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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Management Component Transport Protocol (MCTP) - routing
4 * implementation.
5 *
6 * This is currently based on a simple routing table, with no dst cache. The
7 * number of routes should stay fairly small, so the lookup cost is small.
8 *
9 * Copyright (c) 2021 Code Construct
10 * Copyright (c) 2021 Google
11 */
12
13#include <linux/idr.h>
14#include <linux/kconfig.h>
15#include <linux/mctp.h>
16#include <linux/netdevice.h>
17#include <linux/rtnetlink.h>
18#include <linux/skbuff.h>
19
20#include <uapi/linux/if_arp.h>
21
22#include <net/mctp.h>
23#include <net/mctpdevice.h>
24#include <net/netlink.h>
25#include <net/sock.h>
26
27#include <trace/events/mctp.h>
28
29static const unsigned int mctp_message_maxlen = 64 * 1024;
30static const unsigned long mctp_key_lifetime = 6 * CONFIG_HZ;
31
32static void mctp_flow_prepare_output(struct sk_buff *skb, struct mctp_dev *dev);
33
34/* route output callbacks */
35static int mctp_route_discard(struct mctp_route *route, struct sk_buff *skb)
36{
37 kfree_skb(skb);
38 return 0;
39}
40
41static struct mctp_sock *mctp_lookup_bind(struct net *net, struct sk_buff *skb)
42{
43 struct mctp_skb_cb *cb = mctp_cb(skb);
44 struct mctp_hdr *mh;
45 struct sock *sk;
46 u8 type;
47
48 WARN_ON(!rcu_read_lock_held());
49
50 /* TODO: look up in skb->cb? */
51 mh = mctp_hdr(skb);
52
53 if (!skb_headlen(skb))
54 return NULL;
55
56 type = (*(u8 *)skb->data) & 0x7f;
57
58 sk_for_each_rcu(sk, &net->mctp.binds) {
59 struct mctp_sock *msk = container_of(sk, struct mctp_sock, sk);
60
61 if (msk->bind_net != MCTP_NET_ANY && msk->bind_net != cb->net)
62 continue;
63
64 if (msk->bind_type != type)
65 continue;
66
67 if (!mctp_address_matches(msk->bind_addr, mh->dest))
68 continue;
69
70 return msk;
71 }
72
73 return NULL;
74}
75
76/* A note on the key allocations.
77 *
78 * struct net->mctp.keys contains our set of currently-allocated keys for
79 * MCTP tag management. The lookup tuple for these is the peer EID,
80 * local EID and MCTP tag.
81 *
82 * In some cases, the peer EID may be MCTP_EID_ANY: for example, when a
83 * broadcast message is sent, we may receive responses from any peer EID.
84 * Because the broadcast dest address is equivalent to ANY, we create
85 * a key with (local = local-eid, peer = ANY). This allows a match on the
86 * incoming broadcast responses from any peer.
87 *
88 * We perform lookups when packets are received, and when tags are allocated
89 * in two scenarios:
90 *
91 * - when a packet is sent, with a locally-owned tag: we need to find an
92 * unused tag value for the (local, peer) EID pair.
93 *
94 * - when a tag is manually allocated: we need to find an unused tag value
95 * for the peer EID, but don't have a specific local EID at that stage.
96 *
97 * in the latter case, on successful allocation, we end up with a tag with
98 * (local = ANY, peer = peer-eid).
99 *
100 * So, the key set allows both a local EID of ANY, as well as a peer EID of
101 * ANY in the lookup tuple. Both may be ANY if we prealloc for a broadcast.
102 * The matching (in mctp_key_match()) during lookup allows the match value to
103 * be ANY in either the dest or source addresses.
104 *
105 * When allocating (+ inserting) a tag, we need to check for conflicts amongst
106 * the existing tag set. This requires macthing either exactly on the local
107 * and peer addresses, or either being ANY.
108 */
109
110static bool mctp_key_match(struct mctp_sk_key *key, unsigned int net,
111 mctp_eid_t local, mctp_eid_t peer, u8 tag)
112{
113 if (key->net != net)
114 return false;
115
116 if (!mctp_address_matches(key->local_addr, local))
117 return false;
118
119 if (!mctp_address_matches(key->peer_addr, peer))
120 return false;
121
122 if (key->tag != tag)
123 return false;
124
125 return true;
126}
127
128/* returns a key (with key->lock held, and refcounted), or NULL if no such
129 * key exists.
130 */
131static struct mctp_sk_key *mctp_lookup_key(struct net *net, struct sk_buff *skb,
132 unsigned int netid, mctp_eid_t peer,
133 unsigned long *irqflags)
134 __acquires(&key->lock)
135{
136 struct mctp_sk_key *key, *ret;
137 unsigned long flags;
138 struct mctp_hdr *mh;
139 u8 tag;
140
141 mh = mctp_hdr(skb);
142 tag = mh->flags_seq_tag & (MCTP_HDR_TAG_MASK | MCTP_HDR_FLAG_TO);
143
144 ret = NULL;
145 spin_lock_irqsave(&net->mctp.keys_lock, flags);
146
147 hlist_for_each_entry(key, &net->mctp.keys, hlist) {
148 if (!mctp_key_match(key, netid, mh->dest, peer, tag))
149 continue;
150
151 spin_lock(&key->lock);
152 if (key->valid) {
153 refcount_inc(&key->refs);
154 ret = key;
155 break;
156 }
157 spin_unlock(&key->lock);
158 }
159
160 if (ret) {
161 spin_unlock(&net->mctp.keys_lock);
162 *irqflags = flags;
163 } else {
164 spin_unlock_irqrestore(&net->mctp.keys_lock, flags);
165 }
166
167 return ret;
168}
169
170static struct mctp_sk_key *mctp_key_alloc(struct mctp_sock *msk,
171 unsigned int net,
172 mctp_eid_t local, mctp_eid_t peer,
173 u8 tag, gfp_t gfp)
174{
175 struct mctp_sk_key *key;
176
177 key = kzalloc(sizeof(*key), gfp);
178 if (!key)
179 return NULL;
180
181 key->net = net;
182 key->peer_addr = peer;
183 key->local_addr = local;
184 key->tag = tag;
185 key->sk = &msk->sk;
186 key->valid = true;
187 spin_lock_init(&key->lock);
188 refcount_set(&key->refs, 1);
189 sock_hold(key->sk);
190
191 return key;
192}
193
194void mctp_key_unref(struct mctp_sk_key *key)
195{
196 unsigned long flags;
197
198 if (!refcount_dec_and_test(&key->refs))
199 return;
200
201 /* even though no refs exist here, the lock allows us to stay
202 * consistent with the locking requirement of mctp_dev_release_key
203 */
204 spin_lock_irqsave(&key->lock, flags);
205 mctp_dev_release_key(key->dev, key);
206 spin_unlock_irqrestore(&key->lock, flags);
207
208 sock_put(key->sk);
209 kfree(key);
210}
211
212static int mctp_key_add(struct mctp_sk_key *key, struct mctp_sock *msk)
213{
214 struct net *net = sock_net(&msk->sk);
215 struct mctp_sk_key *tmp;
216 unsigned long flags;
217 int rc = 0;
218
219 spin_lock_irqsave(&net->mctp.keys_lock, flags);
220
221 if (sock_flag(&msk->sk, SOCK_DEAD)) {
222 rc = -EINVAL;
223 goto out_unlock;
224 }
225
226 hlist_for_each_entry(tmp, &net->mctp.keys, hlist) {
227 if (mctp_key_match(tmp, key->net, key->local_addr,
228 key->peer_addr, key->tag)) {
229 spin_lock(&tmp->lock);
230 if (tmp->valid)
231 rc = -EEXIST;
232 spin_unlock(&tmp->lock);
233 if (rc)
234 break;
235 }
236 }
237
238 if (!rc) {
239 refcount_inc(&key->refs);
240 key->expiry = jiffies + mctp_key_lifetime;
241 timer_reduce(&msk->key_expiry, key->expiry);
242
243 hlist_add_head(&key->hlist, &net->mctp.keys);
244 hlist_add_head(&key->sklist, &msk->keys);
245 }
246
247out_unlock:
248 spin_unlock_irqrestore(&net->mctp.keys_lock, flags);
249
250 return rc;
251}
252
253/* Helper for mctp_route_input().
254 * We're done with the key; unlock and unref the key.
255 * For the usual case of automatic expiry we remove the key from lists.
256 * In the case that manual allocation is set on a key we release the lock
257 * and local ref, reset reassembly, but don't remove from lists.
258 */
259static void __mctp_key_done_in(struct mctp_sk_key *key, struct net *net,
260 unsigned long flags, unsigned long reason)
261__releases(&key->lock)
262{
263 struct sk_buff *skb;
264
265 trace_mctp_key_release(key, reason);
266 skb = key->reasm_head;
267 key->reasm_head = NULL;
268
269 if (!key->manual_alloc) {
270 key->reasm_dead = true;
271 key->valid = false;
272 mctp_dev_release_key(key->dev, key);
273 }
274 spin_unlock_irqrestore(&key->lock, flags);
275
276 if (!key->manual_alloc) {
277 spin_lock_irqsave(&net->mctp.keys_lock, flags);
278 if (!hlist_unhashed(&key->hlist)) {
279 hlist_del_init(&key->hlist);
280 hlist_del_init(&key->sklist);
281 mctp_key_unref(key);
282 }
283 spin_unlock_irqrestore(&net->mctp.keys_lock, flags);
284 }
285
286 /* and one for the local reference */
287 mctp_key_unref(key);
288
289 kfree_skb(skb);
290}
291
292#ifdef CONFIG_MCTP_FLOWS
293static void mctp_skb_set_flow(struct sk_buff *skb, struct mctp_sk_key *key)
294{
295 struct mctp_flow *flow;
296
297 flow = skb_ext_add(skb, SKB_EXT_MCTP);
298 if (!flow)
299 return;
300
301 refcount_inc(&key->refs);
302 flow->key = key;
303}
304
305static void mctp_flow_prepare_output(struct sk_buff *skb, struct mctp_dev *dev)
306{
307 struct mctp_sk_key *key;
308 struct mctp_flow *flow;
309
310 flow = skb_ext_find(skb, SKB_EXT_MCTP);
311 if (!flow)
312 return;
313
314 key = flow->key;
315
316 if (WARN_ON(key->dev && key->dev != dev))
317 return;
318
319 mctp_dev_set_key(dev, key);
320}
321#else
322static void mctp_skb_set_flow(struct sk_buff *skb, struct mctp_sk_key *key) {}
323static void mctp_flow_prepare_output(struct sk_buff *skb, struct mctp_dev *dev) {}
324#endif
325
326static int mctp_frag_queue(struct mctp_sk_key *key, struct sk_buff *skb)
327{
328 struct mctp_hdr *hdr = mctp_hdr(skb);
329 u8 exp_seq, this_seq;
330
331 this_seq = (hdr->flags_seq_tag >> MCTP_HDR_SEQ_SHIFT)
332 & MCTP_HDR_SEQ_MASK;
333
334 if (!key->reasm_head) {
335 key->reasm_head = skb;
336 key->reasm_tailp = &(skb_shinfo(skb)->frag_list);
337 key->last_seq = this_seq;
338 return 0;
339 }
340
341 exp_seq = (key->last_seq + 1) & MCTP_HDR_SEQ_MASK;
342
343 if (this_seq != exp_seq)
344 return -EINVAL;
345
346 if (key->reasm_head->len + skb->len > mctp_message_maxlen)
347 return -EINVAL;
348
349 skb->next = NULL;
350 skb->sk = NULL;
351 *key->reasm_tailp = skb;
352 key->reasm_tailp = &skb->next;
353
354 key->last_seq = this_seq;
355
356 key->reasm_head->data_len += skb->len;
357 key->reasm_head->len += skb->len;
358 key->reasm_head->truesize += skb->truesize;
359
360 return 0;
361}
362
363static int mctp_route_input(struct mctp_route *route, struct sk_buff *skb)
364{
365 struct mctp_sk_key *key, *any_key = NULL;
366 struct net *net = dev_net(skb->dev);
367 struct mctp_sock *msk;
368 struct mctp_hdr *mh;
369 unsigned int netid;
370 unsigned long f;
371 u8 tag, flags;
372 int rc;
373
374 msk = NULL;
375 rc = -EINVAL;
376
377 /* We may be receiving a locally-routed packet; drop source sk
378 * accounting.
379 *
380 * From here, we will either queue the skb - either to a frag_queue, or
381 * to a receiving socket. When that succeeds, we clear the skb pointer;
382 * a non-NULL skb on exit will be otherwise unowned, and hence
383 * kfree_skb()-ed.
