busybox/archival/unzip.c

409 lines
11 KiB
C

/* vi: set sw=4 ts=4: */
/*
* Mini unzip implementation for busybox
*
* Copyright (C) 2004 by Ed Clark
*
* Loosely based on original busybox unzip applet by Laurence Anderson.
* All options and features should work in this version.
*
* Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
*/
/* For reference see
* http://www.pkware.com/company/standards/appnote/
* http://www.info-zip.org/pub/infozip/doc/appnote-iz-latest.zip
*/
/* TODO
* Endian issues
* Zip64 + other methods
* Improve handling of zip format, ie.
* - deferred CRC, comp. & uncomp. lengths (zip header flags bit 3)
* - unix file permissions, etc.
* - central directory
*/
#include "libbb.h"
#include "unarchive.h"
enum {
#if BB_BIG_ENDIAN
ZIP_FILEHEADER_MAGIC = 0x504b0304,
ZIP_CDS_MAGIC = 0x504b0102,
ZIP_CDS_END_MAGIC = 0x504b0506,
ZIP_DD_MAGIC = 0x504b0708,
#else
ZIP_FILEHEADER_MAGIC = 0x04034b50,
ZIP_CDS_MAGIC = 0x02014b50,
ZIP_CDS_END_MAGIC = 0x06054b50,
ZIP_DD_MAGIC = 0x08074b50,
#endif
};
#define ZIP_HEADER_LEN 26
typedef union {
uint8_t raw[ZIP_HEADER_LEN];
struct {
uint16_t version; /* 0-1 */
uint16_t flags; /* 2-3 */
uint16_t method; /* 4-5 */
uint16_t modtime; /* 6-7 */
uint16_t moddate; /* 8-9 */
uint32_t crc32 ATTRIBUTE_PACKED; /* 10-13 */
uint32_t cmpsize ATTRIBUTE_PACKED; /* 14-17 */
uint32_t ucmpsize ATTRIBUTE_PACKED; /* 18-21 */
uint16_t filename_len; /* 22-23 */
uint16_t extra_len; /* 24-25 */
} formatted ATTRIBUTE_PACKED;
} zip_header_t; /* ATTRIBUTE_PACKED - gcc 4.2.1 doesn't like it (spews warning) */
/* Check the offset of the last element, not the length. This leniency
* allows for poor packing, whereby the overall struct may be too long,
* even though the elements are all in the right place.
*/
struct BUG_zip_header_must_be_26_bytes {
char BUG_zip_header_must_be_26_bytes[
offsetof(zip_header_t, formatted.extra_len) + 2 ==
ZIP_HEADER_LEN ? 1 : -1];
};
#define FIX_ENDIANNESS(zip_header) do { \
(zip_header).formatted.version = SWAP_LE16((zip_header).formatted.version ); \
(zip_header).formatted.flags = SWAP_LE16((zip_header).formatted.flags ); \
(zip_header).formatted.method = SWAP_LE16((zip_header).formatted.method ); \
(zip_header).formatted.modtime = SWAP_LE16((zip_header).formatted.modtime ); \
(zip_header).formatted.moddate = SWAP_LE16((zip_header).formatted.moddate ); \
(zip_header).formatted.crc32 = SWAP_LE32((zip_header).formatted.crc32 ); \
(zip_header).formatted.cmpsize = SWAP_LE32((zip_header).formatted.cmpsize ); \
(zip_header).formatted.ucmpsize = SWAP_LE32((zip_header).formatted.ucmpsize ); \
(zip_header).formatted.filename_len = SWAP_LE16((zip_header).formatted.filename_len); \
(zip_header).formatted.extra_len = SWAP_LE16((zip_header).formatted.extra_len ); \
} while (0)
static void unzip_skip(int fd, off_t skip)
{
bb_copyfd_exact_size(fd, -1, skip);
}
static void unzip_create_leading_dirs(const char *fn)
{
/* Create all leading directories */
char *name = xstrdup(fn);
if (bb_make_directory(dirname(name), 0777, FILEUTILS_RECUR)) {
bb_error_msg_and_die("exiting"); /* bb_make_directory is noisy */
}
free(name);
}
static void unzip_extract(zip_header_t *zip_header, int src_fd, int dst_fd)
{
if (zip_header->formatted.method == 0) {
/* Method 0 - stored (not compressed) */
off_t size = zip_header->formatted.ucmpsize;
if (size)
