Commit addition of transport list to the API.

- set and get functions are added.
- Existing transport functions retained for backwards compatibility.
- Basic combinations work as before, but underlying functional changes and cleanup are not complete yet...
- Context level options for timeouts and max_transactions_per_tcp_connection coming soon...

ChangeLog

@@ -1,5 +1,8 @@
 * 2015-06-??: Version 0.?.?
   * Unit test for spurious execute bits.  Thanks Paul Wouters.
+  * Added new transport list options in API. The option is now an ordered list of
+    GETDNS_TRANSPORT_UDP, GETDNS_TRANSPORT_TCP, GETDNS_TRANSPORT_TLS, 
+    GETDNS_TRANSPORT_STARTTLS.
 
 * 2015-05-21: Version 0.2.0
   * Fix libversion numbering:  Thanks Daniel Kahn Gillmor

spec/index.html

@@ -2198,6 +2198,20 @@ The value is <span class=default>
 <code>GETDNS_TRANSPORT_TLS_ONLY_KEEP_CONNECTIONS_OPEN></code>, or
 <code>GETDNS_TRANSPORT_TLS_FIRST_AND_FALL_BACK_TO_TCP_KEEP_CONNECTIONS_OPEN></code>
 
+<div class=forh>
+getdns_return_t
+getdns_context_set_dns_transport_list(
+  size_t              transport_list,
+  getdns_transport_list_t  *transports
+);</div>
+<p class=cont>The <code>transports</code> array contains an ordered list
+of transports that will be used for DNS lookups. The 
+values are <span class=default>
+<code>GETDNS_TRANSPORT_UDP</code></span>,
+<code>GETDNS_TRANSPORT_TCP</code>,
+<code>GETDNS_TRANSPORT_TLS></code>, or
+<code>GETDNS_TRANSPORT_STARTTLS></code>
+
 <div class=forh>
 getdns_return_t
 getdns_context_set_limit_outstanding_queries(

src/const-info.c

@@ -79,6 +79,11 @@ static struct const_info consts_info[] = {
 	{ 1100, "GETDNS_BAD_DNS_CNAME_IN_TARGET", GETDNS_BAD_DNS_CNAME_IN_TARGET_TEXT },
 	{ 1101, "GETDNS_BAD_DNS_ALL_NUMERIC_LABEL", GETDNS_BAD_DNS_ALL_NUMERIC_LABEL_TEXT },
 	{ 1102, "GETDNS_BAD_DNS_CNAME_RETURNED_FOR_OTHER_TYPE", GETDNS_BAD_DNS_CNAME_RETURNED_FOR_OTHER_TYPE_TEXT },
+	{ 1200, "GETDNS_TRANSPORT_UDP", GETDNS_TRANSPORT_UDP_TEXT },
+	{ 1201, "GETDNS_TRANSPORT_TCP", GETDNS_TRANSPORT_TCP_TEXT },
+	{ 1202, "GETDNS_TRANSPORT_TLS", GETDNS_TRANSPORT_TLS_TEXT },
+	{ 1203, "GETDNS_TRANSPORT_STARTTLS", GETDNS_TRANSPORT_STARTTLS_TEXT },
+
 };
 
 static int const_info_cmp(const void *a, const void *b)

src/context.c

@@ -102,7 +102,7 @@ static void cancel_outstanding_requests(struct getdns_context*, int);
 static getdns_return_t rebuild_ub_ctx(struct getdns_context* context);
 static void set_ub_string_opt(struct getdns_context *, char *, char *);
 static void set_ub_number_opt(struct getdns_context *, char *, uint16_t);
-static getdns_return_t set_ub_dns_transport(struct getdns_context*, getdns_transport_t);
+static getdns_return_t set_ub_dns_transport(struct getdns_context*);
 static void set_ub_limit_outstanding_queries(struct getdns_context*,
     uint16_t);
 static void set_ub_dnssec_allowed_skew(struct getdns_context*, uint32_t);
@@ -139,6 +139,44 @@ create_default_namespaces(struct getdns_context *context)
 	return GETDNS_RETURN_GOOD;
 }
 
+static getdns_transport_list_t *
+get_dns_transport_list(getdns_context *context, int *count)
+{
+    if (context == NULL) 
+		return NULL;
+
+	/* Count how many we have*/
+	for (*count = 0; *count < GETDNS_BASE_TRANSPORT_MAX; (*count)++) {
+		if (context->dns_base_transports[*count] == GETDNS_BASE_TRANSPORT_NONE)
+			break;
+	}
+
+    // use normal malloc here so users can do normal free
+    getdns_transport_list_t * transports = malloc(*count * sizeof(getdns_transport_list_t));
+
+	if(transports == NULL)
+		return NULL;
+    for (int i = 0; i < (int)*count; i++) {
+        switch(context->dns_base_transports[i]) {
+			case GETDNS_BASE_TRANSPORT_UDP:
+				transports[i] = GETDNS_TRANSPORT_UDP;
+				break;
+			case GETDNS_BASE_TRANSPORT_TCP:
+				transports[i] = GETDNS_TRANSPORT_TCP;
+				break;
+			case GETDNS_BASE_TRANSPORT_TLS:
+				transports[i] = GETDNS_TRANSPORT_TLS;
+				break;
+			case GETDNS_BASE_TRANSPORT_STARTTLS:
+				transports[i] = GETDNS_TRANSPORT_STARTTLS;
+				break;
+			default:
+				break;
+        }
+	}
+    return transports;
+}
+
 static inline void canonicalize_dname(uint8_t *dname)
 {
 	uint8_t *next_label;
@@ -834,8 +872,8 @@ getdns_context_create_with_extended_memory_functions(
 
