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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
gen_crc64table.c 
// SPDX-License-Identifier: GPL-2.0
/*
 * Generate lookup table for the table-driven CRC64 calculation.
 *
 * gen_crc64table is executed in kernel build time and generates
 * lib/crc64table.h. This header is included by lib/crc64.c for
 * the table-driven CRC64 calculation.
 *
 * See lib/crc64.c for more information about which specification
 * and polynomial arithmetic that gen_crc64table.c follows to
 * generate the lookup table.
 *
 * Copyright 2018 SUSE Linux.
 *   Author: Coly Li <colyli@suse.de>
 */
#include <inttypes.h>
#include <stdio.h>

#define CRC64_ECMA182_POLY 0x42F0E1EBA9EA3693ULL

static uint64_t crc64_table[256] = {0};

static void generate_crc64_table(void)
{
	uint64_t i, j, c, crc;

	for (i = 0; i < 256; i++) {
		crc = 0;
		c = i << 56;

		for (j = 0; j < 8; j++) {
			if ((crc ^ c) & 0x8000000000000000ULL)
				crc = (crc << 1) ^ CRC64_ECMA182_POLY;
			else
				crc <<= 1;
			c <<= 1;
		}

		crc64_table[i] = crc;
	}
}

static void print_crc64_table(void)
{
	int i;

	printf("/* this file is generated - do not edit */\n\n");
	printf("#include <linux/types.h>\n");
	printf("#include <linux/cache.h>\n\n");
	printf("static const u64 ____cacheline_aligned crc64table[256] = {\n");
	for (i = 0; i < 256; i++) {
		printf("\t0x%016" PRIx64 "ULL", crc64_table[i]);
		if (i & 0x1)
			printf(",\n");
		else
			printf(", ");
	}
	printf("};\n");
}

int main(int argc, char *argv[])
{
	generate_crc64_table();
	print_crc64_table();
	return 0;
}
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