/*      $NetBSD: getdiskrawname.c,v 1.2 2013/12/22 14:31:51 mlelstv Exp $       */

/*-
* Copyright (c) 2012 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Christos Zoulas.
*
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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 <sys/cdefs.h>
__RCSID("$NetBSD: getdiskrawname.c,v 1.2 2013/12/22 14:31:51 mlelstv Exp $");

#include <sys/stat.h>

#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <util.h>
#include <limits.h>
#include <unistd.h>

static const char *
resolve_link(char *buf, size_t bufsiz, const char *name)
{
       const char *dp;
       ssize_t nlen, dlen;

       dlen = readlink(name, buf, bufsiz-1);
       if (dlen == -1)
               return name;

       buf[dlen] = '\0';

       if (buf[0] != '/') {
               dp = strrchr(name, '/');
               if (dp != NULL) {
                       nlen = dp - name + 1;
                       if (nlen + 1 > PATH_MAX)
                               return NULL;
                       if (nlen + dlen + 1 > PATH_MAX)
                               return NULL;

                       memmove(buf+nlen, buf, dlen+1);
                       memcpy(buf, name, nlen);
               }
       }

       return buf;
}

const char *
getdiskrawname(char *buf, size_t bufsiz, const char *name)
{
       const char *dp;
       struct stat st;
       char dest[PATH_MAX];

       if ((name = resolve_link(dest, sizeof(dest), name)) == NULL) {
               errno = EINVAL;
               return NULL;
       }

       dp = strrchr(name, '/');

       if (stat(name, &st) == -1)
               return NULL;

       if (!S_ISBLK(st.st_mode)) {
               errno = EFTYPE;
               return NULL;
       }

       if (dp != NULL)
               (void)snprintf(buf, bufsiz, "%.*s/r%s", (int)(dp - name), name, dp + 1);
       else
               (void)snprintf(buf, bufsiz, "r%s", name);

       return buf;
}

const char *
getdiskcookedname(char *buf, size_t bufsiz, const char *name)
{
       const char *dp;
       struct stat st;
       char dest[PATH_MAX];

       if ((name = resolve_link(dest, sizeof(dest), name)) == NULL) {
               errno = EINVAL;
               return NULL;
       }

       dp = strrchr(name, '/');

       if ((dp != NULL && dp[1] != 'r') || (dp == NULL && name[0] != 'r')) {
               errno = EINVAL;
               return NULL;
       }

       if (stat(name, &st) == -1)
               return NULL;

       if (!S_ISCHR(st.st_mode)) {
               errno = EFTYPE;
               return NULL;
       }

       if (dp != NULL)
               (void)snprintf(buf, bufsiz, "%.*s/%s", (int)(dp - name), name, dp + 2);
       else
               (void)snprintf(buf, bufsiz, "%s", name + 1);

       return buf;
}