use local private ip first as machine id

src/id_generator.c

@@ -49,15 +49,30 @@ int id_generator_init_ex(struct idg_context *context, const char *filename,
 	else
 	{
 		const char *local_ip;
+		const char *private_ip;
 		struct in_addr ip_addr;
 
-		local_ip = get_first_local_ip();
-		if (local_ip == NULL)
+		private_ip = get_first_local_private_ip();
+		if (private_ip != NULL)
 		{
-			logError("file: "__FILE__", line: %d, "
-				"can't get local ip address", __LINE__);
-			context->fd = -1;
-			return ENOENT;
+			local_ip = private_ip;
+		}
+		else
+		{
+			local_ip = get_first_local_ip();
+			if (local_ip == NULL)
+			{
+				logError("file: "__FILE__", line: %d, "
+					"can't get local ip address", __LINE__);
+				context->fd = -1;
+				return ENOENT;
+			}
+			else if (strcmp(local_ip, LOCAL_LOOPBACK_IP) == 0)
+			{
+				logWarning("file: "__FILE__", line: %d, "
+					"can't get local ip address, set to %s",
+					__LINE__, LOCAL_LOOPBACK_IP);
+			}
 		}
 
 		if (inet_pton(AF_INET, local_ip, &ip_addr) != 1)

src/local_ip_func.c

@@ -14,8 +14,6 @@
 #include "shared_func.h"
 #include "local_ip_func.h"
 
-#define LOCAL_LOOPBACK_IP  "127.0.0.1"
-
 int g_local_host_ip_count = 0;
 char g_local_host_ip_addrs[FAST_MAX_LOCAL_IP_ADDRS * \
 				IP_ADDRESS_SIZE];
@@ -180,3 +178,24 @@ const char *get_first_local_ip()
     }
 }
 
+const char *get_first_local_private_ip()
+{
+    const char *ip;
+
+    ip = NULL;
+    do
+    {
+        ip = get_next_local_ip(ip);
+        if (ip == NULL)
+        {
+            return NULL;
+        }
+        if (is_private_ip(ip))
+        {
+            return ip;
+        }
+    } while (1);
+
+    return NULL;
+}
+

src/local_ip_func.h

@@ -20,6 +20,8 @@
 #define FAST_IF_ALIAS_PREFIX_MAX_SIZE 32
 #define FAST_MAX_LOCAL_IP_ADDRS	  16
 
+#define LOCAL_LOOPBACK_IP  "127.0.0.1"
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -35,6 +37,8 @@ bool is_local_host_ip(const char *client_ip);
 const char *get_first_local_ip();
 const char *get_next_local_ip(const char *previous_ip);
 
+const char *get_first_local_private_ip();
+
 int insert_into_local_host_ip(const char *client_ip);
 void log_local_host_ip_addrs();
 void print_local_host_ip_addrs();

src/tests/test_id_generator.c

@@ -20,7 +20,7 @@ int main(int argc, char *argv[])
 	int result;
 	int i;
 	int64_t id;
-	const int machine_id = 192;
+	const int machine_id = 0;
 	const int mid_bits = 8;
 	
 	log_init();
@@ -36,7 +36,7 @@ int main(int argc, char *argv[])
 
 	//id_generator_next(&context, &id);
 	//printf("id: %"PRId64", %016llX\n", id, id);
-	for (i=0; i<100000; i++)
+	for (i=0; i<10000; i++)
 	{
 		result = id_generator_next(&context, &id);
 		if (result != 0)