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#include <linux/slab.h>
  24#include <linux/export.h>
  25#include <linux/pid_namespace.h>
  26
  27#include <net/net_namespace.h>
  28#include <net/sock.h>
  29
  30#include <net/ipv6.h>
  31#include <net/ndisc.h>
  32#include <net/protocol.h>
  33#include <net/ip6_route.h>
  34#include <net/addrconf.h>
  35#include <net/rawv6.h>
  36#include <net/icmp.h>
  37#include <net/transp_v6.h>
  38
  39#include <asm/uaccess.h>
  40
  41#define FL_MIN_LINGER   6       /* Minimal linger. It is set to 6sec specified
  42                                   in old IPv6 RFC. Well, it was reasonable value.
  43                                 */
  44#define FL_MAX_LINGER   60      /* Maximal linger timeout */
  45
  46/* FL hash table */
  47
  48#define FL_MAX_PER_SOCK 32
  49#define FL_MAX_SIZE     4096
  50#define FL_HASH_MASK    255
  51#define FL_HASH(l)      (ntohl(l)&FL_HASH_MASK)
  52
  53static atomic_t fl_size = ATOMIC_INIT(0);
  54static struct ip6_flowlabel *fl_ht[FL_HASH_MASK+1];
  55
  56static void ip6_fl_gc(unsigned long dummy);
  57static DEFINE_TIMER(ip6_fl_gc_timer, ip6_fl_gc, 0, 0);
  58
  59/* FL hash table lock: it protects only of GC */
  60
  61static DEFINE_RWLOCK(ip6_fl_lock);
  62
  63/* Big socket sock */
  64
  65static DEFINE_RWLOCK(ip6_sk_fl_lock);
  66
  67
  68static inline struct ip6_flowlabel *__fl_lookup(struct net *net, __be32 label)
  69{
  70        struct ip6_flowlabel *fl;
  71
  72        for (fl=fl_ht[FL_HASH(label)]; fl; fl = fl->next) {
  73                if (fl->label == label && net_eq(fl->fl_net, net))
  74                        return fl;
  75        }
  76        return NULL;
  77}
  78
  79static struct ip6_flowlabel *fl_lookup(struct net *net, __be32 label)
  80{
  81        struct ip6_flowlabel *fl;
  82
  83        read_lock_bh(&ip6_fl_lock);
  84        fl = __fl_lookup(net, label);
  85        if (fl)
  86                atomic_inc(&fl->users);
  87        read_unlock_bh(&ip6_fl_lock);
  88        return fl;
  89}
  90
  91
  92static void fl_free(struct ip6_flowlabel *fl)
  93{
  94        if (fl) {
  95                if (fl->share == IPV6_FL_S_PROCESS)
  96                        put_pid(fl->owner.pid);
  97                release_net(fl->fl_net);
  98                kfree(fl->opt);
  99        }
 100        kfree(fl);
 101}
 102
 103static void fl_release(struct ip6_flowlabel *fl)
 104{
 105        write_lock_bh(&ip6_fl_lock);
 106
 107        fl->lastuse = jiffies;
 108        if (atomic_dec_and_test(&fl->users)) {
 109                unsigned long ttd = fl->lastuse + fl->linger;
 110                if (time_after(ttd, fl->expires))
 111                        fl->expires = ttd;
 112                ttd = fl->expires;
 113                if (fl->opt && fl->share == IPV6_FL_S_EXCL) {
 114                        struct ipv6_txoptions *opt = fl->opt;
 115                        fl->opt = NULL;
 116                        kfree(opt);
 117                }
 118                if (!timer_pending(&ip6_fl_gc_timer) ||
 119                    time_after(ip6_fl_gc_timer.expires, ttd))
 120                        mod_timer(&ip6_fl_gc_timer, ttd);
 121        }
 122        write_unlock_bh(&ip6_fl_lock);
 123}
 124
 125static void ip6_fl_gc(unsigned long dummy)
 126{
 127        int i;
 128        unsigned long now = jiffies;
 129        unsigned long sched = 0;
 130
 131        write_lock(&ip6_fl_lock);
 132
 133        for (i=0; i<=FL_HASH_MASK; i++) {
 134                struct ip6_flowlabel *fl, **flp;
 135                flp = &fl_ht[i];
 136                while ((fl=*flp) != NULL) {
 137                        if (atomic_read(&fl->users) == 0) {
 138                                unsigned long ttd = fl->lastuse + fl->linger;
 139                                if (time_after(ttd, fl->expires))
 140                                        fl->expires = ttd;
 141                                ttd = fl->expires;
 142                                if (time_after_eq(now, ttd)) {
 143                                        *flp = fl->next;
 144                                        fl_free(fl);
 145                                        atomic_dec(&fl_size);
 146                                        continue;
 147                                }
 148                                if (!sched || time_before(ttd, sched))