 	result->dnssec_allowed_skew = 0;
 	result->edns_maximum_udp_payload_size = -1;
-	result->dns_transport = GETDNS_TRANSPORT_UDP_FIRST_AND_FALL_BACK_TO_TCP;
+	result->dns_base_transports[0] = GETDNS_BASE_TRANSPORT_UDP;
-	priv_set_base_dns_transports(result->dns_base_transports, result->dns_transport);
+	result->dns_base_transports[1] = GETDNS_BASE_TRANSPORT_TCP;
 	result->limit_outstanding_queries = 0;
 	result->has_ta = priv_getdns_parse_ta_file(NULL, NULL);
 	result->return_dnssec_status = GETDNS_EXTENSION_FALSE;
@@ -1065,8 +1103,7 @@ rebuild_ub_ctx(struct getdns_context* context) {
 		context->dnssec_allowed_skew);
 	set_ub_edns_maximum_udp_payload_size(context,
 		context->edns_maximum_udp_payload_size);
-	set_ub_dns_transport(context,
+	set_ub_dns_transport(context);
-		context->dns_transport);
 
 	/* Set default trust anchor */
 	if (context->has_ta) {
@@ -1159,71 +1196,67 @@ getdns_context_set_namespaces(struct getdns_context *context,
     return GETDNS_RETURN_GOOD;
 }               /* getdns_context_set_namespaces */
 
-/* TODO[TLS]: Modify further when API changed.*/
+static getdns_return_t
-getdns_return_t
+getdns_set_base_dns_transports(struct getdns_context *context,
-priv_set_base_dns_transports(getdns_base_transport_t *dns_base_transports,
+    size_t transport_count, getdns_transport_list_t *transports)
-                             getdns_transport_t value)
 {
+    RETURN_IF_NULL(context, GETDNS_RETURN_INVALID_PARAMETER);
     for (int i = 0; i < GETDNS_BASE_TRANSPORT_MAX; i++)
-        dns_base_transports[i] = GETDNS_BASE_TRANSPORT_NONE;
+        context->dns_base_transports[i] = GETDNS_BASE_TRANSPORT_NONE;
-    switch (value) {
-        case GETDNS_TRANSPORT_UDP_FIRST_AND_FALL_BACK_TO_TCP:
-            dns_base_transports[0] = GETDNS_BASE_TRANSPORT_UDP;
-            dns_base_transports[1] = GETDNS_BASE_TRANSPORT_TCP_SINGLE;
-            break;
-        case GETDNS_TRANSPORT_UDP_ONLY:
-            dns_base_transports[0] = GETDNS_BASE_TRANSPORT_UDP;
-            break;
-        case GETDNS_TRANSPORT_TCP_ONLY:
-            dns_base_transports[0] = GETDNS_BASE_TRANSPORT_TCP_SINGLE;
-            break;
-        case GETDNS_TRANSPORT_TCP_ONLY_KEEP_CONNECTIONS_OPEN:
-            dns_base_transports[0] = GETDNS_BASE_TRANSPORT_TCP;
-            break;
-        case GETDNS_TRANSPORT_TLS_ONLY_KEEP_CONNECTIONS_OPEN:
-            dns_base_transports[0] = GETDNS_BASE_TRANSPORT_TLS;
-            break;
-        case GETDNS_TRANSPORT_TLS_FIRST_AND_FALL_BACK_TO_TCP_KEEP_CONNECTIONS_OPEN:
-            dns_base_transports[0] = GETDNS_BASE_TRANSPORT_TLS;
-            dns_base_transports[1] = GETDNS_BASE_TRANSPORT_TCP;
-           break;
-        case GETDNS_TRANSPORT_STARTTLS_FIRST_AND_FALL_BACK_TO_TCP_KEEP_CONNECTIONS_OPEN:
-            dns_base_transports[0] = GETDNS_BASE_TRANSPORT_STARTTLS;
-            dns_base_transports[1] = GETDNS_BASE_TRANSPORT_TCP;
-           break;
 
+    if ((int)transport_count == 0 || transports == NULL || 
+        (int)transport_count > GETDNS_BASE_TRANSPORT_MAX) {
+        return GETDNS_RETURN_CONTEXT_UPDATE_FAIL;
+    }
+
+	for (size_t j = 0; j < transport_count; j++) {
+        switch(transports[j]) {
+			case GETDNS_TRANSPORT_UDP:
+				context->dns_base_transports[j] = GETDNS_BASE_TRANSPORT_UDP;
+				break;
+			case GETDNS_TRANSPORT_TCP:
+				context->dns_base_transports[j] = GETDNS_BASE_TRANSPORT_TCP;
+				break;
+			case GETDNS_TRANSPORT_TLS:
+				context->dns_base_transports[j] = GETDNS_BASE_TRANSPORT_TLS;
+				break;
+			case GETDNS_TRANSPORT_STARTTLS:
+				context->dns_base_transports[j] = GETDNS_BASE_TRANSPORT_STARTTLS;
+				break;
 			default:
 				return GETDNS_RETURN_CONTEXT_UPDATE_FAIL;
         }
+	}
     return GETDNS_RETURN_GOOD;
 }
 
