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
 298 static unsigned long check_linger(unsigned long ttl)
 299 {
 300         if (ttl < FL_MIN_LINGER)
 301                 return FL_MIN_LINGER*HZ;
 302         if (ttl > FL_MAX_LINGER && !capable(CAP_NET_ADMIN))
 303                 return 0;
 304         return ttl*HZ;
 305 }
 306
 307 static int fl6_renew(struct ip6_flowlabel *fl, unsigned long linger, unsigned long expires)
 308 {
 309         linger = check_linger(linger);
 310         if (!linger)
 311                 return -EPERM;
 312         expires = check_linger(expires);
 313         if (!expires)
 314                 return -EPERM;
 315         fl->lastuse = jiffies;
 316         if (time_before(fl->linger, linger))
 317                 fl->linger = linger;
 318         if (time_before(expires, fl->linger))
 319                 expires = fl->linger;
 320         if (time_before(fl->expires, fl->lastuse + expires))
 321                 fl->expires = fl->lastuse + expires;
 322         return 0;
 323 }
 324
 325 static struct ip6_flowlabel *
 326 fl_create(struct net *net, struct sock *sk, struct in6_flowlabel_req *freq,
 327           char __user *optval, int optlen, int *err_p)
 328 {
 329         struct ip6_flowlabel *fl = NULL;
 330         int olen;
 331         int addr_type;
 332         int err;
 333
 334         olen = optlen - CMSG_ALIGN(sizeof(*freq));
 335         err = -EINVAL;
 336         if (olen > 64 * 1024)
 337                 goto done;
 338
 339         err = -ENOMEM;
 340         fl = kzalloc(sizeof(*fl), GFP_KERNEL);
 341         if (fl == NULL)
 342                 goto done;
 343
 344         if (olen > 0) {
 345                 struct msghdr msg;
 346                 struct flowi6 flowi6;
 347                 int junk;
 348
 349                 err = -ENOMEM;
 350                 fl->opt = kmalloc(sizeof(*fl->opt) + olen, GFP_KERNEL);
 351                 if (fl->opt == NULL)
 352                         goto done;
 353
 354                 memset(fl->opt, 0, sizeof(*fl->opt));
 355                 fl->opt->tot_len = sizeof(*fl->opt) + olen;
 356                 err = -EFAULT;
 357                 if (copy_from_user(fl->opt+1, optval+CMSG_ALIGN(sizeof(*freq)), olen))
 358                         goto done;
 359
 360                 msg.msg_controllen = olen;
 361                 msg.msg_control = (void*)(fl->opt+1);
 362                 memset(&flowi6, 0, sizeof(flowi6));
 363
 364                 err = datagram_send_ctl(net, sk, &msg, &flowi6, fl->opt, &junk,
 365                                         &junk, &junk);
 366                 if (err)
 367                         goto done;
 368                 err = -EINVAL;
 369                 if (fl->opt->opt_flen)
 370                         goto done;
 371                 if (fl->opt->opt_nflen == 0) {
 372                         kfree(fl->opt);
 373                         fl->opt = NULL;
 374                 }
 375         }
 376
 377         fl->fl_net = hold_net(net);
 378         fl->expires = jiffies;
 379         err = fl6_renew(fl, freq->flr_linger, freq->flr_expires);
 380         if (err)
 381                 goto done;
 382         fl->share = freq->flr_share;
 383         addr_type = ipv6_addr_type(&freq->flr_dst);
 384         if ((addr_type & IPV6_ADDR_MAPPED) ||
 385             addr_type == IPV6_ADDR_ANY) {
 386                 err = -EINVAL;
 387                 goto done;
 388         }
 389         ipv6_addr_copy(&fl->dst, &freq->flr_dst);
 390         atomic_set(&fl->users, 1);
 391         switch (fl->share) {
 392         case IPV6_FL_S_EXCL:
 393         case IPV6_FL_S_ANY:
 394                 break;
 395         case IPV6_FL_S_PROCESS:
 396                 fl->owner = current->pid;
 397                 break;
 398         case IPV6_FL_S_USER:
 399                 fl->owner = current_euid();
 400                 break;
 401         default:
 402                 err = -EINVAL;
 403                 goto done;
 404         }
 405         return fl;
 406
 407 done:
 408         fl_free(fl);
 409         *err_p = err;
 410         return NULL;
 411 }
 412
 413 static int mem_check(struct sock *sk)
 414 {
 415         struct ipv6_pinfo *np = inet6_sk(sk);
 416         struct ipv6_fl_socklist *sfl;
 417         int room = FL_MAX_SIZE - atomic_read(&fl_size);
 418         int count = 0;
 419
 420         if (room > FL_MAX_SIZE - FL_MAX_PER_SOCK)
 421                 return 0;
 422
 423         for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next)
 424                 count++;
 425
 426         if (room <= 0 ||
