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                 release_net(fl->fl_net);
 104                 kfree(fl->opt);
 105                 kfree_rcu(fl, rcu);
 106         }
 107 }
 108
 109 static void fl_release(struct ip6_flowlabel *fl)
 110 {
 111         spin_lock_bh(&ip6_fl_lock);
 112
 113         fl->lastuse = jiffies;
 114         if (atomic_dec_and_test(&fl->users)) {
 115                 unsigned long ttd = fl->lastuse + fl->linger;
 116                 if (time_after(ttd, fl->expires))
 117                         fl->expires = ttd;
 118                 ttd = fl->expires;
 119                 if (fl->opt && fl->share == IPV6_FL_S_EXCL) {
 120                         struct ipv6_txoptions *opt = fl->opt;
 121                         fl->opt = NULL;
 122                         kfree(opt);
 123                 }
 124                 if (!timer_pending(&ip6_fl_gc_timer) ||
 125                     time_after(ip6_fl_gc_timer.expires, ttd))
 126                         mod_timer(&ip6_fl_gc_timer, ttd);
 127         }
 128         spin_unlock_bh(&ip6_fl_lock);
 129 }
 130
 131 static void ip6_fl_gc(unsigned long dummy)
 132 {
 133         int i;
 134         unsigned long now = jiffies;
 135         unsigned long sched = 0;
 136
 137         spin_lock(&ip6_fl_lock);
 138
 139         for (i = 0; i <= FL_HASH_MASK; i++) {
 140                 struct ip6_flowlabel *fl;
 141                 struct ip6_flowlabel __rcu **flp;
 142
 143                 flp = &fl_ht[i];
 144                 while ((fl = rcu_dereference_protected(*flp,
 145                                                        lockdep_is_held(&ip6_fl_lock))) != NULL) {
 146                         if (atomic_read(&fl->users) == 0) {
 147                                 unsigned long ttd = fl->lastuse + fl->linger;
 148                                 if (time_after(ttd, fl->expires))
 149                                         fl->expires = ttd;
 150                                 ttd = fl->expires;
 151                                 if (time_after_eq(now, ttd)) {
 152                                         *flp = fl->next;
 153                                         fl_free(fl);
 154                                         atomic_dec(&fl_size);
 155                                         continue;
 156                                 }
 157                                 if (!sched || time_before(ttd, sched))
 158                                         sched = ttd;
 159                         }
 160                         flp = &fl->next;
 161                 }
 162         }
 163         if (!sched && atomic_read(&fl_size))
 164                 sched = now + FL_MAX_LINGER;
 165         if (sched) {
 166                 mod_timer(&ip6_fl_gc_timer, sched);
 167         }
 168         spin_unlock(&ip6_fl_lock);
 169 }
 170
 171 static void __net_exit ip6_fl_purge(struct net *net)
 172 {
 173         int i;
 174
 175         spin_lock(&ip6_fl_lock);
 176         for (i = 0; i <= FL_HASH_MASK; i++) {
 177                 struct ip6_flowlabel *fl;
 178                 struct ip6_flowlabel __rcu **flp;
 179
 180                 flp = &fl_ht[i];
 181                 while ((fl = rcu_dereference_protected(*flp,
 182                                                        lockdep_is_held(&ip6_fl_lock))) != NULL) {
 183                         if (net_eq(fl->fl_net, net) &&
 184                             atomic_read(&fl->users) == 0) {
 185                                 *flp = fl->next;
 186                                 fl_free(fl);
 187                                 atomic_dec(&fl_size);
 188                                 continue;
 189                         }
 190                         flp = &fl->next;
 191                 }
 192         }
 193         spin_unlock(&ip6_fl_lock);
 194 }
 195
 196 static struct ip6_flowlabel *fl_intern(struct net *net,
 197                                        struct ip6_flowlabel *fl, __be32 label)
 198 {
 199         struct ip6_flowlabel *lfl;
 200
 201         fl->label = label & IPV6_FLOWLABEL_MASK;
 202
 203         spin_lock_bh(&ip6_fl_lock);
 204         if (label == 0) {
 205                 for (;;) {
 206                         fl->label = htonl(prandom_u32())&IPV6_FLOWLABEL_MASK;
 207                         if (fl->label) {
 208                                 lfl = __fl_lookup(net, fl->label);
 209                                 if (lfl == NULL)
 210                                         break;
 211                         }
 212                 }
 213         } else {
 214                 /*
 215                  * we dropper the ip6_fl_lock, so this entry could reappear
 216                  * and we need to recheck with it.
