[linux-block.git] / net / ipv6 / xfrm6_tunnel.c

/*
 * Copyright (C)2003,2004 USAGI/WIDE Project
 *
 * 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.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * Authors	Mitsuru KANDA  <mk@linux-ipv6.org>
 * 		YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
 *
 * Based on net/ipv4/xfrm4_tunnel.c
 *
 */
#include <linux/config.h>
#include <linux/module.h>
#include <linux/xfrm.h>
#include <linux/list.h>
#include <net/ip.h>
#include <net/xfrm.h>
#include <net/ipv6.h>
#include <net/protocol.h>
#include <linux/ipv6.h>
#include <linux/icmpv6.h>
#include <linux/mutex.h>

#ifdef CONFIG_IPV6_XFRM6_TUNNEL_DEBUG
# define X6TDEBUG	3
#else
# define X6TDEBUG	1
#endif

#define X6TPRINTK(fmt, args...)		printk(fmt, ## args)
#define X6TNOPRINTK(fmt, args...)	do { ; } while(0)

#if X6TDEBUG >= 1
# define X6TPRINTK1	X6TPRINTK
#else
# define X6TPRINTK1	X6TNOPRINTK
#endif

#if X6TDEBUG >= 3
# define X6TPRINTK3	X6TPRINTK
#else
# define X6TPRINTK3	X6TNOPRINTK
#endif

/*
 * xfrm_tunnel_spi things are for allocating unique id ("spi") 
 * per xfrm_address_t.
 */
struct xfrm6_tunnel_spi {
	struct hlist_node list_byaddr;
	struct hlist_node list_byspi;
	xfrm_address_t addr;
	u32 spi;
	atomic_t refcnt;
#ifdef XFRM6_TUNNEL_SPI_MAGIC
	u32 magic;
#endif
};

#ifdef CONFIG_IPV6_XFRM6_TUNNEL_DEBUG
# define XFRM6_TUNNEL_SPI_MAGIC 0xdeadbeef
#endif

static DEFINE_RWLOCK(xfrm6_tunnel_spi_lock);

static u32 xfrm6_tunnel_spi;

#define XFRM6_TUNNEL_SPI_MIN	1
#define XFRM6_TUNNEL_SPI_MAX	0xffffffff

static kmem_cache_t *xfrm6_tunnel_spi_kmem __read_mostly;

#define XFRM6_TUNNEL_SPI_BYADDR_HSIZE 256
#define XFRM6_TUNNEL_SPI_BYSPI_HSIZE 256

static struct hlist_head xfrm6_tunnel_spi_byaddr[XFRM6_TUNNEL_SPI_BYADDR_HSIZE];
static struct hlist_head xfrm6_tunnel_spi_byspi[XFRM6_TUNNEL_SPI_BYSPI_HSIZE];

#ifdef XFRM6_TUNNEL_SPI_MAGIC
static int x6spi_check_magic(const struct xfrm6_tunnel_spi *x6spi,
			     const char *name)
{
	if (unlikely(x6spi->magic != XFRM6_TUNNEL_SPI_MAGIC)) {
		X6TPRINTK3(KERN_DEBUG "%s(): x6spi object "
				      "at %p has corrupted magic %08x "
				      "(should be %08x)\n",
			   name, x6spi, x6spi->magic, XFRM6_TUNNEL_SPI_MAGIC);
		return -1;
	}
	return 0;
}
#else
static int inline x6spi_check_magic(const struct xfrm6_tunnel_spi *x6spi,
				    const char *name)
{
	return 0;
}
#endif

#define X6SPI_CHECK_MAGIC(x6spi) x6spi_check_magic((x6spi), __FUNCTION__)


static unsigned inline xfrm6_tunnel_spi_hash_byaddr(xfrm_address_t *addr)
{
	unsigned h;

	X6TPRINTK3(KERN_DEBUG "%s(addr=%p)\n", __FUNCTION__, addr);

	h = addr->a6[0] ^ addr->a6[1] ^ addr->a6[2] ^ addr->a6[3];
	h ^= h >> 16;
	h ^= h >> 8;
	h &= XFRM6_TUNNEL_SPI_BYADDR_HSIZE - 1;

	X6TPRINTK3(KERN_DEBUG "%s() = %u\n", __FUNCTION__, h);

	return h;
}

static unsigned inline xfrm6_tunnel_spi_hash_byspi(u32 spi)
{
	return spi % XFRM6_TUNNEL_SPI_BYSPI_HSIZE;
}


static int xfrm6_tunnel_spi_init(void)
{
	int i;

	X6TPRINTK3(KERN_DEBUG "%s()\n", __FUNCTION__);

	xfrm6_tunnel_spi = 0;
	xfrm6_tunnel_spi_kmem = kmem_cache_create("xfrm6_tunnel_spi",
						  sizeof(struct xfrm6_tunnel_spi),
						  0, SLAB_HWCACHE_ALIGN,
						  NULL, NULL);
	if (!xfrm6_tunnel_spi_kmem) {
		X6TPRINTK1(KERN_ERR
			   "%s(): failed to allocate xfrm6_tunnel_spi_kmem\n",
		           __FUNCTION__);
		return -ENOMEM;
	}

	for (i = 0; i < XFRM6_TUNNEL_SPI_BYADDR_HSIZE; i++)
		INIT_HLIST_HEAD(&xfrm6_tunnel_spi_byaddr[i]);
	for (i = 0; i < XFRM6_TUNNEL_SPI_BYSPI_HSIZE; i++)
		INIT_HLIST_HEAD(&xfrm6_tunnel_spi_byspi[i]);
	return 0;
}

static void xfrm6_tunnel_spi_fini(void)
{
	int i;

