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[unix-history] / usr.sbin / sendmail / src / map.c

/*
* Copyright (c) 1992 Eric P. Allman.
* Copyright (c) 1992, 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.
*/

#ifndef lint
static char sccsid[] = "@(#)map.c       8.2 (Berkeley) 7/11/93";
#endif /* not lint */

#include "sendmail.h"

#ifdef NDBM
#include <ndbm.h>
#endif
#ifdef NEWDB
#include <db.h>
#endif
#ifdef NIS
#include <rpcsvc/ypclnt.h>
#endif

/*
**  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 an 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.
*/

#define DBMMODE         0644
\f/*
**  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;

       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_app = ++p;
                       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 (*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)
       {
               syserr("No file name for %s map %s",
                       map->map_class->map_cname, map->map_mname);
               return FALSE;
       }
       return TRUE;
}
\f/*
**  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.
**
**      Side Effects:
**              none.
*/

struct rwbuf
{
       int     rwb_len;        /* size of buffer */
       char    *rwb_buf;       /* ptr to buffer */
};

struct rwbuf    RwBufs[2];      /* buffers for rewriting output */

char *
map_rewrite(map, s, slen, av)
       register MAP *map;
       register char *s;
       int slen;
       char **av;
{
       register char *bp;
       register char c;
       char **avp;
       register char *ap;
       register struct rwbuf *rwb;
       int i;
       int len;

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

       rwb = RwBufs;
       if (av == NULL)
               rwb++;

       /* count expected size of output (can safely overestimate) */
       i = len = slen;
       if (av != NULL)
       {
               bp = s;
               for (i = slen; --i >= 0 && (c = *bp++) != 0; )
               {
                       if (c != '%')
                               continue;
                       if (--i < 0)
                               break;
                       c = *bp++;
                       if (!(isascii(c) && isdigit(c)))
                               continue;
                       c -= 0;
                       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 (rwb->rwb_len < ++len)
       {
               /* need to malloc additional space */
               rwb->rwb_len = len;
               if (rwb->rwb_buf != NULL)
                       free(rwb->rwb_buf);
               rwb->rwb_buf = xalloc(rwb->rwb_len);
       }

       bp = rwb->rwb_buf;
       if (av == NULL)
       {
               bcopy(s, bp, slen);
               bp += slen;
       }
       else
       {
               while (--slen >= 0 && (c = *s++) != '\0')
               {
                       if (c != '%')
                       {
 pushc:
                               *bp++ = c;
                               continue;
                       }
                       if (--slen < 0 || (c = *s++) == '\0')
                               c = '%';
                       if (c == '%')
                               goto pushc;
                       if (!(isascii(c) && isdigit(c)))
                       {
                               *bp++ = '%';
                               goto pushc;
                       }
                       c -= '0';
                       for (avp = av; --c >= 0 && *avp != NULL; avp++)
                               continue;
                       if (*avp == NULL)
                               continue;

                       /* transliterate argument into output string */
                       for (ap = *avp; (c = *ap++) != '\0'; )
                               *bp++ = c;
               }
       }
       if (map->map_app != NULL)
               strcpy(bp, map->map_app);
       else
               *bp = '\0';
       if (tTd(39, 1))
               printf("map_rewrite => %s\n", rwb->rwb_buf);
       return rwb->rwb_buf;
}
\f/*
**  INITMAPS -- initialize for aliasing
**
**      Parameters:
**              rebuild -- if TRUE, this rebuilds the cached versions.
**              e -- current envelope.
**
**      Returns:
**              none.
**
**      Side Effects:
**              initializes aliases:
**              if NDBM:  opens the database.
**              if ~NDBM: reads the aliases into the symbol table.
*/

initmaps(rebuild, e)
       bool rebuild;
       register ENVELOPE *e;
{
       extern void map_init();

       CurEnv = e;
       stabapply(map_init, rebuild);
}

void
map_init(s, rebuild)
       register STAB *s;
       int rebuild;
{
       register MAP *map;

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

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

       if (tTd(38, 2))
               printf("map_init(%s:%s)\n",
                       map->map_class->map_cname, map->map_file);

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

       if (rebuild)
       {
               if (bitset(MF_ALIAS, map->map_mflags) &&
                   bitset(MCF_REBUILDABLE, map->map_class->map_cflags))
                       rebuildaliases(map, FALSE);
       }
       else
       {
               if (map->map_class->map_open(map, O_RDONLY))
               {
                       if (tTd(38, 4))
                               printf("%s:%s: valid\n",
                                       map->map_class->map_cname,
                                       map->map_file);
                       map->map_mflags |= MF_OPEN;
               }
               else if (tTd(38, 4))
                       printf("%s:%s: invalid: %s\n",
                               map->map_class->map_cname,
                               map->map_file,
                               errstring(errno));
       }
}
\f/*
**  NDBM modules
*/

