1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <linux/types.h>
3 #include <linux/skbuff.h>
4 #include <linux/socket.h>
5 #include <linux/sysctl.h>
6 #include <linux/net.h>
7 #include <linux/module.h>
8 #include <linux/if_arp.h>
9 #include <linux/ipv6.h>
10 #include <linux/mpls.h>
11 #include <linux/netconf.h>
12 #include <linux/nospec.h>
13 #include <linux/vmalloc.h>
14 #include <linux/percpu.h>
15 #include <net/ip.h>
16 #include <net/dst.h>
17 #include <net/sock.h>
18 #include <net/arp.h>
19 #include <net/ip_fib.h>
20 #include <net/netevent.h>
21 #include <net/ip_tunnels.h>
22 #include <net/netns/generic.h>
23 #if IS_ENABLED(CONFIG_IPV6)
24 #include <net/ipv6.h>
25 #endif
26 #include <net/ipv6_stubs.h>
27 #include <net/rtnh.h>
28 #include "internal.h"
29
30 /* max memory we will use for mpls_route */
31 #define MAX_MPLS_ROUTE_MEM 4096
32
33 /* Maximum number of labels to look ahead at when selecting a path of
34 * a multipath route
35 */
36 #define MAX_MP_SELECT_LABELS 4
37
38 #define MPLS_NEIGH_TABLE_UNSPEC (NEIGH_LINK_TABLE + 1)
39
40 static int label_limit = (1 << 20) - 1;
41 static int ttl_max = 255;
42
43 #if IS_ENABLED(CONFIG_NET_IP_TUNNEL)
ipgre_mpls_encap_hlen(struct ip_tunnel_encap * e)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
ipgre_tunnel_encap_add_mpls_ops(void)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
ipgre_tunnel_encap_del_mpls_ops(void)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
ipgre_tunnel_encap_add_mpls_ops(void)63 static int ipgre_tunnel_encap_add_mpls_ops(void)
64 {
65 return 0;
66 }
67
ipgre_tunnel_encap_del_mpls_ops(void)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
mpls_route_input_rcu(struct net * net,unsigned index)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
mpls_output_possible(const struct net_device * dev)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
__mpls_nh_via(struct mpls_route * rt,struct mpls_nh * nh)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
mpls_nh_via(const struct mpls_route * rt,const struct mpls_nh * nh)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
mpls_nh_header_size(const struct mpls_nh * nh)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
mpls_dev_mtu(const struct net_device * dev)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
mpls_pkt_too_big(const struct sk_buff * skb,unsigned int mtu)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_network_len(skb, mtu))
125 return false;
126
127 return true;
128 }
129 EXPORT_SYMBOL_GPL(mpls_pkt_too_big);
130
mpls_stats_inc_outucastpkts(struct net_device * dev,const struct sk_buff * skb)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
mpls_multipath_hash(struct mpls_route * rt,struct sk_buff * skb)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
mpls_get_nexthop(struct mpls_route * rt,u8 index)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 */
mpls_select_multipath(struct mpls_route * rt,struct sk_buff * skb)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
mpls_egress(struct net * net,struct mpls_route * rt,struct sk_buff * skb,struct mpls_entry_decoded dec)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
mpls_forward(struct sk_buff * skb,struct net_device * dev,struct packet_type * pt,struct net_device * orig_dev)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 */
mpls_rt_alloc(u8 num_nh,u8 max_alen,u8 max_labels)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
mpls_rt_free(struct mpls_route * rt)530 static void mpls_rt_free(struct mpls_route *rt)
531 {
532 if (rt)
533 kfree_rcu(rt, rt_rcu);
534 }
535
mpls_notify_route(struct net * net,unsigned index,struct mpls_route * old,struct mpls_route * new,const struct nl_info * info)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
mpls_route_update(struct net * net,unsigned index,struct mpls_route * new,const struct nl_info * info)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
find_free_label(struct net * net)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)
inet_fib_lookup_dev(struct net * net,const void * addr)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
inet_fib_lookup_dev(struct net * net,const void * addr)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)
inet6_fib_lookup_dev(struct net * net,const void * addr)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
621 if (!ipv6_stub)
622 return ERR_PTR(-EAFNOSUPPORT);
623
624 memset(&fl6, 0, sizeof(fl6));
625 memcpy(&fl6.daddr, addr, sizeof(struct in6_addr));
626 dst = ipv6_stub->ipv6_dst_lookup_flow(net, NULL, &fl6, NULL);
627 if (IS_ERR(dst))
628 return ERR_CAST(dst);
629
630 dev = dst->dev;
631 dev_hold(dev);
632 dst_release(dst);
633
634 return dev;
635 }
636 #else
inet6_fib_lookup_dev(struct net * net,const void * addr)637 static struct net_device *inet6_fib_lookup_dev(struct net *net,
638 const void *addr)
639 {
640 return ERR_PTR(-EAFNOSUPPORT);
641 }
642 #endif
643
find_outdev(struct net * net,struct mpls_route * rt,struct mpls_nh * nh,int oif)644 static struct net_device *find_outdev(struct net *net,
645 struct mpls_route *rt,
646 struct mpls_nh *nh, int oif)
647 {
648 struct net_device *dev = NULL;
649
650 if (!oif) {
651 switch (nh->nh_via_table) {
652 case NEIGH_ARP_TABLE:
653 dev = inet_fib_lookup_dev(net, mpls_nh_via(rt, nh));
654 break;
655 case NEIGH_ND_TABLE:
656 dev = inet6_fib_lookup_dev(net, mpls_nh_via(rt, nh));
657 break;
658 case NEIGH_LINK_TABLE:
659 break;
660 }
661 } else {
662 dev = dev_get_by_index(net, oif);
663 }
664
665 if (!dev)
666 return ERR_PTR(-ENODEV);
667
668 if (IS_ERR(dev))
669 return dev;
670
671 /* The caller is holding rtnl anyways, so release the dev reference */
672 dev_put(dev);
673
674 return dev;
675 }
676
mpls_nh_assign_dev(struct net * net,struct mpls_route * rt,struct mpls_nh * nh,int oif)677 static int mpls_nh_assign_dev(struct net *net, struct mpls_route *rt,
678 struct mpls_nh *nh, int oif)
679 {
680 struct net_device *dev = NULL;
681 int err = -ENODEV;
682
683 dev = find_outdev(net, rt, nh, oif);
684 if (IS_ERR(dev)) {
685 err = PTR_ERR(dev);
686 dev = NULL;
687 goto errout;
688 }
689
690 /* Ensure this is a supported device */
691 err = -EINVAL;
692 if (!mpls_dev_get(dev))
693 goto errout;
694
695 if ((nh->nh_via_table == NEIGH_LINK_TABLE) &&
696 (dev->addr_len != nh->nh_via_alen))
697 goto errout;
698
699 RCU_INIT_POINTER(nh->nh_dev, dev);
700
701 if (!(dev->flags & IFF_UP)) {
702 nh->nh_flags |= RTNH_F_DEAD;
703 } else {
704 unsigned int flags;
705
706 flags = dev_get_flags(dev);
707 if (!(flags & (IFF_RUNNING | IFF_LOWER_UP)))
708 nh->nh_flags |= RTNH_F_LINKDOWN;
709 }
710
711 return 0;
712
713 errout:
714 return err;
715 }
716
nla_get_via(const struct nlattr * nla,u8 * via_alen,u8 * via_table,u8 via_addr[],struct netlink_ext_ack * extack)717 static int nla_get_via(const struct nlattr *nla, u8 *via_alen, u8 *via_table,
718 u8 via_addr[], struct netlink_ext_ack *extack)
719 {
720 struct rtvia *via = nla_data(nla);
721 int err = -EINVAL;
722 int alen;
723
724 if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) {
725 NL_SET_ERR_MSG_ATTR(extack, nla,
726 "Invalid attribute length for RTA_VIA");
727 goto errout;
728 }
729 alen = nla_len(nla) -
730 offsetof(struct rtvia, rtvia_addr);
731 if (alen > MAX_VIA_ALEN) {
732 NL_SET_ERR_MSG_ATTR(extack, nla,
733 "Invalid address length for RTA_VIA");
734 goto errout;
735 }
736
737 /* Validate the address family */
738 switch (via->rtvia_family) {
739 case AF_PACKET:
740 *via_table = NEIGH_LINK_TABLE;
741 break;
742 case AF_INET:
743 *via_table = NEIGH_ARP_TABLE;
744 if (alen != 4)
745 goto errout;
746 break;
747 case AF_INET6:
748 *via_table = NEIGH_ND_TABLE;
749 if (alen != 16)
750 goto errout;
751 break;
752 default:
753 /* Unsupported address family */
754 goto errout;
755 }
756
757 memcpy(via_addr, via->rtvia_addr, alen);
758 *via_alen = alen;
759 err = 0;
760
761 errout:
762 return err;
763 }
764
mpls_nh_build_from_cfg(struct mpls_route_config * cfg,struct mpls_route * rt)765 static int mpls_nh_build_from_cfg(struct mpls_route_config *cfg,
766 struct mpls_route *rt)
767 {
768 struct net *net = cfg->rc_nlinfo.nl_net;
769 struct mpls_nh *nh = rt->rt_nh;
770 int err;
771 int i;
772
773 if (!nh)
774 return -ENOMEM;
775
776 nh->nh_labels = cfg->rc_output_labels;
777 for (i = 0; i < nh->nh_labels; i++)
778 nh->nh_label[i] = cfg->rc_output_label[i];
779
780 nh->nh_via_table = cfg->rc_via_table;
781 memcpy(__mpls_nh_via(rt, nh), cfg->rc_via, cfg->rc_via_alen);
782 nh->nh_via_alen = cfg->rc_via_alen;
783
784 err = mpls_nh_assign_dev(net, rt, nh, cfg->rc_ifindex);
785 if (err)
786 goto errout;
787
788 if (nh->nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN))
789 rt->rt_nhn_alive--;
790
791 return 0;
792
793 errout:
794 return err;
795 }
796
mpls_nh_build(struct net * net,struct mpls_route * rt,struct mpls_nh * nh,int oif,struct nlattr * via,struct nlattr * newdst,u8 max_labels,struct netlink_ext_ack * extack)797 static int mpls_nh_build(struct net *net, struct mpls_route *rt,
798 struct mpls_nh *nh, int oif, struct nlattr *via,
799 struct nlattr *newdst, u8 max_labels,
800 struct netlink_ext_ack *extack)
801 {
802 int err = -ENOMEM;
803
804 if (!nh)
805 goto errout;
806
807 if (newdst) {
808 err = nla_get_labels(newdst, max_labels, &nh->nh_labels,
809 nh->nh_label, extack);
810 if (err)
811 goto errout;
812 }
813
814 if (via) {
815 err = nla_get_via(via, &nh->nh_via_alen, &nh->nh_via_table,
816 __mpls_nh_via(rt, nh), extack);
817 if (err)
818 goto errout;
819 } else {
820 nh->nh_via_table = MPLS_NEIGH_TABLE_UNSPEC;
821 }
822
823 err = mpls_nh_assign_dev(net, rt, nh, oif);
824 if (err)
825 goto errout;
826
827 return 0;
828
829 errout:
830 return err;
831 }
832
mpls_count_nexthops(struct rtnexthop * rtnh,int len,u8 cfg_via_alen,u8 * max_via_alen,u8 * max_labels)833 static u8 mpls_count_nexthops(struct rtnexthop *rtnh, int len,
834 u8 cfg_via_alen, u8 *max_via_alen,
835 u8 *max_labels)
836 {
837 int remaining = len;
838 u8 nhs = 0;
839
840 *max_via_alen = 0;
841 *max_labels = 0;
842
843 while (rtnh_ok(rtnh, remaining)) {
844 struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
845 int attrlen;
846 u8 n_labels = 0;
847
848 attrlen = rtnh_attrlen(rtnh);
849 nla = nla_find(attrs, attrlen, RTA_VIA);
850 if (nla && nla_len(nla) >=
851 offsetof(struct rtvia, rtvia_addr)) {
852 int via_alen = nla_len(nla) -
853 offsetof(struct rtvia, rtvia_addr);
854
855 if (via_alen <= MAX_VIA_ALEN)
856 *max_via_alen = max_t(u16, *max_via_alen,
857 via_alen);
858 }
859
860 nla = nla_find(attrs, attrlen, RTA_NEWDST);
861 if (nla &&
862 nla_get_labels(nla, MAX_NEW_LABELS, &n_labels,
863 NULL, NULL) != 0)
864 return 0;
865
866 *max_labels = max_t(u8, *max_labels, n_labels);
867
868 /* number of nexthops is tracked by a u8.
