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pcap-filter.manmisc.in
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.\" Copyright (c) 1987, 1988, 1989, 1990, 1991, 1992, 1994, 1995, 1996, 1997
.\" The Regents of the University of California. All rights reserved.
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that: (1) source code distributions
.\" retain the above copyright notice and this paragraph in its entirety, (2)
.\" distributions including binary code include the above copyright notice and
.\" this paragraph in its entirety in the documentation or other materials
.\" provided with the distribution, and (3) all advertising materials mentioning
.\" features or use of this software display the following acknowledgement:
.\" ``This product includes software developed by the University of California,
.\" Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
.\" the University nor the names of its contributors may be used to endorse
.\" or promote products derived from this software without specific prior
.\" written permission.
.\" THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
.\" WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
.\" MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
.\"
.TH PCAP-FILTER @MAN_MISC_INFO@ "4 January 2025"
.SH NAME
pcap-filter \- packet filter syntax
.br
.ad
.SH DESCRIPTION
.LP
.BR pcap_compile (3PCAP)
is used to compile a string into a filter program.
The resulting filter program can then be applied to
some stream of packets to determine which packets will be supplied to
.BR pcap_loop (3PCAP),
.BR pcap_dispatch (3PCAP),
.BR pcap_next (3PCAP),
or
.BR pcap_next_ex (3PCAP).
.LP
The \fIfilter expression\fP consists of one or more
.IR primitives .
Primitives usually consist of an
.I id
(name or number) preceded by one or more qualifiers.
There are three
different kinds of qualifier:
.IP \fItype\fP
.I type
qualifiers say what kind of thing the id name or number refers to.
Possible types are
.BR host ,
.BR net ,
.B port
and
.BR portrange .
E.g., `\fBhost\fP foo', `\fBnet\fP 128.3', `\fBport\fP 20', `\fBportrange\fP 6000-6008'.
If there is no type
qualifier,
.B host
is assumed.
.IP \fIdir\fP
.I dir
qualifiers specify a particular transfer direction to and/or from
.IR id .
Possible directions are
.BR src ,
.BR dst ,
.BR "src or dst" ,
.BR "src and dst" ,
.BR ra ,
.BR ta ,
.BR addr1 ,
.BR addr2 ,
.BR addr3 ,
and
.BR addr4 .
E.g., `\fBsrc\fP foo', `\fBdst net\fP 128.3', `\fBsrc or dst port\fP ftp-data'.
If
there is no dir qualifier, `\fBsrc or dst\fP' is assumed.
The
.BR ra ,
.BR ta ,
.BR addr1 ,
.BR addr2 ,
.BR addr3 ,
and
.B addr4
qualifiers are only valid for IEEE 802.11 Wireless LAN link layers.
.IP \fIproto\fP
.I proto
qualifiers restrict the match to a particular protocol.
Possible
protocols are:
.BR ether ,
.BR fddi ,
.BR tr ,
.BR wlan ,
.BR ip ,
.BR ip6 ,
.BR arp ,
.BR rarp ,
.BR decnet ,
.BR sctp ,
.B tcp
and
.BR udp .
E.g., `\fBether src\fP foo', `\fBarp net\fP 128.3', `\fBtcp port\fP 21',
`\fBudp portrange\fP 7000-7009', `\fBwlan addr2\fP 0:2:3:4:5:6'.
If there is no
.I proto
qualifier, all protocols consistent with the type are assumed.
E.g., `\fBsrc\fP foo' means `\fB(ip6 or ip or arp or rarp) src\fP foo',
`\fBnet\fP bar' means `\fB(ip or arp or rarp) net\fP bar' and
`\fBport\fP 53' means `\fB(tcp or udp or sctp) port\fP 53'
(note that these examples use invalid syntax to illustrate the principle).
.LP
[\fBfddi\fP is actually an alias for \fBether\fP; the parser treats them
identically as meaning ``the data link level used on the specified
network interface''. FDDI headers contain Ethernet-like source
and destination addresses, and often contain Ethernet-like packet
types, so you can filter on these FDDI fields just as with the
analogous Ethernet fields.
FDDI headers also contain other fields,
but you cannot name them explicitly in a filter expression.
.LP
Similarly, \fBtr\fP and \fBwlan\fP are aliases for \fBether\fP; the previous
paragraph's statements about FDDI headers also apply to Token Ring
and 802.11 wireless LAN headers. For 802.11 headers, the destination
address is the DA field and the source address is the SA field; the
BSSID, RA, and TA fields aren't tested.]
.LP
In addition to the above, there are some special `primitive' keywords
that don't follow the pattern:
.BR gateway ,
.BR broadcast ,
.BR less ,
.B greater
and arithmetic expressions.
All of these are described below.
.LP
More complex filter expressions are built up by using the words
.BR and ,
.B or
and
.B not
(or equivalently: `\fB&&\fP', `\fB||\fP' and `\fB!\fP' respectively)
to combine primitives.
E.g., `\fBhost\fP foo \fBand not port\fP ftp \fBand not port\fP ftp-data'.
