net/ipv6/ip6_flowlabel.c

   1 /*
   2  *      ip6_flowlabel.c         IPv6 flowlabel manager.
   3  *
   4  *      This program is free software; you can redistribute it and/or
   5  *      modify it under the terms of the GNU General Public License
   6  *      as published by the Free Software Foundation; either version
   7  *      2 of the License, or (at your option) any later version.
   8  *
   9  *      Authors:        Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
  10  */
  11
  12 #include <linux/capability.h>
  13 #include <linux/errno.h>
  14 #include <linux/types.h>
  15 #include <linux/socket.h>
  16 #include <linux/net.h>
  17 #include <linux/netdevice.h>
  18 #include <linux/if_arp.h>
  19 #include <linux/in6.h>
  20 #include <linux/route.h>
  21 #include <linux/proc_fs.h>
  22 #include <linux/seq_file.h>
  23 #include <linux/slab.h>
  24 #include <linux/export.h>
  25 #include <linux/pid_namespace.h>
  26
  27 #include <net/net_namespace.h>
  28 #include <net/sock.h>
  29
  30 #include <net/ipv6.h>
  31 #include <net/ndisc.h>
  32 #include <net/protocol.h>
  33 #include <net/ip6_route.h>
  34 #include <net/addrconf.h>
  35 #include <net/rawv6.h>
  36 #include <net/icmp.h>
  37 #include <net/transp_v6.h>
  38
  39 #include <asm/uaccess.h>
  40
  41 #define FL_MIN_LINGER   6       /* Minimal linger. It is set to 6sec specified
  42                                    in old IPv6 RFC. Well, it was reasonable value.
  43                                  */
  44 #define FL_MAX_LINGER   60      /* Maximal linger timeout */
  45
  46 /* FL hash table */
  47
  48 #define FL_MAX_PER_SOCK 32
  49 #define FL_MAX_SIZE     4096
  50 #define FL_HASH_MASK    255
  51 #define FL_HASH(l)      (ntohl(l)&FL_HASH_MASK)
  52
  53 static atomic_t fl_size = ATOMIC_INIT(0);
  54 static struct ip6_flowlabel __rcu *fl_ht[FL_HASH_MASK+1];
  55
  56 static void ip6_fl_gc(unsigned long dummy);
  57 static DEFINE_TIMER(ip6_fl_gc_timer, ip6_fl_gc, 0, 0);
  58
  59 /* FL hash table lock: it protects only of GC */
  60
  61 static DEFINE_SPINLOCK(ip6_fl_lock);
  62
  63 /* Big socket sock */
  64
  65 static DEFINE_SPINLOCK(ip6_sk_fl_lock);
  66
  67 #define for_each_fl_rcu(hash, fl)                               \
  68         for (fl = rcu_dereference_bh(fl_ht[(hash)]);            \
  69              fl != NULL;                                        \
  70              fl = rcu_dereference_bh(fl->next))
  71 #define for_each_fl_continue_rcu(fl)                            \
  72         for (fl = rcu_dereference_bh(fl->next);                 \
  73              fl != NULL;                                        \
  74              fl = rcu_dereference_bh(fl->next))
  75
  76 #define for_each_sk_fl_rcu(np, sfl)                             \
  77         for (sfl = rcu_dereference_bh(np->ipv6_fl_list);        \
  78              sfl != NULL;                                       \
  79              sfl = rcu_dereference_bh(sfl->next))
  80
  81 static inline struct ip6_flowlabel *__fl_lookup(struct net *net, __be32 label)
  82 {
  83         struct ip6_flowlabel *fl;
  84
  85         for_each_fl_rcu(FL_HASH(label), fl) {
  86                 if (fl->label == label && net_eq(fl->fl_net, net))
  87                         return fl;
  88         }
  89         return NULL;
  90 }
  91
  92 static struct ip6_flowlabel *fl_lookup(struct net *net, __be32 label)
  93 {
  94         struct ip6_flowlabel *fl;
  95
  96         rcu_read_lock_bh();
  97         fl = __fl_lookup(net, label);
  98         if (fl && !atomic_inc_not_zero(&fl->users))
  99                 fl = NULL;
 100         rcu_read_unlock_bh();
 101         return fl;
 102 }
 103
 104
 105 static void fl_free(struct ip6_flowlabel *fl)
 106 {
 107         if (fl) {
 108                 if (fl->share == IPV6_FL_S_PROCESS)
 109                         put_pid(fl->owner.pid);
 110                 release_net(fl->fl_net);
 111                 kfree(fl->opt);
 112                 kfree_rcu(fl, rcu);
 113         }
 114 }
 115
 116 static void fl_release(struct ip6_flowlabel *fl)
 117 {
 118         spin_lock_bh(&ip6_fl_lock);
 119
 120         fl->lastuse = jiffies;
 121         if (atomic_dec_and_test(&fl->users)) {
