The "generic" notes for putting this thing together are below. Here's the short version. 1.) *** Make sure you have libpcap and libpcre installed!!! *** 2.) ./configure 3.) make 4.) make install 5.) Create a sample rules file (if you want to use rules, check out the included snort.conf file) 6.) snort -? 7.) If you've used previous versions of Snort, you may need to rewrite your rules to make them compliant to the rules format. See snort_manual.pdf or http://www.snort.org for more information. 8.) Have fun! Any questions? Sign up to the snort-users mailing list at http://www.snort.org! Snort Configure-time switches ============================= `--enable-debug' Enable debugging options (bugreports and developers only). `--enable-pthread' Enable pthread support (causes snort to be linked with libpthread). `--enable-prelude' Enable Prelude Hydrid IDS support. `--enable-rulestate' Enable rule state configuration feature that seperates the rule state (enabled/disabled) from the action (alert, drop, log, etc) and definition. `--enable-dynamicplugin' Enable dynamically loadable preprocessors, detection engine and rules libraries. `--enable-timestats' Enable real-time performance statistics. `--enable-perfprofiling' Enable performance profiling of individual rules and preprocessors. `--enable-linux-smp-stats' Enable CPU performance statistics through proc. `--enable-inline' Use the libipq interface for inline mode. May require --with-libipq options. `--enable-ipfw' Use the IPFW divert sockets for inline mode. `--enable-react' Enable interception and termination of offending HTTP accesses. `--enable-flexresp' Enable the 'Flexible Response' code, that allows you to cancel hostile connections on IP-level when a rule matches. When you enable this feature, you also need the 'libnet'-library that can be found at http://www.packetfactory.net/libnet. See README.FLEXRESP for details. `--enable-flexresp2' Enable the 'Flexible Response, version 2' code, that allows you to cancel hostile connections on IP-level when a rule matches. When you enable this feature, you also need the 'libnet'-library that can be found at http://www.packetfactory.net/libnet. See README.FLEXRESP2 for details. `--enable-aruba' Enable the Aruba output plugin capability that allows you to send information to an Aruba Networks Mobility Controller. See README.ARUBA for details. `--enable-gre' Enable GRE decoder. Allows Snort to decode GRE encapsulated traffic. Only supports GRE over IP. Only one layer of encapsulation will be decoded - packets with multiple GRE headers will be alerted and discarded/blocked. `--with-snmp' Enable SNMP alerting code. `--with-mysql=DIR' Support for mysql, turn this on if you want to use ACID with MySQL. NOTE: Specifying a directory will be deprecated in the future. `--with-mysql-libraries=DIR' Specify location for mysql client library. `--with-mysql-includes=DIR' Specify location for mysql header files. `--with-odbc=DIR' Support for ODBC databases, turn this on if you want to use ACID with a non-listed DB. `--with-postgresql=DIR' Support for Postgresql databases, turn this on if you want to use ACID with PostgreSQL. `--with-oracle=DIR' Support for Oracle databases, turn this on if you want to use ACID with Oracle. `--with-openssl=DIR' Support for openssl (used by the XML output plugin). `--with-libpq-includes=DIR' Set the include directories for Postgres SQL database support to DIR. `--with-libpq-libraries=DIR' Set the library directories for Postgres SQL database support to DIR. Setting both of these values enables the Postgres output plugin module. `--with-libpcap-includes=DIR' If the configuration script can't find the libpcap include files on its own, the path can be set manually with this switch. `--with-libpcap-libraries=DIR' If the configuration script can't find the libpcap library files on its own, the path can be set manually with this switch. `--with-libxml2-includes=DIR' Libxml2 include directory. `--with-libxml2-libraries=DIR' Libxml2 library directory. `--with-libntp-libraries=DIR' Libntp library directory. `--with-libidmef-includes=DIR' Libidmef include directory. `--with-libidmef-libraries=DIR' Libidmef library directory. Basic Installation ================== These are generic installation instructions. The `configure' shell script attempts to guess correct values for various system-dependent variables used during compilation. It uses those values to create a `Makefile' in each directory of the package. It may also create one or more `.h' files containing system-dependent definitions. Finally, it creates a shell script `config.status' that you can run in the future to recreate the current configuration, a file `config.cache' that saves the results of its tests to