udb.c

早期freebsd实现

/*
 * Copyright (c) 1983 Eric P. Allman
 * Copyright (c) 1988, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "sendmail.h"

#ifndef lint
#ifdef USERDB
static char sccsid [] = "@(#)udb.c	8.8 (Berkeley) 4/14/94 (with USERDB)";
#else
static char sccsid [] = "@(#)udb.c	8.8 (Berkeley) 4/14/94 (without USERDB)";
#endif
#endif

#ifdef USERDB

#include <errno.h>
#include <netdb.h>
#include <db.h>

#ifdef HESIOD
#include <hesiod.h>
#endif /* HESIOD */

/*
**  UDB.C -- interface between sendmail and Berkeley User Data Base.
**
**	This depends on the 4.4BSD db package.
*/


struct udbent
{
	char	*udb_spec;		/* string version of spec */
	int	udb_type;		/* type of entry */
	char	*udb_default;		/* default host for outgoing mail */
	union
	{
		/* type UE_REMOTE -- do remote call for lookup */
		struct
		{
			struct sockaddr_in _udb_addr;	/* address */
			int		_udb_timeout;	/* timeout */
		} udb_remote;
#define udb_addr	udb_u.udb_remote._udb_addr
#define udb_timeout	udb_u.udb_remote._udb_timeout

		/* type UE_FORWARD -- forward message to remote */
		struct
		{
			char	*_udb_fwdhost;	/* name of forward host */
		} udb_forward;
#define udb_fwdhost	udb_u.udb_forward._udb_fwdhost

		/* type UE_FETCH -- lookup in local database */
		struct
		{
			char	*_udb_dbname;	/* pathname of database */
			DB	*_udb_dbp;	/* open database ptr */
		} udb_lookup;
#define udb_dbname	udb_u.udb_lookup._udb_dbname
#define udb_dbp		udb_u.udb_lookup._udb_dbp
	} udb_u;
};

#define UDB_EOLIST	0	/* end of list */
#define UDB_SKIP	1	/* skip this entry */
#define UDB_REMOTE	2	/* look up in remote database */
#define UDB_DBFETCH	3	/* look up in local database */
#define UDB_FORWARD	4	/* forward to remote host */
#define UDB_HESIOD	5	/* look up via hesiod */

#define MAXUDBENT	10	/* maximum number of UDB entries */


struct option
{
	char	*name;
	char	*val;
};
/*
**  UDBEXPAND -- look up user in database and expand
**
**	Parameters:
**		a -- address to expand.
**		sendq -- pointer to head of sendq to put the expansions in.
**
**	Returns:
**		EX_TEMPFAIL -- if something "odd" happened -- probably due
**			to accessing a file on an NFS server that is down.
**		EX_OK -- otherwise.
**
**	Side Effects:
**		Modifies sendq.
*/

int	UdbPort = 1616;
int	UdbTimeout = 10;

struct udbent	UdbEnts[MAXUDBENT + 1];
int		UdbSock = -1;
bool		UdbInitialized = FALSE;

int
udbexpand(a, sendq, e)
	register ADDRESS *a;
	ADDRESS **sendq;
	register ENVELOPE *e;
{
	int i;
	register char *p;
	DBT key;
	DBT info;
	bool breakout;
	register struct udbent *up;
	int keylen;
	int naddrs;
	char keybuf[MAXKEY];
	char buf[BUFSIZ];

	if (tTd(28, 1))
		printf("udbexpand(%s)\n", a->q_paddr);

	/* make certain we are supposed to send to this address */
	if (bitset(QDONTSEND|QVERIFIED, a->q_flags))
		return EX_OK;
	e->e_to = a->q_paddr;

	/* on first call, locate the database */
	if (!UdbInitialized)
	{
		extern int _udbx_init();

		if (_udbx_init() == EX_TEMPFAIL)
			return EX_TEMPFAIL;
	}

	/* short circuit the process if no chance of a match */
	if (UdbSpec == NULL || UdbSpec[0] == '\0')
		return EX_OK;

	/* short circuit name begins with '\\' since it can't possibly match */
	if (a->q_user[0] == '\\')
		return EX_OK;

	/* if name is too long, assume it won't match */
	if (strlen(a->q_user) > sizeof keybuf - 12)
		return EX_OK;

