[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/capability.h>
#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 " NIP6_SEQFMT " %-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_printf(seq, "%-5s %-1s %-6s %-6s %-6s %-8s %-32s %s\n",
			   "Label", "S", "Owner", "Users", "Linger", "Expires", "Dst", "Opt");
	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
4fc268d2	12	#include <linux/capability.h>
1da177e4 LT	13	#include <linux/config.h>
	14	#include <linux/errno.h>
	15	#include <linux/types.h>
	16	#include <linux/socket.h>
	17	#include <linux/net.h>
	18	#include <linux/netdevice.h>
	19	#include <linux/if_arp.h>
	20	#include <linux/in6.h>
	21	#include <linux/route.h>
	22	#include <linux/proc_fs.h>
	23	#include <linux/seq_file.h>
	24
	25	#include <net/sock.h>
	26
	27	#include <net/ipv6.h>
	28	#include <net/ndisc.h>
	29	#include <net/protocol.h>
	30	#include <net/ip6_route.h>
	31	#include <net/addrconf.h>
	32	#include <net/rawv6.h>
	33	#include <net/icmp.h>
	34	#include <net/transp_v6.h>
	35
	36	#include <asm/uaccess.h>
	37
	38	#define FL_MIN_LINGER 6 /* Minimal linger. It is set to 6sec specified
	39	in old IPv6 RFC. Well, it was reasonable value.
	40	*/
	41	#define FL_MAX_LINGER 60 /* Maximal linger timeout */
	42
	43	/* FL hash table */
	44
	45	#define FL_MAX_PER_SOCK 32
	46	#define FL_MAX_SIZE 4096
	47	#define FL_HASH_MASK 255
	48	#define FL_HASH(l) (ntohl(l)&FL_HASH_MASK)
	49
	50	static atomic_t fl_size = ATOMIC_INIT(0);
	51	static struct ip6_flowlabel *fl_ht[FL_HASH_MASK+1];
	52
	53	static void ip6_fl_gc(unsigned long dummy);
8d06afab	54	static DEFINE_TIMER(ip6_fl_gc_timer, ip6_fl_gc, 0, 0);
1da177e4 LT	55
	56	/* FL hash table lock: it protects only of GC */
	57
	58	static DEFINE_RWLOCK(ip6_fl_lock);
	59
	60	/* Big socket sock */
	61
	62	static DEFINE_RWLOCK(ip6_sk_fl_lock);
	63
	64
	65	static __inline__ struct ip6_flowlabel * __fl_lookup(u32 label)
	66	{
	67	struct ip6_flowlabel *fl;
	68
	69	for (fl=fl_ht[FL_HASH(label)]; fl; fl = fl->next) {
	70	if (fl->label == label)
	71	return fl;
	72	}
	73	return NULL;
	74	}
	75
	76	static struct ip6_flowlabel * fl_lookup(u32 label)
	77	{
	78	struct ip6_flowlabel *fl;
	79
	80	read_lock_bh(&ip6_fl_lock);
	81	fl = __fl_lookup(label);
	82	if (fl)
	83	atomic_inc(&fl->users);
	84	read_unlock_bh(&ip6_fl_lock);
	85	return fl;
	86	}
	87
	88
	89	static void fl_free(struct ip6_flowlabel *fl)
	90	{
	91	if (fl)
	92	kfree(fl->opt);
	93	kfree(fl);
	94	}
	95
	96	static void fl_release(struct ip6_flowlabel *fl)
	97	{
	98	write_lock_bh(&ip6_fl_lock);
	99
	100	fl->lastuse = jiffies;
	101	if (atomic_dec_and_test(&fl->users)) {
	102	unsigned long ttd = fl->lastuse + fl->linger;
	103	if (time_after(ttd, fl->expires))
	104	fl->expires = ttd;
	105	ttd = fl->expires;
	106	if (fl->opt && fl->share == IPV6_FL_S_EXCL) {
