[NETNS]: Tcp-v6 sockets per-net lookup.
[linux-2.6] / 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(__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)
71                         return fl;
72         }
73         return NULL;
74 }
75
76 static struct ip6_flowlabel * fl_lookup(__be32 label)
77 {
78         struct ip6_flowlabel *fl;
79
80         read_lock_bh(&ip6_fl_lock);
81         fl = __fl_lookup(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                 kfree(fl->opt);
93         kfree(fl);
94 }
95
96 static void fl_release(struct ip6_flowlabel *fl)
97 {
98         write_lock_bh(&ip6_fl_lock);
99
100         fl->lastuse = jiffies;
101         if (atomic_dec_and_test(&fl->users)) {
102                 unsigned long ttd = fl->lastuse + fl->linger;
103                 if (time_after(ttd, fl->expires))
104                         fl->expires = ttd;
105                 ttd = fl->expires;
106                 if (fl->opt && fl->share == IPV6_FL_S_EXCL) {
107                         struct ipv6_txoptions *opt = fl->opt;
108                         fl->opt = NULL;
109                         kfree(opt);
110                 }
111                 if (!timer_pending(&ip6_fl_gc_timer) ||
112                     time_after(ip6_fl_gc_timer.expires, ttd))
113                         mod_timer(&ip6_fl_gc_timer, ttd);
114         }
115
116         write_unlock_bh(&ip6_fl_lock);
117 }
118
119 static void ip6_fl_gc(unsigned long dummy)
120 {
121         int i;
122         unsigned long now = jiffies;
123         unsigned long sched = 0;
124
125         write_lock(&ip6_fl_lock);
126
127         for (i=0; i<=FL_HASH_MASK; i++) {
128                 struct ip6_flowlabel *fl, **flp;
129                 flp = &fl_ht[i];
130                 while ((fl=*flp) != NULL) {
131                         if (atomic_read(&fl->users) == 0) {
132                                 unsigned long ttd = fl->lastuse + fl->linger;
133                                 if (time_after(ttd, fl->expires))
134                                         fl->expires = ttd;
135                                 ttd = fl->expires;
136                                 if (time_after_eq(now, ttd)) {
137                                         *flp = fl->next;
138                                         fl_free(fl);
139                                         atomic_dec(&fl_size);
140                                         continue;
141                                 }
142                                 if (!sched || time_before(ttd, sched))
143                                         sched = ttd;
144                         }
145                         flp = &fl->next;
146                 }
147         }
148         if (!sched && atomic_read(&fl_size))
149                 sched = now + FL_MAX_LINGER;
150         if (sched) {
151                 ip6_fl_gc_timer.expires = sched;
152                 add_timer(&ip6_fl_gc_timer);
153         }
154         write_unlock(&ip6_fl_lock);
155 }
156
157 static struct ip6_flowlabel *fl_intern(struct ip6_flowlabel *fl, __be32 label)
158 {
159         struct ip6_flowlabel *lfl;
160
161         fl->label = label & IPV6_FLOWLABEL_MASK;
162
163         write_lock_bh(&ip6_fl_lock);
164         if (label == 0) {
165                 for (;;) {
166                         fl->label = htonl(net_random())&IPV6_FLOWLABEL_MASK;
167                         if (fl->label) {
168                                 lfl = __fl_lookup(fl->label);
169                                 if (lfl == NULL)
170                                         break;
171                         }
172                 }
173         } else {
174                 /*
175                  * we dropper the ip6_fl_lock, so this entry could reappear
176                  * and we need to recheck with it.
