/* -*- Mode: C; tab-width: 4; indent-tabs-mode: t; c-basic-offset: 4 -*- */
/* NetworkManager -- Network link manager
 *
 * 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.
 *
 * Copyright 2004 - 2014 Red Hat, Inc.
 * Copyright 2005 - 2008 Novell, Inc.
 */

#include "nm-default.h"

#include "nm-core-utils.h"

#include <errno.h>
#include <fcntl.h>
#include <string.h>
#include <poll.h>
#include <unistd.h>
#include <stdlib.h>
#include <resolv.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <linux/if.h>
#include <linux/if_infiniband.h>
#include <net/ethernet.h>

#include "nm-utils.h"
#include "nm-core-internal.h"
#include "nm-setting-connection.h"
#include "nm-setting-ip4-config.h"
#include "nm-setting-ip6-config.h"
#include "nm-setting-wireless.h"
#include "nm-setting-wireless-security.h"

/*
 * Some toolchains (E.G. uClibc 0.9.33 and earlier) don't export
 * CLOCK_BOOTTIME even though the kernel supports it, so provide a
 * local definition
 */
#ifndef CLOCK_BOOTTIME
#define CLOCK_BOOTTIME 7
#endif

G_STATIC_ASSERT (sizeof (NMUtilsTestFlags) <= sizeof (int));
static int _nm_utils_testing = 0;

gboolean
nm_utils_get_testing_initialized ()
{
	NMUtilsTestFlags flags;

	flags = (NMUtilsTestFlags) _nm_utils_testing;
	if (flags == NM_UTILS_TEST_NONE)
		flags = (NMUtilsTestFlags) g_atomic_int_get (&_nm_utils_testing);
	return flags != NM_UTILS_TEST_NONE;
}

NMUtilsTestFlags
nm_utils_get_testing ()
{
	NMUtilsTestFlags flags;

	flags = (NMUtilsTestFlags) _nm_utils_testing;
	if (flags != NM_UTILS_TEST_NONE) {
		/* Flags already initialized. Return them. */
		return flags & NM_UTILS_TEST_ALL;
	}

	/* Accessing nm_utils_get_testing() causes us to set the flags to initialized.
	 * Detecting running tests also based on g_test_initialized(). */
	flags = _NM_UTILS_TEST_INITIALIZED;
	if (g_test_initialized ())
		flags |= _NM_UTILS_TEST_GENERAL;

	if (g_atomic_int_compare_and_exchange (&_nm_utils_testing, 0, (int) flags)) {
		/* Done. We set it. */
		return flags & NM_UTILS_TEST_ALL;
	}
	/* It changed in the meantime (??). Re-read the value. */
	return ((NMUtilsTestFlags) _nm_utils_testing) & NM_UTILS_TEST_ALL;
}

void
_nm_utils_set_testing (NMUtilsTestFlags flags)
{
	g_assert (!NM_FLAGS_ANY (flags, ~NM_UTILS_TEST_ALL));

	/* mask out everything except ALL, and always set GENERAL. */
	flags = (flags & NM_UTILS_TEST_ALL) | (_NM_UTILS_TEST_GENERAL | _NM_UTILS_TEST_INITIALIZED);

	if (!g_atomic_int_compare_and_exchange (&_nm_utils_testing, 0, (int) flags)) {
		/* We only allow setting _nm_utils_set_testing() once, before fetching the
		 * value with nm_utils_get_testing(). */
		g_return_if_reached ();
	}
}

/*****************************************************************************/

static GSList *_singletons = NULL;
static gboolean _singletons_shutdown = FALSE;

static void
_nm_singleton_instance_weak_cb (gpointer data,
                                GObject *where_the_object_was)
{
	_singletons = g_slist_remove (_singletons, where_the_object_was);
}

static void __attribute__((destructor))
_nm_singleton_instance_destroy (void)
{
	_singletons_shutdown = TRUE;

	while (_singletons) {
		GObject *instance = _singletons->data;

		_singletons = g_slist_delete_link (_singletons, _singletons);

		g_object_weak_unref (instance, _nm_singleton_instance_weak_cb, NULL);

		if (instance->ref_count > 1)
			nm_log_dbg (LOGD_CORE, "disown %s singleton (%p)", G_OBJECT_TYPE_NAME (instance), instance);

		g_object_unref (instance);
	}
}

void
_nm_singleton_instance_register_destruction (GObject *instance)
{
	g_return_if_fail (G_IS_OBJECT (instance));

	/* Don't allow registration after shutdown. We only destroy the singletons
	 * once. */
	g_return_if_fail (!_singletons_shutdown);

	g_object_weak_ref (instance, _nm_singleton_instance_weak_cb, NULL);

	_singletons = g_slist_prepend (_singletons, instance);
}

/*****************************************************************************/

/*
 * nm_ethernet_address_is_valid:
 * @addr: pointer to a binary or ASCII Ethernet address
 * @len: length of @addr, or -1 if @addr is ASCII
 *
 * Compares an Ethernet address against known invalid addresses.

 * Returns: %TRUE if @addr is a valid Ethernet address, %FALSE if it is not.
 */
gboolean
nm_ethernet_address_is_valid (gconstpointer addr, gssize len)
{
	guint8 invalid_addr[4][ETH_ALEN] = {
	    {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF},
	    {0x00, 0x00, 0x00, 0x00, 0x00, 0x00},
	    {0x44, 0x44, 0x44, 0x44, 0x44, 0x44},
	    {0x00, 0x30, 0xb4, 0x00, 0x00, 0x00}, /* prism54 dummy MAC */
	};
	guint8 addr_bin[ETH_ALEN];
	guint i;

	if (!addr) {
		g_return_val_if_fail (len == -1 || len == ETH_ALEN, FALSE);
		return FALSE;
	}

	if (len == -1) {
		if (!nm_utils_hwaddr_aton (addr, addr_bin, ETH_ALEN))
			return FALSE;
		addr = addr_bin;
	} else if (len != ETH_ALEN)
		g_return_val_if_reached (FALSE);

	/* Check for multicast address */
	if ((((guint8 *) addr)[0]) & 0x01)
		return FALSE;

	for (i = 0; i < G_N_ELEMENTS (invalid_addr); i++) {
		if (nm_utils_hwaddr_matches (addr, ETH_ALEN, invalid_addr[i], ETH_ALEN))
			return FALSE;
	}

	return TRUE;
}

gconstpointer
nm_utils_ipx_address_clear_host_address (int family, gpointer dst, gconstpointer src, guint8 plen)
{
	g_return_val_if_fail (src, NULL);
	g_return_val_if_fail (dst, NULL);

	switch (family) {
	case AF_INET:
		g_return_val_if_fail (plen <= 32, NULL);
		*((guint32 *) dst) = nm_utils_ip4_address_clear_host_address (*((guint32 *) src), plen);
		break;
	case AF_INET6:
		g_return_val_if_fail (plen <= 128, NULL);
		nm_utils_ip6_address_clear_host_address (dst, src, plen);
		break;
	default:
		g_return_val_if_reached (NULL);
	}
	return dst;
}

/* nm_utils_ip4_address_clear_host_address:
 * @addr: source ip6 address
 * @plen: prefix length of network
 *
 * returns: the input address, with the host address set to 0.
 */
in_addr_t
nm_utils_ip4_address_clear_host_address (in_addr_t addr, guint8 plen)
{
	return addr & nm_utils_ip4_prefix_to_netmask (plen);
}

/* nm_utils_ip6_address_clear_host_address:
 * @dst: destination output buffer, will contain the network part of the @src address
 * @src: source ip6 address
 * @plen: prefix length of network
 *
 * Note: this function is self assignment safe, to update @src inplace, set both
 * @dst and @src to the same destination.
 */
const struct in6_addr *
nm_utils_ip6_address_clear_host_address (struct in6_addr *dst, const struct in6_addr *src, guint8 plen)
{
	g_return_val_if_fail (plen <= 128, NULL);
	g_return_val_if_fail (src, NULL);
	g_return_val_if_fail (dst, NULL);

	if (plen < 128) {
		guint nbytes = plen / 8;
		guint nbits = plen % 8;

		if (nbytes && dst != src)
			memcpy (dst, src, nbytes);
		if (nbits) {
			dst->s6_addr[nbytes] = (src->s6_addr[nbytes] & (0xFF << (8 - nbits)));
			nbytes++;
		}
		if (nbytes <= 15)
			memset (&dst->s6_addr[nbytes], 0, 16 - nbytes);
	} else if (src != dst)
		*dst = *src;

	return dst;
}

gboolean
nm_utils_ip6_address_same_prefix (const struct in6_addr *addr_a, const struct in6_addr *addr_b, guint8 plen)
{
	int nbytes;
	guint8 t, m;

	if (plen >= 128)
		return memcmp (addr_a, addr_b, sizeof (struct in6_addr)) == 0;

	nbytes = plen / 8;
	if (nbytes) {
		if (memcmp (addr_a, addr_b, nbytes) != 0)
			return FALSE;
	}

	plen = plen % 8;
	if (plen == 0)
		return TRUE;

	m = ~((1 << (8 - plen)) - 1);
	t = ((((const guint8 *) addr_a))[nbytes]) ^ ((((const guint8 *) addr_b))[nbytes]);
	return (t & m) == 0;
}

/*****************************************************************************/

void
nm_utils_array_remove_at_indexes (GArray *array, const guint *indexes_to_delete, gsize len)
{
	gsize elt_size;
	guint index_to_delete;
	guint i_src;
	guint mm_src, mm_dst, mm_len;
	gsize i_itd;
	guint res_length;

	g_return_if_fail (array);
	if (!len)
		return;
	g_return_if_fail (indexes_to_delete);

	elt_size = g_array_get_element_size (array);

	i_itd = 0;
	index_to_delete = indexes_to_delete[0];
	if (index_to_delete >= array->len)
		g_return_if_reached ();

	res_length = array->len - 1;

	mm_dst = index_to_delete;
	mm_src = index_to_delete;
	mm_len = 0;

	for (i_src = index_to_delete; i_src < array->len; i_src++) {
		if (i_src < index_to_delete)
			mm_len++;
		else {
			/* we require indexes_to_delete to contain non-repeated, ascending
			 * indexes. Otherwise we would need to presort the indexes. */
			while (TRUE) {
				guint dd;

				if (i_itd + 1 >= len) {
					index_to_delete = G_MAXUINT;
					break;
				}

				dd = indexes_to_delete[++i_itd];
				if (dd > index_to_delete) {
					if (dd >= array->len)
						g_warn_if_reached ();
					else {
						g_assert (res_length > 0);
						res_length--;
					}
					index_to_delete = dd;
					break;
				}
				g_warn_if_reached ();
			}

			if (mm_len) {
				memmove (&array->data[mm_dst * elt_size],
				         &array->data[mm_src * elt_size],
				         mm_len * elt_size);
				mm_dst += mm_len;
				mm_src += mm_len + 1;
				mm_len = 0;
			} else
				mm_src++;
		}
	}
	if (mm_len) {
		memmove (&array->data[mm_dst * elt_size],
		         &array->data[mm_src * elt_size],
		         mm_len * elt_size);
	}
	g_array_set_size (array, res_length);
}

int
nm_spawn_process (const char *args, GError **error)
{
	GError *local = NULL;
	gint num_args;
	char **argv = NULL;
	int status = -1;

	g_return_val_if_fail (args != NULL, -1);
	g_return_val_if_fail (!error || !*error, -1);

	if (g_shell_parse_argv (args, &num_args, &argv, &local)) {
		g_spawn_sync ("/", argv, NULL, 0, NULL, NULL, NULL, NULL, &status, &local);
		g_strfreev (argv);
	}

	if (local) {
		nm_log_warn (LOGD_CORE, "could not spawn process '%s': %s", args, local->message);
		g_propagate_error (error, local);
	}

	return status;
}

static const char *
_trunk_first_line (char *str)
{
	char *s;

	s = strchr (str, '\n');
	if (s)
		s[0] = '\0';
	return str;
}

int
nm_utils_modprobe (GError **error, gboolean suppress_error_logging, const char *arg1, ...)
{
	gs_unref_ptrarray GPtrArray *argv = NULL;
	int exit_status;
	gs_free char *_log_str = NULL;
#define ARGV_TO_STR(argv)   (_log_str ? _log_str : (_log_str = g_strjoinv (" ", (char **) argv->pdata)))
	GError *local = NULL;
	va_list ap;
	NMLogLevel llevel = suppress_error_logging ? LOGL_DEBUG : LOGL_ERR;
	gs_free char *std_out = NULL, *std_err = NULL;

	g_return_val_if_fail (!error || !*error, -1);
	g_return_val_if_fail (arg1, -1);

	/* construct the argument list */
	argv = g_ptr_array_sized_new (4);
	g_ptr_array_add (argv, "/sbin/modprobe");
	g_ptr_array_add (argv, (char *) arg1);

	va_start (ap, arg1);
	while ((arg1 = va_arg (ap, const char *)))
		g_ptr_array_add (argv, (char *) arg1);
	va_end (ap);

	g_ptr_array_add (argv, NULL);

	nm_log_dbg (LOGD_CORE, "modprobe: '%s'", ARGV_TO_STR (argv));
	if (!g_spawn_sync (NULL, (char **) argv->pdata, NULL, 0, NULL, NULL, &std_out, &std_err, &exit_status, &local)) {
		nm_log (llevel, LOGD_CORE, "modprobe: '%s' failed: %s", ARGV_TO_STR (argv), local->message);
		g_propagate_error (error, local);
		return -1;
	} else if (exit_status != 0) {
		nm_log (llevel, LOGD_CORE, "modprobe: '%s' exited with error %d%s%s%s%s%s%s", ARGV_TO_STR (argv), exit_status,
		        std_out&&*std_out ? " (" : "", std_out&&*std_out ? _trunk_first_line (std_out) : "", std_out&&*std_out ? ")" : "",
		        std_err&&*std_err ? " (" : "", std_err&&*std_err ? _trunk_first_line (std_err) : "", std_err&&*std_err ? ")" : "");
	}

	return exit_status;
}

/**
 * nm_utils_get_start_time_for_pid:
 * @pid: the process identifier
 * @out_state: return the state character, like R, S, Z. See `man 5 proc`.
 * @out_ppid: parent process id
 *
 * Originally copied from polkit source (src/polkit/polkitunixprocess.c)
 * and adjusted.
 *
 * Returns: the timestamp when the process started (by parsing /proc/$PID/stat).
 * If an error occurs (e.g. the process does not exist), 0 is returned.
 *
 * The returned start time counts since boot, in the unit HZ (with HZ usually being (1/100) seconds)
 **/
guint64
nm_utils_get_start_time_for_pid (pid_t pid, char *out_state, pid_t *out_ppid)
{
	guint64 start_time;
	char filename[256];
	gs_free gchar *contents = NULL;
	size_t length;
	gs_strfreev gchar **tokens = NULL;
	guint num_tokens;
	gchar *p;
	char state = ' ';
	gint64 ppid = 0;

	start_time = 0;
	contents = NULL;

	g_return_val_if_fail (pid > 0, 0);

	nm_sprintf_buf (filename, "/proc/%"G_GUINT64_FORMAT"/stat", (guint64) pid);

	if (!g_file_get_contents (filename, &contents, &length, NULL))
		goto fail;

	/* start time is the token at index 19 after the '(process name)' entry - since only this
	 * field can contain the ')' character, search backwards for this to avoid malicious
	 * processes trying to fool us
	 */
	p = strrchr (contents, ')');
	if (p == NULL)
		goto fail;
	p += 2; /* skip ') ' */
	if (p - contents >= (int) length)
		goto fail;

	state = p[0];

	tokens = g_strsplit (p, " ", 0);

	num_tokens = g_strv_length (tokens);

	if (num_tokens < 20)
		goto fail;

	if (out_ppid) {
		ppid = _nm_utils_ascii_str_to_int64 (tokens[1], 10, 1, G_MAXINT, 0);
		if (ppid == 0)
			goto fail;
	}

	start_time = _nm_utils_ascii_str_to_int64 (tokens[19], 10, 1, G_MAXINT64, 0);
	if (start_time == 0)
		goto fail;

	NM_SET_OUT (out_state, state);
	NM_SET_OUT (out_ppid, ppid);
	return start_time;

fail:
	NM_SET_OUT (out_state, ' ');
	NM_SET_OUT (out_ppid, 0);
	return 0;
}

/*****************************************************************************/

typedef struct {
	pid_t pid;
	NMLogDomain log_domain;
	union {
		struct {
			gint64 wait_start_us;
			guint source_timeout_kill_id;
		} async;
		struct {
			gboolean success;
			int child_status;
		} sync;
	};
	NMUtilsKillChildAsyncCb callback;
	void *user_data;

	char log_name[1]; /* variable-length object, must be last element!! */
} KillChildAsyncData;

#define LOG_NAME_FMT "kill child process '%s' (%ld)"
#define LOG_NAME_PROCESS_FMT "kill process '%s' (%ld)"
#define LOG_NAME_ARGS log_name,(long)pid

static KillChildAsyncData *
_kc_async_data_alloc (pid_t pid, NMLogDomain log_domain, const char *log_name, NMUtilsKillChildAsyncCb callback, void *user_data)
{
	KillChildAsyncData *data;
	size_t log_name_len;

	/* append the name at the end of our KillChildAsyncData. */
	log_name_len = strlen (LOG_NAME_FMT) + 20 + strlen (log_name);
	data = g_malloc (sizeof (KillChildAsyncData) - 1 + log_name_len);
	g_snprintf (data->log_name, log_name_len, LOG_NAME_FMT, LOG_NAME_ARGS);

	data->pid = pid;
	data->user_data = user_data;
	data->callback = callback;
	data->log_domain = log_domain;

	return data;
}

#define KC_EXIT_TO_STRING_BUF_SIZE 128
static const char *
_kc_exit_to_string (char *buf, int exit)
#define _kc_exit_to_string(buf, exit) ( G_STATIC_ASSERT_EXPR(sizeof (buf) == KC_EXIT_TO_STRING_BUF_SIZE && sizeof ((buf)[0]) == 1), _kc_exit_to_string (buf, exit) )
{
	if (WIFEXITED (exit))
		g_snprintf (buf, KC_EXIT_TO_STRING_BUF_SIZE, "normally with status %d", WEXITSTATUS (exit));
	else if (WIFSIGNALED (exit))
		g_snprintf (buf, KC_EXIT_TO_STRING_BUF_SIZE, "by signal %d", WTERMSIG (exit));
	else
		g_snprintf (buf, KC_EXIT_TO_STRING_BUF_SIZE, "with unexpected status %d", exit);
	return buf;
}

static const char *
_kc_signal_to_string (int sig)
{
	switch (sig) {
	case 0:  return "no signal (0)";
	case SIGKILL:  return "SIGKILL (" G_STRINGIFY (SIGKILL) ")";
	case SIGTERM:  return "SIGTERM (" G_STRINGIFY (SIGTERM) ")";
	default:
		return "Unexpected signal";
	}
}

