Skip to main content

Browse the archive

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
range.c 
// SPDX-License-Identifier: GPL-2.0
/*
 * Range add and subtract
 */
#include <linux/init.h>
#include <linux/minmax.h>
#include <linux/printk.h>
#include <linux/sort.h>
#include <linux/string.h>
#include <linux/range.h>

int add_range(struct range *range, int az, int nr_range, u64 start, u64 end)
{
	if (start >= end)
		return nr_range;

	/* Out of slots: */
	if (nr_range >= az)
		return nr_range;

	range[nr_range].start = start;
	range[nr_range].end = end;

	nr_range++;

	return nr_range;
}

int add_range_with_merge(struct range *range, int az, int nr_range,
		     u64 start, u64 end)
{
	int i;

	if (start >= end)
		return nr_range;

	/* get new start/end: */
	for (i = 0; i < nr_range; i++) {
		u64 common_start, common_end;

		if (!range[i].end)
			continue;

		common_start = max(range[i].start, start);
		common_end = min(range[i].end, end);
		if (common_start > common_end)
			continue;

		/* new start/end, will add it back at last */
		start = min(range[i].start, start);
		end = max(range[i].end, end);

		memmove(&range[i], &range[i + 1],
			(nr_range - (i + 1)) * sizeof(range[i]));
		range[nr_range - 1].start = 0;
		range[nr_range - 1].end   = 0;
		nr_range--;
		i--;
	}

	/* Need to add it: */
	return add_range(range, az, nr_range, start, end);
}

void subtract_range(struct range *range, int az, u64 start, u64 end)
{
	int i, j;

	if (start >= end)
		return;

	for (j = 0; j < az; j++) {
		if (!range[j].end)
			continue;

		if (start <= range[j].start && end >= range[j].end) {
			range[j].start = 0;
			range[j].end = 0;
			continue;
		}

		if (start <= range[j].start && end < range[j].end &&
		    range[j].start < end) {
			range[j].start = end;
			continue;
		}


		if (start > range[j].start && end >= range[j].end &&
		    range[j].end > start) {
			range[j].end = start;
			continue;
		}

		if (start > range[j].start && end < range[j].end) {
			/* Find the new spare: */
			for (i = 0; i < az; i++) {
				if (range[i].end == 0)
					break;
			}
			if (i < az) {
				range[i].end = range[j].end;
				range[i].start = end;
			} else {
				pr_err("%s: run out of slot in ranges\n",
					__func__);
			}
			range[j].end = start;
			continue;
		}
	}
}

static int cmp_range(const void *x1, const void *x2)
{
	const struct range *r1 = x1;
	const struct range *r2 = x2;

	if (r1->start < r2->start)
		return -1;
	if (r1->start > r2->start)
		return 1;
	return 0;
}

int clean_sort_range(struct range *range, int az)
{
	int i, j, k = az - 1, nr_range = az;

	for (i = 0; i < k; i++) {
		if (range[i].end)
			continue;
		for (j = k; j > i; j--) {
			if (range[j].end) {
				k = j;
				break;
			}
		}
		if (j == i)
			break;
		range[i].start = range[k].start;
		range[i].end   = range[k].end;
		range[k].start = 0;
		range[k].end   = 0;
		k--;
	}
	/* count it */
	for (i = 0; i < az; i++) {
		if (!range[i].end) {
			nr_range = i;
			break;
		}
	}

	/* sort them */
	sort(range, nr_range, sizeof(struct range), cmp_range, NULL);

	return nr_range;
}

void sort_range(struct range *range, int nr_range)
{
	/* sort them */
	sort(range, nr_range, sizeof(struct range), cmp_range, NULL);
}
back to top