177                  *
178                  * OTOH no need to search the active socket first, like it is
179                  * done in ipv6_flowlabel_opt - sock is locked, so new entry
180                  * with the same label can only appear on another sock
181                  */
182                 lfl = __fl_lookup(fl->label);
183                 if (lfl != NULL) {
184                         atomic_inc(&lfl->users);
185                         write_unlock_bh(&ip6_fl_lock);
186                         return lfl;
187                 }
188         }
189
190         fl->lastuse = jiffies;
191         fl->next = fl_ht[FL_HASH(fl->label)];
192         fl_ht[FL_HASH(fl->label)] = fl;
193         atomic_inc(&fl_size);
194         write_unlock_bh(&ip6_fl_lock);
195         return NULL;
196 }
197
198
199
200 /* Socket flowlabel lists */
201
202 struct ip6_flowlabel * fl6_sock_lookup(struct sock *sk, __be32 label)
203 {
204         struct ipv6_fl_socklist *sfl;
205         struct ipv6_pinfo *np = inet6_sk(sk);
206
207         label &= IPV6_FLOWLABEL_MASK;
208
209         read_lock_bh(&ip6_sk_fl_lock);
210         for (sfl=np->ipv6_fl_list; sfl; sfl = sfl->next) {
211                 struct ip6_flowlabel *fl = sfl->fl;
212                 if (fl->label == label) {
213                         fl->lastuse = jiffies;
214                         atomic_inc(&fl->users);
215                         read_unlock_bh(&ip6_sk_fl_lock);
216                         return fl;
217                 }
218         }
219         read_unlock_bh(&ip6_sk_fl_lock);
220         return NULL;
221 }
222
223 EXPORT_SYMBOL_GPL(fl6_sock_lookup);
224
225 void fl6_free_socklist(struct sock *sk)
226 {
227         struct ipv6_pinfo *np = inet6_sk(sk);
228         struct ipv6_fl_socklist *sfl;
229
230         while ((sfl = np->ipv6_fl_list) != NULL) {
231                 np->ipv6_fl_list = sfl->next;
232                 fl_release(sfl->fl);
233                 kfree(sfl);
234         }
235 }
236
237 /* Service routines */
238
239
240 /*
241    It is the only difficult place. flowlabel enforces equal headers
242    before and including routing header, however user may supply options
243    following rthdr.
244  */
245
246 struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions * opt_space,
247                                          struct ip6_flowlabel * fl,
248                                          struct ipv6_txoptions * fopt)
249 {
250         struct ipv6_txoptions * fl_opt = fl->opt;
251
252         if (fopt == NULL || fopt->opt_flen == 0)
253                 return fl_opt;
254
255         if (fl_opt != NULL) {
256                 opt_space->hopopt = fl_opt->hopopt;
257                 opt_space->dst0opt = fl_opt->dst0opt;
258                 opt_space->srcrt = fl_opt->srcrt;
259                 opt_space->opt_nflen = fl_opt->opt_nflen;
260         } else {
261                 if (fopt->opt_nflen == 0)
262                         return fopt;
263                 opt_space->hopopt = NULL;
264                 opt_space->dst0opt = NULL;
265                 opt_space->srcrt = NULL;
266                 opt_space->opt_nflen = 0;
267         }
268         opt_space->dst1opt = fopt->dst1opt;
269         opt_space->opt_flen = fopt->opt_flen;
270         return opt_space;
271 }
272
273 static unsigned long check_linger(unsigned long ttl)
274 {
275         if (ttl < FL_MIN_LINGER)
276                 return FL_MIN_LINGER*HZ;
277         if (ttl > FL_MAX_LINGER && !capable(CAP_NET_ADMIN))
278                 return 0;
279         return ttl*HZ;
280 }
281
282 static int fl6_renew(struct ip6_flowlabel *fl, unsigned long linger, unsigned long expires)
283 {
284         linger = check_linger(linger);
285         if (!linger)
286                 return -EPERM;
287         expires = check_linger(expires);
288         if (!expires)
289                 return -EPERM;
290         fl->lastuse = jiffies;
291         if (time_before(fl->linger, linger))
292                 fl->linger = linger;
