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 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 hlist_head *head;
1307 struct net_device *dev;
1308 struct mpls_dev *mdev;
1309 int idx, s_idx;
1310 int h, s_h;
1311
1312 if (cb->strict_check) {
1313 struct netlink_ext_ack *extack = cb->extack;
1314 struct netconfmsg *ncm;
1315
1316 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ncm))) {
1317 NL_SET_ERR_MSG_MOD(extack, "Invalid header for netconf dump request");
1318 return -EINVAL;
1319 }
1320
1321 if (nlmsg_attrlen(nlh, sizeof(*ncm))) {
1322 NL_SET_ERR_MSG_MOD(extack, "Invalid data after header in netconf dump request");
1323 return -EINVAL;
1324 }
1325 }
1326
1327 s_h = cb->args[0];
1328 s_idx = idx = cb->args[1];
1329
1330 for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {
1331 idx = 0;
1332 head = &net->dev_index_head[h];
1333 rcu_read_lock();
1334 cb->seq = net->dev_base_seq;
1335 hlist_for_each_entry_rcu(dev, head, index_hlist) {
1336 if (idx < s_idx)
1337 goto cont;
1338 mdev = mpls_dev_get(dev);
1339 if (!mdev)
1340 goto cont;
1341 if (mpls_netconf_fill_devconf(skb, mdev,
1342 NETLINK_CB(cb->skb).portid,
1343 nlh->nlmsg_seq,
1344 RTM_NEWNETCONF,
1345 NLM_F_MULTI,
1346 NETCONFA_ALL) < 0) {
1347 rcu_read_unlock();
1348 goto done;
1349 }
1350 nl_dump_check_consistent(cb, nlmsg_hdr(skb));
1351 cont:
1352 idx++;
1353 }
1354 rcu_read_unlock();
1355 }
1356 done:
1357 cb->args[0] = h;
1358 cb->args[1] = idx;
1359
1360 return skb->len;
1361 }
1362
1363 #define MPLS_PERDEV_SYSCTL_OFFSET(field) \
1364 (&((struct mpls_dev *)0)->field)
1365
mpls_conf_proc(struct ctl_table * ctl,int write,void * buffer,size_t * lenp,loff_t * ppos)1366 static int mpls_conf_proc(struct ctl_table *ctl, int write,
1367 void *buffer, size_t *lenp, loff_t *ppos)
1368 {
1369 int oval = *(int *)ctl->data;
1370 int ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
1371
1372 if (write) {
1373 struct mpls_dev *mdev = ctl->extra1;
1374 int i = (int *)ctl->data - (int *)mdev;
1375 struct net *net = ctl->extra2;
1376 int val = *(int *)ctl->data;
1377
1378 if (i == offsetof(struct mpls_dev, input_enabled) &&
1379 val != oval) {
1380 mpls_netconf_notify_devconf(net, RTM_NEWNETCONF,
1381 NETCONFA_INPUT, mdev);
1382 }
1383 }
1384
1385 return ret;
1386 }
1387
1388 static const struct ctl_table mpls_dev_table[] = {
1389 {
1390 .procname = "input",
1391 .maxlen = sizeof(int),
1392 .mode = 0644,
1393 .proc_handler = mpls_conf_proc,
1394 .data = MPLS_PERDEV_SYSCTL_OFFSET(input_enabled),
1395 },
1396 { }
1397 };
1398
mpls_dev_sysctl_register(struct net_device * dev,struct mpls_dev * mdev)1399 static int mpls_dev_sysctl_register(struct net_device *dev,
1400 struct mpls_dev *mdev)
1401 {
1402 char path[sizeof("net/mpls/conf/") + IFNAMSIZ];
1403 struct net *net = dev_net(dev);
1404 struct ctl_table *table;
1405 int i;
1406
1407 table = kmemdup(&mpls_dev_table, sizeof(mpls_dev_table), GFP_KERNEL);
1408 if (!table)
1409 goto out;
1410
1411 /* Table data contains only offsets relative to the base of
1412 * the mdev at this point, so make them absolute.
1413 */
1414 for (i = 0; i < ARRAY_SIZE(mpls_dev_table); i++) {
1415 table[i].data = (char *)mdev + (uintptr_t)table[i].data;
1416 table[i].extra1 = mdev;
1417 table[i].extra2 = net;
1418 }
1419
1420 snprintf(path, sizeof(path), "net/mpls/conf/%s", dev->name);
1421
1422 mdev->sysctl = register_net_sysctl_sz(net, path, table,
1423 ARRAY_SIZE(mpls_dev_table));
1424 if (!mdev->sysctl)
1425 goto free;
1426
1427 mpls_netconf_notify_devconf(net, RTM_NEWNETCONF, NETCONFA_ALL, mdev);
1428 return 0;
1429
1430 free:
1431 kfree(table);
1432 out:
1433 mdev->sysctl = NULL;
1434 return -ENOBUFS;
1435 }
1436
mpls_dev_sysctl_unregister(struct net_device * dev,struct mpls_dev * mdev)1437 static void mpls_dev_sysctl_unregister(struct net_device *dev,
1438 struct mpls_dev *mdev)
1439 {
1440 struct net *net = dev_net(dev);
1441 struct ctl_table *table;
1442
1443 if (!mdev->sysctl)
1444 return;
1445
1446 table = mdev->sysctl->ctl_table_arg;
1447 unregister_net_sysctl_table(mdev->sysctl);
1448 kfree(table);
1449
1450 mpls_netconf_notify_devconf(net, RTM_DELNETCONF, 0, mdev);
1451 }
1452
mpls_add_dev(struct net_device * dev)1453 static struct mpls_dev *mpls_add_dev(struct net_device *dev)
1454 {
1455 struct mpls_dev *mdev;
1456 int err = -ENOMEM;
1457 int i;
1458
1459 ASSERT_RTNL();
1460
1461 mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
1462 if (!mdev)
1463 return ERR_PTR(err);
1464
1465 mdev->stats = alloc_percpu(struct mpls_pcpu_stats);
1466 if (!mdev->stats)
1467 goto free;
1468
1469 for_each_possible_cpu(i) {
1470 struct mpls_pcpu_stats *mpls_stats;
1471
1472 mpls_stats = per_cpu_ptr(mdev->stats, i);
1473 u64_stats_init(&mpls_stats->syncp);
1474 }
1475
1476 mdev->dev = dev;
1477
1478 err = mpls_dev_sysctl_register(dev, mdev);
1479 if (err)
1480 goto free;
1481
1482 rcu_assign_pointer(dev->mpls_ptr, mdev);
1483
1484 return mdev;
1485
1486 free:
1487 free_percpu(mdev->stats);
1488 kfree(mdev);
1489 return ERR_PTR(err);
1490 }
1491
mpls_dev_destroy_rcu(struct rcu_head * head)1492 static void mpls_dev_destroy_rcu(struct rcu_head *head)
1493 {
1494 struct mpls_dev *mdev = container_of(head, struct mpls_dev, rcu);
1495
1496 free_percpu(mdev->stats);
1497 kfree(mdev);
1498 }
1499
mpls_ifdown(struct net_device * dev,int event)1500 static int mpls_ifdown(struct net_device *dev, int event)
1501 {
1502 struct mpls_route __rcu **platform_label;
1503 struct net *net = dev_net(dev);
1504 unsigned index;
1505
1506 platform_label = rtnl_dereference(net->mpls.platform_label);
1507 for (index = 0; index < net->mpls.platform_labels; index++) {
1508 struct mpls_route *rt = rtnl_dereference(platform_label[index]);
