chiark / gitweb /
tree-wide: spelling fixes
[elogind.git] / src / bus-proxyd / bus-proxyd.c
index abc50143289ed79fe26d4a25bd5858ccd30c54c5..6d9e1a031cdde901c4221257e583c0d3c1287af1 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 "bus-util.h"
 #include "build.h"
 #include "strv.h"
-
-#define UNIX_BUS_PATH "unix:path=/run/dbus/system_bus_socket"
-#define KERNEL_BUS_PATH "kernel:path=/dev/kdbus/0-system/bus"
-
-#ifdef ENABLE_KDBUS
-#  define DEFAULT_BUS_PATH KERNEL_BUS_PATH ";" UNIX_BUS_PATH
-#else
-#  define DEFAULT_BUS_PATH UNIX_BUS_PATH
-#endif
-
-static const char *arg_address = DEFAULT_BUS_PATH;
+#include "def.h"
+#include "capability.h"
+#include "bus-control.h"
+#include "smack-util.h"
+#include "set.h"
+#include "bus-xml-policy.h"
+
+static char *arg_address = NULL;
 static char *arg_command_line_buffer = NULL;
+static bool arg_drop_privileges = false;
+static char **arg_configuration = 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_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_ADDRESS ")\n",
                program_invocation_short_name);
 
         return 0;
@@ -71,21 +75,27 @@ 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) {
 
@@ -98,32 +108,76 @@ 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;
 
                 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_ADDRESS);
+                if (!arg_address)
+                        return log_oom();
+        }
+
         return 1;
 }
 
-static int rename_service(sd_bus *b) {
+static int rename_service(sd_bus *a, sd_bus *b) {
         _cleanup_bus_creds_unref_ sd_bus_creds *creds = NULL;
         _cleanup_free_ char *p = NULL, *name = NULL;
         const char *comm;
@@ -132,9 +186,10 @@ static int rename_service(sd_bus *b) {
         pid_t pid;
         int r;
 
+        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;
 
@@ -164,9 +219,9 @@ static int rename_service(sd_bus *b) {
 
         /* The status string gets the full command line ... */
         sd_notifyf(false,
-                   "STATUS=Processing requests from client PID %lu (%s); UID %lu (%s)",
-                   (unsigned long) pid, p,
-                   (unsigned long) uid, name);
+                   "STATUS=Processing requests from client PID "PID_FMT" (%s); UID "UID_FMT" (%s)",
+                   pid, p,
+                   uid, name);
 
         /* ... and the argv line only the short comm */
         if (arg_command_line_buffer) {
@@ -174,17 +229,19 @@ static int rename_service(sd_bus *b) {
 
                 m = strlen(arg_command_line_buffer);
                 w = snprintf(arg_command_line_buffer, m,
-                             "[PID %lu/%s; UID %lu/%s]",
-                             (unsigned long) pid, comm,
-                             (unsigned long) uid, name);
+                             "[PID "PID_FMT"/%s; UID "UID_FMT"/%s]",
+                             pid, comm,
+                             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 %lu (%s), UID %lu (%s).",
-                   (unsigned long) pid, p,
-                   (unsigned long) uid, name);
+        log_debug("Running on behalf of PID "PID_FMT" (%s), UID "UID_FMT" (%s), %s",
+                  pid, p,
+                  uid, name,
+                  a->unique_name);
+
         return 0;
 }
 
@@ -221,19 +278,19 @@ 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;
 
@@ -255,6 +312,829 @@ static int synthesize_name_acquired(sd_bus *a, sd_bus *b, sd_bus_message *m) {
         return sd_bus_send(b, n, NULL);
 }
 
