/*
 * Copyright (c) 1990 Jan-Simon Pendry
 * Copyright (c) 1990 Imperial College of Science, Technology & Medicine
 * Copyright (c) 1990, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Jan-Simon Pendry at Imperial College, London.
 *
 * 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. 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.
 *
 *      from: @(#)info_passwd.c 8.1 (Berkeley) 6/6/93
 *      $Id: info_passwd.c,v 1.11 2021/10/21 10:55:56 deraadt Exp $
 */

/*
 * Get info from password "file"
 *
 * This is experimental and probably doesn't
 * do what you expect.
 */

#include "am.h"

#include <pwd.h>

#define PASSWD_MAP      "/etc/passwd"

/*
 * Nothing to probe - check the map name is PASSWD_MAP.
 */
int
passwd_init(char *map, time_t *tp)
{
        *tp = 0;
        return strcmp(map, PASSWD_MAP) == 0 ? 0 : ENOENT;
}


/*
 * Grab the entry via the getpwname routine
 * Modify time is ignored by passwd - XXX
 */
int
passwd_search(mnt_map *m, char *map, char *key, char **pval, time_t *tp)
{
        struct passwd *pw;
        char *dir = 0;

        if (strcmp(key, "/defaults") == 0) {
                *pval = strdup("type:=nfs");
                return 0;
        }

        pw = getpwnam(key);
        if (pw) {
                /*
                 * We chop the home directory up as follows:
                 * /anydir/dom1/dom2/dom3/user
                 *
                 * and return
                 * rfs:=/anydir/dom3;rhost:=dom3.dom2.dom1;sublink:=user
                 *
                 * This allows cross-domain entries in your passwd file.
                 * ... but forget about security!
                 */
                char val[PATH_MAX], rhost[HOST_NAME_MAX+1];
                char *user, *p, *q;

                dir = strdup(pw->pw_dir);
                /*
                 * Find user name.  If no / then Invalid...
                 */
                user = strrchr(dir, '/');
                if (!user)
                        goto enoent;
                *user++ = '\0';
                /*
                 * Find start of host "path".  If no / then Invalid...
                 */
                p = strchr(dir+1, '/');
                if (!p)
                        goto enoent;
                *p++ = '\0';
                /*
                 * At this point, p is dom1/dom2/dom3
                 * Copy, backwards, into rhost replacing
                 * / with .
                 */
                rhost[0] = '\0';
                do {
                        q = strrchr(p, '/');
                        if (q) {
                                strlcat(rhost, q + 1, sizeof(rhost));
                                strlcat(rhost, ".", sizeof(rhost));
                                *q = '\0';
                        } else {
                                strlcat(rhost, p, sizeof(rhost));
                        }
                } while (q);

                /*
                 * Sanity check
                 */
                if (*rhost == '\0' || *user == '\0' || *dir == '\0')
                        goto enoent;
                /*
                 * Make up return string
                 */
                q = strchr(rhost, '.');
                if (q)
                        *q = '\0';
                snprintf(val, sizeof(val),
                    "rfs:=%s/%s;rhost:=%s;sublink:=%s;fs:=${autodir}%s",
                    dir, rhost, rhost, user, pw->pw_dir);
                free(dir);
                if (q)
                        *q = '.';
                *pval = strdup(val);
                return 0;
        }

enoent:
        free(dir);

        return ENOENT;
}