To save typing, identical qualifier lists can be omitted.
E.g.,
`\fBtcp dst port\fP ftp \fBor\fP ftp-data \fBor\fP domain' is exactly the same as
`\fBtcp dst port\fP ftp \fBor tcp dst port\fP ftp-data \fBor tcp dst port\fP domain'.
.LP
Allowable primitives are:
.IP "\fBdst host \fIhostnameaddr\fR"
True if the IPv4/v6 destination field of the packet is \fIhostnameaddr\fP,
which may be either an address or a name.
.IP "\fBsrc host \fIhostnameaddr\fR"
True if the IPv4/v6 source field of the packet is \fIhostnameaddr\fP.
.IP "\fBhost \fIhostnameaddr\fP"
True if either the IPv4/v6 source or destination of the packet is \fIhostnameaddr\fP.
.IP
Any of the above host expressions can be prepended with the keywords,
\fBip\fP, \fBarp\fP, \fBrarp\fP, or \fBip6\fP as in:
.in +.5i
.nf
\fBip host \fIhostnameaddr\fR
.fi
.in -.5i
which is equivalent to:
.in +.5i
.nf
\fBether proto \\\fRip \fBand host \fIhostnameaddr\fR
.fi
.in -.5i
If \fIhostnameaddr\fR is a name with multiple IPv4/v6 addresses, each address will
be checked for a match.
.IP "\fBether dst \fIethernameaddr\fP"
True if the Ethernet destination address is \fIethernameaddr\fP.
\fIethernameaddr\fP
may be either a name from /etc/ethers or a numerical MAC address of the
form "xx:xx:xx:xx:xx:xx", "xx.xx.xx.xx.xx.xx", "xx-xx-xx-xx-xx-xx",
"xxxx.xxxx.xxxx" or "xxxxxxxxxxxx",
where each "x" is a hex digit (0-9, a-f, or A-F).
.IP "\fBether src \fIethernameaddr\fP"
True if the Ethernet source address is \fIethernameaddr\fP.
.IP "\fBether host \fIethernameaddr\fP"
True if either the Ethernet source or destination address is \fIethernameaddr\fP.
.IP "\fBgateway\fP \fIhost\fP"
True if the packet used \fIhost\fP as a gateway.
I.e., the Ethernet
source or destination address was \fIhost\fP but neither the IP source
nor the IP destination was \fIhost\fP.
\fIHost\fP must be a name and
must be found both by the machine's host-name-to-IP-address resolution
mechanisms (host name file, DNS, NIS, etc.) and by the machine's
host-name-to-Ethernet-address resolution mechanism (/etc/ethers, etc.).
(An equivalent expression is
.in +.5i
.nf
\fBether host \fIethernameaddr \fBand not host \fIhostnameaddr\fR
.fi
.in -.5i
which can be used with either names or numbers for \fIhostnameaddr / ethernameaddr\fP.)
This syntax does not work in IPv6-enabled configuration at this moment.
.IP "\fBdst net \fInetnameaddr\fR"
True if the IPv4/v6 destination address of the packet has a network
number of \fInetnameaddr\fP.
\fINet\fP may be either a name from the networks database
(/etc/networks, etc.) or a network number.
An IPv4 network number can be written as a dotted quad (e.g., 192.168.1.0),
dotted triple (e.g., 192.168.1), dotted pair (e.g, 172.16), or single
number (e.g., 10); the netmask is 255.255.255.255 for a dotted quad
(which means that it's really a host match), 255.255.255.0 for a dotted
triple, 255.255.0.0 for a dotted pair, or 255.0.0.0 for a single number.
An IPv6 network number must be written out fully; the netmask is
ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff, so IPv6 "network" matches are really always
host matches, and a network match requires a netmask length.
.IP "\fBsrc net \fInetnameaddr\fR"
True if the IPv4/v6 source address of the packet has a network
number of \fInetnameaddr\fP.
.IP "\fBnet \fInetnameaddr\fR"
True if either the IPv4/v6 source or destination address of the packet has a network
number of \fInetnameaddr\fP.
.IP "\fBnet \fInetaddr\fR \fBmask \fInetmask\fR"
True if the IPv4 address matches \fInetaddr\fR with the specific \fInetmask\fR.
May be qualified with \fBsrc\fR or \fBdst\fR.
Note that this syntax is not valid for IPv6 \fInetaddr\fR.
.IP "\fBnet \fInetaddr\fR/\fIlen\fR"
True if the IPv4/v6 address matches \fInetaddr\fR with a netmask \fIlen\fR
bits wide.
May be qualified with \fBsrc\fR or \fBdst\fR.
.IP "\fBdst port \fIportnamenum\fR"
True if the packet is IPv4/v6 TCP, UDP or SCTP and has a
destination port value of \fIportnamenum\fP.
The \fIportnamenum\fP can be a number or a name used in /etc/services (see
.BR tcp (4P)
and
.BR udp (4P)).
If a name is used, both the port
number and protocol are checked.