	X6TPRINTK3(KERN_DEBUG "%s()\n", __FUNCTION__);

	for (i = 0; i < XFRM6_TUNNEL_SPI_BYADDR_HSIZE; i++) {
		if (!hlist_empty(&xfrm6_tunnel_spi_byaddr[i]))
			goto err;
	}
	for (i = 0; i < XFRM6_TUNNEL_SPI_BYSPI_HSIZE; i++) {
		if (!hlist_empty(&xfrm6_tunnel_spi_byspi[i]))
			goto err;
	}
	kmem_cache_destroy(xfrm6_tunnel_spi_kmem);
	xfrm6_tunnel_spi_kmem = NULL;
	return;
err:
	X6TPRINTK1(KERN_ERR "%s(): table is not empty\n", __FUNCTION__);
	return;
}

static struct xfrm6_tunnel_spi *__xfrm6_tunnel_spi_lookup(xfrm_address_t *saddr)
{
	struct xfrm6_tunnel_spi *x6spi;
	struct hlist_node *pos;

	X6TPRINTK3(KERN_DEBUG "%s(saddr=%p)\n", __FUNCTION__, saddr);

	hlist_for_each_entry(x6spi, pos,
			     &xfrm6_tunnel_spi_byaddr[xfrm6_tunnel_spi_hash_byaddr(saddr)],
			     list_byaddr) {
		if (memcmp(&x6spi->addr, saddr, sizeof(x6spi->addr)) == 0) {
			X6SPI_CHECK_MAGIC(x6spi);
			X6TPRINTK3(KERN_DEBUG "%s() = %p(%u)\n", __FUNCTION__, x6spi, x6spi->spi);
			return x6spi;
		}
	}

	X6TPRINTK3(KERN_DEBUG "%s() = NULL(0)\n", __FUNCTION__);
	return NULL;
}

u32 xfrm6_tunnel_spi_lookup(xfrm_address_t *saddr)
{
	struct xfrm6_tunnel_spi *x6spi;
	u32 spi;

	X6TPRINTK3(KERN_DEBUG "%s(saddr=%p)\n", __FUNCTION__, saddr);

	read_lock_bh(&xfrm6_tunnel_spi_lock);
	x6spi = __xfrm6_tunnel_spi_lookup(saddr);
	spi = x6spi ? x6spi->spi : 0;
	read_unlock_bh(&xfrm6_tunnel_spi_lock);
	return spi;
}

EXPORT_SYMBOL(xfrm6_tunnel_spi_lookup);

static u32 __xfrm6_tunnel_alloc_spi(xfrm_address_t *saddr)
{
	u32 spi;
	struct xfrm6_tunnel_spi *x6spi;
	struct hlist_node *pos;
	unsigned index;

	X6TPRINTK3(KERN_DEBUG "%s(saddr=%p)\n", __FUNCTION__, saddr);

	if (xfrm6_tunnel_spi < XFRM6_TUNNEL_SPI_MIN ||
	    xfrm6_tunnel_spi >= XFRM6_TUNNEL_SPI_MAX)
		xfrm6_tunnel_spi = XFRM6_TUNNEL_SPI_MIN;
	else
		xfrm6_tunnel_spi++;

	for (spi = xfrm6_tunnel_spi; spi <= XFRM6_TUNNEL_SPI_MAX; spi++) {
		index = xfrm6_tunnel_spi_hash_byspi(spi);
		hlist_for_each_entry(x6spi, pos, 
				     &xfrm6_tunnel_spi_byspi[index], 
				     list_byspi) {
			if (x6spi->spi == spi)
				goto try_next_1;
		}
		xfrm6_tunnel_spi = spi;
		goto alloc_spi;
try_next_1:;
	}
	for (spi = XFRM6_TUNNEL_SPI_MIN; spi < xfrm6_tunnel_spi; spi++) {
		index = xfrm6_tunnel_spi_hash_byspi(spi);
		hlist_for_each_entry(x6spi, pos, 
				     &xfrm6_tunnel_spi_byspi[index], 
				     list_byspi) {
			if (x6spi->spi == spi)
				goto try_next_2;
		}
		xfrm6_tunnel_spi = spi;
		goto alloc_spi;
try_next_2:;
	}
	spi = 0;
	goto out;
alloc_spi:
	X6TPRINTK3(KERN_DEBUG "%s(): allocate new spi for " NIP6_FMT "\n",
			      __FUNCTION__, 
			      NIP6(*(struct in6_addr *)saddr));
	x6spi = kmem_cache_alloc(xfrm6_tunnel_spi_kmem, SLAB_ATOMIC);
	if (!x6spi) {
		X6TPRINTK1(KERN_ERR "%s(): kmem_cache_alloc() failed\n", 
			   __FUNCTION__);
		goto out;
	}
#ifdef XFRM6_TUNNEL_SPI_MAGIC
	x6spi->magic = XFRM6_TUNNEL_SPI_MAGIC;
#endif
	memcpy(&x6spi->addr, saddr, sizeof(x6spi->addr));
	x6spi->spi = spi;
	atomic_set(&x6spi->refcnt, 1);

	hlist_add_head(&x6spi->list_byspi, &xfrm6_tunnel_spi_byspi[index]);

	index = xfrm6_tunnel_spi_hash_byaddr(saddr);
	hlist_add_head(&x6spi->list_byaddr, &xfrm6_tunnel_spi_byaddr[index]);
	X6SPI_CHECK_MAGIC(x6spi);
out:
	X6TPRINTK3(KERN_DEBUG "%s() = %u\n", __FUNCTION__, spi);
	return spi;
}

u32 xfrm6_tunnel_alloc_spi(xfrm_address_t *saddr)
{
	struct xfrm6_tunnel_spi *x6spi;
	u32 spi;

