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

/*
* 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"
# include <signal.h>
# include <pwd.h>

#ifndef lint
static char sccsid[] = "@(#)alias.c     8.3 (Berkeley) 7/13/93";
#endif /* not lint */


MAP     *AliasDB[MAXALIASDB + 1];       /* actual database list */
int     NAliasDBs;                      /* number of alias databases */
\f/*
**  ALIAS -- Compute aliases.
**
**      Scans the alias file for an alias for the given address.
**      If found, it arranges to deliver to the alias list instead.
**      Uses libdbm database if -DDBM.
**
**      Parameters:
**              a -- address to alias.
**              sendq -- a pointer to the head of the send queue
**                      to put the aliases in.
**              e -- the current envelope.
**
**      Returns:
**              none
**
**      Side Effects:
**              Aliases found are expanded.
**
**      Deficiencies:
**              It should complain about names that are aliased to
**                      nothing.
*/

alias(a, sendq, e)
       register ADDRESS *a;
       ADDRESS **sendq;
       register ENVELOPE *e;
{
       register char *p;
       int naliases;
       char *owner;
       char obuf[MAXNAME + 6];
       extern char *aliaslookup();

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

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

       if (NoAlias)
               return;

       e->e_to = a->q_paddr;

       /*
       **  Look up this name
       */

       p = aliaslookup(a->q_user, e);
       if (p == NULL)
               return;

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

       if (tTd(27, 1))
               printf("%s (%s, %s) aliased to %s\n",
                   a->q_paddr, a->q_host, a->q_user, p);
       if (bitset(EF_VRFYONLY, e->e_flags))
       {
               a->q_flags |= QVERIFIED;
               e->e_nrcpts++;
               return;
       }
       message("aliased to %s", p);
#ifdef LOG
       if (LogLevel > 9)
               syslog(LOG_INFO, "%s: alias %s => %s", e->e_id, a->q_paddr, p);
#endif
       a->q_flags &= ~QSELFREF;
       AliasLevel++;
       naliases = sendtolist(p, a, sendq, e);
       AliasLevel--;
       if (naliases > 0 && !bitset(QSELFREF, a->q_flags))
       {
               if (tTd(27, 5))
               {
                       printf("alias: QDONTSEND ");
                       printaddr(a, FALSE);
               }
               a->q_flags |= QDONTSEND;
       }

       /*
       **  Look for owner of alias
       */

       (void) strcpy(obuf, "owner-");
       if (strncmp(a->q_user, "owner-", 6) == 0)
               (void) strcat(obuf, "owner");
       else
               (void) strcat(obuf, a->q_user);
       if (!bitnset(M_USR_UPPER, a->q_mailer->m_flags))
               makelower(obuf);
       owner = aliaslookup(obuf, e);
       if (owner != NULL)
       {
               if (strchr(owner, ',') != NULL)
                       owner = obuf;
               a->q_owner = newstr(owner);
       }
}
\f/*
**  ALIASLOOKUP -- look up a name in the alias file.
**
**      Parameters:
**              name -- the name to look up.
**
**      Returns:
**              the value of name.
**              NULL if unknown.
**
**      Side Effects:
**              none.
**
**      Warnings:
**              The return value will be trashed across calls.
*/

char *
aliaslookup(name, e)
       char *name;
       ENVELOPE *e;
{
       register int dbno;
       register MAP *map;
       register char *p;

       for (dbno = 0; dbno < NAliasDBs; dbno++)
       {
               auto int stat;

               map = AliasDB[dbno];
               if (!bitset(MF_OPEN, map->map_mflags))
                       continue;
               p = (*map->map_class->map_lookup)(map, name, NULL, &stat);
               if (p != NULL)
                       return p;
       }
       return NULL;
}
\f/*
**  SETALIAS -- set up an alias map
**
**      Called when reading configuration file.
**
**      Parameters:
**              spec -- the alias specification
**
**      Returns:
**              none.
*/

setalias(spec)
       char *spec;
{
       register char *p;
       register MAP *map;
       char *class;
       STAB *s;

       if (tTd(27, 8))
               printf("setalias(%s)\n", spec);

       for (p = spec; p != NULL; )
       {
               char aname[50];

               while (isspace(*p))
                       p++;
               if (*p == '\0')
                       break;
               spec = p;

               if (NAliasDBs >= MAXALIASDB)
               {
                       syserr("Too many alias databases defined, %d max", MAXALIASDB);
                       return;
               }
               (void) sprintf(aname, "Alias%d", NAliasDBs);
               s = stab(aname, ST_MAP, ST_ENTER);
               map = &s->s_map;
               AliasDB[NAliasDBs] = map;
               bzero(map, sizeof *map);

               p = strpbrk(p, " ,/:");
               if (p != NULL && *p == ':')
               {
                       /* map name */
                       *p++ = '\0';
                       class = spec;
                       spec = p;
               }
               else
               {
                       class = "implicit";
                       map->map_mflags = MF_OPTIONAL|MF_INCLNULL;
               }

