/*
* 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.
*/
LWS_VISIBLE int
libwebsocket_read(struct libwebsocket_context *context,
struct libwebsocket *wsi, unsigned char *buf, size_t len)
{
size_t n;
#ifndef LWS_NO_SERVER
struct allocated_headers *ah;
char *uri_ptr = NULL;
int uri_len = 0;
char content_length_str[32];
#endif
switch (wsi->state) {
case WSI_STATE_HTTP_BODY:
#ifndef LWS_NO_SERVER
http_postbody:
#endif
while (len--) {
if (wsi->u.http.content_length_seen >= wsi->u.http.content_length)
break;
wsi->u.http.post_buffer[wsi->u.http.body_index++] = *buf++;
wsi->u.http.content_length_seen++;
n = wsi->protocol->rx_buffer_size;
if (!n)
n = LWS_MAX_SOCKET_IO_BUF;
if (wsi->u.http.body_index != n &&
wsi->u.http.content_length_seen != wsi->u.http.content_length)
continue;
if (wsi->protocol->callback) {
n = wsi->protocol->callback(
wsi->protocol->owning_server, wsi,
LWS_CALLBACK_HTTP_BODY,
wsi->user_space, wsi->u.http.post_buffer,
wsi->u.http.body_index);
wsi->u.http.body_index = 0;
if (n)
goto bail;
}
if (wsi->u.http.content_length_seen == wsi->u.http.content_length) {
/* he sent the content in time */
libwebsocket_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
n = wsi->protocol->callback(
wsi->protocol->owning_server, wsi,
LWS_CALLBACK_HTTP_BODY_COMPLETION,
wsi->user_space, NULL, 0);
wsi->u.http.body_index = 0;
if (n)
goto bail;
}
}
/*
* we need to spill here so everything is seen in the case
* there is no content-length
*/
if (wsi->u.http.body_index && wsi->protocol->callback) {
n = wsi->protocol->callback(
wsi->protocol->owning_server, wsi,
LWS_CALLBACK_HTTP_BODY,
wsi->user_space, wsi->u.http.post_buffer,
wsi->u.http.body_index);
wsi->u.http.body_index = 0;
if (n)
goto bail;
}
break;
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 */
while (len--) {
if (libwebsocket_parse(wsi, *buf++)) {
lwsl_info("libwebsocket_parse failed\n");
goto bail_nuke_ah;
}
if (wsi->u.hdr.parser_state != WSI_PARSING_COMPLETE)
continue;
lwsl_parser("libwebsocket_parse sees parsing complete\n");
wsi->mode = LWS_CONNMODE_PRE_WS_SERVING_ACCEPT;
libwebsocket_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
/* 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) &&
!lws_hdr_total_length(wsi, WSI_TOKEN_POST_URI)) {
lwsl_warn("Missing URI in HTTP request\n");
goto bail_nuke_ah;
}
if (lws_hdr_total_length(wsi, WSI_TOKEN_GET_URI) &&
lws_hdr_total_length(wsi, WSI_TOKEN_POST_URI)) {
lwsl_warn("GET and POST methods?\n");
goto bail_nuke_ah;
}
if (libwebsocket_ensure_user_space(wsi))
goto bail_nuke_ah;
if (lws_hdr_total_length(wsi, WSI_TOKEN_GET_URI)) {
uri_ptr = lws_hdr_simple_ptr(wsi, WSI_TOKEN_GET_URI);
uri_len = lws_hdr_total_length(wsi, WSI_TOKEN_GET_URI);
lwsl_info("HTTP GET request for '%s'\n",
lws_hdr_simple_ptr(wsi, WSI_TOKEN_GET_URI));
}
if (lws_hdr_total_length(wsi, WSI_TOKEN_POST_URI)) {
lwsl_info("HTTP POST request for '%s'\n",
lws_hdr_simple_ptr(wsi, WSI_TOKEN_POST_URI));
uri_ptr = lws_hdr_simple_ptr(wsi, WSI_TOKEN_POST_URI);
uri_len = lws_hdr_total_length(wsi, WSI_TOKEN_POST_URI);
}
/*
* 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;
/* union transition */
