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/in6.h>
  19 #include <linux/proc_fs.h>
  20 #include <linux/seq_file.h>
  21 #include <linux/slab.h>
  22 #include <linux/export.h>
  23 #include <linux/pid_namespace.h>
  24
  25 #include <net/net_namespace.h>
  26 #include <net/sock.h>
  27
  28 #include <net/ipv6.h>
  29 #include <net/rawv6.h>
  30 #include <net/transp_v6.h>
  31
  32 #include <asm/uaccess.h>
  33
  34 #define FL_MIN_LINGER   6       /* Minimal linger. It is set to 6sec specified
  35                                    in old IPv6 RFC. Well, it was reasonable value.
  36                                  */
  37 #define FL_MAX_LINGER   150     /* Maximal linger timeout */
  38
  39 /* FL hash table */
  40
  41 #define FL_MAX_PER_SOCK 32
  42 #define FL_MAX_SIZE     4096
  43 #define FL_HASH_MASK    255
  44 #define FL_HASH(l)      (ntohl(l)&FL_HASH_MASK)
  45
  46 static atomic_t fl_size = ATOMIC_INIT(0);
  47 static struct ip6_flowlabel __rcu *fl_ht[FL_HASH_MASK+1];
  48
  49 static void ip6_fl_gc(unsigned long dummy);
  50 static DEFINE_TIMER(ip6_fl_gc_timer, ip6_fl_gc, 0, 0);
  51
  52 /* FL hash table lock: it protects only of GC */
  53
  54 static DEFINE_SPINLOCK(ip6_fl_lock);
  55
  56 /* Big socket sock */
  57
  58 static DEFINE_SPINLOCK(ip6_sk_fl_lock);
  59
  60 #define for_each_fl_rcu(hash, fl)                               \
  61         for (fl = rcu_dereference_bh(fl_ht[(hash)]);            \
  62              fl != NULL;                                        \
  63              fl = rcu_dereference_bh(fl->next))
  64 #define for_each_fl_continue_rcu(fl)                            \
  65         for (fl = rcu_dereference_bh(fl->next);                 \
  66              fl != NULL;                                        \
  67              fl = rcu_dereference_bh(fl->next))
  68
  69 #define for_each_sk_fl_rcu(np, sfl)                             \
  70         for (sfl = rcu_dereference_bh(np->ipv6_fl_list);        \
  71              sfl != NULL;                                       \
  72              sfl = rcu_dereference_bh(sfl->next))
  73
  74 static inline struct ip6_flowlabel *__fl_lookup(struct net *net, __be32 label)
  75 {
  76         struct ip6_flowlabel *fl;
  77
  78         for_each_fl_rcu(FL_HASH(label), fl) {
  79                 if (fl->label == label && net_eq(fl->fl_net, net))
  80                         return fl;
  81         }
  82         return NULL;
  83 }
  84
  85 static struct ip6_flowlabel *fl_lookup(struct net *net, __be32 label)
  86 {
  87         struct ip6_flowlabel *fl;
  88
  89         rcu_read_lock_bh();
  90         fl = __fl_lookup(net, label);
  91         if (fl && !atomic_inc_not_zero(&fl->users))
  92                 fl = NULL;
  93         rcu_read_unlock_bh();
  94         return fl;
  95 }
  96
  97
  98 static void fl_free(struct ip6_flowlabel *fl)
  99 {
 100         if (fl) {
 101                 if (fl->share == IPV6_FL_S_PROCESS)
 102                         put_pid(fl->owner.pid);
 103                 kfree(fl->opt);
 104                 kfree_rcu(fl, rcu);
 105         }
 106 }
 107
 108 static void fl_release(struct ip6_flowlabel *fl)
 109 {
 110         spin_lock_bh(&ip6_fl_lock);
 111
 112         fl->lastuse = jiffies;
 113         if (atomic_dec_and_test(&fl->users)) {
 114                 unsigned long ttd = fl->lastuse + fl->linger;
 115                 if (time_after(ttd, fl->expires))
 116                         fl->expires = ttd;
 117                 ttd = fl->expires;
 118                 if (fl->opt && fl->share == IPV6_FL_S_EXCL) {
 119                         struct ipv6_txoptions *opt = fl->opt;
 120                         fl->opt = NULL;
 121                         kfree(opt);
 122                 }
 123                 if (!timer_pending(&ip6_fl_gc_timer) ||
