linux/net/ipv6/ip6_flowlabel.c
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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
  50static atomic_t fl_size = ATOMIC_INIT(0);
  51static struct ip6_flowlabel *fl_ht[FL_HASH_MASK+1];
  52
  53static void ip6_fl_gc(unsigned long dummy);
  54static DEFINE_TIMER(ip6_fl_gc_timer, ip6_fl_gc, 0, 0);
  55
  56/* FL hash table lock: it protects only of GC */
  57
  58static DEFINE_RWLOCK(ip6_fl_lock);
  59
  60/* Big socket sock */
  61
  62static DEFINE_RWLOCK(ip6_sk_fl_lock);
  63
  64
  65static 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 && fl->fl_net == net)
  71                        return fl;
  72        }
  73        return NULL;
  74}
  75
  76static 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
  89static 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
  98static 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
 120static 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
 157static void 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 (fl->fl_net == net && atomic_read(&fl->users) == 0) {
 167                                *flp = fl->next;
 168                                fl_free(fl);
 169                                atomic_dec(&fl_size);
 170                                continue;
 171                        }
 172                        flp = &fl->next;
 173                }
 174        }
 175        write_unlock(&ip6_fl_lock);
 176}
 177
 178static struct ip6_flowlabel *fl_intern(struct net *net,
 179                                       struct ip6_flowlabel *fl, __be32 label)
 180{
 181        struct ip6_flowlabel *lfl;
 182
 183        fl->label = label & IPV6_FLOWLABEL_MASK;
 184
 185        write_lock_bh(&ip6_fl_lock);
 186        if (label == 0) {
 187                for (;;) {
 188                        fl->label = htonl(net_random())&IPV6_FLOWLABEL_MASK;
 189                        if (fl->label) {
 190                                lfl = __fl_lookup(net, fl->label);
 191                                if (lfl == NULL)
 192                                        break;
 193                        }
 194                }
 195        } else {
 196                /*
 197                 * we dropper the ip6_fl_lock, so this entry could reappear
 198                 * and we need to recheck with it.
 199                 *
 200                 * OTOH no need to search the active socket first, like it is
 201                 * done in ipv6_flowlabel_opt - sock is locked, so new entry
 202                 * with the same label can only appear on another sock
 203                 */
 204                lfl = __fl_lookup(net, fl->label);
 205                if (lfl != NULL) {
 206                        atomic_inc(&lfl->users);
 207                        write_unlock_bh(&ip6_fl_lock);
 208                        return lfl;
 209                }
 210        }
 211
 212        fl->lastuse = jiffies;
 213        fl->next = fl_ht[FL_HASH(fl->label)];
 214        fl_ht[FL_HASH(fl->label)] = fl;
 215        atomic_inc(&fl_size);
 216        write_unlock_bh(&ip6_fl_lock);
 217        return NULL;
 218}
 219
 220
 221
 222/* Socket flowlabel lists */
 223
 224struct ip6_flowlabel * fl6_sock_lookup(struct sock *sk, __be32 label)
 225{
 226        struct ipv6_fl_socklist *sfl;
 227        struct ipv6_pinfo *np = inet6_sk(sk);
 228
 229        label &= IPV6_FLOWLABEL_MASK;
 230
 231        read_lock_bh(&ip6_sk_fl_lock);
 232        for (sfl=np->ipv6_fl_list; sfl; sfl = sfl->next) {
 233                struct ip6_flowlabel *fl = sfl->fl;
 234                if (fl->label == label) {
 235                        fl->lastuse = jiffies;
 236                        atomic_inc(&fl->users);
 237                        read_unlock_bh(&ip6_sk_fl_lock);
 238                        return fl;
 239                }
 240        }
 241        read_unlock_bh(&ip6_sk_fl_lock);
 242        return NULL;
 243}
 244
 245EXPORT_SYMBOL_GPL(fl6_sock_lookup);
 246
 247void fl6_free_socklist(struct sock *sk)
 248{
 249        struct ipv6_pinfo *np = inet6_sk(sk);
 250        struct ipv6_fl_socklist *sfl;
 251
 252        while ((sfl = np->ipv6_fl_list) != NULL) {
 253                np->ipv6_fl_list = sfl->next;
 254                fl_release(sfl->fl);
 255                kfree(sfl);
 256        }
 257}
 258
 259/* Service routines */
 260
 261
 262/*
 263   It is the only difficult place. flowlabel enforces equal headers
 264   before and including routing header, however user may supply options
 265   following rthdr.
