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/config.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/sock.h>
  25
  26 #include <net/ipv6.h>
  27 #include <net/ndisc.h>
  28 #include <net/protocol.h>
  29 #include <net/ip6_route.h>
  30 #include <net/addrconf.h>
  31 #include <net/rawv6.h>
  32 #include <net/icmp.h>
  33 #include <net/transp_v6.h>
  34
  35 #include <asm/uaccess.h>
  36
  37 #define FL_MIN_LINGER   6       /* Minimal linger. It is set to 6sec specified
  38                                    in old IPv6 RFC. Well, it was reasonable value.
  39                                  */
  40 #define FL_MAX_LINGER   60      /* Maximal linger timeout */
  41
  42 /* FL hash table */
  43
  44 #define FL_MAX_PER_SOCK 32
  45 #define FL_MAX_SIZE     4096
  46 #define FL_HASH_MASK    255
  47 #define FL_HASH(l)      (ntohl(l)&FL_HASH_MASK)
  48
  49 static atomic_t fl_size = ATOMIC_INIT(0);
  50 static struct ip6_flowlabel *fl_ht[FL_HASH_MASK+1];
  51
  52 static void ip6_fl_gc(unsigned long dummy);
  53 static struct timer_list ip6_fl_gc_timer = TIMER_INITIALIZER(ip6_fl_gc, 0, 0);
  54
  55 /* FL hash table lock: it protects only of GC */
  56
  57 static DEFINE_RWLOCK(ip6_fl_lock);
  58
  59 /* Big socket sock */
  60
  61 static DEFINE_RWLOCK(ip6_sk_fl_lock);
  62
  63
  64 static __inline__ struct ip6_flowlabel * __fl_lookup(u32 label)
  65 {
  66         struct ip6_flowlabel *fl;
  67
  68         for (fl=fl_ht[FL_HASH(label)]; fl; fl = fl->next) {
  69                 if (fl->label == label)
  70                         return fl;
  71         }
  72         return NULL;
  73 }
  74
  75 static struct ip6_flowlabel * fl_lookup(u32 label)
  76 {
  77         struct ip6_flowlabel *fl;
  78
  79         read_lock_bh(&ip6_fl_lock);
  80         fl = __fl_lookup(label);
  81         if (fl)
  82                 atomic_inc(&fl->users);
  83         read_unlock_bh(&ip6_fl_lock);
  84         return fl;
  85 }
  86
  87
  88 static void fl_free(struct ip6_flowlabel *fl)
  89 {
  90         if (fl)
  91                 kfree(fl->opt);
  92         kfree(fl);
  93 }
  94
  95 static void fl_release(struct ip6_flowlabel *fl)
  96 {
  97         write_lock_bh(&ip6_fl_lock);
  98
  99         fl->lastuse = jiffies;
 100         if (atomic_dec_and_test(&fl->users)) {
 101                 unsigned long ttd = fl->lastuse + fl->linger;
 102                 if (time_after(ttd, fl->expires))
 103                         fl->expires = ttd;
 104                 ttd = fl->expires;
 105                 if (fl->opt && fl->share == IPV6_FL_S_EXCL) {
 106                         struct ipv6_txoptions *opt = fl->opt;
 107                         fl->opt = NULL;
 108                         kfree(opt);
 109                 }
 110                 if (!timer_pending(&ip6_fl_gc_timer) ||
 111                     time_after(ip6_fl_gc_timer.expires, ttd))
 112                         mod_timer(&ip6_fl_gc_timer, ttd);
 113         }
 114
 115         write_unlock_bh(&ip6_fl_lock);
 116 }
 117
 118 static void ip6_fl_gc(unsigned long dummy)
 119 {
 120         int i;
 121         unsigned long now = jiffies;
 122         unsigned long sched = 0;
 123
 124         write_lock(&ip6_fl_lock);
 125
 126         for (i=0; i<=FL_HASH_MASK; i++) {
 127                 struct ip6_flowlabel *fl, **flp;
 128                 flp = &fl_ht[i];
 129                 while ((fl=*flp) != NULL) {
