diff options
Diffstat (limited to 'cpukit/libfs/src/imfs/imfs_eval.c')
| -rw-r--r-- | cpukit/libfs/src/imfs/imfs_eval.c | 731 |
1 files changed, 118 insertions, 613 deletions
diff --git a/cpukit/libfs/src/imfs/imfs_eval.c b/cpukit/libfs/src/imfs/imfs_eval.c index 78fafca536..43f2ee40e0 100644 --- a/cpukit/libfs/src/imfs/imfs_eval.c +++ b/cpukit/libfs/src/imfs/imfs_eval.c @@ -4,684 +4,189 @@ * COPYRIGHT (c) 1989-1999. * On-Line Applications Research Corporation (OAR). * + * Modifications to support reference counting in the file system are + * Copyright (c) 2012 embedded brains GmbH. + * * The license and distribution terms for this file may be * found in the file LICENSE in this distribution or at * http://www.rtems.com/license/LICENSE. - * - * $Id$ */ #if HAVE_CONFIG_H -#include "config.h" + #include "config.h" #endif -#include <sys/types.h> -#include <sys/stat.h> -#include <fcntl.h> -#include <unistd.h> -#include <errno.h> -#include <stdlib.h> - #include "imfs.h" -#include <rtems/libio_.h> -#include <rtems/seterr.h> -#define RTEMS_LIBIO_PERMS_RX (RTEMS_LIBIO_PERMS_SEARCH | RTEMS_LIBIO_PERMS_READ) -#define RTEMS_LIBIO_PERMS_WX (RTEMS_LIBIO_PERMS_SEARCH | RTEMS_LIBIO_PERMS_WRITE) - -#define MAXSYMLINK 5 - -int IMFS_Set_handlers( - rtems_filesystem_location_info_t *loc -) +void IMFS_Set_handlers( rtems_filesystem_location_info_t *loc ) { - IMFS_jnode_t *node = loc->node_access; - IMFS_fs_info_t *fs_info; + IMFS_jnode_t *node = loc->node_access; + IMFS_fs_info_t *fs_info = loc->mt_entry->fs_info; + const rtems_filesystem_file_handlers_r *handlers; - fs_info = loc->mt_entry->fs_info; - switch( node->type ) { + switch ( node->type ) { case IMFS_DIRECTORY: - loc->handlers = fs_info->directory_handlers; + handlers = &IMFS_directory_handlers; break; case IMFS_DEVICE: - loc->handlers = &IMFS_device_handlers; + handlers = &IMFS_device_handlers; break; - case IMFS_SYM_LINK: case IMFS_HARD_LINK: - loc->handlers = &IMFS_link_handlers; - break; - case IMFS_LINEAR_FILE: - loc->handlers = fs_info->memfile_handlers; + case IMFS_SYM_LINK: + handlers = fs_info->link_handlers; break; case IMFS_MEMORY_FILE: - loc->handlers = fs_info->memfile_handlers; + case IMFS_LINEAR_FILE: + handlers = &IMFS_memfile_handlers; break; case IMFS_FIFO: - loc->handlers = fs_info->fifo_handlers; + handlers = fs_info->fifo_handlers; + break; + default: + IMFS_assert( 0 ); break; } - return 0; -} - -/* - * IMFS_evaluate_permission - * - * The following routine evaluates that we have permission - * to do flags on the node. - */ -static int IMFS_evaluate_permission( - rtems_filesystem_location_info_t *node, - int flags -) -{ - uid_t st_uid; - gid_t st_gid; - IMFS_jnode_t *jnode; - int flags_to_test; - - if ( !rtems_libio_is_valid_perms( flags ) ) - rtems_set_errno_and_return_minus_one( EPERM ); - - jnode = node->node_access; - -#if defined(RTEMS_POSIX_API) - st_uid = geteuid(); - st_gid = getegid(); -#else - st_uid = jnode->st_uid; - st_gid = jnode->st_gid; -#endif - - /* - * Check if I am owner or a group member or someone else. - */ - - flags_to_test = flags; - - if ( st_uid == jnode->st_uid ) - flags_to_test <<= 6; - else if ( st_gid == jnode->st_gid ) - flags_to_test <<= 3; - else { - /* must be other - do nothing */; - } - - /* - * If all of the flags