 122                 unsigned long ttd = fl->lastuse + fl->linger;
 123                 if (time_after(ttd, fl->expires))
 124                         fl->expires = ttd;
 125                 ttd = fl->expires;
 126                 if (fl->opt && fl->share == IPV6_FL_S_EXCL) {
 127                         struct ipv6_txoptions *opt = fl->opt;
 128                         fl->opt = NULL;
 129                         kfree(opt);
 130                 }
 131                 if (!timer_pending(&ip6_fl_gc_timer) ||
 132                     time_after(ip6_fl_gc_timer.expires, ttd))
 133                         mod_timer(&ip6_fl_gc_timer, ttd);
 134         }
 135         spin_unlock_bh(&ip6_fl_lock);
 136 }
 137
 138 static void ip6_fl_gc(unsigned long dummy)
 139 {
 140         int i;
 141         unsigned long now = jiffies;
 142         unsigned long sched = 0;
 143
 144         spin_lock(&ip6_fl_lock);
 145
 146         for (i=0; i<=FL_HASH_MASK; i++) {
 147                 struct ip6_flowlabel *fl, **flp;
 148                 flp = &fl_ht[i];
 149                 while ((fl = rcu_dereference_protected(*flp,
 150                                                        lockdep_is_held(&ip6_fl_lock))) != NULL) {
 151                         if (atomic_read(&fl->users) == 0) {
 152                                 unsigned long ttd = fl->lastuse + fl->linger;
 153                                 if (time_after(ttd, fl->expires))
 154                                         fl->expires = ttd;
 155                                 ttd = fl->expires;
 156                                 if (time_after_eq(now, ttd)) {
 157                                         *flp = fl->next;
 158                                         fl_free(fl);
 159                                         atomic_dec(&fl_size);
 160                                         continue;
 161                                 }
 162                                 if (!sched || time_before(ttd, sched))
 163                                         sched = ttd;
 164                         }
 165                         flp = &fl->next;
 166                 }
 167         }
 168         if (!sched && atomic_read(&fl_size))
 169                 sched = now + FL_MAX_LINGER;
 170         if (sched) {
 171                 mod_timer(&ip6_fl_gc_timer, sched);
 172         }
 173         spin_unlock(&ip6_fl_lock);
 174 }
 175
 176 static void __net_exit ip6_fl_purge(struct net *net)
 177 {
 178         int i;
 179
 180         spin_lock(&ip6_fl_lock);
 181         for (i = 0; i <= FL_HASH_MASK; i++) {
 182                 struct ip6_flowlabel *fl, **flp;
 183                 flp = &fl_ht[i];
 184                 while ((fl = rcu_dereference_protected(*flp,
 185                                                        lockdep_is_held(&ip6_fl_lock))) != NULL) {
 186                         if (net_eq(fl->fl_net, net) &&
 187                             atomic_read(&fl->users) == 0) {
 188                                 *flp = fl->next;
 189                                 fl_free(fl);
 190                                 atomic_dec(&fl_size);
 191                                 continue;
 192                         }
 193                         flp = &fl->next;
 194                 }
 195         }
 196         spin_unlock(&ip6_fl_lock);
 197 }
 198
 199 static struct ip6_flowlabel *fl_intern(struct net *net,
 200                                        struct ip6_flowlabel *fl, __be32 label)
 201 {
 202         struct ip6_flowlabel *lfl;
 203
 204         fl->label = label & IPV6_FLOWLABEL_MASK;
 205
 206         spin_lock_bh(&ip6_fl_lock);
 207         if (label == 0) {
 208                 for (;;) {
 209                         fl->label = htonl(net_random())&IPV6_FLOWLABEL_MASK;
 210                         if (fl->label) {
 211                                 lfl = __fl_lookup(net, fl->label);
 212                                 if (lfl == NULL)
 213                                         break;
 214                         }
 215                 }
 216         } else {
 217                 /*
 218                  * we dropper the ip6_fl_lock, so this entry could reappear
 219                  * and we need to recheck with it.
