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 __rcu *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_SPINLOCK(ip6_fl_lock);
  62
  63/* Big socket sock */
  64
  65static DEFINE_SPINLOCK(ip6_sk_fl_lock);
  66
  67#define for_each_fl_rcu(hash, fl)                               \
  68        for (fl = rcu_dereference_bh(fl_ht[(hash)]);            \
  69             fl != NULL;                                        \
  70             fl = rcu_dereference_bh(fl->next))
  71#define for_each_fl_continue_rcu(fl)                            \
  72        for (fl = rcu_dereference_bh(fl->next);                 \
  73             fl != NULL;                                        \
  74             fl = rcu_dereference_bh(fl->next))
  75
  76#define for_each_sk_fl_rcu(np, sfl)                             \
  77        for (sfl = rcu_dereference_bh(np->ipv6_fl_list);        \
  78             sfl != NULL;                                       \
  79             sfl = rcu_dereference_bh(sfl->next))
  80
  81static inline struct ip6_flowlabel *__fl_lookup(struct net *net, __be32 label)
  82{
  83        struct ip6_flowlabel *fl;
  84
  85        for_each_fl_rcu(FL_HASH(label), fl) {
  86                if (fl->label == label && net_eq(fl->fl_net, net))
  87                        return fl;
  88        }
  89        return NULL;
  90}
  91
  92static struct ip6_flowlabel *fl_lookup(struct net *net, __be32 label)
  93{
  94        struct ip6_flowlabel *fl;
  95
  96        rcu_read_lock_bh();
  97        fl = __fl_lookup(net, label);
  98        if (fl && !atomic_inc_not_zero(&fl->users))
  99                fl = NULL;
 100        rcu_read_unlock_bh();
 101        return fl;
 102}
 103
 104
 105static void fl_free(struct ip6_flowlabel *fl)
 106{
 107        if (fl) {
 108                if (fl->share == IPV6_FL_S_PROCESS)
 109                        put_pid(fl->owner.pid);
 110                release_net(fl->fl_net);
 111                kfree(fl->opt);
 112                kfree_rcu(fl, rcu);
 113        }
 114}
 115
 116static void fl_release(struct ip6_flowlabel *fl)
 117{
 118        spin_lock_bh(&ip6_fl_lock);
 119
 120        fl->lastuse = jiffies;
 121        if (atomic_dec_and_test(&fl->users)) {
 122                unsigned long ttd = fl->lastuse + fl->linger;
 123                if (time_after(ttd, fl->expires))
 124                        fl->expires = ttd;
 125                ttd = fl->expires;
 126                if (fl->opt && fl->share == IPV6_FL_S_EXCL) {
 127                        struct ipv6_txoptions *opt = fl->opt;
 128                        fl->opt = NULL;
 129                        kfree(opt);
 130                }
 131                if (!timer_pending(&ip6_fl_gc_timer) ||
 132                    time_after(ip6_fl_gc_timer.expires, ttd))
 133                        mod_timer(&ip6_fl_gc_timer, ttd);
 134        }
 135        spin_unlock_bh(&ip6_fl_lock);
 136}
 137
 138static void ip6_fl_gc(unsigned long dummy)
 139{
 140        int i;
 141        unsigned long now = jiffies;
 142        unsigned long sched = 0;
 143
 144        spin_lock(&ip6_fl_lock);
 145
 146        for (i=0; i<=FL_HASH_MASK; i++) {
 147                struct ip6_flowlabel *fl;
 148                struct ip6_flowlabel __rcu **flp;
 149
 150                flp = &fl_ht[i];
 151                while ((fl = rcu_dereference_protected(*flp,
 152                                                       lockdep_is_held(&ip6_fl_lock))) != NULL) {
 153                        if (atomic_read(&fl->users) == 0) {
 154                                unsigned long ttd = fl->lastuse + fl->linger;
 155                                if (time_after(ttd, fl->expires))
 156                                        fl->expires = ttd;
 157                                ttd = fl->expires;
 158                                if (time_after_eq(now, ttd)) {
 159                                        *flp = fl->next;
 160                                        fl_free(fl);
 161                                        atomic_dec(&fl_size);
 162                                        continue;
 163                                }
 164                                if (!sched || time_before(ttd, sched))
 165                                        sched = ttd;
 166                        }
 167                        flp = &fl->next;
 168                }
 169        }
 170        if (!sched && atomic_read(&fl_size))
 171                sched = now + FL_MAX_LINGER;
 172        if (sched) {
