chiark / gitweb /
bus: connect directly via kdbus in sd_bus_open_system_container()
[elogind.git] / src / libsystemd-bus / sd-bus.c
index 05c5d8d1bc666274984582c0d7a2213dc7d82f99..edd917e30375786811727fd44590625e99ce3df1 100644 (file)
@@ -47,6 +47,7 @@
 #include "bus-objects.h"
 #include "bus-util.h"
 #include "bus-container.h"
+#include "bus-protocol.h"
 
 static int bus_poll(sd_bus *bus, bool need_more, uint64_t timeout_usec);
 
@@ -181,6 +182,7 @@ _public_ int sd_bus_new(sd_bus **ret) {
         r->n_ref = REFCNT_INIT;
         r->input_fd = r->output_fd = -1;
         r->message_version = 1;
+        r->creds_mask |= SD_BUS_CREDS_WELL_KNOWN_NAMES|SD_BUS_CREDS_UNIQUE_NAME;
         r->hello_flags |= KDBUS_HELLO_ACCEPT_FD;
         r->attach_flags |= KDBUS_ATTACH_NAMES;
         r->original_pid = getpid();
@@ -286,11 +288,14 @@ _public_ int sd_bus_negotiate_attach_timestamp(sd_bus *bus, int b) {
 
 _public_ int sd_bus_negotiate_attach_creds(sd_bus *bus, uint64_t mask) {
         assert_return(bus, -EINVAL);
-        assert_return(mask <= _SD_BUS_CREDS_MAX, -EINVAL);
+        assert_return(mask <= _SD_BUS_CREDS_ALL, -EINVAL);
         assert_return(bus->state == BUS_UNSET, -EPERM);
         assert_return(!bus_pid_changed(bus), -ECHILD);
 
-        return kdbus_translate_attach_flags(mask, &bus->creds_mask);
+        /* The well knowns we need unconditionally, so that matches can work */
+        bus->creds_mask = mask | SD_BUS_CREDS_WELL_KNOWN_NAMES|SD_BUS_CREDS_UNIQUE_NAME;
+
+        return kdbus_translate_attach_flags(bus->creds_mask, &bus->creds_mask);
 }
 
 _public_ int sd_bus_set_server(sd_bus *bus, int b, sd_id128_t server_id) {
@@ -313,6 +318,15 @@ _public_ int sd_bus_set_anonymous(sd_bus *bus, int b) {
         return 0;
 }
 
+_public_ int sd_bus_set_trusted(sd_bus *bus, int b) {
+        assert_return(bus, -EINVAL);
+        assert_return(bus->state == BUS_UNSET, -EPERM);
+        assert_return(!bus_pid_changed(bus), -ECHILD);
+
+        bus->trusted = !!b;
+        return 0;
+}
+
 static int hello_callback(sd_bus *bus, sd_bus_message *reply, void *userdata, sd_bus_error *error) {
         const char *s;
         int r;
@@ -750,6 +764,9 @@ static int parse_container_address(sd_bus *b, const char **p, char **guid) {
         if (!machine)
                 return -EINVAL;
 
+        if (!filename_is_safe(machine))
+                return -EINVAL;
+
         free(b->machine);
         b->machine = machine;
         machine = NULL;
@@ -986,18 +1003,25 @@ _public_ int sd_bus_open_system(sd_bus **ret) {
                 return r;
 
         e = secure_getenv("DBUS_SYSTEM_BUS_ADDRESS");
-        if (e) {
+        if (e)
                 r = sd_bus_set_address(b, e);
-                if (r < 0)
-                        goto fail;
-        } else {
-                b->sockaddr.un.sun_family = AF_UNIX;
-                strncpy(b->sockaddr.un.sun_path, "/run/dbus/system_bus_socket", sizeof(b->sockaddr.un.sun_path));
-                b->sockaddr_size = offsetof(struct sockaddr_un, sun_path) + sizeof("/run/dbus/system_bus_socket") - 1;
-        }
+        else
+#ifdef ENABLE_KDBUS
+                r = sd_bus_set_address(b, "kernel:path=/dev/kdbus/0-system/bus;unix:path=/run/dbus/system_bus_socket");
+#else
+                r = sd_bus_set_address(b, "unix:path=/run/dbus/system_bus_socket");
+#endif
+
+        if (r < 0)
+                goto fail;
 
         b->bus_client = true;
 