 427             ((count >= FL_MAX_PER_SOCK ||
 428               (count > 0 && room < FL_MAX_SIZE/2) || room < FL_MAX_SIZE/4) &&
 429              !capable(CAP_NET_ADMIN)))
 430                 return -ENOBUFS;
 431
 432         return 0;
 433 }
 434
 435 static int ipv6_hdr_cmp(struct ipv6_opt_hdr *h1, struct ipv6_opt_hdr *h2)
 436 {
 437         if (h1 == h2)
 438                 return 0;
 439         if (h1 == NULL || h2 == NULL)
 440                 return 1;
 441         if (h1->hdrlen != h2->hdrlen)
 442                 return 1;
 443         return memcmp(h1+1, h2+1, ((h1->hdrlen+1)<<3) - sizeof(*h1));
 444 }
 445
 446 static int ipv6_opt_cmp(struct ipv6_txoptions *o1, struct ipv6_txoptions *o2)
 447 {
 448         if (o1 == o2)
 449                 return 0;
 450         if (o1 == NULL || o2 == NULL)
 451                 return 1;
 452         if (o1->opt_nflen != o2->opt_nflen)
 453                 return 1;
 454         if (ipv6_hdr_cmp(o1->hopopt, o2->hopopt))
 455                 return 1;
 456         if (ipv6_hdr_cmp(o1->dst0opt, o2->dst0opt))
 457                 return 1;
 458         if (ipv6_hdr_cmp((struct ipv6_opt_hdr *)o1->srcrt, (struct ipv6_opt_hdr *)o2->srcrt))
 459                 return 1;
 460         return 0;
 461 }
 462
 463 static inline void fl_link(struct ipv6_pinfo *np, struct ipv6_fl_socklist *sfl,
 464                 struct ip6_flowlabel *fl)
 465 {
 466         write_lock_bh(&ip6_sk_fl_lock);
 467         sfl->fl = fl;
 468         sfl->next = np->ipv6_fl_list;
 469         np->ipv6_fl_list = sfl;
 470         write_unlock_bh(&ip6_sk_fl_lock);
 471 }
 472
 473 int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen)
 474 {
 475         int uninitialized_var(err);
 476         struct net *net = sock_net(sk);
 477         struct ipv6_pinfo *np = inet6_sk(sk);
 478         struct in6_flowlabel_req freq;
 479         struct ipv6_fl_socklist *sfl1=NULL;
 480         struct ipv6_fl_socklist *sfl, **sflp;
 481         struct ip6_flowlabel *fl, *fl1 = NULL;
 482
 483
 484         if (optlen < sizeof(freq))
 485                 return -EINVAL;
 486
 487         if (copy_from_user(&freq, optval, sizeof(freq)))
 488                 return -EFAULT;
 489
 490         switch (freq.flr_action) {
 491         case IPV6_FL_A_PUT:
 492                 write_lock_bh(&ip6_sk_fl_lock);
 493                 for (sflp = &np->ipv6_fl_list; (sfl=*sflp)!=NULL; sflp = &sfl->next) {
 494                         if (sfl->fl->label == freq.flr_label) {
 495                                 if (freq.flr_label == (np->flow_label&IPV6_FLOWLABEL_MASK))
 496                                         np->flow_label &= ~IPV6_FLOWLABEL_MASK;
 497                                 *sflp = sfl->next;
 498                                 write_unlock_bh(&ip6_sk_fl_lock);
 499                                 fl_release(sfl->fl);
 500                                 kfree(sfl);
 501                                 return 0;
 502                         }
 503                 }
 504                 write_unlock_bh(&ip6_sk_fl_lock);
 505                 return -ESRCH;
 506
 507         case IPV6_FL_A_RENEW:
 508                 read_lock_bh(&ip6_sk_fl_lock);
 509                 for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next) {
 510                         if (sfl->fl->label == freq.flr_label) {
 511                                 err = fl6_renew(sfl->fl, freq.flr_linger, freq.flr_expires);
 512                                 read_unlock_bh(&ip6_sk_fl_lock);
 513                                 return err;
 514                         }
 515                 }
 516                 read_unlock_bh(&ip6_sk_fl_lock);
 517
 518                 if (freq.flr_share == IPV6_FL_S_NONE && capable(CAP_NET_ADMIN)) {
 519                         fl = fl_lookup(net, freq.flr_label);
 520                         if (fl) {
 521                                 err = fl6_renew(fl, freq.flr_linger, freq.flr_expires);
 522                                 fl_release(fl);
 523                                 return err;
 524                         }
 525                 }
 526                 return -ESRCH;
 527
 528         case IPV6_FL_A_GET:
 529                 if (freq.flr_label & ~IPV6_FLOWLABEL_MASK)
 530                         return -EINVAL;
 531
 532                 fl = fl_create(net, sk, &freq, optval, optlen, &err);
 533                 if (fl == NULL)
 534                         return err;
 535                 sfl1 = kmalloc(sizeof(*sfl1), GFP_KERNEL);
 536
 537                 if (freq.flr_label) {
