/* returns false on out-of-memory */
static dbus_bool_t
do_reading (DBusTransport *transport)
{
DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
DBusString *buffer;
int bytes_read;
int total;
dbus_bool_t oom;
int saved_errno;
_dbus_verbose ("fd = %" DBUS_SOCKET_FORMAT "\n",
_dbus_socket_printable (socket_transport->fd));
/* No messages without authentication! */
if (!_dbus_transport_try_to_authenticate (transport))
return TRUE;
oom = FALSE;
total = 0;
again:
/* See if we've exceeded max messages and need to disable reading */
check_read_watch (transport);
if (total > socket_transport->max_bytes_read_per_iteration)
{
_dbus_verbose ("%d bytes exceeds %d bytes read per iteration, returning\n",
total, socket_transport->max_bytes_read_per_iteration);
goto out;
}
_dbus_assert (socket_transport->read_watch != NULL ||
transport->disconnected);
if (transport->disconnected)
goto out;
if (!dbus_watch_get_enabled (socket_transport->read_watch))
return TRUE;
if (_dbus_auth_needs_decoding (transport->auth))
{
/* Does fd passing even make sense with encoded data? */
_dbus_assert(!DBUS_TRANSPORT_CAN_SEND_UNIX_FD(transport));
if (_dbus_string_get_length (&socket_transport->encoded_incoming) > 0)
bytes_read = _dbus_string_get_length (&socket_transport->encoded_incoming);
else
bytes_read = _dbus_read_socket (socket_transport->fd,
&socket_transport->encoded_incoming,
socket_transport->max_bytes_read_per_iteration);
saved_errno = _dbus_save_socket_errno ();
_dbus_assert (_dbus_string_get_length (&socket_transport->encoded_incoming) ==
bytes_read);
if (bytes_read > 0)
{
_dbus_message_loader_get_buffer (transport->loader,
&buffer);
if (!_dbus_auth_decode_data (transport->auth,
&socket_transport->encoded_incoming,
buffer))
{
_dbus_verbose ("Out of memory decoding incoming data\n");
_dbus_message_loader_return_buffer (transport->loader,
buffer);
oom = TRUE;
goto out;
}
_dbus_message_loader_return_buffer (transport->loader,
buffer);
_dbus_string_set_length (&socket_transport->encoded_incoming, 0);
_dbus_string_compact (&socket_transport->encoded_incoming, 2048);
}
}
else
{
_dbus_message_loader_get_buffer (transport->loader,
&buffer);
#ifdef HAVE_UNIX_FD_PASSING
if (DBUS_TRANSPORT_CAN_SEND_UNIX_FD(transport))
{
int *fds;
unsigned int n_fds;
if (!_dbus_message_loader_get_unix_fds(transport->loader, &fds, &n_fds))
{
_dbus_verbose ("Out of memory reading file descriptors\n");
_dbus_message_loader_return_buffer (transport->loader, buffer);
oom = TRUE;
goto out;
}
bytes_read = _dbus_read_socket_with_unix_fds(socket_transport->fd,
buffer,
socket_transport->max_bytes_read_per_iteration,
fds, &n_fds);
saved_errno = _dbus_save_socket_errno ();
if (bytes_read >= 0 && n_fds > 0)
_dbus_verbose("Read %i unix fds\n", n_fds);
_dbus_message_loader_return_unix_fds(transport->loader, fds, bytes_read < 0 ? 0 : n_fds);
}
else
#endif
{
bytes_read = _dbus_read_socket (socket_transport->fd,
buffer, socket_transport->max_bytes_read_per_iteration);
saved_errno = _dbus_save_socket_errno ();
}
_dbus_message_loader_return_buffer (transport->loader,
buffer);
}
if (bytes_read < 0)
{
/* EINTR already handled for us */
if (_dbus_get_is_errno_enomem (saved_errno))
{
_dbus_verbose ("Out of memory in read()/do_reading()\n");
oom = TRUE;
goto out;
}
else if (_dbus_get_is_errno_eagain_or_ewouldblock (saved_errno))
goto out;
else
{
_dbus_verbose ("Error reading from remote app: %s\n",
_dbus_strerror (saved_errno));
do_io_error (transport);
goto out;
}
}
else if (bytes_read == 0)
{
_dbus_verbose ("Disconnected from remote app\n");
do_io_error (transport);
goto out;
}
else
{
_dbus_verbose (" read %d bytes\n", bytes_read);
total += bytes_read;
if (!_dbus_transport_queue_messages (transport))
{
oom = TRUE;
_dbus_verbose (" out of memory when queueing messages we just read in the transport\n");
goto out;
}
/* Try reading more data until we get EAGAIN and return, or
* exceed max bytes per iteration. If in blocking mode of
* course we'll block instead of returning.