	/* if name begins with a colon, it indicates our metadata */
	if (a->q_user[0] == ':')
		return EX_OK;

	/* build actual database key */
	(void) strcpy(keybuf, a->q_user);
	(void) strcat(keybuf, ":maildrop");
	keylen = strlen(keybuf);

	breakout = FALSE;
	for (up = UdbEnts; !breakout; up++)
	{
		char *user;

		/*
		**  Select action based on entry type.
		**
		**	On dropping out of this switch, "class" should
		**	explain the type of the data, and "user" should
		**	contain the user information.
		*/

		switch (up->udb_type)
		{
		  case UDB_DBFETCH:
			key.data = keybuf;
			key.size = keylen;
			if (tTd(28, 80))
				printf("udbexpand: trying %s (%d) via db\n",
					keybuf, keylen);
			i = (*up->udb_dbp->seq)(up->udb_dbp, &key, &info, R_CURSOR);
			if (i > 0 || info.size <= 0)
			{
				if (tTd(28, 2))
					printf("udbexpand: no match on %s (%d)\n",
						keybuf, keylen);
				continue;
			}
			if (tTd(28, 80))
				printf("udbexpand: match %.*s: %.*s\n",
					key.size, key.data, info.size, info.data);

			naddrs = 0;
			a->q_flags &= ~QSELFREF;
			while (i == 0 && key.size == keylen &&
					bcmp(key.data, keybuf, keylen) == 0)
			{
				if (bitset(EF_VRFYONLY, e->e_flags))
				{
					a->q_flags |= QVERIFIED;
					e->e_nrcpts++;
					return EX_OK;
				}

				breakout = TRUE;
				if (info.size < sizeof buf)
					user = buf;
				else
					user = xalloc(info.size + 1);
				bcopy(info.data, user, info.size);
				user[info.size] = '\0';

				message("expanded to %s", user);
#ifdef LOG
				if (LogLevel >= 10)
					syslog(LOG_INFO, "%s: expand %s => %s",
						e->e_id, e->e_to, user);
#endif
				AliasLevel++;
				naddrs += sendtolist(user, a, sendq, e);
				AliasLevel--;

				if (user != buf)
					free(user);

				/* get the next record */
				i = (*up->udb_dbp->seq)(up->udb_dbp, &key, &info, R_NEXT);
			}

			/* if nothing ever matched, try next database */
			if (!breakout)
				continue;

			if (naddrs > 0 && !bitset(QSELFREF, a->q_flags))
			{
				if (tTd(28, 5))
				{
					printf("udbexpand: QDONTSEND ");
					printaddr(a, FALSE);
				}
				a->q_flags |= QDONTSEND;
			}
			if (i < 0)
			{
				syserr("udbexpand: db-get %.*s stat %d",
					key.size, key.data, i);
				return EX_TEMPFAIL;
			}

			/*
			**  If this address has a -request address, reflect
			**  it into the envelope.
			*/

			(void) strcpy(keybuf, a->q_user);
			(void) strcat(keybuf, ":mailsender");
			keylen = strlen(keybuf);
			key.data = keybuf;
			key.size = keylen;
			i = (*up->udb_dbp->get)(up->udb_dbp, &key, &info, 0);
			if (i != 0 || info.size <= 0)
				break;
			a->q_owner = xalloc(info.size + 1);
			bcopy(info.data, a->q_owner, info.size);
			a->q_owner[info.size] = '\0';

			/* announce delivery; NORECEIPT bit set later */
			if (e->e_xfp != NULL)
			{
				fprintf(e->e_xfp,
					"Message delivered to mailing list %s\n",
					a->q_paddr);
				e->e_flags |= EF_SENDRECEIPT;
			}
			break;

#ifdef HESIOD
		  case UDB_HESIOD:
			key.data = keybuf;
			key.size = keylen;
			if (tTd(28, 80))
				printf("udbexpand: trying %s (%d) via hesiod\n",
					keybuf, keylen);
			/* look up the key via hesiod */
			i = hes_udb_get(&key, &info);
			if (i > 0 || info.size <= 0)
			{
				if (tTd(28, 2))
				printf("udbexpand: no match on %s (%d)\n",
					keybuf, keylen);
				continue;
			}
			if (tTd(28, 80))
				printf("udbexpand: match %.*s: %.*s\n",
					key.size, key.data, info.size, info.data);
			a->q_flags &= ~QSELFREF;

