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TOMOYO Linux Cross Reference
Linux/net/mpls/af_mpls.c

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  1 #include <linux/types.h>
  2 #include <linux/skbuff.h>
  3 #include <linux/socket.h>
  4 #include <linux/sysctl.h>
  5 #include <linux/net.h>
  6 #include <linux/module.h>
  7 #include <linux/if_arp.h>
  8 #include <linux/ipv6.h>
  9 #include <linux/mpls.h>
 10 #include <linux/netconf.h>
 11 #include <linux/nospec.h>
 12 #include <linux/vmalloc.h>
 13 #include <linux/percpu.h>
 14 #include <net/ip.h>
 15 #include <net/dst.h>
 16 #include <net/sock.h>
 17 #include <net/arp.h>
 18 #include <net/ip_fib.h>
 19 #include <net/netevent.h>
 20 #include <net/ip_tunnels.h>
 21 #include <net/netns/generic.h>
 22 #if IS_ENABLED(CONFIG_IPV6)
 23 #include <net/ipv6.h>
 24 #endif
 25 #include <net/addrconf.h>
 26 #include <net/nexthop.h>
 27 #include "internal.h"
 28 
 29 /* max memory we will use for mpls_route */
 30 #define MAX_MPLS_ROUTE_MEM      4096
 31 
 32 /* Maximum number of labels to look ahead at when selecting a path of
 33  * a multipath route
 34  */
 35 #define MAX_MP_SELECT_LABELS 4
 36 
 37 #define MPLS_NEIGH_TABLE_UNSPEC (NEIGH_LINK_TABLE + 1)
 38 
 39 static int zero = 0;
 40 static int one = 1;
 41 static int label_limit = (1 << 20) - 1;
 42 static int ttl_max = 255;
 43 
 44 #if IS_ENABLED(CONFIG_NET_IP_TUNNEL)
 45 static size_t ipgre_mpls_encap_hlen(struct ip_tunnel_encap *e)
 46 {
 47         return sizeof(struct mpls_shim_hdr);
 48 }
 49 
 50 static const struct ip_tunnel_encap_ops mpls_iptun_ops = {
 51         .encap_hlen     = ipgre_mpls_encap_hlen,
 52 };
 53 
 54 static int ipgre_tunnel_encap_add_mpls_ops(void)
 55 {
 56         return ip_tunnel_encap_add_ops(&mpls_iptun_ops, TUNNEL_ENCAP_MPLS);
 57 }
 58 
 59 static void ipgre_tunnel_encap_del_mpls_ops(void)
 60 {
 61         ip_tunnel_encap_del_ops(&mpls_iptun_ops, TUNNEL_ENCAP_MPLS);
 62 }
 63 #else
 64 static int ipgre_tunnel_encap_add_mpls_ops(void)
 65 {
 66         return 0;
 67 }
 68 
 69 static void ipgre_tunnel_encap_del_mpls_ops(void)
 70 {
 71 }
 72 #endif
 73 
 74 static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt,
 75                        struct nlmsghdr *nlh, struct net *net, u32 portid,
 76                        unsigned int nlm_flags);
 77 
 78 static struct mpls_route *mpls_route_input_rcu(struct net *net, unsigned index)
 79 {
 80         struct mpls_route *rt = NULL;
 81 
 82         if (index < net->mpls.platform_labels) {
 83                 struct mpls_route __rcu **platform_label =
 84                         rcu_dereference(net->mpls.platform_label);
 85                 rt = rcu_dereference(platform_label[index]);
 86         }
 87         return rt;
 88 }
 89 
 90 bool mpls_output_possible(const struct net_device *dev)
 91 {
 92         return dev && (dev->flags & IFF_UP) && netif_carrier_ok(dev);
 93 }
 94 EXPORT_SYMBOL_GPL(mpls_output_possible);
 95 
 96 static u8 *__mpls_nh_via(struct mpls_route *rt, struct mpls_nh *nh)
 97 {
 98         return (u8 *)nh + rt->rt_via_offset;
 99 }
100 
101 static const u8 *mpls_nh_via(const struct mpls_route *rt,
102                              const struct mpls_nh *nh)
103 {
104         return __mpls_nh_via((struct mpls_route *)rt, (struct mpls_nh *)nh);
105 }
106 
107 static unsigned int mpls_nh_header_size(const struct mpls_nh *nh)
108 {
109         /* The size of the layer 2.5 labels to be added for this route */
110         return nh->nh_labels * sizeof(struct mpls_shim_hdr);
111 }
112 
113 unsigned int mpls_dev_mtu(const struct net_device *dev)
114 {
115         /* The amount of data the layer 2 frame can hold */
116         return dev->mtu;
117 }
118 EXPORT_SYMBOL_GPL(mpls_dev_mtu);
119 
120 bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu)
121 {
122         if (skb->len <= mtu)
123                 return false;
124 
125         if (skb_is_gso(skb) && skb_gso_validate_mtu(skb, mtu))
126                 return false;
127 
128         return true;
129 }
130 EXPORT_SYMBOL_GPL(mpls_pkt_too_big);
131 
132 void mpls_stats_inc_outucastpkts(struct net_device *dev,
133                                  const struct sk_buff *skb)
134 {
135         struct mpls_dev *mdev;
136 
137         if (skb->protocol == htons(ETH_P_MPLS_UC)) {
138                 mdev = mpls_dev_get(dev);
139                 if (mdev)
140                         MPLS_INC_STATS_LEN(mdev, skb->len,
141                                            tx_packets,
142                                            tx_bytes);
143         } else if (skb->protocol == htons(ETH_P_IP)) {
144                 IP_UPD_PO_STATS(dev_net(dev), IPSTATS_MIB_OUT, skb->len);
145 #if IS_ENABLED(CONFIG_IPV6)
146         } else if (skb->protocol == htons(ETH_P_IPV6)) {
147                 struct inet6_dev *in6dev = __in6_dev_get(dev);
148 
149                 if (in6dev)
150                         IP6_UPD_PO_STATS(dev_net(dev), in6dev,
151                                          IPSTATS_MIB_OUT, skb->len);
152 #endif
153         }
154 }
155 EXPORT_SYMBOL_GPL(mpls_stats_inc_outucastpkts);
156 
157 static u32 mpls_multipath_hash(struct mpls_route *rt, struct sk_buff *skb)
158 {
159         struct mpls_entry_decoded dec;
160         unsigned int mpls_hdr_len = 0;
161         struct mpls_shim_hdr *hdr;
162         bool eli_seen = false;
163         int label_index;
164         u32 hash = 0;
165 
166         for (label_index = 0; label_index < MAX_MP_SELECT_LABELS;
167              label_index++) {
168                 mpls_hdr_len += sizeof(*hdr);
169                 if (!pskb_may_pull(skb, mpls_hdr_len))
170                         break;
171 
172                 /* Read and decode the current label */
173                 hdr = mpls_hdr(skb) + label_index;
174                 dec = mpls_entry_decode(hdr);
175 
176                 /* RFC6790 - reserved labels MUST NOT be used as keys
177                  * for the load-balancing function
178                  */
179                 if (likely(dec.label >= MPLS_LABEL_FIRST_UNRESERVED)) {
180                         hash = jhash_1word(dec.label, hash);
181 
182                         /* The entropy label follows the entropy label
183                          * indicator, so this means that the entropy
184                          * label was just added to the hash - no need to
185                          * go any deeper either in the label stack or in the
186                          * payload
187                          */
188                         if (eli_seen)
189                                 break;
190                 } else if (dec.label == MPLS_LABEL_ENTROPY) {
191                         eli_seen = true;
192                 }
193 
194                 if (!dec.bos)
195                         continue;
196 
197                 /* found bottom label; does skb have room for a header? */
198                 if (pskb_may_pull(skb, mpls_hdr_len + sizeof(struct iphdr))) {
199                         const struct iphdr *v4hdr;
200 
201                         v4hdr = (const struct iphdr *)(hdr + 1);
202                         if (v4hdr->version == 4) {
203                                 hash = jhash_3words(ntohl(v4hdr->saddr),
204                                                     ntohl(v4hdr->daddr),
205                                                     v4hdr->protocol, hash);
206                         } else if (v4hdr->version == 6 &&
207                                    pskb_may_pull(skb, mpls_hdr_len +
208                                                  sizeof(struct ipv6hdr))) {
209                                 const struct ipv6hdr *v6hdr;
210 
211                                 v6hdr = (const struct ipv6hdr *)(hdr + 1);
212                                 hash = __ipv6_addr_jhash(&v6hdr->saddr, hash);
213                                 hash = __ipv6_addr_jhash(&v6hdr->daddr, hash);
214                                 hash = jhash_1word(v6hdr->nexthdr, hash);
215                         }
216                 }
217 
218                 break;
219         }
220 
221         return hash;
222 }
223 
224 static struct mpls_nh *mpls_get_nexthop(struct mpls_route *rt, u8 index)
225 {
226         return (struct mpls_nh *)((u8 *)rt->rt_nh + index * rt->rt_nh_size);
227 }
228 
229 /* number of alive nexthops (rt->rt_nhn_alive) and the flags for
230  * a next hop (nh->nh_flags) are modified by netdev event handlers.
231  * Since those fields can change at any moment, use READ_ONCE to
232  * access both.
233  */
234 static struct mpls_nh *mpls_select_multipath(struct mpls_route *rt,
235                                              struct sk_buff *skb)
236 {
237         u32 hash = 0;
238         int nh_index = 0;
239         int n = 0;
240         u8 alive;
241 
242         /* No need to look further into packet if there's only
243          * one path
244          */
245         if (rt->rt_nhn == 1)
246                 return rt->rt_nh;
247 
248         alive = READ_ONCE(rt->rt_nhn_alive);
249         if (alive == 0)
250                 return NULL;
251 
252         hash = mpls_multipath_hash(rt, skb);
253         nh_index = hash % alive;
254         if (alive == rt->rt_nhn)
255                 goto out;
256         for_nexthops(rt) {
257                 unsigned int nh_flags = READ_ONCE(nh->nh_flags);
258 
259                 if (nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN))
260                         continue;
261                 if (n == nh_index)
262                         return nh;
263                 n++;
264         } endfor_nexthops(rt);
265 
266 out:
267         return mpls_get_nexthop(rt, nh_index);
268 }
269 
270 static bool mpls_egress(struct net *net, struct mpls_route *rt,
271                         struct sk_buff *skb, struct mpls_entry_decoded dec)
272 {
273         enum mpls_payload_type payload_type;
274         bool success = false;
275 
276         /* The IPv4 code below accesses through the IPv4 header
277          * checksum, which is 12 bytes into the packet.
278          * The IPv6 code below accesses through the IPv6 hop limit
279          * which is 8 bytes into the packet.
280          *
281          * For all supported cases there should always be at least 12
282          * bytes of packet data present.  The IPv4 header is 20 bytes
283          * without options and the IPv6 header is always 40 bytes
284          * long.
285          */
286         if (!pskb_may_pull(skb, 12))
287                 return false;
288 
289         payload_type = rt->rt_payload_type;
290         if (payload_type == MPT_UNSPEC)
291                 payload_type = ip_hdr(skb)->version;
292 
293         switch (payload_type) {
294         case MPT_IPV4: {
295                 struct iphdr *hdr4 = ip_hdr(skb);
296                 u8 new_ttl;
297                 skb->protocol = htons(ETH_P_IP);
298 
299                 /* If propagating TTL, take the decremented TTL from
300                  * the incoming MPLS header, otherwise decrement the
301                  * TTL, but only if not 0 to avoid underflow.