1509 bool nh_del = false;
1510 u8 alive = 0;
1511
1512 if (!rt)
1513 continue;
1514
1515 if (event == NETDEV_UNREGISTER) {
1516 u8 deleted = 0;
1517
1518 for_nexthops(rt) {
1519 if (!nh->nh_dev || nh->nh_dev == dev)
1520 deleted++;
1521 if (nh->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 = kmemdup(orig, size, GFP_KERNEL);
1537 if (!rt)
1538 return -ENOMEM;
1539 }
1540 }
1541
1542 change_nexthops(rt) {
1543 unsigned int nh_flags = nh->nh_flags;
1544
1545 if (nh->nh_dev != dev)
1546 goto next;
1547
1548 switch (event) {
1549 case NETDEV_DOWN:
1550 case NETDEV_UNREGISTER:
1551 nh_flags |= RTNH_F_DEAD;
1552 fallthrough;
1553 case NETDEV_CHANGE:
1554 nh_flags |= RTNH_F_LINKDOWN;
1555 break;
1556 }
1557 if (event == NETDEV_UNREGISTER)
1558 nh->nh_dev = NULL;
1559
1560 if (nh->nh_flags != nh_flags)
1561 WRITE_ONCE(nh->nh_flags, nh_flags);
1562 next:
1563 if (!(nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)))
1564 alive++;
1565 } endfor_nexthops(rt);
1566
1567 WRITE_ONCE(rt->rt_nhn_alive, alive);
1568
1569 if (nh_del)
1570 mpls_route_update(net, index, rt, NULL);
1571 }
1572
1573 return 0;
1574 }
1575
mpls_ifup(struct net_device * dev,unsigned int flags)1576 static void mpls_ifup(struct net_device *dev, unsigned int flags)
1577 {
1578 struct mpls_route __rcu **platform_label;
1579 struct net *net = dev_net(dev);
1580 unsigned index;
1581 u8 alive;
1582
1583 platform_label = rtnl_dereference(net->mpls.platform_label);
1584 for (index = 0; index < net->mpls.platform_labels; index++) {
1585 struct mpls_route *rt = rtnl_dereference(platform_label[index]);
1586
1587 if (!rt)
1588 continue;
1589
1590 alive = 0;
1591 change_nexthops(rt) {
1592 unsigned int nh_flags = nh->nh_flags;
1593
1594 if (!(nh_flags & flags)) {
1595 alive++;
1596 continue;
1597 }
1598 if (nh->nh_dev != dev)
1599 continue;
1600 alive++;
1601 nh_flags &= ~flags;
1602 WRITE_ONCE(nh->nh_flags, nh_flags);
1603 } endfor_nexthops(rt);
1604
1605 WRITE_ONCE(rt->rt_nhn_alive, alive);
1606 }
1607 }
1608
mpls_dev_notify(struct notifier_block * this,unsigned long event,void * ptr)1609 static int mpls_dev_notify(struct notifier_block *this, unsigned long event,
1610 void *ptr)
1611 {
1612 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1613 struct mpls_dev *mdev;
1614 unsigned int flags;
1615 int err;
1616
1617 if (event == NETDEV_REGISTER) {
1618 mdev = mpls_add_dev(dev);
1619 if (IS_ERR(mdev))
1620 return notifier_from_errno(PTR_ERR(mdev));
1621
1622 return NOTIFY_OK;
1623 }
1624
1625 mdev = mpls_dev_get(dev);
1626 if (!mdev)
1627 return NOTIFY_OK;
1628
1629 switch (event) {
1630
1631 case NETDEV_DOWN:
1632 err = mpls_ifdown(dev, event);
1633 if (err)
1634 return notifier_from_errno(err);
1635 break;
1636 case NETDEV_UP:
1637 flags = dev_get_flags(dev);
1638 if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1639 mpls_ifup(dev, RTNH_F_DEAD | RTNH_F_LINKDOWN);
1640 else
1641 mpls_ifup(dev, RTNH_F_DEAD);
1642 break;
1643 case NETDEV_CHANGE:
1644 flags = dev_get_flags(dev);
1645 if (flags & (IFF_RUNNING | IFF_LOWER_UP)) {
1646 mpls_ifup(dev, RTNH_F_DEAD | RTNH_F_LINKDOWN);
1647 } else {
1648 err = mpls_ifdown(dev, event);
1649 if (err)
1650 return notifier_from_errno(err);
1651 }
1652 break;
1653 case NETDEV_UNREGISTER:
1654 err = mpls_ifdown(dev, event);
1655 if (err)
1656 return notifier_from_errno(err);
1657 mdev = mpls_dev_get(dev);
1658 if (mdev) {
1659 mpls_dev_sysctl_unregister(dev, mdev);
1660 RCU_INIT_POINTER(dev->mpls_ptr, NULL);
1661 call_rcu(&mdev->rcu, mpls_dev_destroy_rcu);
1662 }
1663 break;
1664 case NETDEV_CHANGENAME:
1665 mdev = mpls_dev_get(dev);
1666 if (mdev) {
1667 mpls_dev_sysctl_unregister(dev, mdev);
1668 err = mpls_dev_sysctl_register(dev, mdev);
1669 if (err)
1670 return notifier_from_errno(err);
1671 }
1672 break;
1673 }
1674 return NOTIFY_OK;
1675 }
1676
1677 static struct notifier_block mpls_dev_notifier = {
1678 .notifier_call = mpls_dev_notify,
1679 };
1680
nla_put_via(struct sk_buff * skb,u8 table,const void * addr,int alen)1681 static int nla_put_via(struct sk_buff *skb,
1682 u8 table, const void *addr, int alen)
1683 {
1684 static const int table_to_family[NEIGH_NR_TABLES + 1] = {
1685 AF_INET, AF_INET6, AF_DECnet, AF_PACKET,
1686 };
1687 struct nlattr *nla;
1688 struct rtvia *via;
1689 int family = AF_UNSPEC;
1690
1691 nla = nla_reserve(skb, RTA_VIA, alen + 2);
1692 if (!nla)
1693 return -EMSGSIZE;
1694
1695 if (table <= NEIGH_NR_TABLES)
1696 family = table_to_family[table];
1697
1698 via = nla_data(nla);
1699 via->rtvia_family = family;
1700 memcpy(via->rtvia_addr, addr, alen);
1701 return 0;
1702 }
1703
nla_put_labels(struct sk_buff * skb,int attrtype,u8 labels,const u32 label[])1704 int nla_put_labels(struct sk_buff *skb, int attrtype,
1705 u8 labels, const u32 label[])
1706 {
1707 struct nlattr *nla;
1708 struct mpls_shim_hdr *nla_label;
1709 bool bos;
1710 int i;
1711 nla = nla_reserve(skb, attrtype, labels*4);
1712 if (!nla)
1713 return -EMSGSIZE;
1714
1715 nla_label = nla_data(nla);
1716 bos = true;
1717 for (i = labels - 1; i >= 0; i--) {
1718 nla_label[i] = mpls_entry_encode(label[i], 0, 0, bos);
1719 bos = false;
1720 }
1721
1722 return 0;
1723 }
1724 EXPORT_SYMBOL_GPL(nla_put_labels);
1725
nla_get_labels(const struct nlattr * nla,u8 max_labels,u8 * labels,u32 label[],struct netlink_ext_ack * extack)1726 int nla_get_labels(const struct nlattr *nla, u8 max_labels, u8 *labels,
1727 u32 label[], struct netlink_ext_ack *extack)
1728 {
1729 unsigned len = nla_len(nla);
1730 struct mpls_shim_hdr *nla_label;
1731 u8 nla_labels;
1732 bool bos;
1733 int i;
1734
1735 /* len needs to be an even multiple of 4 (the label size). Number
1736 * of labels is a u8 so check for overflow.
