[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/config.h>
#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_tfm **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 xfrm_decap_state *decap, struct sk_buff *skb)
{
	int err = 0;
	u8 nexthdr = 0;
	int hdr_len = skb->h.raw - skb->nh.raw;
	unsigned char *tmp_hdr = NULL;
	struct ipv6hdr *iph;
	int plen, dlen;
	struct ipcomp_data *ipcd = x->data;
	u8 *start, *scratch;
	struct crypto_tfm *tfm;
	int cpu;

	if ((skb_is_nonlinear(skb) || skb_cloned(skb)) &&
		skb_linearize(skb, GFP_ATOMIC) != 0) {
		err = -ENOMEM;
		goto out;
	}

	skb->ip_summed = CHECKSUM_NONE;

	/* Remove ipcomp header and decompress original payload */
	iph = skb->nh.ipv6h;
	tmp_hdr = kmalloc(hdr_len, GFP_ATOMIC);
	if (!tmp_hdr)
		goto out;
	memcpy(tmp_hdr, iph, hdr_len);
	nexthdr = *(u8 *)skb->data;
	skb_pull(skb, sizeof(struct ipv6_comp_hdr)); 
	skb->nh.raw += sizeof(struct ipv6_comp_hdr);
	memcpy(skb->nh.raw, tmp_hdr, hdr_len);
	iph = skb->nh.ipv6h;
	iph->payload_len = htons(ntohs(iph->payload_len) - sizeof(struct ipv6_comp_hdr));
	skb->h.raw = skb->data;

	/* 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_put(skb, dlen - plen);
	memcpy(skb->data, scratch, dlen);

	iph = skb->nh.ipv6h;
	iph->payload_len = htons(skb->len);
	
out_put_cpu:
	put_cpu();
out:
	kfree(tmp_hdr);
	if (err)
		goto error_out;
	return nexthdr;
error_out:
	return err;
}

static int ipcomp6_output(struct xfrm_state *x, struct sk_buff *skb)
{
	int err;
	struct ipv6hdr *top_iph;
	int hdr_len;
	struct ipv6_comp_hdr *ipch;
	struct ipcomp_data *ipcd = x->data;
	int plen, dlen;
	u8 *start, *scratch;
	struct crypto_tfm *tfm;
	int cpu;

	hdr_len = skb->h.raw - skb->data;

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

	if ((skb_is_nonlinear(skb) || skb_cloned(skb)) &&
		skb_linearize(skb, GFP_ATOMIC) != 0) {
		goto out_ok;
	}

	/* compression */
	plen = skb->len - hdr_len;
	dlen = IPCOMP_SCRATCH_SIZE;
	start = skb->h.raw;

	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->nh.raw;
	ipch->flags = 0;
	ipch->cpi = htons((u16 )ntohl(x->id.spi));
	*skb->nh.raw = 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, __u32 info)
{
	u32 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 = ntohl(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);
	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 = 1;
	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:
	xfrm_state_put(t);
	goto out;
}

static int ipcomp6_tunnel_attach(struct xfrm_state *x)
{
	int err = 0;
	struct xfrm_state *t = NULL;
	u32 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_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_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_tfm **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_cpu(cpu) {
		struct crypto_tfm *tfm = *per_cpu_ptr(tfms, cpu);
		crypto_free_tfm(tfm);
	}
	free_percpu(tfms);
}

static struct crypto_tfm **ipcomp6_alloc_tfms(const char *alg_name)
{
	struct ipcomp6_tfms *pos;
	struct crypto_tfm **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_tfm *tfm;

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

		if (!strcmp(crypto_tfm_alg_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_tfm *);
	if (!tfms)
		goto error;

	for_each_cpu(cpu) {
		struct crypto_tfm *tfm = crypto_alloc_tfm(alg_name, 0);
		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)
		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) {
		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,
};