*/
goto again;
}
out:
if (oom)
return FALSE;
else
return TRUE;
}
/* returns false on oom */
static dbus_bool_t
do_writing (DBusTransport *transport)
{
int total;
DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
dbus_bool_t oom;
/* No messages without authentication! */
if (!_dbus_transport_try_to_authenticate (transport))
{
_dbus_verbose ("Not authenticated, not writing anything\n");
return TRUE;
}
if (transport->disconnected)
{
_dbus_verbose ("Not connected, not writing anything\n");
return TRUE;
}
#if 1
_dbus_verbose ("do_writing(), have_messages = %d, fd = %d\n",
_dbus_connection_has_messages_to_send_unlocked (transport->connection),
socket_transport->fd);
#endif
oom = FALSE;
total = 0;
while (!transport->disconnected &&
_dbus_connection_has_messages_to_send_unlocked (transport->connection))
{
int bytes_written;
DBusMessage *message;
const DBusString *header;
const DBusString *body;
int header_len, body_len;
int total_bytes_to_write;
if (total > socket_transport->max_bytes_written_per_iteration)
{
_dbus_verbose ("%d bytes exceeds %d bytes written per iteration, returning\n",
total, socket_transport->max_bytes_written_per_iteration);
goto out;
}
message = _dbus_connection_get_message_to_send (transport->connection);
_dbus_assert (message != NULL);
dbus_message_lock (message);
#if 0
_dbus_verbose ("writing message %p\n", message);
#endif
_dbus_message_get_network_data (message,
&header, &body);
header_len = _dbus_string_get_length (header);
body_len = _dbus_string_get_length (body);
if (_dbus_auth_needs_encoding (transport->auth))
{
/* Does fd passing even make sense with encoded data? */
_dbus_assert(!DBUS_TRANSPORT_CAN_SEND_UNIX_FD(transport));
if (_dbus_string_get_length (&socket_transport->encoded_outgoing) == 0)
{
if (!_dbus_auth_encode_data (transport->auth,
header, &socket_transport->encoded_outgoing))
{
oom = TRUE;
goto out;
}
if (!_dbus_auth_encode_data (transport->auth,
body, &socket_transport->encoded_outgoing))
{
_dbus_string_set_length (&socket_transport->encoded_outgoing, 0);
oom = TRUE;
goto out;
}
}
total_bytes_to_write = _dbus_string_get_length (&socket_transport->encoded_outgoing);
#if 0
_dbus_verbose ("encoded message is %d bytes\n",
total_bytes_to_write);
#endif
bytes_written =
_dbus_write_socket (socket_transport->fd,
&socket_transport->encoded_outgoing,
socket_transport->message_bytes_written,
total_bytes_to_write - socket_transport->message_bytes_written);
}
else
{
total_bytes_to_write = header_len + body_len;
#if 0
_dbus_verbose ("message is %d bytes\n",
total_bytes_to_write);
#endif
#ifdef HAVE_UNIX_FD_PASSING
if (socket_transport->message_bytes_written <= 0 && DBUS_TRANSPORT_CAN_SEND_UNIX_FD(transport))
{
/* Send the fds along with the first byte of the message */
const int *unix_fds;
unsigned n;
_dbus_message_get_unix_fds(message, &unix_fds, &n);
bytes_written =
_dbus_write_socket_with_unix_fds_two (socket_transport->fd,
header,
socket_transport->message_bytes_written,
header_len - socket_transport->message_bytes_written,
body,
0, body_len,
unix_fds,
n);
if (bytes_written > 0 && n > 0)
_dbus_verbose("Wrote %i unix fds\n", n);
}
else
#endif
{
if (socket_transport->message_bytes_written < header_len)
{
bytes_written =
_dbus_write_socket_two (socket_transport->fd,
header,
socket_transport->message_bytes_written,
header_len - socket_transport->message_bytes_written,
body,
0, body_len);
}
else
{
bytes_written =
_dbus_write_socket (socket_transport->fd,
body,
(socket_transport->message_bytes_written - header_len),
body_len -
(socket_transport->message_bytes_written - header_len));
}
}
}
if (bytes_written < 0)
{
