/*
* 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;
struct allocated_headers *ah;
char *uri_ptr;
int uri_len;
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);
#ifndef LWS_NO_CLIENT
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++)
if (libwebsocket_client_rx_sm(wsi, *buf++)) {
lwsl_info("client_rx_sm failed\n");
goto bail;
}
return 0;
default:
break;
}
#endif
#ifndef LWS_NO_SERVER
/* LWS_CONNMODE_WS_SERVING */
for (n = 0; n < len; n++)
if (libwebsocket_parse(wsi, *buf++)) {
lwsl_info("libwebsocket_parse failed\n");
goto bail;
}
if (wsi->u.hdr.parser_state != WSI_PARSING_COMPLETE)
break;
lwsl_parser("libwebsocket_parse sees parsing complete\n");
/* is this websocket protocol or normal http 1.0? */
if (!lws_hdr_total_length(wsi, WSI_TOKEN_UPGRADE) ||
!lws_hdr_total_length(wsi, WSI_TOKEN_CONNECTION)) {
/* it's not websocket.... shall we accept it as http? */
if (!lws_hdr_total_length(wsi, WSI_TOKEN_GET_URI)) {
lwsl_warn("Missing URI in HTTP request\n");
/* drop the header info */
if (wsi->u.hdr.ah)
free(wsi->u.hdr.ah);
goto bail;
}
lwsl_info("HTTP request for '%s'\n",
lws_hdr_simple_ptr(wsi, WSI_TOKEN_GET_URI));
if (libwebsocket_ensure_user_space(wsi)) {
/* drop the header info */
if (wsi->u.hdr.ah)
free(wsi->u.hdr.ah);
goto bail;
}
/*
* Hm we still need the headers so the
* callback can look at leaders like the URI, but we
* need to transition to http union state.... hold a
* copy of u.hdr.ah and deallocate afterwards
*/
ah = wsi->u.hdr.ah;
uri_ptr = lws_hdr_simple_ptr(wsi, WSI_TOKEN_GET_URI);
uri_len = lws_hdr_total_length(wsi, WSI_TOKEN_GET_URI);
/* union transition */
memset(&wsi->u, 0, sizeof(wsi->u));
wsi->state = WSI_STATE_HTTP;
n = 0;
if (wsi->protocol->callback)
n = wsi->protocol->callback(context, wsi,
LWS_CALLBACK_HTTP,
wsi->user_space, uri_ptr, uri_len);
/* now drop the header info we kept a pointer to */
if (ah)
free(ah);
if (n) {
lwsl_info("LWS_CALLBACK_HTTP closing\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 (!lws_hdr_total_length(wsi, WSI_TOKEN_PROTOCOL)) {
if (wsi->protocol->name == NULL)
break;
} else
if (wsi->protocol->name && strcmp(
lws_hdr_simple_ptr(wsi,
WSI_TOKEN_PROTOCOL),
wsi->protocol->name) == 0)
break;
wsi->protocol++;
}
/* we didn't find a protocol he wanted? */
if (wsi->protocol->callback == NULL) {
if (lws_hdr_simple_ptr(wsi, WSI_TOKEN_PROTOCOL) ==
NULL) {
lwsl_info("no protocol -> prot 0 handler\n");
wsi->protocol = &context->protocols[0];
} else {
lwsl_err("Req protocol %s not supported\n",
lws_hdr_simple_ptr(wsi, WSI_TOKEN_PROTOCOL));
goto bail;
}
}
/*
* 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,
lws_hdr_simple_ptr(wsi, WSI_TOKEN_PROTOCOL),
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("lws_parse calling handshake_04\n");
if (handshake_0405(context, wsi)) {
lwsl_info("hs0405 has failed the connection\n");
goto bail;
}
break;
default:
lwsl_warn("Unknown client spec version %d\n",
wsi->ietf_spec_revision);
goto bail;
}
/* drop the header info */
if (wsi->u.hdr.ah)
free(wsi->u.hdr.ah);
wsi->mode = LWS_CONNMODE_WS_SERVING;
/* union transition */
memset(&wsi->u, 0, sizeof(wsi->u));
/*
* create the frame buffer for this connection according to the
* size mentioned in the protocol definition. If 0 there, use
* a big default for compatibility
*/
n = wsi->protocol->rx_buffer_size;
if (!n)
n = LWS_MAX_SOCKET_IO_BUF;
n += LWS_SEND_BUFFER_PRE_PADDING + LWS_SEND_BUFFER_POST_PADDING;
wsi->u.ws.rx_user_buffer = malloc(n);
if (!wsi->u.ws.rx_user_buffer) {
lwsl_err("Out of Mem allocating rx buffer %d\n", n);
goto bail;
}
lwsl_info("Allocating RX buffer %d\n", n);
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;
}