xref: /openbmc/linux/net/ipv6/ip6_flowlabel.c (revision 4fc268d24ceb9f4150777c1b5b2b8e6214e56b2b) 
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/config.h>
14 #include <linux/errno.h>
15 #include <linux/types.h>
16 #include <linux/socket.h>
17 #include <linux/net.h>
18 #include <linux/netdevice.h>
19 #include <linux/if_arp.h>
20 #include <linux/in6.h>
21 #include <linux/route.h>
22 #include <linux/proc_fs.h>
23 #include <linux/seq_file.h>
24 
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(u32 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(u32 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 int fl_intern(struct ip6_flowlabel *fl, __u32 label)
158 {
159 	fl->label = label & IPV6_FLOWLABEL_MASK;
160 
161 	write_lock_bh(&ip6_fl_lock);
162 	if (label == 0) {
163 		for (;;) {
164 			fl->label = htonl(net_random())&IPV6_FLOWLABEL_MASK;
165 			if (fl->label) {
166 				struct ip6_flowlabel *lfl;
167 				lfl = __fl_lookup(fl->label);
168 				if (lfl == NULL)
169 					break;
170 			}
171 		}
172 	}
173 
174 	fl->lastuse = jiffies;
175 	fl->next = fl_ht[FL_HASH(fl->label)];
176 	fl_ht[FL_HASH(fl->label)] = fl;
177 	atomic_inc(&fl_size);
178 	write_unlock_bh(&ip6_fl_lock);
179 	return 0;
180 }
181 
182 
183 
184 /* Socket flowlabel lists */
185 
186 struct ip6_flowlabel * fl6_sock_lookup(struct sock *sk, u32 label)
187 {
188 	struct ipv6_fl_socklist *sfl;
189 	struct ipv6_pinfo *np = inet6_sk(sk);
190 
191 	label &= IPV6_FLOWLABEL_MASK;
192 
193 	for (sfl=np->ipv6_fl_list; sfl; sfl = sfl->next) {
194 		struct ip6_flowlabel *fl = sfl->fl;
195 		if (fl->label == label) {
196 			fl->lastuse = jiffies;
197 			atomic_inc(&fl->users);
198 			return fl;
199 		}
200 	}
201 	return NULL;
202 }
203 
204 EXPORT_SYMBOL_GPL(fl6_sock_lookup);
205 
206 void fl6_free_socklist(struct sock *sk)
207 {
208 	struct ipv6_pinfo *np = inet6_sk(sk);
209 	struct ipv6_fl_socklist *sfl;
210 
211 	while ((sfl = np->ipv6_fl_list) != NULL) {
212 		np->ipv6_fl_list = sfl->next;
213 		fl_release(sfl->fl);
214 		kfree(sfl);
215 	}
216 }
217 
218 /* Service routines */
219 
220 
221 /*
222    It is the only difficult place. flowlabel enforces equal headers
223    before and including routing header, however user may supply options
224    following rthdr.
225  */
226 
227 struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions * opt_space,
228 					 struct ip6_flowlabel * fl,
229 					 struct ipv6_txoptions * fopt)
230 {
231 	struct ipv6_txoptions * fl_opt = fl->opt;
232 
233 	if (fopt == NULL || fopt->opt_flen == 0)
234 		return fl_opt;
235 
236 	if (fl_opt != NULL) {
237 		opt_space->hopopt = fl_opt->hopopt;
238 		opt_space->dst0opt = fl_opt->dst0opt;
239 		opt_space->srcrt = fl_opt->srcrt;
240 		opt_space->opt_nflen = fl_opt->opt_nflen;
241 	} else {
242 		if (fopt->opt_nflen == 0)
243 			return fopt;
244 		opt_space->hopopt = NULL;
245 		opt_space->dst0opt = NULL;
246 		opt_space->srcrt = NULL;
247 		opt_space->opt_nflen = 0;
248 	}
249 	opt_space->dst1opt = fopt->dst1opt;