/* EINTR already handled for us */
/* For some discussion of why we also ignore EPIPE here, see
* http://lists.freedesktop.org/archives/dbus/2008-March/009526.html
*/
if (_dbus_get_is_errno_eagain_or_ewouldblock () || _dbus_get_is_errno_epipe ())
goto out;
else
{
_dbus_verbose ("Error writing to remote app: %s\n",
_dbus_strerror_from_errno ());
do_io_error (transport);
goto out;
}
}
else
{
_dbus_verbose (" wrote %d bytes of %d\n", bytes_written,
total_bytes_to_write);
total += bytes_written;
socket_transport->message_bytes_written += bytes_written;
_dbus_assert (socket_transport->message_bytes_written <=
total_bytes_to_write);
if (socket_transport->message_bytes_written == total_bytes_to_write)
{
socket_transport->message_bytes_written = 0;
_dbus_string_set_length (&socket_transport->encoded_outgoing, 0);
_dbus_string_compact (&socket_transport->encoded_outgoing, 2048);
_dbus_connection_message_sent_unlocked (transport->connection,
message);
}
}
}
out:
if (oom)
return FALSE;
else
return TRUE;
}
/* returns false on oom */
static dbus_bool_t
do_writing (DBusTransport *transport)
{
int total;
DBusTransportSocket *socket_transport = (DBusTransportSocket*) transport;
dbus_bool_t oom;
/* No messages without authentication! */
if (!_dbus_transport_try_to_authenticate (transport))
{
_dbus_verbose ("Not authenticated, not writing anything\n");
return TRUE;
}
if (transport->disconnected)
{
_dbus_verbose ("Not connected, not writing anything\n");
return TRUE;
}
#if 1
_dbus_verbose ("do_writing(), have_messages = %d, fd = %" DBUS_SOCKET_FORMAT "\n",
_dbus_connection_has_messages_to_send_unlocked (transport->connection),
_dbus_socket_printable (socket_transport->fd));
#endif
oom = FALSE;
total = 0;
while (!transport->disconnected &&
_dbus_connection_has_messages_to_send_unlocked (transport->connection))
{
int bytes_written;
DBusMessage *message;
const DBusString *header;
const DBusString *body;
int header_len, body_len;
int total_bytes_to_write;
int saved_errno;
if (total > socket_transport->max_bytes_written_per_iteration)
{
_dbus_verbose ("%d bytes exceeds %d bytes written per iteration, returning\n",
total, socket_transport->max_bytes_written_per_iteration);
goto out;
}
message = _dbus_connection_get_message_to_send (transport->connection);
_dbus_assert (message != NULL);
dbus_message_lock (message);
#if 0
_dbus_verbose ("writing message %p\n", message);
#endif
_dbus_message_get_network_data (message,
&header, &body);
header_len = _dbus_string_get_length (header);
body_len = _dbus_string_get_length (body);
if (_dbus_auth_needs_encoding (transport->auth))
{
/* Does fd passing even make sense with encoded data? */
_dbus_assert(!DBUS_TRANSPORT_CAN_SEND_UNIX_FD(transport));
if (_dbus_string_get_length (&socket_transport->encoded_outgoing) == 0)
{
if (!_dbus_auth_encode_data (transport->auth,
header, &socket_transport->encoded_outgoing))
{
oom = TRUE;
goto out;
}
if (!_dbus_auth_encode_data (transport->auth,
body, &socket_transport->encoded_outgoing))
{
_dbus_string_set_length (&socket_transport->encoded_outgoing, 0);
oom = TRUE;
goto out;
}
}
total_bytes_to_write = _dbus_string_get_length (&socket_transport->encoded_outgoing);
#if 0
_dbus_verbose ("encoded message is %d bytes\n",
total_bytes_to_write);
#endif
bytes_written =
_dbus_write_socket (socket_transport->fd,
&socket_transport->encoded_outgoing,
socket_transport->message_bytes_written,
total_bytes_to_write - socket_transport->message_bytes_written);
saved_errno = _dbus_save_socket_errno ();
}
else
{
total_bytes_to_write = header_len + body_len;
#if 0
_dbus_verbose ("message is %d bytes\n",
total_bytes_to_write);
#endif
