+  struct hostent *he = NULL;
+  *err = 0;
+#if defined(HAVE_FUNC_GETHOSTBYNAME_R_6)
+  if (gethostbyname_r(hostname, h, (char*)buffer, size, &he, err))
+    he = NULL;
+#elif defined(HAVE_FUNC_GETHOSTBYNAME_R_5)
+  he = gethostbyname_r(hostname, h, (char*)buffer, size, err);
+#elif defined(HAVE_FUNC_GETHOSTBYNAME_R_3)
+  if (gethostbyname_r(hostname, h, (struct hostent_data*) buffer))
+  {
+    he = NULL;
+    *err = h_errno;
+  }
+  else
+    he = h;
+#elif defined(HAVE_GETHOSTBYNAME)
+#if wxUSE_THREADS
+  static wxMutex nameLock;
+  wxMutexLocker locker(nameLock);
+#endif
+  he = gethostbyname(hostname);
+  if (!he)
+    *err = h_errno;
+  else
+    he = deepCopyHostent(h, he, (char*)buffer, size, err);
+#endif
+  return he;
+}
+
+struct hostent * wxGethostbyaddr_r(const char *addr_buf, int buf_size,
+                                  int proto, struct hostent *h,
+                                  void *buffer, int size, int *err)
+{
+  struct hostent *he = NULL;
+  *err = 0;
+#if defined(HAVE_FUNC_GETHOSTBYNAME_R_6)
+  if (gethostbyaddr_r(addr_buf, buf_size, proto, h,
+                     (char*)buffer, size, &he, err))
+    he = NULL;
+#elif defined(HAVE_FUNC_GETHOSTBYNAME_R_5)
+  he = gethostbyaddr_r(addr_buf, buf_size, proto, h, (char*)buffer, size, err);
+#elif defined(HAVE_FUNC_GETHOSTBYNAME_R_3)
+  if (gethostbyaddr_r(addr_buf, buf_size, proto, h,
+                       (struct hostent_data*) buffer))
+  {
+    he = NULL;
+    *err = h_errno;
+  }
+  else
+    he = h;
+#elif defined(HAVE_GETHOSTBYNAME)
+#if wxUSE_THREADS
+  static wxMutex addrLock;
+  wxMutexLocker locker(addrLock);
+#endif
+  he = gethostbyaddr(addr_buf, buf_size, proto);
+  if (!he)
+    *err = h_errno;
+  else
+    he = deepCopyHostent(h, he, (char*)buffer, size, err);
+#endif
+  return he;
+}
+
+#if defined(HAVE_GETSERVBYNAME)
+static struct servent * deepCopyServent(struct servent *s,
+                                       const struct servent *se,
+                                       char *buffer, int size)
+{
+  memcpy(s, se, sizeof(struct servent));
+  int len = strlen(s->s_name);
+  if (len > size)
+    len = size - 1;
+  memcpy(buffer, s->s_name, len);
+  buffer[len] = '\0';
+  s->s_name = buffer;
+  buffer += len + 1;
+  size -= len + 1;
+  len = strlen(s->s_proto);
+  if (len > size)
+    len = size - 1;
+  memcpy(buffer, s->s_proto, len);
+  buffer[len] = '\0';
+  s->s_proto = buffer;
+  buffer += len + 1;
+  size -= len + 1;
+  for (char **q = s->s_aliases; size > 0 && *q != 0; q++){
+    len = strlen(*q);
+    if (len > size)
+      len = size - 1;
+    memcpy(buffer, *q, len);
+    buffer[len] = '\0';
+    *q = buffer;
+    buffer += len + 1;
+    size -= len + 1;
+  }
+  return s;