chiark / gitweb /
bus-proxyd: enforce policy for method calls
[elogind.git] / src / bus-proxyd / bus-proxyd.c
index ca2a2ab44de16cfc93885ad477a11891fbb783c0..1106986e996cfb303c84b0218da195a59eeb689f 100644 (file)
@@ -4,6 +4,8 @@
   This file is part of systemd.
 
   Copyright 2010 Lennart Poettering
+  Copyright 2013 Daniel Mack
+  Copyright 2014 Kay Sievers
 
   systemd is free software; you can redistribute it and/or modify it
   under the terms of the GNU Lesser General Public License as published by
 #include "build.h"
 #include "strv.h"
 #include "def.h"
+#include "capability.h"
+#include "bus-policy.h"
 
-static const char *arg_address = DEFAULT_SYSTEM_BUS_PATH;
+static char *arg_address = NULL;
 static char *arg_command_line_buffer = NULL;
+static bool arg_drop_privileges = false;
+static char **arg_configuration = NULL;
+
+static Hashmap *names_hash = NULL;
 
 static int help(void) {
 
         printf("%s [OPTIONS...]\n\n"
                "Connect STDIO or a socket to a given bus address.\n\n"
-               "  -h --help              Show this help\n"
-               "     --version           Show package version\n"
-               "     --address=ADDRESS   Connect to the bus specified by ADDRESS\n"
-               "                         (default: " DEFAULT_SYSTEM_BUS_PATH ")\n",
+               "  -h --help               Show this help\n"
+               "     --version            Show package version\n"
+               "     --drop-privileges    Drop privileges\n"
+               "     --configuration=PATH Configuration file or directory\n"
+               "     --machine=MACHINE    Connect to specified machine\n"
+               "     --address=ADDRESS    Connect to the bus specified by ADDRESS\n"
+               "                          (default: " DEFAULT_SYSTEM_BUS_PATH ")\n",
                program_invocation_short_name);
 
         return 0;
@@ -63,21 +74,27 @@ static int parse_argv(int argc, char *argv[]) {
         enum {
                 ARG_VERSION = 0x100,
                 ARG_ADDRESS,
+                ARG_DROP_PRIVILEGES,
+                ARG_CONFIGURATION,
+                ARG_MACHINE,
         };
 
         static const struct option options[] = {
-                { "help",       no_argument,       NULL, 'h'            },
-                { "version",    no_argument,       NULL, ARG_VERSION    },
-                { "address",    required_argument, NULL, ARG_ADDRESS    },
-                { NULL,         0,                 NULL, 0              }
+                { "help",            no_argument,       NULL, 'h'                 },
+                { "version",         no_argument,       NULL, ARG_VERSION         },
+                { "address",         required_argument, NULL, ARG_ADDRESS         },
+                { "drop-privileges", no_argument,       NULL, ARG_DROP_PRIVILEGES },
+                { "configuration",   required_argument, NULL, ARG_CONFIGURATION   },
+                { "machine",         required_argument, NULL, ARG_MACHINE         },
+                {},
         };
 
-        int c;
+        int c, r;
 
         assert(argc >= 0);
         assert(argv);
 
-        while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0) {
+        while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0)
 
                 switch (c) {
 
@@ -90,9 +107,49 @@ static int parse_argv(int argc, char *argv[]) {
                         puts(SYSTEMD_FEATURES);
                         return 0;
 
-                case ARG_ADDRESS:
-                        arg_address = optarg;
+                case ARG_ADDRESS: {
+                        char *a;
+
+                        a = strdup(optarg);
+                        if (!a)
+                                return log_oom();
+
+                        free(arg_address);
+                        arg_address = a;
                         break;
+                }
+
+                case ARG_DROP_PRIVILEGES:
+                        arg_drop_privileges = true;
+                        break;
+
+                case ARG_CONFIGURATION:
+                        r = strv_extend(&arg_configuration, optarg);
+                        if (r < 0)
+                                return log_oom();
+                        break;
+
+                case ARG_MACHINE: {
+                        _cleanup_free_ char *e = NULL;
+                        char *a;
+
+                        e = bus_address_escape(optarg);
+                        if (!e)
+                                return log_oom();
+
+#ifdef ENABLE_KDBUS
+                        a = strjoin("x-container-kernel:machine=", e, ";x-container-unix:machine=", e, NULL);
+#else
+                        a = strjoin("x-container-unix:machine=", e, NULL);
+#endif
+                        if (!a)
+                                return log_oom();
+
+                        free(arg_address);
+                        arg_address = a;
+
+                        break;
+                }
 
                 case '?':
                         return -EINVAL;
@@ -100,18 +157,22 @@ static int parse_argv(int argc, char *argv[]) {
                 default:
                         assert_not_reached("Unhandled option");
                 }
-        }
 
         /* If the first command line argument is only "x" characters
          * we'll write who we are talking to into it, so that "ps" is
          * explanatory */
         arg_command_line_buffer = argv[optind];
-        if (argc > optind + 1 ||
-            (arg_command_line_buffer && arg_command_line_buffer[strspn(arg_command_line_buffer, "x")] != 0)) {
+        if (argc > optind + 1 || (arg_command_line_buffer && !in_charset(arg_command_line_buffer, "x"))) {
                 log_error("Too many arguments");
                 return -EINVAL;
         }
 
+        if (!arg_address) {
+                arg_address = strdup(DEFAULT_SYSTEM_BUS_PATH);
+                if (!arg_address)
+                        return log_oom();
+        }
+
         return 1;
 }
 
@@ -127,7 +188,7 @@ static int rename_service(sd_bus *a, sd_bus *b) {
         assert(a);
         assert(b);
 
