chiark / gitweb /
bus: fix memory leak when kdbus is not enabled
[elogind.git] / src / libsystemd / sd-bus / sd-bus.c
index a8295b2778b7b78b86b70abf407fd063af8b09ea..ca7c428a31628d043d94a83e3705d8db6689a919 100644 (file)
@@ -35,6 +35,8 @@
 #include "set.h"
 #include "missing.h"
 #include "def.h"
+#include "cgroup-util.h"
+#include "bus-label.h"
 
 #include "sd-bus.h"
 #include "bus-internal.h"
@@ -49,6 +51,7 @@
 #include "bus-util.h"
 #include "bus-container.h"
 #include "bus-protocol.h"
+#include "bus-track.h"
 
 static int bus_poll(sd_bus *bus, bool need_more, uint64_t timeout_usec);
 static int attach_io_events(sd_bus *b);
@@ -106,21 +109,21 @@ static void bus_node_destroy(sd_bus *b, struct node *n) {
 }
 
 static void bus_reset_queues(sd_bus *b) {
-        unsigned i;
-
         assert(b);
 
-        for (i = 0; i < b->rqueue_size; i++)
-                sd_bus_message_unref(b->rqueue[i]);
+        while (b->rqueue_size > 0)
+                sd_bus_message_unref(b->rqueue[--b->rqueue_size]);
+
         free(b->rqueue);
+        b->rqueue = NULL;
+        b->rqueue_allocated = 0;
 
-        for (i = 0; i < b->wqueue_size; i++)
-                sd_bus_message_unref(b->wqueue[i]);
-        free(b->wqueue);
+        while (b->wqueue_size > 0)
+                sd_bus_message_unref(b->wqueue[--b->wqueue_size]);
 
-        b->rqueue = b->wqueue = NULL;
-        b->rqueue_allocated = b->wqueue_allocated = 0;
-        b->rqueue_size = b->wqueue_size = 0;
+        free(b->wqueue);
+        b->wqueue = NULL;
+        b->wqueue_allocated = 0;
 }
 
 static void bus_free(sd_bus *b) {
@@ -129,8 +132,13 @@ static void bus_free(sd_bus *b) {
 
         assert(b);
 
+        assert(!b->track_queue);
+
         sd_bus_detach_event(b);
 
+        if (b->default_bus_ptr)
+                *b->default_bus_ptr = NULL;
+
         bus_close_fds(b);
 
         if (b->kdbus_buffer)
@@ -395,11 +403,11 @@ static int bus_send_hello(sd_bus *bus) {
 
         r = sd_bus_message_new_method_call(
                         bus,
+                        &m,
                         "org.freedesktop.DBus",
                         "/org/freedesktop/DBus",
                         "org.freedesktop.DBus",
-                        "Hello",
-                        &m);
+                        "Hello");
         if (r < 0)
                 return r;
 
@@ -790,7 +798,7 @@ static int parse_container_unix_address(sd_bus *b, const char **p, char **guid)
 
         b->sockaddr.un.sun_family = AF_UNIX;
         strncpy(b->sockaddr.un.sun_path, "/var/run/dbus/system_bus_socket", sizeof(b->sockaddr.un.sun_path));
-        b->sockaddr_size = offsetof(struct sockaddr_un, sun_path) + sizeof("/var/run/dbus/system_bus_socket") - 1;
+        b->sockaddr_size = offsetof(struct sockaddr_un, sun_path) + strlen("/var/run/dbus/system_bus_socket");
 
         return 0;
 }
@@ -1052,6 +1060,60 @@ _public_ int sd_bus_start(sd_bus *bus) {
         return bus_send_hello(bus);
 }
 