 149                                        sched = ttd;
 150                        }
 151                        flp = &fl->next;
 152                }
 153        }
 154        if (!sched && atomic_read(&fl_size))
 155                sched = now + FL_MAX_LINGER;
 156        if (sched) {
 157                mod_timer(&ip6_fl_gc_timer, sched);
 158        }
 159        write_unlock(&ip6_fl_lock);
 160}
 161
 162static void __net_exit ip6_fl_purge(struct net *net)
 163{
 164        int i;
 165
 166        write_lock(&ip6_fl_lock);
 167        for (i = 0; i <= FL_HASH_MASK; i++) {
 168                struct ip6_flowlabel *fl, **flp;
 169                flp = &fl_ht[i];
 170                while ((fl = *flp) != NULL) {
 171                        if (net_eq(fl->fl_net, net) &&
 172                            atomic_read(&fl->users) == 0) {
 173                                *flp = fl->next;
 174                                fl_free(fl);
 175                                atomic_dec(&fl_size);
 176                                continue;
 177                        }
 178                        flp = &fl->next;
 179                }
 180        }
 181        write_unlock(&ip6_fl_lock);
 182}
 183
 184static struct ip6_flowlabel *fl_intern(struct net *net,
 185                                       struct ip6_flowlabel *fl, __be32 label)
 186{
 187        struct ip6_flowlabel *lfl;
 188
 189        fl->label = label & IPV6_FLOWLABEL_MASK;
 190
 191        write_lock_bh(&ip6_fl_lock);
 192        if (label == 0) {
 193                for (;;) {
 194                        fl->label = htonl(net_random())&IPV6_FLOWLABEL_MASK;
 195                        if (fl->label) {
 196                                lfl = __fl_lookup(net, fl->label);
 197                                if (lfl == NULL)
 198                                        break;
 199                        }
 200                }
 201        } else {
 202                /*
 203                 * we dropper the ip6_fl_lock, so this entry could reappear
 204                 * and we need to recheck with it.
 205                 *
 206                 * OTOH no need to search the active socket first, like it is
 207                 * done in ipv6_flowlabel_opt - sock is locked, so new entry
 208                 * with the same label can only appear on another sock
 209                 */
 210                lfl = __fl_lookup(net, fl->label);
 211                if (lfl != NULL) {
 212                        atomic_inc(&lfl->users);
 213                        write_unlock_bh(&ip6_fl_lock);
 214                        return lfl;
 215                }
 216        }
 217
 218        fl->lastuse = jiffies;
 219        fl->next = fl_ht[FL_HASH(fl->label)];
 220        fl_ht[FL_HASH(fl->label)] = fl;
 221        atomic_inc(&fl_size);
 222        write_unlock_bh(&ip6_fl_lock);
 223        return NULL;
 224}
 225
 226
 227
 228/* Socket flowlabel lists */
 229
 230struct ip6_flowlabel * fl6_sock_lookup(struct sock *sk, __be32 label)
 231{
 232        struct ipv6_fl_socklist *sfl;
 233        struct ipv6_pinfo *np = inet6_sk(sk);
 234
 235        label &= IPV6_FLOWLABEL_MASK;
 236
 237        read_lock_bh(&ip6_sk_fl_lock);
 238        for (sfl=np->ipv6_fl_list; sfl; sfl = sfl->next) {
 239                struct ip6_flowlabel *fl = sfl->fl;
 240                if (fl->label == label) {
 241                        fl->lastuse = jiffies;
 242                        atomic_inc(&fl->users);
 243                        read_unlock_bh(&ip6_sk_fl_lock);
 244                        return fl;
 245                }
 246        }
 247        read_unlock_bh(&ip6_sk_fl_lock);
 248        return NULL;
 249}
 250
 251EXPORT_SYMBOL_GPL(fl6_sock_lookup);
 252
 253void fl6_free_socklist(struct sock *sk)
 254{
 255        struct ipv6_pinfo *np = inet6_sk(sk);
 256        struct ipv6_fl_socklist *sfl;
 257
 258        while ((sfl = np->ipv6_fl_list) != NULL) {
 259                np->ipv6_fl_list = sfl->next;
 260                fl_release(sfl->fl);
 261                kfree(sfl);
 262        }
 263}
 264
 265/* Service routines */
 266
 267
 268/*
 269   It is the only difficult place. flowlabel enforces equal headers
 270   before and including routing header, however user may supply options
 271   following rthdr.