1737 */
1738 if (len & 3 || len / 4 > 255) {
1739 NL_SET_ERR_MSG_ATTR(extack, nla,
1740 "Invalid length for labels attribute");
1741 return -EINVAL;
1742 }
1743
1744 /* Limit the number of new labels allowed */
1745 nla_labels = len/4;
1746 if (nla_labels > max_labels) {
1747 NL_SET_ERR_MSG(extack, "Too many labels");
1748 return -EINVAL;
1749 }
1750
1751 /* when label == NULL, caller wants number of labels */
1752 if (!label)
1753 goto out;
1754
1755 nla_label = nla_data(nla);
1756 bos = true;
1757 for (i = nla_labels - 1; i >= 0; i--, bos = false) {
1758 struct mpls_entry_decoded dec;
1759 dec = mpls_entry_decode(nla_label + i);
1760
1761 /* Ensure the bottom of stack flag is properly set
1762 * and ttl and tc are both clear.
1763 */
1764 if (dec.ttl) {
1765 NL_SET_ERR_MSG_ATTR(extack, nla,
1766 "TTL in label must be 0");
1767 return -EINVAL;
1768 }
1769
1770 if (dec.tc) {
1771 NL_SET_ERR_MSG_ATTR(extack, nla,
1772 "Traffic class in label must be 0");
1773 return -EINVAL;
1774 }
1775
1776 if (dec.bos != bos) {
1777 NL_SET_BAD_ATTR(extack, nla);
1778 if (bos) {
1779 NL_SET_ERR_MSG(extack,
1780 "BOS bit must be set in first label");
1781 } else {
1782 NL_SET_ERR_MSG(extack,
1783 "BOS bit can only be set in first label");
1784 }
1785 return -EINVAL;
1786 }
1787
1788 switch (dec.label) {
1789 case MPLS_LABEL_IMPLNULL:
1790 /* RFC3032: This is a label that an LSR may
1791 * assign and distribute, but which never
1792 * actually appears in the encapsulation.
1793 */
1794 NL_SET_ERR_MSG_ATTR(extack, nla,
1795 "Implicit NULL Label (3) can not be used in encapsulation");
1796 return -EINVAL;
1797 }
1798
1799 label[i] = dec.label;
1800 }
1801 out:
1802 *labels = nla_labels;
1803 return 0;
1804 }
1805 EXPORT_SYMBOL_GPL(nla_get_labels);
1806
rtm_to_route_config(struct sk_buff * skb,struct nlmsghdr * nlh,struct mpls_route_config * cfg,struct netlink_ext_ack * extack)1807 static int rtm_to_route_config(struct sk_buff *skb,
1808 struct nlmsghdr *nlh,
1809 struct mpls_route_config *cfg,
1810 struct netlink_ext_ack *extack)
1811 {
1812 struct rtmsg *rtm;
1813 struct nlattr *tb[RTA_MAX+1];
1814 int index;
1815 int err;
1816
1817 err = nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
1818 rtm_mpls_policy, extack);
1819 if (err < 0)
1820 goto errout;
1821
1822 err = -EINVAL;
1823 rtm = nlmsg_data(nlh);
1824
1825 if (rtm->rtm_family != AF_MPLS) {
1826 NL_SET_ERR_MSG(extack, "Invalid address family in rtmsg");
1827 goto errout;
1828 }
1829 if (rtm->rtm_dst_len != 20) {
1830 NL_SET_ERR_MSG(extack, "rtm_dst_len must be 20 for MPLS");
1831 goto errout;
1832 }
1833 if (rtm->rtm_src_len != 0) {
1834 NL_SET_ERR_MSG(extack, "rtm_src_len must be 0 for MPLS");
1835 goto errout;
1836 }
1837 if (rtm->rtm_tos != 0) {
1838 NL_SET_ERR_MSG(extack, "rtm_tos must be 0 for MPLS");
1839 goto errout;
1840 }
1841 if (rtm->rtm_table != RT_TABLE_MAIN) {
1842 NL_SET_ERR_MSG(extack,
1843 "MPLS only supports the main route table");
1844 goto errout;
1845 }
1846 /* Any value is acceptable for rtm_protocol */
1847
1848 /* As mpls uses destination specific addresses
1849 * (or source specific address in the case of multicast)
1850 * all addresses have universal scope.
