sendmail/src/udb.c

/*
 * Copyright (c) 1998-2003, 2006 Sendmail, Inc. and its suppliers.
 *  All rights reserved.
 * Copyright (c) 1983, 1995-1997 Eric P. Allman.  All rights reserved.
 * Copyright (c) 1988, 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.
 *
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

#include <sendmail.h>
#include "map.h"

#if USERDB
SM_RCSID("@(#)$Id: udb.c,v 8.164 2006/12/19 19:49:51 ca Exp $ (with USERDB)")
#else /* USERDB */
SM_RCSID("@(#)$Id: udb.c,v 8.164 2006/12/19 19:49:51 ca Exp $ (without USERDB)")
#endif /* USERDB */

#if USERDB

#include <sm/sendmail.h>
# if NEWDB
#  include "sm/bdb.h"
# else /* NEWDB */
#  define DBT   struct _data_base_thang_
DBT
{
    void    *data;      /* pointer to data */
    size_t  size;       /* length of data */
};
# endif /* NEWDB */

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


struct udbent
{
    char    *udb_spec;      /* string version of spec */
    int udb_type;       /* type of entry */
    pid_t   udb_pid;        /* PID of process which opened db */
    char    *udb_default;       /* default host for outgoing mail */
    union
    {
# if NETINET || NETINET6
        /* type UE_REMOTE -- do remote call for lookup */
        struct
        {
            SOCKADDR    _udb_addr;  /* address */
            int     _udb_timeout;   /* timeout */
        } udb_remote;
#  define udb_addr  udb_u.udb_remote._udb_addr
#  define udb_timeout   udb_u.udb_remote._udb_timeout
# endif /* NETINET || NETINET6 */

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

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

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

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


struct udb_option
{
    char    *udbo_name;
    char    *udbo_val;
};

# if HESIOD
static int  hes_udb_get __P((DBT *, DBT *));
# endif /* HESIOD */
static char *udbmatch __P((char *, char *, SM_RPOOL_T *));
static int  _udbx_init __P((ENVELOPE *));
static int  _udb_parsespec __P((char *, struct udb_option [], int));

/*
**  UDBEXPAND -- look up user in database and expand
**
**  Parameters:
**      a -- address to expand.
**      sendq -- pointer to head of sendq to put the expansions in.
**      aliaslevel -- the current alias nesting depth.
**      e -- the current envelope.
**
**  Returns:
**      EX_TEMPFAIL -- if something "odd" happened -- probably due
**          to accessing a file on an NFS server that is down.
**      EX_OK -- otherwise.
**
**  Side Effects:
**      Modifies sendq.
*/

static struct udbent    UdbEnts[MAXUDBENT + 1];
static bool     UdbInitialized = false;

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

    memset(&key, '\0', sizeof(key));
    memset(&info, '\0', sizeof(info));

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

    /* make certain we are supposed to send to this address */
    if (!QS_IS_SENDABLE(a->q_state))
        return EX_OK;
    e->e_to = a->q_paddr;

    /* on first call, locate the database */
    if (!UdbInitialized)
    {
        if (_udbx_init(e) == EX_TEMPFAIL)
            return EX_TEMPFAIL;
    }

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

    /* extract user to do userdb matching on */
    user = a->q_user;

    /* short circuit name begins with '\\' since it can't possibly match */
    /* (might want to treat this as unquoted instead) */
    if (user[0] == '\\')
        return EX_OK;

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

    keylen = sm_strlcpyn(keybuf, sizeof(keybuf), 2, user, ":maildrop");

    /* if name is too long, assume it won't match */
    if (keylen >= sizeof(keybuf))
        return EX_OK;

    /* build actual database key */

    breakout = false;
    for (up = UdbEnts; !breakout; up++)
    {
        int usersize;
        int userleft;
        char userbuf[MEMCHUNKSIZE];
# if HESIOD && HES_GETMAILHOST
        char pobuf[MAXNAME];
# endif /* HESIOD && HES_GETMAILHOST */
# if defined(NEWDB) && DB_VERSION_MAJOR > 1
        DBC *dbc = NULL;
# endif /* defined(NEWDB) && DB_VERSION_MAJOR > 1 */

        user = userbuf;
        userbuf[0] = '\0';
        usersize = sizeof(userbuf);
        userleft = sizeof(userbuf) - 1;

