281 lines
7.2 KiB
C
281 lines
7.2 KiB
C
/*
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* libwebsockets - small server side websockets and web server implementation
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*
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* Copyright (C) 2010-2017 Andy Green <andy@warmcat.com>
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation:
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* version 2.1 of the License.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
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* MA 02110-1301 USA
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*/
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#include "private-libwebsockets.h"
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/*
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* -04 of the protocol (actually the 80th version) has a radically different
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* handshake. The 04 spec gives the following idea
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*
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* The handshake from the client looks as follows:
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*
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* GET /chat HTTP/1.1
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* Host: server.example.com
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* Upgrade: websocket
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* Connection: Upgrade
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* Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ==
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* Sec-WebSocket-Origin: http://example.com
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* Sec-WebSocket-Protocol: chat, superchat
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* Sec-WebSocket-Version: 4
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*
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* The handshake from the server looks as follows:
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*
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* HTTP/1.1 101 Switching Protocols
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* Upgrade: websocket
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* Connection: Upgrade
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* Sec-WebSocket-Accept: me89jWimTRKTWwrS3aRrL53YZSo=
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* Sec-WebSocket-Nonce: AQIDBAUGBwgJCgsMDQ4PEC==
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* Sec-WebSocket-Protocol: chat
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*/
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#ifndef min
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#define min(a, b) ((a) < (b) ? (a) : (b))
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#endif
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/*
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* We have to take care about parsing because the headers may be split
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* into multiple fragments. They may contain unknown headers with arbitrary
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* argument lengths. So, we parse using a single-character at a time state
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* machine that is completely independent of packet size.
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*
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* Returns <0 for error or length of chars consumed from buf (up to len)
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*/
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LWS_VISIBLE int
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lws_read(struct lws *wsi, unsigned char *buf, lws_filepos_t len)
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{
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unsigned char *last_char, *oldbuf = buf;
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lws_filepos_t body_chunk_len;
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size_t n;
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switch (wsi->state) {
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#ifdef LWS_WITH_HTTP2
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case LWSS_HTTP2_AWAIT_CLIENT_PREFACE:
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case LWSS_HTTP2_ESTABLISHED_PRE_SETTINGS:
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case LWSS_HTTP2_ESTABLISHED:
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n = 0;
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//lwsl_debug("%s: starting new block of %d\n", __func__, (int)len);
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/*
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* wsi here is always the network connection wsi, not a stream
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* wsi.
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*/
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while (n < len) {
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/*
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* we were accepting input but now we stopped doing so
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*/
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if (lws_is_flowcontrolled(wsi)) {
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lws_rxflow_cache(wsi, buf, n, len);
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return 1;
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}
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/* account for what we're using in rxflow buffer */
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if (wsi->rxflow_buffer) {
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wsi->rxflow_pos++;
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assert(wsi->rxflow_pos <= wsi->rxflow_len);
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}
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if (lws_h2_parser(wsi, buf[n++])) {
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lwsl_debug("%s: http2_parser bailed\n", __func__);
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goto bail;
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}
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}
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lwsl_debug("%s: used up block of %d\n", __func__, (int)len);
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break;
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#endif
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case LWSS_HTTP_ISSUING_FILE:
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return 0;
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case LWSS_CLIENT_HTTP_ESTABLISHED:
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break;
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case LWSS_HTTP:
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wsi->hdr_parsing_completed = 0;
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/* fallthru */
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case LWSS_HTTP_HEADERS:
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if (!wsi->u.hdr.ah) {
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lwsl_err("%s: LWSS_HTTP_HEADERS: NULL ah\n", __func__);
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assert(0);
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}
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lwsl_parser("issuing %d bytes to parser\n", (int)len);
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lwsl_hexdump(buf, (size_t)len);
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if (lws_handshake_client(wsi, &buf, (size_t)len))
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goto bail;
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last_char = buf;
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if (lws_handshake_server(wsi, &buf, (size_t)len))
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/* Handshake indicates this session is done. */
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goto bail;
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/* we might have transitioned to RAW */
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if (wsi->mode == LWSCM_RAW)
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/* we gave the read buffer to RAW handler already */
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goto read_ok;
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/*
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* It's possible that we've exhausted our data already, or
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* rx flow control has stopped us dealing with this early,
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* but lws_handshake_server doesn't update len for us.