#define KC_WAITED_TO_STRING 100
static const char *
_kc_waited_to_string (char *buf, gint64 wait_start_us)
#define _kc_waited_to_string(buf, wait_start_us) ( G_STATIC_ASSERT_EXPR(sizeof (buf) == KC_WAITED_TO_STRING && sizeof ((buf)[0]) == 1), _kc_waited_to_string (buf, wait_start_us) )
{
	g_snprintf (buf, KC_WAITED_TO_STRING, " (%ld usec elapsed)", (long) (nm_utils_get_monotonic_timestamp_us () - wait_start_us));
	return buf;
}

static void
_kc_cb_watch_child (GPid pid, gint status, gpointer user_data)
{
	KillChildAsyncData *data = user_data;
	char buf_exit[KC_EXIT_TO_STRING_BUF_SIZE], buf_wait[KC_WAITED_TO_STRING];

	if (data->async.source_timeout_kill_id)
		g_source_remove (data->async.source_timeout_kill_id);

	nm_log_dbg (data->log_domain, "%s: terminated %s%s",
	            data->log_name, _kc_exit_to_string (buf_exit, status),
	            _kc_waited_to_string (buf_wait, data->async.wait_start_us));

	if (data->callback)
		data->callback (pid, TRUE, status, data->user_data);

	g_free (data);
}

static gboolean
_kc_cb_timeout_grace_period (void *user_data)
{
	KillChildAsyncData *data = user_data;
	int ret, errsv;

	data->async.source_timeout_kill_id = 0;

	if ((ret = kill (data->pid, SIGKILL)) != 0) {
		errsv = errno;
		/* ESRCH means, process does not exist or is already a zombie. */
		if (errsv != ESRCH) {
			nm_log_err (LOGD_CORE | data->log_domain, "%s: kill(SIGKILL) returned unexpected return value %d: (%s, %d)",
			            data->log_name, ret, strerror (errsv), errsv);
		}
	} else {
		nm_log_dbg (data->log_domain, "%s: process not terminated after %ld usec. Sending SIGKILL signal",
		            data->log_name, (long) (nm_utils_get_monotonic_timestamp_us () - data->async.wait_start_us));
	}

	return G_SOURCE_REMOVE;
}

static gboolean
_kc_invoke_callback_idle (gpointer user_data)
{
	KillChildAsyncData *data = user_data;

	if (data->sync.success) {
		char buf_exit[KC_EXIT_TO_STRING_BUF_SIZE];

		nm_log_dbg (data->log_domain, "%s: invoke callback: terminated %s",
		            data->log_name, _kc_exit_to_string (buf_exit, data->sync.child_status));
	} else
		nm_log_dbg (data->log_domain, "%s: invoke callback: killing child failed", data->log_name);

	data->callback (data->pid, data->sync.success, data->sync.child_status, data->user_data);
	g_free (data);

	return G_SOURCE_REMOVE;
}

static void
_kc_invoke_callback (pid_t pid, NMLogDomain log_domain, const char *log_name, NMUtilsKillChildAsyncCb callback, void *user_data, gboolean success, int child_status)
{
	KillChildAsyncData *data;

	if (!callback)
		return;

	data = _kc_async_data_alloc (pid, log_domain, log_name, callback, user_data);
	data->sync.success = success;
	data->sync.child_status = child_status;

	g_idle_add (_kc_invoke_callback_idle, data);
}

/* nm_utils_kill_child_async:
 * @pid: the process id of the process to kill
 * @sig: signal to send initially. Set to 0 to send not signal.
 * @log_domain: the logging domain used for logging (LOGD_NONE to suppress logging)
 * @log_name: for logging, the name of the processes to kill
 * @wait_before_kill_msec: Waittime in milliseconds before sending %SIGKILL signal. Set this value
 * to zero, not to send %SIGKILL. If @sig is already %SIGKILL, this parameter is ignored.
 * @callback: (allow-none): callback after the child terminated. This function will always
 *   be invoked asynchronously.
 * @user_data: passed on to callback
 *
 * Uses g_child_watch_add(), so note the glib comment: if you obtain pid from g_spawn_async() or
 * g_spawn_async_with_pipes() you will need to pass %G_SPAWN_DO_NOT_REAP_CHILD as flag to the spawn
 * function for the child watching to work.
 * Also note, that you must g_source_remove() any other child watchers for @pid because glib
 * supports only one watcher per child.
 **/
void
nm_utils_kill_child_async (pid_t pid, int sig, NMLogDomain log_domain,
                           const char *log_name, guint32 wait_before_kill_msec,
                           NMUtilsKillChildAsyncCb callback, void *user_data)
{
	int status = 0, errsv;
	pid_t ret;
	KillChildAsyncData *data;
	char buf_exit[KC_EXIT_TO_STRING_BUF_SIZE];

	g_return_if_fail (pid > 0);
	g_return_if_fail (log_name != NULL);

	/* let's see if the child already terminated... */
	ret = waitpid (pid, &status, WNOHANG);
	if (ret > 0) {
		nm_log_dbg (log_domain, LOG_NAME_FMT ": process %ld already terminated %s",
		            LOG_NAME_ARGS, (long) ret, _kc_exit_to_string (buf_exit, status));
		_kc_invoke_callback (pid, log_domain, log_name, callback, user_data, TRUE, status);
		return;
	} else if (ret != 0) {
		errsv = errno;
		/* ECHILD means, the process is not a child/does not exist or it has SIGCHILD blocked. */
		if (errsv != ECHILD) {
			nm_log_err (LOGD_CORE | log_domain, LOG_NAME_FMT ": unexpected error while waitpid: %s (%d)",
			            LOG_NAME_ARGS, strerror (errsv), errsv);
			_kc_invoke_callback (pid, log_domain, log_name, callback, user_data, FALSE, -1);
			return;
		}
	}

	/* send the first signal. */
	if (kill (pid, sig) != 0) {
		errsv = errno;
		/* ESRCH means, process does not exist or is already a zombie. */
		if (errsv != ESRCH) {
			nm_log_err (LOGD_CORE | log_domain, LOG_NAME_FMT ": unexpected error sending %s: %s (%d)",
			            LOG_NAME_ARGS, _kc_signal_to_string (sig), strerror (errsv), errsv);
			_kc_invoke_callback (pid, log_domain, log_name, callback, user_data, FALSE, -1);
			return;
		}

		/* let's try again with waitpid, probably there was a race... */
		ret = waitpid (pid, &status, 0);
		if (ret > 0) {
			nm_log_dbg (log_domain, LOG_NAME_FMT ": process %ld already terminated %s",
			            LOG_NAME_ARGS, (long) ret, _kc_exit_to_string (buf_exit, status));
			_kc_invoke_callback (pid, log_domain, log_name, callback, user_data, TRUE, status);
		} else {
			errsv = errno;
			nm_log_err (LOGD_CORE | log_domain, LOG_NAME_FMT ": failed due to unexpected return value %ld by waitpid (%s, %d) after sending %s",
			            LOG_NAME_ARGS, (long) ret, strerror (errsv), errsv, _kc_signal_to_string (sig));
			_kc_invoke_callback (pid, log_domain, log_name, callback, user_data, FALSE, -1);
		}
		return;
	}

	data = _kc_async_data_alloc (pid, log_domain, log_name, callback, user_data);
	data->async.wait_start_us = nm_utils_get_monotonic_timestamp_us ();

	if (sig != SIGKILL && wait_before_kill_msec > 0) {
		data->async.source_timeout_kill_id = g_timeout_add (wait_before_kill_msec, _kc_cb_timeout_grace_period, data);
		nm_log_dbg (log_domain, "%s: wait for process to terminate after sending %s (send SIGKILL in %ld milliseconds)...",
		            data->log_name,  _kc_signal_to_string (sig), (long) wait_before_kill_msec);
	} else {
		data->async.source_timeout_kill_id = 0;
		nm_log_dbg (log_domain, "%s: wait for process to terminate after sending %s...",
		            data->log_name, _kc_signal_to_string (sig));
	}

	g_child_watch_add (pid, _kc_cb_watch_child, data);
}

static inline gulong
_sleep_duration_convert_ms_to_us (guint32 sleep_duration_msec)
{
	if (sleep_duration_msec > 0) {
		guint64 x = (gint64) sleep_duration_msec * (guint64) 1000L;

		return x < G_MAXULONG ? (gulong) x : G_MAXULONG;
	}
	return G_USEC_PER_SEC / 20;
}

/* nm_utils_kill_child_sync:
 * @pid: process id to kill
 * @sig: signal to sent initially. If 0, no signal is sent. If %SIGKILL, the
 * second %SIGKILL signal is not sent after @wait_before_kill_msec milliseconds.
 * @log_domain: log debug information for this domain. Errors and warnings are logged both
 * as %LOGD_CORE and @log_domain.
 * @log_name: name of the process to kill for logging.
 * @child_status: (out) (allow-none): return the exit status of the child, if no error occured.
 * @wait_before_kill_msec: Waittime in milliseconds before sending %SIGKILL signal. Set this value
 * to zero, not to send %SIGKILL. If @sig is already %SIGKILL, this parameter has not effect.
 * @sleep_duration_msec: the synchronous function sleeps repeatedly waiting for the child to terminate.
 * Set to zero, to use the default (meaning 20 wakeups per seconds).
 *
 * Kill a child process synchronously and wait. The function first checks if the child already terminated
 * and if it did, return the exit status. Otherwise send one @sig signal. @sig  will always be
 * sent unless the child already exited. If the child does not exit within @wait_before_kill_msec milliseconds,
 * the function will send %SIGKILL and waits for the child indefinitly. If @wait_before_kill_msec is zero, no
 * %SIGKILL signal will be sent.
 *
 * In case of error, errno is preserved to contain the last reason of failure.
 **/
gboolean
nm_utils_kill_child_sync (pid_t pid, int sig, NMLogDomain log_domain, const char *log_name,
                          int *child_status, guint32 wait_before_kill_msec,
                          guint32 sleep_duration_msec)
{
	int status = 0, errsv = 0;
	pid_t ret;
	gboolean success = FALSE;
	gboolean was_waiting = FALSE, send_kill = FALSE;
	char buf_exit[KC_EXIT_TO_STRING_BUF_SIZE];
	char buf_wait[KC_WAITED_TO_STRING];
	gint64 wait_start_us;

	g_return_val_if_fail (pid > 0, FALSE);
	g_return_val_if_fail (log_name != NULL, FALSE);

	/* check if the child process already terminated... */
	ret = waitpid (pid, &status, WNOHANG);
	if (ret > 0) {
		nm_log_dbg (log_domain, LOG_NAME_FMT ": process %ld already terminated %s",
		            LOG_NAME_ARGS, (long) ret, _kc_exit_to_string (buf_exit, status));
		success = TRUE;
		goto out;
	} else if (ret != 0) {
		errsv = errno;
		/* ECHILD means, the process is not a child/does not exist or it has SIGCHILD blocked. */
		if (errsv != ECHILD) {
			nm_log_err (LOGD_CORE | log_domain, LOG_NAME_FMT ": unexpected error while waitpid: %s (%d)",
			            LOG_NAME_ARGS, strerror (errsv), errsv);
			goto out;
		}
	}

	/* send first signal @sig */
	if (kill (pid, sig) != 0) {
		errsv = errno;
		/* ESRCH means, process does not exist or is already a zombie. */
		if (errsv != ESRCH) {
			nm_log_err (LOGD_CORE | log_domain, LOG_NAME_FMT ": failed to send %s: %s (%d)",
			            LOG_NAME_ARGS, _kc_signal_to_string (sig), strerror (errsv), errsv);
		} else {
			/* let's try again with waitpid, probably there was a race... */
			ret = waitpid (pid, &status, 0);
			if (ret > 0) {
				nm_log_dbg (log_domain, LOG_NAME_FMT ": process %ld already terminated %s",
				            LOG_NAME_ARGS, (long) ret, _kc_exit_to_string (buf_exit, status));
				success = TRUE;
			} else {
				errsv = errno;
				nm_log_err (LOGD_CORE | log_domain, LOG_NAME_FMT ": failed due to unexpected return value %ld by waitpid (%s, %d) after sending %s",
				            LOG_NAME_ARGS, (long) ret, strerror (errsv), errsv, _kc_signal_to_string (sig));
			}
		}
		goto out;
	}

	wait_start_us = nm_utils_get_monotonic_timestamp_us ();

	/* wait for the process to terminated... */
	if (sig != SIGKILL) {
		gint64 wait_until, now;
		gulong sleep_time, sleep_duration_usec;
		int loop_count = 0;

		sleep_duration_usec = _sleep_duration_convert_ms_to_us (sleep_duration_msec);
		wait_until = wait_before_kill_msec <= 0 ? 0 : wait_start_us + (((gint64) wait_before_kill_msec) * 1000L);

		while (TRUE) {
			ret = waitpid (pid, &status, WNOHANG);
			if (ret > 0) {
				nm_log_dbg (log_domain, LOG_NAME_FMT ": after sending %s, process %ld exited %s%s",
				            LOG_NAME_ARGS, _kc_signal_to_string (sig), (long) ret, _kc_exit_to_string (buf_exit, status),
				            was_waiting ? _kc_waited_to_string (buf_wait, wait_start_us) : "");
				success = TRUE;
				goto out;
			}
			if (ret == -1) {
				errsv = errno;
				/* ECHILD means, the process is not a child/does not exist or it has SIGCHILD blocked. */
				if (errsv != ECHILD) {
					nm_log_err (LOGD_CORE | log_domain, LOG_NAME_FMT ": after sending %s, waitpid failed with %s (%d)%s",
					            LOG_NAME_ARGS, _kc_signal_to_string (sig), strerror (errsv), errsv,
					           was_waiting ? _kc_waited_to_string (buf_wait, wait_start_us) : "");
					goto out;
				}
			}

			if (!wait_until)
				break;

			now = nm_utils_get_monotonic_timestamp_us ();
			if (now >= wait_until)
				break;

			if (!was_waiting) {
				nm_log_dbg (log_domain, LOG_NAME_FMT ": waiting up to %ld milliseconds for process to terminate normally after sending %s...",
				            LOG_NAME_ARGS, (long) MAX (wait_before_kill_msec, 0), _kc_signal_to_string (sig));
				was_waiting = TRUE;
			}

			sleep_time = MIN (wait_until - now, sleep_duration_usec);
			if (loop_count < 20) {
				/* At the beginning we expect the process to die fast.
				 * Limit the sleep time, the limit doubles with every iteration. */
				sleep_time = MIN (sleep_time, (((guint64) 1) << loop_count) * G_USEC_PER_SEC / 2000);
				loop_count++;
			}
			g_usleep (sleep_time);
		}

		/* send SIGKILL, if called with @wait_before_kill_msec > 0 */
		if (wait_until) {
			nm_log_dbg (log_domain, LOG_NAME_FMT ": sending SIGKILL...", LOG_NAME_ARGS);

			send_kill = TRUE;
			if (kill (pid, SIGKILL) != 0) {
				errsv = errno;
				/* ESRCH means, process does not exist or is already a zombie. */
				if (errsv != ESRCH) {
					nm_log_err (LOGD_CORE | log_domain, LOG_NAME_FMT ": failed to send SIGKILL (after sending %s), %s (%d)",
								LOG_NAME_ARGS, _kc_signal_to_string (sig), strerror (errsv), errsv);
					goto out;
				}
			}
		}
	}

	if (!was_waiting) {
		nm_log_dbg (log_domain, LOG_NAME_FMT ": waiting for process to terminate after sending %s%s...",
		            LOG_NAME_ARGS, _kc_signal_to_string (sig), send_kill ? " and SIGKILL" : "");
	}

	/* block until the child terminates. */
	while ((ret = waitpid (pid, &status, 0)) <= 0) {
		errsv = errno;

		if (errsv != EINTR) {
			nm_log_err (LOGD_CORE | log_domain, LOG_NAME_FMT ": after sending %s%s, waitpid failed with %s (%d)%s",
			            LOG_NAME_ARGS, _kc_signal_to_string (sig), send_kill ? " and SIGKILL" : "", strerror (errsv), errsv,
			            _kc_waited_to_string (buf_wait, wait_start_us));
			goto out;
		}
	}

	nm_log_dbg (log_domain, LOG_NAME_FMT ": after sending %s%s, process %ld exited %s%s",
	            LOG_NAME_ARGS, _kc_signal_to_string (sig), send_kill ? " and SIGKILL" : "", (long) ret,
	            _kc_exit_to_string (buf_exit, status), _kc_waited_to_string (buf_wait, wait_start_us));
	success = TRUE;
out:
	if (child_status)
		*child_status = success ? status : -1;
	errno = success ? 0 : errsv;
	return success;
}