 124                     time_after(ip6_fl_gc_timer.expires, ttd))
 125                         mod_timer(&ip6_fl_gc_timer, ttd);
 126         }
 127         spin_unlock_bh(&ip6_fl_lock);
 128 }
 129
 130 static void ip6_fl_gc(unsigned long dummy)
 131 {
 132         int i;
 133         unsigned long now = jiffies;
 134         unsigned long sched = 0;
 135
 136         spin_lock(&ip6_fl_lock);
 137
 138         for (i = 0; i <= FL_HASH_MASK; i++) {
 139                 struct ip6_flowlabel *fl;
 140                 struct ip6_flowlabel __rcu **flp;
 141
 142                 flp = &fl_ht[i];
 143                 while ((fl = rcu_dereference_protected(*flp,
 144                                                        lockdep_is_held(&ip6_fl_lock))) != NULL) {
 145                         if (atomic_read(&fl->users) == 0) {
 146                                 unsigned long ttd = fl->lastuse + fl->linger;
 147                                 if (time_after(ttd, fl->expires))
 148                                         fl->expires = ttd;
 149                                 ttd = fl->expires;
 150                                 if (time_after_eq(now, ttd)) {
 151                                         *flp = fl->next;
 152                                         fl_free(fl);
 153                                         atomic_dec(&fl_size);
 154                                         continue;
 155                                 }
 156                                 if (!sched || time_before(ttd, sched))
 157                                         sched = ttd;
 158                         }
 159                         flp = &fl->next;
 160                 }
 161         }
 162         if (!sched && atomic_read(&fl_size))
 163                 sched = now + FL_MAX_LINGER;
 164         if (sched) {
 165                 mod_timer(&ip6_fl_gc_timer, sched);
 166         }
 167         spin_unlock(&ip6_fl_lock);
 168 }
 169
 170 static void __net_exit ip6_fl_purge(struct net *net)
 171 {
 172         int i;
 173
 174         spin_lock_bh(&ip6_fl_lock);
 175         for (i = 0; i <= FL_HASH_MASK; i++) {
 176                 struct ip6_flowlabel *fl;
 177                 struct ip6_flowlabel __rcu **flp;
 178
 179                 flp = &fl_ht[i];
 180                 while ((fl = rcu_dereference_protected(*flp,
 181                                                        lockdep_is_held(&ip6_fl_lock))) != NULL) {
 182                         if (net_eq(fl->fl_net, net) &&
 183                             atomic_read(&fl->users) == 0) {
 184                                 *flp = fl->next;
 185                                 fl_free(fl);
 186                                 atomic_dec(&fl_size);
 187                                 continue;
 188                         }
 189                         flp = &fl->next;
 190                 }
 191         }
 192         spin_unlock_bh(&ip6_fl_lock);
 193 }
 194
 195 static struct ip6_flowlabel *fl_intern(struct net *net,
 196                                        struct ip6_flowlabel *fl, __be32 label)
 197 {
 198         struct ip6_flowlabel *lfl;
 199
 200         fl->label = label & IPV6_FLOWLABEL_MASK;
 201
 202         spin_lock_bh(&ip6_fl_lock);
 203         if (label == 0) {
 204                 for (;;) {
 205                         fl->label = htonl(prandom_u32())&IPV6_FLOWLABEL_MASK;
 206                         if (fl->label) {
 207                                 lfl = __fl_lookup(net, fl->label);
 208                                 if (!lfl)
 209                                         break;
 210                         }
 211                 }
 212         } else {
 213                 /*
 214                  * we dropper the ip6_fl_lock, so this entry could reappear
 215                  * and we need to recheck with it.
