+
+static int
+wgnutls_read_timeout (int fd, char *buf, int bufsize, void *arg, double timeout)
+{
+#ifdef F_GETFL
+ int flags = 0;
+#endif
+ int ret = 0;
+ struct ptimer *timer = NULL;
+ struct wgnutls_transport_context *ctx = arg;
+ int timed_out = 0;
+
+ if (timeout)
+ {
+#ifdef F_GETFL
+ flags = fcntl (fd, F_GETFL, 0);
+ if (flags < 0)
+ return flags;
+ if (fcntl (fd, F_SETFL, flags | O_NONBLOCK))
+ return -1;
+#else
+ /* XXX: Assume it was blocking before. */
+ const int one = 1;
+ if (ioctl (fd, FIONBIO, &one) < 0)
+ return -1;
+#endif
+
+ timer = ptimer_new ();
+ if (timer == NULL)
+ return -1;
+ }
+
+ do
+ {
+ double next_timeout = 0;
+ if (timeout)
+ {
+ next_timeout = timeout - ptimer_measure (timer);
+ if (next_timeout < 0)
+ break;
+ }
+
+ ret = GNUTLS_E_AGAIN;
+ if (timeout == 0 || gnutls_record_check_pending (ctx->session)
+ || select_fd (fd, next_timeout, WAIT_FOR_READ))
+ {
+ ret = gnutls_record_recv (ctx->session, buf, bufsize);
+ timed_out = timeout && ptimer_measure (timer) >= timeout;
+ }
+ }
+ while (ret == GNUTLS_E_INTERRUPTED || (ret == GNUTLS_E_AGAIN && !timed_out));
+
+ if (timeout)
+ {
+ ptimer_destroy (timer);
+
+#ifdef F_GETFL
+ if (fcntl (fd, F_SETFL, flags) < 0)
+ return -1;
+#else
+ const int zero = 0;
+ if (ioctl (fd, FIONBIO, &zero) < 0)
+ return -1;
+#endif
+
+ if (timed_out && ret == GNUTLS_E_AGAIN)
+ errno = ETIMEDOUT;
+ }
+
+ return ret;
+}
+