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/config.h>
  14 #include <linux/errno.h>
  15 #include <linux/types.h>
  16 #include <linux/socket.h>
  17 #include <linux/net.h>
  18 #include <linux/netdevice.h>
  19 #include <linux/if_arp.h>
  20 #include <linux/in6.h>
  21 #include <linux/route.h>
  22 #include <linux/proc_fs.h>
  23 #include <linux/seq_file.h>
  24
  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(u32 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(u32 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 int fl_intern(struct ip6_flowlabel *fl, __u32 label)
 158 {
 159         fl->label = label & IPV6_FLOWLABEL_MASK;
 160
 161         write_lock_bh(&ip6_fl_lock);
 162         if (label == 0) {
 163                 for (;;) {
 164                         fl->label = htonl(net_random())&IPV6_FLOWLABEL_MASK;
 165                         if (fl->label) {
 166                                 struct ip6_flowlabel *lfl;
 167                                 lfl = __fl_lookup(fl->label);
 168                                 if (lfl == NULL)
 169                                         break;
 170                         }
 171                 }
 172         }
 173
 174         fl->lastuse = jiffies;
 175         fl->next = fl_ht[FL_HASH(fl->label)];
 176         fl_ht[FL_HASH(fl->label)] = fl;
 177         atomic_inc(&fl_size);
 178         write_unlock_bh(&ip6_fl_lock);
 179         return 0;
 180 }
 181
 182
 183
 184 /* Socket flowlabel lists */
 185
 186 struct ip6_flowlabel * fl6_sock_lookup(struct sock *sk, u32 label)
 187 {
 188         struct ipv6_fl_socklist *sfl;
 189         struct ipv6_pinfo *np = inet6_sk(sk);
 190
 191         label &= IPV6_FLOWLABEL_MASK;
 192
 193         for (sfl=np->ipv6_fl_list; sfl; sfl = sfl->next) {
 194                 struct ip6_flowlabel *fl = sfl->fl;
 195                 if (fl->label == label) {
 196                         fl->lastuse = jiffies;
 197                         atomic_inc(&fl->users);
 198                         return fl;
 199                 }
 200         }
 201         return NULL;
 202 }
 203
 204 EXPORT_SYMBOL_GPL(fl6_sock_lookup);
 205
 206 void fl6_free_socklist(struct sock *sk)
 207 {
 208         struct ipv6_pinfo *np = inet6_sk(sk);
 209         struct ipv6_fl_socklist *sfl;
 210
 211         while ((sfl = np->ipv6_fl_list) != NULL) {
 212                 np->ipv6_fl_list = sfl->next;
 213                 fl_release(sfl->fl);
 214                 kfree(sfl);
 215         }
 216 }
 217
 218 /* Service routines */
 219
 220
 221 /*
 222    It is the only difficult place. flowlabel enforces equal headers
 223    before and including routing header, however user may supply options
 224    following rthdr.
 225  */
 226
 227 struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions * opt_space,
 228                                          struct ip6_flowlabel * fl,
 229                                          struct ipv6_txoptions * fopt)
 230 {
 231         struct ipv6_txoptions * fl_opt = fl->opt;
 232
 233         if (fopt == NULL || fopt->opt_flen == 0)
 234                 return fl_opt;
 235
 236         if (fl_opt != NULL) {
 237                 opt_space->hopopt = fl_opt->hopopt;
 238                 opt_space->dst0opt = fl_opt->dst0opt;
 239                 opt_space->srcrt = fl_opt->srcrt;
 240                 opt_space->opt_nflen = fl_opt->opt_nflen;
 241         } else {
 242                 if (fopt->opt_nflen == 0)
 243                         return fopt;
 244                 opt_space->hopopt = NULL;
 245                 opt_space->dst0opt = NULL;
 246                 opt_space->srcrt = NULL;
 247                 opt_space->opt_nflen = 0;
 248         }
 249         opt_space->dst1opt = fopt->dst1opt;
 250         opt_space->opt_flen = fopt->opt_flen;
 251         return opt_space;
 252 }
 253
 254 static unsigned long check_linger(unsigned long ttl)
 255 {
 256         if (ttl < FL_MIN_LINGER)
 257                 return FL_MIN_LINGER*HZ;
 258         if (ttl > FL_MAX_LINGER && !capable(CAP_NET_ADMIN))
 259                 return 0;
 260         return ttl*HZ;
 261 }
 262
 263 static int fl6_renew(struct ip6_flowlabel *fl, unsigned long linger, unsigned long expires)
