net/ipv6/ip6_flowlabel.c - kernel/msm - Gitiles

 /*
  *	ip6_flowlabel.c		IPv6 flowlabel manager.
  *
  *	This program is free software; you can redistribute it and/or
  *      modify it under the terms of the GNU General Public License
  *      as published by the Free Software Foundation; either version
  *      2 of the License, or (at your option) any later version.
  *
  *	Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
  */

 #include <linux/capability.h>
 #include <linux/errno.h>
 #include <linux/types.h>
 #include <linux/socket.h>
 #include <linux/net.h>
 #include <linux/netdevice.h>
 #include <linux/if_arp.h>
 #include <linux/in6.h>
 #include <linux/route.h>
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
 #include <linux/slab.h>

 #include <net/net_namespace.h>
 #include <net/sock.h>

 #include <net/ipv6.h>
 #include <net/ndisc.h>
 #include <net/protocol.h>
 #include <net/ip6_route.h>
 #include <net/addrconf.h>
 #include <net/rawv6.h>
 #include <net/icmp.h>
 #include <net/transp_v6.h>

 #include <asm/uaccess.h>

 #define FL_MIN_LINGER	6	/* Minimal linger. It is set to 6sec specified
 				   in old IPv6 RFC. Well, it was reasonable value.
 				 */
 #define FL_MAX_LINGER	60	/* Maximal linger timeout */

 /* FL hash table */

 #define FL_MAX_PER_SOCK	32
 #define FL_MAX_SIZE	4096
 #define FL_HASH_MASK	255
 #define FL_HASH(l)	(ntohl(l)&FL_HASH_MASK)

 static atomic_t fl_size = ATOMIC_INIT(0);
 static struct ip6_flowlabel *fl_ht[FL_HASH_MASK+1];

 static void ip6_fl_gc(unsigned long dummy);
 static DEFINE_TIMER(ip6_fl_gc_timer, ip6_fl_gc, 0, 0);

 /* FL hash table lock: it protects only of GC */

 static DEFINE_RWLOCK(ip6_fl_lock);

 /* Big socket sock */

 static DEFINE_RWLOCK(ip6_sk_fl_lock);


 static inline struct ip6_flowlabel *__fl_lookup(struct net *net, __be32 label)
 {
 	struct ip6_flowlabel *fl;

 	for (fl=fl_ht[FL_HASH(label)]; fl; fl = fl->next) {
 		if (fl->label == label && net_eq(fl->fl_net, net))
 			return fl;
 	}
 	return NULL;
 }

 static struct ip6_flowlabel *fl_lookup(struct net *net, __be32 label)
 {
 	struct ip6_flowlabel *fl;

 	read_lock_bh(&ip6_fl_lock);
 	fl = __fl_lookup(net, label);
 	if (fl)
 		atomic_inc(&fl->users);
 	read_unlock_bh(&ip6_fl_lock);
 	return fl;
 }


 static void fl_free(struct ip6_flowlabel *fl)
 {
 	if (fl) {
 		release_net(fl->fl_net);
 		kfree(fl->opt);
 	}
 	kfree(fl);
 }

 static void fl_release(struct ip6_flowlabel *fl)
 {
 	write_lock_bh(&ip6_fl_lock);

 	fl->lastuse = jiffies;
 	if (atomic_dec_and_test(&fl->users)) {
 		unsigned long ttd = fl->lastuse + fl->linger;
 		if (time_after(ttd, fl->expires))
 			fl->expires = ttd;
 		ttd = fl->expires;
 		if (fl->opt && fl->share == IPV6_FL_S_EXCL) {
 			struct ipv6_txoptions *opt = fl->opt;
 			fl->opt = NULL;
 			kfree(opt);
 		}
 		if (!timer_pending(&ip6_fl_gc_timer) ||
 		    time_after(ip6_fl_gc_timer.expires, ttd))
 			mod_timer(&ip6_fl_gc_timer, ttd);
 	}
 	write_unlock_bh(&ip6_fl_lock);
 }

 static void ip6_fl_gc(unsigned long dummy)
 {
 	int i;
 	unsigned long now = jiffies;
 	unsigned long sched = 0;

 	write_lock(&ip6_fl_lock);

 	for (i=0; i<=FL_HASH_MASK; i++) {
 		struct ip6_flowlabel *fl, **flp;
 		flp = &fl_ht[i];
 		while ((fl=*flp) != NULL) {
 			if (atomic_read(&fl->users) == 0) {
 				unsigned long ttd = fl->lastuse + fl->linger;
 				if (time_after(ttd, fl->expires))
 					fl->expires = ttd;
 				ttd = fl->expires;
 				if (time_after_eq(now, ttd)) {
 					*flp = fl->next;
 					fl_free(fl);
 					atomic_dec(&fl_size);
 					continue;
 				}
 				if (!sched || time_before(ttd, sched))
 					sched = ttd;
 			}
 			flp = &fl->next;
 		}
 	}
 	if (!sched && atomic_read(&fl_size))
 		sched = now + FL_MAX_LINGER;
 	if (sched) {
 		mod_timer(&ip6_fl_gc_timer, sched);
 	}
 	write_unlock(&ip6_fl_lock);
 }

 static void __net_exit ip6_fl_purge(struct net *net)
 {
 	int i;

 	write_lock(&ip6_fl_lock);
 	for (i = 0; i <= FL_HASH_MASK; i++) {
 		struct ip6_flowlabel *fl, **flp;
 		flp = &fl_ht[i];
 		while ((fl = *flp) != NULL) {
 			if (net_eq(fl->fl_net, net) &&
 			    atomic_read(&fl->users) == 0) {
 				*flp = fl->next;
 				fl_free(fl);
 				atomic_dec(&fl_size);
 				continue;
 			}
 			flp = &fl->next;
 		}
 	}
 	write_unlock(&ip6_fl_lock);
 }

 static struct ip6_flowlabel *fl_intern(struct net *net,
 				       struct ip6_flowlabel *fl, __be32 label)
 {
 	struct ip6_flowlabel *lfl;

 	fl->label = label & IPV6_FLOWLABEL_MASK;

 	write_lock_bh(&ip6_fl_lock);
 	if (label == 0) {
 		for (;;) {
 			fl->label = htonl(net_random())&IPV6_FLOWLABEL_MASK;
 			if (fl->label) {
 				lfl = __fl_lookup(net, fl->label);
 				if (lfl == NULL)
 					break;
 			}
 		}
 	} else {
 		/*
 		 * we dropper the ip6_fl_lock, so this entry could reappear
 		 * and we need to recheck with it.
 		 *
 		 * OTOH no need to search the active socket first, like it is
 		 * done in ipv6_flowlabel_opt - sock is locked, so new entry
 		 * with the same label can only appear on another sock
 		 */
 		lfl = __fl_lookup(net, fl->label);
 		if (lfl != NULL) {
 			atomic_inc(&lfl->users);
 			write_unlock_bh(&ip6_fl_lock);
 			return lfl;
 		}
 	}

 	fl->lastuse = jiffies;
 	fl->next = fl_ht[FL_HASH(fl->label)];
 	fl_ht[FL_HASH(fl->label)] = fl;
 	atomic_inc(&fl_size);
 	write_unlock_bh(&ip6_fl_lock);
 	return NULL;
 }


