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/gso.h>
16 #include <net/ip.h>
17 #include <net/dst.h>
18 #include <net/sock.h>
19 #include <net/arp.h>
20 #include <net/ip_fib.h>
21 #include <net/netevent.h>
22 #include <net/ip_tunnels.h>
23 #include <net/netns/generic.h>
24 #if IS_ENABLED(CONFIG_IPV6)
25 #include <net/ipv6.h>
26 #endif
27 #include <net/ipv6_stubs.h>
28 #include <net/rtnh.h>
29 #include "internal.h"
30
31 /* max memory we will use for mpls_route */
32 #define MAX_MPLS_ROUTE_MEM 4096
33
34 /* Maximum number of labels to look ahead at when selecting a path of
35 * a multipath route
36 */
37 #define MAX_MP_SELECT_LABELS 4
38
39 #define MPLS_NEIGH_TABLE_UNSPEC (NEIGH_LINK_TABLE + 1)
40
41 static int label_limit = (1 << 20) - 1;
42 static int ttl_max = 255;
43
44 #if IS_ENABLED(CONFIG_NET_IP_TUNNEL)
ipgre_mpls_encap_hlen(struct ip_tunnel_encap * e)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
ipgre_tunnel_encap_add_mpls_ops(void)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
ipgre_tunnel_encap_del_mpls_ops(void)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
ipgre_tunnel_encap_add_mpls_ops(void)64 static int ipgre_tunnel_encap_add_mpls_ops(void)
65 {
66 return 0;
67 }
68
ipgre_tunnel_encap_del_mpls_ops(void)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
mpls_route_input_rcu(struct net * net,unsigned index)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
mpls_output_possible(const struct net_device * dev)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
__mpls_nh_via(struct mpls_route * rt,struct mpls_nh * nh)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
mpls_nh_via(const struct mpls_route * rt,const struct mpls_nh * nh)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
mpls_nh_header_size(const struct mpls_nh * nh)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
mpls_dev_mtu(const struct net_device * dev)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
mpls_pkt_too_big(const struct sk_buff * skb,unsigned int mtu)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_network_len(skb, mtu))
126 return false;
127
128 return true;
129 }
130 EXPORT_SYMBOL_GPL(mpls_pkt_too_big);
131
mpls_stats_inc_outucastpkts(struct net_device * dev,const struct sk_buff * skb)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
mpls_multipath_hash(struct mpls_route * rt,struct sk_buff * skb)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
mpls_get_nexthop(struct mpls_route * rt,u8 index)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 */
mpls_select_multipath(struct mpls_route * rt,struct sk_buff * skb)234 static const 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
mpls_egress(struct net * net,struct mpls_route * rt,struct sk_buff * skb,struct mpls_entry_decoded dec)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
mpls_forward(struct sk_buff * skb,struct net_device * dev,struct packet_type * pt,struct net_device * orig_dev)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 const struct mpls_nh *nh;
348 struct mpls_route *rt;
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 skb_dst_drop(skb);
382
383 /* Read and decode the label */
384 hdr = mpls_hdr(skb);
385 dec = mpls_entry_decode(hdr);
386
387 rt = mpls_route_input_rcu(net, dec.label);
388 if (!rt) {
389 MPLS_INC_STATS(mdev, rx_noroute);
390 goto drop;
391 }
392
393 nh = mpls_select_multipath(rt, skb);
394 if (!nh)
395 goto err;
396
397 /* Pop the label */
398 skb_pull(skb, sizeof(*hdr));
399 skb_reset_network_header(skb);
400
401 skb_orphan(skb);
402
403 if (skb_warn_if_lro(skb))
404 goto err;
405
406 skb_forward_csum(skb);
407
408 /* Verify ttl is valid */
409 if (dec.ttl <= 1)
410 goto err;
411
412 /* Find the output device */
413 out_dev = nh->nh_dev;
414 if (!mpls_output_possible(out_dev))
415 goto tx_err;
416
417 /* Verify the destination can hold the packet */
418 new_header_size = mpls_nh_header_size(nh);
419 mtu = mpls_dev_mtu(out_dev);
420 if (mpls_pkt_too_big(skb, mtu - new_header_size))
421 goto tx_err;
422
423 hh_len = LL_RESERVED_SPACE(out_dev);
424 if (!out_dev->header_ops)
425 hh_len = 0;
426
427 /* Ensure there is enough space for the headers in the skb */
428 if (skb_cow(skb, hh_len + new_header_size))
429 goto tx_err;
430
431 skb->dev = out_dev;
432 skb->protocol = htons(ETH_P_MPLS_UC);
433
434 dec.ttl -= 1;
435 if (unlikely(!new_header_size && dec.bos)) {
436 /* Penultimate hop popping */
437 if (!mpls_egress(dev_net(out_dev), rt, skb, dec))
438 goto err;
439 } else {
440 bool bos;
441 int i;
442 skb_push(skb, new_header_size);
443 skb_reset_network_header(skb);
444 /* Push the new labels */
445 hdr = mpls_hdr(skb);
446 bos = dec.bos;
447 for (i = nh->nh_labels - 1; i >= 0; i--) {
448 hdr[i] = mpls_entry_encode(nh->nh_label[i],
449 dec.ttl, 0, bos);
450 bos = false;
451 }
452 }
453
454 mpls_stats_inc_outucastpkts(out_dev, skb);
455
456 /* If via wasn't specified then send out using device address */
457 if (nh->nh_via_table == MPLS_NEIGH_TABLE_UNSPEC)
458 err = neigh_xmit(NEIGH_LINK_TABLE, out_dev,
459 out_dev->dev_addr, skb);
460 else
461 err = neigh_xmit(nh->nh_via_table, out_dev,
462 mpls_nh_via(rt, nh), skb);
463 if (err)
464 net_dbg_ratelimited("%s: packet transmission failed: %d\n",
465 __func__, err);
466 return 0;
467
468 tx_err:
469 out_mdev = out_dev ? mpls_dev_get(out_dev) : NULL;
470 if (out_mdev)
471 MPLS_INC_STATS(out_mdev, tx_errors);
472 goto drop;
473 err:
474 MPLS_INC_STATS(mdev, rx_errors);
475 drop:
476 kfree_skb(skb);
477 return NET_RX_DROP;
478 }
479
480 static struct packet_type mpls_packet_type __read_mostly = {
481 .type = cpu_to_be16(ETH_P_MPLS_UC),
482 .func = mpls_forward,
483 };
484
485 static const struct nla_policy rtm_mpls_policy[RTA_MAX+1] = {
486 [RTA_DST] = { .type = NLA_U32 },
487 [RTA_OIF] = { .type = NLA_U32 },
488 [RTA_TTL_PROPAGATE] = { .type = NLA_U8 },
489 };
490
491 struct mpls_route_config {
492 u32 rc_protocol;
493 u32 rc_ifindex;
494 u8 rc_via_table;
495 u8 rc_via_alen;
496 u8 rc_via[MAX_VIA_ALEN];
497 u32 rc_label;
498 u8 rc_ttl_propagate;
499 u8 rc_output_labels;
500 u32 rc_output_label[MAX_NEW_LABELS];
501 u32 rc_nlflags;
502 enum mpls_payload_type rc_payload_type;
503 struct nl_info rc_nlinfo;
504 struct rtnexthop *rc_mp;
505 int rc_mp_len;
506 };
507
508 /* all nexthops within a route have the same size based on max
509 * number of labels and max via length for a hop
510 */
mpls_rt_alloc(u8 num_nh,u8 max_alen,u8 max_labels)511 static struct mpls_route *mpls_rt_alloc(u8 num_nh, u8 max_alen, u8 max_labels)
512 {
513 u8 nh_size = MPLS_NH_SIZE(max_labels, max_alen);
514 struct mpls_route *rt;
515 size_t size;
516
517 size = sizeof(*rt) + num_nh * nh_size;
518 if (size > MAX_MPLS_ROUTE_MEM)
519 return ERR_PTR(-EINVAL);
520
521 rt = kzalloc(size, GFP_KERNEL);
522 if (!rt)
523 return ERR_PTR(-ENOMEM);
524
525 rt->rt_nhn = num_nh;
526 rt->rt_nhn_alive = num_nh;
527 rt->rt_nh_size = nh_size;
528 rt->rt_via_offset = MPLS_NH_VIA_OFF(max_labels);
529
530 return rt;
531 }
532
mpls_rt_free(struct mpls_route * rt)533 static void mpls_rt_free(struct mpls_route *rt)
534 {
535 if (rt)
536 kfree_rcu(rt, rt_rcu);
537 }
538
mpls_notify_route(struct net * net,unsigned index,struct mpls_route * old,struct mpls_route * new,const struct nl_info * info)539 static void mpls_notify_route(struct net *net, unsigned index,
540 struct mpls_route *old, struct mpls_route *new,
541 const struct nl_info *info)
542 {
543 struct nlmsghdr *nlh = info ? info->nlh : NULL;
544 unsigned portid = info ? info->portid : 0;
545 int event = new ? RTM_NEWROUTE : RTM_DELROUTE;
546 struct mpls_route *rt = new ? new : old;
547 unsigned nlm_flags = (old && new) ? NLM_F_REPLACE : 0;
548 /* Ignore reserved labels for now */
549 if (rt && (index >= MPLS_LABEL_FIRST_UNRESERVED))
550 rtmsg_lfib(event, index, rt, nlh, net, portid, nlm_flags);
551 }
552
mpls_route_update(struct net * net,unsigned index,struct mpls_route * new,const struct nl_info * info)553 static void mpls_route_update(struct net *net, unsigned index,
554 struct mpls_route *new,
555 const struct nl_info *info)
556 {
557 struct mpls_route __rcu **platform_label;
