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libr/src/tempfiles.c

322 lines
7.5 KiB

10 years ago
/*
*
* Copyright (c) 2009 Erich Hoover
*
* libr temp files - Handle temporary files and handles that require cleanup
* when libr closes.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* To provide feedback, report bugs, or otherwise contact me:
* ehoover at mines dot edu
*
*/
#include "tempfiles.h"
/* For malloc/free and mkdtemp */
#include <stdlib.h>
/* For string handling */
#include <string.h>
#include <stdio.h>
/* For directory cleanup */
#include <unistd.h>
#include <dirent.h>
/* For directory creation */
#include <sys/stat.h>
#include <sys/types.h>
#include <errno.h>
#if defined(__FreeBSD__)
#include <sys/syslimits.h>
#endif
10 years ago
#ifndef FALSE
#define FALSE 0
#endif
#ifndef TRUE
#define TRUE 1
#endif
#ifndef DOXYGEN_SHOULD_SKIP_THIS
/* Hold on to folder names for cleanup when libr is removed from memory */
typedef struct CLEANUPFOLDER {
char *folder;
struct CLEANUPFOLDER *next;
} CleanupFolder;
CleanupFolder *folders_to_remove = NULL;
/* Hold on to libr handles for cleanup when libr is removed from memory */
typedef struct CLEANUPHANDLE {
int internal; /* do not warn the user about cleaning this handle up */
libr_file *handle;
struct CLEANUPHANDLE *next;
} CleanupHandle;
CleanupHandle *handles_to_remove = NULL;
#endif /* DOXYGEN_SHOULD_SKIP_THIS */
/*
* Register a folder for cleanup when libr is removed from memory
*/
void register_folder_cleanup(char *temp_folder)
{
CleanupFolder *folder = malloc(sizeof(CleanupFolder));
folder->folder = strdup(temp_folder);
folder->next = NULL;
if(folders_to_remove != NULL)
{
CleanupFolder *f;
for(f = folders_to_remove; f->next != NULL; f = f->next) {}
f->next = folder;
}
else
folders_to_remove = folder;
}
/*
* Register a libr handle for cleanup when libr is removed from memory
*/
void register_handle_cleanup(libr_file *handle)
{
CleanupHandle *h = malloc(sizeof(CleanupHandle));
h->handle = handle;
h->internal = FALSE;
h->next = NULL;
if(handles_to_remove != NULL)
{
CleanupHandle *i;
for(i = handles_to_remove; i->next != NULL; i = i->next) {}
i->next = h;
}
else
handles_to_remove = h;
}
/*
* Remove a libr handle from the cleanup list
*/
void unregister_handle_cleanup(libr_file *handle)
{
CleanupHandle *i, *last = NULL;
int found = FALSE;
if(handles_to_remove == NULL)
{
printf("Unregistering handle with no list of cleanup handles!\n");
return;
}
for(i = handles_to_remove; i != NULL; last = i, i = i->next)
{
if(i->handle == handle)
{
if(last == NULL)
handles_to_remove = i->next;
else
last->next = i->next;
free(i);
found = TRUE;
break;
}
}
if(!found)
printf("Could not find handle to remove from cleanup list!\n");
}
/*
* Flag a handle as internal (do not warn about unsafe cleanup)
*/
void register_internal_handle(libr_file *handle)
{
int found = FALSE;
CleanupHandle *i;
if(handles_to_remove == NULL)
{
printf("No cleanup list!\n");
return;
}
for(i = handles_to_remove; i != NULL; i = i->next)
{
if(i->handle == handle)
{
i->internal = TRUE;
found = TRUE;
break;
}
}
if(!found)
printf("Could not find handle in cleanup list!\n");
}
/*
* Cleanup a temporary folder used to hack the inability to load resources from a buffer
*/
void cleanup_folder(char *temp_folder)
{
char *filepath = (char *) malloc(PATH_MAX);
DIR *dir = opendir(temp_folder);
struct dirent *file;
while((file = readdir(dir)) != NULL)
{
char *filename = file->d_name;
/* Do not delete "self" or "parent" directory entries */
if(!strcmp(filename, ".") || !strcmp(filename, ".."))