 /* Socket flowlabel lists */

 struct ip6_flowlabel * fl6_sock_lookup(struct sock *sk, __be32 label)
 {
 	struct ipv6_fl_socklist *sfl;
 	struct ipv6_pinfo *np = inet6_sk(sk);

 	label &= IPV6_FLOWLABEL_MASK;

 	read_lock_bh(&ip6_sk_fl_lock);
 	for (sfl=np->ipv6_fl_list; sfl; sfl = sfl->next) {
 		struct ip6_flowlabel *fl = sfl->fl;
 		if (fl->label == label) {
 			fl->lastuse = jiffies;
 			atomic_inc(&fl->users);
 			read_unlock_bh(&ip6_sk_fl_lock);
 			return fl;
 		}
 	}
 	read_unlock_bh(&ip6_sk_fl_lock);
 	return NULL;
 }

 EXPORT_SYMBOL_GPL(fl6_sock_lookup);

 void fl6_free_socklist(struct sock *sk)
 {
 	struct ipv6_pinfo *np = inet6_sk(sk);
 	struct ipv6_fl_socklist *sfl;

 	while ((sfl = np->ipv6_fl_list) != NULL) {
 		np->ipv6_fl_list = sfl->next;
 		fl_release(sfl->fl);
 		kfree(sfl);
 	}
 }

 /* Service routines */


 /*
    It is the only difficult place. flowlabel enforces equal headers
    before and including routing header, however user may supply options
    following rthdr.
  */

 struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions * opt_space,
 					 struct ip6_flowlabel * fl,
 					 struct ipv6_txoptions * fopt)
 {
 	struct ipv6_txoptions * fl_opt = fl->opt;

 	if (fopt == NULL || fopt->opt_flen == 0)
 		return fl_opt;

 	if (fl_opt != NULL) {
 		opt_space->hopopt = fl_opt->hopopt;
 		opt_space->dst0opt = fl_opt->dst0opt;
 		opt_space->srcrt = fl_opt->srcrt;
 		opt_space->opt_nflen = fl_opt->opt_nflen;
 	} else {
 		if (fopt->opt_nflen == 0)
 			return fopt;
 		opt_space->hopopt = NULL;
 		opt_space->dst0opt = NULL;
 		opt_space->srcrt = NULL;
 		opt_space->opt_nflen = 0;
 	}
 	opt_space->dst1opt = fopt->dst1opt;
 	opt_space->opt_flen = fopt->opt_flen;
 	return opt_space;
 }

 static unsigned long check_linger(unsigned long ttl)
 {
 	if (ttl < FL_MIN_LINGER)
 		return FL_MIN_LINGER*HZ;
 	if (ttl > FL_MAX_LINGER && !capable(CAP_NET_ADMIN))
 		return 0;
 	return ttl*HZ;
 }

 static int fl6_renew(struct ip6_flowlabel *fl, unsigned long linger, unsigned long expires)
 {
 	linger = check_linger(linger);
 	if (!linger)
 		return -EPERM;
 	expires = check_linger(expires);
 	if (!expires)
 		return -EPERM;
 	fl->lastuse = jiffies;
 	if (time_before(fl->linger, linger))
 		fl->linger = linger;
 	if (time_before(expires, fl->linger))
 		expires = fl->linger;
 	if (time_before(fl->expires, fl->lastuse + expires))
 		fl->expires = fl->lastuse + expires;
 	return 0;
 }

 static struct ip6_flowlabel *
 fl_create(struct net *net, struct in6_flowlabel_req *freq, char __user *optval,
 	  int optlen, int *err_p)
 {
 	struct ip6_flowlabel *fl = NULL;
 	int olen;
 	int addr_type;
 	int err;

 	olen = optlen - CMSG_ALIGN(sizeof(*freq));
 	err = -EINVAL;
 	if (olen > 64 * 1024)
 		goto done;

 	err = -ENOMEM;
 	fl = kzalloc(sizeof(*fl), GFP_KERNEL);
 	if (fl == NULL)
 		goto done;

 	if (olen > 0) {
 		struct msghdr msg;
 		struct flowi flowi;
 		int junk;

 		err = -ENOMEM;
 		fl->opt = kmalloc(sizeof(*fl->opt) + olen, GFP_KERNEL);
 		if (fl->opt == NULL)
 			goto done;

 		memset(fl->opt, 0, sizeof(*fl->opt));
 		fl->opt->tot_len = sizeof(*fl->opt) + olen;
 		err = -EFAULT;
 		if (copy_from_user(fl->opt+1, optval+CMSG_ALIGN(sizeof(*freq)), olen))
 			goto done;

 		msg.msg_controllen = olen;
 		msg.msg_control = (void*)(fl->opt+1);
 		flowi.oif = 0;

 		err = datagram_send_ctl(net, &msg, &flowi, fl->opt, &junk, &junk);
 		if (err)
 			goto done;
 		err = -EINVAL;
 		if (fl->opt->opt_flen)
 			goto done;
 		if (fl->opt->opt_nflen == 0) {
 			kfree(fl->opt);
 			fl->opt = NULL;
 		}
 	}