302                  */
303                 if (rt->rt_ttl_propagate == MPLS_TTL_PROP_ENABLED ||
304                     (rt->rt_ttl_propagate == MPLS_TTL_PROP_DEFAULT &&
305                      net->mpls.ip_ttl_propagate))
306                         new_ttl = dec.ttl;
307                 else
308                         new_ttl = hdr4->ttl ? hdr4->ttl - 1 : 0;
309 
310                 csum_replace2(&hdr4->check,
311                               htons(hdr4->ttl << 8),
312                               htons(new_ttl << 8));
313                 hdr4->ttl = new_ttl;
314                 success = true;
315                 break;
316         }
317         case MPT_IPV6: {
318                 struct ipv6hdr *hdr6 = ipv6_hdr(skb);
319                 skb->protocol = htons(ETH_P_IPV6);
320 
321                 /* If propagating TTL, take the decremented TTL from
322                  * the incoming MPLS header, otherwise decrement the
323                  * hop limit, but only if not 0 to avoid underflow.
324                  */
325                 if (rt->rt_ttl_propagate == MPLS_TTL_PROP_ENABLED ||
326                     (rt->rt_ttl_propagate == MPLS_TTL_PROP_DEFAULT &&
327                      net->mpls.ip_ttl_propagate))
328                         hdr6->hop_limit = dec.ttl;
329                 else if (hdr6->hop_limit)
330                         hdr6->hop_limit = hdr6->hop_limit - 1;
331                 success = true;
332                 break;
333         }
334         case MPT_UNSPEC:
335                 /* Should have decided which protocol it is by now */
336                 break;
337         }
338 
339         return success;
340 }
341 
342 static int mpls_forward(struct sk_buff *skb, struct net_device *dev,
343                         struct packet_type *pt, struct net_device *orig_dev)
344 {
345         struct net *net = dev_net(dev);
346         struct mpls_shim_hdr *hdr;
347         struct mpls_route *rt;
348         struct mpls_nh *nh;
349         struct mpls_entry_decoded dec;
350         struct net_device *out_dev;
351         struct mpls_dev *out_mdev;
352         struct mpls_dev *mdev;
353         unsigned int hh_len;
354         unsigned int new_header_size;
355         unsigned int mtu;
356         int err;
357 
358         /* Careful this entire function runs inside of an rcu critical section */
359 
360         mdev = mpls_dev_get(dev);
361         if (!mdev)
362                 goto drop;
363 
364         MPLS_INC_STATS_LEN(mdev, skb->len, rx_packets,
365                            rx_bytes);
366 
367         if (!mdev->input_enabled) {
368                 MPLS_INC_STATS(mdev, rx_dropped);
369                 goto drop;
370         }
371 
372         if (skb->pkt_type != PACKET_HOST)
373                 goto err;
374 
375         if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
376                 goto err;
377 
378         if (!pskb_may_pull(skb, sizeof(*hdr)))
379                 goto err;
380 
381         /* Read and decode the label */
382         hdr = mpls_hdr(skb);
383         dec = mpls_entry_decode(hdr);
384 
385         rt = mpls_route_input_rcu(net, dec.label);
386         if (!rt) {
387                 MPLS_INC_STATS(mdev, rx_noroute);
388                 goto drop;
389         }
390 
391         nh = mpls_select_multipath(rt, skb);
392         if (!nh)
393                 goto err;
394 
395         /* Pop the label */
396         skb_pull(skb, sizeof(*hdr));
397         skb_reset_network_header(skb);
398 
399         skb_orphan(skb);
400 
401         if (skb_warn_if_lro(skb))
402                 goto err;
403 
404         skb_forward_csum(skb);
405 
406         /* Verify ttl is valid */
407         if (dec.ttl <= 1)
408                 goto err;
409         dec.ttl -= 1;
410 
411         /* Find the output device */
412         out_dev = rcu_dereference(nh->nh_dev);
413         if (!mpls_output_possible(out_dev))
414                 goto tx_err;
415 
416         /* Verify the destination can hold the packet */
417         new_header_size = mpls_nh_header_size(nh);
418         mtu = mpls_dev_mtu(out_dev);
419         if (mpls_pkt_too_big(skb, mtu - new_header_size))
420                 goto tx_err;
421 
422         hh_len = LL_RESERVED_SPACE(out_dev);
423         if (!out_dev->header_ops)
424                 hh_len = 0;
425 
426         /* Ensure there is enough space for the headers in the skb */
427         if (skb_cow(skb, hh_len + new_header_size))
428                 goto tx_err;
429 
430         skb->dev = out_dev;
431         skb->protocol = htons(ETH_P_MPLS_UC);
432 
433         if (unlikely(!new_header_size && dec.bos)) {
434                 /* Penultimate hop popping */
435                 if (!mpls_egress(dev_net(out_dev), rt, skb, dec))
436                         goto err;
437         } else {
438                 bool bos;
439                 int i;
440                 skb_push(skb, new_header_size);
441                 skb_reset_network_header(skb);
442                 /* Push the new labels */
443                 hdr = mpls_hdr(skb);
444                 bos = dec.bos;
445                 for (i = nh->nh_labels - 1; i >= 0; i--) {
446                         hdr[i] = mpls_entry_encode(nh->nh_label[i],
447                                                    dec.ttl, 0, bos);
448                         bos = false;
449                 }
450         }
451 
452         mpls_stats_inc_outucastpkts(out_dev, skb);
453 
454         /* If via wasn't specified then send out using device address */
455         if (nh->nh_via_table == MPLS_NEIGH_TABLE_UNSPEC)
456                 err = neigh_xmit(NEIGH_LINK_TABLE, out_dev,
457                                  out_dev->dev_addr, skb);
458         else
459                 err = neigh_xmit(nh->nh_via_table, out_dev,
460                                  mpls_nh_via(rt, nh), skb);
461         if (err)
462                 net_dbg_ratelimited("%s: packet transmission failed: %d\n",
463                                     __func__, err);
464         return 0;
465 
466 tx_err:
467         out_mdev = out_dev ? mpls_dev_get(out_dev) : NULL;
468         if (out_mdev)
469                 MPLS_INC_STATS(out_mdev, tx_errors);
470         goto drop;
471 err:
472         MPLS_INC_STATS(mdev, rx_errors);
473 drop:
474         kfree_skb(skb);
475         return NET_RX_DROP;
476 }
477 
478 static struct packet_type mpls_packet_type __read_mostly = {
479         .type = cpu_to_be16(ETH_P_MPLS_UC),
480         .func = mpls_forward,
481 };
482 
483 static const struct nla_policy rtm_mpls_policy[RTA_MAX+1] = {
484         [RTA_DST]               = { .type = NLA_U32 },
485         [RTA_OIF]               = { .type = NLA_U32 },
486         [RTA_TTL_PROPAGATE]     = { .type = NLA_U8 },
487 };
488 
489 struct mpls_route_config {
490         u32                     rc_protocol;
491         u32                     rc_ifindex;
492         u8                      rc_via_table;
493         u8                      rc_via_alen;
494         u8                      rc_via[MAX_VIA_ALEN];
495         u32                     rc_label;
496         u8                      rc_ttl_propagate;
497         u8                      rc_output_labels;
498         u32                     rc_output_label[MAX_NEW_LABELS];
499         u32                     rc_nlflags;
500         enum mpls_payload_type  rc_payload_type;
501         struct nl_info          rc_nlinfo;
502         struct rtnexthop        *rc_mp;
503         int                     rc_mp_len;
504 };
505 
506 /* all nexthops within a route have the same size based on max
507  * number of labels and max via length for a hop
508  */
509 static struct mpls_route *mpls_rt_alloc(u8 num_nh, u8 max_alen, u8 max_labels)
510 {
511         u8 nh_size = MPLS_NH_SIZE(max_labels, max_alen);
512         struct mpls_route *rt;
513         size_t size;
514 
515         size = sizeof(*rt) + num_nh * nh_size;
516         if (size > MAX_MPLS_ROUTE_MEM)
517                 return ERR_PTR(-EINVAL);
518 
519         rt = kzalloc(size, GFP_KERNEL);
520         if (!rt)
521                 return ERR_PTR(-ENOMEM);
522 
523         rt->rt_nhn = num_nh;
524         rt->rt_nhn_alive = num_nh;
525         rt->rt_nh_size = nh_size;
526         rt->rt_via_offset = MPLS_NH_VIA_OFF(max_labels);
527 
528         return rt;
529 }
530 
531 static void mpls_rt_free(struct mpls_route *rt)
532 {
533         if (rt)
534                 kfree_rcu(rt, rt_rcu);
535 }
536 
537 static void mpls_notify_route(struct net *net, unsigned index,
538                               struct mpls_route *old, struct mpls_route *new,
539                               const struct nl_info *info)
540 {
541         struct nlmsghdr *nlh = info ? info->nlh : NULL;
542         unsigned portid = info ? info->portid : 0;
543         int event = new ? RTM_NEWROUTE : RTM_DELROUTE;
544         struct mpls_route *rt = new ? new : old;
545         unsigned nlm_flags = (old && new) ? NLM_F_REPLACE : 0;
546         /* Ignore reserved labels for now */
547         if (rt && (index >= MPLS_LABEL_FIRST_UNRESERVED))
548                 rtmsg_lfib(event, index, rt, nlh, net, portid, nlm_flags);
549 }
550 
551 static void mpls_route_update(struct net *net, unsigned index,
552                               struct mpls_route *new,
553                               const struct nl_info *info)
554 {
555         struct mpls_route __rcu **platform_label;
556         struct mpls_route *rt;
557 
558         ASSERT_RTNL();
559 
560         platform_label = rtnl_dereference(net->mpls.platform_label);
561         rt = rtnl_dereference(platform_label[index]);
562         rcu_assign_pointer(platform_label[index], new);
563 
564         mpls_notify_route(net, index, rt, new, info);
565 
566         /* If we removed a route free it now */
567         mpls_rt_free(rt);
568 }
569 
570 static unsigned find_free_label(struct net *net)
571 {
572         struct mpls_route __rcu **platform_label;
573         size_t platform_labels;
574         unsigned index;
575 
576         platform_label = rtnl_dereference(net->mpls.platform_label);
577         platform_labels = net->mpls.platform_labels;
578         for (index = MPLS_LABEL_FIRST_UNRESERVED; index < platform_labels;
579              index++) {
580                 if (!rtnl_dereference(platform_label[index]))
581                         return index;
582         }
583         return LABEL_NOT_SPECIFIED;
584 }
585 
586 #if IS_ENABLED(CONFIG_INET)
587 static struct net_device *inet_fib_lookup_dev(struct net *net,
588                                               const void *addr)
589 {
590         struct net_device *dev;
591         struct rtable *rt;
592         struct in_addr daddr;
593 
594         memcpy(&daddr, addr, sizeof(struct in_addr));
595         rt = ip_route_output(net, daddr.s_addr, 0, 0, 0);
596         if (IS_ERR(rt))
597                 return ERR_CAST(rt);
598 
599         dev = rt->dst.dev;
600         dev_hold(dev);
601 
602         ip_rt_put(rt);
603 
604         return dev;
605 }
606 #else
607 static struct net_device *inet_fib_lookup_dev(struct net *net,
608                                               const void *addr)
609 {
610         return ERR_PTR(-EAFNOSUPPORT);
611 }
612 #endif
613 
614 #if IS_ENABLED(CONFIG_IPV6)
615 static struct net_device *inet6_fib_lookup_dev(struct net *net,
616                                                const void *addr)
617 {
618         struct net_device *dev;
619         struct dst_entry *dst;
620         struct flowi6 fl6;
621         int err;
622 
623         if (!ipv6_stub)
624                 return ERR_PTR(-EAFNOSUPPORT);
625 
626         memset(&fl6, 0, sizeof(fl6));
627         memcpy(&fl6.daddr, addr, sizeof(struct in6_addr));
628         err = ipv6_stub->ipv6_dst_lookup(net, NULL, &dst, &fl6);
629         if (err)
630                 return ERR_PTR(err);
631 
632         dev = dst->dev;
633         dev_hold(dev);
634         dst_release(dst);
635 
636         return dev;
637 }
638 #else
639 static struct net_device *inet6_fib_lookup_dev(struct net *net,
640                                                const void *addr)
641 {
642         return ERR_PTR(-EAFNOSUPPORT);
643 }
644 #endif
645 
646 static struct net_device *find_outdev(struct net *net,
647                                       struct mpls_route *rt,
648                                       struct mpls_nh *nh, int oif)
649 {
650         struct net_device *dev = NULL;
651 
