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authorEyal Birger <eyal.birger@gmail.com>2022-03-31 10:26:43 +0300
committerDavid S. Miller <davem@davemloft.net>2022-04-01 11:56:55 +0100
commit012d69fbfcc739f846766c1da56ef8b493b803b5 (patch)
tree46329b113ede4355b1fa5169135e44c2f6146059
parent9381fe8c849cfbe50245ac01fc077554f6eaa0e2 (diff)
vrf: fix packet sniffing for traffic originating from ip tunnels
in commit 048939088220 ("vrf: add mac header for tunneled packets when sniffer is attached") an Ethernet header was cooked for traffic originating from tunnel devices. However, the header is added based on whether the mac_header is unset and ignores cases where the device doesn't expose a mac header to upper layers, such as in ip tunnels like ipip and gre. Traffic originating from such devices still appears garbled when capturing on the vrf device. Fix by observing whether the original device exposes a header to upper layers, similar to the logic done in af_packet. In addition, skb->mac_len needs to be adjusted after adding the Ethernet header for the skb_push/pull() surrounding dev_queue_xmit_nit() to work on these packets. Fixes: 048939088220 ("vrf: add mac header for tunneled packets when sniffer is attached") Signed-off-by: Eyal Birger <eyal.birger@gmail.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/vrf.c15
1 files changed, 11 insertions, 4 deletions
diff --git a/drivers/net/vrf.c b/drivers/net/vrf.c
index 85e362461d71..cfc30ce4c6e1 100644
--- a/drivers/net/vrf.c
+++ b/drivers/net/vrf.c
@@ -1265,6 +1265,7 @@ static int vrf_prepare_mac_header(struct sk_buff *skb,
eth = (struct ethhdr *)skb->data;
skb_reset_mac_header(skb);
+ skb_reset_mac_len(skb);
/* we set the ethernet destination and the source addresses to the
* address of the VRF device.
@@ -1294,9 +1295,9 @@ static int vrf_prepare_mac_header(struct sk_buff *skb,
*/
static int vrf_add_mac_header_if_unset(struct sk_buff *skb,
struct net_device *vrf_dev,
- u16 proto)
+ u16 proto, struct net_device *orig_dev)
{
- if (skb_mac_header_was_set(skb))
+ if (skb_mac_header_was_set(skb) && dev_has_header(orig_dev))
return 0;
return vrf_prepare_mac_header(skb, vrf_dev, proto);
@@ -1402,6 +1403,8 @@ static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev,
/* if packet is NDISC then keep the ingress interface */
if (!is_ndisc) {
+ struct net_device *orig_dev = skb->dev;
+
vrf_rx_stats(vrf_dev, skb->len);
skb->dev = vrf_dev;
skb->skb_iif = vrf_dev->ifindex;
@@ -1410,7 +1413,8 @@ static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev,
int err;
err = vrf_add_mac_header_if_unset(skb, vrf_dev,
- ETH_P_IPV6);
+ ETH_P_IPV6,
+ orig_dev);
if (likely(!err)) {
skb_push(skb, skb->mac_len);
dev_queue_xmit_nit(skb, vrf_dev);
@@ -1440,6 +1444,8 @@ static struct sk_buff *vrf_ip6_rcv(struct net_device *vrf_dev,
static struct sk_buff *vrf_ip_rcv(struct net_device *vrf_dev,
struct sk_buff *skb)
{
+ struct net_device *orig_dev = skb->dev;
+
skb->dev = vrf_dev;
skb->skb_iif = vrf_dev->ifindex;
IPCB(skb)->flags |= IPSKB_L3SLAVE;
@@ -1460,7 +1466,8 @@ static struct sk_buff *vrf_ip_rcv(struct net_device *vrf_dev,
if (!list_empty(&vrf_dev->ptype_all)) {
int err;
- err = vrf_add_mac_header_if_unset(skb, vrf_dev, ETH_P_IP);
+ err = vrf_add_mac_header_if_unset(skb, vrf_dev, ETH_P_IP,
+ orig_dev);
if (likely(!err)) {
skb_push(skb, skb->mac_len);
dev_queue_xmit_nit(skb, vrf_dev);