tcp: account SYN-ACK timeouts & retransmissions
[linux-3.10.git] / 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/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
24 #include <net/net_namespace.h>
25 #include <net/sock.h>
26
27 #include <net/ipv6.h>
28 #include <net/ndisc.h>
29 #include <net/protocol.h>
30 #include <net/ip6_route.h>
31 #include <net/addrconf.h>
32 #include <net/rawv6.h>
33 #include <net/icmp.h>
34 #include <net/transp_v6.h>
35
36 #include <asm/uaccess.h>
37
38 #define FL_MIN_LINGER   6       /* Minimal linger. It is set to 6sec specified
39                                    in old IPv6 RFC. Well, it was reasonable value.
40                                  */
41 #define FL_MAX_LINGER   60      /* Maximal linger timeout */
42
43 /* FL hash table */
44
45 #define FL_MAX_PER_SOCK 32
46 #define FL_MAX_SIZE     4096
47 #define FL_HASH_MASK    255
48 #define FL_HASH(l)      (ntohl(l)&FL_HASH_MASK)
49
50 static atomic_t fl_size = ATOMIC_INIT(0);
51 static struct ip6_flowlabel *fl_ht[FL_HASH_MASK+1];
52
53 static void ip6_fl_gc(unsigned long dummy);
54 static DEFINE_TIMER(ip6_fl_gc_timer, ip6_fl_gc, 0, 0);
55
56 /* FL hash table lock: it protects only of GC */
57
58 static DEFINE_RWLOCK(ip6_fl_lock);
59
60 /* Big socket sock */
61
62 static DEFINE_RWLOCK(ip6_sk_fl_lock);
63
64
65 static inline struct ip6_flowlabel *__fl_lookup(struct net *net, __be32 label)
66 {
67         struct ip6_flowlabel *fl;
68
69         for (fl=fl_ht[FL_HASH(label)]; fl; fl = fl->next) {
70                 if (fl->label == label && net_eq(fl->fl_net, net))
71                         return fl;
72         }
73         return NULL;
74 }
75
76 static struct ip6_flowlabel *fl_lookup(struct net *net, __be32 label)
77 {
78         struct ip6_flowlabel *fl;
79
80         read_lock_bh(&ip6_fl_lock);
81         fl = __fl_lookup(net, label);
82         if (fl)
83                 atomic_inc(&fl->users);
84         read_unlock_bh(&ip6_fl_lock);
85         return fl;
86 }
87
88
89 static void fl_free(struct ip6_flowlabel *fl)
90 {
91         if (fl) {
92                 release_net(fl->fl_net);
93                 kfree(fl->opt);
94         }
95         kfree(fl);
96 }
97
98 static void fl_release(struct ip6_flowlabel *fl)
99 {
100         write_lock_bh(&ip6_fl_lock);
101
102         fl->lastuse = jiffies;
103         if (atomic_dec_and_test(&fl->users)) {
104                 unsigned long ttd = fl->lastuse + fl->linger;
105                 if (time_after(ttd, fl->expires))
106                         fl->expires = ttd;
107                 ttd = fl->expires;
108                 if (fl->opt && fl->share == IPV6_FL_S_EXCL) {
109                         struct ipv6_txoptions *opt = fl->opt;
110                         fl->opt = NULL;
111                         kfree(opt);
112                 }
113                 if (!timer_pending(&ip6_fl_gc_timer) ||
114                     time_after(ip6_fl_gc_timer.expires, ttd))
115                         mod_timer(&ip6_fl_gc_timer, ttd);
116         }
117         write_unlock_bh(&ip6_fl_lock);
118 }
119
120 static void ip6_fl_gc(unsigned long dummy)
121 {
122         int i;
123         unsigned long now = jiffies;
124         unsigned long sched = 0;
125
126         write_lock(&ip6_fl_lock);
127
128         for (i=0; i<=FL_HASH_MASK; i++) {
129                 struct ip6_flowlabel *fl, **flp;
130                 flp = &fl_ht[i];
131                 while ((fl=*flp) != NULL) {
132                         if (atomic_read(&fl->users) == 0) {
133                                 unsigned long ttd = fl->lastuse + fl->linger;
134                                 if (time_after(ttd, fl->expires))
135                                         fl->expires = ttd;
136                                 ttd = fl->expires;
137                                 if (time_after_eq(now, ttd)) {
138                                         *flp = fl->next;
139                                         fl_free(fl);
140                                         atomic_dec(&fl_size);
141                                         continue;
142                                 }
143                                 if (!sched || time_before(ttd, sched))
144                                         sched = ttd;
