unzip: handle "central directory"
needed for OpenOffice, gmail attachment .zips etc
conditional on CONFIG_DESKTOP
function old new delta
unzip_main 1643 1939 +296
find_cds_offset - 173 +173
unzip_skip 11 16 +5
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 2/0 up/down: 474/0) Total: 474 bytes
diff --git a/archival/unzip.c b/archival/unzip.c
index 1c9bc24..e468ff4 100644
--- a/archival/unzip.c
+++ b/archival/unzip.c
@@ -16,12 +16,7 @@
*/
/* 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"
@@ -31,12 +26,12 @@
#if BB_BIG_ENDIAN
ZIP_FILEHEADER_MAGIC = 0x504b0304,
ZIP_CDS_MAGIC = 0x504b0102,
- ZIP_CDS_END_MAGIC = 0x504b0506,
+ ZIP_CDE_MAGIC = 0x504b0506,
ZIP_DD_MAGIC = 0x504b0708,
#else
ZIP_FILEHEADER_MAGIC = 0x04034b50,
ZIP_CDS_MAGIC = 0x02014b50,
- ZIP_CDS_END_MAGIC = 0x06054b50,
+ ZIP_CDE_MAGIC = 0x06054b50,
ZIP_DD_MAGIC = 0x08074b50,
#endif
};
@@ -46,16 +41,16 @@
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 PACKED; /* 10-13 */
- uint32_t cmpsize PACKED; /* 14-17 */
- uint32_t ucmpsize PACKED; /* 18-21 */
- uint16_t filename_len; /* 22-23 */
- uint16_t extra_len; /* 24-25 */
+ 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 PACKED; /* 10-13 */
+ uint32_t cmpsize PACKED; /* 14-17 */
+ uint32_t ucmpsize PACKED; /* 18-21 */
+ uint16_t filename_len; /* 22-23 */
+ uint16_t extra_len; /* 24-25 */
} formatted PACKED;
} zip_header_t; /* PACKED - gcc 4.2.1 doesn't like it (spews warning) */
@@ -65,11 +60,11 @@
*/
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];
+ offsetof(zip_header_t, formatted.extra_len) + 2
+ == ZIP_HEADER_LEN ? 1 : -1];
};
-#define FIX_ENDIANNESS(zip_header) do { \
+#define FIX_ENDIANNESS_ZIP(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 ); \
@@ -82,9 +77,138 @@
(zip_header).formatted.extra_len = SWAP_LE16((zip_header).formatted.extra_len ); \
} while (0)
-static void unzip_skip(int fd, off_t skip)
+#define CDS_HEADER_LEN 42
+
+typedef union {
+ uint8_t raw[CDS_HEADER_LEN];
+ struct {
+ /* uint32_t signature; 50 4b 01 02 */
+ uint16_t version_made_by; /* 0-1 */
+ uint16_t version_needed; /* 2-3 */
+ uint16_t cds_flags; /* 4-5 */
+ uint16_t method; /* 6-7 */
+ uint16_t mtime; /* 8-9 */
+ uint16_t mdate; /* 10-11 */
+ uint32_t crc32; /* 12-15 */
+ uint32_t cmpsize; /* 16-19 */
+ uint32_t ucmpsize; /* 20-23 */
+ uint16_t file_name_length; /* 24-25 */
+ uint16_t extra_field_length; /* 26-27 */
+ uint16_t file_comment_length; /* 28-29 */
+ uint16_t disk_number_start; /* 30-31 */
+ uint16_t internal_file_attributes; /* 32-33 */
+ uint32_t external_file_attributes PACKED; /* 34-37 */
+ uint32_t relative_offset_of_local_header PACKED; /* 38-41 */
+ } formatted PACKED;
+} cds_header_t;
+
+struct BUG_cds_header_must_be_42_bytes {
+ char BUG_cds_header_must_be_42_bytes[
+ offsetof(cds_header_t, formatted.relative_offset_of_local_header) + 4
+ == CDS_HEADER_LEN ? 1 : -1];
+};
+
+#define FIX_ENDIANNESS_CDS(cds_header) do { \
+ (cds_header).formatted.crc32 = SWAP_LE32((cds_header).formatted.crc32 ); \
+ (cds_header).formatted.cmpsize = SWAP_LE32((cds_header).formatted.cmpsize ); \
+ (cds_header).formatted.ucmpsize = SWAP_LE32((cds_header).formatted.ucmpsize ); \
+ (cds_header).formatted.file_name_length = SWAP_LE16((cds_header).formatted.file_name_length); \
+ (cds_header).formatted.extra_field_length = SWAP_LE16((cds_header).formatted.extra_field_length); \
+ (cds_header).formatted.file_comment_length = SWAP_LE16((cds_header).formatted.file_comment_length); \
+} while (0)
+
+#define CDE_HEADER_LEN 16
+
+typedef union {
+ uint8_t raw[CDE_HEADER_LEN];
