merge: consolidate searching for helper programs (bgo #734131)

https://bugzilla.gnome.org/show_bug.cgi?id=734131

15 files changed, 149 insertions, 241 deletions

diff --git a/configure.ac b/configure.ac
index 23898c3bbb..4add1fd65e 100644
--- a/configure.ac
+++ b/configure.ac
@@ -643,10 +643,16 @@ if test "$with_dhclient" = "no" -a "$with_dhcpcd" = "no"; then
 fi
 # Add substitutions
 if test "$with_dhclient" != "no"; then
+	AC_DEFINE(WITH_DHCLIENT, TRUE, [Define if you have dhclient])
 	AC_SUBST(DHCLIENT_PATH, $with_dhclient)
+else
+	AC_DEFINE(WITH_DHCLIENT, FALSE, [Define if you have dhclient])
 fi
 if test "$with_dhcpcd" != "no"; then
+	AC_DEFINE(WITH_DHCPCD, TRUE, [Define if you have dhcpcd])
 	AC_SUBST(DHCPCD_PATH, $with_dhcpcd)
+else
+	AC_DEFINE(WITH_DHCPCD, FALSE, [Define if you have dhcpcd])
 fi
 
 # resolvconf and netconfig support
diff --git a/src/Makefile.am b/src/Makefile.am
index 1d9ba94435..ae4f26768e 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -40,6 +40,7 @@ AM_CPPFLAGS =				\
 	-I$(top_srcdir)/libnm-core	\
 	-I$(top_builddir)/libnm-core	\
 	-I$(top_srcdir)/callouts	\
+	-DPREFIX=\"$(prefix)\"          \
 	-DG_LOG_DOMAIN=\""NetworkManager"\" \
 	-DNETWORKMANAGER_COMPILATION	\
 	-DNM_VERSION_MAX_ALLOWED=NM_VERSION_NEXT_STABLE
diff --git a/src/NetworkManagerUtils.c b/src/NetworkManagerUtils.c
index 525154009e..b665984fe0 100644
--- a/src/NetworkManagerUtils.c
+++ b/src/NetworkManagerUtils.c
@@ -589,6 +589,56 @@ out:
 #undef LOG_NAME_FMT
 #undef LOG_NAME_ARGS
 
+/**
+ * nm_utils_find_helper:
+ * @progname: the helper program name, like "iptables"
+ * @try_first: a custom path to try first before searching
+ * @error: on failure, a "not found" error using @error_domain and @error_code
+ *
+ * Searches for the @progname in common system paths.
+ *
+ * Returns: the full path to the helper, if found, or %NULL if not found.
+ */
+const char *
+nm_utils_find_helper (const char *progname,
+                      const char *try_first,
+                      GError **error)
+{
+	static const char *paths[] = {
+		PREFIX "/sbin/",
+		PREFIX "/bin/",
+		"/sbin/",
+		"/usr/sbin/",
+		"/usr/local/sbin/",
+		"/usr/bin/",
+		"/usr/local/bin/",
+	};
+	guint i;
+	GString *tmp;
+	const char *ret;
+
+	if (error)
+		g_return_val_if_fail (*error == NULL, NULL);
+
+	if (try_first && try_first[0] && g_file_test (try_first, G_FILE_TEST_EXISTS))
+		return g_intern_string (try_first);
+
+	tmp = g_string_sized_new (50);
+	for (i = 0; i < G_N_ELEMENTS (paths); i++) {
+		g_string_append_printf (tmp, "%s%s", paths[i], progname);
+		if (g_file_test (tmp->str, G_FILE_TEST_EXISTS)) {
+			ret = g_intern_string (tmp->str);
+			g_string_free (tmp, TRUE);
+			return ret;
+		}
+		g_string_set_size (tmp, 0);
+	}
+	g_string_free (tmp, TRUE);
+
+	g_set_error (error, G_IO_ERROR, G_IO_ERROR_NOT_FOUND, "Could not find %s binary", progname);
+	return NULL;
+}
+
 /******************************************************************************************/
 
 gboolean
diff --git a/src/NetworkManagerUtils.h b/src/NetworkManagerUtils.h
index c1c65faa06..9a31053326 100644
--- a/src/NetworkManagerUtils.h
+++ b/src/NetworkManagerUtils.h
@@ -62,6 +62,10 @@ gboolean nm_utils_kill_child_sync (pid_t pid, int sig, guint64 log_domain, const
                                    int *child_status, guint32 wait_before_kill_msec,
                                    guint32 sleep_duration_msec);
 