 216                  *
 217                  * OTOH no need to search the active socket first, like it is
 218                  * done in ipv6_flowlabel_opt - sock is locked, so new entry
 219                  * with the same label can only appear on another sock
 220                  */
 221                 lfl = __fl_lookup(net, fl->label);
 222                 if (lfl) {
 223                         atomic_inc(&lfl->users);
 224                         spin_unlock_bh(&ip6_fl_lock);
 225                         return lfl;
 226                 }
 227         }
 228
 229         fl->lastuse = jiffies;
 230         fl->next = fl_ht[FL_HASH(fl->label)];
 231         rcu_assign_pointer(fl_ht[FL_HASH(fl->label)], fl);
 232         atomic_inc(&fl_size);
 233         spin_unlock_bh(&ip6_fl_lock);
 234         return NULL;
 235 }
 236
 237
 238
 239 /* Socket flowlabel lists */
 240
 241 struct ip6_flowlabel *fl6_sock_lookup(struct sock *sk, __be32 label)
 242 {
 243         struct ipv6_fl_socklist *sfl;
 244         struct ipv6_pinfo *np = inet6_sk(sk);
 245
 246         label &= IPV6_FLOWLABEL_MASK;
 247
 248         rcu_read_lock_bh();
 249         for_each_sk_fl_rcu(np, sfl) {
 250                 struct ip6_flowlabel *fl = sfl->fl;
 251                 if (fl->label == label) {
 252                         fl->lastuse = jiffies;
 253                         atomic_inc(&fl->users);
 254                         rcu_read_unlock_bh();
 255                         return fl;
 256                 }
 257         }
 258         rcu_read_unlock_bh();
 259         return NULL;
 260 }
 261 EXPORT_SYMBOL_GPL(fl6_sock_lookup);
 262
 263 void fl6_free_socklist(struct sock *sk)
 264 {
 265         struct ipv6_pinfo *np = inet6_sk(sk);
 266         struct ipv6_fl_socklist *sfl;
 267
 268         if (!rcu_access_pointer(np->ipv6_fl_list))
 269                 return;
 270
 271         spin_lock_bh(&ip6_sk_fl_lock);
 272         while ((sfl = rcu_dereference_protected(np->ipv6_fl_list,
 273                                                 lockdep_is_held(&ip6_sk_fl_lock))) != NULL) {
 274                 np->ipv6_fl_list = sfl->next;
 275                 spin_unlock_bh(&ip6_sk_fl_lock);
 276
 277                 fl_release(sfl->fl);
 278                 kfree_rcu(sfl, rcu);
 279
 280                 spin_lock_bh(&ip6_sk_fl_lock);
 281         }
 282         spin_unlock_bh(&ip6_sk_fl_lock);
 283 }
 284
 285 /* Service routines */
 286
 287
 288 /*
 289    It is the only difficult place. flowlabel enforces equal headers
 290    before and including routing header, however user may supply options
 291    following rthdr.
 292  */
 293
 294 struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions *opt_space,
 295                                          struct ip6_flowlabel *fl,
 296                                          struct ipv6_txoptions *fopt)
 297 {
 298         struct ipv6_txoptions *fl_opt = fl->opt;
 299
 300         if (!fopt || fopt->opt_flen == 0)
 301                 return fl_opt;
 302
 303         if (fl_opt) {
 304                 opt_space->hopopt = fl_opt->hopopt;
 305                 opt_space->dst0opt = fl_opt->dst0opt;
 306                 opt_space->srcrt = fl_opt->srcrt;
 307                 opt_space->opt_nflen = fl_opt->opt_nflen;
 308         } else {
 309                 if (fopt->opt_nflen == 0)
 310                         return fopt;
 311                 opt_space->hopopt = NULL;
 312                 opt_space->dst0opt = NULL;
 313                 opt_space->srcrt = NULL;
 314                 opt_space->opt_nflen = 0;
 315         }
 316         opt_space->dst1opt = fopt->dst1opt;
 317         opt_space->opt_flen = fopt->opt_flen;
 318         return opt_space;
 319 }
 320 EXPORT_SYMBOL_GPL(fl6_merge_options);
 321
 322 static unsigned long check_linger(unsigned long ttl)
 323 {
 324         if (ttl < FL_MIN_LINGER)
 325                 return FL_MIN_LINGER*HZ;
 326         if (ttl > FL_MAX_LINGER && !capable(CAP_NET_ADMIN))
 327                 return 0;
 328         return ttl*HZ;
 329 }
 330
 331 static int fl6_renew(struct ip6_flowlabel *fl, unsigned long linger, unsigned long expires)
 332 {
 333         linger = check_linger(linger);
 334         if (!linger)
 335                 return -EPERM;
 336         expires = check_linger(expires);
 337         if (!expires)
 338                 return -EPERM;
