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ipsec: ipcomp - Merge IPComp implementations

Browse source 
This patch merges the IPv4/IPv6 IPComp implementations since most
of the code is identical.  As a result future enhancements will no
longer need to be duplicated.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Herbert Xu 2008-07-25 02:54:40 -07:00 committed by David S. Miller
parent cffe1c5d7a
commit 6fccab671f
8 changed files with 377 additions and 606 deletions
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6
include/net/ipcomp.h
View file

@ -14,6 +14,12 @@ struct ipcomp_data {
struct ip_comp_hdr;
struct sk_buff;
struct xfrm_state;
int ipcomp_input(struct xfrm_state *x, struct sk_buff *skb);
int ipcomp_output(struct xfrm_state *x, struct sk_buff *skb);
void ipcomp_destroy(struct xfrm_state *x);
int ipcomp_init_state(struct xfrm_state *x);
static inline struct ip_comp_hdr *ip_comp_hdr(const struct sk_buff *skb)
{

4
net/ipv4/Kconfig
View file

@ -356,10 +356,8 @@ config INET_ESP
config INET_IPCOMP
tristate "IP: IPComp transformation"
select XFRM
select INET_XFRM_TUNNEL
select CRYPTO
select CRYPTO_DEFLATE
select XFRM_IPCOMP
---help---
Support for IP Payload Compression Protocol (IPComp) (RFC3173),
typically needed for IPsec.