+const char *nm_utils_find_helper (const char *progname,
+                                  const char *try_first,
+                                  GError **error);
+
 gboolean nm_match_spec_string (const GSList *specs, const char *string);
 gboolean nm_match_spec_hwaddr (const GSList *specs, const char *hwaddr);
 gboolean nm_match_spec_s390_subchannels (const GSList *specs, const char *subchannels);
diff --git a/src/devices/nm-device.c b/src/devices/nm-device.c
index 18b0ad21c7..8bcdadf518 100644
--- a/src/devices/nm-device.c
+++ b/src/devices/nm-device.c
@@ -2508,27 +2508,17 @@ static NMActStageReturn
 aipd_start (NMDevice *self, NMDeviceStateReason *reason)
 {
 	NMDevicePrivate *priv = NM_DEVICE_GET_PRIVATE (self);
-	char *argv[6], *cmdline;
-	const char **aipd_binary = NULL;
-	static const char *aipd_paths[] = {
-		"/usr/sbin/avahi-autoipd",
-		"/usr/local/sbin/avahi-autoipd",
-		NULL
-	};
+	const char *argv[6];
+	char *cmdline;
+	const char *aipd_binary;
 	int i = 0;
 	GError *error = NULL;
 
 	aipd_cleanup (self);
 
 	/* Find avahi-autoipd */
-	aipd_binary = aipd_paths;
-	while (*aipd_binary != NULL) {
-		if (g_file_test (*aipd_binary, G_FILE_TEST_EXISTS))
-			break;
-		aipd_binary++;
-	}
-
-	if (!*aipd_binary) {
+	aipd_binary = nm_utils_find_helper ("avahi-autoipd", NULL, NULL);
+	if (!aipd_binary) {
 		_LOGW (LOGD_DEVICE | LOGD_AUTOIP4,
 		       "Activation: Stage 3 of 5 (IP Configure Start) failed"
 		       " to start avahi-autoipd: not found");
@@ -2536,20 +2526,20 @@ aipd_start (NMDevice *self, NMDeviceStateReason *reason)
 		return NM_ACT_STAGE_RETURN_FAILURE;
 	}
 
-	argv[i++] = (char *) (*aipd_binary);
+	argv[i++] = aipd_binary;
 	argv[i++] = "--script";
-	argv[i++] = (char *) nm_device_autoipd_helper_path;
+	argv[i++] = nm_device_autoipd_helper_path;
 
 	if (nm_logging_enabled (LOGL_DEBUG, LOGD_AUTOIP4))
 		argv[i++] = "--debug";
-	argv[i++] = (char *) nm_device_get_ip_iface (self);
+	argv[i++] = nm_device_get_ip_iface (self);
 	argv[i++] = NULL;
 
-	cmdline = g_strjoinv (" ", argv);
+	cmdline = g_strjoinv (" ", (char **) argv);
 	_LOGD (LOGD_AUTOIP4, "running: %s", cmdline);
 	g_free (cmdline);
 
-	if (!g_spawn_async ("/", argv, NULL, G_SPAWN_DO_NOT_REAP_CHILD,
+	if (!g_spawn_async ("/", (char **) argv, NULL, G_SPAWN_DO_NOT_REAP_CHILD,
 	                    &aipd_child_setup, NULL, &(priv->aipd_pid), &error)) {
 		_LOGW (LOGD_DEVICE | LOGD_AUTOIP4,
 		       "Activation: Stage 3 of 5 (IP Configure Start) failed"
@@ -4520,7 +4510,7 @@ start_sharing (NMDevice *self, NMIP4Config *config)
 static void
 send_arps (NMDevice *self, const char *mode_arg)
 {
-	const char *argv[] = { "/sbin/arping", mode_arg, "-q", "-I", nm_device_get_ip_iface (self), "-c", "1", NULL, NULL };
+	const char *argv[] = { NULL, mode_arg, "-q", "-I", nm_device_get_ip_iface (self), "-c", "1", NULL, NULL };
 	int ip_arg = G_N_ELEMENTS (argv) - 2;
 	NMConnection *connection;
 	NMSettingIP4Config *s_ip4;
@@ -4536,6 +4526,14 @@ send_arps (NMDevice *self, const char *mode_arg)
 	if (!s_ip4)
 		return;
 	num = nm_setting_ip4_config_get_num_addresses (s_ip4);
+	if (num == 0)
+		return;
+
+	argv[0] = nm_utils_find_helper ("arping", NULL, NULL);
+	if (!argv[0]) {
+		_LOGW (LOGD_DEVICE | LOGD_IP4, "arping could not be found; no ARPs will be sent");
+		return;
+	}
 
