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/in6.h>
  19#include <linux/proc_fs.h>
  20#include <linux/seq_file.h>
  21#include <linux/slab.h>
  22#include <linux/export.h>
  23#include <linux/pid_namespace.h>
  24
  25#include <net/net_namespace.h>
  26#include <net/sock.h>
  27
  28#include <net/ipv6.h>
  29#include <net/rawv6.h>
  30#include <net/transp_v6.h>
  31
  32#include <asm/uaccess.h>
  33
  34#define FL_MIN_LINGER   6       /* Minimal linger. It is set to 6sec specified
  35                                   in old IPv6 RFC. Well, it was reasonable value.
  36                                 */
  37#define FL_MAX_LINGER   150     /* Maximal linger timeout */
  38
  39/* FL hash table */
  40
  41#define FL_MAX_PER_SOCK 32
  42#define FL_MAX_SIZE     4096
  43#define FL_HASH_MASK    255
  44#define FL_HASH(l)      (ntohl(l)&FL_HASH_MASK)
  45
  46static atomic_t fl_size = ATOMIC_INIT(0);
  47static struct ip6_flowlabel __rcu *fl_ht[FL_HASH_MASK+1];
  48
  49static void ip6_fl_gc(unsigned long dummy);
  50static DEFINE_TIMER(ip6_fl_gc_timer, ip6_fl_gc, 0, 0);
  51
  52/* FL hash table lock: it protects only of GC */
  53
  54static DEFINE_SPINLOCK(ip6_fl_lock);
  55
  56/* Big socket sock */
  57
  58static DEFINE_SPINLOCK(ip6_sk_fl_lock);
  59
  60#define for_each_fl_rcu(hash, fl)                               \
  61        for (fl = rcu_dereference_bh(fl_ht[(hash)]);            \
  62             fl != NULL;                                        \
  63             fl = rcu_dereference_bh(fl->next))
  64#define for_each_fl_continue_rcu(fl)                            \
  65        for (fl = rcu_dereference_bh(fl->next);                 \
  66             fl != NULL;                                        \
  67             fl = rcu_dereference_bh(fl->next))
  68
  69#define for_each_sk_fl_rcu(np, sfl)                             \
  70        for (sfl = rcu_dereference_bh(np->ipv6_fl_list);        \
  71             sfl != NULL;                                       \
  72             sfl = rcu_dereference_bh(sfl->next))
  73
  74static inline struct ip6_flowlabel *__fl_lookup(struct net *net, __be32 label)
  75{
  76        struct ip6_flowlabel *fl;
  77
  78        for_each_fl_rcu(FL_HASH(label), fl) {
  79                if (fl->label == label && net_eq(fl->fl_net, net))
  80                        return fl;
  81        }
  82        return NULL;
  83}
  84
  85static struct ip6_flowlabel *fl_lookup(struct net *net, __be32 label)
  86{
  87        struct ip6_flowlabel *fl;
  88
  89        rcu_read_lock_bh();
  90        fl = __fl_lookup(net, label);
  91        if (fl && !atomic_inc_not_zero(&fl->users))
  92                fl = NULL;
  93        rcu_read_unlock_bh();
  94        return fl;
  95}
  96
  97
  98static void fl_free(struct ip6_flowlabel *fl)
  99{
 100        if (fl) {
 101                if (fl->share == IPV6_FL_S_PROCESS)
 102                        put_pid(fl->owner.pid);
 103                release_net(fl->fl_net);
 104                kfree(fl->opt);
 105                kfree_rcu(fl, rcu);
 106        }
 107}
 108
 109static void fl_release(struct ip6_flowlabel *fl)
 110{
 111        spin_lock_bh(&ip6_fl_lock);
 112
 113        fl->lastuse = jiffies;
 114        if (atomic_dec_and_test(&fl->users)) {
 115                unsigned long ttd = fl->lastuse + fl->linger;
 116                if (time_after(ttd, fl->expires))
 117                        fl->expires = ttd;
 118                ttd = fl->expires;
 119                if (fl->opt && fl->share == IPV6_FL_S_EXCL) {
 120                        struct ipv6_txoptions *opt = fl->opt;
 121                        fl->opt = NULL;
 122                        kfree(opt);
 123                }
 124                if (!timer_pending(&ip6_fl_gc_timer) ||
