[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/semaphore.h>
#include <linux/crypto.h>
#include <linux/err.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 nexthdr;
	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;
	nexthdr = ipch->nexthdr;

	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 = 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);

	local_bh_disable();
	err = crypto_comp_compress(tfm, start, plen, scratch, &dlen);
	local_bh_enable();
	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;

	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;
	t->props.mode = x->props.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 (IS_ERR(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;

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

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

	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 const 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>
1da177e4 LT	38	#include <linux/crypto.h>
4999f362	39	#include <linux/err.h>
1da177e4 LT	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	{
2614fa59	67	int nexthdr;
364c6bad	68	int err = -ENOMEM;
87bdc48d	69	struct ip_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 */
31a4ab93	82	ipch = (void *)skb->data;
2614fa59 HX	83	nexthdr = ipch->nexthdr;
2614fa59 HX	84
b0e380b1	85	skb->transport_header = skb->network_header + sizeof(*ipch);
31a4ab93	86	__skb_pull(skb, sizeof(*ipch));
1da177e4 LT	87
	88	/* decompression */
	89	plen = skb->len;
	90	dlen = IPCOMP_SCRATCH_SIZE;
	91	start = skb->data;
	92
	93	cpu = get_cpu();
	94	scratch = *per_cpu_ptr(ipcomp6_scratches, cpu);
	95	tfm = *per_cpu_ptr(ipcd->tfms, cpu);
	96
	97	err = crypto_comp_decompress(tfm, start, plen, scratch, &dlen);
87bdc48d	98	if (err)
1da177e4	99	goto out_put_cpu;
1da177e4	100
87bdc48d	101	if (dlen < (plen + sizeof(*ipch))) {
1da177e4 LT	102	err = -EINVAL;
	103	goto out_put_cpu;
	104	}
	105
	106	err = pskb_expand_head(skb, 0, dlen - plen, GFP_ATOMIC);
	107	if (err) {
	108	goto out_put_cpu;
	109	}
	110
da952315 HX	111	skb->truesize += dlen - plen;
da952315 HX	112	__skb_put(skb, dlen - plen);
27d7ff46	113	skb_copy_to_linear_data(skb, scratch, dlen);
2614fa59	114	err = nexthdr;
1da177e4	115
1da177e4 LT	116	out_put_cpu:
	117	put_cpu();
	118	out:
1da177e4 LT	119	return err;
	120	}
	121
	122	static int ipcomp6_output(struct xfrm_state x, struct sk_buff skb)
	123	{
	124	int err;
87bdc48d	125	struct ip_comp_hdr *ipch;
1da177e4 LT	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;
1da177e4 LT	131
1da177e4 LT	132	/* check whether datagram len is larger than threshold */
ceb1eec8	133	if (skb->len < ipcd->threshold) {
1da177e4 LT	134	goto out_ok;
	135	}
	136
364c6bad	137	if (skb_linearize_cow(skb))
1da177e4	138	goto out_ok;
1da177e4 LT	139
1da177e4 LT	140	/* compression */
ceb1eec8	141	plen = skb->len;
1da177e4	142	dlen = IPCOMP_SCRATCH_SIZE;
ceb1eec8	143	start = skb->data;
1da177e4 LT	144
	145	cpu = get_cpu();
	146	scratch = *per_cpu_ptr(ipcomp6_scratches, cpu);
	147	tfm = *per_cpu_ptr(ipcd->tfms, cpu);
	148
21e43188	149	local_bh_disable();
1da177e4	150	err = crypto_comp_compress(tfm, start, plen, scratch, &dlen);
21e43188	151	local_bh_enable();
87bdc48d	152	if (err \|\| (dlen + sizeof(*ipch)) >= plen) {