	X6TPRINTK3(KERN_DEBUG "%s(saddr=%p)\n", __FUNCTION__, saddr);

	write_lock_bh(&xfrm6_tunnel_spi_lock);
	x6spi = __xfrm6_tunnel_spi_lookup(saddr);
	if (x6spi) {
		atomic_inc(&x6spi->refcnt);
		spi = x6spi->spi;
	} else
		spi = __xfrm6_tunnel_alloc_spi(saddr);
	write_unlock_bh(&xfrm6_tunnel_spi_lock);

	X6TPRINTK3(KERN_DEBUG "%s() = %u\n", __FUNCTION__, spi);

	return spi;
}

EXPORT_SYMBOL(xfrm6_tunnel_alloc_spi);

void xfrm6_tunnel_free_spi(xfrm_address_t *saddr)
{
	struct xfrm6_tunnel_spi *x6spi;
	struct hlist_node *pos, *n;

	X6TPRINTK3(KERN_DEBUG "%s(saddr=%p)\n", __FUNCTION__, saddr);

	write_lock_bh(&xfrm6_tunnel_spi_lock);

	hlist_for_each_entry_safe(x6spi, pos, n, 
				  &xfrm6_tunnel_spi_byaddr[xfrm6_tunnel_spi_hash_byaddr(saddr)],
				  list_byaddr)
	{
		if (memcmp(&x6spi->addr, saddr, sizeof(x6spi->addr)) == 0) {
			X6TPRINTK3(KERN_DEBUG "%s(): x6spi object for " NIP6_FMT 
					      " found at %p\n",
				   __FUNCTION__, 
				   NIP6(*(struct in6_addr *)saddr),
				   x6spi);
			X6SPI_CHECK_MAGIC(x6spi);
			if (atomic_dec_and_test(&x6spi->refcnt)) {
				hlist_del(&x6spi->list_byaddr);
				hlist_del(&x6spi->list_byspi);
				kmem_cache_free(xfrm6_tunnel_spi_kmem, x6spi);
				break;
			}
		}
	}
	write_unlock_bh(&xfrm6_tunnel_spi_lock);
}

EXPORT_SYMBOL(xfrm6_tunnel_free_spi);

static int xfrm6_tunnel_output(struct xfrm_state *x, struct sk_buff *skb)
{
	struct ipv6hdr *top_iph;

	top_iph = (struct ipv6hdr *)skb->data;
	top_iph->payload_len = htons(skb->len - sizeof(struct ipv6hdr));

	return 0;
}

static int xfrm6_tunnel_input(struct xfrm_state *x, struct xfrm_decap_state *decap, struct sk_buff *skb)
{
	return 0;
}

static struct xfrm6_tunnel *xfrm6_tunnel_handler;
static DEFINE_MUTEX(xfrm6_tunnel_mutex);

int xfrm6_tunnel_register(struct xfrm6_tunnel *handler)
{
	int ret;

	mutex_lock(&xfrm6_tunnel_mutex);
	ret = 0;
	if (xfrm6_tunnel_handler != NULL)
		ret = -EINVAL;
	if (!ret)
		xfrm6_tunnel_handler = handler;
	mutex_unlock(&xfrm6_tunnel_mutex);

	return ret;
}

EXPORT_SYMBOL(xfrm6_tunnel_register);

int xfrm6_tunnel_deregister(struct xfrm6_tunnel *handler)
{
	int ret;

	mutex_lock(&xfrm6_tunnel_mutex);
	ret = 0;
	if (xfrm6_tunnel_handler != handler)
		ret = -EINVAL;
	if (!ret)
		xfrm6_tunnel_handler = NULL;
	mutex_unlock(&xfrm6_tunnel_mutex);

	synchronize_net();

	return ret;
}

EXPORT_SYMBOL(xfrm6_tunnel_deregister);

static int xfrm6_tunnel_rcv(struct sk_buff **pskb)
{
	struct sk_buff *skb = *pskb;
	struct xfrm6_tunnel *handler = xfrm6_tunnel_handler;
	struct ipv6hdr *iph = skb->nh.ipv6h;
	u32 spi;

	/* device-like_ip6ip6_handler() */
	if (handler && handler->handler(pskb) == 0)
		return 0;

	spi = xfrm6_tunnel_spi_lookup((xfrm_address_t *)&iph->saddr);
	return xfrm6_rcv_spi(pskb, spi);
}

static void xfrm6_tunnel_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
			     int type, int code, int offset, __u32 info)
{
	struct xfrm6_tunnel *handler = xfrm6_tunnel_handler;

	/* call here first for device-like ip6ip6 err handling */
	if (handler) {
		handler->err_handler(skb, opt, type, code, offset, info);
		return;
	}

