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 #include <linux/slab.h>
  24 #include <linux/export.h>
  25
  26 #include <net/net_namespace.h>
  27 #include <net/sock.h>
  28
  29 #include <net/ipv6.h>
  30 #include <net/ndisc.h>
  31 #include <net/protocol.h>
  32 #include <net/ip6_route.h>
  33 #include <net/addrconf.h>
  34 #include <net/rawv6.h>
  35 #include <net/icmp.h>
  36 #include <net/transp_v6.h>
  37
  38 #include <asm/uaccess.h>
  39
  40 #define FL_MIN_LINGER   6       /* Minimal linger. It is set to 6sec specified
  41                                    in old IPv6 RFC. Well, it was reasonable value.
  42                                  */
  43 #define FL_MAX_LINGER   60      /* Maximal linger timeout */
  44
  45 /* FL hash table */
  46
  47 #define FL_MAX_PER_SOCK 32
  48 #define FL_MAX_SIZE     4096
  49 #define FL_HASH_MASK    255
  50 #define FL_HASH(l)      (ntohl(l)&FL_HASH_MASK)
  51
  52 static atomic_t fl_size = ATOMIC_INIT(0);
  53 static struct ip6_flowlabel *fl_ht[FL_HASH_MASK+1];
  54
  55 static void ip6_fl_gc(unsigned long dummy);
  56 static DEFINE_TIMER(ip6_fl_gc_timer, ip6_fl_gc, 0, 0);
  57
  58 /* FL hash table lock: it protects only of GC */
  59
  60 static DEFINE_RWLOCK(ip6_fl_lock);
  61
  62 /* Big socket sock */
  63
  64 static DEFINE_RWLOCK(ip6_sk_fl_lock);
  65
  66
  67 static inline struct ip6_flowlabel *__fl_lookup(struct net *net, __be32 label)
  68 {
  69         struct ip6_flowlabel *fl;
  70
  71         for (fl=fl_ht[FL_HASH(label)]; fl; fl = fl->next) {
  72                 if (fl->label == label && net_eq(fl->fl_net, net))
  73                         return fl;
  74         }
  75         return NULL;
  76 }
  77
  78 static struct ip6_flowlabel *fl_lookup(struct net *net, __be32 label)
  79 {
  80         struct ip6_flowlabel *fl;
  81
  82         read_lock_bh(&ip6_fl_lock);
  83         fl = __fl_lookup(net, label);
  84         if (fl)
  85                 atomic_inc(&fl->users);
  86         read_unlock_bh(&ip6_fl_lock);
  87         return fl;
  88 }
  89
  90
  91 static void fl_free(struct ip6_flowlabel *fl)
  92 {
  93         if (fl) {
  94                 release_net(fl->fl_net);
  95                 kfree(fl->opt);
  96         }
  97         kfree(fl);
  98 }
  99
 100 static void fl_release(struct ip6_flowlabel *fl)
 101 {
 102         write_lock_bh(&ip6_fl_lock);
 103
 104         fl->lastuse = jiffies;
 105         if (atomic_dec_and_test(&fl->users)) {
 106                 unsigned long ttd = fl->lastuse + fl->linger;
 107                 if (time_after(ttd, fl->expires))
 108                         fl->expires = ttd;
 109                 ttd = fl->expires;
 110                 if (fl->opt && fl->share == IPV6_FL_S_EXCL) {
 111                         struct ipv6_txoptions *opt = fl->opt;
 112                         fl->opt = NULL;
 113                         kfree(opt);
 114                 }
 115                 if (!timer_pending(&ip6_fl_gc_timer) ||
 116                     time_after(ip6_fl_gc_timer.expires, ttd))
 117                         mod_timer(&ip6_fl_gc_timer, ttd);
 118         }
 119         write_unlock_bh(&ip6_fl_lock);
 120 }
 121
 122 static void ip6_fl_gc(unsigned long dummy)
 123 {
 124         int i;
 125         unsigned long now = jiffies;
 126         unsigned long sched = 0;
 127
 128         write_lock(&ip6_fl_lock);
 129
 130         for (i=0; i<=FL_HASH_MASK; i++) {
 131                 struct ip6_flowlabel *fl, **flp;
 132                 flp = &fl_ht[i];
 133                 while ((fl=*flp) != NULL) {
 134                         if (atomic_read(&fl->users) == 0) {
 135                                 unsigned long ttd = fl->lastuse + fl->linger;
 136                                 if (time_after(ttd, fl->expires))
 137                                         fl->expires = ttd;
 138                                 ttd = fl->expires;
 139                                 if (time_after_eq(now, ttd)) {
 140                                         *flp = fl->next;
 141                                         fl_free(fl);
 142                                         atomic_dec(&fl_size);
 143                                         continue;
 144                                 }
 145                                 if (!sched || time_before(ttd, sched))
 146                                         sched = ttd;
