![Jean Delvare](/assets/img/avatar_default.png)
I noticed recently that, in skb_checksum(), "offset" and "start" are essentially the same thing and have the same value throughout the function, despite being computed differently. Using a single variable allows some cleanups and makes the skb_checksum() function smaller, more readable, and presumably marginally faster. We appear to have many other "sk_buff walker" functions built on the exact same model, so the cleanup applies to them, too. Here is a list of the functions I found to be affected: net/appletalk/ddp.c:atalk_sum_skb() net/core/datagram.c:skb_copy_datagram_iovec() net/core/datagram.c:skb_copy_and_csum_datagram() net/core/skbuff.c:skb_copy_bits() net/core/skbuff.c:skb_store_bits() net/core/skbuff.c:skb_checksum() net/core/skbuff.c:skb_copy_and_csum_bit() net/core/user_dma.c:dma_skb_copy_datagram_iovec() net/xfrm/xfrm_algo.c:skb_icv_walk() net/xfrm/xfrm_algo.c:skb_to_sgvec() OTOH, I admit I'm a bit surprised, the cleanup is rather obvious so I'm really wondering if I am missing something. Can anyone please comment on this? Signed-off-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: David S. Miller <davem@davemloft.net>
619 lines
11 KiB
C
619 lines
11 KiB
C
/*
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* xfrm algorithm interface
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*
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* Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the Free
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* Software Foundation; either version 2 of the License, or (at your option)
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* any later version.
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*/
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/pfkeyv2.h>
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#include <linux/crypto.h>
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#include <net/xfrm.h>
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#if defined(CONFIG_INET_AH) || defined(CONFIG_INET_AH_MODULE) || defined(CONFIG_INET6_AH) || defined(CONFIG_INET6_AH_MODULE)
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#include <net/ah.h>
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#endif
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#if defined(CONFIG_INET_ESP) || defined(CONFIG_INET_ESP_MODULE) || defined(CONFIG_INET6_ESP) || defined(CONFIG_INET6_ESP_MODULE)
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#include <net/esp.h>
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#endif
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#include <asm/scatterlist.h>
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/*
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* Algorithms supported by IPsec. These entries contain properties which
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* are used in key negotiation and xfrm processing, and are used to verify
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* that instantiated crypto transforms have correct parameters for IPsec
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* purposes.
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*/
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static struct xfrm_algo_desc aalg_list[] = {
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{
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.name = "hmac(digest_null)",
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.compat = "digest_null",
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.uinfo = {
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.auth = {
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.icv_truncbits = 0,
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.icv_fullbits = 0,
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}
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},
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.desc = {
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.sadb_alg_id = SADB_X_AALG_NULL,
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.sadb_alg_ivlen = 0,
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.sadb_alg_minbits = 0,
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.sadb_alg_maxbits = 0
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}
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},
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{
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.name = "hmac(md5)",
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.compat = "md5",
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.uinfo = {
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.auth = {
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.icv_truncbits = 96,
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.icv_fullbits = 128,
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}
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},
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.desc = {
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.sadb_alg_id = SADB_AALG_MD5HMAC,
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.sadb_alg_ivlen = 0,
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.sadb_alg_minbits = 128,
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.sadb_alg_maxbits = 128
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}
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},
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{
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.name = "hmac(sha1)",
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.compat = "sha1",
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.uinfo = {
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.auth = {
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.icv_truncbits = 96,
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.icv_fullbits = 160,
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}
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},
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.desc = {
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.sadb_alg_id = SADB_AALG_SHA1HMAC,
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.sadb_alg_ivlen = 0,
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.sadb_alg_minbits = 160,
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.sadb_alg_maxbits = 160
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}
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},
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{
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.name = "hmac(sha256)",
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.compat = "sha256",
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.uinfo = {
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.auth = {
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.icv_truncbits = 96,
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.icv_fullbits = 256,
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}
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},
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.desc = {
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.sadb_alg_id = SADB_X_AALG_SHA2_256HMAC,
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.sadb_alg_ivlen = 0,
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.sadb_alg_minbits = 256,
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.sadb_alg_maxbits = 256
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}
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},
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{
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.name = "hmac(ripemd160)",
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.compat = "ripemd160",
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.uinfo = {
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.auth = {
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.icv_truncbits = 96,
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.icv_fullbits = 160,
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}
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},
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.desc = {
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.sadb_alg_id = SADB_X_AALG_RIPEMD160HMAC,
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.sadb_alg_ivlen = 0,
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.sadb_alg_minbits = 160,
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.sadb_alg_maxbits = 160
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}
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},
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{
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.name = "xcbc(aes)",
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.uinfo = {
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.auth = {
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.icv_truncbits = 96,
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.icv_fullbits = 128,
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}
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},
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.desc = {
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.sadb_alg_id = SADB_X_AALG_AES_XCBC_MAC,
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.sadb_alg_ivlen = 0,
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.sadb_alg_minbits = 128,
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.sadb_alg_maxbits = 128
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}
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},
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};
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static struct xfrm_algo_desc ealg_list[] = {
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{
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.name = "ecb(cipher_null)",
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.compat = "cipher_null",
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.uinfo = {
