[net-next-2.6.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 ipv6hdr *iph;
	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 */
	iph = ipv6_hdr(skb);
	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);
	memcpy(skb->data, 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_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 = (struct ipv6hdr *)skb->data;

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

	ipch = (struct ipv6_comp_hdr *)start;
	ipch->nexthdr = *skb_network_header(skb);
	ipch->flags = 0;
	ipch->cpi = htons((u16 )ntohl(x->id.spi));
	*skb_network_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>");
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;
1da177e4	68	struct ipv6hdr *iph;
31a4ab93	69	struct ipv6_comp_hdr *ipch;
1da177e4 LT	70	int plen, dlen;
	71	struct ipcomp_data *ipcd = x->data;
	72	u8 start, scratch;
e4d5b79c	73	struct crypto_comp *tfm;
1da177e4 LT	74	int cpu;
1da177e4 LT	75
364c6bad	76	if (skb_linearize_cow(skb))
1da177e4	77	goto out;
1da177e4 LT	78
	79	skb->ip_summed = CHECKSUM_NONE;
	80
	81	/* Remove ipcomp header and decompress original payload */
0660e03f	82	iph = ipv6_hdr(skb);
31a4ab93	83	ipch = (void *)skb->data;
b0e380b1	84	skb->transport_header = skb->network_header + sizeof(*ipch);
31a4ab93	85	__skb_pull(skb, sizeof(*ipch));
1da177e4 LT	86
	87	/* decompression */
	88	plen = skb->len;
	89	dlen = IPCOMP_SCRATCH_SIZE;
	90	start = skb->data;
	91
	92	cpu = get_cpu();
	93	scratch = *per_cpu_ptr(ipcomp6_scratches, cpu);
	94	tfm = *per_cpu_ptr(ipcd->tfms, cpu);
	95
	96	err = crypto_comp_decompress(tfm, start, plen, scratch, &dlen);
	97	if (err) {
	98	err = -EINVAL;
	99	goto out_put_cpu;
	100	}
	101
	102	if (dlen < (plen + sizeof(struct ipv6_comp_hdr))) {
	103	err = -EINVAL;
	104	goto out_put_cpu;
	105	}
	106
	107	err = pskb_expand_head(skb, 0, dlen - plen, GFP_ATOMIC);
	108	if (err) {
	109	goto out_put_cpu;
	110	}
	111
da952315 HX	112	skb->truesize += dlen - plen;
da952315 HX	113	__skb_put(skb, dlen - plen);
1da177e4	114	memcpy(skb->data, scratch, dlen);
31a4ab93	115	err = ipch->nexthdr;
1da177e4	116
1da177e4 LT	117	out_put_cpu:
	118	put_cpu();
	119	out:
1da177e4 LT	120	return err;
	121	}
	122
	123	static int ipcomp6_output(struct xfrm_state x, struct sk_buff skb)
	124	{
	125	int err;
	126	struct ipv6hdr *top_iph;
1da177e4 LT	127	struct ipv6_comp_hdr *ipch;
	128	struct ipcomp_data *ipcd = x->data;
	129	int plen, dlen;
	130	u8 start, scratch;
e4d5b79c	131	struct crypto_comp *tfm;
1da177e4	132	int cpu;
ea2ae17d	133	int hdr_len = skb_transport_offset(skb);
1da177e4 LT	134
	135	/* check whether datagram len is larger than threshold */
	136	if ((skb->len - hdr_len) < ipcd->threshold) {
	137	goto out_ok;
	138	}
	139
364c6bad	140	if (skb_linearize_cow(skb))
1da177e4	141	goto out_ok;
1da177e4 LT	142
	143	/* compression */
	144	plen = skb->len - hdr_len;
	145	dlen = IPCOMP_SCRATCH_SIZE;
9c70220b	146	start = skb_transport_header(skb);
1da177e4 LT	147
	148	cpu = get_cpu();
	149	scratch = *per_cpu_ptr(ipcomp6_scratches, cpu);
	150	tfm = *per_cpu_ptr(ipcd->tfms, cpu);
	151
	152	err = crypto_comp_compress(tfm, start, plen, scratch, &dlen);
	153	if (err \|\| (dlen + sizeof(struct ipv6_comp_hdr)) >= plen) {