1851 */
1852 if (rtm->rtm_scope != RT_SCOPE_UNIVERSE) {
1853 NL_SET_ERR_MSG(extack,
1854 "Invalid route scope - MPLS only supports UNIVERSE");
1855 goto errout;
1856 }
1857 if (rtm->rtm_type != RTN_UNICAST) {
1858 NL_SET_ERR_MSG(extack,
1859 "Invalid route type - MPLS only supports UNICAST");
1860 goto errout;
1861 }
1862 if (rtm->rtm_flags != 0) {
1863 NL_SET_ERR_MSG(extack, "rtm_flags must be 0 for MPLS");
1864 goto errout;
1865 }
1866
1867 cfg->rc_label = LABEL_NOT_SPECIFIED;
1868 cfg->rc_protocol = rtm->rtm_protocol;
1869 cfg->rc_via_table = MPLS_NEIGH_TABLE_UNSPEC;
1870 cfg->rc_ttl_propagate = MPLS_TTL_PROP_DEFAULT;
1871 cfg->rc_nlflags = nlh->nlmsg_flags;
1872 cfg->rc_nlinfo.portid = NETLINK_CB(skb).portid;
1873 cfg->rc_nlinfo.nlh = nlh;
1874 cfg->rc_nlinfo.nl_net = sock_net(skb->sk);
1875
1876 for (index = 0; index <= RTA_MAX; index++) {
1877 struct nlattr *nla = tb[index];
1878 if (!nla)
1879 continue;
1880
1881 switch (index) {
1882 case RTA_OIF:
1883 cfg->rc_ifindex = nla_get_u32(nla);
1884 break;
1885 case RTA_NEWDST:
1886 if (nla_get_labels(nla, MAX_NEW_LABELS,
1887 &cfg->rc_output_labels,
1888 cfg->rc_output_label, extack))
1889 goto errout;
1890 break;
1891 case RTA_DST:
1892 {
1893 u8 label_count;
1894 if (nla_get_labels(nla, 1, &label_count,
1895 &cfg->rc_label, extack))
1896 goto errout;
1897
1898 if (!mpls_label_ok(cfg->rc_nlinfo.nl_net,
1899 &cfg->rc_label, extack))
1900 goto errout;
1901 break;
1902 }
1903 case RTA_GATEWAY:
1904 NL_SET_ERR_MSG(extack, "MPLS does not support RTA_GATEWAY attribute");
1905 goto errout;
1906 case RTA_VIA:
1907 {
1908 if (nla_get_via(nla, &cfg->rc_via_alen,
1909 &cfg->rc_via_table, cfg->rc_via,
1910 extack))
1911 goto errout;
1912 break;
1913 }
1914 case RTA_MULTIPATH:
1915 {
1916 cfg->rc_mp = nla_data(nla);
1917 cfg->rc_mp_len = nla_len(nla);
1918 break;
1919 }
1920 case RTA_TTL_PROPAGATE:
1921 {
1922 u8 ttl_propagate = nla_get_u8(nla);
1923
1924 if (ttl_propagate > 1) {
1925 NL_SET_ERR_MSG_ATTR(extack, nla,
1926 "RTA_TTL_PROPAGATE can only be 0 or 1");
1927 goto errout;
1928 }
1929 cfg->rc_ttl_propagate = ttl_propagate ?
1930 MPLS_TTL_PROP_ENABLED :
1931 MPLS_TTL_PROP_DISABLED;
1932 break;
1933 }
1934 default:
1935 NL_SET_ERR_MSG_ATTR(extack, nla, "Unknown attribute");
1936 /* Unsupported attribute */
1937 goto errout;
1938 }
1939 }
1940
1941 err = 0;
1942 errout:
1943 return err;
1944 }
1945
mpls_rtm_delroute(struct sk_buff * skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack)1946 static int mpls_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
1947 struct netlink_ext_ack *extack)
1948 {
1949 struct mpls_route_config *cfg;
1950 int err;
1951
1952 cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
1953 if (!cfg)
1954 return -ENOMEM;
1955
1956 err = rtm_to_route_config(skb, nlh, cfg, extack);
1957 if (err < 0)
1958 goto out;
1959
1960 err = mpls_route_del(cfg, extack);
1961 out:
1962 kfree(cfg);
1963
1964 return err;
1965 }
1966
1967
mpls_rtm_newroute(struct sk_buff * skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack)1968 static int mpls_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
1969 struct netlink_ext_ack *extack)
1970 {
1971 struct mpls_route_config *cfg;
1972 int err;
1973
1974 cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
1975 if (!cfg)
1976 return -ENOMEM;
1977
1978 err = rtm_to_route_config(skb, nlh, cfg, extack);
1979 if (err < 0)
1980 goto out;
1981
1982 err = mpls_route_add(cfg, extack);
1983 out:
1984 kfree(cfg);
1985
1986 return err;
1987 }
1988
mpls_dump_route(struct sk_buff * skb,u32 portid,u32 seq,int event,u32 label,struct mpls_route * rt,int flags)1989 static int mpls_dump_route(struct sk_buff *skb, u32 portid, u32 seq, int event,
1990 u32 label, struct mpls_route *rt, int flags)
1991 {
1992 struct net_device *dev;
1993 struct nlmsghdr *nlh;
1994 struct rtmsg *rtm;
1995
1996 nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), flags);
1997 if (nlh == NULL)
1998 return -EMSGSIZE;
1999
2000 rtm = nlmsg_data(nlh);
2001 rtm->rtm_family = AF_MPLS;
2002 rtm->rtm_dst_len = 20;
2003 rtm->rtm_src_len = 0;
2004 rtm->rtm_tos = 0;
2005 rtm->rtm_table = RT_TABLE_MAIN;
2006 rtm->rtm_protocol = rt->rt_protocol;
2007 rtm->rtm_scope = RT_SCOPE_UNIVERSE;
2008 rtm->rtm_type = RTN_UNICAST;
2009 rtm->rtm_flags = 0;
2010
2011 if (nla_put_labels(skb, RTA_DST, 1, &label))
2012 goto nla_put_failure;
2013
2014 if (rt->rt_ttl_propagate != MPLS_TTL_PROP_DEFAULT) {
2015 bool ttl_propagate =
2016 rt->rt_ttl_propagate == MPLS_TTL_PROP_ENABLED;
2017
2018 if (nla_put_u8(skb, RTA_TTL_PROPAGATE,
2019 ttl_propagate))
2020 goto nla_put_failure;
2021 }
2022 if (rt->rt_nhn == 1) {
2023 const struct mpls_nh *nh = rt->rt_nh;
2024
2025 if (nh->nh_labels &&
2026 nla_put_labels(skb, RTA_NEWDST, nh->nh_labels,
2027 nh->nh_label))
2028 goto nla_put_failure;
2029 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC &&
2030 nla_put_via(skb, nh->nh_via_table, mpls_nh_via(rt, nh),
2031 nh->nh_via_alen))
2032 goto nla_put_failure;
2033 dev = nh->nh_dev;
2034 if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex))
2035 goto nla_put_failure;
2036 if (nh->nh_flags & RTNH_F_LINKDOWN)
2037 rtm->rtm_flags |= RTNH_F_LINKDOWN;
2038 if (nh->nh_flags & RTNH_F_DEAD)
2039 rtm->rtm_flags |= RTNH_F_DEAD;
2040 } else {
2041 struct rtnexthop *rtnh;
2042 struct nlattr *mp;
2043 u8 linkdown = 0;
2044 u8 dead = 0;
2045
2046 mp = nla_nest_start_noflag(skb, RTA_MULTIPATH);