145                         }
146                         flp = &fl->next;
147                 }
148         }
149         if (!sched && atomic_read(&fl_size))
150                 sched = now + FL_MAX_LINGER;
151         if (sched) {
152                 mod_timer(&ip6_fl_gc_timer, sched);
153         }
154         write_unlock(&ip6_fl_lock);
155 }
156
157 static void ip6_fl_purge(struct net *net)
158 {
159         int i;
160
161         write_lock(&ip6_fl_lock);
162         for (i = 0; i <= FL_HASH_MASK; i++) {
163                 struct ip6_flowlabel *fl, **flp;
164                 flp = &fl_ht[i];
165                 while ((fl = *flp) != NULL) {
166                         if (net_eq(fl->fl_net, net) &&
167                             atomic_read(&fl->users) == 0) {
168                                 *flp = fl->next;
169                                 fl_free(fl);
170                                 atomic_dec(&fl_size);
171                                 continue;
172                         }
173                         flp = &fl->next;
174                 }
175         }
176         write_unlock(&ip6_fl_lock);
177 }
178
179 static struct ip6_flowlabel *fl_intern(struct net *net,
180                                        struct ip6_flowlabel *fl, __be32 label)
181 {
182         struct ip6_flowlabel *lfl;
183
184         fl->label = label & IPV6_FLOWLABEL_MASK;
185
186         write_lock_bh(&ip6_fl_lock);
187         if (label == 0) {
188                 for (;;) {
189                         fl->label = htonl(net_random())&IPV6_FLOWLABEL_MASK;
190                         if (fl->label) {
191                                 lfl = __fl_lookup(net, fl->label);
192                                 if (lfl == NULL)
193                                         break;
194                         }
195                 }
196         } else {
197                 /*
198                  * we dropper the ip6_fl_lock, so this entry could reappear
199                  * and we need to recheck with it.
200                  *
201                  * OTOH no need to search the active socket first, like it is
202                  * done in ipv6_flowlabel_opt - sock is locked, so new entry
203                  * with the same label can only appear on another sock
204                  */
205                 lfl = __fl_lookup(net, fl->label);
206                 if (lfl != NULL) {
207                         atomic_inc(&lfl->users);
208                         write_unlock_bh(&ip6_fl_lock);
209                         return lfl;
210                 }
211         }
212
213         fl->lastuse = jiffies;
214         fl->next = fl_ht[FL_HASH(fl->label)];
215         fl_ht[FL_HASH(fl->label)] = fl;
216         atomic_inc(&fl_size);
217         write_unlock_bh(&ip6_fl_lock);
218         return NULL;
219 }
220
221
222
223 /* Socket flowlabel lists */
224
225 struct ip6_flowlabel * fl6_sock_lookup(struct sock *sk, __be32 label)
226 {
227         struct ipv6_fl_socklist *sfl;
228         struct ipv6_pinfo *np = inet6_sk(sk);
229
230         label &= IPV6_FLOWLABEL_MASK;
231
232         read_lock_bh(&ip6_sk_fl_lock);
233         for (sfl=np->ipv6_fl_list; sfl; sfl = sfl->next) {
234                 struct ip6_flowlabel *fl = sfl->fl;
235                 if (fl->label == label) {
236                         fl->lastuse = jiffies;
237                         atomic_inc(&fl->users);
238                         read_unlock_bh(&ip6_sk_fl_lock);
239                         return fl;
240                 }
241         }
242         read_unlock_bh(&ip6_sk_fl_lock);
243         return NULL;
244 }
245
246 EXPORT_SYMBOL_GPL(fl6_sock_lookup);
247
248 void fl6_free_socklist(struct sock *sk)
249 {
250         struct ipv6_pinfo *np = inet6_sk(sk);
251         struct ipv6_fl_socklist *sfl;
252
253         while ((sfl = np->ipv6_fl_list) != NULL) {
254                 np->ipv6_fl_list = sfl->next;
255                 fl_release(sfl->fl);
256                 kfree(sfl);
257         }
258 }
259
260 /* Service routines */
261
262
263 /*
264    It is the only difficult place. flowlabel enforces equal headers
265    before and including routing header, however user may supply options
266    following rthdr.
