Systemd/src/import/export.c
Lennart Poettering 4afd3348c7 tree-wide: expose "p"-suffix unref calls in public APIs to make gcc cleanup easy
GLIB has recently started to officially support the gcc cleanup
attribute in its public API, hence let's do the same for our APIs.

With this patch we'll define an xyz_unrefp() call for each public
xyz_unref() call, to make it easy to use inside a
__attribute__((cleanup())) expression. Then, all code is ported over to
make use of this.

The new calls are also documented in the man pages, with examples how to
use them (well, I only added docs where the _unref() call itself already
had docs, and the examples, only cover sd_bus_unrefp() and
sd_event_unrefp()).

This also renames sd_lldp_free() to sd_lldp_unref(), since that's how we
tend to call our destructors these days.

Note that this defines no public macro that wraps gcc's attribute and
makes it easier to use. While I think it's our duty in the library to
make our stuff easy to use, I figure it's not our duty to make gcc's own
features easy to use on its own. Most likely, client code which wants to
make use of this should define its own:

       #define _cleanup_(function) __attribute__((cleanup(function)))

Or similar, to make the gcc feature easier to use.

Making this logic public has the benefit that we can remove three header
files whose only purpose was to define these functions internally.

See #2008.
2015-11-27 19:19:36 +01:00

323 lines
11 KiB
C

/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2015 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <getopt.h>
#include "sd-event.h"
#include "alloc-util.h"
#include "export-raw.h"
#include "export-tar.h"
#include "fd-util.h"
#include "fs-util.h"
#include "hostname-util.h"
#include "import-util.h"
#include "machine-image.h"
#include "signal-util.h"
#include "string-util.h"
#include "verbs.h"
static ImportCompressType arg_compress = IMPORT_COMPRESS_UNKNOWN;
static void determine_compression_from_filename(const char *p) {
if (arg_compress != IMPORT_COMPRESS_UNKNOWN)
return;
if (!p) {
arg_compress = IMPORT_COMPRESS_UNCOMPRESSED;
return;
}
if (endswith(p, ".xz"))
arg_compress = IMPORT_COMPRESS_XZ;
else if (endswith(p, ".gz"))
arg_compress = IMPORT_COMPRESS_GZIP;
else if (endswith(p, ".bz2"))
arg_compress = IMPORT_COMPRESS_BZIP2;
else
arg_compress = IMPORT_COMPRESS_UNCOMPRESSED;
}
static int interrupt_signal_handler(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) {
log_notice("Transfer aborted.");
sd_event_exit(sd_event_source_get_event(s), EINTR);
return 0;
}
static void on_tar_finished(TarExport *export, int error, void *userdata) {
sd_event *event = userdata;
assert(export);
if (error == 0)
log_info("Operation completed successfully.");
sd_event_exit(event, abs(error));
}
static int export_tar(int argc, char *argv[], void *userdata) {
_cleanup_(tar_export_unrefp) TarExport *export = NULL;
_cleanup_(sd_event_unrefp) sd_event *event = NULL;
_cleanup_(image_unrefp) Image *image = NULL;
const char *path = NULL, *local = NULL;
_cleanup_close_ int open_fd = -1;
int r, fd;
if (machine_name_is_valid(argv[1])) {
r = image_find(argv[1], &image);
if (r < 0)
return log_error_errno(r, "Failed to look for machine %s: %m", argv[1]);
if (r == 0) {
log_error("Machine image %s not found.", argv[1]);
return -ENOENT;
}
local = image->path;
} else
local = argv[1];
if (argc >= 3)
path = argv[2];
if (isempty(path) || streq(path, "-"))
path = NULL;
determine_compression_from_filename(path);
if (path) {
open_fd = open(path, O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC|O_NOCTTY, 0666);
if (open_fd < 0)
return log_error_errno(errno, "Failed to open tar image for export: %m");
fd = open_fd;
log_info("Exporting '%s', saving to '%s' with compression '%s'.", local, path, import_compress_type_to_string(arg_compress));
} else {
_cleanup_free_ char *pretty = NULL;
fd = STDOUT_FILENO;
(void) readlink_malloc("/proc/self/fd/1", &pretty);
log_info("Exporting '%s', saving to '%s' with compression '%s'.", local, strna(pretty), import_compress_type_to_string(arg_compress));
}
r = sd_event_default(&event);
if (r < 0)
return log_error_errno(r, "Failed to allocate event loop: %m");
assert_se(sigprocmask_many(SIG_BLOCK, NULL, SIGTERM, SIGINT, -1) >= 0);
(void) sd_event_add_signal(event, NULL, SIGTERM, interrupt_signal_handler, NULL);
(void) sd_event_add_signal(event, NULL, SIGINT, interrupt_signal_handler, NULL);