2047 if (!mp)
2048 goto nla_put_failure;
2049
2050 for_nexthops(rt) {
2051 dev = nh->nh_dev;
2052 if (!dev)
2053 continue;
2054
2055 rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh));
2056 if (!rtnh)
2057 goto nla_put_failure;
2058
2059 rtnh->rtnh_ifindex = dev->ifindex;
2060 if (nh->nh_flags & RTNH_F_LINKDOWN) {
2061 rtnh->rtnh_flags |= RTNH_F_LINKDOWN;
2062 linkdown++;
2063 }
2064 if (nh->nh_flags & RTNH_F_DEAD) {
2065 rtnh->rtnh_flags |= RTNH_F_DEAD;
2066 dead++;
2067 }
2068
2069 if (nh->nh_labels && nla_put_labels(skb, RTA_NEWDST,
2070 nh->nh_labels,
2071 nh->nh_label))
2072 goto nla_put_failure;
2073 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC &&
2074 nla_put_via(skb, nh->nh_via_table,
2075 mpls_nh_via(rt, nh),
2076 nh->nh_via_alen))
2077 goto nla_put_failure;
2078
2079 /* length of rtnetlink header + attributes */
2080 rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *)rtnh;
2081 } endfor_nexthops(rt);
2082
2083 if (linkdown == rt->rt_nhn)
2084 rtm->rtm_flags |= RTNH_F_LINKDOWN;
2085 if (dead == rt->rt_nhn)
2086 rtm->rtm_flags |= RTNH_F_DEAD;
2087
2088 nla_nest_end(skb, mp);
2089 }
2090
2091 nlmsg_end(skb, nlh);
2092 return 0;
2093
2094 nla_put_failure:
2095 nlmsg_cancel(skb, nlh);
2096 return -EMSGSIZE;
2097 }
2098
2099 #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)2100 static int mpls_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
2101 struct fib_dump_filter *filter,
2102 struct netlink_callback *cb)
2103 {
2104 return ip_valid_fib_dump_req(net, nlh, filter, cb);
2105 }
2106 #else
mpls_valid_fib_dump_req(struct net * net,const struct nlmsghdr * nlh,struct fib_dump_filter * filter,struct netlink_callback * cb)2107 static int mpls_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
2108 struct fib_dump_filter *filter,
2109 struct netlink_callback *cb)
2110 {
2111 struct netlink_ext_ack *extack = cb->extack;
2112 struct nlattr *tb[RTA_MAX + 1];
2113 struct rtmsg *rtm;
2114 int err, i;
2115
2116 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
2117 NL_SET_ERR_MSG_MOD(extack, "Invalid header for FIB dump request");
2118 return -EINVAL;
2119 }
2120
2121 rtm = nlmsg_data(nlh);
2122 if (rtm->rtm_dst_len || rtm->rtm_src_len || rtm->rtm_tos ||
2123 rtm->rtm_table || rtm->rtm_scope || rtm->rtm_type ||
2124 rtm->rtm_flags) {
2125 NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for FIB dump request");
2126 return -EINVAL;
2127 }
2128
2129 if (rtm->rtm_protocol) {
2130 filter->protocol = rtm->rtm_protocol;
2131 filter->filter_set = 1;
2132 cb->answer_flags = NLM_F_DUMP_FILTERED;
2133 }
2134
2135 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
2136 rtm_mpls_policy, extack);
2137 if (err < 0)
2138 return err;
2139
2140 for (i = 0; i <= RTA_MAX; ++i) {
2141 int ifindex;
2142
2143 if (i == RTA_OIF) {
2144 ifindex = nla_get_u32(tb[i]);
2145 filter->dev = __dev_get_by_index(net, ifindex);
2146 if (!filter->dev)
2147 return -ENODEV;
2148 filter->filter_set = 1;
2149 } else if (tb[i]) {
2150 NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in dump request");
2151 return -EINVAL;
2152 }
2153 }
2154
2155 return 0;
2156 }
2157 #endif
2158
mpls_rt_uses_dev(struct mpls_route * rt,const struct net_device * dev)2159 static bool mpls_rt_uses_dev(struct mpls_route *rt,
2160 const struct net_device *dev)
2161 {
2162 if (rt->rt_nhn == 1) {
2163 struct mpls_nh *nh = rt->rt_nh;
2164
2165 if (nh->nh_dev == dev)
2166 return true;
2167 } else {
2168 for_nexthops(rt) {
2169 if (nh->nh_dev == dev)
2170 return true;
2171 } endfor_nexthops(rt);
2172 }
2173
2174 return false;
2175 }
2176
mpls_dump_routes(struct sk_buff * skb,struct netlink_callback * cb)2177 static int mpls_dump_routes(struct sk_buff *skb, struct netlink_callback *cb)
2178 {
2179 const struct nlmsghdr *nlh = cb->nlh;
2180 struct net *net = sock_net(skb->sk);
2181 struct mpls_route __rcu **platform_label;
2182 struct fib_dump_filter filter = {};
2183 unsigned int flags = NLM_F_MULTI;
2184 size_t platform_labels;
2185 unsigned int index;
2186
2187 ASSERT_RTNL();
2188
2189 if (cb->strict_check) {
2190 int err;
2191
2192 err = mpls_valid_fib_dump_req(net, nlh, &filter, cb);
2193 if (err < 0)
2194 return err;
2195
2196 /* for MPLS, there is only 1 table with fixed type and flags.
2197 * If either are set in the filter then return nothing.
2198 */
2199 if ((filter.table_id && filter.table_id != RT_TABLE_MAIN) ||
2200 (filter.rt_type && filter.rt_type != RTN_UNICAST) ||
2201 filter.flags)
2202 return skb->len;
2203 }
2204
2205 index = cb->args[0];
2206 if (index < MPLS_LABEL_FIRST_UNRESERVED)
2207 index = MPLS_LABEL_FIRST_UNRESERVED;
2208
2209 platform_label = rtnl_dereference(net->mpls.platform_label);
2210 platform_labels = net->mpls.platform_labels;
2211
2212 if (filter.filter_set)
2213 flags |= NLM_F_DUMP_FILTERED;
2214
2215 for (; index < platform_labels; index++) {
2216 struct mpls_route *rt;
2217
2218 rt = rtnl_dereference(platform_label[index]);
2219 if (!rt)
2220 continue;
2221
2222 if ((filter.dev && !mpls_rt_uses_dev(rt, filter.dev)) ||
2223 (filter.protocol && rt->rt_protocol != filter.protocol))
2224 continue;
2225
2226 if (mpls_dump_route(skb, NETLINK_CB(cb->skb).portid,
2227 cb->nlh->nlmsg_seq, RTM_NEWROUTE,
2228 index, rt, flags) < 0)
2229 break;
2230 }
2231 cb->args[0] = index;
2232
2233 return skb->len;
2234 }
2235
lfib_nlmsg_size(struct mpls_route * rt)2236 static inline size_t lfib_nlmsg_size(struct mpls_route *rt)