384 */
385 skb_orphan(skb);
386
387 /* ensure we have enough data for a header and a type */
388 if (skb->len < sizeof(struct mctp_hdr) + 1)
389 goto out;
390
391 /* grab header, advance data ptr */
392 mh = mctp_hdr(skb);
393 netid = mctp_cb(skb)->net;
394 skb_pull(skb, sizeof(struct mctp_hdr));
395
396 if (mh->ver != 1)
397 goto out;
398
399 flags = mh->flags_seq_tag & (MCTP_HDR_FLAG_SOM | MCTP_HDR_FLAG_EOM);
400 tag = mh->flags_seq_tag & (MCTP_HDR_TAG_MASK | MCTP_HDR_FLAG_TO);
401
402 rcu_read_lock();
403
404 /* lookup socket / reasm context, exactly matching (src,dest,tag).
405 * we hold a ref on the key, and key->lock held.
406 */
407 key = mctp_lookup_key(net, skb, netid, mh->src, &f);
408
409 if (flags & MCTP_HDR_FLAG_SOM) {
410 if (key) {
411 msk = container_of(key->sk, struct mctp_sock, sk);
412 } else {
413 /* first response to a broadcast? do a more general
414 * key lookup to find the socket, but don't use this
415 * key for reassembly - we'll create a more specific
416 * one for future packets if required (ie, !EOM).
417 *
418 * this lookup requires key->peer to be MCTP_ADDR_ANY,
419 * it doesn't match just any key->peer.
420 */
421 any_key = mctp_lookup_key(net, skb, netid,
422 MCTP_ADDR_ANY, &f);
423 if (any_key) {
424 msk = container_of(any_key->sk,
425 struct mctp_sock, sk);
426 spin_unlock_irqrestore(&any_key->lock, f);
427 }
428 }
429
430 if (!key && !msk && (tag & MCTP_HDR_FLAG_TO))
431 msk = mctp_lookup_bind(net, skb);
432
433 if (!msk) {
434 rc = -ENOENT;
435 goto out_unlock;
436 }
437
438 /* single-packet message? deliver to socket, clean up any
439 * pending key.
440 */
441 if (flags & MCTP_HDR_FLAG_EOM) {
442 rc = sock_queue_rcv_skb(&msk->sk, skb);
443 if (!rc)
444 skb = NULL;
445 if (key) {
446 /* we've hit a pending reassembly; not much we
447 * can do but drop it
448 */
449 __mctp_key_done_in(key, net, f,
450 MCTP_TRACE_KEY_REPLIED);
451 key = NULL;
452 }
453 goto out_unlock;
454 }
455
456 /* broadcast response or a bind() - create a key for further
457 * packets for this message
458 */
459 if (!key) {
460 key = mctp_key_alloc(msk, netid, mh->dest, mh->src,
461 tag, GFP_ATOMIC);
462 if (!key) {
463 rc = -ENOMEM;
464 goto out_unlock;
465 }
466
467 /* we can queue without the key lock here, as the
468 * key isn't observable yet
469 */
470 mctp_frag_queue(key, skb);
471
472 /* if the key_add fails, we've raced with another
473 * SOM packet with the same src, dest and tag. There's
474 * no way to distinguish future packets, so all we
475 * can do is drop; we'll free the skb on exit from
476 * this function.
477 */
478 rc = mctp_key_add(key, msk);
479 if (!rc) {
480 trace_mctp_key_acquire(key);
481 skb = NULL;
482 }
483
484 /* we don't need to release key->lock on exit, so
485 * clean up here and suppress the unlock via
486 * setting to NULL
487 */
488 mctp_key_unref(key);
489 key = NULL;
490
491 } else {
492 if (key->reasm_head || key->reasm_dead) {
493 /* duplicate start? drop everything */
494 __mctp_key_done_in(key, net, f,
495 MCTP_TRACE_KEY_INVALIDATED);
496 rc = -EEXIST;
497 key = NULL;
498 } else {
499 rc = mctp_frag_queue(key, skb);
500 if (!rc)
501 skb = NULL;
502 }
503 }
504
505 } else if (key) {
506 /* this packet continues a previous message; reassemble
507 * using the message-specific key
508 */
509
510 /* we need to be continuing an existing reassembly... */
511 if (!key->reasm_head)
512 rc = -EINVAL;
513 else
514 rc = mctp_frag_queue(key, skb);
515
516 if (rc)
517 goto out_unlock;
518
519 /* we've queued; the queue owns the skb now */
520 skb = NULL;
521
522 /* end of message? deliver to socket, and we're done with
523 * the reassembly/response key
524 */
525 if (flags & MCTP_HDR_FLAG_EOM) {
526 rc = sock_queue_rcv_skb(key->sk, key->reasm_head);
527 if (!rc)
528 key->reasm_head = NULL;
529 __mctp_key_done_in(key, net, f, MCTP_TRACE_KEY_REPLIED);
530 key = NULL;
531 }
532
533 } else {
534 /* not a start, no matching key */
535 rc = -ENOENT;
536 }
537
538out_unlock:
539 rcu_read_unlock();
540 if (key) {
541 spin_unlock_irqrestore(&key->lock, f);
542 mctp_key_unref(key);
543 }
544 if (any_key)
545 mctp_key_unref(any_key);
546out:
547 kfree_skb(skb);
548 return rc;
549}
550
551static unsigned int mctp_route_mtu(struct mctp_route *rt)
552{
553 return rt->mtu ?: READ_ONCE(rt->dev->dev->mtu);
554}
555
556static int mctp_route_output(struct mctp_route *route, struct sk_buff *skb)
557{
558 struct mctp_skb_cb *cb = mctp_cb(skb);
559 struct mctp_hdr *hdr = mctp_hdr(skb);
560 char daddr_buf[MAX_ADDR_LEN];
561 char *daddr = NULL;
562 unsigned int mtu;
563 int rc;
564
565 skb->protocol = htons(ETH_P_MCTP);
566
567 mtu = READ_ONCE(skb->dev->mtu);
568 if (skb->len > mtu) {
569 kfree_skb(skb);
570 return -EMSGSIZE;
571 }
572
573 if (cb->ifindex) {
574 /* direct route; use the hwaddr we stashed in sendmsg */
575 if (cb->halen != skb->dev->addr_len) {
576 /* sanity check, sendmsg should have already caught this */
577 kfree_skb(skb);
578 return -EMSGSIZE;
579 }
580 daddr = cb->haddr;
581 } else {
582 /* If lookup fails let the device handle daddr==NULL */
583 if (mctp_neigh_lookup(route->dev, hdr->dest, daddr_buf) == 0)
584 daddr = daddr_buf;
585 }
586
587 rc = dev_hard_header(skb, skb->dev, ntohs(skb->protocol),
588 daddr, skb->dev->dev_addr, skb->len);
589 if (rc < 0) {
590 kfree_skb(skb);
591 return -EHOSTUNREACH;
592 }
593
594 mctp_flow_prepare_output(skb, route->dev);
595
596 rc = dev_queue_xmit(skb);
597 if (rc)
598 rc = net_xmit_errno(rc);
599
600 return rc;
601}
602
603/* route alloc/release */
604static void mctp_route_release(struct mctp_route *rt)
605{
606 if (refcount_dec_and_test(&rt->refs)) {
607 mctp_dev_put(rt->dev);
608 kfree_rcu(rt, rcu);
609 }
610}
611
612/* returns a route with the refcount at 1 */
613static struct mctp_route *mctp_route_alloc(void)
614{
615 struct mctp_route *rt;
616
617 rt = kzalloc(sizeof(*rt), GFP_KERNEL);
618 if (!rt)
619 return NULL;
620
621 INIT_LIST_HEAD(&rt->list);
622 refcount_set(&rt->refs, 1);
623 rt->output = mctp_route_discard;
624
625 return rt;
626}
627
628unsigned int mctp_default_net(struct net *net)
629{
630 return READ_ONCE(net->mctp.default_net);
631}
632
633int mctp_default_net_set(struct net *net, unsigned int index)
634{
635 if (index == 0)
636 return -EINVAL;
637 WRITE_ONCE(net->mctp.default_net, index);
638 return 0;
639}
640
641/* tag management */
642static void mctp_reserve_tag(struct net *net, struct mctp_sk_key *key,
643 struct mctp_sock *msk)
644{
645 struct netns_mctp *mns = &net->mctp;
646
647 lockdep_assert_held(&mns->keys_lock);
648
649 key->expiry = jiffies + mctp_key_lifetime;
650 timer_reduce(&msk->key_expiry, key->expiry);
651
652 /* we hold the net->key_lock here, allowing updates to both
653 * then net and sk
654 */
655 hlist_add_head_rcu(&key->hlist, &mns->keys);
656 hlist_add_head_rcu(&key->sklist, &msk->keys);
657 refcount_inc(&key->refs);
658}
659
660/* Allocate a locally-owned tag value for (local, peer), and reserve
661 * it for the socket msk
662 */
663struct mctp_sk_key *mctp_alloc_local_tag(struct mctp_sock *msk,
664 unsigned int netid,
665 mctp_eid_t local, mctp_eid_t peer,
666 bool manual, u8 *tagp)
667{
668 struct net *net = sock_net(&msk->sk);
669 struct netns_mctp *mns = &net->mctp;
670 struct mctp_sk_key *key, *tmp;
671 unsigned long flags;
672 u8 tagbits;
673
674 /* for NULL destination EIDs, we may get a response from any peer */
675 if (peer == MCTP_ADDR_NULL)
676 peer = MCTP_ADDR_ANY;
677
678 /* be optimistic, alloc now */
679 key = mctp_key_alloc(msk, netid, local, peer, 0, GFP_KERNEL);
680 if (!key)
681 return ERR_PTR(-ENOMEM);
682
683 /* 8 possible tag values */
684 tagbits = 0xff;
685
686 spin_lock_irqsave(&mns->keys_lock, flags);
687
688 /* Walk through the existing keys, looking for potential conflicting
689 * tags. If we find a conflict, clear that bit from tagbits
690 */
691 hlist_for_each_entry(tmp, &mns->keys, hlist) {
692 /* We can check the lookup fields (*_addr, tag) without the
693 * lock held, they don't change over the lifetime of the key.
694 */
695
696 /* tags are net-specific */
697 if (tmp->net != netid)
698 continue;
699
700 /* if we don't own the tag, it can't conflict */
701 if (tmp->tag & MCTP_HDR_FLAG_TO)
702 continue;
703
704 /* Since we're avoiding conflicting entries, match peer and
705 * local addresses, including with a wildcard on ANY. See
706 * 'A note on key allocations' for background.
