[linux-block.git] / net / ipv6 / ip6_flowlabel.c

/*
 *	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/config.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 <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(u32 label)
{
	struct ip6_flowlabel *fl;

	for (fl=fl_ht[FL_HASH(label)]; fl; fl = fl->next) {
		if (fl->label == label)
			return fl;
	}
	return NULL;
}

static struct ip6_flowlabel * fl_lookup(u32 label)
{
	struct ip6_flowlabel *fl;

	read_lock_bh(&ip6_fl_lock);
	fl = __fl_lookup(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)
		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) {
		ip6_fl_gc_timer.expires = sched;
		add_timer(&ip6_fl_gc_timer);
	}
	write_unlock(&ip6_fl_lock);
}

static int fl_intern(struct ip6_flowlabel *fl, __u32 label)
{
	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) {
				struct ip6_flowlabel *lfl;
				lfl = __fl_lookup(fl->label);
				if (lfl == NULL)
					break;
			}
		}
	}

	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 0;
}


/* Socket flowlabel lists */

struct ip6_flowlabel * fl6_sock_lookup(struct sock *sk, u32 label)
{
	struct ipv6_fl_socklist *sfl;
	struct ipv6_pinfo *np = inet6_sk(sk);

	label &= IPV6_FLOWLABEL_MASK;

	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);
			return fl;
		}
	}
	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 in6_flowlabel_req *freq, char __user *optval, int optlen, int *err_p)
{
	struct ip6_flowlabel *fl;
	int olen;
	int addr_type;
	int err;

	err = -ENOMEM;
	fl = kmalloc(sizeof(*fl), GFP_KERNEL);
	if (fl == NULL)
		goto done;
	memset(fl, 0, sizeof(*fl));

	olen = optlen - CMSG_ALIGN(sizeof(*freq));
	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(&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->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)
		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;
}

int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen)
{
	int err;
	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;

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

		if (freq.flr_label) {
			struct ip6_flowlabel *fl1 = NULL;

			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(freq.flr_label);
			if (fl1) {
				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;
				write_lock_bh(&ip6_sk_fl_lock);
				sfl1->fl = fl1;
				sfl1->next = np->ipv6_fl_list;
				np->ipv6_fl_list = sfl1;
				write_unlock_bh(&ip6_sk_fl_lock);
				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;

		err = fl_intern(fl, freq.flr_label);
		if (err)
			goto done;

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

		sfl1->fl = fl;
		sfl1->next = np->ipv6_fl_list;
		np->ipv6_fl_list = sfl1;
		return 0;

	default:
		return -EINVAL;
	}

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

#ifdef CONFIG_PROC_FS

struct ip6fl_iter_state {
	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);

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

	fl = fl->next;
	while (!fl) {
		if (++state->bucket <= FL_HASH_MASK)
			fl = fl_ht[state->bucket];
	}
	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)
{
	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)
{
	read_unlock_bh(&ip6_fl_lock);
}

static void ip6fl_fl_seq_show(struct seq_file *seq, struct ip6_flowlabel *fl)
{
	while(fl) {
		seq_printf(seq,
			   "%05X %-1d %-6d %-6d %-6ld %-8ld "
			   "%02x%02x%02x%02x%02x%02x%02x%02x "
			   "%-4d\n",
			   (unsigned)ntohl(fl->label),
			   fl->share,
			   (unsigned)fl->owner,
			   atomic_read(&fl->users),
			   fl->linger/HZ,
			   (long)(fl->expires - jiffies)/HZ,
			   NIP6(fl->dst),
			   fl->opt ? fl->opt->opt_nflen : 0);
		fl = fl->next;
	}
}

static int ip6fl_seq_show(struct seq_file *seq, void *v)
{
	if (v == SEQ_START_TOKEN)
		seq_puts(seq, "Label S Owner  Users  Linger Expires  "
			      "Dst                              Opt\n");
	else
		ip6fl_fl_seq_show(seq, v);
	return 0;
}

static 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)
{
	struct seq_file *seq;
	int rc = -ENOMEM;
	struct ip6fl_iter_state *s = kmalloc(sizeof(*s), GFP_KERNEL);

	if (!s)
		goto out;

	rc = seq_open(file, &ip6fl_seq_ops);
	if (rc)
		goto out_kfree;