652         if (!oif) {
653                 switch (nh->nh_via_table) {
654                 case NEIGH_ARP_TABLE:
655                         dev = inet_fib_lookup_dev(net, mpls_nh_via(rt, nh));
656                         break;
657                 case NEIGH_ND_TABLE:
658                         dev = inet6_fib_lookup_dev(net, mpls_nh_via(rt, nh));
659                         break;
660                 case NEIGH_LINK_TABLE:
661                         break;
662                 }
663         } else {
664                 dev = dev_get_by_index(net, oif);
665         }
666 
667         if (!dev)
668                 return ERR_PTR(-ENODEV);
669 
670         if (IS_ERR(dev))
671                 return dev;
672 
673         /* The caller is holding rtnl anyways, so release the dev reference */
674         dev_put(dev);
675 
676         return dev;
677 }
678 
679 static int mpls_nh_assign_dev(struct net *net, struct mpls_route *rt,
680                               struct mpls_nh *nh, int oif)
681 {
682         struct net_device *dev = NULL;
683         int err = -ENODEV;
684 
685         dev = find_outdev(net, rt, nh, oif);
686         if (IS_ERR(dev)) {
687                 err = PTR_ERR(dev);
688                 dev = NULL;
689                 goto errout;
690         }
691 
692         /* Ensure this is a supported device */
693         err = -EINVAL;
694         if (!mpls_dev_get(dev))
695                 goto errout;
696 
697         if ((nh->nh_via_table == NEIGH_LINK_TABLE) &&
698             (dev->addr_len != nh->nh_via_alen))
699                 goto errout;
700 
701         RCU_INIT_POINTER(nh->nh_dev, dev);
702 
703         if (!(dev->flags & IFF_UP)) {
704                 nh->nh_flags |= RTNH_F_DEAD;
705         } else {
706                 unsigned int flags;
707 
708                 flags = dev_get_flags(dev);
709                 if (!(flags & (IFF_RUNNING | IFF_LOWER_UP)))
710                         nh->nh_flags |= RTNH_F_LINKDOWN;
711         }
712 
713         return 0;
714 
715 errout:
716         return err;
717 }
718 
719 static int nla_get_via(const struct nlattr *nla, u8 *via_alen, u8 *via_table,
720                        u8 via_addr[], struct netlink_ext_ack *extack)
721 {
722         struct rtvia *via = nla_data(nla);
723         int err = -EINVAL;
724         int alen;
725 
726         if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) {
727                 NL_SET_ERR_MSG_ATTR(extack, nla,
728                                     "Invalid attribute length for RTA_VIA");
729                 goto errout;
730         }
731         alen = nla_len(nla) -
732                         offsetof(struct rtvia, rtvia_addr);
733         if (alen > MAX_VIA_ALEN) {
734                 NL_SET_ERR_MSG_ATTR(extack, nla,
735                                     "Invalid address length for RTA_VIA");
736                 goto errout;
737         }
738 
739         /* Validate the address family */
740         switch (via->rtvia_family) {
741         case AF_PACKET:
742                 *via_table = NEIGH_LINK_TABLE;
743                 break;
744         case AF_INET:
745                 *via_table = NEIGH_ARP_TABLE;
746                 if (alen != 4)
747                         goto errout;
748                 break;
749         case AF_INET6:
750                 *via_table = NEIGH_ND_TABLE;
751                 if (alen != 16)
752                         goto errout;
753                 break;
754         default:
755                 /* Unsupported address family */
756                 goto errout;
757         }
758 
759         memcpy(via_addr, via->rtvia_addr, alen);
760         *via_alen = alen;
761         err = 0;
762 
763 errout:
764         return err;
765 }
766 
767 static int mpls_nh_build_from_cfg(struct mpls_route_config *cfg,
768                                   struct mpls_route *rt)
769 {
770         struct net *net = cfg->rc_nlinfo.nl_net;
771         struct mpls_nh *nh = rt->rt_nh;
772         int err;
773         int i;
774 
775         if (!nh)
776                 return -ENOMEM;
777 
778         nh->nh_labels = cfg->rc_output_labels;
779         for (i = 0; i < nh->nh_labels; i++)
780                 nh->nh_label[i] = cfg->rc_output_label[i];
781 
782         nh->nh_via_table = cfg->rc_via_table;
783         memcpy(__mpls_nh_via(rt, nh), cfg->rc_via, cfg->rc_via_alen);
784         nh->nh_via_alen = cfg->rc_via_alen;
785 
786         err = mpls_nh_assign_dev(net, rt, nh, cfg->rc_ifindex);
787         if (err)
788                 goto errout;
789 
790         if (nh->nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN))
791                 rt->rt_nhn_alive--;
792 
793         return 0;
794 
795 errout:
796         return err;
797 }
798 
799 static int mpls_nh_build(struct net *net, struct mpls_route *rt,
800                          struct mpls_nh *nh, int oif, struct nlattr *via,
801                          struct nlattr *newdst, u8 max_labels,
802                          struct netlink_ext_ack *extack)
803 {
804         int err = -ENOMEM;
805 
806         if (!nh)
807                 goto errout;
808 
809         if (newdst) {
810                 err = nla_get_labels(newdst, max_labels, &nh->nh_labels,
811                                      nh->nh_label, extack);
812                 if (err)
813                         goto errout;
814         }
815 
816         if (via) {
817                 err = nla_get_via(via, &nh->nh_via_alen, &nh->nh_via_table,
818                                   __mpls_nh_via(rt, nh), extack);
819                 if (err)
820                         goto errout;
821         } else {
822                 nh->nh_via_table = MPLS_NEIGH_TABLE_UNSPEC;
823         }
824 
825         err = mpls_nh_assign_dev(net, rt, nh, oif);
826         if (err)
827                 goto errout;
828 
829         return 0;
830 
831 errout:
832         return err;
833 }
834 
835 static u8 mpls_count_nexthops(struct rtnexthop *rtnh, int len,
836                               u8 cfg_via_alen, u8 *max_via_alen,
837                               u8 *max_labels)
838 {
839         int remaining = len;
840         u8 nhs = 0;
841 
842         *max_via_alen = 0;
843         *max_labels = 0;
844 
845         while (rtnh_ok(rtnh, remaining)) {
846                 struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
847                 int attrlen;
848                 u8 n_labels = 0;
849 
850                 attrlen = rtnh_attrlen(rtnh);
851                 nla = nla_find(attrs, attrlen, RTA_VIA);
852                 if (nla && nla_len(nla) >=
853                     offsetof(struct rtvia, rtvia_addr)) {
854                         int via_alen = nla_len(nla) -
855                                 offsetof(struct rtvia, rtvia_addr);
856 
857                         if (via_alen <= MAX_VIA_ALEN)
858                                 *max_via_alen = max_t(u16, *max_via_alen,
859                                                       via_alen);
860                 }
861 
862                 nla = nla_find(attrs, attrlen, RTA_NEWDST);
863                 if (nla &&
864                     nla_get_labels(nla, MAX_NEW_LABELS, &n_labels,
865                                    NULL, NULL) != 0)
866                         return 0;
867 
868                 *max_labels = max_t(u8, *max_labels, n_labels);
869 
870                 /* number of nexthops is tracked by a u8.
871                  * Check for overflow.
872                  */
873                 if (nhs == 255)
874                         return 0;
875                 nhs++;
876 
877                 rtnh = rtnh_next(rtnh, &remaining);
878         }
879 
880         /* leftover implies invalid nexthop configuration, discard it */
881         return remaining > 0 ? 0 : nhs;
882 }
883 
884 static int mpls_nh_build_multi(struct mpls_route_config *cfg,
885                                struct mpls_route *rt, u8 max_labels,
886                                struct netlink_ext_ack *extack)
887 {
888         struct rtnexthop *rtnh = cfg->rc_mp;
889         struct nlattr *nla_via, *nla_newdst;
890         int remaining = cfg->rc_mp_len;
891         int err = 0;
892         u8 nhs = 0;
893 
894         change_nexthops(rt) {
895                 int attrlen;
896 
897                 nla_via = NULL;
898                 nla_newdst = NULL;
899 
900                 err = -EINVAL;
901                 if (!rtnh_ok(rtnh, remaining))
902                         goto errout;
903 
904                 /* neither weighted multipath nor any flags
905                  * are supported
906                  */
907                 if (rtnh->rtnh_hops || rtnh->rtnh_flags)
908                         goto errout;
909 
910                 attrlen = rtnh_attrlen(rtnh);
911                 if (attrlen > 0) {
912                         struct nlattr *attrs = rtnh_attrs(rtnh);
913 
914                         nla_via = nla_find(attrs, attrlen, RTA_VIA);
915                         nla_newdst = nla_find(attrs, attrlen, RTA_NEWDST);
916                 }
917 
918                 err = mpls_nh_build(cfg->rc_nlinfo.nl_net, rt, nh,
919                                     rtnh->rtnh_ifindex, nla_via, nla_newdst,
920                                     max_labels, extack);
921                 if (err)
922                         goto errout;
923 
924                 if (nh->nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN))
925                         rt->rt_nhn_alive--;
926 
927                 rtnh = rtnh_next(rtnh, &remaining);
928                 nhs++;
929         } endfor_nexthops(rt);
930 
931         rt->rt_nhn = nhs;
932 
933         return 0;
934 
935 errout:
936         return err;
937 }
938 
939 static bool mpls_label_ok(struct net *net, unsigned int *index,
940                           struct netlink_ext_ack *extack)
941 {
942         bool is_ok = true;
943 
944         /* Reserved labels may not be set */
945         if (*index < MPLS_LABEL_FIRST_UNRESERVED) {
946                 NL_SET_ERR_MSG(extack,
947                                "Invalid label - must be MPLS_LABEL_FIRST_UNRESERVED or higher");
948                 is_ok = false;
949         }
950 
951         /* The full 20 bit range may not be supported. */
952         if (is_ok && *index >= net->mpls.platform_labels) {
953                 NL_SET_ERR_MSG(extack,
954                                "Label >= configured maximum in platform_labels");
955                 is_ok = false;
956         }
957 
958         *index = array_index_nospec(*index, net->mpls.platform_labels);
959         return is_ok;
960 }
961 
962 static int mpls_route_add(struct mpls_route_config *cfg,
963                           struct netlink_ext_ack *extack)
964 {
965         struct mpls_route __rcu **platform_label;
966         struct net *net = cfg->rc_nlinfo.nl_net;
967         struct mpls_route *rt, *old;
968         int err = -EINVAL;
969         u8 max_via_alen;
970         unsigned index;
971         u8 max_labels;
972         u8 nhs;
973 
974         index = cfg->rc_label;
975 
976         /* If a label was not specified during insert pick one */
977         if ((index == LABEL_NOT_SPECIFIED) &&
978             (cfg->rc_nlflags & NLM_F_CREATE)) {
979                 index = find_free_label(net);
980         }
981 
982         if (!mpls_label_ok(net, &index, extack))
983                 goto errout;
984 
985         /* Append makes no sense with mpls */
986         err = -EOPNOTSUPP;
987         if (cfg->rc_nlflags & NLM_F_APPEND) {
988                 NL_SET_ERR_MSG(extack, "MPLS does not support route append");
989                 goto errout;
990         }
991 
992         err = -EEXIST;
993         platform_label = rtnl_dereference(net->mpls.platform_label);
994         old = rtnl_dereference(platform_label[index]);
995         if ((cfg->rc_nlflags & NLM_F_EXCL) && old)
996                 goto errout;
997 
998         err = -EEXIST;
999         if (!(cfg->rc_nlflags & NLM_F_REPLACE) && old)
1000                 goto errout;
1001 
1002         err = -ENOENT;
1003         if (!(cfg->rc_nlflags & NLM_F_CREATE) && !old)
1004                 goto errout;
1005 
1006         err = -EINVAL;
1007         if (cfg->rc_mp) {
1008                 nhs = mpls_count_nexthops(cfg->rc_mp, cfg->rc_mp_len,
1009                                           cfg->rc_via_alen, &max_via_alen,
1010                                           &max_labels);
1011         } else {
1012                 max_via_alen = cfg->rc_via_alen;
