/contrib/sendmail/src/map.c

/*
 * Copyright (c) 1998-2008 Sendmail, Inc. and its suppliers.
 *	All rights reserved.
 * Copyright (c) 1992, 1995-1997 Eric P. Allman.  All rights reserved.
 * Copyright (c) 1992, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * By using this file, you agree to the terms and conditions set
 * forth in the LICENSE file which can be found at the top level of
 * the sendmail distribution.
 *
 */

#include <sendmail.h>

SM_RCSID("@(#)$Id: map.c,v 8.706 2010/07/27 03:35:42 ca Exp $")

#if LDAPMAP
# include <sm/ldap.h>
#endif /* LDAPMAP */

#if NDBM
# include <ndbm.h>
# ifdef R_FIRST
  ERROR README:	You are running the Berkeley DB version of ndbm.h.  See
  ERROR README:	the README file about tweaking Berkeley DB so it can
  ERROR README:	coexist with NDBM, or delete -DNDBM from the Makefile
  ERROR README: and use -DNEWDB instead.
# endif /* R_FIRST */
#endif /* NDBM */
#if NEWDB
# include "sm/bdb.h"
#endif /* NEWDB */
#if NIS
  struct dom_binding;	/* forward reference needed on IRIX */
# include <rpcsvc/ypclnt.h>
# if NDBM
#  define NDBM_YP_COMPAT	/* create YP-compatible NDBM files */
# endif /* NDBM */
#endif /* NIS */

#include "map.h"

#if NEWDB
# if DB_VERSION_MAJOR < 2
static bool	db_map_open __P((MAP *, int, char *, DBTYPE, const void *));
# endif /* DB_VERSION_MAJOR < 2 */
# if DB_VERSION_MAJOR == 2
static bool	db_map_open __P((MAP *, int, char *, DBTYPE, DB_INFO *));
# endif /* DB_VERSION_MAJOR == 2 */
# if DB_VERSION_MAJOR > 2
static bool	db_map_open __P((MAP *, int, char *, DBTYPE, void **));
# endif /* DB_VERSION_MAJOR > 2 */
#endif /* NEWDB */
static bool	extract_canonname __P((char *, char *, char *, char[], int));
static void	map_close __P((STAB *, int));
static void	map_init __P((STAB *, int));
#ifdef LDAPMAP
static STAB *	ldapmap_findconn __P((SM_LDAP_STRUCT *));
#endif /* LDAPMAP */
#if NISPLUS
static bool	nisplus_getcanonname __P((char *, int, int *));
#endif /* NISPLUS */
#if NIS
static bool	nis_getcanonname __P((char *, int, int *));
#endif /* NIS */
#if NETINFO
static bool	ni_getcanonname __P((char *, int, int *));
#endif /* NETINFO */
static bool	text_getcanonname __P((char *, int, int *));
#if SOCKETMAP
static STAB	*socket_map_findconn __P((const char*));

/* XXX arbitrary limit for sanity */
# define SOCKETMAP_MAXL 1000000
#endif /* SOCKETMAP */

/* default error message for trying to open a map in write mode */
#ifdef ENOSYS
# define SM_EMAPCANTWRITE	ENOSYS
#else /* ENOSYS */
# ifdef EFTYPE
#  define SM_EMAPCANTWRITE	EFTYPE
# else /* EFTYPE */
#  define SM_EMAPCANTWRITE	ENXIO
# endif /* EFTYPE */
#endif /* ENOSYS */

/*
**  MAP.C -- implementations for various map classes.
**
**	Each map class implements a series of functions:
**
**	bool map_parse(MAP *map, char *args)
**		Parse the arguments from the config file.  Return true
**		if they were ok, false otherwise.  Fill in map with the
**		values.
**
**	char *map_lookup(MAP *map, char *key, char **args, int *pstat)
**		Look up the key in the given map.  If found, do any
**		rewriting the map wants (including "args" if desired)
**		and return the value.  Set *pstat to the appropriate status
**		on error and return NULL.  Args will be NULL if called
**		from the alias routines, although this should probably
**		not be relied upon.  It is suggested you call map_rewrite
**		to return the results -- it takes care of null termination
**		and uses a dynamically expanded buffer as needed.
**
**	void map_store(MAP *map, char *key, char *value)
**		Store the key:value pair in the map.
**
**	bool map_open(MAP *map, int mode)
**		Open the map for the indicated mode.  Mode should
**		be either O_RDONLY or O_RDWR.  Return true if it
**		was opened successfully, false otherwise.  If the open
**		failed and the MF_OPTIONAL flag is not set, it should
**		also print an error.  If the MF_ALIAS bit is set
**		and this map class understands the @:@ convention, it
**		should call aliaswait() before returning.
**
**	void map_close(MAP *map)
**		Close the map.
**
**	This file also includes the implementation for getcanonname.
**	It is currently implemented in a pretty ad-hoc manner; it ought
**	to be more properly integrated into the map structure.
*/

#if O_EXLOCK && HASFLOCK && !BOGUS_O_EXCL
# define LOCK_ON_OPEN	1	/* we can open/create a locked file */
#else /* O_EXLOCK && HASFLOCK && !BOGUS_O_EXCL */
# define LOCK_ON_OPEN	0	/* no such luck -- bend over backwards */
#endif /* O_EXLOCK && HASFLOCK && !BOGUS_O_EXCL */

/*
**  MAP_PARSEARGS -- parse config line arguments for database lookup
**
**	This is a generic version of the map_parse method.
**
**	Parameters:
**		map -- the map being initialized.
**		ap -- a pointer to the args on the config line.
**
**	Returns:
**		true -- if everything parsed OK.
**		false -- otherwise.
**
**	Side Effects:
**		null terminates the filename; stores it in map
*/

bool
map_parseargs(map, ap)
	MAP *map;
	char *ap;
{
	register char *p = ap;

	/*
	**  There is no check whether there is really an argument,
	**  but that's not important enough to warrant extra code.
	*/

	map->map_mflags |= MF_TRY0NULL|MF_TRY1NULL;
	map->map_spacesub = SpaceSub;	/* default value */
	for (;;)
	{
		while (isascii(*p) && isspace(*p))
			p++;
		if (*p != '-')
			break;
		switch (*++p)
		{
		  case 'N':
			map->map_mflags |= MF_INCLNULL;
			map->map_mflags &= ~MF_TRY0NULL;
			break;

		  case 'O':
			map->map_mflags &= ~MF_TRY1NULL;
			break;

		  case 'o':
			map->map_mflags |= MF_OPTIONAL;
			break;

		  case 'f':
			map->map_mflags |= MF_NOFOLDCASE;
			break;

		  case 'm':
			map->map_mflags |= MF_MATCHONLY;
			break;

		  case 'A':
			map->map_mflags |= MF_APPEND;
			break;

		  case 'q':
			map->map_mflags |= MF_KEEPQUOTES;
			break;

		  case 'a':
			map->map_app = ++p;
			break;

		  case 'T':
			map->map_tapp = ++p;
			break;

		  case 'k':
			while (isascii(*++p) && isspace(*p))
				continue;
			map->map_keycolnm = p;
			break;

		  case 'v':
			while (isascii(*++p) && isspace(*p))
				continue;
			map->map_valcolnm = p;
			break;

		  case 'z':
			if (*++p != '\\')
				map->map_coldelim = *p;
			else
			{
				switch (*++p)
				{
				  case 'n':
					map->map_coldelim = '\n';
					break;

				  case 't':
					map->map_coldelim = '\t';
					break;

				  default:
					map->map_coldelim = '\\';
				}
			}
			break;

		  case 't':
			map->map_mflags |= MF_NODEFER;
			break;


		  case 'S':
			map->map_spacesub = *++p;
			break;

		  case 'D':
			map->map_mflags |= MF_DEFER;
			break;

		  default:
			syserr("Illegal option %c map %s", *p, map->map_mname);
			break;
		}
		while (*p != '\0' && !(isascii(*p) && isspace(*p)))
			p++;
		if (*p != '\0')
			*p++ = '\0';
	}
	if (map->map_app != NULL)
		map->map_app = newstr(map->map_app);
	if (map->map_tapp != NULL)
		map->map_tapp = newstr(map->map_tapp);
	if (map->map_keycolnm != NULL)
		map->map_keycolnm = newstr(map->map_keycolnm);
	if (map->map_valcolnm != NULL)
		map->map_valcolnm = newstr(map->map_valcolnm);

