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Linux 4.1.16
[linux/fpc-iii.git] / net / mpls / af_mpls.c
blob1f93a5978f2ad43fc81a16427e34d07ca2c0f34e
1 #include <linux/types.h>
2 #include <linux/skbuff.h>
3 #include <linux/socket.h>
4 #include <linux/sysctl.h>
5 #include <linux/net.h>
6 #include <linux/module.h>
7 #include <linux/if_arp.h>
8 #include <linux/ipv6.h>
9 #include <linux/mpls.h>
10 #include <linux/vmalloc.h>
11 #include <net/ip.h>
12 #include <net/dst.h>
13 #include <net/sock.h>
14 #include <net/arp.h>
15 #include <net/ip_fib.h>
16 #include <net/netevent.h>
17 #include <net/netns/generic.h>
18 #include "internal.h"
19
20 #define LABEL_NOT_SPECIFIED (1<<20)
21 #define MAX_NEW_LABELS 2
22
23 /* This maximum ha length copied from the definition of struct neighbour */
24 #define MAX_VIA_ALEN (ALIGN(MAX_ADDR_LEN, sizeof(unsigned long)))
25
26 struct mpls_route { /* next hop label forwarding entry */
27 struct net_device __rcu *rt_dev;
28 struct rcu_head rt_rcu;
29 u32 rt_label[MAX_NEW_LABELS];
30 u8 rt_protocol; /* routing protocol that set this entry */
31 u8 rt_labels;
32 u8 rt_via_alen;
33 u8 rt_via_table;
34 u8 rt_via[0];
35 };
36
37 static int zero = 0;
38 static int label_limit = (1 << 20) - 1;
39
40 static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt,
41 struct nlmsghdr *nlh, struct net *net, u32 portid,
42 unsigned int nlm_flags);
43
44 static struct mpls_route *mpls_route_input_rcu(struct net *net, unsigned index)
45 {
46 struct mpls_route *rt = NULL;
47
48 if (index < net->mpls.platform_labels) {
49 struct mpls_route __rcu **platform_label =
50 rcu_dereference(net->mpls.platform_label);
51 rt = rcu_dereference(platform_label[index]);
52 }
53 return rt;
54 }
55
56 static inline struct mpls_dev *mpls_dev_get(const struct net_device *dev)
57 {
58 return rcu_dereference_rtnl(dev->mpls_ptr);
59 }
60
61 static bool mpls_output_possible(const struct net_device *dev)
62 {
63 return dev && (dev->flags & IFF_UP) && netif_carrier_ok(dev);
64 }
65
66 static unsigned int mpls_rt_header_size(const struct mpls_route *rt)
67 {
68 /* The size of the layer 2.5 labels to be added for this route */
69 return rt->rt_labels * sizeof(struct mpls_shim_hdr);
70 }
71
72 static unsigned int mpls_dev_mtu(const struct net_device *dev)
73 {
74 /* The amount of data the layer 2 frame can hold */
75 return dev->mtu;
76 }
77
78 static bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu)
79 {
80 if (skb->len <= mtu)
81 return false;
82
83 if (skb_is_gso(skb) && skb_gso_network_seglen(skb) <= mtu)
84 return false;
85
86 return true;
87 }
88
89 static bool mpls_egress(struct mpls_route *rt, struct sk_buff *skb,
90 struct mpls_entry_decoded dec)
91 {
92 /* RFC4385 and RFC5586 encode other packets in mpls such that
93 * they don't conflict with the ip version number, making
94 * decoding by examining the ip version correct in everything
95 * except for the strangest cases.
96 *
97 * The strange cases if we choose to support them will require
98 * manual configuration.
99 */
100 struct iphdr *hdr4;
101 bool success = true;
102
103 /* The IPv4 code below accesses through the IPv4 header
104 * checksum, which is 12 bytes into the packet.
105 * The IPv6 code below accesses through the IPv6 hop limit
106 * which is 8 bytes into the packet.
107 *
108 * For all supported cases there should always be at least 12
109 * bytes of packet data present. The IPv4 header is 20 bytes
110 * without options and the IPv6 header is always 40 bytes
111 * long.