1013                 max_labels = cfg->rc_output_labels;
1014                 nhs = 1;
1015         }
1016 
1017         if (nhs == 0) {
1018                 NL_SET_ERR_MSG(extack, "Route does not contain a nexthop");
1019                 goto errout;
1020         }
1021 
1022         err = -ENOMEM;
1023         rt = mpls_rt_alloc(nhs, max_via_alen, max_labels);
1024         if (IS_ERR(rt)) {
1025                 err = PTR_ERR(rt);
1026                 goto errout;
1027         }
1028 
1029         rt->rt_protocol = cfg->rc_protocol;
1030         rt->rt_payload_type = cfg->rc_payload_type;
1031         rt->rt_ttl_propagate = cfg->rc_ttl_propagate;
1032 
1033         if (cfg->rc_mp)
1034                 err = mpls_nh_build_multi(cfg, rt, max_labels, extack);
1035         else
1036                 err = mpls_nh_build_from_cfg(cfg, rt);
1037         if (err)
1038                 goto freert;
1039 
1040         mpls_route_update(net, index, rt, &cfg->rc_nlinfo);
1041 
1042         return 0;
1043 
1044 freert:
1045         mpls_rt_free(rt);
1046 errout:
1047         return err;
1048 }
1049 
1050 static int mpls_route_del(struct mpls_route_config *cfg,
1051                           struct netlink_ext_ack *extack)
1052 {
1053         struct net *net = cfg->rc_nlinfo.nl_net;
1054         unsigned index;
1055         int err = -EINVAL;
1056 
1057         index = cfg->rc_label;
1058 
1059         if (!mpls_label_ok(net, &index, extack))
1060                 goto errout;
1061 
1062         mpls_route_update(net, index, NULL, &cfg->rc_nlinfo);
1063 
1064         err = 0;
1065 errout:
1066         return err;
1067 }
1068 
1069 static void mpls_get_stats(struct mpls_dev *mdev,
1070                            struct mpls_link_stats *stats)
1071 {
1072         struct mpls_pcpu_stats *p;
1073         int i;
1074 
1075         memset(stats, 0, sizeof(*stats));
1076 
1077         for_each_possible_cpu(i) {
1078                 struct mpls_link_stats local;
1079                 unsigned int start;
1080 
1081                 p = per_cpu_ptr(mdev->stats, i);
1082                 do {
1083                         start = u64_stats_fetch_begin(&p->syncp);
1084                         local = p->stats;
1085                 } while (u64_stats_fetch_retry(&p->syncp, start));
1086 
1087                 stats->rx_packets       += local.rx_packets;
1088                 stats->rx_bytes         += local.rx_bytes;
1089                 stats->tx_packets       += local.tx_packets;
1090                 stats->tx_bytes         += local.tx_bytes;
1091                 stats->rx_errors        += local.rx_errors;
1092                 stats->tx_errors        += local.tx_errors;
1093                 stats->rx_dropped       += local.rx_dropped;
1094                 stats->tx_dropped       += local.tx_dropped;
1095                 stats->rx_noroute       += local.rx_noroute;
1096         }
1097 }
1098 
1099 static int mpls_fill_stats_af(struct sk_buff *skb,
1100                               const struct net_device *dev)
1101 {
1102         struct mpls_link_stats *stats;
1103         struct mpls_dev *mdev;
1104         struct nlattr *nla;
1105 
1106         mdev = mpls_dev_get(dev);
1107         if (!mdev)
1108                 return -ENODATA;
1109 
1110         nla = nla_reserve_64bit(skb, MPLS_STATS_LINK,
1111                                 sizeof(struct mpls_link_stats),
1112                                 MPLS_STATS_UNSPEC);
1113         if (!nla)
1114                 return -EMSGSIZE;
1115 
1116         stats = nla_data(nla);
1117         mpls_get_stats(mdev, stats);
1118 
1119         return 0;
1120 }
1121 
1122 static size_t mpls_get_stats_af_size(const struct net_device *dev)
1123 {
1124         struct mpls_dev *mdev;
1125 
1126         mdev = mpls_dev_get(dev);
1127         if (!mdev)
1128                 return 0;
1129 
1130         return nla_total_size_64bit(sizeof(struct mpls_link_stats));
1131 }
1132 
1133 static int mpls_netconf_fill_devconf(struct sk_buff *skb, struct mpls_dev *mdev,
1134                                      u32 portid, u32 seq, int event,
1135                                      unsigned int flags, int type)
1136 {
1137         struct nlmsghdr  *nlh;
1138         struct netconfmsg *ncm;
1139         bool all = false;
1140 
1141         nlh = nlmsg_put(skb, portid, seq, event, sizeof(struct netconfmsg),
1142                         flags);
1143         if (!nlh)
1144                 return -EMSGSIZE;
1145 
1146         if (type == NETCONFA_ALL)
1147                 all = true;
1148 
1149         ncm = nlmsg_data(nlh);
1150         ncm->ncm_family = AF_MPLS;
1151 
1152         if (nla_put_s32(skb, NETCONFA_IFINDEX, mdev->dev->ifindex) < 0)
1153                 goto nla_put_failure;
1154 
1155         if ((all || type == NETCONFA_INPUT) &&
1156             nla_put_s32(skb, NETCONFA_INPUT,
1157                         mdev->input_enabled) < 0)
1158                 goto nla_put_failure;
1159 
1160         nlmsg_end(skb, nlh);
1161         return 0;
1162 
1163 nla_put_failure:
1164         nlmsg_cancel(skb, nlh);
1165         return -EMSGSIZE;
1166 }
1167 
1168 static int mpls_netconf_msgsize_devconf(int type)
1169 {
1170         int size = NLMSG_ALIGN(sizeof(struct netconfmsg))
1171                         + nla_total_size(4); /* NETCONFA_IFINDEX */
1172         bool all = false;
1173 
1174         if (type == NETCONFA_ALL)
1175                 all = true;
1176 
1177         if (all || type == NETCONFA_INPUT)
1178                 size += nla_total_size(4);
1179 
1180         return size;
1181 }
1182 
1183 static void mpls_netconf_notify_devconf(struct net *net, int event,
1184                                         int type, struct mpls_dev *mdev)
1185 {
1186         struct sk_buff *skb;
1187         int err = -ENOBUFS;
1188 
1189         skb = nlmsg_new(mpls_netconf_msgsize_devconf(type), GFP_KERNEL);
1190         if (!skb)
1191                 goto errout;
1192 
1193         err = mpls_netconf_fill_devconf(skb, mdev, 0, 0, event, 0, type);
1194         if (err < 0) {
1195                 /* -EMSGSIZE implies BUG in mpls_netconf_msgsize_devconf() */
1196                 WARN_ON(err == -EMSGSIZE);
1197                 kfree_skb(skb);
1198                 goto errout;
1199         }
1200 
1201         rtnl_notify(skb, net, 0, RTNLGRP_MPLS_NETCONF, NULL, GFP_KERNEL);
1202         return;
1203 errout:
1204         if (err < 0)
1205                 rtnl_set_sk_err(net, RTNLGRP_MPLS_NETCONF, err);
1206 }
1207 
1208 static const struct nla_policy devconf_mpls_policy[NETCONFA_MAX + 1] = {
1209         [NETCONFA_IFINDEX]      = { .len = sizeof(int) },
1210 };
1211 
1212 static int mpls_netconf_get_devconf(struct sk_buff *in_skb,
1213                                     struct nlmsghdr *nlh,
1214                                     struct netlink_ext_ack *extack)
1215 {
1216         struct net *net = sock_net(in_skb->sk);
1217         struct nlattr *tb[NETCONFA_MAX + 1];
1218         struct netconfmsg *ncm;
1219         struct net_device *dev;
1220         struct mpls_dev *mdev;
1221         struct sk_buff *skb;
1222         int ifindex;
1223         int err;
1224 
1225         err = nlmsg_parse(nlh, sizeof(*ncm), tb, NETCONFA_MAX,
1226                           devconf_mpls_policy, NULL);
1227         if (err < 0)
1228                 goto errout;
1229 
1230         err = -EINVAL;
1231         if (!tb[NETCONFA_IFINDEX])
1232                 goto errout;
1233 
1234         ifindex = nla_get_s32(tb[NETCONFA_IFINDEX]);
1235         dev = __dev_get_by_index(net, ifindex);
1236         if (!dev)
1237                 goto errout;
1238 
1239         mdev = mpls_dev_get(dev);
1240         if (!mdev)
1241                 goto errout;
1242 
1243         err = -ENOBUFS;
1244         skb = nlmsg_new(mpls_netconf_msgsize_devconf(NETCONFA_ALL), GFP_KERNEL);
1245         if (!skb)
1246                 goto errout;
1247 
1248         err = mpls_netconf_fill_devconf(skb, mdev,
1249                                         NETLINK_CB(in_skb).portid,
1250                                         nlh->nlmsg_seq, RTM_NEWNETCONF, 0,
1251                                         NETCONFA_ALL);
1252         if (err < 0) {
1253                 /* -EMSGSIZE implies BUG in mpls_netconf_msgsize_devconf() */
1254                 WARN_ON(err == -EMSGSIZE);
1255                 kfree_skb(skb);
1256                 goto errout;
1257         }
1258         err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
1259 errout:
1260         return err;
1261 }
1262 
1263 static int mpls_netconf_dump_devconf(struct sk_buff *skb,
1264                                      struct netlink_callback *cb)
1265 {
1266         struct net *net = sock_net(skb->sk);
1267         struct hlist_head *head;
1268         struct net_device *dev;
1269         struct mpls_dev *mdev;
1270         int idx, s_idx;
1271         int h, s_h;
1272 
1273         s_h = cb->args[0];
1274         s_idx = idx = cb->args[1];
1275 
1276         for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {
1277                 idx = 0;
1278                 head = &net->dev_index_head[h];
1279                 rcu_read_lock();
1280                 cb->seq = net->dev_base_seq;
1281                 hlist_for_each_entry_rcu(dev, head, index_hlist) {
1282                         if (idx < s_idx)
1283                                 goto cont;
1284                         mdev = mpls_dev_get(dev);
1285                         if (!mdev)
1286                                 goto cont;
1287                         if (mpls_netconf_fill_devconf(skb, mdev,
1288                                                       NETLINK_CB(cb->skb).portid,
1289                                                       cb->nlh->nlmsg_seq,
1290                                                       RTM_NEWNETCONF,
1291                                                       NLM_F_MULTI,
1292                                                       NETCONFA_ALL) < 0) {
1293                                 rcu_read_unlock();
1294                                 goto done;
1295                         }
1296                         nl_dump_check_consistent(cb, nlmsg_hdr(skb));
1297 cont:
1298                         idx++;
1299                 }
1300                 rcu_read_unlock();
1301         }
1302 done:
1303         cb->args[0] = h;
1304         cb->args[1] = idx;
1305 
1306         return skb->len;
1307 }
1308 
1309 #define MPLS_PERDEV_SYSCTL_OFFSET(field)        \
1310         (&((struct mpls_dev *)0)->field)
1311 
1312 static int mpls_conf_proc(struct ctl_table *ctl, int write,
1313                           void __user *buffer,
1314                           size_t *lenp, loff_t *ppos)
1315 {
1316         int oval = *(int *)ctl->data;
1317         int ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
1318 
1319         if (write) {
1320                 struct mpls_dev *mdev = ctl->extra1;
1321                 int i = (int *)ctl->data - (int *)mdev;
1322                 struct net *net = ctl->extra2;
1323                 int val = *(int *)ctl->data;
1324 
1325                 if (i == offsetof(struct mpls_dev, input_enabled) &&
1326                     val != oval) {
1327                         mpls_netconf_notify_devconf(net, RTM_NEWNETCONF,
1328                                                     NETCONFA_INPUT, mdev);
1329                 }
1330         }
1331 
1332         return ret;
1333 }
1334 
1335 static const struct ctl_table mpls_dev_table[] = {
1336         {
1337                 .procname       = "input",
1338                 .maxlen         = sizeof(int),
1339                 .mode           = 0644,
1340                 .proc_handler   = mpls_conf_proc,
1341                 .data           = MPLS_PERDEV_SYSCTL_OFFSET(input_enabled),
1342         },
1343         { }
1344 };
1345 
1346 static int mpls_dev_sysctl_register(struct net_device *dev,
1347                                     struct mpls_dev *mdev)
1348 {
1349         char path[sizeof("net/mpls/conf/") + IFNAMSIZ];
1350         struct net *net = dev_net(dev);
1351         struct ctl_table *table;
1352         int i;
1353 
1354         table = kmemdup(&mpls_dev_table, sizeof(mpls_dev_table), GFP_KERNEL);
1355         if (!table)
1356                 goto out;
1357 
1358         /* Table data contains only offsets relative to the base of
1359          * the mdev at this point, so make them absolute.
