resolved: respond to local resolver requests on 127.0.0.53:53

[thirdparty/systemd.git] / src / resolve / resolved.c

diff --git a/src/resolve/resolved.c b/src/resolve/resolved.c
index e283d8a7496800f59f93f6d92dda9158380875cd..deb75f9ae54842c25c716a3bbfea058a8a3d14fb 100644 (file)
--- a/src/resolve/resolved.c
+++ b/src/resolve/resolved.c
@@ -1,5 +1,3 @@
-/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
-
 /***
   This file is part of systemd.
 
@@ -19,15 +17,17 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
-#include "sd-event.h"
 #include "sd-daemon.h"
+#include "sd-event.h"
+
+#include "capability-util.h"
 #include "mkdir.h"
-#include "capability.h"
+#include "resolved-conf.h"
+#include "resolved-manager.h"
+#include "resolved-resolv-conf.h"
 #include "selinux-util.h"
 #include "signal-util.h"
-
-#include "resolved-manager.h"
-#include "resolved-conf.h"
+#include "user-util.h"
 
 int main(int argc, char *argv[]) {
         _cleanup_(manager_freep) Manager *m = NULL;
@@ -48,7 +48,7 @@ int main(int argc, char *argv[]) {
 
         umask(0022);
 
-        r = mac_selinux_init(NULL);
+        r = mac_selinux_init();
         if (r < 0) {
                 log_error_errno(r, "SELinux setup failed: %m");
                 goto finish;
@@ -67,11 +67,15 @@ int main(int argc, char *argv[]) {
                 goto finish;
         }
 
-        r = drop_privileges(uid, gid, 0);
+        /* 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, SIGTERM, SIGINT, -1) == 0);
+        assert_se(sigprocmask_many(SIG_BLOCK, NULL, SIGTERM, SIGINT, SIGUSR1, SIGUSR2, -1) >= 0);
 
         r = manager_new(&m);
         if (r < 0) {
@@ -79,21 +83,21 @@ int main(int argc, char *argv[]) {
                 goto finish;
         }
 
-        r = manager_parse_config_file(m);
-        if (r < 0)
-                log_warning_errno(r, "Failed to parse configuration file: %m");
-
         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 */
-        r = manager_write_resolv_conf(m);
-        if (r < 0)
-                log_warning_errno(r, "Could not create resolv.conf: %m");
+        /* 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"