 130                         if (atomic_read(&fl->users) == 0) {
 131                                 unsigned long ttd = fl->lastuse + fl->linger;
 132                                 if (time_after(ttd, fl->expires))
 133                                         fl->expires = ttd;
 134                                 ttd = fl->expires;
 135                                 if (time_after_eq(now, ttd)) {
 136                                         *flp = fl->next;
 137                                         fl_free(fl);
 138                                         atomic_dec(&fl_size);
 139                                         continue;
 140                                 }
 141                                 if (!sched || time_before(ttd, sched))
 142                                         sched = ttd;
 143                         }
 144                         flp = &fl->next;
 145                 }
 146         }
 147         if (!sched && atomic_read(&fl_size))
 148                 sched = now + FL_MAX_LINGER;
 149         if (sched) {
 150                 ip6_fl_gc_timer.expires = sched;
 151                 add_timer(&ip6_fl_gc_timer);
 152         }
 153         write_unlock(&ip6_fl_lock);
 154 }
 155
 156 static int fl_intern(struct ip6_flowlabel *fl, __u32 label)
 157 {
 158         fl->label = label & IPV6_FLOWLABEL_MASK;
 159
 160         write_lock_bh(&ip6_fl_lock);
 161         if (label == 0) {
 162                 for (;;) {
 163                         fl->label = htonl(net_random())&IPV6_FLOWLABEL_MASK;
 164                         if (fl->label) {
 165                                 struct ip6_flowlabel *lfl;
 166                                 lfl = __fl_lookup(fl->label);
 167                                 if (lfl == NULL)
 168                                         break;
 169                         }
 170                 }
 171         }
 172
 173         fl->lastuse = jiffies;
 174         fl->next = fl_ht[FL_HASH(fl->label)];
 175         fl_ht[FL_HASH(fl->label)] = fl;
 176         atomic_inc(&fl_size);
 177         write_unlock_bh(&ip6_fl_lock);
 178         return 0;
 179 }
 180
 181
 182
 183 /* Socket flowlabel lists */
 184
 185 struct ip6_flowlabel * fl6_sock_lookup(struct sock *sk, u32 label)
 186 {
 187         struct ipv6_fl_socklist *sfl;
 188         struct ipv6_pinfo *np = inet6_sk(sk);
 189
 190         label &= IPV6_FLOWLABEL_MASK;
 191
 192         for (sfl=np->ipv6_fl_list; sfl; sfl = sfl->next) {
 193                 struct ip6_flowlabel *fl = sfl->fl;
 194                 if (fl->label == label) {
 195                         fl->lastuse = jiffies;
 196                         atomic_inc(&fl->users);
 197                         return fl;
 198                 }
 199         }
 200         return NULL;
 201 }
 202
 203 void fl6_free_socklist(struct sock *sk)
 204 {
 205         struct ipv6_pinfo *np = inet6_sk(sk);
 206         struct ipv6_fl_socklist *sfl;
 207
 208         while ((sfl = np->ipv6_fl_list) != NULL) {
 209                 np->ipv6_fl_list = sfl->next;
 210                 fl_release(sfl->fl);
 211                 kfree(sfl);
 212         }
 213 }
 214
 215 /* Service routines */
 216
 217
 218 /*
 219    It is the only difficult place. flowlabel enforces equal headers
 220    before and including routing header, however user may supply options
 221    following rthdr.
