char *unarchive(FILE *src_stream, FILE *out_stream, file_header_t *(*get_headers)(FILE *),
const int extract_function, const char *prefix, char **extract_names)
{
file_header_t *file_entry;
int extract_flag;
int i;
char *buffer = NULL;
archive_offset = 0;
while ((file_entry = get_headers(src_stream)) != NULL) {
extract_flag = TRUE;
if (extract_names != NULL) {
int found_flag = FALSE;
for(i = 0; extract_names[i] != 0; i++) {
if (strcmp(extract_names[i], file_entry->name) == 0) {
found_flag = TRUE;
break;
}
}
if (extract_function & extract_exclude_list) {
if (found_flag == TRUE) {
extract_flag = FALSE;
}
} else {
/* If its not found in the include list dont extract it */
if (found_flag == FALSE) {
extract_flag = FALSE;
}
}
}
if (extract_flag == TRUE) {
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); /* may be null, but doesn't matter */
free(file_entry->link_name);
free(file_entry);
}
return(buffer);
}
/* Extract the data postioned at src_stream to either filesystem, stdout or
* buffer depending on the value of 'function' which is defined in bbtargz.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
*/
static char *
extract_archive(FILE *src_stream, FILE *out_stream,
const file_header_t *file_entry, const int function,
const char *prefix,
int *err)
{
FILE *dst_stream = NULL;
char *full_name = NULL;
char *full_link_name = NULL;
char *buffer = NULL;
struct utimbuf t;
*err = 0;
/* 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)
/* Do nothing, current dir already exists. */
return NULL;
}
full_name = xmalloc(strlen(prefix) + strlen(path) + 1);
strcpy(full_name, prefix);
strcat(full_name, path);
if ( file_entry->link_name ){
full_link_name = xmalloc(strlen(prefix) + strlen(file_entry->link_name) + 1);
strcpy(full_link_name, prefix);
strcat(full_link_name, file_entry->link_name);
}
} else {
full_name = xstrdup(file_entry->name);
if ( file_entry->link_name )
full_link_name = xstrdup(file_entry->link_name);
}
if (function & extract_to_stream) {
if (S_ISREG(file_entry->mode)) {
*err = 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;
goto cleanup;
}
}
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) {
*err = -1;
error_msg("%s not created: newer or same age file exists", file_entry->name);
}
seek_sub_file(src_stream, file_entry->size);
goto cleanup;
}
}
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) {
*err = -1;
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(full_link_name, full_name) != 0) {
if ((function & extract_quiet) != extract_quiet) {
*err = -1;
perror_msg("Cannot link from %s to '%s'",
file_entry->name, file_entry->link_name);
}
}
} else {
if ((dst_stream = wfopen(full_name, "w")) == NULL) {
*err = -1;
seek_sub_file(src_stream, file_entry->size);
goto cleanup;
}
archive_offset += file_entry->size;
*err = copy_file_chunk(src_stream, dst_stream, file_entry->size);
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) {
*err = -1;
perror_msg("Cannot make dir %s", full_name);
}
}
}
break;
case S_IFLNK:
if (symlink(file_entry->link_name, full_name) < 0) {
if ((function & extract_quiet) != extract_quiet) {
*err = -1;
perror_msg("Cannot create symlink from %s to '%s'", file_entry->name, file_entry->link_name);
}
goto cleanup;
}
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) {
*err = -1;
perror_msg("Cannot create node %s", file_entry->name);
}
goto cleanup;
}
break;
default:
*err = -1;
perror_msg("Don't know how to handle %s", full_name);
}
/* 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);
}
chown(full_name, file_entry->uid, file_entry->gid);
chmod(full_name, file_entry->mode);
}
} 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", file_entry->name);
}
cleanup:
free(full_name);
if ( full_link_name )
free(full_link_name);
