Currently, pcap_setdirection() is described in pcap.3 as follows:
pcap_setdirection() is used to limit the direction
that packets must be flowing in order to be captured.
The "direction" is not described, except in pcap.h.
Should the constants be mentioned in the manpage?
Also, the direction only seems to matter for live captures.
Jan
Index: pcap.3
===================================================================
RCS file: /cvs/src/lib/libpcap/pcap.3,v
retrieving revision 1.48
diff -u -p -r1.48 pcap.3
--- pcap.3 3 Jun 2018 10:45:15 -0000 1.48
+++ pcap.3 10 Dec 2018 07:12:53 -0000
@@ -535,6 +535,15 @@ datalink types.
.Fn pcap_setdirection
is used to limit the direction that packets must be flowing in order
to be captured.
+The direction is either
+.Dv PCAP_D_INOUT ,
+.Dv PCAP_D_IN
+or
+.Dv PCAP_D_OUT .
+Direction is only relevant to live captures.
+When reading from a dump file,
+.Fn pcap_setdirection
+has no effect .
.Pp
.Fn pcap_list_datalinks
returns an array of the supported datalink types for an opened live capture
