To build libpcap, run ./configure (a shell script). The configure
script will determine your system attributes and generate an
appropriate Makefile from Makefile.in. 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.
If configure says:
configure: warning: cannot determine packet capture interface
configure: warning: (see INSTALL 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, 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 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. 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.
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. If you don't have any such program, the current version of Bison can be found here and the current version of Berkeley YACC can be found here.
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.
On Linux, libpcap will not work if the kernel does not have the packet socket option enabled; see this file for more information.
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 for more up to date Solaris-related information.
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 for more information specific to HP-UX.
See this file for information on installing libpcap and configuring your system to be able to support libpcap.
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.
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 tcpdump 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.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.Win32.md - notes on using libpcap on Win32 systems (with Npcap)
VERSION - version of this release
aclocal.m4 - autoconf macros
arcnet.h - ARCNET definitions
atmuni31.h - ATM Q.2931 definitions
bpf_dump.c - BPF program printing routines
bpf_filter.c - BPF filtering routines
bpf_image.c - BPF disassembly routine
config.guess - autoconf support
config.h.in - autoconf input
config.sub - autoconf support
configure - configure script (run this first)
configure.ac - configure script source
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
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
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
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
nlpid.h - OSI network layer protocol identifier definitions
optimize.c - BPF optimization routines
pcap/bluetooth.h - public definition of DLT_BLUETOOTH_HCI_H4_WITH_PHDR header
pcap/bpf.h - BPF definitions
pcap/namedb.h - public libpcap name database definitions
pcap/pcap.h - public libpcap definitions
pcap/sll.h - public definitions of DLT_LINUX_SLL and DLT_LINUX_SLL2 headers
pcap/usb.h - public definition of DLT_USB header
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-dag.c - Endace DAG device capture support
pcap-dag.h - Endace DAG device 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-enet.c - enet 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-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-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-snit.c - SunOS 4.x STREAMS-based Network Interface Tap support
pcap-snoop.c - IRIX Snoop network monitoring support
pcap-usb-linux.c - USB capture support for Linux
pcap-usb-linux.h - USB capture support for Linux
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
ppp.h - Point to Point Protocol definitions
savefile.c - offline support
scanner.l - filter string scanner
sunatmpos.h - definitions for SunATM capturing
Win32 - headers and routines for building on Win32 systems