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.
	12	*
	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.
	17	*
	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	*/
	22	/*
	23	* [Memo]
	24	*
	25	* Outbound:
	26	* The compression of IP datagram MUST be done before AH/ESP processing,
	27	* fragmentation, and the addition of Hop-by-Hop/Routing header.
	28	*
	29	* Inbound:
	30	* The decompression of IP datagram MUST be done after the reassembly,
	31	* AH/ESP processing.
	32	*/
	33	#include <linux/config.h>
	34	#include <linux/module.h>
	35	#include <net/ip.h>
	36	#include <net/xfrm.h>
	37	#include <net/ipcomp.h>
	38	#include <asm/scatterlist.h>
	39	#include <asm/semaphore.h>
	40	#include <linux/crypto.h>
	41	#include <linux/pfkeyv2.h>
	42	#include <linux/random.h>
	43	#include <linux/percpu.h>
	44	#include <linux/smp.h>
	45	#include <linux/list.h>
	46	#include <linux/vmalloc.h>
	47	#include <linux/rtnetlink.h>
	48	#include <net/icmp.h>
	49	#include <net/ipv6.h>
14c85021	50	#include <net/protocol.h>
1da177e4 LT	51	#include <linux/ipv6.h>
1da177e4 LT	52	#include <linux/icmpv6.h>
4a3e2f71	53	#include <linux/mutex.h>
1da177e4 LT	54
	55	struct ipcomp6_tfms {
	56	struct list_head list;
	57	struct crypto_tfm **tfms;
	58	int users;
	59	};
	60
4a3e2f71	61	static DEFINE_MUTEX(ipcomp6_resource_mutex);
1da177e4 LT	62	static void **ipcomp6_scratches;
	63	static int ipcomp6_scratch_users;
	64	static LIST_HEAD(ipcomp6_tfms_list);
	65
	66	static int ipcomp6_input(struct xfrm_state x, struct xfrm_decap_state decap, struct sk_buff *skb)
	67	{
	68	int err = 0;
	69	u8 nexthdr = 0;
	70	int hdr_len = skb->h.raw - skb->nh.raw;
	71	unsigned char *tmp_hdr = NULL;
	72	struct ipv6hdr *iph;
	73	int plen, dlen;
	74	struct ipcomp_data *ipcd = x->data;
	75	u8 start, scratch;
	76	struct crypto_tfm *tfm;
	77	int cpu;
	78
	79	if ((skb_is_nonlinear(skb) \|\| skb_cloned(skb)) &&
	80	skb_linearize(skb, GFP_ATOMIC) != 0) {
	81	err = -ENOMEM;
	82	goto out;
	83	}
	84
	85	skb->ip_summed = CHECKSUM_NONE;
	86
	87	/* Remove ipcomp header and decompress original payload */
	88	iph = skb->nh.ipv6h;
	89	tmp_hdr = kmalloc(hdr_len, GFP_ATOMIC);
	90	if (!tmp_hdr)
	91	goto out;
	92	memcpy(tmp_hdr, iph, hdr_len);
	93	nexthdr = (u8 )skb->data;
	94	skb_pull(skb, sizeof(struct ipv6_comp_hdr));
	95	skb->nh.raw += sizeof(struct ipv6_comp_hdr);
	96	memcpy(skb->nh.raw, tmp_hdr, hdr_len);
	97	iph = skb->nh.ipv6h;
	98	iph->payload_len = htons(ntohs(iph->payload_len) - sizeof(struct ipv6_comp_hdr));
	99	skb->h.raw = skb->data;
	100
	101	/* decompression */
	102	plen = skb->len;
	103	dlen = IPCOMP_SCRATCH_SIZE;
	104	start = skb->data;
	105
	106	cpu = get_cpu();
	107	scratch = *per_cpu_ptr(ipcomp6_scratches, cpu);
	108	tfm = *per_cpu_ptr(ipcd->tfms, cpu);
	109
	110	err = crypto_comp_decompress(tfm, start, plen, scratch, &dlen);
	111	if (err) {
	112	err = -EINVAL;
	113	goto out_put_cpu;
	114	}
	115
	116	if (dlen < (plen + sizeof(struct ipv6_comp_hdr))) {
	117	err = -EINVAL;
	118	goto out_put_cpu;
	119	}
	120
	121	err = pskb_expand_head(skb, 0, dlen - plen, GFP_ATOMIC);
	122	if (err) {
	123	goto out_put_cpu;
	124	}
	125
126	skb_put(skb, dlen - plen);
127	memcpy(skb->data, scratch, dlen);
128
129	iph = skb->nh.ipv6h;
130	iph->payload_len = htons(skb->len);
