net/ipv4/ipmr_base.c

   1 /* Linux multicast routing support
   2  * Common logic shared by IPv4 [ipmr] and IPv6 [ip6mr] implementation
   3  */
   4
   5 #include <linux/rhashtable.h>
   6 #include <linux/mroute_base.h>
   7
   8 /* Sets everything common except 'dev', since that is done under locking */
   9 void vif_device_init(struct vif_device *v,
  10                      struct net_device *dev,
  11                      unsigned long rate_limit,
  12                      unsigned char threshold,
  13                      unsigned short flags,
  14                      unsigned short get_iflink_mask)
  15 {
  16         v->dev = NULL;
  17         v->bytes_in = 0;
  18         v->bytes_out = 0;
  19         v->pkt_in = 0;
  20         v->pkt_out = 0;
  21         v->rate_limit = rate_limit;
  22         v->flags = flags;
  23         v->threshold = threshold;
  24         if (v->flags & get_iflink_mask)
  25                 v->link = dev_get_iflink(dev);
  26         else
  27                 v->link = dev->ifindex;
  28 }
  29 EXPORT_SYMBOL(vif_device_init);
  30
  31 struct mr_table *
  32 mr_table_alloc(struct net *net, u32 id,
  33                struct mr_table_ops *ops,
  34                void (*expire_func)(struct timer_list *t),
  35                void (*table_set)(struct mr_table *mrt,
  36                                  struct net *net))
  37 {
  38         struct mr_table *mrt;
  39         int err;
  40
  41         mrt = kzalloc(sizeof(*mrt), GFP_KERNEL);
  42         if (!mrt)
  43                 return ERR_PTR(-ENOMEM);
  44         mrt->id = id;
  45         write_pnet(&mrt->net, net);
  46
  47         mrt->ops = *ops;
  48         err = rhltable_init(&mrt->mfc_hash, mrt->ops.rht_params);
  49         if (err) {
  50                 kfree(mrt);
  51                 return ERR_PTR(err);
  52         }
  53         INIT_LIST_HEAD(&mrt->mfc_cache_list);
  54         INIT_LIST_HEAD(&mrt->mfc_unres_queue);
  55
  56         timer_setup(&mrt->ipmr_expire_timer, expire_func, 0);
  57
  58         mrt->mroute_reg_vif_num = -1;
  59         table_set(mrt, net);
  60         return mrt;
  61 }
  62 EXPORT_SYMBOL(mr_table_alloc);
  63
  64 void *mr_mfc_find_parent(struct mr_table *mrt, void *hasharg, int parent)
  65 {
  66         struct rhlist_head *tmp, *list;
  67         struct mr_mfc *c;
  68
  69         list = rhltable_lookup(&mrt->mfc_hash, hasharg, *mrt->ops.rht_params);
  70         rhl_for_each_entry_rcu(c, tmp, list, mnode)
  71                 if (parent == -1 || parent == c->mfc_parent)
  72                         return c;
  73
  74         return NULL;
  75 }
  76 EXPORT_SYMBOL(mr_mfc_find_parent);
  77
  78 void *mr_mfc_find_any_parent(struct mr_table *mrt, int vifi)
  79 {
  80         struct rhlist_head *tmp, *list;
  81         struct mr_mfc *c;
  82
  83         list = rhltable_lookup(&mrt->mfc_hash, mrt->ops.cmparg_any,
  84                                *mrt->ops.rht_params);
  85         rhl_for_each_entry_rcu(c, tmp, list, mnode)
  86                 if (c->mfc_un.res.ttls[vifi] < 255)
  87                         return c;
  88
  89         return NULL;
  90 }
  91 EXPORT_SYMBOL(mr_mfc_find_any_parent);
  92
  93 void *mr_mfc_find_any(struct mr_table *mrt, int vifi, void *hasharg)
  94 {
  95         struct rhlist_head *tmp, *list;
  96         struct mr_mfc *c, *proxy;
  97
  98         list = rhltable_lookup(&mrt->mfc_hash, hasharg, *mrt->ops.rht_params);
  99         rhl_for_each_entry_rcu(c, tmp, list, mnode) {
 100                 if (c->mfc_un.res.ttls[vifi] < 255)
 101                         return c;
 102
 103                 /* It's ok if the vifi is part of the static tree */
 104                 proxy = mr_mfc_find_any_parent(mrt, c->mfc_parent);
 105                 if (proxy && proxy->mfc_un.res.ttls[vifi] < 255)
 106                         return c;
 107         }
 108
 109         return mr_mfc_find_any_parent(mrt, vifi);
 110 }
 111 EXPORT_SYMBOL(mr_mfc_find_any);
 112
 113 #ifdef CONFIG_PROC_FS
