busybox/archival/ar.c
Denys Vlasenko 4eed2c6c50 Update menuconfig items with approximate applet sizes
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2017-07-18 22:01:24 +02:00

295 lines
8.4 KiB
C

/* vi: set sw=4 ts=4: */
/*
* Mini ar implementation for busybox
*
* Copyright (C) 2000 by Glenn McGrath
*
* Based in part on BusyBox tar, Debian dpkg-deb and GNU ar.
*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*
* Archive creation support:
* Copyright (C) 2010 Nokia Corporation. All rights reserved.
* Written by Alexander Shishkin.
*
* There is no single standard to adhere to so ar may not portable
* between different systems
* http://www.unix-systems.org/single_unix_specification_v2/xcu/ar.html
*/
//config:config AR
//config: bool "ar (9.5 kb)"
//config: default n # needs to be improved to be able to replace binutils ar
//config: help
//config: ar is an archival utility program used to create, modify, and
//config: extract contents from archives. In practice, it is used exclusively
//config: for object module archives used by compilers.
//config:
//config: On an x86 system, the ar applet adds about 1K.
//config:
//config: Unless you have a specific application which requires ar, you should
//config: probably say N here: most compilers come with their own ar utility.
//config:
//config:config FEATURE_AR_LONG_FILENAMES
//config: bool "Support long filenames (not needed for debs)"
//config: default y
//config: depends on AR
//config: help
//config: By default the ar format can only store the first 15 characters
//config: of the filename, this option removes that limitation.
//config: It supports the GNU ar long filename method which moves multiple long
//config: filenames into a the data section of a new ar entry.
//config:
//config:config FEATURE_AR_CREATE
//config: bool "Support archive creation"
//config: default y
//config: depends on AR
//config: help
//config: This enables archive creation (-c and -r) with busybox ar.
//applet:IF_AR(APPLET(ar, BB_DIR_USR_BIN, BB_SUID_DROP))
//kbuild:lib-$(CONFIG_AR) += ar.o
//usage:#define ar_trivial_usage
//usage: "[-o] [-v] [-p] [-t] [-x] ARCHIVE FILES"
//usage:#define ar_full_usage "\n\n"
//usage: "Extract or list FILES from an ar archive\n"
//usage: "\n -o Preserve original dates"
//usage: "\n -p Extract to stdout"
//usage: "\n -t List"
//usage: "\n -x Extract"
//usage: "\n -v Verbose"
#include "libbb.h"
#include "bb_archive.h"
#include "ar.h"
#if ENABLE_FEATURE_AR_CREATE
/* filter out entries with same names as specified on the command line */
static char FAST_FUNC filter_replaceable(archive_handle_t *handle)
{
if (find_list_entry(handle->accept, handle->file_header->name))
return EXIT_FAILURE;
return EXIT_SUCCESS;
}
static void output_ar_header(archive_handle_t *handle)
{
/* GNU ar 2.19.51.0.14 creates malformed archives
* if input files are >10G. It also truncates files >4GB
* (uses "size mod 4G"). We abort in this case:
* We could add support for up to 10G files, but this is unlikely to be useful.
* Note that unpacking side limits all fields to "unsigned int" data type,
* and treats "all ones" as an error indicator. Thus max we allow here is UINT_MAX-1.
*/
enum {
/* for 2nd field: mtime */
MAX11CHARS = UINT_MAX > 0xffffffff ? (unsigned)99999999999 : UINT_MAX-1,
/* for last field: filesize */
MAX10CHARS = UINT_MAX > 0xffffffff ? (unsigned)9999999999 : UINT_MAX-1,
};
struct file_header_t *fh = handle->file_header;
if (handle->offset & 1) {
xwrite(handle->src_fd, "\n", 1);
handle->offset++;
}
/* Careful! The widths should be exact. Fields must be separated */
if (sizeof(off_t) > 4 && fh->size > (off_t)MAX10CHARS) {
bb_error_msg_and_die("'%s' is bigger than ar can handle", fh->name);
}
fdprintf(handle->src_fd, "%-16.16s%-12lu%-6u%-6u%-8o%-10"OFF_FMT"u`\n",
fh->name,
(sizeof(time_t) > 4 && fh->mtime > MAX11CHARS) ? (long)0 : (long)fh->mtime,
fh->uid > 99999 ? 0 : (int)fh->uid,
fh->gid > 99999 ? 0 : (int)fh->gid,
(int)fh->mode & 07777777,
fh->size
);
handle->offset += AR_HEADER_LEN;
}
/*
* when replacing files in an existing archive, copy from the
* original archive those files that are to be left intact
*/
static void FAST_FUNC copy_data(archive_handle_t *handle)
{
archive_handle_t *out_handle = handle->ar__out;
struct file_header_t *fh = handle->file_header;
out_handle->file_header = fh;
output_ar_header(out_handle);
bb_copyfd_exact_size(handle->src_fd, out_handle->src_fd, fh->size);
out_handle->offset += fh->size;
}
static int write_ar_header(archive_handle_t *handle)
{
char *fn;
char fn_h[17]; /* 15 + "/" + NUL */
struct stat st;
int fd;
fn = llist_pop(&handle->accept);
if (!fn)
return -1;
xstat(fn, &st);
handle->file_header->mtime = st.st_mtime;
handle->file_header->uid = st.st_uid;
handle->file_header->gid = st.st_gid;
handle->file_header->mode = st.st_mode;
handle->file_header->size = st.st_size;
handle->file_header->name = fn_h;
//TODO: if ENABLE_FEATURE_AR_LONG_FILENAMES...