If a number or ambiguous name is used,
only the port number is checked (e.g., `\fBdst port\fR 513' will print both
tcp/login traffic and udp/who traffic, and `\fBport\fR domain' will print
both tcp/domain and udp/domain traffic).
.IP "\fBsrc port \fIportnamenum\fR"
True if the packet has a source port value of \fIportnamenum\fP.
.IP "\fBport \fIportnamenum\fR"
True if either the source or destination port of the packet is \fIportnamenum\fP.
.IP "\fBdst portrange \fIportnamenum1-portnamenum2\fR"
True if the packet is IPv4/v6 TCP, UDP or SCTP and has a
destination port value between \fIportnamenum1\fP and \fIportnamenum2\fP (both inclusive).
.I portnamenum1
and
.I portnamenum2
are interpreted in the same fashion as the
.I portnamenum
parameter for
.BR port .
.IP "\fBsrc portrange \fIportnamenum1-portnamenum2\fR"
True if the packet has a source port value between \fIportnamenum1\fP and
\fIportnamenum2\fP (both inclusive).
.IP "\fBportrange \fIportnamenum1-portnamenum2\fR"
True if either the source or destination port of the packet is between
\fIportnamenum1\fP and \fIportnamenum2\fP (both inclusive).
.IP
Any of the above port or port range expressions can be prepended with
the keywords, \fBtcp\fP, \fBudp\fP or \fBsctp\fP, as in:
.in +.5i
.nf
\fBtcp src port \fIportnamenum\fR
.fi
.in -.5i
which matches only TCP packets whose source port is \fIportnamenum\fP.
.IP "\fBless \fIlength\fR"
True if the packet has a length less than or equal to \fIlength\fP.
This is equivalent to:
.in +.5i
.nf
\fBlen <= \fIlength\fP
.fi
.in -.5i
.IP "\fBgreater \fIlength\fR"
True if the packet has a length greater than or equal to \fIlength\fP.
This is equivalent to:
.in +.5i
.nf
\fBlen >= \fIlength\fP
.fi
.in -.5i
.IP "\fBip proto \fIprotocol\fR"
True if the packet is an IPv4 packet (see
.BR ip (4P))
of protocol type \fIprotocol\fP.
\fIProtocol\fP can be a number or one of the names recognized by
.BR getprotobyname (3),
for example:
.BR ah ,
.BR esp ,
.B eigrp
(only in Linux with glibc, FreeBSD, NetBSD, DragonFly BSD, and macOS),
.BR icmp ,
.BR igmp ,
.B igrp
(only in Haiku and OpenBSD),
.BR pim ,
.BR sctp ,
.BR tcp ,
.B udp
or
.BR vrrp .
Note that most of these example identifiers
are also keywords and must be escaped via backslash (\\).
Note that this primitive does not chase the protocol header chain.
.IP
Typically
.BR getprotobyname (3)
parses the
.IR \%/etc/protocols
file to translate protocol names to numbers, and the
.B "getent protocols"
command lists the protocols recognised by the function. This is not entirely
so in AIX (which does not have the command), Haiku (which has the file at
.IR \%/system/data/network/protocols
and does not have the command), on Linux with musl libc (which hard-codes the
list of protocols) and on hosts that use a network database to resolve
protocol names to numbers (see
.BR nsswitch.conf (5)).
If a protocol name fails to translate to a number, this version of libpcap
will treat the filter expression as invalid.
.IP "\fBcarp\fR, \fBvrrp\fR"
Abbreviations for:
.in +.5i
.nf
\fBip proto\fR 112
.fi
.in -.5i
.IP "\fBicmp\fR"
Abbreviation for:
.in +.5i
.nf
\fBip proto\fR 1
.fi
.in -.5i
.IP "\fBigmp\fR"
Abbreviation for:
.in +.5i
.nf
\fBip proto\fR 2
.fi
.in -.5i
.IP "\fBigrp\fR"
Abbreviation for:
.in +.5i
.nf
\fBip proto\fR 9
.fi
.in -.5i
.IP "\fBip6 proto \fIprotocol\fR"
True if the packet is an IPv6 packet of protocol type \fIprotocol\fP.
(See `\fBip proto\fP' above for the meaning of \fIprotocol\fR.)
Note that the IPv6 variant of ICMP uses a different protocol number, named
.B \%ipv6-icmp
in AIX, FreeBSD, illumos, Haiku, GNU/Hurd, Linux, macOS, NetBSD, OpenBSD,
Solaris and Windows.
Note that this primitive does not chase the protocol header chain.
.IP "\fBicmp6\fR"
Abbreviation for:
.in +.5i
.nf
\fBip6 proto\fR 58
.fi
.in -.5i
.IP "\fBproto \fIprotocol\fR"
True if the packet is an IPv4 or IPv6 packet of protocol type
\fIprotocol\fP. (See `\fBip proto\fP' above for the meaning of
\fIprotocol\fP.) Note that this primitive does not chase the protocol
header chain.