 114 void *mr_vif_seq_idx(struct net *net, struct mr_vif_iter *iter, loff_t pos)
 115 {
 116         struct mr_table *mrt = iter->mrt;
 117
 118         for (iter->ct = 0; iter->ct < mrt->maxvif; ++iter->ct) {
 119                 if (!VIF_EXISTS(mrt, iter->ct))
 120                         continue;
 121                 if (pos-- == 0)
 122                         return &mrt->vif_table[iter->ct];
 123         }
 124         return NULL;
 125 }
 126 EXPORT_SYMBOL(mr_vif_seq_idx);
 127
 128 void *mr_vif_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 129 {
 130         struct mr_vif_iter *iter = seq->private;
 131         struct net *net = seq_file_net(seq);
 132         struct mr_table *mrt = iter->mrt;
 133
 134         ++*pos;
 135         if (v == SEQ_START_TOKEN)
 136                 return mr_vif_seq_idx(net, iter, 0);
 137
 138         while (++iter->ct < mrt->maxvif) {
 139                 if (!VIF_EXISTS(mrt, iter->ct))
 140                         continue;
 141                 return &mrt->vif_table[iter->ct];
 142         }
 143         return NULL;
 144 }
 145 EXPORT_SYMBOL(mr_vif_seq_next);
 146
 147 void *mr_mfc_seq_idx(struct net *net,
 148                      struct mr_mfc_iter *it, loff_t pos)
 149 {
 150         struct mr_table *mrt = it->mrt;
 151         struct mr_mfc *mfc;
 152
 153         rcu_read_lock();
 154         it->cache = &mrt->mfc_cache_list;
 155         list_for_each_entry_rcu(mfc, &mrt->mfc_cache_list, list)
 156                 if (pos-- == 0)
 157                         return mfc;
 158         rcu_read_unlock();
 159
 160         spin_lock_bh(it->lock);
 161         it->cache = &mrt->mfc_unres_queue;
 162         list_for_each_entry(mfc, it->cache, list)
 163                 if (pos-- == 0)
 164                         return mfc;
 165         spin_unlock_bh(it->lock);
 166
 167         it->cache = NULL;
 168         return NULL;
 169 }
 170 EXPORT_SYMBOL(mr_mfc_seq_idx);
 171
 172 void *mr_mfc_seq_next(struct seq_file *seq, void *v,
 173                       loff_t *pos)
 174 {
 175         struct mr_mfc_iter *it = seq->private;
 176         struct net *net = seq_file_net(seq);
 177         struct mr_table *mrt = it->mrt;
 178         struct mr_mfc *c = v;
 179
 180         ++*pos;
 181
 182         if (v == SEQ_START_TOKEN)
 183                 return mr_mfc_seq_idx(net, seq->private, 0);
 184
 185         if (c->list.next != it->cache)
 186                 return list_entry(c->list.next, struct mr_mfc, list);
 187
 188         if (it->cache == &mrt->mfc_unres_queue)
 189                 goto end_of_list;
 190
 191         /* exhausted cache_array, show unresolved */
 192         rcu_read_unlock();
 193         it->cache = &mrt->mfc_unres_queue;
 194
 195         spin_lock_bh(it->lock);
 196         if (!list_empty(it->cache))
 197                 return list_first_entry(it->cache, struct mr_mfc, list);
 198
 199 end_of_list:
 200         spin_unlock_bh(it->lock);
 201         it->cache = NULL;
 202
 203         return NULL;
 204 }
 205 EXPORT_SYMBOL(mr_mfc_seq_next);
 206 #endif
 207
 208 int mr_fill_mroute(struct mr_table *mrt, struct sk_buff *skb,
 209                    struct mr_mfc *c, struct rtmsg *rtm)
 210 {
 211         struct rta_mfc_stats mfcs;
 212         struct nlattr *mp_attr;
 213         struct rtnexthop *nhp;
 214         unsigned long lastuse;
 215         int ct;
 216
 217         /* If cache is unresolved, don't try to parse IIF and OIF */
 218         if (c->mfc_parent >= MAXVIFS) {
 219                 rtm->rtm_flags |= RTNH_F_UNRESOLVED;
 220                 return -ENOENT;
 221         }
 222
 223         if (VIF_EXISTS(mrt, c->mfc_parent) &&
 224             nla_put_u32(skb, RTA_IIF,
 225                         mrt->vif_table[c->mfc_parent].dev->ifindex) < 0)
 226                 return -EMSGSIZE;
 227
 228         if (c->mfc_flags & MFC_OFFLOAD)
 229                 rtm->rtm_flags |= RTNH_F_OFFLOAD;
 230
 231         mp_attr = nla_nest_start_noflag(skb, RTA_MULTIPATH);
 232         if (!mp_attr)
 233                 return -EMSGSIZE;
 234
