ip6_flowlabel.c

  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 *	ip6_flowlabel.c		IPv6 flowlabel manager.
  4 *
  5 *	Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
  6 */
  7
  8#include <linux/capability.h>
  9#include <linux/errno.h>
 10#include <linux/types.h>
 11#include <linux/socket.h>
 12#include <linux/net.h>
 13#include <linux/netdevice.h>
 14#include <linux/in6.h>
 15#include <linux/proc_fs.h>
 16#include <linux/seq_file.h>
 17#include <linux/slab.h>
 18#include <linux/export.h>
 19#include <linux/pid_namespace.h>
 20#include <linux/jump_label_ratelimit.h>
 21
 22#include <net/net_namespace.h>
 23#include <net/sock.h>
 24
 25#include <net/ipv6.h>
 26#include <net/rawv6.h>
 27#include <net/transp_v6.h>
 28
 29#include <linux/uaccess.h>
 30
 31#define FL_MIN_LINGER	6	/* Minimal linger. It is set to 6sec specified
 32				   in old IPv6 RFC. Well, it was reasonable value.
 33				 */
 34#define FL_MAX_LINGER	150	/* Maximal linger timeout */
 35
 36/* FL hash table */
 37
 38#define FL_MAX_PER_SOCK	32
 39#define FL_MAX_SIZE	4096
 40#define FL_HASH_MASK	255
 41#define FL_HASH(l)	(ntohl(l)&FL_HASH_MASK)
 42
 43static atomic_t fl_size = ATOMIC_INIT(0);
 44static struct ip6_flowlabel __rcu *fl_ht[FL_HASH_MASK+1];
 45
 46static void ip6_fl_gc(struct timer_list *unused);
 47static DEFINE_TIMER(ip6_fl_gc_timer, ip6_fl_gc);
 48
 49/* FL hash table lock: it protects only of GC */
 50
 51static DEFINE_SPINLOCK(ip6_fl_lock);
 52
 53/* Big socket sock */
 54
 55static DEFINE_SPINLOCK(ip6_sk_fl_lock);
 56
 57DEFINE_STATIC_KEY_DEFERRED_FALSE(ipv6_flowlabel_exclusive, HZ);
 58EXPORT_SYMBOL(ipv6_flowlabel_exclusive);
 59
 60#define for_each_fl_rcu(hash, fl)				\
 61	for (fl = rcu_dereference(fl_ht[(hash)]);		\
 62	     fl != NULL;					\
 63	     fl = rcu_dereference(fl->next))
 64#define for_each_fl_continue_rcu(fl)				\
 65	for (fl = rcu_dereference(fl->next);			\
 66	     fl != NULL;					\
 67	     fl = rcu_dereference(fl->next))
 68
 69#define for_each_sk_fl_rcu(sk, sfl)				\
 70	for (sfl = rcu_dereference(inet_sk(sk)->ipv6_fl_list);	\
 71	     sfl != NULL;					\
 72	     sfl = rcu_dereference(sfl->next))
 73
 74static inline struct ip6_flowlabel *__fl_lookup(struct net *net, __be32 label)
 75{
 76	struct ip6_flowlabel *fl;
 77
 78	for_each_fl_rcu(FL_HASH(label), fl) {
 79		if (fl->label == label && net_eq(fl->fl_net, net))
 80			return fl;
 81	}
 82	return NULL;
 83}
 84
 85static struct ip6_flowlabel *fl_lookup(struct net *net, __be32 label)
 86{
 87	struct ip6_flowlabel *fl;
 88
 89	rcu_read_lock();
 90	fl = __fl_lookup(net, label);
 91	if (fl && !atomic_inc_not_zero(&fl->users))
 92		fl = NULL;
 93	rcu_read_unlock();
 94	return fl;
 95}
 96
 97static bool fl_shared_exclusive(struct ip6_flowlabel *fl)
 98{
 99	return fl->share == IPV6_FL_S_EXCL ||
100	       fl->share == IPV6_FL_S_PROCESS ||
101	       fl->share == IPV6_FL_S_USER;
102}
103
104static void fl_free_rcu(struct rcu_head *head)
105{
106	struct ip6_flowlabel *fl = container_of(head, struct ip6_flowlabel, rcu);