 static getdns_return_t
-set_ub_dns_transport(struct getdns_context* context,
+set_ub_dns_transport(struct getdns_context* context) {
-    getdns_transport_t value) {
+    /* These mappings are not exact because Unbound is configured differently,
-    switch (value) {
+       so just map as close as possible from the first 1 or 2 transports. */
-        case GETDNS_TRANSPORT_UDP_FIRST_AND_FALL_BACK_TO_TCP:
+    switch (context->dns_base_transports[0]) {
+        case GETDNS_BASE_TRANSPORT_UDP:
             set_ub_string_opt(context, "do-udp:", "yes");
+            if (context->dns_base_transports[1] == GETDNS_BASE_TRANSPORT_TCP)
                 set_ub_string_opt(context, "do-tcp:", "yes");
-            break;
+            else
-        case GETDNS_TRANSPORT_UDP_ONLY:
-            set_ub_string_opt(context, "do-udp:", "yes");
                 set_ub_string_opt(context, "do-tcp:", "no");
             break;
-        case GETDNS_TRANSPORT_TCP_ONLY:
+        case GETDNS_BASE_TRANSPORT_TLS:
-        /* Note: no pipelining available directly in unbound.*/
+            /* Note: If TLS is used in recursive mode this will try TLS on port 
-        case GETDNS_TRANSPORT_TCP_ONLY_KEEP_CONNECTIONS_OPEN:
+             * 53... So this is prohibited when preparing for resolution.*/
+            if (context->dns_base_transports[1] == GETDNS_BASE_TRANSPORT_NONE) {
+                set_ub_string_opt(context, "ssl-upstream:", "yes");
                 set_ub_string_opt(context, "do-udp:", "no");
                 set_ub_string_opt(context, "do-tcp:", "yes");
                 break;
-       case GETDNS_TRANSPORT_TLS_ONLY_KEEP_CONNECTIONS_OPEN:
+            }
-            /* Note: If TLS is used in recursive mode this will try TLS on port 
+            if (context->dns_base_transports[1] != GETDNS_BASE_TRANSPORT_TCP)
-             * 53... So this is prohibited when preparing for resolution.*/
+                break;
-            set_ub_string_opt(context, "ssl-upstream:", "yes");
+            /* Fallthrough */
-            /* Fall through */
+        case GETDNS_BASE_TRANSPORT_STARTTLS:
-       case GETDNS_TRANSPORT_TLS_FIRST_AND_FALL_BACK_TO_TCP_KEEP_CONNECTIONS_OPEN:
+        case GETDNS_BASE_TRANSPORT_TCP:
-       case GETDNS_TRANSPORT_STARTTLS_FIRST_AND_FALL_BACK_TO_TCP_KEEP_CONNECTIONS_OPEN:
+           /* Note: no STARTTLS or fallback to TCP available directly in unbound, so we just
-           /* Note: no fallback to TCP available directly in unbound, so we just
             * use TCP for now to make sure the messages are sent. */
            set_ub_string_opt(context, "do-udp:", "no");
            set_ub_string_opt(context, "do-tcp:", "yes");
@@ -1242,25 +1275,71 @@ getdns_return_t
 getdns_context_set_dns_transport(struct getdns_context *context,
     getdns_transport_t value)
 {
-    /* TODO[TLS]: Modify further when API changed.*/
     RETURN_IF_NULL(context, GETDNS_RETURN_INVALID_PARAMETER);
+
+    for (int i = 0; i < GETDNS_BASE_TRANSPORT_MAX; i++)
+        context->dns_base_transports[i] = GETDNS_BASE_TRANSPORT_NONE;
+
+    switch (value) {
+        case GETDNS_TRANSPORT_UDP_FIRST_AND_FALL_BACK_TO_TCP:
+            context->dns_base_transports[0] = GETDNS_BASE_TRANSPORT_UDP;
+            context->dns_base_transports[1] = GETDNS_BASE_TRANSPORT_TCP;
+            break;
+        case GETDNS_TRANSPORT_UDP_ONLY:
+            context->dns_base_transports[0] = GETDNS_BASE_TRANSPORT_UDP;
+            break;
+        case GETDNS_TRANSPORT_TCP_ONLY:
+        case GETDNS_TRANSPORT_TCP_ONLY_KEEP_CONNECTIONS_OPEN:
+            context->dns_base_transports[0] = GETDNS_BASE_TRANSPORT_TCP;
+            break;
+        case GETDNS_TRANSPORT_TLS_ONLY_KEEP_CONNECTIONS_OPEN:
+            context->dns_base_transports[0] = GETDNS_BASE_TRANSPORT_TLS;
+            break;
+        case GETDNS_TRANSPORT_TLS_FIRST_AND_FALL_BACK_TO_TCP_KEEP_CONNECTIONS_OPEN:
+            context->dns_base_transports[0] = GETDNS_BASE_TRANSPORT_TLS;
+            context->dns_base_transports[1] = GETDNS_BASE_TRANSPORT_TCP;
+           break;
+        case GETDNS_TRANSPORT_STARTTLS_FIRST_AND_FALL_BACK_TO_TCP_KEEP_CONNECTIONS_OPEN:
+            context->dns_base_transports[0] = GETDNS_BASE_TRANSPORT_STARTTLS;
+            context->dns_base_transports[1] = GETDNS_BASE_TRANSPORT_TCP;
+           break;
+       default:
+           return GETDNS_RETURN_CONTEXT_UPDATE_FAIL;
+        }
     /* Note that the call below does not have any effect in unbound after the
      * ctx is finalised so for recursive mode or stub + dnssec only the first
      * transport specified on the first query is used.
      * However the method returns success as otherwise the transport could not
      * be reset for stub mode.
      * Also, not all transport options supported in libunbound yet */
-    if (set_ub_dns_transport(context, value) != GETDNS_RETURN_GOOD) {
+    if (set_ub_dns_transport(context) != GETDNS_RETURN_GOOD) {
         return GETDNS_RETURN_CONTEXT_UPDATE_FAIL;
     }
-    if (value != context->dns_transport) {
-        /*TODO[TLS]: remove this line when API updated*/
-        context->dns_transport = value;
-        if (priv_set_base_dns_transports(context->dns_base_transports, value) != GETDNS_RETURN_GOOD)
-            return GETDNS_RETURN_CONTEXT_UPDATE_FAIL;
     dispatch_updated(context, GETDNS_CONTEXT_CODE_DNS_TRANSPORT);
-    }
+    return GETDNS_RETURN_GOOD;
+}
 