	154	put_cpu();
	155	goto out_ok;
	156	}
	157	memcpy(start + sizeof(struct ip_comp_hdr), scratch, dlen);
	158	put_cpu();
	159	pskb_trim(skb, hdr_len + dlen + sizeof(struct ip_comp_hdr));
	160
	161	/* insert ipcomp header and replace datagram */
	162	top_iph = (struct ipv6hdr *)skb->data;
	163
	164	top_iph->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
	165
	166	ipch = (struct ipv6_comp_hdr *)start;
d56f90a7	167	ipch->nexthdr = *skb_network_header(skb);
1da177e4 LT	168	ipch->flags = 0;
1da177e4 LT	169	ipch->cpi = htons((u16 )ntohl(x->id.spi));
d56f90a7	170	*skb_network_header(skb) = IPPROTO_COMP;
1da177e4 LT	171
	172	out_ok:
	173	return 0;
	174	}
	175
	176	static void ipcomp6_err(struct sk_buff skb, struct inet6_skb_parm opt,
1ab1457c	177	int type, int code, int offset, __be32 info)
1da177e4	178	{
a94cfd19	179	__be32 spi;
1da177e4 LT	180	struct ipv6hdr iph = (struct ipv6hdr)skb->data;
	181	struct ipv6_comp_hdr ipcomph = (struct ipv6_comp_hdr)(skb->data+offset);
	182	struct xfrm_state *x;
	183
	184	if (type != ICMPV6_DEST_UNREACH && type != ICMPV6_PKT_TOOBIG)
	185	return;
	186
4195f814	187	spi = htonl(ntohs(ipcomph->cpi));
1da177e4 LT	188	x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, spi, IPPROTO_COMP, AF_INET6);
	189	if (!x)
	190	return;
	191
46b86a2d	192	printk(KERN_DEBUG "pmtu discovery on SA IPCOMP/%08x/" NIP6_FMT "\n",
1da177e4 LT	193	spi, NIP6(iph->daddr));
	194	xfrm_state_put(x);
	195	}
	196
	197	static struct xfrm_state ipcomp6_tunnel_create(struct xfrm_state x)
	198	{
	199	struct xfrm_state *t = NULL;
0a69452c	200	u8 mode = XFRM_MODE_TUNNEL;
1da177e4 LT	201
	202	t = xfrm_state_alloc();
	203	if (!t)
	204	goto out;
	205
	206	t->id.proto = IPPROTO_IPV6;
	207	t->id.spi = xfrm6_tunnel_alloc_spi((xfrm_address_t *)&x->props.saddr);
6abaaaae HX	208	if (!t->id.spi)
	209	goto error;
	210
1da177e4 LT	211	memcpy(t->id.daddr.a6, x->id.daddr.a6, sizeof(struct in6_addr));
	212	memcpy(&t->sel, &x->sel, sizeof(t->sel));
	213	t->props.family = AF_INET6;
0a69452c DB	214	if (x->props.mode == XFRM_MODE_BEET)
	215	mode = x->props.mode;
	216	t->props.mode = mode;
1da177e4 LT	217	memcpy(t->props.saddr.a6, x->props.saddr.a6, sizeof(struct in6_addr));
1da177e4 LT	218
72cb6962	219	if (xfrm_init_state(t))
1da177e4 LT	220	goto error;
1da177e4 LT	221
1da177e4 LT	222	atomic_set(&t->tunnel_users, 1);
	223
	224	out:
	225	return t;
	226
	227	error:
6abaaaae	228	t->km.state = XFRM_STATE_DEAD;
1da177e4	229	xfrm_state_put(t);
6abaaaae	230	t = NULL;
1da177e4 LT	231	goto out;
	232	}
	233
	234	static int ipcomp6_tunnel_attach(struct xfrm_state *x)
	235	{
	236	int err = 0;
	237	struct xfrm_state *t = NULL;
a94cfd19	238	__be32 spi;
1da177e4 LT	239
	240	spi = xfrm6_tunnel_spi_lookup((xfrm_address_t *)&x->props.saddr);
	241	if (spi)
	242	t = xfrm_state_lookup((xfrm_address_t *)&x->id.daddr,
	243	spi, IPPROTO_IPV6, AF_INET6);
	244	if (!t) {
	245	t = ipcomp6_tunnel_create(x);
	246	if (!t) {
	247	err = -EINVAL;
	248	goto out;
	249	}
	250	xfrm_state_insert(t);
	251	xfrm_state_hold(t);
	252	}
	253	x->tunnel = t;
	254	atomic_inc(&t->tunnel_users);
	255
	256	out:
	257	return err;
	258	}
	259
	260	static void ipcomp6_free_scratches(void)
	261	{
