Nessus Build and Installation Problems			3 May, 2000
	Nick Metrowsky

	Introduction

	The following are problems discovered in building and running
	nessus on Digital UNIX V4.0f.

	Building Nessus

	General

		The "make" utility that comes with any variant of Digital
		UNIX V4.0, does not work properly in building of nessus.
		To save time, and a great deal of grief, it would be a
		good idea to obtain, build and install GNU's make Utility.
		It is available from ftp://ftp.gnu.org/pub/make".

		Also, Digital UNIX's C compiler will not build parts of
		nessus. In many cases, the compiles just fail (see
		libnasl where Digital UNIX's C compiler does prove to be
		useful). Again, obtain GNU's gcc compiler from
		ftp://ftp.gnu.org/pub/gcc".


	nessus-libraries

		In the build of libpeks, the Makefile defines two variables
		for the objects from "gmp202": GMPOBJ and GMPOBJS. Object
		information for "gmp202" is defined in GMPOBJS and GMPOBJ
		is left blank. However, the variable GMPOBJ is used in
		linking "gmp202" into linpeks.  This results in undefined
		library objects for "mpz_*". 

		Workaround, copy the information for the GMPOBJS definition
		into the blank GMPOBJ definition, in
			"nessus-libraries/libpeks/Makefile".
		Before running the make of "nessus-libraries".

	libnasl

		Before continuing, make sure the path the the nessus libraries
		are in your "LD_LIBRARY_PATH" and that the path to the nessus
		binaries are in your default "PATH", else "configure" will
		not work.

		libnasl proved to be the most problematic part of building nessus,
		in so far that for some unknown reasons several modules would
		not compile under gcc, but would compile under Digital UNIX's
		C compiler. In all cases, the affected modules were complaining
		about "ip_v", "ip_hl" and other variants of the "ip" structure
		obtained from "/usr/include/netinet/ip.h". The Digital UNIX
		C compiler was able to dead with this, but gcc would display
		and error message stating the "ip_v", "ip_hl", et. al. were
		not defined in structure "ip". The affected modules are:

			udp.c, tcp.c, nessus-extensions.c, pcap_next.c, ip.c,
			icmp.c, and igmp.c  

		The workaround, was to modify "nasl.tmpl" and change "CC=gcc" to
		"CC=cc", for each of the problem modules, run the make command,
		cancel the make, change "nasl.tmpl" to use gcc, and issue the
		make command to continue. 

		In the end, libnasl was successfully built.

	nessus-core

		Fortunately, this was the easiest portion of nessus to build.
		Unfortunately, there was one minor problem with this section;
		"nasl.h" was needed in "nessus-core/include". Copying of
		"nasl.h" from "libnasl/include" to "nessus-core/include" took
		care of any problems.

	nessus-plugins

		There were two problems with nessus-plugins and they both
		involved the build of the "c" modules.

		First, a minor modification was needed to 

			nessus_plugins/plugins/install_plug

		I had to change:

			if [ -f .libs/lib$1.so.0 ];then
			test -d $2/bin/ || mkdir $2/bin/
			cp .libs/lib$1.so.0 $2/bin/$1.nes
			cp .libs/lib$1.so.0 $1.nes
			else
			if [ -f .libs/lib$1.so.0.0 ];then
			test -d $2/bin|| mkdir $2/bin
			cp .libs/lib$1.so.0.0 $2/bin/$1.nes
			cp .libs/lib$1.so.0.0 $1.nes
			fi
			fi

		to:

			if [ -f .libs/lib$1.so.0 ];then
			test -d $2/bin/ || mkdir $2/bin/
			cp .libs/lib$1.so.0 $2/bin/$1.nes
			cp .libs/lib$1.so.0 $1.nes
			fi
			if [ -f .libs/lib$1.so.0.0 ];then
			test -d $2/bin|| mkdir $2/bin
			cp .libs/lib$1.so.0.0 $2/bin/$1.nes
			cp .libs/lib$1.so.0.0 $1.nes
			fi
			if [ -f .libs/lib$1.so.0.0.0 ];then
			test -d $2/bin|| mkdir $2/bin
			cp .libs/lib$1.so.0.0.0 $2/bin/$1.nes
			cp .libs/lib$1.so.0.0.0 $1.nes
			fi


		else, the ".nes" files would not be built.

		Also, the problem mentioned earlier with building "libnasl", also
		affected the build of a couple of the modules. They would not build
		using gcc, but would with Digital UNIX C. The affected modules
		were: queso and smad. 

		The workaround, was to modify "nessus.tmpl" and change "CC=gcc" to
		"CC=cc", for each of the problem modules, run the make command,
		cancel the make, change "nessus.tmpl" to use gcc, and issue the
		make command to continue. 

		One last problem, objectserver could not be built, because a couple
		variables were not available in Digital UNIX include files.


	Running

	The main problem with nessus, is that that a message of the following
	format is generated whenever nessusd or nasl program is started or accessed:

	Unaligned access pid=24111 <nasl> va=0x140006a8c pc=0x3ffbffedf9c ra=0x3ffbffec8c8 inst=0xa6010000

	nasl, generates about 35 lines of messages containing different addresses
		for "va", "pc", "ra" and "inst".

	nessusd, generates 4 lines of messages, similar to above each time it attempts
		to load all the plugins into memory. It takes about 5 minutes for
		nessusd to complete the startup.

	Even though the messages are generated, the nasl and nessusd seem to be
	working fine.

	Other problems:

	1. When generating the HTML report containing pie charts, and saving the output,
	   the nessus program terminates abruptly with floating point error.
	   (** FIXED NOW - rd, 07/27/2000 **)
	2. Any of the scan options selected on the "Scan Options" Menu Page, causes
	   nessus to terminate the scan. If none of the options are selected, then
	   nessus will perform the security checks only.
	3. It takes a great deal of time and CPU resources to login (about 2 to 3
	   minutes on a DEC 3000/300Xl 150 mhz Alpha system).