 125                    time_after(ip6_fl_gc_timer.expires, ttd))
 126                        mod_timer(&ip6_fl_gc_timer, ttd);
 127        }
 128        spin_unlock_bh(&ip6_fl_lock);
 129}
 130
 131static void ip6_fl_gc(unsigned long dummy)
 132{
 133        int i;
 134        unsigned long now = jiffies;
 135        unsigned long sched = 0;
 136
 137        spin_lock(&ip6_fl_lock);
 138
 139        for (i = 0; i <= FL_HASH_MASK; i++) {
 140                struct ip6_flowlabel *fl;
 141                struct ip6_flowlabel __rcu **flp;
 142
 143                flp = &fl_ht[i];
 144                while ((fl = rcu_dereference_protected(*flp,
 145                                                       lockdep_is_held(&ip6_fl_lock))) != NULL) {
 146                        if (atomic_read(&fl->users) == 0) {
 147                                unsigned long ttd = fl->lastuse + fl->linger;
 148                                if (time_after(ttd, fl->expires))
 149                                        fl->expires = ttd;
 150                                ttd = fl->expires;
 151                                if (time_after_eq(now, ttd)) {
 152                                        *flp = fl->next;
 153                                        fl_free(fl);
 154                                        atomic_dec(&fl_size);
 155                                        continue;
 156                                }
 157                                if (!sched || time_before(ttd, sched))
 158                                        sched = ttd;
 159                        }
 160                        flp = &fl->next;
 161                }
 162        }
 163        if (!sched && atomic_read(&fl_size))
 164                sched = now + FL_MAX_LINGER;
 165        if (sched) {
 166                mod_timer(&ip6_fl_gc_timer, sched);
 167        }
 168        spin_unlock(&ip6_fl_lock);
 169}
 170
 171static void __net_exit ip6_fl_purge(struct net *net)
 172{
 173        int i;
 174
 175        spin_lock_bh(&ip6_fl_lock);
 176        for (i = 0; i <= FL_HASH_MASK; i++) {
 177                struct ip6_flowlabel *fl;
 178                struct ip6_flowlabel __rcu **flp;
 179
 180                flp = &fl_ht[i];
 181                while ((fl = rcu_dereference_protected(*flp,
 182                                                       lockdep_is_held(&ip6_fl_lock))) != NULL) {
 183                        if (net_eq(fl->fl_net, net) &&
 184                            atomic_read(&fl->users) == 0) {
 185                                *flp = fl->next;
 186                                fl_free(fl);
 187                                atomic_dec(&fl_size);
 188                                continue;
 189                        }
 190                        flp = &fl->next;
 191                }
 192        }
 193        spin_unlock_bh(&ip6_fl_lock);
 194}
 195
 196static struct ip6_flowlabel *fl_intern(struct net *net,
 197                                       struct ip6_flowlabel *fl, __be32 label)
 198{
 199        struct ip6_flowlabel *lfl;
 200
 201        fl->label = label & IPV6_FLOWLABEL_MASK;
 202
 203        spin_lock_bh(&ip6_fl_lock);
 204        if (label == 0) {
 205                for (;;) {
 206                        fl->label = htonl(prandom_u32())&IPV6_FLOWLABEL_MASK;
 207                        if (fl->label) {
 208                                lfl = __fl_lookup(net, fl->label);
 209                                if (lfl == NULL)
 210                                        break;
 211                        }
 212                }
 213        } else {
 214                /*
 215                 * we dropper the ip6_fl_lock, so this entry could reappear
 216                 * and we need to recheck with it.