 	fl->fl_net = hold_net(net);
 	fl->expires = jiffies;
 	err = fl6_renew(fl, freq->flr_linger, freq->flr_expires);
 	if (err)
 		goto done;
 	fl->share = freq->flr_share;
 	addr_type = ipv6_addr_type(&freq->flr_dst);
 	if ((addr_type & IPV6_ADDR_MAPPED) ||
 	    addr_type == IPV6_ADDR_ANY) {
 		err = -EINVAL;
 		goto done;
 	}
 	ipv6_addr_copy(&fl->dst, &freq->flr_dst);
 	atomic_set(&fl->users, 1);
 	switch (fl->share) {
 	case IPV6_FL_S_EXCL:
 	case IPV6_FL_S_ANY:
 		break;
 	case IPV6_FL_S_PROCESS:
 		fl->owner = current->pid;
 		break;
 	case IPV6_FL_S_USER:
 		fl->owner = current_euid();
 		break;
 	default:
 		err = -EINVAL;
 		goto done;
 	}
 	return fl;

 done:
 	fl_free(fl);
 	*err_p = err;
 	return NULL;
 }

 static int mem_check(struct sock *sk)
 {
 	struct ipv6_pinfo *np = inet6_sk(sk);
 	struct ipv6_fl_socklist *sfl;
 	int room = FL_MAX_SIZE - atomic_read(&fl_size);
 	int count = 0;

 	if (room > FL_MAX_SIZE - FL_MAX_PER_SOCK)
 		return 0;

 	for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next)
 		count++;

 	if (room <= 0 ||
 	    ((count >= FL_MAX_PER_SOCK ||
 	      (count > 0 && room < FL_MAX_SIZE/2) || room < FL_MAX_SIZE/4) &&
 	     !capable(CAP_NET_ADMIN)))
 		return -ENOBUFS;

 	return 0;
 }

 static int ipv6_hdr_cmp(struct ipv6_opt_hdr *h1, struct ipv6_opt_hdr *h2)
 {
 	if (h1 == h2)
 		return 0;
 	if (h1 == NULL || h2 == NULL)
 		return 1;
 	if (h1->hdrlen != h2->hdrlen)
 		return 1;
 	return memcmp(h1+1, h2+1, ((h1->hdrlen+1)<<3) - sizeof(*h1));
 }

 static int ipv6_opt_cmp(struct ipv6_txoptions *o1, struct ipv6_txoptions *o2)
 {
 	if (o1 == o2)
 		return 0;
 	if (o1 == NULL || o2 == NULL)
 		return 1;
 	if (o1->opt_nflen != o2->opt_nflen)
 		return 1;
 	if (ipv6_hdr_cmp(o1->hopopt, o2->hopopt))
 		return 1;
 	if (ipv6_hdr_cmp(o1->dst0opt, o2->dst0opt))
 		return 1;
 	if (ipv6_hdr_cmp((struct ipv6_opt_hdr *)o1->srcrt, (struct ipv6_opt_hdr *)o2->srcrt))
 		return 1;
 	return 0;
 }

 static inline void fl_link(struct ipv6_pinfo *np, struct ipv6_fl_socklist *sfl,
 		struct ip6_flowlabel *fl)
 {
 	write_lock_bh(&ip6_sk_fl_lock);
 	sfl->fl = fl;
 	sfl->next = np->ipv6_fl_list;
 	np->ipv6_fl_list = sfl;
 	write_unlock_bh(&ip6_sk_fl_lock);
 }

 int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen)
 {
 	int uninitialized_var(err);
 	struct net *net = sock_net(sk);
 	struct ipv6_pinfo *np = inet6_sk(sk);
 	struct in6_flowlabel_req freq;
 	struct ipv6_fl_socklist *sfl1=NULL;
 	struct ipv6_fl_socklist *sfl, **sflp;
 	struct ip6_flowlabel *fl, *fl1 = NULL;


 	if (optlen < sizeof(freq))
 		return -EINVAL;

 	if (copy_from_user(&freq, optval, sizeof(freq)))
 		return -EFAULT;

 	switch (freq.flr_action) {
 	case IPV6_FL_A_PUT:
 		write_lock_bh(&ip6_sk_fl_lock);
 		for (sflp = &np->ipv6_fl_list; (sfl=*sflp)!=NULL; sflp = &sfl->next) {
 			if (sfl->fl->label == freq.flr_label) {
 				if (freq.flr_label == (np->flow_label&IPV6_FLOWLABEL_MASK))
 					np->flow_label &= ~IPV6_FLOWLABEL_MASK;
 				*sflp = sfl->next;
 				write_unlock_bh(&ip6_sk_fl_lock);
 				fl_release(sfl->fl);
 				kfree(sfl);
 				return 0;
 			}
 		}
 		write_unlock_bh(&ip6_sk_fl_lock);
 		return -ESRCH;

 	case IPV6_FL_A_RENEW:
 		read_lock_bh(&ip6_sk_fl_lock);
 		for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next) {
 			if (sfl->fl->label == freq.flr_label) {
 				err = fl6_renew(sfl->fl, freq.flr_linger, freq.flr_expires);
 				read_unlock_bh(&ip6_sk_fl_lock);
 				return err;
 			}
 		}
 		read_unlock_bh(&ip6_sk_fl_lock);

 		if (freq.flr_share == IPV6_FL_S_NONE && capable(CAP_NET_ADMIN)) {
 			fl = fl_lookup(net, freq.flr_label);
 			if (fl) {
 				err = fl6_renew(fl, freq.flr_linger, freq.flr_expires);
 				fl_release(fl);
 				return err;
 			}
 		}
 		return -ESRCH;

 	case IPV6_FL_A_GET:
 		if (freq.flr_label & ~IPV6_FLOWLABEL_MASK)
 			return -EINVAL;

 		fl = fl_create(net, &freq, optval, optlen, &err);
 		if (fl == NULL)
 			return err;
 		sfl1 = kmalloc(sizeof(*sfl1), GFP_KERNEL);

 		if (freq.flr_label) {
 			err = -EEXIST;
 			read_lock_bh(&ip6_sk_fl_lock);
 			for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next) {
 				if (sfl->fl->label == freq.flr_label) {
 					if (freq.flr_flags&IPV6_FL_F_EXCL) {
 						read_unlock_bh(&ip6_sk_fl_lock);
 						goto done;
 					}
 					fl1 = sfl->fl;
 					atomic_inc(&fl1->users);
 					break;
 				}
 			}
 			read_unlock_bh(&ip6_sk_fl_lock);

 			if (fl1 == NULL)
 				fl1 = fl_lookup(net, freq.flr_label);
 			if (fl1) {
 recheck:
 				err = -EEXIST;
 				if (freq.flr_flags&IPV6_FL_F_EXCL)
 					goto release;
 				err = -EPERM;
 				if (fl1->share == IPV6_FL_S_EXCL ||
 				    fl1->share != fl->share ||
 				    fl1->owner != fl->owner)
 					goto release;

