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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
cfveil.c 
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) ST-Ericsson AB 2010
 * Author:	Sjur Brendeland
 */

#define pr_fmt(fmt) KBUILD_MODNAME ":%s(): " fmt, __func__

#include <linux/stddef.h>
#include <linux/slab.h>
#include <net/caif/caif_layer.h>
#include <net/caif/cfsrvl.h>
#include <net/caif/cfpkt.h>

#define VEI_PAYLOAD  0x00
#define VEI_CMD_BIT  0x80
#define VEI_FLOW_OFF 0x81
#define VEI_FLOW_ON  0x80
#define VEI_SET_PIN  0x82

#define container_obj(layr) container_of(layr, struct cfsrvl, layer)

static int cfvei_receive(struct cflayer *layr, struct cfpkt *pkt);
static int cfvei_transmit(struct cflayer *layr, struct cfpkt *pkt);

struct cflayer *cfvei_create(u8 channel_id, struct dev_info *dev_info)
{
	struct cfsrvl *vei = kzalloc(sizeof(struct cfsrvl), GFP_ATOMIC);
	if (!vei)
		return NULL;
	caif_assert(offsetof(struct cfsrvl, layer) == 0);
	cfsrvl_init(vei, channel_id, dev_info, true);
	vei->layer.receive = cfvei_receive;
	vei->layer.transmit = cfvei_transmit;
	snprintf(vei->layer.name, CAIF_LAYER_NAME_SZ, "vei%d", channel_id);
	return &vei->layer;
}

static int cfvei_receive(struct cflayer *layr, struct cfpkt *pkt)
{
	u8 cmd;
	int ret;
	caif_assert(layr->up != NULL);
	caif_assert(layr->receive != NULL);
	caif_assert(layr->ctrlcmd != NULL);


	if (cfpkt_extr_head(pkt, &cmd, 1) < 0) {
		pr_err("Packet is erroneous!\n");
		cfpkt_destroy(pkt);
		return -EPROTO;
	}
	switch (cmd) {
	case VEI_PAYLOAD:
		ret = layr->up->receive(layr->up, pkt);
		return ret;
	case VEI_FLOW_OFF:
		layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_OFF_IND, 0);
		cfpkt_destroy(pkt);
		return 0;
	case VEI_FLOW_ON:
		layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_ON_IND, 0);
		cfpkt_destroy(pkt);
		return 0;
	case VEI_SET_PIN:	/* SET RS232 PIN */
		cfpkt_destroy(pkt);
		return 0;
	default:		/* SET RS232 PIN */
		pr_warn("Unknown VEI control packet %d (0x%x)!\n", cmd, cmd);
		cfpkt_destroy(pkt);
		return -EPROTO;
	}
}

static int cfvei_transmit(struct cflayer *layr, struct cfpkt *pkt)
{
	u8 tmp = 0;
	struct caif_payload_info *info;
	int ret;
	struct cfsrvl *service = container_obj(layr);
	if (!cfsrvl_ready(service, &ret))
		goto err;
	caif_assert(layr->dn != NULL);
	caif_assert(layr->dn->transmit != NULL);

	if (cfpkt_add_head(pkt, &tmp, 1) < 0) {
		pr_err("Packet is erroneous!\n");
		ret = -EPROTO;
		goto err;
	}

	/* Add info-> for MUX-layer to route the packet out. */
	info = cfpkt_info(pkt);
	info->channel_id = service->layer.id;
	info->hdr_len = 1;
	info->dev_info = &service->dev_info;
	return layr->dn->transmit(layr->dn, pkt);
err:
	cfpkt_destroy(pkt);
	return ret;
}
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