646 lines
14 KiB
C
646 lines
14 KiB
C
/*
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* Copyright (c) 2007 Vreixo Formoso
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*
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* This file is part of the libisofs project; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation. See COPYING file for details.
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*/
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/*
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* Filesystem/FileSource implementation to access the local filesystem.
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*/
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#include "fsource.h"
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#include "util.h"
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#include <stdlib.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <fcntl.h>
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#include <errno.h>
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#include <dirent.h>
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#include <unistd.h>
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#include <libgen.h>
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#include <string.h>
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static
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int iso_file_source_new_lfs(IsoFileSource *parent, const char *name,
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IsoFileSource **src);
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/*
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* We can share a local filesystem object, as it has no private atts.
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*/
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IsoFilesystem *lfs= NULL;
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typedef struct
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{
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/** reference to the parent (if root it points to itself) */
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IsoFileSource *parent;
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char *name;
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unsigned int openned :2; /* 0: not openned, 1: file, 2:dir */
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union
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{
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int fd;
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DIR *dir;
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} info;
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} _LocalFsFileSource;
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static
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char* lfs_get_path(IsoFileSource *src)
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{
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_LocalFsFileSource *data;
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data = src->data;
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if (data->parent == src) {
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return strdup("/");
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} else {
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char *path = lfs_get_path(data->parent);
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int pathlen = strlen(path);
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path = realloc(path, pathlen + strlen(data->name) + 2);
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if (pathlen != 1) {
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/* pathlen can only be 1 for root */
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path[pathlen] = '/';
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path[pathlen + 1] = '\0';
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}
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return strcat(path, data->name);
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}
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}
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static
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char* lfs_get_name(IsoFileSource *src)
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{
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_LocalFsFileSource *data;
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data = src->data;
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return strdup(data->name);
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}
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static
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int lfs_lstat(IsoFileSource *src, struct stat *info)
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{
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_LocalFsFileSource *data;
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char *path;
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if (src == NULL || info == NULL) {
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return ISO_NULL_POINTER;
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}
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data = src->data;
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path = lfs_get_path(src);
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if (lstat(path, info) != 0) {
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int err;
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/* error, choose an appropriate return code */
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switch (errno) {
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case EACCES:
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err = ISO_FILE_ACCESS_DENIED;
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break;
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case ENOTDIR:
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case ENAMETOOLONG:
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case ELOOP:
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err = ISO_FILE_BAD_PATH;
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break;
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case ENOENT:
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err = ISO_FILE_DOESNT_EXIST;
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break;
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case EFAULT:
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case ENOMEM:
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err = ISO_OUT_OF_MEM;
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break;
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default:
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err = ISO_FILE_ERROR;
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break;
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}
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return err;
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}
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free(path);
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return ISO_SUCCESS;
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}
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static
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int lfs_stat(IsoFileSource *src, struct stat *info)
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{
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_LocalFsFileSource *data;
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char *path;
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if (src == NULL || info == NULL) {
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return ISO_NULL_POINTER;
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}
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data = src->data;
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path = lfs_get_path(src);
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if (stat(path, info) != 0) {
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int err;
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/* error, choose an appropriate return code */
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switch (errno) {
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case EACCES:
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err = ISO_FILE_ACCESS_DENIED;
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break;
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case ENOTDIR:
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case ENAMETOOLONG:
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case ELOOP:
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err = ISO_FILE_BAD_PATH;
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break;
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case ENOENT:
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err = ISO_FILE_DOESNT_EXIST;
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break;
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case EFAULT:
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case ENOMEM:
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err = ISO_OUT_OF_MEM;
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break;
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default:
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err = ISO_FILE_ERROR;
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break;
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}
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return err;
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}
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free(path);
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return ISO_SUCCESS;
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}
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static
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int lfs_access(IsoFileSource *src)
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{
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int ret;
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_LocalFsFileSource *data;
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char *path;
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if (src == NULL) {
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return ISO_NULL_POINTER;
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}
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data = src->data;
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path = lfs_get_path(src);