107
108	if (fl->share == IPV6_FL_S_PROCESS)
109		put_pid(fl->owner.pid);
110	kfree(fl->opt);
111	kfree(fl);
112}
113
114
115static void fl_free(struct ip6_flowlabel *fl)
116{
117	if (!fl)
118		return;
119
120	if (fl_shared_exclusive(fl) || fl->opt)
121		static_branch_slow_dec_deferred(&ipv6_flowlabel_exclusive);
122
123	call_rcu(&fl->rcu, fl_free_rcu);
124}
125
126static void fl_release(struct ip6_flowlabel *fl)
127{
128	spin_lock_bh(&ip6_fl_lock);
129
130	fl->lastuse = jiffies;
131	if (atomic_dec_and_test(&fl->users)) {
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 (!timer_pending(&ip6_fl_gc_timer) ||
137		    time_after(ip6_fl_gc_timer.expires, ttd))
138			mod_timer(&ip6_fl_gc_timer, ttd);
139	}
140	spin_unlock_bh(&ip6_fl_lock);
141}
142
143static void ip6_fl_gc(struct timer_list *unused)
144{
145	int i;
146	unsigned long now = jiffies;
147	unsigned long sched = 0;
148
149	spin_lock(&ip6_fl_lock);
150
151	for (i = 0; i <= FL_HASH_MASK; i++) {
152		struct ip6_flowlabel *fl;
153		struct ip6_flowlabel __rcu **flp;
154
155		flp = &fl_ht[i];
156		while ((fl = rcu_dereference_protected(*flp,
157						       lockdep_is_held(&ip6_fl_lock))) != NULL) {
158			if (atomic_read(&fl->users) == 0) {
159				unsigned long ttd = fl->lastuse + fl->linger;
160				if (time_after(ttd, fl->expires))
161					fl->expires = ttd;
162				ttd = fl->expires;
163				if (time_after_eq(now, ttd)) {
164					*flp = fl->next;
165					fl_free(fl);
166					atomic_dec(&fl_size);
167					continue;
168				}
169				if (!sched || time_before(ttd, sched))
170					sched = ttd;
171			}
172			flp = &fl->next;
173		}
174	}
175	if (!sched && atomic_read(&fl_size))
176		sched = now + FL_MAX_LINGER;
177	if (sched) {
178		mod_timer(&ip6_fl_gc_timer, sched);
179	}
180	spin_unlock(&ip6_fl_lock);
181}
182
183static void __net_exit ip6_fl_purge(struct net *net)
184{
185	int i;
186
187	spin_lock_bh(&ip6_fl_lock);
188	for (i = 0; i <= FL_HASH_MASK; i++) {
189		struct ip6_flowlabel *fl;
190		struct ip6_flowlabel __rcu **flp;
191
192		flp = &fl_ht[i];
193		while ((fl = rcu_dereference_protected(*flp,
194						       lockdep_is_held(&ip6_fl_lock))) != NULL) {
195			if (net_eq(fl->fl_net, net) &&
196			    atomic_read(&fl->users) == 0) {
197				*flp = fl->next;
198				fl_free(fl);
199				atomic_dec(&fl_size);
200				continue;
201			}
202			flp = &fl->next;
203		}
204	}
205	spin_unlock_bh(&ip6_fl_lock);
206}
207
208static struct ip6_flowlabel *fl_intern(struct net *net,
209				       struct ip6_flowlabel *fl, __be32 label)
210{
211	struct ip6_flowlabel *lfl;
212
213	fl->label = label & IPV6_FLOWLABEL_MASK;
214
215	rcu_read_lock();
216	spin_lock_bh(&ip6_fl_lock);
217	if (label == 0) {
218		for (;;) {
219			fl->label = htonl(get_random_u32())&IPV6_FLOWLABEL_MASK;
220			if (fl->label) {
221				lfl = __fl_lookup(net, fl->label);
222				if (!lfl)
223					break;
224			}
225		}
226	} else {
227		/*
228		 * we dropper the ip6_fl_lock, so this entry could reappear
229		 * and we need to recheck with it.
