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 <linux/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                kfree(fl->opt);
 104                kfree_rcu(fl, rcu);
 105        }
 106}
 107
 108static void fl_release(struct ip6_flowlabel *fl)
 109{
 110        spin_lock_bh(&ip6_fl_lock);
 111
 112        fl->lastuse = jiffies;
 113        if (atomic_dec_and_test(&fl->users)) {
 114                unsigned long ttd = fl->lastuse + fl->linger;
 115                if (time_after(ttd, fl->expires))
 116                        fl->expires = ttd;
 117                ttd = fl->expires;
 118                if (fl->opt && fl->share == IPV6_FL_S_EXCL) {
 119                        struct ipv6_txoptions *opt = fl->opt;
 120                        fl->opt = NULL;
 121                        kfree(opt);
 122                }
 123                if (!timer_pending(&ip6_fl_gc_timer) ||
 124                    time_after(ip6_fl_gc_timer.expires, ttd))
 125                        mod_timer(&ip6_fl_gc_timer, ttd);
 126        }
 127        spin_unlock_bh(&ip6_fl_lock);
 128}
 129
 130static void ip6_fl_gc(unsigned long dummy)
 131{
 132        int i;
 133        unsigned long now = jiffies;
 134        unsigned long sched = 0;
 135
 136        spin_lock(&ip6_fl_lock);
 137
 138        for (i = 0; i <= FL_HASH_MASK; i++) {
 139                struct ip6_flowlabel *fl;
 140                struct ip6_flowlabel __rcu **flp;
 141
 142                flp = &fl_ht[i];
 143                while ((fl = rcu_dereference_protected(*flp,
 144                                                       lockdep_is_held(&ip6_fl_lock))) != NULL) {
 145                        if (atomic_read(&fl->users) == 0) {
 146                                unsigned long ttd = fl->lastuse + fl->linger;
 147                                if (time_after(ttd, fl->expires))
 148                                        fl->expires = ttd;
 149                                ttd = fl->expires;
 150                                if (time_after_eq(now, ttd)) {
 151                                        *flp = fl->next;
 152                                        fl_free(fl);
 153                                        atomic_dec(&fl_size);
 154                                        continue;
 155                                }
 156                                if (!sched || time_before(ttd, sched))
 157                                        sched = ttd;
 158                        }
 159                        flp = &fl->next;
 160                }
 161        }
 162        if (!sched && atomic_read(&fl_size))
 163                sched = now + FL_MAX_LINGER;
 164        if (sched) {
 165                mod_timer(&ip6_fl_gc_timer, sched);
 166        }
 167        spin_unlock(&ip6_fl_lock);
 168}
 169
 170static void __net_exit ip6_fl_purge(struct net *net)
 171{
 172        int i;
 173
 174        spin_lock_bh(&ip6_fl_lock);
 175        for (i = 0; i <= FL_HASH_MASK; i++) {
 176                struct ip6_flowlabel *fl;
 177                struct ip6_flowlabel __rcu **flp;
 178
 179                flp = &fl_ht[i];
 180                while ((fl = rcu_dereference_protected(*flp,
 181                                                       lockdep_is_held(&ip6_fl_lock))) != NULL) {
 182                        if (net_eq(fl->fl_net, net) &&
 183                            atomic_read(&fl->users) == 0) {
 184                                *flp = fl->next;
 185                                fl_free(fl);
 186                                atomic_dec(&fl_size);
 187                                continue;
 188                        }
 189                        flp = &fl->next;
 190                }
 191        }
 192        spin_unlock_bh(&ip6_fl_lock);
 193}
 194
 195static struct ip6_flowlabel *fl_intern(struct net *net,
 196                                       struct ip6_flowlabel *fl, __be32 label)
 197{
 198        struct ip6_flowlabel *lfl;
 199
 200        fl->label = label & IPV6_FLOWLABEL_MASK;
 201
 202        spin_lock_bh(&ip6_fl_lock);
 203        if (label == 0) {
 204                for (;;) {
 205                        fl->label = htonl(prandom_u32())&IPV6_FLOWLABEL_MASK;
 206                        if (fl->label) {
 207                                lfl = __fl_lookup(net, fl->label);
 208                                if (!lfl)
 209                                        break;
 210                        }
 211                }
 212        } else {
 213                /*
 214                 * we dropper the ip6_fl_lock, so this entry could reappear
 215                 * and we need to recheck with it.