.IP "\fBah\fR, \fBesp\fR, \fBpim\fR, \fBsctp\fR, \fBtcp\fR, \fBudp\fR"
Abbreviations for:
.in +.5i
.nf
\fBproto \\\fIprotocol\fR
.fi
.in -.5i
where \fIprotocol\fR is one of the above protocols.
.IP "\fBip6 protochain \fIprotocol\fR"
True if the packet is IPv6 packet,
and contains protocol header with type \fIprotocol\fR
in its protocol header chain.
(See `\fBip proto\fP' above for the meaning of \fIprotocol\fP.)
For example,
.in +.5i
.nf
\fBip6 protochain\fR 6
.fi
.in -.5i
matches any IPv6 packet with TCP protocol header in the protocol header chain.
The packet may contain, for example,
authentication header, routing header, or hop-by-hop option header,
between IPv6 header and TCP header.
The BPF code emitted by this primitive is complex and
cannot be optimized by the BPF optimizer code, and is not supported by
filter engines in the kernel, so this can be somewhat slow, and may
cause more packets to be dropped.
.IP "\fBip protochain \fIprotocol\fR"
Equivalent to \fBip6 protochain \fIprotocol\fR, but this is for IPv4.
(See `\fBip proto\fP' above for the meaning of \fIprotocol\fP.)
.IP "\fBprotochain \fIprotocol\fR"
True if the packet is an IPv4 or IPv6 packet of protocol type
\fIprotocol\fP. (See `\fBip proto\fP' above for the meaning of
\fIprotocol\fP.) Note that this primitive chases the protocol
header chain.
.IP "\fBether broadcast\fR"
True if the packet is an Ethernet broadcast packet.
The \fBether\fP
keyword is optional.
.IP "\fBip broadcast\fR"
True if the packet is an IPv4 broadcast packet.
It checks for both the all-zeroes and all-ones broadcast conventions,
and looks up the subnet mask on the interface on which the capture is
being done.
.IP
If the subnet mask of the interface on which the capture is being done
is not available, either because the interface on which capture is being
done has no netmask or because the capture is being done on the Linux
"any" interface, which can capture on more than one interface, this
check will not work correctly.
.IP "\fBether multicast\fR"
True if the packet is an Ethernet multicast packet.
The \fBether\fP
keyword is optional.
This is shorthand for `\fBether[\fP0\fB] & \fP1\fB != \fP0'.
.IP "\fBip multicast\fR"
True if the packet is an IPv4 multicast packet.
.IP "\fBip6 multicast\fR"
True if the packet is an IPv6 multicast packet.
.IP "\fBether proto \fIprotocol\fR"
True if the packet is of ether type \fIprotocol\fR.
\fIProtocol\fP can be a number or one of the names
\fBaarp\fP, \fBarp\fP, \fBatalk\fP, \fBdecnet\fP, \fBip\fP, \fBip6\fP,
\fBipx\fP, \fBiso\fP, \fBlat\fP, \fBloopback\fP, \fBmopdl\fP, \fBmoprc\fP, \fBnetbeui\fP,
\fBrarp\fP, \fBsca\fP or \fBstp\fP.
Note these identifiers (except \fBloopback\fP) are also keywords
and must be escaped via backslash (\\).
.IP
[In the case of FDDI (e.g., `\fBfddi proto \\arp\fR'), Token Ring
(e.g., `\fBtr proto \\arp\fR'), and IEEE 802.11 wireless LANs (e.g.,
`\fBwlan proto \\arp\fR'), for most of those protocols, the
protocol identification comes from the 802.2 Logical Link Control (LLC)
header, which is usually layered on top of the FDDI, Token Ring, or
802.11 header.
.IP
When filtering for most protocol identifiers on FDDI, Token Ring, or
802.11, the filter checks only the protocol ID field of an LLC header
in so-called SNAP format with an Organizational Unit Identifier (OUI) of
0x000000, for encapsulated Ethernet; it doesn't check whether the packet
is in SNAP format with an OUI of 0x000000.
The exceptions are:
.RS
.TP
\fBiso\fP
the filter checks the DSAP (Destination Service Access Point) and
SSAP (Source Service Access Point) fields of the LLC header;
.TP
\fBstp\fP and \fBnetbeui\fP
the filter checks the DSAP of the LLC header;
.TP
\fBatalk\fP
the filter checks for a SNAP-format packet with an OUI of 0x080007
and the AppleTalk etype.
.RE
.IP
In the case of Ethernet, the filter checks the Ethernet type field
for most of those protocols. The exceptions are:
.RS
.TP
\fBiso\fP, \fBstp\fP, and \fBnetbeui\fP
the filter checks for an 802.3 frame and then checks the LLC header as
it does for FDDI, Token Ring, and 802.11;
.TP
\fBatalk\fP
the filter checks both for the AppleTalk etype in an Ethernet frame and
for a SNAP-format packet as it does for FDDI, Token Ring, and 802.11;
.TP
\fBaarp\fP
the filter checks for the AppleTalk ARP etype in either an Ethernet
frame or an 802.2 SNAP frame with an OUI of 0x000000;
.TP
\fBipx\fP
the filter checks for the IPX etype in an Ethernet frame, the IPX
DSAP in the LLC header, the 802.3-with-no-LLC-header encapsulation of
IPX, and the IPX etype in a SNAP frame.