 				err = -EINVAL;
 				if (!ipv6_addr_equal(&fl1->dst, &fl->dst) ||
 				    ipv6_opt_cmp(fl1->opt, fl->opt))
 					goto release;

 				err = -ENOMEM;
 				if (sfl1 == NULL)
 					goto release;
 				if (fl->linger > fl1->linger)
 					fl1->linger = fl->linger;
 				if ((long)(fl->expires - fl1->expires) > 0)
 					fl1->expires = fl->expires;
 				fl_link(np, sfl1, fl1);
 				fl_free(fl);
 				return 0;

 release:
 				fl_release(fl1);
 				goto done;
 			}
 		}
 		err = -ENOENT;
 		if (!(freq.flr_flags&IPV6_FL_F_CREATE))
 			goto done;

 		err = -ENOMEM;
 		if (sfl1 == NULL || (err = mem_check(sk)) != 0)
 			goto done;

 		fl1 = fl_intern(net, fl, freq.flr_label);
 		if (fl1 != NULL)
 			goto recheck;

 		if (!freq.flr_label) {
 			if (copy_to_user(&((struct in6_flowlabel_req __user *) optval)->flr_label,
 					 &fl->label, sizeof(fl->label))) {
 				/* Intentionally ignore fault. */
 			}
 		}

 		fl_link(np, sfl1, fl);
 		return 0;

 	default:
 		return -EINVAL;
 	}

 done:
 	fl_free(fl);
 	kfree(sfl1);
 	return err;
 }

 #ifdef CONFIG_PROC_FS

 struct ip6fl_iter_state {
 	struct seq_net_private p;
 	int bucket;
 };

 #define ip6fl_seq_private(seq)	((struct ip6fl_iter_state *)(seq)->private)

 static struct ip6_flowlabel *ip6fl_get_first(struct seq_file *seq)
 {
 	struct ip6_flowlabel *fl = NULL;
 	struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 	struct net *net = seq_file_net(seq);

 	for (state->bucket = 0; state->bucket <= FL_HASH_MASK; ++state->bucket) {
 		fl = fl_ht[state->bucket];

 		while (fl && !net_eq(fl->fl_net, net))
 			fl = fl->next;
 		if (fl)
 			break;
 	}
 	return fl;
 }

 static struct ip6_flowlabel *ip6fl_get_next(struct seq_file *seq, struct ip6_flowlabel *fl)
 {
 	struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
 	struct net *net = seq_file_net(seq);

 	fl = fl->next;
 try_again:
 	while (fl && !net_eq(fl->fl_net, net))
 		fl = fl->next;

 	while (!fl) {
 		if (++state->bucket <= FL_HASH_MASK) {
 			fl = fl_ht[state->bucket];
 			goto try_again;
 		} else
 			break;
 	}
 	return fl;
 }

 static struct ip6_flowlabel *ip6fl_get_idx(struct seq_file *seq, loff_t pos)
 {
 	struct ip6_flowlabel *fl = ip6fl_get_first(seq);
 	if (fl)
 		while (pos && (fl = ip6fl_get_next(seq, fl)) != NULL)
 			--pos;
 	return pos ? NULL : fl;
 }

 static void *ip6fl_seq_start(struct seq_file *seq, loff_t *pos)
 	__acquires(ip6_fl_lock)
 {
 	read_lock_bh(&ip6_fl_lock);
 	return *pos ? ip6fl_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
 }

 static void *ip6fl_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 {
 	struct ip6_flowlabel *fl;

 	if (v == SEQ_START_TOKEN)
 		fl = ip6fl_get_first(seq);
 	else
 		fl = ip6fl_get_next(seq, v);
 	++*pos;
 	return fl;
 }

 static void ip6fl_seq_stop(struct seq_file *seq, void *v)
 	__releases(ip6_fl_lock)
 {
 	read_unlock_bh(&ip6_fl_lock);
 }

 static int ip6fl_seq_show(struct seq_file *seq, void *v)
 {
 	if (v == SEQ_START_TOKEN)
 		seq_printf(seq, "%-5s %-1s %-6s %-6s %-6s %-8s %-32s %s\n",
 			   "Label", "S", "Owner", "Users", "Linger", "Expires", "Dst", "Opt");
 	else {
 		struct ip6_flowlabel *fl = v;
 		seq_printf(seq,
 			   "%05X %-1d %-6d %-6d %-6ld %-8ld %pi6 %-4d\n",
 			   (unsigned)ntohl(fl->label),
 			   fl->share,
 			   (unsigned)fl->owner,
 			   atomic_read(&fl->users),
 			   fl->linger/HZ,
 			   (long)(fl->expires - jiffies)/HZ,
 			   &fl->dst,
 			   fl->opt ? fl->opt->opt_nflen : 0);
 	}
 	return 0;
 }

 static const struct seq_operations ip6fl_seq_ops = {
 	.start	=	ip6fl_seq_start,
 	.next	=	ip6fl_seq_next,
 	.stop	=	ip6fl_seq_stop,
 	.show	=	ip6fl_seq_show,
 };

 static int ip6fl_seq_open(struct inode *inode, struct file *file)
 {
 	return seq_open_net(inode, file, &ip6fl_seq_ops,
 			    sizeof(struct ip6fl_iter_state));
 }

 static const struct file_operations ip6fl_seq_fops = {
 	.owner		=	THIS_MODULE,
 	.open		=	ip6fl_seq_open,
 	.read		=	seq_read,
 	.llseek		=	seq_lseek,
 	.release	=	seq_release_net,
 };

 static int __net_init ip6_flowlabel_proc_init(struct net *net)
 {
 	if (!proc_net_fops_create(net, "ip6_flowlabel",
 				  S_IRUGO, &ip6fl_seq_fops))
 		return -ENOMEM;
 	return 0;
 }

 static void __net_exit ip6_flowlabel_proc_fini(struct net *net)
 {
 	proc_net_remove(net, "ip6_flowlabel");
 }
 #else
 static inline int ip6_flowlabel_proc_init(struct net *net)
 {
 	return 0;
 }
 static inline void ip6_flowlabel_proc_fini(struct net *net)
 {
 }
 #endif

 static void __net_exit ip6_flowlabel_net_exit(struct net *net)
 {
 	ip6_fl_purge(net);
 	ip6_flowlabel_proc_fini(net);
 }

 static struct pernet_operations ip6_flowlabel_net_ops = {
 	.init = ip6_flowlabel_proc_init,
 	.exit = ip6_flowlabel_net_exit,
 };

 int ip6_flowlabel_init(void)
 {
 	return register_pernet_subsys(&ip6_flowlabel_net_ops);
 }

 void ip6_flowlabel_cleanup(void)
 {
 	del_timer(&ip6_fl_gc_timer);
 	unregister_pernet_subsys(&ip6_flowlabel_net_ops);
 }
	/*
	* ip6_flowlabel.c IPv6 flowlabel manager.
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License
	* as published by the Free Software Foundation; either version
	* 2 of the License, or (at your option) any later version.
	*
	* Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
	*/

