net/ipv6/ip6_flowlabel.c

   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
  46 static atomic_t fl_size = ATOMIC_INIT(0);
  47 static struct ip6_flowlabel __rcu *fl_ht[FL_HASH_MASK+1];
  48
  49 static void ip6_fl_gc(unsigned long dummy);
  50 static DEFINE_TIMER(ip6_fl_gc_timer, ip6_fl_gc, 0, 0);
  51
  52 /* FL hash table lock: it protects only of GC */
  53
  54 static DEFINE_SPINLOCK(ip6_fl_lock);
  55
  56 /* Big socket sock */
  57
  58 static 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
  74 static 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
  85 static 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
  98 static 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
 108 static 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
 130 static 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
 170 static 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
 195 static 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
 241 struct 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 }
 261 EXPORT_SYMBOL_GPL(fl6_sock_lookup);
 262
 263 void 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
 294 struct 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         opt_space->tot_len = fopt->tot_len;
 319         return opt_space;
 320 }
 321 EXPORT_SYMBOL_GPL(fl6_merge_options);
 322
 323 static 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
 332 static 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
 354 static struct ip6_flowlabel *
 355 fl_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)
 371                 goto done;
 372
 373         if (olen > 0) {
 374                 struct msghdr msg;
 375                 struct flowi6 flowi6;
 376                 struct sockcm_cookie sockc_junk;
 377                 struct ipcm6_cookie ipc6;
 378
 379                 err = -ENOMEM;
 380                 fl->opt = kmalloc(sizeof(*fl->opt) + olen, GFP_KERNEL);
 381                 if (!fl->opt)
 382                         goto done;
 383
 384                 memset(fl->opt, 0, sizeof(*fl->opt));
 385                 fl->opt->tot_len = sizeof(*fl->opt) + olen;
 386                 err = -EFAULT;
 387                 if (copy_from_user(fl->opt+1, optval+CMSG_ALIGN(sizeof(*freq)), olen))
 388                         goto done;
 389
 390                 msg.msg_controllen = olen;
 391                 msg.msg_control = (void *)(fl->opt+1);
 392                 memset(&flowi6, 0, sizeof(flowi6));
 393
 394                 ipc6.opt = fl->opt;
 395                 err = ip6_datagram_send_ctl(net, sk, &msg, &flowi6, &ipc6, &sockc_junk);
 396                 if (err)
 397                         goto done;
 398                 err = -EINVAL;
 399                 if (fl->opt->opt_flen)
 400                         goto done;
 401                 if (fl->opt->opt_nflen == 0) {
 402                         kfree(fl->opt);
 403                         fl->opt = NULL;
 404                 }
 405         }
 406
 407         fl->fl_net = net;
 408         fl->expires = jiffies;
 409         err = fl6_renew(fl, freq->flr_linger, freq->flr_expires);
 410         if (err)
 411                 goto done;
 412         fl->share = freq->flr_share;
 413         addr_type = ipv6_addr_type(&freq->flr_dst);
 414         if ((addr_type & IPV6_ADDR_MAPPED) ||
 415             addr_type == IPV6_ADDR_ANY) {
 416                 err = -EINVAL;
 417                 goto done;
 418         }
 419         fl->dst = freq->flr_dst;
 420         atomic_set(&fl->users, 1);
 421         switch (fl->share) {
 422         case IPV6_FL_S_EXCL:
 423         case IPV6_FL_S_ANY:
 424                 break;
 425         case IPV6_FL_S_PROCESS:
 426                 fl->owner.pid = get_task_pid(current, PIDTYPE_PID);
 427                 break;
 428         case IPV6_FL_S_USER:
 429                 fl->owner.uid = current_euid();
 430                 break;
 431         default:
 432                 err = -EINVAL;
 433                 goto done;
 434         }
 435         return fl;
 436
 437 done:
 438         fl_free(fl);
 439         *err_p = err;
 440         return NULL;
 441 }
 442
 443 static int mem_check(struct sock *sk)
 444 {
 445         struct ipv6_pinfo *np = inet6_sk(sk);
 446         struct ipv6_fl_socklist *sfl;
 447         int room = FL_MAX_SIZE - atomic_read(&fl_size);
 448         int count = 0;
 449
 450         if (room > FL_MAX_SIZE - FL_MAX_PER_SOCK)
 451                 return 0;
 452
 453         rcu_read_lock_bh();