 220                  *
 221                  * OTOH no need to search the active socket first, like it is
 222                  * done in ipv6_flowlabel_opt - sock is locked, so new entry
 223                  * with the same label can only appear on another sock
 224                  */
 225                 lfl = __fl_lookup(net, fl->label);
 226                 if (lfl != NULL) {
 227                         atomic_inc(&lfl->users);
 228                         spin_unlock_bh(&ip6_fl_lock);
 229                         return lfl;
 230                 }
 231         }
 232
 233         fl->lastuse = jiffies;
 234         fl->next = fl_ht[FL_HASH(fl->label)];
 235         rcu_assign_pointer(fl_ht[FL_HASH(fl->label)], fl);
 236         atomic_inc(&fl_size);
 237         spin_unlock_bh(&ip6_fl_lock);
 238         return NULL;
 239 }
 240
 241
 242
 243 /* Socket flowlabel lists */
 244
 245 struct ip6_flowlabel * fl6_sock_lookup(struct sock *sk, __be32 label)
 246 {
 247         struct ipv6_fl_socklist *sfl;
 248         struct ipv6_pinfo *np = inet6_sk(sk);
 249
 250         label &= IPV6_FLOWLABEL_MASK;
 251
 252         rcu_read_lock_bh();
 253         for_each_sk_fl_rcu(np, sfl) {
 254                 struct ip6_flowlabel *fl = sfl->fl;
 255                 if (fl->label == label) {
 256                         fl->lastuse = jiffies;
 257                         atomic_inc(&fl->users);
 258                         rcu_read_unlock_bh();
 259                         return fl;
 260                 }
 261         }
 262         rcu_read_unlock_bh();
 263         return NULL;
 264 }
 265
 266 EXPORT_SYMBOL_GPL(fl6_sock_lookup);
 267
 268 void fl6_free_socklist(struct sock *sk)
 269 {
 270         struct ipv6_pinfo *np = inet6_sk(sk);
 271         struct ipv6_fl_socklist *sfl;
 272
 273         if (!rcu_access_pointer(np->ipv6_fl_list))
 274                 return;
 275
 276         spin_lock_bh(&ip6_sk_fl_lock);
 277         while ((sfl = rcu_dereference_protected(np->ipv6_fl_list,
 278                                                 lockdep_is_held(&ip6_sk_fl_lock))) != NULL) {
 279                 np->ipv6_fl_list = sfl->next;
 280                 spin_unlock_bh(&ip6_sk_fl_lock);
 281
 282                 fl_release(sfl->fl);
 283                 kfree_rcu(sfl, rcu);
 284
 285                 spin_lock_bh(&ip6_sk_fl_lock);
 286         }
 287         spin_unlock_bh(&ip6_sk_fl_lock);
 288 }
 289
 290 /* Service routines */
 291
 292
 293 /*
 294    It is the only difficult place. flowlabel enforces equal headers
 295    before and including routing header, however user may supply options
 296    following rthdr.
