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Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/ide
[mirror_ubuntu-bionic-kernel.git] / net / mpls / af_mpls.c
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/netconf.h>
11 #include <linux/vmalloc.h>
12 #include <linux/percpu.h>
13 #include <net/ip.h>
14 #include <net/dst.h>
15 #include <net/sock.h>
16 #include <net/arp.h>
17 #include <net/ip_fib.h>
18 #include <net/netevent.h>
19 #include <net/ip_tunnels.h>
20 #include <net/netns/generic.h>
21 #if IS_ENABLED(CONFIG_IPV6)
22 #include <net/ipv6.h>
23 #endif
24 #include <net/addrconf.h>
25 #include <net/nexthop.h>
26 #include "internal.h"
27
28 /* max memory we will use for mpls_route */
29 #define MAX_MPLS_ROUTE_MEM 4096
30
31 /* Maximum number of labels to look ahead at when selecting a path of
32 * a multipath route
33 */
34 #define MAX_MP_SELECT_LABELS 4
35
36 #define MPLS_NEIGH_TABLE_UNSPEC (NEIGH_LINK_TABLE + 1)
37
38 static int zero = 0;
39 static int one = 1;
40 static int label_limit = (1 << 20) - 1;
41 static int ttl_max = 255;
42
43 #if IS_ENABLED(CONFIG_NET_IP_TUNNEL)
44 static size_t ipgre_mpls_encap_hlen(struct ip_tunnel_encap *e)
45 {
46 return sizeof(struct mpls_shim_hdr);
47 }
48
49 static const struct ip_tunnel_encap_ops mpls_iptun_ops = {
50 .encap_hlen = ipgre_mpls_encap_hlen,
51 };
52
53 static int ipgre_tunnel_encap_add_mpls_ops(void)
54 {
55 return ip_tunnel_encap_add_ops(&mpls_iptun_ops, TUNNEL_ENCAP_MPLS);
56 }
57
58 static void ipgre_tunnel_encap_del_mpls_ops(void)
59 {
60 ip_tunnel_encap_del_ops(&mpls_iptun_ops, TUNNEL_ENCAP_MPLS);
61 }
62 #else
63 static int ipgre_tunnel_encap_add_mpls_ops(void)
64 {
65 return 0;
66 }
67
68 static void ipgre_tunnel_encap_del_mpls_ops(void)
69 {
70 }
71 #endif
72
73 static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt,
74 struct nlmsghdr *nlh, struct net *net, u32 portid,
75 unsigned int nlm_flags);
76
77 static struct mpls_route *mpls_route_input_rcu(struct net *net, unsigned index)
78 {
79 struct mpls_route *rt = NULL;
80
81 if (index < net->mpls.platform_labels) {
82 struct mpls_route __rcu **platform_label =
83 rcu_dereference(net->mpls.platform_label);
84 rt = rcu_dereference(platform_label[index]);
85 }
86 return rt;
87 }
88
89 bool mpls_output_possible(const struct net_device *dev)
90 {
91 return dev && (dev->flags & IFF_UP) && netif_carrier_ok(dev);
92 }
93 EXPORT_SYMBOL_GPL(mpls_output_possible);
94
95 static u8 *__mpls_nh_via(struct mpls_route *rt, struct mpls_nh *nh)
96 {
97 return (u8 *)nh + rt->rt_via_offset;
98 }
99
100 static const u8 *mpls_nh_via(const struct mpls_route *rt,
101 const struct mpls_nh *nh)
102 {
103 return __mpls_nh_via((struct mpls_route *)rt, (struct mpls_nh *)nh);
104 }
105
106 static unsigned int mpls_nh_header_size(const struct mpls_nh *nh)
107 {
108 /* The size of the layer 2.5 labels to be added for this route */
109 return nh->nh_labels * sizeof(struct mpls_shim_hdr);
110 }
111
112 unsigned int mpls_dev_mtu(const struct net_device *dev)
113 {
114 /* The amount of data the layer 2 frame can hold */
115 return dev->mtu;
116 }
117 EXPORT_SYMBOL_GPL(mpls_dev_mtu);
118
119 bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu)
120 {
121 if (skb->len <= mtu)
122 return false;
123
124 if (skb_is_gso(skb) && skb_gso_validate_mtu(skb, mtu))
125 return false;
126
127 return true;
128 }
129 EXPORT_SYMBOL_GPL(mpls_pkt_too_big);
130
131 void mpls_stats_inc_outucastpkts(struct net_device *dev,
132 const struct sk_buff *skb)
133 {
134 struct mpls_dev *mdev;
135
136 if (skb->protocol == htons(ETH_P_MPLS_UC)) {
137 mdev = mpls_dev_get(dev);
138 if (mdev)
139 MPLS_INC_STATS_LEN(mdev, skb->len,
140 tx_packets,
141 tx_bytes);
142 } else if (skb->protocol == htons(ETH_P_IP)) {
143 IP_UPD_PO_STATS(dev_net(dev), IPSTATS_MIB_OUT, skb->len);
144 #if IS_ENABLED(CONFIG_IPV6)
145 } else if (skb->protocol == htons(ETH_P_IPV6)) {
146 struct inet6_dev *in6dev = __in6_dev_get(dev);
147
148 if (in6dev)
149 IP6_UPD_PO_STATS(dev_net(dev), in6dev,
150 IPSTATS_MIB_OUT, skb->len);
151 #endif
152 }
153 }
154 EXPORT_SYMBOL_GPL(mpls_stats_inc_outucastpkts);
155
156 static u32 mpls_multipath_hash(struct mpls_route *rt, struct sk_buff *skb)
157 {
158 struct mpls_entry_decoded dec;
159 unsigned int mpls_hdr_len = 0;
160 struct mpls_shim_hdr *hdr;
161 bool eli_seen = false;
162 int label_index;
163 u32 hash = 0;
164
165 for (label_index = 0; label_index < MAX_MP_SELECT_LABELS;
166 label_index++) {
167 mpls_hdr_len += sizeof(*hdr);
168 if (!pskb_may_pull(skb, mpls_hdr_len))
169 break;
170
171 /* Read and decode the current label */
172 hdr = mpls_hdr(skb) + label_index;
173 dec = mpls_entry_decode(hdr);
174
175 /* RFC6790 - reserved labels MUST NOT be used as keys
176 * for the load-balancing function
177 */
178 if (likely(dec.label >= MPLS_LABEL_FIRST_UNRESERVED)) {
179 hash = jhash_1word(dec.label, hash);
180
181 /* The entropy label follows the entropy label
182 * indicator, so this means that the entropy
183 * label was just added to the hash - no need to
184 * go any deeper either in the label stack or in the
185 * payload
186 */
187 if (eli_seen)
188 break;
189 } else if (dec.label == MPLS_LABEL_ENTROPY) {
190 eli_seen = true;
191 }
192
193 if (!dec.bos)
194 continue;
195
196 /* found bottom label; does skb have room for a header? */
197 if (pskb_may_pull(skb, mpls_hdr_len + sizeof(struct iphdr))) {
198 const struct iphdr *v4hdr;
199
200 v4hdr = (const struct iphdr *)(hdr + 1);
201 if (v4hdr->version == 4) {
202 hash = jhash_3words(ntohl(v4hdr->saddr),
203 ntohl(v4hdr->daddr),
204 v4hdr->protocol, hash);
205 } else if (v4hdr->version == 6 &&
206 pskb_may_pull(skb, mpls_hdr_len +
207 sizeof(struct ipv6hdr))) {
208 const struct ipv6hdr *v6hdr;
209
210 v6hdr = (const struct ipv6hdr *)(hdr + 1);
211 hash = __ipv6_addr_jhash(&v6hdr->saddr, hash);
212 hash = __ipv6_addr_jhash(&v6hdr->daddr, hash);
213 hash = jhash_1word(v6hdr->nexthdr, hash);
214 }
215 }
216
217 break;
218 }
219
220 return hash;
221 }
222
223 static struct mpls_nh *mpls_get_nexthop(struct mpls_route *rt, u8 index)
224 {
225 return (struct mpls_nh *)((u8 *)rt->rt_nh + index * rt->rt_nh_size);
226 }
227
228 /* number of alive nexthops (rt->rt_nhn_alive) and the flags for
229 * a next hop (nh->nh_flags) are modified by netdev event handlers.
230 * Since those fields can change at any moment, use READ_ONCE to
231 * access both.
232 */
233 static struct mpls_nh *mpls_select_multipath(struct mpls_route *rt,
234 struct sk_buff *skb)
235 {
236 u32 hash = 0;
237 int nh_index = 0;
238 int n = 0;
239 u8 alive;
240
241 /* No need to look further into packet if there's only
242 * one path
243 */
244 if (rt->rt_nhn == 1)
245 return rt->rt_nh;
246
247 alive = READ_ONCE(rt->rt_nhn_alive);
248 if (alive == 0)
249 return NULL;
250
251 hash = mpls_multipath_hash(rt, skb);
252 nh_index = hash % alive;
253 if (alive == rt->rt_nhn)
254 goto out;
255 for_nexthops(rt) {
256 unsigned int nh_flags = READ_ONCE(nh->nh_flags);
257
258 if (nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN))
259 continue;
260 if (n == nh_index)
261 return nh;
262 n++;
263 } endfor_nexthops(rt);
264
265 out:
266 return mpls_get_nexthop(rt, nh_index);
267 }
268
269 static bool mpls_egress(struct net *net, struct mpls_route *rt,
270 struct sk_buff *skb, struct mpls_entry_decoded dec)
271 {
272 enum mpls_payload_type payload_type;
273 bool success = false;
274
275 /* The IPv4 code below accesses through the IPv4 header
276 * checksum, which is 12 bytes into the packet.
277 * The IPv6 code below accesses through the IPv6 hop limit
278 * which is 8 bytes into the packet.
279 *
280 * For all supported cases there should always be at least 12
281 * bytes of packet data present. The IPv4 header is 20 bytes
282 * without options and the IPv6 header is always 40 bytes
283 * long.
284 */
285 if (!pskb_may_pull(skb, 12))
286 return false;
287
288 payload_type = rt->rt_payload_type;
289 if (payload_type == MPT_UNSPEC)
290 payload_type = ip_hdr(skb)->version;
291
292 switch (payload_type) {
293 case MPT_IPV4: {
294 struct iphdr *hdr4 = ip_hdr(skb);
295 u8 new_ttl;
296 skb->protocol = htons(ETH_P_IP);
297
298 /* If propagating TTL, take the decremented TTL from
299 * the incoming MPLS header, otherwise decrement the
300 * TTL, but only if not 0 to avoid underflow.
301 */
302 if (rt->rt_ttl_propagate == MPLS_TTL_PROP_ENABLED ||
303 (rt->rt_ttl_propagate == MPLS_TTL_PROP_DEFAULT &&
304 net->mpls.ip_ttl_propagate))
305 new_ttl = dec.ttl;
306 else
307 new_ttl = hdr4->ttl ? hdr4->ttl - 1 : 0;
308
309 csum_replace2(&hdr4->check,
310 htons(hdr4->ttl << 8),
311 htons(new_ttl << 8));
312 hdr4->ttl = new_ttl;
313 success = true;
314 break;
315 }
316 case MPT_IPV6: {
317 struct ipv6hdr *hdr6 = ipv6_hdr(skb);
318 skb->protocol = htons(ETH_P_IPV6);
319
320 /* If propagating TTL, take the decremented TTL from
321 * the incoming MPLS header, otherwise decrement the
322 * hop limit, but only if not 0 to avoid underflow.
