mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 09:19:51 +00:00
730 lines
14 KiB
C
730 lines
14 KiB
C
![]() |
/*
|
||
|
* 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(skb, 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
|