[GitHub/mt8127/android_kernel_alcatel_ttab.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 <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	37	#include <linux/crypto.h>
4999f362	38	#include <linux/err.h>
1da177e4 LT	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	{
2614fa59	66	int nexthdr;
364c6bad	67	int err = -ENOMEM;
87bdc48d	68	struct ip_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;
2614fa59 HX	82	nexthdr = ipch->nexthdr;
2614fa59 HX	83
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);
87bdc48d	97	if (err)
1da177e4	98	goto out_put_cpu;
1da177e4	99
87bdc48d	100	if (dlen < (plen + sizeof(*ipch))) {
1da177e4 LT	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);
2614fa59	113	err = 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;
87bdc48d	124	struct ip_comp_hdr *ipch;
1da177e4 LT	125	struct ipcomp_data *ipcd = x->data;
	126	int plen, dlen;
	127	u8 start, scratch;
e4d5b79c	128	struct crypto_comp *tfm;
1da177e4	129	int cpu;
1da177e4 LT	130
1da177e4 LT	131	/* check whether datagram len is larger than threshold */
ceb1eec8	132	if (skb->len < ipcd->threshold) {
1da177e4 LT	133	goto out_ok;
	134	}
	135
364c6bad	136	if (skb_linearize_cow(skb))
1da177e4	137	goto out_ok;
1da177e4 LT	138
1da177e4 LT	139	/* compression */
ceb1eec8	140	plen = skb->len;
1da177e4	141	dlen = IPCOMP_SCRATCH_SIZE;
ceb1eec8	142	start = skb->data;
1da177e4 LT	143
	144	cpu = get_cpu();
	145	scratch = *per_cpu_ptr(ipcomp6_scratches, cpu);
	146	tfm = *per_cpu_ptr(ipcd->tfms, cpu);
	147
21e43188	148	local_bh_disable();
1da177e4	149	err = crypto_comp_compress(tfm, start, plen, scratch, &dlen);
21e43188	150	local_bh_enable();
87bdc48d	151	if (err \|\| (dlen + sizeof(*ipch)) >= plen) {
1da177e4 LT	152	put_cpu();
	153	goto out_ok;
	154	}
	155	memcpy(start + sizeof(struct ip_comp_hdr), scratch, dlen);
	156	put_cpu();
ceb1eec8	157	pskb_trim(skb, dlen + sizeof(struct ip_comp_hdr));
1da177e4 LT	158
1da177e4 LT	159	/* insert ipcomp header and replace datagram */
87bdc48d	160	ipch = ip_comp_hdr(skb);
007f0211	161	ipch->nexthdr = *skb_mac_header(skb);
1da177e4 LT	162	ipch->flags = 0;
1da177e4 LT	163	ipch->cpi = htons((u16 )ntohl(x->id.spi));
007f0211	164	*skb_mac_header(skb) = IPPROTO_COMP;
1da177e4 LT	165
1da177e4 LT	166	out_ok:
ceb1eec8 HX	167	skb_push(skb, -skb_network_offset(skb));
ceb1eec8 HX	168
1da177e4 LT	169	return 0;
	170	}
	171
	172	static void ipcomp6_err(struct sk_buff skb, struct inet6_skb_parm opt,
1ab1457c	173	int type, int code, int offset, __be32 info)
1da177e4	174	{
a94cfd19	175	__be32 spi;
1da177e4	176	struct ipv6hdr iph = (struct ipv6hdr)skb->data;
87bdc48d HX	177	struct ip_comp_hdr *ipcomph =
87bdc48d HX	178	(struct ip_comp_hdr *)(skb->data + offset);
1da177e4 LT	179	struct xfrm_state *x;
	180
	181	if (type != ICMPV6_DEST_UNREACH && type != ICMPV6_PKT_TOOBIG)
	182	return;
	183
4195f814	184	spi = htonl(ntohs(ipcomph->cpi));
1da177e4 LT	185	x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, spi, IPPROTO_COMP, AF_INET6);
	186	if (!x)