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

        switch (up->udb_type)
        {
# if NEWDB
          case UDB_DBFETCH:
            key.data = keybuf;
            key.size = keylen;
            if (tTd(28, 80))
                sm_dprintf("udbexpand: trying %s (%d) via db\n",
                    keybuf, keylen);
#  if DB_VERSION_MAJOR < 2
            i = (*up->udb_dbp->seq)(up->udb_dbp, &key, &info, R_CURSOR);
#  else /* DB_VERSION_MAJOR < 2 */
            i = 0;
            if (dbc == NULL &&
#   if DB_VERSION_MAJOR > 2 || DB_VERSION_MINOR >= 6
                (errno = (*up->udb_dbp->cursor)(up->udb_dbp,
                                NULL, &dbc, 0)) != 0)
#   else /* DB_VERSION_MAJOR > 2 || DB_VERSION_MINOR >= 6 */
                (errno = (*up->udb_dbp->cursor)(up->udb_dbp,
                                NULL, &dbc)) != 0)
#   endif /* DB_VERSION_MAJOR > 2 || DB_VERSION_MINOR >= 6 */
                i = -1;
            if (i != 0 || dbc == NULL ||
                (errno = dbc->c_get(dbc, &key,
                        &info, DB_SET)) != 0)
                i = 1;
#  endif /* DB_VERSION_MAJOR < 2 */
            if (i > 0 || info.size <= 0)
            {
                if (tTd(28, 2))
                    sm_dprintf("udbexpand: no match on %s (%d)\n",
                        keybuf, keylen);
#  if DB_VERSION_MAJOR > 1
                if (dbc != NULL)
                {
                    (void) dbc->c_close(dbc);
                    dbc = NULL;
                }
#  endif /* DB_VERSION_MAJOR > 1 */
                break;
            }
            if (tTd(28, 80))
                sm_dprintf("udbexpand: match %.*s: %.*s\n",
                    (int) key.size, (char *) key.data,
                    (int) info.size, (char *) info.data);

            a->q_flags &= ~QSELFREF;
            while (i == 0 && key.size == keylen &&
                   memcmp(key.data, keybuf, keylen) == 0)
            {
                char *p;

                if (bitset(EF_VRFYONLY, e->e_flags))
                {
                    a->q_state = QS_VERIFIED;
#  if DB_VERSION_MAJOR > 1
                    if (dbc != NULL)
                    {
                        (void) dbc->c_close(dbc);
                        dbc = NULL;
                    }
#  endif /* DB_VERSION_MAJOR > 1 */
                    return EX_OK;
                }

                breakout = true;
                if (info.size >= userleft - 1)
                {
                    char *nuser;
                    int size = MEMCHUNKSIZE;

                    if (info.size > MEMCHUNKSIZE)
                        size = info.size;
                    nuser = sm_malloc_x(usersize + size);

                    memmove(nuser, user, usersize);
                    if (user != userbuf)
                        sm_free(user); /* XXX */
                    user = nuser;
                    usersize += size;
                    userleft += size;
                }
                p = &user[strlen(user)];
                if (p != user)
                {
                    *p++ = ',';
                    userleft--;
                }
                memmove(p, info.data, info.size);
                p[info.size] = '\0';
                userleft -= info.size;

                /* get the next record */
#  if DB_VERSION_MAJOR < 2
                i = (*up->udb_dbp->seq)(up->udb_dbp, &key, &info, R_NEXT);
#  else /* DB_VERSION_MAJOR < 2 */
                i = 0;
                if ((errno = dbc->c_get(dbc, &key,
                            &info, DB_NEXT)) != 0)
                    i = 1;
#  endif /* DB_VERSION_MAJOR < 2 */
            }

#  if DB_VERSION_MAJOR > 1
            if (dbc != NULL)
            {
                (void) dbc->c_close(dbc);
                dbc = NULL;
            }
#  endif /* DB_VERSION_MAJOR > 1 */

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

            message("expanded to %s", user);
            if (LogLevel > 10)
                sm_syslog(LOG_INFO, e->e_id,
                      "expand %.100s => %s",
                      e->e_to,
                      shortenstring(user, MAXSHORTSTR));
            naddrs = sendtolist(user, a, sendq, aliaslevel + 1, e);
            if (naddrs > 0 && !bitset(QSELFREF, a->q_flags))
            {
                if (tTd(28, 5))
                {
                    sm_dprintf("udbexpand: QS_EXPANDED ");
                    printaddr(sm_debug_file(), a, false);
                }
                a->q_state = QS_EXPANDED;
            }
            if (i < 0)
            {
                syserr("udbexpand: db-get %.*s stat %d",
                    (int) key.size, (char *) key.data, i);
                return EX_TEMPFAIL;
            }

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

            memset(&key, '\0', sizeof(key));
            memset(&info, '\0', sizeof(info));
            (void) sm_strlcpyn(keybuf, sizeof(keybuf), 2, a->q_user,
                       ":mailsender");
            keylen = strlen(keybuf);
            key.data = keybuf;
            key.size = keylen;