293         if (time_before(expires, fl->linger))
294                 expires = fl->linger;
295         if (time_before(fl->expires, fl->lastuse + expires))
296                 fl->expires = fl->lastuse + expires;
297         return 0;
298 }
299
300 static struct ip6_flowlabel *
301 fl_create(struct in6_flowlabel_req *freq, char __user *optval, int optlen, int *err_p)
302 {
303         struct ip6_flowlabel *fl;
304         int olen;
305         int addr_type;
306         int err;
307
308         err = -ENOMEM;
309         fl = kzalloc(sizeof(*fl), GFP_KERNEL);
310         if (fl == NULL)
311                 goto done;
312
313         olen = optlen - CMSG_ALIGN(sizeof(*freq));
314         if (olen > 0) {
315                 struct msghdr msg;
316                 struct flowi flowi;
317                 int junk;
318
319                 err = -ENOMEM;
320                 fl->opt = kmalloc(sizeof(*fl->opt) + olen, GFP_KERNEL);
321                 if (fl->opt == NULL)
322                         goto done;
323
324                 memset(fl->opt, 0, sizeof(*fl->opt));
325                 fl->opt->tot_len = sizeof(*fl->opt) + olen;
326                 err = -EFAULT;
327                 if (copy_from_user(fl->opt+1, optval+CMSG_ALIGN(sizeof(*freq)), olen))
328                         goto done;
329
330                 msg.msg_controllen = olen;
331                 msg.msg_control = (void*)(fl->opt+1);
332                 flowi.oif = 0;
333
334                 err = datagram_send_ctl(&msg, &flowi, fl->opt, &junk, &junk);
335                 if (err)
336                         goto done;
337                 err = -EINVAL;
338                 if (fl->opt->opt_flen)
339                         goto done;
340                 if (fl->opt->opt_nflen == 0) {
341                         kfree(fl->opt);
342                         fl->opt = NULL;
343                 }
344         }
345
346         fl->expires = jiffies;
347         err = fl6_renew(fl, freq->flr_linger, freq->flr_expires);
348         if (err)
349                 goto done;
350         fl->share = freq->flr_share;
351         addr_type = ipv6_addr_type(&freq->flr_dst);
352         if ((addr_type&IPV6_ADDR_MAPPED)
353             || addr_type == IPV6_ADDR_ANY) {
354                 err = -EINVAL;
355                 goto done;
356         }
357         ipv6_addr_copy(&fl->dst, &freq->flr_dst);
358         atomic_set(&fl->users, 1);
359         switch (fl->share) {
360         case IPV6_FL_S_EXCL:
361         case IPV6_FL_S_ANY:
362                 break;
363         case IPV6_FL_S_PROCESS:
364                 fl->owner = current->pid;
365                 break;
366         case IPV6_FL_S_USER:
367                 fl->owner = current->euid;
368                 break;
369         default:
370                 err = -EINVAL;
371                 goto done;
372         }
373         return fl;
374
375 done:
376         fl_free(fl);
377         *err_p = err;
378         return NULL;
379 }
380
381 static int mem_check(struct sock *sk)
382 {
383         struct ipv6_pinfo *np = inet6_sk(sk);
384         struct ipv6_fl_socklist *sfl;
385         int room = FL_MAX_SIZE - atomic_read(&fl_size);
386         int count = 0;
387
388         if (room > FL_MAX_SIZE - FL_MAX_PER_SOCK)
389                 return 0;
390
391         for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next)
392                 count++;
393
394         if (room <= 0 ||
395             ((count >= FL_MAX_PER_SOCK ||
396              (count > 0 && room < FL_MAX_SIZE/2) || room < FL_MAX_SIZE/4)
397              && !capable(CAP_NET_ADMIN)))
398                 return -ENOBUFS;
399
400         return 0;
401 }
402
403 static int ipv6_hdr_cmp(struct ipv6_opt_hdr *h1, struct ipv6_opt_hdr *h2)
404 {
405         if (h1 == h2)
406                 return 0;
407         if (h1 == NULL || h2 == NULL)
408                 return 1;
409         if (h1->hdrlen != h2->hdrlen)
410                 return 1;
411         return memcmp(h1+1, h2+1, ((h1->hdrlen+1)<<3) - sizeof(*h1));