230		 *
231		 * OTOH no need to search the active socket first, like it is
232		 * done in ipv6_flowlabel_opt - sock is locked, so new entry
233		 * with the same label can only appear on another sock
234		 */
235		lfl = __fl_lookup(net, fl->label);
236		if (lfl) {
237			atomic_inc(&lfl->users);
238			spin_unlock_bh(&ip6_fl_lock);
239			rcu_read_unlock();
240			return lfl;
241		}
242	}
243
244	fl->lastuse = jiffies;
245	fl->next = fl_ht[FL_HASH(fl->label)];
246	rcu_assign_pointer(fl_ht[FL_HASH(fl->label)], fl);
247	atomic_inc(&fl_size);
248	spin_unlock_bh(&ip6_fl_lock);
249	rcu_read_unlock();
250	return NULL;
251}
252
253
254
255/* Socket flowlabel lists */
256
257struct ip6_flowlabel *__fl6_sock_lookup(struct sock *sk, __be32 label)
258{
259	struct ipv6_fl_socklist *sfl;
260
261	label &= IPV6_FLOWLABEL_MASK;
262
263	rcu_read_lock();
264	for_each_sk_fl_rcu(sk, sfl) {
265		struct ip6_flowlabel *fl = sfl->fl;
266
267		if (fl->label == label && atomic_inc_not_zero(&fl->users)) {
268			fl->lastuse = jiffies;
269			rcu_read_unlock();
270			return fl;
271		}
272	}
273	rcu_read_unlock();
274	return NULL;
275}
276EXPORT_SYMBOL_GPL(__fl6_sock_lookup);
277
278void fl6_free_socklist(struct sock *sk)
279{
280	struct inet_sock *inet = inet_sk(sk);
281	struct ipv6_fl_socklist *sfl;
282
283	if (!rcu_access_pointer(inet->ipv6_fl_list))
284		return;
285
286	spin_lock_bh(&ip6_sk_fl_lock);
287	while ((sfl = rcu_dereference_protected(inet->ipv6_fl_list,
288						lockdep_is_held(&ip6_sk_fl_lock))) != NULL) {
289		inet->ipv6_fl_list = sfl->next;
290		spin_unlock_bh(&ip6_sk_fl_lock);
291
292		fl_release(sfl->fl);
293		kfree_rcu(sfl, rcu);
294
295		spin_lock_bh(&ip6_sk_fl_lock);
296	}
297	spin_unlock_bh(&ip6_sk_fl_lock);
298}
299
300/* Service routines */
301
302
303/*
304   It is the only difficult place. flowlabel enforces equal headers
305   before and including routing header, however user may supply options
306   following rthdr.