#  if DB_VERSION_MAJOR < 2
            i = (*up->udb_dbp->get)(up->udb_dbp, &key, &info, 0);
#  else /* DB_VERSION_MAJOR < 2 */
            i = errno = (*up->udb_dbp->get)(up->udb_dbp, NULL,
                            &key, &info, 0);
#  endif /* DB_VERSION_MAJOR < 2 */
            if (i != 0 || info.size <= 0)
                break;
            a->q_owner = sm_rpool_malloc_x(e->e_rpool,
                               info.size + 1);
            memmove(a->q_owner, info.data, info.size);
            a->q_owner[info.size] = '\0';

            /* announce delivery; NORECEIPT bit set later */
            if (e->e_xfp != NULL)
            {
                (void) sm_io_fprintf(e->e_xfp, SM_TIME_DEFAULT,
                             "Message delivered to mailing list %s\n",
                             a->q_paddr);
            }
            e->e_flags |= EF_SENDRECEIPT;
            a->q_flags |= QDELIVERED|QEXPANDED;
            break;
# endif /* NEWDB */

# if HESIOD
          case UDB_HESIOD:
            key.data = keybuf;
            key.size = keylen;
            if (tTd(28, 80))
                sm_dprintf("udbexpand: trying %s (%d) via hesiod\n",
                    keybuf, keylen);
            /* look up the key via hesiod */
            i = hes_udb_get(&key, &info);
            if (i < 0)
            {
                syserr("udbexpand: hesiod-get %.*s stat %d",
                    (int) key.size, (char *) key.data, i);
                return EX_TEMPFAIL;
            }
            else if (i > 0 || info.size <= 0)
            {
#  if HES_GETMAILHOST
                struct hes_postoffice *hp;
#  endif /* HES_GETMAILHOST */

                if (tTd(28, 2))
                    sm_dprintf("udbexpand: no match on %s (%d)\n",
                        (char *) keybuf, (int) keylen);
#  if HES_GETMAILHOST
                if (tTd(28, 8))
                    sm_dprintf("  ... trying hes_getmailhost(%s)\n",
                        a->q_user);
                hp = hes_getmailhost(a->q_user);
                if (hp == NULL)
                {
                    if (hes_error() == HES_ER_NET)
                    {
                        syserr("udbexpand: hesiod-getmail %s stat %d",
                            a->q_user, hes_error());
                        return EX_TEMPFAIL;
                    }
                    if (tTd(28, 2))
                        sm_dprintf("hes_getmailhost(%s): %d\n",
                            a->q_user, hes_error());
                    break;
                }
                if (strlen(hp->po_name) + strlen(hp->po_host) >
                    sizeof(pobuf) - 2)
                {
                    if (tTd(28, 2))
                        sm_dprintf("hes_getmailhost(%s): expansion too long: %.30s@%.30s\n",
                            a->q_user,
                            hp->po_name,
                            hp->po_host);
                    break;
                }
                info.data = pobuf;
                (void) sm_snprintf(pobuf, sizeof(pobuf),
                    "%s@%s", hp->po_name, hp->po_host);
                info.size = strlen(info.data);
#  else /* HES_GETMAILHOST */
                break;
#  endif /* HES_GETMAILHOST */
            }
            if (tTd(28, 80))
                sm_dprintf("udbexpand: match %.*s: %.*s\n",
                    (int) key.size, (char *) key.data,
                    (int) info.size, (char *) info.data);
            a->q_flags &= ~QSELFREF;

            if (bitset(EF_VRFYONLY, e->e_flags))
            {
                a->q_state = QS_VERIFIED;
                return EX_OK;
            }

            breakout = true;
            if (info.size >= usersize)
                user = sm_malloc_x(info.size + 1);
            memmove(user, info.data, info.size);
            user[info.size] = '\0';

            message("hesioded to %s", user);
            if (LogLevel > 10)
                sm_syslog(LOG_INFO, e->e_id,
                      "hesiod %.100s => %s",
                      e->e_to,
                      shortenstring(user, MAXSHORTSTR));
            naddrs = sendtolist(user, a, sendq, aliaslevel + 1, e);

            if (naddrs > 0 && !bitset(QSELFREF, a->q_flags))
            {
                if (tTd(28, 5))
                {
                    sm_dprintf("udbexpand: QS_EXPANDED ");
                    printaddr(sm_debug_file(), a, false);
                }
                a->q_state = QS_EXPANDED;
            }