1da177e4 LT	153	put_cpu();
	154	goto out_ok;
	155	}
	156	memcpy(start + sizeof(struct ip_comp_hdr), scratch, dlen);
	157	put_cpu();
ceb1eec8	158	pskb_trim(skb, dlen + sizeof(struct ip_comp_hdr));
1da177e4 LT	159
1da177e4 LT	160	/* insert ipcomp header and replace datagram */
87bdc48d	161	ipch = ip_comp_hdr(skb);
007f0211	162	ipch->nexthdr = *skb_mac_header(skb);
1da177e4 LT	163	ipch->flags = 0;
1da177e4 LT	164	ipch->cpi = htons((u16 )ntohl(x->id.spi));
007f0211	165	*skb_mac_header(skb) = IPPROTO_COMP;
1da177e4 LT	166
1da177e4 LT	167	out_ok:
ceb1eec8 HX	168	skb_push(skb, -skb_network_offset(skb));
ceb1eec8 HX	169
1da177e4 LT	170	return 0;
	171	}
	172
	173	static void ipcomp6_err(struct sk_buff skb, struct inet6_skb_parm opt,
1ab1457c	174	int type, int code, int offset, __be32 info)
1da177e4	175	{
a94cfd19	176	__be32 spi;
1da177e4	177	struct ipv6hdr iph = (struct ipv6hdr)skb->data;
87bdc48d HX	178	struct ip_comp_hdr *ipcomph =
87bdc48d HX	179	(struct ip_comp_hdr *)(skb->data + offset);
1da177e4 LT	180	struct xfrm_state *x;
	181
	182	if (type != ICMPV6_DEST_UNREACH && type != ICMPV6_PKT_TOOBIG)
	183	return;
	184
4195f814	185	spi = htonl(ntohs(ipcomph->cpi));
1da177e4 LT	186	x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, spi, IPPROTO_COMP, AF_INET6);
	187	if (!x)
	188	return;
	189
46b86a2d	190	printk(KERN_DEBUG "pmtu discovery on SA IPCOMP/%08x/" NIP6_FMT "\n",
1da177e4 LT	191	spi, NIP6(iph->daddr));
	192	xfrm_state_put(x);
	193	}
	194
	195	static struct xfrm_state ipcomp6_tunnel_create(struct xfrm_state x)
	196	{
	197	struct xfrm_state *t = NULL;
	198
	199	t = xfrm_state_alloc();
	200	if (!t)
	201	goto out;
	202
	203	t->id.proto = IPPROTO_IPV6;
	204	t->id.spi = xfrm6_tunnel_alloc_spi((xfrm_address_t *)&x->props.saddr);
6abaaaae HX	205	if (!t->id.spi)
	206	goto error;
	207
1da177e4 LT	208	memcpy(t->id.daddr.a6, x->id.daddr.a6, sizeof(struct in6_addr));
	209	memcpy(&t->sel, &x->sel, sizeof(t->sel));
	210	t->props.family = AF_INET6;
e40b3286	211	t->props.mode = x->props.mode;
1da177e4 LT	212	memcpy(t->props.saddr.a6, x->props.saddr.a6, sizeof(struct in6_addr));
1da177e4 LT	213
72cb6962	214	if (xfrm_init_state(t))
1da177e4 LT	215	goto error;
1da177e4 LT	216
1da177e4 LT	217	atomic_set(&t->tunnel_users, 1);
	218
	219	out:
	220	return t;
	221
	222	error:
6abaaaae	223	t->km.state = XFRM_STATE_DEAD;
1da177e4	224	xfrm_state_put(t);
6abaaaae	225	t = NULL;
1da177e4 LT	226	goto out;
	227	}
	228
	229	static int ipcomp6_tunnel_attach(struct xfrm_state *x)
	230	{
	231	int err = 0;
	232	struct xfrm_state *t = NULL;
a94cfd19	233	__be32 spi;
1da177e4 LT	234
	235	spi = xfrm6_tunnel_spi_lookup((xfrm_address_t *)&x->props.saddr);
	236	if (spi)
	237	t = xfrm_state_lookup((xfrm_address_t *)&x->id.daddr,
	238	spi, IPPROTO_IPV6, AF_INET6);
	239	if (!t) {
	240	t = ipcomp6_tunnel_create(x);
	241	if (!t) {
	242	err = -EINVAL;
	243	goto out;
	244	}
	245	xfrm_state_insert(t);
	246	xfrm_state_hold(t);
	247	}
	248	x->tunnel = t;
	249	atomic_inc(&t->tunnel_users);
	250
	251	out:
	252	return err;
	253	}
	254
	255	static void ipcomp6_free_scratches(void)
	256	{
	257	int i;
	258	void **scratches;
	259
	260	if (--ipcomp6_scratch_users)
	261	return;
	262
	263	scratches = ipcomp6_scratches;