 264 {
 265         linger = check_linger(linger);
 266         if (!linger)
 267                 return -EPERM;
 268         expires = check_linger(expires);
 269         if (!expires)
 270                 return -EPERM;
 271         fl->lastuse = jiffies;
 272         if (time_before(fl->linger, linger))
 273                 fl->linger = linger;
 274         if (time_before(expires, fl->linger))
 275                 expires = fl->linger;
 276         if (time_before(fl->expires, fl->lastuse + expires))
 277                 fl->expires = fl->lastuse + expires;
 278         return 0;
 279 }
 280
 281 static struct ip6_flowlabel *
 282 fl_create(struct in6_flowlabel_req *freq, char __user *optval, int optlen, int *err_p)
 283 {
 284         struct ip6_flowlabel *fl;
 285         int olen;
 286         int addr_type;
 287         int err;
 288
 289         err = -ENOMEM;
 290         fl = kmalloc(sizeof(*fl), GFP_KERNEL);
 291         if (fl == NULL)
 292                 goto done;
 293         memset(fl, 0, sizeof(*fl));
 294
 295         olen = optlen - CMSG_ALIGN(sizeof(*freq));
 296         if (olen > 0) {
 297                 struct msghdr msg;
 298                 struct flowi flowi;
 299                 int junk;
 300
 301                 err = -ENOMEM;
 302                 fl->opt = kmalloc(sizeof(*fl->opt) + olen, GFP_KERNEL);
 303                 if (fl->opt == NULL)
 304                         goto done;
 305
 306                 memset(fl->opt, 0, sizeof(*fl->opt));
 307                 fl->opt->tot_len = sizeof(*fl->opt) + olen;
 308                 err = -EFAULT;
 309                 if (copy_from_user(fl->opt+1, optval+CMSG_ALIGN(sizeof(*freq)), olen))
 310                         goto done;
 311
 312                 msg.msg_controllen = olen;
 313                 msg.msg_control = (void*)(fl->opt+1);
 314                 flowi.oif = 0;
 315
 316                 err = datagram_send_ctl(&msg, &flowi, fl->opt, &junk, &junk);
 317                 if (err)
 318                         goto done;
 319                 err = -EINVAL;
 320                 if (fl->opt->opt_flen)
 321                         goto done;
 322                 if (fl->opt->opt_nflen == 0) {
 323                         kfree(fl->opt);
 324                         fl->opt = NULL;
 325                 }
 326         }
 327
 328         fl->expires = jiffies;
 329         err = fl6_renew(fl, freq->flr_linger, freq->flr_expires);
 330         if (err)
 331                 goto done;
 332         fl->share = freq->flr_share;
 333         addr_type = ipv6_addr_type(&freq->flr_dst);
 334         if ((addr_type&IPV6_ADDR_MAPPED)
 335             || addr_type == IPV6_ADDR_ANY)
 336                 goto done;
 337         ipv6_addr_copy(&fl->dst, &freq->flr_dst);
 338         atomic_set(&fl->users, 1);
 339         switch (fl->share) {
 340         case IPV6_FL_S_EXCL:
 341         case IPV6_FL_S_ANY:
 342                 break;
 343         case IPV6_FL_S_PROCESS:
 344                 fl->owner = current->pid;
 345                 break;
 346         case IPV6_FL_S_USER:
 347                 fl->owner = current->euid;
 348                 break;
 349         default:
 350                 err = -EINVAL;
 351                 goto done;
 352         }
 353         return fl;
 354
 355 done:
 356         fl_free(fl);
 357         *err_p = err;
 358         return NULL;
 359 }
 360
 361 static int mem_check(struct sock *sk)
 362 {
 363         struct ipv6_pinfo *np = inet6_sk(sk);
 364         struct ipv6_fl_socklist *sfl;
 365         int room = FL_MAX_SIZE - atomic_read(&fl_size);
 366         int count = 0;
 367
 368         if (room > FL_MAX_SIZE - FL_MAX_PER_SOCK)
 369                 return 0;
 370
 371         for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next)
 372                 count++;
 373
 374         if (room <= 0 ||
 375             ((count >= FL_MAX_PER_SOCK ||
 376              (count > 0 && room < FL_MAX_SIZE/2) || room < FL_MAX_SIZE/4)
 377              && !capable(CAP_NET_ADMIN)))
 378                 return -ENOBUFS;
 379
 380         return 0;
 381 }
 382
 383 static int ipv6_hdr_cmp(struct ipv6_opt_hdr *h1, struct ipv6_opt_hdr *h2)