1360          */
1361         for (i = 0; i < ARRAY_SIZE(mpls_dev_table); i++) {
1362                 table[i].data = (char *)mdev + (uintptr_t)table[i].data;
1363                 table[i].extra1 = mdev;
1364                 table[i].extra2 = net;
1365         }
1366 
1367         snprintf(path, sizeof(path), "net/mpls/conf/%s", dev->name);
1368 
1369         mdev->sysctl = register_net_sysctl(net, path, table);
1370         if (!mdev->sysctl)
1371                 goto free;
1372 
1373         mpls_netconf_notify_devconf(net, RTM_NEWNETCONF, NETCONFA_ALL, mdev);
1374         return 0;
1375 
1376 free:
1377         kfree(table);
1378 out:
1379         return -ENOBUFS;
1380 }
1381 
1382 static void mpls_dev_sysctl_unregister(struct net_device *dev,
1383                                        struct mpls_dev *mdev)
1384 {
1385         struct net *net = dev_net(dev);
1386         struct ctl_table *table;
1387 
1388         table = mdev->sysctl->ctl_table_arg;
1389         unregister_net_sysctl_table(mdev->sysctl);
1390         kfree(table);
1391 
1392         mpls_netconf_notify_devconf(net, RTM_DELNETCONF, 0, mdev);
1393 }
1394 
1395 static struct mpls_dev *mpls_add_dev(struct net_device *dev)
1396 {
1397         struct mpls_dev *mdev;
1398         int err = -ENOMEM;
1399         int i;
1400 
1401         ASSERT_RTNL();
1402 
1403         mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
1404         if (!mdev)
1405                 return ERR_PTR(err);
1406 
1407         mdev->stats = alloc_percpu(struct mpls_pcpu_stats);
1408         if (!mdev->stats)
1409                 goto free;
1410 
1411         for_each_possible_cpu(i) {
1412                 struct mpls_pcpu_stats *mpls_stats;
1413 
1414                 mpls_stats = per_cpu_ptr(mdev->stats, i);
1415                 u64_stats_init(&mpls_stats->syncp);
1416         }
1417 
1418         mdev->dev = dev;
1419 
1420         err = mpls_dev_sysctl_register(dev, mdev);
1421         if (err)
1422                 goto free;
1423 
1424         rcu_assign_pointer(dev->mpls_ptr, mdev);
1425 
1426         return mdev;
1427 
1428 free:
1429         free_percpu(mdev->stats);
1430         kfree(mdev);
1431         return ERR_PTR(err);
1432 }
1433 
1434 static void mpls_dev_destroy_rcu(struct rcu_head *head)
1435 {
1436         struct mpls_dev *mdev = container_of(head, struct mpls_dev, rcu);
1437 
1438         free_percpu(mdev->stats);
1439         kfree(mdev);
1440 }
1441 
1442 static void mpls_ifdown(struct net_device *dev, int event)
1443 {
1444         struct mpls_route __rcu **platform_label;
1445         struct net *net = dev_net(dev);
1446         u8 alive, deleted;
1447         unsigned index;
1448 
1449         platform_label = rtnl_dereference(net->mpls.platform_label);
1450         for (index = 0; index < net->mpls.platform_labels; index++) {
1451                 struct mpls_route *rt = rtnl_dereference(platform_label[index]);
1452 
1453                 if (!rt)
1454                         continue;
1455 
1456                 alive = 0;
1457                 deleted = 0;
1458                 change_nexthops(rt) {
1459                         unsigned int nh_flags = nh->nh_flags;
1460 
1461                         if (rtnl_dereference(nh->nh_dev) != dev)
1462                                 goto next;
1463 
1464                         switch (event) {
1465                         case NETDEV_DOWN:
1466                         case NETDEV_UNREGISTER:
1467                                 nh_flags |= RTNH_F_DEAD;
1468                                 /* fall through */
1469                         case NETDEV_CHANGE:
1470                                 nh_flags |= RTNH_F_LINKDOWN;
1471                                 break;
1472                         }
1473                         if (event == NETDEV_UNREGISTER)
1474                                 RCU_INIT_POINTER(nh->nh_dev, NULL);
1475 
1476                         if (nh->nh_flags != nh_flags)
1477                                 WRITE_ONCE(nh->nh_flags, nh_flags);
1478 next:
1479                         if (!(nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)))
1480                                 alive++;
1481                         if (!rtnl_dereference(nh->nh_dev))
1482                                 deleted++;
1483                 } endfor_nexthops(rt);
1484 
1485                 WRITE_ONCE(rt->rt_nhn_alive, alive);
1486 
1487                 /* if there are no more nexthops, delete the route */
1488                 if (event == NETDEV_UNREGISTER && deleted == rt->rt_nhn)
1489                         mpls_route_update(net, index, NULL, NULL);
1490         }
1491 }
1492 
1493 static void mpls_ifup(struct net_device *dev, unsigned int flags)
1494 {
1495         struct mpls_route __rcu **platform_label;
1496         struct net *net = dev_net(dev);
1497         unsigned index;
1498         u8 alive;
1499 
1500         platform_label = rtnl_dereference(net->mpls.platform_label);
1501         for (index = 0; index < net->mpls.platform_labels; index++) {
1502                 struct mpls_route *rt = rtnl_dereference(platform_label[index]);
1503 
1504                 if (!rt)
1505                         continue;
1506 
1507                 alive = 0;
1508                 change_nexthops(rt) {
1509                         unsigned int nh_flags = nh->nh_flags;
1510                         struct net_device *nh_dev =
1511                                 rtnl_dereference(nh->nh_dev);
1512 
1513                         if (!(nh_flags & flags)) {
1514                                 alive++;
1515                                 continue;
1516                         }
1517                         if (nh_dev != dev)
1518                                 continue;
1519                         alive++;
1520                         nh_flags &= ~flags;
1521                         WRITE_ONCE(nh->nh_flags, nh_flags);
1522                 } endfor_nexthops(rt);
1523 
1524                 WRITE_ONCE(rt->rt_nhn_alive, alive);
1525         }
1526 }
1527 
1528 static int mpls_dev_notify(struct notifier_block *this, unsigned long event,
1529                            void *ptr)
1530 {
1531         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1532         struct mpls_dev *mdev;
1533         unsigned int flags;
1534 
1535         if (event == NETDEV_REGISTER) {
1536                 /* For now just support Ethernet, IPGRE, SIT and IPIP devices */
1537                 if (dev->type == ARPHRD_ETHER ||
1538                     dev->type == ARPHRD_LOOPBACK ||
1539                     dev->type == ARPHRD_IPGRE ||
1540                     dev->type == ARPHRD_SIT ||
1541                     dev->type == ARPHRD_TUNNEL) {
1542                         mdev = mpls_add_dev(dev);
1543                         if (IS_ERR(mdev))
1544                                 return notifier_from_errno(PTR_ERR(mdev));
1545                 }
1546                 return NOTIFY_OK;
1547         }
1548 
1549         mdev = mpls_dev_get(dev);
1550         if (!mdev)
1551                 return NOTIFY_OK;
1552 
1553         switch (event) {
1554         case NETDEV_DOWN:
1555                 mpls_ifdown(dev, event);
1556                 break;
1557         case NETDEV_UP:
1558                 flags = dev_get_flags(dev);
1559                 if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1560                         mpls_ifup(dev, RTNH_F_DEAD | RTNH_F_LINKDOWN);
1561                 else
1562                         mpls_ifup(dev, RTNH_F_DEAD);
1563                 break;
1564         case NETDEV_CHANGE:
1565                 flags = dev_get_flags(dev);
1566                 if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1567                         mpls_ifup(dev, RTNH_F_DEAD | RTNH_F_LINKDOWN);
1568                 else
1569                         mpls_ifdown(dev, event);
1570                 break;
1571         case NETDEV_UNREGISTER:
1572                 mpls_ifdown(dev, event);
1573                 mdev = mpls_dev_get(dev);
1574                 if (mdev) {
1575                         mpls_dev_sysctl_unregister(dev, mdev);
1576                         RCU_INIT_POINTER(dev->mpls_ptr, NULL);
1577                         call_rcu(&mdev->rcu, mpls_dev_destroy_rcu);
1578                 }
1579                 break;
1580         case NETDEV_CHANGENAME:
1581                 mdev = mpls_dev_get(dev);
1582                 if (mdev) {
1583                         int err;
1584 
1585                         mpls_dev_sysctl_unregister(dev, mdev);
1586                         err = mpls_dev_sysctl_register(dev, mdev);
1587                         if (err)
1588                                 return notifier_from_errno(err);
1589                 }
1590                 break;
1591         }
1592         return NOTIFY_OK;
1593 }
1594 
1595 static struct notifier_block mpls_dev_notifier = {
1596         .notifier_call = mpls_dev_notify,
1597 };
1598 
1599 static int nla_put_via(struct sk_buff *skb,
1600                        u8 table, const void *addr, int alen)
1601 {
1602         static const int table_to_family[NEIGH_NR_TABLES + 1] = {
1603                 AF_INET, AF_INET6, AF_DECnet, AF_PACKET,
1604         };
1605         struct nlattr *nla;
1606         struct rtvia *via;
1607         int family = AF_UNSPEC;
1608 
1609         nla = nla_reserve(skb, RTA_VIA, alen + 2);
1610         if (!nla)
1611                 return -EMSGSIZE;
1612 
1613         if (table <= NEIGH_NR_TABLES)
1614                 family = table_to_family[table];
1615 
1616         via = nla_data(nla);
1617         via->rtvia_family = family;
1618         memcpy(via->rtvia_addr, addr, alen);
1619         return 0;
1620 }
1621 
1622 int nla_put_labels(struct sk_buff *skb, int attrtype,
1623                    u8 labels, const u32 label[])
1624 {
1625         struct nlattr *nla;
1626         struct mpls_shim_hdr *nla_label;
1627         bool bos;
1628         int i;
1629         nla = nla_reserve(skb, attrtype, labels*4);
1630         if (!nla)
1631                 return -EMSGSIZE;
1632 
1633         nla_label = nla_data(nla);
1634         bos = true;
1635         for (i = labels - 1; i >= 0; i--) {
1636                 nla_label[i] = mpls_entry_encode(label[i], 0, 0, bos);
1637                 bos = false;
1638         }
1639 
1640         return 0;
1641 }
1642 EXPORT_SYMBOL_GPL(nla_put_labels);
1643 
1644 int nla_get_labels(const struct nlattr *nla, u8 max_labels, u8 *labels,
1645                    u32 label[], struct netlink_ext_ack *extack)
1646 {
1647         unsigned len = nla_len(nla);
1648         struct mpls_shim_hdr *nla_label;
1649         u8 nla_labels;
1650         bool bos;
1651         int i;
1652 
1653         /* len needs to be an even multiple of 4 (the label size). Number
1654          * of labels is a u8 so check for overflow.