869 * Check for overflow.
870 */
871 if (nhs == 255)
872 return 0;
873 nhs++;
874
875 rtnh = rtnh_next(rtnh, &remaining);
876 }
877
878 /* leftover implies invalid nexthop configuration, discard it */
879 return remaining > 0 ? 0 : nhs;
880 }
881
mpls_nh_build_multi(struct mpls_route_config * cfg,struct mpls_route * rt,u8 max_labels,struct netlink_ext_ack * extack)882 static int mpls_nh_build_multi(struct mpls_route_config *cfg,
883 struct mpls_route *rt, u8 max_labels,
884 struct netlink_ext_ack *extack)
885 {
886 struct rtnexthop *rtnh = cfg->rc_mp;
887 struct nlattr *nla_via, *nla_newdst;
888 int remaining = cfg->rc_mp_len;
889 int err = 0;
890 u8 nhs = 0;
891
892 change_nexthops(rt) {
893 int attrlen;
894
895 nla_via = NULL;
896 nla_newdst = NULL;
897
898 err = -EINVAL;
899 if (!rtnh_ok(rtnh, remaining))
900 goto errout;
901
902 /* neither weighted multipath nor any flags
903 * are supported
904 */
905 if (rtnh->rtnh_hops || rtnh->rtnh_flags)
906 goto errout;
907
908 attrlen = rtnh_attrlen(rtnh);
909 if (attrlen > 0) {
910 struct nlattr *attrs = rtnh_attrs(rtnh);
911
912 nla_via = nla_find(attrs, attrlen, RTA_VIA);
913 nla_newdst = nla_find(attrs, attrlen, RTA_NEWDST);
914 }
915
916 err = mpls_nh_build(cfg->rc_nlinfo.nl_net, rt, nh,
917 rtnh->rtnh_ifindex, nla_via, nla_newdst,
918 max_labels, extack);
919 if (err)
920 goto errout;
921
922 if (nh->nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN))
923 rt->rt_nhn_alive--;
924
925 rtnh = rtnh_next(rtnh, &remaining);
926 nhs++;
927 } endfor_nexthops(rt);
928
929 rt->rt_nhn = nhs;
930
931 return 0;
932
933 errout:
934 return err;
935 }
936
mpls_label_ok(struct net * net,unsigned int * index,struct netlink_ext_ack * extack)937 static bool mpls_label_ok(struct net *net, unsigned int *index,
938 struct netlink_ext_ack *extack)
939 {
940 bool is_ok = true;
941
942 /* Reserved labels may not be set */
943 if (*index < MPLS_LABEL_FIRST_UNRESERVED) {
944 NL_SET_ERR_MSG(extack,
945 "Invalid label - must be MPLS_LABEL_FIRST_UNRESERVED or higher");
946 is_ok = false;
947 }
948
949 /* The full 20 bit range may not be supported. */
950 if (is_ok && *index >= net->mpls.platform_labels) {
951 NL_SET_ERR_MSG(extack,
952 "Label >= configured maximum in platform_labels");
953 is_ok = false;
954 }
955
956 *index = array_index_nospec(*index, net->mpls.platform_labels);
957 return is_ok;
958 }
959
mpls_route_add(struct mpls_route_config * cfg,struct netlink_ext_ack * extack)960 static int mpls_route_add(struct mpls_route_config *cfg,
961 struct netlink_ext_ack *extack)
962 {
963 struct mpls_route __rcu **platform_label;
964 struct net *net = cfg->rc_nlinfo.nl_net;
965 struct mpls_route *rt, *old;
966 int err = -EINVAL;
967 u8 max_via_alen;
968 unsigned index;
969 u8 max_labels;
970 u8 nhs;
971
972 index = cfg->rc_label;
973
974 /* If a label was not specified during insert pick one */
975 if ((index == LABEL_NOT_SPECIFIED) &&
976 (cfg->rc_nlflags & NLM_F_CREATE)) {
977 index = find_free_label(net);
978 }
979
980 if (!mpls_label_ok(net, &index, extack))
981 goto errout;
982
983 /* Append makes no sense with mpls */
984 err = -EOPNOTSUPP;
985 if (cfg->rc_nlflags & NLM_F_APPEND) {
986 NL_SET_ERR_MSG(extack, "MPLS does not support route append");
987 goto errout;
988 }
989
990 err = -EEXIST;
991 platform_label = rtnl_dereference(net->mpls.platform_label);
992 old = rtnl_dereference(platform_label[index]);
993 if ((cfg->rc_nlflags & NLM_F_EXCL) && old)
994 goto errout;
995
996 err = -EEXIST;
997 if (!(cfg->rc_nlflags & NLM_F_REPLACE) && old)
998 goto errout;
999
1000 err = -ENOENT;
1001 if (!(cfg->rc_nlflags & NLM_F_CREATE) && !old)
1002 goto errout;
1003
1004 err = -EINVAL;
1005 if (cfg->rc_mp) {
1006 nhs = mpls_count_nexthops(cfg->rc_mp, cfg->rc_mp_len,
1007 cfg->rc_via_alen, &max_via_alen,
1008 &max_labels);
1009 } else {
1010 max_via_alen = cfg->rc_via_alen;
1011 max_labels = cfg->rc_output_labels;
1012 nhs = 1;
1013 }
1014
1015 if (nhs == 0) {
1016 NL_SET_ERR_MSG(extack, "Route does not contain a nexthop");
1017 goto errout;
1018 }
1019
1020 err = -ENOMEM;
1021 rt = mpls_rt_alloc(nhs, max_via_alen, max_labels);
1022 if (IS_ERR(rt)) {
1023 err = PTR_ERR(rt);
1024 goto errout;
1025 }
1026
1027 rt->rt_protocol = cfg->rc_protocol;
1028 rt->rt_payload_type = cfg->rc_payload_type;
1029 rt->rt_ttl_propagate = cfg->rc_ttl_propagate;
1030
1031 if (cfg->rc_mp)
1032 err = mpls_nh_build_multi(cfg, rt, max_labels, extack);
1033 else
1034 err = mpls_nh_build_from_cfg(cfg, rt);
1035 if (err)
1036 goto freert;
1037
1038 mpls_route_update(net, index, rt, &cfg->rc_nlinfo);
1039
1040 return 0;
1041
1042 freert:
1043 mpls_rt_free(rt);
1044 errout:
1045 return err;
1046 }
1047
mpls_route_del(struct mpls_route_config * cfg,struct netlink_ext_ack * extack)1048 static int mpls_route_del(struct mpls_route_config *cfg,
1049 struct netlink_ext_ack *extack)
1050 {
1051 struct net *net = cfg->rc_nlinfo.nl_net;
1052 unsigned index;
1053 int err = -EINVAL;
1054
1055 index = cfg->rc_label;
1056
1057 if (!mpls_label_ok(net, &index, extack))
1058 goto errout;
1059
1060 mpls_route_update(net, index, NULL, &cfg->rc_nlinfo);
1061
1062 err = 0;
1063 errout:
1064 return err;
1065 }
1066
mpls_get_stats(struct mpls_dev * mdev,struct mpls_link_stats * stats)1067 static void mpls_get_stats(struct mpls_dev *mdev,
1068 struct mpls_link_stats *stats)
1069 {
1070 struct mpls_pcpu_stats *p;
1071 int i;
1072
1073 memset(stats, 0, sizeof(*stats));
1074
1075 for_each_possible_cpu(i) {
1076 struct mpls_link_stats local;
1077 unsigned int start;
1078
1079 p = per_cpu_ptr(mdev->stats, i);
1080 do {
1081 start = u64_stats_fetch_begin(&p->syncp);
1082 local = p->stats;
1083 } while (u64_stats_fetch_retry(&p->syncp, start));
1084
1085 stats->rx_packets += local.rx_packets;
1086 stats->rx_bytes += local.rx_bytes;
1087 stats->tx_packets += local.tx_packets;
1088 stats->tx_bytes += local.tx_bytes;
1089 stats->rx_errors += local.rx_errors;
1090 stats->tx_errors += local.tx_errors;
1091 stats->rx_dropped += local.rx_dropped;
1092 stats->tx_dropped += local.tx_dropped;
1093 stats->rx_noroute += local.rx_noroute;
1094 }
1095 }
1096
mpls_fill_stats_af(struct sk_buff * skb,const struct net_device * dev)1097 static int mpls_fill_stats_af(struct sk_buff *skb,
1098 const struct net_device *dev)
1099 {
1100 struct mpls_link_stats *stats;
1101 struct mpls_dev *mdev;
1102 struct nlattr *nla;
1103
1104 mdev = mpls_dev_get(dev);
1105 if (!mdev)
1106 return -ENODATA;
1107
1108 nla = nla_reserve_64bit(skb, MPLS_STATS_LINK,
1109 sizeof(struct mpls_link_stats),
1110 MPLS_STATS_UNSPEC);
1111 if (!nla)
1112 return -EMSGSIZE;
1113
1114 stats = nla_data(nla);
1115 mpls_get_stats(mdev, stats);
1116
1117 return 0;
1118 }
1119
mpls_get_stats_af_size(const struct net_device * dev)1120 static size_t mpls_get_stats_af_size(const struct net_device *dev)
1121 {
1122 struct mpls_dev *mdev;
1123
1124 mdev = mpls_dev_get(dev);
1125 if (!mdev)
1126 return 0;
1127
1128 return nla_total_size_64bit(sizeof(struct mpls_link_stats));
1129 }
1130
mpls_netconf_fill_devconf(struct sk_buff * skb,struct mpls_dev * mdev,u32 portid,u32 seq,int event,unsigned int flags,int type)1131 static int mpls_netconf_fill_devconf(struct sk_buff *skb, struct mpls_dev *mdev,
1132 u32 portid, u32 seq, int event,
1133 unsigned int flags, int type)
1134 {
1135 struct nlmsghdr *nlh;
1136 struct netconfmsg *ncm;
1137 bool all = false;
1138
1139 nlh = nlmsg_put(skb, portid, seq, event, sizeof(struct netconfmsg),
1140 flags);
1141 if (!nlh)
1142 return -EMSGSIZE;
1143
1144 if (type == NETCONFA_ALL)