.RE
.IP "\fBip\fR, \fBip6\fR, \fBarp\fR, \fBrarp\fR, \fBatalk\fR, \fBaarp\fR, \fBdecnet\fR, \fBiso\fR, \fBstp\fR, \fBipx\fR, \fBnetbeui\fP"
Abbreviations for:
.in +.5i
.nf
\fBether proto \\\fIprotocol\fR
.fi
.in -.5i
where \fIprotocol\fR is one of the above protocols.
.IP "\fBlat\fR, \fBmopdl\fR, \fBmoprc\fR, \fBsca\fR"
Abbreviations for:
.in +.5i
.nf
\fBether proto \\\fIprotocol\fR
.fi
.in -.5i
where \fIprotocol\fR is one of the above protocols, all of which originated
at DEC, but are not the same as DECnet. Namely,
.B lat
is Local Area Transport (LAT),
.B mopdl
is DNA Dump/Load (MOP),
.B moprc
is DNA Remote Console (MOP) and
.B sca
is System Communication Architecture (SCA).
.IP "\fBdecnet src \fIdecnetaddr\fR"
True if the DECnet source address is
.IR decnetaddr ,
which is an address of the form
.B AREANUMBER.NODENUMBER
(for example, "10.123"), where the area number can be between 0 and 63
and the node number can be between 0 and 1023 and both numbers always use
decimal base.
.IP "\fBdecnet dst \fIdecnetaddr\fR"
True if the DECnet destination address is
.IR decnetaddr .
.IP "\fBdecnet host \fIdecnetaddr\fR"
True if either the DECnet source or destination address is
.IR decnetaddr .
.IP \fBllc\fP
True if the packet has an 802.2 LLC header. This includes:
.IP
Ethernet packets with a length field rather than a type field that
aren't raw NetWare-over-802.3 packets;
.IP
IEEE 802.11 data packets;
.IP
Token Ring packets (no check is done for LLC frames);
.IP
FDDI packets (no check is done for LLC frames);
.IP
LLC-encapsulated ATM packets, for SunATM on Solaris.
.IP "\fBllc\fP \fItype\fR"
True if the packet has an 802.2 LLC header and has the specified
.IR type .
.I type
can be one of:
.RS
.TP
\fBi\fR
Information (I) PDUs
.TP
\fBs\fR
Supervisory (S) PDUs
.TP
\fBu\fR
Unnumbered (U) PDUs
.TP
\fBrr\fR
Receiver Ready (RR) S PDUs
.TP
\fBrnr\fR
Receiver Not Ready (RNR) S PDUs
.TP
\fBrej\fR
Reject (REJ) S PDUs
.TP
\fBui\fR
Unnumbered Information (UI) U PDUs
.TP
\fBua\fR
Unnumbered Acknowledgment (UA) U PDUs
.TP
\fBdisc\fR
Disconnect (DISC) U PDUs
.TP
\fBdm\fR
Disconnected Mode (DM) U PDUs
.TP
\fBsabme\fR
Set Asynchronous Balanced Mode Extended (SABME) U PDUs
.TP
\fBtest\fR
Test (TEST) U PDUs
.TP
\fBxid\fR
Exchange Identification (XID) U PDUs
.TP
\fBfrmr\fR
Frame Reject (FRMR) U PDUs
.RE
.IP \fBinbound\fP
Packet was received by the host performing the capture rather than being
sent by that host. This is only supported for certain link-layer types,
such as SLIP and the ``cooked'' Linux capture mode
used for the ``any'' device and for some other device types.
.IP \fBoutbound\fP
Packet was sent by the host performing the capture rather than being
received by that host. This is only supported for certain link-layer types,
such as SLIP and the ``cooked'' Linux capture mode
used for the ``any'' device and for some other device types.
.IP "\fBifindex \fIinterface_index\fR"
True if the packet was logged via the specified interface (applies only to
packets logged by the Linux "any" cooked v2 interface).
.IP "\fBifname \fIinterface\fR"
True if the packet was logged as coming from the specified interface (applies
only to packets logged by OpenBSD's or FreeBSD's
.BR pf (4)).
.IP "\fBon \fIinterface\fR"
Synonymous with the
.B ifname
modifier.
.IP "\fBrnr \fInum\fR"
True if the packet was logged as matching the specified PF rule number
(applies only to packets logged by OpenBSD's or FreeBSD's
.BR pf (4)).
.IP "\fBrulenum \fInum\fR"
Synonymous with the
.B rnr
modifier.
.IP "\fBreason \fIcode\fR"
True if the packet was logged with the specified PF reason code. The known
codes are:
.BR \%match ,
.BR \%bad-offset ,
.BR \%fragment ,
.BR \%short ,
.BR \%normalize ,
and
.B memory
(applies only to packets logged by OpenBSD's or FreeBSD's
.BR pf (4)).