 173                mod_timer(&ip6_fl_gc_timer, sched);
 174        }
 175        spin_unlock(&ip6_fl_lock);
 176}
 177
 178static void __net_exit ip6_fl_purge(struct net *net)
 179{
 180        int i;
 181
 182        spin_lock(&ip6_fl_lock);
 183        for (i = 0; i <= FL_HASH_MASK; i++) {
 184                struct ip6_flowlabel *fl;
 185                struct ip6_flowlabel __rcu **flp;
 186
 187                flp = &fl_ht[i];
 188                while ((fl = rcu_dereference_protected(*flp,
 189                                                       lockdep_is_held(&ip6_fl_lock))) != NULL) {
 190                        if (net_eq(fl->fl_net, net) &&
 191                            atomic_read(&fl->users) == 0) {
 192                                *flp = fl->next;
 193                                fl_free(fl);
 194                                atomic_dec(&fl_size);
 195                                continue;
 196                        }
 197                        flp = &fl->next;
 198                }
 199        }
 200        spin_unlock(&ip6_fl_lock);
 201}
 202
 203static struct ip6_flowlabel *fl_intern(struct net *net,
 204                                       struct ip6_flowlabel *fl, __be32 label)
 205{
 206        struct ip6_flowlabel *lfl;
 207
 208        fl->label = label & IPV6_FLOWLABEL_MASK;
 209
 210        spin_lock_bh(&ip6_fl_lock);
 211        if (label == 0) {
 212                for (;;) {
 213                        fl->label = htonl(net_random())&IPV6_FLOWLABEL_MASK;
 214                        if (fl->label) {
 215                                lfl = __fl_lookup(net, fl->label);
 216                                if (lfl == NULL)
 217                                        break;
 218                        }
 219                }
 220        } else {
 221                /*
 222                 * we dropper the ip6_fl_lock, so this entry could reappear
 223                 * and we need to recheck with it.
 224                 *
 225                 * OTOH no need to search the active socket first, like it is
 226                 * done in ipv6_flowlabel_opt - sock is locked, so new entry
 227                 * with the same label can only appear on another sock
 228                 */
 229                lfl = __fl_lookup(net, fl->label);
 230                if (lfl != NULL) {
 231                        atomic_inc(&lfl->users);
 232                        spin_unlock_bh(&ip6_fl_lock);
 233                        return lfl;
 234                }
 235        }
 236
 237        fl->lastuse = jiffies;
 238        fl->next = fl_ht[FL_HASH(fl->label)];
 239        rcu_assign_pointer(fl_ht[FL_HASH(fl->label)], fl);
 240        atomic_inc(&fl_size);
 241        spin_unlock_bh(&ip6_fl_lock);
 242        return NULL;
 243}
 244
 245
 246
 247/* Socket flowlabel lists */
 248
 249struct ip6_flowlabel * fl6_sock_lookup(struct sock *sk, __be32 label)
 250{
 251        struct ipv6_fl_socklist *sfl;
 252        struct ipv6_pinfo *np = inet6_sk(sk);
 253
 254        label &= IPV6_FLOWLABEL_MASK;
 255
 256        rcu_read_lock_bh();
 257        for_each_sk_fl_rcu(np, sfl) {
 258                struct ip6_flowlabel *fl = sfl->fl;
 259                if (fl->label == label) {
 260                        fl->lastuse = jiffies;
 261                        atomic_inc(&fl->users);
 262                        rcu_read_unlock_bh();
 263                        return fl;
 264                }
 265        }
 266        rcu_read_unlock_bh();
 267        return NULL;
 268}
 269
 270EXPORT_SYMBOL_GPL(fl6_sock_lookup);
 271
 272void fl6_free_socklist(struct sock *sk)
 273{
 274        struct ipv6_pinfo *np = inet6_sk(sk);
 275        struct ipv6_fl_socklist *sfl;
 276
 277        if (!rcu_access_pointer(np->ipv6_fl_list))
 278                return;
 279
 280        spin_lock_bh(&ip6_sk_fl_lock);
 281        while ((sfl = rcu_dereference_protected(np->ipv6_fl_list,
 282                                                lockdep_is_held(&ip6_sk_fl_lock))) != NULL) {
 283                np->ipv6_fl_list = sfl->next;
 284                spin_unlock_bh(&ip6_sk_fl_lock);
 285
 286                fl_release(sfl->fl);
 287                kfree_rcu(sfl, rcu);
 288
 289                spin_lock_bh(&ip6_sk_fl_lock);
 290        }
 291        spin_unlock_bh(&ip6_sk_fl_lock);
 292}
 293
 294/* Service routines */
 295
 296
 297/*
 298   It is the only difficult place. flowlabel enforces equal headers
 299   before and including routing header, however user may supply options
 300   following rthdr.