	107	struct ipv6_txoptions *opt = fl->opt;
	108	fl->opt = NULL;
	109	kfree(opt);
	110	}
	111	if (!timer_pending(&ip6_fl_gc_timer) \|\|
	112	time_after(ip6_fl_gc_timer.expires, ttd))
	113	mod_timer(&ip6_fl_gc_timer, ttd);
	114	}
	115
	116	write_unlock_bh(&ip6_fl_lock);
	117	}
	118
119	static void ip6_fl_gc(unsigned long dummy)
120	{
121	int i;
122	unsigned long now = jiffies;
123	unsigned long sched = 0;
124
125	write_lock(&ip6_fl_lock);
126
127	for (i=0; i<=FL_HASH_MASK; i++) {
128	struct ip6_flowlabel fl, *flp;
129	flp = &fl_ht[i];
130	while ((fl=*flp) != NULL) {
131	if (atomic_read(&fl->users) == 0) {
132	unsigned long ttd = fl->lastuse + fl->linger;
133	if (time_after(ttd, fl->expires))
134	fl->expires = ttd;
135	ttd = fl->expires;
136	if (time_after_eq(now, ttd)) {
137	*flp = fl->next;
138	fl_free(fl);
139	atomic_dec(&fl_size);
140	continue;
141	}
142	if (!sched \|\| time_before(ttd, sched))
143	sched = ttd;
144	}
145	flp = &fl->next;
146	}
147	}
148	if (!sched && atomic_read(&fl_size))
149	sched = now + FL_MAX_LINGER;
150	if (sched) {
151	ip6_fl_gc_timer.expires = sched;
152	add_timer(&ip6_fl_gc_timer);
153	}
154	write_unlock(&ip6_fl_lock);
155	}
156
157	static int fl_intern(struct ip6_flowlabel *fl, __u32 label)
158	{
159	fl->label = label & IPV6_FLOWLABEL_MASK;
160
161	write_lock_bh(&ip6_fl_lock);
162	if (label == 0) {
163	for (;;) {
164	fl->label = htonl(net_random())&IPV6_FLOWLABEL_MASK;
165	if (fl->label) {
166	struct ip6_flowlabel *lfl;
167	lfl = __fl_lookup(fl->label);
168	if (lfl == NULL)
169	break;
170	}
171	}
172	}
173
174	fl->lastuse = jiffies;
175	fl->next = fl_ht[FL_HASH(fl->label)];
176	fl_ht[FL_HASH(fl->label)] = fl;
177	atomic_inc(&fl_size);
178	write_unlock_bh(&ip6_fl_lock);
179	return 0;
180	}
181
182
183
184	/* Socket flowlabel lists */
185
186	struct ip6_flowlabel * fl6_sock_lookup(struct sock *sk, u32 label)
187	{
188	struct ipv6_fl_socklist *sfl;
189	struct ipv6_pinfo *np = inet6_sk(sk);
190
191	label &= IPV6_FLOWLABEL_MASK;
192
193	for (sfl=np->ipv6_fl_list; sfl; sfl = sfl->next) {
194	struct ip6_flowlabel *fl = sfl->fl;
195	if (fl->label == label) {
196	fl->lastuse = jiffies;
197	atomic_inc(&fl->users);
198	return fl;
199	}
200	}
201	return NULL;
202	}
203
3cf3dc6c ACM	204	EXPORT_SYMBOL_GPL(fl6_sock_lookup);
3cf3dc6c ACM	205
1da177e4 LT	206	void fl6_free_socklist(struct sock *sk)
	207	{
	208	struct ipv6_pinfo *np = inet6_sk(sk);
	209	struct ipv6_fl_socklist *sfl;
	210
	211	while ((sfl = np->ipv6_fl_list) != NULL) {
	212	np->ipv6_fl_list = sfl->next;
	213	fl_release(sfl->fl);
	214	kfree(sfl);
	215	}
	216	}
	217
	218	/* Service routines */
	219
	220
	221	/*
	222	It is the only difficult place. flowlabel enforces equal headers
	223	before and including routing header, however user may supply options
	224	following rthdr.