bb_copyfd_exact_size(src_fd, dst_fd, size);
} else {
/* Method 8 - inflate */
inflate_unzip_result res;
if (inflate_unzip(&res, zip_header->formatted.cmpsize, src_fd, dst_fd) < 0)
bb_error_msg_and_die("inflate error");
/* Validate decompression - crc */
if (zip_header->formatted.crc32 != (res.crc ^ 0xffffffffL)) {
bb_error_msg_and_die("crc error");
}
/* Validate decompression - size */
if (zip_header->formatted.ucmpsize != res.bytes_out) {
/* Don't die. Who knows, maybe len calculation
* was botched somewhere. After all, crc matched! */
bb_error_msg("bad length");
}
}
}
int unzip_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int unzip_main(int argc, char **argv)
{
enum { O_PROMPT, O_NEVER, O_ALWAYS };
zip_header_t zip_header;
smallint verbose = 1;
smallint listing = 0;
smallint overwrite = O_PROMPT;
unsigned total_size;
unsigned total_entries;
int src_fd = -1;
int dst_fd = -1;
char *src_fn = NULL;
char *dst_fn = NULL;
llist_t *zaccept = NULL;
llist_t *zreject = NULL;
char *base_dir = NULL;
int i, opt;
int opt_range = 0;
char key_buf[80];
struct stat stat_buf;
/* '-' makes getopt return 1 for non-options */
while ((opt = getopt(argc, argv, "-d:lnopqx")) != -1) {
switch (opt_range) {
case 0: /* Options */
switch (opt) {
case 'l': /* List */
listing = 1;
break;
case 'n': /* Never overwrite existing files */
overwrite = O_NEVER;
break;
case 'o': /* Always overwrite existing files */
overwrite = O_ALWAYS;
break;
case 'p': /* Extract files to stdout and fall through to set verbosity */
dst_fd = STDOUT_FILENO;
case 'q': /* Be quiet */
verbose = 0;
break;
case 1: /* The zip file */
/* +5: space for ".zip" and NUL */
src_fn = xmalloc(strlen(optarg) + 5);
strcpy(src_fn, optarg);
opt_range++;
break;
default:
bb_show_usage();
}
break;
case 1: /* Include files */
if (opt == 1) {
llist_add_to(&zaccept, optarg);
break;
}
if (opt == 'd') {
base_dir = optarg;
opt_range += 2;
break;
}
if (opt == 'x') {
opt_range++;
break;
}
bb_show_usage();
case 2 : /* Exclude files */
if (opt == 1) {
llist_add_to(&zreject, optarg);
break;
}
if (opt == 'd') { /* Extract to base directory */
base_dir = optarg;
opt_range++;
break;
}
/* fall through */
default:
bb_show_usage();
}
}
if (src_fn == NULL) {
bb_show_usage();
}
/* Open input file */
if (LONE_DASH(src_fn)) {
src_fd = STDIN_FILENO;
/* Cannot use prompt mode since zip data is arriving on STDIN */
if (overwrite == O_PROMPT)
overwrite = O_NEVER;
} else {
static const char extn[][5] = {"", ".zip", ".ZIP"};
int orig_src_fn_len = strlen(src_fn);
for (i = 0; (i < 3) && (src_fd == -1); i++) {
strcpy(src_fn + orig_src_fn_len, extn[i]);
src_fd = open(src_fn, O_RDONLY);
}
if (src_fd == -1) {
src_fn[orig_src_fn_len] = '\0';
bb_error_msg_and_die("can't open %s, %s.zip, %s.ZIP", src_fn, src_fn, src_fn);
}
}
/* Change dir if necessary */
if (base_dir)
xchdir(base_dir);
if (verbose) {
printf("Archive: %s\n", src_fn);
if (listing){
puts(" Length Date Time Name\n"
" -------- ---- ---- ----");
}
}
total_size = 0;
total_entries = 0;
while (1) {
uint32_t magic;
/* Check magic number */
xread(src_fd, &magic, 4);
if (magic == ZIP_CDS_MAGIC)
break;
if (magic != ZIP_FILEHEADER_MAGIC)
bb_error_msg_and_die("invalid zip magic %08X", magic);
/* Read the file header */
xread(src_fd, zip_header.raw, ZIP_HEADER_LEN);
FIX_ENDIANNESS(zip_header);
if ((zip_header.formatted.method != 0) && (zip_header.formatted.method != 8)) {
