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/*
This file is part of libmicrohttpd
Copyright (C) 2007-2018 Daniel Pittman and Christian Grothoff
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file lib/response_for_upgrade.c
* @brief implementation of MHD_response_for_upgrade()
* @author Christian Grothoff
*/
#include "internal.h"
/**
* Create a response object that can be used for 101 UPGRADE
* responses, for example to implement WebSockets. After sending the
* response, control over the data stream is given to the callback (which
* can then, for example, start some bi-directional communication).
* If the response is queued for multiple connections, the callback
* will be called for each connection. The callback
* will ONLY be called after the response header was successfully passed
* to the OS; if there are communication errors before, the usual MHD
* connection error handling code will be performed.
*
* MHD will automatically set the correct HTTP status
* code (#MHD_HTTP_SWITCHING_PROTOCOLS).
* Setting correct HTTP headers for the upgrade must be done
* manually (this way, it is possible to implement most existing
* WebSocket versions using this API; in fact, this API might be useful
* for any protocol switch, not just WebSockets). Note that
* draft-ietf-hybi-thewebsocketprotocol-00 cannot be implemented this
* way as the header "HTTP/1.1 101 WebSocket Protocol Handshake"
* cannot be generated; instead, MHD will always produce "HTTP/1.1 101
* Switching Protocols" (if the response code 101 is used).
*
* As usual, the response object can be extended with header
* information and then be used any number of times (as long as the
* header information is not connection-specific).
*
* @param upgrade_handler function to call with the "upgraded" socket
* @param upgrade_handler_cls closure for @a upgrade_handler
* @return NULL on error (i.e. invalid arguments, out of memory)
*/
struct MHD_Response *
MHD_response_for_upgrade (MHD_UpgradeHandler upgrade_handler,
void *upgrade_handler_cls)
{
struct MHD_Response *response;
mhd_assert (NULL != upgrade_handler);
response = MHD_calloc_ (1,
sizeof (struct MHD_Response));
if (NULL == response)
return NULL;
if (! MHD_mutex_init_ (&response->mutex))
{
free (response);
return NULL;
}
response->upgrade_handler = upgrade_handler;
response->upgrade_handler_cls = upgrade_handler_cls;
response->status_code = MHD_HTTP_SWITCHING_PROTOCOLS;
response->total_size = MHD_SIZE_UNKNOWN;
response->reference_count = 1;
if (MHD_NO ==
MHD_add_response_header (response,
MHD_HTTP_HEADER_CONNECTION,
"Upgrade"))
{
MHD_destroy_response (response);
return NULL;
}
return response;
}
/* end of response_for_upgrade.c */
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