xref: /freebsd-11.0-release/contrib/sendmail/src/README

# Copyright (c) 1998 Sendmail, Inc.  All rights reserved.
# Copyright (c) 1983, 1995-1997 Eric P. Allman.  All rights reserved.
# Copyright (c) 1988
#	The Regents of the University of California.  All rights reserved.
#
# By using this file, you agree to the terms and conditions set
# forth in the LICENSE file which can be found at the top level of
# the sendmail distribution.
#
#
#	@(#)README	8.209 (Berkeley) 10/6/1998
#

This directory contains the source files for sendmail(TM).

*********************
!! DO NOT USE MAKE !!  in this directory to compile sendmail --
*********************  instead, use the "Build" script located in
the src directory.  It will build an appropriate Makefile, and
create an appropriate obj.* subdirectory so that multiplatform
support works easily.

	**********************************************************
	**  Read below for more details on building sendmail.	**
	**********************************************************

**************************************************************************
**  IMPORTANT:  Read the appropriate paragraphs in the section on	**
**  ``Operating System and Compile Quirks''.				**
**************************************************************************

For detailed instructions, please read the document ../doc/op/op.me:

	eqn ../doc/op/op.me | pic | ditroff -me

Sendmail is a trademark of Sendmail, Inc.


+-------------------+
| BUILDING SENDMAIL |
+-------------------+

By far, the easiest way to compile sendmail is to use the "Build"
script:

	sh Build

This uses the "uname" command to figure out what architecture you are
on and creates a proper Makefile accordingly.  It also creates a
subdirectory per object format, so that multiarchitecture support is
easy.  In general this should be all you need.  IRIX 6.x users should
read the note below in the OPERATING SYSTEM AND COMPILE QUIRKS section.

If you need to look at other include or library directories, use the
-I or -L flags on the command line, e.g.,

	sh Build -I/usr/sww/include -L/usr/sww/lib

It's also possible to create local site configuration in the file
site.config.m4 (or another file settable with the -f flag).  This
file contains M4 definitions for various compilation values; the
most useful are:

confMAPDEF	-D flags to specify database types to be included
		(see below)
confENVDEF	-D flags to specify other environment information
confINCDIRS	-I flags for finding include files during compilation
confLIBDIRS	-L flags for finding libraries during linking
confLIBS	-l flags for selecting libraries during linking
confLDOPTS	other ld(1) linker options

Others can be found by examining Makefile.m4.  Please read
../BuildTools/README for more information about the site.config.m4
file.

You can recompile from scratch using the -c flag with the Build
command.  This removes the existing compilation directory for the
current platform and builds a new one.

Porting to a new Unix-based system should be a matter of creating
an appropriate configuration file in the BuildTools/OS/ directory.



+----------------------+
| DATABASE DEFINITIONS |
+----------------------+

There are several database formats that can be used for the alias files
and for general maps.  When used for alias files they interact in an
attempt to be backward compatible.

The options are:

NEWDB		The new Berkeley DB package.  Some systems (e.g., BSD/OS and
		Digital UNIX 4.0) have some version of this package
		pre-installed.  If your system does not have Berkeley DB
		pre-installed, or the version installed is not version 2.0
		or greater (e.g., is Berkeley DB 1.85 or 1.86), get the
		current version from http://www.sleepycat.com/.  DO NOT
		use a version from any of the University of California,
		Berkeley "Net" or other distributions.  If you are still
		running BSD/386 1.x, you will need to upgrade the included
		Berkeley DB library to a current version.  NEWDB is included
		automatically if the Build script can find a library named
		libdb.a.
NDBM		The older NDBM implementation -- the very old V7 DBM
		implementation is no longer supported.
NIS		Network Information Services.  To use this you must have
		NIS support on your system.
NISPLUS		NIS+ (the revised NIS released with Solaris 2).  You must
		have NIS+ support on your system to use this flag.
HESIOD		Support for Hesiod (from the DEC/Athena distribution).  You
		must already have Hesiod support on your system for this to
		work.  You may be able to get this to work with the MIT/Athena
		version of Hesiod, but that's likely to be a lot of work.
LDAPMAP		Lightweight Directory Lookup Protocol support.  You will
		have to install the UMich ldap and lber libraries to use
		this flag.
MAP_REGEX	Regular Expression support.  You will need to use an
		operating system which comes with the POSIX regex()
		routines or install a regexp library such as libregex from
		the Free Software Foundation.

>>>  NOTE WELL for NEWDB support: If you want to get ndbm support, for
>>>  Berkeley DB versions under 2.0, it is CRITICAL that you remove
>>>  ndbm.o from libdb.a before you install it and DO NOT install ndbm.h;
>>>  for Berkeley DB versions 2.0 through 2.3.14, remove dbm.o from libdb.a
>>>  before you install it.  If you don't delete these, there is absolutely
>>>  no point to including -DNDBM, since it will just get you another
>>>  (inferior) API to the same format database.  These files OVERRIDE
>>>  calls to ndbm routines -- in particular, if you leave ndbm.h in,
>>>  you can find yourself using the new db package even if you don't
>>>  define NEWDB.  Berkeley DB versions later than 2.3.14 do not need
>>>  to be modified.  Please also consult the README in the top level
>>>  directory of the sendmail distribution for other important information.
>>>
>>>  Further note: DO NOT remove your existing /usr/include/ndbm.h --
>>>  you need that one.  But do not install an updated ndbm.h in
>>>  /usr/include, /usr/local/include, or anywhere else.

If NEWDB and NDBM are defined (but not NIS), then sendmail will read
NDBM format alias files, but the next time a newaliases is run the
format will be converted to NEWDB; that format will be used forever
more.  This is intended as a transition feature.

If NEWDB, NDBM, and NIS are all defined and the name of the file includes
the string "/yp/", sendmail will rebuild BOTH the NEWDB and NDBM format
alias files.  However, it will only read the NEWDB file; the NDBM format
file is used only by the NIS subsystem.  This is needed because the NIS
maps on an NIS server are built directly from the NDBM files.

If NDBM and NIS are defined (regardless of the definition of NEWDB),
and the filename includes the string "/yp/", sendmail adds the special
tokens "YP_LAST_MODIFIED" and "YP_MASTER_NAME", both of which are
required if the NDBM file is to be used as an NIS map.

All of these flags are normally defined in the DBMDEF line in the
Makefile.

If you define NEWDB or HESIOD you get the User Database (USERDB)
automatically.  Generally you do want to have NEWDB for it to do
anything interesting.  See above for getting the Berkeley DB
package (i.e., NEWDB).  There is no separate "user database"
package -- don't bother searching for it on the net.

Hesiod and LDAP require libraries that may not be installed with your
system.  These are outside of my ability to provide support.  See the
"Quirks" section for more information.

The regex map can be used to see if an address matches a certain regular
expression.  For example, all-numerics local parts are common spam
addresses, so "^[0-9]+$" would match this.  By using such a map in a
check_* rule-set, you can block a certain range of addresses that would
otherwise be considered valid.

+---------------+
| COMPILE FLAGS |
+---------------+

Wherever possible, I try to make sendmail pull in the correct
compilation options needed to compile on various environments based on
automatically defined symbols.  Some machines don't seem to have useful
symbols available, requiring that a compilation flag be defined in
the Makefile; see the Buildtools/OS subdirectory for the supported
architectures.

