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Linux/net/mpls/af_mpls.c

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  1 // SPDX-License-Identifier: GPL-2.0-only
  2 #include <linux/types.h>
  3 #include <linux/skbuff.h>
  4 #include <linux/socket.h>
  5 #include <linux/sysctl.h>
  6 #include <linux/net.h>
  7 #include <linux/module.h>
  8 #include <linux/if_arp.h>
  9 #include <linux/ipv6.h>
 10 #include <linux/mpls.h>
 11 #include <linux/netconf.h>
 12 #include <linux/nospec.h>
 13 #include <linux/vmalloc.h>
 14 #include <linux/percpu.h>
 15 #include <net/ip.h>
 16 #include <net/dst.h>
 17 #include <net/sock.h>
 18 #include <net/arp.h>
 19 #include <net/ip_fib.h>
 20 #include <net/netevent.h>
 21 #include <net/ip_tunnels.h>
 22 #include <net/netns/generic.h>
 23 #if IS_ENABLED(CONFIG_IPV6)
 24 #include <net/ipv6.h>
 25 #endif
 26 #include <net/ipv6_stubs.h>
 27 #include <net/rtnh.h>
 28 #include "internal.h"
 29 
 30 /* max memory we will use for mpls_route */
 31 #define MAX_MPLS_ROUTE_MEM      4096
 32 
 33 /* Maximum number of labels to look ahead at when selecting a path of
 34  * a multipath route
 35  */
 36 #define MAX_MP_SELECT_LABELS 4
 37 
 38 #define MPLS_NEIGH_TABLE_UNSPEC (NEIGH_LINK_TABLE + 1)
 39 
 40 static int label_limit = (1 << 20) - 1;
 41 static int ttl_max = 255;
 42 
 43 #if IS_ENABLED(CONFIG_NET_IP_TUNNEL)
 44 static size_t ipgre_mpls_encap_hlen(struct ip_tunnel_encap *e)
 45 {
 46         return sizeof(struct mpls_shim_hdr);
 47 }
 48 
 49 static const struct ip_tunnel_encap_ops mpls_iptun_ops = {
 50         .encap_hlen     = ipgre_mpls_encap_hlen,
 51 };
 52 
 53 static int ipgre_tunnel_encap_add_mpls_ops(void)
 54 {
 55         return ip_tunnel_encap_add_ops(&mpls_iptun_ops, TUNNEL_ENCAP_MPLS);
 56 }
 57 
 58 static void ipgre_tunnel_encap_del_mpls_ops(void)
 59 {
 60         ip_tunnel_encap_del_ops(&mpls_iptun_ops, TUNNEL_ENCAP_MPLS);
 61 }
 62 #else
 63 static int ipgre_tunnel_encap_add_mpls_ops(void)
 64 {
 65         return 0;
 66 }
 67 
 68 static void ipgre_tunnel_encap_del_mpls_ops(void)
 69 {
 70 }
 71 #endif
 72 
 73 static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt,
 74                        struct nlmsghdr *nlh, struct net *net, u32 portid,
 75                        unsigned int nlm_flags);
 76 
 77 static struct mpls_route *mpls_route_input_rcu(struct net *net, unsigned index)
 78 {
 79         struct mpls_route *rt = NULL;
 80 
 81         if (index < net->mpls.platform_labels) {
 82                 struct mpls_route __rcu **platform_label =
 83                         rcu_dereference(net->mpls.platform_label);
 84                 rt = rcu_dereference(platform_label[index]);
 85         }
 86         return rt;
 87 }
 88 
 89 bool mpls_output_possible(const struct net_device *dev)
 90 {
 91         return dev && (dev->flags & IFF_UP) && netif_carrier_ok(dev);
 92 }
 93 EXPORT_SYMBOL_GPL(mpls_output_possible);
 94 
 95 static u8 *__mpls_nh_via(struct mpls_route *rt, struct mpls_nh *nh)
 96 {
 97         return (u8 *)nh + rt->rt_via_offset;
 98 }
 99 
100 static const u8 *mpls_nh_via(const struct mpls_route *rt,
101                              const struct mpls_nh *nh)
102 {
103         return __mpls_nh_via((struct mpls_route *)rt, (struct mpls_nh *)nh);
104 }
105 
106 static unsigned int mpls_nh_header_size(const struct mpls_nh *nh)
107 {
108         /* The size of the layer 2.5 labels to be added for this route */
109         return nh->nh_labels * sizeof(struct mpls_shim_hdr);
110 }
111 
112 unsigned int mpls_dev_mtu(const struct net_device *dev)
113 {
114         /* The amount of data the layer 2 frame can hold */
115         return dev->mtu;
116 }
117 EXPORT_SYMBOL_GPL(mpls_dev_mtu);
118 
119 bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu)
120 {
121         if (skb->len <= mtu)
122                 return false;
123 
124         if (skb_is_gso(skb) && skb_gso_validate_network_len(skb, mtu))
125                 return false;
126 
127         return true;
128 }
129 EXPORT_SYMBOL_GPL(mpls_pkt_too_big);
130 
131 void mpls_stats_inc_outucastpkts(struct net_device *dev,
132                                  const struct sk_buff *skb)
133 {
134         struct mpls_dev *mdev;
135 
136         if (skb->protocol == htons(ETH_P_MPLS_UC)) {
137                 mdev = mpls_dev_get(dev);
138                 if (mdev)
139                         MPLS_INC_STATS_LEN(mdev, skb->len,
140                                            tx_packets,
141                                            tx_bytes);
142         } else if (skb->protocol == htons(ETH_P_IP)) {
143                 IP_UPD_PO_STATS(dev_net(dev), IPSTATS_MIB_OUT, skb->len);
144 #if IS_ENABLED(CONFIG_IPV6)
145         } else if (skb->protocol == htons(ETH_P_IPV6)) {
146                 struct inet6_dev *in6dev = __in6_dev_get(dev);
147 
148                 if (in6dev)
149                         IP6_UPD_PO_STATS(dev_net(dev), in6dev,
150                                          IPSTATS_MIB_OUT, skb->len);
151 #endif
152         }
153 }
154 EXPORT_SYMBOL_GPL(mpls_stats_inc_outucastpkts);
155 
156 static u32 mpls_multipath_hash(struct mpls_route *rt, struct sk_buff *skb)
157 {
158         struct mpls_entry_decoded dec;
159         unsigned int mpls_hdr_len = 0;
160         struct mpls_shim_hdr *hdr;
161         bool eli_seen = false;
162         int label_index;
163         u32 hash = 0;
164 
165         for (label_index = 0; label_index < MAX_MP_SELECT_LABELS;
166              label_index++) {
167                 mpls_hdr_len += sizeof(*hdr);
168                 if (!pskb_may_pull(skb, mpls_hdr_len))
169                         break;
170 
171                 /* Read and decode the current label */
172                 hdr = mpls_hdr(skb) + label_index;
173                 dec = mpls_entry_decode(hdr);
174 
175                 /* RFC6790 - reserved labels MUST NOT be used as keys
176                  * for the load-balancing function
177                  */
178                 if (likely(dec.label >= MPLS_LABEL_FIRST_UNRESERVED)) {
179                         hash = jhash_1word(dec.label, hash);
180 
181                         /* The entropy label follows the entropy label
182                          * indicator, so this means that the entropy
183                          * label was just added to the hash - no need to
184                          * go any deeper either in the label stack or in the
185                          * payload
186                          */
187                         if (eli_seen)
188                                 break;
189                 } else if (dec.label == MPLS_LABEL_ENTROPY) {
190                         eli_seen = true;
191                 }
192 
193                 if (!dec.bos)
194                         continue;
195 
196                 /* found bottom label; does skb have room for a header? */
197                 if (pskb_may_pull(skb, mpls_hdr_len + sizeof(struct iphdr))) {
198                         const struct iphdr *v4hdr;
199 
200                         v4hdr = (const struct iphdr *)(hdr + 1);
201                         if (v4hdr->version == 4) {
202                                 hash = jhash_3words(ntohl(v4hdr->saddr),
203                                                     ntohl(v4hdr->daddr),
204                                                     v4hdr->protocol, hash);
205                         } else if (v4hdr->version == 6 &&
206                                    pskb_may_pull(skb, mpls_hdr_len +
207                                                  sizeof(struct ipv6hdr))) {
208                                 const struct ipv6hdr *v6hdr;
209 
210                                 v6hdr = (const struct ipv6hdr *)(hdr + 1);
211                                 hash = __ipv6_addr_jhash(&v6hdr->saddr, hash);
212                                 hash = __ipv6_addr_jhash(&v6hdr->daddr, hash);
213                                 hash = jhash_1word(v6hdr->nexthdr, hash);
214                         }
215                 }
216 
217                 break;
218         }
219 
220         return hash;
221 }
222 
223 static struct mpls_nh *mpls_get_nexthop(struct mpls_route *rt, u8 index)
224 {
225         return (struct mpls_nh *)((u8 *)rt->rt_nh + index * rt->rt_nh_size);
226 }
227 
228 /* number of alive nexthops (rt->rt_nhn_alive) and the flags for
229  * a next hop (nh->nh_flags) are modified by netdev event handlers.
230  * Since those fields can change at any moment, use READ_ONCE to
231  * access both.
232  */
233 static struct mpls_nh *mpls_select_multipath(struct mpls_route *rt,
234                                              struct sk_buff *skb)
235 {
236         u32 hash = 0;
237         int nh_index = 0;
238         int n = 0;
239         u8 alive;
240 
241         /* No need to look further into packet if there's only
242          * one path
243          */
244         if (rt->rt_nhn == 1)
245                 return rt->rt_nh;
246 
247         alive = READ_ONCE(rt->rt_nhn_alive);
248         if (alive == 0)
249                 return NULL;
250 
251         hash = mpls_multipath_hash(rt, skb);
252         nh_index = hash % alive;
253         if (alive == rt->rt_nhn)
254                 goto out;
255         for_nexthops(rt) {
256                 unsigned int nh_flags = READ_ONCE(nh->nh_flags);
257 
258                 if (nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN))
259                         continue;
260                 if (n == nh_index)
261                         return nh;
262                 n++;
263         } endfor_nexthops(rt);
264 
265 out:
266         return mpls_get_nexthop(rt, nh_index);
267 }
268 
269 static bool mpls_egress(struct net *net, struct mpls_route *rt,
270                         struct sk_buff *skb, struct mpls_entry_decoded dec)
271 {
272         enum mpls_payload_type payload_type;
273         bool success = false;
274 
275         /* The IPv4 code below accesses through the IPv4 header
276          * checksum, which is 12 bytes into the packet.
277          * The IPv6 code below accesses through the IPv6 hop limit
278          * which is 8 bytes into the packet.
279          *
280          * For all supported cases there should always be at least 12
281          * bytes of packet data present.  The IPv4 header is 20 bytes
282          * without options and the IPv6 header is always 40 bytes
283          * long.
284          */
285         if (!pskb_may_pull(skb, 12))
286                 return false;
287 
288         payload_type = rt->rt_payload_type;
289         if (payload_type == MPT_UNSPEC)
290                 payload_type = ip_hdr(skb)->version;
291 
292         switch (payload_type) {
293         case MPT_IPV4: {
294                 struct iphdr *hdr4 = ip_hdr(skb);
295                 u8 new_ttl;
296                 skb->protocol = htons(ETH_P_IP);
297 
298                 /* If propagating TTL, take the decremented TTL from
299                  * the incoming MPLS header, otherwise decrement the
300                  * TTL, but only if not 0 to avoid underflow.
301                  */
302                 if (rt->rt_ttl_propagate == MPLS_TTL_PROP_ENABLED ||
303                     (rt->rt_ttl_propagate == MPLS_TTL_PROP_DEFAULT &&
304                      net->mpls.ip_ttl_propagate))
305                         new_ttl = dec.ttl;
306                 else
307                         new_ttl = hdr4->ttl ? hdr4->ttl - 1 : 0;
308 
309                 csum_replace2(&hdr4->check,
310                               htons(hdr4->ttl << 8),
311                               htons(new_ttl << 8));
312                 hdr4->ttl = new_ttl;
313                 success = true;
314                 break;
315         }
316         case MPT_IPV6: {
317                 struct ipv6hdr *hdr6 = ipv6_hdr(skb);
318                 skb->protocol = htons(ETH_P_IPV6);
319 
320                 /* If propagating TTL, take the decremented TTL from
321                  * the incoming MPLS header, otherwise decrement the
322                  * hop limit, but only if not 0 to avoid underflow.