	/* xfrm6_tunnel native err handling */
	switch (type) {
	case ICMPV6_DEST_UNREACH: 
		switch (code) {
		case ICMPV6_NOROUTE: 
		case ICMPV6_ADM_PROHIBITED:
		case ICMPV6_NOT_NEIGHBOUR:
		case ICMPV6_ADDR_UNREACH:
		case ICMPV6_PORT_UNREACH:
		default:
			X6TPRINTK3(KERN_DEBUG
				   "xfrm6_tunnel: Destination Unreach.\n");
			break;
		}
		break;
	case ICMPV6_PKT_TOOBIG:
			X6TPRINTK3(KERN_DEBUG 
				   "xfrm6_tunnel: Packet Too Big.\n");
		break;
	case ICMPV6_TIME_EXCEED:
		switch (code) {
		case ICMPV6_EXC_HOPLIMIT:
			X6TPRINTK3(KERN_DEBUG
				   "xfrm6_tunnel: Too small Hoplimit.\n");
			break;
		case ICMPV6_EXC_FRAGTIME:
		default: 
			break;
		}
		break;
	case ICMPV6_PARAMPROB:
		switch (code) {
		case ICMPV6_HDR_FIELD: break;
		case ICMPV6_UNK_NEXTHDR: break;
		case ICMPV6_UNK_OPTION: break;
		}
		break;
	default:
		break;
	}
	return;
}

static int xfrm6_tunnel_init_state(struct xfrm_state *x)
{
	if (!x->props.mode)
		return -EINVAL;

	if (x->encap)
		return -EINVAL;

	x->props.header_len = sizeof(struct ipv6hdr);

	return 0;
}

static void xfrm6_tunnel_destroy(struct xfrm_state *x)
{
	xfrm6_tunnel_free_spi((xfrm_address_t *)&x->props.saddr);
}

static struct xfrm_type xfrm6_tunnel_type = {
	.description	= "IP6IP6",
	.owner          = THIS_MODULE,
	.proto		= IPPROTO_IPV6,
	.init_state	= xfrm6_tunnel_init_state,
	.destructor	= xfrm6_tunnel_destroy,
	.input		= xfrm6_tunnel_input,
	.output		= xfrm6_tunnel_output,
};

static struct inet6_protocol xfrm6_tunnel_protocol = {
	.handler	= xfrm6_tunnel_rcv,
	.err_handler	= xfrm6_tunnel_err, 
	.flags          = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
};

static int __init xfrm6_tunnel_init(void)
{
	X6TPRINTK3(KERN_DEBUG "%s()\n", __FUNCTION__);

	if (xfrm_register_type(&xfrm6_tunnel_type, AF_INET6) < 0) {
		X6TPRINTK1(KERN_ERR
			   "xfrm6_tunnel init: can't add xfrm type\n");
		return -EAGAIN;
	}
	if (inet6_add_protocol(&xfrm6_tunnel_protocol, IPPROTO_IPV6) < 0) {
		X6TPRINTK1(KERN_ERR
			   "xfrm6_tunnel init(): can't add protocol\n");
		xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6);
		return -EAGAIN;
	}
	if (xfrm6_tunnel_spi_init() < 0) {
		X6TPRINTK1(KERN_ERR
			   "xfrm6_tunnel init: failed to initialize spi\n");
		inet6_del_protocol(&xfrm6_tunnel_protocol, IPPROTO_IPV6);
		xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6);
		return -EAGAIN;
	}
	return 0;
}

static void __exit xfrm6_tunnel_fini(void)
{
	X6TPRINTK3(KERN_DEBUG "%s()\n", __FUNCTION__);

	xfrm6_tunnel_spi_fini();
	if (inet6_del_protocol(&xfrm6_tunnel_protocol, IPPROTO_IPV6) < 0)
		X6TPRINTK1(KERN_ERR 
			   "xfrm6_tunnel close: can't remove protocol\n");
	if (xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6) < 0)
		X6TPRINTK1(KERN_ERR
			   "xfrm6_tunnel close: can't remove xfrm type\n");
}