	if (*p != '\0')
	{
		map->map_file = p;
		while (*p != '\0' && !(isascii(*p) && isspace(*p)))
			p++;
		if (*p != '\0')
			*p++ = '\0';
		map->map_file = newstr(map->map_file);
	}

	while (*p != '\0' && isascii(*p) && isspace(*p))
		p++;
	if (*p != '\0')
		map->map_rebuild = newstr(p);

	if (map->map_file == NULL &&
	    !bitset(MCF_OPTFILE, map->map_class->map_cflags))
	{
		syserr("No file name for %s map %s",
			map->map_class->map_cname, map->map_mname);
		return false;
	}
	return true;
}
/*
**  MAP_REWRITE -- rewrite a database key, interpolating %n indications.
**
**	It also adds the map_app string.  It can be used as a utility
**	in the map_lookup method.
**
**	Parameters:
**		map -- the map that causes this.
**		s -- the string to rewrite, NOT necessarily null terminated.
**		slen -- the length of s.
**		av -- arguments to interpolate into buf.
**
**	Returns:
**		Pointer to rewritten result.  This is static data that
**		should be copied if it is to be saved!
*/

char *
map_rewrite(map, s, slen, av)
	register MAP *map;
	register const char *s;
	size_t slen;
	char **av;
{
	register char *bp;
	register char c;
	char **avp;
	register char *ap;
	size_t l;
	size_t len;
	static size_t buflen = 0;
	static char *buf = NULL;

	if (tTd(39, 1))
	{
		sm_dprintf("map_rewrite(%.*s), av =", (int) slen, s);
		if (av == NULL)
			sm_dprintf(" (nullv)");
		else
		{
			for (avp = av; *avp != NULL; avp++)
				sm_dprintf("\n\t%s", *avp);
		}
		sm_dprintf("\n");
	}

	/* count expected size of output (can safely overestimate) */
	l = len = slen;
	if (av != NULL)
	{
		const char *sp = s;

		while (l-- > 0 && (c = *sp++) != '\0')
		{
			if (c != '%')
				continue;
			if (l-- <= 0)
				break;
			c = *sp++;
			if (!(isascii(c) && isdigit(c)))
				continue;
			for (avp = av; --c >= '0' && *avp != NULL; avp++)
				continue;
			if (*avp == NULL)
				continue;
			len += strlen(*avp);
		}
	}
	if (map->map_app != NULL)
		len += strlen(map->map_app);
	if (buflen < ++len)
	{
		/* need to malloc additional space */
		buflen = len;
		if (buf != NULL)
			sm_free(buf);
		buf = sm_pmalloc_x(buflen);
	}

	bp = buf;
	if (av == NULL)
	{
		memmove(bp, s, slen);
		bp += slen;

		/* assert(len > slen); */
		len -= slen;
	}
	else
	{
		while (slen-- > 0 && (c = *s++) != '\0')
		{
			if (c != '%')
			{
  pushc:
				if (len-- <= 1)
				     break;
				*bp++ = c;
				continue;
			}
			if (slen-- <= 0 || (c = *s++) == '\0')
				c = '%';
			if (c == '%')
				goto pushc;
			if (!(isascii(c) && isdigit(c)))
			{
				if (len-- <= 1)
				     break;
				*bp++ = '%';
				goto pushc;
			}
			for (avp = av; --c >= '0' && *avp != NULL; avp++)
				continue;
			if (*avp == NULL)
				continue;

			/* transliterate argument into output string */
			for (ap = *avp; (c = *ap++) != '\0' && len > 0; --len)
				*bp++ = c;
		}
	}
	if (map->map_app != NULL && len > 0)
		(void) sm_strlcpy(bp, map->map_app, len);
	else
		*bp = '\0';
	if (tTd(39, 1))
		sm_dprintf("map_rewrite => %s\n", buf);
	return buf;
}
/*
**  INITMAPS -- rebuild alias maps
**
**	Parameters:
**		none.
**
**	Returns:
**		none.
*/

void
initmaps()
{
#if XDEBUG
	checkfd012("entering initmaps");
#endif /* XDEBUG */
	stabapply(map_init, 0);
#if XDEBUG
	checkfd012("exiting initmaps");
#endif /* XDEBUG */
}
/*
**  MAP_INIT -- rebuild a map
**
**	Parameters:
**		s -- STAB entry: if map: try to rebuild
**		unused -- unused variable
**
**	Returns:
**		none.
**
**	Side Effects:
**		will close already open rebuildable map.
*/

/* ARGSUSED1 */
static void
map_init(s, unused)
	register STAB *s;
	int unused;
{
	register MAP *map;

	/* has to be a map */
	if (s->s_symtype != ST_MAP)
		return;

	map = &s->s_map;
	if (!bitset(MF_VALID, map->map_mflags))
		return;

	if (tTd(38, 2))
		sm_dprintf("map_init(%s:%s, %s)\n",
			map->map_class->map_cname == NULL ? "NULL" :
				map->map_class->map_cname,
			map->map_mname == NULL ? "NULL" : map->map_mname,
			map->map_file == NULL ? "NULL" : map->map_file);

	if (!bitset(MF_ALIAS, map->map_mflags) ||
	    !bitset(MCF_REBUILDABLE, map->map_class->map_cflags))
	{
		if (tTd(38, 3))
			sm_dprintf("\tnot rebuildable\n");
		return;
	}

	/* if already open, close it (for nested open) */
	if (bitset(MF_OPEN, map->map_mflags))
	{
		map->map_mflags |= MF_CLOSING;
		map->map_class->map_close(map);
		map->map_mflags &= ~(MF_OPEN|MF_WRITABLE|MF_CLOSING);
	}

	(void) rebuildaliases(map, false);
	return;
}
/*
**  OPENMAP -- open a map
**
**	Parameters:
**		map -- map to open (it must not be open).
**
**	Returns:
**		whether open succeeded.
*/

bool
openmap(map)
	MAP *map;
{
	bool restore = false;
	bool savehold = HoldErrs;
	bool savequick = QuickAbort;
	int saveerrors = Errors;

	if (!bitset(MF_VALID, map->map_mflags))
		return false;

	/* better safe than sorry... */
	if (bitset(MF_OPEN, map->map_mflags))
		return true;

	/* Don't send a map open error out via SMTP */
	if ((OnlyOneError || QuickAbort) &&
	    (OpMode == MD_SMTP || OpMode == MD_DAEMON))
	{
		restore = true;
		HoldErrs = true;
		QuickAbort = false;
	}

	errno = 0;
	if (map->map_class->map_open(map, O_RDONLY))
	{
		if (tTd(38, 4))
			sm_dprintf("openmap()\t%s:%s %s: valid\n",
				map->map_class->map_cname == NULL ? "NULL" :
					map->map_class->map_cname,
				map->map_mname == NULL ? "NULL" :
					map->map_mname,
				map->map_file == NULL ? "NULL" :
					map->map_file);
		map->map_mflags |= MF_OPEN;
		map->map_pid = CurrentPid;
	}
	else
	{
		if (tTd(38, 4))
			sm_dprintf("openmap()\t%s:%s %s: invalid%s%s\n",
				map->map_class->map_cname == NULL ? "NULL" :
					map->map_class->map_cname,
				map->map_mname == NULL ? "NULL" :
					map->map_mname,
				map->map_file == NULL ? "NULL" :
					map->map_file,
				errno == 0 ? "" : ": ",
				errno == 0 ? "" : sm_errstring(errno));
		if (!bitset(MF_OPTIONAL, map->map_mflags))
		{
			extern MAPCLASS BogusMapClass;

			map->map_orgclass = map->map_class;
			map->map_class = &BogusMapClass;
			map->map_mflags |= MF_OPEN|MF_OPENBOGUS;
			map->map_pid = CurrentPid;
		}
		else
		{
			/* don't try again */
			map->map_mflags &= ~MF_VALID;
		}
	}

	if (restore)
	{
		Errors = saveerrors;
		HoldErrs = savehold;
		QuickAbort = savequick;
	}

	return bitset(MF_OPEN, map->map_mflags);
}
/*
**  CLOSEMAPS -- close all open maps opened by the current pid.
**
**	Parameters:
**		bogus -- only close bogus maps.
**
**	Returns:
**		none.
*/

void
closemaps(bogus)
	bool bogus;
{
	stabapply(map_close, bogus);
}
/*
**  MAP_CLOSE -- close a map opened by the current pid.
**
**	Parameters:
**		s -- STAB entry: if map: try to close
**		bogus -- only close bogus maps or MCF_NOTPERSIST maps.
**
**	Returns:
**		none.
*/