 	for (i = 0; i < num; i++) {
 		gs_free char *tmp_str = NULL;
diff --git a/src/devices/team/nm-device-team.c b/src/devices/team/nm-device-team.c
index b524ba7efd..40055961bd 100644
--- a/src/devices/team/nm-device-team.c
+++ b/src/devices/team/nm-device-team.c
@@ -422,12 +422,7 @@ teamd_start (NMDevice *device, NMSettingTeam *s_team)
 	const char *iface = nm_device_get_ip_iface (device);
 	char *tmp_str = NULL;
 	const char *config;
-	const char **teamd_binary = NULL;
-	static const char *teamd_paths[] = {
-		"/usr/bin/teamd",
-		"/usr/local/bin/teamd",
-		NULL
-	};
+	const char *teamd_binary;
 	GPtrArray *argv;
 	GError *error = NULL;
 	gboolean ret;
@@ -443,21 +438,15 @@ teamd_start (NMDevice *device, NMSettingTeam *s_team)
 		return TRUE;
 	}
 
-	teamd_binary = teamd_paths;
-	while (*teamd_binary != NULL) {
-		if (g_file_test (*teamd_binary, G_FILE_TEST_EXISTS))
-			break;
-		teamd_binary++;
-	}
-
-	if (!*teamd_binary) {
+	teamd_binary = nm_utils_find_helper ("teamd", NULL, NULL);
+	if (!teamd_binary) {
 		_LOGW (LOGD_TEAM, "Activation: (team) failed to start teamd: teamd binary not found");
 		return FALSE;
 	}
 
 	/* Kill teamd for same named device first if it is there */
 	argv = g_ptr_array_new ();
-	g_ptr_array_add (argv, (gpointer) *teamd_binary);
+	g_ptr_array_add (argv, (gpointer) teamd_binary);
 	g_ptr_array_add (argv, (gpointer) "-k");
 	g_ptr_array_add (argv, (gpointer) "-t");
 	g_ptr_array_add (argv, (gpointer) iface);
@@ -472,7 +461,7 @@ teamd_start (NMDevice *device, NMSettingTeam *s_team)
 
 	/* Start teamd now */
 	argv = g_ptr_array_new ();
-	g_ptr_array_add (argv, (gpointer) *teamd_binary);
+	g_ptr_array_add (argv, (gpointer) teamd_binary);
 	g_ptr_array_add (argv, (gpointer) "-o");
 	g_ptr_array_add (argv, (gpointer) "-n");
 	g_ptr_array_add (argv, (gpointer) "-U");
diff --git a/src/dhcp-manager/nm-dhcp-dhclient.c b/src/dhcp-manager/nm-dhcp-dhclient.c
index d5ea6a5486..74b416a7bb 100644
--- a/src/dhcp-manager/nm-dhcp-dhclient.c
+++ b/src/dhcp-manager/nm-dhcp-dhclient.c
@@ -42,13 +42,13 @@
 #include "nm-dhcp-dhclient-utils.h"
 #include "nm-dhcp-manager.h"
 #include "nm-posix-signals.h"
+#include "NetworkManagerUtils.h"
 
 G_DEFINE_TYPE (NMDhcpDhclient, nm_dhcp_dhclient, NM_TYPE_DHCP_CLIENT)
 
 #define NM_DHCP_DHCLIENT_GET_PRIVATE(o) (G_TYPE_INSTANCE_GET_PRIVATE ((o), NM_TYPE_DHCP_DHCLIENT, NMDhcpDhclientPrivate))
 
 typedef struct {
-	const char *path;
 	char *conf_file;
 	const char *def_leasefile;
 	char *lease_file;
@@ -56,27 +56,13 @@ typedef struct {
 } NMDhcpDhclientPrivate;
 
 const char *
-nm_dhcp_dhclient_get_path (const char *try_first)
+nm_dhcp_dhclient_get_path (void)
 {
-	static const char *dhclient_paths[] = {
-		"/sbin/dhclient",
-		"/usr/sbin/dhclient",
-		"/usr/pkg/sbin/dhclient",
-		"/usr/local/sbin/dhclient",
-		NULL
-	};
-	const char **path = dhclient_paths;
-
-	if (strlen (try_first) && g_file_test (try_first, G_FILE_TEST_EXISTS))
-		return try_first;
-
-	while (*path != NULL) {
-		if (g_file_test (*path, G_FILE_TEST_EXISTS))
-			break;
-		path++;
-	}
+	const char *path = NULL;
 
