diff options
Diffstat (limited to 'src/nm-hostname-manager.c')
| -rw-r--r-- | src/nm-hostname-manager.c | 664 |
1 files changed, 664 insertions, 0 deletions
diff --git a/src/nm-hostname-manager.c b/src/nm-hostname-manager.c new file mode 100644 index 00000000..f569ab86 --- /dev/null +++ b/src/nm-hostname-manager.c @@ -0,0 +1,664 @@ +/* -*- Mode: C; tab-width: 4; indent-tabs-mode: t; c-basic-offset: 4 -*- */ +/* NetworkManager + * + * This program 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. + * + * This program 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 this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + * + * (C) Copyright 2017 Red Hat, Inc. + */ + +#include "nm-default.h" + +#include "nm-hostname-manager.h" + +#include <sys/stat.h> +#include <errno.h> +#include <string.h> + +#if HAVE_SELINUX +#include <selinux/selinux.h> +#endif + +#include "nm-common-macros.h" +#include "nm-dbus-interface.h" +#include "nm-connection.h" +#include "nm-utils.h" +#include "nm-core-internal.h" + +#include "NetworkManagerUtils.h" + +/*****************************************************************************/ + +#define HOSTNAMED_SERVICE_NAME "org.freedesktop.hostname1" +#define HOSTNAMED_SERVICE_PATH "/org/freedesktop/hostname1" +#define HOSTNAMED_SERVICE_INTERFACE "org.freedesktop.hostname1" + +#define HOSTNAME_FILE_DEFAULT "/etc/hostname" +#define HOSTNAME_FILE_UCASE_HOSTNAME "/etc/HOSTNAME" +#define HOSTNAME_FILE_GENTOO "/etc/conf.d/hostname" + +#define IFCFG_DIR SYSCONFDIR "/sysconfig/network" +#define CONF_DHCP IFCFG_DIR "/dhcp" + +#if (defined(HOSTNAME_PERSIST_SUSE) + defined(HOSTNAME_PERSIST_SLACKWARE) + defined(HOSTNAME_PERSIST_GENTOO)) > 1 +#error "Can only define one of HOSTNAME_PERSIST_*" +#endif + +#if defined(HOSTNAME_PERSIST_SUSE) +#define HOSTNAME_FILE HOSTNAME_FILE_UCASE_HOSTNAME +#elif defined(HOSTNAME_PERSIST_SLACKWARE) +#define HOSTNAME_FILE HOSTNAME_FILE_UCASE_HOSTNAME +#elif defined(HOSTNAME_PERSIST_GENTOO) +#define HOSTNAME_FILE HOSTNAME_FILE_GENTOO +#else +#define HOSTNAME_FILE HOSTNAME_FILE_DEFAULT +#endif + +/*****************************************************************************/ + +NM_GOBJECT_PROPERTIES_DEFINE (NMHostnameManager, + PROP_HOSTNAME, +); + +typedef struct { + char *current_hostname; + GFileMonitor *monitor; + GFileMonitor *dhcp_monitor; + gulong monitor_id; + gulong dhcp_monitor_id; + GDBusProxy *hostnamed_proxy; +} NMHostnameManagerPrivate; + +struct _NMHostnameManager { + GObject parent; + NMHostnameManagerPrivate _priv; +}; + +struct _NMHostnameManagerClass { + GObjectClass parent; +}; + +G_DEFINE_TYPE (NMHostnameManager, nm_hostname_manager, G_TYPE_OBJECT); + +#define NM_HOSTNAME_MANAGER_GET_PRIVATE(self) _NM_GET_PRIVATE (self, NMHostnameManager, NM_IS_HOSTNAME_MANAGER) + +NM_DEFINE_SINGLETON_GETTER (NMHostnameManager, nm_hostname_manager_get, NM_TYPE_HOSTNAME_MANAGER); + +/*****************************************************************************/ + +#define _NMLOG_DOMAIN LOGD_CORE +#define _NMLOG(level, ...) __NMLOG_DEFAULT (level, _NMLOG_DOMAIN, "hostname", __VA_ARGS__) + +/*****************************************************************************/ + +#if defined(HOSTNAME_PERSIST_GENTOO) +static gchar * +read_hostname_gentoo (const char *path) +{ + gs_free char *contents = NULL; + gs_strfreev char **all_lines = NULL; + const char *tmp; + guint i; + + if (!g_file_get_contents (path, &contents, NULL, NULL)) + return NULL; + + all_lines = g_strsplit (contents, "\n", 0); + for (i = 0; all_lines[i]; i++) { + g_strstrip (all_lines[i]); + if (all_lines[i][0] == '#' || all_lines[i][0] == '\0') + continue; + if (g_str_has_prefix (all_lines[i], "hostname=")) { + tmp = &all_lines[i][NM_STRLEN ("hostname=")]; + return g_shell_unquote (tmp, NULL); + } + } + return NULL; +} +#endif + +#if defined(HOSTNAME_PERSIST_SLACKWARE) +static gchar * +read_hostname_slackware (const char *path) +{ + gs_free char *contents = NULL; + gs_strfreev char **all_lines = NULL; + char *tmp; + guint i, j = 0; + + if (!g_file_get_contents (path, &contents, NULL, NULL)) + return NULL; + + all_lines = g_strsplit (contents, "\n", 0); + for (i = 0; all_lines[i]; i++) { + g_strstrip (all_lines[i]); + if (all_lines[i][0] == '#' || all_lines[i][0] == '\0') + continue; + tmp = &all_lines[i][0]; + /* We only want up to the first '.' -- the rest of the */ + /* fqdn is defined in /etc/hosts */ + while (tmp[j] != '\0') { + if (tmp[j] == '.') { + tmp[j] = '\0'; + break; + } + j++; + } + return g_shell_unquote (tmp, NULL); + } + return NULL; +} +#endif + +#if defined(HOSTNAME_PERSIST_SUSE) +static gboolean +hostname_is_dynamic (void) +{ + GIOChannel *channel; + char *str = NULL; + gboolean dynamic = FALSE; + + channel = g_io_channel_new_file (CONF_DHCP, "r", NULL); + if (!channel) + return dynamic; + + while (g_io_channel_read_line (channel, &str, NULL, NULL, NULL) != G_IO_STATUS_EOF) { + if (str) { + g_strstrip (str); + if (g_str_has_prefix (str, "DHCLIENT_SET_HOSTNAME=")) + dynamic = strcmp (&str[NM_STRLEN ("DHCLIENT_SET_HOSTNAME=")], "\"yes\"") == 0; + g_free (str); + } + } + + g_io_channel_shutdown (channel, FALSE, NULL); + g_io_channel_unref (channel); + + return dynamic; +} +#endif + +/* Returns an allocated string which the caller owns and must eventually free */ +char * +nm_hostname_manager_read_hostname (NMHostnameManager *self) +{ + NMHostnameManagerPrivate *priv = NM_HOSTNAME_MANAGER_GET_PRIVATE (self); + char *hostname = NULL; + + if (priv->hostnamed_proxy) { + hostname = g_strdup (priv->current_hostname); + goto out; + } + +#if defined(HOSTNAME_PERSIST_SUSE) + if (priv->dhcp_monitor_id && hostname_is_dynamic ()) + return NULL; +#endif + +#if defined(HOSTNAME_PERSIST_GENTOO) + hostname = read_hostname_gentoo (HOSTNAME_FILE); +#elif defined(HOSTNAME_PERSIST_SLACKWARE) + hostname = read_hostname_slackware (HOSTNAME_FILE); +#else + if (g_file_get_contents (HOSTNAME_FILE, &hostname, NULL, NULL)) + g_strchomp (hostname); +#endif + +out: + if (hostname && !hostname[0]) { + g_free (hostname); + return NULL; + } + + return hostname; +} + +/*****************************************************************************/ + +const char * +nm_hostname_manager_get_hostname (NMHostnameManager *self) +{ + g_return_val_if_fail (NM_IS_HOSTNAME_MANAGER (self), NULL); + return NM_HOSTNAME_MANAGER_GET_PRIVATE (self)->current_hostname; +} + +static void +_set_hostname_take (NMHostnameManager *self, char *hostname) +{ + NMHostnameManagerPrivate *priv = NM_HOSTNAME_MANAGER_GET_PRIVATE (self); + + _LOGI ("hostname changed from %s%s%s to %s%s%s", + NM_PRINT_FMT_QUOTED (priv->current_hostname, "\"", priv->current_hostname, "\"", "(none)"), + NM_PRINT_FMT_QUOTED (hostname, "\"", hostname, "\"", "(none)")); + + g_free (priv->current_hostname); + priv->current_hostname = hostname; + _notify (self, PROP_HOSTNAME); +} + +static void +_set_hostname (NMHostnameManager *self, const char *hostname) +{ + NMHostnameManagerPrivate *priv = NM_HOSTNAME_MANAGER_GET_PRIVATE (self); + + hostname = nm_str_not_empty (hostname); + if (!nm_streq0 (hostname, priv->current_hostname)) + _set_hostname_take (self, g_strdup (hostname)); +} + +static void +_set_hostname_read (NMHostnameManager *self) +{ + NMHostnameManagerPrivate *priv = NM_HOSTNAME_MANAGER_GET_PRIVATE (self); + char *hostname; + + if (priv->hostnamed_proxy) { + /* read-hostname returns the current hostname with hostnamed. */ + return; + } + + hostname = nm_hostname_manager_read_hostname (self); + + if (nm_streq0 (hostname, priv->current_hostname)) { + g_free (hostname); + return; + } + + _set_hostname_take (self, hostname); +} + +/*****************************************************************************/ + +typedef struct { + char *hostname; + NMHostnameManagerSetHostnameCb cb; + gpointer user_data; +} SetHostnameInfo; + +static void +set_transient_hostname_done (GObject *object, + GAsyncResult *res, + gpointer user_data) +{ + GDBusProxy *proxy = G_DBUS_PROXY (object); + gs_free SetHostnameInfo *info = user_data; + gs_unref_variant GVariant *result = NULL; + gs_free_error GError *error = NULL; + + result = g_dbus_proxy_call_finish (proxy, res, &error); + + if (error) { + _LOGW ("couldn't set the system hostname to '%s' using hostnamed: %s", + info->hostname, error->message); + } + + info->cb (info->hostname, !error, info->user_data); + g_free (info->hostname); +} + +void +nm_hostname_manager_set_transient_hostname (NMHostnameManager *self, + const char *hostname, + NMHostnameManagerSetHostnameCb cb, + gpointer user_data) +{ + NMHostnameManagerPrivate *priv; + SetHostnameInfo *info; + + g_return_if_fail (NM_IS_HOSTNAME_MANAGER (self)); + + priv = NM_HOSTNAME_MANAGER_GET_PRIVATE (self); + + if (!priv->hostnamed_proxy) { + cb (hostname, FALSE, user_data); + return; + } + + info = g_new0 (SetHostnameInfo, 1); + info->hostname = g_strdup (hostname); + info->cb = cb; + info->user_data = user_data; + + g_dbus_proxy_call (priv->hostnamed_proxy, + "SetHostname", + g_variant_new ("(sb)", hostname, FALSE), + G_DBUS_CALL_FLAGS_NONE, + -1, + NULL, + set_transient_hostname_done, + info); +} + +gboolean +nm_hostname_manager_get_transient_hostname (NMHostnameManager *self, char **hostname) +{ + NMHostnameManagerPrivate *priv = NM_HOSTNAME_MANAGER_GET_PRIVATE (self); + GVariant *v_hostname; + + if (!priv->hostnamed_proxy) + return FALSE; + + v_hostname = g_dbus_proxy_get_cached_property (priv->hostnamed_proxy, + "Hostname"); + if (!v_hostname) { + _LOGT ("transient hostname retrieval failed"); + return FALSE; + } + + *hostname = g_variant_dup_string (v_hostname, NULL); + g_variant_unref (v_hostname); + + return TRUE; +} + +gboolean +nm_hostname_manager_write_hostname (NMHostnameManager *self, const char *hostname) +{ + NMHostnameManagerPrivate *priv; + char *hostname_eol; + gboolean ret; + gs_free_error GError *error = NULL; + const char *file = HOSTNAME_FILE; + gs_free char *link_path = NULL; + gs_unref_variant GVariant *var = NULL; + struct stat file_stat; +#if HAVE_SELINUX + security_context_t se_ctx_prev = NULL, se_ctx = NULL; + mode_t st_mode = 0; +#endif + + g_return_val_if_fail (NM_IS_HOSTNAME_MANAGER (self), FALSE); + + priv = NM_HOSTNAME_MANAGER_GET_PRIVATE (self); + + if (priv->hostnamed_proxy) { + var = g_dbus_proxy_call_sync (priv->hostnamed_proxy, + "SetStaticHostname", + g_variant_new ("(sb)", hostname, FALSE), + G_DBUS_CALL_FLAGS_NONE, + -1, + NULL, + &error); + if (error) + _LOGW ("could not set hostname: %s", error->message); + + return !error; + } + + /* If the hostname file is a symbolic link, follow it to find where the + * real file is located, otherwise