131
132	out_put_cpu:
133	put_cpu();
134	out:
a51482bd	135	kfree(tmp_hdr);
1da177e4 LT	136	if (err)
	137	goto error_out;
	138	return nexthdr;
	139	error_out:
	140	return err;
	141	}
	142
	143	static int ipcomp6_output(struct xfrm_state x, struct sk_buff skb)
	144	{
	145	int err;
	146	struct ipv6hdr *top_iph;
	147	int hdr_len;
	148	struct ipv6_comp_hdr *ipch;
	149	struct ipcomp_data *ipcd = x->data;
	150	int plen, dlen;
	151	u8 start, scratch;
	152	struct crypto_tfm *tfm;
	153	int cpu;
	154
	155	hdr_len = skb->h.raw - skb->data;
	156
	157	/* check whether datagram len is larger than threshold */
	158	if ((skb->len - hdr_len) < ipcd->threshold) {
	159	goto out_ok;
	160	}
	161
	162	if ((skb_is_nonlinear(skb) \|\| skb_cloned(skb)) &&
	163	skb_linearize(skb, GFP_ATOMIC) != 0) {
	164	goto out_ok;
	165	}
	166
	167	/* compression */
	168	plen = skb->len - hdr_len;
	169	dlen = IPCOMP_SCRATCH_SIZE;
	170	start = skb->h.raw;
	171
	172	cpu = get_cpu();
	173	scratch = *per_cpu_ptr(ipcomp6_scratches, cpu);
	174	tfm = *per_cpu_ptr(ipcd->tfms, cpu);
	175
	176	err = crypto_comp_compress(tfm, start, plen, scratch, &dlen);
	177	if (err \|\| (dlen + sizeof(struct ipv6_comp_hdr)) >= plen) {
	178	put_cpu();
	179	goto out_ok;
	180	}
	181	memcpy(start + sizeof(struct ip_comp_hdr), scratch, dlen);
	182	put_cpu();
	183	pskb_trim(skb, hdr_len + dlen + sizeof(struct ip_comp_hdr));
	184
	185	/* insert ipcomp header and replace datagram */
	186	top_iph = (struct ipv6hdr *)skb->data;
	187
	188	top_iph->payload_len = htons(skb->len - sizeof(struct ipv6hdr));
	189
	190	ipch = (struct ipv6_comp_hdr *)start;
	191	ipch->nexthdr = *skb->nh.raw;
	192	ipch->flags = 0;
	193	ipch->cpi = htons((u16 )ntohl(x->id.spi));
	194	*skb->nh.raw = IPPROTO_COMP;
	195
	196	out_ok:
	197	return 0;
	198	}
	199
200	static void ipcomp6_err(struct sk_buff skb, struct inet6_skb_parm opt,
201	int type, int code, int offset, __u32 info)
202	{
203	u32 spi;
204	struct ipv6hdr iph = (struct ipv6hdr)skb->data;
205	struct ipv6_comp_hdr ipcomph = (struct ipv6_comp_hdr)(skb->data+offset);
206	struct xfrm_state *x;
207
208	if (type != ICMPV6_DEST_UNREACH && type != ICMPV6_PKT_TOOBIG)
209	return;
210
211	spi = ntohl(ntohs(ipcomph->cpi));
212	x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr, spi, IPPROTO_COMP, AF_INET6);
213	if (!x)
214	return;
215
46b86a2d	216	printk(KERN_DEBUG "pmtu discovery on SA IPCOMP/%08x/" NIP6_FMT "\n",
1da177e4 LT	217	spi, NIP6(iph->daddr));
	218	xfrm_state_put(x);
	219	}
	220
	221	static struct xfrm_state ipcomp6_tunnel_create(struct xfrm_state x)
	222	{
	223	struct xfrm_state *t = NULL;
	224
	225	t = xfrm_state_alloc();
	226	if (!t)
	227	goto out;
	228
	229	t->id.proto = IPPROTO_IPV6;
	230	t->id.spi = xfrm6_tunnel_alloc_spi((xfrm_address_t *)&x->props.saddr);
	231	memcpy(t->id.daddr.a6, x->id.daddr.a6, sizeof(struct in6_addr));
	232	memcpy(&t->sel, &x->sel, sizeof(t->sel));
	233	t->props.family = AF_INET6;
	234	t->props.mode = 1;
	235	memcpy(t->props.saddr.a6, x->props.saddr.a6, sizeof(struct in6_addr));
	236
72cb6962	237	if (xfrm_init_state(t))
1da177e4 LT	238	goto error;
1da177e4 LT	239
1da177e4 LT	240	atomic_set(&t->tunnel_users, 1);
	241
	242	out:
	243	return t;
	244
	245	error:
	246	xfrm_state_put(t);
	247	goto out;
	248	}
	249
