Fix Mac OSX build error.

Makefile.osx

@@ -1,10 +1,15 @@
 CXX = clang++
-CXXFLAGS = -g -Wall -std=c++11 -DCRYPTOPP_DISABLE_ASM
+CXXFLAGS = -g -Wall -std=c++11 -DCRYPTOPP_DISABLE_ASM -DMAC_OSX
 #CXXFLAGS = -g -O2 -Wall -std=c++11 -DCRYPTOPP_DISABLE_ASM
 INCFLAGS = -I/usr/local/include
 LDFLAGS = -Wl,-rpath,/usr/local/lib -L/usr/local/lib
 LDLIBS = -lcryptopp -lboost_system -lboost_date_time -lboost_filesystem -lboost_regex -lboost_program_options -lpthread
 
+ifeq ($(USE_UPNP),1)
+  LDFLAGS += -ldl
+  CXXFLAGS += -DUSE_UPNP
+endif
+
 # OSX Notes
 # http://www.hutsby.net/2011/08/macs-with-aes-ni.html
 # Seems like all recent Mac's have AES-NI, after firmware upgrade 2.2

SOCKS.h

@@ -8,6 +8,19 @@
 #include "Streaming.h"
 #include "I2PTunnel.h"
 
+#ifdef MAC_OSX
+ /*
+ *  - MAXHOSTNAMELEN from <sys/param.h>
+ *    on MacOS X 10.3, FreeBSD 6.0, NetBSD 3.0, OpenBSD 3.8, AIX 5.1, HP-UX 11,
+ *    IRIX 6.5, OSF/1 5.1, Interix 3.5, Haiku,
+ *  - MAXHOSTNAMELEN from <netdb.h>
+ *    on Solaris 10, Cygwin, BeOS,
+ *  - 256 on mingw.
+ *
+ * */
+#define HOST_NAME_MAX 256
+#endif
+
 namespace i2p
 {
 namespace proxy