 339
 340         spin_lock_bh(&ip6_fl_lock);
 341         fl->lastuse = jiffies;
 342         if (time_before(fl->linger, linger))
 343                 fl->linger = linger;
 344         if (time_before(expires, fl->linger))
 345                 expires = fl->linger;
 346         if (time_before(fl->expires, fl->lastuse + expires))
 347                 fl->expires = fl->lastuse + expires;
 348         spin_unlock_bh(&ip6_fl_lock);
 349
 350         return 0;
 351 }
 352
 353 static struct ip6_flowlabel *
 354 fl_create(struct net *net, struct sock *sk, struct in6_flowlabel_req *freq,
 355           char __user *optval, int optlen, int *err_p)
 356 {
 357         struct ip6_flowlabel *fl = NULL;
 358         int olen;
 359         int addr_type;
 360         int err;
 361
 362         olen = optlen - CMSG_ALIGN(sizeof(*freq));
 363         err = -EINVAL;
 364         if (olen > 64 * 1024)
 365                 goto done;
 366
 367         err = -ENOMEM;
 368         fl = kzalloc(sizeof(*fl), GFP_KERNEL);
 369         if (!fl)
 370                 goto done;
 371
 372         if (olen > 0) {
 373                 struct msghdr msg;
 374                 struct flowi6 flowi6;
 375                 int junk;
 376
 377                 err = -ENOMEM;
 378                 fl->opt = kmalloc(sizeof(*fl->opt) + olen, GFP_KERNEL);
 379                 if (!fl->opt)
 380                         goto done;
 381
 382                 memset(fl->opt, 0, sizeof(*fl->opt));
 383                 fl->opt->tot_len = sizeof(*fl->opt) + olen;
 384                 err = -EFAULT;
 385                 if (copy_from_user(fl->opt+1, optval+CMSG_ALIGN(sizeof(*freq)), olen))
 386                         goto done;
 387
 388                 msg.msg_controllen = olen;
 389                 msg.msg_control = (void *)(fl->opt+1);
 390                 memset(&flowi6, 0, sizeof(flowi6));
 391
 392                 err = ip6_datagram_send_ctl(net, sk, &msg, &flowi6, fl->opt,
 393                                             &junk, &junk, &junk);
 394                 if (err)
 395                         goto done;
 396                 err = -EINVAL;
 397                 if (fl->opt->opt_flen)
 398                         goto done;
 399                 if (fl->opt->opt_nflen == 0) {
 400                         kfree(fl->opt);
 401                         fl->opt = NULL;
 402                 }
 403         }
 404
 405         fl->fl_net = net;
 406         fl->expires = jiffies;
 407         err = fl6_renew(fl, freq->flr_linger, freq->flr_expires);
 408         if (err)
 409                 goto done;
 410         fl->share = freq->flr_share;
 411         addr_type = ipv6_addr_type(&freq->flr_dst);
 412         if ((addr_type & IPV6_ADDR_MAPPED) ||
 413             addr_type == IPV6_ADDR_ANY) {
 414                 err = -EINVAL;
 415                 goto done;
 416         }
 417         fl->dst = freq->flr_dst;
 418         atomic_set(&fl->users, 1);
 419         switch (fl->share) {
 420         case IPV6_FL_S_EXCL:
 421         case IPV6_FL_S_ANY:
 422                 break;
 423         case IPV6_FL_S_PROCESS:
 424                 fl->owner.pid = get_task_pid(current, PIDTYPE_PID);
 425                 break;
 426         case IPV6_FL_S_USER:
 427                 fl->owner.uid = current_euid();
 428                 break;
 429         default:
 430                 err = -EINVAL;
 431                 goto done;
 432         }
 433         return fl;
 434
 435 done:
 436         fl_free(fl);
 437         *err_p = err;
 438         return NULL;
 439 }
 440
 441 static int mem_check(struct sock *sk)
 442 {
 443         struct ipv6_pinfo *np = inet6_sk(sk);
 444         struct ipv6_fl_socklist *sfl;
 445         int room = FL_MAX_SIZE - atomic_read(&fl_size);
 446         int count = 0;
 447
 448         if (room > FL_MAX_SIZE - FL_MAX_PER_SOCK)
 449                 return 0;
 450
 451         rcu_read_lock_bh();
 452         for_each_sk_fl_rcu(np, sfl)
 453                 count++;
 454         rcu_read_unlock_bh();
 455
 456         if (room <= 0 ||
 457             ((count >= FL_MAX_PER_SOCK ||
 458               (count > 0 && room < FL_MAX_SIZE/2) || room < FL_MAX_SIZE/4) &&
 459              !capable(CAP_NET_ADMIN)))
 460                 return -ENOBUFS;
 461
 462         return 0;
 463 }
 464