	#include <linux/capability.h>
	#include <linux/errno.h>
	#include <linux/types.h>
	#include <linux/socket.h>
	#include <linux/net.h>
	#include <linux/netdevice.h>
	#include <linux/if_arp.h>
	#include <linux/in6.h>
	#include <linux/route.h>
	#include <linux/proc_fs.h>
	#include <linux/seq_file.h>
	#include <linux/slab.h>

	#include <net/net_namespace.h>
	#include <net/sock.h>

	#include <net/ipv6.h>
	#include <net/ndisc.h>
	#include <net/protocol.h>
	#include <net/ip6_route.h>
	#include <net/addrconf.h>
	#include <net/rawv6.h>
	#include <net/icmp.h>
	#include <net/transp_v6.h>

	#include <asm/uaccess.h>

	#define FL_MIN_LINGER 6 /* Minimal linger. It is set to 6sec specified
	in old IPv6 RFC. Well, it was reasonable value.
	*/
	#define FL_MAX_LINGER 60 /* Maximal linger timeout */

	/* FL hash table */

	#define FL_MAX_PER_SOCK 32
	#define FL_MAX_SIZE 4096
	#define FL_HASH_MASK 255
	#define FL_HASH(l) (ntohl(l)&FL_HASH_MASK)

	static atomic_t fl_size = ATOMIC_INIT(0);
	static struct ip6_flowlabel *fl_ht[FL_HASH_MASK+1];

	static void ip6_fl_gc(unsigned long dummy);
	static DEFINE_TIMER(ip6_fl_gc_timer, ip6_fl_gc, 0, 0);

	/* FL hash table lock: it protects only of GC */

	static DEFINE_RWLOCK(ip6_fl_lock);

	/* Big socket sock */

	static DEFINE_RWLOCK(ip6_sk_fl_lock);


	static inline struct ip6_flowlabel __fl_lookup(struct net net, __be32 label)
	{
	struct ip6_flowlabel *fl;

	for (fl=fl_ht[FL_HASH(label)]; fl; fl = fl->next) {
	if (fl->label == label && net_eq(fl->fl_net, net))
	return fl;
	}
	return NULL;
	}

	static struct ip6_flowlabel fl_lookup(struct net net, __be32 label)
	{
	struct ip6_flowlabel *fl;

	read_lock_bh(&ip6_fl_lock);
	fl = __fl_lookup(net, label);
	if (fl)
	atomic_inc(&fl->users);
	read_unlock_bh(&ip6_fl_lock);
	return fl;
	}


	static void fl_free(struct ip6_flowlabel *fl)
	{
	if (fl) {
	release_net(fl->fl_net);
	kfree(fl->opt);
	}
	kfree(fl);
	}

	static void fl_release(struct ip6_flowlabel *fl)
	{
	write_lock_bh(&ip6_fl_lock);

	fl->lastuse = jiffies;
	if (atomic_dec_and_test(&fl->users)) {
	unsigned long ttd = fl->lastuse + fl->linger;
	if (time_after(ttd, fl->expires))
	fl->expires = ttd;
	ttd = fl->expires;
	if (fl->opt && fl->share == IPV6_FL_S_EXCL) {
	struct ipv6_txoptions *opt = fl->opt;
	fl->opt = NULL;
	kfree(opt);
	}
	if (!timer_pending(&ip6_fl_gc_timer) \|\|
	time_after(ip6_fl_gc_timer.expires, ttd))
	mod_timer(&ip6_fl_gc_timer, ttd);
	}
	write_unlock_bh(&ip6_fl_lock);
	}

	static void ip6_fl_gc(unsigned long dummy)
	{
	int i;
	unsigned long now = jiffies;
	unsigned long sched = 0;

	write_lock(&ip6_fl_lock);

	for (i=0; i<=FL_HASH_MASK; i++) {
	struct ip6_flowlabel fl, *flp;
	flp = &fl_ht[i];
	while ((fl=*flp) != NULL) {
	if (atomic_read(&fl->users) == 0) {
	unsigned long ttd = fl->lastuse + fl->linger;
	if (time_after(ttd, fl->expires))
	fl->expires = ttd;
	ttd = fl->expires;
	if (time_after_eq(now, ttd)) {
	*flp = fl->next;
	fl_free(fl);
	atomic_dec(&fl_size);
	continue;
	}
	if (!sched \|\| time_before(ttd, sched))
	sched = ttd;
	}
	flp = &fl->next;
	}
	}
	if (!sched && atomic_read(&fl_size))
	sched = now + FL_MAX_LINGER;
	if (sched) {
	mod_timer(&ip6_fl_gc_timer, sched);
	}
	write_unlock(&ip6_fl_lock);
	}

	static void __net_exit ip6_fl_purge(struct net *net)
	{
	int i;

	write_lock(&ip6_fl_lock);
	for (i = 0; i <= FL_HASH_MASK; i++) {
	struct ip6_flowlabel fl, *flp;
	flp = &fl_ht[i];
	while ((fl = *flp) != NULL) {
	if (net_eq(fl->fl_net, net) &&
	atomic_read(&fl->users) == 0) {
	*flp = fl->next;
	fl_free(fl);
	atomic_dec(&fl_size);
	continue;
	}
	flp = &fl->next;
	}
	}
	write_unlock(&ip6_fl_lock);
	}

	static struct ip6_flowlabel fl_intern(struct net net,
	struct ip6_flowlabel *fl, __be32 label)
	{
	struct ip6_flowlabel *lfl;

	fl->label = label & IPV6_FLOWLABEL_MASK;