558 struct mpls_route *rt;
559
560 ASSERT_RTNL();
561
562 platform_label = rtnl_dereference(net->mpls.platform_label);
563 rt = rtnl_dereference(platform_label[index]);
564 rcu_assign_pointer(platform_label[index], new);
565
566 mpls_notify_route(net, index, rt, new, info);
567
568 /* If we removed a route free it now */
569 mpls_rt_free(rt);
570 }
571
find_free_label(struct net * net)572 static unsigned find_free_label(struct net *net)
573 {
574 struct mpls_route __rcu **platform_label;
575 size_t platform_labels;
576 unsigned index;
577
578 platform_label = rtnl_dereference(net->mpls.platform_label);
579 platform_labels = net->mpls.platform_labels;
580 for (index = MPLS_LABEL_FIRST_UNRESERVED; index < platform_labels;
581 index++) {
582 if (!rtnl_dereference(platform_label[index]))
583 return index;
584 }
585 return LABEL_NOT_SPECIFIED;
586 }
587
588 #if IS_ENABLED(CONFIG_INET)
inet_fib_lookup_dev(struct net * net,const void * addr)589 static struct net_device *inet_fib_lookup_dev(struct net *net,
590 const void *addr)
591 {
592 struct net_device *dev;
593 struct rtable *rt;
594 struct in_addr daddr;
595
596 memcpy(&daddr, addr, sizeof(struct in_addr));
597 rt = ip_route_output(net, daddr.s_addr, 0, 0, 0);
598 if (IS_ERR(rt))
599 return ERR_CAST(rt);
600
601 dev = rt->dst.dev;
602 dev_hold(dev);
603
604 ip_rt_put(rt);
605
606 return dev;
607 }
608 #else
inet_fib_lookup_dev(struct net * net,const void * addr)609 static struct net_device *inet_fib_lookup_dev(struct net *net,
610 const void *addr)
611 {
612 return ERR_PTR(-EAFNOSUPPORT);
613 }
614 #endif
615
616 #if IS_ENABLED(CONFIG_IPV6)
inet6_fib_lookup_dev(struct net * net,const void * addr)617 static struct net_device *inet6_fib_lookup_dev(struct net *net,
618 const void *addr)
619 {
620 struct net_device *dev;
621 struct dst_entry *dst;
622 struct flowi6 fl6;
623
624 if (!ipv6_stub)
625 return ERR_PTR(-EAFNOSUPPORT);
626
627 memset(&fl6, 0, sizeof(fl6));
628 memcpy(&fl6.daddr, addr, sizeof(struct in6_addr));
629 dst = ipv6_stub->ipv6_dst_lookup_flow(net, NULL, &fl6, NULL);
630 if (IS_ERR(dst))
631 return ERR_CAST(dst);
632
633 dev = dst->dev;
634 dev_hold(dev);
635 dst_release(dst);
636
637 return dev;
638 }
639 #else
inet6_fib_lookup_dev(struct net * net,const void * addr)640 static struct net_device *inet6_fib_lookup_dev(struct net *net,
641 const void *addr)
642 {
643 return ERR_PTR(-EAFNOSUPPORT);
644 }
645 #endif
646
find_outdev(struct net * net,struct mpls_route * rt,struct mpls_nh * nh,int oif)647 static struct net_device *find_outdev(struct net *net,
648 struct mpls_route *rt,
649 struct mpls_nh *nh, int oif)
650 {
651 struct net_device *dev = NULL;
652
653 if (!oif) {
654 switch (nh->nh_via_table) {
655 case NEIGH_ARP_TABLE:
656 dev = inet_fib_lookup_dev(net, mpls_nh_via(rt, nh));
657 break;
658 case NEIGH_ND_TABLE:
659 dev = inet6_fib_lookup_dev(net, mpls_nh_via(rt, nh));
660 break;
661 case NEIGH_LINK_TABLE:
662 break;
663 }
664 } else {
665 dev = dev_get_by_index(net, oif);
666 }
667
668 if (!dev)
669 return ERR_PTR(-ENODEV);
670
671 if (IS_ERR(dev))
672 return dev;
673
674 /* The caller is holding rtnl anyways, so release the dev reference */
675 dev_put(dev);
676
677 return dev;
678 }
679
mpls_nh_assign_dev(struct net * net,struct mpls_route * rt,struct mpls_nh * nh,int oif)680 static int mpls_nh_assign_dev(struct net *net, struct mpls_route *rt,
681 struct mpls_nh *nh, int oif)
682 {
683 struct net_device *dev = NULL;
684 int err = -ENODEV;
685
686 dev = find_outdev(net, rt, nh, oif);
687 if (IS_ERR(dev)) {
688 err = PTR_ERR(dev);
689 dev = NULL;
690 goto errout;
691 }
692
693 /* Ensure this is a supported device */
694 err = -EINVAL;
695 if (!mpls_dev_get(dev))
696 goto errout;
697
698 if ((nh->nh_via_table == NEIGH_LINK_TABLE) &&
699 (dev->addr_len != nh->nh_via_alen))
700 goto errout;
701
702 nh->nh_dev = dev;
703
704 if (!(dev->flags & IFF_UP)) {
705 nh->nh_flags |= RTNH_F_DEAD;
706 } else {
707 unsigned int flags;
708
709 flags = dev_get_flags(dev);
710 if (!(flags & (IFF_RUNNING | IFF_LOWER_UP)))
711 nh->nh_flags |= RTNH_F_LINKDOWN;
712 }
713
714 return 0;
715
716 errout:
717 return err;
718 }
719
nla_get_via(const struct nlattr * nla,u8 * via_alen,u8 * via_table,u8 via_addr[],struct netlink_ext_ack * extack)720 static int nla_get_via(const struct nlattr *nla, u8 *via_alen, u8 *via_table,
721 u8 via_addr[], struct netlink_ext_ack *extack)
722 {
723 struct rtvia *via = nla_data(nla);
724 int err = -EINVAL;
725 int alen;
726
727 if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) {
728 NL_SET_ERR_MSG_ATTR(extack, nla,
729 "Invalid attribute length for RTA_VIA");
730 goto errout;
731 }
732 alen = nla_len(nla) -
733 offsetof(struct rtvia, rtvia_addr);
734 if (alen > MAX_VIA_ALEN) {
735 NL_SET_ERR_MSG_ATTR(extack, nla,
736 "Invalid address length for RTA_VIA");
737 goto errout;
738 }
739
740 /* Validate the address family */
741 switch (via->rtvia_family) {
742 case AF_PACKET:
743 *via_table = NEIGH_LINK_TABLE;
744 break;
745 case AF_INET:
746 *via_table = NEIGH_ARP_TABLE;
747 if (alen != 4)
748 goto errout;
749 break;
750 case AF_INET6:
751 *via_table = NEIGH_ND_TABLE;
752 if (alen != 16)
753 goto errout;
754 break;
755 default:
756 /* Unsupported address family */
757 goto errout;
758 }
759
760 memcpy(via_addr, via->rtvia_addr, alen);
761 *via_alen = alen;
762 err = 0;
763
764 errout:
765 return err;
766 }
767
mpls_nh_build_from_cfg(struct mpls_route_config * cfg,struct mpls_route * rt)768 static int mpls_nh_build_from_cfg(struct mpls_route_config *cfg,
769 struct mpls_route *rt)
770 {
771 struct net *net = cfg->rc_nlinfo.nl_net;
772 struct mpls_nh *nh = rt->rt_nh;
773 int err;
774 int i;
775
776 if (!nh)
777 return -ENOMEM;
778
779 nh->nh_labels = cfg->rc_output_labels;
780 for (i = 0; i < nh->nh_labels; i++)
781 nh->nh_label[i] = cfg->rc_output_label[i];
782
783 nh->nh_via_table = cfg->rc_via_table;
784 memcpy(__mpls_nh_via(rt, nh), cfg->rc_via, cfg->rc_via_alen);
785 nh->nh_via_alen = cfg->rc_via_alen;
786
787 err = mpls_nh_assign_dev(net, rt, nh, cfg->rc_ifindex);
788 if (err)
789 goto errout;
790
791 if (nh->nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN))
792 rt->rt_nhn_alive--;
793
794 return 0;
795
796 errout:
797 return err;
798 }
799
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)800 static int mpls_nh_build(struct net *net, struct mpls_route *rt,
801 struct mpls_nh *nh, int oif, struct nlattr *via,
802 struct nlattr *newdst, u8 max_labels,
803 struct netlink_ext_ack *extack)
804 {
805 int err = -ENOMEM;
806
807 if (!nh)
808 goto errout;
809
810 if (newdst) {
811 err = nla_get_labels(newdst, max_labels, &nh->nh_labels,
812 nh->nh_label, extack);
813 if (err)
814 goto errout;
815 }
816
817 if (via) {
818 err = nla_get_via(via, &nh->nh_via_alen, &nh->nh_via_table,
819 __mpls_nh_via(rt, nh), extack);
820 if (err)
821 goto errout;
822 } else {
823 nh->nh_via_table = MPLS_NEIGH_TABLE_UNSPEC;
824 }
825
826 err = mpls_nh_assign_dev(net, rt, nh, oif);
827 if (err)
828 goto errout;
829
830 return 0;
831
832 errout:
833 return err;
834 }
835
mpls_count_nexthops(struct rtnexthop * rtnh,int len,u8 cfg_via_alen,u8 * max_via_alen,u8 * max_labels)836 static u8 mpls_count_nexthops(struct rtnexthop *rtnh, int len,
837 u8 cfg_via_alen, u8 *max_via_alen,
838 u8 *max_labels)
839 {
840 int remaining = len;
841 u8 nhs = 0;
842
843 *max_via_alen = 0;
844 *max_labels = 0;
845
846 while (rtnh_ok(rtnh, remaining)) {
847 struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
848 int attrlen;
849 u8 n_labels = 0;
850
851 attrlen = rtnh_attrlen(rtnh);
852 nla = nla_find(attrs, attrlen, RTA_VIA);
853 if (nla && nla_len(nla) >=
854 offsetof(struct rtvia, rtvia_addr)) {
855 int via_alen = nla_len(nla) -
856 offsetof(struct rtvia, rtvia_addr);
857
858 if (via_alen <= MAX_VIA_ALEN)
859 *max_via_alen = max_t(u16, *max_via_alen,
860 via_alen);
861 }
862
863 nla = nla_find(attrs, attrlen, RTA_NEWDST);
864 if (nla &&
865 nla_get_labels(nla, MAX_NEW_LABELS, &n_labels,
866 NULL, NULL) != 0)
867 return 0;
868
869 *max_labels = max_t(u8, *max_labels, n_labels);
870
871 /* number of nexthops is tracked by a u8.
872 * Check for overflow.
