From 85c3fe47292f4e4e47a1f58f1347cb1f6d03b37e Mon Sep 17 00:00:00 2001
From: Manuel Bentele
Date: Tue, 20 Oct 2020 15:31:52 +0200
Subject: [BUILD] add option to build the dnbd3-server with afl-fuzz support

The afl-fuzz support for the dnbd3-server requires an AFL C compiler
like afl-gcc and can be enabled with the CMake option DNBD3_SERVER_AFL.
---
 src/server/CMakeLists.txt | 18 ++++++++++++++++++
 src/server/server.c       | 17 ++++++++++++-----
 2 files changed, 30 insertions(+), 5 deletions(-)

(limited to 'src/server')

diff --git a/src/server/CMakeLists.txt b/src/server/CMakeLists.txt
index 1855d91..aa981f6 100644
--- a/src/server/CMakeLists.txt
+++ b/src/server/CMakeLists.txt
@@ -13,9 +13,27 @@ endif(NOT JANSSON_FOUND)
 add_definitions(-D_GNU_SOURCE)
 
 if(DNBD3_SERVER_AFL)
+    # check if DNBD3_RELEASE_HARDEN is disabled
+    if(DNBD3_RELEASE_HARDEN)
+        message(FATAL_ERROR "DNBD3_SERVER_AFL can only be enabled if DNBD3_RELEASE_HARDEN is disabled")
+    endif(DNBD3_RELEASE_HARDEN)
+
     # build dnbd3-server with AFL support
     message(STATUS "Building dnbd3-server with AFL support")
     add_definitions(-DDNBD3_SERVER_AFL)
+
+    # change compiler for dnbd3-server sources if AFL enabled
+    include(CheckAFLCCompiler)
+    check_afl_c_compiler(AFL_C_COMPILER AFL_C_COMPILER_NAME ${CMAKE_C_COMPILER} ${CMAKE_C_COMPILER_ID})
+    if(AFL_C_COMPILER)
+        message(STATUS "Check for working AFL C compiler: ${AFL_C_COMPILER} - done")
+        # change C compiler to a corresponding AFL C compiler
+        set(CMAKE_C_COMPILER "${AFL_C_COMPILER}")
+    else(AFL_C_COMPILER)
+        # no corresponding AFL C compiler found
+        message(STATUS "Check for working AFL C compiler: ${AFL_C_COMPILER_NAME} - failed")
+        message(FATAL_ERROR "No corresponding AFL C compiler ${AFL_C_COMPILER_NAME} was found for the C compiler ${CMAKE_C_COMPILER}!")
+    endif(AFL_C_COMPILER)
 endif(DNBD3_SERVER_AFL)
 
 add_executable(dnbd3-server ${CMAKE_CURRENT_SOURCE_DIR}/altservers.c
diff --git a/src/server/server.c b/src/server/server.c
index 55ec042..0ee51c4 100644
--- a/src/server/server.c
+++ b/src/server/server.c
@@ -217,6 +217,16 @@ int main(int argc, char *argv[])
 			{ 0, 0, 0, 0 }
 	};
 
+	log_init();
+
+	/* set proper output stream for AFL */
+#ifdef DNBD3_SERVER_AFL
+	if ( log_setConsoleOutputStream(stderr) < 0 ) {
+		logadd( LOG_ERROR, "Failed to set output stream for AFL to stderr" );
+		exit( EXIT_FAILURE );
+	}
+#endif
+
 	mainPid = getpid();
 	mainThread = pthread_self();
 	opt = getopt_long( argc, argv, optString, longOpts, &longIndex );
@@ -278,6 +288,7 @@ int main(int argc, char *argv[])
 		opt = getopt_long( argc, argv, optString, longOpts, &longIndex );
 	}
 
+
 	// Load general config
 
 	if ( _configDir == NULL ) _configDir = strdup( "/etc/dnbd3-server" );
@@ -291,8 +302,6 @@ int main(int argc, char *argv[])
 	timing_get( &startupTime );
 
 #ifdef DNBD3_SERVER_AFL
-	// ###### AFL
-	//
 	image_serverStartup();
 	net_init();
 	uplink_globalsInit();
@@ -316,9 +325,7 @@ int main(int argc, char *argv[])
 		net_handleNewConnection( dnbd3_client );
 		exit( 0 );
 	}
-	//
-	// ###### AFL END
-#endif
+#endif  /* DNBD3_SERVER_AFL */
 
 
 	// One-shots first:
-- 
cgit v1.2.3-55-g7522