module_init(xfrm6_tunnel_init);
module_exit(xfrm6_tunnel_fini);
MODULE_LICENSE("GPL");
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Copyright (C)2003,2004 USAGI/WIDE Project
	3	*
	4	* This program is free software; you can redistribute it and/or modify
	5	* it under the terms of the GNU General Public License as published by
	6	* the Free Software Foundation; either version 2 of the License, or
	7	* (at your option) any later version.
	8	*
	9	* This program is distributed in the hope that it will be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
	13	*
	14	* You should have received a copy of the GNU General Public License
	15	* along with this program; if not, write to the Free Software
	16	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	17	*
	18	* Authors Mitsuru KANDA <mk@linux-ipv6.org>
	19	* YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
	20	*
	21	* Based on net/ipv4/xfrm4_tunnel.c
	22	*
	23	*/
	24	#include <linux/config.h>
	25	#include <linux/module.h>
	26	#include <linux/xfrm.h>
	27	#include <linux/list.h>
	28	#include <net/ip.h>
	29	#include <net/xfrm.h>
	30	#include <net/ipv6.h>
	31	#include <net/protocol.h>
	32	#include <linux/ipv6.h>
	33	#include <linux/icmpv6.h>
4a3e2f71	34	#include <linux/mutex.h>
1da177e4 LT	35
	36	#ifdef CONFIG_IPV6_XFRM6_TUNNEL_DEBUG
	37	# define X6TDEBUG 3
	38	#else
	39	# define X6TDEBUG 1
	40	#endif
	41
	42	#define X6TPRINTK(fmt, args...) printk(fmt, ## args)
	43	#define X6TNOPRINTK(fmt, args...) do { ; } while(0)
	44
	45	#if X6TDEBUG >= 1
	46	# define X6TPRINTK1 X6TPRINTK
	47	#else
	48	# define X6TPRINTK1 X6TNOPRINTK
	49	#endif
	50
	51	#if X6TDEBUG >= 3
	52	# define X6TPRINTK3 X6TPRINTK
	53	#else
	54	# define X6TPRINTK3 X6TNOPRINTK
	55	#endif
	56
	57	/*
	58	* xfrm_tunnel_spi things are for allocating unique id ("spi")
	59	* per xfrm_address_t.
	60	*/
	61	struct xfrm6_tunnel_spi {
	62	struct hlist_node list_byaddr;
	63	struct hlist_node list_byspi;
	64	xfrm_address_t addr;
	65	u32 spi;
	66	atomic_t refcnt;
	67	#ifdef XFRM6_TUNNEL_SPI_MAGIC
	68	u32 magic;
	69	#endif
	70	};
	71
	72	#ifdef CONFIG_IPV6_XFRM6_TUNNEL_DEBUG
	73	# define XFRM6_TUNNEL_SPI_MAGIC 0xdeadbeef
	74	#endif
	75
	76	static DEFINE_RWLOCK(xfrm6_tunnel_spi_lock);
	77
	78	static u32 xfrm6_tunnel_spi;
	79
	80	#define XFRM6_TUNNEL_SPI_MIN 1
	81	#define XFRM6_TUNNEL_SPI_MAX 0xffffffff
	82
ba89966c	83	static kmem_cache_t *xfrm6_tunnel_spi_kmem __read_mostly;
1da177e4 LT	84
	85	#define XFRM6_TUNNEL_SPI_BYADDR_HSIZE 256
	86	#define XFRM6_TUNNEL_SPI_BYSPI_HSIZE 256
	87
	88	static struct hlist_head xfrm6_tunnel_spi_byaddr[XFRM6_TUNNEL_SPI_BYADDR_HSIZE];
	89	static struct hlist_head xfrm6_tunnel_spi_byspi[XFRM6_TUNNEL_SPI_BYSPI_HSIZE];
	90
	91	#ifdef XFRM6_TUNNEL_SPI_MAGIC
	92	static int x6spi_check_magic(const struct xfrm6_tunnel_spi *x6spi,
	93	const char *name)
	94	{
	95	if (unlikely(x6spi->magic != XFRM6_TUNNEL_SPI_MAGIC)) {
	96	X6TPRINTK3(KERN_DEBUG "%s(): x6spi object "
	97	"at %p has corrupted magic %08x "
	98	"(should be %08x)\n",
	99	name, x6spi, x6spi->magic, XFRM6_TUNNEL_SPI_MAGIC);
	100	return -1;
	101	}
	102	return 0;
	103	}
	104	#else
	105	static int inline x6spi_check_magic(const struct xfrm6_tunnel_spi *x6spi,
	106	const char *name)
	107	{
	108	return 0;
	109	}
	110	#endif
	111
	112	#define X6SPI_CHECK_MAGIC(x6spi) x6spi_check_magic((x6spi), __FUNCTION__)
	113
	114
	115	static unsigned inline xfrm6_tunnel_spi_hash_byaddr(xfrm_address_t *addr)
	116	{
	117	unsigned h;
	118
	119	X6TPRINTK3(KERN_DEBUG "%s(addr=%p)\n", __FUNCTION__, addr);
	120
	121	h = addr->a6[0] ^ addr->a6[1] ^ addr->a6[2] ^ addr->a6[3];
	122	h ^= h >> 16;
	123	h ^= h >> 8;
	124	h &= XFRM6_TUNNEL_SPI_BYADDR_HSIZE - 1;
	125
	126	X6TPRINTK3(KERN_DEBUG "%s() = %u\n", __FUNCTION__, h);
	127
	128	return h;
	129	}
	130
	131	static unsigned inline xfrm6_tunnel_spi_hash_byspi(u32 spi)