are set we have permission - * to do this. - */ - if ( ( flags_to_test & jnode->st_mode) == flags_to_test ) - return 1; - - return 0; + loc->handlers = handlers; } -/* - * IMFS_evaluate_hard_link - * - * The following routine evaluates a hardlink to the actual node. - */ - -static int IMFS_evaluate_hard_link( - rtems_filesystem_location_info_t *node, /* IN/OUT */ - int flags /* IN */ +static bool IMFS_is_directory( + rtems_filesystem_eval_path_context_t *ctx, + void *arg ) { - IMFS_jnode_t *jnode = node->node_access; - int result = 0; + rtems_filesystem_location_info_t *currentloc = + rtems_filesystem_eval_path_get_currentloc( ctx ); + IMFS_jnode_t *node = currentloc->node_access; - /* - * Check for things that should never happen. - */ - IMFS_assert( jnode->type == IMFS_HARD_LINK ); - - /* - * Set the hard link value and the handlers. - */ - node->node_access = jnode->info.hard_link.link_node; - - IMFS_Set_handlers( node ); - - /* - * Verify we have the correct permissions for this node. - */ - - if ( !IMFS_evaluate_permission( node, flags ) ) - rtems_set_errno_and_return_minus_one( EACCES ); - - return result; + return node->type == IMFS_DIRECTORY; } - -/* - * IMFS_evaluate_sym_link - * - * The following routine evaluates a symbolic link to the actual node. - */ - -static int IMFS_evaluate_sym_link( - rtems_filesystem_location_info_t *node, /* IN/OUT */ - int flags /* IN */ +static IMFS_jnode_t *IMFS_search_in_directory( + IMFS_jnode_t *dir, + const char *token, + size_t tokenlen ) { - IMFS_jnode_t *jnode = node->node_access; - int result = 0; - int i; - - /* - * Check for things that should never happen. - */ - IMFS_assert( jnode->type == IMFS_SYM_LINK ); - IMFS_assert( jnode->Parent ); - - /* - * Move the node_access to either the symbolic links parent or - * root depending on the symbolic links path. - */ - node->node_access = jnode->Parent; - - rtems_filesystem_get_sym_start_loc( - jnode->info.sym_link.name, - &i, - node - ); - - /* - * Use eval path to evaluate the path of the symbolic link. - */ - result = IMFS_eval_path( - &jnode->info.sym_link.name[i], - strlen( &jnode->info.sym_link.name[i] ), - flags, - node - ); - - IMFS_Set_handlers( node ); - - /* - * Verify we have the correct permissions for this node. - */ - if ( !IMFS_evaluate_permission( node, flags ) ) - rtems_set_errno_and_return_minus_one( EACCES ); - - return result; -} + if ( rtems_filesystem_is_current_directory( token, tokenlen ) ) { + return dir; + } else { + if ( rtems_filesystem_is_parent_directory( token, tokenlen ) ) { + return dir->Parent; + } else { + rtems_chain_control *entries = &dir->info.directory.Entries; + rtems_chain_node *current = rtems_chain_first( entries ); + rtems_chain_node *tail = rtems_chain_tail( entries ); -/* - * IMFS_evaluate_link - * - * The following routine returns the real node pointed to by a link. - */ -int IMFS_evaluate_link( - rtems_filesystem_location_info_t *node, /* IN/OUT */ - int flags /* IN */ -) -{ - IMFS_jnode_t *jnode; - int result = 0; + while ( current != tail ) { + IMFS_jnode_t *entry = (IMFS_jnode_t *) current; + bool match = strncmp( entry->name, token, tokenlen ) == 0 + && entry->name [tokenlen] == '\0'; - do { - jnode = node->node_access; + if ( match ) { + return entry; + } - /* - * Increment