307 */
308
309struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions *opt_space,
310					 struct ip6_flowlabel *fl,
311					 struct ipv6_txoptions *fopt)
312{
313	struct ipv6_txoptions *fl_opt = fl->opt;
314
315	if (!fopt || fopt->opt_flen == 0)
316		return fl_opt;
317
318	if (fl_opt) {
319		opt_space->hopopt = fl_opt->hopopt;
320		opt_space->dst0opt = fl_opt->dst0opt;
321		opt_space->srcrt = fl_opt->srcrt;
322		opt_space->opt_nflen = fl_opt->opt_nflen;
323	} else {
324		if (fopt->opt_nflen == 0)
325			return fopt;
326		opt_space->hopopt = NULL;
327		opt_space->dst0opt = NULL;
328		opt_space->srcrt = NULL;
329		opt_space->opt_nflen = 0;
330	}
331	opt_space->dst1opt = fopt->dst1opt;
332	opt_space->opt_flen = fopt->opt_flen;
333	opt_space->tot_len = fopt->tot_len;
334	return opt_space;
335}
336EXPORT_SYMBOL_GPL(fl6_merge_options);
337
338static unsigned long check_linger(unsigned long ttl)
339{
340	if (ttl < FL_MIN_LINGER)
341		return FL_MIN_LINGER*HZ;
342	if (ttl > FL_MAX_LINGER && !capable(CAP_NET_ADMIN))
343		return 0;
344	return ttl*HZ;
345}
346
347static int fl6_renew(struct ip6_flowlabel *fl, unsigned long linger, unsigned long expires)
348{
349	linger = check_linger(linger);
350	if (!linger)
351		return -EPERM;
352	expires = check_linger(expires);
353	if (!expires)
354		return -EPERM;
355
356	spin_lock_bh(&ip6_fl_lock);
357	fl->lastuse = jiffies;
358	if (time_before(fl->linger, linger))
359		fl->linger = linger;
360	if (time_before(expires, fl->linger))
361		expires = fl->linger;
362	if (time_before(fl->expires, fl->lastuse + expires))
363		fl->expires = fl->lastuse + expires;
364	spin_unlock_bh(&ip6_fl_lock);
365
366	return 0;
367}
368
369static struct ip6_flowlabel *
370fl_create(struct net *net, struct sock *sk, struct in6_flowlabel_req *freq,
371	  sockptr_t optval, int optlen, int *err_p)
372{
373	struct ip6_flowlabel *fl = NULL;
374	int olen;
375	int addr_type;
376	int err;
377
378	olen = optlen - CMSG_ALIGN(sizeof(*freq));
379	err = -EINVAL;
380	if (olen > 64 * 1024)
381		goto done;
382
383	err = -ENOMEM;
384	fl = kzalloc(sizeof(*fl), GFP_KERNEL);
385	if (!fl)
386		goto done;
387
388	if (olen > 0) {
389		struct msghdr msg;
390		struct flowi6 flowi6;
391		struct ipcm6_cookie ipc6;
392
393		err = -ENOMEM;
394		fl->opt = kmalloc(sizeof(*fl->opt) + olen, GFP_KERNEL);
395		if (!fl->opt)
396			goto done;
397
398		memset(fl->opt, 0, sizeof(*fl->opt));
399		fl->opt->tot_len = sizeof(*fl->opt) + olen;
400		err = -EFAULT;
401		if (copy_from_sockptr_offset(fl->opt + 1, optval,
402				CMSG_ALIGN(sizeof(*freq)), olen))
403			goto done;
404
405		msg.msg_controllen = olen;
406		msg.msg_control = (void *)(fl->opt+1);
407		memset(&flowi6, 0, sizeof(flowi6));
408
409		ipc6.opt = fl->opt;
410		err = ip6_datagram_send_ctl(net, sk, &msg, &flowi6, &ipc6);
411		if (err)
412			goto done;
413		err = -EINVAL;
414		if (fl->opt->opt_flen)
415			goto done;
416		if (fl->opt->opt_nflen == 0) {
417			kfree(fl->opt);
418			fl->opt = NULL;
419		}
420	}
421
422	fl->fl_net = net;
423	fl->expires = jiffies;
424	err = fl6_renew(fl, freq->flr_linger, freq->flr_expires);
