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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
tag_ar9331.c 
// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2019 Pengutronix, Oleksij Rempel <kernel@pengutronix.de>
 */


#include <linux/bitfield.h>
#include <linux/etherdevice.h>

#include "dsa_priv.h"

#define AR9331_HDR_LEN			2
#define AR9331_HDR_VERSION		1

#define AR9331_HDR_VERSION_MASK		GENMASK(15, 14)
#define AR9331_HDR_PRIORITY_MASK	GENMASK(13, 12)
#define AR9331_HDR_TYPE_MASK		GENMASK(10, 8)
#define AR9331_HDR_BROADCAST		BIT(7)
#define AR9331_HDR_FROM_CPU		BIT(6)
/* AR9331_HDR_RESERVED - not used or may be version field.
 * According to the AR8216 doc it should 0b10. On AR9331 it is 0b11 on RX path
 * and should be set to 0b11 to make it work.
 */
#define AR9331_HDR_RESERVED_MASK	GENMASK(5, 4)
#define AR9331_HDR_PORT_NUM_MASK	GENMASK(3, 0)

static struct sk_buff *ar9331_tag_xmit(struct sk_buff *skb,
				       struct net_device *dev)
{
	struct dsa_port *dp = dsa_slave_to_port(dev);
	__le16 *phdr;
	u16 hdr;

	if (skb_cow_head(skb, AR9331_HDR_LEN) < 0)
		return NULL;

	phdr = skb_push(skb, AR9331_HDR_LEN);

	hdr = FIELD_PREP(AR9331_HDR_VERSION_MASK, AR9331_HDR_VERSION);
	hdr |= AR9331_HDR_FROM_CPU | dp->index;
	/* 0b10 for AR8216 and 0b11 for AR9331 */
	hdr |= AR9331_HDR_RESERVED_MASK;

	phdr[0] = cpu_to_le16(hdr);

	return skb;
}

static struct sk_buff *ar9331_tag_rcv(struct sk_buff *skb,
				      struct net_device *ndev,
				      struct packet_type *pt)
{
	u8 ver, port;
	u16 hdr;

	if (unlikely(!pskb_may_pull(skb, AR9331_HDR_LEN)))
		return NULL;

	hdr = le16_to_cpu(*(__le16 *)skb_mac_header(skb));

	ver = FIELD_GET(AR9331_HDR_VERSION_MASK, hdr);
	if (unlikely(ver != AR9331_HDR_VERSION)) {
		netdev_warn_once(ndev, "%s:%i wrong header version 0x%2x\n",
				 __func__, __LINE__, hdr);
		return NULL;
	}

	if (unlikely(hdr & AR9331_HDR_FROM_CPU)) {
		netdev_warn_once(ndev, "%s:%i packet should not be from cpu 0x%2x\n",
				 __func__, __LINE__, hdr);
		return NULL;
	}

	skb_pull_rcsum(skb, AR9331_HDR_LEN);

	/* Get source port information */
	port = FIELD_GET(AR9331_HDR_PORT_NUM_MASK, hdr);

	skb->dev = dsa_master_find_slave(ndev, 0, port);
	if (!skb->dev)
		return NULL;

	return skb;
}

static const struct dsa_device_ops ar9331_netdev_ops = {
	.name	= "ar9331",
	.proto	= DSA_TAG_PROTO_AR9331,
	.xmit	= ar9331_tag_xmit,
	.rcv	= ar9331_tag_rcv,
	.overhead = AR9331_HDR_LEN,
};

MODULE_LICENSE("GPL v2");
MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_AR9331);
module_dsa_tag_driver(ar9331_netdev_ops);
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