main.c

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· C语言 代码 · 共 1,090 行 · 第 1/2 页

#ifndef lint
static	char	*sccsid = "@(#)main.c	4.1	(ULTRIX)	7/2/90";
#endif lint

/************************************************************************
 *									*
 *			Copyright (c) 1987 by				*
 *		Digital Equipment Corporation, Maynard, MA		*
 *			All rights reserved.				*
 *									*
 *   This software is furnished under a license and may be used and	*
 *   copied  only  in accordance with the terms of such license and	*
 *   with the  inclusion  of  the  above  copyright  notice.   This	*
 *   software  or  any  other copies thereof may not be provided or	*
 *   otherwise made available to any other person.  No title to and	*
 *   ownership of the software is hereby transferred.			*
 *									*
 *   This software is  derived  from  software  received  from  the	*
 *   University    of   California,   Berkeley,   and   from   Bell	*
 *   Laboratories.  Use, duplication, or disclosure is  subject  to	*
 *   restrictions  under  license  agreements  with  University  of	*
 *   California and with AT&T.						*
 *									*
 *   The information in this software is subject to change  without	*
 *   notice  and should not be construed as a commitment by Digital	*
 *   Equipment Corporation.						*
 *									*
 *   Digital assumes no responsibility for the use  or  reliability	*
 *   of its software on equipment which is not supplied by Digital.	*
 *									*
 ************************************************************************/

# define  _DEFINE
# include <signal.h>
# include <sgtty.h>
# include "sendmail.h"

# ifdef lint
char	edata, end;
# endif lint

/*
**  SENDMAIL -- Post mail to a set of destinations.
**
**	This is the basic mail router.  All user mail programs should
**	call this routine to actually deliver mail.  Sendmail in
**	turn calls a bunch of mail servers that do the real work of
**	delivering the mail.
**
**	Sendmail is driven by tables read in from /usr/lib/sendmail.cf
**	(read by readcf.c).  Some more static configuration info,
**	including some code that you may want to tailor for your
**	installation, is in conf.c.  You may also want to touch
**	daemon.c (if you have some other IPC mechanism), acct.c
**	(to change your accounting), names.c (to adjust the name
**	server mechanism).
**
**	Usage:
**		/usr/lib/sendmail [flags] addr ...
**
**		See the associated documentation for details.
**
**	Author:
**		Eric Allman, UCB/INGRES (until 10/81)
**			     Britton-Lee, Inc., purveyors of fine
**				database computers (from 11/81)
**		The support of the INGRES Project and Britton-Lee is
**			gratefully acknowledged.  Britton-Lee in
**			particular had absolutely nothing to gain from
**			my involvement in this project.
*/





int		NextMailer;	/* "free" index into Mailer struct */
char		*FullName;	/* sender's full name */
ENVELOPE	BlankEnvelope;	/* a "blank" envelope */
ENVELOPE	MainEnvelope;	/* the envelope around the basic letter */
ADDRESS		NullAddress =	/* a null address */
		{ "", "", "" };

/*
**  Pointers for setproctitle.
**	This allows "ps" listings to give more useful information.
**	These must be kept out of BSS for frozen configuration files
**		to work.
*/

# ifdef SETPROCTITLE
char		**Argv = NULL;		/* pointer to argument vector */
char		*LastArgv = NULL;	/* end of argv */
# endif SETPROCTITLE

#ifdef DAEMON
#ifndef SMTP
ERROR %%%%   Cannot have daemon mode without SMTP   %%%% ERROR
#endif SMTP
#endif DAEMON



main(argc, argv, envp)
	int argc;
	char **argv;
	char **envp;
{
	register char *p;
	char **av;
	extern int finis();
	extern char Version[];
	char *from;
	typedef int (*fnptr)();
	STAB *st;
	register int i;
	bool readconfig = TRUE;
	bool queuemode = FALSE;		/* process queue requests */
	bool nothaw;
	static bool reenter = FALSE;
	char jbuf[30];			/* holds MyHostName */
	extern bool safefile();
	extern time_t convtime();
	extern putheader(), putbody();
	extern ENVELOPE *newenvelope();
	extern intsig();
	extern char **myhostname();
	extern char *arpadate();
	extern char **environ;

	/*
	**  Check to see if we reentered.
	**	This would normally happen if e_putheader or e_putbody
	**	were NULL when invoked.
	*/

	if (reenter)
	{
		syserr("main: reentered!");
		abort();
	}
	reenter = TRUE;

	/*
	**  Be sure we have enough file descriptors.
	*/

	for (i = 3; i < 50; i++)
		(void) close(i);
	errno = 0;

	/*
	**  Set default values for variables.
	**	These cannot be in initialized data space.
	*/

	setdefaults();

	/* set up the blank envelope */
	BlankEnvelope.e_puthdr = putheader;
	BlankEnvelope.e_putbody = putbody;
	BlankEnvelope.e_xfp = NULL;
	STRUCTCOPY(NullAddress, BlankEnvelope.e_from);
	CurEnv = &BlankEnvelope;
	STRUCTCOPY(NullAddress, MainEnvelope.e_from);