	write_lock_bh(&ip6_fl_lock);
	if (label == 0) {
	for (;;) {
	fl->label = htonl(net_random())&IPV6_FLOWLABEL_MASK;
	if (fl->label) {
	lfl = __fl_lookup(net, fl->label);
	if (lfl == NULL)
	break;
	}
	}
	} else {
	/*
	* we dropper the ip6_fl_lock, so this entry could reappear
	* and we need to recheck with it.
	*
	* OTOH no need to search the active socket first, like it is
	* done in ipv6_flowlabel_opt - sock is locked, so new entry
	* with the same label can only appear on another sock
	*/
	lfl = __fl_lookup(net, fl->label);
	if (lfl != NULL) {
	atomic_inc(&lfl->users);
	write_unlock_bh(&ip6_fl_lock);
	return lfl;
	}
	}

	fl->lastuse = jiffies;
	fl->next = fl_ht[FL_HASH(fl->label)];
	fl_ht[FL_HASH(fl->label)] = fl;
	atomic_inc(&fl_size);
	write_unlock_bh(&ip6_fl_lock);
	return NULL;
	}



	/* Socket flowlabel lists */

	struct ip6_flowlabel * fl6_sock_lookup(struct sock *sk, __be32 label)
	{
	struct ipv6_fl_socklist *sfl;
	struct ipv6_pinfo *np = inet6_sk(sk);

	label &= IPV6_FLOWLABEL_MASK;

	read_lock_bh(&ip6_sk_fl_lock);
	for (sfl=np->ipv6_fl_list; sfl; sfl = sfl->next) {
	struct ip6_flowlabel *fl = sfl->fl;
	if (fl->label == label) {
	fl->lastuse = jiffies;
	atomic_inc(&fl->users);
	read_unlock_bh(&ip6_sk_fl_lock);
	return fl;
	}
	}
	read_unlock_bh(&ip6_sk_fl_lock);
	return NULL;
	}

	EXPORT_SYMBOL_GPL(fl6_sock_lookup);

	void fl6_free_socklist(struct sock *sk)
	{
	struct ipv6_pinfo *np = inet6_sk(sk);
	struct ipv6_fl_socklist *sfl;

	while ((sfl = np->ipv6_fl_list) != NULL) {
	np->ipv6_fl_list = sfl->next;
	fl_release(sfl->fl);
	kfree(sfl);
	}
	}

	/* Service routines */


	/*
	It is the only difficult place. flowlabel enforces equal headers
	before and including routing header, however user may supply options
	following rthdr.
	*/

	struct ipv6_txoptions fl6_merge_options(struct ipv6_txoptions opt_space,
	struct ip6_flowlabel * fl,
	struct ipv6_txoptions * fopt)
	{
	struct ipv6_txoptions * fl_opt = fl->opt;

	if (fopt == NULL \|\| fopt->opt_flen == 0)
	return fl_opt;

	if (fl_opt != NULL) {
	opt_space->hopopt = fl_opt->hopopt;
	opt_space->dst0opt = fl_opt->dst0opt;
	opt_space->srcrt = fl_opt->srcrt;
	opt_space->opt_nflen = fl_opt->opt_nflen;
	} else {
	if (fopt->opt_nflen == 0)
	return fopt;
	opt_space->hopopt = NULL;
	opt_space->dst0opt = NULL;
	opt_space->srcrt = NULL;
	opt_space->opt_nflen = 0;
	}
	opt_space->dst1opt = fopt->dst1opt;
	opt_space->opt_flen = fopt->opt_flen;
	return opt_space;
	}

	static unsigned long check_linger(unsigned long ttl)
	{
	if (ttl < FL_MIN_LINGER)
	return FL_MIN_LINGER*HZ;
	if (ttl > FL_MAX_LINGER && !capable(CAP_NET_ADMIN))
	return 0;
	return ttl*HZ;
	}

	static int fl6_renew(struct ip6_flowlabel *fl, unsigned long linger, unsigned long expires)
	{
	linger = check_linger(linger);
	if (!linger)
	return -EPERM;
	expires = check_linger(expires);
	if (!expires)
	return -EPERM;
	fl->lastuse = jiffies;
	if (time_before(fl->linger, linger))
	fl->linger = linger;
	if (time_before(expires, fl->linger))
	expires = fl->linger;
	if (time_before(fl->expires, fl->lastuse + expires))
	fl->expires = fl->lastuse + expires;
	return 0;
	}

	static struct ip6_flowlabel *
	fl_create(struct net net, struct in6_flowlabel_req freq, char __user *optval,
	int optlen, int *err_p)
	{
	struct ip6_flowlabel *fl = NULL;
	int olen;
	int addr_type;
	int err;

	olen = optlen - CMSG_ALIGN(sizeof(*freq));
	err = -EINVAL;
	if (olen > 64 * 1024)
	goto done;

	err = -ENOMEM;
	fl = kzalloc(sizeof(*fl), GFP_KERNEL);
	if (fl == NULL)
	goto done;

	if (olen > 0) {
	struct msghdr msg;
	struct flowi flowi;
	int junk;

	err = -ENOMEM;
	fl->opt = kmalloc(sizeof(*fl->opt) + olen, GFP_KERNEL);
	if (fl->opt == NULL)
	goto done;

	memset(fl->opt, 0, sizeof(*fl->opt));
	fl->opt->tot_len = sizeof(*fl->opt) + olen;
	err = -EFAULT;
	if (copy_from_user(fl->opt+1, optval+CMSG_ALIGN(sizeof(*freq)), olen))
	goto done;

	msg.msg_controllen = olen;
	msg.msg_control = (void*)(fl->opt+1);
	flowi.oif = 0;

	err = datagram_send_ctl(net, &msg, &flowi, fl->opt, &junk, &junk);
	if (err)
	goto done;
	err = -EINVAL;
	if (fl->opt->opt_flen)
	goto done;
	if (fl->opt->opt_nflen == 0) {
	kfree(fl->opt);
	fl->opt = NULL;
	}
	}