memset(&wsi->u, 0, sizeof(wsi->u));
wsi->mode = LWS_CONNMODE_HTTP_SERVING_ACCEPTED;
wsi->state = WSI_STATE_HTTP;
wsi->u.http.fd = LWS_INVALID_FILE;
/* expose it at the same offset as u.hdr */
wsi->u.http.ah = ah;
/* HTTP header had a content length? */
wsi->u.http.content_length = 0;
if (lws_hdr_total_length(wsi, WSI_TOKEN_POST_URI))
wsi->u.http.content_length = 100 * 1024 * 1024;
if (lws_hdr_total_length(wsi, WSI_TOKEN_HTTP_CONTENT_LENGTH)) {
lws_hdr_copy(wsi, content_length_str,
sizeof(content_length_str) - 1,
WSI_TOKEN_HTTP_CONTENT_LENGTH);
wsi->u.http.content_length = atoi(content_length_str);
}
if (wsi->u.http.content_length > 0) {
wsi->u.http.body_index = 0;
n = wsi->protocol->rx_buffer_size;
if (!n)
n = LWS_MAX_SOCKET_IO_BUF;
wsi->u.http.post_buffer = malloc(n);
if (!wsi->u.http.post_buffer) {
lwsl_err("Unable to allocate post buffer\n");
n = -1;
goto cleanup;
}
}
n = 0;
if (wsi->protocol->callback)
n = wsi->protocol->callback(context, wsi,
LWS_CALLBACK_FILTER_HTTP_CONNECTION,
wsi->user_space, uri_ptr, uri_len);
if (!n) {
/*
* if there is content supposed to be coming,
* put a timeout on it having arrived
*/
libwebsocket_set_timeout(wsi,
PENDING_TIMEOUT_HTTP_CONTENT,
AWAITING_TIMEOUT);
if (wsi->protocol->callback)
n = wsi->protocol->callback(context, wsi,
LWS_CALLBACK_HTTP,
wsi->user_space, uri_ptr, uri_len);
}
cleanup:
/* now drop the header info we kept a pointer to */
if (ah)
free(ah);
/* not possible to continue to use past here */
wsi->u.http.ah = NULL;
if (n) {
lwsl_info("LWS_CALLBACK_HTTP closing\n");
goto bail; /* struct ah ptr already nuked */
}
/*
* (if callback didn't start sending a file)
* deal with anything else as body, whether
* there was a content-length or not
*/
if (wsi->state != WSI_STATE_HTTP_ISSUING_FILE)
wsi->state = WSI_STATE_HTTP_BODY;
goto http_postbody;
}
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_nuke_ah;
}
}
/* allocate wsi->user storage */
if (libwebsocket_ensure_user_space(wsi))
goto bail_nuke_ah;
/*
* 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->user_space,
lws_hdr_simple_ptr(wsi, WSI_TOKEN_PROTOCOL), 0)) {
lwsl_warn("User code denied connection\n");
goto bail_nuke_ah;
}
/*
* 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_nuke_ah;
}
break;
default:
lwsl_warn("Unknown client spec version %d\n",
wsi->ietf_spec_revision);
goto bail_nuke_ah;
}
/* drop the header info -- no bail_nuke_ah after this */
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));
wsi->u.ws.rxflow_change_to = LWS_RXFLOW_ALLOW;
/*
* 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);
if (setsockopt(wsi->sock, SOL_SOCKET, SO_SNDBUF, &n, sizeof n)) {
lwsl_warn("Failed to set SNDBUF to %d", n);
goto bail;
}
lwsl_parser("accepted v%02d connection\n",
wsi->ietf_spec_revision);
} /* while all chars are handled */
break;
#endif
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;
#ifndef LWS_NO_SERVER
bail_nuke_ah:
/* drop the header info */
if (wsi->u.hdr.ah)
free(wsi->u.hdr.ah);
#endif
bail:
lwsl_info("closing connection at libwebsocket_read bail:\n");
libwebsocket_close_and_free_session(context, wsi,
LWS_CLOSE_STATUS_NOSTATUS);
return -1;
}