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linux/net/xfrm/xfrm_algo.c
Evgeniy Polyakov d48102007d [XFRM]: skb_cow_data() does not set proper owner for new skbs. 
It looks like skb_cow_data() does not set 
proper owner for newly created skb.

If we have several fragments for skb and some of them
are shared(?) or cloned (like in async IPsec) there 
might be a situation when we require recreating skb and 
thus using skb_copy() for it.
Newly created skb has neither a destructor nor a socket
assotiated with it, which must be copied from the old skb.
As far as I can see, current code sets destructor and socket
for the first one skb only and uses truesize of the first skb
only to increment sk_wmem_alloc value.

If above "analysis" is correct then attached patch fixes that.

Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-05-18 22:51:45 -07:00

730 lines
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/*
* xfrm algorithm interface
*
* Copyright (c) 2002 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.
*/
#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/pfkeyv2.h>
#include <linux/crypto.h>
#include <net/xfrm.h>
#if defined(CONFIG_INET_AH) || defined(CONFIG_INET_AH_MODULE) || defined(CONFIG_INET6_AH) || defined(CONFIG_INET6_AH_MODULE)
#include <net/ah.h>
#endif
#if defined(CONFIG_INET_ESP) || defined(CONFIG_INET_ESP_MODULE) || defined(CONFIG_INET6_ESP) || defined(CONFIG_INET6_ESP_MODULE)
#include <net/esp.h>
#endif
#include <asm/scatterlist.h>
/*
* Algorithms supported by IPsec. These entries contain properties which
* are used in key negotiation and xfrm processing, and are used to verify
* that instantiated crypto transforms have correct parameters for IPsec
* purposes.
*/
static struct xfrm_algo_desc aalg_list[] = {
{
.name = "digest_null",
.uinfo = {
.auth = {
.icv_truncbits = 0,
.icv_fullbits = 0,
}
},
.desc = {
.sadb_alg_id = SADB_X_AALG_NULL,
.sadb_alg_ivlen = 0,
.sadb_alg_minbits = 0,
.sadb_alg_maxbits = 0
}
},
{
.name = "md5",
.uinfo = {
.auth = {
.icv_truncbits = 96,
.icv_fullbits = 128,
}
},
.desc = {
.sadb_alg_id = SADB_AALG_MD5HMAC,
.sadb_alg_ivlen = 0,
.sadb_alg_minbits = 128,
.sadb_alg_maxbits = 128
}
},
{
.name = "sha1",
.uinfo = {
.auth = {
.icv_truncbits = 96,
.icv_fullbits = 160,
}
},
.desc = {
.sadb_alg_id = SADB_AALG_SHA1HMAC,
.sadb_alg_ivlen = 0,
.sadb_alg_minbits = 160,
.sadb_alg_maxbits = 160
}
},
{
.name = "sha256",
.uinfo = {
.auth = {
.icv_truncbits = 96,
.icv_fullbits = 256,
}
},
.desc = {
.sadb_alg_id = SADB_X_AALG_SHA2_256HMAC,
.sadb_alg_ivlen = 0,
.sadb_alg_minbits = 256,
.sadb_alg_maxbits = 256
}
},
{
.name = "ripemd160",
.uinfo = {
.auth = {
.icv_truncbits = 96,
.icv_fullbits = 160,
}
},
.desc = {
.sadb_alg_id = SADB_X_AALG_RIPEMD160HMAC,
.sadb_alg_ivlen = 0,
.sadb_alg_minbits = 160,
.sadb_alg_maxbits = 160
}
},
};
static struct xfrm_algo_desc ealg_list[] = {
{
.name = "cipher_null",
.uinfo = {
.encr = {
.blockbits = 8,
.defkeybits = 0,
}
},
.desc = {
.sadb_alg_id = SADB_EALG_NULL,
.sadb_alg_ivlen = 0,
.sadb_alg_minbits = 0,
.sadb_alg_maxbits = 0
}
},
{
.name = "des",
.uinfo = {
.encr = {
.blockbits = 64,
.defkeybits = 64,
}
},
.desc = {
.sadb_alg_id = SADB_EALG_DESCBC,
.sadb_alg_ivlen = 8,
.sadb_alg_minbits = 64,
.sadb_alg_maxbits = 64
}
},
{
.name = "des3_ede",
.uinfo = {
.encr = {
.blockbits = 64,
.defkeybits = 192,
}
},
.desc = {
.sadb_alg_id = SADB_EALG_3DESCBC,
.sadb_alg_ivlen = 8,
.sadb_alg_minbits = 192,
.sadb_alg_maxbits = 192
}
},
{
.name = "cast128",
.uinfo = {
.encr = {
.blockbits = 64,
.defkeybits = 128,
}
},
.desc = {
.sadb_alg_id = SADB_X_EALG_CASTCBC,
.sadb_alg_ivlen = 8,
.sadb_alg_minbits = 40,
.sadb_alg_maxbits = 128
}
},
{
.name = "blowfish",
.uinfo = {
