/*
 * 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_union.c  8.1 (Berkeley) 6/6/93
 *      $Id: info_union.c,v 1.9 2014/10/26 03:03:34 guenther Exp $
 */

/*
 * Get info from the system namespace
 *
 * NOTE: Cannot handle reads back through the automounter.
 * THIS WILL CAUSE A DEADLOCK!
 */

#include "am.h"


#include <dirent.h>
#define DIRENT struct dirent

#define UNION_PREFIX    "union:"
#define UNION_PREFLEN   6

/*
 * No way to probe - check the map name begins with "union:"
 */
int
union_init(char *map, time_t *tp)
{
        *tp = 0;
        return strncmp(map, UNION_PREFIX, UNION_PREFLEN) == 0 ? 0 : ENOENT;
}

int
union_search(mnt_map *m, char *map, char *key, char **pval, time_t *tp)
{
        char *mapd = strdup(map + UNION_PREFLEN);
        char **v = strsplit(mapd, ':', '\"');
        char **p;

        for (p = v; p[1]; p++)
                ;
        *pval = xmalloc(strlen(*p) + 5);
        snprintf(*pval, strlen(*p) + 5, "fs:=%s", *p);
        free(mapd);
        free(v);
        return 0;
}

int
union_reload(mnt_map *m, char *map, void (*fn)(mnt_map *, char *, char *))
{
        char *mapd = strdup(map + UNION_PREFLEN);
        char **v = strsplit(mapd, ':', '\"');
        char **dir;

        /*
         * Add fake /defaults entry
         */
        (*fn)(m, strdup("/defaults"),
            strdup("type:=link;opts:=nounmount;sublink:=${key}"));

        for (dir = v; *dir; dir++) {
                DIR *dirp = opendir(*dir);
                DIRENT *dp;
                int dlen;

                if (!dirp) {
                        plog(XLOG_USER, "Cannot read directory %s: %m", *dir);
                        continue;
                }
                dlen = strlen(*dir);
#ifdef DEBUG
                dlog("Reading directory %s...", *dir);
#endif
                while ((dp = readdir(dirp))) {
                        char *val;

                        if (dp->d_name[0] == '.' &&
                            (dp->d_name[1] == '\0' ||
                            (dp->d_name[1] == '.' && dp->d_name[2] == '\0')))
                                continue;

#ifdef DEBUG
                        dlog("... gives %s", dp->d_name);
#endif
                        val = xmalloc(dlen + 5);
                        snprintf(val, dlen + 5, "fs:=%s", *dir);
                        (*fn)(m, strdup(dp->d_name), val);
                }
                closedir(dirp);
        }

        /*
         * Add wildcard entry
         */
        {
                char *val = xmalloc(strlen(dir[-1]) + 5);

                snprintf(val, strlen(dir[-1]) + 5, "fs:=%s", dir[-1]);
                (*fn)(m, strdup("*"), val);
        }
        free(mapd);
        free(v);
        return 0;
}