 272 */
 273
 274struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions * opt_space,
 275                                         struct ip6_flowlabel * fl,
 276                                         struct ipv6_txoptions * fopt)
 277{
 278        struct ipv6_txoptions * fl_opt = fl->opt;
 279
 280        if (fopt == NULL || fopt->opt_flen == 0)
 281                return fl_opt;
 282
 283        if (fl_opt != NULL) {
 284                opt_space->hopopt = fl_opt->hopopt;
 285                opt_space->dst0opt = fl_opt->dst0opt;
 286                opt_space->srcrt = fl_opt->srcrt;
 287                opt_space->opt_nflen = fl_opt->opt_nflen;
 288        } else {
 289                if (fopt->opt_nflen == 0)
 290                        return fopt;
 291                opt_space->hopopt = NULL;
 292                opt_space->dst0opt = NULL;
 293                opt_space->srcrt = NULL;
 294                opt_space->opt_nflen = 0;
 295        }
 296        opt_space->dst1opt = fopt->dst1opt;
 297        opt_space->opt_flen = fopt->opt_flen;
 298        return opt_space;
 299}
 300EXPORT_SYMBOL_GPL(fl6_merge_options);
 301
 302static unsigned long check_linger(unsigned long ttl)
 303{
 304        if (ttl < FL_MIN_LINGER)
 305                return FL_MIN_LINGER*HZ;
 306        if (ttl > FL_MAX_LINGER && !capable(CAP_NET_ADMIN))
 307                return 0;
 308        return ttl*HZ;
 309}
 310
 311static int fl6_renew(struct ip6_flowlabel *fl, unsigned long linger, unsigned long expires)
 312{
 313        linger = check_linger(linger);
 314        if (!linger)
 315                return -EPERM;
 316        expires = check_linger(expires);
 317        if (!expires)
 318                return -EPERM;
 319        fl->lastuse = jiffies;
 320        if (time_before(fl->linger, linger))
 321                fl->linger = linger;
 322        if (time_before(expires, fl->linger))
 323                expires = fl->linger;
 324        if (time_before(fl->expires, fl->lastuse + expires))
 325                fl->expires = fl->lastuse + expires;
 326        return 0;
 327}
 328
 329static struct ip6_flowlabel *
 330fl_create(struct net *net, struct sock *sk, struct in6_flowlabel_req *freq,
 331          char __user *optval, int optlen, int *err_p)
 332{
 333        struct ip6_flowlabel *fl = NULL;
 334        int olen;
 335        int addr_type;
 336        int err;
 337
 338        olen = optlen - CMSG_ALIGN(sizeof(*freq));
 339        err = -EINVAL;
 340        if (olen > 64 * 1024)
 341                goto done;
 342
 343        err = -ENOMEM;
 344        fl = kzalloc(sizeof(*fl), GFP_KERNEL);
 345        if (fl == NULL)
 346                goto done;
 347
 348        if (olen > 0) {
 349                struct msghdr msg;
 350                struct flowi6 flowi6;
 351                int junk;
 352
 353                err = -ENOMEM;
 354                fl->opt = kmalloc(sizeof(*fl->opt) + olen, GFP_KERNEL);
 355                if (fl->opt == NULL)
 356                        goto done;
 357
 358                memset(fl->opt, 0, sizeof(*fl->opt));
 359                fl->opt->tot_len = sizeof(*fl->opt) + olen;
 360                err = -EFAULT;
 361                if (copy_from_user(fl->opt+1, optval+CMSG_ALIGN(sizeof(*freq)), olen))
 362                        goto done;
 363
 364                msg.msg_controllen = olen;
 365                msg.msg_control = (void*)(fl->opt+1);
 366                memset(&flowi6, 0, sizeof(flowi6));
 367
 368                err = datagram_send_ctl(net, sk, &msg, &flowi6, fl->opt, &junk,
 369                                        &junk, &junk);
 370                if (err)
 371                        goto done;
 372                err = -EINVAL;
 373                if (fl->opt->opt_flen)
 374                        goto done;
 375                if (fl->opt->opt_nflen == 0) {
 376                        kfree(fl->opt);
 377                        fl->opt = NULL;
 378                }
 379        }
 380
 381        fl->fl_net = hold_net(net);
 382        fl->expires = jiffies;
 383        err = fl6_renew(fl, freq->flr_linger, freq->flr_expires);
 384        if (err)
 385                goto done;
 386        fl->share = freq->flr_share;
 387        addr_type = ipv6_addr_type(&freq->flr_dst);
