sk, &remote);
206
207 local = select_local_address(pernet, msk);
208 if (local) {
209 msk->pm.local_addr_used++;
210 msk->pm.subflows++;
211 check_work_pending(msk);
212 spin_unlock_bh(&msk->pm.lock);
213 __mptcp_subflow_connect(sk, local->ifindex,
214 &local->addr, &remote);
215 spin_lock_bh(&msk->pm.lock);
216 return;
217 }
218
219 /* lookup failed, avoid fourther attempts later */
220 msk->pm.local_addr_used = msk->pm.local_addr_max;
221 check_work_pending(msk);
222 }
223 }
224
225 void mptcp_pm_nl_fully_established(struct mptcp_sock *msk)
226 {
227 mptcp_pm_create_subflow_or_signal_addr(msk);
228 }
229
230 void mptcp_pm_nl_subflow_established(struct mptcp_sock *msk)
231 {
232 mptcp_pm_create_subflow_or_signal_addr(msk);
233 }
234
235 void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk)
236 {
237 struct sock *sk = (struct sock *)msk;
238 struct mptcp_addr_info remote;
239 struct mptcp_addr_info local;
240
241 pr_debug("accepted %d:%d remote family %d",
242 msk->pm.add_addr_accepted, msk->pm.add_addr_accept_max,
243 msk->pm.remote.family);
244 msk->pm.add_addr_accepted++;
245 msk->pm.subflows++;
246 if (msk->pm.add_addr_accepted >= msk->pm.add_addr_accept_max ||
247 msk->pm.subflows >= msk->pm.subflows_max)
248 WRITE_ONCE(msk->pm.accept_addr, false);
249
250 /* connect to the specified remote address, using whatever
251 * local address the routing configuration will pick.
252 */
253 remote = msk->pm.remote;
254 if (!remote.port)
255 remote.port = sk->sk_dport;
256 memset(&local, 0, sizeof(local));
257 local.family = remote.family;
258
259 spin_unlock_bh(&msk->pm.lock);
260 __mptcp_subflow_connect((struct sock *)msk, 0, &local, &remote);
261 spin_lock_bh(&msk->pm.lock);
262 }
263
264 static bool address_use_port(struct mptcp_pm_addr_entry *entry)
265 {
266 return (entry->flags &
267 (MPTCP_PM_ADDR_FLAG_SIGNAL | MPTCP_PM_ADDR_FLAG_SUBFLOW)) ==
268 MPTCP_PM_ADDR_FLAG_SIGNAL;
269 }
270
271 static int mptcp_pm_nl_append_new_local_addr(struct pm_nl_pernet *pernet,
272 struct mptcp_pm_addr_entry *entry)
273 {
274 struct mptcp_pm_addr_entry *cur;
275 int ret = -EINVAL;
276
277 spin_lock_bh(&pernet->lock);
278 /* to keep the code simple, don't do IDR-like allocation for address ID,
279 * just bail when we exceed limits
280 */
281 if (pernet->next_id > 255)
282 goto out;
283 if (pernet->addrs >= MPTCP_PM_ADDR_MAX)
284 goto out;
285
286 /* do not insert duplicate address, differentiate on port only
287 * singled addresses
288 */
289 list_for_each_entry(cur, &pernet->local_addr_list, list) {
290 if (addresses_equal(&cur->addr, &entry->addr,
291 address_use_port(entry) &&
292 address_use_port(cur)))
293 goto out;
294 }
295
296 if (entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL)
297 pernet->add_addr_signal_max++;
298 if (entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW)
299 pernet->local_addr_max++;
300
301 entry->addr.id = pernet->next_id++;
302 pernet->addrs++;
303 list_add_tail_rcu(&entry->list, &pernet->local_addr_list);
304 ret = entry->addr.id;
305
306 out:
307 spin_unlock_bh(&pernet->lock);
308 return ret;
309 }