2237 {
2238 size_t payload =
2239 NLMSG_ALIGN(sizeof(struct rtmsg))
2240 + nla_total_size(4) /* RTA_DST */
2241 + nla_total_size(1); /* RTA_TTL_PROPAGATE */
2242
2243 if (rt->rt_nhn == 1) {
2244 struct mpls_nh *nh = rt->rt_nh;
2245
2246 if (nh->nh_dev)
2247 payload += nla_total_size(4); /* RTA_OIF */
2248 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC) /* RTA_VIA */
2249 payload += nla_total_size(2 + nh->nh_via_alen);
2250 if (nh->nh_labels) /* RTA_NEWDST */
2251 payload += nla_total_size(nh->nh_labels * 4);
2252 } else {
2253 /* each nexthop is packed in an attribute */
2254 size_t nhsize = 0;
2255
2256 for_nexthops(rt) {
2257 if (!nh->nh_dev)
2258 continue;
2259 nhsize += nla_total_size(sizeof(struct rtnexthop));
2260 /* RTA_VIA */
2261 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC)
2262 nhsize += nla_total_size(2 + nh->nh_via_alen);
2263 if (nh->nh_labels)
2264 nhsize += nla_total_size(nh->nh_labels * 4);
2265 } endfor_nexthops(rt);
2266 /* nested attribute */
2267 payload += nla_total_size(nhsize);
2268 }
2269
2270 return payload;
2271 }
2272
rtmsg_lfib(int event,u32 label,struct mpls_route * rt,struct nlmsghdr * nlh,struct net * net,u32 portid,unsigned int nlm_flags)2273 static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt,
2274 struct nlmsghdr *nlh, struct net *net, u32 portid,
2275 unsigned int nlm_flags)
2276 {
2277 struct sk_buff *skb;
2278 u32 seq = nlh ? nlh->nlmsg_seq : 0;
2279 int err = -ENOBUFS;
2280
2281 skb = nlmsg_new(lfib_nlmsg_size(rt), GFP_KERNEL);
2282 if (skb == NULL)
2283 goto errout;
2284
2285 err = mpls_dump_route(skb, portid, seq, event, label, rt, nlm_flags);
2286 if (err < 0) {
2287 /* -EMSGSIZE implies BUG in lfib_nlmsg_size */
2288 WARN_ON(err == -EMSGSIZE);
2289 kfree_skb(skb);
2290 goto errout;
2291 }
2292 rtnl_notify(skb, net, portid, RTNLGRP_MPLS_ROUTE, nlh, GFP_KERNEL);
2293
2294 return;
2295 errout:
2296 if (err < 0)
2297 rtnl_set_sk_err(net, RTNLGRP_MPLS_ROUTE, err);
2298 }
2299
mpls_valid_getroute_req(struct sk_buff * skb,const struct nlmsghdr * nlh,struct nlattr ** tb,struct netlink_ext_ack * extack)2300 static int mpls_valid_getroute_req(struct sk_buff *skb,
2301 const struct nlmsghdr *nlh,
2302 struct nlattr **tb,
2303 struct netlink_ext_ack *extack)
2304 {
2305 struct rtmsg *rtm;
2306 int i, err;
2307
2308 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
2309 NL_SET_ERR_MSG_MOD(extack,
2310 "Invalid header for get route request");
2311 return -EINVAL;
2312 }
2313
2314 if (!netlink_strict_get_check(skb))
2315 return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
2316 rtm_mpls_policy, extack);
2317
2318 rtm = nlmsg_data(nlh);
2319 if ((rtm->rtm_dst_len && rtm->rtm_dst_len != 20) ||
2320 rtm->rtm_src_len || rtm->rtm_tos || rtm->rtm_table ||
2321 rtm->rtm_protocol || rtm->rtm_scope || rtm->rtm_type) {
2322 NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for get route request");
2323 return -EINVAL;
2324 }
2325 if (rtm->rtm_flags & ~RTM_F_FIB_MATCH) {
2326 NL_SET_ERR_MSG_MOD(extack,
2327 "Invalid flags for get route request");
2328 return -EINVAL;
2329 }
2330
2331 err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
2332 rtm_mpls_policy, extack);
2333 if (err)
2334 return err;
2335
2336 if ((tb[RTA_DST] || tb[RTA_NEWDST]) && !rtm->rtm_dst_len) {
2337 NL_SET_ERR_MSG_MOD(extack, "rtm_dst_len must be 20 for MPLS");
2338 return -EINVAL;
2339 }
2340
2341 for (i = 0; i <= RTA_MAX; i++) {
2342 if (!tb[i])
2343 continue;
2344
2345 switch (i) {
2346 case RTA_DST:
2347 case RTA_NEWDST:
2348 break;
2349 default:
2350 NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in get route request");
2351 return -EINVAL;
2352 }
2353 }
2354
2355 return 0;
2356 }
2357
mpls_getroute(struct sk_buff * in_skb,struct nlmsghdr * in_nlh,struct netlink_ext_ack * extack)2358 static int mpls_getroute(struct sk_buff *in_skb, struct nlmsghdr *in_nlh,
2359 struct netlink_ext_ack *extack)
2360 {
2361 struct net *net = sock_net(in_skb->sk);
2362 u32 portid = NETLINK_CB(in_skb).portid;
2363 u32 in_label = LABEL_NOT_SPECIFIED;
2364 struct nlattr *tb[RTA_MAX + 1];
2365 u32 labels[MAX_NEW_LABELS];
2366 struct mpls_shim_hdr *hdr;
2367 unsigned int hdr_size = 0;
2368 const struct mpls_nh *nh;
2369 struct net_device *dev;
2370 struct mpls_route *rt;
2371 struct rtmsg *rtm, *r;
2372 struct nlmsghdr *nlh;
2373 struct sk_buff *skb;
2374 u8 n_labels;
2375 int err;
2376
2377 err = mpls_valid_getroute_req(in_skb, in_nlh, tb, extack);
2378 if (err < 0)
2379 goto errout;
2380
2381 rtm = nlmsg_data(in_nlh);
2382
2383 if (tb[RTA_DST]) {
2384 u8 label_count;
2385
2386 if (nla_get_labels(tb[RTA_DST], 1, &label_count,
2387 &in_label, extack)) {
2388 err = -EINVAL;
2389 goto errout;
2390 }
2391
2392 if (!mpls_label_ok(net, &in_label, extack)) {
2393 err = -EINVAL;
2394 goto errout;
2395 }
2396 }
2397
2398 rt = mpls_route_input_rcu(net, in_label);
2399 if (!rt) {
2400 err = -ENETUNREACH;
2401 goto errout;
2402 }
2403
2404 if (rtm->rtm_flags & RTM_F_FIB_MATCH) {
2405 skb = nlmsg_new(lfib_nlmsg_size(rt), GFP_KERNEL);
2406 if (!skb) {
2407 err = -ENOBUFS;
2408 goto errout;
2409 }
2410
2411 err = mpls_dump_route(skb, portid, in_nlh->nlmsg_seq,
2412 RTM_NEWROUTE, in_label, rt, 0);
2413 if (err < 0) {
2414 /* -EMSGSIZE implies BUG in lfib_nlmsg_size */
2415 WARN_ON(err == -EMSGSIZE);
2416 goto errout_free;
2417 }
2418
