- Ignore unknown frame streams control fields.

diff --git a/dnstap/dtstream.c b/dnstap/dtstream.c
index 171fe1c122022c4fc63c736c1be6db7ab457b64b..bface6b06ba843f4c9486e8d44412c658456b38b 100644 (file)
--- a/dnstap/dtstream.c
+++ b/dnstap/dtstream.c
@@ -71,6 +71,8 @@
 
 /** maximum length of received frame */
 #define DTIO_RECV_FRAME_MAX_LEN 1000
+/** lentgh of the ACCEPT frame with DNSTAP content type */
+#define DNSTAP_ACCEPT_FRAME_LEN 4+4+4+strlen(DNSTAP_CONTENT_TYPE)
 
 struct stop_flush_info;
 /** DTIO command channel commands */
@@ -1004,6 +1006,7 @@ static int dtio_check_close(struct dt_io_thread* dtio)
 static int dtio_read_accept_frame(struct dt_io_thread* dtio)
 {
        int r;
+       size_t read_frame_done;
        while(dtio->read_frame.frame_len_done < 4) {
 #ifdef HAVE_SSL
                if(dtio->ssl) {
@@ -1092,23 +1095,38 @@ static int dtio_read_accept_frame(struct dt_io_thread* dtio)
                dtio_read_frame_free(&dtio->read_frame);
                return -1;
        }
-
-       if(dtio->read_frame.frame_len != 4+4+4+strlen(DNSTAP_CONTENT_TYPE) ||
-               memcmp(dtio->read_frame.buf+4+4+4, DNSTAP_CONTENT_TYPE,
-                       strlen(DNSTAP_CONTENT_TYPE)) != 0) {
-               verbose(VERB_OPS, "dnstap: invalid content type on ACCEPT "
-                       "frame");
-               goto close_connection;
-       }
-
-       if(!dtio_control_start_send(dtio)) {
-               verbose(VERB_OPS, "dnstap io: out of memory while sending "
-                       "START frame");
-               goto close_connection;
+       read_frame_done = 4; /* control frame type */
+
+       /* Iteratate over control fields, ignore unknown types.
+        * Need to be able to read at least 2 bytes (control field type +
+        * length). */
+       while(read_frame_done+8 < dtio->read_frame.frame_len) {
+               uint32_t type = sldns_read_uint32(dtio->read_frame.buf +
+                       read_frame_done);
+               uint32_t len = sldns_read_uint32(dtio->read_frame.buf +
+                       read_frame_done + 4);
+               if(type == FSTRM_CONTROL_FIELD_TYPE_CONTENT_TYPE) {
+                       if(len == strlen(DNSTAP_CONTENT_TYPE) &&
+                               read_frame_done+8+len <=
+                               dtio->read_frame.frame_len &&
+                               memcmp(dtio->read_frame.buf + read_frame_done +
+                                       + 8, DNSTAP_CONTENT_TYPE, len) == 0) {
+                               if(!dtio_control_start_send(dtio)) {
+                                       verbose(VERB_OPS, "dnstap io: out of "
+                                        "memory while sending START frame");
+                                       goto close_connection;
+                               }
+                               dtio->accept_frame_received = 1;
+                               return 1;
+                       } else {
+                               /* unknow content type */
+                               goto close_connection;
+                       }
+               }
+               /* unknown option, try next */
+               read_frame_done += 8+len;
        }
 
-       dtio->accept_frame_received = 1;
-       return 1;
 
 close_connection:
        dtio_del_output_event(dtio);