.encr = {
.blockbits = 64,
.defkeybits = 128,
}
},
.desc = {
.sadb_alg_id = SADB_X_EALG_BLOWFISHCBC,
.sadb_alg_ivlen = 8,
.sadb_alg_minbits = 40,
.sadb_alg_maxbits = 448
}
},
{
.name = "aes",
.uinfo = {
.encr = {
.blockbits = 128,
.defkeybits = 128,
}
},
.desc = {
.sadb_alg_id = SADB_X_EALG_AESCBC,
.sadb_alg_ivlen = 8,
.sadb_alg_minbits = 128,
.sadb_alg_maxbits = 256
}
},
{
.name = "serpent",
.uinfo = {
.encr = {
.blockbits = 128,
.defkeybits = 128,
}
},
.desc = {
.sadb_alg_id = SADB_X_EALG_SERPENTCBC,
.sadb_alg_ivlen = 8,
.sadb_alg_minbits = 128,
.sadb_alg_maxbits = 256,
}
},
{
.name = "twofish",
.uinfo = {
.encr = {
.blockbits = 128,
.defkeybits = 128,
}
},
.desc = {
.sadb_alg_id = SADB_X_EALG_TWOFISHCBC,
.sadb_alg_ivlen = 8,
.sadb_alg_minbits = 128,
.sadb_alg_maxbits = 256
}
},
};
static struct xfrm_algo_desc calg_list[] = {
{
.name = "deflate",
.uinfo = {
.comp = {
.threshold = 90,
}
},
.desc = { .sadb_alg_id = SADB_X_CALG_DEFLATE }
},
{
.name = "lzs",
.uinfo = {
.comp = {
.threshold = 90,
}
},
.desc = { .sadb_alg_id = SADB_X_CALG_LZS }
},
{
.name = "lzjh",
.uinfo = {
.comp = {
.threshold = 50,
}
},
.desc = { .sadb_alg_id = SADB_X_CALG_LZJH }
},
};
static inline int aalg_entries(void)
{
return ARRAY_SIZE(aalg_list);
}
static inline int ealg_entries(void)
{
return ARRAY_SIZE(ealg_list);
}
static inline int calg_entries(void)
{
return ARRAY_SIZE(calg_list);
}
/* Todo: generic iterators */
struct xfrm_algo_desc *xfrm_aalg_get_byid(int alg_id)
{
int i;
for (i = 0; i < aalg_entries(); i++) {
if (aalg_list[i].desc.sadb_alg_id == alg_id) {
if (aalg_list[i].available)
return &aalg_list[i];
else
break;
}
}
return NULL;
}
EXPORT_SYMBOL_GPL(xfrm_aalg_get_byid);
struct xfrm_algo_desc *xfrm_ealg_get_byid(int alg_id)
{
int i;
for (i = 0; i < ealg_entries(); i++) {
if (ealg_list[i].desc.sadb_alg_id == alg_id) {
if (ealg_list[i].available)
return &ealg_list[i];
else
break;
}
}
return NULL;
}
EXPORT_SYMBOL_GPL(xfrm_ealg_get_byid);
struct xfrm_algo_desc *xfrm_calg_get_byid(int alg_id)
{
int i;
for (i = 0; i < calg_entries(); i++) {
if (calg_list[i].desc.sadb_alg_id == alg_id) {
if (calg_list[i].available)
return &calg_list[i];
else
break;
}
}
return NULL;
}
EXPORT_SYMBOL_GPL(xfrm_calg_get_byid);
static struct xfrm_algo_desc *xfrm_get_byname(struct xfrm_algo_desc *list,
int entries, char *name,
int probe)
{
int i, status;
if (!name)
return NULL;
for (i = 0; i < entries; i++) {
if (strcmp(name, list[i].name))
continue;
if (list[i].available)
return &list[i];
if (!probe)
break;
status = crypto_alg_available(name, 0);
if (!status)
break;
list[i].available = status;
return &list[i];
}
return NULL;
}
struct xfrm_algo_desc *xfrm_aalg_get_byname(char *name, int probe)
{
return xfrm_get_byname(aalg_list, aalg_entries(), name, probe);
}
EXPORT_SYMBOL_GPL(xfrm_aalg_get_byname);
struct xfrm_algo_desc *xfrm_ealg_get_byname(char *name, int probe)
{
return xfrm_get_byname(ealg_list, ealg_entries(), name, probe);
}
EXPORT_SYMBOL_GPL(xfrm_ealg_get_byname);
struct xfrm_algo_desc *xfrm_calg_get_byname(char *name, int probe)
{
return xfrm_get_byname(calg_list, calg_entries(), name, probe);
}
EXPORT_SYMBOL_GPL(xfrm_calg_get_byname);
struct xfrm_algo_desc *xfrm_aalg_get_byidx(unsigned int idx)
{
if (idx >= aalg_entries())
return NULL;
return &aalg_list[idx];
}
EXPORT_SYMBOL_GPL(xfrm_aalg_get_byidx);
struct xfrm_algo_desc *xfrm_ealg_get_byidx(unsigned int idx)
{
if (idx >= ealg_entries())
return NULL;
return &ealg_list[idx];
}
EXPORT_SYMBOL_GPL(xfrm_ealg_get_byidx);
/*
* Probe for the availability of crypto algorithms, and set the available
* flag for any algorithms found on the system. This is typically called by
* pfkey during userspace SA add, update or register.