g_file_set_contents will attempt to + * replace the link with a plain file. + */ + if ( lstat (file, &file_stat) == 0 + && S_ISLNK (file_stat.st_mode) + && (link_path = nm_utils_read_link_absolute (file, NULL))) + file = link_path; + +#if HAVE_SELINUX + /* Get default context for hostname file and set it for fscreate */ + if (stat (file, &file_stat) == 0) + st_mode = file_stat.st_mode; + matchpathcon (file, st_mode, &se_ctx); + matchpathcon_fini (); + getfscreatecon (&se_ctx_prev); + setfscreatecon (se_ctx); +#endif + +#if defined (HOSTNAME_PERSIST_GENTOO) + hostname_eol = g_strdup_printf ("#Generated by NetworkManager\n" + "hostname=\"%s\"\n", hostname); +#else + hostname_eol = g_strdup_printf ("%s\n", hostname); +#endif + + ret = g_file_set_contents (file, hostname_eol, -1, &error); + +#if HAVE_SELINUX + /* Restore previous context and cleanup */ + setfscreatecon (se_ctx_prev); + freecon (se_ctx); + freecon (se_ctx_prev); +#endif + + g_free (hostname_eol); + + if (!ret) { + _LOGW ("could not save hostname to %s: %s", file, error->message); + return FALSE; + } + + return TRUE; +} + +gboolean +nm_hostname_manager_validate_hostname (const char *hostname) +{ + const char *p; + gboolean dot = TRUE; + + if (!hostname || !hostname[0]) + return FALSE; + + for (p = hostname; *p; p++) { + if (*p == '.') { + if (dot) + return FALSE; + dot = TRUE; + } else { + if (!g_ascii_isalnum (*p) && (*p != '-') && (*p != '_')) + return FALSE; + dot = FALSE; + } + } + + if (dot) + return FALSE; + + return (p - hostname <= HOST_NAME_MAX); +} + +static void +hostname_file_changed_cb (GFileMonitor *monitor, + GFile *file, + GFile *other_file, + GFileMonitorEvent event_type, + gpointer user_data) +{ + _set_hostname_read (user_data); +} + +/*****************************************************************************/ + +static void +hostnamed_properties_changed (GDBusProxy *proxy, + GVariant *changed_properties, + char **invalidated_properties, + gpointer user_data) +{ + NMHostnameManager *self = user_data; + NMHostnameManagerPrivate *priv = NM_HOSTNAME_MANAGER_GET_PRIVATE (self); + GVariant *v_hostname; + + v_hostname = g_dbus_proxy_get_cached_property (priv->hostnamed_proxy, + "StaticHostname"); + if (v_hostname) { + _set_hostname (self, g_variant_get_string (v_hostname, NULL)); + g_variant_unref (v_hostname); + } +} + +static void +setup_hostname_file_monitors (NMHostnameManager *self) +{ + NMHostnameManagerPrivate *priv = NM_HOSTNAME_MANAGER_GET_PRIVATE (self); + GFileMonitor *monitor; + const char *path = HOSTNAME_FILE; + char *link_path = NULL; + struct stat file_stat; + GFile *file; + + /* resolve the path to the hostname file if it is a symbolic link */ + if ( lstat(path, &file_stat) == 0 + && S_ISLNK (file_stat.st_mode) + && (link_path = nm_utils_read_link_absolute (path, NULL))) { + path = link_path; + if ( lstat(link_path, &file_stat) == 0 + && S_ISLNK (file_stat.st_mode)) { + _LOGW ("only one level of symbolic link indirection is allowed when monitoring " + HOSTNAME_FILE); + } + } + + /* monitor changes to hostname file */ + file = g_file_new_for_path (path); + monitor = g_file_monitor_file (file, G_FILE_MONITOR_NONE, NULL, NULL); + g_object_unref (file); + g_free(link_path); + if (monitor) { + priv->monitor_id = g_signal_connect (monitor, "changed", + G_CALLBACK (hostname_file_changed_cb), + self); + priv->monitor = monitor; + } + +#if defined (HOSTNAME_PERSIST_SUSE) + /* monitor changes to dhcp file to know whether the hostname is valid */ + file = g_file_new_for_path (CONF_DHCP); + monitor = g_file_monitor_file (file, G_FILE_MONITOR_NONE, NULL, NULL); + g_object_unref (file); + if (monitor) { + priv->dhcp_monitor_id = g_signal_connect (monitor, "changed", + G_CALLBACK (hostname_file_changed_cb), + self); + priv->dhcp_monitor = monitor; + } +#endif + + _set_hostname_read (self); +} + +/*****************************************************************************/ + +static void +get_property (GObject *object, guint prop_id, + GValue *value, GParamSpec *pspec) +{ + NMHostnameManager *self = NM_HOSTNAME_MANAGER (object); + + switch (prop_id) { + case PROP_HOSTNAME: + g_value_set_string (value, nm_hostname_manager_get_hostname (self)); + break; + default: + G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); + break; + } +} + +/*****************************************************************************/ + +static void +nm_hostname_manager_init (NMHostnameManager *self) +{ +} + +static void +constructed (GObject *object) +{ + NMHostnameManager *self = NM_HOSTNAME_MANAGER (object); + NMHostnameManagerPrivate *priv = NM_HOSTNAME_MANAGER_GET_PRIVATE (self); + GDBusProxy *proxy; + GVariant *variant; + gs_free_error GError *error = NULL; + + proxy = g_dbus_proxy_new_for_bus_sync (G_BUS_TYPE_SYSTEM, 0, NULL, + HOSTNAMED_SERVICE_NAME, HOSTNAMED_SERVICE_PATH, + HOSTNAMED_SERVICE_INTERFACE, NULL, &error); + if (proxy) { + variant = g_dbus_proxy_get_cached_property (proxy, "StaticHostname"); + if (variant) { + _LOGI ("hostname: using hostnamed"); + priv->hostnamed_proxy = proxy; + g_signal_connect (proxy, "g-properties-changed", + G_CALLBACK (hostnamed_properties_changed), self); + hostnamed_properties_changed (proxy, NULL, NULL, self); + g_variant_unref (variant); + } else { + _LOGI ("hostname: couldn't get property from hostnamed"); + g_object_unref (proxy); + } + } else { + _LOGI ("hostname: hostnamed not used as proxy creation failed with: %s", + error->message); + g_clear_error (&error); + } + + if (!priv->hostnamed_proxy) + setup_hostname_file_monitors (self); + + G_OBJECT_CLASS (nm_hostname_manager_parent_class)->constructed (object); +} + +static void +dispose (GObject *object) +{ + NMHostnameManager *self = NM_HOSTNAME_MANAGER (object); + NMHostnameManagerPrivate *priv = NM_HOSTNAME_MANAGER_GET_PRIVATE (self); + + if (priv->hostnamed_proxy) { + g_signal_handlers_disconnect_by_func (priv->hostnamed_proxy, + G_CALLBACK (hostnamed_properties_changed), + self); + g_clear_object (&priv->hostnamed_proxy); + } + + if (priv->monitor) { + if (priv->monitor_id) + g_signal_handler_disconnect (priv->monitor, priv->monitor_id); + + g_file_monitor_cancel (priv->monitor); + g_clear_object (&priv->monitor); + } + + if (priv->dhcp_monitor) { + if (priv->dhcp_monitor_id) + g_signal_handler_disconnect (priv->dhcp_monitor, + priv->dhcp_monitor_id); + + g_file_monitor_cancel (priv->dhcp_monitor); + g_clear_object (&priv->dhcp_monitor); + } + + nm_clear_g_free (&priv->current_hostname); + + G_OBJECT_CLASS (nm_hostname_manager_parent_class)->dispose (object); +} + +static void +nm_hostname_manager_class_init (NMHostnameManagerClass *class) +{ + GObjectClass *object_class = G_OBJECT_CLASS (class); + + object_class->constructed = constructed; + object_class->get_property = get_property; + object_class->dispose = dispose; + + obj_properties[PROP_HOSTNAME] = + g_param_spec_string (NM_HOSTNAME_MANAGER_HOSTNAME, "", "", + NULL, + G_PARAM_READABLE | + G_PARAM_STATIC_STRINGS); + + g_object_class_install_properties (object_class, _PROPERTY_ENUMS_LAST, obj_properties); +} |