The packet-headers service provides a binary which collects packet headers for
all incoming TCP flows and saves each stream of packet captures into a
per-stream .pcap
file where the filename is the
UUID of the TCP flow. It only saves the
packet headers, and it supports (with a command-line flag) IP anonymity for
the saved addresses.
$ ./packet-headers -help 2>&1 | fmt | sed -e 's/\t/ /g'
Usage of ./packet-headers:
-anonymize.ip value
Valid values are "none" and "netblock". (default none)
-captureduration duration
Only save the first captureduration of each flow, to prevent
long-lived flows from spamming the hard drive. (default 30s)
-datadir string
The directory to which data is written (default ".")
-flowtimeout duration
Once there have been no packets for a flow for at least
flowtimeout, the flow can be assumed to be closed. (default 30s)
-interface value
The interface on which to capture traffic. May be repeated. If
unset, will capture on all available interfaces.
-maxheadersize int
The maximum size of packet headers allowed. A lower value allows
the pcap process to be less wasteful but risks more esoteric
IPv6 headers (which can theoretically be up to the full size
of the packet but in practice seem to be under 128) getting
truncated. (default 256)
-maxidleram value
How much idle RAM we should tolerate before we try and forcibly
return it to the OS. (default 3GB)
-prometheusx.listen-address string
(default ":9990")
-sigtermwait duration
How long should the daemon hang around before exiting after
receiving a SIGTERM. (default 1s)
-stream
Stream results to disk instead of buffering them in RAM.
-tcpinfo.eventsocket string
The filename of the unix-domain socket on which events are served.
-uuidwaitduration duration
Wait up to uuidwaitduration for each flow before either assigning
a UUID or discarding all future packets. This prevents buffering
unsaveable packets. (default 5s)
Running packet-headers
also requires running
tcp-info
and setting it up with an
eventsocket.
A good idea, but not required for v1.