 388        if ((addr_type & IPV6_ADDR_MAPPED) ||
 389            addr_type == IPV6_ADDR_ANY) {
 390                err = -EINVAL;
 391                goto done;
 392        }
 393        fl->dst = freq->flr_dst;
 394        atomic_set(&fl->users, 1);
 395        switch (fl->share) {
 396        case IPV6_FL_S_EXCL:
 397        case IPV6_FL_S_ANY:
 398                break;
 399        case IPV6_FL_S_PROCESS:
 400                fl->owner.pid = get_task_pid(current, PIDTYPE_PID);
 401                break;
 402        case IPV6_FL_S_USER:
 403                fl->owner.uid = current_euid();
 404                break;
 405        default:
 406                err = -EINVAL;
 407                goto done;
 408        }
 409        return fl;
 410
 411done:
 412        fl_free(fl);
 413        *err_p = err;
 414        return NULL;
 415}
 416
 417static int mem_check(struct sock *sk)
 418{
 419        struct ipv6_pinfo *np = inet6_sk(sk);
 420        struct ipv6_fl_socklist *sfl;
 421        int room = FL_MAX_SIZE - atomic_read(&fl_size);
 422        int count = 0;
 423
 424        if (room > FL_MAX_SIZE - FL_MAX_PER_SOCK)
 425                return 0;
 426
 427        for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next)
 428                count++;
 429
 430        if (room <= 0 ||
 431            ((count >= FL_MAX_PER_SOCK ||
 432              (count > 0 && room < FL_MAX_SIZE/2) || room < FL_MAX_SIZE/4) &&
 433             !capable(CAP_NET_ADMIN)))
 434                return -ENOBUFS;
 435
 436        return 0;
 437}
 438
 439static bool ipv6_hdr_cmp(struct ipv6_opt_hdr *h1, struct ipv6_opt_hdr *h2)
 440{
 441        if (h1 == h2)
 442                return false;
 443        if (h1 == NULL || h2 == NULL)
 444                return true;
 445        if (h1->hdrlen != h2->hdrlen)
 446                return true;
 447        return memcmp(h1+1, h2+1, ((h1->hdrlen+1)<<3) - sizeof(*h1));
 448}
 449
 450static bool ipv6_opt_cmp(struct ipv6_txoptions *o1, struct ipv6_txoptions *o2)
 451{
 452        if (o1 == o2)
 453                return false;
 454        if (o1 == NULL || o2 == NULL)
 455                return true;
 456        if (o1->opt_nflen != o2->opt_nflen)
 457                return true;
 458        if (ipv6_hdr_cmp(o1->hopopt, o2->hopopt))
 459                return true;
 460        if (ipv6_hdr_cmp(o1->dst0opt, o2->dst0opt))
 461                return true;
 462        if (ipv6_hdr_cmp((struct ipv6_opt_hdr *)o1->srcrt, (struct ipv6_opt_hdr *)o2->srcrt))
 463                return true;
 464        return false;
 465}
 466
 467static inline void fl_link(struct ipv6_pinfo *np, struct ipv6_fl_socklist *sfl,
 468                struct ip6_flowlabel *fl)
 469{
 470        write_lock_bh(&ip6_sk_fl_lock);
 471        sfl->fl = fl;
 472        sfl->next = np->ipv6_fl_list;
 473        np->ipv6_fl_list = sfl;
 474        write_unlock_bh(&ip6_sk_fl_lock);
 475}
 476
 477int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen)
 478{
 479        int uninitialized_var(err);
 480        struct net *net = sock_net(sk);
 481        struct ipv6_pinfo *np = inet6_sk(sk);
 482        struct in6_flowlabel_req freq;
 483        struct ipv6_fl_socklist *sfl1=NULL;
 484        struct ipv6_fl_socklist *sfl, **sflp;
 485        struct ip6_flowlabel *fl, *fl1 = NULL;
 486
 487
 488        if (optlen < sizeof(freq))
 489                return -EINVAL;
 490
 491        if (copy_from_user(&freq, optval, sizeof(freq)))
 492                return -EFAULT;
 493
 494        switch (freq.flr_action) {
 495        case IPV6_FL_A_PUT:
 496                write_lock_bh(&ip6_sk_fl_lock);
 497                for (sflp = &np->ipv6_fl_list; (sfl=*sflp)!=NULL; sflp = &sfl->next) {
 498                        if (sfl->fl->label == freq.flr_label) {
 499                                if (freq.flr_label == (np->flow_label&IPV6_FLOWLABEL_MASK))
 500                                        np->flow_label &= ~IPV6_FLOWLABEL_MASK;
 501                                *sflp = sfl->next;
 502                                write_unlock_bh(&ip6_sk_fl_lock);
 503                                fl_release(sfl->fl);
 504                                kfree(sfl);
 505                                return 0;
 506                        }
 507                }
 508                write_unlock_bh(&ip6_sk_fl_lock);
