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unzip: handle "central directory"

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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
This commit is contained in:
Denis Vlasenko 2008-09-21 01:01:46 +00:00
parent eef6077d7e
commit 006e8628fc
1 changed files with 196 additions and 47 deletions
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223
archival/unzip.c
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@ -16,12 +16,7 @@
*/ */
/* TODO /* TODO
* Endian issues
* Zip64 + other methods * 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 "libbb.h"
@ -31,12 +26,12 @@ enum {
#if BB_BIG_ENDIAN #if BB_BIG_ENDIAN
ZIP_FILEHEADER_MAGIC = 0x504b0304, ZIP_FILEHEADER_MAGIC = 0x504b0304,
ZIP_CDS_MAGIC = 0x504b0102, ZIP_CDS_MAGIC = 0x504b0102,
ZIP_CDS_END_MAGIC = 0x504b0506, ZIP_CDE_MAGIC = 0x504b0506,
ZIP_DD_MAGIC = 0x504b0708, ZIP_DD_MAGIC = 0x504b0708,
#else #else
ZIP_FILEHEADER_MAGIC = 0x04034b50, ZIP_FILEHEADER_MAGIC = 0x04034b50,
ZIP_CDS_MAGIC = 0x02014b50, ZIP_CDS_MAGIC = 0x02014b50,
ZIP_CDS_END_MAGIC = 0x06054b50, ZIP_CDE_MAGIC = 0x06054b50,
ZIP_DD_MAGIC = 0x08074b50, ZIP_DD_MAGIC = 0x08074b50,
#endif #endif
}; };
@ -65,11 +60,11 @@ typedef union {
*/ */
struct BUG_zip_header_must_be_26_bytes { struct BUG_zip_header_must_be_26_bytes {
char BUG_zip_header_must_be_26_bytes[ char BUG_zip_header_must_be_26_bytes[
offsetof(zip_header_t, formatted.extra_len) + 2 == offsetof(zip_header_t, formatted.extra_len) + 2
ZIP_HEADER_LEN ? 1 : -1]; == 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.version = SWAP_LE16((zip_header).formatted.version ); \
(zip_header).formatted.flags = SWAP_LE16((zip_header).formatted.flags ); \ (zip_header).formatted.flags = SWAP_LE16((zip_header).formatted.flags ); \
(zip_header).formatted.method = SWAP_LE16((zip_header).formatted.method ); \ (zip_header).formatted.method = SWAP_LE16((zip_header).formatted.method ); \
@ -82,9 +77,138 @@ struct BUG_zip_header_must_be_26_bytes {
(zip_header).formatted.extra_len = SWAP_LE16((zip_header).formatted.extra_len ); \ (zip_header).formatted.extra_len = SWAP_LE16((zip_header).formatted.extra_len ); \
} while (0) } 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) static void unzip_create_leading_dirs(const char *fn)
@ -97,17 +221,17 @@ static void unzip_create_leading_dirs(const char *fn)
free(name); 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) { if (zip_header->formatted.method == 0) {
/* Method 0 - stored (not compressed) */ /* Method 0 - stored (not compressed) */
off_t size = zip_header->formatted.ucmpsize; off_t size = zip_header->formatted.ucmpsize;
if (size) if (size)
bb_copyfd_exact_size(src_fd, dst_fd, size); bb_copyfd_exact_size(zip_fd, dst_fd, size);
} else { } else {
/* Method 8 - inflate */ /* Method 8 - inflate */
inflate_unzip_result res; 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"); bb_error_msg_and_die("inflate error");
/* Validate decompression - crc */ /* Validate decompression - crc */
if (zip_header->formatted.crc32 != (res.crc ^ 0xffffffffL)) { if (zip_header->formatted.crc32 != (res.crc ^ 0xffffffffL)) {
@ -131,9 +255,12 @@ int unzip_main(int argc, char **argv)
smallint verbose = 1; smallint verbose = 1;
smallint listing = 0; smallint listing = 0;
smallint overwrite = O_PROMPT; smallint overwrite = O_PROMPT;
#if ENABLE_DESKTOP
uint32_t cds_offset;
unsigned cds_entries;
#endif
unsigned total_size; unsigned total_size;
unsigned total_entries; unsigned total_entries;
int src_fd = -1;
int dst_fd = -1; int dst_fd = -1;
char *src_fn = NULL; char *src_fn = NULL;
char *dst_fn = NULL; char *dst_fn = NULL;
@ -221,13 +348,14 @@ int unzip_main(int argc, char **argv)
/* Open input file */ /* Open input file */
if (LONE_DASH(src_fn)) { 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 */ /* Cannot use prompt mode since zip data is arriving on STDIN */
if (overwrite == O_PROMPT) if (overwrite == O_PROMPT)
overwrite = O_NEVER; overwrite = O_NEVER;
} else { } else {
static const char extn[][5] = {"", ".zip", ".ZIP"}; static const char extn[][5] = {"", ".zip", ".ZIP"};
int orig_src_fn_len = strlen(src_fn); int orig_src_fn_len = strlen(src_fn);
int src_fd = -1;
for (i = 0; (i < 3) && (src_fd == -1); i++) { for (i = 0; (i < 3) && (src_fd == -1); i++) {
strcpy(src_fn + orig_src_fn_len, extn[i]); strcpy(src_fn + orig_src_fn_len, extn[i]);
@ -237,6 +365,7 @@ int unzip_main(int argc, char **argv)
src_fn[orig_src_fn_len] = '\0'; 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); 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 */ /* Change dir if necessary */
