[linux-2.6-block.git] / net / ipv6 / ipcomp6.c

/*
 * IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173
 *
 * Copyright (C)2003 USAGI/WIDE Project
 *
 * Author	Mitsuru KANDA  <mk@linux-ipv6.org>
 *
 * 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
 */
/*
 * [Memo]
 *
 * Outbound:
 *  The compression of IP datagram MUST be done before AH/ESP processing,
 *  fragmentation, and the addition of Hop-by-Hop/Routing header.
 *
 * Inbound:
 *  The decompression of IP datagram MUST be done after the reassembly,
 *  AH/ESP processing.
 */
#include <linux/module.h>
#include <net/ip.h>
#include <net/xfrm.h>
#include <net/ipcomp.h>
#include <asm/semaphore.h>
#include <linux/crypto.h>
#include <linux/pfkeyv2.h>
#include <linux/random.h>
#include <linux/percpu.h>
#include <linux/smp.h>
#include <linux/list.h>
#include <linux/vmalloc.h>
#include <linux/rtnetlink.h>
#include <net/icmp.h>
#include <net/ipv6.h>
#include <net/protocol.h>
#include <linux/ipv6.h>
#include <linux/icmpv6.h>
#include <linux/mutex.h>

struct ipcomp6_tfms {
	struct list_head list;
	struct crypto_comp **tfms;
	int users;
};

static DEFINE_MUTEX(ipcomp6_resource_mutex);
static void **ipcomp6_scratches;
static int ipcomp6_scratch_users;
static LIST_HEAD(ipcomp6_tfms_list);

static int ipcomp6_input(struct xfrm_state *x, struct sk_buff *skb)
{
	int err = -ENOMEM;
	struct ip_comp_hdr *ipch;
	int plen, dlen;
	struct ipcomp_data *ipcd = x->data;
	u8 *start, *scratch;
	struct crypto_comp *tfm;
	int cpu;

	if (skb_linearize_cow(skb))
		goto out;

	skb->ip_summed = CHECKSUM_NONE;

	/* Remove ipcomp header and decompress original payload */
	ipch = (void *)skb->data;
	skb->transport_header = skb->network_header + sizeof(*ipch);
	__skb_pull(skb, sizeof(*ipch));

	/* decompression */
	plen = skb->len;
	dlen = IPCOMP_SCRATCH_SIZE;
	start = skb->data;

	cpu = get_cpu();
	scratch = *per_cpu_ptr(ipcomp6_scratches, cpu);
	tfm = *per_cpu_ptr(ipcd->tfms, cpu);

	err = crypto_comp_decompress(tfm, start, plen, scratch, &dlen);
	if (err)
		goto out_put_cpu;

	if (dlen < (plen + sizeof(*ipch))) {
		err = -EINVAL;
		goto out_put_cpu;
	}

	err = pskb_expand_head(skb, 0, dlen - plen, GFP_ATOMIC);
	if (err) {
		goto out_put_cpu;
	}

	skb->truesize += dlen - plen;
	__skb_put(skb, dlen - plen);
	skb_copy_to_linear_data(skb, scratch, dlen);
	err = ipch->nexthdr;

out_put_cpu:
	put_cpu();
out:
	return err;
}

static int ipcomp6_output(struct xfrm_state *x, struct sk_buff *skb)
{
	int err;
	struct ip_comp_hdr *ipch;
	struct ipcomp_data *ipcd = x->data;
	int plen, dlen;
	u8 *start, *scratch;
	struct crypto_comp *tfm;
	int cpu;

	/* check whether datagram len is larger than threshold */
	if (skb->len < ipcd->threshold) {
		goto out_ok;
	}

	if (skb_linearize_cow(skb))
		goto out_ok;

	/* compression */
	plen = skb->len;
	dlen = IPCOMP_SCRATCH_SIZE;
	start = skb->data;

	cpu = get_cpu();
	scratch = *per_cpu_ptr(ipcomp6_scratches, cpu);
	tfm = *per_cpu_ptr(ipcd->tfms, cpu);

	err = crypto_comp_compress(tfm, start, plen, scratch, &dlen);
	if (err || (dlen + sizeof(*ipch)) >= plen) {
		put_cpu();
		goto out_ok;
	}
	memcpy(start + sizeof(struct ip_comp_hdr), scratch, dlen);
	put_cpu();
	pskb_trim(skb, dlen + sizeof(struct ip_comp_hdr));