continue;
/* But delete anything else */
strcpy(filepath, temp_folder);
strcat(filepath, "/");
strcat(filepath, filename);
if(file->d_type == DT_DIR)
cleanup_folder(filepath);
else
{
if(unlink(filepath))
printf("libr failed to cleanup '%s' in temporary folder: %m\n", filename);
}
}
free(filepath);
closedir(dir);
if(rmdir(temp_folder) != 0)
printf("libr failed to remove temporary folder: %m\n");
}
/*
* Perform cleanup when libr is removed from memory
*/
void do_cleanup(void) __attribute__((destructor));
void do_cleanup(void)
{
CleanupFolder *f, *fnext;
CleanupHandle *h, *hnext;
/* Cleanup folders */
for(f = folders_to_remove; f != NULL; f = fnext)
{
folders_to_remove = NULL;
fnext = f->next;
cleanup_folder(f->folder);
free(f->folder);
free(f);
}
/* Cleanup handles */
for(h = handles_to_remove; h != NULL; h = hnext)
{
handles_to_remove = NULL;
hnext = h->next;
/* Unless the handle was created internally then warn the developer to cleanup their act */
if(!h->internal)
printf("Warning: Application did not cleanup resource handle: %p\n", h->handle);
libr_close_internal(h->handle);
free(h);
}
}
/*
* Build all the directories required by a resource
* (and construct the output string)
*/
int make_valid_path(char *out_path, size_t maxpath, char *start_folder, char *resource_name)
{
char *a, *c = resource_name;
strcpy(out_path, start_folder);
while((a=strchr(c, '/')) != NULL)
{
strcat(out_path, "/");
strncat(out_path, c, (size_t) (a-c));
if(mkdir(out_path, S_IRUSR|S_IWUSR|S_IXUSR) != 0)
{
if(errno != EEXIST)
{
printf("failed to make directory: %s %m\n", out_path);
return false;
}
}
c = a+1;
}
strcat(out_path, "/");
strcat(out_path, c);
return true;
}
/*
* Extract all the resources from the ELF file for use by the resource loader
*/
char *libr_extract_resources(libr_file *handle)
{
char *temp_mask = strdup(LIBR_TEMPFILE);
char *temp_folder;
int i = 0;
temp_folder = mkdtemp(temp_mask);
if(temp_folder == NULL)
{
/* failed to extract ELF resources, could not create a temporary path */
goto failed;
}
/* If this library cannot dynamically load resources then pull out all the resources to a temporary directory */
for(i=0;i<libr_resources(handle);i++)
{
char *resource_name = libr_list(handle, i);
char *file_path[PATH_MAX];
size_t resource_size;
FILE *file_handle;
char *resource;
resource = libr_malloc(handle, resource_name, &resource_size);
if(!make_valid_path((char *)file_path, sizeof(file_path), temp_folder, resource_name))
{
/* failed to build the path required by a resource */
cleanup_folder(temp_folder);
temp_folder = NULL;
goto failed;
}
file_handle = fopen((const char *) file_path, "w");
if(file_handle == NULL)
{
/* failed to extract ELF resources, could not write to temporary path */
cleanup_folder(temp_folder);
temp_folder = NULL;
goto failed;
}
/* if the resource is empty then fwrite will fail */
if( (resource_size != 0) && (fwrite(resource, resource_size, 1, file_handle) != 1) )
{
/* failed to extract ELF resources, temporary path out of space? */
cleanup_folder(temp_folder);
temp_folder = NULL;
goto failed;
}
fclose(file_handle);
free(resource);
}
failed:
if(temp_folder != NULL)
temp_folder = strdup(temp_folder);
free(temp_mask);
return temp_folder;
}