/* nm_utils_kill_process_sync:
 * @pid: process id to kill
 * @start_time: the start time of the process to kill (as obtained by nm_utils_get_start_time_for_pid()).
 *   This is an optional argument, to avoid (somewhat) killing the wrong process as @pid
 *   might get recycled. You can pass 0, to not provide this parameter.
 * @sig: signal to sent initially. If 0, no signal is sent. If %SIGKILL, the
 *   second %SIGKILL signal is not sent after @wait_before_kill_msec milliseconds.
 * @log_domain: log debug information for this domain. Errors and warnings are logged both
 *   as %LOGD_CORE and @log_domain.
 * @log_name: name of the process to kill for logging.
 * @wait_before_kill_msec: Waittime in milliseconds before sending %SIGKILL signal. Set this value
 *   to zero, not to send %SIGKILL. If @sig is already %SIGKILL, this parameter has no effect.
 *   If @max_wait_msec is set but less then @wait_before_kill_msec, the final %SIGKILL will also
 *   not be send.
 * @sleep_duration_msec: the synchronous function sleeps repeatedly waiting for the child to terminate.
 *   Set to zero, to use the default (meaning 20 wakeups per seconds).
 * @max_wait_msec: if 0, waits indefinitely until the process is gone (or a zombie). Otherwise, this
 *   is the maxium wait time until returning. If @max_wait_msec is non-zero but smaller then @wait_before_kill_msec,
 *   we will not send a final %SIGKILL.
 *
 * Kill a non-child process synchronously and wait. This function will not return before the
 * process with PID @pid is gone, the process is a zombie, or @max_wait_msec expires.
 **/
void
nm_utils_kill_process_sync (pid_t pid, guint64 start_time, int sig, NMLogDomain log_domain,
                            const char *log_name, guint32 wait_before_kill_msec,
                            guint32 sleep_duration_msec, guint32 max_wait_msec)
{
	int errsv;
	guint64 start_time0;
	gint64 wait_until_sigkill, now, wait_start_us, max_wait_until;
	gulong sleep_time, sleep_duration_usec;
	int loop_count = 0;
	gboolean was_waiting = FALSE;
	char buf_wait[KC_WAITED_TO_STRING];
	char p_state;

	g_return_if_fail (pid > 0);
	g_return_if_fail (log_name != NULL);

	start_time0 = nm_utils_get_start_time_for_pid (pid, &p_state, NULL);
	if (start_time0 == 0) {
		nm_log_dbg (log_domain, LOG_NAME_PROCESS_FMT ": cannot kill process %ld because it seems already gone",
		            LOG_NAME_ARGS, (long int) pid);
		return;
	}
	if (start_time != 0 && start_time != start_time0) {
		nm_log_dbg (log_domain, LOG_NAME_PROCESS_FMT ": don't kill process %ld because the start_time is unexpectedly %lu instead of %ld",
		            LOG_NAME_ARGS, (long int) pid, (long unsigned) start_time0, (long unsigned) start_time);
		return;
	}

	switch (p_state) {
	case 'Z':
	case 'x':
	case 'X':
		nm_log_dbg (log_domain, LOG_NAME_PROCESS_FMT ": cannot kill process %ld because it is already a zombie (%c)",
		            LOG_NAME_ARGS, (long int) pid, p_state);
		return;
	default:
		break;
	}

	if (kill (pid, sig) != 0) {
		errsv = errno;
		/* ESRCH means, process does not exist or is already a zombie. */
		if (errsv == ESRCH) {
			nm_log_dbg (log_domain, LOG_NAME_PROCESS_FMT ": failed to send %s because process seems gone",
			            LOG_NAME_ARGS, _kc_signal_to_string (sig));
		} else {
			nm_log_warn (LOGD_CORE | log_domain, LOG_NAME_PROCESS_FMT ": failed to send %s: %s (%d)",
			             LOG_NAME_ARGS, _kc_signal_to_string (sig), strerror (errsv), errsv);
		}
		return;
	}

	/* wait for the process to terminate... */

	wait_start_us = nm_utils_get_monotonic_timestamp_us ();

	sleep_duration_usec = _sleep_duration_convert_ms_to_us (sleep_duration_msec);
	if (sig != SIGKILL && wait_before_kill_msec)
		wait_until_sigkill = wait_start_us + (((gint64) wait_before_kill_msec) * 1000L);
	else
		wait_until_sigkill = 0;
	if (max_wait_msec > 0) {
		max_wait_until = wait_start_us + (((gint64) max_wait_msec) * 1000L);
		if (wait_until_sigkill > 0 && wait_until_sigkill > max_wait_msec)
			wait_until_sigkill = 0;
	} else
		max_wait_until = 0;

	while (TRUE) {
		start_time = nm_utils_get_start_time_for_pid (pid, &p_state, NULL);

		if (start_time != start_time0) {
			nm_log_dbg (log_domain, LOG_NAME_PROCESS_FMT ": process is gone after sending signal %s%s",
			            LOG_NAME_ARGS, _kc_signal_to_string (sig),
			            was_waiting ? _kc_waited_to_string (buf_wait, wait_start_us) : "");
			return;
		}
		switch (p_state) {
		case 'Z':
		case 'x':
		case 'X':
			nm_log_dbg (log_domain, LOG_NAME_PROCESS_FMT ": process is a zombie (%c) after sending signal %s%s",
			            LOG_NAME_ARGS, p_state, _kc_signal_to_string (sig),
			            was_waiting ? _kc_waited_to_string (buf_wait, wait_start_us) : "");
			return;
		default:
			break;
		}

		if (kill (pid, 0) != 0) {
			errsv = errno;
			/* ESRCH means, process does not exist or is already a zombie. */
			if (errsv == ESRCH) {
				nm_log_dbg (log_domain, LOG_NAME_PROCESS_FMT ": process is gone or a zombie after sending signal %s%s",
				            LOG_NAME_ARGS, _kc_signal_to_string (sig),
				            was_waiting ? _kc_waited_to_string (buf_wait, wait_start_us) : "");
			} else {
				nm_log_warn (LOGD_CORE | log_domain, LOG_NAME_PROCESS_FMT ": failed to kill(%ld, 0): %s (%d)%s",
				             LOG_NAME_ARGS, (long int) pid, strerror (errsv), errsv,
				             was_waiting ? _kc_waited_to_string (buf_wait, wait_start_us) : "");
			}
			return;
		}

		sleep_time = sleep_duration_usec;
		now = nm_utils_get_monotonic_timestamp_us ();

		if (   max_wait_until != 0
		    && now >= max_wait_until) {
			if (wait_until_sigkill != 0) {
				/* wait_before_kill_msec is not larger then max_wait_until but we did not yet send
				 * SIGKILL. Although we already reached our timeout, we don't want to skip sending
				 * the signal. Even if we don't wait for the process to disappear. */
				nm_log_dbg (log_domain, LOG_NAME_PROCESS_FMT ": sending SIGKILL", LOG_NAME_ARGS);
				kill (pid, SIGKILL);
			}
			nm_log_warn (log_domain, LOG_NAME_PROCESS_FMT ": timeout %u msec waiting for process to disappear (after sending %s)%s",
			             LOG_NAME_ARGS, (unsigned) max_wait_until, _kc_signal_to_string (sig),
			             was_waiting ? _kc_waited_to_string (buf_wait, wait_start_us) : "");
			return;
		}

		if (wait_until_sigkill != 0) {
			if (now >= wait_until_sigkill) {
				/* Still not dead. SIGKILL now... */
				nm_log_dbg (log_domain, LOG_NAME_PROCESS_FMT ": sending SIGKILL", LOG_NAME_ARGS);
				if (kill (pid, SIGKILL) != 0) {
					errsv = errno;
					/* ESRCH means, process does not exist or is already a zombie. */
					if (errsv != ESRCH) {
						nm_log_dbg (log_domain, LOG_NAME_PROCESS_FMT ": process is gone or a zombie%s",
						            LOG_NAME_ARGS, _kc_waited_to_string (buf_wait, wait_start_us));
					} else {
						nm_log_warn (LOGD_CORE | log_domain, LOG_NAME_PROCESS_FMT ": failed to send SIGKILL (after sending %s), %s (%d)%s",
						             LOG_NAME_ARGS, _kc_signal_to_string (sig), strerror (errsv), errsv,
						             _kc_waited_to_string (buf_wait, wait_start_us));
					}
					return;
				}
				sig = SIGKILL;
				wait_until_sigkill = 0;
				loop_count = 0; /* reset the loop_count. Now we really expect the process to die quickly. */
			} else
				sleep_time = MIN (wait_until_sigkill - now, sleep_duration_usec);
		}

		if (!was_waiting) {
			if (wait_until_sigkill != 0) {
				nm_log_dbg (log_domain, LOG_NAME_PROCESS_FMT ": waiting up to %ld milliseconds for process to disappear before sending KILL signal after sending %s...",
				            LOG_NAME_ARGS, (long) wait_before_kill_msec, _kc_signal_to_string (sig));
			} else if (max_wait_until != 0) {
				nm_log_dbg (log_domain, LOG_NAME_PROCESS_FMT ": waiting up to %ld milliseconds for process to disappear after sending %s...",
				            LOG_NAME_ARGS, (long) max_wait_msec, _kc_signal_to_string (sig));
			} else {
				nm_log_dbg (log_domain, LOG_NAME_PROCESS_FMT ": waiting for process to disappear after sending %s...",
				            LOG_NAME_ARGS, _kc_signal_to_string (sig));
			}
			was_waiting = TRUE;
		}

		if (loop_count < 20) {
			/* At the beginning we expect the process to die fast.
			 * Limit the sleep time, the limit doubles with every iteration. */
			sleep_time = MIN (sleep_time, (((guint64) 1) << loop_count) * G_USEC_PER_SEC / 2000);
			loop_count++;
		}
		g_usleep (sleep_time);
	}
}
#undef LOG_NAME_FMT
#undef LOG_NAME_PROCESS_FMT
#undef LOG_NAME_ARGS

const char *const NM_PATHS_DEFAULT[] = {
	PREFIX "/sbin/",
	PREFIX "/bin/",
	"/usr/local/sbin/",
	"/sbin/",
	"/usr/sbin/",
	"/usr/local/bin/",
	"/bin/",
	"/usr/bin/",
	NULL,
};

const char *
nm_utils_find_helper(const char *progname, const char *try_first, GError **error)
{
	return nm_utils_file_search_in_paths (progname, try_first, NM_PATHS_DEFAULT, G_FILE_TEST_IS_EXECUTABLE, NULL, NULL, error);
}

/*****************************************************************************/

/**
 * nm_utils_read_link_absolute:
 * @link_file: file name of the symbolic link
 * @error: error reason in case of failure
 *
 * Uses to g_file_read_link()/readlink() to read the symlink
 * and returns the result as absolute path.
 **/
char *
nm_utils_read_link_absolute (const char *link_file, GError **error)
{
	char *ln, *dirname, *ln_abs;

	ln = g_file_read_link (link_file, error);
	if (!ln)
		return NULL;
	if (g_path_is_absolute (ln))
		return ln;

	dirname = g_path_get_dirname (link_file);
	if (!g_path_is_absolute (link_file)) {
		gs_free char *dirname_rel = dirname;
		gs_free char *current_dir = g_get_current_dir ();

		dirname = g_build_filename (current_dir, dirname_rel, NULL);
	}
	ln_abs = g_build_filename (dirname, ln, NULL);
	g_free (dirname);
	g_free (ln);
	return ln_abs;
}

/*****************************************************************************/

#define MAC_TAG "mac:"
#define INTERFACE_NAME_TAG "interface-name:"
#define DEVICE_TYPE_TAG "type:"
#define SUBCHAN_TAG "s390-subchannels:"
#define EXCEPT_TAG "except:"
#define MATCH_TAG_CONFIG_NM_VERSION             "nm-version:"
#define MATCH_TAG_CONFIG_NM_VERSION_MIN         "nm-version-min:"
#define MATCH_TAG_CONFIG_NM_VERSION_MAX         "nm-version-max:"
#define MATCH_TAG_CONFIG_ENV                    "env:"

typedef struct {
	const char *interface_name;
	const char *device_type;
	struct {
		const char *value;
		gboolean is_parsed;
		guint len;
		guint8 bin[NM_UTILS_HWADDR_LEN_MAX];
	} hwaddr;
	struct {
		const char *value;
		gboolean is_parsed;
		guint32 a;
		guint32 b;
		guint32 c;
	} s390_subchannels;
} MatchDeviceData;

static gboolean
match_device_s390_subchannels_parse (const char *s390_subchannels, guint32 *out_a, guint32 *out_b, guint32 *out_c)
{
	const int BUFSIZE = 30;
	char buf[BUFSIZE + 1];
	guint i = 0;
	char *pa = NULL, *pb = NULL, *pc = NULL;
	gint64 a, b, c;

	nm_assert (s390_subchannels);
	nm_assert (out_a);
	nm_assert (out_b);
	nm_assert (out_c);

	if (!g_ascii_isxdigit (s390_subchannels[0]))
		return FALSE;

	/* Get the first channel */
	for (i = 0; s390_subchannels[i]; i++) {
		char ch = s390_subchannels[i];

		if (!g_ascii_isxdigit (ch) && ch != '.') {
			if (ch == ',') {
				/* FIXME: currently we consider the first channel and ignore
				 * everything after the first ',' separator. Maybe we should
				 * validate all present channels? */
				break;
			}
			return FALSE;  /* Invalid chars */
		}
		if (i >= BUFSIZE)
			return FALSE;  /* Too long to be a subchannel */
		buf[i] = ch;
	}
	buf[i] = '\0';

	/* and grab each of its elements, there should be 3 */
	pa = &buf[0];
	pb = strchr (pa, '.');
	if (pb)
		pc = strchr (pb + 1, '.');
	if (!pb || !pc)
		return FALSE;
	*pb++ = '\0';
	*pc++ = '\0';

	a = _nm_utils_ascii_str_to_int64 (pa, 16, 0, G_MAXUINT32, -1);
	if (a == -1)
		return FALSE;
	b = _nm_utils_ascii_str_to_int64 (pb, 16, 0, G_MAXUINT32, -1);
	if (b == -1)
		return FALSE;
	c = _nm_utils_ascii_str_to_int64 (pc, 16, 0, G_MAXUINT32, -1);
	if (c == -1)
		return FALSE;

	*out_a = (guint32) a;
	*out_b = (guint32) b;
	*out_c = (guint32) c;
	return TRUE;
}

static gboolean
match_data_s390_subchannels_eval (const char *spec_str,
                                  MatchDeviceData *match_data)
{
	guint32 a, b, c;

	if (G_UNLIKELY (!match_data->s390_subchannels.is_parsed)) {
		match_data->s390_subchannels.is_parsed = TRUE;

		if (   !match_data->s390_subchannels.value
		    || !match_device_s390_subchannels_parse (match_data->s390_subchannels.value,
		                                             &match_data->s390_subchannels.a,
		                                             &match_data->s390_subchannels.b,
		                                             &match_data->s390_subchannels.c)) {
			match_data->s390_subchannels.value = NULL;
			return FALSE;
		}
	} else if (!match_data->s390_subchannels.value)
		return FALSE;

	if (!match_device_s390_subchannels_parse (spec_str, &a, &b, &c))
		return FALSE;
	return    match_data->s390_subchannels.a == a
	       && match_data->s390_subchannels.b == b
	       && match_data->s390_subchannels.c == c;
}

static gboolean
match_device_hwaddr_eval (const char *spec_str,
                          MatchDeviceData *match_data)
{
	if (G_UNLIKELY (!match_data->hwaddr.is_parsed)) {
		match_data->hwaddr.is_parsed = TRUE;

		if (match_data->hwaddr.value) {
			gsize l;

			if (!_nm_utils_hwaddr_aton (match_data->hwaddr.value, match_data->hwaddr.bin, sizeof (match_data->hwaddr.bin), &l))
				g_return_val_if_reached (FALSE);
			match_data->hwaddr.len = l;
		} else
			return FALSE;
	} else if (!match_data->hwaddr.len)
		return FALSE;

	return nm_utils_hwaddr_matches (spec_str, -1, match_data->hwaddr.bin, match_data->hwaddr.len);
}

#define _MATCH_CHECK(spec_str, tag) \
	({ \
		gboolean _has = FALSE; \
		\
		if (!g_ascii_strncasecmp (spec_str, (""tag""), NM_STRLEN (tag))) { \
			spec_str += NM_STRLEN (tag); \
			_has = TRUE; \
		} \
		_has; \
	})

static const char *
match_except (const char *spec_str, gboolean *out_except)
{
	if (_MATCH_CHECK (spec_str, EXCEPT_TAG))
		*out_except = TRUE;
	else
		*out_except = FALSE;
	return spec_str;
}

static gboolean
match_device_eval (const char *spec_str,
                   gboolean allow_fuzzy,
                   MatchDeviceData *match_data)
{
	if (spec_str[0] == '*' && spec_str[1] == '\0')
		return TRUE;

	if (_MATCH_CHECK (spec_str, DEVICE_TYPE_TAG)) {
		return    match_data->device_type
		       && nm_streq (spec_str, match_data->device_type);
	}

	if (_MATCH_CHECK (spec_str, MAC_TAG))
		return match_device_hwaddr_eval (spec_str, match_data);

	if (_MATCH_CHECK (spec_str, INTERFACE_NAME_TAG)) {
		gboolean use_pattern = FALSE;

		if (spec_str[0] == '=')
			spec_str += 1;
		else {
			if (spec_str[0] == '~')
				spec_str += 1;
			use_pattern = TRUE;
		}

		if (match_data->interface_name) {
			if (nm_streq (spec_str, match_data->interface_name))
				return TRUE;
			if (use_pattern && g_pattern_match_simple (spec_str, match_data->interface_name))
				return TRUE;
		}
		return FALSE;
	}

	if (_MATCH_CHECK (spec_str, SUBCHAN_TAG))
		return match_data_s390_subchannels_eval (spec_str, match_data);

	if (allow_fuzzy) {
		if (match_device_hwaddr_eval (spec_str, match_data))
			return TRUE;
		if (   match_data->interface_name
		    && nm_streq (spec_str, match_data->interface_name))
			return TRUE;
	}

	return FALSE;
}

NMMatchSpecMatchType
nm_match_spec_device (const GSList *specs,
                      const char *interface_name,
                      const char *device_type,
                      const char *hwaddr,
                      const char *s390_subchannels)
{
	const GSList *iter;
	NMMatchSpecMatchType match;
	const char *spec_str;
	gboolean except;
	MatchDeviceData match_data = {
	    .interface_name = interface_name,
	    .device_type = nm_str_not_empty (device_type),
	    .hwaddr = {
	        .value = hwaddr,
	    },
	    .s390_subchannels = {
	        .value = s390_subchannels,
	    },
	};

	nm_assert (!hwaddr || nm_utils_hwaddr_valid (hwaddr, -1));

	if (!specs)
		return NM_MATCH_SPEC_NO_MATCH;

	match = NM_MATCH_SPEC_NO_MATCH;

	/* pre-search for "*" */
	for (iter = specs; iter; iter = iter->next) {
		spec_str = iter->data;

		if (spec_str && spec_str[0] == '*' && spec_str[1] == '\0') {
			match = NM_MATCH_SPEC_MATCH;
			break;
		}
	}

	for (iter = specs; iter; iter = iter->next) {
		spec_str = iter->data;

		if (!spec_str || !*spec_str)
			continue;

		spec_str = match_except (spec_str, &except);

		if (   !except
		    && match == NM_MATCH_SPEC_MATCH) {
			/* we have no "except-match" but already match. No need to evaluate
			 * the match, we cannot match stronger. */
			continue;
		}

		if (!match_device_eval (spec_str,
		                        !except,
		                        &match_data))
			continue;

		if (except)
			return NM_MATCH_SPEC_NEG_MATCH;
		match = NM_MATCH_SPEC_MATCH;
	}

	return match;
}

static gboolean
match_config_eval (const char *str, const char *tag, guint cur_nm_version)
{
	gs_free char *s_ver = NULL;
	gs_strfreev char **s_ver_tokens = NULL;
	gint v_maj = -1, v_min = -1, v_mic = -1;
	guint c_maj = -1, c_min = -1, c_mic = -1;
	guint n_tokens;

	s_ver = g_strdup (str);
	g_strstrip (s_ver);

