dhcpv6: Do not fail when no keyfile saved

During a DHCPv6 transaction, a DUID field was requested from storage by
calling connman_service_load_service, which tried to open the keyfile on
drive. If the service was not a newly created one, its data would get
written to the keyfile and DHCPv6 solicitation would proceed, even if
the keyfile would not contain the DUID value - a new one would be
generated with the set_duid function.

However, since the function connman_service_load_service fails when the
file is not present, and does not create a new one, the rest of the
set_duid function was not executed, and the DHCPv6 solicitation packet
failed to be sent, rendering IPv6 on the interface as non-working.

Also, the previous behaviour interferes badly with keyfile storage.
A potential service save operation may overwrite the previously written
duid value.

This change adds a struct connman_ipconfig member, dhcpv6_duid, provides
a getter and setter functions for it, and modifies
__connman_ipconfig_load and __connman_ipconfig_save functions to load
and store the value along with the connman_ipconfig structure.
Initialization did not need to be modified, since the structure is
allocated with g_try_new0, which zeros the dhcpv6_duid pointer. The
memory is freed in __connman_ipconfig_unref_debug.

connman/src/connman.h

@@ -520,6 +520,9 @@ char *__connman_ipconfig_get_dhcp_address(struct connman_ipconfig *ipconfig);
 void __connman_ipconfig_set_dhcpv6_prefixes(struct connman_ipconfig *ipconfig,
 					char **prefixes);
 char **__connman_ipconfig_get_dhcpv6_prefixes(struct connman_ipconfig *ipconfig);
+void __connman_ipconfig_set_dhcpv6_duid(struct connman_ipconfig *ipconfig,
+					const char *dhcpv6_duid);
+char *__connman_ipconfig_get_dhcpv6_duid(struct connman_ipconfig *ipconfig);
 
 void __connman_ipconfig_load(struct connman_ipconfig *ipconfig,
 		GKeyFile *keyfile, const char *identifier, const char *prefix);

connman/src/dhcpv6.c

@@ -191,30 +191,23 @@ static int set_duid(struct connman_service *service,
 			struct connman_network *network,
 			GDHCPClient *dhcp_client, int index)
 {
-	GKeyFile *keyfile;
-	const char *ident;
 	char *hex_duid;
 	unsigned char *duid;
 	int duid_len;
+	struct connman_ipconfig *ip6config;
 
-	ident = connman_service_get_identifier(service);
-
-	keyfile = connman_storage_load_service(ident);
-	if (!keyfile)
+	ip6config = __connman_service_get_ip6config(service);
+	if (!ip6config)
 		return -EINVAL;
 
-	hex_duid = g_key_file_get_string(keyfile, ident, "IPv6.DHCP.DUID",
-					NULL);
+	hex_duid = __connman_ipconfig_get_dhcpv6_duid(ip6config);
 	if (hex_duid) {
 		unsigned int i, j = 0, hex;
 		size_t hex_duid_len = strlen(hex_duid);
 
 		duid = g_try_malloc0(hex_duid_len / 2);
-		if (!duid) {
-			g_key_file_unref(keyfile);
-			g_free(hex_duid);
+		if (!duid)
 			return -ENOMEM;
-		}
 
 		for (i = 0; i < hex_duid_len; i += 2) {
 			sscanf(hex_duid + i, "%02x", &hex);
@@ -228,26 +221,18 @@ static int set_duid(struct connman_service *service,
 
 		ret = g_dhcpv6_create_duid(G_DHCPV6_DUID_LLT, index, type,
 					&duid, &duid_len);
-		if (ret < 0) {
-			g_key_file_unref(keyfile);
+		if (ret < 0)
 			return ret;
-		}
 
 		hex_duid = convert_to_hex(duid, duid_len);
 		if (!hex_duid) {
 			g_free(duid);
-			g_key_file_unref(keyfile);
 			return -ENOMEM;
 		}
 
-		g_key_file_set_string(keyfile, ident, "IPv6.DHCP.DUID",
-				hex_duid);
-
-		__connman_storage_save_service(keyfile, ident);
+		__connman_ipconfig_set_dhcpv6_duid(ip6config, hex_duid);
+		g_free(hex_duid);
 	}
-	g_free(hex_duid);
-
-	g_key_file_unref(keyfile);
 
 	g_dhcpv6_client_set_duid(dhcp_client, duid, duid_len);
 
