Hello, This is a prototype suggestion. I mostly copied and pasted the code from net/dump.c into net.c and made some adjustments. There is no command line parsing involved yet, just the internals and small changes in net/tap.c and net/slirp.c do make the thing work.
In my tests, using tap as backend, e1000 as a guest device and running iperf from guest to host, the overhead of dumping the traffic caused a loss of around 30% of performance. I opened the dumped files in wireshark and they looked fine. When using slirp all requests were dumped fine too. Bugs/limitations: - I have no clue on how to deal with tap+vhost, is it necessary? - When using virtio-net, I'm not sure how to handle iovec when vnet_hdr=on - Create a function to add dump to a netdev on the fly, is it necessary? - Handle cleanups Miguel Di Ciurcio Filho (4): net/dump: Make pcap structures public net: Introduce NetClientDump and auxiliary functions net/tap: Suggested support for NetClientDump net/slirp: Suggested support for NetClientDump net.c | 90 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ net.h | 8 +++++ net/dump.c | 21 ------------- net/dump.h | 21 +++++++++++++ net/slirp.c | 3 ++ net/tap.c | 3 ++ qemu-common.h | 1 + 7 files changed, 126 insertions(+), 21 deletions(-)