112 */
113 if (!pskb_may_pull(skb, 12))
114 return false;
115
116 /* Use ip_hdr to find the ip protocol version */
117 hdr4 = ip_hdr(skb);
118 if (hdr4->version == 4) {
119 skb->protocol = htons(ETH_P_IP);
120 csum_replace2(&hdr4->check,
121 htons(hdr4->ttl << 8),
122 htons(dec.ttl << 8));
123 hdr4->ttl = dec.ttl;
124 }
125 else if (hdr4->version == 6) {
126 struct ipv6hdr *hdr6 = ipv6_hdr(skb);
127 skb->protocol = htons(ETH_P_IPV6);
128 hdr6->hop_limit = dec.ttl;
129 }
130 else
131 /* version 0 and version 1 are used by pseudo wires */
132 success = false;
133 return success;
134 }
135
136 static int mpls_forward(struct sk_buff *skb, struct net_device *dev,
137 struct packet_type *pt, struct net_device *orig_dev)
138 {
139 struct net *net = dev_net(dev);
140 struct mpls_shim_hdr *hdr;
141 struct mpls_route *rt;
142 struct mpls_entry_decoded dec;
143 struct net_device *out_dev;
144 struct mpls_dev *mdev;
145 unsigned int hh_len;
146 unsigned int new_header_size;
147 unsigned int mtu;
148 int err;
149
150 /* Careful this entire function runs inside of an rcu critical section */
151
152 mdev = mpls_dev_get(dev);
153 if (!mdev || !mdev->input_enabled)
154 goto drop;
155
156 if (skb->pkt_type != PACKET_HOST)
157 goto drop;
158
159 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
160 goto drop;
161
162 if (!pskb_may_pull(skb, sizeof(*hdr)))
163 goto drop;
164
165 /* Read and decode the label */
166 hdr = mpls_hdr(skb);
167 dec = mpls_entry_decode(hdr);
168
169 /* Pop the label */
170 skb_pull(skb, sizeof(*hdr));
171 skb_reset_network_header(skb);
172
173 skb_orphan(skb);
174
175 rt = mpls_route_input_rcu(net, dec.label);
176 if (!rt)
177 goto drop;
178
179 /* Find the output device */
180 out_dev = rcu_dereference(rt->rt_dev);
181 if (!mpls_output_possible(out_dev))
182 goto drop;
183
184 if (skb_warn_if_lro(skb))
185 goto drop;
186
187 skb_forward_csum(skb);
188
189 /* Verify ttl is valid */
190 if (dec.ttl <= 1)
191 goto drop;
192 dec.ttl -= 1;
193
194 /* Verify the destination can hold the packet */
195 new_header_size = mpls_rt_header_size(rt);
196 mtu = mpls_dev_mtu(out_dev);
197 if (mpls_pkt_too_big(skb, mtu - new_header_size))
198 goto drop;
199
200 hh_len = LL_RESERVED_SPACE(out_dev);
201 if (!out_dev->header_ops)
202 hh_len = 0;
203
204 /* Ensure there is enough space for the headers in the skb */
205 if (skb_cow(skb, hh_len + new_header_size))
206 goto drop;
207
208 skb->dev = out_dev;
209 skb->protocol = htons(ETH_P_MPLS_UC);
210
211 if (unlikely(!new_header_size && dec.bos)) {
212 /* Penultimate hop popping */
213 if (!mpls_egress(rt, skb, dec))
214 goto drop;
215 } else {
216 bool bos;
217 int i;
218 skb_push(skb, new_header_size);
219 skb_reset_network_header(skb);
220 /* Push the new labels */
221 hdr = mpls_hdr(skb);
222 bos = dec.bos;
223 for (i = rt->rt_labels - 1; i >= 0; i--) {
224 hdr[i] = mpls_entry_encode(rt->rt_label[i], dec.ttl, 0, bos);
225 bos = false;
226 }
227 }
228
229 err = neigh_xmit(rt->rt_via_table, out_dev, rt->rt_via, skb);
230 if (err)
231 net_dbg_ratelimited("%s: packet transmission failed: %d\n",
232 __func__, err);
233 return 0;
234
235 drop:
236 kfree_skb(skb);
237 return NET_RX_DROP;
238 }
239
240 static struct packet_type mpls_packet_type __read_mostly = {
241 .type = cpu_to_be16(ETH_P_MPLS_UC),
242 .func = mpls_forward,
243 };
244
245 static const struct nla_policy rtm_mpls_policy[RTA_MAX+1] = {
246 [RTA_DST] = { .type = NLA_U32 },
247 [RTA_OIF] = { .type = NLA_U32 },
248 };
249
250 struct mpls_route_config {
251 u32 rc_protocol;
252 u32 rc_ifindex;
253 u16 rc_via_table;
254 u16 rc_via_alen;
255 u8 rc_via[MAX_VIA_ALEN];
256 u32 rc_label;
257 u32 rc_output_labels;
258 u32 rc_output_label[MAX_NEW_LABELS];
259 u32 rc_nlflags;
260 struct nl_info rc_nlinfo;
261 };
262
263 static struct mpls_route *mpls_rt_alloc(size_t alen)
264 {
265 struct mpls_route *rt;
266
267 rt = kzalloc(sizeof(*rt) + alen, GFP_KERNEL);
268 if (rt)
269 rt->rt_via_alen = alen;
270 return rt;
271 }
272
273 static void mpls_rt_free(struct mpls_route *rt)
274 {
275 if (rt)
276 kfree_rcu(rt, rt_rcu);
277 }
278
279 static void mpls_notify_route(struct net *net, unsigned index,
280 struct mpls_route *old, struct mpls_route *new,
281 const struct nl_info *info)
282 {
283 struct nlmsghdr *nlh = info ? info->nlh : NULL;
284 unsigned portid = info ? info->portid : 0;
285 int event = new ? RTM_NEWROUTE : RTM_DELROUTE;
286 struct mpls_route *rt = new ? new : old;
287 unsigned nlm_flags = (old && new) ? NLM_F_REPLACE : 0;
288 /* Ignore reserved labels for now */
289 if (rt && (index >= 16))
290 rtmsg_lfib(event, index, rt, nlh, net, portid, nlm_flags);
291 }
292