	264	if (!scratches)
	265	return;
	266
6f912042	267	for_each_possible_cpu(i) {
1da177e4	268	void scratch = per_cpu_ptr(scratches, i);
2b191bef JJ	269
2b191bef JJ	270	vfree(scratch);
1da177e4 LT	271	}
	272
	273	free_percpu(scratches);
	274	}
	275
	276	static void **ipcomp6_alloc_scratches(void)
	277	{
	278	int i;
	279	void **scratches;
	280
	281	if (ipcomp6_scratch_users++)
	282	return ipcomp6_scratches;
	283
	284	scratches = alloc_percpu(void *);
	285	if (!scratches)
	286	return NULL;
	287
	288	ipcomp6_scratches = scratches;
	289
6f912042	290	for_each_possible_cpu(i) {
1da177e4 LT	291	void *scratch = vmalloc(IPCOMP_SCRATCH_SIZE);
	292	if (!scratch)
	293	return NULL;
	294	*per_cpu_ptr(scratches, i) = scratch;
	295	}
	296
	297	return scratches;
	298	}
	299
e4d5b79c	300	static void ipcomp6_free_tfms(struct crypto_comp **tfms)
1da177e4 LT	301	{
	302	struct ipcomp6_tfms *pos;
	303	int cpu;
	304
	305	list_for_each_entry(pos, &ipcomp6_tfms_list, list) {
	306	if (pos->tfms == tfms)
	307	break;
	308	}
	309
	310	BUG_TRAP(pos);
	311
	312	if (--pos->users)
	313	return;
	314
	315	list_del(&pos->list);
	316	kfree(pos);
	317
	318	if (!tfms)
	319	return;
	320
6f912042	321	for_each_possible_cpu(cpu) {
e4d5b79c HX	322	struct crypto_comp tfm = per_cpu_ptr(tfms, cpu);
e4d5b79c HX	323	crypto_free_comp(tfm);
1da177e4 LT	324	}
	325	free_percpu(tfms);
	326	}
	327
e4d5b79c	328	static struct crypto_comp *ipcomp6_alloc_tfms(const char alg_name)
1da177e4 LT	329	{
1da177e4 LT	330	struct ipcomp6_tfms *pos;
e4d5b79c	331	struct crypto_comp **tfms;
1da177e4 LT	332	int cpu;
	333
	334	/* This can be any valid CPU ID so we don't need locking. */
6fc8b9e7	335	cpu = raw_smp_processor_id();
1da177e4 LT	336
1da177e4 LT	337	list_for_each_entry(pos, &ipcomp6_tfms_list, list) {
e4d5b79c	338	struct crypto_comp *tfm;
1da177e4 LT	339
	340	tfms = pos->tfms;
	341	tfm = *per_cpu_ptr(tfms, cpu);
	342
e4d5b79c	343	if (!strcmp(crypto_comp_name(tfm), alg_name)) {
1da177e4 LT	344	pos->users++;
	345	return tfms;
	346	}
	347	}
	348
	349	pos = kmalloc(sizeof(*pos), GFP_KERNEL);
	350	if (!pos)
	351	return NULL;
	352
	353	pos->users = 1;
	354	INIT_LIST_HEAD(&pos->list);
	355	list_add(&pos->list, &ipcomp6_tfms_list);
	356
e4d5b79c	357	pos->tfms = tfms = alloc_percpu(struct crypto_comp *);
1da177e4 LT	358	if (!tfms)
	359	goto error;
	360
6f912042	361	for_each_possible_cpu(cpu) {
e4d5b79c HX	362	struct crypto_comp *tfm = crypto_alloc_comp(alg_name, 0,
e4d5b79c HX	363	CRYPTO_ALG_ASYNC);
4999f362	364	if (IS_ERR(tfm))
1da177e4 LT	365	goto error;
	366	*per_cpu_ptr(tfms, cpu) = tfm;
	367	}
	368
	369	return tfms;
	370
	371	error:
	372	ipcomp6_free_tfms(tfms);
	373	return NULL;
	374	}
	375
	376	static void ipcomp6_free_data(struct ipcomp_data *ipcd)
	377	{
	378	if (ipcd->tfms)
	379	ipcomp6_free_tfms(ipcd->tfms);
	380	ipcomp6_free_scratches();
	381	}
	382
	383	static void ipcomp6_destroy(struct xfrm_state *x)
	384	{
	385	struct ipcomp_data *ipcd = x->data;
	386	if (!ipcd)
	387	return;
	388	xfrm_state_delete_tunnel(x);
4a3e2f71	389	mutex_lock(&ipcomp6_resource_mutex);
1da177e4	390	ipcomp6_free_data(ipcd);
4a3e2f71	391	mutex_unlock(&ipcomp6_resource_mutex);
1da177e4 LT	392	kfree(ipcd);
	393
	394	xfrm6_tunnel_free_spi((xfrm_address_t *)&x->props.saddr);
	395	}
