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   1 /*
   2  *      ip6_flowlabel.c         IPv6 flowlabel manager.
   3  *
   4  *      This program is free software; you can redistribute it and/or
   5  *      modify it under the terms of the GNU General Public License
   6  *      as published by the Free Software Foundation; either version
   7  *      2 of the License, or (at your option) any later version.
   8  *
   9  *      Authors:        Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
  10  */
  11
  12 #include <linux/capability.h>
  13 #include <linux/errno.h>
  14 #include <linux/types.h>
  15 #include <linux/socket.h>
  16 #include <linux/net.h>
  17 #include <linux/netdevice.h>
  18 #include <linux/if_arp.h>
  19 #include <linux/in6.h>
  20 #include <linux/route.h>
  21 #include <linux/proc_fs.h>
  22 #include <linux/seq_file.h>
  23
  24 #include <net/net_namespace.h>
  25 #include <net/sock.h>
  26
  27 #include <net/ipv6.h>
  28 #include <net/ndisc.h>
  29 #include <net/protocol.h>
  30 #include <net/ip6_route.h>
  31 #include <net/addrconf.h>
  32 #include <net/rawv6.h>
  33 #include <net/icmp.h>
  34 #include <net/transp_v6.h>
  35
  36 #include <asm/uaccess.h>
  37
  38 #define FL_MIN_LINGER   6       /* Minimal linger. It is set to 6sec specified
  39                                    in old IPv6 RFC. Well, it was reasonable value.
  40                                  */
  41 #define FL_MAX_LINGER   60      /* Maximal linger timeout */
  42
  43 /* FL hash table */
  44
  45 #define FL_MAX_PER_SOCK 32
  46 #define FL_MAX_SIZE     4096
  47 #define FL_HASH_MASK    255
  48 #define FL_HASH(l)      (ntohl(l)&FL_HASH_MASK)
  49
  50 static atomic_t fl_size = ATOMIC_INIT(0);
  51 static struct ip6_flowlabel *fl_ht[FL_HASH_MASK+1];
  52
  53 static void ip6_fl_gc(unsigned long dummy);
  54 static DEFINE_TIMER(ip6_fl_gc_timer, ip6_fl_gc, 0, 0);
  55
  56 /* FL hash table lock: it protects only of GC */
  57
  58 static DEFINE_RWLOCK(ip6_fl_lock);
  59
  60 /* Big socket sock */
  61
  62 static DEFINE_RWLOCK(ip6_sk_fl_lock);
  63
  64
  65 static inline struct ip6_flowlabel *__fl_lookup(struct net *net, __be32 label)
  66 {
  67         struct ip6_flowlabel *fl;
  68
  69         for (fl=fl_ht[FL_HASH(label)]; fl; fl = fl->next) {
  70                 if (fl->label == label && net_eq(fl->fl_net, net))
  71                         return fl;
  72         }
  73         return NULL;
  74 }
  75
  76 static struct ip6_flowlabel *fl_lookup(struct net *net, __be32 label)
  77 {
  78         struct ip6_flowlabel *fl;
  79
  80         read_lock_bh(&ip6_fl_lock);
  81         fl = __fl_lookup(net, label);
  82         if (fl)
  83                 atomic_inc(&fl->users);
  84         read_unlock_bh(&ip6_fl_lock);
  85         return fl;
  86 }
  87
  88
  89 static void fl_free(struct ip6_flowlabel *fl)
  90 {
  91         if (fl) {
  92                 release_net(fl->fl_net);
  93                 kfree(fl->opt);
  94         }
  95         kfree(fl);
  96 }
  97
  98 static void fl_release(struct ip6_flowlabel *fl)
  99 {
 100         write_lock_bh(&ip6_fl_lock);
 101
 102         fl->lastuse = jiffies;
 103         if (atomic_dec_and_test(&fl->users)) {
 104                 unsigned long ttd = fl->lastuse + fl->linger;
 105                 if (time_after(ttd, fl->expires))
 106                         fl->expires = ttd;
 107                 ttd = fl->expires;
 108                 if (fl->opt && fl->share == IPV6_FL_S_EXCL) {
 109                         struct ipv6_txoptions *opt = fl->opt;
 110                         fl->opt = NULL;
