hostnamed: introduce systemd-hostnamed

http://www.freedesktop.org/wiki/Software/systemd/hostnamed

1 files changed, 689 insertions, 0 deletions

diff --git a/src/hostnamed.c b/src/hostnamed.c
new file mode 100644
index 0000000000..4ba1d4a570
--- /dev/null
+++ b/src/hostnamed.c
@@ -0,0 +1,689 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2010 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <dbus/dbus.h>
+
+#include <errno.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "util.h"
+#include "strv.h"
+#include "dbus-common.h"
+
+#define INTROSPECTION                                                   \
+        DBUS_INTROSPECT_1_0_XML_DOCTYPE_DECL_NODE                       \
+        "<node>\n"                                                      \
+        " <interface name=\"org.freedesktop.hostname1\">\n"             \
+        "  <property name=\"Hostname\" type=\"s\" access=\"read\"/>\n"  \
+        "  <property name=\"StaticHostname\" type=\"s\" access=\"read\"/>\n" \
+        "  <property name=\"PrettyHostname\" type=\"s\" access=\"read\"/>\n" \
+        "  <property name=\"IconName\" type=\"s\" access=\"read\"/>\n"  \
+        "  <method name=\"SetHostname\">\n"                             \
+        "   <arg name=\"name\" type=\"s\" direction=\"in\"/>\n"         \
+        "   <arg name=\"user_interaction\" type=\"b\" direction=\"in\"/>\n" \
+        "  </method>\n"                                                 \
+        "  <method name=\"SetStaticHostname\">\n"                       \
+        "   <arg name=\"name\" type=\"s\" direction=\"in\"/>\n"         \
+        "   <arg name=\"user_interaction\" type=\"b\" direction=\"in\"/>\n" \
+        "  </method>\n"                                                 \
+        "  <method name=\"SetPrettyHostname\">\n"                       \
+        "   <arg name=\"name\" type=\"s\" direction=\"in\"/>\n"         \
+        "   <arg name=\"user_interaction\" type=\"b\" direction=\"in\"/>\n" \
+        "  </method>\n"                                                 \
+        "  <method name=\"SetIconName\">\n"                             \
+        "   <arg name=\"name\" type=\"s\" direction=\"in\"/>\n"         \
+        "   <arg name=\"user_interaction\" type=\"b\" direction=\"in\"/>\n" \
+        "  </method>\n"                                                 \
+        " </interface>\n"                                               \
+        BUS_PROPERTIES_INTERFACE                                        \
+        BUS_INTROSPECTABLE_INTERFACE                                    \
+        BUS_PEER_INTERFACE                                              \
+        "</node>\n"
+
+#define INTERFACES_LIST                         \
+        BUS_GENERIC_INTERFACES_LIST             \
+        "org.freedesktop.hostname1\0"
+
+enum {
+        PROP_HOSTNAME,
+        PROP_STATIC_HOSTNAME,
+        PROP_PRETTY_HOSTNAME,
+        PROP_ICON_NAME,
+        _PROP_MAX
+};
+
+static char *data[_PROP_MAX] = {
+        NULL,
+        NULL,
+        NULL,
+        NULL
+};
+
+static void free_data(void) {
+        int p;
+
+        for (p = 0; p < _PROP_MAX; p++) {
+                free(data[p]);
+                data[p] = NULL;
+        }
+}
+
+static int read_data(void) {
+        int r;
+
+        free_data();
+
+        data[PROP_HOSTNAME] = gethostname_malloc();
+        if (!data[PROP_HOSTNAME])
+                return -ENOMEM;
+
+        r = read_one_line_file("/etc/hostname", &data[PROP_STATIC_HOSTNAME]);
+        if (r < 0 && r != -ENOENT)
+                return r;
+
+        r = parse_env_file("/etc/machine-info", NEWLINE,
+                           "PRETTY_HOSTNAME", &data[PROP_PRETTY_HOSTNAME],
+                           "ICON_NAME", &data[PROP_ICON_NAME],
+                           NULL);
+        if (r < 0 && r != -ENOENT)
+                return r;
+
+        return 0;
+}
+
+static const char* fallback_icon_name(void) {
+
+#if defined(__i386__) || defined(__x86_64__)
+        int r;