	seq = file->private_data;
	seq->private = s;
	memset(s, 0, sizeof(*s));
out:
	return rc;
out_kfree:
	kfree(s);
	goto out;
}

static struct file_operations ip6fl_seq_fops = {
	.owner		=	THIS_MODULE,
	.open		=	ip6fl_seq_open,
	.read		=	seq_read,
	.llseek		=	seq_lseek,
	.release	=	seq_release_private,
};
#endif


void ip6_flowlabel_init(void)
{
#ifdef CONFIG_PROC_FS
	proc_net_fops_create("ip6_flowlabel", S_IRUGO, &ip6fl_seq_fops);
#endif
}

void ip6_flowlabel_cleanup(void)
{
	del_timer(&ip6_fl_gc_timer);
#ifdef CONFIG_PROC_FS
	proc_net_remove("ip6_flowlabel");
#endif
}
Commit	Line	Data
1da177e4 LT	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/config.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/sock.h>
	25
	26	#include <net/ipv6.h>
	27	#include <net/ndisc.h>
	28	#include <net/protocol.h>
	29	#include <net/ip6_route.h>
	30	#include <net/addrconf.h>
	31	#include <net/rawv6.h>
	32	#include <net/icmp.h>
	33	#include <net/transp_v6.h>
	34
	35	#include <asm/uaccess.h>
	36
	37	#define FL_MIN_LINGER 6 /* Minimal linger. It is set to 6sec specified
	38	in old IPv6 RFC. Well, it was reasonable value.
	39	*/
	40	#define FL_MAX_LINGER 60 /* Maximal linger timeout */
	41
	42	/* FL hash table */
	43
	44	#define FL_MAX_PER_SOCK 32
	45	#define FL_MAX_SIZE 4096
	46	#define FL_HASH_MASK 255
	47	#define FL_HASH(l) (ntohl(l)&FL_HASH_MASK)
	48
	49	static atomic_t fl_size = ATOMIC_INIT(0);
	50	static struct ip6_flowlabel *fl_ht[FL_HASH_MASK+1];
	51
	52	static void ip6_fl_gc(unsigned long dummy);
8d06afab	53	static DEFINE_TIMER(ip6_fl_gc_timer, ip6_fl_gc, 0, 0);
1da177e4 LT	54
	55	/* FL hash table lock: it protects only of GC */
	56
	57	static DEFINE_RWLOCK(ip6_fl_lock);
	58
	59	/* Big socket sock */
	60
	61	static DEFINE_RWLOCK(ip6_sk_fl_lock);
	62
	63
	64	static __inline__ struct ip6_flowlabel * __fl_lookup(u32 label)
	65	{
	66	struct ip6_flowlabel *fl;
	67
	68	for (fl=fl_ht[FL_HASH(label)]; fl; fl = fl->next) {
	69	if (fl->label == label)
	70	return fl;
	71	}
	72	return NULL;
	73	}
	74
	75	static struct ip6_flowlabel * fl_lookup(u32 label)
	76	{
	77	struct ip6_flowlabel *fl;
	78
	79	read_lock_bh(&ip6_fl_lock);
	80	fl = __fl_lookup(label);
	81	if (fl)
	82	atomic_inc(&fl->users);
	83	read_unlock_bh(&ip6_fl_lock);
	84	return fl;
	85	}
	86
	87
	88	static void fl_free(struct ip6_flowlabel *fl)
	89	{
	90	if (fl)
	91	kfree(fl->opt);
	92	kfree(fl);
	93	}
	94
	95	static void fl_release(struct ip6_flowlabel *fl)
	96	{
	97	write_lock_bh(&ip6_fl_lock);
	98
	99	fl->lastuse = jiffies;
	100	if (atomic_dec_and_test(&fl->users)) {
	101	unsigned long ttd = fl->lastuse + fl->linger;
	102	if (time_after(ttd, fl->expires))
	103	fl->expires = ttd;
	104	ttd = fl->expires;
	105	if (fl->opt && fl->share == IPV6_FL_S_EXCL) {
	106	struct ipv6_txoptions *opt = fl->opt;
	107	fl->opt = NULL;
	108	kfree(opt);
	109	}
	110	if (!timer_pending(&ip6_fl_gc_timer) \|\|
	111	time_after(ip6_fl_gc_timer.expires, ttd))
	112	mod_timer(&ip6_fl_gc_timer, ttd);
	113	}
	114