707 */
708 if (peer != MCTP_ADDR_ANY &&
709 !mctp_address_matches(tmp->peer_addr, peer))
710 continue;
711
712 if (local != MCTP_ADDR_ANY &&
713 !mctp_address_matches(tmp->local_addr, local))
714 continue;
715
716 spin_lock(&tmp->lock);
717 /* key must still be valid. If we find a match, clear the
718 * potential tag value
719 */
720 if (tmp->valid)
721 tagbits &= ~(1 << tmp->tag);
722 spin_unlock(&tmp->lock);
723
724 if (!tagbits)
725 break;
726 }
727
728 if (tagbits) {
729 key->tag = __ffs(tagbits);
730 mctp_reserve_tag(net, key, msk);
731 trace_mctp_key_acquire(key);
732
733 key->manual_alloc = manual;
734 *tagp = key->tag;
735 }
736
737 spin_unlock_irqrestore(&mns->keys_lock, flags);
738
739 if (!tagbits) {
740 mctp_key_unref(key);
741 return ERR_PTR(-EBUSY);
742 }
743
744 return key;
745}
746
747static struct mctp_sk_key *mctp_lookup_prealloc_tag(struct mctp_sock *msk,
748 unsigned int netid,
749 mctp_eid_t daddr,
750 u8 req_tag, u8 *tagp)
751{
752 struct net *net = sock_net(&msk->sk);
753 struct netns_mctp *mns = &net->mctp;
754 struct mctp_sk_key *key, *tmp;
755 unsigned long flags;
756
757 req_tag &= ~(MCTP_TAG_PREALLOC | MCTP_TAG_OWNER);
758 key = NULL;
759
760 spin_lock_irqsave(&mns->keys_lock, flags);
761
762 hlist_for_each_entry(tmp, &mns->keys, hlist) {
763 if (tmp->net != netid)
764 continue;
765
766 if (tmp->tag != req_tag)
767 continue;
768
769 if (!mctp_address_matches(tmp->peer_addr, daddr))
770 continue;
771
772 if (!tmp->manual_alloc)
773 continue;
774
775 spin_lock(&tmp->lock);
776 if (tmp->valid) {
777 key = tmp;
778 refcount_inc(&key->refs);
779 spin_unlock(&tmp->lock);
780 break;
781 }
782 spin_unlock(&tmp->lock);
783 }
784 spin_unlock_irqrestore(&mns->keys_lock, flags);
785
786 if (!key)
787 return ERR_PTR(-ENOENT);
788
789 if (tagp)
790 *tagp = key->tag;
791
792 return key;
793}
794
795/* routing lookups */
796static bool mctp_rt_match_eid(struct mctp_route *rt,
797 unsigned int net, mctp_eid_t eid)
798{
799 return READ_ONCE(rt->dev->net) == net &&
800 rt->min <= eid && rt->max >= eid;
801}
802
803/* compares match, used for duplicate prevention */
804static bool mctp_rt_compare_exact(struct mctp_route *rt1,
805 struct mctp_route *rt2)
806{
807 ASSERT_RTNL();
808 return rt1->dev->net == rt2->dev->net &&
809 rt1->min == rt2->min &&
810 rt1->max == rt2->max;
811}
812
813struct mctp_route *mctp_route_lookup(struct net *net, unsigned int dnet,
814 mctp_eid_t daddr)
815{
816 struct mctp_route *tmp, *rt = NULL;
817
818 rcu_read_lock();
819
820 list_for_each_entry_rcu(tmp, &net->mctp.routes, list) {
821 /* TODO: add metrics */
822 if (mctp_rt_match_eid(tmp, dnet, daddr)) {
823 if (refcount_inc_not_zero(&tmp->refs)) {
824 rt = tmp;
825 break;
826 }
827 }
828 }
829
830 rcu_read_unlock();
831
832 return rt;
833}
834
835static struct mctp_route *mctp_route_lookup_null(struct net *net,
836 struct net_device *dev)
837{
838 struct mctp_route *tmp, *rt = NULL;
839
840 rcu_read_lock();
841
842 list_for_each_entry_rcu(tmp, &net->mctp.routes, list) {
843 if (tmp->dev->dev == dev && tmp->type == RTN_LOCAL &&
844 refcount_inc_not_zero(&tmp->refs)) {
845 rt = tmp;
846 break;
847 }
848 }
849
850 rcu_read_unlock();
851
852 return rt;
853}
854
855static int mctp_do_fragment_route(struct mctp_route *rt, struct sk_buff *skb,
856 unsigned int mtu, u8 tag)
857{
858 const unsigned int hlen = sizeof(struct mctp_hdr);
859 struct mctp_hdr *hdr, *hdr2;
860 unsigned int pos, size, headroom;
861 struct sk_buff *skb2;
862 int rc;
863 u8 seq;
864
865 hdr = mctp_hdr(skb);
866 seq = 0;
867 rc = 0;
868
869 if (mtu < hlen + 1) {
870 kfree_skb(skb);
871 return -EMSGSIZE;
872 }
873
874 /* keep same headroom as the original skb */
875 headroom = skb_headroom(skb);
876
877 /* we've got the header */
878 skb_pull(skb, hlen);
879
880 for (pos = 0; pos < skb->len;) {
881 /* size of message payload */
882 size = min(mtu - hlen, skb->len - pos);
883
884 skb2 = alloc_skb(headroom + hlen + size, GFP_KERNEL);
885 if (!skb2) {
886 rc = -ENOMEM;
887 break;
888 }
889
890 /* generic skb copy */
891 skb2->protocol = skb->protocol;
892 skb2->priority = skb->priority;
893 skb2->dev = skb->dev;
894 memcpy(skb2->cb, skb->cb, sizeof(skb2->cb));
895
896 if (skb->sk)
897 skb_set_owner_w(skb2, skb->sk);
898
899 /* establish packet */
900 skb_reserve(skb2, headroom);
901 skb_reset_network_header(skb2);
902 skb_put(skb2, hlen + size);
903 skb2->transport_header = skb2->network_header + hlen;
904
905 /* copy header fields, calculate SOM/EOM flags & seq */
906 hdr2 = mctp_hdr(skb2);
907 hdr2->ver = hdr->ver;
908 hdr2->dest = hdr->dest;
909 hdr2->src = hdr->src;
910 hdr2->flags_seq_tag = tag &
911 (MCTP_HDR_TAG_MASK | MCTP_HDR_FLAG_TO);
912
913 if (pos == 0)
914 hdr2->flags_seq_tag |= MCTP_HDR_FLAG_SOM;
915
916 if (pos + size == skb->len)
917 hdr2->flags_seq_tag |= MCTP_HDR_FLAG_EOM;
918
919 hdr2->flags_seq_tag |= seq << MCTP_HDR_SEQ_SHIFT;
920
921 /* copy message payload */
922 skb_copy_bits(skb, pos, skb_transport_header(skb2), size);
923
924 /* we need to copy the extensions, for MCTP flow data */
925 skb_ext_copy(skb2, skb);
926
927 /* do route */
928 rc = rt->output(rt, skb2);
929 if (rc)
930 break;
931
932 seq = (seq + 1) & MCTP_HDR_SEQ_MASK;
933 pos += size;
934 }
935
936 consume_skb(skb);
937 return rc;
938}
939
940int mctp_local_output(struct sock *sk, struct mctp_route *rt,
941 struct sk_buff *skb, mctp_eid_t daddr, u8 req_tag)
942{
943 struct mctp_sock *msk = container_of(sk, struct mctp_sock, sk);
944 struct mctp_skb_cb *cb = mctp_cb(skb);
945 struct mctp_route tmp_rt = {0};
946 struct mctp_sk_key *key;
947 struct mctp_hdr *hdr;
948 unsigned long flags;
949 unsigned int netid;
950 unsigned int mtu;
951 mctp_eid_t saddr;
952 bool ext_rt;
953 int rc;
954 u8 tag;
955
956 rc = -ENODEV;
957
958 if (rt) {
959 ext_rt = false;
960 if (WARN_ON(!rt->dev))
961 goto out_release;
962
963 } else if (cb->ifindex) {
964 struct net_device *dev;
965
966 ext_rt = true;
967 rt = &tmp_rt;
968
969 rcu_read_lock();
970 dev = dev_get_by_index_rcu(sock_net(sk), cb->ifindex);
971 if (!dev) {
972 rcu_read_unlock();
973 goto out_free;
974 }
975 rt->dev = __mctp_dev_get(dev);
976 rcu_read_unlock();
977
978 if (!rt->dev)
979 goto out_release;
980
981 /* establish temporary route - we set up enough to keep
982 * mctp_route_output happy
983 */
984 rt->output = mctp_route_output;
985 rt->mtu = 0;
986
987 } else {
988 rc = -EINVAL;
989 goto out_free;
990 }
991
992 spin_lock_irqsave(&rt->dev->addrs_lock, flags);
993 if (rt->dev->num_addrs == 0) {
994 rc = -EHOSTUNREACH;
995 } else {
996 /* use the outbound interface's first address as our source */
997 saddr = rt->dev->addrs[0];
998 rc = 0;
999 }
1000 spin_unlock_irqrestore(&rt->dev->addrs_lock, flags);
1001 netid = READ_ONCE(rt->dev->net);
1002
1003 if (rc)
1004 goto out_release;
1005
1006 if (req_tag & MCTP_TAG_OWNER) {
1007 if (req_tag & MCTP_TAG_PREALLOC)
1008 key = mctp_lookup_prealloc_tag(msk, netid, daddr,
1009 req_tag, &tag);
1010 else
1011 key = mctp_alloc_local_tag(msk, netid, saddr, daddr,
1012 false, &tag);
1013
1014 if (IS_ERR(key)) {
1015 rc = PTR_ERR(key);
1016 goto out_release;
1017 }
1018 mctp_skb_set_flow(skb, key);
1019 /* done with the key in this scope */
1020 mctp_key_unref(key);
1021 tag |= MCTP_HDR_FLAG_TO;
1022 } else {
1023 key = NULL;
1024 tag = req_tag & MCTP_TAG_MASK;
1025 }
1026
1027 skb->protocol = htons(ETH_P_MCTP);
1028 skb->priority = 0;
1029 skb_reset_transport_header(skb);
1030 skb_push(skb, sizeof(struct mctp_hdr));
1031 skb_reset_network_header(skb);
1032 skb->dev = rt->dev->dev;
1033
1034 /* cb->net will have been set on initial ingress */
1035 cb->src = saddr;
1036
1037 /* set up common header fields */
1038 hdr = mctp_hdr(skb);
1039 hdr->ver = 1;
1040 hdr->dest = daddr;
1041 hdr->src = saddr;
1042
1043 mtu = mctp_route_mtu(rt);
1044
1045 if (skb->len + sizeof(struct mctp_hdr) <= mtu) {
1046 hdr->flags_seq_tag = MCTP_HDR_FLAG_SOM |
1047 MCTP_HDR_FLAG_EOM | tag;
1048 rc = rt->output(rt, skb);
1049 } else {
1050 rc = mctp_do_fragment_route(rt, skb, mtu, tag);
1051 }
1052
1053 /* route output functions consume the skb, even on error */
1054 skb = NULL;
1055
1056out_release:
1057 if (!ext_rt)
1058 mctp_route_release(rt);
1059
1060 mctp_dev_put(tmp_rt.dev);
1061
1062out_free:
1063 kfree_skb(skb);
1064 return rc;
1065}
1066
1067/* route management */
1068static int mctp_route_add(struct mctp_dev *mdev, mctp_eid_t daddr_start,
1069 unsigned int daddr_extent, unsigned int mtu,
1070 unsigned char type)
1071{
1072 int (*rtfn)(struct mctp_route *rt, struct sk_buff *skb);
1073 struct net *net = dev_net(mdev->dev);
1074 struct mctp_route *rt, *ert;
1075
1076 if (!mctp_address_unicast(daddr_start))
1077 return -EINVAL;
1078
1079 if (daddr_extent > 0xff || daddr_start + daddr_extent >= 255)
1080 return -EINVAL;
1081
1082 switch (type) {
1083 case RTN_LOCAL:
1084 rtfn = mctp_route_input;
1085 break;
1086 case RTN_UNICAST:
1087 rtfn = mctp_route_output;
1088 break;
1089 default:
1090 return -EINVAL;
1091 }
1092
1093 rt = mctp_route_alloc();
1094 if (!rt)
1095 return -ENOMEM;
1096
1097 rt->min = daddr_start;
1098 rt->max = daddr_start + daddr_extent;
1099 rt->mtu = mtu;
1100 rt->dev = mdev;
1101 mctp_dev_hold(rt->dev);
1102 rt->type = type;
1103 rt->output = rtfn;
1104
1105 ASSERT_RTNL();
1106 /* Prevent duplicate identical routes. */
1107 list_for_each_entry(ert, &net->mctp.routes, list) {
1108 if (mctp_rt_compare_exact(rt, ert)) {
1109 mctp_route_release(rt);
1110 return -EEXIST;
1111 }
1112 }
1113
1114 list_add_rcu(&rt->list, &net->mctp.routes);
1115
1116 return 0;
1117}
1118
1119static int mctp_route_remove(struct mctp_dev *mdev, mctp_eid_t daddr_start,
1120 unsigned int daddr_extent, unsigned char type)
1121{
1122 struct net *net = dev_net(mdev->dev);
1123 struct mctp_route *rt, *tmp;
1124 mctp_eid_t daddr_end;
1125 bool dropped;
1126
1127 if (daddr_extent > 0xff || daddr_start + daddr_extent >= 255)
1128 return -EINVAL;
1129
1130 daddr_end = daddr_start + daddr_extent;
1131 dropped = false;
1132
1133 ASSERT_RTNL();
1134
1135 list_for_each_entry_safe(rt, tmp, &net->mctp.routes, list) {
1136 if (rt->dev == mdev &&
1137 rt->min == daddr_start && rt->max == daddr_end &&
1138 rt->type == type) {
1139 list_del_rcu(&rt->list);
1140 /* TODO: immediate RTM_DELROUTE */
1141 mctp_route_release(rt);
1142 dropped = true;
1143 }
1144 }
1145
1146 return dropped ? 0 : -ENOENT;
1147}
1148
1149int mctp_route_add_local(struct mctp_dev *mdev, mctp_eid_t addr)
1150{
1151 return mctp_route_add(mdev, addr, 0, 0, RTN_LOCAL);
1152}
1153
1154int mctp_route_remove_local(struct mctp_dev *mdev, mctp_eid_t addr)
1155{
1156 return mctp_route_remove(mdev, addr, 0, RTN_LOCAL);
1157}
1158
1159/* removes all entries for a given device */
1160void mctp_route_remove_dev(struct mctp_dev *mdev)
1161{
1162 struct net *net = dev_net(mdev->dev);
1163 struct mctp_route *rt, *tmp;
1164
1165 ASSERT_RTNL();
1166 list_for_each_entry_safe(rt, tmp, &net->mctp.routes, list) {
1167 if (rt->dev == mdev) {
1168 list_del_rcu(&rt->list);
1169 /* TODO: immediate RTM_DELROUTE */
1170 mctp_route_release(rt);
1171 }
1172 }
1173}
1174
1175/* Incoming packet-handling */
1176
1177static int mctp_pkttype_receive(struct sk_buff *skb, struct net_device *dev,
1178 struct packet_type *pt,
1179 struct net_device *orig_dev)
1180{
1181 struct net *net = dev_net(dev);
1182 struct mctp_dev *mdev;
1183 struct mctp_skb_cb *cb;
1184 struct mctp_route *rt;
1185 struct mctp_hdr *mh;
1186
1187 rcu_read_lock();
1188 mdev = __mctp_dev_get(dev);
1189 rcu_read_unlock();
1190 if (!mdev) {
1191 /* basic non-data sanity checks */
1192 goto err_drop;
1193 }
1194
1195 if (!pskb_may_pull(skb, sizeof(struct mctp_hdr)))
1196 goto err_drop;
1197
1198 skb_reset_transport_header(skb);
1199 skb_reset_network_header(skb);
1200
1201 /* We have enough for a header; decode and route */
1202 mh = mctp_hdr(skb);
1203 if (mh->ver < MCTP_VER_MIN || mh->ver > MCTP_VER_MAX)
1204 goto err_drop;
1205
1206 /* source must be valid unicast or null; drop reserved ranges and
1207 * broadcast
1208 */
1209 if (!(mctp_address_unicast(mh->src) || mctp_address_null(mh->src)))
1210 goto err_drop;
1211
1212 /* dest address: as above, but allow broadcast */
1213 if (!(mctp_address_unicast(mh->dest) || mctp_address_null(mh->dest) ||
1214 mctp_address_broadcast(mh->dest)))
1215 goto err_drop;
1216
1217 /* MCTP drivers must populate halen/haddr */
1218 if (dev->type == ARPHRD_MCTP) {
1219 cb = mctp_cb(skb);
1220 } else {
1221 cb = __mctp_cb(skb);
1222 cb->halen = 0;
1223 }
1224 cb->net = READ_ONCE(mdev->net);
1225 cb->ifindex = dev->ifindex;
1226
1227 rt = mctp_route_lookup(net, cb->net, mh->dest);
1228
1229 /* NULL EID, but addressed to our physical address */
1230 if (!rt && mh->dest == MCTP_ADDR_NULL && skb->pkt_type == PACKET_HOST)
1231 rt = mctp_route_lookup_null(net, dev);
1232
1233 if (!rt)
1234 goto err_drop;
1235
1236 rt->output(rt, skb);
1237 mctp_route_release(rt);
1238 mctp_dev_put(mdev);
1239
1240 return NET_RX_SUCCESS;
1241
1242err_drop:
1243 kfree_skb(skb);
1244 mctp_dev_put(mdev);
1245 return NET_RX_DROP;
1246}
1247
1248static struct packet_type mctp_packet_type = {
1249 .type = cpu_to_be16(ETH_P_MCTP),
1250 .func = mctp_pkttype_receive,
1251};
1252
1253/* netlink interface */
1254
1255static const struct nla_policy rta_mctp_policy[RTA_MAX + 1] = {
1256 [RTA_DST] = { .type = NLA_U8 },
1257 [RTA_METRICS] = { .type = NLA_NESTED },
1258 [RTA_OIF] = { .type = NLA_U32 },
1259};
1260
1261/* Common part for RTM_NEWROUTE and RTM_DELROUTE parsing.