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ret = iso_eaccess(path);
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free(path);
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return ret;
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}
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static
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int lfs_open(IsoFileSource *src)
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{
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int err;
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struct stat info;
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_LocalFsFileSource *data;
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char *path;
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if (src == NULL) {
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return ISO_NULL_POINTER;
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}
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data = src->data;
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if (data->openned) {
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return ISO_FILE_ALREADY_OPENNED;
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}
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/* is a file or a dir ? */
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err = lfs_stat(src, &info);
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if (err < 0) {
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return err;
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}
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path = lfs_get_path(src);
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if (S_ISDIR(info.st_mode)) {
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data->info.dir = opendir(path);
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data->openned = data->info.dir ? 2 : 0;
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} else {
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data->info.fd = open(path, O_RDONLY);
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data->openned = data->info.fd != -1 ? 1 : 0;
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}
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free(path);
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/*
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* check for possible errors, note that many of possible ones are
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* parsed in the lstat call above
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*/
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if (data->openned == 0) {
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switch (errno) {
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case EACCES:
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err = ISO_FILE_ACCESS_DENIED;
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break;
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case EFAULT:
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case ENOMEM:
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err = ISO_OUT_OF_MEM;
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break;
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default:
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err = ISO_FILE_ERROR;
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break;
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}
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return err;
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}
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return ISO_SUCCESS;
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}
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static
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int lfs_close(IsoFileSource *src)
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{
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int ret;
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_LocalFsFileSource *data;
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if (src == NULL) {
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return ISO_NULL_POINTER;
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}
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data = src->data;
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switch (data->openned) {
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case 1: /* not dir */
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ret = close(data->info.fd) == 0 ? ISO_SUCCESS : ISO_FILE_ERROR;
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break;
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case 2: /* directory */
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ret = closedir(data->info.dir) == 0 ? ISO_SUCCESS : ISO_FILE_ERROR;
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break;
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default:
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ret = ISO_FILE_NOT_OPENNED;
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break;
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}
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if (ret == ISO_SUCCESS) {
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data->openned = 0;
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}
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return ret;
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}
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static
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int lfs_read(IsoFileSource *src, void *buf, size_t count)
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{
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_LocalFsFileSource *data;
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if (src == NULL || buf == NULL) {
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return ISO_NULL_POINTER;
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}
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if (count == 0) {
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return ISO_WRONG_ARG_VALUE;
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}
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data = src->data;
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switch (data->openned) {
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case 1: /* not dir */
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{
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int ret;
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ret = read(data->info.fd, buf, count);
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if (ret < 0) {
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/* error on read */
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switch (errno) {
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case EINTR:
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ret = ISO_INTERRUPTED;
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break;
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case EFAULT:
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ret = ISO_OUT_OF_MEM;
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break;
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case EIO:
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ret = ISO_FILE_READ_ERROR;
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break;
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default:
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ret = ISO_FILE_ERROR;
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break;
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}
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}
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return ret;
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}
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case 2: /* directory */
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return ISO_FILE_IS_DIR;
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default:
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return ISO_FILE_NOT_OPENNED;
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}
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}
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static
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int lfs_readdir(IsoFileSource *src, IsoFileSource **child)
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{
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_LocalFsFileSource *data;
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if (src == NULL || child == NULL) {
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return ISO_NULL_POINTER;
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}
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data = src->data;
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switch (data->openned) {
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case 1: /* not dir */
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return ISO_FILE_IS_NOT_DIR;
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case 2: /* directory */
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{
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struct dirent *entry;
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int ret;
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/* while to skip "." and ".." dirs */
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while (1) {
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entry = readdir(data->info.dir);
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if (entry == NULL) {
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if (errno == EBADF)
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return ISO_FILE_ERROR;
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else
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return 0; /* EOF */
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}
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if (strcmp(entry->d_name, ".") && strcmp(entry->d_name, "..")) {
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break;
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}
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}
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/* create the new FileSrc */
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ret = iso_file_source_new_lfs(src, entry->d_name, child);
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return ret;
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}
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default:
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return ISO_FILE_NOT_OPENNED;
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}
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}
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static
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int lfs_readlink(IsoFileSource *src, char *buf, size_t bufsiz)
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{
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int size;
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_LocalFsFileSource *data;
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char *path;
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if (src == NULL || buf == NULL) {
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return ISO_NULL_POINTER;
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}
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if (bufsiz <= 0) {
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return ISO_WRONG_ARG_VALUE;
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}
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data = src->data;
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path = lfs_get_path(src);
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/*
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* invoke readlink, with bufsiz -1 to reserve an space for
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* the NULL character
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*/
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size = readlink(path, buf, bufsiz - 1);
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free(path);
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if (size < 0) {
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/* error */
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switch (errno) {
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case EACCES:
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return ISO_FILE_ACCESS_DENIED;
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case ENOTDIR:
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case ENAMETOOLONG:
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case ELOOP:
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return ISO_FILE_BAD_PATH;
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case ENOENT:
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return ISO_FILE_DOESNT_EXIST;
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case EINVAL:
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return ISO_FILE_IS_NOT_SYMLINK;
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case EFAULT:
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case ENOMEM:
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return ISO_OUT_OF_MEM;
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default:
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return ISO_FILE_ERROR;
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}
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}
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/* NULL-terminate the buf */
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buf[size] = '\0';
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return ISO_SUCCESS;
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}
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static
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IsoFilesystem* lfs_get_filesystem(IsoFileSource *src)
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{
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return src == NULL ? NULL : lfs;
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}
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static
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void lfs_free(IsoFileSource *src)
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{
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_LocalFsFileSource *data;
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data = src->data;
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/* close the file if it is already openned */
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if (data->openned) {
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src->class->close(src);
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}
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if (data->parent != src) {
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iso_file_source_unref(data->parent);
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}
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free(data->name);
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free(data);
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iso_filesystem_unref(lfs);
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}
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IsoFileSourceIface lfs_class = {
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0, /* version */
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lfs_get_path,
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lfs_get_name,
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lfs_lstat,
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lfs_stat,
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lfs_access,
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lfs_open,
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lfs_close,
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lfs_read,
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lfs_readdir,
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lfs_readlink,
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lfs_get_filesystem,
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lfs_free
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};
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/**
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*
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* @return
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* 1 success, < 0 error
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*/
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static
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int iso_file_source_new_lfs(IsoFileSource *parent, const char *name,
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IsoFileSource **src)
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{
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IsoFileSource *lfs_src;
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_LocalFsFileSource *data;
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if (src == NULL) {
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return ISO_NULL_POINTER;
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}
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if (lfs == NULL) {
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/* this should never happen */
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return ISO_ASSERT_FAILURE;
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}
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/* allocate memory */
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data = malloc(sizeof(_LocalFsFileSource));
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if (data == NULL) {
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return ISO_OUT_OF_MEM;
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}
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lfs_src = malloc(sizeof(IsoFileSource));
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if (lfs_src == NULL) {
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free(data);
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return ISO_OUT_OF_MEM;
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}
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/* fill struct */
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data->name = name ? strdup(name) : NULL;
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data->openned = 0;
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if (parent) {
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data->parent = parent;
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iso_file_source_ref(parent);
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} else {
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data->parent = lfs_src;
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}
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lfs_src->refcount = 1;
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lfs_src->data = data;
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lfs_src->class = &lfs_class;
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/* take a ref to local filesystem */
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iso_filesystem_ref(lfs);
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/* return */
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*src = lfs_src;
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return ISO_SUCCESS;
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}
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static
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int lfs_get_root(IsoFilesystem *fs, IsoFileSource **root)
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{
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if (fs == NULL || root == NULL) {
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return ISO_NULL_POINTER;
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}
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return iso_file_source_new_lfs(NULL, NULL, root);
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}
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static
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int lfs_get_by_path(IsoFilesystem *fs, const char *path, IsoFileSource **file)
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{
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int ret;
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IsoFileSource *src;
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struct stat info;
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char *ptr, *brk_info, *component;
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if (fs == NULL || path == NULL || file == NULL) {
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return ISO_NULL_POINTER;
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}
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/*
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* first of all check that it is a valid path.