323 */
324 if (rt->rt_ttl_propagate == MPLS_TTL_PROP_ENABLED ||
325 (rt->rt_ttl_propagate == MPLS_TTL_PROP_DEFAULT &&
326 net->mpls.ip_ttl_propagate))
327 hdr6->hop_limit = dec.ttl;
328 else if (hdr6->hop_limit)
329 hdr6->hop_limit = hdr6->hop_limit - 1;
330 success = true;
331 break;
332 }
333 case MPT_UNSPEC:
334 /* Should have decided which protocol it is by now */
335 break;
336 }
337
338 return success;
339 }
340
341 static int mpls_forward(struct sk_buff *skb, struct net_device *dev,
342 struct packet_type *pt, struct net_device *orig_dev)
343 {
344 struct net *net = dev_net(dev);
345 struct mpls_shim_hdr *hdr;
346 struct mpls_route *rt;
347 struct mpls_nh *nh;
348 struct mpls_entry_decoded dec;
349 struct net_device *out_dev;
350 struct mpls_dev *out_mdev;
351 struct mpls_dev *mdev;
352 unsigned int hh_len;
353 unsigned int new_header_size;
354 unsigned int mtu;
355 int err;
356
357 /* Careful this entire function runs inside of an rcu critical section */
358
359 mdev = mpls_dev_get(dev);
360 if (!mdev)
361 goto drop;
362
363 MPLS_INC_STATS_LEN(mdev, skb->len, rx_packets,
364 rx_bytes);
365
366 if (!mdev->input_enabled) {
367 MPLS_INC_STATS(mdev, rx_dropped);
368 goto drop;
369 }
370
371 if (skb->pkt_type != PACKET_HOST)
372 goto err;
373
374 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
375 goto err;
376
377 if (!pskb_may_pull(skb, sizeof(*hdr)))
378 goto err;
379
380 /* Read and decode the label */
381 hdr = mpls_hdr(skb);
382 dec = mpls_entry_decode(hdr);
383
384 rt = mpls_route_input_rcu(net, dec.label);
385 if (!rt) {
386 MPLS_INC_STATS(mdev, rx_noroute);
387 goto drop;
388 }
389
390 nh = mpls_select_multipath(rt, skb);
391 if (!nh)
392 goto err;
393
394 /* Pop the label */
395 skb_pull(skb, sizeof(*hdr));
396 skb_reset_network_header(skb);
397
398 skb_orphan(skb);
399
400 if (skb_warn_if_lro(skb))
401 goto err;
402
403 skb_forward_csum(skb);
404
405 /* Verify ttl is valid */
406 if (dec.ttl <= 1)
407 goto err;
408 dec.ttl -= 1;
409
410 /* Find the output device */
411 out_dev = rcu_dereference(nh->nh_dev);
412 if (!mpls_output_possible(out_dev))
413 goto tx_err;
414
415 /* Verify the destination can hold the packet */
416 new_header_size = mpls_nh_header_size(nh);
417 mtu = mpls_dev_mtu(out_dev);
418 if (mpls_pkt_too_big(skb, mtu - new_header_size))
419 goto tx_err;
420
421 hh_len = LL_RESERVED_SPACE(out_dev);
422 if (!out_dev->header_ops)
423 hh_len = 0;
424
425 /* Ensure there is enough space for the headers in the skb */
426 if (skb_cow(skb, hh_len + new_header_size))
427 goto tx_err;
428
429 skb->dev = out_dev;
430 skb->protocol = htons(ETH_P_MPLS_UC);
431
432 if (unlikely(!new_header_size && dec.bos)) {
433 /* Penultimate hop popping */
434 if (!mpls_egress(dev_net(out_dev), rt, skb, dec))
435 goto err;
436 } else {
437 bool bos;
438 int i;
439 skb_push(skb, new_header_size);
440 skb_reset_network_header(skb);
441 /* Push the new labels */
442 hdr = mpls_hdr(skb);
443 bos = dec.bos;
444 for (i = nh->nh_labels - 1; i >= 0; i--) {
445 hdr[i] = mpls_entry_encode(nh->nh_label[i],
446 dec.ttl, 0, bos);
447 bos = false;
448 }
449 }
450
451 mpls_stats_inc_outucastpkts(out_dev, skb);
452
453 /* If via wasn't specified then send out using device address */
454 if (nh->nh_via_table == MPLS_NEIGH_TABLE_UNSPEC)
455 err = neigh_xmit(NEIGH_LINK_TABLE, out_dev,
456 out_dev->dev_addr, skb);
457 else
458 err = neigh_xmit(nh->nh_via_table, out_dev,
459 mpls_nh_via(rt, nh), skb);
460 if (err)
461 net_dbg_ratelimited("%s: packet transmission failed: %d\n",
462 __func__, err);
463 return 0;
464
465 tx_err:
466 out_mdev = out_dev ? mpls_dev_get(out_dev) : NULL;
467 if (out_mdev)
468 MPLS_INC_STATS(out_mdev, tx_errors);
469 goto drop;
470 err:
471 MPLS_INC_STATS(mdev, rx_errors);
472 drop:
473 kfree_skb(skb);
474 return NET_RX_DROP;
475 }
476
477 static struct packet_type mpls_packet_type __read_mostly = {
478 .type = cpu_to_be16(ETH_P_MPLS_UC),
479 .func = mpls_forward,
480 };
481
482 static const struct nla_policy rtm_mpls_policy[RTA_MAX+1] = {
483 [RTA_DST] = { .type = NLA_U32 },
484 [RTA_OIF] = { .type = NLA_U32 },
485 [RTA_TTL_PROPAGATE] = { .type = NLA_U8 },
486 };
487
488 struct mpls_route_config {
489 u32 rc_protocol;
490 u32 rc_ifindex;
491 u8 rc_via_table;
492 u8 rc_via_alen;
493 u8 rc_via[MAX_VIA_ALEN];
494 u32 rc_label;
495 u8 rc_ttl_propagate;
496 u8 rc_output_labels;
497 u32 rc_output_label[MAX_NEW_LABELS];
498 u32 rc_nlflags;
499 enum mpls_payload_type rc_payload_type;
500 struct nl_info rc_nlinfo;
501 struct rtnexthop *rc_mp;
502 int rc_mp_len;
503 };
504
505 /* all nexthops within a route have the same size based on max
506 * number of labels and max via length for a hop
507 */
508 static struct mpls_route *mpls_rt_alloc(u8 num_nh, u8 max_alen, u8 max_labels)
509 {
510 u8 nh_size = MPLS_NH_SIZE(max_labels, max_alen);
511 struct mpls_route *rt;
512 size_t size;
513
514 size = sizeof(*rt) + num_nh * nh_size;
515 if (size > MAX_MPLS_ROUTE_MEM)
516 return ERR_PTR(-EINVAL);
517
518 rt = kzalloc(size, GFP_KERNEL);
519 if (!rt)
520 return ERR_PTR(-ENOMEM);
521
522 rt->rt_nhn = num_nh;
523 rt->rt_nhn_alive = num_nh;
524 rt->rt_nh_size = nh_size;
525 rt->rt_via_offset = MPLS_NH_VIA_OFF(max_labels);
526
527 return rt;
528 }
529
530 static void mpls_rt_free(struct mpls_route *rt)
531 {
532 if (rt)
533 kfree_rcu(rt, rt_rcu);
534 }
535
536 static void mpls_notify_route(struct net *net, unsigned index,
537 struct mpls_route *old, struct mpls_route *new,
538 const struct nl_info *info)
539 {
540 struct nlmsghdr *nlh = info ? info->nlh : NULL;
541 unsigned portid = info ? info->portid : 0;
542 int event = new ? RTM_NEWROUTE : RTM_DELROUTE;
543 struct mpls_route *rt = new ? new : old;
544 unsigned nlm_flags = (old && new) ? NLM_F_REPLACE : 0;
545 /* Ignore reserved labels for now */
546 if (rt && (index >= MPLS_LABEL_FIRST_UNRESERVED))
547 rtmsg_lfib(event, index, rt, nlh, net, portid, nlm_flags);
548 }
549
550 static void mpls_route_update(struct net *net, unsigned index,
551 struct mpls_route *new,
552 const struct nl_info *info)
553 {
554 struct mpls_route __rcu **platform_label;
555 struct mpls_route *rt;
556
557 ASSERT_RTNL();
558
559 platform_label = rtnl_dereference(net->mpls.platform_label);
560 rt = rtnl_dereference(platform_label[index]);
561 rcu_assign_pointer(platform_label[index], new);
562
563 mpls_notify_route(net, index, rt, new, info);
564
565 /* If we removed a route free it now */
566 mpls_rt_free(rt);
567 }
568
569 static unsigned find_free_label(struct net *net)
570 {
571 struct mpls_route __rcu **platform_label;
572 size_t platform_labels;
573 unsigned index;
574
575 platform_label = rtnl_dereference(net->mpls.platform_label);
576 platform_labels = net->mpls.platform_labels;
577 for (index = MPLS_LABEL_FIRST_UNRESERVED; index < platform_labels;
578 index++) {
579 if (!rtnl_dereference(platform_label[index]))
580 return index;
581 }
582 return LABEL_NOT_SPECIFIED;
583 }
584
585 #if IS_ENABLED(CONFIG_INET)
586 static struct net_device *inet_fib_lookup_dev(struct net *net,
587 const void *addr)
588 {
589 struct net_device *dev;
590 struct rtable *rt;
591 struct in_addr daddr;
592
593 memcpy(&daddr, addr, sizeof(struct in_addr));
594 rt = ip_route_output(net, daddr.s_addr, 0, 0, 0);
595 if (IS_ERR(rt))
596 return ERR_CAST(rt);
597
598 dev = rt->dst.dev;
599 dev_hold(dev);
600
601 ip_rt_put(rt);
602
603 return dev;
604 }
605 #else
606 static struct net_device *inet_fib_lookup_dev(struct net *net,
607 const void *addr)
608 {
609 return ERR_PTR(-EAFNOSUPPORT);
610 }
611 #endif
612
613 #if IS_ENABLED(CONFIG_IPV6)
614 static struct net_device *inet6_fib_lookup_dev(struct net *net,
615 const void *addr)
616 {
617 struct net_device *dev;
618 struct dst_entry *dst;
619 struct flowi6 fl6;
620 int err;
621
622 if (!ipv6_stub)
623 return ERR_PTR(-EAFNOSUPPORT);
624
625 memset(&fl6, 0, sizeof(fl6));
626 memcpy(&fl6.daddr, addr, sizeof(struct in6_addr));
627 err = ipv6_stub->ipv6_dst_lookup(net, NULL, &dst, &fl6);
628 if (err)
629 return ERR_PTR(err);
630
631 dev = dst->dev;
632 dev_hold(dev);
633 dst_release(dst);
634
635 return dev;
636 }
637 #else
638 static struct net_device *inet6_fib_lookup_dev(struct net *net,
639 const void *addr)
640 {
641 return ERR_PTR(-EAFNOSUPPORT);
642 }
643 #endif
644
645 static struct net_device *find_outdev(struct net *net,
646 struct mpls_route *rt,
647 struct mpls_nh *nh, int oif)
648 {
649 struct net_device *dev = NULL;
650
651 if (!oif) {
652 switch (nh->nh_via_table) {
653 case NEIGH_ARP_TABLE:
654 dev = inet_fib_lookup_dev(net, mpls_nh_via(rt, nh));
655 break;
656 case NEIGH_ND_TABLE:
657 dev = inet6_fib_lookup_dev(net, mpls_nh_via(rt, nh));
658 break;
659 case NEIGH_LINK_TABLE:
660 break;
661 }
662 } else {
663 dev = dev_get_by_index(net, oif);
664 }
665
666 if (!dev)
667 return ERR_PTR(-ENODEV);
668
669 if (IS_ERR(dev))
670 return dev;
671
672 /* The caller is holding rtnl anyways, so release the dev reference */
673 dev_put(dev);
674
675 return dev;
676 }
677
678 static int mpls_nh_assign_dev(struct net *net, struct mpls_route *rt,
679 struct mpls_nh *nh, int oif)
680 {
681 struct net_device *dev = NULL;
682 int err = -ENODEV;
683
684 dev = find_outdev(net, rt, nh, oif);
685 if (IS_ERR(dev)) {
686 err = PTR_ERR(dev);
687 dev = NULL;
688 goto errout;
689 }
690
691 /* Ensure this is a supported device */
692 err = -EINVAL;
693 if (!mpls_dev_get(dev))
694 goto errout;
695
696 if ((nh->nh_via_table == NEIGH_LINK_TABLE) &&
697 (dev->addr_len != nh->nh_via_alen))
698 goto errout;
699
700 RCU_INIT_POINTER(nh->nh_dev, dev);
701
702 if (!(dev->flags & IFF_UP)) {
703 nh->nh_flags |= RTNH_F_DEAD;
704 } else {
705 unsigned int flags;
706
707 flags = dev_get_flags(dev);
708 if (!(flags & (IFF_RUNNING | IFF_LOWER_UP)))
709 nh->nh_flags |= RTNH_F_LINKDOWN;
710 }
711
712 return 0;
713
714 errout:
715 return err;
716 }
717
718 static int nla_get_via(const struct nlattr *nla, u8 *via_alen, u8 *via_table,
719 u8 via_addr[], struct netlink_ext_ack *extack)
720 {
721 struct rtvia *via = nla_data(nla);
722 int err = -EINVAL;
723 int alen;
724
725 if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) {
726 NL_SET_ERR_MSG_ATTR(extack, nla,
727 "Invalid attribute length for RTA_VIA");
728 goto errout;
729 }
730 alen = nla_len(nla) -
731 offsetof(struct rtvia, rtvia_addr);
732 if (alen > MAX_VIA_ALEN) {
733 NL_SET_ERR_MSG_ATTR(extack, nla,
734 "Invalid address length for RTA_VIA");
735 goto errout;
736 }
737
738 /* Validate the address family */
739 switch (via->rtvia_family) {
740 case AF_PACKET:
741 *via_table = NEIGH_LINK_TABLE;
742 break;
743 case AF_INET:
744 *via_table = NEIGH_ARP_TABLE;
745 if (alen != 4)
746 goto errout;
747 break;
748 case AF_INET6:
749 *via_table = NEIGH_ND_TABLE;
750 if (alen != 16)
751 goto errout;
752 break;
753 default:
754 /* Unsupported address family */
755 goto errout;
756 }
757
758 memcpy(via_addr, via->rtvia_addr, alen);
759 *via_alen = alen;
760 err = 0;
761
762 errout:
763 return err;
764 }
765
766 static int mpls_nh_build_from_cfg(struct mpls_route_config *cfg,
767 struct mpls_route *rt)
768 {
769 struct net *net = cfg->rc_nlinfo.nl_net;
770 struct mpls_nh *nh = rt->rt_nh;
771 int err;
772 int i;
773
774 if (!nh)
775 return -ENOMEM;
776
777 nh->nh_labels = cfg->rc_output_labels;
778 for (i = 0; i < nh->nh_labels; i++)
779 nh->nh_label[i] = cfg->rc_output_label[i];
780
781 nh->nh_via_table = cfg->rc_via_table;
782 memcpy(__mpls_nh_via(rt, nh), cfg->rc_via, cfg->rc_via_alen);
783 nh->nh_via_alen = cfg->rc_via_alen;
784
785 err = mpls_nh_assign_dev(net, rt, nh, cfg->rc_ifindex);
786 if (err)
787 goto errout;
788
789 if (nh->nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN))
790 rt->rt_nhn_alive--;
791
792 return 0;
793
794 errout:
795 return err;
796 }
797
798 static int mpls_nh_build(struct net *net, struct mpls_route *rt,
799 struct mpls_nh *nh, int oif, struct nlattr *via,
800 struct nlattr *newdst, u8 max_labels,
801 struct netlink_ext_ack *extack)
802 {
803 int err = -ENOMEM;
804
805 if (!nh)
806 goto errout;
807
808 if (newdst) {
809 err = nla_get_labels(newdst, max_labels, &nh->nh_labels,
810 nh->nh_label, extack);
811 if (err)
812 goto errout;
813 }
814
815 if (via) {
816 err = nla_get_via(via, &nh->nh_via_alen, &nh->nh_via_table,
817 __mpls_nh_via(rt, nh), extack);
818 if (err)
819 goto errout;
820 } else {
821 nh->nh_via_table = MPLS_NEIGH_TABLE_UNSPEC;
822 }
823
824 err = mpls_nh_assign_dev(net, rt, nh, oif);
825 if (err)
826 goto errout;
827
828 return 0;
829
830 errout:
831 return err;
832 }
833
834 static u8 mpls_count_nexthops(struct rtnexthop *rtnh, int len,
835 u8 cfg_via_alen, u8 *max_via_alen,
836 u8 *max_labels)
837 {
838 int remaining = len;
839 u8 nhs = 0;
840
841 *max_via_alen = 0;
842 *max_labels = 0;
843
844 while (rtnh_ok(rtnh, remaining)) {
845 struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
846 int attrlen;
847 u8 n_labels = 0;
848
849 attrlen = rtnh_attrlen(rtnh);
850 nla = nla_find(attrs, attrlen, RTA_VIA);
851 if (nla && nla_len(nla) >=
852 offsetof(struct rtvia, rtvia_addr)) {
853 int via_alen = nla_len(nla) -
854 offsetof(struct rtvia, rtvia_addr);
855
856 if (via_alen <= MAX_VIA_ALEN)
857 *max_via_alen = max_t(u16, *max_via_alen,
858 via_alen);
859 }
860
861 nla = nla_find(attrs, attrlen, RTA_NEWDST);
862 if (nla &&
863 nla_get_labels(nla, MAX_NEW_LABELS, &n_labels,
864 NULL, NULL) != 0)
865 return 0;
866
867 *max_labels = max_t(u8, *max_labels, n_labels);
868
869 /* number of nexthops is tracked by a u8.
870 * Check for overflow.
871 */
872 if (nhs == 255)
873 return 0;
874 nhs++;
875
876 rtnh = rtnh_next(rtnh, &remaining);
877 }
878
879 /* leftover implies invalid nexthop configuration, discard it */
880 return remaining > 0 ? 0 : nhs;
881 }
882
883 static int mpls_nh_build_multi(struct mpls_route_config *cfg,
884 struct mpls_route *rt, u8 max_labels,
885 struct netlink_ext_ack *extack)
886 {
887 struct rtnexthop *rtnh = cfg->rc_mp;
888 struct nlattr *nla_via, *nla_newdst;
889 int remaining = cfg->rc_mp_len;
890 int err = 0;
891 u8 nhs = 0;
892
893 change_nexthops(rt) {
894 int attrlen;
895
896 nla_via = NULL;
897 nla_newdst = NULL;
898
899 err = -EINVAL;
900 if (!rtnh_ok(rtnh, remaining))
901 goto errout;
902
903 /* neither weighted multipath nor any flags
904 * are supported
905 */
906 if (rtnh->rtnh_hops || rtnh->rtnh_flags)
907 goto errout;
908
909 attrlen = rtnh_attrlen(rtnh);
910 if (attrlen > 0) {
911 struct nlattr *attrs = rtnh_attrs(rtnh);
912
913 nla_via = nla_find(attrs, attrlen, RTA_VIA);
914 nla_newdst = nla_find(attrs, attrlen, RTA_NEWDST);
915 }
916
917 err = mpls_nh_build(cfg->rc_nlinfo.nl_net, rt, nh,
918 rtnh->rtnh_ifindex, nla_via, nla_newdst,
919 max_labels, extack);
920 if (err)
921 goto errout;
922
923 if (nh->nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN))
924 rt->rt_nhn_alive--;
925
926 rtnh = rtnh_next(rtnh, &remaining);
927 nhs++;
928 } endfor_nexthops(rt);
929
930 rt->rt_nhn = nhs;
931
932 return 0;
933
934 errout:
935 return err;
936 }
937
938 static bool mpls_label_ok(struct net *net, unsigned int index,
939 struct netlink_ext_ack *extack)
940 {
941 /* Reserved labels may not be set */
942 if (index < MPLS_LABEL_FIRST_UNRESERVED) {
943 NL_SET_ERR_MSG(extack,
944 "Invalid label - must be MPLS_LABEL_FIRST_UNRESERVED or higher");
945 return false;
946 }
947
948 /* The full 20 bit range may not be supported. */
949 if (index >= net->mpls.platform_labels) {
950 NL_SET_ERR_MSG(extack,
951 "Label >= configured maximum in platform_labels");
952 return false;
953 }
954
955 return true;
956 }
957
958 static int mpls_route_add(struct mpls_route_config *cfg,
959 struct netlink_ext_ack *extack)
960 {
961 struct mpls_route __rcu **platform_label;
962 struct net *net = cfg->rc_nlinfo.nl_net;
963 struct mpls_route *rt, *old;
964 int err = -EINVAL;
965 u8 max_via_alen;
966 unsigned index;
967 u8 max_labels;
968 u8 nhs;
969
970 index = cfg->rc_label;
971
972 /* If a label was not specified during insert pick one */
973 if ((index == LABEL_NOT_SPECIFIED) &&
974 (cfg->rc_nlflags & NLM_F_CREATE)) {
975 index = find_free_label(net);
976 }
977
978 if (!mpls_label_ok(net, index, extack))
979 goto errout;
980
981 /* Append makes no sense with mpls */
982 err = -EOPNOTSUPP;
983 if (cfg->rc_nlflags & NLM_F_APPEND) {
984 NL_SET_ERR_MSG(extack, "MPLS does not support route append");
985 goto errout;
986 }
987
988 err = -EEXIST;
989 platform_label = rtnl_dereference(net->mpls.platform_label);
990 old = rtnl_dereference(platform_label[index]);
991 if ((cfg->rc_nlflags & NLM_F_EXCL) && old)
992 goto errout;
993
994 err = -EEXIST;
995 if (!(cfg->rc_nlflags & NLM_F_REPLACE) && old)
996 goto errout;
997
998 err = -ENOENT;
999 if (!(cfg->rc_nlflags & NLM_F_CREATE) && !old)
1000 goto errout;
1001
1002 err = -EINVAL;
1003 if (cfg->rc_mp) {
1004 nhs = mpls_count_nexthops(cfg->rc_mp, cfg->rc_mp_len,
1005 cfg->rc_via_alen, &max_via_alen,
1006 &max_labels);
1007 } else {
1008 max_via_alen = cfg->rc_via_alen;
1009 max_labels = cfg->rc_output_labels;
1010 nhs = 1;
1011 }
1012
1013 if (nhs == 0) {
1014 NL_SET_ERR_MSG(extack, "Route does not contain a nexthop");
1015 goto errout;
1016 }
1017
1018 err = -ENOMEM;