 301 */
 302
 303struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions * opt_space,
 304                                         struct ip6_flowlabel * fl,
 305                                         struct ipv6_txoptions * fopt)
 306{
 307        struct ipv6_txoptions * fl_opt = fl->opt;
 308
 309        if (fopt == NULL || fopt->opt_flen == 0)
 310                return fl_opt;
 311
 312        if (fl_opt != NULL) {
 313                opt_space->hopopt = fl_opt->hopopt;
 314                opt_space->dst0opt = fl_opt->dst0opt;
 315                opt_space->srcrt = fl_opt->srcrt;
 316                opt_space->opt_nflen = fl_opt->opt_nflen;
 317        } else {
 318                if (fopt->opt_nflen == 0)
 319                        return fopt;
 320                opt_space->hopopt = NULL;
 321                opt_space->dst0opt = NULL;
 322                opt_space->srcrt = NULL;
 323                opt_space->opt_nflen = 0;
 324        }
 325        opt_space->dst1opt = fopt->dst1opt;
 326        opt_space->opt_flen = fopt->opt_flen;
 327        return opt_space;
 328}
 329EXPORT_SYMBOL_GPL(fl6_merge_options);
 330
 331static unsigned long check_linger(unsigned long ttl)
 332{
 333        if (ttl < FL_MIN_LINGER)
 334                return FL_MIN_LINGER*HZ;
 335        if (ttl > FL_MAX_LINGER && !capable(CAP_NET_ADMIN))
 336                return 0;
 337        return ttl*HZ;
 338}
 339
 340static int fl6_renew(struct ip6_flowlabel *fl, unsigned long linger, unsigned long expires)
 341{
 342        linger = check_linger(linger);
 343        if (!linger)
 344                return -EPERM;
 345        expires = check_linger(expires);
 346        if (!expires)
 347                return -EPERM;
 348        fl->lastuse = jiffies;
 349        if (time_before(fl->linger, linger))
 350                fl->linger = linger;
 351        if (time_before(expires, fl->linger))
 352                expires = fl->linger;
 353        if (time_before(fl->expires, fl->lastuse + expires))
 354                fl->expires = fl->lastuse + expires;
 355        return 0;
 356}
 357
 358static struct ip6_flowlabel *
 359fl_create(struct net *net, struct sock *sk, struct in6_flowlabel_req *freq,
 360          char __user *optval, int optlen, int *err_p)
 361{
 362        struct ip6_flowlabel *fl = NULL;
 363        int olen;
 364        int addr_type;
 365        int err;
 366
 367        olen = optlen - CMSG_ALIGN(sizeof(*freq));
 368        err = -EINVAL;
 369        if (olen > 64 * 1024)
 370                goto done;
 371
 372        err = -ENOMEM;
 373        fl = kzalloc(sizeof(*fl), GFP_KERNEL);
 374        if (fl == NULL)
 375                goto done;
 376
 377        if (olen > 0) {
 378                struct msghdr msg;
 379                struct flowi6 flowi6;
 380                int junk;
 381
 382                err = -ENOMEM;
 383                fl->opt = kmalloc(sizeof(*fl->opt) + olen, GFP_KERNEL);
 384                if (fl->opt == NULL)
 385                        goto done;
 386
 387                memset(fl->opt, 0, sizeof(*fl->opt));
 388                fl->opt->tot_len = sizeof(*fl->opt) + olen;
 389                err = -EFAULT;
 390                if (copy_from_user(fl->opt+1, optval+CMSG_ALIGN(sizeof(*freq)), olen))
 391                        goto done;
 392
 393                msg.msg_controllen = olen;
 394                msg.msg_control = (void*)(fl->opt+1);
 395                memset(&flowi6, 0, sizeof(flowi6));
 396
 397                err = ip6_datagram_send_ctl(net, sk, &msg, &flowi6, fl->opt,
 398                                            &junk, &junk, &junk);
 399                if (err)
 400                        goto done;
 401                err = -EINVAL;
 402                if (fl->opt->opt_flen)
 403                        goto done;
 404                if (fl->opt->opt_nflen == 0) {
 405                        kfree(fl->opt);
 406                        fl->opt = NULL;
 407                }
 408        }
 409
 410        fl->fl_net = hold_net(net);
 411        fl->expires = jiffies;
 412        err = fl6_renew(fl, freq->flr_linger, freq->flr_expires);
 413        if (err)
 414                goto done;
 415        fl->share = freq->flr_share;
 416        addr_type = ipv6_addr_type(&freq->flr_dst);
 417        if ((addr_type & IPV6_ADDR_MAPPED) ||