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* Figure out how much was read, so that we can proceed
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* appropriately:
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*/
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len -= (buf - last_char);
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lwsl_debug("%s: thinks we have used %ld\n", __func__, (long)len);
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if (!wsi->hdr_parsing_completed)
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/* More header content on the way */
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goto read_ok;
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switch (wsi->state) {
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case LWSS_HTTP:
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case LWSS_HTTP_HEADERS:
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goto read_ok;
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case LWSS_HTTP_ISSUING_FILE:
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goto read_ok;
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case LWSS_HTTP_BODY:
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wsi->u.http.rx_content_remain =
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wsi->u.http.rx_content_length;
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if (wsi->u.http.rx_content_remain)
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goto http_postbody;
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/* there is no POST content */
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goto postbody_completion;
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default:
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break;
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}
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break;
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case LWSS_HTTP_BODY:
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http_postbody:
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//lwsl_notice("http post body\n");
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while (len && wsi->u.http.rx_content_remain) {
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/* Copy as much as possible, up to the limit of:
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* what we have in the read buffer (len)
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* remaining portion of the POST body (content_remain)
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*/
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body_chunk_len = min(wsi->u.http.rx_content_remain, len);
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wsi->u.http.rx_content_remain -= body_chunk_len;
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len -= body_chunk_len;
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#ifdef LWS_WITH_CGI
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if (wsi->cgi) {
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struct lws_cgi_args args;
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args.ch = LWS_STDIN;
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args.stdwsi = &wsi->cgi->stdwsi[0];
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args.data = buf;
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args.len = body_chunk_len;
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/* returns how much used */
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n = user_callback_handle_rxflow(
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wsi->protocol->callback,
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wsi, LWS_CALLBACK_CGI_STDIN_DATA,
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wsi->user_space,
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(void *)&args, 0);
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if ((int)n < 0)
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goto bail;
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} else {
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#endif
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n = wsi->protocol->callback(wsi,
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LWS_CALLBACK_HTTP_BODY, wsi->user_space,
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buf, (size_t)body_chunk_len);
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if (n)
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goto bail;
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n = (size_t)body_chunk_len;
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#ifdef LWS_WITH_CGI
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}
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#endif
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buf += n;
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if (wsi->u.http.rx_content_remain) {
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lws_set_timeout(wsi, PENDING_TIMEOUT_HTTP_CONTENT,
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wsi->context->timeout_secs);
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break;
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}
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/* he sent all the content in time */
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postbody_completion:
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#ifdef LWS_WITH_CGI
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/*
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* If we're running a cgi, we can't let him off the
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* hook just because he sent his POST data
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*/
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if (wsi->cgi)
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lws_set_timeout(wsi, PENDING_TIMEOUT_CGI,
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wsi->context->timeout_secs);
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else
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#endif
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lws_set_timeout(wsi, NO_PENDING_TIMEOUT, 0);
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#ifdef LWS_WITH_CGI
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if (!wsi->cgi)
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#endif
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{
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lwsl_notice("LWS_CALLBACK_HTTP_BODY_COMPLETION\n");
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n = wsi->protocol->callback(wsi,
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LWS_CALLBACK_HTTP_BODY_COMPLETION,
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wsi->user_space, NULL, 0);
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if (n)
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goto bail;
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if (wsi->http2_substream)
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wsi->state = LWSS_HTTP2_ESTABLISHED;
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}
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break;
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}
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break;
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case LWSS_ESTABLISHED:
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case LWSS_AWAITING_CLOSE_ACK:
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case LWSS_WAITING_TO_SEND_CLOSE_NOTIFICATION:
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case LWSS_SHUTDOWN:
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if (lws_handshake_client(wsi, &buf, (size_t)len))
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goto bail;
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switch (wsi->mode) {
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case LWSCM_WS_SERVING:
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if (lws_interpret_incoming_packet(wsi, &buf, (size_t)len) < 0) {
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lwsl_info("interpret_incoming_packet has bailed\n");
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goto bail;
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}
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break;
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}
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break;
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default:
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lwsl_err("%s: Unhandled state %d\n", __func__, wsi->state);
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break;
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}
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read_ok:
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/* Nothing more to do for now */
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lwsl_info("%s: read_ok, used %ld\n", __func__, (long)(buf - oldbuf));
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return buf - oldbuf;
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bail:
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lws_close_free_wsi(wsi, LWS_CLOSE_STATUS_NOSTATUS);
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return -1;
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}
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