+static int synthetic_driver_send(sd_bus *b, sd_bus_message *m) {
+        int r;
+
+        assert(b);
+        assert(m);
+
+        r = bus_message_append_sender(m, "org.freedesktop.DBus");
+        if (r < 0)
+                return r;
+
+        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_error(call, &m, e);
+        if (r < 0)
+                return r;
+
+        return synthetic_driver_send(call->bus, m);
+}
+
+static int synthetic_reply_method_errorf(sd_bus_message *call, const char *name, const char *format, ...) {
+        _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
+        va_list ap;
+
+        va_start(ap, format);
+        bus_error_setfv(&error, name, format, ap);
+        va_end(ap);
+
+        return synthetic_reply_method_error(call, &error);
+}
+
+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;
+        }
+
+        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);
+
+        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;
+
+        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 get_creds_by_name(bus, name, mask, _creds, error);
+}
+
+static int process_driver(sd_bus *a, sd_bus *b, sd_bus_message *m, Policy *policy, const struct ucred *ucred, Set *owned_names) {
+        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;
+
+        /* The "Hello()" call is is handled in process_hello() */
+
+        if (sd_bus_message_is_method_call(m, "org.freedesktop.DBus.Introspectable", "Introspect")) {
+
+                if (!sd_bus_message_has_signature(m, ""))
+                        return synthetic_reply_method_error(m, &SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_INVALID_ARGS, "Invalid parameters"));
+
+                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;
+
+                if (!sd_bus_message_has_signature(m, "s"))
+                        return synthetic_reply_method_error(m, &SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_INVALID_ARGS, "Invalid parameters"));
+
+                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;
+
+                if (!sd_bus_message_has_signature(m, "s"))
+                        return synthetic_reply_method_error(m, &SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_INVALID_ARGS, "Invalid parameters"));
+
+                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;
+
+                if (!sd_bus_message_has_signature(m, "s"))
+                        return synthetic_reply_method_error(m, &SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_INVALID_ARGS, "Invalid parameters"));
+
+                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;
+
+                if (!sd_bus_message_has_signature(m, "s"))
+                        return synthetic_reply_method_error(m, &SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_INVALID_ARGS, "Invalid parameters"));
+
+                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;
+
+                if (!sd_bus_message_has_signature(m, "s"))
+                        return synthetic_reply_method_error(m, &SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_INVALID_ARGS, "Invalid parameters"));
+
+                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];
+
+                if (!sd_bus_message_has_signature(m, ""))
+                        return synthetic_reply_method_error(m, &SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_INVALID_ARGS, "Invalid parameters"));
+
+                r = sd_bus_get_bus_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;
+
+                if (!sd_bus_message_has_signature(m, "s"))
+                        return synthetic_reply_method_error(m, &SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_INVALID_ARGS, "Invalid parameters"));
+
+                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);
+
+        } else if (sd_bus_message_is_method_call(m, "org.freedesktop.DBus", "ListActivatableNames")) {
+                _cleanup_strv_free_ char **names = NULL;
+
+                if (!sd_bus_message_has_signature(m, ""))
+                        return synthetic_reply_method_error(m, &SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_INVALID_ARGS, "Invalid parameters"));
+
+                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;
+
+                if (!sd_bus_message_has_signature(m, ""))
+                        return synthetic_reply_method_error(m, &SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_INVALID_ARGS, "Invalid parameters"));
+
+                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_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;
+
+                if (!sd_bus_message_has_signature(m, "s"))
+                        return synthetic_reply_method_error(m, &SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_INVALID_ARGS, "Invalid parameters"));
+
+                r = sd_bus_message_read(m, "s", &arg0);
+                if (r < 0)
+                        return synthetic_reply_method_errno(m, r, 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;
+                        }
+                }
+
+                r = bus_kernel_cmd_free(a, cmd.offset);
+                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;
+
+                if (!sd_bus_message_has_signature(m, "s"))
+                        return synthetic_reply_method_error(m, &SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_INVALID_ARGS, "Invalid parameters"));
+
+                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, "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;
+
+                if (!sd_bus_message_has_signature(m, "s"))