323                  */
324                 if (rt->rt_ttl_propagate == MPLS_TTL_PROP_ENABLED ||
325                     (rt->rt_ttl_propagate == MPLS_TTL_PROP_DEFAULT &&
326                      net->mpls.ip_ttl_propagate))
327                         hdr6->hop_limit = dec.ttl;
328                 else if (hdr6->hop_limit)
329                         hdr6->hop_limit = hdr6->hop_limit - 1;
330                 success = true;
331                 break;
332         }
333         case MPT_UNSPEC:
334                 /* Should have decided which protocol it is by now */
335                 break;
336         }
337 
338         return success;
339 }
340 
341 static int mpls_forward(struct sk_buff *skb, struct net_device *dev,
342                         struct packet_type *pt, struct net_device *orig_dev)
343 {
344         struct net *net = dev_net(dev);
345         struct mpls_shim_hdr *hdr;
346         struct mpls_route *rt;
347         struct mpls_nh *nh;
348         struct mpls_entry_decoded dec;
349         struct net_device *out_dev;
350         struct mpls_dev *out_mdev;
351         struct mpls_dev *mdev;
352         unsigned int hh_len;
353         unsigned int new_header_size;
354         unsigned int mtu;
355         int err;
356 
357         /* Careful this entire function runs inside of an rcu critical section */
358 
359         mdev = mpls_dev_get(dev);
360         if (!mdev)
361                 goto drop;
362 
363         MPLS_INC_STATS_LEN(mdev, skb->len, rx_packets,
364                            rx_bytes);
365 
366         if (!mdev->input_enabled) {
367                 MPLS_INC_STATS(mdev, rx_dropped);
368                 goto drop;
369         }
370 
371         if (skb->pkt_type != PACKET_HOST)
372                 goto err;
373 
374         if ((skb = skb_share_check(skb, GFP_ATOMIC)) == NULL)
375                 goto err;
376 
377         if (!pskb_may_pull(skb, sizeof(*hdr)))
378                 goto err;
379 
380         /* Read and decode the label */
381         hdr = mpls_hdr(skb);
382         dec = mpls_entry_decode(hdr);
383 
384         rt = mpls_route_input_rcu(net, dec.label);
385         if (!rt) {
386                 MPLS_INC_STATS(mdev, rx_noroute);
387                 goto drop;
388         }
389 
390         nh = mpls_select_multipath(rt, skb);
391         if (!nh)
392                 goto err;
393 
394         /* Pop the label */
395         skb_pull(skb, sizeof(*hdr));
396         skb_reset_network_header(skb);
397 
398         skb_orphan(skb);
399 
400         if (skb_warn_if_lro(skb))
401                 goto err;
402 
403         skb_forward_csum(skb);
404 
405         /* Verify ttl is valid */
406         if (dec.ttl <= 1)
407                 goto err;
408         dec.ttl -= 1;
409 
410         /* Find the output device */
411         out_dev = rcu_dereference(nh->nh_dev);
412         if (!mpls_output_possible(out_dev))
413                 goto tx_err;
414 
415         /* Verify the destination can hold the packet */
416         new_header_size = mpls_nh_header_size(nh);
417         mtu = mpls_dev_mtu(out_dev);
418         if (mpls_pkt_too_big(skb, mtu - new_header_size))
419                 goto tx_err;
420 
421         hh_len = LL_RESERVED_SPACE(out_dev);
422         if (!out_dev->header_ops)
423                 hh_len = 0;
424 
425         /* Ensure there is enough space for the headers in the skb */
426         if (skb_cow(skb, hh_len + new_header_size))
427                 goto tx_err;
428 
429         skb->dev = out_dev;
430         skb->protocol = htons(ETH_P_MPLS_UC);
431 
432         if (unlikely(!new_header_size && dec.bos)) {
433                 /* Penultimate hop popping */
434                 if (!mpls_egress(dev_net(out_dev), rt, skb, dec))
435                         goto err;
436         } else {
437                 bool bos;
438                 int i;
439                 skb_push(skb, new_header_size);
440                 skb_reset_network_header(skb);
441                 /* Push the new labels */
442                 hdr = mpls_hdr(skb);
443                 bos = dec.bos;
444                 for (i = nh->nh_labels - 1; i >= 0; i--) {
445                         hdr[i] = mpls_entry_encode(nh->nh_label[i],
446                                                    dec.ttl, 0, bos);
447                         bos = false;
448                 }
449         }
450 
451         mpls_stats_inc_outucastpkts(out_dev, skb);
452 
453         /* If via wasn't specified then send out using device address */
454         if (nh->nh_via_table == MPLS_NEIGH_TABLE_UNSPEC)
455                 err = neigh_xmit(NEIGH_LINK_TABLE, out_dev,
456                                  out_dev->dev_addr, skb);
457         else
458                 err = neigh_xmit(nh->nh_via_table, out_dev,
459                                  mpls_nh_via(rt, nh), skb);
460         if (err)
461                 net_dbg_ratelimited("%s: packet transmission failed: %d\n",
462                                     __func__, err);
463         return 0;
464 
465 tx_err:
466         out_mdev = out_dev ? mpls_dev_get(out_dev) : NULL;
467         if (out_mdev)
468                 MPLS_INC_STATS(out_mdev, tx_errors);
469         goto drop;
470 err:
471         MPLS_INC_STATS(mdev, rx_errors);
472 drop:
473         kfree_skb(skb);
474         return NET_RX_DROP;
475 }
476 
477 static struct packet_type mpls_packet_type __read_mostly = {
478         .type = cpu_to_be16(ETH_P_MPLS_UC),
479         .func = mpls_forward,
480 };
481 
482 static const struct nla_policy rtm_mpls_policy[RTA_MAX+1] = {
483         [RTA_DST]               = { .type = NLA_U32 },
484         [RTA_OIF]               = { .type = NLA_U32 },
485         [RTA_TTL_PROPAGATE]     = { .type = NLA_U8 },
486 };
487 
488 struct mpls_route_config {
489         u32                     rc_protocol;
490         u32                     rc_ifindex;
491         u8                      rc_via_table;
492         u8                      rc_via_alen;
493         u8                      rc_via[MAX_VIA_ALEN];
494         u32                     rc_label;
495         u8                      rc_ttl_propagate;
496         u8                      rc_output_labels;
497         u32                     rc_output_label[MAX_NEW_LABELS];
498         u32                     rc_nlflags;
499         enum mpls_payload_type  rc_payload_type;
500         struct nl_info          rc_nlinfo;
501         struct rtnexthop        *rc_mp;
502         int                     rc_mp_len;
503 };
504 
505 /* all nexthops within a route have the same size based on max
506  * number of labels and max via length for a hop
507  */
508 static struct mpls_route *mpls_rt_alloc(u8 num_nh, u8 max_alen, u8 max_labels)
509 {
510         u8 nh_size = MPLS_NH_SIZE(max_labels, max_alen);
511         struct mpls_route *rt;
512         size_t size;
513 
514         size = sizeof(*rt) + num_nh * nh_size;
515         if (size > MAX_MPLS_ROUTE_MEM)
516                 return ERR_PTR(-EINVAL);
517 
518         rt = kzalloc(size, GFP_KERNEL);
519         if (!rt)
520                 return ERR_PTR(-ENOMEM);
521 
522         rt->rt_nhn = num_nh;
523         rt->rt_nhn_alive = num_nh;
524         rt->rt_nh_size = nh_size;
525         rt->rt_via_offset = MPLS_NH_VIA_OFF(max_labels);
526 
527         return rt;
528 }
529 
530 static void mpls_rt_free(struct mpls_route *rt)
531 {
532         if (rt)
533                 kfree_rcu(rt, rt_rcu);
534 }
535 
536 static void mpls_notify_route(struct net *net, unsigned index,
537                               struct mpls_route *old, struct mpls_route *new,
538                               const struct nl_info *info)
539 {
540         struct nlmsghdr *nlh = info ? info->nlh : NULL;
541         unsigned portid = info ? info->portid : 0;
542         int event = new ? RTM_NEWROUTE : RTM_DELROUTE;
543         struct mpls_route *rt = new ? new : old;
544         unsigned nlm_flags = (old && new) ? NLM_F_REPLACE : 0;
545         /* Ignore reserved labels for now */
546         if (rt && (index >= MPLS_LABEL_FIRST_UNRESERVED))
547                 rtmsg_lfib(event, index, rt, nlh, net, portid, nlm_flags);
548 }
549 
550 static void mpls_route_update(struct net *net, unsigned index,
551                               struct mpls_route *new,
552                               const struct nl_info *info)
553 {
554         struct mpls_route __rcu **platform_label;
555         struct mpls_route *rt;
556 
557         ASSERT_RTNL();
558 
559         platform_label = rtnl_dereference(net->mpls.platform_label);
560         rt = rtnl_dereference(platform_label[index]);
561         rcu_assign_pointer(platform_label[index], new);
562 
563         mpls_notify_route(net, index, rt, new, info);
564 
565         /* If we removed a route free it now */
566         mpls_rt_free(rt);
567 }
568 
569 static unsigned find_free_label(struct net *net)
570 {
571         struct mpls_route __rcu **platform_label;
572         size_t platform_labels;
573         unsigned index;
574 
575         platform_label = rtnl_dereference(net->mpls.platform_label);
576         platform_labels = net->mpls.platform_labels;
577         for (index = MPLS_LABEL_FIRST_UNRESERVED; index < platform_labels;
578              index++) {
579                 if (!rtnl_dereference(platform_label[index]))
580                         return index;
581         }
582         return LABEL_NOT_SPECIFIED;
583 }
584 
585 #if IS_ENABLED(CONFIG_INET)
586 static struct net_device *inet_fib_lookup_dev(struct net *net,
587                                               const void *addr)
588 {
589         struct net_device *dev;
590         struct rtable *rt;
591         struct in_addr daddr;
592 
593         memcpy(&daddr, addr, sizeof(struct in_addr));
594         rt = ip_route_output(net, daddr.s_addr, 0, 0, 0);
595         if (IS_ERR(rt))
596                 return ERR_CAST(rt);
597 
598         dev = rt->dst.dev;
599         dev_hold(dev);
600 
601         ip_rt_put(rt);
602 
603         return dev;
604 }
605 #else
606 static struct net_device *inet_fib_lookup_dev(struct net *net,
607                                               const void *addr)
608 {
609         return ERR_PTR(-EAFNOSUPPORT);
610 }
611 #endif
612 
613 #if IS_ENABLED(CONFIG_IPV6)
614 static struct net_device *inet6_fib_lookup_dev(struct net *net,
615                                                const void *addr)
616 {
617         struct net_device *dev;
618         struct dst_entry *dst;
619         struct flowi6 fl6;
620 
621         if (!ipv6_stub)
622                 return ERR_PTR(-EAFNOSUPPORT);
623 
624         memset(&fl6, 0, sizeof(fl6));
625         memcpy(&fl6.daddr, addr, sizeof(struct in6_addr));
626         dst = ipv6_stub->ipv6_dst_lookup_flow(net, NULL, &fl6, NULL);
627         if (IS_ERR(dst))
628                 return ERR_CAST(dst);
629 
630         dev = dst->dev;
631         dev_hold(dev);
632         dst_release(dst);
633 
634         return dev;
635 }
636 #else
637 static struct net_device *inet6_fib_lookup_dev(struct net *net,
638                                                const void *addr)
639 {
640         return ERR_PTR(-EAFNOSUPPORT);
641 }
642 #endif
643 
644 static struct net_device *find_outdev(struct net *net,
645                                       struct mpls_route *rt,
646                                       struct mpls_nh *nh, int oif)
647 {
648         struct net_device *dev = NULL;
649 
650         if (!oif) {
651                 switch (nh->nh_via_table) {
652                 case NEIGH_ARP_TABLE:
653                         dev = inet_fib_lookup_dev(net, mpls_nh_via(rt, nh));
654                         break;
655                 case NEIGH_ND_TABLE:
656                         dev = inet6_fib_lookup_dev(net, mpls_nh_via(rt, nh));
657                         break;
658                 case NEIGH_LINK_TABLE:
659                         break;
660                 }
661         } else {
662                 dev = dev_get_by_index(net, oif);
663         }
664 
665         if (!dev)
666                 return ERR_PTR(-ENODEV);
667 
668         if (IS_ERR(dev))
669                 return dev;
670 
671         /* The caller is holding rtnl anyways, so release the dev reference */
672         dev_put(dev);
673 
674         return dev;
675 }
676 
677 static int mpls_nh_assign_dev(struct net *net, struct mpls_route *rt,
678                               struct mpls_nh *nh, int oif)
679 {
680         struct net_device *dev = NULL;
681         int err = -ENODEV;
682 
683         dev = find_outdev(net, rt, nh, oif);
684         if (IS_ERR(dev)) {
685                 err = PTR_ERR(dev);
686                 dev = NULL;
687                 goto errout;
688         }
689 
690         /* Ensure this is a supported device */
691         err = -EINVAL;
692         if (!mpls_dev_get(dev))
693                 goto errout;
694 
