chiark / gitweb /
bus: synthesize local error reply when we cannot deliver a message to kdbus because...
[elogind.git] / src / libsystemd-bus / sd-bus.c
index bfa6ba4dd670bfd4fc2279713387c16514633ec5..05c5d8d1bc666274984582c0d7a2213dc7d82f99 100644 (file)
@@ -290,33 +290,7 @@ _public_ int sd_bus_negotiate_attach_creds(sd_bus *bus, uint64_t mask) {
         assert_return(bus->state == BUS_UNSET, -EPERM);
         assert_return(!bus_pid_changed(bus), -ECHILD);
 
-        SET_FLAG(bus->attach_flags, KDBUS_ATTACH_CREDS,
-                 !!(mask & (SD_BUS_CREDS_UID|SD_BUS_CREDS_GID|SD_BUS_CREDS_PID|SD_BUS_CREDS_PID_STARTTIME|SD_BUS_CREDS_TID)));
-
-        SET_FLAG(bus->attach_flags, KDBUS_ATTACH_COMM,
-                 !!(mask & (SD_BUS_CREDS_COMM|SD_BUS_CREDS_TID_COMM)));
-
-        SET_FLAG(bus->attach_flags, KDBUS_ATTACH_EXE,
-                 !!(mask & SD_BUS_CREDS_EXE));
-
-        SET_FLAG(bus->attach_flags, KDBUS_ATTACH_CMDLINE,
-                 !!(mask & SD_BUS_CREDS_CMDLINE));
-
-        SET_FLAG(bus->attach_flags, KDBUS_ATTACH_CGROUP,
-                 !!(mask & (SD_BUS_CREDS_CGROUP|SD_BUS_CREDS_UNIT|SD_BUS_CREDS_USER_UNIT|SD_BUS_CREDS_SLICE|SD_BUS_CREDS_SESSION|SD_BUS_CREDS_OWNER_UID)));
-
-        SET_FLAG(bus->attach_flags, KDBUS_ATTACH_CAPS,
-                 !!(mask & (SD_BUS_CREDS_EFFECTIVE_CAPS|SD_BUS_CREDS_PERMITTED_CAPS|SD_BUS_CREDS_INHERITABLE_CAPS|SD_BUS_CREDS_BOUNDING_CAPS)));
-
-        SET_FLAG(bus->attach_flags, KDBUS_ATTACH_SECLABEL,
-                 !!(mask & SD_BUS_CREDS_SELINUX_CONTEXT));
-
-        SET_FLAG(bus->attach_flags, KDBUS_ATTACH_AUDIT,
-                 !!(mask & (SD_BUS_CREDS_AUDIT_SESSION_ID|SD_BUS_CREDS_AUDIT_LOGIN_UID)));
-
-        bus->creds_mask = mask;
-
-        return 0;
+        return kdbus_translate_attach_flags(mask, &bus->creds_mask);
 }
 
 _public_ int sd_bus_set_server(sd_bus *bus, int b, sd_id128_t server_id) {
@@ -1257,7 +1231,8 @@ _public_ int sd_bus_get_server_id(sd_bus *bus, sd_id128_t *server_id) {
         return 0;
 }
 
-int bus_seal_message(sd_bus *b, sd_bus_message *m) {
+static int bus_seal_message(sd_bus *b, sd_bus_message *m) {
+        assert(b);
         assert(m);
 
         if (m->header->version > b->message_version)
@@ -1274,6 +1249,24 @@ int bus_seal_message(sd_bus *b, sd_bus_message *m) {
         return bus_message_seal(m, ++b->serial);
 }
 
+int bus_seal_synthetic_message(sd_bus *b, sd_bus_message *m) {
+        assert(b);
+        assert(m);
+
+        if (m->header->version > b->message_version)
+                return -EPERM;
+
+        /* The bus specification says the serial number cannot be 0,
+         * hence let's fill something in for synthetic messages. Since
+         * synthetic messages might have a fake sender and we don't
+         * want to interfere with the real sender's serial numbers we
+         * pick a fixed, artifical one. We use (uint32_t) -1 rather
+         * than (uint64_t) -1 since dbus1 only had 32bit identifiers,
+         * even though kdbus can do 64bit. */
+
+        return bus_message_seal(m, 0xFFFFFFFFULL);
+}
+
 static int bus_write_message(sd_bus *bus, sd_bus_message *message, size_t *idx) {
         int r;
 