	115	write_unlock_bh(&ip6_fl_lock);
	116	}
	117
118	static void ip6_fl_gc(unsigned long dummy)
119	{
120	int i;
121	unsigned long now = jiffies;
122	unsigned long sched = 0;
123
124	write_lock(&ip6_fl_lock);
125
126	for (i=0; i<=FL_HASH_MASK; i++) {
127	struct ip6_flowlabel fl, *flp;
128	flp = &fl_ht[i];
129	while ((fl=*flp) != NULL) {
130	if (atomic_read(&fl->users) == 0) {
131	unsigned long ttd = fl->lastuse + fl->linger;
132	if (time_after(ttd, fl->expires))
133	fl->expires = ttd;
134	ttd = fl->expires;
135	if (time_after_eq(now, ttd)) {
136	*flp = fl->next;
137	fl_free(fl);
138	atomic_dec(&fl_size);
139	continue;
140	}
141	if (!sched \|\| time_before(ttd, sched))
142	sched = ttd;
143	}
144	flp = &fl->next;
145	}
146	}
147	if (!sched && atomic_read(&fl_size))
148	sched = now + FL_MAX_LINGER;
149	if (sched) {
150	ip6_fl_gc_timer.expires = sched;
151	add_timer(&ip6_fl_gc_timer);
152	}
153	write_unlock(&ip6_fl_lock);
154	}
155
156	static int fl_intern(struct ip6_flowlabel *fl, __u32 label)
157	{
158	fl->label = label & IPV6_FLOWLABEL_MASK;
159
160	write_lock_bh(&ip6_fl_lock);
161	if (label == 0) {
162	for (;;) {
163	fl->label = htonl(net_random())&IPV6_FLOWLABEL_MASK;
164	if (fl->label) {
165	struct ip6_flowlabel *lfl;
166	lfl = __fl_lookup(fl->label);
167	if (lfl == NULL)
168	break;
169	}
170	}
171	}
172
173	fl->lastuse = jiffies;
174	fl->next = fl_ht[FL_HASH(fl->label)];
175	fl_ht[FL_HASH(fl->label)] = fl;
176	atomic_inc(&fl_size);
177	write_unlock_bh(&ip6_fl_lock);
178	return 0;
179	}
180
181
182
183	/* Socket flowlabel lists */
184
185	struct ip6_flowlabel * fl6_sock_lookup(struct sock *sk, u32 label)
186	{
187	struct ipv6_fl_socklist *sfl;
188	struct ipv6_pinfo *np = inet6_sk(sk);
189
190	label &= IPV6_FLOWLABEL_MASK;
191
192	for (sfl=np->ipv6_fl_list; sfl; sfl = sfl->next) {
193	struct ip6_flowlabel *fl = sfl->fl;
194	if (fl->label == label) {
195	fl->lastuse = jiffies;
196	atomic_inc(&fl->users);
197	return fl;
198	}
199	}
200	return NULL;
201	}
202
3cf3dc6c ACM	203	EXPORT_SYMBOL_GPL(fl6_sock_lookup);
3cf3dc6c ACM	204
1da177e4 LT	205	void fl6_free_socklist(struct sock *sk)
	206	{
	207	struct ipv6_pinfo *np = inet6_sk(sk);
	208	struct ipv6_fl_socklist *sfl;
	209
	210	while ((sfl = np->ipv6_fl_list) != NULL) {
	211	np->ipv6_fl_list = sfl->next;
	212	fl_release(sfl->fl);
	213	kfree(sfl);
	214	}
	215	}
	216
	217	/* Service routines */
	218
	219
	220	/*
	221	It is the only difficult place. flowlabel enforces equal headers
	222	before and including routing header, however user may supply options
	223	following rthdr.
	224	*/
	225
	226	struct ipv6_txoptions fl6_merge_options(struct ipv6_txoptions opt_space,
	227	struct ip6_flowlabel * fl,
	228	struct ipv6_txoptions * fopt)
	229	{
df9890c3 YH	230	struct ipv6_txoptions * fl_opt = fl->opt;
	231
	232	if (fopt == NULL \|\| fopt->opt_flen == 0)
	233	return fl_opt;
	234
1da177e4 LT	235	if (fl_opt != NULL) {
1da177e4 LT	236	opt_space->hopopt = fl_opt->hopopt;
df9890c3	237	opt_space->dst0opt = fl_opt->dst0opt;