310
311 int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct sock_common *skc)
312 {
313 struct mptcp_pm_addr_entry *entry;
314 struct mptcp_addr_info skc_local;
315 struct mptcp_addr_info msk_local;
316 struct pm_nl_pernet *pernet;
317 int ret = -1;
318
319 if (WARN_ON_ONCE(!msk))
320 return -1;
321
322 /* The 0 ID mapping is defined by the first subflow, copied into the msk
323 * addr
324 */
325 local_address((struct sock_common *)msk, &msk_local);
326 local_address((struct sock_common *)msk, &skc_local);
327 if (addresses_equal(&msk_local, &skc_local, false))
328 return 0;
329
330 pernet = net_generic(sock_net((struct sock *)msk), pm_nl_pernet_id);
331
332 rcu_read_lock();
333 list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
334 if (addresses_equal(&entry->addr, &skc_local, false)) {
335 ret = entry->addr.id;
336 break;
337 }
338 }
339 rcu_read_unlock();
340 if (ret >= 0)
341 return ret;
342
343 /* address not found, add to local list */
344 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
345 if (!entry)
346 return -ENOMEM;
347
348 entry->flags = 0;
349 entry->addr = skc_local;
350 ret = mptcp_pm_nl_append_new_local_addr(pernet, entry);
351 if (ret < 0)
352 kfree(entry);
353
354 return ret;
355 }
356
357 void mptcp_pm_nl_data_init(struct mptcp_sock *msk)
358 {
359 struct mptcp_pm_data *pm = &msk->pm;
360 struct pm_nl_pernet *pernet;
361 bool subflows;
362
363 pernet = net_generic(sock_net((struct sock *)msk), pm_nl_pernet_id);
364
365 pm->add_addr_signal_max = READ_ONCE(pernet->add_addr_signal_max);
366 pm->add_addr_accept_max = READ_ONCE(pernet->add_addr_accept_max);
367 pm->local_addr_max = READ_ONCE(pernet->local_addr_max);
368 pm->subflows_max = READ_ONCE(pernet->subflows_max);
369 subflows = !!pm->subflows_max;
370 WRITE_ONCE(pm->work_pending, (!!pm->local_addr_max && subflows) ||
371 !!pm->add_addr_signal_max);
372 WRITE_ONCE(pm->accept_addr, !!pm->add_addr_accept_max && subflows);
373 WRITE_ONCE(pm->accept_subflow, subflows);
374 }
375
376 #define MPTCP_PM_CMD_GRP_OFFSET 0
377
378 static const struct genl_multicast_group mptcp_pm_mcgrps[] = {
379 [MPTCP_PM_CMD_GRP_OFFSET] = { .name = MPTCP_PM_CMD_GRP_NAME, },
380 };
381
382 static const struct nla_policy
383 mptcp_pm_addr_policy[MPTCP_PM_ADDR_ATTR_MAX + 1] = {
384 [MPTCP_PM_ADDR_ATTR_FAMILY] = { .type = NLA_U16, },
385 [MPTCP_PM_ADDR_ATTR_ID] = { .type = NLA_U8, },
386 [MPTCP_PM_ADDR_ATTR_ADDR4] = { .type = NLA_U32, },
387 [MPTCP_PM_ADDR_ATTR_ADDR6] = { .type = NLA_EXACT_LEN,
388 .len = sizeof(struct in6_addr), },
389 [MPTCP_PM_ADDR_ATTR_PORT] = { .type = NLA_U16 },
390 [MPTCP_PM_ADDR_ATTR_FLAGS] = { .type = NLA_U32 },
391 [MPTCP_PM_ADDR_ATTR_IF_IDX] = { .type = NLA_S32 },
392 };
393
394 static const struct nla_policy mptcp_pm_policy[MPTCP_PM_ATTR_MAX + 1] = {
395 [MPTCP_PM_ATTR_ADDR] =
396 NLA_POLICY_NESTED(mptcp_pm_addr_policy),
397 [MPTCP_PM_ATTR_RCV_ADD_ADDRS] = { .type = NLA_U32, },
398 [MPTCP_PM_ATTR_SUBFLOWS] = { .type = NLA_U32, },
399 };
400
401 static int mptcp_pm_family_to_addr(int family)
402 {
403 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