1019 rt = mpls_rt_alloc(nhs, max_via_alen, max_labels);
1020 if (IS_ERR(rt)) {
1021 err = PTR_ERR(rt);
1022 goto errout;
1023 }
1024
1025 rt->rt_protocol = cfg->rc_protocol;
1026 rt->rt_payload_type = cfg->rc_payload_type;
1027 rt->rt_ttl_propagate = cfg->rc_ttl_propagate;
1028
1029 if (cfg->rc_mp)
1030 err = mpls_nh_build_multi(cfg, rt, max_labels, extack);
1031 else
1032 err = mpls_nh_build_from_cfg(cfg, rt);
1033 if (err)
1034 goto freert;
1035
1036 mpls_route_update(net, index, rt, &cfg->rc_nlinfo);
1037
1038 return 0;
1039
1040 freert:
1041 mpls_rt_free(rt);
1042 errout:
1043 return err;
1044 }
1045
1046 static int mpls_route_del(struct mpls_route_config *cfg,
1047 struct netlink_ext_ack *extack)
1048 {
1049 struct net *net = cfg->rc_nlinfo.nl_net;
1050 unsigned index;
1051 int err = -EINVAL;
1052
1053 index = cfg->rc_label;
1054
1055 if (!mpls_label_ok(net, index, extack))
1056 goto errout;
1057
1058 mpls_route_update(net, index, NULL, &cfg->rc_nlinfo);
1059
1060 err = 0;
1061 errout:
1062 return err;
1063 }
1064
1065 static void mpls_get_stats(struct mpls_dev *mdev,
1066 struct mpls_link_stats *stats)
1067 {
1068 struct mpls_pcpu_stats *p;
1069 int i;
1070
1071 memset(stats, 0, sizeof(*stats));
1072
1073 for_each_possible_cpu(i) {
1074 struct mpls_link_stats local;
1075 unsigned int start;
1076
1077 p = per_cpu_ptr(mdev->stats, i);
1078 do {
1079 start = u64_stats_fetch_begin(&p->syncp);
1080 local = p->stats;
1081 } while (u64_stats_fetch_retry(&p->syncp, start));
1082
1083 stats->rx_packets += local.rx_packets;
1084 stats->rx_bytes += local.rx_bytes;
1085 stats->tx_packets += local.tx_packets;
1086 stats->tx_bytes += local.tx_bytes;
1087 stats->rx_errors += local.rx_errors;
1088 stats->tx_errors += local.tx_errors;
1089 stats->rx_dropped += local.rx_dropped;
1090 stats->tx_dropped += local.tx_dropped;
1091 stats->rx_noroute += local.rx_noroute;
1092 }
1093 }
1094
1095 static int mpls_fill_stats_af(struct sk_buff *skb,
1096 const struct net_device *dev)
1097 {
1098 struct mpls_link_stats *stats;
1099 struct mpls_dev *mdev;
1100 struct nlattr *nla;
1101
1102 mdev = mpls_dev_get(dev);
1103 if (!mdev)
1104 return -ENODATA;
1105
1106 nla = nla_reserve_64bit(skb, MPLS_STATS_LINK,
1107 sizeof(struct mpls_link_stats),
1108 MPLS_STATS_UNSPEC);
1109 if (!nla)
1110 return -EMSGSIZE;
1111
1112 stats = nla_data(nla);
1113 mpls_get_stats(mdev, stats);
1114
1115 return 0;
1116 }
1117
1118 static size_t mpls_get_stats_af_size(const struct net_device *dev)
1119 {
1120 struct mpls_dev *mdev;
1121
1122 mdev = mpls_dev_get(dev);
1123 if (!mdev)
1124 return 0;
1125
1126 return nla_total_size_64bit(sizeof(struct mpls_link_stats));
1127 }
1128
1129 static int mpls_netconf_fill_devconf(struct sk_buff *skb, struct mpls_dev *mdev,
1130 u32 portid, u32 seq, int event,
1131 unsigned int flags, int type)
1132 {
1133 struct nlmsghdr *nlh;
1134 struct netconfmsg *ncm;
1135 bool all = false;
1136
1137 nlh = nlmsg_put(skb, portid, seq, event, sizeof(struct netconfmsg),
1138 flags);
1139 if (!nlh)
1140 return -EMSGSIZE;
1141
1142 if (type == NETCONFA_ALL)
1143 all = true;
1144
1145 ncm = nlmsg_data(nlh);
1146 ncm->ncm_family = AF_MPLS;
1147
1148 if (nla_put_s32(skb, NETCONFA_IFINDEX, mdev->dev->ifindex) < 0)
1149 goto nla_put_failure;
1150
1151 if ((all || type == NETCONFA_INPUT) &&
1152 nla_put_s32(skb, NETCONFA_INPUT,
1153 mdev->input_enabled) < 0)
1154 goto nla_put_failure;
1155
1156 nlmsg_end(skb, nlh);
1157 return 0;
1158
1159 nla_put_failure:
1160 nlmsg_cancel(skb, nlh);
1161 return -EMSGSIZE;
1162 }
1163
1164 static int mpls_netconf_msgsize_devconf(int type)
1165 {
1166 int size = NLMSG_ALIGN(sizeof(struct netconfmsg))
1167 + nla_total_size(4); /* NETCONFA_IFINDEX */
1168 bool all = false;
1169
1170 if (type == NETCONFA_ALL)
1171 all = true;
1172
1173 if (all || type == NETCONFA_INPUT)
1174 size += nla_total_size(4);
1175
1176 return size;
1177 }
1178
1179 static void mpls_netconf_notify_devconf(struct net *net, int event,
1180 int type, struct mpls_dev *mdev)
1181 {
1182 struct sk_buff *skb;
1183 int err = -ENOBUFS;
1184
1185 skb = nlmsg_new(mpls_netconf_msgsize_devconf(type), GFP_KERNEL);
1186 if (!skb)
1187 goto errout;
1188
1189 err = mpls_netconf_fill_devconf(skb, mdev, 0, 0, event, 0, type);
1190 if (err < 0) {
1191 /* -EMSGSIZE implies BUG in mpls_netconf_msgsize_devconf() */
1192 WARN_ON(err == -EMSGSIZE);
1193 kfree_skb(skb);
1194 goto errout;
1195 }
1196
1197 rtnl_notify(skb, net, 0, RTNLGRP_MPLS_NETCONF, NULL, GFP_KERNEL);
1198 return;
1199 errout:
1200 if (err < 0)
1201 rtnl_set_sk_err(net, RTNLGRP_MPLS_NETCONF, err);
1202 }
1203
1204 static const struct nla_policy devconf_mpls_policy[NETCONFA_MAX + 1] = {
1205 [NETCONFA_IFINDEX] = { .len = sizeof(int) },
1206 };
1207
1208 static int mpls_netconf_get_devconf(struct sk_buff *in_skb,
1209 struct nlmsghdr *nlh,
1210 struct netlink_ext_ack *extack)
1211 {
1212 struct net *net = sock_net(in_skb->sk);
1213 struct nlattr *tb[NETCONFA_MAX + 1];
1214 struct netconfmsg *ncm;
1215 struct net_device *dev;
1216 struct mpls_dev *mdev;
1217 struct sk_buff *skb;
1218 int ifindex;
1219 int err;
1220
1221 err = nlmsg_parse(nlh, sizeof(*ncm), tb, NETCONFA_MAX,
1222 devconf_mpls_policy, NULL);
1223 if (err < 0)
1224 goto errout;
1225
1226 err = -EINVAL;
1227 if (!tb[NETCONFA_IFINDEX])
1228 goto errout;
1229
1230 ifindex = nla_get_s32(tb[NETCONFA_IFINDEX]);
1231 dev = __dev_get_by_index(net, ifindex);
1232 if (!dev)
1233 goto errout;
1234
1235 mdev = mpls_dev_get(dev);
1236 if (!mdev)
1237 goto errout;
1238
1239 err = -ENOBUFS;
1240 skb = nlmsg_new(mpls_netconf_msgsize_devconf(NETCONFA_ALL), GFP_KERNEL);
1241 if (!skb)
1242 goto errout;
1243
1244 err = mpls_netconf_fill_devconf(skb, mdev,
1245 NETLINK_CB(in_skb).portid,
1246 nlh->nlmsg_seq, RTM_NEWNETCONF, 0,
1247 NETCONFA_ALL);
1248 if (err < 0) {
1249 /* -EMSGSIZE implies BUG in mpls_netconf_msgsize_devconf() */
1250 WARN_ON(err == -EMSGSIZE);
1251 kfree_skb(skb);
1252 goto errout;
1253 }
1254 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
1255 errout:
1256 return err;
1257 }
1258
1259 static int mpls_netconf_dump_devconf(struct sk_buff *skb,
1260 struct netlink_callback *cb)
1261 {
1262 struct net *net = sock_net(skb->sk);
1263 struct hlist_head *head;
1264 struct net_device *dev;
1265 struct mpls_dev *mdev;
1266 int idx, s_idx;
1267 int h, s_h;
1268
1269 s_h = cb->args[0];
1270 s_idx = idx = cb->args[1];
1271
1272 for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {
1273 idx = 0;
1274 head = &net->dev_index_head[h];
1275 rcu_read_lock();
1276 cb->seq = net->dev_base_seq;
1277 hlist_for_each_entry_rcu(dev, head, index_hlist) {
1278 if (idx < s_idx)
1279 goto cont;
1280 mdev = mpls_dev_get(dev);
1281 if (!mdev)
1282 goto cont;
1283 if (mpls_netconf_fill_devconf(skb, mdev,
1284 NETLINK_CB(cb->skb).portid,
1285 cb->nlh->nlmsg_seq,
1286 RTM_NEWNETCONF,
1287 NLM_F_MULTI,
1288 NETCONFA_ALL) < 0) {
1289 rcu_read_unlock();
1290 goto done;
1291 }
1292 nl_dump_check_consistent(cb, nlmsg_hdr(skb));
1293 cont:
1294 idx++;
1295 }
1296 rcu_read_unlock();
1297 }
1298 done:
1299 cb->args[0] = h;
1300 cb->args[1] = idx;
1301
1302 return skb->len;
1303 }
1304
1305 #define MPLS_PERDEV_SYSCTL_OFFSET(field) \
1306 (&((struct mpls_dev *)0)->field)
1307
1308 static int mpls_conf_proc(struct ctl_table *ctl, int write,
1309 void __user *buffer,
1310 size_t *lenp, loff_t *ppos)
1311 {
1312 int oval = *(int *)ctl->data;
1313 int ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
1314
1315 if (write) {
1316 struct mpls_dev *mdev = ctl->extra1;
1317 int i = (int *)ctl->data - (int *)mdev;
1318 struct net *net = ctl->extra2;
1319 int val = *(int *)ctl->data;
1320
1321 if (i == offsetof(struct mpls_dev, input_enabled) &&
1322 val != oval) {
1323 mpls_netconf_notify_devconf(net, RTM_NEWNETCONF,
1324 NETCONFA_INPUT, mdev);
1325 }
1326 }
1327
1328 return ret;
1329 }
1330
1331 static const struct ctl_table mpls_dev_table[] = {
1332 {
1333 .procname = "input",
1334 .maxlen = sizeof(int),
1335 .mode = 0644,
1336 .proc_handler = mpls_conf_proc,
1337 .data = MPLS_PERDEV_SYSCTL_OFFSET(input_enabled),
1338 },
1339 { }
1340 };
1341
1342 static int mpls_dev_sysctl_register(struct net_device *dev,
1343 struct mpls_dev *mdev)
1344 {
1345 char path[sizeof("net/mpls/conf/") + IFNAMSIZ];
1346 struct net *net = dev_net(dev);
1347 struct ctl_table *table;
1348 int i;
1349
1350 table = kmemdup(&mpls_dev_table, sizeof(mpls_dev_table), GFP_KERNEL);
1351 if (!table)
1352 goto out;
1353
1354 /* Table data contains only offsets relative to the base of
1355 * the mdev at this point, so make them absolute.