1145 all = true;
1146
1147 ncm = nlmsg_data(nlh);
1148 ncm->ncm_family = AF_MPLS;
1149
1150 if (nla_put_s32(skb, NETCONFA_IFINDEX, mdev->dev->ifindex) < 0)
1151 goto nla_put_failure;
1152
1153 if ((all || type == NETCONFA_INPUT) &&
1154 nla_put_s32(skb, NETCONFA_INPUT,
1155 mdev->input_enabled) < 0)
1156 goto nla_put_failure;
1157
1158 nlmsg_end(skb, nlh);
1159 return 0;
1160
1161 nla_put_failure:
1162 nlmsg_cancel(skb, nlh);
1163 return -EMSGSIZE;
1164 }
1165
mpls_netconf_msgsize_devconf(int type)1166 static int mpls_netconf_msgsize_devconf(int type)
1167 {
1168 int size = NLMSG_ALIGN(sizeof(struct netconfmsg))
1169 + nla_total_size(4); /* NETCONFA_IFINDEX */
1170 bool all = false;
1171
1172 if (type == NETCONFA_ALL)
1173 all = true;
1174
1175 if (all || type == NETCONFA_INPUT)
1176 size += nla_total_size(4);
1177
1178 return size;
1179 }
1180
mpls_netconf_notify_devconf(struct net * net,int event,int type,struct mpls_dev * mdev)1181 static void mpls_netconf_notify_devconf(struct net *net, int event,
1182 int type, struct mpls_dev *mdev)
1183 {
1184 struct sk_buff *skb;
1185 int err = -ENOBUFS;
1186
1187 skb = nlmsg_new(mpls_netconf_msgsize_devconf(type), GFP_KERNEL);
1188 if (!skb)
1189 goto errout;
1190
1191 err = mpls_netconf_fill_devconf(skb, mdev, 0, 0, event, 0, type);
1192 if (err < 0) {
1193 /* -EMSGSIZE implies BUG in mpls_netconf_msgsize_devconf() */
1194 WARN_ON(err == -EMSGSIZE);
1195 kfree_skb(skb);
1196 goto errout;
1197 }
1198
1199 rtnl_notify(skb, net, 0, RTNLGRP_MPLS_NETCONF, NULL, GFP_KERNEL);
1200 return;
1201 errout:
1202 if (err < 0)
1203 rtnl_set_sk_err(net, RTNLGRP_MPLS_NETCONF, err);
1204 }
1205
1206 static const struct nla_policy devconf_mpls_policy[NETCONFA_MAX + 1] = {
1207 [NETCONFA_IFINDEX] = { .len = sizeof(int) },
1208 };
1209
mpls_netconf_valid_get_req(struct sk_buff * skb,const struct nlmsghdr * nlh,struct nlattr ** tb,struct netlink_ext_ack * extack)1210 static int mpls_netconf_valid_get_req(struct sk_buff *skb,
1211 const struct nlmsghdr *nlh,
1212 struct nlattr **tb,
1213 struct netlink_ext_ack *extack)
1214 {
1215 int i, err;
1216
1217 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(struct netconfmsg))) {
1218 NL_SET_ERR_MSG_MOD(extack,
1219 "Invalid header for netconf get request");
1220 return -EINVAL;
1221 }
1222
1223 if (!netlink_strict_get_check(skb))
1224 return nlmsg_parse_deprecated(nlh, sizeof(struct netconfmsg),
1225 tb, NETCONFA_MAX,
1226 devconf_mpls_policy, extack);
1227
1228 err = nlmsg_parse_deprecated_strict(nlh, sizeof(struct netconfmsg),
1229 tb, NETCONFA_MAX,
1230 devconf_mpls_policy, extack);
1231 if (err)
1232 return err;
1233
1234 for (i = 0; i <= NETCONFA_MAX; i++) {
1235 if (!tb[i])
1236 continue;
1237
1238 switch (i) {
1239 case NETCONFA_IFINDEX:
1240 break;
1241 default:
1242 NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in netconf get request");
1243 return -EINVAL;
1244 }
1245 }
1246
1247 return 0;
1248 }
1249
mpls_netconf_get_devconf(struct sk_buff * in_skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack)1250 static int mpls_netconf_get_devconf(struct sk_buff *in_skb,
1251 struct nlmsghdr *nlh,
1252 struct netlink_ext_ack *extack)
1253 {
1254 struct net *net = sock_net(in_skb->sk);
1255 struct nlattr *tb[NETCONFA_MAX + 1];
1256 struct net_device *dev;
1257 struct mpls_dev *mdev;
1258 struct sk_buff *skb;
1259 int ifindex;
1260 int err;
1261
1262 err = mpls_netconf_valid_get_req(in_skb, nlh, tb, extack);
1263 if (err < 0)
1264 goto errout;
1265
1266 err = -EINVAL;
1267 if (!tb[NETCONFA_IFINDEX])
1268 goto errout;
1269
1270 ifindex = nla_get_s32(tb[NETCONFA_IFINDEX]);
1271 dev = __dev_get_by_index(net, ifindex);
1272 if (!dev)
1273 goto errout;
1274
1275 mdev = mpls_dev_get(dev);
1276 if (!mdev)
1277 goto errout;
1278
1279 err = -ENOBUFS;
1280 skb = nlmsg_new(mpls_netconf_msgsize_devconf(NETCONFA_ALL), GFP_KERNEL);
1281 if (!skb)
1282 goto errout;
1283
1284 err = mpls_netconf_fill_devconf(skb, mdev,
1285 NETLINK_CB(in_skb).portid,
1286 nlh->nlmsg_seq, RTM_NEWNETCONF, 0,
1287 NETCONFA_ALL);
1288 if (err < 0) {
1289 /* -EMSGSIZE implies BUG in mpls_netconf_msgsize_devconf() */
1290 WARN_ON(err == -EMSGSIZE);
1291 kfree_skb(skb);
1292 goto errout;
1293 }
1294 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
1295 errout:
1296 return err;
1297 }
1298
mpls_netconf_dump_devconf(struct sk_buff * skb,struct netlink_callback * cb)1299 static int mpls_netconf_dump_devconf(struct sk_buff *skb,
1300 struct netlink_callback *cb)
1301 {
1302 const struct nlmsghdr *nlh = cb->nlh;
1303 struct net *net = sock_net(skb->sk);
1304 struct hlist_head *head;
1305 struct net_device *dev;
1306 struct mpls_dev *mdev;
1307 int idx, s_idx;
1308 int h, s_h;
1309
1310 if (cb->strict_check) {
1311 struct netlink_ext_ack *extack = cb->extack;
1312 struct netconfmsg *ncm;
1313
1314 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ncm))) {
1315 NL_SET_ERR_MSG_MOD(extack, "Invalid header for netconf dump request");
1316 return -EINVAL;
1317 }
1318
1319 if (nlmsg_attrlen(nlh, sizeof(*ncm))) {
1320 NL_SET_ERR_MSG_MOD(extack, "Invalid data after header in netconf dump request");
1321 return -EINVAL;
1322 }
1323 }
1324
1325 s_h = cb->args[0];
1326 s_idx = idx = cb->args[1];
1327
1328 for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {
1329 idx = 0;
1330 head = &net->dev_index_head[h];
1331 rcu_read_lock();
1332 cb->seq = net->dev_base_seq;
1333 hlist_for_each_entry_rcu(dev, head, index_hlist) {
1334 if (idx < s_idx)
1335 goto cont;
1336 mdev = mpls_dev_get(dev);
1337 if (!mdev)
1338 goto cont;
1339 if (mpls_netconf_fill_devconf(skb, mdev,
1340 NETLINK_CB(cb->skb).portid,
1341 nlh->nlmsg_seq,
1342 RTM_NEWNETCONF,
1343 NLM_F_MULTI,
1344 NETCONFA_ALL) < 0) {
1345 rcu_read_unlock();
1346 goto done;
1347 }
1348 nl_dump_check_consistent(cb, nlmsg_hdr(skb));
1349 cont:
1350 idx++;
1351 }
1352 rcu_read_unlock();
1353 }
1354 done:
1355 cb->args[0] = h;
1356 cb->args[1] = idx;
1357
1358 return skb->len;
1359 }
1360
1361 #define MPLS_PERDEV_SYSCTL_OFFSET(field) \
1362 (&((struct mpls_dev *)0)->field)
1363
mpls_conf_proc(struct ctl_table * ctl,int write,void * buffer,size_t * lenp,loff_t * ppos)1364 static int mpls_conf_proc(struct ctl_table *ctl, int write,
1365 void *buffer, size_t *lenp, loff_t *ppos)
1366 {
1367 int oval = *(int *)ctl->data;
1368 int ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
1369
1370 if (write) {
1371 struct mpls_dev *mdev = ctl->extra1;
1372 int i = (int *)ctl->data - (int *)mdev;
1373 struct net *net = ctl->extra2;
1374 int val = *(int *)ctl->data;
1375
1376 if (i == offsetof(struct mpls_dev, input_enabled) &&
1377 val != oval) {
1378 mpls_netconf_notify_devconf(net, RTM_NEWNETCONF,
1379 NETCONFA_INPUT, mdev);
1380 }
1381 }
1382
1383 return ret;
1384 }
1385
1386 static const struct ctl_table mpls_dev_table[] = {
1387 {
1388 .procname = "input",
1389 .maxlen = sizeof(int),
1390 .mode = 0644,
1391 .proc_handler = mpls_conf_proc,
1392 .data = MPLS_PERDEV_SYSCTL_OFFSET(input_enabled),
1393 },
1394 { }
1395 };
1396
mpls_dev_sysctl_register(struct net_device * dev,struct mpls_dev * mdev)1397 static int mpls_dev_sysctl_register(struct net_device *dev,
1398 struct mpls_dev *mdev)
1399 {
1400 char path[sizeof("net/mpls/conf/") + IFNAMSIZ];
1401 struct net *net = dev_net(dev);
1402 struct ctl_table *table;
1403 int i;
1404
1405 table = kmemdup(&mpls_dev_table, sizeof(mpls_dev_table), GFP_KERNEL);
1406 if (!table)
1407 goto out;
1408
1409 /* Table data contains only offsets relative to the base of
1410 * the mdev at this point, so make them absolute.