+                        return synthetic_reply_method_error(m, &SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_INVALID_ARGS, "Invalid parameters"));
+
+                r = sd_bus_message_read(m, "s", &name);
+                if (r < 0)
+                        return synthetic_reply_method_errno(m, r, 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);
+                }
+
+                set_remove(owned_names, (char*) 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;
+
+                if (!sd_bus_message_has_signature(m, ""))
+                        return synthetic_reply_method_error(m, &SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_INVALID_ARGS, "Invalid parameters"));
+
+                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;
+
+                if (!sd_bus_message_has_signature(m, "su"))
+                        return synthetic_reply_method_error(m, &SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_INVALID_ARGS, "Invalid parameters"));
+
+                r = sd_bus_message_read(m, "su", &name, &flags);
+                if (r < 0)
+                        return synthetic_reply_method_errno(m, r, NULL);
+
+                if (policy && !policy_check_own(policy, ucred->uid, ucred->gid, name))
+                        return synthetic_reply_method_errno(m, -EPERM, 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 = set_put_strdup(owned_names, name);
+                if (r < 0)
+                        return synthetic_reply_method_errno(m, r, NULL);
+
+                r = sd_bus_request_name(a, name, param);
+                if (r < 0) {
+                        if (r == -EALREADY)
+                                return synthetic_reply_method_return(m, "u", BUS_NAME_ALREADY_OWNER);
+
+                        set_remove(owned_names, (char*) name);
+
+                        if (r == -EEXIST)
+                                return synthetic_reply_method_return(m, "u", BUS_NAME_EXISTS);
+                        return synthetic_reply_method_errno(m, r, NULL);
+                }
+
+                in_queue = (r == 0);
+
+                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;
+
+                if (!sd_bus_message_has_signature(m, "su"))
+                        return synthetic_reply_method_error(m, &SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_INVALID_ARGS, "Invalid parameters"));
+
+                r = sd_bus_message_read(m, "su", &name, &flags);
+                if (r < 0)
+                        return synthetic_reply_method_errno(m, r, 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 (!sd_bus_message_has_signature(m, "a{ss}"))
+                        return synthetic_reply_method_error(m, &SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_INVALID_ARGS, "Invalid parameters"));
+
+                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 handle_policy_error(sd_bus_message *m, int r) {
+        if (r == -ESRCH || r == -ENXIO)
+                return synthetic_reply_method_errorf(m, SD_BUS_ERROR_NAME_HAS_NO_OWNER, "Name %s is currently not owned by anyone.", m->destination);
+
+        return r;
+}
+
+static int process_policy(sd_bus *from, sd_bus *to, sd_bus_message *m, Policy *policy, const struct ucred *our_ucred, Set *owned_names) {
+        int r;
+
+        assert(from);
+        assert(to);
+        assert(m);
+
+        if (!policy)
+                return 0;
+
+        if (from->is_kernel) {
+                uid_t sender_uid = UID_INVALID;
+                gid_t sender_gid = GID_INVALID;
+                char **sender_names = NULL;
+                bool granted = false;
+
+                /* Driver messages are always OK */
+                if (streq_ptr(m->sender, "org.freedesktop.DBus"))
+                        return 0;
+
+                /* The message came from the kernel, and is sent to our legacy client. */
+                sd_bus_creds_get_well_known_names(&m->creds, &sender_names);
+
+                (void) sd_bus_creds_get_uid(&m->creds, &sender_uid);
+                (void) sd_bus_creds_get_gid(&m->creds, &sender_gid);
+
+                /* First check whether the sender can send the message to our name */
+                if (set_isempty(owned_names)) {
+                        if (policy_check_send(policy, sender_uid, sender_gid, m->header->type, NULL, m->path, m->interface, m->member))
+                                granted = true;
+                } else {
+                        Iterator i;
+                        char *n;
+
+                        SET_FOREACH(n, owned_names, i)
+                                if (policy_check_send(policy, sender_uid, sender_gid, m->header->type, n, m->path, m->interface, m->member)) {
+                                        granted = true;
+                                        break;
+                                }
+                }
+
+                if (granted) {
+                        /* Then check whether us (the recipient) can receive from the sender's name */
+                        if (strv_isempty(sender_names)) {
+                                if (policy_check_recv(policy, our_ucred->uid, our_ucred->gid, m->header->type, NULL, m->path, m->interface, m->member))
+                                        return 0;
+                        } else {
+                                char **n;
+
+                                STRV_FOREACH(n, sender_names) {
+                                        if (policy_check_recv(policy, our_ucred->uid, our_ucred->gid, m->header->type, *n, m->path, m->interface, m->member))
+                                                return 0;