 418            addr_type == IPV6_ADDR_ANY) {
 419                err = -EINVAL;
 420                goto done;
 421        }
 422        fl->dst = freq->flr_dst;
 423        atomic_set(&fl->users, 1);
 424        switch (fl->share) {
 425        case IPV6_FL_S_EXCL:
 426        case IPV6_FL_S_ANY:
 427                break;
 428        case IPV6_FL_S_PROCESS:
 429                fl->owner.pid = get_task_pid(current, PIDTYPE_PID);
 430                break;
 431        case IPV6_FL_S_USER:
 432                fl->owner.uid = current_euid();
 433                break;
 434        default:
 435                err = -EINVAL;
 436                goto done;
 437        }
 438        return fl;
 439
 440done:
 441        fl_free(fl);
 442        *err_p = err;
 443        return NULL;
 444}
 445
 446static int mem_check(struct sock *sk)
 447{
 448        struct ipv6_pinfo *np = inet6_sk(sk);
 449        struct ipv6_fl_socklist *sfl;
 450        int room = FL_MAX_SIZE - atomic_read(&fl_size);
 451        int count = 0;
 452
 453        if (room > FL_MAX_SIZE - FL_MAX_PER_SOCK)
 454                return 0;
 455
 456        for_each_sk_fl_rcu(np, sfl)
 457                count++;
 458
 459        if (room <= 0 ||
 460            ((count >= FL_MAX_PER_SOCK ||
 461              (count > 0 && room < FL_MAX_SIZE/2) || room < FL_MAX_SIZE/4) &&
 462             !capable(CAP_NET_ADMIN)))
 463                return -ENOBUFS;
 464
 465        return 0;
 466}
 467
 468static bool ipv6_hdr_cmp(struct ipv6_opt_hdr *h1, struct ipv6_opt_hdr *h2)
 469{
 470        if (h1 == h2)
 471                return false;
 472        if (h1 == NULL || h2 == NULL)
 473                return true;
 474        if (h1->hdrlen != h2->hdrlen)
 475                return true;
 476        return memcmp(h1+1, h2+1, ((h1->hdrlen+1)<<3) - sizeof(*h1));
 477}
 478
 479static bool ipv6_opt_cmp(struct ipv6_txoptions *o1, struct ipv6_txoptions *o2)
 480{
 481        if (o1 == o2)
 482                return false;
 483        if (o1 == NULL || o2 == NULL)
 484                return true;
 485        if (o1->opt_nflen != o2->opt_nflen)
 486                return true;
 487        if (ipv6_hdr_cmp(o1->hopopt, o2->hopopt))
 488                return true;
 489        if (ipv6_hdr_cmp(o1->dst0opt, o2->dst0opt))
 490                return true;
 491        if (ipv6_hdr_cmp((struct ipv6_opt_hdr *)o1->srcrt, (struct ipv6_opt_hdr *)o2->srcrt))
 492                return true;
 493        return false;
 494}
 495
 496static inline void fl_link(struct ipv6_pinfo *np, struct ipv6_fl_socklist *sfl,
 497                struct ip6_flowlabel *fl)
 498{
 499        spin_lock_bh(&ip6_sk_fl_lock);
 500        sfl->fl = fl;
 501        sfl->next = np->ipv6_fl_list;
 502        rcu_assign_pointer(np->ipv6_fl_list, sfl);
 503        spin_unlock_bh(&ip6_sk_fl_lock);
 504}
 505
 506int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen)
 507{
 508        int uninitialized_var(err);
 509        struct net *net = sock_net(sk);
 510        struct ipv6_pinfo *np = inet6_sk(sk);
 511        struct in6_flowlabel_req freq;
 512        struct ipv6_fl_socklist *sfl1=NULL;
 513        struct ipv6_fl_socklist *sfl;
 514        struct ipv6_fl_socklist __rcu **sflp;
 515        struct ip6_flowlabel *fl, *fl1 = NULL;
 516
 517
 518        if (optlen < sizeof(freq))
 519                return -EINVAL;
 520
 521        if (copy_from_user(&freq, optval, sizeof(freq)))
 522                return -EFAULT;
 523
 524        switch (freq.flr_action) {
 525        case IPV6_FL_A_PUT:
 526                spin_lock_bh(&ip6_sk_fl_lock);
 527                for (sflp = &np->ipv6_fl_list;
 528                     (sfl = rcu_dereference(*sflp))!=NULL;
 529                     sflp = &sfl->next) {
 530                        if (sfl->fl->label == freq.flr_label) {
 531                                if (freq.flr_label == (np->flow_label&IPV6_FLOWLABEL_MASK))
 532                                        np->flow_label &= ~IPV6_FLOWLABEL_MASK;
 533                                *sflp = rcu_dereference(sfl->next);
 534                                spin_unlock_bh(&ip6_sk_fl_lock);
 535                                fl_release(sfl->fl);
 536                                kfree_rcu(sfl, rcu);
 537                                return 0;