1655          */
1656         if (len & 3 || len / 4 > 255) {
1657                 NL_SET_ERR_MSG_ATTR(extack, nla,
1658                                     "Invalid length for labels attribute");
1659                 return -EINVAL;
1660         }
1661 
1662         /* Limit the number of new labels allowed */
1663         nla_labels = len/4;
1664         if (nla_labels > max_labels) {
1665                 NL_SET_ERR_MSG(extack, "Too many labels");
1666                 return -EINVAL;
1667         }
1668 
1669         /* when label == NULL, caller wants number of labels */
1670         if (!label)
1671                 goto out;
1672 
1673         nla_label = nla_data(nla);
1674         bos = true;
1675         for (i = nla_labels - 1; i >= 0; i--, bos = false) {
1676                 struct mpls_entry_decoded dec;
1677                 dec = mpls_entry_decode(nla_label + i);
1678 
1679                 /* Ensure the bottom of stack flag is properly set
1680                  * and ttl and tc are both clear.
1681                  */
1682                 if (dec.ttl) {
1683                         NL_SET_ERR_MSG_ATTR(extack, nla,
1684                                             "TTL in label must be 0");
1685                         return -EINVAL;
1686                 }
1687 
1688                 if (dec.tc) {
1689                         NL_SET_ERR_MSG_ATTR(extack, nla,
1690                                             "Traffic class in label must be 0");
1691                         return -EINVAL;
1692                 }
1693 
1694                 if (dec.bos != bos) {
1695                         NL_SET_BAD_ATTR(extack, nla);
1696                         if (bos) {
1697                                 NL_SET_ERR_MSG(extack,
1698                                                "BOS bit must be set in first label");
1699                         } else {
1700                                 NL_SET_ERR_MSG(extack,
1701                                                "BOS bit can only be set in first label");
1702                         }
1703                         return -EINVAL;
1704                 }
1705 
1706                 switch (dec.label) {
1707                 case MPLS_LABEL_IMPLNULL:
1708                         /* RFC3032: This is a label that an LSR may
1709                          * assign and distribute, but which never
1710                          * actually appears in the encapsulation.
1711                          */
1712                         NL_SET_ERR_MSG_ATTR(extack, nla,
1713                                             "Implicit NULL Label (3) can not be used in encapsulation");
1714                         return -EINVAL;
1715                 }
1716 
1717                 label[i] = dec.label;
1718         }
1719 out:
1720         *labels = nla_labels;
1721         return 0;
1722 }
1723 EXPORT_SYMBOL_GPL(nla_get_labels);
1724 
1725 static int rtm_to_route_config(struct sk_buff *skb,
1726                                struct nlmsghdr *nlh,
1727                                struct mpls_route_config *cfg,
1728                                struct netlink_ext_ack *extack)
1729 {
1730         struct rtmsg *rtm;
1731         struct nlattr *tb[RTA_MAX+1];
1732         int index;
1733         int err;
1734 
1735         err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_mpls_policy,
1736                           extack);
1737         if (err < 0)
1738                 goto errout;
1739 
1740         err = -EINVAL;
1741         rtm = nlmsg_data(nlh);
1742 
1743         if (rtm->rtm_family != AF_MPLS) {
1744                 NL_SET_ERR_MSG(extack, "Invalid address family in rtmsg");
1745                 goto errout;
1746         }
1747         if (rtm->rtm_dst_len != 20) {
1748                 NL_SET_ERR_MSG(extack, "rtm_dst_len must be 20 for MPLS");
1749                 goto errout;
1750         }
1751         if (rtm->rtm_src_len != 0) {
1752                 NL_SET_ERR_MSG(extack, "rtm_src_len must be 0 for MPLS");
1753                 goto errout;
1754         }
1755         if (rtm->rtm_tos != 0) {
1756                 NL_SET_ERR_MSG(extack, "rtm_tos must be 0 for MPLS");
1757                 goto errout;
1758         }
1759         if (rtm->rtm_table != RT_TABLE_MAIN) {
1760                 NL_SET_ERR_MSG(extack,
1761                                "MPLS only supports the main route table");
1762                 goto errout;
1763         }
1764         /* Any value is acceptable for rtm_protocol */
1765 
1766         /* As mpls uses destination specific addresses
1767          * (or source specific address in the case of multicast)
1768          * all addresses have universal scope.
1769          */
1770         if (rtm->rtm_scope != RT_SCOPE_UNIVERSE) {
1771                 NL_SET_ERR_MSG(extack,
1772                                "Invalid route scope  - MPLS only supports UNIVERSE");
1773                 goto errout;
1774         }
1775         if (rtm->rtm_type != RTN_UNICAST) {
1776                 NL_SET_ERR_MSG(extack,
1777                                "Invalid route type - MPLS only supports UNICAST");
1778                 goto errout;
1779         }
1780         if (rtm->rtm_flags != 0) {
1781                 NL_SET_ERR_MSG(extack, "rtm_flags must be 0 for MPLS");
1782                 goto errout;
1783         }
1784 
1785         cfg->rc_label           = LABEL_NOT_SPECIFIED;
1786         cfg->rc_protocol        = rtm->rtm_protocol;
1787         cfg->rc_via_table       = MPLS_NEIGH_TABLE_UNSPEC;
1788         cfg->rc_ttl_propagate   = MPLS_TTL_PROP_DEFAULT;
1789         cfg->rc_nlflags         = nlh->nlmsg_flags;
1790         cfg->rc_nlinfo.portid   = NETLINK_CB(skb).portid;
1791         cfg->rc_nlinfo.nlh      = nlh;
1792         cfg->rc_nlinfo.nl_net   = sock_net(skb->sk);
1793 
1794         for (index = 0; index <= RTA_MAX; index++) {
1795                 struct nlattr *nla = tb[index];
1796                 if (!nla)
1797                         continue;
1798 
1799                 switch (index) {
1800                 case RTA_OIF:
1801                         cfg->rc_ifindex = nla_get_u32(nla);
1802                         break;
1803                 case RTA_NEWDST:
1804                         if (nla_get_labels(nla, MAX_NEW_LABELS,
1805                                            &cfg->rc_output_labels,
1806                                            cfg->rc_output_label, extack))
1807                                 goto errout;
1808                         break;
1809                 case RTA_DST:
1810                 {
1811                         u8 label_count;
1812                         if (nla_get_labels(nla, 1, &label_count,
1813                                            &cfg->rc_label, extack))
1814                                 goto errout;
1815 
1816                         if (!mpls_label_ok(cfg->rc_nlinfo.nl_net,
1817                                            &cfg->rc_label, extack))
1818                                 goto errout;
1819                         break;
1820                 }
1821                 case RTA_VIA:
1822                 {
1823                         if (nla_get_via(nla, &cfg->rc_via_alen,
1824                                         &cfg->rc_via_table, cfg->rc_via,
1825                                         extack))
1826                                 goto errout;
1827                         break;
1828                 }
1829                 case RTA_MULTIPATH:
1830                 {
1831                         cfg->rc_mp = nla_data(nla);
1832                         cfg->rc_mp_len = nla_len(nla);
1833                         break;
1834                 }
1835                 case RTA_TTL_PROPAGATE:
1836                 {
1837                         u8 ttl_propagate = nla_get_u8(nla);
1838 
1839                         if (ttl_propagate > 1) {
1840                                 NL_SET_ERR_MSG_ATTR(extack, nla,
1841                                                     "RTA_TTL_PROPAGATE can only be 0 or 1");
1842                                 goto errout;
1843                         }
1844                         cfg->rc_ttl_propagate = ttl_propagate ?
1845                                 MPLS_TTL_PROP_ENABLED :
1846                                 MPLS_TTL_PROP_DISABLED;
1847                         break;
1848                 }
1849                 default:
1850                         NL_SET_ERR_MSG_ATTR(extack, nla, "Unknown attribute");
1851                         /* Unsupported attribute */
1852                         goto errout;
1853                 }
1854         }
1855 
1856         err = 0;
1857 errout:
1858         return err;
1859 }
1860 
1861 static int mpls_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
1862                              struct netlink_ext_ack *extack)
1863 {
1864         struct mpls_route_config *cfg;
1865         int err;
1866 
1867         cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
1868         if (!cfg)
1869                 return -ENOMEM;
1870 
1871         err = rtm_to_route_config(skb, nlh, cfg, extack);
1872         if (err < 0)
1873                 goto out;
1874 
1875         err = mpls_route_del(cfg, extack);
1876 out:
1877         kfree(cfg);
1878 
1879         return err;
1880 }
1881 
1882 
1883 static int mpls_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
1884                              struct netlink_ext_ack *extack)
1885 {
1886         struct mpls_route_config *cfg;
1887         int err;
1888 
1889         cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
1890         if (!cfg)
1891                 return -ENOMEM;
1892 
1893         err = rtm_to_route_config(skb, nlh, cfg, extack);
1894         if (err < 0)
1895                 goto out;
1896 
1897         err = mpls_route_add(cfg, extack);
1898 out:
1899         kfree(cfg);
1900 
1901         return err;
1902 }
1903 
1904 static int mpls_dump_route(struct sk_buff *skb, u32 portid, u32 seq, int event,
1905                            u32 label, struct mpls_route *rt, int flags)
1906 {
1907         struct net_device *dev;
1908         struct nlmsghdr *nlh;
1909         struct rtmsg *rtm;
1910 
1911         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), flags);
1912         if (nlh == NULL)
1913                 return -EMSGSIZE;
1914 
1915         rtm = nlmsg_data(nlh);
1916         rtm->rtm_family = AF_MPLS;
1917         rtm->rtm_dst_len = 20;
1918         rtm->rtm_src_len = 0;
1919         rtm->rtm_tos = 0;
1920         rtm->rtm_table = RT_TABLE_MAIN;
1921         rtm->rtm_protocol = rt->rt_protocol;
1922         rtm->rtm_scope = RT_SCOPE_UNIVERSE;
1923         rtm->rtm_type = RTN_UNICAST;
1924         rtm->rtm_flags = 0;
1925 
1926         if (nla_put_labels(skb, RTA_DST, 1, &label))
1927                 goto nla_put_failure;
1928 
1929         if (rt->rt_ttl_propagate != MPLS_TTL_PROP_DEFAULT) {
1930                 bool ttl_propagate =
1931                         rt->rt_ttl_propagate == MPLS_TTL_PROP_ENABLED;
1932 
1933                 if (nla_put_u8(skb, RTA_TTL_PROPAGATE,
1934                                ttl_propagate))
1935                         goto nla_put_failure;
1936         }
1937         if (rt->rt_nhn == 1) {
1938                 const struct mpls_nh *nh = rt->rt_nh;
1939 
1940                 if (nh->nh_labels &&
1941                     nla_put_labels(skb, RTA_NEWDST, nh->nh_labels,
1942                                    nh->nh_label))
1943                         goto nla_put_failure;
1944                 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC &&
1945                     nla_put_via(skb, nh->nh_via_table, mpls_nh_via(rt, nh),
1946                                 nh->nh_via_alen))
