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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: Fix fast path output packet handling with async Netfilter rules
 
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>
1 parent 52755b6
Raw File
crc7.c 
// SPDX-License-Identifier: GPL-2.0-only
/*
 *      crc7.c
 */

#include <linux/types.h>
#include <linux/module.h>
#include <linux/crc7.h>


/*
 * Table for CRC-7 (polynomial x^7 + x^3 + 1).
 * This is a big-endian CRC (msbit is highest power of x),
 * aligned so the msbit of the byte is the x^6 coefficient
 * and the lsbit is not used.
 */
const u8 crc7_be_syndrome_table[256] = {
	0x00, 0x12, 0x24, 0x36, 0x48, 0x5a, 0x6c, 0x7e,
	0x90, 0x82, 0xb4, 0xa6, 0xd8, 0xca, 0xfc, 0xee,
	0x32, 0x20, 0x16, 0x04, 0x7a, 0x68, 0x5e, 0x4c,
	0xa2, 0xb0, 0x86, 0x94, 0xea, 0xf8, 0xce, 0xdc,
	0x64, 0x76, 0x40, 0x52, 0x2c, 0x3e, 0x08, 0x1a,
	0xf4, 0xe6, 0xd0, 0xc2, 0xbc, 0xae, 0x98, 0x8a,
	0x56, 0x44, 0x72, 0x60, 0x1e, 0x0c, 0x3a, 0x28,
	0xc6, 0xd4, 0xe2, 0xf0, 0x8e, 0x9c, 0xaa, 0xb8,
	0xc8, 0xda, 0xec, 0xfe, 0x80, 0x92, 0xa4, 0xb6,
	0x58, 0x4a, 0x7c, 0x6e, 0x10, 0x02, 0x34, 0x26,
	0xfa, 0xe8, 0xde, 0xcc, 0xb2, 0xa0, 0x96, 0x84,
	0x6a, 0x78, 0x4e, 0x5c, 0x22, 0x30, 0x06, 0x14,
	0xac, 0xbe, 0x88, 0x9a, 0xe4, 0xf6, 0xc0, 0xd2,
	0x3c, 0x2e, 0x18, 0x0a, 0x74, 0x66, 0x50, 0x42,
	0x9e, 0x8c, 0xba, 0xa8, 0xd6, 0xc4, 0xf2, 0xe0,
	0x0e, 0x1c, 0x2a, 0x38, 0x46, 0x54, 0x62, 0x70,
	0x82, 0x90, 0xa6, 0xb4, 0xca, 0xd8, 0xee, 0xfc,
	0x12, 0x00, 0x36, 0x24, 0x5a, 0x48, 0x7e, 0x6c,
	0xb0, 0xa2, 0x94, 0x86, 0xf8, 0xea, 0xdc, 0xce,
	0x20, 0x32, 0x04, 0x16, 0x68, 0x7a, 0x4c, 0x5e,
	0xe6, 0xf4, 0xc2, 0xd0, 0xae, 0xbc, 0x8a, 0x98,
	0x76, 0x64, 0x52, 0x40, 0x3e, 0x2c, 0x1a, 0x08,
	0xd4, 0xc6, 0xf0, 0xe2, 0x9c, 0x8e, 0xb8, 0xaa,
	0x44, 0x56, 0x60, 0x72, 0x0c, 0x1e, 0x28, 0x3a,
	0x4a, 0x58, 0x6e, 0x7c, 0x02, 0x10, 0x26, 0x34,
	0xda, 0xc8, 0xfe, 0xec, 0x92, 0x80, 0xb6, 0xa4,
	0x78, 0x6a, 0x5c, 0x4e, 0x30, 0x22, 0x14, 0x06,
	0xe8, 0xfa, 0xcc, 0xde, 0xa0, 0xb2, 0x84, 0x96,
	0x2e, 0x3c, 0x0a, 0x18, 0x66, 0x74, 0x42, 0x50,
	0xbe, 0xac, 0x9a, 0x88, 0xf6, 0xe4, 0xd2, 0xc0,
	0x1c, 0x0e, 0x38, 0x2a, 0x54, 0x46, 0x70, 0x62,
	0x8c, 0x9e, 0xa8, 0xba, 0xc4, 0xd6, 0xe0, 0xf2
};
EXPORT_SYMBOL(crc7_be_syndrome_table);

/**
 * crc7 - update the CRC7 for the data buffer
 * @crc:     previous CRC7 value
 * @buffer:  data pointer
 * @len:     number of bytes in the buffer
 * Context: any
 *
 * Returns the updated CRC7 value.
 * The CRC7 is left-aligned in the byte (the lsbit is always 0), as that
 * makes the computation easier, and all callers want it in that form.
 *
 */
u8 crc7_be(u8 crc, const u8 *buffer, size_t len)
{
	while (len--)
		crc = crc7_be_byte(crc, *buffer++);
	return crc;
}
EXPORT_SYMBOL(crc7_be);

MODULE_DESCRIPTION("CRC7 calculations");
MODULE_LICENSE("GPL");
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