404 if (family == AF_INET6)
405 return MPTCP_PM_ADDR_ATTR_ADDR6;
406 #endif
407 return MPTCP_PM_ADDR_ATTR_ADDR4;
408 }
409
410 static int mptcp_pm_parse_addr(struct nlattr *attr, struct genl_info *info,
411 bool require_family,
412 struct mptcp_pm_addr_entry *entry)
413 {
414 struct nlattr *tb[MPTCP_PM_ADDR_ATTR_MAX + 1];
415 int err, addr_addr;
416
417 if (!attr) {
418 GENL_SET_ERR_MSG(info, "missing address info");
419 return -EINVAL;
420 }
421
422 /* no validation needed - was already done via nested policy */
423 err = nla_parse_nested_deprecated(tb, MPTCP_PM_ADDR_ATTR_MAX, attr,
424 mptcp_pm_addr_policy, info->extack);
425 if (err)
426 return err;
427
428 memset(entry, 0, sizeof(*entry));
429 if (!tb[MPTCP_PM_ADDR_ATTR_FAMILY]) {
430 if (!require_family)
431 goto skip_family;
432
433 NL_SET_ERR_MSG_ATTR(info->extack, attr,
434 "missing family");
435 return -EINVAL;
436 }
437
438 entry->addr.family = nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_FAMILY]);
439 if (entry->addr.family != AF_INET
440 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
441 && entry->addr.family != AF_INET6
442 #endif
443 ) {
444 NL_SET_ERR_MSG_ATTR(info->extack, attr,
445 "unknown address family");
446 return -EINVAL;
447 }
448 addr_addr = mptcp_pm_family_to_addr(entry->addr.family);
449 if (!tb[addr_addr]) {
450 NL_SET_ERR_MSG_ATTR(info->extack, attr,
451 "missing address data");
452 return -EINVAL;
453 }
454
455 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
456 if (entry->addr.family == AF_INET6)
457 entry->addr.addr6 = nla_get_in6_addr(tb[addr_addr]);
458 else
459 #endif
460 entry->addr.addr.s_addr = nla_get_in_addr(tb[addr_addr]);
461
462 skip_family:
463 if (tb[MPTCP_PM_ADDR_ATTR_IF_IDX])
464 entry->ifindex = nla_get_s32(tb[MPTCP_PM_ADDR_ATTR_IF_IDX]);
465
466 if (tb[MPTCP_PM_ADDR_ATTR_ID])
467 entry->addr.id = nla_get_u8(tb[MPTCP_PM_ADDR_ATTR_ID]);
468
469 if (tb[MPTCP_PM_ADDR_ATTR_FLAGS])
470 entry->flags = nla_get_u32(tb[MPTCP_PM_ADDR_ATTR_FLAGS]);
471
472 return 0;
473 }
474
475 static struct pm_nl_pernet *genl_info_pm_nl(struct genl_info *info)
476 {
477 return net_generic(genl_info_net(info), pm_nl_pernet_id);
478 }
479
480 static int mptcp_nl_cmd_add_addr(struct sk_buff *skb, struct genl_info *info)
481 {
482 struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
483 struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
484 struct mptcp_pm_addr_entry addr, *entry;
485 int ret;
486
487 ret = mptcp_pm_parse_addr(attr, info, true, &addr);
488 if (ret < 0)
489 return ret;
490
491 entry = kmalloc(sizeof(*entry), GFP_KERNEL);
492 if (!entry) {
493 GENL_SET_ERR_MSG(info, "can't allocate addr");
494 return -ENOMEM;
495 }
496
497 *entry = addr;
498 ret = mptcp_pm_nl_append_new_local_addr(pernet, entry);
499 if (ret < 0) {
500 GENL_SET_ERR_MSG(info, "too many addresses or duplicate one");
501 kfree(entry);
502 return ret;
503 }
504
505 return 0;
506 }
507
508 static struct mptcp_pm_addr_entry *
509 __lookup_addr_by_id(struct pm_nl_pernet *pernet, unsigned int id)
510 {
511 struct mptcp_pm_addr_entry *entry;
512