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.encr = {
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.blockbits = 8,
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.defkeybits = 0,
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}
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},
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.desc = {
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.sadb_alg_id = SADB_EALG_NULL,
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.sadb_alg_ivlen = 0,
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.sadb_alg_minbits = 0,
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.sadb_alg_maxbits = 0
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}
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},
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{
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.name = "cbc(des)",
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.compat = "des",
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.uinfo = {
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.encr = {
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.blockbits = 64,
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.defkeybits = 64,
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}
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},
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.desc = {
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.sadb_alg_id = SADB_EALG_DESCBC,
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.sadb_alg_ivlen = 8,
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.sadb_alg_minbits = 64,
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.sadb_alg_maxbits = 64
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}
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},
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{
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.name = "cbc(des3_ede)",
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.compat = "des3_ede",
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.uinfo = {
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.encr = {
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.blockbits = 64,
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.defkeybits = 192,
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}
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},
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.desc = {
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.sadb_alg_id = SADB_EALG_3DESCBC,
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.sadb_alg_ivlen = 8,
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.sadb_alg_minbits = 192,
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.sadb_alg_maxbits = 192
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}
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},
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{
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.name = "cbc(cast128)",
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.compat = "cast128",
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.uinfo = {
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.encr = {
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.blockbits = 64,
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.defkeybits = 128,
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}
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},
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.desc = {
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.sadb_alg_id = SADB_X_EALG_CASTCBC,
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.sadb_alg_ivlen = 8,
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.sadb_alg_minbits = 40,
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.sadb_alg_maxbits = 128
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}
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},
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{
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.name = "cbc(blowfish)",
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.compat = "blowfish",
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.uinfo = {
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.encr = {
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.blockbits = 64,
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.defkeybits = 128,
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}
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},
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.desc = {
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.sadb_alg_id = SADB_X_EALG_BLOWFISHCBC,
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.sadb_alg_ivlen = 8,
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.sadb_alg_minbits = 40,
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.sadb_alg_maxbits = 448
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}
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},
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{
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.name = "cbc(aes)",
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.compat = "aes",
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.uinfo = {
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.encr = {
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.blockbits = 128,
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.defkeybits = 128,
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}
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},
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.desc = {
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.sadb_alg_id = SADB_X_EALG_AESCBC,
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.sadb_alg_ivlen = 8,
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.sadb_alg_minbits = 128,
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.sadb_alg_maxbits = 256
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}
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},
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{
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.name = "cbc(serpent)",
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.compat = "serpent",
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.uinfo = {
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.encr = {
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.blockbits = 128,
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.defkeybits = 128,
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}
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},
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.desc = {
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.sadb_alg_id = SADB_X_EALG_SERPENTCBC,
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.sadb_alg_ivlen = 8,
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.sadb_alg_minbits = 128,
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.sadb_alg_maxbits = 256,
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}
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},
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{
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.name = "cbc(camellia)",
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.uinfo = {
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.encr = {
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.blockbits = 128,
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.defkeybits = 128,
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}
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},
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.desc = {
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.sadb_alg_id = SADB_X_EALG_CAMELLIACBC,
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.sadb_alg_ivlen = 8,
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.sadb_alg_minbits = 128,
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.sadb_alg_maxbits = 256
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}
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},
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{
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.name = "cbc(twofish)",
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.compat = "twofish",
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.uinfo = {
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.encr = {
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.blockbits = 128,
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.defkeybits = 128,
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}
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},
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.desc = {
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.sadb_alg_id = SADB_X_EALG_TWOFISHCBC,
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.sadb_alg_ivlen = 8,
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.sadb_alg_minbits = 128,
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.sadb_alg_maxbits = 256
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}
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},
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};
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static struct xfrm_algo_desc calg_list[] = {
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{
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.name = "deflate",
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.uinfo = {
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.comp = {
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.threshold = 90,
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}
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},
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.desc = { .sadb_alg_id = SADB_X_CALG_DEFLATE }
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},
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{