	/* insert ipcomp header and replace datagram */
	ipch = ip_comp_hdr(skb);
	ipch->nexthdr = *skb_mac_header(skb);
	ipch->flags = 0;
	ipch->cpi = htons((u16 )ntohl(x->id.spi));
	*skb_mac_header(skb) = IPPROTO_COMP;

out_ok:
	skb_push(skb, -skb_network_offset(skb));

	return 0;
}

static void ipcomp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
				int type, int code, int offset, __be32 info)
{
	__be32 spi;
	struct ipv6hdr *iph = (struct ipv6hdr*)skb->data;
	struct ip_comp_hdr *ipcomph =
		(struct ip_comp_hdr *)(skb->data + offset);
	struct xfrm_state *x;

	if (type != ICMPV6_DEST_UNREACH && type != ICMPV6_PKT_TOOBIG)
		return;

	spi = htonl(ntohs(ipcomph->cpi));
	x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, spi, IPPROTO_COMP, AF_INET6);
	if (!x)
		return;

	printk(KERN_DEBUG "pmtu discovery on SA IPCOMP/%08x/" NIP6_FMT "\n",
			spi, NIP6(iph->daddr));
	xfrm_state_put(x);
}

static struct xfrm_state *ipcomp6_tunnel_create(struct xfrm_state *x)
{
	struct xfrm_state *t = NULL;
	u8 mode = XFRM_MODE_TUNNEL;

	t = xfrm_state_alloc();
	if (!t)
		goto out;

	t->id.proto = IPPROTO_IPV6;
	t->id.spi = xfrm6_tunnel_alloc_spi((xfrm_address_t *)&x->props.saddr);
	if (!t->id.spi)
		goto error;

	memcpy(t->id.daddr.a6, x->id.daddr.a6, sizeof(struct in6_addr));
	memcpy(&t->sel, &x->sel, sizeof(t->sel));
	t->props.family = AF_INET6;
	if (x->props.mode == XFRM_MODE_BEET)
		mode = x->props.mode;
	t->props.mode = mode;
	memcpy(t->props.saddr.a6, x->props.saddr.a6, sizeof(struct in6_addr));

	if (xfrm_init_state(t))
		goto error;

	atomic_set(&t->tunnel_users, 1);

out:
	return t;

error:
	t->km.state = XFRM_STATE_DEAD;
	xfrm_state_put(t);
	t = NULL;
	goto out;
}

static int ipcomp6_tunnel_attach(struct xfrm_state *x)
{
	int err = 0;
	struct xfrm_state *t = NULL;
	__be32 spi;

	spi = xfrm6_tunnel_spi_lookup((xfrm_address_t *)&x->props.saddr);
	if (spi)
		t = xfrm_state_lookup((xfrm_address_t *)&x->id.daddr,
					      spi, IPPROTO_IPV6, AF_INET6);
	if (!t) {
		t = ipcomp6_tunnel_create(x);
		if (!t) {
			err = -EINVAL;
			goto out;
		}
		xfrm_state_insert(t);
		xfrm_state_hold(t);
	}
	x->tunnel = t;
	atomic_inc(&t->tunnel_users);

out:
	return err;
}

static void ipcomp6_free_scratches(void)
{
	int i;
	void **scratches;

	if (--ipcomp6_scratch_users)
		return;

	scratches = ipcomp6_scratches;
	if (!scratches)
		return;

	for_each_possible_cpu(i) {
		void *scratch = *per_cpu_ptr(scratches, i);

		vfree(scratch);
	}

	free_percpu(scratches);
}

static void **ipcomp6_alloc_scratches(void)
{
	int i;
	void **scratches;

	if (ipcomp6_scratch_users++)
		return ipcomp6_scratches;

	scratches = alloc_percpu(void *);
	if (!scratches)
		return NULL;

	ipcomp6_scratches = scratches;

	for_each_possible_cpu(i) {
		void *scratch = vmalloc(IPCOMP_SCRATCH_SIZE);
		if (!scratch)
			return NULL;
		*per_cpu_ptr(scratches, i) = scratch;
	}

	return scratches;
}

static void ipcomp6_free_tfms(struct crypto_comp **tfms)
{
	struct ipcomp6_tfms *pos;
	int cpu;

	list_for_each_entry(pos, &ipcomp6_tfms_list, list) {
		if (pos->tfms == tfms)
			break;
	}