	396
72cb6962	397	static int ipcomp6_init_state(struct xfrm_state *x)
1da177e4 LT	398	{
	399	int err;
	400	struct ipcomp_data *ipcd;
	401	struct xfrm_algo_desc *calg_desc;
	402
	403	err = -EINVAL;
	404	if (!x->calg)
	405	goto out;
	406
	407	if (x->encap)
	408	goto out;
	409
1da177e4	410	x->props.header_len = 0;
ca68145f	411	switch (x->props.mode) {
ca68145f HX	412	case XFRM_MODE_TRANSPORT:
	413	break;
	414	case XFRM_MODE_TUNNEL:
1da177e4	415	x->props.header_len += sizeof(struct ipv6hdr);
e40b3286	416	break;
ca68145f	417	default:
e40b3286	418	goto out;
ca68145f	419	}
1ab1457c	420
e40b3286 HX	421	err = -ENOMEM;
	422	ipcd = kzalloc(sizeof(*ipcd), GFP_KERNEL);
	423	if (!ipcd)
	424	goto out;
	425
4a3e2f71	426	mutex_lock(&ipcomp6_resource_mutex);
1da177e4 LT	427	if (!ipcomp6_alloc_scratches())
	428	goto error;
	429
	430	ipcd->tfms = ipcomp6_alloc_tfms(x->calg->alg_name);
	431	if (!ipcd->tfms)
	432	goto error;
4a3e2f71	433	mutex_unlock(&ipcomp6_resource_mutex);
1da177e4	434
7e49e6de	435	if (x->props.mode == XFRM_MODE_TUNNEL) {
1da177e4 LT	436	err = ipcomp6_tunnel_attach(x);
	437	if (err)
	438	goto error_tunnel;
	439	}
	440
	441	calg_desc = xfrm_calg_get_byname(x->calg->alg_name, 0);
	442	BUG_ON(!calg_desc);
	443	ipcd->threshold = calg_desc->uinfo.comp.threshold;
	444	x->data = ipcd;
	445	err = 0;
	446	out:
	447	return err;
	448	error_tunnel:
4a3e2f71	449	mutex_lock(&ipcomp6_resource_mutex);
1da177e4 LT	450	error:
1da177e4 LT	451	ipcomp6_free_data(ipcd);
4a3e2f71	452	mutex_unlock(&ipcomp6_resource_mutex);
1da177e4 LT	453	kfree(ipcd);
	454
	455	goto out;
	456	}
	457
533cb5b0	458	static const struct xfrm_type ipcomp6_type =
1da177e4 LT	459	{
	460	.description = "IPCOMP6",
	461	.owner = THIS_MODULE,
	462	.proto = IPPROTO_COMP,
	463	.init_state = ipcomp6_init_state,
	464	.destructor = ipcomp6_destroy,
	465	.input = ipcomp6_input,
	466	.output = ipcomp6_output,
aee5adb4	467	.hdr_offset = xfrm6_find_1stfragopt,
1da177e4 LT	468	};
1da177e4 LT	469
1ab1457c	470	static struct inet6_protocol ipcomp6_protocol =
1da177e4 LT	471	{
	472	.handler = xfrm6_rcv,
	473	.err_handler = ipcomp6_err,
	474	.flags = INET6_PROTO_NOPOLICY,
	475	};
	476
	477	static int __init ipcomp6_init(void)
	478	{
	479	if (xfrm_register_type(&ipcomp6_type, AF_INET6) < 0) {
	480	printk(KERN_INFO "ipcomp6 init: can't add xfrm type\n");
	481	return -EAGAIN;
	482	}
	483	if (inet6_add_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0) {
	484	printk(KERN_INFO "ipcomp6 init: can't add protocol\n");
	485	xfrm_unregister_type(&ipcomp6_type, AF_INET6);
	486	return -EAGAIN;
	487	}
	488	return 0;
	489	}
	490
	491	static void __exit ipcomp6_fini(void)
	492	{
1ab1457c	493	if (inet6_del_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0)
1da177e4 LT	494	printk(KERN_INFO "ipv6 ipcomp close: can't remove protocol\n");
	495	if (xfrm_unregister_type(&ipcomp6_type, AF_INET6) < 0)
	496	printk(KERN_INFO "ipv6 ipcomp close: can't remove xfrm type\n");
	497	}
	498
	499	module_init(ipcomp6_init);
	500	module_exit(ipcomp6_fini);
	501	MODULE_LICENSE("GPL");
	502	MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173");
	503	MODULE_AUTHOR("Mitsuru KANDA <mk@linux-ipv6.org>");
	504
d3d6dd3a	505	MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_COMP);