config: add support for per-device configuration to NetworkManager.conf

Add a new [device*] section to NetworkManager.conf. This works similar
like the default connection settings in [connection*].

This will allow us to express per-device configuration in NetworkManager.conf
in our familar style.

Later, via NMConfig's write API it will be possible to make settings
accessible via D-Bus and persist them in NetworkManager-intern.conf.
This way, the user can both edit configuration snippets and modify
them via D-Bus, and also support installing default configuration
from the package.

In a way, a [device*] setting is similar to networkd's link files.
The match options is all encoded in the match-device specs.
One difference is, that the resulting setting can be merged together
by multiple section by partially overwriting them. This makes it
more flexible and allows for example to drop a configuration snippet
that only sets one property, while the rest can be merged from different
snippets.

1 files changed, 147 insertions, 47 deletions

diff --git a/src/nm-config-data.c b/src/nm-config-data.c
index 28057b47a6..37686479c5 100644
--- a/src/nm-config-data.c
+++ b/src/nm-config-data.c
@@ -40,7 +40,7 @@ typedef struct {
 		gboolean has;
 		GSList *spec;
 	} match_device;
-} ConnectionInfo;
+} MatchSectionInfo;
 
 typedef struct {
 	char *config_main_file;
@@ -52,7 +52,11 @@ typedef struct {
 
 	/* A zero-terminated list of pre-processed information from the
 	 * [connection] sections. This is to speed up lookup. */
-	ConnectionInfo *connection_infos;
+	MatchSectionInfo *connection_infos;
+
+	/* A zero-terminated list of pre-processed information from the
+	 * [device] sections. This is to speed up lookup. */
+	MatchSectionInfo *device_infos;
 
 	struct {
 		char *uri;
@@ -451,6 +455,7 @@ static int
 _nm_config_data_log_sort (const char **pa, const char **pb, gpointer dummy)
 {
 	gboolean a_is_connection, b_is_connection;
+	gboolean a_is_device, b_is_device;
 	gboolean a_is_intern, b_is_intern;
 	const char *a = *pa;
 	const char *b = *pb;
@@ -488,6 +493,28 @@ _nm_config_data_log_sort (const char **pa, const char **pb, gpointer dummy)
 	if (b_is_connection && !a_is_connection)
 		return -1;
 
+	/* we sort device groups before connection groups (to the end). */
+	a_is_device = a && g_str_has_prefix (a, NM_CONFIG_KEYFILE_GROUPPREFIX_DEVICE);
+	b_is_device = b && g_str_has_prefix (b, NM_CONFIG_KEYFILE_GROUPPREFIX_DEVICE);
+
+	if (a_is_device && b_is_device) {
+		/* if both are device groups, we want the explicit [device] group first. */
+		a_is_device = a[NM_STRLEN (NM_CONFIG_KEYFILE_GROUPPREFIX_DEVICE)] == '\0';
+		b_is_device = b[NM_STRLEN (NM_CONFIG_KEYFILE_GROUPPREFIX_DEVICE)] == '\0';
+
+		if (a_is_device != b_is_device) {
+			if (a_is_device)
+				return -1;
+			return 1;
+		}
+		/* the sections are ordered lowest-priority first. Reverse their order. */
+		return pa < pb ? 1 : -1;
+	}
+	if (a_is_device && !b_is_device)
+		return 1;
+	if (b_is_device && !a_is_device)
+		return -1;
+
 	/* no reordering. */
 	return 0;
 }
@@ -1049,25 +1076,18 @@ global_dns_equal (NMGlobalDnsConfig *old, NMGlobalDnsConfig *new)
 
 /************************************************************************/
 
-char *
-nm_config_data_get_connection_default (const NMConfigData *self,
-                                       const char *property,
-                                       NMDevice *device)
+static const MatchSectionInfo *
+_match_section_infos_lookup (const MatchSectionInfo *match_section_infos,
+                             GKeyFile *keyfile,
+                             const char *property,
+                             NMDevice *device,
+                             char **out_value)
 {
-	NMConfigDataPrivate *priv;
-	const ConnectionInfo *connection_info;
-
-	g_return_val_if_fail (self, NULL);
-	g_return_val_if_fail (property && *property, NULL);
-	g_return_val_if_fail (strchr (property, '.'), NULL);
-
-	priv = NM_CONFIG_DATA_GET_PRIVATE (self);
-
-	if (!priv->connection_infos)
+	if (!match_section_infos)
 		return NULL;
 