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

            (void) sm_strlcpyn(keybuf, sizeof(keybuf), 2, a->q_user,
                       ":mailsender");
            keylen = strlen(keybuf);
            key.data = keybuf;
            key.size = keylen;
            i = hes_udb_get(&key, &info);
            if (i != 0 || info.size <= 0)
                break;
            a->q_owner = sm_rpool_malloc_x(e->e_rpool,
                               info.size + 1);
            memmove(a->q_owner, info.data, info.size);
            a->q_owner[info.size] = '\0';
            break;
# endif /* HESIOD */

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

          case UDB_FORWARD:
            if (bitset(EF_VRFYONLY, e->e_flags))
            {
                a->q_state = QS_VERIFIED;
                return EX_OK;
            }
            i = strlen(up->udb_fwdhost) + strlen(a->q_user) + 1;
            if (i >= usersize)
            {
                usersize = i + 1;
                user = sm_malloc_x(usersize);
            }
            (void) sm_strlcpyn(user, usersize, 3,
                    a->q_user, "@", up->udb_fwdhost);
            message("expanded to %s", user);
            a->q_flags &= ~QSELFREF;
            naddrs = sendtolist(user, a, sendq, aliaslevel + 1, e);
            if (naddrs > 0 && !bitset(QSELFREF, a->q_flags))
            {
                if (tTd(28, 5))
                {
                    sm_dprintf("udbexpand: QS_EXPANDED ");
                    printaddr(sm_debug_file(), a, false);
                }
                a->q_state = QS_EXPANDED;
            }
            breakout = true;
            break;

          case UDB_EOLIST:
            breakout = true;
            break;

          default:
            /* unknown entry type */
            break;
        }
        /* XXX if an exception occurs, there is a storage leak */
        if (user != userbuf)
            sm_free(user); /* XXX */
    }
    return EX_OK;
}
/*
**  UDBSENDER -- return canonical external name of sender, given local name
**
**  Parameters:
**      sender -- the name of the sender on the local machine.
**      rpool -- resource pool from which to allocate result
**
**  Returns:
**      The external name for this sender, if derivable from the
**          database.  Storage allocated from rpool.
**      NULL -- if nothing is changed from the database.
**
**  Side Effects:
**      none.
*/

char *
udbsender(sender, rpool)
    char *sender;
    SM_RPOOL_T *rpool;
{
    return udbmatch(sender, "mailname", rpool);
}
/*
**  UDBMATCH -- match user in field, return result of lookup.
**
**  Parameters:
**      user -- the name of the user.
**      field -- the field to lookup.
**      rpool -- resource pool from which to allocate result
**
**  Returns:
**      The external name for this sender, if derivable from the
**          database.  Storage allocated from rpool.
**      NULL -- if nothing is changed from the database.
**
**  Side Effects:
**      none.
*/

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

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

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

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

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

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

    /* names beginning with colons indicate metadata */
    if (user[0] == ':')
        return NULL;

    /* build database key */
    (void) sm_strlcpyn(keybuf, sizeof(keybuf), 3, user, ":", field);
    keylen = strlen(keybuf);

    for (up = UdbEnts; up->udb_type != UDB_EOLIST; up++)
    {
        /*
        **  Select action based on entry type.
        */

        switch (up->udb_type)
        {
# if NEWDB
          case UDB_DBFETCH:
            memset(&key, '\0', sizeof(key));
            memset(&info, '\0', sizeof(info));
            key.data = keybuf;
            key.size = keylen;
#  if DB_VERSION_MAJOR < 2
            i = (*up->udb_dbp->get)(up->udb_dbp, &key, &info, 0);
#  else /* DB_VERSION_MAJOR < 2 */
            i = errno = (*up->udb_dbp->get)(up->udb_dbp, NULL,
                            &key, &info, 0);
#  endif /* DB_VERSION_MAJOR < 2 */
            if (i != 0 || info.size <= 0)
            {
                if (tTd(28, 2))
                    sm_dprintf("udbmatch: no match on %s (%d) via db\n",
                        keybuf, keylen);
                continue;
            }

            p = sm_rpool_malloc_x(rpool, info.size + 1);
            memmove(p, info.data, info.size);
            p[info.size] = '\0';
            if (tTd(28, 1))
                sm_dprintf("udbmatch ==> %s\n", p);
            return p;
# endif /* NEWDB */