+/*
+ * getdns_context_set_dns_transport
+ *
+ */
+getdns_return_t
+getdns_context_set_dns_transport_list(getdns_context *context,
+    size_t transport_count, getdns_transport_list_t *transports)
+{
+    RETURN_IF_NULL(context, GETDNS_RETURN_INVALID_PARAMETER);
+    if (getdns_set_base_dns_transports(context, transport_count, transports) != GETDNS_RETURN_GOOD)
+        return GETDNS_RETURN_CONTEXT_UPDATE_FAIL;
+    /* Note that the call below does not have any effect in unbound after the
+     * ctx is finalised so for recursive mode or stub + dnssec only the first
+     * transport specified on the first query is used.
+     * However the method returns success as otherwise the transport could not
+     * be reset for stub mode.
+     * Also, not all transport options supported in libunbound yet */
+    if (set_ub_dns_transport(context) != GETDNS_RETURN_GOOD) {
+        return GETDNS_RETURN_CONTEXT_UPDATE_FAIL;
+    }
+    dispatch_updated(context, GETDNS_CONTEXT_CODE_DNS_TRANSPORT);
     return GETDNS_RETURN_GOOD;
 }               /* getdns_context_set_dns_transport */
 
@@ -1568,7 +1647,7 @@ getdns_context_set_upstream_recursive_servers(struct getdns_context *context,
 			if (base_transport != GETDNS_BASE_TRANSPORT_TLS)
 				(void) getdns_dict_get_int(dict, "port", &port);
 			else
-				(void) getdns_dict_get_int(dict, "tls-port", &port);
+				(void) getdns_dict_get_int(dict, "tls_port", &port);
 			(void) snprintf(portstr, 1024, "%d", (int)port);
 
 			if (getaddrinfo(addrstr, portstr, &hints, &ai))
@@ -1918,17 +1997,14 @@ getdns_context_prepare_for_resolution(struct getdns_context *context,
 			/* Create client context, use TLS v1.2 only for now */
 			context->tls_ctx = SSL_CTX_new(TLSv1_2_client_method());
 #endif
-			/* TODO[TLS]: Check if TLS is the only option in the list*/
+			if(context->tls_ctx == NULL)
-			// if(!context->tls_ctx && context->dns_transport == 
+				return GETDNS_RETURN_BAD_CONTEXT;
-			//    GETDNS_TRANSPORT_TLS_ONLY_KEEP_CONNECTIONS_OPEN) {
-			// 	return GETDNS_RETURN_BAD_CONTEXT;
-			// }
 		}
 	}
 	/* Block use of TLS ONLY in recursive mode as it won't work */
-	/* TODO[TLS]: Check if TLS is the only option in the list*/
 	if (context->resolution_type == GETDNS_RESOLUTION_RECURSING &&
-	    context->dns_transport == GETDNS_TRANSPORT_TLS_ONLY_KEEP_CONNECTIONS_OPEN)
+	    context->dns_base_transports[0] == GETDNS_BASE_TRANSPORT_TLS &&
+	    context->dns_base_transports[1] == GETDNS_BASE_TRANSPORT_NONE)
 		return GETDNS_RETURN_BAD_CONTEXT;
 