 147                         }
 148                         flp = &fl->next;
 149                 }
 150         }
 151         if (!sched && atomic_read(&fl_size))
 152                 sched = now + FL_MAX_LINGER;
 153         if (sched) {
 154                 mod_timer(&ip6_fl_gc_timer, sched);
 155         }
 156         write_unlock(&ip6_fl_lock);
 157 }
 158
 159 static void __net_exit ip6_fl_purge(struct net *net)
 160 {
 161         int i;
 162
 163         write_lock(&ip6_fl_lock);
 164         for (i = 0; i <= FL_HASH_MASK; i++) {
 165                 struct ip6_flowlabel *fl, **flp;
 166                 flp = &fl_ht[i];
 167                 while ((fl = *flp) != NULL) {
 168                         if (net_eq(fl->fl_net, net) &&
 169                             atomic_read(&fl->users) == 0) {
 170                                 *flp = fl->next;
 171                                 fl_free(fl);
 172                                 atomic_dec(&fl_size);
 173                                 continue;
 174                         }
 175                         flp = &fl->next;
 176                 }
 177         }
 178         write_unlock(&ip6_fl_lock);
 179 }
 180
 181 static struct ip6_flowlabel *fl_intern(struct net *net,
 182                                        struct ip6_flowlabel *fl, __be32 label)
 183 {
 184         struct ip6_flowlabel *lfl;
 185
 186         fl->label = label & IPV6_FLOWLABEL_MASK;
 187
 188         write_lock_bh(&ip6_fl_lock);
 189         if (label == 0) {
 190                 for (;;) {
 191                         fl->label = htonl(net_random())&IPV6_FLOWLABEL_MASK;
 192                         if (fl->label) {
 193                                 lfl = __fl_lookup(net, fl->label);
 194                                 if (lfl == NULL)
 195                                         break;
 196                         }
 197                 }
 198         } else {
 199                 /*
 200                  * we dropper the ip6_fl_lock, so this entry could reappear
 201                  * and we need to recheck with it.
 202                  *
 203                  * OTOH no need to search the active socket first, like it is
 204                  * done in ipv6_flowlabel_opt - sock is locked, so new entry
 205                  * with the same label can only appear on another sock
 206                  */
 207                 lfl = __fl_lookup(net, fl->label);
 208                 if (lfl != NULL) {
 209                         atomic_inc(&lfl->users);
 210                         write_unlock_bh(&ip6_fl_lock);
 211                         return lfl;
 212                 }
 213         }
 214
 215         fl->lastuse = jiffies;
 216         fl->next = fl_ht[FL_HASH(fl->label)];
 217         fl_ht[FL_HASH(fl->label)] = fl;
 218         atomic_inc(&fl_size);
 219         write_unlock_bh(&ip6_fl_lock);
 220         return NULL;
 221 }
 222
 223
 224
 225 /* Socket flowlabel lists */
 226
 227 struct ip6_flowlabel * fl6_sock_lookup(struct sock *sk, __be32 label)
 228 {
 229         struct ipv6_fl_socklist *sfl;
 230         struct ipv6_pinfo *np = inet6_sk(sk);
 231
 232         label &= IPV6_FLOWLABEL_MASK;
 233
 234         read_lock_bh(&ip6_sk_fl_lock);
 235         for (sfl=np->ipv6_fl_list; sfl; sfl = sfl->next) {
 236                 struct ip6_flowlabel *fl = sfl->fl;
 237                 if (fl->label == label) {
 238                         fl->lastuse = jiffies;
 239                         atomic_inc(&fl->users);
 240                         read_unlock_bh(&ip6_sk_fl_lock);
 241                         return fl;
 242                 }
 243         }
 244         read_unlock_bh(&ip6_sk_fl_lock);
 245         return NULL;
 246 }
 247
 248 EXPORT_SYMBOL_GPL(fl6_sock_lookup);
 249
 250 void fl6_free_socklist(struct sock *sk)
 251 {
 252         struct ipv6_pinfo *np = inet6_sk(sk);
 253         struct ipv6_fl_socklist *sfl;
 254
 255         while ((sfl = np->ipv6_fl_list) != NULL) {
 256                 np->ipv6_fl_list = sfl->next;
 257                 fl_release(sfl->fl);
 258                 kfree(sfl);
 259         }
 260 }
 261
 262 /* Service routines */
 263
 264
 265 /*
 266    It is the only difficult place. flowlabel enforces equal headers
 267    before and including routing header, however user may supply options
 268    following rthdr.