-        r = sd_bus_get_peer_creds(b, SD_BUS_CREDS_UID|SD_BUS_CREDS_PID|SD_BUS_CREDS_CMDLINE|SD_BUS_CREDS_COMM, &creds);
+        r = sd_bus_get_owner_creds(b, SD_BUS_CREDS_UID|SD_BUS_CREDS_PID|SD_BUS_CREDS_CMDLINE|SD_BUS_CREDS_COMM, &creds);
         if (r < 0)
                 return r;
 
@@ -172,14 +233,14 @@ static int rename_service(sd_bus *a, sd_bus *b) {
                              uid, name);
 
                 if (m > w)
-                        memset(arg_command_line_buffer + w, 0, m - w);
+                        memzero(arg_command_line_buffer + w, m - w);
         }
 
         log_debug("Running on behalf of PID "PID_FMT" (%s), UID "UID_FMT" (%s), %s",
                   pid, p,
                   uid, name,
                   a->unique_name);
-                ;
+
         return 0;
 }
 
@@ -216,19 +277,19 @@ static int synthesize_name_acquired(sd_bus *a, sd_bus *b, sd_bus_message *m) {
 
                 r = sd_bus_message_new_signal(
                                 b,
+                                &n,
                                 "/org/freedesktop/DBus",
                                 "org.freedesktop.DBus",
-                                "NameLost",
-                                &n);
+                                "NameLost");
 
         } else if (streq(new_owner, a->unique_name)) {
 
                 r = sd_bus_message_new_signal(
                                 b,
+                                &n,
                                 "/org/freedesktop/DBus",
                                 "org.freedesktop.DBus",
-                                "NameAcquired",
-                                &n);
+                                "NameAcquired");
         } else
                 return 0;
 
@@ -250,46 +311,678 @@ static int synthesize_name_acquired(sd_bus *a, sd_bus *b, sd_bus_message *m) {
         return sd_bus_send(b, n, NULL);
 }
 
-static int process_policy(sd_bus *a, sd_bus *b, sd_bus_message *m) {
-        _cleanup_bus_message_unref_ sd_bus_message *n = NULL;
+static int synthetic_driver_send(sd_bus *b, sd_bus_message *m) {
         int r;
 
-        assert(a);
         assert(b);
         assert(m);
 
-        if (!sd_bus_message_is_method_call(m, "org.freedesktop.DBus.Properties", "GetAll"))
-                return 0;
+        r = bus_message_append_sender(m, "org.freedesktop.DBus");
+        if (r < 0)
+                return r;
 
-        if (!streq_ptr(m->path, "/org/gnome/DisplayManager/Slave"))
+        r = bus_seal_synthetic_message(b, m);
+        if (r < 0)
+                return r;
+
+        return sd_bus_send(b, m, NULL);
+}
+
+static int synthetic_reply_method_error(sd_bus_message *call, const sd_bus_error *e) {
+        _cleanup_bus_message_unref_ sd_bus_message *m = NULL;
+        int r;
+
+        assert(call);
+
+        if (call->header->flags & BUS_MESSAGE_NO_REPLY_EXPECTED)
                 return 0;
 
-        r = sd_bus_message_new_method_errorf(m, &n, SD_BUS_ERROR_ACCESS_DENIED, "gdm, you are stupid");
+        r = sd_bus_message_new_method_error(call, &m, e);
         if (r < 0)
                 return r;
 
-        r = bus_message_append_sender(n, "org.freedesktop.DBus");
-        if (r < 0) {
-                log_error("Failed to append sender to gdm reply: %s", strerror(-r));
+        return synthetic_driver_send(call->bus, m);
+}
+
+static int synthetic_reply_method_errno(sd_bus_message *call, int error, const sd_bus_error *p) {
+
+        _cleanup_bus_error_free_ sd_bus_error berror = SD_BUS_ERROR_NULL;
+
+        assert(call);
+
+        if (call->header->flags & BUS_MESSAGE_NO_REPLY_EXPECTED)
+                return 0;
+
+        if (sd_bus_error_is_set(p))
+                return synthetic_reply_method_error(call, p);
+
+        sd_bus_error_set_errno(&berror, error);
+
+        return synthetic_reply_method_error(call, &berror);
+}
+
+static int synthetic_reply_method_return(sd_bus_message *call, const char *types, ...) {
+        _cleanup_bus_message_unref_ sd_bus_message *m = NULL;
+        int r;
+
+        assert(call);
+
+        if (call->header->flags & BUS_MESSAGE_NO_REPLY_EXPECTED)
+                return 0;
+
+        r = sd_bus_message_new_method_return(call, &m);
+        if (r < 0)
                 return r;
+
+        if (!isempty(types)) {
+                va_list ap;
+
+                va_start(ap, types);
+                r = bus_message_append_ap(m, types, ap);
+                va_end(ap);
+                if (r < 0)
+                        return r;
         }
 
-        r = bus_seal_synthetic_message(b, n);
-        if (r < 0) {
-                log_error("Failed to seal gdm reply: %s", strerror(-r));
+        return synthetic_driver_send(call->bus, m);
+}
+
+static int synthetic_reply_return_strv(sd_bus_message *call, char **l) {
+        _cleanup_bus_message_unref_ sd_bus_message *m = NULL;
+        int r;
+
+        assert(call);
+
+        r = sd_bus_message_new_method_return(call, &m);
+        if (r < 0)
+                return synthetic_reply_method_errno(call, r, NULL);
+
+        r = sd_bus_message_append_strv(m, l);
+        if (r < 0)
+                return synthetic_reply_method_errno(call, r, NULL);
+
+        return synthetic_driver_send(call->bus, m);
+}
+
+static int get_creds_by_name(sd_bus *bus, const char *name, uint64_t mask, sd_bus_creds **_creds, sd_bus_error *error) {
+        _cleanup_bus_creds_unref_ sd_bus_creds *c = NULL;
+        int r;
+
+        assert(bus);
+        assert(name);
+        assert(_creds);
+
+        assert_return(service_name_is_valid(name), -EINVAL);
+
+        r = sd_bus_get_name_creds(bus, name, mask, &c);
+        if (r == -ESRCH || r == -ENXIO)
+                return sd_bus_error_setf(error, SD_BUS_ERROR_NAME_HAS_NO_OWNER, "Name %s is currently not owned by anyone.", name);
+        if (r < 0)
                 return r;
-        }
 