1947                         goto nla_put_failure;
1948                 dev = rtnl_dereference(nh->nh_dev);
1949                 if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex))
1950                         goto nla_put_failure;
1951                 if (nh->nh_flags & RTNH_F_LINKDOWN)
1952                         rtm->rtm_flags |= RTNH_F_LINKDOWN;
1953                 if (nh->nh_flags & RTNH_F_DEAD)
1954                         rtm->rtm_flags |= RTNH_F_DEAD;
1955         } else {
1956                 struct rtnexthop *rtnh;
1957                 struct nlattr *mp;
1958                 u8 linkdown = 0;
1959                 u8 dead = 0;
1960 
1961                 mp = nla_nest_start(skb, RTA_MULTIPATH);
1962                 if (!mp)
1963                         goto nla_put_failure;
1964 
1965                 for_nexthops(rt) {
1966                         dev = rtnl_dereference(nh->nh_dev);
1967                         if (!dev)
1968                                 continue;
1969 
1970                         rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh));
1971                         if (!rtnh)
1972                                 goto nla_put_failure;
1973 
1974                         rtnh->rtnh_ifindex = dev->ifindex;
1975                         if (nh->nh_flags & RTNH_F_LINKDOWN) {
1976                                 rtnh->rtnh_flags |= RTNH_F_LINKDOWN;
1977                                 linkdown++;
1978                         }
1979                         if (nh->nh_flags & RTNH_F_DEAD) {
1980                                 rtnh->rtnh_flags |= RTNH_F_DEAD;
1981                                 dead++;
1982                         }
1983 
1984                         if (nh->nh_labels && nla_put_labels(skb, RTA_NEWDST,
1985                                                             nh->nh_labels,
1986                                                             nh->nh_label))
1987                                 goto nla_put_failure;
1988                         if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC &&
1989                             nla_put_via(skb, nh->nh_via_table,
1990                                         mpls_nh_via(rt, nh),
1991                                         nh->nh_via_alen))
1992                                 goto nla_put_failure;
1993 
1994                         /* length of rtnetlink header + attributes */
1995                         rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *)rtnh;
1996                 } endfor_nexthops(rt);
1997 
1998                 if (linkdown == rt->rt_nhn)
1999                         rtm->rtm_flags |= RTNH_F_LINKDOWN;
2000                 if (dead == rt->rt_nhn)
2001                         rtm->rtm_flags |= RTNH_F_DEAD;
2002 
2003                 nla_nest_end(skb, mp);
2004         }
2005 
2006         nlmsg_end(skb, nlh);
2007         return 0;
2008 
2009 nla_put_failure:
2010         nlmsg_cancel(skb, nlh);
2011         return -EMSGSIZE;
2012 }
2013 
2014 static int mpls_dump_routes(struct sk_buff *skb, struct netlink_callback *cb)
2015 {
2016         struct net *net = sock_net(skb->sk);
2017         struct mpls_route __rcu **platform_label;
2018         size_t platform_labels;
2019         unsigned int index;
2020 
2021         ASSERT_RTNL();
2022 
2023         index = cb->args[0];
2024         if (index < MPLS_LABEL_FIRST_UNRESERVED)
2025                 index = MPLS_LABEL_FIRST_UNRESERVED;
2026 
2027         platform_label = rtnl_dereference(net->mpls.platform_label);
2028         platform_labels = net->mpls.platform_labels;
2029         for (; index < platform_labels; index++) {
2030                 struct mpls_route *rt;
2031                 rt = rtnl_dereference(platform_label[index]);
2032                 if (!rt)
2033                         continue;
2034 
2035                 if (mpls_dump_route(skb, NETLINK_CB(cb->skb).portid,
2036                                     cb->nlh->nlmsg_seq, RTM_NEWROUTE,
2037                                     index, rt, NLM_F_MULTI) < 0)
2038                         break;
2039         }
2040         cb->args[0] = index;
2041 
2042         return skb->len;
2043 }
2044 
2045 static inline size_t lfib_nlmsg_size(struct mpls_route *rt)
2046 {
2047         size_t payload =
2048                 NLMSG_ALIGN(sizeof(struct rtmsg))
2049                 + nla_total_size(4)                     /* RTA_DST */
2050                 + nla_total_size(1);                    /* RTA_TTL_PROPAGATE */
2051 
2052         if (rt->rt_nhn == 1) {
2053                 struct mpls_nh *nh = rt->rt_nh;
2054 
2055                 if (nh->nh_dev)
2056                         payload += nla_total_size(4); /* RTA_OIF */
2057                 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC) /* RTA_VIA */
2058                         payload += nla_total_size(2 + nh->nh_via_alen);
2059                 if (nh->nh_labels) /* RTA_NEWDST */
2060                         payload += nla_total_size(nh->nh_labels * 4);
2061         } else {
2062                 /* each nexthop is packed in an attribute */
2063                 size_t nhsize = 0;
2064 
2065                 for_nexthops(rt) {
2066                         if (!rtnl_dereference(nh->nh_dev))
2067                                 continue;
2068                         nhsize += nla_total_size(sizeof(struct rtnexthop));
2069                         /* RTA_VIA */
2070                         if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC)
2071                                 nhsize += nla_total_size(2 + nh->nh_via_alen);
2072                         if (nh->nh_labels)
2073                                 nhsize += nla_total_size(nh->nh_labels * 4);
2074                 } endfor_nexthops(rt);
2075                 /* nested attribute */
2076                 payload += nla_total_size(nhsize);
2077         }
2078 
2079         return payload;
2080 }
2081 
2082 static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt,
2083                        struct nlmsghdr *nlh, struct net *net, u32 portid,
2084                        unsigned int nlm_flags)
2085 {
2086         struct sk_buff *skb;
2087         u32 seq = nlh ? nlh->nlmsg_seq : 0;
2088         int err = -ENOBUFS;
2089 
2090         skb = nlmsg_new(lfib_nlmsg_size(rt), GFP_KERNEL);
2091         if (skb == NULL)
2092                 goto errout;
2093 
2094         err = mpls_dump_route(skb, portid, seq, event, label, rt, nlm_flags);
2095         if (err < 0) {
2096                 /* -EMSGSIZE implies BUG in lfib_nlmsg_size */
2097                 WARN_ON(err == -EMSGSIZE);
2098                 kfree_skb(skb);
2099                 goto errout;
2100         }
2101         rtnl_notify(skb, net, portid, RTNLGRP_MPLS_ROUTE, nlh, GFP_KERNEL);
2102 
2103         return;
2104 errout:
2105         if (err < 0)
2106                 rtnl_set_sk_err(net, RTNLGRP_MPLS_ROUTE, err);
2107 }
2108 
2109 static int mpls_getroute(struct sk_buff *in_skb, struct nlmsghdr *in_nlh,
2110                          struct netlink_ext_ack *extack)
2111 {
2112         struct net *net = sock_net(in_skb->sk);
2113         u32 portid = NETLINK_CB(in_skb).portid;
2114         u32 in_label = LABEL_NOT_SPECIFIED;
2115         struct nlattr *tb[RTA_MAX + 1];
2116         u32 labels[MAX_NEW_LABELS];
2117         struct mpls_shim_hdr *hdr;
2118         unsigned int hdr_size = 0;
2119         struct net_device *dev;
2120         struct mpls_route *rt;
2121         struct rtmsg *rtm, *r;
2122         struct nlmsghdr *nlh;
2123         struct sk_buff *skb;
2124         struct mpls_nh *nh;
2125         u8 n_labels;
2126         int err;
2127 
2128         err = nlmsg_parse(in_nlh, sizeof(*rtm), tb, RTA_MAX,
2129                           rtm_mpls_policy, extack);
2130         if (err < 0)
2131                 goto errout;
2132 
2133         rtm = nlmsg_data(in_nlh);
2134 
2135         if (tb[RTA_DST]) {
2136                 u8 label_count;
2137 
2138                 if (nla_get_labels(tb[RTA_DST], 1, &label_count,
2139                                    &in_label, extack)) {
2140                         err = -EINVAL;
2141                         goto errout;
2142                 }
2143 
2144                 if (!mpls_label_ok(net, &in_label, extack)) {
2145                         err = -EINVAL;
2146                         goto errout;
2147                 }
2148         }
2149 
2150         rt = mpls_route_input_rcu(net, in_label);
2151         if (!rt) {
2152                 err = -ENETUNREACH;
2153                 goto errout;
2154         }
2155 
2156         if (rtm->rtm_flags & RTM_F_FIB_MATCH) {
2157                 skb = nlmsg_new(lfib_nlmsg_size(rt), GFP_KERNEL);
2158                 if (!skb) {
2159                         err = -ENOBUFS;
2160                         goto errout;
2161                 }
2162 
2163                 err = mpls_dump_route(skb, portid, in_nlh->nlmsg_seq,
2164                                       RTM_NEWROUTE, in_label, rt, 0);
2165                 if (err < 0) {
2166                         /* -EMSGSIZE implies BUG in lfib_nlmsg_size */
2167                         WARN_ON(err == -EMSGSIZE);
2168                         goto errout_free;
2169                 }
2170 
2171                 return rtnl_unicast(skb, net, portid);
2172         }
2173 
2174         if (tb[RTA_NEWDST]) {
2175                 if (nla_get_labels(tb[RTA_NEWDST], MAX_NEW_LABELS, &n_labels,
2176                                    labels, extack) != 0) {
2177                         err = -EINVAL;
2178                         goto errout;
2179                 }
2180 
2181                 hdr_size = n_labels * sizeof(struct mpls_shim_hdr);
2182         }
2183 
2184         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2185         if (!skb) {
2186                 err = -ENOBUFS;
2187                 goto errout;
2188         }
2189 
2190         skb->protocol = htons(ETH_P_MPLS_UC);
2191 
2192         if (hdr_size) {
2193                 bool bos;
2194                 int i;
2195 
2196                 if (skb_cow(skb, hdr_size)) {
2197                         err = -ENOBUFS;
2198                         goto errout_free;
2199                 }
2200 
2201                 skb_reserve(skb, hdr_size);
2202                 skb_push(skb, hdr_size);
2203                 skb_reset_network_header(skb);
2204 
2205                 /* Push new labels */
2206                 hdr = mpls_hdr(skb);
2207                 bos = true;
2208                 for (i = n_labels - 1; i >= 0; i--) {
2209                         hdr[i] = mpls_entry_encode(labels[i],
2210                                                    1, 0, bos);
2211                         bos = false;
2212                 }
2213         }
2214 
2215         nh = mpls_select_multipath(rt, skb);
2216         if (!nh) {
2217                 err = -ENETUNREACH;
2218                 goto errout_free;
2219         }
2220 
2221         if (hdr_size) {
2222                 skb_pull(skb, hdr_size);
2223                 skb_reset_network_header(skb);
2224         }
2225 
2226         nlh = nlmsg_put(skb, portid, in_nlh->nlmsg_seq,
2227                         RTM_NEWROUTE, sizeof(*r), 0);
2228         if (!nlh) {
2229                 err = -EMSGSIZE;
2230                 goto errout_free;
2231         }
2232 
2233         r = nlmsg_data(nlh);
2234         r->rtm_family    = AF_MPLS;
2235         r->rtm_dst_len  = 20;
2236         r->rtm_src_len  = 0;
2237         r->rtm_table    = RT_TABLE_MAIN;
2238         r->rtm_type     = RTN_UNICAST;
2239         r->rtm_scope    = RT_SCOPE_UNIVERSE;
2240         r->rtm_protocol = rt->rt_protocol;
2241         r->rtm_flags    = 0;