 297  */
 298
 299 struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions * opt_space,
 300                                          struct ip6_flowlabel * fl,
 301                                          struct ipv6_txoptions * fopt)
 302 {
 303         struct ipv6_txoptions * fl_opt = fl->opt;
 304
 305         if (fopt == NULL || fopt->opt_flen == 0)
 306                 return fl_opt;
 307
 308         if (fl_opt != NULL) {
 309                 opt_space->hopopt = fl_opt->hopopt;
 310                 opt_space->dst0opt = fl_opt->dst0opt;
 311                 opt_space->srcrt = fl_opt->srcrt;
 312                 opt_space->opt_nflen = fl_opt->opt_nflen;
 313         } else {
 314                 if (fopt->opt_nflen == 0)
 315                         return fopt;
 316                 opt_space->hopopt = NULL;
 317                 opt_space->dst0opt = NULL;
 318                 opt_space->srcrt = NULL;
 319                 opt_space->opt_nflen = 0;
 320         }
 321         opt_space->dst1opt = fopt->dst1opt;
 322         opt_space->opt_flen = fopt->opt_flen;
 323         return opt_space;
 324 }
 325 EXPORT_SYMBOL_GPL(fl6_merge_options);
 326
 327 static unsigned long check_linger(unsigned long ttl)
 328 {
 329         if (ttl < FL_MIN_LINGER)
 330                 return FL_MIN_LINGER*HZ;
 331         if (ttl > FL_MAX_LINGER && !capable(CAP_NET_ADMIN))
 332                 return 0;
 333         return ttl*HZ;
 334 }
 335
 336 static int fl6_renew(struct ip6_flowlabel *fl, unsigned long linger, unsigned long expires)
 337 {
 338         linger = check_linger(linger);
 339         if (!linger)
 340                 return -EPERM;
 341         expires = check_linger(expires);
 342         if (!expires)
 343                 return -EPERM;
 344         fl->lastuse = jiffies;
 345         if (time_before(fl->linger, linger))
 346                 fl->linger = linger;
 347         if (time_before(expires, fl->linger))
 348                 expires = fl->linger;
 349         if (time_before(fl->expires, fl->lastuse + expires))
 350                 fl->expires = fl->lastuse + expires;
 351         return 0;
 352 }
 353
 354 static struct ip6_flowlabel *
 355 fl_create(struct net *net, struct sock *sk, struct in6_flowlabel_req *freq,
 356           char __user *optval, int optlen, int *err_p)
 357 {
 358         struct ip6_flowlabel *fl = NULL;
 359         int olen;
 360         int addr_type;
 361         int err;
 362
 363         olen = optlen - CMSG_ALIGN(sizeof(*freq));
 364         err = -EINVAL;
 365         if (olen > 64 * 1024)
 366                 goto done;
 367
 368         err = -ENOMEM;
 369         fl = kzalloc(sizeof(*fl), GFP_KERNEL);
 370         if (fl == NULL)
 371                 goto done;
 372
 373         if (olen > 0) {
 374                 struct msghdr msg;
 375                 struct flowi6 flowi6;
 376                 int junk;
 377
 378                 err = -ENOMEM;
 379                 fl->opt = kmalloc(sizeof(*fl->opt) + olen, GFP_KERNEL);
 380                 if (fl->opt == NULL)
 381                         goto done;
 382
 383                 memset(fl->opt, 0, sizeof(*fl->opt));
 384                 fl->opt->tot_len = sizeof(*fl->opt) + olen;
 385                 err = -EFAULT;
 386                 if (copy_from_user(fl->opt+1, optval+CMSG_ALIGN(sizeof(*freq)), olen))
 387                         goto done;
 388
 389                 msg.msg_controllen = olen;
 390                 msg.msg_control = (void*)(fl->opt+1);
 391                 memset(&flowi6, 0, sizeof(flowi6));
 392
 393                 err = ip6_datagram_send_ctl(net, sk, &msg, &flowi6, fl->opt,
 394                                             &junk, &junk, &junk);
 395                 if (err)
 396                         goto done;
 397                 err = -EINVAL;
 398                 if (fl->opt->opt_flen)
 399                         goto done;
 400                 if (fl->opt->opt_nflen == 0) {
 401                         kfree(fl->opt);
 402                         fl->opt = NULL;
 403                 }
 404         }
 405
 406         fl->fl_net = hold_net(net);
 407         fl->expires = jiffies;
 408         err = fl6_renew(fl, freq->flr_linger, freq->flr_expires);
 409         if (err)
 410                 goto done;
 411         fl->share = freq->flr_share;
 412         addr_type = ipv6_addr_type(&freq->flr_dst);