+_public_ int sd_bus_open(sd_bus **ret) {
+        const char *e;
+        sd_bus *b;
+        int r;
+
+        assert_return(ret, -EINVAL);
+
+        /* Let's connect to the starter bus if it is set, and
+         * otherwise to the bus that is appropropriate for the scope
+         * we are running in */
+
+        e = secure_getenv("DBUS_STARTER_BUS_TYPE");
+        if (e) {
+                if (streq(e, "system"))
+                        return sd_bus_open_system(ret);
+                else if (streq(e, "session") || streq(e, "user"))
+                        return sd_bus_open_user(ret);
+        }
+
+        e = secure_getenv("DBUS_STARTER_ADDRESS");
+        if (!e) {
+                if (cg_pid_get_owner_uid(0, NULL) >= 0)
+                        return sd_bus_open_user(ret);
+                else
+                        return sd_bus_open_system(ret);
+        }
+
+        r = sd_bus_new(&b);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_set_address(b, e);
+        if (r < 0)
+                goto fail;
+
+        b->bus_client = true;
+
+        /* We don't know whether the bus is trusted or not, so better
+         * be safe, and authenticate everything */
+        b->trusted = false;
+        b->attach_flags |= KDBUS_ATTACH_CAPS | KDBUS_ATTACH_CREDS;
+
+        r = sd_bus_start(b);
+        if (r < 0)
+                goto fail;
+
+        *ret = b;
+        return 0;
+
+fail:
+        bus_free(b);
+        return r;
+}
+
 _public_ int sd_bus_open_system(sd_bus **ret) {
         const char *e;
         sd_bus *b;
@@ -1127,7 +1189,8 @@ _public_ int sd_bus_open_user(sd_bus **ret) {
 #ifdef ENABLE_KDBUS
                         asprintf(&b->address, KERNEL_USER_BUS_FMT, (unsigned long) getuid());
 #else
-                        return -ECONNREFUSED;
+                        r = -ECONNREFUSED;
+                        goto fail;
 #endif
                 }
 
@@ -1156,7 +1219,7 @@ fail:
         return r;
 }
 
-_public_ int sd_bus_open_system_remote(const char *host, sd_bus **ret) {
+_public_ int sd_bus_open_system_remote(sd_bus **ret, const char *host) {
         _cleanup_free_ char *e = NULL;
         char *p = NULL;
         sd_bus *bus;
@@ -1192,7 +1255,7 @@ _public_ int sd_bus_open_system_remote(const char *host, sd_bus **ret) {
         return 0;
 }
 
-_public_ int sd_bus_open_system_container(const char *machine, sd_bus **ret) {
+_public_ int sd_bus_open_system_container(sd_bus **ret, const char *machine) {
         _cleanup_free_ char *e = NULL;
         sd_bus *bus;
         char *p;
@@ -1285,21 +1348,37 @@ _public_ sd_bus *sd_bus_unref(sd_bus *bus) {
         if (!bus)
                 return NULL;
 
-        i = REFCNT_DEC(bus->n_ref);
-        if (i != bus->rqueue_size + bus->wqueue_size)
-                return NULL;
+        if (REFCNT_GET(bus->n_ref) == bus->rqueue_size + bus->wqueue_size + 1) {
+                bool q = true;
 
-        for (i = 0; i < bus->rqueue_size; i++)
-                if (bus->rqueue[i]->n_ref > 1)
-                        return NULL;
+                for (i = 0; i < bus->rqueue_size; i++)
+                        if (bus->rqueue[i]->n_ref > 1) {
+                                q = false;
+                                break;
+                        }
+
+                if (q) {
+                        for (i = 0; i < bus->wqueue_size; i++)
+                                if (bus->wqueue[i]->n_ref > 1) {
+                                        q = false;
+                                        break;
+                                }
+                }
 
-        for (i = 0; i < bus->wqueue_size; i++)
-                if (bus->wqueue[i]->n_ref > 1)
-                        return NULL;
+                /* We are the only holders on the messages, and the
+                 * messages are the only holders on us, so let's drop
+                 * the messages and thus implicitly also kill our own
+                 * last references */
 
-        /* we are the only holders on the messages */
-        bus_free(bus);
+                if (q)
+                        bus_reset_queues(bus);
+        }
+
+        i = REFCNT_DEC(bus->n_ref);
+        if (i > 0)
+                return NULL;
 
+        bus_free(bus);
         return NULL;
 }
 
@@ -1458,11 +1537,11 @@ static int dispatch_wqueue(sd_bus *bus) {
         return ret;
 }
 
