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   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
  24 #include <net/net_namespace.h>
  25 #include <net/sock.h>
  26
  27 #include <net/ipv6.h>
  28 #include <net/ndisc.h>
  29 #include <net/protocol.h>
  30 #include <net/ip6_route.h>
  31 #include <net/addrconf.h>
  32 #include <net/rawv6.h>
  33 #include <net/icmp.h>
  34 #include <net/transp_v6.h>
  35
  36 #include <asm/uaccess.h>
  37
  38 #define FL_MIN_LINGER   6       /* Minimal linger. It is set to 6sec specified
  39                                    in old IPv6 RFC. Well, it was reasonable value.
  40                                  */
  41 #define FL_MAX_LINGER   60      /* Maximal linger timeout */
  42
  43 /* FL hash table */
  44
  45 #define FL_MAX_PER_SOCK 32
  46 #define FL_MAX_SIZE     4096
  47 #define FL_HASH_MASK    255
  48 #define FL_HASH(l)      (ntohl(l)&FL_HASH_MASK)
  49
  50 static atomic_t fl_size = ATOMIC_INIT(0);
  51 static struct ip6_flowlabel *fl_ht[FL_HASH_MASK+1];
  52
  53 static void ip6_fl_gc(unsigned long dummy);
  54 static DEFINE_TIMER(ip6_fl_gc_timer, ip6_fl_gc, 0, 0);
  55
  56 /* FL hash table lock: it protects only of GC */
  57
  58 static DEFINE_RWLOCK(ip6_fl_lock);
  59
  60 /* Big socket sock */
  61
  62 static DEFINE_RWLOCK(ip6_sk_fl_lock);
  63
  64
  65 static inline struct ip6_flowlabel *__fl_lookup(struct net *net, __be32 label)
  66 {
  67         struct ip6_flowlabel *fl;
  68
  69         for (fl=fl_ht[FL_HASH(label)]; fl; fl = fl->next) {
  70                 if (fl->label == label && fl->fl_net == net)
  71                         return fl;
  72         }
  73         return NULL;
  74 }
  75
  76 static struct ip6_flowlabel *fl_lookup(struct net *net, __be32 label)
  77 {
  78         struct ip6_flowlabel *fl;
  79
  80         read_lock_bh(&ip6_fl_lock);
  81         fl = __fl_lookup(net, label);
  82         if (fl)
  83                 atomic_inc(&fl->users);
  84         read_unlock_bh(&ip6_fl_lock);
  85         return fl;
  86 }
  87
  88
  89 static void fl_free(struct ip6_flowlabel *fl)
  90 {
  91         if (fl) {
  92                 release_net(fl->fl_net);
  93                 kfree(fl->opt);
  94         }
  95         kfree(fl);
  96 }
  97
  98 static void fl_release(struct ip6_flowlabel *fl)
  99 {
 100         write_lock_bh(&ip6_fl_lock);
 101
 102         fl->lastuse = jiffies;
 103         if (atomic_dec_and_test(&fl->users)) {
 104                 unsigned long ttd = fl->lastuse + fl->linger;
 105                 if (time_after(ttd, fl->expires))
 106                         fl->expires = ttd;
 107                 ttd = fl->expires;
 108                 if (fl->opt && fl->share == IPV6_FL_S_EXCL) {
 109                         struct ipv6_txoptions *opt = fl->opt;
 110                         fl->opt = NULL;
 111                         kfree(opt);
 112                 }
 113                 if (!timer_pending(&ip6_fl_gc_timer) ||
 114                     time_after(ip6_fl_gc_timer.expires, ttd))
 115                         mod_timer(&ip6_fl_gc_timer, ttd);
 116         }
 117         write_unlock_bh(&ip6_fl_lock);
 118 }
 119
 120 static void ip6_fl_gc(unsigned long dummy)
 121 {
 122         int i;
 123         unsigned long now = jiffies;
 124         unsigned long sched = 0;
 125
 126         write_lock(&ip6_fl_lock);
 127
 128         for (i=0; i<=FL_HASH_MASK; i++) {
 129                 struct ip6_flowlabel *fl, **flp;
 130                 flp = &fl_ht[i];
 131                 while ((fl=*flp) != NULL) {
 132                         if (atomic_read(&fl->users) == 0) {
 133                                 unsigned long ttd = fl->lastuse + fl->linger;
 134                                 if (time_after(ttd, fl->expires))
 135                                         fl->expires = ttd;
 136                                 ttd = fl->expires;
 137                                 if (time_after_eq(now, ttd)) {
 138                                         *flp = fl->next;
 139                                         fl_free(fl);
 140                                         atomic_dec(&fl_size);
 141                                         continue;
 142                                 }
 143                                 if (!sched || time_before(ttd, sched))