 454         for_each_sk_fl_rcu(np, sfl)
 455                 count++;
 456         rcu_read_unlock_bh();
 457
 458         if (room <= 0 ||
 459             ((count >= FL_MAX_PER_SOCK ||
 460               (count > 0 && room < FL_MAX_SIZE/2) || room < FL_MAX_SIZE/4) &&
 461              !capable(CAP_NET_ADMIN)))
 462                 return -ENOBUFS;
 463
 464         return 0;
 465 }
 466
 467 static inline void fl_link(struct ipv6_pinfo *np, struct ipv6_fl_socklist *sfl,
 468                 struct ip6_flowlabel *fl)
 469 {
 470         spin_lock_bh(&ip6_sk_fl_lock);
 471         sfl->fl = fl;
 472         sfl->next = np->ipv6_fl_list;
 473         rcu_assign_pointer(np->ipv6_fl_list, sfl);
 474         spin_unlock_bh(&ip6_sk_fl_lock);
 475 }
 476
 477 int ipv6_flowlabel_opt_get(struct sock *sk, struct in6_flowlabel_req *freq,
 478                            int flags)
 479 {
 480         struct ipv6_pinfo *np = inet6_sk(sk);
 481         struct ipv6_fl_socklist *sfl;
 482
 483         if (flags & IPV6_FL_F_REMOTE) {
 484                 freq->flr_label = np->rcv_flowinfo & IPV6_FLOWLABEL_MASK;
 485                 return 0;
 486         }
 487
 488         if (np->repflow) {
 489                 freq->flr_label = np->flow_label;
 490                 return 0;
 491         }
 492
 493         rcu_read_lock_bh();
 494
 495         for_each_sk_fl_rcu(np, sfl) {
 496                 if (sfl->fl->label == (np->flow_label & IPV6_FLOWLABEL_MASK)) {
 497                         spin_lock_bh(&ip6_fl_lock);
 498                         freq->flr_label = sfl->fl->label;
 499                         freq->flr_dst = sfl->fl->dst;
 500                         freq->flr_share = sfl->fl->share;
 501                         freq->flr_expires = (sfl->fl->expires - jiffies) / HZ;
 502                         freq->flr_linger = sfl->fl->linger / HZ;
 503
 504                         spin_unlock_bh(&ip6_fl_lock);
 505                         rcu_read_unlock_bh();
 506                         return 0;
 507                 }
 508         }
 509         rcu_read_unlock_bh();
 510
 511         return -ENOENT;
 512 }
 513
 514 int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen)
 515 {
 516         int uninitialized_var(err);
 517         struct net *net = sock_net(sk);
 518         struct ipv6_pinfo *np = inet6_sk(sk);
 519         struct in6_flowlabel_req freq;
 520         struct ipv6_fl_socklist *sfl1 = NULL;
 521         struct ipv6_fl_socklist *sfl;
 522         struct ipv6_fl_socklist __rcu **sflp;
 523         struct ip6_flowlabel *fl, *fl1 = NULL;
 524
 525
 526         if (optlen < sizeof(freq))
 527                 return -EINVAL;
 528
 529         if (copy_from_user(&freq, optval, sizeof(freq)))
 530                 return -EFAULT;
 531
 532         switch (freq.flr_action) {
 533         case IPV6_FL_A_PUT:
 534                 if (freq.flr_flags & IPV6_FL_F_REFLECT) {
 535                         if (sk->sk_protocol != IPPROTO_TCP)
 536                                 return -ENOPROTOOPT;
 537                         if (!np->repflow)
 538                                 return -ESRCH;
 539                         np->flow_label = 0;
 540                         np->repflow = 0;
 541                         return 0;
 542                 }
 543                 spin_lock_bh(&ip6_sk_fl_lock);
 544                 for (sflp = &np->ipv6_fl_list;
 545                      (sfl = rcu_dereference_protected(*sflp,
 546                                                       lockdep_is_held(&ip6_sk_fl_lock))) != NULL;
 547                      sflp = &sfl->next) {
 548                         if (sfl->fl->label == freq.flr_label) {
 549                                 if (freq.flr_label == (np->flow_label&IPV6_FLOWLABEL_MASK))
 550                                         np->flow_label &= ~IPV6_FLOWLABEL_MASK;
 551                                 *sflp = sfl->next;
 552                                 spin_unlock_bh(&ip6_sk_fl_lock);
 553                                 fl_release(sfl->fl);
 554                                 kfree_rcu(sfl, rcu);
 555                                 return 0;
 556                         }
 557                 }
 558                 spin_unlock_bh(&ip6_sk_fl_lock);
 559                 return -ESRCH;
 560
 561         case IPV6_FL_A_RENEW:
 562                 rcu_read_lock_bh();
 563                 for_each_sk_fl_rcu(np, sfl) {
 564                         if (sfl->fl->label == freq.flr_label) {
