[deliverable/linux.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/scatterlist.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 ipv6_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) {
		err = -EINVAL;
		goto out_put_cpu;
	}

	if (dlen < (plen + sizeof(struct ipv6_comp_hdr))) {
		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 ipv6hdr *top_iph;
	struct ipv6_comp_hdr *ipch;
	struct ipcomp_data *ipcd = x->data;
	int plen, dlen;
	u8 *start, *scratch;
	struct crypto_comp *tfm;
	int cpu;
	int hdr_len;

	skb_push(skb, -skb_network_offset(skb));
	hdr_len = skb_transport_offset(skb);

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

	if (skb_linearize_cow(skb))
		goto out_ok;

	/* compression */
	plen = skb->len - hdr_len;
	dlen = IPCOMP_SCRATCH_SIZE;
	start = skb_transport_header(skb);

	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(struct ipv6_comp_hdr)) >= plen) {
		put_cpu();
		goto out_ok;
	}
	memcpy(start + sizeof(struct ip_comp_hdr), scratch, dlen);
	put_cpu();
	pskb_trim(skb, hdr_len + dlen + sizeof(struct ip_comp_hdr));

	/* insert ipcomp header and replace datagram */
	top_iph = ipv6_hdr(skb);

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

	ipch = (struct ipv6_comp_hdr *)start;
	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:
	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 ipv6_comp_hdr *ipcomph = (struct ipv6_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;
	if (x->props.mode == XFRM_MODE_TUNNEL)
		x->props.header_len += sizeof(struct ipv6hdr);

