logind: open up most bus calls for unpriviliged processes, using PolicyKit

Also, allow clients to alter their own objects without any further
priviliges. i.e. this allows clients to kill and lock their own sessions
without involving PK.

1 files changed, 49 insertions, 10 deletions

diff --git a/src/login/logind-session-dbus.c b/src/login/logind-session-dbus.c
index 4e7edef52d..b119c8321b 100644
--- a/src/login/logind-session-dbus.c
+++ b/src/login/logind-session-dbus.c
@@ -180,7 +180,7 @@ static int property_get_idle_since_hint(
         return sd_bus_message_append(reply, "t", u);
 }
 
-static int method_terminate(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error) {
+int bus_session_method_terminate(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error) {
         Session *s = userdata;
         int r;
 
@@ -188,6 +188,19 @@ static int method_terminate(sd_bus *bus, sd_bus_message *message, void *userdata
         assert(message);
         assert(s);
 
+        r = bus_verify_polkit_async(
+                        message,
+                        CAP_KILL,
+                        "org.freedesktop.login1.manage",
+                        false,
+                        s->user->uid,
+                        &s->manager->polkit_registry,
+                        error);
+        if (r < 0)
+                return r;
+        if (r == 0)
+                return 1; /* Will call us back */
+
         r = session_stop(s, true);
         if (r < 0)
                 return r;
@@ -195,7 +208,7 @@ static int method_terminate(sd_bus *bus, sd_bus_message *message, void *userdata
         return sd_bus_reply_method_return(message, NULL);
 }
 
-static int method_activate(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error) {
+int bus_session_method_activate(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error) {
         Session *s = userdata;
         int r;
 
@@ -210,7 +223,7 @@ static int method_activate(sd_bus *bus, sd_bus_message *message, void *userdata,
         return sd_bus_reply_method_return(message, NULL);
 }
 
-static int method_lock(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error) {
+int bus_session_method_lock(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error) {
         Session *s = userdata;
         int r;
 
@@ -218,7 +231,20 @@ static int method_lock(sd_bus *bus, sd_bus_message *message, void *userdata, sd_
         assert(message);
         assert(s);
 
-        r = session_send_lock(s, streq(sd_bus_message_get_member(message), "Lock"));
+        r = bus_verify_polkit_async(
+                        message,
+                        CAP_SYS_ADMIN,
+                        "org.freedesktop.login1.lock-sessions",
+                        false,
+                        s->user->uid,
+                        &s->manager->polkit_registry,
+                        error);
+        if (r < 0)
+                return r;
+        if (r == 0)
+                return 1; /* Will call us back */
+
+        r = session_send_lock(s, strstr(sd_bus_message_get_member(message), "Lock"));
         if (r < 0)
                 return r;
 
@@ -255,7 +281,7 @@ static int method_set_idle_hint(sd_bus *bus, sd_bus_message *message, void *user
         return sd_bus_reply_method_return(message, NULL);
 }
 
-static int method_kill(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error) {
+int bus_session_method_kill(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error) {
         Session *s = userdata;
         const char *swho;
         int32_t signo;
@@ -281,6 +307,19 @@ static int method_kill(sd_bus *bus, sd_bus_message *message, void *userdata, sd_
         if (signo <= 0 || signo >= _NSIG)
                 return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid signal %i", signo);
 
+        r = bus_verify_polkit_async(
+                        message,
+                        CAP_KILL,
+                        "org.freedesktop.login1.manage",
+                        false,
+                        s->user->uid,
+                        &s->manager->polkit_registry,
+                        error);
+        if (r < 0)
+                return r;
+        if (r == 0)
+                return 1; /* Will call us back */
+
         r = session_kill(s, who, signo);
         if (r < 0)
                 return r;
@@ -456,12 +495,12 @@ const sd_bus_vtable session_vtable[] = {
         SD_BUS_PROPERTY("IdleSinceHint", "t", property_get_idle_since_hint, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
         SD_BUS_PROPERTY("IdleSinceHintMonotonic", "t", property_get_idle_since_hint, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
 
-        SD_BUS_METHOD("Terminate", NULL, NULL, method_terminate, SD_BUS_VTABLE_CAPABILITY(CAP_KILL)),
-        SD_BUS_METHOD("Activate", NULL, NULL, method_activate, SD_BUS_VTABLE_UNPRIVILEGED),
-        SD_BUS_METHOD("Lock", NULL, NULL, method_lock, 0),
-        SD_BUS_METHOD("Unlock", NULL, NULL, method_lock, 0),
+        SD_BUS_METHOD("Terminate", NULL, NULL, bus_session_method_terminate, SD_BUS_VTABLE_UNPRIVILEGED),
+        SD_BUS_METHOD("Activate", NULL, NULL, bus_session_method_activate, SD_BUS_VTABLE_UNPRIVILEGED),
+        SD_BUS_METHOD("Lock", NULL, NULL, bus_session_method_lock, SD_BUS_VTABLE_UNPRIVILEGED),
+        SD_BUS_METHOD("Unlock", NULL, NULL, bus_session_method_lock, SD_BUS_VTABLE_UNPRIVILEGED),
         SD_BUS_METHOD("SetIdleHint", "b", NULL, method_set_idle_hint, SD_BUS_VTABLE_UNPRIVILEGED),
-        SD_BUS_METHOD("Kill", "si", NULL, method_kill, SD_BUS_VTABLE_CAPABILITY(CAP_KILL)),
+        SD_BUS_METHOD("Kill", "si", NULL, bus_session_method_kill, SD_BUS_VTABLE_UNPRIVILEGED),
         SD_BUS_METHOD("TakeControl", "b", NULL, method_take_control, SD_BUS_VTABLE_UNPRIVILEGED),
         SD_BUS_METHOD("ReleaseControl", NULL, NULL, method_release_control, SD_BUS_VTABLE_UNPRIVILEGED),
         SD_BUS_METHOD("TakeDevice", "uu", "hb", method_take_device, SD_BUS_VTABLE_UNPRIVILEGED),