293 static void mpls_route_update(struct net *net, unsigned index,
294 struct net_device *dev, struct mpls_route *new,
295 const struct nl_info *info)
296 {
297 struct mpls_route __rcu **platform_label;
298 struct mpls_route *rt, *old = NULL;
299
300 ASSERT_RTNL();
301
302 platform_label = rtnl_dereference(net->mpls.platform_label);
303 rt = rtnl_dereference(platform_label[index]);
304 if (!dev || (rt && (rtnl_dereference(rt->rt_dev) == dev))) {
305 rcu_assign_pointer(platform_label[index], new);
306 old = rt;
307 }
308
309 mpls_notify_route(net, index, old, new, info);
310
311 /* If we removed a route free it now */
312 mpls_rt_free(old);
313 }
314
315 static unsigned find_free_label(struct net *net)
316 {
317 struct mpls_route __rcu **platform_label;
318 size_t platform_labels;
319 unsigned index;
320
321 platform_label = rtnl_dereference(net->mpls.platform_label);
322 platform_labels = net->mpls.platform_labels;
323 for (index = 16; index < platform_labels; index++) {
324 if (!rtnl_dereference(platform_label[index]))
325 return index;
326 }
327 return LABEL_NOT_SPECIFIED;
328 }
329
330 static int mpls_route_add(struct mpls_route_config *cfg)
331 {
332 struct mpls_route __rcu **platform_label;
333 struct net *net = cfg->rc_nlinfo.nl_net;
334 struct net_device *dev = NULL;
335 struct mpls_route *rt, *old;
336 unsigned index;
337 int i;
338 int err = -EINVAL;
339
340 index = cfg->rc_label;
341
342 /* If a label was not specified during insert pick one */
343 if ((index == LABEL_NOT_SPECIFIED) &&
344 (cfg->rc_nlflags & NLM_F_CREATE)) {
345 index = find_free_label(net);
346 }
347
348 /* The first 16 labels are reserved, and may not be set */
349 if (index < 16)
350 goto errout;
351
352 /* The full 20 bit range may not be supported. */
353 if (index >= net->mpls.platform_labels)
354 goto errout;
355
356 /* Ensure only a supported number of labels are present */
357 if (cfg->rc_output_labels > MAX_NEW_LABELS)
358 goto errout;
359
360 err = -ENODEV;
361 dev = dev_get_by_index(net, cfg->rc_ifindex);
362 if (!dev)
363 goto errout;
364
365 /* Ensure this is a supported device */
366 err = -EINVAL;
367 if (!mpls_dev_get(dev))
368 goto errout;
369
370 err = -EINVAL;
371 if ((cfg->rc_via_table == NEIGH_LINK_TABLE) &&
372 (dev->addr_len != cfg->rc_via_alen))
373 goto errout;
374
375 /* Append makes no sense with mpls */
376 err = -EOPNOTSUPP;
377 if (cfg->rc_nlflags & NLM_F_APPEND)
378 goto errout;
379
380 err = -EEXIST;
381 platform_label = rtnl_dereference(net->mpls.platform_label);
382 old = rtnl_dereference(platform_label[index]);
383 if ((cfg->rc_nlflags & NLM_F_EXCL) && old)
384 goto errout;
385
386 err = -EEXIST;
387 if (!(cfg->rc_nlflags & NLM_F_REPLACE) && old)
388 goto errout;
389
390 err = -ENOENT;
391 if (!(cfg->rc_nlflags & NLM_F_CREATE) && !old)
392 goto errout;
393
394 err = -ENOMEM;
395 rt = mpls_rt_alloc(cfg->rc_via_alen);
396 if (!rt)
397 goto errout;
398
399 rt->rt_labels = cfg->rc_output_labels;
400 for (i = 0; i < rt->rt_labels; i++)
401 rt->rt_label[i] = cfg->rc_output_label[i];
402 rt->rt_protocol = cfg->rc_protocol;
403 RCU_INIT_POINTER(rt->rt_dev, dev);
404 rt->rt_via_table = cfg->rc_via_table;
405 memcpy(rt->rt_via, cfg->rc_via, cfg->rc_via_alen);
406
407 mpls_route_update(net, index, NULL, rt, &cfg->rc_nlinfo);
408
409 dev_put(dev);
410 return 0;
411
412 errout:
413 if (dev)
414 dev_put(dev);
415 return err;
416 }
417
418 static int mpls_route_del(struct mpls_route_config *cfg)
419 {
420 struct net *net = cfg->rc_nlinfo.nl_net;
421 unsigned index;
422 int err = -EINVAL;
423
424 index = cfg->rc_label;
425
426 /* The first 16 labels are reserved, and may not be removed */
427 if (index < 16)
428 goto errout;
429
430 /* The full 20 bit range may not be supported */
431 if (index >= net->mpls.platform_labels)
432 goto errout;
433
434 mpls_route_update(net, index, NULL, NULL, &cfg->rc_nlinfo);
435
436 err = 0;
437 errout:
438 return err;
439 }
440
441 #define MPLS_PERDEV_SYSCTL_OFFSET(field) \
442 (&((struct mpls_dev *)0)->field)
443
444 static const struct ctl_table mpls_dev_table[] = {
445 {
446 .procname = "input",
447 .maxlen = sizeof(int),
448 .mode = 0644,
449 .proc_handler = proc_dointvec,
450 .data = MPLS_PERDEV_SYSCTL_OFFSET(input_enabled),
451 },
452 { }
453 };
454
455 static int mpls_dev_sysctl_register(struct net_device *dev,
456 struct mpls_dev *mdev)
457 {
458 char path[sizeof("net/mpls/conf/") + IFNAMSIZ];
459 struct ctl_table *table;
460 int i;
461
462 table = kmemdup(&mpls_dev_table, sizeof(mpls_dev_table), GFP_KERNEL);
463 if (!table)
464 goto out;
465
466 /* Table data contains only offsets relative to the base of
467 * the mdev at this point, so make them absolute.