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.name = "lzs",
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.uinfo = {
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.comp = {
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.threshold = 90,
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}
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},
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.desc = { .sadb_alg_id = SADB_X_CALG_LZS }
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},
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{
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.name = "lzjh",
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.uinfo = {
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.comp = {
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.threshold = 50,
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}
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},
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.desc = { .sadb_alg_id = SADB_X_CALG_LZJH }
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},
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};
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static inline int aalg_entries(void)
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{
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return ARRAY_SIZE(aalg_list);
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}
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static inline int ealg_entries(void)
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{
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return ARRAY_SIZE(ealg_list);
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}
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static inline int calg_entries(void)
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{
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return ARRAY_SIZE(calg_list);
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}
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/* Todo: generic iterators */
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struct xfrm_algo_desc *xfrm_aalg_get_byid(int alg_id)
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{
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int i;
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for (i = 0; i < aalg_entries(); i++) {
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if (aalg_list[i].desc.sadb_alg_id == alg_id) {
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if (aalg_list[i].available)
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return &aalg_list[i];
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else
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break;
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}
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}
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return NULL;
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}
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EXPORT_SYMBOL_GPL(xfrm_aalg_get_byid);
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struct xfrm_algo_desc *xfrm_ealg_get_byid(int alg_id)
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{
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int i;
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for (i = 0; i < ealg_entries(); i++) {
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if (ealg_list[i].desc.sadb_alg_id == alg_id) {
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if (ealg_list[i].available)
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return &ealg_list[i];
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else
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break;
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}
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}
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return NULL;
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}
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EXPORT_SYMBOL_GPL(xfrm_ealg_get_byid);
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struct xfrm_algo_desc *xfrm_calg_get_byid(int alg_id)
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{
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int i;
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for (i = 0; i < calg_entries(); i++) {
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if (calg_list[i].desc.sadb_alg_id == alg_id) {
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if (calg_list[i].available)
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return &calg_list[i];
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else
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break;
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}
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}
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return NULL;
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}
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EXPORT_SYMBOL_GPL(xfrm_calg_get_byid);
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static struct xfrm_algo_desc *xfrm_get_byname(struct xfrm_algo_desc *list,
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int entries, u32 type, u32 mask,
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char *name, int probe)
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{
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int i, status;
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if (!name)
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return NULL;
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for (i = 0; i < entries; i++) {
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if (strcmp(name, list[i].name) &&
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(!list[i].compat || strcmp(name, list[i].compat)))
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continue;
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if (list[i].available)
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return &list[i];
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if (!probe)
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break;
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status = crypto_has_alg(list[i].name, type,
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mask | CRYPTO_ALG_ASYNC);
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if (!status)
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break;
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list[i].available = status;
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return &list[i];
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}
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return NULL;
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}
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struct xfrm_algo_desc *xfrm_aalg_get_byname(char *name, int probe)
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{
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return xfrm_get_byname(aalg_list, aalg_entries(),
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CRYPTO_ALG_TYPE_HASH, CRYPTO_ALG_TYPE_HASH_MASK,
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name, probe);
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}
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EXPORT_SYMBOL_GPL(xfrm_aalg_get_byname);
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struct xfrm_algo_desc *xfrm_ealg_get_byname(char *name, int probe)
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{
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return xfrm_get_byname(ealg_list, ealg_entries(),
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CRYPTO_ALG_TYPE_BLKCIPHER, CRYPTO_ALG_TYPE_MASK,
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name, probe);
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}
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EXPORT_SYMBOL_GPL(xfrm_ealg_get_byname);
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struct xfrm_algo_desc *xfrm_calg_get_byname(char *name, int probe)
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{
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return xfrm_get_byname(calg_list, calg_entries(),
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CRYPTO_ALG_TYPE_COMPRESS, CRYPTO_ALG_TYPE_MASK,
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name, probe);
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}
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EXPORT_SYMBOL_GPL(xfrm_calg_get_byname);
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struct xfrm_algo_desc *xfrm_aalg_get_byidx(unsigned int idx)
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{
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if (idx >= aalg_entries())
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return NULL;
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return &aalg_list[idx];
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}
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EXPORT_SYMBOL_GPL(xfrm_aalg_get_byidx);
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struct xfrm_algo_desc *xfrm_ealg_get_byidx(unsigned int idx)
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{
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if (idx >= ealg_entries())
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return NULL;
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return &ealg_list[idx];
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}
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EXPORT_SYMBOL_GPL(xfrm_ealg_get_byidx);
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/*
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* Probe for the availability of crypto algorithms, and set the available
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* flag for any algorithms found on the system. This is typically called by
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* pfkey during userspace SA add, update or register.
