srvrsmtp.c

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· C语言 代码 · 共 743 行 · 第 1/2 页

#ifndef lint
static	char	*sccsid = "@(#)srvrsmtp.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.	*
 *									*
 ************************************************************************/

# include <errno.h>
# include "sendmail.h"
# include <signal.h>

# ifndef SMTP
# ifndef lint
static char	SccsId[] = "@(#)srvrsmtp.c @(#)srvrsmtp.c	1.1 (ULTRIX) 7/17/87 (no SMTP)";
# endif not lint
# else SMTP

# ifndef lint
static char	SccsId[] = "@(#)srvrsmtp.c @(#)srvrsmtp.c	1.1 (ULTRIX) 7/17/87 (with SMTP)";
# endif not lint

/*
**  SMTP -- run the SMTP protocol.
**
**	Parameters:
**		none.
**
**	Returns:
**		never.
**
**	Side Effects:
**		Reads commands from the input channel and processes
**			them.
*/

struct cmd
{
	char	*cmdname;	/* command name */
	int	cmdcode;	/* internal code, see below */
};

/* values for cmdcode */
# define CMDERROR	0	/* bad command */
# define CMDMAIL	1	/* mail -- designate sender */
# define CMDRCPT	2	/* rcpt -- designate recipient */
# define CMDDATA	3	/* data -- send message text */
# define CMDRSET	4	/* rset -- reset state */
# define CMDVRFY	5	/* vrfy -- verify address */
# define CMDHELP	6	/* help -- give usage info */
# define CMDNOOP	7	/* noop -- do nothing */
# define CMDQUIT	8	/* quit -- close connection and die */
# define CMDHELO	9	/* helo -- be polite */
# define CMDDBGQSHOW	10	/* showq -- show send queue (DEBUG) */
# define CMDDBGDEBUG	11	/* debug -- set debug mode */
# define CMDVERB	12	/* verb -- go into verbose mode */
# define CMDDBGKILL	13	/* kill -- kill sendmail */
# define CMDDBGWIZ	14	/* wiz -- become a wizard */
# define CMDONEX	15	/* onex -- sending one transaction only */

static struct cmd	CmdTab[] =
{
	"mail",		CMDMAIL,
	"rcpt",		CMDRCPT,
	"data",		CMDDATA,
	"rset",		CMDRSET,
	"vrfy",		CMDVRFY,
	"expn",		CMDVRFY,
	"help",		CMDHELP,
	"noop",		CMDNOOP,
	"quit",		CMDQUIT,
	"helo",		CMDHELO,
	"verb",		CMDVERB,
	"onex",		CMDONEX,
# ifdef DEBUG
	"showq",	CMDDBGQSHOW,
# ifdef notdef
	/* We don't want this debug switch accessable via SMTP */
	"debug",	CMDDBGDEBUG,
# endif
# endif DEBUG
# ifdef WIZ
	"kill",		CMDDBGKILL,
# endif WIZ
	"wiz",		CMDDBGWIZ,
	NULL,		CMDERROR,
};

# ifdef WIZ
bool	IsWiz = FALSE;			/* set if we are a wizard */
# endif WIZ
char	*WizWord;			/* the wizard word to compare against */
bool	InChild = FALSE;		/* true if running in a subprocess */
bool	OneXact = FALSE;		/* one xaction only this run */
bool	InRCPT = FALSE;			/* are we in RCPT To: command? */

#define EX_QUIT		22		/* special code for QUIT command */

smtp()
{
	register char *p;
	register struct cmd *c;
	char *cmd;
	extern char *skipword();
	extern bool sameword();
	bool hasmail;			/* mail command received */
	bool aliaserror;		/* bad address in the alias file? */
	auto ADDRESS *vrfyqueue;
	ADDRESS *a;
	char inp[MAXLINE];
	char cmdbuf[100];
	extern char Version[];
	extern tick();
	extern bool iswiz();
	extern char *arpadate();
	extern char *macvalue();
	extern char *aliaslookup();
	extern ADDRESS *recipient();
	extern ENVELOPE BlankEnvelope;
	extern ENVELOPE *newenvelope();

	hasmail = aliaserror = FALSE;
	if (OutChannel != stdout)
	{
		/* arrange for debugging output to go to remote host */
		(void) close(1);
		(void) dup(fileno(OutChannel));
	}
	settime();
	if (RealHostName != NULL)
	{
		CurHostName = RealHostName;
		setproctitle("srvrsmtp %s", CurHostName);
	}
	else
	{
		/* this must be us!! */
		CurHostName = MyHostName;
	}
	expand("\001e", inp, &inp[sizeof inp], CurEnv);
	message("220", inp);
	SmtpPhase = "startup";
	for (;;)
	{
		/* arrange for backout */
		if (setjmp(TopFrame) > 0 && InChild)
			finis();
		QuickAbort = FALSE;
		HoldErrs = FALSE;

		/* setup for the read */
		CurEnv->e_to = NULL;
		Errors = 0;
		(void) fflush(stdout);

		/* read the input line */
		p = sfgets(inp, sizeof inp, InChannel);

