bus: keep kernel bus fd around during entire life-time of bus

[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 29487cbd317904f545b27b570c7ea5712695b55c..08ab202baf8301b1eca4c280d2fa52a1e5ba802a 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"
@@ -42,6 +43,18 @@
 
 static int bus_poll(sd_bus *bus, bool need_more, uint64_t timeout_usec);
 
+static void bus_close_fds(sd_bus *b) {
+        assert(b);
+
+        if (b->input_fd >= 0)
+                close_nointr_nofail(b->input_fd);
+
+        if (b->output_fd >= 0 && b->output_fd != b->input_fd)
+                close_nointr_nofail(b->output_fd);
+
+        b->input_fd = b->output_fd = -1;
+}
+
 static void bus_free(sd_bus *b) {
         struct filter_callback *f;
         struct object_callback *c;
@@ -49,12 +62,13 @@ static void bus_free(sd_bus *b) {
 
         assert(b);
 
-        sd_bus_close(b);
+        bus_close_fds(b);
 
         free(b->rbuffer);
         free(b->unique_name);
         free(b->auth_buffer);
         free(b->address);
+        free(b->kernel);
 
         free(b->exec_path);
         strv_free(b->exec_argv);
@@ -84,9 +98,10 @@ 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);
 }
 
@@ -100,7 +115,7 @@ 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;
@@ -226,18 +241,18 @@ 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;
@@ -279,7 +294,7 @@ 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;
         }
@@ -840,7 +855,7 @@ 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)
@@ -878,13 +893,13 @@ 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;
@@ -919,21 +934,27 @@ void sd_bus_close(sd_bus *bus) {
         if (!bus)
                 return;
 
-        if (bus->input_fd >= 0)
-                close_nointr_nofail(bus->input_fd);
-        if (bus->output_fd >= 0 && bus->output_fd != bus->input_fd)
-                close_nointr_nofail(bus->output_fd);
+        if (bus->state != BUS_CLOSED)
+                return;
 
-        bus->input_fd = bus->output_fd = -1;
+        bus->state = BUS_CLOSED;
+
+        if (!bus->is_kernel)
+                bus_close_fds(bus);
+
+        /* We'll leave the fd open in case this is a kernel bus, since
+         * there might still be memblocks around that reference this
+         * bus, and they might need to invoke the
+         * KDBUS_CMD_MSG_RELEASE ioctl on the fd when they are
+         * freed. */
 }
 
 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;
 }
 
@@ -941,10 +962,7 @@ 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;
@@ -954,7 +972,7 @@ int sd_bus_is_open(sd_bus *bus) {
         if (!bus)
                 return -EINVAL;
 
-        return bus->state != BUS_UNSET && bus->input_fd >= 0;
+        return BUS_IS_OPEN(bus->state);
 }
 
 int sd_bus_can_send(sd_bus *bus, char type) {
@@ -962,7 +980,7 @@ int sd_bus_can_send(sd_bus *bus, char type) {
 
         if (!bus)
                 return -EINVAL;
-        if (bus->output_fd < 0)
+        if (bus->state == BUS_UNSET)
                 return -ENOTCONN;
 
         if (type == SD_BUS_TYPE_UNIX_FD) {
@@ -1013,9 +1031,6 @@ static int dispatch_wqueue(sd_bus *bus) {
         assert(bus);
         assert(bus->state == BUS_RUNNING || bus->state == BUS_HELLO);
 
-        if (bus->output_fd < 0)
-                return -ENOTCONN;
-
         while (bus->wqueue_size > 0) {
 
                 if (bus->is_kernel)
@@ -1060,9 +1075,6 @@ static int dispatch_rqueue(sd_bus *bus, sd_bus_message **m) {
         assert(m);
         assert(bus->state == BUS_RUNNING || bus->state == BUS_HELLO);
 
-        if (bus->input_fd < 0)
-                return -ENOTCONN;
-
         if (bus->rqueue_size > 0) {
                 /* Dispatch a queued message */
 
@@ -1098,9 +1110,7 @@ int sd_bus_send(sd_bus *bus, sd_bus_message *m, uint64_t *serial) {
 
         if (!bus)
                 return -EINVAL;
-        if (bus->state == BUS_UNSET)
-                return -ENOTCONN;
-        if (bus->output_fd < 0)
+        if (!BUS_IS_OPEN(bus->state))
                 return -ENOTCONN;
         if (!m)
                 return -EINVAL;
@@ -1211,9 +1221,7 @@ int sd_bus_send_with_reply(
 
         if (!bus)
                 return -EINVAL;
-        if (bus->state == BUS_UNSET)
-                return -ENOTCONN;
-        if (bus->output_fd < 0)
+        if (!BUS_IS_OPEN(bus->state))
                 return -ENOTCONN;
         if (!m)
                 return -EINVAL;
@@ -1295,11 +1303,8 @@ int bus_ensure_running(sd_bus *bus) {
 
         assert(bus);
 