 269  */
 270
 271 struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions * opt_space,
 272                                          struct ip6_flowlabel * fl,
 273                                          struct ipv6_txoptions * fopt)
 274 {
 275         struct ipv6_txoptions * fl_opt = fl->opt;
 276
 277         if (fopt == NULL || fopt->opt_flen == 0)
 278                 return fl_opt;
 279
 280         if (fl_opt != NULL) {
 281                 opt_space->hopopt = fl_opt->hopopt;
 282                 opt_space->dst0opt = fl_opt->dst0opt;
 283                 opt_space->srcrt = fl_opt->srcrt;
 284                 opt_space->opt_nflen = fl_opt->opt_nflen;
 285         } else {
 286                 if (fopt->opt_nflen == 0)
 287                         return fopt;
 288                 opt_space->hopopt = NULL;
 289                 opt_space->dst0opt = NULL;
 290                 opt_space->srcrt = NULL;
 291                 opt_space->opt_nflen = 0;
 292         }
 293         opt_space->dst1opt = fopt->dst1opt;
 294         opt_space->opt_flen = fopt->opt_flen;
 295         return opt_space;
 296 }
 297 EXPORT_SYMBOL_GPL(fl6_merge_options);
 298
 299 static unsigned long check_linger(unsigned long ttl)
 300 {
 301         if (ttl < FL_MIN_LINGER)
 302                 return FL_MIN_LINGER*HZ;
 303         if (ttl > FL_MAX_LINGER && !capable(CAP_NET_ADMIN))
 304                 return 0;
 305         return ttl*HZ;
 306 }
 307
 308 static int fl6_renew(struct ip6_flowlabel *fl, unsigned long linger, unsigned long expires)
 309 {
 310         linger = check_linger(linger);
 311         if (!linger)
 312                 return -EPERM;
 313         expires = check_linger(expires);
 314         if (!expires)
 315                 return -EPERM;
 316         fl->lastuse = jiffies;
 317         if (time_before(fl->linger, linger))
 318                 fl->linger = linger;
 319         if (time_before(expires, fl->linger))
 320                 expires = fl->linger;
 321         if (time_before(fl->expires, fl->lastuse + expires))
 322                 fl->expires = fl->lastuse + expires;
 323         return 0;
 324 }
 325
 326 static struct ip6_flowlabel *
 327 fl_create(struct net *net, struct sock *sk, struct in6_flowlabel_req *freq,
 328           char __user *optval, int optlen, int *err_p)
 329 {
 330         struct ip6_flowlabel *fl = NULL;
 331         int olen;
 332         int addr_type;
 333         int err;
 334
 335         olen = optlen - CMSG_ALIGN(sizeof(*freq));
 336         err = -EINVAL;
 337         if (olen > 64 * 1024)
 338                 goto done;
 339
 340         err = -ENOMEM;
 341         fl = kzalloc(sizeof(*fl), GFP_KERNEL);
 342         if (fl == NULL)
 343                 goto done;
 344
 345         if (olen > 0) {
 346                 struct msghdr msg;
 347                 struct flowi6 flowi6;
 348                 int junk;
 349
 350                 err = -ENOMEM;
 351                 fl->opt = kmalloc(sizeof(*fl->opt) + olen, GFP_KERNEL);
 352                 if (fl->opt == NULL)
 353                         goto done;
 354
 355                 memset(fl->opt, 0, sizeof(*fl->opt));
 356                 fl->opt->tot_len = sizeof(*fl->opt) + olen;
 357                 err = -EFAULT;
 358                 if (copy_from_user(fl->opt+1, optval+CMSG_ALIGN(sizeof(*freq)), olen))
 359                         goto done;
 360
 361                 msg.msg_controllen = olen;
 362                 msg.msg_control = (void*)(fl->opt+1);
 363                 memset(&flowi6, 0, sizeof(flowi6));
 364
 365                 err = datagram_send_ctl(net, sk, &msg, &flowi6, fl->opt, &junk,
 366                                         &junk, &junk);
 367                 if (err)
 368                         goto done;
 369                 err = -EINVAL;
 370                 if (fl->opt->opt_flen)
 371                         goto done;