	187	return;
	188
46b86a2d	189	printk(KERN_DEBUG "pmtu discovery on SA IPCOMP/%08x/" NIP6_FMT "\n",
1da177e4 LT	190	spi, NIP6(iph->daddr));
	191	xfrm_state_put(x);
	192	}
	193
	194	static struct xfrm_state ipcomp6_tunnel_create(struct xfrm_state x)
	195	{
	196	struct xfrm_state *t = NULL;
	197
	198	t = xfrm_state_alloc();
	199	if (!t)
	200	goto out;
	201
	202	t->id.proto = IPPROTO_IPV6;
	203	t->id.spi = xfrm6_tunnel_alloc_spi((xfrm_address_t *)&x->props.saddr);
6abaaaae HX	204	if (!t->id.spi)
	205	goto error;
	206
1da177e4 LT	207	memcpy(t->id.daddr.a6, x->id.daddr.a6, sizeof(struct in6_addr));
	208	memcpy(&t->sel, &x->sel, sizeof(t->sel));
	209	t->props.family = AF_INET6;
e40b3286	210	t->props.mode = x->props.mode;
1da177e4 LT	211	memcpy(t->props.saddr.a6, x->props.saddr.a6, sizeof(struct in6_addr));
1da177e4 LT	212
72cb6962	213	if (xfrm_init_state(t))
1da177e4 LT	214	goto error;
1da177e4 LT	215
1da177e4 LT	216	atomic_set(&t->tunnel_users, 1);
	217
	218	out:
	219	return t;
	220
	221	error:
6abaaaae	222	t->km.state = XFRM_STATE_DEAD;
1da177e4	223	xfrm_state_put(t);
6abaaaae	224	t = NULL;
1da177e4 LT	225	goto out;
	226	}
	227
	228	static int ipcomp6_tunnel_attach(struct xfrm_state *x)
	229	{
	230	int err = 0;
	231	struct xfrm_state *t = NULL;
a94cfd19	232	__be32 spi;
1da177e4 LT	233
	234	spi = xfrm6_tunnel_spi_lookup((xfrm_address_t *)&x->props.saddr);
	235	if (spi)
	236	t = xfrm_state_lookup((xfrm_address_t *)&x->id.daddr,
	237	spi, IPPROTO_IPV6, AF_INET6);
	238	if (!t) {
	239	t = ipcomp6_tunnel_create(x);
	240	if (!t) {
	241	err = -EINVAL;
	242	goto out;
	243	}
	244	xfrm_state_insert(t);
	245	xfrm_state_hold(t);
	246	}
	247	x->tunnel = t;
	248	atomic_inc(&t->tunnel_users);
	249
	250	out:
	251	return err;
	252	}
	253
	254	static void ipcomp6_free_scratches(void)
	255	{
	256	int i;
	257	void **scratches;
	258
	259	if (--ipcomp6_scratch_users)
	260	return;
	261
	262	scratches = ipcomp6_scratches;
	263	if (!scratches)
	264	return;
	265
6f912042	266	for_each_possible_cpu(i) {
1da177e4	267	void scratch = per_cpu_ptr(scratches, i);
2b191bef JJ	268
2b191bef JJ	269	vfree(scratch);
1da177e4 LT	270	}
	271
	272	free_percpu(scratches);
	273	}
	274
	275	static void **ipcomp6_alloc_scratches(void)
	276	{
	277	int i;
	278	void **scratches;
	279
	280	if (ipcomp6_scratch_users++)
	281	return ipcomp6_scratches;
	282
	283	scratches = alloc_percpu(void *);
	284	if (!scratches)
	285	return NULL;
	286
	287	ipcomp6_scratches = scratches;
	288
6f912042	289	for_each_possible_cpu(i) {
1da177e4 LT	290	void *scratch = vmalloc(IPCOMP_SCRATCH_SIZE);
	291	if (!scratch)
	292	return NULL;
	293	*per_cpu_ptr(scratches, i) = scratch;
	294	}
	295
	296	return scratches;
	297	}
	298
e4d5b79c	299	static void ipcomp6_free_tfms(struct crypto_comp **tfms)
1da177e4 LT	300	{
	301	struct ipcomp6_tfms *pos;
	302	int cpu;
	303
	304	list_for_each_entry(pos, &ipcomp6_tfms_list, list) {
	305	if (pos->tfms == tfms)
	306	break;
	307	}
	308
	309	BUG_TRAP(pos);
	310
	311	if (--pos->users)
	312	return;