 111                         kfree(opt);
 112                 }
 113                 if (!timer_pending(&ip6_fl_gc_timer) ||
 114                     time_after(ip6_fl_gc_timer.expires, ttd))
 115                         mod_timer(&ip6_fl_gc_timer, ttd);
 116         }
 117         write_unlock_bh(&ip6_fl_lock);
 118 }
 119
 120 static void ip6_fl_gc(unsigned long dummy)
 121 {
 122         int i;
 123         unsigned long now = jiffies;
 124         unsigned long sched = 0;
 125
 126         write_lock(&ip6_fl_lock);
 127
 128         for (i=0; i<=FL_HASH_MASK; i++) {
 129                 struct ip6_flowlabel *fl, **flp;
 130                 flp = &fl_ht[i];
 131                 while ((fl=*flp) != NULL) {
 132                         if (atomic_read(&fl->users) == 0) {
 133                                 unsigned long ttd = fl->lastuse + fl->linger;
 134                                 if (time_after(ttd, fl->expires))
 135                                         fl->expires = ttd;
 136                                 ttd = fl->expires;
 137                                 if (time_after_eq(now, ttd)) {
 138                                         *flp = fl->next;
 139                                         fl_free(fl);
 140                                         atomic_dec(&fl_size);
 141                                         continue;
 142                                 }
 143                                 if (!sched || time_before(ttd, sched))
 144                                         sched = ttd;
 145                         }
 146                         flp = &fl->next;
 147                 }
 148         }
 149         if (!sched && atomic_read(&fl_size))
 150                 sched = now + FL_MAX_LINGER;
 151         if (sched) {
 152                 mod_timer(&ip6_fl_gc_timer, sched);
 153         }
 154         write_unlock(&ip6_fl_lock);
 155 }
 156
 157 static void __net_exit ip6_fl_purge(struct net *net)
 158 {
 159         int i;
 160
 161         write_lock(&ip6_fl_lock);
 162         for (i = 0; i <= FL_HASH_MASK; i++) {
 163                 struct ip6_flowlabel *fl, **flp;
 164                 flp = &fl_ht[i];
 165                 while ((fl = *flp) != NULL) {
 166                         if (net_eq(fl->fl_net, net) &&
 167                             atomic_read(&fl->users) == 0) {
 168                                 *flp = fl->next;
 169                                 fl_free(fl);
 170                                 atomic_dec(&fl_size);
 171                                 continue;
 172                         }
 173                         flp = &fl->next;
 174                 }
 175         }
 176         write_unlock(&ip6_fl_lock);
 177 }
 178
 179 static struct ip6_flowlabel *fl_intern(struct net *net,
 180                                        struct ip6_flowlabel *fl, __be32 label)
 181 {
 182         struct ip6_flowlabel *lfl;
 183
 184         fl->label = label & IPV6_FLOWLABEL_MASK;
 185
 186         write_lock_bh(&ip6_fl_lock);
 187         if (label == 0) {
 188                 for (;;) {
 189                         fl->label = htonl(net_random())&IPV6_FLOWLABEL_MASK;
 190                         if (fl->label) {
 191                                 lfl = __fl_lookup(net, fl->label);
 192                                 if (lfl == NULL)
 193                                         break;
 194                         }
 195                 }
 196         } else {
 197                 /*
 198                  * we dropper the ip6_fl_lock, so this entry could reappear
 199                  * and we need to recheck with it.