 217                 *
 218                 * OTOH no need to search the active socket first, like it is
 219                 * done in ipv6_flowlabel_opt - sock is locked, so new entry
 220                 * with the same label can only appear on another sock
 221                 */
 222                lfl = __fl_lookup(net, fl->label);
 223                if (lfl != NULL) {
 224                        atomic_inc(&lfl->users);
 225                        spin_unlock_bh(&ip6_fl_lock);
 226                        return lfl;
 227                }
 228        }
 229
 230        fl->lastuse = jiffies;
 231        fl->next = fl_ht[FL_HASH(fl->label)];
 232        rcu_assign_pointer(fl_ht[FL_HASH(fl->label)], fl);
 233        atomic_inc(&fl_size);
 234        spin_unlock_bh(&ip6_fl_lock);
 235        return NULL;
 236}
 237
 238
 239
 240/* Socket flowlabel lists */
 241
 242struct ip6_flowlabel *fl6_sock_lookup(struct sock *sk, __be32 label)
 243{
 244        struct ipv6_fl_socklist *sfl;
 245        struct ipv6_pinfo *np = inet6_sk(sk);
 246
 247        label &= IPV6_FLOWLABEL_MASK;
 248
 249        rcu_read_lock_bh();
 250        for_each_sk_fl_rcu(np, sfl) {
 251                struct ip6_flowlabel *fl = sfl->fl;
 252                if (fl->label == label) {
 253                        fl->lastuse = jiffies;
 254                        atomic_inc(&fl->users);
 255                        rcu_read_unlock_bh();
 256                        return fl;
 257                }
 258        }
 259        rcu_read_unlock_bh();
 260        return NULL;
 261}
 262EXPORT_SYMBOL_GPL(fl6_sock_lookup);
 263
 264void fl6_free_socklist(struct sock *sk)
 265{
 266        struct ipv6_pinfo *np = inet6_sk(sk);
 267        struct ipv6_fl_socklist *sfl;
 268
 269        if (!rcu_access_pointer(np->ipv6_fl_list))
 270                return;
 271
 272        spin_lock_bh(&ip6_sk_fl_lock);
 273        while ((sfl = rcu_dereference_protected(np->ipv6_fl_list,
 274                                                lockdep_is_held(&ip6_sk_fl_lock))) != NULL) {
 275                np->ipv6_fl_list = sfl->next;
 276                spin_unlock_bh(&ip6_sk_fl_lock);
 277
 278                fl_release(sfl->fl);
 279                kfree_rcu(sfl, rcu);
 280
 281                spin_lock_bh(&ip6_sk_fl_lock);
 282        }
 283        spin_unlock_bh(&ip6_sk_fl_lock);
 284}
 285
 286/* Service routines */
 287
 288
 289/*
 290   It is the only difficult place. flowlabel enforces equal headers
 291   before and including routing header, however user may supply options
 292   following rthdr.
 293 */
 294
 295struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions *opt_space,
 296                                         struct ip6_flowlabel *fl,
 297                                         struct ipv6_txoptions *fopt)
 298{
 299        struct ipv6_txoptions *fl_opt = fl->opt;
 300
 301        if (fopt == NULL || fopt->opt_flen == 0)
 302                return fl_opt;
 303
 304        if (fl_opt != NULL) {
 305                opt_space->hopopt = fl_opt->hopopt;
 306                opt_space->dst0opt = fl_opt->dst0opt;
 307                opt_space->srcrt = fl_opt->srcrt;
 308                opt_space->opt_nflen = fl_opt->opt_nflen;
 309        } else {
 310                if (fopt->opt_nflen == 0)
 311                        return fopt;
 312                opt_space->hopopt = NULL;
 313                opt_space->dst0opt = NULL;
 314                opt_space->srcrt = NULL;
 315                opt_space->opt_nflen = 0;
 316        }
 317        opt_space->dst1opt = fopt->dst1opt;
 318        opt_space->opt_flen = fopt->opt_flen;
 319        return opt_space;
 320}
 321EXPORT_SYMBOL_GPL(fl6_merge_options);
 322
 323static unsigned long check_linger(unsigned long ttl)
 324{
 325        if (ttl < FL_MIN_LINGER)
 326                return FL_MIN_LINGER*HZ;
 327        if (ttl > FL_MAX_LINGER && !capable(CAP_NET_ADMIN))
 328                return 0;
 329        return ttl*HZ;
 330}
 331
 332static int fl6_renew(struct ip6_flowlabel *fl, unsigned long linger, unsigned long expires)
 333{
 334        linger = check_linger(linger);
 335        if (!linger)
 336                return -EPERM;
 337        expires = check_linger(expires);