315
net/ipv4/ipcomp.c
View file

@ -14,153 +14,14 @@
* - Adaptive compression.
*/
#include <linux/module.h>
#include <linux/crypto.h>
#include <linux/err.h>
#include <linux/pfkeyv2.h>
#include <linux/percpu.h>
#include <linux/smp.h>
#include <linux/list.h>
#include <linux/vmalloc.h>
#include <linux/rtnetlink.h>
#include <linux/mutex.h>
#include <net/ip.h>
#include <net/xfrm.h>
#include <net/icmp.h>
#include <net/ipcomp.h>
#include <net/protocol.h>
struct ipcomp_tfms {
struct list_head list;
struct crypto_comp **tfms;
int users;
};
static DEFINE_MUTEX(ipcomp_resource_mutex);
static void **ipcomp_scratches;
static int ipcomp_scratch_users;
static LIST_HEAD(ipcomp_tfms_list);
static int ipcomp_decompress(struct xfrm_state *x, struct sk_buff *skb)
{
struct ipcomp_data *ipcd = x->data;
const int plen = skb->len;
int dlen = IPCOMP_SCRATCH_SIZE;
const u8 *start = skb->data;
const int cpu = get_cpu();
u8 *scratch = *per_cpu_ptr(ipcomp_scratches, cpu);
struct crypto_comp *tfm = *per_cpu_ptr(ipcd->tfms, cpu);
int err = crypto_comp_decompress(tfm, start, plen, scratch, &dlen);
if (err)
goto out;
if (dlen < (plen + sizeof(struct ip_comp_hdr))) {
err = -EINVAL;
goto out;
}
err = pskb_expand_head(skb, 0, dlen - plen, GFP_ATOMIC);
if (err)
goto out;
skb->truesize += dlen - plen;
__skb_put(skb, dlen - plen);
skb_copy_to_linear_data(skb, scratch, dlen);
out:
put_cpu();
return err;
}
static int ipcomp_input(struct xfrm_state *x, struct sk_buff *skb)
{
int nexthdr;
int err = -ENOMEM;
struct ip_comp_hdr *ipch;
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));
err = ipcomp_decompress(x, skb);
if (err)
goto out;
err = nexthdr;
out:
return err;
}
static int ipcomp_compress(struct xfrm_state *x, struct sk_buff *skb)
{
struct ipcomp_data *ipcd = x->data;
const int plen = skb->len;
int dlen = IPCOMP_SCRATCH_SIZE;
u8 *start = skb->data;
const int cpu = get_cpu();
u8 *scratch = *per_cpu_ptr(ipcomp_scratches, cpu);
struct crypto_comp *tfm = *per_cpu_ptr(ipcd->tfms, cpu);
int err;
local_bh_disable();
err = crypto_comp_compress(tfm, start, plen, scratch, &dlen);
local_bh_enable();
if (err)
goto out;
if ((dlen + sizeof(struct ip_comp_hdr)) >= plen) {
err = -EMSGSIZE;
goto out;
}
memcpy(start + sizeof(struct ip_comp_hdr), scratch, dlen);
put_cpu();
pskb_trim(skb, dlen + sizeof(struct ip_comp_hdr));
return 0;
out:
put_cpu();
return err;
}
static int ipcomp_output(struct xfrm_state *x, struct sk_buff *skb)
{
int err;
struct ip_comp_hdr *ipch;
struct ipcomp_data *ipcd = x->data;
if (skb->len < ipcd->threshold) {
/* Don't bother compressing */
goto out_ok;
}
if (skb_linearize_cow(skb))
goto out_ok;
err = ipcomp_compress(x, skb);
if (err) {
goto out_ok;
}
/* Install ipcomp header, convert into ipcomp 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;
}
#include <net/sock.h>
static void ipcomp4_err(struct sk_buff *skb, u32 info)
{
@ -241,156 +102,12 @@ out:
return err;
}
static void ipcomp_free_scratches(void)
{
int i;
void **scratches;
if (--ipcomp_scratch_users)
return;
scratches = ipcomp_scratches;
if (!scratches)
return;
for_each_possible_cpu(i)
vfree(*per_cpu_ptr(scratches, i));
free_percpu(scratches);
}
static void **ipcomp_alloc_scratches(void)
{
int i;
void **scratches;
if (ipcomp_scratch_users++)
return ipcomp_scratches;
scratches = alloc_percpu(void *);
if (!scratches)
return NULL;
ipcomp_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 ipcomp_free_tfms(struct crypto_comp **tfms)
{
struct ipcomp_tfms *pos;
int cpu;
list_for_each_entry(pos, &ipcomp_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 **ipcomp_alloc_tfms(const char *alg_name)
{
struct ipcomp_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, &ipcomp_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, &ipcomp_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:
ipcomp_free_tfms(tfms);
return NULL;
}
static void ipcomp_free_data(struct ipcomp_data *ipcd)
{
if (ipcd->tfms)
ipcomp_free_tfms(ipcd->tfms);
ipcomp_free_scratches();
}
static void ipcomp_destroy(struct xfrm_state *x)
{
struct ipcomp_data *ipcd = x->data;
if (!ipcd)
return;
xfrm_state_delete_tunnel(x);
mutex_lock(&ipcomp_resource_mutex);
ipcomp_free_data(ipcd);
mutex_unlock(&ipcomp_resource_mutex);
kfree(ipcd);
}
static int ipcomp_init_state(struct xfrm_state *x)
static int ipcomp4_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:
@ -402,40 +119,22 @@ static int ipcomp_init_state(struct xfrm_state *x)
goto out;
}
err = -ENOMEM;
ipcd = kzalloc(sizeof(*ipcd), GFP_KERNEL);
if (!ipcd)
err = ipcomp_init_state(x);
if (err)
goto out;
mutex_lock(&ipcomp_resource_mutex);
if (!ipcomp_alloc_scratches())
goto error;
ipcd->tfms = ipcomp_alloc_tfms(x->calg->alg_name);
if (!ipcd->tfms)
goto error;
mutex_unlock(&ipcomp_resource_mutex);
if (x->props.mode == XFRM_MODE_TUNNEL) {
err = ipcomp_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(&ipcomp_resource_mutex);
error:
ipcomp_free_data(ipcd);
mutex_unlock(&ipcomp_resource_mutex);
kfree(ipcd);
ipcomp_destroy(x);
goto out;
}
@ -443,7 +142,7 @@ static const struct xfrm_type ipcomp_type = {
.description = "IPCOMP4",
.owner = THIS_MODULE,
.proto = IPPROTO_COMP,
.init_state = ipcomp_init_state,
.init_state = ipcomp4_init_state,
.destructor = ipcomp_destroy,
.input = ipcomp_input,
.output = ipcomp_output
@ -481,7 +180,7 @@ module_init(ipcomp4_init);
module_exit(ipcomp4_fini);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp) - RFC3173");
MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp/IPv4) - RFC3173");
MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");
MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_COMP);

4
net/ipv6/Kconfig
View file

@ -96,10 +96,8 @@ config INET6_ESP
config INET6_IPCOMP
tristate "IPv6: IPComp transformation"
select XFRM
select INET6_XFRM_TUNNEL
select CRYPTO
select CRYPTO_DEFLATE
select XFRM_IPCOMP
---help---
Support for IP Payload Compression Protocol (IPComp) (RFC3173),
typically needed for IPsec.