267  */
268
269 struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions * opt_space,
270                                          struct ip6_flowlabel * fl,
271                                          struct ipv6_txoptions * fopt)
272 {
273         struct ipv6_txoptions * fl_opt = fl->opt;
274
275         if (fopt == NULL || fopt->opt_flen == 0)
276                 return fl_opt;
277
278         if (fl_opt != NULL) {
279                 opt_space->hopopt = fl_opt->hopopt;
280                 opt_space->dst0opt = fl_opt->dst0opt;
281                 opt_space->srcrt = fl_opt->srcrt;
282                 opt_space->opt_nflen = fl_opt->opt_nflen;
283         } else {
284                 if (fopt->opt_nflen == 0)
285                         return fopt;
286                 opt_space->hopopt = NULL;
287                 opt_space->dst0opt = NULL;
288                 opt_space->srcrt = NULL;
289                 opt_space->opt_nflen = 0;
290         }
291         opt_space->dst1opt = fopt->dst1opt;
292         opt_space->opt_flen = fopt->opt_flen;
293         return opt_space;
294 }
295
296 static unsigned long check_linger(unsigned long ttl)
297 {
298         if (ttl < FL_MIN_LINGER)
299                 return FL_MIN_LINGER*HZ;
300         if (ttl > FL_MAX_LINGER && !capable(CAP_NET_ADMIN))
301                 return 0;
302         return ttl*HZ;
303 }
304
305 static int fl6_renew(struct ip6_flowlabel *fl, unsigned long linger, unsigned long expires)
306 {
307         linger = check_linger(linger);
308         if (!linger)
309                 return -EPERM;
310         expires = check_linger(expires);
311         if (!expires)
312                 return -EPERM;
313         fl->lastuse = jiffies;
314         if (time_before(fl->linger, linger))
315                 fl->linger = linger;
316         if (time_before(expires, fl->linger))
317                 expires = fl->linger;
318         if (time_before(fl->expires, fl->lastuse + expires))
319                 fl->expires = fl->lastuse + expires;
320         return 0;
321 }
322
323 static struct ip6_flowlabel *
324 fl_create(struct net *net, struct in6_flowlabel_req *freq, char __user *optval,
325           int optlen, int *err_p)
326 {
327         struct ip6_flowlabel *fl = NULL;
328         int olen;
329         int addr_type;
330         int err;
331
332         olen = optlen - CMSG_ALIGN(sizeof(*freq));
333         err = -EINVAL;
334         if (olen > 64 * 1024)
335                 goto done;
336
337         err = -ENOMEM;
338         fl = kzalloc(sizeof(*fl), GFP_KERNEL);
339         if (fl == NULL)
340                 goto done;
341
342         if (olen > 0) {
343                 struct msghdr msg;
344                 struct flowi flowi;
345                 int junk;
346
347                 err = -ENOMEM;
348                 fl->opt = kmalloc(sizeof(*fl->opt) + olen, GFP_KERNEL);
349                 if (fl->opt == NULL)
350                         goto done;
351
352                 memset(fl->opt, 0, sizeof(*fl->opt));
353                 fl->opt->tot_len = sizeof(*fl->opt) + olen;
354                 err = -EFAULT;
355                 if (copy_from_user(fl->opt+1, optval+CMSG_ALIGN(sizeof(*freq)), olen))
356                         goto done;
357
358                 msg.msg_controllen = olen;
359                 msg.msg_control = (void*)(fl->opt+1);
360                 flowi.oif = 0;
361
362                 err = datagram_send_ctl(net, &msg, &flowi, fl->opt, &junk, &junk);
363                 if (err)
364                         goto done;
365                 err = -EINVAL;
366                 if (fl->opt->opt_flen)
367                         goto done;
368                 if (fl->opt->opt_nflen == 0) {
369                         kfree(fl->opt);