return buffer;
}
char *
deb_extract(const char *package_filename, FILE *out_stream,
const int extract_function, const char *prefix,
const char *filename, int *err)
{
FILE *deb_stream = NULL;
file_header_t *ar_header = NULL;
const char **file_list = NULL;
char *output_buffer = NULL;
char *ared_file = NULL;
char ar_magic[8];
int gz_err;
*err = 0;
if (filename != NULL) {
file_list = xmalloc(sizeof(char *) * 2);
file_list[0] = filename;
file_list[1] = NULL;
}
if (extract_function & extract_control_tar_gz) {
ared_file = "control.tar.gz";
}
else if (extract_function & extract_data_tar_gz) {
ared_file = "data.tar.gz";
} else {
error_msg( "Internal error: extract_function=%x\n",
extract_function);
*err = -1;
goto cleanup;
}
/* open the debian package to be worked on */
deb_stream = wfopen(package_filename, "r");
if (deb_stream == NULL) {
*err = -1;
goto cleanup;
}
/* set the buffer size */
setvbuf(deb_stream, NULL, _IOFBF, 0x8000);
/* check ar magic */
fread(ar_magic, 1, 8, deb_stream);
if (strncmp(ar_magic,"!<arch>",7) == 0) {
archive_offset = 8;
while ((ar_header = get_header_ar(deb_stream)) != NULL) {
if (strcmp(ared_file, ar_header->name) == 0) {
int gunzip_pid = 0;
FILE *uncompressed_stream;
/* open a stream of decompressed data */
uncompressed_stream = gz_open(deb_stream, &gunzip_pid);
if (uncompressed_stream == NULL) {
*err = -1;
goto cleanup;
}
archive_offset = 0;
output_buffer = unarchive(uncompressed_stream,
out_stream, get_header_tar,
free_header_tar,
extract_function, prefix,
file_list, err);
fclose(uncompressed_stream);
gz_err = gz_close(gunzip_pid);
if (gz_err)
*err = -1;
free_header_ar(ar_header);
break;
}
if (fseek(deb_stream, ar_header->size, SEEK_CUR) == -1) {
perror_msg("Couldn't fseek into %s", package_filename);
*err = -1;
free_header_ar(ar_header);
goto cleanup;
}
free_header_ar(ar_header);
}
goto cleanup;
} else if (strncmp(ar_magic, "\037\213", 2) == 0) {
/* it's a gz file, let's assume it's an opkg */
int unzipped_opkg_pid;
FILE *unzipped_opkg_stream;
file_header_t *tar_header;
archive_offset = 0;
if (fseek(deb_stream, 0, SEEK_SET) == -1) {
perror_msg( "Couldn't fseek into %s", package_filename);
*err = -1;
goto cleanup;
}
unzipped_opkg_stream = gz_open(deb_stream, &unzipped_opkg_pid);
if (unzipped_opkg_stream == NULL) {
*err = -1;
goto cleanup;
}
/* walk through outer tar file to find ared_file */
while ((tar_header = get_header_tar(unzipped_opkg_stream)) != NULL) {
int name_offset = 0;
if (strncmp(tar_header->name, "./", 2) == 0)
name_offset = 2;
if (strcmp(ared_file, tar_header->name+name_offset) == 0) {
int gunzip_pid = 0;
FILE *uncompressed_stream;
/* open a stream of decompressed data */
uncompressed_stream = gz_open(unzipped_opkg_stream, &gunzip_pid);
if (uncompressed_stream == NULL) {
*err = -1;
goto cleanup;
}
archive_offset = 0;
output_buffer = unarchive(uncompressed_stream,
out_stream,
get_header_tar,
free_header_tar,
extract_function,
prefix,
file_list,
err);
free_header_tar(tar_header);
fclose(uncompressed_stream);
gz_err = gz_close(gunzip_pid);
if (gz_err)
*err = -1;
break;
}
seek_sub_file(unzipped_opkg_stream, tar_header->size);
free_header_tar(tar_header);
}
fclose(unzipped_opkg_stream);
gz_err = gz_close(unzipped_opkg_pid);
if (gz_err)
*err = -1;
goto cleanup;
} else {
*err = -1;
error_msg("%s: invalid magic", package_filename);
}
cleanup:
if (deb_stream)
fclose(deb_stream);
if (file_list)
free(file_list);
return output_buffer;
}
static file_header_t *
get_header_tar(FILE *tar_stream)
{
union {
unsigned char raw[512];
struct {
char name[100]; /* 0-99 */
char mode[8]; /* 100-107 */
char uid[8]; /* 108-115 */
char gid[8]; /* 116-123 */
char size[12]; /* 124-135 */
char mtime[12]; /* 136-147 */
char chksum[8]; /* 148-155 */