			if (bitset(EF_VRFYONLY, e->e_flags))
			{
				a->q_flags |= QVERIFIED;
				e->e_nrcpts++;
				free(info.data);
				return EX_OK;
			}

			breakout = TRUE;
			if (info.size < sizeof buf)
				user = buf;
			else
				user = xalloc(info.size + 1);
			bcopy(info.data, user, info.size);
			user[info.size] = '\0';
			free(info.data);

			message("hesioded to %s", user);
#ifdef LOG
			if (LogLevel >= 10)
				syslog(LOG_INFO, "%s: hesiod %s => %s",
					e->e_id, e->e_to, user);
#endif
			AliasLevel++;
			naddrs = sendtolist(user, a, sendq, e);
			AliasLevel--;

			if (user != buf)
				free(user);

			if (naddrs > 0 && !bitset(QSELFREF, a->q_flags))
			{
				if (tTd(28, 5))
				{
					printf("udbexpand: QDONTSEND ");
					printaddr(a, FALSE);
				}
				a->q_flags |= QDONTSEND;
			}
			if (i < 0)
			{
				syserr("udbexpand: hesiod-get %.*s stat %d",
					key.size, key.data, i);
				return EX_TEMPFAIL;
			}

			/*
			**  If this address has a -request address, reflect
			**  it into the envelope.
			*/

			(void) strcpy(keybuf, a->q_user);
			(void) strcat(keybuf, ":mailsender");
			keylen = strlen(keybuf);
			key.data = keybuf;
			key.size = keylen;
			i = hes_udb_get(&key, &info);
			if (i != 0 || info.size <= 0)
				break;
			a->q_owner = xalloc(info.size + 1);
			bcopy(info.data, a->q_owner, info.size);
			a->q_owner[info.size] = '\0';
			free(info.data);
			break;
#endif /* HESIOD */

		  case UDB_REMOTE:
			/* not yet implemented */
			continue;

		  case UDB_FORWARD:
			if (bitset(EF_VRFYONLY, e->e_flags))
				return EX_OK;
			i = strlen(up->udb_fwdhost) + strlen(a->q_user) + 1;
			if (i < sizeof buf)
				user = buf;
			else
				user = xalloc(i + 1);
			(void) sprintf(user, "%s@%s", a->q_user, up->udb_fwdhost);
			message("expanded to %s", user);
			a->q_flags &= ~QSELFREF;
			AliasLevel++;
			naddrs = sendtolist(user, a, sendq, e);
			AliasLevel--;
			if (naddrs > 0 && !bitset(QSELFREF, a->q_flags))
			{
				if (tTd(28, 5))
				{
					printf("udbexpand: QDONTSEND ");
					printaddr(a, FALSE);
				}
				a->q_flags |= QDONTSEND;
			}
			if (user != buf)
				free(user);
			breakout = TRUE;
			break;

		  case UDB_EOLIST:
			breakout = TRUE;
			continue;

		  default:
			/* unknown entry type */
			continue;
		}
	}
	return EX_OK;
}
/*
**  UDBSENDER -- return canonical external name of sender, given local name
**
**	Parameters:
**		sender -- the name of the sender on the local machine.
**
**	Returns:
**		The external name for this sender, if derivable from the
**			database.
**		NULL -- if nothing is changed from the database.
**
**	Side Effects:
**		none.
*/

char *
udbsender(sender)
	char *sender;
{
	extern char *udbmatch();

	return udbmatch(sender, "mailname");
}


char *
udbmatch(user, field)
	char *user;
	char *field;
{
	register char *p;
	register struct udbent *up;
	int i;
	int keylen;
	DBT key, info;
	char keybuf[MAXKEY];

	if (tTd(28, 1))
		printf("udbmatch(%s, %s)\n", user, field);

	if (!UdbInitialized)
	{
		if (_udbx_init() == EX_TEMPFAIL)
			return NULL;
	}

	/* short circuit if no spec */
	if (UdbSpec == NULL || UdbSpec[0] == '\0')
		return NULL;

	/* short circuit name begins with '\\' since it can't possibly match */
	if (user[0] == '\\')
		return NULL;

	/* long names can never match and are a pain to deal with */
	if ((strlen(user) + strlen(field)) > sizeof keybuf - 4)
		return NULL;