 217                  *
 218                  * OTOH no need to search the active socket first, like it is
 219                  * done in ipv6_flowlabel_opt - sock is locked, so new entry
 220                  * with the same label can only appear on another sock
 221                  */
 222                 lfl = __fl_lookup(net, fl->label);
 223                 if (lfl != NULL) {
 224                         atomic_inc(&lfl->users);
 225                         spin_unlock_bh(&ip6_fl_lock);
 226                         return lfl;
 227                 }
 228         }
 229
 230         fl->lastuse = jiffies;
 231         fl->next = fl_ht[FL_HASH(fl->label)];
 232         rcu_assign_pointer(fl_ht[FL_HASH(fl->label)], fl);
 233         atomic_inc(&fl_size);
 234         spin_unlock_bh(&ip6_fl_lock);
 235         return NULL;
 236 }
 237
 238
 239
 240 /* Socket flowlabel lists */
 241
 242 struct ip6_flowlabel *fl6_sock_lookup(struct sock *sk, __be32 label)
 243 {
 244         struct ipv6_fl_socklist *sfl;
 245         struct ipv6_pinfo *np = inet6_sk(sk);
 246
 247         label &= IPV6_FLOWLABEL_MASK;
 248
 249         rcu_read_lock_bh();
 250         for_each_sk_fl_rcu(np, sfl) {
 251                 struct ip6_flowlabel *fl = sfl->fl;
 252                 if (fl->label == label) {
 253                         fl->lastuse = jiffies;
 254                         atomic_inc(&fl->users);
 255                         rcu_read_unlock_bh();
 256                         return fl;
 257                 }
 258         }
 259         rcu_read_unlock_bh();
 260         return NULL;
 261 }
 262 EXPORT_SYMBOL_GPL(fl6_sock_lookup);
 263
 264 void fl6_free_socklist(struct sock *sk)
 265 {
 266         struct ipv6_pinfo *np = inet6_sk(sk);
 267         struct ipv6_fl_socklist *sfl;
 268
 269         if (!rcu_access_pointer(np->ipv6_fl_list))
 270                 return;
 271
 272         spin_lock_bh(&ip6_sk_fl_lock);
 273         while ((sfl = rcu_dereference_protected(np->ipv6_fl_list,
 274                                                 lockdep_is_held(&ip6_sk_fl_lock))) != NULL) {
 275                 np->ipv6_fl_list = sfl->next;
 276                 spin_unlock_bh(&ip6_sk_fl_lock);
 277
 278                 fl_release(sfl->fl);
 279                 kfree_rcu(sfl, rcu);
 280
 281                 spin_lock_bh(&ip6_sk_fl_lock);
 282         }
 283         spin_unlock_bh(&ip6_sk_fl_lock);
 284 }
 285
 286 /* Service routines */
 287
 288
 289 /*
 290    It is the only difficult place. flowlabel enforces equal headers
 291    before and including routing header, however user may supply options
 292    following rthdr.
