Provide functionality do deal with tokens from JSMN.

Signed-off-by: Toni Uhlig <matzeton@googlemail.com>

2 files changed, 134 insertions, 12 deletions

diff --git a/dependencies/nDPIsrvd.h b/dependencies/nDPIsrvd.h
index 4889abfa9..dcadc61ca 100644
--- a/dependencies/nDPIsrvd.h
+++ b/dependencies/nDPIsrvd.h
@@ -43,6 +43,13 @@ struct nDPIsrvd_socket
         jsmntok_t tokens[128];
         int current_token;
         int tokens_found;
+        struct
+        {
+            char const * key;
+            int key_length;
+            char const * value;
+            int value_length;
+        } key_value;
     } jsmn;
 };
 
@@ -155,6 +162,68 @@ static inline enum nDPIsrvd_read_return nDPIsrvd_read(struct nDPIsrvd_socket * c
     return READ_OK;
 }
 
+static inline int token_is_key(struct nDPIsrvd_socket const * const sock)
+{
+    return sock->jsmn.current_token % 2;
+}
+
+static inline char const * token_get(struct nDPIsrvd_socket const * const sock)
+{
+    return sock->buffer.json_string + sock->jsmn.tokens[sock->jsmn.current_token].start;
+}
+
+static inline int token_size(struct nDPIsrvd_socket const * const sock)
+{
+    return sock->jsmn.tokens[sock->jsmn.current_token].end - sock->jsmn.tokens[sock->jsmn.current_token].start;
+}
+
+static inline int token_is_start(struct nDPIsrvd_socket const * const sock)
+{
+    return sock->jsmn.current_token == 0;
+}
+
+static inline int token_is_end(struct nDPIsrvd_socket const * const sock)
+{
+    return sock->jsmn.current_token == sock->jsmn.tokens_found;
+}
+
+static inline int token_is_key_value_pair(struct nDPIsrvd_socket const * const sock)
+{
+    return sock->jsmn.current_token > 0 && sock->jsmn.current_token < sock->jsmn.tokens_found;
+}
+
+static inline int token_is_jsmn_type(struct nDPIsrvd_socket const * const sock, jsmntype_t type_to_check)
+{
+    if (token_is_key_value_pair(sock) == 0)
+    {
+        return 0;
+    }
+
+    return sock->jsmn.tokens[sock->jsmn.current_token].type == type_to_check;
+}
+
+static inline int key_equals(struct nDPIsrvd_socket const * const sock, char const * const name)
+{
+    if (sock->jsmn.key_value.key == NULL || sock->jsmn.key_value.key_length == 0)
+    {
+        return 0;
+    }
+
+    return (int)strlen(name) == sock->jsmn.key_value.key_length &&
+           strncmp(name, sock->jsmn.key_value.key, sock->jsmn.key_value.key_length) == 0;
+}
+
+static inline int value_equals(struct nDPIsrvd_socket const * const sock, char const * const name)
+{
+    if (sock->jsmn.key_value.value == NULL || sock->jsmn.key_value.value_length == 0)
+    {
+        return 0;
+    }
+
+    return (int)strlen(name) == sock->jsmn.key_value.value_length &&
+           strncmp(name, sock->jsmn.key_value.value, sock->jsmn.key_value.value_length) == 0;
+}
+
 static inline enum nDPIsrvd_parse_return nDPIsrvd_parse(struct nDPIsrvd_socket * const sock,
                                                         json_callback cb,
                                                         void * user_data)
@@ -204,6 +273,10 @@ static inline enum nDPIsrvd_parse_return nDPIsrvd_parse(struct nDPIsrvd_socket *
             return PARSE_JSMN_ERROR;
         }
 