char typeflag; /* 156-156 */
char linkname[100]; /* 157-256 */
char magic[6]; /* 257-262 */
char version[2]; /* 263-264 */
char uname[32]; /* 265-296 */
char gname[32]; /* 297-328 */
char devmajor[8]; /* 329-336 */
char devminor[8]; /* 337-344 */
char prefix[155]; /* 345-499 */
char padding[12]; /* 500-512 */
} formated;
} tar;
file_header_t *tar_entry = NULL;
long i;
long sum = 0;
if (archive_offset % 512 != 0) {
seek_sub_file(tar_stream, 512 - (archive_offset % 512));
}
if (fread(tar.raw, 1, 512, tar_stream) != 512) {
/* Unfortunately its common for tar files to have all sorts of
* trailing garbage, fail silently */
// error_msg("Couldnt read header");
return(NULL);
}
archive_offset += 512;
/* Check header has valid magic, unfortunately some tar files
* have empty (0'ed) tar entries at the end, which will
* cause this to fail, so fail silently for now
*/
if (strncmp(tar.formated.magic, "ustar", 5) != 0) {
#ifdef CONFIG_FEATURE_TAR_OLDGNU_COMPATABILITY
if (strncmp(tar.formated.magic, "\0\0\0\0\0", 5) != 0)
#endif
return(NULL);
}
/* Do checksum on headers */
for (i = 0; i < 148 ; i++) {
sum += tar.raw[i];
}
sum += ' ' * 8;
for (i = 156; i < 512 ; i++) {
sum += tar.raw[i];
}
if (sum != strtol(tar.formated.chksum, NULL, 8)) {
if ( strtol(tar.formated.chksum,NULL,8) != 0 )
error_msg("Invalid tar header checksum");
return(NULL);
}
/* convert to type'ed variables */
tar_entry = xcalloc(1, sizeof(file_header_t));
// tar_entry->name = xstrdup(tar.formated.name);
/*
parse_mode(tar.formated.mode, &tar_entry->mode);
*/
tar_entry->mode = 07777 & strtol(tar.formated.mode, NULL, 8);
tar_entry->uid = strtol(tar.formated.uid, NULL, 8);
tar_entry->gid = strtol(tar.formated.gid, NULL, 8);
tar_entry->size = strtol(tar.formated.size, NULL, 8);
tar_entry->mtime = strtol(tar.formated.mtime, NULL, 8);
tar_entry->device = (strtol(tar.formated.devmajor, NULL, 8) << 8) +
strtol(tar.formated.devminor, NULL, 8);
/* Fix mode, used by the old format */
switch (tar.formated.typeflag) {
/* hard links are detected as regular files with 0 size and a link name */
case '1':
tar_entry->mode |= S_IFREG ;
break;
case 0:
case '0':
# ifdef CONFIG_FEATURE_TAR_OLDGNU_COMPATABILITY
if (last_char_is(tar_entry->name, '/')) {
tar_entry->mode |= S_IFDIR;
} else
# endif
tar_entry->mode |= S_IFREG;
break;
case '2':
tar_entry->mode |= S_IFLNK;
break;
case '3':
tar_entry->mode |= S_IFCHR;
break;
case '4':
tar_entry->mode |= S_IFBLK;
break;
case '5':
tar_entry->mode |= S_IFDIR;
break;
case '6':
tar_entry->mode |= S_IFIFO;
break;
# ifdef CONFIG_FEATURE_TAR_GNU_EXTENSIONS
case 'L': {
longname = xmalloc(tar_entry->size + 1);
if(fread(longname, tar_entry->size, 1, tar_stream) != 1)
return NULL;
longname[tar_entry->size] = '\0';
archive_offset += tar_entry->size;
return(get_header_tar(tar_stream));
}
case 'K': {
linkname = xmalloc(tar_entry->size + 1);
if(fread(linkname, tar_entry->size, 1, tar_stream) != 1)
return NULL;
linkname[tar_entry->size] = '\0';
archive_offset += tar_entry->size;
return(get_header_tar(tar_stream));
}
case 'D':
case 'M':
case 'N':
case 'S':
case 'V':
perror_msg("Ignoring GNU extension type %c", tar.formated.typeflag);
# endif
default:
perror_msg("Unknown typeflag: 0x%x", tar.formated.typeflag);
break;
}
#ifdef CONFIG_FEATURE_TAR_GNU_EXTENSIONS
if (longname) {
tar_entry->name = longname;
longname = NULL;
} else
#endif
{
tar_entry->name = xstrndup(tar.formated.name, 100);
if (tar.formated.prefix[0]) {
char *temp = tar_entry->name;
char *prefixTemp = xstrndup(tar.formated.prefix, 155);
tar_entry->name = concat_path_file(prefixTemp, temp);
free(temp);
free(prefixTemp);
}
}
if (linkname) {
tar_entry->link_name = linkname;
linkname = NULL;
} else
{
tar_entry->link_name = *tar.formated.linkname != '\0' ?