+                                }
+                        }
+                }
+
+                /* Return an error back to the caller */
+                if (m->header->type == SD_BUS_MESSAGE_METHOD_CALL)
+                        return synthetic_reply_method_errorf(m, SD_BUS_ERROR_ACCESS_DENIED, "Access prohibited by XML receiver policy.");
+
+                /* Return 1, indicating that the message shall not be processed any further */
+                return 1;
+        }
+
+        if (to->is_kernel) {
+                _cleanup_bus_creds_unref_ sd_bus_creds *destination_creds = NULL;
+                uid_t destination_uid = UID_INVALID;
+                gid_t destination_gid = GID_INVALID;
+                const char *destination_unique = NULL;
+                char **destination_names = NULL;
+                bool granted = false;
+
+                /* Driver messages are always OK */
+                if (streq_ptr(m->destination, "org.freedesktop.DBus"))
+                        return 0;
+
+                /* The message came from the legacy client, and is sent to kdbus. */
+                if (m->destination) {
+                        r = bus_get_name_creds_kdbus(to, m->destination,
+                                                     SD_BUS_CREDS_WELL_KNOWN_NAMES|SD_BUS_CREDS_UNIQUE_NAME|
+                                                     SD_BUS_CREDS_UID|SD_BUS_CREDS_GID|SD_BUS_CREDS_PID,
+                                                     true, &destination_creds);
+                        if (r < 0)
+                                return handle_policy_error(m, r);
+
+                        r = sd_bus_creds_get_unique_name(destination_creds, &destination_unique);
+                        if (r < 0)
+                                return handle_policy_error(m, r);
+
+                        sd_bus_creds_get_well_known_names(destination_creds, &destination_names);
+
+                        (void) sd_bus_creds_get_uid(destination_creds, &destination_uid);
+                        (void) sd_bus_creds_get_gid(destination_creds, &destination_gid);
+                }
+
+                /* First check if we (the sender) can send to this name */
+                if (strv_isempty(destination_names)) {
+                        if (policy_check_send(policy, our_ucred->uid, our_ucred->gid, m->header->type, NULL, m->path, m->interface, m->member))
+                                granted = true;
+                } else {
+                        char **n;
+
+                        STRV_FOREACH(n, destination_names) {
+                                if (policy_check_send(policy, our_ucred->uid, our_ucred->gid, m->header->type, *n, m->path, m->interface, m->member)) {
+
+                                        /* If we made a receiver decision,
+                                           then remember which name's policy
+                                           we used, and to which unique ID it
+                                           mapped when we made the
+                                           decision. Then, let's pass this to
+                                           the kernel when sending the
+                                           message, so that it refuses the
+                                           operation should the name and
+                                           unique ID not map to each other
+                                           anymore. */
+
+                                        r = free_and_strdup(&m->destination_ptr, *n);
+                                        if (r < 0)
+                                                return r;
+
+                                        r = bus_kernel_parse_unique_name(destination_unique, &m->verify_destination_id);
+                                        if (r < 0)
+                                                break;
+
+                                        granted = true;
+                                        break;
+                                }
+                        }
+                }
+
+                /* Then check if the recipient can receive from our name */
+                if (granted) {
+                        if (set_isempty(owned_names)) {
+                                if (policy_check_recv(policy, destination_uid, destination_gid, m->header->type, NULL, m->path, m->interface, m->member))
+                                        return 0;
+                        } else {
+                                Iterator i;
+                                char *n;
+
+                                SET_FOREACH(n, owned_names, i)
+                                        if (policy_check_recv(policy, destination_uid, destination_gid, m->header->type, n, m->path, m->interface, m->member))
+                                                return 0;
+                        }
+                }
+
+                /* Return an error back to the caller */
+                if (m->header->type == SD_BUS_MESSAGE_METHOD_CALL)
+                        return synthetic_reply_method_errorf(m, SD_BUS_ERROR_ACCESS_DENIED, "Access prohibited by XML sender policy.");
+
+                /* Return 1, indicating that the message shall not be processed any further */
+                return 1;
+        }
+
+        return 0;
+}
+
 static int process_hello(sd_bus *a, sd_bus *b, sd_bus_message *m, bool *got_hello) {
         _cleanup_bus_message_unref_ sd_bus_message *n = NULL;
         bool is_hello;
@@ -293,83 +1173,112 @@ static int process_hello(sd_bus *a, sd_bus *b, sd_bus_message *m, bool *got_hell
                 return 0;
 