	fl->fl_net = hold_net(net);
	fl->expires = jiffies;
	err = fl6_renew(fl, freq->flr_linger, freq->flr_expires);
	if (err)
	goto done;
	fl->share = freq->flr_share;
	addr_type = ipv6_addr_type(&freq->flr_dst);
	if ((addr_type & IPV6_ADDR_MAPPED) \|\|
	addr_type == IPV6_ADDR_ANY) {
	err = -EINVAL;
	goto done;
	}
	ipv6_addr_copy(&fl->dst, &freq->flr_dst);
	atomic_set(&fl->users, 1);
	switch (fl->share) {
	case IPV6_FL_S_EXCL:
	case IPV6_FL_S_ANY:
	break;
	case IPV6_FL_S_PROCESS:
	fl->owner = current->pid;
	break;
	case IPV6_FL_S_USER:
	fl->owner = current_euid();
	break;
	default:
	err = -EINVAL;
	goto done;
	}
	return fl;

	done:
	fl_free(fl);
	*err_p = err;
	return NULL;
	}

	static int mem_check(struct sock *sk)
	{
	struct ipv6_pinfo *np = inet6_sk(sk);
	struct ipv6_fl_socklist *sfl;
	int room = FL_MAX_SIZE - atomic_read(&fl_size);
	int count = 0;

	if (room > FL_MAX_SIZE - FL_MAX_PER_SOCK)
	return 0;

	for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next)
	count++;

	if (room <= 0 \|\|
	((count >= FL_MAX_PER_SOCK \|\|
	(count > 0 && room < FL_MAX_SIZE/2) \|\| room < FL_MAX_SIZE/4) &&
	!capable(CAP_NET_ADMIN)))
	return -ENOBUFS;

	return 0;
	}

	static int ipv6_hdr_cmp(struct ipv6_opt_hdr h1, struct ipv6_opt_hdr h2)
	{
	if (h1 == h2)
	return 0;
	if (h1 == NULL \|\| h2 == NULL)
	return 1;
	if (h1->hdrlen != h2->hdrlen)
	return 1;
	return memcmp(h1+1, h2+1, ((h1->hdrlen+1)<<3) - sizeof(*h1));
	}

	static int ipv6_opt_cmp(struct ipv6_txoptions o1, struct ipv6_txoptions o2)
	{
	if (o1 == o2)
	return 0;
	if (o1 == NULL \|\| o2 == NULL)
	return 1;
	if (o1->opt_nflen != o2->opt_nflen)
	return 1;
	if (ipv6_hdr_cmp(o1->hopopt, o2->hopopt))
	return 1;
	if (ipv6_hdr_cmp(o1->dst0opt, o2->dst0opt))
	return 1;
	if (ipv6_hdr_cmp((struct ipv6_opt_hdr )o1->srcrt, (struct ipv6_opt_hdr )o2->srcrt))
	return 1;
	return 0;
	}

	static inline void fl_link(struct ipv6_pinfo np, struct ipv6_fl_socklist sfl,
	struct ip6_flowlabel *fl)
	{
	write_lock_bh(&ip6_sk_fl_lock);
	sfl->fl = fl;
	sfl->next = np->ipv6_fl_list;
	np->ipv6_fl_list = sfl;
	write_unlock_bh(&ip6_sk_fl_lock);
	}

	int ipv6_flowlabel_opt(struct sock sk, char __user optval, int optlen)
	{
	int uninitialized_var(err);
	struct net *net = sock_net(sk);
	struct ipv6_pinfo *np = inet6_sk(sk);
	struct in6_flowlabel_req freq;
	struct ipv6_fl_socklist *sfl1=NULL;
	struct ipv6_fl_socklist sfl, *sflp;
	struct ip6_flowlabel fl, fl1 = NULL;


	if (optlen < sizeof(freq))
	return -EINVAL;

	if (copy_from_user(&freq, optval, sizeof(freq)))
	return -EFAULT;

	switch (freq.flr_action) {
	case IPV6_FL_A_PUT:
	write_lock_bh(&ip6_sk_fl_lock);
	for (sflp = &np->ipv6_fl_list; (sfl=*sflp)!=NULL; sflp = &sfl->next) {
	if (sfl->fl->label == freq.flr_label) {
	if (freq.flr_label == (np->flow_label&IPV6_FLOWLABEL_MASK))
	np->flow_label &= ~IPV6_FLOWLABEL_MASK;
	*sflp = sfl->next;
	write_unlock_bh(&ip6_sk_fl_lock);
	fl_release(sfl->fl);
	kfree(sfl);
	return 0;
	}
	}
	write_unlock_bh(&ip6_sk_fl_lock);
	return -ESRCH;

	case IPV6_FL_A_RENEW:
	read_lock_bh(&ip6_sk_fl_lock);
	for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next) {
	if (sfl->fl->label == freq.flr_label) {
	err = fl6_renew(sfl->fl, freq.flr_linger, freq.flr_expires);
	read_unlock_bh(&ip6_sk_fl_lock);
	return err;
	}
	}
	read_unlock_bh(&ip6_sk_fl_lock);

	if (freq.flr_share == IPV6_FL_S_NONE && capable(CAP_NET_ADMIN)) {
	fl = fl_lookup(net, freq.flr_label);
	if (fl) {
	err = fl6_renew(fl, freq.flr_linger, freq.flr_expires);
	fl_release(fl);
	return err;
	}
	}
	return -ESRCH;

	case IPV6_FL_A_GET:
	if (freq.flr_label & ~IPV6_FLOWLABEL_MASK)
	return -EINVAL;

	fl = fl_create(net, &freq, optval, optlen, &err);
	if (fl == NULL)
	return err;
	sfl1 = kmalloc(sizeof(*sfl1), GFP_KERNEL);

	if (freq.flr_label) {
	err = -EEXIST;
	read_lock_bh(&ip6_sk_fl_lock);
	for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next) {
	if (sfl->fl->label == freq.flr_label) {
	if (freq.flr_flags&IPV6_FL_F_EXCL) {
	read_unlock_bh(&ip6_sk_fl_lock);
	goto done;
	}
	fl1 = sfl->fl;
	atomic_inc(&fl1->users);
	break;
	}
	}
	read_unlock_bh(&ip6_sk_fl_lock);

	if (fl1 == NULL)
	fl1 = fl_lookup(net, freq.flr_label);
	if (fl1) {
	recheck:
	err = -EEXIST;
	if (freq.flr_flags&IPV6_FL_F_EXCL)
	goto release;
	err = -EPERM;
	if (fl1->share == IPV6_FL_S_EXCL \|\|
	fl1->share != fl->share \|\|
	fl1->owner != fl->owner)
	goto release;