 372                 if (fl->opt->opt_nflen == 0) {
 373                         kfree(fl->opt);
 374                         fl->opt = NULL;
 375                 }
 376         }
 377
 378         fl->fl_net = hold_net(net);
 379         fl->expires = jiffies;
 380         err = fl6_renew(fl, freq->flr_linger, freq->flr_expires);
 381         if (err)
 382                 goto done;
 383         fl->share = freq->flr_share;
 384         addr_type = ipv6_addr_type(&freq->flr_dst);
 385         if ((addr_type & IPV6_ADDR_MAPPED) ||
 386             addr_type == IPV6_ADDR_ANY) {
 387                 err = -EINVAL;
 388                 goto done;
 389         }
 390         fl->dst = freq->flr_dst;
 391         atomic_set(&fl->users, 1);
 392         switch (fl->share) {
 393         case IPV6_FL_S_EXCL:
 394         case IPV6_FL_S_ANY:
 395                 break;
 396         case IPV6_FL_S_PROCESS:
 397                 fl->owner = current->pid;
 398                 break;
 399         case IPV6_FL_S_USER:
 400                 fl->owner = current_euid();
 401                 break;
 402         default:
 403                 err = -EINVAL;
 404                 goto done;
 405         }
 406         return fl;
 407
 408 done:
 409         fl_free(fl);
 410         *err_p = err;
 411         return NULL;
 412 }
 413
 414 static int mem_check(struct sock *sk)
 415 {
 416         struct ipv6_pinfo *np = inet6_sk(sk);
 417         struct ipv6_fl_socklist *sfl;
 418         int room = FL_MAX_SIZE - atomic_read(&fl_size);
 419         int count = 0;
 420
 421         if (room > FL_MAX_SIZE - FL_MAX_PER_SOCK)
 422                 return 0;
 423
 424         for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next)
 425                 count++;
 426
 427         if (room <= 0 ||
 428             ((count >= FL_MAX_PER_SOCK ||
 429               (count > 0 && room < FL_MAX_SIZE/2) || room < FL_MAX_SIZE/4) &&
 430              !capable(CAP_NET_ADMIN)))
 431                 return -ENOBUFS;
 432
 433         return 0;
 434 }
 435
 436 static bool ipv6_hdr_cmp(struct ipv6_opt_hdr *h1, struct ipv6_opt_hdr *h2)
 437 {
 438         if (h1 == h2)
 439                 return false;
 440         if (h1 == NULL || h2 == NULL)
 441                 return true;
 442         if (h1->hdrlen != h2->hdrlen)
 443                 return true;
 444         return memcmp(h1+1, h2+1, ((h1->hdrlen+1)<<3) - sizeof(*h1));
 445 }
 446
 447 static bool ipv6_opt_cmp(struct ipv6_txoptions *o1, struct ipv6_txoptions *o2)
 448 {
 449         if (o1 == o2)
 450                 return false;
 451         if (o1 == NULL || o2 == NULL)
 452                 return true;
 453         if (o1->opt_nflen != o2->opt_nflen)
 454                 return true;
 455         if (ipv6_hdr_cmp(o1->hopopt, o2->hopopt))
 456                 return true;
 457         if (ipv6_hdr_cmp(o1->dst0opt, o2->dst0opt))
 458                 return true;
 459         if (ipv6_hdr_cmp((struct ipv6_opt_hdr *)o1->srcrt, (struct ipv6_opt_hdr *)o2->srcrt))
 460                 return true;
 461         return false;
 462 }
 463
 464 static inline void fl_link(struct ipv6_pinfo *np, struct ipv6_fl_socklist *sfl,
 465                 struct ip6_flowlabel *fl)
 466 {
 467         write_lock_bh(&ip6_sk_fl_lock);
 468         sfl->fl = fl;
 469         sfl->next = np->ipv6_fl_list;
 470         np->ipv6_fl_list = sfl;
 471         write_unlock_bh(&ip6_sk_fl_lock);
 472 }
 473
 474 int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen)
 475 {
 476         int uninitialized_var(err);
 477         struct net *net = sock_net(sk);
 478         struct ipv6_pinfo *np = inet6_sk(sk);
 479         struct in6_flowlabel_req freq;
 480         struct ipv6_fl_socklist *sfl1=NULL;
 481         struct ipv6_fl_socklist *sfl, **sflp;
 482         struct ip6_flowlabel *fl, *fl1 = NULL;
 483
 484
 485         if (optlen < sizeof(freq))
