diff --git a/a.out b/a.out
deleted file mode 100644
index f6d4755..0000000
Binary files a/a.out and /dev/null differ
diff --git a/cache.c b/cache.c
index 77ea9dd..06263b9 100644
--- a/cache.c
+++ b/cache.c
@@ -48,6 +48,8 @@ int is_ip_in_cache(const char *ip)
     struct ip_cache_node *current = ip_cache_head;
     struct ip_cache_node *prev = NULL;
 
+    if (ip_cache_head == NULL) return 0;    // 如果 ip_cache_head == NULL，current->next 可能导致段错误 (Segmentation Fault)。
+
     while (current != NULL) {
         // 如果 IP 匹配并且未过期
         if (strcmp(current->ip, ip) == 0) {
diff --git a/cap.c b/cap.c
index 35c5988..638421e 100644
--- a/cap.c
+++ b/cap.c
@@ -23,6 +23,7 @@ char    *command_result = NULL; // 执行命令的结果
 
 void Processing_IP_addresses(char *src_ip)
 {
+
     // 地域白名单
     char _region_list[WHITELIST_IP_NUM][WHITELIST_IP_NUM] = { { 0 }, { 0 } };
     char _REGION_LIST[BUFFER] = { 0 };
@@ -108,11 +109,11 @@ void Processing_IP_addresses(char *src_ip)
             fprintf(stderr, "Failed to parse JSON.\n");
         }
 
-        if (p != NULL)
+        if (p != NULL) {
             free(p);
+        }
     }
 
-       
     if (ip2region_area != NULL) {
         free(ip2region_area);
         ip2region_area = NULL;
@@ -125,9 +126,14 @@ void Processing_IP_addresses(char *src_ip)
 void packet_handler(u_char *args, const struct pcap_pkthdr *header, const u_char *packet)
 {
     int ethernet_header_len = 14;
+    //struct ip *ip_header = (struct ip *)(packet + ethernet_header_len);
     struct ip *ip_header = (struct ip *)(packet + ethernet_header_len);
+    if (ip_header->ip_v != 4) return;  // 只处理 IPv4
+
     char src_ip[INET_ADDRSTRLEN] = { 0 };
 
+
+
     inet_ntop(AF_INET, &(ip_header->ip_src), src_ip, INET_ADDRSTRLEN);
     Processing_IP_addresses(src_ip);