/*
* 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
*/
#ifndef min
#define min(a, b) ((a) < (b) ? (a) : (b))
#endif
/*
* 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.
*/
LWS_VISIBLE int
libwebsocket_read(struct libwebsocket_context *context,
struct libwebsocket *wsi, unsigned char *buf, size_t len)
{
size_t n;
int body_chunk_len;
unsigned char *last_char;
switch (wsi->state) {
#ifdef LWS_USE_HTTP2
case WSI_STATE_HTTP2_AWAIT_CLIENT_PREFACE:
case WSI_STATE_HTTP2_ESTABLISHED_PRE_SETTINGS:
case WSI_STATE_HTTP2_ESTABLISHED:
n = 0;
while (n < len) {
/*
* we were accepting input but now we stopped doing so
*/
if (!(wsi->rxflow_change_to & LWS_RXFLOW_ALLOW)) {
lws_rxflow_cache(wsi, buf, n, len);
return 1;
}
/* account for what we're using in rxflow buffer */
if (wsi->rxflow_buffer)
wsi->rxflow_pos++;
if (lws_http2_parser(context, wsi, buf[n++]))
goto bail;
}
break;
#endif
http_new:
case WSI_STATE_HTTP:
wsi->hdr_parsing_completed = 0;
/* fallthru */
case WSI_STATE_HTTP_ISSUING_FILE:
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);
if (lws_handshake_client(wsi, &buf, len))
goto bail;
last_char = buf;
if (lws_handshake_server(context, wsi, &buf, len))
/* Handshake indicates this session is done. */
goto bail;
/* It's possible that we've exhausted our data already, but
* lws_handshake_server doesn't update len for us. Figure out how
* much was read, so that we can proceed appropriately: */
len -= (buf - last_char);
if (!wsi->hdr_parsing_completed)
/* More header content on the way */
goto read_ok;
switch (wsi->state) {
case WSI_STATE_HTTP:
case WSI_STATE_HTTP_HEADERS:
goto http_complete;
case WSI_STATE_HTTP_ISSUING_FILE:
goto read_ok;
case WSI_STATE_HTTP_BODY:
wsi->u.http.content_remain = wsi->u.http.content_length;
goto http_postbody;
default:
break;
}
break;
case WSI_STATE_HTTP_BODY:
http_postbody:
while (len && wsi->u.http.content_remain) {
/* Copy as much as possible, up to the limit of:
* what we have in the read buffer (len)
* remaining portion of the POST body (content_remain)
*/
body_chunk_len = min(wsi->u.http.content_remain,len);
wsi->u.http.content_remain -= body_chunk_len;
len -= body_chunk_len;
if (wsi->protocol->callback) {
n = wsi->protocol->callback(
wsi->protocol->owning_server, wsi,
LWS_CALLBACK_HTTP_BODY, wsi->user_space,
buf, body_chunk_len);
if (n)
goto bail;
}
buf += body_chunk_len;
if (!wsi->u.http.content_remain) {
/* he sent the content in time */
libwebsocket_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
if (wsi->protocol->callback) {
n = wsi->protocol->callback(
wsi->protocol->owning_server, wsi,
LWS_CALLBACK_HTTP_BODY_COMPLETION,
wsi->user_space, NULL, 0);
if (n)
goto bail;
}
goto http_complete;
} else
libwebsocket_set_timeout(wsi,
PENDING_TIMEOUT_HTTP_CONTENT,
AWAITING_TIMEOUT);
}
break;
case WSI_STATE_ESTABLISHED:
case WSI_STATE_AWAITING_CLOSE_ACK:
if (lws_handshake_client(wsi, &buf, len))
goto bail;
switch (wsi->mode) {
case LWS_CONNMODE_WS_SERVING:
if (libwebsocket_interpret_incoming_packet(wsi, buf, len) < 0) {
lwsl_info("interpret_incoming_packet has bailed\n");
goto bail;
}
break;
}
break;
default:
lwsl_err("libwebsocket_read: Unhandled state\n");
break;
}
read_ok:
/* Nothing more to do for now. */
lwsl_debug("libwebsocket_read: read_ok\n");
return 0;
http_complete:
lwsl_debug("libwebsocket_read: http_complete\n");
/* Did the client want to keep the HTTP connection going? */
if (wsi->u.http.connection_type == HTTP_CONNECTION_KEEP_ALIVE) {
lwsl_debug("libwebsocket_read: keep-alive\n");
wsi->state = WSI_STATE_HTTP;
wsi->mode = LWS_CONNMODE_HTTP_SERVING;
/* He asked for it to stay alive indefinitely */
libwebsocket_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
if (lws_allocate_header_table(wsi))
goto bail;
/* If we're (re)starting on headers, need other implied init */
wsi->u.hdr.ues = URIES_IDLE;
/* If we have more data, loop back around: */
if (len)
goto http_new;
return 0;
}
bail:
lwsl_debug("closing connection at libwebsocket_read bail:\n");
libwebsocket_close_and_free_session(context, wsi,
LWS_CLOSE_STATUS_NOSTATUS);
return -1;
}