code: fix memory leak

example/osfp_example.c

@@ -25,6 +25,7 @@
 
 #define VLAN_MAX_LAYER  2
 
+struct osfp_db *g_osfp_db;
 
 /* Port is just a uint16_t */
 typedef uint16_t Port;
@@ -496,6 +497,8 @@ void example_detect(struct osfp_db *osfp_db, Packet *p)
         fflush(stdout);
     }
 
+    free(json);
+
 exit:
     if (result) {
         osfp_result_free(result);
@@ -562,6 +565,8 @@ static void signal_handler(int signum)
 
     fflush(stdout);
 
+    osfp_db_free(g_osfp_db);
+
     exit(0);
 }
 
@@ -690,6 +695,8 @@ int main(int argc, char *argv[])
         exit(1);
     }
 
+    g_osfp_db = osfp_db;
+
     // loop
     while (1) {
         int r = pcap_dispatch(pcap_handle, 0, (pcap_handler)process_packet, (void*)osfp_db);    

example/sample.c

@@ -17,6 +17,7 @@ char tcph[] = {
 int main(int argc, char **argv) 
 { 
     const char *json_file_path = "./fp.json";
+    char *detail_json;
  
     struct iphdr *l3_hdr = (struct iphdr *)iph; 
     struct tcphdr *l4_hdr = (struct tcphdr *)tcph; 
@@ -27,7 +28,9 @@ int main(int argc, char **argv)
         struct osfp_result *result = osfp_ipv4_identify(db, l3_hdr, l4_hdr, l4_hdr_len); 
         if (result) { 
             printf("likely os: %s\n", osfp_result_os_name_get(result)); 
-            printf("details: \n%s\n", osfp_result_score_detail_export(result)); 
+            detail_json = osfp_result_score_detail_export(result);
+            printf("details: \n%s\n", detail_json); 
+            free(detail_json);
             osfp_result_free(result);
         } 
         osfp_db_free(db); 

src/osfp.c

@@ -97,11 +97,7 @@ char *osfp_result_score_detail_export(struct osfp_result *result)
     osfp_profile_get_cycle(c1);
 
     if (result == NULL) {
-        return NULL;
-    }
-
-    if (result->json_str != NULL) {
-        return result->json_str;
+        goto exit;
     }
 
     root = cJSON_CreateObject();
@@ -141,7 +137,7 @@ char *osfp_result_score_detail_export(struct osfp_result *result)
         goto exit;
     }
 
-    result->json_str = result_str;
+    cJSON_Delete(root);
 
     osfp_profile_get_cycle(c2);
     osfp_profile_counter_update(&osfp_profile_result_export, c2 - c1);
@@ -157,9 +153,6 @@ exit:
 void osfp_result_free(struct osfp_result *result)
 {
     if (result) {
-        if (result->json_str) {
-            free(result->json_str);
-        }
         free(result);
     }
 }

src/osfp_common.h

@@ -182,7 +182,6 @@ struct osfp_result_detail {
  * @brief 结构体用于表示操作系统识别结果。
  */
 struct osfp_result {
-    char *json_str;                              // JSON 字符串
     enum osfp_os_class_id likely_os_class;        // 最可能的操作系统类别
     struct osfp_result_detail details[OSFP_OS_CLASS_MAX];   // 详细结果数组
     const char *matched;                        // 精确匹配到的指纹特征

src/osfp_score_db.c

@@ -408,6 +408,7 @@ static int osfp_score_db_load_entry(struct osfp_score_db *score_db, cJSON *entry
     } else {
         // TODO: same fingerprints with different os should not insert into prefilter hash table, now just tag
         element->repeated++;
+        free(fp);
     }
 
     // field score db

src/osfp_score_db.h

@@ -42,7 +42,6 @@ struct osfp_score_db {
     unsigned int entry_count;
     unsigned int os_entry_count[OSFP_OS_CLASS_MAX];
 
-    unsigned int perfect_score;
     unsigned int total_weight;
     unsigned int field_weight[OSFP_FIELD_MAX];
 

test/test.c

@@ -265,6 +265,7 @@ void test_miss_rate()
             char *result_json = osfp_result_score_detail_export(result);
             if (result_json) {
                 fprintf(log_file_ptr, "%s\n", result_json);
+                free(result_json);
             } else {
                 fprintf(log_file_ptr, "result detail error:%p\n", result);
             }