// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2010 Dan Williams <dcbw@redhat.com>
* Copyright (C) 2016 Sjoerd Simons <sjoerd@luon.net>
*/
#include "nm-default.h"
#include "nm-dns-systemd-resolved.h"
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <arpa/inet.h>
#include <sys/stat.h>
#include <linux/if.h>
#include "nm-glib-aux/nm-c-list.h"
#include "nm-glib-aux/nm-dbus-aux.h"
#include "nm-core-internal.h"
#include "platform/nm-platform.h"
#include "nm-utils.h"
#include "nm-ip4-config.h"
#include "nm-ip6-config.h"
#include "nm-dbus-manager.h"
#include "nm-manager.h"
#include "nm-setting-connection.h"
#include "devices/nm-device.h"
#include "NetworkManagerUtils.h"
#include "nm-std-aux/nm-dbus-compat.h"
#define SYSTEMD_RESOLVED_DBUS_SERVICE "org.freedesktop.resolve1"
#define SYSTEMD_RESOLVED_MANAGER_IFACE "org.freedesktop.resolve1.Manager"
#define SYSTEMD_RESOLVED_DBUS_PATH "/org/freedesktop/resolve1"
/*****************************************************************************/
typedef struct {
int ifindex;
CList configs_lst_head;
} InterfaceConfig;
typedef struct {
CList request_queue_lst;
const char *operation;
GVariant *argument;
} RequestItem;
/*****************************************************************************/
typedef struct {
GDBusConnection *dbus_connection;
GCancellable *cancellable;
CList request_queue_lst_head;
guint name_owner_changed_id;
bool send_updates_warn_ratelimited:1;
bool try_start_blocked:1;
bool dbus_has_owner:1;
bool dbus_initied:1;
} NMDnsSystemdResolvedPrivate;
struct _NMDnsSystemdResolved {
NMDnsPlugin parent;
NMDnsSystemdResolvedPrivate _priv;
};
struct _NMDnsSystemdResolvedClass {
NMDnsPluginClass parent;
};
G_DEFINE_TYPE (NMDnsSystemdResolved, nm_dns_systemd_resolved, NM_TYPE_DNS_PLUGIN)
#define NM_DNS_SYSTEMD_RESOLVED_GET_PRIVATE(self) _NM_GET_PRIVATE (self, NMDnsSystemdResolved, NM_IS_DNS_SYSTEMD_RESOLVED)
/*****************************************************************************/
#define _NMLOG_DOMAIN LOGD_DNS
#define _NMLOG(level, ...) __NMLOG_DEFAULT_WITH_ADDR (level, _NMLOG_DOMAIN, "dns-sd-resolved", __VA_ARGS__)
/*****************************************************************************/
static void
_request_item_free (RequestItem *request_item)
{
c_list_unlink_stale (&request_item->request_queue_lst);
g_variant_unref (request_item->argument);
g_slice_free (RequestItem, request_item);
}
static void
_request_item_append (CList *request_queue_lst_head,
const char *operation,
GVariant *argument)
{
RequestItem *request_item;
request_item = g_slice_new (RequestItem);
request_item->operation = operation;
request_item->argument = g_variant_ref_sink (argument);
c_list_link_tail (request_queue_lst_head, &request_item->request_queue_lst);
}
/*****************************************************************************/
static void
_interface_config_free (InterfaceConfig *config)
{
nm_c_list_elem_free_all (&config->configs_lst_head, NULL);
g_slice_free (InterfaceConfig, config);
}
static void
call_done (GObject *source, GAsyncResult *r, gpointer user_data)
{
gs_unref_variant GVariant *v = NULL;
gs_free_error GError *error = NULL;
NMDnsSystemdResolved *self = (NMDnsSystemdResolved *) user_data;
NMDnsSystemdResolvedPrivate *priv;
v = g_dbus_connection_call_finish (G_DBUS_CONNECTION (source), r, &error);
if ( !v
&& g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
return;
priv = NM_DNS_SYSTEMD_RESOLVED_GET_PRIVATE (self);
if (!v) {
if (!priv->send_updates_warn_ratelimited) {
priv->send_updates_warn_ratelimited = TRUE;
_LOGW ("send-updates failed to update systemd-resolved: %s", error->message);