-	return *path;
+	if (WITH_DHCLIENT)
+		path = nm_utils_find_helper ("dhclient", DHCLIENT_PATH, NULL);
+	return path;
 }
 
 /**
@@ -335,7 +321,7 @@ dhclient_start (NMDhcpClient *client,
 	GPtrArray *argv = NULL;
 	pid_t pid;
 	GError *error = NULL;
-	const char *iface, *uuid, *system_bus_address;
+	const char *iface, *uuid, *system_bus_address, *dhclient_path = NULL;
 	char *binary_name, *cmd_str, *pid_file = NULL, *system_bus_address_env = NULL;
 	gboolean ipv6, success;
 	guint log_domain;
@@ -349,8 +335,9 @@ dhclient_start (NMDhcpClient *client,
 
 	log_domain = ipv6 ? LOGD_DHCP6 : LOGD_DHCP4;
 
-	if (!g_file_test (priv->path, G_FILE_TEST_EXISTS)) {
-		nm_log_warn (log_domain, "%s does not exist.", priv->path);
+	dhclient_path = nm_dhcp_dhclient_get_path ();
+	if (!dhclient_path) {
+		nm_log_warn (log_domain, "dhclient could not be found");
 		return FALSE;
 	}
 
@@ -359,7 +346,7 @@ dhclient_start (NMDhcpClient *client,
 		                        iface);
 
 	/* Kill any existing dhclient from the pidfile */
-	binary_name = g_path_get_basename (priv->path);
+	binary_name = g_path_get_basename (dhclient_path);
 	nm_dhcp_client_stop_existing (pid_file, binary_name);
 	g_free (binary_name);
 
@@ -411,7 +398,7 @@ dhclient_start (NMDhcpClient *client,
 	}
 
 	argv = g_ptr_array_new ();
-	g_ptr_array_add (argv, (gpointer) priv->path);
+	g_ptr_array_add (argv, (gpointer) dhclient_path);
 
 	g_ptr_array_add (argv, (gpointer) "-d");
 
@@ -608,8 +595,6 @@ nm_dhcp_dhclient_init (NMDhcpDhclient *self)
 	NMDhcpDhclientPrivate *priv = NM_DHCP_DHCLIENT_GET_PRIVATE (self);
 	const char **iter = &def_leasefiles[0];
 
-	priv->path = nm_dhcp_dhclient_get_path (DHCLIENT_PATH);
-
 	while (iter && *iter) {
 		if (g_file_test (*iter, G_FILE_TEST_EXISTS)) {
 			priv->def_leasefile = *iter;
diff --git a/src/dhcp-manager/nm-dhcp-dhclient.h b/src/dhcp-manager/nm-dhcp-dhclient.h
index 8192a599b1..6c58826241 100644
--- a/src/dhcp-manager/nm-dhcp-dhclient.h
+++ b/src/dhcp-manager/nm-dhcp-dhclient.h
@@ -45,7 +45,7 @@ GSList *nm_dhcp_dhclient_get_lease_ip_configs (const char *iface,
                                                const char *uuid,
                                                gboolean ipv6);
 
-const char *nm_dhcp_dhclient_get_path (const char *try_first);
+const char *nm_dhcp_dhclient_get_path (void);
 
 #endif /* __NETWORKMANAGER_DHCP_DHCLIENT_H__ */
 
diff --git a/src/dhcp-manager/nm-dhcp-dhcpcd.c b/src/dhcp-manager/nm-dhcp-dhcpcd.c
index 8345034b84..98b54b10f4 100644
--- a/src/dhcp-manager/nm-dhcp-dhcpcd.c
+++ b/src/dhcp-manager/nm-dhcp-dhcpcd.c
@@ -37,38 +37,24 @@
 #include "nm-utils.h"
 #include "nm-logging.h"
 #include "nm-posix-signals.h"
+#include "NetworkManagerUtils.h"
 
 G_DEFINE_TYPE (NMDhcpDhcpcd, nm_dhcp_dhcpcd, NM_TYPE_DHCP_CLIENT)
 
 #define NM_DHCP_DHCPCD_GET_PRIVATE(o) (G_TYPE_INSTANCE_GET_PRIVATE ((o), NM_TYPE_DHCP_DHCPCD, NMDhcpDhcpcdPrivate))
 
 typedef struct {
-	const char *path;
 	char *pid_file;
 } NMDhcpDhcpcdPrivate;
 
 const char *
-nm_dhcp_dhcpcd_get_path (const char *try_first)
+nm_dhcp_dhcpcd_get_path (void)
 {
-	static const char *dhcpcd_paths[] = {
-		"/sbin/dhcpcd",
-		"/usr/sbin/dhcpcd",
-		"/usr/pkg/sbin/dhcpcd",
-		"/usr/local/sbin/dhcpcd",
-		NULL
-	};
-	const char **path = dhcpcd_paths;
-
-	if (strlen (try_first) && g_file_test (try_first, G_FILE_TEST_EXISTS))
-		return try_first;
-
-	while (*path != NULL) {
-		if (g_file_test (*path, G_FILE_TEST_EXISTS))
-			break;
-		path++;
-	}
+	const char *path = NULL;
 