	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>
	37	#include <asm/scatterlist.h>
	38	#include <asm/semaphore.h>
	39	#include <linux/crypto.h>
	40	#include <linux/pfkeyv2.h>
	41	#include <linux/random.h>
	42	#include <linux/percpu.h>
	43	#include <linux/smp.h>
	44	#include <linux/list.h>
	45	#include <linux/vmalloc.h>
	46	#include <linux/rtnetlink.h>
	47	#include <net/icmp.h>
	48	#include <net/ipv6.h>
14c85021	49	#include <net/protocol.h>
1da177e4 LT	50	#include <linux/ipv6.h>
1da177e4 LT	51	#include <linux/icmpv6.h>
4a3e2f71	52	#include <linux/mutex.h>
1da177e4 LT	53
	54	struct ipcomp6_tfms {
	55	struct list_head list;
e4d5b79c	56	struct crypto_comp **tfms;
1da177e4 LT	57	int users;
	58	};
	59
4a3e2f71	60	static DEFINE_MUTEX(ipcomp6_resource_mutex);
1da177e4 LT	61	static void **ipcomp6_scratches;
	62	static int ipcomp6_scratch_users;
	63	static LIST_HEAD(ipcomp6_tfms_list);
	64
e695633e	65	static int ipcomp6_input(struct xfrm_state x, struct sk_buff skb)
1da177e4	66	{
364c6bad	67	int err = -ENOMEM;
31a4ab93	68	struct ipv6_comp_hdr *ipch;
1da177e4 LT	69	int plen, dlen;
	70	struct ipcomp_data *ipcd = x->data;
	71	u8 start, scratch;
e4d5b79c	72	struct crypto_comp *tfm;
1da177e4 LT	73	int cpu;
1da177e4 LT	74
364c6bad	75	if (skb_linearize_cow(skb))
1da177e4	76	goto out;
1da177e4 LT	77
	78	skb->ip_summed = CHECKSUM_NONE;
	79
	80	/* Remove ipcomp header and decompress original payload */
31a4ab93	81	ipch = (void *)skb->data;
b0e380b1	82	skb->transport_header = skb->network_header + sizeof(*ipch);
31a4ab93	83	__skb_pull(skb, sizeof(*ipch));
1da177e4 LT	84
	85	/* decompression */
	86	plen = skb->len;
	87	dlen = IPCOMP_SCRATCH_SIZE;
	88	start = skb->data;
	89
	90	cpu = get_cpu();
	91	scratch = *per_cpu_ptr(ipcomp6_scratches, cpu);
	92	tfm = *per_cpu_ptr(ipcd->tfms, cpu);
	93
	94	err = crypto_comp_decompress(tfm, start, plen, scratch, &dlen);
	95	if (err) {
	96	err = -EINVAL;
	97	goto out_put_cpu;
	98	}
	99
	100	if (dlen < (plen + sizeof(struct ipv6_comp_hdr))) {
	101	err = -EINVAL;
	102	goto out_put_cpu;
	103	}
	104
	105	err = pskb_expand_head(skb, 0, dlen - plen, GFP_ATOMIC);
	106	if (err) {
	107	goto out_put_cpu;
	108	}
	109
da952315 HX	110	skb->truesize += dlen - plen;
da952315 HX	111	__skb_put(skb, dlen - plen);
27d7ff46	112	skb_copy_to_linear_data(skb, scratch, dlen);
31a4ab93	113	err = ipch->nexthdr;
1da177e4	114
1da177e4 LT	115	out_put_cpu:
	116	put_cpu();
	117	out:
1da177e4 LT	118	return err;
	119	}
	120
	121	static int ipcomp6_output(struct xfrm_state x, struct sk_buff skb)
	122	{
	123	int err;
	124	struct ipv6hdr *top_iph;
1da177e4 LT	125	struct ipv6_comp_hdr *ipch;
	126	struct ipcomp_data *ipcd = x->data;
	127	int plen, dlen;
	128	u8 start, scratch;
e4d5b79c	129	struct crypto_comp *tfm;
1da177e4	130	int cpu;
7b277b1a HX	131	int hdr_len;
	132
	133	skb_push(skb, -skb_network_offset(skb));
	134	hdr_len = skb_transport_offset(skb);
1da177e4 LT	135
	136	/* check whether datagram len is larger than threshold */
	137	if ((skb->len - hdr_len) < ipcd->threshold) {
	138	goto out_ok;
	139	}
	140
364c6bad	141	if (skb_linearize_cow(skb))
1da177e4	142	goto out_ok;
1da177e4 LT	143
	144	/* compression */
	145	plen = skb->len - hdr_len;
	146	dlen = IPCOMP_SCRATCH_SIZE;
9c70220b	147	start = skb_transport_header(skb);
1da177e4 LT	148