} else
_LOGD ("send-updates failed: %s", error->message);
} else
priv->send_updates_warn_ratelimited = FALSE;
}
static void
update_add_ip_config (NMDnsSystemdResolved *self,
GVariantBuilder *dns,
GVariantBuilder *domains,
NMDnsIPConfigData *data)
{
int addr_family;
gsize addr_size;
guint i, n;
gboolean is_routing;
const char **iter;
const char *domain;
addr_family = nm_ip_config_get_addr_family (data->ip_config);
addr_size = nm_utils_addr_family_to_size (addr_family);
if (!data->domains.search || !data->domains.search[0])
return;
n = nm_ip_config_get_num_nameservers (data->ip_config);
for (i = 0 ; i < n; i++) {
g_variant_builder_open (dns, G_VARIANT_TYPE ("(iay)"));
g_variant_builder_add (dns, "i", addr_family);
g_variant_builder_add_value (dns,
g_variant_new_fixed_array (G_VARIANT_TYPE_BYTE,
nm_ip_config_get_nameserver (data->ip_config, i),
addr_size,
1));
g_variant_builder_close (dns);
}
for (iter = data->domains.search; *iter; iter++) {
domain = nm_utils_parse_dns_domain (*iter, &is_routing);
g_variant_builder_add (domains, "(sb)", domain[0] ? domain : ".", is_routing);
}
}
static void
free_pending_updates (NMDnsSystemdResolved *self)
{
NMDnsSystemdResolvedPrivate *priv = NM_DNS_SYSTEMD_RESOLVED_GET_PRIVATE (self);
RequestItem *request_item;
while ((request_item = c_list_first_entry (&priv->request_queue_lst_head,
RequestItem,
request_queue_lst)))
_request_item_free (request_item);
}
static void
prepare_one_interface (NMDnsSystemdResolved *self, InterfaceConfig *ic)
{
NMDnsSystemdResolvedPrivate *priv = NM_DNS_SYSTEMD_RESOLVED_GET_PRIVATE (self);
GVariantBuilder dns, domains;
NMCListElem *elem;
NMSettingConnectionMdns mdns = NM_SETTING_CONNECTION_MDNS_DEFAULT;
NMSettingConnectionLlmnr llmnr = NM_SETTING_CONNECTION_LLMNR_DEFAULT;
const char *mdns_arg = NULL, *llmnr_arg = NULL;
g_variant_builder_init (&dns, G_VARIANT_TYPE ("(ia(iay))"));
g_variant_builder_add (&dns, "i", ic->ifindex);
g_variant_builder_open (&dns, G_VARIANT_TYPE ("a(iay)"));
g_variant_builder_init (&domains, G_VARIANT_TYPE ("(ia(sb))"));
g_variant_builder_add (&domains, "i", ic->ifindex);
g_variant_builder_open (&domains, G_VARIANT_TYPE ("a(sb)"));
c_list_for_each_entry (elem, &ic->configs_lst_head, lst) {
NMDnsIPConfigData *data = elem->data;
NMIPConfig *ip_config = data->ip_config;
update_add_ip_config (self, &dns, &domains, data);
if (NM_IS_IP4_CONFIG (ip_config)) {
mdns = NM_MAX (mdns, nm_ip4_config_mdns_get (NM_IP4_CONFIG (ip_config)));
llmnr = NM_MAX (llmnr, nm_ip4_config_llmnr_get (NM_IP4_CONFIG (ip_config)));
}
}
g_variant_builder_close (&dns);
g_variant_builder_close (&domains);
switch (mdns) {
case NM_SETTING_CONNECTION_MDNS_NO:
mdns_arg = "no";
break;
case NM_SETTING_CONNECTION_MDNS_RESOLVE:
mdns_arg = "resolve";
break;
case NM_SETTING_CONNECTION_MDNS_YES:
mdns_arg = "yes";
break;
case NM_SETTING_CONNECTION_MDNS_DEFAULT:
mdns_arg = "";
break;
}
nm_assert (mdns_arg);
switch (llmnr) {
case NM_SETTING_CONNECTION_LLMNR_NO:
llmnr_arg = "no";
break;
case NM_SETTING_CONNECTION_LLMNR_RESOLVE:
llmnr_arg = "resolve";
break;
case NM_SETTING_CONNECTION_LLMNR_YES:
llmnr_arg = "yes";
break;
case NM_SETTING_CONNECTION_LLMNR_DEFAULT:
llmnr_arg = "";
break;
}
nm_assert (llmnr_arg);
_request_item_append (&priv->request_queue_lst_head,
"SetLinkDNS",
g_variant_builder_end (&dns));
_request_item_append (&priv->request_queue_lst_head,
"SetLinkDomains",
g_variant_builder_end (&domains));
_request_item_append (&priv->request_queue_lst_head,
"SetLinkMulticastDNS",
g_variant_new ("(is)", ic->ifindex, mdns_arg ?: ""));