	/* Let's be strict with the accepted format here. No funny stuff!! */

	if (s_ver[strspn (s_ver, ".0123456789")] != '\0')
		return FALSE;

	s_ver_tokens = g_strsplit (s_ver, ".", -1);
	n_tokens = g_strv_length (s_ver_tokens);
	if (n_tokens == 0 || n_tokens > 3)
		return FALSE;

	v_maj = _nm_utils_ascii_str_to_int64 (s_ver_tokens[0], 10, 0, 0xFFFF, -1);
	if (v_maj < 0)
		return FALSE;
	if (n_tokens >= 2) {
		v_min = _nm_utils_ascii_str_to_int64 (s_ver_tokens[1], 10, 0, 0xFF, -1);
		if (v_min < 0)
			return FALSE;
	}
	if (n_tokens >= 3) {
		v_mic = _nm_utils_ascii_str_to_int64 (s_ver_tokens[2], 10, 0, 0xFF, -1);
		if (v_mic < 0)
			return FALSE;
	}

	nm_decode_version (cur_nm_version, &c_maj, &c_min, &c_mic);

#define CHECK_AND_RETURN_FALSE(cur, val, tag, is_last_digit) \
	G_STMT_START { \
		if (!strcmp (tag, MATCH_TAG_CONFIG_NM_VERSION_MIN)) { \
			if (cur < val) \
				return FALSE; \
		} else if (!strcmp (tag, MATCH_TAG_CONFIG_NM_VERSION_MAX)) { \
			if (cur > val) \
				return FALSE; \
		} else { \
			if (cur != val) \
				return FALSE; \
		} \
		if (!(is_last_digit)) { \
			if (cur != val) \
				return FALSE; \
		} \
	} G_STMT_END
	if (v_mic >= 0)
		CHECK_AND_RETURN_FALSE (c_mic, v_mic, tag, TRUE);
	if (v_min >= 0)
		CHECK_AND_RETURN_FALSE (c_min, v_min, tag, v_mic < 0);
	CHECK_AND_RETURN_FALSE (c_maj, v_maj, tag, v_min < 0);
	return TRUE;
}

NMMatchSpecMatchType
nm_match_spec_config (const GSList *specs, guint cur_nm_version, const char *env)
{
	const GSList *iter;
	NMMatchSpecMatchType match = NM_MATCH_SPEC_NO_MATCH;

	if (!specs)
		return NM_MATCH_SPEC_NO_MATCH;

	for (iter = specs; iter; iter = g_slist_next (iter)) {
		const char *spec_str = iter->data;
		gboolean except;
		gboolean v_match;

		if (!spec_str || !*spec_str)
			continue;

		spec_str = match_except (spec_str, &except);

		if (_MATCH_CHECK (spec_str, MATCH_TAG_CONFIG_NM_VERSION))
			v_match = match_config_eval (spec_str, MATCH_TAG_CONFIG_NM_VERSION, cur_nm_version);
		else if (_MATCH_CHECK (spec_str, MATCH_TAG_CONFIG_NM_VERSION_MIN))
			v_match = match_config_eval (spec_str, MATCH_TAG_CONFIG_NM_VERSION_MIN, cur_nm_version);
		else if (_MATCH_CHECK (spec_str, MATCH_TAG_CONFIG_NM_VERSION_MAX))
			v_match = match_config_eval (spec_str, MATCH_TAG_CONFIG_NM_VERSION_MAX, cur_nm_version);
		else if (_MATCH_CHECK (spec_str, MATCH_TAG_CONFIG_ENV))
			v_match = env && env[0] && !strcmp (spec_str, env);
		else
			continue;

		if (v_match) {
			if (except)
				return NM_MATCH_SPEC_NEG_MATCH;
			match = NM_MATCH_SPEC_MATCH;
		}
	}
	return match;
}

#undef _MATCH_CHECK

/**
 * nm_match_spec_split:
 * @value: the string of device specs
 *
 * Splits the specs from the string and returns them as individual
 * entires in a #GSList.
 *
 * It does not validate any specs, it basically just does a special
 * strsplit with ',' or ';' as separators and supporting '\\' as
 * escape character.
 *
 * Leading and trailing spaces of each entry are removed. But the user
 * can preserve them by specifying "\\s has 2 leading" or "has 2 trailing \\s".
 *
 * Specs can have a qualifier like "interface-name:". We still don't strip
 * any whitespace after the colon, so "interface-name: X" matches an interface
 * named " X".
 *
 * Returns: (transfer full): the list of device specs.
 */
GSList *
nm_match_spec_split (const char *value)
{
	char *string_value, *p, *q0, *q;
	GSList *pieces = NULL;
	int trailing_ws;

	if (!value || !*value)
		return NULL;

	/* Copied from glibs g_key_file_parse_value_as_string() function
	 * and adjusted. */

	string_value = g_new (gchar, strlen (value) + 1);

	p = (gchar *) value;

	/* skip over leading whitespace */
	while (g_ascii_isspace (*p))
		p++;

	q0 = q = string_value;
	trailing_ws = 0;
	while (*p) {
		if (*p == '\\') {
			p++;

			switch (*p) {
			case 's':
				*q = ' ';
				break;
			case 'n':
				*q = '\n';
				break;
			case 't':
				*q = '\t';
				break;
			case 'r':
				*q = '\r';
				break;
			case '\\':
				*q = '\\';
				break;
			case '\0':
				break;
			default:
				if (NM_IN_SET (*p, ',', ';'))
					*q = *p;
				else {
					*q++ = '\\';
					*q = *p;
				}
				break;
			}
			if (*p == '\0')
				break;
			p++;
			trailing_ws = 0;
		} else {
			*q = *p;
			if (*p == '\0')
				break;
			if (g_ascii_isspace (*p)) {
				trailing_ws++;
				p++;
			} else if (NM_IN_SET (*p, ',', ';')) {
				if (q0 < q - trailing_ws)
					pieces = g_slist_prepend (pieces, g_strndup (q0, (q - q0) - trailing_ws));
				q0 = q + 1;
				p++;
				trailing_ws = 0;
				while (g_ascii_isspace (*p))
					p++;
			} else
				p++;
		}
		q++;
	}

	*q = '\0';
	if (q0 < q - trailing_ws)
		pieces = g_slist_prepend (pieces, g_strndup (q0, (q - q0) - trailing_ws));
	g_free (string_value);
	return g_slist_reverse (pieces);
}

/**
 * nm_match_spec_join:
 * @specs: the device specs to join
 *
 * This is based on g_key_file_parse_string_as_value(), analog to
 * nm_match_spec_split() which is based on g_key_file_parse_value_as_string().
 *
 * Returns: (transfer full): a joined list of device specs that can be
 *   split again with nm_match_spec_split(). Note that
 *   nm_match_spec_split (nm_match_spec_join (specs)) yields the original
 *   result (which is not true the other way around because there are multiple
 *   ways to encode the same joined specs string).
 */
char *
nm_match_spec_join (GSList *specs)
{
	const char *p;
	GString *str;

	str = g_string_new ("");

	for (; specs; specs = specs->next) {
		p = specs->data;

		if (!p || !*p)
			continue;

		if (str->len > 0)
			g_string_append_c (str, ',');

		/* escape leading whitespace */
		switch (*p) {
		case ' ':
			g_string_append (str, "\\s");
			p++;
			break;
		case '\t':
			g_string_append (str, "\\t");
			p++;
			break;
		}

		for (; *p; p++) {
			switch (*p) {
			case '\n':
				g_string_append (str, "\\n");
				break;
			case '\r':
				g_string_append (str, "\\r");
				break;
			case '\\':
				g_string_append (str, "\\\\");
				break;
			case ',':
				g_string_append (str, "\\,");
				break;
			case ';':
				g_string_append (str, "\\;");
				break;
			default:
				g_string_append_c (str, *p);
				break;
			}
		}

		/* escape trailing whitespaces */
		switch (str->str[str->len - 1]) {
		case ' ':
			g_string_overwrite (str, str->len - 1, "\\s");
			break;
		case '\t':
			g_string_overwrite (str, str->len - 1, "\\t");
			break;
		}
	}

	return g_string_free (str, FALSE);
}

/*****************************************************************************/

char _nm_utils_to_string_buffer[];

void
nm_utils_to_string_buffer_init (char **buf, gsize *len)
{
	if (!*buf) {
		*buf = _nm_utils_to_string_buffer;
		*len = sizeof (_nm_utils_to_string_buffer);
	}
}

gboolean
nm_utils_to_string_buffer_init_null (gconstpointer obj, char **buf, gsize *len)
{
	nm_utils_to_string_buffer_init (buf, len);
	if (!obj) {
		g_strlcpy (*buf, "(null)", *len);
		return FALSE;
	}
	return TRUE;
}

const char *
nm_utils_flags2str (const NMUtilsFlags2StrDesc *descs,
                    gsize n_descs,
                    unsigned flags,
                    char *buf,
                    gsize len)
{
	gsize i;
	char *p;

#if NM_MORE_ASSERTS > 10
	nm_assert (descs);
	nm_assert (n_descs > 0);
	for (i = 0; i < n_descs; i++) {
		gsize j;

		nm_assert (descs[i].flag && nm_utils_is_power_of_two (descs[i].flag));
		nm_assert (descs[i].name && descs[i].name[0]);
		for (j = 0; j < i; j++)
			nm_assert (descs[j].flag != descs[i].flag);
	}
#endif

	nm_utils_to_string_buffer_init (&buf, &len);

	if (!len)
		return buf;

	buf[0] = '\0';
	if (!flags) {
		return buf;
	}

	p = buf;
	for (i = 0; flags && i < n_descs; i++) {
		if (NM_FLAGS_HAS (flags, descs[i].flag)) {
			flags &= ~descs[i].flag;

			if (buf[0] != '\0')
				nm_utils_strbuf_append_c (&p, &len, ',');
			nm_utils_strbuf_append_str (&p, &len, descs[i].name);
		}
	}
	if (flags) {
		if (buf[0] != '\0')
			nm_utils_strbuf_append_c (&p, &len, ',');
		nm_utils_strbuf_append (&p, &len, "0x%x", flags);
	}
	return buf;
};

/*****************************************************************************/

char *
nm_utils_new_vlan_name (const char *parent_iface, guint32 vlan_id)
{
	guint id_len;
	gsize parent_len;
	char *ifname;

	g_return_val_if_fail (parent_iface && *parent_iface, NULL);

	if (vlan_id < 10)
		id_len = 2;
	else if (vlan_id < 100)
		id_len = 3;
	else if (vlan_id < 1000)
		id_len = 4;
	else {
		g_return_val_if_fail (vlan_id < 4095, NULL);
		id_len = 5;
	}

	ifname = g_new (char, IFNAMSIZ);

	parent_len = strlen (parent_iface);
	parent_len = MIN (parent_len, IFNAMSIZ - 1 - id_len);
	memcpy (ifname, parent_iface, parent_len);
	g_snprintf (&ifname[parent_len], IFNAMSIZ - parent_len, ".%u", vlan_id);

	return ifname;
}

/* nm_utils_new_infiniband_name:
 * @name: the output-buffer where the value will be written. Must be
 *   not %NULL and point to a string buffer of at least IFNAMSIZ bytes.
 * @parent_name: the parent interface name
 * @p_key: the partition key.
 *
 * Returns: the infiniband name will be written to @name and @name
 *   is returned.
 */
const char *
nm_utils_new_infiniband_name (char *name, const char *parent_name, int p_key)
{
	g_return_val_if_fail (name, NULL);
	g_return_val_if_fail (parent_name && parent_name[0], NULL);
	g_return_val_if_fail (strlen (parent_name) < IFNAMSIZ, NULL);

	/* technically, p_key of 0x0000 and 0x8000 is not allowed either. But we don't
	 * want to assert against that in nm_utils_new_infiniband_name(). So be more
	 * resilient here, and accept those. */
	g_return_val_if_fail (p_key >= 0 && p_key <= 0xffff, NULL);

	/* If parent+suffix is too long, kernel would just truncate
	 * the name. We do the same. See ipoib_vlan_add().  */
	g_snprintf (name, IFNAMSIZ, "%s.%04x", parent_name, p_key);
	return name;
}

/**
 * nm_utils_read_resolv_conf_nameservers():
 * @rc_contents: contents of a resolv.conf; or %NULL to read /etc/resolv.conf
 *
 * Reads all nameservers out of @rc_contents or /etc/resolv.conf and returns
 * them.
 *
 * Returns: a #GPtrArray of 'char *' elements of each nameserver line from
 * @contents or resolv.conf
 */
GPtrArray *
nm_utils_read_resolv_conf_nameservers (const char *rc_contents)
{
	GPtrArray *nameservers = NULL;
	char *contents = NULL;
	char **lines, **iter;
	char *p;

	if (rc_contents)
		contents = g_strdup (rc_contents);
	else {
		if (!g_file_get_contents (_PATH_RESCONF, &contents, NULL, NULL))
			return NULL;
	}

	nameservers = g_ptr_array_new_full (3, g_free);

	lines = g_strsplit_set (contents, "\r\n", -1);
	for (iter = lines; *iter; iter++) {
		if (!g_str_has_prefix (*iter, "nameserver"))
			continue;
		p = *iter + strlen ("nameserver");
		if (!g_ascii_isspace (*p++))
			continue;
		/* Skip intermediate whitespace */
		while (g_ascii_isspace (*p))
			p++;
		g_strchomp (p);

		g_ptr_array_add (nameservers, g_strdup (p));
	}
	g_strfreev (lines);
	g_free (contents);

	return nameservers;
}

/**
 * nm_utils_read_resolv_conf_dns_options():
 * @rc_contents: contents of a resolv.conf; or %NULL to read /etc/resolv.conf
 *
 * Reads all dns options out of @rc_contents or /etc/resolv.conf and returns
 * them.
 *
 * Returns: a #GPtrArray of 'char *' elements of each option
 */
GPtrArray *
nm_utils_read_resolv_conf_dns_options (const char *rc_contents)
{
	GPtrArray *options = NULL;
	char *contents = NULL;
	char **lines, **line_iter;
	char **tokens, **token_iter;
	char *p;

	if (rc_contents)
		contents = g_strdup (rc_contents);
	else {
		if (!g_file_get_contents (_PATH_RESCONF, &contents, NULL, NULL))
			return NULL;
	}

	options = g_ptr_array_new_full (3, g_free);

	lines = g_strsplit_set (contents, "\r\n", -1);
	for (line_iter = lines; *line_iter; line_iter++) {
		if (!g_str_has_prefix (*line_iter, "options"))
			continue;
		p = *line_iter + strlen ("options");
		if (!g_ascii_isspace (*p++))
			continue;

		tokens = g_strsplit (p, " ", 0);
		for (token_iter = tokens; token_iter && *token_iter; token_iter++) {
			g_strstrip (*token_iter);
			if (!*token_iter[0])
				continue;
			g_ptr_array_add (options, g_strdup (*token_iter));
		}
		g_strfreev (tokens);
	}
	g_strfreev (lines);
	g_free (contents);

	return options;
}

int
nm_utils_cmp_connection_by_autoconnect_priority (NMConnection **a, NMConnection **b)
{
	NMSettingConnection *a_s_con, *b_s_con;
	gboolean a_ac, b_ac;
	gint a_ap, b_ap;

	a_s_con = nm_connection_get_setting_connection (*a);
	b_s_con = nm_connection_get_setting_connection (*b);

	a_ac = !!nm_setting_connection_get_autoconnect (a_s_con);
	b_ac = !!nm_setting_connection_get_autoconnect (b_s_con);
	if (a_ac != b_ac)
		return ((int) b_ac) - ((int) a_ac);
	if (!a_ac)
		return 0;

	a_ap = nm_setting_connection_get_autoconnect_priority (a_s_con);
	b_ap = nm_setting_connection_get_autoconnect_priority (b_s_con);
	if (a_ap != b_ap)
		return (a_ap > b_ap) ? -1 : 1;

	return 0;
}

/*****************************************************************************/

static gint64 monotonic_timestamp_offset_sec;
static int monotonic_timestamp_clock_mode = 0;

static void
monotonic_timestamp_get (struct timespec *tp)
{
	int clock_mode = 0;
	int err = 0;

	switch (monotonic_timestamp_clock_mode) {
	case 0:
		/* the clock is not yet initialized (first run) */
		err = clock_gettime (CLOCK_BOOTTIME, tp);
		if (err == -1 && errno == EINVAL) {
			clock_mode = 2;
			err = clock_gettime (CLOCK_MONOTONIC, tp);
		} else
			clock_mode = 1;
		break;
	case 1:
		/* default, return CLOCK_BOOTTIME */
		err = clock_gettime (CLOCK_BOOTTIME, tp);
		break;
	case 2:
		/* fallback, return CLOCK_MONOTONIC. Kernels prior to 2.6.39
		 * don't support CLOCK_BOOTTIME. */
		err = clock_gettime (CLOCK_MONOTONIC, tp);
		break;
	}

	g_assert (err == 0); (void)err;
	g_assert (tp->tv_nsec >= 0 && tp->tv_nsec < NM_UTILS_NS_PER_SECOND);

	if (G_LIKELY (clock_mode == 0))
		return;

	/* Calculate an offset for the time stamp.
	 *
	 * We always want positive values, because then we can initialize
	 * a timestamp with 0 and be sure, that it will be less then any
	 * value nm_utils_get_monotonic_timestamp_*() might return.
	 * For this to be true also for nm_utils_get_monotonic_timestamp_s() at
	 * early boot, we have to shift the timestamp to start counting at
	 * least from 1 second onward.
	 *
	 * Another advantage of shifting is, that this way we make use of the whole 31 bit
	 * range of signed int, before the time stamp for nm_utils_get_monotonic_timestamp_s()
	 * wraps (~68 years).
	 **/
	monotonic_timestamp_offset_sec = (- ((gint64) tp->tv_sec)) + 1;
	monotonic_timestamp_clock_mode = clock_mode;

	if (nm_logging_enabled (LOGL_DEBUG, LOGD_CORE)) {
		time_t now = time (NULL);
		struct tm tm;
		char s[255];

		strftime (s, sizeof (s), "%Y-%m-%d %H:%M:%S", localtime_r (&now, &tm));
		nm_log_dbg (LOGD_CORE, "monotonic timestamp started counting 1.%09ld seconds ago with "
		                       "an offset of %lld.0 seconds to %s (local time is %s)",
		                       tp->tv_nsec, (long long) -monotonic_timestamp_offset_sec,
		                       clock_mode == 1 ? "CLOCK_BOOTTIME" : "CLOCK_MONOTONIC", s);
	}
}