 338        if (!expires)
 339                return -EPERM;
 340
 341        spin_lock_bh(&ip6_fl_lock);
 342        fl->lastuse = jiffies;
 343        if (time_before(fl->linger, linger))
 344                fl->linger = linger;
 345        if (time_before(expires, fl->linger))
 346                expires = fl->linger;
 347        if (time_before(fl->expires, fl->lastuse + expires))
 348                fl->expires = fl->lastuse + expires;
 349        spin_unlock_bh(&ip6_fl_lock);
 350
 351        return 0;
 352}
 353
 354static struct ip6_flowlabel *
 355fl_create(struct net *net, struct sock *sk, struct in6_flowlabel_req *freq,
 356          char __user *optval, int optlen, int *err_p)
 357{
 358        struct ip6_flowlabel *fl = NULL;
 359        int olen;
 360        int addr_type;
 361        int err;
 362
 363        olen = optlen - CMSG_ALIGN(sizeof(*freq));
 364        err = -EINVAL;
 365        if (olen > 64 * 1024)
 366                goto done;
 367
 368        err = -ENOMEM;
 369        fl = kzalloc(sizeof(*fl), GFP_KERNEL);
 370        if (fl == NULL)
 371                goto done;
 372
 373        if (olen > 0) {
 374                struct msghdr msg;
 375                struct flowi6 flowi6;
 376                int junk;
 377
 378                err = -ENOMEM;
 379                fl->opt = kmalloc(sizeof(*fl->opt) + olen, GFP_KERNEL);
 380                if (fl->opt == NULL)
 381                        goto done;
 382
 383                memset(fl->opt, 0, sizeof(*fl->opt));
 384                fl->opt->tot_len = sizeof(*fl->opt) + olen;
 385                err = -EFAULT;
 386                if (copy_from_user(fl->opt+1, optval+CMSG_ALIGN(sizeof(*freq)), olen))
 387                        goto done;
 388
 389                msg.msg_controllen = olen;
 390                msg.msg_control = (void *)(fl->opt+1);
 391                memset(&flowi6, 0, sizeof(flowi6));
 392
 393                err = ip6_datagram_send_ctl(net, sk, &msg, &flowi6, fl->opt,
 394                                            &junk, &junk, &junk);
 395                if (err)
 396                        goto done;
 397                err = -EINVAL;
 398                if (fl->opt->opt_flen)
 399                        goto done;
 400                if (fl->opt->opt_nflen == 0) {
 401                        kfree(fl->opt);
 402                        fl->opt = NULL;
 403                }
 404        }
 405
 406        fl->fl_net = hold_net(net);
 407        fl->expires = jiffies;
 408        err = fl6_renew(fl, freq->flr_linger, freq->flr_expires);
 409        if (err)
 410                goto done;
 411        fl->share = freq->flr_share;
 412        addr_type = ipv6_addr_type(&freq->flr_dst);
 413        if ((addr_type & IPV6_ADDR_MAPPED) ||
 414            addr_type == IPV6_ADDR_ANY) {
 415                err = -EINVAL;
 416                goto done;
 417        }
 418        fl->dst = freq->flr_dst;
 419        atomic_set(&fl->users, 1);
 420        switch (fl->share) {
 421        case IPV6_FL_S_EXCL:
 422        case IPV6_FL_S_ANY:
 423                break;
 424        case IPV6_FL_S_PROCESS:
 425                fl->owner.pid = get_task_pid(current, PIDTYPE_PID);
 426                break;
 427        case IPV6_FL_S_USER:
 428                fl->owner.uid = current_euid();
 429                break;
 430        default:
 431                err = -EINVAL;
 432                goto done;
 433        }
 434        return fl;
 435
 436done:
 437        fl_free(fl);
 438        *err_p = err;
 439        return NULL;
 440}
 441
 442static int mem_check(struct sock *sk)
 443{
 444        struct ipv6_pinfo *np = inet6_sk(sk);
 445        struct ipv6_fl_socklist *sfl;
 446        int room = FL_MAX_SIZE - atomic_read(&fl_size);
 447        int count = 0;
 448
 449        if (room > FL_MAX_SIZE - FL_MAX_PER_SOCK)
 450                return 0;
 451
 452        rcu_read_lock_bh();
 453        for_each_sk_fl_rcu(np, sfl)
 454                count++;
 455        rcu_read_unlock_bh();
 456
 457        if (room <= 0 ||
 458            ((count >= FL_MAX_PER_SOCK ||
 459              (count > 0 && room < FL_MAX_SIZE/2) || room < FL_MAX_SIZE/4) &&
 460             !capable(CAP_NET_ADMIN)))
