alias.c

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· C语言 代码 · 共 786 行 · 第 1/2 页

#ifndef lint
static	char	*sccsid = "@(#)alias.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 <pwd.h>
# include <sys/types.h>
# include <sys/stat.h>
# include <signal.h>
# include <errno.h>
# include "sendmail.h"
# ifdef FLOCK
# include <sys/file.h>
# endif FLOCK
#include <sys/svcinfo.h>
#include <hesiod.h>

# ifndef DBM
# ifndef lint
static char	SccsId[] = "@(#)alias.c @(#)alias.c	1.2 (ULTRIX) 7/20/87 (no DBM)";
# endif not lint
# else DBM

# ifndef lint
static char	SccsId[] = "@(#)alias.c @(#)alias.c	1.2 (ULTRIX) 7/20/87 (with DBM)";
# endif not lint
# endif not DBM

/*
**  ALIAS -- Compute aliases.
**
**	Scans the alias file for an alias for the given address.
**	If found, it arranges to deliver to the alias list instead.
**	Uses libdbm database if -DDBM.
**
**	Parameters:
**		a -- address to alias.
**		sendq -- a pointer to the head of the send queue
**			to put the aliases in.
**
**	Returns:
**		none
**
**	Side Effects:
**		Aliases found are expanded.
**
**	Notes:
**		If NoAlias (the "-n" flag) is set, no aliasing is
**			done.
**
**	Deficiencies:
**		It should complain about names that are aliased to
**			nothing.
*/


#ifdef DBM
typedef struct
{
	char	*dptr;
	int	dsize;
} DATUM;
extern DATUM fetch();
#endif DBM

alias(a, sendq)
	register ADDRESS *a;
	ADDRESS **sendq;
{
	register char *p;
	extern char *aliaslookup();

# ifdef DEBUG
	if (tTd(27, 1))
		printf("alias(%s)\n", a->q_paddr);
# endif

	/* don't realias already aliased names */
	if (bitset(QDONTSEND, a->q_flags))
		return;

	CurEnv->e_to = a->q_paddr;

	/*
	**  Look up this name
	*/

	if (NoAlias)
		p = NULL;
	else
		p = aliaslookup(a->q_user);
	if (p == NULL)
		return;

	/*
	**  Match on Alias.
	**	Deliver to the target list.
	*/

# ifdef DEBUG
	if (tTd(27, 1))
		printf("%s (%s, %s) aliased to %s\n",
		    a->q_paddr, a->q_host, a->q_user, p);
# endif
	message(Arpa_Info, "aliased to %s", p);
	AliasLevel++;
	sendtolist(p, a, sendq);
	AliasLevel--;
}
/*
**  ALIASLOOKUP -- look up a name in the alias file.
**
**	Parameters:
**		name -- the name to look up.
**
**	Returns:
**		the value of name.
**		NULL if unknown.
**
**	Side Effects:
**		none.
**
**	Warnings:
**		The return value will be trashed across calls.
*/

char * aliaslookup_local();
char * aliaslookup_yp();
char * aliaslookup_bind();
char * (*aliaslookups []) ()={
		aliaslookup_local,
		aliaslookup_yp,
		aliaslookup_bind
};


/*
 * generic alias service routines
 */

char *
aliaslookup (name)
	register char *name;
{
	register char *p=NULL;
	register i;
	struct svcinfo *svcinfo;

	if ((svcinfo = getsvc()) != NULL)
		for (i=0; (svc_lastlookup = svcinfo->svcpath[SVC_ALIASES][i]) != SVC_LAST; i++)
			if (p = ((*(aliaslookups [svcinfo->svcpath[SVC_ALIASES][i]])) (name) ))
				break;
	return (p);
}

/*
 * specific alias service routines
 */

char *
aliaslookup_local(name)
	char *name;
{
# ifdef DBM
	DATUM rhs, lhs;

#ifdef DEBUG
	printf("aliaslookup_local(%s)\n", name);
#endif DEBUG
	/*
	 * Create a key for fetch
	 */
	lhs.dptr = name;
	lhs.dsize = strlen(name) + 1;
	rhs = fetch(lhs);

	if (rhs.dptr == NULL)
		return(NULL);
	return (rhs.dptr);
# else DBM
	register STAB *s;

#ifdef DEBUG
	printf("aliaslookup_local(%s)\n", name);
#endif DEBUG
	s = stab(name, ST_ALIAS, ST_FIND);

	if (s == NULL)
		return(NULL);
	return (s->s_alias);
# endif DBM
}

char *
aliaslookup_bind(name)
	char *name;
{
	char **pp;
	