873 */
874 if (nhs == 255)
875 return 0;
876 nhs++;
877
878 rtnh = rtnh_next(rtnh, &remaining);
879 }
880
881 /* leftover implies invalid nexthop configuration, discard it */
882 return remaining > 0 ? 0 : nhs;
883 }
884
mpls_nh_build_multi(struct mpls_route_config * cfg,struct mpls_route * rt,u8 max_labels,struct netlink_ext_ack * extack)885 static int mpls_nh_build_multi(struct mpls_route_config *cfg,
886 struct mpls_route *rt, u8 max_labels,
887 struct netlink_ext_ack *extack)
888 {
889 struct rtnexthop *rtnh = cfg->rc_mp;
890 struct nlattr *nla_via, *nla_newdst;
891 int remaining = cfg->rc_mp_len;
892 int err = 0;
893 u8 nhs = 0;
894
895 change_nexthops(rt) {
896 int attrlen;
897
898 nla_via = NULL;
899 nla_newdst = NULL;
900
901 err = -EINVAL;
902 if (!rtnh_ok(rtnh, remaining))
903 goto errout;
904
905 /* neither weighted multipath nor any flags
906 * are supported
907 */
908 if (rtnh->rtnh_hops || rtnh->rtnh_flags)
909 goto errout;
910
911 attrlen = rtnh_attrlen(rtnh);
912 if (attrlen > 0) {
913 struct nlattr *attrs = rtnh_attrs(rtnh);
914
915 nla_via = nla_find(attrs, attrlen, RTA_VIA);
916 nla_newdst = nla_find(attrs, attrlen, RTA_NEWDST);
917 }
918
919 err = mpls_nh_build(cfg->rc_nlinfo.nl_net, rt, nh,
920 rtnh->rtnh_ifindex, nla_via, nla_newdst,
921 max_labels, extack);
922 if (err)
923 goto errout;
924
925 if (nh->nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN))
926 rt->rt_nhn_alive--;
927
928 rtnh = rtnh_next(rtnh, &remaining);
929 nhs++;
930 } endfor_nexthops(rt);
931
932 rt->rt_nhn = nhs;
933
934 return 0;
935
936 errout:
937 return err;
938 }
939
mpls_label_ok(struct net * net,unsigned int * index,struct netlink_ext_ack * extack)940 static bool mpls_label_ok(struct net *net, unsigned int *index,
941 struct netlink_ext_ack *extack)
942 {
943 bool is_ok = true;
944
945 /* Reserved labels may not be set */
946 if (*index < MPLS_LABEL_FIRST_UNRESERVED) {
947 NL_SET_ERR_MSG(extack,
948 "Invalid label - must be MPLS_LABEL_FIRST_UNRESERVED or higher");
949 is_ok = false;
950 }
951
952 /* The full 20 bit range may not be supported. */
953 if (is_ok && *index >= net->mpls.platform_labels) {
954 NL_SET_ERR_MSG(extack,
955 "Label >= configured maximum in platform_labels");
956 is_ok = false;
957 }
958
959 *index = array_index_nospec(*index, net->mpls.platform_labels);
960 return is_ok;
961 }
962
mpls_route_add(struct mpls_route_config * cfg,struct netlink_ext_ack * extack)963 static int mpls_route_add(struct mpls_route_config *cfg,
964 struct netlink_ext_ack *extack)
965 {
966 struct mpls_route __rcu **platform_label;
967 struct net *net = cfg->rc_nlinfo.nl_net;
968 struct mpls_route *rt, *old;
969 int err = -EINVAL;
970 u8 max_via_alen;
971 unsigned index;
972 u8 max_labels;
973 u8 nhs;
974
975 index = cfg->rc_label;
976
977 /* If a label was not specified during insert pick one */
978 if ((index == LABEL_NOT_SPECIFIED) &&
979 (cfg->rc_nlflags & NLM_F_CREATE)) {
980 index = find_free_label(net);
981 }
982
983 if (!mpls_label_ok(net, &index, extack))
984 goto errout;
985
986 /* Append makes no sense with mpls */
987 err = -EOPNOTSUPP;
988 if (cfg->rc_nlflags & NLM_F_APPEND) {
989 NL_SET_ERR_MSG(extack, "MPLS does not support route append");
990 goto errout;
991 }
992
993 err = -EEXIST;
994 platform_label = rtnl_dereference(net->mpls.platform_label);
995 old = rtnl_dereference(platform_label[index]);
996 if ((cfg->rc_nlflags & NLM_F_EXCL) && old)
997 goto errout;
998
999 err = -EEXIST;
1000 if (!(cfg->rc_nlflags & NLM_F_REPLACE) && old)
1001 goto errout;
1002
1003 err = -ENOENT;
1004 if (!(cfg->rc_nlflags & NLM_F_CREATE) && !old)
1005 goto errout;
1006
1007 err = -EINVAL;
1008 if (cfg->rc_mp) {
1009 nhs = mpls_count_nexthops(cfg->rc_mp, cfg->rc_mp_len,
1010 cfg->rc_via_alen, &max_via_alen,
1011 &max_labels);
1012 } else {
1013 max_via_alen = cfg->rc_via_alen;
1014 max_labels = cfg->rc_output_labels;
1015 nhs = 1;
1016 }
1017
1018 if (nhs == 0) {
1019 NL_SET_ERR_MSG(extack, "Route does not contain a nexthop");
1020 goto errout;
1021 }
1022
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
mpls_route_del(struct mpls_route_config * cfg,struct netlink_ext_ack * extack)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
mpls_get_stats(struct mpls_dev * mdev,struct mpls_link_stats * stats)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
mpls_fill_stats_af(struct sk_buff * skb,const struct net_device * dev)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
mpls_get_stats_af_size(const struct net_device * dev)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
mpls_netconf_fill_devconf(struct sk_buff * skb,struct mpls_dev * mdev,u32 portid,u32 seq,int event,unsigned int flags,int type)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 READ_ONCE(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
mpls_netconf_msgsize_devconf(int type)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
mpls_netconf_notify_devconf(struct net * net,int event,int type,struct mpls_dev * mdev)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
mpls_netconf_valid_get_req(struct sk_buff * skb,const struct nlmsghdr * nlh,struct nlattr ** tb,struct netlink_ext_ack * extack)1212 static int mpls_netconf_valid_get_req(struct sk_buff *skb,
1213 const struct nlmsghdr *nlh,
1214 struct nlattr **tb,
1215 struct netlink_ext_ack *extack)
1216 {
1217 int i, err;
1218
1219 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(struct netconfmsg))) {
1220 NL_SET_ERR_MSG_MOD(extack,
1221 "Invalid header for netconf get request");
1222 return -EINVAL;
1223 }
1224
1225 if (!netlink_strict_get_check(skb))
1226 return nlmsg_parse_deprecated(nlh, sizeof(struct netconfmsg),
1227 tb, NETCONFA_MAX,
1228 devconf_mpls_policy, extack);
1229
1230 err = nlmsg_parse_deprecated_strict(nlh, sizeof(struct netconfmsg),
1231 tb, NETCONFA_MAX,
1232 devconf_mpls_policy, extack);
1233 if (err)
1234 return err;
1235
1236 for (i = 0; i <= NETCONFA_MAX; i++) {
1237 if (!tb[i])
1238 continue;
1239
1240 switch (i) {
1241 case NETCONFA_IFINDEX:
1242 break;
1243 default:
1244 NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in netconf get request");
1245 return -EINVAL;
1246 }
1247 }
1248
1249 return 0;
1250 }
1251
mpls_netconf_get_devconf(struct sk_buff * in_skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack)1252 static int mpls_netconf_get_devconf(struct sk_buff *in_skb,
1253 struct nlmsghdr *nlh,
1254 struct netlink_ext_ack *extack)
1255 {
1256 struct net *net = sock_net(in_skb->sk);
1257 struct nlattr *tb[NETCONFA_MAX + 1];
1258 struct net_device *dev;
1259 struct mpls_dev *mdev;
1260 struct sk_buff *skb;
1261 int ifindex;
1262 int err;
1263
1264 err = mpls_netconf_valid_get_req(in_skb, nlh, tb, extack);
1265 if (err < 0)
1266 goto errout;
1267
1268 err = -EINVAL;
1269 if (!tb[NETCONFA_IFINDEX])
1270 goto errout;
1271
1272 ifindex = nla_get_s32(tb[NETCONFA_IFINDEX]);
1273 dev = __dev_get_by_index(net, ifindex);
1274 if (!dev)
1275 goto errout;
1276
1277 mdev = mpls_dev_get(dev);
1278 if (!mdev)
1279 goto errout;
1280
1281 err = -ENOBUFS;
1282 skb = nlmsg_new(mpls_netconf_msgsize_devconf(NETCONFA_ALL), GFP_KERNEL);
1283 if (!skb)
1284 goto errout;
1285
1286 err = mpls_netconf_fill_devconf(skb, mdev,
1287 NETLINK_CB(in_skb).portid,
1288 nlh->nlmsg_seq, RTM_NEWNETCONF, 0,
1289 NETCONFA_ALL);
1290 if (err < 0) {
1291 /* -EMSGSIZE implies BUG in mpls_netconf_msgsize_devconf() */
1292 WARN_ON(err == -EMSGSIZE);
1293 kfree_skb(skb);
1294 goto errout;
1295 }
1296 err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
1297 errout:
1298 return err;
1299 }
1300
mpls_netconf_dump_devconf(struct sk_buff * skb,struct netlink_callback * cb)1301 static int mpls_netconf_dump_devconf(struct sk_buff *skb,
1302 struct netlink_callback *cb)
1303 {
1304 const struct nlmsghdr *nlh = cb->nlh;
1305 struct net *net = sock_net(skb->sk);
1306 struct {
1307 unsigned long ifindex;
1308 } *ctx = (void *)cb->ctx;
1309 struct net_device *dev;
1310 struct mpls_dev *mdev;
1311 int err = 0;
1312
1313 if (cb->strict_check) {
1314 struct netlink_ext_ack *extack = cb->extack;
1315 struct netconfmsg *ncm;
1316
1317 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ncm))) {
1318 NL_SET_ERR_MSG_MOD(extack, "Invalid header for netconf dump request");
1319 return -EINVAL;
1320 }
1321
1322 if (nlmsg_attrlen(nlh, sizeof(*ncm))) {
1323 NL_SET_ERR_MSG_MOD(extack, "Invalid data after header in netconf dump request");
1324 return -EINVAL;
1325 }
1326 }
1327
1328 rcu_read_lock();
1329 for_each_netdev_dump(net, dev, ctx->ifindex) {
1330 mdev = mpls_dev_get(dev);
1331 if (!mdev)
1332 continue;
1333 err = mpls_netconf_fill_devconf(skb, mdev,
1334 NETLINK_CB(cb->skb).portid,
1335 nlh->nlmsg_seq,
1336 RTM_NEWNETCONF,
1337 NLM_F_MULTI,
1338 NETCONFA_ALL);
1339 if (err < 0)
1340 break;
1341 }
1342 rcu_read_unlock();
1343
1344 return err;
1345 }
1346
1347 #define MPLS_PERDEV_SYSCTL_OFFSET(field) \
1348 (&((struct mpls_dev *)0)->field)
1349
mpls_conf_proc(struct ctl_table * ctl,int write,void * buffer,size_t * lenp,loff_t * ppos)1350 static int mpls_conf_proc(struct ctl_table *ctl, int write,
1351 void *buffer, size_t *lenp, loff_t *ppos)
1352 {
1353 int oval = *(int *)ctl->data;
1354 int ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
1355
1356 if (write) {
1357 struct mpls_dev *mdev = ctl->extra1;
1358 int i = (int *)ctl->data - (int *)mdev;
1359 struct net *net = ctl->extra2;
1360 int val = *(int *)ctl->data;
1361
1362 if (i == offsetof(struct mpls_dev, input_enabled) &&
1363 val != oval) {
1364 mpls_netconf_notify_devconf(net, RTM_NEWNETCONF,
1365 NETCONFA_INPUT, mdev);
1366 }
1367 }
1368
1369 return ret;
1370 }
1371
1372 static const struct ctl_table mpls_dev_table[] = {
1373 {
1374 .procname = "input",
1375 .maxlen = sizeof(int),
1376 .mode = 0644,
1377 .proc_handler = mpls_conf_proc,
1378 .data = MPLS_PERDEV_SYSCTL_OFFSET(input_enabled),
1379 },
1380 { }
1381 };
1382
mpls_dev_sysctl_register(struct net_device * dev,struct mpls_dev * mdev)1383 static int mpls_dev_sysctl_register(struct net_device *dev,
1384 struct mpls_dev *mdev)
1385 {
1386 char path[sizeof("net/mpls/conf/") + IFNAMSIZ];
1387 struct net *net = dev_net(dev);
1388 struct ctl_table *table;
1389 int i;
1390
1391 table = kmemdup(&mpls_dev_table, sizeof(mpls_dev_table), GFP_KERNEL);
1392 if (!table)
1393 goto out;
1394
1395 /* Table data contains only offsets relative to the base of
1396 * the mdev at this point, so make them absolute.