+        char *type;
+        unsigned t;
+#endif
+
+        if (detect_virtualization(NULL) > 0)
+                return "computer-vm";
+
+#if defined(__i386__) || defined(__x86_64__)
+        r = read_one_line_file("/sys/class/dmi/id/chassis_type", &type);
+        if (r < 0)
+                return NULL;
+
+        r = safe_atou(type, &t);
+        free(type);
+
+        if (r < 0)
+                return NULL;
+
+        /* We only list the really obvious cases here. The DMI data is
+           unreliable enough, so let's not do any additional guesswork
+           on top of that. */
+
+        switch (t) {
+
+        case 0x3:
+        case 0x4:
+        case 0x6:
+        case 0x7:
+                return "computer-desktop";
+
+        case 0x9:
+        case 0xA:
+        case 0xE:
+                return "computer-laptop";
+
+        case 0x11:
+                return "computer-server";
+        }
+
+#endif
+        return NULL;
+}
+
+static int write_data_hostname(void) {
+        const char *hn;
+
+        if (isempty(data[PROP_HOSTNAME]))
+                hn = "localhost";
+        else
+                hn = data[PROP_HOSTNAME];
+
+        if (sethostname(hn, strlen(hn)) < 0)
+                return -errno;
+
+        return 0;
+}
+
+static int write_data_static_hostname(void) {
+
+        if (isempty(data[PROP_STATIC_HOSTNAME])) {
+
+                if (unlink("/etc/hostname") < 0)
+                        return errno == ENOENT ? 0 : -errno;
+
+                return 0;
+        }
+
+        return write_one_line_file("/etc/hostname", data[PROP_STATIC_HOSTNAME]);
+}
+
+static int write_data_other(void) {
+        static const char * const name[_PROP_MAX] = {
+                [PROP_PRETTY_HOSTNAME] = "PRETTY_HOSTNAME",
+                [PROP_ICON_NAME] = "ICON_NAME"
+        };
+
+        char **l = NULL;
+        int r, p;
+
+        r = load_env_file("/etc/machine-info", &l);
+        if (r < 0 && r != -ENOENT)
+                return r;
+
+        for (p = 2; p < _PROP_MAX; p++) {
+                char *t, **u;
+
+                assert(name[p]);
+
+                if (isempty(data[p]))  {
+                        l = strv_env_unset(l, name[p]);
+                        continue;
+                }
+
+                if (asprintf(&t, "%s=%s", name[p], strempty(data[p])) < 0) {
+                        strv_free(l);
+                        return -ENOMEM;
+                }
+
+                u = strv_env_set(l, t);
+                free(t);
+                strv_free(l);
+
+                if (!u)
+                        return -ENOMEM;
+                l = u;
+        }
+
+        if (strv_isempty(l)) {
+
+                if (unlink("/etc/machine-info") < 0)
+                        return errno == ENOENT ? 0 : -errno;
+
+                return 0;
+        }
+
+        r = write_env_file("/etc/machine-info", l);
+        strv_free(l);
+
+        return r;
+}
+
+/* This mimics dbus_bus_get_unix_user() */
+static pid_t get_unix_process_id(
+                DBusConnection *connection,
+                const char *name,
+                DBusError *error) {
+
+        DBusMessage *m = NULL, *reply = NULL;
+        uint32_t pid = 0;
+
+        m = dbus_message_new_method_call(
+                        DBUS_SERVICE_DBUS,
+                        DBUS_PATH_DBUS,
+                        DBUS_INTERFACE_DBUS,
+                        "GetConnectionUnixProcessID");
+        if (!m) {
+                dbus_set_error_const(error, DBUS_ERROR_NO_MEMORY, NULL);
+                goto finish;
+        }
+
+        if (!dbus_message_append_args(
+                            m,
+                            DBUS_TYPE_STRING, &name,
+                            DBUS_TYPE_INVALID)) {
+                dbus_set_error_const(error, DBUS_ERROR_NO_MEMORY, NULL);
+                goto finish;
+        }
+
+        reply = dbus_connection_send_with_reply_and_block(connection, m, -1, error);
+        if (!reply)
+                goto finish;
+
+        if (dbus_set_error_from_message(error, reply))