 509                return -ESRCH;
 510
 511        case IPV6_FL_A_RENEW:
 512                read_lock_bh(&ip6_sk_fl_lock);
 513                for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next) {
 514                        if (sfl->fl->label == freq.flr_label) {
 515                                err = fl6_renew(sfl->fl, freq.flr_linger, freq.flr_expires);
 516                                read_unlock_bh(&ip6_sk_fl_lock);
 517                                return err;
 518                        }
 519                }
 520                read_unlock_bh(&ip6_sk_fl_lock);
 521
 522                if (freq.flr_share == IPV6_FL_S_NONE && capable(CAP_NET_ADMIN)) {
 523                        fl = fl_lookup(net, freq.flr_label);
 524                        if (fl) {
 525                                err = fl6_renew(fl, freq.flr_linger, freq.flr_expires);
 526                                fl_release(fl);
 527                                return err;
 528                        }
 529                }
 530                return -ESRCH;
 531
 532        case IPV6_FL_A_GET:
 533                if (freq.flr_label & ~IPV6_FLOWLABEL_MASK)
 534                        return -EINVAL;
 535
 536                fl = fl_create(net, sk, &freq, optval, optlen, &err);
 537                if (fl == NULL)
 538                        return err;
 539                sfl1 = kmalloc(sizeof(*sfl1), GFP_KERNEL);
 540
 541                if (freq.flr_label) {
 542                        err = -EEXIST;
 543                        read_lock_bh(&ip6_sk_fl_lock);
 544                        for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next) {
 545                                if (sfl->fl->label == freq.flr_label) {
 546                                        if (freq.flr_flags&IPV6_FL_F_EXCL) {
 547                                                read_unlock_bh(&ip6_sk_fl_lock);
 548                                                goto done;
 549                                        }
 550                                        fl1 = sfl->fl;
 551                                        atomic_inc(&fl1->users);
 552                                        break;
 553                                }
 554                        }
 555                        read_unlock_bh(&ip6_sk_fl_lock);
 556
 557                        if (fl1 == NULL)
 558                                fl1 = fl_lookup(net, freq.flr_label);
 559                        if (fl1) {
 560recheck:
 561                                err = -EEXIST;
 562                                if (freq.flr_flags&IPV6_FL_F_EXCL)
 563                                        goto release;
 564                                err = -EPERM;
 565                                if (fl1->share == IPV6_FL_S_EXCL ||
 566                                    fl1->share != fl->share ||
 567                                    ((fl1->share == IPV6_FL_S_PROCESS) &&
 568                                     (fl1->owner.pid == fl->owner.pid)) ||
 569                                    ((fl1->share == IPV6_FL_S_USER) &&
 570                                     uid_eq(fl1->owner.uid, fl->owner.uid)))
 571                                        goto release;
 572
 573                                err = -EINVAL;
 574                                if (!ipv6_addr_equal(&fl1->dst, &fl->dst) ||
 575                                    ipv6_opt_cmp(fl1->opt, fl->opt))
 576                                        goto release;
 577
 578                                err = -ENOMEM;
 579                                if (sfl1 == NULL)
 580                                        goto release;
 581                                if (fl->linger > fl1->linger)
 582                                        fl1->linger = fl->linger;
 583                                if ((long)(fl->expires - fl1->expires) > 0)
 584                                        fl1->expires = fl->expires;
 585                                fl_link(np, sfl1, fl1);
 586                                fl_free(fl);
 587                                return 0;
 588
 589release:
 590                                fl_release(fl1);
 591                                goto done;
 592                        }
 593                }