/**
 * nm_utils_get_monotonic_timestamp_ns:
 *
 * Returns: a monotonically increasing time stamp in nanoseconds,
 * starting at an unspecified offset. See clock_gettime(), %CLOCK_BOOTTIME.
 *
 * The returned value will start counting at an undefined point
 * in the past and will always be positive.
 *
 * All the nm_utils_get_monotonic_timestamp_*s functions return the same
 * timestamp but in different scales (nsec, usec, msec, sec).
 **/
gint64
nm_utils_get_monotonic_timestamp_ns (void)
{
	struct timespec tp = { 0 };

	monotonic_timestamp_get (&tp);

	/* Although the result will always be positive, we return a signed
	 * integer, which makes it easier to calculate time differences (when
	 * you want to subtract signed values).
	 **/
	return (((gint64) tp.tv_sec) + monotonic_timestamp_offset_sec) * NM_UTILS_NS_PER_SECOND +
	       tp.tv_nsec;
}

/**
 * nm_utils_get_monotonic_timestamp_us:
 *
 * Returns: a monotonically increasing time stamp in microseconds,
 * starting at an unspecified offset. See clock_gettime(), %CLOCK_BOOTTIME.
 *
 * The returned value will start counting at an undefined point
 * in the past and will always be positive.
 *
 * All the nm_utils_get_monotonic_timestamp_*s functions return the same
 * timestamp but in different scales (nsec, usec, msec, sec).
 **/
gint64
nm_utils_get_monotonic_timestamp_us (void)
{
	struct timespec tp = { 0 };

	monotonic_timestamp_get (&tp);

	/* Although the result will always be positive, we return a signed
	 * integer, which makes it easier to calculate time differences (when
	 * you want to subtract signed values).
	 **/
	return (((gint64) tp.tv_sec) + monotonic_timestamp_offset_sec) * ((gint64) G_USEC_PER_SEC) +
	       (tp.tv_nsec / (NM_UTILS_NS_PER_SECOND/G_USEC_PER_SEC));
}

/**
 * nm_utils_get_monotonic_timestamp_ms:
 *
 * Returns: a monotonically increasing time stamp in milliseconds,
 * starting at an unspecified offset. See clock_gettime(), %CLOCK_BOOTTIME.
 *
 * The returned value will start counting at an undefined point
 * in the past and will always be positive.
 *
 * All the nm_utils_get_monotonic_timestamp_*s functions return the same
 * timestamp but in different scales (nsec, usec, msec, sec).
 **/
gint64
nm_utils_get_monotonic_timestamp_ms (void)
{
	struct timespec tp = { 0 };

	monotonic_timestamp_get (&tp);

	/* Although the result will always be positive, we return a signed
	 * integer, which makes it easier to calculate time differences (when
	 * you want to subtract signed values).
	 **/
	return (((gint64) tp.tv_sec) + monotonic_timestamp_offset_sec) * ((gint64) 1000) +
	       (tp.tv_nsec / (NM_UTILS_NS_PER_SECOND/1000));
}

/**
 * nm_utils_get_monotonic_timestamp_s:
 *
 * Returns: nm_utils_get_monotonic_timestamp_ms() in seconds (throwing
 * away sub second parts). The returned value will always be positive.
 *
 * This value wraps after roughly 68 years which should be fine for any
 * practical purpose.
 *
 * All the nm_utils_get_monotonic_timestamp_*s functions return the same
 * timestamp but in different scales (nsec, usec, msec, sec).
 **/
gint32
nm_utils_get_monotonic_timestamp_s (void)
{
	struct timespec tp = { 0 };

	monotonic_timestamp_get (&tp);
	return (((gint64) tp.tv_sec) + monotonic_timestamp_offset_sec);
}

typedef struct
{
	const char *name;
	NMSetting *setting;
	NMSetting *diff_base_setting;
	GHashTable *setting_diff;
} LogConnectionSettingData;

typedef struct
{
	const char *item_name;
	NMSettingDiffResult diff_result;
} LogConnectionSettingItem;

static gint
_log_connection_sort_hashes_fcn (gconstpointer a, gconstpointer b)
{
	const LogConnectionSettingData *v1 = a;
	const LogConnectionSettingData *v2 = b;
	guint32 p1, p2;
	NMSetting *s1, *s2;

	s1 = v1->setting ? v1->setting : v1->diff_base_setting;
	s2 = v2->setting ? v2->setting : v2->diff_base_setting;

	g_assert (s1 && s2);

	p1 = _nm_setting_get_setting_priority (s1);
	p2 = _nm_setting_get_setting_priority (s2);

	if (p1 != p2)
		return p1 > p2 ? 1 : -1;

	return strcmp (v1->name, v2->name);
}

static GArray *
_log_connection_sort_hashes (NMConnection *connection, NMConnection *diff_base, GHashTable *connection_diff)
{
	GHashTableIter iter;
	GArray *sorted_hashes;
	LogConnectionSettingData setting_data;

	sorted_hashes = g_array_sized_new (TRUE, FALSE, sizeof (LogConnectionSettingData), g_hash_table_size (connection_diff));

	g_hash_table_iter_init (&iter, connection_diff);
	while (g_hash_table_iter_next (&iter, (gpointer) &setting_data.name, (gpointer) &setting_data.setting_diff)) {
		setting_data.setting = nm_connection_get_setting_by_name (connection, setting_data.name);
		setting_data.diff_base_setting = diff_base ? nm_connection_get_setting_by_name (diff_base, setting_data.name) : NULL;
		g_assert (setting_data.setting || setting_data.diff_base_setting);
		g_array_append_val (sorted_hashes, setting_data);
	}

	g_array_sort (sorted_hashes, _log_connection_sort_hashes_fcn);
	return sorted_hashes;
}

static gint
_log_connection_sort_names_fcn (gconstpointer a, gconstpointer b)
{
	const LogConnectionSettingItem *v1 = a;
	const LogConnectionSettingItem *v2 = b;

	/* we want to first show the items, that disappeared, then the one that changed and
	 * then the ones that were added. */

	if ((v1->diff_result & NM_SETTING_DIFF_RESULT_IN_A) != (v2->diff_result & NM_SETTING_DIFF_RESULT_IN_A))
		return (v1->diff_result & NM_SETTING_DIFF_RESULT_IN_A) ? -1 : 1;
	if ((v1->diff_result & NM_SETTING_DIFF_RESULT_IN_B) != (v2->diff_result & NM_SETTING_DIFF_RESULT_IN_B))
		return (v1->diff_result & NM_SETTING_DIFF_RESULT_IN_B) ? 1 : -1;
	return strcmp (v1->item_name, v2->item_name);
}

static char *
_log_connection_get_property (NMSetting *setting, const char *name)
{
	GValue val = G_VALUE_INIT;
	char *s;

	g_return_val_if_fail (setting, NULL);

	if (   !NM_IS_SETTING_VPN (setting)
	    && nm_setting_get_secret_flags (setting, name, NULL, NULL))
		return g_strdup ("****");

	if (!_nm_setting_get_property (setting, name, &val))
		g_return_val_if_reached (FALSE);

	if (G_VALUE_HOLDS_STRING (&val)) {
		const char *val_s;

		val_s = g_value_get_string (&val);
		if (!val_s) {
			/* for NULL, we want to return the unquoted string "NULL". */
			s = g_strdup ("NULL");
		} else {
			char *escaped = g_strescape (val_s, "'");

			s = g_strdup_printf ("'%s'", escaped);
			g_free (escaped);
		}
	} else {
		s = g_strdup_value_contents (&val);
		if (s == NULL)
			s = g_strdup ("NULL");
		else {
			char *escaped = g_strescape (s, "'");

			g_free (s);
			s = escaped;
		}
	}
	g_value_unset(&val);
	return s;
}

static void
_log_connection_sort_names (LogConnectionSettingData *setting_data, GArray *sorted_names)
{
	GHashTableIter iter;
	LogConnectionSettingItem item;
	gpointer p;

	g_array_set_size (sorted_names, 0);

	g_hash_table_iter_init (&iter, setting_data->setting_diff);
	while (g_hash_table_iter_next (&iter, (gpointer) &item.item_name, &p)) {
		item.diff_result = GPOINTER_TO_UINT (p);
		g_array_append_val (sorted_names, item);
	}

	g_array_sort (sorted_names, _log_connection_sort_names_fcn);
}

void
nm_utils_log_connection_diff (NMConnection *connection, NMConnection *diff_base, guint32 level, guint64 domain, const char *name, const char *prefix)
{
	GHashTable *connection_diff = NULL;
	GArray *sorted_hashes;
	GArray *sorted_names = NULL;
	int i, j;
	gboolean connection_diff_are_same;
	gboolean print_header = TRUE;
	gboolean print_setting_header;
	GString *str1;

	g_return_if_fail (NM_IS_CONNECTION (connection));
	g_return_if_fail (!diff_base || (NM_IS_CONNECTION (diff_base) && diff_base != connection));

	/* For VPN setting types, this is broken, because we cannot (generically) print the content of data/secrets. Bummer... */

	if (!nm_logging_enabled (level, domain))
		return;

	if (!prefix)
		prefix = "";
	if (!name)
		name = "";

	connection_diff_are_same = nm_connection_diff (connection, diff_base, NM_SETTING_COMPARE_FLAG_EXACT | NM_SETTING_COMPARE_FLAG_DIFF_RESULT_NO_DEFAULT, &connection_diff);
	if (connection_diff_are_same) {
		if (diff_base)
			nm_log (level, domain, "%sconnection '%s' (%p/%s and %p/%s): no difference", prefix, name, connection, G_OBJECT_TYPE_NAME (connection), diff_base, G_OBJECT_TYPE_NAME (diff_base));
		else
			nm_log (level, domain, "%sconnection '%s' (%p/%s): no properties set", prefix, name, connection, G_OBJECT_TYPE_NAME (connection));
		g_assert (!connection_diff);
		return;
	}

	/* FIXME: it doesn't nicely show the content of NMSettingVpn, becuase nm_connection_diff() does not
	 * expand the hash values. */

	sorted_hashes = _log_connection_sort_hashes (connection, diff_base, connection_diff);
	if (sorted_hashes->len <= 0)
		goto out;

	sorted_names = g_array_new (FALSE, FALSE, sizeof (LogConnectionSettingItem));
	str1 = g_string_new (NULL);

	for (i = 0; i < sorted_hashes->len; i++) {
		LogConnectionSettingData *setting_data = &g_array_index (sorted_hashes, LogConnectionSettingData, i);

		_log_connection_sort_names (setting_data, sorted_names);
		print_setting_header = TRUE;
		for (j = 0; j < sorted_names->len; j++) {
			char *str_conn, *str_diff;
			LogConnectionSettingItem *item = &g_array_index (sorted_names, LogConnectionSettingItem, j);

			str_conn = (item->diff_result & NM_SETTING_DIFF_RESULT_IN_A)
			           ? _log_connection_get_property (setting_data->setting, item->item_name)
			           : NULL;
			str_diff = (item->diff_result & NM_SETTING_DIFF_RESULT_IN_B)
			           ? _log_connection_get_property (setting_data->diff_base_setting, item->item_name)
			           : NULL;

			if (print_header) {
				GError *err_verify = NULL;
				const char *path = nm_connection_get_path (connection);

				if (diff_base) {
					nm_log (level, domain, "%sconnection '%s' (%p/%s < %p/%s)%s%s%s:", prefix, name, connection, G_OBJECT_TYPE_NAME (connection), diff_base, G_OBJECT_TYPE_NAME (diff_base),
					        NM_PRINT_FMT_QUOTED (path, " [", path, "]", ""));
				} else {
					nm_log (level, domain, "%sconnection '%s' (%p/%s):%s%s%s", prefix, name, connection, G_OBJECT_TYPE_NAME (connection),
					        NM_PRINT_FMT_QUOTED (path, " [", path, "]", ""));
				}
				print_header = FALSE;

				if (!nm_connection_verify (connection, &err_verify)) {
					nm_log (level, domain, "%sconnection %p does not verify: %s", prefix, connection, err_verify->message);
					g_clear_error (&err_verify);
				}
			}
#define _NM_LOG_ALIGN "-25"
			if (print_setting_header) {
				if (diff_base) {
					if (setting_data->setting && setting_data->diff_base_setting)
						g_string_printf (str1, "%p < %p", setting_data->setting, setting_data->diff_base_setting);
					else if (setting_data->diff_base_setting)
						g_string_printf (str1, "*missing* < %p", setting_data->diff_base_setting);
					else
						g_string_printf (str1, "%p < *missing*", setting_data->setting);
					nm_log (level, domain, "%s%"_NM_LOG_ALIGN"s [ %s ]", prefix, setting_data->name, str1->str);
				} else
					nm_log (level, domain, "%s%"_NM_LOG_ALIGN"s [ %p ]", prefix, setting_data->name, setting_data->setting);
				print_setting_header = FALSE;
			}
			g_string_printf (str1, "%s.%s", setting_data->name, item->item_name);
			switch (item->diff_result & (NM_SETTING_DIFF_RESULT_IN_A | NM_SETTING_DIFF_RESULT_IN_B)) {
				case NM_SETTING_DIFF_RESULT_IN_B:
					nm_log (level, domain, "%s%"_NM_LOG_ALIGN"s < %s", prefix, str1->str, str_diff ? str_diff : "NULL");
					break;
				case NM_SETTING_DIFF_RESULT_IN_A:
					nm_log (level, domain, "%s%"_NM_LOG_ALIGN"s = %s", prefix, str1->str, str_conn ? str_conn : "NULL");
					break;
				default:
					nm_log (level, domain, "%s%"_NM_LOG_ALIGN"s = %s < %s", prefix, str1->str, str_conn ? str_conn : "NULL", str_diff ? str_diff : "NULL");
					break;
#undef _NM_LOG_ALIGN
			}
			g_free (str_conn);
			g_free (str_diff);
		}
	}

	g_array_free (sorted_names, TRUE);
	g_string_free (str1, TRUE);
out:
	g_hash_table_destroy (connection_diff);
	g_array_free (sorted_hashes, TRUE);
}

/**
 * nm_utils_monotonic_timestamp_as_boottime:
 * @timestamp: the monotonic-timestamp that should be converted into CLOCK_BOOTTIME.
 * @timestamp_ns_per_tick: How many nano seconds make one unit of @timestamp? E.g. if
 * @timestamp is in unit seconds, pass %NM_UTILS_NS_PER_SECOND; @timestamp in nano
 * seconds, pass 1; @timestamp in milli seconds, pass %NM_UTILS_NS_PER_SECOND/1000; etc.
 *
 * Returns: the monotonic-timestamp as CLOCK_BOOTTIME, as returned by clock_gettime().
 * The unit is the same as the passed in @timestamp basd on @timestamp_ns_per_tick.
 * E.g. if you passed @timestamp in as seconds, it will return boottime in seconds.
 * If @timestamp is a non-positive, it returns -1. Note that a (valid) monotonic-timestamp
 * is always positive.
 *
 * On older kernels that don't support CLOCK_BOOTTIME, the returned time is instead CLOCK_MONOTONIC.
 **/
gint64
nm_utils_monotonic_timestamp_as_boottime (gint64 timestamp, gint64 timestamp_ns_per_tick)
{
	gint64 offset;

	/* only support ns-per-tick being a multiple of 10. */
	g_return_val_if_fail (timestamp_ns_per_tick == 1
	                      || (timestamp_ns_per_tick > 0 &&
	                          timestamp_ns_per_tick <= NM_UTILS_NS_PER_SECOND &&
	                          timestamp_ns_per_tick % 10 == 0),
	                      -1);

	/* Check that the timestamp is in a valid range. */
	g_return_val_if_fail (timestamp >= 0, -1);

	/* if the caller didn't yet ever fetch a monotonic-timestamp, he cannot pass any meaningful
	 * value (because he has no idea what these timestamps would be). That would be a bug. */
	g_return_val_if_fail (monotonic_timestamp_clock_mode != 0, -1);

	/* calculate the offset of monotonic-timestamp to boottime. offset_s is <= 1. */
	offset = monotonic_timestamp_offset_sec * (NM_UTILS_NS_PER_SECOND / timestamp_ns_per_tick);

	/* check for overflow. */
	g_return_val_if_fail (offset > 0 || timestamp < G_MAXINT64 + offset, G_MAXINT64);

	return timestamp - offset;
}


#define IPV6_PROPERTY_DIR "/proc/sys/net/ipv6/conf/"
#define IPV4_PROPERTY_DIR "/proc/sys/net/ipv4/conf/"
G_STATIC_ASSERT (sizeof (IPV4_PROPERTY_DIR) == sizeof (IPV6_PROPERTY_DIR));

static const char *
_get_property_path (const char *ifname,
                    const char *property,
                    gboolean ipv6)
{
	static char path[sizeof (IPV6_PROPERTY_DIR) + IFNAMSIZ + 32];
	int len;

	ifname = NM_ASSERT_VALID_PATH_COMPONENT (ifname);
	property = NM_ASSERT_VALID_PATH_COMPONENT (property);

	len = g_snprintf (path,
	                  sizeof (path),
	                  "%s%s/%s",
	                  ipv6 ? IPV6_PROPERTY_DIR : IPV4_PROPERTY_DIR,
	                  ifname,
	                  property);
	g_assert (len < sizeof (path) - 1);

	return path;
}

/**
 * nm_utils_ip6_property_path:
 * @ifname: an interface name
 * @property: a property name
 *
 * Returns the path to IPv6 property @property on @ifname. Note that
 * this uses a static buffer.
 */
const char *
nm_utils_ip6_property_path (const char *ifname, const char *property)
{
	return _get_property_path (ifname, property, TRUE);
}