 144                                         sched = ttd;
 145                         }
 146                         flp = &fl->next;
 147                 }
 148         }
 149         if (!sched && atomic_read(&fl_size))
 150                 sched = now + FL_MAX_LINGER;
 151         if (sched) {
 152                 mod_timer(&ip6_fl_gc_timer, sched);
 153         }
 154         write_unlock(&ip6_fl_lock);
 155 }
 156
 157 static void ip6_fl_purge(struct net *net)
 158 {
 159         int i;
 160
 161         write_lock(&ip6_fl_lock);
 162         for (i = 0; i <= FL_HASH_MASK; i++) {
 163                 struct ip6_flowlabel *fl, **flp;
 164                 flp = &fl_ht[i];
 165                 while ((fl = *flp) != NULL) {
 166                         if (fl->fl_net == net && atomic_read(&fl->users) == 0) {
 167                                 *flp = fl->next;
 168                                 fl_free(fl);
 169                                 atomic_dec(&fl_size);
 170                                 continue;
 171                         }
 172                         flp = &fl->next;
 173                 }
 174         }
 175         write_unlock(&ip6_fl_lock);
 176 }
 177
 178 static struct ip6_flowlabel *fl_intern(struct net *net,
 179                                        struct ip6_flowlabel *fl, __be32 label)
 180 {
 181         struct ip6_flowlabel *lfl;
 182
 183         fl->label = label & IPV6_FLOWLABEL_MASK;
 184
 185         write_lock_bh(&ip6_fl_lock);
 186         if (label == 0) {
 187                 for (;;) {
 188                         fl->label = htonl(net_random())&IPV6_FLOWLABEL_MASK;
 189                         if (fl->label) {
 190                                 lfl = __fl_lookup(net, fl->label);
 191                                 if (lfl == NULL)
 192                                         break;
 193                         }
 194                 }
 195         } else {
 196                 /*
 197                  * we dropper the ip6_fl_lock, so this entry could reappear
 198                  * and we need to recheck with it.
 199                  *
 200                  * OTOH no need to search the active socket first, like it is
 201                  * done in ipv6_flowlabel_opt - sock is locked, so new entry
 202                  * with the same label can only appear on another sock
 203                  */
 204                 lfl = __fl_lookup(net, fl->label);
 205                 if (lfl != NULL) {
 206                         atomic_inc(&lfl->users);
 207                         write_unlock_bh(&ip6_fl_lock);
 208                         return lfl;
 209                 }
 210         }
 211
 212         fl->lastuse = jiffies;
 213         fl->next = fl_ht[FL_HASH(fl->label)];
 214         fl_ht[FL_HASH(fl->label)] = fl;
 215         atomic_inc(&fl_size);
 216         write_unlock_bh(&ip6_fl_lock);
 217         return NULL;
 218 }
 219
 220
 221
 222 /* Socket flowlabel lists */
 223
 224 struct ip6_flowlabel * fl6_sock_lookup(struct sock *sk, __be32 label)
 225 {
 226         struct ipv6_fl_socklist *sfl;
 227         struct ipv6_pinfo *np = inet6_sk(sk);
 228
 229         label &= IPV6_FLOWLABEL_MASK;
 230
 231         read_lock_bh(&ip6_sk_fl_lock);
 232         for (sfl=np->ipv6_fl_list; sfl; sfl = sfl->next) {
 233                 struct ip6_flowlabel *fl = sfl->fl;
 234                 if (fl->label == label) {
 235                         fl->lastuse = jiffies;
 236                         atomic_inc(&fl->users);
 237                         read_unlock_bh(&ip6_sk_fl_lock);
 238                         return fl;
 239                 }
 240         }
 241         read_unlock_bh(&ip6_sk_fl_lock);
 242         return NULL;
 243 }
 244
 245 EXPORT_SYMBOL_GPL(fl6_sock_lookup);
 246
 247 void fl6_free_socklist(struct sock *sk)
 248 {
 249         struct ipv6_pinfo *np = inet6_sk(sk);
 250         struct ipv6_fl_socklist *sfl;
 251
 252         while ((sfl = np->ipv6_fl_list) != NULL) {
 253                 np->ipv6_fl_list = sfl->next;
 254                 fl_release(sfl->fl);
 255                 kfree(sfl);
 256         }
 257 }
 258
 259 /* Service routines */
 260
 261
 262 /*
 263    It is the only difficult place. flowlabel enforces equal headers
 264    before and including routing header, however user may supply options
 265    following rthdr.