370                         fl->opt = NULL;
371                 }
372         }
373
374         fl->fl_net = hold_net(net);
375         fl->expires = jiffies;
376         err = fl6_renew(fl, freq->flr_linger, freq->flr_expires);
377         if (err)
378                 goto done;
379         fl->share = freq->flr_share;
380         addr_type = ipv6_addr_type(&freq->flr_dst);
381         if ((addr_type & IPV6_ADDR_MAPPED) ||
382             addr_type == IPV6_ADDR_ANY) {
383                 err = -EINVAL;
384                 goto done;
385         }
386         ipv6_addr_copy(&fl->dst, &freq->flr_dst);
387         atomic_set(&fl->users, 1);
388         switch (fl->share) {
389         case IPV6_FL_S_EXCL:
390         case IPV6_FL_S_ANY:
391                 break;
392         case IPV6_FL_S_PROCESS:
393                 fl->owner = current->pid;
394                 break;
395         case IPV6_FL_S_USER:
396                 fl->owner = current_euid();
397                 break;
398         default:
399                 err = -EINVAL;
400                 goto done;
401         }
402         return fl;
403
404 done:
405         fl_free(fl);
406         *err_p = err;
407         return NULL;
408 }
409
410 static int mem_check(struct sock *sk)
411 {
412         struct ipv6_pinfo *np = inet6_sk(sk);
413         struct ipv6_fl_socklist *sfl;
414         int room = FL_MAX_SIZE - atomic_read(&fl_size);
415         int count = 0;
416
417         if (room > FL_MAX_SIZE - FL_MAX_PER_SOCK)
418                 return 0;
419
420         for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next)
421                 count++;
422
423         if (room <= 0 ||
424             ((count >= FL_MAX_PER_SOCK ||
425               (count > 0 && room < FL_MAX_SIZE/2) || room < FL_MAX_SIZE/4) &&
426              !capable(CAP_NET_ADMIN)))
427                 return -ENOBUFS;
428
429         return 0;
430 }
431
432 static int ipv6_hdr_cmp(struct ipv6_opt_hdr *h1, struct ipv6_opt_hdr *h2)
433 {
434         if (h1 == h2)
435                 return 0;
436         if (h1 == NULL || h2 == NULL)
437                 return 1;
438         if (h1->hdrlen != h2->hdrlen)
439                 return 1;
440         return memcmp(h1+1, h2+1, ((h1->hdrlen+1)<<3) - sizeof(*h1));
441 }
442
443 static int ipv6_opt_cmp(struct ipv6_txoptions *o1, struct ipv6_txoptions *o2)
444 {
445         if (o1 == o2)
446                 return 0;
447         if (o1 == NULL || o2 == NULL)
448                 return 1;
449         if (o1->opt_nflen != o2->opt_nflen)
450                 return 1;
451         if (ipv6_hdr_cmp(o1->hopopt, o2->hopopt))
452                 return 1;
453         if (ipv6_hdr_cmp(o1->dst0opt, o2->dst0opt))
454                 return 1;
455         if (ipv6_hdr_cmp((struct ipv6_opt_hdr *)o1->srcrt, (struct ipv6_opt_hdr *)o2->srcrt))
456                 return 1;
457         return 0;
458 }
459
460 static inline void fl_link(struct ipv6_pinfo *np, struct ipv6_fl_socklist *sfl,
461                 struct ip6_flowlabel *fl)
462 {
463         write_lock_bh(&ip6_sk_fl_lock);
464         sfl->fl = fl;
465         sfl->next = np->ipv6_fl_list;
466         np->ipv6_fl_list = sfl;
467         write_unlock_bh(&ip6_sk_fl_lock);
468 }
469
470 int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen)
471 {
472         int uninitialized_var(err);
473         struct net *net = sock_net(sk);
474         struct ipv6_pinfo *np = inet6_sk(sk);
475         struct in6_flowlabel_req freq;
476         struct ipv6_fl_socklist *sfl1=NULL;
477         struct ipv6_fl_socklist *sfl, **sflp;
478         struct ip6_flowlabel *fl, *fl1 = NULL;
479
480
481         if (optlen < sizeof(freq))
482                 return -EINVAL;
483
484         if (copy_from_user(&freq, optval, sizeof(freq)))