.IP "\fBrset \fIname\fR"
True if the packet was logged as matching the specified PF ruleset
name of an anchored ruleset (applies only to packets logged by OpenBSD's
or FreeBSD's
.BR pf (4)).
.IP "\fBruleset \fIname\fR"
Synonymous with the
.B rset
modifier.
.IP "\fBsrnr \fInum\fR"
True if the packet was logged as matching the specified PF rule number
of an anchored ruleset (applies only to packets logged by OpenBSD's or
FreeBSD's
.BR pf (4)).
.IP "\fBsubrulenum \fInum\fR"
Synonymous with the
.B srnr
modifier.
.IP "\fBaction \fIact\fR"
True if PF took the specified action when the packet was logged. Known actions
are:
.B pass
and
.B block
and, with later versions of
.BR pf (4),
.BR nat ,
.BR rdr ,
.B binat
and
.B scrub
(applies only to packets logged by OpenBSD's or FreeBSD's
.BR pf (4)).
.IP "\fBwlan ra \fIehost\fR"
True if the IEEE 802.11 RA is
.IR ehost .
The RA field is used in all frames except for management frames.
.IP "\fBwlan ta \fIehost\fR"
True if the IEEE 802.11 TA is
.IR ehost .
The TA field is used in all frames except for management frames and
CTS (Clear To Send) and ACK (Acknowledgment) control frames.
.IP "\fBwlan addr1 \fIehost\fR"
True if the first IEEE 802.11 address is
.IR ehost .
.IP "\fBwlan addr2 \fIehost\fR"
True if the second IEEE 802.11 address, if present, is
.IR ehost .
The second address field is used in all frames except for CTS (Clear To
Send) and ACK (Acknowledgment) control frames.
.IP "\fBwlan addr3 \fIehost\fR"
True if the third IEEE 802.11 address, if present, is
.IR ehost .
The third address field is used in management and data frames, but not
in control frames.
.IP "\fBwlan addr4 \fIehost\fR"
True if the fourth IEEE 802.11 address, if present, is
.IR ehost .
The fourth address field is only used for
WDS (Wireless Distribution System) frames.
.IP "\fBtype \fIwlan_type\fR"
True if the IEEE 802.11 frame type matches the specified \fIwlan_type\fR.
Valid \fIwlan_type\fRs are:
\fBmgt\fP,
\fBctl\fP
and \fBdata\fP.
.IP "\fBtype \fIwlan_type \fBsubtype \fIwlan_subtype\fR"
True if the IEEE 802.11 frame type matches the specified \fIwlan_type\fR
and frame subtype matches the specified \fIwlan_subtype\fR.
.IP
If the specified \fIwlan_type\fR is \fBmgt\fP,
then valid \fIwlan_subtype\fRs are:
\fBassoc-req\fP,
\fBassoc-resp\fP,
\fBreassoc-req\fP,
\fBreassoc-resp\fP,
\fBprobe-req\fP,
\fBprobe-resp\fP,
\fBbeacon\fP,
\fBatim\fP,
\fBdisassoc\fP,
\fBauth\fP and
\fBdeauth\fP.
.IP
If the specified \fIwlan_type\fR is \fBctl\fP,
then valid \fIwlan_subtype\fRs are:
\fBbar\fP,
\fBba\fP,
\fBps-poll\fP,
\fBrts\fP,
\fBcts\fP,
\fBack\fP,
\fBcf-end\fP and
\fBcf-end-ack\fP.
.IP
If the specified \fIwlan_type\fR is \fBdata\fP,
then valid \fIwlan_subtype\fRs are:
.BR \%data ,
.BR \%data-cf-ack ,
.BR \%data-cf-poll ,
.BR \%data-cf-ack-poll ,
.BR \%null ,
.BR \%cf-ack ,
.BR \%cf-poll ,
.BR \%cf-ack-poll ,
.BR \%qos-data ,
.BR \%qos-data-cf-ack ,
.BR \%qos-data-cf-poll ,
.BR \%qos-data-cf-ack-poll ,
.BR \%qos ,
.B \%qos-cf-poll
and
.BR \%qos-cf-ack-poll .
.IP "\fBsubtype \fIwlan_subtype\fR"
True if the IEEE 802.11 frame subtype matches the specified \fIwlan_subtype\fR
and frame has the type to which the specified \fIwlan_subtype\fR belongs.
.IP "\fBdir \fIdirection\fR"
True if the IEEE 802.11 frame direction matches the specified
.IR direction .
Valid directions are:
.BR nods ,
.BR tods ,
.BR fromds ,
.BR dstods ,
or a numeric value.
.IP "\fBvlan \fI[vlan_id]\fR"
True if the packet is an IEEE 802.1Q VLAN packet.
If the optional \fIvlan_id\fR is specified, only true if the packet has the specified
\fIvlan_id\fR.