695         if ((nh->nh_via_table == NEIGH_LINK_TABLE) &&
696             (dev->addr_len != nh->nh_via_alen))
697                 goto errout;
698 
699         RCU_INIT_POINTER(nh->nh_dev, dev);
700 
701         if (!(dev->flags & IFF_UP)) {
702                 nh->nh_flags |= RTNH_F_DEAD;
703         } else {
704                 unsigned int flags;
705 
706                 flags = dev_get_flags(dev);
707                 if (!(flags & (IFF_RUNNING | IFF_LOWER_UP)))
708                         nh->nh_flags |= RTNH_F_LINKDOWN;
709         }
710 
711         return 0;
712 
713 errout:
714         return err;
715 }
716 
717 static int nla_get_via(const struct nlattr *nla, u8 *via_alen, u8 *via_table,
718                        u8 via_addr[], struct netlink_ext_ack *extack)
719 {
720         struct rtvia *via = nla_data(nla);
721         int err = -EINVAL;
722         int alen;
723 
724         if (nla_len(nla) < offsetof(struct rtvia, rtvia_addr)) {
725                 NL_SET_ERR_MSG_ATTR(extack, nla,
726                                     "Invalid attribute length for RTA_VIA");
727                 goto errout;
728         }
729         alen = nla_len(nla) -
730                         offsetof(struct rtvia, rtvia_addr);
731         if (alen > MAX_VIA_ALEN) {
732                 NL_SET_ERR_MSG_ATTR(extack, nla,
733                                     "Invalid address length for RTA_VIA");
734                 goto errout;
735         }
736 
737         /* Validate the address family */
738         switch (via->rtvia_family) {
739         case AF_PACKET:
740                 *via_table = NEIGH_LINK_TABLE;
741                 break;
742         case AF_INET:
743                 *via_table = NEIGH_ARP_TABLE;
744                 if (alen != 4)
745                         goto errout;
746                 break;
747         case AF_INET6:
748                 *via_table = NEIGH_ND_TABLE;
749                 if (alen != 16)
750                         goto errout;
751                 break;
752         default:
753                 /* Unsupported address family */
754                 goto errout;
755         }
756 
757         memcpy(via_addr, via->rtvia_addr, alen);
758         *via_alen = alen;
759         err = 0;
760 
761 errout:
762         return err;
763 }
764 
765 static int mpls_nh_build_from_cfg(struct mpls_route_config *cfg,
766                                   struct mpls_route *rt)
767 {
768         struct net *net = cfg->rc_nlinfo.nl_net;
769         struct mpls_nh *nh = rt->rt_nh;
770         int err;
771         int i;
772 
773         if (!nh)
774                 return -ENOMEM;
775 
776         nh->nh_labels = cfg->rc_output_labels;
777         for (i = 0; i < nh->nh_labels; i++)
778                 nh->nh_label[i] = cfg->rc_output_label[i];
779 
780         nh->nh_via_table = cfg->rc_via_table;
781         memcpy(__mpls_nh_via(rt, nh), cfg->rc_via, cfg->rc_via_alen);
782         nh->nh_via_alen = cfg->rc_via_alen;
783 
784         err = mpls_nh_assign_dev(net, rt, nh, cfg->rc_ifindex);
785         if (err)
786                 goto errout;
787 
788         if (nh->nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN))
789                 rt->rt_nhn_alive--;
790 
791         return 0;
792 
793 errout:
794         return err;
795 }
796 
797 static int mpls_nh_build(struct net *net, struct mpls_route *rt,
798                          struct mpls_nh *nh, int oif, struct nlattr *via,
799                          struct nlattr *newdst, u8 max_labels,
800                          struct netlink_ext_ack *extack)
801 {
802         int err = -ENOMEM;
803 
804         if (!nh)
805                 goto errout;
806 
807         if (newdst) {
808                 err = nla_get_labels(newdst, max_labels, &nh->nh_labels,
809                                      nh->nh_label, extack);
810                 if (err)
811                         goto errout;
812         }
813 
814         if (via) {
815                 err = nla_get_via(via, &nh->nh_via_alen, &nh->nh_via_table,
816                                   __mpls_nh_via(rt, nh), extack);
817                 if (err)
818                         goto errout;
819         } else {
820                 nh->nh_via_table = MPLS_NEIGH_TABLE_UNSPEC;
821         }
822 
823         err = mpls_nh_assign_dev(net, rt, nh, oif);
824         if (err)
825                 goto errout;
826 
827         return 0;
828 
829 errout:
830         return err;
831 }
832 
833 static u8 mpls_count_nexthops(struct rtnexthop *rtnh, int len,
834                               u8 cfg_via_alen, u8 *max_via_alen,
835                               u8 *max_labels)
836 {
837         int remaining = len;
838         u8 nhs = 0;
839 
840         *max_via_alen = 0;
841         *max_labels = 0;
842 
843         while (rtnh_ok(rtnh, remaining)) {
844                 struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
845                 int attrlen;
846                 u8 n_labels = 0;
847 
848                 attrlen = rtnh_attrlen(rtnh);
849                 nla = nla_find(attrs, attrlen, RTA_VIA);
850                 if (nla && nla_len(nla) >=
851                     offsetof(struct rtvia, rtvia_addr)) {
852                         int via_alen = nla_len(nla) -
853                                 offsetof(struct rtvia, rtvia_addr);
854 
855                         if (via_alen <= MAX_VIA_ALEN)
856                                 *max_via_alen = max_t(u16, *max_via_alen,
857                                                       via_alen);
858                 }
859 
860                 nla = nla_find(attrs, attrlen, RTA_NEWDST);
861                 if (nla &&
862                     nla_get_labels(nla, MAX_NEW_LABELS, &n_labels,
863                                    NULL, NULL) != 0)
864                         return 0;
865 
866                 *max_labels = max_t(u8, *max_labels, n_labels);
867 
868                 /* number of nexthops is tracked by a u8.
869                  * Check for overflow.
870                  */
871                 if (nhs == 255)
872                         return 0;
873                 nhs++;
874 
875                 rtnh = rtnh_next(rtnh, &remaining);
876         }
877 
878         /* leftover implies invalid nexthop configuration, discard it */
879         return remaining > 0 ? 0 : nhs;
880 }
881 
882 static int mpls_nh_build_multi(struct mpls_route_config *cfg,
883                                struct mpls_route *rt, u8 max_labels,
884                                struct netlink_ext_ack *extack)
885 {
886         struct rtnexthop *rtnh = cfg->rc_mp;
887         struct nlattr *nla_via, *nla_newdst;
888         int remaining = cfg->rc_mp_len;
889         int err = 0;
890         u8 nhs = 0;
891 
892         change_nexthops(rt) {
893                 int attrlen;
894 
895                 nla_via = NULL;
896                 nla_newdst = NULL;
897 
898                 err = -EINVAL;
899                 if (!rtnh_ok(rtnh, remaining))
900                         goto errout;
901 
902                 /* neither weighted multipath nor any flags
903                  * are supported
904                  */
905                 if (rtnh->rtnh_hops || rtnh->rtnh_flags)
906                         goto errout;
907 
908                 attrlen = rtnh_attrlen(rtnh);
909                 if (attrlen > 0) {
910                         struct nlattr *attrs = rtnh_attrs(rtnh);
911 
912                         nla_via = nla_find(attrs, attrlen, RTA_VIA);
913                         nla_newdst = nla_find(attrs, attrlen, RTA_NEWDST);
914                 }
915 
916                 err = mpls_nh_build(cfg->rc_nlinfo.nl_net, rt, nh,
917                                     rtnh->rtnh_ifindex, nla_via, nla_newdst,
918                                     max_labels, extack);
919                 if (err)
920                         goto errout;
921 
922                 if (nh->nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN))
923                         rt->rt_nhn_alive--;
924 
925                 rtnh = rtnh_next(rtnh, &remaining);
926                 nhs++;
927         } endfor_nexthops(rt);
928 
929         rt->rt_nhn = nhs;
930 
931         return 0;
932 
933 errout:
934         return err;
935 }
936 
937 static bool mpls_label_ok(struct net *net, unsigned int *index,
938                           struct netlink_ext_ack *extack)
939 {
940         bool is_ok = true;
941 
942         /* Reserved labels may not be set */
943         if (*index < MPLS_LABEL_FIRST_UNRESERVED) {
944                 NL_SET_ERR_MSG(extack,
945                                "Invalid label - must be MPLS_LABEL_FIRST_UNRESERVED or higher");
946                 is_ok = false;
947         }
948 
949         /* The full 20 bit range may not be supported. */
950         if (is_ok && *index >= net->mpls.platform_labels) {
951                 NL_SET_ERR_MSG(extack,
952                                "Label >= configured maximum in platform_labels");
953                 is_ok = false;
954         }
955 
956         *index = array_index_nospec(*index, net->mpls.platform_labels);
957         return is_ok;
958 }
959 
960 static int mpls_route_add(struct mpls_route_config *cfg,
961                           struct netlink_ext_ack *extack)
962 {
963         struct mpls_route __rcu **platform_label;
964         struct net *net = cfg->rc_nlinfo.nl_net;
965         struct mpls_route *rt, *old;
966         int err = -EINVAL;
967         u8 max_via_alen;
968         unsigned index;
969         u8 max_labels;
970         u8 nhs;
971 
972         index = cfg->rc_label;
973 
974         /* If a label was not specified during insert pick one */
975         if ((index == LABEL_NOT_SPECIFIED) &&
976             (cfg->rc_nlflags & NLM_F_CREATE)) {
977                 index = find_free_label(net);
978         }
979 
980         if (!mpls_label_ok(net, &index, extack))
981                 goto errout;
982 
983         /* Append makes no sense with mpls */
984         err = -EOPNOTSUPP;
985         if (cfg->rc_nlflags & NLM_F_APPEND) {
986                 NL_SET_ERR_MSG(extack, "MPLS does not support route append");
987                 goto errout;
988         }
989 
990         err = -EEXIST;
991         platform_label = rtnl_dereference(net->mpls.platform_label);
992         old = rtnl_dereference(platform_label[index]);
993         if ((cfg->rc_nlflags & NLM_F_EXCL) && old)
994                 goto errout;
995 
996         err = -EEXIST;
997         if (!(cfg->rc_nlflags & NLM_F_REPLACE) && old)
998                 goto errout;
999 
1000         err = -ENOENT;
1001         if (!(cfg->rc_nlflags & NLM_F_CREATE) && !old)
1002                 goto errout;
1003 
1004         err = -EINVAL;
1005         if (cfg->rc_mp) {
1006                 nhs = mpls_count_nexthops(cfg->rc_mp, cfg->rc_mp_len,
1007                                           cfg->rc_via_alen, &max_via_alen,
1008                                           &max_labels);
1009         } else {
1010                 max_via_alen = cfg->rc_via_alen;
1011                 max_labels = cfg->rc_output_labels;
1012                 nhs = 1;
1013         }
1014 
1015         if (nhs == 0) {
1016                 NL_SET_ERR_MSG(extack, "Route does not contain a nexthop");
1017                 goto errout;
1018         }
1019 
1020         err = -ENOMEM;
1021         rt = mpls_rt_alloc(nhs, max_via_alen, max_labels);
1022         if (IS_ERR(rt)) {
1023                 err = PTR_ERR(rt);
1024                 goto errout;
1025         }
1026 
1027         rt->rt_protocol = cfg->rc_protocol;
1028         rt->rt_payload_type = cfg->rc_payload_type;
1029         rt->rt_ttl_propagate = cfg->rc_ttl_propagate;
1030 
1031         if (cfg->rc_mp)
1032                 err = mpls_nh_build_multi(cfg, rt, max_labels, extack);
1033         else
1034                 err = mpls_nh_build_from_cfg(cfg, rt);
1035         if (err)
1036                 goto freert;
1037 
1038         mpls_route_update(net, index, rt, &cfg->rc_nlinfo);
1039 
1040         return 0;
1041 
1042 freert:
1043         mpls_rt_free(rt);
1044 errout:
1045         return err;
1046 }
1047 
1048 static int mpls_route_del(struct mpls_route_config *cfg,
1049                           struct netlink_ext_ack *extack)
1050 {
1051         struct net *net = cfg->rc_nlinfo.nl_net;
1052         unsigned index;
1053         int err = -EINVAL;
1054 
1055         index = cfg->rc_label;
1056 
1057         if (!mpls_label_ok(net, &index, extack))
1058                 goto errout;
1059 
1060         mpls_route_update(net, index, NULL, &cfg->rc_nlinfo);
1061 
1062         err = 0;
1063 errout:
1064         return err;
1065 }
1066 
1067 static void mpls_get_stats(struct mpls_dev *mdev,
1068                            struct mpls_link_stats *stats)
1069 {
1070         struct mpls_pcpu_stats *p;
1071         int i;
1072 
1073         memset(stats, 0, sizeof(*stats));