412 }
413
414 static int ipv6_opt_cmp(struct ipv6_txoptions *o1, struct ipv6_txoptions *o2)
415 {
416         if (o1 == o2)
417                 return 0;
418         if (o1 == NULL || o2 == NULL)
419                 return 1;
420         if (o1->opt_nflen != o2->opt_nflen)
421                 return 1;
422         if (ipv6_hdr_cmp(o1->hopopt, o2->hopopt))
423                 return 1;
424         if (ipv6_hdr_cmp(o1->dst0opt, o2->dst0opt))
425                 return 1;
426         if (ipv6_hdr_cmp((struct ipv6_opt_hdr *)o1->srcrt, (struct ipv6_opt_hdr *)o2->srcrt))
427                 return 1;
428         return 0;
429 }
430
431 static inline void fl_link(struct ipv6_pinfo *np, struct ipv6_fl_socklist *sfl,
432                 struct ip6_flowlabel *fl)
433 {
434         write_lock_bh(&ip6_sk_fl_lock);
435         sfl->fl = fl;
436         sfl->next = np->ipv6_fl_list;
437         np->ipv6_fl_list = sfl;
438         write_unlock_bh(&ip6_sk_fl_lock);
439 }
440
441 int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen)
442 {
443         int err;
444         struct ipv6_pinfo *np = inet6_sk(sk);
445         struct in6_flowlabel_req freq;
446         struct ipv6_fl_socklist *sfl1=NULL;
447         struct ipv6_fl_socklist *sfl, **sflp;
448         struct ip6_flowlabel *fl, *fl1 = NULL;
449
450
451         if (optlen < sizeof(freq))
452                 return -EINVAL;
453
454         if (copy_from_user(&freq, optval, sizeof(freq)))
455                 return -EFAULT;
456
457         switch (freq.flr_action) {
458         case IPV6_FL_A_PUT:
459                 write_lock_bh(&ip6_sk_fl_lock);
460                 for (sflp = &np->ipv6_fl_list; (sfl=*sflp)!=NULL; sflp = &sfl->next) {
461                         if (sfl->fl->label == freq.flr_label) {
462                                 if (freq.flr_label == (np->flow_label&IPV6_FLOWLABEL_MASK))
463                                         np->flow_label &= ~IPV6_FLOWLABEL_MASK;
464                                 *sflp = sfl->next;
465                                 write_unlock_bh(&ip6_sk_fl_lock);
466                                 fl_release(sfl->fl);
467                                 kfree(sfl);
468                                 return 0;
469                         }
470                 }
471                 write_unlock_bh(&ip6_sk_fl_lock);
472                 return -ESRCH;
473
474         case IPV6_FL_A_RENEW:
475                 read_lock_bh(&ip6_sk_fl_lock);
476                 for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next) {
477                         if (sfl->fl->label == freq.flr_label) {
478                                 err = fl6_renew(sfl->fl, freq.flr_linger, freq.flr_expires);
479                                 read_unlock_bh(&ip6_sk_fl_lock);
480                                 return err;
481                         }
482                 }
483                 read_unlock_bh(&ip6_sk_fl_lock);
484
485                 if (freq.flr_share == IPV6_FL_S_NONE && capable(CAP_NET_ADMIN)) {
486                         fl = fl_lookup(freq.flr_label);
487                         if (fl) {
488                                 err = fl6_renew(fl, freq.flr_linger, freq.flr_expires);
489                                 fl_release(fl);
490                                 return err;
491                         }
492                 }
493                 return -ESRCH;
494
495         case IPV6_FL_A_GET:
496                 if (freq.flr_label & ~IPV6_FLOWLABEL_MASK)
497                         return -EINVAL;
498
499                 fl = fl_create(&freq, optval, optlen, &err);
500                 if (fl == NULL)
501                         return err;
502                 sfl1 = kmalloc(sizeof(*sfl1), GFP_KERNEL);
503
504                 if (freq.flr_label) {
505                         err = -EEXIST;
506                         read_lock_bh(&ip6_sk_fl_lock);
507                         for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next) {