	313
	314	list_del(&pos->list);
	315	kfree(pos);
	316
	317	if (!tfms)
	318	return;
	319
6f912042	320	for_each_possible_cpu(cpu) {
e4d5b79c HX	321	struct crypto_comp tfm = per_cpu_ptr(tfms, cpu);
e4d5b79c HX	322	crypto_free_comp(tfm);
1da177e4 LT	323	}
	324	free_percpu(tfms);
	325	}
	326
e4d5b79c	327	static struct crypto_comp *ipcomp6_alloc_tfms(const char alg_name)
1da177e4 LT	328	{
1da177e4 LT	329	struct ipcomp6_tfms *pos;
e4d5b79c	330	struct crypto_comp **tfms;
1da177e4 LT	331	int cpu;
	332
	333	/* This can be any valid CPU ID so we don't need locking. */
6fc8b9e7	334	cpu = raw_smp_processor_id();
1da177e4 LT	335
1da177e4 LT	336	list_for_each_entry(pos, &ipcomp6_tfms_list, list) {
e4d5b79c	337	struct crypto_comp *tfm;
1da177e4 LT	338
	339	tfms = pos->tfms;
	340	tfm = *per_cpu_ptr(tfms, cpu);
	341
e4d5b79c	342	if (!strcmp(crypto_comp_name(tfm), alg_name)) {
1da177e4 LT	343	pos->users++;
	344	return tfms;
	345	}
	346	}
	347
	348	pos = kmalloc(sizeof(*pos), GFP_KERNEL);
	349	if (!pos)
	350	return NULL;
	351
	352	pos->users = 1;
	353	INIT_LIST_HEAD(&pos->list);
	354	list_add(&pos->list, &ipcomp6_tfms_list);
	355
e4d5b79c	356	pos->tfms = tfms = alloc_percpu(struct crypto_comp *);
1da177e4 LT	357	if (!tfms)
	358	goto error;
	359
6f912042	360	for_each_possible_cpu(cpu) {
e4d5b79c HX	361	struct crypto_comp *tfm = crypto_alloc_comp(alg_name, 0,
e4d5b79c HX	362	CRYPTO_ALG_ASYNC);
4999f362	363	if (IS_ERR(tfm))
1da177e4 LT	364	goto error;
	365	*per_cpu_ptr(tfms, cpu) = tfm;
	366	}
	367
	368	return tfms;
	369
	370	error:
	371	ipcomp6_free_tfms(tfms);
	372	return NULL;
	373	}
	374
	375	static void ipcomp6_free_data(struct ipcomp_data *ipcd)
	376	{
	377	if (ipcd->tfms)
	378	ipcomp6_free_tfms(ipcd->tfms);
	379	ipcomp6_free_scratches();
	380	}
	381
	382	static void ipcomp6_destroy(struct xfrm_state *x)
	383	{
	384	struct ipcomp_data *ipcd = x->data;
	385	if (!ipcd)
	386	return;
	387	xfrm_state_delete_tunnel(x);
4a3e2f71	388	mutex_lock(&ipcomp6_resource_mutex);
1da177e4	389	ipcomp6_free_data(ipcd);
4a3e2f71	390	mutex_unlock(&ipcomp6_resource_mutex);
1da177e4 LT	391	kfree(ipcd);
	392
	393	xfrm6_tunnel_free_spi((xfrm_address_t *)&x->props.saddr);
	394	}
	395
72cb6962	396	static int ipcomp6_init_state(struct xfrm_state *x)
1da177e4 LT	397	{
	398	int err;
	399	struct ipcomp_data *ipcd;
	400	struct xfrm_algo_desc *calg_desc;
	401
	402	err = -EINVAL;
	403	if (!x->calg)
	404	goto out;
	405
	406	if (x->encap)
	407	goto out;
	408
1da177e4	409	x->props.header_len = 0;
ca68145f	410	switch (x->props.mode) {
ca68145f HX	411	case XFRM_MODE_TRANSPORT:
	412	break;
	413	case XFRM_MODE_TUNNEL:
1da177e4	414	x->props.header_len += sizeof(struct ipv6hdr);
e40b3286	415	break;
ca68145f	416	default:
e40b3286	417	goto out;
ca68145f	418	}
1ab1457c	419
e40b3286 HX	420	err = -ENOMEM;
	421	ipcd = kzalloc(sizeof(*ipcd), GFP_KERNEL);
	422	if (!ipcd)
	423	goto out;
	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
533cb5b0	457	static const 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);