PFLOG(4) BSD Kernel Interfaces Manual PFLOG(4)NAME
pflog — packet filter logging interface
SYNOPSIS
device pflog
DESCRIPTION
The pflog interface is a pseudo-device which makes visible all packets
logged by the packet filter, pf(4). Logged packets can easily be moni‐
tored in real time by invoking tcpdump(1) on the pflog interface, or
stored to disk using pflogd(8).
The pflog0 interface is created automatically at boot if both pf(4) and
pflogd(8) are enabled; further instances can be created using
ifconfig(8).
Each packet retrieved on this interface has a header associated with it
of length PFLOG_HDRLEN. This header documents the address family, inter‐
face name, rule number, reason, action, and direction of the packet that
was logged. This structure, defined in <net/pf/if_pflog.h> looks like
struct pfloghdr {
u_int8_t length;
sa_family_t af;
u_int8_t action;
u_int8_t reason;
char ifname[IFNAMSIZ];
char ruleset[PF_RULESET_NAME_SIZE];
u_int32_t rulenr;
u_int32_t subrulenr;
uid_t uid;
pid_t pid;
uid_t rule_uid;
pid_t rule_pid;
u_int8_t dir;
u_int8_t pad[3];
};
EXAMPLES
Create a pflog interface and monitor all packets logged on it:
# ifconfig pflog0 up
# tcpdump -n -e -ttt -i pflog0
SEE ALSOtcpdump(1), inet(4), inet6(4), netintro(4), pf(4), ifconfig(8), pflogd(8)HISTORY
The pflog device first appeared in OpenBSD 3.0 and was then integrated
into DragonFly 1.1 by Devon H. O'Dell and Simon Schubert.
BSD December 10, 2001 BSD