1411 */
1412 for (i = 0; i < ARRAY_SIZE(mpls_dev_table); i++) {
1413 table[i].data = (char *)mdev + (uintptr_t)table[i].data;
1414 table[i].extra1 = mdev;
1415 table[i].extra2 = net;
1416 }
1417
1418 snprintf(path, sizeof(path), "net/mpls/conf/%s", dev->name);
1419
1420 mdev->sysctl = register_net_sysctl(net, path, table);
1421 if (!mdev->sysctl)
1422 goto free;
1423
1424 mpls_netconf_notify_devconf(net, RTM_NEWNETCONF, NETCONFA_ALL, mdev);
1425 return 0;
1426
1427 free:
1428 kfree(table);
1429 out:
1430 mdev->sysctl = NULL;
1431 return -ENOBUFS;
1432 }
1433
mpls_dev_sysctl_unregister(struct net_device * dev,struct mpls_dev * mdev)1434 static void mpls_dev_sysctl_unregister(struct net_device *dev,
1435 struct mpls_dev *mdev)
1436 {
1437 struct net *net = dev_net(dev);
1438 struct ctl_table *table;
1439
1440 if (!mdev->sysctl)
1441 return;
1442
1443 table = mdev->sysctl->ctl_table_arg;
1444 unregister_net_sysctl_table(mdev->sysctl);
1445 kfree(table);
1446
1447 mpls_netconf_notify_devconf(net, RTM_DELNETCONF, 0, mdev);
1448 }
1449
mpls_add_dev(struct net_device * dev)1450 static struct mpls_dev *mpls_add_dev(struct net_device *dev)
1451 {
1452 struct mpls_dev *mdev;
1453 int err = -ENOMEM;
1454 int i;
1455
1456 ASSERT_RTNL();
1457
1458 mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
1459 if (!mdev)
1460 return ERR_PTR(err);
1461
1462 mdev->stats = alloc_percpu(struct mpls_pcpu_stats);
1463 if (!mdev->stats)
1464 goto free;
1465
1466 for_each_possible_cpu(i) {
1467 struct mpls_pcpu_stats *mpls_stats;
1468
1469 mpls_stats = per_cpu_ptr(mdev->stats, i);
1470 u64_stats_init(&mpls_stats->syncp);
1471 }
1472
1473 mdev->dev = dev;
1474
1475 err = mpls_dev_sysctl_register(dev, mdev);
1476 if (err)
1477 goto free;
1478
1479 rcu_assign_pointer(dev->mpls_ptr, mdev);
1480
1481 return mdev;
1482
1483 free:
1484 free_percpu(mdev->stats);
1485 kfree(mdev);
1486 return ERR_PTR(err);
1487 }
1488
mpls_dev_destroy_rcu(struct rcu_head * head)1489 static void mpls_dev_destroy_rcu(struct rcu_head *head)
1490 {
1491 struct mpls_dev *mdev = container_of(head, struct mpls_dev, rcu);
1492
1493 free_percpu(mdev->stats);
1494 kfree(mdev);
1495 }
1496
mpls_ifdown(struct net_device * dev,int event)1497 static int mpls_ifdown(struct net_device *dev, int event)
1498 {
1499 struct mpls_route __rcu **platform_label;
1500 struct net *net = dev_net(dev);
1501 unsigned index;
1502
1503 platform_label = rtnl_dereference(net->mpls.platform_label);
1504 for (index = 0; index < net->mpls.platform_labels; index++) {
1505 struct mpls_route *rt = rtnl_dereference(platform_label[index]);
1506 bool nh_del = false;
1507 u8 alive = 0;
1508
1509 if (!rt)
1510 continue;
1511
1512 if (event == NETDEV_UNREGISTER) {
1513 u8 deleted = 0;
1514
1515 for_nexthops(rt) {
1516 struct net_device *nh_dev =
1517 rtnl_dereference(nh->nh_dev);
1518
1519 if (!nh_dev || nh_dev == dev)
1520 deleted++;
1521 if (nh_dev == dev)
1522 nh_del = true;
1523 } endfor_nexthops(rt);
1524
1525 /* if there are no more nexthops, delete the route */
1526 if (deleted == rt->rt_nhn) {
1527 mpls_route_update(net, index, NULL, NULL);
1528 continue;
1529 }
1530
1531 if (nh_del) {
1532 size_t size = sizeof(*rt) + rt->rt_nhn *
1533 rt->rt_nh_size;
1534 struct mpls_route *orig = rt;
1535
1536 rt = kmalloc(size, GFP_KERNEL);
1537 if (!rt)
1538 return -ENOMEM;
1539 memcpy(rt, orig, size);
1540 }
1541 }
1542
1543 change_nexthops(rt) {
1544 unsigned int nh_flags = nh->nh_flags;
1545
1546 if (rtnl_dereference(nh->nh_dev) != dev)
1547 goto next;
1548
1549 switch (event) {
1550 case NETDEV_DOWN:
1551 case NETDEV_UNREGISTER:
1552 nh_flags |= RTNH_F_DEAD;
1553 fallthrough;
1554 case NETDEV_CHANGE:
1555 nh_flags |= RTNH_F_LINKDOWN;
1556 break;
1557 }
1558 if (event == NETDEV_UNREGISTER)
1559 RCU_INIT_POINTER(nh->nh_dev, NULL);
1560
1561 if (nh->nh_flags != nh_flags)
1562 WRITE_ONCE(nh->nh_flags, nh_flags);
1563 next:
1564 if (!(nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)))
1565 alive++;
1566 } endfor_nexthops(rt);
1567
1568 WRITE_ONCE(rt->rt_nhn_alive, alive);
1569
1570 if (nh_del)
1571 mpls_route_update(net, index, rt, NULL);
1572 }
1573
1574 return 0;
1575 }
1576
mpls_ifup(struct net_device * dev,unsigned int flags)1577 static void mpls_ifup(struct net_device *dev, unsigned int flags)
1578 {
1579 struct mpls_route __rcu **platform_label;
1580 struct net *net = dev_net(dev);
1581 unsigned index;
1582 u8 alive;
1583
1584 platform_label = rtnl_dereference(net->mpls.platform_label);
1585 for (index = 0; index < net->mpls.platform_labels; index++) {
1586 struct mpls_route *rt = rtnl_dereference(platform_label[index]);
1587
1588 if (!rt)
1589 continue;
1590
1591 alive = 0;
1592 change_nexthops(rt) {
1593 unsigned int nh_flags = nh->nh_flags;
1594 struct net_device *nh_dev =
1595 rtnl_dereference(nh->nh_dev);
1596
1597 if (!(nh_flags & flags)) {
1598 alive++;
1599 continue;
1600 }
1601 if (nh_dev != dev)
1602 continue;
1603 alive++;
1604 nh_flags &= ~flags;
1605 WRITE_ONCE(nh->nh_flags, nh_flags);
1606 } endfor_nexthops(rt);
1607
1608 WRITE_ONCE(rt->rt_nhn_alive, alive);
1609 }
1610 }
1611
mpls_dev_notify(struct notifier_block * this,unsigned long event,void * ptr)1612 static int mpls_dev_notify(struct notifier_block *this, unsigned long event,
1613 void *ptr)
1614 {
1615 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1616 struct mpls_dev *mdev;
1617 unsigned int flags;
1618
1619 if (event == NETDEV_REGISTER) {
1620 mdev = mpls_add_dev(dev);
1621 if (IS_ERR(mdev))
1622 return notifier_from_errno(PTR_ERR(mdev));
1623
1624 return NOTIFY_OK;
1625 }
1626
1627 mdev = mpls_dev_get(dev);
1628 if (!mdev)
1629 return NOTIFY_OK;
1630
1631 switch (event) {
1632 int err;
1633
1634 case NETDEV_DOWN:
1635 err = mpls_ifdown(dev, event);
1636 if (err)
1637 return notifier_from_errno(err);
1638 break;
1639 case NETDEV_UP:
1640 flags = dev_get_flags(dev);
1641 if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1642 mpls_ifup(dev, RTNH_F_DEAD | RTNH_F_LINKDOWN);
1643 else
1644 mpls_ifup(dev, RTNH_F_DEAD);
1645 break;
1646 case NETDEV_CHANGE:
1647 flags = dev_get_flags(dev);
1648 if (flags & (IFF_RUNNING | IFF_LOWER_UP)) {
1649 mpls_ifup(dev, RTNH_F_DEAD | RTNH_F_LINKDOWN);
1650 } else {
1651 err = mpls_ifdown(dev, event);
1652 if (err)
1653 return notifier_from_errno(err);
1654 }
1655 break;
1656 case NETDEV_UNREGISTER:
1657 err = mpls_ifdown(dev, event);
1658 if (err)
1659 return notifier_from_errno(err);
1660 mdev = mpls_dev_get(dev);
1661 if (mdev) {
1662 mpls_dev_sysctl_unregister(dev, mdev);
1663 RCU_INIT_POINTER(dev->mpls_ptr, NULL);
1664 call_rcu(&mdev->rcu, mpls_dev_destroy_rcu);
1665 }
1666 break;
1667 case NETDEV_CHANGENAME:
1668 mdev = mpls_dev_get(dev);
1669 if (mdev) {
1670 mpls_dev_sysctl_unregister(dev, mdev);
1671 err = mpls_dev_sysctl_register(dev, mdev);
1672 if (err)
1673 return notifier_from_errno(err);
1674 }
1675 break;
1676 }
1677 return NOTIFY_OK;
1678 }
1679
1680 static struct notifier_block mpls_dev_notifier = {
1681 .notifier_call = mpls_dev_notify,
1682 };
1683
nla_put_via(struct sk_buff * skb,u8 table,const void * addr,int alen)1684 static int nla_put_via(struct sk_buff *skb,
1685 u8 table, const void *addr, int alen)
1686 {
1687 static const int table_to_family[NEIGH_NR_TABLES + 1] = {
1688 AF_INET, AF_INET6, AF_DECnet, AF_PACKET,
1689 };
1690 struct nlattr *nla;
1691 struct rtvia *via;
1692 int family = AF_UNSPEC;
1693
1694 nla = nla_reserve(skb, RTA_VIA, alen + 2);
1695 if (!nla)
1696 return -EMSGSIZE;
1697
1698 if (table <= NEIGH_NR_TABLES)
1699 family = table_to_family[table];
1700
1701 via = nla_data(nla);
1702 via->rtvia_family = family;
1703 memcpy(via->rtvia_addr, addr, alen);
1704 return 0;
1705 }
1706
nla_put_labels(struct sk_buff * skb,int attrtype,u8 labels,const u32 label[])1707 int nla_put_labels(struct sk_buff *skb, int attrtype,
1708 u8 labels, const u32 label[])
1709 {
1710 struct nlattr *nla;
1711 struct mpls_shim_hdr *nla_label;
1712 bool bos;
1713 int i;
1714 nla = nla_reserve(skb, attrtype, labels*4);
1715 if (!nla)
1716 return -EMSGSIZE;
1717
1718 nla_label = nla_data(nla);
1719 bos = true;
1720 for (i = labels - 1; i >= 0; i--) {
1721 nla_label[i] = mpls_entry_encode(label[i], 0, 0, bos);
1722 bos = false;
1723 }
1724
1725 return 0;
1726 }
1727 EXPORT_SYMBOL_GPL(nla_put_labels);
1728
nla_get_labels(const struct nlattr * nla,u8 max_labels,u8 * labels,u32 label[],struct netlink_ext_ack * extack)1729 int nla_get_labels(const struct nlattr *nla, u8 max_labels, u8 *labels,
1730 u32 label[], struct netlink_ext_ack *extack)
1731 {
1732 unsigned len = nla_len(nla);
1733 struct mpls_shim_hdr *nla_label;
1734 u8 nla_labels;
1735 bool bos;
1736 int i;
1737
1738 /* len needs to be an even multiple of 4 (the label size). Number
1739 * of labels is a u8 so check for overflow.