1397 */
1398 for (i = 0; i < ARRAY_SIZE(mpls_dev_table); i++) {
1399 table[i].data = (char *)mdev + (uintptr_t)table[i].data;
1400 table[i].extra1 = mdev;
1401 table[i].extra2 = net;
1402 }
1403
1404 snprintf(path, sizeof(path), "net/mpls/conf/%s", dev->name);
1405
1406 mdev->sysctl = register_net_sysctl_sz(net, path, table,
1407 ARRAY_SIZE(mpls_dev_table));
1408 if (!mdev->sysctl)
1409 goto free;
1410
1411 mpls_netconf_notify_devconf(net, RTM_NEWNETCONF, NETCONFA_ALL, mdev);
1412 return 0;
1413
1414 free:
1415 kfree(table);
1416 out:
1417 mdev->sysctl = NULL;
1418 return -ENOBUFS;
1419 }
1420
mpls_dev_sysctl_unregister(struct net_device * dev,struct mpls_dev * mdev)1421 static void mpls_dev_sysctl_unregister(struct net_device *dev,
1422 struct mpls_dev *mdev)
1423 {
1424 struct net *net = dev_net(dev);
1425 struct ctl_table *table;
1426
1427 if (!mdev->sysctl)
1428 return;
1429
1430 table = mdev->sysctl->ctl_table_arg;
1431 unregister_net_sysctl_table(mdev->sysctl);
1432 kfree(table);
1433
1434 mpls_netconf_notify_devconf(net, RTM_DELNETCONF, 0, mdev);
1435 }
1436
mpls_add_dev(struct net_device * dev)1437 static struct mpls_dev *mpls_add_dev(struct net_device *dev)
1438 {
1439 struct mpls_dev *mdev;
1440 int err = -ENOMEM;
1441 int i;
1442
1443 ASSERT_RTNL();
1444
1445 mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
1446 if (!mdev)
1447 return ERR_PTR(err);
1448
1449 mdev->stats = alloc_percpu(struct mpls_pcpu_stats);
1450 if (!mdev->stats)
1451 goto free;
1452
1453 for_each_possible_cpu(i) {
1454 struct mpls_pcpu_stats *mpls_stats;
1455
1456 mpls_stats = per_cpu_ptr(mdev->stats, i);
1457 u64_stats_init(&mpls_stats->syncp);
1458 }
1459
1460 mdev->dev = dev;
1461
1462 err = mpls_dev_sysctl_register(dev, mdev);
1463 if (err)
1464 goto free;
1465
1466 rcu_assign_pointer(dev->mpls_ptr, mdev);
1467
1468 return mdev;
1469
1470 free:
1471 free_percpu(mdev->stats);
1472 kfree(mdev);
1473 return ERR_PTR(err);
1474 }
1475
mpls_dev_destroy_rcu(struct rcu_head * head)1476 static void mpls_dev_destroy_rcu(struct rcu_head *head)
1477 {
1478 struct mpls_dev *mdev = container_of(head, struct mpls_dev, rcu);
1479
1480 free_percpu(mdev->stats);
1481 kfree(mdev);
1482 }
1483
mpls_ifdown(struct net_device * dev,int event)1484 static int mpls_ifdown(struct net_device *dev, int event)
1485 {
1486 struct mpls_route __rcu **platform_label;
1487 struct net *net = dev_net(dev);
1488 unsigned index;
1489
1490 platform_label = rtnl_dereference(net->mpls.platform_label);
1491 for (index = 0; index < net->mpls.platform_labels; index++) {
1492 struct mpls_route *rt = rtnl_dereference(platform_label[index]);
1493 bool nh_del = false;
1494 u8 alive = 0;
1495
1496 if (!rt)
1497 continue;
1498
1499 if (event == NETDEV_UNREGISTER) {
1500 u8 deleted = 0;
1501
1502 for_nexthops(rt) {
1503 if (!nh->nh_dev || nh->nh_dev == dev)
1504 deleted++;
1505 if (nh->nh_dev == dev)
1506 nh_del = true;
1507 } endfor_nexthops(rt);
1508
1509 /* if there are no more nexthops, delete the route */
1510 if (deleted == rt->rt_nhn) {
1511 mpls_route_update(net, index, NULL, NULL);
1512 continue;
1513 }
1514
1515 if (nh_del) {
1516 size_t size = sizeof(*rt) + rt->rt_nhn *
1517 rt->rt_nh_size;
1518 struct mpls_route *orig = rt;
1519
1520 rt = kmemdup(orig, size, GFP_KERNEL);
1521 if (!rt)
1522 return -ENOMEM;
1523 }
1524 }
1525
1526 change_nexthops(rt) {
1527 unsigned int nh_flags = nh->nh_flags;
1528
1529 if (nh->nh_dev != dev)
1530 goto next;
1531
1532 switch (event) {
1533 case NETDEV_DOWN:
1534 case NETDEV_UNREGISTER:
1535 nh_flags |= RTNH_F_DEAD;
1536 fallthrough;
1537 case NETDEV_CHANGE:
1538 nh_flags |= RTNH_F_LINKDOWN;
1539 break;
1540 }
1541 if (event == NETDEV_UNREGISTER)
1542 nh->nh_dev = NULL;
1543
1544 if (nh->nh_flags != nh_flags)
1545 WRITE_ONCE(nh->nh_flags, nh_flags);
1546 next:
1547 if (!(nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)))
1548 alive++;
1549 } endfor_nexthops(rt);
1550
1551 WRITE_ONCE(rt->rt_nhn_alive, alive);
1552
1553 if (nh_del)
1554 mpls_route_update(net, index, rt, NULL);
1555 }
1556
1557 return 0;
1558 }
1559
mpls_ifup(struct net_device * dev,unsigned int flags)1560 static void mpls_ifup(struct net_device *dev, unsigned int flags)
1561 {
1562 struct mpls_route __rcu **platform_label;
1563 struct net *net = dev_net(dev);
1564 unsigned index;
1565 u8 alive;
1566
1567 platform_label = rtnl_dereference(net->mpls.platform_label);
1568 for (index = 0; index < net->mpls.platform_labels; index++) {
1569 struct mpls_route *rt = rtnl_dereference(platform_label[index]);
1570
1571 if (!rt)
1572 continue;
1573
1574 alive = 0;
1575 change_nexthops(rt) {
1576 unsigned int nh_flags = nh->nh_flags;
1577
1578 if (!(nh_flags & flags)) {
1579 alive++;
1580 continue;
1581 }
1582 if (nh->nh_dev != dev)
1583 continue;
1584 alive++;
1585 nh_flags &= ~flags;
1586 WRITE_ONCE(nh->nh_flags, nh_flags);
1587 } endfor_nexthops(rt);
1588
1589 WRITE_ONCE(rt->rt_nhn_alive, alive);
1590 }
1591 }
1592
mpls_dev_notify(struct notifier_block * this,unsigned long event,void * ptr)1593 static int mpls_dev_notify(struct notifier_block *this, unsigned long event,
1594 void *ptr)
1595 {
1596 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1597 struct mpls_dev *mdev;
1598 unsigned int flags;
1599 int err;
1600
1601 if (event == NETDEV_REGISTER) {
1602 mdev = mpls_add_dev(dev);
1603 if (IS_ERR(mdev))
1604 return notifier_from_errno(PTR_ERR(mdev));
1605
1606 return NOTIFY_OK;
1607 }
1608
1609 mdev = mpls_dev_get(dev);
1610 if (!mdev)
1611 return NOTIFY_OK;
1612
1613 switch (event) {
1614
1615 case NETDEV_DOWN:
1616 err = mpls_ifdown(dev, event);
1617 if (err)
1618 return notifier_from_errno(err);
1619 break;
1620 case NETDEV_UP:
1621 flags = dev_get_flags(dev);
1622 if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1623 mpls_ifup(dev, RTNH_F_DEAD | RTNH_F_LINKDOWN);
1624 else
1625 mpls_ifup(dev, RTNH_F_DEAD);
1626 break;
1627 case NETDEV_CHANGE:
1628 flags = dev_get_flags(dev);
1629 if (flags & (IFF_RUNNING | IFF_LOWER_UP)) {
1630 mpls_ifup(dev, RTNH_F_DEAD | RTNH_F_LINKDOWN);
1631 } else {
1632 err = mpls_ifdown(dev, event);
1633 if (err)
1634 return notifier_from_errno(err);
1635 }
1636 break;
1637 case NETDEV_UNREGISTER:
1638 err = mpls_ifdown(dev, event);
1639 if (err)
1640 return notifier_from_errno(err);
1641 mdev = mpls_dev_get(dev);
1642 if (mdev) {
1643 mpls_dev_sysctl_unregister(dev, mdev);
1644 RCU_INIT_POINTER(dev->mpls_ptr, NULL);
1645 call_rcu(&mdev->rcu, mpls_dev_destroy_rcu);
1646 }
1647 break;
1648 case NETDEV_CHANGENAME:
1649 mdev = mpls_dev_get(dev);
1650 if (mdev) {
1651 mpls_dev_sysctl_unregister(dev, mdev);
1652 err = mpls_dev_sysctl_register(dev, mdev);
1653 if (err)
1654 return notifier_from_errno(err);
1655 }
1656 break;
1657 }
1658 return NOTIFY_OK;
1659 }
1660
1661 static struct notifier_block mpls_dev_notifier = {
1662 .notifier_call = mpls_dev_notify,
1663 };
1664
nla_put_via(struct sk_buff * skb,u8 table,const void * addr,int alen)1665 static int nla_put_via(struct sk_buff *skb,
1666 u8 table, const void *addr, int alen)
1667 {
1668 static const int table_to_family[NEIGH_NR_TABLES + 1] = {
1669 AF_INET, AF_INET6, AF_DECnet, AF_PACKET,
1670 };
1671 struct nlattr *nla;
1672 struct rtvia *via;
1673 int family = AF_UNSPEC;
1674
1675 nla = nla_reserve(skb, RTA_VIA, alen + 2);
1676 if (!nla)
1677 return -EMSGSIZE;
1678
1679 if (table <= NEIGH_NR_TABLES)
1680 family = table_to_family[table];
1681
1682 via = nla_data(nla);
1683 via->rtvia_family = family;
1684 memcpy(via->rtvia_addr, addr, alen);
1685 return 0;
1686 }
1687
nla_put_labels(struct sk_buff * skb,int attrtype,u8 labels,const u32 label[])1688 int nla_put_labels(struct sk_buff *skb, int attrtype,
1689 u8 labels, const u32 label[])
1690 {
1691 struct nlattr *nla;
1692 struct mpls_shim_hdr *nla_label;
1693 bool bos;
1694 int i;
1695 nla = nla_reserve(skb, attrtype, labels*4);
1696 if (!nla)
1697 return -EMSGSIZE;
1698
1699 nla_label = nla_data(nla);
1700 bos = true;
1701 for (i = labels - 1; i >= 0; i--) {
1702 nla_label[i] = mpls_entry_encode(label[i], 0, 0, bos);
1703 bos = false;
1704 }
1705
1706 return 0;
1707 }
1708 EXPORT_SYMBOL_GPL(nla_put_labels);
1709
nla_get_labels(const struct nlattr * nla,u8 max_labels,u8 * labels,u32 label[],struct netlink_ext_ack * extack)1710 int nla_get_labels(const struct nlattr *nla, u8 max_labels, u8 *labels,
1711 u32 label[], struct netlink_ext_ack *extack)
1712 {
1713 unsigned len = nla_len(nla);
1714 struct mpls_shim_hdr *nla_label;
1715 u8 nla_labels;
1716 bool bos;
1717 int i;
1718
1719 /* len needs to be an even multiple of 4 (the label size). Number
1720 * of labels is a u8 so check for overflow.