-	return *path;
+	if (WITH_DHCPCD)
+		path = nm_utils_find_helper ("dhcpcd", DHCPCD_PATH, NULL);
+	return path;
 }
 
 static void
@@ -96,7 +82,7 @@ ip4_start (NMDhcpClient *client,
 	pid_t pid = -1;
 	GError *error = NULL;
 	char *pid_contents = NULL, *binary_name, *cmd_str;
-	const char *iface;
+	const char *iface, *dhcpcd_path = NULL;
 
 	g_return_val_if_fail (priv->pid_file == NULL, FALSE);
 
@@ -107,18 +93,19 @@ ip4_start (NMDhcpClient *client,
 	 */
 	priv->pid_file = g_strdup_printf (RUNDIR "/dhcpcd-%s.pid", iface);
 
-	if (!g_file_test (priv->path, G_FILE_TEST_EXISTS)) {
-		nm_log_warn (LOGD_DHCP4, "%s does not exist.", priv->path);
+	dhcpcd_path = nm_dhcp_dhcpcd_get_path ();
+	if (!dhcpcd_path) {
+		nm_log_warn (LOGD_DHCP4, "dhcpcd could not be found");
 		return FALSE;
 	}
 
 	/* Kill any existing dhcpcd from the pidfile */
-	binary_name = g_path_get_basename (priv->path);
+	binary_name = g_path_get_basename (dhcpcd_path);
 	nm_dhcp_client_stop_existing (priv->pid_file, binary_name);
 	g_free (binary_name);
 
 	argv = g_ptr_array_new ();
-	g_ptr_array_add (argv, (gpointer) priv->path);
+	g_ptr_array_add (argv, (gpointer) dhcpcd_path);
 
 	g_ptr_array_add (argv, (gpointer) "-B");	/* Don't background on lease (disable fork()) */
 
@@ -202,9 +189,6 @@ stop (NMDhcpClient *client, gboolean release, const GByteArray *duid)
 static void
 nm_dhcp_dhcpcd_init (NMDhcpDhcpcd *self)
 {
-	NMDhcpDhcpcdPrivate *priv = NM_DHCP_DHCPCD_GET_PRIVATE (self);
-
-	priv->path = nm_dhcp_dhcpcd_get_path (DHCPCD_PATH);
 }
 
 static void
diff --git a/src/dhcp-manager/nm-dhcp-dhcpcd.h b/src/dhcp-manager/nm-dhcp-dhcpcd.h
index 6dfe0dda97..4e3502ab5a 100644
--- a/src/dhcp-manager/nm-dhcp-dhcpcd.h
+++ b/src/dhcp-manager/nm-dhcp-dhcpcd.h
@@ -41,7 +41,7 @@ typedef struct {
 
 GType nm_dhcp_dhcpcd_get_type (void);
 
-const char *nm_dhcp_dhcpcd_get_path (const char *try_first);
+const char *nm_dhcp_dhcpcd_get_path (void);
 
 #endif /* __NETWORKMANAGER_DHCP_DHCPCD_H__ */
 
diff --git a/src/dhcp-manager/nm-dhcp-manager.c b/src/dhcp-manager/nm-dhcp-manager.c
index a1bbbef50f..f24aad8dcc 100644
--- a/src/dhcp-manager/nm-dhcp-manager.c
+++ b/src/dhcp-manager/nm-dhcp-manager.c
@@ -285,23 +285,16 @@ dis_connection_cb (NMDBusManager *mgr,
 static GType
 get_client_type (const char *client, GError **error)
 {
-	const char *dhclient_path = NULL;
-	const char *dhcpcd_path = NULL;
+	gboolean use_dhclient, use_dhcpcd;
 