 293  */
 294
 295 struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions *opt_space,
 296                                          struct ip6_flowlabel *fl,
 297                                          struct ipv6_txoptions *fopt)
 298 {
 299         struct ipv6_txoptions *fl_opt = fl->opt;
 300
 301         if (fopt == NULL || fopt->opt_flen == 0)
 302                 return fl_opt;
 303
 304         if (fl_opt != NULL) {
 305                 opt_space->hopopt = fl_opt->hopopt;
 306                 opt_space->dst0opt = fl_opt->dst0opt;
 307                 opt_space->srcrt = fl_opt->srcrt;
 308                 opt_space->opt_nflen = fl_opt->opt_nflen;
 309         } else {
 310                 if (fopt->opt_nflen == 0)
 311                         return fopt;
 312                 opt_space->hopopt = NULL;
 313                 opt_space->dst0opt = NULL;
 314                 opt_space->srcrt = NULL;
 315                 opt_space->opt_nflen = 0;
 316         }
 317         opt_space->dst1opt = fopt->dst1opt;
 318         opt_space->opt_flen = fopt->opt_flen;
 319         return opt_space;
 320 }
 321 EXPORT_SYMBOL_GPL(fl6_merge_options);
 322
 323 static unsigned long check_linger(unsigned long ttl)
 324 {
 325         if (ttl < FL_MIN_LINGER)
 326                 return FL_MIN_LINGER*HZ;
 327         if (ttl > FL_MAX_LINGER && !capable(CAP_NET_ADMIN))
 328                 return 0;
 329         return ttl*HZ;
 330 }
 331
 332 static int fl6_renew(struct ip6_flowlabel *fl, unsigned long linger, unsigned long expires)
 333 {
 334         linger = check_linger(linger);
 335         if (!linger)
 336                 return -EPERM;
 337         expires = check_linger(expires);
 338         if (!expires)
 339                 return -EPERM;
 340
 341         spin_lock_bh(&ip6_fl_lock);
 342         fl->lastuse = jiffies;
 343         if (time_before(fl->linger, linger))
 344                 fl->linger = linger;
 345         if (time_before(expires, fl->linger))
 346                 expires = fl->linger;
 347         if (time_before(fl->expires, fl->lastuse + expires))
 348                 fl->expires = fl->lastuse + expires;
 349         spin_unlock_bh(&ip6_fl_lock);
 350
 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         rcu_read_lock_bh();
 453         for_each_sk_fl_rcu(np, sfl)
 454                 count++;
 455         rcu_read_unlock_bh();
 456
 457         if (room <= 0 ||
 458             ((count >= FL_MAX_PER_SOCK ||
 459               (count > 0 && room < FL_MAX_SIZE/2) || room < FL_MAX_SIZE/4) &&
 460              !capable(CAP_NET_ADMIN)))
 461                 return -ENOBUFS;
 462
 463         return 0;
 464 }
 465
 466 static inline void fl_link(struct ipv6_pinfo *np, struct ipv6_fl_socklist *sfl,
 467                 struct ip6_flowlabel *fl)
 468 {
 469         spin_lock_bh(&ip6_sk_fl_lock);
 470         sfl->fl = fl;
 471         sfl->next = np->ipv6_fl_list;
 472         rcu_assign_pointer(np->ipv6_fl_list, sfl);
 473         spin_unlock_bh(&ip6_sk_fl_lock);
 474 }
 475
 476 int ipv6_flowlabel_opt_get(struct sock *sk, struct in6_flowlabel_req *freq,
 477                            int flags)
 478 {
 479         struct ipv6_pinfo *np = inet6_sk(sk);
 480         struct ipv6_fl_socklist *sfl;
 481
 482         if (flags & IPV6_FL_F_REMOTE) {
 483                 freq->flr_label = np->rcv_flowinfo & IPV6_FLOWLABEL_MASK;
 484                 return 0;
 485         }
 486
 487         if (np->repflow) {
 488                 freq->flr_label = np->flow_label;
 489                 return 0;
 490         }
 491
 492         rcu_read_lock_bh();
 493
 494         for_each_sk_fl_rcu(np, sfl) {
 495                 if (sfl->fl->label == (np->flow_label & IPV6_FLOWLABEL_MASK)) {
 496                         spin_lock_bh(&ip6_fl_lock);
 497                         freq->flr_label = sfl->fl->label;
 498                         freq->flr_dst = sfl->fl->dst;
 499                         freq->flr_share = sfl->fl->share;
 500                         freq->flr_expires = (sfl->fl->expires - jiffies) / HZ;
 501                         freq->flr_linger = sfl->fl->linger / HZ;
 502
 503                         spin_unlock_bh(&ip6_fl_lock);
 504                         rcu_read_unlock_bh();
 505                         return 0;
 506                 }
 507         }
 508         rcu_read_unlock_bh();
 509