1721 */
1722 if (len & 3 || len / 4 > 255) {
1723 NL_SET_ERR_MSG_ATTR(extack, nla,
1724 "Invalid length for labels attribute");
1725 return -EINVAL;
1726 }
1727
1728 /* Limit the number of new labels allowed */
1729 nla_labels = len/4;
1730 if (nla_labels > max_labels) {
1731 NL_SET_ERR_MSG(extack, "Too many labels");
1732 return -EINVAL;
1733 }
1734
1735 /* when label == NULL, caller wants number of labels */
1736 if (!label)
1737 goto out;
1738
1739 nla_label = nla_data(nla);
1740 bos = true;
1741 for (i = nla_labels - 1; i >= 0; i--, bos = false) {
1742 struct mpls_entry_decoded dec;
1743 dec = mpls_entry_decode(nla_label + i);
1744
1745 /* Ensure the bottom of stack flag is properly set
1746 * and ttl and tc are both clear.
1747 */
1748 if (dec.ttl) {
1749 NL_SET_ERR_MSG_ATTR(extack, nla,
1750 "TTL in label must be 0");
1751 return -EINVAL;
1752 }
1753
1754 if (dec.tc) {
1755 NL_SET_ERR_MSG_ATTR(extack, nla,
1756 "Traffic class in label must be 0");
1757 return -EINVAL;
1758 }
1759
1760 if (dec.bos != bos) {
1761 NL_SET_BAD_ATTR(extack, nla);
1762 if (bos) {
1763 NL_SET_ERR_MSG(extack,
1764 "BOS bit must be set in first label");
1765 } else {
1766 NL_SET_ERR_MSG(extack,
1767 "BOS bit can only be set in first label");
1768 }
1769 return -EINVAL;
1770 }
1771
1772 switch (dec.label) {
1773 case MPLS_LABEL_IMPLNULL:
1774 /* RFC3032: This is a label that an LSR may
1775 * assign and distribute, but which never
1776 * actually appears in the encapsulation.
1777 */
1778 NL_SET_ERR_MSG_ATTR(extack, nla,
1779 "Implicit NULL Label (3) can not be used in encapsulation");
1780 return -EINVAL;
1781 }
1782
1783 label[i] = dec.label;
1784 }
1785 out:
1786 *labels = nla_labels;
1787 return 0;
1788 }
1789 EXPORT_SYMBOL_GPL(nla_get_labels);
1790
rtm_to_route_config(struct sk_buff * skb,struct nlmsghdr * nlh,struct mpls_route_config * cfg,struct netlink_ext_ack * extack)1791 static int rtm_to_route_config(struct sk_buff *skb,
1792 struct nlmsghdr *nlh,
1793 struct mpls_route_config *cfg,
1794 struct netlink_ext_ack *extack)
1795 {
1796 struct rtmsg *rtm;
1797 struct nlattr *tb[RTA_MAX+1];
1798 int index;
1799 int err;
1800
1801 err = nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
1802 rtm_mpls_policy, extack);
1803 if (err < 0)
1804 goto errout;
1805
1806 err = -EINVAL;
1807 rtm = nlmsg_data(nlh);
1808
1809 if (rtm->rtm_family != AF_MPLS) {
1810 NL_SET_ERR_MSG(extack, "Invalid address family in rtmsg");
1811 goto errout;
1812 }
1813 if (rtm->rtm_dst_len != 20) {
1814 NL_SET_ERR_MSG(extack, "rtm_dst_len must be 20 for MPLS");
1815 goto errout;
1816 }
1817 if (rtm->rtm_src_len != 0) {
1818 NL_SET_ERR_MSG(extack, "rtm_src_len must be 0 for MPLS");
1819 goto errout;
1820 }
1821 if (rtm->rtm_tos != 0) {
1822 NL_SET_ERR_MSG(extack, "rtm_tos must be 0 for MPLS");
1823 goto errout;
1824 }
1825 if (rtm->rtm_table != RT_TABLE_MAIN) {
1826 NL_SET_ERR_MSG(extack,
1827 "MPLS only supports the main route table");
1828 goto errout;
1829 }
1830 /* Any value is acceptable for rtm_protocol */
1831
1832 /* As mpls uses destination specific addresses
1833 * (or source specific address in the case of multicast)
1834 * all addresses have universal scope.
1835 */
1836 if (rtm->rtm_scope != RT_SCOPE_UNIVERSE) {
1837 NL_SET_ERR_MSG(extack,
1838 "Invalid route scope - MPLS only supports UNIVERSE");
1839 goto errout;
1840 }
1841 if (rtm->rtm_type != RTN_UNICAST) {
1842 NL_SET_ERR_MSG(extack,
1843 "Invalid route type - MPLS only supports UNICAST");
1844 goto errout;
1845 }
1846 if (rtm->rtm_flags != 0) {
1847 NL_SET_ERR_MSG(extack, "rtm_flags must be 0 for MPLS");
1848 goto errout;
1849 }
1850
1851 cfg->rc_label = LABEL_NOT_SPECIFIED;
1852 cfg->rc_protocol = rtm->rtm_protocol;
1853 cfg->rc_via_table = MPLS_NEIGH_TABLE_UNSPEC;
1854 cfg->rc_ttl_propagate = MPLS_TTL_PROP_DEFAULT;
1855 cfg->rc_nlflags = nlh->nlmsg_flags;
1856 cfg->rc_nlinfo.portid = NETLINK_CB(skb).portid;
1857 cfg->rc_nlinfo.nlh = nlh;
1858 cfg->rc_nlinfo.nl_net = sock_net(skb->sk);
1859
1860 for (index = 0; index <= RTA_MAX; index++) {
1861 struct nlattr *nla = tb[index];
1862 if (!nla)
1863 continue;
1864
1865 switch (index) {
1866 case RTA_OIF:
1867 cfg->rc_ifindex = nla_get_u32(nla);
1868 break;
1869 case RTA_NEWDST:
1870 if (nla_get_labels(nla, MAX_NEW_LABELS,
1871 &cfg->rc_output_labels,
1872 cfg->rc_output_label, extack))
1873 goto errout;
1874 break;
1875 case RTA_DST:
1876 {
1877 u8 label_count;
1878 if (nla_get_labels(nla, 1, &label_count,
1879 &cfg->rc_label, extack))
1880 goto errout;
1881
1882 if (!mpls_label_ok(cfg->rc_nlinfo.nl_net,
1883 &cfg->rc_label, extack))
1884 goto errout;
1885 break;
1886 }
1887 case RTA_GATEWAY:
1888 NL_SET_ERR_MSG(extack, "MPLS does not support RTA_GATEWAY attribute");
1889 goto errout;
1890 case RTA_VIA:
1891 {
1892 if (nla_get_via(nla, &cfg->rc_via_alen,
1893 &cfg->rc_via_table, cfg->rc_via,
1894 extack))
1895 goto errout;
1896 break;
1897 }
1898 case RTA_MULTIPATH:
1899 {
1900 cfg->rc_mp = nla_data(nla);
1901 cfg->rc_mp_len = nla_len(nla);
1902 break;
1903 }
1904 case RTA_TTL_PROPAGATE:
1905 {
1906 u8 ttl_propagate = nla_get_u8(nla);
1907
1908 if (ttl_propagate > 1) {
1909 NL_SET_ERR_MSG_ATTR(extack, nla,
1910 "RTA_TTL_PROPAGATE can only be 0 or 1");
1911 goto errout;
1912 }
1913 cfg->rc_ttl_propagate = ttl_propagate ?