1262 * tb must hold RTA_MAX+1 elements.
1263 */
1264static int mctp_route_nlparse(struct sk_buff *skb, struct nlmsghdr *nlh,
1265 struct netlink_ext_ack *extack,
1266 struct nlattr **tb, struct rtmsg **rtm,
1267 struct mctp_dev **mdev, mctp_eid_t *daddr_start)
1268{
1269 struct net *net = sock_net(skb->sk);
1270 struct net_device *dev;
1271 unsigned int ifindex;
1272 int rc;
1273
1274 rc = nlmsg_parse(nlh, sizeof(struct rtmsg), tb, RTA_MAX,
1275 rta_mctp_policy, extack);
1276 if (rc < 0) {
1277 NL_SET_ERR_MSG(extack, "incorrect format");
1278 return rc;
1279 }
1280
1281 if (!tb[RTA_DST]) {
1282 NL_SET_ERR_MSG(extack, "dst EID missing");
1283 return -EINVAL;
1284 }
1285 *daddr_start = nla_get_u8(tb[RTA_DST]);
1286
1287 if (!tb[RTA_OIF]) {
1288 NL_SET_ERR_MSG(extack, "ifindex missing");
1289 return -EINVAL;
1290 }
1291 ifindex = nla_get_u32(tb[RTA_OIF]);
1292
1293 *rtm = nlmsg_data(nlh);
1294 if ((*rtm)->rtm_family != AF_MCTP) {
1295 NL_SET_ERR_MSG(extack, "route family must be AF_MCTP");
1296 return -EINVAL;
1297 }
1298
1299 dev = __dev_get_by_index(net, ifindex);
1300 if (!dev) {
1301 NL_SET_ERR_MSG(extack, "bad ifindex");
1302 return -ENODEV;
1303 }
1304 *mdev = mctp_dev_get_rtnl(dev);
1305 if (!*mdev)
1306 return -ENODEV;
1307
1308 if (dev->flags & IFF_LOOPBACK) {
1309 NL_SET_ERR_MSG(extack, "no routes to loopback");
1310 return -EINVAL;
1311 }
1312
1313 return 0;
1314}
1315
1316static const struct nla_policy rta_metrics_policy[RTAX_MAX + 1] = {
1317 [RTAX_MTU] = { .type = NLA_U32 },
1318};
1319
1320static int mctp_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
1321 struct netlink_ext_ack *extack)
1322{
1323 struct nlattr *tb[RTA_MAX + 1];
1324 struct nlattr *tbx[RTAX_MAX + 1];
1325 mctp_eid_t daddr_start;
1326 struct mctp_dev *mdev;
1327 struct rtmsg *rtm;
1328 unsigned int mtu;
1329 int rc;
1330
1331 rc = mctp_route_nlparse(skb, nlh, extack, tb,
1332 &rtm, &mdev, &daddr_start);
1333 if (rc < 0)
1334 return rc;
1335
1336 if (rtm->rtm_type != RTN_UNICAST) {
1337 NL_SET_ERR_MSG(extack, "rtm_type must be RTN_UNICAST");
1338 return -EINVAL;
1339 }
1340
1341 mtu = 0;
1342 if (tb[RTA_METRICS]) {
1343 rc = nla_parse_nested(tbx, RTAX_MAX, tb[RTA_METRICS],
1344 rta_metrics_policy, NULL);
1345 if (rc < 0)
1346 return rc;
1347 if (tbx[RTAX_MTU])
1348 mtu = nla_get_u32(tbx[RTAX_MTU]);
1349 }
1350
1351 rc = mctp_route_add(mdev, daddr_start, rtm->rtm_dst_len, mtu,
1352 rtm->rtm_type);
1353 return rc;
1354}
1355
1356static int mctp_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
1357 struct netlink_ext_ack *extack)
1358{
1359 struct nlattr *tb[RTA_MAX + 1];
1360 mctp_eid_t daddr_start;
1361 struct mctp_dev *mdev;
1362 struct rtmsg *rtm;
1363 int rc;
1364
1365 rc = mctp_route_nlparse(skb, nlh, extack, tb,
1366 &rtm, &mdev, &daddr_start);
1367 if (rc < 0)
1368 return rc;
1369
1370 /* we only have unicast routes */
1371 if (rtm->rtm_type != RTN_UNICAST)
1372 return -EINVAL;
1373
1374 rc = mctp_route_remove(mdev, daddr_start, rtm->rtm_dst_len, RTN_UNICAST);
1375 return rc;
1376}
1377
1378static int mctp_fill_rtinfo(struct sk_buff *skb, struct mctp_route *rt,
1379 u32 portid, u32 seq, int event, unsigned int flags)
1380{
1381 struct nlmsghdr *nlh;
1382 struct rtmsg *hdr;
1383 void *metrics;
1384
1385 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*hdr), flags);
1386 if (!nlh)
1387 return -EMSGSIZE;
1388
1389 hdr = nlmsg_data(nlh);
1390 hdr->rtm_family = AF_MCTP;
1391
1392 /* we use the _len fields as a number of EIDs, rather than
1393 * a number of bits in the address
1394 */
1395 hdr->rtm_dst_len = rt->max - rt->min;
1396 hdr->rtm_src_len = 0;
1397 hdr->rtm_tos = 0;
1398 hdr->rtm_table = RT_TABLE_DEFAULT;
1399 hdr->rtm_protocol = RTPROT_STATIC; /* everything is user-defined */
1400 hdr->rtm_scope = RT_SCOPE_LINK; /* TODO: scope in mctp_route? */
1401 hdr->rtm_type = rt->type;
1402
1403 if (nla_put_u8(skb, RTA_DST, rt->min))
1404 goto cancel;
1405
1406 metrics = nla_nest_start_noflag(skb, RTA_METRICS);
1407 if (!metrics)
1408 goto cancel;
1409
1410 if (rt->mtu) {
1411 if (nla_put_u32(skb, RTAX_MTU, rt->mtu))
1412 goto cancel;
1413 }
1414
1415 nla_nest_end(skb, metrics);
1416
1417 if (rt->dev) {
1418 if (nla_put_u32(skb, RTA_OIF, rt->dev->dev->ifindex))
1419 goto cancel;
1420 }
1421
1422 /* TODO: conditional neighbour physaddr? */
1423
1424 nlmsg_end(skb, nlh);
1425
1426 return 0;
1427
1428cancel:
1429 nlmsg_cancel(skb, nlh);
1430 return -EMSGSIZE;
1431}
1432
1433static int mctp_dump_rtinfo(struct sk_buff *skb, struct netlink_callback *cb)
1434{
1435 struct net *net = sock_net(skb->sk);
1436 struct mctp_route *rt;
1437 int s_idx, idx;
1438
1439 /* TODO: allow filtering on route data, possibly under
1440 * cb->strict_check
1441 */
1442
1443 /* TODO: change to struct overlay */
1444 s_idx = cb->args[0];
1445 idx = 0;
1446
1447 rcu_read_lock();
1448 list_for_each_entry_rcu(rt, &net->mctp.routes, list) {
1449 if (idx++ < s_idx)
1450 continue;
1451 if (mctp_fill_rtinfo(skb, rt,
1452 NETLINK_CB(cb->skb).portid,
1453 cb->nlh->nlmsg_seq,
1454 RTM_NEWROUTE, NLM_F_MULTI) < 0)
1455 break;
1456 }
1457
1458 rcu_read_unlock();
1459 cb->args[0] = idx;
1460
1461 return skb->len;
1462}
1463
1464/* net namespace implementation */
1465static int __net_init mctp_routes_net_init(struct net *net)
1466{
1467 struct netns_mctp *ns = &net->mctp;
1468
1469 INIT_LIST_HEAD(&ns->routes);
1470 INIT_HLIST_HEAD(&ns->binds);
1471 mutex_init(&ns->bind_lock);
1472 INIT_HLIST_HEAD(&ns->keys);
1473 spin_lock_init(&ns->keys_lock);
1474 WARN_ON(mctp_default_net_set(net, MCTP_INITIAL_DEFAULT_NET));
1475 return 0;
1476}
1477
1478static void __net_exit mctp_routes_net_exit(struct net *net)
1479{
1480 struct mctp_route *rt;
1481
1482 rcu_read_lock();
1483 list_for_each_entry_rcu(rt, &net->mctp.routes, list)
1484 mctp_route_release(rt);
1485 rcu_read_unlock();
1486}
1487
1488static struct pernet_operations mctp_net_ops = {
1489 .init = mctp_routes_net_init,
1490 .exit = mctp_routes_net_exit,
1491};
1492
1493static const struct rtnl_msg_handler mctp_route_rtnl_msg_handlers[] = {
1494 {THIS_MODULE, PF_MCTP, RTM_NEWROUTE, mctp_newroute, NULL, 0},
1495 {THIS_MODULE, PF_MCTP, RTM_DELROUTE, mctp_delroute, NULL, 0},
1496 {THIS_MODULE, PF_MCTP, RTM_GETROUTE, NULL, mctp_dump_rtinfo, 0},
1497};
1498
1499int __init mctp_routes_init(void)
1500{
1501 int err;
1502
1503 dev_add_pack(&mctp_packet_type);
1504
1505 err = register_pernet_subsys(&mctp_net_ops);
1506 if (err)
1507 goto err_pernet;
1508
1509 err = rtnl_register_many(mctp_route_rtnl_msg_handlers);
1510 if (err)
1511 goto err_rtnl;
1512
1513 return 0;
1514
1515err_rtnl:
1516 unregister_pernet_subsys(&mctp_net_ops);
1517err_pernet:
1518 dev_remove_pack(&mctp_packet_type);
1519 return err;
1520}
1521
1522void mctp_routes_exit(void)
1523{
1524 rtnl_unregister_many(mctp_route_rtnl_msg_handlers);
1525 unregister_pernet_subsys(&mctp_net_ops);
1526 dev_remove_pack(&mctp_packet_type);
1527}
1528
1529#if IS_ENABLED(CONFIG_MCTP_TEST)
1530#include "test/route-test.c"
1531#endif
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Management Component Transport Protocol (MCTP) - routing
4 * implementation.