+                goto finish;
+
+        if (!dbus_message_get_args(
+                            reply, error,
+                            DBUS_TYPE_UINT32, &pid,
+                            DBUS_TYPE_INVALID))
+                goto finish;
+
+finish:
+        if (m)
+                dbus_message_unref(m);
+
+        if (reply)
+                dbus_message_unref(reply);
+
+        return (pid_t) pid;
+}
+
+static int verify_polkit(
+                DBusConnection *c,
+                DBusMessage *request,
+                const char *action,
+                bool interactive,
+                DBusError *error) {
+
+        DBusMessage *m = NULL, *reply = NULL;
+        const char *unix_process = "unix-process", *pid = "pid", *starttime = "start-time", *cancel_id = "";
+        const char *sender;
+        uint32_t flags = interactive ? 1 : 0;
+        pid_t pid_raw;
+        uint32_t pid_u32;
+        unsigned long long starttime_raw;
+        uint64_t starttime_u64;
+        DBusMessageIter iter_msg, iter_struct, iter_array, iter_dict, iter_variant;
+        int r;
+        dbus_bool_t authorized = FALSE;
+
+        assert(c);
+        assert(request);
+
+        sender = dbus_message_get_sender(request);
+        if (!sender)
+                return -EINVAL;
+
+        pid_raw = get_unix_process_id(c, sender, error);
+        if (pid_raw == 0)
+                return -EINVAL;
+
+        r = get_starttime_of_pid(pid_raw, &starttime_raw);
+        if (r < 0)
+                return r;
+
+        m = dbus_message_new_method_call(
+                        "org.freedesktop.PolicyKit1",
+                        "/org/freedesktop/PolicyKit1/Authority",
+                        "org.freedesktop.PolicyKit1.Authority",
+                        "CheckAuthorization");
+        if (!m)
+                return -ENOMEM;
+
+        dbus_message_iter_init_append(m, &iter_msg);
+
+        pid_u32 = (uint32_t) pid_raw;
+        starttime_u64 = (uint64_t) starttime_raw;
+
+        if (!dbus_message_iter_open_container(&iter_msg, DBUS_TYPE_STRUCT, NULL, &iter_struct) ||
+            !dbus_message_iter_append_basic(&iter_struct, DBUS_TYPE_STRING, &unix_process) ||
+            !dbus_message_iter_open_container(&iter_struct, DBUS_TYPE_ARRAY, "{sv}", &iter_array) ||
+            !dbus_message_iter_open_container(&iter_array, DBUS_TYPE_DICT_ENTRY, NULL, &iter_dict) ||
+            !dbus_message_iter_append_basic(&iter_dict, DBUS_TYPE_STRING, &pid) ||
+            !dbus_message_iter_open_container(&iter_dict, DBUS_TYPE_VARIANT, "u", &iter_variant) ||
+            !dbus_message_iter_append_basic(&iter_variant, DBUS_TYPE_UINT32, &pid_u32) ||
+            !dbus_message_iter_close_container(&iter_dict, &iter_variant) ||
+            !dbus_message_iter_close_container(&iter_array, &iter_dict) ||
+            !dbus_message_iter_open_container(&iter_array, DBUS_TYPE_DICT_ENTRY, NULL, &iter_dict) ||
+            !dbus_message_iter_append_basic(&iter_dict, DBUS_TYPE_STRING, &starttime) ||
+            !dbus_message_iter_open_container(&iter_dict, DBUS_TYPE_VARIANT, "t", &iter_variant) ||
+            !dbus_message_iter_append_basic(&iter_variant, DBUS_TYPE_UINT64, &starttime_u64) ||
+            !dbus_message_iter_close_container(&iter_dict, &iter_variant) ||
+            !dbus_message_iter_close_container(&iter_array, &iter_dict) ||
+            !dbus_message_iter_close_container(&iter_struct, &iter_array) ||
+            !dbus_message_iter_close_container(&iter_msg, &iter_struct) ||
+            !dbus_message_iter_append_basic(&iter_msg, DBUS_TYPE_STRING, &action) ||
+            !dbus_message_iter_open_container(&iter_msg, DBUS_TYPE_ARRAY, "{ss}", &iter_array) ||
+            !dbus_message_iter_close_container(&iter_msg, &iter_array) ||
+            !dbus_message_iter_append_basic(&iter_msg, DBUS_TYPE_UINT32, &flags) ||
+            !dbus_message_iter_append_basic(&iter_msg, DBUS_TYPE_STRING, &cancel_id)) {
+                r = -ENOMEM;
+                goto finish;
+        }
