andrewbasterfield / netmap-libpcap Goto Github PK

What steps will reproduce the problem?
1. Run tcpdump against an interface in netmap mode (against incoming traffic)
2. Look at the pcap in wireshark, timing resolution is in milliseconds
3. Run tcpdump against an interface in standard mode (against incoming traffic)
4. Look at the pcap in wireshark, timing resolution is in microseconds

What is the expected output? What do you see instead?
I'm running traffic to my DUT, which then processes the packets. I then save 
the egress traffic from DUT to pcap using traffic using netmap-libpcap. 
Netmap-libpcap has allowed to save packets at high speeds, but timestamping on 
the receiving side should also be timestamped at microsecond level

What version of the product are you using? On what operating system?
OS: Ubuntu 14.04 64bit (3.13.0-36-generic)
netmap git HEAD: 3ccdadad7d80bb1bc569d1f72ba3ece902350f65
netmap-libpcap git HEAD: 0890b993dae48767af172b693f2d664181dbe943
tcpdump: version 4.5.1

Please provide any additional information below.

I have attached three pcaps:

1. adapter_rx_timestamp1_netmap.pcap - captured via tcpdump -nei netmap:ethX
In this file, notice rx timestamp resolution is in micro-seconds

2. adapter_rx_timestamp3_nonetmap.pcap - captured via tcpdump -nei ethX
In this file, notice rx timestamp resolution is in milli-seconds