	149	cpu = get_cpu();
	150	scratch = *per_cpu_ptr(ipcomp6_scratches, cpu);
	151	tfm = *per_cpu_ptr(ipcd->tfms, cpu);
	152
	153	err = crypto_comp_compress(tfm, start, plen, scratch, &dlen);
	154	if (err \|\| (dlen + sizeof(struct ipv6_comp_hdr)) >= plen) {
	155	put_cpu();
	156	goto out_ok;
	157	}
	158	memcpy(start + sizeof(struct ip_comp_hdr), scratch, dlen);
	159	put_cpu();
	160	pskb_trim(skb, hdr_len + dlen + sizeof(struct ip_comp_hdr));
	161
	162	/* insert ipcomp header and replace datagram */
007f0211	163	top_iph = ipv6_hdr(skb);
1da177e4 LT	164
	165	top_iph->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
	166
	167	ipch = (struct ipv6_comp_hdr *)start;
007f0211	168	ipch->nexthdr = *skb_mac_header(skb);
1da177e4 LT	169	ipch->flags = 0;
1da177e4 LT	170	ipch->cpi = htons((u16 )ntohl(x->id.spi));
007f0211	171	*skb_mac_header(skb) = IPPROTO_COMP;
1da177e4 LT	172
	173	out_ok:
	174	return 0;
	175	}
	176
	177	static void ipcomp6_err(struct sk_buff skb, struct inet6_skb_parm opt,
1ab1457c	178	int type, int code, int offset, __be32 info)
1da177e4	179	{
a94cfd19	180	__be32 spi;
1da177e4 LT	181	struct ipv6hdr iph = (struct ipv6hdr)skb->data;
	182	struct ipv6_comp_hdr ipcomph = (struct ipv6_comp_hdr)(skb->data+offset);
	183	struct xfrm_state *x;
	184
	185	if (type != ICMPV6_DEST_UNREACH && type != ICMPV6_PKT_TOOBIG)
	186	return;
	187
4195f814	188	spi = htonl(ntohs(ipcomph->cpi));
1da177e4 LT	189	x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, spi, IPPROTO_COMP, AF_INET6);
	190	if (!x)
	191	return;
	192
46b86a2d	193	printk(KERN_DEBUG "pmtu discovery on SA IPCOMP/%08x/" NIP6_FMT "\n",
1da177e4 LT	194	spi, NIP6(iph->daddr));
	195	xfrm_state_put(x);
	196	}
	197
	198	static struct xfrm_state ipcomp6_tunnel_create(struct xfrm_state x)
	199	{
	200	struct xfrm_state *t = NULL;
0a69452c	201	u8 mode = XFRM_MODE_TUNNEL;
1da177e4 LT	202
	203	t = xfrm_state_alloc();
	204	if (!t)
	205	goto out;
	206
	207	t->id.proto = IPPROTO_IPV6;
	208	t->id.spi = xfrm6_tunnel_alloc_spi((xfrm_address_t *)&x->props.saddr);
6abaaaae HX	209	if (!t->id.spi)
	210	goto error;
	211
1da177e4 LT	212	memcpy(t->id.daddr.a6, x->id.daddr.a6, sizeof(struct in6_addr));
	213	memcpy(&t->sel, &x->sel, sizeof(t->sel));
	214	t->props.family = AF_INET6;
0a69452c DB	215	if (x->props.mode == XFRM_MODE_BEET)
	216	mode = x->props.mode;
	217	t->props.mode = mode;
1da177e4 LT	218	memcpy(t->props.saddr.a6, x->props.saddr.a6, sizeof(struct in6_addr));
1da177e4 LT	219
72cb6962	220	if (xfrm_init_state(t))
1da177e4 LT	221	goto error;
1da177e4 LT	222
1da177e4 LT	223	atomic_set(&t->tunnel_users, 1);
	224
	225	out:
	226	return t;
	227
	228	error:
6abaaaae	229	t->km.state = XFRM_STATE_DEAD;
1da177e4	230	xfrm_state_put(t);
6abaaaae	231	t = NULL;
1da177e4 LT	232	goto out;
	233	}
	234
	235	static int ipcomp6_tunnel_attach(struct xfrm_state *x)
	236	{
	237	int err = 0;
	238	struct xfrm_state *t = NULL;
a94cfd19	239	__be32 spi;
1da177e4 LT	240
	241	spi = xfrm6_tunnel_spi_lookup((xfrm_address_t *)&x->props.saddr);
	242	if (spi)
	243	t = xfrm_state_lookup((xfrm_address_t *)&x->id.daddr,
	244	spi, IPPROTO_IPV6, AF_INET6);
	245	if (!t) {
	246	t = ipcomp6_tunnel_create(x);
	247	if (!t) {
	248	err = -EINVAL;
	249	goto out;
	250	}
	251	xfrm_state_insert(t);
	252	xfrm_state_hold(t);
	253	}
	254	x->tunnel = t;