	132	{
	133	return spi % XFRM6_TUNNEL_SPI_BYSPI_HSIZE;
	134	}
	135
	136
	137	static int xfrm6_tunnel_spi_init(void)
	138	{
	139	int i;
	140
	141	X6TPRINTK3(KERN_DEBUG "%s()\n", __FUNCTION__);
	142
	143	xfrm6_tunnel_spi = 0;
	144	xfrm6_tunnel_spi_kmem = kmem_cache_create("xfrm6_tunnel_spi",
	145	sizeof(struct xfrm6_tunnel_spi),
	146	0, SLAB_HWCACHE_ALIGN,
	147	NULL, NULL);
148	if (!xfrm6_tunnel_spi_kmem) {
149	X6TPRINTK1(KERN_ERR
150	"%s(): failed to allocate xfrm6_tunnel_spi_kmem\n",
151	__FUNCTION__);
152	return -ENOMEM;
153	}
154
155	for (i = 0; i < XFRM6_TUNNEL_SPI_BYADDR_HSIZE; i++)
156	INIT_HLIST_HEAD(&xfrm6_tunnel_spi_byaddr[i]);
157	for (i = 0; i < XFRM6_TUNNEL_SPI_BYSPI_HSIZE; i++)
158	INIT_HLIST_HEAD(&xfrm6_tunnel_spi_byspi[i]);
159	return 0;
160	}
161
162	static void xfrm6_tunnel_spi_fini(void)
163	{
164	int i;
165
166	X6TPRINTK3(KERN_DEBUG "%s()\n", __FUNCTION__);
167
168	for (i = 0; i < XFRM6_TUNNEL_SPI_BYADDR_HSIZE; i++) {
169	if (!hlist_empty(&xfrm6_tunnel_spi_byaddr[i]))
170	goto err;
171	}
172	for (i = 0; i < XFRM6_TUNNEL_SPI_BYSPI_HSIZE; i++) {
173	if (!hlist_empty(&xfrm6_tunnel_spi_byspi[i]))
174	goto err;
175	}
176	kmem_cache_destroy(xfrm6_tunnel_spi_kmem);
177	xfrm6_tunnel_spi_kmem = NULL;
178	return;
179	err:
180	X6TPRINTK1(KERN_ERR "%s(): table is not empty\n", __FUNCTION__);
181	return;
182	}
183
184	static struct xfrm6_tunnel_spi __xfrm6_tunnel_spi_lookup(xfrm_address_t saddr)
185	{
186	struct xfrm6_tunnel_spi *x6spi;
187	struct hlist_node *pos;
188
189	X6TPRINTK3(KERN_DEBUG "%s(saddr=%p)\n", __FUNCTION__, saddr);
190
191	hlist_for_each_entry(x6spi, pos,
192	&xfrm6_tunnel_spi_byaddr[xfrm6_tunnel_spi_hash_byaddr(saddr)],
193	list_byaddr) {
194	if (memcmp(&x6spi->addr, saddr, sizeof(x6spi->addr)) == 0) {
195	X6SPI_CHECK_MAGIC(x6spi);
196	X6TPRINTK3(KERN_DEBUG "%s() = %p(%u)\n", __FUNCTION__, x6spi, x6spi->spi);
197	return x6spi;
198	}
199	}
200
201	X6TPRINTK3(KERN_DEBUG "%s() = NULL(0)\n", __FUNCTION__);
202	return NULL;
203	}
204
205	u32 xfrm6_tunnel_spi_lookup(xfrm_address_t *saddr)
206	{
207	struct xfrm6_tunnel_spi *x6spi;
208	u32 spi;
209
210	X6TPRINTK3(KERN_DEBUG "%s(saddr=%p)\n", __FUNCTION__, saddr);
211
212	read_lock_bh(&xfrm6_tunnel_spi_lock);
213	x6spi = __xfrm6_tunnel_spi_lookup(saddr);
214	spi = x6spi ? x6spi->spi : 0;
215	read_unlock_bh(&xfrm6_tunnel_spi_lock);
216	return spi;
217	}
218
219	EXPORT_SYMBOL(xfrm6_tunnel_spi_lookup);
220
221	static u32 __xfrm6_tunnel_alloc_spi(xfrm_address_t *saddr)
222	{
223	u32 spi;
224	struct xfrm6_tunnel_spi *x6spi;
225	struct hlist_node *pos;
226	unsigned index;
227
228	X6TPRINTK3(KERN_DEBUG "%s(saddr=%p)\n", __FUNCTION__, saddr);
229
230	if (xfrm6_tunnel_spi < XFRM6_TUNNEL_SPI_MIN \|\|
231	xfrm6_tunnel_spi >= XFRM6_TUNNEL_SPI_MAX)
232	xfrm6_tunnel_spi = XFRM6_TUNNEL_SPI_MIN;
233	else
234	xfrm6_tunnel_spi++;
235
236	for (spi = xfrm6_tunnel_spi; spi <= XFRM6_TUNNEL_SPI_MAX; spi++) {
237	index = xfrm6_tunnel_spi_hash_byspi(spi);
238	hlist_for_each_entry(x6spi, pos,
239	&xfrm6_tunnel_spi_byspi[index],
240	list_byspi) {
241	if (x6spi->spi == spi)
242	goto try_next_1;
243	}
244	xfrm6_tunnel_spi = spi;
245	goto alloc_spi;
246	try_next_1:;
247	}
248	for (spi = XFRM6_TUNNEL_SPI_MIN; spi < xfrm6_tunnel_spi; spi++) {
249	index = xfrm6_tunnel_spi_hash_byspi(spi);
250	hlist_for_each_entry(x6spi, pos,
251	&xfrm6_tunnel_spi_byspi[index],
252	list_byspi) {
253	if (x6spi->spi == spi)
254	goto try_next_2;
255	}
256	xfrm6_tunnel_spi = spi;
257	goto alloc_spi;
258	try_next_2:;
259	}
260	spi = 0;
261	goto out;
262	alloc_spi:
46b86a2d	263	X6TPRINTK3(KERN_DEBUG "%s(): allocate new spi for " NIP6_FMT "\n",
1da177e4 LT	264	__FUNCTION__,
	265	NIP6((struct in6_addr )saddr));
	266	x6spi = kmem_cache_alloc(xfrm6_tunnel_spi_kmem, SLAB_ATOMIC);
	267	if (!x6spi) {
	268	X6TPRINTK1(KERN_ERR "%s(): kmem_cache_alloc() failed\n",