@ -253,37 +382,63 @@ int unzip_main(int argc, char **argv)
total_size = 0; total_size = 0;
total_entries = 0; total_entries = 0;
#if ENABLE_DESKTOP
cds_entries = 0;
cds_offset = 0;
#endif
while (1) { while (1) {
uint32_t magic; uint32_t magic;
/* Check magic number */ /* Check magic number */
xread(src_fd, &magic, 4); xread(zip_fd, &magic, 4);
/* Central directory? It's at the end, so exit */ /* Central directory? It's at the end, so exit */
if (magic == ZIP_CDS_MAGIC) if (magic == ZIP_CDS_MAGIC)
break; 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) if (magic != ZIP_FILEHEADER_MAGIC)
bb_error_msg_and_die("invalid zip magic %08X", (int)magic); bb_error_msg_and_die("invalid zip magic %08X", (int)magic);
/* Read the file header */ /* Read the file header */
xread(src_fd, zip_header.raw, ZIP_HEADER_LEN); xread(zip_fd, zip_header.raw, ZIP_HEADER_LEN);
FIX_ENDIANNESS(zip_header); FIX_ENDIANNESS_ZIP(zip_header);
if ((zip_header.formatted.method != 0) && (zip_header.formatted.method != 8)) { if ((zip_header.formatted.method != 0) && (zip_header.formatted.method != 8)) {
bb_error_msg_and_die("unsupported method %d", zip_header.formatted.method); 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 */ /* 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 /* 0x0008 - streaming. [u]cmpsize can be reliably gotten
* only from Central Directory. See unzip_doc.txt */ * 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 */ /* Read filename */
free(dst_fn); free(dst_fn);
dst_fn = xzalloc(zip_header.formatted.filename_len + 1); 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 */ /* Skip extra header bytes */
unzip_skip(src_fd, zip_header.formatted.extra_len); unzip_skip(zip_header.formatted.extra_len);
/* Filter zip entries */ /* Filter zip entries */
if (find_list_entry(zreject, dst_fn) if (find_list_entry(zreject, dst_fn)
@ -304,7 +459,6 @@ int unzip_main(int argc, char **argv)
(dostime & 0x000007e0) >> 5, (dostime & 0x000007e0) >> 5,
dst_fn); dst_fn);
total_size += zip_header.formatted.ucmpsize; total_size += zip_header.formatted.ucmpsize;
total_entries++;
} else { } else {
/* short listing -- filenames only */ /* short listing -- filenames only */
puts(dst_fn); puts(dst_fn);
@ -315,7 +469,7 @@ int unzip_main(int argc, char **argv)
} else if (last_char_is(dst_fn, '/')) { /* Extract directory */ } else if (last_char_is(dst_fn, '/')) { /* Extract directory */
if (stat(dst_fn, &stat_buf) == -1) { if (stat(dst_fn, &stat_buf) == -1) {
if (errno != ENOENT) { 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) { if (verbose) {
printf(" creating: %s\n", dst_fn); printf(" creating: %s\n", dst_fn);
@ -335,7 +489,7 @@ int unzip_main(int argc, char **argv)
check_file: check_file:
if (stat(dst_fn, &stat_buf) == -1) { /* File does not exist */ if (stat(dst_fn, &stat_buf) == -1) { /* File does not exist */
if (errno != ENOENT) { 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'; i = 'y';
} else { /* File already exists */ } else { /* File already exists */
@ -347,7 +501,7 @@ int unzip_main(int argc, char **argv)
} else { } else {
printf("replace %s? [y]es, [n]o, [A]ll, [N]one, [r]ename: ", dst_fn); printf("replace %s? [y]es, [n]o, [A]ll, [N]one, [r]ename: ", dst_fn);
if (!fgets(key_buf, sizeof(key_buf), stdin)) { 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]; i = key_buf[0];
} }
@ -368,7 +522,7 @@ int unzip_main(int argc, char **argv)
if (verbose) { if (verbose) {
printf(" inflating: %s\n", dst_fn); 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) { if (dst_fd != STDOUT_FILENO) {
/* closing STDOUT is potentially bad for future business */ /* closing STDOUT is potentially bad for future business */
close(dst_fd); close(dst_fd);
@ -379,14 +533,14 @@ int unzip_main(int argc, char **argv)
overwrite = O_NEVER; overwrite = O_NEVER;
case 'n': case 'n':
/* Skip entry data */ /* Skip entry data */
unzip_skip(src_fd, zip_header.formatted.cmpsize); unzip_skip(zip_header.formatted.cmpsize);
break; break;
case 'r': case 'r':
/* Prompt for new name */ /* Prompt for new name */
printf("new name: "); printf("new name: ");
if (!fgets(key_buf, sizeof(key_buf), stdin)) { 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); free(dst_fn);
dst_fn = xstrdup(key_buf); dst_fn = xstrdup(key_buf);
@ -398,12 +552,7 @@ int unzip_main(int argc, char **argv)
goto check_file; goto check_file;
} }
// Looks like bug (data descriptor cannot be identified this way) total_entries++;
// /* 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) { if (listing && verbose) {