2242 
2243         if (nla_put_labels(skb, RTA_DST, 1, &in_label))
2244                 goto nla_put_failure;
2245 
2246         if (nh->nh_labels &&
2247             nla_put_labels(skb, RTA_NEWDST, nh->nh_labels,
2248                            nh->nh_label))
2249                 goto nla_put_failure;
2250 
2251         if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC &&
2252             nla_put_via(skb, nh->nh_via_table, mpls_nh_via(rt, nh),
2253                         nh->nh_via_alen))
2254                 goto nla_put_failure;
2255         dev = rtnl_dereference(nh->nh_dev);
2256         if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex))
2257                 goto nla_put_failure;
2258 
2259         nlmsg_end(skb, nlh);
2260 
2261         err = rtnl_unicast(skb, net, portid);
2262 errout:
2263         return err;
2264 
2265 nla_put_failure:
2266         nlmsg_cancel(skb, nlh);
2267         err = -EMSGSIZE;
2268 errout_free:
2269         kfree_skb(skb);
2270         return err;
2271 }
2272 
2273 static int resize_platform_label_table(struct net *net, size_t limit)
2274 {
2275         size_t size = sizeof(struct mpls_route *) * limit;
2276         size_t old_limit;
2277         size_t cp_size;
2278         struct mpls_route __rcu **labels = NULL, **old;
2279         struct mpls_route *rt0 = NULL, *rt2 = NULL;
2280         unsigned index;
2281 
2282         if (size) {
2283                 labels = kvzalloc(size, GFP_KERNEL);
2284                 if (!labels)
2285                         goto nolabels;
2286         }
2287 
2288         /* In case the predefined labels need to be populated */
2289         if (limit > MPLS_LABEL_IPV4NULL) {
2290                 struct net_device *lo = net->loopback_dev;
2291                 rt0 = mpls_rt_alloc(1, lo->addr_len, 0);
2292                 if (IS_ERR(rt0))
2293                         goto nort0;
2294                 RCU_INIT_POINTER(rt0->rt_nh->nh_dev, lo);
2295                 rt0->rt_protocol = RTPROT_KERNEL;
2296                 rt0->rt_payload_type = MPT_IPV4;
2297                 rt0->rt_ttl_propagate = MPLS_TTL_PROP_DEFAULT;
2298                 rt0->rt_nh->nh_via_table = NEIGH_LINK_TABLE;
2299                 rt0->rt_nh->nh_via_alen = lo->addr_len;
2300                 memcpy(__mpls_nh_via(rt0, rt0->rt_nh), lo->dev_addr,
2301                        lo->addr_len);
2302         }
2303         if (limit > MPLS_LABEL_IPV6NULL) {
2304                 struct net_device *lo = net->loopback_dev;
2305                 rt2 = mpls_rt_alloc(1, lo->addr_len, 0);
2306                 if (IS_ERR(rt2))
2307                         goto nort2;
2308                 RCU_INIT_POINTER(rt2->rt_nh->nh_dev, lo);
2309                 rt2->rt_protocol = RTPROT_KERNEL;
2310                 rt2->rt_payload_type = MPT_IPV6;
2311                 rt2->rt_ttl_propagate = MPLS_TTL_PROP_DEFAULT;
2312                 rt2->rt_nh->nh_via_table = NEIGH_LINK_TABLE;
2313                 rt2->rt_nh->nh_via_alen = lo->addr_len;
2314                 memcpy(__mpls_nh_via(rt2, rt2->rt_nh), lo->dev_addr,
2315                        lo->addr_len);
2316         }
2317 
2318         rtnl_lock();
2319         /* Remember the original table */
2320         old = rtnl_dereference(net->mpls.platform_label);
2321         old_limit = net->mpls.platform_labels;
2322 
2323         /* Free any labels beyond the new table */
2324         for (index = limit; index < old_limit; index++)
2325                 mpls_route_update(net, index, NULL, NULL);
2326 
2327         /* Copy over the old labels */
2328         cp_size = size;
2329         if (old_limit < limit)
2330                 cp_size = old_limit * sizeof(struct mpls_route *);
2331 
2332         memcpy(labels, old, cp_size);
2333 
2334         /* If needed set the predefined labels */
2335         if ((old_limit <= MPLS_LABEL_IPV6NULL) &&
2336             (limit > MPLS_LABEL_IPV6NULL)) {
2337                 RCU_INIT_POINTER(labels[MPLS_LABEL_IPV6NULL], rt2);
2338                 rt2 = NULL;
2339         }
2340 
2341         if ((old_limit <= MPLS_LABEL_IPV4NULL) &&
2342             (limit > MPLS_LABEL_IPV4NULL)) {
2343                 RCU_INIT_POINTER(labels[MPLS_LABEL_IPV4NULL], rt0);
2344                 rt0 = NULL;
2345         }
2346 
2347         /* Update the global pointers */
2348         net->mpls.platform_labels = limit;
2349         rcu_assign_pointer(net->mpls.platform_label, labels);
2350 
2351         rtnl_unlock();
2352 
2353         mpls_rt_free(rt2);
2354         mpls_rt_free(rt0);
2355 
2356         if (old) {
2357                 synchronize_rcu();
2358                 kvfree(old);
2359         }
2360         return 0;
2361 
2362 nort2:
2363         mpls_rt_free(rt0);
2364 nort0:
2365         kvfree(labels);
2366 nolabels:
2367         return -ENOMEM;
2368 }
2369 
2370 static int mpls_platform_labels(struct ctl_table *table, int write,
2371                                 void __user *buffer, size_t *lenp, loff_t *ppos)
2372 {
2373         struct net *net = table->data;
2374         int platform_labels = net->mpls.platform_labels;
2375         int ret;
2376         struct ctl_table tmp = {
2377                 .procname       = table->procname,
2378                 .data           = &platform_labels,
2379                 .maxlen         = sizeof(int),
2380                 .mode           = table->mode,
2381                 .extra1         = &zero,
2382                 .extra2         = &label_limit,
2383         };
2384 
2385         ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
2386 
2387         if (write && ret == 0)
2388                 ret = resize_platform_label_table(net, platform_labels);
2389 
2390         return ret;
2391 }
2392 
2393 #define MPLS_NS_SYSCTL_OFFSET(field)            \
2394         (&((struct net *)0)->field)
2395 
2396 static const struct ctl_table mpls_table[] = {
2397         {
2398                 .procname       = "platform_labels",
2399                 .data           = NULL,
2400                 .maxlen         = sizeof(int),
2401                 .mode           = 0644,
2402                 .proc_handler   = mpls_platform_labels,
2403         },
2404         {
2405                 .procname       = "ip_ttl_propagate",
2406                 .data           = MPLS_NS_SYSCTL_OFFSET(mpls.ip_ttl_propagate),
2407                 .maxlen         = sizeof(int),
2408                 .mode           = 0644,
2409                 .proc_handler   = proc_dointvec_minmax,
2410                 .extra1         = &zero,
2411                 .extra2         = &one,
2412         },
2413         {
2414                 .procname       = "default_ttl",
2415                 .data           = MPLS_NS_SYSCTL_OFFSET(mpls.default_ttl),
2416                 .maxlen         = sizeof(int),
2417                 .mode           = 0644,
2418                 .proc_handler   = proc_dointvec_minmax,
2419                 .extra1         = &one,
2420                 .extra2         = &ttl_max,
2421         },
2422         { }
2423 };
2424 
2425 static int mpls_net_init(struct net *net)
2426 {
2427         struct ctl_table *table;
2428         int i;
2429 
2430         net->mpls.platform_labels = 0;
2431         net->mpls.platform_label = NULL;
2432         net->mpls.ip_ttl_propagate = 1;
2433         net->mpls.default_ttl = 255;
2434 
2435         table = kmemdup(mpls_table, sizeof(mpls_table), GFP_KERNEL);
2436         if (table == NULL)
2437                 return -ENOMEM;
2438 
2439         /* Table data contains only offsets relative to the base of
2440          * the mdev at this point, so make them absolute.
2441          */
2442         for (i = 0; i < ARRAY_SIZE(mpls_table) - 1; i++)
2443                 table[i].data = (char *)net + (uintptr_t)table[i].data;
2444 
2445         net->mpls.ctl = register_net_sysctl(net, "net/mpls", table);
2446         if (net->mpls.ctl == NULL) {
2447                 kfree(table);
2448                 return -ENOMEM;
2449         }
2450 
2451         return 0;
2452 }
2453 
2454 static void mpls_net_exit(struct net *net)
2455 {
2456         struct mpls_route __rcu **platform_label;
2457         size_t platform_labels;
2458         struct ctl_table *table;
2459         unsigned int index;
2460 
2461         table = net->mpls.ctl->ctl_table_arg;
2462         unregister_net_sysctl_table(net->mpls.ctl);
2463         kfree(table);
2464 
2465         /* An rcu grace period has passed since there was a device in
2466          * the network namespace (and thus the last in flight packet)
2467          * left this network namespace.  This is because
2468          * unregister_netdevice_many and netdev_run_todo has completed
2469          * for each network device that was in this network namespace.
2470          *
2471          * As such no additional rcu synchronization is necessary when
2472          * freeing the platform_label table.
2473          */
2474         rtnl_lock();
2475         platform_label = rtnl_dereference(net->mpls.platform_label);
2476         platform_labels = net->mpls.platform_labels;
2477         for (index = 0; index < platform_labels; index++) {
2478                 struct mpls_route *rt = rtnl_dereference(platform_label[index]);
2479                 RCU_INIT_POINTER(platform_label[index], NULL);
2480                 mpls_notify_route(net, index, rt, NULL, NULL);
2481                 mpls_rt_free(rt);
2482         }
2483         rtnl_unlock();
2484 
2485         kvfree(platform_label);
2486 }
2487 
2488 static struct pernet_operations mpls_net_ops = {
2489         .init = mpls_net_init,
2490         .exit = mpls_net_exit,
2491 };
2492 
2493 static struct rtnl_af_ops mpls_af_ops __read_mostly = {
2494         .family            = AF_MPLS,
2495         .fill_stats_af     = mpls_fill_stats_af,
2496         .get_stats_af_size = mpls_get_stats_af_size,
2497 };
2498 
2499 static int __init mpls_init(void)
2500 {
2501         int err;
2502 
2503         BUILD_BUG_ON(sizeof(struct mpls_shim_hdr) != 4);
2504 
2505         err = register_pernet_subsys(&mpls_net_ops);
2506         if (err)
2507                 goto out;
2508 
2509         err = register_netdevice_notifier(&mpls_dev_notifier);
2510         if (err)
2511                 goto out_unregister_pernet;
2512 
2513         dev_add_pack(&mpls_packet_type);
2514 
2515         rtnl_af_register(&mpls_af_ops);
2516 
2517         rtnl_register(PF_MPLS, RTM_NEWROUTE, mpls_rtm_newroute, NULL, 0);
2518         rtnl_register(PF_MPLS, RTM_DELROUTE, mpls_rtm_delroute, NULL, 0);
2519         rtnl_register(PF_MPLS, RTM_GETROUTE, mpls_getroute, mpls_dump_routes,
2520                       0);
2521         rtnl_register(PF_MPLS, RTM_GETNETCONF, mpls_netconf_get_devconf,
2522                       mpls_netconf_dump_devconf, 0);
2523         err = ipgre_tunnel_encap_add_mpls_ops();
2524         if (err)
2525                 pr_err("Can't add mpls over gre tunnel ops\n");
2526 
2527         err = 0;
2528 out:
2529         return err;
2530 
2531 out_unregister_pernet:
2532         unregister_pernet_subsys(&mpls_net_ops);
2533         goto out;
2534 }
2535 module_init(mpls_init);
2536 
2537 static void __exit mpls_exit(void)
2538 {
2539         rtnl_unregister_all(PF_MPLS);
2540         rtnl_af_unregister(&mpls_af_ops);
2541         dev_remove_pack(&mpls_packet_type);
2542         unregister_netdevice_notifier(&mpls_dev_notifier);
2543         unregister_pernet_subsys(&mpls_net_ops);
2544         ipgre_tunnel_encap_del_mpls_ops();
2545 }
2546 module_exit(mpls_exit);
2547 
2548 MODULE_DESCRIPTION("MultiProtocol Label Switching");
2549 MODULE_LICENSE("GPL v2");
2550 MODULE_ALIAS_NETPROTO(PF_MPLS);
2551 

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