 465 static inline void fl_link(struct ipv6_pinfo *np, struct ipv6_fl_socklist *sfl,
 466                 struct ip6_flowlabel *fl)
 467 {
 468         spin_lock_bh(&ip6_sk_fl_lock);
 469         sfl->fl = fl;
 470         sfl->next = np->ipv6_fl_list;
 471         rcu_assign_pointer(np->ipv6_fl_list, sfl);
 472         spin_unlock_bh(&ip6_sk_fl_lock);
 473 }
 474
 475 int ipv6_flowlabel_opt_get(struct sock *sk, struct in6_flowlabel_req *freq,
 476                            int flags)
 477 {
 478         struct ipv6_pinfo *np = inet6_sk(sk);
 479         struct ipv6_fl_socklist *sfl;
 480
 481         if (flags & IPV6_FL_F_REMOTE) {
 482                 freq->flr_label = np->rcv_flowinfo & IPV6_FLOWLABEL_MASK;
 483                 return 0;
 484         }
 485
 486         if (np->repflow) {
 487                 freq->flr_label = np->flow_label;
 488                 return 0;
 489         }
 490
 491         rcu_read_lock_bh();
 492
 493         for_each_sk_fl_rcu(np, sfl) {
 494                 if (sfl->fl->label == (np->flow_label & IPV6_FLOWLABEL_MASK)) {
 495                         spin_lock_bh(&ip6_fl_lock);
 496                         freq->flr_label = sfl->fl->label;
 497                         freq->flr_dst = sfl->fl->dst;
 498                         freq->flr_share = sfl->fl->share;
 499                         freq->flr_expires = (sfl->fl->expires - jiffies) / HZ;
 500                         freq->flr_linger = sfl->fl->linger / HZ;
 501
 502                         spin_unlock_bh(&ip6_fl_lock);
 503                         rcu_read_unlock_bh();
 504                         return 0;
 505                 }
 506         }
 507         rcu_read_unlock_bh();
 508
 509         return -ENOENT;
 510 }
 511
 512 int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen)
 513 {
 514         int uninitialized_var(err);
 515         struct net *net = sock_net(sk);
 516         struct ipv6_pinfo *np = inet6_sk(sk);
 517         struct in6_flowlabel_req freq;
 518         struct ipv6_fl_socklist *sfl1 = NULL;
 519         struct ipv6_fl_socklist *sfl;
 520         struct ipv6_fl_socklist __rcu **sflp;
 521         struct ip6_flowlabel *fl, *fl1 = NULL;
 522
 523
 524         if (optlen < sizeof(freq))
 525                 return -EINVAL;
 526
 527         if (copy_from_user(&freq, optval, sizeof(freq)))
 528                 return -EFAULT;
 529
 530         switch (freq.flr_action) {
 531         case IPV6_FL_A_PUT:
 532                 if (freq.flr_flags & IPV6_FL_F_REFLECT) {
 533                         if (sk->sk_protocol != IPPROTO_TCP)
 534                                 return -ENOPROTOOPT;
 535                         if (!np->repflow)
 536                                 return -ESRCH;
 537                         np->flow_label = 0;
 538                         np->repflow = 0;
 539                         return 0;
 540                 }
 541                 spin_lock_bh(&ip6_sk_fl_lock);
 542                 for (sflp = &np->ipv6_fl_list;
 543                      (sfl = rcu_dereference_protected(*sflp,
 544                                                       lockdep_is_held(&ip6_sk_fl_lock))) != NULL;
 545                      sflp = &sfl->next) {
 546                         if (sfl->fl->label == freq.flr_label) {
 547                                 if (freq.flr_label == (np->flow_label&IPV6_FLOWLABEL_MASK))
 548                                         np->flow_label &= ~IPV6_FLOWLABEL_MASK;
 549                                 *sflp = sfl->next;
 550                                 spin_unlock_bh(&ip6_sk_fl_lock);
 551                                 fl_release(sfl->fl);
 552                                 kfree_rcu(sfl, rcu);
 553                                 return 0;
 554                         }
 555                 }
 556                 spin_unlock_bh(&ip6_sk_fl_lock);
 557                 return -ESRCH;
 558
 559         case IPV6_FL_A_RENEW:
 560                 rcu_read_lock_bh();
 561                 for_each_sk_fl_rcu(np, sfl) {
 562                         if (sfl->fl->label == freq.flr_label) {
 563                                 err = fl6_renew(sfl->fl, freq.flr_linger, freq.flr_expires);
 564                                 rcu_read_unlock_bh();
 565                                 return err;
 566                         }
 567                 }
 568                 rcu_read_unlock_bh();
 569