1740 */
1741 if (len & 3 || len / 4 > 255) {
1742 NL_SET_ERR_MSG_ATTR(extack, nla,
1743 "Invalid length for labels attribute");
1744 return -EINVAL;
1745 }
1746
1747 /* Limit the number of new labels allowed */
1748 nla_labels = len/4;
1749 if (nla_labels > max_labels) {
1750 NL_SET_ERR_MSG(extack, "Too many labels");
1751 return -EINVAL;
1752 }
1753
1754 /* when label == NULL, caller wants number of labels */
1755 if (!label)
1756 goto out;
1757
1758 nla_label = nla_data(nla);
1759 bos = true;
1760 for (i = nla_labels - 1; i >= 0; i--, bos = false) {
1761 struct mpls_entry_decoded dec;
1762 dec = mpls_entry_decode(nla_label + i);
1763
1764 /* Ensure the bottom of stack flag is properly set
1765 * and ttl and tc are both clear.
1766 */
1767 if (dec.ttl) {
1768 NL_SET_ERR_MSG_ATTR(extack, nla,
1769 "TTL in label must be 0");
1770 return -EINVAL;
1771 }
1772
1773 if (dec.tc) {
1774 NL_SET_ERR_MSG_ATTR(extack, nla,
1775 "Traffic class in label must be 0");
1776 return -EINVAL;
1777 }
1778
1779 if (dec.bos != bos) {
1780 NL_SET_BAD_ATTR(extack, nla);
1781 if (bos) {
1782 NL_SET_ERR_MSG(extack,
1783 "BOS bit must be set in first label");
1784 } else {
1785 NL_SET_ERR_MSG(extack,
1786 "BOS bit can only be set in first label");
1787 }
1788 return -EINVAL;
1789 }
1790
1791 switch (dec.label) {
1792 case MPLS_LABEL_IMPLNULL:
1793 /* RFC3032: This is a label that an LSR may
1794 * assign and distribute, but which never
1795 * actually appears in the encapsulation.
1796 */
1797 NL_SET_ERR_MSG_ATTR(extack, nla,
1798 "Implicit NULL Label (3) can not be used in encapsulation");
1799 return -EINVAL;
1800 }
1801
1802 label[i] = dec.label;
1803 }
1804 out:
1805 *labels = nla_labels;
1806 return 0;
1807 }
1808 EXPORT_SYMBOL_GPL(nla_get_labels);
1809
rtm_to_route_config(struct sk_buff * skb,struct nlmsghdr * nlh,struct mpls_route_config * cfg,struct netlink_ext_ack * extack)1810 static int rtm_to_route_config(struct sk_buff *skb,
1811 struct nlmsghdr *nlh,
1812 struct mpls_route_config *cfg,
1813 struct netlink_ext_ack *extack)
1814 {
1815 struct rtmsg *rtm;
1816 struct nlattr *tb[RTA_MAX+1];
1817 int index;
1818 int err;
1819
1820 err = nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
1821 rtm_mpls_policy, extack);
1822 if (err < 0)
1823 goto errout;
1824
1825 err = -EINVAL;
1826 rtm = nlmsg_data(nlh);
1827
1828 if (rtm->rtm_family != AF_MPLS) {
1829 NL_SET_ERR_MSG(extack, "Invalid address family in rtmsg");
1830 goto errout;
1831 }
1832 if (rtm->rtm_dst_len != 20) {
1833 NL_SET_ERR_MSG(extack, "rtm_dst_len must be 20 for MPLS");
1834 goto errout;
1835 }
1836 if (rtm->rtm_src_len != 0) {
1837 NL_SET_ERR_MSG(extack, "rtm_src_len must be 0 for MPLS");
1838 goto errout;
1839 }
1840 if (rtm->rtm_tos != 0) {
1841 NL_SET_ERR_MSG(extack, "rtm_tos must be 0 for MPLS");
1842 goto errout;
1843 }
1844 if (rtm->rtm_table != RT_TABLE_MAIN) {
1845 NL_SET_ERR_MSG(extack,
1846 "MPLS only supports the main route table");
1847 goto errout;
1848 }
1849 /* Any value is acceptable for rtm_protocol */
1850
1851 /* As mpls uses destination specific addresses
1852 * (or source specific address in the case of multicast)
1853 * all addresses have universal scope.
1854 */
1855 if (rtm->rtm_scope != RT_SCOPE_UNIVERSE) {
1856 NL_SET_ERR_MSG(extack,
1857 "Invalid route scope - MPLS only supports UNIVERSE");
1858 goto errout;
1859 }
1860 if (rtm->rtm_type != RTN_UNICAST) {
1861 NL_SET_ERR_MSG(extack,
1862 "Invalid route type - MPLS only supports UNICAST");
1863 goto errout;
1864 }
1865 if (rtm->rtm_flags != 0) {
1866 NL_SET_ERR_MSG(extack, "rtm_flags must be 0 for MPLS");
1867 goto errout;
1868 }
1869
1870 cfg->rc_label = LABEL_NOT_SPECIFIED;
1871 cfg->rc_protocol = rtm->rtm_protocol;
1872 cfg->rc_via_table = MPLS_NEIGH_TABLE_UNSPEC;
1873 cfg->rc_ttl_propagate = MPLS_TTL_PROP_DEFAULT;
1874 cfg->rc_nlflags = nlh->nlmsg_flags;
1875 cfg->rc_nlinfo.portid = NETLINK_CB(skb).portid;
1876 cfg->rc_nlinfo.nlh = nlh;
1877 cfg->rc_nlinfo.nl_net = sock_net(skb->sk);
1878
1879 for (index = 0; index <= RTA_MAX; index++) {
1880 struct nlattr *nla = tb[index];
1881 if (!nla)
1882 continue;
1883
1884 switch (index) {
1885 case RTA_OIF:
1886 cfg->rc_ifindex = nla_get_u32(nla);
1887 break;
1888 case RTA_NEWDST:
1889 if (nla_get_labels(nla, MAX_NEW_LABELS,
1890 &cfg->rc_output_labels,
1891 cfg->rc_output_label, extack))
1892 goto errout;
1893 break;
1894 case RTA_DST:
1895 {
1896 u8 label_count;
1897 if (nla_get_labels(nla, 1, &label_count,
1898 &cfg->rc_label, extack))
1899 goto errout;
1900
1901 if (!mpls_label_ok(cfg->rc_nlinfo.nl_net,
1902 &cfg->rc_label, extack))
1903 goto errout;
1904 break;
1905 }
1906 case RTA_GATEWAY:
1907 NL_SET_ERR_MSG(extack, "MPLS does not support RTA_GATEWAY attribute");
1908 goto errout;
1909 case RTA_VIA:
1910 {
1911 if (nla_get_via(nla, &cfg->rc_via_alen,
1912 &cfg->rc_via_table, cfg->rc_via,
1913 extack))
1914 goto errout;
1915 break;
1916 }
1917 case RTA_MULTIPATH:
1918 {
1919 cfg->rc_mp = nla_data(nla);
1920 cfg->rc_mp_len = nla_len(nla);
1921 break;
1922 }
1923 case RTA_TTL_PROPAGATE:
1924 {
1925 u8 ttl_propagate = nla_get_u8(nla);
1926
1927 if (ttl_propagate > 1) {
1928 NL_SET_ERR_MSG_ATTR(extack, nla,
1929 "RTA_TTL_PROPAGATE can only be 0 or 1");
1930 goto errout;
1931 }
1932 cfg->rc_ttl_propagate = ttl_propagate ?