250 	opt_space->opt_flen = fopt->opt_flen;
251 	return opt_space;
252 }
253 
254 static unsigned long check_linger(unsigned long ttl)
255 {
256 	if (ttl < FL_MIN_LINGER)
257 		return FL_MIN_LINGER*HZ;
258 	if (ttl > FL_MAX_LINGER && !capable(CAP_NET_ADMIN))
259 		return 0;
260 	return ttl*HZ;
261 }
262 
263 static int fl6_renew(struct ip6_flowlabel *fl, unsigned long linger, unsigned long expires)
264 {
265 	linger = check_linger(linger);
266 	if (!linger)
267 		return -EPERM;
268 	expires = check_linger(expires);
269 	if (!expires)
270 		return -EPERM;
271 	fl->lastuse = jiffies;
272 	if (time_before(fl->linger, linger))
273 		fl->linger = linger;
274 	if (time_before(expires, fl->linger))
275 		expires = fl->linger;
276 	if (time_before(fl->expires, fl->lastuse + expires))
277 		fl->expires = fl->lastuse + expires;
278 	return 0;
279 }
280 
281 static struct ip6_flowlabel *
282 fl_create(struct in6_flowlabel_req *freq, char __user *optval, int optlen, int *err_p)
283 {
284 	struct ip6_flowlabel *fl;
285 	int olen;
286 	int addr_type;
287 	int err;
288 
289 	err = -ENOMEM;
290 	fl = kmalloc(sizeof(*fl), GFP_KERNEL);
291 	if (fl == NULL)
292 		goto done;
293 	memset(fl, 0, sizeof(*fl));
294 
295 	olen = optlen - CMSG_ALIGN(sizeof(*freq));
296 	if (olen > 0) {
297 		struct msghdr msg;
298 		struct flowi flowi;
299 		int junk;
300 
301 		err = -ENOMEM;
302 		fl->opt = kmalloc(sizeof(*fl->opt) + olen, GFP_KERNEL);
303 		if (fl->opt == NULL)
304 			goto done;
305 
306 		memset(fl->opt, 0, sizeof(*fl->opt));
307 		fl->opt->tot_len = sizeof(*fl->opt) + olen;
308 		err = -EFAULT;
309 		if (copy_from_user(fl->opt+1, optval+CMSG_ALIGN(sizeof(*freq)), olen))
310 			goto done;
311 
312 		msg.msg_controllen = olen;
313 		msg.msg_control = (void*)(fl->opt+1);
314 		flowi.oif = 0;
315 
316 		err = datagram_send_ctl(&msg, &flowi, fl->opt, &junk, &junk);
317 		if (err)
318 			goto done;
319 		err = -EINVAL;
320 		if (fl->opt->opt_flen)
321 			goto done;
322 		if (fl->opt->opt_nflen == 0) {
323 			kfree(fl->opt);
324 			fl->opt = NULL;
325 		}
326 	}
327 
328 	fl->expires = jiffies;
329 	err = fl6_renew(fl, freq->flr_linger, freq->flr_expires);
330 	if (err)
331 		goto done;
332 	fl->share = freq->flr_share;
333 	addr_type = ipv6_addr_type(&freq->flr_dst);
334 	if ((addr_type&IPV6_ADDR_MAPPED)
335 	    || addr_type == IPV6_ADDR_ANY)
336 		goto done;
337 	ipv6_addr_copy(&fl->dst, &freq->flr_dst);
338 	atomic_set(&fl->users, 1);
339 	switch (fl->share) {
340 	case IPV6_FL_S_EXCL:
341 	case IPV6_FL_S_ANY:
342 		break;
343 	case IPV6_FL_S_PROCESS:
344 		fl->owner = current->pid;
345 		break;
346 	case IPV6_FL_S_USER:
347 		fl->owner = current->euid;
348 		break;
349 	default:
350 		err = -EINVAL;
351 		goto done;
352 	}
353 	return fl;
354 
355 done:
356 	fl_free(fl);
357 	*err_p = err;
358 	return NULL;
359 }
360 
361 static int mem_check(struct sock *sk)
362 {
363 	struct ipv6_pinfo *np = inet6_sk(sk);
364 	struct ipv6_fl_socklist *sfl;
365 	int room = FL_MAX_SIZE - atomic_read(&fl_size);