+        /* Let's do per-method access control on the system bus. We
+         * need the caller's UID and capability set for that. */
+        b->trusted = false;
+        b->attach_flags |= KDBUS_ATTACH_CAPS | KDBUS_ATTACH_CREDS;
+
         r = sd_bus_start(b);
         if (r < 0)
                 goto fail;
@@ -1013,7 +1037,6 @@ fail:
 _public_ int sd_bus_open_user(sd_bus **ret) {
         const char *e;
         sd_bus *b;
-        size_t l;
         int r;
 
         assert_return(ret, -EINVAL);
@@ -1029,24 +1052,40 @@ _public_ int sd_bus_open_user(sd_bus **ret) {
                         goto fail;
         } else {
                 e = secure_getenv("XDG_RUNTIME_DIR");
-                if (!e) {
-                        r = -ENOENT;
-                        goto fail;
+                if (e) {
+                        _cleanup_free_ char *ee = NULL;
+
+                        ee = bus_address_escape(e);
+                        if (!ee) {
+                                r = -ENOMEM;
+                                goto fail;
+                        }
+
+#ifdef ENABLE_KDBUS
+                        asprintf(&b->address, "kernel:path=/dev/kdbus/%lu-user/bus;unix:path=%s/bus", (unsigned long) getuid(), ee);
+#else
+                        b->address = strjoin("unix:path=", ee, "/bus", NULL);
+#endif
+                } else {
+#ifdef ENABLE_KDBUS
+                        asprintf(&b->address, "kernel:path=/dev/kdbus/%lu-user/bus", (unsigned long) getuid());
+#else
+                        return -ECONNREFUSED;
+#endif
                 }
 
-                l = strlen(e);
-                if (l + 4 > sizeof(b->sockaddr.un.sun_path)) {
-                        r = -E2BIG;
+                if (!b->address) {
+                        r = -ENOMEM;
                         goto fail;
                 }
-
-                b->sockaddr.un.sun_family = AF_UNIX;
-                memcpy(mempcpy(b->sockaddr.un.sun_path, e, l), "/bus", 4);
-                b->sockaddr_size = offsetof(struct sockaddr_un, sun_path) + l + 4;
         }
 
         b->bus_client = true;
 
+        /* We don't do any per-method access control on the user
+         * bus. */
+        b->trusted = true;
+
         r = sd_bus_start(b);
         if (r < 0)
                 goto fail;
@@ -1103,12 +1142,17 @@ _public_ int sd_bus_open_system_container(const char *machine, sd_bus **ret) {
 
         assert_return(machine, -EINVAL);
         assert_return(ret, -EINVAL);
+        assert_return(filename_is_safe(machine), -EINVAL);
 
         e = bus_address_escape(machine);
         if (!e)
                 return -ENOMEM;
 
+#ifdef ENABLE_KDBUS
+        p = strjoin("kernel:path=/dev/kdbus/ns/machine-", e, "/0-system/bus;x-container:machine=", e, NULL);
+#else
         p = strjoin("x-container:machine=", e, NULL);
+#endif
         if (!p)
                 return -ENOMEM;
 
@@ -1153,9 +1197,8 @@ _public_ void sd_bus_close(sd_bus *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. */
+         * bus, and they might need to invoke the * KDBUS_CMD_FREE
+         * ioctl on the fd when they are freed. */
 }
 
 static void bus_enter_closing(sd_bus *bus) {
@@ -1179,7 +1222,9 @@ _public_ sd_bus *sd_bus_ref(sd_bus *bus) {
 }
 
 _public_ sd_bus *sd_bus_unref(sd_bus *bus) {
-        assert_return(bus, NULL);
+
+        if (!bus)
+                return NULL;
 
         if (REFCNT_DEC(bus->n_ref) <= 0)
                 bus_free(bus);
@@ -1268,8 +1313,6 @@ int bus_seal_synthetic_message(sd_bus *b, sd_bus_message *m) {
 }
 
 static int bus_write_message(sd_bus *bus, sd_bus_message *message, size_t *idx) {
-        int r;
-
         assert(bus);
         assert(message);
 