         r = sd_bus_message_new_method_return(m, &n);
-        if (r < 0) {
-                log_error("Failed to generate HELLO reply: %s", strerror(-r));
-                return r;
-        }
+        if (r < 0)
+                return log_error_errno(r, "Failed to generate HELLO reply: %m");
 
         r = sd_bus_message_append(n, "s", a->unique_name);
-        if (r < 0) {
-                log_error("Failed to append unique name to HELLO reply: %s", strerror(-r));
-                return r;
-        }
+        if (r < 0)
+                return log_error_errno(r, "Failed to append unique name to HELLO reply: %m");
 
         r = bus_message_append_sender(n, "org.freedesktop.DBus");
-        if (r < 0) {
-                log_error("Failed to append sender to HELLO reply: %s", strerror(-r));
-                return r;
-        }
+        if (r < 0)
+                return log_error_errno(r, "Failed to append sender to HELLO reply: %m");
 
         r = bus_seal_synthetic_message(b, n);
-        if (r < 0) {
-                log_error("Failed to seal HELLO reply: %s", strerror(-r));
-                return r;
-        }
+        if (r < 0)
+                return log_error_errno(r, "Failed to seal HELLO reply: %m");
 
         r = sd_bus_send(b, n, NULL);
-        if (r < 0) {
-                log_error("Failed to send HELLO reply: %s", strerror(-r));
-                return r;
-        }
+        if (r < 0)
+                return log_error_errno(r, "Failed to send HELLO reply: %m");
 
         n = sd_bus_message_unref(n);
         r = sd_bus_message_new_signal(
                         b,
+                        &n,
                         "/org/freedesktop/DBus",
                         "org.freedesktop.DBus",
-                        "NameAcquired",
-                        &n);
-        if (r < 0) {
-                log_error("Failed to allocate initial NameAcquired message: %s", strerror(-r));
-                return r;
-        }
+                        "NameAcquired");
+        if (r < 0)
+                return log_error_errno(r, "Failed to allocate initial NameAcquired message: %m");
 
         r = sd_bus_message_append(n, "s", a->unique_name);
-        if (r < 0) {
-                log_error("Failed to append unique name to NameAcquired message: %s", strerror(-r));
-                return r;
-        }
+        if (r < 0)
+                return log_error_errno(r, "Failed to append unique name to NameAcquired message: %m");
 
         r = bus_message_append_sender(n, "org.freedesktop.DBus");
-        if (r < 0) {
-                log_error("Failed to append sender to NameAcquired message: %s", strerror(-r));
-                return r;
-        }
+        if (r < 0)
+                return log_error_errno(r, "Failed to append sender to NameAcquired message: %m");
 
         r = bus_seal_synthetic_message(b, n);
-        if (r < 0) {
-                log_error("Failed to seal NameAcquired message: %s", strerror(-r));
-                return r;
-        }
+        if (r < 0)
+                return log_error_errno(r, "Failed to seal NameAcquired message: %m");
 
         r = sd_bus_send(b, n, NULL);
-        if (r < 0) {
-                log_error("Failed to send NameAcquired message: %s", strerror(-r));
-                return r;
-        }
+        if (r < 0)
+                return log_error_errno(r, "Failed to send NameAcquired message: %m");
 
         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;
+}
+
+static int mac_smack_apply_label_and_drop_cap_mac_admin(pid_t its_pid, const char *new_label) {
+#ifdef HAVE_SMACK
+        int r = 0, k;
+
+        if (!mac_smack_use())
+                return 0;
+
+        if (new_label && its_pid > 0)
+                r = mac_smack_apply_pid(its_pid, new_label);
+
+        k = drop_capability(CAP_MAC_ADMIN);
+        return r < 0 ? r : k;
+#else
+        return 0;
+#endif
+}
+
 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_buffer = {}, *policy = NULL;
+        _cleanup_set_free_free_ Set *owned_names = NULL;
 
         log_set_target(LOG_TARGET_JOURNAL_OR_KMSG);
         log_parse_environment();
@@ -396,32 +1305,78 @@ 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);
+
+                r = mac_smack_apply_label_and_drop_cap_mac_admin(getpid(), peersec);
+                if (r < 0)
+                        log_warning_errno(r, "Failed to set SMACK label (%s) and drop CAP_MAC_ADMIN: %m", 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_errno(r, "Cannot resolve user name %s: %m", user);
+                        goto finish;
+                }
+
+                r = drop_privileges(uid, gid, 1ULL << CAP_IPC_OWNER);
+                if (r < 0)
+                        goto finish;
+        }
+
+        owned_names = set_new(&string_hash_ops);
+        if (!owned_names) {
+                log_oom();
+                goto finish;
         }
 
         r = sd_bus_new(&a);
         if (r < 0) {
-                log_error("Failed to allocate bus: %s", strerror(-r));
+                log_error_errno(r, "Failed to allocate bus: %m");
+                goto finish;
+        }
+
+        r = sd_bus_set_description(a, "sd-proxy");
+        if (r < 0) {
+                log_error_errno(r, "Failed to set bus name: %m");
                 goto finish;
         }
 
         r = sd_bus_set_address(a, arg_address);
         if (r < 0) {
-                log_error("Failed to set address to connect to: %s", strerror(-r));
+                log_error_errno(r, "Failed to set address to connect to: %m");
                 goto finish;
         }
 
