EMACS_INT
emacs_gnutls_read (struct Lisp_Process *proc, char *buf, EMACS_INT nbyte)
{
ssize_t rtnval;
gnutls_session_t state = proc->gnutls_state;
if (proc->gnutls_initstage != GNUTLS_STAGE_READY)
{
emacs_gnutls_handshake (proc);
return -1;
}
rtnval = fn_gnutls_record_recv (state, buf, nbyte);
if (rtnval >= 0)
return rtnval;
else if (rtnval == GNUTLS_E_UNEXPECTED_PACKET_LENGTH)
/* The peer closed the connection. */
return 0;
else if (emacs_gnutls_handle_error (state, rtnval) == 0)
/* non-fatal error */
return -1;
else {
/* a fatal error occurred */
return 0;
}
}
EMACS_INT
emacs_gnutls_write (struct Lisp_Process *proc, const char *buf, EMACS_INT nbyte)
{
ssize_t rtnval = 0;
EMACS_INT bytes_written;
gnutls_session_t state = proc->gnutls_state;
if (proc->gnutls_initstage != GNUTLS_STAGE_READY)
{
#ifdef EWOULDBLOCK
errno = EWOULDBLOCK;
#endif
#ifdef EAGAIN
errno = EAGAIN;
#endif
return 0;
}
bytes_written = 0;
while (nbyte > 0)
{
rtnval = fn_gnutls_record_send (state, buf, nbyte);
if (rtnval < 0)
{
if (rtnval == GNUTLS_E_INTERRUPTED)
continue;
else
{
/* If we get GNUTLS_E_AGAIN, then set errno
appropriately so that send_process retries the
correct way instead of erroring out. */
if (rtnval == GNUTLS_E_AGAIN)
{
#ifdef EWOULDBLOCK
errno = EWOULDBLOCK;
#endif
#ifdef EAGAIN
errno = EAGAIN;
#endif
}
break;
}
}
buf += rtnval;
nbyte -= rtnval;
bytes_written += rtnval;
}
emacs_gnutls_handle_error (state, rtnval);
return (bytes_written);
}
EMACS_INT
emacs_gnutls_read (struct Lisp_Process *proc, char *buf, EMACS_INT nbyte)
{
ssize_t rtnval;
gnutls_session_t state = proc->gnutls_state;
int log_level = proc->gnutls_log_level;
if (proc->gnutls_initstage != GNUTLS_STAGE_READY)
{
/* If the handshake count is under the limit, try the handshake
again and increment the handshake count. This count is kept
per process (connection), not globally. */
if (proc->gnutls_handshakes_tried < GNUTLS_EMACS_HANDSHAKES_LIMIT)
{
proc->gnutls_handshakes_tried++;
emacs_gnutls_handshake (proc);
GNUTLS_LOG2i (5, log_level, "Retried handshake",
proc->gnutls_handshakes_tried);
return -1;
}
GNUTLS_LOG (2, log_level, "Giving up on handshake; resetting retries");
proc->gnutls_handshakes_tried = 0;
return 0;
}
rtnval = fn_gnutls_record_recv (state, buf, nbyte);
if (rtnval >= 0)
return rtnval;
else if (rtnval == GNUTLS_E_UNEXPECTED_PACKET_LENGTH)
/* The peer closed the connection. */
return 0;
else if (emacs_gnutls_handle_error (state, rtnval) == 0)
/* non-fatal error */
return -1;
else {
/* a fatal error occurred */
return 0;
}
}
EMACS_INT
emacs_gnutls_write (struct Lisp_Process *proc, const char *buf, EMACS_INT nbyte)
{
ssize_t rtnval = 0;
EMACS_INT bytes_written;
gnutls_session_t state = proc->gnutls_state;
if (proc->gnutls_initstage != GNUTLS_STAGE_READY) {
#ifdef EWOULDBLOCK
errno = EWOULDBLOCK;
#endif
#ifdef EAGAIN
errno = EAGAIN;
#endif
return 0;
}
bytes_written = 0;
while (nbyte > 0)
{
rtnval = fn_gnutls_record_send (state, buf, nbyte);
if (rtnval < 0)
{
if (rtnval == GNUTLS_E_AGAIN || rtnval == GNUTLS_E_INTERRUPTED)
continue;
else
break;
}
buf += rtnval;
nbyte -= rtnval;
bytes_written += rtnval;
}
emacs_gnutls_handle_error (state, rtnval);
return (bytes_written);
}
static int
emacs_gnutls_handshake (struct Lisp_Process *proc)
{
gnutls_session_t state = proc->gnutls_state;
int ret;
if (proc->gnutls_initstage < GNUTLS_STAGE_HANDSHAKE_CANDO)
return -1;
if (proc->gnutls_initstage < GNUTLS_STAGE_TRANSPORT_POINTERS_SET)
{
#ifdef WINDOWSNT
/* On W32 we cannot transfer socket handles between different runtime
libraries, so we tell GnuTLS to use our special push/pull
functions. */
fn_gnutls_transport_set_ptr2 (state,
(gnutls_transport_ptr_t) proc,
(gnutls_transport_ptr_t) proc);
fn_gnutls_transport_set_push_function (state, &emacs_gnutls_push);
fn_gnutls_transport_set_pull_function (state, &emacs_gnutls_pull);
/* For non blocking sockets or other custom made pull/push
functions the gnutls_transport_set_lowat must be called, with
a zero low water mark value. (GnuTLS 2.10.4 documentation)
(Note: this is probably not strictly necessary as the lowat
value is only used when no custom pull/push functions are
set.) */
/* According to GnuTLS NEWS file, lowat level has been set to
zero by default in version 2.11.1, and the function
gnutls_transport_set_lowat was removed from the library in
version 2.99.0. */
if (!fn_gnutls_check_version ("2.11.1"))
fn_gnutls_transport_set_lowat (state, 0);
#else
/* This is how GnuTLS takes sockets: as file descriptors passed
in. For an Emacs process socket, infd and outfd are the
same but we use this two-argument version for clarity. */
fn_gnutls_transport_set_ptr2 (state,
(gnutls_transport_ptr_t) (long) proc->infd,
(gnutls_transport_ptr_t) (long) proc->outfd);
#endif
proc->gnutls_initstage = GNUTLS_STAGE_TRANSPORT_POINTERS_SET;
}
do
{
ret = fn_gnutls_handshake (state);
emacs_gnutls_handle_error (state, ret);
}
while (ret < 0 && fn_gnutls_error_is_fatal (ret) == 0);
proc->gnutls_initstage = GNUTLS_STAGE_HANDSHAKE_TRIED;
if (ret == GNUTLS_E_SUCCESS)
{
/* Here we're finally done. */
proc->gnutls_initstage = GNUTLS_STAGE_READY;
}
else
{
fn_gnutls_alert_send_appropriate (state, ret);
}
return ret;
}