485                 return -EFAULT;
486
487         switch (freq.flr_action) {
488         case IPV6_FL_A_PUT:
489                 write_lock_bh(&ip6_sk_fl_lock);
490                 for (sflp = &np->ipv6_fl_list; (sfl=*sflp)!=NULL; sflp = &sfl->next) {
491                         if (sfl->fl->label == freq.flr_label) {
492                                 if (freq.flr_label == (np->flow_label&IPV6_FLOWLABEL_MASK))
493                                         np->flow_label &= ~IPV6_FLOWLABEL_MASK;
494                                 *sflp = sfl->next;
495                                 write_unlock_bh(&ip6_sk_fl_lock);
496                                 fl_release(sfl->fl);
497                                 kfree(sfl);
498                                 return 0;
499                         }
500                 }
501                 write_unlock_bh(&ip6_sk_fl_lock);
502                 return -ESRCH;
503
504         case IPV6_FL_A_RENEW:
505                 read_lock_bh(&ip6_sk_fl_lock);
506                 for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next) {
507                         if (sfl->fl->label == freq.flr_label) {
508                                 err = fl6_renew(sfl->fl, freq.flr_linger, freq.flr_expires);
509                                 read_unlock_bh(&ip6_sk_fl_lock);
510                                 return err;
511                         }
512                 }
513                 read_unlock_bh(&ip6_sk_fl_lock);
514
515                 if (freq.flr_share == IPV6_FL_S_NONE && capable(CAP_NET_ADMIN)) {
516                         fl = fl_lookup(net, freq.flr_label);
517                         if (fl) {
518                                 err = fl6_renew(fl, freq.flr_linger, freq.flr_expires);
519                                 fl_release(fl);
520                                 return err;
521                         }
522                 }
523                 return -ESRCH;
524
525         case IPV6_FL_A_GET:
526                 if (freq.flr_label & ~IPV6_FLOWLABEL_MASK)
527                         return -EINVAL;
528
529                 fl = fl_create(net, &freq, optval, optlen, &err);
530                 if (fl == NULL)
531                         return err;
532                 sfl1 = kmalloc(sizeof(*sfl1), GFP_KERNEL);
533
534                 if (freq.flr_label) {
535                         err = -EEXIST;
536                         read_lock_bh(&ip6_sk_fl_lock);
537                         for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next) {
538                                 if (sfl->fl->label == freq.flr_label) {
539                                         if (freq.flr_flags&IPV6_FL_F_EXCL) {
540                                                 read_unlock_bh(&ip6_sk_fl_lock);
541                                                 goto done;
542                                         }
543                                         fl1 = sfl->fl;
544                                         atomic_inc(&fl1->users);
545                                         break;
546                                 }
547                         }
548                         read_unlock_bh(&ip6_sk_fl_lock);
549
550                         if (fl1 == NULL)
551                                 fl1 = fl_lookup(net, freq.flr_label);
552                         if (fl1) {
553 recheck:
554                                 err = -EEXIST;
555                                 if (freq.flr_flags&IPV6_FL_F_EXCL)
556                                         goto release;
557                                 err = -EPERM;
558                                 if (fl1->share == IPV6_FL_S_EXCL ||
559                                     fl1->share != fl->share ||
560                                     fl1->owner != fl->owner)