 222  */
 223
 224 struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions * opt_space,
 225                                          struct ip6_flowlabel * fl,
 226                                          struct ipv6_txoptions * fopt)
 227 {
 228         struct ipv6_txoptions * fl_opt = fl->opt;
 229
 230         if (fopt == NULL || fopt->opt_flen == 0)
 231                 return fl_opt;
 232
 233         if (fl_opt != NULL) {
 234                 opt_space->hopopt = fl_opt->hopopt;
 235                 opt_space->dst0opt = fl_opt->dst0opt;
 236                 opt_space->srcrt = fl_opt->srcrt;
 237                 opt_space->opt_nflen = fl_opt->opt_nflen;
 238         } else {
 239                 if (fopt->opt_nflen == 0)
 240                         return fopt;
 241                 opt_space->hopopt = NULL;
 242                 opt_space->dst0opt = NULL;
 243                 opt_space->srcrt = NULL;
 244                 opt_space->opt_nflen = 0;
 245         }
 246         opt_space->dst1opt = fopt->dst1opt;
 247         opt_space->auth = fopt->auth;
 248         opt_space->opt_flen = fopt->opt_flen;
 249         return opt_space;
 250 }
 251
 252 static unsigned long check_linger(unsigned long ttl)
 253 {
 254         if (ttl < FL_MIN_LINGER)
 255                 return FL_MIN_LINGER*HZ;
 256         if (ttl > FL_MAX_LINGER && !capable(CAP_NET_ADMIN))
 257                 return 0;
 258         return ttl*HZ;
 259 }
 260
 261 static int fl6_renew(struct ip6_flowlabel *fl, unsigned long linger, unsigned long expires)
 262 {
 263         linger = check_linger(linger);
 264         if (!linger)
 265                 return -EPERM;
 266         expires = check_linger(expires);
 267         if (!expires)
 268                 return -EPERM;
 269         fl->lastuse = jiffies;
 270         if (time_before(fl->linger, linger))
 271                 fl->linger = linger;
 272         if (time_before(expires, fl->linger))
 273                 expires = fl->linger;
 274         if (time_before(fl->expires, fl->lastuse + expires))
 275                 fl->expires = fl->lastuse + expires;
 276         return 0;
 277 }
 278
 279 static struct ip6_flowlabel *
 280 fl_create(struct in6_flowlabel_req *freq, char __user *optval, int optlen, int *err_p)
 281 {
 282         struct ip6_flowlabel *fl;
 283         int olen;
 284         int addr_type;
 285         int err;
 286
 287         err = -ENOMEM;
 288         fl = kmalloc(sizeof(*fl), GFP_KERNEL);
 289         if (fl == NULL)
 290                 goto done;
 291         memset(fl, 0, sizeof(*fl));
 292
 293         olen = optlen - CMSG_ALIGN(sizeof(*freq));
 294         if (olen > 0) {
 295                 struct msghdr msg;
 296                 struct flowi flowi;
 297                 int junk;
 298
 299                 err = -ENOMEM;
 300                 fl->opt = kmalloc(sizeof(*fl->opt) + olen, GFP_KERNEL);
 301                 if (fl->opt == NULL)
 302                         goto done;
 303
 304                 memset(fl->opt, 0, sizeof(*fl->opt));
 305                 fl->opt->tot_len = sizeof(*fl->opt) + olen;
 306                 err = -EFAULT;
 307                 if (copy_from_user(fl->opt+1, optval+CMSG_ALIGN(sizeof(*freq)), olen))
 308                         goto done;
 309
 310                 msg.msg_controllen = olen;
 311                 msg.msg_control = (void*)(fl->opt+1);
 312                 flowi.oif = 0;
 313
 314                 err = datagram_send_ctl(&msg, &flowi, fl->opt, &junk);
 315                 if (err)
 316                         goto done;
 317                 err = -EINVAL;
 318                 if (fl->opt->opt_flen)
 319                         goto done;
 320                 if (fl->opt->opt_nflen == 0) {
 321                         kfree(fl->opt);
 322                         fl->opt = NULL;
 323                 }
 324         }
 325
 326         fl->expires = jiffies;
 327         err = fl6_renew(fl, freq->flr_linger, freq->flr_expires);
 328         if (err)