If you are a system to which sendmail has already been ported you
should not have to touch the following symbols.  But if you are porting,
you may have to tweak the following compilation flags in conf.h in order
to get it to compile and link properly:

SYSTEM5		Adjust for System V (not necessarily Release 4).
SYS5SIGNALS	Use System V signal semantics -- the signal handler
		is automatically dropped when the signal is caught.
		If this is not set, use POSIX/BSD semantics, where the
		signal handler stays in force until an exec or an
		explicit delete.  Implied by SYSTEM5.
SYS5SETPGRP	Use System V setpgrp() semantics.  Implied by SYSTEM5.
HASFCHMOD	Define this to one if you have the fchmod(2) system call.
		This improves security.
HASFLOCK	Set this if you prefer to use the flock(2) system call
		rather than using fcntl-based locking.  Fcntl locking
		has some semantic gotchas, but many vendor systems
		also interface it to lockd(8) to do NFS-style locking.
		Unfortunately, may vendors implementations of fcntl locking
		is just plain broken (e.g., locks are never released,
		causing your sendmail to deadlock; when the kernel runs
		out of locks your system crashes).  For this reason, I
		recommend always defining this unless you are absolutely
		certain that your fcntl locking implementation really works.
HASUNAME	Set if you have the "uname" system call.  Implied by
		SYSTEM5.
HASUNSETENV	Define this if your system library has the "unsetenv"
		subroutine.
HASSETSID	Define this if you have the setsid(2) system call.  This
		is implied if your system appears to be POSIX compliant.
HASINITGROUPS	Define this if you have the initgroups(3) routine.
HASSETVBUF	Define this if you have the setvbuf(3) library call.
		If you don't, setlinebuf will be used instead.  This
		defaults on if your compiler defines __STDC__.
HASSETREUID	Define this if you have setreuid(2) ***AND*** root can
		use setreuid to change to an arbitrary user.  This second
		condition is not satisfied on AIX 3.x.  You may find that
		your system has setresuid(2), (for example, on HP-UX) in
		which case you will also have to #define setreuid(r, e)
		to be the appropriate call.  Some systems (such as Solaris)
		have a compatibility routine that doesn't work properly,
		but may have "saved user ids" properly implemented so you
		can ``#define setreuid(r, e) seteuid(e)'' and have it work.
		The important thing is that you have a call that will set
		the effective uid independently of the real or saved uid
		and be able to set the effective uid back again when done.
		There's a test program in ../test/t_setreuid.c that will
		try things on your system.  Setting this improves the
		security, since sendmail doesn't have to read .forward
		and :include: files as root.  There are certain attacks
		that may be unpreventable without this call.
USESETEUID	Define this to 1 if you have a seteuid(2) system call that
		will allow root to set only the effective user id to an
		arbitrary value ***AND*** you have saved user ids.  This is
		preferable to HASSETREUID if these conditions are fulfilled.
		These are the semantics of the to-be-released revision of
		Posix.1.  The test program ../test/t_seteuid.c will try
		this out on your system.  If you define both HASSETREUID
		and USESETEUID, the former is ignored.
HASLSTAT	Define this if you have symbolic links (and thus the
		lstat(2) system call).  This improves security.  Unlike
		most other options, this one is on by default, so you
		need to #undef it in conf.h if you don't have symbolic
		links (these days everyone does).
HASSETRLIMIT	Define this to 1 if you have the setrlimit(2) syscall.
		You can define it to 0 to force it off.  It is assumed
		if you are running a BSD-like system.
HASULIMIT	Define this if you have the ulimit(2) syscall (System V
		style systems).  HASSETRLIMIT overrides, as it is more
		general.
HASWAITPID	Define this if you have the waitpid(2) syscall.
HASGETDTABLESIZE
		Define this if you have the getdtablesize(2) syscall.
HAS_ST_GEN	Define this to 1 if your system has the st_gen field in
		the stat structure (see stat(2)).
USESTRERROR	Define this if you have the libc strerror function (which
		should be declared in <errno.h>), and it should be used
		instead of sys_errlist.
NEEDGETOPT	Define this if you need a reimplementation of getopt(3).
		On some systems, getopt does very odd things if called
		to scan the arguments twice.  This flag will ask sendmail
		to compile in a local version of getopt that works
		properly.
NEEDSTRTOL	Define this if your standard C library does not define
		strtol(3).  This will compile in a local version.
NEEDVPRINTF	Define this if your standard C library does not define
		vprintf(3).  Note that the resulting fake implementation
		is not very elegant and may not even work on some
		architectures.
NEEDFSYNC	Define this if your standard C library does not define
		fsync(2).  This will try to simulate the operation using
		fcntl(2); if that is not available it does nothing, which
		isn't great, but at least it compiles and runs.
HASGETUSERSHELL	Define this to 1 if you have getusershell(3) in your
		standard C library.  If this is not defined, or is defined
		to be 0, sendmail will scan the /etc/shells file (no
		NIS-style support, defaults to /bin/sh and /bin/csh if
		that file does not exist) to get a list of unrestricted
		user shells.  This is used to determine whether users
		are allowed to forward their mail to a program or a file.
NEEDPUTENV	Define this if your system needs am emulation of the
		putenv(3) call.  Define to 1 to implement it in terms
		of setenv(3) or to 2 to do it in terms of primitives.
NOFTRUNCATE	Define this if you don't have the ftruncate(2) syscall.
		If you don't have this system call, there is an unavoidable
		race condition that occurs when creating alias databases.
GIDSET_T	The type of entries in a gidset passed as the second
		argument to getgroups(2).  Historically this has been an
		int, so this is the default, but some systems (such as
		IRIX) pass it as a gid_t, which is an unsigned short.
		This will make a difference, so it is important to get
		this right!  However, it is only an issue if you have
		group sets.
SLEEP_T		The type returned by the system sleep() function.
		Defaults to "unsigned int".  Don't worry about this
		if you don't have compilation problems.
ARBPTR_T	The type of an arbitrary pointer -- defaults to "void *".
		If you are an very old compiler you may need to define
		this to be "char *".
SOCKADDR_LEN_T	The type used for the third parameter to accept(2),
		getsockname(2), and getpeername(2), representing the
		length of a struct sockaddr.  Defaults to int.
SOCKOPT_LEN_T	The type used for the fifth parameter to getsockopt(2)
		and setsockopt(2), representing the length of the option
		buffer.  Defaults to int.
LA_TYPE		The type of load average your kernel supports.  These
		can be one of:
		 LA_ZERO (1) -- it always returns the load average as
			"zero" (and does so on all architectures).
		 LA_INT (2) to read /dev/kmem for the symbol avenrun and
			interpret as a long integer.
		 LA_FLOAT (3) same, but interpret the result as a floating
			point number.
		 LA_SHORT (6) to interpret as a short integer.
		 LA_SUBR (4) if you have the getloadavg(3) routine in your
			system library.
		 LA_MACH (5) to use MACH-style load averages (calls
			processor_set_info()),
		 LA_PROCSTR (7) to read /proc/loadavg and interpret it
			as a string representing a floating-point
			number (Linux-style).
		 LA_READKSYM (8) is an implementation suitable for some
			versions of SVr4 that uses the MIOC_READKSYM ioctl
			call to read /dev/kmem.
		 LA_DGUX (9) is a special implementation for DG/UX that uses
			the dg_sys_info system call.
		 LA_HPUX (10) is an HP-UX specific version that uses the
			pstat_getdynamic system call.
		 LA_IRIX6 (11) is an IRIX 6.x specific version that adapts
			to 32 or 64 bit kernels; it is otherwise very similar
			to LA_INT.
		 LA_KSTAT (12) uses the (Solaris-specific) kstat(3k)
			implementation.
		 LA_DEVSHORT (13) reads a short from a system file (default:
			/dev/table/avenrun) and scales it in the same manner
			as LA_SHORT.
		LA_INT, LA_SHORT, LA_FLOAT, and LA_READKSYM have several
		other parameters that they try to divine: the name of your
		kernel, the name of the variable in the kernel to examine,
		the number of bits of precision in a fixed point load average,
		and so forth.  LA_DEVSHORT uses _PATH_AVENRUN to find the
		device to be read to find the load average.
		In desperation, use LA_ZERO.  The actual code is in
		conf.c -- it can be tweaked if you are brave.
FSHIFT		For LA_INT, LA_SHORT, and LA_READKSYM, this is the number
		of bits of load average after the binary point -- i.e.,
		the number of bits to shift right in order to scale the
		integer to get the true integer load average.  Defaults to 8.
_PATH_UNIX	The path to your kernel.  Needed only for LA_INT, LA_SHORT,
		and LA_FLOAT.  Defaults to "/unix" on System V, "/vmunix"
		everywhere else.
LA_AVENRUN	For LA_INT, LA_SHORT, and LA_FLOAT, the name of the kernel
		variable that holds the load average.  Defaults to "avenrun"
		on System V, "_avenrun" everywhere else.
SFS_TYPE	Encodes how your kernel can locate the amount of free
		space on a disk partition.  This can be set to SFS_NONE
		(0) if you have no way of getting this information,
		SFS_USTAT (1) if you have the ustat(2) system call,
		SFS_4ARGS (2) if you have a four-argument statfs(2)
		system call (and the include file is <sys/statfs.h>),
		SFS_VFS (3), SFS_MOUNT (4), SFS_STATFS (5) if you have
		the two-argument statfs(2) system call with includes in
		<sys/vfs.h>, <sys/mount.h>, or <sys/statfs.h> respectively,
		or SFS_STATVFS (6) if you have the two-argument statvfs(2)
		call.  The default if nothing is defined is SFS_NONE.
SFS_BAVAIL	with SFS_4ARGS you can also set SFS_BAVAIL to the field name
		in the statfs structure that holds the useful information;
		this defaults to f_bavail.
SPT_TYPE	Encodes how your system can display what a process is doing
		on a ps(1) command (SPT stands for Set Process Title).  Can
		be set to:
		SPT_NONE (0) -- Don't try to set the process title at all.
		SPT_REUSEARGV (1) -- Pad out your argv with the information;
			this is the default if none specified.
		SPT_BUILTIN (2) -- The system library has setproctitle.
		SPT_PSTAT (3) -- Use the PSTAT_SETCMD option to pstat(2)
			to set the process title; this is used by HP-UX.
		SPT_PSSTRINGS (4) -- Use the magic PS_STRINGS pointer (4.4BSD).
		SPT_SYSMIPS (5) -- Use sysmips() supported by NEWS-OS 6.
		SPT_SCO (6) -- Write kernel u. area.
		SPT_CHANGEARGV (7) -- Write pointers to our own strings into
			the existing argv vector.
SPT_PADCHAR	Character used to pad the process title; if undefined,
		the space character (0x20) is used.  This is ignored if
		SPT_TYPE != SPT_REUSEARGV
ERRLIST_PREDEFINED
		If set, assumes that some header file defines sys_errlist.
		This may be needed if you get type conflicts on this
		variable -- otherwise don't worry about it.
WAITUNION	The wait(2) routine takes a "union wait" argument instead
		of an integer argument.  This is for compatibility with
		old versions of BSD.
SCANF		You can set this to extend the F command to accept a
		scanf string -- this gives you a primitive parser for
		class definitions -- BUT it can make you vulnerable to
		core dumps if the target file is poorly formed.
SYSLOG_BUFSIZE	You can define this to be the size of the buffer that
		syslog accepts.  If it is not defined, it assumes a
		1024-byte buffer.  If the buffer is very small (under
		256 bytes) the log message format changes -- each
		e-mail message will log many more messages, since it
		will log each piece of information as a separate line
		in syslog.
BROKEN_RES_SEARCH
		On Ultrix (and maybe other systems?) if you use the
		res_search routine with an unknown host name, it returns
		-1 but sets h_errno to 0 instead of HOST_NOT_FOUND.  If
		you set this, sendmail considers 0 to be the same as
		HOST_NOT_FOUND.
NAMELISTMASK	If defined, values returned by nlist(3) are masked
		against this value before use -- a common value is
		0x7fffffff to strip off the top bit.
BSD4_4_SOCKADDR	If defined, socket addresses have an sa_len field that
		defines the length of this address.
SAFENFSPATHCONF	Set this to 1 if and only if you have verified that a
		pathconf(2) call with _PC_CHOWN_RESTRICTED argument on an
		NFS filesystem where the underlying system allows users to
		give away files to other users returns <= 0.  Be sure you
		try both on NFS V2 and V3.  Some systems assume that their
		local policy apply to NFS servers -- this is a bad
		assumption!  The test/t_pathconf.c program will try this
		for you -- you have to run it in a directory that is
		mounted from a server that allows file giveaway.
SIOCGIFCONF_IS_BROKEN
		Set this if your system has an SIOCGIFCONF ioctl defined,
		but it doesn't behave the same way as "most" systems (BSD,
		Solaris, SunOS, HP-UX, etc.)
SIOCGIFNUM_IS_BROKEN
		Set this if your system has an SIOCGIFNUM ioctl defined,
		but it doesn't behave the same way as "most" systems
		(Solaris, HP-UX).
NEED_PERCENTQ	Set this if your system doesn't support the printf
		format strings %lld or %llu.  If this is set, %qd and
		%qu are used instead.