468 */
469 for (i = 0; i < ARRAY_SIZE(mpls_dev_table); i++)
470 table[i].data = (char *)mdev + (uintptr_t)table[i].data;
471
472 snprintf(path, sizeof(path), "net/mpls/conf/%s", dev->name);
473
474 mdev->sysctl = register_net_sysctl(dev_net(dev), path, table);
475 if (!mdev->sysctl)
476 goto free;
477
478 return 0;
479
480 free:
481 kfree(table);
482 out:
483 return -ENOBUFS;
484 }
485
486 static void mpls_dev_sysctl_unregister(struct mpls_dev *mdev)
487 {
488 struct ctl_table *table;
489
490 table = mdev->sysctl->ctl_table_arg;
491 unregister_net_sysctl_table(mdev->sysctl);
492 kfree(table);
493 }
494
495 static struct mpls_dev *mpls_add_dev(struct net_device *dev)
496 {
497 struct mpls_dev *mdev;
498 int err = -ENOMEM;
499
500 ASSERT_RTNL();
501
502 mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
503 if (!mdev)
504 return ERR_PTR(err);
505
506 err = mpls_dev_sysctl_register(dev, mdev);
507 if (err)
508 goto free;
509
510 rcu_assign_pointer(dev->mpls_ptr, mdev);
511
512 return mdev;
513
514 free:
515 kfree(mdev);
516 return ERR_PTR(err);
517 }
518
519 static void mpls_ifdown(struct net_device *dev)
520 {
521 struct mpls_route __rcu **platform_label;
522 struct net *net = dev_net(dev);
523 struct mpls_dev *mdev;
524 unsigned index;
525
526 platform_label = rtnl_dereference(net->mpls.platform_label);
527 for (index = 0; index < net->mpls.platform_labels; index++) {
528 struct mpls_route *rt = rtnl_dereference(platform_label[index]);
529 if (!rt)
530 continue;
531 if (rtnl_dereference(rt->rt_dev) != dev)
532 continue;
533 rt->rt_dev = NULL;
534 }
535
536 mdev = mpls_dev_get(dev);
537 if (!mdev)
538 return;
539
540 mpls_dev_sysctl_unregister(mdev);
541
542 RCU_INIT_POINTER(dev->mpls_ptr, NULL);
543
544 kfree_rcu(mdev, rcu);
545 }
546
547 static int mpls_dev_notify(struct notifier_block *this, unsigned long event,
548 void *ptr)
549 {
550 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
551 struct mpls_dev *mdev;
552
553 switch(event) {
554 case NETDEV_REGISTER:
555 /* For now just support ethernet devices */
556 if ((dev->type == ARPHRD_ETHER) ||
557 (dev->type == ARPHRD_LOOPBACK)) {
558 mdev = mpls_add_dev(dev);
559 if (IS_ERR(mdev))
560 return notifier_from_errno(PTR_ERR(mdev));
561 }
562 break;
563
564 case NETDEV_UNREGISTER:
565 mpls_ifdown(dev);
566 break;
567 case NETDEV_CHANGENAME:
568 mdev = mpls_dev_get(dev);
569 if (mdev) {
570 int err;
571
572 mpls_dev_sysctl_unregister(mdev);
573 err = mpls_dev_sysctl_register(dev, mdev);
574 if (err)
575 return notifier_from_errno(err);
576 }
577 break;
578 }
579 return NOTIFY_OK;
580 }
581
582 static struct notifier_block mpls_dev_notifier = {
583 .notifier_call = mpls_dev_notify,
584 };
585
586 static int nla_put_via(struct sk_buff *skb,
587 u8 table, const void *addr, int alen)
588 {
589 static const int table_to_family[NEIGH_NR_TABLES + 1] = {