1356 */
1357 for (i = 0; i < ARRAY_SIZE(mpls_dev_table); i++) {
1358 table[i].data = (char *)mdev + (uintptr_t)table[i].data;
1359 table[i].extra1 = mdev;
1360 table[i].extra2 = net;
1361 }
1362
1363 snprintf(path, sizeof(path), "net/mpls/conf/%s", dev->name);
1364
1365 mdev->sysctl = register_net_sysctl(net, path, table);
1366 if (!mdev->sysctl)
1367 goto free;
1368
1369 mpls_netconf_notify_devconf(net, RTM_NEWNETCONF, NETCONFA_ALL, mdev);
1370 return 0;
1371
1372 free:
1373 kfree(table);
1374 out:
1375 return -ENOBUFS;
1376 }
1377
1378 static void mpls_dev_sysctl_unregister(struct net_device *dev,
1379 struct mpls_dev *mdev)
1380 {
1381 struct net *net = dev_net(dev);
1382 struct ctl_table *table;
1383
1384 table = mdev->sysctl->ctl_table_arg;
1385 unregister_net_sysctl_table(mdev->sysctl);
1386 kfree(table);
1387
1388 mpls_netconf_notify_devconf(net, RTM_DELNETCONF, 0, mdev);
1389 }
1390
1391 static struct mpls_dev *mpls_add_dev(struct net_device *dev)
1392 {
1393 struct mpls_dev *mdev;
1394 int err = -ENOMEM;
1395 int i;
1396
1397 ASSERT_RTNL();
1398
1399 mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
1400 if (!mdev)
1401 return ERR_PTR(err);
1402
1403 mdev->stats = alloc_percpu(struct mpls_pcpu_stats);
1404 if (!mdev->stats)
1405 goto free;
1406
1407 for_each_possible_cpu(i) {
1408 struct mpls_pcpu_stats *mpls_stats;
1409
1410 mpls_stats = per_cpu_ptr(mdev->stats, i);
1411 u64_stats_init(&mpls_stats->syncp);
1412 }
1413
1414 mdev->dev = dev;
1415
1416 err = mpls_dev_sysctl_register(dev, mdev);
1417 if (err)
1418 goto free;
1419
1420 rcu_assign_pointer(dev->mpls_ptr, mdev);
1421
1422 return mdev;
1423
1424 free:
1425 free_percpu(mdev->stats);
1426 kfree(mdev);
1427 return ERR_PTR(err);
1428 }
1429
1430 static void mpls_dev_destroy_rcu(struct rcu_head *head)
1431 {
1432 struct mpls_dev *mdev = container_of(head, struct mpls_dev, rcu);
1433
1434 free_percpu(mdev->stats);
1435 kfree(mdev);
1436 }
1437
1438 static void mpls_ifdown(struct net_device *dev, int event)
1439 {
1440 struct mpls_route __rcu **platform_label;
1441 struct net *net = dev_net(dev);
1442 u8 alive, deleted;
1443 unsigned index;
1444
1445 platform_label = rtnl_dereference(net->mpls.platform_label);
1446 for (index = 0; index < net->mpls.platform_labels; index++) {
1447 struct mpls_route *rt = rtnl_dereference(platform_label[index]);
1448
1449 if (!rt)
1450 continue;
1451
1452 alive = 0;
1453 deleted = 0;
1454 change_nexthops(rt) {
1455 unsigned int nh_flags = nh->nh_flags;
1456
1457 if (rtnl_dereference(nh->nh_dev) != dev)
1458 goto next;
1459
1460 switch (event) {
1461 case NETDEV_DOWN:
1462 case NETDEV_UNREGISTER:
1463 nh_flags |= RTNH_F_DEAD;
1464 /* fall through */
1465 case NETDEV_CHANGE:
1466 nh_flags |= RTNH_F_LINKDOWN;
1467 break;
1468 }
1469 if (event == NETDEV_UNREGISTER)
1470 RCU_INIT_POINTER(nh->nh_dev, NULL);
1471
1472 if (nh->nh_flags != nh_flags)
1473 WRITE_ONCE(nh->nh_flags, nh_flags);
1474 next:
1475 if (!(nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)))
1476 alive++;
1477 if (!rtnl_dereference(nh->nh_dev))
1478 deleted++;
1479 } endfor_nexthops(rt);
1480
1481 WRITE_ONCE(rt->rt_nhn_alive, alive);
1482
1483 /* if there are no more nexthops, delete the route */
1484 if (event == NETDEV_UNREGISTER && deleted == rt->rt_nhn)
1485 mpls_route_update(net, index, NULL, NULL);
1486 }
1487 }
1488
1489 static void mpls_ifup(struct net_device *dev, unsigned int flags)
1490 {
1491 struct mpls_route __rcu **platform_label;
1492 struct net *net = dev_net(dev);
1493 unsigned index;
1494 u8 alive;
1495
1496 platform_label = rtnl_dereference(net->mpls.platform_label);
1497 for (index = 0; index < net->mpls.platform_labels; index++) {
1498 struct mpls_route *rt = rtnl_dereference(platform_label[index]);
1499
1500 if (!rt)
1501 continue;
1502
1503 alive = 0;
1504 change_nexthops(rt) {
1505 unsigned int nh_flags = nh->nh_flags;
1506 struct net_device *nh_dev =
1507 rtnl_dereference(nh->nh_dev);
1508
1509 if (!(nh_flags & flags)) {
1510 alive++;
1511 continue;
1512 }
1513 if (nh_dev != dev)
1514 continue;
1515 alive++;
1516 nh_flags &= ~flags;
1517 WRITE_ONCE(nh->nh_flags, nh_flags);
1518 } endfor_nexthops(rt);
1519
1520 WRITE_ONCE(rt->rt_nhn_alive, alive);
1521 }
1522 }
1523
1524 static int mpls_dev_notify(struct notifier_block *this, unsigned long event,
1525 void *ptr)
1526 {
1527 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1528 struct mpls_dev *mdev;
1529 unsigned int flags;
1530
1531 if (event == NETDEV_REGISTER) {
1532 /* For now just support Ethernet, IPGRE, SIT and IPIP devices */
1533 if (dev->type == ARPHRD_ETHER ||
1534 dev->type == ARPHRD_LOOPBACK ||
1535 dev->type == ARPHRD_IPGRE ||
1536 dev->type == ARPHRD_SIT ||
1537 dev->type == ARPHRD_TUNNEL) {
1538 mdev = mpls_add_dev(dev);
1539 if (IS_ERR(mdev))
1540 return notifier_from_errno(PTR_ERR(mdev));
1541 }
1542 return NOTIFY_OK;
1543 }
1544
1545 mdev = mpls_dev_get(dev);
1546 if (!mdev)
1547 return NOTIFY_OK;
1548
1549 switch (event) {
1550 case NETDEV_DOWN:
1551 mpls_ifdown(dev, event);
1552 break;
1553 case NETDEV_UP:
1554 flags = dev_get_flags(dev);
1555 if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1556 mpls_ifup(dev, RTNH_F_DEAD | RTNH_F_LINKDOWN);
1557 else
1558 mpls_ifup(dev, RTNH_F_DEAD);
1559 break;
1560 case NETDEV_CHANGE:
1561 flags = dev_get_flags(dev);
1562 if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1563 mpls_ifup(dev, RTNH_F_DEAD | RTNH_F_LINKDOWN);
1564 else
1565 mpls_ifdown(dev, event);
1566 break;
1567 case NETDEV_UNREGISTER:
1568 mpls_ifdown(dev, event);
1569 mdev = mpls_dev_get(dev);
1570 if (mdev) {
1571 mpls_dev_sysctl_unregister(dev, mdev);
1572 RCU_INIT_POINTER(dev->mpls_ptr, NULL);
1573 call_rcu(&mdev->rcu, mpls_dev_destroy_rcu);
1574 }
1575 break;
1576 case NETDEV_CHANGENAME:
1577 mdev = mpls_dev_get(dev);
1578 if (mdev) {
1579 int err;
1580
1581 mpls_dev_sysctl_unregister(dev, mdev);
1582 err = mpls_dev_sysctl_register(dev, mdev);
1583 if (err)
1584 return notifier_from_errno(err);
1585 }
1586 break;
1587 }
1588 return NOTIFY_OK;
1589 }
1590
1591 static struct notifier_block mpls_dev_notifier = {
1592 .notifier_call = mpls_dev_notify,
1593 };
1594
1595 static int nla_put_via(struct sk_buff *skb,
1596 u8 table, const void *addr, int alen)
1597 {
1598 static const int table_to_family[NEIGH_NR_TABLES + 1] = {
1599 AF_INET, AF_INET6, AF_DECnet, AF_PACKET,
1600 };
1601 struct nlattr *nla;
1602 struct rtvia *via;
1603 int family = AF_UNSPEC;
1604
1605 nla = nla_reserve(skb, RTA_VIA, alen + 2);
1606 if (!nla)
1607 return -EMSGSIZE;
1608
1609 if (table <= NEIGH_NR_TABLES)
1610 family = table_to_family[table];
1611
1612 via = nla_data(nla);
1613 via->rtvia_family = family;
1614 memcpy(via->rtvia_addr, addr, alen);
1615 return 0;
1616 }
1617
1618 int nla_put_labels(struct sk_buff *skb, int attrtype,
1619 u8 labels, const u32 label[])
1620 {
1621 struct nlattr *nla;
1622 struct mpls_shim_hdr *nla_label;
1623 bool bos;
1624 int i;
1625 nla = nla_reserve(skb, attrtype, labels*4);
1626 if (!nla)
1627 return -EMSGSIZE;
1628
1629 nla_label = nla_data(nla);
1630 bos = true;
1631 for (i = labels - 1; i >= 0; i--) {
1632 nla_label[i] = mpls_entry_encode(label[i], 0, 0, bos);
1633 bos = false;
1634 }
1635
1636 return 0;
1637 }
1638 EXPORT_SYMBOL_GPL(nla_put_labels);
1639
1640 int nla_get_labels(const struct nlattr *nla, u8 max_labels, u8 *labels,
1641 u32 label[], struct netlink_ext_ack *extack)
1642 {
1643 unsigned len = nla_len(nla);
1644 struct mpls_shim_hdr *nla_label;
1645 u8 nla_labels;
1646 bool bos;
1647 int i;
1648
1649 /* len needs to be an even multiple of 4 (the label size). Number
1650 * of labels is a u8 so check for overflow.