 570                 if (freq.flr_share == IPV6_FL_S_NONE &&
 571                     ns_capable(net->user_ns, CAP_NET_ADMIN)) {
 572                         fl = fl_lookup(net, freq.flr_label);
 573                         if (fl) {
 574                                 err = fl6_renew(fl, freq.flr_linger, freq.flr_expires);
 575                                 fl_release(fl);
 576                                 return err;
 577                         }
 578                 }
 579                 return -ESRCH;
 580
 581         case IPV6_FL_A_GET:
 582                 if (freq.flr_flags & IPV6_FL_F_REFLECT) {
 583                         struct net *net = sock_net(sk);
 584                         if (net->ipv6.sysctl.flowlabel_consistency) {
 585                                 net_info_ratelimited("Can not set IPV6_FL_F_REFLECT if flowlabel_consistency sysctl is enable\n");
 586                                 return -EPERM;
 587                         }
 588
 589                         if (sk->sk_protocol != IPPROTO_TCP)
 590                                 return -ENOPROTOOPT;
 591
 592                         np->repflow = 1;
 593                         return 0;
 594                 }
 595
 596                 if (freq.flr_label & ~IPV6_FLOWLABEL_MASK)
 597                         return -EINVAL;
 598
 599                 if (net->ipv6.sysctl.flowlabel_state_ranges &&
 600                     (freq.flr_label & IPV6_FLOWLABEL_STATELESS_FLAG))
 601                         return -ERANGE;
 602
 603                 fl = fl_create(net, sk, &freq, optval, optlen, &err);
 604                 if (!fl)
 605                         return err;
 606                 sfl1 = kmalloc(sizeof(*sfl1), GFP_KERNEL);
 607
 608                 if (freq.flr_label) {
 609                         err = -EEXIST;
 610                         rcu_read_lock_bh();
 611                         for_each_sk_fl_rcu(np, sfl) {
 612                                 if (sfl->fl->label == freq.flr_label) {
 613                                         if (freq.flr_flags&IPV6_FL_F_EXCL) {
 614                                                 rcu_read_unlock_bh();
 615                                                 goto done;
 616                                         }
 617                                         fl1 = sfl->fl;
 618                                         atomic_inc(&fl1->users);
 619                                         break;
 620                                 }
 621                         }
 622                         rcu_read_unlock_bh();
 623
 624                         if (!fl1)
 625                                 fl1 = fl_lookup(net, freq.flr_label);
 626                         if (fl1) {
 627 recheck:
 628                                 err = -EEXIST;
 629                                 if (freq.flr_flags&IPV6_FL_F_EXCL)
 630                                         goto release;
 631                                 err = -EPERM;
 632                                 if (fl1->share == IPV6_FL_S_EXCL ||
 633                                     fl1->share != fl->share ||
 634                                     ((fl1->share == IPV6_FL_S_PROCESS) &&
 635                                      (fl1->owner.pid == fl->owner.pid)) ||
 636                                     ((fl1->share == IPV6_FL_S_USER) &&
 637                                      uid_eq(fl1->owner.uid, fl->owner.uid)))
 638                                         goto release;
 639
 640                                 err = -ENOMEM;
 641                                 if (!sfl1)
 642                                         goto release;
 643                                 if (fl->linger > fl1->linger)
 644                                         fl1->linger = fl->linger;
 645                                 if ((long)(fl->expires - fl1->expires) > 0)
 646                                         fl1->expires = fl->expires;
 647                                 fl_link(np, sfl1, fl1);
 648                                 fl_free(fl);
 649                                 return 0;
 650
 651 release:
 652                                 fl_release(fl1);
 653                                 goto done;
 654                         }
 655                 }
 656                 err = -ENOENT;
 657                 if (!(freq.flr_flags&IPV6_FL_F_CREATE))