1914 MPLS_TTL_PROP_ENABLED :
1915 MPLS_TTL_PROP_DISABLED;
1916 break;
1917 }
1918 default:
1919 NL_SET_ERR_MSG_ATTR(extack, nla, "Unknown attribute");
1920 /* Unsupported attribute */
1921 goto errout;
1922 }
1923 }
1924
1925 err = 0;
1926 errout:
1927 return err;
1928 }
1929
mpls_rtm_delroute(struct sk_buff * skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack)1930 static int mpls_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
1931 struct netlink_ext_ack *extack)
1932 {
1933 struct mpls_route_config *cfg;
1934 int err;
1935
1936 cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
1937 if (!cfg)
1938 return -ENOMEM;
1939
1940 err = rtm_to_route_config(skb, nlh, cfg, extack);
1941 if (err < 0)
1942 goto out;
1943
1944 err = mpls_route_del(cfg, extack);
1945 out:
1946 kfree(cfg);
1947
1948 return err;
1949 }
1950
1951
mpls_rtm_newroute(struct sk_buff * skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack)1952 static int mpls_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
1953 struct netlink_ext_ack *extack)
1954 {
1955 struct mpls_route_config *cfg;
1956 int err;
1957
1958 cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
1959 if (!cfg)
1960 return -ENOMEM;
1961
1962 err = rtm_to_route_config(skb, nlh, cfg, extack);
1963 if (err < 0)
1964 goto out;
1965
1966 err = mpls_route_add(cfg, extack);
1967 out:
1968 kfree(cfg);
1969
1970 return err;
1971 }
1972
mpls_dump_route(struct sk_buff * skb,u32 portid,u32 seq,int event,u32 label,struct mpls_route * rt,int flags)1973 static int mpls_dump_route(struct sk_buff *skb, u32 portid, u32 seq, int event,
1974 u32 label, struct mpls_route *rt, int flags)
1975 {
1976 struct net_device *dev;
1977 struct nlmsghdr *nlh;
1978 struct rtmsg *rtm;
1979
1980 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), flags);
1981 if (nlh == NULL)
1982 return -EMSGSIZE;
1983
1984 rtm = nlmsg_data(nlh);
1985 rtm->rtm_family = AF_MPLS;
1986 rtm->rtm_dst_len = 20;
1987 rtm->rtm_src_len = 0;
1988 rtm->rtm_tos = 0;
1989 rtm->rtm_table = RT_TABLE_MAIN;
1990 rtm->rtm_protocol = rt->rt_protocol;
1991 rtm->rtm_scope = RT_SCOPE_UNIVERSE;
1992 rtm->rtm_type = RTN_UNICAST;
1993 rtm->rtm_flags = 0;
1994
1995 if (nla_put_labels(skb, RTA_DST, 1, &label))
1996 goto nla_put_failure;
1997
1998 if (rt->rt_ttl_propagate != MPLS_TTL_PROP_DEFAULT) {
1999 bool ttl_propagate =
2000 rt->rt_ttl_propagate == MPLS_TTL_PROP_ENABLED;
2001
2002 if (nla_put_u8(skb, RTA_TTL_PROPAGATE,
2003 ttl_propagate))
2004 goto nla_put_failure;
2005 }
2006 if (rt->rt_nhn == 1) {
2007 const struct mpls_nh *nh = rt->rt_nh;
2008
2009 if (nh->nh_labels &&
2010 nla_put_labels(skb, RTA_NEWDST, nh->nh_labels,
2011 nh->nh_label))
2012 goto nla_put_failure;
2013 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC &&
2014 nla_put_via(skb, nh->nh_via_table, mpls_nh_via(rt, nh),
2015 nh->nh_via_alen))
2016 goto nla_put_failure;
2017 dev = nh->nh_dev;
2018 if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex))
2019 goto nla_put_failure;
2020 if (nh->nh_flags & RTNH_F_LINKDOWN)
2021 rtm->rtm_flags |= RTNH_F_LINKDOWN;
2022 if (nh->nh_flags & RTNH_F_DEAD)
2023 rtm->rtm_flags |= RTNH_F_DEAD;
2024 } else {
2025 struct rtnexthop *rtnh;
2026 struct nlattr *mp;
2027 u8 linkdown = 0;
2028 u8 dead = 0;
2029
2030 mp = nla_nest_start_noflag(skb, RTA_MULTIPATH);
2031 if (!mp)
2032 goto nla_put_failure;
2033
2034 for_nexthops(rt) {
2035 dev = nh->nh_dev;
2036 if (!dev)
2037 continue;
2038
2039 rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh));
2040 if (!rtnh)
2041 goto nla_put_failure;
2042
2043 rtnh->rtnh_ifindex = dev->ifindex;
2044 if (nh->nh_flags & RTNH_F_LINKDOWN) {
2045 rtnh->rtnh_flags |= RTNH_F_LINKDOWN;
2046 linkdown++;
2047 }
2048 if (nh->nh_flags & RTNH_F_DEAD) {
2049 rtnh->rtnh_flags |= RTNH_F_DEAD;
2050 dead++;
2051 }
2052
2053 if (nh->nh_labels && nla_put_labels(skb, RTA_NEWDST,
2054 nh->nh_labels,
2055 nh->nh_label))
2056 goto nla_put_failure;
2057 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC &&
2058 nla_put_via(skb, nh->nh_via_table,
2059 mpls_nh_via(rt, nh),
2060 nh->nh_via_alen))
2061 goto nla_put_failure;
2062
2063 /* length of rtnetlink header + attributes */
2064 rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *)rtnh;
2065 } endfor_nexthops(rt);
2066
2067 if (linkdown == rt->rt_nhn)
2068 rtm->rtm_flags |= RTNH_F_LINKDOWN;
2069 if (dead == rt->rt_nhn)
2070 rtm->rtm_flags |= RTNH_F_DEAD;
2071
2072 nla_nest_end(skb, mp);
2073 }
2074
2075 nlmsg_end(skb, nlh);
2076 return 0;
2077
2078 nla_put_failure:
2079 nlmsg_cancel(skb, nlh);
2080 return -EMSGSIZE;
2081 }
2082
2083 #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)2084 static int mpls_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
2085 struct fib_dump_filter *filter,
2086 struct netlink_callback *cb)
2087 {
2088 return ip_valid_fib_dump_req(net, nlh, filter, cb);
2089 }
2090 #else
mpls_valid_fib_dump_req(struct net * net,const struct nlmsghdr * nlh,struct fib_dump_filter * filter,struct netlink_callback * cb)2091 static int mpls_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
2092 struct fib_dump_filter *filter,
2093 struct netlink_callback *cb)
2094 {
2095 struct netlink_ext_ack *extack = cb->extack;
2096 struct nlattr *tb[RTA_MAX + 1];
2097 struct rtmsg *rtm;
2098 int err, i;
2099
2100 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
2101 NL_SET_ERR_MSG_MOD(extack, "Invalid header for FIB dump request");
2102 return -EINVAL;
2103 }
2104
2105 rtm = nlmsg_data(nlh);
2106 if (rtm->rtm_dst_len || rtm->rtm_src_len || rtm->rtm_tos ||
2107 rtm->rtm_table || rtm->rtm_scope || rtm->rtm_type ||
2108 rtm->rtm_flags) {
2109 NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for FIB dump request");
2110 return -EINVAL;
2111 }
2112
2113 if (rtm->rtm_protocol) {
2114 filter->protocol = rtm->rtm_protocol;
2115 filter->filter_set = 1;
2116 cb->answer_flags = NLM_F_DUMP_FILTERED;
2117 }
2118
2119 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
2120 rtm_mpls_policy, extack);
2121 if (err < 0)
2122 return err;
2123
2124 for (i = 0; i <= RTA_MAX; ++i) {
2125 int ifindex;
2126
2127 if (i == RTA_OIF) {
2128 ifindex = nla_get_u32(tb[i]);
2129 filter->dev = __dev_get_by_index(net, ifindex);
2130 if (!filter->dev)
2131 return -ENODEV;
2132 filter->filter_set = 1;
2133 } else if (tb[i]) {
2134 NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in dump request");
2135 return -EINVAL;
2136 }
2137 }
2138
2139 return 0;
2140 }
2141 #endif
2142
mpls_rt_uses_dev(struct mpls_route * rt,const struct net_device * dev)2143 static bool mpls_rt_uses_dev(struct mpls_route *rt,
2144 const struct net_device *dev)
2145 {
2146 if (rt->rt_nhn == 1) {
2147 struct mpls_nh *nh = rt->rt_nh;
2148
2149 if (nh->nh_dev == dev)
2150 return true;
2151 } else {
2152 for_nexthops(rt) {
2153 if (nh->nh_dev == dev)
2154 return true;
2155 } endfor_nexthops(rt);
2156 }
2157
2158 return false;
2159 }
2160
mpls_dump_routes(struct sk_buff * skb,struct netlink_callback * cb)2161 static int mpls_dump_routes(struct sk_buff *skb, struct netlink_callback *cb)
2162 {
2163 const struct nlmsghdr *nlh = cb->nlh;
2164 struct net *net = sock_net(skb->sk);
2165 struct mpls_route __rcu **platform_label;
2166 struct fib_dump_filter filter = {};
2167 unsigned int flags = NLM_F_MULTI;
2168 size_t platform_labels;
2169 unsigned int index;
2170
2171 ASSERT_RTNL();
2172
2173 if (cb->strict_check) {
2174 int err;
2175
2176 err = mpls_valid_fib_dump_req(net, nlh, &filter, cb);
2177 if (err < 0)
2178 return err;
2179
2180 /* for MPLS, there is only 1 table with fixed type and flags.
2181 * If either are set in the filter then return nothing.