@@ -1277,8 +1320,6 @@ static int bus_write_message(sd_bus *bus, sd_bus_message *message, size_t *idx)
                 return bus_kernel_write_message(bus, message);
         else
                 return bus_socket_write_message(bus, message, idx);
-
-        return r;
 }
 
 static int dispatch_wqueue(sd_bus *bus) {
@@ -1396,7 +1437,7 @@ _public_ int sd_bus_send(sd_bus *bus, sd_bus_message *m, uint64_t *serial) {
         /* If the serial number isn't kept, then we know that no reply
          * is expected */
         if (!serial && !m->sealed)
-                m->header->flags |= SD_BUS_MESSAGE_NO_REPLY_EXPECTED;
+                m->header->flags |= BUS_MESSAGE_NO_REPLY_EXPECTED;
 
         r = bus_seal_message(bus, m);
         if (r < 0)
@@ -1411,9 +1452,12 @@ _public_ int sd_bus_send(sd_bus *bus, sd_bus_message *m, uint64_t *serial) {
                 size_t idx = 0;
 
                 r = bus_write_message(bus, m, &idx);
-                if (r < 0)
+                if (r < 0) {
+                        if (r == -EPIPE || r == -ENOTCONN || r == -ESHUTDOWN)
+                                bus_enter_closing(bus);
+
                         return r;
-                else if (!bus->is_kernel && idx < BUS_MESSAGE_SIZE(m))  {
+                else if (!bus->is_kernel && idx < BUS_MESSAGE_SIZE(m))  {
                         /* Wasn't fully written. So let's remember how
                          * much was written. Note that the first entry
                          * of the wqueue array is always allocated so
@@ -1509,7 +1553,7 @@ _public_ int sd_bus_call_async(
         assert_return(BUS_IS_OPEN(bus->state), -ENOTCONN);
         assert_return(m, -EINVAL);
         assert_return(m->header->type == SD_BUS_MESSAGE_METHOD_CALL, -EINVAL);
-        assert_return(!(m->header->flags & SD_BUS_MESSAGE_NO_REPLY_EXPECTED), -EINVAL);
+        assert_return(!(m->header->flags & BUS_MESSAGE_NO_REPLY_EXPECTED), -EINVAL);
         assert_return(callback, -EINVAL);
         assert_return(!bus_pid_changed(bus), -ECHILD);
 
@@ -1619,7 +1663,7 @@ _public_ int sd_bus_call(
         assert_return(BUS_IS_OPEN(bus->state), -ENOTCONN);
         assert_return(m, -EINVAL);
         assert_return(m->header->type == SD_BUS_MESSAGE_METHOD_CALL, -EINVAL);
-        assert_return(!(m->header->flags & SD_BUS_MESSAGE_NO_REPLY_EXPECTED), -EINVAL);
+        assert_return(!(m->header->flags & BUS_MESSAGE_NO_REPLY_EXPECTED), -EINVAL);
         assert_return(!bus_error_is_dirty(error), -EINVAL);
         assert_return(!bus_pid_changed(bus), -ECHILD);
 
@@ -1687,8 +1731,12 @@ _public_ int sd_bus_call(
                 }
 
                 r = bus_read_message(bus);
-                if (r < 0)
+                if (r < 0) {
+                        if (r == -EPIPE || r == -ENOTCONN || r == -ESHUTDOWN)
+                                bus_enter_closing(bus);
+
                         return r;
+                }
                 if (r > 0)
                         continue;
 
@@ -1708,8 +1756,12 @@ _public_ int sd_bus_call(
                         return r;
 
                 r = dispatch_wqueue(bus);
-                if (r < 0)
+                if (r < 0) {
+                        if (r == -EPIPE || r == -ENOTCONN || r == -ESHUTDOWN)
+                                bus_enter_closing(bus);
+
                         return r;
+                }
         }
 }
 
@@ -1953,7 +2005,7 @@ static int process_builtin(sd_bus *bus, sd_bus_message *m) {
         if (!streq_ptr(m->interface, "org.freedesktop.DBus.Peer"))
                 return 0;
 