1651 */
1652 if (len & 3 || len / 4 > 255) {
1653 NL_SET_ERR_MSG_ATTR(extack, nla,
1654 "Invalid length for labels attribute");
1655 return -EINVAL;
1656 }
1657
1658 /* Limit the number of new labels allowed */
1659 nla_labels = len/4;
1660 if (nla_labels > max_labels) {
1661 NL_SET_ERR_MSG(extack, "Too many labels");
1662 return -EINVAL;
1663 }
1664
1665 /* when label == NULL, caller wants number of labels */
1666 if (!label)
1667 goto out;
1668
1669 nla_label = nla_data(nla);
1670 bos = true;
1671 for (i = nla_labels - 1; i >= 0; i--, bos = false) {
1672 struct mpls_entry_decoded dec;
1673 dec = mpls_entry_decode(nla_label + i);
1674
1675 /* Ensure the bottom of stack flag is properly set
1676 * and ttl and tc are both clear.
1677 */
1678 if (dec.ttl) {
1679 NL_SET_ERR_MSG_ATTR(extack, nla,
1680 "TTL in label must be 0");
1681 return -EINVAL;
1682 }
1683
1684 if (dec.tc) {
1685 NL_SET_ERR_MSG_ATTR(extack, nla,
1686 "Traffic class in label must be 0");
1687 return -EINVAL;
1688 }
1689
1690 if (dec.bos != bos) {
1691 NL_SET_BAD_ATTR(extack, nla);
1692 if (bos) {
1693 NL_SET_ERR_MSG(extack,
1694 "BOS bit must be set in first label");
1695 } else {
1696 NL_SET_ERR_MSG(extack,
1697 "BOS bit can only be set in first label");
1698 }
1699 return -EINVAL;
1700 }
1701
1702 switch (dec.label) {
1703 case MPLS_LABEL_IMPLNULL:
1704 /* RFC3032: This is a label that an LSR may
1705 * assign and distribute, but which never
1706 * actually appears in the encapsulation.
1707 */
1708 NL_SET_ERR_MSG_ATTR(extack, nla,
1709 "Implicit NULL Label (3) can not be used in encapsulation");
1710 return -EINVAL;
1711 }
1712
1713 label[i] = dec.label;
1714 }
1715 out:
1716 *labels = nla_labels;
1717 return 0;
1718 }
1719 EXPORT_SYMBOL_GPL(nla_get_labels);
1720
1721 static int rtm_to_route_config(struct sk_buff *skb,
1722 struct nlmsghdr *nlh,
1723 struct mpls_route_config *cfg,
1724 struct netlink_ext_ack *extack)
1725 {
1726 struct rtmsg *rtm;
1727 struct nlattr *tb[RTA_MAX+1];
1728 int index;
1729 int err;
1730
1731 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_mpls_policy,
1732 extack);
1733 if (err < 0)
1734 goto errout;
1735
1736 err = -EINVAL;
1737 rtm = nlmsg_data(nlh);
1738
1739 if (rtm->rtm_family != AF_MPLS) {
1740 NL_SET_ERR_MSG(extack, "Invalid address family in rtmsg");
1741 goto errout;
1742 }
1743 if (rtm->rtm_dst_len != 20) {
1744 NL_SET_ERR_MSG(extack, "rtm_dst_len must be 20 for MPLS");
1745 goto errout;
1746 }
1747 if (rtm->rtm_src_len != 0) {
1748 NL_SET_ERR_MSG(extack, "rtm_src_len must be 0 for MPLS");
1749 goto errout;
1750 }
1751 if (rtm->rtm_tos != 0) {
1752 NL_SET_ERR_MSG(extack, "rtm_tos must be 0 for MPLS");
1753 goto errout;
1754 }
1755 if (rtm->rtm_table != RT_TABLE_MAIN) {
1756 NL_SET_ERR_MSG(extack,
1757 "MPLS only supports the main route table");
1758 goto errout;
1759 }
1760 /* Any value is acceptable for rtm_protocol */
1761
1762 /* As mpls uses destination specific addresses
1763 * (or source specific address in the case of multicast)
1764 * all addresses have universal scope.
1765 */
1766 if (rtm->rtm_scope != RT_SCOPE_UNIVERSE) {
1767 NL_SET_ERR_MSG(extack,
1768 "Invalid route scope - MPLS only supports UNIVERSE");
1769 goto errout;
1770 }
1771 if (rtm->rtm_type != RTN_UNICAST) {
1772 NL_SET_ERR_MSG(extack,
1773 "Invalid route type - MPLS only supports UNICAST");
1774 goto errout;
1775 }
1776 if (rtm->rtm_flags != 0) {
1777 NL_SET_ERR_MSG(extack, "rtm_flags must be 0 for MPLS");
1778 goto errout;
1779 }
1780
1781 cfg->rc_label = LABEL_NOT_SPECIFIED;
1782 cfg->rc_protocol = rtm->rtm_protocol;
1783 cfg->rc_via_table = MPLS_NEIGH_TABLE_UNSPEC;
1784 cfg->rc_ttl_propagate = MPLS_TTL_PROP_DEFAULT;
1785 cfg->rc_nlflags = nlh->nlmsg_flags;
1786 cfg->rc_nlinfo.portid = NETLINK_CB(skb).portid;
1787 cfg->rc_nlinfo.nlh = nlh;
1788 cfg->rc_nlinfo.nl_net = sock_net(skb->sk);
1789
1790 for (index = 0; index <= RTA_MAX; index++) {
1791 struct nlattr *nla = tb[index];
1792 if (!nla)
1793 continue;
1794
1795 switch (index) {
1796 case RTA_OIF:
1797 cfg->rc_ifindex = nla_get_u32(nla);
1798 break;
1799 case RTA_NEWDST:
1800 if (nla_get_labels(nla, MAX_NEW_LABELS,
1801 &cfg->rc_output_labels,
1802 cfg->rc_output_label, extack))
1803 goto errout;
1804 break;
1805 case RTA_DST:
1806 {
1807 u8 label_count;
1808 if (nla_get_labels(nla, 1, &label_count,
1809 &cfg->rc_label, extack))
1810 goto errout;
1811
1812 if (!mpls_label_ok(cfg->rc_nlinfo.nl_net,
1813 cfg->rc_label, extack))
1814 goto errout;
1815 break;
1816 }
1817 case RTA_VIA:
1818 {
1819 if (nla_get_via(nla, &cfg->rc_via_alen,
1820 &cfg->rc_via_table, cfg->rc_via,
1821 extack))
1822 goto errout;
1823 break;
1824 }
1825 case RTA_MULTIPATH:
1826 {
1827 cfg->rc_mp = nla_data(nla);
1828 cfg->rc_mp_len = nla_len(nla);
1829 break;
1830 }
1831 case RTA_TTL_PROPAGATE:
1832 {
1833 u8 ttl_propagate = nla_get_u8(nla);
1834
1835 if (ttl_propagate > 1) {
1836 NL_SET_ERR_MSG_ATTR(extack, nla,
1837 "RTA_TTL_PROPAGATE can only be 0 or 1");
1838 goto errout;
1839 }
1840 cfg->rc_ttl_propagate = ttl_propagate ?
1841 MPLS_TTL_PROP_ENABLED :
1842 MPLS_TTL_PROP_DISABLED;
1843 break;
1844 }
1845 default:
1846 NL_SET_ERR_MSG_ATTR(extack, nla, "Unknown attribute");
1847 /* Unsupported attribute */
1848 goto errout;
1849 }
1850 }
1851
1852 err = 0;
1853 errout:
1854 return err;
1855 }
1856
1857 static int mpls_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
1858 struct netlink_ext_ack *extack)
1859 {
1860 struct mpls_route_config *cfg;
1861 int err;
1862
1863 cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
1864 if (!cfg)
1865 return -ENOMEM;
1866
1867 err = rtm_to_route_config(skb, nlh, cfg, extack);
1868 if (err < 0)
1869 goto out;
1870
1871 err = mpls_route_del(cfg, extack);
1872 out:
1873 kfree(cfg);
1874
1875 return err;
1876 }
1877
1878
1879 static int mpls_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
1880 struct netlink_ext_ack *extack)
1881 {
1882 struct mpls_route_config *cfg;
1883 int err;
1884
1885 cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
1886 if (!cfg)
1887 return -ENOMEM;
1888
1889 err = rtm_to_route_config(skb, nlh, cfg, extack);
1890 if (err < 0)
1891 goto out;
1892
1893 err = mpls_route_add(cfg, extack);
1894 out:
1895 kfree(cfg);
1896
1897 return err;
1898 }
1899
1900 static int mpls_dump_route(struct sk_buff *skb, u32 portid, u32 seq, int event,
1901 u32 label, struct mpls_route *rt, int flags)
1902 {
1903 struct net_device *dev;
1904 struct nlmsghdr *nlh;
1905 struct rtmsg *rtm;
1906
1907 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), flags);
1908 if (nlh == NULL)
1909 return -EMSGSIZE;
1910
1911 rtm = nlmsg_data(nlh);
1912 rtm->rtm_family = AF_MPLS;
1913 rtm->rtm_dst_len = 20;
1914 rtm->rtm_src_len = 0;
1915 rtm->rtm_tos = 0;
1916 rtm->rtm_table = RT_TABLE_MAIN;
1917 rtm->rtm_protocol = rt->rt_protocol;
1918 rtm->rtm_scope = RT_SCOPE_UNIVERSE;
1919 rtm->rtm_type = RTN_UNICAST;
1920 rtm->rtm_flags = 0;
1921
1922 if (nla_put_labels(skb, RTA_DST, 1, &label))
1923 goto nla_put_failure;
1924
1925 if (rt->rt_ttl_propagate != MPLS_TTL_PROP_DEFAULT) {
1926 bool ttl_propagate =
1927 rt->rt_ttl_propagate == MPLS_TTL_PROP_ENABLED;
1928
1929 if (nla_put_u8(skb, RTA_TTL_PROPAGATE,
1930 ttl_propagate))
1931 goto nla_put_failure;
1932 }
1933 if (rt->rt_nhn == 1) {
1934 const struct mpls_nh *nh = rt->rt_nh;
1935
1936 if (nh->nh_labels &&
1937 nla_put_labels(skb, RTA_NEWDST, nh->nh_labels,
1938 nh->nh_label))
1939 goto nla_put_failure;
1940 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC &&
1941 nla_put_via(skb, nh->nh_via_table, mpls_nh_via(rt, nh),
1942 nh->nh_via_alen))
1943 goto nla_put_failure;
1944 dev = rtnl_dereference(nh->nh_dev);
1945 if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex))
1946 goto nla_put_failure;
1947 if (nh->nh_flags & RTNH_F_LINKDOWN)
1948 rtm->rtm_flags |= RTNH_F_LINKDOWN;
1949 if (nh->nh_flags & RTNH_F_DEAD)
1950 rtm->rtm_flags |= RTNH_F_DEAD;
1951 } else {
1952 struct rtnexthop *rtnh;
1953 struct nlattr *mp;
1954 u8 linkdown = 0;
1955 u8 dead = 0;
1956
1957 mp = nla_nest_start(skb, RTA_MULTIPATH);
1958 if (!mp)