2182 */
2183 if ((filter.table_id && filter.table_id != RT_TABLE_MAIN) ||
2184 (filter.rt_type && filter.rt_type != RTN_UNICAST) ||
2185 filter.flags)
2186 return skb->len;
2187 }
2188
2189 index = cb->args[0];
2190 if (index < MPLS_LABEL_FIRST_UNRESERVED)
2191 index = MPLS_LABEL_FIRST_UNRESERVED;
2192
2193 platform_label = rtnl_dereference(net->mpls.platform_label);
2194 platform_labels = net->mpls.platform_labels;
2195
2196 if (filter.filter_set)
2197 flags |= NLM_F_DUMP_FILTERED;
2198
2199 for (; index < platform_labels; index++) {
2200 struct mpls_route *rt;
2201
2202 rt = rtnl_dereference(platform_label[index]);
2203 if (!rt)
2204 continue;
2205
2206 if ((filter.dev && !mpls_rt_uses_dev(rt, filter.dev)) ||
2207 (filter.protocol && rt->rt_protocol != filter.protocol))
2208 continue;
2209
2210 if (mpls_dump_route(skb, NETLINK_CB(cb->skb).portid,
2211 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
2212 index, rt, flags) < 0)
2213 break;
2214 }
2215 cb->args[0] = index;
2216
2217 return skb->len;
2218 }
2219
lfib_nlmsg_size(struct mpls_route * rt)2220 static inline size_t lfib_nlmsg_size(struct mpls_route *rt)
2221 {
2222 size_t payload =
2223 NLMSG_ALIGN(sizeof(struct rtmsg))
2224 + nla_total_size(4) /* RTA_DST */
2225 + nla_total_size(1); /* RTA_TTL_PROPAGATE */
2226
2227 if (rt->rt_nhn == 1) {
2228 struct mpls_nh *nh = rt->rt_nh;
2229
2230 if (nh->nh_dev)
2231 payload += nla_total_size(4); /* RTA_OIF */
2232 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC) /* RTA_VIA */
2233 payload += nla_total_size(2 + nh->nh_via_alen);
2234 if (nh->nh_labels) /* RTA_NEWDST */
2235 payload += nla_total_size(nh->nh_labels * 4);
2236 } else {
2237 /* each nexthop is packed in an attribute */
2238 size_t nhsize = 0;
2239
2240 for_nexthops(rt) {
2241 if (!nh->nh_dev)
2242 continue;
2243 nhsize += nla_total_size(sizeof(struct rtnexthop));
2244 /* RTA_VIA */
2245 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC)
2246 nhsize += nla_total_size(2 + nh->nh_via_alen);
2247 if (nh->nh_labels)
2248 nhsize += nla_total_size(nh->nh_labels * 4);
2249 } endfor_nexthops(rt);
2250 /* nested attribute */
2251 payload += nla_total_size(nhsize);
2252 }
2253
2254 return payload;
2255 }
2256
rtmsg_lfib(int event,u32 label,struct mpls_route * rt,struct nlmsghdr * nlh,struct net * net,u32 portid,unsigned int nlm_flags)2257 static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt,
2258 struct nlmsghdr *nlh, struct net *net, u32 portid,
2259 unsigned int nlm_flags)
2260 {
2261 struct sk_buff *skb;
2262 u32 seq = nlh ? nlh->nlmsg_seq : 0;
2263 int err = -ENOBUFS;
2264
2265 skb = nlmsg_new(lfib_nlmsg_size(rt), GFP_KERNEL);
2266 if (skb == NULL)
2267 goto errout;
2268
2269 err = mpls_dump_route(skb, portid, seq, event, label, rt, nlm_flags);
2270 if (err < 0) {
2271 /* -EMSGSIZE implies BUG in lfib_nlmsg_size */
2272 WARN_ON(err == -EMSGSIZE);
2273 kfree_skb(skb);
2274 goto errout;
2275 }
2276 rtnl_notify(skb, net, portid, RTNLGRP_MPLS_ROUTE, nlh, GFP_KERNEL);
2277
2278 return;
2279 errout:
2280 if (err < 0)
2281 rtnl_set_sk_err(net, RTNLGRP_MPLS_ROUTE, err);
2282 }
2283
mpls_valid_getroute_req(struct sk_buff * skb,const struct nlmsghdr * nlh,struct nlattr ** tb,struct netlink_ext_ack * extack)2284 static int mpls_valid_getroute_req(struct sk_buff *skb,
2285 const struct nlmsghdr *nlh,
2286 struct nlattr **tb,
2287 struct netlink_ext_ack *extack)
2288 {
2289 struct rtmsg *rtm;
2290 int i, err;
2291
2292 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
2293 NL_SET_ERR_MSG_MOD(extack,
2294 "Invalid header for get route request");
2295 return -EINVAL;
2296 }
2297
2298 if (!netlink_strict_get_check(skb))
2299 return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
2300 rtm_mpls_policy, extack);
2301
2302 rtm = nlmsg_data(nlh);
2303 if ((rtm->rtm_dst_len && rtm->rtm_dst_len != 20) ||
2304 rtm->rtm_src_len || rtm->rtm_tos || rtm->rtm_table ||
2305 rtm->rtm_protocol || rtm->rtm_scope || rtm->rtm_type) {
2306 NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for get route request");
2307 return -EINVAL;
2308 }
2309 if (rtm->rtm_flags & ~RTM_F_FIB_MATCH) {
2310 NL_SET_ERR_MSG_MOD(extack,
2311 "Invalid flags for get route request");
2312 return -EINVAL;
2313 }
2314
2315 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
2316 rtm_mpls_policy, extack);
2317 if (err)
2318 return err;
2319
2320 if ((tb[RTA_DST] || tb[RTA_NEWDST]) && !rtm->rtm_dst_len) {
2321 NL_SET_ERR_MSG_MOD(extack, "rtm_dst_len must be 20 for MPLS");
2322 return -EINVAL;
2323 }
2324
2325 for (i = 0; i <= RTA_MAX; i++) {
2326 if (!tb[i])
2327 continue;
2328
2329 switch (i) {
2330 case RTA_DST:
2331 case RTA_NEWDST:
2332 break;
2333 default:
2334 NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in get route request");
2335 return -EINVAL;
2336 }
2337 }
2338
2339 return 0;
2340 }
2341
mpls_getroute(struct sk_buff * in_skb,struct nlmsghdr * in_nlh,struct netlink_ext_ack * extack)2342 static int mpls_getroute(struct sk_buff *in_skb, struct nlmsghdr *in_nlh,
2343 struct netlink_ext_ack *extack)
2344 {
2345 struct net *net = sock_net(in_skb->sk);
2346 u32 portid = NETLINK_CB(in_skb).portid;
2347 u32 in_label = LABEL_NOT_SPECIFIED;
2348 struct nlattr *tb[RTA_MAX + 1];
2349 u32 labels[MAX_NEW_LABELS];
2350 struct mpls_shim_hdr *hdr;
2351 unsigned int hdr_size = 0;
2352 const struct mpls_nh *nh;
2353 struct net_device *dev;
2354 struct mpls_route *rt;
2355 struct rtmsg *rtm, *r;
2356 struct nlmsghdr *nlh;
2357 struct sk_buff *skb;
2358 u8 n_labels;
2359 int err;
2360
2361 err = mpls_valid_getroute_req(in_skb, in_nlh, tb, extack);
2362 if (err < 0)
2363 goto errout;
2364
2365 rtm = nlmsg_data(in_nlh);
2366
2367 if (tb[RTA_DST]) {
2368 u8 label_count;
2369
2370 if (nla_get_labels(tb[RTA_DST], 1, &label_count,
2371 &in_label, extack)) {
2372 err = -EINVAL;
2373 goto errout;
2374 }
2375
2376 if (!mpls_label_ok(net, &in_label, extack)) {
2377 err = -EINVAL;
2378 goto errout;
2379 }
2380 }
2381
2382 rt = mpls_route_input_rcu(net, in_label);
2383 if (!rt) {
2384 err = -ENETUNREACH;
2385 goto errout;
2386 }
2387
2388 if (rtm->rtm_flags & RTM_F_FIB_MATCH) {
2389 skb = nlmsg_new(lfib_nlmsg_size(rt), GFP_KERNEL);
2390 if (!skb) {
2391 err = -ENOBUFS;
2392 goto errout;
2393 }
2394
2395 err = mpls_dump_route(skb, portid, in_nlh->nlmsg_seq,
2396 RTM_NEWROUTE, in_label, rt, 0);
2397 if (err < 0) {
2398 /* -EMSGSIZE implies BUG in lfib_nlmsg_size */
2399 WARN_ON(err == -EMSGSIZE);
2400 goto errout_free;
2401 }
2402
2403 return rtnl_unicast(skb, net, portid);
2404 }
2405
2406 if (tb[RTA_NEWDST]) {
2407 if (nla_get_labels(tb[RTA_NEWDST], MAX_NEW_LABELS, &n_labels,
2408 labels, extack) != 0) {
2409 err = -EINVAL;
2410 goto errout;
2411 }
2412
2413 hdr_size = n_labels * sizeof(struct mpls_shim_hdr);
2414 }
2415
2416 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2417 if (!skb) {
2418 err = -ENOBUFS;
2419 goto errout;
2420 }
2421
2422 skb->protocol = htons(ETH_P_MPLS_UC);
2423
2424 if (hdr_size) {
2425 bool bos;
2426 int i;
2427
2428 if (skb_cow(skb, hdr_size)) {
2429 err = -ENOBUFS;
2430 goto errout_free;
2431 }
2432
2433 skb_reserve(skb, hdr_size);
2434 skb_push(skb, hdr_size);
2435 skb_reset_network_header(skb);
2436
2437 /* Push new labels */
2438 hdr = mpls_hdr(skb);
2439 bos = true;
2440 for (i = n_labels - 1; i >= 0; i--) {
2441 hdr[i] = mpls_entry_encode(labels[i],
2442 1, 0, bos);
2443 bos = false;
2444 }
2445 }
2446
2447 nh = mpls_select_multipath(rt, skb);
2448 if (!nh) {
2449 err = -ENETUNREACH;
2450 goto errout_free;
2451 }
2452
2453 if (hdr_size) {
2454 skb_pull(skb, hdr_size);
2455 skb_reset_network_header(skb);
2456 }
2457
2458 nlh = nlmsg_put(skb, portid, in_nlh->nlmsg_seq,
2459 RTM_NEWROUTE, sizeof(*r), 0);
2460 if (!nlh) {
2461 err = -EMSGSIZE;
2462 goto errout_free;
2463 }
2464
2465 r = nlmsg_data(nlh);
2466 r->rtm_family = AF_MPLS;
2467 r->rtm_dst_len = 20;
2468 r->rtm_src_len = 0;
2469 r->rtm_table = RT_TABLE_MAIN;
2470 r->rtm_type = RTN_UNICAST;
2471 r->rtm_scope = RT_SCOPE_UNIVERSE;
2472 r->rtm_protocol = rt->rt_protocol;
2473 r->rtm_flags = 0;
2474
2475 if (nla_put_labels(skb, RTA_DST, 1, &in_label))
2476 goto nla_put_failure;
2477
2478 if (nh->nh_labels &&
2479 nla_put_labels(skb, RTA_NEWDST, nh->nh_labels,
2480 nh->nh_label))
2481 goto nla_put_failure;
2482
2483 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC &&
2484 nla_put_via(skb, nh->nh_via_table, mpls_nh_via(rt, nh),
2485 nh->nh_via_alen))
2486 goto nla_put_failure;
2487 dev = nh->nh_dev;
2488 if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex))
2489 goto nla_put_failure;
2490
2491 nlmsg_end(skb, nlh);
2492
2493 err = rtnl_unicast(skb, net, portid);
2494 errout:
2495 return err;
2496
2497 nla_put_failure:
2498 nlmsg_cancel(skb, nlh);
2499 err = -EMSGSIZE;
2500 errout_free:
2501 kfree_skb(skb);
2502 return err;
2503 }