 461                return -ENOBUFS;
 462
 463        return 0;
 464}
 465
 466static inline void fl_link(struct ipv6_pinfo *np, struct ipv6_fl_socklist *sfl,
 467                struct ip6_flowlabel *fl)
 468{
 469        spin_lock_bh(&ip6_sk_fl_lock);
 470        sfl->fl = fl;
 471        sfl->next = np->ipv6_fl_list;
 472        rcu_assign_pointer(np->ipv6_fl_list, sfl);
 473        spin_unlock_bh(&ip6_sk_fl_lock);
 474}
 475
 476int ipv6_flowlabel_opt_get(struct sock *sk, struct in6_flowlabel_req *freq,
 477                           int flags)
 478{
 479        struct ipv6_pinfo *np = inet6_sk(sk);
 480        struct ipv6_fl_socklist *sfl;
 481
 482        if (flags & IPV6_FL_F_REMOTE) {
 483                freq->flr_label = np->rcv_flowinfo & IPV6_FLOWLABEL_MASK;
 484                return 0;
 485        }
 486
 487        if (np->repflow) {
 488                freq->flr_label = np->flow_label;
 489                return 0;
 490        }
 491
 492        rcu_read_lock_bh();
 493
 494        for_each_sk_fl_rcu(np, sfl) {
 495                if (sfl->fl->label == (np->flow_label & IPV6_FLOWLABEL_MASK)) {
 496                        spin_lock_bh(&ip6_fl_lock);
 497                        freq->flr_label = sfl->fl->label;
 498                        freq->flr_dst = sfl->fl->dst;
 499                        freq->flr_share = sfl->fl->share;
 500                        freq->flr_expires = (sfl->fl->expires - jiffies) / HZ;
 501                        freq->flr_linger = sfl->fl->linger / HZ;
 502
 503                        spin_unlock_bh(&ip6_fl_lock);
 504                        rcu_read_unlock_bh();
 505                        return 0;
 506                }
 507        }
 508        rcu_read_unlock_bh();
 509
 510        return -ENOENT;
 511}
 512
 513int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen)
 514{
 515        int uninitialized_var(err);
 516        struct net *net = sock_net(sk);
 517        struct ipv6_pinfo *np = inet6_sk(sk);
 518        struct in6_flowlabel_req freq;
 519        struct ipv6_fl_socklist *sfl1 = NULL;
 520        struct ipv6_fl_socklist *sfl;
 521        struct ipv6_fl_socklist __rcu **sflp;
 522        struct ip6_flowlabel *fl, *fl1 = NULL;
 523
 524
 525        if (optlen < sizeof(freq))
 526                return -EINVAL;
 527
 528        if (copy_from_user(&freq, optval, sizeof(freq)))
 529                return -EFAULT;
 530
 531        switch (freq.flr_action) {
 532        case IPV6_FL_A_PUT:
 533                if (freq.flr_flags & IPV6_FL_F_REFLECT) {
 534                        if (sk->sk_protocol != IPPROTO_TCP)
 535                                return -ENOPROTOOPT;
 536                        if (!np->repflow)
 537                                return -ESRCH;
 538                        np->flow_label = 0;
 539                        np->repflow = 0;
 540                        return 0;
 541                }
 542                spin_lock_bh(&ip6_sk_fl_lock);
 543                for (sflp = &np->ipv6_fl_list;
 544                     (sfl = rcu_dereference(*sflp)) != NULL;
 545                     sflp = &sfl->next) {
 546                        if (sfl->fl->label == freq.flr_label) {
 547                                if (freq.flr_label == (np->flow_label&IPV6_FLOWLABEL_MASK))
 548                                        np->flow_label &= ~IPV6_FLOWLABEL_MASK;
 549                                *sflp = rcu_dereference(sfl->next);
 550                                spin_unlock_bh(&ip6_sk_fl_lock);
 551                                fl_release(sfl->fl);
 552                                kfree_rcu(sfl, rcu);
 553                                return 0;
 554                        }
 555                }
 556                spin_unlock_bh(&ip6_sk_fl_lock);
 557                return -ESRCH;
 558
 559        case IPV6_FL_A_RENEW:
 560                rcu_read_lock_bh();
 561                for_each_sk_fl_rcu(np, sfl) {
 562                        if (sfl->fl->label == freq.flr_label) {
 563                                err = fl6_renew(sfl->fl, freq.flr_linger, freq.flr_expires);
 564                                rcu_read_unlock_bh();
 565                                return err;
 566                        }