	225	*/
	226
	227	struct ipv6_txoptions fl6_merge_options(struct ipv6_txoptions opt_space,
	228	struct ip6_flowlabel * fl,
	229	struct ipv6_txoptions * fopt)
	230	{
df9890c3 YH	231	struct ipv6_txoptions * fl_opt = fl->opt;
	232
	233	if (fopt == NULL \|\| fopt->opt_flen == 0)
	234	return fl_opt;
	235
1da177e4 LT	236	if (fl_opt != NULL) {
1da177e4 LT	237	opt_space->hopopt = fl_opt->hopopt;
df9890c3	238	opt_space->dst0opt = fl_opt->dst0opt;
1da177e4 LT	239	opt_space->srcrt = fl_opt->srcrt;
	240	opt_space->opt_nflen = fl_opt->opt_nflen;
	241	} else {
	242	if (fopt->opt_nflen == 0)
	243	return fopt;
	244	opt_space->hopopt = NULL;
	245	opt_space->dst0opt = NULL;
	246	opt_space->srcrt = NULL;
	247	opt_space->opt_nflen = 0;
	248	}
	249	opt_space->dst1opt = fopt->dst1opt;
1da177e4 LT	250	opt_space->opt_flen = fopt->opt_flen;
	251	return opt_space;
	252	}
	253
	254	static unsigned long check_linger(unsigned long ttl)
	255	{
	256	if (ttl < FL_MIN_LINGER)
	257	return FL_MIN_LINGER*HZ;
	258	if (ttl > FL_MAX_LINGER && !capable(CAP_NET_ADMIN))
	259	return 0;
	260	return ttl*HZ;
	261	}
	262
	263	static int fl6_renew(struct ip6_flowlabel *fl, unsigned long linger, unsigned long expires)
	264	{
	265	linger = check_linger(linger);
	266	if (!linger)
	267	return -EPERM;
	268	expires = check_linger(expires);
	269	if (!expires)
	270	return -EPERM;
	271	fl->lastuse = jiffies;
	272	if (time_before(fl->linger, linger))
	273	fl->linger = linger;
	274	if (time_before(expires, fl->linger))
	275	expires = fl->linger;
	276	if (time_before(fl->expires, fl->lastuse + expires))
	277	fl->expires = fl->lastuse + expires;
	278	return 0;
	279	}
	280
	281	static struct ip6_flowlabel *
	282	fl_create(struct in6_flowlabel_req freq, char __user optval, int optlen, int *err_p)
	283	{
	284	struct ip6_flowlabel *fl;
	285	int olen;
	286	int addr_type;
	287	int err;
	288
	289	err = -ENOMEM;
	290	fl = kmalloc(sizeof(*fl), GFP_KERNEL);
	291	if (fl == NULL)
	292	goto done;
	293	memset(fl, 0, sizeof(*fl));
	294
	295	olen = optlen - CMSG_ALIGN(sizeof(*freq));
	296	if (olen > 0) {
	297	struct msghdr msg;
	298	struct flowi flowi;
	299	int junk;
	300
	301	err = -ENOMEM;
	302	fl->opt = kmalloc(sizeof(*fl->opt) + olen, GFP_KERNEL);
	303	if (fl->opt == NULL)
	304	goto done;
	305
	306	memset(fl->opt, 0, sizeof(*fl->opt));
	307	fl->opt->tot_len = sizeof(*fl->opt) + olen;
	308	err = -EFAULT;
	309	if (copy_from_user(fl->opt+1, optval+CMSG_ALIGN(sizeof(*freq)), olen))
	310	goto done;
	311
	312	msg.msg_controllen = olen;
	313	msg.msg_control = (void*)(fl->opt+1);
314	flowi.oif = 0;
315
41a1f8ea	316	err = datagram_send_ctl(&msg, &flowi, fl->opt, &junk, &junk);
1da177e4 LT	317	if (err)
	318	goto done;
	319	err = -EINVAL;
	320	if (fl->opt->opt_flen)
	321	goto done;
	322	if (fl->opt->opt_nflen == 0) {
	323	kfree(fl->opt);
	324	fl->opt = NULL;
	325	}
	326	}
	327
	328	fl->expires = jiffies;
	329	err = fl6_renew(fl, freq->flr_linger, freq->flr_expires);
	330	if (err)
	331	goto done;
	332	fl->share = freq->flr_share;
	333	addr_type = ipv6_addr_type(&freq->flr_dst);
	334	if ((addr_type&IPV6_ADDR_MAPPED)
	335	\|\| addr_type == IPV6_ADDR_ANY)