 510         return -ENOENT;
 511 }
 512
 513 int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen)
 514 {
 515         int uninitialized_var(err);
 516         struct net *net = sock_net(sk);
 517         struct ipv6_pinfo *np = inet6_sk(sk);
 518         struct in6_flowlabel_req freq;
 519         struct ipv6_fl_socklist *sfl1 = NULL;
 520         struct ipv6_fl_socklist *sfl;
 521         struct ipv6_fl_socklist __rcu **sflp;
 522         struct ip6_flowlabel *fl, *fl1 = NULL;
 523
 524
 525         if (optlen < sizeof(freq))
 526                 return -EINVAL;
 527
 528         if (copy_from_user(&freq, optval, sizeof(freq)))
 529                 return -EFAULT;
 530
 531         switch (freq.flr_action) {
 532         case IPV6_FL_A_PUT:
 533                 if (freq.flr_flags & IPV6_FL_F_REFLECT) {
 534                         if (sk->sk_protocol != IPPROTO_TCP)
 535                                 return -ENOPROTOOPT;
 536                         if (!np->repflow)
 537                                 return -ESRCH;
 538                         np->flow_label = 0;
 539                         np->repflow = 0;
 540                         return 0;
 541                 }
 542                 spin_lock_bh(&ip6_sk_fl_lock);
 543                 for (sflp = &np->ipv6_fl_list;
 544                      (sfl = rcu_dereference(*sflp)) != 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 = rcu_dereference(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                 fl = fl_create(net, sk, &freq, optval, optlen, &err);
 600                 if (fl == NULL)
 601                         return err;
 602                 sfl1 = kmalloc(sizeof(*sfl1), GFP_KERNEL);
 603
 604                 if (freq.flr_label) {
 605                         err = -EEXIST;
 606                         rcu_read_lock_bh();
 607                         for_each_sk_fl_rcu(np, sfl) {
 608                                 if (sfl->fl->label == freq.flr_label) {
 609                                         if (freq.flr_flags&IPV6_FL_F_EXCL) {
 610                                                 rcu_read_unlock_bh();
 611                                                 goto done;
 612                                         }
 613                                         fl1 = sfl->fl;
 614                                         atomic_inc(&fl1->users);
 615                                         break;
 616                                 }
 617                         }
 618                         rcu_read_unlock_bh();
 619
 620                         if (fl1 == NULL)
 621                                 fl1 = fl_lookup(net, freq.flr_label);
 622                         if (fl1) {
 623 recheck:
 624                                 err = -EEXIST;
 625                                 if (freq.flr_flags&IPV6_FL_F_EXCL)
 626                                         goto release;
 627                                 err = -EPERM;
 628                                 if (fl1->share == IPV6_FL_S_EXCL ||
 629                                     fl1->share != fl->share ||
 630                                     ((fl1->share == IPV6_FL_S_PROCESS) &&
 631                                      (fl1->owner.pid == fl->owner.pid)) ||
 632                                     ((fl1->share == IPV6_FL_S_USER) &&
 633                                      uid_eq(fl1->owner.uid, fl->owner.uid)))
 634                                         goto release;
 635
 636                                 err = -ENOMEM;
 637                                 if (sfl1 == NULL)
 638                                         goto release;
 639                                 if (fl->linger > fl1->linger)
 640                                         fl1->linger = fl->linger;
 641                                 if ((long)(fl->expires - fl1->expires) > 0)
 642                                         fl1->expires = fl->expires;
 643                                 fl_link(np, sfl1, fl1);
 644                                 fl_free(fl);
 645                                 return 0;
 646
 647 release:
 648                                 fl_release(fl1);
 649                                 goto done;
 650                         }
 651                 }
 652                 err = -ENOENT;
 653                 if (!(freq.flr_flags&IPV6_FL_F_CREATE))