#ifdef NDBM

/*
**  DBM_MAP_OPEN -- DBM-style map open
*/

bool
ndbm_map_open(map, mode)
       MAP *map;
       int mode;
{
       DBM *dbm;

       if (tTd(38, 2))
               printf("ndbm_map_open(%s, %d)\n", map->map_file, mode);

       if (mode == O_RDWR)
               mode |= O_CREAT|O_TRUNC;

       /* open the database */
       dbm = dbm_open(map->map_file, mode, DBMMODE);
       if (dbm == NULL)
       {
               if (!bitset(MF_OPTIONAL, map->map_mflags))
                       syserr("Cannot open DBM database %s", map->map_file);
               return FALSE;
       }
       map->map_db1 = (void *) dbm;
       if (mode == O_RDONLY && bitset(MF_ALIAS, map->map_mflags))
               aliaswait(map, ".pag");
       return TRUE;
}


/*
**  DBM_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;
       char keybuf[MAXNAME + 1];

       if (tTd(38, 20))
               printf("ndbm_map_lookup(%s)\n", 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;
               bcopy(key.dptr, keybuf, key.dsize + 1);
               makelower(keybuf);
               key.dptr = keybuf;
       }
       (void) lockfile(dbm_dirfno((DBM *) map->map_db1), map->map_file, LOCK_SH);
       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;
       }
       (void) lockfile(dbm_dirfno((DBM *) map->map_db1), map->map_file, 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);
}


/*
**  DBM_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 stat;

       if (tTd(38, 12))
               printf("ndbm_map_store(%s, %s)\n", lhs, rhs);

       key.dsize = strlen(lhs);
       key.dptr = lhs;

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

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

       stat = dbm_store((DBM *) map->map_db1, key, data, DBM_INSERT);
       if (stat > 0)
       {
               usrerr("050 Warning: duplicate alias name %s", lhs);
               stat = dbm_store((DBM *) map->map_db1, key, data, DBM_REPLACE);
       }
       if (stat != 0)
               syserr("readaliases: dbm put (%s)", lhs);
}


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

void
ndbm_map_close(map)
       register MAP  *map;
{
       if (bitset(MF_WRITABLE, map->map_mflags))
       {
#ifdef YPCOMPAT
               char buf[200];

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

               (void) myhostname(buf, sizeof buf);
               ndbm_map_store(map, "YP_MASTER_NAME", buf);
#endif

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

#endif
\f/*
**  NEWDB (Hash and BTree) Modules
*/

#ifdef 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.
*/

bool
bt_map_open(map, mode)
       MAP *map;
       int mode;
{
       DB *db;
       int i;
       int omode;
       char buf[MAXNAME];

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

       omode = mode;
       if (omode == O_RDWR)
       {
               omode |= O_CREAT|O_TRUNC;
#if defined(O_EXLOCK) && !defined(LOCKF)
               omode |= O_EXLOCK;
# if !defined(OLD_NEWDB)
       }
       else
       {
               omode |= O_SHLOCK;
# endif
#endif
       }

       (void) strcpy(buf, map->map_file);
       i = strlen(buf);
       if (i < 3 || strcmp(&buf[i - 3], ".db") != 0)
               (void) strcat(buf, ".db");
       db = dbopen(buf, omode, DBMMODE, DB_BTREE, NULL);
       if (db == NULL)
       {
               if (!bitset(MF_OPTIONAL, map->map_mflags))
                       syserr("Cannot open BTREE database %s", map->map_file);
               return FALSE;
       }
#if !defined(OLD_NEWDB) && !defined(LOCKF)
# if !defined(O_EXLOCK)
       if (mode == O_RDWR)
               (void) lockfile(db->fd(db), map->map_file, LOCK_EX);
# else
       if (mode == O_RDONLY)
               (void) lockfile(db->fd(db), map->map_file, LOCK_UN);
# endif
#endif

       /* try to make sure that at least the database header is on disk */
       if (mode == O_RDWR)
               (void) db->sync(db, 0);

       map->map_db2 = (void *) db;
       if (mode == O_RDONLY && bitset(MF_ALIAS, map->map_mflags))
               aliaswait(map, ".db");
       return TRUE;
}