 235         for (ct = c->mfc_un.res.minvif; ct < c->mfc_un.res.maxvif; ct++) {
 236                 if (VIF_EXISTS(mrt, ct) && c->mfc_un.res.ttls[ct] < 255) {
 237                         struct vif_device *vif;
 238
 239                         nhp = nla_reserve_nohdr(skb, sizeof(*nhp));
 240                         if (!nhp) {
 241                                 nla_nest_cancel(skb, mp_attr);
 242                                 return -EMSGSIZE;
 243                         }
 244
 245                         nhp->rtnh_flags = 0;
 246                         nhp->rtnh_hops = c->mfc_un.res.ttls[ct];
 247                         vif = &mrt->vif_table[ct];
 248                         nhp->rtnh_ifindex = vif->dev->ifindex;
 249                         nhp->rtnh_len = sizeof(*nhp);
 250                 }
 251         }
 252
 253         nla_nest_end(skb, mp_attr);
 254
 255         lastuse = READ_ONCE(c->mfc_un.res.lastuse);
 256         lastuse = time_after_eq(jiffies, lastuse) ? jiffies - lastuse : 0;
 257
 258         mfcs.mfcs_packets = c->mfc_un.res.pkt;
 259         mfcs.mfcs_bytes = c->mfc_un.res.bytes;
 260         mfcs.mfcs_wrong_if = c->mfc_un.res.wrong_if;
 261         if (nla_put_64bit(skb, RTA_MFC_STATS, sizeof(mfcs), &mfcs, RTA_PAD) ||
 262             nla_put_u64_64bit(skb, RTA_EXPIRES, jiffies_to_clock_t(lastuse),
 263                               RTA_PAD))
 264                 return -EMSGSIZE;
 265
 266         rtm->rtm_type = RTN_MULTICAST;
 267         return 1;
 268 }
 269 EXPORT_SYMBOL(mr_fill_mroute);
 270
 271 static bool mr_mfc_uses_dev(const struct mr_table *mrt,
 272                             const struct mr_mfc *c,
 273                             const struct net_device *dev)
 274 {
 275         int ct;
 276
 277         for (ct = c->mfc_un.res.minvif; ct < c->mfc_un.res.maxvif; ct++) {
 278                 if (VIF_EXISTS(mrt, ct) && c->mfc_un.res.ttls[ct] < 255) {
 279                         const struct vif_device *vif;
 280
 281                         vif = &mrt->vif_table[ct];
 282                         if (vif->dev == dev)
 283                                 return true;
 284                 }
 285         }
 286         return false;
 287 }
 288
 289 int mr_table_dump(struct mr_table *mrt, struct sk_buff *skb,
 290                   struct netlink_callback *cb,
 291                   int (*fill)(struct mr_table *mrt, struct sk_buff *skb,
 292                               u32 portid, u32 seq, struct mr_mfc *c,
 293                               int cmd, int flags),
 294                   spinlock_t *lock, struct fib_dump_filter *filter)
 295 {
 296         unsigned int e = 0, s_e = cb->args[1];
 297         unsigned int flags = NLM_F_MULTI;
 298         struct mr_mfc *mfc;
 299         int err;
 300
 301         if (filter->filter_set)
 302                 flags |= NLM_F_DUMP_FILTERED;
 303
 304         list_for_each_entry_rcu(mfc, &mrt->mfc_cache_list, list) {
 305                 if (e < s_e)
 306                         goto next_entry;
 307                 if (filter->dev &&
 308                     !mr_mfc_uses_dev(mrt, mfc, filter->dev))
 309                         goto next_entry;
 310
 311                 err = fill(mrt, skb, NETLINK_CB(cb->skb).portid,
 312                            cb->nlh->nlmsg_seq, mfc, RTM_NEWROUTE, flags);
 313                 if (err < 0)
 314                         goto out;
 315 next_entry:
 316                 e++;
 317         }
 318
 319         spin_lock_bh(lock);
 320         list_for_each_entry(mfc, &mrt->mfc_unres_queue, list) {
 321                 if (e < s_e)
 322                         goto next_entry2;
 323                 if (filter->dev &&
 324                     !mr_mfc_uses_dev(mrt, mfc, filter->dev))
 325                         goto next_entry2;
 326
 327                 err = fill(mrt, skb, NETLINK_CB(cb->skb).portid,
 328                            cb->nlh->nlmsg_seq, mfc, RTM_NEWROUTE, flags);
 329                 if (err < 0) {
 330                         spin_unlock_bh(lock);
 331                         goto out;
