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mpls, nospec: Sanitize array index in mpls_label_ok()
[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/nospec.h>
12 #include <linux/vmalloc.h>
13 #include <linux/percpu.h>
14 #include <net/ip.h>
15 #include <net/dst.h>
16 #include <net/sock.h>
17 #include <net/arp.h>
18 #include <net/ip_fib.h>
19 #include <net/netevent.h>
20 #include <net/ip_tunnels.h>
21 #include <net/netns/generic.h>
22 #if IS_ENABLED(CONFIG_IPV6)
23 #include <net/ipv6.h>
24 #endif
25 #include <net/addrconf.h>
26 #include <net/nexthop.h>
27 #include "internal.h"
28
29 /* max memory we will use for mpls_route */
30 #define MAX_MPLS_ROUTE_MEM 4096
31
32 /* Maximum number of labels to look ahead at when selecting a path of
33 * a multipath route
34 */
35 #define MAX_MP_SELECT_LABELS 4
36
37 #define MPLS_NEIGH_TABLE_UNSPEC (NEIGH_LINK_TABLE + 1)
38
39 static int zero = 0;
40 static int one = 1;
41 static int label_limit = (1 << 20) - 1;
42 static int ttl_max = 255;
43
44 #if IS_ENABLED(CONFIG_NET_IP_TUNNEL)
45 static size_t ipgre_mpls_encap_hlen(struct ip_tunnel_encap *e)
46 {
47 return sizeof(struct mpls_shim_hdr);
48 }
49
50 static const struct ip_tunnel_encap_ops mpls_iptun_ops = {
51 .encap_hlen = ipgre_mpls_encap_hlen,
52 };
53
54 static int ipgre_tunnel_encap_add_mpls_ops(void)
55 {
56 return ip_tunnel_encap_add_ops(&mpls_iptun_ops, TUNNEL_ENCAP_MPLS);
57 }
58
59 static void ipgre_tunnel_encap_del_mpls_ops(void)
60 {
61 ip_tunnel_encap_del_ops(&mpls_iptun_ops, TUNNEL_ENCAP_MPLS);
62 }
63 #else
64 static int ipgre_tunnel_encap_add_mpls_ops(void)
65 {
66 return 0;
67 }
68
69 static void ipgre_tunnel_encap_del_mpls_ops(void)
70 {
71 }
72 #endif
73
74 static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt,
75 struct nlmsghdr *nlh, struct net *net, u32 portid,
76 unsigned int nlm_flags);
77
78 static struct mpls_route *mpls_route_input_rcu(struct net *net, unsigned index)
79 {
80 struct mpls_route *rt = NULL;
81
82 if (index < net->mpls.platform_labels) {
83 struct mpls_route __rcu **platform_label =
84 rcu_dereference(net->mpls.platform_label);
85 rt = rcu_dereference(platform_label[index]);
86 }
87 return rt;
88 }
89
90 bool mpls_output_possible(const struct net_device *dev)
91 {
92 return dev && (dev->flags & IFF_UP) && netif_carrier_ok(dev);
93 }
94 EXPORT_SYMBOL_GPL(mpls_output_possible);
95
96 static u8 *__mpls_nh_via(struct mpls_route *rt, struct mpls_nh *nh)
97 {
98 return (u8 *)nh + rt->rt_via_offset;
99 }
100
101 static const u8 *mpls_nh_via(const struct mpls_route *rt,
102 const struct mpls_nh *nh)
103 {
104 return __mpls_nh_via((struct mpls_route *)rt, (struct mpls_nh *)nh);
105 }
106
107 static unsigned int mpls_nh_header_size(const struct mpls_nh *nh)
108 {
109 /* The size of the layer 2.5 labels to be added for this route */
110 return nh->nh_labels * sizeof(struct mpls_shim_hdr);
111 }
112
113 unsigned int mpls_dev_mtu(const struct net_device *dev)
114 {
115 /* The amount of data the layer 2 frame can hold */
116 return dev->mtu;
117 }
118 EXPORT_SYMBOL_GPL(mpls_dev_mtu);
119
120 bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu)
121 {
122 if (skb->len <= mtu)
123 return false;
124
125 if (skb_is_gso(skb) && skb_gso_validate_mtu(skb, mtu))
126 return false;
127
128 return true;
129 }
130 EXPORT_SYMBOL_GPL(mpls_pkt_too_big);
131
132 void mpls_stats_inc_outucastpkts(struct net_device *dev,
133 const struct sk_buff *skb)
134 {
135 struct mpls_dev *mdev;
136
137 if (skb->protocol == htons(ETH_P_MPLS_UC)) {
138 mdev = mpls_dev_get(dev);
139 if (mdev)
140 MPLS_INC_STATS_LEN(mdev, skb->len,
141 tx_packets,
142 tx_bytes);
143 } else if (skb->protocol == htons(ETH_P_IP)) {
144 IP_UPD_PO_STATS(dev_net(dev), IPSTATS_MIB_OUT, skb->len);
145 #if IS_ENABLED(CONFIG_IPV6)
146 } else if (skb->protocol == htons(ETH_P_IPV6)) {
147 struct inet6_dev *in6dev = __in6_dev_get(dev);
148
149 if (in6dev)
150 IP6_UPD_PO_STATS(dev_net(dev), in6dev,
151 IPSTATS_MIB_OUT, skb->len);
152 #endif
153 }
154 }
155 EXPORT_SYMBOL_GPL(mpls_stats_inc_outucastpkts);
156
157 static u32 mpls_multipath_hash(struct mpls_route *rt, struct sk_buff *skb)
158 {
159 struct mpls_entry_decoded dec;
160 unsigned int mpls_hdr_len = 0;
161 struct mpls_shim_hdr *hdr;
162 bool eli_seen = false;
163 int label_index;
164 u32 hash = 0;
165
166 for (label_index = 0; label_index < MAX_MP_SELECT_LABELS;
167 label_index++) {
168 mpls_hdr_len += sizeof(*hdr);
169 if (!pskb_may_pull(skb, mpls_hdr_len))
170 break;
171
172 /* Read and decode the current label */
173 hdr = mpls_hdr(skb) + label_index;
174 dec = mpls_entry_decode(hdr);
175
176 /* RFC6790 - reserved labels MUST NOT be used as keys
177 * for the load-balancing function
178 */
179 if (likely(dec.label >= MPLS_LABEL_FIRST_UNRESERVED)) {
180 hash = jhash_1word(dec.label, hash);
181
182 /* The entropy label follows the entropy label
183 * indicator, so this means that the entropy
184 * label was just added to the hash - no need to
185 * go any deeper either in the label stack or in the
186 * payload
187 */
188 if (eli_seen)
189 break;
190 } else if (dec.label == MPLS_LABEL_ENTROPY) {
191 eli_seen = true;
192 }
193
194 if (!dec.bos)
195 continue;
196
197 /* found bottom label; does skb have room for a header? */
198 if (pskb_may_pull(skb, mpls_hdr_len + sizeof(struct iphdr))) {
199 const struct iphdr *v4hdr;
200
201 v4hdr = (const struct iphdr *)(hdr + 1);
202 if (v4hdr->version == 4) {
203 hash = jhash_3words(ntohl(v4hdr->saddr),
204 ntohl(v4hdr->daddr),
205 v4hdr->protocol, hash);
206 } else if (v4hdr->version == 6 &&
207 pskb_may_pull(skb, mpls_hdr_len +
208 sizeof(struct ipv6hdr))) {
209 const struct ipv6hdr *v6hdr;
210
211 v6hdr = (const struct ipv6hdr *)(hdr + 1);
212 hash = __ipv6_addr_jhash(&v6hdr->saddr, hash);
213 hash = __ipv6_addr_jhash(&v6hdr->daddr, hash);
214 hash = jhash_1word(v6hdr->nexthdr, hash);
215 }
216 }
217
218 break;
219 }
220
221 return hash;
222 }
223
224 static struct mpls_nh *mpls_get_nexthop(struct mpls_route *rt, u8 index)
225 {
226 return (struct mpls_nh *)((u8 *)rt->rt_nh + index * rt->rt_nh_size);
227 }
228
229 /* number of alive nexthops (rt->rt_nhn_alive) and the flags for
230 * a next hop (nh->nh_flags) are modified by netdev event handlers.
231 * Since those fields can change at any moment, use READ_ONCE to
232 * access both.
233 */
234 static struct mpls_nh *mpls_select_multipath(struct mpls_route *rt,
235 struct sk_buff *skb)
236 {
237 u32 hash = 0;
238 int nh_index = 0;
239 int n = 0;
240 u8 alive;
241
242 /* No need to look further into packet if there's only
243 * one path
244 */
245 if (rt->rt_nhn == 1)
246 return rt->rt_nh;
247
248 alive = READ_ONCE(rt->rt_nhn_alive);
249 if (alive == 0)
250 return NULL;
251
252 hash = mpls_multipath_hash(rt, skb);
253 nh_index = hash % alive;
254 if (alive == rt->rt_nhn)
255 goto out;
256 for_nexthops(rt) {
257 unsigned int nh_flags = READ_ONCE(nh->nh_flags);
258
259 if (nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN))
260 continue;
261 if (n == nh_index)
262 return nh;
263 n++;
264 } endfor_nexthops(rt);
265
266 out:
267 return mpls_get_nexthop(rt, nh_index);
268 }
269
270 static bool mpls_egress(struct net *net, struct mpls_route *rt,
271 struct sk_buff *skb, struct mpls_entry_decoded dec)
272 {
273 enum mpls_payload_type payload_type;
274 bool success = false;
275
276 /* The IPv4 code below accesses through the IPv4 header
277 * checksum, which is 12 bytes into the packet.
278 * The IPv6 code below accesses through the IPv6 hop limit
279 * which is 8 bytes into the packet.
280 *
281 * For all supported cases there should always be at least 12
282 * bytes of packet data present. The IPv4 header is 20 bytes
283 * without options and the IPv6 header is always 40 bytes
284 * long.
285 */
286 if (!pskb_may_pull(skb, 12))
287 return false;
288
289 payload_type = rt->rt_payload_type;
290 if (payload_type == MPT_UNSPEC)
291 payload_type = ip_hdr(skb)->version;
292
293 switch (payload_type) {
294 case MPT_IPV4: {
295 struct iphdr *hdr4 = ip_hdr(skb);
296 u8 new_ttl;
297 skb->protocol = htons(ETH_P_IP);
298
299 /* If propagating TTL, take the decremented TTL from
300 * the incoming MPLS header, otherwise decrement the
301 * TTL, but only if not 0 to avoid underflow.
302 */
303 if (rt->rt_ttl_propagate == MPLS_TTL_PROP_ENABLED ||
304 (rt->rt_ttl_propagate == MPLS_TTL_PROP_DEFAULT &&
305 net->mpls.ip_ttl_propagate))
306 new_ttl = dec.ttl;
307 else
308 new_ttl = hdr4->ttl ? hdr4->ttl - 1 : 0;
309
310 csum_replace2(&hdr4->check,
311 htons(hdr4->ttl << 8),
312 htons(new_ttl << 8));
313 hdr4->ttl = new_ttl;
314 success = true;
315 break;
316 }
317 case MPT_IPV6: {
318 struct ipv6hdr *hdr6 = ipv6_hdr(skb);
319 skb->protocol = htons(ETH_P_IPV6);
320
321 /* If propagating TTL, take the decremented TTL from
322 * the incoming MPLS header, otherwise decrement the
323 * hop limit, but only if not 0 to avoid underflow.