5 *
6 * This is currently based on a simple routing table, with no dst cache. The
7 * number of routes should stay fairly small, so the lookup cost is small.
8 *
9 * Copyright (c) 2021 Code Construct
10 * Copyright (c) 2021 Google
11 */
12
13#include <linux/idr.h>
14#include <linux/kconfig.h>
15#include <linux/mctp.h>
16#include <linux/netdevice.h>
17#include <linux/rtnetlink.h>
18#include <linux/skbuff.h>
19
20#include <uapi/linux/if_arp.h>
21
22#include <net/mctp.h>
23#include <net/mctpdevice.h>
24#include <net/netlink.h>
25#include <net/sock.h>
26
27#include <trace/events/mctp.h>
28
29static const unsigned int mctp_message_maxlen = 64 * 1024;
30static const unsigned long mctp_key_lifetime = 6 * CONFIG_HZ;
31
32static void mctp_flow_prepare_output(struct sk_buff *skb, struct mctp_dev *dev);
33
34/* route output callbacks */
35static int mctp_route_discard(struct mctp_route *route, struct sk_buff *skb)
36{
37 kfree_skb(skb);
38 return 0;
39}
40
41static struct mctp_sock *mctp_lookup_bind(struct net *net, struct sk_buff *skb)
42{
43 struct mctp_skb_cb *cb = mctp_cb(skb);
44 struct mctp_hdr *mh;
45 struct sock *sk;
46 u8 type;
47
48 WARN_ON(!rcu_read_lock_held());
49
50 /* TODO: look up in skb->cb? */
51 mh = mctp_hdr(skb);
52
53 if (!skb_headlen(skb))
54 return NULL;
55
56 type = (*(u8 *)skb->data) & 0x7f;
57
58 sk_for_each_rcu(sk, &net->mctp.binds) {
59 struct mctp_sock *msk = container_of(sk, struct mctp_sock, sk);
60
61 if (msk->bind_net != MCTP_NET_ANY && msk->bind_net != cb->net)
62 continue;
63
64 if (msk->bind_type != type)
65 continue;
66
67 if (!mctp_address_matches(msk->bind_addr, mh->dest))
68 continue;
69
70 return msk;
71 }
72
73 return NULL;
74}
75
76/* A note on the key allocations.
77 *
78 * struct net->mctp.keys contains our set of currently-allocated keys for
79 * MCTP tag management. The lookup tuple for these is the peer EID,
80 * local EID and MCTP tag.
81 *
82 * In some cases, the peer EID may be MCTP_EID_ANY: for example, when a
83 * broadcast message is sent, we may receive responses from any peer EID.
84 * Because the broadcast dest address is equivalent to ANY, we create
85 * a key with (local = local-eid, peer = ANY). This allows a match on the
86 * incoming broadcast responses from any peer.
87 *
88 * We perform lookups when packets are received, and when tags are allocated
89 * in two scenarios:
90 *
91 * - when a packet is sent, with a locally-owned tag: we need to find an
92 * unused tag value for the (local, peer) EID pair.
93 *
94 * - when a tag is manually allocated: we need to find an unused tag value
95 * for the peer EID, but don't have a specific local EID at that stage.
96 *
97 * in the latter case, on successful allocation, we end up with a tag with
98 * (local = ANY, peer = peer-eid).
99 *
100 * So, the key set allows both a local EID of ANY, as well as a peer EID of
101 * ANY in the lookup tuple. Both may be ANY if we prealloc for a broadcast.
102 * The matching (in mctp_key_match()) during lookup allows the match value to
103 * be ANY in either the dest or source addresses.
104 *
105 * When allocating (+ inserting) a tag, we need to check for conflicts amongst
106 * the existing tag set. This requires macthing either exactly on the local
107 * and peer addresses, or either being ANY.
108 */
109
110static bool mctp_key_match(struct mctp_sk_key *key, unsigned int net,
111 mctp_eid_t local, mctp_eid_t peer, u8 tag)
112{
113 if (key->net != net)
114 return false;
115
116 if (!mctp_address_matches(key->local_addr, local))
117 return false;
118
119 if (!mctp_address_matches(key->peer_addr, peer))
120 return false;
121
122 if (key->tag != tag)
123 return false;
124
125 return true;
126}
127
128/* returns a key (with key->lock held, and refcounted), or NULL if no such
129 * key exists.
130 */
131static struct mctp_sk_key *mctp_lookup_key(struct net *net, struct sk_buff *skb,
132 unsigned int netid, mctp_eid_t peer,
133 unsigned long *irqflags)
134 __acquires(&key->lock)
135{
136 struct mctp_sk_key *key, *ret;
137 unsigned long flags;
138 struct mctp_hdr *mh;
139 u8 tag;
140
141 mh = mctp_hdr(skb);
142 tag = mh->flags_seq_tag & (MCTP_HDR_TAG_MASK | MCTP_HDR_FLAG_TO);
143
144 ret = NULL;
145 spin_lock_irqsave(&net->mctp.keys_lock, flags);
146
147 hlist_for_each_entry(key, &net->mctp.keys, hlist) {
148 if (!mctp_key_match(key, netid, mh->dest, peer, tag))
149 continue;
150
151 spin_lock(&key->lock);
152 if (key->valid) {
153 refcount_inc(&key->refs);
154 ret = key;
155 break;
156 }
157 spin_unlock(&key->lock);
158 }
159
160 if (ret) {
161 spin_unlock(&net->mctp.keys_lock);
162 *irqflags = flags;
163 } else {
164 spin_unlock_irqrestore(&net->mctp.keys_lock, flags);
165 }
166
167 return ret;
168}
169
170static struct mctp_sk_key *mctp_key_alloc(struct mctp_sock *msk,
171 unsigned int net,
172 mctp_eid_t local, mctp_eid_t peer,
173 u8 tag, gfp_t gfp)
174{
175 struct mctp_sk_key *key;
176
177 key = kzalloc(sizeof(*key), gfp);
178 if (!key)
179 return NULL;
180
181 key->net = net;
182 key->peer_addr = peer;
183 key->local_addr = local;
184 key->tag = tag;
185 key->sk = &msk->sk;
186 key->valid = true;
187 spin_lock_init(&key->lock);
188 refcount_set(&key->refs, 1);
189 sock_hold(key->sk);
190
191 return key;
192}
193
194void mctp_key_unref(struct mctp_sk_key *key)
195{
196 unsigned long flags;
197
198 if (!refcount_dec_and_test(&key->refs))
199 return;
200
201 /* even though no refs exist here, the lock allows us to stay
202 * consistent with the locking requirement of mctp_dev_release_key
203 */
204 spin_lock_irqsave(&key->lock, flags);
205 mctp_dev_release_key(key->dev, key);
206 spin_unlock_irqrestore(&key->lock, flags);
207
208 sock_put(key->sk);
209 kfree(key);
210}
211
212static int mctp_key_add(struct mctp_sk_key *key, struct mctp_sock *msk)
213{
214 struct net *net = sock_net(&msk->sk);
215 struct mctp_sk_key *tmp;
216 unsigned long flags;
217 int rc = 0;
218
219 spin_lock_irqsave(&net->mctp.keys_lock, flags);
220
221 if (sock_flag(&msk->sk, SOCK_DEAD)) {
222 rc = -EINVAL;
223 goto out_unlock;
224 }
225
226 hlist_for_each_entry(tmp, &net->mctp.keys, hlist) {
227 if (mctp_key_match(tmp, key->net, key->local_addr,
228 key->peer_addr, key->tag)) {
229 spin_lock(&tmp->lock);
230 if (tmp->valid)
231 rc = -EEXIST;
232 spin_unlock(&tmp->lock);
233 if (rc)
234 break;
235 }
236 }
237
238 if (!rc) {
239 refcount_inc(&key->refs);
240 key->expiry = jiffies + mctp_key_lifetime;
241 timer_reduce(&msk->key_expiry, key->expiry);
242
243 hlist_add_head(&key->hlist, &net->mctp.keys);
244 hlist_add_head(&key->sklist, &msk->keys);
245 }
246
247out_unlock:
248 spin_unlock_irqrestore(&net->mctp.keys_lock, flags);
249
250 return rc;
251}
252
253/* Helper for mctp_route_input().
254 * We're done with the key; unlock and unref the key.
255 * For the usual case of automatic expiry we remove the key from lists.
256 * In the case that manual allocation is set on a key we release the lock
257 * and local ref, reset reassembly, but don't remove from lists.
258 */
259static void __mctp_key_done_in(struct mctp_sk_key *key, struct net *net,
260 unsigned long flags, unsigned long reason)
261__releases(&key->lock)
262{
263 struct sk_buff *skb;
264
265 trace_mctp_key_release(key, reason);
266 skb = key->reasm_head;
267 key->reasm_head = NULL;
268
269 if (!key->manual_alloc) {
270 key->reasm_dead = true;
271 key->valid = false;
272 mctp_dev_release_key(key->dev, key);
273 }
274 spin_unlock_irqrestore(&key->lock, flags);
275
276 if (!key->manual_alloc) {
277 spin_lock_irqsave(&net->mctp.keys_lock, flags);
278 if (!hlist_unhashed(&key->hlist)) {
279 hlist_del_init(&key->hlist);
280 hlist_del_init(&key->sklist);
281 mctp_key_unref(key);
282 }
283 spin_unlock_irqrestore(&net->mctp.keys_lock, flags);
284 }
285
286 /* and one for the local reference */
287 mctp_key_unref(key);
288
289 kfree_skb(skb);
290}
291
292#ifdef CONFIG_MCTP_FLOWS
293static void mctp_skb_set_flow(struct sk_buff *skb, struct mctp_sk_key *key)
294{
295 struct mctp_flow *flow;
296
297 flow = skb_ext_add(skb, SKB_EXT_MCTP);
298 if (!flow)
299 return;
300
301 refcount_inc(&key->refs);
302 flow->key = key;
303}
304
305static void mctp_flow_prepare_output(struct sk_buff *skb, struct mctp_dev *dev)
306{
307 struct mctp_sk_key *key;
308 struct mctp_flow *flow;
309
310 flow = skb_ext_find(skb, SKB_EXT_MCTP);
311 if (!flow)
312 return;
313
314 key = flow->key;
315
316 if (WARN_ON(key->dev && key->dev != dev))
317 return;
318
319 mctp_dev_set_key(dev, key);
320}
321#else
322static void mctp_skb_set_flow(struct sk_buff *skb, struct mctp_sk_key *key) {}
323static void mctp_flow_prepare_output(struct sk_buff *skb, struct mctp_dev *dev) {}
324#endif
325
326static int mctp_frag_queue(struct mctp_sk_key *key, struct sk_buff *skb)
327{
328 struct mctp_hdr *hdr = mctp_hdr(skb);
329 u8 exp_seq, this_seq;
330
331 this_seq = (hdr->flags_seq_tag >> MCTP_HDR_SEQ_SHIFT)
332 & MCTP_HDR_SEQ_MASK;
333
334 if (!key->reasm_head) {
335 key->reasm_head = skb;
336 key->reasm_tailp = &(skb_shinfo(skb)->frag_list);
337 key->last_seq = this_seq;
338 return 0;
339 }
340
341 exp_seq = (key->last_seq + 1) & MCTP_HDR_SEQ_MASK;
342
343 if (this_seq != exp_seq)
344 return -EINVAL;
345
346 if (key->reasm_head->len + skb->len > mctp_message_maxlen)
347 return -EINVAL;
348
349 skb->next = NULL;
350 skb->sk = NULL;
351 *key->reasm_tailp = skb;
352 key->reasm_tailp = &skb->next;
353
354 key->last_seq = this_seq;
355
356 key->reasm_head->data_len += skb->len;
357 key->reasm_head->len += skb->len;
358 key->reasm_head->truesize += skb->truesize;
359
360 return 0;
361}
362
363static int mctp_route_input(struct mctp_route *route, struct sk_buff *skb)
364{
365 struct mctp_sk_key *key, *any_key = NULL;
366 struct net *net = dev_net(skb->dev);
367 struct mctp_sock *msk;
368 struct mctp_hdr *mh;
369 unsigned int netid;
370 unsigned long f;
371 u8 tag, flags;
372 int rc;
373
374 msk = NULL;
375 rc = -EINVAL;
376
377 /* we may be receiving a locally-routed packet; drop source sk
378 * accounting
379 */
380 skb_orphan(skb);
381
382 /* ensure we have enough data for a header and a type */
383 if (skb->len < sizeof(struct mctp_hdr) + 1)
384 goto out;
385
386 /* grab header, advance data ptr */
387 mh = mctp_hdr(skb);
388 netid = mctp_cb(skb)->net;
389 skb_pull(skb, sizeof(struct mctp_hdr));
390
391 if (mh->ver != 1)
392 goto out;
393
394 flags = mh->flags_seq_tag & (MCTP_HDR_FLAG_SOM | MCTP_HDR_FLAG_EOM);
395 tag = mh->flags_seq_tag & (MCTP_HDR_TAG_MASK | MCTP_HDR_FLAG_TO);
396
397 rcu_read_lock();
398
399 /* lookup socket / reasm context, exactly matching (src,dest,tag).