-	/* If a client was disabled at build-time, its *_PATH define will be
-	 * an empty string.
-	 */
-	/* coverity[array_null] */
-	if (DHCLIENT_PATH && strlen (DHCLIENT_PATH))
-		dhclient_path = nm_dhcp_dhclient_get_path (DHCLIENT_PATH);
-	/* coverity[array_null] */
-	if (DHCPCD_PATH && strlen (DHCPCD_PATH))
-		dhcpcd_path = nm_dhcp_dhcpcd_get_path (DHCPCD_PATH);
+	/* If a client was disabled at build-time, these will return FALSE */
+	use_dhclient = !!nm_dhcp_dhclient_get_path ();
+	use_dhcpcd = !!nm_dhcp_dhcpcd_get_path ();
 
 	if (!client) {
-		if (dhclient_path)
+		if (use_dhclient)
 			return NM_TYPE_DHCP_DHCLIENT;
-		else if (dhcpcd_path)
+		else if (use_dhcpcd)
 			return NM_TYPE_DHCP_DHCPCD;
 		else {
 			g_set_error_literal (error,
@@ -312,20 +305,20 @@ get_client_type (const char *client, GError **error)
 	}
 
 	if (!strcmp (client, "dhclient")) {
-		if (!dhclient_path) {
+		if (!use_dhclient) {
 			g_set_error_literal (error,
 			                     NM_DHCP_MANAGER_ERROR, NM_DHCP_MANAGER_ERROR_BAD_CLIENT,
-			                     _("'dhclient' could be found."));
+			                     _("'dhclient' could not be found or was disabled."));
 			return G_TYPE_INVALID;
 		}
 		return NM_TYPE_DHCP_DHCLIENT;
 	}
 
 	if (!strcmp (client, "dhcpcd")) {
-		if (!dhcpcd_path) {
+		if (!use_dhcpcd) {
 			g_set_error_literal (error,
 			                     NM_DHCP_MANAGER_ERROR, NM_DHCP_MANAGER_ERROR_BAD_CLIENT,
-			                     _("'dhcpcd' could be found."));
+			                     _("'dhcpcd' could not be found or was disabled."));
 			return G_TYPE_INVALID;
 		}
 		return NM_TYPE_DHCP_DHCPCD;
diff --git a/src/dns-manager/nm-dns-dnsmasq.c b/src/dns-manager/nm-dns-dnsmasq.c
index 8367693da7..416cfe3b01 100644
--- a/src/dns-manager/nm-dns-dnsmasq.c
+++ b/src/dns-manager/nm-dns-dnsmasq.c
@@ -35,6 +35,7 @@
 #include "nm-ip4-config.h"
 #include "nm-ip6-config.h"
 #include "nm-dns-utils.h"
+#include "NetworkManagerUtils.h"
 
 G_DEFINE_TYPE (NMDnsDnsmasq, nm_dns_dnsmasq, NM_TYPE_DNS_PLUGIN)
 
@@ -50,26 +51,6 @@ typedef struct {
 
 /*******************************************/
 
-static inline const char *
-find_dnsmasq (void)
-{
-	static const char *paths[] = {
-		DNSMASQ_PATH,
-		"/usr/local/sbin/dnsmasq",
-		"/usr/sbin/dnsmasq",
-		"/sbin/dnsmasq",
-		NULL
-	};
-	const char **binary = paths;
-
-	while (*binary != NULL) {
-		if (**binary && g_file_test (*binary, G_FILE_TEST_EXISTS))
-			return *binary;
-		binary++;
-	}
-	return NULL;
-}
-
 static gboolean
 add_ip4_config (GString *str, NMIP4Config *ip4, gboolean split)
 {
@@ -225,6 +206,7 @@ update (NMDnsPlugin *plugin,
         const char *hostname)
 {
 	NMDnsDnsmasq *self = NM_DNS_DNSMASQ (plugin);
+	const char *dm_binary;
 	GString *conf;
 	GSList *iter;
 	const char *argv[15];
@@ -240,6 +222,12 @@ update (NMDnsPlugin *plugin,
 	 */
 	nm_dns_plugin_child_kill (plugin);
 
+	dm_binary = nm_utils_find_helper ("dnsmasq", DNSMASQ_PATH, NULL);
+	if (!dm_binary) {
+		nm_log_warn (LOGD_DNS, "Could not find dnsmasq binary");
+		return FALSE;
+	}
+
 	/* Build up the new dnsmasq config file */
 	conf = g_string_sized_new (150);
 
@@ -281,7 +269,7 @@ update (NMDnsPlugin *plugin,
 	nm_log_dbg (LOGD_DNS, "dnsmasq local caching DNS configuration:");
 	nm_log_dbg (LOGD_DNS, "%s", conf->str);
 