1959 goto nla_put_failure;
1960
1961 for_nexthops(rt) {
1962 dev = rtnl_dereference(nh->nh_dev);
1963 if (!dev)
1964 continue;
1965
1966 rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh));
1967 if (!rtnh)
1968 goto nla_put_failure;
1969
1970 rtnh->rtnh_ifindex = dev->ifindex;
1971 if (nh->nh_flags & RTNH_F_LINKDOWN) {
1972 rtnh->rtnh_flags |= RTNH_F_LINKDOWN;
1973 linkdown++;
1974 }
1975 if (nh->nh_flags & RTNH_F_DEAD) {
1976 rtnh->rtnh_flags |= RTNH_F_DEAD;
1977 dead++;
1978 }
1979
1980 if (nh->nh_labels && nla_put_labels(skb, RTA_NEWDST,
1981 nh->nh_labels,
1982 nh->nh_label))
1983 goto nla_put_failure;
1984 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC &&
1985 nla_put_via(skb, nh->nh_via_table,
1986 mpls_nh_via(rt, nh),
1987 nh->nh_via_alen))
1988 goto nla_put_failure;
1989
1990 /* length of rtnetlink header + attributes */
1991 rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *)rtnh;
1992 } endfor_nexthops(rt);
1993
1994 if (linkdown == rt->rt_nhn)
1995 rtm->rtm_flags |= RTNH_F_LINKDOWN;
1996 if (dead == rt->rt_nhn)
1997 rtm->rtm_flags |= RTNH_F_DEAD;
1998
1999 nla_nest_end(skb, mp);
2000 }
2001
2002 nlmsg_end(skb, nlh);
2003 return 0;
2004
2005 nla_put_failure:
2006 nlmsg_cancel(skb, nlh);
2007 return -EMSGSIZE;
2008 }
2009
2010 static int mpls_dump_routes(struct sk_buff *skb, struct netlink_callback *cb)
2011 {
2012 struct net *net = sock_net(skb->sk);
2013 struct mpls_route __rcu **platform_label;
2014 size_t platform_labels;
2015 unsigned int index;
2016
2017 ASSERT_RTNL();
2018
2019 index = cb->args[0];
2020 if (index < MPLS_LABEL_FIRST_UNRESERVED)
2021 index = MPLS_LABEL_FIRST_UNRESERVED;
2022
2023 platform_label = rtnl_dereference(net->mpls.platform_label);
2024 platform_labels = net->mpls.platform_labels;
2025 for (; index < platform_labels; index++) {
2026 struct mpls_route *rt;
2027 rt = rtnl_dereference(platform_label[index]);
2028 if (!rt)
2029 continue;
2030
2031 if (mpls_dump_route(skb, NETLINK_CB(cb->skb).portid,
2032 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
2033 index, rt, NLM_F_MULTI) < 0)
2034 break;
2035 }
2036 cb->args[0] = index;
2037
2038 return skb->len;
2039 }
2040
2041 static inline size_t lfib_nlmsg_size(struct mpls_route *rt)
2042 {
2043 size_t payload =
2044 NLMSG_ALIGN(sizeof(struct rtmsg))
2045 + nla_total_size(4) /* RTA_DST */
2046 + nla_total_size(1); /* RTA_TTL_PROPAGATE */
2047
2048 if (rt->rt_nhn == 1) {
2049 struct mpls_nh *nh = rt->rt_nh;
2050
2051 if (nh->nh_dev)
2052 payload += nla_total_size(4); /* RTA_OIF */
2053 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC) /* RTA_VIA */
2054 payload += nla_total_size(2 + nh->nh_via_alen);
2055 if (nh->nh_labels) /* RTA_NEWDST */
2056 payload += nla_total_size(nh->nh_labels * 4);
2057 } else {
2058 /* each nexthop is packed in an attribute */
2059 size_t nhsize = 0;
2060
2061 for_nexthops(rt) {
2062 if (!rtnl_dereference(nh->nh_dev))
2063 continue;
2064 nhsize += nla_total_size(sizeof(struct rtnexthop));
2065 /* RTA_VIA */
2066 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC)
2067 nhsize += nla_total_size(2 + nh->nh_via_alen);
2068 if (nh->nh_labels)
2069 nhsize += nla_total_size(nh->nh_labels * 4);
2070 } endfor_nexthops(rt);
2071 /* nested attribute */
2072 payload += nla_total_size(nhsize);
2073 }
2074
2075 return payload;
2076 }
2077
2078 static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt,
2079 struct nlmsghdr *nlh, struct net *net, u32 portid,
2080 unsigned int nlm_flags)
2081 {
2082 struct sk_buff *skb;
2083 u32 seq = nlh ? nlh->nlmsg_seq : 0;
2084 int err = -ENOBUFS;
2085
2086 skb = nlmsg_new(lfib_nlmsg_size(rt), GFP_KERNEL);
2087 if (skb == NULL)
2088 goto errout;
2089
2090 err = mpls_dump_route(skb, portid, seq, event, label, rt, nlm_flags);
2091 if (err < 0) {
2092 /* -EMSGSIZE implies BUG in lfib_nlmsg_size */
2093 WARN_ON(err == -EMSGSIZE);
2094 kfree_skb(skb);
2095 goto errout;
2096 }
2097 rtnl_notify(skb, net, portid, RTNLGRP_MPLS_ROUTE, nlh, GFP_KERNEL);
2098
2099 return;
2100 errout:
2101 if (err < 0)
2102 rtnl_set_sk_err(net, RTNLGRP_MPLS_ROUTE, err);
2103 }
2104
2105 static int mpls_getroute(struct sk_buff *in_skb, struct nlmsghdr *in_nlh,
2106 struct netlink_ext_ack *extack)
2107 {
2108 struct net *net = sock_net(in_skb->sk);
2109 u32 portid = NETLINK_CB(in_skb).portid;
2110 u32 in_label = LABEL_NOT_SPECIFIED;
2111 struct nlattr *tb[RTA_MAX + 1];
2112 u32 labels[MAX_NEW_LABELS];
2113 struct mpls_shim_hdr *hdr;
2114 unsigned int hdr_size = 0;
2115 struct net_device *dev;
2116 struct mpls_route *rt;
2117 struct rtmsg *rtm, *r;
2118 struct nlmsghdr *nlh;
2119 struct sk_buff *skb;
2120 struct mpls_nh *nh;
2121 u8 n_labels;
2122 int err;
2123
2124 err = nlmsg_parse(in_nlh, sizeof(*rtm), tb, RTA_MAX,
2125 rtm_mpls_policy, extack);
2126 if (err < 0)
2127 goto errout;
2128
2129 rtm = nlmsg_data(in_nlh);
2130
2131 if (tb[RTA_DST]) {
2132 u8 label_count;
2133
2134 if (nla_get_labels(tb[RTA_DST], 1, &label_count,
2135 &in_label, extack)) {
2136 err = -EINVAL;
2137 goto errout;
2138 }
2139
2140 if (!mpls_label_ok(net, in_label, extack)) {
2141 err = -EINVAL;
2142 goto errout;
2143 }
2144 }
2145
2146 rt = mpls_route_input_rcu(net, in_label);
2147 if (!rt) {
2148 err = -ENETUNREACH;
2149 goto errout;
2150 }
2151
2152 if (rtm->rtm_flags & RTM_F_FIB_MATCH) {
2153 skb = nlmsg_new(lfib_nlmsg_size(rt), GFP_KERNEL);
2154 if (!skb) {
2155 err = -ENOBUFS;
2156 goto errout;
2157 }
2158
2159 err = mpls_dump_route(skb, portid, in_nlh->nlmsg_seq,
2160 RTM_NEWROUTE, in_label, rt, 0);
2161 if (err < 0) {
2162 /* -EMSGSIZE implies BUG in lfib_nlmsg_size */
2163 WARN_ON(err == -EMSGSIZE);
2164 goto errout_free;
2165 }
2166
2167 return rtnl_unicast(skb, net, portid);
2168 }
2169
2170 if (tb[RTA_NEWDST]) {
2171 if (nla_get_labels(tb[RTA_NEWDST], MAX_NEW_LABELS, &n_labels,
2172 labels, extack) != 0) {
2173 err = -EINVAL;
2174 goto errout;
2175 }
2176
2177 hdr_size = n_labels * sizeof(struct mpls_shim_hdr);
2178 }
2179
2180 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2181 if (!skb) {
2182 err = -ENOBUFS;
2183 goto errout;
2184 }
2185
2186 skb->protocol = htons(ETH_P_MPLS_UC);
2187
2188 if (hdr_size) {
2189 bool bos;
2190 int i;
2191
2192 if (skb_cow(skb, hdr_size)) {
2193 err = -ENOBUFS;
2194 goto errout_free;
2195 }
2196
2197 skb_reserve(skb, hdr_size);
2198 skb_push(skb, hdr_size);
2199 skb_reset_network_header(skb);
2200
2201 /* Push new labels */
2202 hdr = mpls_hdr(skb);
2203 bos = true;
2204 for (i = n_labels - 1; i >= 0; i--) {
2205 hdr[i] = mpls_entry_encode(labels[i],
2206 1, 0, bos);
2207 bos = false;
2208 }
2209 }
2210
2211 nh = mpls_select_multipath(rt, skb);
2212 if (!nh) {
2213 err = -ENETUNREACH;
2214 goto errout_free;
2215 }
2216
2217 if (hdr_size) {
2218 skb_pull(skb, hdr_size);
2219 skb_reset_network_header(skb);
2220 }
2221
2222 nlh = nlmsg_put(skb, portid, in_nlh->nlmsg_seq,
2223 RTM_NEWROUTE, sizeof(*r), 0);
2224 if (!nlh) {
2225 err = -EMSGSIZE;
2226 goto errout_free;
2227 }
2228
2229 r = nlmsg_data(nlh);
2230 r->rtm_family = AF_MPLS;
2231 r->rtm_dst_len = 20;
2232 r->rtm_src_len = 0;
2233 r->rtm_table = RT_TABLE_MAIN;
2234 r->rtm_type = RTN_UNICAST;
2235 r->rtm_scope = RT_SCOPE_UNIVERSE;
2236 r->rtm_protocol = rt->rt_protocol;
2237 r->rtm_flags = 0;
2238
2239 if (nla_put_labels(skb, RTA_DST, 1, &in_label))
2240 goto nla_put_failure;
2241
2242 if (nh->nh_labels &&
2243 nla_put_labels(skb, RTA_NEWDST, nh->nh_labels,
2244 nh->nh_label))
2245 goto nla_put_failure;
2246
2247 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC &&
2248 nla_put_via(skb, nh->nh_via_table, mpls_nh_via(rt, nh),
2249 nh->nh_via_alen))
2250 goto nla_put_failure;
2251 dev = rtnl_dereference(nh->nh_dev);
2252 if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex))
2253 goto nla_put_failure;
2254
2255 nlmsg_end(skb, nlh);
2256
2257 err = rtnl_unicast(skb, net, portid);
2258 errout:
2259 return err;
2260
2261 nla_put_failure:
2262 nlmsg_cancel(skb, nlh);
2263 err = -EMSGSIZE;
2264 errout_free:
2265 kfree_skb(skb);
2266 return err;
2267 }
2268
2269 static int resize_platform_label_table(struct net *net, size_t limit)