 538                        }
 539                }
 540                spin_unlock_bh(&ip6_sk_fl_lock);
 541                return -ESRCH;
 542
 543        case IPV6_FL_A_RENEW:
 544                rcu_read_lock_bh();
 545                for_each_sk_fl_rcu(np, sfl) {
 546                        if (sfl->fl->label == freq.flr_label) {
 547                                err = fl6_renew(sfl->fl, freq.flr_linger, freq.flr_expires);
 548                                rcu_read_unlock_bh();
 549                                return err;
 550                        }
 551                }
 552                rcu_read_unlock_bh();
 553
 554                if (freq.flr_share == IPV6_FL_S_NONE &&
 555                    ns_capable(net->user_ns, CAP_NET_ADMIN)) {
 556                        fl = fl_lookup(net, freq.flr_label);
 557                        if (fl) {
 558                                err = fl6_renew(fl, freq.flr_linger, freq.flr_expires);
 559                                fl_release(fl);
 560                                return err;
 561                        }
 562                }
 563                return -ESRCH;
 564
 565        case IPV6_FL_A_GET:
 566                if (freq.flr_label & ~IPV6_FLOWLABEL_MASK)
 567                        return -EINVAL;
 568
 569                fl = fl_create(net, sk, &freq, optval, optlen, &err);
 570                if (fl == NULL)
 571                        return err;
 572                sfl1 = kmalloc(sizeof(*sfl1), GFP_KERNEL);
 573
 574                if (freq.flr_label) {
 575                        err = -EEXIST;
 576                        rcu_read_lock_bh();
 577                        for_each_sk_fl_rcu(np, sfl) {
 578                                if (sfl->fl->label == freq.flr_label) {
 579                                        if (freq.flr_flags&IPV6_FL_F_EXCL) {
 580                                                rcu_read_unlock_bh();
 581                                                goto done;
 582                                        }
 583                                        fl1 = sfl->fl;
 584                                        atomic_inc(&fl1->users);
 585                                        break;
 586                                }
 587                        }
 588                        rcu_read_unlock_bh();
 589
 590                        if (fl1 == NULL)
 591                                fl1 = fl_lookup(net, freq.flr_label);
 592                        if (fl1) {
 593recheck:
 594                                err = -EEXIST;
 595                                if (freq.flr_flags&IPV6_FL_F_EXCL)
 596                                        goto release;
 597                                err = -EPERM;
 598                                if (fl1->share == IPV6_FL_S_EXCL ||
 599                                    fl1->share != fl->share ||
 600                                    ((fl1->share == IPV6_FL_S_PROCESS) &&
 601                                     (fl1->owner.pid == fl->owner.pid)) ||
 602                                    ((fl1->share == IPV6_FL_S_USER) &&
 603                                     uid_eq(fl1->owner.uid, fl->owner.uid)))
 604                                        goto release;
 605
 606                                err = -EINVAL;
 607                                if (!ipv6_addr_equal(&fl1->dst, &fl->dst) ||
 608                                    ipv6_opt_cmp(fl1->opt, fl->opt))
 609                                        goto release;
 610
 611                                err = -ENOMEM;
 612                                if (sfl1 == NULL)
 613                                        goto release;
 614                                if (fl->linger > fl1->linger)
 615                                        fl1->linger = fl->linger;
 616                                if ((long)(fl->expires - fl1->expires) > 0)
 617                                        fl1->expires = fl->expires;
 618                                fl_link(np, sfl1, fl1);
 619                                fl_free(fl);
 620                                return 0;
 621
 622release:
 623                                fl_release(fl1);
 624                                goto done;
 625                        }
 626                }
 627                err = -ENOENT;