/* ARGSUSED1 */
static void
map_close(s, bogus)
	register STAB *s;
	int bogus;	/* int because of stabapply(), used as bool */
{
	MAP *map;
	extern MAPCLASS BogusMapClass;

	if (s->s_symtype != ST_MAP)
		return;

	map = &s->s_map;

	/*
	**  close the map iff:
	**  it is valid and open and opened by this process
	**  and (!bogus or it's a bogus map or it is not persistent)
	**  negate this: return iff
	**  it is not valid or it is not open or not opened by this process
	**  or (bogus and it's not a bogus map and it's not not-persistent)
	*/

	if (!bitset(MF_VALID, map->map_mflags) ||
	    !bitset(MF_OPEN, map->map_mflags) ||
	    bitset(MF_CLOSING, map->map_mflags) ||
	    map->map_pid != CurrentPid ||
	    (bogus && map->map_class != &BogusMapClass &&
	     !bitset(MCF_NOTPERSIST, map->map_class->map_cflags)))
		return;

	if (map->map_class == &BogusMapClass && map->map_orgclass != NULL &&
	    map->map_orgclass != &BogusMapClass)
		map->map_class = map->map_orgclass;
	if (tTd(38, 5))
		sm_dprintf("closemaps: closing %s (%s)\n",
			map->map_mname == NULL ? "NULL" : map->map_mname,
			map->map_file == NULL ? "NULL" : map->map_file);

	if (!bitset(MF_OPENBOGUS, map->map_mflags))
	{
		map->map_mflags |= MF_CLOSING;
		map->map_class->map_close(map);
	}
	map->map_mflags &= ~(MF_OPEN|MF_WRITABLE|MF_OPENBOGUS|MF_CLOSING);
}

#if defined(SUN_EXTENSIONS) && defined(SUN_INIT_DOMAIN)
extern int getdomainname();

/* this is mainly for backward compatibility in Sun environment */
static char *
sun_init_domain()
{
	/*
	**  Get the domain name from the kernel.
	**  If it does not start with a leading dot, then remove
	**  the first component.  Since leading dots are funny Unix
	**  files, we treat a leading "+" the same as a leading dot.
	**  Finally, force there to be at least one dot in the domain name
	**  (i.e. top-level domains are not allowed, like "com", must be
	**  something like "sun.com").
	*/

	char buf[MAXNAME];
	char *period, *autodomain;

	if (getdomainname(buf, sizeof buf) < 0)
		return NULL;

	if (buf[0] == '\0')
		return NULL;

	if (tTd(0, 20))
		printf("domainname = %s\n", buf);

	if (buf[0] == '+')
		buf[0] = '.';
	period = strchr(buf, '.');
	if (period == NULL)
		autodomain = buf;
	else
		autodomain = period + 1;
	if (strchr(autodomain, '.') == NULL)
		return newstr(buf);
	else
		return newstr(autodomain);
}
#endif /* SUN_EXTENSIONS && SUN_INIT_DOMAIN */

/*
**  GETCANONNAME -- look up name using service switch
**
**	Parameters:
**		host -- the host name to look up.
**		hbsize -- the size of the host buffer.
**		trymx -- if set, try MX records.
**		pttl -- pointer to return TTL (can be NULL).
**
**	Returns:
**		true -- if the host was found.
**		false -- otherwise.
*/

bool
getcanonname(host, hbsize, trymx, pttl)
	char *host;
	int hbsize;
	bool trymx;
	int *pttl;
{
	int nmaps;
	int mapno;
	bool found = false;
	bool got_tempfail = false;
	auto int status = EX_UNAVAILABLE;
	char *maptype[MAXMAPSTACK];
	short mapreturn[MAXMAPACTIONS];
#if defined(SUN_EXTENSIONS) && defined(SUN_INIT_DOMAIN)
	bool should_try_nis_domain = false;
	static char *nis_domain = NULL;
#endif

	nmaps = switch_map_find("hosts", maptype, mapreturn);
	if (pttl != 0)
		*pttl = SM_DEFAULT_TTL;
	for (mapno = 0; mapno < nmaps; mapno++)
	{
		int i;

		if (tTd(38, 20))
			sm_dprintf("getcanonname(%s), trying %s\n",
				host, maptype[mapno]);
		if (strcmp("files", maptype[mapno]) == 0)
		{
			found = text_getcanonname(host, hbsize, &status);
		}
#if NIS
		else if (strcmp("nis", maptype[mapno]) == 0)
		{
			found = nis_getcanonname(host, hbsize, &status);
# if defined(SUN_EXTENSIONS) && defined(SUN_INIT_DOMAIN)
			if (nis_domain == NULL)
				nis_domain = sun_init_domain();
# endif /* defined(SUN_EXTENSIONS) && defined(SUN_INIT_DOMAIN) */
		}
#endif /* NIS */
#if NISPLUS
		else if (strcmp("nisplus", maptype[mapno]) == 0)
		{
			found = nisplus_getcanonname(host, hbsize, &status);
# if defined(SUN_EXTENSIONS) && defined(SUN_INIT_DOMAIN)
			if (nis_domain == NULL)
				nis_domain = sun_init_domain();
# endif /* defined(SUN_EXTENSIONS) && defined(SUN_INIT_DOMAIN) */
		}
#endif /* NISPLUS */
#if NAMED_BIND
		else if (strcmp("dns", maptype[mapno]) == 0)
		{
			found = dns_getcanonname(host, hbsize, trymx, &status,							 pttl);
		}
#endif /* NAMED_BIND */
#if NETINFO
		else if (strcmp("netinfo", maptype[mapno]) == 0)
		{
			found = ni_getcanonname(host, hbsize, &status);
		}
#endif /* NETINFO */
		else
		{
			found = false;
			status = EX_UNAVAILABLE;
		}

		/*
		**  Heuristic: if $m is not set, we are running during system
		**  startup.  In this case, when a name is apparently found
		**  but has no dot, treat is as not found.  This avoids
		**  problems if /etc/hosts has no FQDN but is listed first
		**  in the service switch.
		*/

		if (found &&
		    (macvalue('m', CurEnv) != NULL || strchr(host, '.') != NULL))
			break;

#if defined(SUN_EXTENSIONS) && defined(SUN_INIT_DOMAIN)
		if (found)
			should_try_nis_domain = true;
		/* but don't break, as we need to try all methods first */
#endif /* defined(SUN_EXTENSIONS) && defined(SUN_INIT_DOMAIN) */

		/* see if we should continue */
		if (status == EX_TEMPFAIL)
		{
			i = MA_TRYAGAIN;
			got_tempfail = true;
		}
		else if (status == EX_NOTFOUND)
			i = MA_NOTFOUND;
		else
			i = MA_UNAVAIL;
		if (bitset(1 << mapno, mapreturn[i]))
			break;
	}

	if (found)
	{
		char *d;

		if (tTd(38, 20))
			sm_dprintf("getcanonname(%s), found\n", host);

		/*
		**  If returned name is still single token, compensate
		**  by tagging on $m.  This is because some sites set
		**  up their DNS or NIS databases wrong.
		*/

		if ((d = strchr(host, '.')) == NULL || d[1] == '\0')
		{
			d = macvalue('m', CurEnv);
			if (d != NULL &&
			    hbsize > (int) (strlen(host) + strlen(d) + 1))
			{
				if (host[strlen(host) - 1] != '.')
					(void) sm_strlcat2(host, ".", d,
							   hbsize);
				else
					(void) sm_strlcat(host, d, hbsize);
			}
			else
			{
#if defined(SUN_EXTENSIONS) && defined(SUN_INIT_DOMAIN)
				if (VendorCode == VENDOR_SUN &&
				    should_try_nis_domain)
				{
					goto try_nis_domain;
				}
#endif /* defined(SUN_EXTENSIONS) && defined(SUN_INIT_DOMAIN) */
				return false;
			}
		}
		return true;
	}

