/*
* libwebsockets - small server side websockets and web server implementation
*
* Copyright (C) 2010-2013 Andy Green <andy@warmcat.com>
*
* 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:
* version 2.1 of the License.
*
* 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
*/
#include "private-libwebsockets.h"
/*
* -04 of the protocol (actually the 80th version) has a radically different
* handshake. The 04 spec gives the following idea
*
* The handshake from the client looks as follows:
*
* GET /chat HTTP/1.1
* Host: server.example.com
* Upgrade: websocket
* Connection: Upgrade
* Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ==
* Sec-WebSocket-Origin: http://example.com
* Sec-WebSocket-Protocol: chat, superchat
* Sec-WebSocket-Version: 4
*
* The handshake from the server looks as follows:
*
* HTTP/1.1 101 Switching Protocols
* Upgrade: websocket
* Connection: Upgrade
* Sec-WebSocket-Accept: me89jWimTRKTWwrS3aRrL53YZSo=
* Sec-WebSocket-Nonce: AQIDBAUGBwgJCgsMDQ4PEC==
* Sec-WebSocket-Protocol: chat
*/
/*
* We have to take care about parsing because the headers may be split
* into multiple fragments. They may contain unknown headers with arbitrary
* argument lengths. So, we parse using a single-character at a time state
* machine that is completely independent of packet size.
*/
int
libwebsocket_read(struct libwebsocket_context *context,
struct libwebsocket *wsi, unsigned char * buf, size_t len)
{
size_t n;
switch (wsi->state) {
case WSI_STATE_HTTP_ISSUING_FILE:
case WSI_STATE_HTTP:
wsi->state = WSI_STATE_HTTP_HEADERS;
wsi->u.hdr.parser_state = WSI_TOKEN_NAME_PART;
wsi->u.hdr.lextable_pos = 0;
/* fallthru */
case WSI_STATE_HTTP_HEADERS:
lwsl_parser("issuing %d bytes to parser\n", (int)len);
#ifdef _DEBUG
//fwrite(buf, 1, len, stderr);
#endif
#ifndef LWS_NO_CLIENT
// lwsl_info("mode=%d\n", wsi->mode);
switch (wsi->mode) {
case LWS_CONNMODE_WS_CLIENT_WAITING_PROXY_REPLY:
case LWS_CONNMODE_WS_CLIENT_ISSUE_HANDSHAKE:
case LWS_CONNMODE_WS_CLIENT_WAITING_SERVER_REPLY:
case LWS_CONNMODE_WS_CLIENT_WAITING_EXTENSION_CONNECT:
case LWS_CONNMODE_WS_CLIENT:
for (n = 0; n < len; n++)
libwebsocket_client_rx_sm(wsi, *buf++);
return 0;
default:
break;
}
#endif
#ifndef LWS_NO_SERVER
/* LWS_CONNMODE_WS_SERVING */
extern int handshake_0405(struct libwebsocket_context *context, struct libwebsocket *wsi);
for (n = 0; n < len; n++)
libwebsocket_parse(wsi, *buf++);
if (wsi->u.hdr.parser_state != WSI_PARSING_COMPLETE)
break;
lwsl_parser("seem to be serving, mode is %d\n", wsi->mode);
lwsl_parser("libwebsocket_parse sees parsing complete\n");
/* is this websocket protocol or normal http 1.0? */
if (!wsi->utf8_token[WSI_TOKEN_UPGRADE].token_len ||
!wsi->utf8_token[WSI_TOKEN_CONNECTION].token_len) {
wsi->state = WSI_STATE_HTTP;
if (wsi->protocol->callback)
if (wsi->protocol->callback(context, wsi,
LWS_CALLBACK_HTTP, wsi->user_space,
wsi->utf8_token[WSI_TOKEN_GET_URI].token,
wsi->utf8_token[WSI_TOKEN_GET_URI].token_len)) {
lwsl_info("LWS_CALLBACK_HTTP wanted to close\n");
goto bail;
}
return 0;
}
if (!wsi->protocol)
lwsl_err("NULL protocol at libwebsocket_read\n");
/*
* It's websocket
*
* Make sure user side is happy about protocol
*/
while (wsi->protocol->callback) {
if (wsi->utf8_token[WSI_TOKEN_PROTOCOL].token == NULL) {
if (wsi->protocol->name == NULL)
break;
} else
if (wsi->protocol->name && strcmp(
wsi->utf8_token[WSI_TOKEN_PROTOCOL].token,
wsi->protocol->name) == 0)
break;
wsi->protocol++;
}
/* we didn't find a protocol he wanted? */
if (wsi->protocol->callback == NULL) {
if (wsi->utf8_token[WSI_TOKEN_PROTOCOL].token == NULL) {
lwsl_info("[no protocol] "
"mapped to protocol 0 handler\n");
wsi->protocol = &context->protocols[0];
} else {
lwsl_err("Requested protocol %s "
"not supported\n",
wsi->utf8_token[WSI_TOKEN_PROTOCOL].token);
goto bail;
}
}
/*
* find out which spec version the client is using
* if this header is not given, we default to 00 (aka 76)
*/
if (wsi->utf8_token[WSI_TOKEN_VERSION].token_len)
wsi->ietf_spec_revision =
atoi(wsi->utf8_token[WSI_TOKEN_VERSION].token);
/*
* Give the user code a chance to study the request and
* have the opportunity to deny it
*/
if ((wsi->protocol->callback)(wsi->protocol->owning_server, wsi,
LWS_CALLBACK_FILTER_PROTOCOL_CONNECTION,
&wsi->utf8_token[0], NULL, 0)) {
lwsl_warn("User code denied connection\n");
goto bail;
}
/*
* Perform the handshake according to the protocol version the
* client announced
*/
switch (wsi->ietf_spec_revision) {
case 13:
lwsl_parser("libwebsocket_parse calling handshake_04\n");
if (handshake_0405(context, wsi)) {
lwsl_info("handshake_0405 xor 05 has failed the connection\n");
goto bail;
}
break;
default:
lwsl_warn("Unknown client spec version %d\n",
wsi->ietf_spec_revision);
goto bail;
}
wsi->mode = LWS_CONNMODE_WS_SERVING;
/* union transition */
memset(&wsi->u, 0, sizeof wsi->u);
lwsl_parser("accepted v%02d connection\n",
wsi->ietf_spec_revision);
#endif
break;
case WSI_STATE_AWAITING_CLOSE_ACK:
case WSI_STATE_ESTABLISHED:
#ifndef LWS_NO_CLIENT
switch (wsi->mode) {
case LWS_CONNMODE_WS_CLIENT:
for (n = 0; n < len; n++)
if (libwebsocket_client_rx_sm(wsi, *buf++) < 0) {
lwsl_info("client rx has bailed\n");
goto bail;
}
return 0;
default:
break;
}
#endif
#ifndef LWS_NO_SERVER
/* LWS_CONNMODE_WS_SERVING */
if (libwebsocket_interpret_incoming_packet(wsi, buf, len) < 0) {
lwsl_info("interpret_incoming_packet has bailed\n");
goto bail;
}
#endif
break;
default:
lwsl_err("libwebsocket_read: Unhandled state\n");
break;
}
return 0;
bail:
lwsl_info("closing connection at libwebsocket_read bail:\n");
libwebsocket_close_and_free_session(context, wsi,
LWS_CLOSE_STATUS_NOSTATUS);
return -1;
}