 332                 }
 333 next_entry2:
 334                 e++;
 335         }
 336         spin_unlock_bh(lock);
 337         err = 0;
 338 out:
 339         cb->args[1] = e;
 340         return err;
 341 }
 342 EXPORT_SYMBOL(mr_table_dump);
 343
 344 int mr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb,
 345                      struct mr_table *(*iter)(struct net *net,
 346                                               struct mr_table *mrt),
 347                      int (*fill)(struct mr_table *mrt,
 348                                  struct sk_buff *skb,
 349                                  u32 portid, u32 seq, struct mr_mfc *c,
 350                                  int cmd, int flags),
 351                      spinlock_t *lock, struct fib_dump_filter *filter)
 352 {
 353         unsigned int t = 0, s_t = cb->args[0];
 354         struct net *net = sock_net(skb->sk);
 355         struct mr_table *mrt;
 356         int err;
 357
 358         /* multicast does not track protocol or have route type other
 359          * than RTN_MULTICAST
 360          */
 361         if (filter->filter_set) {
 362                 if (filter->protocol || filter->flags ||
 363                     (filter->rt_type && filter->rt_type != RTN_MULTICAST))
 364                         return skb->len;
 365         }
 366
 367         rcu_read_lock();
 368         for (mrt = iter(net, NULL); mrt; mrt = iter(net, mrt)) {
 369                 if (t < s_t)
 370                         goto next_table;
 371
 372                 err = mr_table_dump(mrt, skb, cb, fill, lock, filter);
 373                 if (err < 0)
 374                         break;
 375                 cb->args[1] = 0;
 376 next_table:
 377                 t++;
 378         }
 379         rcu_read_unlock();
 380
 381         cb->args[0] = t;
 382
 383         return skb->len;
 384 }
 385 EXPORT_SYMBOL(mr_rtm_dumproute);
 386
 387 int mr_dump(struct net *net, struct notifier_block *nb, unsigned short family,
 388             int (*rules_dump)(struct net *net,
 389                               struct notifier_block *nb,
 390                               struct netlink_ext_ack *extack),
 391             struct mr_table *(*mr_iter)(struct net *net,
 392                                         struct mr_table *mrt),
 393             rwlock_t *mrt_lock,
 394             struct netlink_ext_ack *extack)
 395 {
 396         struct mr_table *mrt;
 397         int err;
 398
 399         err = rules_dump(net, nb, extack);
 400         if (err)
 401                 return err;
 402
 403         for (mrt = mr_iter(net, NULL); mrt; mrt = mr_iter(net, mrt)) {
 404                 struct vif_device *v = &mrt->vif_table[0];
 405                 struct mr_mfc *mfc;
 406                 int vifi;
 407
 408                 /* Notifiy on table VIF entries */
 409                 read_lock(mrt_lock);
 410                 for (vifi = 0; vifi < mrt->maxvif; vifi++, v++) {
 411                         if (!v->dev)
 412                                 continue;
 413
 414                         err = mr_call_vif_notifier(nb, family,
 415                                                    FIB_EVENT_VIF_ADD,
 416                                                    v, vifi, mrt->id, extack);
 417                         if (err)
 418                                 break;
 419                 }
 420                 read_unlock(mrt_lock);
 421
 422                 if (err)
 423                         return err;
 424
 425                 /* Notify on table MFC entries */
 426                 list_for_each_entry_rcu(mfc, &mrt->mfc_cache_list, list) {
 427                         err = mr_call_mfc_notifier(nb, family,
 428                                                    FIB_EVENT_ENTRY_ADD,
 429                                                    mfc, mrt->id, extack);
 430                         if (err)
 431                                 return err;
 432                 }
 433         }
 434
 435         return 0;
 436 }
 437 EXPORT_SYMBOL(mr_dump);