bus: rework message handlers to always take an error argument

Message handler callbacks can be simplified drastically if the
dispatcher automatically replies to method calls if errors are returned.

Thus: add an sd_bus_error argument to all message handlers. When we
dispatch a message handler and it returns negative or a set sd_bus_error
we send this as message error back to the client. This means errors
returned by handlers by default are given back to clients instead of
rippling all the way up to the event loop, which is desirable to make
things robust.

As a side-effect we can now easily turn the SELinux checks into normal
function calls, since the method call dispatcher will generate the right
error replies automatically now.

Also, make sure we always pass the error structure to all property and
method handlers as last argument to follow the usual style of passing
variables for return values as last argument.

1 files changed, 26 insertions, 26 deletions

diff --git a/src/core/dbus-execute.c b/src/core/dbus-execute.c
index ca7ee5c10b..90556274d3 100644
--- a/src/core/dbus-execute.c
+++ b/src/core/dbus-execute.c
@@ -40,8 +40,8 @@ static int property_get_environment_files(
                 const char *interface,
                 const char *property,
                 sd_bus_message *reply,
-                sd_bus_error *error,
-                void *userdata) {
+                void *userdata,
+                sd_bus_error *error) {
 
         ExecContext *c = userdata;
         char **j;
@@ -72,8 +72,8 @@ static int property_get_rlimit(
                 const char *interface,
                 const char *property,
                 sd_bus_message *reply,
-                sd_bus_error *error,
-                void *userdata) {
+                void *userdata,
+                sd_bus_error *error) {
 
         struct rlimit *rl;
         uint64_t u;
@@ -106,8 +106,8 @@ static int property_get_oom_score_adjust(
                 const char *interface,
                 const char *property,
                 sd_bus_message *reply,
-                sd_bus_error *error,
-                void *userdata) {
+                void *userdata,
+                sd_bus_error *error) {
 
 
         ExecContext *c = userdata;
@@ -136,8 +136,8 @@ static int property_get_nice(
                 const char *interface,
                 const char *property,
                 sd_bus_message *reply,
-                sd_bus_error *error,
-                void *userdata) {
+                void *userdata,
+                sd_bus_error *error) {
 
 
         ExecContext *c = userdata;
@@ -165,8 +165,8 @@ static int property_get_ioprio(
                 const char *interface,
                 const char *property,
                 sd_bus_message *reply,
-                sd_bus_error *error,
-                void *userdata) {
+                void *userdata,
+                sd_bus_error *error) {
 
 
         ExecContext *c = userdata;
@@ -193,8 +193,8 @@ static int property_get_cpu_sched_policy(
                 const char *interface,
                 const char *property,
                 sd_bus_message *reply,
-                sd_bus_error *error,
-                void *userdata) {
+                void *userdata,
+                sd_bus_error *error) {
 
         ExecContext *c = userdata;
         int32_t n;
@@ -220,8 +220,8 @@ static int property_get_cpu_sched_priority(
                 const char *interface,
                 const char *property,
                 sd_bus_message *reply,
-                sd_bus_error *error,
-                void *userdata) {
+                void *userdata,
+                sd_bus_error *error) {
 
         ExecContext *c = userdata;
         int32_t n;
@@ -250,8 +250,8 @@ static int property_get_cpu_affinity(
                 const char *interface,
                 const char *property,
                 sd_bus_message *reply,
-                sd_bus_error *error,
-                void *userdata) {
+                void *userdata,
+                sd_bus_error *error) {
 
         ExecContext *c = userdata;
 
@@ -271,8 +271,8 @@ static int property_get_timer_slack_nsec(
                 const char *interface,
                 const char *property,
                 sd_bus_message *reply,
-                sd_bus_error *error,
-                void *userdata) {
+                void *userdata,
+                sd_bus_error *error) {
 
         ExecContext *c = userdata;
         uint64_t u;
@@ -295,8 +295,8 @@ static int property_get_capability_bounding_set(
                 const char *interface,
                 const char *property,
                 sd_bus_message *reply,
-                sd_bus_error *error,
-                void *userdata) {
+                void *userdata,
+                sd_bus_error *error) {
 
         ExecContext *c = userdata;
 
@@ -315,8 +315,8 @@ static int property_get_capabilities(
                 const char *interface,
                 const char *property,
                 sd_bus_message *reply,
-                sd_bus_error *error,
-                void *userdata) {
+                void *userdata,
+                sd_bus_error *error) {
 
         ExecContext *c = userdata;
         char *t = NULL;
@@ -349,8 +349,8 @@ static int property_get_syscall_filter(
                 const char *interface,
                 const char *property,
                 sd_bus_message *reply,
-                sd_bus_error *error,
-                void *userdata) {
+                void *userdata,
+                sd_bus_error *error) {
 
         ExecContext *c = userdata;
 
@@ -434,8 +434,8 @@ int bus_property_get_exec_command(
                 const char *interface,
                 const char *property,
                 sd_bus_message *reply,
-                sd_bus_error *error,
-                void *userdata) {
+                void *userdata,
+                sd_bus_error *ret_error) {
 
         ExecCommand *c = *(ExecCommand**) userdata;
         int r;