+-----------------------+
| COMPILE-TIME FEATURES |
+-----------------------+

There are a bunch of features that you can decide to compile in, such
as selecting various database packages and special protocol support.
Several are assumed based on other compilation flags -- if you want to
"un-assume" something, you probably need to edit conf.h.  Compilation
flags that add support for special features include:

NDBM		Include support for "new" DBM library for aliases and maps.
		Normally defined in the Makefile.
NEWDB		Include support for Berkeley DB package (hash & btree)
		for aliases and maps.  Normally defined in the Makefile.
		If the version of NEWDB you have is the old one that does
		not include the "fd" call (this call was added in version
		1.5 of the Berkeley DB code), you must upgrade to the
		current version of Berkeley DB.
NIS		Define this to get NIS (YP) support for aliases and maps.
		Normally defined in the Makefile.
NISPLUS		Define this to get NIS+ support for aliases and maps.
		Normally defined in the Makefile.
HESIOD		Define this to get Hesiod support for aliases and maps.
		Normally defined in the Makefile.
NETINFO		Define this to get NeXT NetInfo support for aliases and maps.
		Normally defined in the Makefile.
USERDB		Define this to 1 to include support for the User Information
		Database.  Implied by NEWDB or HESIOD.  You can use
		-DUSERDB=0 to explicitly turn it off.
IDENTPROTO	Define this as 1 to get IDENT (RFC 1413) protocol support.
		This is assumed unless you are running on Ultrix or
		HP-UX, both of which have a problem in the UDP
		implementation.  You can define it to be 0 to explicitly
		turn off IDENT protocol support.  If defined off, the code
		is actually still compiled in, but it defaults off; you
		can turn it on by setting the IDENT timeout to 30s in the
		configuration file.
IP_SRCROUTE	Define this to 1 to get IP source routing information
		displayed in the Received: header.  This is assumed on
		most systems, but some (e.g., Ultrix) apparently have a
		broken version of getsockopt that doesn't properly
		support the IP_OPTIONS call.  You probably want this if
		your OS can cope with it.  Symptoms of failure will be that
		it won't compile properly (that is, no support for fetching
		IP_OPTIONs), or it compiles but source-routed TCP connections
		either refuse to open or open and hang for no apparent reason.
		Ultrix and AIX3 are known to fail this way.
LOG		Set this to get syslog(3) support.  Defined by default
		in conf.h.  You want this if at all possible.
NETINET		Set this to get TCP/IP support.  Defined by default
		in conf.h.  You probably want this.
NETISO		Define this to get ISO networking support.
NETUNIX		Define this to get Unix domain networking support.  Defined
		by default.  A few bizarre systems (SCO, ISC, Altos) don't
		support this networking domain.
SMTP		Define this to get the SMTP code.  Implied by NETINET
		or NETISO.
NAMED_BIND	If non-zero, include DNS (name daemon) support, including
		MX support.  The specs say you must use this if you run
		SMTP.  You don't have to be running a name server daemon
		on your machine to need this -- any use of the DNS resolver,
		including remote access to another machine, requires this
		option.  Defined by default in conf.h.  Define it to zero
		ONLY on machines that do not use DNS in any way.
QUEUE		Define this to get queueing code.  Implied by NETINET
		or NETISO; required by SMTP.  This gives you other good
		stuff -- it should be on.
DAEMON		Define this to get general network support.  Implied by
		NETINET or NETISO.  Defined by default in conf.h.  You
		almost certainly want it on.
MATCHGECOS	Permit fuzzy matching of user names against the full
		name (GECOS) field in the /etc/passwd file.  This should
		probably be on, since you can disable it from the config
		file if you want to.  Defined by default in conf.h.
MIME8TO7	If non-zero, include 8 to 7 bit MIME conversions.  This
		also controls advertisement of 8BITMIME in the ESMTP
		startup dialogue.
MIME7TO8	If non-zero, include 7 to 8 bit MIME conversions.
HES_GETMAILHOST	Define this to 1 if you are using Hesiod with the
		hes_getmailhost() routine.  This is included with the MIT
		Hesiod distribution, but not with the DEC Hesiod distribution.
XDEBUG		Do additional internal checking.  These don't cost too
		much; you might as well leave this on.
TCPWRAPPERS	Turns on support for the TCP wrappers library (-lwrap).
		See below for further information.
SECUREWARE	Enable calls to the SecureWare luid enabling/changing routines.
		SecureWare is a C2 security package added to several UNIX's
		(notably ConvexOS) to get a C2 Secure system.  This
		option causes mail delivery to be done with the luid of the
		recipient.
SHARE_V1	Support for the fair share scheduler, version 1.  Setting to
		1 causes final delivery to be done using the recipients
		resource limitations.  So far as I know, this is only
		supported on ConvexOS.