298
net/ipv6/ipcomp6.c
View file

@ -50,125 +50,6 @@
#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)
{
@ -251,161 +132,12 @@ 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:
@ -417,39 +149,21 @@ static int ipcomp6_init_state(struct xfrm_state *x)
goto out;
}
err = -ENOMEM;
ipcd = kzalloc(sizeof(*ipcd), GFP_KERNEL);
if (!ipcd)
err = ipcomp_init_state(x);
if (err)
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);
ipcomp_destroy(x);
goto out;
}
@ -460,9 +174,9 @@ static const struct xfrm_type ipcomp6_type =
.owner = THIS_MODULE,
.proto = IPPROTO_COMP,
.init_state = ipcomp6_init_state,
.destructor = ipcomp6_destroy,
.input = ipcomp6_input,
.output = ipcomp6_output,
.destructor = ipcomp_destroy,
.input = ipcomp_input,
.output = ipcomp_output,
.hdr_offset = xfrm6_find_1stfragopt,
};

6
net/xfrm/Kconfig
View file

@ -46,6 +46,12 @@ config XFRM_STATISTICS
If unsure, say N.
config XFRM_IPCOMP
tristate
select XFRM
select CRYPTO
select CRYPTO_DEFLATE
config NET_KEY
tristate "PF_KEY sockets"
select XFRM

1
net/xfrm/Makefile
View file

@ -6,4 +6,5 @@ obj-$(CONFIG_XFRM) := xfrm_policy.o xfrm_state.o xfrm_hash.o \
xfrm_input.o xfrm_output.o xfrm_algo.o
obj-$(CONFIG_XFRM_STATISTICS) += xfrm_proc.o
obj-$(CONFIG_XFRM_USER) += xfrm_user.o
obj-$(CONFIG_XFRM_IPCOMP) += xfrm_ipcomp.o