	255	atomic_inc(&t->tunnel_users);
	256
	257	out:
	258	return err;
	259	}
	260
	261	static void ipcomp6_free_scratches(void)
	262	{
	263	int i;
	264	void **scratches;
	265
	266	if (--ipcomp6_scratch_users)
	267	return;
	268
	269	scratches = ipcomp6_scratches;
	270	if (!scratches)
	271	return;
	272
6f912042	273	for_each_possible_cpu(i) {
1da177e4	274	void scratch = per_cpu_ptr(scratches, i);
2b191bef JJ	275
2b191bef JJ	276	vfree(scratch);
1da177e4 LT	277	}
	278
	279	free_percpu(scratches);
	280	}
	281
	282	static void **ipcomp6_alloc_scratches(void)
	283	{
	284	int i;
	285	void **scratches;
	286
	287	if (ipcomp6_scratch_users++)
	288	return ipcomp6_scratches;
	289
	290	scratches = alloc_percpu(void *);
	291	if (!scratches)
	292	return NULL;
	293
	294	ipcomp6_scratches = scratches;
	295
6f912042	296	for_each_possible_cpu(i) {
1da177e4 LT	297	void *scratch = vmalloc(IPCOMP_SCRATCH_SIZE);
	298	if (!scratch)
	299	return NULL;
	300	*per_cpu_ptr(scratches, i) = scratch;
	301	}
	302
	303	return scratches;
	304	}
	305
e4d5b79c	306	static void ipcomp6_free_tfms(struct crypto_comp **tfms)
1da177e4 LT	307	{
	308	struct ipcomp6_tfms *pos;
	309	int cpu;
	310
	311	list_for_each_entry(pos, &ipcomp6_tfms_list, list) {
	312	if (pos->tfms == tfms)
	313	break;
	314	}
	315
	316	BUG_TRAP(pos);
	317
	318	if (--pos->users)
	319	return;
	320
	321	list_del(&pos->list);
	322	kfree(pos);
	323
	324	if (!tfms)
	325	return;
	326
6f912042	327	for_each_possible_cpu(cpu) {
e4d5b79c HX	328	struct crypto_comp tfm = per_cpu_ptr(tfms, cpu);
e4d5b79c HX	329	crypto_free_comp(tfm);
1da177e4 LT	330	}
	331	free_percpu(tfms);
	332	}
	333
e4d5b79c	334	static struct crypto_comp *ipcomp6_alloc_tfms(const char alg_name)
1da177e4 LT	335	{
1da177e4 LT	336	struct ipcomp6_tfms *pos;
e4d5b79c	337	struct crypto_comp **tfms;
1da177e4 LT	338	int cpu;
	339
	340	/* This can be any valid CPU ID so we don't need locking. */
6fc8b9e7	341	cpu = raw_smp_processor_id();
1da177e4 LT	342
1da177e4 LT	343	list_for_each_entry(pos, &ipcomp6_tfms_list, list) {
e4d5b79c	344	struct crypto_comp *tfm;
1da177e4 LT	345
	346	tfms = pos->tfms;
	347	tfm = *per_cpu_ptr(tfms, cpu);
	348
e4d5b79c	349	if (!strcmp(crypto_comp_name(tfm), alg_name)) {
1da177e4 LT	350	pos->users++;
	351	return tfms;
	352	}
	353	}
	354
	355	pos = kmalloc(sizeof(*pos), GFP_KERNEL);
	356	if (!pos)
	357	return NULL;
	358
	359	pos->users = 1;
	360	INIT_LIST_HEAD(&pos->list);
	361	list_add(&pos->list, &ipcomp6_tfms_list);
	362
e4d5b79c	363	pos->tfms = tfms = alloc_percpu(struct crypto_comp *);
1da177e4 LT	364	if (!tfms)
	365	goto error;
	366
6f912042	367	for_each_possible_cpu(cpu) {
e4d5b79c HX	368	struct crypto_comp *tfm = crypto_alloc_comp(alg_name, 0,
e4d5b79c HX	369	CRYPTO_ALG_ASYNC);
1da177e4 LT	370	if (!tfm)
	371	goto error;
	372	*per_cpu_ptr(tfms, cpu) = tfm;
	373	}
	374
	375	return tfms;
	376
	377	error:
	378	ipcomp6_free_tfms(tfms);
	379	return NULL;
	380	}
	381
	382	static void ipcomp6_free_data(struct ipcomp_data *ipcd)
	383	{
	384	if (ipcd->tfms)
	385	ipcomp6_free_tfms(ipcd->tfms);
	386	ipcomp6_free_scratches();
	387	}
	388
	389	static void ipcomp6_destroy(struct xfrm_state *x)
	390	{
	391	struct ipcomp_data *ipcd = x->data;
	392	if (!ipcd)
	393	return;
	394	xfrm_state_delete_tunnel(x);
4a3e2f71	395	mutex_lock(&ipcomp6_resource_mutex);