324 */
325 if (rt->rt_ttl_propagate == MPLS_TTL_PROP_ENABLED ||
326 (rt->rt_ttl_propagate == MPLS_TTL_PROP_DEFAULT &&
327 net->mpls.ip_ttl_propagate))
328 hdr6->hop_limit = dec.ttl;
329 else if (hdr6->hop_limit)
330 hdr6->hop_limit = hdr6->hop_limit - 1;
331 success = true;
332 break;
333 }
334 case MPT_UNSPEC:
335 /* Should have decided which protocol it is by now */
336 break;
337 }
338
339 return success;
340 }
341
342 static int mpls_forward(struct sk_buff *skb, struct net_device *dev,
343 struct packet_type *pt, struct net_device *orig_dev)
344 {
345 struct net *net = dev_net(dev);
346 struct mpls_shim_hdr *hdr;
347 struct mpls_route *rt;
348 struct mpls_nh *nh;
349 struct mpls_entry_decoded dec;
350 struct net_device *out_dev;
351 struct mpls_dev *out_mdev;
352 struct mpls_dev *mdev;
353 unsigned int hh_len;
354 unsigned int new_header_size;
355 unsigned int mtu;
356 int err;
357
358 /* Careful this entire function runs inside of an rcu critical section */
359
360 mdev = mpls_dev_get(dev);
361 if (!mdev)
362 goto drop;
363
364 MPLS_INC_STATS_LEN(mdev, skb->len, rx_packets,
365 rx_bytes);
366
367 if (!mdev->input_enabled) {
368 MPLS_INC_STATS(mdev, rx_dropped);
369 goto drop;
370 }
371
372 if (skb->pkt_type != PACKET_HOST)
373 goto err;
374
375 if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
376 goto err;
377
378 if (!pskb_may_pull(skb, sizeof(*hdr)))
379 goto err;
380
381 /* Read and decode the label */
382 hdr = mpls_hdr(skb);
383 dec = mpls_entry_decode(hdr);
384
385 rt = mpls_route_input_rcu(net, dec.label);
386 if (!rt) {
387 MPLS_INC_STATS(mdev, rx_noroute);
388 goto drop;
389 }
390
391 nh = mpls_select_multipath(rt, skb);
392 if (!nh)
393 goto err;
394
395 /* Pop the label */
396 skb_pull(skb, sizeof(*hdr));
397 skb_reset_network_header(skb);
398
399 skb_orphan(skb);
400
401 if (skb_warn_if_lro(skb))
402 goto err;
403
404 skb_forward_csum(skb);
405
406 /* Verify ttl is valid */
407 if (dec.ttl <= 1)
408 goto err;
409 dec.ttl -= 1;
410
411 /* Find the output device */
412 out_dev = rcu_dereference(nh->nh_dev);
413 if (!mpls_output_possible(out_dev))
414 goto tx_err;
415
416 /* Verify the destination can hold the packet */
417 new_header_size = mpls_nh_header_size(nh);
418 mtu = mpls_dev_mtu(out_dev);
419 if (mpls_pkt_too_big(skb, mtu - new_header_size))
420 goto tx_err;
421
422 hh_len = LL_RESERVED_SPACE(out_dev);
423 if (!out_dev->header_ops)
424 hh_len = 0;
425
426 /* Ensure there is enough space for the headers in the skb */
427 if (skb_cow(skb, hh_len + new_header_size))
428 goto tx_err;
429
430 skb->dev = out_dev;
431 skb->protocol = htons(ETH_P_MPLS_UC);
432
433 if (unlikely(!new_header_size && dec.bos)) {
434 /* Penultimate hop popping */
435 if (!mpls_egress(dev_net(out_dev), rt, skb, dec))
436 goto err;
437 } else {
438 bool bos;
439 int i;
440 skb_push(skb, new_header_size);
441 skb_reset_network_header(skb);
442 /* Push the new labels */
443 hdr = mpls_hdr(skb);
444 bos = dec.bos;
445 for (i = nh->nh_labels - 1; i >= 0; i--) {
446 hdr[i] = mpls_entry_encode(nh->nh_label[i],
447 dec.ttl, 0, bos);
448 bos = false;
449 }
450 }
451
452 mpls_stats_inc_outucastpkts(out_dev, skb);
453
454 /* If via wasn't specified then send out using device address */
455 if (nh->nh_via_table == MPLS_NEIGH_TABLE_UNSPEC)
456 err = neigh_xmit(NEIGH_LINK_TABLE, out_dev,
457 out_dev->dev_addr, skb);
458 else
459 err = neigh_xmit(nh->nh_via_table, out_dev,
460 mpls_nh_via(rt, nh), skb);
461 if (err)
462 net_dbg_ratelimited("%s: packet transmission failed: %d\n",
463 __func__, err);
464 return 0;
465
466 tx_err:
467 out_mdev = out_dev ? mpls_dev_get(out_dev) : NULL;
468 if (out_mdev)
469 MPLS_INC_STATS(out_mdev, tx_errors);
470 goto drop;
471 err:
472 MPLS_INC_STATS(mdev, rx_errors);
473 drop:
474 kfree_skb(skb);
475 return NET_RX_DROP;
476 }
477
478 static struct packet_type mpls_packet_type __read_mostly = {
479 .type = cpu_to_be16(ETH_P_MPLS_UC),
480 .func = mpls_forward,
481 };
482
483 static const struct nla_policy rtm_mpls_policy[RTA_MAX+1] = {
484 [RTA_DST] = { .type = NLA_U32 },
485 [RTA_OIF] = { .type = NLA_U32 },
486 [RTA_TTL_PROPAGATE] = { .type = NLA_U8 },
487 };
488
489 struct mpls_route_config {
490 u32 rc_protocol;
491 u32 rc_ifindex;
492 u8 rc_via_table;
493 u8 rc_via_alen;
494 u8 rc_via[MAX_VIA_ALEN];
495 u32 rc_label;
496 u8 rc_ttl_propagate;
497 u8 rc_output_labels;
498 u32 rc_output_label[MAX_NEW_LABELS];
499 u32 rc_nlflags;
500 enum mpls_payload_type rc_payload_type;
501 struct nl_info rc_nlinfo;
502 struct rtnexthop *rc_mp;
503 int rc_mp_len;
504 };
505
506 /* all nexthops within a route have the same size based on max
507 * number of labels and max via length for a hop
508 */
509 static struct mpls_route *mpls_rt_alloc(u8 num_nh, u8 max_alen, u8 max_labels)
510 {
511 u8 nh_size = MPLS_NH_SIZE(max_labels, max_alen);
512 struct mpls_route *rt;
513 size_t size;
514
515 size = sizeof(*rt) + num_nh * nh_size;
516 if (size > MAX_MPLS_ROUTE_MEM)
517 return ERR_PTR(-EINVAL);
518
519 rt = kzalloc(size, GFP_KERNEL);
520 if (!rt)
521 return ERR_PTR(-ENOMEM);
522
523 rt->rt_nhn = num_nh;
524 rt->rt_nhn_alive = num_nh;
525 rt->rt_nh_size = nh_size;
526 rt->rt_via_offset = MPLS_NH_VIA_OFF(max_labels);
527
528 return rt;
529 }
530
531 static void mpls_rt_free(struct mpls_route *rt)
532 {
533 if (rt)
534 kfree_rcu(rt, rt_rcu);
535 }
536
537 static void mpls_notify_route(struct net *net, unsigned index,
538 struct mpls_route *old, struct mpls_route *new,
539 const struct nl_info *info)
540 {
541 struct nlmsghdr *nlh = info ? info->nlh : NULL;
542 unsigned portid = info ? info->portid : 0;
543 int event = new ? RTM_NEWROUTE : RTM_DELROUTE;
544 struct mpls_route *rt = new ? new : old;
545 unsigned nlm_flags = (old && new) ? NLM_F_REPLACE : 0;
546 /* Ignore reserved labels for now */
547 if (rt && (index >= MPLS_LABEL_FIRST_UNRESERVED))
548 rtmsg_lfib(event, index, rt, nlh, net, portid, nlm_flags);
549 }
550
551 static void mpls_route_update(struct net *net, unsigned index,
552 struct mpls_route *new,
553 const struct nl_info *info)
554 {
555 struct mpls_route __rcu **platform_label;
556 struct mpls_route *rt;
557
558 ASSERT_RTNL();
559
560 platform_label = rtnl_dereference(net->mpls.platform_label);
561 rt = rtnl_dereference(platform_label[index]);
562 rcu_assign_pointer(platform_label[index], new);
563
564 mpls_notify_route(net, index, rt, new, info);
565
566 /* If we removed a route free it now */
567 mpls_rt_free(rt);
568 }
569
570 static unsigned find_free_label(struct net *net)
571 {
572 struct mpls_route __rcu **platform_label;
573 size_t platform_labels;
574 unsigned index;
575
576 platform_label = rtnl_dereference(net->mpls.platform_label);
577 platform_labels = net->mpls.platform_labels;
578 for (index = MPLS_LABEL_FIRST_UNRESERVED; index < platform_labels;
579 index++) {
580 if (!rtnl_dereference(platform_label[index]))
581 return index;
582 }
583 return LABEL_NOT_SPECIFIED;
584 }
585
586 #if IS_ENABLED(CONFIG_INET)
587 static struct net_device *inet_fib_lookup_dev(struct net *net,
588 const void *addr)
589 {
590 struct net_device *dev;
591 struct rtable *rt;
592 struct in_addr daddr;
593
594 memcpy(&daddr, addr, sizeof(struct in_addr));
595 rt = ip_route_output(net, daddr.s_addr, 0, 0, 0);
596 if (IS_ERR(rt))
597 return ERR_CAST(rt);
598
599 dev = rt->dst.dev;
600 dev_hold(dev);
601
602 ip_rt_put(rt);
603
604 return dev;
605 }
606 #else
607 static struct net_device *inet_fib_lookup_dev(struct net *net,
608 const void *addr)
609 {
610 return ERR_PTR(-EAFNOSUPPORT);
611 }
612 #endif
613
614 #if IS_ENABLED(CONFIG_IPV6)
615 static struct net_device *inet6_fib_lookup_dev(struct net *net,
616 const void *addr)
617 {
618 struct net_device *dev;
619 struct dst_entry *dst;
620 struct flowi6 fl6;
621 int err;
622
623 if (!ipv6_stub)
624 return ERR_PTR(-EAFNOSUPPORT);
625
626 memset(&fl6, 0, sizeof(fl6));
627 memcpy(&fl6.daddr, addr, sizeof(struct in6_addr));
628 err = ipv6_stub->ipv6_dst_lookup(net, NULL, &dst, &fl6);
629 if (err)
630 return ERR_PTR(err);
631
632 dev = dst->dev;
633 dev_hold(dev);
634 dst_release(dst);
635
636 return dev;
637 }
638 #else
639 static struct net_device *inet6_fib_lookup_dev(struct net *net,
640 const void *addr)
641 {
642 return ERR_PTR(-EAFNOSUPPORT);
643 }
644 #endif
645
646 static struct net_device *find_outdev(struct net *net,
647 struct mpls_route *rt,
648 struct mpls_nh *nh, int oif)
649 {
650 struct net_device *dev = NULL;
651
652 if (!oif) {
653 switch (nh->nh_via_table) {
654 case NEIGH_ARP_TABLE:
655 dev = inet_fib_lookup_dev(net, mpls_nh_via(rt, nh));
656 break;
657 case NEIGH_ND_TABLE:
658 dev = inet6_fib_lookup_dev(net, mpls_nh_via(rt, nh));
659 break;
660 case NEIGH_LINK_TABLE:
661 break;
662 }
663 } else {
664 dev = dev_get_by_index(net, oif);
665 }
666
667 if (!dev)
668 return ERR_PTR(-ENODEV);
669
670 if (IS_ERR(dev))
671 return dev;
672
673 /* The caller is holding rtnl anyways, so release the dev reference */
674 dev_put(dev);
675
676 return dev;
677 }
678
679 static int mpls_nh_assign_dev(struct net *net, struct mpls_route *rt,
680 struct mpls_nh *nh, int oif)
681 {
682 struct net_device *dev = NULL;
683 int err = -ENODEV;
684
685 dev = find_outdev(net, rt, nh, oif);
686 if (IS_ERR(dev)) {
687 err = PTR_ERR(dev);
688 dev = NULL;
689 goto errout;
690 }
691
692 /* Ensure this is a supported device */
693 err = -EINVAL;
694 if (!mpls_dev_get(dev))
695 goto errout;
696
697 if ((nh->nh_via_table == NEIGH_LINK_TABLE) &&
698 (dev->addr_len != nh->nh_via_alen))
699 goto errout;
700
701 RCU_INIT_POINTER(nh->nh_dev, dev);
702
703 if (!(dev->flags & IFF_UP)) {
704 nh->nh_flags |= RTNH_F_DEAD;
705 } else {
706 unsigned int flags;
707
708 flags = dev_get_flags(dev);
709 if (!(flags & (IFF_RUNNING | IFF_LOWER_UP)))
710 nh->nh_flags |= RTNH_F_LINKDOWN;
711 }
712
713 return 0;
714
715 errout:
716 return err;
717 }
718
719 static int nla_get_via(const struct nlattr *nla, u8 *via_alen, u8 *via_table,
720 u8 via_addr[], struct netlink_ext_ack *extack)
721 {
722 struct rtvia *via = nla_data(nla);
723 int err = -EINVAL;
724 int alen;
725
726 if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) {
727 NL_SET_ERR_MSG_ATTR(extack, nla,
728 "Invalid attribute length for RTA_VIA");
729 goto errout;
730 }
731 alen = nla_len(nla) -
732 offsetof(struct rtvia, rtvia_addr);
733 if (alen > MAX_VIA_ALEN) {
734 NL_SET_ERR_MSG_ATTR(extack, nla,
735 "Invalid address length for RTA_VIA");
736 goto errout;
737 }
738
739 /* Validate the address family */
740 switch (via->rtvia_family) {
741 case AF_PACKET:
742 *via_table = NEIGH_LINK_TABLE;
743 break;
744 case AF_INET:
745 *via_table = NEIGH_ARP_TABLE;
746 if (alen != 4)
747 goto errout;
748 break;
749 case AF_INET6:
750 *via_table = NEIGH_ND_TABLE;
751 if (alen != 16)
752 goto errout;
753 break;
754 default:
755 /* Unsupported address family */
756 goto errout;
757 }
758
759 memcpy(via_addr, via->rtvia_addr, alen);
760 *via_alen = alen;
761 err = 0;
762
763 errout:
764 return err;
765 }
766
767 static int mpls_nh_build_from_cfg(struct mpls_route_config *cfg,
768 struct mpls_route *rt)
769 {
770 struct net *net = cfg->rc_nlinfo.nl_net;
771 struct mpls_nh *nh = rt->rt_nh;
772 int err;
773 int i;
774
775 if (!nh)
776 return -ENOMEM;
777
778 nh->nh_labels = cfg->rc_output_labels;
779 for (i = 0; i < nh->nh_labels; i++)
780 nh->nh_label[i] = cfg->rc_output_label[i];
781
782 nh->nh_via_table = cfg->rc_via_table;
783 memcpy(__mpls_nh_via(rt, nh), cfg->rc_via, cfg->rc_via_alen);
784 nh->nh_via_alen = cfg->rc_via_alen;
785
786 err = mpls_nh_assign_dev(net, rt, nh, cfg->rc_ifindex);
787 if (err)
788 goto errout;
789
790 if (nh->nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN))
791 rt->rt_nhn_alive--;
792
793 return 0;
794
795 errout:
796 return err;
797 }
798
799 static int mpls_nh_build(struct net *net, struct mpls_route *rt,
800 struct mpls_nh *nh, int oif, struct nlattr *via,
801 struct nlattr *newdst, u8 max_labels,
802 struct netlink_ext_ack *extack)
803 {
804 int err = -ENOMEM;
805
806 if (!nh)
807 goto errout;
808
809 if (newdst) {
810 err = nla_get_labels(newdst, max_labels, &nh->nh_labels,
811 nh->nh_label, extack);
812 if (err)
813 goto errout;
814 }
815
816 if (via) {
817 err = nla_get_via(via, &nh->nh_via_alen, &nh->nh_via_table,
818 __mpls_nh_via(rt, nh), extack);
819 if (err)
820 goto errout;
821 } else {
822 nh->nh_via_table = MPLS_NEIGH_TABLE_UNSPEC;
823 }
824
825 err = mpls_nh_assign_dev(net, rt, nh, oif);
826 if (err)
827 goto errout;
828
829 return 0;
830
831 errout:
832 return err;
833 }
834
835 static u8 mpls_count_nexthops(struct rtnexthop *rtnh, int len,
836 u8 cfg_via_alen, u8 *max_via_alen,
837 u8 *max_labels)
838 {
839 int remaining = len;
840 u8 nhs = 0;
841
842 *max_via_alen = 0;
843 *max_labels = 0;
844
845 while (rtnh_ok(rtnh, remaining)) {
846 struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
847 int attrlen;
848 u8 n_labels = 0;
849
850 attrlen = rtnh_attrlen(rtnh);
851 nla = nla_find(attrs, attrlen, RTA_VIA);
852 if (nla && nla_len(nla) >=
853 offsetof(struct rtvia, rtvia_addr)) {
854 int via_alen = nla_len(nla) -
855 offsetof(struct rtvia, rtvia_addr);
856
857 if (via_alen <= MAX_VIA_ALEN)
858 *max_via_alen = max_t(u16, *max_via_alen,
859 via_alen);
860 }
861
862 nla = nla_find(attrs, attrlen, RTA_NEWDST);
863 if (nla &&
864 nla_get_labels(nla, MAX_NEW_LABELS, &n_labels,
865 NULL, NULL) != 0)
866 return 0;
867
868 *max_labels = max_t(u8, *max_labels, n_labels);
869
870 /* number of nexthops is tracked by a u8.
871 * Check for overflow.
872 */
873 if (nhs == 255)
874 return 0;
875 nhs++;
876
877 rtnh = rtnh_next(rtnh, &remaining);
878 }
879
880 /* leftover implies invalid nexthop configuration, discard it */
881 return remaining > 0 ? 0 : nhs;
882 }
883
884 static int mpls_nh_build_multi(struct mpls_route_config *cfg,
885 struct mpls_route *rt, u8 max_labels,
886 struct netlink_ext_ack *extack)
887 {
888 struct rtnexthop *rtnh = cfg->rc_mp;
889 struct nlattr *nla_via, *nla_newdst;
890 int remaining = cfg->rc_mp_len;
891 int err = 0;
892 u8 nhs = 0;
893
894 change_nexthops(rt) {
895 int attrlen;
896
897 nla_via = NULL;
898 nla_newdst = NULL;
899
900 err = -EINVAL;
901 if (!rtnh_ok(rtnh, remaining))
902 goto errout;
903
904 /* neither weighted multipath nor any flags
905 * are supported
906 */
907 if (rtnh->rtnh_hops || rtnh->rtnh_flags)
908 goto errout;
909
910 attrlen = rtnh_attrlen(rtnh);
911 if (attrlen > 0) {
912 struct nlattr *attrs = rtnh_attrs(rtnh);
913
914 nla_via = nla_find(attrs, attrlen, RTA_VIA);
915 nla_newdst = nla_find(attrs, attrlen, RTA_NEWDST);
916 }
917
918 err = mpls_nh_build(cfg->rc_nlinfo.nl_net, rt, nh,
919 rtnh->rtnh_ifindex, nla_via, nla_newdst,
920 max_labels, extack);
921 if (err)
922 goto errout;
923
924 if (nh->nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN))
925 rt->rt_nhn_alive--;
926
927 rtnh = rtnh_next(rtnh, &remaining);
928 nhs++;
929 } endfor_nexthops(rt);
930
931 rt->rt_nhn = nhs;
932
933 return 0;
934
935 errout:
936 return err;
937 }
938
939 static bool mpls_label_ok(struct net *net, unsigned int *index,
940 struct netlink_ext_ack *extack)
941 {
942 bool is_ok = true;
943
944 /* Reserved labels may not be set */
945 if (*index < MPLS_LABEL_FIRST_UNRESERVED) {
946 NL_SET_ERR_MSG(extack,
947 "Invalid label - must be MPLS_LABEL_FIRST_UNRESERVED or higher");
948 is_ok = false;
949 }
950
951 /* The full 20 bit range may not be supported. */
952 if (is_ok && *index >= net->mpls.platform_labels) {
953 NL_SET_ERR_MSG(extack,
954 "Label >= configured maximum in platform_labels");
955 is_ok = false;
956 }
957
958 *index = array_index_nospec(*index, net->mpls.platform_labels);
959 return is_ok;
960 }
961
962 static int mpls_route_add(struct mpls_route_config *cfg,
963 struct netlink_ext_ack *extack)
964 {
965 struct mpls_route __rcu **platform_label;
966 struct net *net = cfg->rc_nlinfo.nl_net;
967 struct mpls_route *rt, *old;
968 int err = -EINVAL;
969 u8 max_via_alen;
970 unsigned index;
971 u8 max_labels;
972 u8 nhs;
973
974 index = cfg->rc_label;
975
976 /* If a label was not specified during insert pick one */
977 if ((index == LABEL_NOT_SPECIFIED) &&
978 (cfg->rc_nlflags & NLM_F_CREATE)) {
979 index = find_free_label(net);
980 }
981
982 if (!mpls_label_ok(net, &index, extack))
983 goto errout;
984
985 /* Append makes no sense with mpls */
986 err = -EOPNOTSUPP;
987 if (cfg->rc_nlflags & NLM_F_APPEND) {
988 NL_SET_ERR_MSG(extack, "MPLS does not support route append");
989 goto errout;
990 }
991
992 err = -EEXIST;
993 platform_label = rtnl_dereference(net->mpls.platform_label);
994 old = rtnl_dereference(platform_label[index]);
995 if ((cfg->rc_nlflags & NLM_F_EXCL) && old)
996 goto errout;
997
998 err = -EEXIST;
999 if (!(cfg->rc_nlflags & NLM_F_REPLACE) && old)
1000 goto errout;
1001
1002 err = -ENOENT;
1003 if (!(cfg->rc_nlflags & NLM_F_CREATE) && !old)
1004 goto errout;
1005
1006 err = -EINVAL;
1007 if (cfg->rc_mp) {
1008 nhs = mpls_count_nexthops(cfg->rc_mp, cfg->rc_mp_len,
1009 cfg->rc_via_alen, &max_via_alen,
1010 &max_labels);
1011 } else {
1012 max_via_alen = cfg->rc_via_alen;
1013 max_labels = cfg->rc_output_labels;
1014 nhs = 1;
1015 }
1016
1017 if (nhs == 0) {
1018 NL_SET_ERR_MSG(extack, "Route does not contain a nexthop");
1019 goto errout;
1020 }
1021