2419 return rtnl_unicast(skb, net, portid);
2420 }
2421
2422 if (tb[RTA_NEWDST]) {
2423 if (nla_get_labels(tb[RTA_NEWDST], MAX_NEW_LABELS, &n_labels,
2424 labels, extack) != 0) {
2425 err = -EINVAL;
2426 goto errout;
2427 }
2428
2429 hdr_size = n_labels * sizeof(struct mpls_shim_hdr);
2430 }
2431
2432 skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2433 if (!skb) {
2434 err = -ENOBUFS;
2435 goto errout;
2436 }
2437
2438 skb->protocol = htons(ETH_P_MPLS_UC);
2439
2440 if (hdr_size) {
2441 bool bos;
2442 int i;
2443
2444 if (skb_cow(skb, hdr_size)) {
2445 err = -ENOBUFS;
2446 goto errout_free;
2447 }
2448
2449 skb_reserve(skb, hdr_size);
2450 skb_push(skb, hdr_size);
2451 skb_reset_network_header(skb);
2452
2453 /* Push new labels */
2454 hdr = mpls_hdr(skb);
2455 bos = true;
2456 for (i = n_labels - 1; i >= 0; i--) {
2457 hdr[i] = mpls_entry_encode(labels[i],
2458 1, 0, bos);
2459 bos = false;
2460 }
2461 }
2462
2463 nh = mpls_select_multipath(rt, skb);
2464 if (!nh) {
2465 err = -ENETUNREACH;
2466 goto errout_free;
2467 }
2468
2469 if (hdr_size) {
2470 skb_pull(skb, hdr_size);
2471 skb_reset_network_header(skb);
2472 }
2473
2474 nlh = nlmsg_put(skb, portid, in_nlh->nlmsg_seq,
2475 RTM_NEWROUTE, sizeof(*r), 0);
2476 if (!nlh) {
2477 err = -EMSGSIZE;
2478 goto errout_free;
2479 }
2480
2481 r = nlmsg_data(nlh);
2482 r->rtm_family = AF_MPLS;
2483 r->rtm_dst_len = 20;
2484 r->rtm_src_len = 0;
2485 r->rtm_table = RT_TABLE_MAIN;
2486 r->rtm_type = RTN_UNICAST;
2487 r->rtm_scope = RT_SCOPE_UNIVERSE;
2488 r->rtm_protocol = rt->rt_protocol;
2489 r->rtm_flags = 0;
2490
2491 if (nla_put_labels(skb, RTA_DST, 1, &in_label))
2492 goto nla_put_failure;
2493
2494 if (nh->nh_labels &&
2495 nla_put_labels(skb, RTA_NEWDST, nh->nh_labels,
2496 nh->nh_label))
2497 goto nla_put_failure;
2498
2499 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC &&
2500 nla_put_via(skb, nh->nh_via_table, mpls_nh_via(rt, nh),
2501 nh->nh_via_alen))
2502 goto nla_put_failure;
2503 dev = nh->nh_dev;
2504 if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex))
2505 goto nla_put_failure;
2506
2507 nlmsg_end(skb, nlh);
2508
2509 err = rtnl_unicast(skb, net, portid);
2510 errout:
2511 return err;
2512
2513 nla_put_failure:
2514 nlmsg_cancel(skb, nlh);
2515 err = -EMSGSIZE;
2516 errout_free:
2517 kfree_skb(skb);
2518 return err;
2519 }
2520
resize_platform_label_table(struct net * net,size_t limit)2521 static int resize_platform_label_table(struct net *net, size_t limit)
2522 {
2523 size_t size = sizeof(struct mpls_route *) * limit;
2524 size_t old_limit;
2525 size_t cp_size;
2526 struct mpls_route __rcu **labels = NULL, **old;
2527 struct mpls_route *rt0 = NULL, *rt2 = NULL;
2528 unsigned index;
2529
2530 if (size) {
2531 labels = kvzalloc(size, GFP_KERNEL);
2532 if (!labels)
2533 goto nolabels;
2534 }
2535
2536 /* In case the predefined labels need to be populated */
2537 if (limit > MPLS_LABEL_IPV4NULL) {
2538 struct net_device *lo = net->loopback_dev;
2539 rt0 = mpls_rt_alloc(1, lo->addr_len, 0);
2540 if (IS_ERR(rt0))
2541 goto nort0;
2542 rt0->rt_nh->nh_dev = lo;
2543 rt0->rt_protocol = RTPROT_KERNEL;
2544 rt0->rt_payload_type = MPT_IPV4;
2545 rt0->rt_ttl_propagate = MPLS_TTL_PROP_DEFAULT;
2546 rt0->rt_nh->nh_via_table = NEIGH_LINK_TABLE;
2547 rt0->rt_nh->nh_via_alen = lo->addr_len;
2548 memcpy(__mpls_nh_via(rt0, rt0->rt_nh), lo->dev_addr,
2549 lo->addr_len);
2550 }
2551 if (limit > MPLS_LABEL_IPV6NULL) {
2552 struct net_device *lo = net->loopback_dev;
2553 rt2 = mpls_rt_alloc(1, lo->addr_len, 0);
2554 if (IS_ERR(rt2))
2555 goto nort2;
2556 rt2->rt_nh->nh_dev = lo;
2557 rt2->rt_protocol = RTPROT_KERNEL;
2558 rt2->rt_payload_type = MPT_IPV6;
2559 rt2->rt_ttl_propagate = MPLS_TTL_PROP_DEFAULT;
2560 rt2->rt_nh->nh_via_table = NEIGH_LINK_TABLE;
2561 rt2->rt_nh->nh_via_alen = lo->addr_len;
2562 memcpy(__mpls_nh_via(rt2, rt2->rt_nh), lo->dev_addr,
2563 lo->addr_len);
2564 }
2565
2566 rtnl_lock();
2567 /* Remember the original table */
2568 old = rtnl_dereference(net->mpls.platform_label);
2569 old_limit = net->mpls.platform_labels;
2570
2571 /* Free any labels beyond the new table */
2572 for (index = limit; index < old_limit; index++)
2573 mpls_route_update(net, index, NULL, NULL);
2574
2575 /* Copy over the old labels */
2576 cp_size = size;
2577 if (old_limit < limit)
2578 cp_size = old_limit * sizeof(struct mpls_route *);
2579
2580 memcpy(labels, old, cp_size);
2581
2582 /* If needed set the predefined labels */
2583 if ((old_limit <= MPLS_LABEL_IPV6NULL) &&
2584 (limit > MPLS_LABEL_IPV6NULL)) {
2585 RCU_INIT_POINTER(labels[MPLS_LABEL_IPV6NULL], rt2);
2586 rt2 = NULL;
2587 }
2588
2589 if ((old_limit <= MPLS_LABEL_IPV4NULL) &&
2590 (limit > MPLS_LABEL_IPV4NULL)) {
2591 RCU_INIT_POINTER(labels[MPLS_LABEL_IPV4NULL], rt0);
2592 rt0 = NULL;
2593 }
2594
2595 /* Update the global pointers */
2596 net->mpls.platform_labels = limit;
2597 rcu_assign_pointer(net->mpls.platform_label, labels);
2598
2599 rtnl_unlock();
2600
2601 mpls_rt_free(rt2);
2602 mpls_rt_free(rt0);
2603
2604 if (old) {
2605 synchronize_rcu();
2606 kvfree(old);
2607 }
2608 return 0;
2609
2610 nort2:
2611 mpls_rt_free(rt0);
2612 nort0:
2613 kvfree(labels);
2614 nolabels:
2615 return -ENOMEM;
2616 }
2617
mpls_platform_labels(struct ctl_table * table,int write,void * buffer,size_t * lenp,loff_t * ppos)2618 static int mpls_platform_labels(struct ctl_table *table, int write,