         r = sd_bus_negotiate_fds(a, is_unix);
         if (r < 0) {
-                log_error("Failed to set FD negotiation: %s", strerror(-r));
+                log_error_errno(r, "Failed to set FD negotiation: %m");
+                goto finish;
+        }
+
+        r = sd_bus_negotiate_creds(a, true, SD_BUS_CREDS_UID|SD_BUS_CREDS_PID|SD_BUS_CREDS_GID|SD_BUS_CREDS_SELINUX_CONTEXT);
+        if (r < 0) {
+                log_error_errno(r, "Failed to set credential negotiation: %m");
                 goto finish;
         }
 
         if (ucred.pid > 0) {
-                a->fake_creds.pid = ucred.pid;
+                a->fake_pids.pid = ucred.pid;
+                a->fake_pids_valid = true;
+
                 a->fake_creds.uid = ucred.uid;
+                a->fake_creds.euid = UID_INVALID;
+                a->fake_creds.suid = UID_INVALID;
+                a->fake_creds.fsuid = UID_INVALID;
                 a->fake_creds.gid = ucred.gid;
+                a->fake_creds.egid = GID_INVALID;
+                a->fake_creds.sgid = GID_INVALID;
+                a->fake_creds.fsgid = GID_INVALID;
                 a->fake_creds_valid = true;
         }
 
@@ -430,57 +1385,115 @@ int main(int argc, char *argv[]) {
                 peersec = NULL;
         }
 
+        a->manual_peer_interface = true;
+
         r = sd_bus_start(a);
         if (r < 0) {
-                log_error("Failed to start bus client: %s", strerror(-r));
+                log_error_errno(r, "Failed to start bus client: %m");
                 goto finish;
         }
 
-        r = sd_bus_get_server_id(a, &server_id);
+        r = sd_bus_get_bus_id(a, &server_id);
         if (r < 0) {
-                log_error("Failed to get server ID: %s", strerror(-r));
+                log_error_errno(r, "Failed to get server ID: %m");
                 goto finish;
         }
 
+        if (a->is_kernel) {
+                if (!arg_configuration) {
+                        const char *scope;
+
+                        r = sd_bus_get_scope(a, &scope);
+                        if (r < 0) {
+                                log_error_errno(r, "Couldn't determine bus scope: %m");
+                                goto finish;
+                        }
+
+                        if (streq(scope, "system"))
+                                arg_configuration = strv_new(
+                                                "/etc/dbus-1/system.conf",
+                                                "/etc/dbus-1/system.d/",
+                                                "/etc/dbus-1/system-local.conf",
+                                                NULL);
+                        else if (streq(scope, "user"))
+                                arg_configuration = strv_new(
+                                                "/etc/dbus-1/session.conf",
+                                                "/etc/dbus-1/session.d/",
+                                                "/etc/dbus-1/session-local.conf",
+                                                NULL);
+                        else {
+                                log_error("Unknown scope %s, don't know which policy to load. Refusing.", scope);
+                                goto finish;
+                        }
+
+                        if (!arg_configuration) {
+                                r = log_oom();
+                                goto finish;
+                        }
+                }
+
+                r = policy_load(&policy_buffer, arg_configuration);
+                if (r < 0) {
+                        log_error_errno(r, "Failed to load policy: %m");
+                        goto finish;
+                }
+
+                policy = &policy_buffer;
+                /* policy_dump(policy); */
+
+                if (!policy_check_hello(policy, ucred.uid, ucred.gid)) {
+                        r = log_error_errno(EPERM, "Policy denied connection.");
+                        goto finish;
+                }
+        }
+
         r = sd_bus_new(&b);
         if (r < 0) {
-                log_error("Failed to allocate bus: %s", strerror(-r));
+                log_error_errno(r, "Failed to allocate bus: %m");
                 goto finish;
         }
 
         r = sd_bus_set_fd(b, in_fd, out_fd);
         if (r < 0) {
-                log_error("Failed to set fds: %s", strerror(-r));
+                log_error_errno(r, "Failed to set fds: %m");
                 goto finish;
         }
 
         r = sd_bus_set_server(b, 1, server_id);
         if (r < 0) {
-                log_error("Failed to set server mode: %s", strerror(-r));
+                log_error_errno(r, "Failed to set server mode: %m");
                 goto finish;
         }
 
         r = sd_bus_negotiate_fds(b, is_unix);
         if (r < 0) {
-                log_error("Failed to set FD negotiation: %s", strerror(-r));
+                log_error_errno(r, "Failed to set FD negotiation: %m");
+                goto finish;
+        }
+
+        r = sd_bus_negotiate_creds(b, true, SD_BUS_CREDS_UID|SD_BUS_CREDS_PID|SD_BUS_CREDS_GID|SD_BUS_CREDS_SELINUX_CONTEXT);
+        if (r < 0) {
+                log_error_errno(r, "Failed to set credential negotiation: %m");
                 goto finish;
         }
 
         r = sd_bus_set_anonymous(b, true);
         if (r < 0) {
-                log_error("Failed to set anonymous authentication: %s", strerror(-r));
+                log_error_errno(r, "Failed to set anonymous authentication: %m");
                 goto finish;
         }
 