-	for (connection_info = &priv->connection_infos[0]; connection_info->group_name; connection_info++) {
-		char *value;
+	for (; match_section_infos->group_name; match_section_infos++) {
+		char *value = NULL;
 		gboolean match;
 
 		/* FIXME: Here we use g_key_file_get_string(). This should be in sync with what keyfile-reader
@@ -1077,23 +1097,87 @@ nm_config_data_get_connection_default (const NMConfigData *self,
 		 * string_to_value(keyfile_to_string(keyfile)) in one. Optimally, keyfile library would
 		 * expose both functions, and we would return here keyfile_to_string(keyfile).
 		 * The caller then could convert the string to the proper value via string_to_value(value). */
-		value = g_key_file_get_string (priv->keyfile, connection_info->group_name, property, NULL);
-		if (!value && !connection_info->stop_match)
+		value = g_key_file_get_string (keyfile, match_section_infos->group_name, property, NULL);
+		if (!value && !match_section_infos->stop_match)
 			continue;
 
 		match = TRUE;
-		if (connection_info->match_device.has)
-			match = device && nm_device_spec_match_list (device, connection_info->match_device.spec);
+		if (match_section_infos->match_device.has)
+			match = device && nm_device_spec_match_list (device, match_section_infos->match_device.spec);
 
-		if (match)
-			return value;
+		if (match) {
+			*out_value = value;
+			return match_section_infos;
+		}
 		g_free (value);
 	}
 	return NULL;
 }
 
+char *
+nm_config_data_get_device_config (const NMConfigData *self,
+                                  const char *property,
+                                  NMDevice *device,
+                                  gboolean *has_match)
+{
+	NMConfigDataPrivate *priv;
+	const MatchSectionInfo *connection_info;
+	char *value = NULL;
+
+	g_return_val_if_fail (self, NULL);
+	g_return_val_if_fail (property && *property, NULL);
+
+	priv = NM_CONFIG_DATA_GET_PRIVATE (self);
+
+	connection_info = _match_section_infos_lookup (&priv->device_infos[0],
+	                                               priv->keyfile,
+	                                               property,
+	                                               device,
+	                                               &value);
+	NM_SET_OUT (has_match, !!connection_info);
+	return value;
+}
+
+gboolean
+nm_config_data_get_device_config_boolean (const NMConfigData *self,
+                                          const char *property,
+                                          NMDevice *device,
+                                          gint val_no_match,
+                                          gint val_invalid)
+{
+	gs_free char *value = NULL;
+	gboolean has_match;
+
+	value = nm_config_data_get_device_config (self, property, device, &has_match);
+	if (!has_match)
+		return val_no_match;
+	return nm_config_parse_boolean (value, val_invalid);
+}
+
+char *
+nm_config_data_get_connection_default (const NMConfigData *self,
+                                       const char *property,
+                                       NMDevice *device)
+{
+	NMConfigDataPrivate *priv;
+	char *value = NULL;
+
+	g_return_val_if_fail (self, NULL);
+	g_return_val_if_fail (property && *property, NULL);
+	g_return_val_if_fail (strchr (property, '.'), NULL);
+
+	priv = NM_CONFIG_DATA_GET_PRIVATE (self);
+
+	_match_section_infos_lookup (&priv->connection_infos[0],
+	                             priv->keyfile,
+	                             property,
+	                             device,
+	                             &value);
+	return value;
+}
+
 static void
-_get_connection_info_init (ConnectionInfo *connection_info, GKeyFile *keyfile, char *group)
+_get_connection_info_init (MatchSectionInfo *connection_info, GKeyFile *keyfile, char *group)
 {
 	/* pass ownership of @group on... */
 	connection_info->group_name = group;
@@ -1105,27 +1189,43 @@ _get_connection_info_init (ConnectionInfo *connection_info, GKeyFile *keyfile, c
 	connection_info->stop_match = nm_config_keyfile_get_boolean (keyfile, group, "stop-match", FALSE);
 }
 
-static ConnectionInfo *
-_get_connection_infos (GKeyFile *keyfile)
+static void
+_match_section_infos_free (MatchSectionInfo *match_section_infos)
+{
+	guint i;
+
+	if (!match_section_infos)
+		return;
+	for (i = 0; match_section_infos[i].group_name; i++) {
+		g_free (match_section_infos[i].group_name);
+		g_slist_free_full (match_section_infos[i].match_device.spec, g_free);
+	}
+	g_free (match_section_infos);
+}
+
+static MatchSectionInfo *
+_match_section_infos_construct (GKeyFile *keyfile, const char *prefix)
 {
 	char **groups;
 	gsize i, j, ngroups;
 	char *connection_tag = NULL;
-	ConnectionInfo *connection_infos = NULL;
+	MatchSectionInfo *match_section_infos = NULL;
 