590 AF_INET, AF_INET6, AF_DECnet, AF_PACKET,
591 };
592 struct nlattr *nla;
593 struct rtvia *via;
594 int family = AF_UNSPEC;
595
596 nla = nla_reserve(skb, RTA_VIA, alen + 2);
597 if (!nla)
598 return -EMSGSIZE;
599
600 if (table <= NEIGH_NR_TABLES)
601 family = table_to_family[table];
602
603 via = nla_data(nla);
604 via->rtvia_family = family;
605 memcpy(via->rtvia_addr, addr, alen);
606 return 0;
607 }
608
609 int nla_put_labels(struct sk_buff *skb, int attrtype,
610 u8 labels, const u32 label[])
611 {
612 struct nlattr *nla;
613 struct mpls_shim_hdr *nla_label;
614 bool bos;
615 int i;
616 nla = nla_reserve(skb, attrtype, labels*4);
617 if (!nla)
618 return -EMSGSIZE;
619
620 nla_label = nla_data(nla);
621 bos = true;
622 for (i = labels - 1; i >= 0; i--) {
623 nla_label[i] = mpls_entry_encode(label[i], 0, 0, bos);
624 bos = false;
625 }
626
627 return 0;
628 }
629
630 int nla_get_labels(const struct nlattr *nla,
631 u32 max_labels, u32 *labels, u32 label[])
632 {
633 unsigned len = nla_len(nla);
634 unsigned nla_labels;
635 struct mpls_shim_hdr *nla_label;
636 bool bos;
637 int i;
638
639 /* len needs to be an even multiple of 4 (the label size) */
640 if (len & 3)
641 return -EINVAL;
642
643 /* Limit the number of new labels allowed */
644 nla_labels = len/4;
645 if (nla_labels > max_labels)
646 return -EINVAL;
647
648 nla_label = nla_data(nla);
649 bos = true;
650 for (i = nla_labels - 1; i >= 0; i--, bos = false) {
651 struct mpls_entry_decoded dec;
652 dec = mpls_entry_decode(nla_label + i);
653
654 /* Ensure the bottom of stack flag is properly set
655 * and ttl and tc are both clear.
656 */
657 if ((dec.bos != bos) || dec.ttl || dec.tc)
658 return -EINVAL;
659
660 switch (dec.label) {
661 case MPLS_LABEL_IMPLNULL:
662 /* RFC3032: This is a label that an LSR may
663 * assign and distribute, but which never
664 * actually appears in the encapsulation.
665 */
666 return -EINVAL;
667 }
668
669 label[i] = dec.label;
670 }
671 *labels = nla_labels;
672 return 0;
673 }
674
675 static int rtm_to_route_config(struct sk_buff *skb, struct nlmsghdr *nlh,
676 struct mpls_route_config *cfg)
677 {
678 struct rtmsg *rtm;
679 struct nlattr *tb[RTA_MAX+1];
680 int index;
681 int err;
682
683 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_mpls_policy);
684 if (err < 0)
685 goto errout;
686
687 err = -EINVAL;
688 rtm = nlmsg_data(nlh);
689 memset(cfg, 0, sizeof(*cfg));
690
691 if (rtm->rtm_family != AF_MPLS)
692 goto errout;
693 if (rtm->rtm_dst_len != 20)
694 goto errout;
695 if (rtm->rtm_src_len != 0)
696 goto errout;
697 if (rtm->rtm_tos != 0)
698 goto errout;
699 if (rtm->rtm_table != RT_TABLE_MAIN)
700 goto errout;
701 /* Any value is acceptable for rtm_protocol */
702
703 /* As mpls uses destination specific addresses
704 * (or source specific address in the case of multicast)
705 * all addresses have universal scope.