-        r = sd_bus_send(b, n, NULL);
-        if (r < 0) {
-                log_error("Failed to send gdm reply: %s", strerror(-r));
+        if ((c->mask & mask) != mask)
+                return -ENOTSUP;
+
+        *_creds = c;
+        c = NULL;
+
+        return 0;
+}
+
+static int get_creds_by_message(sd_bus *bus, sd_bus_message *m, uint64_t mask, sd_bus_creds **_creds, sd_bus_error *error) {
+        const char *name;
+        int r;
+
+        assert(bus);
+        assert(m);
+        assert(_creds);
+
+        r = sd_bus_message_read(m, "s", &name);
+        if (r < 0)
                 return r;
-        }
 
-        return 1;
+        return get_creds_by_name(bus, name, mask, _creds, error);
+}
+
+static int peer_is_privileged(sd_bus *bus, sd_bus_message *m) {
+        _cleanup_bus_creds_unref_ sd_bus_creds *creds = NULL;
+        uid_t uid;
+        int r;
+
+        r = get_creds_by_message(bus, m, SD_BUS_CREDS_UID, &creds, NULL);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_creds_get_uid(creds, &uid);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_creds_has_effective_cap(creds, CAP_SYS_ADMIN);
+        if (r > 0)
+                return true;
+
+        if (uid == getuid())
+                return true;
+
+        return false;
+}
+
+static int process_policy(sd_bus *a, sd_bus *b, sd_bus_message *m, Policy *policy, const struct ucred *ucred) {
+        int r;
+        char **names_strv;
+
+        assert(a);
+        assert(b);
+        assert(m);
+
+        if (a->is_kernel)
+                return 0;
+
+        r = sd_bus_creds_get_well_known_names(&m->creds, &names_strv);
+        if (r < 0)
+                return r;
+
+        if (!policy_check_recv(policy, ucred, names_hash, m->header->type, m->path, m->interface, m->member))
+                return -EPERM;
+
+        if (!policy_check_send(policy, ucred, names_strv, m->header->type, m->path, m->interface, m->member))
+                return -EPERM;
+
+        return 0;
 }
 