400 * we hold a ref on the key, and key->lock held.
401 */
402 key = mctp_lookup_key(net, skb, netid, mh->src, &f);
403
404 if (flags & MCTP_HDR_FLAG_SOM) {
405 if (key) {
406 msk = container_of(key->sk, struct mctp_sock, sk);
407 } else {
408 /* first response to a broadcast? do a more general
409 * key lookup to find the socket, but don't use this
410 * key for reassembly - we'll create a more specific
411 * one for future packets if required (ie, !EOM).
412 *
413 * this lookup requires key->peer to be MCTP_ADDR_ANY,
414 * it doesn't match just any key->peer.
415 */
416 any_key = mctp_lookup_key(net, skb, netid,
417 MCTP_ADDR_ANY, &f);
418 if (any_key) {
419 msk = container_of(any_key->sk,
420 struct mctp_sock, sk);
421 spin_unlock_irqrestore(&any_key->lock, f);
422 }
423 }
424
425 if (!key && !msk && (tag & MCTP_HDR_FLAG_TO))
426 msk = mctp_lookup_bind(net, skb);
427
428 if (!msk) {
429 rc = -ENOENT;
430 goto out_unlock;
431 }
432
433 /* single-packet message? deliver to socket, clean up any
434 * pending key.
435 */
436 if (flags & MCTP_HDR_FLAG_EOM) {
437 sock_queue_rcv_skb(&msk->sk, skb);
438 if (key) {
439 /* we've hit a pending reassembly; not much we
440 * can do but drop it
441 */
442 __mctp_key_done_in(key, net, f,
443 MCTP_TRACE_KEY_REPLIED);
444 key = NULL;
445 }
446 rc = 0;
447 goto out_unlock;
448 }
449
450 /* broadcast response or a bind() - create a key for further
451 * packets for this message
452 */
453 if (!key) {
454 key = mctp_key_alloc(msk, netid, mh->dest, mh->src,
455 tag, GFP_ATOMIC);
456 if (!key) {
457 rc = -ENOMEM;
458 goto out_unlock;
459 }
460
461 /* we can queue without the key lock here, as the
462 * key isn't observable yet
463 */
464 mctp_frag_queue(key, skb);
465
466 /* if the key_add fails, we've raced with another
467 * SOM packet with the same src, dest and tag. There's
468 * no way to distinguish future packets, so all we
469 * can do is drop; we'll free the skb on exit from
470 * this function.
471 */
472 rc = mctp_key_add(key, msk);
473 if (!rc)
474 trace_mctp_key_acquire(key);
475
476 /* we don't need to release key->lock on exit, so
477 * clean up here and suppress the unlock via
478 * setting to NULL
479 */
480 mctp_key_unref(key);
481 key = NULL;
482
483 } else {
484 if (key->reasm_head || key->reasm_dead) {
485 /* duplicate start? drop everything */
486 __mctp_key_done_in(key, net, f,
487 MCTP_TRACE_KEY_INVALIDATED);
488 rc = -EEXIST;
489 key = NULL;
490 } else {
491 rc = mctp_frag_queue(key, skb);
492 }
493 }
494
495 } else if (key) {
496 /* this packet continues a previous message; reassemble
497 * using the message-specific key
498 */
499
500 /* we need to be continuing an existing reassembly... */
501 if (!key->reasm_head)
502 rc = -EINVAL;
503 else
504 rc = mctp_frag_queue(key, skb);
505
506 /* end of message? deliver to socket, and we're done with
507 * the reassembly/response key
508 */
509 if (!rc && flags & MCTP_HDR_FLAG_EOM) {
510 sock_queue_rcv_skb(key->sk, key->reasm_head);
511 key->reasm_head = NULL;
512 __mctp_key_done_in(key, net, f, MCTP_TRACE_KEY_REPLIED);
513 key = NULL;
514 }
515
516 } else {
517 /* not a start, no matching key */
518 rc = -ENOENT;
519 }
520
521out_unlock:
522 rcu_read_unlock();
523 if (key) {
524 spin_unlock_irqrestore(&key->lock, f);
525 mctp_key_unref(key);
526 }
527 if (any_key)
528 mctp_key_unref(any_key);
529out:
530 if (rc)
531 kfree_skb(skb);
532 return rc;
533}
534
535static unsigned int mctp_route_mtu(struct mctp_route *rt)
536{
537 return rt->mtu ?: READ_ONCE(rt->dev->dev->mtu);
538}
539
540static int mctp_route_output(struct mctp_route *route, struct sk_buff *skb)
541{
542 struct mctp_skb_cb *cb = mctp_cb(skb);
543 struct mctp_hdr *hdr = mctp_hdr(skb);
544 char daddr_buf[MAX_ADDR_LEN];
545 char *daddr = NULL;
546 unsigned int mtu;
547 int rc;
548
549 skb->protocol = htons(ETH_P_MCTP);
550
551 mtu = READ_ONCE(skb->dev->mtu);
552 if (skb->len > mtu) {
553 kfree_skb(skb);
554 return -EMSGSIZE;
555 }
556
557 if (cb->ifindex) {
558 /* direct route; use the hwaddr we stashed in sendmsg */
559 if (cb->halen != skb->dev->addr_len) {
560 /* sanity check, sendmsg should have already caught this */
561 kfree_skb(skb);
562 return -EMSGSIZE;
563 }
564 daddr = cb->haddr;
565 } else {
566 /* If lookup fails let the device handle daddr==NULL */
567 if (mctp_neigh_lookup(route->dev, hdr->dest, daddr_buf) == 0)
568 daddr = daddr_buf;
569 }
570
571 rc = dev_hard_header(skb, skb->dev, ntohs(skb->protocol),
572 daddr, skb->dev->dev_addr, skb->len);
573 if (rc < 0) {
574 kfree_skb(skb);
575 return -EHOSTUNREACH;
576 }
577
578 mctp_flow_prepare_output(skb, route->dev);
579
580 rc = dev_queue_xmit(skb);
581 if (rc)
582 rc = net_xmit_errno(rc);
583
584 return rc;
585}
586
587/* route alloc/release */
588static void mctp_route_release(struct mctp_route *rt)
589{
590 if (refcount_dec_and_test(&rt->refs)) {
591 mctp_dev_put(rt->dev);
592 kfree_rcu(rt, rcu);
593 }
594}
595
596/* returns a route with the refcount at 1 */
597static struct mctp_route *mctp_route_alloc(void)
598{
599 struct mctp_route *rt;
600
601 rt = kzalloc(sizeof(*rt), GFP_KERNEL);
602 if (!rt)
603 return NULL;
604
605 INIT_LIST_HEAD(&rt->list);
606 refcount_set(&rt->refs, 1);
607 rt->output = mctp_route_discard;
608
609 return rt;
610}
611
612unsigned int mctp_default_net(struct net *net)
613{
614 return READ_ONCE(net->mctp.default_net);
615}
616
617int mctp_default_net_set(struct net *net, unsigned int index)
618{
619 if (index == 0)
620 return -EINVAL;
621 WRITE_ONCE(net->mctp.default_net, index);
622 return 0;
623}
624
625/* tag management */
626static void mctp_reserve_tag(struct net *net, struct mctp_sk_key *key,
627 struct mctp_sock *msk)
628{
629 struct netns_mctp *mns = &net->mctp;
630
631 lockdep_assert_held(&mns->keys_lock);
632
633 key->expiry = jiffies + mctp_key_lifetime;
634 timer_reduce(&msk->key_expiry, key->expiry);
635
636 /* we hold the net->key_lock here, allowing updates to both
637 * then net and sk
638 */
639 hlist_add_head_rcu(&key->hlist, &mns->keys);
640 hlist_add_head_rcu(&key->sklist, &msk->keys);
641 refcount_inc(&key->refs);
642}
643
644/* Allocate a locally-owned tag value for (local, peer), and reserve
645 * it for the socket msk
646 */
647struct mctp_sk_key *mctp_alloc_local_tag(struct mctp_sock *msk,
648 unsigned int netid,
649 mctp_eid_t local, mctp_eid_t peer,
650 bool manual, u8 *tagp)
651{
652 struct net *net = sock_net(&msk->sk);
653 struct netns_mctp *mns = &net->mctp;
654 struct mctp_sk_key *key, *tmp;
655 unsigned long flags;
656 u8 tagbits;
657
658 /* for NULL destination EIDs, we may get a response from any peer */
659 if (peer == MCTP_ADDR_NULL)
660 peer = MCTP_ADDR_ANY;
661
662 /* be optimistic, alloc now */
663 key = mctp_key_alloc(msk, netid, local, peer, 0, GFP_KERNEL);
664 if (!key)
665 return ERR_PTR(-ENOMEM);
666
667 /* 8 possible tag values */
668 tagbits = 0xff;
669
670 spin_lock_irqsave(&mns->keys_lock, flags);
671
672 /* Walk through the existing keys, looking for potential conflicting
673 * tags. If we find a conflict, clear that bit from tagbits
674 */
675 hlist_for_each_entry(tmp, &mns->keys, hlist) {
676 /* We can check the lookup fields (*_addr, tag) without the
677 * lock held, they don't change over the lifetime of the key.
678 */
679
680 /* tags are net-specific */
681 if (tmp->net != netid)
682 continue;
683
684 /* if we don't own the tag, it can't conflict */
685 if (tmp->tag & MCTP_HDR_FLAG_TO)
686 continue;
687
688 /* Since we're avoiding conflicting entries, match peer and
689 * local addresses, including with a wildcard on ANY. See
690 * 'A note on key allocations' for background.