706 */
707 if (rtm->rtm_scope != RT_SCOPE_UNIVERSE)
708 goto errout;
709 if (rtm->rtm_type != RTN_UNICAST)
710 goto errout;
711 if (rtm->rtm_flags != 0)
712 goto errout;
713
714 cfg->rc_label = LABEL_NOT_SPECIFIED;
715 cfg->rc_protocol = rtm->rtm_protocol;
716 cfg->rc_nlflags = nlh->nlmsg_flags;
717 cfg->rc_nlinfo.portid = NETLINK_CB(skb).portid;
718 cfg->rc_nlinfo.nlh = nlh;
719 cfg->rc_nlinfo.nl_net = sock_net(skb->sk);
720
721 for (index = 0; index <= RTA_MAX; index++) {
722 struct nlattr *nla = tb[index];
723 if (!nla)
724 continue;
725
726 switch(index) {
727 case RTA_OIF:
728 cfg->rc_ifindex = nla_get_u32(nla);
729 break;
730 case RTA_NEWDST:
731 if (nla_get_labels(nla, MAX_NEW_LABELS,
732 &cfg->rc_output_labels,
733 cfg->rc_output_label))
734 goto errout;
735 break;
736 case RTA_DST:
737 {
738 u32 label_count;
739 if (nla_get_labels(nla, 1, &label_count,
740 &cfg->rc_label))
741 goto errout;
742
743 /* The first 16 labels are reserved, and may not be set */
744 if (cfg->rc_label < 16)
745 goto errout;
746
747 break;
748 }
749 case RTA_VIA:
750 {
751 struct rtvia *via = nla_data(nla);
752 if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr))
753 goto errout;
754 cfg->rc_via_alen = nla_len(nla) -
755 offsetof(struct rtvia, rtvia_addr);
756 if (cfg->rc_via_alen > MAX_VIA_ALEN)
757 goto errout;
758
759 /* Validate the address family */
760 switch(via->rtvia_family) {
761 case AF_PACKET:
762 cfg->rc_via_table = NEIGH_LINK_TABLE;
763 break;
764 case AF_INET:
765 cfg->rc_via_table = NEIGH_ARP_TABLE;
766 if (cfg->rc_via_alen != 4)
767 goto errout;
768 break;
769 case AF_INET6:
770 cfg->rc_via_table = NEIGH_ND_TABLE;
771 if (cfg->rc_via_alen != 16)
772 goto errout;
773 break;
774 default:
775 /* Unsupported address family */
776 goto errout;
777 }
778
779 memcpy(cfg->rc_via, via->rtvia_addr, cfg->rc_via_alen);
780 break;
781 }
782 default:
783 /* Unsupported attribute */
784 goto errout;
785 }
786 }
787
788 err = 0;
789 errout:
790 return err;
791 }
792
793 static int mpls_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh)
794 {
795 struct mpls_route_config cfg;
796 int err;
797
798 err = rtm_to_route_config(skb, nlh, &cfg);
799 if (err < 0)
800 return err;
801
802 return mpls_route_del(&cfg);
803 }
804
805
806 static int mpls_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh)
807 {
808 struct mpls_route_config cfg;
809 int err;
810
811 err = rtm_to_route_config(skb, nlh, &cfg);
812 if (err < 0)
813 return err;
814
815 return mpls_route_add(&cfg);
816 }
817
818 static int mpls_dump_route(struct sk_buff *skb, u32 portid, u32 seq, int event,
819 u32 label, struct mpls_route *rt, int flags)
820 {
821 struct net_device *dev;
822 struct nlmsghdr *nlh;
823 struct rtmsg *rtm;
824
825 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), flags);
826 if (nlh == NULL)
827 return -EMSGSIZE;
828
829 rtm = nlmsg_data(nlh);
830 rtm->rtm_family = AF_MPLS;
831 rtm->rtm_dst_len = 20;
832 rtm->rtm_src_len = 0;
833 rtm->rtm_tos = 0;
834 rtm->rtm_table = RT_TABLE_MAIN;
835 rtm->rtm_protocol = rt->rt_protocol;
836 rtm->rtm_scope = RT_SCOPE_UNIVERSE;
837 rtm->rtm_type = RTN_UNICAST;
838 rtm->rtm_flags = 0;
839
840 if (rt->rt_labels &&
841 nla_put_labels(skb, RTA_NEWDST, rt->rt_labels, rt->rt_label))
842 goto nla_put_failure;
843 if (nla_put_via(skb, rt->rt_via_table, rt->rt_via, rt->rt_via_alen))
844 goto nla_put_failure;
845 dev = rtnl_dereference(rt->rt_dev);
846 if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex))
847 goto nla_put_failure;
848 if (nla_put_labels(skb, RTA_DST, 1, &label))
849 goto nla_put_failure;
850
851 nlmsg_end(skb, nlh);
852 return 0;
853
854 nla_put_failure:
855 nlmsg_cancel(skb, nlh);
856 return -EMSGSIZE;
857 }
858
859 static int mpls_dump_routes(struct sk_buff *skb, struct netlink_callback *cb)
860 {
861 struct net *net = sock_net(skb->sk);
862 struct mpls_route __rcu **platform_label;
863 size_t platform_labels;
864 unsigned int index;
865
866 ASSERT_RTNL();
867
868 index = cb->args[0];