	269	__FUNCTION__);
	270	goto out;
	271	}
	272	#ifdef XFRM6_TUNNEL_SPI_MAGIC
	273	x6spi->magic = XFRM6_TUNNEL_SPI_MAGIC;
	274	#endif
	275	memcpy(&x6spi->addr, saddr, sizeof(x6spi->addr));
	276	x6spi->spi = spi;
	277	atomic_set(&x6spi->refcnt, 1);
	278
	279	hlist_add_head(&x6spi->list_byspi, &xfrm6_tunnel_spi_byspi[index]);
	280
	281	index = xfrm6_tunnel_spi_hash_byaddr(saddr);
	282	hlist_add_head(&x6spi->list_byaddr, &xfrm6_tunnel_spi_byaddr[index]);
	283	X6SPI_CHECK_MAGIC(x6spi);
	284	out:
	285	X6TPRINTK3(KERN_DEBUG "%s() = %u\n", __FUNCTION__, spi);
	286	return spi;
	287	}
	288
	289	u32 xfrm6_tunnel_alloc_spi(xfrm_address_t *saddr)
	290	{
	291	struct xfrm6_tunnel_spi *x6spi;
	292	u32 spi;
	293
	294	X6TPRINTK3(KERN_DEBUG "%s(saddr=%p)\n", __FUNCTION__, saddr);
	295
	296	write_lock_bh(&xfrm6_tunnel_spi_lock);
	297	x6spi = __xfrm6_tunnel_spi_lookup(saddr);
	298	if (x6spi) {
	299	atomic_inc(&x6spi->refcnt);
	300	spi = x6spi->spi;
	301	} else
	302	spi = __xfrm6_tunnel_alloc_spi(saddr);
	303	write_unlock_bh(&xfrm6_tunnel_spi_lock);
	304
	305	X6TPRINTK3(KERN_DEBUG "%s() = %u\n", __FUNCTION__, spi);
	306
	307	return spi;
	308	}
	309
	310	EXPORT_SYMBOL(xfrm6_tunnel_alloc_spi);
	311
	312	void xfrm6_tunnel_free_spi(xfrm_address_t *saddr)
	313	{
	314	struct xfrm6_tunnel_spi *x6spi;
	315	struct hlist_node pos, n;
	316
	317	X6TPRINTK3(KERN_DEBUG "%s(saddr=%p)\n", __FUNCTION__, saddr);
	318
	319	write_lock_bh(&xfrm6_tunnel_spi_lock);
	320
	321	hlist_for_each_entry_safe(x6spi, pos, n,
	322	&xfrm6_tunnel_spi_byaddr[xfrm6_tunnel_spi_hash_byaddr(saddr)],
	323	list_byaddr)
	324	{
	325	if (memcmp(&x6spi->addr, saddr, sizeof(x6spi->addr)) == 0) {
46b86a2d JP	326	X6TPRINTK3(KERN_DEBUG "%s(): x6spi object for " NIP6_FMT
46b86a2d JP	327	" found at %p\n",
1da177e4 LT	328	__FUNCTION__,
	329	NIP6((struct in6_addr )saddr),
	330	x6spi);
	331	X6SPI_CHECK_MAGIC(x6spi);
	332	if (atomic_dec_and_test(&x6spi->refcnt)) {
	333	hlist_del(&x6spi->list_byaddr);
	334	hlist_del(&x6spi->list_byspi);
	335	kmem_cache_free(xfrm6_tunnel_spi_kmem, x6spi);
	336	break;
	337	}
	338	}
	339	}
	340	write_unlock_bh(&xfrm6_tunnel_spi_lock);
	341	}
	342
	343	EXPORT_SYMBOL(xfrm6_tunnel_free_spi);
	344
	345	static int xfrm6_tunnel_output(struct xfrm_state x, struct sk_buff skb)
	346	{
	347	struct ipv6hdr *top_iph;
	348
	349	top_iph = (struct ipv6hdr *)skb->data;
	350	top_iph->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
	351
	352	return 0;
	353	}
	354
	355	static int xfrm6_tunnel_input(struct xfrm_state x, struct xfrm_decap_state decap, struct sk_buff *skb)
	356	{
	357	return 0;
	358	}
	359
	360	static struct xfrm6_tunnel *xfrm6_tunnel_handler;
4a3e2f71	361	static DEFINE_MUTEX(xfrm6_tunnel_mutex);
1da177e4 LT	362
	363	int xfrm6_tunnel_register(struct xfrm6_tunnel *handler)
	364	{
	365	int ret;
	366
4a3e2f71	367	mutex_lock(&xfrm6_tunnel_mutex);
1da177e4 LT	368	ret = 0;
	369	if (xfrm6_tunnel_handler != NULL)
	370	ret = -EINVAL;
	371	if (!ret)
	372	xfrm6_tunnel_handler = handler;
4a3e2f71	373	mutex_unlock(&xfrm6_tunnel_mutex);
1da177e4 LT	374
	375	return ret;
	376	}
	377
	378	EXPORT_SYMBOL(xfrm6_tunnel_register);
	379
	380	int xfrm6_tunnel_deregister(struct xfrm6_tunnel *handler)
	381	{
	382	int ret;
	383
4a3e2f71	384	mutex_lock(&xfrm6_tunnel_mutex);
1da177e4 LT	385	ret = 0;
	386	if (xfrm6_tunnel_handler != handler)
	387	ret = -EINVAL;
	388	if (!ret)
	389	xfrm6_tunnel_handler = NULL;
4a3e2f71	390	mutex_unlock(&xfrm6_tunnel_mutex);
1da177e4 LT	391
	392	synchronize_net();
	393
	394	return ret;
	395	}
	396
	397	EXPORT_SYMBOL(xfrm6_tunnel_deregister);
	398
951dbc8a	399	static int xfrm6_tunnel_rcv(struct sk_buff **pskb)
1da177e4 LT	400	{
	401	struct sk_buff skb = pskb;
	402	struct xfrm6_tunnel *handler = xfrm6_tunnel_handler;
	403	struct ipv6hdr *iph = skb->nh.ipv6h;
	404	u32 spi;
	405
	406	/* device-like_ip6ip6_handler() */