691 */
692 if (peer != MCTP_ADDR_ANY &&
693 !mctp_address_matches(tmp->peer_addr, peer))
694 continue;
695
696 if (local != MCTP_ADDR_ANY &&
697 !mctp_address_matches(tmp->local_addr, local))
698 continue;
699
700 spin_lock(&tmp->lock);
701 /* key must still be valid. If we find a match, clear the
702 * potential tag value
703 */
704 if (tmp->valid)
705 tagbits &= ~(1 << tmp->tag);
706 spin_unlock(&tmp->lock);
707
708 if (!tagbits)
709 break;
710 }
711
712 if (tagbits) {
713 key->tag = __ffs(tagbits);
714 mctp_reserve_tag(net, key, msk);
715 trace_mctp_key_acquire(key);
716
717 key->manual_alloc = manual;
718 *tagp = key->tag;
719 }
720
721 spin_unlock_irqrestore(&mns->keys_lock, flags);
722
723 if (!tagbits) {
724 mctp_key_unref(key);
725 return ERR_PTR(-EBUSY);
726 }
727
728 return key;
729}
730
731static struct mctp_sk_key *mctp_lookup_prealloc_tag(struct mctp_sock *msk,
732 unsigned int netid,
733 mctp_eid_t daddr,
734 u8 req_tag, u8 *tagp)
735{
736 struct net *net = sock_net(&msk->sk);
737 struct netns_mctp *mns = &net->mctp;
738 struct mctp_sk_key *key, *tmp;
739 unsigned long flags;
740
741 req_tag &= ~(MCTP_TAG_PREALLOC | MCTP_TAG_OWNER);
742 key = NULL;
743
744 spin_lock_irqsave(&mns->keys_lock, flags);
745
746 hlist_for_each_entry(tmp, &mns->keys, hlist) {
747 if (tmp->net != netid)
748 continue;
749
750 if (tmp->tag != req_tag)
751 continue;
752
753 if (!mctp_address_matches(tmp->peer_addr, daddr))
754 continue;
755
756 if (!tmp->manual_alloc)
757 continue;
758
759 spin_lock(&tmp->lock);
760 if (tmp->valid) {
761 key = tmp;
762 refcount_inc(&key->refs);
763 spin_unlock(&tmp->lock);
764 break;
765 }
766 spin_unlock(&tmp->lock);
767 }
768 spin_unlock_irqrestore(&mns->keys_lock, flags);
769
770 if (!key)
771 return ERR_PTR(-ENOENT);
772
773 if (tagp)
774 *tagp = key->tag;
775
776 return key;
777}
778
779/* routing lookups */
780static bool mctp_rt_match_eid(struct mctp_route *rt,
781 unsigned int net, mctp_eid_t eid)
782{
783 return READ_ONCE(rt->dev->net) == net &&
784 rt->min <= eid && rt->max >= eid;
785}
786
787/* compares match, used for duplicate prevention */
788static bool mctp_rt_compare_exact(struct mctp_route *rt1,
789 struct mctp_route *rt2)
790{
791 ASSERT_RTNL();
792 return rt1->dev->net == rt2->dev->net &&
793 rt1->min == rt2->min &&
794 rt1->max == rt2->max;
795}
796
797struct mctp_route *mctp_route_lookup(struct net *net, unsigned int dnet,
798 mctp_eid_t daddr)
799{
800 struct mctp_route *tmp, *rt = NULL;
801
802 rcu_read_lock();
803
804 list_for_each_entry_rcu(tmp, &net->mctp.routes, list) {
805 /* TODO: add metrics */
806 if (mctp_rt_match_eid(tmp, dnet, daddr)) {
807 if (refcount_inc_not_zero(&tmp->refs)) {
808 rt = tmp;
809 break;
810 }
811 }
812 }
813
814 rcu_read_unlock();
815
816 return rt;
817}
818
819static struct mctp_route *mctp_route_lookup_null(struct net *net,
820 struct net_device *dev)
821{
822 struct mctp_route *tmp, *rt = NULL;
823
824 rcu_read_lock();
825
826 list_for_each_entry_rcu(tmp, &net->mctp.routes, list) {
827 if (tmp->dev->dev == dev && tmp->type == RTN_LOCAL &&
828 refcount_inc_not_zero(&tmp->refs)) {
829 rt = tmp;
830 break;
831 }
832 }
833
834 rcu_read_unlock();
835
836 return rt;
837}
838
839static int mctp_do_fragment_route(struct mctp_route *rt, struct sk_buff *skb,
840 unsigned int mtu, u8 tag)
841{
842 const unsigned int hlen = sizeof(struct mctp_hdr);
843 struct mctp_hdr *hdr, *hdr2;
844 unsigned int pos, size, headroom;
845 struct sk_buff *skb2;
846 int rc;
847 u8 seq;
848
849 hdr = mctp_hdr(skb);
850 seq = 0;
851 rc = 0;
852
853 if (mtu < hlen + 1) {
854 kfree_skb(skb);
855 return -EMSGSIZE;
856 }
857
858 /* keep same headroom as the original skb */
859 headroom = skb_headroom(skb);
860
861 /* we've got the header */
862 skb_pull(skb, hlen);
863
864 for (pos = 0; pos < skb->len;) {
865 /* size of message payload */
866 size = min(mtu - hlen, skb->len - pos);
867
868 skb2 = alloc_skb(headroom + hlen + size, GFP_KERNEL);
869 if (!skb2) {
870 rc = -ENOMEM;
871 break;
872 }
873
874 /* generic skb copy */
875 skb2->protocol = skb->protocol;
876 skb2->priority = skb->priority;
877 skb2->dev = skb->dev;
878 memcpy(skb2->cb, skb->cb, sizeof(skb2->cb));
879
880 if (skb->sk)
881 skb_set_owner_w(skb2, skb->sk);
882
883 /* establish packet */
884 skb_reserve(skb2, headroom);
885 skb_reset_network_header(skb2);
886 skb_put(skb2, hlen + size);
887 skb2->transport_header = skb2->network_header + hlen;
888
889 /* copy header fields, calculate SOM/EOM flags & seq */
890 hdr2 = mctp_hdr(skb2);
891 hdr2->ver = hdr->ver;
892 hdr2->dest = hdr->dest;
893 hdr2->src = hdr->src;
894 hdr2->flags_seq_tag = tag &
895 (MCTP_HDR_TAG_MASK | MCTP_HDR_FLAG_TO);
896
897 if (pos == 0)
898 hdr2->flags_seq_tag |= MCTP_HDR_FLAG_SOM;
899
900 if (pos + size == skb->len)
901 hdr2->flags_seq_tag |= MCTP_HDR_FLAG_EOM;
902
903 hdr2->flags_seq_tag |= seq << MCTP_HDR_SEQ_SHIFT;
904
905 /* copy message payload */
906 skb_copy_bits(skb, pos, skb_transport_header(skb2), size);
907
908 /* we need to copy the extensions, for MCTP flow data */
909 skb_ext_copy(skb2, skb);
910
911 /* do route */
912 rc = rt->output(rt, skb2);
913 if (rc)
914 break;
915
916 seq = (seq + 1) & MCTP_HDR_SEQ_MASK;
917 pos += size;
918 }
919
920 consume_skb(skb);
921 return rc;
922}
923
924int mctp_local_output(struct sock *sk, struct mctp_route *rt,
925 struct sk_buff *skb, mctp_eid_t daddr, u8 req_tag)
926{
927 struct mctp_sock *msk = container_of(sk, struct mctp_sock, sk);
928 struct mctp_skb_cb *cb = mctp_cb(skb);
929 struct mctp_route tmp_rt = {0};
930 struct mctp_sk_key *key;
931 struct mctp_hdr *hdr;
932 unsigned long flags;
933 unsigned int netid;
934 unsigned int mtu;
935 mctp_eid_t saddr;
936 bool ext_rt;
937 int rc;
938 u8 tag;
939
940 rc = -ENODEV;
941
942 if (rt) {
943 ext_rt = false;
944 if (WARN_ON(!rt->dev))
945 goto out_release;
946
947 } else if (cb->ifindex) {
948 struct net_device *dev;
949
950 ext_rt = true;
951 rt = &tmp_rt;
952
953 rcu_read_lock();
954 dev = dev_get_by_index_rcu(sock_net(sk), cb->ifindex);
955 if (!dev) {
956 rcu_read_unlock();
957 goto out_free;
958 }
959 rt->dev = __mctp_dev_get(dev);
960 rcu_read_unlock();
961
962 if (!rt->dev)
963 goto out_release;
964
965 /* establish temporary route - we set up enough to keep
966 * mctp_route_output happy
967 */
968 rt->output = mctp_route_output;
969 rt->mtu = 0;
970
971 } else {
972 rc = -EINVAL;
973 goto out_free;
974 }
975
976 spin_lock_irqsave(&rt->dev->addrs_lock, flags);
977 if (rt->dev->num_addrs == 0) {
978 rc = -EHOSTUNREACH;
979 } else {
980 /* use the outbound interface's first address as our source */
981 saddr = rt->dev->addrs[0];
982 rc = 0;
983 }
984 spin_unlock_irqrestore(&rt->dev->addrs_lock, flags);
985 netid = READ_ONCE(rt->dev->net);
986
987 if (rc)
988 goto out_release;
989
990 if (req_tag & MCTP_TAG_OWNER) {
991 if (req_tag & MCTP_TAG_PREALLOC)
992 key = mctp_lookup_prealloc_tag(msk, netid, daddr,
993 req_tag, &tag);
994 else
995 key = mctp_alloc_local_tag(msk, netid, saddr, daddr,
996 false, &tag);
997
998 if (IS_ERR(key)) {
999 rc = PTR_ERR(key);
1000 goto out_release;
1001 }
1002 mctp_skb_set_flow(skb, key);
1003 /* done with the key in this scope */
1004 mctp_key_unref(key);
1005 tag |= MCTP_HDR_FLAG_TO;
1006 } else {
1007 key = NULL;
1008 tag = req_tag & MCTP_TAG_MASK;
1009 }
1010
1011 skb->protocol = htons(ETH_P_MCTP);
1012 skb->priority = 0;
1013 skb_reset_transport_header(skb);
1014 skb_push(skb, sizeof(struct mctp_hdr));
1015 skb_reset_network_header(skb);
1016 skb->dev = rt->dev->dev;
1017
1018 /* cb->net will have been set on initial ingress */
1019 cb->src = saddr;
1020
1021 /* set up common header fields */
1022 hdr = mctp_hdr(skb);
1023 hdr->ver = 1;
1024 hdr->dest = daddr;
1025 hdr->src = saddr;
1026
1027 mtu = mctp_route_mtu(rt);
1028
1029 if (skb->len + sizeof(struct mctp_hdr) <= mtu) {
1030 hdr->flags_seq_tag = MCTP_HDR_FLAG_SOM |
1031 MCTP_HDR_FLAG_EOM | tag;
1032 rc = rt->output(rt, skb);
1033 } else {
1034 rc = mctp_do_fragment_route(rt, skb, mtu, tag);
1035 }
1036
1037 /* route output functions consume the skb, even on error */
1038 skb = NULL;
1039
1040out_release:
1041 if (!ext_rt)
1042 mctp_route_release(rt);
1043
1044 mctp_dev_put(tmp_rt.dev);
1045
1046out_free:
1047 kfree_skb(skb);
1048 return rc;
1049}
1050
1051/* route management */
1052static int mctp_route_add(struct mctp_dev *mdev, mctp_eid_t daddr_start,
1053 unsigned int daddr_extent, unsigned int mtu,
1054 unsigned char type)
1055{
1056 int (*rtfn)(struct mctp_route *rt, struct sk_buff *skb);
1057 struct net *net = dev_net(mdev->dev);
1058 struct mctp_route *rt, *ert;
1059
1060 if (!mctp_address_unicast(daddr_start))
1061 return -EINVAL;
1062
1063 if (daddr_extent > 0xff || daddr_start + daddr_extent >= 255)
1064 return -EINVAL;
1065
1066 switch (type) {
1067 case RTN_LOCAL:
1068 rtfn = mctp_route_input;
1069 break;
1070 case RTN_UNICAST:
1071 rtfn = mctp_route_output;
1072 break;
1073 default:
1074 return -EINVAL;
1075 }
1076
1077 rt = mctp_route_alloc();
1078 if (!rt)
1079 return -ENOMEM;
1080
1081 rt->min = daddr_start;
1082 rt->max = daddr_start + daddr_extent;
1083 rt->mtu = mtu;
1084 rt->dev = mdev;
1085 mctp_dev_hold(rt->dev);
1086 rt->type = type;
1087 rt->output = rtfn;
1088
1089 ASSERT_RTNL();
1090 /* Prevent duplicate identical routes. */
1091 list_for_each_entry(ert, &net->mctp.routes, list) {
1092 if (mctp_rt_compare_exact(rt, ert)) {
1093 mctp_route_release(rt);
1094 return -EEXIST;
1095 }
1096 }
1097
1098 list_add_rcu(&rt->list, &net->mctp.routes);
1099
1100 return 0;
1101}
1102
1103static int mctp_route_remove(struct mctp_dev *mdev, mctp_eid_t daddr_start,
1104 unsigned int daddr_extent, unsigned char type)
1105{
1106 struct net *net = dev_net(mdev->dev);
1107 struct mctp_route *rt, *tmp;
1108 mctp_eid_t daddr_end;
1109 bool dropped;
1110
1111 if (daddr_extent > 0xff || daddr_start + daddr_extent >= 255)
1112 return -EINVAL;
1113
1114 daddr_end = daddr_start + daddr_extent;
1115 dropped = false;
1116
1117 ASSERT_RTNL();
1118
1119 list_for_each_entry_safe(rt, tmp, &net->mctp.routes, list) {
1120 if (rt->dev == mdev &&
1121 rt->min == daddr_start && rt->max == daddr_end &&
1122 rt->type == type) {
1123 list_del_rcu(&rt->list);
1124 /* TODO: immediate RTM_DELROUTE */
1125 mctp_route_release(rt);
1126 dropped = true;
1127 }
1128 }
1129
1130 return dropped ? 0 : -ENOENT;
1131}
1132
1133int mctp_route_add_local(struct mctp_dev *mdev, mctp_eid_t addr)
1134{
1135 return mctp_route_add(mdev, addr, 0, 0, RTN_LOCAL);
1136}
1137
1138int mctp_route_remove_local(struct mctp_dev *mdev, mctp_eid_t addr)
1139{
1140 return mctp_route_remove(mdev, addr, 0, RTN_LOCAL);
1141}
1142
1143/* removes all entries for a given device */
1144void mctp_route_remove_dev(struct mctp_dev *mdev)
1145{
1146 struct net *net = dev_net(mdev->dev);
1147 struct mctp_route *rt, *tmp;
1148
1149 ASSERT_RTNL();
1150 list_for_each_entry_safe(rt, tmp, &net->mctp.routes, list) {
1151 if (rt->dev == mdev) {
1152 list_del_rcu(&rt->list);
1153 /* TODO: immediate RTM_DELROUTE */
1154 mctp_route_release(rt);
1155 }
1156 }
1157}
1158
1159/* Incoming packet-handling */
1160
1161static int mctp_pkttype_receive(struct sk_buff *skb, struct net_device *dev,
1162 struct packet_type *pt,
1163 struct net_device *orig_dev)
1164{
1165 struct net *net = dev_net(dev);
1166 struct mctp_dev *mdev;
1167 struct mctp_skb_cb *cb;
1168 struct mctp_route *rt;
1169 struct mctp_hdr *mh;
1170
1171 rcu_read_lock();
1172 mdev = __mctp_dev_get(dev);
1173 rcu_read_unlock();
1174 if (!mdev) {
1175 /* basic non-data sanity checks */
1176 goto err_drop;
1177 }
1178
1179 if (!pskb_may_pull(skb, sizeof(struct mctp_hdr)))
1180 goto err_drop;
1181
1182 skb_reset_transport_header(skb);
1183 skb_reset_network_header(skb);
1184
1185 /* We have enough for a header; decode and route */
1186 mh = mctp_hdr(skb);
1187 if (mh->ver < MCTP_VER_MIN || mh->ver > MCTP_VER_MAX)
1188 goto err_drop;
1189
1190 /* source must be valid unicast or null; drop reserved ranges and
1191 * broadcast
1192 */
1193 if (!(mctp_address_unicast(mh->src) || mctp_address_null(mh->src)))
1194 goto err_drop;
1195
1196 /* dest address: as above, but allow broadcast */
1197 if (!(mctp_address_unicast(mh->dest) || mctp_address_null(mh->dest) ||
1198 mctp_address_broadcast(mh->dest)))
1199 goto err_drop;
1200
1201 /* MCTP drivers must populate halen/haddr */
1202 if (dev->type == ARPHRD_MCTP) {
1203 cb = mctp_cb(skb);
1204 } else {
1205 cb = __mctp_cb(skb);
1206 cb->halen = 0;
1207 }
1208 cb->net = READ_ONCE(mdev->net);
1209 cb->ifindex = dev->ifindex;
1210
1211 rt = mctp_route_lookup(net, cb->net, mh->dest);
1212
1213 /* NULL EID, but addressed to our physical address */
1214 if (!rt && mh->dest == MCTP_ADDR_NULL && skb->pkt_type == PACKET_HOST)
1215 rt = mctp_route_lookup_null(net, dev);
1216
1217 if (!rt)
1218 goto err_drop;
1219
1220 rt->output(rt, skb);
1221 mctp_route_release(rt);
1222 mctp_dev_put(mdev);
1223
1224 return NET_RX_SUCCESS;
1225
1226err_drop:
1227 kfree_skb(skb);
1228 mctp_dev_put(mdev);
1229 return NET_RX_DROP;
1230}
1231
1232static struct packet_type mctp_packet_type = {
1233 .type = cpu_to_be16(ETH_P_MCTP),
1234 .func = mctp_pkttype_receive,
1235};
1236
1237/* netlink interface */
1238
1239static const struct nla_policy rta_mctp_policy[RTA_MAX + 1] = {
1240 [RTA_DST] = { .type = NLA_U8 },
1241 [RTA_METRICS] = { .type = NLA_NESTED },
1242 [RTA_OIF] = { .type = NLA_U32 },
1243};
1244
1245/* Common part for RTM_NEWROUTE and RTM_DELROUTE parsing.