#ifdef HAVE_UNIX_FD_PASSING
if (socket_transport->message_bytes_written <= 0 && DBUS_TRANSPORT_CAN_SEND_UNIX_FD(transport))
{
/* Send the fds along with the first byte of the message */
const int *unix_fds;
unsigned n;
_dbus_message_get_unix_fds(message, &unix_fds, &n);
bytes_written =
_dbus_write_socket_with_unix_fds_two (socket_transport->fd,
header,
socket_transport->message_bytes_written,
header_len - socket_transport->message_bytes_written,
body,
0, body_len,
unix_fds,
n);
saved_errno = _dbus_save_socket_errno ();
if (bytes_written > 0 && n > 0)
_dbus_verbose("Wrote %i unix fds\n", n);
}
else
#endif
{
if (socket_transport->message_bytes_written < header_len)
{
bytes_written =
_dbus_write_socket_two (socket_transport->fd,
header,
socket_transport->message_bytes_written,
header_len - socket_transport->message_bytes_written,
body,
0, body_len);
}
else
{
bytes_written =
_dbus_write_socket (socket_transport->fd,
body,
(socket_transport->message_bytes_written - header_len),
body_len -
(socket_transport->message_bytes_written - header_len));
}
saved_errno = _dbus_save_socket_errno ();
}
}
if (bytes_written < 0)
{
/* EINTR already handled for us */
/* If the other end closed the socket with close() or shutdown(), we
* receive EPIPE here but we must not close the socket yet: there
* might still be some data to read. See:
* http://lists.freedesktop.org/archives/dbus/2008-March/009526.html
*/
if (_dbus_get_is_errno_eagain_or_ewouldblock (saved_errno) || _dbus_get_is_errno_epipe (saved_errno))
goto out;
/* Since Linux commit 25888e (from 2.6.37-rc4, Nov 2010), sendmsg()
* on Unix sockets returns -1 errno=ETOOMANYREFS when the passfd
* mechanism (SCM_RIGHTS) is used recursively with a recursion level
* of maximum 4. The kernel does not have an API to check whether
* the passed fds can be forwarded and it can change asynchronously.
* See:
* https://bugs.freedesktop.org/show_bug.cgi?id=80163
*/
else if (_dbus_get_is_errno_etoomanyrefs (saved_errno))
{
/* We only send fds in the first byte of the message.
* ETOOMANYREFS cannot happen after.
*/
_dbus_assert (socket_transport->message_bytes_written == 0);
_dbus_verbose (" discard message of %d bytes due to ETOOMANYREFS\n",
total_bytes_to_write);
socket_transport->message_bytes_written = 0;
_dbus_string_set_length (&socket_transport->encoded_outgoing, 0);
_dbus_string_compact (&socket_transport->encoded_outgoing, 2048);
/* The message was not actually sent but it needs to be removed
* from the outgoing queue
*/
_dbus_connection_message_sent_unlocked (transport->connection,
message);
}
else
{
_dbus_verbose ("Error writing to remote app: %s\n",
_dbus_strerror (saved_errno));
do_io_error (transport);
goto out;
}
}
else
{
_dbus_verbose (" wrote %d bytes of %d\n", bytes_written,
total_bytes_to_write);
total += bytes_written;
socket_transport->message_bytes_written += bytes_written;
_dbus_assert (socket_transport->message_bytes_written <=
total_bytes_to_write);
if (socket_transport->message_bytes_written == total_bytes_to_write)
{
socket_transport->message_bytes_written = 0;
_dbus_string_set_length (&socket_transport->encoded_outgoing, 0);
_dbus_string_compact (&socket_transport->encoded_outgoing, 2048);
_dbus_connection_message_sent_unlocked (transport->connection,
message);
}
}
}
out:
if (oom)
return FALSE;
else
return TRUE;
}
/**
* Returns TRUE if the transport supports sending unix fds.
*
* @param transport the transport
* @returns #TRUE if TRUE it is possible to send unix fds across the transport.
*/
dbus_bool_t
_dbus_transport_can_pass_unix_fd(DBusTransport *transport)
{
return DBUS_TRANSPORT_CAN_SEND_UNIX_FD(transport);
}