 628                if (!(freq.flr_flags&IPV6_FL_F_CREATE))
 629                        goto done;
 630
 631                err = -ENOMEM;
 632                if (sfl1 == NULL || (err = mem_check(sk)) != 0)
 633                        goto done;
 634
 635                fl1 = fl_intern(net, fl, freq.flr_label);
 636                if (fl1 != NULL)
 637                        goto recheck;
 638
 639                if (!freq.flr_label) {
 640                        if (copy_to_user(&((struct in6_flowlabel_req __user *) optval)->flr_label,
 641                                         &fl->label, sizeof(fl->label))) {
 642                                /* Intentionally ignore fault. */
 643                        }
 644                }
 645
 646                fl_link(np, sfl1, fl);
 647                return 0;
 648
 649        default:
 650                return -EINVAL;
 651        }
 652
 653done:
 654        fl_free(fl);
 655        kfree(sfl1);
 656        return err;
 657}
 658
 659#ifdef CONFIG_PROC_FS
 660
 661struct ip6fl_iter_state {
 662        struct seq_net_private p;
 663        struct pid_namespace *pid_ns;
 664        int bucket;
 665};
 666
 667#define ip6fl_seq_private(seq)  ((struct ip6fl_iter_state *)(seq)->private)
 668
 669static struct ip6_flowlabel *ip6fl_get_first(struct seq_file *seq)
 670{
 671        struct ip6_flowlabel *fl = NULL;
 672        struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 673        struct net *net = seq_file_net(seq);
 674
 675        for (state->bucket = 0; state->bucket <= FL_HASH_MASK; ++state->bucket) {
 676                for_each_fl_rcu(state->bucket, fl) {
 677                        if (net_eq(fl->fl_net, net))
 678                                goto out;
 679                }
 680        }
 681        fl = NULL;
 682out:
 683        return fl;
 684}
 685
 686static struct ip6_flowlabel *ip6fl_get_next(struct seq_file *seq, struct ip6_flowlabel *fl)
 687{
 688        struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 689        struct net *net = seq_file_net(seq);
 690
 691        for_each_fl_continue_rcu(fl) {
 692                if (net_eq(fl->fl_net, net))
 693                        goto out;
 694        }
 695
 696try_again:
 697        if (++state->bucket <= FL_HASH_MASK) {
 698                for_each_fl_rcu(state->bucket, fl) {
 699                        if (net_eq(fl->fl_net, net))
 700                                goto out;
 701                }
 702                goto try_again;
 703        }
 704        fl = NULL;
 705
 706out:
 707        return fl;
 708}
 709
 710static struct ip6_flowlabel *ip6fl_get_idx(struct seq_file *seq, loff_t pos)
 711{
 712        struct ip6_flowlabel *fl = ip6fl_get_first(seq);
 713        if (fl)
 714                while (pos && (fl = ip6fl_get_next(seq, fl)) != NULL)
 715                        --pos;
 716        return pos ? NULL : fl;
 717}
 718
 719static void *ip6fl_seq_start(struct seq_file *seq, loff_t *pos)
 720        __acquires(RCU)
 721{
 722        rcu_read_lock_bh();
 723        return *pos ? ip6fl_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
 724}
 725
 726static void *ip6fl_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 727{
 728        struct ip6_flowlabel *fl;
 729
 730        if (v == SEQ_START_TOKEN)
 731                fl = ip6fl_get_first(seq);
 732        else
 733                fl = ip6fl_get_next(seq, v);
 734        ++*pos;
 735        return fl;
 736}
 737
 738static void ip6fl_seq_stop(struct seq_file *seq, void *v)
 739        __releases(RCU)
 740{
 741        rcu_read_unlock_bh();
 742}
 743
 744static int ip6fl_seq_show(struct seq_file *seq, void *v)
 745{
 746        struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 747        if (v == SEQ_START_TOKEN)
 748                seq_printf(seq, "%-5s %-1s %-6s %-6s %-6s %-8s %-32s %s\n",
 749                           "Label", "S", "Owner", "Users", "Linger", "Expires", "Dst", "Opt");
 750        else {
 751                struct ip6_flowlabel *fl = v;
 752                seq_printf(seq,
 753                           "%05X %-1d %-6d %-6d %-6ld %-8ld %pi6 %-4d\n",
 754                           (unsigned int)ntohl(fl->label),
 755                           fl->share,
 756                           ((fl->share == IPV6_FL_S_PROCESS) ?