 413         if ((addr_type & IPV6_ADDR_MAPPED) ||
 414             addr_type == IPV6_ADDR_ANY) {
 415                 err = -EINVAL;
 416                 goto done;
 417         }
 418         fl->dst = freq->flr_dst;
 419         atomic_set(&fl->users, 1);
 420         switch (fl->share) {
 421         case IPV6_FL_S_EXCL:
 422         case IPV6_FL_S_ANY:
 423                 break;
 424         case IPV6_FL_S_PROCESS:
 425                 fl->owner.pid = get_task_pid(current, PIDTYPE_PID);
 426                 break;
 427         case IPV6_FL_S_USER:
 428                 fl->owner.uid = current_euid();
 429                 break;
 430         default:
 431                 err = -EINVAL;
 432                 goto done;
 433         }
 434         return fl;
 435
 436 done:
 437         fl_free(fl);
 438         *err_p = err;
 439         return NULL;
 440 }
 441
 442 static int mem_check(struct sock *sk)
 443 {
 444         struct ipv6_pinfo *np = inet6_sk(sk);
 445         struct ipv6_fl_socklist *sfl;
 446         int room = FL_MAX_SIZE - atomic_read(&fl_size);
 447         int count = 0;
 448
 449         if (room > FL_MAX_SIZE - FL_MAX_PER_SOCK)
 450                 return 0;
 451
 452         for_each_sk_fl_rcu(np, sfl)
 453                 count++;
 454
 455         if (room <= 0 ||
 456             ((count >= FL_MAX_PER_SOCK ||
 457               (count > 0 && room < FL_MAX_SIZE/2) || room < FL_MAX_SIZE/4) &&
 458              !capable(CAP_NET_ADMIN)))
 459                 return -ENOBUFS;
 460
 461         return 0;
 462 }
 463
 464 static bool ipv6_hdr_cmp(struct ipv6_opt_hdr *h1, struct ipv6_opt_hdr *h2)
 465 {
 466         if (h1 == h2)
 467                 return false;
 468         if (h1 == NULL || h2 == NULL)
 469                 return true;
 470         if (h1->hdrlen != h2->hdrlen)
 471                 return true;
 472         return memcmp(h1+1, h2+1, ((h1->hdrlen+1)<<3) - sizeof(*h1));
 473 }
 474
 475 static bool ipv6_opt_cmp(struct ipv6_txoptions *o1, struct ipv6_txoptions *o2)
 476 {
 477         if (o1 == o2)
 478                 return false;
 479         if (o1 == NULL || o2 == NULL)
 480                 return true;
 481         if (o1->opt_nflen != o2->opt_nflen)
 482                 return true;
 483         if (ipv6_hdr_cmp(o1->hopopt, o2->hopopt))
 484                 return true;
 485         if (ipv6_hdr_cmp(o1->dst0opt, o2->dst0opt))
 486                 return true;
 487         if (ipv6_hdr_cmp((struct ipv6_opt_hdr *)o1->srcrt, (struct ipv6_opt_hdr *)o2->srcrt))
 488                 return true;
 489         return false;
 490 }
 491
 492 static inline void fl_link(struct ipv6_pinfo *np, struct ipv6_fl_socklist *sfl,
 493                 struct ip6_flowlabel *fl)
 494 {
 495         spin_lock_bh(&ip6_sk_fl_lock);
 496         sfl->fl = fl;
 497         sfl->next = np->ipv6_fl_list;
 498         rcu_assign_pointer(np->ipv6_fl_list, sfl);
 499         spin_unlock_bh(&ip6_sk_fl_lock);
 500 }
 501
 502 int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen)
 503 {
 504         int uninitialized_var(err);
 505         struct net *net = sock_net(sk);
 506         struct ipv6_pinfo *np = inet6_sk(sk);
 507         struct in6_flowlabel_req freq;
 508         struct ipv6_fl_socklist *sfl1=NULL;
 509         struct ipv6_fl_socklist *sfl, **sflp;
 510         struct ip6_flowlabel *fl, *fl1 = NULL;
 511
 512
 513         if (optlen < sizeof(freq))
 514                 return -EINVAL;
 515
 516         if (copy_from_user(&freq, optval, sizeof(freq)))
 517                 return -EFAULT;
 518
 519         switch (freq.flr_action) {
 520         case IPV6_FL_A_PUT:
 521                 spin_lock_bh(&ip6_sk_fl_lock);
 522                 for (sflp = &np->ipv6_fl_list;
 523                      (sfl = rcu_dereference(*sflp))!=NULL;
 524                      sflp = &sfl->next) {
 525                         if (sfl->fl->label == freq.flr_label) {
 526                                 if (freq.flr_label == (np->flow_label&IPV6_FLOWLABEL_MASK))
 527                                         np->flow_label &= ~IPV6_FLOWLABEL_MASK;
 528                                 *sflp = rcu_dereference(sfl->next);
 529                                 spin_unlock_bh(&ip6_sk_fl_lock);
 530                                 fl_release(sfl->fl);
 531                                 kfree_rcu(sfl, rcu);
 532                                 return 0;