 266  */
 267
 268 struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions * opt_space,
 269                                          struct ip6_flowlabel * fl,
 270                                          struct ipv6_txoptions * fopt)
 271 {
 272         struct ipv6_txoptions * fl_opt = fl->opt;
 273
 274         if (fopt == NULL || fopt->opt_flen == 0)
 275                 return fl_opt;
 276
 277         if (fl_opt != NULL) {
 278                 opt_space->hopopt = fl_opt->hopopt;
 279                 opt_space->dst0opt = fl_opt->dst0opt;
 280                 opt_space->srcrt = fl_opt->srcrt;
 281                 opt_space->opt_nflen = fl_opt->opt_nflen;
 282         } else {
 283                 if (fopt->opt_nflen == 0)
 284                         return fopt;
 285                 opt_space->hopopt = NULL;
 286                 opt_space->dst0opt = NULL;
 287                 opt_space->srcrt = NULL;
 288                 opt_space->opt_nflen = 0;
 289         }
 290         opt_space->dst1opt = fopt->dst1opt;
 291         opt_space->opt_flen = fopt->opt_flen;
 292         return opt_space;
 293 }
 294
 295 static unsigned long check_linger(unsigned long ttl)
 296 {
 297         if (ttl < FL_MIN_LINGER)
 298                 return FL_MIN_LINGER*HZ;
 299         if (ttl > FL_MAX_LINGER && !capable(CAP_NET_ADMIN))
 300                 return 0;
 301         return ttl*HZ;
 302 }
 303
 304 static int fl6_renew(struct ip6_flowlabel *fl, unsigned long linger, unsigned long expires)
 305 {
 306         linger = check_linger(linger);
 307         if (!linger)
 308                 return -EPERM;
 309         expires = check_linger(expires);
 310         if (!expires)
 311                 return -EPERM;
 312         fl->lastuse = jiffies;
 313         if (time_before(fl->linger, linger))
 314                 fl->linger = linger;
 315         if (time_before(expires, fl->linger))
 316                 expires = fl->linger;
 317         if (time_before(fl->expires, fl->lastuse + expires))
 318                 fl->expires = fl->lastuse + expires;
 319         return 0;
 320 }
 321
 322 static struct ip6_flowlabel *
 323 fl_create(struct net *net, struct in6_flowlabel_req *freq, char __user *optval,
 324           int optlen, int *err_p)
 325 {
 326         struct ip6_flowlabel *fl;
 327         int olen;
 328         int addr_type;
 329         int err;
 330
 331         err = -ENOMEM;
 332         fl = kzalloc(sizeof(*fl), GFP_KERNEL);
 333         if (fl == NULL)
 334                 goto done;
 335
 336         olen = optlen - CMSG_ALIGN(sizeof(*freq));
 337         if (olen > 0) {
 338                 struct msghdr msg;
 339                 struct flowi flowi;
 340                 int junk;
 341
 342                 err = -ENOMEM;
 343                 fl->opt = kmalloc(sizeof(*fl->opt) + olen, GFP_KERNEL);
 344                 if (fl->opt == NULL)
 345                         goto done;
 346
 347                 memset(fl->opt, 0, sizeof(*fl->opt));
 348                 fl->opt->tot_len = sizeof(*fl->opt) + olen;
 349                 err = -EFAULT;
 350                 if (copy_from_user(fl->opt+1, optval+CMSG_ALIGN(sizeof(*freq)), olen))
 351                         goto done;
 352
 353                 msg.msg_controllen = olen;
 354                 msg.msg_control = (void*)(fl->opt+1);
 355                 flowi.oif = 0;
 356
 357                 err = datagram_send_ctl(&msg, &flowi, fl->opt, &junk, &junk);
 358                 if (err)
 359                         goto done;
 360                 err = -EINVAL;
 361                 if (fl->opt->opt_flen)
 362                         goto done;
 363                 if (fl->opt->opt_nflen == 0) {
 364                         kfree(fl->opt);
 365                         fl->opt = NULL;
