Add GnuTLS support for W32 and certificate and hostname verification in GnuTLS.

* src/gnutls.c: Renamed global_initialized to
gnutls_global_initialized.  Added internals for the
:verify-hostname-error, :verify-error, and :verify-flags
parameters of `gnutls-boot' and documented those parameters in the
docstring.  Start callback support.
(emacs_gnutls_handshake): Add Woe32 support. Retry handshake
unless a fatal error occured. Call gnutls_alert_send_appropriate
on error. Return error code.
(emacs_gnutls_write): Call emacs_gnutls_handle_error.
(emacs_gnutls_read): Likewise.
(Fgnutls_boot): Return handshake error code.
(emacs_gnutls_handle_error): New function.
(wsaerror_to_errno): Likewise.

* src/gnutls.h: Add GNUTLS_STAGE_CALLBACKS enum to denote we're in the
callbacks stage.

* src/w32.c (emacs_gnutls_pull): New function for GnuTLS on Woe32.
(emacs_gnutls_push): Likewise.

* src/w32.h (emacs_gnutls_pull): Add prototype.
(emacs_gnutls_push): Likewise.

1 files changed, 68 insertions, 1 deletions

diff --git a/src/w32.c b/src/w32.c
index 85e4a2025b9..065d730333b 100644
--- a/src/w32.c
+++ b/src/w32.c
@@ -6124,5 +6124,72 @@ serial_configure (struct Lisp_Process *p, Lisp_Object contact)
   p->childp = childp2;
 }
 
-/* end of w32.c */
+#ifdef HAVE_GNUTLS
+
+ssize_t
+emacs_gnutls_pull (gnutls_transport_ptr_t p, void* buf, size_t sz)
+{
+  int n, sc, err;
+  SELECT_TYPE fdset;
+  EMACS_TIME timeout;
+  struct Lisp_Process *process = (struct Lisp_Process *)p;
+  int fd = process->infd;
+
+  for (;;)
+    {
+      n = sys_read(fd, (char*)buf, sz);
+
+      if (n >= 0)
+        return n;
+
+      err = errno;
+
+      if (err == EWOULDBLOCK)
+        {
+          /* Set a small timeout.  */
+          EMACS_SET_SECS_USECS(timeout, 1, 0);
+          FD_ZERO (&fdset);
+          FD_SET ((int)fd, &fdset);
+
+          /* Use select with the timeout to poll the selector.  */
+          sc = select (fd + 1, &fdset, (SELECT_TYPE *)0, (SELECT_TYPE *)0,
+                       &timeout);
+
+          if (sc > 0)
+            continue;  /* Try again.  */
+
+          /* Translate the WSAEWOULDBLOCK alias EWOULDBLOCK to EAGAIN.
+             Also accept select return 0 as an indicator to EAGAIN.  */
+          if (sc == 0 || errno == EWOULDBLOCK)
+            err = EAGAIN;
+          else
+            err = errno; /* Other errors are just passed on.  */
+        }
+
+      gnutls_transport_set_errno (process->gnutls_state, err);
+
+      return -1;
+    }
+}
 
+ssize_t
+emacs_gnutls_push (gnutls_transport_ptr_t p, const void* buf, size_t sz)
+{
+  struct Lisp_Process *process = (struct Lisp_Process *)p;
+  int fd = proc->outfd;
+  ssize_t n = sys_write(fd, buf, sz);
+
+  /* 0 or more bytes written means everything went fine.  */
+  if (n >= 0)
+    return n;
+
+  /* Negative bytes written means we got an error in errno.
+     Translate the WSAEWOULDBLOCK alias EWOULDBLOCK to EAGAIN.  */
+  gnutls_transport_set_errno (process->gnutls_state,
+                              errno == EWOULDBLOCK ? EAGAIN : errno);
+
+  return -1;
+}
+#endif /* HAVE_GNUTLS */
+
+/* end of w32.c */