 200                  *
 201                  * OTOH no need to search the active socket first, like it is
 202                  * done in ipv6_flowlabel_opt - sock is locked, so new entry
 203                  * with the same label can only appear on another sock
 204                  */
 205                 lfl = __fl_lookup(net, fl->label);
 206                 if (lfl != NULL) {
 207                         atomic_inc(&lfl->users);
 208                         write_unlock_bh(&ip6_fl_lock);
 209                         return lfl;
 210                 }
 211         }
 212
 213         fl->lastuse = jiffies;
 214         fl->next = fl_ht[FL_HASH(fl->label)];
 215         fl_ht[FL_HASH(fl->label)] = fl;
 216         atomic_inc(&fl_size);
 217         write_unlock_bh(&ip6_fl_lock);
 218         return NULL;
 219 }
 220
 221
 222
 223 /* Socket flowlabel lists */
 224
 225 struct ip6_flowlabel * fl6_sock_lookup(struct sock *sk, __be32 label)
 226 {
 227         struct ipv6_fl_socklist *sfl;
 228         struct ipv6_pinfo *np = inet6_sk(sk);
 229
 230         label &= IPV6_FLOWLABEL_MASK;
 231
 232         read_lock_bh(&ip6_sk_fl_lock);
 233         for (sfl=np->ipv6_fl_list; sfl; sfl = sfl->next) {
 234                 struct ip6_flowlabel *fl = sfl->fl;
 235                 if (fl->label == label) {
 236                         fl->lastuse = jiffies;
 237                         atomic_inc(&fl->users);
 238                         read_unlock_bh(&ip6_sk_fl_lock);
 239                         return fl;
 240                 }
 241         }
 242         read_unlock_bh(&ip6_sk_fl_lock);
 243         return NULL;
 244 }
 245
 246 EXPORT_SYMBOL_GPL(fl6_sock_lookup);
 247
 248 void fl6_free_socklist(struct sock *sk)
 249 {
 250         struct ipv6_pinfo *np = inet6_sk(sk);
 251         struct ipv6_fl_socklist *sfl;
 252
 253         while ((sfl = np->ipv6_fl_list) != NULL) {
 254                 np->ipv6_fl_list = sfl->next;
 255                 fl_release(sfl->fl);
 256                 kfree(sfl);
 257         }
 258 }
 259
 260 /* Service routines */
 261
 262
 263 /*
 264    It is the only difficult place. flowlabel enforces equal headers
 265    before and including routing header, however user may supply options
 266    following rthdr.
 267  */
 268
 269 struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions * opt_space,
 270                                          struct ip6_flowlabel * fl,
 271                                          struct ipv6_txoptions * fopt)
 272 {
 273         struct ipv6_txoptions * fl_opt = fl->opt;
 274
 275         if (fopt == NULL || fopt->opt_flen == 0)
 276                 return fl_opt;
 277
 278         if (fl_opt != NULL) {
 279                 opt_space->hopopt = fl_opt->hopopt;
 280                 opt_space->dst0opt = fl_opt->dst0opt;
 281                 opt_space->srcrt = fl_opt->srcrt;
 282                 opt_space->opt_nflen = fl_opt->opt_nflen;
 283         } else {
 284                 if (fopt->opt_nflen == 0)
 285                         return fopt;
 286                 opt_space->hopopt = NULL;
 287                 opt_space->dst0opt = NULL;
 288                 opt_space->srcrt = NULL;
 289                 opt_space->opt_nflen = 0;
 290         }
 291         opt_space->dst1opt = fopt->dst1opt;
 292         opt_space->opt_flen = fopt->opt_flen;
 293         return opt_space;
 294 }
 295
 296 static unsigned long check_linger(unsigned long ttl)
 297 {
 298         if (ttl < FL_MIN_LINGER)
 299                 return FL_MIN_LINGER*HZ;
 300         if (ttl > FL_MAX_LINGER && !capable(CAP_NET_ADMIN))
 301                 return 0;
 302         return ttl*HZ;
 303 }
 304
 305 static int fl6_renew(struct ip6_flowlabel *fl, unsigned long linger, unsigned long expires)
 306 {
 307         linger = check_linger(linger);
 308         if (!linger)
 309                 return -EPERM;
 310         expires = check_linger(expires);
 311         if (!expires)
 312                 return -EPERM;
 313         fl->lastuse = jiffies;
 314         if (time_before(fl->linger, linger))
 315                 fl->linger = linger;
 316         if (time_before(expires, fl->linger))
 317                 expires = fl->linger;
 318         if (time_before(fl->expires, fl->lastuse + expires))
 319                 fl->expires = fl->lastuse + expires;