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*/
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void xfrm_probe_algs(void)
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{
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#ifdef CONFIG_CRYPTO
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int i, status;
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BUG_ON(in_softirq());
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for (i = 0; i < aalg_entries(); i++) {
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status = crypto_has_hash(aalg_list[i].name, 0,
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CRYPTO_ALG_ASYNC);
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if (aalg_list[i].available != status)
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aalg_list[i].available = status;
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}
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for (i = 0; i < ealg_entries(); i++) {
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status = crypto_has_blkcipher(ealg_list[i].name, 0,
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CRYPTO_ALG_ASYNC);
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if (ealg_list[i].available != status)
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ealg_list[i].available = status;
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}
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for (i = 0; i < calg_entries(); i++) {
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status = crypto_has_comp(calg_list[i].name, 0,
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CRYPTO_ALG_ASYNC);
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if (calg_list[i].available != status)
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calg_list[i].available = status;
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}
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#endif
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}
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EXPORT_SYMBOL_GPL(xfrm_probe_algs);
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int xfrm_count_auth_supported(void)
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{
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int i, n;
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for (i = 0, n = 0; i < aalg_entries(); i++)
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if (aalg_list[i].available)
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n++;
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return n;
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}
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EXPORT_SYMBOL_GPL(xfrm_count_auth_supported);
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int xfrm_count_enc_supported(void)
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{
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int i, n;
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for (i = 0, n = 0; i < ealg_entries(); i++)
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if (ealg_list[i].available)
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n++;
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return n;
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}
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EXPORT_SYMBOL_GPL(xfrm_count_enc_supported);
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|
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/* Move to common area: it is shared with AH. */
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|
|
int skb_icv_walk(const struct sk_buff *skb, struct hash_desc *desc,
|
|
int offset, int len, icv_update_fn_t icv_update)
|
|
{
|
|
int end = skb_headlen(skb);
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|
int i, copy = end - 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++) {
|
|
BUG_TRAP(len >= 0);
|
|
|
|
end = offset + 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;
|
|
sg.length = copy;
|
|
|
|
err = icv_update(desc, &sg, copy);
|
|
if (unlikely(err))
|
|
return err;
|
|
|
|
if (!(len -= copy))
|
|
return 0;
|
|
offset += copy;
|
|
}
|
|
}
|
|
|
|
if (skb_shinfo(skb)->frag_list) {
|
|
struct sk_buff *list = skb_shinfo(skb)->frag_list;
|
|
|
|
for (; list; list = list->next) {
|
|
BUG_TRAP(len >= 0);
|
|
|
|
end = offset + list->len;
|
|
if ((copy = end - offset) > 0) {
|
|
if (copy > len)
|
|
copy = len;
|
|
err = skb_icv_walk(list, desc, 0,
|
|
copy, icv_update);
|
|
if (unlikely(err))
|
|
return err;
|
|
if ((len -= copy) == 0)
|
|
return 0;
|
|
offset += copy;
|
|
}
|
|
}
|
|
}
|
|
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
|