 384 {
 385         if (h1 == h2)
 386                 return 0;
 387         if (h1 == NULL || h2 == NULL)
 388                 return 1;
 389         if (h1->hdrlen != h2->hdrlen)
 390                 return 1;
 391         return memcmp(h1+1, h2+1, ((h1->hdrlen+1)<<3) - sizeof(*h1));
 392 }
 393
 394 static int ipv6_opt_cmp(struct ipv6_txoptions *o1, struct ipv6_txoptions *o2)
 395 {
 396         if (o1 == o2)
 397                 return 0;
 398         if (o1 == NULL || o2 == NULL)
 399                 return 1;
 400         if (o1->opt_nflen != o2->opt_nflen)
 401                 return 1;
 402         if (ipv6_hdr_cmp(o1->hopopt, o2->hopopt))
 403                 return 1;
 404         if (ipv6_hdr_cmp(o1->dst0opt, o2->dst0opt))
 405                 return 1;
 406         if (ipv6_hdr_cmp((struct ipv6_opt_hdr *)o1->srcrt, (struct ipv6_opt_hdr *)o2->srcrt))
 407                 return 1;
 408         return 0;
 409 }
 410
 411 int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen)
 412 {
 413         int err;
 414         struct ipv6_pinfo *np = inet6_sk(sk);
 415         struct in6_flowlabel_req freq;
 416         struct ipv6_fl_socklist *sfl1=NULL;
 417         struct ipv6_fl_socklist *sfl, **sflp;
 418         struct ip6_flowlabel *fl;
 419
 420         if (optlen < sizeof(freq))
 421                 return -EINVAL;
 422
 423         if (copy_from_user(&freq, optval, sizeof(freq)))
 424                 return -EFAULT;
 425
 426         switch (freq.flr_action) {
 427         case IPV6_FL_A_PUT:
 428                 write_lock_bh(&ip6_sk_fl_lock);
 429                 for (sflp = &np->ipv6_fl_list; (sfl=*sflp)!=NULL; sflp = &sfl->next) {
 430                         if (sfl->fl->label == freq.flr_label) {
 431                                 if (freq.flr_label == (np->flow_label&IPV6_FLOWLABEL_MASK))
 432                                         np->flow_label &= ~IPV6_FLOWLABEL_MASK;
 433                                 *sflp = sfl->next;
 434                                 write_unlock_bh(&ip6_sk_fl_lock);
 435                                 fl_release(sfl->fl);
 436                                 kfree(sfl);
 437                                 return 0;
 438                         }
 439                 }
 440                 write_unlock_bh(&ip6_sk_fl_lock);
 441                 return -ESRCH;
 442
 443         case IPV6_FL_A_RENEW:
 444                 read_lock_bh(&ip6_sk_fl_lock);
 445                 for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next) {
 446                         if (sfl->fl->label == freq.flr_label) {
 447                                 err = fl6_renew(sfl->fl, freq.flr_linger, freq.flr_expires);
 448                                 read_unlock_bh(&ip6_sk_fl_lock);
 449                                 return err;
 450                         }
 451                 }
 452                 read_unlock_bh(&ip6_sk_fl_lock);
 453
 454                 if (freq.flr_share == IPV6_FL_S_NONE && capable(CAP_NET_ADMIN)) {
 455                         fl = fl_lookup(freq.flr_label);
 456                         if (fl) {
 457                                 err = fl6_renew(fl, freq.flr_linger, freq.flr_expires);
 458                                 fl_release(fl);
 459                                 return err;
 460                         }
 461                 }
 462                 return -ESRCH;
 463
 464         case IPV6_FL_A_GET:
 465                 if (freq.flr_label & ~IPV6_FLOWLABEL_MASK)
 466                         return -EINVAL;
 467
 468                 fl = fl_create(&freq, optval, optlen, &err);
 469                 if (fl == NULL)
 470                         return err;
 471                 sfl1 = kmalloc(sizeof(*sfl1), GFP_KERNEL);
 472
 473                 if (freq.flr_label) {
 474                         struct ip6_flowlabel *fl1 = NULL;
 475
 476                         err = -EEXIST;
 477                         read_lock_bh(&ip6_sk_fl_lock);
 478                         for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next) {
 479                                 if (sfl->fl->label == freq.flr_label) {
 480                                         if (freq.flr_flags&IPV6_FL_F_EXCL) {
