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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
test_memcat_p.c 
// SPDX-License-Identifier: GPL-2.0
/*
 * Test cases for memcat_p() in lib/memcat_p.c
 */
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/string.h>
#include <linux/slab.h>
#include <linux/module.h>

struct test_struct {
	int		num;
	unsigned int	magic;
};

#define MAGIC		0xf00ff00f
/* Size of each of the NULL-terminated input arrays */
#define INPUT_MAX	128
/* Expected number of non-NULL elements in the output array */
#define EXPECT		(INPUT_MAX * 2 - 2)

static int __init test_memcat_p_init(void)
{
	struct test_struct **in0, **in1, **out, **p;
	int err = -ENOMEM, i, r, total = 0;

	in0 = kcalloc(INPUT_MAX, sizeof(*in0), GFP_KERNEL);
	if (!in0)
		return err;

	in1 = kcalloc(INPUT_MAX, sizeof(*in1), GFP_KERNEL);
	if (!in1)
		goto err_free_in0;

	for (i = 0, r = 1; i < INPUT_MAX - 1; i++) {
		in0[i] = kmalloc(sizeof(**in0), GFP_KERNEL);
		if (!in0[i])
			goto err_free_elements;

		in1[i] = kmalloc(sizeof(**in1), GFP_KERNEL);
		if (!in1[i]) {
			kfree(in0[i]);
			goto err_free_elements;
		}

		/* lifted from test_sort.c */
		r = (r * 725861) % 6599;
		in0[i]->num = r;
		in1[i]->num = -r;
		in0[i]->magic = MAGIC;
		in1[i]->magic = MAGIC;
	}

	in0[i] = in1[i] = NULL;

	out = memcat_p(in0, in1);
	if (!out)
		goto err_free_all_elements;

	err = -EINVAL;
	for (i = 0, p = out; *p && (i < INPUT_MAX * 2 - 1); p++, i++) {
		total += (*p)->num;

		if ((*p)->magic != MAGIC) {
			pr_err("test failed: wrong magic at %d: %u\n", i,
			       (*p)->magic);
			goto err_free_out;
		}
	}

	if (total) {
		pr_err("test failed: expected zero total, got %d\n", total);
		goto err_free_out;
	}

	if (i != EXPECT) {
		pr_err("test failed: expected output size %d, got %d\n",
		       EXPECT, i);
		goto err_free_out;
	}

	for (i = 0; i < INPUT_MAX - 1; i++)
		if (out[i] != in0[i] || out[i + INPUT_MAX - 1] != in1[i]) {
			pr_err("test failed: wrong element order at %d\n", i);
			goto err_free_out;
		}

	err = 0;
	pr_info("test passed\n");

err_free_out:
	kfree(out);
err_free_all_elements:
	i = INPUT_MAX;
err_free_elements:
	for (i--; i >= 0; i--) {
		kfree(in1[i]);
		kfree(in0[i]);
	}

	kfree(in1);
err_free_in0:
	kfree(in0);

	return err;
}

static void __exit test_memcat_p_exit(void)
{
}

module_init(test_memcat_p_init);
module_exit(test_memcat_p_exit);

MODULE_LICENSE("GPL");
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