1074 
1075         for_each_possible_cpu(i) {
1076                 struct mpls_link_stats local;
1077                 unsigned int start;
1078 
1079                 p = per_cpu_ptr(mdev->stats, i);
1080                 do {
1081                         start = u64_stats_fetch_begin(&p->syncp);
1082                         local = p->stats;
1083                 } while (u64_stats_fetch_retry(&p->syncp, start));
1084 
1085                 stats->rx_packets       += local.rx_packets;
1086                 stats->rx_bytes         += local.rx_bytes;
1087                 stats->tx_packets       += local.tx_packets;
1088                 stats->tx_bytes         += local.tx_bytes;
1089                 stats->rx_errors        += local.rx_errors;
1090                 stats->tx_errors        += local.tx_errors;
1091                 stats->rx_dropped       += local.rx_dropped;
1092                 stats->tx_dropped       += local.tx_dropped;
1093                 stats->rx_noroute       += local.rx_noroute;
1094         }
1095 }
1096 
1097 static int mpls_fill_stats_af(struct sk_buff *skb,
1098                               const struct net_device *dev)
1099 {
1100         struct mpls_link_stats *stats;
1101         struct mpls_dev *mdev;
1102         struct nlattr *nla;
1103 
1104         mdev = mpls_dev_get(dev);
1105         if (!mdev)
1106                 return -ENODATA;
1107 
1108         nla = nla_reserve_64bit(skb, MPLS_STATS_LINK,
1109                                 sizeof(struct mpls_link_stats),
1110                                 MPLS_STATS_UNSPEC);
1111         if (!nla)
1112                 return -EMSGSIZE;
1113 
1114         stats = nla_data(nla);
1115         mpls_get_stats(mdev, stats);
1116 
1117         return 0;
1118 }
1119 
1120 static size_t mpls_get_stats_af_size(const struct net_device *dev)
1121 {
1122         struct mpls_dev *mdev;
1123 
1124         mdev = mpls_dev_get(dev);
1125         if (!mdev)
1126                 return 0;
1127 
1128         return nla_total_size_64bit(sizeof(struct mpls_link_stats));
1129 }
1130 
1131 static int mpls_netconf_fill_devconf(struct sk_buff *skb, struct mpls_dev *mdev,
1132                                      u32 portid, u32 seq, int event,
1133                                      unsigned int flags, int type)
1134 {
1135         struct nlmsghdr  *nlh;
1136         struct netconfmsg *ncm;
1137         bool all = false;
1138 
1139         nlh = nlmsg_put(skb, portid, seq, event, sizeof(struct netconfmsg),
1140                         flags);
1141         if (!nlh)
1142                 return -EMSGSIZE;
1143 
1144         if (type == NETCONFA_ALL)
1145                 all = true;
1146 
1147         ncm = nlmsg_data(nlh);
1148         ncm->ncm_family = AF_MPLS;
1149 
1150         if (nla_put_s32(skb, NETCONFA_IFINDEX, mdev->dev->ifindex) < 0)
1151                 goto nla_put_failure;
1152 
1153         if ((all || type == NETCONFA_INPUT) &&
1154             nla_put_s32(skb, NETCONFA_INPUT,
1155                         mdev->input_enabled) < 0)
1156                 goto nla_put_failure;
1157 
1158         nlmsg_end(skb, nlh);
1159         return 0;
1160 
1161 nla_put_failure:
1162         nlmsg_cancel(skb, nlh);
1163         return -EMSGSIZE;
1164 }
1165 
1166 static int mpls_netconf_msgsize_devconf(int type)
1167 {
1168         int size = NLMSG_ALIGN(sizeof(struct netconfmsg))
1169                         + nla_total_size(4); /* NETCONFA_IFINDEX */
1170         bool all = false;
1171 
1172         if (type == NETCONFA_ALL)
1173                 all = true;
1174 
1175         if (all || type == NETCONFA_INPUT)
1176                 size += nla_total_size(4);
1177 
1178         return size;
1179 }
1180 
1181 static void mpls_netconf_notify_devconf(struct net *net, int event,
1182                                         int type, struct mpls_dev *mdev)
1183 {
1184         struct sk_buff *skb;
1185         int err = -ENOBUFS;
1186 
1187         skb = nlmsg_new(mpls_netconf_msgsize_devconf(type), GFP_KERNEL);
1188         if (!skb)
1189                 goto errout;
1190 
1191         err = mpls_netconf_fill_devconf(skb, mdev, 0, 0, event, 0, type);
1192         if (err < 0) {
1193                 /* -EMSGSIZE implies BUG in mpls_netconf_msgsize_devconf() */
1194                 WARN_ON(err == -EMSGSIZE);
1195                 kfree_skb(skb);
1196                 goto errout;
1197         }
1198 
1199         rtnl_notify(skb, net, 0, RTNLGRP_MPLS_NETCONF, NULL, GFP_KERNEL);
1200         return;
1201 errout:
1202         if (err < 0)
1203                 rtnl_set_sk_err(net, RTNLGRP_MPLS_NETCONF, err);
1204 }
1205 
1206 static const struct nla_policy devconf_mpls_policy[NETCONFA_MAX + 1] = {
1207         [NETCONFA_IFINDEX]      = { .len = sizeof(int) },
1208 };
1209 
1210 static int mpls_netconf_valid_get_req(struct sk_buff *skb,
1211                                       const struct nlmsghdr *nlh,
1212                                       struct nlattr **tb,
1213                                       struct netlink_ext_ack *extack)
1214 {
1215         int i, err;
1216 
1217         if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(struct netconfmsg))) {
1218                 NL_SET_ERR_MSG_MOD(extack,
1219                                    "Invalid header for netconf get request");
1220                 return -EINVAL;
1221         }
1222 
1223         if (!netlink_strict_get_check(skb))
1224                 return nlmsg_parse_deprecated(nlh, sizeof(struct netconfmsg),
1225                                               tb, NETCONFA_MAX,
1226                                               devconf_mpls_policy, extack);
1227 
1228         err = nlmsg_parse_deprecated_strict(nlh, sizeof(struct netconfmsg),
1229                                             tb, NETCONFA_MAX,
1230                                             devconf_mpls_policy, extack);
1231         if (err)
1232                 return err;
1233 
1234         for (i = 0; i <= NETCONFA_MAX; i++) {
1235                 if (!tb[i])
1236                         continue;
1237 
1238                 switch (i) {
1239                 case NETCONFA_IFINDEX:
1240                         break;
1241                 default:
1242                         NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in netconf get request");
1243                         return -EINVAL;
1244                 }
1245         }
1246 
1247         return 0;
1248 }
1249 
1250 static int mpls_netconf_get_devconf(struct sk_buff *in_skb,
1251                                     struct nlmsghdr *nlh,
1252                                     struct netlink_ext_ack *extack)
1253 {
1254         struct net *net = sock_net(in_skb->sk);
1255         struct nlattr *tb[NETCONFA_MAX + 1];
1256         struct net_device *dev;
1257         struct mpls_dev *mdev;
1258         struct sk_buff *skb;
1259         int ifindex;
1260         int err;
1261 
1262         err = mpls_netconf_valid_get_req(in_skb, nlh, tb, extack);
1263         if (err < 0)
1264                 goto errout;
1265 
1266         err = -EINVAL;
1267         if (!tb[NETCONFA_IFINDEX])
1268                 goto errout;
1269 
1270         ifindex = nla_get_s32(tb[NETCONFA_IFINDEX]);
1271         dev = __dev_get_by_index(net, ifindex);
1272         if (!dev)
1273                 goto errout;
1274 
1275         mdev = mpls_dev_get(dev);
1276         if (!mdev)
1277                 goto errout;
1278 
1279         err = -ENOBUFS;
1280         skb = nlmsg_new(mpls_netconf_msgsize_devconf(NETCONFA_ALL), GFP_KERNEL);
1281         if (!skb)
1282                 goto errout;
1283 
1284         err = mpls_netconf_fill_devconf(skb, mdev,
1285                                         NETLINK_CB(in_skb).portid,
1286                                         nlh->nlmsg_seq, RTM_NEWNETCONF, 0,
1287                                         NETCONFA_ALL);
1288         if (err < 0) {
1289                 /* -EMSGSIZE implies BUG in mpls_netconf_msgsize_devconf() */
1290                 WARN_ON(err == -EMSGSIZE);
1291                 kfree_skb(skb);
1292                 goto errout;
1293         }
1294         err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
1295 errout:
1296         return err;
1297 }
1298 
1299 static int mpls_netconf_dump_devconf(struct sk_buff *skb,
1300                                      struct netlink_callback *cb)
1301 {
1302         const struct nlmsghdr *nlh = cb->nlh;
1303         struct net *net = sock_net(skb->sk);
1304         struct hlist_head *head;
1305         struct net_device *dev;
1306         struct mpls_dev *mdev;
1307         int idx, s_idx;
1308         int h, s_h;
1309 
1310         if (cb->strict_check) {
1311                 struct netlink_ext_ack *extack = cb->extack;
1312                 struct netconfmsg *ncm;
1313 
1314                 if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*ncm))) {
1315                         NL_SET_ERR_MSG_MOD(extack, "Invalid header for netconf dump request");
1316                         return -EINVAL;
1317                 }
1318 
1319                 if (nlmsg_attrlen(nlh, sizeof(*ncm))) {
1320                         NL_SET_ERR_MSG_MOD(extack, "Invalid data after header in netconf dump request");
1321                         return -EINVAL;
1322                 }
1323         }
1324 
1325         s_h = cb->args[0];
1326         s_idx = idx = cb->args[1];
1327 
1328         for (h = s_h; h < NETDEV_HASHENTRIES; h++, s_idx = 0) {
1329                 idx = 0;
1330                 head = &net->dev_index_head[h];
1331                 rcu_read_lock();
1332                 cb->seq = net->dev_base_seq;
1333                 hlist_for_each_entry_rcu(dev, head, index_hlist) {
1334                         if (idx < s_idx)
1335                                 goto cont;
1336                         mdev = mpls_dev_get(dev);
1337                         if (!mdev)
1338                                 goto cont;
1339                         if (mpls_netconf_fill_devconf(skb, mdev,
1340                                                       NETLINK_CB(cb->skb).portid,
1341                                                       nlh->nlmsg_seq,
1342                                                       RTM_NEWNETCONF,
1343                                                       NLM_F_MULTI,
1344                                                       NETCONFA_ALL) < 0) {
1345                                 rcu_read_unlock();
1346                                 goto done;
1347                         }
1348                         nl_dump_check_consistent(cb, nlmsg_hdr(skb));
1349 cont:
1350                         idx++;
1351                 }
1352                 rcu_read_unlock();
1353         }
1354 done:
1355         cb->args[0] = h;
1356         cb->args[1] = idx;
1357 
1358         return skb->len;
1359 }
1360 
1361 #define MPLS_PERDEV_SYSCTL_OFFSET(field)        \
1362         (&((struct mpls_dev *)0)->field)
1363 
1364 static int mpls_conf_proc(struct ctl_table *ctl, int write,
1365                           void __user *buffer,
1366                           size_t *lenp, loff_t *ppos)
1367 {
1368         int oval = *(int *)ctl->data;
1369         int ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
1370 
1371         if (write) {
1372                 struct mpls_dev *mdev = ctl->extra1;
1373                 int i = (int *)ctl->data - (int *)mdev;
1374                 struct net *net = ctl->extra2;
1375                 int val = *(int *)ctl->data;
1376 
1377                 if (i == offsetof(struct mpls_dev, input_enabled) &&
1378                     val != oval) {
1379                         mpls_netconf_notify_devconf(net, RTM_NEWNETCONF,
1380                                                     NETCONFA_INPUT, mdev);
1381                 }
1382         }
1383 
1384         return ret;
1385 }
1386 
1387 static const struct ctl_table mpls_dev_table[] = {
1388         {
1389                 .procname       = "input",
1390                 .maxlen         = sizeof(int),
1391                 .mode           = 0644,
1392                 .proc_handler   = mpls_conf_proc,
1393                 .data           = MPLS_PERDEV_SYSCTL_OFFSET(input_enabled),
1394         },
1395         { }
1396 };
1397 
1398 static int mpls_dev_sysctl_register(struct net_device *dev,
1399                                     struct mpls_dev *mdev)
1400 {
1401         char path[sizeof("net/mpls/conf/") + IFNAMSIZ];
1402         struct net *net = dev_net(dev);
1403         struct ctl_table *table;
1404         int i;
1405 
1406         table = kmemdup(&mpls_dev_table, sizeof(mpls_dev_table), GFP_KERNEL);
1407         if (!table)
1408                 goto out;
1409 
1410         /* Table data contains only offsets relative to the base of
1411          * the mdev at this point, so make them absolute.