 538                         err = -EEXIST;
 539                         read_lock_bh(&ip6_sk_fl_lock);
 540                         for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next) {
 541                                 if (sfl->fl->label == freq.flr_label) {
 542                                         if (freq.flr_flags&IPV6_FL_F_EXCL) {
 543                                                 read_unlock_bh(&ip6_sk_fl_lock);
 544                                                 goto done;
 545                                         }
 546                                         fl1 = sfl->fl;
 547                                         atomic_inc(&fl1->users);
 548                                         break;
 549                                 }
 550                         }
 551                         read_unlock_bh(&ip6_sk_fl_lock);
 552
 553                         if (fl1 == NULL)
 554                                 fl1 = fl_lookup(net, freq.flr_label);
 555                         if (fl1) {
 556 recheck:
 557                                 err = -EEXIST;
 558                                 if (freq.flr_flags&IPV6_FL_F_EXCL)
 559                                         goto release;
 560                                 err = -EPERM;
 561                                 if (fl1->share == IPV6_FL_S_EXCL ||
 562                                     fl1->share != fl->share ||
 563                                     fl1->owner != fl->owner)
 564                                         goto release;
 565
 566                                 err = -EINVAL;
 567                                 if (!ipv6_addr_equal(&fl1->dst, &fl->dst) ||
 568                                     ipv6_opt_cmp(fl1->opt, fl->opt))
 569                                         goto release;
 570
 571                                 err = -ENOMEM;
 572                                 if (sfl1 == NULL)
 573                                         goto release;
 574                                 if (fl->linger > fl1->linger)
 575                                         fl1->linger = fl->linger;
 576                                 if ((long)(fl->expires - fl1->expires) > 0)
 577                                         fl1->expires = fl->expires;
 578                                 fl_link(np, sfl1, fl1);
 579                                 fl_free(fl);
 580                                 return 0;
 581
 582 release:
 583                                 fl_release(fl1);
 584                                 goto done;
 585                         }
 586                 }
 587                 err = -ENOENT;
 588                 if (!(freq.flr_flags&IPV6_FL_F_CREATE))
 589                         goto done;
 590
 591                 err = -ENOMEM;
 592                 if (sfl1 == NULL || (err = mem_check(sk)) != 0)
 593                         goto done;
 594
 595                 fl1 = fl_intern(net, fl, freq.flr_label);
 596                 if (fl1 != NULL)
 597                         goto recheck;
 598
 599                 if (!freq.flr_label) {
 600                         if (copy_to_user(&((struct in6_flowlabel_req __user *) optval)->flr_label,
 601                                          &fl->label, sizeof(fl->label))) {
 602                                 /* Intentionally ignore fault. */
 603                         }
 604                 }
 605
 606                 fl_link(np, sfl1, fl);
 607                 return 0;
 608
 609         default:
 610                 return -EINVAL;
 611         }
 612
 613 done:
 614         fl_free(fl);
 615         kfree(sfl1);
 616         return err;
 617 }
 618
 619 #ifdef CONFIG_PROC_FS
 620
 621 struct ip6fl_iter_state {
 622         struct seq_net_private p;
 623         int bucket;
 624 };
 625
 626 #define ip6fl_seq_private(seq)  ((struct ip6fl_iter_state *)(seq)->private)
 627
 628 static struct ip6_flowlabel *ip6fl_get_first(struct seq_file *seq)
 629 {
 630         struct ip6_flowlabel *fl = NULL;
 631         struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 632         struct net *net = seq_file_net(seq);
 633
 634         for (state->bucket = 0; state->bucket <= FL_HASH_MASK; ++state->bucket) {
 635                 fl = fl_ht[state->bucket];
 636
 637                 while (fl && !net_eq(fl->fl_net, net))
 638                         fl = fl->next;
 639                 if (fl)
 640                         break;
 641         }
 642         return fl;
 643 }
 644
 645 static struct ip6_flowlabel *ip6fl_get_next(struct seq_file *seq, struct ip6_flowlabel *fl)
 646 {
