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TOMOYO Linux Cross Reference
Linux/net/ipv6/ip6_flowlabel.c

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  1 /*
  2  *      ip6_flowlabel.c         IPv6 flowlabel manager.
  3  *
  4  *      This program is free software; you can redistribute it and/or
  5  *      modify it under the terms of the GNU General Public License
  6  *      as published by the Free Software Foundation; either version
  7  *      2 of the License, or (at your option) any later version.
  8  *
  9  *      Authors:        Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
 10  */
 11 
 12 #include <linux/capability.h>
 13 #include <linux/errno.h>
 14 #include <linux/types.h>
 15 #include <linux/socket.h>
 16 #include <linux/net.h>
 17 #include <linux/netdevice.h>
 18 #include <linux/in6.h>
 19 #include <linux/proc_fs.h>
 20 #include <linux/seq_file.h>
 21 #include <linux/slab.h>
 22 #include <linux/export.h>
 23 #include <linux/pid_namespace.h>
 24 
 25 #include <net/net_namespace.h>
 26 #include <net/sock.h>
 27 
 28 #include <net/ipv6.h>
 29 #include <net/rawv6.h>
 30 #include <net/transp_v6.h>
 31 
 32 #include <asm/uaccess.h>
 33 
 34 #define FL_MIN_LINGER   6       /* Minimal linger. It is set to 6sec specified
 35                                    in old IPv6 RFC. Well, it was reasonable value.
 36                                  */
 37 #define FL_MAX_LINGER   150     /* Maximal linger timeout */
 38 
 39 /* FL hash table */
 40 
 41 #define FL_MAX_PER_SOCK 32
 42 #define FL_MAX_SIZE     4096
 43 #define FL_HASH_MASK    255
 44 #define FL_HASH(l)      (ntohl(l)&FL_HASH_MASK)
 45 
 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         return opt_space;
319 }
320 EXPORT_SYMBOL_GPL(fl6_merge_options);
321 
322 static 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 
331 static 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 
353 static struct ip6_flowlabel *
354 fl_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 
436 done:
437         fl_free(fl);
438         *err_p = err;
439         return NULL;
440 }
441 
442 static 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 
466 static 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 
476 int 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 
513 int 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) {
628 recheck:
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 
652 release:
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 
687 done:
688         fl_free(fl);
689         kfree(sfl1);
690         return err;
691 }
692 
693 #ifdef CONFIG_PROC_FS
694 
695 struct 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 
703 static 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;
716 out:
717         return fl;
718 }
719 
720 static 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 
730 try_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 
740 out:
741         return fl;
742 }
743 
744 static 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 
753 static 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 
760 static 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 
772 static void ip6fl_seq_stop(struct seq_file *seq, void *v)
773         __releases(RCU)
774 {
775         rcu_read_unlock_bh();
776 }
777 
778 static 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 
803 static 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 
810 static 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 
829 static 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 
837 static 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 
845 static 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 
853 static void __net_exit ip6_flowlabel_proc_fini(struct net *net)
854 {
855         remove_proc_entry("ip6_flowlabel", net->proc_net);
856 }
857 #else
858 static inline int ip6_flowlabel_proc_init(struct net *net)
859 {
860         return 0;
861 }
862 static inline void ip6_flowlabel_proc_fini(struct net *net)
863 {
864 }
865 #endif
866 
867 static void __net_exit ip6_flowlabel_net_exit(struct net *net)
868 {
869         ip6_fl_purge(net);
870         ip6_flowlabel_proc_fini(net);
871 }
872 
873 static struct pernet_operations ip6_flowlabel_net_ops = {
874         .init = ip6_flowlabel_proc_init,
875         .exit = ip6_flowlabel_net_exit,
876 };
877 
878 int ip6_flowlabel_init(void)
879 {
880         return register_pernet_subsys(&ip6_flowlabel_net_ops);
881 }
882 
883 void ip6_flowlabel_cleanup(void)
884 {
885         del_timer(&ip6_fl_gc_timer);
886         unregister_pernet_subsys(&ip6_flowlabel_net_ops);
887 }
888 

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