#if defined(SUN_EXTENSIONS) && defined(SUN_INIT_DOMAIN)
	if (VendorCode == VENDOR_SUN && should_try_nis_domain)
	{
  try_nis_domain:
		if (nis_domain != NULL &&
		    strlen(nis_domain) + strlen(host) + 1 < hbsize)
		{
			(void) sm_strlcat2(host, ".", nis_domain, hbsize);
			return true;
		}
	}
#endif /* defined(SUN_EXTENSIONS) && defined(SUN_INIT_DOMAIN) */

	if (tTd(38, 20))
		sm_dprintf("getcanonname(%s), failed, status=%d\n", host,
			status);

	if (got_tempfail)
		SM_SET_H_ERRNO(TRY_AGAIN);
	else
		SM_SET_H_ERRNO(HOST_NOT_FOUND);

	return false;
}
/*
**  EXTRACT_CANONNAME -- extract canonical name from /etc/hosts entry
**
**	Parameters:
**		name -- the name against which to match.
**		dot -- where to reinsert '.' to get FQDN
**		line -- the /etc/hosts line.
**		cbuf -- the location to store the result.
**		cbuflen -- the size of cbuf.
**
**	Returns:
**		true -- if the line matched the desired name.
**		false -- otherwise.
*/

static bool
extract_canonname(name, dot, line, cbuf, cbuflen)
	char *name;
	char *dot;
	char *line;
	char cbuf[];
	int cbuflen;
{
	int i;
	char *p;
	bool found = false;

	cbuf[0] = '\0';
	if (line[0] == '#')
		return false;

	for (i = 1; ; i++)
	{
		char nbuf[MAXNAME + 1];

		p = get_column(line, i, '\0', nbuf, sizeof(nbuf));
		if (p == NULL)
			break;
		if (*p == '\0')
			continue;
		if (cbuf[0] == '\0' ||
		    (strchr(cbuf, '.') == NULL && strchr(p, '.') != NULL))
		{
			(void) sm_strlcpy(cbuf, p, cbuflen);
		}
		if (sm_strcasecmp(name, p) == 0)
			found = true;
		else if (dot != NULL)
		{
			/* try looking for the FQDN as well */
			*dot = '.';
			if (sm_strcasecmp(name, p) == 0)
				found = true;
			*dot = '\0';
		}
	}
	if (found && strchr(cbuf, '.') == NULL)
	{
		/* try to add a domain on the end of the name */
		char *domain = macvalue('m', CurEnv);

		if (domain != NULL &&
		    strlen(domain) + (i = strlen(cbuf)) + 1 < (size_t) cbuflen)
		{
			p = &cbuf[i];
			*p++ = '.';
			(void) sm_strlcpy(p, domain, cbuflen - i - 1);
		}
	}
	return found;
}

/*
**  DNS modules
*/

#if NAMED_BIND
# if DNSMAP

#  include "sm_resolve.h"
#  if NETINET || NETINET6
#   include <arpa/inet.h>
#  endif /* NETINET || NETINET6 */

/*
**  DNS_MAP_OPEN -- stub to check proper value for dns map type
*/

bool
dns_map_open(map, mode)
	MAP *map;
	int mode;
{
	if (tTd(38,2))
		sm_dprintf("dns_map_open(%s, %d)\n", map->map_mname, mode);

	mode &= O_ACCMODE;
	if (mode != O_RDONLY)
	{
		/* issue a pseudo-error message */
		errno = SM_EMAPCANTWRITE;
		return false;
	}
	return true;
}

/*
**  DNS_MAP_PARSEARGS -- parse dns map definition args.
**
**	Parameters:
**		map -- pointer to MAP
**		args -- pointer to the args on the config line.
**
**	Returns:
**		true -- if everything parsed OK.
**		false -- otherwise.
*/

#define map_sizelimit	map_lockfd	/* overload field */

struct dns_map
{
	int dns_m_type;
};

bool
dns_map_parseargs(map,args)
	MAP *map;
	char *args;
{
	register char *p = args;
	struct dns_map *map_p;

	map_p = (struct dns_map *) xalloc(sizeof(*map_p));
	map_p->dns_m_type = -1;
	map->map_mflags |= MF_TRY0NULL|MF_TRY1NULL;

	for (;;)
	{
		while (isascii(*p) && isspace(*p))
			p++;
		if (*p != '-')
			break;
		switch (*++p)
		{
		  case 'N':
			map->map_mflags |= MF_INCLNULL;
			map->map_mflags &= ~MF_TRY0NULL;
			break;

		  case 'O':
			map->map_mflags &= ~MF_TRY1NULL;
			break;

		  case 'o':
			map->map_mflags |= MF_OPTIONAL;
			break;

		  case 'f':
			map->map_mflags |= MF_NOFOLDCASE;
			break;

		  case 'm':
			map->map_mflags |= MF_MATCHONLY;
			break;

		  case 'A':
			map->map_mflags |= MF_APPEND;
			break;

		  case 'q':
			map->map_mflags |= MF_KEEPQUOTES;
			break;

		  case 't':
			map->map_mflags |= MF_NODEFER;
			break;

		  case 'a':
			map->map_app = ++p;
			break;

		  case 'T':
			map->map_tapp = ++p;
			break;

		  case 'd':
			{
				char *h;

				++p;
				h = strchr(p, ' ');
				if (h != NULL)
					*h = '\0';
				map->map_timeout = convtime(p, 's');
				if (h != NULL)
					*h = ' ';
			}
			break;

		  case 'r':
			while (isascii(*++p) && isspace(*p))
				continue;
			map->map_retry = atoi(p);
			break;

		  case 'z':
			if (*++p != '\\')
				map->map_coldelim = *p;
			else
			{
				switch (*++p)
				{
				  case 'n':
					map->map_coldelim = '\n';
					break;

				  case 't':
					map->map_coldelim = '\t';
					break;

				  default:
					map->map_coldelim = '\\';
				}
			}
			break;

		  case 'Z':
			while (isascii(*++p) && isspace(*p))
				continue;
			map->map_sizelimit = atoi(p);
			break;

			/* Start of dns_map specific args */
		  case 'R':		/* search field */
			{
				char *h;

				while (isascii(*++p) && isspace(*p))
					continue;
				h = strchr(p, ' ');
				if (h != NULL)
					*h = '\0';
				map_p->dns_m_type = dns_string_to_type(p);
				if (h != NULL)
					*h = ' ';
				if (map_p->dns_m_type < 0)
					syserr("dns map %s: wrong type %s",
						map->map_mname, p);
			}
			break;

		  case 'B':		/* base domain */
			{
				char *h;

				while (isascii(*++p) && isspace(*p))
					continue;
				h = strchr(p, ' ');
				if (h != NULL)
					*h = '\0';

				/*
				**  slight abuse of map->map_file; it isn't
				**	used otherwise in this map type.
				*/

				map->map_file = newstr(p);
				if (h != NULL)
					*h = ' ';
			}
			break;
		}
		while (*p != '\0' && !(isascii(*p) && isspace(*p)))
			p++;
		if (*p != '\0')
			*p++ = '\0';
	}
	if (map_p->dns_m_type < 0)
		syserr("dns map %s: missing -R type", map->map_mname);
	if (map->map_app != NULL)
		map->map_app = newstr(map->map_app);
	if (map->map_tapp != NULL)
		map->map_tapp = newstr(map->map_tapp);

	/*
	**  Assumption: assert(sizeof(int) <= sizeof(ARBPTR_T));
	**  Even if this assumption is wrong, we use only one byte,
	**  so it doesn't really matter.
	*/

	map->map_db1 = (ARBPTR_T) map_p;
	return true;
}

/*
**  DNS_MAP_LOOKUP -- perform dns map lookup.
**
**	Parameters:
**		map -- pointer to MAP
**		name -- name to lookup
**		av -- arguments to interpolate into buf.
**		statp -- pointer to status (EX_)
**
**	Returns:
**		result of lookup if succeeded.
**		NULL -- otherwise.
*/

char *
dns_map_lookup(map, name, av, statp)
	MAP *map;
	char *name;
	char **av;
	int *statp;
{
	int resnum = 0;
	char *vp = NULL, *result = NULL;
	size_t vsize;
	struct dns_map *map_p;
	RESOURCE_RECORD_T *rr = NULL;
	DNS_REPLY_T *r = NULL;
#  if NETINET6
	static char buf6[INET6_ADDRSTRLEN];
#  endif /* NETINET6 */

	if (tTd(38, 20))
		sm_dprintf("dns_map_lookup(%s, %s)\n",
			   map->map_mname, name);

	map_p = (struct dns_map *)(map->map_db1);
	if (map->map_file != NULL && *map->map_file != '\0')
	{
		size_t len;
		char *appdomain;

