# libpcap installation notes

# libpcap installation notes
Libpcap can be built either with the configure script and `make`, or
with CMake and any build system supported by CMake.

To build libpcap with the configure script and `make`:

* If you build from a git clone rather than from a release archive,
run `./autogen.sh` (a shell script). The autogen.sh script will
build the `configure` and `config.h.in` files.

On some system, you may need to set the `AUTORECONF` variable, like:
`AUTORECONF=autoreconf-2.69 ./autogen.sh`
to select the `autoreconf` version you want to use.

* Run `./configure` (a shell script). The configure script will
determine your system attributes and generate an appropriate `Makefile`
from `Makefile.in`. The configure script has a number of options to
control the configuration of libpcap; `./configure --help` will show
them.

* Next, run `make`. If everything goes well, you can
`su` to root and run `make install`. However, you need not install
libpcap if you just want to build tcpdump; just make sure the tcpdump
and libpcap directory trees have the same parent directory.

On OpenBSD, you may need to set, before the `make`, the `AUTOCONF_VERSION`
variable like:
`AUTOCONF_VERSION=2.69 make`

To build libpcap with CMake and the build system of your choice, from
the command line:

* Create a build directory into which CMake will put the build files it
generates; CMake does not work as well with builds done in the source
code directory as does the configure script. The build directory may be
created as a subdirectory of the source directory or as a directory
outside the source directory.

* Change to the build directory and run CMake with the path from the
build directory to the source directory as an argument. The `-G` flag
can be used to select the CMake "generator" appropriate for the build
system you're using; various `-D` flags can be used to control the
configuration of libpcap.

* Run the build tool. If everything goes well, you can `su` to root and
run the build tool with the `install` target. Building tcpdump from a
libpcap in a build directory is not supported.

An `uninstall` target is supported with both `./configure` and CMake.

***DO NOT*** run the build as root; there is no need to do so, running
anything as root that doesn't need to be run as root increases the risk
of damaging your system, and running the build as root will put files in
the build directory that are owned by root and that probably cannot be
overwritten, removed, or replaced except by root, which could cause
permission errors in subsequent builds.

If configure says:

configure: warning: cannot determine packet capture interface
configure: warning: (see INSTALL.md file for more info)

or CMake says:

cannot determine packet capture interface

(see the INSTALL.md file for more info)

then your system either does not support packet capture or your system
does support packet capture but libpcap does not support that
particular type. (If you have HP-UX, see below.) If your system uses a
packet capture not supported by libpcap, please send us patches; don't
forget to include an autoconf fragment suitable for use in
`configure.ac`.

It is possible to override the default packet capture type with the
`--with-pcap` option to `./configure` or the `-DPCAP_TYPE` option to
CMake, although the circumstances where this works are limited. One
possible reason to do that would be to force a supported packet capture
type in the case where the configure or CMake scripts fails to detect
it.

You will need a C99 compiler to build libpcap. The configure script
will abort if your compiler is not C99 compliant. If this happens, use
the generally available GNU C compiler (GCC) or Clang.

You will need either Flex 2.5.31 or later, or a version of Lex
compatible with it (if any exist), to build libpcap. The configure
script will abort if there isn't any such program; CMake fails if Flex
or Lex cannot be found, but doesn't ensure that it's compatible with
Flex 2.5.31 or later. If you have an older version of Flex, or don't
have a compatible version of Lex, the current version of Flex is
available [here](https://github.com/westes/flex).

You will need either Bison, Berkeley YACC, or a version of YACC
compatible with them (if any exist), to build libpcap. The configure
script will abort if there isn't any such program; CMake fails if Bison
or some form of YACC cannot be found, but doesn't ensure that it's
compatible with Bison or Berkeley YACC. If you don't have any such
program, the current version of Bison can be found
[here](https://ftp.gnu.org/gnu/bison/) and the current version of
Berkeley YACC can be found [here](https://invisible-island.net/byacc/).