 533                         }
 534                 }
 535                 spin_unlock_bh(&ip6_sk_fl_lock);
 536                 return -ESRCH;
 537
 538         case IPV6_FL_A_RENEW:
 539                 rcu_read_lock_bh();
 540                 for_each_sk_fl_rcu(np, sfl) {
 541                         if (sfl->fl->label == freq.flr_label) {
 542                                 err = fl6_renew(sfl->fl, freq.flr_linger, freq.flr_expires);
 543                                 rcu_read_unlock_bh();
 544                                 return err;
 545                         }
 546                 }
 547                 rcu_read_unlock_bh();
 548
 549                 if (freq.flr_share == IPV6_FL_S_NONE &&
 550                     ns_capable(net->user_ns, CAP_NET_ADMIN)) {
 551                         fl = fl_lookup(net, freq.flr_label);
 552                         if (fl) {
 553                                 err = fl6_renew(fl, freq.flr_linger, freq.flr_expires);
 554                                 fl_release(fl);
 555                                 return err;
 556                         }
 557                 }
 558                 return -ESRCH;
 559
 560         case IPV6_FL_A_GET:
 561                 if (freq.flr_label & ~IPV6_FLOWLABEL_MASK)
 562                         return -EINVAL;
 563
 564                 fl = fl_create(net, sk, &freq, optval, optlen, &err);
 565                 if (fl == NULL)
 566                         return err;
 567                 sfl1 = kmalloc(sizeof(*sfl1), GFP_KERNEL);
 568
 569                 if (freq.flr_label) {
 570                         err = -EEXIST;
 571                         rcu_read_lock_bh();
 572                         for_each_sk_fl_rcu(np, sfl) {
 573                                 if (sfl->fl->label == freq.flr_label) {
 574                                         if (freq.flr_flags&IPV6_FL_F_EXCL) {
 575                                                 rcu_read_unlock_bh();
 576                                                 goto done;
 577                                         }
 578                                         fl1 = sfl->fl;
 579                                         atomic_inc(&fl1->users);
 580                                         break;
 581                                 }
 582                         }
 583                         rcu_read_unlock_bh();
 584
 585                         if (fl1 == NULL)
 586                                 fl1 = fl_lookup(net, freq.flr_label);
 587                         if (fl1) {
 588 recheck:
 589                                 err = -EEXIST;
 590                                 if (freq.flr_flags&IPV6_FL_F_EXCL)
 591                                         goto release;
 592                                 err = -EPERM;
 593                                 if (fl1->share == IPV6_FL_S_EXCL ||
 594                                     fl1->share != fl->share ||
 595                                     ((fl1->share == IPV6_FL_S_PROCESS) &&
 596                                      (fl1->owner.pid == fl->owner.pid)) ||
 597                                     ((fl1->share == IPV6_FL_S_USER) &&
 598                                      uid_eq(fl1->owner.uid, fl->owner.uid)))
 599                                         goto release;
 600
 601                                 err = -EINVAL;
 602                                 if (!ipv6_addr_equal(&fl1->dst, &fl->dst) ||
 603                                     ipv6_opt_cmp(fl1->opt, fl->opt))
 604                                         goto release;
 605
 606                                 err = -ENOMEM;
 607                                 if (sfl1 == NULL)
 608                                         goto release;
 609                                 if (fl->linger > fl1->linger)
 610                                         fl1->linger = fl->linger;
 611                                 if ((long)(fl->expires - fl1->expires) > 0)
 612                                         fl1->expires = fl->expires;
 613                                 fl_link(np, sfl1, fl1);
 614                                 fl_free(fl);
 615                                 return 0;
 616
 617 release:
 618                                 fl_release(fl1);
 619                                 goto done;
 620                         }
 621                 }
 622                 err = -ENOENT;