425	if (err)
426		goto done;
427	fl->share = freq->flr_share;
428	addr_type = ipv6_addr_type(&freq->flr_dst);
429	if ((addr_type & IPV6_ADDR_MAPPED) ||
430	    addr_type == IPV6_ADDR_ANY) {
431		err = -EINVAL;
432		goto done;
433	}
434	fl->dst = freq->flr_dst;
435	atomic_set(&fl->users, 1);
436	switch (fl->share) {
437	case IPV6_FL_S_EXCL:
438	case IPV6_FL_S_ANY:
439		break;
440	case IPV6_FL_S_PROCESS:
441		fl->owner.pid = get_task_pid(current, PIDTYPE_PID);
442		break;
443	case IPV6_FL_S_USER:
444		fl->owner.uid = current_euid();
445		break;
446	default:
447		err = -EINVAL;
448		goto done;
449	}
450	if (fl_shared_exclusive(fl) || fl->opt) {
451		WRITE_ONCE(sock_net(sk)->ipv6.flowlabel_has_excl, 1);
452		static_branch_deferred_inc(&ipv6_flowlabel_exclusive);
453	}
454	return fl;
455
456done:
457	if (fl) {
458		kfree(fl->opt);
459		kfree(fl);
460	}
461	*err_p = err;
462	return NULL;
463}
464
465static int mem_check(struct sock *sk)
466{
467	int room = FL_MAX_SIZE - atomic_read(&fl_size);
468	struct ipv6_fl_socklist *sfl;
469	int count = 0;
470
471	if (room > FL_MAX_SIZE - FL_MAX_PER_SOCK)
472		return 0;
473
474	rcu_read_lock();
475	for_each_sk_fl_rcu(sk, sfl)
476		count++;
477	rcu_read_unlock();
478
479	if (room <= 0 ||
480	    ((count >= FL_MAX_PER_SOCK ||
481	      (count > 0 && room < FL_MAX_SIZE/2) || room < FL_MAX_SIZE/4) &&
482	     !capable(CAP_NET_ADMIN)))
483		return -ENOBUFS;
484
485	return 0;
486}
487
488static inline void fl_link(struct sock *sk, struct ipv6_fl_socklist *sfl,
489			   struct ip6_flowlabel *fl)
490{
491	struct inet_sock *inet = inet_sk(sk);
492
493	spin_lock_bh(&ip6_sk_fl_lock);
494	sfl->fl = fl;
495	sfl->next = inet->ipv6_fl_list;
496	rcu_assign_pointer(inet->ipv6_fl_list, sfl);
497	spin_unlock_bh(&ip6_sk_fl_lock);
498}
499
500int ipv6_flowlabel_opt_get(struct sock *sk, struct in6_flowlabel_req *freq,
501			   int flags)
502{
503	struct ipv6_pinfo *np = inet6_sk(sk);
504	struct ipv6_fl_socklist *sfl;
505
506	if (flags & IPV6_FL_F_REMOTE) {
507		freq->flr_label = np->rcv_flowinfo & IPV6_FLOWLABEL_MASK;
508		return 0;
509	}
510
511	if (inet6_test_bit(REPFLOW, sk)) {
512		freq->flr_label = np->flow_label;
513		return 0;
514	}
515
516	rcu_read_lock();
517
518	for_each_sk_fl_rcu(sk, sfl) {
519		if (sfl->fl->label == (np->flow_label & IPV6_FLOWLABEL_MASK)) {
520			spin_lock_bh(&ip6_fl_lock);
521			freq->flr_label = sfl->fl->label;
522			freq->flr_dst = sfl->fl->dst;
523			freq->flr_share = sfl->fl->share;
524			freq->flr_expires = (sfl->fl->expires - jiffies) / HZ;
525			freq->flr_linger = sfl->fl->linger / HZ;
526
527			spin_unlock_bh(&ip6_fl_lock);
528			rcu_read_unlock();
529			return 0;
530		}
531	}
532	rcu_read_unlock();
533
534	return -ENOENT;
535}
536
537#define socklist_dereference(__sflp) \
538	rcu_dereference_protected(__sflp, lockdep_is_held(&ip6_sk_fl_lock))
539
540static int ipv6_flowlabel_put(struct sock *sk, struct in6_flowlabel_req *freq)
541{
542	struct ipv6_pinfo *np = inet6_sk(sk);
543	struct ipv6_fl_socklist __rcu **sflp;
544	struct ipv6_fl_socklist *sfl;
545
546	if (freq->flr_flags & IPV6_FL_F_REFLECT) {