	262	int i;
	263	void **scratches;
	264
	265	if (--ipcomp6_scratch_users)
	266	return;
	267
	268	scratches = ipcomp6_scratches;
	269	if (!scratches)
	270	return;
	271
6f912042	272	for_each_possible_cpu(i) {
1da177e4	273	void scratch = per_cpu_ptr(scratches, i);
2b191bef JJ	274
2b191bef JJ	275	vfree(scratch);
1da177e4 LT	276	}
	277
	278	free_percpu(scratches);
	279	}
	280
	281	static void **ipcomp6_alloc_scratches(void)
	282	{
	283	int i;
	284	void **scratches;
	285
	286	if (ipcomp6_scratch_users++)
	287	return ipcomp6_scratches;
	288
	289	scratches = alloc_percpu(void *);
	290	if (!scratches)
	291	return NULL;
	292
	293	ipcomp6_scratches = scratches;
	294
6f912042	295	for_each_possible_cpu(i) {
1da177e4 LT	296	void *scratch = vmalloc(IPCOMP_SCRATCH_SIZE);
	297	if (!scratch)
	298	return NULL;
	299	*per_cpu_ptr(scratches, i) = scratch;
	300	}
	301
	302	return scratches;
	303	}
	304
e4d5b79c	305	static void ipcomp6_free_tfms(struct crypto_comp **tfms)
1da177e4 LT	306	{
	307	struct ipcomp6_tfms *pos;
	308	int cpu;
	309
	310	list_for_each_entry(pos, &ipcomp6_tfms_list, list) {
	311	if (pos->tfms == tfms)
	312	break;
	313	}
	314
	315	BUG_TRAP(pos);
	316
	317	if (--pos->users)
	318	return;
	319
	320	list_del(&pos->list);
	321	kfree(pos);
	322
	323	if (!tfms)
	324	return;
	325
6f912042	326	for_each_possible_cpu(cpu) {
e4d5b79c HX	327	struct crypto_comp tfm = per_cpu_ptr(tfms, cpu);
e4d5b79c HX	328	crypto_free_comp(tfm);
1da177e4 LT	329	}
	330	free_percpu(tfms);
	331	}
	332
e4d5b79c	333	static struct crypto_comp *ipcomp6_alloc_tfms(const char alg_name)
1da177e4 LT	334	{
1da177e4 LT	335	struct ipcomp6_tfms *pos;
e4d5b79c	336	struct crypto_comp **tfms;
1da177e4 LT	337	int cpu;
	338
	339	/* This can be any valid CPU ID so we don't need locking. */
6fc8b9e7	340	cpu = raw_smp_processor_id();
1da177e4 LT	341
1da177e4 LT	342	list_for_each_entry(pos, &ipcomp6_tfms_list, list) {
e4d5b79c	343	struct crypto_comp *tfm;
1da177e4 LT	344
	345	tfms = pos->tfms;
	346	tfm = *per_cpu_ptr(tfms, cpu);
	347
e4d5b79c	348	if (!strcmp(crypto_comp_name(tfm), alg_name)) {
1da177e4 LT	349	pos->users++;
	350	return tfms;
	351	}
	352	}
	353
	354	pos = kmalloc(sizeof(*pos), GFP_KERNEL);
	355	if (!pos)
	356	return NULL;
	357
	358	pos->users = 1;
	359	INIT_LIST_HEAD(&pos->list);
	360	list_add(&pos->list, &ipcomp6_tfms_list);
	361
e4d5b79c	362	pos->tfms = tfms = alloc_percpu(struct crypto_comp *);
1da177e4 LT	363	if (!tfms)
	364	goto error;
	365
6f912042	366	for_each_possible_cpu(cpu) {
e4d5b79c HX	367	struct crypto_comp *tfm = crypto_alloc_comp(alg_name, 0,
e4d5b79c HX	368	CRYPTO_ALG_ASYNC);
1da177e4 LT	369	if (!tfm)
	370	goto error;
	371	*per_cpu_ptr(tfms, cpu) = tfm;
	372	}
	373
	374	return tfms;
	375
	376	error:
	377	ipcomp6_free_tfms(tfms);
	378	return NULL;
	379	}
	380
	381	static void ipcomp6_free_data(struct ipcomp_data *ipcd)
	382	{
	383	if (ipcd->tfms)
	384	ipcomp6_free_tfms(ipcd->tfms);
	385	ipcomp6_free_scratches();
	386	}
	387
	388	static void ipcomp6_destroy(struct xfrm_state *x)
	389	{
	390	struct ipcomp_data *ipcd = x->data;
	391	if (!ipcd)
	392	return;
	393	xfrm_state_delete_tunnel(x);
4a3e2f71	394	mutex_lock(&ipcomp6_resource_mutex);
1da177e4	395	ipcomp6_free_data(ipcd);