xstrndup(tar.formated.linkname, 100) : NULL;
}
return(tar_entry);
}
static file_header_t *
get_header_ar(FILE *src_stream)
{
file_header_t *typed;
union {
char raw[60];
struct {
char name[16];
char date[12];
char uid[6];
char gid[6];
char mode[8];
char size[10];
char magic[2];
} formated;
} ar;
static char *ar_long_names;
if (fread(ar.raw, 1, 60, src_stream) != 60) {
return(NULL);
}
archive_offset += 60;
/* align the headers based on the header magic */
if ((ar.formated.magic[0] != '`') || (ar.formated.magic[1] != '\n')) {
/* some version of ar, have an extra '\n' after each data entry,
* this puts the next header out by 1 */
if (ar.formated.magic[1] != '`') {
error_msg("Invalid magic");
return(NULL);
}
/* read the next char out of what would be the data section,
* if its a '\n' then it is a valid header offset by 1*/
archive_offset++;
if (fgetc(src_stream) != '\n') {
error_msg("Invalid magic");
return(NULL);
}
/* fix up the header, we started reading 1 byte too early */
/* raw_header[60] wont be '\n' as it should, but it doesnt matter */
memmove(ar.raw, &ar.raw[1], 59);
}
typed = (file_header_t *) xcalloc(1, sizeof(file_header_t));
typed->size = (size_t) atoi(ar.formated.size);
/* long filenames have '/' as the first character */
if (ar.formated.name[0] == '/') {
if (ar.formated.name[1] == '/') {
/* If the second char is a '/' then this entries data section
* stores long filename for multiple entries, they are stored
* in static variable long_names for use in future entries */
ar_long_names = (char *) xrealloc(ar_long_names, typed->size);
fread(ar_long_names, 1, typed->size, src_stream);
archive_offset += typed->size;
/* This ar entries data section only contained filenames for other records
* they are stored in the static ar_long_names for future reference */
return (get_header_ar(src_stream)); /* Return next header */
} else if (ar.formated.name[1] == ' ') {
/* This is the index of symbols in the file for compilers */
seek_sub_file(src_stream, typed->size);
return (get_header_ar(src_stream)); /* Return next header */
} else {
/* The number after the '/' indicates the offset in the ar data section
(saved in variable long_name) that conatains the real filename */
if (!ar_long_names) {
error_msg("Cannot resolve long file name");
return (NULL);
}
typed->name = xstrdup(ar_long_names + atoi(&ar.formated.name[1]));
}
} else {
/* short filenames */
typed->name = xcalloc(1, 16);
strncpy(typed->name, ar.formated.name, 16);
}
typed->name[strcspn(typed->name, " /")]='\0';
/* convert the rest of the now valid char header to its typed struct */
parse_mode(ar.formated.mode, &typed->mode);
typed->mtime = atoi(ar.formated.date);
typed->uid = atoi(ar.formated.uid);
typed->gid = atoi(ar.formated.gid);
return(typed);
}
static char *
unarchive(FILE *src_stream, FILE *out_stream,
file_header_t *(*get_headers)(FILE *),
void (*free_headers)(file_header_t *),
const int extract_function,
const char *prefix,
const char **extract_names,
int *err)
{
file_header_t *file_entry;
int extract_flag;
int i;
char *buffer = NULL;
*err = 0;
archive_offset = 0;
while ((file_entry = get_headers(src_stream)) != NULL) {
extract_flag = TRUE;
if (extract_names != NULL) {
int found_flag = FALSE;
char *p = file_entry->name;
if (p[0] == '.' && p[1] == '/')
p += 2;
for(i = 0; extract_names[i] != 0; i++) {
if (strcmp(extract_names[i], p) == 0) {
found_flag = TRUE;
break;
}
}
if (extract_function & extract_exclude_list) {
if (found_flag == TRUE) {
extract_flag = FALSE;
}
} else {
/* If its not found in the include list dont extract it */
if (found_flag == FALSE) {
extract_flag = FALSE;
}
}
}
if (extract_flag == TRUE) {
buffer = extract_archive(src_stream, out_stream,
file_entry, extract_function,
prefix, err);
*err = 0; /* XXX: ignore extraction errors */
if (*err) {
free_headers(file_entry);
break;
}
} else {
/* seek past the data entry */
seek_sub_file(src_stream, file_entry->size);
}
free_headers(file_entry);
}
return buffer;
}