1933 MPLS_TTL_PROP_ENABLED :
1934 MPLS_TTL_PROP_DISABLED;
1935 break;
1936 }
1937 default:
1938 NL_SET_ERR_MSG_ATTR(extack, nla, "Unknown attribute");
1939 /* Unsupported attribute */
1940 goto errout;
1941 }
1942 }
1943
1944 err = 0;
1945 errout:
1946 return err;
1947 }
1948
mpls_rtm_delroute(struct sk_buff * skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack)1949 static int mpls_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
1950 struct netlink_ext_ack *extack)
1951 {
1952 struct mpls_route_config *cfg;
1953 int err;
1954
1955 cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
1956 if (!cfg)
1957 return -ENOMEM;
1958
1959 err = rtm_to_route_config(skb, nlh, cfg, extack);
1960 if (err < 0)
1961 goto out;
1962
1963 err = mpls_route_del(cfg, extack);
1964 out:
1965 kfree(cfg);
1966
1967 return err;
1968 }
1969
1970
mpls_rtm_newroute(struct sk_buff * skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack)1971 static int mpls_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
1972 struct netlink_ext_ack *extack)
1973 {
1974 struct mpls_route_config *cfg;
1975 int err;
1976
1977 cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
1978 if (!cfg)
1979 return -ENOMEM;
1980
1981 err = rtm_to_route_config(skb, nlh, cfg, extack);
1982 if (err < 0)
1983 goto out;
1984
1985 err = mpls_route_add(cfg, extack);
1986 out:
1987 kfree(cfg);
1988
1989 return err;
1990 }
1991
mpls_dump_route(struct sk_buff * skb,u32 portid,u32 seq,int event,u32 label,struct mpls_route * rt,int flags)1992 static int mpls_dump_route(struct sk_buff *skb, u32 portid, u32 seq, int event,
1993 u32 label, struct mpls_route *rt, int flags)
1994 {
1995 struct net_device *dev;
1996 struct nlmsghdr *nlh;
1997 struct rtmsg *rtm;
1998
1999 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), flags);
2000 if (nlh == NULL)
2001 return -EMSGSIZE;
2002
2003 rtm = nlmsg_data(nlh);
2004 rtm->rtm_family = AF_MPLS;
2005 rtm->rtm_dst_len = 20;
2006 rtm->rtm_src_len = 0;
2007 rtm->rtm_tos = 0;
2008 rtm->rtm_table = RT_TABLE_MAIN;
2009 rtm->rtm_protocol = rt->rt_protocol;
2010 rtm->rtm_scope = RT_SCOPE_UNIVERSE;
2011 rtm->rtm_type = RTN_UNICAST;
2012 rtm->rtm_flags = 0;
2013
2014 if (nla_put_labels(skb, RTA_DST, 1, &label))
2015 goto nla_put_failure;
2016
2017 if (rt->rt_ttl_propagate != MPLS_TTL_PROP_DEFAULT) {
2018 bool ttl_propagate =
2019 rt->rt_ttl_propagate == MPLS_TTL_PROP_ENABLED;
2020
2021 if (nla_put_u8(skb, RTA_TTL_PROPAGATE,
2022 ttl_propagate))
2023 goto nla_put_failure;
2024 }
2025 if (rt->rt_nhn == 1) {
2026 const struct mpls_nh *nh = rt->rt_nh;
2027
2028 if (nh->nh_labels &&
2029 nla_put_labels(skb, RTA_NEWDST, nh->nh_labels,
2030 nh->nh_label))
2031 goto nla_put_failure;
2032 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC &&
2033 nla_put_via(skb, nh->nh_via_table, mpls_nh_via(rt, nh),
2034 nh->nh_via_alen))
2035 goto nla_put_failure;
2036 dev = rtnl_dereference(nh->nh_dev);
2037 if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex))
2038 goto nla_put_failure;
2039 if (nh->nh_flags & RTNH_F_LINKDOWN)
2040 rtm->rtm_flags |= RTNH_F_LINKDOWN;
2041 if (nh->nh_flags & RTNH_F_DEAD)
2042 rtm->rtm_flags |= RTNH_F_DEAD;
2043 } else {
2044 struct rtnexthop *rtnh;
2045 struct nlattr *mp;
2046 u8 linkdown = 0;
2047 u8 dead = 0;
2048
2049 mp = nla_nest_start_noflag(skb, RTA_MULTIPATH);
2050 if (!mp)
2051 goto nla_put_failure;
2052
2053 for_nexthops(rt) {
2054 dev = rtnl_dereference(nh->nh_dev);
2055 if (!dev)
2056 continue;
2057
2058 rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh));
2059 if (!rtnh)
2060 goto nla_put_failure;
2061
2062 rtnh->rtnh_ifindex = dev->ifindex;
2063 if (nh->nh_flags & RTNH_F_LINKDOWN) {
2064 rtnh->rtnh_flags |= RTNH_F_LINKDOWN;
2065 linkdown++;
2066 }
2067 if (nh->nh_flags & RTNH_F_DEAD) {
2068 rtnh->rtnh_flags |= RTNH_F_DEAD;
2069 dead++;
2070 }
2071
2072 if (nh->nh_labels && nla_put_labels(skb, RTA_NEWDST,
2073 nh->nh_labels,
2074 nh->nh_label))
2075 goto nla_put_failure;
2076 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC &&
2077 nla_put_via(skb, nh->nh_via_table,
2078 mpls_nh_via(rt, nh),
2079 nh->nh_via_alen))
2080 goto nla_put_failure;
2081
2082 /* length of rtnetlink header + attributes */
2083 rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *)rtnh;
2084 } endfor_nexthops(rt);
2085
2086 if (linkdown == rt->rt_nhn)
2087 rtm->rtm_flags |= RTNH_F_LINKDOWN;
2088 if (dead == rt->rt_nhn)
2089 rtm->rtm_flags |= RTNH_F_DEAD;
2090
2091 nla_nest_end(skb, mp);
2092 }
2093
2094 nlmsg_end(skb, nlh);
2095 return 0;
2096
2097 nla_put_failure:
2098 nlmsg_cancel(skb, nlh);
2099 return -EMSGSIZE;
2100 }
2101
2102 #if IS_ENABLED(CONFIG_INET)
mpls_valid_fib_dump_req(struct net * net,const struct nlmsghdr * nlh,struct fib_dump_filter * filter,struct netlink_callback * cb)2103 static int mpls_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
2104 struct fib_dump_filter *filter,
2105 struct netlink_callback *cb)
2106 {
2107 return ip_valid_fib_dump_req(net, nlh, filter, cb);
2108 }
2109 #else
mpls_valid_fib_dump_req(struct net * net,const struct nlmsghdr * nlh,struct fib_dump_filter * filter,struct netlink_callback * cb)2110 static int mpls_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
2111 struct fib_dump_filter *filter,
2112 struct netlink_callback *cb)
2113 {
2114 struct netlink_ext_ack *extack = cb->extack;
2115 struct nlattr *tb[RTA_MAX + 1];
2116 struct rtmsg *rtm;
2117 int err, i;
2118
2119 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
2120 NL_SET_ERR_MSG_MOD(extack, "Invalid header for FIB dump request");
2121 return -EINVAL;
2122 }
2123
2124 rtm = nlmsg_data(nlh);
2125 if (rtm->rtm_dst_len || rtm->rtm_src_len || rtm->rtm_tos ||
2126 rtm->rtm_table || rtm->rtm_scope || rtm->rtm_type ||
2127 rtm->rtm_flags) {
2128 NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for FIB dump request");
2129 return -EINVAL;
2130 }
2131
2132 if (rtm->rtm_protocol) {
2133 filter->protocol = rtm->rtm_protocol;
2134 filter->filter_set = 1;
2135 cb->answer_flags = NLM_F_DUMP_FILTERED;
2136 }
2137
2138 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
2139 rtm_mpls_policy, extack);
2140 if (err < 0)
2141 return err;
2142
2143 for (i = 0; i <= RTA_MAX; ++i) {
2144 int ifindex;
2145
2146 if (i == RTA_OIF) {
2147 ifindex = nla_get_u32(tb[i]);
2148 filter->dev = __dev_get_by_index(net, ifindex);
2149 if (!filter->dev)
2150 return -ENODEV;
2151 filter->filter_set = 1;
2152 } else if (tb[i]) {
2153 NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in dump request");
2154 return -EINVAL;
2155 }
2156 }
2157
2158 return 0;
2159 }
2160 #endif
2161
mpls_rt_uses_dev(struct mpls_route * rt,const struct net_device * dev)2162 static bool mpls_rt_uses_dev(struct mpls_route *rt,
2163 const struct net_device *dev)
2164 {
2165 struct net_device *nh_dev;
2166
2167 if (rt->rt_nhn == 1) {
2168 struct mpls_nh *nh = rt->rt_nh;
2169
2170 nh_dev = rtnl_dereference(nh->nh_dev);
2171 if (dev == nh_dev)
2172 return true;
2173 } else {
2174 for_nexthops(rt) {
2175 nh_dev = rtnl_dereference(nh->nh_dev);
2176 if (nh_dev == dev)
2177 return true;
2178 } endfor_nexthops(rt);
2179 }
2180
2181 return false;
2182 }
2183
mpls_dump_routes(struct sk_buff * skb,struct netlink_callback * cb)2184 static int mpls_dump_routes(struct sk_buff *skb, struct netlink_callback *cb)
2185 {
2186 const struct nlmsghdr *nlh = cb->nlh;
2187 struct net *net = sock_net(skb->sk);
2188 struct mpls_route __rcu **platform_label;
2189 struct fib_dump_filter filter = {};
2190 unsigned int flags = NLM_F_MULTI;
2191 size_t platform_labels;
2192 unsigned int index;
2193
2194 ASSERT_RTNL();
2195
2196 if (cb->strict_check) {
2197 int err;
2198
2199 err = mpls_valid_fib_dump_req(net, nlh, &filter, cb);
2200 if (err < 0)
2201 return err;
2202
2203 /* for MPLS, there is only 1 table with fixed type and flags.
2204 * If either are set in the filter then return nothing.
