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/*
* XXX
*
* COPYRIGHT (c) 1989-1998.
* On-Line Applications Research Corporation (OAR).
* Copyright assigned to U.S. Government, 1994.
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.OARcorp.com/rtems/license.html.
*
* $Id$
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <chain.h>
#include <fcntl.h>
#include <errno.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <assert.h>
#include <dirent.h>
#include "imfs.h"
#include "libio_.h"
long getdents(
int dd_fd,
char *dd_buf,
int dd_len
);
/* -----------------------------------------------------------------------
* This rountine will verify that the node being opened as a directory is
* in fact a directory node. If it is then the offset into the directory
* will be set to 0 to position to the first directory entry.
*/
int imfs_dir_open(
rtems_libio_t *iop,
const char *pathname,
unsigned32 flag,
unsigned32 mode
)
{
IMFS_jnode_t *the_jnode;
/* Is the node a directory ? */
the_jnode = (IMFS_jnode_t *) iop->file_info;
if ( the_jnode->type != IMFS_DIRECTORY )
return -1; /* It wasn't a directory --> return error */
iop->offset = 0;
return 0;
}
/* -----------------------------------------------------------------------
* This routine will read the next directory entry based on the directory
* offset. The offset should be equal to -n- time the size of an individual
* dirent structure. If n is not an integer multiple of the sizeof a
* dirent structure, an integer division will be performed to determine
* directory entry that will be returned in the buffer. Count should reflect
* -m- times the sizeof dirent bytes to be placed in the buffer.
* If there are not -m- dirent elements from the current directory position
* to the end of the exisiting file, the remaining entries will be placed in
* the buffer and the returned value will be equal to -m actual- times the
* size of a directory entry.
*/
int imfs_dir_read(
rtems_libio_t *iop,
void *buffer,
unsigned32 count
)
{
/*
* Read up to element iop->offset in the directory chain of the
* imfs_jnode_t struct for this file descriptor.
*/
Chain_Node *the_node;
Chain_Control *the_chain;
IMFS_jnode_t *the_jnode;
int bytes_transferred;
int current_entry;
int first_entry;
int last_entry;
struct dirent tmp_dirent;
the_jnode = (IMFS_jnode_t *)iop->file_info;
the_chain = &the_jnode->info.directory.Entries;
if ( Chain_Is_empty( the_chain ) )
return 0;
/* Move to the first of the desired directory entries */
the_node = the_chain->first;
bytes_transferred = 0;
first_entry = iop->offset;
/* protect against using sizes that are not exact multiples of the */
/* -dirent- size. These could result in unexpected results */
last_entry = first_entry + (count/sizeof(struct dirent)) * sizeof(struct dirent);
/* The directory was not empty so try to move to the desired entry in chain*/
for(
current_entry = 0;
current_entry < last_entry;
current_entry = current_entry + sizeof(struct dirent) ){
if ( Chain_Is_tail( the_chain, the_node ) ){
/* We hit the tail of the chain while trying to move to the first */
/* entry in the read */
return bytes_transferred; /* Indicate that there are no more */
/* entries to return */
}
if( current_entry >= first_entry ) {
/* Move the entry to the return buffer */
tmp_dirent.d_ino = 1;
tmp_dirent.d_off = current_entry;
tmp_dirent.d_reclen = sizeof( struct dirent );
the_jnode = (IMFS_jnode_t *) the_node;
tmp_dirent.d_namlen = strlen( the_jnode->name );
sprintf( tmp_dirent.d_name, "%s", the_jnode->name );
memcpy(
buffer + bytes_transferred,
(void *)&tmp_dirent,
sizeof( struct dirent )
);
iop->offset = iop->offset + sizeof(struct dirent);
bytes_transferred = bytes_transferred + sizeof( struct dirent );
}
the_node = the_node->next;
}
/* Success */
return bytes_transferred;
}
/* -----------------------------------------------------------------------
* This routine will be called by the generic close routine to cleanup any
* resources that have been allocated for the management of the file
*/
int imfs_dir_close(
rtems_libio_t *iop
)
{
/* The generic close routine handles the deallocation of the file control */
/* and associated memory. At present the imfs_dir_close simply */
/* returns a successful completion status */
return 0;
}
/* -----------------------------------------------------------------------
* This routine will behave in one of three ways based on the state of
* argument whence. Based on the state of its value the offset argument will
* be interpreted using one of the following methods:
*
* SEEK_SET - offset is the absolute byte offset from the start of the
* logical start of the dirent sequence that represents the
* directory
* SEEK_CUR - offset is used as the relative byte offset from the current
* directory position index held in the iop structure
* SEEK_END - N/A --> This will cause an assert.
*/
int imfs_dir_lseek(
rtems_libio_t *iop,
off_t offset,
int whence
)
{
off_t normal_offset;
normal_offset = (offset/sizeof(struct dirent)) * sizeof(struct dirent);
switch( whence )
{
case SEEK_SET: /* absolute move from the start of the file */
iop->offset = normal_offset;
break;
case SEEK_CUR: /* relative move */
iop->offset = iop->offset + normal_offset;
break;
case SEEK_END: /* Movement past the end of the directory via lseek */
/* is not a permitted operation */
default:
set_errno_and_return_minus_one( EINVAL );
break;
}
return 0;
}
/* -----------------------------------------------------------------------
* This routine will obtain the following information concerning the current
* directory:
* st_dev 0ll
* st_ino 1
* st_mode mode extracted from the jnode
* st_nlink number of links to this node
* st_uid uid extracted from the jnode
* st_gid gid extracted from the jnode
* st_rdev 0ll
* st_size the number of bytes in the directory
* This is calculated by taking the number of entries
* in the directory and multiplying by the size of a
* dirent structure
* st_blksize 0
* st_blocks 0
* st_atime time of last access
* st_mtime time of last modification
* st_ctime time of the last change
*
* This information will be returned to the calling function in a -stat- struct
*
*/
int imfs_dir_fstat(
rtems_filesystem_location_info_t *loc,
struct stat *buf
)
{
Chain_Node *the_node;
Chain_Control *the_chain;
IMFS_jnode_t *the_jnode;
the_jnode = (IMFS_jnode_t *) loc->node_access;
buf->st_dev = 0ll;
buf->st_ino = the_jnode->st_ino;
buf->st_mode = the_jnode->st_mode;
buf->st_nlink = the_jnode->st_nlink;
buf->st_uid = the_jnode->st_uid;
buf->st_gid = the_jnode->st_gid;
buf->st_rdev = 0ll;
buf->st_blksize = 0;
buf->st_blocks = 0;
buf->st_atime = the_jnode->st_atime;
buf->st_mtime = the_jnode->st_mtime;
buf->st_ctime = the_jnode->st_ctime;
buf->st_size = 0;
the_chain = &the_jnode->info.directory.Entries;
/* Run through the chain and count the number of directory entries */
/* that are subordinate to this directory node */
for ( the_node = the_chain->first ;
!_Chain_Is_tail( the_chain, the_node ) ;
the_node = the_node->next ) {
buf->st_size = buf->st_size + sizeof( struct dirent );
}
return 0;
}
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