 216                 *
 217                 * OTOH no need to search the active socket first, like it is
 218                 * done in ipv6_flowlabel_opt - sock is locked, so new entry
 219                 * with the same label can only appear on another sock
 220                 */
 221                lfl = __fl_lookup(net, fl->label);
 222                if (lfl) {
 223                        atomic_inc(&lfl->users);
 224                        spin_unlock_bh(&ip6_fl_lock);
 225                        return lfl;
 226                }
 227        }
 228
 229        fl->lastuse = jiffies;
 230        fl->next = fl_ht[FL_HASH(fl->label)];
 231        rcu_assign_pointer(fl_ht[FL_HASH(fl->label)], fl);
 232        atomic_inc(&fl_size);
 233        spin_unlock_bh(&ip6_fl_lock);
 234        return NULL;
 235}
 236
 237
 238
 239/* Socket flowlabel lists */
 240
 241struct ip6_flowlabel *fl6_sock_lookup(struct sock *sk, __be32 label)
 242{
 243        struct ipv6_fl_socklist *sfl;
 244        struct ipv6_pinfo *np = inet6_sk(sk);
 245
 246        label &= IPV6_FLOWLABEL_MASK;
 247
 248        rcu_read_lock_bh();
 249        for_each_sk_fl_rcu(np, sfl) {
 250                struct ip6_flowlabel *fl = sfl->fl;
 251                if (fl->label == label) {
 252                        fl->lastuse = jiffies;
 253                        atomic_inc(&fl->users);
 254                        rcu_read_unlock_bh();
 255                        return fl;
 256                }
 257        }
 258        rcu_read_unlock_bh();
 259        return NULL;
 260}
 261EXPORT_SYMBOL_GPL(fl6_sock_lookup);
 262
 263void fl6_free_socklist(struct sock *sk)
 264{
 265        struct ipv6_pinfo *np = inet6_sk(sk);
 266        struct ipv6_fl_socklist *sfl;
 267
 268        if (!rcu_access_pointer(np->ipv6_fl_list))
 269                return;
 270
 271        spin_lock_bh(&ip6_sk_fl_lock);
 272        while ((sfl = rcu_dereference_protected(np->ipv6_fl_list,
 273                                                lockdep_is_held(&ip6_sk_fl_lock))) != NULL) {
 274                np->ipv6_fl_list = sfl->next;
 275                spin_unlock_bh(&ip6_sk_fl_lock);
 276
 277                fl_release(sfl->fl);
 278                kfree_rcu(sfl, rcu);
 279
 280                spin_lock_bh(&ip6_sk_fl_lock);
 281        }
 282        spin_unlock_bh(&ip6_sk_fl_lock);
 283}
 284
 285/* Service routines */
 286
 287
 288/*
 289   It is the only difficult place. flowlabel enforces equal headers
 290   before and including routing header, however user may supply options
 291   following rthdr.