-static int bus_read_message(sd_bus *bus) {
+static int bus_read_message(sd_bus *bus, bool hint_priority, int64_t priority) {
         assert(bus);
 
         if (bus->is_kernel)
-                return bus_kernel_read_message(bus);
+                return bus_kernel_read_message(bus, hint_priority, priority);
         else
                 return bus_socket_read_message(bus);
 }
@@ -1479,13 +1558,17 @@ int bus_rqueue_make_room(sd_bus *bus) {
         return 0;
 }
 
-static int dispatch_rqueue(sd_bus *bus, sd_bus_message **m) {
+static int dispatch_rqueue(sd_bus *bus, bool hint_priority, int64_t priority, sd_bus_message **m) {
         int r, ret = 0;
 
         assert(bus);
         assert(m);
         assert(bus->state == BUS_RUNNING || bus->state == BUS_HELLO);
 
+        /* Note that the priority logic is only available on kdbus,
+         * where the rqueue is unused. We check the rqueue here
+         * anyway, because it's simple... */
+
         for (;;) {
                 if (bus->rqueue_size > 0) {
                         /* Dispatch a queued message */
@@ -1497,7 +1580,7 @@ static int dispatch_rqueue(sd_bus *bus, sd_bus_message **m) {
                 }
 
                 /* Try to read a new message */
-                r = bus_read_message(bus);
+                r = bus_read_message(bus, hint_priority, priority);
                 if (r < 0)
                         return r;
                 if (r == 0)
@@ -1837,7 +1920,7 @@ _public_ int sd_bus_call(
                         i++;
                 }
 
-                r = bus_read_message(bus);
+                r = bus_read_message(bus, false, 0);
                 if (r < 0) {
                         if (r == -ENOTCONN || r == -ECONNRESET || r == -EPIPE || r == -ESHUTDOWN) {
                                 bus_enter_closing(bus);
@@ -1921,6 +2004,11 @@ _public_ int sd_bus_get_timeout(sd_bus *bus, uint64_t *timeout_usec) {
         assert_return(BUS_IS_OPEN(bus->state) || bus->state == BUS_CLOSING, -ENOTCONN);
         assert_return(!bus_pid_changed(bus), -ECHILD);
 
+        if (bus->track_queue) {
+                *timeout_usec = 0;
+                return 1;
+        }
+
         if (bus->state == BUS_CLOSING) {
                 *timeout_usec = 0;
                 return 1;
@@ -2203,7 +2291,17 @@ finish:
         return r;
 }
 
-static int process_running(sd_bus *bus, sd_bus_message **ret) {
+static int dispatch_track(sd_bus *bus) {
+        assert(bus);
+
+        if (!bus->track_queue)
+                return 0;
+
+        bus_track_dispatch(bus->track_queue);
+        return 1;
+}
+
+static int process_running(sd_bus *bus, bool hint_priority, int64_t priority, sd_bus_message **ret) {
         _cleanup_bus_message_unref_ sd_bus_message *m = NULL;
         int r;
 
@@ -2218,7 +2316,11 @@ static int process_running(sd_bus *bus, sd_bus_message **ret) {
         if (r != 0)
                 goto null_message;
 
-        r = dispatch_rqueue(bus, &m);
+        r = dispatch_track(bus);
+        if (r != 0)
+                goto null_message;
+
+        r = dispatch_rqueue(bus, hint_priority, priority, &m);
         if (r < 0)
                 return r;
         if (!m)
@@ -2306,10 +2408,10 @@ static int process_closing(sd_bus *bus, sd_bus_message **ret) {
         /* Then, synthesize a Disconnected message */
         r = sd_bus_message_new_signal(
                         bus,
+                        &m,
                         "/org/freedesktop/DBus/Local",
                         "org.freedesktop.DBus.Local",
-                        "Disconnected",
-                        &m);
+                        "Disconnected");
         if (r < 0)
                 return r;
 
@@ -2344,7 +2446,7 @@ finish:
         return r;
 }
 
-_public_ int sd_bus_process(sd_bus *bus, sd_bus_message **ret) {
+static int bus_process_internal(sd_bus *bus, bool hint_priority, int64_t priority, sd_bus_message **ret) {
         BUS_DONT_DESTROY(bus);
         int r;
 