	/*
	**  Do a quick prescan of the argument list.
	**	We do this to find out if we can potentially thaw the
	**	configuration file.  If not, we do the thaw now so that
	**	the argument processing applies to this run rather than
	**	to the run that froze the configuration.
	*/

	argv[argc] = NULL;
	av = argv;
	nothaw = FALSE;
	while ((p = *++av) != NULL)
	{
		if (strncmp(p, "-C", 2) == 0)
		{
			ConfFile = &p[2];
			if (ConfFile[0] == '\0')
				ConfFile = "sendmail.cf";
			(void) setgid(getrgid());
			(void) setuid(getruid());
			nothaw = TRUE;
		}
		else if (strncmp(p, "-bz", 3) == 0)
			nothaw = TRUE;
# ifdef DEBUG
		else if (strncmp(p, "-d", 2) == 0)
		{
			tTsetup(tTdvect, sizeof tTdvect, "0-99.1");
			tTflag(&p[2]);
			setbuf(stdout, (char *) NULL);
			printf("Version %s\n", Version);
		}
# endif DEBUG
	}
	if (!nothaw)
		readconfig = !thaw(FreezeFile);

	/* reset the environment after the thaw */
	for (i = 0; i < MAXUSERENVIRON && envp[i] != NULL; i++)
		UserEnviron[i] = newstr(envp[i]);
	UserEnviron[i] = NULL;
	environ = UserEnviron;

# ifdef SETPROCTITLE
	/*
	**  Save start and extent of argv for setproctitle.
	*/

	Argv = argv;
	if (i > 0)
		LastArgv = envp[i - 1] + strlen(envp[i - 1]);
	else
		LastArgv = argv[argc - 1] + strlen(argv[argc - 1]);
# endif SETPROCTITLE

	/*
	**  Now do basic initialization
	*/

	InChannel = stdin;
	OutChannel = stdout;
	if (signal(SIGINT, SIG_IGN) != SIG_IGN)
		(void) signal(SIGINT, intsig);
	if (signal(SIGHUP, SIG_IGN) != SIG_IGN)
		(void) signal(SIGHUP, intsig);
	(void) signal(SIGTERM, intsig);
	(void) signal(SIGPIPE, SIG_IGN);
	OldUmask = umask(0);
	OpMode = MD_DELIVER;
	MotherPid = getpid();
# ifndef V6
	FullName = getenv("NAME");
# endif V6

	/* Get Yellow Pages domain (if any)
	 */
	if (!getdomainname(default_domain,YPMAXDOMAIN) && 
		   (strlen(default_domain) > 0)) 

			YPdomain = default_domain;
		else
			/* If we can't get a domain name for YP,
			 * assume YP not up and therefor, no YP maps.
			 */
			YPdomain = NULL;

#ifdef LOG
# ifndef BSD4_3
	openlog("sendmail", LOG_PID|LOG_CONS|LOG_NDELAY, LOG_DAEMON);
# else	BSD4_3
	openlog("sendmail",LOG_PID|LOG_TIME);
# endif BSD4_3
#endif LOG
	errno = 0;
	from = NULL;

	if (readconfig)
	{
		/* initialize some macros, etc. */
		initmacros();

		/* hostname */
		av = myhostname(jbuf, sizeof jbuf);
		if (jbuf[0] != '\0')
		{
		int i=0;
			/* Strip trailing domain spec so that $w macro
			 * is unqualified host name for config file
			 * rules parsing.
			 */
                        while (jbuf[i] != '\0' && jbuf[i] != '.')
                        {
                                i++;
                        }
                        jbuf[i] = '\0';

#ifdef DEBUG
			if (tTd(0, 4))
				printf("canonical name: %s\n", jbuf);
#endif DEBUG
			p = newstr(jbuf);
			define('w', p, CurEnv);
			setclass('w', p);
		}
		while (av != NULL && *av != NULL)
		{
#ifdef DEBUG
			if (tTd(0, 4))
				printf("\ta.k.a.: %s\n", *av);
#endif DEBUG
			setclass('w', *av++);
		}

		/* version */
		define('v', Version, CurEnv);
	}

	/* current time */
	define('b', arpadate((char *) NULL), CurEnv);

	/*
	** Crack argv.
	*/

	av = argv;
	p = rindex(*av, '/');
	if (p++ == NULL)
		p = *av;
	if (strcmp(p, "newaliases") == 0)
		OpMode = MD_INITALIAS;
	else if (strcmp(p, "mailq") == 0)
		OpMode = MD_PRINT;
	else if (strcmp(p, "smtpd") == 0)
		OpMode = MD_DAEMON;
	while ((p = *++av) != NULL && p[0] == '-')
	{
		switch (p[1])
		{
		  case 'b':	/* operations mode */
			switch (p[2])
			{
			  case MD_DAEMON:
# ifndef DAEMON
				syserr("Daemon mode not implemented");
				break;
# endif DAEMON
			  case MD_SMTP:
# ifndef SMTP
				syserr("I don't speak SMTP");
				break;
# endif SMTP
			  case MD_ARPAFTP:
			  case MD_DELIVER:
			  case MD_VERIFY:
			  case MD_TEST:
			  case MD_INITALIAS:
			  case MD_PRINT:
			  case MD_FREEZE:
				OpMode = p[2];
				break;

			  default:
				syserr("Invalid operation mode %c", p[2]);
				break;
			}
			break;

		  case 'C':	/* select configuration file (already done) */
			break;