2205 */
2206 if ((filter.table_id && filter.table_id != RT_TABLE_MAIN) ||
2207 (filter.rt_type && filter.rt_type != RTN_UNICAST) ||
2208 filter.flags)
2209 return skb->len;
2210 }
2211
2212 index = cb->args[0];
2213 if (index < MPLS_LABEL_FIRST_UNRESERVED)
2214 index = MPLS_LABEL_FIRST_UNRESERVED;
2215
2216 platform_label = rtnl_dereference(net->mpls.platform_label);
2217 platform_labels = net->mpls.platform_labels;
2218
2219 if (filter.filter_set)
2220 flags |= NLM_F_DUMP_FILTERED;
2221
2222 for (; index < platform_labels; index++) {
2223 struct mpls_route *rt;
2224
2225 rt = rtnl_dereference(platform_label[index]);
2226 if (!rt)
2227 continue;
2228
2229 if ((filter.dev && !mpls_rt_uses_dev(rt, filter.dev)) ||
2230 (filter.protocol && rt->rt_protocol != filter.protocol))
2231 continue;
2232
2233 if (mpls_dump_route(skb, NETLINK_CB(cb->skb).portid,
2234 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
2235 index, rt, flags) < 0)
2236 break;
2237 }
2238 cb->args[0] = index;
2239
2240 return skb->len;
2241 }
2242
lfib_nlmsg_size(struct mpls_route * rt)2243 static inline size_t lfib_nlmsg_size(struct mpls_route *rt)
2244 {
2245 size_t payload =
2246 NLMSG_ALIGN(sizeof(struct rtmsg))
2247 + nla_total_size(4) /* RTA_DST */
2248 + nla_total_size(1); /* RTA_TTL_PROPAGATE */
2249
2250 if (rt->rt_nhn == 1) {
2251 struct mpls_nh *nh = rt->rt_nh;
2252
2253 if (nh->nh_dev)
2254 payload += nla_total_size(4); /* RTA_OIF */
2255 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC) /* RTA_VIA */
2256 payload += nla_total_size(2 + nh->nh_via_alen);
2257 if (nh->nh_labels) /* RTA_NEWDST */
2258 payload += nla_total_size(nh->nh_labels * 4);
2259 } else {
2260 /* each nexthop is packed in an attribute */
2261 size_t nhsize = 0;
2262
2263 for_nexthops(rt) {
2264 if (!rtnl_dereference(nh->nh_dev))
2265 continue;
2266 nhsize += nla_total_size(sizeof(struct rtnexthop));
2267 /* RTA_VIA */
2268 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC)
2269 nhsize += nla_total_size(2 + nh->nh_via_alen);
2270 if (nh->nh_labels)
2271 nhsize += nla_total_size(nh->nh_labels * 4);
2272 } endfor_nexthops(rt);
2273 /* nested attribute */
2274 payload += nla_total_size(nhsize);
2275 }
2276
2277 return payload;
2278 }
2279
rtmsg_lfib(int event,u32 label,struct mpls_route * rt,struct nlmsghdr * nlh,struct net * net,u32 portid,unsigned int nlm_flags)2280 static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt,
2281 struct nlmsghdr *nlh, struct net *net, u32 portid,
2282 unsigned int nlm_flags)
2283 {
2284 struct sk_buff *skb;
2285 u32 seq = nlh ? nlh->nlmsg_seq : 0;
2286 int err = -ENOBUFS;
2287
2288 skb = nlmsg_new(lfib_nlmsg_size(rt), GFP_KERNEL);
2289 if (skb == NULL)
2290 goto errout;
2291
2292 err = mpls_dump_route(skb, portid, seq, event, label, rt, nlm_flags);
2293 if (err < 0) {
2294 /* -EMSGSIZE implies BUG in lfib_nlmsg_size */
2295 WARN_ON(err == -EMSGSIZE);
2296 kfree_skb(skb);
2297 goto errout;
2298 }
2299 rtnl_notify(skb, net, portid, RTNLGRP_MPLS_ROUTE, nlh, GFP_KERNEL);
2300
2301 return;
2302 errout:
2303 if (err < 0)
2304 rtnl_set_sk_err(net, RTNLGRP_MPLS_ROUTE, err);
2305 }
2306
mpls_valid_getroute_req(struct sk_buff * skb,const struct nlmsghdr * nlh,struct nlattr ** tb,struct netlink_ext_ack * extack)2307 static int mpls_valid_getroute_req(struct sk_buff *skb,
2308 const struct nlmsghdr *nlh,
2309 struct nlattr **tb,
2310 struct netlink_ext_ack *extack)
2311 {
2312 struct rtmsg *rtm;
2313 int i, err;
2314
2315 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
2316 NL_SET_ERR_MSG_MOD(extack,
2317 "Invalid header for get route request");
2318 return -EINVAL;
2319 }
2320
2321 if (!netlink_strict_get_check(skb))
2322 return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
2323 rtm_mpls_policy, extack);
2324
2325 rtm = nlmsg_data(nlh);
2326 if ((rtm->rtm_dst_len && rtm->rtm_dst_len != 20) ||
2327 rtm->rtm_src_len || rtm->rtm_tos || rtm->rtm_table ||
2328 rtm->rtm_protocol || rtm->rtm_scope || rtm->rtm_type) {
2329 NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for get route request");
2330 return -EINVAL;
2331 }
2332 if (rtm->rtm_flags & ~RTM_F_FIB_MATCH) {
2333 NL_SET_ERR_MSG_MOD(extack,
2334 "Invalid flags for get route request");
2335 return -EINVAL;
2336 }
2337
2338 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
2339 rtm_mpls_policy, extack);
2340 if (err)
2341 return err;
2342
2343 if ((tb[RTA_DST] || tb[RTA_NEWDST]) && !rtm->rtm_dst_len) {
2344 NL_SET_ERR_MSG_MOD(extack, "rtm_dst_len must be 20 for MPLS");
2345 return -EINVAL;
2346 }
2347
2348 for (i = 0; i <= RTA_MAX; i++) {
2349 if (!tb[i])
2350 continue;
2351
2352 switch (i) {
2353 case RTA_DST:
2354 case RTA_NEWDST:
2355 break;
2356 default:
2357 NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in get route request");
2358 return -EINVAL;
2359 }
2360 }
2361
2362 return 0;
2363 }
2364
mpls_getroute(struct sk_buff * in_skb,struct nlmsghdr * in_nlh,struct netlink_ext_ack * extack)2365 static int mpls_getroute(struct sk_buff *in_skb, struct nlmsghdr *in_nlh,
2366 struct netlink_ext_ack *extack)
2367 {
2368 struct net *net = sock_net(in_skb->sk);
2369 u32 portid = NETLINK_CB(in_skb).portid;
2370 u32 in_label = LABEL_NOT_SPECIFIED;
2371 struct nlattr *tb[RTA_MAX + 1];
2372 u32 labels[MAX_NEW_LABELS];
2373 struct mpls_shim_hdr *hdr;
2374 unsigned int hdr_size = 0;
2375 struct net_device *dev;
2376 struct mpls_route *rt;
2377 struct rtmsg *rtm, *r;
2378 struct nlmsghdr *nlh;
2379 struct sk_buff *skb;
2380 struct mpls_nh *nh;
2381 u8 n_labels;
2382 int err;
2383
2384 err = mpls_valid_getroute_req(in_skb, in_nlh, tb, extack);
2385 if (err < 0)
2386 goto errout;
2387
2388 rtm = nlmsg_data(in_nlh);
2389
2390 if (tb[RTA_DST]) {
2391 u8 label_count;
2392
2393 if (nla_get_labels(tb[RTA_DST], 1, &label_count,
2394 &in_label, extack)) {
2395 err = -EINVAL;
2396 goto errout;
2397 }
2398
2399 if (!mpls_label_ok(net, &in_label, extack)) {
2400 err = -EINVAL;
2401 goto errout;
2402 }
2403 }
2404
2405 rt = mpls_route_input_rcu(net, in_label);
2406 if (!rt) {
2407 err = -ENETUNREACH;
2408 goto errout;
2409 }
2410
2411 if (rtm->rtm_flags & RTM_F_FIB_MATCH) {
2412 skb = nlmsg_new(lfib_nlmsg_size(rt), GFP_KERNEL);
2413 if (!skb) {
2414 err = -ENOBUFS;
2415 goto errout;
2416 }
2417
2418 err = mpls_dump_route(skb, portid, in_nlh->nlmsg_seq,
2419 RTM_NEWROUTE, in_label, rt, 0);
2420 if (err < 0) {
2421 /* -EMSGSIZE implies BUG in lfib_nlmsg_size */
2422 WARN_ON(err == -EMSGSIZE);
2423 goto errout_free;
2424 }
2425
2426 return rtnl_unicast(skb, net, portid);
2427 }
2428
2429 if (tb[RTA_NEWDST]) {
2430 if (nla_get_labels(tb[RTA_NEWDST], MAX_NEW_LABELS, &n_labels,
2431 labels, extack) != 0) {
2432 err = -EINVAL;
2433 goto errout;
2434 }
2435
2436 hdr_size = n_labels * sizeof(struct mpls_shim_hdr);
2437 }
2438
2439 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2440 if (!skb) {
2441 err = -ENOBUFS;
2442 goto errout;
2443 }
2444
2445 skb->protocol = htons(ETH_P_MPLS_UC);
2446
2447 if (hdr_size) {
2448 bool bos;
2449 int i;
2450
2451 if (skb_cow(skb, hdr_size)) {
2452 err = -ENOBUFS;
2453 goto errout_free;
2454 }
2455
2456 skb_reserve(skb, hdr_size);
2457 skb_push(skb, hdr_size);
2458 skb_reset_network_header(skb);
2459
2460 /* Push new labels */
2461 hdr = mpls_hdr(skb);
2462 bos = true;
2463 for (i = n_labels - 1; i >= 0; i--) {
2464 hdr[i] = mpls_entry_encode(labels[i],
2465 1, 0, bos);
2466 bos = false;
2467 }
2468 }
2469
2470 nh = mpls_select_multipath(rt, skb);
2471 if (!nh) {
2472 err = -ENETUNREACH;
2473 goto errout_free;
2474 }
2475
2476 if (hdr_size) {
2477 skb_pull(skb, hdr_size);
2478 skb_reset_network_header(skb);
2479 }
2480
2481 nlh = nlmsg_put(skb, portid, in_nlh->nlmsg_seq,
2482 RTM_NEWROUTE, sizeof(*r), 0);
2483 if (!nlh) {
2484 err = -EMSGSIZE;
2485 goto errout_free;
2486 }
2487
2488 r = nlmsg_data(nlh);
2489 r->rtm_family = AF_MPLS;
2490 r->rtm_dst_len = 20;
2491 r->rtm_src_len = 0;
2492 r->rtm_table = RT_TABLE_MAIN;
2493 r->rtm_type = RTN_UNICAST;
2494 r->rtm_scope = RT_SCOPE_UNIVERSE;
2495 r->rtm_protocol = rt->rt_protocol;
2496 r->rtm_flags = 0;
2497
2498 if (nla_put_labels(skb, RTA_DST, 1, &in_label))
2499 goto nla_put_failure;
2500
2501 if (nh->nh_labels &&
2502 nla_put_labels(skb, RTA_NEWDST, nh->nh_labels,
2503 nh->nh_label))
2504 goto nla_put_failure;
2505
2506 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC &&
2507 nla_put_via(skb, nh->nh_via_table, mpls_nh_via(rt, nh),
2508 nh->nh_via_alen))
2509 goto nla_put_failure;
2510 dev = rtnl_dereference(nh->nh_dev);
2511 if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex))
2512 goto nla_put_failure;
2513
2514 nlmsg_end(skb, nlh);
2515
