net/ipv6/ip6_flowlabel.c

   1 /*
   2  *      ip6_flowlabel.c         IPv6 flowlabel manager.
   3  *
   4  *      This program is free software; you can redistribute it and/or
   5  *      modify it under the terms of the GNU General Public License
   6  *      as published by the Free Software Foundation; either version
   7  *      2 of the License, or (at your option) any later version.
   8  *
   9  *      Authors:        Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
  10  */
  11
  12 #include <linux/capability.h>
  13 #include <linux/errno.h>
  14 #include <linux/types.h>
  15 #include <linux/socket.h>
  16 #include <linux/net.h>
  17 #include <linux/netdevice.h>
  18 #include <linux/if_arp.h>
  19 #include <linux/in6.h>
  20 #include <linux/route.h>
  21 #include <linux/proc_fs.h>
  22 #include <linux/seq_file.h>
  23
  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(__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)
  71                         return fl;
  72         }
  73         return NULL;
  74 }
  75
  76 static struct ip6_flowlabel * fl_lookup(__be32 label)
  77 {
  78         struct ip6_flowlabel *fl;
  79
  80         read_lock_bh(&ip6_fl_lock);
  81         fl = __fl_lookup(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                 kfree(fl->opt);
  93         kfree(fl);
  94 }
  95
  96 static void fl_release(struct ip6_flowlabel *fl)
  97 {
  98         write_lock_bh(&ip6_fl_lock);
  99
 100         fl->lastuse = jiffies;
 101         if (atomic_dec_and_test(&fl->users)) {
 102                 unsigned long ttd = fl->lastuse + fl->linger;
 103                 if (time_after(ttd, fl->expires))
 104                         fl->expires = ttd;
 105                 ttd = fl->expires;
 106                 if (fl->opt && fl->share == IPV6_FL_S_EXCL) {
 107                         struct ipv6_txoptions *opt = fl->opt;
 108                         fl->opt = NULL;
 109                         kfree(opt);
 110                 }
 111                 if (!timer_pending(&ip6_fl_gc_timer) ||
 112                     time_after(ip6_fl_gc_timer.expires, ttd))
 113                         mod_timer(&ip6_fl_gc_timer, ttd);
 114         }
 115
 116         write_unlock_bh(&ip6_fl_lock);
 117 }
 118
 119 static void ip6_fl_gc(unsigned long dummy)
 120 {
 121         int i;
 122         unsigned long now = jiffies;
 123         unsigned long sched = 0;
 124
 125         write_lock(&ip6_fl_lock);
 126
 127         for (i=0; i<=FL_HASH_MASK; i++) {
 128                 struct ip6_flowlabel *fl, **flp;
 129                 flp = &fl_ht[i];
 130                 while ((fl=*flp) != NULL) {
 131                         if (atomic_read(&fl->users) == 0) {
 132                                 unsigned long ttd = fl->lastuse + fl->linger;
 133                                 if (time_after(ttd, fl->expires))
 134                                         fl->expires = ttd;
 135                                 ttd = fl->expires;
 136                                 if (time_after_eq(now, ttd)) {
 137                                         *flp = fl->next;
 138                                         fl_free(fl);
 139                                         atomic_dec(&fl_size);
 140                                         continue;
 141                                 }
 142                                 if (!sched || time_before(ttd, sched))
 143                                         sched = ttd;
 144                         }
 145                         flp = &fl->next;
 146                 }
 147         }
 148         if (!sched && atomic_read(&fl_size))
 149                 sched = now + FL_MAX_LINGER;
 150         if (sched) {
 151                 ip6_fl_gc_timer.expires = sched;
 152                 add_timer(&ip6_fl_gc_timer);
 153         }
 154         write_unlock(&ip6_fl_lock);
 155 }
 156
 157 static struct ip6_flowlabel *fl_intern(struct ip6_flowlabel *fl, __be32 label)
 158 {
 159         struct ip6_flowlabel *lfl;
 160
 161         fl->label = label & IPV6_FLOWLABEL_MASK;
 162
 163         write_lock_bh(&ip6_fl_lock);
 164         if (label == 0) {
 165                 for (;;) {
 166                         fl->label = htonl(net_random())&IPV6_FLOWLABEL_MASK;
 167                         if (fl->label) {
 168                                 lfl = __fl_lookup(fl->label);
 169                                 if (lfl == NULL)
 170                                         break;
 171                         }
 172                 }
 173         } else {
 174                 /*
 175                  * we dropper the ip6_fl_lock, so this entry could reappear
 176                  * and we need to recheck with it.