# if HESIOD
          case UDB_HESIOD:
            key.data = keybuf;
            key.size = keylen;
            i = hes_udb_get(&key, &info);
            if (i != 0 || info.size <= 0)
            {
                if (tTd(28, 2))
                    sm_dprintf("udbmatch: no match on %s (%d) via hesiod\n",
                        keybuf, keylen);
                continue;
            }

            p = sm_rpool_malloc_x(rpool, info.size + 1);
            memmove(p, info.data, info.size);
            p[info.size] = '\0';
            if (tTd(28, 1))
                sm_dprintf("udbmatch ==> %s\n", p);
            return p;
# endif /* HESIOD */
        }
    }

    if (strcmp(field, "mailname") != 0)
        return NULL;

    /*
    **  Nothing yet.  Search again for a default case.  But only
    **  use it if we also have a forward (:maildrop) pointer already
    **  in the database.
    */

    /* build database key */
    (void) sm_strlcpyn(keybuf, sizeof(keybuf), 2, user, ":maildrop");
    keylen = strlen(keybuf);

    for (up = UdbEnts; up->udb_type != UDB_EOLIST; up++)
    {
        switch (up->udb_type)
        {
# if NEWDB
          case UDB_DBFETCH:
            /* get the default case for this database */
            if (up->udb_default == NULL)
            {
                memset(&key, '\0', sizeof(key));
                memset(&info, '\0', sizeof(info));
                key.data = ":default:mailname";
                key.size = strlen(key.data);
#  if DB_VERSION_MAJOR < 2
                i = (*up->udb_dbp->get)(up->udb_dbp,
                            &key, &info, 0);
#  else /* DB_VERSION_MAJOR < 2 */
                i = errno = (*up->udb_dbp->get)(up->udb_dbp,
                                NULL, &key,
                                &info, 0);
#  endif /* DB_VERSION_MAJOR < 2 */
                if (i != 0 || info.size <= 0)
                {
                    /* no default case */
                    up->udb_default = "";
                    continue;
                }

                /* save the default case */
                up->udb_default = sm_pmalloc_x(info.size + 1);
                memmove(up->udb_default, info.data, info.size);
                up->udb_default[info.size] = '\0';
            }
            else if (up->udb_default[0] == '\0')
                continue;

            /* we have a default case -- verify user:maildrop */
            memset(&key, '\0', sizeof(key));
            memset(&info, '\0', sizeof(info));
            key.data = keybuf;
            key.size = keylen;
#  if DB_VERSION_MAJOR < 2
            i = (*up->udb_dbp->get)(up->udb_dbp, &key, &info, 0);
#  else /* DB_VERSION_MAJOR < 2 */
            i = errno = (*up->udb_dbp->get)(up->udb_dbp, NULL,
                            &key, &info, 0);
#  endif /* DB_VERSION_MAJOR < 2 */
            if (i != 0 || info.size <= 0)
            {
                /* nope -- no aliasing for this user */
                continue;
            }

            /* they exist -- build the actual address */
            i = strlen(user) + strlen(up->udb_default) + 2;
            p = sm_rpool_malloc_x(rpool, i);
            (void) sm_strlcpyn(p, i, 3, user, "@", up->udb_default);
            if (tTd(28, 1))
                sm_dprintf("udbmatch ==> %s\n", p);
            return p;
# endif /* NEWDB */

# if HESIOD
          case UDB_HESIOD:
            /* get the default case for this database */
            if (up->udb_default == NULL)
            {
                key.data = ":default:mailname";
                key.size = strlen(key.data);
                i = hes_udb_get(&key, &info);

                if (i != 0 || info.size <= 0)
                {
                    /* no default case */
                    up->udb_default = "";
                    continue;
                }

                /* save the default case */
                up->udb_default = sm_pmalloc_x(info.size + 1);
                memmove(up->udb_default, info.data, info.size);
                up->udb_default[info.size] = '\0';
            }
            else if (up->udb_default[0] == '\0')
                continue;

            /* we have a default case -- verify user:maildrop */
            key.data = keybuf;
            key.size = keylen;
            i = hes_udb_get(&key, &info);
            if (i != 0 || info.size <= 0)
            {
                /* nope -- no aliasing for this user */
                continue;
            }

            /* they exist -- build the actual address */
            i = strlen(user) + strlen(up->udb_default) + 2;
            p = sm_rpool_malloc_x(rpool, i);
            (void) sm_strlcpyn(p, i, 3, user, "@", up->udb_default);
            if (tTd(28, 1))
                sm_dprintf("udbmatch ==> %s\n", p);
            return p;
            break;
# endif /* HESIOD */
        }
    }

    /* still nothing....  too bad */
    return NULL;
}
/*
**  UDB_MAP_LOOKUP -- look up arbitrary entry in user database map
**
**  Parameters:
**      map -- the map being queried.
**      name -- the name to look up.
**      av -- arguments to the map lookup.
**      statp -- to get any error status.
**
**  Returns:
**      NULL if name not found in map.
**      The rewritten name otherwise.
*/