		/* handle errors */
		if (p == NULL)
		{
			/* end of file, just die */
			message("421", "%s Lost input channel to %s",
				MyHostName, CurHostName);
			finis();
		}

		/* clean up end of line */
		fixcrlf(inp, TRUE);

		/* echo command to transcript */
		if (CurEnv->e_xfp != NULL)
			fprintf(CurEnv->e_xfp, "<<< %s\n", inp);

		/* break off command */
		for (p = inp; isspace(*p); p++)
			continue;
		cmd = p;
		for (cmd = cmdbuf; *p != '\0' && !isspace(*p); )
			*cmd++ = *p++;
		*cmd = '\0';

		/* throw away leading whitespace */
		while (isspace(*p))
			p++;

		/* decode command */
		for (c = CmdTab; c->cmdname != NULL; c++)
		{
			if (sameword(c->cmdname, cmdbuf))
				break;
		}

		/* process command */
		switch (c->cmdcode)
		{
		  case CMDHELO:		/* hello -- introduce yourself */
			SmtpPhase = "HELO";
			setproctitle("%s: %s", CurHostName, inp);
			if (sameword(p, MyHostName))
			{
				/* connected to an echo server */
				message("553", "%s I refuse to talk to myself",
					MyHostName);
				break;
			}
			if (RealHostName != NULL && !sameword(p, RealHostName))
			{
				char hostbuf[MAXNAME];

				(void) sprintf(hostbuf, "%s (%s)", p, RealHostName);
				define('s', newstr(hostbuf), CurEnv);
			}
			else
				define('s', newstr(p), CurEnv);
			message("250", "%s Hello %s, pleased to meet you",
				MyHostName, p);
			break;

		  case CMDMAIL:		/* mail -- designate sender */
			SmtpPhase = "MAIL";

			/* force a sending host even if no HELO given */
			if (RealHostName != NULL && macvalue('s', CurEnv) == NULL)
				define('s', RealHostName, CurEnv);

			/* check for validity of this command */
			if (hasmail)
			{
				message("503", "Sender already specified");
				break;
			}
			if (InChild)
			{
				syserr("Nested MAIL command");
				exit(0);
			}

			/* fork a subprocess to process this command */
			if (runinchild("SMTP-MAIL") > 0)
				break;
			initsys();
			setproctitle("%s %s: %s", CurEnv->e_id,
				CurHostName, inp);

			/* child -- go do the processing */
			p = skipword(p, "from");
			if (p == NULL)
				break;
			setsender(p);
			if (Errors == 0)
			{
				message("250", "Sender ok");
				hasmail = TRUE;
			}
			else if (InChild)
				finis();
			break;

		  case CMDRCPT:		/* rcpt -- designate recipient */
			SmtpPhase = "RCPT";
			setproctitle("%s %s: %s", CurEnv->e_id,
				CurHostName, inp);
			if (setjmp(TopFrame) > 0)
			{
				CurEnv->e_flags &= ~EF_FATALERRS;
				break;
			}
			QuickAbort = TRUE;
			p = skipword(p, "to");
			if (p == NULL)
				break;
			a = parseaddr(p, (ADDRESS *) NULL, 1, '\0');
			if (a == NULL)
				break;
			a->q_flags |= QPRIMARY;

			InRCPT = TRUE;
			a = recipient(a, &CurEnv->e_sendqueue);
			InRCPT = FALSE;

			/*
			 * The gratuitous twiddling of the fatal error
			 * bit below is to detect bad addresses in the alias
			 * file and to notify local owner- addresses while
			 * trying not to send the remote user a (duplicate)
			 * error if his mailer is capable of that.
			 */
			CurEnv->e_to = p;
			if (aliaslookup(a->q_user))
			{
				/*
				 * If the rcpt to: line is in the alias file
				 * tell the sender it's ok.  It may expand to
				 * an invalid address, but we lie to the sender
				 * and say it's ok.  This permits us to honor
				 * the owner- alias and to deliver to valid
				 * addressees on the alias list, if any.
				 *
				 * If there was an error, remember it
				 * since the error bit can get cleared
				 * on the next rcpt to: and since we
				 * want to report the error later on.
				 */
				message("250", "Recipient ok");
				if (bitset(EF_FATALERRS, CurEnv->e_flags))
					aliaserror = TRUE;
			}
			else
			{
				if (!bitset(QBADADDR, a->q_flags))
					message("250", "Recipient ok");
				else
				{
					/*
					 * This will cause the sending mailer
					 * to notify the user.  We clear the
					 * error bit so we don't notify him.
					 */
					message("550", "Addressee unknown");
					CurEnv->e_flags &= ~EF_FATALERRS;
				}
			}
			CurEnv->e_to = NULL;
			break;

		  case CMDDATA:		/* data -- text of mail */
			SmtpPhase = "DATA";
			if (!hasmail)
			{
				message("503", "Need MAIL command");
				break;
			}
			else if (CurEnv->e_nrcpts <= 0)
			{
				message("503", "Need RCPT (recipient)");
				break;
			}

			/* collect the text of the message */
			SmtpPhase = "collect";
			setproctitle("%s %s: %s", CurEnv->e_id,
				CurHostName, inp);
			collect(TRUE);
			if (Errors != 0)
				break;

			/*