366 	int count = 0;
367 
368 	if (room > FL_MAX_SIZE - FL_MAX_PER_SOCK)
369 		return 0;
370 
371 	for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next)
372 		count++;
373 
374 	if (room <= 0 ||
375 	    ((count >= FL_MAX_PER_SOCK ||
376 	     (count > 0 && room < FL_MAX_SIZE/2) || room < FL_MAX_SIZE/4)
377 	     && !capable(CAP_NET_ADMIN)))
378 		return -ENOBUFS;
379 
380 	return 0;
381 }
382 
383 static int ipv6_hdr_cmp(struct ipv6_opt_hdr *h1, struct ipv6_opt_hdr *h2)
384 {
385 	if (h1 == h2)
386 		return 0;
387 	if (h1 == NULL || h2 == NULL)
388 		return 1;
389 	if (h1->hdrlen != h2->hdrlen)
390 		return 1;
391 	return memcmp(h1+1, h2+1, ((h1->hdrlen+1)<<3) - sizeof(*h1));
392 }
393 
394 static int ipv6_opt_cmp(struct ipv6_txoptions *o1, struct ipv6_txoptions *o2)
395 {
396 	if (o1 == o2)
397 		return 0;
398 	if (o1 == NULL || o2 == NULL)
399 		return 1;
400 	if (o1->opt_nflen != o2->opt_nflen)
401 		return 1;
402 	if (ipv6_hdr_cmp(o1->hopopt, o2->hopopt))
403 		return 1;
404 	if (ipv6_hdr_cmp(o1->dst0opt, o2->dst0opt))
405 		return 1;
406 	if (ipv6_hdr_cmp((struct ipv6_opt_hdr *)o1->srcrt, (struct ipv6_opt_hdr *)o2->srcrt))
407 		return 1;
408 	return 0;
409 }
410 
411 int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen)
412 {
413 	int err;
414 	struct ipv6_pinfo *np = inet6_sk(sk);
415 	struct in6_flowlabel_req freq;
416 	struct ipv6_fl_socklist *sfl1=NULL;
417 	struct ipv6_fl_socklist *sfl, **sflp;
418 	struct ip6_flowlabel *fl;
419 
420 	if (optlen < sizeof(freq))
421 		return -EINVAL;
422 
423 	if (copy_from_user(&freq, optval, sizeof(freq)))
424 		return -EFAULT;
425 
426 	switch (freq.flr_action) {
427 	case IPV6_FL_A_PUT:
428 		write_lock_bh(&ip6_sk_fl_lock);
429 		for (sflp = &np->ipv6_fl_list; (sfl=*sflp)!=NULL; sflp = &sfl->next) {
430 			if (sfl->fl->label == freq.flr_label) {
431 				if (freq.flr_label == (np->flow_label&IPV6_FLOWLABEL_MASK))
432 					np->flow_label &= ~IPV6_FLOWLABEL_MASK;
433 				*sflp = sfl->next;
434 				write_unlock_bh(&ip6_sk_fl_lock);
435 				fl_release(sfl->fl);
436 				kfree(sfl);
437 				return 0;
438 			}
439 		}
440 		write_unlock_bh(&ip6_sk_fl_lock);
441 		return -ESRCH;
442 
443 	case IPV6_FL_A_RENEW:
444 		read_lock_bh(&ip6_sk_fl_lock);
445 		for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next) {
446 			if (sfl->fl->label == freq.flr_label) {
447 				err = fl6_renew(sfl->fl, freq.flr_linger, freq.flr_expires);
448 				read_unlock_bh(&ip6_sk_fl_lock);
449 				return err;
450 			}
451 		}
452 		read_unlock_bh(&ip6_sk_fl_lock);
453 
454 		if (freq.flr_share == IPV6_FL_S_NONE && capable(CAP_NET_ADMIN)) {
455 			fl = fl_lookup(freq.flr_label);
456 			if (fl) {
457 				err = fl6_renew(fl, freq.flr_linger, freq.flr_expires);
458 				fl_release(fl);
459 				return err;
460 			}
461 		}
462 		return -ESRCH;
463 
464 	case IPV6_FL_A_GET:
465 		if (freq.flr_label & ~IPV6_FLOWLABEL_MASK)
466 			return -EINVAL;
467 
468 		fl = fl_create(&freq, optval, optlen, &err);
469 		if (fl == NULL)
470 			return err;