/* ARGSUSED3 */
char *
udb_map_lookup(map, name, av, statp)
    MAP *map;
    char *name;
    char **av;
    int *statp;
{
    char *val;
    char *key;
    char *SM_NONVOLATILE result = NULL;
    char keybuf[MAXNAME + 1];

    if (tTd(28, 20) || tTd(38, 20))
        sm_dprintf("udb_map_lookup(%s, %s)\n", map->map_mname, name);

    if (bitset(MF_NOFOLDCASE, map->map_mflags))
    {
        key = name;
    }
    else
    {
        int keysize = strlen(name);

        if (keysize > sizeof(keybuf) - 1)
            keysize = sizeof(keybuf) - 1;
        memmove(keybuf, name, keysize);
        keybuf[keysize] = '\0';
        makelower(keybuf);
        key = keybuf;
    }
    val = udbmatch(key, map->map_file, NULL);
    if (val == NULL)
        return NULL;
    SM_TRY
        if (bitset(MF_MATCHONLY, map->map_mflags))
            result = map_rewrite(map, name, strlen(name), NULL);
        else
            result = map_rewrite(map, val, strlen(val), av);
    SM_FINALLY
        sm_free(val);
    SM_END_TRY
    return result;
}
/*
**  _UDBX_INIT -- parse the UDB specification, opening any valid entries.
**
**  Parameters:
**      e -- the current envelope.
**
**  Returns:
**      EX_TEMPFAIL -- if it appeared it couldn't get hold of a
**          database due to a host being down or some similar
**          (recoverable) situation.
**      EX_OK -- otherwise.
**
**  Side Effects:
**      Fills in the UdbEnts structure from UdbSpec.
*/

# define MAXUDBOPTS 27

static int
_udbx_init(e)
    ENVELOPE *e;
{
    int ents = 0;
    register char *p;
    register struct udbent *up;

    if (UdbInitialized)
        return EX_OK;

# ifdef UDB_DEFAULT_SPEC
    if (UdbSpec == NULL)
        UdbSpec = UDB_DEFAULT_SPEC;
# endif /* UDB_DEFAULT_SPEC */

    p = UdbSpec;
    up = UdbEnts;
    while (p != NULL)
    {
        char *spec;
        int l;
        struct udb_option opts[MAXUDBOPTS + 1];

        while (*p == ' ' || *p == '\t' || *p == ',')
            p++;
        if (*p == '\0')
            break;
        spec = p;
        p = strchr(p, ',');
        if (p != NULL)
            *p++ = '\0';

        if (ents >= MAXUDBENT)
        {
            syserr("Maximum number of UDB entries exceeded");
            break;
        }

        /* extract options */
        (void) _udb_parsespec(spec, opts, MAXUDBOPTS);

        /*
        **  Decode database specification.
        **
        **  In the sendmail tradition, the leading character
        **  defines the semantics of the rest of the entry.
        **
        **  @hostname --    forward email to the indicated host.
        **          This should be the last in the list,
        **          since it always matches the input.
        **  /dbname  -- search the named database on the local
        **          host using the Berkeley db package.
        **  Hesiod --   search the named database with BIND
        **          using the MIT Hesiod package.
        */

        switch (*spec)
        {
          case '@': /* forward to remote host */
            up->udb_type = UDB_FORWARD;
            up->udb_pid = CurrentPid;
            up->udb_fwdhost = spec + 1;
            ents++;
            up++;
            break;

# if HESIOD
          case 'h': /* use hesiod */
          case 'H':
            if (sm_strcasecmp(spec, "hesiod") != 0)
                goto badspec;
            up->udb_type = UDB_HESIOD;
            up->udb_pid = CurrentPid;
            ents++;
            up++;
            break;
# endif /* HESIOD */

# if NEWDB
          case '/': /* look up remote name */
            l = strlen(spec);
            if (l > 3 && strcmp(&spec[l - 3], ".db") == 0)
            {
                up->udb_dbname = spec;
            }
            else
            {
                up->udb_dbname = sm_pmalloc_x(l + 4);
                (void) sm_strlcpyn(up->udb_dbname, l + 4, 2,
                           spec, ".db");
            }
            errno = 0;
#  if DB_VERSION_MAJOR < 2
            up->udb_dbp = dbopen(up->udb_dbname, O_RDONLY,
                         0644, DB_BTREE, NULL);
#  else /* DB_VERSION_MAJOR < 2 */
            {
                int flags = DB_RDONLY;
#  if DB_VERSION_MAJOR > 2
                int ret;
#  endif /* DB_VERSION_MAJOR > 2 */