+        sock->jsmn.key_value.key = NULL;
+        sock->jsmn.key_value.key_length = 0;
+        sock->jsmn.key_value.value = NULL;
+        sock->jsmn.key_value.value_length = 0;
         sock->jsmn.current_token = 0;
         if (cb(sock, user_data) != CALLBACK_OK)
         {
@@ -213,9 +286,34 @@ static inline enum nDPIsrvd_parse_return nDPIsrvd_parse(struct nDPIsrvd_socket *
         for (sock->jsmn.current_token = 1; sock->jsmn.current_token < sock->jsmn.tokens_found;
              sock->jsmn.current_token++)
         {
-            if (cb(sock, user_data) != CALLBACK_OK)
+            if (token_is_key(sock) == 1)
             {
-                return PARSE_CALLBACK_ERROR;
+                sock->jsmn.key_value.key = token_get(sock);
+                sock->jsmn.key_value.key_length = token_size(sock);
+
+                if (sock->jsmn.key_value.key == NULL || sock->jsmn.key_value.value != NULL)
+                {
+                    return PARSE_JSMN_ERROR;
+                }
+            }
+            else
+            {
+                sock->jsmn.key_value.value = token_get(sock);
+                sock->jsmn.key_value.value_length = token_size(sock);
+
+                if (sock->jsmn.key_value.key == NULL || sock->jsmn.key_value.value == NULL)
+                {
+                    return PARSE_JSMN_ERROR;
+                }
+                if (cb(sock, user_data) != CALLBACK_OK)
+                {
+                    return PARSE_CALLBACK_ERROR;
+                }
+
+                sock->jsmn.key_value.key = NULL;
+                sock->jsmn.key_value.key_length = 0;
+                sock->jsmn.key_value.value = NULL;
+                sock->jsmn.key_value.value_length = 0;
             }
         }
 
@@ -224,6 +322,9 @@ static inline enum nDPIsrvd_parse_return nDPIsrvd_parse(struct nDPIsrvd_socket *
             return PARSE_CALLBACK_ERROR;
         }
 
+        sock->jsmn.current_token = -1;
+        sock->jsmn.tokens_found = 0;
+
         memmove(sock->buffer.raw,
                 sock->buffer.raw + sock->buffer.json_string_length,
                 sock->buffer.used - sock->buffer.json_string_length);
diff --git a/examples/c-captured/c-captured.c b/examples/c-captured/c-captured.c
index d2ca51c2c..4ddb9e1e7 100644
--- a/examples/c-captured/c-captured.c
+++ b/examples/c-captured/c-captured.c
@@ -10,6 +10,8 @@
 #include "nDPIsrvd.h"
 #include "jsmn/jsmn.h"
 
+//#define VERBOSE 1
+
 static char serv_listen_addr[INET_ADDRSTRLEN] = DISTRIBUTOR_HOST;
 static uint16_t serv_listen_port = DISTRIBUTOR_PORT;
 
@@ -17,26 +19,45 @@ static enum nDPIsrvd_callback_return nDPIsrvd_json_callback(struct nDPIsrvd_sock
 {
     (void)user_data;
 
-    if (sock->jsmn.current_token == 0) {
+    if (token_is_start(sock) == 1)
+    {
+#ifdef VERBOSE
         /* Start of a JSON string. */
         printf("JSON ");
+#endif
     }
-    else if (sock->jsmn.current_token == sock->jsmn.tokens_found)
+    else if (token_is_end(sock) == 1)
     {
+#ifdef VERBOSE
         /* End of a JSON string. */
-        printf(" EoF\n");
+        printf("EoF\n");
+#endif
     }
-    else if (sock->jsmn.current_token % 2 == 1)
+    else if (token_is_key_value_pair(sock) == 1)
     {
-        printf("[%.*s : ",
-               sock->jsmn.tokens[sock->jsmn.current_token].end - sock->jsmn.tokens[sock->jsmn.current_token].start,
-               sock->buffer.json_string + sock->jsmn.tokens[sock->jsmn.current_token].start);
+        if (key_equals(sock, "flow_event_name") == 1)
+        {
+            if (value_equals(sock, "guessed") == 1)
+            {
+                printf("Guessed flow.\n");
+            }
+            else if (value_equals(sock, "not-detected") == 1)
+            {
+                printf("Not detected flow.\n");
+            }
+        }
+#ifdef VERBOSE
+        printf("[%.*s : %.*s] ",
+               sock->jsmn.key_value.key_length,
+               sock->jsmn.key_value.key,
+               sock->jsmn.key_value.value_length,
+               sock->jsmn.key_value.value);
+#endif
     }
     else
     {
-        printf("%.*s] ",
-               sock->jsmn.tokens[sock->jsmn.current_token].end - sock->jsmn.tokens[sock->jsmn.current_token].start,
-               sock->buffer.json_string + sock->jsmn.tokens[sock->jsmn.current_token].start);
+        fprintf(stderr, "%s\n", "Internal error, exit ..");
+        return CALLBACK_ERROR;
     }
 
     return CALLBACK_OK;