Merge branch 'maciejsszmigiero-tcp-send-timeout' into develop

CMakeLists.txt

@@ -559,6 +559,8 @@ else ()
   endif ()
 endif ()
 
+check_symbol_exists(TCP_USER_TIMEOUT "sys/socket.h;netinet/tcp.h" HAVE_DECL_TCP_USER_TIMEOUT)
+
 # Main library
 add_library(getdns_objects OBJECT
   src/anchor.c

ChangeLog

@@ -6,6 +6,10 @@
   * Issue #466: Memory leak with retrying queries (for examples
     with search paths). Thanks doublez13.
   * Issue #480: Cross compiling is broken with CMake
+  * Setting of the number of milliseconds send data may remain
+    unacknowledged by the peer in a TCP connection (when supported 
+    by the OS) with getdns_context_set_tcp_send_timeout()
+    Thanks maciejsszmigiero.
 
 * 2020-02-28: Version 1.6.0
   * Issues #457, #458, #461: New symbols with libnettle >= 3.4.

cmake/include/cmakeconfig.h.in

@@ -211,6 +211,8 @@
 
 #cmakedefine USE_OSX_TCP_FASTOPEN	1
 
+#cmakedefine HAVE_DECL_TCP_USER_TIMEOUT	1
+
 #cmakedefine HAVE_NEW_UV_TIMER_CB	1
 
 #cmakedefine HAVE_TARGET_ENDIANNESS

src/context.c

@@ -1435,6 +1435,7 @@ getdns_context_create_with_extended_memory_functions(
 
 	result->timeout = 5000;
 	result->idle_timeout = 0;
+	result->tcp_send_timeout = -1;
 	result->follow_redirects = GETDNS_REDIRECTS_FOLLOW;
 	result->dns_root_servers = NULL;
 #if defined(HAVE_LIBUNBOUND) && !defined(HAVE_UB_CTX_SET_STUB)
@@ -2367,6 +2368,34 @@ getdns_context_set_idle_timeout(getdns_context *context, uint64_t timeout)
 	return GETDNS_RETURN_GOOD;
 }               /* getdns_context_set_timeout */
 
+/*
+ * getdns_context_unset_tcp_send_timeout
+ *
+ */
+getdns_return_t
+getdns_context_unset_tcp_send_timeout(getdns_context *context)
+{
+	if (!context)
+		return GETDNS_RETURN_INVALID_PARAMETER;
+
+	context->tcp_send_timeout = -1;
+	return GETDNS_RETURN_GOOD;
+}
+
+/*
+ * getdns_context_set_tcp_send_timeout
+ *
+ */
+getdns_return_t
+getdns_context_set_tcp_send_timeout(struct getdns_context *context,
+    uint32_t value)
+{
+	if (!context || value > INT_MAX)
+		return GETDNS_RETURN_INVALID_PARAMETER;
+
+	context->tcp_send_timeout = value;
+	return GETDNS_RETURN_GOOD;
+}
 
 /*
  * getdns_context_set_follow_redirects
@@ -3837,6 +3866,9 @@ _get_context_settings(const getdns_context* context)
 	                           (context->timeout > 0xFFFFFFFFull) ? 0xFFFFFFFF: (uint32_t) context->timeout)
 	    || getdns_dict_set_int(result, "idle_timeout",
 	                           (context->idle_timeout > 0xFFFFFFFFull) ? 0xFFFFFFFF : (uint32_t) context->idle_timeout)
+	    || (  context->tcp_send_timeout != -1
+	       && getdns_dict_set_int(result, "tcp_send_timeout",
+	                              context->tcp_send_timeout))
 	    || getdns_dict_set_int(result, "limit_outstanding_queries",
 	                           context->limit_outstanding_queries)
             || getdns_dict_set_int(result, "dnssec_allowed_skew",
@@ -4308,6 +4340,16 @@ CONTEXT_GETTER(timeout                    , uint64_t)
 CONTEXT_GETTER(idle_timeout               , uint64_t)
 CONTEXT_GETTER(follow_redirects           , getdns_redirects_t)
 