 320         return 0;
 321 }
 322
 323 static struct ip6_flowlabel *
 324 fl_create(struct net *net, struct in6_flowlabel_req *freq, char __user *optval,
 325           int optlen, int *err_p)
 326 {
 327         struct ip6_flowlabel *fl = NULL;
 328         int olen;
 329         int addr_type;
 330         int err;
 331
 332         olen = optlen - CMSG_ALIGN(sizeof(*freq));
 333         err = -EINVAL;
 334         if (olen > 64 * 1024)
 335                 goto done;
 336
 337         err = -ENOMEM;
 338         fl = kzalloc(sizeof(*fl), GFP_KERNEL);
 339         if (fl == NULL)
 340                 goto done;
 341
 342         if (olen > 0) {
 343                 struct msghdr msg;
 344                 struct flowi flowi;
 345                 int junk;
 346
 347                 err = -ENOMEM;
 348                 fl->opt = kmalloc(sizeof(*fl->opt) + olen, GFP_KERNEL);
 349                 if (fl->opt == NULL)
 350                         goto done;
 351
 352                 memset(fl->opt, 0, sizeof(*fl->opt));
 353                 fl->opt->tot_len = sizeof(*fl->opt) + olen;
 354                 err = -EFAULT;
 355                 if (copy_from_user(fl->opt+1, optval+CMSG_ALIGN(sizeof(*freq)), olen))
 356                         goto done;
 357
 358                 msg.msg_controllen = olen;
 359                 msg.msg_control = (void*)(fl->opt+1);
 360                 flowi.oif = 0;
 361
 362                 err = datagram_send_ctl(net, &msg, &flowi, fl->opt, &junk, &junk);
 363                 if (err)
 364                         goto done;
 365                 err = -EINVAL;
 366                 if (fl->opt->opt_flen)
 367                         goto done;
 368                 if (fl->opt->opt_nflen == 0) {
 369                         kfree(fl->opt);
 370                         fl->opt = NULL;
 371                 }
 372         }
 373
 374         fl->fl_net = hold_net(net);
 375         fl->expires = jiffies;
 376         err = fl6_renew(fl, freq->flr_linger, freq->flr_expires);
 377         if (err)
 378                 goto done;
 379         fl->share = freq->flr_share;
 380         addr_type = ipv6_addr_type(&freq->flr_dst);
 381         if ((addr_type & IPV6_ADDR_MAPPED) ||
 382             addr_type == IPV6_ADDR_ANY) {
 383                 err = -EINVAL;
 384                 goto done;
 385         }
 386         ipv6_addr_copy(&fl->dst, &freq->flr_dst);
 387         atomic_set(&fl->users, 1);
 388         switch (fl->share) {
 389         case IPV6_FL_S_EXCL:
 390         case IPV6_FL_S_ANY:
 391                 break;
 392         case IPV6_FL_S_PROCESS:
 393                 fl->owner = current->pid;
 394                 break;
 395         case IPV6_FL_S_USER:
 396                 fl->owner = current_euid();
 397                 break;
 398         default:
 399                 err = -EINVAL;
 400                 goto done;
 401         }
 402         return fl;
 403
 404 done:
 405         fl_free(fl);
 406         *err_p = err;
 407         return NULL;
 408 }
 409
 410 static int mem_check(struct sock *sk)
 411 {
 412         struct ipv6_pinfo *np = inet6_sk(sk);
 413         struct ipv6_fl_socklist *sfl;
 414         int room = FL_MAX_SIZE - atomic_read(&fl_size);
 415         int count = 0;
 416
 417         if (room > FL_MAX_SIZE - FL_MAX_PER_SOCK)
 418                 return 0;
 419
 420         for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next)
 421                 count++;
 422
 423         if (room <= 0 ||
 424             ((count >= FL_MAX_PER_SOCK ||
 425               (count > 0 && room < FL_MAX_SIZE/2) || room < FL_MAX_SIZE/4) &&
 426              !capable(CAP_NET_ADMIN)))
 427                 return -ENOBUFS;
 428
 429         return 0;
 430 }
 431
 432 static int ipv6_hdr_cmp(struct ipv6_opt_hdr *h1, struct ipv6_opt_hdr *h2)
 433 {
 434         if (h1 == h2)
 435                 return 0;
 436         if (h1 == NULL || h2 == NULL)
 437                 return 1;
 438         if (h1->hdrlen != h2->hdrlen)
 439                 return 1;
 440         return memcmp(h1+1, h2+1, ((h1->hdrlen+1)<<3) - sizeof(*h1));
 441 }
 442
 443 static int ipv6_opt_cmp(struct ipv6_txoptions *o1, struct ipv6_txoptions *o2)
 444 {
 445         if (o1 == o2)
 446                 return 0;
 447         if (o1 == NULL || o2 == NULL)