1412          */
1413         for (i = 0; i < ARRAY_SIZE(mpls_dev_table); i++) {
1414                 table[i].data = (char *)mdev + (uintptr_t)table[i].data;
1415                 table[i].extra1 = mdev;
1416                 table[i].extra2 = net;
1417         }
1418 
1419         snprintf(path, sizeof(path), "net/mpls/conf/%s", dev->name);
1420 
1421         mdev->sysctl = register_net_sysctl(net, path, table);
1422         if (!mdev->sysctl)
1423                 goto free;
1424 
1425         mpls_netconf_notify_devconf(net, RTM_NEWNETCONF, NETCONFA_ALL, mdev);
1426         return 0;
1427 
1428 free:
1429         kfree(table);
1430 out:
1431         return -ENOBUFS;
1432 }
1433 
1434 static void mpls_dev_sysctl_unregister(struct net_device *dev,
1435                                        struct mpls_dev *mdev)
1436 {
1437         struct net *net = dev_net(dev);
1438         struct ctl_table *table;
1439 
1440         table = mdev->sysctl->ctl_table_arg;
1441         unregister_net_sysctl_table(mdev->sysctl);
1442         kfree(table);
1443 
1444         mpls_netconf_notify_devconf(net, RTM_DELNETCONF, 0, mdev);
1445 }
1446 
1447 static struct mpls_dev *mpls_add_dev(struct net_device *dev)
1448 {
1449         struct mpls_dev *mdev;
1450         int err = -ENOMEM;
1451         int i;
1452 
1453         ASSERT_RTNL();
1454 
1455         mdev = kzalloc(sizeof(*mdev), GFP_KERNEL);
1456         if (!mdev)
1457                 return ERR_PTR(err);
1458 
1459         mdev->stats = alloc_percpu(struct mpls_pcpu_stats);
1460         if (!mdev->stats)
1461                 goto free;
1462 
1463         for_each_possible_cpu(i) {
1464                 struct mpls_pcpu_stats *mpls_stats;
1465 
1466                 mpls_stats = per_cpu_ptr(mdev->stats, i);
1467                 u64_stats_init(&mpls_stats->syncp);
1468         }
1469 
1470         mdev->dev = dev;
1471 
1472         err = mpls_dev_sysctl_register(dev, mdev);
1473         if (err)
1474                 goto free;
1475 
1476         rcu_assign_pointer(dev->mpls_ptr, mdev);
1477 
1478         return mdev;
1479 
1480 free:
1481         free_percpu(mdev->stats);
1482         kfree(mdev);
1483         return ERR_PTR(err);
1484 }
1485 
1486 static void mpls_dev_destroy_rcu(struct rcu_head *head)
1487 {
1488         struct mpls_dev *mdev = container_of(head, struct mpls_dev, rcu);
1489 
1490         free_percpu(mdev->stats);
1491         kfree(mdev);
1492 }
1493 
1494 static void mpls_ifdown(struct net_device *dev, int event)
1495 {
1496         struct mpls_route __rcu **platform_label;
1497         struct net *net = dev_net(dev);
1498         u8 alive, deleted;
1499         unsigned index;
1500 
1501         platform_label = rtnl_dereference(net->mpls.platform_label);
1502         for (index = 0; index < net->mpls.platform_labels; index++) {
1503                 struct mpls_route *rt = rtnl_dereference(platform_label[index]);
1504 
1505                 if (!rt)
1506                         continue;
1507 
1508                 alive = 0;
1509                 deleted = 0;
1510                 change_nexthops(rt) {
1511                         unsigned int nh_flags = nh->nh_flags;
1512 
1513                         if (rtnl_dereference(nh->nh_dev) != dev)
1514                                 goto next;
1515 
1516                         switch (event) {
1517                         case NETDEV_DOWN:
1518                         case NETDEV_UNREGISTER:
1519                                 nh_flags |= RTNH_F_DEAD;
1520                                 /* fall through */
1521                         case NETDEV_CHANGE:
1522                                 nh_flags |= RTNH_F_LINKDOWN;
1523                                 break;
1524                         }
1525                         if (event == NETDEV_UNREGISTER)
1526                                 RCU_INIT_POINTER(nh->nh_dev, NULL);
1527 
1528                         if (nh->nh_flags != nh_flags)
1529                                 WRITE_ONCE(nh->nh_flags, nh_flags);
1530 next:
1531                         if (!(nh_flags & (RTNH_F_DEAD | RTNH_F_LINKDOWN)))
1532                                 alive++;
1533                         if (!rtnl_dereference(nh->nh_dev))
1534                                 deleted++;
1535                 } endfor_nexthops(rt);
1536 
1537                 WRITE_ONCE(rt->rt_nhn_alive, alive);
1538 
1539                 /* if there are no more nexthops, delete the route */
1540                 if (event == NETDEV_UNREGISTER && deleted == rt->rt_nhn)
1541                         mpls_route_update(net, index, NULL, NULL);
1542         }
1543 }
1544 
1545 static void mpls_ifup(struct net_device *dev, unsigned int flags)
1546 {
1547         struct mpls_route __rcu **platform_label;
1548         struct net *net = dev_net(dev);
1549         unsigned index;
1550         u8 alive;
1551 
1552         platform_label = rtnl_dereference(net->mpls.platform_label);
1553         for (index = 0; index < net->mpls.platform_labels; index++) {
1554                 struct mpls_route *rt = rtnl_dereference(platform_label[index]);
1555 
1556                 if (!rt)
1557                         continue;
1558 
1559                 alive = 0;
1560                 change_nexthops(rt) {
1561                         unsigned int nh_flags = nh->nh_flags;
1562                         struct net_device *nh_dev =
1563                                 rtnl_dereference(nh->nh_dev);
1564 
1565                         if (!(nh_flags & flags)) {
1566                                 alive++;
1567                                 continue;
1568                         }
1569                         if (nh_dev != dev)
1570                                 continue;
1571                         alive++;
1572                         nh_flags &= ~flags;
1573                         WRITE_ONCE(nh->nh_flags, nh_flags);
1574                 } endfor_nexthops(rt);
1575 
1576                 WRITE_ONCE(rt->rt_nhn_alive, alive);
1577         }
1578 }
1579 
1580 static int mpls_dev_notify(struct notifier_block *this, unsigned long event,
1581                            void *ptr)
1582 {
1583         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
1584         struct mpls_dev *mdev;
1585         unsigned int flags;
1586 
1587         if (event == NETDEV_REGISTER) {
1588 
1589                 /* For now just support Ethernet, IPGRE, IP6GRE, SIT and
1590                  * IPIP devices
1591                  */
1592                 if (dev->type == ARPHRD_ETHER ||
1593                     dev->type == ARPHRD_LOOPBACK ||
1594                     dev->type == ARPHRD_IPGRE ||
1595                     dev->type == ARPHRD_IP6GRE ||
1596                     dev->type == ARPHRD_SIT ||
1597                     dev->type == ARPHRD_TUNNEL) {
1598                         mdev = mpls_add_dev(dev);
1599                         if (IS_ERR(mdev))
1600                                 return notifier_from_errno(PTR_ERR(mdev));
1601                 }
1602                 return NOTIFY_OK;
1603         }
1604 
1605         mdev = mpls_dev_get(dev);
1606         if (!mdev)
1607                 return NOTIFY_OK;
1608 
1609         switch (event) {
1610         case NETDEV_DOWN:
1611                 mpls_ifdown(dev, event);
1612                 break;
1613         case NETDEV_UP:
1614                 flags = dev_get_flags(dev);
1615                 if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1616                         mpls_ifup(dev, RTNH_F_DEAD | RTNH_F_LINKDOWN);
1617                 else
1618                         mpls_ifup(dev, RTNH_F_DEAD);
1619                 break;
1620         case NETDEV_CHANGE:
1621                 flags = dev_get_flags(dev);
1622                 if (flags & (IFF_RUNNING | IFF_LOWER_UP))
1623                         mpls_ifup(dev, RTNH_F_DEAD | RTNH_F_LINKDOWN);
1624                 else
1625                         mpls_ifdown(dev, event);
1626                 break;
1627         case NETDEV_UNREGISTER:
1628                 mpls_ifdown(dev, event);
1629                 mdev = mpls_dev_get(dev);
1630                 if (mdev) {
1631                         mpls_dev_sysctl_unregister(dev, mdev);
1632                         RCU_INIT_POINTER(dev->mpls_ptr, NULL);
1633                         call_rcu(&mdev->rcu, mpls_dev_destroy_rcu);
1634                 }
1635                 break;
1636         case NETDEV_CHANGENAME:
1637                 mdev = mpls_dev_get(dev);
1638                 if (mdev) {
1639                         int err;
1640 
1641                         mpls_dev_sysctl_unregister(dev, mdev);
1642                         err = mpls_dev_sysctl_register(dev, mdev);
1643                         if (err)
1644                                 return notifier_from_errno(err);
1645                 }
1646                 break;
1647         }
1648         return NOTIFY_OK;
1649 }
1650 
1651 static struct notifier_block mpls_dev_notifier = {
1652         .notifier_call = mpls_dev_notify,
1653 };
1654 
1655 static int nla_put_via(struct sk_buff *skb,
1656                        u8 table, const void *addr, int alen)
1657 {
1658         static const int table_to_family[NEIGH_NR_TABLES + 1] = {
1659                 AF_INET, AF_INET6, AF_DECnet, AF_PACKET,
1660         };
1661         struct nlattr *nla;
1662         struct rtvia *via;
1663         int family = AF_UNSPEC;
1664 
1665         nla = nla_reserve(skb, RTA_VIA, alen + 2);
1666         if (!nla)
1667                 return -EMSGSIZE;
1668 
1669         if (table <= NEIGH_NR_TABLES)
1670                 family = table_to_family[table];
1671 
1672         via = nla_data(nla);
1673         via->rtvia_family = family;
1674         memcpy(via->rtvia_addr, addr, alen);
1675         return 0;
1676 }
1677 
1678 int nla_put_labels(struct sk_buff *skb, int attrtype,
1679                    u8 labels, const u32 label[])
1680 {
1681         struct nlattr *nla;
1682         struct mpls_shim_hdr *nla_label;
1683         bool bos;
1684         int i;
1685         nla = nla_reserve(skb, attrtype, labels*4);
1686         if (!nla)
1687                 return -EMSGSIZE;
1688 
1689         nla_label = nla_data(nla);
1690         bos = true;
1691         for (i = labels - 1; i >= 0; i--) {
1692                 nla_label[i] = mpls_entry_encode(label[i], 0, 0, bos);
1693                 bos = false;
1694         }
1695 
1696         return 0;
1697 }
1698 EXPORT_SYMBOL_GPL(nla_put_labels);
1699 
1700 int nla_get_labels(const struct nlattr *nla, u8 max_labels, u8 *labels,
1701                    u32 label[], struct netlink_ext_ack *extack)
1702 {
1703         unsigned len = nla_len(nla);
1704         struct mpls_shim_hdr *nla_label;
1705         u8 nla_labels;
1706         bool bos;
1707         int i;
1708 
1709         /* len needs to be an even multiple of 4 (the label size). Number
1710          * of labels is a u8 so check for overflow.
1711          */
1712         if (len & 3 || len / 4 > 255) {
1713                 NL_SET_ERR_MSG_ATTR(extack, nla,
1714                                     "Invalid length for labels attribute");
1715                 return -EINVAL;
1716         }
1717 
1718         /* Limit the number of new labels allowed */
1719         nla_labels = len/4;
1720         if (nla_labels > max_labels) {
1721                 NL_SET_ERR_MSG(extack, "Too many labels");
1722                 return -EINVAL;
1723         }
1724 
1725         /* when label == NULL, caller wants number of labels */
1726         if (!label)
1727                 goto out;
1728 
1729         nla_label = nla_data(nla);
1730         bos = true;
1731         for (i = nla_labels - 1; i >= 0; i--, bos = false) {
1732                 struct mpls_entry_decoded dec;
1733                 dec = mpls_entry_decode(nla_label + i);
1734 
1735                 /* Ensure the bottom of stack flag is properly set
1736                  * and ttl and tc are both clear.
1737                  */
1738                 if (dec.ttl) {
1739                         NL_SET_ERR_MSG_ATTR(extack, nla,
1740                                             "TTL in label must be 0");
1741                         return -EINVAL;
1742                 }
1743 
1744                 if (dec.tc) {
1745                         NL_SET_ERR_MSG_ATTR(extack, nla,
1746                                             "Traffic class in label must be 0");
1747                         return -EINVAL;
1748                 }
1749 
1750                 if (dec.bos != bos) {
1751                         NL_SET_BAD_ATTR(extack, nla);
1752                         if (bos) {
1753                                 NL_SET_ERR_MSG(extack,
1754                                                "BOS bit must be set in first label");
1755                         } else {
1756                                 NL_SET_ERR_MSG(extack,
1757                                                "BOS bit can only be set in first label");
1758                         }
1759                         return -EINVAL;
1760                 }
1761 
1762                 switch (dec.label) {
1763                 case MPLS_LABEL_IMPLNULL:
1764                         /* RFC3032: This is a label that an LSR may
1765                          * assign and distribute, but which never
1766                          * actually appears in the encapsulation.