508                                 if (sfl->fl->label == freq.flr_label) {
509                                         if (freq.flr_flags&IPV6_FL_F_EXCL) {
510                                                 read_unlock_bh(&ip6_sk_fl_lock);
511                                                 goto done;
512                                         }
513                                         fl1 = sfl->fl;
514                                         atomic_inc(&fl1->users);
515                                         break;
516                                 }
517                         }
518                         read_unlock_bh(&ip6_sk_fl_lock);
519
520                         if (fl1 == NULL)
521                                 fl1 = fl_lookup(freq.flr_label);
522                         if (fl1) {
523 recheck:
524                                 err = -EEXIST;
525                                 if (freq.flr_flags&IPV6_FL_F_EXCL)
526                                         goto release;
527                                 err = -EPERM;
528                                 if (fl1->share == IPV6_FL_S_EXCL ||
529                                     fl1->share != fl->share ||
530                                     fl1->owner != fl->owner)
531                                         goto release;
532
533                                 err = -EINVAL;
534                                 if (!ipv6_addr_equal(&fl1->dst, &fl->dst) ||
535                                     ipv6_opt_cmp(fl1->opt, fl->opt))
536                                         goto release;
537
538                                 err = -ENOMEM;
539                                 if (sfl1 == NULL)
540                                         goto release;
541                                 if (fl->linger > fl1->linger)
542                                         fl1->linger = fl->linger;
543                                 if ((long)(fl->expires - fl1->expires) > 0)
544                                         fl1->expires = fl->expires;
545                                 fl_link(np, sfl1, fl1);
546                                 fl_free(fl);
547                                 return 0;
548
549 release:
550                                 fl_release(fl1);
551                                 goto done;
552                         }
553                 }
554                 err = -ENOENT;
555                 if (!(freq.flr_flags&IPV6_FL_F_CREATE))
556                         goto done;
557
558                 err = -ENOMEM;
559                 if (sfl1 == NULL || (err = mem_check(sk)) != 0)
560                         goto done;
561
562                 fl1 = fl_intern(fl, freq.flr_label);
563                 if (fl1 != NULL)
564                         goto recheck;
565
566                 if (!freq.flr_label) {
567                         if (copy_to_user(&((struct in6_flowlabel_req __user *) optval)->flr_label,
568                                          &fl->label, sizeof(fl->label))) {
569                                 /* Intentionally ignore fault. */
570                         }
571                 }
572
573                 fl_link(np, sfl1, fl);
574                 return 0;
575
576         default:
577                 return -EINVAL;
578         }
579
580 done:
581         fl_free(fl);
582         kfree(sfl1);
583         return err;
584 }
585
586 #ifdef CONFIG_PROC_FS
587
588 struct ip6fl_iter_state {
589         int bucket;
590 };
591
592 #define ip6fl_seq_private(seq)  ((struct ip6fl_iter_state *)(seq)->private)
593
594 static struct ip6_flowlabel *ip6fl_get_first(struct seq_file *seq)
595 {
596         struct ip6_flowlabel *fl = NULL;
597         struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
598
599         for (state->bucket = 0; state->bucket <= FL_HASH_MASK; ++state->bucket) {
600                 if (fl_ht[state->bucket]) {
601                         fl = fl_ht[state->bucket];
602                         break;
603                 }
604         }
605         return fl;
606 }
607