	BUG_TRAP(pos);

	if (--pos->users)
		return;

	list_del(&pos->list);
	kfree(pos);

	if (!tfms)
		return;

	for_each_possible_cpu(cpu) {
		struct crypto_comp *tfm = *per_cpu_ptr(tfms, cpu);
		crypto_free_comp(tfm);
	}
	free_percpu(tfms);
}

static struct crypto_comp **ipcomp6_alloc_tfms(const char *alg_name)
{
	struct ipcomp6_tfms *pos;
	struct crypto_comp **tfms;
	int cpu;

	/* This can be any valid CPU ID so we don't need locking. */
	cpu = raw_smp_processor_id();

	list_for_each_entry(pos, &ipcomp6_tfms_list, list) {
		struct crypto_comp *tfm;

		tfms = pos->tfms;
		tfm = *per_cpu_ptr(tfms, cpu);

		if (!strcmp(crypto_comp_name(tfm), alg_name)) {
			pos->users++;
			return tfms;
		}
	}

	pos = kmalloc(sizeof(*pos), GFP_KERNEL);
	if (!pos)
		return NULL;

	pos->users = 1;
	INIT_LIST_HEAD(&pos->list);
	list_add(&pos->list, &ipcomp6_tfms_list);

	pos->tfms = tfms = alloc_percpu(struct crypto_comp *);
	if (!tfms)
		goto error;

	for_each_possible_cpu(cpu) {
		struct crypto_comp *tfm = crypto_alloc_comp(alg_name, 0,
							    CRYPTO_ALG_ASYNC);
		if (!tfm)
			goto error;
		*per_cpu_ptr(tfms, cpu) = tfm;
	}

	return tfms;

error:
	ipcomp6_free_tfms(tfms);
	return NULL;
}

static void ipcomp6_free_data(struct ipcomp_data *ipcd)
{
	if (ipcd->tfms)
		ipcomp6_free_tfms(ipcd->tfms);
	ipcomp6_free_scratches();
}

static void ipcomp6_destroy(struct xfrm_state *x)
{
	struct ipcomp_data *ipcd = x->data;
	if (!ipcd)
		return;
	xfrm_state_delete_tunnel(x);
	mutex_lock(&ipcomp6_resource_mutex);
	ipcomp6_free_data(ipcd);
	mutex_unlock(&ipcomp6_resource_mutex);
	kfree(ipcd);

	xfrm6_tunnel_free_spi((xfrm_address_t *)&x->props.saddr);
}

static int ipcomp6_init_state(struct xfrm_state *x)
{
	int err;
	struct ipcomp_data *ipcd;
	struct xfrm_algo_desc *calg_desc;

	err = -EINVAL;
	if (!x->calg)
		goto out;

	if (x->encap)
		goto out;

	err = -ENOMEM;
	ipcd = kzalloc(sizeof(*ipcd), GFP_KERNEL);
	if (!ipcd)
		goto out;

	x->props.header_len = 0;
	switch (x->props.mode) {
	case XFRM_MODE_BEET:
	case XFRM_MODE_TRANSPORT:
		break;
	case XFRM_MODE_TUNNEL:
		x->props.header_len += sizeof(struct ipv6hdr);
	default:
		goto error;
	}

	mutex_lock(&ipcomp6_resource_mutex);
	if (!ipcomp6_alloc_scratches())
		goto error;

	ipcd->tfms = ipcomp6_alloc_tfms(x->calg->alg_name);
	if (!ipcd->tfms)
		goto error;
	mutex_unlock(&ipcomp6_resource_mutex);

	if (x->props.mode == XFRM_MODE_TUNNEL) {
		err = ipcomp6_tunnel_attach(x);
		if (err)
			goto error_tunnel;
	}

	calg_desc = xfrm_calg_get_byname(x->calg->alg_name, 0);
	BUG_ON(!calg_desc);
	ipcd->threshold = calg_desc->uinfo.comp.threshold;
	x->data = ipcd;
	err = 0;
out:
	return err;
error_tunnel:
	mutex_lock(&ipcomp6_resource_mutex);
error:
	ipcomp6_free_data(ipcd);
	mutex_unlock(&ipcomp6_resource_mutex);
	kfree(ipcd);

	goto out;
}

static struct xfrm_type ipcomp6_type =
{
	.description	= "IPCOMP6",
	.owner		= THIS_MODULE,
	.proto		= IPPROTO_COMP,
	.init_state	= ipcomp6_init_state,
	.destructor	= ipcomp6_destroy,
	.input		= ipcomp6_input,
	.output		= ipcomp6_output,
	.hdr_offset	= xfrm6_find_1stfragopt,
};