1da177e4 LT	238	opt_space->srcrt = fl_opt->srcrt;
	239	opt_space->opt_nflen = fl_opt->opt_nflen;
	240	} else {
	241	if (fopt->opt_nflen == 0)
	242	return fopt;
	243	opt_space->hopopt = NULL;
	244	opt_space->dst0opt = NULL;
	245	opt_space->srcrt = NULL;
	246	opt_space->opt_nflen = 0;
	247	}
	248	opt_space->dst1opt = fopt->dst1opt;
1da177e4 LT	249	opt_space->opt_flen = fopt->opt_flen;
	250	return opt_space;
	251	}
	252
	253	static unsigned long check_linger(unsigned long ttl)
	254	{
	255	if (ttl < FL_MIN_LINGER)
	256	return FL_MIN_LINGER*HZ;
	257	if (ttl > FL_MAX_LINGER && !capable(CAP_NET_ADMIN))
	258	return 0;
	259	return ttl*HZ;
	260	}
	261
	262	static int fl6_renew(struct ip6_flowlabel *fl, unsigned long linger, unsigned long expires)
	263	{
	264	linger = check_linger(linger);
	265	if (!linger)
	266	return -EPERM;
	267	expires = check_linger(expires);
	268	if (!expires)
	269	return -EPERM;
	270	fl->lastuse = jiffies;
	271	if (time_before(fl->linger, linger))
	272	fl->linger = linger;
	273	if (time_before(expires, fl->linger))
	274	expires = fl->linger;
	275	if (time_before(fl->expires, fl->lastuse + expires))
	276	fl->expires = fl->lastuse + expires;
	277	return 0;
	278	}
	279
	280	static struct ip6_flowlabel *
	281	fl_create(struct in6_flowlabel_req freq, char __user optval, int optlen, int *err_p)
	282	{
	283	struct ip6_flowlabel *fl;
	284	int olen;
	285	int addr_type;
	286	int err;
	287
	288	err = -ENOMEM;
	289	fl = kmalloc(sizeof(*fl), GFP_KERNEL);
	290	if (fl == NULL)
	291	goto done;
	292	memset(fl, 0, sizeof(*fl));
	293
	294	olen = optlen - CMSG_ALIGN(sizeof(*freq));
	295	if (olen > 0) {
	296	struct msghdr msg;
	297	struct flowi flowi;
	298	int junk;
	299
	300	err = -ENOMEM;
	301	fl->opt = kmalloc(sizeof(*fl->opt) + olen, GFP_KERNEL);
	302	if (fl->opt == NULL)
	303	goto done;
	304
	305	memset(fl->opt, 0, sizeof(*fl->opt));
	306	fl->opt->tot_len = sizeof(*fl->opt) + olen;
	307	err = -EFAULT;
	308	if (copy_from_user(fl->opt+1, optval+CMSG_ALIGN(sizeof(*freq)), olen))
	309	goto done;
	310
	311	msg.msg_controllen = olen;
	312	msg.msg_control = (void*)(fl->opt+1);
313	flowi.oif = 0;
314
41a1f8ea	315	err = datagram_send_ctl(&msg, &flowi, fl->opt, &junk, &junk);
1da177e4 LT	316	if (err)
	317	goto done;
	318	err = -EINVAL;
	319	if (fl->opt->opt_flen)
	320	goto done;
	321	if (fl->opt->opt_nflen == 0) {
	322	kfree(fl->opt);
	323	fl->opt = NULL;
	324	}
	325	}
	326
	327	fl->expires = jiffies;
	328	err = fl6_renew(fl, freq->flr_linger, freq->flr_expires);
	329	if (err)
	330	goto done;
	331	fl->share = freq->flr_share;
	332	addr_type = ipv6_addr_type(&freq->flr_dst);
	333	if ((addr_type&IPV6_ADDR_MAPPED)
	334	\|\| addr_type == IPV6_ADDR_ANY)
	335	goto done;
	336	ipv6_addr_copy(&fl->dst, &freq->flr_dst);
	337	atomic_set(&fl->users, 1);
	338	switch (fl->share) {
	339	case IPV6_FL_S_EXCL:
	340	case IPV6_FL_S_ANY:
	341	break;
	342	case IPV6_FL_S_PROCESS:
	343	fl->owner = current->pid;
	344	break;
	345	case IPV6_FL_S_USER:
	346	fl->owner = current->euid;
	347	break;
	348	default:
	349	err = -EINVAL;
	350	goto done;
	351	}
	352	return fl;
	353
	354	done:
	355	fl_free(fl);
	356	*err_p = err;
	357	return NULL;
	358	}
	359
	360	static int mem_check(struct sock *sk)
	361	{
	362	struct ipv6_pinfo *np = inet6_sk(sk);
	363	struct ipv6_fl_socklist *sfl;
	364	int room = FL_MAX_SIZE - atomic_read(&fl_size);
	365	int count = 0;
	366
	367	if (room > FL_MAX_SIZE - FL_MAX_PER_SOCK)
	368	return 0;
	369
	370	for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next)
	371	count++;
	372
	373	if (room <= 0 \|\|
	374	((count >= FL_MAX_PER_SOCK \|\|
	375	(count > 0 && room < FL_MAX_SIZE/2) \|\| room < FL_MAX_SIZE/4)
	376	&& !capable(CAP_NET_ADMIN)))
	377	return -ENOBUFS;
	378
	379	return 0;
380	}
381
382	static int ipv6_hdr_cmp(struct ipv6_opt_hdr h1, struct ipv6_opt_hdr h2)
383	{
384	if (h1 == h2)
385	return 0;
386	if (h1 == NULL \|\| h2 == NULL)
387	return 1;
388	if (h1->hdrlen != h2->hdrlen)
389	return 1;
390	return memcmp(h1+1, h2+1, ((h1->hdrlen+1)<<3) - sizeof(*h1));
391	}
392
393	static int ipv6_opt_cmp(struct ipv6_txoptions o1, struct ipv6_txoptions o2)
394	{
395	if (o1 == o2)
396	return 0;
397	if (o1 == NULL \|\| o2 == NULL)
398	return 1;
399	if (o1->opt_nflen != o2->opt_nflen)
400	return 1;
401	if (ipv6_hdr_cmp(o1->hopopt, o2->hopopt))
402	return 1;
403	if (ipv6_hdr_cmp(o1->dst0opt, o2->dst0opt))
404	return 1;
405	if (ipv6_hdr_cmp((struct ipv6_opt_hdr )o1->srcrt, (struct ipv6_opt_hdr )o2->srcrt))
406	return 1;
407	return 0;
408	}
409
410	int ipv6_flowlabel_opt(struct sock sk, char __user optval, int optlen)
411	{
412	int err;
413	struct ipv6_pinfo *np = inet6_sk(sk);
414	struct in6_flowlabel_req freq;
415	struct ipv6_fl_socklist *sfl1=NULL;
416	struct ipv6_fl_socklist sfl, *sflp;
417	struct ip6_flowlabel *fl;
418
419	if (optlen < sizeof(freq))
420	return -EINVAL;
421
422	if (copy_from_user(&freq, optval, sizeof(freq)))
423	return -EFAULT;
424
425	switch (freq.flr_action) {
426	case IPV6_FL_A_PUT:
427	write_lock_bh(&ip6_sk_fl_lock);
428	for (sflp = &np->ipv6_fl_list; (sfl=*sflp)!=NULL; sflp = &sfl->next) {
429	if (sfl->fl->label == freq.flr_label) {
430	if (freq.flr_label == (np->flow_label&IPV6_FLOWLABEL_MASK))
431	np->flow_label &= ~IPV6_FLOWLABEL_MASK;
432	*sflp = sfl->next;
433	write_unlock_bh(&ip6_sk_fl_lock);
434	fl_release(sfl->fl);
435	kfree(sfl);
436	return 0;
437	}
438	}
439	write_unlock_bh(&ip6_sk_fl_lock);
440	return -ESRCH;
441
442	case IPV6_FL_A_RENEW:
443	read_lock_bh(&ip6_sk_fl_lock);
444	for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next) {
445	if (sfl->fl->label == freq.flr_label) {
446	err = fl6_renew(sfl->fl, freq.flr_linger, freq.flr_expires);
447	read_unlock_bh(&ip6_sk_fl_lock);
448	return err;
449	}
450	}
451	read_unlock_bh(&ip6_sk_fl_lock);
452
453	if (freq.flr_share == IPV6_FL_S_NONE && capable(CAP_NET_ADMIN)) {
454	fl = fl_lookup(freq.flr_label);
455	if (fl) {
456	err = fl6_renew(fl, freq.flr_linger, freq.flr_expires);
