busybox/archival/libunarchive/unarchive.c

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2001-10-25 19:48:08 +05:30
/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 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 Library 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.
*/
#include <errno.h>
#include <fnmatch.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <utime.h>
#include <sys/wait.h>
#include <signal.h>
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#include "unarchive.h"
#include "busybox.h"
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/* Extract the data postioned at src_stream to either filesystem, stdout or
* buffer depending on the value of 'function' which is defined in libbb.h
*
* prefix doesnt have to be just a directory, it may prefix the filename as well.
*
* e.g. '/var/lib/dpkg/info/dpkg.' will extract all files to the base bath
* '/var/lib/dpkg/info/' and all files/dirs created in that dir will have
* 'dpkg.' as their prefix
*
* For this reason if prefix does point to a dir then it must end with a
* trailing '/' or else the last dir will be assumed to be the file prefix
*/
char *extract_archive(FILE *src_stream, FILE *out_stream, const file_header_t *file_entry,
const int function, const char *prefix)
{
FILE *dst_stream = NULL;
char *full_name = NULL;
char *buffer = NULL;
struct utimbuf t;
/* prefix doesnt have to be a proper path it may prepend
* the filename as well */
if (prefix != NULL) {
/* strip leading '/' in filename to extract as prefix may not be dir */
/* Cant use concat_path_file here as prefix might not be a directory */
char *path = file_entry->name;
if (strncmp("./", path, 2) == 0) {
path += 2;
if (strlen(path) == 0) {
return(NULL);
}
}
bb_asprintf(&full_name, "%s%s", prefix, path);
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} else {
full_name = file_entry->name;
}
if (function & extract_to_stdout) {
if (S_ISREG(file_entry->mode)) {
copy_file_chunk(src_stream, out_stream, file_entry->size);
archive_offset += file_entry->size;
}
}
else if (function & extract_one_to_buffer) {
if (S_ISREG(file_entry->mode)) {
buffer = (char *) xmalloc(file_entry->size + 1);
fread(buffer, 1, file_entry->size, src_stream);
buffer[file_entry->size] = '\0';
archive_offset += file_entry->size;
return(buffer);
}
}
else if (function & extract_all_to_fs) {
struct stat oldfile;
int stat_res;
stat_res = lstat (full_name, &oldfile);
if (stat_res == 0) { /* The file already exists */
if ((function & extract_unconditional) || (oldfile.st_mtime < file_entry->mtime)) {
if (!S_ISDIR(oldfile.st_mode)) {
unlink(full_name); /* Directories might not be empty etc */
}
} else {
if ((function & extract_quiet) != extract_quiet) {
error_msg("%s not created: newer or same age file exists", file_entry->name);
}
seek_sub_file(src_stream, file_entry->size);
return (NULL);
}
}
if (function & extract_create_leading_dirs) { /* Create leading directories with default umask */
char *buf, *parent;
buf = xstrdup(full_name);
parent = dirname(buf);
if (make_directory (parent, -1, FILEUTILS_RECUR) != 0) {
if ((function & extract_quiet) != extract_quiet) {
error_msg("couldn't create leading directories");
}
}
free (buf);
}
switch(file_entry->mode & S_IFMT) {
case S_IFREG:
if (file_entry->link_name) { /* Found a cpio hard link */
if (link(file_entry->link_name, full_name) != 0) {
if ((function & extract_quiet) != extract_quiet) {
perror_msg("Cannot link from %s to '%s'",
file_entry->name, file_entry->link_name);
}
}
} else {
if ((dst_stream = wfopen(full_name, "w")) == NULL) {
seek_sub_file(src_stream, file_entry->size);
return NULL;
}
archive_offset += file_entry->size;
if (file_entry->extract_func) file_entry->extract_func(src_stream, dst_stream);
else copy_file_chunk(src_stream, dst_stream, file_entry->size);
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fclose(dst_stream);
}
break;
case S_IFDIR:
if (stat_res != 0) {
if (mkdir(full_name, file_entry->mode) < 0) {