-        if (bus->input_fd < 0)
-                return -ENOTCONN;
-        if (bus->state == BUS_UNSET)
+        if (bus->state == BUS_UNSET || bus->state == BUS_CLOSED)
                 return -ENOTCONN;
-
         if (bus->state == BUS_RUNNING)
                 return 1;
 
@@ -1332,9 +1337,7 @@ int sd_bus_send_with_reply_and_block(
 
         if (!bus)
                 return -EINVAL;
-        if (bus->output_fd < 0)
-                return -ENOTCONN;
-        if (bus->state == BUS_UNSET)
+        if (!BUS_IS_OPEN(bus->state))
                 return -ENOTCONN;
         if (!m)
                 return -EINVAL;
@@ -1450,7 +1453,7 @@ int sd_bus_send_with_reply_and_block(
 int sd_bus_get_fd(sd_bus *bus) {
         if (!bus)
                 return -EINVAL;
-        if (bus->input_fd < 0)
+        if (!BUS_IS_OPEN(bus->state))
                 return -ENOTCONN;
         if (bus->input_fd != bus->output_fd)
                 return -EPERM;
@@ -1463,9 +1466,7 @@ int sd_bus_get_events(sd_bus *bus) {
 
         if (!bus)
                 return -EINVAL;
-        if (bus->state == BUS_UNSET)
-                return -ENOTCONN;
-        if (bus->input_fd < 0)
+        if (!BUS_IS_OPEN(bus->state))
                 return -ENOTCONN;
 
         if (bus->state == BUS_OPENING)
@@ -1494,9 +1495,7 @@ int sd_bus_get_timeout(sd_bus *bus, uint64_t *timeout_usec) {
                 return -EINVAL;
         if (!timeout_usec)
                 return -EINVAL;
-        if (bus->state == BUS_UNSET)
-                return -ENOTCONN;
-        if (bus->input_fd < 0)
+        if (!BUS_IS_OPEN(bus->state))
                 return -ENOTCONN;
 
         if (bus->state == BUS_AUTHENTICATING) {
@@ -1520,6 +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;
@@ -1534,10 +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;
@@ -1583,7 +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;
@@ -1610,7 +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;
 
@@ -1630,7 +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;
 
@@ -1719,7 +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;
 
@@ -1745,7 +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;
 
@@ -1823,13 +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);
@@ -1929,6 +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;
@@ -1968,8 +1992,6 @@ int sd_bus_process(sd_bus *bus, sd_bus_message **ret) {
 
         if (!bus)
                 return -EINVAL;
-        if (bus->input_fd < 0)
-                return -ENOTCONN;
 
         /* We don't allow recursively invoking sd_bus_process(). */
         if (bus->processing)
@@ -1978,6 +2000,7 @@ int sd_bus_process(sd_bus *bus, sd_bus_message **ret) {
         switch (bus->state) {
 
         case BUS_UNSET:
+        case BUS_CLOSED:
                 return -ENOTCONN;
 
         case BUS_OPENING:
@@ -2018,7 +2041,7 @@ static int bus_poll(sd_bus *bus, bool need_more, uint64_t timeout_usec) {
 
         assert(bus);
 
-        if (bus->input_fd < 0)
+        if (!BUS_IS_OPEN(bus->state))
                 return -ENOTCONN;
 
         e = sd_bus_get_events(bus);
@@ -2064,9 +2087,7 @@ int sd_bus_wait(sd_bus *bus, uint64_t timeout_usec) {
 
         if (!bus)
                 return -EINVAL;
-        if (bus->state == BUS_UNSET)
-                return -ENOTCONN;
-        if (bus->input_fd < 0)
+        if (!BUS_IS_OPEN(bus->state))
                 return -ENOTCONN;
         if (bus->rqueue_size > 0)
                 return 0;
@@ -2079,9 +2100,7 @@ int sd_bus_flush(sd_bus *bus) {
 
         if (!bus)
                 return -EINVAL;
-        if (bus->state == BUS_UNSET)
-                return -ENOTCONN;
-        if (bus->output_fd < 0)
+        if (!BUS_IS_OPEN(bus->state))
                 return -ENOTCONN;
 
         r = bus_ensure_running(bus);