Sometimes the stock C compiler does not interact well with Flex and
Bison. The list of problems includes undefined references for alloca(3).
You can get around this by installing GCC.

## Linux specifics
On Linux, libpcap will not work if the kernel does not have the packet
socket option enabled; see [this file](doc/README.linux) for more
information.

## Solaris specifics
If you use the SPARCompiler, you must be careful to not use the
`/usr/ucb/cc` interface. If you do, you will get bogus warnings and
perhaps errors. Either make sure your path has `/opt/SUNWspro/bin`
before `/usr/ucb` or else:

setenv CC /opt/SUNWspro/bin/cc

before running configure. (You might have to do a `make distclean`
if you already ran `configure` once).

See [this file](doc/README.solaris.md) for more up to date
Solaris-related information.

## HP-UX specifics
If you use HP-UX, you must have at least version 9 and either the
version of `cc` that supports C99 (`cc -AC99`) or else use the GNU C
compiler. You must also buy the optional streams package. If you don't
have:

/usr/include/sys/dlpi.h
/usr/include/sys/dlpi_ext.h

then you don't have the streams package. In addition, we believe you
need to install the "9.X LAN and DLPI drivers cumulative" patch
(PHNE_6855) to make the version 9 DLPI work with libpcap.

The DLPI streams package is standard starting with HP-UX 10.

The HP implementation of DLPI is a little bit eccentric. Unlike
Solaris, you must attach `/dev/dlpi` instead of the specific `/dev/*`
network pseudo device entry in order to capture packets. The PPA is
based on the ifnet "index" number. Under HP-UX 9, it is necessary to
read `/dev/kmem` and the kernel symbol file (`/hp-ux`). Under HP-UX 10,
DLPI can provide information for determining the PPA. It does not seem
to be possible to trace the loopback interface. Unlike other DLPI
implementations, PHYS implies MULTI and SAP and you get an error if you
try to enable more than one promiscuous mode at a time.

It is impossible to capture outbound packets on HP-UX 9. To do so on
HP-UX 10, you will, apparently, need a late "LAN products cumulative
patch" (at one point, it was claimed that this would be PHNE_18173 for
s700/10.20; at another point, it was claimed that the required patches
were PHNE_20892, PHNE_20725 and PHCO_10947, or newer patches), and to do
so on HP-UX 11 you will, apparently, need the latest lancommon/DLPI
patches and the latest driver patch for the interface(s) in use on HP-UX
11 (at one point, it was claimed that patches PHNE_19766, PHNE_19826,
PHNE_20008, and PHNE_20735 did the trick).

Furthermore, on HP-UX 10, you will need to turn on a kernel switch by
doing

echo 'lanc_outbound_promisc_flag/W 1' | adb -w /stand/vmunix /dev/mem

You would have to arrange that this happens on reboots; the right way to
do that would probably be to put it into an executable script file
`/sbin/init.d/outbound_promisc` and making
`/sbin/rc2.d/S350outbound_promisc` a symbolic link to that script.

Finally, testing shows that there can't be more than one simultaneous
DLPI user per network interface.

See [this file](doc/README.hpux) for more information specific to HP-UX.

## AIX specifics
See [this file](doc/README.aix) for information on installing libpcap and
configuring your system to be able to support libpcap.

## other specifics
If you are trying to do packet capture with a FORE ATM card, you may or
may not be able to. They usually only release their driver in object
code so unless their driver supports packet capture, there's not much
libpcap can do.

If you get an error like:

tcpdump: recv_ack: bind error 0x???

when using DLPI, look for the DL_ERROR_ACK error return values, usually
in `/usr/include/sys/dlpi.h`, and find the corresponding value.