*/
void xfrm_probe_algs(void)
{
#ifdef CONFIG_CRYPTO
int i, status;
BUG_ON(in_softirq());
for (i = 0; i < aalg_entries(); i++) {
status = crypto_alg_available(aalg_list[i].name, 0);
if (aalg_list[i].available != status)
aalg_list[i].available = status;
}
for (i = 0; i < ealg_entries(); i++) {
status = crypto_alg_available(ealg_list[i].name, 0);
if (ealg_list[i].available != status)
ealg_list[i].available = status;
}
for (i = 0; i < calg_entries(); i++) {
status = crypto_alg_available(calg_list[i].name, 0);
if (calg_list[i].available != status)
calg_list[i].available = status;
}
#endif
}
EXPORT_SYMBOL_GPL(xfrm_probe_algs);
int xfrm_count_auth_supported(void)
{
int i, n;
for (i = 0, n = 0; i < aalg_entries(); i++)
if (aalg_list[i].available)
n++;
return n;
}
EXPORT_SYMBOL_GPL(xfrm_count_auth_supported);
int xfrm_count_enc_supported(void)
{
int i, n;
for (i = 0, n = 0; i < ealg_entries(); i++)
if (ealg_list[i].available)
n++;
return n;
}
EXPORT_SYMBOL_GPL(xfrm_count_enc_supported);
/* Move to common area: it is shared with AH. */
void skb_icv_walk(const struct sk_buff *skb, struct crypto_tfm *tfm,
int offset, int len, icv_update_fn_t icv_update)
{
int start = skb_headlen(skb);
int i, copy = start - offset;
struct scatterlist sg;
/* Checksum header. */
if (copy > 0) {
if (copy > len)
copy = len;
sg.page = virt_to_page(skb->data + offset);
sg.offset = (unsigned long)(skb->data + offset) % PAGE_SIZE;
sg.length = copy;
icv_update(tfm, &sg, 1);
if ((len -= copy) == 0)
return;
offset += copy;
}
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
int end;
BUG_TRAP(start <= offset + len);
end = start + skb_shinfo(skb)->frags[i].size;
if ((copy = end - offset) > 0) {
skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
if (copy > len)
copy = len;
sg.page = frag->page;
sg.offset = frag->page_offset + offset-start;
sg.length = copy;
icv_update(tfm, &sg, 1);
if (!(len -= copy))
return;
offset += copy;
}
start = end;
}
if (skb_shinfo(skb)->frag_list) {
struct sk_buff *list = skb_shinfo(skb)->frag_list;
for (; list; list = list->next) {
int end;
BUG_TRAP(start <= offset + len);
end = start + list->len;
if ((copy = end - offset) > 0) {
if (copy > len)
copy = len;
skb_icv_walk(list, tfm, offset-start, copy, icv_update);
if ((len -= copy) == 0)
return;
offset += copy;
}
start = end;
}
}
if (len)
BUG();
}
EXPORT_SYMBOL_GPL(skb_icv_walk);
#if defined(CONFIG_INET_ESP) || defined(CONFIG_INET_ESP_MODULE) || defined(CONFIG_INET6_ESP) || defined(CONFIG_INET6_ESP_MODULE)
/* Looking generic it is not used in another places. */
int
skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset, int len)
{
int start = skb_headlen(skb);
int i, copy = start - offset;
int elt = 0;
if (copy > 0) {
if (copy > len)
copy = len;
sg[elt].page = virt_to_page(skb->data + offset);
sg[elt].offset = (unsigned long)(skb->data + offset) % PAGE_SIZE;
sg[elt].length = copy;
elt++;
if ((len -= copy) == 0)
return elt;
offset += copy;
}
for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
int end;
BUG_TRAP(start <= offset + len);
end = start + skb_shinfo(skb)->frags[i].size;
if ((copy = end - offset) > 0) {
skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
if (copy > len)
copy = len;