1767                          */
1768                         NL_SET_ERR_MSG_ATTR(extack, nla,
1769                                             "Implicit NULL Label (3) can not be used in encapsulation");
1770                         return -EINVAL;
1771                 }
1772 
1773                 label[i] = dec.label;
1774         }
1775 out:
1776         *labels = nla_labels;
1777         return 0;
1778 }
1779 EXPORT_SYMBOL_GPL(nla_get_labels);
1780 
1781 static int rtm_to_route_config(struct sk_buff *skb,
1782                                struct nlmsghdr *nlh,
1783                                struct mpls_route_config *cfg,
1784                                struct netlink_ext_ack *extack)
1785 {
1786         struct rtmsg *rtm;
1787         struct nlattr *tb[RTA_MAX+1];
1788         int index;
1789         int err;
1790 
1791         err = nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
1792                                      rtm_mpls_policy, extack);
1793         if (err < 0)
1794                 goto errout;
1795 
1796         err = -EINVAL;
1797         rtm = nlmsg_data(nlh);
1798 
1799         if (rtm->rtm_family != AF_MPLS) {
1800                 NL_SET_ERR_MSG(extack, "Invalid address family in rtmsg");
1801                 goto errout;
1802         }
1803         if (rtm->rtm_dst_len != 20) {
1804                 NL_SET_ERR_MSG(extack, "rtm_dst_len must be 20 for MPLS");
1805                 goto errout;
1806         }
1807         if (rtm->rtm_src_len != 0) {
1808                 NL_SET_ERR_MSG(extack, "rtm_src_len must be 0 for MPLS");
1809                 goto errout;
1810         }
1811         if (rtm->rtm_tos != 0) {
1812                 NL_SET_ERR_MSG(extack, "rtm_tos must be 0 for MPLS");
1813                 goto errout;
1814         }
1815         if (rtm->rtm_table != RT_TABLE_MAIN) {
1816                 NL_SET_ERR_MSG(extack,
1817                                "MPLS only supports the main route table");
1818                 goto errout;
1819         }
1820         /* Any value is acceptable for rtm_protocol */
1821 
1822         /* As mpls uses destination specific addresses
1823          * (or source specific address in the case of multicast)
1824          * all addresses have universal scope.
1825          */
1826         if (rtm->rtm_scope != RT_SCOPE_UNIVERSE) {
1827                 NL_SET_ERR_MSG(extack,
1828                                "Invalid route scope  - MPLS only supports UNIVERSE");
1829                 goto errout;
1830         }
1831         if (rtm->rtm_type != RTN_UNICAST) {
1832                 NL_SET_ERR_MSG(extack,
1833                                "Invalid route type - MPLS only supports UNICAST");
1834                 goto errout;
1835         }
1836         if (rtm->rtm_flags != 0) {
1837                 NL_SET_ERR_MSG(extack, "rtm_flags must be 0 for MPLS");
1838                 goto errout;
1839         }
1840 
1841         cfg->rc_label           = LABEL_NOT_SPECIFIED;
1842         cfg->rc_protocol        = rtm->rtm_protocol;
1843         cfg->rc_via_table       = MPLS_NEIGH_TABLE_UNSPEC;
1844         cfg->rc_ttl_propagate   = MPLS_TTL_PROP_DEFAULT;
1845         cfg->rc_nlflags         = nlh->nlmsg_flags;
1846         cfg->rc_nlinfo.portid   = NETLINK_CB(skb).portid;
1847         cfg->rc_nlinfo.nlh      = nlh;
1848         cfg->rc_nlinfo.nl_net   = sock_net(skb->sk);
1849 
1850         for (index = 0; index <= RTA_MAX; index++) {
1851                 struct nlattr *nla = tb[index];
1852                 if (!nla)
1853                         continue;
1854 
1855                 switch (index) {
1856                 case RTA_OIF:
1857                         cfg->rc_ifindex = nla_get_u32(nla);
1858                         break;
1859                 case RTA_NEWDST:
1860                         if (nla_get_labels(nla, MAX_NEW_LABELS,
1861                                            &cfg->rc_output_labels,
1862                                            cfg->rc_output_label, extack))
1863                                 goto errout;
1864                         break;
1865                 case RTA_DST:
1866                 {
1867                         u8 label_count;
1868                         if (nla_get_labels(nla, 1, &label_count,
1869                                            &cfg->rc_label, extack))
1870                                 goto errout;
1871 
1872                         if (!mpls_label_ok(cfg->rc_nlinfo.nl_net,
1873                                            &cfg->rc_label, extack))
1874                                 goto errout;
1875                         break;
1876                 }
1877                 case RTA_GATEWAY:
1878                         NL_SET_ERR_MSG(extack, "MPLS does not support RTA_GATEWAY attribute");
1879                         goto errout;
1880                 case RTA_VIA:
1881                 {
1882                         if (nla_get_via(nla, &cfg->rc_via_alen,
1883                                         &cfg->rc_via_table, cfg->rc_via,
1884                                         extack))
1885                                 goto errout;
1886                         break;
1887                 }
1888                 case RTA_MULTIPATH:
1889                 {
1890                         cfg->rc_mp = nla_data(nla);
1891                         cfg->rc_mp_len = nla_len(nla);
1892                         break;
1893                 }
1894                 case RTA_TTL_PROPAGATE:
1895                 {
1896                         u8 ttl_propagate = nla_get_u8(nla);
1897 
1898                         if (ttl_propagate > 1) {
1899                                 NL_SET_ERR_MSG_ATTR(extack, nla,
1900                                                     "RTA_TTL_PROPAGATE can only be 0 or 1");
1901                                 goto errout;
1902                         }
1903                         cfg->rc_ttl_propagate = ttl_propagate ?
1904                                 MPLS_TTL_PROP_ENABLED :
1905                                 MPLS_TTL_PROP_DISABLED;
1906                         break;
1907                 }
1908                 default:
1909                         NL_SET_ERR_MSG_ATTR(extack, nla, "Unknown attribute");
1910                         /* Unsupported attribute */
1911                         goto errout;
1912                 }
1913         }
1914 
1915         err = 0;
1916 errout:
1917         return err;
1918 }
1919 
1920 static int mpls_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
1921                              struct netlink_ext_ack *extack)
1922 {
1923         struct mpls_route_config *cfg;
1924         int err;
1925 
1926         cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
1927         if (!cfg)
1928                 return -ENOMEM;
1929 
1930         err = rtm_to_route_config(skb, nlh, cfg, extack);
1931         if (err < 0)
1932                 goto out;
1933 
1934         err = mpls_route_del(cfg, extack);
1935 out:
1936         kfree(cfg);
1937 
1938         return err;
1939 }
1940 
1941 
1942 static int mpls_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
1943                              struct netlink_ext_ack *extack)
1944 {
1945         struct mpls_route_config *cfg;
1946         int err;
1947 
1948         cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
1949         if (!cfg)
1950                 return -ENOMEM;
1951 
1952         err = rtm_to_route_config(skb, nlh, cfg, extack);
1953         if (err < 0)
1954                 goto out;
1955 
1956         err = mpls_route_add(cfg, extack);
1957 out:
1958         kfree(cfg);
1959 
1960         return err;
1961 }
1962 
1963 static int mpls_dump_route(struct sk_buff *skb, u32 portid, u32 seq, int event,
1964                            u32 label, struct mpls_route *rt, int flags)
1965 {
1966         struct net_device *dev;
1967         struct nlmsghdr *nlh;
1968         struct rtmsg *rtm;
1969 
1970         nlh = nlmsg_put(skb, portid, seq, event, sizeof(*rtm), flags);
1971         if (nlh == NULL)
1972                 return -EMSGSIZE;
1973 
1974         rtm = nlmsg_data(nlh);
1975         rtm->rtm_family = AF_MPLS;
1976         rtm->rtm_dst_len = 20;
1977         rtm->rtm_src_len = 0;
1978         rtm->rtm_tos = 0;
1979         rtm->rtm_table = RT_TABLE_MAIN;
1980         rtm->rtm_protocol = rt->rt_protocol;
1981         rtm->rtm_scope = RT_SCOPE_UNIVERSE;
1982         rtm->rtm_type = RTN_UNICAST;
1983         rtm->rtm_flags = 0;
1984 
1985         if (nla_put_labels(skb, RTA_DST, 1, &label))
1986                 goto nla_put_failure;
1987 
1988         if (rt->rt_ttl_propagate != MPLS_TTL_PROP_DEFAULT) {
1989                 bool ttl_propagate =
1990                         rt->rt_ttl_propagate == MPLS_TTL_PROP_ENABLED;
1991 
1992                 if (nla_put_u8(skb, RTA_TTL_PROPAGATE,
1993                                ttl_propagate))
1994                         goto nla_put_failure;
1995         }
1996         if (rt->rt_nhn == 1) {
1997                 const struct mpls_nh *nh = rt->rt_nh;
1998 
1999                 if (nh->nh_labels &&
2000                     nla_put_labels(skb, RTA_NEWDST, nh->nh_labels,
2001                                    nh->nh_label))
2002                         goto nla_put_failure;
2003                 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC &&
2004                     nla_put_via(skb, nh->nh_via_table, mpls_nh_via(rt, nh),
2005                                 nh->nh_via_alen))
2006                         goto nla_put_failure;
2007                 dev = rtnl_dereference(nh->nh_dev);
2008                 if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex))
2009                         goto nla_put_failure;
2010                 if (nh->nh_flags & RTNH_F_LINKDOWN)
2011                         rtm->rtm_flags |= RTNH_F_LINKDOWN;
2012                 if (nh->nh_flags & RTNH_F_DEAD)
2013                         rtm->rtm_flags |= RTNH_F_DEAD;
2014         } else {
2015                 struct rtnexthop *rtnh;
2016                 struct nlattr *mp;
2017                 u8 linkdown = 0;
2018                 u8 dead = 0;
2019 
2020                 mp = nla_nest_start_noflag(skb, RTA_MULTIPATH);
2021                 if (!mp)
2022                         goto nla_put_failure;
2023 
2024                 for_nexthops(rt) {
2025                         dev = rtnl_dereference(nh->nh_dev);
2026                         if (!dev)
2027                                 continue;
2028 
2029                         rtnh = nla_reserve_nohdr(skb, sizeof(*rtnh));
2030                         if (!rtnh)
2031                                 goto nla_put_failure;
2032 
2033                         rtnh->rtnh_ifindex = dev->ifindex;
2034                         if (nh->nh_flags & RTNH_F_LINKDOWN) {
2035                                 rtnh->rtnh_flags |= RTNH_F_LINKDOWN;
2036                                 linkdown++;
2037                         }
2038                         if (nh->nh_flags & RTNH_F_DEAD) {
2039                                 rtnh->rtnh_flags |= RTNH_F_DEAD;
2040                                 dead++;
2041                         }
2042 
2043                         if (nh->nh_labels && nla_put_labels(skb, RTA_NEWDST,
2044                                                             nh->nh_labels,
2045                                                             nh->nh_label))
2046                                 goto nla_put_failure;
2047                         if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC &&
2048                             nla_put_via(skb, nh->nh_via_table,
2049                                         mpls_nh_via(rt, nh),
2050                                         nh->nh_via_alen))
2051                                 goto nla_put_failure;
2052 
2053                         /* length of rtnetlink header + attributes */
2054                         rtnh->rtnh_len = nlmsg_get_pos(skb) - (void *)rtnh;
2055                 } endfor_nexthops(rt);
2056 
2057                 if (linkdown == rt->rt_nhn)
2058                         rtm->rtm_flags |= RTNH_F_LINKDOWN;
2059                 if (dead == rt->rt_nhn)
2060                         rtm->rtm_flags |= RTNH_F_DEAD;
2061 
2062                 nla_nest_end(skb, mp);
2063         }
2064 
2065         nlmsg_end(skb, nlh);
2066         return 0;
2067 
2068 nla_put_failure:
2069         nlmsg_cancel(skb, nlh);
2070         return -EMSGSIZE;
2071 }
2072 
2073 #if IS_ENABLED(CONFIG_INET)
2074 static int mpls_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
2075                                    struct fib_dump_filter *filter,
2076                                    struct netlink_callback *cb)
2077 {
2078         return ip_valid_fib_dump_req(net, nlh, filter, cb);
2079 }
2080 #else
2081 static int mpls_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
2082                                    struct fib_dump_filter *filter,
2083                                    struct netlink_callback *cb)
2084 {
2085         struct netlink_ext_ack *extack = cb->extack;
2086         struct nlattr *tb[RTA_MAX + 1];
2087         struct rtmsg *rtm;
2088         int err, i;
2089 
2090         if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
2091                 NL_SET_ERR_MSG_MOD(extack, "Invalid header for FIB dump request");
2092                 return -EINVAL;
2093         }
2094 
2095         rtm = nlmsg_data(nlh);
2096         if (rtm->rtm_dst_len || rtm->rtm_src_len  || rtm->rtm_tos   ||
2097             rtm->rtm_table   || rtm->rtm_scope    || rtm->rtm_type  ||
2098             rtm->rtm_flags) {
2099                 NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for FIB dump request");
2100                 return -EINVAL;
2101         }
2102 
2103         if (rtm->rtm_protocol) {
2104                 filter->protocol = rtm->rtm_protocol;
2105                 filter->filter_set = 1;
2106                 cb->answer_flags = NLM_F_DUMP_FILTERED;
2107         }
2108 
2109         err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
2110                                             rtm_mpls_policy, extack);
2111         if (err < 0)
2112                 return err;
2113 
2114         for (i = 0; i <= RTA_MAX; ++i) {
2115                 int ifindex;
2116 
2117                 if (i == RTA_OIF) {
2118                         ifindex = nla_get_u32(tb[i]);
2119                         filter->dev = __dev_get_by_index(net, ifindex);
2120                         if (!filter->dev)
2121                                 return -ENODEV;
2122                         filter->filter_set = 1;
2123                 } else if (tb[i]) {
2124                         NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in dump request");
2125                         return -EINVAL;
2126                 }
2127         }
2128 
2129         return 0;
2130 }
2131 #endif
2132 
2133 static bool mpls_rt_uses_dev(struct mpls_route *rt,
2134                              const struct net_device *dev)
2135 {
2136         struct net_device *nh_dev;
2137 
2138         if (rt->rt_nhn == 1) {
2139                 struct mpls_nh *nh = rt->rt_nh;
2140 
2141                 nh_dev = rtnl_dereference(nh->nh_dev);
2142                 if (dev == nh_dev)
2143                         return true;
2144         } else {
2145                 for_nexthops(rt) {
2146                         nh_dev = rtnl_dereference(nh->nh_dev);
2147                         if (nh_dev == dev)
2148                                 return true;
2149                 } endfor_nexthops(rt);
2150         }
2151 
2152         return false;
2153 }
2154 
2155 static int mpls_dump_routes(struct sk_buff *skb, struct netlink_callback *cb)
2156 {
2157         const struct nlmsghdr *nlh = cb->nlh;
2158         struct net *net = sock_net(skb->sk);
2159         struct mpls_route __rcu **platform_label;
2160         struct fib_dump_filter filter = {};
2161         unsigned int flags = NLM_F_MULTI;
2162         size_t platform_labels;
2163         unsigned int index;
2164 
2165         ASSERT_RTNL();
2166 
2167         if (cb->strict_check) {
2168                 int err;
2169 
2170                 err = mpls_valid_fib_dump_req(net, nlh, &filter, cb);
2171                 if (err < 0)
2172                         return err;
2173 
2174                 /* for MPLS, there is only 1 table with fixed type and flags.