1022 err = -ENOMEM;
1023 rt = mpls_rt_alloc(nhs, max_via_alen, max_labels);
1024 if (IS_ERR(rt)) {
1025 err = PTR_ERR(rt);
1026 goto errout;
1027 }
1028
1029 rt->rt_protocol = cfg->rc_protocol;
1030 rt->rt_payload_type = cfg->rc_payload_type;
1031 rt->rt_ttl_propagate = cfg->rc_ttl_propagate;
1032
1033 if (cfg->rc_mp)
1034 err = mpls_nh_build_multi(cfg, rt, max_labels, extack);
1035 else
1036 err = mpls_nh_build_from_cfg(cfg, rt);
1037 if (err)
1038 goto freert;
1039
1040 mpls_route_update(net, index, rt, &cfg->rc_nlinfo);
1041
1042 return 0;
1043
1044 freert:
1045 mpls_rt_free(rt);
1046 errout:
1047 return err;
1048 }
1049
1050 static int mpls_route_del(struct mpls_route_config *cfg,
1051 struct netlink_ext_ack *extack)
1052 {
1053 struct net *net = cfg->rc_nlinfo.nl_net;
1054 unsigned index;
1055 int err = -EINVAL;
1056
1057 index = cfg->rc_label;
1058
1059 if (!mpls_label_ok(net, &index, extack))
1060 goto errout;
1061
1062 mpls_route_update(net, index, NULL, &cfg->rc_nlinfo);
1063
1064 err = 0;
1065 errout:
1066 return err;
1067 }
1068
1069 static void mpls_get_stats(struct mpls_dev *mdev,
1070 struct mpls_link_stats *stats)
1071 {
1072 struct mpls_pcpu_stats *p;
1073 int i;
1074
1075 memset(stats, 0, sizeof(*stats));
1076
1077 for_each_possible_cpu(i) {
1078 struct mpls_link_stats local;
1079 unsigned int start;
1080
1081 p = per_cpu_ptr(mdev->stats, i);
1082 do {
1083 start = u64_stats_fetch_begin(&p->syncp);
1084 local = p->stats;
1085 } while (u64_stats_fetch_retry(&p->syncp, start));
1086
1087 stats->rx_packets += local.rx_packets;
1088 stats->rx_bytes += local.rx_bytes;
1089 stats->tx_packets += local.tx_packets;
1090 stats->tx_bytes += local.tx_bytes;
1091 stats->rx_errors += local.rx_errors;
1092 stats->tx_errors += local.tx_errors;
1093 stats->rx_dropped += local.rx_dropped;
1094 stats->tx_dropped += local.tx_dropped;
1095 stats->rx_noroute += local.rx_noroute;
1096 }
1097 }
1098
1099 static int mpls_fill_stats_af(struct sk_buff *skb,
1100 const struct net_device *dev)
1101 {
1102 struct mpls_link_stats *stats;
1103 struct mpls_dev *mdev;
1104 struct nlattr *nla;
1105
1106 mdev = mpls_dev_get(dev);
1107 if (!mdev)
1108 return -ENODATA;
1109
1110 nla = nla_reserve_64bit(skb, MPLS_STATS_LINK,
1111 sizeof(struct mpls_link_stats),
1112 MPLS_STATS_UNSPEC);
1113 if (!nla)
1114 return -EMSGSIZE;
1115
1116 stats = nla_data(nla);
1117 mpls_get_stats(mdev, stats);
1118
1119 return 0;
1120 }
1121
1122 static size_t mpls_get_stats_af_size(const struct net_device *dev)
1123 {
1124 struct mpls_dev *mdev;
1125
1126 mdev = mpls_dev_get(dev);
1127 if (!mdev)
1128 return 0;
1129
1130 return nla_total_size_64bit(sizeof(struct mpls_link_stats));
1131 }
1132
1133 static int mpls_netconf_fill_devconf(struct sk_buff *skb, struct mpls_dev *mdev,
1134 u32 portid, u32 seq, int event,
1135 unsigned int flags, int type)
1136 {
1137 struct nlmsghdr *nlh;
1138 struct netconfmsg *ncm;
1139 bool all = false;
1140
1141 nlh = nlmsg_put(skb, portid, seq, event, sizeof(struct netconfmsg),
1142 flags);
1143 if (!nlh)
1144 return -EMSGSIZE;
1145
1146 if (type == NETCONFA_ALL)
1147 all = true;
1148
1149 ncm = nlmsg_data(nlh);
1150 ncm->ncm_family = AF_MPLS;
1151
1152 if (nla_put_s32(skb, NETCONFA_IFINDEX, mdev->dev->ifindex) < 0)
1153 goto nla_put_failure;
1154
1155 if ((all || type == NETCONFA_INPUT) &&
1156 nla_put_s32(skb, NETCONFA_INPUT,
1157 mdev->input_enabled) < 0)
1158 goto nla_put_failure;
1159
1160 nlmsg_end(skb, nlh);
1161 return 0;
1162
1163 nla_put_failure:
1164 nlmsg_cancel(skb, nlh);
1165 return -EMSGSIZE;
1166 }
1167
1168 static int mpls_netconf_msgsize_devconf(int type)
1169 {
1170 int size = NLMSG_ALIGN(sizeof(struct netconfmsg))
1171 + nla_total_size(4); /* NETCONFA_IFINDEX */
1172 bool all = false;
1173
1174 if (type == NETCONFA_ALL)
1175 all = true;
1176
1177 if (all || type == NETCONFA_INPUT)
1178 size += nla_total_size(4);
1179
1180 return size;
1181 }
1182
1183 static void mpls_netconf_notify_devconf(struct net *net, int event,
1184 int type, struct mpls_dev *mdev)
1185 {
1186 struct sk_buff *skb;
1187 int err = -ENOBUFS;
1188
1189 skb = nlmsg_new(mpls_netconf_msgsize_devconf(type), GFP_KERNEL);
1190 if (!skb)
1191 goto errout;
1192
1193 err = mpls_netconf_fill_devconf(skb, mdev, 0, 0, event, 0, type);
1194 if (err < 0) {
1195 /* -EMSGSIZE implies BUG in mpls_netconf_msgsize_devconf() */
1196 WARN_ON(err == -EMSGSIZE);
1197 kfree_skb(skb);
1198 goto errout;
1199 }
1200
1201 rtnl_notify(skb, net, 0, RTNLGRP_MPLS_NETCONF, NULL, GFP_KERNEL);
1202 return;
1203 errout:
1204 if (err < 0)
1205 rtnl_set_sk_err(net, RTNLGRP_MPLS_NETCONF, err);
1206 }
1207
1208 static const struct nla_policy devconf_mpls_policy[NETCONFA_MAX + 1] = {
1209 [NETCONFA_IFINDEX] = { .len = sizeof(int) },
1210 };
1211
1212 static int mpls_netconf_get_devconf(struct sk_buff *in_skb,
1213 struct nlmsghdr *nlh,
1214 struct netlink_ext_ack *extack)
1215 {
1216 struct net *net = sock_net(in_skb->sk);
1217 struct nlattr *tb[NETCONFA_MAX + 1];
1218 struct netconfmsg *ncm;
1219 struct net_device *dev;
1220 struct mpls_dev *mdev;
1221 struct sk_buff *skb;
1222 int ifindex;
1223 int err;
1224
1225 err = nlmsg_parse(nlh, sizeof(*ncm), tb, NETCONFA_MAX,
1226 devconf_mpls_policy, NULL);
1227 if (err < 0)
1228 goto errout;
1229
1230 err = -EINVAL;
1231 if (!tb[NETCONFA_IFINDEX])
1232 goto errout;
1233
1234 ifindex = nla_get_s32(tb[NETCONFA_IFINDEX]);
1235 dev = __dev_get_by_index(net, ifindex);
1236 if (!dev)
1237 goto errout;
1238
1239 mdev = mpls_dev_get(dev);
1240 if (!mdev)
1241 goto errout;
1242
1243 err = -ENOBUFS;
1244 skb = nlmsg_new(mpls_netconf_msgsize_devconf(NETCONFA_ALL), GFP_KERNEL);
1245 if (!skb)
1246 goto errout;
1247
1248 err = mpls_netconf_fill_devconf(skb, mdev,
1249 NETLINK_CB(in_skb).portid,
1250 nlh->nlmsg_seq, RTM_NEWNETCONF, 0,
1251 NETCONFA_ALL);
1252 if (err < 0) {
1253 /* -EMSGSIZE implies BUG in mpls_netconf_msgsize_devconf() */
1254 WARN_ON(err == -EMSGSIZE);
1255 kfree_skb(skb);
1256 goto errout;
1257 }
1258 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
1259 errout:
1260 return err;
1261 }
1262
1263 static int mpls_netconf_dump_devconf(struct sk_buff *skb,
1264 struct netlink_callback *cb)
1265 {
1266 struct net *net = sock_net(skb->sk);
1267 struct hlist_head *head;
1268 struct net_device *dev;
1269 struct mpls_dev *mdev;
1270 int idx, s_idx;
1271 int h, s_h;
1272
1273 s_h = cb->args[0];
1274 s_idx = idx = cb->args[1];
1275
1276 for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {
1277 idx = 0;
1278 head = &net->dev_index_head[h];
1279 rcu_read_lock();
1280 cb->seq = net->dev_base_seq;
1281 hlist_for_each_entry_rcu(dev, head, index_hlist) {
1282 if (idx < s_idx)
1283 goto cont;
1284 mdev = mpls_dev_get(dev);
1285 if (!mdev)
1286 goto cont;
1287 if (mpls_netconf_fill_devconf(skb, mdev,
1288 NETLINK_CB(cb->skb).portid,
1289 cb->nlh->nlmsg_seq,
1290 RTM_NEWNETCONF,
1291 NLM_F_MULTI,
1292 NETCONFA_ALL) < 0) {
1293 rcu_read_unlock();
1294 goto done;
1295 }
1296 nl_dump_check_consistent(cb, nlmsg_hdr(skb));
1297 cont:
1298 idx++;
1299 }
1300 rcu_read_unlock();
1301 }
1302 done:
1303 cb->args[0] = h;
1304 cb->args[1] = idx;
1305
1306 return skb->len;
1307 }
1308
1309 #define MPLS_PERDEV_SYSCTL_OFFSET(field) \
1310 (&((struct mpls_dev *)0)->field)
1311
1312 static int mpls_conf_proc(struct ctl_table *ctl, int write,
1313 void __user *buffer,
1314 size_t *lenp, loff_t *ppos)
1315 {
1316 int oval = *(int *)ctl->data;
1317 int ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
1318
1319 if (write) {
1320 struct mpls_dev *mdev = ctl->extra1;
1321 int i = (int *)ctl->data - (int *)mdev;
1322 struct net *net = ctl->extra2;
1323 int val = *(int *)ctl->data;
1324
1325 if (i == offsetof(struct mpls_dev, input_enabled) &&
1326 val != oval) {
1327 mpls_netconf_notify_devconf(net, RTM_NEWNETCONF,
1328 NETCONFA_INPUT, mdev);
1329 }
1330 }
1331
1332 return ret;
1333 }
1334
1335 static const struct ctl_table mpls_dev_table[] = {
1336 {
1337 .procname = "input",
1338 .maxlen = sizeof(int),
1339 .mode = 0644,
1340 .proc_handler = mpls_conf_proc,
1341 .data = MPLS_PERDEV_SYSCTL_OFFSET(input_enabled),
1342 },
1343 { }
1344 };
1345
1346 static int mpls_dev_sysctl_register(struct net_device *dev,
1347 struct mpls_dev *mdev)
1348 {
1349 char path[sizeof("net/mpls/conf/") + IFNAMSIZ];
1350 struct net *net = dev_net(dev);
1351 struct ctl_table *table;
1352 int i;
1353
1354 table = kmemdup(&mpls_dev_table, sizeof(mpls_dev_table), GFP_KERNEL);
1355 if (!table)
1356 goto out;
1357
1358 /* Table data contains only offsets relative to the base of
1359 * the mdev at this point, so make them absolute.
