![Eric Dumazet](/assets/img/avatar_default.png)
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
504 lines
11 KiB
C
504 lines
11 KiB
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);
|
|
|
|
err = crypto_comp_compress(tfm, start, plen, scratch, &dlen);
|
|
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);
|