1246 * tb must hold RTA_MAX+1 elements.
1247 */
1248static int mctp_route_nlparse(struct sk_buff *skb, struct nlmsghdr *nlh,
1249 struct netlink_ext_ack *extack,
1250 struct nlattr **tb, struct rtmsg **rtm,
1251 struct mctp_dev **mdev, mctp_eid_t *daddr_start)
1252{
1253 struct net *net = sock_net(skb->sk);
1254 struct net_device *dev;
1255 unsigned int ifindex;
1256 int rc;
1257
1258 rc = nlmsg_parse(nlh, sizeof(struct rtmsg), tb, RTA_MAX,
1259 rta_mctp_policy, extack);
1260 if (rc < 0) {
1261 NL_SET_ERR_MSG(extack, "incorrect format");
1262 return rc;
1263 }
1264
1265 if (!tb[RTA_DST]) {
1266 NL_SET_ERR_MSG(extack, "dst EID missing");
1267 return -EINVAL;
1268 }
1269 *daddr_start = nla_get_u8(tb[RTA_DST]);
1270
1271 if (!tb[RTA_OIF]) {
1272 NL_SET_ERR_MSG(extack, "ifindex missing");
1273 return -EINVAL;
1274 }
1275 ifindex = nla_get_u32(tb[RTA_OIF]);
1276
1277 *rtm = nlmsg_data(nlh);
1278 if ((*rtm)->rtm_family != AF_MCTP) {
1279 NL_SET_ERR_MSG(extack, "route family must be AF_MCTP");
1280 return -EINVAL;
1281 }
1282
1283 dev = __dev_get_by_index(net, ifindex);
1284 if (!dev) {
1285 NL_SET_ERR_MSG(extack, "bad ifindex");
1286 return -ENODEV;
1287 }
1288 *mdev = mctp_dev_get_rtnl(dev);
1289 if (!*mdev)
1290 return -ENODEV;
1291
1292 if (dev->flags & IFF_LOOPBACK) {
1293 NL_SET_ERR_MSG(extack, "no routes to loopback");
1294 return -EINVAL;
1295 }
1296
1297 return 0;
1298}
1299
1300static const struct nla_policy rta_metrics_policy[RTAX_MAX + 1] = {
1301 [RTAX_MTU] = { .type = NLA_U32 },
1302};
1303
1304static int mctp_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
1305 struct netlink_ext_ack *extack)
1306{
1307 struct nlattr *tb[RTA_MAX + 1];
1308 struct nlattr *tbx[RTAX_MAX + 1];
1309 mctp_eid_t daddr_start;
1310 struct mctp_dev *mdev;
1311 struct rtmsg *rtm;
1312 unsigned int mtu;
1313 int rc;
1314
1315 rc = mctp_route_nlparse(skb, nlh, extack, tb,
1316 &rtm, &mdev, &daddr_start);
1317 if (rc < 0)
1318 return rc;
1319
1320 if (rtm->rtm_type != RTN_UNICAST) {
1321 NL_SET_ERR_MSG(extack, "rtm_type must be RTN_UNICAST");
1322 return -EINVAL;
1323 }
1324
1325 mtu = 0;
1326 if (tb[RTA_METRICS]) {
1327 rc = nla_parse_nested(tbx, RTAX_MAX, tb[RTA_METRICS],
1328 rta_metrics_policy, NULL);
1329 if (rc < 0)
1330 return rc;
1331 if (tbx[RTAX_MTU])
1332 mtu = nla_get_u32(tbx[RTAX_MTU]);
1333 }
1334
1335 rc = mctp_route_add(mdev, daddr_start, rtm->rtm_dst_len, mtu,
1336 rtm->rtm_type);
1337 return rc;
1338}
1339
1340static int mctp_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
1341 struct netlink_ext_ack *extack)
1342{
1343 struct nlattr *tb[RTA_MAX + 1];
1344 mctp_eid_t daddr_start;
1345 struct mctp_dev *mdev;
1346 struct rtmsg *rtm;
1347 int rc;
1348
1349 rc = mctp_route_nlparse(skb, nlh, extack, tb,
1350 &rtm, &mdev, &daddr_start);
1351 if (rc < 0)
1352 return rc;
1353
1354 /* we only have unicast routes */
1355 if (rtm->rtm_type != RTN_UNICAST)
1356 return -EINVAL;
1357
1358 rc = mctp_route_remove(mdev, daddr_start, rtm->rtm_dst_len, RTN_UNICAST);
1359 return rc;
1360}
1361
1362static int mctp_fill_rtinfo(struct sk_buff *skb, struct mctp_route *rt,
1363 u32 portid, u32 seq, int event, unsigned int flags)
1364{
1365 struct nlmsghdr *nlh;
1366 struct rtmsg *hdr;
1367 void *metrics;
1368
1369 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*hdr), flags);
1370 if (!nlh)
1371 return -EMSGSIZE;
1372
1373 hdr = nlmsg_data(nlh);
1374 hdr->rtm_family = AF_MCTP;
1375
1376 /* we use the _len fields as a number of EIDs, rather than
1377 * a number of bits in the address
1378 */
1379 hdr->rtm_dst_len = rt->max - rt->min;
1380 hdr->rtm_src_len = 0;
1381 hdr->rtm_tos = 0;
1382 hdr->rtm_table = RT_TABLE_DEFAULT;
1383 hdr->rtm_protocol = RTPROT_STATIC; /* everything is user-defined */
1384 hdr->rtm_scope = RT_SCOPE_LINK; /* TODO: scope in mctp_route? */
1385 hdr->rtm_type = rt->type;
1386
1387 if (nla_put_u8(skb, RTA_DST, rt->min))
1388 goto cancel;
1389
1390 metrics = nla_nest_start_noflag(skb, RTA_METRICS);
1391 if (!metrics)
1392 goto cancel;
1393
1394 if (rt->mtu) {
1395 if (nla_put_u32(skb, RTAX_MTU, rt->mtu))
1396 goto cancel;
1397 }
1398
1399 nla_nest_end(skb, metrics);
1400
1401 if (rt->dev) {
1402 if (nla_put_u32(skb, RTA_OIF, rt->dev->dev->ifindex))
1403 goto cancel;
1404 }
1405
1406 /* TODO: conditional neighbour physaddr? */
1407
1408 nlmsg_end(skb, nlh);
1409
1410 return 0;
1411
1412cancel:
1413 nlmsg_cancel(skb, nlh);
1414 return -EMSGSIZE;
1415}
1416
1417static int mctp_dump_rtinfo(struct sk_buff *skb, struct netlink_callback *cb)
1418{
1419 struct net *net = sock_net(skb->sk);
1420 struct mctp_route *rt;
1421 int s_idx, idx;
1422
1423 /* TODO: allow filtering on route data, possibly under
1424 * cb->strict_check
1425 */
1426
1427 /* TODO: change to struct overlay */
1428 s_idx = cb->args[0];
1429 idx = 0;
1430
1431 rcu_read_lock();
1432 list_for_each_entry_rcu(rt, &net->mctp.routes, list) {
1433 if (idx++ < s_idx)
1434 continue;
1435 if (mctp_fill_rtinfo(skb, rt,
1436 NETLINK_CB(cb->skb).portid,
1437 cb->nlh->nlmsg_seq,
1438 RTM_NEWROUTE, NLM_F_MULTI) < 0)
1439 break;
1440 }
1441
1442 rcu_read_unlock();
1443 cb->args[0] = idx;
1444
1445 return skb->len;
1446}
1447
1448/* net namespace implementation */
1449static int __net_init mctp_routes_net_init(struct net *net)
1450{
1451 struct netns_mctp *ns = &net->mctp;
1452
1453 INIT_LIST_HEAD(&ns->routes);
1454 INIT_HLIST_HEAD(&ns->binds);
1455 mutex_init(&ns->bind_lock);
1456 INIT_HLIST_HEAD(&ns->keys);
1457 spin_lock_init(&ns->keys_lock);
1458 WARN_ON(mctp_default_net_set(net, MCTP_INITIAL_DEFAULT_NET));
1459 return 0;
1460}
1461
1462static void __net_exit mctp_routes_net_exit(struct net *net)
1463{
1464 struct mctp_route *rt;
1465
1466 rcu_read_lock();
1467 list_for_each_entry_rcu(rt, &net->mctp.routes, list)
1468 mctp_route_release(rt);
1469 rcu_read_unlock();
1470}
1471
1472static struct pernet_operations mctp_net_ops = {
1473 .init = mctp_routes_net_init,
1474 .exit = mctp_routes_net_exit,
1475};
1476
1477int __init mctp_routes_init(void)
1478{
1479 dev_add_pack(&mctp_packet_type);
1480
1481 rtnl_register_module(THIS_MODULE, PF_MCTP, RTM_GETROUTE,
1482 NULL, mctp_dump_rtinfo, 0);
1483 rtnl_register_module(THIS_MODULE, PF_MCTP, RTM_NEWROUTE,
1484 mctp_newroute, NULL, 0);
1485 rtnl_register_module(THIS_MODULE, PF_MCTP, RTM_DELROUTE,
1486 mctp_delroute, NULL, 0);
1487
1488 return register_pernet_subsys(&mctp_net_ops);
1489}
1490
1491void mctp_routes_exit(void)
1492{
1493 unregister_pernet_subsys(&mctp_net_ops);
1494 rtnl_unregister(PF_MCTP, RTM_DELROUTE);
1495 rtnl_unregister(PF_MCTP, RTM_NEWROUTE);
1496 rtnl_unregister(PF_MCTP, RTM_GETROUTE);
1497 dev_remove_pack(&mctp_packet_type);
1498}
1499
1500#if IS_ENABLED(CONFIG_MCTP_TEST)
1501#include "test/route-test.c"
1502#endif