sg[elt].page = frag->page;
sg[elt].offset = frag->page_offset+offset-start;
sg[elt].length = copy;
elt++;
if (!(len -= copy))
return elt;
offset += copy;
}
start = end;
}
if (skb_shinfo(skb)->frag_list) {
struct sk_buff *list = skb_shinfo(skb)->frag_list;
for (; list; list = list->next) {
int end;
BUG_TRAP(start <= offset + len);
end = start + list->len;
if ((copy = end - offset) > 0) {
if (copy > len)
copy = len;
elt += skb_to_sgvec(list, sg+elt, offset - start, copy);
if ((len -= copy) == 0)
return elt;
offset += copy;
}
start = end;
}
}
if (len)
BUG();
return elt;
}
EXPORT_SYMBOL_GPL(skb_to_sgvec);
/* Check that skb data bits are writable. If they are not, copy data
* to newly created private area. If "tailbits" is given, make sure that
* tailbits bytes beyond current end of skb are writable.
*
* Returns amount of elements of scatterlist to load for subsequent
* transformations and pointer to writable trailer skb.
*/
int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer)
{
int copyflag;
int elt;
struct sk_buff *skb1, **skb_p;
/* If skb is cloned or its head is paged, reallocate
* head pulling out all the pages (pages are considered not writable
* at the moment even if they are anonymous).
*/
if ((skb_cloned(skb) || skb_shinfo(skb)->nr_frags) &&
__pskb_pull_tail(skb, skb_pagelen(skb)-skb_headlen(skb)) == NULL)
return -ENOMEM;
/* Easy case. Most of packets will go this way. */
if (!skb_shinfo(skb)->frag_list) {
/* A little of trouble, not enough of space for trailer.
* This should not happen, when stack is tuned to generate
* good frames. OK, on miss we reallocate and reserve even more
* space, 128 bytes is fair. */
if (skb_tailroom(skb) < tailbits &&
pskb_expand_head(skb, 0, tailbits-skb_tailroom(skb)+128, GFP_ATOMIC))
return -ENOMEM;
/* Voila! */
*trailer = skb;
return 1;
}
/* Misery. We are in troubles, going to mincer fragments... */
elt = 1;
skb_p = &skb_shinfo(skb)->frag_list;
copyflag = 0;
while ((skb1 = *skb_p) != NULL) {
int ntail = 0;
/* The fragment is partially pulled by someone,
* this can happen on input. Copy it and everything
* after it. */
if (skb_shared(skb1))
copyflag = 1;
/* If the skb is the last, worry about trailer. */
if (skb1->next == NULL && tailbits) {
if (skb_shinfo(skb1)->nr_frags ||
skb_shinfo(skb1)->frag_list ||
skb_tailroom(skb1) < tailbits)
ntail = tailbits + 128;
}
if (copyflag ||
skb_cloned(skb1) ||
ntail ||
skb_shinfo(skb1)->nr_frags ||
skb_shinfo(skb1)->frag_list) {
struct sk_buff *skb2;
/* Fuck, we are miserable poor guys... */
if (ntail == 0)
skb2 = skb_copy(skb1, GFP_ATOMIC);
else
skb2 = skb_copy_expand(skb1,
skb_headroom(skb1),
ntail,
GFP_ATOMIC);
if (unlikely(skb2 == NULL))
return -ENOMEM;
if (skb1->sk)
skb_set_owner_w(skb2, skb1->sk);
/* Looking around. Are we still alive?
* OK, link new skb, drop old one */
skb2->next = skb1->next;
*skb_p = skb2;
kfree_skb(skb1);
skb1 = skb2;
}
elt++;
*trailer = skb1;
skb_p = &skb1->next;
}
return elt;
}
EXPORT_SYMBOL_GPL(skb_cow_data);
void *pskb_put(struct sk_buff *skb, struct sk_buff *tail, int len)
{
if (tail != skb) {
skb->data_len += len;
skb->len += len;
}
return skb_put(tail, len);
}
EXPORT_SYMBOL_GPL(pskb_put);
#endif
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