	250	static int ipcomp6_tunnel_attach(struct xfrm_state *x)
	251	{
	252	int err = 0;
	253	struct xfrm_state *t = NULL;
	254	u32 spi;
	255
	256	spi = xfrm6_tunnel_spi_lookup((xfrm_address_t *)&x->props.saddr);
	257	if (spi)
	258	t = xfrm_state_lookup((xfrm_address_t *)&x->id.daddr,
	259	spi, IPPROTO_IPV6, AF_INET6);
	260	if (!t) {
	261	t = ipcomp6_tunnel_create(x);
	262	if (!t) {
	263	err = -EINVAL;
	264	goto out;
	265	}
	266	xfrm_state_insert(t);
	267	xfrm_state_hold(t);
	268	}
	269	x->tunnel = t;
	270	atomic_inc(&t->tunnel_users);
	271
	272	out:
	273	return err;
	274	}
	275
	276	static void ipcomp6_free_scratches(void)
	277	{
	278	int i;
	279	void **scratches;
	280
	281	if (--ipcomp6_scratch_users)
	282	return;
	283
	284	scratches = ipcomp6_scratches;
	285	if (!scratches)
	286	return;
	287
	288	for_each_cpu(i) {
	289	void scratch = per_cpu_ptr(scratches, i);
2b191bef JJ	290
2b191bef JJ	291	vfree(scratch);
1da177e4 LT	292	}
	293
	294	free_percpu(scratches);
	295	}
	296
	297	static void **ipcomp6_alloc_scratches(void)
	298	{
	299	int i;
	300	void **scratches;
	301
	302	if (ipcomp6_scratch_users++)
	303	return ipcomp6_scratches;
	304
	305	scratches = alloc_percpu(void *);
	306	if (!scratches)
	307	return NULL;
	308
	309	ipcomp6_scratches = scratches;
	310
	311	for_each_cpu(i) {
	312	void *scratch = vmalloc(IPCOMP_SCRATCH_SIZE);
	313	if (!scratch)
	314	return NULL;
	315	*per_cpu_ptr(scratches, i) = scratch;
	316	}
	317
	318	return scratches;
	319	}
	320
	321	static void ipcomp6_free_tfms(struct crypto_tfm **tfms)
	322	{
	323	struct ipcomp6_tfms *pos;
	324	int cpu;
	325
	326	list_for_each_entry(pos, &ipcomp6_tfms_list, list) {
	327	if (pos->tfms == tfms)
	328	break;
	329	}
	330
	331	BUG_TRAP(pos);
	332
	333	if (--pos->users)
	334	return;
	335
	336	list_del(&pos->list);
	337	kfree(pos);
	338
	339	if (!tfms)
	340	return;
	341
	342	for_each_cpu(cpu) {
	343	struct crypto_tfm tfm = per_cpu_ptr(tfms, cpu);
573dbd95	344	crypto_free_tfm(tfm);
1da177e4 LT	345	}
	346	free_percpu(tfms);
	347	}
	348
	349	static struct crypto_tfm *ipcomp6_alloc_tfms(const char alg_name)
	350	{
	351	struct ipcomp6_tfms *pos;
	352	struct crypto_tfm **tfms;
	353	int cpu;
	354
	355	/* This can be any valid CPU ID so we don't need locking. */
6fc8b9e7	356	cpu = raw_smp_processor_id();
1da177e4 LT	357
	358	list_for_each_entry(pos, &ipcomp6_tfms_list, list) {
	359	struct crypto_tfm *tfm;
	360
	361	tfms = pos->tfms;
	362	tfm = *per_cpu_ptr(tfms, cpu);
	363
	364	if (!strcmp(crypto_tfm_alg_name(tfm), alg_name)) {
	365	pos->users++;
	366	return tfms;
	367	}
	368	}
	369
	370	pos = kmalloc(sizeof(*pos), GFP_KERNEL);
	371	if (!pos)
	372	return NULL;
	373
	374	pos->users = 1;
	375	INIT_LIST_HEAD(&pos->list);
	376	list_add(&pos->list, &ipcomp6_tfms_list);
	377
	378	pos->tfms = tfms = alloc_percpu(struct crypto_tfm *);
	379	if (!tfms)
	380	goto error;
	381
	382	for_each_cpu(cpu) {
	383	struct crypto_tfm *tfm = crypto_alloc_tfm(alg_name, 0);
	384	if (!tfm)
	385	goto error;
	386	*per_cpu_ptr(tfms, cpu) = tfm;
	387	}
	388
	389	return tfms;
	390
	391	error:
	392	ipcomp6_free_tfms(tfms);
	393	return NULL;
	394	}
	395
	396	static void ipcomp6_free_data(struct ipcomp_data *ipcd)
	397	{
	398	if (ipcd->tfms)
	399	ipcomp6_free_tfms(ipcd->tfms);
	400	ipcomp6_free_scratches();