547		if (sk->sk_protocol != IPPROTO_TCP)
548			return -ENOPROTOOPT;
549		if (!inet6_test_bit(REPFLOW, sk))
550			return -ESRCH;
551		np->flow_label = 0;
552		inet6_clear_bit(REPFLOW, sk);
553		return 0;
554	}
555
556	spin_lock_bh(&ip6_sk_fl_lock);
557	for (sflp = &inet_sk(sk)->ipv6_fl_list;
558	     (sfl = socklist_dereference(*sflp)) != NULL;
559	     sflp = &sfl->next) {
560		if (sfl->fl->label == freq->flr_label)
561			goto found;
562	}
563	spin_unlock_bh(&ip6_sk_fl_lock);
564	return -ESRCH;
565found:
566	if (freq->flr_label == (np->flow_label & IPV6_FLOWLABEL_MASK))
567		np->flow_label &= ~IPV6_FLOWLABEL_MASK;
568	*sflp = sfl->next;
569	spin_unlock_bh(&ip6_sk_fl_lock);
570	fl_release(sfl->fl);
571	kfree_rcu(sfl, rcu);
572	return 0;
573}
574
575static int ipv6_flowlabel_renew(struct sock *sk, struct in6_flowlabel_req *freq)
576{
577	struct net *net = sock_net(sk);
578	struct ipv6_fl_socklist *sfl;
579	int err;
580
581	rcu_read_lock();
582	for_each_sk_fl_rcu(sk, sfl) {
583		if (sfl->fl->label == freq->flr_label) {
584			err = fl6_renew(sfl->fl, freq->flr_linger,
585					freq->flr_expires);
586			rcu_read_unlock();
587			return err;
588		}
589	}
590	rcu_read_unlock();
591
592	if (freq->flr_share == IPV6_FL_S_NONE &&
593	    ns_capable(net->user_ns, CAP_NET_ADMIN)) {
594		struct ip6_flowlabel *fl = fl_lookup(net, freq->flr_label);
595
596		if (fl) {
597			err = fl6_renew(fl, freq->flr_linger,
598					freq->flr_expires);
599			fl_release(fl);
600			return err;
601		}
602	}
603	return -ESRCH;
604}
605
606static int ipv6_flowlabel_get(struct sock *sk, struct in6_flowlabel_req *freq,
607		sockptr_t optval, int optlen)
608{
609	struct ipv6_fl_socklist *sfl, *sfl1 = NULL;
610	struct ip6_flowlabel *fl, *fl1 = NULL;
611	struct net *net = sock_net(sk);
612	int err;
613
614	if (freq->flr_flags & IPV6_FL_F_REFLECT) {
615		if (net->ipv6.sysctl.flowlabel_consistency) {
616			net_info_ratelimited("Can not set IPV6_FL_F_REFLECT if flowlabel_consistency sysctl is enable\n");
617			return -EPERM;
618		}
619
620		if (sk->sk_protocol != IPPROTO_TCP)
621			return -ENOPROTOOPT;
622		inet6_set_bit(REPFLOW, sk);
623		return 0;
624	}
625
626	if (freq->flr_label & ~IPV6_FLOWLABEL_MASK)
627		return -EINVAL;
628	if (net->ipv6.sysctl.flowlabel_state_ranges &&
629	    (freq->flr_label & IPV6_FLOWLABEL_STATELESS_FLAG))
630		return -ERANGE;
631
632	fl = fl_create(net, sk, freq, optval, optlen, &err);
633	if (!fl)
634		return err;
635
636	sfl1 = kmalloc(sizeof(*sfl1), GFP_KERNEL);
637
638	if (freq->flr_label) {
639		err = -EEXIST;
640		rcu_read_lock();
641		for_each_sk_fl_rcu(sk, sfl) {
642			if (sfl->fl->label == freq->flr_label) {
643				if (freq->flr_flags & IPV6_FL_F_EXCL) {
644					rcu_read_unlock();
645					goto done;
646				}
647				fl1 = sfl->fl;
648				if (!atomic_inc_not_zero(&fl1->users))
649					fl1 = NULL;
650				break;
651			}
652		}
653		rcu_read_unlock();
654
655		if (!fl1)
656			fl1 = fl_lookup(net, freq->flr_label);
657		if (fl1) {
658recheck:
659			err = -EEXIST;
660			if (freq->flr_flags&IPV6_FL_F_EXCL)
661				goto release;
662			err = -EPERM;
