android_kernel_motorola_sm6225/net/xfrm/xfrm_ipcomp.c
Herbert Xu 9498c05820 ipcomp: Remove spurious truesize increase
When I made ipcomp use frags, I forgot to take out the original
truesize update that was added for pskb_expand_head.  As we no
longer expand the head of skb, that update should have been removed.

This bug is not related to the truesize warnings since we only
made it bigger than what it should've been.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-01-11 00:04:11 -08:00

383 lines
7.5 KiB
C

/*
* 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/gfp.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/percpu.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);
int len;
if (err)
goto out;
if (dlen < (plen + sizeof(struct ip_comp_hdr))) {
err = -EINVAL;
goto out;
}
len = dlen - plen;
if (len > skb_tailroom(skb))
len = skb_tailroom(skb);
__skb_put(skb, len);
len += plen;
skb_copy_to_linear_data(skb, scratch, len);
while ((scratch += len, dlen -= len) > 0) {
skb_frag_t *frag;
err = -EMSGSIZE;
if (WARN_ON(skb_shinfo(skb)->nr_frags >= MAX_SKB_FRAGS))
goto out;
frag = skb_shinfo(skb)->frags + skb_shinfo(skb)->nr_frags;
frag->page = alloc_page(GFP_ATOMIC);
err = -ENOMEM;
if (!frag->page)
goto out;
len = PAGE_SIZE;
if (dlen < len)
len = dlen;
memcpy(page_address(frag->page), scratch, len);
frag->page_offset = 0;
frag->size = len;
skb->truesize += len;
skb->data_len += len;
skb->len += len;
skb_shinfo(skb)->nr_frags++;
}
err = 0;
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;
}
WARN_ON(!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>");