static struct inet6_protocol ipcomp6_protocol =
{
	.handler	= xfrm6_rcv,
	.err_handler	= ipcomp6_err,
	.flags		= INET6_PROTO_NOPOLICY,
};

static int __init ipcomp6_init(void)
{
	if (xfrm_register_type(&ipcomp6_type, AF_INET6) < 0) {
		printk(KERN_INFO "ipcomp6 init: can't add xfrm type\n");
		return -EAGAIN;
	}
	if (inet6_add_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0) {
		printk(KERN_INFO "ipcomp6 init: can't add protocol\n");
		xfrm_unregister_type(&ipcomp6_type, AF_INET6);
		return -EAGAIN;
	}
	return 0;
}

static void __exit ipcomp6_fini(void)
{
	if (inet6_del_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0)
		printk(KERN_INFO "ipv6 ipcomp close: can't remove protocol\n");
	if (xfrm_unregister_type(&ipcomp6_type, AF_INET6) < 0)
		printk(KERN_INFO "ipv6 ipcomp close: can't remove xfrm type\n");
}

module_init(ipcomp6_init);
module_exit(ipcomp6_fini);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173");
MODULE_AUTHOR("Mitsuru KANDA <mk@linux-ipv6.org>");

MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_COMP);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173
	3	*
	4	* Copyright (C)2003 USAGI/WIDE Project
	5	*
	6	* Author Mitsuru KANDA <mk@linux-ipv6.org>
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License as published by
	10	* the Free Software Foundation; either version 2 of the License, or
	11	* (at your option) any later version.
1ab1457c	12	*
1da177e4 LT	13	* This program is distributed in the hope that it will be useful,
	14	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	* GNU General Public License for more details.
1ab1457c	17	*
1da177e4 LT	18	* You should have received a copy of the GNU General Public License
	19	* along with this program; if not, write to the Free Software
	20	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	21	*/
1ab1457c	22	/*
1da177e4 LT	23	* [Memo]
	24	*
	25	* Outbound:
1ab1457c YH	26	* The compression of IP datagram MUST be done before AH/ESP processing,
1ab1457c YH	27	* fragmentation, and the addition of Hop-by-Hop/Routing header.
1da177e4 LT	28	*
1da177e4 LT	29	* Inbound:
1ab1457c	30	* The decompression of IP datagram MUST be done after the reassembly,
1da177e4 LT	31	* AH/ESP processing.
1da177e4 LT	32	*/
1da177e4 LT	33	#include <linux/module.h>
	34	#include <net/ip.h>
	35	#include <net/xfrm.h>
	36	#include <net/ipcomp.h>
1da177e4 LT	37	#include <asm/semaphore.h>
	38	#include <linux/crypto.h>
	39	#include <linux/pfkeyv2.h>
	40	#include <linux/random.h>
	41	#include <linux/percpu.h>
	42	#include <linux/smp.h>
	43	#include <linux/list.h>
	44	#include <linux/vmalloc.h>
	45	#include <linux/rtnetlink.h>
	46	#include <net/icmp.h>
	47	#include <net/ipv6.h>
14c85021	48	#include <net/protocol.h>
1da177e4 LT	49	#include <linux/ipv6.h>
1da177e4 LT	50	#include <linux/icmpv6.h>
4a3e2f71	51	#include <linux/mutex.h>
1da177e4 LT	52
	53	struct ipcomp6_tfms {
	54	struct list_head list;
e4d5b79c	55	struct crypto_comp **tfms;
1da177e4 LT	56	int users;
	57	};
	58
4a3e2f71	59	static DEFINE_MUTEX(ipcomp6_resource_mutex);
1da177e4 LT	60	static void **ipcomp6_scratches;