 	if (context->resolution_type_set == context->resolution_type)
@@ -2192,8 +2268,7 @@ priv_get_context_settings(getdns_context* context) {
         return NULL;
     }
     /* int fields */
-    r = getdns_dict_set_int(result, "dns_transport", context->dns_transport);
+    r = getdns_dict_set_int(result, "timeout", context->timeout);
-    r |= getdns_dict_set_int(result, "timeout", context->timeout);
     r |= getdns_dict_set_int(result, "limit_outstanding_queries", context->limit_outstanding_queries);
     r |= getdns_dict_set_int(result, "dnssec_allowed_skew", context->dnssec_allowed_skew);
     r |= getdns_dict_set_int(result, "follow_redirects", context->follow_redirects);
@@ -2224,6 +2299,18 @@ priv_get_context_settings(getdns_context* context) {
 		    upstreams);
 		getdns_list_destroy(upstreams);
 	}
+    /* create a transport list */
+    getdns_list* transports = getdns_list_create_with_context(context);
+    if (transports) {
+		int transport_count;
+		getdns_transport_list_t *transport_list =
+		           get_dns_transport_list(context, &transport_count);
+        for (int i = 0; i < transport_count; i++) {
+            r |= getdns_list_set_int(transports, i, transport_list[i]);
+        }
+        r |= getdns_dict_set_list(result, "dns_transport_list", transports);
+		free(transport_list);
+    }
     if (context->namespace_count > 0) {
         /* create a namespace list */
         size_t i;
@@ -2416,10 +2503,60 @@ getdns_context_get_dns_transport(getdns_context *context,
     getdns_transport_t* value) {
     RETURN_IF_NULL(context, GETDNS_RETURN_INVALID_PARAMETER);
     RETURN_IF_NULL(value, GETDNS_RETURN_INVALID_PARAMETER);
-    *value = context->dns_transport;
+	int count;
+	getdns_transport_list_t *transport_list =
+	           get_dns_transport_list(context, &count);
+	if (!count) 
+		return GETDNS_RETURN_WRONG_TYPE_REQUESTED;
+
+	/* Best effort mapping for backwards compatibility*/
+	if (transport_list[0] == GETDNS_TRANSPORT_UDP) {
+		if (count == 1) 
+			*value = GETDNS_TRANSPORT_UDP_ONLY;
+		else if (count == 2 && transport_list[1] == GETDNS_TRANSPORT_TCP)
+			*value = GETDNS_TRANSPORT_UDP_FIRST_AND_FALL_BACK_TO_TCP;
+		else
+			return GETDNS_RETURN_WRONG_TYPE_REQUESTED;
+	}
+	if (transport_list[0] == GETDNS_TRANSPORT_TCP) {
+		if (count == 1)	
+			*value = GETDNS_TRANSPORT_TCP_ONLY_KEEP_CONNECTIONS_OPEN;
+	}
+	if (transport_list[0] == GETDNS_TRANSPORT_TLS) {
+		if (count == 1)	
+			*value = GETDNS_TRANSPORT_TLS_ONLY_KEEP_CONNECTIONS_OPEN;
+		else if (count == 2 && transport_list[1] == GETDNS_TRANSPORT_TCP)
+			*value = GETDNS_TRANSPORT_TLS_FIRST_AND_FALL_BACK_TO_TCP_KEEP_CONNECTIONS_OPEN;
+		else
+			return GETDNS_RETURN_WRONG_TYPE_REQUESTED;
+	}
+	if (transport_list[0] == GETDNS_TRANSPORT_STARTTLS) {
+		if (count == 2 && transport_list[1] == GETDNS_TRANSPORT_TCP)
+			*value = GETDNS_TRANSPORT_STARTTLS_FIRST_AND_FALL_BACK_TO_TCP_KEEP_CONNECTIONS_OPEN;
+		else
+			return GETDNS_RETURN_WRONG_TYPE_REQUESTED;
+	}
     return GETDNS_RETURN_GOOD;
 }
 
+getdns_return_t
+getdns_context_get_dns_transport_list(getdns_context *context,
+    size_t* transport_count, getdns_transport_list_t **transports) {
+    RETURN_IF_NULL(context, GETDNS_RETURN_INVALID_PARAMETER);
+    RETURN_IF_NULL(transport_count, GETDNS_RETURN_INVALID_PARAMETER);
+    RETURN_IF_NULL(transports, GETDNS_RETURN_INVALID_PARAMETER);
+
+	int count;
+	getdns_transport_list_t *transport_list =
+	           get_dns_transport_list(context, &count);
+    *transport_count = count;
+    if (!transport_count) {
+        *transports = NULL;
+        return GETDNS_RETURN_GOOD;
+    }
+	*transports = transport_list;
+    return GETDNS_RETURN_GOOD;
+}
 
 getdns_return_t
 getdns_context_get_limit_outstanding_queries(getdns_context *context,

src/context.h

@@ -137,7 +137,6 @@ struct getdns_context {
 	struct getdns_list   *suffix;
 	struct getdns_list   *dnssec_trust_anchors;
 	getdns_upstreams     *upstreams;
-	getdns_transport_t   dns_transport;
 	getdns_base_transport_t dns_base_transports[GETDNS_BASE_TRANSPORT_MAX];
 	uint16_t             limit_outstanding_queries;
 	uint32_t             dnssec_allowed_skew;
@@ -234,9 +233,6 @@ int filechg_check(struct getdns_context *context, struct filechg *fchg);
 
 void priv_getdns_context_ub_read_cb(void *userarg);
 
-getdns_return_t priv_set_base_dns_transports(getdns_base_transport_t *,
-    getdns_transport_t);
-
 void priv_getdns_upstreams_dereference(getdns_upstreams *upstreams);
 