1360 */
1361 for (i = 0; i < ARRAY_SIZE(mpls_dev_table); i++) {
1362 table[i].data = (char *)mdev + (uintptr_t)table[i].data;
1363 table[i].extra1 = mdev;
1364 table[i].extra2 = net;
1365 }
1366
1367 snprintf(path, sizeof(path), "net/mpls/conf/%s", dev->name);
1368
1369 mdev->sysctl = register_net_sysctl(net, path, table);
1370 if (!mdev->sysctl)
1371 goto free;
1372
1373 mpls_netconf_notify_devconf(net, RTM_NEWNETCONF, NETCONFA_ALL, mdev);
1374 return 0;
1375
1376 free:
1377 kfree(table);
1378 out:
1379 return -ENOBUFS;
1380 }
1381
1382 static void mpls_dev_sysctl_unregister(struct net_device *dev,
1383 struct mpls_dev *mdev)
1384 {
1385 struct net *net = dev_net(dev);
1386 struct ctl_table *table;
1387
1388 table = mdev->sysctl->ctl_table_arg;
1389 unregister_net_sysctl_table(mdev->sysctl);
1390 kfree(table);
1391
1392 mpls_netconf_notify_devconf(net, RTM_DELNETCONF, 0, mdev);
1393 }
1394
1395 static struct mpls_dev *mpls_add_dev(struct net_device *dev)
1396 {
1397 struct mpls_dev *mdev;
1398 int err = -ENOMEM;
1399 int i;
1400
1401 ASSERT_RTNL();
1402
1403 mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
1404 if (!mdev)
1405 return ERR_PTR(err);
1406
1407 mdev->stats = alloc_percpu(struct mpls_pcpu_stats);
1408 if (!mdev->stats)
1409 goto free;
1410
1411 for_each_possible_cpu(i) {
1412 struct mpls_pcpu_stats *mpls_stats;
1413
1414 mpls_stats = per_cpu_ptr(mdev->stats, i);
1415 u64_stats_init(&mpls_stats->syncp);
1416 }
1417
1418 mdev->dev = dev;
1419
1420 err = mpls_dev_sysctl_register(dev, mdev);
1421 if (err)
1422 goto free;
1423
1424 rcu_assign_pointer(dev->mpls_ptr, mdev);
1425
1426 return mdev;
1427
1428 free:
1429 free_percpu(mdev->stats);
1430 kfree(mdev);
1431 return ERR_PTR(err);
1432 }
1433
1434 static void mpls_dev_destroy_rcu(struct rcu_head *head)
1435 {
1436 struct mpls_dev *mdev = container_of(head, struct mpls_dev, rcu);
1437
1438 free_percpu(mdev->stats);
1439 kfree(mdev);
1440 }
1441
1442 static void mpls_ifdown(struct net_device *dev, int event)
1443 {
1444 struct mpls_route __rcu **platform_label;
1445 struct net *net = dev_net(dev);
1446 u8 alive, deleted;
1447 unsigned index;
1448
1449 platform_label = rtnl_dereference(net->mpls.platform_label);
1450 for (index = 0; index < net->mpls.platform_labels; index++) {
1451 struct mpls_route *rt = rtnl_dereference(platform_label[index]);
1452
1453 if (!rt)
1454 continue;
1455
1456 alive = 0;
1457 deleted = 0;
1458 change_nexthops(rt) {
1459 unsigned int nh_flags = nh->nh_flags;
1460
1461 if (rtnl_dereference(nh->nh_dev) != dev)
1462 goto next;
1463
1464 switch (event) {
1465 case NETDEV_DOWN:
1466 case NETDEV_UNREGISTER:
1467 nh_flags |= RTNH_F_DEAD;
1468 /* fall through */
1469 case NETDEV_CHANGE:
1470 nh_flags |= RTNH_F_LINKDOWN;
1471 break;
1472 }
1473 if (event == NETDEV_UNREGISTER)
1474 RCU_INIT_POINTER(nh->nh_dev, NULL);
1475
1476 if (nh->nh_flags != nh_flags)
1477 WRITE_ONCE(nh->nh_flags, nh_flags);
1478 next:
1479 if (!(nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)))
1480 alive++;
1481 if (!rtnl_dereference(nh->nh_dev))
1482 deleted++;
1483 } endfor_nexthops(rt);
1484
1485 WRITE_ONCE(rt->rt_nhn_alive, alive);
1486
1487 /* if there are no more nexthops, delete the route */
1488 if (event == NETDEV_UNREGISTER && deleted == rt->rt_nhn)
1489 mpls_route_update(net, index, NULL, NULL);
1490 }
1491 }
1492
1493 static void mpls_ifup(struct net_device *dev, unsigned int flags)
1494 {
1495 struct mpls_route __rcu **platform_label;
1496 struct net *net = dev_net(dev);
1497 unsigned index;
1498 u8 alive;
1499
1500 platform_label = rtnl_dereference(net->mpls.platform_label);
1501 for (index = 0; index < net->mpls.platform_labels; index++) {
1502 struct mpls_route *rt = rtnl_dereference(platform_label[index]);
1503
1504 if (!rt)
1505 continue;
1506
1507 alive = 0;
1508 change_nexthops(rt) {
1509 unsigned int nh_flags = nh->nh_flags;
1510 struct net_device *nh_dev =
1511 rtnl_dereference(nh->nh_dev);
1512
1513 if (!(nh_flags & flags)) {
1514 alive++;
1515 continue;
1516 }
1517 if (nh_dev != dev)
1518 continue;
1519 alive++;
1520 nh_flags &= ~flags;
1521 WRITE_ONCE(nh->nh_flags, nh_flags);
1522 } endfor_nexthops(rt);
1523
1524 WRITE_ONCE(rt->rt_nhn_alive, alive);
1525 }
1526 }
1527
1528 static int mpls_dev_notify(struct notifier_block *this, unsigned long event,
1529 void *ptr)
1530 {
1531 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1532 struct mpls_dev *mdev;
1533 unsigned int flags;
1534
1535 if (event == NETDEV_REGISTER) {
1536 /* For now just support Ethernet, IPGRE, SIT and IPIP devices */
1537 if (dev->type == ARPHRD_ETHER ||
1538 dev->type == ARPHRD_LOOPBACK ||
1539 dev->type == ARPHRD_IPGRE ||
1540 dev->type == ARPHRD_SIT ||
1541 dev->type == ARPHRD_TUNNEL) {
1542 mdev = mpls_add_dev(dev);
1543 if (IS_ERR(mdev))
1544 return notifier_from_errno(PTR_ERR(mdev));
1545 }
1546 return NOTIFY_OK;
1547 }
1548
1549 mdev = mpls_dev_get(dev);
1550 if (!mdev)
1551 return NOTIFY_OK;
1552
1553 switch (event) {
1554 case NETDEV_DOWN:
1555 mpls_ifdown(dev, event);
1556 break;
1557 case NETDEV_UP:
1558 flags = dev_get_flags(dev);
1559 if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1560 mpls_ifup(dev, RTNH_F_DEAD | RTNH_F_LINKDOWN);
1561 else
1562 mpls_ifup(dev, RTNH_F_DEAD);
1563 break;
1564 case NETDEV_CHANGE:
1565 flags = dev_get_flags(dev);
1566 if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1567 mpls_ifup(dev, RTNH_F_DEAD | RTNH_F_LINKDOWN);
1568 else
1569 mpls_ifdown(dev, event);
1570 break;
1571 case NETDEV_UNREGISTER:
1572 mpls_ifdown(dev, event);
1573 mdev = mpls_dev_get(dev);
1574 if (mdev) {
1575 mpls_dev_sysctl_unregister(dev, mdev);
1576 RCU_INIT_POINTER(dev->mpls_ptr, NULL);
1577 call_rcu(&mdev->rcu, mpls_dev_destroy_rcu);
1578 }
1579 break;
1580 case NETDEV_CHANGENAME:
1581 mdev = mpls_dev_get(dev);
1582 if (mdev) {
1583 int err;
1584
1585 mpls_dev_sysctl_unregister(dev, mdev);
1586 err = mpls_dev_sysctl_register(dev, mdev);
1587 if (err)
1588 return notifier_from_errno(err);
1589 }
1590 break;
1591 }
1592 return NOTIFY_OK;
1593 }
1594
1595 static struct notifier_block mpls_dev_notifier = {
1596 .notifier_call = mpls_dev_notify,
1597 };
1598
1599 static int nla_put_via(struct sk_buff *skb,
1600 u8 table, const void *addr, int alen)
1601 {
1602 static const int table_to_family[NEIGH_NR_TABLES + 1] = {
1603 AF_INET, AF_INET6, AF_DECnet, AF_PACKET,
1604 };
1605 struct nlattr *nla;
1606 struct rtvia *via;
1607 int family = AF_UNSPEC;
1608
1609 nla = nla_reserve(skb, RTA_VIA, alen + 2);
1610 if (!nla)
1611 return -EMSGSIZE;
1612
1613 if (table <= NEIGH_NR_TABLES)
1614 family = table_to_family[table];
1615
1616 via = nla_data(nla);
1617 via->rtvia_family = family;
1618 memcpy(via->rtvia_addr, addr, alen);
1619 return 0;
1620 }
1621
1622 int nla_put_labels(struct sk_buff *skb, int attrtype,
1623 u8 labels, const u32 label[])
1624 {
1625 struct nlattr *nla;
1626 struct mpls_shim_hdr *nla_label;
1627 bool bos;
1628 int i;
1629 nla = nla_reserve(skb, attrtype, labels*4);
1630 if (!nla)
1631 return -EMSGSIZE;
1632
1633 nla_label = nla_data(nla);
1634 bos = true;
1635 for (i = labels - 1; i >= 0; i--) {
1636 nla_label[i] = mpls_entry_encode(label[i], 0, 0, bos);
1637 bos = false;
1638 }
1639
1640 return 0;
1641 }
1642 EXPORT_SYMBOL_GPL(nla_put_labels);
1643
1644 int nla_get_labels(const struct nlattr *nla, u8 max_labels, u8 *labels,
1645 u32 label[], struct netlink_ext_ack *extack)
1646 {
1647 unsigned len = nla_len(nla);
1648 struct mpls_shim_hdr *nla_label;
1649 u8 nla_labels;
1650 bool bos;
1651 int i;
1652
1653 /* len needs to be an even multiple of 4 (the label size). Number
1654 * of labels is a u8 so check for overflow.