+        b->manual_peer_interface = true;
+
         r = sd_bus_start(b);
         if (r < 0) {
-                log_error("Failed to start bus client: %s", strerror(-r));
+                log_error_errno(r, "Failed to start bus client: %m");
                 goto finish;
         }
 
-        r = rename_service(b);
+        r = rename_service(a, b);
         if (r < 0)
-                log_debug("Failed to rename process: %s", strerror(-r));
+                log_debug_errno(r, "Failed to rename process: %m");
 
         if (a->is_kernel) {
                 _cleanup_free_ char *match = NULL;
@@ -488,7 +1501,7 @@ int main(int argc, char *argv[]) {
 
                 r = sd_bus_get_unique_name(a, &unique);
                 if (r < 0) {
-                        log_error("Failed to get unique name: %s", strerror(-r));
+                        log_error_errno(r, "Failed to get unique name: %m");
                         goto finish;
                 }
 
@@ -506,9 +1519,9 @@ 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));
+                        log_error_errno(r, "Failed to add match for NameLost: %m");
                         goto finish;
                 }
 
@@ -527,9 +1540,9 @@ 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));
+                        log_error_errno(r, "Failed to add match for NameAcquired: %m");
                         goto finish;
                 }
         }
@@ -543,18 +1556,22 @@ int main(int argc, char *argv[]) {
                 int k;
 
                 if (got_hello) {
+                        /* Read messages from bus, to pass them on to our client */
+
                         r = sd_bus_process(a, &m);
                         if (r < 0) {
                                 /* treat 'connection reset by peer' as clean exit condition */
                                 if (r == -ECONNRESET)
                                         r = 0;
                                 else
-                                        log_error("Failed to process bus a: %s", strerror(-r));
+                                        log_error_errno(r, "Failed to process bus a: %m");
 
                                 goto finish;
                         }
 
                         if (m) {
+                                bool processed = false;
+
                                 /* We officially got EOF, let's quit */
                                 if (sd_bus_message_is_signal(m, "org.freedesktop.DBus.Local", "Disconnected")) {
                                         r = 0;
@@ -564,15 +1581,37 @@ int main(int argc, char *argv[]) {
                                 k = synthesize_name_acquired(a, b, m);
                                 if (k < 0) {
                                         r = k;
-                                        log_error("Failed to synthesize message: %s", strerror(-r));
+                                        log_error_errno(r, "Failed to synthesize message: %m");
                                         goto finish;
                                 }
 
-                                k = sd_bus_send(b, m, NULL);
-                                if (k < 0) {
-                                        r = k;
-                                        log_error("Failed to send message: %s", strerror(-r));
-                                        goto finish;
+                                patch_sender(a, m);
+
+                                if (policy) {
+                                        k = process_policy(a, b, m, policy, &ucred, owned_names);
+                                        if (k < 0) {
+                                                r = k;
+                                                log_error_errno(r, "Failed to process policy: %m");
+                                                goto finish;
+                                        } else if (k > 0) {
+                                                r = 1;
+                                                processed = true;
+                                        }
+                                }
+
+                                if (!processed) {
+                                        k = sd_bus_send(b, m, NULL);
+                                        if (k < 0) {
+                                                if (k == -ECONNRESET)
+                                                        r = 0;
+                                                else {
+                                                        r = k;
+                                                        log_error_errno(r, "Failed to send message to client: %m");
+                                                }
+
+                                                goto finish;
+                                        } else
+                                                r = 1;
                                 }
                         }
 
@@ -580,18 +1619,21 @@ int main(int argc, char *argv[]) {
                                 continue;
                 }
 
+                /* Read messages from our client, to pass them on to the bus */
                 r = sd_bus_process(b, &m);
                 if (r < 0) {
                         /* treat 'connection reset by peer' as clean exit condition */
                         if (r == -ECONNRESET)
                                 r = 0;
                         else
-                                log_error("Failed to process bus b: %s", strerror(-r));
+                                log_error_errno(r, "Failed to process bus b: %m");
 