 177                  *
 178                  * OTOH no need to search the active socket first, like it is
 179                  * done in ipv6_flowlabel_opt - sock is locked, so new entry
 180                  * with the same label can only appear on another sock
 181                  */
 182                 lfl = __fl_lookup(fl->label);
 183                 if (lfl != NULL) {
 184                         atomic_inc(&lfl->users);
 185                         write_unlock_bh(&ip6_fl_lock);
 186                         return lfl;
 187                 }
 188         }
 189
 190         fl->lastuse = jiffies;
 191         fl->next = fl_ht[FL_HASH(fl->label)];
 192         fl_ht[FL_HASH(fl->label)] = fl;
 193         atomic_inc(&fl_size);
 194         write_unlock_bh(&ip6_fl_lock);
 195         return NULL;
 196 }
 197
 198
 199
 200 /* Socket flowlabel lists */
 201
 202 struct ip6_flowlabel * fl6_sock_lookup(struct sock *sk, __be32 label)
 203 {
 204         struct ipv6_fl_socklist *sfl;
 205         struct ipv6_pinfo *np = inet6_sk(sk);
 206
 207         label &= IPV6_FLOWLABEL_MASK;
 208
 209         read_lock_bh(&ip6_sk_fl_lock);
 210         for (sfl=np->ipv6_fl_list; sfl; sfl = sfl->next) {
 211                 struct ip6_flowlabel *fl = sfl->fl;
 212                 if (fl->label == label) {
 213                         fl->lastuse = jiffies;
 214                         atomic_inc(&fl->users);
 215                         read_unlock_bh(&ip6_sk_fl_lock);
 216                         return fl;
 217                 }
 218         }
 219         read_unlock_bh(&ip6_sk_fl_lock);
 220         return NULL;
 221 }
 222
 223 EXPORT_SYMBOL_GPL(fl6_sock_lookup);
 224
 225 void fl6_free_socklist(struct sock *sk)
 226 {
 227         struct ipv6_pinfo *np = inet6_sk(sk);
 228         struct ipv6_fl_socklist *sfl;
 229
 230         while ((sfl = np->ipv6_fl_list) != NULL) {
 231                 np->ipv6_fl_list = sfl->next;
 232                 fl_release(sfl->fl);
 233                 kfree(sfl);
 234         }
 235 }
 236
 237 /* Service routines */
 238
 239
 240 /*
 241    It is the only difficult place. flowlabel enforces equal headers
 242    before and including routing header, however user may supply options
 243    following rthdr.
 244  */
 245
 246 struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions * opt_space,
 247                                          struct ip6_flowlabel * fl,
 248                                          struct ipv6_txoptions * fopt)
 249 {
 250         struct ipv6_txoptions * fl_opt = fl->opt;
 251
 252         if (fopt == NULL || fopt->opt_flen == 0)
 253                 return fl_opt;
 254
 255         if (fl_opt != NULL) {
 256                 opt_space->hopopt = fl_opt->hopopt;
 257                 opt_space->dst0opt = fl_opt->dst0opt;
 258                 opt_space->srcrt = fl_opt->srcrt;
 259                 opt_space->opt_nflen = fl_opt->opt_nflen;
 260         } else {
 261                 if (fopt->opt_nflen == 0)
 262                         return fopt;
 263                 opt_space->hopopt = NULL;
 264                 opt_space->dst0opt = NULL;
 265                 opt_space->srcrt = NULL;
 266                 opt_space->opt_nflen = 0;
 267         }
 268         opt_space->dst1opt = fopt->dst1opt;
 269         opt_space->opt_flen = fopt->opt_flen;
 270         return opt_space;
 271 }
 272
 273 static unsigned long check_linger(unsigned long ttl)
 274 {
 275         if (ttl < FL_MIN_LINGER)
 276                 return FL_MIN_LINGER*HZ;
 277         if (ttl > FL_MAX_LINGER && !capable(CAP_NET_ADMIN))
 278                 return 0;
 279         return ttl*HZ;
 280 }
 281
 282 static int fl6_renew(struct ip6_flowlabel *fl, unsigned long linger, unsigned long expires)
 283 {
 284         linger = check_linger(linger);
 285         if (!linger)
 286                 return -EPERM;
 287         expires = check_linger(expires);
 288         if (!expires)
 289                 return -EPERM;
 290         fl->lastuse = jiffies;
 291         if (time_before(fl->linger, linger))
 292                 fl->linger = linger;