	401	}
	402
	403	static void ipcomp6_destroy(struct xfrm_state *x)
	404	{
	405	struct ipcomp_data *ipcd = x->data;
	406	if (!ipcd)
	407	return;
	408	xfrm_state_delete_tunnel(x);
4a3e2f71	409	mutex_lock(&ipcomp6_resource_mutex);
1da177e4	410	ipcomp6_free_data(ipcd);
4a3e2f71	411	mutex_unlock(&ipcomp6_resource_mutex);
1da177e4 LT	412	kfree(ipcd);
	413
	414	xfrm6_tunnel_free_spi((xfrm_address_t *)&x->props.saddr);
	415	}
	416
72cb6962	417	static int ipcomp6_init_state(struct xfrm_state *x)
1da177e4 LT	418	{
	419	int err;
	420	struct ipcomp_data *ipcd;
	421	struct xfrm_algo_desc *calg_desc;
	422
	423	err = -EINVAL;
	424	if (!x->calg)
	425	goto out;
	426
	427	if (x->encap)
	428	goto out;
	429
	430	err = -ENOMEM;
0c600eda	431	ipcd = kzalloc(sizeof(*ipcd), GFP_KERNEL);
1da177e4 LT	432	if (!ipcd)
	433	goto out;
	434
1da177e4 LT	435	x->props.header_len = 0;
	436	if (x->props.mode)
	437	x->props.header_len += sizeof(struct ipv6hdr);
	438
4a3e2f71	439	mutex_lock(&ipcomp6_resource_mutex);
1da177e4 LT	440	if (!ipcomp6_alloc_scratches())
	441	goto error;
	442
	443	ipcd->tfms = ipcomp6_alloc_tfms(x->calg->alg_name);
	444	if (!ipcd->tfms)
	445	goto error;
4a3e2f71	446	mutex_unlock(&ipcomp6_resource_mutex);
1da177e4 LT	447
	448	if (x->props.mode) {
	449	err = ipcomp6_tunnel_attach(x);
	450	if (err)
	451	goto error_tunnel;
	452	}
	453
	454	calg_desc = xfrm_calg_get_byname(x->calg->alg_name, 0);
	455	BUG_ON(!calg_desc);
	456	ipcd->threshold = calg_desc->uinfo.comp.threshold;
	457	x->data = ipcd;
	458	err = 0;
	459	out:
	460	return err;
	461	error_tunnel:
4a3e2f71	462	mutex_lock(&ipcomp6_resource_mutex);
1da177e4 LT	463	error:
1da177e4 LT	464	ipcomp6_free_data(ipcd);
4a3e2f71	465	mutex_unlock(&ipcomp6_resource_mutex);
1da177e4 LT	466	kfree(ipcd);
	467
	468	goto out;
	469	}
	470
	471	static struct xfrm_type ipcomp6_type =
	472	{
	473	.description = "IPCOMP6",
	474	.owner = THIS_MODULE,
	475	.proto = IPPROTO_COMP,
	476	.init_state = ipcomp6_init_state,
	477	.destructor = ipcomp6_destroy,
	478	.input = ipcomp6_input,
	479	.output = ipcomp6_output,
	480	};
	481
	482	static struct inet6_protocol ipcomp6_protocol =
	483	{
	484	.handler = xfrm6_rcv,
	485	.err_handler = ipcomp6_err,
	486	.flags = INET6_PROTO_NOPOLICY,
	487	};
	488
	489	static int __init ipcomp6_init(void)
	490	{
	491	if (xfrm_register_type(&ipcomp6_type, AF_INET6) < 0) {
	492	printk(KERN_INFO "ipcomp6 init: can't add xfrm type\n");
	493	return -EAGAIN;
	494	}
	495	if (inet6_add_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0) {
	496	printk(KERN_INFO "ipcomp6 init: can't add protocol\n");
	497	xfrm_unregister_type(&ipcomp6_type, AF_INET6);
	498	return -EAGAIN;
	499	}
	500	return 0;
	501	}
	502
	503	static void __exit ipcomp6_fini(void)
	504	{
	505	if (inet6_del_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0)
	506	printk(KERN_INFO "ipv6 ipcomp close: can't remove protocol\n");
	507	if (xfrm_unregister_type(&ipcomp6_type, AF_INET6) < 0)
	508	printk(KERN_INFO "ipv6 ipcomp close: can't remove xfrm type\n");
	509	}
	510
	511	module_init(ipcomp6_init);
	512	module_exit(ipcomp6_fini);
	513	MODULE_LICENSE("GPL");
	514	MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173");
	515	MODULE_AUTHOR("Mitsuru KANDA <mk@linux-ipv6.org>");
	516
	517