 448                 return 1;
 449         if (o1->opt_nflen != o2->opt_nflen)
 450                 return 1;
 451         if (ipv6_hdr_cmp(o1->hopopt, o2->hopopt))
 452                 return 1;
 453         if (ipv6_hdr_cmp(o1->dst0opt, o2->dst0opt))
 454                 return 1;
 455         if (ipv6_hdr_cmp((struct ipv6_opt_hdr *)o1->srcrt, (struct ipv6_opt_hdr *)o2->srcrt))
 456                 return 1;
 457         return 0;
 458 }
 459
 460 static inline void fl_link(struct ipv6_pinfo *np, struct ipv6_fl_socklist *sfl,
 461                 struct ip6_flowlabel *fl)
 462 {
 463         write_lock_bh(&ip6_sk_fl_lock);
 464         sfl->fl = fl;
 465         sfl->next = np->ipv6_fl_list;
 466         np->ipv6_fl_list = sfl;
 467         write_unlock_bh(&ip6_sk_fl_lock);
 468 }
 469
 470 int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen)
 471 {
 472         int uninitialized_var(err);
 473         struct net *net = sock_net(sk);
 474         struct ipv6_pinfo *np = inet6_sk(sk);
 475         struct in6_flowlabel_req freq;
 476         struct ipv6_fl_socklist *sfl1=NULL;
 477         struct ipv6_fl_socklist *sfl, **sflp;
 478         struct ip6_flowlabel *fl, *fl1 = NULL;
 479
 480
 481         if (optlen < sizeof(freq))
 482                 return -EINVAL;
 483
 484         if (copy_from_user(&freq, optval, sizeof(freq)))
 485                 return -EFAULT;
 486
 487         switch (freq.flr_action) {
 488         case IPV6_FL_A_PUT:
 489                 write_lock_bh(&ip6_sk_fl_lock);
 490                 for (sflp = &np->ipv6_fl_list; (sfl=*sflp)!=NULL; sflp = &sfl->next) {
 491                         if (sfl->fl->label == freq.flr_label) {
 492                                 if (freq.flr_label == (np->flow_label&IPV6_FLOWLABEL_MASK))
 493                                         np->flow_label &= ~IPV6_FLOWLABEL_MASK;
 494                                 *sflp = sfl->next;
 495                                 write_unlock_bh(&ip6_sk_fl_lock);
 496                                 fl_release(sfl->fl);
 497                                 kfree(sfl);
 498                                 return 0;
 499                         }
 500                 }
 501                 write_unlock_bh(&ip6_sk_fl_lock);
 502                 return -ESRCH;
 503
 504         case IPV6_FL_A_RENEW:
 505                 read_lock_bh(&ip6_sk_fl_lock);
 506                 for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next) {
 507                         if (sfl->fl->label == freq.flr_label) {
 508                                 err = fl6_renew(sfl->fl, freq.flr_linger, freq.flr_expires);
 509                                 read_unlock_bh(&ip6_sk_fl_lock);
 510                                 return err;
 511                         }
 512                 }
 513                 read_unlock_bh(&ip6_sk_fl_lock);
 514
 515                 if (freq.flr_share == IPV6_FL_S_NONE && capable(CAP_NET_ADMIN)) {
 516                         fl = fl_lookup(net, freq.flr_label);
 517                         if (fl) {
 518                                 err = fl6_renew(fl, freq.flr_linger, freq.flr_expires);
 519                                 fl_release(fl);
 520                                 return err;
 521                         }
 522                 }
 523                 return -ESRCH;
 524
 525         case IPV6_FL_A_GET:
 526                 if (freq.flr_label & ~IPV6_FLOWLABEL_MASK)
 527                         return -EINVAL;
 528
 529                 fl = fl_create(net, &freq, optval, optlen, &err);
 530                 if (fl == NULL)
 531                         return err;
 532                 sfl1 = kmalloc(sizeof(*sfl1), GFP_KERNEL);
 533
 534                 if (freq.flr_label) {
 535                         err = -EEXIST;
 536                         read_lock_bh(&ip6_sk_fl_lock);
 537                         for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next) {
 538                                 if (sfl->fl->label == freq.flr_label) {
 539                                         if (freq.flr_flags&IPV6_FL_F_EXCL) {
 540                                                 read_unlock_bh(&ip6_sk_fl_lock);
 541                                                 goto done;
 542                                         }