 366                 }
 367         }
 368
 369         fl->fl_net = hold_net(net);
 370         fl->expires = jiffies;
 371         err = fl6_renew(fl, freq->flr_linger, freq->flr_expires);
 372         if (err)
 373                 goto done;
 374         fl->share = freq->flr_share;
 375         addr_type = ipv6_addr_type(&freq->flr_dst);
 376         if ((addr_type&IPV6_ADDR_MAPPED)
 377             || addr_type == IPV6_ADDR_ANY) {
 378                 err = -EINVAL;
 379                 goto done;
 380         }
 381         ipv6_addr_copy(&fl->dst, &freq->flr_dst);
 382         atomic_set(&fl->users, 1);
 383         switch (fl->share) {
 384         case IPV6_FL_S_EXCL:
 385         case IPV6_FL_S_ANY:
 386                 break;
 387         case IPV6_FL_S_PROCESS:
 388                 fl->owner = current->pid;
 389                 break;
 390         case IPV6_FL_S_USER:
 391                 fl->owner = current->euid;
 392                 break;
 393         default:
 394                 err = -EINVAL;
 395                 goto done;
 396         }
 397         return fl;
 398
 399 done:
 400         fl_free(fl);
 401         *err_p = err;
 402         return NULL;
 403 }
 404
 405 static int mem_check(struct sock *sk)
 406 {
 407         struct ipv6_pinfo *np = inet6_sk(sk);
 408         struct ipv6_fl_socklist *sfl;
 409         int room = FL_MAX_SIZE - atomic_read(&fl_size);
 410         int count = 0;
 411
 412         if (room > FL_MAX_SIZE - FL_MAX_PER_SOCK)
 413                 return 0;
 414
 415         for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next)
 416                 count++;
 417
 418         if (room <= 0 ||
 419             ((count >= FL_MAX_PER_SOCK ||
 420              (count > 0 && room < FL_MAX_SIZE/2) || room < FL_MAX_SIZE/4)
 421              && !capable(CAP_NET_ADMIN)))
 422                 return -ENOBUFS;
 423
 424         return 0;
 425 }
 426
 427 static int ipv6_hdr_cmp(struct ipv6_opt_hdr *h1, struct ipv6_opt_hdr *h2)
 428 {
 429         if (h1 == h2)
 430                 return 0;
 431         if (h1 == NULL || h2 == NULL)
 432                 return 1;
 433         if (h1->hdrlen != h2->hdrlen)
 434                 return 1;
 435         return memcmp(h1+1, h2+1, ((h1->hdrlen+1)<<3) - sizeof(*h1));
 436 }
 437
 438 static int ipv6_opt_cmp(struct ipv6_txoptions *o1, struct ipv6_txoptions *o2)
 439 {
 440         if (o1 == o2)
 441                 return 0;
 442         if (o1 == NULL || o2 == NULL)
 443                 return 1;
 444         if (o1->opt_nflen != o2->opt_nflen)
 445                 return 1;
 446         if (ipv6_hdr_cmp(o1->hopopt, o2->hopopt))
 447                 return 1;
 448         if (ipv6_hdr_cmp(o1->dst0opt, o2->dst0opt))
 449                 return 1;
 450         if (ipv6_hdr_cmp((struct ipv6_opt_hdr *)o1->srcrt, (struct ipv6_opt_hdr *)o2->srcrt))
 451                 return 1;
 452         return 0;
 453 }
 454
 455 static inline void fl_link(struct ipv6_pinfo *np, struct ipv6_fl_socklist *sfl,
 456                 struct ip6_flowlabel *fl)
 457 {
 458         write_lock_bh(&ip6_sk_fl_lock);
 459         sfl->fl = fl;
 460         sfl->next = np->ipv6_fl_list;
 461         np->ipv6_fl_list = sfl;
 462         write_unlock_bh(&ip6_sk_fl_lock);
 463 }
 464
 465 int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen)
 466 {
 467         int err;
 468         struct net *net = sock_net(sk);
 469         struct ipv6_pinfo *np = inet6_sk(sk);
 470         struct in6_flowlabel_req freq;
 471         struct ipv6_fl_socklist *sfl1=NULL;
 472         struct ipv6_fl_socklist *sfl, **sflp;
 473         struct ip6_flowlabel *fl, *fl1 = NULL;
 474
 475
 476         if (optlen < sizeof(freq))
 477                 return -EINVAL;
 478
