backport openbsd support

I2PEndian.h

@@ -3,7 +3,7 @@
 #include <inttypes.h>
 #include <string.h>
 
-#if defined(__linux__) || defined(__FreeBSD_kernel__)
+#if defined(__linux__) || defined(__FreeBSD_kernel__) || defined(__OpenBSD__)
 #include <endian.h>
 #elif __FreeBSD__
 #include <sys/endian.h>

build/CMakeLists.txt

@@ -130,6 +130,8 @@ elseif (CMAKE_SYSTEM_NAME STREQUAL "FreeBSD")
   add_definitions( "-D_GLIBCXX_USE_NANOSLEEP=1" )
 elseif (CMAKE_SYSTEM_NAME STREQUAL "Darwin")
   list (APPEND DAEMON_SRC "${CMAKE_SOURCE_DIR}/DaemonLinux.cpp")
+elseif (CMAKE_SYSTEM_NAME STREQUAL "OpenBSD")
+  list (APPEND DAEMON_SRC "${CMAKE_SOURCE_DIR}/DaemonLinux.cpp")
 elseif (CMAKE_SYSTEM_NAME STREQUAL "Windows")
   list (APPEND DAEMON_SRC "${CMAKE_SOURCE_DIR}/DaemonWin32.cpp")
   list (APPEND DAEMON_SRC "${CMAKE_SOURCE_DIR}/Win32/Win32Service.cpp")

util.cpp

@@ -16,7 +16,7 @@
 #include "util.h"
 #include "Log.h"
 
-#if defined(__linux__) || defined(__FreeBSD_kernel__)
+#if defined(__linux__) || defined(__FreeBSD_kernel__) || defined(__APPLE__) || defined(__OpenBSD__)
 #include <sys/types.h>
 #include <ifaddrs.h>
 #elif defined(WIN32)
@@ -508,7 +508,7 @@ namespace net
 {
 	int GetMTU (const boost::asio::ip::address& localAddress)
 	{
-#if defined(__linux__) || defined(__FreeBSD_kernel__)	
+#if defined(__linux__) || defined(__FreeBSD_kernel__) || defined(__APPLE__) || defined(__OpenBSD__)	
 		ifaddrs * ifaddr, * ifa = nullptr;
 		if (getifaddrs(&ifaddr) == -1) 
 		{