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/***
This file is part of systemd.
Copyright 2014 Tom Gundersen <teg@jklm.no>
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 <systemd/sd-daemon.h>
#include <systemd/sd-event.h>
#include "systemd-basic/capability-util.h"
#include "systemd-basic/mkdir.h"
#include "systemd-basic/selinux-util.h"
#include "systemd-basic/signal-util.h"
#include "systemd-basic/user-util.h"
#include "resolved-conf.h"
#include "resolved-manager.h"
#include "resolved-resolv-conf.h"
int main(int argc, char *argv[]) {
_cleanup_(manager_freep) Manager *m = NULL;
const char *user = "systemd-resolve";
uid_t uid;
gid_t gid;
int r;
log_set_target(LOG_TARGET_AUTO);
log_parse_environment();
log_open();
if (argc != 1) {
log_error("This program takes no arguments.");
r = -EINVAL;
goto finish;
}
umask(0022);
r = mac_selinux_init();
if (r < 0) {
log_error_errno(r, "SELinux setup failed: %m");
goto finish;
}
r = get_user_creds(&user, &uid, &gid, NULL, NULL);
if (r < 0) {
log_error_errno(r, "Cannot resolve user name %s: %m", user);
goto finish;
}
/* Always create the directory where resolv.conf will live */
r = mkdir_safe_label("/run/systemd/resolve", 0755, uid, gid);
if (r < 0) {
log_error_errno(r, "Could not create runtime directory: %m");
goto finish;
}
/* Drop privileges, but keep three caps. Note that we drop those too, later on (see below) */
r = drop_privileges(uid, gid,
(UINT64_C(1) << CAP_NET_RAW)| /* needed for SO_BINDTODEVICE */
(UINT64_C(1) << CAP_NET_BIND_SERVICE)| /* needed to bind on port 53 */
(UINT64_C(1) << CAP_SETPCAP) /* needed in order to drop the caps later */);
if (r < 0)
goto finish;
assert_se(sigprocmask_many(SIG_BLOCK, NULL, SIGTERM, SIGINT, SIGUSR1, SIGUSR2, -1) >= 0);
r = manager_new(&m);
if (r < 0) {
log_error_errno(r, "Could not create manager: %m");
goto finish;
}
r = manager_start(m);
if (r < 0) {
log_error_errno(r, "Failed to start manager: %m");
goto finish;
}
/* Write finish default resolv.conf to avoid a dangling symlink */
(void) manager_write_resolv_conf(m);
/* Let's drop the remaining caps now */
r = capability_bounding_set_drop(0, true);
if (r < 0) {
log_error_errno(r, "Failed to drop remaining caps: %m");
goto finish;
}
sd_notify(false,
"READY=1\n"
"STATUS=Processing requests...");
r = sd_event_loop(m->event);
if (r < 0) {
log_error_errno(r, "Event loop failed: %m");
goto finish;
}
sd_event_get_exit_code(m->event, &r);
finish:
sd_notify(false,
"STOPPING=1\n"
"STATUS=Shutting down...");
return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
}
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