 594                err = -ENOENT;
 595                if (!(freq.flr_flags&IPV6_FL_F_CREATE))
 596                        goto done;
 597
 598                err = -ENOMEM;
 599                if (sfl1 == NULL || (err = mem_check(sk)) != 0)
 600                        goto done;
 601
 602                fl1 = fl_intern(net, fl, freq.flr_label);
 603                if (fl1 != NULL)
 604                        goto recheck;
 605
 606                if (!freq.flr_label) {
 607                        if (copy_to_user(&((struct in6_flowlabel_req __user *) optval)->flr_label,
 608                                         &fl->label, sizeof(fl->label))) {
 609                                /* Intentionally ignore fault. */
 610                        }
 611                }
 612
 613                fl_link(np, sfl1, fl);
 614                return 0;
 615
 616        default:
 617                return -EINVAL;
 618        }
 619
 620done:
 621        fl_free(fl);
 622        kfree(sfl1);
 623        return err;
 624}
 625
 626#ifdef CONFIG_PROC_FS
 627
 628struct ip6fl_iter_state {
 629        struct seq_net_private p;
 630        struct pid_namespace *pid_ns;
 631        int bucket;
 632};
 633
 634#define ip6fl_seq_private(seq)  ((struct ip6fl_iter_state *)(seq)->private)
 635
 636static struct ip6_flowlabel *ip6fl_get_first(struct seq_file *seq)
 637{
 638        struct ip6_flowlabel *fl = NULL;
 639        struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 640        struct net *net = seq_file_net(seq);
 641
 642        for (state->bucket = 0; state->bucket <= FL_HASH_MASK; ++state->bucket) {
 643                fl = fl_ht[state->bucket];
 644
 645                while (fl && !net_eq(fl->fl_net, net))
 646                        fl = fl->next;
 647                if (fl)
 648                        break;
 649        }
 650        return fl;
 651}
 652
 653static struct ip6_flowlabel *ip6fl_get_next(struct seq_file *seq, struct ip6_flowlabel *fl)
 654{
 655        struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 656        struct net *net = seq_file_net(seq);
 657
 658        fl = fl->next;
 659try_again:
 660        while (fl && !net_eq(fl->fl_net, net))
 661                fl = fl->next;
 662
 663        while (!fl) {
 664                if (++state->bucket <= FL_HASH_MASK) {
 665                        fl = fl_ht[state->bucket];
 666                        goto try_again;
 667                } else
 668                        break;
 669        }
 670        return fl;
 671}
 672
 673static struct ip6_flowlabel *ip6fl_get_idx(struct seq_file *seq, loff_t pos)
 674{
 675        struct ip6_flowlabel *fl = ip6fl_get_first(seq);
 676        if (fl)
 677                while (pos && (fl = ip6fl_get_next(seq, fl)) != NULL)
 678                        --pos;
 679        return pos ? NULL : fl;
 680}
 681
 682static void *ip6fl_seq_start(struct seq_file *seq, loff_t *pos)
 683        __acquires(ip6_fl_lock)
 684{
 685        read_lock_bh(&ip6_fl_lock);
 686        return *pos ? ip6fl_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
 687}
 688
 689static void *ip6fl_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 690{
 691        struct ip6_flowlabel *fl;
 692
 693        if (v == SEQ_START_TOKEN)
 694                fl = ip6fl_get_first(seq);
 695        else
 696                fl = ip6fl_get_next(seq, v);
 697        ++*pos;
 698        return fl;
 699}
 700
 701static void ip6fl_seq_stop(struct seq_file *seq, void *v)
 702        __releases(ip6_fl_lock)
 703{
 704        read_unlock_bh(&ip6_fl_lock);
 705}
 706
 707static int ip6fl_seq_show(struct seq_file *seq, void *v)
 708{
 709        struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 710        if (v == SEQ_START_TOKEN)
 711                seq_printf(seq, "%-5s %-1s %-6s %-6s %-6s %-8s %-32s %s\n",
 712                           "Label", "S", "Owner", "Users", "Linger", "Expires", "Dst", "Opt");
 713        else {
 714                struct ip6_flowlabel *fl = v;
 715                seq_printf(seq,
 716                           "%05X %-1d %-6d %-6d %-6ld %-8ld %pi6 %-4d\n",
 717                           (unsigned int)ntohl(fl->label),
 718                           fl->share,
 719                           ((fl->share == IPV6_FL_S_PROCESS) ?