/*
**  HASH_MAP_INIT -- HASH-style map initialization
*/

bool
hash_map_open(map, mode)
       MAP *map;
       int mode;
{
       DB *db;
       int i;
       int omode;
       char buf[MAXNAME];

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

       omode = mode;
       if (omode == O_RDWR)
       {
               omode |= O_CREAT|O_TRUNC;
#if defined(O_EXLOCK) && !defined(LOCKF)
               omode |= O_EXLOCK;
# if !defined(OLD_NEWDB)
       }
       else
       {
               omode |= O_SHLOCK;
# endif
#endif
       }

       (void) strcpy(buf, map->map_file);
       i = strlen(buf);
       if (i < 3 || strcmp(&buf[i - 3], ".db") != 0)
               (void) strcat(buf, ".db");
       db = dbopen(buf, omode, DBMMODE, DB_HASH, NULL);
       if (db == NULL)
       {
               if (!bitset(MF_OPTIONAL, map->map_mflags))
                       syserr("Cannot open HASH database %s", map->map_file);
               return FALSE;
       }
#if !defined(OLD_NEWDB) && !defined(LOCKF)
# if !defined(O_EXLOCK)
       if (mode == O_RDWR)
               (void) lockfile(db->fd(db), map->map_file, LOCK_EX);
# else
       if (mode == O_RDONLY)
               (void) lockfile(db->fd(db), map->map_file, LOCK_UN);
# endif
#endif

       /* try to make sure that at least the database header is on disk */
       if (mode == O_RDWR)
               (void) db->sync(db, 0);

       map->map_db2 = (void *) db;
       if (mode == O_RDONLY && bitset(MF_ALIAS, map->map_mflags))
               aliaswait(map, ".db");
       return TRUE;
}


/*
**  DB_MAP_LOOKUP -- look up a datum in a BTREE- or HASH-type map
*/

char *
db_map_lookup(map, name, av, statp)
       MAP *map;
       char *name;
       char **av;
       int *statp;
{
       DBT key, val;
       register DB *db = (DB *) map->map_db2;
       int st;
       int saveerrno;
       char keybuf[MAXNAME + 1];

       if (tTd(38, 20))
               printf("db_map_lookup(%s)\n", name);

       key.size = strlen(name);
       if (key.size > sizeof keybuf - 1)
               key.size = sizeof keybuf - 1;
       key.data = keybuf;
       bcopy(name, keybuf, key.size + 1);
       if (!bitset(MF_NOFOLDCASE, map->map_mflags))
               makelower(keybuf);
#ifndef OLD_NEWDB
       (void) lockfile(db->fd(db), map->map_file, LOCK_SH);
#endif
       st = 1;
       if (bitset(MF_TRY0NULL, map->map_mflags))
       {
               st = db->get(db, &key, &val, 0);
               if (st == 0)
                       map->map_mflags &= ~MF_TRY1NULL;
       }
       if (st != 0 && bitset(MF_TRY1NULL, map->map_mflags))
       {
               key.size++;
               st = db->get(db, &key, &val, 0);
               if (st == 0)
                       map->map_mflags &= ~MF_TRY0NULL;
       }
       saveerrno = errno;
#ifndef OLD_NEWDB
       (void) lockfile(db->fd(db), map->map_file, LOCK_UN);
#endif
       if (st != 0)
       {
               errno = saveerrno;
               if (st < 0)
                       syserr("db_map_lookup: get (%s)", name);
               return NULL;
       }
       if (bitset(MF_MATCHONLY, map->map_mflags))
               return map_rewrite(map, name, strlen(name), NULL);
       else
               return map_rewrite(map, val.data, val.size, av);
}


/*
**  DB_MAP_STORE -- store a datum in the NEWDB database
*/

void
db_map_store(map, lhs, rhs)
       register MAP *map;
       char *lhs;
       char *rhs;
{
       int stat;
       DBT key;
       DBT data;
       register DB *db = map->map_db2;

       if (tTd(38, 20))
               printf("db_map_store(%s, %s)\n", lhs, rhs);

       key.size = strlen(lhs);
       key.data = lhs;

       data.size = strlen(rhs);
       data.data = rhs;

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

       stat = db->put(db, &key, &data, R_NOOVERWRITE);
       if (stat > 0)
       {
               usrerr("050 Warning: duplicate alias name %s", lhs);
               stat = db->put(db, &key, &data, 0);
       }
       if (stat != 0)
               syserr("readaliases: db put (%s)", lhs);
}