 543                                         fl1 = sfl->fl;
 544                                         atomic_inc(&fl1->users);
 545                                         break;
 546                                 }
 547                         }
 548                         read_unlock_bh(&ip6_sk_fl_lock);
 549
 550                         if (fl1 == NULL)
 551                                 fl1 = fl_lookup(net, freq.flr_label);
 552                         if (fl1) {
 553 recheck:
 554                                 err = -EEXIST;
 555                                 if (freq.flr_flags&IPV6_FL_F_EXCL)
 556                                         goto release;
 557                                 err = -EPERM;
 558                                 if (fl1->share == IPV6_FL_S_EXCL ||
 559                                     fl1->share != fl->share ||
 560                                     fl1->owner != fl->owner)
 561                                         goto release;
 562
 563                                 err = -EINVAL;
 564                                 if (!ipv6_addr_equal(&fl1->dst, &fl->dst) ||
 565                                     ipv6_opt_cmp(fl1->opt, fl->opt))
 566                                         goto release;
 567
 568                                 err = -ENOMEM;
 569                                 if (sfl1 == NULL)
 570                                         goto release;
 571                                 if (fl->linger > fl1->linger)
 572                                         fl1->linger = fl->linger;
 573                                 if ((long)(fl->expires - fl1->expires) > 0)
 574                                         fl1->expires = fl->expires;
 575                                 fl_link(np, sfl1, fl1);
 576                                 fl_free(fl);
 577                                 return 0;
 578
 579 release:
 580                                 fl_release(fl1);
 581                                 goto done;
 582                         }
 583                 }
 584                 err = -ENOENT;
 585                 if (!(freq.flr_flags&IPV6_FL_F_CREATE))
 586                         goto done;
 587
 588                 err = -ENOMEM;
 589                 if (sfl1 == NULL || (err = mem_check(sk)) != 0)
 590                         goto done;
 591
 592                 fl1 = fl_intern(net, fl, freq.flr_label);
 593                 if (fl1 != NULL)
 594                         goto recheck;
 595
 596                 if (!freq.flr_label) {
 597                         if (copy_to_user(&((struct in6_flowlabel_req __user *) optval)->flr_label,
 598                                          &fl->label, sizeof(fl->label))) {
 599                                 /* Intentionally ignore fault. */
 600                         }
 601                 }
 602
 603                 fl_link(np, sfl1, fl);
 604                 return 0;
 605
 606         default:
 607                 return -EINVAL;
 608         }
 609
 610 done:
 611         fl_free(fl);
 612         kfree(sfl1);
 613         return err;
 614 }
 615
 616 #ifdef CONFIG_PROC_FS
 617
 618 struct ip6fl_iter_state {
 619         struct seq_net_private p;
 620         int bucket;
 621 };
 622
 623 #define ip6fl_seq_private(seq)  ((struct ip6fl_iter_state *)(seq)->private)
 624
 625 static struct ip6_flowlabel *ip6fl_get_first(struct seq_file *seq)
 626 {
 627         struct ip6_flowlabel *fl = NULL;
 628         struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 629         struct net *net = seq_file_net(seq);
 630
 631         for (state->bucket = 0; state->bucket <= FL_HASH_MASK; ++state->bucket) {
 632                 fl = fl_ht[state->bucket];
 633
 634                 while (fl && !net_eq(fl->fl_net, net))
 635                         fl = fl->next;
 636                 if (fl)
 637                         break;
 638         }
 639         return fl;
 640 }
 641
 642 static struct ip6_flowlabel *ip6fl_get_next(struct seq_file *seq, struct ip6_flowlabel *fl)
 643 {
 644         struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 645         struct net *net = seq_file_net(seq);
 646
 647         fl = fl->next;
 648 try_again:
 649         while (fl && !net_eq(fl->fl_net, net))
 650                 fl = fl->next;
 651
 652         while (!fl) {