-static int process_hello(sd_bus *a, sd_bus *b, sd_bus_message *m, bool *got_hello) {
+static int process_driver(sd_bus *a, sd_bus *b, sd_bus_message *m, Policy *policy, const struct ucred *ucred) {
+        int r;
+
+        assert(a);
+        assert(b);
+        assert(m);
+
+        if (!a->is_kernel)
+                return 0;
+
+        if (!streq_ptr(sd_bus_message_get_destination(m), "org.freedesktop.DBus"))
+                return 0;
+
+        if (sd_bus_message_is_method_call(m, "org.freedesktop.DBus.Introspectable", "Introspect")) {
+                if (0 && !isempty(sd_bus_message_get_signature(m, true))) {
+                        _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
+
+                        r = sd_bus_error_setf(&error, SD_BUS_ERROR_INVALID_ARGS, "Expected no parameters");
+
+                        return synthetic_reply_method_errno(m, r, &error);
+                }
+
+                return synthetic_reply_method_return(m, "s",
+                        "<!DOCTYPE node PUBLIC \"-//freedesktop//DTD D-BUS Object Introspection 1.0//EN\" "
+                          "\"http://www.freedesktop.org/standards/dbus/1.0/introspect.dtd\">\n"
+                        "<node>\n"
+                        " <interface name=\"org.freedesktop.DBus.Introspectable\">\n"
+                        "  <method name=\"Introspect\">\n"
+                        "   <arg name=\"data\" type=\"s\" direction=\"out\"/>\n"
+                        "  </method>\n"
+                        " </interface>\n"
+                        " <interface name=\"org.freedesktop.DBus\">\n"
+                        "  <method name=\"AddMatch\">\n"
+                        "   <arg type=\"s\" direction=\"in\"/>\n"
+                        "  </method>\n"
+                        "  <method name=\"RemoveMatch\">\n"
+                        "   <arg type=\"s\" direction=\"in\"/>\n"
+                        "  </method>\n"
+                        "  <method name=\"GetConnectionSELinuxSecurityContext\">\n"
+                        "   <arg type=\"s\" direction=\"in\"/>\n"
+                        "   <arg type=\"ay\" direction=\"out\"/>\n"
+                        "  </method>\n"
+                        "  <method name=\"GetConnectionUnixProcessID\">\n"
+                        "   <arg type=\"s\" direction=\"in\"/>\n"
+                        "   <arg type=\"u\" direction=\"out\"/>\n"
+                        "  </method>\n"
+                        "  <method name=\"GetConnectionUnixUser\">\n"
+                        "   <arg type=\"s\" direction=\"in\"/>\n"
+                        "   <arg type=\"u\" direction=\"out\"/>\n"
+                        "  </method>\n"
+                        "  <method name=\"GetId\">\n"
+                        "   <arg type=\"s\" direction=\"out\"/>\n"
+                        "  </method>\n"
+                        "  <method name=\"GetNameOwner\">\n"
+                        "   <arg type=\"s\" direction=\"in\"/>\n"
+                        "   <arg type=\"s\" direction=\"out\"/>\n"
+                        "  </method>\n"
+                        "  <method name=\"Hello\">\n"
+                        "   <arg type=\"s\" direction=\"out\"/>\n"
+                        "  </method>\n"
+                        "  <method name=\"ListActivatableNames\">\n"
+                        "   <arg type=\"as\" direction=\"out\"/>\n"
+                        "  </method>\n"
+                        "  <method name=\"ListNames\">\n"
+                        "   <arg type=\"as\" direction=\"out\"/>\n"
+                        "  </method>\n"
+                        "  <method name=\"ListQueuedOwners\">\n"
+                        "   <arg type=\"s\" direction=\"in\"/>\n"
+                        "   <arg type=\"as\" direction=\"out\"/>\n"
+                        "  </method>\n"
+                        "  <method name=\"NameHasOwner\">\n"
+                        "   <arg type=\"s\" direction=\"in\"/>\n"
+                        "   <arg type=\"b\" direction=\"out\"/>\n"
+                        "  </method>\n"
+                        "  <method name=\"ReleaseName\">\n"
+                        "   <arg type=\"s\" direction=\"in\"/>\n"
+                        "   <arg type=\"u\" direction=\"out\"/>\n"
+                        "  </method>\n"
+                        "  <method name=\"ReloadConfig\">\n"
+                        "  </method>\n"
+                        "  <method name=\"RequestName\">\n"
+                        "   <arg type=\"s\" direction=\"in\"/>\n"
+                        "   <arg type=\"u\" direction=\"in\"/>\n"
+                        "   <arg type=\"u\" direction=\"out\"/>\n"
+                        "  </method>\n"
+                        "  <method name=\"StartServiceByName\">\n"
+                        "   <arg type=\"s\" direction=\"in\"/>\n"
+                        "   <arg type=\"u\" direction=\"in\"/>\n"
+                        "   <arg type=\"u\" direction=\"out\"/>\n"
+                        "  </method>\n"
+                        "  <method name=\"UpdateActivationEnvironment\">\n"
+                        "   <arg type=\"a{ss}\" direction=\"in\"/>\n"
+                        "  </method>\n"
+                        "  <signal name=\"NameAcquired\">\n"
+                        "   <arg type=\"s\"/>\n"
+                        "  </signal>\n"
+                        "  <signal name=\"NameLost\">\n"
+                        "   <arg type=\"s\"/>\n"
+                        "  </signal>\n"
+                        "  <signal name=\"NameOwnerChanged\">\n"
+                        "   <arg type=\"s\"/>\n"
+                        "   <arg type=\"s\"/>\n"
+                        "   <arg type=\"s\"/>\n"
+                        "  </signal>\n"
+                        " </interface>\n"
+                        "</node>\n");
+
+        } else if (sd_bus_message_is_method_call(m, "org.freedesktop.DBus", "AddMatch")) {
+                const char *match;
+
+                r = sd_bus_message_read(m, "s", &match);
+                if (r < 0)
+                        return synthetic_reply_method_errno(m, r, NULL);
+
+                r = sd_bus_add_match(a, NULL, match, NULL, NULL);
+                if (r < 0)
+                        return synthetic_reply_method_errno(m, r, NULL);
+
+                return synthetic_reply_method_return(m, NULL);
+
+        } else if (sd_bus_message_is_method_call(m, "org.freedesktop.DBus", "RemoveMatch")) {
+                const char *match;
+
+                r = sd_bus_message_read(m, "s", &match);
+                if (r < 0)
+                        return synthetic_reply_method_errno(m, r, NULL);
+
+                r = bus_remove_match_by_string(a, match, NULL, NULL);
+                if (r == 0)
+                        return synthetic_reply_method_error(m, &SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_MATCH_RULE_NOT_FOUND, "Match rule not found"));
+                if (r < 0)
+                        return synthetic_reply_method_errno(m, r, NULL);
+
+                return synthetic_reply_method_return(m, NULL);
+
+        } else if (sd_bus_message_is_method_call(m, "org.freedesktop.DBus", "GetConnectionSELinuxSecurityContext")) {
+                _cleanup_bus_creds_unref_ sd_bus_creds *creds = NULL;
+                _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
+
+                r = get_creds_by_message(a, m, SD_BUS_CREDS_SELINUX_CONTEXT, &creds, &error);
+                if (r < 0)
+                        return synthetic_reply_method_errno(m, r, &error);
+
+                return synthetic_reply_method_return(m, "y", creds->label, strlen(creds->label));
+
+        } else if (sd_bus_message_is_method_call(m, "org.freedesktop.DBus", "GetConnectionUnixProcessID")) {
+                _cleanup_bus_creds_unref_ sd_bus_creds *creds = NULL;