+---------------------+
| DNS/RESOLVER ISSUES |
+---------------------+

Many systems have old versions of the resolver library.  At a minimum,
you should be running BIND 4.8.3; older versions may compile, but they
have known bugs that should give you pause.

Common problems in old versions include "undefined" errors for
dn_skipname.

Some people have had a problem with BIND 4.9; it uses some routines
that it expects to be externally defined such as strerror().  It may
help to link with "-l44bsd" to solve this problem.  This has apparently
been fixed in later versions of BIND, starting around 4.9.3.  In other
words, if you use 4.9.0 through 4.9.2, you need -l44bsd; for earlier or
later versions, you do not.

!PLEASE! be sure to link with the same version of the resolver as
the header files you used -- some people have used the 4.9 headers
and linked with BIND 4.8 or vice versa, and it doesn't work.
Unfortunately, it doesn't fail in an obvious way -- things just
subtly don't work.

WILDCARD MX RECORDS ARE A BAD IDEA!  The only situation in which they
work reliably is if you have two versions of DNS, one in the real world
which has a wildcard pointing to your firewall, and a completely
different version of the database internally that does not include
wildcard MX records that match your domain.  ANYTHING ELSE WILL GIVE
YOU HEADACHES!


+-------------------------------------+
| OPERATING SYSTEM AND COMPILE QUIRKS |
+-------------------------------------+

GCC problems
	*****************************************************************
	**  IMPORTANT:  DO NOT USE OPTIMIZATION (``-O'') IF YOU ARE    **
	**  RUNNING GCC 2.4.x or 2.5.x.  THERE IS A BUG IN THE GCC     **
	**  OPTIMIZER THAT CAUSES SENDMAIL COMPILES TO FAIL MISERABLY. **
	*****************************************************************

	Jim Wilson of Cygnus believes he has found the problem -- it will
	probably be fixed in GCC 2.5.6 -- but until this is verified, be
	very suspicious of gcc -O.  This problem is reported to have been
	fixed in gcc 2.6.

	A bug in gcc 2.5.5 caused problems compiling sendmail 8.6.5 with
	optimization on a Sparc.  If you are using gcc 2.5.5, youi should
	upgrade to the latest version of gcc.

	Apparently GCC 2.7.0 on the Pentium processor has optimization
	problems.  I recommend against using -O on that architecture.  This
	has been seen on FreeBSD 2.0.5 RELEASE.

	Solaris 2.X users should use version 2.7.2.3 over 2.7.2.

	We have been told there are problems with gcc 2.8.0.  If you are
	using this version, you should upgrade to 2.8.1 or later.

GDBM	GDBM does not work with sendmail 8.8 because the additional
	security checks and file locking cause problems.  Unfortunately,
	gdbm does not provide a compile flag in its version of ndbm.h so
	the code can adapt.  Until the GDBM authors can fix these problems,
	GDBM will not be supported.  Please use Berkeley DB instead.

Configuration file location
	Up to 8.6, sendmail tried to find the sendmail.cf file in the same
	place as the vendors had put it, even when this was obviously
	stupid.  As of 8.7, sendmail ALWAYS looks for /etc/sendmail.cf.
	Beginning with 8.10, sendmail will use /etc/mail/sendmail.cf.
	You can get sendmail to use the stupid vendor .cf location by
	adding -DUSE_VENDOR_CF_PATH during compilation, but this may break
	support programs and scripts that need to find sendmail.cf.  You
	are STRONGLY urged to use symbolic links if you want to use the
	vendor location rather than changing the location in the sendmail
	binary.

SunOS 4.x (Solaris 1.x)
	You may have to use -lresolv on SunOS.  However, beware that
	this links in a new version of gethostbyname that does not
	understand NIS, so you must have all of your hosts in DNS.

	Some people have reported problems with the SunOS version of
	-lresolv and/or in.named, and suggest that you get a newer
	version.  The symptoms are delays when you connect to the
	SMTP server on a SunOS machine or having your domain added to
	addresses inappropriately.  There is a version of BIND
	version 4.9 on gatekeeper.DEC.COM in pub/BSD/bind/4.9.

	There is substantial disagreement about whether you can make
	this work with resolv+, which allows you to specify a search-path
	of services.  Some people report that it works fine, others
	claim it doesn't work at all (including causing sendmail to
	drop core when it tries to do multiple resolv+ lookups for a
	single job).  I haven't tried resolv+, as we use DNS exclusively.

	Should you want to try resolv+, it is on ftp.uu.net in
	/networking/ip/dns.

	Apparently getservbyname() can fail under moderate to high
	load under some circumstances.  This will exhibit itself as
	the message ``554 makeconnection: service "smtp" unknown''.
	The problem has been traced to one or more blank lines in
	/etc/services on the NIS server machine.  Delete these
	and it should work.  This info is thanks to Brian Bartholomew
	<bb@math.ufl.edu> of I-Kinetics, Inc.

SunOS 4.0.2 (Sun 386i)
	Date: Fri, 25 Aug 1995 11:13:58 +0200 (MET DST)
	From: teus@oce.nl

	Sendmail 8.7.Beta.12 compiles and runs nearly out of the box with the
	following changes:
	* Don't use /usr/5bin in your PATH, but make /usr/5bin/uname
	  available as "uname" command.
	* Use the defines "-DBSD4_3 -DNAMED_BIND=0" in
	  BuildTools/OS/SunOS.4.0, which is selected via the "uname" command.
	I recommend to make available the db-library on the system first
	(and change the Makefile to use this library).
	Note that the sendmail.cf and aliases files are found in /etc.

SunOS 4.1.3, 4.1.3_U1
	Sendmail causes crashes on SunOS 4.1.3 and 4.1.3_U1.  According
	to Sun bug number 1077939:

	If an application does a getsockopt() on a SOCK_STREAM (TCP) socket
	after the other side of the connection has sent a TCP RESET for
	the stream, the kernel gets a Bus Trap in the tcp_ctloutput() or
	ip_ctloutput() routine.

	For 4.1.3, this is fixed in patch 100584-08, available on the
	Sunsolve 2.7.1 or later CDs.  For 4.1.3_U1, this was fixed in patch
	101790-01 (SunOS 4.1.3_U1: TCP socket and reset problems), later
	obsoleted by patch 102010-05.

	Sun patch 100584-08 is not currently publicly available on their
	ftp site but a user has reported it can be found at other sites
	using a web search engine.

Solaris 2.x (SunOS 5.x)
	To compile for Solaris, the Makefile built by Build must
	include a SOLARIS definition which reflects the Solaris version
	(i.e. -DSOLARIS=20400 for 2.4 or -DSOLARIS=20501 for 2.5.1).
	If you are using gcc, make sure -I/usr/include is not used (or
	it might complain about TopFrame).  If you are using Sun's cc,
	make sure /opt/SUNWspro/bin/cc is used instead of /usr/ucb/cc
	(or it might complain about tm_zone).