		len = strlen(map->map_file) + strlen(name) + 2;
		appdomain = (char *) sm_malloc(len);
		if (appdomain == NULL)
		{
			*statp = EX_UNAVAILABLE;
			return NULL;
		}
		(void) sm_strlcpyn(appdomain, len, 3, name, ".", map->map_file);
		r = dns_lookup_int(appdomain, C_IN, map_p->dns_m_type,
				   map->map_timeout, map->map_retry);
		sm_free(appdomain);
	}
	else
	{
		r = dns_lookup_int(name, C_IN, map_p->dns_m_type,
				   map->map_timeout, map->map_retry);
	}

	if (r == NULL)
	{
		result = NULL;
		if (h_errno == TRY_AGAIN || transienterror(errno))
			*statp = EX_TEMPFAIL;
		else
			*statp = EX_NOTFOUND;
		goto cleanup;
	}
	*statp = EX_OK;
	for (rr = r->dns_r_head; rr != NULL; rr = rr->rr_next)
	{
		char *type = NULL;
		char *value = NULL;

		switch (rr->rr_type)
		{
		  case T_NS:
			type = "T_NS";
			value = rr->rr_u.rr_txt;
			break;
		  case T_CNAME:
			type = "T_CNAME";
			value = rr->rr_u.rr_txt;
			break;
		  case T_AFSDB:
			type = "T_AFSDB";
			value = rr->rr_u.rr_mx->mx_r_domain;
			break;
		  case T_SRV:
			type = "T_SRV";
			value = rr->rr_u.rr_srv->srv_r_target;
			break;
		  case T_PTR:
			type = "T_PTR";
			value = rr->rr_u.rr_txt;
			break;
		  case T_TXT:
			type = "T_TXT";
			value = rr->rr_u.rr_txt;
			break;
		  case T_MX:
			type = "T_MX";
			value = rr->rr_u.rr_mx->mx_r_domain;
			break;
#  if NETINET
		  case T_A:
			type = "T_A";
			value = inet_ntoa(*(rr->rr_u.rr_a));
			break;
#  endif /* NETINET */
#  if NETINET6
		  case T_AAAA:
			type = "T_AAAA";
			value = anynet_ntop(rr->rr_u.rr_aaaa, buf6,
					    sizeof(buf6));
			break;
#  endif /* NETINET6 */
		}

		(void) strreplnonprt(value, 'X');
		if (map_p->dns_m_type != rr->rr_type)
		{
			if (tTd(38, 40))
				sm_dprintf("\tskipping type %s (%d) value %s\n",
					   type != NULL ? type : "<UNKNOWN>",
					   rr->rr_type,
					   value != NULL ? value : "<NO VALUE>");
			continue;
		}

#  if NETINET6
		if (rr->rr_type == T_AAAA && value == NULL)
		{
			result = NULL;
			*statp = EX_DATAERR;
			if (tTd(38, 40))
				sm_dprintf("\tbad T_AAAA conversion\n");
			goto cleanup;
		}
#  endif /* NETINET6 */
		if (tTd(38, 40))
			sm_dprintf("\tfound type %s (%d) value %s\n",
				   type != NULL ? type : "<UNKNOWN>",
				   rr->rr_type,
				   value != NULL ? value : "<NO VALUE>");
		if (value != NULL &&
		    (map->map_coldelim == '\0' ||
		     map->map_sizelimit == 1 ||
		     bitset(MF_MATCHONLY, map->map_mflags)))
		{
			/* Only care about the first match */
			vp = newstr(value);
			break;
		}
		else if (vp == NULL)
		{
			/* First result */
			vp = newstr(value);
		}
		else
		{
			/* concatenate the results */
			int sz;
			char *new;

			sz = strlen(vp) + strlen(value) + 2;
			new = xalloc(sz);
			(void) sm_snprintf(new, sz, "%s%c%s",
					   vp, map->map_coldelim, value);
			sm_free(vp);
			vp = new;
			if (map->map_sizelimit > 0 &&
			    ++resnum >= map->map_sizelimit)
				break;
		}
	}
	if (vp == NULL)
	{
		result = NULL;
		*statp = EX_NOTFOUND;
		if (tTd(38, 40))
			sm_dprintf("\tno match found\n");
		goto cleanup;
	}

	/* Cleanly truncate for rulesets */
	truncate_at_delim(vp, PSBUFSIZE / 2, map->map_coldelim);

	vsize = strlen(vp);

	if (LogLevel > 9)
		sm_syslog(LOG_INFO, CurEnv->e_id, "dns %.100s => %s",
			  name, vp);
	if (bitset(MF_MATCHONLY, map->map_mflags))
		result = map_rewrite(map, name, strlen(name), NULL);
	else
		result = map_rewrite(map, vp, vsize, av);

  cleanup:
	if (vp != NULL)
		sm_free(vp);
	if (r != NULL)
		dns_free_data(r);
	return result;
}
# endif /* DNSMAP */
#endif /* NAMED_BIND */

/*
**  NDBM modules
*/

#if NDBM

/*
**  NDBM_MAP_OPEN -- DBM-style map open
*/

bool
ndbm_map_open(map, mode)
	MAP *map;
	int mode;
{
	register DBM *dbm;
	int save_errno;
	int dfd;
	int pfd;
	long sff;
	int ret;
	int smode = S_IREAD;
	char dirfile[MAXPATHLEN];
	char pagfile[MAXPATHLEN];
	struct stat st;
	struct stat std, stp;

	if (tTd(38, 2))
		sm_dprintf("ndbm_map_open(%s, %s, %d)\n",
			map->map_mname, map->map_file, mode);
	map->map_lockfd = -1;
	mode &= O_ACCMODE;

	/* do initial file and directory checks */
	if (sm_strlcpyn(dirfile, sizeof(dirfile), 2,
			map->map_file, ".dir") >= sizeof(dirfile) ||
	    sm_strlcpyn(pagfile, sizeof(pagfile), 2,
			map->map_file, ".pag") >= sizeof(pagfile))
	{
		errno = 0;
		if (!bitset(MF_OPTIONAL, map->map_mflags))
			syserr("dbm map \"%s\": map file %s name too long",
				map->map_mname, map->map_file);
		return false;
	}
	sff = SFF_ROOTOK|SFF_REGONLY;
	if (mode == O_RDWR)
	{
		sff |= SFF_CREAT;
		if (!bitnset(DBS_WRITEMAPTOSYMLINK, DontBlameSendmail))
			sff |= SFF_NOSLINK;
		if (!bitnset(DBS_WRITEMAPTOHARDLINK, DontBlameSendmail))
			sff |= SFF_NOHLINK;
		smode = S_IWRITE;
	}
	else
	{
		if (!bitnset(DBS_LINKEDMAPINWRITABLEDIR, DontBlameSendmail))
			sff |= SFF_NOWLINK;
	}
	if (!bitnset(DBS_MAPINUNSAFEDIRPATH, DontBlameSendmail))
		sff |= SFF_SAFEDIRPATH;
	ret = safefile(dirfile, RunAsUid, RunAsGid, RunAsUserName,
		       sff, smode, &std);
	if (ret == 0)
		ret = safefile(pagfile, RunAsUid, RunAsGid, RunAsUserName,
			       sff, smode, &stp);

	if (ret != 0)
	{
		char *prob = "unsafe";

		/* cannot open this map */
		if (ret == ENOENT)
			prob = "missing";
		if (tTd(38, 2))
			sm_dprintf("\t%s map file: %d\n", prob, ret);
		if (!bitset(MF_OPTIONAL, map->map_mflags))
			syserr("dbm map \"%s\": %s map file %s",
				map->map_mname, prob, map->map_file);
		return false;
	}
	if (std.st_mode == ST_MODE_NOFILE)
		mode |= O_CREAT|O_EXCL;