2175                  * If either are set in the filter then return nothing.
2176                  */
2177                 if ((filter.table_id && filter.table_id != RT_TABLE_MAIN) ||
2178                     (filter.rt_type && filter.rt_type != RTN_UNICAST) ||
2179                      filter.flags)
2180                         return skb->len;
2181         }
2182 
2183         index = cb->args[0];
2184         if (index < MPLS_LABEL_FIRST_UNRESERVED)
2185                 index = MPLS_LABEL_FIRST_UNRESERVED;
2186 
2187         platform_label = rtnl_dereference(net->mpls.platform_label);
2188         platform_labels = net->mpls.platform_labels;
2189 
2190         if (filter.filter_set)
2191                 flags |= NLM_F_DUMP_FILTERED;
2192 
2193         for (; index < platform_labels; index++) {
2194                 struct mpls_route *rt;
2195 
2196                 rt = rtnl_dereference(platform_label[index]);
2197                 if (!rt)
2198                         continue;
2199 
2200                 if ((filter.dev && !mpls_rt_uses_dev(rt, filter.dev)) ||
2201                     (filter.protocol && rt->rt_protocol != filter.protocol))
2202                         continue;
2203 
2204                 if (mpls_dump_route(skb, NETLINK_CB(cb->skb).portid,
2205                                     cb->nlh->nlmsg_seq, RTM_NEWROUTE,
2206                                     index, rt, flags) < 0)
2207                         break;
2208         }
2209         cb->args[0] = index;
2210 
2211         return skb->len;
2212 }
2213 
2214 static inline size_t lfib_nlmsg_size(struct mpls_route *rt)
2215 {
2216         size_t payload =
2217                 NLMSG_ALIGN(sizeof(struct rtmsg))
2218                 + nla_total_size(4)                     /* RTA_DST */
2219                 + nla_total_size(1);                    /* RTA_TTL_PROPAGATE */
2220 
2221         if (rt->rt_nhn == 1) {
2222                 struct mpls_nh *nh = rt->rt_nh;
2223 
2224                 if (nh->nh_dev)
2225                         payload += nla_total_size(4); /* RTA_OIF */
2226                 if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC) /* RTA_VIA */
2227                         payload += nla_total_size(2 + nh->nh_via_alen);
2228                 if (nh->nh_labels) /* RTA_NEWDST */
2229                         payload += nla_total_size(nh->nh_labels * 4);
2230         } else {
2231                 /* each nexthop is packed in an attribute */
2232                 size_t nhsize = 0;
2233 
2234                 for_nexthops(rt) {
2235                         if (!rtnl_dereference(nh->nh_dev))
2236                                 continue;
2237                         nhsize += nla_total_size(sizeof(struct rtnexthop));
2238                         /* RTA_VIA */
2239                         if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC)
2240                                 nhsize += nla_total_size(2 + nh->nh_via_alen);
2241                         if (nh->nh_labels)
2242                                 nhsize += nla_total_size(nh->nh_labels * 4);
2243                 } endfor_nexthops(rt);
2244                 /* nested attribute */
2245                 payload += nla_total_size(nhsize);
2246         }
2247 
2248         return payload;
2249 }
2250 
2251 static void rtmsg_lfib(int event, u32 label, struct mpls_route *rt,
2252                        struct nlmsghdr *nlh, struct net *net, u32 portid,
2253                        unsigned int nlm_flags)
2254 {
2255         struct sk_buff *skb;
2256         u32 seq = nlh ? nlh->nlmsg_seq : 0;
2257         int err = -ENOBUFS;
2258 
2259         skb = nlmsg_new(lfib_nlmsg_size(rt), GFP_KERNEL);
2260         if (skb == NULL)
2261                 goto errout;
2262 
2263         err = mpls_dump_route(skb, portid, seq, event, label, rt, nlm_flags);
2264         if (err < 0) {
2265                 /* -EMSGSIZE implies BUG in lfib_nlmsg_size */
2266                 WARN_ON(err == -EMSGSIZE);
2267                 kfree_skb(skb);
2268                 goto errout;
2269         }
2270         rtnl_notify(skb, net, portid, RTNLGRP_MPLS_ROUTE, nlh, GFP_KERNEL);
2271 
2272         return;
2273 errout:
2274         if (err < 0)
2275                 rtnl_set_sk_err(net, RTNLGRP_MPLS_ROUTE, err);
2276 }
2277 
2278 static int mpls_valid_getroute_req(struct sk_buff *skb,
2279                                    const struct nlmsghdr *nlh,
2280                                    struct nlattr **tb,
2281                                    struct netlink_ext_ack *extack)
2282 {
2283         struct rtmsg *rtm;
2284         int i, err;
2285 
2286         if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
2287                 NL_SET_ERR_MSG_MOD(extack,
2288                                    "Invalid header for get route request");
2289                 return -EINVAL;
2290         }
2291 
2292         if (!netlink_strict_get_check(skb))
2293                 return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
2294                                               rtm_mpls_policy, extack);
2295 
2296         rtm = nlmsg_data(nlh);
2297         if ((rtm->rtm_dst_len && rtm->rtm_dst_len != 20) ||
2298             rtm->rtm_src_len || rtm->rtm_tos || rtm->rtm_table ||
2299             rtm->rtm_protocol || rtm->rtm_scope || rtm->rtm_type) {
2300                 NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for get route request");
2301                 return -EINVAL;
2302         }
2303         if (rtm->rtm_flags & ~RTM_F_FIB_MATCH) {
2304                 NL_SET_ERR_MSG_MOD(extack,
2305                                    "Invalid flags for get route request");
2306                 return -EINVAL;
2307         }
2308 
2309         err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
2310                                             rtm_mpls_policy, extack);
2311         if (err)
2312                 return err;
2313 
2314         if ((tb[RTA_DST] || tb[RTA_NEWDST]) && !rtm->rtm_dst_len) {
2315                 NL_SET_ERR_MSG_MOD(extack, "rtm_dst_len must be 20 for MPLS");
2316                 return -EINVAL;
2317         }
2318 
2319         for (i = 0; i <= RTA_MAX; i++) {
2320                 if (!tb[i])
2321                         continue;
2322 
2323                 switch (i) {
2324                 case RTA_DST:
2325                 case RTA_NEWDST:
2326                         break;
2327                 default:
2328                         NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in get route request");
2329                         return -EINVAL;
2330                 }
2331         }
2332 
2333         return 0;
2334 }
2335 
2336 static int mpls_getroute(struct sk_buff *in_skb, struct nlmsghdr *in_nlh,
2337                          struct netlink_ext_ack *extack)
2338 {
2339         struct net *net = sock_net(in_skb->sk);
2340         u32 portid = NETLINK_CB(in_skb).portid;
2341         u32 in_label = LABEL_NOT_SPECIFIED;
2342         struct nlattr *tb[RTA_MAX + 1];
2343         u32 labels[MAX_NEW_LABELS];
2344         struct mpls_shim_hdr *hdr;
2345         unsigned int hdr_size = 0;
2346         struct net_device *dev;
2347         struct mpls_route *rt;
2348         struct rtmsg *rtm, *r;
2349         struct nlmsghdr *nlh;
2350         struct sk_buff *skb;
2351         struct mpls_nh *nh;
2352         u8 n_labels;
2353         int err;
2354 
2355         err = mpls_valid_getroute_req(in_skb, in_nlh, tb, extack);
2356         if (err < 0)
2357                 goto errout;
2358 
2359         rtm = nlmsg_data(in_nlh);
2360 
2361         if (tb[RTA_DST]) {
2362                 u8 label_count;
2363 
2364                 if (nla_get_labels(tb[RTA_DST], 1, &label_count,
2365                                    &in_label, extack)) {
2366                         err = -EINVAL;
2367                         goto errout;
2368                 }
2369 
2370                 if (!mpls_label_ok(net, &in_label, extack)) {
2371                         err = -EINVAL;
2372                         goto errout;
2373                 }
2374         }
2375 
2376         rt = mpls_route_input_rcu(net, in_label);
2377         if (!rt) {
2378                 err = -ENETUNREACH;
2379                 goto errout;
2380         }
2381 
2382         if (rtm->rtm_flags & RTM_F_FIB_MATCH) {
2383                 skb = nlmsg_new(lfib_nlmsg_size(rt), GFP_KERNEL);
2384                 if (!skb) {
2385                         err = -ENOBUFS;
2386                         goto errout;
2387                 }
2388 
2389                 err = mpls_dump_route(skb, portid, in_nlh->nlmsg_seq,
2390                                       RTM_NEWROUTE, in_label, rt, 0);
2391                 if (err < 0) {
2392                         /* -EMSGSIZE implies BUG in lfib_nlmsg_size */
2393                         WARN_ON(err == -EMSGSIZE);
2394                         goto errout_free;
2395                 }
2396 
2397                 return rtnl_unicast(skb, net, portid);
2398         }
2399 
2400         if (tb[RTA_NEWDST]) {
2401                 if (nla_get_labels(tb[RTA_NEWDST], MAX_NEW_LABELS, &n_labels,
2402                                    labels, extack) != 0) {
2403                         err = -EINVAL;
2404                         goto errout;
2405                 }
2406 
2407                 hdr_size = n_labels * sizeof(struct mpls_shim_hdr);
2408         }
2409 
2410         skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2411         if (!skb) {
2412                 err = -ENOBUFS;
2413                 goto errout;
2414         }
2415 
2416         skb->protocol = htons(ETH_P_MPLS_UC);
2417 
2418         if (hdr_size) {
2419                 bool bos;
2420                 int i;
2421 
2422                 if (skb_cow(skb, hdr_size)) {
2423                         err = -ENOBUFS;
2424                         goto errout_free;
2425                 }
2426 
2427                 skb_reserve(skb, hdr_size);
2428                 skb_push(skb, hdr_size);
2429                 skb_reset_network_header(skb);
2430 
2431                 /* Push new labels */
2432                 hdr = mpls_hdr(skb);
2433                 bos = true;
2434                 for (i = n_labels - 1; i >= 0; i--) {
2435                         hdr[i] = mpls_entry_encode(labels[i],
2436                                                    1, 0, bos);
2437                         bos = false;
2438                 }
2439         }
2440 
2441         nh = mpls_select_multipath(rt, skb);
2442         if (!nh) {
2443                 err = -ENETUNREACH;
2444                 goto errout_free;
2445         }
2446 
2447         if (hdr_size) {
2448                 skb_pull(skb, hdr_size);
2449                 skb_reset_network_header(skb);
2450         }
2451 
2452         nlh = nlmsg_put(skb, portid, in_nlh->nlmsg_seq,
2453                         RTM_NEWROUTE, sizeof(*r), 0);
2454         if (!nlh) {
2455                 err = -EMSGSIZE;
2456                 goto errout_free;
2457         }
2458 
2459         r = nlmsg_data(nlh);
2460         r->rtm_family    = AF_MPLS;
2461         r->rtm_dst_len  = 20;
2462         r->rtm_src_len  = 0;
2463         r->rtm_table    = RT_TABLE_MAIN;
2464         r->rtm_type     = RTN_UNICAST;
2465         r->rtm_scope    = RT_SCOPE_UNIVERSE;
2466         r->rtm_protocol = rt->rt_protocol;
2467         r->rtm_flags    = 0;
2468 
2469         if (nla_put_labels(skb, RTA_DST, 1, &in_label))
2470                 goto nla_put_failure;
2471 
2472         if (nh->nh_labels &&
2473             nla_put_labels(skb, RTA_NEWDST, nh->nh_labels,
2474                            nh->nh_label))