               /* find end of spec */
               if (p != NULL)
                       p = strchr(p, ',');
               if (p != NULL)
                       *p++ = '\0';

               /* look up class */
               s = stab(class, ST_MAPCLASS, ST_FIND);
               if (s == NULL)
               {
                       if (tTd(27, 1))
                               printf("Unknown alias class %s\n", class);
               }
               else if (!bitset(MCF_ALIASOK, s->s_mapclass.map_cflags))
               {
                       syserr("setalias: map class %s can't handle aliases",
                               class);
               }
               else
               {
                       map->map_class = &s->s_mapclass;
                       if (map->map_class->map_parse(map, spec))
                       {
                               map->map_mflags |= MF_VALID|MF_ALIAS;
                               NAliasDBs++;
                       }
               }
       }
}
\f/*
**  ALIASWAIT -- wait for distinguished @:@ token to appear.
**
**      This can decide to reopen or rebuild the alias file
*/

aliaswait(map, ext)
       MAP *map;
       char *ext;
{
       int atcnt;
       time_t mtime;
       struct stat stb;
       char buf[MAXNAME];

       if (tTd(27, 3))
               printf("aliaswait(%s:%s)\n",
                       map->map_class->map_cname, map->map_file);

       atcnt = SafeAlias * 2;
       if (atcnt > 0)
       {
               auto int st;

               while (atcnt-- >= 0 &&
                      map->map_class->map_lookup(map, "@", NULL, &st) == NULL)
               {
                       /*
                       **  Close and re-open the alias database in case
                       **  the one is mv'ed instead of cp'ed in.
                       */

                       if (tTd(27, 2))
                               printf("aliaswait: sleeping\n");

                       map->map_class->map_close(map);
                       sleep(30);
                       map->map_class->map_open(map, O_RDONLY);
               }
       }

       /* see if we need to go into auto-rebuild mode */
       if (!bitset(MCF_REBUILDABLE, map->map_class->map_cflags))
       {
               if (tTd(27, 3))
                       printf("aliaswait: not rebuildable\n");
               return;
       }
       if (stat(map->map_file, &stb) < 0)
       {
               if (tTd(27, 3))
                       printf("aliaswait: no source file\n");
               return;
       }
       mtime = stb.st_mtime;
       (void) strcpy(buf, map->map_file);
       if (ext != NULL)
               (void) strcat(buf, ext);
       if (stat(buf, &stb) < 0 || stb.st_mtime < mtime || atcnt < 0)
       {
               /* database is out of date */
               if (AutoRebuild && stb.st_ino != 0 && stb.st_uid == geteuid())
               {
                       message("auto-rebuilding alias database %s", buf);
                       rebuildaliases(map, TRUE);
               }
               else
               {
#ifdef LOG
                       if (LogLevel > 3)
                               syslog(LOG_INFO, "alias database %s out of date",
                                       buf);
#endif /* LOG */
                       message("Warning: alias database %s out of date", buf);
               }
       }
}
\f/*
**  REBUILDALIASES -- rebuild the alias database.
**
**      Parameters:
**              map -- the database to rebuild.
**              automatic -- set if this was automatically generated.
**
**      Returns:
**              none.
**
**      Side Effects:
**              Reads the text version of the database, builds the
**              DBM or DB version.
*/

rebuildaliases(map, automatic)
       register MAP *map;
       bool automatic;
{
       FILE *af;
       void (*oldsigint)();

       if (!bitset(MCF_REBUILDABLE, map->map_class->map_cflags))
               return;

#ifdef LOG
       if (LogLevel > 7)
       {
               syslog(LOG_NOTICE, "alias database %s %srebuilt by %s",
                       map->map_file, automatic ? "auto" : "", username());
       }
#endif /* LOG */

       /* try to lock the source file */
       if ((af = fopen(map->map_file, "r+")) == NULL)
       {
               if (tTd(27, 1))
                       printf("Can't open %s: %s\n",
                               map->map_file, errstring(errno));
               errno = 0;
               return;
       }