+                _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
+
+                r = get_creds_by_message(a, m, SD_BUS_CREDS_PID, &creds, &error);
+                if (r < 0)
+                        return synthetic_reply_method_errno(m, r, &error);
+
+                return synthetic_reply_method_return(m, "u", (uint32_t) creds->pid);
+
+        } else if (sd_bus_message_is_method_call(m, "org.freedesktop.DBus", "GetConnectionUnixUser")) {
+                _cleanup_bus_creds_unref_ sd_bus_creds *creds = NULL;
+                _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
+
+                r = get_creds_by_message(a, m, SD_BUS_CREDS_UID, &creds, &error);
+                if (r < 0)
+                        return synthetic_reply_method_errno(m, r, &error);
+
+                return synthetic_reply_method_return(m, "u", (uint32_t) creds->uid);
+
+        } else if (sd_bus_message_is_method_call(m, "org.freedesktop.DBus", "GetId")) {
+                sd_id128_t server_id;
+                char buf[SD_ID128_STRING_MAX];
+
+                r = sd_bus_get_owner_id(a, &server_id);
+                if (r < 0)
+                        return synthetic_reply_method_errno(m, r, NULL);
+
+                return synthetic_reply_method_return(m, "s", sd_id128_to_string(server_id, buf));
+
+        } else if (sd_bus_message_is_method_call(m, "org.freedesktop.DBus", "GetNameOwner")) {
+                const char *name;
+                _cleanup_bus_creds_unref_ sd_bus_creds *creds = NULL;
+                _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
+
+                r = sd_bus_message_read(m, "s", &name);
+                if (r < 0)
+                        return synthetic_reply_method_errno(m, r, NULL);
+
+                if (streq(name, "org.freedesktop.DBus"))
+                        return synthetic_reply_method_return(m, "s", "org.freedesktop.DBus");
+
+                r = get_creds_by_name(a, name, SD_BUS_CREDS_UNIQUE_NAME, &creds, &error);
+                if (r < 0)
+                        return synthetic_reply_method_errno(m, r, &error);
+
+                return synthetic_reply_method_return(m, "s", creds->unique_name);
+
+        /* "Hello" is handled in process_hello() */
+
+        } else if (sd_bus_message_is_method_call(m, "org.freedesktop.DBus", "ListActivatableNames")) {
+                _cleanup_strv_free_ char **names = NULL;
+
+                r = sd_bus_list_names(a, NULL, &names);
+                if (r < 0)
+                        return synthetic_reply_method_errno(m, r, NULL);
+
+                /* Let's sort the names list to make it stable */
+                strv_sort(names);
+
+                return synthetic_reply_return_strv(m, names);
+
+        } else if (sd_bus_message_is_method_call(m, "org.freedesktop.DBus", "ListNames")) {
+                _cleanup_strv_free_ char **names = NULL;
+
+                r = sd_bus_list_names(a, &names, NULL);
+                if (r < 0)
+                        return synthetic_reply_method_errno(m, r, NULL);
+
+                r = strv_extend(&names, "org.freedesktop.DBus");
+                if (r < 0)
+                        return synthetic_reply_method_errno(m, r, NULL);
+
+                /* Let's sort the names list to make it stable */
+                strv_sort(names);
+
+                return synthetic_reply_return_strv(m, names);
+
+        } else if (sd_bus_message_is_method_call(m, "org.freedesktop.DBus", "ListQueuedOwners")) {
+                struct kdbus_cmd_name_list cmd = {};
+                struct kdbus_name_list *name_list;
+                struct kdbus_cmd_free cmd_free;
+                struct kdbus_name_info *name;
+                _cleanup_strv_free_ char **owners = NULL;
+                _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
+                char *arg0;
+                int err = 0;
+
+                r = sd_bus_message_read(m, "s", &arg0);
+                if (r < 0)
+                        return synthetic_reply_method_errno(m, r, NULL);
+
+                if (!service_name_is_valid(arg0))
+                        return synthetic_reply_method_errno(m, -EINVAL, NULL);
+
+                r = sd_bus_get_name_creds(a, arg0, 0, NULL);
+                if (r == -ESRCH || r == -ENXIO) {
+                        sd_bus_error_setf(&error, SD_BUS_ERROR_NAME_HAS_NO_OWNER, "Could not get owners of name '%s': no such name.", arg0);
+                        return synthetic_reply_method_errno(m, r, &error);
+                }
+                if (r < 0)
+                        return synthetic_reply_method_errno(m, r, NULL);
+
+                cmd.flags = KDBUS_NAME_LIST_QUEUED;
+                r = ioctl(a->input_fd, KDBUS_CMD_NAME_LIST, &cmd);
+                if (r < 0)
+                        return synthetic_reply_method_errno(m, -errno, NULL);
+
+                name_list = (struct kdbus_name_list *) ((uint8_t *) a->kdbus_buffer + cmd.offset);
+
+                KDBUS_ITEM_FOREACH(name, name_list, names) {
+                        const char *entry_name = NULL;
+                        struct kdbus_item *item;
+                        char *n;
+
+                        KDBUS_ITEM_FOREACH(item, name, items)
+                                if (item->type == KDBUS_ITEM_OWNED_NAME)
+                                        entry_name = item->name.name;
+
+                        if (!streq_ptr(entry_name, arg0))
+                                continue;
+
+                        if (asprintf(&n, ":1.%llu", (unsigned long long) name->owner_id) < 0) {
+                                err  = -ENOMEM;
+                                break;
+                        }
+
+                        r = strv_consume(&owners, n);
+                        if (r < 0) {
+                                err = r;
+                                break;
+                        }
+                }
+
+                cmd_free.flags = 0;
+                cmd_free.offset = cmd.offset;
+
+                r = ioctl(a->input_fd, KDBUS_CMD_FREE, &cmd_free);
+                if (r < 0)
+                        return synthetic_reply_method_errno(m, r, NULL);
+
+                if (err < 0)
+                        return synthetic_reply_method_errno(m, err, NULL);
+
+                return synthetic_reply_return_strv(m, owners);
+
+        } else if (sd_bus_message_is_method_call(m, "org.freedesktop.DBus", "NameHasOwner")) {
+                const char *name;
+
+                r = sd_bus_message_read(m, "s", &name);
+                if (r < 0)
+                        return synthetic_reply_method_errno(m, r, NULL);
+
+                if (!service_name_is_valid(name))
+                        return synthetic_reply_method_errno(m, -EINVAL, NULL);
+
+                if (streq(name, "org.freedesktop.DBus"))
+                        return synthetic_reply_method_return(m, "b", true);
+
+                r = sd_bus_get_name_creds(a, name, 0, NULL);
+                if (r < 0 && r != -ESRCH && r != -ENXIO)
+                        return synthetic_reply_method_errno(m, r, NULL);
+
+                return synthetic_reply_method_return(m, "b", r >= 0);
+
+        } else if (sd_bus_message_is_method_call(m, "org.freedesktop.DBus", "ReleaseName")) {
+                const char *name;
+
+                r = sd_bus_message_read(m, "s", &name);
+                if (r < 0)
+                        return synthetic_reply_method_errno(m, r, NULL);
+
+                if (!service_name_is_valid(name))
+                        return synthetic_reply_method_errno(m, -EINVAL, NULL);
+
+                r = sd_bus_release_name(a, name);
+                if (r < 0) {
+                        if (r == -ESRCH)
+                                return synthetic_reply_method_return(m, "u", BUS_NAME_NON_EXISTENT);