2475                 goto nla_put_failure;
2476 
2477         if (nh->nh_via_table != MPLS_NEIGH_TABLE_UNSPEC &&
2478             nla_put_via(skb, nh->nh_via_table, mpls_nh_via(rt, nh),
2479                         nh->nh_via_alen))
2480                 goto nla_put_failure;
2481         dev = rtnl_dereference(nh->nh_dev);
2482         if (dev && nla_put_u32(skb, RTA_OIF, dev->ifindex))
2483                 goto nla_put_failure;
2484 
2485         nlmsg_end(skb, nlh);
2486 
2487         err = rtnl_unicast(skb, net, portid);
2488 errout:
2489         return err;
2490 
2491 nla_put_failure:
2492         nlmsg_cancel(skb, nlh);
2493         err = -EMSGSIZE;
2494 errout_free:
2495         kfree_skb(skb);
2496         return err;
2497 }
2498 
2499 static int resize_platform_label_table(struct net *net, size_t limit)
2500 {
2501         size_t size = sizeof(struct mpls_route *) * limit;
2502         size_t old_limit;
2503         size_t cp_size;
2504         struct mpls_route __rcu **labels = NULL, **old;
2505         struct mpls_route *rt0 = NULL, *rt2 = NULL;
2506         unsigned index;
2507 
2508         if (size) {
2509                 labels = kvzalloc(size, GFP_KERNEL);
2510                 if (!labels)
2511                         goto nolabels;
2512         }
2513 
2514         /* In case the predefined labels need to be populated */
2515         if (limit > MPLS_LABEL_IPV4NULL) {
2516                 struct net_device *lo = net->loopback_dev;
2517                 rt0 = mpls_rt_alloc(1, lo->addr_len, 0);
2518                 if (IS_ERR(rt0))
2519                         goto nort0;
2520                 RCU_INIT_POINTER(rt0->rt_nh->nh_dev, lo);
2521                 rt0->rt_protocol = RTPROT_KERNEL;
2522                 rt0->rt_payload_type = MPT_IPV4;
2523                 rt0->rt_ttl_propagate = MPLS_TTL_PROP_DEFAULT;
2524                 rt0->rt_nh->nh_via_table = NEIGH_LINK_TABLE;
2525                 rt0->rt_nh->nh_via_alen = lo->addr_len;
2526                 memcpy(__mpls_nh_via(rt0, rt0->rt_nh), lo->dev_addr,
2527                        lo->addr_len);
2528         }
2529         if (limit > MPLS_LABEL_IPV6NULL) {
2530                 struct net_device *lo = net->loopback_dev;
2531                 rt2 = mpls_rt_alloc(1, lo->addr_len, 0);
2532                 if (IS_ERR(rt2))
2533                         goto nort2;
2534                 RCU_INIT_POINTER(rt2->rt_nh->nh_dev, lo);
2535                 rt2->rt_protocol = RTPROT_KERNEL;
2536                 rt2->rt_payload_type = MPT_IPV6;
2537                 rt2->rt_ttl_propagate = MPLS_TTL_PROP_DEFAULT;
2538                 rt2->rt_nh->nh_via_table = NEIGH_LINK_TABLE;
2539                 rt2->rt_nh->nh_via_alen = lo->addr_len;
2540                 memcpy(__mpls_nh_via(rt2, rt2->rt_nh), lo->dev_addr,
2541                        lo->addr_len);
2542         }
2543 
2544         rtnl_lock();
2545         /* Remember the original table */
2546         old = rtnl_dereference(net->mpls.platform_label);
2547         old_limit = net->mpls.platform_labels;
2548 
2549         /* Free any labels beyond the new table */
2550         for (index = limit; index < old_limit; index++)
2551                 mpls_route_update(net, index, NULL, NULL);
2552 
2553         /* Copy over the old labels */
2554         cp_size = size;
2555         if (old_limit < limit)
2556                 cp_size = old_limit * sizeof(struct mpls_route *);
2557 
2558         memcpy(labels, old, cp_size);
2559 
2560         /* If needed set the predefined labels */
2561         if ((old_limit <= MPLS_LABEL_IPV6NULL) &&
2562             (limit > MPLS_LABEL_IPV6NULL)) {
2563                 RCU_INIT_POINTER(labels[MPLS_LABEL_IPV6NULL], rt2);
2564                 rt2 = NULL;
2565         }
2566 
2567         if ((old_limit <= MPLS_LABEL_IPV4NULL) &&
2568             (limit > MPLS_LABEL_IPV4NULL)) {
2569                 RCU_INIT_POINTER(labels[MPLS_LABEL_IPV4NULL], rt0);
2570                 rt0 = NULL;
2571         }
2572 
2573         /* Update the global pointers */
2574         net->mpls.platform_labels = limit;
2575         rcu_assign_pointer(net->mpls.platform_label, labels);
2576 
2577         rtnl_unlock();
2578 
2579         mpls_rt_free(rt2);
2580         mpls_rt_free(rt0);
2581 
2582         if (old) {
2583                 synchronize_rcu();
2584                 kvfree(old);
2585         }
2586         return 0;
2587 
2588 nort2:
2589         mpls_rt_free(rt0);
2590 nort0:
2591         kvfree(labels);
2592 nolabels:
2593         return -ENOMEM;
2594 }
2595 
2596 static int mpls_platform_labels(struct ctl_table *table, int write,
2597                                 void __user *buffer, size_t *lenp, loff_t *ppos)
2598 {
2599         struct net *net = table->data;
2600         int platform_labels = net->mpls.platform_labels;
2601         int ret;
2602         struct ctl_table tmp = {
2603                 .procname       = table->procname,
2604                 .data           = &platform_labels,
2605                 .maxlen         = sizeof(int),
2606                 .mode           = table->mode,
2607                 .extra1         = SYSCTL_ZERO,
2608                 .extra2         = &label_limit,
2609         };
2610 
2611         ret = proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
2612 
2613         if (write && ret == 0)
2614                 ret = resize_platform_label_table(net, platform_labels);
2615 
2616         return ret;
2617 }
2618 
2619 #define MPLS_NS_SYSCTL_OFFSET(field)            \
2620         (&((struct net *)0)->field)
2621 
2622 static const struct ctl_table mpls_table[] = {
2623         {
2624                 .procname       = "platform_labels",
2625                 .data           = NULL,
2626                 .maxlen         = sizeof(int),
2627                 .mode           = 0644,
2628                 .proc_handler   = mpls_platform_labels,
2629         },
2630         {
2631                 .procname       = "ip_ttl_propagate",
2632                 .data           = MPLS_NS_SYSCTL_OFFSET(mpls.ip_ttl_propagate),
2633                 .maxlen         = sizeof(int),
2634                 .mode           = 0644,
2635                 .proc_handler   = proc_dointvec_minmax,
2636                 .extra1         = SYSCTL_ZERO,
2637                 .extra2         = SYSCTL_ONE,
2638         },
2639         {
2640                 .procname       = "default_ttl",
2641                 .data           = MPLS_NS_SYSCTL_OFFSET(mpls.default_ttl),
2642                 .maxlen         = sizeof(int),
2643                 .mode           = 0644,
2644                 .proc_handler   = proc_dointvec_minmax,
2645                 .extra1         = SYSCTL_ONE,
2646                 .extra2         = &ttl_max,
2647         },
2648         { }
2649 };
2650 
2651 static int mpls_net_init(struct net *net)
2652 {
2653         struct ctl_table *table;
2654         int i;
2655 
2656         net->mpls.platform_labels = 0;
2657         net->mpls.platform_label = NULL;
2658         net->mpls.ip_ttl_propagate = 1;
2659         net->mpls.default_ttl = 255;
2660 
2661         table = kmemdup(mpls_table, sizeof(mpls_table), GFP_KERNEL);
2662         if (table == NULL)
2663                 return -ENOMEM;
2664 
2665         /* Table data contains only offsets relative to the base of
2666          * the mdev at this point, so make them absolute.
2667          */
2668         for (i = 0; i < ARRAY_SIZE(mpls_table) - 1; i++)
2669                 table[i].data = (char *)net + (uintptr_t)table[i].data;
2670 
2671         net->mpls.ctl = register_net_sysctl(net, "net/mpls", table);
2672         if (net->mpls.ctl == NULL) {
2673                 kfree(table);
2674                 return -ENOMEM;
2675         }
2676 
2677         return 0;
2678 }
2679 
2680 static void mpls_net_exit(struct net *net)
2681 {
2682         struct mpls_route __rcu **platform_label;
2683         size_t platform_labels;
2684         struct ctl_table *table;
2685         unsigned int index;
2686 
2687         table = net->mpls.ctl->ctl_table_arg;
2688         unregister_net_sysctl_table(net->mpls.ctl);
2689         kfree(table);
2690 
2691         /* An rcu grace period has passed since there was a device in
2692          * the network namespace (and thus the last in flight packet)
2693          * left this network namespace.  This is because
2694          * unregister_netdevice_many and netdev_run_todo has completed
2695          * for each network device that was in this network namespace.
2696          *
2697          * As such no additional rcu synchronization is necessary when
2698          * freeing the platform_label table.
2699          */
2700         rtnl_lock();
2701         platform_label = rtnl_dereference(net->mpls.platform_label);
2702         platform_labels = net->mpls.platform_labels;
2703         for (index = 0; index < platform_labels; index++) {
2704                 struct mpls_route *rt = rtnl_dereference(platform_label[index]);
2705                 RCU_INIT_POINTER(platform_label[index], NULL);
2706                 mpls_notify_route(net, index, rt, NULL, NULL);
2707                 mpls_rt_free(rt);
2708         }
2709         rtnl_unlock();
2710 
2711         kvfree(platform_label);
2712 }
2713 
2714 static struct pernet_operations mpls_net_ops = {
2715         .init = mpls_net_init,
2716         .exit = mpls_net_exit,
2717 };
2718 
2719 static struct rtnl_af_ops mpls_af_ops __read_mostly = {
2720         .family            = AF_MPLS,
2721         .fill_stats_af     = mpls_fill_stats_af,
2722         .get_stats_af_size = mpls_get_stats_af_size,
2723 };
2724 
2725 static int __init mpls_init(void)
2726 {
2727         int err;
2728 
2729         BUILD_BUG_ON(sizeof(struct mpls_shim_hdr) != 4);
2730 
2731         err = register_pernet_subsys(&mpls_net_ops);
2732         if (err)
2733                 goto out;
2734 
2735         err = register_netdevice_notifier(&mpls_dev_notifier);
2736         if (err)
2737                 goto out_unregister_pernet;
2738 
2739         dev_add_pack(&mpls_packet_type);
2740 
2741         rtnl_af_register(&mpls_af_ops);
2742 
2743         rtnl_register_module(THIS_MODULE, PF_MPLS, RTM_NEWROUTE,
2744                              mpls_rtm_newroute, NULL, 0);
2745         rtnl_register_module(THIS_MODULE, PF_MPLS, RTM_DELROUTE,
2746                              mpls_rtm_delroute, NULL, 0);
2747         rtnl_register_module(THIS_MODULE, PF_MPLS, RTM_GETROUTE,
2748                              mpls_getroute, mpls_dump_routes, 0);
2749         rtnl_register_module(THIS_MODULE, PF_MPLS, RTM_GETNETCONF,
2750                              mpls_netconf_get_devconf,
2751                              mpls_netconf_dump_devconf, 0);
2752         err = ipgre_tunnel_encap_add_mpls_ops();
2753         if (err)
2754                 pr_err("Can't add mpls over gre tunnel ops\n");
2755 
2756         err = 0;
2757 out:
2758         return err;
2759 
2760 out_unregister_pernet:
2761         unregister_pernet_subsys(&mpls_net_ops);
2762         goto out;
2763 }
2764 module_init(mpls_init);
2765 
2766 static void __exit mpls_exit(void)
2767 {
2768         rtnl_unregister_all(PF_MPLS);
2769         rtnl_af_unregister(&mpls_af_ops);
2770         dev_remove_pack(&mpls_packet_type);
2771         unregister_netdevice_notifier(&mpls_dev_notifier);
2772         unregister_pernet_subsys(&mpls_net_ops);
2773         ipgre_tunnel_encap_del_mpls_ops();
2774 }
2775 module_exit(mpls_exit);
2776 
2777 MODULE_DESCRIPTION("MultiProtocol Label Switching");
2778 MODULE_LICENSE("GPL v2");
2779 MODULE_ALIAS_NETPROTO(PF_MPLS);
2780 

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