/* Verify the tar checksum. */
static int
verify_checksum(const char *p)
{
int n, u = 0;
for (n = 0; n < 512; ++n) {
if (n < 148 || n > 155)
/* Standard tar checksum adds unsigned bytes. */
u += ((unsigned char *)p)[n];
else
u += 0x20;
}
return (u == parseoct(p + 148, 8));
}
/* Extract a tar archive. */
static void
untar(FILE *a, const char *path)
{
char buff[512];
FILE *f = NULL;
size_t bytes_read;
int filesize;
char *fullPath = NULL;
printf("Extracting from %s\n", path);
for (;;) {
bytes_read = fread(buff, 1, 512, a);
if (bytes_read < 512) {
fprintf(stderr,
"Short read on %s: expected 512, got %d\n",
path, (int)bytes_read);
return;
}
if (is_end_of_archive(buff)) {
printf("End of %s\n", path);
return;
}
if (!verify_checksum(buff)) {
fprintf(stderr, "Checksum failure\n");
return;
}
filesize = parseoct(buff + 124, 12);
switch (buff[156]) {
case '1':
printf(" Ignoring hardlink %s\n", buff);
break;
case '2':
printf(" Ignoring symlink %s\n", buff);
break;
case '3':
printf(" Ignoring character device %s\n", buff);
break;
case '4':
printf(" Ignoring block device %s\n", buff);
break;
case '5':
printf(" Extracting dir %s\n", buff);
fullPath = string_concat(3, basePath, "/", buff);
create_dir(fullPath, parseoct(buff + 100, 8));
free(fullPath);
filesize = 0;
break;
case '6':
printf(" Ignoring FIFO %s\n", buff);
break;
default:
printf(" Extracting file %s\n", buff);
fullPath = string_concat(3, basePath, "/", buff);
f = create_file(fullPath, parseoct(buff + 100, 8));
free(fullPath);
break;
}
while (filesize > 0) {
bytes_read = fread(buff, 1, 512, a);
if (bytes_read < 512) {
fprintf(stderr,
"Short read on %s: Expected 512, got %d\n",
path, (int)bytes_read);
return;
}
if (filesize < 512)
bytes_read = filesize;
if (f != NULL) {
if (fwrite(buff, 1, bytes_read, f)
!= bytes_read)
{
fprintf(stderr, "Failed write\n");
fclose(f);
f = NULL;
}
}
filesize -= bytes_read;
}
if (f != NULL) {
fclose(f);
f = NULL;
}
}
}
/* Extract a tar archive. */
void
untar(FILE *a, const char *path)
{
#ifdef ASSET_VERBOSE
printf("==== storm untar v1.1.2 ====\n");
clock_t start = clock() / (CLOCKS_PER_SEC / 1000);
printf("unpacking archive..\n");
#endif
char buff[512];
FILE *f = NULL;
size_t bytes_read;
int filesize;
for (;;) {
bytes_read = fread(buff, 1, 512, a);
if (bytes_read < 512) {
#ifdef ASSET_VERBOSE
fprintf(stderr,
"Short read: expected 512, got %d\n", (int)bytes_read);
#endif
return;
}
if (is_end_of_archive(buff)) {
#ifdef ASSET_VERBOSE
printf("===== completed in %lums ======\n", (clock() / (CLOCKS_PER_SEC / 1000)) - start);
#endif
return;
}
if (!verify_checksum(buff)) {
#ifdef ASSET_VERBOSE
fprintf(stderr, "Checksum failure\n");
#endif
return;
}
filesize = parseoct(buff + 124, 12);
char *filepath = malloc(sizeof(buff) + sizeof(path) + sizeof("/"));
if (filepath) {
strcpy(filepath, path);
strcat(filepath, "/");
strcat(filepath, buff);
}
switch (buff[156]) {
case '1':
// printf("> Ignoring hardlink %s\n", buff);
break;
case '2':
// printf("> Ignoring symlink %s\n", buff);
break;
case '3':
// printf("> Ignoring character device %s\n", buff);
break;
case '4':
// printf("> Ignoring block device %s\n", buff);
break;
case '5':
create_dir(filepath, parseoct(buff + 100, 8));
filesize = 0;
break;
case '6':
// printf("> Ignoring FIFO %s\n", buff);
break;
default:
#ifdef ASSET_VERBOSE
printf("> %s\n", buff);
#endif
f = create_file(filepath, parseoct(buff + 100, 8));
break;
}
while (filesize > 0) {
bytes_read = fread(buff, 1, 512, a);
if (bytes_read < 512) {
#ifdef ASSET_VERBOSE
fprintf(stderr,
"Short read on %s: Expected 512, got %d\n",
path, (int)bytes_read);
#endif
if (filepath != NULL) free(filepath); // Clear up any memory left for the file path
return;
}
if (filesize < 512)
bytes_read = filesize;
if (f != NULL) {
if (fwrite(buff, 1, bytes_read, f)
!= bytes_read)
{
#ifdef ASSET_VERBOSE
fprintf(stderr, "Failed write\n");
fclose(f);
f = NULL;
#endif
}
}
filesize -= bytes_read;
}
if (f != NULL) {
fclose(f);
f = NULL;
}
free(filepath);
}
}