457	fl_release(fl);
458	return err;
459	}
460	}
461	return -ESRCH;
462
463	case IPV6_FL_A_GET:
464	if (freq.flr_label & ~IPV6_FLOWLABEL_MASK)
465	return -EINVAL;
466
467	fl = fl_create(&freq, optval, optlen, &err);
468	if (fl == NULL)
469	return err;
470	sfl1 = kmalloc(sizeof(*sfl1), GFP_KERNEL);
471
472	if (freq.flr_label) {
473	struct ip6_flowlabel *fl1 = NULL;
474
475	err = -EEXIST;
476	read_lock_bh(&ip6_sk_fl_lock);
477	for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next) {
478	if (sfl->fl->label == freq.flr_label) {
479	if (freq.flr_flags&IPV6_FL_F_EXCL) {
480	read_unlock_bh(&ip6_sk_fl_lock);
481	goto done;
482	}
483	fl1 = sfl->fl;
4ea6a804	484	atomic_inc(&fl1->users);
1da177e4 LT	485	break;
	486	}
	487	}
	488	read_unlock_bh(&ip6_sk_fl_lock);
	489
	490	if (fl1 == NULL)
	491	fl1 = fl_lookup(freq.flr_label);
	492	if (fl1) {
	493	err = -EEXIST;
	494	if (freq.flr_flags&IPV6_FL_F_EXCL)
	495	goto release;
	496	err = -EPERM;
	497	if (fl1->share == IPV6_FL_S_EXCL \|\|
	498	fl1->share != fl->share \|\|
	499	fl1->owner != fl->owner)
	500	goto release;
	501
	502	err = -EINVAL;
	503	if (!ipv6_addr_equal(&fl1->dst, &fl->dst) \|\|
	504	ipv6_opt_cmp(fl1->opt, fl->opt))
	505	goto release;
	506
	507	err = -ENOMEM;
	508	if (sfl1 == NULL)
	509	goto release;
	510	if (fl->linger > fl1->linger)
	511	fl1->linger = fl->linger;
	512	if ((long)(fl->expires - fl1->expires) > 0)
	513	fl1->expires = fl->expires;
	514	write_lock_bh(&ip6_sk_fl_lock);
	515	sfl1->fl = fl1;
	516	sfl1->next = np->ipv6_fl_list;
	517	np->ipv6_fl_list = sfl1;
	518	write_unlock_bh(&ip6_sk_fl_lock);
	519	fl_free(fl);
	520	return 0;
	521
	522	release:
	523	fl_release(fl1);
	524	goto done;
	525	}
	526	}
	527	err = -ENOENT;
	528	if (!(freq.flr_flags&IPV6_FL_F_CREATE))
	529	goto done;
	530
	531	err = -ENOMEM;
	532	if (sfl1 == NULL \|\| (err = mem_check(sk)) != 0)
	533	goto done;
	534
	535	err = fl_intern(fl, freq.flr_label);
	536	if (err)
	537	goto done;
	538
6c94d361 DM	539	if (!freq.flr_label) {
	540	if (copy_to_user(&((struct in6_flowlabel_req __user *) optval)->flr_label,
	541	&fl->label, sizeof(fl->label))) {
	542	/* Intentionally ignore fault. */
	543	}
	544	}
1da177e4 LT	545
	546	sfl1->fl = fl;
	547	sfl1->next = np->ipv6_fl_list;
	548	np->ipv6_fl_list = sfl1;
	549	return 0;
	550
	551	default:
	552	return -EINVAL;
	553	}
	554
	555	done:
	556	fl_free(fl);
	557	kfree(sfl1);
	558	return err;
	559	}
	560
	561	#ifdef CONFIG_PROC_FS
	562
	563	struct ip6fl_iter_state {
	564	int bucket;
	565	};
	566
	567	#define ip6fl_seq_private(seq) ((struct ip6fl_iter_state *)(seq)->private)
	568
	569	static struct ip6_flowlabel ip6fl_get_first(struct seq_file seq)
	570	{
	571	struct ip6_flowlabel *fl = NULL;
	572	struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
	573
	574	for (state->bucket = 0; state->bucket <= FL_HASH_MASK; ++state->bucket) {
	575	if (fl_ht[state->bucket]) {
	576	fl = fl_ht[state->bucket];
	577	break;
	578	}
	579	}
	580	return fl;
	581	}
	582