_request_item_append (&priv->request_queue_lst_head,
"SetLinkLLMNR",
g_variant_new ("(is)", ic->ifindex, llmnr_arg ?: ""));
}
static void
send_updates (NMDnsSystemdResolved *self)
{
NMDnsSystemdResolvedPrivate *priv = NM_DNS_SYSTEMD_RESOLVED_GET_PRIVATE (self);
RequestItem *request_item;
if (c_list_is_empty (&priv->request_queue_lst_head)) {
/* nothing to do. */
return;
}
if (!priv->dbus_initied) {
_LOGT ("send-updates: D-Bus connection not ready");
return;
}
if (!priv->dbus_has_owner) {
if (priv->try_start_blocked) {
/* we have no name owner and we already tried poking the service to
* autostart. */
_LOGT ("send-updates: no name owner");
return;
}
_LOGT ("send-updates: no name owner. Try start service...");
priv->try_start_blocked = TRUE;
nm_dbus_connection_call_start_service_by_name (priv->dbus_connection,
SYSTEMD_RESOLVED_DBUS_SERVICE,
-1,
NULL,
NULL,
NULL);
return;
}
_LOGT ("send-updates: start %lu requests",
c_list_length (&priv->request_queue_lst_head));
nm_clear_g_cancellable (&priv->cancellable);
priv->cancellable = g_cancellable_new ();
while ((request_item = c_list_first_entry (&priv->request_queue_lst_head,
RequestItem,
request_queue_lst))) {
/* Above we explicitly call "StartServiceByName" trying to avoid D-Bus activating systmd-resolved
* multiple times. There is still a race, were we might hit this line although actually
* the service just quit this very moment. In that case, we would try to D-Bus activate the
* service multiple times during each call (something we wanted to avoid).
*
* But this is hard to avoid, because we'd have to check the error failure to detect the reason
* and retry. The race is not critical, because at worst it results in logging a warning
* about failure to start systemd.resolved. */
g_dbus_connection_call (priv->dbus_connection,
SYSTEMD_RESOLVED_DBUS_SERVICE,
SYSTEMD_RESOLVED_DBUS_PATH,
SYSTEMD_RESOLVED_MANAGER_IFACE,
request_item->operation,
request_item->argument,
NULL,
G_DBUS_CALL_FLAGS_NONE,
-1,
priv->cancellable,
call_done,
self);
_request_item_free (request_item);
}
}
static gboolean
update (NMDnsPlugin *plugin,
const NMGlobalDnsConfig *global_config,
const CList *ip_config_lst_head,
const char *hostname,
GError **error)
{
NMDnsSystemdResolved *self = NM_DNS_SYSTEMD_RESOLVED (plugin);
gs_unref_hashtable GHashTable *interfaces = NULL;
gs_free gpointer *interfaces_keys = NULL;
guint interfaces_len;
guint i;
NMDnsIPConfigData *ip_data;
interfaces = g_hash_table_new_full (nm_direct_hash, NULL,
NULL, (GDestroyNotify) _interface_config_free);
c_list_for_each_entry (ip_data, ip_config_lst_head, ip_config_lst) {
InterfaceConfig *ic = NULL;
int ifindex;
ifindex = ip_data->data->ifindex;
nm_assert (ifindex == nm_ip_config_get_ifindex (ip_data->ip_config));
ic = g_hash_table_lookup (interfaces, GINT_TO_POINTER (ifindex));
if (!ic) {
ic = g_slice_new (InterfaceConfig);
ic->ifindex = ifindex;
c_list_init (&ic->configs_lst_head);
g_hash_table_insert (interfaces, GINT_TO_POINTER (ifindex), ic);
}
c_list_link_tail (&ic->configs_lst_head,
&nm_c_list_elem_new_stale (ip_data)->lst);
}
free_pending_updates (self);
interfaces_keys = nm_utils_hash_keys_to_array (interfaces,
nm_cmp_int2ptr_p_with_data,
NULL,
&interfaces_len);
for (i = 0; i < interfaces_len; i++) {
InterfaceConfig *ic = g_hash_table_lookup (interfaces, GINT_TO_POINTER (interfaces_keys[i]));
prepare_one_interface (self, ic);
}
send_updates (self);
return TRUE;
}
/*****************************************************************************/
static void
name_owner_changed (NMDnsSystemdResolved *self,
const char *owner)
{