 266 */
 267
 268struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions * opt_space,
 269                                         struct ip6_flowlabel * fl,
 270                                         struct ipv6_txoptions * fopt)
 271{
 272        struct ipv6_txoptions * fl_opt = fl->opt;
 273
 274        if (fopt == NULL || fopt->opt_flen == 0)
 275                return fl_opt;
 276
 277        if (fl_opt != NULL) {
 278                opt_space->hopopt = fl_opt->hopopt;
 279                opt_space->dst0opt = fl_opt->dst0opt;
 280                opt_space->srcrt = fl_opt->srcrt;
 281                opt_space->opt_nflen = fl_opt->opt_nflen;
 282        } else {
 283                if (fopt->opt_nflen == 0)
 284                        return fopt;
 285                opt_space->hopopt = NULL;
 286                opt_space->dst0opt = NULL;
 287                opt_space->srcrt = NULL;
 288                opt_space->opt_nflen = 0;
 289        }
 290        opt_space->dst1opt = fopt->dst1opt;
 291        opt_space->opt_flen = fopt->opt_flen;
 292        return opt_space;
 293}
 294
 295static unsigned long check_linger(unsigned long ttl)
 296{
 297        if (ttl < FL_MIN_LINGER)
 298                return FL_MIN_LINGER*HZ;
 299        if (ttl > FL_MAX_LINGER && !capable(CAP_NET_ADMIN))
 300                return 0;
 301        return ttl*HZ;
 302}
 303
 304static int fl6_renew(struct ip6_flowlabel *fl, unsigned long linger, unsigned long expires)
 305{
 306        linger = check_linger(linger);
 307        if (!linger)
 308                return -EPERM;
 309        expires = check_linger(expires);
 310        if (!expires)
 311                return -EPERM;
 312        fl->lastuse = jiffies;
 313        if (time_before(fl->linger, linger))
 314                fl->linger = linger;
 315        if (time_before(expires, fl->linger))
 316                expires = fl->linger;
 317        if (time_before(fl->expires, fl->lastuse + expires))
 318                fl->expires = fl->lastuse + expires;
 319        return 0;
 320}
 321
 322static struct ip6_flowlabel *
 323fl_create(struct net *net, struct in6_flowlabel_req *freq, char __user *optval,
 324          int optlen, int *err_p)
 325{
 326        struct ip6_flowlabel *fl;
 327        int olen;
 328        int addr_type;
 329        int err;
 330
 331        err = -ENOMEM;
 332        fl = kzalloc(sizeof(*fl), GFP_KERNEL);
 333        if (fl == NULL)
 334                goto done;
 335
 336        olen = optlen - CMSG_ALIGN(sizeof(*freq));
 337        if (olen > 0) {
 338                struct msghdr msg;
 339                struct flowi flowi;
 340                int junk;
 341
 342                err = -ENOMEM;
 343                fl->opt = kmalloc(sizeof(*fl->opt) + olen, GFP_KERNEL);
 344                if (fl->opt == NULL)
 345                        goto done;
 346
 347                memset(fl->opt, 0, sizeof(*fl->opt));
 348                fl->opt->tot_len = sizeof(*fl->opt) + olen;
 349                err = -EFAULT;
 350                if (copy_from_user(fl->opt+1, optval+CMSG_ALIGN(sizeof(*freq)), olen))
 351                        goto done;
 352
 353                msg.msg_controllen = olen;
 354                msg.msg_control = (void*)(fl->opt+1);
 355                flowi.oif = 0;
 356
 357                err = datagram_send_ctl(net, &msg, &flowi, fl->opt, &junk, &junk);
 358                if (err)
 359                        goto done;
 360                err = -EINVAL;
 361                if (fl->opt->opt_flen)
 362                        goto done;
 363                if (fl->opt->opt_nflen == 0) {
 364                        kfree(fl->opt);
 365                        fl->opt = NULL;
 366                }
 367        }
 368