# if LOCK_ON_OPEN
	if (mode == O_RDONLY)
		mode |= O_SHLOCK;
	else
		mode |= O_TRUNC|O_EXLOCK;
# else /* LOCK_ON_OPEN */
	if ((mode & O_ACCMODE) == O_RDWR)
	{
#  if NOFTRUNCATE
		/*
		**  Warning: race condition.  Try to lock the file as
		**  quickly as possible after opening it.
		**	This may also have security problems on some systems,
		**	but there isn't anything we can do about it.
		*/

		mode |= O_TRUNC;
#  else /* NOFTRUNCATE */
		/*
		**  This ugly code opens the map without truncating it,
		**  locks the file, then truncates it.  Necessary to
		**  avoid race conditions.
		*/

		int dirfd;
		int pagfd;
		long sff = SFF_CREAT|SFF_OPENASROOT;

		if (!bitnset(DBS_WRITEMAPTOSYMLINK, DontBlameSendmail))
			sff |= SFF_NOSLINK;
		if (!bitnset(DBS_WRITEMAPTOHARDLINK, DontBlameSendmail))
			sff |= SFF_NOHLINK;

		dirfd = safeopen(dirfile, mode, DBMMODE, sff);
		pagfd = safeopen(pagfile, mode, DBMMODE, sff);

		if (dirfd < 0 || pagfd < 0)
		{
			save_errno = errno;
			if (dirfd >= 0)
				(void) close(dirfd);
			if (pagfd >= 0)
				(void) close(pagfd);
			errno = save_errno;
			syserr("ndbm_map_open: cannot create database %s",
				map->map_file);
			return false;
		}
		if (ftruncate(dirfd, (off_t) 0) < 0 ||
		    ftruncate(pagfd, (off_t) 0) < 0)
		{
			save_errno = errno;
			(void) close(dirfd);
			(void) close(pagfd);
			errno = save_errno;
			syserr("ndbm_map_open: cannot truncate %s.{dir,pag}",
				map->map_file);
			return false;
		}

		/* if new file, get "before" bits for later filechanged check */
		if (std.st_mode == ST_MODE_NOFILE &&
		    (fstat(dirfd, &std) < 0 || fstat(pagfd, &stp) < 0))
		{
			save_errno = errno;
			(void) close(dirfd);
			(void) close(pagfd);
			errno = save_errno;
			syserr("ndbm_map_open(%s.{dir,pag}): cannot fstat pre-opened file",
				map->map_file);
			return false;
		}

		/* have to save the lock for the duration (bletch) */
		map->map_lockfd = dirfd;
		(void) close(pagfd);

		/* twiddle bits for dbm_open */
		mode &= ~(O_CREAT|O_EXCL);
#  endif /* NOFTRUNCATE */
	}
# endif /* LOCK_ON_OPEN */

	/* open the database */
	dbm = dbm_open(map->map_file, mode, DBMMODE);
	if (dbm == NULL)
	{
		save_errno = errno;
		if (bitset(MF_ALIAS, map->map_mflags) &&
		    aliaswait(map, ".pag", false))
			return true;
# if !LOCK_ON_OPEN && !NOFTRUNCATE
		if (map->map_lockfd >= 0)
			(void) close(map->map_lockfd);
# endif /* !LOCK_ON_OPEN && !NOFTRUNCATE */
		errno = save_errno;
		if (!bitset(MF_OPTIONAL, map->map_mflags))
			syserr("Cannot open DBM database %s", map->map_file);
		return false;
	}
	dfd = dbm_dirfno(dbm);
	pfd = dbm_pagfno(dbm);
	if (dfd == pfd)
	{
		/* heuristic: if files are linked, this is actually gdbm */
		dbm_close(dbm);
# if !LOCK_ON_OPEN && !NOFTRUNCATE
		if (map->map_lockfd >= 0)
			(void) close(map->map_lockfd);
# endif /* !LOCK_ON_OPEN && !NOFTRUNCATE */
		errno = 0;
		syserr("dbm map \"%s\": cannot support GDBM",
			map->map_mname);
		return false;
	}

	if (filechanged(dirfile, dfd, &std) ||
	    filechanged(pagfile, pfd, &stp))
	{
		save_errno = errno;
		dbm_close(dbm);
# if !LOCK_ON_OPEN && !NOFTRUNCATE
		if (map->map_lockfd >= 0)
			(void) close(map->map_lockfd);
# endif /* !LOCK_ON_OPEN && !NOFTRUNCATE */
		errno = save_errno;
		syserr("ndbm_map_open(%s): file changed after open",
			map->map_file);
		return false;
	}

	map->map_db1 = (ARBPTR_T) dbm;

	/*
	**  Need to set map_mtime before the call to aliaswait()
	**  as aliaswait() will call map_lookup() which requires
	**  map_mtime to be set
	*/

	if (fstat(pfd, &st) >= 0)
		map->map_mtime = st.st_mtime;

	if (mode == O_RDONLY)
	{
# if LOCK_ON_OPEN
		if (dfd >= 0)
			(void) lockfile(dfd, map->map_file, ".dir", LOCK_UN);
		if (pfd >= 0)
			(void) lockfile(pfd, map->map_file, ".pag", LOCK_UN);
# endif /* LOCK_ON_OPEN */
		if (bitset(MF_ALIAS, map->map_mflags) &&
		    !aliaswait(map, ".pag", true))
			return false;
	}
	else
	{
		map->map_mflags |= MF_LOCKED;
		if (geteuid() == 0 && TrustedUid != 0)
		{
#  if HASFCHOWN
			if (fchown(dfd, TrustedUid, -1) < 0 ||
			    fchown(pfd, TrustedUid, -1) < 0)
			{
				int err = errno;

				sm_syslog(LOG_ALERT, NOQID,
					  "ownership change on %s failed: %s",
					  map->map_file, sm_errstring(err));
				message("050 ownership change on %s failed: %s",
					map->map_file, sm_errstring(err));
			}
#  else /* HASFCHOWN */
			sm_syslog(LOG_ALERT, NOQID,
				  "no fchown(): cannot change ownership on %s",
				  map->map_file);
			message("050 no fchown(): cannot change ownership on %s",
				map->map_file);
#  endif /* HASFCHOWN */
		}
	}
	return true;
}


/*
**  NDBM_MAP_LOOKUP -- look up a datum in a DBM-type map
*/

char *
ndbm_map_lookup(map, name, av, statp)
	MAP *map;
	char *name;
	char **av;
	int *statp;
{
	datum key, val;
	int dfd, pfd;
	char keybuf[MAXNAME + 1];
	struct stat stbuf;

	if (tTd(38, 20))
		sm_dprintf("ndbm_map_lookup(%s, %s)\n",
			map->map_mname, name);

	key.dptr = name;
	key.dsize = strlen(name);
	if (!bitset(MF_NOFOLDCASE, map->map_mflags))
	{
		if (key.dsize > sizeof(keybuf) - 1)
			key.dsize = sizeof(keybuf) - 1;
		memmove(keybuf, key.dptr, key.dsize);
		keybuf[key.dsize] = '\0';
		makelower(keybuf);
		key.dptr = keybuf;
	}
lockdbm:
	dfd = dbm_dirfno((DBM *) map->map_db1);
	if (dfd >= 0 && !bitset(MF_LOCKED, map->map_mflags))
		(void) lockfile(dfd, map->map_file, ".dir", LOCK_SH);
	pfd = dbm_pagfno((DBM *) map->map_db1);
	if (pfd < 0 || fstat(pfd, &stbuf) < 0 ||
	    stbuf.st_mtime > map->map_mtime)
	{
		/* Reopen the database to sync the cache */
		int omode = bitset(map->map_mflags, MF_WRITABLE) ? O_RDWR
								 : O_RDONLY;

		if (dfd >= 0 && !bitset(MF_LOCKED, map->map_mflags))
			(void) lockfile(dfd, map->map_file, ".dir", LOCK_UN);
		map->map_mflags |= MF_CLOSING;
		map->map_class->map_close(map);
		map->map_mflags &= ~(MF_OPEN|MF_WRITABLE|MF_CLOSING);
		if (map->map_class->map_open(map, omode))
		{
			map->map_mflags |= MF_OPEN;
			map->map_pid = CurrentPid;
			if ((omode & O_ACCMODE) == O_RDWR)
				map->map_mflags |= MF_WRITABLE;
			goto lockdbm;
		}
		else
		{
			if (!bitset(MF_OPTIONAL, map->map_mflags))
			{
				extern MAPCLASS BogusMapClass;