1655 */
1656 if (len & 3 || len / 4 > 255) {
1657 NL_SET_ERR_MSG_ATTR(extack, nla,
1658 "Invalid length for labels attribute");
1659 return -EINVAL;
1660 }
1661
1662 /* Limit the number of new labels allowed */
1663 nla_labels = len/4;
1664 if (nla_labels > max_labels) {
1665 NL_SET_ERR_MSG(extack, "Too many labels");
1666 return -EINVAL;
1667 }
1668
1669 /* when label == NULL, caller wants number of labels */
1670 if (!label)
1671 goto out;
1672
1673 nla_label = nla_data(nla);
1674 bos = true;
1675 for (i = nla_labels - 1; i >= 0; i--, bos = false) {
1676 struct mpls_entry_decoded dec;
1677 dec = mpls_entry_decode(nla_label + i);
1678
1679 /* Ensure the bottom of stack flag is properly set
1680 * and ttl and tc are both clear.
1681 */
1682 if (dec.ttl) {
1683 NL_SET_ERR_MSG_ATTR(extack, nla,
1684 "TTL in label must be 0");
1685 return -EINVAL;
1686 }
1687
1688 if (dec.tc) {
1689 NL_SET_ERR_MSG_ATTR(extack, nla,
1690 "Traffic class in label must be 0");
1691 return -EINVAL;
1692 }
1693
1694 if (dec.bos != bos) {
1695 NL_SET_BAD_ATTR(extack, nla);
1696 if (bos) {
1697 NL_SET_ERR_MSG(extack,
1698 "BOS bit must be set in first label");
1699 } else {
1700 NL_SET_ERR_MSG(extack,
1701 "BOS bit can only be set in first label");
1702 }
1703 return -EINVAL;
1704 }
1705
1706 switch (dec.label) {
1707 case MPLS_LABEL_IMPLNULL:
1708 /* RFC3032: This is a label that an LSR may
1709 * assign and distribute, but which never
1710 * actually appears in the encapsulation.
1711 */
1712 NL_SET_ERR_MSG_ATTR(extack, nla,
1713 "Implicit NULL Label (3) can not be used in encapsulation");
1714 return -EINVAL;
1715 }
1716
1717 label[i] = dec.label;
1718 }
1719 out:
1720 *labels = nla_labels;
1721 return 0;
1722 }
1723 EXPORT_SYMBOL_GPL(nla_get_labels);
1724
1725 static int rtm_to_route_config(struct sk_buff *skb,
1726 struct nlmsghdr *nlh,
1727 struct mpls_route_config *cfg,
1728 struct netlink_ext_ack *extack)
1729 {
1730 struct rtmsg *rtm;
1731 struct nlattr *tb[RTA_MAX+1];
1732 int index;
1733 int err;
1734
1735 err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_mpls_policy,
1736 extack);
1737 if (err < 0)
1738 goto errout;
1739
1740 err = -EINVAL;
1741 rtm = nlmsg_data(nlh);
1742
1743 if (rtm->rtm_family != AF_MPLS) {
1744 NL_SET_ERR_MSG(extack, "Invalid address family in rtmsg");
1745 goto errout;
1746 }
1747 if (rtm->rtm_dst_len != 20) {
1748 NL_SET_ERR_MSG(extack, "rtm_dst_len must be 20 for MPLS");
1749 goto errout;
1750 }
1751 if (rtm->rtm_src_len != 0) {
1752 NL_SET_ERR_MSG(extack, "rtm_src_len must be 0 for MPLS");
1753 goto errout;
1754 }
1755 if (rtm->rtm_tos != 0) {
1756 NL_SET_ERR_MSG(extack, "rtm_tos must be 0 for MPLS");
1757 goto errout;
1758 }
1759 if (rtm->rtm_table != RT_TABLE_MAIN) {
1760 NL_SET_ERR_MSG(extack,
1761 "MPLS only supports the main route table");
1762 goto errout;
1763 }
1764 /* Any value is acceptable for rtm_protocol */
1765
1766 /* As mpls uses destination specific addresses
1767 * (or source specific address in the case of multicast)
1768 * all addresses have universal scope.
1769 */
1770 if (rtm->rtm_scope != RT_SCOPE_UNIVERSE) {
1771 NL_SET_ERR_MSG(extack,
1772 "Invalid route scope - MPLS only supports UNIVERSE");
1773 goto errout;
1774 }
1775 if (rtm->rtm_type != RTN_UNICAST) {
1776 NL_SET_ERR_MSG(extack,
1777 "Invalid route type - MPLS only supports UNICAST");
1778 goto errout;
1779 }
1780 if (rtm->rtm_flags != 0) {
1781 NL_SET_ERR_MSG(extack, "rtm_flags must be 0 for MPLS");
1782 goto errout;
1783 }
1784
1785 cfg->rc_label = LABEL_NOT_SPECIFIED;
1786 cfg->rc_protocol = rtm->rtm_protocol;
1787 cfg->rc_via_table = MPLS_NEIGH_TABLE_UNSPEC;
1788 cfg->rc_ttl_propagate = MPLS_TTL_PROP_DEFAULT;
1789 cfg->rc_nlflags = nlh->nlmsg_flags;
1790 cfg->rc_nlinfo.portid = NETLINK_CB(skb).portid;
1791 cfg->rc_nlinfo.nlh = nlh;
1792 cfg->rc_nlinfo.nl_net = sock_net(skb->sk);
1793
1794 for (index = 0; index <= RTA_MAX; index++) {
1795 struct nlattr *nla = tb[index];
1796 if (!nla)
1797 continue;
1798
1799 switch (index) {
1800 case RTA_OIF:
1801 cfg->rc_ifindex = nla_get_u32(nla);
1802 break;
1803 case RTA_NEWDST:
1804 if (nla_get_labels(nla, MAX_NEW_LABELS,
1805 &cfg->rc_output_labels,
1806 cfg->rc_output_label, extack))
1807 goto errout;
1808 break;
1809 case RTA_DST:
1810 {
1811 u8 label_count;
1812 if (nla_get_labels(nla, 1, &label_count,
1813 &cfg->rc_label, extack))
1814 goto errout;
1815
1816 if (!mpls_label_ok(cfg->rc_nlinfo.nl_net,
1817 &cfg->rc_label, extack))
1818 goto errout;
1819 break;
1820 }
1821 case RTA_VIA:
1822 {
1823 if (nla_get_via(nla, &cfg->rc_via_alen,
1824 &cfg->rc_via_table, cfg->rc_via,
1825 extack))
1826 goto errout;
1827 break;
1828 }
1829 case RTA_MULTIPATH:
1830 {
1831 cfg->rc_mp = nla_data(nla);
1832 cfg->rc_mp_len = nla_len(nla);
1833 break;
1834 }
1835 case RTA_TTL_PROPAGATE:
1836 {
1837 u8 ttl_propagate = nla_get_u8(nla);
1838
1839 if (ttl_propagate > 1) {
1840 NL_SET_ERR_MSG_ATTR(extack, nla,
1841 "RTA_TTL_PROPAGATE can only be 0 or 1");
1842 goto errout;
1843 }
1844 cfg->rc_ttl_propagate = ttl_propagate ?
1845 MPLS_TTL_PROP_ENABLED :
1846 MPLS_TTL_PROP_DISABLED;
1847 break;
1848 }
1849 default:
1850 NL_SET_ERR_MSG_ATTR(extack, nla, "Unknown attribute");
1851 /* Unsupported attribute */
1852 goto errout;
1853 }
1854 }
1855
1856 err = 0;
1857 errout:
1858 return err;
1859 }
1860
1861 static int mpls_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
1862 struct netlink_ext_ack *extack)
1863 {
1864 struct mpls_route_config *cfg;
1865 int err;
1866
1867 cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
1868 if (!cfg)
1869 return -ENOMEM;
1870
1871 err = rtm_to_route_config(skb, nlh, cfg, extack);
1872 if (err < 0)
1873 goto out;
1874
1875 err = mpls_route_del(cfg, extack);
1876 out:
1877 kfree(cfg);
1878
1879 return err;
1880 }
1881
1882
1883 static int mpls_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
1884 struct netlink_ext_ack *extack)
1885 {
1886 struct mpls_route_config *cfg;
1887 int err;
1888
1889 cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
1890 if (!cfg)
1891 return -ENOMEM;
1892
1893 err = rtm_to_route_config(skb, nlh, cfg, extack);
1894 if (err < 0)
1895 goto out;
1896
1897 err = mpls_route_add(cfg, extack);
1898 out:
1899 kfree(cfg);
1900
1901 return err;
1902 }
1903
1904 static int mpls_dump_route(struct sk_buff *skb, u32 portid, u32 seq, int event,
1905 u32 label, struct mpls_route *rt, int flags)
1906 {
1907 struct net_device *dev;
1908 struct nlmsghdr *nlh;
1909 struct rtmsg *rtm;
1910
1911 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), flags);
1912 if (nlh == NULL)
1913 return -EMSGSIZE;
1914
1915 rtm = nlmsg_data(nlh);
1916 rtm->rtm_family = AF_MPLS;
1917 rtm->rtm_dst_len = 20;
1918 rtm->rtm_src_len = 0;
1919 rtm->rtm_tos = 0;
1920 rtm->rtm_table = RT_TABLE_MAIN;
1921 rtm->rtm_protocol = rt->rt_protocol;
1922 rtm->rtm_scope = RT_SCOPE_UNIVERSE;
1923 rtm->rtm_type = RTN_UNICAST;
1924 rtm->rtm_flags = 0;
1925
1926 if (nla_put_labels(skb, RTA_DST, 1, &label))
1927 goto nla_put_failure;
1928
1929 if (rt->rt_ttl_propagate != MPLS_TTL_PROP_DEFAULT) {
1930 bool ttl_propagate =
1931 rt->rt_ttl_propagate == MPLS_TTL_PROP_ENABLED;
1932
1933 if (nla_put_u8(skb, RTA_TTL_PROPAGATE,
1934 ttl_propagate))
1935 goto nla_put_failure;
1936 }
1937 if (rt->rt_nhn == 1) {
1938 const struct mpls_nh *nh = rt->rt_nh;
1939
1940 if (nh->nh_labels &&
1941 nla_put_labels(skb, RTA_NEWDST, nh->nh_labels,
1942 nh->nh_label))
1943 goto nla_put_failure;
1944 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC &&
1945 nla_put_via(skb, nh->nh_via_table, mpls_nh_via(rt, nh),
1946 nh->nh_via_alen))
1947 goto nla_put_failure;
1948 dev = rtnl_dereference(nh->nh_dev);
1949 if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex))
1950 goto nla_put_failure;
1951 if (nh->nh_flags & RTNH_F_LINKDOWN)
1952 rtm->rtm_flags |= RTNH_F_LINKDOWN;
1953 if (nh->nh_flags & RTNH_F_DEAD)
1954 rtm->rtm_flags |= RTNH_F_DEAD;
1955 } else {
1956 struct rtnexthop *rtnh;
1957 struct nlattr *mp;
1958 u8 linkdown = 0;
1959 u8 dead = 0;
1960
1961 mp = nla_nest_start(skb, RTA_MULTIPATH);
1962 if (!mp)