	To the best of my knowledge, Solaris does not have the
	gethostbyname problem described above.  However, it does
	have another one:

	From a correspondent:

	   For solaris 2.2, I have

		hosts:      files dns

	   in /etc/nsswitch.conf and /etc/hosts has to have the fully
	   qualified host name. I think "files" has to be before "dns"
	   in /etc/nsswitch.conf during bootup.

	From another correspondent:

	   When running sendmail under Solaris, the gethostbyname()
	   hack in conf.c which should perform proper canonicalization
	   of host names could fail.  Result: the host name is not
	   canonicalized despite the hack, and you'll have to define $j
	   and $m in sendmail.cf somewhere.

	   The reason could be that /etc/nsswitch.conf is improperly
	   configured (at least from sendmail's point of view).  For
	   example, the line

		hosts:      files nisplus dns

	   will make gethostbyname() look in /etc/hosts first, then ask
	   nisplus, then dns.  However, if /etc/hosts does not contain
	   the full canonicalized hostname, then no amount of
	   gethostbyname()s will work.

	   Solution (or rather, a workaround): Ask nisplus first, then
	   dns, then local files:

		hosts:      nisplus dns [NOTFOUND=return] files

	The Solaris "syslog" function is apparently limited to something
	about 90 characters because of a kernel limitation.  If you have
	source code, you can probably up this number.  You can get patches
	that fix this problem: the patch ids are:

		Solaris 2.1	100834
		Solaris 2.2	100999
		Solaris 2.3	101318

	Be sure you have the appropriate patch installed or you won't
	see system logging.

Solaris 2.4 (SunOS 5.4)
	If you include /usr/lib at the end of your LD_LIBRARY_PATH you run
	the risk of getting the wrong libraries under some circumstances.
	This is because of a new feature in Solaris 2.4, described by
	Rod.Evans@Eng.Sun.COM:

	>> Prior to SunOS 5.4, any LD_LIBRARY_PATH setting was ignored by the
	>> runtime linker if the application was setxid (secure), thus your
	>> applications search path would be:
	>>
	>>	/usr/local/lib	LD_LIBRARY_PATH component - IGNORED
	>>	/usr/lib	LD_LIBRARY_PATH component - IGNORED
	>>	/usr/local/lib	RPATH - honored
	>>	/usr/lib	RPATH - honored
	>>
	>> the effect is that path 3 would be the first used, and this would
	>> satisfy your resolv.so lookup.
	>>
	>> In SunOS 5.4 we made the LD_LIBRARY_PATH a little more flexible.
	>> People who developed setxid applications wanted to be able to alter
	>> the library search path to some degree to allow for their own
	>> testing and debugging mechanisms.  It was decided that the only
	>> secure way to do this was to allow a `trusted' path to be used in
	>> LD_LIBRARY_PATH.  The only trusted directory we presently define
	>> is /usr/lib.  Thus a setuid root developer could play with some
	>> alternative shared object implementations and place them in
	>> /usr/lib (being root we assume they'ed have access to write in this
	>> directory).  This change was made as part of 1155380 - after a
	>> *huge* amount of discussion regarding the security aspect of things.
	>>
	>> So, in SunOS 5.4 your applications search path would be:
	>>
	>>	/usr/local/lib	from LD_LIBRARY_PATH - IGNORED (untrustworthy)
	>>	/usr/lib	from LD_LIBRARY_PATH - honored (trustworthy)
	>>	/usr/local/lib	from RPATH - honored
	>>	/usr/lib	from RPATH - honored
	>>
	>> here, path 2 would be the first used.

Solaris 2.6 (SunOS 5.6)
	If you built sendmail 8.8.1 through 8.8.4 inclusive on a Solaris 2.5
	system, that binary will not run on Solaris 2.6, due to problems with
	incompatible snprintf(3s) calls.  This problem is fixed in sendmail
	8.8.5.

Solaris 2.5.1 (SunOS 5.5.1) and 2.6 (SunOS 5.6)
	Apparently Solaris 2.5.1 patch 103663-01 installs a new
	/usr/include/resolv.h file that defines the __P macro without
	checking to see if it is already defined.  This new resolv.h is also
	included in the Solaris 2.6 distribution. This causes compile
	warnings such as:

	   In file included from daemon.c:51:
	   /usr/include/resolv.h:208: warning: `__P' redefined
	   cdefs.h:58: warning: this is the location of the previous definition

	These warnings can be safely ignored or you can create a resolv.h
	file in the obj.SunOS.5.5.1.* or obj.SunOS.5.6.* directory that reads:

	   #undef __P
	   #include "/usr/include/resolv.h"

	Sun is aware of the problem (Sun bug ID 4081053) and it will be fixed
	in Solaris 2.7.

Ultrix
	By default, the IDENT protocol is turned off on Ultrix.  If you
	are running Ultrix 4.4 or later, or if you have included patch
	CXO-8919 for Ultrix 4.2 or 4.3 to fix the TCP problem, you can turn
	IDENT on in the configuration file by setting the "ident" timeout
	to 30 seconds.

Digital UNIX (formerly DEC OSF/1)
	If you are compiling on OSF/1 (DEC Alpha), you must use
	-L/usr/shlib (otherwise it core dumps on startup).  You may also
	need -mld to get the nlist() function, although some versions
	apparently don't need this.
	
	Also, the enclosed makefile removed /usr/sbin/smtpd; if you need
	it, just create the link to the sendmail binary.

	On DEC OSF/1 3.2 or earlier, the MatchGECOS option doesn't work
	properly due to a bug in the getpw* routines.  If you want to use
	this, use -DDEC_OSF_BROKEN_GETPWENT=1.  The problem is fixed in 3.2C.

	Digital's mail delivery agent, /bin/mail (aka /bin/binmail), will
	only preserve the envelope sender in the "From " header if
	DefaultUserID is set to daemon.  Setting this to mailnull will
	cause all mail to have the header "From mailnull ...".  To use
	a different DefaultUserID, you will need to use a different mail
	delivery agent (such as mail.local found in the sendmail
	distribution).

	On Digital UNIX 4.0 and later, Berkeley DB 1.85 is included with the
	operating system and already has the ndbm.o module removed.  However,
	Digital has modified the original Berkeley DB db.h include file.
	This results in the following warning while compiling map.c and udb.c:

	cc: Warning: /usr/include/db.h, line 74: The redefinition of the macro
	 "__signed" conflicts with a current definition because the replacement
	 lists differ.  The redefinition is now in effect.
	#define __signed        signed
	------------------------^

	This warning can be ignored.

	Digital UNIX's linker checks /usr/ccs/lib/ before /usr/lib/.
	If you have installed a new version of BIND in /usr/include
	and /usr/lib, you will experience difficulties as Digital ships
	libresolv.a in /usr/ccs/lib/ as well.  Be sure to replace both
	copies of libresolv.a.

IRIX
	The header files on SGI IRIX are completely prototyped, and as
	a result you can sometimes get some warning messages during
	compilation.  These can be ignored.  There are two errors in
	deliver only if you are using gcc, both of the form ``warning:
	passing arg N of `execve' from incompatible pointer type''.
	Also, if you compile with -DNIS, you will get a complaint
	about a declaration of struct dom_binding in a prototype
	when compiling map.c; this is not important because the
	function being prototyped is not used in that file.

	In order to compile sendmail you will have had to install
	the developers' option in order to get the necessary include
	files.

	If you compile with -lmalloc (the fast memory allocator), you may
	get warning messages such as the following:

	   ld32: WARNING 85: definition of _calloc in /usr/lib32/libmalloc.so
		preempts that definition in /usr/lib32/mips3/libc.so.
	   ld32: WARNING 85: definition of _malloc in /usr/lib32/libmalloc.so
		preempts that definition in /usr/lib32/mips3/libc.so.
	   ld32: WARNING 85: definition of _realloc in /usr/lib32/libmalloc.so
		preempts that definition in /usr/lib32/mips3/libc.so.
	   ld32: WARNING 85: definition of _free in /usr/lib32/libmalloc.so
		preempts that definition in /usr/lib32/mips3/libc.so.
	   ld32: WARNING 85: definition of _cfree in /usr/lib32/libmalloc.so
		preempts that definition in /usr/lib32/mips3/libc.so.