 292 */
 293
 294struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions *opt_space,
 295                                         struct ip6_flowlabel *fl,
 296                                         struct ipv6_txoptions *fopt)
 297{
 298        struct ipv6_txoptions *fl_opt = fl->opt;
 299
 300        if (!fopt || fopt->opt_flen == 0)
 301                return fl_opt;
 302
 303        if (fl_opt) {
 304                opt_space->hopopt = fl_opt->hopopt;
 305                opt_space->dst0opt = fl_opt->dst0opt;
 306                opt_space->srcrt = fl_opt->srcrt;
 307                opt_space->opt_nflen = fl_opt->opt_nflen;
 308        } else {
 309                if (fopt->opt_nflen == 0)
 310                        return fopt;
 311                opt_space->hopopt = NULL;
 312                opt_space->dst0opt = NULL;
 313                opt_space->srcrt = NULL;
 314                opt_space->opt_nflen = 0;
 315        }
 316        opt_space->dst1opt = fopt->dst1opt;
 317        opt_space->opt_flen = fopt->opt_flen;
 318        return opt_space;
 319}
 320EXPORT_SYMBOL_GPL(fl6_merge_options);
 321
 322static unsigned long check_linger(unsigned long ttl)
 323{
 324        if (ttl < FL_MIN_LINGER)
 325                return FL_MIN_LINGER*HZ;
 326        if (ttl > FL_MAX_LINGER && !capable(CAP_NET_ADMIN))
 327                return 0;
 328        return ttl*HZ;
 329}
 330
 331static int fl6_renew(struct ip6_flowlabel *fl, unsigned long linger, unsigned long expires)
 332{
 333        linger = check_linger(linger);
 334        if (!linger)
 335                return -EPERM;
 336        expires = check_linger(expires);
 337        if (!expires)
 338                return -EPERM;
 339
 340        spin_lock_bh(&ip6_fl_lock);
 341        fl->lastuse = jiffies;
 342        if (time_before(fl->linger, linger))
 343                fl->linger = linger;
 344        if (time_before(expires, fl->linger))
 345                expires = fl->linger;
 346        if (time_before(fl->expires, fl->lastuse + expires))
 347                fl->expires = fl->lastuse + expires;
 348        spin_unlock_bh(&ip6_fl_lock);
 349
 350        return 0;
 351}
 352
 353static struct ip6_flowlabel *
 354fl_create(struct net *net, struct sock *sk, struct in6_flowlabel_req *freq,
 355          char __user *optval, int optlen, int *err_p)
 356{
 357        struct ip6_flowlabel *fl = NULL;
 358        int olen;
 359        int addr_type;
 360        int err;
 361
 362        olen = optlen - CMSG_ALIGN(sizeof(*freq));
 363        err = -EINVAL;
 364        if (olen > 64 * 1024)
 365                goto done;
 366
 367        err = -ENOMEM;
 368        fl = kzalloc(sizeof(*fl), GFP_KERNEL);
 369        if (!fl)
 370                goto done;
 371
 372        if (olen > 0) {
 373                struct msghdr msg;
 374                struct flowi6 flowi6;
 375                struct sockcm_cookie sockc_junk;
 376                struct ipcm6_cookie ipc6;
 377
 378                err = -ENOMEM;
 379                fl->opt = kmalloc(sizeof(*fl->opt) + olen, GFP_KERNEL);
 380                if (!fl->opt)
 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                ipc6.opt = fl->opt;
 394                err = ip6_datagram_send_ctl(net, sk, &msg, &flowi6, &ipc6, &sockc_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 = 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_protected(*sflp,
 545                                                      lockdep_is_held(&ip6_sk_fl_lock))) != NULL;
 546                     sflp = &sfl->next) {
 547                        if (sfl->fl->label == freq.flr_label) {
 548                                if (freq.flr_label == (np->flow_label&IPV6_FLOWLABEL_MASK))
 549                                        np->flow_label &= ~IPV6_FLOWLABEL_MASK;
 550                                *sflp = sfl->next;
 551                                spin_unlock_bh(&ip6_sk_fl_lock);
 552                                fl_release(sfl->fl);
 553                                kfree_rcu(sfl, rcu);
 554                                return 0;
 555                        }
 556                }
 557                spin_unlock_bh(&ip6_sk_fl_lock);
 558                return -ESRCH;
 559
 560        case IPV6_FL_A_RENEW:
 561                rcu_read_lock_bh();
 562                for_each_sk_fl_rcu(np, sfl) {
 563                        if (sfl->fl->label == freq.flr_label) {