 565                                 err = fl6_renew(sfl->fl, freq.flr_linger, freq.flr_expires);
 566                                 rcu_read_unlock_bh();
 567                                 return err;
 568                         }
 569                 }
 570                 rcu_read_unlock_bh();
 571
 572                 if (freq.flr_share == IPV6_FL_S_NONE &&
 573                     ns_capable(net->user_ns, CAP_NET_ADMIN)) {
 574                         fl = fl_lookup(net, freq.flr_label);
 575                         if (fl) {
 576                                 err = fl6_renew(fl, freq.flr_linger, freq.flr_expires);
 577                                 fl_release(fl);
 578                                 return err;
 579                         }
 580                 }
 581                 return -ESRCH;
 582
 583         case IPV6_FL_A_GET:
 584                 if (freq.flr_flags & IPV6_FL_F_REFLECT) {
 585                         struct net *net = sock_net(sk);
 586                         if (net->ipv6.sysctl.flowlabel_consistency) {
 587                                 net_info_ratelimited("Can not set IPV6_FL_F_REFLECT if flowlabel_consistency sysctl is enable\n");
 588                                 return -EPERM;
 589                         }
 590
 591                         if (sk->sk_protocol != IPPROTO_TCP)
 592                                 return -ENOPROTOOPT;
 593
 594                         np->repflow = 1;
 595                         return 0;
 596                 }
 597
 598                 if (freq.flr_label & ~IPV6_FLOWLABEL_MASK)
 599                         return -EINVAL;
 600
 601                 if (net->ipv6.sysctl.flowlabel_state_ranges &&
 602                     (freq.flr_label & IPV6_FLOWLABEL_STATELESS_FLAG))
 603                         return -ERANGE;
 604
 605                 fl = fl_create(net, sk, &freq, optval, optlen, &err);
 606                 if (!fl)
 607                         return err;
 608                 sfl1 = kmalloc(sizeof(*sfl1), GFP_KERNEL);
 609
 610                 if (freq.flr_label) {
 611                         err = -EEXIST;
 612                         rcu_read_lock_bh();
 613                         for_each_sk_fl_rcu(np, sfl) {
 614                                 if (sfl->fl->label == freq.flr_label) {
 615                                         if (freq.flr_flags&IPV6_FL_F_EXCL) {
 616                                                 rcu_read_unlock_bh();
 617                                                 goto done;
 618                                         }
 619                                         fl1 = sfl->fl;
 620                                         atomic_inc(&fl1->users);
 621                                         break;
 622                                 }
 623                         }
 624                         rcu_read_unlock_bh();
 625
 626                         if (!fl1)
 627                                 fl1 = fl_lookup(net, freq.flr_label);
 628                         if (fl1) {
 629 recheck:
 630                                 err = -EEXIST;
 631                                 if (freq.flr_flags&IPV6_FL_F_EXCL)
 632                                         goto release;
 633                                 err = -EPERM;
 634                                 if (fl1->share == IPV6_FL_S_EXCL ||
 635                                     fl1->share != fl->share ||
 636                                     ((fl1->share == IPV6_FL_S_PROCESS) &&
 637                                      (fl1->owner.pid == fl->owner.pid)) ||
 638                                     ((fl1->share == IPV6_FL_S_USER) &&
 639                                      uid_eq(fl1->owner.uid, fl->owner.uid)))
 640                                         goto release;
 641
 642                                 err = -ENOMEM;
 643                                 if (!sfl1)
 644                                         goto release;
 645                                 if (fl->linger > fl1->linger)
 646                                         fl1->linger = fl->linger;
 647                                 if ((long)(fl->expires - fl1->expires) > 0)
 648                                         fl1->expires = fl->expires;
 649                                 fl_link(np, sfl1, fl1);
 650                                 fl_free(fl);
 651                                 return 0;
 652
 653 release:
 654                                 fl_release(fl1);
 655                                 goto done;