 293         if (time_before(expires, fl->linger))
 294                 expires = fl->linger;
 295         if (time_before(fl->expires, fl->lastuse + expires))
 296                 fl->expires = fl->lastuse + expires;
 297         return 0;
 298 }
 299
 300 static struct ip6_flowlabel *
 301 fl_create(struct in6_flowlabel_req *freq, char __user *optval, int optlen, int *err_p)
 302 {
 303         struct ip6_flowlabel *fl;
 304         int olen;
 305         int addr_type;
 306         int err;
 307
 308         err = -ENOMEM;
 309         fl = kzalloc(sizeof(*fl), GFP_KERNEL);
 310         if (fl == NULL)
 311                 goto done;
 312
 313         olen = optlen - CMSG_ALIGN(sizeof(*freq));
 314         if (olen > 0) {
 315                 struct msghdr msg;
 316                 struct flowi flowi;
 317                 int junk;
 318
 319                 err = -ENOMEM;
 320                 fl->opt = kmalloc(sizeof(*fl->opt) + olen, GFP_KERNEL);
 321                 if (fl->opt == NULL)
 322                         goto done;
 323
 324                 memset(fl->opt, 0, sizeof(*fl->opt));
 325                 fl->opt->tot_len = sizeof(*fl->opt) + olen;
 326                 err = -EFAULT;
 327                 if (copy_from_user(fl->opt+1, optval+CMSG_ALIGN(sizeof(*freq)), olen))
 328                         goto done;
 329
 330                 msg.msg_controllen = olen;
 331                 msg.msg_control = (void*)(fl->opt+1);
 332                 flowi.oif = 0;
 333
 334                 err = datagram_send_ctl(&msg, &flowi, fl->opt, &junk, &junk);
 335                 if (err)
 336                         goto done;
 337                 err = -EINVAL;
 338                 if (fl->opt->opt_flen)
 339                         goto done;
 340                 if (fl->opt->opt_nflen == 0) {
 341                         kfree(fl->opt);
 342                         fl->opt = NULL;
 343                 }
 344         }
 345
 346         fl->expires = jiffies;
 347         err = fl6_renew(fl, freq->flr_linger, freq->flr_expires);
 348         if (err)
 349                 goto done;
 350         fl->share = freq->flr_share;
 351         addr_type = ipv6_addr_type(&freq->flr_dst);
 352         if ((addr_type&IPV6_ADDR_MAPPED)
 353             || addr_type == IPV6_ADDR_ANY) {
 354                 err = -EINVAL;
 355                 goto done;
 356         }
 357         ipv6_addr_copy(&fl->dst, &freq->flr_dst);
 358         atomic_set(&fl->users, 1);
 359         switch (fl->share) {
 360         case IPV6_FL_S_EXCL:
 361         case IPV6_FL_S_ANY:
 362                 break;
 363         case IPV6_FL_S_PROCESS:
 364                 fl->owner = current->pid;
 365                 break;
 366         case IPV6_FL_S_USER:
 367                 fl->owner = current->euid;
 368                 break;
 369         default:
 370                 err = -EINVAL;
 371                 goto done;
 372         }
 373         return fl;
 374
 375 done:
 376         fl_free(fl);
 377         *err_p = err;
 378         return NULL;
 379 }
 380
 381 static int mem_check(struct sock *sk)
 382 {
 383         struct ipv6_pinfo *np = inet6_sk(sk);
 384         struct ipv6_fl_socklist *sfl;
 385         int room = FL_MAX_SIZE - atomic_read(&fl_size);
 386         int count = 0;
 387
 388         if (room > FL_MAX_SIZE - FL_MAX_PER_SOCK)
 389                 return 0;
 390
 391         for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next)
 392                 count++;
 393
 394         if (room <= 0 ||
 395             ((count >= FL_MAX_PER_SOCK ||
 396              (count > 0 && room < FL_MAX_SIZE/2) || room < FL_MAX_SIZE/4)
 397              && !capable(CAP_NET_ADMIN)))
 398                 return -ENOBUFS;
 399
 400         return 0;
 401 }
 402
 403 static int ipv6_hdr_cmp(struct ipv6_opt_hdr *h1, struct ipv6_opt_hdr *h2)
 404 {
 405         if (h1 == h2)
 406                 return 0;
 407         if (h1 == NULL || h2 == NULL)
 408                 return 1;
 409         if (h1->hdrlen != h2->hdrlen)
 410                 return 1;
 411         return memcmp(h1+1, h2+1, ((h1->hdrlen+1)<<3) - sizeof(*h1));