+                        if (r == -EADDRINUSE)
+                                return synthetic_reply_method_return(m, "u", BUS_NAME_NOT_OWNER);
+
+                        return synthetic_reply_method_errno(m, r, NULL);
+                }
+
+                hashmap_remove(names_hash, name);
+
+                return synthetic_reply_method_return(m, "u", BUS_NAME_RELEASED);
+
+        } else if (sd_bus_message_is_method_call(m, "org.freedesktop.DBus", "ReloadConfig")) {
+                _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
+
+                r = sd_bus_error_setf(&error, SD_BUS_ERROR_NOT_SUPPORTED, "%s() is not supported", sd_bus_message_get_member(m));
+
+                return synthetic_reply_method_errno(m, r, &error);
+
+        } else if (sd_bus_message_is_method_call(m, "org.freedesktop.DBus", "RequestName")) {
+                const char *name;
+                uint32_t flags, param;
+                bool in_queue;
+
+                r = sd_bus_message_read(m, "su", &name, &flags);
+                if (r < 0)
+                        return synthetic_reply_method_errno(m, r, NULL);
+
+                if (!policy_check_own(policy, ucred, name))
+                        return synthetic_reply_method_errno(m, -EPERM, NULL);
+
+                if (!service_name_is_valid(name))
+                        return synthetic_reply_method_errno(m, -EINVAL, NULL);
+                if ((flags & ~(BUS_NAME_ALLOW_REPLACEMENT|BUS_NAME_REPLACE_EXISTING|BUS_NAME_DO_NOT_QUEUE)) != 0)
+                        return synthetic_reply_method_errno(m, -EINVAL, NULL);
+
+                param = 0;
+                if (flags & BUS_NAME_ALLOW_REPLACEMENT)
+                        param |= SD_BUS_NAME_ALLOW_REPLACEMENT;
+                if (flags & BUS_NAME_REPLACE_EXISTING)
+                        param |= SD_BUS_NAME_REPLACE_EXISTING;
+                if (!(flags & BUS_NAME_DO_NOT_QUEUE))
+                        param |= SD_BUS_NAME_QUEUE;
+
+                r = sd_bus_request_name(a, name, param);
+                if (r < 0) {
+                        if (r == -EEXIST)
+                                return synthetic_reply_method_return(m, "u", BUS_NAME_EXISTS);
+                        if (r == -EALREADY)
+                                return synthetic_reply_method_return(m, "u", BUS_NAME_ALREADY_OWNER);
+                        return synthetic_reply_method_errno(m, r, NULL);
+                }
+
+                in_queue = (r == 0);
+
+                r = hashmap_put(names_hash, name, NULL);
+                if (r < 0)
+                        return synthetic_reply_method_errno(m, r, NULL);
+
+                if (in_queue)
+                        return synthetic_reply_method_return(m, "u", BUS_NAME_IN_QUEUE);
+
+                return synthetic_reply_method_return(m, "u", BUS_NAME_PRIMARY_OWNER);
+
+        } else if (sd_bus_message_is_method_call(m, "org.freedesktop.DBus", "StartServiceByName")) {
+                _cleanup_bus_message_unref_ sd_bus_message *msg = NULL;
+                const char *name;
+                uint32_t flags;
+
+                r = sd_bus_message_read(m, "su", &name, &flags);
+                if (r < 0)
+                        return synthetic_reply_method_errno(m, r, NULL);
+
+                if (!service_name_is_valid(name))
+                        return synthetic_reply_method_errno(m, -EINVAL, NULL);
+                if (flags != 0)
+                        return synthetic_reply_method_errno(m, -EINVAL, NULL);
+
+                r = sd_bus_get_name_creds(a, name, 0, NULL);
+                if (r >= 0 || streq(name, "org.freedesktop.DBus"))
+                        return synthetic_reply_method_return(m, "u", BUS_START_REPLY_ALREADY_RUNNING);
+                if (r != -ESRCH)
+                        return synthetic_reply_method_errno(m, r, NULL);
+
+                r = sd_bus_message_new_method_call(
+                                a,
+                                &msg,
+                                name,
+                                "/",
+                                "org.freedesktop.DBus.Peer",
+                                "Ping");
+                if (r < 0)
+                        return synthetic_reply_method_errno(m, r, NULL);
+
+                r = sd_bus_send(a, msg, NULL);
+                if (r < 0)
+                        return synthetic_reply_method_errno(m, r, NULL);
+
+                return synthetic_reply_method_return(m, "u", BUS_START_REPLY_SUCCESS);
+
+        } else if (sd_bus_message_is_method_call(m, "org.freedesktop.DBus", "UpdateActivationEnvironment")) {
+                _cleanup_bus_message_unref_ sd_bus_message *msg = NULL;
+                _cleanup_strv_free_ char **args = NULL;
+
+                if (!peer_is_privileged(a, m))
+                        return synthetic_reply_method_errno(m, -EPERM, NULL);
+
+                r = sd_bus_message_enter_container(m, SD_BUS_TYPE_ARRAY, "{ss}");
+                if (r < 0)
+                        return synthetic_reply_method_errno(m, r, NULL);
+
+                while ((r = sd_bus_message_enter_container(m, SD_BUS_TYPE_DICT_ENTRY, "ss")) > 0) {
+                        _cleanup_free_ char *s = NULL;
+                        const char *key;
+                        const char *value;
+
+                        r = sd_bus_message_read(m, "ss", &key, &value);
+                        if (r < 0)
+                                return synthetic_reply_method_errno(m, r, NULL);
+
+                        s = strjoin(key, "=", value, NULL);
+                        if (!s)
+                                return synthetic_reply_method_errno(m, -ENOMEM, NULL);
+
+                        r  = strv_extend(&args, s);
+                        if (r < 0)
+                                return synthetic_reply_method_errno(m, r, NULL);
+
+                        r = sd_bus_message_exit_container(m);
+                        if (r < 0)
+                                return synthetic_reply_method_errno(m, r, NULL);
+                }
+
+                r = sd_bus_message_exit_container(m);
+                if (r < 0)
+                        return synthetic_reply_method_errno(m, r, NULL);
+
+                if (!args)
+                        return synthetic_reply_method_errno(m, -EINVAL, NULL);
+
+                r = sd_bus_message_new_method_call(
+                                a,
+                                &msg,
+                                "org.freedesktop.systemd1",
+                                "/org/freedesktop/systemd1",
+                                "org.freedesktop.systemd1.Manager",
+                                "SetEnvironment");
+                if (r < 0)
+                        return synthetic_reply_method_errno(m, r, NULL);
+
+                r = sd_bus_message_append_strv(msg, args);
+                if (r < 0)
+                        return synthetic_reply_method_errno(m, r, NULL);
+
+                r = sd_bus_call(a, msg, 0, NULL, NULL);
+                if (r < 0)
+                        return synthetic_reply_method_errno(m, r, NULL);
+
+               return synthetic_reply_method_return(m, NULL);
+
+        } else {
+                _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
+
+                r = sd_bus_error_setf(&error, SD_BUS_ERROR_UNKNOWN_METHOD, "Unknown method '%s'.", m->member);
+
+                return synthetic_reply_method_errno(m, r, &error);
+        }
+}
+
+static int process_hello(sd_bus *a, sd_bus *b, sd_bus_message *m, Policy *policy, const struct ucred *ucred, bool *got_hello) {
         _cleanup_bus_message_unref_ sd_bus_message *n = NULL;
         bool is_hello;
         int r;
@@ -321,6 +1014,11 @@ static int process_hello(sd_bus *a, sd_bus *b, sd_bus_message *m, bool *got_hell
                 return -EIO;
         }
 
