library/stat_lock.c
/*
* $Id: stat_lock.c,v 1.1 2006-11-13 09:25:28 obarthel Exp $
*
* :ts=4
*
* Portable ISO 'C' (1994) runtime library for the Amiga computer
* Copyright (c) 2002-2015 by Olaf Barthel <obarthel (at) gmx.net>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* - Neither the name of Olaf Barthel nor the names of contributors
* may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT OWNER 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.
*/
#ifndef _STDLIB_NULL_POINTER_CHECK_H
#include "stdlib_null_pointer_check.h"
#endif /* _STDLIB_NULL_POINTER_CHECK_H */
/****************************************************************************/
#ifndef _STAT_HEADERS_H
#include "stat_headers.h"
#endif /* _STAT_HEADERS_H */
#ifndef _LOCALE_HEADERS_H
#include "locale_headers.h"
#endif /* _LOCALE_HEADERS_H */
#ifndef _TIME_HEADERS_H
#include "time_headers.h"
#endif /* _TIME_HEADERS_H */
/****************************************************************************/
/* The following is not part of the ISO 'C' (1994) standard. */
/****************************************************************************/
/*
* __lock(): An implementation of Lock() which remembers whether or
* not it resolved soft links.
*
* Unfortunately is is limited to 255 character names.
*/
BPTR
__lock(
const char * name,
const int mode,
int * link_length,
char * real_name,
size_t real_name_size)
{
D_S(struct bcpl_name,bname);
const size_t name_size = sizeof(bname->name);
char * new_name = NULL;
struct DevProc * dvp = NULL;
BPTR lock = ZERO;
size_t name_len;
LONG error;
assert( name != NULL && link_length != NULL );
if(real_name != NULL && real_name_size > 0)
strcpy(real_name,"");
name_len = strlen(name);
if(name_len >= name_size)
{
SetIoErr(ERROR_LINE_TOO_LONG);
goto out;
}
/* Convert the name into a BCPL string. */
bname->name[0] = name_len;
memmove(&bname->name[1],name,name_len);
while(TRUE)
{
/* Get a handle on the device, volume or assignment name in the path. */
dvp = GetDeviceProc((STRPTR)name,dvp);
if(dvp == NULL)
goto out;
/* Try to obtain a lock on the object. */
lock = DoPkt(dvp->dvp_Port,ACTION_LOCATE_OBJECT,dvp->dvp_Lock,MKBADDR(bname),mode,0,0);
if(lock != ZERO)
break;
error = IoErr();
if(error == ERROR_OBJECT_NOT_FOUND)
{
/* If this is part of a multi-volume assignment, try the next part. */
if(FLAG_IS_SET(dvp->dvp_Flags,DVPF_ASSIGN))
continue;
/* Not much we can do here... */
break;
}
else if (error == ERROR_IS_SOFT_LINK)
{
size_t new_name_size = name_size+1;
LONG result;
/* Provide as much buffer space as possible. */
if(real_name_size > new_name_size)
new_name_size = real_name_size;
/* For soft link resolution we need a temporary buffer to
let the file system store the resolved path name in. */
new_name = malloc(new_name_size);
if(new_name == NULL)
{
SetIoErr(ERROR_NO_FREE_STORE);
goto out;
}
/* Now ask the file system to resolve the entire path. */
result = ReadLink(dvp->dvp_Port,dvp->dvp_Lock,(STRPTR)name,(STRPTR)new_name,(LONG)new_name_size);
if(result < 0)
{
/* This will return either -1 (resolution error) or -2
(buffer too small). We regard both as trouble. */
SetIoErr(ERROR_INVALID_COMPONENT_NAME);
goto out;
}
assert( result > 0 );
/* Remember the length of the link name. */
(*link_length) = result;
/* If the caller supplied a buffer, copy as much of the name
as possible into it. */
if(real_name != NULL && real_name_size > 0)
strlcpy(real_name,new_name,real_name_size);
/* Finished for now. */
break;
}
else
{
/* Some other error; ask if the user wants to have another go at it. */
if(ErrorReport(error,REPORT_LOCK,dvp->dvp_Lock,dvp->dvp_Port) != 0)
break;
}
/* Retry the lookup. */
FreeDeviceProc(dvp);
dvp = NULL;
}
out:
error = IoErr();
if(new_name != NULL)
free(new_name);
if(dvp != NULL)
FreeDeviceProc(dvp);
SetIoErr(error);
return(lock);
}