path: root/net/xfrm/xfrm_state.c

/*
 * xfrm_state.c
 *
 * Changes:
 *	Mitsuru KANDA @USAGI
 * 	Kazunori MIYAZAWA @USAGI
 * 	Kunihiro Ishiguro <kunihiro@ipinfusion.com>
 * 		IPv6 support
 * 	YOSHIFUJI Hideaki @USAGI
 * 		Split up af-specific functions
 *	Derek Atkins <derek@ihtfp.com>
 *		Add UDP Encapsulation
 *
 */

#include <linux/workqueue.h>
#include <net/xfrm.h>
#include <linux/pfkeyv2.h>
#include <linux/ipsec.h>
#include <linux/module.h>
#include <asm/uaccess.h>

/* Each xfrm_state may be linked to two tables:

   1. Hash table by (spi,daddr,ah/esp) to find SA by SPI. (input,ctl)
   2. Hash table by daddr to find what SAs exist for given
      destination/tunnel endpoint. (output)
 */

static DEFINE_SPINLOCK(xfrm_state_lock);

/* Hash table to find appropriate SA towards given target (endpoint
 * of tunnel or destination of transport mode) allowed by selector.
 *
 * Main use is finding SA after policy selected tunnel or transport mode.
 * Also, it can be used by ah/esp icmp error handler to find offending SA.
 */
static struct list_head xfrm_state_bydst[XFRM_DST_HSIZE];
static struct list_head xfrm_state_byspi[XFRM_DST_HSIZE];

DECLARE_WAIT_QUEUE_HEAD(km_waitq);
EXPORT_SYMBOL(km_waitq);

static DEFINE_RWLOCK(xfrm_state_afinfo_lock);
static struct xfrm_state_afinfo *xfrm_state_afinfo[NPROTO];

static struct work_struct xfrm_state_gc_work;
static struct list_head xfrm_state_gc_list = LIST_HEAD_INIT(xfrm_state_gc_list);
static DEFINE_SPINLOCK(xfrm_state_gc_lock);

static int xfrm_state_gc_flush_bundles;

static int __xfrm_state_delete(struct xfrm_state *x);

static struct xfrm_state_afinfo *xfrm_state_get_afinfo(unsigned short family);
static void xfrm_state_put_afinfo(struct xfrm_state_afinfo *afinfo);

static int km_query(struct xfrm_state *x, struct xfrm_tmpl *t, struct xfrm_policy *pol);
static void km_state_expired(struct xfrm_state *x, int hard);

static void xfrm_state_gc_destroy(struct xfrm_state *x)
{
	if (del_timer(&x->timer))
		BUG();
	kfree(x->aalg);
	kfree(x->ealg);
	kfree(x->calg);
	kfree(x->encap);
	if (x->type) {
		x->type->destructor(x);
		xfrm_put_type(x->type);
	}
	security_xfrm_state_free(x);
	kfree(x);
}

static void xfrm_state_gc_task(void *data)
{
	struct xfrm_state *x;
	struct list_head *entry, *tmp;
	struct list_head gc_list = LIST_HEAD_INIT(gc_list);

	if (xfrm_state_gc_flush_bundles) {
		xfrm_state_gc_flush_bundles = 0;
		xfrm_flush_bundles();
	}

	spin_lock_bh(&xfrm_state_gc_lock);
	list_splice_init(&xfrm_state_gc_list, &gc_list);
	spin_unlock_bh(&xfrm_state_gc_lock);

	list_for_each_safe(entry, tmp, &gc_list) {
		x = list_entry(entry, struct xfrm_state, bydst);
		xfrm_state_gc_destroy(x);
	}
	wake_up(&km_waitq);
}

static inline unsigned long make_jiffies(long secs)
{
	if (secs >= (MAX_SCHEDULE_TIMEOUT-1)/HZ)
		return MAX_SCHEDULE_TIMEOUT-1;
	else
	        return secs*HZ;
}

static void xfrm_timer_handler(unsigned long data)
{
	struct xfrm_state *x = (struct xfrm_state*)data;
	unsigned long now = (unsigned long)xtime.tv_sec;
	long next = LONG_MAX;
	int warn = 0;

	spin_lock(&x->lock);
	if (x->km.state == XFRM_STATE_DEAD)
		goto out;
	if (x->km.state == XFRM_STATE_EXPIRED)
		goto expired;
	if (x->lft.hard_add_expires_seconds) {
		long tmo = x->lft.hard_add_expires_seconds +
			x->curlft.add_time - now;
		if (tmo <= 0)
			goto expired;
		if (tmo < next)
			next = tmo;