-	/* get the list of existing [connection.\+] sections that we consider
-	 * for nm_config_data_get_connection_default().
+	/* get the list of existing [connection.\+]/[device.\+] sections.
 	 *
 	 * We expect the sections in their right order, with lowest priority
 	 * first. Only exception is the (literal) [connection] section, which
 	 * we will always reorder to the end. */
 	groups = g_key_file_get_groups (keyfile, &ngroups);
 	if (!groups)
-		ngroups = 0;
-	else if (ngroups > 0) {
+		return NULL;
+
+	if (ngroups > 0) {
+		gsize l = strlen (prefix);
+
 		for (i = 0, j = 0; i < ngroups; i++) {
-			if (g_str_has_prefix (groups[i], NM_CONFIG_KEYFILE_GROUPPREFIX_CONNECTION)) {
-				if (groups[i][NM_STRLEN (NM_CONFIG_KEYFILE_GROUPPREFIX_CONNECTION)] == '\0')
+			if (g_str_has_prefix (groups[i], prefix)) {
+				if (groups[i][l] == '\0')
 					connection_tag = groups[i];
 				else
 					groups[j++] = groups[i];
@@ -1135,18 +1235,23 @@ _get_connection_infos (GKeyFile *keyfile)
 		ngroups = j;
 	}
 
-	connection_infos = g_new0 (ConnectionInfo, ngroups + 1 + (connection_tag ? 1 : 0));
+	if (ngroups == 0 && !connection_tag) {
+		g_free (groups);
+		return NULL;
+	}
+
+	match_section_infos = g_new0 (MatchSectionInfo, ngroups + 1 + (connection_tag ? 1 : 0));
 	for (i = 0; i < ngroups; i++) {
 		/* pass ownership of @group on... */
-		_get_connection_info_init (&connection_infos[i], keyfile, groups[ngroups - i - 1]);
+		_get_connection_info_init (&match_section_infos[i], keyfile, groups[ngroups - i - 1]);
 	}
 	if (connection_tag) {
 		/* pass ownership of @connection_tag on... */
-		_get_connection_info_init (&connection_infos[i], keyfile, connection_tag);
+		_get_connection_info_init (&match_section_infos[i], keyfile, connection_tag);
 	}
 	g_free (groups);
 
-	return connection_infos;
+	return match_section_infos;
 }
 
 /************************************************************************/
@@ -1306,7 +1411,6 @@ static void
 finalize (GObject *gobject)
 {
 	NMConfigDataPrivate *priv = NM_CONFIG_DATA_GET_PRIVATE (gobject);
-	guint i;
 
 	g_free (priv->config_main_file);
 	g_free (priv->config_description);
@@ -1326,13 +1430,8 @@ finalize (GObject *gobject)
 
 	nm_global_dns_config_free (priv->global_dns);
 
-	if (priv->connection_infos) {
-		for (i = 0; priv->connection_infos[i].group_name; i++) {
-			g_free (priv->connection_infos[i].group_name);
-			g_slist_free_full (priv->connection_infos[i].match_device.spec, g_free);
-		}
-		g_free (priv->connection_infos);
-	}
+	_match_section_infos_free (priv->connection_infos);
+	_match_section_infos_free (priv->device_infos);
 
 	g_key_file_unref (priv->keyfile);
 	if (priv->keyfile_user)
@@ -1359,7 +1458,8 @@ constructed (GObject *object)
 
 	priv->keyfile = _merge_keyfiles (priv->keyfile_user, priv->keyfile_intern);
 
-	priv->connection_infos = _get_connection_infos (priv->keyfile);
+	priv->connection_infos = _match_section_infos_construct (priv->keyfile, NM_CONFIG_KEYFILE_GROUPPREFIX_CONNECTION);
+	priv->device_infos = _match_section_infos_construct (priv->keyfile, NM_CONFIG_KEYFILE_GROUPPREFIX_DEVICE);
 
 	priv->connectivity.uri = nm_strstrip (g_key_file_get_string (priv->keyfile, NM_CONFIG_KEYFILE_GROUP_CONNECTIVITY, "uri", NULL));
 	priv->connectivity.response = g_key_file_get_string (priv->keyfile, NM_CONFIG_KEYFILE_GROUP_CONNECTIVITY, "response", NULL);