+        if (!policy_check_hello(policy, ucred)) {
+                log_error("Policy denied HELLO");
+                return -EPERM;
+        }
+
         *got_hello = true;
 
         if (!a->is_kernel)
@@ -359,10 +1057,10 @@ static int process_hello(sd_bus *a, sd_bus *b, sd_bus_message *m, bool *got_hell
         n = sd_bus_message_unref(n);
         r = sd_bus_message_new_signal(
                         b,
+                        &n,
                         "/org/freedesktop/DBus",
                         "org.freedesktop.DBus",
-                        "NameAcquired",
-                        &n);
+                        "NameAcquired");
         if (r < 0) {
                 log_error("Failed to allocate initial NameAcquired message: %s", strerror(-r));
                 return r;
@@ -395,15 +1093,46 @@ static int process_hello(sd_bus *a, sd_bus *b, sd_bus_message *m, bool *got_hell
         return 1;
 }
 
+static int patch_sender(sd_bus *a, sd_bus_message *m) {
+        char **well_known = NULL;
+        sd_bus_creds *c;
+        int r;
+
+        assert(a);
+        assert(m);
+
+        if (!a->is_kernel)
+                return 0;
+
+        /* We will change the sender of messages from the bus driver
+         * so that they originate from the bus driver. This is a
+         * speciality originating from dbus1, where the bus driver did
+         * not have a unique id, but only the well-known name. */
+
+        c = sd_bus_message_get_creds(m);
+        if (!c)
+                return 0;
+
+        r = sd_bus_creds_get_well_known_names(c, &well_known);
+        if (r < 0)
+                return r;
+
+        if (strv_contains(well_known, "org.freedesktop.DBus"))
+                m->sender = "org.freedesktop.DBus";
+
+        return 0;
+}
+
 int main(int argc, char *argv[]) {
 
-        _cleanup_bus_unref_ sd_bus *a = NULL, *b = NULL;
+        _cleanup_bus_close_unref_ sd_bus *a = NULL, *b = NULL;
         sd_id128_t server_id;
         int r, in_fd, out_fd;
         bool got_hello = false;
         bool is_unix;
         struct ucred ucred = {};
         _cleanup_free_ char *peersec = NULL;
+        Policy policy = {};
 
         log_set_target(LOG_TARGET_JOURNAL_OR_KMSG);
         log_parse_environment();
@@ -413,6 +1142,14 @@ int main(int argc, char *argv[]) {
         if (r <= 0)
                 goto finish;
 