+
+        reply = dbus_connection_send_with_reply_and_block(c, m, -1, error);
+        if (!reply) {
+                r = -EIO;
+                goto finish;
+        }
+
+        if (dbus_set_error_from_message(error, reply)) {
+                r = -EIO;
+                goto finish;
+        }
+
+        if (!dbus_message_iter_init(reply, &iter_msg) ||
+            dbus_message_iter_get_arg_type(&iter_msg) != DBUS_TYPE_STRUCT) {
+                r = -EIO;
+                goto finish;
+        }
+
+        dbus_message_iter_recurse(&iter_msg, &iter_struct);
+
+        if (dbus_message_iter_get_arg_type(&iter_struct) != DBUS_TYPE_BOOLEAN) {
+                r = -EIO;
+                goto finish;
+        }
+
+        dbus_message_iter_get_basic(&iter_struct, &authorized);
+
+        r = authorized ? 0 : -EPERM;
+
+finish:
+
+        if (m)
+                dbus_message_unref(m);
+
+        if (reply)
+                dbus_message_unref(reply);
+
+        return r;
+}
+
+static int bus_hostname_append_icon_name(DBusMessageIter *i, const char *property, void *userdata) {
+        const char *name;
+
+        assert(i);
+        assert(property);
+
+        if (isempty(data[PROP_ICON_NAME]))
+                name = fallback_icon_name();
+        else
+                name = data[PROP_ICON_NAME];
+
+        return bus_property_append_string(i, property, (void*) name);
+}
+
+static DBusHandlerResult hostname_message_handler(
+                DBusConnection *connection,
+                DBusMessage *message,
+                void *userdata) {
+
+        const BusProperty properties[] = {
+                { "org.freedesktop.hostname1", "Hostname",       bus_property_append_string,    "s", data[PROP_HOSTNAME]},
+                { "org.freedesktop.hostname1", "StaticHostname", bus_property_append_string,    "s", data[PROP_STATIC_HOSTNAME]},
+                { "org.freedesktop.hostname1", "PrettyHostname", bus_property_append_string,    "s", data[PROP_PRETTY_HOSTNAME]},
+                { "org.freedesktop.hostname1", "IconName",       bus_hostname_append_icon_name, "s", data[PROP_ICON_NAME]},
+                { NULL, NULL, NULL, NULL, NULL }
+        };
+
+        DBusMessage *reply = NULL, *changed = NULL;
+        DBusError error;
+        int r;
+
+        assert(connection);
+        assert(message);
+
+        dbus_error_init(&error);
+
+        if (dbus_message_is_method_call(message, "org.freedesktop.hostname1", "SetHostname")) {
+                const char *name;
+                dbus_bool_t interactive;
+
+                if (!dbus_message_get_args(
+                                    message,
+                                    &error,
+                                    DBUS_TYPE_STRING, &name,
+                                    DBUS_TYPE_BOOLEAN, &interactive,
+                                    DBUS_TYPE_INVALID))
+                        return bus_send_error_reply(connection, message, &error, -EINVAL);
+
+                if (isempty(name))
+                        name = data[PROP_STATIC_HOSTNAME];
+
+                if (isempty(name))
+                        name = "localhost";
+
+                if (!hostname_is_valid(name))
+                        return bus_send_error_reply(connection, message, NULL, -EINVAL);
+
+                if (!streq_ptr(name, data[PROP_HOSTNAME])) {
+                        char *h;
+
+                        r = verify_polkit(connection, message, "org.freedesktop.hostname1.set-hostname", interactive, &error);
+                        if (r < 0)
+                                return bus_send_error_reply(connection, message, &error, r);
+
+                        h = strdup(name);
+                        if (!h)
+                                goto oom;
+
+                        free(data[PROP_HOSTNAME]);
+                        data[PROP_HOSTNAME] = h;
+
+                        r = write_data_hostname();
+                        if (r < 0)
+                                return bus_send_error_reply(connection, message, NULL, r);