# ifdef DEBUG
		  case 'd':	/* debugging -- redo in case frozen */
			tTsetup(tTdvect, sizeof tTdvect, "0-99.1");
			tTflag(&p[2]);
			setbuf(stdout, (char *) NULL);
			break;
# endif DEBUG

		  case 'f':	/* from address */
		  case 'r':	/* obsolete -f flag */
			p += 2;
			if (*p == '\0' && ((p = *++av) == NULL || *p == '-'))
			{
				p = *++av;
				if (p == NULL || *p == '-')
				{
					syserr("No \"from\" person");
					av--;
					break;
				}
			}
			if (from != NULL)
			{
				syserr("More than one \"from\" person");
				break;
			}
			from = newstr(p);
			break;

		  case 'F':	/* set full name */
			p += 2;
			if (*p == '\0' && ((p = *++av) == NULL || *p == '-'))
			{
				syserr("Bad -F flag");
				av--;
				break;
			}
			FullName = newstr(p);
			break;

		  case 'h':	/* hop count */
			p += 2;
			if (*p == '\0' && ((p = *++av) == NULL || !isdigit(*p)))
			{
				syserr("Bad hop count (%s)", p);
				av--;
				break;
			}
			CurEnv->e_hopcount = atoi(p);
			break;
		
		  case 'n':	/* don't alias */
			NoAlias = TRUE;
			break;

		  case 'o':	/* set option */
			setoption(p[2], &p[3], FALSE, TRUE);
			break;

		  case 'q':	/* run queue files at intervals */
# ifdef QUEUE
			queuemode = TRUE;
			QueueIntvl = convtime(&p[2]);
# else QUEUE
			syserr("I don't know about queues");
# endif QUEUE
			break;

		  case 't':	/* read recipients from message */
			GrabTo = TRUE;
			break;

			/* compatibility flags */
		  case 'c':	/* connect to non-local mailers */
		  case 'e':	/* error message disposition */
		  case 'i':	/* don't let dot stop me */
		  case 'm':	/* send to me too */
		  case 'T':	/* set timeout interval */
		  case 'v':	/* give blow-by-blow description */
			setoption(p[1], &p[2], FALSE, TRUE);
			break;

		  case 's':	/* save From lines in headers */
			setoption('f', &p[2], FALSE, TRUE);
			break;

# ifdef DBM
		  case 'I':	/* initialize alias DBM file */
			OpMode = MD_INITALIAS;
			break;
# endif DBM
		}
	}

	/*
	**  Do basic initialization.
	**	Read system control file.
	**	Extract special fields for local use.
	*/

	if (OpMode == MD_FREEZE || readconfig)
		readcf(ConfFile);

	switch (OpMode)
	{
	  case MD_FREEZE:
		/* this is critical to avoid forgeries of the frozen config */
		(void) setgid(getgid());
		(void) setuid(getuid());

		/* freeze the configuration */
		freeze(FreezeFile);
		exit(EX_OK);

	  case MD_INITALIAS:
		Verbose = TRUE;
		break;
	}

	/* do heuristic mode adjustment */
	if (Verbose)
	{
		/* turn off noconnect option */
		setoption('c', "F", TRUE, FALSE);

		/* turn on interactive delivery */
		setoption('d', "", TRUE, FALSE);
	}

	/* our name for SMTP codes */
	expand("\001j", jbuf, &jbuf[sizeof jbuf - 1], CurEnv);
	MyHostName = jbuf;

	/* the indices of local and program mailers */
	st = stab("local", ST_MAILER, ST_FIND);
	if (st == NULL)
		syserr("No local mailer defined");
	else
		LocalMailer = st->s_mailer;
	st = stab("prog", ST_MAILER, ST_FIND);
	if (st == NULL)
		syserr("No prog mailer defined");
	else
		ProgMailer = st->s_mailer;

	/* operate in queue directory */
	if (chdir(QueueDir) < 0)
	{
		syserr("cannot chdir(%s)", QueueDir);
		exit(EX_SOFTWARE);
	}

	/*
	**  Do operation-mode-dependent initialization.
	*/

	switch (OpMode)
	{
	  case MD_PRINT:
		/* print the queue */
#ifdef QUEUE
		dropenvelope(CurEnv);
		printqueue();
		exit(EX_OK);
#else QUEUE
		usrerr("No queue to print");
		finis();
#endif QUEUE

	  case MD_INITALIAS:
		/* initialize alias database */
		initaliases(AliasFile, TRUE);
		exit(EX_OK);

	  case MD_DAEMON:
		/* don't open alias database -- done in srvrsmtp */
		break;

	  default:
		/* open the alias database */
		initaliases(AliasFile, FALSE);
		break;
	}

# ifdef DEBUG
	if (tTd(0, 15))
	{
		/* print configuration table (or at least part of it) */
		printrules();