@@ -1281,9 +1274,9 @@ static int bus_write_message(sd_bus *bus, sd_bus_message *message, size_t *idx)
         assert(message);
 
         if (bus->is_kernel)
-                r = bus_kernel_write_message(bus, message);
+                return bus_kernel_write_message(bus, message);
         else
-                r = bus_socket_write_message(bus, message, idx);
+                return bus_socket_write_message(bus, message, idx);
 
         return r;
 }
@@ -1325,50 +1318,63 @@ static int dispatch_wqueue(sd_bus *bus) {
         return ret;
 }
 
-static int bus_read_message(sd_bus *bus, sd_bus_message **m) {
-        int r;
-
+static int bus_read_message(sd_bus *bus) {
         assert(bus);
-        assert(m);
 
         if (bus->is_kernel)
-                r = bus_kernel_read_message(bus, m);
+                return bus_kernel_read_message(bus);
         else
-                r = bus_socket_read_message(bus, m);
+                return bus_socket_read_message(bus);
+}
 
-        return r;
+int bus_rqueue_make_room(sd_bus *bus) {
+        sd_bus_message **q;
+        unsigned x;
+
+        x = bus->rqueue_size + 1;
+
+        if (bus->rqueue_allocated >= x)
+                return 0;
+
+        if (x > BUS_RQUEUE_MAX)
+                return -ENOBUFS;
+
+        q = realloc(bus->rqueue, x * sizeof(sd_bus_message*));
+        if (!q)
+                return -ENOMEM;
+
+        bus->rqueue = q;
+        bus->rqueue_allocated = x;
+
+        return 0;
 }
 
 static int dispatch_rqueue(sd_bus *bus, sd_bus_message **m) {
-        sd_bus_message *z = NULL;
         int r, ret = 0;
 
         assert(bus);
         assert(m);
         assert(bus->state == BUS_RUNNING || bus->state == BUS_HELLO);
 
-        if (bus->rqueue_size > 0) {
-                /* Dispatch a queued message */
+        for (;;) {
+                if (bus->rqueue_size > 0) {
+                        /* Dispatch a queued message */
 
-                *m = bus->rqueue[0];
-                bus->rqueue_size --;
-                memmove(bus->rqueue, bus->rqueue + 1, sizeof(sd_bus_message*) * bus->rqueue_size);
-                return 1;
-        }
+                        *m = bus->rqueue[0];
+                        bus->rqueue_size --;
+                        memmove(bus->rqueue, bus->rqueue + 1, sizeof(sd_bus_message*) * bus->rqueue_size);
+                        return 1;
+                }
 
-        /* Try to read a new message */
-        do {
-                r = bus_read_message(bus, &z);
+                /* Try to read a new message */
+                r = bus_read_message(bus);
                 if (r < 0)
                         return r;
                 if (r == 0)
                         return ret;
 
                 ret = 1;
-        } while (!z);
-
-        *m = z;
-        return ret;
+        }
 }
 
 _public_ int sd_bus_send(sd_bus *bus, sd_bus_message *m, uint64_t *serial) {
@@ -1604,10 +1610,10 @@ _public_ int sd_bus_call(
                 sd_bus_error *error,
                 sd_bus_message **reply) {
 
-        int r;
         usec_t timeout;
         uint64_t serial;
-        bool room = false;
+        unsigned i;
+        int r;
 
         assert_return(bus, -EINVAL);
         assert_return(BUS_IS_OPEN(bus->state), -ENOTCONN);
@@ -1621,6 +1627,8 @@ _public_ int sd_bus_call(
         if (r < 0)
                 return r;
 