 481                                                 read_unlock_bh(&ip6_sk_fl_lock);
 482                                                 goto done;
 483                                         }
 484                                         fl1 = sfl->fl;
 485                                         atomic_inc(&fl1->users);
 486                                         break;
 487                                 }
 488                         }
 489                         read_unlock_bh(&ip6_sk_fl_lock);
 490
 491                         if (fl1 == NULL)
 492                                 fl1 = fl_lookup(freq.flr_label);
 493                         if (fl1) {
 494                                 err = -EEXIST;
 495                                 if (freq.flr_flags&IPV6_FL_F_EXCL)
 496                                         goto release;
 497                                 err = -EPERM;
 498                                 if (fl1->share == IPV6_FL_S_EXCL ||
 499                                     fl1->share != fl->share ||
 500                                     fl1->owner != fl->owner)
 501                                         goto release;
 502
 503                                 err = -EINVAL;
 504                                 if (!ipv6_addr_equal(&fl1->dst, &fl->dst) ||
 505                                     ipv6_opt_cmp(fl1->opt, fl->opt))
 506                                         goto release;
 507
 508                                 err = -ENOMEM;
 509                                 if (sfl1 == NULL)
 510                                         goto release;
 511                                 if (fl->linger > fl1->linger)
 512                                         fl1->linger = fl->linger;
 513                                 if ((long)(fl->expires - fl1->expires) > 0)
 514                                         fl1->expires = fl->expires;
 515                                 write_lock_bh(&ip6_sk_fl_lock);
 516                                 sfl1->fl = fl1;
 517                                 sfl1->next = np->ipv6_fl_list;
 518                                 np->ipv6_fl_list = sfl1;
 519                                 write_unlock_bh(&ip6_sk_fl_lock);
 520                                 fl_free(fl);
 521                                 return 0;
 522
 523 release:
 524                                 fl_release(fl1);
 525                                 goto done;
 526                         }
 527                 }
 528                 err = -ENOENT;
 529                 if (!(freq.flr_flags&IPV6_FL_F_CREATE))
 530                         goto done;
 531
 532                 err = -ENOMEM;
 533                 if (sfl1 == NULL || (err = mem_check(sk)) != 0)
 534                         goto done;
 535
 536                 err = fl_intern(fl, freq.flr_label);
 537                 if (err)
 538                         goto done;
 539
 540                 if (!freq.flr_label) {
 541                         if (copy_to_user(&((struct in6_flowlabel_req __user *) optval)->flr_label,
 542                                          &fl->label, sizeof(fl->label))) {
 543                                 /* Intentionally ignore fault. */
 544                         }
 545                 }
 546
 547                 sfl1->fl = fl;
 548                 sfl1->next = np->ipv6_fl_list;
 549                 np->ipv6_fl_list = sfl1;
 550                 return 0;
 551
 552         default:
 553                 return -EINVAL;
 554         }
 555
 556 done:
 557         fl_free(fl);
 558         kfree(sfl1);
 559         return err;
 560 }
 561
 562 #ifdef CONFIG_PROC_FS
 563
 564 struct ip6fl_iter_state {
 565         int bucket;
 566 };
 567
 568 #define ip6fl_seq_private(seq)  ((struct ip6fl_iter_state *)(seq)->private)
 569
 570 static struct ip6_flowlabel *ip6fl_get_first(struct seq_file *seq)
 571 {
 572         struct ip6_flowlabel *fl = NULL;
 573         struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 574
 575         for (state->bucket = 0; state->bucket <= FL_HASH_MASK; ++state->bucket) {
 576                 if (fl_ht[state->bucket]) {
 577                         fl = fl_ht[state->bucket];