 486                 return -EINVAL;
 487
 488         if (copy_from_user(&freq, optval, sizeof(freq)))
 489                 return -EFAULT;
 490
 491         switch (freq.flr_action) {
 492         case IPV6_FL_A_PUT:
 493                 write_lock_bh(&ip6_sk_fl_lock);
 494                 for (sflp = &np->ipv6_fl_list; (sfl=*sflp)!=NULL; sflp = &sfl->next) {
 495                         if (sfl->fl->label == freq.flr_label) {
 496                                 if (freq.flr_label == (np->flow_label&IPV6_FLOWLABEL_MASK))
 497                                         np->flow_label &= ~IPV6_FLOWLABEL_MASK;
 498                                 *sflp = sfl->next;
 499                                 write_unlock_bh(&ip6_sk_fl_lock);
 500                                 fl_release(sfl->fl);
 501                                 kfree(sfl);
 502                                 return 0;
 503                         }
 504                 }
 505                 write_unlock_bh(&ip6_sk_fl_lock);
 506                 return -ESRCH;
 507
 508         case IPV6_FL_A_RENEW:
 509                 read_lock_bh(&ip6_sk_fl_lock);
 510                 for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next) {
 511                         if (sfl->fl->label == freq.flr_label) {
 512                                 err = fl6_renew(sfl->fl, freq.flr_linger, freq.flr_expires);
 513                                 read_unlock_bh(&ip6_sk_fl_lock);
 514                                 return err;
 515                         }
 516                 }
 517                 read_unlock_bh(&ip6_sk_fl_lock);
 518
 519                 if (freq.flr_share == IPV6_FL_S_NONE && capable(CAP_NET_ADMIN)) {
 520                         fl = fl_lookup(net, freq.flr_label);
 521                         if (fl) {
 522                                 err = fl6_renew(fl, freq.flr_linger, freq.flr_expires);
 523                                 fl_release(fl);
 524                                 return err;
 525                         }
 526                 }
 527                 return -ESRCH;
 528
 529         case IPV6_FL_A_GET:
 530                 if (freq.flr_label & ~IPV6_FLOWLABEL_MASK)
 531                         return -EINVAL;
 532
 533                 fl = fl_create(net, sk, &freq, optval, optlen, &err);
 534                 if (fl == NULL)
 535                         return err;
 536                 sfl1 = kmalloc(sizeof(*sfl1), GFP_KERNEL);
 537
 538                 if (freq.flr_label) {
 539                         err = -EEXIST;
 540                         read_lock_bh(&ip6_sk_fl_lock);
 541                         for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next) {
 542                                 if (sfl->fl->label == freq.flr_label) {
 543                                         if (freq.flr_flags&IPV6_FL_F_EXCL) {
 544                                                 read_unlock_bh(&ip6_sk_fl_lock);
 545                                                 goto done;
 546                                         }
 547                                         fl1 = sfl->fl;
 548                                         atomic_inc(&fl1->users);
 549                                         break;
 550                                 }
 551                         }
 552                         read_unlock_bh(&ip6_sk_fl_lock);
 553
 554                         if (fl1 == NULL)
 555                                 fl1 = fl_lookup(net, freq.flr_label);
 556                         if (fl1) {
 557 recheck:
 558                                 err = -EEXIST;
 559                                 if (freq.flr_flags&IPV6_FL_F_EXCL)
 560                                         goto release;
 561                                 err = -EPERM;
 562                                 if (fl1->share == IPV6_FL_S_EXCL ||
 563                                     fl1->share != fl->share ||