 567                }
 568                rcu_read_unlock_bh();
 569
 570                if (freq.flr_share == IPV6_FL_S_NONE &&
 571                    ns_capable(net->user_ns, CAP_NET_ADMIN)) {
 572                        fl = fl_lookup(net, freq.flr_label);
 573                        if (fl) {
 574                                err = fl6_renew(fl, freq.flr_linger, freq.flr_expires);
 575                                fl_release(fl);
 576                                return err;
 577                        }
 578                }
 579                return -ESRCH;
 580
 581        case IPV6_FL_A_GET:
 582                if (freq.flr_flags & IPV6_FL_F_REFLECT) {
 583                        struct net *net = sock_net(sk);
 584                        if (net->ipv6.sysctl.flowlabel_consistency) {
 585                                net_info_ratelimited("Can not set IPV6_FL_F_REFLECT if flowlabel_consistency sysctl is enable\n");
 586                                return -EPERM;
 587                        }
 588
 589                        if (sk->sk_protocol != IPPROTO_TCP)
 590                                return -ENOPROTOOPT;
 591
 592                        np->repflow = 1;
 593                        return 0;
 594                }
 595
 596                if (freq.flr_label & ~IPV6_FLOWLABEL_MASK)
 597                        return -EINVAL;
 598
 599                fl = fl_create(net, sk, &freq, optval, optlen, &err);
 600                if (fl == NULL)
 601                        return err;
 602                sfl1 = kmalloc(sizeof(*sfl1), GFP_KERNEL);
 603
 604                if (freq.flr_label) {
 605                        err = -EEXIST;
 606                        rcu_read_lock_bh();
 607                        for_each_sk_fl_rcu(np, sfl) {
 608                                if (sfl->fl->label == freq.flr_label) {
 609                                        if (freq.flr_flags&IPV6_FL_F_EXCL) {
 610                                                rcu_read_unlock_bh();
 611                                                goto done;
 612                                        }
 613                                        fl1 = sfl->fl;
 614                                        atomic_inc(&fl1->users);
 615                                        break;
 616                                }
 617                        }
 618                        rcu_read_unlock_bh();
 619
 620                        if (fl1 == NULL)
 621                                fl1 = fl_lookup(net, freq.flr_label);
 622                        if (fl1) {
 623recheck:
 624                                err = -EEXIST;
 625                                if (freq.flr_flags&IPV6_FL_F_EXCL)
 626                                        goto release;
 627                                err = -EPERM;
 628                                if (fl1->share == IPV6_FL_S_EXCL ||
 629                                    fl1->share != fl->share ||
 630                                    ((fl1->share == IPV6_FL_S_PROCESS) &&
 631                                     (fl1->owner.pid == fl->owner.pid)) ||
 632                                    ((fl1->share == IPV6_FL_S_USER) &&
 633                                     uid_eq(fl1->owner.uid, fl->owner.uid)))
 634                                        goto release;
 635
 636                                err = -ENOMEM;
 637                                if (sfl1 == NULL)
 638                                        goto release;
 639                                if (fl->linger > fl1->linger)
 640                                        fl1->linger = fl->linger;
 641                                if ((long)(fl->expires - fl1->expires) > 0)
 642                                        fl1->expires = fl->expires;
 643                                fl_link(np, sfl1, fl1);
 644                                fl_free(fl);
 645                                return 0;
 646
 647release:
 648                                fl_release(fl1);
 649                                goto done;
 650                        }
 651                }
 652                err = -ENOENT;
 653                if (!(freq.flr_flags&IPV6_FL_F_CREATE))
 654                        goto done;
 655