 479         if (copy_from_user(&freq, optval, sizeof(freq)))
 480                 return -EFAULT;
 481
 482         switch (freq.flr_action) {
 483         case IPV6_FL_A_PUT:
 484                 write_lock_bh(&ip6_sk_fl_lock);
 485                 for (sflp = &np->ipv6_fl_list; (sfl=*sflp)!=NULL; sflp = &sfl->next) {
 486                         if (sfl->fl->label == freq.flr_label) {
 487                                 if (freq.flr_label == (np->flow_label&IPV6_FLOWLABEL_MASK))
 488                                         np->flow_label &= ~IPV6_FLOWLABEL_MASK;
 489                                 *sflp = sfl->next;
 490                                 write_unlock_bh(&ip6_sk_fl_lock);
 491                                 fl_release(sfl->fl);
 492                                 kfree(sfl);
 493                                 return 0;
 494                         }
 495                 }
 496                 write_unlock_bh(&ip6_sk_fl_lock);
 497                 return -ESRCH;
 498
 499         case IPV6_FL_A_RENEW:
 500                 read_lock_bh(&ip6_sk_fl_lock);
 501                 for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next) {
 502                         if (sfl->fl->label == freq.flr_label) {
 503                                 err = fl6_renew(sfl->fl, freq.flr_linger, freq.flr_expires);
 504                                 read_unlock_bh(&ip6_sk_fl_lock);
 505                                 return err;
 506                         }
 507                 }
 508                 read_unlock_bh(&ip6_sk_fl_lock);
 509
 510                 if (freq.flr_share == IPV6_FL_S_NONE && capable(CAP_NET_ADMIN)) {
 511                         fl = fl_lookup(net, freq.flr_label);
 512                         if (fl) {
 513                                 err = fl6_renew(fl, freq.flr_linger, freq.flr_expires);
 514                                 fl_release(fl);
 515                                 return err;
 516                         }
 517                 }
 518                 return -ESRCH;
 519
 520         case IPV6_FL_A_GET:
 521                 if (freq.flr_label & ~IPV6_FLOWLABEL_MASK)
 522                         return -EINVAL;
 523
 524                 fl = fl_create(net, &freq, optval, optlen, &err);
 525                 if (fl == NULL)
 526                         return err;
 527                 sfl1 = kmalloc(sizeof(*sfl1), GFP_KERNEL);
 528
 529                 if (freq.flr_label) {
 530                         err = -EEXIST;
 531                         read_lock_bh(&ip6_sk_fl_lock);
 532                         for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next) {
 533                                 if (sfl->fl->label == freq.flr_label) {
 534                                         if (freq.flr_flags&IPV6_FL_F_EXCL) {
 535                                                 read_unlock_bh(&ip6_sk_fl_lock);
 536                                                 goto done;
 537                                         }
 538                                         fl1 = sfl->fl;
 539                                         atomic_inc(&fl1->users);
 540                                         break;
 541                                 }
 542                         }
 543                         read_unlock_bh(&ip6_sk_fl_lock);
 544
 545                         if (fl1 == NULL)
 546                                 fl1 = fl_lookup(net, freq.flr_label);
 547                         if (fl1) {
 548 recheck:
 549                                 err = -EEXIST;
 550                                 if (freq.flr_flags&IPV6_FL_F_EXCL)
 551                                         goto release;
 552                                 err = -EPERM;
 553                                 if (fl1->share == IPV6_FL_S_EXCL ||