 656                         }
 657                 }
 658                 err = -ENOENT;
 659                 if (!(freq.flr_flags&IPV6_FL_F_CREATE))
 660                         goto done;
 661
 662                 err = -ENOMEM;
 663                 if (!sfl1)
 664                         goto done;
 665
 666                 err = mem_check(sk);
 667                 if (err != 0)
 668                         goto done;
 669
 670                 fl1 = fl_intern(net, fl, freq.flr_label);
 671                 if (fl1)
 672                         goto recheck;
 673
 674                 if (!freq.flr_label) {
 675                         if (copy_to_user(&((struct in6_flowlabel_req __user *) optval)->flr_label,
 676                                          &fl->label, sizeof(fl->label))) {
 677                                 /* Intentionally ignore fault. */
 678                         }
 679                 }
 680
 681                 fl_link(np, sfl1, fl);
 682                 return 0;
 683
 684         default:
 685                 return -EINVAL;
 686         }
 687
 688 done:
 689         fl_free(fl);
 690         kfree(sfl1);
 691         return err;
 692 }
 693
 694 #ifdef CONFIG_PROC_FS
 695
 696 struct ip6fl_iter_state {
 697         struct seq_net_private p;
 698         struct pid_namespace *pid_ns;
 699         int bucket;
 700 };
 701
 702 #define ip6fl_seq_private(seq)  ((struct ip6fl_iter_state *)(seq)->private)
 703
 704 static struct ip6_flowlabel *ip6fl_get_first(struct seq_file *seq)
 705 {
 706         struct ip6_flowlabel *fl = NULL;
 707         struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 708         struct net *net = seq_file_net(seq);
 709
 710         for (state->bucket = 0; state->bucket <= FL_HASH_MASK; ++state->bucket) {
 711                 for_each_fl_rcu(state->bucket, fl) {
 712                         if (net_eq(fl->fl_net, net))
 713                                 goto out;
 714                 }
 715         }
 716         fl = NULL;
 717 out:
 718         return fl;
 719 }
 720
 721 static struct ip6_flowlabel *ip6fl_get_next(struct seq_file *seq, struct ip6_flowlabel *fl)
 722 {
 723         struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 724         struct net *net = seq_file_net(seq);
 725
 726         for_each_fl_continue_rcu(fl) {
 727                 if (net_eq(fl->fl_net, net))
 728                         goto out;
 729         }
 730
 731 try_again:
 732         if (++state->bucket <= FL_HASH_MASK) {
 733                 for_each_fl_rcu(state->bucket, fl) {
 734                         if (net_eq(fl->fl_net, net))
 735                                 goto out;
 736                 }
 737                 goto try_again;
 738         }
 739         fl = NULL;
 740
 741 out:
 742         return fl;
 743 }
 744
 745 static struct ip6_flowlabel *ip6fl_get_idx(struct seq_file *seq, loff_t pos)
 746 {
 747         struct ip6_flowlabel *fl = ip6fl_get_first(seq);
 748         if (fl)
 749                 while (pos && (fl = ip6fl_get_next(seq, fl)) != NULL)
 750                         --pos;
 751         return pos ? NULL : fl;
 752 }
 753
 754 static void *ip6fl_seq_start(struct seq_file *seq, loff_t *pos)
 755         __acquires(RCU)
 756 {
 757         rcu_read_lock_bh();
 758         return *pos ? ip6fl_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
 759 }
 760
 761 static void *ip6fl_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 762 {
 763         struct ip6_flowlabel *fl;
 764
 765         if (v == SEQ_START_TOKEN)
 766                 fl = ip6fl_get_first(seq);
 767         else
 768                 fl = ip6fl_get_next(seq, v);
 769         ++*pos;
 770         return fl;
 771 }
 772
 773 static void ip6fl_seq_stop(struct seq_file *seq, void *v)
 774         __releases(RCU)
 775 {
 776         rcu_read_unlock_bh();
 777 }
 778
 779 static int ip6fl_seq_show(struct seq_file *seq, void *v)
 780 {
 781         struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 782         if (v == SEQ_START_TOKEN) {
 783                 seq_puts(seq, "Label S Owner  Users  Linger Expires  Dst                              Opt\n");
 784         } else {
 785                 struct ip6_flowlabel *fl = v;
 786                 seq_printf(seq,
 787                            "%05X %-1d %-6d %-6d %-6ld %-8ld %pi6 %-4d\n",
 788                            (unsigned int)ntohl(fl->label),
 789                            fl->share,
 790                            ((fl->share == IPV6_FL_S_PROCESS) ?