 564                                     fl1->owner != fl->owner)
 565                                         goto release;
 566
 567                                 err = -EINVAL;
 568                                 if (!ipv6_addr_equal(&fl1->dst, &fl->dst) ||
 569                                     ipv6_opt_cmp(fl1->opt, fl->opt))
 570                                         goto release;
 571
 572                                 err = -ENOMEM;
 573                                 if (sfl1 == NULL)
 574                                         goto release;
 575                                 if (fl->linger > fl1->linger)
 576                                         fl1->linger = fl->linger;
 577                                 if ((long)(fl->expires - fl1->expires) > 0)
 578                                         fl1->expires = fl->expires;
 579                                 fl_link(np, sfl1, fl1);
 580                                 fl_free(fl);
 581                                 return 0;
 582
 583 release:
 584                                 fl_release(fl1);
 585                                 goto done;
 586                         }
 587                 }
 588                 err = -ENOENT;
 589                 if (!(freq.flr_flags&IPV6_FL_F_CREATE))
 590                         goto done;
 591
 592                 err = -ENOMEM;
 593                 if (sfl1 == NULL || (err = mem_check(sk)) != 0)
 594                         goto done;
 595
 596                 fl1 = fl_intern(net, fl, freq.flr_label);
 597                 if (fl1 != NULL)
 598                         goto recheck;
 599
 600                 if (!freq.flr_label) {
 601                         if (copy_to_user(&((struct in6_flowlabel_req __user *) optval)->flr_label,
 602                                          &fl->label, sizeof(fl->label))) {
 603                                 /* Intentionally ignore fault. */
 604                         }
 605                 }
 606
 607                 fl_link(np, sfl1, fl);
 608                 return 0;
 609
 610         default:
 611                 return -EINVAL;
 612         }
 613
 614 done:
 615         fl_free(fl);
 616         kfree(sfl1);
 617         return err;
 618 }
 619
 620 #ifdef CONFIG_PROC_FS
 621
 622 struct ip6fl_iter_state {
 623         struct seq_net_private p;
 624         int bucket;
 625 };
 626
 627 #define ip6fl_seq_private(seq)  ((struct ip6fl_iter_state *)(seq)->private)
 628
 629 static struct ip6_flowlabel *ip6fl_get_first(struct seq_file *seq)
 630 {
 631         struct ip6_flowlabel *fl = NULL;
 632         struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 633         struct net *net = seq_file_net(seq);
 634
 635         for (state->bucket = 0; state->bucket <= FL_HASH_MASK; ++state->bucket) {
 636                 fl = fl_ht[state->bucket];
 637
 638                 while (fl && !net_eq(fl->fl_net, net))
 639                         fl = fl->next;
 640                 if (fl)
 641                         break;
 642         }
 643         return fl;
 644 }
 645
 646 static struct ip6_flowlabel *ip6fl_get_next(struct seq_file *seq, struct ip6_flowlabel *fl)
 647 {
 648         struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 649         struct net *net = seq_file_net(seq);
 650
 651         fl = fl->next;
 652 try_again:
 653         while (fl && !net_eq(fl->fl_net, net))
 654                 fl = fl->next;
 655
 656         while (!fl) {
 657                 if (++state->bucket <= FL_HASH_MASK) {
 658                         fl = fl_ht[state->bucket];
 659                         goto try_again;
 660                 } else
 661                         break;
 662         }
 663         return fl;
 664 }
 665
 666 static struct ip6_flowlabel *ip6fl_get_idx(struct seq_file *seq, loff_t pos)
 667 {
 668         struct ip6_flowlabel *fl = ip6fl_get_first(seq);