 564                                err = fl6_renew(sfl->fl, freq.flr_linger, freq.flr_expires);
 565                                rcu_read_unlock_bh();
 566                                return err;
 567                        }
 568                }
 569                rcu_read_unlock_bh();
 570
 571                if (freq.flr_share == IPV6_FL_S_NONE &&
 572                    ns_capable(net->user_ns, CAP_NET_ADMIN)) {
 573                        fl = fl_lookup(net, freq.flr_label);
 574                        if (fl) {
 575                                err = fl6_renew(fl, freq.flr_linger, freq.flr_expires);
 576                                fl_release(fl);
 577                                return err;
 578                        }
 579                }
 580                return -ESRCH;
 581
 582        case IPV6_FL_A_GET:
 583                if (freq.flr_flags & IPV6_FL_F_REFLECT) {
 584                        struct net *net = sock_net(sk);
 585                        if (net->ipv6.sysctl.flowlabel_consistency) {
 586                                net_info_ratelimited("Can not set IPV6_FL_F_REFLECT if flowlabel_consistency sysctl is enable\n");
 587                                return -EPERM;
 588                        }
 589
 590                        if (sk->sk_protocol != IPPROTO_TCP)
 591                                return -ENOPROTOOPT;
 592
 593                        np->repflow = 1;
 594                        return 0;
 595                }
 596
 597                if (freq.flr_label & ~IPV6_FLOWLABEL_MASK)
 598                        return -EINVAL;
 599
 600                if (net->ipv6.sysctl.flowlabel_state_ranges &&
 601                    (freq.flr_label & IPV6_FLOWLABEL_STATELESS_FLAG))
 602                        return -ERANGE;
 603
 604                fl = fl_create(net, sk, &freq, optval, optlen, &err);
 605                if (!fl)
 606                        return err;
 607                sfl1 = kmalloc(sizeof(*sfl1), GFP_KERNEL);
 608
 609                if (freq.flr_label) {
 610                        err = -EEXIST;
 611                        rcu_read_lock_bh();
 612                        for_each_sk_fl_rcu(np, sfl) {
 613                                if (sfl->fl->label == freq.flr_label) {
 614                                        if (freq.flr_flags&IPV6_FL_F_EXCL) {
 615                                                rcu_read_unlock_bh();
 616                                                goto done;
 617                                        }
 618                                        fl1 = sfl->fl;
 619                                        atomic_inc(&fl1->users);
 620                                        break;
 621                                }
 622                        }
 623                        rcu_read_unlock_bh();
 624
 625                        if (!fl1)
 626                                fl1 = fl_lookup(net, freq.flr_label);
 627                        if (fl1) {
 628recheck:
 629                                err = -EEXIST;
 630                                if (freq.flr_flags&IPV6_FL_F_EXCL)
 631                                        goto release;
 632                                err = -EPERM;
 633                                if (fl1->share == IPV6_FL_S_EXCL ||
 634                                    fl1->share != fl->share ||
 635                                    ((fl1->share == IPV6_FL_S_PROCESS) &&
 636                                     (fl1->owner.pid == fl->owner.pid)) ||
 637                                    ((fl1->share == IPV6_FL_S_USER) &&
 638                                     uid_eq(fl1->owner.uid, fl->owner.uid)))
 639                                        goto release;
 640
 641                                err = -ENOMEM;
 642                                if (!sfl1)
 643                                        goto release;
 644                                if (fl->linger > fl1->linger)
 645                                        fl1->linger = fl->linger;
 646                                if ((long)(fl->expires - fl1->expires) > 0)
 647                                        fl1->expires = fl->expires;
 648                                fl_link(np, sfl1, fl1);
 649                                fl_free(fl);
 650                                return 0;
 651
 652release:
 653                                fl_release(fl1);
 654                                goto done;
