bus: make bus ref counting atomic

[elogind.git] / src / libsystemd-bus / sd-bus.c

diff --git a/src/libsystemd-bus/sd-bus.c b/src/libsystemd-bus/sd-bus.c
index 2424ee14465bb69737f8b4281ec226c6839672fa..4a081778ace4f9872735b337077b984084e678ad 100644 (file)
--- a/src/libsystemd-bus/sd-bus.c
+++ b/src/libsystemd-bus/sd-bus.c
@@ -31,6 +31,7 @@
 #include "macro.h"
 #include "strv.h"
 #include "set.h"
+#include "missing.h"
 
 #include "sd-bus.h"
 #include "bus-internal.h"
@@ -85,9 +86,10 @@ static void bus_free(sd_bus *b) {
         }
 
         hashmap_free(b->object_callbacks);
-
         bus_match_free(&b->match_callbacks);
 
+        bus_kernel_flush_memfd(b);
+
         free(b);
 }
 
@@ -101,7 +103,7 @@ int sd_bus_new(sd_bus **ret) {
         if (!r)
                 return -ENOMEM;
 
-        r->n_ref = 1;
+        r->n_ref = REFCNT_INIT;
         r->input_fd = r->output_fd = -1;
         r->message_version = 1;
         r->negotiate_fds = true;
@@ -227,18 +229,18 @@ int sd_bus_set_anonymous(sd_bus *bus, int b) {
         return 0;
 }
 
-static int hello_callback(sd_bus *bus, int error, sd_bus_message *reply, void *userdata) {
+static int hello_callback(sd_bus *bus, sd_bus_message *reply, void *userdata) {
         const char *s;
         int r;
 
         assert(bus);
         assert(bus->state == BUS_HELLO);
-
-        if (error != 0)
-                return -error;
-
         assert(reply);
 
+        r = bus_message_to_errno(reply);
+        if (r < 0)
+                return r;
+
         r = sd_bus_message_read(reply, "s", &s);
         if (r < 0)
                 return r;
@@ -280,7 +282,7 @@ static int bus_send_hello(sd_bus *bus) {
 int bus_start_running(sd_bus *bus) {
         assert(bus);
 
-        if (bus->bus_client) {
+        if (bus->bus_client && !bus->is_kernel) {
                 bus->state = BUS_HELLO;
                 return 1;
         }
@@ -841,7 +843,7 @@ int sd_bus_open_system(sd_bus **ret) {
         if (r < 0)
                 return r;
 
-        e = getenv("DBUS_SYSTEM_BUS_ADDRESS");
+        e = secure_getenv("DBUS_SYSTEM_BUS_ADDRESS");
         if (e) {
                 r = sd_bus_set_address(b, e);
                 if (r < 0)
@@ -879,13 +881,13 @@ int sd_bus_open_user(sd_bus **ret) {
         if (r < 0)
                 return r;
 
-        e = getenv("DBUS_SESSION_BUS_ADDRESS");
+        e = secure_getenv("DBUS_SESSION_BUS_ADDRESS");
         if (e) {
                 r = sd_bus_set_address(b, e);
                 if (r < 0)
                         goto fail;
         } else {
-                e = getenv("XDG_RUNTIME_DIR");
+                e = secure_getenv("XDG_RUNTIME_DIR");
                 if (!e) {
                         r = -ENOENT;
                         goto fail;
@@ -932,9 +934,8 @@ sd_bus *sd_bus_ref(sd_bus *bus) {
         if (!bus)
                 return NULL;
 
-        assert(bus->n_ref > 0);
+        assert_se(REFCNT_INC(bus->n_ref) >= 2);
 
-        bus->n_ref++;
         return bus;
 }
 
@@ -942,10 +943,7 @@ sd_bus *sd_bus_unref(sd_bus *bus) {
         if (!bus)
                 return NULL;
 