@@ -405,6 +390,8 @@ static int dhcpv6_info_request(struct connman_dhcpv6 *dhcp)
 
 	ret = set_duid(service, dhcp->network, dhcp_client, index);
 	if (ret < 0) {
+		DBG("dhcp %p failed to set dhcpv6 duid for service %p",
+								dhcp, service);
 		clear_timer(dhcp);
 		g_dhcp_client_unref(dhcp_client);
 		return ret;
@@ -1759,6 +1746,8 @@ static int dhcpv6_solicitation(struct connman_dhcpv6 *dhcp)
 
 	ret = set_duid(service, dhcp->network, dhcp_client, index);
 	if (ret < 0) {
+		DBG("dhcp %p failed to set dhcpv6 duid for service %p",
+								dhcp, service);
 		clear_timer(dhcp);
 		g_dhcp_client_unref(dhcp_client);
 		return ret;
@@ -2077,6 +2066,8 @@ static GDHCPClient *create_pd_client(struct connman_dhcpv6 *dhcp, int *err)
 
 	ret = set_duid(service, dhcp->network, dhcp_client, index);
 	if (ret < 0) {
+		DBG("dhcp %p failed to set dhcpv6 duid for service %p",
+								dhcp, service);
 		g_dhcp_client_unref(dhcp_client);
 		*err = ret;
 		return NULL;

connman/src/ipconfig.c

@@ -57,6 +57,7 @@ struct connman_ipconfig {
 	int ipv6_autoconf_config;
 	char *last_dhcp_address;
 	char **last_dhcpv6_prefixes;
+	char *dhcpv6_duid;
 
 	bool ipv6_force_disabled;
 };
@@ -1446,6 +1447,7 @@ void __connman_ipconfig_unref_debug(struct connman_ipconfig *ipconfig,
 	connman_ipaddress_free(ipconfig->address);
 	g_free(ipconfig->last_dhcp_address);
 	g_strfreev(ipconfig->last_dhcpv6_prefixes);
+	g_free(ipconfig->dhcpv6_duid);
 	g_free(ipconfig);
 }
 
@@ -1685,6 +1687,24 @@ char **__connman_ipconfig_get_dhcpv6_prefixes(struct connman_ipconfig *ipconfig)
 	return ipconfig->last_dhcpv6_prefixes;
 }
 
+void __connman_ipconfig_set_dhcpv6_duid(struct connman_ipconfig *ipconfig,
+						const char *dhcpv6_duid)
+{
+	if (!ipconfig)
+		return;
+
+	g_free(ipconfig->dhcpv6_duid);
+	ipconfig->dhcpv6_duid = g_strdup(dhcpv6_duid);
+}
+
+char *__connman_ipconfig_get_dhcpv6_duid(struct connman_ipconfig *ipconfig)
+{
+	if (!ipconfig)
+		return NULL;
+
+	return ipconfig->dhcpv6_duid;
+}
+
 static int disable_ipv6(struct connman_ipconfig *ipconfig, bool forced)
 {
 	struct connman_ipdevice *ipdevice;
@@ -2472,6 +2492,8 @@ void __connman_ipconfig_load(struct connman_ipconfig *ipconfig,
 		g_strfreev(ipconfig->last_dhcpv6_prefixes);
 		ipconfig->last_dhcpv6_prefixes =
 			store_get_strs(&is, "DHCP.LastPrefixes");
+
+		ipconfig->dhcpv6_duid = store_get_str(&is, "DHCP.DUID");
 	}
 
 
@@ -2548,6 +2570,8 @@ void __connman_ipconfig_save(struct connman_ipconfig *ipconfig,
 
 		store_set_strs(&is, "DHCP.LastPrefixes",
 				ipconfig->last_dhcpv6_prefixes);
+
+		store_set_str(&is, "DHCP.DUID", ipconfig->dhcpv6_duid);
 	}
 
 	switch (ipconfig->method) {