+
+                        log_info("Changed host name to '%s'", data[PROP_HOSTNAME]);
+
+                        changed = bus_properties_changed_new(
+                                        "/org/freedesktop/hostname1",
+                                        "org.freedesktop.hostname1",
+                                        "Hostname\0");
+                        if (!changed)
+                                goto oom;
+                }
+
+        } else if (dbus_message_is_method_call(message, "org.freedesktop.hostname1", "SetStaticHostname")) {
+                const char *name;
+                dbus_bool_t interactive;
+
+                if (!dbus_message_get_args(
+                                    message,
+                                    &error,
+                                    DBUS_TYPE_STRING, &name,
+                                    DBUS_TYPE_BOOLEAN, &interactive,
+                                    DBUS_TYPE_INVALID))
+                        return bus_send_error_reply(connection, message, &error, -EINVAL);
+
+                if (isempty(name))
+                        name = NULL;
+
+                if (!streq_ptr(name, data[PROP_STATIC_HOSTNAME])) {
+
+                        r = verify_polkit(connection, message, "org.freedesktop.hostname1.set-static-hostname", interactive, &error);
+                        if (r < 0)
+                                return bus_send_error_reply(connection, message, &error, r);
+
+                        if (isempty(name)) {
+                                free(data[PROP_STATIC_HOSTNAME]);
+                                data[PROP_STATIC_HOSTNAME] = NULL;
+                        } else {
+                                char *h;
+
+                                if (!hostname_is_valid(name))
+                                        return bus_send_error_reply(connection, message, NULL, -EINVAL);
+
+                                h = strdup(name);
+                                if (!h)
+                                        goto oom;
+
+                                free(data[PROP_STATIC_HOSTNAME]);
+                                data[PROP_STATIC_HOSTNAME] = h;
+                        }
+
+                        r = write_data_static_hostname();
+                        if (r < 0)
+                                return bus_send_error_reply(connection, message, NULL, r);
+
+                        log_info("Changed static host name to '%s'", data[PROP_HOSTNAME]);
+
+                        changed = bus_properties_changed_new(
+                                        "/org/freedesktop/hostname1",
+                                        "org.freedesktop.hostname1",
+                                        "StaticHostname\0");
+                        if (!changed)
+                                goto oom;
+                }
+
+        } else if (dbus_message_is_method_call(message, "org.freedesktop.hostname1", "SetPrettyHostname") ||
+                   dbus_message_is_method_call(message, "org.freedesktop.hostname1", "SetIconName")) {
+
+                const char *name;
+                dbus_bool_t interactive;
+                int k;
+
+                if (!dbus_message_get_args(
+                                    message,
+                                    &error,
+                                    DBUS_TYPE_STRING, &name,
+                                    DBUS_TYPE_BOOLEAN, &interactive,
+                                    DBUS_TYPE_INVALID))
+                        return bus_send_error_reply(connection, message, &error, -EINVAL);
+
+                if (isempty(name))
+                        name = NULL;
+
+                k = streq(dbus_message_get_member(message), "SetPrettyHostname") ? PROP_PRETTY_HOSTNAME : PROP_ICON_NAME;
+
+                if (!streq_ptr(name, data[k])) {
+
+                        r = verify_polkit(connection, message, "org.freedesktop.hostname1.set-machine-info", interactive, &error);
+                        if (r < 0)
