xref: /csrg-svn/usr.sbin/sendmail/src/READ_ME (revision 63937)

# Copyright (c) 1983 Eric P. Allman
# Copyright (c) 1988 The Regents of the University of California.
# All rights reserved.
#
# %sccs.include.redist.sh%
#
#	@(#)READ_ME	8.5 (Berkeley) 07/19/93
#

This directory contains the source files for sendmail.

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

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

The Makefile is for the new Berkeley make, available from ftp.uu.net
in the directory /systems/unix/bsd-sources/usr.bin/make.  There is
also a Makefile.dist which is much less clever, but works on the old
traditional make.  You can use this using:

	make -f Makefile.dist

There are a couple of other Makefiles for other systems -- these are
the ones that I use, they have "Berkeley quirks" in them, and I don't
guarantee that they will work in your environment.  To make it worse,
some are for the new Berkeley make, and some are for the old make.
I provide them for information only.  Still, they may help you get
started.  They have names like "Makefile.HPUX".

Whereever 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 availble, requiring the following compilation flags in the
Makefile:

SOLARIS		Define this if you are running Solaris 2.0 or higher.
__NeXT__	Define this if you are on a NeXT box.  (This one may
		be pre-defined for you.)
_AIX3		Define this if you are IBM AIX 3.x.

If you are a system that sendmail has already been ported to, you
probably won't have to touch these.  But if you are porting, you may
have to tweak the following compilation flags in order to get
it to compile and link properly:

UNSETENV	Define this if your system library does NOT include the
		"unsetenv" subroutine.
SYSTEM5		Adjust for System V.
LOCKF		Set this if you do not have the flock system call -- it
		will revert to System V file locking.  There are some
		semantic gotchas, so flock is preferred.  Implied by
		SYSTEM5.
SYS5TZ		Use System V-style time zones.  If not set, the TZ
		environment variable is ignored.  Implied by SYSTEM5.
HASUNAME	Set if you have the "uname" system call.  Implied by
		SYSTEM5.
HASSTATFS	Define this if you have the statfs(2) system call.  It's
		not a disaster to get this wrong -- but you do lose the
		queue free space code.
HASUSTAT	Define this if you have the ustat(2) system call.  It's
		not a disaster to get this wrong -- but you do lose the
		queue free space code.
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.
		The important thing is that you have a call that will set
		the effective uid independently of the real or saved uid.
		Setting this improves the security somewhat, since
		sendmail doesn't have to read .forward and :include: files
		as root.
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.
LA_TYPE		The type of load average your kernel supports.  These
		can be LA_SUBR (4) if you have the getloadavg(3) routine,
		LA_FLOAT (3) if you read kmem and interpret the value
		as a floating point number, LA_INT (2) to interpret as
		an integer.  These last two 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.  In desparation, use LA_ZERO -- it always returns
		the load average as "zero" (and does so on all architectures).
		The actual code is in conf.c -- it can be tweaked if you
		are brave.

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.
NEWDB		Include support for Berkeley "db" package (hash & btree)
		for aliases and maps.
NIS		Define this to get NIS (YP) support for aliases and maps.
YPCOMPAT	Define this to force building of DBM versions of alias
		files even if you have NEWDB defined; this will only
		occur on NIS master machines.  It is independent of NIS.
USERDB		Include support for the User Information Database.  Implied
		by NEWDB conf.h.
IDENTPROTO	Define this 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.
MIME		Include support for MIME-encapsulated error messages.
FROZENCONFIG	Define this to get support for frozen configuration
		files.  Frozen configurations make sense if your I/O system
		is fast relative to your processor.  At this point this
		is NOT recommended.
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.
SMTP		Define this to get the SMTP code.  Implied by NETINET
		or NETISO.
NAMED_BIND	Define this to get DNS (name daemon) support, including
		MX support.  The specs you must use this if you run
		SMTP.  Defined by default in conf.h.
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.
SETPROCTITLE	Try to set the string printed by "ps" to something
		informative about what sendmail is doing.  Defined by
		default in conf.h.

If you are compiling on SunOS and want to use frozen configuration
files, you must use -Bstatic -- if you do not, frozen configuration
files fail in bizarre ways and you will open up several security holes.

If you are compiling on OSF/1 (DEC Alpha), you must use -lmld.

If you are compiling on NeXT, you will have to create an empty file
"unistd.h".

If you use both -DNDBM and -DNEWDB, you must delete the module ndbm.o
from libdb.a and delete the file "ndbm.h" from the files that get
installed (that is, use the OLD ndbm.h, not the new ndbm.h).  This
compatibility module maps ndbm calls into DB calls, and breaks things
rather badly.

You probably want to look over the compilation options in conf.h
before you compile.  These are intended to be per-site information.

The following list describes the files in this directory:

Makefile	The makefile used here; this version only works with
		the new Berkeley make.
Makefile.dist	A trimmed down version of the makefile that works with
		the old make.
READ_ME		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.
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.
savemail.c	Routines which save the letter on processing errors.
sendmail.h	Main header file for sendmail.
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 8.5, last update 07/19/93 20:50:04)