if ((function & extract_quiet) != extract_quiet) {
perror_msg("extract_archive: %s", full_name);
}
}
}
break;
case S_IFLNK:
if (symlink(file_entry->link_name, full_name) < 0) {
if ((function & extract_quiet) != extract_quiet) {
perror_msg("Cannot create symlink from %s to '%s'", file_entry->name, file_entry->link_name);
}
return NULL;
}
break;
case S_IFSOCK:
case S_IFBLK:
case S_IFCHR:
case S_IFIFO:
if (mknod(full_name, file_entry->mode, file_entry->device) == -1) {
if ((function & extract_quiet) != extract_quiet) {
perror_msg("Cannot create node %s", file_entry->name);
}
return NULL;
}
break;
}
/* Changing a symlink's properties normally changes the properties of the
* file pointed to, so dont try and change the date or mode, lchown does
* does the right thing, but isnt available in older versions of libc */
if (S_ISLNK(file_entry->mode)) {
#if (__GLIBC__ > 2) && (__GLIBC_MINOR__ > 1)
lchown(full_name, file_entry->uid, file_entry->gid);
#endif
} else {
if (function & extract_preserve_date) {
t.actime = file_entry->mtime;
t.modtime = file_entry->mtime;
utime(full_name, &t);
}
chmod(full_name, file_entry->mode);
chown(full_name, file_entry->uid, file_entry->gid);
}
} else {
/* If we arent extracting data we have to skip it,
* if data size is 0 then then just do it anyway
* (saves testing for it) */
seek_sub_file(src_stream, file_entry->size);
}
/* extract_list and extract_verbose_list can be used in conjunction
* with one of the above four extraction functions, so do this seperately */
if (function & extract_verbose_list) {
fprintf(out_stream, "%s %d/%d %8d %s ", mode_string(file_entry->mode),
file_entry->uid, file_entry->gid,
(int) file_entry->size, time_string(file_entry->mtime));
}
if ((function & extract_list) || (function & extract_verbose_list)){
/* fputs doesnt add a trailing \n, so use fprintf */
fprintf(out_stream, "%s\n", full_name);
}
if (prefix != NULL) {
free(full_name);
}
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return(NULL); /* Maybe we should say if failed */
}
char *unarchive(FILE *src_stream, FILE *out_stream, file_header_t *(*get_headers)(FILE *),
const int extract_function, const char *prefix, char **include_name, char **exclude_name)
{
file_header_t *file_entry;
int extract_flag = TRUE;
int i;
char *buffer = NULL;
#ifdef CONFIG_FEATURE_UNARCHIVE_TAPE
int pid, tape_pipe[2];
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if (pipe(tape_pipe) != 0) error_msg_and_die("Can't create pipe\n");
if ((pid = fork()) == -1) error_msg_and_die("Fork failed\n");
if (pid==0) { /* child process */
close(tape_pipe[0]); /* We don't wan't to read from the pipe */
copyfd(fileno(src_stream), tape_pipe[1]);
close(tape_pipe[1]); /* Send EOF */
exit(0);
/* notreached */
}
close(tape_pipe[1]); /* Don't want to write down the pipe */
fclose(src_stream);
src_stream = fdopen(tape_pipe[0], "r");
#endif
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archive_offset = 0;
while ((file_entry = get_headers(src_stream)) != NULL) {
if (include_name != NULL) {
extract_flag = FALSE;
for(i = 0; include_name[i] != 0; i++) {
if (fnmatch(include_name[i], file_entry->name, FNM_LEADING_DIR) == 0) {
extract_flag = TRUE;
break;
}
}
} else {
extract_flag = TRUE;
}
/* If the file entry is in the exclude list dont extract it */
if (exclude_name != NULL) {
for(i = 0; exclude_name[i] != 0; i++) {
if (fnmatch(exclude_name[i], file_entry->name, FNM_LEADING_DIR) == 0) {
extract_flag = FALSE;
break;
}
}
}
if (extract_flag) {
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buffer = extract_archive(src_stream, out_stream, file_entry, extract_function, prefix);
} else {
/* seek past the data entry */
seek_sub_file(src_stream, file_entry->size);
}
free(file_entry->name);
free(file_entry->link_name);
free(file_entry);
}
#ifdef CONFIG_FEATURE_UNARCHIVE_TAPE
kill(pid, SIGTERM);
waitpid(pid, NULL, 0);
#endif
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return(buffer);
}