 658                         goto done;
 659
 660                 err = -ENOMEM;
 661                 if (!sfl1)
 662                         goto done;
 663
 664                 err = mem_check(sk);
 665                 if (err != 0)
 666                         goto done;
 667
 668                 fl1 = fl_intern(net, fl, freq.flr_label);
 669                 if (fl1)
 670                         goto recheck;
 671
 672                 if (!freq.flr_label) {
 673                         if (copy_to_user(&((struct in6_flowlabel_req __user *) optval)->flr_label,
 674                                          &fl->label, sizeof(fl->label))) {
 675                                 /* Intentionally ignore fault. */
 676                         }
 677                 }
 678
 679                 fl_link(np, sfl1, fl);
 680                 return 0;
 681
 682         default:
 683                 return -EINVAL;
 684         }
 685
 686 done:
 687         fl_free(fl);
 688         kfree(sfl1);
 689         return err;
 690 }
 691
 692 #ifdef CONFIG_PROC_FS
 693
 694 struct ip6fl_iter_state {
 695         struct seq_net_private p;
 696         struct pid_namespace *pid_ns;
 697         int bucket;
 698 };
 699
 700 #define ip6fl_seq_private(seq)  ((struct ip6fl_iter_state *)(seq)->private)
 701
 702 static struct ip6_flowlabel *ip6fl_get_first(struct seq_file *seq)
 703 {
 704         struct ip6_flowlabel *fl = NULL;
 705         struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 706         struct net *net = seq_file_net(seq);
 707
 708         for (state->bucket = 0; state->bucket <= FL_HASH_MASK; ++state->bucket) {
 709                 for_each_fl_rcu(state->bucket, fl) {
 710                         if (net_eq(fl->fl_net, net))
 711                                 goto out;
 712                 }
 713         }
 714         fl = NULL;
 715 out:
 716         return fl;
 717 }
 718
 719 static struct ip6_flowlabel *ip6fl_get_next(struct seq_file *seq, struct ip6_flowlabel *fl)
 720 {
 721         struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 722         struct net *net = seq_file_net(seq);
 723
 724         for_each_fl_continue_rcu(fl) {
 725                 if (net_eq(fl->fl_net, net))
 726                         goto out;
 727         }
 728
 729 try_again:
 730         if (++state->bucket <= FL_HASH_MASK) {
 731                 for_each_fl_rcu(state->bucket, fl) {
 732                         if (net_eq(fl->fl_net, net))
 733                                 goto out;
 734                 }
 735                 goto try_again;
 736         }
 737         fl = NULL;
 738
 739 out:
 740         return fl;
 741 }
 742
 743 static struct ip6_flowlabel *ip6fl_get_idx(struct seq_file *seq, loff_t pos)
 744 {
 745         struct ip6_flowlabel *fl = ip6fl_get_first(seq);
 746         if (fl)
 747                 while (pos && (fl = ip6fl_get_next(seq, fl)) != NULL)
 748                         --pos;
 749         return pos ? NULL : fl;
 750 }
 751
 752 static void *ip6fl_seq_start(struct seq_file *seq, loff_t *pos)
 753         __acquires(RCU)
 754 {
 755         rcu_read_lock_bh();
 756         return *pos ? ip6fl_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
 757 }
 758
 759 static void *ip6fl_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 760 {
 761         struct ip6_flowlabel *fl;
 762
 763         if (v == SEQ_START_TOKEN)
 764                 fl = ip6fl_get_first(seq);
 765         else
 766                 fl = ip6fl_get_next(seq, v);
 767         ++*pos;
 768         return fl;
 769 }
 770
 771 static void ip6fl_seq_stop(struct seq_file *seq, void *v)
 772         __releases(RCU)
 773 {
 774         rcu_read_unlock_bh();
 775 }
 776
 777 static int ip6fl_seq_show(struct seq_file *seq, void *v)
 778 {
 779         struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 780         if (v == SEQ_START_TOKEN) {
 781                 seq_puts(seq, "Label S Owner  Users  Linger Expires  Dst                              Opt\n");
 782         } else {
 783                 struct ip6_flowlabel *fl = v;
 784                 seq_printf(seq,
 785                            "%05X %-1d %-6d %-6d %-6ld %-8ld %pi6 %-4d\n",
 786                            (unsigned int)ntohl(fl->label),
 787                            fl->share,
 788                            ((fl->share == IPV6_FL_S_PROCESS) ?