 554                                     fl1->share != fl->share ||
 555                                     fl1->owner != fl->owner)
 556                                         goto release;
 557
 558                                 err = -EINVAL;
 559                                 if (!ipv6_addr_equal(&fl1->dst, &fl->dst) ||
 560                                     ipv6_opt_cmp(fl1->opt, fl->opt))
 561                                         goto release;
 562
 563                                 err = -ENOMEM;
 564                                 if (sfl1 == NULL)
 565                                         goto release;
 566                                 if (fl->linger > fl1->linger)
 567                                         fl1->linger = fl->linger;
 568                                 if ((long)(fl->expires - fl1->expires) > 0)
 569                                         fl1->expires = fl->expires;
 570                                 fl_link(np, sfl1, fl1);
 571                                 fl_free(fl);
 572                                 return 0;
 573
 574 release:
 575                                 fl_release(fl1);
 576                                 goto done;
 577                         }
 578                 }
 579                 err = -ENOENT;
 580                 if (!(freq.flr_flags&IPV6_FL_F_CREATE))
 581                         goto done;
 582
 583                 err = -ENOMEM;
 584                 if (sfl1 == NULL || (err = mem_check(sk)) != 0)
 585                         goto done;
 586
 587                 fl1 = fl_intern(net, fl, freq.flr_label);
 588                 if (fl1 != NULL)
 589                         goto recheck;
 590
 591                 if (!freq.flr_label) {
 592                         if (copy_to_user(&((struct in6_flowlabel_req __user *) optval)->flr_label,
 593                                          &fl->label, sizeof(fl->label))) {
 594                                 /* Intentionally ignore fault. */
 595                         }
 596                 }
 597
 598                 fl_link(np, sfl1, fl);
 599                 return 0;
 600
 601         default:
 602                 return -EINVAL;
 603         }
 604
 605 done:
 606         fl_free(fl);
 607         kfree(sfl1);
 608         return err;
 609 }
 610
 611 #ifdef CONFIG_PROC_FS
 612
 613 struct ip6fl_iter_state {
 614         int bucket;
 615 };
 616
 617 #define ip6fl_seq_private(seq)  ((struct ip6fl_iter_state *)(seq)->private)
 618
 619 static struct ip6_flowlabel *ip6fl_get_first(struct seq_file *seq)
 620 {
 621         struct ip6_flowlabel *fl = NULL;
 622         struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 623
 624         for (state->bucket = 0; state->bucket <= FL_HASH_MASK; ++state->bucket) {
 625                 if (fl_ht[state->bucket]) {
 626                         fl = fl_ht[state->bucket];
 627                         break;
 628                 }
 629         }
 630         return fl;
 631 }
 632
 633 static struct ip6_flowlabel *ip6fl_get_next(struct seq_file *seq, struct ip6_flowlabel *fl)
 634 {
 635         struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 636
 637         fl = fl->next;
 638         while (!fl) {
 639                 if (++state->bucket <= FL_HASH_MASK)
 640                         fl = fl_ht[state->bucket];
 641                 else
 642                         break;
 643         }
 644         return fl;
 645 }
 646
 647 static struct ip6_flowlabel *ip6fl_get_idx(struct seq_file *seq, loff_t pos)
 648 {
 649         struct ip6_flowlabel *fl = ip6fl_get_first(seq);
 650         if (fl)
 651                 while (pos && (fl = ip6fl_get_next(seq, fl)) != NULL)
 652                         --pos;
 653         return pos ? NULL : fl;
 654 }
 655