 412 }
 413
 414 static int ipv6_opt_cmp(struct ipv6_txoptions *o1, struct ipv6_txoptions *o2)
 415 {
 416         if (o1 == o2)
 417                 return 0;
 418         if (o1 == NULL || o2 == NULL)
 419                 return 1;
 420         if (o1->opt_nflen != o2->opt_nflen)
 421                 return 1;
 422         if (ipv6_hdr_cmp(o1->hopopt, o2->hopopt))
 423                 return 1;
 424         if (ipv6_hdr_cmp(o1->dst0opt, o2->dst0opt))
 425                 return 1;
 426         if (ipv6_hdr_cmp((struct ipv6_opt_hdr *)o1->srcrt, (struct ipv6_opt_hdr *)o2->srcrt))
 427                 return 1;
 428         return 0;
 429 }
 430
 431 static inline void fl_link(struct ipv6_pinfo *np, struct ipv6_fl_socklist *sfl,
 432                 struct ip6_flowlabel *fl)
 433 {
 434         write_lock_bh(&ip6_sk_fl_lock);
 435         sfl->fl = fl;
 436         sfl->next = np->ipv6_fl_list;
 437         np->ipv6_fl_list = sfl;
 438         write_unlock_bh(&ip6_sk_fl_lock);
 439 }
 440
 441 int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen)
 442 {
 443         int err;
 444         struct ipv6_pinfo *np = inet6_sk(sk);
 445         struct in6_flowlabel_req freq;
 446         struct ipv6_fl_socklist *sfl1=NULL;
 447         struct ipv6_fl_socklist *sfl, **sflp;
 448         struct ip6_flowlabel *fl, *fl1 = NULL;
 449
 450
 451         if (optlen < sizeof(freq))
 452                 return -EINVAL;
 453
 454         if (copy_from_user(&freq, optval, sizeof(freq)))
 455                 return -EFAULT;
 456
 457         switch (freq.flr_action) {
 458         case IPV6_FL_A_PUT:
 459                 write_lock_bh(&ip6_sk_fl_lock);
 460                 for (sflp = &np->ipv6_fl_list; (sfl=*sflp)!=NULL; sflp = &sfl->next) {
 461                         if (sfl->fl->label == freq.flr_label) {
 462                                 if (freq.flr_label == (np->flow_label&IPV6_FLOWLABEL_MASK))
 463                                         np->flow_label &= ~IPV6_FLOWLABEL_MASK;
 464                                 *sflp = sfl->next;
 465                                 write_unlock_bh(&ip6_sk_fl_lock);
 466                                 fl_release(sfl->fl);
 467                                 kfree(sfl);
 468                                 return 0;
 469                         }
 470                 }
 471                 write_unlock_bh(&ip6_sk_fl_lock);
 472                 return -ESRCH;
 473
 474         case IPV6_FL_A_RENEW:
 475                 read_lock_bh(&ip6_sk_fl_lock);
 476                 for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next) {
 477                         if (sfl->fl->label == freq.flr_label) {
 478                                 err = fl6_renew(sfl->fl, freq.flr_linger, freq.flr_expires);
 479                                 read_unlock_bh(&ip6_sk_fl_lock);
 480                                 return err;
 481                         }
 482                 }
 483                 read_unlock_bh(&ip6_sk_fl_lock);
 484
 485                 if (freq.flr_share == IPV6_FL_S_NONE && capable(CAP_NET_ADMIN)) {
 486                         fl = fl_lookup(freq.flr_label);
 487                         if (fl) {
 488                                 err = fl6_renew(fl, freq.flr_linger, freq.flr_expires);
 489                                 fl_release(fl);
 490                                 return err;
 491                         }
 492                 }
 493                 return -ESRCH;
 494
 495         case IPV6_FL_A_GET:
 496                 if (freq.flr_label & ~IPV6_FLOWLABEL_MASK)
 497                         return -EINVAL;
 498
 499                 fl = fl_create(&freq, optval, optlen, &err);
 500                 if (fl == NULL)
 501                         return err;
 502                 sfl1 = kmalloc(sizeof(*sfl1), GFP_KERNEL);
 503
 504                 if (freq.flr_label) {
 505                         err = -EEXIST;
 506                         read_lock_bh(&ip6_sk_fl_lock);
 507                         for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next) {