	err = -EINVAL;
	if (!ipv6_addr_equal(&fl1->dst, &fl->dst) \|\|
	ipv6_opt_cmp(fl1->opt, fl->opt))
	goto release;

	err = -ENOMEM;
	if (sfl1 == NULL)
	goto release;
	if (fl->linger > fl1->linger)
	fl1->linger = fl->linger;
	if ((long)(fl->expires - fl1->expires) > 0)
	fl1->expires = fl->expires;
	fl_link(np, sfl1, fl1);
	fl_free(fl);
	return 0;

	release:
	fl_release(fl1);
	goto done;
	}
	}
	err = -ENOENT;
	if (!(freq.flr_flags&IPV6_FL_F_CREATE))
	goto done;

	err = -ENOMEM;
	if (sfl1 == NULL \|\| (err = mem_check(sk)) != 0)
	goto done;

	fl1 = fl_intern(net, fl, freq.flr_label);
	if (fl1 != NULL)
	goto recheck;

	if (!freq.flr_label) {
	if (copy_to_user(&((struct in6_flowlabel_req __user *) optval)->flr_label,
	&fl->label, sizeof(fl->label))) {
	/* Intentionally ignore fault. */
	}
	}

	fl_link(np, sfl1, fl);
	return 0;

	default:
	return -EINVAL;
	}

	done:
	fl_free(fl);
	kfree(sfl1);
	return err;
	}

	#ifdef CONFIG_PROC_FS

	struct ip6fl_iter_state {
	struct seq_net_private p;
	int bucket;
	};

	#define ip6fl_seq_private(seq) ((struct ip6fl_iter_state *)(seq)->private)

	static struct ip6_flowlabel ip6fl_get_first(struct seq_file seq)
	{
	struct ip6_flowlabel *fl = NULL;
	struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
	struct net *net = seq_file_net(seq);

	for (state->bucket = 0; state->bucket <= FL_HASH_MASK; ++state->bucket) {
	fl = fl_ht[state->bucket];

	while (fl && !net_eq(fl->fl_net, net))
	fl = fl->next;
	if (fl)
	break;
	}
	return fl;
	}

	static struct ip6_flowlabel ip6fl_get_next(struct seq_file seq, struct ip6_flowlabel *fl)
	{
	struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
	struct net *net = seq_file_net(seq);

	fl = fl->next;
	try_again:
	while (fl && !net_eq(fl->fl_net, net))
	fl = fl->next;

	while (!fl) {
	if (++state->bucket <= FL_HASH_MASK) {
	fl = fl_ht[state->bucket];
	goto try_again;
	} else
	break;
	}
	return fl;
	}

	static struct ip6_flowlabel ip6fl_get_idx(struct seq_file seq, loff_t pos)
	{
	struct ip6_flowlabel *fl = ip6fl_get_first(seq);
	if (fl)
	while (pos && (fl = ip6fl_get_next(seq, fl)) != NULL)
	--pos;
	return pos ? NULL : fl;
	}

	static void ip6fl_seq_start(struct seq_file seq, loff_t *pos)
	__acquires(ip6_fl_lock)
	{
	read_lock_bh(&ip6_fl_lock);
	return pos ? ip6fl_get_idx(seq, pos - 1) : SEQ_START_TOKEN;
	}

	static void ip6fl_seq_next(struct seq_file seq, void v, loff_t pos)
	{
	struct ip6_flowlabel *fl;

	if (v == SEQ_START_TOKEN)
	fl = ip6fl_get_first(seq);
	else
	fl = ip6fl_get_next(seq, v);
	++*pos;
	return fl;
	}

	static void ip6fl_seq_stop(struct seq_file seq, void v)
	__releases(ip6_fl_lock)
	{
	read_unlock_bh(&ip6_fl_lock);
	}

	static int ip6fl_seq_show(struct seq_file seq, void v)
	{
	if (v == SEQ_START_TOKEN)
	seq_printf(seq, "%-5s %-1s %-6s %-6s %-6s %-8s %-32s %s\n",
	"Label", "S", "Owner", "Users", "Linger", "Expires", "Dst", "Opt");
	else {
	struct ip6_flowlabel *fl = v;
	seq_printf(seq,
	"%05X %-1d %-6d %-6d %-6ld %-8ld %pi6 %-4d\n",
	(unsigned)ntohl(fl->label),
	fl->share,
	(unsigned)fl->owner,
	atomic_read(&fl->users),
	fl->linger/HZ,
	(long)(fl->expires - jiffies)/HZ,
	&fl->dst,
	fl->opt ? fl->opt->opt_nflen : 0);
	}
	return 0;
	}

	static const struct seq_operations ip6fl_seq_ops = {
	.start = ip6fl_seq_start,
	.next = ip6fl_seq_next,
	.stop = ip6fl_seq_stop,
	.show = ip6fl_seq_show,
	};

	static int ip6fl_seq_open(struct inode inode, struct file file)
	{
	return seq_open_net(inode, file, &ip6fl_seq_ops,
	sizeof(struct ip6fl_iter_state));
	}

	static const struct file_operations ip6fl_seq_fops = {
	.owner = THIS_MODULE,
	.open = ip6fl_seq_open,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = seq_release_net,
	};

	static int __net_init ip6_flowlabel_proc_init(struct net *net)
	{
	if (!proc_net_fops_create(net, "ip6_flowlabel",
	S_IRUGO, &ip6fl_seq_fops))
	return -ENOMEM;
	return 0;
	}

	static void __net_exit ip6_flowlabel_proc_fini(struct net *net)
	{
	proc_net_remove(net, "ip6_flowlabel");
	}
	#else
	static inline int ip6_flowlabel_proc_init(struct net *net)
	{
	return 0;
	}
	static inline void ip6_flowlabel_proc_fini(struct net *net)
	{
	}
	#endif

	static void __net_exit ip6_flowlabel_net_exit(struct net *net)
	{
	ip6_fl_purge(net);
	ip6_flowlabel_proc_fini(net);
	}

	static struct pernet_operations ip6_flowlabel_net_ops = {
	.init = ip6_flowlabel_proc_init,
	.exit = ip6_flowlabel_net_exit,
	};

	int ip6_flowlabel_init(void)
	{
	return register_pernet_subsys(&ip6_flowlabel_net_ops);
	}

	void ip6_flowlabel_cleanup(void)
	{
	del_timer(&ip6_fl_gc_timer);
	unregister_pernet_subsys(&ip6_flowlabel_net_ops);
	}