				*statp = EX_TEMPFAIL;
				map->map_orgclass = map->map_class;
				map->map_class = &BogusMapClass;
				map->map_mflags |= MF_OPEN;
				map->map_pid = CurrentPid;
				syserr("Cannot reopen NDBM database %s",
					map->map_file);
			}
			return NULL;
		}
	}
	val.dptr = NULL;
	if (bitset(MF_TRY0NULL, map->map_mflags))
	{
		val = dbm_fetch((DBM *) map->map_db1, key);
		if (val.dptr != NULL)
			map->map_mflags &= ~MF_TRY1NULL;
	}
	if (val.dptr == NULL && bitset(MF_TRY1NULL, map->map_mflags))
	{
		key.dsize++;
		val = dbm_fetch((DBM *) map->map_db1, key);
		if (val.dptr != NULL)
			map->map_mflags &= ~MF_TRY0NULL;
	}
	if (dfd >= 0 && !bitset(MF_LOCKED, map->map_mflags))
		(void) lockfile(dfd, map->map_file, ".dir", LOCK_UN);
	if (val.dptr == NULL)
		return NULL;
	if (bitset(MF_MATCHONLY, map->map_mflags))
		return map_rewrite(map, name, strlen(name), NULL);
	else
		return map_rewrite(map, val.dptr, val.dsize, av);
}


/*
**  NDBM_MAP_STORE -- store a datum in the database
*/

void
ndbm_map_store(map, lhs, rhs)
	register MAP *map;
	char *lhs;
	char *rhs;
{
	datum key;
	datum data;
	int status;
	char keybuf[MAXNAME + 1];

	if (tTd(38, 12))
		sm_dprintf("ndbm_map_store(%s, %s, %s)\n",
			map->map_mname, lhs, rhs);

	key.dsize = strlen(lhs);
	key.dptr = lhs;
	if (!bitset(MF_NOFOLDCASE, map->map_mflags))
	{
		if (key.dsize > sizeof(keybuf) - 1)
			key.dsize = sizeof(keybuf) - 1;
		memmove(keybuf, key.dptr, key.dsize);
		keybuf[key.dsize] = '\0';
		makelower(keybuf);
		key.dptr = keybuf;
	}

	data.dsize = strlen(rhs);
	data.dptr = rhs;

	if (bitset(MF_INCLNULL, map->map_mflags))
	{
		key.dsize++;
		data.dsize++;
	}

	status = dbm_store((DBM *) map->map_db1, key, data, DBM_INSERT);
	if (status > 0)
	{
		if (!bitset(MF_APPEND, map->map_mflags))
			message("050 Warning: duplicate alias name %s", lhs);
		else
		{
			static char *buf = NULL;
			static int bufsiz = 0;
			auto int xstat;
			datum old;

			old.dptr = ndbm_map_lookup(map, key.dptr,
						   (char **) NULL, &xstat);
			if (old.dptr != NULL && *(char *) old.dptr != '\0')
			{
				old.dsize = strlen(old.dptr);
				if (data.dsize + old.dsize + 2 > bufsiz)
				{
					if (buf != NULL)
						(void) sm_free(buf);
					bufsiz = data.dsize + old.dsize + 2;
					buf = sm_pmalloc_x(bufsiz);
				}
				(void) sm_strlcpyn(buf, bufsiz, 3,
					data.dptr, ",", old.dptr);
				data.dsize = data.dsize + old.dsize + 1;
				data.dptr = buf;
				if (tTd(38, 9))
					sm_dprintf("ndbm_map_store append=%s\n",
						data.dptr);
			}
		}
		status = dbm_store((DBM *) map->map_db1,
				   key, data, DBM_REPLACE);
	}
	if (status != 0)
		syserr("readaliases: dbm put (%s): %d", lhs, status);
}


/*
**  NDBM_MAP_CLOSE -- close the database
*/

void
ndbm_map_close(map)
	register MAP  *map;
{
	if (tTd(38, 9))
		sm_dprintf("ndbm_map_close(%s, %s, %lx)\n",
			map->map_mname, map->map_file, map->map_mflags);

	if (bitset(MF_WRITABLE, map->map_mflags))
	{
# ifdef NDBM_YP_COMPAT
		bool inclnull;
		char buf[MAXHOSTNAMELEN];

		inclnull = bitset(MF_INCLNULL, map->map_mflags);
		map->map_mflags &= ~MF_INCLNULL;

		if (strstr(map->map_file, "/yp/") != NULL)
		{
			long save_mflags = map->map_mflags;

			map->map_mflags |= MF_NOFOLDCASE;

			(void) sm_snprintf(buf, sizeof(buf), "%010ld", curtime());
			ndbm_map_store(map, "YP_LAST_MODIFIED", buf);

			(void) gethostname(buf, sizeof(buf));
			ndbm_map_store(map, "YP_MASTER_NAME", buf);

			map->map_mflags = save_mflags;
		}

		if (inclnull)
			map->map_mflags |= MF_INCLNULL;
# endif /* NDBM_YP_COMPAT */

		/* write out the distinguished alias */
		ndbm_map_store(map, "@", "@");
	}
	dbm_close((DBM *) map->map_db1);

	/* release lock (if needed) */
# if !LOCK_ON_OPEN
	if (map->map_lockfd >= 0)
		(void) close(map->map_lockfd);
# endif /* !LOCK_ON_OPEN */
}

#endif /* NDBM */
/*
**  NEWDB (Hash and BTree) Modules
*/

#if NEWDB

/*
**  BT_MAP_OPEN, HASH_MAP_OPEN -- database open primitives.
**
**	These do rather bizarre locking.  If you can lock on open,
**	do that to avoid the condition of opening a database that
**	is being rebuilt.  If you don't, we'll try to fake it, but
**	there will be a race condition.  If opening for read-only,
**	we immediately release the lock to avoid freezing things up.
**	We really ought to hold the lock, but guarantee that we won't
**	be pokey about it.  That's hard to do.
*/

/* these should be K line arguments */
# if DB_VERSION_MAJOR < 2
#  define db_cachesize	cachesize
#  define h_nelem	nelem
#  ifndef DB_CACHE_SIZE
#   define DB_CACHE_SIZE	(1024 * 1024)	/* database memory cache size */
#  endif /* ! DB_CACHE_SIZE */
#  ifndef DB_HASH_NELEM
#   define DB_HASH_NELEM	4096		/* (starting) size of hash table */
#  endif /* ! DB_HASH_NELEM */
# endif /* DB_VERSION_MAJOR < 2 */

bool
bt_map_open(map, mode)
	MAP *map;
	int mode;
{
# if DB_VERSION_MAJOR < 2
	BTREEINFO btinfo;
# endif /* DB_VERSION_MAJOR < 2 */
# if DB_VERSION_MAJOR == 2
	DB_INFO btinfo;
# endif /* DB_VERSION_MAJOR == 2 */
# if DB_VERSION_MAJOR > 2
	void *btinfo = NULL;
# endif /* DB_VERSION_MAJOR > 2 */

	if (tTd(38, 2))
		sm_dprintf("bt_map_open(%s, %s, %d)\n",
			map->map_mname, map->map_file, mode);

# if DB_VERSION_MAJOR < 3
	memset(&btinfo, '\0', sizeof(btinfo));
#  ifdef DB_CACHE_SIZE
	btinfo.db_cachesize = DB_CACHE_SIZE;
#  endif /* DB_CACHE_SIZE */
# endif /* DB_VERSION_MAJOR < 3 */

	return db_map_open(map, mode, "btree", DB_BTREE, &btinfo);
}

bool
hash_map_open(map, mode)
	MAP *map;
	int mode;
{
# if DB_VERSION_MAJOR < 2
	HASHINFO hinfo;
# endif /* DB_VERSION_MAJOR < 2 */
# if DB_VERSION_MAJOR == 2
	DB_INFO hinfo;
# endif /* DB_VERSION_MAJOR == 2 */
# if DB_VERSION_MAJOR > 2
	void *hinfo = NULL;
# endif /* DB_VERSION_MAJOR > 2 */

	if (tTd(38, 2))
		sm_dprintf("hash_map_open(%s, %s, %d)\n",
			map->map_mname, map->map_file, mode);