 508                                 if (sfl->fl->label == freq.flr_label) {
 509                                         if (freq.flr_flags&IPV6_FL_F_EXCL) {
 510                                                 read_unlock_bh(&ip6_sk_fl_lock);
 511                                                 goto done;
 512                                         }
 513                                         fl1 = sfl->fl;
 514                                         atomic_inc(&fl1->users);
 515                                         break;
 516                                 }
 517                         }
 518                         read_unlock_bh(&ip6_sk_fl_lock);
 519
 520                         if (fl1 == NULL)
 521                                 fl1 = fl_lookup(freq.flr_label);
 522                         if (fl1) {
 523 recheck:
 524                                 err = -EEXIST;
 525                                 if (freq.flr_flags&IPV6_FL_F_EXCL)
 526                                         goto release;
 527                                 err = -EPERM;
 528                                 if (fl1->share == IPV6_FL_S_EXCL ||
 529                                     fl1->share != fl->share ||
 530                                     fl1->owner != fl->owner)
 531                                         goto release;
 532
 533                                 err = -EINVAL;
 534                                 if (!ipv6_addr_equal(&fl1->dst, &fl->dst) ||
 535                                     ipv6_opt_cmp(fl1->opt, fl->opt))
 536                                         goto release;
 537
 538                                 err = -ENOMEM;
 539                                 if (sfl1 == NULL)
 540                                         goto release;
 541                                 if (fl->linger > fl1->linger)
 542                                         fl1->linger = fl->linger;
 543                                 if ((long)(fl->expires - fl1->expires) > 0)
 544                                         fl1->expires = fl->expires;
 545                                 fl_link(np, sfl1, fl1);
 546                                 fl_free(fl);
 547                                 return 0;
 548
 549 release:
 550                                 fl_release(fl1);
 551                                 goto done;
 552                         }
 553                 }
 554                 err = -ENOENT;
 555                 if (!(freq.flr_flags&IPV6_FL_F_CREATE))
 556                         goto done;
 557
 558                 err = -ENOMEM;
 559                 if (sfl1 == NULL || (err = mem_check(sk)) != 0)
 560                         goto done;
 561
 562                 fl1 = fl_intern(fl, freq.flr_label);
 563                 if (fl1 != NULL)
 564                         goto recheck;
 565
 566                 if (!freq.flr_label) {
 567                         if (copy_to_user(&((struct in6_flowlabel_req __user *) optval)->flr_label,
 568                                          &fl->label, sizeof(fl->label))) {
 569                                 /* Intentionally ignore fault. */
 570                         }
 571                 }
 572
 573                 fl_link(np, sfl1, fl);
 574                 return 0;
 575
 576         default:
 577                 return -EINVAL;
 578         }
 579
 580 done:
 581         fl_free(fl);
 582         kfree(sfl1);
 583         return err;
 584 }
 585
 586 #ifdef CONFIG_PROC_FS
 587
 588 struct ip6fl_iter_state {
 589         int bucket;
 590 };
 591
 592 #define ip6fl_seq_private(seq)  ((struct ip6fl_iter_state *)(seq)->private)
 593
 594 static struct ip6_flowlabel *ip6fl_get_first(struct seq_file *seq)
 595 {
 596         struct ip6_flowlabel *fl = NULL;
 597         struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 598
 599         for (state->bucket = 0; state->bucket <= FL_HASH_MASK; ++state->bucket) {
 600                 if (fl_ht[state->bucket]) {
 601                         fl = fl_ht[state->bucket];
 602                         break;
 603                 }
 604         }
 605         return fl;
 606 }
 607