2270 {
2271 size_t size = sizeof(struct mpls_route *) * limit;
2272 size_t old_limit;
2273 size_t cp_size;
2274 struct mpls_route __rcu **labels = NULL, **old;
2275 struct mpls_route *rt0 = NULL, *rt2 = NULL;
2276 unsigned index;
2277
2278 if (size) {
2279 labels = kvzalloc(size, GFP_KERNEL);
2280 if (!labels)
2281 goto nolabels;
2282 }
2283
2284 /* In case the predefined labels need to be populated */
2285 if (limit > MPLS_LABEL_IPV4NULL) {
2286 struct net_device *lo = net->loopback_dev;
2287 rt0 = mpls_rt_alloc(1, lo->addr_len, 0);
2288 if (IS_ERR(rt0))
2289 goto nort0;
2290 RCU_INIT_POINTER(rt0->rt_nh->nh_dev, lo);
2291 rt0->rt_protocol = RTPROT_KERNEL;
2292 rt0->rt_payload_type = MPT_IPV4;
2293 rt0->rt_ttl_propagate = MPLS_TTL_PROP_DEFAULT;
2294 rt0->rt_nh->nh_via_table = NEIGH_LINK_TABLE;
2295 rt0->rt_nh->nh_via_alen = lo->addr_len;
2296 memcpy(__mpls_nh_via(rt0, rt0->rt_nh), lo->dev_addr,
2297 lo->addr_len);
2298 }
2299 if (limit > MPLS_LABEL_IPV6NULL) {
2300 struct net_device *lo = net->loopback_dev;
2301 rt2 = mpls_rt_alloc(1, lo->addr_len, 0);
2302 if (IS_ERR(rt2))
2303 goto nort2;
2304 RCU_INIT_POINTER(rt2->rt_nh->nh_dev, lo);
2305 rt2->rt_protocol = RTPROT_KERNEL;
2306 rt2->rt_payload_type = MPT_IPV6;
2307 rt2->rt_ttl_propagate = MPLS_TTL_PROP_DEFAULT;
2308 rt2->rt_nh->nh_via_table = NEIGH_LINK_TABLE;
2309 rt2->rt_nh->nh_via_alen = lo->addr_len;
2310 memcpy(__mpls_nh_via(rt2, rt2->rt_nh), lo->dev_addr,
2311 lo->addr_len);
2312 }
2313
2314 rtnl_lock();
2315 /* Remember the original table */
2316 old = rtnl_dereference(net->mpls.platform_label);
2317 old_limit = net->mpls.platform_labels;
2318
2319 /* Free any labels beyond the new table */
2320 for (index = limit; index < old_limit; index++)
2321 mpls_route_update(net, index, NULL, NULL);
2322
2323 /* Copy over the old labels */
2324 cp_size = size;
2325 if (old_limit < limit)
2326 cp_size = old_limit * sizeof(struct mpls_route *);
2327
2328 memcpy(labels, old, cp_size);
2329
2330 /* If needed set the predefined labels */
2331 if ((old_limit <= MPLS_LABEL_IPV6NULL) &&
2332 (limit > MPLS_LABEL_IPV6NULL)) {
2333 RCU_INIT_POINTER(labels[MPLS_LABEL_IPV6NULL], rt2);
2334 rt2 = NULL;
2335 }
2336
2337 if ((old_limit <= MPLS_LABEL_IPV4NULL) &&
2338 (limit > MPLS_LABEL_IPV4NULL)) {
2339 RCU_INIT_POINTER(labels[MPLS_LABEL_IPV4NULL], rt0);
2340 rt0 = NULL;
2341 }
2342
2343 /* Update the global pointers */
2344 net->mpls.platform_labels = limit;
2345 rcu_assign_pointer(net->mpls.platform_label, labels);
2346
2347 rtnl_unlock();
2348
2349 mpls_rt_free(rt2);
2350 mpls_rt_free(rt0);
2351
2352 if (old) {
2353 synchronize_rcu();
2354 kvfree(old);
2355 }
2356 return 0;
2357
2358 nort2:
2359 mpls_rt_free(rt0);
2360 nort0:
2361 kvfree(labels);
2362 nolabels:
2363 return -ENOMEM;
2364 }
2365
2366 static int mpls_platform_labels(struct ctl_table *table, int write,
2367 void __user *buffer, size_t *lenp, loff_t *ppos)
2368 {
2369 struct net *net = table->data;
2370 int platform_labels = net->mpls.platform_labels;
2371 int ret;
2372 struct ctl_table tmp = {
2373 .procname = table->procname,
2374 .data = &platform_labels,
2375 .maxlen = sizeof(int),
2376 .mode = table->mode,
2377 .extra1 = &zero,
2378 .extra2 = &label_limit,
2379 };
2380
2381 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
2382
2383 if (write && ret == 0)
2384 ret = resize_platform_label_table(net, platform_labels);
2385
2386 return ret;
2387 }
2388
2389 #define MPLS_NS_SYSCTL_OFFSET(field) \
2390 (&((struct net *)0)->field)
2391
2392 static const struct ctl_table mpls_table[] = {
2393 {
2394 .procname = "platform_labels",
2395 .data = NULL,
2396 .maxlen = sizeof(int),
2397 .mode = 0644,
2398 .proc_handler = mpls_platform_labels,
2399 },
2400 {
2401 .procname = "ip_ttl_propagate",
2402 .data = MPLS_NS_SYSCTL_OFFSET(mpls.ip_ttl_propagate),
2403 .maxlen = sizeof(int),
2404 .mode = 0644,
2405 .proc_handler = proc_dointvec_minmax,
2406 .extra1 = &zero,
2407 .extra2 = &one,
2408 },
2409 {
2410 .procname = "default_ttl",
2411 .data = MPLS_NS_SYSCTL_OFFSET(mpls.default_ttl),
2412 .maxlen = sizeof(int),
2413 .mode = 0644,
2414 .proc_handler = proc_dointvec_minmax,
2415 .extra1 = &one,
2416 .extra2 = &ttl_max,
2417 },
2418 { }
2419 };
2420
2421 static int mpls_net_init(struct net *net)
2422 {
2423 struct ctl_table *table;
2424 int i;
2425
2426 net->mpls.platform_labels = 0;
2427 net->mpls.platform_label = NULL;
2428 net->mpls.ip_ttl_propagate = 1;
2429 net->mpls.default_ttl = 255;
2430
2431 table = kmemdup(mpls_table, sizeof(mpls_table), GFP_KERNEL);
2432 if (table == NULL)
2433 return -ENOMEM;
2434
2435 /* Table data contains only offsets relative to the base of
2436 * the mdev at this point, so make them absolute.
2437 */
2438 for (i = 0; i < ARRAY_SIZE(mpls_table) - 1; i++)
2439 table[i].data = (char *)net + (uintptr_t)table[i].data;
2440
2441 net->mpls.ctl = register_net_sysctl(net, "net/mpls", table);
2442 if (net->mpls.ctl == NULL) {
2443 kfree(table);
2444 return -ENOMEM;
2445 }
2446
2447 return 0;
2448 }
2449
2450 static void mpls_net_exit(struct net *net)
2451 {
2452 struct mpls_route __rcu **platform_label;
2453 size_t platform_labels;
2454 struct ctl_table *table;
2455 unsigned int index;
2456
2457 table = net->mpls.ctl->ctl_table_arg;
2458 unregister_net_sysctl_table(net->mpls.ctl);
2459 kfree(table);
2460
2461 /* An rcu grace period has passed since there was a device in
2462 * the network namespace (and thus the last in flight packet)
2463 * left this network namespace. This is because
2464 * unregister_netdevice_many and netdev_run_todo has completed
2465 * for each network device that was in this network namespace.
2466 *
2467 * As such no additional rcu synchronization is necessary when
2468 * freeing the platform_label table.
2469 */
2470 rtnl_lock();
2471 platform_label = rtnl_dereference(net->mpls.platform_label);
2472 platform_labels = net->mpls.platform_labels;
2473 for (index = 0; index < platform_labels; index++) {
2474 struct mpls_route *rt = rtnl_dereference(platform_label[index]);
2475 RCU_INIT_POINTER(platform_label[index], NULL);
2476 mpls_notify_route(net, index, rt, NULL, NULL);
2477 mpls_rt_free(rt);
2478 }
2479 rtnl_unlock();
2480
2481 kvfree(platform_label);
2482 }
2483
2484 static struct pernet_operations mpls_net_ops = {
2485 .init = mpls_net_init,
2486 .exit = mpls_net_exit,
2487 };
2488
2489 static struct rtnl_af_ops mpls_af_ops __read_mostly = {
2490 .family = AF_MPLS,
2491 .fill_stats_af = mpls_fill_stats_af,
2492 .get_stats_af_size = mpls_get_stats_af_size,
2493 };
2494
2495 static int __init mpls_init(void)
2496 {
2497 int err;
2498
2499 BUILD_BUG_ON(sizeof(struct mpls_shim_hdr) != 4);
2500
2501 err = register_pernet_subsys(&mpls_net_ops);
2502 if (err)
2503 goto out;
2504
2505 err = register_netdevice_notifier(&mpls_dev_notifier);
2506 if (err)
2507 goto out_unregister_pernet;
2508
2509 dev_add_pack(&mpls_packet_type);
2510
2511 rtnl_af_register(&mpls_af_ops);
2512
2513 rtnl_register(PF_MPLS, RTM_NEWROUTE, mpls_rtm_newroute, NULL, 0);
2514 rtnl_register(PF_MPLS, RTM_DELROUTE, mpls_rtm_delroute, NULL, 0);
2515 rtnl_register(PF_MPLS, RTM_GETROUTE, mpls_getroute, mpls_dump_routes,
2516 0);
2517 rtnl_register(PF_MPLS, RTM_GETNETCONF, mpls_netconf_get_devconf,
2518 mpls_netconf_dump_devconf, 0);
2519 err = ipgre_tunnel_encap_add_mpls_ops();
2520 if (err)
2521 pr_err("Can't add mpls over gre tunnel ops\n");
2522
2523 err = 0;
2524 out:
2525 return err;
2526
2527 out_unregister_pernet:
2528 unregister_pernet_subsys(&mpls_net_ops);
2529 goto out;
2530 }
2531 module_init(mpls_init);
2532
2533 static void __exit mpls_exit(void)
2534 {
2535 rtnl_unregister_all(PF_MPLS);
2536 rtnl_af_unregister(&mpls_af_ops);
2537 dev_remove_pack(&mpls_packet_type);
2538 unregister_netdevice_notifier(&mpls_dev_notifier);
2539 unregister_pernet_subsys(&mpls_net_ops);
2540 ipgre_tunnel_encap_del_mpls_ops();
2541 }
2542 module_exit(mpls_exit);
2543
2544 MODULE_DESCRIPTION("MultiProtocol Label Switching");
2545 MODULE_LICENSE("GPL v2");
2546 MODULE_ALIAS_NETPROTO(PF_MPLS);
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