 791                             pid_nr_ns(fl->owner.pid, state->pid_ns) :
 792                             ((fl->share == IPV6_FL_S_USER) ?
 793                              from_kuid_munged(seq_user_ns(seq), fl->owner.uid) :
 794                              0)),
 795                            atomic_read(&fl->users),
 796                            fl->linger/HZ,
 797                            (long)(fl->expires - jiffies)/HZ,
 798                            &fl->dst,
 799                            fl->opt ? fl->opt->opt_nflen : 0);
 800         }
 801         return 0;
 802 }
 803
 804 static const struct seq_operations ip6fl_seq_ops = {
 805         .start  =       ip6fl_seq_start,
 806         .next   =       ip6fl_seq_next,
 807         .stop   =       ip6fl_seq_stop,
 808         .show   =       ip6fl_seq_show,
 809 };
 810
 811 static int ip6fl_seq_open(struct inode *inode, struct file *file)
 812 {
 813         struct seq_file *seq;
 814         struct ip6fl_iter_state *state;
 815         int err;
 816
 817         err = seq_open_net(inode, file, &ip6fl_seq_ops,
 818                            sizeof(struct ip6fl_iter_state));
 819
 820         if (!err) {
 821                 seq = file->private_data;
 822                 state = ip6fl_seq_private(seq);
 823                 rcu_read_lock();
 824                 state->pid_ns = get_pid_ns(task_active_pid_ns(current));
 825                 rcu_read_unlock();
 826         }
 827         return err;
 828 }
 829
 830 static int ip6fl_seq_release(struct inode *inode, struct file *file)
 831 {
 832         struct seq_file *seq = file->private_data;
 833         struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 834         put_pid_ns(state->pid_ns);
 835         return seq_release_net(inode, file);
 836 }
 837
 838 static const struct file_operations ip6fl_seq_fops = {
 839         .owner          =       THIS_MODULE,
 840         .open           =       ip6fl_seq_open,
 841         .read           =       seq_read,
 842         .llseek         =       seq_lseek,
 843         .release        =       ip6fl_seq_release,
 844 };
 845
 846 static int __net_init ip6_flowlabel_proc_init(struct net *net)
 847 {
 848         if (!proc_create("ip6_flowlabel", S_IRUGO, net->proc_net,
 849                          &ip6fl_seq_fops))
 850                 return -ENOMEM;
 851         return 0;
 852 }
 853
 854 static void __net_exit ip6_flowlabel_proc_fini(struct net *net)
 855 {
 856         remove_proc_entry("ip6_flowlabel", net->proc_net);
 857 }
 858 #else
 859 static inline int ip6_flowlabel_proc_init(struct net *net)
 860 {
 861         return 0;
 862 }
 863 static inline void ip6_flowlabel_proc_fini(struct net *net)
 864 {
 865 }
 866 #endif
 867
 868 static void __net_exit ip6_flowlabel_net_exit(struct net *net)
 869 {
 870         ip6_fl_purge(net);
 871         ip6_flowlabel_proc_fini(net);
 872 }
 873
 874 static struct pernet_operations ip6_flowlabel_net_ops = {
 875         .init = ip6_flowlabel_proc_init,
 876         .exit = ip6_flowlabel_net_exit,
 877 };
 878
 879 int ip6_flowlabel_init(void)
 880 {
 881         return register_pernet_subsys(&ip6_flowlabel_net_ops);
 882 }
 883
 884 void ip6_flowlabel_cleanup(void)
 885 {
 886         del_timer(&ip6_fl_gc_timer);
 887         unregister_pernet_subsys(&ip6_flowlabel_net_ops);
 888 }