951dbc8a	407	if (handler && handler->handler(pskb) == 0)
1da177e4 LT	408	return 0;
	409
	410	spi = xfrm6_tunnel_spi_lookup((xfrm_address_t *)&iph->saddr);
951dbc8a	411	return xfrm6_rcv_spi(pskb, spi);
1da177e4 LT	412	}
	413
	414	static void xfrm6_tunnel_err(struct sk_buff skb, struct inet6_skb_parm opt,
	415	int type, int code, int offset, __u32 info)
	416	{
	417	struct xfrm6_tunnel *handler = xfrm6_tunnel_handler;
	418
	419	/* call here first for device-like ip6ip6 err handling */
	420	if (handler) {
	421	handler->err_handler(skb, opt, type, code, offset, info);
	422	return;
	423	}
	424
	425	/* xfrm6_tunnel native err handling */
	426	switch (type) {
	427	case ICMPV6_DEST_UNREACH:
	428	switch (code) {
	429	case ICMPV6_NOROUTE:
	430	case ICMPV6_ADM_PROHIBITED:
	431	case ICMPV6_NOT_NEIGHBOUR:
	432	case ICMPV6_ADDR_UNREACH:
	433	case ICMPV6_PORT_UNREACH:
	434	default:
	435	X6TPRINTK3(KERN_DEBUG
	436	"xfrm6_tunnel: Destination Unreach.\n");
	437	break;
	438	}
	439	break;
	440	case ICMPV6_PKT_TOOBIG:
	441	X6TPRINTK3(KERN_DEBUG
	442	"xfrm6_tunnel: Packet Too Big.\n");
	443	break;
	444	case ICMPV6_TIME_EXCEED:
	445	switch (code) {
	446	case ICMPV6_EXC_HOPLIMIT:
	447	X6TPRINTK3(KERN_DEBUG
	448	"xfrm6_tunnel: Too small Hoplimit.\n");
	449	break;
	450	case ICMPV6_EXC_FRAGTIME:
	451	default:
	452	break;
	453	}
	454	break;
	455	case ICMPV6_PARAMPROB:
	456	switch (code) {
	457	case ICMPV6_HDR_FIELD: break;
	458	case ICMPV6_UNK_NEXTHDR: break;
	459	case ICMPV6_UNK_OPTION: break;
	460	}
	461	break;
	462	default:
	463	break;
	464	}
	465	return;
	466	}
	467
72cb6962	468	static int xfrm6_tunnel_init_state(struct xfrm_state *x)
1da177e4 LT	469	{
	470	if (!x->props.mode)
	471	return -EINVAL;
	472
	473	if (x->encap)
	474	return -EINVAL;
	475
	476	x->props.header_len = sizeof(struct ipv6hdr);
	477
	478	return 0;
	479	}
	480
	481	static void xfrm6_tunnel_destroy(struct xfrm_state *x)
	482	{
	483	xfrm6_tunnel_free_spi((xfrm_address_t *)&x->props.saddr);
	484	}
	485
	486	static struct xfrm_type xfrm6_tunnel_type = {
	487	.description = "IP6IP6",
	488	.owner = THIS_MODULE,
	489	.proto = IPPROTO_IPV6,
	490	.init_state = xfrm6_tunnel_init_state,
	491	.destructor = xfrm6_tunnel_destroy,
	492	.input = xfrm6_tunnel_input,
	493	.output = xfrm6_tunnel_output,
	494	};
	495
	496	static struct inet6_protocol xfrm6_tunnel_protocol = {
	497	.handler = xfrm6_tunnel_rcv,
	498	.err_handler = xfrm6_tunnel_err,
	499	.flags = INET6_PROTO_NOPOLICY\|INET6_PROTO_FINAL,
	500	};
	501
	502	static int __init xfrm6_tunnel_init(void)
	503	{
	504	X6TPRINTK3(KERN_DEBUG "%s()\n", __FUNCTION__);
	505
	506	if (xfrm_register_type(&xfrm6_tunnel_type, AF_INET6) < 0) {
	507	X6TPRINTK1(KERN_ERR
	508	"xfrm6_tunnel init: can't add xfrm type\n");
	509	return -EAGAIN;
	510	}
	511	if (inet6_add_protocol(&xfrm6_tunnel_protocol, IPPROTO_IPV6) < 0) {
	512	X6TPRINTK1(KERN_ERR
	513	"xfrm6_tunnel init(): can't add protocol\n");
	514	xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6);
	515	return -EAGAIN;
	516	}
	517	if (xfrm6_tunnel_spi_init() < 0) {
	518	X6TPRINTK1(KERN_ERR
	519	"xfrm6_tunnel init: failed to initialize spi\n");
	520	inet6_del_protocol(&xfrm6_tunnel_protocol, IPPROTO_IPV6);
	521	xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6);
	522	return -EAGAIN;
	523	}
	524	return 0;
	525	}
	526
	527	static void __exit xfrm6_tunnel_fini(void)
	528	{
	529	X6TPRINTK3(KERN_DEBUG "%s()\n", __FUNCTION__);
	530
	531	xfrm6_tunnel_spi_fini();
	532	if (inet6_del_protocol(&xfrm6_tunnel_protocol, IPPROTO_IPV6) < 0)
533	X6TPRINTK1(KERN_ERR
534	"xfrm6_tunnel close: can't remove protocol\n");
535	if (xfrm_unregister_type(&xfrm6_tunnel_type, AF_INET6) < 0)
536	X6TPRINTK1(KERN_ERR
537	"xfrm6_tunnel close: can't remove xfrm type\n");
538	}
539
540	module_init(xfrm6_tunnel_init);
541	module_exit(xfrm6_tunnel_fini);
542	MODULE_LICENSE("GPL");