 656 static void *ip6fl_seq_start(struct seq_file *seq, loff_t *pos)
 657         __acquires(ip6_fl_lock)
 658 {
 659         read_lock_bh(&ip6_fl_lock);
 660         return *pos ? ip6fl_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
 661 }
 662
 663 static void *ip6fl_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 664 {
 665         struct ip6_flowlabel *fl;
 666
 667         if (v == SEQ_START_TOKEN)
 668                 fl = ip6fl_get_first(seq);
 669         else
 670                 fl = ip6fl_get_next(seq, v);
 671         ++*pos;
 672         return fl;
 673 }
 674
 675 static void ip6fl_seq_stop(struct seq_file *seq, void *v)
 676         __releases(ip6_fl_lock)
 677 {
 678         read_unlock_bh(&ip6_fl_lock);
 679 }
 680
 681 static int ip6fl_seq_show(struct seq_file *seq, void *v)
 682 {
 683         if (v == SEQ_START_TOKEN)
 684                 seq_printf(seq, "%-5s %-1s %-6s %-6s %-6s %-8s %-32s %s\n",
 685                            "Label", "S", "Owner", "Users", "Linger", "Expires", "Dst", "Opt");
 686         else {
 687                 struct ip6_flowlabel *fl = v;
 688                 seq_printf(seq,
 689                            "%05X %-1d %-6d %-6d %-6ld %-8ld " NIP6_SEQFMT " %-4d\n",
 690                            (unsigned)ntohl(fl->label),
 691                            fl->share,
 692                            (unsigned)fl->owner,
 693                            atomic_read(&fl->users),
 694                            fl->linger/HZ,
 695                            (long)(fl->expires - jiffies)/HZ,
 696                            NIP6(fl->dst),
 697                            fl->opt ? fl->opt->opt_nflen : 0);
 698         }
 699         return 0;
 700 }
 701
 702 static const struct seq_operations ip6fl_seq_ops = {
 703         .start  =       ip6fl_seq_start,
 704         .next   =       ip6fl_seq_next,
 705         .stop   =       ip6fl_seq_stop,
 706         .show   =       ip6fl_seq_show,
 707 };
 708
 709 static int ip6fl_seq_open(struct inode *inode, struct file *file)
 710 {
 711         return seq_open_private(file, &ip6fl_seq_ops,
 712                         sizeof(struct ip6fl_iter_state));
 713 }
 714
 715 static const struct file_operations ip6fl_seq_fops = {
 716         .owner          =       THIS_MODULE,
 717         .open           =       ip6fl_seq_open,
 718         .read           =       seq_read,
 719         .llseek         =       seq_lseek,
 720         .release        =       seq_release_private,
 721 };
 722
 723 static int ip6_flowlabel_proc_init(struct net *net)
 724 {
 725         if (!proc_net_fops_create(net, "ip6_flowlabel", S_IRUGO, &ip6fl_seq_fops))
 726                 return -ENOMEM;
 727         return 0;
 728 }
 729
 730 static void ip6_flowlabel_proc_fini(struct net *net)
 731 {
 732         proc_net_remove(net, "ip6_flowlabel");
 733 }
 734 #else
 735 static inline int ip6_flowlabel_proc_init(struct net *net)
 736 {
 737         return 0;
 738 }
 739 static inline void ip6_flowlabel_proc_fini(struct net *net)
 740 {
 741         return ;
 742 }
 743 #endif
 744
 745 static inline void ip6_flowlabel_net_exit(struct net *net)
 746 {
 747         ip6_fl_purge(net);
 748 }
 749
 750 static struct pernet_operations ip6_flowlabel_net_ops = {
 751         .exit = ip6_flowlabel_net_exit,
 752 };
 753
 754 int ip6_flowlabel_init(void)
 755 {
 756         int err;
 757
 758         err = register_pernet_subsys(&ip6_flowlabel_net_ops);
 759         if (err)
 760                 return err;
 761         return ip6_flowlabel_proc_init(&init_net);
 762 }
 763
 764 void ip6_flowlabel_cleanup(void)
 765 {
 766         del_timer(&ip6_fl_gc_timer);
 767         unregister_pernet_subsys(&ip6_flowlabel_net_ops);
 768         ip6_flowlabel_proc_fini(&init_net);
 769 }