	These are unavoidable and innocuous -- just ignore them.

	According to Dave Sill <de5@ornl.gov>, there is a version of the
	Berkeley DB library patched to run on Irix 6.2 available from
	http://reality.sgi.com/ariel/freeware/#db .

IRIX 6.x
	It is important that on IRIX 6.x you give used ABI in command
	line of Build, otherwise configuration script does not work
	correctly, e.g.,

		sh Build -E ABI=-n32

	If you are using XFS filesystem, avoid using ABI=-32 if possible.

NeXT or NEXTSTEP
	NEXTSTEP 3.3 and earlier ship with the old DBM library.  Also,
	Berkeley DB does not currently run on NEXTSTEP.

	If you are compiling on NEXTSTEP, you will have to create an
	empty file "unistd.h" and create a file "dirent.h" containing:

		#include <sys/dir.h>
		#define dirent	direct

	(BuildTools/OS/NeXT should try to do both of these for you.)

	Apparently, there is a bug in getservbyname on Nextstep 3.0
	that causes it to fail under some circumstances with the
	message "SYSERR: service "smtp" unknown" logged.  You should
	be able to work around this by including the line:

		OOPort=25

	in your .cf file.

	You may have to use -DNeXT.

BSDI (BSD/386) 1.0, NetBSD 0.9, FreeBSD 1.0
	The "m4" from BSDI won't handle the config files properly.
	I haven't had a chance to test this myself.

	The M4 shipped in FreeBSD and NetBSD 0.9 don't handle the config
	files properly. One must use either GNU m4 1.1 or the PD-M4
	recently posted in comp.os.386bsd.bugs (and maybe others).
	NetBSD-current includes the PD-M4 (as stated in the NetBSD file
	CHANGES).
	
	FreeBSD 1.0 RELEASE has uname(2) now. Use -DUSEUNAME in order to
	use it (look into BuildTools/OS/FreeBSD). NetBSD-current may have
	it too but it has not been verified.

	The latest version of Berkeley DB uses a different naming
	scheme than the version that is supplied with your release.  This
	means you will be able to use the current version of Berkeley DB
	with sendmail as long you use the new db.h when compiling
	sendmail and link it against the new libdb.a.  You should probably
	keep the original db.h in /usr/include and the new db.h in
	/usr/local/include.

4.3BSD
	If you are running a "virgin" version of 4.3BSD, you'll have
	a very old resolver and be missing some header files.  The
	header files are simple -- create empty versions and everything
	will work fine.  For the resolver you should really port a new
	version (4.8.3 or later) of the resolver; 4.9 is available on
	gatekeeper.DEC.COM in pub/BSD/bind/4.9.  If you are really
	determined to continue to use your old, buggy version (or as
	a shortcut to get sendmail working -- I'm sure you have the
	best intentions to port a modern version of BIND), you can
	copy ../contrib/oldbind.compat.c into src and add
	oldbind.compat.o to OBJADD in the Makefile.

A/UX
	Date: Tue, 12 Oct 1993 18:28:28 -0400 (EDT)
	From: "Eric C. Hagberg" <hagberg@med.cornell.edu>
	Subject: Fix for A/UX ndbm

	I guess this isn't really a sendmail bug, however, it is something
	that A/UX users should be aware of when compiling sendmail 8.6.

	Apparently, the calls that sendmail is using to the ndbm routines
	in A/UX 3.0.x contain calls to "broken" routines, in that the
	aliases database will break when it gets "just a little big"
	(sorry I don't have exact numbers here, but it broke somewhere
	around 20-25 aliases for me.), making all aliases non-functional
	after exceeding this point.

	What I did was to get the gnu-dbm-1.6 package, compile it, and
	then re-compile sendmail with "-lgdbm", "-DNDBM", and using the
	ndbm.h header file that comes with the gnu-package. This makes
	things behave properly.
	  [NOTE: see comment above about GDBM]

	I suppose porting the New Berkeley DB package is another route,
	however, I made a quick attempt at it, and found it difficult
	(not easy at least); the gnu-dbm package "configured" and
	compiled easily.

	  [NOTE: Berkeley DB version 2.X runs on A/UX and can be used for
	  database maps.]

SCO Unix
	From: Thomas Essebier <tom@stallion.oz.au>
	Organisation:  Stallion Technologies Pty Ltd.

	It will probably help those who are trying to configure sendmail 8.6.9
	to know that if they are on SCO, they had better set
		OI-dnsrch
	or they will core dump as soon as they try to use the resolver.
	ie. although SCO has _res.dnsrch defined, and is kinda BIND 4.8.3, it
	does not inititialise it, nor does it understand 'search' in
	/etc/named.boot.
		- sigh -

	According to SCO, the m4 which ships with UnixWare 2.1.2 is broken.	
	We recommend installing GNU m4 before attempting to build sendmail.

DG/UX
	Doug Anderson <dlander@afterlife.ncsc.mil> has successfully run
	V8 on the DG/UX 5.4.2 and 5.4R3.x platforms under heavy usage.
	Originally, the DG /bin/mail program wasn't compatible with
	the V8 sendmail, since the DG /bin/mail requires the environment
	variable "_FORCE_MAIL_LOCAL_=yes" be set.  Version 8.7 now includes
	this in the environment before invoking the local mailer.  Some
	have used procmail to avoid this problem in the past.  It works
	but some have experienced file locking problems with their DG/UX
	ports of procmail.

Apollo DomainOS
	If you are compiling on Apollo, you will have to create an empty
	file "unistd.h" (for DomainOS 10.3 and earlier) and create a file
	"dirent.h" containing:

		#include <sys/dir.h>
		#define dirent	direct

	(BuildTools/OS/DomainOS will attempt to do both of these for you.)

HP-UX 8.00
	Date: Mon, 24 Jan 1994 13:25:45 +0200
	From: Kimmo Suominen <Kimmo.Suominen@lut.fi>
	Subject: 8.6.5 w/ HP-UX 8.00 on s300

	Just compiled and fought with sendmail 8.6.5 on a HP9000/360 (ie. a
	series 300 machine) running HP-UX 8.00.

	I was getting segmentation fault when delivering to a local user.
	With debugging I saw it was faulting when doing _free@libc... *sigh*
	It seems the new implementation of malloc on s300 is buggy as of 8.0,
	so I tried out the one in -lmalloc (malloc(3X)).  With that it seems
	to work just dandy.

	When linking, you will get the following error:

	ld: multiply defined symbol _freespace in file /usr/lib/libmalloc.a

	but you can just ignore it.  You might want to add this info to the
	README file for the future...

Linux
	Something broke between versions 0.99.13 and 0.99.14 of Linux:
	the flock() system call gives errors.  If you are running .14,
	you must not use flock.  You can do this with -DHASFLOCK=0.

	Around the inclusion of bind-4.9.3 & Linux libc-4.6.20, the
	initialization of the _res structure changed.  If /etc/hosts.conf
	was configured as "hosts, bind" the resolver code could return
	"Name server failure" errors.  This is supposedly fixed in
	later versions of libc (>= 4.6.29?), and later versions of
	sendmail (> 8.6.10) try to work around the problem.

	Some older versions (< 4.6.20?) of the libc/include files conflict
	with sendmail's version of cdefs.h.  Deleting sendmail's version
	on those systems should be non-harmful, and new versions don't care.

	Sendmail assumes that libc has snprintf, which has been true since
	libc 4.7.0.  If you are running an older version, you will need to
	use -DHASSNPRINTF=0 in the Makefile.  If may be able to use -lbsd
	(which includes snprintf) instead of turning this off on versions
	of libc between 4.4.4 and 4.7.0 (snprintf improves security, so
	you want to use this if at all possible).