869 if (index < 16)
870 index = 16;
871
872 platform_label = rtnl_dereference(net->mpls.platform_label);
873 platform_labels = net->mpls.platform_labels;
874 for (; index < platform_labels; index++) {
875 struct mpls_route *rt;
876 rt = rtnl_dereference(platform_label[index]);
877 if (!rt)
878 continue;
879
880 if (mpls_dump_route(skb, NETLINK_CB(cb->skb).portid,
881 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
882 index, rt, NLM_F_MULTI) < 0)
883 break;
884 }
885 cb->args[0] = index;
886
887 return skb->len;
888 }
889
890 static inline size_t lfib_nlmsg_size(struct mpls_route *rt)
891 {
892 size_t payload =
893 NLMSG_ALIGN(sizeof(struct rtmsg))
894 + nla_total_size(2 + rt->rt_via_alen) /* RTA_VIA */
895 + nla_total_size(4); /* RTA_DST */
896 if (rt->rt_labels) /* RTA_NEWDST */
897 payload += nla_total_size(rt->rt_labels * 4);
898 if (rt->rt_dev) /* RTA_OIF */
899 payload += nla_total_size(4);
900 return payload;
901 }
902
903 static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt,
904 struct nlmsghdr *nlh, struct net *net, u32 portid,
905 unsigned int nlm_flags)
906 {
907 struct sk_buff *skb;
908 u32 seq = nlh ? nlh->nlmsg_seq : 0;
909 int err = -ENOBUFS;
910
911 skb = nlmsg_new(lfib_nlmsg_size(rt), GFP_KERNEL);
912 if (skb == NULL)
913 goto errout;
914
915 err = mpls_dump_route(skb, portid, seq, event, label, rt, nlm_flags);
916 if (err < 0) {
917 /* -EMSGSIZE implies BUG in lfib_nlmsg_size */
918 WARN_ON(err == -EMSGSIZE);
919 kfree_skb(skb);
920 goto errout;
921 }
922 rtnl_notify(skb, net, portid, RTNLGRP_MPLS_ROUTE, nlh, GFP_KERNEL);
923
924 return;
925 errout:
926 if (err < 0)
927 rtnl_set_sk_err(net, RTNLGRP_MPLS_ROUTE, err);
928 }
929
930 static int resize_platform_label_table(struct net *net, size_t limit)
931 {
932 size_t size = sizeof(struct mpls_route *) * limit;
933 size_t old_limit;
934 size_t cp_size;
935 struct mpls_route __rcu **labels = NULL, **old;
936 struct mpls_route *rt0 = NULL, *rt2 = NULL;
937 unsigned index;
938
939 if (size) {
940 labels = kzalloc(size, GFP_KERNEL | __GFP_NOWARN | __GFP_NORETRY);
941 if (!labels)
942 labels = vzalloc(size);
943
944 if (!labels)
945 goto nolabels;
946 }
947
948 /* In case the predefined labels need to be populated */
949 if (limit > MPLS_LABEL_IPV4NULL) {
950 struct net_device *lo = net->loopback_dev;
951 rt0 = mpls_rt_alloc(lo->addr_len);
952 if (!rt0)
953 goto nort0;
954 RCU_INIT_POINTER(rt0->rt_dev, lo);
955 rt0->rt_protocol = RTPROT_KERNEL;
956 rt0->rt_via_table = NEIGH_LINK_TABLE;
957 memcpy(rt0->rt_via, lo->dev_addr, lo->addr_len);
958 }
959 if (limit > MPLS_LABEL_IPV6NULL) {
960 struct net_device *lo = net->loopback_dev;
961 rt2 = mpls_rt_alloc(lo->addr_len);
962 if (!rt2)
963 goto nort2;
964 RCU_INIT_POINTER(rt2->rt_dev, lo);
965 rt2->rt_protocol = RTPROT_KERNEL;
966 rt2->rt_via_table = NEIGH_LINK_TABLE;
967 memcpy(rt2->rt_via, lo->dev_addr, lo->addr_len);
968 }
969
970 rtnl_lock();
971 /* Remember the original table */
972 old = rtnl_dereference(net->mpls.platform_label);
973 old_limit = net->mpls.platform_labels;
974
975 /* Free any labels beyond the new table */
976 for (index = limit; index < old_limit; index++)
977 mpls_route_update(net, index, NULL, NULL, NULL);
978
979 /* Copy over the old labels */
980 cp_size = size;
981 if (old_limit < limit)
982 cp_size = old_limit * sizeof(struct mpls_route *);
983
984 memcpy(labels, old, cp_size);
985
986 /* If needed set the predefined labels */
987 if ((old_limit <= MPLS_LABEL_IPV6NULL) &&
988 (limit > MPLS_LABEL_IPV6NULL)) {
989 RCU_INIT_POINTER(labels[MPLS_LABEL_IPV6NULL], rt2);
990 rt2 = NULL;
991 }
992
993 if ((old_limit <= MPLS_LABEL_IPV4NULL) &&
994 (limit > MPLS_LABEL_IPV4NULL)) {
995 RCU_INIT_POINTER(labels[MPLS_LABEL_IPV4NULL], rt0);
996 rt0 = NULL;
997 }
998
999 /* Update the global pointers */
1000 net->mpls.platform_labels = limit;
1001 rcu_assign_pointer(net->mpls.platform_label, labels);
1002
1003 rtnl_unlock();
1004
1005 mpls_rt_free(rt2);
1006 mpls_rt_free(rt0);
1007
1008 if (old) {