Note that the first \fBvlan\fR keyword encountered in an expression
changes the decoding offsets for the remainder of the expression on
the assumption that the packet is a VLAN packet. The `\fBvlan
\fI[vlan_id]\fR` keyword may be used more than once, to filter on VLAN
hierarchies. Each use of that keyword increments the filter offsets
by 4.
.IP
For example:
.in +.5i
.nf
\fBvlan\fP 100 \fB&& vlan\fR 200
.fi
.in -.5i
filters on VLAN 200 encapsulated within VLAN 100, and
.in +.5i
.nf
\fBvlan && vlan \fP300 \fB&& ip\fR
.fi
.in -.5i
filters IPv4 protocol encapsulated in VLAN 300 encapsulated within any
higher order VLAN.
.IP "\fBmpls \fI[label_num]\fR"
True if the packet is an MPLS packet.
If the optional \fIlabel_num\fR is specified, only true if the packet has the specified
\fIlabel_num\fR.
Note that the first \fBmpls\fR keyword encountered in an expression
changes the decoding offsets for the remainder of the expression on
the assumption that the packet is a MPLS-encapsulated IP packet. The
`\fBmpls \fI[label_num]\fR` keyword may be used more than once, to
filter on MPLS hierarchies. Each use of that keyword increments the
filter offsets by 4.
.IP
For example:
.in +.5i
.nf
\fBmpls\fP 100000 \fB&& mpls\fR 1024
.fi
.in -.5i
filters packets with an outer label of 100000 and an inner label of
1024, and
.in +.5i
.nf
\fBmpls && mpls\fP 1024 \fB&& host\fR 192.9.200.1
.fi
.in -.5i
filters packets to or from 192.9.200.1 with an inner label of 1024 and
any outer label.
.IP \fBpppoed\fP
True if the packet is a PPP-over-Ethernet Discovery packet (Ethernet
type 0x8863).
.IP "\fBpppoes \fI[session_id]\fR"
True if the packet is a PPP-over-Ethernet Session packet (Ethernet
type 0x8864).
If the optional \fIsession_id\fR is specified, only true if the packet has the specified
\fIsession_id\fR.
Note that the first \fBpppoes\fR keyword encountered in an expression
changes the decoding offsets for the remainder of the expression on
the assumption that the packet is a PPPoE session packet.
.IP
For example:
.in +.5i
.nf
\fBpppoes\fP 0x27 \fB&& ip\fR
.fi
.in -.5i
filters IPv4 protocol encapsulated in PPPoE session id 0x27.
.IP "\fBgeneve \fI[vni]\fR"
True if the packet is a Geneve packet (UDP port 6081). If the optional \fIvni\fR
is specified, only true if the packet has the specified \fIvni\fR.
Note that when the \fBgeneve\fR keyword is encountered in
an expression, it changes the decoding offsets for the remainder of
the expression on the assumption that the packet is a Geneve packet.
.IP
For example:
.in +.5i
.nf
\fBgeneve\fP 0xb \fB&& ip\fR
.fi
.in -.5i
filters IPv4 protocol encapsulated in Geneve with VNI 0xb. This will
match both IPv4 directly encapsulated in Geneve as well as IPv4 contained
inside an Ethernet frame.
.IP "\fBvxlan \fI[vni]\fR"
True if the packet is a VXLAN packet (UDP port 4789). If the optional
\fIvni\fR is specified, only true if the packet has the specified
\fIvni\fR. Note that when the \fBvxlan\fR keyword is encountered in
an expression, it changes the decoding offsets for the remainder of
the expression on the assumption that the packet is a VXLAN packet.
.IP
For example:
.in +.5i
.nf
\fBvxlan\fP 0x7 \fB&& ip6 \fR
.fi
.in -.5i
filters IPv6 protocol encapsulated in VXLAN with VNI 0x7.
.IP "\fBiso proto \fIprotocol\fR"
True if the packet is an OSI packet of protocol type \fIprotocol\fP.
\fIProtocol\fP can be a number or one of the names
\fBclnp\fP, \fBesis\fP, or \fBisis\fP.
.IP "\fBclnp\fR, \fBesis\fR, \fBisis\fR"
Abbreviations for:
.in +.5i
.nf
\fBiso proto \\\fIprotocol\fR
.fi
.in -.5i
where \fIprotocol\fR is one of the above protocols.
.IP "\fBl1\fR, \fBl2\fR, \fBiih\fR, \fBlsp\fR, \fBsnp\fR, \fBcsnp\fR, \fBpsnp\fR"
Abbreviations for IS-IS PDU types.
.IP "\fBvpi\fP \fIn\fR"
True if the packet is an ATM packet, for SunATM on Solaris, with a
virtual path identifier of
.IR n .
.IP "\fBvci\fP \fIn\fR"
True if the packet is an ATM packet, for SunATM on Solaris, with a
virtual channel identifier of
.IR n .
.IP \fBlane\fP
True if the packet is an ATM packet, for SunATM on Solaris, and is
an ATM LANE packet.