       /* see if someone else is rebuilding the alias file */
       if (!lockfile(fileno(af), map->map_file, LOCK_EX|LOCK_NB))
       {
               /* yes, they are -- wait until done */
               message("Alias file %s is already being rebuilt",
                       map->map_file);
               if (OpMode != MD_INITALIAS)
               {
                       /* wait for other rebuild to complete */
                       (void) lockfile(fileno(af), map->map_file,
                                       LOCK_EX);
               }
               (void) fclose(af);
               errno = 0;
               return;
       }

       oldsigint = signal(SIGINT, SIG_IGN);

       if (map->map_class->map_open(map, O_RDWR))
       {
               map->map_mflags |= MF_OPEN|MF_WRITABLE;
               readaliases(map, af, automatic);
       }
       else
       {
               if (tTd(27, 1))
                       printf("Can't create database for %s: %s\n",
                               map->map_file, errstring(errno));
               if (!automatic)
                       syserr("Cannot create database for alias file %s",
                               map->map_file);
       }

       /* close the file, thus releasing locks */
       fclose(af);

       /* add distinguished entries and close the database */
       if (bitset(MF_OPEN, map->map_mflags))
               map->map_class->map_close(map);

       /* restore the old signal */
       (void) signal(SIGINT, oldsigint);
}
\f/*
**  READALIASES -- read and process the alias file.
**
**      This routine implements the part of initaliases that occurs
**      when we are not going to use the DBM stuff.
**
**      Parameters:
**              map -- the alias database descriptor.
**              af -- file to read the aliases from.
**              automatic -- set if this was an automatic rebuild.
**
**      Returns:
**              none.
**
**      Side Effects:
**              Reads aliasfile into the symbol table.
**              Optionally, builds the .dir & .pag files.
*/

readaliases(map, af, automatic)
       register MAP *map;
       FILE *af;
       int automatic;
{
       register char *p;
       char *rhs;
       bool skipping;
       long naliases, bytes, longest;
       ADDRESS al, bl;
       char line[BUFSIZ];

       /*
       **  Read and interpret lines
       */

       FileName = map->map_file;
       LineNumber = 0;
       naliases = bytes = longest = 0;
       skipping = FALSE;
       while (fgets(line, sizeof (line), af) != NULL)
       {
               int lhssize, rhssize;

               LineNumber++;
               p = strchr(line, '\n');
               if (p != NULL)
                       *p = '\0';
               switch (line[0])
               {
                 case '#':
                 case '\0':
                       skipping = FALSE;
                       continue;

                 case ' ':
                 case '\t':
                       if (!skipping)
                               syserr("554 Non-continuation line starts with space");
                       skipping = TRUE;
                       continue;
               }
               skipping = FALSE;

               /*
               **  Process the LHS
               **      Find the colon separator, and parse the address.
               **      It should resolve to a local name -- this will
               **      be checked later (we want to optionally do
               **      parsing of the RHS first to maximize error
               **      detection).
               */

               for (p = line; *p != '\0' && *p != ':' && *p != '\n'; p++)
                       continue;
               if (*p++ != ':')
               {
                       syserr("554 missing colon");
                       continue;
               }
               if (parseaddr(line, &al, 1, ':', NULL, CurEnv) == NULL)
               {
                       syserr("554 illegal alias name");
                       continue;
               }

               /*
               **  Process the RHS.
               **      'al' is the internal form of the LHS address.
               **      'p' points to the text of the RHS.
               */

               while (isascii(*p) && isspace(*p))
                       p++;
               rhs = p;
               for (;;)
               {
                       register char c;
                       register char *nlp;

                       nlp = &p[strlen(p)];
                       if (nlp[-1] == '\n')
                               *--nlp = '\0';

                       if (CheckAliases)
                       {
                               /* do parsing & compression of addresses */
                               while (*p != '\0')
                               {
                                       auto char *delimptr;

                                       while ((isascii(*p) && isspace(*p)) ||
                                                               *p == ',')
                                               p++;
                                       if (*p == '\0')
                                               break;
                                       if (parseaddr(p, &bl, -1, ',', &delimptr, CurEnv) == NULL)
                                               usrerr("553 %s... bad address", p);
                                       p = delimptr;
                               }
                       }
                       else
                       {
                               p = nlp;
                       }

                       /* see if there should be a continuation line */
                       c = fgetc(af);
                       if (!feof(af))
                               (void) ungetc(c, af);
                       if (c != ' ' && c != '\t')
                               break;

                       /* read continuation line */
                       if (fgets(p, sizeof line - (p - line), af) == NULL)
                               break;
                       LineNumber++;