1963 goto nla_put_failure;
1964
1965 for_nexthops(rt) {
1966 dev = rtnl_dereference(nh->nh_dev);
1967 if (!dev)
1968 continue;
1969
1970 rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh));
1971 if (!rtnh)
1972 goto nla_put_failure;
1973
1974 rtnh->rtnh_ifindex = dev->ifindex;
1975 if (nh->nh_flags & RTNH_F_LINKDOWN) {
1976 rtnh->rtnh_flags |= RTNH_F_LINKDOWN;
1977 linkdown++;
1978 }
1979 if (nh->nh_flags & RTNH_F_DEAD) {
1980 rtnh->rtnh_flags |= RTNH_F_DEAD;
1981 dead++;
1982 }
1983
1984 if (nh->nh_labels && nla_put_labels(skb, RTA_NEWDST,
1985 nh->nh_labels,
1986 nh->nh_label))
1987 goto nla_put_failure;
1988 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC &&
1989 nla_put_via(skb, nh->nh_via_table,
1990 mpls_nh_via(rt, nh),
1991 nh->nh_via_alen))
1992 goto nla_put_failure;
1993
1994 /* length of rtnetlink header + attributes */
1995 rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *)rtnh;
1996 } endfor_nexthops(rt);
1997
1998 if (linkdown == rt->rt_nhn)
1999 rtm->rtm_flags |= RTNH_F_LINKDOWN;
2000 if (dead == rt->rt_nhn)
2001 rtm->rtm_flags |= RTNH_F_DEAD;
2002
2003 nla_nest_end(skb, mp);
2004 }
2005
2006 nlmsg_end(skb, nlh);
2007 return 0;
2008
2009 nla_put_failure:
2010 nlmsg_cancel(skb, nlh);
2011 return -EMSGSIZE;
2012 }
2013
2014 static int mpls_dump_routes(struct sk_buff *skb, struct netlink_callback *cb)
2015 {
2016 struct net *net = sock_net(skb->sk);
2017 struct mpls_route __rcu **platform_label;
2018 size_t platform_labels;
2019 unsigned int index;
2020
2021 ASSERT_RTNL();
2022
2023 index = cb->args[0];
2024 if (index < MPLS_LABEL_FIRST_UNRESERVED)
2025 index = MPLS_LABEL_FIRST_UNRESERVED;
2026
2027 platform_label = rtnl_dereference(net->mpls.platform_label);
2028 platform_labels = net->mpls.platform_labels;
2029 for (; index < platform_labels; index++) {
2030 struct mpls_route *rt;
2031 rt = rtnl_dereference(platform_label[index]);
2032 if (!rt)
2033 continue;
2034
2035 if (mpls_dump_route(skb, NETLINK_CB(cb->skb).portid,
2036 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
2037 index, rt, NLM_F_MULTI) < 0)
2038 break;
2039 }
2040 cb->args[0] = index;
2041
2042 return skb->len;
2043 }
2044
2045 static inline size_t lfib_nlmsg_size(struct mpls_route *rt)
2046 {
2047 size_t payload =
2048 NLMSG_ALIGN(sizeof(struct rtmsg))
2049 + nla_total_size(4) /* RTA_DST */
2050 + nla_total_size(1); /* RTA_TTL_PROPAGATE */
2051
2052 if (rt->rt_nhn == 1) {
2053 struct mpls_nh *nh = rt->rt_nh;
2054
2055 if (nh->nh_dev)
2056 payload += nla_total_size(4); /* RTA_OIF */
2057 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC) /* RTA_VIA */
2058 payload += nla_total_size(2 + nh->nh_via_alen);
2059 if (nh->nh_labels) /* RTA_NEWDST */
2060 payload += nla_total_size(nh->nh_labels * 4);
2061 } else {
2062 /* each nexthop is packed in an attribute */
2063 size_t nhsize = 0;
2064
2065 for_nexthops(rt) {
2066 if (!rtnl_dereference(nh->nh_dev))
2067 continue;
2068 nhsize += nla_total_size(sizeof(struct rtnexthop));
2069 /* RTA_VIA */
2070 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC)
2071 nhsize += nla_total_size(2 + nh->nh_via_alen);
2072 if (nh->nh_labels)
2073 nhsize += nla_total_size(nh->nh_labels * 4);
2074 } endfor_nexthops(rt);
2075 /* nested attribute */
2076 payload += nla_total_size(nhsize);
2077 }
2078
2079 return payload;
2080 }
2081
2082 static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt,
2083 struct nlmsghdr *nlh, struct net *net, u32 portid,
2084 unsigned int nlm_flags)
2085 {
2086 struct sk_buff *skb;
2087 u32 seq = nlh ? nlh->nlmsg_seq : 0;
2088 int err = -ENOBUFS;
2089
2090 skb = nlmsg_new(lfib_nlmsg_size(rt), GFP_KERNEL);
2091 if (skb == NULL)
2092 goto errout;
2093
2094 err = mpls_dump_route(skb, portid, seq, event, label, rt, nlm_flags);
2095 if (err < 0) {
2096 /* -EMSGSIZE implies BUG in lfib_nlmsg_size */
2097 WARN_ON(err == -EMSGSIZE);
2098 kfree_skb(skb);
2099 goto errout;
2100 }
2101 rtnl_notify(skb, net, portid, RTNLGRP_MPLS_ROUTE, nlh, GFP_KERNEL);
2102
2103 return;
2104 errout:
2105 if (err < 0)
2106 rtnl_set_sk_err(net, RTNLGRP_MPLS_ROUTE, err);
2107 }
2108
2109 static int mpls_getroute(struct sk_buff *in_skb, struct nlmsghdr *in_nlh,
2110 struct netlink_ext_ack *extack)
2111 {
2112 struct net *net = sock_net(in_skb->sk);
2113 u32 portid = NETLINK_CB(in_skb).portid;
2114 u32 in_label = LABEL_NOT_SPECIFIED;
2115 struct nlattr *tb[RTA_MAX + 1];
2116 u32 labels[MAX_NEW_LABELS];
2117 struct mpls_shim_hdr *hdr;
2118 unsigned int hdr_size = 0;
2119 struct net_device *dev;
2120 struct mpls_route *rt;
2121 struct rtmsg *rtm, *r;
2122 struct nlmsghdr *nlh;
2123 struct sk_buff *skb;
2124 struct mpls_nh *nh;
2125 u8 n_labels;
2126 int err;
2127
2128 err = nlmsg_parse(in_nlh, sizeof(*rtm), tb, RTA_MAX,
2129 rtm_mpls_policy, extack);
2130 if (err < 0)
2131 goto errout;
2132
2133 rtm = nlmsg_data(in_nlh);
2134
2135 if (tb[RTA_DST]) {
2136 u8 label_count;
2137
2138 if (nla_get_labels(tb[RTA_DST], 1, &label_count,
2139 &in_label, extack)) {
2140 err = -EINVAL;
2141 goto errout;
2142 }
2143
2144 if (!mpls_label_ok(net, &in_label, extack)) {
2145 err = -EINVAL;
2146 goto errout;
2147 }
2148 }
2149
2150 rt = mpls_route_input_rcu(net, in_label);
2151 if (!rt) {
2152 err = -ENETUNREACH;
2153 goto errout;
2154 }
2155
2156 if (rtm->rtm_flags & RTM_F_FIB_MATCH) {
2157 skb = nlmsg_new(lfib_nlmsg_size(rt), GFP_KERNEL);
2158 if (!skb) {
2159 err = -ENOBUFS;
2160 goto errout;
2161 }
2162
2163 err = mpls_dump_route(skb, portid, in_nlh->nlmsg_seq,
2164 RTM_NEWROUTE, in_label, rt, 0);
2165 if (err < 0) {
2166 /* -EMSGSIZE implies BUG in lfib_nlmsg_size */
2167 WARN_ON(err == -EMSGSIZE);
2168 goto errout_free;
2169 }
2170
2171 return rtnl_unicast(skb, net, portid);
2172 }
2173
2174 if (tb[RTA_NEWDST]) {
2175 if (nla_get_labels(tb[RTA_NEWDST], MAX_NEW_LABELS, &n_labels,
2176 labels, extack) != 0) {
2177 err = -EINVAL;
2178 goto errout;
2179 }
2180
2181 hdr_size = n_labels * sizeof(struct mpls_shim_hdr);
2182 }
2183
2184 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2185 if (!skb) {
2186 err = -ENOBUFS;
2187 goto errout;
2188 }
2189
2190 skb->protocol = htons(ETH_P_MPLS_UC);
2191
2192 if (hdr_size) {
2193 bool bos;
2194 int i;
2195
2196 if (skb_cow(skb, hdr_size)) {
2197 err = -ENOBUFS;
2198 goto errout_free;
2199 }
2200
2201 skb_reserve(skb, hdr_size);
2202 skb_push(skb, hdr_size);
2203 skb_reset_network_header(skb);
2204
2205 /* Push new labels */
2206 hdr = mpls_hdr(skb);
2207 bos = true;
2208 for (i = n_labels - 1; i >= 0; i--) {
2209 hdr[i] = mpls_entry_encode(labels[i],
2210 1, 0, bos);
2211 bos = false;
2212 }
2213 }
2214
2215 nh = mpls_select_multipath(rt, skb);
2216 if (!nh) {
2217 err = -ENETUNREACH;
2218 goto errout_free;
2219 }
2220
2221 if (hdr_size) {
2222 skb_pull(skb, hdr_size);
2223 skb_reset_network_header(skb);
2224 }
2225
2226 nlh = nlmsg_put(skb, portid, in_nlh->nlmsg_seq,
2227 RTM_NEWROUTE, sizeof(*r), 0);
2228 if (!nlh) {
2229 err = -EMSGSIZE;
2230 goto errout_free;
2231 }
2232
2233 r = nlmsg_data(nlh);
2234 r->rtm_family = AF_MPLS;
2235 r->rtm_dst_len = 20;
2236 r->rtm_src_len = 0;
2237 r->rtm_table = RT_TABLE_MAIN;
2238 r->rtm_type = RTN_UNICAST;
2239 r->rtm_scope = RT_SCOPE_UNIVERSE;
2240 r->rtm_protocol = rt->rt_protocol;
2241 r->rtm_flags = 0;
2242
2243 if (nla_put_labels(skb, RTA_DST, 1, &in_label))
2244 goto nla_put_failure;
2245
2246 if (nh->nh_labels &&
2247 nla_put_labels(skb, RTA_NEWDST, nh->nh_labels,
2248 nh->nh_label))
2249 goto nla_put_failure;
2250
2251 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC &&
2252 nla_put_via(skb, nh->nh_via_table, mpls_nh_via(rt, nh),
2253 nh->nh_via_alen))
2254 goto nla_put_failure;
2255 dev = rtnl_dereference(nh->nh_dev);
2256 if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex))
2257 goto nla_put_failure;
2258
2259 nlmsg_end(skb, nlh);
2260
2261 err = rtnl_unicast(skb, net, portid);
2262 errout:
2263 return err;
2264
2265 nla_put_failure:
2266 nlmsg_cancel(skb, nlh);
2267 err = -EMSGSIZE;
2268 errout_free:
2269 kfree_skb(skb);
2270 return err;
2271 }
2272
2273 static int resize_platform_label_table(struct net *net, size_t limit)