 329                 goto done;
 330         fl->share = freq->flr_share;
 331         addr_type = ipv6_addr_type(&freq->flr_dst);
 332         if ((addr_type&IPV6_ADDR_MAPPED)
 333             || addr_type == IPV6_ADDR_ANY)
 334                 goto done;
 335         ipv6_addr_copy(&fl->dst, &freq->flr_dst);
 336         atomic_set(&fl->users, 1);
 337         switch (fl->share) {
 338         case IPV6_FL_S_EXCL:
 339         case IPV6_FL_S_ANY:
 340                 break;
 341         case IPV6_FL_S_PROCESS:
 342                 fl->owner = current->pid;
 343                 break;
 344         case IPV6_FL_S_USER:
 345                 fl->owner = current->euid;
 346                 break;
 347         default:
 348                 err = -EINVAL;
 349                 goto done;
 350         }
 351         return fl;
 352
 353 done:
 354         fl_free(fl);
 355         *err_p = err;
 356         return NULL;
 357 }
 358
 359 static int mem_check(struct sock *sk)
 360 {
 361         struct ipv6_pinfo *np = inet6_sk(sk);
 362         struct ipv6_fl_socklist *sfl;
 363         int room = FL_MAX_SIZE - atomic_read(&fl_size);
 364         int count = 0;
 365
 366         if (room > FL_MAX_SIZE - FL_MAX_PER_SOCK)
 367                 return 0;
 368
 369         for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next)
 370                 count++;
 371
 372         if (room <= 0 ||
 373             ((count >= FL_MAX_PER_SOCK ||
 374              (count > 0 && room < FL_MAX_SIZE/2) || room < FL_MAX_SIZE/4)
 375              && !capable(CAP_NET_ADMIN)))
 376                 return -ENOBUFS;
 377
 378         return 0;
 379 }
 380
 381 static int ipv6_hdr_cmp(struct ipv6_opt_hdr *h1, struct ipv6_opt_hdr *h2)
 382 {
 383         if (h1 == h2)
 384                 return 0;
 385         if (h1 == NULL || h2 == NULL)
 386                 return 1;
 387         if (h1->hdrlen != h2->hdrlen)
 388                 return 1;
 389         return memcmp(h1+1, h2+1, ((h1->hdrlen+1)<<3) - sizeof(*h1));
 390 }
 391
 392 static int ipv6_opt_cmp(struct ipv6_txoptions *o1, struct ipv6_txoptions *o2)
 393 {
 394         if (o1 == o2)
 395                 return 0;
 396         if (o1 == NULL || o2 == NULL)
 397                 return 1;
 398         if (o1->opt_nflen != o2->opt_nflen)
 399                 return 1;
 400         if (ipv6_hdr_cmp(o1->hopopt, o2->hopopt))
 401                 return 1;
 402         if (ipv6_hdr_cmp(o1->dst0opt, o2->dst0opt))
 403                 return 1;
 404         if (ipv6_hdr_cmp((struct ipv6_opt_hdr *)o1->srcrt, (struct ipv6_opt_hdr *)o2->srcrt))
 405                 return 1;
 406         return 0;
 407 }
 408
 409 int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen)
 410 {
 411         int err;
 412         struct ipv6_pinfo *np = inet6_sk(sk);
 413         struct in6_flowlabel_req freq;
 414         struct ipv6_fl_socklist *sfl1=NULL;
 415         struct ipv6_fl_socklist *sfl, **sflp;
 416         struct ip6_flowlabel *fl;
 417
 418         if (optlen < sizeof(freq))
 419                 return -EINVAL;
 420
 421         if (copy_from_user(&freq, optval, sizeof(freq)))
 422                 return -EFAULT;
 423
 424         switch (freq.flr_action) {
 425         case IPV6_FL_A_PUT:
 426                 write_lock_bh(&ip6_sk_fl_lock);
 427                 for (sflp = &np->ipv6_fl_list; (sfl=*sflp)!=NULL; sflp = &sfl->next) {
 428                         if (sfl->fl->label == freq.flr_label) {
 429                                 if (freq.flr_label == (np->flow_label&IPV6_FLOWLABEL_MASK))
 430                                         np->flow_label &= ~IPV6_FLOWLABEL_MASK;
 431                                 *sflp = sfl->next;
 432                                 write_unlock_bh(&ip6_sk_fl_lock);
 433                                 fl_release(sfl->fl);
 434                                 kfree(sfl);
 435                                 return 0;
 436                         }
 437                 }
 438                 write_unlock_bh(&ip6_sk_fl_lock);