# if DB_VERSION_MAJOR < 3
	memset(&hinfo, '\0', sizeof(hinfo));
#  ifdef DB_HASH_NELEM
	hinfo.h_nelem = DB_HASH_NELEM;
#  endif /* DB_HASH_NELEM */
#  ifdef DB_CACHE_SIZE
	hinfo.db_cachesize = DB_CACHE_SIZE;
#  endif /* DB_CACHE_SIZE */
# endif /* DB_VERSION_MAJOR < 3 */

	return db_map_open(map, mode, "hash", DB_HASH, &hinfo);
}

static bool
db_map_open(map, mode, mapclassname, dbtype, openinfo)
	MAP *map;
	int mode;
	char *mapclassname;
	DBTYPE dbtype;
# if DB_VERSION_MAJOR < 2
	const void *openinfo;
# endif /* DB_VERSION_MAJOR < 2 */
# if DB_VERSION_MAJOR == 2
	DB_INFO *openinfo;
# endif /* DB_VERSION_MAJOR == 2 */
# if DB_VERSION_MAJOR > 2
	void **openinfo;
# endif /* DB_VERSION_MAJOR > 2 */
{
	DB *db = NULL;
	int i;
	int omode;
	int smode = S_IREAD;
	int fd;
	long sff;
	int save_errno;
	struct stat st;
	char buf[MAXPATHLEN];

	/* do initial file and directory checks */
	if (sm_strlcpy(buf, map->map_file, sizeof(buf)) >= sizeof(buf))
	{
		errno = 0;
		if (!bitset(MF_OPTIONAL, map->map_mflags))
			syserr("map \"%s\": map file %s name too long",
				map->map_mname, map->map_file);
		return false;
	}
	i = strlen(buf);
	if (i < 3 || strcmp(&buf[i - 3], ".db") != 0)
	{
		if (sm_strlcat(buf, ".db", sizeof(buf)) >= sizeof(buf))
		{
			errno = 0;
			if (!bitset(MF_OPTIONAL, map->map_mflags))
				syserr("map \"%s\": map file %s name too long",
					map->map_mname, map->map_file);
			return false;
		}
	}

	mode &= O_ACCMODE;
	omode = mode;

	sff = SFF_ROOTOK|SFF_REGONLY;
	if (mode == O_RDWR)
	{
		sff |= SFF_CREAT;
		if (!bitnset(DBS_WRITEMAPTOSYMLINK, DontBlameSendmail))
			sff |= SFF_NOSLINK;
		if (!bitnset(DBS_WRITEMAPTOHARDLINK, DontBlameSendmail))
			sff |= SFF_NOHLINK;
		smode = S_IWRITE;
	}
	else
	{
		if (!bitnset(DBS_LINKEDMAPINWRITABLEDIR, DontBlameSendmail))
			sff |= SFF_NOWLINK;
	}
	if (!bitnset(DBS_MAPINUNSAFEDIRPATH, DontBlameSendmail))
		sff |= SFF_SAFEDIRPATH;
	i = safefile(buf, RunAsUid, RunAsGid, RunAsUserName, sff, smode, &st);

	if (i != 0)
	{
		char *prob = "unsafe";

		/* cannot open this map */
		if (i == ENOENT)
			prob = "missing";
		if (tTd(38, 2))
			sm_dprintf("\t%s map file: %s\n", prob, sm_errstring(i));
		errno = i;
		if (!bitset(MF_OPTIONAL, map->map_mflags))
			syserr("%s map \"%s\": %s map file %s",
				mapclassname, map->map_mname, prob, buf);
		return false;
	}
	if (st.st_mode == ST_MODE_NOFILE)
		omode |= O_CREAT|O_EXCL;

	map->map_lockfd = -1;

# if LOCK_ON_OPEN
	if (mode == O_RDWR)
		omode |= O_TRUNC|O_EXLOCK;
	else
		omode |= O_SHLOCK;
# else /* LOCK_ON_OPEN */
	/*
	**  Pre-lock the file to avoid race conditions.  In particular,
	**  since dbopen returns NULL if the file is zero length, we
	**  must have a locked instance around the dbopen.
	*/

	fd = open(buf, omode, DBMMODE);
	if (fd < 0)
	{
		if (!bitset(MF_OPTIONAL, map->map_mflags))
			syserr("db_map_open: cannot pre-open database %s", buf);
		return false;
	}

	/* make sure no baddies slipped in just before the open... */
	if (filechanged(buf, fd, &st))
	{
		save_errno = errno;
		(void) close(fd);
		errno = save_errno;
		syserr("db_map_open(%s): file changed after pre-open", buf);
		return false;
	}

	/* if new file, get the "before" bits for later filechanged check */
	if (st.st_mode == ST_MODE_NOFILE && fstat(fd, &st) < 0)
	{
		save_errno = errno;
		(void) close(fd);
		errno = save_errno;
		syserr("db_map_open(%s): cannot fstat pre-opened file",
			buf);
		return false;
	}

	/* actually lock the pre-opened file */
	if (!lockfile(fd, buf, NULL, mode == O_RDONLY ? LOCK_SH : LOCK_EX))
		syserr("db_map_open: cannot lock %s", buf);

	/* set up mode bits for dbopen */
	if (mode == O_RDWR)
		omode |= O_TRUNC;
	omode &= ~(O_EXCL|O_CREAT);
# endif /* LOCK_ON_OPEN */

# if DB_VERSION_MAJOR < 2
	db = dbopen(buf, omode, DBMMODE, dbtype, openinfo);
# else /* DB_VERSION_MAJOR < 2 */
	{
		int flags = 0;
#  if DB_VERSION_MAJOR > 2
		int ret;
#  endif /* DB_VERSION_MAJOR > 2 */

		if (mode == O_RDONLY)
			flags |= DB_RDONLY;
		if (bitset(O_CREAT, omode))
			flags |= DB_CREATE;
		if (bitset(O_TRUNC, omode))
			flags |= DB_TRUNCATE;
		SM_DB_FLAG_ADD(flags);

#  if DB_VERSION_MAJOR > 2
		ret = db_create(&db, NULL, 0);
#  ifdef DB_CACHE_SIZE
		if (ret == 0 && db != NULL)
		{
			ret = db->set_cachesize(db, 0, DB_CACHE_SIZE, 0);
			if (ret != 0)
			{
				(void) db->close(db, 0);
				db = NULL;
			}
		}
#  endif /* DB_CACHE_SIZE */
#  ifdef DB_HASH_NELEM
		if (dbtype == DB_HASH && ret == 0 && db != NULL)
		{
			ret = db->set_h_nelem(db, DB_HASH_NELEM);
			if (ret != 0)
			{
				(void) db->close(db, 0);
				db = NULL;
			}
		}
#  endif /* DB_HASH_NELEM */
		if (ret == 0 && db != NULL)
		{
			ret = db->open(db,
					DBTXN	/* transaction for DB 4.1 */
					buf, NULL, dbtype, flags, DBMMODE);
			if (ret != 0)
			{
#ifdef DB_OLD_VERSION
				if (ret == DB_OLD_VERSION)
					ret = EINVAL;
#endif /* DB_OLD_VERSION */
				(void) db->close(db, 0);
				db = NULL;
			}
		}
		errno = ret;
#  else /* DB_VERSION_MAJOR > 2 */
		errno = db_open(buf, dbtype, flags, DBMMODE,
				NULL, openinfo, &db);
#  endif /* DB_VERSION_MAJOR > 2 */
	}
# endif /* DB_VERSION_MAJOR < 2 */
	save_errno = errno;

# if !LOCK_ON_OPEN
	if (mode == O_RDWR)
		map->map_lockfd = fd;
	else
		(void) close(fd);
# endif /* !LOCK_ON_OPEN */

	if (db == NULL)
	{
		if (mode == O_RDONLY && bitset(MF_ALIAS, map->map_mflags) &&
		    aliaswait(map, ".db", false))
			return true;
# if !LOCK_ON_OPEN
		if (map->map_lockfd >= 0)
			(void) close(map->map_lockfd);
# endif /* !LOCK_ON_OPEN */
		errno = save_errno;
		if (!bitset(MF_OPTIONAL, map->map_mflags))
			syserr("Cannot open %s database %s",
				mapclassname, buf);
		return false;
	}

# if DB_VERSION_MAJOR < 2
	fd = db->fd(db);
# else /* DB_VERSION_MAJOR < 2 */
	fd = -1;
	errno = db->fd(db, &fd);
# endif /* DB_VERSION_MAJOR < 2 */
	if (filechanged(buf, fd, &st))
	{
		save_errno = errno;
# if DB_VERSION_MAJOR < 2
		(void) db->close(db);
# else /* DB_VERSION_MAJOR < 2 */
		errno = db->close(db, 0);
# endif /* DB_VERSION_MAJOR < 2 */
# if !LOCK_ON_OPEN
		if (map->map_lockfd >= 0)
			(void) close(map->map_lockfd);
# endif /* !LOCK_ON_OPEN */
		errno = save_errno;
		syserr("db