 #endif /* _GETDNS_CONTEXT_H_ */

src/dict.c

@@ -608,14 +608,14 @@ static const char *unknown_str_l[] = {" <unknown>", " null", "null"};
  * @param buf    buffer to write to
  * @param indent number of spaces to append after newline
  * @param list   the to list print
- * @param for_namespaces The list is a list of namespace literals.
+ * @param for_literals The list is a list of literals.
  *               Show the literal instead of the value.
  * @return       on success the number of written characters
  *               if an output error is encountered, a negative value
  */
 static int
 getdns_pp_list(gldns_buffer *buf, size_t indent, const getdns_list *list,
-    int for_namespaces, int json)
+    int for_literals, int json)
 {
 	size_t i, length, p = gldns_buffer_position(buf);
 	getdns_data_type dtype;
@@ -651,7 +651,7 @@ getdns_pp_list(gldns_buffer *buf, size_t indent, const getdns_list *list,
 
 			if (getdns_list_get_int(list, i, &int_item))
 				return -1;
-			if (!json && for_namespaces &&
+			if (!json && for_literals &&
 			    (strval =
 			     priv_getdns_get_const_info(int_item)->name)) {
 				if (gldns_buffer_printf(buf, "%s", strval) < 0)
@@ -829,7 +829,6 @@ getdns_pp_dict(gldns_buffer * buf, size_t indent,
 			     strcmp(item->node.key, "dnssec_status") == 0 ||
 			     strcmp(item->node.key, "status") == 0 ||
 			     strcmp(item->node.key, "append_name") == 0 ||
-			     strcmp(item->node.key, "dns_transport") == 0 ||
 			     strcmp(item->node.key, "follow_redirects") == 0 ||
 			     strcmp(item->node.key, "resolution_type") == 0) &&
 			    (strval =
@@ -893,7 +892,8 @@ getdns_pp_dict(gldns_buffer * buf, size_t indent,
 			    getdns_indent(indent)) < 0)
 				return -1;
 			if (getdns_pp_list(buf, indent, item->data.list, 
-			    (strcmp(item->node.key, "namespaces") == 0),
+			    (strcmp(item->node.key, "namespaces") == 0 ||
+			     strcmp(item->node.key, "dns_transport_list") == 0),
 			    json) < 0)
 				return -1;
 			break;

src/getdns/getdns.h.in

@@ -180,6 +180,26 @@ typedef enum getdns_transport_t {
 #define GETDNS_TRANSPORT_TLS_ONLY_KEEP_CONNECTIONS_OPEN_TEXT "See getdns_context_set_dns_transport()"
 #define GETDNS_TRANSPORT_TLS_FIRST_AND_FALL_BACK_TO_TCP_KEEP_CONNECTIONS_OPEN_TEXT "See getdns_context_set_dns_transport()"
 #define GETDNS_TRANSPORT_STARTTLS_FIRST_AND_FALL_BACK_TO_TCP_KEEP_CONNECTIONS_OPEN_TEXT "See getdns_context_set_dns_transport()"
+/** @}
+*/
+
+
+/* Base transports for use in transport list */
+typedef enum getdns_transport_list_t {
+	GETDNS_TRANSPORT_UDP = 1200,
+	GETDNS_TRANSPORT_TCP = 1201,
+	GETDNS_TRANSPORT_TLS = 1202,
+	GETDNS_TRANSPORT_STARTTLS = 1203
+} getdns_transport_list_t;
+
+/**
+ * \defgroup Base transport texts
+ * @{
+ */
+#define GETDNS_TRANSPORT_UDP_TEXT "See getdns_context_set_dns_transport()"
+#define GETDNS_TRANSPORT_TCP_TEXT "See getdns_context_set_dns_transport()"
+#define GETDNS_TRANSPORT_TLS_TEXT "See getdns_context_set_dns_transport()"
+#define GETDNS_TRANSPORT_STARTTLS_TEXT "See getdns_context_set_dns_transport()"
 /** @}
  */
 
@@ -942,6 +962,10 @@ getdns_return_t
 getdns_context_set_dns_transport(getdns_context *context,
     getdns_transport_t value);
 
+getdns_return_t
+getdns_context_set_dns_transport_list(getdns_context *context,
+    size_t transport_count, getdns_transport_list_t *transports);
+
 getdns_return_t
 getdns_context_set_limit_outstanding_queries(getdns_context *context,
     uint16_t limit);

src/getdns/getdns_extra.h

@@ -139,6 +139,10 @@ getdns_return_t
 getdns_context_get_dns_transport(getdns_context *context,
     getdns_transport_t* value);
 
+getdns_return_t
+getdns_context_get_dns_transport_list(getdns_context *context,
+    size_t* transport_count, getdns_transport_list_t **transports);
+
 getdns_return_t
 getdns_context_get_limit_outstanding_queries(getdns_context *context,
     uint16_t* limit);

src/libgetdns.symbols

@@ -12,6 +12,7 @@ getdns_context_get_dns_root_servers
 getdns_context_get_dnssec_allowed_skew
 getdns_context_get_dnssec_trust_anchors
 getdns_context_get_dns_transport
+getdns_context_get_dns_transport_list
 getdns_context_get_edns_do_bit
 getdns_context_get_edns_extended_rcode
 getdns_context_get_edns_maximum_udp_payload_size
@@ -33,6 +34,7 @@ getdns_context_set_dns_root_servers
 getdns_context_set_dnssec_allowed_skew
 getdns_context_set_dnssec_trust_anchors
 getdns_context_set_dns_transport
+getdns_context_set_dns_transport_list
 getdns_context_set_edns_do_bit
 getdns_context_set_edns_extended_rcode
 getdns_context_set_edns_maximum_udp_payload_size