1009 synchronize_rcu();
1010 kvfree(old);
1011 }
1012 return 0;
1013
1014 nort2:
1015 mpls_rt_free(rt0);
1016 nort0:
1017 kvfree(labels);
1018 nolabels:
1019 return -ENOMEM;
1020 }
1021
1022 static int mpls_platform_labels(struct ctl_table *table, int write,
1023 void __user *buffer, size_t *lenp, loff_t *ppos)
1024 {
1025 struct net *net = table->data;
1026 int platform_labels = net->mpls.platform_labels;
1027 int ret;
1028 struct ctl_table tmp = {
1029 .procname = table->procname,
1030 .data = &platform_labels,
1031 .maxlen = sizeof(int),
1032 .mode = table->mode,
1033 .extra1 = &zero,
1034 .extra2 = &label_limit,
1035 };
1036
1037 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
1038
1039 if (write && ret == 0)
1040 ret = resize_platform_label_table(net, platform_labels);
1041
1042 return ret;
1043 }
1044
1045 static const struct ctl_table mpls_table[] = {
1046 {
1047 .procname = "platform_labels",
1048 .data = NULL,
1049 .maxlen = sizeof(int),
1050 .mode = 0644,
1051 .proc_handler = mpls_platform_labels,
1052 },
1053 { }
1054 };
1055
1056 static int mpls_net_init(struct net *net)
1057 {
1058 struct ctl_table *table;
1059
1060 net->mpls.platform_labels = 0;
1061 net->mpls.platform_label = NULL;
1062
1063 table = kmemdup(mpls_table, sizeof(mpls_table), GFP_KERNEL);
1064 if (table == NULL)
1065 return -ENOMEM;
1066
1067 table[0].data = net;
1068 net->mpls.ctl = register_net_sysctl(net, "net/mpls", table);
1069 if (net->mpls.ctl == NULL)
1070 return -ENOMEM;
1071
1072 return 0;
1073 }
1074
1075 static void mpls_net_exit(struct net *net)
1076 {
1077 struct mpls_route __rcu **platform_label;
1078 size_t platform_labels;
1079 struct ctl_table *table;
1080 unsigned int index;
1081
1082 table = net->mpls.ctl->ctl_table_arg;
1083 unregister_net_sysctl_table(net->mpls.ctl);
1084 kfree(table);
1085
1086 /* An rcu grace period has passed since there was a device in
1087 * the network namespace (and thus the last in flight packet)
1088 * left this network namespace. This is because
1089 * unregister_netdevice_many and netdev_run_todo has completed
1090 * for each network device that was in this network namespace.
1091 *
1092 * As such no additional rcu synchronization is necessary when
1093 * freeing the platform_label table.
1094 */
1095 rtnl_lock();
1096 platform_label = rtnl_dereference(net->mpls.platform_label);
1097 platform_labels = net->mpls.platform_labels;
1098 for (index = 0; index < platform_labels; index++) {
1099 struct mpls_route *rt = rtnl_dereference(platform_label[index]);
1100 RCU_INIT_POINTER(platform_label[index], NULL);
1101 mpls_rt_free(rt);
1102 }
1103 rtnl_unlock();
1104
1105 kvfree(platform_label);
1106 }
1107
1108 static struct pernet_operations mpls_net_ops = {
1109 .init = mpls_net_init,
1110 .exit = mpls_net_exit,
1111 };
1112
1113 static int __init mpls_init(void)
1114 {
1115 int err;
1116
1117 BUILD_BUG_ON(sizeof(struct mpls_shim_hdr) != 4);
1118
1119 err = register_pernet_subsys(&mpls_net_ops);
1120 if (err)
1121 goto out;
1122
1123 err = register_netdevice_notifier(&mpls_dev_notifier);
1124 if (err)
1125 goto out_unregister_pernet;
1126
1127 dev_add_pack(&mpls_packet_type);
1128
1129 rtnl_register(PF_MPLS, RTM_NEWROUTE, mpls_rtm_newroute, NULL, NULL);
1130 rtnl_register(PF_MPLS, RTM_DELROUTE, mpls_rtm_delroute, NULL, NULL);
1131 rtnl_register(PF_MPLS, RTM_GETROUTE, NULL, mpls_dump_routes, NULL);
1132 err = 0;
1133 out:
1134 return err;
1135
1136 out_unregister_pernet:
1137 unregister_pernet_subsys(&mpls_net_ops);
1138 goto out;
1139 }
1140 module_init(mpls_init);
1141
1142 static void __exit mpls_exit(void)
1143 {
1144 rtnl_unregister_all(PF_MPLS);
1145 dev_remove_pack(&mpls_packet_type);
1146 unregister_netdevice_notifier(&mpls_dev_notifier);
1147 unregister_pernet_subsys(&mpls_net_ops);
1148 }
1149 module_exit(mpls_exit);
1150
1151 MODULE_DESCRIPTION("MultiProtocol Label Switching");
1152 MODULE_LICENSE("GPL v2");
1153 MODULE_ALIAS_NETPROTO(PF_MPLS);
Linux with added FPC-III support