513 list_for_each_entry(entry, &pernet->local_addr_list, list) {
514 if (entry->addr.id == id)
515 return entry;
516 }
517 return NULL;
518 }
519
520 static int mptcp_nl_cmd_del_addr(struct sk_buff *skb, struct genl_info *info)
521 {
522 struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
523 struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
524 struct mptcp_pm_addr_entry addr, *entry;
525 int ret;
526
527 ret = mptcp_pm_parse_addr(attr, info, false, &addr);
528 if (ret < 0)
529 return ret;
530
531 spin_lock_bh(&pernet->lock);
532 entry = __lookup_addr_by_id(pernet, addr.addr.id);
533 if (!entry) {
534 GENL_SET_ERR_MSG(info, "address not found");
535 ret = -EINVAL;
536 goto out;
537 }
538 if (entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL)
539 pernet->add_addr_signal_max--;
540 if (entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW)
541 pernet->local_addr_max--;
542
543 pernet->addrs--;
544 list_del_rcu(&entry->list);
545 kfree_rcu(entry, rcu);
546 out:
547 spin_unlock_bh(&pernet->lock);
548 return ret;
549 }
550
551 static void __flush_addrs(struct pm_nl_pernet *pernet)
552 {
553 while (!list_empty(&pernet->local_addr_list)) {
554 struct mptcp_pm_addr_entry *cur;
555
556 cur = list_entry(pernet->local_addr_list.next,
557 struct mptcp_pm_addr_entry, list);
558 list_del_rcu(&cur->list);
559 kfree_rcu(cur, rcu);
560 }
561 }
562
563 static void __reset_counters(struct pm_nl_pernet *pernet)
564 {
565 pernet->add_addr_signal_max = 0;
566 pernet->add_addr_accept_max = 0;
567 pernet->local_addr_max = 0;
568 pernet->addrs = 0;
569 }
570
571 static int mptcp_nl_cmd_flush_addrs(struct sk_buff *skb, struct genl_info *info)
572 {
573 struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
574
575 spin_lock_bh(&pernet->lock);
576 __flush_addrs(pernet);
577 __reset_counters(pernet);
578 spin_unlock_bh(&pernet->lock);
579 return 0;
580 }
581
582 static int mptcp_nl_fill_addr(struct sk_buff *skb,
583 struct mptcp_pm_addr_entry *entry)
584 {
585 struct mptcp_addr_info *addr = &entry->addr;
586 struct nlattr *attr;
587
588 attr = nla_nest_start(skb, MPTCP_PM_ATTR_ADDR);
589 if (!attr)
590 return -EMSGSIZE;
591
592 if (nla_put_u16(skb, MPTCP_PM_ADDR_ATTR_FAMILY, addr->family))
593 goto nla_put_failure;
594 if (nla_put_u8(skb, MPTCP_PM_ADDR_ATTR_ID, addr->id))
595 goto nla_put_failure;
596 if (nla_put_u32(skb, MPTCP_PM_ADDR_ATTR_FLAGS, entry->flags))
597 goto nla_put_failure;
598 if (entry->ifindex &&
599 nla_put_s32(skb, MPTCP_PM_ADDR_ATTR_IF_IDX, entry->ifindex))
600 goto nla_put_failure;
601
602 if (addr->family == AF_INET &&
603 nla_put_in_addr(skb, MPTCP_PM_ADDR_ATTR_ADDR4,
604 addr->addr.s_addr))
605 goto nla_put_failure;
606 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
607 else if (addr->family == AF_INET6 &&
608 nla_put_in6_addr(skb, MPTCP_PM_ADDR_ATTR_ADDR6, &addr->addr6))
609 goto nla_put_failure;
610 #endif
611 nla_nest_end(skb, attr);
612 return 0;
613
614 nla_put_failure:
615 nla_nest_cancel(skb, attr);
616 return -EMSGSIZE;
617 }
618
619 static int mptcp_nl_cmd_get_addr(struct sk_buff *skb, struct genl_info *info)