	583	static struct ip6_flowlabel ip6fl_get_next(struct seq_file seq, struct ip6_flowlabel *fl)
	584	{
	585	struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
	586
	587	fl = fl->next;
	588	while (!fl) {
	589	if (++state->bucket <= FL_HASH_MASK)
	590	fl = fl_ht[state->bucket];
	591	}
	592	return fl;
	593	}
	594
	595	static struct ip6_flowlabel ip6fl_get_idx(struct seq_file seq, loff_t pos)
	596	{
	597	struct ip6_flowlabel *fl = ip6fl_get_first(seq);
	598	if (fl)
	599	while (pos && (fl = ip6fl_get_next(seq, fl)) != NULL)
	600	--pos;
	601	return pos ? NULL : fl;
	602	}
	603
	604	static void ip6fl_seq_start(struct seq_file seq, loff_t *pos)
	605	{
	606	read_lock_bh(&ip6_fl_lock);
	607	return pos ? ip6fl_get_idx(seq, pos - 1) : SEQ_START_TOKEN;
	608	}
609
610	static void ip6fl_seq_next(struct seq_file seq, void v, loff_t pos)
611	{
612	struct ip6_flowlabel *fl;
613
614	if (v == SEQ_START_TOKEN)
615	fl = ip6fl_get_first(seq);
616	else
617	fl = ip6fl_get_next(seq, v);
618	++*pos;
619	return fl;
620	}
621
622	static void ip6fl_seq_stop(struct seq_file seq, void v)
623	{
624	read_unlock_bh(&ip6_fl_lock);
625	}
626
627	static void ip6fl_fl_seq_show(struct seq_file seq, struct ip6_flowlabel fl)
628	{
629	while(fl) {
630	seq_printf(seq,
631	"%05X %-1d %-6d %-6d %-6ld %-8ld "
632	"%02x%02x%02x%02x%02x%02x%02x%02x "
633	"%-4d\n",
634	(unsigned)ntohl(fl->label),
635	fl->share,
636	(unsigned)fl->owner,
637	atomic_read(&fl->users),
638	fl->linger/HZ,
639	(long)(fl->expires - jiffies)/HZ,
640	NIP6(fl->dst),
641	fl->opt ? fl->opt->opt_nflen : 0);
642	fl = fl->next;
643	}
644	}
645
646	static int ip6fl_seq_show(struct seq_file seq, void v)
647	{
648	if (v == SEQ_START_TOKEN)
649	seq_puts(seq, "Label S Owner Users Linger Expires "
650	"Dst Opt\n");
651	else
652	ip6fl_fl_seq_show(seq, v);
653	return 0;
654	}
655
656	static struct seq_operations ip6fl_seq_ops = {
657	.start = ip6fl_seq_start,
658	.next = ip6fl_seq_next,
659	.stop = ip6fl_seq_stop,
660	.show = ip6fl_seq_show,
661	};
662
663	static int ip6fl_seq_open(struct inode inode, struct file file)
664	{
665	struct seq_file *seq;
666	int rc = -ENOMEM;
667	struct ip6fl_iter_state s = kmalloc(sizeof(s), GFP_KERNEL);
668
669	if (!s)
670	goto out;
671
672	rc = seq_open(file, &ip6fl_seq_ops);
673	if (rc)
674	goto out_kfree;
675
676	seq = file->private_data;
677	seq->private = s;
678	memset(s, 0, sizeof(*s));
679	out:
680	return rc;
681	out_kfree:
682	kfree(s);
683	goto out;
684	}
685
686	static struct file_operations ip6fl_seq_fops = {
687	.owner = THIS_MODULE,
688	.open = ip6fl_seq_open,
689	.read = seq_read,
690	.llseek = seq_lseek,
691	.release = seq_release_private,
692	};
693	#endif
694
695
696	void ip6_flowlabel_init(void)
697	{
698	#ifdef CONFIG_PROC_FS
699	proc_net_fops_create("ip6_flowlabel", S_IRUGO, &ip6fl_seq_fops);
700	#endif
701	}
702
703	void ip6_flowlabel_cleanup(void)
704	{
705	del_timer(&ip6_fl_gc_timer);
706	#ifdef CONFIG_PROC_FS
707	proc_net_remove("ip6_flowlabel");
708	#endif
709	}