	61	static int ipcomp6_scratch_users;
	62	static LIST_HEAD(ipcomp6_tfms_list);
	63
e695633e	64	static int ipcomp6_input(struct xfrm_state x, struct sk_buff skb)
1da177e4	65	{
364c6bad	66	int err = -ENOMEM;
87bdc48d	67	struct ip_comp_hdr *ipch;
1da177e4 LT	68	int plen, dlen;
	69	struct ipcomp_data *ipcd = x->data;
	70	u8 start, scratch;
e4d5b79c	71	struct crypto_comp *tfm;
1da177e4 LT	72	int cpu;
1da177e4 LT	73
364c6bad	74	if (skb_linearize_cow(skb))
1da177e4	75	goto out;
1da177e4 LT	76
	77	skb->ip_summed = CHECKSUM_NONE;
	78
	79	/* Remove ipcomp header and decompress original payload */
31a4ab93	80	ipch = (void *)skb->data;
b0e380b1	81	skb->transport_header = skb->network_header + sizeof(*ipch);
31a4ab93	82	__skb_pull(skb, sizeof(*ipch));
1da177e4 LT	83
	84	/* decompression */
	85	plen = skb->len;
	86	dlen = IPCOMP_SCRATCH_SIZE;
	87	start = skb->data;
	88
	89	cpu = get_cpu();
	90	scratch = *per_cpu_ptr(ipcomp6_scratches, cpu);
	91	tfm = *per_cpu_ptr(ipcd->tfms, cpu);
	92
	93	err = crypto_comp_decompress(tfm, start, plen, scratch, &dlen);
87bdc48d	94	if (err)
1da177e4	95	goto out_put_cpu;
1da177e4	96
87bdc48d	97	if (dlen < (plen + sizeof(*ipch))) {
1da177e4 LT	98	err = -EINVAL;
	99	goto out_put_cpu;
	100	}
	101
	102	err = pskb_expand_head(skb, 0, dlen - plen, GFP_ATOMIC);
	103	if (err) {
	104	goto out_put_cpu;
	105	}
	106
da952315 HX	107	skb->truesize += dlen - plen;
da952315 HX	108	__skb_put(skb, dlen - plen);
27d7ff46	109	skb_copy_to_linear_data(skb, scratch, dlen);
31a4ab93	110	err = ipch->nexthdr;
1da177e4	111
1da177e4 LT	112	out_put_cpu:
	113	put_cpu();
	114	out:
1da177e4 LT	115	return err;
	116	}
	117
	118	static int ipcomp6_output(struct xfrm_state x, struct sk_buff skb)
	119	{
	120	int err;
87bdc48d	121	struct ip_comp_hdr *ipch;
1da177e4 LT	122	struct ipcomp_data *ipcd = x->data;
	123	int plen, dlen;
	124	u8 start, scratch;
e4d5b79c	125	struct crypto_comp *tfm;
1da177e4	126	int cpu;
1da177e4 LT	127
1da177e4 LT	128	/* check whether datagram len is larger than threshold */
ceb1eec8	129	if (skb->len < ipcd->threshold) {
1da177e4 LT	130	goto out_ok;
	131	}
	132
364c6bad	133	if (skb_linearize_cow(skb))
1da177e4	134	goto out_ok;
1da177e4 LT	135
1da177e4 LT	136	/* compression */
ceb1eec8	137	plen = skb->len;
1da177e4	138	dlen = IPCOMP_SCRATCH_SIZE;
ceb1eec8	139	start = skb->data;
1da177e4 LT	140
	141	cpu = get_cpu();
	142	scratch = *per_cpu_ptr(ipcomp6_scratches, cpu);
	143	tfm = *per_cpu_ptr(ipcd->tfms, cpu);
	144
	145	err = crypto_comp_compress(tfm, start, plen, scratch, &dlen);
87bdc48d	146	if (err \|\| (dlen + sizeof(*ipch)) >= plen) {
1da177e4 LT	147	put_cpu();
	148	goto out_ok;
	149	}
	150	memcpy(start + sizeof(struct ip_comp_hdr), scratch, dlen);
	151	put_cpu();
ceb1eec8	152	pskb_trim(skb, dlen + sizeof(struct ip_comp_hdr));
1da177e4 LT	153
1da177e4 LT	154	/* insert ipcomp header and replace datagram */
87bdc48d	155	ipch = ip_comp_hdr(skb);
007f0211	156	ipch->nexthdr = *skb_mac_header(skb);
1da177e4 LT	157	ipch->flags = 0;
1da177e4 LT	158	ipch->cpi = htons((u16 )ntohl(x->id.spi));
007f0211	159	*skb_mac_header(skb) = IPPROTO_COMP;