 654                         goto done;
 655
 656                 err = -ENOMEM;
 657                 if (sfl1 == NULL)
 658                         goto done;
 659
 660                 err = mem_check(sk);
 661                 if (err != 0)
 662                         goto done;
 663
 664                 fl1 = fl_intern(net, fl, freq.flr_label);
 665                 if (fl1 != NULL)
 666                         goto recheck;
 667
 668                 if (!freq.flr_label) {
 669                         if (copy_to_user(&((struct in6_flowlabel_req __user *) optval)->flr_label,
 670                                          &fl->label, sizeof(fl->label))) {
 671                                 /* Intentionally ignore fault. */
 672                         }
 673                 }
 674
 675                 fl_link(np, sfl1, fl);
 676                 return 0;
 677
 678         default:
 679                 return -EINVAL;
 680         }
 681
 682 done:
 683         fl_free(fl);
 684         kfree(sfl1);
 685         return err;
 686 }
 687
 688 #ifdef CONFIG_PROC_FS
 689
 690 struct ip6fl_iter_state {
 691         struct seq_net_private p;
 692         struct pid_namespace *pid_ns;
 693         int bucket;
 694 };
 695
 696 #define ip6fl_seq_private(seq)  ((struct ip6fl_iter_state *)(seq)->private)
 697
 698 static struct ip6_flowlabel *ip6fl_get_first(struct seq_file *seq)
 699 {
 700         struct ip6_flowlabel *fl = NULL;
 701         struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 702         struct net *net = seq_file_net(seq);
 703
 704         for (state->bucket = 0; state->bucket <= FL_HASH_MASK; ++state->bucket) {
 705                 for_each_fl_rcu(state->bucket, fl) {
 706                         if (net_eq(fl->fl_net, net))
 707                                 goto out;
 708                 }
 709         }
 710         fl = NULL;
 711 out:
 712         return fl;
 713 }
 714
 715 static struct ip6_flowlabel *ip6fl_get_next(struct seq_file *seq, struct ip6_flowlabel *fl)
 716 {
 717         struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 718         struct net *net = seq_file_net(seq);
 719
 720         for_each_fl_continue_rcu(fl) {
 721                 if (net_eq(fl->fl_net, net))
 722                         goto out;
 723         }
 724
 725 try_again:
 726         if (++state->bucket <= FL_HASH_MASK) {
 727                 for_each_fl_rcu(state->bucket, fl) {
 728                         if (net_eq(fl->fl_net, net))
 729                                 goto out;
 730                 }
 731                 goto try_again;
 732         }
 733         fl = NULL;
 734
 735 out:
 736         return fl;
 737 }
 738
 739 static struct ip6_flowlabel *ip6fl_get_idx(struct seq_file *seq, loff_t pos)
 740 {
 741         struct ip6_flowlabel *fl = ip6fl_get_first(seq);
 742         if (fl)
 743                 while (pos && (fl = ip6fl_get_next(seq, fl)) != NULL)
 744                         --pos;
 745         return pos ? NULL : fl;
 746 }
 747
 748 static void *ip6fl_seq_start(struct seq_file *seq, loff_t *pos)
 749         __acquires(RCU)
 750 {
 751         rcu_read_lock_bh();
 752         return *pos ? ip6fl_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
 753 }
 754
 755 static void *ip6fl_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 756 {
 757         struct ip6_flowlabel *fl;
 758
 759         if (v == SEQ_START_TOKEN)
 760                 fl = ip6fl_get_first(seq);
 761         else
 762                 fl = ip6fl_get_next(seq, v);
 763         ++*pos;
 764         return fl;
 765 }
 766
 767 static void ip6fl_seq_stop(struct seq_file *seq, void *v)
 768         __releases(RCU)
 769 {
 770         rcu_read_unlock_bh();
 771 }
 772
 773 static int ip6fl_seq_show(struct seq_file *seq, void *v)
 774 {
 775         struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 776         if (v == SEQ_START_TOKEN) {
 777                 seq_puts(seq, "Label S Owner  Users  Linger Expires  Dst                              Opt\n");
 778         } else {
 779                 struct ip6_flowlabel *fl = v;
 780                 seq_printf(seq,
 781                            "%05X %-1d %-6d %-6d %-6ld %-8ld %pi6 %-4d\n",
 782                            (unsigned int)ntohl(fl->label),
 783                            fl->share,
 784                            ((fl->share == IPV6_FL_S_PROCESS) ?