-	argv[idx++] = find_dnsmasq ();
+	argv[idx++] = dm_binary;
 	argv[idx++] = "--no-resolv";  /* Use only commandline */
 	argv[idx++] = "--keep-in-foreground";
 	argv[idx++] = "--no-hosts"; /* don't use /etc/hosts to resolve */
diff --git a/src/dnsmasq-manager/nm-dnsmasq-manager.c b/src/dnsmasq-manager/nm-dnsmasq-manager.c
index c76b5fe5c5..7d6337e914 100644
--- a/src/dnsmasq-manager/nm-dnsmasq-manager.c
+++ b/src/dnsmasq-manager/nm-dnsmasq-manager.c
@@ -169,27 +169,6 @@ nm_cmd_line_add_string (NMCmdLine *cmd, const char *str)
 
 /*******************************************/
 
-static inline const char *
-nm_find_dnsmasq (void)
-{
-	static const char *dnsmasq_binary_paths[] = {
-		DNSMASQ_PATH,
-		"/usr/local/sbin/dnsmasq",
-		"/usr/sbin/dnsmasq",
-		"/sbin/dnsmasq",
-		NULL
-	};
-	const char **dnsmasq_binary = dnsmasq_binary_paths;
-
-	while (*dnsmasq_binary != NULL) {
-		if (**dnsmasq_binary && g_file_test (*dnsmasq_binary, G_FILE_TEST_EXISTS))
-			break;
-		dnsmasq_binary++;
-	}
-
-	return *dnsmasq_binary;
-}
-
 static void
 dm_exit_code (guint dm_exit_status)
 {
@@ -250,7 +229,6 @@ create_dm_cmd_line (const char *iface,
                     const char *pidfile,
                     GError **error)
 {
-	const char *dm_binary;
 	NMCmdLine *cmd;
 	GString *s;
 	const NMPlatformIP4Address *tmp;
@@ -258,16 +236,11 @@ create_dm_cmd_line (const char *iface,
 	char last[INET_ADDRSTRLEN];
 	char localaddr[INET_ADDRSTRLEN];
 	char *error_desc = NULL;
+	const char *dm_binary;
 
-	dm_binary = nm_find_dnsmasq ();
-	if (!dm_binary) {
-		g_set_error_literal (error, NM_DNSMASQ_MANAGER_ERROR, NM_DNSMASQ_MANAGER_ERROR_NOT_FOUND,
-		                     "Could not find dnsmasq binary.");
+	dm_binary = nm_utils_find_helper ("dnsmasq", DNSMASQ_PATH, error);
+	if (!dm_binary)
 		return NULL;
-	}
-
-	/* Find the IP4 address to use */
-	tmp = nm_ip4_config_get_address (ip4_config, 0);
 
 	/* Create dnsmasq command line */
 	cmd = nm_cmd_line_new ();
@@ -298,6 +271,9 @@ create_dm_cmd_line (const char *iface,
 	 */
 	nm_cmd_line_add_string (cmd, "--strict-order");
 
+	/* Find the IP4 address to use */
+	tmp = nm_ip4_config_get_address (ip4_config, 0);
+
 	s = g_string_new ("--listen-address=");
 	nm_utils_inet4_ntop (tmp->address, localaddr);
 	g_string_append (s, localaddr);
@@ -311,7 +287,8 @@ create_dm_cmd_line (const char *iface,
 		                     error_desc);
 		nm_log_warn (LOGD_SHARING, "Failed to find DHCP address ranges: %s", error_desc);
 		g_free (error_desc);
-		goto error;
+		nm_cmd_line_destroy (cmd);
+		return NULL;
 	}
 
 	s = g_string_new ("--dhcp-range=");
@@ -332,10 +309,6 @@ create_dm_cmd_line (const char *iface,
 	g_string_free (s, TRUE);
 
 	return cmd;
-
-error:
-	nm_cmd_line_destroy (cmd);
-	return NULL;
 }
 
 static void
diff --git a/src/nm-dcb.c b/src/nm-dcb.c
index 3bdbf7d5ed..3829e1a2e9 100644
--- a/src/nm-dcb.c
+++ b/src/nm-dcb.c
@@ -296,47 +296,20 @@ _fcoe_cleanup (const char *iface,
 	return do_helper (NULL, FCOEADM, run_func, user_data, error, "-d %s", iface);
 }
 
-
-static const char *dcbpaths[] = {
-	"/sbin/dcbtool",
-	"/usr/sbin/dcbtool",
-	"/usr/local/sbin/dcbtool",
-	NULL
-};
-static const char *fcoepaths[] = {
-	"/sbin/fcoeadm",
-	"/usr/sbin/fcoeadm",
-	"/usr/local/sbin/fcoeadm",
-	NULL
-};
-
-
 static gboolean
 run_helper (char **argv, guint which, gpointer user_data, GError **error)
 {
-	static const char *helper_path[2] = { NULL, NULL };
+	const char *helper_path;
 	int exit_status = 0;
 	gboolean success;
 	char *errmsg = NULL, *outmsg = NULL;
-	const char **iter;
 	char *cmdline;
 