and check the link counter. - */ + current = rtems_chain_next( current ); + } - rtems_filesystem_link_counts ++; - if ( rtems_filesystem_link_counts > MAXSYMLINK ) { - rtems_filesystem_link_counts = 0; - rtems_set_errno_and_return_minus_one( ELOOP ); + return NULL; } - - /* - * Follow the Link node. - */ - - if ( jnode->type == IMFS_HARD_LINK ) - result = IMFS_evaluate_hard_link( node, flags ); - - else if (jnode->type == IMFS_SYM_LINK ) - result = IMFS_evaluate_sym_link( node, flags ); - - } while ( ( result == 0 ) && ( ( jnode->type == IMFS_SYM_LINK ) || - ( jnode->type == IMFS_HARD_LINK ) ) ); - - /* - * Clear link counter. - */ - - rtems_filesystem_link_counts = 0; - - return result; -} - -/* - * IMFS_skip_separator - * - * Skip the separator in the path. - */ -static void IMFS_skip_separator ( - const char *path, /* IN */ - size_t *len, /* IN/OUT */ - int *index /* IN/OUT */ -) -{ - while ( IMFS_is_separator( path[*index] ) && path[*index] && *len ) { - ++(*index); - --(*len); } } -/* - * IMFS_evaluate_for_make - * - * The following routine evaluate path for a new node to be created. - * pathloc is returned with a pointer to the parent of the new node. - * name is returned with a pointer to the first character in the - * new node name. The parent node is verified to be a directory. - */ - -int IMFS_evaluate_for_make( - const char *path, /* IN */ - rtems_filesystem_location_info_t *pathloc, /* IN/OUT */ - const char **name /* OUT */ - ) +static rtems_filesystem_global_location_t **IMFS_is_mount_point( + IMFS_jnode_t *node +) { - int i = 0; - int len; - IMFS_token_types type; - char token[ IMFS_NAME_MAX + 1 ]; - IMFS_jnode_t *node; - bool done = false; - size_t pathlen; - int result; - - /* - * This was filled in by the caller and is valid in the - * mount table. - */ - node = pathloc->node_access; - - /* - * Get the path length. - */ - pathlen = strlen( path ); - /* - * Evaluate all tokens until we are done or an error occurs. - */ - - while( !done ) { - - type = IMFS_get_token( &path[i], pathlen, token, &len ); - pathlen -= len; - i += len; - - if ( !pathloc->node_access ) - rtems_set_errno_and_return_minus_one( ENOENT ); - - /* - * I cannot move out of this directory without execute permission. - */ + rtems_filesystem_global_location_t **fs_root_ptr = NULL; - if ( type != IMFS_NO_MORE_PATH ) - if ( node->type == IMFS_DIRECTORY ) - if ( !IMFS_evaluate_permission( pathloc, RTEMS_LIBIO_PERMS_SEARCH ) ) - rtems_set_errno_and_return_minus_one( EACCES ); - - node = pathloc->node_access; - - switch( type ) { - - case IMFS_UP_DIR: - /* - * Am I at the root of all filesystems? (chroot'ed?) - */ - - if ( pathloc->node_access == rtems_filesystem_root.node_access ) - break; /* Throw out the .. in this case */ - - - /* - * Am I at the root of this mounted filesystem? - */ - - if ( rtems_filesystem_is_root_location( pathloc ) ) { - - /* - * Am I at the root of all filesystems? - */ - - if ( pathloc->node_access == rtems_filesystem_root.node_access ) { - break; - - } else { - *pathloc = pathloc->mt_entry->mt_point_node; - return (*pathloc->ops->evalformake_h)( &path[i-len], pathloc, name ); - } - } else { - - if ( !node->Parent ) - rtems_set_errno_and_return_minus_one( ENOENT ); - - node = node->Parent; - } - - pathloc->node_access = node; - break; - - case IMFS_NAME: - - if ( node->type == IMFS_HARD_LINK ) { - - result = IMFS_evaluate_link( pathloc, 0 ); - if ( result == -1 ) - return -1; - - } else if ( node->type == IMFS_SYM_LINK ) { - - result = IMFS_evaluate_link( pathloc, 0 ); - - if ( result == -1 ) - return -1; - } - - node = pathloc->node_access; - if ( !node ) - rtems_set_errno_and_return_minus_one( ENOTDIR ); - - /* - * Only a directory can be decended into. - */ - - if ( node->type != IMFS_DIRECTORY ) - rtems_set_errno_and_return_minus_one( ENOTDIR ); - - /* - * Find the token name in the present location. - */ - - node = IMFS_find_match_in_dir( node, token ); - - /* - * If there is no node we have found the name of the node we - * wish to create. - */ - - if ( ! node ) - done = true; - else { - if (( node->type == IMFS_DIRECTORY ) && ( node->info.directory.mt_fs != NULL )) { - IMFS_skip_separator( path, &pathlen, &i); - if ((path[i] != '.') || (path[i + 1] != '.')) { - *pathloc = node->info.directory.mt_fs->mt_fs_root; - return (*pathloc->ops->evalformake_h)( &path[i], - pathloc, - name ); - } - i += 2; - pathlen -= 2; - node = node->Parent; - } - pathloc->node_access = node; - } - break; - - case IMFS_NO_MORE_PATH: - rtems_set_errno_and_return_minus_one( EEXIST ); - break; - - case IMFS_INVALID_TOKEN: - rtems_set_errno_and_return_minus_one( ENAMETOOLONG ); - break; - - case IMFS_CURRENT_DIR: - break; + if ( node->type == IMFS_DIRECTORY ) { + if ( node->info.directory.mt_fs != NULL ) { + fs_root_ptr = &node->info.directory.mt_fs->mt_fs_root; } } - *name = &path[ i - len ]; - - /* - * We have evaluated the path as far as we can. - * Verify there is not any invalid stuff at the end of the name. - */ - - for( ; path[i] != '\0'; i++) { - if ( !IMFS_is_separator( path[ i ] ) ) - rtems_set_errno_and_return_minus_one( ENOENT ); - } - - /* - * Verify we can execute and write to this directory. - */ - - result = IMFS_Set_handlers( pathloc ); - - /* - * The returned node must be a directory - */ - node = pathloc->node_access; - if ( node->type != IMFS_DIRECTORY ) - rtems_set_errno_and_return_minus_one( ENOTDIR ); - - /* - * We must have Write and execute permission on the returned node. - */ - - if ( !IMFS_evaluate_permission( pathloc, RTEMS_LIBIO_PERMS_WX ) ) - rtems_set_errno_and_return_minus_one( EACCES ); - - return result; + return fs_root_ptr; } -/* - * IMFS_eval_path - * - * The following routine evaluate path for a node that wishes to be - * accessed with mode. pathloc is returned with a pointer to the - * node to be accessed. - */ - -int IMFS_eval_path( - const char *pathname, /* IN */ - size_t pathnamelen, /* IN */ - int flags, /* IN */ - rtems_filesystem_location_info_t *pathloc /* IN/OUT */ - ) +static rtems_filesystem_eval_path_generic_status IMFS_eval_token( + rtems_filesystem_eval_path_context_t *ctx, + void *arg, + const char *token, + size_t tokenlen +) { - int i = 0; - int len; - IMFS_token_types type = IMFS_CURRENT_DIR; - char token[ IMFS_NAME_MAX + 1 ]; - IMFS_jnode_t *node; - int result; - - if ( !rtems_libio_is_valid_perms( flags ) ) { - rtems_set_errno_and_return_minus_one( EIO ); - } - - /* - * This was filled in by the caller and is valid in the - * mount table. - */ - - node = pathloc->node_access; - - /* - * Evaluate all tokens until we are done or an error occurs. - */ - - while( (type != IMFS_NO_MORE_PATH) && (type != IMFS_INVALID_TOKEN) ) { - - type = IMFS_get_token( &pathname[i], pathnamelen, token, &len ); - pathnamelen -= len; - i += len; - - if ( !pathloc->node_access ) - rtems_set_errno_and_return_minus_one( ENOENT ); + rtems_filesystem_eval_path_generic_status status = + RTEMS_FILESYSTEM_EVAL_PATH_GENERIC_DONE; + rtems_filesystem_location_info_t *currentloc = + rtems_filesystem_eval_path_get_currentloc( ctx ); + IMFS_jnode_t *dir = currentloc->node_access; + bool access_ok = rtems_filesystem_eval_path_check_access( + ctx, + RTEMS_LIBIO_PERMS_SEARCH, + dir->st_mode, + dir->st_uid, + dir->st_gid + ); - /* - * I cannot move out of this directory without execute permission. - */ - if ( type != IMFS_NO_MORE_PATH ) - if ( node->type == IMFS_DIRECTORY ) - if ( !IMFS_evaluate_permission( pathloc, RTEMS_LIBIO_PERMS_SEARCH ) ) - rtems_set_errno_and_return_minus_one( EACCES ); + if ( access_ok ) { + IMFS_jnode_t *entry = IMFS_search_in_directory( dir, token, tokenlen ); - node = pathloc->node_access; + if ( entry != NULL ) { + bool terminal = !rtems_filesystem_eval_path_has_path( ctx ); + int eval_flags = rtems_filesystem_eval_path_get_flags( ctx ); + bool follow_hard_link = (eval_flags & RTEMS_LIBIO_FOLLOW_HARD_LINK) != 0; + bool follow_sym_link = (eval_flags & RTEMS_LIBIO_FOLLOW_SYM_LINK) != 0; - switch( type ) { - case IMFS_UP_DIR: - /* - * Am I at the root of all filesystems? (chroot'ed?) - */ + rtems_filesystem_eval_path_clear_token( ctx ); - if ( pathloc->node_access == rtems_filesystem_root.node_access ) - break; /* Throw out the .. in this case */ + if ( entry->type == IMFS_HARD_LINK && (follow_hard_link || !terminal)) { + entry = entry->info.hard_link.link_node; + } - /* - * Am I at the root of this mounted filesystem? - */ + if ( entry->type == IMFS_SYM_LINK && (follow_sym_link || !terminal)) { + const char *target = entry->info.sym_link.name; - if ( rtems_filesystem_is_root_location( pathloc ) ) { + rtems_filesystem_eval_path_recursive( ctx, target, strlen( target ) ); + } else { + rtems_filesystem_global_location_t **fs_root_ptr = + IMFS_is_mount_point( entry ); - /* - * Am I at the root of all filesystems? - */ + if ( fs_root_ptr == NULL ) { + currentloc->node_access = entry; + IMFS_Set_handlers( currentloc ); - if ( pathloc->node_access == rtems_filesystem_root.node_access ) { - break; /* Throw out the .. in this case */ - } else { - *pathloc = pathloc->mt_entry->mt_point_node; - return (*pathloc->ops->evalpath_h)(&(pathname[i-len]), - pathnamelen+len, - flags,pathloc); + if ( !terminal ) { + status = RTEMS_FILESYSTEM_EVAL_PATH_GENERIC_CONTINUE; } } else { - - if ( !node->Parent ) - rtems_set_errno_and_return_minus_one( ENOENT ); - - node = node->Parent; - pathloc->node_access = node; - - } - - pathloc->node_access = node; - break; - - case IMFS_NAME: - /* - * If we are at a link follow it. - */ - if ( node->type == IMFS_HARD_LINK ) { - IMFS_evaluate_hard_link( pathloc, 0 ); - node = pathloc->node_access; - - /* - * It would be a design error if we evaluated the link and - * was broken. - */ - IMFS_assert( node ); - - } else if ( node->type == IMFS_SYM_LINK ) { - result = IMFS_evaluate_sym_link( pathloc, 0 ); - - /* - * In contrast to a hard link, it is possible to have a broken - * symbolic link. - */ - node = pathloc->node_access; - if ( result == -1 ) - return -1; - } - - /* - * Only a directory can be decended into. - */ - if ( node->type != IMFS_DIRECTORY ) - rtems_set_errno_and_return_minus_one( ENOTDIR ); - - /* - * Find the token name in the current node. - */ - node = IMFS_find_match_in_dir( node, token ); - if ( !node ) - rtems_set_errno_and_return_minus_one( ENOENT ); - - /* - * If we are at a node that is a mount point so current directory - * actually exists on the mounted file system and not in the node that - * contains the mount point node. For example a stat of the mount - * point should return the details of the root of the mounted file - * system not the mount point node of parent file system. - * - * If the node we have just moved to is a mount point do not loop and - * get the token because the token may be suitable for the mounted - * file system and not the IMFS. For example the IMFS length is - * limited. If the token is a parent directory move back up otherwise - * set loc to the new fs root node and let them finish evaluating the - * path. - */ - if (( node->type == IMFS_DIRECTORY ) && ( node->info.directory.mt_fs != NULL )) { - IMFS_skip_separator( pathname, &pathnamelen, &i); - if ((pathname[i] != '.') || (pathname[i + 1] != '.')) { - *pathloc = node->info.directory.mt_fs->mt_fs_root; - return (*pathloc->ops->evalpath_h)( &pathname[i], - pathnamelen, - flags, pathloc ); + access_ok = rtems_filesystem_eval_path_check_access( + ctx, + RTEMS_LIBIO_PERMS_EXEC, + entry->st_mode, + entry->st_uid, + entry->st_gid + ); + if ( access_ok ) { + rtems_filesystem_eval_path_restart( ctx, fs_root_ptr ); } - i += 2; - pathnamelen -= 2; - node = node->Parent; } - - /* - * Set the node access to the point we have found. - */ - pathloc->node_access = node; - break; - - case IMFS_NO_MORE_PATH: - case IMFS_CURRENT_DIR: - break; - - case IMFS_INVALID_TOKEN: - rtems_set_errno_and_return_minus_one( ENAMETOOLONG ); - break; - - } - } - - /* - * Always return the root node. - * - * If we are at a node that is a mount point. Set loc to the - * new fs root node and let let the mounted filesystem set the handlers. - * - * NOTE: The behavior of stat() on a mount point appears to be questionable. - */ - - if ( node->type == IMFS_DIRECTORY ) { - if ( node->info.directory.mt_fs != NULL ) { - *pathloc = node->info.directory.mt_fs->mt_fs_root; - return (*pathloc->ops->evalpath_h)( &pathname[i-len], - pathnamelen+len, - flags, pathloc ); + } } else { - result = IMFS_Set_handlers( pathloc ); + status = RTEMS_FILESYSTEM_EVAL_PATH_GENERIC_NO_ENTRY; } - } else { - result = IMFS_Set_handlers( pathloc ); } - /* - * Verify we have the correct permissions for this node. - */ + return status; +} - if ( !IMFS_evaluate_permission( pathloc, flags ) ) - rtems_set_errno_and_return_minus_one( EACCES ); +static const rtems_filesystem_eval_path_generic_config IMFS_eval_config = { + .is_directory = IMFS_is_directory, + .eval_token = IMFS_eval_token +}; - return result; +void IMFS_eval_path( rtems_filesystem_eval_path_context_t *ctx ) +{ + rtems_filesystem_eval_path_generic( ctx, NULL, &IMFS_eval_config ); } |