/*      $NetBSD: mtab.c,v 1.1.1.3 2015/01/17 16:34:18 christos Exp $    */

/*
* Copyright (c) 1997-2014 Erez Zadok
* Copyright (c) 1989 Jan-Simon Pendry
* Copyright (c) 1989 Imperial College of Science, Technology & Medicine
* Copyright (c) 1989 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.
*
*
* File: am-utils/libamu/mtab.c
*
*/

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif /* HAVE_CONFIG_H */
#include <am_defs.h>
#include <amu.h>


/*
* Firewall /etc/mtab entries
*/
void
mnt_free(mntent_t *mp)
{
 XFREE(mp->mnt_fsname);
 XFREE(mp->mnt_dir);
 XFREE(mp->mnt_type);
 XFREE(mp->mnt_opts);

#ifdef HAVE_MNTENT_T_MNT_TIME
# ifdef HAVE_MNTENT_T_MNT_TIME_STRING
 XFREE(mp->mnt_time);
# endif /* HAVE_MNTENT_T_MNT_TIME_STRING */
#endif /* HAVE_MNTENT_T_MNT_TIME */

 XFREE(mp);
}


/*
* Discard memory allocated for mount list
*/
void
discard_mntlist(mntlist *mp)
{
 mntlist *mp2;

 while ((mp2 = mp)) {
   mp = mp->mnext;
   if (mp2->mnt)
     mnt_free(mp2->mnt);
   XFREE(mp2);
 }
}


/*
* Throw away a mount list
*/
void
free_mntlist(mntlist *mp)
{
 discard_mntlist(mp);
#ifdef MOUNT_TABLE_ON_FILE
 unlock_mntlist();
#endif /* MOUNT_TABLE_ON_FILE */
}


/*
* Utility routine which returns a pointer to whatever follows an = in a
* string.  Returns null if = is not found in the string.
*/
char *
haseq(char *instr)
{
 if (instr) {
   char *eq = strchr(instr, '=');
   if (eq) return ++eq;
 }
 return NULL;
}


/*
* Utility routine which returns a pointer to whatever
* follows an = in a mount option.  Returns null if option
* doesn't exist or doesn't have an '='.  Won't fail for opt,foo=.
*/
char *
hasmnteq(mntent_t *mnt, char *opt)
{
 if (mnt && opt) {             /* disallow null input pointers */
   if ( *opt ) {               /* disallow the null string as an opt */
     char *str = amu_hasmntopt(mnt, opt);
     if ( str ) {              /* option was there */
       char *eq = str + strlen(opt); /* Look at char just after option */
       if (*eq == '=')         /* Is it '=' ? */
         return ++eq;          /* If so, return pointer to remaining str */
     }
   }
 }
 return NULL;
}


/*
* Wrapper around hasmntvalerr(), which retains backwards compatibiliy with
* older use of hasmntval().
*
* XXX: eventually, all use of hasmntval() should be replaced with
* hasmntvalerr().
*/
int
hasmntval(mntent_t *mnt, char *opt)
{
 int err, val = 0;

 err = hasmntvalerr(mnt, opt, &val);
 if (err)         /* if there was an error (hasmntvalerr returned 1) */
   return 0;      /* redundant: val==0 above, but leave here for clarity */
 /* otherwise there was no error */
 return val;
}


/*
* Utility routine which determines the value of a numeric option in the
* mount options (such as port=%d), and fills in the value in the argument
* valp (argument won't be touched if no value is set, for example due to an
* error).
*
* Returns non-zero (1) on error; returns 0 on success.
*
* XXX: eventually, all use of hasmntval() should be replaced with
* hasmntvalerr().
*/
unsigned int
hasmntvalerr(mntent_t *mnt, char *opt, int *valp)
{
 char *str = amu_hasmntopt(mnt, opt);
 int err = 1;               /* 1 means no good value was set (an error) */
 char *eq, *endptr;
 long int i;

 /* exit if no option specificed */
 if (!str) {
   goto out;
 }

 eq = hasmnteq(mnt, opt);

 if (!eq) {              /* no argument to option ('=' sign was missing) */
   plog(XLOG_MAP, "numeric option to \"%s\" missing", opt);
   goto out;
 }

 /* if got here, then we had an '=' after option name */
 endptr = NULL;
 i = strtol(eq, &endptr, 0); /* hex and octal allowed ;-) */
 if (!endptr ||
     (endptr != eq && (*endptr == ',' || *endptr == '\0'))) {
     /*
      * endptr set means strtol saw a non-digit.  If the non-digit is a
      * comma, it's probably the start of the next option.  If the comma is
      * the first char though, complain about it (foo=,bar is made
      * noticeable by this).
      *
      * Similar reasoning for '\0' instead of comma, it's the end of the
      * string.
      */
   *valp = (int) i;            /* set good value */
   err = 0;                    /* no error */
 } else {
   /* whatever was after the '=' sign wasn't a number */
   plog(XLOG_MAP, "invalid numeric option in \"%s\": \"%s\"", opt, str);
   /* fall through to error/exit processing */
 }

out:
 return err;
}


/*
* Utility routine which returns the string value of
* an option in the mount options (such as proto=udp).
* Returns NULL if the option is not specified.
* Returns malloc'ed string (caller must free!)
*/
char *
hasmntstr(mntent_t *mnt, char *opt)
{
 char *str = amu_hasmntopt(mnt, opt);

 if (str) { /* The option was there */

   char *eq = hasmnteq(mnt, opt);

   if (eq) { /* and had an = after it */

     char *endptr = strchr(eq, ',');

     /* if saw no comma, return xstrdup'd string */
     if (!endptr)
       return xstrdup(eq);
     else {
       /* else we need to copy only the chars needed */
       int len = endptr - eq;
       char *buf = xmalloc(len + 1);
       strncpy(buf, eq, len);
       buf[len] = '\0';
       return buf;
     }
   }
 }
 return NULL;
}