4a3e2f71	396	mutex_unlock(&ipcomp6_resource_mutex);
1da177e4 LT	397	kfree(ipcd);
	398
	399	xfrm6_tunnel_free_spi((xfrm_address_t *)&x->props.saddr);
	400	}
	401
72cb6962	402	static int ipcomp6_init_state(struct xfrm_state *x)
1da177e4 LT	403	{
	404	int err;
	405	struct ipcomp_data *ipcd;
	406	struct xfrm_algo_desc *calg_desc;
	407
	408	err = -EINVAL;
	409	if (!x->calg)
	410	goto out;
	411
	412	if (x->encap)
	413	goto out;
	414
	415	err = -ENOMEM;
0c600eda	416	ipcd = kzalloc(sizeof(*ipcd), GFP_KERNEL);
1da177e4 LT	417	if (!ipcd)
	418	goto out;
	419
1da177e4	420	x->props.header_len = 0;
7e49e6de	421	if (x->props.mode == XFRM_MODE_TUNNEL)
1da177e4	422	x->props.header_len += sizeof(struct ipv6hdr);
1ab1457c	423
4a3e2f71	424	mutex_lock(&ipcomp6_resource_mutex);
1da177e4 LT	425	if (!ipcomp6_alloc_scratches())
	426	goto error;
	427
	428	ipcd->tfms = ipcomp6_alloc_tfms(x->calg->alg_name);
	429	if (!ipcd->tfms)
	430	goto error;
4a3e2f71	431	mutex_unlock(&ipcomp6_resource_mutex);
1da177e4	432
7e49e6de	433	if (x->props.mode == XFRM_MODE_TUNNEL) {
1da177e4 LT	434	err = ipcomp6_tunnel_attach(x);
	435	if (err)
	436	goto error_tunnel;
	437	}
	438
	439	calg_desc = xfrm_calg_get_byname(x->calg->alg_name, 0);
	440	BUG_ON(!calg_desc);
	441	ipcd->threshold = calg_desc->uinfo.comp.threshold;
	442	x->data = ipcd;
	443	err = 0;
	444	out:
	445	return err;
	446	error_tunnel:
4a3e2f71	447	mutex_lock(&ipcomp6_resource_mutex);
1da177e4 LT	448	error:
1da177e4 LT	449	ipcomp6_free_data(ipcd);
4a3e2f71	450	mutex_unlock(&ipcomp6_resource_mutex);
1da177e4 LT	451	kfree(ipcd);
	452
	453	goto out;
	454	}
	455
1ab1457c	456	static struct xfrm_type ipcomp6_type =
1da177e4 LT	457	{
	458	.description = "IPCOMP6",
	459	.owner = THIS_MODULE,
	460	.proto = IPPROTO_COMP,
	461	.init_state = ipcomp6_init_state,
	462	.destructor = ipcomp6_destroy,
	463	.input = ipcomp6_input,
	464	.output = ipcomp6_output,
aee5adb4	465	.hdr_offset = xfrm6_find_1stfragopt,
1da177e4 LT	466	};
1da177e4 LT	467
1ab1457c	468	static struct inet6_protocol ipcomp6_protocol =
1da177e4 LT	469	{
	470	.handler = xfrm6_rcv,
	471	.err_handler = ipcomp6_err,
	472	.flags = INET6_PROTO_NOPOLICY,
	473	};
	474
	475	static int __init ipcomp6_init(void)
	476	{
	477	if (xfrm_register_type(&ipcomp6_type, AF_INET6) < 0) {
	478	printk(KERN_INFO "ipcomp6 init: can't add xfrm type\n");
	479	return -EAGAIN;
	480	}
	481	if (inet6_add_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0) {
	482	printk(KERN_INFO "ipcomp6 init: can't add protocol\n");
	483	xfrm_unregister_type(&ipcomp6_type, AF_INET6);
	484	return -EAGAIN;
	485	}
	486	return 0;
	487	}
	488
	489	static void __exit ipcomp6_fini(void)
	490	{
1ab1457c	491	if (inet6_del_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0)
1da177e4 LT	492	printk(KERN_INFO "ipv6 ipcomp close: can't remove protocol\n");
	493	if (xfrm_unregister_type(&ipcomp6_type, AF_INET6) < 0)
	494	printk(KERN_INFO "ipv6 ipcomp close: can't remove xfrm type\n");
	495	}
	496
	497	module_init(ipcomp6_init);
	498	module_exit(ipcomp6_fini);
	499	MODULE_LICENSE("GPL");
	500	MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173");
	501	MODULE_AUTHOR("Mitsuru KANDA <mk@linux-ipv6.org>");
	502
	503