/*
**  DB_MAP_CLOSE -- add distinguished entries and close the database
*/

void
db_map_close(map)
       MAP *map;
{
       register DB *db = map->map_db2;

       if (tTd(38, 9))
               printf("db_map_close(%s, %x)\n", map->map_file, map->map_mflags);

       if (bitset(MF_WRITABLE, map->map_mflags))
       {
               /* write out the distinguished alias */
               db_map_store(map, "@", "@");
       }

       if (db->close(db) != 0)
               syserr("readaliases: db close failure");
}

#endif
\f/*
**  NIS Modules
*/

# ifdef NIS

/*
**  NIS_MAP_OPEN -- open DBM map
*/

bool
nis_map_open(map, mode)
       MAP *map;
       int mode;
{
       int yperr;
       register char *p;
       auto char *vp;
       auto int vsize;
       char *master;

       if (tTd(38, 2))
               printf("nis_map_open(%s)\n", map->map_file);

       if (mode != O_RDONLY)
       {
               errno = ENODEV;
               return FALSE;
       }

       p = strchr(map->map_file, '@');
       if (p != NULL)
       {
               *p++ = '\0';
               if (*p != '\0')
                       map->map_domain = p;
       }

       if (map->map_domain == NULL)
               yp_get_default_domain(&map->map_domain);

       if (*map->map_file == '\0')
               map->map_file = "mail.aliases";

       /* check to see if this map actually exists */
       yperr = yp_match(map->map_domain, map->map_file, "@", 1,
                       &vp, &vsize);
       if (tTd(38, 10))
               printf("nis_map_open: yp_match(%s, %s) => %s\n",
                       map->map_domain, map->map_file, yperr_string(yperr));
       if (yperr == 0 || yperr == YPERR_KEY || yperr == YPERR_BUSY)
               return TRUE;

       if (!bitset(MF_OPTIONAL, map->map_mflags))
               syserr("Cannot bind to domain %s: %s", map->map_domain,
                       yperr_string(yperr));

       return FALSE;
}


/*
**  NIS_MAP_LOOKUP -- look up a datum in a NIS map
*/

char *
nis_map_lookup(map, name, av, statp)
       MAP *map;
       char *name;
       char **av;
       int *statp;
{
       char *vp;
       auto int vsize;
       int buflen;
       int yperr;
       char keybuf[MAXNAME + 1];

       if (tTd(38, 20))
               printf("nis_map_lookup(%s)\n", name);

       buflen = strlen(name);
       if (buflen > sizeof keybuf - 1)
               buflen = sizeof keybuf - 1;
       bcopy(name, keybuf, buflen + 1);
       if (!bitset(MF_NOFOLDCASE, map->map_mflags))
               makelower(keybuf);
       yperr = YPERR_KEY;
       if (bitset(MF_TRY0NULL, map->map_mflags))
       {
               yperr = yp_match(map->map_domain, map->map_file, keybuf, buflen,
                            &vp, &vsize);
               if (yperr == 0)
                       map->map_mflags &= ~MF_TRY1NULL;
       }
       if (yperr == YPERR_KEY && bitset(MF_TRY1NULL, map->map_mflags))
       {
               buflen++;
               yperr = yp_match(map->map_domain, map->map_file, keybuf, buflen,
                            &vp, &vsize);
               if (yperr == 0)
                       map->map_mflags &= ~MF_TRY0NULL;
       }
       if (yperr != 0)
       {
               if (yperr != YPERR_KEY && yperr != YPERR_BUSY)
                       map->map_mflags &= ~(MF_VALID|MF_OPEN);
               return NULL;
       }
       if (bitset(MF_MATCHONLY, map->map_mflags))
               return map_rewrite(map, name, strlen(name), NULL);
       else
               return map_rewrite(map, vp, vsize, av);
}


/*
**  NIS_MAP_STORE
*/

void
nis_map_store(map, lhs, rhs)
       MAP *map;
       char *lhs;
       char *rhs;
{
       /* nothing */
}


/*
**  NIS_MAP_CLOSE
*/

void
nis_map_close(map)
       MAP *map;
{
       /* nothing */
}

#endif /* NIS */
\f/*
**  STAB (Symbol Table) Modules
*/


/*
**  STAB_MAP_LOOKUP -- look up alias in symbol table
*/

char *
stab_map_lookup(map, name, av, pstat)
       register MAP *map;
       char *name;
       char **av;
       int *pstat;
{
       register STAB *s;

       if (tTd(38, 20))
               printf("stab_lookup(%s)\n", name);

       s = stab(name, ST_ALIAS, ST_FIND);
       if (s != NULL)
               return (s->s_alias);
       return (NULL);
}