608 static struct ip6_flowlabel *ip6fl_get_next(struct seq_file *seq, struct ip6_flowlabel *fl)
609 {
610         struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
611
612         fl = fl->next;
613         while (!fl) {
614                 if (++state->bucket <= FL_HASH_MASK)
615                         fl = fl_ht[state->bucket];
616                 else
617                         break;
618         }
619         return fl;
620 }
621
622 static struct ip6_flowlabel *ip6fl_get_idx(struct seq_file *seq, loff_t pos)
623 {
624         struct ip6_flowlabel *fl = ip6fl_get_first(seq);
625         if (fl)
626                 while (pos && (fl = ip6fl_get_next(seq, fl)) != NULL)
627                         --pos;
628         return pos ? NULL : fl;
629 }
630
631 static void *ip6fl_seq_start(struct seq_file *seq, loff_t *pos)
632         __acquires(ip6_fl_lock)
633 {
634         read_lock_bh(&ip6_fl_lock);
635         return *pos ? ip6fl_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
636 }
637
638 static void *ip6fl_seq_next(struct seq_file *seq, void *v, loff_t *pos)
639 {
640         struct ip6_flowlabel *fl;
641
642         if (v == SEQ_START_TOKEN)
643                 fl = ip6fl_get_first(seq);
644         else
645                 fl = ip6fl_get_next(seq, v);
646         ++*pos;
647         return fl;
648 }
649
650 static void ip6fl_seq_stop(struct seq_file *seq, void *v)
651         __releases(ip6_fl_lock)
652 {
653         read_unlock_bh(&ip6_fl_lock);
654 }
655
656 static int ip6fl_seq_show(struct seq_file *seq, void *v)
657 {
658         if (v == SEQ_START_TOKEN)
659                 seq_printf(seq, "%-5s %-1s %-6s %-6s %-6s %-8s %-32s %s\n",
660                            "Label", "S", "Owner", "Users", "Linger", "Expires", "Dst", "Opt");
661         else {
662                 struct ip6_flowlabel *fl = v;
663                 seq_printf(seq,
664                            "%05X %-1d %-6d %-6d %-6ld %-8ld " NIP6_SEQFMT " %-4d\n",
665                            (unsigned)ntohl(fl->label),
666                            fl->share,
667                            (unsigned)fl->owner,
668                            atomic_read(&fl->users),
669                            fl->linger/HZ,
670                            (long)(fl->expires - jiffies)/HZ,
671                            NIP6(fl->dst),
672                            fl->opt ? fl->opt->opt_nflen : 0);
673         }
674         return 0;
675 }
676
677 static const struct seq_operations ip6fl_seq_ops = {
678         .start  =       ip6fl_seq_start,
679         .next   =       ip6fl_seq_next,
680         .stop   =       ip6fl_seq_stop,
681         .show   =       ip6fl_seq_show,
682 };
683
684 static int ip6fl_seq_open(struct inode *inode, struct file *file)
685 {
686         return seq_open_private(file, &ip6fl_seq_ops,
687                         sizeof(struct ip6fl_iter_state));
688 }
689
690 static const struct file_operations ip6fl_seq_fops = {
691         .owner          =       THIS_MODULE,
692         .open           =       ip6fl_seq_open,
693         .read           =       seq_read,
694         .llseek         =       seq_lseek,
695         .release        =       seq_release_private,
696 };
697
698 static int ip6_flowlabel_proc_init(struct net *net)
699 {
700         if (!proc_net_fops_create(net, "ip6_flowlabel", S_IRUGO, &ip6fl_seq_fops))
701                 return -ENOMEM;
702         return 0;
703 }
704
705 static void ip6_flowlabel_proc_fini(struct net *net)
706 {
707         proc_net_remove(net, "ip6_flowlabel");
708 }
709 #else
710 static inline int ip6_flowlabel_proc_init(struct net *net)
711 {
712         return 0;
713 }
714 static inline void ip6_flowlabel_proc_fini(struct net *net)
715 {
716         return ;
717 }
718 #endif
719
720 int ip6_flowlabel_init(void)
721 {
722         return ip6_flowlabel_proc_init(&init_net);
723 }
724
725 void ip6_flowlabel_cleanup(void)
726 {
727         del_timer(&ip6_fl_gc_timer);
728         ip6_flowlabel_proc_fini(&init_net);
729 }