Revision 9e2b7fa2df4365e99934901da4fb4af52d81e820 authored by Martin Willi on 06 November 2020, 07:30:30 UTC, committed by Jakub Kicinski on 12 November 2020, 15:47:06 UTC
VRF devices use an optimized direct path on output if a default qdisc is involved, calling Netfilter hooks directly. This path, however, does not consider Netfilter rules completing asynchronously, such as with NFQUEUE. The Netfilter okfn() is called for asynchronously accepted packets, but the VRF never passes that packet down the stack to send it out over the slave device. Using the slower redirect path for this seems not feasible, as we do not know beforehand if a Netfilter hook has asynchronously completing rules. Fix the use of asynchronously completing Netfilter rules in OUTPUT and POSTROUTING by using a special completion function that additionally calls dst_output() to pass the packet down the stack. Also, slightly adjust the use of nf_reset_ct() so that is called in the asynchronous case, too. Fixes: dcdd43c41e60 ("net: vrf: performance improvements for IPv4") Fixes: a9ec54d1b0cd ("net: vrf: performance improvements for IPv6") Signed-off-by: Martin Willi <martin@strongswan.org> Link: https://lore.kernel.org/r/20201106073030.3974927-1-martin@strongswan.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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cfb.c
//SPDX-License-Identifier: GPL-2.0
/*
* CFB: Cipher FeedBack mode
*
* Copyright (c) 2018 James.Bottomley@HansenPartnership.com
*
* CFB is a stream cipher mode which is layered on to a block
* encryption scheme. It works very much like a one time pad where
* the pad is generated initially from the encrypted IV and then
* subsequently from the encrypted previous block of ciphertext. The
* pad is XOR'd into the plain text to get the final ciphertext.
*
* The scheme of CFB is best described by wikipedia:
*
* https://en.wikipedia.org/wiki/Block_cipher_mode_of_operation#CFB
*
* Note that since the pad for both encryption and decryption is
* generated by an encryption operation, CFB never uses the block
* decryption function.
*/
#include <crypto/algapi.h>
#include <crypto/internal/skcipher.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/string.h>
static unsigned int crypto_cfb_bsize(struct crypto_skcipher *tfm)
{
return crypto_cipher_blocksize(skcipher_cipher_simple(tfm));
}
static void crypto_cfb_encrypt_one(struct crypto_skcipher *tfm,
const u8 *src, u8 *dst)
{
crypto_cipher_encrypt_one(skcipher_cipher_simple(tfm), dst, src);
}
/* final encrypt and decrypt is the same */
static void crypto_cfb_final(struct skcipher_walk *walk,
struct crypto_skcipher *tfm)
{
const unsigned long alignmask = crypto_skcipher_alignmask(tfm);
u8 tmp[MAX_CIPHER_BLOCKSIZE + MAX_CIPHER_ALIGNMASK];
u8 *stream = PTR_ALIGN(tmp + 0, alignmask + 1);
u8 *src = walk->src.virt.addr;
u8 *dst = walk->dst.virt.addr;
u8 *iv = walk->iv;
unsigned int nbytes = walk->nbytes;
crypto_cfb_encrypt_one(tfm, iv, stream);
crypto_xor_cpy(dst, stream, src, nbytes);
}
static int crypto_cfb_encrypt_segment(struct skcipher_walk *walk,
struct crypto_skcipher *tfm)
{
const unsigned int bsize = crypto_cfb_bsize(tfm);
unsigned int nbytes = walk->nbytes;
u8 *src = walk->src.virt.addr;
u8 *dst = walk->dst.virt.addr;
u8 *iv = walk->iv;
do {
crypto_cfb_encrypt_one(tfm, iv, dst);
crypto_xor(dst, src, bsize);
iv = dst;
src += bsize;
dst += bsize;
} while ((nbytes -= bsize) >= bsize);
memcpy(walk->iv, iv, bsize);
return nbytes;
}
static int crypto_cfb_encrypt_inplace(struct skcipher_walk *walk,
struct crypto_skcipher *tfm)
{
const unsigned int bsize = crypto_cfb_bsize(tfm);
