contrib: fixed c++ compatibility of unix port

contrib/ports/unix/port/include/arch/cc.h

@@ -52,6 +52,10 @@
 #define LWIP_TIMEVAL_PRIVATE 0
 #include <sys/time.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 #define LWIP_ERRNO_INCLUDE <errno.h>
 
 #if defined(LWIP_UNIX_LINUX) || defined(LWIP_UNIX_HURD) || defined(LWIP_UNIX_KFREEBSD)
@@ -86,4 +90,8 @@ typedef struct sio_status_s sio_status_t;
 
 typedef unsigned int sys_prot_t;
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* LWIP_ARCH_CC_H */

contrib/ports/unix/port/include/arch/perf.h

@@ -34,6 +34,10 @@
 
 #include <sys/times.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 #ifdef PERF
 #define PERF_START  { \
                          unsigned long __c1l, __c1h, __c2l, __c2h; \
@@ -60,4 +64,8 @@ void perf_print_times(struct tms *start, struct tms *end, char *key);
 
 void perf_init(char *fname);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* LWIP_ARCH_PERF_H */

contrib/ports/unix/port/include/arch/sys_arch.h

@@ -32,6 +32,10 @@
 #ifndef LWIP_ARCH_SYS_ARCH_H
 #define LWIP_ARCH_SYS_ARCH_H
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 #define SYS_MBOX_NULL NULL
 #define SYS_SEM_NULL  NULL
 
@@ -87,4 +91,8 @@ void sys_unlock_tcpip_core(void);
 #define UNLOCK_TCPIP_CORE()        sys_unlock_tcpip_core()
 #endif
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* LWIP_ARCH_SYS_ARCH_H */