	NOTE ON LINUX & BIND:  By default, the Makefile generated for Linux
	includes header files in /usr/local/include and libraries in
	/usr/local/lib.  If you've installed BIND on your system, the header
	files typically end up in the search path and you need to add
	"-lresolv" to the LIBS line in your Makefile.  Really old versions
	may need to include "-l44bsd" as well (particularly if the link phase
	complains about missing strcasecmp, strncasecmp or strpbrk).
	Complaints about an undefined reference to `__dn_skipname' in
	domain.o are a sure sign that you need to add -lresolv to LIBS.
	Newer versions of Linux are basically threaded BIND, so you may or
	may not see complaints if you accidentally mix BIND
	headers/libraries with virginal libc.  If you have BIND headers in
	/usr/local/include (resolv.h, etc) you *should* be adding -lresolv
	to LIBS.  Data structures may change and you'd be asking for a
	core dump.

AIX 4.2
	The AIX m4 implements a different mechanism for ifdef which is
	inconsistent with other versions of m4.  Therefore, it will not
	work properly with the sendmail Build architecture or m4
	configuration method.  To work around this problem, please use
	GNU m4 from ftp://ftp.gnu.org/pub/gnu/.

AIX 3.x
	This version of sendmail does not support MB, MG, and MR resource
	records, which are supported by AIX sendmail.

	Several people have reported that the IBM-supplied named returns
	fairly random results -- the named should be replaced.  It is not
	necessary to replace the resolver, which will simplify installation.
	A new BIND resolver can be found at http://www.isc.org/isc/.

AIX 3.1.x
	The supplied load average code only works correctly for AIX 3.2.x.
	For 3.1, use -DLA_TYPE=LA_SUBR and get the latest ``monitor''
	package by Jussi Maki <jmaki@hut.fi> from ftp.funet.fi in the
	directory pub/unix/AIX/rs6000/monitor-1.12.tar.Z; use the loadavgd
	daemon, and the getloadavg subroutine supplied with that package.
	If you don't care about load average throttling, just turn off
	load average checking using -DLA_TYPE=LA_ZERO.

AIX 2.2.1
	Date: Mon Dec  4 14:14:56 CST 1995
	From: Mark Whetzel <markw@antimatr.houston.tx.us>
	Subject: Porting sendmail 8.7.2 to AIX V2 on the RT.
	
	This version of sendmail does not support MB, MG, and MR resource
	records, which are supported by AIX sendmail.

	AIX V2 on the RT does not have 'paths.h'.  Create a null
	file in the 'obj' directory to remove this compile error.

	A patch file is needed to get the BSD 'db' library to compile
	for AIX/RT.  I have sent the necessary updates to the author,
	but they may not be immediately available.
	  [NOTE: Berkeley DB version 2.X runs on AIX/RT.]

	The original AIX/RT resolver libraries are very old, and you
	should get the latest BIND to replace it.  The 4.8.3 version
	has been tested, but 4.9.x is out and should work.

	To make the load average code work correctly requires an
	external routine, as the kernel does not maintain system
	load averages, similar to AIX V3.1.x.  A reverse port of the
	older 1.05 'monitor' load average daemon code written by
	Jussi Maki that will work on AIX V2 for the RT is available
	by E-mail to Mark Whetzel  <markw@antimatr.houston.tx.us>.
	That code depends on an external daemon to collect system
	load information, and the external routine 'getloadavg',
	that will return that information.  The 'LA_SUBR' define
	will handle this for AIX V2 on the RT.

	Note: You will have to change BuildTools/OS/AIX.2 to correctly
	point to the locatons of the updated BIND source tree and
	the location of the 'newdb' tree and library location.
	You will also have to change BuildTools/OS/AIX.2 to know
	about the location of the 'getloadavg' routine if you use
	the LA_SUBR define.

	
	Manual pages will format correctly if given the mandoc macros
	and used with nroff.  I have not tried groff.

RISC/os
	RISC/os from MIPS is a merged AT&T/Berkeley system.  When you
	compile on that platform you will get duplicate definitions
	on many files.  You can ignore these.

System V Release 4 Based Systems
	There is a single BuildTools OS that is intended for all SVR4-based
	systems (built from BuildTools/OS/SVR4).  It defines __svr4__,
	which is predefined by some compilers.  If your compiler already
	defines this compile variable, you can delete the definition from
	the generated Makefile or create a BuildTools/Site/site.config.m4
	file.

	It's been tested on Dell Issue 2.2.

DELL SVR4
	Date:      Mon, 06 Dec 1993 10:42:29 EST
	From: "Kimmo Suominen" <kim@grendel.lut.fi>
	Message-ID: <2d0352f9.lento29@lento29.UUCP>
	To: eric@cs.berkeley.edu
	Cc: sendmail@cs.berkeley.edu
	Subject:   Notes for DELL SVR4

	Eric,

	Here are some notes for compiling Sendmail 8.6.4 on DELL SVR4.  I ran
	across these things when helping out some people who contacted me by
	e-mail.

	1) Use gcc 2.4.5 (or later?).  Dell distributes gcc 2.1 with their
	   Issue 2.2 Unix.  It is too old, and gives you problems with
	   clock.c, because sigset_t won't get defined in <sys/signal.h>.
	   This is due to a problematic protection rule in there, and is
	   fixed with gcc 2.4.5.

	2) If you don't use the new Berkeley DB (-DNEWDB), then you need
	   to add "-lc -lucb" to the libraries to link with.  This is because
	   the -ldbm distributed by Dell needs the bcopy, bcmp and bzero
	   functions.  It is important that you specify both libraries in
	   the given order to be sure you only get the BSTRING functions
	   from the UCB library (and not the signal routines etc.).

	3) Don't leave out "-lelf" even if compiling with "-lc -lucb".
	   The UCB library also has another copy of the nlist routines,
	   but we do want the ones from "-lelf".

	If anyone needs a compiled gcc 2.4.5 and/or a ported DB library, they
	can use anonymous ftp to fetch them from lut.fi in the /kim directory.
	They are copies of what I use on grendel.lut.fi, and offering them
	does not imply that I would also support them.  I have sent the DB
	port for SVR4 back to Keith Bostic for inclusion in the official
	distribution, but I haven't heard anything from him as of today.

	- gcc-2.4.5-svr4.tar.gz	(gcc 2.4.5 and the corresponding libg++)
	- db-1.72.tar.gz	(with source, objects and a installed copy)

	Cheers
	+ Kim
	--
	 *  Kimmo.Suominen@lut.fi  *  SysVr4 enthusiast at GRENDEL.LUT.FI  *
	*    KIM@FINFILES.BITNET   *  Postmaster and Hostmaster at LUT.FI   *
	 *    + 358 200 865 718    *  Unix area moderator at NIC.FUNET.FI  *

ConvexOS 10.1 and below
	In order to use the name server, you must create the file
	/etc/use_nameserver.  If this file does not exist, the call
	to res_init() will fail and you will have absolutely no
	access to DNS, including MX records.

Amdahl UTS 2.1.5
	In order to get UTS to work, you will have to port BIND 4.9.
	The vendor's BIND is reported to be ``totally inadequate.''
	See sendmail/contrib/AmdahlUTS.patch for the patches necessary
	to get BIND 4.9 compiled for UTS.

UnixWare
	According to Alexander Kolbasov <sasha@unitech.gamma.ru>,
	the m4 on UnixWare 2.0 (still in Beta) will core dump on the
	config files.  GNU m4 and the m4 from UnixWare 1.x both work.

	According to Larry Rosenman <ler@lerami.lerctr.org>:

		UnixWare 2.1.[23]'s m4 chokes (not obviously) when
		processing the 8.9.0 cf files. 
 
		I had a LOCAL_RULE_0 that wound up AFTER the
		SBasic_check_rcpt rules using the SCO supplied M4.
		GNU M4 works fine. 

UNICOS 8.0.3.4
	Some people have reported that the -O flag on UNICOS can cause
	problems.  You may want to turn this off if you have problems
	running sendmail.  Reported by Jerry G. DeLapp <jgd@acl.lanl.gov>.

GNU getopt
	I'm told that GNU getopt has a problem in that it gets confused
	by the double call.  Use the version in conf.c instead.