1da177e4 LT	160
1da177e4 LT	161	out_ok:
ceb1eec8 HX	162	skb_push(skb, -skb_network_offset(skb));
ceb1eec8 HX	163
1da177e4 LT	164	return 0;
	165	}
	166
	167	static void ipcomp6_err(struct sk_buff skb, struct inet6_skb_parm opt,
1ab1457c	168	int type, int code, int offset, __be32 info)
1da177e4	169	{
a94cfd19	170	__be32 spi;
1da177e4	171	struct ipv6hdr iph = (struct ipv6hdr)skb->data;
87bdc48d HX	172	struct ip_comp_hdr *ipcomph =
87bdc48d HX	173	(struct ip_comp_hdr *)(skb->data + offset);
1da177e4 LT	174	struct xfrm_state *x;
	175
	176	if (type != ICMPV6_DEST_UNREACH && type != ICMPV6_PKT_TOOBIG)
	177	return;
	178
4195f814	179	spi = htonl(ntohs(ipcomph->cpi));
1da177e4 LT	180	x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, spi, IPPROTO_COMP, AF_INET6);
	181	if (!x)
	182	return;
	183
46b86a2d	184	printk(KERN_DEBUG "pmtu discovery on SA IPCOMP/%08x/" NIP6_FMT "\n",
1da177e4 LT	185	spi, NIP6(iph->daddr));
	186	xfrm_state_put(x);
	187	}
	188
	189	static struct xfrm_state ipcomp6_tunnel_create(struct xfrm_state x)
	190	{
	191	struct xfrm_state *t = NULL;
0a69452c	192	u8 mode = XFRM_MODE_TUNNEL;
1da177e4 LT	193
	194	t = xfrm_state_alloc();
	195	if (!t)
	196	goto out;
	197
	198	t->id.proto = IPPROTO_IPV6;
	199	t->id.spi = xfrm6_tunnel_alloc_spi((xfrm_address_t *)&x->props.saddr);
6abaaaae HX	200	if (!t->id.spi)
	201	goto error;
	202
1da177e4 LT	203	memcpy(t->id.daddr.a6, x->id.daddr.a6, sizeof(struct in6_addr));
	204	memcpy(&t->sel, &x->sel, sizeof(t->sel));
	205	t->props.family = AF_INET6;
0a69452c DB	206	if (x->props.mode == XFRM_MODE_BEET)
	207	mode = x->props.mode;
	208	t->props.mode = mode;
1da177e4 LT	209	memcpy(t->props.saddr.a6, x->props.saddr.a6, sizeof(struct in6_addr));
1da177e4 LT	210
72cb6962	211	if (xfrm_init_state(t))
1da177e4 LT	212	goto error;
1da177e4 LT	213
1da177e4 LT	214	atomic_set(&t->tunnel_users, 1);
	215
	216	out:
	217	return t;
	218
	219	error:
6abaaaae	220	t->km.state = XFRM_STATE_DEAD;
1da177e4	221	xfrm_state_put(t);
6abaaaae	222	t = NULL;
1da177e4 LT	223	goto out;
	224	}
	225
	226	static int ipcomp6_tunnel_attach(struct xfrm_state *x)
	227	{
	228	int err = 0;
	229	struct xfrm_state *t = NULL;
a94cfd19	230	__be32 spi;
1da177e4 LT	231
	232	spi = xfrm6_tunnel_spi_lookup((xfrm_address_t *)&x->props.saddr);
	233	if (spi)
	234	t = xfrm_state_lookup((xfrm_address_t *)&x->id.daddr,
	235	spi, IPPROTO_IPV6, AF_INET6);
	236	if (!t) {
	237	t = ipcomp6_tunnel_create(x);
	238	if (!t) {
	239	err = -EINVAL;
	240	goto out;
	241	}
	242	xfrm_state_insert(t);
	243	xfrm_state_hold(t);
	244	}
	245	x->tunnel = t;
	246	atomic_inc(&t->tunnel_users);
	247
	248	out:
	249	return err;
	250	}
	251
	252	static void ipcomp6_free_scratches(void)
	253	{
	254	int i;
	255	void **scratches;
	256
	257	if (--ipcomp6_scratch_users)
	258	return;
	259
	260	scratches = ipcomp6_scratches;
	261	if (!scratches)
	262	return;
	263
6f912042	264	for_each_possible_cpu(i) {
1da177e4	265	void scratch = per_cpu_ptr(scratches, i);
2b191bef JJ	266
2b191bef JJ	267	vfree(scratch);
1da177e4 LT	268	}
	269
	270	free_percpu(scratches);
	271	}
	272
	273	static void **ipcomp6_alloc_scratches(void)
