[PATCH 1/2] ar: add archive creation
Alexander Shishkin
virtuoso at slind.org
Fri Mar 12 12:49:19 UTC 2010
This implements archive creation in busybox ar. Long file names
support is to be implemented yet.
function old new delta
write_ar_archive - 226 +226
write_ar_header - 218 +218
output_ar_header - 92 +92
copy_data - 58 +58
ar_main 191 240 +49
filter_replaceable - 25 +25
.rodata 42217 42223 +6
static.msg_unsupported_err 28 - -28
------------------------------------------------------------------------------
(add/remove: 6/1 grow/shrink: 2/0 up/down: 674/-28) Total: 646 bytes
Signed-off-by: Alexander Shishkin <virtuoso at slind.org>
---
archival/Config.in | 7 ++
archival/Kbuild | 1 +
archival/ar.c | 26 +++++-
archival/ar.h | 27 ++++++
archival/ar_create.c | 133 +++++++++++++++++++++++++++++
archival/libunarchive/get_header_ar.c | 11 +--
archival/libunarchive/unpack_ar_archive.c | 7 +-
include/unarchive.h | 4 +
8 files changed, 199 insertions(+), 17 deletions(-)
create mode 100644 archival/ar.h
create mode 100644 archival/ar_create.c
diff --git a/archival/Config.in b/archival/Config.in
index fb79c7b..9e2e88c 100644
--- a/archival/Config.in
+++ b/archival/Config.in
@@ -62,6 +62,13 @@ config FEATURE_AR_LONG_FILENAMES
It supports the GNU ar long filename method which moves multiple long
filenames into a the data section of a new ar entry.
+config FEATURE_AR_CREATE
+ bool "Support archive creation"
+ default n
+ depends on AR
+ help
+ This enables archive creation (-c and -r) with busybox ar.
+
config BUNZIP2
bool "bunzip2"
default n
diff --git a/archival/Kbuild b/archival/Kbuild
index 53bd7e2..dab3ab2 100644
--- a/archival/Kbuild
+++ b/archival/Kbuild
@@ -8,6 +8,7 @@ libs-y += libunarchive/
lib-y:=
lib-$(CONFIG_AR) += ar.o
+lib-$(CONFIG_FEATURE_AR_CREATE) += ar_create.o
lib-$(CONFIG_BUNZIP2) += bbunzip.o
lib-$(CONFIG_BZIP2) += bzip2.o bbunzip.o
lib-$(CONFIG_UNLZMA) += bbunzip.o
diff --git a/archival/ar.c b/archival/ar.c
index fd7f8e4..a5f3482 100644
--- a/archival/ar.c
+++ b/archival/ar.c
@@ -15,6 +15,12 @@
#include "libbb.h"
#include "unarchive.h"
+#include "ar.h"
+
+#if !ENABLE_FEATURE_AR_CREATE
+static const char msg_unsupported_err[] ALIGN1 =
+ "archive %s is not supported";
+#endif
static void FAST_FUNC header_verbose_list_ar(const file_header_t *file_header)
{
@@ -40,16 +46,14 @@ static void FAST_FUNC header_verbose_list_ar(const file_header_t *file_header)
int ar_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int ar_main(int argc UNUSED_PARAM, char **argv)
{
- static const char msg_unsupported_err[] ALIGN1 =
- "archive %s is not supported";
-
archive_handle_t *archive_handle;
unsigned opt;
+ bool wr = 0;
archive_handle = init_handle();
/* Prepend '-' to the first argument if required */
- opt_complementary = "--:p:t:x:-1:p--tx:t--px:x--pt";
+ opt_complementary = "--:p:t:x:-1:p--tx:t--px:x--pt:c:r";
opt = getopt32(argv, "ptxovcr");
argv += optind;
@@ -68,20 +72,32 @@ int ar_main(int argc UNUSED_PARAM, char **argv)
if (opt & AR_OPT_VERBOSE) {
archive_handle->action_header = header_verbose_list_ar;
}
+#if !ENABLE_FEATURE_AR_CREATE
if (opt & AR_OPT_CREATE) {
bb_error_msg_and_die(msg_unsupported_err, "creation");
}
if (opt & AR_OPT_INSERT) {
bb_error_msg_and_die(msg_unsupported_err, "insertion");
}
+#else
+ archive_handle->ar_name = *argv;
+#endif
- archive_handle->src_fd = xopen(*argv++, O_RDONLY);
+ wr = opt & (AR_OPT_CREATE | AR_OPT_INSERT);
+
+ archive_handle->src_fd = xopen(*argv++,
+ wr ? O_RDWR | O_CREAT : O_RDONLY);
while (*argv) {
archive_handle->filter = filter_accept_list;
llist_add_to(&archive_handle->accept, *argv++);
}
+#if ENABLE_FEATURE_AR_CREATE
+ if (wr)
+ return write_ar_archive(archive_handle, opt & AR_OPT_INSERT);
+#endif
+
unpack_ar_archive(archive_handle);
return EXIT_SUCCESS;
diff --git a/archival/ar.h b/archival/ar.h
new file mode 100644
index 0000000..5e8c6f8
--- /dev/null
+++ b/archival/ar.h
@@ -0,0 +1,27 @@
+/*
+ * busybox ar archive data structures
+ * Licensed under the GPL v2 or later, see the file LICENSE in this source tree.