+        i = bus->rqueue_size;
+
         r = sd_bus_send(bus, m, &serial);
         if (r < 0)
                 return r;
@@ -1629,34 +1637,18 @@ _public_ int sd_bus_call(
 
         for (;;) {
                 usec_t left;
-                sd_bus_message *incoming = NULL;
-
-                if (!room) {
-                        sd_bus_message **q;
-
-                        if (bus->rqueue_size >= BUS_RQUEUE_MAX)
-                                return -ENOBUFS;
-
-                        /* Make sure there's room for queuing this
-                         * locally, before we read the message */
-
-                        q = realloc(bus->rqueue, (bus->rqueue_size + 1) * sizeof(sd_bus_message*));
-                        if (!q)
-                                return -ENOMEM;
 
-                        bus->rqueue = q;
-                        room = true;
-                }
-
-                r = bus_read_message(bus, &incoming);
-                if (r < 0)
-                        return r;
+                while (i < bus->rqueue_size) {
+                        sd_bus_message *incoming = NULL;
 
-                if (incoming) {
+                        incoming = bus->rqueue[i];
 
                         if (incoming->reply_serial == serial) {
                                 /* Found a match! */
 
+                                memmove(bus->rqueue + i, bus->rqueue + i + 1, sizeof(sd_bus_message*) * (bus->rqueue_size - i - 1));
+                                bus->rqueue_size--;
+
                                 if (incoming->header->type == SD_BUS_MESSAGE_METHOD_RETURN) {
 
                                         if (reply)
@@ -1665,30 +1657,22 @@ _public_ int sd_bus_call(
                                                 sd_bus_message_unref(incoming);
 
                                         return 1;
-                                }
-
-                                if (incoming->header->type == SD_BUS_MESSAGE_METHOD_ERROR) {
-                                        int k;
-
+                                } else if (incoming->header->type == SD_BUS_MESSAGE_METHOD_ERROR)
                                         r = sd_bus_error_copy(error, &incoming->error);
-                                        if (r < 0) {
-                                                sd_bus_message_unref(incoming);
-                                                return r;
-                                        }
-
-                                        k = sd_bus_error_get_errno(&incoming->error);
-                                        sd_bus_message_unref(incoming);
-                                        return -k;
-                                }
+                                else
+                                        r = -EIO;
 
                                 sd_bus_message_unref(incoming);
-                                return -EIO;
+                                return r;
 
                         } else if (incoming->header->serial == serial &&
                                    bus->unique_name &&
                                    incoming->sender &&
                                    streq(bus->unique_name, incoming->sender)) {
 
+                                memmove(bus->rqueue + i, bus->rqueue + i + 1, sizeof(sd_bus_message*) * (bus->rqueue_size - i - 1));
+                                bus->rqueue_size--;
+
                                 /* Our own message? Somebody is trying
                                  * to send its own client a message,
                                  * let's not dead-lock, let's fail
@@ -1698,15 +1682,14 @@ _public_ int sd_bus_call(
                                 return -ELOOP;
                         }
 
-                        /* There's already guaranteed to be room for
-                         * this, so need to resize things here */
-                        bus->rqueue[bus->rqueue_size ++] = incoming;
-                        room = false;
-
                         /* Try to read more, right-away */
-                        continue;
+                        i++;
                 }
-                if (r != 0)
+
+                r = bus_read_message(bus);
+                if (r < 0)
+                        return r;
+                if (r > 0)
                         continue;
 
                 if (timeout > 0) {
@@ -1830,7 +1813,7 @@ static int process_timeout(sd_bus *bus) {
 
         m->sender = "org.freedesktop.DBus";
 
-        r = bus_seal_message(bus, m);
+        r = bus_seal_synthetic_message(bus, m);
         if (r < 0)
                 return r;
 
@@ -2122,7 +2105,7 @@ static int process_closing(sd_bus *bus, sd_bus_message **ret) {
                 if (r < 0)
                         return r;
 
-                r = bus_seal_message(bus, m);
+                r = bus_seal_synthetic_message(bus, m);
                 if (r < 0)
                         return r;
 
@@ -2153,7 +2136,7 @@ static int process_closing(sd_bus *bus, sd_bus_message **ret) {
 
         m->sender = "org.freedesktop.DBus.Local";
 
-        r = bus_seal_message(bus, m);
+        r = bus_seal_synthetic_message(bus, m);
         if (r < 0)
                 return r;