                SM_DB_FLAG_ADD(flags);
                up->udb_dbp = NULL;
#  if DB_VERSION_MAJOR > 2
                ret = db_create(&up->udb_dbp, NULL, 0);
                if (ret != 0)
                {
                    (void) up->udb_dbp->close(up->udb_dbp,
                                  0);
                    up->udb_dbp = NULL;
                }
                else
                {
                    ret = up->udb_dbp->open(up->udb_dbp,
                                DBTXN
                                up->udb_dbname,
                                NULL,
                                DB_BTREE,
                                flags,
                                0644);
                    if (ret != 0)
                    {
#ifdef DB_OLD_VERSION
                        if (ret == DB_OLD_VERSION)
                            ret = EINVAL;
#endif /* DB_OLD_VERSION */
                        (void) up->udb_dbp->close(up->udb_dbp, 0);
                        up->udb_dbp = NULL;
                    }
                }
                errno = ret;
#  else /* DB_VERSION_MAJOR > 2 */
                errno = db_open(up->udb_dbname, DB_BTREE,
                        flags, 0644, NULL,
                        NULL, &up->udb_dbp);
#  endif /* DB_VERSION_MAJOR > 2 */
            }
#  endif /* DB_VERSION_MAJOR < 2 */
            if (up->udb_dbp == NULL)
            {
                if (tTd(28, 1))
                {
                    int save_errno = errno;

#  if DB_VERSION_MAJOR < 2
                    sm_dprintf("dbopen(%s): %s\n",
#  else /* DB_VERSION_MAJOR < 2 */
                    sm_dprintf("db_open(%s): %s\n",
#  endif /* DB_VERSION_MAJOR < 2 */
                        up->udb_dbname,
                        sm_errstring(errno));
                    errno = save_errno;
                }
                if (errno != ENOENT && errno != EACCES)
                {
                    if (LogLevel > 2)
                        sm_syslog(LOG_ERR, e->e_id,
#  if DB_VERSION_MAJOR < 2
                              "dbopen(%s): %s",
#  else /* DB_VERSION_MAJOR < 2 */
                              "db_open(%s): %s",
#  endif /* DB_VERSION_MAJOR < 2 */
                              up->udb_dbname,
                              sm_errstring(errno));
                    up->udb_type = UDB_EOLIST;
                    if (up->udb_dbname != spec)
                        sm_free(up->udb_dbname); /* XXX */
                    goto tempfail;
                }
                if (up->udb_dbname != spec)
                    sm_free(up->udb_dbname); /* XXX */
                break;
            }
            if (tTd(28, 1))
            {
#  if DB_VERSION_MAJOR < 2
                sm_dprintf("_udbx_init: dbopen(%s)\n",
#  else /* DB_VERSION_MAJOR < 2 */
                sm_dprintf("_udbx_init: db_open(%s)\n",
#  endif /* DB_VERSION_MAJOR < 2 */
                    up->udb_dbname);
            }
            up->udb_type = UDB_DBFETCH;
            up->udb_pid = CurrentPid;
            ents++;
            up++;
            break;
# endif /* NEWDB */

          default:
# if HESIOD
badspec:
# endif /* HESIOD */
            syserr("Unknown UDB spec %s", spec);
            break;
        }
    }
    up->udb_type = UDB_EOLIST;

    if (tTd(28, 4))
    {
        for (up = UdbEnts; up->udb_type != UDB_EOLIST; up++)
        {
            switch (up->udb_type)
            {
              case UDB_REMOTE:
                sm_dprintf("REMOTE: addr %s, timeo %d\n",
                       anynet_ntoa((SOCKADDR *) &up->udb_addr),
                       up->udb_timeout);
                break;

              case UDB_DBFETCH:
# if NEWDB
                sm_dprintf("FETCH: file %s\n",
                    up->udb_dbname);
# else /* NEWDB */
                sm_dprintf("FETCH\n");
# endif /* NEWDB */
                break;

              case UDB_FORWARD:
                sm_dprintf("FORWARD: host %s\n",
                    up->udb_fwdhost);
                break;

              case UDB_HESIOD:
                sm_dprintf("HESIOD\n");
                break;

              default:
                sm_dprintf("UNKNOWN\n");
                break;
            }
        }
    }

    UdbInitialized = true;
    errno = 0;
    return EX_OK;