 369        fl->fl_net = hold_net(net);
 370        fl->expires = jiffies;
 371        err = fl6_renew(fl, freq->flr_linger, freq->flr_expires);
 372        if (err)
 373                goto done;
 374        fl->share = freq->flr_share;
 375        addr_type = ipv6_addr_type(&freq->flr_dst);
 376        if ((addr_type&IPV6_ADDR_MAPPED)
 377            || addr_type == IPV6_ADDR_ANY) {
 378                err = -EINVAL;
 379                goto done;
 380        }
 381        ipv6_addr_copy(&fl->dst, &freq->flr_dst);
 382        atomic_set(&fl->users, 1);
 383        switch (fl->share) {
 384        case IPV6_FL_S_EXCL:
 385        case IPV6_FL_S_ANY:
 386                break;
 387        case IPV6_FL_S_PROCESS:
 388                fl->owner = current->pid;
 389                break;
 390        case IPV6_FL_S_USER:
 391                fl->owner = current->euid;
 392                break;
 393        default:
 394                err = -EINVAL;
 395                goto done;
 396        }
 397        return fl;
 398
 399done:
 400        fl_free(fl);
 401        *err_p = err;
 402        return NULL;
 403}
 404
 405static int mem_check(struct sock *sk)
 406{
 407        struct ipv6_pinfo *np = inet6_sk(sk);
 408        struct ipv6_fl_socklist *sfl;
 409        int room = FL_MAX_SIZE - atomic_read(&fl_size);
 410        int count = 0;
 411
 412        if (room > FL_MAX_SIZE - FL_MAX_PER_SOCK)
 413                return 0;
 414
 415        for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next)
 416                count++;
 417
 418        if (room <= 0 ||
 419            ((count >= FL_MAX_PER_SOCK ||
 420             (count > 0 && room < FL_MAX_SIZE/2) || room < FL_MAX_SIZE/4)
 421             && !capable(CAP_NET_ADMIN)))
 422                return -ENOBUFS;
 423
 424        return 0;
 425}
 426
 427static int ipv6_hdr_cmp(struct ipv6_opt_hdr *h1, struct ipv6_opt_hdr *h2)
 428{
 429        if (h1 == h2)
 430                return 0;
 431        if (h1 == NULL || h2 == NULL)
 432                return 1;
 433        if (h1->hdrlen != h2->hdrlen)
 434                return 1;
 435        return memcmp(h1+1, h2+1, ((h1->hdrlen+1)<<3) - sizeof(*h1));
 436}
 437
 438static int ipv6_opt_cmp(struct ipv6_txoptions *o1, struct ipv6_txoptions *o2)
 439{
 440        if (o1 == o2)
 441                return 0;
 442        if (o1 == NULL || o2 == NULL)
 443                return 1;
 444        if (o1->opt_nflen != o2->opt_nflen)
 445                return 1;
 446        if (ipv6_hdr_cmp(o1->hopopt, o2->hopopt))
 447                return 1;
 448        if (ipv6_hdr_cmp(o1->dst0opt, o2->dst0opt))
 449                return 1;
 450        if (ipv6_hdr_cmp((struct ipv6_opt_hdr *)o1->srcrt, (struct ipv6_opt_hdr *)o2->srcrt))
 451                return 1;
 452        return 0;
 453}
 454
 455static inline void fl_link(struct ipv6_pinfo *np, struct ipv6_fl_socklist *sfl,
 456                struct ip6_flowlabel *fl)
 457{
 458        write_lock_bh(&ip6_sk_fl_lock);
 459        sfl->fl = fl;
 460        sfl->next = np->ipv6_fl_list;
 461        np->ipv6_fl_list = sfl;
 462        write_unlock_bh(&ip6_sk_fl_lock);
 463}
 464
 465int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen)
 466{
 467        int err;
 468        struct net *net = sock_net(sk);
 469        struct ipv6_pinfo *np = inet6_sk(sk);
 470        struct in6_flowlabel_req freq;
 471        struct ipv6_fl_socklist *sfl1=NULL;
 472        struct ipv6_fl_socklist *sfl, **sflp;
 473        struct ip6_flowlabel *fl, *fl1 = NULL;
 474
 475
 476        if (optlen < sizeof(freq))
 477                return -EINVAL;
 478
 479        if (copy_from_user(&freq, optval, sizeof(freq)))
 480                return -EFAULT;
 481
 482        switch (freq.flr_action) {
 483        case IPV6_FL_A_PUT:
 484                write_lock_bh(&ip6_sk_fl_lock);
 485                for (sflp = &np->ipv6_fl_list; (sfl=*sflp)!=NULL; sflp = &sfl->next) {
 486                        if (sfl->fl->label == freq.flr_label) {
 487                                if (freq.flr_label == (np->flow_label&IPV6_FLOWLABEL_MASK))
 488                                        np->flow_label &= ~IPV6_FLOWLABEL_MASK;
 489                                *sflp = sfl->next;
 490                                write_unlock_bh(&ip6_sk_fl_lock);
 491                                fl_release(sfl->fl);
 492                                kfree(sfl);
 493                                return 0;
 494                        }
 495                }
 496                write_unlock_bh(&ip6_sk_fl_lock);
 497                return -ESRCH;
 498
 499        case IPV6_FL_A_RENEW:
 500                read_lock_bh(&ip6_sk_fl_lock);
 501                for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next) {
 502                        if (sfl->fl->label == freq.flr_label) {
 503                                err = fl6_renew(sfl->fl, freq.flr_linger, freq.flr_expires);
 504                                read_unlock_bh(&ip6_sk_fl_lock);
 505                                return err;
 506                        }
 507                }
 508                read_unlock_bh(&ip6_sk_fl_lock);
 509
 510                if (freq.flr_share == IPV6_FL_S_NONE && capable(CAP_NET_ADMIN)) {
 511                        fl = fl_lookup(net, freq.flr_label);
 512                        if (fl) {
 513                                err = fl6_renew(fl, freq.flr_linger, freq.flr_expires);
 514                                fl_release(fl);
 515                                return err;
 516                        }
 517                }
 518                return -ESRCH;
 519
 520        case IPV6_FL_A_GET:
 521                if (freq.flr_label & ~IPV6_FLOWLABEL_MASK)
 522                        return -EINVAL;
 523
 524                fl = fl_create(net, &freq, optval, optlen, &err);
 525                if (fl == NULL)
 526                        return err;
 527                sfl1 = kmalloc(sizeof(*sfl1), GFP_KERNEL);
 528
 529                if (freq.flr_label) {
 530                        err = -EEXIST;
 531                        read_lock_bh(&ip6_sk_fl_lock);
 532                        for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next) {
 533                                if (sfl->fl->label == freq.flr_label) {
 534                                        if (freq.flr_flags&IPV6_FL_F_EXCL) {
 535                                                read_unlock_bh(&ip6_sk_fl_lock);
 536                                                goto done;
 537                                        }
 538                                        fl1 = sfl->fl;
 539                                        atomic_inc(&fl1->users);
 540                                        break;
 541                                }
 542                        }
 543                        read_unlock_bh(&ip6_sk_fl_lock);
 544
 545                        if (fl1 == NULL)
 546                                fl1 = fl_lookup(net, freq.flr_label);
 547                        if (fl1) {
 548recheck:
 549                                err = -EEXIST;
 550                                if (freq.flr_flags&IPV6_FL_F_EXCL)
 551                                        goto release;
 552                                err = -EPERM;
 553                                if (fl1->share == IPV6_FL_S_EXCL ||
 554                                    fl1->share != fl->share ||
 555                                    fl1->owner != fl->owner)
 556                                        goto release;
 557