speed up reconfiguring, and a file `config.log' containing compiler output (useful mainly for debugging `configure'). If you need to do unusual things to compile the package, please try to figure out how `configure' could check whether to do them, and mail diffs or instructions to the address given in the `README' so they can be considered for the next release. If at some point `config.cache' contains results you don't want to keep, you may remove or edit it. The file `configure.in' is used to create `configure' by a program called `autoconf'. You only need `configure.in' if you want to change it or regenerate `configure' using a newer version of `autoconf'. The simplest way to compile this package is: 1. `cd' to the directory containing the package's source code and type `./configure' to configure the package for your system. If you're using `csh' on an old version of System V, you might need to type `sh ./configure' instead to prevent `csh' from trying to execute `configure' itself. Running `configure' takes awhile. While running, it prints some messages telling which features it is checking for. 2. Type `make' to compile the package. 3. Optionally, type `make check' to run any self-tests that come with the package. 4. Type `make install' to install the programs and any data files and documentation. 5. You can remove the program binaries and object files from the source code directory by typing `make clean'. To also remove the files that `configure' created (so you can compile the package for a different kind of computer), type `make distclean'. There is also a `make maintainer-clean' target, but that is intended mainly for the package's developers. If you use it, you may have to get all sorts of other programs in order to regenerate files that came with the distribution. Compilers and Options ===================== Some systems require unusual options for compilation or linking that the `configure' script does not know about. You can give `configure' initial values for variables by setting them in the environment. Using a Bourne-compatible shell, you can do that on the command line like this: CC=c89 CFLAGS=-O2 LIBS=-lposix ./configure Or on systems that have the `env' program, you can do it like this: env CPPFLAGS=-I/usr/local/include LDFLAGS=-s ./configure Compiling For Multiple Architectures ==================================== You can compile the package for more than one kind of computer at the same time, by placing the object files for each architecture in their own directory. To do this, you must use a version of `make' that supports the `VPATH' variable, such as GNU `make'. `cd' to the directory where you want the object files and executables to go and run the `configure' script. `configure' automatically checks for the source code in the directory that `configure' is in and in `..'. If you have to use a `make' that does not supports the `VPATH' variable, you have to compile the package for one architecture at a time in the source code directory. After you have installed the package for one architecture, use `make distclean' before reconfiguring for another architecture. Installation Names ================== By default, `make install' will install the package's files in `/usr/local/bin', `/usr/local/man', etc. You can specify an installation prefix other than `/usr/local' by giving `configure' the option `--prefix=PATH'. You can specify separate installation prefixes for architecture-specific files and architecture-independent files. If you give `configure' the option `--exec-prefix=PATH', the package will use PATH as the prefix for installing programs and libraries. Documentation and other data files will still use the regular prefix. In addition, if you use an unusual directory layout you can give options like `--bindir=PATH' to specify different values for particular kinds of files. Run `configure --help' for a list of the directories you can set and what kinds of files go in them. If the package supports it, you can cause programs to be installed with an extra prefix or suffix on their names by giving `configure' the option `--program-prefix=PREFIX' or `--program-suffix=SUFFIX'. Optional Features ================= Some packages pay attention to `--enable-FEATURE' options to `configure', where FEATURE indicates an optional part of the package. They may also pay attention to `--with-PACKAGE' options, where PACKAGE is something like `gnu-as' or `x' (for the X Window System). The `README' should mention any `--enable-' and `--with-' options that the package recognizes. For packages that use the X Window System, `configure' can usually find the X include and library files automatically, but if it doesn't, you can use the `configure' options `--x-includes=DIR' and `--x-libraries=DIR' to specify their locations. The following configuration switches are available for Snort: `--enable-flexresp' Enable the 'Flexible Response' code, that allows you to cancel hostile connections on IP-level when a rule matches. When you enable this feature, you also need the 'libnet'-library that can be found at http://www.packetfactory.net/libnet. See README.FLEXRESP for details. This function is still ALPHA, so use with caution. Specifying the System Type ========================== There may be some features `configure' can not figure out automatically, but needs to determine by the type of host the package will run on. Usually `configure' can figure that out, but if it prints a message saying it can not guess the host type, give it the `--host=TYPE' option. TYPE can either be a short name for the system type, such as `sun4', or a canonical name with three fields: CPU-COMPANY-SYSTEM See the file `config.sub' for the possible values of each field. If `config.sub' isn't included in this package, then this package doesn't need to know the host type. If you are building compiler tools for cross-compiling, you can also use the `--target=TYPE' option to select the type of system they will produce code for and the `--build=TYPE' option to select the type of system on which you are compiling the package. Sharing Defaults ================ If you want to set default values for `configure' scripts to share, you can create a site shell script called `config.site' that gives default values for variables like `CC', `cache_file', and `prefix'. `configure' looks for `PREFIX/share/config.site' if it exists, then `PREFIX/etc/config.site' if it exists. Or, you can set the `CONFIG_SITE' environment variable to the location of the site script. A warning: not all `configure' scripts look for a site script. Operation Controls ================== `configure' recognizes the following options to control how it operates. `--cache-file=FILE' Use and save the results of the tests in FILE instead of `./config.cache'. Set FILE to `/dev/null' to disable caching, for debugging `configure'. `--help' Print a summary of the options to `configure', and exit. `--quiet' `--silent' `-q' Do not print messages saying which checks are being made. To suppress all normal output, redirect it to `/dev/null' (any error messages will still be shown). `--srcdir=DIR' Look for the package's source code in directory DIR. Usually `configure' can determine that directory automatically. `--version' Print the version of Autoconf used to generate the `configure' script, and exit. `configure' also accepts some other, not widely useful, options. Platform Specific Notes ======================= * 64bit platforms: ------------------ On some 64bit Linux systems (e.g. with Fedora distributions), when configuring snort with MySQL output support, the necessary library may not be found automatically by the configure script, giving the following error when 'configure' is run: ********************************************** ERROR: unable to find mysqlclient library (libmysqlclient.*) checked in the following places /usr /usr/lib /usr/mysql /usr/mysql/lib /usr/local /usr/local/lib /usr/local/mysql /usr/local/mysql/lib ********************************************** In this case, libmysqlclient.* may actually be found in /usr/lib64/mysql, and the path will need to be explicitly specified in this manner: configure --with-mysql-libraries=/usr/lib64/mysql Note, you may also specify alternate locations for the mysql header files using --with-mysql-includes. Specifying a directory as part of the --with-mysql option to configure will be deprecated in the future. Problems may also be encountered if both the 32bit and 64bit libraries are installed on the system, and configuring snort with MySQL support may result in a different error: checking for mysql... yes checking for compress in -lz... yes checking for dlsym in -ldl... no checking for dlsym in -lc... no ERROR! programmatic interface to dynamic link loader not found. Cannot use dynamic plugin libraries. Reading through config.log, you may see something like this (the numbers are the line number and may differ): configure:24280: checking for dlsym in -ldl configure:24310: gcc -o conftest -g -O2 -Wall -DDYNAMIC_PLUGIN -I/usr/include/mysql -DENABLE_MYSQL -lpcre -L/usr/lib/mysql conftest.c -ldl -lmysqlclient -lz -lpcre -lpcap -lm -lnsl >&5 /usr/bin/ld: skipping incompatible /usr/lib/mysql/libmysqlclient.so when searching for -lmysqlclient /usr/bin/ld: skipping incompatible /usr/lib/mysql/libmysqlclient.a when searching for -lmysqlclient /usr/bin/ld: cannot find -lmysqlclient collect2: ld returned 1 exit status configure:24316: $? = 1 This likely indicates a