/**
 * nm_utils_ip4_property_path:
 * @ifname: an interface name
 * @property: a property name
 *
 * Returns the path to IPv4 property @property on @ifname. Note that
 * this uses a static buffer.
 */
const char *
nm_utils_ip4_property_path (const char *ifname, const char *property)
{
	return _get_property_path (ifname, property, FALSE);
}

gboolean
nm_utils_is_valid_path_component (const char *name)
{
	const char *n;

	if (name == NULL || name[0] == '\0')
		return FALSE;

	if (name[0] == '.') {
		if (name[1] == '\0')
			return FALSE;
		if (name[1] == '.' && name[2] == '\0')
			return FALSE;
	}
	n = name;
	do {
		if (*n == '/')
			return FALSE;
	} while (*(++n) != '\0');

	return TRUE;
}

const char *
NM_ASSERT_VALID_PATH_COMPONENT (const char *name)
{
	if (G_LIKELY (nm_utils_is_valid_path_component (name)))
		return name;

	nm_log_err (LOGD_CORE, "Failed asserting path component: %s%s%s",
	            NM_PRINT_FMT_QUOTED (name, "\"", name, "\"", "(null)"));
	g_error ("FATAL: Failed asserting path component: %s%s%s",
	         NM_PRINT_FMT_QUOTED (name, "\"", name, "\"", "(null)"));
	g_assert_not_reached ();
}

gboolean
nm_utils_is_specific_hostname (const char *name)
{
	if (!name)
		return FALSE;
	if (   strcmp (name, "(none)")
	    && strcmp (name, "localhost")
	    && strcmp (name, "localhost6")
	    && strcmp (name, "localhost.localdomain")
	    && strcmp (name, "localhost6.localdomain6"))
		return TRUE;
	return FALSE;
}

/*****************************************************************************/

gboolean
nm_utils_machine_id_parse (const char *id_str, /*uuid_t*/ guchar *out_uuid)
{
	int i;
	guint8 v0, v1;

	if (!id_str)
		return FALSE;

	for (i = 0; i < 32; i++) {
		if (!g_ascii_isxdigit (id_str[i]))
			return FALSE;
	}
	if (id_str[i] != '\0')
		return FALSE;

	if (out_uuid) {
		for (i = 0; i < 16; i++) {
			v0 = g_ascii_xdigit_value (*(id_str++));
			v1 = g_ascii_xdigit_value (*(id_str++));
			out_uuid[i] = (v0 << 4) + v1;
		}
	}
	return TRUE;
}

char *
nm_utils_machine_id_read (void)
{
	gs_free char *contents = NULL;
	int i;

	/* Get the machine ID from /etc/machine-id; it's always in /etc no matter
	 * where our configured SYSCONFDIR is.  Alternatively, it might be in
	 * LOCALSTATEDIR /lib/dbus/machine-id.
	 */
	if (   !g_file_get_contents ("/etc/machine-id", &contents, NULL, NULL)
	    && !g_file_get_contents (LOCALSTATEDIR "/lib/dbus/machine-id", &contents, NULL, NULL))
		return FALSE;

	contents = g_strstrip (contents);

	for (i = 0; i < 32; i++) {
		if (!g_ascii_isxdigit (contents[i]))
			return FALSE;
		if (contents[i] >= 'A' && contents[i] <= 'F') {
			/* canonicalize to lower-case */
			contents[i] = 'a' + (contents[i] - 'A');
		}
	}
	if (contents[i] != '\0')
		return FALSE;

	return g_steal_pointer (&contents);
}

/*****************************************************************************/

/* taken from systemd's fd_wait_for_event(). Note that the timeout
 * is here in nano-seconds, not micro-seconds. */
int
nm_utils_fd_wait_for_event (int fd, int event, gint64 timeout_ns)
{
	struct pollfd pollfd = {
		.fd = fd,
		.events = event,
	};
	struct timespec ts, *pts;
	int r;

	if (timeout_ns < 0)
		pts = NULL;
	else {
		ts.tv_sec = (time_t) (timeout_ns / NM_UTILS_NS_PER_SECOND);
		ts.tv_nsec = (long int) (timeout_ns % NM_UTILS_NS_PER_SECOND);
		pts = &ts;
	}

	r = ppoll (&pollfd, 1, pts, NULL);
	if (r < 0)
		return -errno;
	if (r == 0)
		return 0;
	return pollfd.revents;
}

/* taken from systemd's loop_read() */
ssize_t
nm_utils_fd_read_loop (int fd, void *buf, size_t nbytes, bool do_poll)
{
	uint8_t *p = buf;
	ssize_t n = 0;

	g_return_val_if_fail (fd >= 0, -EINVAL);
	g_return_val_if_fail (buf, -EINVAL);

	/* If called with nbytes == 0, let's call read() at least
	 * once, to validate the operation */

	if (nbytes > (size_t) SSIZE_MAX)
		return -EINVAL;

	do {
		ssize_t k;

		k = read (fd, p, nbytes);
		if (k < 0) {
			if (errno == EINTR)
				continue;

			if (errno == EAGAIN && do_poll) {

				/* We knowingly ignore any return value here,
				 * and expect that any error/EOF is reported
				 * via read() */

				(void) nm_utils_fd_wait_for_event (fd, POLLIN, -1);
				continue;
			}

			return n > 0 ? n : -errno;
		}

		if (k == 0)
			return n;

		g_assert ((size_t) k <= nbytes);

		p += k;
		nbytes -= k;
		n += k;
	} while (nbytes > 0);

	return n;
}

/* taken from systemd's loop_read_exact() */
int
nm_utils_fd_read_loop_exact (int fd, void *buf, size_t nbytes, bool do_poll)
{
	ssize_t n;

	n = nm_utils_fd_read_loop (fd, buf, nbytes, do_poll);
	if (n < 0)
		return (int) n;
	if ((size_t) n != nbytes)
		return -EIO;

	return 0;
}

_nm_printf (3, 4)
static int
_get_contents_error (GError **error, int errsv, const char *format, ...)
{
	if (errsv < 0)
		errsv = -errsv;
	else if (!errsv)
		errsv = errno;

	if (error) {
		char *msg;
		va_list args;

		va_start (args, format);
		msg = g_strdup_vprintf (format, args);
		va_end (args);
		g_set_error (error,
		             G_FILE_ERROR,
		             g_file_error_from_errno (errsv),
		             "%s: %s",
		             msg, g_strerror (errsv));
		g_free (msg);
	}
	return -errsv;
}

/**
 * nm_utils_fd_get_contents:
 * @fd: open file descriptor to read. The fd will not be closed,
 *   but don't rely on it's state afterwards.
 * @max_length: allocate at most @max_length bytes. If the
 *   file is larger, reading will fail. Set to zero to use
 *   a very large default.
 *
 *   WARNING: @max_length is here to avoid a crash for huge/unlimited files.
 *   For example, stat(/sys/class/net/enp0s25/ifindex) gives a filesize of
 *   4K, although the actual real is small. @max_length is the memory
 *   allocated in the process of reading the file, thus it must be at least
 *   the size reported by fstat.
 *   If you set it to 1K, read will fail because fstat() claims the
 *   file is larger.
 *
 * @contents: the output buffer with the file read. It is always
 *   NUL terminated. The buffer is at most @max_length long, including
 *  the NUL byte. That is, it reads only files up to a length of
 *  @max_length - 1 bytes.
 * @length: optional output argument of the read file size.
 *
 * A reimplementation of g_file_get_contents() with a few differences:
 *   - accepts an open fd, instead of a path name. This allows you to
 *     use openat().
 *   - limits the maxium filesize to max_length.
 *
 * Returns: a negative error code on failure.
 */
int
nm_utils_fd_get_contents (int fd,
                          gsize max_length,
                          char **contents,
                          gsize *length,
                          GError **error)
{
	struct stat stat_buf;
	gs_free char *str = NULL;

	g_return_val_if_fail (fd >= 0, -EINVAL);
	g_return_val_if_fail (contents, -EINVAL);
	g_return_val_if_fail (!error || !*error, -EINVAL);

	if (fstat (fd, &stat_buf) < 0)
		return _get_contents_error (error, 0, "failure during fstat");

	if (!max_length) {
		/* default to a very large size, but not extreme */
		max_length = 2 * 1024 * 1024;
	}

	if (   stat_buf.st_size > 0
	    && S_ISREG (stat_buf.st_mode)) {
		const gsize n_stat = stat_buf.st_size;
		ssize_t n_read;

		if (n_stat > max_length - 1)
			return _get_contents_error (error, EMSGSIZE, "file too large (%zu+1 bytes with maximum %zu bytes)", n_stat, max_length);

		str = g_try_malloc (n_stat + 1);
		if (!str)
			return _get_contents_error (error, ENOMEM, "failure to allocate buffer of %zu+1 bytes", n_stat);

		n_read = nm_utils_fd_read_loop (fd, str, n_stat, TRUE);
		if (n_read < 0)
			return _get_contents_error (error, n_read, "error reading %zu bytes from file descriptor", n_stat);
		str[n_read] = '\0';

		if (n_read < n_stat) {
			char *tmp;

			tmp = g_try_realloc (str, n_read + 1);
			if (!tmp)
				return _get_contents_error (error, ENOMEM, "failure to reallocate buffer with %zu bytes", n_read + 1);
			str = tmp;
		}
		NM_SET_OUT (length, n_read);
	} else {
		nm_auto_fclose FILE *f = NULL;
		char buf[4096];
		gsize n_have, n_alloc;

		if (!(f = fdopen (fd, "r")))
			return _get_contents_error (error, 0, "failure during fdopen");

		n_have = 0;
		n_alloc = 0;

		while (!feof (f)) {
			int errsv;
			gsize n_read;

			n_read = fread (buf, 1, sizeof (buf), f);
			errsv = errno;
			if (ferror (f))
				return _get_contents_error (error, errsv, "error during fread");

			if (   n_have > G_MAXSIZE - 1 - n_read
			    || n_have + n_read + 1 > max_length) {
				return _get_contents_error (error, EMSGSIZE, "file stream too large (%zu+1 bytes with maximum %zu bytes)",
				                            (n_have > G_MAXSIZE - 1 - n_read) ? G_MAXSIZE : n_have + n_read,
				                            max_length);
			}

			if (n_have + n_read + 1 >= n_alloc) {
				char *tmp;

				if (str) {
					if (n_alloc >= max_length / 2)
						n_alloc = max_length;
					else
						n_alloc *= 2;
				} else
					n_alloc = NM_MIN (n_read + 1, sizeof (buf));

				tmp = g_try_realloc (str, n_alloc);
				if (!tmp)
					return _get_contents_error (error, ENOMEM, "failure to allocate buffer of %zu bytes", n_alloc);
				str = tmp;
			}

			memcpy (str + n_have, buf, n_read);
			n_have += n_read;
		}

		if (n_alloc == 0)
			str = g_new0 (gchar, 1);
		else {
			str[n_have] = '\0';
			if (n_have + 1 < n_alloc) {
				char *tmp;

				tmp = g_try_realloc (str, n_have + 1);
				if (!tmp)
					return _get_contents_error (error, ENOMEM, "failure to truncate buffer to %zu bytes", n_have + 1);
				str = tmp;
			}
		}

		NM_SET_OUT (length, n_have);
	}

	*contents = g_steal_pointer (&str);
	return 0;
}

/**
 * nm_utils_file_get_contents:
 * @dirfd: optional file descriptor to use openat(). If negative, use plain open().
 * @filename: the filename to open. Possibly relative to @dirfd.
 * @max_length: allocate at most @max_length bytes.
 *   WARNING: see nm_utils_fd_get_contents() hint about @max_length.
 * @contents: the output buffer with the file read. It is always
 *   NUL terminated. The buffer is at most @max_length long, including
 *  the NUL byte. That is, it reads only files up to a length of
 *  @max_length - 1 bytes.
 * @length: optional output argument of the read file size.
 *
 * A reimplementation of g_file_get_contents() with a few differences:
 *   - accepts an @dirfd to open @filename relative to that path via openat().
 *   - limits the maxium filesize to max_length.
 *   - uses O_CLOEXEC on internal file descriptor
 *
 * Returns: a negative error code on failure.
 */
int
nm_utils_file_get_contents (int dirfd,
                            const char *filename,
                            gsize max_length,
                            char **contents,
                            gsize *length,
                            GError **error)
{
	nm_auto_close int fd = -1;
	int errsv;

	g_return_val_if_fail (filename && filename[0], -EINVAL);

	if (dirfd >= 0) {
		fd = openat (dirfd, filename, O_RDONLY | O_CLOEXEC);
		if (fd < 0) {
			errsv = errno;

			g_set_error (error,
			             G_FILE_ERROR,
			             g_file_error_from_errno (errsv),
			             "Failed to open file \"%s\" with openat: %s",
			             filename,
			             g_strerror (errsv));
			return -errsv;
		}
	} else {
		fd = open (filename, O_RDONLY | O_CLOEXEC);
		if (fd < 0) {
			errsv = errno;

			g_set_error (error,
			             G_FILE_ERROR,
			             g_file_error_from_errno (errsv),
			             "Failed to open file \"%s\": %s",
			             filename,
			             g_strerror (errsv));
			return -errsv;
		}
	}
	return nm_utils_fd_get_contents (fd,
	                                 max_length,
	                                 contents,
	                                 length,
	                                 error);
}

/*****************************************************************************/

/* taken from systemd's dev_urandom(). */
int
nm_utils_read_urandom (void *p, size_t nbytes)
{
	int fd = -1;
	int r;

again:
	fd = open ("/dev/urandom", O_RDONLY | O_CLOEXEC | O_NOCTTY);
	if (fd < 0) {
		r = errno;
		if (r == EINTR)
			goto again;
		return r == ENOENT ? -ENOSYS : -r;
	}

	r = nm_utils_fd_read_loop_exact (fd, p, nbytes, TRUE);
	close (fd);

	return r;
}

/*****************************************************************************/

guint8 *
nm_utils_secret_key_read (gsize *out_key_len, GError **error)
{
	guint8 *secret_key = NULL;
	gsize key_len;

	/* out_key_len is not optional, because without it you cannot safely
	 * access the returned memory. */
	*out_key_len = 0;

	/* Let's try to load a saved secret key first. */
	if (g_file_get_contents (NMSTATEDIR "/secret_key", (char **) &secret_key, &key_len, NULL)) {
		if (key_len < 16) {
			g_set_error_literal (error, NM_UTILS_ERROR, NM_UTILS_ERROR_UNKNOWN,
			                     "Key is too short to be usable");
			key_len = 0;
		}
	} else {
		int r;
		mode_t key_mask;

		/* RFC7217 mandates the key SHOULD be at least 128 bits.
		 * Let's use twice as much. */
		key_len = 32;
		secret_key = g_malloc (key_len);

		r = nm_utils_read_urandom (secret_key, key_len);
		if (r < 0) {
			g_set_error (error, NM_UTILS_ERROR, NM_UTILS_ERROR_UNKNOWN,
			             "Can't read /dev/urandom: %s", strerror (-r));
			key_len = 0;
			goto out;
		}

		key_mask = umask (0077);
		if (!g_file_set_contents (NMSTATEDIR "/secret_key", (char *) secret_key, key_len, error)) {
			g_prefix_error (error, "Can't write " NMSTATEDIR "/secret_key: ");
			key_len = 0;
		}
		umask (key_mask);
	}

out:
	if (key_len) {
		*out_key_len = key_len;
		return secret_key;
	}
	g_free (secret_key);
	return NULL;
}

/*****************************************************************************/

const char *
nm_utils_get_boot_id (void)
{
	static const char *boot_id;

	if (G_UNLIKELY (!boot_id)) {
		gs_free char *contents = NULL;

		nm_utils_file_get_contents (-1, "/proc/sys/kernel/random/boot_id", 0,
		                            &contents, NULL, NULL);
		if (contents) {
			g_strstrip (contents);
			if (contents[0]) {
				/* clone @contents because we keep @boot_id until the program
				 * ends.
				 * nm_utils_file_get_contents() likely allocated a larger
				 * buffer chunk initially and (although using realloc to shrink
				 * the buffer) it might not be best to keep this memory
				 * around. */
				boot_id = g_strdup (contents);
			}
		}
		if (!boot_id)
			boot_id = nm_utils_uuid_generate ();
	}

	return boot_id;
}

/*****************************************************************************/

/* Returns the "u" (universal/local) bit value for a Modified EUI-64 */
static gboolean
get_gre_eui64_u_bit (guint32 addr)
{
	static const struct {
		guint32 mask;
		guint32 result;
	} items[] = {
		{ 0xff000000 }, { 0x7f000000 },  /* IPv4 loopback */
		{ 0xf0000000 }, { 0xe0000000 },  /* IPv4 multicast */
		{ 0xffffff00 }, { 0xe0000000 },  /* IPv4 local multicast */
		{ 0xffffffff }, { INADDR_BROADCAST },  /* limited broadcast */
		{ 0xff000000 }, { 0x00000000 },  /* zero net */
		{ 0xff000000 }, { 0x0a000000 },  /* private 10 (RFC3330) */
		{ 0xfff00000 }, { 0xac100000 },  /* private 172 */
		{ 0xffff0000 }, { 0xc0a80000 },  /* private 192 */
		{ 0xffff0000 }, { 0xa9fe0000 },  /* IPv4 link-local */
		{ 0xffffff00 }, { 0xc0586300 },  /* anycast 6-to-4 */
		{ 0xffffff00 }, { 0xc0000200 },  /* test 192 */
		{ 0xfffe0000 }, { 0xc6120000 },  /* test 198 */
	};
	guint i;

	for (i = 0; i < G_N_ELEMENTS (items); i++) {
		if ((addr & htonl (items[i].mask)) == htonl (items[i].result))
			return 0x00; /* "local" scope */
	}
	return 0x02; /* "universal" scope */
}