	274	{
	275	int i;
	276	void **scratches;
	277
	278	if (ipcomp6_scratch_users++)
	279	return ipcomp6_scratches;
	280
	281	scratches = alloc_percpu(void *);
	282	if (!scratches)
	283	return NULL;
	284
	285	ipcomp6_scratches = scratches;
	286
6f912042	287	for_each_possible_cpu(i) {
1da177e4 LT	288	void *scratch = vmalloc(IPCOMP_SCRATCH_SIZE);
	289	if (!scratch)
	290	return NULL;
	291	*per_cpu_ptr(scratches, i) = scratch;
	292	}
	293
	294	return scratches;
	295	}
	296
e4d5b79c	297	static void ipcomp6_free_tfms(struct crypto_comp **tfms)
1da177e4 LT	298	{
	299	struct ipcomp6_tfms *pos;
	300	int cpu;
	301
	302	list_for_each_entry(pos, &ipcomp6_tfms_list, list) {
	303	if (pos->tfms == tfms)
	304	break;
	305	}
	306
	307	BUG_TRAP(pos);
	308
	309	if (--pos->users)
	310	return;
	311
	312	list_del(&pos->list);
	313	kfree(pos);
	314
	315	if (!tfms)
	316	return;
	317
6f912042	318	for_each_possible_cpu(cpu) {
e4d5b79c HX	319	struct crypto_comp tfm = per_cpu_ptr(tfms, cpu);
e4d5b79c HX	320	crypto_free_comp(tfm);
1da177e4 LT	321	}
	322	free_percpu(tfms);
	323	}
	324
e4d5b79c	325	static struct crypto_comp *ipcomp6_alloc_tfms(const char alg_name)
1da177e4 LT	326	{
1da177e4 LT	327	struct ipcomp6_tfms *pos;
e4d5b79c	328	struct crypto_comp **tfms;
1da177e4 LT	329	int cpu;
	330
	331	/* This can be any valid CPU ID so we don't need locking. */
6fc8b9e7	332	cpu = raw_smp_processor_id();
1da177e4 LT	333
1da177e4 LT	334	list_for_each_entry(pos, &ipcomp6_tfms_list, list) {
e4d5b79c	335	struct crypto_comp *tfm;
1da177e4 LT	336
	337	tfms = pos->tfms;
	338	tfm = *per_cpu_ptr(tfms, cpu);
	339
e4d5b79c	340	if (!strcmp(crypto_comp_name(tfm), alg_name)) {
1da177e4 LT	341	pos->users++;
	342	return tfms;
	343	}
	344	}
	345
	346	pos = kmalloc(sizeof(*pos), GFP_KERNEL);
	347	if (!pos)
	348	return NULL;
	349
	350	pos->users = 1;
	351	INIT_LIST_HEAD(&pos->list);
	352	list_add(&pos->list, &ipcomp6_tfms_list);
	353
e4d5b79c	354	pos->tfms = tfms = alloc_percpu(struct crypto_comp *);
1da177e4 LT	355	if (!tfms)
	356	goto error;
	357
6f912042	358	for_each_possible_cpu(cpu) {
e4d5b79c HX	359	struct crypto_comp *tfm = crypto_alloc_comp(alg_name, 0,
e4d5b79c HX	360	CRYPTO_ALG_ASYNC);
1da177e4 LT	361	if (!tfm)
	362	goto error;
	363	*per_cpu_ptr(tfms, cpu) = tfm;
	364	}
	365
	366	return tfms;
	367
	368	error:
	369	ipcomp6_free_tfms(tfms);
	370	return NULL;
	371	}
	372
	373	static void ipcomp6_free_data(struct ipcomp_data *ipcd)
	374	{
	375	if (ipcd->tfms)
	376	ipcomp6_free_tfms(ipcd->tfms);
	377	ipcomp6_free_scratches();
	378	}
	379
	380	static void ipcomp6_destroy(struct xfrm_state *x)
	381	{
	382	struct ipcomp_data *ipcd = x->data;
	383	if (!ipcd)
	384	return;
	385	xfrm_state_delete_tunnel(x);
4a3e2f71	386	mutex_lock(&ipcomp6_resource_mutex);
1da177e4	387	ipcomp6_free_data(ipcd);
4a3e2f71	388	mutex_unlock(&ipcomp6_resource_mutex);
1da177e4 LT	389	kfree(ipcd);
	390
	391	xfrm6_tunnel_free_spi((xfrm_address_t *)&x->props.saddr);
	392	}
	393
72cb6962	394	static int ipcomp6_init_state(struct xfrm_state *x)
1da177e4 LT	395	{
	396	int err;
	397	struct ipcomp_data *ipcd;