/*
**  STAB_MAP_STORE -- store in symtab (actually using during init, not rebuild)
*/

void
stab_map_store(map, lhs, rhs)
       register MAP *map;
       char *lhs;
       char *rhs;
{
       register STAB *s;

       s = stab(lhs, ST_ALIAS, ST_ENTER);
       s->s_alias = newstr(rhs);
}


/*
**  STAB_MAP_OPEN -- initialize (reads data file)
**
**      This is a wierd case -- it is only intended as a fallback for
**      aliases.  For this reason, opens for write (only during a
**      "newaliases") always fails, and opens for read open the
**      actual underlying text file instead of the database.
*/

bool
stab_map_open(map, mode)
       register MAP *map;
       int mode;
{
       if (tTd(38, 2))
               printf("stab_map_open(%s)\n", map->map_file);

       if (mode != O_RDONLY)
       {
               errno = ENODEV;
               return FALSE;
       }

       return TRUE;
}


/*
**  STAB_MAP_CLOSE -- close symbol table (???)
*/

void
stab_map_close(map)
       MAP *map;
{
       /* ignore it */
}
\f/*
**  Implicit Modules
**
**      Tries several types.  For back compatibility of aliases.
*/


/*
**  IMPL_MAP_LOOKUP -- lookup in best open database
*/

char *
impl_map_lookup(map, name, av, pstat)
       MAP *map;
       char *name;
       char **av;
       int *pstat;
{
       if (tTd(38, 20))
               printf("impl_map_lookup(%s)\n", name);

#ifdef NEWDB
       if (bitset(MF_IMPL_HASH, map->map_mflags))
               return db_map_lookup(map, name, av, pstat);
#endif
#ifdef NDBM
       if (bitset(MF_IMPL_NDBM, map->map_mflags))
               return ndbm_map_lookup(map, name, av, pstat);
#endif
       return stab_map_lookup(map, name, av, pstat);
}

/*
**  IMPL_MAP_STORE -- store in open databases
*/

void
impl_map_store(map, lhs, rhs)
       MAP *map;
       char *lhs;
       char *rhs;
{
#ifdef NEWDB
       if (bitset(MF_IMPL_HASH, map->map_mflags))
               db_map_store(map, lhs, rhs);
#endif
#ifdef NDBM
       if (bitset(MF_IMPL_NDBM, map->map_mflags))
               ndbm_map_store(map, lhs, rhs);
#endif
       stab_map_store(map, lhs, rhs);
}

/*
**  IMPL_MAP_OPEN -- implicit database open
*/

bool
impl_map_open(map, mode)
       MAP *map;
       int mode;
{
       struct stat stb;

       if (tTd(38, 2))
               printf("impl_map_open(%s)\n", map->map_file);

       if (stat(map->map_file, &stb) < 0)
       {
               /* no alias file at all */
               return FALSE;
       }

#ifdef NEWDB
       map->map_mflags |= MF_IMPL_HASH;
       if (hash_map_open(map, mode))
       {
#if defined(NDBM) && defined(YPCOMPAT)
               if (mode == O_RDONLY || access("/var/yp/Makefile", R_OK) != 0)
#endif
                       return TRUE;
       }
       else
               map->map_mflags &= ~MF_IMPL_HASH;
#endif
#ifdef NDBM
       map->map_mflags |= MF_IMPL_NDBM;
       if (ndbm_map_open(map, mode))
       {
               return TRUE;
       }
       else
               map->map_mflags &= ~MF_IMPL_NDBM;
#endif

#if !defined(NEWDB) && !defined(NDBM)
       if (Verbose)
               message("WARNING: cannot open alias database %s", map->map_file);
#endif

       return stab_map_open(map, mode);
}


/*
**  IMPL_MAP_CLOSE -- close any open database(s)
*/

void
impl_map_close(map)
       MAP *map;
{
#ifdef NEWDB
       if (bitset(MF_IMPL_HASH, map->map_mflags))
       {
               db_map_close(map);
               map->map_mflags &= ~MF_IMPL_HASH;
       }
#endif

#ifdef NDBM
       if (bitset(MF_IMPL_NDBM, map->map_mflags))
       {
               ndbm_map_close(map);
               map->map_mflags &= ~MF_IMPL_NDBM;
       }
#endif
}
\f/*
**  NULL stubs
*/

bool
null_map_open(map, mode)
       MAP *map;
       int mode;
{
       return TRUE;
}

void
null_map_close(map)
       MAP *map;
{
       return;
}

void
null_map_store(map, key, val)
       MAP *map;
       char *key;
       char *val;
{
       return;
}