unsigned int nbytes = walk->nbytes;
u8 *src = walk->src.virt.addr;
u8 *iv = walk->iv;
u8 tmp[MAX_CIPHER_BLOCKSIZE];
do {
crypto_cfb_encrypt_one(tfm, iv, tmp);
crypto_xor(src, tmp, bsize);
iv = src;
src += bsize;
} while ((nbytes -= bsize) >= bsize);
memcpy(walk->iv, iv, bsize);
return nbytes;
}
static int crypto_cfb_encrypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct skcipher_walk walk;
unsigned int bsize = crypto_cfb_bsize(tfm);
int err;
err = skcipher_walk_virt(&walk, req, false);
while (walk.nbytes >= bsize) {
if (walk.src.virt.addr == walk.dst.virt.addr)
err = crypto_cfb_encrypt_inplace(&walk, tfm);
else
err = crypto_cfb_encrypt_segment(&walk, tfm);
err = skcipher_walk_done(&walk, err);
}
if (walk.nbytes) {
crypto_cfb_final(&walk, tfm);
err = skcipher_walk_done(&walk, 0);
}
return err;
}
static int crypto_cfb_decrypt_segment(struct skcipher_walk *walk,
struct crypto_skcipher *tfm)
{
const unsigned int bsize = crypto_cfb_bsize(tfm);
unsigned int nbytes = walk->nbytes;
u8 *src = walk->src.virt.addr;
u8 *dst = walk->dst.virt.addr;
u8 *iv = walk->iv;
do {
crypto_cfb_encrypt_one(tfm, iv, dst);
crypto_xor(dst, src, bsize);
iv = src;
src += bsize;
dst += bsize;
} while ((nbytes -= bsize) >= bsize);
memcpy(walk->iv, iv, bsize);
return nbytes;
}
static int crypto_cfb_decrypt_inplace(struct skcipher_walk *walk,
struct crypto_skcipher *tfm)
{
const unsigned int bsize = crypto_cfb_bsize(tfm);
unsigned int nbytes = walk->nbytes;
u8 *src = walk->src.virt.addr;
u8 * const iv = walk->iv;
u8 tmp[MAX_CIPHER_BLOCKSIZE];
do {
crypto_cfb_encrypt_one(tfm, iv, tmp);
memcpy(iv, src, bsize);
crypto_xor(src, tmp, bsize);
src += bsize;
} while ((nbytes -= bsize) >= bsize);
return nbytes;
}
static int crypto_cfb_decrypt_blocks(struct skcipher_walk *walk,
struct crypto_skcipher *tfm)
{
if (walk->src.virt.addr == walk->dst.virt.addr)
return crypto_cfb_decrypt_inplace(walk, tfm);
else
return crypto_cfb_decrypt_segment(walk, tfm);
}
static int crypto_cfb_decrypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct skcipher_walk walk;
const unsigned int bsize = crypto_cfb_bsize(tfm);
int err;
err = skcipher_walk_virt(&walk, req, false);
while (walk.nbytes >= bsize) {
err = crypto_cfb_decrypt_blocks(&walk, tfm);
err = skcipher_walk_done(&walk, err);
}
if (walk.nbytes) {
crypto_cfb_final(&walk, tfm);
err = skcipher_walk_done(&walk, 0);
}
return err;
}
static int crypto_cfb_create(struct crypto_template *tmpl, struct rtattr **tb)
{
struct skcipher_instance *inst;
struct crypto_alg *alg;
int err;
inst = skcipher_alloc_instance_simple(tmpl, tb);
if (IS_ERR(inst))
return PTR_ERR(inst);
alg = skcipher_ialg_simple(inst);
/* CFB mode is a stream cipher. */
inst->alg.base.cra_blocksize = 1;
/*
* To simplify the implementation, configure the skcipher walk to only
* give a partial block at the very end, never earlier.
*/
inst->alg.chunksize = alg->cra_blocksize;
inst->alg.encrypt = crypto_cfb_encrypt;
inst->alg.decrypt = crypto_cfb_decrypt;
err = skcipher_register_instance(tmpl, inst);
if (err)
inst->free(inst);
return err;
}
static struct crypto_template crypto_cfb_tmpl = {
.name = "cfb",
.create = crypto_cfb_create,
.module = THIS_MODULE,
};
static int __init crypto_cfb_module_init(void)
{
return crypto_register_template(&crypto_cfb_tmpl);
}
static void __exit crypto_cfb_module_exit(void)
{
crypto_unregister_template(&crypto_cfb_tmpl);
}
subsys_initcall(crypto_cfb_module_init);
module_exit(crypto_cfb_module_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("CFB block cipher mode of operation");
MODULE_ALIAS_CRYPTO("cfb");
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