-	if (G_UNLIKELY (helper_path[which] == NULL)) {
-		iter = (which == DCBTOOL) ? dcbpaths : fcoepaths;
-		while (*iter) {
-			if (g_file_test (*iter, G_FILE_TEST_EXISTS))
-				helper_path[which] = *iter;
-			iter++;
-		}
-		if (!helper_path[which]) {
-			g_set_error (error, NM_DCB_ERROR, NM_DCB_ERROR_HELPER_NOT_FOUND,
-			             "%s not found",
-			             which == DCBTOOL ? "dcbtool" : "fcoadm");
-			return FALSE;
-		}
-	}
+	helper_path = nm_utils_find_helper ((which == DCBTOOL) ? "dcbtool" : "fcoeadm", NULL, error);
+	if (!helper_path)
+		return FALSE;
 
-	argv[0] = (char *) helper_path[which];
+	argv[0] = (char *) helper_path;
 	cmdline = g_strjoinv (" ", argv);
 	nm_log_dbg (LOGD_DCB, "%s", cmdline);
 
@@ -359,9 +332,9 @@ run_helper (char **argv, guint which, gpointer user_data, GError **error)
 			success = FALSE;
 		}
 	}
+
 	g_free (outmsg);
 	g_free (errmsg);
-
 	g_free (cmdline);
 	return success;
 }
diff --git a/src/ppp-manager/nm-ppp-manager.c b/src/ppp-manager/nm-ppp-manager.c
index 2c9d1c3d04..0b8481d419 100644
--- a/src/ppp-manager/nm-ppp-manager.c
+++ b/src/ppp-manager/nm-ppp-manager.c
@@ -751,36 +751,6 @@ nm_cmd_line_add_int (NMCmdLine *cmd, int i)
 
 /*******************************************/
 
-static const char *pppd_binary_paths[] = {
-	PPPD_PATH,
-	"/usr/local/sbin/pppd",
-	"/usr/sbin/pppd",
-	"/sbin/pppd",
-	NULL
-};
-
-static const char *pppoe_binary_paths[] = {
-	PPPOE_PATH,
-	"/usr/local/sbin/pppoe",
-	"/usr/sbin/pppoe",
-	"/sbin/pppoe",
-	NULL
-};
-
-static inline const char *
-nm_find_binary (const char *paths[])
-{
-	const char **binary = paths;
-
-	while (*binary != NULL) {
-		if (**binary && g_file_test (*binary, G_FILE_TEST_EXISTS))
-			break;
-		binary++;
-	}
-
-	return *binary;
-}
-
 static void
 ppp_exit_code (guint pppd_exit_status, GPid pid)
 {
@@ -900,27 +870,21 @@ create_pppd_cmd_line (NMPPPManager *self,
                       GError **err)
 {
 	NMPPPManagerPrivate *priv = NM_PPP_MANAGER_GET_PRIVATE (self);
-	const char *pppd_binary, *pppoe_binary = NULL;
+	const char *pppd_binary = NULL, *pppoe_binary = NULL;
 	NMCmdLine *cmd;
 	gboolean ppp_debug;
 
 	g_return_val_if_fail (setting != NULL, NULL);
 
-	pppd_binary = nm_find_binary (pppd_binary_paths);
-	if (!pppd_binary) {
-		g_set_error (err, NM_PPP_MANAGER_ERROR, NM_PPP_MANAGER_ERROR,
-		             "Could not find pppd binary.");
+	pppd_binary = nm_utils_find_helper ("pppd", NULL, err);
+	if (!pppd_binary)
 		return NULL;
-	}
 
 	if (   pppoe
 	    || (adsl && strcmp (nm_setting_adsl_get_protocol (adsl), NM_SETTING_ADSL_PROTOCOL_PPPOE))) {
-		pppoe_binary = nm_find_binary (pppoe_binary_paths);
-		if (!pppoe_binary) {
-			g_set_error (err, NM_PPP_MANAGER_ERROR, NM_PPP_MANAGER_ERROR,
-			             "Could not find pppoe binary.");
+		pppoe_binary = nm_utils_find_helper ("pppoe", NULL, err);
+		if (!pppoe_binary)
 			return NULL;
-		}
 	}
 
 	/* Create pppd command line */