	336	goto done;
	337	ipv6_addr_copy(&fl->dst, &freq->flr_dst);
	338	atomic_set(&fl->users, 1);
	339	switch (fl->share) {
	340	case IPV6_FL_S_EXCL:
	341	case IPV6_FL_S_ANY:
	342	break;
	343	case IPV6_FL_S_PROCESS:
	344	fl->owner = current->pid;
	345	break;
	346	case IPV6_FL_S_USER:
	347	fl->owner = current->euid;
	348	break;
	349	default:
	350	err = -EINVAL;
	351	goto done;
	352	}
	353	return fl;
	354
	355	done:
	356	fl_free(fl);
	357	*err_p = err;
	358	return NULL;
	359	}
	360
	361	static int mem_check(struct sock *sk)
	362	{
	363	struct ipv6_pinfo *np = inet6_sk(sk);
	364	struct ipv6_fl_socklist *sfl;
	365	int room = FL_MAX_SIZE - atomic_read(&fl_size);
	366	int count = 0;
	367
	368	if (room > FL_MAX_SIZE - FL_MAX_PER_SOCK)
	369	return 0;
	370
	371	for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next)
	372	count++;
	373
	374	if (room <= 0 \|\|
	375	((count >= FL_MAX_PER_SOCK \|\|
	376	(count > 0 && room < FL_MAX_SIZE/2) \|\| room < FL_MAX_SIZE/4)
	377	&& !capable(CAP_NET_ADMIN)))
	378	return -ENOBUFS;
	379
	380	return 0;
381	}
382
383	static int ipv6_hdr_cmp(struct ipv6_opt_hdr h1, struct ipv6_opt_hdr h2)
384	{
385	if (h1 == h2)
386	return 0;
387	if (h1 == NULL \|\| h2 == NULL)
388	return 1;
389	if (h1->hdrlen != h2->hdrlen)
390	return 1;
391	return memcmp(h1+1, h2+1, ((h1->hdrlen+1)<<3) - sizeof(*h1));
392	}
393
394	static int ipv6_opt_cmp(struct ipv6_txoptions o1, struct ipv6_txoptions o2)
395	{
396	if (o1 == o2)
397	return 0;
398	if (o1 == NULL \|\| o2 == NULL)
399	return 1;
400	if (o1->opt_nflen != o2->opt_nflen)
401	return 1;
402	if (ipv6_hdr_cmp(o1->hopopt, o2->hopopt))
403	return 1;
404	if (ipv6_hdr_cmp(o1->dst0opt, o2->dst0opt))
405	return 1;
406	if (ipv6_hdr_cmp((struct ipv6_opt_hdr )o1->srcrt, (struct ipv6_opt_hdr )o2->srcrt))
407	return 1;
408	return 0;
409	}
410
411	int ipv6_flowlabel_opt(struct sock sk, char __user optval, int optlen)
412	{
413	int err;
414	struct ipv6_pinfo *np = inet6_sk(sk);
415	struct in6_flowlabel_req freq;
416	struct ipv6_fl_socklist *sfl1=NULL;
417	struct ipv6_fl_socklist sfl, *sflp;
418	struct ip6_flowlabel *fl;
419
420	if (optlen < sizeof(freq))
421	return -EINVAL;
422
423	if (copy_from_user(&freq, optval, sizeof(freq)))
424	return -EFAULT;
425
426	switch (freq.flr_action) {
427	case IPV6_FL_A_PUT:
428	write_lock_bh(&ip6_sk_fl_lock);
429	for (sflp = &np->ipv6_fl_list; (sfl=*sflp)!=NULL; sflp = &sfl->next) {
430	if (sfl->fl->label == freq.flr_label) {
431	if (freq.flr_label == (np->flow_label&IPV6_FLOWLABEL_MASK))
432	np->flow_label &= ~IPV6_FLOWLABEL_MASK;
433	*sflp = sfl->next;
434	write_unlock_bh(&ip6_sk_fl_lock);
435	fl_release(sfl->fl);
436	kfree(sfl);
437	return 0;
438	}
439	}
440	write_unlock_bh(&ip6_sk_fl_lock);
441	return -ESRCH;
442
443	case IPV6_FL_A_RENEW:
444	read_lock_bh(&ip6_sk_fl_lock);
445	for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next) {
446	if (sfl->fl->label == freq.flr_label) {
447	err = fl6_renew(sfl->fl, freq.flr_linger, freq.flr_expires);
448	read_unlock_bh(&ip6_sk_fl_lock);
449	return err;
450	}
451	}
452	read_unlock_bh(&ip6_sk_fl_lock);
453