561                                         goto release;
562
563                                 err = -EINVAL;
564                                 if (!ipv6_addr_equal(&fl1->dst, &fl->dst) ||
565                                     ipv6_opt_cmp(fl1->opt, fl->opt))
566                                         goto release;
567
568                                 err = -ENOMEM;
569                                 if (sfl1 == NULL)
570                                         goto release;
571                                 if (fl->linger > fl1->linger)
572                                         fl1->linger = fl->linger;
573                                 if ((long)(fl->expires - fl1->expires) > 0)
574                                         fl1->expires = fl->expires;
575                                 fl_link(np, sfl1, fl1);
576                                 fl_free(fl);
577                                 return 0;
578
579 release:
580                                 fl_release(fl1);
581                                 goto done;
582                         }
583                 }
584                 err = -ENOENT;
585                 if (!(freq.flr_flags&IPV6_FL_F_CREATE))
586                         goto done;
587
588                 err = -ENOMEM;
589                 if (sfl1 == NULL || (err = mem_check(sk)) != 0)
590                         goto done;
591
592                 fl1 = fl_intern(net, fl, freq.flr_label);
593                 if (fl1 != NULL)
594                         goto recheck;
595
596                 if (!freq.flr_label) {
597                         if (copy_to_user(&((struct in6_flowlabel_req __user *) optval)->flr_label,
598                                          &fl->label, sizeof(fl->label))) {
599                                 /* Intentionally ignore fault. */
600                         }
601                 }
602
603                 fl_link(np, sfl1, fl);
604                 return 0;
605
606         default:
607                 return -EINVAL;
608         }
609
610 done:
611         fl_free(fl);
612         kfree(sfl1);
613         return err;
614 }
615
616 #ifdef CONFIG_PROC_FS
617
618 struct ip6fl_iter_state {
619         struct seq_net_private p;
620         int bucket;
621 };
622
623 #define ip6fl_seq_private(seq)  ((struct ip6fl_iter_state *)(seq)->private)
624
625 static struct ip6_flowlabel *ip6fl_get_first(struct seq_file *seq)
626 {
627         struct ip6_flowlabel *fl = NULL;
628         struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
629         struct net *net = seq_file_net(seq);
630
631         for (state->bucket = 0; state->bucket <= FL_HASH_MASK; ++state->bucket) {
632                 fl = fl_ht[state->bucket];
633
634                 while (fl && !net_eq(fl->fl_net, net))
635                         fl = fl->next;
636                 if (fl)
637                         break;
638         }
639         return fl;
640 }
641
642 static struct ip6_flowlabel *ip6fl_get_next(struct seq_file *seq, struct ip6_flowlabel *fl)
643 {
644         struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
645         struct net *net = seq_file_net(seq);
646
647         fl = fl->next;
648 try_again:
649         while (fl && !net_eq(fl->fl_net, net))
650                 fl = fl->next;
651
652         while (!fl) {
653                 if (++state->bucket <= FL_HASH_MASK) {
654                         fl = fl_ht[state->bucket];
655                         goto try_again;
656                 } else
657                         break;
658         }
659         return fl;
660 }
661
662 static struct ip6_flowlabel *ip6fl_get_idx(struct seq_file *seq, loff_t pos)
663 {
664         struct ip6_flowlabel *fl = ip6fl_get_first(seq);
665         if (fl)