## Description of files
CHANGES - description of differences between releases
ChmodBPF/* - macOS startup item to set ownership and permissions on /dev/bpf*
CMakeLists.txt - CMake file
CONTRIBUTING.md - guidelines for contributing
CREDITS - people that have helped libpcap along
INSTALL.md - this file
LICENSE - the license under which libpcap is distributed
Makefile.in - compilation rules (input to the configure script)
README.md - description of distribution
doc/README.aix - notes on using libpcap on AIX
doc/README.dag - notes on using libpcap to capture on Endace DAG devices
doc/README.haiku.md - notes on using libpcap on Haiku
doc/README.hpux - notes on using libpcap on HP-UX
doc/README.linux - notes on using libpcap on Linux
doc/README.macos - notes on using libpcap on macOS
doc/README.septel - notes on using libpcap to capture on Intel/Septel devices
doc/README.sita - notes on using libpcap to capture on SITA devices
doc/README.solaris.md - notes on using libpcap on Solaris
doc/README.windows.md - notes on using libpcap on Windows systems (with Npcap)
VERSION - version of this release
aclocal.m4 - autoconf macros
arcnet.h - ARCNET definitions
atmuni31.h - ATM Q.2931 definitions
autogen.sh - build configure and config.h.in (run this first)
bpf_dump.c - BPF program printing routines
bpf_filter.c - BPF filtering routines
bpf_image.c - BPF disassembly routine
charconv.c - Windows Unicode routines
charconv.h - Windows Unicode prototypes
config.guess - autoconf support
config.sub - autoconf support
configure.ac - configure script source
diag-control.h - compiler diagnostics control macros
dlpisubs.c - DLPI-related functions for pcap-dlpi.c and pcap-libdlpi.c
dlpisubs.h - DLPI-related function declarations
etherent.c - /etc/ethers support routines
extract.h - Alignment definitions
ethertype.h - Ethernet protocol types and names definitions
fad-getad.c - pcap_findalldevs() for systems with getifaddrs()
fad-gifc.c - pcap_findalldevs() for systems with only SIOCGIFLIST
fad-glifc.c - pcap_findalldevs() for systems with SIOCGLIFCONF
fmtutils.c - error message formatting routines
fmtutils.h - error message formatting prototypes
ftmacros.h - feature test macros
testprogs/filtertest.c - test program for BPF compiler
testprogs/findalldevstest.c - test program for pcap_findalldevs()
gencode.c - BPF code generation routines
gencode.h - BPF code generation definitions
grammar.y - filter string grammar
ieee80211.h - 802.11 definitions
install-sh - BSD style install script
instrument-functions.c - functions instrumentation calls for entry/exit
lbl/os-*.h - OS-dependent defines and prototypes
llc.h - 802.2 LLC SAP definitions
missing/* - replacements for missing library functions
mkdep - construct Makefile dependency list
msdos/* - drivers for MS-DOS capture support
nametoaddr.c - hostname to address routines
nametoaddr.h - hostname to address prototypes
nlpid.h - OSI network layer protocol identifier definitions
optimize.c - BPF optimization routines
optimize.h - BPF optimization prototypes
pcap/bluetooth.h - public definition of DLT_BLUETOOTH_HCI_H4_WITH_PHDR header
pcap/bpf.h - BPF definitions
pcap/can_socketcan.h - SocketCAN header
pcap/compiler-tests.h - compiler version comparison and other macros
pcap/dlt.h - Link-layer header type codes.
pcap/funcattrs.h - function attribute macros
pcap/ipnet.h - Solaris IPnet definitions
pcap/namedb.h - public libpcap name database definitions
pcap/nflog.h - NFLOG-related definitions
pcap/pcap.h - public libpcap definitions
pcap/pcap-inttypes.h - header for OS-specific integer type includes
pcap/sll.h - public definitions of DLT_LINUX_SLL and DLT_LINUX_SLL2 headers
pcap/socket.h - IP sockets support for various OSes
pcap/usb.h - public definition of DLT_USB header