#ifdef DEBUG
	printf("aliaslookup_bind(%s)\n", name);
#endif DEBUG
	setent_bind(0);
	pp = hes_resolve(name, "aliases");
	endent_bind();
	if (pp == NULL)
		return(NULL);
	return(*pp);
}

char *
aliaslookup_yp(name)
	char *name;
{
# ifdef DBM
	DATUM rhs;
	int err = 0;

	if (!YPdomain)
		return(NULL);

# ifdef DEBUG
	printf("aliaslookup_yp(%s)\n", name);

	/* Note: The only time you can see the following message
	 *	 is via a  "telnet host 25"   command   AND  the
	 *	 DEBUG code has been compiled in.
	 *	 mail -v user  would show on terminal IF we wanted
	 *	 to put in a  "message(Arpa_Info...)"  statement..
	 */
	if (tTd(27, 1))
		printf("cking YP mail.aliases map for  %s\n",name);
# endif DEBUG
	err = yp_match(YPdomain,"mail.aliases",name,strlen(name),&rhs.dptr,&rhs.dsize);
	if (err == YPERR_KEY) {
		err = yp_match(YPdomain,"mail.aliases",name,strlen(name) + 1 ,&rhs.dptr,&rhs.dsize);
		if (err) {
			/* Assume end of alias chain.
			 */
			return(NULL);
		}
	}
# ifdef DEBUG
	if (tTd(27, 1))
		printf("YP map aliases %s to %s\n",name,rhs.dptr);
# endif DEBUG
	/* The end of an alias from YP comes back with a
	 * newline. This disrupts the syslog entries and
	 * the qfAAnnnnnn entries for recipients. Therefore,
	 * squash them off.
	 */
	if (rhs.dptr[rhs.dsize] == '\n')
		rhs.dptr[rhs.dsize--] = NULL;	
	/*
	 * rhs.dptr will be null if the object is not found
	 * in the YP map. Therefore, no need to ck "err".
	 */
	return (rhs.dptr);

# else DBM
	register STAB *s;

	if (!YPdomain)
		return(NULL);
	else {
		err = yp_match(YPdomain,"mail.aliases",name,strlen(name),&s->s_alias,&size);
		if (err == YPERR_KEY) {
			err = yp_match(YPdomain,"mail.aliases",name,strlen(name) + 1 ,&s->s_alias,&size);
			if (err) {
				/* Assume end of alias chain.
				 */
				return(NULL);
			}
		}
	}
	return (s->s_alias);
# endif DBM
}

/*
**  INITALIASES -- initialize for aliasing
**
**	Very different depending on whether we are running DBM or not.
**
**	Parameters:
**		aliasfile -- location of aliases.
**		init -- if set and if DBM, initialize the DBM files.
**
**	Returns:
**		none.
**
**	Side Effects:
**		initializes aliases:
**		if DBM:  opens the database.
**		if ~DBM: reads the aliases into the symbol table.
*/

# define DBMMODE	0666

initaliases(aliasfile, init)
	char *aliasfile;
	bool init;
{
#ifdef DBM
	int atcnt;
	time_t modtime;
	bool automatic = FALSE;
	char buf[MAXNAME];
#endif DBM
	struct stat stb;
	static bool initialized = FALSE;

	if (initialized)
		return;
	initialized = TRUE;

	if (aliasfile == NULL || stat(aliasfile, &stb) < 0)
	{
		if (aliasfile != NULL && init)
			syserr("Cannot open %s", aliasfile);
		NoAlias = TRUE;
		errno = 0;
		return;
	}

# ifdef DBM
	/*
	**  Check to see that the alias file is complete.
	**	If not, we will assume that someone died, and it is up
	**	to us to rebuild it.
	*/

	if (!init)
		dbminit(aliasfile);
	atcnt = SafeAlias * 2;
	if (atcnt > 0)
	{
		while (!init && atcnt-- >= 0 && aliaslookup("@") == NULL)
		{
			/*
			**  Reinitialize alias file in case the new
			**  one is mv'ed in instead of cp'ed in.
			**
			**	Only works with new DBM -- old one will
			**	just consume file descriptors forever.
			**	If you have a dbmclose() it can be
			**	added before the sleep(30).
			*/

			sleep(30);
# ifdef NDBM
			dbminit(aliasfile);
# endif NDBM
		}
	}
	else
		atcnt = 1;

	/*
	**  See if the DBM version of the file is out of date with
	**  the text version.  If so, go into 'init' mode automatically.
	**	This only happens if our effective userid owns the DBM
	**	version or if the mode of the database is 666 -- this
	**	is an attempt to avoid protection problems.  Note the
	**	unpalatable hack to see if the stat succeeded.
	*/