src/stub.c

@@ -530,6 +530,7 @@ stub_timeout_cb(void *userarg)
 		netreq->upstream->tls_hs_state = GETDNS_HS_FAILED;
 		stub_next_upstream(netreq);
 		stub_cleanup(netreq);
+		return;
 	}
 
 	stub_next_upstream(netreq);
@@ -1049,10 +1050,11 @@ stub_udp_read_cb(void *userarg)
 		return; /* Client cookie didn't match? */
 
 	close(netreq->fd);
-	/*TODO[TLS]: Switch this to use the transport fallback list*/
+	/* TODO: check not past end of transports*/
+	getdns_base_transport_t next_transport = 
+	                         netreq->dns_base_transports[netreq->transport + 1];
 	if (GLDNS_TC_WIRE(netreq->response) &&
-	    dnsreq->context->dns_transport ==
+	    next_transport == GETDNS_BASE_TRANSPORT_TCP) {
-	    GETDNS_TRANSPORT_UDP_FIRST_AND_FALL_BACK_TO_TCP) {
 
 		if ((netreq->fd = socket(
 		    upstream->addr.ss_family, SOCK_STREAM, IPPROTO_TCP)) == -1)

src/test/getdns_query.c

@@ -32,6 +32,7 @@
 #include <dirent.h>
 #include <getdns/getdns.h>
 #include <getdns/getdns_extra.h>
+#include <types-internal.h>
 
 static int quiet = 0;
 static int batch_mode = 0;
@@ -92,13 +93,40 @@ ipaddr_dict(getdns_context *context, char *ipstr)
 	if (*portstr)
 		getdns_dict_set_int(r, "port", (int32_t)atoi(portstr));
 	if (*tls_portstr)
-		getdns_dict_set_int(r, "tls-port", (int32_t)atoi(tls_portstr));
+		getdns_dict_set_int(r, "tls_port", (int32_t)atoi(tls_portstr));
 	if (*scope_id_str)
 		getdns_dict_util_set_string(r, "scope_id", scope_id_str);
 
 	return r;
 }
 
+static getdns_return_t
+fill_transport_list(getdns_context *context, char *transport_list_str, 
+                    getdns_transport_list_t *transports, size_t *transport_count)
+{
+	for (size_t i = 0; i < strlen(transport_list_str); i++, (*transport_count)++) {
+		switch(*(transport_list_str + i)) {
+			case 'U': 
+				transports[i] = GETDNS_TRANSPORT_UDP;
+				break;
+			case 'T': 
+				transports[i] = GETDNS_TRANSPORT_TCP;
+				break;
+			case 'L': 
+				transports[i] = GETDNS_TRANSPORT_TLS;
+				break;
+			case 'S': 
+				transports[i] = GETDNS_TRANSPORT_STARTTLS;
+				break;
+			default:
+				fprintf(stderr, "Unrecognised transport '%c' in string %s\n", 
+				       *(transport_list_str + i), transport_list_str);
+				return GETDNS_RETURN_GENERIC_ERROR;
+		}
+	}
+	return GETDNS_RETURN_GOOD;
+}
+
 void
 print_usage(FILE *out, const char *progname)
 {
@@ -131,6 +159,8 @@ print_usage(FILE *out, const char *progname)
 	fprintf(out, "\t-R\tSet transport to STARTTLS with TCP fallback only keep connections open\n");
 	fprintf(out, "\t-u\tSet transport to UDP with TCP fallback\n");
 	fprintf(out, "\t-U\tSet transport to UDP only\n");
+	fprintf(out, "\t-l <transports>\tSet transport list. List can contain 1 of each of the characters\n");
+	fprintf(out, "\t\t\t U T L S for UDP, TCP, TLS or STARTTLS e.g 'UT' or 'LST' \n");
 	fprintf(out, "\t-B\tBatch mode. Schedule all messages before processing responses.\n");
 	fprintf(out, "\t-q\tQuiet mode - don't print response\n");
 }
@@ -389,6 +419,21 @@ getdns_return_t parse_args(int argc, char **argv)
 				getdns_context_set_dns_transport(context,
 				    GETDNS_TRANSPORT_UDP_ONLY);
 				break;
+			case 'l':
+				if (c[1] != 0 || ++i >= argc || !*argv[i]) {
+					fprintf(stderr, "transport list expected "
+					    "after -l\n");
+					return GETDNS_RETURN_GENERIC_ERROR;
+				}
+				size_t transport_count = 0;
+				getdns_transport_list_t transports[GETDNS_BASE_TRANSPORT_MAX];
+				if ((r = fill_transport_list(context, argv[i], transports, &transport_count)) ||
+				    (r = getdns_context_set_dns_transport_list(context, 
+				                                               transport_count, transports))){
+						fprintf(stderr, "Could not set transports\n");
+						return r;
+				}
+				break;
 			case 'B':
 				batch_mode = 1;
 			break;

src/test/tests_stub_async.c

@@ -42,10 +42,12 @@
 #include <sys/time.h>
 
 #define TRANSPORT_UDP "udp"
+#define TRANSPORT_UDP_TCP "udp_tcp"
 #define TRANSPORT_TCP "tcp"
 #define TRANSPORT_PIPELINE "pipeline"
 #define TRANSPORT_TLS_KEEPOPEN "tls"
 #define TRANSPORT_TLS_TCP_KEEPOPEN "dns-over-tls"
+#define TRANSPORT_STARTTLS_TCP_KEEPOPEN "starttls"
 #define RESOLUTION_STUB "stub"
 #define RESOLUTION_REC "rec"
 