2516 err = rtnl_unicast(skb, net, portid);
2517 errout:
2518 return err;
2519
2520 nla_put_failure:
2521 nlmsg_cancel(skb, nlh);
2522 err = -EMSGSIZE;
2523 errout_free:
2524 kfree_skb(skb);
2525 return err;
2526 }
2527
resize_platform_label_table(struct net * net,size_t limit)2528 static int resize_platform_label_table(struct net *net, size_t limit)
2529 {
2530 size_t size = sizeof(struct mpls_route *) * limit;
2531 size_t old_limit;
2532 size_t cp_size;
2533 struct mpls_route __rcu **labels = NULL, **old;
2534 struct mpls_route *rt0 = NULL, *rt2 = NULL;
2535 unsigned index;
2536
2537 if (size) {
2538 labels = kvzalloc(size, GFP_KERNEL);
2539 if (!labels)
2540 goto nolabels;
2541 }
2542
2543 /* In case the predefined labels need to be populated */
2544 if (limit > MPLS_LABEL_IPV4NULL) {
2545 struct net_device *lo = net->loopback_dev;
2546 rt0 = mpls_rt_alloc(1, lo->addr_len, 0);
2547 if (IS_ERR(rt0))
2548 goto nort0;
2549 RCU_INIT_POINTER(rt0->rt_nh->nh_dev, lo);
2550 rt0->rt_protocol = RTPROT_KERNEL;
2551 rt0->rt_payload_type = MPT_IPV4;
2552 rt0->rt_ttl_propagate = MPLS_TTL_PROP_DEFAULT;
2553 rt0->rt_nh->nh_via_table = NEIGH_LINK_TABLE;
2554 rt0->rt_nh->nh_via_alen = lo->addr_len;
2555 memcpy(__mpls_nh_via(rt0, rt0->rt_nh), lo->dev_addr,
2556 lo->addr_len);
2557 }
2558 if (limit > MPLS_LABEL_IPV6NULL) {
2559 struct net_device *lo = net->loopback_dev;
2560 rt2 = mpls_rt_alloc(1, lo->addr_len, 0);
2561 if (IS_ERR(rt2))
2562 goto nort2;
2563 RCU_INIT_POINTER(rt2->rt_nh->nh_dev, lo);
2564 rt2->rt_protocol = RTPROT_KERNEL;
2565 rt2->rt_payload_type = MPT_IPV6;
2566 rt2->rt_ttl_propagate = MPLS_TTL_PROP_DEFAULT;
2567 rt2->rt_nh->nh_via_table = NEIGH_LINK_TABLE;
2568 rt2->rt_nh->nh_via_alen = lo->addr_len;
2569 memcpy(__mpls_nh_via(rt2, rt2->rt_nh), lo->dev_addr,
2570 lo->addr_len);
2571 }
2572
2573 rtnl_lock();
2574 /* Remember the original table */
2575 old = rtnl_dereference(net->mpls.platform_label);
2576 old_limit = net->mpls.platform_labels;
2577
2578 /* Free any labels beyond the new table */
2579 for (index = limit; index < old_limit; index++)
2580 mpls_route_update(net, index, NULL, NULL);
2581
2582 /* Copy over the old labels */
2583 cp_size = size;
2584 if (old_limit < limit)
2585 cp_size = old_limit * sizeof(struct mpls_route *);
2586
2587 memcpy(labels, old, cp_size);
2588
2589 /* If needed set the predefined labels */
2590 if ((old_limit <= MPLS_LABEL_IPV6NULL) &&
2591 (limit > MPLS_LABEL_IPV6NULL)) {
2592 RCU_INIT_POINTER(labels[MPLS_LABEL_IPV6NULL], rt2);
2593 rt2 = NULL;
2594 }
2595
2596 if ((old_limit <= MPLS_LABEL_IPV4NULL) &&
2597 (limit > MPLS_LABEL_IPV4NULL)) {
2598 RCU_INIT_POINTER(labels[MPLS_LABEL_IPV4NULL], rt0);
2599 rt0 = NULL;
2600 }
2601
2602 /* Update the global pointers */
2603 net->mpls.platform_labels = limit;
2604 rcu_assign_pointer(net->mpls.platform_label, labels);
2605
2606 rtnl_unlock();
2607
2608 mpls_rt_free(rt2);
2609 mpls_rt_free(rt0);
2610
2611 if (old) {
2612 synchronize_rcu();
2613 kvfree(old);
2614 }
2615 return 0;
2616
2617 nort2:
2618 mpls_rt_free(rt0);
2619 nort0:
2620 kvfree(labels);
2621 nolabels:
2622 return -ENOMEM;
2623 }
2624
mpls_platform_labels(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)2625 static int mpls_platform_labels(struct ctl_table *table, int write,
2626 void *buffer, size_t *lenp, loff_t *ppos)
2627 {
2628 struct net *net = table->data;
2629 int platform_labels = net->mpls.platform_labels;
2630 int ret;
2631 struct ctl_table tmp = {
2632 .procname = table->procname,
2633 .data = &platform_labels,
2634 .maxlen = sizeof(int),
2635 .mode = table->mode,
2636 .extra1 = SYSCTL_ZERO,
2637 .extra2 = &label_limit,
2638 };
2639
2640 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
2641
2642 if (write && ret == 0)
2643 ret = resize_platform_label_table(net, platform_labels);
2644
2645 return ret;
2646 }
2647
2648 #define MPLS_NS_SYSCTL_OFFSET(field) \
2649 (&((struct net *)0)->field)
2650
2651 static const struct ctl_table mpls_table[] = {
2652 {
2653 .procname = "platform_labels",
2654 .data = NULL,
2655 .maxlen = sizeof(int),
2656 .mode = 0644,
2657 .proc_handler = mpls_platform_labels,
2658 },
2659 {
2660 .procname = "ip_ttl_propagate",
2661 .data = MPLS_NS_SYSCTL_OFFSET(mpls.ip_ttl_propagate),
2662 .maxlen = sizeof(int),
2663 .mode = 0644,
2664 .proc_handler = proc_dointvec_minmax,
2665 .extra1 = SYSCTL_ZERO,
2666 .extra2 = SYSCTL_ONE,
2667 },
2668 {
2669 .procname = "default_ttl",
2670 .data = MPLS_NS_SYSCTL_OFFSET(mpls.default_ttl),
2671 .maxlen = sizeof(int),
2672 .mode = 0644,
2673 .proc_handler = proc_dointvec_minmax,
2674 .extra1 = SYSCTL_ONE,
2675 .extra2 = &ttl_max,
2676 },
2677 { }
2678 };
2679
mpls_net_init(struct net * net)2680 static int mpls_net_init(struct net *net)
2681 {
2682 struct ctl_table *table;
2683 int i;
2684
2685 net->mpls.platform_labels = 0;
2686 net->mpls.platform_label = NULL;
2687 net->mpls.ip_ttl_propagate = 1;
2688 net->mpls.default_ttl = 255;
2689
2690 table = kmemdup(mpls_table, sizeof(mpls_table), GFP_KERNEL);
2691 if (table == NULL)
2692 return -ENOMEM;
2693
2694 /* Table data contains only offsets relative to the base of
2695 * the mdev at this point, so make them absolute.
2696 */
2697 for (i = 0; i < ARRAY_SIZE(mpls_table) - 1; i++)
2698 table[i].data = (char *)net + (uintptr_t)table[i].data;
2699
2700 net->mpls.ctl = register_net_sysctl(net, "net/mpls", table);
2701 if (net->mpls.ctl == NULL) {
2702 kfree(table);
2703 return -ENOMEM;
2704 }
2705
2706 return 0;
2707 }
2708
mpls_net_exit(struct net * net)2709 static void mpls_net_exit(struct net *net)
2710 {
2711 struct mpls_route __rcu **platform_label;
2712 size_t platform_labels;
2713 struct ctl_table *table;
2714 unsigned int index;
2715
2716 table = net->mpls.ctl->ctl_table_arg;
2717 unregister_net_sysctl_table(net->mpls.ctl);
2718 kfree(table);
2719
2720 /* An rcu grace period has passed since there was a device in
2721 * the network namespace (and thus the last in flight packet)
2722 * left this network namespace. This is because
2723 * unregister_netdevice_many and netdev_run_todo has completed
2724 * for each network device that was in this network namespace.
2725 *
2726 * As such no additional rcu synchronization is necessary when
2727 * freeing the platform_label table.
2728 */
2729 rtnl_lock();
2730 platform_label = rtnl_dereference(net->mpls.platform_label);
2731 platform_labels = net->mpls.platform_labels;
2732 for (index = 0; index < platform_labels; index++) {
2733 struct mpls_route *rt = rtnl_dereference(platform_label[index]);
2734 RCU_INIT_POINTER(platform_label[index], NULL);
2735 mpls_notify_route(net, index, rt, NULL, NULL);
2736 mpls_rt_free(rt);
2737 }
2738 rtnl_unlock();
2739
2740 kvfree(platform_label);
2741 }
2742
2743 static struct pernet_operations mpls_net_ops = {
2744 .init = mpls_net_init,
2745 .exit = mpls_net_exit,
2746 };
2747
2748 static struct rtnl_af_ops mpls_af_ops __read_mostly = {
2749 .family = AF_MPLS,
2750 .fill_stats_af = mpls_fill_stats_af,
2751 .get_stats_af_size = mpls_get_stats_af_size,
2752 };
2753
mpls_init(void)2754 static int __init mpls_init(void)
2755 {
2756 int err;
2757
2758 BUILD_BUG_ON(sizeof(struct mpls_shim_hdr) != 4);
2759
2760 err = register_pernet_subsys(&mpls_net_ops);
2761 if (err)
2762 goto out;
2763
2764 err = register_netdevice_notifier(&mpls_dev_notifier);
2765 if (err)
2766 goto out_unregister_pernet;
2767
2768 dev_add_pack(&mpls_packet_type);
2769
2770 rtnl_af_register(&mpls_af_ops);
2771
2772 rtnl_register_module(THIS_MODULE, PF_MPLS, RTM_NEWROUTE,
2773 mpls_rtm_newroute, NULL, 0);
2774 rtnl_register_module(THIS_MODULE, PF_MPLS, RTM_DELROUTE,
2775 mpls_rtm_delroute, NULL, 0);
2776 rtnl_register_module(THIS_MODULE, PF_MPLS, RTM_GETROUTE,
2777 mpls_getroute, mpls_dump_routes, 0);
2778 rtnl_register_module(THIS_MODULE, PF_MPLS, RTM_GETNETCONF,
2779 mpls_netconf_get_devconf,
2780 mpls_netconf_dump_devconf, 0);
2781 err = ipgre_tunnel_encap_add_mpls_ops();
2782 if (err)
2783 pr_err("Can't add mpls over gre tunnel ops\n");
2784
2785 err = 0;
2786 out:
2787 return err;
2788
2789 out_unregister_pernet:
2790 unregister_pernet_subsys(&mpls_net_ops);
2791 goto out;
2792 }
2793 module_init(mpls_init);
2794
mpls_exit(void)2795 static void __exit mpls_exit(void)
2796 {
2797 rtnl_unregister_all(PF_MPLS);
2798 rtnl_af_unregister(&mpls_af_ops);
2799 dev_remove_pack(&mpls_packet_type);
2800 unregister_netdevice_notifier(&mpls_dev_notifier);
2801 unregister_pernet_subsys(&mpls_net_ops);
2802 ipgre_tunnel_encap_del_mpls_ops();
2803 }
2804 module_exit(mpls_exit);
2805
2806 MODULE_DESCRIPTION("MultiProtocol Label Switching");
2807 MODULE_LICENSE("GPL v2");
2808 MODULE_ALIAS_NETPROTO(PF_MPLS);
2809