/**
 * nm_utils_get_ipv6_interface_identifier:
 * @link_type: the hardware link type
 * @hwaddr: the hardware address of the interface
 * @hwaddr_len: the length (in bytes) of @hwaddr
 * @dev_id: the device identifier, if any
 * @out_iid: on success, filled with the interface identifier; on failure
 * zeroed out
 *
 * Constructs an interface identifier in "Modified EUI-64" format which is
 * suitable for constructing IPv6 addresses.  Note that the identifier is
 * not obscured in any way (eg, RFC3041).
 *
 * Returns: %TRUE if the interface identifier could be constructed, %FALSE if
 * if could not be constructed.
 */
gboolean
nm_utils_get_ipv6_interface_identifier (NMLinkType link_type,
                                        const guint8 *hwaddr,
                                        guint hwaddr_len,
                                        guint dev_id,
                                        NMUtilsIPv6IfaceId *out_iid)
{
	guint32 addr;

	g_return_val_if_fail (hwaddr != NULL, FALSE);
	g_return_val_if_fail (hwaddr_len > 0, FALSE);
	g_return_val_if_fail (out_iid != NULL, FALSE);

	out_iid->id = 0;

	switch (link_type) {
	case NM_LINK_TYPE_INFINIBAND:
		/* Use the port GUID per http://tools.ietf.org/html/rfc4391#section-8,
		 * making sure to set the 'u' bit to 1.  The GUID is the lower 64 bits
		 * of the IPoIB interface's hardware address.
		 */
		g_return_val_if_fail (hwaddr_len == INFINIBAND_ALEN, FALSE);
		memcpy (out_iid->id_u8, hwaddr + INFINIBAND_ALEN - 8, 8);
		out_iid->id_u8[0] |= 0x02;
		return TRUE;
	case NM_LINK_TYPE_GRE:
	case NM_LINK_TYPE_GRETAP:
		/* Hardware address is the network-endian IPv4 address */
		g_return_val_if_fail (hwaddr_len == 4, FALSE);
		addr = * (guint32 *) hwaddr;
		out_iid->id_u8[0] = get_gre_eui64_u_bit (addr);
		out_iid->id_u8[1] = 0x00;
		out_iid->id_u8[2] = 0x5E;
		out_iid->id_u8[3] = 0xFE;
		memcpy (out_iid->id_u8 + 4, &addr, 4);
		return TRUE;
	default:
		if (hwaddr_len == ETH_ALEN) {
			/* Translate 48-bit MAC address to a 64-bit Modified EUI-64.  See
			 * http://tools.ietf.org/html/rfc4291#appendix-A and the Linux
			 * kernel's net/ipv6/addrconf.c::ipv6_generate_eui64() function.
			 */
			out_iid->id_u8[0] = hwaddr[0];
			out_iid->id_u8[1] = hwaddr[1];
			out_iid->id_u8[2] = hwaddr[2];
			if (dev_id) {
				out_iid->id_u8[3] = (dev_id >> 8) & 0xff;
				out_iid->id_u8[4] = dev_id & 0xff;
			} else {
				out_iid->id_u8[0] ^= 0x02;
				out_iid->id_u8[3] = 0xff;
				out_iid->id_u8[4] = 0xfe;
			}
			out_iid->id_u8[5] = hwaddr[3];
			out_iid->id_u8[6] = hwaddr[4];
			out_iid->id_u8[7] = hwaddr[5];
			return TRUE;
		}
		break;
	}
	return FALSE;
}

/*****************************************************************************/

/**
 * nm_utils_ipv6_addr_set_interface_identifier:
 * @addr: output token encoded as %in6_addr
 * @iid: %NMUtilsIPv6IfaceId interface identifier
 *
 * Converts the %NMUtilsIPv6IfaceId to an %in6_addr (suitable for use
 * with Linux platform). This only copies the lower 8 bytes, ignoring
 * the /64 network prefix which is expected to be all-zero for a valid
 * token.
 */
void
nm_utils_ipv6_addr_set_interface_identifier (struct in6_addr *addr,
                                            const NMUtilsIPv6IfaceId iid)
{
	memcpy (addr->s6_addr + 8, &iid.id_u8, 8);
}

/**
 * nm_utils_ipv6_interface_identifier_get_from_addr:
 * @iid: output %NMUtilsIPv6IfaceId interface identifier set from the token
 * @addr: token encoded as %in6_addr
 *
 * Converts the %in6_addr encoded token (as used by Linux platform) to
 * the interface identifier.
 */
void
nm_utils_ipv6_interface_identifier_get_from_addr (NMUtilsIPv6IfaceId *iid,
                                                 const struct in6_addr *addr)
{
	memcpy (iid, addr->s6_addr + 8, 8);
}

/**
 * nm_utils_ipv6_interface_identifier_get_from_token:
 * @iid: output %NMUtilsIPv6IfaceId interface identifier set from the token
 * @token: token encoded as string
 *
 * Converts the %in6_addr encoded token (as used in ip6 settings) to
 * the interface identifier.
 *
 * Returns: %TRUE if the @token is a valid token, %FALSE otherwise
 */
gboolean
nm_utils_ipv6_interface_identifier_get_from_token (NMUtilsIPv6IfaceId *iid,
                                                  const char *token)
{
	struct in6_addr i6_token;

	g_return_val_if_fail (token, FALSE);

	if (!inet_pton (AF_INET6, token, &i6_token))
		return FALSE;

	if (!_nm_utils_inet6_is_token (&i6_token))
		return FALSE;

	nm_utils_ipv6_interface_identifier_get_from_addr (iid, &i6_token);
	return TRUE;
}

/**
 * nm_utils_inet6_interface_identifier_to_token:
 * @iid: %NMUtilsIPv6IfaceId interface identifier
 * @buf: the destination buffer or %NULL
 *
 * Converts the interface identifier to a string token.
 * If the destination buffer it set, set it is used to store the
 * resulting token, otherwise an internal static buffer is used.
 * The buffer needs to be %NM_UTILS_INET_ADDRSTRLEN characters long.
 *
 * Returns: a statically allocated array. Do not g_free().
 */
const char *
nm_utils_inet6_interface_identifier_to_token (NMUtilsIPv6IfaceId iid, char *buf)
{
	struct in6_addr i6_token = { .s6_addr = { 0, } };

	nm_utils_ipv6_addr_set_interface_identifier (&i6_token, iid);
	return nm_utils_inet6_ntop (&i6_token, buf);
}

/*****************************************************************************/

char *
nm_utils_stable_id_random (void)
{
	char buf[15];

	if (nm_utils_read_urandom (buf, sizeof (buf)) < 0)
		g_return_val_if_reached (nm_utils_uuid_generate ());
	return g_base64_encode ((guchar *) buf, sizeof (buf));
}

char *
nm_utils_stable_id_generated_complete (const char *stable_id_generated)
{
	guint8 buf[20];
	GChecksum *sum;
	gsize buf_size;
	char *base64;

	/* for NM_UTILS_STABLE_TYPE_GENERATED we genererate a possibly long string
	 * by doing text-substitutions in nm_utils_stable_id_parse().
	 *
	 * Let's shorten the (possibly) long stable_id to something more compact. */

	g_return_val_if_fail (stable_id_generated, NULL);

	sum = g_checksum_new (G_CHECKSUM_SHA1);
	nm_assert (sum);

	g_checksum_update (sum, (guchar *) stable_id_generated, strlen (stable_id_generated));

	buf_size = sizeof (buf);
	g_checksum_get_digest (sum, buf, &buf_size);
	nm_assert (buf_size == sizeof (buf));

	g_checksum_free (sum);

	/* we don't care to use the sha1 sum in common hex representation.
	 * Use instead base64, it's 27 chars (stripping the padding) vs.
	 * 40. */

	base64 = g_base64_encode ((guchar *) buf, sizeof (buf));
	nm_assert (strlen (base64) == 28);
	nm_assert (base64[27] == '=');

	base64[27] = '\0';
	return base64;
}

static void
_stable_id_append (GString *str,
                   const char *substitution)
{
	if (!substitution)
		substitution = "";
	g_string_append_printf (str, "=%zu{%s}", strlen (substitution), substitution);
}

NMUtilsStableType
nm_utils_stable_id_parse (const char *stable_id,
                          const char *uuid,
                          const char *bootid,
                          char **out_generated)
{
	gsize i, idx_start;
	GString *str = NULL;

	g_return_val_if_fail (out_generated, NM_UTILS_STABLE_TYPE_RANDOM);

	if (!stable_id) {
		out_generated = NULL;
		return NM_UTILS_STABLE_TYPE_UUID;
	}

	/* the stable-id allows for some dynamic by performing text-substitutions
	 * of ${...} patterns.
	 *
	 * At first, it looks a bit like bash parameter substitution.
	 * In contrast however, the process is unambigious so that the resulting
	 * effective id differs if:
	 *  - the original, untranslated stable-id differs
	 *  - or any of the subsitutions differs.
	 *
	 * The reason for that is, for example if you specify "${CONNECTION}" in the
	 * stable-id, then the resulting ID should be always(!) unique for this connection.
	 * There should be no way another connection could specify any stable-id that results
	 * in the same addresses to be generated (aside hash collisions).
	 *
	 *
	 * For example: say you have a connection with UUID
	 * "123e4567-e89b-12d3-a456-426655440000" which happens also to be
	 * the current boot-id.
	 * Then:
	 *   (1) connection.stable-id = <NULL>
	 *   (2) connection.stable-id = "123e4567-e89b-12d3-a456-426655440000"
	 *   (3) connection.stable-id = "${CONNECTION}"
	 *   (3) connection.stable-id = "${BOOT}"
	 * will all generate different addresses, although in one way or the
	 * other, they all mangle the uuid "123e4567-e89b-12d3-a456-426655440000".
	 *
	 * For example, with stable-id="${FOO}${BAR}" the substitutions
	 *   - FOO="ab", BAR="c"
	 *   - FOO="a",  BAR="bc"
	 * should give a different effective id.
	 *
	 * For example, with FOO="x" and BAR="x", the stable-ids
	 *   - "${FOO}${BAR}"
	 *   - "${BAR}${FOO}"
	 * should give a different effective id.
	 */

	idx_start = 0;
	for (i = 0; stable_id[i]; ) {
		if (stable_id[i] != '$') {
			i++;
			continue;
		}

#define CHECK_PREFIX(prefix) \
		({ \
			gboolean _match = FALSE; \
			\
			if (g_str_has_prefix (&stable_id[i], ""prefix"")) { \
				_match = TRUE; \
				if (!str) \
					str = g_string_sized_new (256); \
				i += NM_STRLEN (prefix); \
				g_string_append_len (str, &(stable_id)[idx_start], i - idx_start); \
				idx_start = i; \
			} \
			_match; \
		})
		if (CHECK_PREFIX ("${CONNECTION}"))
			_stable_id_append (str, uuid);
		else if (CHECK_PREFIX ("${BOOT}"))
			_stable_id_append (str, bootid ?: nm_utils_get_boot_id ());
		else if (g_str_has_prefix (&stable_id[i], "${RANDOM}")) {
			/* RANDOM makes not so much sense for cloned-mac-address
			 * as the result is simmilar to specifing "cloned-mac-address=random".
			 * It makes however sense for RFC 7217 Stable Privacy IPv6 addresses
			 * where this is effectively the only way to generate a different
			 * (random) host identifier for each connect.
			 *
			 * With RANDOM, the user can switch the lifetime of the
			 * generated cloned-mac-address and IPv6 host identifier
			 * by toggeling only the stable-id property of the connection.
			 * With RANDOM being the most short-lived, ~non-stable~ variant.
			 */
			if (str)
				g_string_free (str, TRUE);
			*out_generated = NULL;
			return NM_UTILS_STABLE_TYPE_RANDOM;
		} else {
			/* The text following the '$' is not recognized as valid
			 * substitution pattern. Treat it verbatim. */
			i++;

			/* Note that using unrecognized substitution patterns might
			 * yield different results with future versions. Avoid that,
			 * by not using '$' (except for actual substitutions) or escape
			 * it as "$$" (which is guaranteed to be treated verbatim
			 * in future). */
			if (stable_id[i] == '$')
				i++;
		}
	}
#undef CHECK_PREFIX

	if (!str) {
		*out_generated = NULL;
		return NM_UTILS_STABLE_TYPE_STABLE_ID;
	}

	if (idx_start < i)
		g_string_append_len (str, &stable_id[idx_start], i - idx_start);
	*out_generated = g_string_free (str, FALSE);
	return NM_UTILS_STABLE_TYPE_GENERATED;
}

/*****************************************************************************/

static gboolean
_set_stable_privacy (NMUtilsStableType stable_type,
                     struct in6_addr *addr,
                     const char *ifname,
                     const char *network_id,
                     guint dad_counter,
                     guint8 *secret_key,
                     gsize key_len,
                     GError **error)
{
	GChecksum *sum;
	guint8 digest[32];
	guint32 tmp[2];
	gsize len = sizeof (digest);

	nm_assert (key_len);
	nm_assert (network_id);

	/* Documentation suggests that this can fail.
	 * Maybe in case of a missing algorithm in crypto library? */
	sum = g_checksum_new (G_CHECKSUM_SHA256);
	if (!sum) {
		g_set_error_literal (error, NM_UTILS_ERROR, NM_UTILS_ERROR_UNKNOWN,
		                     "Can't create a SHA256 hash");
		return FALSE;
	}

	key_len = MIN (key_len, G_MAXUINT32);

	if (stable_type != NM_UTILS_STABLE_TYPE_UUID) {
		guint8 stable_type_uint8;

		nm_assert (stable_type < (NMUtilsStableType) 255);
		stable_type_uint8 = (guint8) stable_type;

		/* Preferably, we would always like to include the stable-type,
		 * but for backward compatibility reasons, we cannot for UUID.
		 *
		 * That is no real problem and it is still impossible to
		 * force a collision here, because of how the remaining
		 * fields are hashed. That is, as we also hash @key_len
		 * and the terminating '\0' of @network_id, it is unambigiously
		 * possible to revert the process and deduce the @stable_type.
		 */
		g_checksum_update (sum, &stable_type_uint8, sizeof (stable_type_uint8));
	}

	g_checksum_update (sum, addr->s6_addr, 8);
	g_checksum_update (sum, (const guchar *) ifname, strlen (ifname) + 1);
	g_checksum_update (sum, (const guchar *) network_id, strlen (network_id) + 1);
	tmp[0] = htonl (dad_counter);
	tmp[1] = htonl (key_len);
	g_checksum_update (sum, (const guchar *) tmp, sizeof (tmp));
	g_checksum_update (sum, (const guchar *) secret_key, key_len);

	g_checksum_get_digest (sum, digest, &len);
	g_checksum_free (sum);

	g_return_val_if_fail (len == 32, FALSE);

	memcpy (addr->s6_addr + 8, &digest[0], 8);

	return TRUE;
}

gboolean
nm_utils_ipv6_addr_set_stable_privacy_impl (NMUtilsStableType stable_type,
                                            struct in6_addr *addr,
                                            const char *ifname,
                                            const char *network_id,
                                            guint dad_counter,
                                            guint8 *secret_key,
                                            gsize key_len,
                                            GError **error)
{
	return _set_stable_privacy (stable_type, addr, ifname, network_id, dad_counter, secret_key, key_len, error);
}

#define RFC7217_IDGEN_RETRIES 3
/**
 * nm_utils_ipv6_addr_set_stable_privacy:
 *
 * Extend the address prefix with an interface identifier using the
 * RFC 7217 Stable Privacy mechanism.
 *
 * Returns: %TRUE on success, %FALSE if the address could not be generated.
 */
gboolean
nm_utils_ipv6_addr_set_stable_privacy (NMUtilsStableType stable_type,
                                       struct in6_addr *addr,
                                       const char *ifname,
                                       const char *network_id,
                                       guint dad_counter,
                                       GError **error)
{
	gs_free guint8 *secret_key = NULL;
	gsize key_len = 0;

	g_return_val_if_fail (network_id, FALSE);

	if (dad_counter >= RFC7217_IDGEN_RETRIES) {
		g_set_error_literal (error, NM_UTILS_ERROR, NM_UTILS_ERROR_UNKNOWN,
		                     "Too many DAD collisions");
		return FALSE;
	}

	secret_key = nm_utils_secret_key_read (&key_len, error);
	if (!secret_key)
		return FALSE;

	return _set_stable_privacy (stable_type, addr, ifname, network_id, dad_counter,
	                            secret_key, key_len, error);
}

/*****************************************************************************/

static void
_hw_addr_eth_complete (struct ether_addr *addr,
                       const char *current_mac_address,
                       const char *generate_mac_address_mask)
{
	struct ether_addr mask;
	struct ether_addr oui;
	struct ether_addr *ouis;
	gsize ouis_len;
	guint i;

	/* the second LSB of the first octet means
	 * "globally unique, OUI enforced, BIA (burned-in-address)"
	 * vs. "locally-administered". By default, set it to
	 * generate locally-administered addresses.
	 *
	 * Maybe be overwritten by a mask below. */
	addr->ether_addr_octet[0] |= 2;

	if (!generate_mac_address_mask || !*generate_mac_address_mask)
		goto out;
	if (!_nm_utils_generate_mac_address_mask_parse (generate_mac_address_mask,
	                                                &mask,
	                                                &ouis,
	                                                &ouis_len,
	                                                NULL))
		goto out;

	nm_assert ((ouis == NULL) ^ (ouis_len != 0));
	if (ouis) {
		/* g_random_int() is good enough here. It uses a static GRand instance
		 * that is seeded from /dev/urandom. */
		oui = ouis[g_random_int () % ouis_len];
		g_free (ouis);
	} else {
		if (!nm_utils_hwaddr_aton (current_mac_address, &oui, ETH_ALEN))
			goto out;
	}

	for (i = 0; i < ETH_ALEN; i++) {
		const guint8 a = addr->ether_addr_octet[i];
		const guint8 o = oui.ether_addr_octet[i];
		const guint8 m = mask.ether_addr_octet[i];

		addr->ether_addr_octet[i] = (a & ~m) | (o & m);
	}

out:
	/* The LSB of the first octet must always be cleared,
	 * it means Unicast vs. Multicast */
	addr->ether_addr_octet[0] &= ~1;
}

char *
nm_utils_hw_addr_gen_random_eth (const char *current_mac_address,
                                 const char *generate_mac_address_mask)
{
	struct ether_addr bin_addr;

	if (nm_utils_read_urandom (&bin_addr, ETH_ALEN) < 0)
		return NULL;
	_hw_addr_eth_complete (&bin_addr, current_mac_address, generate_mac_address_mask);
	return nm_utils_hwaddr_ntoa (&bin_addr, ETH_ALEN);
}

static char *
_hw_addr_gen_stable_eth (NMUtilsStableType stable_type,
                         const char *stable_id,
                         const guint8 *secret_key,
                         gsize key_len,
                         const char *ifname,
                         const char *current_mac_address,
                         const char *generate_mac_address_mask)
{
	GChecksum *sum;
	guint32 tmp;
	guint8 digest[32];
	gsize len = sizeof (digest);
	struct ether_addr bin_addr;
	guint8 stable_type_uint8;

	nm_assert (stable_id);
	nm_assert (secret_key);

	sum = g_checksum_new (G_CHECKSUM_SHA256);
	if (!sum)
		return NULL;

	key_len = MIN (key_len, G_MAXUINT32);

	nm_assert (stable_type < (NMUtilsStableType) 255);
	stable_type_uint8 = stable_type;
	g_checksum_update (sum, (const guchar *) &stable_type_uint8, sizeof (stable_type_uint8));

	tmp = htonl ((guint32) key_len);
	g_checksum_update (sum, (const guchar *) &tmp, sizeof (tmp));
	g_checksum_update (sum, (const guchar *) secret_key, key_len);
	g_checksum_update (sum, (const guchar *) (ifname ?: ""), ifname ? (strlen (ifname) + 1) : 1);
	g_checksum_update (sum, (const guchar *) stable_id, strlen (stable_id) + 1);

	g_checksum_get_digest (sum, digest, &len);
	g_checksum_free (sum);

	g_return_val_if_fail (len == 32, NULL);

	memcpy (&bin_addr, digest, ETH_ALEN);
	_hw_addr_eth_complete (&bin_addr, current_mac_address, generate_mac_address_mask);
	return nm_utils_hwaddr_ntoa (&bin_addr, ETH_ALEN);
}

char *
nm_utils_hw_addr_gen_stable_eth_impl (NMUtilsStableType stable_type,
                                      const char *stable_id,
                                      const guint8 *secret_key,
                                      gsize key_len,
                                      const char *ifname,
                                      const char *current_mac_address,
                                      const char *generate_mac_address_mask)
{
	return _hw_addr_gen_stable_eth (stable_type, stable_id, secret_key, key_len, ifname, current_mac_address, generate_mac_address_mask);
}

char *
nm_utils_hw_addr_gen_stable_eth (NMUtilsStableType stable_type,
                                 const char *stable_id,
                                 const char *ifname,
                                 const char *current_mac_address,
                                 const char *generate_mac_address_mask)
{
	gs_free guint8 *secret_key = NULL;
	gsize key_len = 0;

	g_return_val_if_fail (stable_id, NULL);

	secret_key = nm_utils_secret_key_read (&key_len, NULL);
	if (!secret_key)
		return NULL;

	return _hw_addr_gen_stable_eth (stable_type,
	                                stable_id,
	                                secret_key,
	                                key_len,
	                                ifname,
	                                current_mac_address,
	                                generate_mac_address_mask);
}