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*/
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if (lstat(path, &info) != 0) {
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int err;
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/* error, choose an appropriate return code */
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switch (errno) {
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case EACCES:
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err = ISO_FILE_ACCESS_DENIED;
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break;
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case ENOTDIR:
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case ENAMETOOLONG:
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case ELOOP:
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err = ISO_FILE_BAD_PATH;
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break;
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case ENOENT:
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err = ISO_FILE_DOESNT_EXIST;
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break;
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case EFAULT:
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case ENOMEM:
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err = ISO_OUT_OF_MEM;
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break;
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default:
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err = ISO_FILE_ERROR;
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break;
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}
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return err;
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}
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/* ok, path is valid. create the file source */
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ret = lfs_get_root(fs, &src);
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if (ret < 0) {
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return ret;
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}
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if (!strcmp(path, "/")) {
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/* we are looking for root */
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*file = src;
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return ISO_SUCCESS;
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}
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ptr = strdup(path);
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if (ptr == NULL) {
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iso_file_source_unref(src);
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return ISO_OUT_OF_MEM;
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}
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component = strtok_r(ptr, "/", &brk_info);
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while (component) {
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IsoFileSource *child = NULL;
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if (!strcmp(component, ".")) {
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child = src;
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} else if (!strcmp(component, "..")) {
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child = ((_LocalFsFileSource*)src->data)->parent;
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iso_file_source_ref(child);
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iso_file_source_unref(src);
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} else {
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ret = iso_file_source_new_lfs(src, component, &child);
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iso_file_source_unref(src);
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if (ret < 0) {
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break;
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}
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}
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src = child;
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component = strtok_r(NULL, "/", &brk_info);
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}
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free(ptr);
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if (ret > 0) {
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*file = src;
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}
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return ret;
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}
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static
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unsigned int lfs_get_id(IsoFilesystem *fs)
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{
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return ISO_LOCAL_FS_ID;
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}
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static
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int lfs_fs_open(IsoFilesystem *fs)
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{
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/* open() operation is not needed */
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return ISO_SUCCESS;
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}
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static
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int lfs_fs_close(IsoFilesystem *fs)
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{
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/* close() operation is not needed */
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return ISO_SUCCESS;
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}
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static
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void lfs_fs_free(IsoFilesystem *fs)
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{
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lfs = NULL;
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}
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|
|
|
int iso_local_filesystem_new(IsoFilesystem **fs)
|
|
{
|
|
if (fs == NULL) {
|
|
return ISO_NULL_POINTER;
|
|
}
|
|
|
|
if (lfs != NULL) {
|
|
/* just take a new ref */
|
|
iso_filesystem_ref(lfs);
|
|
} else {
|
|
|
|
lfs = malloc(sizeof(IsoFilesystem));
|
|
if (lfs == NULL) {
|
|
return ISO_OUT_OF_MEM;
|
|
}
|
|
|
|
/* fill struct */
|
|
strncpy(lfs->type, "file", 4);
|
|
lfs->refcount = 1;
|
|
lfs->version = 0;
|
|
lfs->data = NULL; /* we don't need private data */
|
|
lfs->get_root = lfs_get_root;
|
|
lfs->get_by_path = lfs_get_by_path;
|
|
lfs->get_id = lfs_get_id;
|
|
lfs->open = lfs_fs_open;
|
|
lfs->close = lfs_fs_close;
|
|
lfs->free = lfs_fs_free;
|
|
}
|
|
*fs = lfs;
|
|
return ISO_SUCCESS;
|
|
}
|