pcap/vlan.h - VLAN-specific definitions
pcap-airpcap.c - AirPcap device capture support
pcap-airpcap.h - AirPcap device capture support
pcap-bpf.c - BSD Packet Filter support
pcap-bpf.h - header for backwards compatibility
pcap-bt-linux.c - Bluetooth capture support for Linux
pcap-bt-linux.h - Bluetooth capture support for Linux
pcap-bt-monitor-linux.c - Bluetooth monitor capture support for Linux
pcap-bt-monitor-linux.h - Bluetooth monitor capture support for Linux
pcap-common.c - common code for pcap and pcapng files
pcap-common.h - common code for pcap and pcapng files
pcap-dag.c - Endace DAG device capture support
pcap-dag.h - Endace DAG device capture support
pcap-dbus.c - D-Bus capture support
pcap-dbus.h - D-Bus capture support
pcap-dlpi.c - Data Link Provider Interface support
pcap-dos.c - MS-DOS capture support
pcap-dos.h - headers for MS-DOS capture support
pcap-dpdk.c - DPDK device support
pcap-dpdk.h - DPDK device support
pcap-enet.c - enet support
pcap-haiku.c - Haiku capture support
pcap-int.h - internal libpcap definitions
pcap-libdlpi.c - Data Link Provider Interface support for systems with libdlpi
pcap-linux.c - Linux packet socket support
pcap-namedb.h - header for backwards compatibility
pcap-netfilter-linux.c - Linux netfilter support
pcap-netfilter-linux.h - Linux netfilter support
pcap-netmap.c - netmap support
pcap-netmap.h - netmap support
pcap-nit.c - SunOS Network Interface Tap support
pcap-npf.c - Npcap capture support
pcap-null.c - dummy monitor support (allows offline use of libpcap)
pcap-pf.c - Ultrix and Digital/Tru64 UNIX Packet Filter support
pcap-rdmasniff.c - RDMA/InfiniBand capture support
pcap-rdmasniff.h - RDMA/InfiniBand capture support
pcap-rpcap.c - RPCAP protocol capture support
pcap-rpcap.h - RPCAP protocol capture support
pcap-septel.c - Intel/Septel device capture support
pcap-septel.h - Intel/Septel device capture support
pcap-sita.c - SITA device capture support
pcap-sita.h - SITA device capture support
pcap-sita.html - SITA device capture documentation
pcap-snf.c - Myricom SNF device capture support
pcap-snf.h - Myricom SNF device capture support
pcap-snit.c - SunOS 4.x STREAMS-based Network Interface Tap support
pcap-snoop.c - IRIX Snoop network monitoring support
pcap-tc.c - TurboCap device capture support
pcap-tc.h - TurboCap device capture support
pcap-types.h - header for OS-specific type includes
pcap-usb-linux.c - USB capture support for Linux
pcap-usb-linux.h - USB capture support for Linux
pcap-usb-linux-common.c - Linux USB common routines
pcap-usb-linux-common.h - Linux USB common prototypes
pcap-util.c - common code for various files
pcap-util.h - common code for various files
pcap.3pcap - manual entry for the library
pcap.c - pcap utility routines
pcap.h - header for backwards compatibility
pcap_*.3pcap - manual entries for library functions
pcap-filter.manmisc.in - manual entry for filter syntax
pcap-linktype.manmisc.in - manual entry for link-layer header types
pflog.h - header for DLT_PFLOG handling in filter code
portability.h - Portability declarations/definitions
ppp.h - Point to Point Protocol definitions
rpcap-protocol.c - RPCAP client/server common routines
rpcap-protocol.h - RPCAP client/server common prototypes
savefile.c - offline support
scanner.l - filter string scanner
sf-pcap.c - routines for .pcap savefiles
sf-pcap.h - prototypes for .pcap savefiles
sf-pcapng.c - routines for .pcapng savefiles
sf-pcapng.h - prototypes for .pcapng savefiles
sockutils.c - socket and name lookup API routines
sockutils.h - socket and name lookup API prototypes
sslutils.c - OpenSSL interface routines
sslutils.h - OpenSSL interface prototypes
sunatmpos.h - definitions for SunATM capturing
varattrs.h - variable attribute macros