r = tar_export_new(&export, event, on_tar_finished, event);
if (r < 0)
return log_error_errno(r, "Failed to allocate exporter: %m");
r = tar_export_start(export, local, fd, arg_compress);
if (r < 0)
return log_error_errno(r, "Failed to export image: %m");
r = sd_event_loop(event);
if (r < 0)
return log_error_errno(r, "Failed to run event loop: %m");
log_info("Exiting.");
return -r;
}
static void on_raw_finished(RawExport *export, int error, void *userdata) {
sd_event *event = userdata;
assert(export);
if (error == 0)
log_info("Operation completed successfully.");
sd_event_exit(event, abs(error));
}
static int export_raw(int argc, char *argv[], void *userdata) {
_cleanup_(raw_export_unrefp) RawExport *export = NULL;
_cleanup_(sd_event_unrefp) sd_event *event = NULL;
_cleanup_(image_unrefp) Image *image = NULL;
const char *path = NULL, *local = NULL;
_cleanup_close_ int open_fd = -1;
int r, fd;
if (machine_name_is_valid(argv[1])) {
r = image_find(argv[1], &image);
if (r < 0)
return log_error_errno(r, "Failed to look for machine %s: %m", argv[1]);
if (r == 0) {
log_error("Machine image %s not found.", argv[1]);
return -ENOENT;
}
local = image->path;
} else
local = argv[1];
if (argc >= 3)
path = argv[2];
if (isempty(path) || streq(path, "-"))
path = NULL;
determine_compression_from_filename(path);
if (path) {
open_fd = open(path, O_WRONLY|O_CREAT|O_TRUNC|O_CLOEXEC|O_NOCTTY, 0666);
if (open_fd < 0)
return log_error_errno(errno, "Failed to open raw image for export: %m");
fd = open_fd;
log_info("Exporting '%s', saving to '%s' with compression '%s'.", local, path, import_compress_type_to_string(arg_compress));
} else {
_cleanup_free_ char *pretty = NULL;
fd = STDOUT_FILENO;
(void) readlink_malloc("/proc/self/fd/1", &pretty);
log_info("Exporting '%s', saving to '%s' with compression '%s'.", local, strna(pretty), import_compress_type_to_string(arg_compress));
}
r = sd_event_default(&event);
if (r < 0)
return log_error_errno(r, "Failed to allocate event loop: %m");
assert_se(sigprocmask_many(SIG_BLOCK, NULL, SIGTERM, SIGINT, -1) >= 0);
(void) sd_event_add_signal(event, NULL, SIGTERM, interrupt_signal_handler, NULL);
(void) sd_event_add_signal(event, NULL, SIGINT, interrupt_signal_handler, NULL);
r = raw_export_new(&export, event, on_raw_finished, event);
if (r < 0)
return log_error_errno(r, "Failed to allocate exporter: %m");
r = raw_export_start(export, local, fd, arg_compress);
if (r < 0)
return log_error_errno(r, "Failed to export image: %m");
r = sd_event_loop(event);
if (r < 0)
return log_error_errno(r, "Failed to run event loop: %m");
log_info("Exiting.");
return -r;
}
static int help(int argc, char *argv[], void *userdata) {
printf("%s [OPTIONS...] {COMMAND} ...\n\n"
"Export container or virtual machine images.\n\n"
" -h --help Show this help\n"
" --version Show package version\n"
" --format=FORMAT Select format\n\n"
"Commands:\n"
" tar NAME [FILE] Export a TAR image\n"
" raw NAME [FILE] Export a RAW image\n",
program_invocation_short_name);
return 0;
}
static int parse_argv(int argc, char *argv[]) {
enum {
ARG_VERSION = 0x100,
ARG_FORMAT,
};
static const struct option options[] = {
{ "help", no_argument, NULL, 'h' },
{ "version", no_argument, NULL, ARG_VERSION },
{ "format", required_argument, NULL, ARG_FORMAT },
{}
};
int c;
assert(argc >= 0);
assert(argv);
while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0)
switch (c) {
case 'h':
return help(0, NULL, NULL);
case ARG_VERSION:
return version();
case ARG_FORMAT:
if (streq(optarg, "uncompressed"))
arg_compress = IMPORT_COMPRESS_UNCOMPRESSED;
else if (streq(optarg, "xz"))
arg_compress = IMPORT_COMPRESS_XZ;
else if (streq(optarg, "gzip"))
arg_compress = IMPORT_COMPRESS_GZIP;
else if (streq(optarg, "bzip2"))
arg_compress = IMPORT_COMPRESS_BZIP2;
else {
log_error("Unknown format: %s", optarg);
return -EINVAL;
}
break;
case '?':
return -EINVAL;
default:
assert_not_reached("Unhandled option");
}
return 1;
}
static int export_main(int argc, char *argv[]) {
static const Verb verbs[] = {
{ "help", VERB_ANY, VERB_ANY, 0, help },
{ "tar", 2, 3, 0, export_tar },
{ "raw", 2, 3, 0, export_raw },
{}
};
return dispatch_verb(argc, argv, verbs, NULL);
}
int main(int argc, char *argv[]) {
int r;
setlocale(LC_ALL, "");
log_parse_environment();
log_open();
r = parse_argv(argc, argv);
if (r <= 0)
goto finish;
(void) ignore_signals(SIGPIPE, -1);
r = export_main(argc, argv);
finish:
return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
}