xref: /openbmc/linux/net/ipv6/ip6_flowlabel.c (revision 643d1f7f) 
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 }
730