    /*
    **  On temporary failure, back out anything we've already done
    */

  tempfail:
# if NEWDB
    for (up = UdbEnts; up->udb_type != UDB_EOLIST; up++)
    {
        if (up->udb_type == UDB_DBFETCH)
        {
#  if DB_VERSION_MAJOR < 2
            (*up->udb_dbp->close)(up->udb_dbp);
#  else /* DB_VERSION_MAJOR < 2 */
            errno = (*up->udb_dbp->close)(up->udb_dbp, 0);
#  endif /* DB_VERSION_MAJOR < 2 */
            if (tTd(28, 1))
                sm_dprintf("_udbx_init: db->close(%s)\n",
                    up->udb_dbname);
        }
    }
# endif /* NEWDB */
    return EX_TEMPFAIL;
}

static int
_udb_parsespec(udbspec, opt, maxopts)
    char *udbspec;
    struct udb_option opt[];
    int maxopts;
{
    register char *spec;
    register char *spec_end;
    register int optnum;

    spec_end = strchr(udbspec, ':');
    for (optnum = 0; optnum < maxopts && (spec = spec_end) != NULL; optnum++)
    {
        register char *p;

        while (isascii(*spec) && isspace(*spec))
            spec++;
        spec_end = strchr(spec, ':');
        if (spec_end != NULL)
            *spec_end++ = '\0';

        opt[optnum].udbo_name = spec;
        opt[optnum].udbo_val = NULL;
        p = strchr(spec, '=');
        if (p != NULL)
            opt[optnum].udbo_val = ++p;
    }
    return optnum;
}
/*
**  _UDBX_CLOSE -- close all file based UDB entries.
**
**  Parameters:
**      none
**
**  Returns:
**      none
*/
void
_udbx_close()
{
    struct udbent *up;

    if (!UdbInitialized)
        return;

    for (up = UdbEnts; up->udb_type != UDB_EOLIST; up++)
    {
        if (up->udb_pid != CurrentPid)
            continue;

# if NEWDB
        if (up->udb_type == UDB_DBFETCH)
        {
#  if DB_VERSION_MAJOR < 2
            (*up->udb_dbp->close)(up->udb_dbp);
#  else /* DB_VERSION_MAJOR < 2 */
            errno = (*up->udb_dbp->close)(up->udb_dbp, 0);
#  endif /* DB_VERSION_MAJOR < 2 */
        }
        if (tTd(28, 1))
            sm_dprintf("_udbx_init: db->close(%s)\n",
                up->udb_dbname);
# endif /* NEWDB */
    }
}

# if HESIOD

static int
hes_udb_get(key, info)
    DBT *key;
    DBT *info;
{
    char *name, *type;
    char **hp;
    char kbuf[MAXUDBKEY + 1];

    if (sm_strlcpy(kbuf, key->data, sizeof(kbuf)) >= sizeof(kbuf))
        return 0;
    name = kbuf;
    type = strrchr(name, ':');
    if (type == NULL)
        return 1;
    *type++ = '\0';
    if (strchr(name, '@') != NULL)
        return 1;

    if (tTd(28, 1))
        sm_dprintf("hes_udb_get(%s, %s)\n", name, type);

    /* make the hesiod query */
#  ifdef HESIOD_INIT
    if (HesiodContext == NULL && hesiod_init(&HesiodContext) != 0)
        return -1;
    hp = hesiod_resolve(HesiodContext, name, type);
#  else /* HESIOD_INIT */
    hp = hes_resolve(name, type);
#  endif /* HESIOD_INIT */
    *--type = ':';
#  ifdef HESIOD_INIT
    if (hp == NULL)
        return 1;
    if (*hp == NULL)
    {
        hesiod_free_list(HesiodContext, hp);
        if (errno == ECONNREFUSED || errno == EMSGSIZE)
            return -1;
        return 1;
    }
#  else /* HESIOD_INIT */
    if (hp == NULL || hp[0] == NULL)
    {
        /* network problem or timeout */
        if (hes_error() == HES_ER_NET)
            return -1;

        return 1;
    }
#  endif /* HESIOD_INIT */
    else
    {
        /*
        **  If there are multiple matches, just return the
        **  first one.
        **
        **  XXX These should really be returned; for example,
        **  XXX it is legal for :maildrop to be multi-valued.
        */

        info->data = hp[0];
        info->size = (size_t) strlen(info->data);
    }

    if (tTd(28, 80))
        sm_dprintf("hes_udb_get => %s\n", *hp);

    return 0;
}
# endif /* HESIOD */

#else /* USERDB */

int
udbexpand(a, sendq, aliaslevel, e)
    ADDRESS *a;
    ADDRESS **sendq;
    int aliaslevel;
    ENVELOPE *e;
{
    return EX_OK;
}

#endif /* USERDB */