 439                 return -ESRCH;
 440
 441         case IPV6_FL_A_RENEW:
 442                 read_lock_bh(&ip6_sk_fl_lock);
 443                 for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next) {
 444                         if (sfl->fl->label == freq.flr_label) {
 445                                 err = fl6_renew(sfl->fl, freq.flr_linger, freq.flr_expires);
 446                                 read_unlock_bh(&ip6_sk_fl_lock);
 447                                 return err;
 448                         }
 449                 }
 450                 read_unlock_bh(&ip6_sk_fl_lock);
 451
 452                 if (freq.flr_share == IPV6_FL_S_NONE && capable(CAP_NET_ADMIN)) {
 453                         fl = fl_lookup(freq.flr_label);
 454                         if (fl) {
 455                                 err = fl6_renew(fl, freq.flr_linger, freq.flr_expires);
 456                                 fl_release(fl);
 457                                 return err;
 458                         }
 459                 }
 460                 return -ESRCH;
 461
 462         case IPV6_FL_A_GET:
 463                 if (freq.flr_label & ~IPV6_FLOWLABEL_MASK)
 464                         return -EINVAL;
 465
 466                 fl = fl_create(&freq, optval, optlen, &err);
 467                 if (fl == NULL)
 468                         return err;
 469                 sfl1 = kmalloc(sizeof(*sfl1), GFP_KERNEL);
 470
 471                 if (freq.flr_label) {
 472                         struct ip6_flowlabel *fl1 = NULL;
 473
 474                         err = -EEXIST;
 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                                         if (freq.flr_flags&IPV6_FL_F_EXCL) {
 479                                                 read_unlock_bh(&ip6_sk_fl_lock);
 480                                                 goto done;
 481                                         }
 482                                         fl1 = sfl->fl;
 483                                         atomic_inc(&fl->users);
 484                                         break;
 485                                 }
 486                         }
 487                         read_unlock_bh(&ip6_sk_fl_lock);
 488
 489                         if (fl1 == NULL)
 490                                 fl1 = fl_lookup(freq.flr_label);
 491                         if (fl1) {
 492                                 err = -EEXIST;
 493                                 if (freq.flr_flags&IPV6_FL_F_EXCL)
 494                                         goto release;
 495                                 err = -EPERM;
 496                                 if (fl1->share == IPV6_FL_S_EXCL ||
 497                                     fl1->share != fl->share ||
 498                                     fl1->owner != fl->owner)
 499                                         goto release;
 500
 501                                 err = -EINVAL;
 502                                 if (!ipv6_addr_equal(&fl1->dst, &fl->dst) ||
 503                                     ipv6_opt_cmp(fl1->opt, fl->opt))
 504                                         goto release;
 505
 506                                 err = -ENOMEM;
 507                                 if (sfl1 == NULL)
 508                                         goto release;
 509                                 if (fl->linger > fl1->linger)
 510                                         fl1->linger = fl->linger;
 511                                 if ((long)(fl->expires - fl1->expires) > 0)
 512                                         fl1->expires = fl->expires;
 513                                 write_lock_bh(&ip6_sk_fl_lock);
 514                                 sfl1->fl = fl1;
 515                                 sfl1->next = np->ipv6_fl_list;
 516                                 np->ipv6_fl_list = sfl1;
 517                                 write_unlock_bh(&ip6_sk_fl_lock);
 518                                 fl_free(fl);