 757                            pid_nr_ns(fl->owner.pid, state->pid_ns) :
 758                            ((fl->share == IPV6_FL_S_USER) ?
 759                             from_kuid_munged(seq_user_ns(seq), fl->owner.uid) :
 760                             0)),
 761                           atomic_read(&fl->users),
 762                           fl->linger/HZ,
 763                           (long)(fl->expires - jiffies)/HZ,
 764                           &fl->dst,
 765                           fl->opt ? fl->opt->opt_nflen : 0);
 766        }
 767        return 0;
 768}
 769
 770static const struct seq_operations ip6fl_seq_ops = {
 771        .start  =       ip6fl_seq_start,
 772        .next   =       ip6fl_seq_next,
 773        .stop   =       ip6fl_seq_stop,
 774        .show   =       ip6fl_seq_show,
 775};
 776
 777static int ip6fl_seq_open(struct inode *inode, struct file *file)
 778{
 779        struct seq_file *seq;
 780        struct ip6fl_iter_state *state;
 781        int err;
 782
 783        err = seq_open_net(inode, file, &ip6fl_seq_ops,
 784                           sizeof(struct ip6fl_iter_state));
 785
 786        if (!err) {
 787                seq = file->private_data;
 788                state = ip6fl_seq_private(seq);
 789                rcu_read_lock();
 790                state->pid_ns = get_pid_ns(task_active_pid_ns(current));
 791                rcu_read_unlock();
 792        }
 793        return err;
 794}
 795
 796static int ip6fl_seq_release(struct inode *inode, struct file *file)
 797{
 798        struct seq_file *seq = file->private_data;
 799        struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 800        put_pid_ns(state->pid_ns);
 801        return seq_release_net(inode, file);
 802}
 803
 804static const struct file_operations ip6fl_seq_fops = {
 805        .owner          =       THIS_MODULE,
 806        .open           =       ip6fl_seq_open,
 807        .read           =       seq_read,
 808        .llseek         =       seq_lseek,
 809        .release        =       ip6fl_seq_release,
 810};
 811
 812static int __net_init ip6_flowlabel_proc_init(struct net *net)
 813{
 814        if (!proc_create("ip6_flowlabel", S_IRUGO, net->proc_net,
 815                         &ip6fl_seq_fops))
 816                return -ENOMEM;
 817        return 0;
 818}
 819
 820static void __net_exit ip6_flowlabel_proc_fini(struct net *net)
 821{
 822        remove_proc_entry("ip6_flowlabel", net->proc_net);
 823}
 824#else
 825static inline int ip6_flowlabel_proc_init(struct net *net)
 826{
 827        return 0;
 828}
 829static inline void ip6_flowlabel_proc_fini(struct net *net)
 830{
 831}
 832#endif
 833
 834static void __net_exit ip6_flowlabel_net_exit(struct net *net)
 835{
 836        ip6_fl_purge(net);
 837        ip6_flowlabel_proc_fini(net);
 838}
 839
 840static struct pernet_operations ip6_flowlabel_net_ops = {
 841        .init = ip6_flowlabel_proc_init,
 842        .exit = ip6_flowlabel_net_exit,
 843};
 844
 845int ip6_flowlabel_init(void)
 846{
 847        return register_pernet_subsys(&ip6_flowlabel_net_ops);
 848}
 849
 850void ip6_flowlabel_cleanup(void)
 851{
 852        del_timer(&ip6_fl_gc_timer);
 853        unregister_pernet_subsys(&ip6_flowlabel_net_ops);
 854}
 855