+ */
+
+#ifndef AR_H
+#define AR_H
+
+struct ar_header {
+ char name[16];
+ char date[12];
+ char uid[6];
+ char gid[6];
+ char mode[8];
+ char size[10];
+ char magic[2];
+};
+
+#define AR_HEADER_LEN sizeof(struct ar_header)
+#define AR_MAGIC "!<arch>"
+#define AR_MAGIC_LEN 7
+
+#if ENABLE_FEATURE_AR_CREATE
+int write_ar_archive(archive_handle_t *handle, int append);
+#endif
+
+#endif
diff --git a/archival/ar_create.c b/archival/ar_create.c
new file mode 100644
index 0000000..8076685
--- /dev/null
+++ b/archival/ar_create.c
@@ -0,0 +1,133 @@
+/*
+ * ar archive creation support
+ *
+ * Copyright (C) 2010 Nokia Corporation. All rights reserved.
+ * Written by Alexander Shishkin.
+ *
+ * Licensed under GPLv2 or later, see file LICENSE in the source tree for details.
+ */
+
+#include "libbb.h"
+#include "unarchive.h"
+#include "ar.h"
+
+/* 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 FAST_FUNC output_ar_header(archive_handle_t *handle)
+{
+ struct file_header_t *fh = handle->file_header;
+
+ if (handle->offset & 1) {
+ xwrite(handle->src_fd, "\n", 1);
+ handle->offset++;
+ }
+
+ dprintf(handle->src_fd, "%-16s%-12lu%-6u%-6u%-8o%-10llu`\n",
+ fh->name, fh->mtime, fh->uid, fh->gid, fh->mode, fh->size);
+
+ handle->offset += AR_HEADER_LEN;
+}
+
+/*
+ * when replacing files in an existing archive, copy from the 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 = llist_pop(&(handle->accept));
+ char fn_h[FILENAME_MAX];
+ struct stat st;
+ int fd;
+
+ 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;
+
+#if ENABLE_FEATURE_AR_LONG_FILENAMES
+#error nope, not yet
+#else
+ snprintf(fn_h, 17, "%.15s/", bb_basename(fn));
+#endif
+ 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;
+}
+
+int write_ar_archive(archive_handle_t *handle, int append)
+{
+ struct stat st;
+ archive_handle_t *out_handle;
+
+ if (fstat(handle->src_fd, &st) < 0)
+ return EXIT_FAILURE;
+
+ /*
+ * if we're appending/replacing stuff in an existing archive,
+ * create a new handle for output, which is a new file created
+ * in place of the old one
+ */
+ if (append && st.st_size) {
+ out_handle = init_handle();
+
+ unlink(handle->ar_name);
+ out_handle->src_fd = xopen(handle->ar_name, O_WRONLY | O_CREAT);
+ 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 (append && st.st_size) {
+ handle->filter = filter_replaceable;
+ handle->action_data = copy_data;
+ unpack_ar_archive(handle);
+ }
+
+ while (!write_ar_header(out_handle))
+ ;
+
+ close(handle->src_fd);
+
+ if (out_handle->src_fd != handle->src_fd)
+ close(out_handle->src_fd);
+
+ return EXIT_SUCCESS;
+}
+
diff --git a/archival/libunarchive/get_header_ar.c b/archival/libunarchive/get_header_ar.c
index 2f38279..31dc3e8 100644
--- a/archival/libunarchive/get_header_ar.c
+++ b/archival/libunarchive/get_header_ar.c
@@ -6,6 +6,7 @@
#include "libbb.h"
#include "unarchive.h"
+#include "../ar.h"
static unsigned read_num(const char *str, int base)
{
@@ -23,15 +24,7 @@ char FAST_FUNC get_header_ar(archive_handle_t *archive_handle)
unsigned size;
union {
char raw[60];
- struct {
- char name[16];
- char date[12];
- char uid[6];
- char gid[6];
- char mode[8];
- char size[10];
- char magic[2];
- } formatted;
+ struct ar_header formatted;
} ar;
#if ENABLE_FEATURE_AR_LONG_FILENAMES
static char *ar_long_names;
diff --git a/archival/libunarchive/unpack_ar_archive.c b/archival/libunarchive/unpack_ar_archive.c
index dc2eec2..db0e616 100644
--- a/archival/libunarchive/unpack_ar_archive.c
+++ b/archival/libunarchive/unpack_ar_archive.c
@@ -5,16 +5,17 @@
#include "libbb.h"
#include "unarchive.h"
+#include "../ar.h"
void FAST_FUNC unpack_ar_archive(archive_handle_t *ar_archive)
{
char magic[7];
- xread(ar_archive->src_fd, magic, 7);
- if (strncmp(magic, "!<arch>", 7) != 0) {
+ xread(ar_archive->src_fd, magic, AR_MAGIC_LEN);
+ if (strncmp(magic, AR_MAGIC, AR_MAGIC_LEN) != 0) {
bb_error_msg_and_die("invalid ar magic");
}
- ar_archive->offset += 7;
+ ar_archive->offset += AR_MAGIC_LEN;
while (get_header_ar(ar_archive) == EXIT_SUCCESS)
continue;
diff --git a/include/unarchive.h b/include/unarchive.h
index 8bfc92c..39891ff 100644
--- a/include/unarchive.h
+++ b/include/unarchive.h
@@ -73,6 +73,10 @@ typedef struct archive_handle_t {
/* Contains the handle to a sub archive */
struct archive_handle_t *dpkg__sub_archive;
#endif
+#if ENABLE_FEATURE_AR_CREATE
+ const char *ar_name;
+ struct archive_handle_t *ar_out;
+#endif
} archive_handle_t;
/* bits in ah_flags */
#define ARCHIVE_RESTORE_DATE (1 << 0)
--
1.6.3.3
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