Merge pull request syslog-ng#3767 from alltilla/mqtt-http-proxy-fix

mqtt: only use http-proxy() if it is supported

Author: Gábor Nagy

configure.ac

@@ -1330,6 +1330,24 @@ if test "x$enable_mqtt" = "xyes" || test "x$enable_mqtt" = "xauto"; then
 	if test "x$enable_mqtt" = "xyes" && test "x$libpaho_mqtt" = "xno"; then
 		AC_MSG_ERROR(libPAHO_MQTT not found)
 	fi
+
+	if test "x$libpaho_mqtt" = "xyes"; then
+		CPPFLAGS_SAVE="$CPPFLAGS"
+		LDFLAGS_SAVE="$LDFLAGS"
+		CPPFLAGS="$CPPFLAGS $LIBPAHO_MQTT_CFLAGS"
+		LDFLAGS="$LDFLAGS $LIBPAHO_MQTT_LIBS"
+
+		AC_CHECK_MEMBER([MQTTClient_connectOptions.httpProxy],
+				[have_paho_http_proxy=1],
+				[have_paho_http_proxy=0],
+				[[#include "MQTTClient.h"]])
+
+		CPPFLAGS="$CPPFLAGS_SAVE"
+		LDFLAGS="$LDFLAGS_SAVE"
+
+		AC_DEFINE_UNQUOTED(HAVE_PAHO_HTTP_PROXY, $have_paho_http_proxy, [libpaho-mqtt supports MQTTClient_connectOptions::httpProxy])
+	fi
+
 	enable_mqtt=$libpaho_mqtt
 fi
 

modules/mqtt/CMakeLists.txt

@@ -5,6 +5,7 @@ if (NOT ENABLE_MQTT)
   return()
 endif()
 
+CHECK_STRUCT_HAS_MEMBER("MQTTClient_connectOptions" "httpProxy" "MQTTClient.h" SYSLOG_NG_HAVE_PAHO_HTTP_PROXY)
 
 add_subdirectory(destination)
 

modules/mqtt/destination/mqtt-destination.c

@@ -298,6 +298,17 @@ _init(LogPipe *d)
       return FALSE;
     }
 
+#if !SYSLOG_NG_HAVE_PAHO_HTTP_PROXY
+  if (self->http_proxy)
+    {
+      msg_warning_once("WARNING: the http-proxy() option of the mqtt() destination "
+                       "is not supported on the current libpaho-mqtt version. "
+                       "If you would like to use this feature, update to at least libpaho-mqtt 1.3.7");
+      g_free(self->http_proxy);
+      self->http_proxy = NULL;
+    }
+#endif
+
   if (!log_threaded_dest_driver_init_method(d))
     {
       return FALSE;

modules/mqtt/destination/mqtt-worker.c

@@ -227,11 +227,13 @@ _connect(LogThreadedDestWorker *s)
   conn_opts.username = owner->username;
   conn_opts.password = owner->password;
 
+#if SYSLOG_NG_HAVE_PAHO_HTTP_PROXY
   if (owner->http_proxy)
     {
       conn_opts.httpProxy = owner->http_proxy;
       conn_opts.httpsProxy = owner->http_proxy;
     }
+#endif
 
   MQTTClient_SSLOptions ssl_opts = _create_ssl_options(self);
   conn_opts.ssl = &ssl_opts;

syslog-ng-config.h.in

@@ -92,3 +92,4 @@
 #cmakedefine01 SYSLOG_NG_ENABLE_PYTHONv2
 #cmakedefine01 SYSLOG_NG_ENABLE_PYTHONv3
 #cmakedefine SYSLOG_NG_HAVE_RD_KAFKA_INIT_TRANSACTIONS
+#cmakedefine01 SYSLOG_NG_HAVE_PAHO_HTTP_PROXY