620 {
621 struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
622 struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
623 struct mptcp_pm_addr_entry addr, *entry;
624 struct sk_buff *msg;
625 void *reply;
626 int ret;
627
628 ret = mptcp_pm_parse_addr(attr, info, false, &addr);
629 if (ret < 0)
630 return ret;
631
632 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
633 if (!msg)
634 return -ENOMEM;
635
636 reply = genlmsg_put_reply(msg, info, &mptcp_genl_family, 0,
637 info->genlhdr->cmd);
638 if (!reply) {
639 GENL_SET_ERR_MSG(info, "not enough space in Netlink message");
640 ret = -EMSGSIZE;
641 goto fail;
642 }
643
644 spin_lock_bh(&pernet->lock);
645 entry = __lookup_addr_by_id(pernet, addr.addr.id);
646 if (!entry) {
647 GENL_SET_ERR_MSG(info, "address not found");
648 ret = -EINVAL;
649 goto unlock_fail;
650 }
651
652 ret = mptcp_nl_fill_addr(msg, entry);
653 if (ret)
654 goto unlock_fail;
655
656 genlmsg_end(msg, reply);
657 ret = genlmsg_reply(msg, info);
658 spin_unlock_bh(&pernet->lock);
659 return ret;
660
661 unlock_fail:
662 spin_unlock_bh(&pernet->lock);
663
664 fail:
665 nlmsg_free(msg);
666 return ret;
667 }
668
669 static int mptcp_nl_cmd_dump_addrs(struct sk_buff *msg,
670 struct netlink_callback *cb)
671 {
672 struct net *net = sock_net(msg->sk);
673 struct mptcp_pm_addr_entry *entry;
674 struct pm_nl_pernet *pernet;
675 int id = cb->args[0];
676 void *hdr;
677
678 pernet = net_generic(net, pm_nl_pernet_id);
679
680 spin_lock_bh(&pernet->lock);
681 list_for_each_entry(entry, &pernet->local_addr_list, list) {
682 if (entry->addr.id <= id)
683 continue;
684
685 hdr = genlmsg_put(msg, NETLINK_CB(cb->skb).portid,
686 cb->nlh->nlmsg_seq, &mptcp_genl_family,
687 NLM_F_MULTI, MPTCP_PM_CMD_GET_ADDR);
688 if (!hdr)
689 break;
690
691 if (mptcp_nl_fill_addr(msg, entry) < 0) {
692 genlmsg_cancel(msg, hdr);
693 break;
694 }
695
696 id = entry->addr.id;
697 genlmsg_end(msg, hdr);
698 }
699 spin_unlock_bh(&pernet->lock);
700
701 cb->args[0] = id;
702 return msg->len;
703 }
704
705 static int parse_limit(struct genl_info *info, int id, unsigned int *limit)
706 {
707 struct nlattr *attr = info->attrs[id];
708
709 if (!attr)
710 return 0;
711
712 *limit = nla_get_u32(attr);
713 if (*limit > MPTCP_PM_ADDR_MAX) {
714 GENL_SET_ERR_MSG(info, "limit greater than maximum");
715 return -EINVAL;
716 }
717 return 0;
718 }
719
720 static int
721 mptcp_nl_cmd_set_limits(struct sk_buff *skb, struct genl_info *info)
722 {
723 struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
724 unsigned int rcv_addrs, subflows;
725 int ret;
726
727 spin_lock_bh(&pernet->lock);
728 rcv_addrs = pernet->add_addr_accept_max;
729 ret = parse_limit(info, MPTCP_PM_ATTR_RCV_ADD_ADDRS, &rcv_addrs);
730 if (ret)
731 goto unlock;
732
733 subflows = pernet->subflows_max;
734 ret = parse_limit(info, MPTCP_PM_ATTR_SUBFLOWS, &subflows);
735 if (ret)
736 goto unlock;
737
738 WRITE_ONCE(pernet->add_addr_accept_max, rcv_addrs);
739 WRITE_ONCE(pernet->subflows_max, subflows);
740
741 unlock:
742 spin_unlock_bh(&pernet->lock);
743 return ret;