@@ -76,16 +78,16 @@ int
 main(int argc, char** argv)
 {
 
-	const char *transport = argc > 2 ? argv[2] : "udp";
+	const char *transport = argc > 2 ? argv[2] : "udp_tcp";
 	const char *resolution = argc > 3 ? argv[3] : "stub";
 
 	/* Create the DNS context for this call */
 	struct getdns_context *this_context = NULL;
-	getdns_return_t context_create_return =
+	getdns_return_t return_value =
 		getdns_context_create(&this_context, 1);
-	if (context_create_return != GETDNS_RETURN_GOOD) {
+	if (return_value != GETDNS_RETURN_GOOD) {
 		fprintf(stderr, "Trying to create the context failed: %d",
-			context_create_return);
+			return_value);
 		return (GETDNS_RETURN_GENERIC_ERROR);
 	}
 
@@ -96,16 +98,23 @@ main(int argc, char** argv)
 		exit(EXIT_FAILURE);
 	}
 
+	/* Order matters*/
 	if (strncmp(transport, TRANSPORT_TCP, 3) == 0)
 		getdns_context_set_dns_transport(this_context, GETDNS_TRANSPORT_TCP_ONLY);
+	else if (strncmp(transport, TRANSPORT_UDP_TCP, 7) == 0)
+		getdns_context_set_dns_transport(this_context, GETDNS_TRANSPORT_UDP_FIRST_AND_FALL_BACK_TO_TCP);
+	else if (strncmp(transport, TRANSPORT_UDP, 3) == 0)
+		getdns_context_set_dns_transport(this_context, GETDNS_TRANSPORT_UDP_ONLY);
 	else if (strncmp(transport, TRANSPORT_PIPELINE, 8) == 0)
 		getdns_context_set_dns_transport(this_context, GETDNS_TRANSPORT_TCP_ONLY_KEEP_CONNECTIONS_OPEN);
 	else if (strncmp(transport, TRANSPORT_TLS_KEEPOPEN, 3) == 0) 
 		getdns_context_set_dns_transport(this_context, GETDNS_TRANSPORT_TLS_ONLY_KEEP_CONNECTIONS_OPEN);
 	else if (strncmp(transport, TRANSPORT_TLS_TCP_KEEPOPEN, 12) == 0) 
 		getdns_context_set_dns_transport(this_context, GETDNS_TRANSPORT_TLS_FIRST_AND_FALL_BACK_TO_TCP_KEEP_CONNECTIONS_OPEN);
-	else if (strncmp(transport, TRANSPORT_UDP, 3) != 0) {
+	else if (strncmp(transport, TRANSPORT_STARTTLS_TCP_KEEPOPEN, 8) == 0) 
-		fprintf(stderr, "Invalid transport %s, must be one of udp, tcp or pipeline\n", transport);
+		getdns_context_set_dns_transport(this_context, GETDNS_TRANSPORT_STARTTLS_FIRST_AND_FALL_BACK_TO_TCP_KEEP_CONNECTIONS_OPEN);
+	else if (strncmp(transport, TRANSPORT_UDP_TCP, 3) != 0) {
+		fprintf(stderr, "Invalid transport %s, must be one of udp, udp_tcp, tcp or pipeline\n", transport);
 		exit(EXIT_FAILURE);
 	}
 
@@ -129,6 +138,30 @@ main(int argc, char** argv)
 	else {
 		getdns_context_run(this_context);
 	}
+
+	getdns_transport_t get_transport = GETDNS_TRANSPORT_UDP_ONLY;
+	return_value = getdns_context_get_dns_transport(this_context, &get_transport);
+	if (return_value != GETDNS_RETURN_GOOD) {
+		fprintf(stderr, "Trying to get transport type failed: %d\n",
+			return_value);
+		return (GETDNS_RETURN_GENERIC_ERROR);
+	}
+	fprintf(stderr, "Transport type is %d\n", get_transport);
+
+	size_t transport_count = 0;
+	getdns_transport_list_t *get_transport_list;
+	getdns_transport_list_t tmp[1] = {GETDNS_TRANSPORT_UDP};
+	get_transport_list = tmp;
+	return_value = getdns_context_get_dns_transport_list(this_context, &transport_count, &get_transport_list);
+	if (return_value != GETDNS_RETURN_GOOD) {
+		fprintf(stderr, "Trying to get transport type failed: %d\n",
+			return_value);
+		return (GETDNS_RETURN_GENERIC_ERROR);
+	}
+	for (size_t i = 0; i < transport_count; i++) {
+		fprintf(stderr, "Transport %d is %d\n", (int)i, get_transport_list[i]);
+	}
+	
 	/* Clean up */
 	getdns_context_destroy(this_context);
 	/* Assuming we get here, leave gracefully */