 785                             pid_nr_ns(fl->owner.pid, state->pid_ns) :
 786                             ((fl->share == IPV6_FL_S_USER) ?
 787                              from_kuid_munged(seq_user_ns(seq), fl->owner.uid) :
 788                              0)),
 789                            atomic_read(&fl->users),
 790                            fl->linger/HZ,
 791                            (long)(fl->expires - jiffies)/HZ,
 792                            &fl->dst,
 793                            fl->opt ? fl->opt->opt_nflen : 0);
 794         }
 795         return 0;
 796 }
 797
 798 static const struct seq_operations ip6fl_seq_ops = {
 799         .start  =       ip6fl_seq_start,
 800         .next   =       ip6fl_seq_next,
 801         .stop   =       ip6fl_seq_stop,
 802         .show   =       ip6fl_seq_show,
 803 };
 804
 805 static int ip6fl_seq_open(struct inode *inode, struct file *file)
 806 {
 807         struct seq_file *seq;
 808         struct ip6fl_iter_state *state;
 809         int err;
 810
 811         err = seq_open_net(inode, file, &ip6fl_seq_ops,
 812                            sizeof(struct ip6fl_iter_state));
 813
 814         if (!err) {
 815                 seq = file->private_data;
 816                 state = ip6fl_seq_private(seq);
 817                 rcu_read_lock();
 818                 state->pid_ns = get_pid_ns(task_active_pid_ns(current));
 819                 rcu_read_unlock();
 820         }
 821         return err;
 822 }
 823
 824 static int ip6fl_seq_release(struct inode *inode, struct file *file)
 825 {
 826         struct seq_file *seq = file->private_data;
 827         struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 828         put_pid_ns(state->pid_ns);
 829         return seq_release_net(inode, file);
 830 }
 831
 832 static const struct file_operations ip6fl_seq_fops = {
 833         .owner          =       THIS_MODULE,
 834         .open           =       ip6fl_seq_open,
 835         .read           =       seq_read,
 836         .llseek         =       seq_lseek,
 837         .release        =       ip6fl_seq_release,
 838 };
 839
 840 static int __net_init ip6_flowlabel_proc_init(struct net *net)
 841 {
 842         if (!proc_create("ip6_flowlabel", S_IRUGO, net->proc_net,
 843                          &ip6fl_seq_fops))
 844                 return -ENOMEM;
 845         return 0;
 846 }
 847
 848 static void __net_exit ip6_flowlabel_proc_fini(struct net *net)
 849 {
 850         remove_proc_entry("ip6_flowlabel", net->proc_net);
 851 }
 852 #else
 853 static inline int ip6_flowlabel_proc_init(struct net *net)
 854 {
 855         return 0;
 856 }
 857 static inline void ip6_flowlabel_proc_fini(struct net *net)
 858 {
 859 }
 860 #endif
 861
 862 static void __net_exit ip6_flowlabel_net_exit(struct net *net)
 863 {
 864         ip6_fl_purge(net);
 865         ip6_flowlabel_proc_fini(net);
 866 }
 867
 868 static struct pernet_operations ip6_flowlabel_net_ops = {
 869         .init = ip6_flowlabel_proc_init,
 870         .exit = ip6_flowlabel_net_exit,
 871 };
 872
 873 int ip6_flowlabel_init(void)
 874 {
 875         return register_pernet_subsys(&ip6_flowlabel_net_ops);
 876 }
 877
 878 void ip6_flowlabel_cleanup(void)
 879 {
 880         del_timer(&ip6_fl_gc_timer);
 881         unregister_pernet_subsys(&ip6_flowlabel_net_ops);
 882 }