-        assert(bus->n_ref > 0);
-        bus->n_ref--;
-
-        if (bus->n_ref <= 0)
+        if (REFCNT_DEC(bus->n_ref) <= 0)
                 bus_free(bus);
 
         return NULL;
@@ -1521,6 +1519,7 @@ int sd_bus_get_timeout(sd_bus *bus, uint64_t *timeout_usec) {
 }
 
 static int process_timeout(sd_bus *bus) {
+        _cleanup_bus_message_unref_ sd_bus_message* m = NULL;
         struct reply_callback *c;
         usec_t n;
         int r;
@@ -1535,10 +1534,18 @@ static int process_timeout(sd_bus *bus) {
         if (c->timeout > n)
                 return 0;
 
+        r = bus_message_new_synthetic_error(
+                        bus,
+                        c->serial,
+                        &SD_BUS_ERROR_MAKE("org.freedesktop.DBus.Error.Timeout", "Timed out"),
+                        &m);
+        if (r < 0)
+                return r;
+
         assert_se(prioq_pop(bus->reply_callbacks_prioq) == c);
         hashmap_remove(bus->reply_callbacks, &c->serial);
 
-        r = c->callback(bus, ETIMEDOUT, NULL, c->userdata);
+        r = c->callback(bus, m, c->userdata);
         free(c);
 
         return r < 0 ? r : 1;
@@ -1584,7 +1591,11 @@ static int process_reply(sd_bus *bus, sd_bus_message *m) {
         if (c->timeout != 0)
                 prioq_remove(bus->reply_callbacks_prioq, c, &c->prioq_idx);
 
-        r = c->callback(bus, 0, m, c->userdata);
+        r = sd_bus_message_rewind(m, true);
+        if (r < 0)
+                return r;
+
+        r = c->callback(bus, m, c->userdata);
         free(c);
 
         return r;
@@ -1611,7 +1622,11 @@ static int process_filter(sd_bus *bus, sd_bus_message *m) {
 
                         l->last_iteration = bus->iteration_counter;
 
-                        r = l->callback(bus, 0, m, l->userdata);
+                        r = sd_bus_message_rewind(m, true);
+                        if (r < 0)
+                                return r;
+
+                        r = l->callback(bus, m, l->userdata);
                         if (r != 0)
                                 return r;
 
@@ -1631,7 +1646,7 @@ static int process_match(sd_bus *bus, sd_bus_message *m) {
         do {
                 bus->match_callbacks_modified = false;
 
-                r = bus_match_run(bus, &bus->match_callbacks, 0, m);
+                r = bus_match_run(bus, &bus->match_callbacks, m);
                 if (r != 0)
                         return r;
 
@@ -1720,7 +1735,11 @@ static int process_object(sd_bus *bus, sd_bus_message *m) {
 
                         c->last_iteration = bus->iteration_counter;
 
-                        r = c->callback(bus, 0, m, c->userdata);
+                        r = sd_bus_message_rewind(m, true);
+                        if (r < 0)
+                                return r;
+
+                        r = c->callback(bus, m, c->userdata);
                         if (r != 0)
                                 return r;
 
@@ -1746,7 +1765,11 @@ static int process_object(sd_bus *bus, sd_bus_message *m) {
 
                                 c->last_iteration = bus->iteration_counter;
 
-                                r = c->callback(bus, 0, m, c->userdata);
+                                r = sd_bus_message_rewind(m, true);
+                                if (r < 0)
+                                        return r;
+
+                                r = c->callback(bus, m, c->userdata);
                                 if (r != 0)
                                         return r;
 
@@ -1824,13 +1847,9 @@ static int process_introspect(sd_bus *bus, sd_bus_message *m) {
                 if (p)
                         *p = 0;
 
-                r = set_put(s, a);
-                if (r < 0) {
-                        free(a);
-
-                        if (r != -EEXIST)
-                                return r;
-                }
+                r = set_consume(s, a);
+                if (r < 0 && r != -EEXIST)
+                        return r;
         }
 
         f = open_memstream(&introspection, &size);
@@ -1930,6 +1949,10 @@ static int process_running(sd_bus *bus, sd_bus_message **ret) {
                 goto null_message;
 
         if (ret) {
+                r = sd_bus_message_rewind(m, true);
+                if (r < 0)
+                        return r;
+
                 *ret = m;
                 m = NULL;
                 return 1;