 655                        }
 656                }
 657                err = -ENOENT;
 658                if (!(freq.flr_flags&IPV6_FL_F_CREATE))
 659                        goto done;
 660
 661                err = -ENOMEM;
 662                if (!sfl1)
 663                        goto done;
 664
 665                err = mem_check(sk);
 666                if (err != 0)
 667                        goto done;
 668
 669                fl1 = fl_intern(net, fl, freq.flr_label);
 670                if (fl1)
 671                        goto recheck;
 672
 673                if (!freq.flr_label) {
 674                        if (copy_to_user(&((struct in6_flowlabel_req __user *) optval)->flr_label,
 675                                         &fl->label, sizeof(fl->label))) {
 676                                /* Intentionally ignore fault. */
 677                        }
 678                }
 679
 680                fl_link(np, sfl1, fl);
 681                return 0;
 682
 683        default:
 684                return -EINVAL;
 685        }
 686
 687done:
 688        fl_free(fl);
 689        kfree(sfl1);
 690        return err;
 691}
 692
 693#ifdef CONFIG_PROC_FS
 694
 695struct ip6fl_iter_state {
 696        struct seq_net_private p;
 697        struct pid_namespace *pid_ns;
 698        int bucket;
 699};
 700
 701#define ip6fl_seq_private(seq)  ((struct ip6fl_iter_state *)(seq)->private)
 702
 703static struct ip6_flowlabel *ip6fl_get_first(struct seq_file *seq)
 704{
 705        struct ip6_flowlabel *fl = NULL;
 706        struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 707        struct net *net = seq_file_net(seq);
 708
 709        for (state->bucket = 0; state->bucket <= FL_HASH_MASK; ++state->bucket) {
 710                for_each_fl_rcu(state->bucket, fl) {
 711                        if (net_eq(fl->fl_net, net))
 712                                goto out;
 713                }
 714        }
 715        fl = NULL;
 716out:
 717        return fl;
 718}
 719
 720static struct ip6_flowlabel *ip6fl_get_next(struct seq_file *seq, struct ip6_flowlabel *fl)
 721{
 722        struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 723        struct net *net = seq_file_net(seq);
 724
 725        for_each_fl_continue_rcu(fl) {
 726                if (net_eq(fl->fl_net, net))
 727                        goto out;
 728        }
 729
 730try_again:
 731        if (++state->bucket <= FL_HASH_MASK) {
 732                for_each_fl_rcu(state->bucket, fl) {
 733                        if (net_eq(fl->fl_net, net))
 734                                goto out;
 735                }
 736                goto try_again;
 737        }
 738        fl = NULL;
 739
 740out:
 741        return fl;
 742}
 743
 744static struct ip6_flowlabel *ip6fl_get_idx(struct seq_file *seq, loff_t pos)
 745{
 746        struct ip6_flowlabel *fl = ip6fl_get_first(seq);
 747        if (fl)
 748                while (pos && (fl = ip6fl_get_next(seq, fl)) != NULL)
 749                        --pos;
 750        return pos ? NULL : fl;
 751}
 752
 753static void *ip6fl_seq_start(struct seq_file *seq, loff_t *pos)
 754        __acquires(RCU)
 755{
 756        rcu_read_lock_bh();
 757        return *pos ? ip6fl_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
 758}
 759
 760static void *ip6fl_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 761{
 762        struct ip6_flowlabel *fl;
 763
 764        if (v == SEQ_START_TOKEN)
 765                fl = ip6fl_get_first(seq);
 766        else
 767                fl = ip6fl_get_next(seq, v);
 768        ++*pos;
 769        return fl;
 770}
 771
 772static void ip6fl_seq_stop(struct seq_file *seq, void *v)
 773        __releases(RCU)
 774{
 775        rcu_read_unlock_bh();
 776}
 777
 778static int ip6fl_seq_show(struct seq_file *seq, void *v)
 779{
 780        struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 781        if (v == SEQ_START_TOKEN) {
 782                seq_puts(seq, "Label S Owner  Users  Linger Expires  Dst                              Opt\n");
 783        } else {
 784                struct ip6_flowlabel *fl = v;
 785                seq_printf(seq,
 786                           "%05X %-1d %-6d %-6d %-6ld %-8ld %pi6 %-4d\n",
 787                           (unsigned int)ntohl(fl->label),
 788                           fl->share,
 789                           ((fl->share == IPV6_FL_S_PROCESS) ?