compability issue between a 32bit library from mysql (found in its normal location), and a 64bit library for libdl (dynamic loader). Use the --with-mysql-libraries option to specify the location of the 64bit mysql library (e.g. /usr/lib64/mysql). * Linux: -------- With kernels 2.2.x and higher you may get `snort [pid] uses obsolete (PF_INET, SOCK_PACKET)' warnings. This is because you use some older implementation of libpcap library and you need an upgrade. The recent version of libpcap could be found at www.tcpdump.org page. On linux with kernels 2.2.x and higher you may also get feature to monitor several interfaces down to network level (session + TCP + IP) if you link your snort with the lattest version of libpcap which incorporates Sebastian Krahmer's patch for interface 'any'. (Consult http://www.tcpdump.org for details). * IRIX ------ [ noticed by Scott A. McIntyre <scott@whoi.edu> ] There's problem with GCC on IRIX platform which causes certain missbehaviour of snort. From the SGI web site: Gcc does not correctly pass/return structures which are smaller than 16 bytes and which are not 8 bytes. The problem is very involved and difficult to fix. It affects a number of other targets also, but irix6 is affected the most, because it is a 64 bit target, and 4 byte structures are common. The exact problem is that structures are being padded at the wrong end, e.g. a 4 byte structure is loaded into the lower 4 bytes of the register when it should be loaded into the upper 4 bytes of the register. Gcc is consistent with itself, but not consistent with the SGI C compiler [and the SGI supplied runtime libraries], so the only failures that can happen are when there are library functions that take/return such structures. There are very few such library functions. I can only recall seeing a few of them: inet_ntoa, inet_aton, inet_lnaof, inet_netof, and semctl. A possible workaround: if you have a program that calls inet_ntoa and friends or semctl, and your kernel supports 64-bit binaries (i.e. uname -a prints IRIX64 rather than just IRIX), then you may compile with gcc -mabi=64 to workaround this problem. More information is available at: http://freeware.sgi.com/2000Feb/Installable/gcc-2.8.1-sgipl2.html * MAC OSX --------- On Darwin (maybe others), the configure script shipped as part of the source distribution may need to be recreated. To do this, run the following commands: glibtoolize --force aclocal -I m4 autoheader automake --add-missing --copy autoconf Snort needs to be linked using the two level namespace. To do this, set the LD_TWOLEVEL_NAMESPACE environment variable to something prior to running configure. An example: $ export LD_TWOLEVEL_NAMESPACE=1 $ ./configure $ make * MAC OSX TIGER & LEOPARD ------------------------- For users of MAC OSX 10.5 (Leopard), the following environment variables must be set before running configure & make. For users of MAC OSX 10.4 (Tiger), this also applies if the compiler has been updated, otherwise, the instructions above may be used. Reference information for MAC OSX can be found at these two links. http://developer.apple.com/releasenotes/Darwin/SymbolVariantsRelNotes http://lists.apple.com/archives/xcode-users/2007/Jun/msg00163.html $ export LD_TWOLEVEL_NAMESPACE=1 $ export MACOSX_DEPLOYMENT_TARGET=10.5 $ ./configure $ make * Open BSD / Free BSD / MAC OSX ------------------------------- On certain BSD-based platforms, the make install may not symlink the version specific shared libraries to the non-versioned shared library. This could cause a failure to load when using dynamic libraries. Work arounds: 1) Create the symlink's by hand after make install. The shared libraries can be located under /usr/local/lib/snort_dynamicengine and /usr/local/lib/snort_dynamicpreprocessor. If necessary, symlink the .so.0 or .0.so files to a corresponding .so. 2) Use the --dynamic-preprocessor-lib (rather than --dynamic-preprocessor-lib-dir) to load the version specific shared library. 3) Use the config directive dynamicpreprocessor file (rather than dynamicpreprocessor directory) to load the version specific shared library. * FreeBSD 6.x ------------- If you run the auto tools (instead of using the delivered configure script), you may need to include -I /usr/local/share/aclocal (in addition to -I m4) as arguments to aclocal. This is required to set up the correct info for using LIBTOOL with aclocal version 1.9 that ships with FreeBSD. In this case, the following recommended commands should be used to configure snort prior to using make: libtoolize --automake --copy aclocal -I m4 -I /usr/local/share/aclocal autoheader automake --add-missing --copy autoconf Then run configure with any desired options (--enable-dynamicplugin, --enable-inline, etc).