+getdns_return_t
+getdns_context_get_tcp_send_timeout(
+    const getdns_context *context, uint32_t* value)
+{
+	if (!context || !value) return GETDNS_RETURN_INVALID_PARAMETER;
+	*value = context->tcp_send_timeout == -1 ? 0
+	       : context->tcp_send_timeout;
+	return GETDNS_RETURN_GOOD;
+}
+
 getdns_return_t
 getdns_context_get_dns_root_servers(
     const getdns_context *context, getdns_list **value)
@@ -4647,6 +4689,7 @@ _getdns_context_config_setting(getdns_context *context,
 	CONTEXT_SETTING_INT(dns_transport)
 	CONTEXT_SETTING_ARRAY(dns_transport_list, transport_list)
 	CONTEXT_SETTING_INT(idle_timeout)
+	CONTEXT_SETTING_INT(tcp_send_timeout)
 	CONTEXT_SETTING_INT(limit_outstanding_queries)
 	CONTEXT_SETTING_INT(timeout)
 	CONTEXT_SETTING_INT(follow_redirects)

src/context.h

@@ -325,6 +325,7 @@ struct getdns_context {
 	size_t               namespace_count;
 	uint64_t             timeout;
 	uint64_t             idle_timeout;
+	int                  tcp_send_timeout; /* -1 is unset */
 	getdns_redirects_t   follow_redirects;
 	getdns_list          *dns_root_servers;
 

src/getdns/getdns.h.in

@@ -1514,6 +1514,24 @@ getdns_context_set_dns_transport_list(getdns_context *context,
 getdns_return_t
 getdns_context_set_idle_timeout(getdns_context *context, uint64_t timeout);
 
+/**
+ * Set the number of milliseconds send data may remain unacknowledged by
+ * the peer in a TCP connection, if supported by the operation system.
+ * When not set (the default), the system default is left alone.
+ *
+ * @see getdns_context_get_tcp_send_timeout
+ * @see getdns_context_unset_tcp_send_timeout
+ * @param context The context to configure
+ * @param value The number of milliseconds the send data may remain
+ *              unacknowledged by the peer in a TCP connection.
+ * @return GETDNS_RETURN_GOOD when successful.
+ * @return GETDNS_RETURN_INVALID_PARAMETER when context was NULL or the
+ *         value was too high.
+ */
+getdns_return_t
+getdns_context_set_tcp_send_timeout(getdns_context *context,
+    uint32_t value);
+
 /**
  * Limit the number of outstanding DNS queries. When more than limit requests
  * are scheduled, they are kept on an internal queue, to be rescheduled when

src/getdns/getdns_extra.h.in

@@ -540,6 +540,18 @@ getdns_context_set_tls_query_padding_blocksize(getdns_context *context, uint16_t
 getdns_return_t
 getdns_context_unset_edns_maximum_udp_payload_size(getdns_context *context);
 
+/**
+ * Configure context to use the system default setting for the time
+ * send data may remain unacknowledged by the peer in a TCP connection.
+ * @see getdns_context_set_tcp_send_timeout
+ * @see getdns_context_get_tcp_send_timeout
+ * @param context The context to configure
+ * @return GETDNS_RETURN_GOOD on success
+ * @return GETDNS_RETURN_INVALID_PARAMETER if context is null.
+ */
+getdns_return_t
+getdns_context_unset_tcp_send_timeout(getdns_context *context);
+
 
 typedef enum getdns_loglevel_type {
 	GETDNS_LOG_EMERG   = 0,
@@ -992,6 +1004,22 @@ getdns_return_t
 getdns_context_get_idle_timeout(
     const getdns_context *context, uint64_t *timeout);
 