 608 static struct ip6_flowlabel *ip6fl_get_next(struct seq_file *seq, struct ip6_flowlabel *fl)
 609 {
 610         struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 611
 612         fl = fl->next;
 613         while (!fl) {
 614                 if (++state->bucket <= FL_HASH_MASK)
 615                         fl = fl_ht[state->bucket];
 616                 else
 617                         break;
 618         }
 619         return fl;
 620 }
 621
 622 static struct ip6_flowlabel *ip6fl_get_idx(struct seq_file *seq, loff_t pos)
 623 {
 624         struct ip6_flowlabel *fl = ip6fl_get_first(seq);
 625         if (fl)
 626                 while (pos && (fl = ip6fl_get_next(seq, fl)) != NULL)
 627                         --pos;
 628         return pos ? NULL : fl;
 629 }
 630
 631 static void *ip6fl_seq_start(struct seq_file *seq, loff_t *pos)
 632         __acquires(ip6_fl_lock)
 633 {
 634         read_lock_bh(&ip6_fl_lock);
 635         return *pos ? ip6fl_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
 636 }
 637
 638 static void *ip6fl_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 639 {
 640         struct ip6_flowlabel *fl;
 641
 642         if (v == SEQ_START_TOKEN)
 643                 fl = ip6fl_get_first(seq);
 644         else
 645                 fl = ip6fl_get_next(seq, v);
 646         ++*pos;
 647         return fl;
 648 }
 649
 650 static void ip6fl_seq_stop(struct seq_file *seq, void *v)
 651         __releases(ip6_fl_lock)
 652 {
 653         read_unlock_bh(&ip6_fl_lock);
 654 }
 655
 656 static int ip6fl_seq_show(struct seq_file *seq, void *v)
 657 {
 658         if (v == SEQ_START_TOKEN)
 659                 seq_printf(seq, "%-5s %-1s %-6s %-6s %-6s %-8s %-32s %s\n",
 660                            "Label", "S", "Owner", "Users", "Linger", "Expires", "Dst", "Opt");
 661         else {
 662                 struct ip6_flowlabel *fl = v;
 663                 seq_printf(seq,
 664                            "%05X %-1d %-6d %-6d %-6ld %-8ld " NIP6_SEQFMT " %-4d\n",
 665                            (unsigned)ntohl(fl->label),
 666                            fl->share,
 667                            (unsigned)fl->owner,
 668                            atomic_read(&fl->users),
 669                            fl->linger/HZ,
 670                            (long)(fl->expires - jiffies)/HZ,
 671                            NIP6(fl->dst),
 672                            fl->opt ? fl->opt->opt_nflen : 0);
 673         }
 674         return 0;
 675 }
 676
 677 static const struct seq_operations ip6fl_seq_ops = {
 678         .start  =       ip6fl_seq_start,
 679         .next   =       ip6fl_seq_next,
 680         .stop   =       ip6fl_seq_stop,
 681         .show   =       ip6fl_seq_show,
 682 };
 683
 684 static int ip6fl_seq_open(struct inode *inode, struct file *file)
 685 {
 686         return seq_open_private(file, &ip6fl_seq_ops,
 687                         sizeof(struct ip6fl_iter_state));
 688 }
 689
 690 static const struct file_operations ip6fl_seq_fops = {
 691         .owner          =       THIS_MODULE,
 692         .open           =       ip6fl_seq_open,
 693         .read           =       seq_read,
 694         .llseek         =       seq_lseek,
 695         .release        =       seq_release_private,
 696 };
 697
 698 static int ip6_flowlabel_proc_init(struct net *net)
 699 {
 700         if (!proc_net_fops_create(net, "ip6_flowlabel", S_IRUGO, &ip6fl_seq_fops))
 701                 return -ENOMEM;
 702         return 0;
 703 }
 704
 705 static void ip6_flowlabel_proc_fini(struct net *net)
 706 {
 707         proc_net_remove(net, "ip6_flowlabel");
 708 }
 709 #else
 710 static inline int ip6_flowlabel_proc_init(struct net *net)
 711 {
 712         return 0;
 713 }
 714 static inline void ip6_flowlabel_proc_fini(struct net *net)
 715 {
 716         return ;
 717 }
 718 #endif
 719
 720 int ip6_flowlabel_init(void)
 721 {
 722         return ip6_flowlabel_proc_init(&init_net);
 723 }
 724
 725 void ip6_flowlabel_cleanup(void)
 726 {
 727         del_timer(&ip6_fl_gc_timer);
 728         ip6_flowlabel_proc_fini(&init_net);
 729 }