linux/net/xfrm/xfrm_algo.c
David Howells 716ea3a7aa [NET]: Move generic skbuff stuff from XFRM code to generic code
Move generic skbuff stuff from XFRM code to generic code so that
AF_RXRPC can use it too.

The kdoc comments I've attached to the functions needs to be checked
by whoever wrote them as I had to make some guesses about the workings
of these functions.

Signed-off-By: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2007-04-25 22:28:33 -07:00

625 lines
11 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/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 = "hmac(digest_null)",
.compat = "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 = "hmac(md5)",
.compat = "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 = "hmac(sha1)",
.compat = "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 = "hmac(sha256)",
.compat = "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 = "hmac(ripemd160)",
.compat = "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
}
},
{
.name = "xcbc(aes)",
.uinfo = {
.auth = {
.icv_truncbits = 96,
.icv_fullbits = 128,
}
},
.desc = {
.sadb_alg_id = SADB_X_AALG_AES_XCBC_MAC,
.sadb_alg_ivlen = 0,
.sadb_alg_minbits = 128,
.sadb_alg_maxbits = 128
}
},
};
static struct xfrm_algo_desc ealg_list[] = {
{
.name = "ecb(cipher_null)",
.compat = "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 = "cbc(des)",
.compat = "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 = "cbc(des3_ede)",
.compat = "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 = "cbc(cast128)",
.compat = "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 = "cbc(blowfish)",
.compat = "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 = "cbc(aes)",
.compat = "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 = "cbc(serpent)",
.compat = "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 = "cbc(camellia)",
.uinfo = {
.encr = {
.blockbits = 128,
.defkeybits = 128,
}
},
.desc = {
.sadb_alg_id = SADB_X_EALG_CAMELLIACBC,
.sadb_alg_ivlen = 8,
.sadb_alg_minbits = 128,
.sadb_alg_maxbits = 256
}
},
{
.name = "cbc(twofish)",
.compat = "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, u32 type, u32 mask,
char *name, int probe)
{
int i, status;
if (!name)
return NULL;
for (i = 0; i < entries; i++) {
if (strcmp(name, list[i].name) &&
(!list[i].compat || strcmp(name, list[i].compat)))
continue;
if (list[i].available)
return &list[i];
if (!probe)
break;
status = crypto_has_alg(list[i].name, type,
mask | CRYPTO_ALG_ASYNC);
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(),
CRYPTO_ALG_TYPE_HASH, CRYPTO_ALG_TYPE_HASH_MASK,
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(),
CRYPTO_ALG_TYPE_BLKCIPHER, CRYPTO_ALG_TYPE_MASK,
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(),
CRYPTO_ALG_TYPE_COMPRESS, CRYPTO_ALG_TYPE_MASK,
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_has_hash(aalg_list[i].name, 0,
CRYPTO_ALG_ASYNC);
if (aalg_list[i].available != status)
aalg_list[i].available = status;
}
for (i = 0; i < ealg_entries(); i++) {
status = crypto_has_blkcipher(ealg_list[i].name, 0,
CRYPTO_ALG_ASYNC);
if (ealg_list[i].available != status)
ealg_list[i].available = status;
}
for (i = 0; i < calg_entries(); i++) {
status = crypto_has_comp(calg_list[i].name, 0,
CRYPTO_ALG_ASYNC);
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. */
int skb_icv_walk(const struct sk_buff *skb, struct hash_desc *desc,
int offset, int len, icv_update_fn_t icv_update)
{
int start = skb_headlen(skb);
int i, copy = start - offset;
int err;
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;
err = icv_update(desc, &sg, copy);
if (unlikely(err))
return err;
if ((len -= copy) == 0)
return 0;
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;
err = icv_update(desc, &sg, copy);
if (unlikely(err))
return err;
if (!(len -= copy))
return 0;
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;
err = skb_icv_walk(list, desc, offset-start,
copy, icv_update);
if (unlikely(err))
return err;
if ((len -= copy) == 0)
return 0;
offset += copy;
}
start = end;
}
}
BUG_ON(len);
return 0;
}
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)
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