![Herbert Xu](/assets/img/avatar_default.png)
While BEET can theoretically work with IPComp the current code can't do that because it tries to construct a BEET mode tunnel type which doesn't (and cannot) exist. In fact as it is it won't even attach a tunnel object at all for BEET which is bogus. To support this fully we'd also need to change the policy checks on input to recognise a plain tunnel as a legal variant of an optional BEET transform. This patch simply fails such constructions for now. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
483 lines
10 KiB
C
483 lines
10 KiB
C
/*
|
|
* IP Payload Compression Protocol (IPComp) - RFC3173.
|
|
*
|
|
* Copyright (c) 2003 James Morris <jmorris@intercode.com.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/module.h>
|
|
#include <asm/semaphore.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 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;
|
|
skb->transport_header = skb->network_header + sizeof(*ipch);
|
|
__skb_pull(skb, sizeof(*ipch));
|
|
err = ipcomp_decompress(x, skb);
|
|
if (err)
|
|
goto out;
|
|
|
|
err = ipch->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 = crypto_comp_compress(tfm, start, plen, scratch, &dlen);
|
|
|
|
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;
|
|
}
|
|
|
|
static void ipcomp4_err(struct sk_buff *skb, u32 info)
|
|
{
|
|
__be32 spi;
|
|
struct iphdr *iph = (struct iphdr *)skb->data;
|
|
struct ip_comp_hdr *ipch = (struct ip_comp_hdr *)(skb->data+(iph->ihl<<2));
|
|
struct xfrm_state *x;
|
|
|
|
if (icmp_hdr(skb)->type != ICMP_DEST_UNREACH ||
|
|
icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
|
|
return;
|
|
|
|
spi = htonl(ntohs(ipch->cpi));
|
|
x = xfrm_state_lookup((xfrm_address_t *)&iph->daddr,
|
|
spi, IPPROTO_COMP, AF_INET);
|
|
if (!x)
|
|
return;
|
|
NETDEBUG(KERN_DEBUG "pmtu discovery on SA IPCOMP/%08x/%u.%u.%u.%u\n",
|
|
spi, NIPQUAD(iph->daddr));
|
|
xfrm_state_put(x);
|
|
}
|
|
|
|
/* We always hold one tunnel user reference to indicate a tunnel */
|
|
static struct xfrm_state *ipcomp_tunnel_create(struct xfrm_state *x)
|
|
{
|
|
struct xfrm_state *t;
|
|
|
|
t = xfrm_state_alloc();
|
|
if (t == NULL)
|
|
goto out;
|
|
|
|
t->id.proto = IPPROTO_IPIP;
|
|
t->id.spi = x->props.saddr.a4;
|
|
t->id.daddr.a4 = x->id.daddr.a4;
|
|
memcpy(&t->sel, &x->sel, sizeof(t->sel));
|
|
t->props.family = AF_INET;
|
|
t->props.mode = x->props.mode;
|
|
t->props.saddr.a4 = x->props.saddr.a4;
|
|
t->props.flags = x->props.flags;
|
|
|
|
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;
|
|
}
|
|
|
|
/*
|
|
* Must be protected by xfrm_cfg_mutex. State and tunnel user references are
|
|
* always incremented on success.
|
|
*/
|
|
static int ipcomp_tunnel_attach(struct xfrm_state *x)
|
|
{
|
|
int err = 0;
|
|
struct xfrm_state *t;
|
|
|
|
t = xfrm_state_lookup((xfrm_address_t *)&x->id.daddr.a4,
|
|
x->props.saddr.a4, IPPROTO_IPIP, AF_INET);
|
|
if (!t) {
|
|
t = ipcomp_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 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)
|
|
{
|
|
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 iphdr);
|
|
break;
|
|
default:
|
|
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);
|
|
|
|
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);
|
|
goto out;
|
|
}
|
|
|
|
static struct xfrm_type ipcomp_type = {
|
|
.description = "IPCOMP4",
|
|
.owner = THIS_MODULE,
|
|
.proto = IPPROTO_COMP,
|
|
.init_state = ipcomp_init_state,
|
|
.destructor = ipcomp_destroy,
|
|
.input = ipcomp_input,
|
|
.output = ipcomp_output
|
|
};
|
|
|
|
static struct net_protocol ipcomp4_protocol = {
|
|
.handler = xfrm4_rcv,
|
|
.err_handler = ipcomp4_err,
|
|
.no_policy = 1,
|
|
};
|
|
|
|
static int __init ipcomp4_init(void)
|
|
{
|
|
if (xfrm_register_type(&ipcomp_type, AF_INET) < 0) {
|
|
printk(KERN_INFO "ipcomp init: can't add xfrm type\n");
|
|
return -EAGAIN;
|
|
}
|
|
if (inet_add_protocol(&ipcomp4_protocol, IPPROTO_COMP) < 0) {
|
|
printk(KERN_INFO "ipcomp init: can't add protocol\n");
|
|
xfrm_unregister_type(&ipcomp_type, AF_INET);
|
|
return -EAGAIN;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static void __exit ipcomp4_fini(void)
|
|
{
|
|
if (inet_del_protocol(&ipcomp4_protocol, IPPROTO_COMP) < 0)
|
|
printk(KERN_INFO "ip ipcomp close: can't remove protocol\n");
|
|
if (xfrm_unregister_type(&ipcomp_type, AF_INET) < 0)
|
|
printk(KERN_INFO "ip ipcomp close: can't remove xfrm type\n");
|
|
}
|
|
|
|
module_init(ipcomp4_init);
|
|
module_exit(ipcomp4_fini);
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp) - RFC3173");
|
|
MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");
|
|
|
|
MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_COMP);
|