BIND 4.9.2 and Ultrix
	If you are running on Ultrix, be sure you read conf/Info.Ultrix
	in the BIND distribution very carefully -- there is information
	in there that you need to know in order to avoid errors of the
	form:

		/lib/libc.a(gethostent.o): sethostent: multiply defined
		/lib/libc.a(gethostent.o): endhostent: multiply defined
		/lib/libc.a(gethostent.o): gethostbyname: multiply defined
		/lib/libc.a(gethostent.o): gethostbyaddr: multiply defined

	during the link stage.

strtoul
	Some compilers (notably gcc) claim to be ANSI C but do not
	include the ANSI-required routine "strtoul".  If your compiler
	has this problem, you will get an error in srvrsmtp.c on the
	code:

	  # ifdef defined(__STDC__) && !defined(BROKEN_ANSI_LIBRARY)
			e->e_msgsize = strtoul(vp, (char **) NULL, 10);
	  # else
			e->e_msgsize = strtol(vp, (char **) NULL, 10);
	  # endif

	You can use -DBROKEN_ANSI_LIBRARY to get around this problem.

Listproc 6.0c
	Date: 23 Sep 1995 23:56:07 GMT
	Message-ID: <95925101334.~INN-AUMa00187.comp-news@dl.ac.uk>
	From: alansz@mellers1.psych.berkeley.edu (Alan Schwartz)
	Subject: Listproc 6.0c + Sendmail 8.7 [Helpful hint]

	Just upgraded to sendmail 8.7, and discovered that listproc 6.0c
	breaks, because it, by default, sends a blank "HELO" rather than
	a "HELO hostname" when using the 'system' or 'telnet' mailmethod.

	The fix is to include -DZMAILER in the compilation, which will
	cause it to use "HELO hostname" (which Z-mail apparently requires
	as well. :)

LDAP
	LDAP was provided by Booker Bense <bbense+ldap@stanford.edu> of
	Stanford University.  From Booker:

	  - The patch attached to this message implements an Ldap map class.
	    Currently we are using this at stanford to support campus-wide
	    email addressing. More information can be found at
	    http://www.stanford.edu/~bbense/Inst.html.

	  - Currently we are using the ldap map as follows:

		Kluser ldapx
		    -h"localhost borax.stanford.edu borate.stanford.edu boron.stanford.edu"
		    -k"mailacceptinggeneralid=%s" -v maildrop

	    and in Rule set S5

		# Now attempt to lookup in luser (ldap map)
		R< $L > $+		$: < $L > $( luser $1 $)
		R< $*  > $+ @ $+	$: < $3 > $2		Rewrite if forward

	  - The map definition supports most of the standard Map args plus most
	    of the command line options of ldapsearch. The software is currently
	    limited to only accepting the first entry returned. It expects that
	    the map defines an ldap filter that returns at most 1 valid entry.
	    It requires the ldap and lber libraries from the Umich Ldap3.2
	    release.

	    The software has been in production on Solaris.2.5.1 at Stanford
	    for over 2 years.

TCP Wrappers
	If you are using -DTCPWRAPPERS to get TCP Wrappers support you will
	also need to install libwrap.a and modify your site.config.m4 file
	or the generated Makefile to include -lwrap in the LIBS line
	(make sure that INCDIRS and LIBDIRS point to where the tcpd.h and
	libwrap.a can be found).

	TCP Wrappers is available on ftp.win.tue.nl in /pub/security;
	grab tcp_wrappers_<VER>.tar.gz (where <VER> is the highest
	numbered version).

	If you have alternate MX sites for your site, be sure that all of
	your MX sites reject the same set of hosts.  If not, a bad guy whom
	you reject will connect to your site, fail, and move on to the next
	MX site, which will accept the mail for you and forward it on to you.

Regular Expressions (MAP_REGEX)
	If sendmail linking fails with:

		undefined reference to 'regcomp'

	or sendmail gives an error about a regular expression with:

		pattern-compile-error: : Operation not applicable 

	Your libc does not include a running version of POSIX-regex. Use
	librx or regex.o from the GNU Free Software Foundation,  
	ftp://ftp.gnu.org/pub/gnu/rx-?.?.tar.gz or 
	ftp://ftp.gnu.org/pub/gnu/regex-?.?.tar.gz. 
	You can also use the regex-lib by Henry Spencer, 
	ftp://ftp.funet.fi/pub/languages/C/spencer/regex.shar.gz  
	Make sure, your compiler reads regex.h from the distribution,  
	not from /usr/include, otherwise sendmail will dump a core. 


+--------------+
| MANUAL PAGES |
+--------------+

The manual pages have been written against the -mandoc macros
instead of the -man macros.  The latest version of groff has them
included.  You can also get a copy from FTP.UU.NET in the directory
/systems/unix/bsd-sources/share/tmac.  groff is available from
ftp.gnu.org in the /pub/gnu directory.


+-----------------+
| DEBUGGING HOOKS |
+-----------------+

As of 8.6.5, sendmail daemons will catch a SIGUSR1 signal and log
some debugging output (logged at LOG_DEBUG severity).  The
information dumped is:

 * The value of the $j macro.
 * A warning if $j is not in the set $=w.
 * A list of the open file descriptors.
 * The contents of the connection cache.
 * If ruleset 89 is defined, it is evaluated and the results printed.

This allows you to get information regarding the runtime state of the
daemon on the fly.  This should not be done too frequently, since
the process of rewriting may lose memory which will not be recovered.
Also, ruleset 89 may call non-reentrant routines, so there is a small
non-zero probability that this will cause other problems.  It is
really only for debugging serious problems.

A typical formulation of ruleset 89 would be:

	R$*		$@ $>0 some test address


+-----------------------------+
| DESCRIPTION OF SOURCE FILES |
+-----------------------------+

The following list describes the files in this directory:

Makefile.m4	A template for constructing a makefile based on the
		information in the BuildTools directory.
README		This file.
TRACEFLAGS	My own personal list of the trace flags -- not guaranteed
		to be particularly up to date.
alias.c		Does name aliasing in all forms.
arpadate.c	A subroutine which creates ARPANET standard dates.
clock.c		Routines to implement real-time oriented functions
		in sendmail -- e.g., timeouts.
collect.c	The routine that actually reads the mail into a temp
		file.  It also does a certain amount of parsing of
		the header, etc.
conf.c		The configuration file.  This contains information
		that is presumed to be quite static and non-
		controversial, or code compiled in for efficiency
		reasons.  Most of the configuration is in sendmail.cf.
conf.h		Configuration that must be known everywhere.
convtime.c	A routine to sanely process times.
daemon.c	Routines to implement daemon mode.  This version is
		specifically for Berkeley 4.1 IPC.
deliver.c	Routines to deliver mail.
domain.c	Routines that interface with DNS (the Domain Name
		System).
err.c		Routines to print error messages.
envelope.c	Routines to manipulate the envelope structure.
headers.c	Routines to process message headers.
macro.c		The macro expander.  This is used internally to
		insert information from the configuration file.
main.c		The main routine to sendmail.  This file also
		contains some miscellaneous routines.
map.c		Support for database maps.
mci.c		Routines that handle mail connection information caching.
mime.c		MIME conversion routines.
parseaddr.c	The routines which do address parsing.
queue.c		Routines to implement message queueing.
readcf.c	The routine that reads the configuration file and
		translates it to internal form.
recipient.c	Routines that manipulate the recipient list.
safefile.c	Routines to do careful checking of file modes and permissions
		when opening or creating files.
savemail.c	Routines which save the letter on processing errors.
sendmail.h	Main header file for sendmail.
snprintf.c	Routines to manipulate strings but prevent buffer overflows.
srvrsmtp.c	Routines to implement server SMTP.
stab.c		Routines to manage the symbol table.
stats.c		Routines to collect and post the statistics.
sysexits.c	List of error messages associated with error codes
		in sysexits.h.
trace.c		The trace package.  These routines allow setting and
		testing of trace flags with a high granularity.
udb.c		The user database interface module.
usersmtp.c	Routines to implement user SMTP.
util.c		Some general purpose routines used by sendmail.
version.c	The version number and information about this
		version of sendmail.  Theoretically, this gets
		modified on every change.

Eric Allman

(Version 8.209, last update 10/6/1998 17:10:21)