Commit 9125abe7 authored by Andrea Mayer's avatar Andrea Mayer Committed by Jakub Kicinski
Browse files

vrf: handle CONFIG_IPV6 not set for vrf_add_mac_header_if_unset() 



The vrf_add_mac_header_if_unset() is defined within a conditional
compilation block which depends on the CONFIG_IPV6 macro.
However, the vrf_add_mac_header_if_unset() needs to be called also by IPv4
related code and when the CONFIG_IPV6 is not set, this function is missing.
As a consequence, the build process stops reporting the error:

 ERROR: implicit declaration of function 'vrf_add_mac_header_if_unset'

The problem is solved by *only* moving functions
vrf_add_mac_header_if_unset() and vrf_prepare_mac_header() out of the
conditional block.

Reported-by: default avatarkernel test robot <lkp@intel.com>
Fixes: 04893908 ("vrf: add mac header for tunneled packets when sniffer is attached")
Signed-off-by: default avatarAndrea Mayer <andrea.mayer@uniroma2.it>
Reviewed-by: default avatarDavid Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20201208175210.8906-1-andrea.mayer@uniroma2.it


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent afae3cc2

drivers/net/vrf.c

+55 −55
Original line number Diff line number Diff line
@@ -1237,6 +1237,61 @@ static struct sk_buff *vrf_rcv_nfhook(u8 pf, unsigned int hook, 
	return skb;

}



static int vrf_prepare_mac_header(struct sk_buff *skb,

				  struct net_device *vrf_dev, u16 proto)

{

	struct ethhdr *eth;

	int err;



	/* in general, we do not know if there is enough space in the head of

	 * the packet for hosting the mac header.

	 */

	err = skb_cow_head(skb, LL_RESERVED_SPACE(vrf_dev));

	if (unlikely(err))

		/* no space in the skb head */

		return -ENOBUFS;



	__skb_push(skb, ETH_HLEN);

	eth = (struct ethhdr *)skb->data;



	skb_reset_mac_header(skb);



	/* we set the ethernet destination and the source addresses to the

	 * address of the VRF device.

	 */

	ether_addr_copy(eth->h_dest, vrf_dev->dev_addr);

	ether_addr_copy(eth->h_source, vrf_dev->dev_addr);

	eth->h_proto = htons(proto);



	/* the destination address of the Ethernet frame corresponds to the

	 * address set on the VRF interface; therefore, the packet is intended

	 * to be processed locally.

	 */

	skb->protocol = eth->h_proto;

	skb->pkt_type = PACKET_HOST;



	skb_postpush_rcsum(skb, skb->data, ETH_HLEN);



	skb_pull_inline(skb, ETH_HLEN);



	return 0;

}



/* prepare and add the mac header to the packet if it was not set previously.

 * In this way, packet sniffers such as tcpdump can parse the packet correctly.

 * If the mac header was already set, the original mac header is left

 * untouched and the function returns immediately.

 */

static int vrf_add_mac_header_if_unset(struct sk_buff *skb,

				       struct net_device *vrf_dev,

				       u16 proto)

{

	if (skb_mac_header_was_set(skb))

		return 0;



	return vrf_prepare_mac_header(skb, vrf_dev, proto);

}



#if IS_ENABLED(CONFIG_IPV6)

/* neighbor handling is done with actual device; do not want

 * to flip skb->dev for those ndisc packets. This really fails
@@ -1310,61 +1365,6 @@ static void vrf_ip6_input_dst(struct sk_buff *skb, struct net_device *vrf_dev, 
	skb_dst_set(skb, &rt6->dst);

}



static int vrf_prepare_mac_header(struct sk_buff *skb,

				  struct net_device *vrf_dev, u16 proto)

{

	struct ethhdr *eth;

	int err;



	/* in general, we do not know if there is enough space in the head of

	 * the packet for hosting the mac header.

	 */

	err = skb_cow_head(skb, LL_RESERVED_SPACE(vrf_dev));

	if (unlikely(err))

		/* no space in the skb head */

		return -ENOBUFS;



	__skb_push(skb, ETH_HLEN);

	eth = (struct ethhdr *)skb->data;



	skb_reset_mac_header(skb);



	/* we set the ethernet destination and the source addresses to the

	 * address of the VRF device.

	 */

	ether_addr_copy(eth->h_dest, vrf_dev->dev_addr);

	ether_addr_copy(eth->h_source, vrf_dev->dev_addr);

	eth->h_proto = htons(proto);



	/* the destination address of the Ethernet frame corresponds to the

	 * address set on the VRF interface; therefore, the packet is intended

	 * to be processed locally.

	 */

	skb->protocol = eth->h_proto;

	skb->pkt_type = PACKET_HOST;



	skb_postpush_rcsum(skb, skb->data, ETH_HLEN);



	skb_pull_inline(skb, ETH_HLEN);



	return 0;

}



/* prepare and add the mac header to the packet if it was not set previously.

 * In this way, packet sniffers such as tcpdump can parse the packet correctly.

 * If the mac header was already set, the original mac header is left

 * untouched and the function returns immediately.

 */

static int vrf_add_mac_header_if_unset(struct sk_buff *skb,

				       struct net_device *vrf_dev,

				       u16 proto)

{

	if (skb_mac_header_was_set(skb))

		return 0;



	return vrf_prepare_mac_header(skb, vrf_dev, proto);

}



static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev,

				   struct sk_buff *skb)

{

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