663			if (fl1->share == IPV6_FL_S_EXCL ||
664			    fl1->share != fl->share ||
665			    ((fl1->share == IPV6_FL_S_PROCESS) &&
666			     (fl1->owner.pid != fl->owner.pid)) ||
667			    ((fl1->share == IPV6_FL_S_USER) &&
668			     !uid_eq(fl1->owner.uid, fl->owner.uid)))
669				goto release;
670
671			err = -ENOMEM;
672			if (!sfl1)
673				goto release;
674			if (fl->linger > fl1->linger)
675				fl1->linger = fl->linger;
676			if ((long)(fl->expires - fl1->expires) > 0)
677				fl1->expires = fl->expires;
678			fl_link(sk, sfl1, fl1);
679			fl_free(fl);
680			return 0;
681
682release:
683			fl_release(fl1);
684			goto done;
685		}
686	}
687	err = -ENOENT;
688	if (!(freq->flr_flags & IPV6_FL_F_CREATE))
689		goto done;
690
691	err = -ENOMEM;
692	if (!sfl1)
693		goto done;
694
695	err = mem_check(sk);
696	if (err != 0)
697		goto done;
698
699	fl1 = fl_intern(net, fl, freq->flr_label);
700	if (fl1)
701		goto recheck;
702
703	if (!freq->flr_label) {
704		size_t offset = offsetof(struct in6_flowlabel_req, flr_label);
705
706		if (copy_to_sockptr_offset(optval, offset, &fl->label,
707				sizeof(fl->label))) {
708			/* Intentionally ignore fault. */
709		}
710	}
711
712	fl_link(sk, sfl1, fl);
713	return 0;
714done:
715	fl_free(fl);
716	kfree(sfl1);
717	return err;
718}
719
720int ipv6_flowlabel_opt(struct sock *sk, sockptr_t optval, int optlen)
721{
722	struct in6_flowlabel_req freq;
723
724	if (optlen < sizeof(freq))
725		return -EINVAL;
726	if (copy_from_sockptr(&freq, optval, sizeof(freq)))
727		return -EFAULT;
728
729	switch (freq.flr_action) {
730	case IPV6_FL_A_PUT:
731		return ipv6_flowlabel_put(sk, &freq);
732	case IPV6_FL_A_RENEW:
733		return ipv6_flowlabel_renew(sk, &freq);
734	case IPV6_FL_A_GET:
735		return ipv6_flowlabel_get(sk, &freq, optval, optlen);
736	default:
737		return -EINVAL;
738	}
739}
740
741#ifdef CONFIG_PROC_FS
742
743struct ip6fl_iter_state {
744	struct seq_net_private p;
745	struct pid_namespace *pid_ns;
746	int bucket;
747};
748
749#define ip6fl_seq_private(seq)	((struct ip6fl_iter_state *)(seq)->private)
750
751static struct ip6_flowlabel *ip6fl_get_first(struct seq_file *seq)
752{
753	struct ip6_flowlabel *fl = NULL;
754	struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
755	struct net *net = seq_file_net(seq);
756
757	for (state->bucket = 0; state->bucket <= FL_HASH_MASK; ++state->bucket) {
758		for_each_fl_rcu(state->bucket, fl) {
759			if (net_eq(fl->fl_net, net))
760				goto out;
761		}
762	}
763	fl = NULL;
764out:
765	return fl;
766}
767
768static struct ip6_flowlabel *ip6fl_get_next(struct seq_file *seq, struct ip6_flowlabel *fl)
769{
770	struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
771	struct net *net = seq_file_net(seq);
772
773	for_each_fl_continue_rcu(fl) {
774		if (net_eq(fl->fl_net, net))
775			goto out;
776	}
777
778try_again:
779	if (++state->bucket <= FL_HASH_MASK) {
780		for_each_fl_rcu(state->bucket, fl) {
781			if (net_eq(fl->fl_net, net))
782				goto out;
783		}
784		goto try_again;
785	}
786	fl = NULL;
787
788out:
789	return fl;
790}
791