Note that the first \fBlane\fR keyword encountered in an expression
changes the tests done in the remainder of the expression
on the assumption that the packet is either a LANE emulated Ethernet
packet or a LANE LE Control packet. If \fBlane\fR isn't specified, the
tests are done under the assumption that the packet is an
LLC-encapsulated packet.
.IP \fBoamf4sc\fP
True if the packet is an ATM packet, for SunATM on Solaris, and is
a segment OAM F4 flow cell (VPI=0 & VCI=3).
.IP \fBoamf4ec\fP
True if the packet is an ATM packet, for SunATM on Solaris, and is
an end-to-end OAM F4 flow cell (VPI=0 & VCI=4).
.IP \fBoamf4\fP
True if the packet is an ATM packet, for SunATM on Solaris, and is
a segment or end-to-end OAM F4 flow cell (VPI=0 & (VCI=3 | VCI=4)).
.IP \fBoam\fP
True if the packet is an ATM packet, for SunATM on Solaris, and is
a segment or end-to-end OAM F4 flow cell (VPI=0 & (VCI=3 | VCI=4)).
.IP \fBmetac\fP
True if the packet is an ATM packet, for SunATM on Solaris, and is
on a meta signaling circuit (VPI=0 & VCI=1).
.IP \fBbcc\fP
True if the packet is an ATM packet, for SunATM on Solaris, and is
on a broadcast signaling circuit (VPI=0 & VCI=2).
.IP \fBsc\fP
True if the packet is an ATM packet, for SunATM on Solaris, and is
on a signaling circuit (VPI=0 & VCI=5).
.IP \fBilmic\fP
True if the packet is an ATM packet, for SunATM on Solaris, and is
on an ILMI circuit (VPI=0 & VCI=16).
.IP \fBconnectmsg\fP
True if the packet is an ATM packet, for SunATM on Solaris, and is
on a signaling circuit and is a Q.2931 Setup, Call Proceeding, Connect,
Connect Ack, Release, or Release Done message.
.IP \fBmetaconnect\fP
True if the packet is an ATM packet, for SunATM on Solaris, and is
on a meta signaling circuit and is a Q.2931 Setup, Call Proceeding, Connect,
Release, or Release Done message.
.IP \fBfisu\fP
True if the packet is a Fill-In Signal Unit (FISU) MTP2 packet.
.IP \fBlssu\fP
True if the packet is a Link Status Signal Unit (LSSU) MTP2 packet.
.IP \fBmsu\fP
True if the packet is a Message Signal Unit (MSU) MTP2 packet.
.IP "\fBsio\fP \fIval\fR"
True if the packet has the Service Information Octet (SIO) field of the MTP2
MSU header set to the value
.IR val .
Note that this keyword does not test whether the packet is an MSU packet.
.IP "\fBdpc\fP \fIval\fR"
True if the packet has the Destination Point Code (DPC) field of the MTP3
standard routing label set to the value
.IR val .
Note that this keyword does not test whether the packet is an MTP3 packet.
.IP "\fBopc\fP \fIval\fR"
True if the packet has the Originating Point Code (OPC) field of the MTP3
standard routing label set to the value
.IR val .
Note that this keyword does not test whether the packet is an MTP3 packet.
.IP "\fBsls\fP \fIval\fR"
True if the packet has the Signalling Link Selection (SLS) field of the MTP3
standard routing label set to the value
.IR val .
Note that this keyword does not test whether the packet is an MTP3 packet.
.IP "\fBhfisu\fR, \fBhlssu\fR, \fBhmsu\fR, \fBhsio\fR, \fBhdpc\fR, \fBhopc\fR, \fBhsls\fP"
Same as
.BR fisu ,
.BR lssu ,
.BR msu ,
.BR sio ,
.BR dpc ,
.B opc
and
.B sls
respectively, but only if the MTP2 link uses the extended sequence numbers
encoding specified for high speed signalling links (HSL) in ITU-T
Recommendation Q.703 Annex A.
.IP "\fIexpr1 relop expr2\fR"
True if the relation holds. \fIRelop\fR is one of
.RB { > ,
.BR < ,
.BR >= ,
.BR <= ,
.BR = ,
.BR == ,
.BR != }
(where
.B =
means the same as
.BR == ).
Each of \fIexpr1\fR and \fIexpr2\fR is an arithmetic expression composed of
integer constants (expressed in standard C syntax), the normal binary operators
.RB { + ,
.BR - ,
.BR * ,
.BR / ,
.BR % ,
.BR & ,
.BR | ,
.BR ^ ,
.BR << ,
.BR >> },
a length operator, and special packet data
accessors. Note that all comparisons are unsigned, so that, for example,
0x80000000 and 0xffffffff are > 0.
.IP
The
.B %
and
.B ^
operators are currently only supported for filtering in the kernel on
particular operating systems (for example: FreeBSD, Linux with 3.7 and later
kernels, NetBSD); on all other systems (for example: AIX, Hurd, illumos, Solaris,
OpenBSD), if
those operators are used, filtering will be done in user mode, which
will increase the overhead of capturing packets and may cause more