 720                            pid_nr_ns(fl->owner.pid, state->pid_ns) :
 721                            ((fl->share == IPV6_FL_S_USER) ?
 722                             from_kuid_munged(seq_user_ns(seq), fl->owner.uid) :
 723                             0)),
 724                           atomic_read(&fl->users),
 725                           fl->linger/HZ,
 726                           (long)(fl->expires - jiffies)/HZ,
 727                           &fl->dst,
 728                           fl->opt ? fl->opt->opt_nflen : 0);
 729        }
 730        return 0;
 731}
 732
 733static const struct seq_operations ip6fl_seq_ops = {
 734        .start  =       ip6fl_seq_start,
 735        .next   =       ip6fl_seq_next,
 736        .stop   =       ip6fl_seq_stop,
 737        .show   =       ip6fl_seq_show,
 738};
 739
 740static int ip6fl_seq_open(struct inode *inode, struct file *file)
 741{
 742        struct seq_file *seq;
 743        struct ip6fl_iter_state *state;
 744        int err;
 745
 746        err = seq_open_net(inode, file, &ip6fl_seq_ops,
 747                           sizeof(struct ip6fl_iter_state));
 748
 749        if (!err) {
 750                seq = file->private_data;
 751                state = ip6fl_seq_private(seq);
 752                rcu_read_lock();
 753                state->pid_ns = get_pid_ns(task_active_pid_ns(current));
 754                rcu_read_unlock();
 755        }
 756        return err;
 757}
 758
 759static int ip6fl_seq_release(struct inode *inode, struct file *file)
 760{
 761        struct seq_file *seq = file->private_data;
 762        struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 763        put_pid_ns(state->pid_ns);
 764        return seq_release_net(inode, file);
 765}
 766
 767static const struct file_operations ip6fl_seq_fops = {
 768        .owner          =       THIS_MODULE,
 769        .open           =       ip6fl_seq_open,
 770        .read           =       seq_read,
 771        .llseek         =       seq_lseek,
 772        .release        =       ip6fl_seq_release,
 773};
 774
 775static int __net_init ip6_flowlabel_proc_init(struct net *net)
 776{
 777        if (!proc_net_fops_create(net, "ip6_flowlabel",
 778                                  S_IRUGO, &ip6fl_seq_fops))
 779                return -ENOMEM;
 780        return 0;
 781}
 782
 783static void __net_exit ip6_flowlabel_proc_fini(struct net *net)
 784{
 785        proc_net_remove(net, "ip6_flowlabel");
 786}
 787#else
 788static inline int ip6_flowlabel_proc_init(struct net *net)
 789{
 790        return 0;
 791}
 792static inline void ip6_flowlabel_proc_fini(struct net *net)
 793{
 794}
 795#endif
 796
 797static void __net_exit ip6_flowlabel_net_exit(struct net *net)
 798{
 799        ip6_fl_purge(net);
 800        ip6_flowlabel_proc_fini(net);
 801}
 802
 803static struct pernet_operations ip6_flowlabel_net_ops = {
 804        .init = ip6_flowlabel_proc_init,
 805        .exit = ip6_flowlabel_net_exit,
 806};
 807
 808int ip6_flowlabel_init(void)
 809{
 810        return register_pernet_subsys(&ip6_flowlabel_net_ops);
 811}
 812
 813void ip6_flowlabel_cleanup(void)
 814{
 815        del_timer(&ip6_fl_gc_timer);
 816        unregister_pernet_subsys(&ip6_flowlabel_net_ops);
 817}
 818
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