/*****************************************************************************/

/**
 * nm_utils_setpgid:
 * @unused: unused
 *
 * This can be passed as a child setup function to the g_spawn*() family
 * of functions, to ensure that the child is in its own process group
 * (and thus, in some situations, will not be killed when NetworkManager
 * is killed).
 */
void
nm_utils_setpgid (gpointer unused G_GNUC_UNUSED)
{
	pid_t pid;

	pid = getpid ();
	setpgid (pid, pid);
}

/**
 * nm_utils_g_value_set_strv:
 * @value: a #GValue, initialized to store a #G_TYPE_STRV
 * @strings: a #GPtrArray of strings
 *
 * Converts @strings to a #GStrv and stores it in @value.
 */
void
nm_utils_g_value_set_strv (GValue *value, GPtrArray *strings)
{
	char **strv;
	int i;

	strv = g_new (char *, strings->len + 1);
	for (i = 0; i < strings->len; i++)
		strv[i] = g_strdup (strings->pdata[i]);
	strv[i] = NULL;

	g_value_take_boxed (value, strv);
}

/*****************************************************************************/

static gboolean
debug_key_matches (const gchar *key,
                   const gchar *token,
                   guint        length)
{
	/* may not call GLib functions: see note in g_parse_debug_string() */
	for (; length; length--, key++, token++) {
		char k = (*key   == '_') ? '-' : g_ascii_tolower (*key  );
		char t = (*token == '_') ? '-' : g_ascii_tolower (*token);

		if (k != t)
			return FALSE;
	}

	return *key == '\0';
}

/**
 * nm_utils_parse_debug_string:
 * @string: the string to parse
 * @keys: the debug keys
 * @nkeys: number of entires in @keys
 *
 * Similar to g_parse_debug_string(), but does not special
 * case "help" or "all".
 *
 * Returns: the flags
 */
guint
nm_utils_parse_debug_string (const char *string,
                             const GDebugKey *keys,
                             guint nkeys)
{
	guint i;
	guint result = 0;
	const char *q;

	if (string == NULL)
		return 0;

	while (*string) {
		q = strpbrk (string, ":;, \t");
		if (!q)
			q = string + strlen (string);

		for (i = 0; i < nkeys; i++) {
			if (debug_key_matches (keys[i].key, string, q - string))
				result |= keys[i].value;
		}

		string = q;
		if (*string)
			string++;
	}

	return result;
}

/*****************************************************************************/

void
nm_utils_ifname_cpy (char *dst, const char *name)
{
	g_return_if_fail (dst);
	g_return_if_fail (name && name[0]);

	nm_assert (nm_utils_is_valid_iface_name (name, NULL));

	if (g_strlcpy (dst, name, IFNAMSIZ) >= IFNAMSIZ)
		g_return_if_reached ();
}

/*****************************************************************************/

#define IPV4LL_NETWORK (htonl (0xA9FE0000L))
#define IPV4LL_NETMASK (htonl (0xFFFF0000L))

gboolean
nm_utils_ip4_address_is_link_local (in_addr_t addr)
{
	return (addr & IPV4LL_NETMASK) == IPV4LL_NETWORK;
}

/*****************************************************************************/

/**
 * Takes a pair @timestamp and @duration, and returns the remaining duration based
 * on the new timestamp @now.
 */
guint32
nm_utils_lifetime_rebase_relative_time_on_now (guint32 timestamp,
                                               guint32 duration,
                                               gint32 now)
{
	gint64 t;

	nm_assert (now >= 0);

	if (duration == NM_PLATFORM_LIFETIME_PERMANENT)
		return NM_PLATFORM_LIFETIME_PERMANENT;

	if (timestamp == 0) {
		/* if the @timestamp is zero, assume it was just left unset and that the relative
		 * @duration starts counting from @now. This is convenient to construct an address
		 * and print it in nm_platform_ip4_address_to_string().
		 *
		 * In general it does not make sense to set the @duration without anchoring at
		 * @timestamp because you don't know the absolute expiration time when looking
		 * at the address at a later moment. */
		timestamp = now;
	}

	/* For timestamp > now, just accept it and calculate the expected(?) result. */
	t = (gint64) timestamp + (gint64) duration - (gint64) now;

	if (t <= 0)
		return 0;
	if (t >= NM_PLATFORM_LIFETIME_PERMANENT)
		return NM_PLATFORM_LIFETIME_PERMANENT - 1;
	return t;
}

gboolean
nm_utils_lifetime_get (guint32 timestamp,
                       guint32 lifetime,
                       guint32 preferred,
                       gint32 now,
                       guint32 *out_lifetime,
                       guint32 *out_preferred)
{
	guint32 t_lifetime, t_preferred;

	nm_assert (now >= 0);

	if (timestamp == 0 && lifetime == 0) {
		/* We treat lifetime==0 && timestamp == 0 addresses as permanent addresses to allow easy
		 * creation of such addresses (without requiring to set the lifetime fields to
		 * NM_PLATFORM_LIFETIME_PERMANENT). The real lifetime==0 addresses (E.g. DHCP6 telling us
		 * to drop an address will have timestamp set.
		 */
		*out_lifetime = NM_PLATFORM_LIFETIME_PERMANENT;
		*out_preferred = NM_PLATFORM_LIFETIME_PERMANENT;
		g_return_val_if_fail (preferred == 0, TRUE);
	} else {
		if (now <= 0)
			now = nm_utils_get_monotonic_timestamp_s ();
		t_lifetime = nm_utils_lifetime_rebase_relative_time_on_now (timestamp, lifetime, now);
		if (!t_lifetime) {
			*out_lifetime = 0;
			*out_preferred = 0;
			return FALSE;
		}
		t_preferred = nm_utils_lifetime_rebase_relative_time_on_now (timestamp, preferred, now);

		*out_lifetime = t_lifetime;
		*out_preferred = MIN (t_preferred, t_lifetime);

		/* Assert that non-permanent addresses have a (positive) @timestamp. nm_utils_lifetime_rebase_relative_time_on_now()
		 * treats addresses with timestamp 0 as *now*. Addresses passed to _address_get_lifetime() always
		 * should have a valid @timestamp, otherwise on every re-sync, their lifetime will be extended anew.
		 */
		g_return_val_if_fail (   timestamp != 0
		                      || (   lifetime  == NM_PLATFORM_LIFETIME_PERMANENT
		                          && preferred == NM_PLATFORM_LIFETIME_PERMANENT), TRUE);
		g_return_val_if_fail (t_preferred <= t_lifetime, TRUE);
	}
	return TRUE;
}

const char *
nm_utils_dnsmasq_status_to_string (int status, char *dest, gsize size)
{
	const char *msg;

	nm_utils_to_string_buffer_init (&dest, &size);

	if (status == 0)
		msg = "Success";
	else if (status == 1)
		msg = "Configuration problem";
	else if (status == 2)
		msg = "Network access problem (address in use, permissions)";
	else if (status == 3)
		msg = "Filesystem problem (missing file/directory, permissions)";
	else if (status == 4)
		msg = "Memory allocation failure";
	else if (status == 5)
		msg = "Other problem";
	else if (status >= 11) {
		g_snprintf (dest, size, "Lease script failed with error %d", status - 10);
		return dest;
	}
	else
		msg = "Unknown problem";

	g_snprintf (dest, size, "%s (%d)", msg, status);
	return dest;
}

/**
 * nm_utils_get_reverse_dns_domains_ip4:
 * @addr: IP address in network order
 * @plen: prefix length
 * @domains: array for results
 *
 * Creates reverse DNS domains for the given address and prefix length, and
 * append them to @domains.
 */
void
nm_utils_get_reverse_dns_domains_ip4 (guint32 addr, guint8 plen, GPtrArray *domains)
{
	guint32 ip, ip2, mask;
	guchar *p;
	guint octets;
	guint i;
	gsize len0, len;
	char *str, *s;

	g_return_if_fail (domains);
	g_return_if_fail (plen <= 32);

	if (!plen)
		return;

	octets = (plen - 1) / 8 + 1;
	ip = ntohl (addr);
	mask = 0xFFFFFFFF << (32 - plen);
	ip &= mask;
	ip2 = ip;

	len0 = NM_STRLEN ("in-addr.arpa") + (4 * octets) + 1;
	while ((ip2 & mask) == ip) {
		addr = htonl (ip2);
		p = (guchar *) &addr;

		len = len0;
		str = s = g_malloc (len);
		for (i = octets; i > 0; i--)
			nm_utils_strbuf_append (&s, &len, "%u.", p[i - 1] & 0xff);
		nm_utils_strbuf_append_str (&s, &len, "in-addr.arpa");

		g_ptr_array_add (domains, str);

		ip2 += 1 << ((32 - plen) & ~7);
	}
}

/**
 * nm_utils_get_reverse_dns_domains_ip6:
 * @addr: IPv6 address
 * @plen: prefix length
 * @domains: array for results
 *
 * Creates reverse DNS domains for the given address and prefix length, and
 * append them to @domains.
 */
void
nm_utils_get_reverse_dns_domains_ip6 (const struct in6_addr *ip, guint8 plen, GPtrArray *domains)
{
	struct in6_addr addr;
	guint nibbles, bits, entries;
	int i, j;
	gsize len0, len;
	char *str, *s;

	g_return_if_fail (domains);
	g_return_if_fail (plen <= 128);

	if (!plen)
		return;

	memcpy (&addr, ip, sizeof (struct in6_addr));
	nm_utils_ip6_address_clear_host_address (&addr, &addr, plen);

	/* Number of nibbles to include in domains */
	nibbles = (plen - 1) / 4 + 1;
	/* Prefix length in nibble */
	bits = plen - ((plen - 1) / 4 * 4);
	/* Number of domains */
	entries = 1 << (4 - bits);

	len0 = NM_STRLEN ("ip6.arpa") + (2 * nibbles) + 1;

#define N_SHIFT(x) ((x) % 2 ? 0 : 4)

	for (i = 0; i < entries; i++) {
		len = len0;
		str = s = g_malloc (len);

		for (j = nibbles - 1; j >= 0; j--)
			nm_utils_strbuf_append (&s,
			                        &len,
			                        "%x.",
			                        (addr.s6_addr[j / 2] >> N_SHIFT (j)) & 0xf);
		nm_utils_strbuf_append_str (&s, &len, "ip6.arpa");

		g_ptr_array_add (domains, str);

		addr.s6_addr[(nibbles - 1) / 2] += 1 << N_SHIFT (nibbles - 1);
	}

#undef N_SHIFT
}

/**
 * Copied from GLib's g_file_set_contents() et al., but allows
 * specifying a mode for the new file.
 */
gboolean
nm_utils_file_set_contents (const gchar *filename,
                            const gchar *contents,
                            gssize length,
                            mode_t mode,
                            GError **error)
{
	gs_free char *tmp_name = NULL;
	struct stat statbuf;
	int errsv;
	gssize s;
	int fd;

	g_return_val_if_fail (filename, FALSE);
	g_return_val_if_fail (contents || !length, FALSE);
	g_return_val_if_fail (!error || !*error, FALSE);
	g_return_val_if_fail (length >= -1, FALSE);

	if (length == -1)
		length = strlen (contents);

	tmp_name = g_strdup_printf ("%s.XXXXXX", filename);
	fd = g_mkstemp_full (tmp_name, O_RDWR, mode);
	if (fd < 0) {
		errsv = errno;
		g_set_error (error,
		             G_FILE_ERROR,
		             g_file_error_from_errno (errsv),
		             "failed to create file %s: %s",
		             tmp_name,
		             g_strerror (errsv));
		return FALSE;
	}

	while (length > 0) {
		s = write (fd, contents, length);
		if (s < 0) {
			errsv = errno;
			if (errsv == EINTR)
				continue;

			close (fd);
			unlink (tmp_name);

			g_set_error (error,
			             G_FILE_ERROR,
			             g_file_error_from_errno (errsv),
			             "failed to write to file %s: %s",
			             tmp_name,
			             g_strerror (errsv));
			return FALSE;
		}

		g_assert (s <= length);

		contents += s;
		length -= s;
	}

	/* If the final destination exists and is > 0 bytes, we want to sync the
	 * newly written file to ensure the data is on disk when we rename over
	 * the destination. Otherwise if we get a system crash we can lose both
	 * the new and the old file on some filesystems. (I.E. those that don't
	 * guarantee the data is written to the disk before the metadata.)
	 */
	if (   lstat (filename, &statbuf) == 0
	    && statbuf.st_size > 0
	    && fsync (fd) != 0) {
		errsv = errno;

		close (fd);
		unlink (tmp_name);

		g_set_error (error,
		             G_FILE_ERROR,
		             g_file_error_from_errno (errsv),
		             "failed to fsync %s: %s",
		             tmp_name,
		             g_strerror (errsv));
		return FALSE;
	}

	close (fd);

	if (rename (tmp_name, filename)) {
		errsv = errno;
		unlink (tmp_name);
		g_set_error (error,
		             G_FILE_ERROR,
		             g_file_error_from_errno (errsv),
		             "failed to rename %s to %s: %s",
		             tmp_name,
		             filename,
		             g_strerror (errsv));
		return FALSE;
	}

	return TRUE;
}

struct plugin_info {
	char *path;
	struct stat st;
};

static gint
read_device_factory_paths_sort_fcn (gconstpointer a, gconstpointer b)
{
	const struct plugin_info *da = a;
	const struct plugin_info *db = b;
	time_t ta, tb;

	ta = MAX (da->st.st_mtime, da->st.st_ctime);
	tb = MAX (db->st.st_mtime, db->st.st_ctime);

	if (ta < tb)
		return 1;
	if (ta > tb)
		return -1;
	return 0;
}

gboolean
nm_utils_validate_plugin (const char *path, struct stat *st, GError **error)
{
	g_return_val_if_fail (path, FALSE);
	g_return_val_if_fail (st, FALSE);
	g_return_val_if_fail (!error || !*error, FALSE);

	if (!S_ISREG (st->st_mode)) {
		g_set_error_literal (error,
		                     NM_UTILS_ERROR, NM_UTILS_ERROR_UNKNOWN,
		                     "not a regular file");
		return FALSE;
	}

	if (st->st_uid != 0) {
		g_set_error_literal (error,
		                     NM_UTILS_ERROR, NM_UTILS_ERROR_UNKNOWN,
		                     "file has invalid owner (should be root)");
		return FALSE;
	}

	if (st->st_mode & (S_IWGRP | S_IWOTH | S_ISUID)) {
		g_set_error_literal (error,
		                     NM_UTILS_ERROR, NM_UTILS_ERROR_UNKNOWN,
		                     "file has invalid permissions");
		return FALSE;
	}

	return TRUE;
}

char **
nm_utils_read_plugin_paths (const char *dirname, const char *prefix)
{
	GDir *dir;
	GError *error = NULL;
	const char *item;
	GArray *paths;
	char **result;
	guint i;

	g_return_val_if_fail (dirname, NULL);
	g_return_val_if_fail (prefix, NULL);

	dir = g_dir_open (dirname, 0, &error);
	if (!dir) {
		nm_log_warn (LOGD_CORE, "device plugin: failed to open directory %s: %s",
		             dirname,
		             error->message);
		g_clear_error (&error);
		return NULL;
	}

	paths = g_array_new (FALSE, FALSE, sizeof (struct plugin_info));

	while ((item = g_dir_read_name (dir))) {
		int errsv;
		struct plugin_info data;

		if (!g_str_has_prefix (item, prefix))
			continue;
		if (g_str_has_suffix (item, ".la"))
			continue;

		data.path = g_build_filename (dirname, item, NULL);

		if (stat (data.path, &data.st) != 0) {
			errsv = errno;
			nm_log_warn (LOGD_CORE,
			             "plugin: skip invalid file %s (error during stat: %s)",
			             data.path, strerror (errsv));
			goto skip;
		}

		if (!nm_utils_validate_plugin (data.path, &data.st, &error)) {
			nm_log_warn (LOGD_CORE,
			             "plugin: skip invalid file %s: %s",
			             data.path, error->message);
			g_clear_error (&error);
			goto skip;
		}

		g_array_append_val (paths, data);
		continue;
skip:
		g_free (data.path);
	}
	g_dir_close (dir);

	/* sort filenames by modification time. */
	g_array_sort (paths, read_device_factory_paths_sort_fcn);

	result = g_new (char *, paths->len + 1);
	for (i = 0; i < paths->len; i++)
		result[i] = g_array_index (paths, struct plugin_info, i).path;
	result[i] = NULL;

	g_array_free (paths, TRUE);
	return result;
}