 647         struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 648         struct net *net = seq_file_net(seq);
 649
 650         fl = fl->next;
 651 try_again:
 652         while (fl && !net_eq(fl->fl_net, net))
 653                 fl = fl->next;
 654
 655         while (!fl) {
 656                 if (++state->bucket <= FL_HASH_MASK) {
 657                         fl = fl_ht[state->bucket];
 658                         goto try_again;
 659                 } else
 660                         break;
 661         }
 662         return fl;
 663 }
 664
 665 static struct ip6_flowlabel *ip6fl_get_idx(struct seq_file *seq, loff_t pos)
 666 {
 667         struct ip6_flowlabel *fl = ip6fl_get_first(seq);
 668         if (fl)
 669                 while (pos && (fl = ip6fl_get_next(seq, fl)) != NULL)
 670                         --pos;
 671         return pos ? NULL : fl;
 672 }
 673
 674 static void *ip6fl_seq_start(struct seq_file *seq, loff_t *pos)
 675         __acquires(ip6_fl_lock)
 676 {
 677         read_lock_bh(&ip6_fl_lock);
 678         return *pos ? ip6fl_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
 679 }
 680
 681 static void *ip6fl_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 682 {
 683         struct ip6_flowlabel *fl;
 684
 685         if (v == SEQ_START_TOKEN)
 686                 fl = ip6fl_get_first(seq);
 687         else
 688                 fl = ip6fl_get_next(seq, v);
 689         ++*pos;
 690         return fl;
 691 }
 692
 693 static void ip6fl_seq_stop(struct seq_file *seq, void *v)
 694         __releases(ip6_fl_lock)
 695 {
 696         read_unlock_bh(&ip6_fl_lock);
 697 }
 698
 699 static int ip6fl_seq_show(struct seq_file *seq, void *v)
 700 {
 701         if (v == SEQ_START_TOKEN)
 702                 seq_printf(seq, "%-5s %-1s %-6s %-6s %-6s %-8s %-32s %s\n",
 703                            "Label", "S", "Owner", "Users", "Linger", "Expires", "Dst", "Opt");
 704         else {
 705                 struct ip6_flowlabel *fl = v;
 706                 seq_printf(seq,
 707                            "%05X %-1d %-6d %-6d %-6ld %-8ld %pi6 %-4d\n",
 708                            (unsigned)ntohl(fl->label),
 709                            fl->share,
 710                            (unsigned)fl->owner,
 711                            atomic_read(&fl->users),
 712                            fl->linger/HZ,
 713                            (long)(fl->expires - jiffies)/HZ,
 714                            &fl->dst,
 715                            fl->opt ? fl->opt->opt_nflen : 0);
 716         }
 717         return 0;
 718 }
 719
 720 static const struct seq_operations ip6fl_seq_ops = {
 721         .start  =       ip6fl_seq_start,
 722         .next   =       ip6fl_seq_next,
 723         .stop   =       ip6fl_seq_stop,
 724         .show   =       ip6fl_seq_show,
 725 };
 726
 727 static int ip6fl_seq_open(struct inode *inode, struct file *file)
 728 {
 729         return seq_open_net(inode, file, &ip6fl_seq_ops,
 730                             sizeof(struct ip6fl_iter_state));
 731 }
 732
 733 static const struct file_operations ip6fl_seq_fops = {
 734         .owner          =       THIS_MODULE,
 735         .open           =       ip6fl_seq_open,
 736         .read           =       seq_read,
 737         .llseek         =       seq_lseek,
 738         .release        =       seq_release_net,
 739 };
 740
 741 static int __net_init ip6_flowlabel_proc_init(struct net *net)
 742 {
 743         if (!proc_net_fops_create(net, "ip6_flowlabel",
 744                                   S_IRUGO, &ip6fl_seq_fops))
 745                 return -ENOMEM;
 746         return 0;
 747 }
 748
 749 static void __net_exit ip6_flowlabel_proc_fini(struct net *net)
 750 {
 751         proc_net_remove(net, "ip6_flowlabel");
 752 }
 753 #else
 754 static inline int ip6_flowlabel_proc_init(struct net *net)
 755 {
 756         return 0;
 757 }
 758 static inline void ip6_flowlabel_proc_fini(struct net *net)
 759 {
 760 }
 761 #endif
 762
 763 static void __net_exit ip6_flowlabel_net_exit(struct net *net)
 764 {
 765         ip6_fl_purge(net);
 766         ip6_flowlabel_proc_fini(net);
 767 }
 768
 769 static struct pernet_operations ip6_flowlabel_net_ops = {
 770         .init = ip6_flowlabel_proc_init,
 771         .exit = ip6_flowlabel_net_exit,
 772 };
 773
 774 int ip6_flowlabel_init(void)
 775 {
 776         return register_pernet_subsys(&ip6_flowlabel_net_ops);
 777 }
 778
 779 void ip6_flowlabel_cleanup(void)
 780 {
 781         del_timer(&ip6_fl_gc_timer);
 782         unregister_pernet_subsys(&ip6_flowlabel_net_ops);
 783 }