 578                         break;
 579                 }
 580         }
 581         return fl;
 582 }
 583
 584 static struct ip6_flowlabel *ip6fl_get_next(struct seq_file *seq, struct ip6_flowlabel *fl)
 585 {
 586         struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 587
 588         fl = fl->next;
 589         while (!fl) {
 590                 if (++state->bucket <= FL_HASH_MASK)
 591                         fl = fl_ht[state->bucket];
 592         }
 593         return fl;
 594 }
 595
 596 static struct ip6_flowlabel *ip6fl_get_idx(struct seq_file *seq, loff_t pos)
 597 {
 598         struct ip6_flowlabel *fl = ip6fl_get_first(seq);
 599         if (fl)
 600                 while (pos && (fl = ip6fl_get_next(seq, fl)) != NULL)
 601                         --pos;
 602         return pos ? NULL : fl;
 603 }
 604
 605 static void *ip6fl_seq_start(struct seq_file *seq, loff_t *pos)
 606 {
 607         read_lock_bh(&ip6_fl_lock);
 608         return *pos ? ip6fl_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
 609 }
 610
 611 static void *ip6fl_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 612 {
 613         struct ip6_flowlabel *fl;
 614
 615         if (v == SEQ_START_TOKEN)
 616                 fl = ip6fl_get_first(seq);
 617         else
 618                 fl = ip6fl_get_next(seq, v);
 619         ++*pos;
 620         return fl;
 621 }
 622
 623 static void ip6fl_seq_stop(struct seq_file *seq, void *v)
 624 {
 625         read_unlock_bh(&ip6_fl_lock);
 626 }
 627
 628 static void ip6fl_fl_seq_show(struct seq_file *seq, struct ip6_flowlabel *fl)
 629 {
 630         while(fl) {
 631                 seq_printf(seq,
 632                            "%05X %-1d %-6d %-6d %-6ld %-8ld " NIP6_FMT " %-4d\n",
 633                            (unsigned)ntohl(fl->label),
 634                            fl->share,
 635                            (unsigned)fl->owner,
 636                            atomic_read(&fl->users),
 637                            fl->linger/HZ,
 638                            (long)(fl->expires - jiffies)/HZ,
 639                            NIP6(fl->dst),
 640                            fl->opt ? fl->opt->opt_nflen : 0);
 641                 fl = fl->next;
 642         }
 643 }
 644
 645 static int ip6fl_seq_show(struct seq_file *seq, void *v)
 646 {
 647         if (v == SEQ_START_TOKEN)
 648                 seq_printf(seq, "%-5s %-1s %-6s %-6s %-6s %-8s %-39s %s\n",
 649                            "Label", "S", "Owner", "Users", "Linger", "Expires", "Dst", "Opt");
 650         else
 651                 ip6fl_fl_seq_show(seq, v);
 652         return 0;
 653 }
 654
 655 static struct seq_operations ip6fl_seq_ops = {
 656         .start  =       ip6fl_seq_start,
 657         .next   =       ip6fl_seq_next,
 658         .stop   =       ip6fl_seq_stop,
 659         .show   =       ip6fl_seq_show,
 660 };
 661
 662 static int ip6fl_seq_open(struct inode *inode, struct file *file)
 663 {
 664         struct seq_file *seq;
 665         int rc = -ENOMEM;
 666         struct ip6fl_iter_state *s = kmalloc(sizeof(*s), GFP_KERNEL);
 667
 668         if (!s)
 669                 goto out;
 670
 671         rc = seq_open(file, &ip6fl_seq_ops);
 672         if (rc)
 673                 goto out_kfree;
 674
 675         seq = file->private_data;
 676         seq->private = s;
 677         memset(s, 0, sizeof(*s));
 678 out:
 679         return rc;
 680 out_kfree:
 681         kfree(s);
 682         goto out;
 683 }
 684
 685 static struct file_operations ip6fl_seq_fops = {
 686         .owner          =       THIS_MODULE,
 687         .open           =       ip6fl_seq_open,
 688         .read           =       seq_read,
 689         .llseek         =       seq_lseek,
 690         .release        =       seq_release_private,
 691 };
 692 #endif
 693
 694
 695 void ip6_flowlabel_init(void)
 696 {
 697 #ifdef CONFIG_PROC_FS
 698         proc_net_fops_create("ip6_flowlabel", S_IRUGO, &ip6fl_seq_fops);
 699 #endif
 700 }
 701
 702 void ip6_flowlabel_cleanup(void)
 703 {
 704         del_timer(&ip6_fl_gc_timer);
 705 #ifdef CONFIG_PROC_FS
 706         proc_net_remove("ip6_flowlabel");
 707 #endif
 708 }