2619 void *buffer, size_t *lenp, loff_t *ppos)
2620 {
2621 struct net *net = table->data;
2622 int platform_labels = net->mpls.platform_labels;
2623 int ret;
2624 struct ctl_table tmp = {
2625 .procname = table->procname,
2626 .data = &platform_labels,
2627 .maxlen = sizeof(int),
2628 .mode = table->mode,
2629 .extra1 = SYSCTL_ZERO,
2630 .extra2 = &label_limit,
2631 };
2632
2633 ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
2634
2635 if (write && ret == 0)
2636 ret = resize_platform_label_table(net, platform_labels);
2637
2638 return ret;
2639 }
2640
2641 #define MPLS_NS_SYSCTL_OFFSET(field) \
2642 (&((struct net *)0)->field)
2643
2644 static const struct ctl_table mpls_table[] = {
2645 {
2646 .procname = "platform_labels",
2647 .data = NULL,
2648 .maxlen = sizeof(int),
2649 .mode = 0644,
2650 .proc_handler = mpls_platform_labels,
2651 },
2652 {
2653 .procname = "ip_ttl_propagate",
2654 .data = MPLS_NS_SYSCTL_OFFSET(mpls.ip_ttl_propagate),
2655 .maxlen = sizeof(int),
2656 .mode = 0644,
2657 .proc_handler = proc_dointvec_minmax,
2658 .extra1 = SYSCTL_ZERO,
2659 .extra2 = SYSCTL_ONE,
2660 },
2661 {
2662 .procname = "default_ttl",
2663 .data = MPLS_NS_SYSCTL_OFFSET(mpls.default_ttl),
2664 .maxlen = sizeof(int),
2665 .mode = 0644,
2666 .proc_handler = proc_dointvec_minmax,
2667 .extra1 = SYSCTL_ONE,
2668 .extra2 = &ttl_max,
2669 },
2670 { }
2671 };
2672
mpls_net_init(struct net * net)2673 static int mpls_net_init(struct net *net)
2674 {
2675 struct ctl_table *table;
2676 int i;
2677
2678 net->mpls.platform_labels = 0;
2679 net->mpls.platform_label = NULL;
2680 net->mpls.ip_ttl_propagate = 1;
2681 net->mpls.default_ttl = 255;
2682
2683 table = kmemdup(mpls_table, sizeof(mpls_table), GFP_KERNEL);
2684 if (table == NULL)
2685 return -ENOMEM;
2686
2687 /* Table data contains only offsets relative to the base of
2688 * the mdev at this point, so make them absolute.
2689 */
2690 for (i = 0; i < ARRAY_SIZE(mpls_table) - 1; i++)
2691 table[i].data = (char *)net + (uintptr_t)table[i].data;
2692
2693 net->mpls.ctl = register_net_sysctl_sz(net, "net/mpls", table,
2694 ARRAY_SIZE(mpls_table));
2695 if (net->mpls.ctl == NULL) {
2696 kfree(table);
2697 return -ENOMEM;
2698 }
2699
2700 return 0;
2701 }
2702
mpls_net_exit(struct net * net)2703 static void mpls_net_exit(struct net *net)
2704 {
2705 struct mpls_route __rcu **platform_label;
2706 size_t platform_labels;
2707 struct ctl_table *table;
2708 unsigned int index;
2709
2710 table = net->mpls.ctl->ctl_table_arg;
2711 unregister_net_sysctl_table(net->mpls.ctl);
2712 kfree(table);
2713
2714 /* An rcu grace period has passed since there was a device in
2715 * the network namespace (and thus the last in flight packet)
2716 * left this network namespace. This is because
2717 * unregister_netdevice_many and netdev_run_todo has completed
2718 * for each network device that was in this network namespace.
2719 *
2720 * As such no additional rcu synchronization is necessary when
2721 * freeing the platform_label table.
2722 */
2723 rtnl_lock();
2724 platform_label = rtnl_dereference(net->mpls.platform_label);
2725 platform_labels = net->mpls.platform_labels;
2726 for (index = 0; index < platform_labels; index++) {
2727 struct mpls_route *rt = rtnl_dereference(platform_label[index]);
2728 RCU_INIT_POINTER(platform_label[index], NULL);
2729 mpls_notify_route(net, index, rt, NULL, NULL);
2730 mpls_rt_free(rt);
2731 }
2732 rtnl_unlock();
2733
2734 kvfree(platform_label);
2735 }
2736
2737 static struct pernet_operations mpls_net_ops = {
2738 .init = mpls_net_init,
2739 .exit = mpls_net_exit,
2740 };
2741
2742 static struct rtnl_af_ops mpls_af_ops __read_mostly = {
2743 .family = AF_MPLS,
2744 .fill_stats_af = mpls_fill_stats_af,
2745 .get_stats_af_size = mpls_get_stats_af_size,
2746 };
2747
mpls_init(void)2748 static int __init mpls_init(void)
2749 {
2750 int err;
2751
2752 BUILD_BUG_ON(sizeof(struct mpls_shim_hdr) != 4);
2753
2754 err = register_pernet_subsys(&mpls_net_ops);
2755 if (err)
2756 goto out;
2757
2758 err = register_netdevice_notifier(&mpls_dev_notifier);
2759 if (err)
2760 goto out_unregister_pernet;
2761
2762 dev_add_pack(&mpls_packet_type);
2763
2764 rtnl_af_register(&mpls_af_ops);
2765
2766 rtnl_register_module(THIS_MODULE, PF_MPLS, RTM_NEWROUTE,
2767 mpls_rtm_newroute, NULL, 0);
2768 rtnl_register_module(THIS_MODULE, PF_MPLS, RTM_DELROUTE,
2769 mpls_rtm_delroute, NULL, 0);
2770 rtnl_register_module(THIS_MODULE, PF_MPLS, RTM_GETROUTE,
2771 mpls_getroute, mpls_dump_routes, 0);
2772 rtnl_register_module(THIS_MODULE, PF_MPLS, RTM_GETNETCONF,
2773 mpls_netconf_get_devconf,
2774 mpls_netconf_dump_devconf, 0);
2775 err = ipgre_tunnel_encap_add_mpls_ops();
2776 if (err)
2777 pr_err("Can't add mpls over gre tunnel ops\n");
2778
2779 err = 0;
2780 out:
2781 return err;
2782
2783 out_unregister_pernet:
2784 unregister_pernet_subsys(&mpls_net_ops);
2785 goto out;
2786 }
2787 module_init(mpls_init);
2788
mpls_exit(void)2789 static void __exit mpls_exit(void)
2790 {
2791 rtnl_unregister_all(PF_MPLS);
2792 rtnl_af_unregister(&mpls_af_ops);
2793 dev_remove_pack(&mpls_packet_type);
2794 unregister_netdevice_notifier(&mpls_dev_notifier);
2795 unregister_pernet_subsys(&mpls_net_ops);
2796 ipgre_tunnel_encap_del_mpls_ops();
2797 }
2798 module_exit(mpls_exit);
2799
2800 MODULE_DESCRIPTION("MultiProtocol Label Switching");
2801 MODULE_LICENSE("GPL v2");
2802 MODULE_ALIAS_NETPROTO(PF_MPLS);
2803