                       /* check for line overflow */
                       if (strchr(p, '\n') == NULL)
                       {
                               usrerr("554 alias too long");
                               break;
                       }
               }
               if (al.q_mailer != LocalMailer)
               {
                       syserr("554 cannot alias non-local names");
                       continue;
               }

               /*
               **  Insert alias into symbol table or DBM file
               */

               if (!bitnset(M_USR_UPPER, al.q_mailer->m_flags))
                       makelower(al.q_user);

               lhssize = strlen(al.q_user);
               rhssize = strlen(rhs);
               map->map_class->map_store(map, al.q_user, rhs);

               if (al.q_paddr != NULL)
                       free(al.q_paddr);
               if (al.q_host != NULL)
                       free(al.q_host);
               if (al.q_user != NULL)
                       free(al.q_user);

               /* statistics */
               naliases++;
               bytes += lhssize + rhssize;
               if (rhssize > longest)
                       longest = rhssize;
       }

       CurEnv->e_to = NULL;
       FileName = NULL;
       if (Verbose || !automatic)
               message("%s: %d aliases, longest %d bytes, %d bytes total",
                       map->map_file, naliases, longest, bytes);
# ifdef LOG
       if (LogLevel > 7)
               syslog(LOG_INFO, "%s: %d aliases, longest %d bytes, %d bytes total",
                       map->map_file, naliases, longest, bytes);
# endif /* LOG */
}
\f/*
**  FORWARD -- Try to forward mail
**
**      This is similar but not identical to aliasing.
**
**      Parameters:
**              user -- the name of the user who's mail we would like
**                      to forward to.  It must have been verified --
**                      i.e., the q_home field must have been filled
**                      in.
**              sendq -- a pointer to the head of the send queue to
**                      put this user's aliases in.
**
**      Returns:
**              none.
**
**      Side Effects:
**              New names are added to send queues.
*/

forward(user, sendq, e)
       ADDRESS *user;
       ADDRESS **sendq;
       register ENVELOPE *e;
{
       char *pp;
       char *ep;
#ifdef HASSETEUID
       register ADDRESS *ca;
       uid_t saveduid, uid;
#endif

       if (tTd(27, 1))
               printf("forward(%s)\n", user->q_paddr);

       if (user->q_mailer != LocalMailer || bitset(QBADADDR, user->q_flags))
               return;
       if (user->q_home == NULL)
       {
               syserr("554 forward: no home");
               user->q_home = "/nosuchdirectory";
       }

       /* good address -- look for .forward file in home */
       define('z', user->q_home, e);
       define('u', user->q_user, e);
       define('h', user->q_host, e);
       if (ForwardPath == NULL)
               ForwardPath = newstr("\201z/.forward");

#ifdef HASSETEUID
       ca = getctladdr(user);
       if (ca != NULL)
               uid = ca->q_uid;
       else
               uid = DefUid;
#endif

       for (pp = ForwardPath; pp != NULL; pp = ep)
       {
               int err;
               char buf[MAXPATHLEN+1];

               ep = strchr(pp, ':');
               if (ep != NULL)
                       *ep = '\0';
               expand(pp, buf, &buf[sizeof buf - 1], e);
               if (ep != NULL)
                       *ep++ = ':';
               if (tTd(27, 3))
                       printf("forward: trying %s\n", buf);

               if (tTd(27, 9))
                       printf("forward: old uid = %d/%d\n", getuid(), geteuid());

#ifdef HASSETEUID
               saveduid = geteuid();
               if (saveduid == 0 && uid != 0)
                       (void) seteuid(uid);
#endif                   

               if (tTd(27, 9))
                       printf("forward: new uid = %d/%d\n", getuid(), geteuid());

               err = include(buf, TRUE, user, sendq, e);

#ifdef HASSETEUID
               if (saveduid == 0 && uid != 0)
                       if (seteuid(saveduid) < 0)
                               syserr("seteuid(%d) failure (real=%d, eff=%d)",
                                       saveduid, getuid(), geteuid());
#endif

               if (tTd(27, 9))
                       printf("forward: reset uid = %d/%d\n", getuid(), geteuid());

               if (err == 0)
                       break;
               if (transienterror(err))
               {
                       /* we have to suspend this message */
                       if (tTd(27, 2))
                               printf("forward: transient error on %s\n", buf);
#ifdef LOG
                       if (LogLevel > 2)
                               syslog(LOG_ERR, "%s: forward %s: transient error: %s",
                                       e->e_id, buf, errstring(err));
#endif
                       message("%s: %s: message queued", buf, errstring(err));
                       user->q_flags |= QQUEUEUP|QDONTSEND;
                       return;
               }
       }
}