 623                 if (!(freq.flr_flags&IPV6_FL_F_CREATE))
 624                         goto done;
 625
 626                 err = -ENOMEM;
 627                 if (sfl1 == NULL || (err = mem_check(sk)) != 0)
 628                         goto done;
 629
 630                 fl1 = fl_intern(net, fl, freq.flr_label);
 631                 if (fl1 != NULL)
 632                         goto recheck;
 633
 634                 if (!freq.flr_label) {
 635                         if (copy_to_user(&((struct in6_flowlabel_req __user *) optval)->flr_label,
 636                                          &fl->label, sizeof(fl->label))) {
 637                                 /* Intentionally ignore fault. */
 638                         }
 639                 }
 640
 641                 fl_link(np, sfl1, fl);
 642                 return 0;
 643
 644         default:
 645                 return -EINVAL;
 646         }
 647
 648 done:
 649         fl_free(fl);
 650         kfree(sfl1);
 651         return err;
 652 }
 653
 654 #ifdef CONFIG_PROC_FS
 655
 656 struct ip6fl_iter_state {
 657         struct seq_net_private p;
 658         struct pid_namespace *pid_ns;
 659         int bucket;
 660 };
 661
 662 #define ip6fl_seq_private(seq)  ((struct ip6fl_iter_state *)(seq)->private)
 663
 664 static struct ip6_flowlabel *ip6fl_get_first(struct seq_file *seq)
 665 {
 666         struct ip6_flowlabel *fl = NULL;
 667         struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 668         struct net *net = seq_file_net(seq);
 669
 670         for (state->bucket = 0; state->bucket <= FL_HASH_MASK; ++state->bucket) {
 671                 for_each_fl_rcu(state->bucket, fl) {
 672                         if (net_eq(fl->fl_net, net))
 673                                 goto out;
 674                 }
 675         }
 676         fl = NULL;
 677 out:
 678         return fl;
 679 }
 680
 681 static struct ip6_flowlabel *ip6fl_get_next(struct seq_file *seq, struct ip6_flowlabel *fl)
 682 {
 683         struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 684         struct net *net = seq_file_net(seq);
 685
 686         for_each_fl_continue_rcu(fl) {
 687                 if (net_eq(fl->fl_net, net))
 688                         goto out;
 689         }
 690
 691 try_again:
 692         if (++state->bucket <= FL_HASH_MASK) {
 693                 for_each_fl_rcu(state->bucket, fl) {
 694                         if (net_eq(fl->fl_net, net))
 695                                 goto out;
 696                 }
 697                 goto try_again;
 698         }
 699         fl = NULL;
 700
 701 out:
 702         return fl;
 703 }
 704
 705 static struct ip6_flowlabel *ip6fl_get_idx(struct seq_file *seq, loff_t pos)
 706 {
 707         struct ip6_flowlabel *fl = ip6fl_get_first(seq);
 708         if (fl)
 709                 while (pos && (fl = ip6fl_get_next(seq, fl)) != NULL)
 710                         --pos;
 711         return pos ? NULL : fl;
 712 }
 713
 714 static void *ip6fl_seq_start(struct seq_file *seq, loff_t *pos)
 715         __acquires(RCU)
 716 {
 717         rcu_read_lock_bh();
 718         return *pos ? ip6fl_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
 719 }
 720
 721 static void *ip6fl_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 722 {
 723         struct ip6_flowlabel *fl;
 724
 725         if (v == SEQ_START_TOKEN)
 726                 fl = ip6fl_get_first(seq);
 727         else
 728                 fl = ip6fl_get_next(seq, v);
 729         ++*pos;
 730         return fl;
 731 }
 732
 733 static void ip6fl_seq_stop(struct seq_file *seq, void *v)
 734         __releases(RCU)
 735 {
 736         rcu_read_unlock_bh();
 737 }
 738
 739 static int ip6fl_seq_show(struct seq_file *seq, void *v)
 740 {
 741         struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 742         if (v == SEQ_START_TOKEN)
 743                 seq_printf(seq, "%-5s %-1s %-6s %-6s %-6s %-8s %-32s %s\n",
 744                            "Label", "S", "Owner", "Users", "Linger", "Expires", "Dst", "Opt");
 745         else {
 746                 struct ip6_flowlabel *fl = v;
 747                 seq_printf(seq,
 748                            "%05X %-1d %-6d %-6d %-6ld %-8ld %pi6 %-4d\n",
 749                            (unsigned int)ntohl(fl->label),
 750                            fl->share,
 751                            ((fl->share == IPV6_FL_S_PROCESS) ?