 790                            pid_nr_ns(fl->owner.pid, state->pid_ns) :
 791                            ((fl->share == IPV6_FL_S_USER) ?
 792                             from_kuid_munged(seq_user_ns(seq), fl->owner.uid) :
 793                             0)),
 794                           atomic_read(&fl->users),
 795                           fl->linger/HZ,
 796                           (long)(fl->expires - jiffies)/HZ,
 797                           &fl->dst,
 798                           fl->opt ? fl->opt->opt_nflen : 0);
 799        }
 800        return 0;
 801}
 802
 803static const struct seq_operations ip6fl_seq_ops = {
 804        .start  =       ip6fl_seq_start,
 805        .next   =       ip6fl_seq_next,
 806        .stop   =       ip6fl_seq_stop,
 807        .show   =       ip6fl_seq_show,
 808};
 809
 810static int ip6fl_seq_open(struct inode *inode, struct file *file)
 811{
 812        struct seq_file *seq;
 813        struct ip6fl_iter_state *state;
 814        int err;
 815
 816        err = seq_open_net(inode, file, &ip6fl_seq_ops,
 817                           sizeof(struct ip6fl_iter_state));
 818
 819        if (!err) {
 820                seq = file->private_data;
 821                state = ip6fl_seq_private(seq);
 822                rcu_read_lock();
 823                state->pid_ns = get_pid_ns(task_active_pid_ns(current));
 824                rcu_read_unlock();
 825        }
 826        return err;
 827}
 828
 829static int ip6fl_seq_release(struct inode *inode, struct file *file)
 830{
 831        struct seq_file *seq = file->private_data;
 832        struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 833        put_pid_ns(state->pid_ns);
 834        return seq_release_net(inode, file);
 835}
 836
 837static const struct file_operations ip6fl_seq_fops = {
 838        .owner          =       THIS_MODULE,
 839        .open           =       ip6fl_seq_open,
 840        .read           =       seq_read,
 841        .llseek         =       seq_lseek,
 842        .release        =       ip6fl_seq_release,
 843};
 844
 845static int __net_init ip6_flowlabel_proc_init(struct net *net)
 846{
 847        if (!proc_create("ip6_flowlabel", S_IRUGO, net->proc_net,
 848                         &ip6fl_seq_fops))
 849                return -ENOMEM;
 850        return 0;
 851}
 852
 853static void __net_exit ip6_flowlabel_proc_fini(struct net *net)
 854{
 855        remove_proc_entry("ip6_flowlabel", net->proc_net);
 856}
 857#else
 858static inline int ip6_flowlabel_proc_init(struct net *net)
 859{
 860        return 0;
 861}
 862static inline void ip6_flowlabel_proc_fini(struct net *net)
 863{
 864}
 865#endif
 866
 867static void __net_exit ip6_flowlabel_net_exit(struct net *net)
 868{
 869        ip6_fl_purge(net);
 870        ip6_flowlabel_proc_fini(net);
 871}
 872
 873static struct pernet_operations ip6_flowlabel_net_ops = {
 874        .init = ip6_flowlabel_proc_init,
 875        .exit = ip6_flowlabel_net_exit,
 876};
 877
 878int ip6_flowlabel_init(void)
 879{
 880        return register_pernet_subsys(&ip6_flowlabel_net_ops);
 881}
 882
 883void ip6_flowlabel_cleanup(void)
 884{
 885        del_timer(&ip6_fl_gc_timer);
 886        unregister_pernet_subsys(&ip6_flowlabel_net_ops);
 887}
 888