792static struct ip6_flowlabel *ip6fl_get_idx(struct seq_file *seq, loff_t pos)
793{
794	struct ip6_flowlabel *fl = ip6fl_get_first(seq);
795	if (fl)
796		while (pos && (fl = ip6fl_get_next(seq, fl)) != NULL)
797			--pos;
798	return pos ? NULL : fl;
799}
800
801static void *ip6fl_seq_start(struct seq_file *seq, loff_t *pos)
802	__acquires(RCU)
803{
804	struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
805
806	state->pid_ns = proc_pid_ns(file_inode(seq->file)->i_sb);
807
808	rcu_read_lock();
809	return *pos ? ip6fl_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
810}
811
812static void *ip6fl_seq_next(struct seq_file *seq, void *v, loff_t *pos)
813{
814	struct ip6_flowlabel *fl;
815
816	if (v == SEQ_START_TOKEN)
817		fl = ip6fl_get_first(seq);
818	else
819		fl = ip6fl_get_next(seq, v);
820	++*pos;
821	return fl;
822}
823
824static void ip6fl_seq_stop(struct seq_file *seq, void *v)
825	__releases(RCU)
826{
827	rcu_read_unlock();
828}
829
830static int ip6fl_seq_show(struct seq_file *seq, void *v)
831{
832	struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
833	if (v == SEQ_START_TOKEN) {
834		seq_puts(seq, "Label S Owner  Users  Linger Expires  Dst                              Opt\n");
835	} else {
836		struct ip6_flowlabel *fl = v;
837		seq_printf(seq,
838			   "%05X %-1d %-6d %-6d %-6ld %-8ld %pi6 %-4d\n",
839			   (unsigned int)ntohl(fl->label),
840			   fl->share,
841			   ((fl->share == IPV6_FL_S_PROCESS) ?
842			    pid_nr_ns(fl->owner.pid, state->pid_ns) :
843			    ((fl->share == IPV6_FL_S_USER) ?
844			     from_kuid_munged(seq_user_ns(seq), fl->owner.uid) :
845			     0)),
846			   atomic_read(&fl->users),
847			   fl->linger/HZ,
848			   (long)(fl->expires - jiffies)/HZ,
849			   &fl->dst,
850			   fl->opt ? fl->opt->opt_nflen : 0);
851	}
852	return 0;
853}
854
855static const struct seq_operations ip6fl_seq_ops = {
856	.start	=	ip6fl_seq_start,
857	.next	=	ip6fl_seq_next,
858	.stop	=	ip6fl_seq_stop,
859	.show	=	ip6fl_seq_show,
860};
861
862static int __net_init ip6_flowlabel_proc_init(struct net *net)
863{
864	if (!proc_create_net("ip6_flowlabel", 0444, net->proc_net,
865			&ip6fl_seq_ops, sizeof(struct ip6fl_iter_state)))
866		return -ENOMEM;
867	return 0;
868}
869
870static void __net_exit ip6_flowlabel_proc_fini(struct net *net)
871{
872	remove_proc_entry("ip6_flowlabel", net->proc_net);
873}
874#else
875static inline int ip6_flowlabel_proc_init(struct net *net)
876{
877	return 0;
878}
879static inline void ip6_flowlabel_proc_fini(struct net *net)
880{
881}
882#endif
883
884static void __net_exit ip6_flowlabel_net_exit(struct net *net)
885{
886	ip6_fl_purge(net);
887	ip6_flowlabel_proc_fini(net);
888}
889
890static struct pernet_operations ip6_flowlabel_net_ops = {
891	.init = ip6_flowlabel_proc_init,
892	.exit = ip6_flowlabel_net_exit,
893};
894
895int ip6_flowlabel_init(void)
896{
897	return register_pernet_subsys(&ip6_flowlabel_net_ops);
898}
899
900void ip6_flowlabel_cleanup(void)
901{
902	static_key_deferred_flush(&ipv6_flowlabel_exclusive);
903	timer_delete(&ip6_fl_gc_timer);
904	unregister_pernet_subsys(&ip6_flowlabel_net_ops);
905}