@@ -2393,7 +2495,7 @@ _public_ int sd_bus_process(sd_bus *bus, sd_bus_message **ret) {
 
         case BUS_RUNNING:
         case BUS_HELLO:
-                r = process_running(bus, ret);
+                r = process_running(bus, hint_priority, priority, ret);
                 if (r == -ENOTCONN || r == -ECONNRESET || r == -EPIPE || r == -ESHUTDOWN) {
                         bus_enter_closing(bus);
                         r = 1;
@@ -2411,6 +2513,14 @@ _public_ int sd_bus_process(sd_bus *bus, sd_bus_message **ret) {
         assert_not_reached("Unknown state");
 }
 
+_public_ int sd_bus_process(sd_bus *bus, sd_bus_message **ret) {
+        return bus_process_internal(bus, false, 0, ret);
+}
+
+_public_ int sd_bus_process_priority(sd_bus *bus, int64_t priority, sd_bus_message **ret) {
+        return bus_process_internal(bus, true, priority, ret);
+}
+
 static int bus_poll(sd_bus *bus, bool need_more, uint64_t timeout_usec) {
         struct pollfd p[2] = {};
         int r, e, n;
@@ -2735,7 +2845,7 @@ static int attach_io_events(sd_bus *bus) {
                 return 0;
 
         if (!bus->input_io_event_source) {
-                r = sd_event_add_io(bus->event, bus->input_fd, 0, io_callback, bus, &bus->input_io_event_source);
+                r = sd_event_add_io(bus->event, &bus->input_io_event_source, bus->input_fd, 0, io_callback, bus);
                 if (r < 0)
                         return r;
 
@@ -2754,7 +2864,7 @@ static int attach_io_events(sd_bus *bus) {
                 assert(bus->output_fd >= 0);
 
                 if (!bus->output_io_event_source) {
-                        r = sd_event_add_io(bus->event, bus->output_fd, 0, io_callback, bus, &bus->output_io_event_source);
+                        r = sd_event_add_io(bus->event, &bus->output_io_event_source, bus->output_fd, 0, io_callback, bus);
                         if (r < 0)
                                 return r;
 
@@ -2803,7 +2913,7 @@ _public_ int sd_bus_attach_event(sd_bus *bus, sd_event *event, int priority) {
 
         bus->event_priority = priority;
 
-        r = sd_event_add_monotonic(bus->event, 0, 0, time_callback, bus, &bus->time_event_source);
+        r = sd_event_add_monotonic(bus->event, &bus->time_event_source, 0, 0, time_callback, bus);
         if (r < 0)
                 goto fail;
 
@@ -2811,7 +2921,7 @@ _public_ int sd_bus_attach_event(sd_bus *bus, sd_event *event, int priority) {
         if (r < 0)
                 goto fail;
 
-        r = sd_event_add_exit(bus->event, quit_callback, bus, &bus->quit_event_source);
+        r = sd_event_add_exit(bus->event, &bus->quit_event_source, quit_callback, bus);
         if (r < 0)
                 goto fail;
 
@@ -2901,6 +3011,43 @@ _public_ int sd_bus_default_user(sd_bus **ret) {
         return bus_default(sd_bus_open_user, &default_user_bus, ret);
 }
 