+                                return bus_send_error_reply(connection, message, &error, r);
+
+                        if (isempty(name)) {
+                                free(data[k]);
+                                data[k] = NULL;
+                        } else {
+                                char *h;
+
+                                h = strdup(name);
+                                if (!h)
+                                        goto oom;
+
+                                free(data[k]);
+                                data[k] = h;
+                        }
+
+                        r = write_data_other();
+                        if (r < 0)
+                                return bus_send_error_reply(connection, message, NULL, r);
+
+                        log_info("Changed %s to '%s'", k == PROP_PRETTY_HOSTNAME ? "pretty host name" : "icon name", data[k]);
+
+                        changed = bus_properties_changed_new(
+                                        "/org/freedesktop/hostname1",
+                                        "org.freedesktop.hostname1",
+                                        k == PROP_PRETTY_HOSTNAME ? "PrettyHostname\0" : "IconName\0");
+                        if (!changed)
+                                goto oom;
+                }
+
+        } else
+                return bus_default_message_handler(connection, message, INTROSPECTION, INTERFACES_LIST, properties);
+
+        if (!(reply = dbus_message_new_method_return(message)))
+                goto oom;
+
+        if (!dbus_connection_send(connection, reply, NULL))
+                goto oom;
+
+        dbus_message_unref(reply);
+        reply = NULL;
+
+        if (changed) {
+
+                if (!dbus_connection_send(connection, changed, NULL))
+                        goto oom;
+
+                dbus_message_unref(changed);
+        }
+
+        return DBUS_HANDLER_RESULT_HANDLED;
+
+oom:
+        if (reply)
+                dbus_message_unref(reply);
+
+        if (changed)
+                dbus_message_unref(changed);
+
+        dbus_error_free(&error);
+
+        return DBUS_HANDLER_RESULT_NEED_MEMORY;
+}
+
+int main(int argc, char *argv[]) {
+        const DBusObjectPathVTable hostname_vtable = {
+                .message_function = hostname_message_handler
+        };
+
+        DBusConnection *bus = NULL;
+        DBusError error;
+        int r;
+
+        dbus_error_init(&error);
+
+        log_set_target(LOG_TARGET_AUTO);
+        log_parse_environment();
+        log_open();
+
+        if (argc != 1) {
+                log_error("This program takes no arguments.");
+                r = -EINVAL;
+                goto finish;
+        }
+
+        umask(0022);
+
+        r = read_data();
+        if (r < 0) {
+                log_error("Failed to read hostname data: %s", strerror(-r));
+                goto finish;
+        }
+
+        bus = dbus_bus_get_private(DBUS_BUS_SYSTEM, &error);
+        if (!bus) {
+                log_error("Failed to get system D-Bus connection: %s", error.message);
+                r = -ECONNREFUSED;
+                goto finish;
+        }
+
+        if (!dbus_connection_register_object_path(bus, "/org/freedesktop/hostname1", &hostname_vtable, NULL)) {
+                log_error("Not enough memory");
+                r = -ENOMEM;
+                goto finish;
+        }
+
+        if (dbus_bus_request_name(bus, "org.freedesktop.hostname1", DBUS_NAME_FLAG_DO_NOT_QUEUE, &error) < 0) {
+                log_error("Failed to register name on bus: %s", error.message);
+                goto finish;
+        }
+
+        while (dbus_connection_read_write_dispatch(bus, -1))
+                ;
+
+        r = 0;
+
+finish:
+        free_data();
+
+        if (bus) {
+                dbus_connection_flush(bus);
+                dbus_connection_close(bus);
+                dbus_connection_unref(bus);
+        }
+
+        dbus_error_free(&error);
+
+        return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
+}