2504
resize_platform_label_table(struct net * net,size_t limit)2505 static int resize_platform_label_table(struct net *net, size_t limit)
2506 {
2507 size_t size = sizeof(struct mpls_route *) * limit;
2508 size_t old_limit;
2509 size_t cp_size;
2510 struct mpls_route __rcu **labels = NULL, **old;
2511 struct mpls_route *rt0 = NULL, *rt2 = NULL;
2512 unsigned index;
2513
2514 if (size) {
2515 labels = kvzalloc(size, GFP_KERNEL);
2516 if (!labels)
2517 goto nolabels;
2518 }
2519
2520 /* In case the predefined labels need to be populated */
2521 if (limit > MPLS_LABEL_IPV4NULL) {
2522 struct net_device *lo = net->loopback_dev;
2523 rt0 = mpls_rt_alloc(1, lo->addr_len, 0);
2524 if (IS_ERR(rt0))
2525 goto nort0;
2526 rt0->rt_nh->nh_dev = lo;
2527 rt0->rt_protocol = RTPROT_KERNEL;
2528 rt0->rt_payload_type = MPT_IPV4;
2529 rt0->rt_ttl_propagate = MPLS_TTL_PROP_DEFAULT;
2530 rt0->rt_nh->nh_via_table = NEIGH_LINK_TABLE;
2531 rt0->rt_nh->nh_via_alen = lo->addr_len;
2532 memcpy(__mpls_nh_via(rt0, rt0->rt_nh), lo->dev_addr,
2533 lo->addr_len);
2534 }
2535 if (limit > MPLS_LABEL_IPV6NULL) {
2536 struct net_device *lo = net->loopback_dev;
2537 rt2 = mpls_rt_alloc(1, lo->addr_len, 0);
2538 if (IS_ERR(rt2))
2539 goto nort2;
2540 rt2->rt_nh->nh_dev = lo;
2541 rt2->rt_protocol = RTPROT_KERNEL;
2542 rt2->rt_payload_type = MPT_IPV6;
2543 rt2->rt_ttl_propagate = MPLS_TTL_PROP_DEFAULT;
2544 rt2->rt_nh->nh_via_table = NEIGH_LINK_TABLE;
2545 rt2->rt_nh->nh_via_alen = lo->addr_len;
2546 memcpy(__mpls_nh_via(rt2, rt2->rt_nh), lo->dev_addr,
2547 lo->addr_len);
2548 }
2549
2550 rtnl_lock();
2551 /* Remember the original table */
2552 old = rtnl_dereference(net->mpls.platform_label);
2553 old_limit = net->mpls.platform_labels;
2554
2555 /* Free any labels beyond the new table */
2556 for (index = limit; index < old_limit; index++)
2557 mpls_route_update(net, index, NULL, NULL);
2558
2559 /* Copy over the old labels */
2560 cp_size = size;
2561 if (old_limit < limit)
2562 cp_size = old_limit * sizeof(struct mpls_route *);
2563
2564 memcpy(labels, old, cp_size);
2565
2566 /* If needed set the predefined labels */
2567 if ((old_limit <= MPLS_LABEL_IPV6NULL) &&
2568 (limit > MPLS_LABEL_IPV6NULL)) {
2569 RCU_INIT_POINTER(labels[MPLS_LABEL_IPV6NULL], rt2);
2570 rt2 = NULL;
2571 }
2572
2573 if ((old_limit <= MPLS_LABEL_IPV4NULL) &&
2574 (limit > MPLS_LABEL_IPV4NULL)) {
2575 RCU_INIT_POINTER(labels[MPLS_LABEL_IPV4NULL], rt0);
2576 rt0 = NULL;
2577 }
2578
2579 /* Update the global pointers */
2580 net->mpls.platform_labels = limit;
2581 rcu_assign_pointer(net->mpls.platform_label, labels);
2582
2583 rtnl_unlock();
2584
2585 mpls_rt_free(rt2);
2586 mpls_rt_free(rt0);
2587
2588 if (old) {
2589 synchronize_rcu();
2590 kvfree(old);
2591 }
2592 return 0;
2593
2594 nort2:
2595 mpls_rt_free(rt0);
2596 nort0:
2597 kvfree(labels);
2598 nolabels:
2599 return -ENOMEM;
2600 }
2601
mpls_platform_labels(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)2602 static int mpls_platform_labels(struct ctl_table *table, int write,
2603 void *buffer, size_t *lenp, loff_t *ppos)
2604 {
2605 struct net *net = table->data;
2606 int platform_labels = net->mpls.platform_labels;
2607 int ret;
2608 struct ctl_table tmp = {
2609 .procname = table->procname,
2610 .data = &platform_labels,
2611 .maxlen = sizeof(int),
2612 .mode = table->mode,
2613 .extra1 = SYSCTL_ZERO,
2614 .extra2 = &label_limit,
2615 };
2616
2617 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
2618
2619 if (write && ret == 0)
2620 ret = resize_platform_label_table(net, platform_labels);
2621
2622 return ret;
2623 }
2624
2625 #define MPLS_NS_SYSCTL_OFFSET(field) \
2626 (&((struct net *)0)->field)
2627
2628 static const struct ctl_table mpls_table[] = {
2629 {
2630 .procname = "platform_labels",
2631 .data = NULL,
2632 .maxlen = sizeof(int),
2633 .mode = 0644,
2634 .proc_handler = mpls_platform_labels,
2635 },
2636 {
2637 .procname = "ip_ttl_propagate",
2638 .data = MPLS_NS_SYSCTL_OFFSET(mpls.ip_ttl_propagate),
2639 .maxlen = sizeof(int),
2640 .mode = 0644,
2641 .proc_handler = proc_dointvec_minmax,
2642 .extra1 = SYSCTL_ZERO,
2643 .extra2 = SYSCTL_ONE,
2644 },
2645 {
2646 .procname = "default_ttl",
2647 .data = MPLS_NS_SYSCTL_OFFSET(mpls.default_ttl),
2648 .maxlen = sizeof(int),
2649 .mode = 0644,
2650 .proc_handler = proc_dointvec_minmax,
2651 .extra1 = SYSCTL_ONE,
2652 .extra2 = &ttl_max,
2653 },
2654 { }
2655 };
2656
mpls_net_init(struct net * net)2657 static int mpls_net_init(struct net *net)
2658 {
2659 struct ctl_table *table;
2660 int i;
2661
2662 net->mpls.platform_labels = 0;
2663 net->mpls.platform_label = NULL;
2664 net->mpls.ip_ttl_propagate = 1;
2665 net->mpls.default_ttl = 255;
2666
2667 table = kmemdup(mpls_table, sizeof(mpls_table), GFP_KERNEL);
2668 if (table == NULL)
2669 return -ENOMEM;
2670
2671 /* Table data contains only offsets relative to the base of
2672 * the mdev at this point, so make them absolute.
2673 */
2674 for (i = 0; i < ARRAY_SIZE(mpls_table) - 1; i++)
2675 table[i].data = (char *)net + (uintptr_t)table[i].data;
2676
2677 net->mpls.ctl = register_net_sysctl_sz(net, "net/mpls", table,
2678 ARRAY_SIZE(mpls_table));
2679 if (net->mpls.ctl == NULL) {
2680 kfree(table);
2681 return -ENOMEM;
2682 }
2683
2684 return 0;
2685 }
2686
mpls_net_exit(struct net * net)2687 static void mpls_net_exit(struct net *net)
2688 {
2689 struct mpls_route __rcu **platform_label;
2690 size_t platform_labels;
2691 struct ctl_table *table;
2692 unsigned int index;
2693
2694 table = net->mpls.ctl->ctl_table_arg;
2695 unregister_net_sysctl_table(net->mpls.ctl);
2696 kfree(table);
2697
2698 /* An rcu grace period has passed since there was a device in
2699 * the network namespace (and thus the last in flight packet)
2700 * left this network namespace. This is because
2701 * unregister_netdevice_many and netdev_run_todo has completed
2702 * for each network device that was in this network namespace.
2703 *
2704 * As such no additional rcu synchronization is necessary when
2705 * freeing the platform_label table.
2706 */
2707 rtnl_lock();
2708 platform_label = rtnl_dereference(net->mpls.platform_label);
2709 platform_labels = net->mpls.platform_labels;
2710 for (index = 0; index < platform_labels; index++) {
2711 struct mpls_route *rt = rtnl_dereference(platform_label[index]);
2712 RCU_INIT_POINTER(platform_label[index], NULL);
2713 mpls_notify_route(net, index, rt, NULL, NULL);
2714 mpls_rt_free(rt);
2715 }
2716 rtnl_unlock();
2717
2718 kvfree(platform_label);
2719 }
2720
2721 static struct pernet_operations mpls_net_ops = {
2722 .init = mpls_net_init,
2723 .exit = mpls_net_exit,
2724 };
2725
2726 static struct rtnl_af_ops mpls_af_ops __read_mostly = {
2727 .family = AF_MPLS,
2728 .fill_stats_af = mpls_fill_stats_af,
2729 .get_stats_af_size = mpls_get_stats_af_size,
2730 };
2731
2732 static const struct rtnl_msg_handler mpls_rtnl_msg_handlers[] __initdata_or_module = {
2733 {THIS_MODULE, PF_MPLS, RTM_NEWROUTE, mpls_rtm_newroute, NULL, 0},
2734 {THIS_MODULE, PF_MPLS, RTM_DELROUTE, mpls_rtm_delroute, NULL, 0},
2735 {THIS_MODULE, PF_MPLS, RTM_GETROUTE, mpls_getroute, mpls_dump_routes, 0},
2736 {THIS_MODULE, PF_MPLS, RTM_GETNETCONF,
2737 mpls_netconf_get_devconf, mpls_netconf_dump_devconf,
2738 RTNL_FLAG_DUMP_UNLOCKED},
2739 };
2740
mpls_init(void)2741 static int __init mpls_init(void)
2742 {
2743 int err;
2744
2745 BUILD_BUG_ON(sizeof(struct mpls_shim_hdr) != 4);
2746
2747 err = register_pernet_subsys(&mpls_net_ops);
2748 if (err)
2749 goto out;
2750
2751 err = register_netdevice_notifier(&mpls_dev_notifier);
2752 if (err)
2753 goto out_unregister_pernet;
2754
2755 dev_add_pack(&mpls_packet_type);
2756
2757 rtnl_af_register(&mpls_af_ops);
2758
2759 err = rtnl_register_many(mpls_rtnl_msg_handlers);
2760 if (err)
2761 goto out_unregister_rtnl_af;
2762
2763 err = ipgre_tunnel_encap_add_mpls_ops();
2764 if (err) {
2765 pr_err("Can't add mpls over gre tunnel ops\n");
2766 goto out_unregister_rtnl;
2767 }
2768
2769 err = 0;
2770 out:
2771 return err;
2772
2773 out_unregister_rtnl:
2774 rtnl_unregister_many(mpls_rtnl_msg_handlers);
2775 out_unregister_rtnl_af:
2776 rtnl_af_unregister(&mpls_af_ops);
2777 dev_remove_pack(&mpls_packet_type);
2778 out_unregister_pernet:
2779 unregister_pernet_subsys(&mpls_net_ops);
2780 goto out;
2781 }
2782 module_init(mpls_init);
2783
mpls_exit(void)2784 static void __exit mpls_exit(void)
2785 {
2786 rtnl_unregister_all(PF_MPLS);
2787 rtnl_af_unregister(&mpls_af_ops);
2788 dev_remove_pack(&mpls_packet_type);
2789 unregister_netdevice_notifier(&mpls_dev_notifier);
2790 unregister_pernet_subsys(&mpls_net_ops);
2791 ipgre_tunnel_encap_del_mpls_ops();
2792 }
2793 module_exit(mpls_exit);
2794
2795 MODULE_DESCRIPTION("MultiProtocol Label Switching");
2796 MODULE_LICENSE("GPL v2");
2797 MODULE_ALIAS_NETPROTO(PF_MPLS);
2798