+ struct {
+ /* uint32_t signature; 50 4b 05 06 */
+ uint16_t this_disk_no;
+ uint16_t disk_with_cds_no;
+ uint16_t cds_entries_on_this_disk;
+ uint16_t cds_entries_total;
+ uint32_t cds_size;
+ uint32_t cds_offset;
+ /* uint16_t file_comment_length; */
+ /* .ZIP file comment (variable size) */
+ } formatted PACKED;
+} cde_header_t;
+
+struct BUG_cde_header_must_be_16_bytes {
+ char BUG_cde_header_must_be_16_bytes[
+ sizeof(cde_header_t) == CDE_HEADER_LEN ? 1 : -1];
+};
+
+#define FIX_ENDIANNESS_CDE(cde_header) do { \
+ (cde_header).formatted.cds_offset = SWAP_LE16((cde_header).formatted.cds_offset); \
+} while (0)
+
+enum { zip_fd = 3 };
+
+
+#if ENABLE_DESKTOP
+/* NB: does not preserve file position! */
+static uint32_t find_cds_offset(void)
{
- bb_copyfd_exact_size(fd, -1, skip);
+ unsigned char buf[1024];
+ cde_header_t cde_header;
+ unsigned char *p;
+ off_t end;
+
+ end = xlseek(zip_fd, 0, SEEK_END);
+ if (end < 1024)
+ end = 1024;
+ end -= 1024;
+ xlseek(zip_fd, end, SEEK_SET);
+ full_read(zip_fd, buf, 1024);
+
+ p = buf;
+ while (p <= buf + 1024 - CDE_HEADER_LEN - 4) {
+ if (*p != 'P') {
+ p++;
+ continue;
+ }
+ if (*++p != 'K')
+ continue;
+ if (*++p != 5)
+ continue;
+ if (*++p != 6)
+ continue;
+ /* we found CDE! */
+ memcpy(cde_header.raw, p + 1, CDE_HEADER_LEN);
+ FIX_ENDIANNESS_CDE(cde_header);
+ return cde_header.formatted.cds_offset;
+ }
+ bb_error_msg_and_die("can't find file table");
+};
+
+static uint32_t read_next_cds(int count_m1, uint32_t cds_offset, cds_header_t *cds_ptr)
+{
+ off_t org;
+
+ org = xlseek(zip_fd, 0, SEEK_CUR);
+
+ if (!cds_offset)
+ cds_offset = find_cds_offset();
+
+ while (count_m1-- >= 0) {
+ xlseek(zip_fd, cds_offset + 4, SEEK_SET);
+ xread(zip_fd, cds_ptr->raw, CDS_HEADER_LEN);
+ FIX_ENDIANNESS_CDS(*cds_ptr);
+ cds_offset += 4 + CDS_HEADER_LEN
+ + cds_ptr->formatted.file_name_length
+ + cds_ptr->formatted.extra_field_length
+ + cds_ptr->formatted.file_comment_length;
+ }
+
+ xlseek(zip_fd, org, SEEK_SET);
+ return cds_offset;
+};
+#endif
+
+static void unzip_skip(off_t skip)
+{
+ bb_copyfd_exact_size(zip_fd, -1, skip);
}
static void unzip_create_leading_dirs(const char *fn)
@@ -97,17 +221,17 @@
free(name);
}
-static void unzip_extract(zip_header_t *zip_header, int src_fd, int dst_fd)
+static void unzip_extract(zip_header_t *zip_header, 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);
+ bb_copyfd_exact_size(zip_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)
+ if (inflate_unzip(&res, zip_header->formatted.cmpsize, zip_fd, dst_fd) < 0)
bb_error_msg_and_die("inflate error");
/* Validate decompression - crc */
if (zip_header->formatted.crc32 != (res.crc ^ 0xffffffffL)) {
@@ -131,9 +255,12 @@
smallint verbose = 1;
smallint listing = 0;
smallint overwrite = O_PROMPT;
+#if ENABLE_DESKTOP
+ uint32_t cds_offset;
+ unsigned cds_entries;
+#endif
unsigned total_size;
unsigned total_entries;
- int src_fd = -1;
int dst_fd = -1;
char *src_fn = NULL;
char *dst_fn = NULL;
@@ -221,13 +348,14 @@
/* Open input file */
if (LONE_DASH(src_fn)) {
- src_fd = STDIN_FILENO;
+ xdup2(STDIN_FILENO, zip_fd);
/* 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);
+ int src_fd = -1;
for (i = 0; (i < 3) && (src_fd == -1); i++) {
strcpy(src_fn + orig_src_fn_len, extn[i]);
@@ -237,6 +365,7 @@
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);
}
+ xmove_fd(src_fd, zip_fd);
}
/* Change dir if necessary */
@@ -253,37 +382,63 @@
total_size = 0;
total_entries = 0;
+#if ENABLE_DESKTOP
+ cds_entries = 0;
+ cds_offset = 0;
+#endif
while (1) {
uint32_t magic;
/* Check magic number */
