[1/2] add option to omit dhcp client identifier

Commit Message

António Oliveira Dec. 20, 2023, 3:42 p.m. UTC

* add "OmitClientIdenfier" option to main.conf, which causes the DHCP
  client to not include the option 61 (Client Identifier) in DHCP
  packets.

Signed-off-by: António Oliveira <[e-mail]>
---
 src/dhcp.c | 18 ++++++++++++++++--
 src/main.c | 17 +++++++++++++++++
 2 files changed, 33 insertions(+), 2 deletions(-)

Patch

diff --git a/src/dhcp.c b/src/dhcp.c
index 18dbab27..d7689ae4 100644
--- a/src/dhcp.c
+++ b/src/dhcp.c
@@ -61,6 +61,7 @@  struct connman_dhcp {
 	char *dhcp_debug_prefix;
 
 	bool ipv4ll_running;
+	bool omit_client_identifier;
 };
 
 static GHashTable *ipconfig_table;
@@ -209,7 +210,9 @@  static int ipv4ll_start_client(struct connman_dhcp *dhcp)
 					dhcp->ipv4ll_debug_prefix);
 	}
 
-	g_dhcp_client_set_id(ipv4ll_client);
+	if ( !dhcp->omit_client_identifier ) {
+		g_dhcp_client_set_id(ipv4ll_client);
+	}
 
 	if (dhcp->network) {
 		hostname = connman_utsname_get_hostname();
@@ -572,6 +575,7 @@  static int dhcp_initialize(struct connman_dhcp *dhcp)
 	GDHCPClientError error;
 	int index;
 	const char *vendor_class_id;
+	const char *omit_client_id;
 
 	DBG("dhcp %p", dhcp);
 
@@ -588,7 +592,17 @@  static int dhcp_initialize(struct connman_dhcp *dhcp)
 					dhcp->dhcp_debug_prefix);
 	}
 
-	g_dhcp_client_set_id(dhcp_client);
+	omit_client_id = connman_setting_get_string("OmitClientIdentifier");
+	if ( omit_client_id && g_str_equal(omit_client_id,"true" ) ) {
+		dhcp->omit_client_identifier = true;
+	}
+	else {
+		dhcp->omit_client_identifier = false;
+	}
+
+	if ( ! dhcp->omit_client_identifier ) {
+		g_dhcp_client_set_id(dhcp_client);
+	}
 
 	if (dhcp->network) {
 		struct connman_service *service;
diff --git a/src/main.c b/src/main.c
index d2ec8296..7b3d8b17 100644
--- a/src/main.c
+++ b/src/main.c
@@ -107,6 +107,7 @@  static struct {
 	bool persistent_tethering_mode;
 	bool enable_6to4;
 	char *vendor_class_id;
+	char *omit_client_id;
 	bool enable_online_check;
 	bool enable_online_to_ready_transition;
 	char *online_check_ipv4_url;
@@ -139,6 +140,7 @@  static struct {
 	.persistent_tethering_mode = false,
 	.enable_6to4 = false,
 	.vendor_class_id = NULL,
+	.omit_client_id = NULL,
 	.enable_online_check = true,
 	.enable_online_to_ready_transition = false,
 	.online_check_ipv4_url = NULL,
@@ -171,6 +173,7 @@  static struct {
 #define CONF_PERSISTENT_TETHERING_MODE  "PersistentTetheringMode"
 #define CONF_ENABLE_6TO4                "Enable6to4"
 #define CONF_VENDOR_CLASS_ID            "VendorClassID"
+#define CONF_OMIT_CLIENT_ID             "OmitClientIdentifier"
 #define CONF_ENABLE_ONLINE_CHECK        "EnableOnlineCheck"
 #define CONF_ENABLE_ONLINE_TO_READY_TRANSITION "EnableOnlineToReadyTransition"
 #define CONF_ONLINE_CHECK_IPV4_URL      "OnlineCheckIPv4URL"
@@ -204,6 +207,7 @@  static const char *supported_options[] = {
 	CONF_PERSISTENT_TETHERING_MODE,
 	CONF_ENABLE_6TO4,
 	CONF_VENDOR_CLASS_ID,
+	CONF_OMIT_CLIENT_ID,
 	CONF_ENABLE_ONLINE_CHECK,
 	CONF_ENABLE_ONLINE_TO_READY_TRANSITION,
 	CONF_ONLINE_CHECK_IPV4_URL,
@@ -518,6 +522,15 @@  static void parse_config(GKeyFile *config)
 
 	g_clear_error(&error);
 
+	string = __connman_config_get_string(config, "General",
+										 CONF_OMIT_CLIENT_ID, &error);
+	if (!error) {
+		connman_settings.omit_client_id = string;
+		connman_info("OMIT_CLIENT_ID: %s\n",string);
+	}
+
+	g_clear_error(&error);
+
 	boolean = __connman_config_get_bool(config, "General",
 					CONF_ENABLE_ONLINE_CHECK, &error);
 	if (!error) {
@@ -843,6 +856,9 @@  char *connman_setting_get_string(const char *key)
 	if (g_str_equal(key, CONF_VENDOR_CLASS_ID))
 		return connman_settings.vendor_class_id;
 
+	if (g_str_equal(key, CONF_OMIT_CLIENT_ID))
+		return connman_settings.omit_client_id;
+
 	if (g_str_equal(key, CONF_ONLINE_CHECK_IPV4_URL))
 		return connman_settings.online_check_ipv4_url;
 
@@ -1146,6 +1162,7 @@  int main(int argc, char *argv[])
 	g_strfreev(connman_settings.blacklisted_interfaces);
 	g_strfreev(connman_settings.tethering_technologies);
 	g_free(connman_settings.vendor_class_id);
+	g_free(connman_settings.omit_client_id);
 	g_free(connman_settings.online_check_ipv4_url);
 	g_free(connman_settings.online_check_ipv6_url);
 	g_free(connman_settings.localtime);