349
net/xfrm/xfrm_ipcomp.c Normal file
View file

@ -0,0 +1,349 @@
/*
* IP Payload Compression Protocol (IPComp) - RFC3173.
*
* Copyright (c) 2003 James Morris <jmorris@intercode.com.au>
* Copyright (c) 2003-2008 Herbert Xu <herbert@gondor.apana.org.au>
*
* 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.
*
* Todo:
* - Tunable compression parameters.
* - Compression stats.
* - Adaptive compression.
*/
#include <linux/crypto.h>
#include <linux/err.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/percpu.h>
#include <linux/rtnetlink.h>
#include <linux/smp.h>
#include <linux/vmalloc.h>
#include <net/ip.h>
#include <net/ipcomp.h>
#include <net/xfrm.h>
struct ipcomp_tfms {
struct list_head list;
struct crypto_comp **tfms;
int users;
};
static DEFINE_MUTEX(ipcomp_resource_mutex);
static void **ipcomp_scratches;
static int ipcomp_scratch_users;
static LIST_HEAD(ipcomp_tfms_list);
static int ipcomp_decompress(struct xfrm_state *x, struct sk_buff *skb)
{
struct ipcomp_data *ipcd = x->data;
const int plen = skb->len;
int dlen = IPCOMP_SCRATCH_SIZE;
const u8 *start = skb->data;
const int cpu = get_cpu();
u8 *scratch = *per_cpu_ptr(ipcomp_scratches, cpu);
struct crypto_comp *tfm = *per_cpu_ptr(ipcd->tfms, cpu);
int err = crypto_comp_decompress(tfm, start, plen, scratch, &dlen);
if (err)
goto out;
if (dlen < (plen + sizeof(struct ip_comp_hdr))) {
err = -EINVAL;
goto out;
}
err = pskb_expand_head(skb, 0, dlen - plen, GFP_ATOMIC);
if (err)
goto out;
skb->truesize += dlen - plen;
__skb_put(skb, dlen - plen);
skb_copy_to_linear_data(skb, scratch, dlen);
out:
put_cpu();
return err;
}
int ipcomp_input(struct xfrm_state *x, struct sk_buff *skb)
{
int nexthdr;
int err = -ENOMEM;
struct ip_comp_hdr *ipch;
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));
err = ipcomp_decompress(x, skb);
if (err)
goto out;
err = nexthdr;
out:
return err;
}
EXPORT_SYMBOL_GPL(ipcomp_input);
static int ipcomp_compress(struct xfrm_state *x, struct sk_buff *skb)
{
struct ipcomp_data *ipcd = x->data;
const int plen = skb->len;
int dlen = IPCOMP_SCRATCH_SIZE;
u8 *start = skb->data;
const int cpu = get_cpu();
u8 *scratch = *per_cpu_ptr(ipcomp_scratches, cpu);
struct crypto_comp *tfm = *per_cpu_ptr(ipcd->tfms, cpu);
int err;
local_bh_disable();
err = crypto_comp_compress(tfm, start, plen, scratch, &dlen);
local_bh_enable();
if (err)
goto out;
if ((dlen + sizeof(struct ip_comp_hdr)) >= plen) {
err = -EMSGSIZE;
goto out;
}
memcpy(start + sizeof(struct ip_comp_hdr), scratch, dlen);
put_cpu();
pskb_trim(skb, dlen + sizeof(struct ip_comp_hdr));
return 0;
out:
put_cpu();
return err;
}
int ipcomp_output(struct xfrm_state *x, struct sk_buff *skb)
{
int err;
struct ip_comp_hdr *ipch;
struct ipcomp_data *ipcd = x->data;
if (skb->len < ipcd->threshold) {
/* Don't bother compressing */
goto out_ok;
}
if (skb_linearize_cow(skb))
goto out_ok;
err = ipcomp_compress(x, skb);
if (err) {
goto out_ok;
}
/* Install ipcomp header, convert into ipcomp 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;
}
EXPORT_SYMBOL_GPL(ipcomp_output);
static void ipcomp_free_scratches(void)
{
int i;
void **scratches;
if (--ipcomp_scratch_users)
return;
scratches = ipcomp_scratches;
if (!scratches)
return;
for_each_possible_cpu(i)
vfree(*per_cpu_ptr(scratches, i));
free_percpu(scratches);
}
static void **ipcomp_alloc_scratches(void)
{
int i;
void **scratches;
if (ipcomp_scratch_users++)
return ipcomp_scratches;
scratches = alloc_percpu(void *);
if (!scratches)
return NULL;
ipcomp_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 ipcomp_free_tfms(struct crypto_comp **tfms)
{
struct ipcomp_tfms *pos;
int cpu;
list_for_each_entry(pos, &ipcomp_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 **ipcomp_alloc_tfms(const char *alg_name)
{
struct ipcomp_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, &ipcomp_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, &ipcomp_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:
ipcomp_free_tfms(tfms);
return NULL;
}
static void ipcomp_free_data(struct ipcomp_data *ipcd)
{
if (ipcd->tfms)
ipcomp_free_tfms(ipcd->tfms);
ipcomp_free_scratches();
}
void ipcomp_destroy(struct xfrm_state *x)
{
struct ipcomp_data *ipcd = x->data;
if (!ipcd)
return;
xfrm_state_delete_tunnel(x);
mutex_lock(&ipcomp_resource_mutex);
ipcomp_free_data(ipcd);
mutex_unlock(&ipcomp_resource_mutex);
kfree(ipcd);
}
EXPORT_SYMBOL_GPL(ipcomp_destroy);
int ipcomp_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;
mutex_lock(&ipcomp_resource_mutex);
if (!ipcomp_alloc_scratches())
goto error;
ipcd->tfms = ipcomp_alloc_tfms(x->calg->alg_name);
if (!ipcd->tfms)
goto error;
mutex_unlock(&ipcomp_resource_mutex);
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:
ipcomp_free_data(ipcd);
mutex_unlock(&ipcomp_resource_mutex);
kfree(ipcd);
goto out;
}
EXPORT_SYMBOL_GPL(ipcomp_init_state);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp) - RFC3173");
MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");