 752                             pid_nr_ns(fl->owner.pid, state->pid_ns) :
 753                             ((fl->share == IPV6_FL_S_USER) ?
 754                              from_kuid_munged(seq_user_ns(seq), fl->owner.uid) :
 755                              0)),
 756                            atomic_read(&fl->users),
 757                            fl->linger/HZ,
 758                            (long)(fl->expires - jiffies)/HZ,
 759                            &fl->dst,
 760                            fl->opt ? fl->opt->opt_nflen : 0);
 761         }
 762         return 0;
 763 }
 764
 765 static const struct seq_operations ip6fl_seq_ops = {
 766         .start  =       ip6fl_seq_start,
 767         .next   =       ip6fl_seq_next,
 768         .stop   =       ip6fl_seq_stop,
 769         .show   =       ip6fl_seq_show,
 770 };
 771
 772 static int ip6fl_seq_open(struct inode *inode, struct file *file)
 773 {
 774         struct seq_file *seq;
 775         struct ip6fl_iter_state *state;
 776         int err;
 777
 778         err = seq_open_net(inode, file, &ip6fl_seq_ops,
 779                            sizeof(struct ip6fl_iter_state));
 780
 781         if (!err) {
 782                 seq = file->private_data;
 783                 state = ip6fl_seq_private(seq);
 784                 rcu_read_lock();
 785                 state->pid_ns = get_pid_ns(task_active_pid_ns(current));
 786                 rcu_read_unlock();
 787         }
 788         return err;
 789 }
 790
 791 static int ip6fl_seq_release(struct inode *inode, struct file *file)
 792 {
 793         struct seq_file *seq = file->private_data;
 794         struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 795         put_pid_ns(state->pid_ns);
 796         return seq_release_net(inode, file);
 797 }
 798
 799 static const struct file_operations ip6fl_seq_fops = {
 800         .owner          =       THIS_MODULE,
 801         .open           =       ip6fl_seq_open,
 802         .read           =       seq_read,
 803         .llseek         =       seq_lseek,
 804         .release        =       ip6fl_seq_release,
 805 };
 806
 807 static int __net_init ip6_flowlabel_proc_init(struct net *net)
 808 {
 809         if (!proc_net_fops_create(net, "ip6_flowlabel",
 810                                   S_IRUGO, &ip6fl_seq_fops))
 811                 return -ENOMEM;
 812         return 0;
 813 }
 814
 815 static void __net_exit ip6_flowlabel_proc_fini(struct net *net)
 816 {
 817         proc_net_remove(net, "ip6_flowlabel");
 818 }
 819 #else
 820 static inline int ip6_flowlabel_proc_init(struct net *net)
 821 {
 822         return 0;
 823 }
 824 static inline void ip6_flowlabel_proc_fini(struct net *net)
 825 {
 826 }
 827 #endif
 828
 829 static void __net_exit ip6_flowlabel_net_exit(struct net *net)
 830 {
 831         ip6_fl_purge(net);
 832         ip6_flowlabel_proc_fini(net);
 833 }
 834
 835 static struct pernet_operations ip6_flowlabel_net_ops = {
 836         .init = ip6_flowlabel_proc_init,
 837         .exit = ip6_flowlabel_net_exit,
 838 };
 839
 840 int ip6_flowlabel_init(void)
 841 {
 842         return register_pernet_subsys(&ip6_flowlabel_net_ops);
 843 }
 844
 845 void ip6_flowlabel_cleanup(void)
 846 {
 847         del_timer(&ip6_fl_gc_timer);
 848         unregister_pernet_subsys(&ip6_flowlabel_net_ops);
 849 }