454	if (freq.flr_share == IPV6_FL_S_NONE && capable(CAP_NET_ADMIN)) {
455	fl = fl_lookup(freq.flr_label);
456	if (fl) {
457	err = fl6_renew(fl, freq.flr_linger, freq.flr_expires);
458	fl_release(fl);
459	return err;
460	}
461	}
462	return -ESRCH;
463
464	case IPV6_FL_A_GET:
465	if (freq.flr_label & ~IPV6_FLOWLABEL_MASK)
466	return -EINVAL;
467
468	fl = fl_create(&freq, optval, optlen, &err);
469	if (fl == NULL)
470	return err;
471	sfl1 = kmalloc(sizeof(*sfl1), GFP_KERNEL);
472
473	if (freq.flr_label) {
474	struct ip6_flowlabel *fl1 = NULL;
475
476	err = -EEXIST;
477	read_lock_bh(&ip6_sk_fl_lock);
478	for (sfl = np->ipv6_fl_list; sfl; sfl = sfl->next) {
479	if (sfl->fl->label == freq.flr_label) {
480	if (freq.flr_flags&IPV6_FL_F_EXCL) {
481	read_unlock_bh(&ip6_sk_fl_lock);
482	goto done;
483	}
484	fl1 = sfl->fl;
4ea6a804	485	atomic_inc(&fl1->users);
1da177e4 LT	486	break;
	487	}
	488	}
	489	read_unlock_bh(&ip6_sk_fl_lock);
	490
	491	if (fl1 == NULL)
	492	fl1 = fl_lookup(freq.flr_label);
	493	if (fl1) {
	494	err = -EEXIST;
	495	if (freq.flr_flags&IPV6_FL_F_EXCL)
	496	goto release;
	497	err = -EPERM;
	498	if (fl1->share == IPV6_FL_S_EXCL \|\|
	499	fl1->share != fl->share \|\|
	500	fl1->owner != fl->owner)
	501	goto release;
	502
	503	err = -EINVAL;
	504	if (!ipv6_addr_equal(&fl1->dst, &fl->dst) \|\|
	505	ipv6_opt_cmp(fl1->opt, fl->opt))
	506	goto release;
	507
	508	err = -ENOMEM;
	509	if (sfl1 == NULL)
	510	goto release;
	511	if (fl->linger > fl1->linger)
	512	fl1->linger = fl->linger;
	513	if ((long)(fl->expires - fl1->expires) > 0)
	514	fl1->expires = fl->expires;
	515	write_lock_bh(&ip6_sk_fl_lock);
	516	sfl1->fl = fl1;
	517	sfl1->next = np->ipv6_fl_list;
	518	np->ipv6_fl_list = sfl1;
	519	write_unlock_bh(&ip6_sk_fl_lock);
	520	fl_free(fl);
	521	return 0;
	522
	523	release:
	524	fl_release(fl1);
	525	goto done;
	526	}
	527	}
	528	err = -ENOENT;
	529	if (!(freq.flr_flags&IPV6_FL_F_CREATE))
	530	goto done;
	531
	532	err = -ENOMEM;
	533	if (sfl1 == NULL \|\| (err = mem_check(sk)) != 0)
	534	goto done;
	535
	536	err = fl_intern(fl, freq.flr_label);
	537	if (err)
	538	goto done;
	539
6c94d361 DM	540	if (!freq.flr_label) {
	541	if (copy_to_user(&((struct in6_flowlabel_req __user *) optval)->flr_label,
	542	&fl->label, sizeof(fl->label))) {
	543	/* Intentionally ignore fault. */
	544	}
	545	}
1da177e4 LT	546
	547	sfl1->fl = fl;
	548	sfl1->next = np->ipv6_fl_list;
	549	np->ipv6_fl_list = sfl1;
	550	return 0;
	551
	552	default:
	553	return -EINVAL;
	554	}
	555
	556	done:
	557	fl_free(fl);
	558	kfree(sfl1);
	559	return err;
	560	}
	561
	562	#ifdef CONFIG_PROC_FS
	563
	564	struct ip6fl_iter_state {
	565	int bucket;
	566	};
	567
	568	#define ip6fl_seq_private(seq) ((struct ip6fl_iter_state *)(seq)->private)
	569
	570	static struct ip6_flowlabel ip6fl_get_first(struct seq_file seq)
	571	{
	572	struct ip6_flowlabel *fl = NULL;
	573	struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
	574
	575	for (state->bucket = 0; state->bucket <= FL_HASH_MASK; ++state->bucket) {
	576	if (fl_ht[state->bucket]) {
	577	fl = fl_ht[state->bucket];
	578	break;
	579	}
	580	}
	581	return fl;
	582	}
	583