 669         if (fl)
 670                 while (pos && (fl = ip6fl_get_next(seq, fl)) != NULL)
 671                         --pos;
 672         return pos ? NULL : fl;
 673 }
 674
 675 static void *ip6fl_seq_start(struct seq_file *seq, loff_t *pos)
 676         __acquires(ip6_fl_lock)
 677 {
 678         read_lock_bh(&ip6_fl_lock);
 679         return *pos ? ip6fl_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
 680 }
 681
 682 static void *ip6fl_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 683 {
 684         struct ip6_flowlabel *fl;
 685
 686         if (v == SEQ_START_TOKEN)
 687                 fl = ip6fl_get_first(seq);
 688         else
 689                 fl = ip6fl_get_next(seq, v);
 690         ++*pos;
 691         return fl;
 692 }
 693
 694 static void ip6fl_seq_stop(struct seq_file *seq, void *v)
 695         __releases(ip6_fl_lock)
 696 {
 697         read_unlock_bh(&ip6_fl_lock);
 698 }
 699
 700 static int ip6fl_seq_show(struct seq_file *seq, void *v)
 701 {
 702         if (v == SEQ_START_TOKEN)
 703                 seq_printf(seq, "%-5s %-1s %-6s %-6s %-6s %-8s %-32s %s\n",
 704                            "Label", "S", "Owner", "Users", "Linger", "Expires", "Dst", "Opt");
 705         else {
 706                 struct ip6_flowlabel *fl = v;
 707                 seq_printf(seq,
 708                            "%05X %-1d %-6d %-6d %-6ld %-8ld %pi6 %-4d\n",
 709                            (unsigned int)ntohl(fl->label),
 710                            fl->share,
 711                            (int)fl->owner,
 712                            atomic_read(&fl->users),
 713                            fl->linger/HZ,
 714                            (long)(fl->expires - jiffies)/HZ,
 715                            &fl->dst,
 716                            fl->opt ? fl->opt->opt_nflen : 0);
 717         }
 718         return 0;
 719 }
 720
 721 static const struct seq_operations ip6fl_seq_ops = {
 722         .start  =       ip6fl_seq_start,
 723         .next   =       ip6fl_seq_next,
 724         .stop   =       ip6fl_seq_stop,
 725         .show   =       ip6fl_seq_show,
 726 };
 727
 728 static int ip6fl_seq_open(struct inode *inode, struct file *file)
 729 {
 730         return seq_open_net(inode, file, &ip6fl_seq_ops,
 731                             sizeof(struct ip6fl_iter_state));
 732 }
 733
 734 static const struct file_operations ip6fl_seq_fops = {
 735         .owner          =       THIS_MODULE,
 736         .open           =       ip6fl_seq_open,
 737         .read           =       seq_read,
 738         .llseek         =       seq_lseek,
 739         .release        =       seq_release_net,
 740 };
 741
 742 static int __net_init ip6_flowlabel_proc_init(struct net *net)
 743 {
 744         if (!proc_net_fops_create(net, "ip6_flowlabel",
 745                                   S_IRUGO, &ip6fl_seq_fops))
 746                 return -ENOMEM;
 747         return 0;
 748 }
 749
 750 static void __net_exit ip6_flowlabel_proc_fini(struct net *net)
 751 {
 752         proc_net_remove(net, "ip6_flowlabel");
 753 }
 754 #else
 755 static inline int ip6_flowlabel_proc_init(struct net *net)
 756 {
 757         return 0;
 758 }
 759 static inline void ip6_flowlabel_proc_fini(struct net *net)
 760 {
 761 }
 762 #endif
 763
 764 static void __net_exit ip6_flowlabel_net_exit(struct net *net)
 765 {
 766         ip6_fl_purge(net);
 767         ip6_flowlabel_proc_fini(net);
 768 }
 769
 770 static struct pernet_operations ip6_flowlabel_net_ops = {
 771         .init = ip6_flowlabel_proc_init,
 772         .exit = ip6_flowlabel_net_exit,
 773 };
 774
 775 int ip6_flowlabel_init(void)
 776 {
 777         return register_pernet_subsys(&ip6_flowlabel_net_ops);
 778 }
 779
 780 void ip6_flowlabel_cleanup(void)
 781 {
 782         del_timer(&ip6_fl_gc_timer);
 783         unregister_pernet_subsys(&ip6_flowlabel_net_ops);
 784 }