NMDnsSystemdResolvedPrivate *priv = NM_DNS_SYSTEMD_RESOLVED_GET_PRIVATE (self);
owner = nm_str_not_empty (owner);
if (!owner)
_LOGT ("D-Bus name for systemd-resolved has no owner");
else
_LOGT ("D-Bus name for systemd-resolved has owner %s", owner);
priv->dbus_has_owner = !!owner;
if (owner)
priv->try_start_blocked = FALSE;
send_updates (self);
}
static void
name_owner_changed_cb (GDBusConnection *connection,
const char *sender_name,
const char *object_path,
const char *interface_name,
const char *signal_name,
GVariant *parameters,
gpointer user_data)
{
NMDnsSystemdResolved *self = user_data;
NMDnsSystemdResolvedPrivate *priv = NM_DNS_SYSTEMD_RESOLVED_GET_PRIVATE (self);
const char *new_owner;
if (!g_variant_is_of_type (parameters, G_VARIANT_TYPE ("(sss)")))
return;
g_variant_get (parameters,
"(&s&s&s)",
NULL,
NULL,
&new_owner);
if (!priv->dbus_initied) {
/* There was a race and we got a NameOwnerChanged signal before GetNameOwner
* returns. */
priv->dbus_initied = TRUE;
nm_clear_g_cancellable (&priv->cancellable);
}
name_owner_changed (user_data, new_owner);
}
static void
get_name_owner_cb (const char *name_owner,
GError *error,
gpointer user_data)
{
NMDnsSystemdResolved *self;
NMDnsSystemdResolvedPrivate *priv;
if ( !name_owner
&& g_error_matches (error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
return;
self = user_data;
priv = NM_DNS_SYSTEMD_RESOLVED_GET_PRIVATE (self);
g_clear_object (&priv->cancellable);
priv->dbus_initied = TRUE;
name_owner_changed (self, name_owner);
}
/*****************************************************************************/
gboolean
nm_dns_systemd_resolved_is_running (NMDnsSystemdResolved *self)
{
NMDnsSystemdResolvedPrivate *priv;
g_return_val_if_fail (NM_IS_DNS_SYSTEMD_RESOLVED (self), FALSE);
priv = NM_DNS_SYSTEMD_RESOLVED_GET_PRIVATE (self);
return priv->dbus_initied
&& ( priv->dbus_has_owner
|| !priv->try_start_blocked);
}
/*****************************************************************************/
static void
nm_dns_systemd_resolved_init (NMDnsSystemdResolved *self)
{
NMDnsSystemdResolvedPrivate *priv = NM_DNS_SYSTEMD_RESOLVED_GET_PRIVATE (self);
c_list_init (&priv->request_queue_lst_head);
priv->dbus_connection = nm_g_object_ref (NM_MAIN_DBUS_CONNECTION_GET);
if (!priv->dbus_connection) {
_LOGD ("no D-Bus connection");
return;
}
priv->name_owner_changed_id = nm_dbus_connection_signal_subscribe_name_owner_changed (priv->dbus_connection,
SYSTEMD_RESOLVED_DBUS_SERVICE,
name_owner_changed_cb,
self,
NULL);
priv->cancellable = g_cancellable_new ();
nm_dbus_connection_call_get_name_owner (priv->dbus_connection,
SYSTEMD_RESOLVED_DBUS_SERVICE,
-1,
priv->cancellable,
get_name_owner_cb,
self);
}
NMDnsPlugin *
nm_dns_systemd_resolved_new (void)
{
return g_object_new (NM_TYPE_DNS_SYSTEMD_RESOLVED, NULL);
}
static void
dispose (GObject *object)
{
NMDnsSystemdResolved *self = NM_DNS_SYSTEMD_RESOLVED (object);
NMDnsSystemdResolvedPrivate *priv = NM_DNS_SYSTEMD_RESOLVED_GET_PRIVATE (self);
free_pending_updates (self);
nm_clear_g_dbus_connection_signal (priv->dbus_connection,
&priv->name_owner_changed_id);
nm_clear_g_cancellable (&priv->cancellable);
g_clear_object (&priv->dbus_connection);
G_OBJECT_CLASS (nm_dns_systemd_resolved_parent_class)->dispose (object);
}
static void
nm_dns_systemd_resolved_class_init (NMDnsSystemdResolvedClass *dns_class)
{
NMDnsPluginClass *plugin_class = NM_DNS_PLUGIN_CLASS (dns_class);
GObjectClass *object_class = G_OBJECT_CLASS (dns_class);
object_class->dispose = dispose;
plugin_class->plugin_name = "systemd-resolved";
plugin_class->is_caching = TRUE;
plugin_class->update = update;
}