net: Strip virtio-net header when dumping

filter-dump specifiees Ethernet as PCAP LinkType, which does not expect
virtio-net header. Having virtio-net header in such PCAP file breaks
PCAP unconsumable. Unfortunately currently there is no LinkType for
virtio-net so for now strip virtio-net header to convert the output to
Ethernet.

Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/net/tap.c b/net/tap.c
index 7d7bc1dc5f..1bf085d422 100644
--- a/net/tap.c
+++ b/net/tap.c
@@ -255,6 +255,13 @@ static bool tap_has_vnet_hdr_len(NetClientState *nc, int len)
     return !!tap_probe_vnet_hdr_len(s->fd, len);
 }
 
+static int tap_get_vnet_hdr_len(NetClientState *nc)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+
+    return s->host_vnet_hdr_len;
+}
+
 static void tap_set_vnet_hdr_len(NetClientState *nc, int len)
 {
     TAPState *s = DO_UPCAST(TAPState, nc, nc);
@@ -268,6 +275,13 @@ static void tap_set_vnet_hdr_len(NetClientState *nc, int len)
     s->host_vnet_hdr_len = len;
 }
 
+static bool tap_get_using_vnet_hdr(NetClientState *nc)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+
+    return s->using_vnet_hdr;
+}
+
 static void tap_using_vnet_hdr(NetClientState *nc, bool using_vnet_hdr)
 {
     TAPState *s = DO_UPCAST(TAPState, nc, nc);
@@ -372,8 +386,10 @@ static NetClientInfo net_tap_info = {
     .has_ufo = tap_has_ufo,
     .has_vnet_hdr = tap_has_vnet_hdr,
     .has_vnet_hdr_len = tap_has_vnet_hdr_len,
+    .get_using_vnet_hdr = tap_get_using_vnet_hdr,
     .using_vnet_hdr = tap_using_vnet_hdr,
     .set_offload = tap_set_offload,
+    .get_vnet_hdr_len = tap_get_vnet_hdr_len,
     .set_vnet_hdr_len = tap_set_vnet_hdr_len,
     .set_vnet_le = tap_set_vnet_le,
     .set_vnet_be = tap_set_vnet_be,