+_public_ int sd_bus_default(sd_bus **ret) {
+
+        const char *e;
+
+        /* Let's try our best to reuse another cached connection. If
+         * the starter bus type is set, connect via our normal
+         * connection logic, ignoring $DBUS_STARTER_ADDRESS, so that
+         * we can share the connection with the user/system default
+         * bus. */
+
+        e = secure_getenv("DBUS_STARTER_BUS_TYPE");
+        if (e) {
+                if (streq(e, "system"))
+                        return sd_bus_default_system(ret);
+                else if (streq(e, "user") || streq(e, "session"))
+                        return sd_bus_default_user(ret);
+        }
+
+        /* No type is specified, so we have not other option than to
+         * use the starter address if it is set. */
+
+        e = secure_getenv("DBUS_STARTER_ADDRESS");
+        if (e) {
+                static thread_local sd_bus *default_starter_bus = NULL;
+
+                return bus_default(sd_bus_open, &default_starter_bus, ret);
+        }
+
+        /* Finally, if nothing is set use the cached connection for
+         * the right scope */
+
+        if (cg_pid_get_owner_uid(0, NULL) >= 0)
+                return sd_bus_default_user(ret);
+        else
+                return sd_bus_default_system(ret);
+}
+
 _public_ int sd_bus_get_tid(sd_bus *b, pid_t *tid) {
         assert_return(b, -EINVAL);
         assert_return(tid, -EINVAL);
@@ -2917,76 +3064,46 @@ _public_ int sd_bus_get_tid(sd_bus *b, pid_t *tid) {
         return -ENXIO;
 }
 
-_public_ char *sd_bus_label_escape(const char *s) {
-        char *r, *t;
-        const char *f;
-
-        assert_return(s, NULL);
-
-        /* Escapes all chars that D-Bus' object path cannot deal
-         * with. Can be reversed with bus_path_unescape(). We special
-         * case the empty string. */
-
-        if (*s == 0)
-                return strdup("_");
-
-        r = new(char, strlen(s)*3 + 1);
-        if (!r)
-                return NULL;
-
-        for (f = s, t = r; *f; f++) {
+_public_ int sd_bus_path_encode(const char *prefix, const char *external_id, char **ret_path) {
+        _cleanup_free_ char *e = NULL;
+        char *ret;
 
-                /* Escape everything that is not a-zA-Z0-9. We also
-                 * escape 0-9 if it's the first character */
+        assert_return(object_path_is_valid(prefix), -EINVAL);
+        assert_return(external_id, -EINVAL);
+        assert_return(ret_path, -EINVAL);
 
-                if (!(*f >= 'A' && *f <= 'Z') &&
-                    !(*f >= 'a' && *f <= 'z') &&
-                    !(f > s && *f >= '0' && *f <= '9')) {
-                        *(t++) = '_';
-                        *(t++) = hexchar(*f >> 4);
-                        *(t++) = hexchar(*f);
-                } else
-                        *(t++) = *f;
-        }
+        e = bus_label_escape(external_id);
+        if (!e)
+                return -ENOMEM;
 
-        *t = 0;
+        ret = strjoin(prefix, "/", e, NULL);
+        if (!ret)
+                return -ENOMEM;
 
-        return r;
+        *ret_path = ret;
+        return 0;
 }
 
-_public_ char *sd_bus_label_unescape(const char *f) {
-        char *r, *t;
-
-        assert_return(f, NULL);
-
-        /* Special case for the empty string */
-        if (streq(f, "_"))
-                return strdup("");
-
-        r = new(char, strlen(f) + 1);
-        if (!r)
-                return NULL;
-
-        for (t = r; *f; f++) {
+_public_ int sd_bus_path_decode(const char *path, const char *prefix, char **external_id) {
+        const char *e;
+        char *ret;
 
-                if (*f == '_') {
-                        int a, b;
+        assert_return(object_path_is_valid(path), -EINVAL);
+        assert_return(object_path_is_valid(prefix), -EINVAL);
+        assert_return(external_id, -EINVAL);
 
-                        if ((a = unhexchar(f[1])) < 0 ||
-                            (b = unhexchar(f[2])) < 0) {
-                                /* Invalid escape code, let's take it literal then */
-                                *(t++) = '_';
-                        } else {
-                                *(t++) = (char) ((a << 4) | b);
-                                f += 2;
-                        }
-                } else
-                        *(t++) = *f;
+        e = object_path_startswith(path, prefix);
+        if (!e) {
+                *external_id = NULL;
+                return 0;
         }
 
-        *t = 0;
+        ret = bus_label_unescape(e);
+        if (!ret)
+                return -ENOMEM;
 
-        return r;
+        *external_id = ret;
+        return 1;
 }
 
 _public_ int sd_bus_get_peer_creds(sd_bus *bus, uint64_t mask, sd_bus_creds **ret) {