bb_error_msg_and_die("unsupported method %d", zip_header.formatted.method);
}
/* Read filename */
free(dst_fn);
dst_fn = xzalloc(zip_header.formatted.filename_len + 1);
xread(src_fd, dst_fn, zip_header.formatted.filename_len);
/* Skip extra header bytes */
unzip_skip(src_fd, zip_header.formatted.extra_len);
/* Filter zip entries */
if (find_list_entry(zreject, dst_fn)
|| (zaccept && !find_list_entry(zaccept, dst_fn))
) { /* Skip entry */
i = 'n';
} else { /* Extract entry */
if (listing) { /* List entry */
if (verbose) {
unsigned dostime = zip_header.formatted.modtime | (zip_header.formatted.moddate << 16);
printf("%9u %02u-%02u-%02u %02u:%02u %s\n",
zip_header.formatted.ucmpsize,
(dostime & 0x01e00000) >> 21,
(dostime & 0x001f0000) >> 16,
(((dostime & 0xfe000000) >> 25) + 1980) % 100,
(dostime & 0x0000f800) >> 11,
(dostime & 0x000007e0) >> 5,
dst_fn);
total_size += zip_header.formatted.ucmpsize;
total_entries++;
} else {
/* short listing -- filenames only */
puts(dst_fn);
}
i = 'n';
} else if (dst_fd == STDOUT_FILENO) { /* Extracting to STDOUT */
i = -1;
} else if (last_char_is(dst_fn, '/')) { /* Extract directory */
if (stat(dst_fn, &stat_buf) == -1) {
if (errno != ENOENT) {
bb_perror_msg_and_die("cannot stat '%s'",dst_fn);
}
if (verbose) {
printf(" creating: %s\n", dst_fn);
}
unzip_create_leading_dirs(dst_fn);
if (bb_make_directory(dst_fn, 0777, 0)) {
bb_error_msg_and_die("exiting");
}
} else {
if (!S_ISDIR(stat_buf.st_mode)) {
bb_error_msg_and_die("'%s' exists but is not directory", dst_fn);
}
}
i = 'n';
} else { /* Extract file */
_check_file:
if (stat(dst_fn, &stat_buf) == -1) { /* File does not exist */
if (errno != ENOENT) {
bb_perror_msg_and_die("cannot stat '%s'",dst_fn);
}
i = 'y';
} else { /* File already exists */
if (overwrite == O_NEVER) {
i = 'n';
} else if (S_ISREG(stat_buf.st_mode)) { /* File is regular file */
if (overwrite == O_ALWAYS) {
i = 'y';
} else {
printf("replace %s? [y]es, [n]o, [A]ll, [N]one, [r]ename: ", dst_fn);
if (!fgets(key_buf, sizeof(key_buf), stdin)) {
bb_perror_msg_and_die("cannot read input");
}
i = key_buf[0];
}
} else { /* File is not regular file */
bb_error_msg_and_die("'%s' exists but is not regular file",dst_fn);
}
}
}
}
switch (i) {
case 'A':
overwrite = O_ALWAYS;
case 'y': /* Open file and fall into unzip */
unzip_create_leading_dirs(dst_fn);
dst_fd = xopen(dst_fn, O_WRONLY | O_CREAT | O_TRUNC);
case -1: /* Unzip */
if (verbose) {
printf(" inflating: %s\n", dst_fn);
}
unzip_extract(&zip_header, src_fd, dst_fd);
if (dst_fd != STDOUT_FILENO) {
/* closing STDOUT is potentially bad for future business */
close(dst_fd);
}
break;
case 'N':
overwrite = O_NEVER;
case 'n':
/* Skip entry data */
unzip_skip(src_fd, zip_header.formatted.cmpsize);
break;
case 'r':
/* Prompt for new name */
printf("new name: ");
if (!fgets(key_buf, sizeof(key_buf), stdin)) {
bb_perror_msg_and_die("cannot read input");
}
free(dst_fn);
dst_fn = xstrdup(key_buf);
chomp(dst_fn);
goto _check_file;
default:
printf("error: invalid response [%c]\n",(char)i);
goto _check_file;
}
/* Data descriptor section */
if (zip_header.formatted.flags & 4) {
/* skip over duplicate crc, compressed size and uncompressed size */
unzip_skip(src_fd, 12);
}
}
if (listing && verbose) {
printf(" -------- -------\n"
"%9d %d files\n",
total_size, total_entries);
}
return 0;
}