 653                 if (++state->bucket <= FL_HASH_MASK) {
 654                         fl = fl_ht[state->bucket];
 655                         goto try_again;
 656                 } else
 657                         break;
 658         }
 659         return fl;
 660 }
 661
 662 static struct ip6_flowlabel *ip6fl_get_idx(struct seq_file *seq, loff_t pos)
 663 {
 664         struct ip6_flowlabel *fl = ip6fl_get_first(seq);
 665         if (fl)
 666                 while (pos && (fl = ip6fl_get_next(seq, fl)) != NULL)
 667                         --pos;
 668         return pos ? NULL : fl;
 669 }
 670
 671 static void *ip6fl_seq_start(struct seq_file *seq, loff_t *pos)
 672         __acquires(ip6_fl_lock)
 673 {
 674         read_lock_bh(&ip6_fl_lock);
 675         return *pos ? ip6fl_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
 676 }
 677
 678 static void *ip6fl_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 679 {
 680         struct ip6_flowlabel *fl;
 681
 682         if (v == SEQ_START_TOKEN)
 683                 fl = ip6fl_get_first(seq);
 684         else
 685                 fl = ip6fl_get_next(seq, v);
 686         ++*pos;
 687         return fl;
 688 }
 689
 690 static void ip6fl_seq_stop(struct seq_file *seq, void *v)
 691         __releases(ip6_fl_lock)
 692 {
 693         read_unlock_bh(&ip6_fl_lock);
 694 }
 695
 696 static int ip6fl_seq_show(struct seq_file *seq, void *v)
 697 {
 698         if (v == SEQ_START_TOKEN)
 699                 seq_printf(seq, "%-5s %-1s %-6s %-6s %-6s %-8s %-32s %s\n",
 700                            "Label", "S", "Owner", "Users", "Linger", "Expires", "Dst", "Opt");
 701         else {
 702                 struct ip6_flowlabel *fl = v;
 703                 seq_printf(seq,
 704                            "%05X %-1d %-6d %-6d %-6ld %-8ld %pi6 %-4d\n",
 705                            (unsigned)ntohl(fl->label),
 706                            fl->share,
 707                            (unsigned)fl->owner,
 708                            atomic_read(&fl->users),
 709                            fl->linger/HZ,
 710                            (long)(fl->expires - jiffies)/HZ,
 711                            &fl->dst,
 712                            fl->opt ? fl->opt->opt_nflen : 0);
 713         }
 714         return 0;
 715 }
 716
 717 static const struct seq_operations ip6fl_seq_ops = {
 718         .start  =       ip6fl_seq_start,
 719         .next   =       ip6fl_seq_next,
 720         .stop   =       ip6fl_seq_stop,
 721         .show   =       ip6fl_seq_show,
 722 };
 723
 724 static int ip6fl_seq_open(struct inode *inode, struct file *file)
 725 {
 726         return seq_open_net(inode, file, &ip6fl_seq_ops,
 727                             sizeof(struct ip6fl_iter_state));
 728 }
 729
 730 static const struct file_operations ip6fl_seq_fops = {
 731         .owner          =       THIS_MODULE,
 732         .open           =       ip6fl_seq_open,
 733         .read           =       seq_read,
 734         .llseek         =       seq_lseek,
 735         .release        =       seq_release_net,
 736 };
 737
 738 static int __net_init ip6_flowlabel_proc_init(struct net *net)
 739 {
 740         if (!proc_net_fops_create(net, "ip6_flowlabel",
 741                                   S_IRUGO, &ip6fl_seq_fops))
 742                 return -ENOMEM;
 743         return 0;
 744 }
 745
 746 static void __net_exit ip6_flowlabel_proc_fini(struct net *net)
 747 {
 748         proc_net_remove(net, "ip6_flowlabel");
 749 }
 750 #else
 751 static inline int ip6_flowlabel_proc_init(struct net *net)
 752 {
 753         return 0;
 754 }
 755 static inline void ip6_flowlabel_proc_fini(struct net *net)
 756 {
 757 }
 758 #endif
 759
 760 static void __net_exit ip6_flowlabel_net_exit(struct net *net)
 761 {
 762         ip6_fl_purge(net);
 763         ip6_flowlabel_proc_fini(net);
 764 }
 765
 766 static struct pernet_operations ip6_flowlabel_net_ops = {
 767         .init = ip6_flowlabel_proc_init,
 768         .exit = ip6_flowlabel_net_exit,
 769 };
 770
 771 int ip6_flowlabel_init(void)
 772 {
 773         return register_pernet_subsys(&ip6_flowlabel_net_ops);
 774 }
 775
 776 void ip6_flowlabel_cleanup(void)
 777 {
 778         del_timer(&ip6_fl_gc_timer);
 779         unregister_pernet_subsys(&ip6_flowlabel_net_ops);
 780 }