	584	static struct ip6_flowlabel ip6fl_get_next(struct seq_file seq, struct ip6_flowlabel *fl)
	585	{
	586	struct ip6fl_iter_state *state = ip6fl_seq_private(seq);
	587
	588	fl = fl->next;
	589	while (!fl) {
	590	if (++state->bucket <= FL_HASH_MASK)
	591	fl = fl_ht[state->bucket];
	592	}
	593	return fl;
	594	}
	595
	596	static struct ip6_flowlabel ip6fl_get_idx(struct seq_file seq, loff_t pos)
	597	{
	598	struct ip6_flowlabel *fl = ip6fl_get_first(seq);
	599	if (fl)
	600	while (pos && (fl = ip6fl_get_next(seq, fl)) != NULL)
	601	--pos;
	602	return pos ? NULL : fl;
	603	}
	604
	605	static void ip6fl_seq_start(struct seq_file seq, loff_t *pos)
	606	{
	607	read_lock_bh(&ip6_fl_lock);
	608	return pos ? ip6fl_get_idx(seq, pos - 1) : SEQ_START_TOKEN;
	609	}
610
611	static void ip6fl_seq_next(struct seq_file seq, void v, loff_t pos)
612	{
613	struct ip6_flowlabel *fl;
614
615	if (v == SEQ_START_TOKEN)
616	fl = ip6fl_get_first(seq);
617	else
618	fl = ip6fl_get_next(seq, v);
619	++*pos;
620	return fl;
621	}
622
623	static void ip6fl_seq_stop(struct seq_file seq, void v)
624	{
625	read_unlock_bh(&ip6_fl_lock);
626	}
627
628	static void ip6fl_fl_seq_show(struct seq_file seq, struct ip6_flowlabel fl)
629	{
630	while(fl) {
631	seq_printf(seq,
9343e79a	632	"%05X %-1d %-6d %-6d %-6ld %-8ld " NIP6_SEQFMT " %-4d\n",
1da177e4 LT	633	(unsigned)ntohl(fl->label),
	634	fl->share,
	635	(unsigned)fl->owner,
	636	atomic_read(&fl->users),
	637	fl->linger/HZ,
	638	(long)(fl->expires - jiffies)/HZ,
	639	NIP6(fl->dst),
	640	fl->opt ? fl->opt->opt_nflen : 0);
	641	fl = fl->next;
	642	}
	643	}
	644
	645	static int ip6fl_seq_show(struct seq_file seq, void v)
	646	{
	647	if (v == SEQ_START_TOKEN)
9343e79a	648	seq_printf(seq, "%-5s %-1s %-6s %-6s %-6s %-8s %-32s %s\n",
46b86a2d	649	"Label", "S", "Owner", "Users", "Linger", "Expires", "Dst", "Opt");
1da177e4 LT	650	else
	651	ip6fl_fl_seq_show(seq, v);
	652	return 0;
	653	}
	654
	655	static struct seq_operations ip6fl_seq_ops = {
	656	.start = ip6fl_seq_start,
	657	.next = ip6fl_seq_next,
	658	.stop = ip6fl_seq_stop,
	659	.show = ip6fl_seq_show,
	660	};
	661
	662	static int ip6fl_seq_open(struct inode inode, struct file file)
	663	{
	664	struct seq_file *seq;
	665	int rc = -ENOMEM;
	666	struct ip6fl_iter_state s = kmalloc(sizeof(s), GFP_KERNEL);
	667
	668	if (!s)
	669	goto out;
	670
	671	rc = seq_open(file, &ip6fl_seq_ops);
	672	if (rc)
	673	goto out_kfree;
	674
	675	seq = file->private_data;
	676	seq->private = s;
	677	memset(s, 0, sizeof(*s));
	678	out:
	679	return rc;
	680	out_kfree:
	681	kfree(s);
	682	goto out;
	683	}
	684
	685	static struct file_operations ip6fl_seq_fops = {
	686	.owner = THIS_MODULE,
	687	.open = ip6fl_seq_open,
	688	.read = seq_read,
	689	.llseek = seq_lseek,
	690	.release = seq_release_private,
	691	};
	692	#endif
	693
	694
	695	void ip6_flowlabel_init(void)
	696	{
	697	#ifdef CONFIG_PROC_FS
	698	proc_net_fops_create("ip6_flowlabel", S_IRUGO, &ip6fl_seq_fops);
	699	#endif
	700	}
	701
	702	void ip6_flowlabel_cleanup(void)
	703	{
	704	del_timer(&ip6_fl_gc_timer);
	705	#ifdef CONFIG_PROC_FS
	706	proc_net_remove("ip6_flowlabel");
	707	#endif
	708	}