sprintf(fn_h, "%.15s/", bb_basename(fn));
output_ar_header(handle);
fd = xopen(fn, O_RDONLY);
bb_copyfd_exact_size(fd, handle->src_fd, st.st_size);
close(fd);
handle->offset += st.st_size;
return 0;
}
static int write_ar_archive(archive_handle_t *handle)
{
struct stat st;
archive_handle_t *out_handle;
xfstat(handle->src_fd, &st, handle->ar__name);
/* if archive exists, create a new handle for output.
* we create it in place of the old one.
*/
if (st.st_size != 0) {
out_handle = init_handle();
xunlink(handle->ar__name);
out_handle->src_fd = xopen(handle->ar__name, O_WRONLY | O_CREAT | O_TRUNC);
out_handle->accept = handle->accept;
} else {
out_handle = handle;
}
handle->ar__out = out_handle;
xwrite(out_handle->src_fd, AR_MAGIC "\n", AR_MAGIC_LEN + 1);
out_handle->offset += AR_MAGIC_LEN + 1;
/* skip to the end of the archive if we have to append stuff */
if (st.st_size != 0) {
handle->filter = filter_replaceable;
handle->action_data = copy_data;
unpack_ar_archive(handle);
}
while (write_ar_header(out_handle) == 0)
continue;
/* optional, since we exit right after we return */
if (ENABLE_FEATURE_CLEAN_UP) {
close(handle->src_fd);
if (out_handle->src_fd != handle->src_fd)
close(out_handle->src_fd);
}
return EXIT_SUCCESS;
}
#endif /* FEATURE_AR_CREATE */
static void FAST_FUNC header_verbose_list_ar(const file_header_t *file_header)
{
const char *mode = bb_mode_string(file_header->mode);
char *mtime;
mtime = ctime(&file_header->mtime);
mtime[16] = ' ';
memmove(&mtime[17], &mtime[20], 4);
mtime[21] = '\0';
printf("%s %u/%u%7"OFF_FMT"u %s %s\n", &mode[1],
(int)file_header->uid, (int)file_header->gid,
file_header->size,
&mtime[4], file_header->name
);
}
#define AR_OPT_VERBOSE (1 << 0)
#define AR_OPT_PRESERVE_DATE (1 << 1)
/* "ar r" implies create, but warns about it. c suppresses warning.
* bbox accepts but ignores it: */
#define AR_OPT_CREATE (1 << 2)
#define AR_CMD_PRINT (1 << 3)
#define FIRST_CMD AR_CMD_PRINT
#define AR_CMD_LIST (1 << 4)
#define AR_CMD_EXTRACT (1 << 5)
#define AR_CMD_INSERT (1 << 6)
int ar_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int ar_main(int argc UNUSED_PARAM, char **argv)
{
archive_handle_t *archive_handle;
unsigned opt, t;
archive_handle = init_handle();
/* --: prepend '-' to the first argument if required */
/* -1: at least one param is reqd */
/* one of p,t,x[,r] is required */
opt_complementary = "--:-1:p:t:x"IF_FEATURE_AR_CREATE(":r");
opt = getopt32(argv, "voc""ptx"IF_FEATURE_AR_CREATE("r"));
argv += optind;
t = opt / FIRST_CMD;
if (t & (t-1)) /* more than one of p,t,x[,r] are specified */
bb_show_usage();
if (opt & AR_CMD_PRINT) {
archive_handle->action_data = data_extract_to_stdout;
}
if (opt & AR_CMD_LIST) {
archive_handle->action_header = header_list;
}
if (opt & AR_CMD_EXTRACT) {
archive_handle->action_data = data_extract_all;
}
if (opt & AR_OPT_PRESERVE_DATE) {
archive_handle->ah_flags |= ARCHIVE_RESTORE_DATE;
}
if (opt & AR_OPT_VERBOSE) {
archive_handle->action_header = header_verbose_list_ar;
}
#if ENABLE_FEATURE_AR_CREATE
archive_handle->ar__name = *argv;
#endif
archive_handle->src_fd = xopen(*argv++,
(opt & AR_CMD_INSERT)
? O_RDWR | O_CREAT
: O_RDONLY
);
if (*argv)
archive_handle->filter = filter_accept_list;
while (*argv) {
llist_add_to_end(&archive_handle->accept, *argv++);
}
#if ENABLE_FEATURE_AR_CREATE
if (opt & AR_CMD_INSERT)
return write_ar_archive(archive_handle);
#endif
unpack_ar_archive(archive_handle);
return EXIT_SUCCESS;
}