 789                             pid_nr_ns(fl->owner.pid, state->pid_ns) :
 790                             ((fl->share == IPV6_FL_S_USER) ?
 791                              from_kuid_munged(seq_user_ns(seq), fl->owner.uid) :
 792                              0)),
 793                            atomic_read(&fl->users),
 794                            fl->linger/HZ,
 795                            (long)(fl->expires - jiffies)/HZ,
 796                            &fl->dst,
 797                            fl->opt ? fl->opt->opt_nflen : 0);
 798         }
 799         return 0;
 800 }
 801
 802 static const struct seq_operations ip6fl_seq_ops = {
 803         .start  =       ip6fl_seq_start,
 804         .next   =       ip6fl_seq_next,
 805         .stop   =       ip6fl_seq_stop,
 806         .show   =       ip6fl_seq_show,
 807 };
 808
 809 static int ip6fl_seq_open(struct inode *inode, struct file *file)
 810 {
 811         struct seq_file *seq;
 812         struct ip6fl_iter_state *state;
 813         int err;
 814
 815         err = seq_open_net(inode, file, &ip6fl_seq_ops,
 816                            sizeof(struct ip6fl_iter_state));
 817
 818         if (!err) {
 819                 seq = file->private_data;
 820                 state = ip6fl_seq_private(seq);
 821                 rcu_read_lock();
 822                 state->pid_ns = get_pid_ns(task_active_pid_ns(current));
 823                 rcu_read_unlock();
 824         }
 825         return err;
 826 }
 827
 828 static int ip6fl_seq_release(struct inode *inode, struct file *file)
 829 {
 830         struct seq_file *seq = file->private_data;
 831         struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 832         put_pid_ns(state->pid_ns);
 833         return seq_release_net(inode, file);
 834 }
 835
 836 static const struct file_operations ip6fl_seq_fops = {
 837         .owner          =       THIS_MODULE,
 838         .open           =       ip6fl_seq_open,
 839         .read           =       seq_read,
 840         .llseek         =       seq_lseek,
 841         .release        =       ip6fl_seq_release,
 842 };
 843
 844 static int __net_init ip6_flowlabel_proc_init(struct net *net)
 845 {
 846         if (!proc_create("ip6_flowlabel", S_IRUGO, net->proc_net,
 847                          &ip6fl_seq_fops))
 848                 return -ENOMEM;
 849         return 0;
 850 }
 851
 852 static void __net_exit ip6_flowlabel_proc_fini(struct net *net)
 853 {
 854         remove_proc_entry("ip6_flowlabel", net->proc_net);
 855 }
 856 #else
 857 static inline int ip6_flowlabel_proc_init(struct net *net)
 858 {
 859         return 0;
 860 }
 861 static inline void ip6_flowlabel_proc_fini(struct net *net)
 862 {
 863 }
 864 #endif
 865
 866 static void __net_exit ip6_flowlabel_net_exit(struct net *net)
 867 {
 868         ip6_fl_purge(net);
 869         ip6_flowlabel_proc_fini(net);
 870 }
 871
 872 static struct pernet_operations ip6_flowlabel_net_ops = {
 873         .init = ip6_flowlabel_proc_init,
 874         .exit = ip6_flowlabel_net_exit,
 875 };
 876
 877 int ip6_flowlabel_init(void)
 878 {
 879         return register_pernet_subsys(&ip6_flowlabel_net_ops);
 880 }
 881
 882 void ip6_flowlabel_cleanup(void)
 883 {
 884         del_timer(&ip6_fl_gc_timer);
 885         unregister_pernet_subsys(&ip6_flowlabel_net_ops);
 886 }