 656                err = -ENOMEM;
 657                if (sfl1 == NULL)
 658                        goto done;
 659
 660                err = mem_check(sk);
 661                if (err != 0)
 662                        goto done;
 663
 664                fl1 = fl_intern(net, fl, freq.flr_label);
 665                if (fl1 != NULL)
 666                        goto recheck;
 667
 668                if (!freq.flr_label) {
 669                        if (copy_to_user(&((struct in6_flowlabel_req __user *) optval)->flr_label,
 670                                         &fl->label, sizeof(fl->label))) {
 671                                /* Intentionally ignore fault. */
 672                        }
 673                }
 674
 675                fl_link(np, sfl1, fl);
 676                return 0;
 677
 678        default:
 679                return -EINVAL;
 680        }
 681
 682done:
 683        fl_free(fl);
 684        kfree(sfl1);
 685        return err;
 686}
 687
 688#ifdef CONFIG_PROC_FS
 689
 690struct ip6fl_iter_state {
 691        struct seq_net_private p;
 692        struct pid_namespace *pid_ns;
 693        int bucket;
 694};
 695
 696#define ip6fl_seq_private(seq)  ((struct ip6fl_iter_state *)(seq)->private)
 697
 698static struct ip6_flowlabel *ip6fl_get_first(struct seq_file *seq)
 699{
 700        struct ip6_flowlabel *fl = NULL;
 701        struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 702        struct net *net = seq_file_net(seq);
 703
 704        for (state->bucket = 0; state->bucket <= FL_HASH_MASK; ++state->bucket) {
 705                for_each_fl_rcu(state->bucket, fl) {
 706                        if (net_eq(fl->fl_net, net))
 707                                goto out;
 708                }
 709        }
 710        fl = NULL;
 711out:
 712        return fl;
 713}
 714
 715static struct ip6_flowlabel *ip6fl_get_next(struct seq_file *seq, struct ip6_flowlabel *fl)
 716{
 717        struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 718        struct net *net = seq_file_net(seq);
 719
 720        for_each_fl_continue_rcu(fl) {
 721                if (net_eq(fl->fl_net, net))
 722                        goto out;
 723        }
 724
 725try_again:
 726        if (++state->bucket <= FL_HASH_MASK) {
 727                for_each_fl_rcu(state->bucket, fl) {
 728                        if (net_eq(fl->fl_net, net))
 729                                goto out;
 730                }
 731                goto try_again;
 732        }
 733        fl = NULL;
 734
 735out:
 736        return fl;
 737}
 738
 739static struct ip6_flowlabel *ip6fl_get_idx(struct seq_file *seq, loff_t pos)
 740{
 741        struct ip6_flowlabel *fl = ip6fl_get_first(seq);
 742        if (fl)
 743                while (pos && (fl = ip6fl_get_next(seq, fl)) != NULL)
 744                        --pos;
 745        return pos ? NULL : fl;
 746}
 747
 748static void *ip6fl_seq_start(struct seq_file *seq, loff_t *pos)
 749        __acquires(RCU)
 750{
 751        rcu_read_lock_bh();
 752        return *pos ? ip6fl_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
 753}
 754
 755static void *ip6fl_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 756{
 757        struct ip6_flowlabel *fl;
 758
 759        if (v == SEQ_START_TOKEN)
 760                fl = ip6fl_get_first(seq);
 761        else
 762                fl = ip6fl_get_next(seq, v);
 763        ++*pos;
 764        return fl;
 765}
 766
 767static void ip6fl_seq_stop(struct seq_file *seq, void *v)
 768        __releases(RCU)
 769{
 770        rcu_read_unlock_bh();
 771}
 772
 773static int ip6fl_seq_show(struct seq_file *seq, void *v)
 774{
 775        struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 776        if (v == SEQ_START_TOKEN) {
 777                seq_puts(seq, "Label S Owner  Users  Linger Expires  Dst                              Opt\n");
 778        } else {
 779                struct ip6_flowlabel *fl = v;
 780                seq_printf(seq,
 781                           "%05X %-1d %-6d %-6d %-6ld %-8ld %pi6 %-4d\n",
 782                           (unsigned int)ntohl(fl->label),
 783                           fl->share,
 784                           ((fl->share == IPV6_FL_S_PROCESS) ?