- xread(src_fd, &magic, 4);
+ xread(zip_fd, &magic, 4);
/* Central directory? It's at the end, so exit */
if (magic == ZIP_CDS_MAGIC)
break;
+#if ENABLE_DESKTOP
+ /* Data descriptor? It was a streaming file, go on */
+ if (magic == ZIP_DD_MAGIC) {
+ /* skip over duplicate crc32, cmpsize and ucmpsize */
+ unzip_skip(3 * 4);
+ continue;
+ }
+#endif
if (magic != ZIP_FILEHEADER_MAGIC)
bb_error_msg_and_die("invalid zip magic %08X", (int)magic);
/* Read the file header */
- xread(src_fd, zip_header.raw, ZIP_HEADER_LEN);
- FIX_ENDIANNESS(zip_header);
+ xread(zip_fd, zip_header.raw, ZIP_HEADER_LEN);
+ FIX_ENDIANNESS_ZIP(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);
}
- if (zip_header.formatted.flags & (0x0008|0x0001)) {
+#if !ENABLE_DESKTOP
+ if (zip_header.formatted.flags & 0x0009) {
+ bb_error_msg_and_die("zip flags 1 and 8 are not supported");
+ }
+#else
+ if (zip_header.formatted.flags & 0x0001) {
/* 0x0001 - encrypted */
+ bb_error_msg_and_die("zip flag 1 (encryption) is not supported");
+ }
+ if (zip_header.formatted.flags & 0x0008) {
+ cds_header_t cds_header;
/* 0x0008 - streaming. [u]cmpsize can be reliably gotten
* only from Central Directory. See unzip_doc.txt */
- bb_error_msg_and_die("zip flags 8 and 1 are not supported");
+ cds_offset = read_next_cds(total_entries - cds_entries, cds_offset, &cds_header);
+ cds_entries = total_entries + 1;
+ zip_header.formatted.crc32 = cds_header.formatted.crc32;
+ zip_header.formatted.cmpsize = cds_header.formatted.cmpsize;
+ zip_header.formatted.ucmpsize = cds_header.formatted.ucmpsize;
}
+#endif
/* Read filename */
free(dst_fn);
dst_fn = xzalloc(zip_header.formatted.filename_len + 1);
- xread(src_fd, dst_fn, zip_header.formatted.filename_len);
+ xread(zip_fd, dst_fn, zip_header.formatted.filename_len);
/* Skip extra header bytes */
- unzip_skip(src_fd, zip_header.formatted.extra_len);
+ unzip_skip(zip_header.formatted.extra_len);
/* Filter zip entries */
if (find_list_entry(zreject, dst_fn)
@@ -304,7 +459,6 @@
(dostime & 0x000007e0) >> 5,
dst_fn);
total_size += zip_header.formatted.ucmpsize;
- total_entries++;
} else {
/* short listing -- filenames only */
puts(dst_fn);
@@ -315,7 +469,7 @@
} 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);
+ bb_perror_msg_and_die("can't stat '%s'", dst_fn);
}
if (verbose) {
printf(" creating: %s\n", dst_fn);
@@ -335,7 +489,7 @@
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);
+ bb_perror_msg_and_die("can't stat '%s'", dst_fn);
}
i = 'y';
} else { /* File already exists */
@@ -347,7 +501,7 @@
} 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");
+ bb_perror_msg_and_die("can't read input");
}
i = key_buf[0];
}
@@ -368,7 +522,7 @@
if (verbose) {
printf(" inflating: %s\n", dst_fn);
}
- unzip_extract(&zip_header, src_fd, dst_fd);
+ unzip_extract(&zip_header, dst_fd);
if (dst_fd != STDOUT_FILENO) {
/* closing STDOUT is potentially bad for future business */
close(dst_fd);
@@ -379,14 +533,14 @@
overwrite = O_NEVER;
case 'n':
/* Skip entry data */
- unzip_skip(src_fd, zip_header.formatted.cmpsize);
+ unzip_skip(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");
+ bb_perror_msg_and_die("can't read input");
}
free(dst_fn);
dst_fn = xstrdup(key_buf);
@@ -398,12 +552,7 @@
goto check_file;
}
-// Looks like bug (data descriptor cannot be identified this way)
-// /* Data descriptor section */
-// if (zip_header.formatted.flags & 4) {
-// /* skip over duplicate crc, compressed size and uncompressed size */
-// unzip_skip(src_fd, 12);
-// }
+ total_entries++;
}
if (listing && verbose) {