471 		sfl1 = kmalloc(sizeof(*sfl1), GFP_KERNEL);
472 
473 		if (freq.flr_label) {
474 			struct ip6_flowlabel *fl1 = NULL;
475 
476 			err = -EEXIST;
477 			read_lock_bh(&ip6_sk_fl_lock);
478 			for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next) {
479 				if (sfl->fl->label == freq.flr_label) {
480 					if (freq.flr_flags&IPV6_FL_F_EXCL) {
481 						read_unlock_bh(&ip6_sk_fl_lock);
482 						goto done;
483 					}
484 					fl1 = sfl->fl;
485 					atomic_inc(&fl1->users);
486 					break;
487 				}
488 			}
489 			read_unlock_bh(&ip6_sk_fl_lock);
490 
491 			if (fl1 == NULL)
492 				fl1 = fl_lookup(freq.flr_label);
493 			if (fl1) {
494 				err = -EEXIST;
495 				if (freq.flr_flags&IPV6_FL_F_EXCL)
496 					goto release;
497 				err = -EPERM;
498 				if (fl1->share == IPV6_FL_S_EXCL ||
499 				    fl1->share != fl->share ||
500 				    fl1->owner != fl->owner)
501 					goto release;
502 
503 				err = -EINVAL;
504 				if (!ipv6_addr_equal(&fl1->dst, &fl->dst) ||
505 				    ipv6_opt_cmp(fl1->opt, fl->opt))
506 					goto release;
507 
508 				err = -ENOMEM;
509 				if (sfl1 == NULL)
510 					goto release;
511 				if (fl->linger > fl1->linger)
512 					fl1->linger = fl->linger;
513 				if ((long)(fl->expires - fl1->expires) > 0)
514 					fl1->expires = fl->expires;
515 				write_lock_bh(&ip6_sk_fl_lock);
516 				sfl1->fl = fl1;
517 				sfl1->next = np->ipv6_fl_list;
518 				np->ipv6_fl_list = sfl1;
519 				write_unlock_bh(&ip6_sk_fl_lock);
520 				fl_free(fl);
521 				return 0;
522 
523 release:
524 				fl_release(fl1);
525 				goto done;
526 			}
527 		}
528 		err = -ENOENT;
529 		if (!(freq.flr_flags&IPV6_FL_F_CREATE))
530 			goto done;
531 
532 		err = -ENOMEM;
533 		if (sfl1 == NULL || (err = mem_check(sk)) != 0)
534 			goto done;
535 
536 		err = fl_intern(fl, freq.flr_label);
537 		if (err)
538 			goto done;
539 
540 		if (!freq.flr_label) {
541 			if (copy_to_user(&((struct in6_flowlabel_req __user *) optval)->flr_label,
542 					 &fl->label, sizeof(fl->label))) {
543 				/* Intentionally ignore fault. */
544 			}
545 		}
546 
547 		sfl1->fl = fl;
548 		sfl1->next = np->ipv6_fl_list;
549 		np->ipv6_fl_list = sfl1;
550 		return 0;
551 
552 	default:
553 		return -EINVAL;
554 	}
555 
556 done:
557 	fl_free(fl);
558 	kfree(sfl1);
559 	return err;
560 }
561 
562 #ifdef CONFIG_PROC_FS
563 
564 struct ip6fl_iter_state {
565 	int bucket;
566 };
567 
568 #define ip6fl_seq_private(seq)	((struct ip6fl_iter_state *)(seq)->private)
569 
570 static struct ip6_flowlabel *ip6fl_get_first(struct seq_file *seq)
571 {
572 	struct ip6_flowlabel *fl = NULL;
573 	struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
574 
575 	for (state->bucket = 0; state->bucket <= FL_HASH_MASK; ++state->bucket) {
576 		if (fl_ht[state->bucket]) {
577 			fl = fl_ht[state->bucket];
578 			break;
579 		}
580 	}
581 	return fl;
582 }
583 
584 static struct ip6_flowlabel *ip6fl_get_next(struct seq_file *seq, struct ip6_flowlabel *fl)
585 {
586 	struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
587 