2274 {
2275 size_t size = sizeof(struct mpls_route *) * limit;
2276 size_t old_limit;
2277 size_t cp_size;
2278 struct mpls_route __rcu **labels = NULL, **old;
2279 struct mpls_route *rt0 = NULL, *rt2 = NULL;
2280 unsigned index;
2281
2282 if (size) {
2283 labels = kvzalloc(size, GFP_KERNEL);
2284 if (!labels)
2285 goto nolabels;
2286 }
2287
2288 /* In case the predefined labels need to be populated */
2289 if (limit > MPLS_LABEL_IPV4NULL) {
2290 struct net_device *lo = net->loopback_dev;
2291 rt0 = mpls_rt_alloc(1, lo->addr_len, 0);
2292 if (IS_ERR(rt0))
2293 goto nort0;
2294 RCU_INIT_POINTER(rt0->rt_nh->nh_dev, lo);
2295 rt0->rt_protocol = RTPROT_KERNEL;
2296 rt0->rt_payload_type = MPT_IPV4;
2297 rt0->rt_ttl_propagate = MPLS_TTL_PROP_DEFAULT;
2298 rt0->rt_nh->nh_via_table = NEIGH_LINK_TABLE;
2299 rt0->rt_nh->nh_via_alen = lo->addr_len;
2300 memcpy(__mpls_nh_via(rt0, rt0->rt_nh), lo->dev_addr,
2301 lo->addr_len);
2302 }
2303 if (limit > MPLS_LABEL_IPV6NULL) {
2304 struct net_device *lo = net->loopback_dev;
2305 rt2 = mpls_rt_alloc(1, lo->addr_len, 0);
2306 if (IS_ERR(rt2))
2307 goto nort2;
2308 RCU_INIT_POINTER(rt2->rt_nh->nh_dev, lo);
2309 rt2->rt_protocol = RTPROT_KERNEL;
2310 rt2->rt_payload_type = MPT_IPV6;
2311 rt2->rt_ttl_propagate = MPLS_TTL_PROP_DEFAULT;
2312 rt2->rt_nh->nh_via_table = NEIGH_LINK_TABLE;
2313 rt2->rt_nh->nh_via_alen = lo->addr_len;
2314 memcpy(__mpls_nh_via(rt2, rt2->rt_nh), lo->dev_addr,
2315 lo->addr_len);
2316 }
2317
2318 rtnl_lock();
2319 /* Remember the original table */
2320 old = rtnl_dereference(net->mpls.platform_label);
2321 old_limit = net->mpls.platform_labels;
2322
2323 /* Free any labels beyond the new table */
2324 for (index = limit; index < old_limit; index++)
2325 mpls_route_update(net, index, NULL, NULL);
2326
2327 /* Copy over the old labels */
2328 cp_size = size;
2329 if (old_limit < limit)
2330 cp_size = old_limit * sizeof(struct mpls_route *);
2331
2332 memcpy(labels, old, cp_size);
2333
2334 /* If needed set the predefined labels */
2335 if ((old_limit <= MPLS_LABEL_IPV6NULL) &&
2336 (limit > MPLS_LABEL_IPV6NULL)) {
2337 RCU_INIT_POINTER(labels[MPLS_LABEL_IPV6NULL], rt2);
2338 rt2 = NULL;
2339 }
2340
2341 if ((old_limit <= MPLS_LABEL_IPV4NULL) &&
2342 (limit > MPLS_LABEL_IPV4NULL)) {
2343 RCU_INIT_POINTER(labels[MPLS_LABEL_IPV4NULL], rt0);
2344 rt0 = NULL;
2345 }
2346
2347 /* Update the global pointers */
2348 net->mpls.platform_labels = limit;
2349 rcu_assign_pointer(net->mpls.platform_label, labels);
2350
2351 rtnl_unlock();
2352
2353 mpls_rt_free(rt2);
2354 mpls_rt_free(rt0);
2355
2356 if (old) {
2357 synchronize_rcu();
2358 kvfree(old);
2359 }
2360 return 0;
2361
2362 nort2:
2363 mpls_rt_free(rt0);
2364 nort0:
2365 kvfree(labels);
2366 nolabels:
2367 return -ENOMEM;
2368 }
2369
2370 static int mpls_platform_labels(struct ctl_table *table, int write,
2371 void __user *buffer, size_t *lenp, loff_t *ppos)
2372 {
2373 struct net *net = table->data;
2374 int platform_labels = net->mpls.platform_labels;
2375 int ret;
2376 struct ctl_table tmp = {
2377 .procname = table->procname,
2378 .data = &platform_labels,
2379 .maxlen = sizeof(int),
2380 .mode = table->mode,
2381 .extra1 = &zero,
2382 .extra2 = &label_limit,
2383 };
2384
2385 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
2386
2387 if (write && ret == 0)
2388 ret = resize_platform_label_table(net, platform_labels);
2389
2390 return ret;
2391 }
2392
2393 #define MPLS_NS_SYSCTL_OFFSET(field) \
2394 (&((struct net *)0)->field)
2395
2396 static const struct ctl_table mpls_table[] = {
2397 {
2398 .procname = "platform_labels",
2399 .data = NULL,
2400 .maxlen = sizeof(int),
2401 .mode = 0644,
2402 .proc_handler = mpls_platform_labels,
2403 },
2404 {
2405 .procname = "ip_ttl_propagate",
2406 .data = MPLS_NS_SYSCTL_OFFSET(mpls.ip_ttl_propagate),
2407 .maxlen = sizeof(int),
2408 .mode = 0644,
2409 .proc_handler = proc_dointvec_minmax,
2410 .extra1 = &zero,
2411 .extra2 = &one,
2412 },
2413 {
2414 .procname = "default_ttl",
2415 .data = MPLS_NS_SYSCTL_OFFSET(mpls.default_ttl),
2416 .maxlen = sizeof(int),
2417 .mode = 0644,
2418 .proc_handler = proc_dointvec_minmax,
2419 .extra1 = &one,
2420 .extra2 = &ttl_max,
2421 },
2422 { }
2423 };
2424
2425 static int mpls_net_init(struct net *net)
2426 {
2427 struct ctl_table *table;
2428 int i;
2429
2430 net->mpls.platform_labels = 0;
2431 net->mpls.platform_label = NULL;
2432 net->mpls.ip_ttl_propagate = 1;
2433 net->mpls.default_ttl = 255;
2434
2435 table = kmemdup(mpls_table, sizeof(mpls_table), GFP_KERNEL);
2436 if (table == NULL)
2437 return -ENOMEM;
2438
2439 /* Table data contains only offsets relative to the base of
2440 * the mdev at this point, so make them absolute.
2441 */
2442 for (i = 0; i < ARRAY_SIZE(mpls_table) - 1; i++)
2443 table[i].data = (char *)net + (uintptr_t)table[i].data;
2444
2445 net->mpls.ctl = register_net_sysctl(net, "net/mpls", table);
2446 if (net->mpls.ctl == NULL) {
2447 kfree(table);
2448 return -ENOMEM;
2449 }
2450
2451 return 0;
2452 }
2453
2454 static void mpls_net_exit(struct net *net)
2455 {
2456 struct mpls_route __rcu **platform_label;
2457 size_t platform_labels;
2458 struct ctl_table *table;
2459 unsigned int index;
2460
2461 table = net->mpls.ctl->ctl_table_arg;
2462 unregister_net_sysctl_table(net->mpls.ctl);
2463 kfree(table);
2464
2465 /* An rcu grace period has passed since there was a device in
2466 * the network namespace (and thus the last in flight packet)
2467 * left this network namespace. This is because
2468 * unregister_netdevice_many and netdev_run_todo has completed
2469 * for each network device that was in this network namespace.
2470 *
2471 * As such no additional rcu synchronization is necessary when
2472 * freeing the platform_label table.
2473 */
2474 rtnl_lock();
2475 platform_label = rtnl_dereference(net->mpls.platform_label);
2476 platform_labels = net->mpls.platform_labels;
2477 for (index = 0; index < platform_labels; index++) {
2478 struct mpls_route *rt = rtnl_dereference(platform_label[index]);
2479 RCU_INIT_POINTER(platform_label[index], NULL);
2480 mpls_notify_route(net, index, rt, NULL, NULL);
2481 mpls_rt_free(rt);
2482 }
2483 rtnl_unlock();
2484
2485 kvfree(platform_label);
2486 }
2487
2488 static struct pernet_operations mpls_net_ops = {
2489 .init = mpls_net_init,
2490 .exit = mpls_net_exit,
2491 };
2492
2493 static struct rtnl_af_ops mpls_af_ops __read_mostly = {
2494 .family = AF_MPLS,
2495 .fill_stats_af = mpls_fill_stats_af,
2496 .get_stats_af_size = mpls_get_stats_af_size,
2497 };
2498
2499 static int __init mpls_init(void)
2500 {
2501 int err;
2502
2503 BUILD_BUG_ON(sizeof(struct mpls_shim_hdr) != 4);
2504
2505 err = register_pernet_subsys(&mpls_net_ops);
2506 if (err)
2507 goto out;
2508
2509 err = register_netdevice_notifier(&mpls_dev_notifier);
2510 if (err)
2511 goto out_unregister_pernet;
2512
2513 dev_add_pack(&mpls_packet_type);
2514
2515 rtnl_af_register(&mpls_af_ops);
2516
2517 rtnl_register(PF_MPLS, RTM_NEWROUTE, mpls_rtm_newroute, NULL, 0);
2518 rtnl_register(PF_MPLS, RTM_DELROUTE, mpls_rtm_delroute, NULL, 0);
2519 rtnl_register(PF_MPLS, RTM_GETROUTE, mpls_getroute, mpls_dump_routes,
2520 0);
2521 rtnl_register(PF_MPLS, RTM_GETNETCONF, mpls_netconf_get_devconf,
2522 mpls_netconf_dump_devconf, 0);
2523 err = ipgre_tunnel_encap_add_mpls_ops();
2524 if (err)
2525 pr_err("Can't add mpls over gre tunnel ops\n");
2526
2527 err = 0;
2528 out:
2529 return err;
2530
2531 out_unregister_pernet:
2532 unregister_pernet_subsys(&mpls_net_ops);
2533 goto out;
2534 }
2535 module_init(mpls_init);
2536
2537 static void __exit mpls_exit(void)
2538 {
2539 rtnl_unregister_all(PF_MPLS);
2540 rtnl_af_unregister(&mpls_af_ops);
2541 dev_remove_pack(&mpls_packet_type);
2542 unregister_netdevice_notifier(&mpls_dev_notifier);
2543 unregister_pernet_subsys(&mpls_net_ops);
2544 ipgre_tunnel_encap_del_mpls_ops();
2545 }
2546 module_exit(mpls_exit);
2547
2548 MODULE_DESCRIPTION("MultiProtocol Label Switching");
2549 MODULE_LICENSE("GPL v2");
2550 MODULE_ALIAS_NETPROTO(PF_MPLS);
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