-        if (m->header->flags & SD_BUS_MESSAGE_NO_REPLY_EXPECTED)
+        if (m->header->flags & BUS_MESSAGE_NO_REPLY_EXPECTED)
                 return 1;
 
         if (streq_ptr(m->member, "Ping"))
@@ -2188,7 +2240,7 @@ _public_ int sd_bus_process(sd_bus *bus, sd_bus_message **ret) {
 
         case BUS_OPENING:
                 r = bus_socket_process_opening(bus);
-                if (r == -ECONNRESET || r == -EPIPE) {
+                if (r == -ECONNRESET || r == -EPIPE || r == -ESHUTDOWN) {
                         bus_enter_closing(bus);
                         r = 1;
                 } else if (r < 0)
@@ -2199,7 +2251,7 @@ _public_ int sd_bus_process(sd_bus *bus, sd_bus_message **ret) {
 
         case BUS_AUTHENTICATING:
                 r = bus_socket_process_authenticating(bus);
-                if (r == -ECONNRESET || r == -EPIPE) {
+                if (r == -ECONNRESET || r == -EPIPE || r == -ESHUTDOWN) {
                         bus_enter_closing(bus);
                         r = 1;
                 } else if (r < 0)
@@ -2213,7 +2265,7 @@ _public_ int sd_bus_process(sd_bus *bus, sd_bus_message **ret) {
         case BUS_RUNNING:
         case BUS_HELLO:
                 r = process_running(bus, ret);
-                if (r == -ECONNRESET || r == -EPIPE) {
+                if (r == -ECONNRESET || r == -EPIPE || r == -ESHUTDOWN) {
                         bus_enter_closing(bus);
                         r = 1;
 
@@ -2324,8 +2376,12 @@ _public_ int sd_bus_flush(sd_bus *bus) {
 
         for (;;) {
                 r = dispatch_wqueue(bus);
-                if (r < 0)
+                if (r < 0) {
+                        if (r == -EPIPE || r == -ENOTCONN || r == -ESHUTDOWN)
+                                bus_enter_closing(bus);
+
                         return r;
+                }
 
                 if (bus->wqueue_size <= 0)
                         return 0;
@@ -2597,7 +2653,9 @@ fail:
 
 _public_ int sd_bus_detach_event(sd_bus *bus) {
         assert_return(bus, -EINVAL);
-        assert_return(bus->event, -ENXIO);
+
+        if (!bus->event)
+                return 0;
 
         if (bus->input_io_event_source) {
                 sd_event_source_set_enabled(bus->input_io_event_source, SD_EVENT_OFF);
@@ -2622,7 +2680,7 @@ _public_ int sd_bus_detach_event(sd_bus *bus) {
         if (bus->event)
                 bus->event = sd_event_unref(bus->event);
 
-        return 0;
+        return 1;
 }
 
 _public_ sd_event* sd_bus_get_event(sd_bus *bus) {
@@ -2770,7 +2828,7 @@ _public_ int sd_bus_get_peer_creds(sd_bus *bus, uint64_t mask, sd_bus_creds **re
         int r;
 
         assert_return(bus, -EINVAL);
-        assert_return(mask <= _SD_BUS_CREDS_MAX, -ENOTSUP);
+        assert_return(mask <= _SD_BUS_CREDS_ALL, -ENOTSUP);
         assert_return(ret, -EINVAL);
         assert_return(BUS_IS_OPEN(bus->state), -ENOTCONN);
         assert_return(!bus_pid_changed(bus), -ECHILD);
@@ -2788,7 +2846,7 @@ _public_ int sd_bus_get_peer_creds(sd_bus *bus, uint64_t mask, sd_bus_creds **re
                 c->uid = bus->ucred.uid;
                 c->gid = bus->ucred.gid;
 
-                c->mask |= ((SD_BUS_CREDS_UID | SD_BUS_CREDS_PID | SD_BUS_CREDS_GID) & mask) & bus->creds_mask;
+                c->mask |= (SD_BUS_CREDS_UID | SD_BUS_CREDS_PID | SD_BUS_CREDS_GID) & mask;
         }
 
         if (!isempty(bus->label) && (mask & SD_BUS_CREDS_SELINUX_CONTEXT)) {
@@ -2798,7 +2856,7 @@ _public_ int sd_bus_get_peer_creds(sd_bus *bus, uint64_t mask, sd_bus_creds **re
                         return -ENOMEM;
                 }
 
-                c->mask |= SD_BUS_CREDS_SELINUX_CONTEXT | bus->creds_mask;
+                c->mask |= SD_BUS_CREDS_SELINUX_CONTEXT;
         }
 
         r = bus_creds_add_more(c, mask, pid, 0);