	398	struct xfrm_algo_desc *calg_desc;
	399
	400	err = -EINVAL;
	401	if (!x->calg)
	402	goto out;
	403
	404	if (x->encap)
	405	goto out;
	406
	407	err = -ENOMEM;
0c600eda	408	ipcd = kzalloc(sizeof(*ipcd), GFP_KERNEL);
1da177e4 LT	409	if (!ipcd)
	410	goto out;
	411
1da177e4	412	x->props.header_len = 0;
ca68145f HX	413	switch (x->props.mode) {
	414	case XFRM_MODE_BEET:
	415	case XFRM_MODE_TRANSPORT:
	416	break;
	417	case XFRM_MODE_TUNNEL:
1da177e4	418	x->props.header_len += sizeof(struct ipv6hdr);
ca68145f HX	419	default:
	420	goto error;
	421	}
1ab1457c	422
4a3e2f71	423	mutex_lock(&ipcomp6_resource_mutex);
1da177e4 LT	424	if (!ipcomp6_alloc_scratches())
	425	goto error;
	426
	427	ipcd->tfms = ipcomp6_alloc_tfms(x->calg->alg_name);
	428	if (!ipcd->tfms)
	429	goto error;
4a3e2f71	430	mutex_unlock(&ipcomp6_resource_mutex);
1da177e4	431
7e49e6de	432	if (x->props.mode == XFRM_MODE_TUNNEL) {
1da177e4 LT	433	err = ipcomp6_tunnel_attach(x);
	434	if (err)
	435	goto error_tunnel;
	436	}
	437
	438	calg_desc = xfrm_calg_get_byname(x->calg->alg_name, 0);
	439	BUG_ON(!calg_desc);
	440	ipcd->threshold = calg_desc->uinfo.comp.threshold;
	441	x->data = ipcd;
	442	err = 0;
	443	out:
	444	return err;
	445	error_tunnel:
4a3e2f71	446	mutex_lock(&ipcomp6_resource_mutex);
1da177e4 LT	447	error:
1da177e4 LT	448	ipcomp6_free_data(ipcd);
4a3e2f71	449	mutex_unlock(&ipcomp6_resource_mutex);
1da177e4 LT	450	kfree(ipcd);
	451
	452	goto out;
	453	}
	454
1ab1457c	455	static struct xfrm_type ipcomp6_type =
1da177e4 LT	456	{
	457	.description = "IPCOMP6",
	458	.owner = THIS_MODULE,
	459	.proto = IPPROTO_COMP,
	460	.init_state = ipcomp6_init_state,
	461	.destructor = ipcomp6_destroy,
	462	.input = ipcomp6_input,
	463	.output = ipcomp6_output,
aee5adb4	464	.hdr_offset = xfrm6_find_1stfragopt,
1da177e4 LT	465	};
1da177e4 LT	466
1ab1457c	467	static struct inet6_protocol ipcomp6_protocol =
1da177e4 LT	468	{
	469	.handler = xfrm6_rcv,
	470	.err_handler = ipcomp6_err,
	471	.flags = INET6_PROTO_NOPOLICY,
	472	};
	473
	474	static int __init ipcomp6_init(void)
	475	{
	476	if (xfrm_register_type(&ipcomp6_type, AF_INET6) < 0) {
	477	printk(KERN_INFO "ipcomp6 init: can't add xfrm type\n");
	478	return -EAGAIN;
	479	}
	480	if (inet6_add_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0) {
	481	printk(KERN_INFO "ipcomp6 init: can't add protocol\n");
	482	xfrm_unregister_type(&ipcomp6_type, AF_INET6);
	483	return -EAGAIN;
	484	}
	485	return 0;
	486	}
	487
	488	static void __exit ipcomp6_fini(void)
	489	{
1ab1457c	490	if (inet6_del_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0)
1da177e4 LT	491	printk(KERN_INFO "ipv6 ipcomp close: can't remove protocol\n");
	492	if (xfrm_unregister_type(&ipcomp6_type, AF_INET6) < 0)
	493	printk(KERN_INFO "ipv6 ipcomp close: can't remove xfrm type\n");
	494	}
	495
	496	module_init(ipcomp6_init);
	497	module_exit(ipcomp6_fini);
	498	MODULE_LICENSE("GPL");
	499	MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173");
	500	MODULE_AUTHOR("Mitsuru KANDA <mk@linux-ipv6.org>");
	501
d3d6dd3a	502	MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_COMP);