744 }
745
746 static int
747 mptcp_nl_cmd_get_limits(struct sk_buff *skb, struct genl_info *info)
748 {
749 struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
750 struct sk_buff *msg;
751 void *reply;
752
753 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
754 if (!msg)
755 return -ENOMEM;
756
757 reply = genlmsg_put_reply(msg, info, &mptcp_genl_family, 0,
758 MPTCP_PM_CMD_GET_LIMITS);
759 if (!reply)
760 goto fail;
761
762 if (nla_put_u32(msg, MPTCP_PM_ATTR_RCV_ADD_ADDRS,
763 READ_ONCE(pernet->add_addr_accept_max)))
764 goto fail;
765
766 if (nla_put_u32(msg, MPTCP_PM_ATTR_SUBFLOWS,
767 READ_ONCE(pernet->subflows_max)))
768 goto fail;
769
770 genlmsg_end(msg, reply);
771 return genlmsg_reply(msg, info);
772
773 fail:
774 GENL_SET_ERR_MSG(info, "not enough space in Netlink message");
775 nlmsg_free(msg);
776 return -EMSGSIZE;
777 }
778
779 static struct genl_ops mptcp_pm_ops[] = {
780 {
781 .cmd = MPTCP_PM_CMD_ADD_ADDR,
782 .doit = mptcp_nl_cmd_add_addr,
783 .flags = GENL_ADMIN_PERM,
784 },
785 {
786 .cmd = MPTCP_PM_CMD_DEL_ADDR,
787 .doit = mptcp_nl_cmd_del_addr,
788 .flags = GENL_ADMIN_PERM,
789 },
790 {
791 .cmd = MPTCP_PM_CMD_FLUSH_ADDRS,
792 .doit = mptcp_nl_cmd_flush_addrs,
793 .flags = GENL_ADMIN_PERM,
794 },
795 {
796 .cmd = MPTCP_PM_CMD_GET_ADDR,
797 .doit = mptcp_nl_cmd_get_addr,
798 .dumpit = mptcp_nl_cmd_dump_addrs,
799 },
800 {
801 .cmd = MPTCP_PM_CMD_SET_LIMITS,
802 .doit = mptcp_nl_cmd_set_limits,
803 .flags = GENL_ADMIN_PERM,
804 },
805 {
806 .cmd = MPTCP_PM_CMD_GET_LIMITS,
807 .doit = mptcp_nl_cmd_get_limits,
808 },
809 };
810
811 static struct genl_family mptcp_genl_family __ro_after_init = {
812 .name = MPTCP_PM_NAME,
813 .version = MPTCP_PM_VER,
814 .maxattr = MPTCP_PM_ATTR_MAX,
815 .policy = mptcp_pm_policy,
816 .netnsok = true,
817 .module = THIS_MODULE,
818 .ops = mptcp_pm_ops,
819 .n_ops = ARRAY_SIZE(mptcp_pm_ops),
820 .mcgrps = mptcp_pm_mcgrps,
821 .n_mcgrps = ARRAY_SIZE(mptcp_pm_mcgrps),
822 };
823
824 static int __net_init pm_nl_init_net(struct net *net)
825 {
826 struct pm_nl_pernet *pernet = net_generic(net, pm_nl_pernet_id);
827
828 INIT_LIST_HEAD_RCU(&pernet->local_addr_list);
829 __reset_counters(pernet);
830 pernet->next_id = 1;
831 spin_lock_init(&pernet->lock);
832 return 0;
833 }
834
835 static void __net_exit pm_nl_exit_net(struct list_head *net_list)
836 {
837 struct net *net;
838
839 list_for_each_entry(net, net_list, exit_list) {
840 /* net is removed from namespace list, can't race with
841 * other modifiers
842 */
843 __flush_addrs(net_generic(net, pm_nl_pernet_id));
844 }
845 }
846
847 static struct pernet_operations mptcp_pm_pernet_ops = {
848 .init = pm_nl_init_net,
849 .exit_batch = pm_nl_exit_net,
850 .id = &pm_nl_pernet_id,
851 .size = sizeof(struct pm_nl_pernet),
852 };
853
854 void mptcp_pm_nl_init(void)
855 {
856 if (register_pernet_subsys(&mptcp_pm_pernet_ops) < 0)
857 panic("Failed to register MPTCP PM pernet subsystem.\n");
858
859 if (genl_register_family(&mptcp_genl_family))
860 panic("Failed to register MPTCP PM netlink family\n");
861 }
Linux with added FPC-III support