666                 while (pos && (fl = ip6fl_get_next(seq, fl)) != NULL)
667                         --pos;
668         return pos ? NULL : fl;
669 }
670
671 static void *ip6fl_seq_start(struct seq_file *seq, loff_t *pos)
672         __acquires(ip6_fl_lock)
673 {
674         read_lock_bh(&ip6_fl_lock);
675         return *pos ? ip6fl_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
676 }
677
678 static void *ip6fl_seq_next(struct seq_file *seq, void *v, loff_t *pos)
679 {
680         struct ip6_flowlabel *fl;
681
682         if (v == SEQ_START_TOKEN)
683                 fl = ip6fl_get_first(seq);
684         else
685                 fl = ip6fl_get_next(seq, v);
686         ++*pos;
687         return fl;
688 }
689
690 static void ip6fl_seq_stop(struct seq_file *seq, void *v)
691         __releases(ip6_fl_lock)
692 {
693         read_unlock_bh(&ip6_fl_lock);
694 }
695
696 static int ip6fl_seq_show(struct seq_file *seq, void *v)
697 {
698         if (v == SEQ_START_TOKEN)
699                 seq_printf(seq, "%-5s %-1s %-6s %-6s %-6s %-8s %-32s %s\n",
700                            "Label", "S", "Owner", "Users", "Linger", "Expires", "Dst", "Opt");
701         else {
702                 struct ip6_flowlabel *fl = v;
703                 seq_printf(seq,
704                            "%05X %-1d %-6d %-6d %-6ld %-8ld %pi6 %-4d\n",
705                            (unsigned)ntohl(fl->label),
706                            fl->share,
707                            (unsigned)fl->owner,
708                            atomic_read(&fl->users),
709                            fl->linger/HZ,
710                            (long)(fl->expires - jiffies)/HZ,
711                            &fl->dst,
712                            fl->opt ? fl->opt->opt_nflen : 0);
713         }
714         return 0;
715 }
716
717 static const struct seq_operations ip6fl_seq_ops = {
718         .start  =       ip6fl_seq_start,
719         .next   =       ip6fl_seq_next,
720         .stop   =       ip6fl_seq_stop,
721         .show   =       ip6fl_seq_show,
722 };
723
724 static int ip6fl_seq_open(struct inode *inode, struct file *file)
725 {
726         return seq_open_net(inode, file, &ip6fl_seq_ops,
727                             sizeof(struct ip6fl_iter_state));
728 }
729
730 static const struct file_operations ip6fl_seq_fops = {
731         .owner          =       THIS_MODULE,
732         .open           =       ip6fl_seq_open,
733         .read           =       seq_read,
734         .llseek         =       seq_lseek,
735         .release        =       seq_release_net,
736 };
737
738 static int ip6_flowlabel_proc_init(struct net *net)
739 {
740         if (!proc_net_fops_create(net, "ip6_flowlabel",
741                                   S_IRUGO, &ip6fl_seq_fops))
742                 return -ENOMEM;
743         return 0;
744 }
745
746 static void ip6_flowlabel_proc_fini(struct net *net)
747 {
748         proc_net_remove(net, "ip6_flowlabel");
749 }
750 #else
751 static inline int ip6_flowlabel_proc_init(struct net *net)
752 {
753         return 0;
754 }
755 static inline void ip6_flowlabel_proc_fini(struct net *net)
756 {
757         return ;
758 }
759 #endif
760
761 static inline void ip6_flowlabel_net_exit(struct net *net)
762 {
763         ip6_fl_purge(net);
764         ip6_flowlabel_proc_fini(net);
765 }
766
767 static struct pernet_operations ip6_flowlabel_net_ops = {
768         .init = ip6_flowlabel_proc_init,
769         .exit = ip6_flowlabel_net_exit,
770 };
771
772 int ip6_flowlabel_init(void)
773 {
774         return register_pernet_subsys(&ip6_flowlabel_net_ops);
775 }
776
777 void ip6_flowlabel_cleanup(void)
778 {
779         del_timer(&ip6_fl_gc_timer);
780         unregister_pernet_subsys(&ip6_flowlabel_net_ops);
781 }