 558                                err = -EINVAL;
 559                                if (!ipv6_addr_equal(&fl1->dst, &fl->dst) ||
 560                                    ipv6_opt_cmp(fl1->opt, fl->opt))
 561                                        goto release;
 562
 563                                err = -ENOMEM;
 564                                if (sfl1 == NULL)
 565                                        goto release;
 566                                if (fl->linger > fl1->linger)
 567                                        fl1->linger = fl->linger;
 568                                if ((long)(fl->expires - fl1->expires) > 0)
 569                                        fl1->expires = fl->expires;
 570                                fl_link(np, sfl1, fl1);
 571                                fl_free(fl);
 572                                return 0;
 573
 574release:
 575                                fl_release(fl1);
 576                                goto done;
 577                        }
 578                }
 579                err = -ENOENT;
 580                if (!(freq.flr_flags&IPV6_FL_F_CREATE))
 581                        goto done;
 582
 583                err = -ENOMEM;
 584                if (sfl1 == NULL || (err = mem_check(sk)) != 0)
 585                        goto done;
 586
 587                fl1 = fl_intern(net, fl, freq.flr_label);
 588                if (fl1 != NULL)
 589                        goto recheck;
 590
 591                if (!freq.flr_label) {
 592                        if (copy_to_user(&((struct in6_flowlabel_req __user *) optval)->flr_label,
 593                                         &fl->label, sizeof(fl->label))) {
 594                                /* Intentionally ignore fault. */
 595                        }
 596                }
 597
 598                fl_link(np, sfl1, fl);
 599                return 0;
 600
 601        default:
 602                return -EINVAL;
 603        }
 604
 605done:
 606        fl_free(fl);
 607        kfree(sfl1);
 608        return err;
 609}
 610
 611#ifdef CONFIG_PROC_FS
 612
 613struct ip6fl_iter_state {
 614        struct seq_net_private p;
 615        int bucket;
 616};
 617
 618#define ip6fl_seq_private(seq)  ((struct ip6fl_iter_state *)(seq)->private)
 619
 620static struct ip6_flowlabel *ip6fl_get_first(struct seq_file *seq)
 621{
 622        struct ip6_flowlabel *fl = NULL;
 623        struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 624        struct net *net = seq_file_net(seq);
 625
 626        for (state->bucket = 0; state->bucket <= FL_HASH_MASK; ++state->bucket) {
 627                fl = fl_ht[state->bucket];
 628
 629                while (fl && fl->fl_net != net)
 630                        fl = fl->next;
 631                if (fl)
 632                        break;
 633        }
 634        return fl;
 635}
 636
 637static struct ip6_flowlabel *ip6fl_get_next(struct seq_file *seq, struct ip6_flowlabel *fl)
 638{
 639        struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 640        struct net *net = seq_file_net(seq);
 641
 642        fl = fl->next;
 643try_again:
 644        while (fl && fl->fl_net != net)
 645                fl = fl->next;
 646
 647        while (!fl) {
 648                if (++state->bucket <= FL_HASH_MASK) {
 649                        fl = fl_ht[state->bucket];
 650                        goto try_again;
 651                } else
 652                        break;
 653        }
 654        return fl;
 655}
 656
 657static struct ip6_flowlabel *ip6fl_get_idx(struct seq_file *seq, loff_t pos)
 658{
 659        struct ip6_flowlabel *fl = ip6fl_get_first(seq);
 660        if (fl)
 661                while (pos && (fl = ip6fl_get_next(seq, fl)) != NULL)