+/**
+ * Get the number of milliseconds send data may remain unacknowledged by
+ * the peer in a TCP connection setting from context.
+ * @see getdns_context_set_tcp_send_timeout
+ * @see getdns_context_unset_tcp_send_timeout
+ * @param[in]  context The context from which to get the setting
+ * @param[out] value   The number of milliseconds the send data may remain
+ *                     unacknowledged by the peer in a TCP connection.
+ *                     When the value is unset, 0 is returned.
+ * @return GETDNS_RETURN_GOOD when successful
+ * @return GETDNS_RETURN_INVALID_PARAMETER when context or value was NULL.
+ */
+getdns_return_t
+getdns_context_get_tcp_send_timeout(const getdns_context *context,
+    uint32_t *value);
+
 /**
  * Get the setting that says whether or not DNS queries follow redirects.
  * @see getdns_context_set_follow_redirects

src/libgetdns.symbols

@@ -30,6 +30,7 @@ getdns_context_get_resolution_type
 getdns_context_get_resolvconf
 getdns_context_get_round_robin_upstreams
 getdns_context_get_suffix
+getdns_context_get_tcp_send_timeout
 getdns_context_get_timeout
 getdns_context_get_tls_authentication
 getdns_context_get_tls_backoff_time
@@ -78,6 +79,7 @@ getdns_context_set_resolvconf
 getdns_context_set_return_dnssec_status
 getdns_context_set_round_robin_upstreams
 getdns_context_set_suffix
+getdns_context_set_tcp_send_timeout
 getdns_context_set_timeout
 getdns_context_set_tls_authentication
 getdns_context_set_tls_backoff_time
@@ -98,6 +100,7 @@ getdns_context_set_update_callback
 getdns_context_set_upstream_recursive_servers
 getdns_context_set_use_threads
 getdns_context_unset_edns_maximum_udp_payload_size
+getdns_context_unset_tcp_send_timeout
 getdns_convert_alabel_to_ulabel
 getdns_convert_dns_name_to_fqdn
 getdns_convert_fqdn_to_dns_name

src/stub.c

@@ -448,8 +448,27 @@ getdns_sock_nonblock(int sockfd)
 #endif
 }
 
+/** best effort to set TCP send timeout */
+static void
+getdns_sock_tcp_send_timeout(getdns_upstream *upstream, int sockfd,
+                             int send_timeout)
+{
+#if defined(HAVE_DECL_TCP_USER_TIMEOUT)
+	unsigned int val = send_timeout;
+	if (setsockopt(sockfd, IPPROTO_TCP, TCP_USER_TIMEOUT,
+	    &val, sizeof(val)) != 0) {
+		_getdns_upstream_log(upstream,
+		    GETDNS_LOG_UPSTREAM_STATS, GETDNS_LOG_WARNING,
+		    "%-40s : Upstream   : "
+		    "Could not enable TCP send timeout\n",
+		     upstream->addr_str);
+	}
+#endif
+}
+
 static int
-tcp_connect(getdns_upstream *upstream, getdns_transport_list_t transport) 
+tcp_connect(getdns_upstream *upstream, getdns_transport_list_t transport,
+            int send_timeout)
 {
 #if defined(TCP_FASTOPEN) || defined(TCP_FASTOPEN_CONNECT)
 # ifdef USE_WINSOCK
@@ -468,6 +487,8 @@ tcp_connect(getdns_upstream *upstream, getdns_transport_list_t transport)
 		return -1;
 
 	getdns_sock_nonblock(fd);
+	if (send_timeout != -1)
+		getdns_sock_tcp_send_timeout(upstream, fd, send_timeout);
 #ifdef USE_OSX_TCP_FASTOPEN
 	sa_endpoints_t endpoints;
 	endpoints.sae_srcif = 0;
@@ -2148,7 +2169,8 @@ upstream_connect(getdns_upstream *upstream, getdns_transport_list_t transport,
 		/* Use existing if available*/
 		if (upstream->fd != -1)
 			return upstream->fd;
-		fd = tcp_connect(upstream, transport);
+		fd = tcp_connect(upstream, transport,
+				 dnsreq->context->tcp_send_timeout);
 		if (fd == -1) {
 			upstream_failed(upstream, 1);
 			return -1;