588 	fl = fl->next;
589 	while (!fl) {
590 		if (++state->bucket <= FL_HASH_MASK)
591 			fl = fl_ht[state->bucket];
592 	}
593 	return fl;
594 }
595 
596 static struct ip6_flowlabel *ip6fl_get_idx(struct seq_file *seq, loff_t pos)
597 {
598 	struct ip6_flowlabel *fl = ip6fl_get_first(seq);
599 	if (fl)
600 		while (pos && (fl = ip6fl_get_next(seq, fl)) != NULL)
601 			--pos;
602 	return pos ? NULL : fl;
603 }
604 
605 static void *ip6fl_seq_start(struct seq_file *seq, loff_t *pos)
606 {
607 	read_lock_bh(&ip6_fl_lock);
608 	return *pos ? ip6fl_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
609 }
610 
611 static void *ip6fl_seq_next(struct seq_file *seq, void *v, loff_t *pos)
612 {
613 	struct ip6_flowlabel *fl;
614 
615 	if (v == SEQ_START_TOKEN)
616 		fl = ip6fl_get_first(seq);
617 	else
618 		fl = ip6fl_get_next(seq, v);
619 	++*pos;
620 	return fl;
621 }
622 
623 static void ip6fl_seq_stop(struct seq_file *seq, void *v)
624 {
625 	read_unlock_bh(&ip6_fl_lock);
626 }
627 
628 static void ip6fl_fl_seq_show(struct seq_file *seq, struct ip6_flowlabel *fl)
629 {
630 	while(fl) {
631 		seq_printf(seq,
632 			   "%05X %-1d %-6d %-6d %-6ld %-8ld "
633 			   "%02x%02x%02x%02x%02x%02x%02x%02x "
634 			   "%-4d\n",
635 			   (unsigned)ntohl(fl->label),
636 			   fl->share,
637 			   (unsigned)fl->owner,
638 			   atomic_read(&fl->users),
639 			   fl->linger/HZ,
640 			   (long)(fl->expires - jiffies)/HZ,
641 			   NIP6(fl->dst),
642 			   fl->opt ? fl->opt->opt_nflen : 0);
643 		fl = fl->next;
644 	}
645 }
646 
647 static int ip6fl_seq_show(struct seq_file *seq, void *v)
648 {
649 	if (v == SEQ_START_TOKEN)
650 		seq_puts(seq, "Label S Owner  Users  Linger Expires  "
651 			      "Dst                              Opt\n");
652 	else
653 		ip6fl_fl_seq_show(seq, v);
654 	return 0;
655 }
656 
657 static struct seq_operations ip6fl_seq_ops = {
658 	.start	=	ip6fl_seq_start,
659 	.next	=	ip6fl_seq_next,
660 	.stop	=	ip6fl_seq_stop,
661 	.show	=	ip6fl_seq_show,
662 };
663 
664 static int ip6fl_seq_open(struct inode *inode, struct file *file)
665 {
666 	struct seq_file *seq;
667 	int rc = -ENOMEM;
668 	struct ip6fl_iter_state *s = kmalloc(sizeof(*s), GFP_KERNEL);
669 
670 	if (!s)
671 		goto out;
672 
673 	rc = seq_open(file, &ip6fl_seq_ops);
674 	if (rc)
675 		goto out_kfree;
676 
677 	seq = file->private_data;
678 	seq->private = s;
679 	memset(s, 0, sizeof(*s));
680 out:
681 	return rc;
682 out_kfree:
683 	kfree(s);
684 	goto out;
685 }
686 
687 static struct file_operations ip6fl_seq_fops = {
688 	.owner		=	THIS_MODULE,
689 	.open		=	ip6fl_seq_open,
690 	.read		=	seq_read,
691 	.llseek		=	seq_lseek,
692 	.release	=	seq_release_private,
693 };
694 #endif
695 
696 
697 void ip6_flowlabel_init(void)
698 {
699 #ifdef CONFIG_PROC_FS
700 	proc_net_fops_create("ip6_flowlabel", S_IRUGO, &ip6fl_seq_fops);
701 #endif
702 }
703 
704 void ip6_flowlabel_cleanup(void)
705 {
706 	del_timer(&ip6_fl_gc_timer);
707 #ifdef CONFIG_PROC_FS
708 	proc_net_remove("ip6_flowlabel");
709 #endif
710 }
711