                         goto finish;
                 }
 
                 if (m) {
+                        bool processed = false;
+
                         /* We officially got EOF, let's quit */
                         if (sd_bus_message_is_signal(m, "org.freedesktop.DBus.Local", "Disconnected")) {
                                 r = 0;
@@ -601,17 +1643,58 @@ int main(int argc, char *argv[]) {
                         k = process_hello(a, b, m, &got_hello);
                         if (k < 0) {
                                 r = k;
+                                log_error_errno(r, "Failed to process HELLO: %m");
                                 goto finish;
+                        } else if (k > 0) {
+                                processed = true;
+                                r = 1;
                         }
 
-                        if (k > 0)
-                                r = k;
-                        else {
-                                k = sd_bus_send(a, m, NULL);
+                        if (!processed) {
+                                k = process_driver(a, b, m, policy, &ucred, owned_names);
                                 if (k < 0) {
                                         r = k;
-                                        log_error("Failed to send message: %s", strerror(-r));
+                                        log_error_errno(r, "Failed to process driver calls: %m");
                                         goto finish;
+                                } else if (k > 0) {
+                                        processed = true;
+                                        r = 1;
+                                }
+
+                                if (!processed) {
+
+                                        for (;;) {
+                                                if (policy) {
+                                                        k = process_policy(b, a, m, policy, &ucred, owned_names);
+                                                        if (k < 0) {
+                                                                r = k;
+                                                                log_error_errno(r, "Failed to process policy: %m");
+                                                                goto finish;
+                                                        } else if (k > 0) {
+                                                                processed = true;
+                                                                r = 1;
+                                                                break;
+                                                        }
+                                                }
+
+                                                k = sd_bus_send(a, m, NULL);
+                                                if (k < 0) {
+                                                        if (k == -EREMCHG)
+                                                                /* The name database changed since the policy check, hence let's check again */
+                                                                continue;
+                                                        else if (k == -ECONNRESET)
+                                                                r = 0;
+                                                        else {
+                                                                r = k;
+                                                                log_error_errno(r, "Failed to send message to bus: %m");
+                                                        }
+
+                                                        goto finish;
+                                                } else
+                                                        r = 1;
+
+                                                break;
+                                        }
                                 }
                         }
                 }
@@ -621,31 +1704,31 @@ int main(int argc, char *argv[]) {
 
                 fd = sd_bus_get_fd(a);
                 if (fd < 0) {
-                        log_error("Failed to get fd: %s", strerror(-r));
+                        log_error_errno(r, "Failed to get fd: %m");
                         goto finish;
                 }
 
                 events_a = sd_bus_get_events(a);
                 if (events_a < 0) {
-                        log_error("Failed to get events mask: %s", strerror(-r));
+                        log_error_errno(r, "Failed to get events mask: %m");
                         goto finish;
                 }
 
                 r = sd_bus_get_timeout(a, &timeout_a);
                 if (r < 0) {
-                        log_error("Failed to get timeout: %s", strerror(-r));
+                        log_error_errno(r, "Failed to get timeout: %m");
                         goto finish;
                 }
 
                 events_b = sd_bus_get_events(b);
                 if (events_b < 0) {
-                        log_error("Failed to get events mask: %s", strerror(-r));
+                        log_error_errno(r, "Failed to get events mask: %m");
                         goto finish;
                 }
 
                 r = sd_bus_get_timeout(b, &timeout_b);
                 if (r < 0) {
-                        log_error("Failed to get timeout: %s", strerror(-r));
+                        log_error_errno(r, "Failed to get timeout: %m");
                         goto finish;
                 }
 
@@ -675,16 +1758,19 @@ int main(int argc, char *argv[]) {
 
                 r = ppoll(pollfd, 3, ts, NULL);
                 if (r < 0) {
-                        log_error("ppoll() failed: %m");
+                        log_error_errno(errno, "ppoll() failed: %m");
                         goto finish;
                 }
         }
 
-        r = 0;
-
 finish:
-        sd_bus_flush(a);
-        sd_bus_flush(b);
+        sd_notify(false,
+                  "STOPPING=1\n"
+                  "STATUS=Shutting down.");
+
+        policy_free(&policy_buffer);
+        strv_free(arg_configuration);
+        free(arg_address);
 
         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 }