 519                                 return 0;
 520
 521 release:
 522                                 fl_release(fl1);
 523                                 goto done;
 524                         }
 525                 }
 526                 err = -ENOENT;
 527                 if (!(freq.flr_flags&IPV6_FL_F_CREATE))
 528                         goto done;
 529
 530                 err = -ENOMEM;
 531                 if (sfl1 == NULL || (err = mem_check(sk)) != 0)
 532                         goto done;
 533
 534                 err = fl_intern(fl, freq.flr_label);
 535                 if (err)
 536                         goto done;
 537
 538                 if (!freq.flr_label) {
 539                         if (copy_to_user(&((struct in6_flowlabel_req __user *) optval)->flr_label,
 540                                          &fl->label, sizeof(fl->label))) {
 541                                 /* Intentionally ignore fault. */
 542                         }
 543                 }
 544
 545                 sfl1->fl = fl;
 546                 sfl1->next = np->ipv6_fl_list;
 547                 np->ipv6_fl_list = sfl1;
 548                 return 0;
 549
 550         default:
 551                 return -EINVAL;
 552         }
 553
 554 done:
 555         fl_free(fl);
 556         kfree(sfl1);
 557         return err;
 558 }
 559
 560 #ifdef CONFIG_PROC_FS
 561
 562 struct ip6fl_iter_state {
 563         int bucket;
 564 };
 565
 566 #define ip6fl_seq_private(seq)  ((struct ip6fl_iter_state *)(seq)->private)
 567
 568 static struct ip6_flowlabel *ip6fl_get_first(struct seq_file *seq)
 569 {
 570         struct ip6_flowlabel *fl = NULL;
 571         struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 572
 573         for (state->bucket = 0; state->bucket <= FL_HASH_MASK; ++state->bucket) {
 574                 if (fl_ht[state->bucket]) {
 575                         fl = fl_ht[state->bucket];
 576                         break;
 577                 }
 578         }
 579         return fl;
 580 }
 581
 582 static struct ip6_flowlabel *ip6fl_get_next(struct seq_file *seq, struct ip6_flowlabel *fl)
 583 {
 584         struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 585
 586         fl = fl->next;
 587         while (!fl) {
 588                 if (++state->bucket <= FL_HASH_MASK)
 589                         fl = fl_ht[state->bucket];
 590         }
 591         return fl;
 592 }
 593
 594 static struct ip6_flowlabel *ip6fl_get_idx(struct seq_file *seq, loff_t pos)
 595 {
 596         struct ip6_flowlabel *fl = ip6fl_get_first(seq);
 597         if (fl)
 598                 while (pos && (fl = ip6fl_get_next(seq, fl)) != NULL)
 599                         --pos;
 600         return pos ? NULL : fl;
 601 }
 602
 603 static void *ip6fl_seq_start(struct seq_file *seq, loff_t *pos)
 604 {
 605         read_lock_bh(&ip6_fl_lock);
 606         return *pos ? ip6fl_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
 607 }
 608
 609 static void *ip6fl_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 610 {
 611         struct ip6_flowlabel *fl;
 612
 613         if (v == SEQ_START_TOKEN)
 614                 fl = ip6fl_get_first(seq);
 615         else
 616                 fl = ip6fl_get_next(seq, v);
 617         ++*pos;
 618         return fl;
 619 }
 620
 621 static void ip6fl_seq_stop(struct seq_file *seq, void *v)
 622 {
 623         read_unlock_bh(&ip6_fl_lock);
 624 }
 625
 626 static void ip6fl_fl_seq_show(struct seq_file *seq, struct ip6_flowlabel *fl)
 627 {
 628         while(fl) {
 629                 seq_printf(seq,
 630                            "%05X %-1d %-6d %-6d %-6ld %-8ld "
 631                            "%02x%02x%02x%02x%02x%02x%02x%02x "
 632                            "%-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_puts(seq, "Label S Owner  Users  Linger Expires  "
 649                               "Dst                              Opt\n");
 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 }