 785                            pid_nr_ns(fl->owner.pid, state->pid_ns) :
 786                            ((fl->share == IPV6_FL_S_USER) ?
 787                             from_kuid_munged(seq_user_ns(seq), fl->owner.uid) :
 788                             0)),
 789                           atomic_read(&fl->users),
 790                           fl->linger/HZ,
 791                           (long)(fl->expires - jiffies)/HZ,
 792                           &fl->dst,
 793                           fl->opt ? fl->opt->opt_nflen : 0);
 794        }
 795        return 0;
 796}
 797
 798static const struct seq_operations ip6fl_seq_ops = {
 799        .start  =       ip6fl_seq_start,
 800        .next   =       ip6fl_seq_next,
 801        .stop   =       ip6fl_seq_stop,
 802        .show   =       ip6fl_seq_show,
 803};
 804
 805static int ip6fl_seq_open(struct inode *inode, struct file *file)
 806{
 807        struct seq_file *seq;
 808        struct ip6fl_iter_state *state;
 809        int err;
 810
 811        err = seq_open_net(inode, file, &ip6fl_seq_ops,
 812                           sizeof(struct ip6fl_iter_state));
 813
 814        if (!err) {
 815                seq = file->private_data;
 816                state = ip6fl_seq_private(seq);
 817                rcu_read_lock();
 818                state->pid_ns = get_pid_ns(task_active_pid_ns(current));
 819                rcu_read_unlock();
 820        }
 821        return err;
 822}
 823
 824static int ip6fl_seq_release(struct inode *inode, struct file *file)
 825{
 826        struct seq_file *seq = file->private_data;
 827        struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 828        put_pid_ns(state->pid_ns);
 829        return seq_release_net(inode, file);
 830}
 831
 832static const struct file_operations ip6fl_seq_fops = {
 833        .owner          =       THIS_MODULE,
 834        .open           =       ip6fl_seq_open,
 835        .read           =       seq_read,
 836        .llseek         =       seq_lseek,
 837        .release        =       ip6fl_seq_release,
 838};
 839
 840static int __net_init ip6_flowlabel_proc_init(struct net *net)
 841{
 842        if (!proc_create("ip6_flowlabel", S_IRUGO, net->proc_net,
 843                         &ip6fl_seq_fops))
 844                return -ENOMEM;
 845        return 0;
 846}
 847
 848static void __net_exit ip6_flowlabel_proc_fini(struct net *net)
 849{
 850        remove_proc_entry("ip6_flowlabel", net->proc_net);
 851}
 852#else
 853static inline int ip6_flowlabel_proc_init(struct net *net)
 854{
 855        return 0;
 856}
 857static inline void ip6_flowlabel_proc_fini(struct net *net)
 858{
 859}
 860#endif
 861
 862static void __net_exit ip6_flowlabel_net_exit(struct net *net)
 863{
 864        ip6_fl_purge(net);
 865        ip6_flowlabel_proc_fini(net);
 866}
 867
 868static struct pernet_operations ip6_flowlabel_net_ops = {
 869        .init = ip6_flowlabel_proc_init,
 870        .exit = ip6_flowlabel_net_exit,
 871};
 872
 873int ip6_flowlabel_init(void)
 874{
 875        return register_pernet_subsys(&ip6_flowlabel_net_ops);
 876}
 877
 878void ip6_flowlabel_cleanup(void)
 879{
 880        del_timer(&ip6_fl_gc_timer);
 881        unregister_pernet_subsys(&ip6_flowlabel_net_ops);
 882}
 883