busybox/archival/unzip.c
Rob Landley 534374755d Cleaup read() and write() variants, plus a couple of new functions like
xlseek and fdlength() for the new mkswap.
2006-07-16 08:14:35 +00:00

392 lines
10 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 <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include "unarchive.h"
#include "busybox.h"
#define ZIP_FILEHEADER_MAGIC SWAP_LE32(0x04034b50)
#define ZIP_CDS_MAGIC SWAP_LE32(0x02014b50)
#define ZIP_CDS_END_MAGIC SWAP_LE32(0x06054b50)
#define ZIP_DD_MAGIC SWAP_LE32(0x08074b50)
extern unsigned int gunzip_crc;
extern unsigned int gunzip_bytes_out;
typedef union {
unsigned char raw[26];
struct {
unsigned short version; /* 0-1 */
unsigned short flags; /* 2-3 */
unsigned short method; /* 4-5 */
unsigned short modtime; /* 6-7 */
unsigned short moddate; /* 8-9 */
unsigned int crc32 ATTRIBUTE_PACKED; /* 10-13 */
unsigned int cmpsize ATTRIBUTE_PACKED; /* 14-17 */
unsigned int ucmpsize ATTRIBUTE_PACKED; /* 18-21 */
unsigned short filename_len; /* 22-23 */
unsigned short extra_len; /* 24-25 */
} formated ATTRIBUTE_PACKED;
} zip_header_t;
static void unzip_skip(int fd, off_t skip)
{
if (lseek(fd, skip, SEEK_CUR) == (off_t)-1) {
if ((errno != ESPIPE) || (bb_copyfd_size(fd, -1, skip) != skip)) {
bb_error_msg_and_die("Seek failure");
}
}
}
static void unzip_create_leading_dirs(char *fn)
{
/* Create all leading directories */
char *name = bb_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 int unzip_extract(zip_header_t *zip_header, int src_fd, int dst_fd)
{
if (zip_header->formated.method == 0) {
/* Method 0 - stored (not compressed) */
int size = zip_header->formated.ucmpsize;
if (size && (bb_copyfd_size(src_fd, dst_fd, size) != size)) {
bb_error_msg_and_die("Cannot complete extraction");
}
} else {
/* Method 8 - inflate */
inflate_init(zip_header->formated.cmpsize);
inflate_unzip(src_fd, dst_fd);
inflate_cleanup();
/* Validate decompression - crc */
if (zip_header->formated.crc32 != (gunzip_crc ^ 0xffffffffL)) {
bb_error_msg("Invalid compressed data--crc error");
return 1;
}
/* Validate decompression - size */
if (zip_header->formated.ucmpsize != gunzip_bytes_out) {
bb_error_msg("Invalid compressed data--length error");
return 1;
}
}
return 0;
}
int unzip_main(int argc, char **argv)
{
zip_header_t zip_header;
enum {v_silent, v_normal, v_list} verbosity = v_normal;
enum {o_prompt, o_never, o_always} overwrite = o_prompt;
unsigned int total_size = 0;
unsigned int total_entries = 0;
int src_fd = -1, dst_fd = -1;
char *src_fn = NULL, *dst_fn = NULL;
llist_t *zaccept = NULL;
llist_t *zreject = NULL;
char *base_dir = NULL;
int failed, i, opt, opt_range = 0, list_header_done = 0;
char key_buf[512];
struct stat stat_buf;
while((opt = getopt(argc, argv, "-d:lnopqx")) != -1) {
switch(opt_range) {
case 0: /* Options */
switch(opt) {
case 'l': /* List */
verbosity = v_list;
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 */
verbosity = (verbosity == v_normal) ? v_silent : verbosity;
break;
case 1 : /* The zip file */
src_fn = bb_xstrndup(optarg, strlen(optarg)+4);
opt_range++;
break;
default:
bb_show_usage();
}
break;
case 1: /* Include files */
if (opt == 1) {
llist_add_to(&zaccept, optarg);
} else if (opt == 'd') {
base_dir = optarg;
opt_range += 2;
} else if (opt == 'x') {
opt_range++;
} else {
bb_show_usage();
}
break;
case 2 : /* Exclude files */
if (opt == 1) {
llist_add_to(&zreject, optarg);
} else if (opt == 'd') { /* Extract to base directory */
base_dir = optarg;
opt_range++;
} else {
bb_show_usage();
}
break;
default:
bb_show_usage();
}
}
if (src_fn == NULL) {
bb_show_usage();
}
/* Open input file */
if (strcmp("-", src_fn) == 0) {
src_fd = STDIN_FILENO;
/* Cannot use prompt mode since zip data is arriving on STDIN */
overwrite = (overwrite == o_prompt) ? o_never : overwrite;
} else {
static const char *const extn[] = {"", ".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("Cannot open %s, %s.zip, %s.ZIP", src_fn, src_fn, src_fn);
}
}
/* Change dir if necessary */
if (base_dir)
bb_xchdir(base_dir);
if (verbosity != v_silent)
printf("Archive: %s\n", src_fn);
failed = 0;
while (1) {
unsigned int magic;
/* Check magic number */
xread(src_fd, &magic, 4);
if (magic == ZIP_CDS_MAGIC) {
break;
} else 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, 26);
zip_header.formated.version = SWAP_LE32(zip_header.formated.version);
zip_header.formated.flags = SWAP_LE32(zip_header.formated.flags);
zip_header.formated.method = SWAP_LE32(zip_header.formated.method);
zip_header.formated.modtime = SWAP_LE32(zip_header.formated.modtime);
zip_header.formated.moddate = SWAP_LE32(zip_header.formated.moddate);
zip_header.formated.crc32 = SWAP_LE32(zip_header.formated.crc32);
zip_header.formated.cmpsize = SWAP_LE32(zip_header.formated.cmpsize);
zip_header.formated.ucmpsize = SWAP_LE32(zip_header.formated.ucmpsize);
zip_header.formated.filename_len = SWAP_LE32(zip_header.formated.filename_len);
zip_header.formated.extra_len = SWAP_LE32(zip_header.formated.extra_len);
if ((zip_header.formated.method != 0) && (zip_header.formated.method != 8)) {
bb_error_msg_and_die("Unsupported compression method %d", zip_header.formated.method);
}
/* Read filename */
free(dst_fn);
dst_fn = xzalloc(zip_header.formated.filename_len + 1);
xread(src_fd, dst_fn, zip_header.formated.filename_len);
/* Skip extra header bytes */
unzip_skip(src_fd, zip_header.formated.extra_len);
if ((verbosity == v_list) && !list_header_done){
printf(" Length Date Time Name\n"
" -------- ---- ---- ----\n");
list_header_done = 1;
}
/* Filter zip entries */
if (find_list_entry(zreject, dst_fn) ||
(zaccept && !find_list_entry(zaccept, dst_fn))) { /* Skip entry */
i = 'n';
} else { /* Extract entry */
total_size += zip_header.formated.ucmpsize;
if (verbosity == v_list) { /* List entry */
unsigned int dostime = zip_header.formated.modtime | (zip_header.formated.moddate << 16);
printf("%9u %02u-%02u-%02u %02u:%02u %s\n",
zip_header.formated.ucmpsize,
(dostime & 0x01e00000) >> 21,
(dostime & 0x001f0000) >> 16,
(((dostime & 0xfe000000) >> 25) + 1980) % 100,
(dostime & 0x0000f800) >> 11,
(dostime & 0x000007e0) >> 5,
dst_fn);
total_entries++;
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 (verbosity == v_normal) {
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, 512, 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 = bb_xopen(dst_fn, O_WRONLY | O_CREAT);
case -1: /* Unzip */
if (verbosity == v_normal) {
printf(" inflating: %s\n", dst_fn);
}
if (unzip_extract(&zip_header, src_fd, dst_fd)) {
failed = 1;
}
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.formated.cmpsize);
break;
case 'r':
/* Prompt for new name */
printf("new name: ");
if (!fgets(key_buf, 512, stdin)) {
bb_perror_msg_and_die("Cannot read input");
}
free(dst_fn);
dst_fn = bb_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.formated.flags & 4) {
/* skip over duplicate crc, compressed size and uncompressed size */
unzip_skip(src_fd, 12);
}
}
if (verbosity == v_list) {
printf(" -------- -------\n"
"%9d %d files\n", total_size, total_entries);
}
return failed;
}