 662                        --pos;
 663        return pos ? NULL : fl;
 664}
 665
 666static void *ip6fl_seq_start(struct seq_file *seq, loff_t *pos)
 667        __acquires(ip6_fl_lock)
 668{
 669        read_lock_bh(&ip6_fl_lock);
 670        return *pos ? ip6fl_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
 671}
 672
 673static void *ip6fl_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 674{
 675        struct ip6_flowlabel *fl;
 676
 677        if (v == SEQ_START_TOKEN)
 678                fl = ip6fl_get_first(seq);
 679        else
 680                fl = ip6fl_get_next(seq, v);
 681        ++*pos;
 682        return fl;
 683}
 684
 685static void ip6fl_seq_stop(struct seq_file *seq, void *v)
 686        __releases(ip6_fl_lock)
 687{
 688        read_unlock_bh(&ip6_fl_lock);
 689}
 690
 691static int ip6fl_seq_show(struct seq_file *seq, void *v)
 692{
 693        if (v == SEQ_START_TOKEN)
 694                seq_printf(seq, "%-5s %-1s %-6s %-6s %-6s %-8s %-32s %s\n",
 695                           "Label", "S", "Owner", "Users", "Linger", "Expires", "Dst", "Opt");
 696        else {
 697                struct ip6_flowlabel *fl = v;
 698                seq_printf(seq,
 699                           "%05X %-1d %-6d %-6d %-6ld %-8ld " NIP6_SEQFMT " %-4d\n",
 700                           (unsigned)ntohl(fl->label),
 701                           fl->share,
 702                           (unsigned)fl->owner,
 703                           atomic_read(&fl->users),
 704                           fl->linger/HZ,
 705                           (long)(fl->expires - jiffies)/HZ,
 706                           NIP6(fl->dst),
 707                           fl->opt ? fl->opt->opt_nflen : 0);
 708        }
 709        return 0;
 710}
 711
 712static const struct seq_operations ip6fl_seq_ops = {
 713        .start  =       ip6fl_seq_start,
 714        .next   =       ip6fl_seq_next,
 715        .stop   =       ip6fl_seq_stop,
 716        .show   =       ip6fl_seq_show,
 717};
 718
 719static int ip6fl_seq_open(struct inode *inode, struct file *file)
 720{
 721        return seq_open_net(inode, file, &ip6fl_seq_ops,
 722                            sizeof(struct ip6fl_iter_state));
 723}
 724
 725static const struct file_operations ip6fl_seq_fops = {
 726        .owner          =       THIS_MODULE,
 727        .open           =       ip6fl_seq_open,
 728        .read           =       seq_read,
 729        .llseek         =       seq_lseek,
 730        .release        =       seq_release_net,
 731};
 732
 733static int ip6_flowlabel_proc_init(struct net *net)
 734{
 735        if (!proc_net_fops_create(net, "ip6_flowlabel",
 736                                  S_IRUGO, &ip6fl_seq_fops))
 737                return -ENOMEM;
 738        return 0;
 739}
 740
 741static void ip6_flowlabel_proc_fini(struct net *net)
 742{
 743        proc_net_remove(net, "ip6_flowlabel");
 744}
 745#else
 746static inline int ip6_flowlabel_proc_init(struct net *net)
 747{
 748        return 0;
 749}
 750static inline void ip6_flowlabel_proc_fini(struct net *net)
 751{
 752        return ;
 753}
 754#endif
 755
 756static inline void ip6_flowlabel_net_exit(struct net *net)
 757{
 758        ip6_fl_purge(net);
 759        ip6_flowlabel_proc_fini(net);
 760}
 761
 762static struct pernet_operations ip6_flowlabel_net_ops = {
 763        .init = ip6_flowlabel_proc_init,
 764        .exit = ip6_flowlabel_net_exit,
 765};
 766
 767int ip6_flowlabel_init(void)
 768{
 769        return register_pernet_subsys(&ip6_flowlabel_net_ops);
 770}
 771
 772void ip6_flowlabel_cleanup(void)
 773{
 774        del_timer(&ip6_fl_gc_timer);
 775        unregister_pernet_subsys(&ip6_flowlabel_net_ops);
 776}
 777
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