pflogd - packet filter logging daemon
pflogd [-C new-pflog-instance-name | -c pflog-instance-name] [-d delay] [-f filename] [-i interface] [-s snaplen] [expression]
PFLOGD(8) BSD System Manager's Manual PFLOGD(8)
NAME
pflogd -- packet filter logging daemon
SYNOPSIS
pflogd [-C new-pflog-instance-name | -c pflog-instance-name] [-d delay]
[-f filename] [-i interface] [-s snaplen] [expression]
DESCRIPTION
pflogd is a background daemon which reads packets logged by pf(4) to a
dedicated capture link interface (see dladm(1M) for details), normally
pflog0, and writes the packets to a logfile (normally
/var/log/firewall/pflog/pflog0.pkt) in libpcap format (see PCAP(3pcap)
for details). These logs can be reviewed later using the -r option of
tcpdump(8), hopefully offline in case there are bugs in the packet pars-
ing code of tcpdump(8).
pflogd closes and then re-opens the log file when it receives SIGHUP,
permitting convenient log rotation. SIGALRM causes pflogd to flush the
current logfile buffers to the disk, thus making the most recent logs
available. The buffers are also flushed every delay seconds.
If the log file contains data after a restart or a SIGHUP, new logs are
appended to the existing file. If the existing log file was created with
a different snaplen, pflogd temporarily uses the old snaplen to keep the
log file consistent.
pflogd tries to preserve the integrity of the log file against I/O
errors. Furthermore, integrity of an existing log file is verified
before appending. If there is an invalid log file or an I/O error, the
log file is moved out of the way and a new one is created. If a new file
cannot be created, logging is suspended until a SIGHUP or a SIGALRM is
received.
pflogd will also log the pcap statistics for the capture link interface
to syslog when a SIGUSR1 is received.
The options are as follows:
-C new-pflog-instance-name
Creates a new pflogd instance with the specified name. If addi-
tional options are used to specify configuration, it is stored
into the smf(7) repository. Default values are used for smf(7)
properties unless overriden by a command-line option. The excep-
tion is pflog/interface (set to equal the instance name) and
pflog/logfile (set to a file with name equal to the instance name
followed by the .pkt extension located inside the
/var/log/firewall/pflog/ directory) if the service instance name
forms a valid linkname. If the service instance name is not a
valid linkname, the values must be given explicitly.
-c pflog-instance-name
Shows/changes the configuration of the given pflogd instance in
smf(7) repository. Attributes specified by additional options are
placed into the smf(7) repository.
-d delay
Time in seconds to delay between automatic flushes of the file.
This may be specified with a value between 5 and 3600 seconds.
If not specified, the default is 60 seconds.
-f filename
Log output filename. When neither -C nor -c is used, the default
value pflog.pkt is used.
-i interface
Specifies the capture link interface to use. When neither -C nor
-c is used, the default value pflog0 is assumed.
-s snaplen
Analyze at most the first snaplen bytes of data from each packet
rather than the default of 160. The default of 160 is adequate
for IP, ICMP, TCP, and UDP headers but may truncate protocol
information for other protocols. Other file parsers may desire a
higher snaplen.
expression
Selects which packets will be dumped, using the regular language
of tcpdump(8). Tcpdump has been extended to be able to filter on
the pfloghdr structure defined in <net/if_pflog.h>. It can
restrict the output to packets logged on a specified interface, a
rule number, a reason, a direction, an IP family or an action.
ip Address family equals IPv4.
ip6 Address family equals IPv6.
ifname kue0 Interface name equals "kue0".
on kue0 Interface name equals "kue0".
ruleset authpf Ruleset name equals "authpf".
rulenum 10 Rule number equals 10.
reason match Reason equals match. Also accepts "bad-
offset", "fragment", "short", "normalize",
"memory", "bad-timestamp", "congestion",
"ip-option", "proto-cksum", "state-mis-
match", "state-insert", "state-limit",
"src-limit", and "synproxy".
action pass Action equals pass. Also accepts "block"
and "match".
inbound The direction was inbound.
outbound The direction was outbound.
SOLARIS
The pflogd daemon must be started as an smf(7) service with the following
FMRI:
svc:/network/firewall/pflog
Command line options described above are set via the following smf(7)
properties.
pflog/delay Automatic flush interval. The default value is 60.
Used as the argument for the -d option.
pflog/filter Packet filter expression in tcpdump(8) format. No
expression is defined by default.
pflog/interface The capture link name from which to read packets.
Used as the argument for the -i option.
pflog/logfile Path to the logfile (for security reasons, only paths
starting by the /var/log/firewall/ directory are
allowed. Used as the argument for the -f option.
pflog/snaplen An upper bound on how many bytes from each packet to
analyze. The default value is 160. Used as the
argument for the -s option.
The start method creates a (temporal) capture link the particular
instance is using.
The refresh method sends SIGHUP to pflogd owned by particular service
instance.
EXAMPLES
Log specific TCP packets to a different log file with a large snaplen
(useful with a "log all" rule to dump complete sessions):
# pflogd -s 1600 -f suspicious.log port 80 and host evilhost
Log from another capture link interface, excluding specific packets:
# pflogd -i pflog3 -f network3.log "not (tcp and port 23)"
Display binary logs:
# tcpdump -n -e -ttt -r /var/log/firewall/pflog/pflog3.pkt
Display the logs in real time (this does not interfere with the operation
of pflogd):
# tcpdump -n -e -ttt -i pflog0
Display the logs in real time of inbound packets that were blocked on the
wi0 interface:
# tcpdump -n -e -ttt -i pflog0 inbound and action block and on wi0
SECURITY
The pflogd daemon is a privilege-aware application which runs as the
``daemon'' user possessing PRIV_NET_OBSERVABILITY privilege that is
required for using bpf(7d) to read packets. See privileges(7) for
details. The service start method uses dladm(8) to create capture link
if it does not exist already.
To configure the pflogd service one has to obtain the
solaris.smf.value.network.firewall authorization. To manage the service
(disable/enable/refresh) one must have the
solaris.smf.manage.network.firewall authorization. Both authorizations
are granted through the Network Firewall Management profile. To create
new service instances, you need the solaris.smf.modify authorization.
ATTRIBUTES
See attributes(7) for descriptions of the following attributes:
+---------------+---------------------------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+---------------------------------+
|Availability | network/firewall/firewall-pflog |
+---------------+---------------------------------+
|Stability | Volatile |
+---------------+---------------------------------+
SEE ALSO
pcap(3), pf.conf(5), privileges(7), smf(7), tcpdump(8)
HISTORY
The pflogd command appeared in OpenBSD 3.0. The Solaris version is based
on pflogd found in OpenBSD 5.5.
AUTHORS
pflogd was written by Can Erkin Acar <canacar@openbsd.org>.
NOTES
Source code for open source software components in Oracle Solaris can be
found at https://www.oracle.com/downloads/opensource/solaris-source-code-
downloads.html.
This software was built from source available at https://github.com/ora-
cle/solaris-userland. The original community source was downloaded from
http://www.openbsd.org/cgi-bin/cvsweb/src/sbin/pflogd/.
Further information about this software can be found on the open source
community website at http://www.openbsd.org.
BSD January 21, 2014 BSD