1da177e4	396	ipcomp6_free_data(ipcd);
4a3e2f71	397	mutex_unlock(&ipcomp6_resource_mutex);
1da177e4 LT	398	kfree(ipcd);
	399
	400	xfrm6_tunnel_free_spi((xfrm_address_t *)&x->props.saddr);
	401	}
	402
72cb6962	403	static int ipcomp6_init_state(struct xfrm_state *x)
1da177e4 LT	404	{
	405	int err;
	406	struct ipcomp_data *ipcd;
	407	struct xfrm_algo_desc *calg_desc;
	408
	409	err = -EINVAL;
	410	if (!x->calg)
	411	goto out;
	412
	413	if (x->encap)
	414	goto out;
	415
	416	err = -ENOMEM;
0c600eda	417	ipcd = kzalloc(sizeof(*ipcd), GFP_KERNEL);
1da177e4 LT	418	if (!ipcd)
	419	goto out;
	420
1da177e4	421	x->props.header_len = 0;
7e49e6de	422	if (x->props.mode == XFRM_MODE_TUNNEL)
1da177e4	423	x->props.header_len += sizeof(struct ipv6hdr);
1ab1457c	424
4a3e2f71	425	mutex_lock(&ipcomp6_resource_mutex);
1da177e4 LT	426	if (!ipcomp6_alloc_scratches())
	427	goto error;
	428
	429	ipcd->tfms = ipcomp6_alloc_tfms(x->calg->alg_name);
	430	if (!ipcd->tfms)
	431	goto error;
4a3e2f71	432	mutex_unlock(&ipcomp6_resource_mutex);
1da177e4	433
7e49e6de	434	if (x->props.mode == XFRM_MODE_TUNNEL) {
1da177e4 LT	435	err = ipcomp6_tunnel_attach(x);
	436	if (err)
	437	goto error_tunnel;
	438	}
	439
	440	calg_desc = xfrm_calg_get_byname(x->calg->alg_name, 0);
	441	BUG_ON(!calg_desc);
	442	ipcd->threshold = calg_desc->uinfo.comp.threshold;
	443	x->data = ipcd;
	444	err = 0;
	445	out:
	446	return err;
	447	error_tunnel:
4a3e2f71	448	mutex_lock(&ipcomp6_resource_mutex);
1da177e4 LT	449	error:
1da177e4 LT	450	ipcomp6_free_data(ipcd);
4a3e2f71	451	mutex_unlock(&ipcomp6_resource_mutex);
1da177e4 LT	452	kfree(ipcd);
	453
	454	goto out;
	455	}
	456
1ab1457c	457	static struct xfrm_type ipcomp6_type =
1da177e4 LT	458	{
	459	.description = "IPCOMP6",
	460	.owner = THIS_MODULE,
	461	.proto = IPPROTO_COMP,
	462	.init_state = ipcomp6_init_state,
	463	.destructor = ipcomp6_destroy,
	464	.input = ipcomp6_input,
	465	.output = ipcomp6_output,
aee5adb4	466	.hdr_offset = xfrm6_find_1stfragopt,
1da177e4 LT	467	};
1da177e4 LT	468
1ab1457c	469	static struct inet6_protocol ipcomp6_protocol =
1da177e4 LT	470	{
	471	.handler = xfrm6_rcv,
	472	.err_handler = ipcomp6_err,
	473	.flags = INET6_PROTO_NOPOLICY,
	474	};
	475
	476	static int __init ipcomp6_init(void)
	477	{
	478	if (xfrm_register_type(&ipcomp6_type, AF_INET6) < 0) {
	479	printk(KERN_INFO "ipcomp6 init: can't add xfrm type\n");
	480	return -EAGAIN;
	481	}
	482	if (inet6_add_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0) {
	483	printk(KERN_INFO "ipcomp6 init: can't add protocol\n");
	484	xfrm_unregister_type(&ipcomp6_type, AF_INET6);
	485	return -EAGAIN;
	486	}
	487	return 0;
	488	}
	489
	490	static void __exit ipcomp6_fini(void)
	491	{
1ab1457c	492	if (inet6_del_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0)
1da177e4 LT	493	printk(KERN_INFO "ipv6 ipcomp close: can't remove protocol\n");
	494	if (xfrm_unregister_type(&ipcomp6_type, AF_INET6) < 0)
	495	printk(KERN_INFO "ipv6 ipcomp close: can't remove xfrm type\n");
	496	}
	497
	498	module_init(ipcomp6_init);
	499	module_exit(ipcomp6_fini);
	500	MODULE_LICENSE("GPL");
	501	MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173");
	502	MODULE_AUTHOR("Mitsuru KANDA <mk@linux-ipv6.org>");
	503
d3d6dd3a	504	MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_COMP);