+        r = policy_load(&policy, arg_configuration);
+        if (r < 0) {
+                log_error("Failed to load policy: %s", strerror(-r));
+                goto finish;
+        }
+
+        /* policy_dump(&policy); */
+
         r = sd_listen_fds(0);
         if (r == 0) {
                 in_fd = STDIN_FILENO;
@@ -430,8 +1167,30 @@ int main(int argc, char *argv[]) {
                 sd_is_socket(out_fd, AF_UNIX, 0, 0) > 0;
 
         if (is_unix) {
-                getpeercred(in_fd, &ucred);
-                getpeersec(in_fd, &peersec);
+                (void) getpeercred(in_fd, &ucred);
+                (void) getpeersec(in_fd, &peersec);
+        }
+
+        if (arg_drop_privileges) {
+                const char *user = "systemd-bus-proxy";
+                uid_t uid;
+                gid_t gid;
+
+                r = get_user_creds(&user, &uid, &gid, NULL, NULL);
+                if (r < 0) {
+                        log_error("Cannot resolve user name %s: %s", user, strerror(-r));
+                        goto finish;
+                }
+
+                r = drop_privileges(uid, gid, 1ULL << CAP_IPC_OWNER);
+                if (r < 0)
+                        goto finish;
+        }
+
+        names_hash = hashmap_new(&string_hash_ops);
+        if (!names_hash) {
+                log_oom();
+                goto finish;
         }
 
         r = sd_bus_new(&a);
@@ -440,7 +1199,7 @@ int main(int argc, char *argv[]) {
                 goto finish;
         }
 
-        r = sd_bus_set_name(a, "sd-proxy");
+        r = sd_bus_set_description(a, "sd-proxy");
         if (r < 0) {
                 log_error("Failed to set bus name: %s", strerror(-r));
                 goto finish;
@@ -465,11 +1224,10 @@ int main(int argc, char *argv[]) {
                 a->fake_creds_valid = true;
         }
 
-        /* FIXME: faking security labels is broken in kdbus right now */
-        /* if (peersec) { */
-        /*         a->fake_label = peersec; */
-        /*         peersec = NULL; */
-        /* } */
+        if (peersec) {
+                a->fake_label = peersec;
+                peersec = NULL;
+        }
 
         a->manual_peer_interface = true;
 
@@ -479,7 +1237,7 @@ int main(int argc, char *argv[]) {
                 goto finish;
         }
 
-        r = sd_bus_get_server_id(a, &server_id);
+        r = sd_bus_get_owner_id(a, &server_id);
         if (r < 0) {
                 log_error("Failed to get server ID: %s", strerror(-r));
                 goto finish;
@@ -551,7 +1309,7 @@ int main(int argc, char *argv[]) {
                         goto finish;
                 }
 
-                r = sd_bus_add_match(a, match, NULL, NULL);
+                r = sd_bus_add_match(a, NULL, match, NULL, NULL);
                 if (r < 0) {
                         log_error("Failed to add match for NameLost: %s", strerror(-r));
                         goto finish;
@@ -572,7 +1330,7 @@ int main(int argc, char *argv[]) {
                         goto finish;
                 }
 
-                r = sd_bus_add_match(a, match, NULL, NULL);
+                r = sd_bus_add_match(a, NULL, match, NULL, NULL);
                 if (r < 0) {
                         log_error("Failed to add match for NameAcquired: %s", strerror(-r));
                         goto finish;
@@ -613,6 +1371,8 @@ int main(int argc, char *argv[]) {
                                         goto finish;
                                 }
 
+                                patch_sender(a, m);
+
                                 k = sd_bus_send(b, m, NULL);
                                 if (k < 0) {
                                         if (k == -ECONNRESET)
@@ -648,7 +1408,7 @@ int main(int argc, char *argv[]) {
                                 goto finish;
                         }
 
-                        k = process_hello(a, b, m, &got_hello);
+                        k = process_hello(a, b, m, &policy, &ucred, &got_hello);
                         if (k < 0) {
                                 r = k;
                                 log_error("Failed to process HELLO: %s", strerror(-r));
@@ -658,23 +1418,34 @@ int main(int argc, char *argv[]) {
                         if (k > 0)
                                 r = k;
                         else {
-                                k = process_policy(a, b, m);
+                                k = process_driver(a, b, m, &policy, &ucred);
                                 if (k < 0) {
                                         r = k;
-                                        log_error("Failed to process policy: %s", strerror(-r));
+                                        log_error("Failed to process driver calls: %s", strerror(-r));
                                         goto finish;
                                 }
 
-                                k = sd_bus_send(a, m, NULL);
-                                if (k < 0) {
-                                        if (r == -ECONNRESET)
-                                                r = 0;
-                                        else {
+                                if (k > 0)
+                                        r = k;
+                                else {
+                                        k = process_policy(a, b, m, &policy, &ucred);
+                                        if (k < 0) {
                                                 r = k;
-                                                log_error("Failed to send message: %s", strerror(-r));
+                                                log_error("Failed to process policy: %s", strerror(-r));
+                                                goto finish;
                                         }
 
-                                        goto finish;
+                                        k = sd_bus_send(a, m, NULL);
+                                        if (k < 0) {
+                                                if (k == -ECONNRESET)
+                                                        r = 0;
+                                                else {
+                                                        r = k;
+                                                        log_error("Failed to send message: %s", strerror(-r));
+                                                }
+
+                                                goto finish;
+                                        }
                                 }
                         }
                 }
@@ -743,11 +1514,15 @@ int main(int argc, char *argv[]) {
                 }
         }
 
-        r = 0;
-
 finish:
-        sd_bus_flush(a);
-        sd_bus_flush(b);
+        sd_notify(false,
+                  "STOPPING=1\n"
+                  "STATUS=Shutting down.");
+
+        policy_free(&policy);
+        strv_free(arg_configuration);
+        hashmap_free(names_hash);
+        free(arg_address);
 
         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 }