/*
* 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"
#define LWS_CPYAPP(ptr, str) { strcpy(ptr, str); ptr += strlen(str); }
#ifndef LWS_NO_EXTENSIONS
LWS_VISIBLE int
lws_extension_server_handshake(struct lws *wsi, char **p)
{
int n;
char *c;
char ext_name[128];
const struct lws_extension *ext;
struct lws_context *context = wsi->context;
int ext_count = 0;
int more = 1;
/*
* Figure out which extensions the client has that we want to
* enable on this connection, and give him back the list
*/
if (!lws_hdr_total_length(wsi, WSI_TOKEN_EXTENSIONS))
return 0;
/*
* break down the list of client extensions
* and go through them
*/
if (lws_hdr_copy(wsi, (char *)context->serv_buf,
sizeof(context->serv_buf),
WSI_TOKEN_EXTENSIONS) < 0)
return 1;
c = (char *)context->serv_buf;
lwsl_parser("WSI_TOKEN_EXTENSIONS = '%s'\n", c);
wsi->count_active_extensions = 0;
n = 0;
while (more) {
if (*c && (*c != ',' && *c != ' ' && *c != '\t')) {
ext_name[n] = *c++;
if (n < sizeof(ext_name) - 1)
n++;
continue;
}
ext_name[n] = '\0';
if (!*c)
more = 0;
else {
c++;
if (!n)
continue;
}
/* check a client's extension against our support */
ext = lws_get_context(wsi)->extensions;
while (ext && ext->callback) {
if (strcmp(ext_name, ext->name)) {
ext++;
continue;
}
/*
* oh, we do support this one he asked for... but let's
* ask user code if it's OK to apply it on this
* particular connection + protocol
*/
n = lws_get_context(wsi)->protocols[0].callback(wsi,
LWS_CALLBACK_CONFIRM_EXTENSION_OKAY,
wsi->user_space, ext_name, 0);
/*
* zero return from callback means go ahead and allow
* the extension, it's what we get if the callback is
* unhandled
*/
if (n) {
ext++;
continue;
}
/* apply it */
if (ext_count)
*(*p)++ = ',';
else
LWS_CPYAPP(*p,
"\x0d\x0aSec-WebSocket-Extensions: ");
*p += sprintf(*p, "%s", ext_name);
ext_count++;
/* instantiate the extension on this conn */
wsi->active_extensions_user[
wsi->count_active_extensions] =
lws_zalloc(ext->per_session_data_size);
if (wsi->active_extensions_user[
wsi->count_active_extensions] == NULL) {
lwsl_err("Out of mem\n");
return 1;
}
wsi->active_extensions[
wsi->count_active_extensions] = ext;
/* allow him to construct his context */
ext->callback(lws_get_context(wsi),
ext, wsi,
LWS_EXT_CALLBACK_CONSTRUCT,
wsi->active_extensions_user[
wsi->count_active_extensions], NULL, 0);
wsi->count_active_extensions++;
lwsl_parser("count_active_extensions <- %d\n",
wsi->count_active_extensions);
ext++;
}
n = 0;
}
return 0;
}
#endif
int
handshake_0405(struct lws_context *context, struct lws *wsi)
{
unsigned char hash[20];
int n;
char *response;
char *p;
int accept_len;
if (!lws_hdr_total_length(wsi, WSI_TOKEN_HOST) ||
!lws_hdr_total_length(wsi, WSI_TOKEN_KEY)) {
lwsl_parser("handshake_04 missing pieces\n");
/* completed header processing, but missing some bits */
goto bail;
}
if (lws_hdr_total_length(wsi, WSI_TOKEN_KEY) >=
MAX_WEBSOCKET_04_KEY_LEN) {
lwsl_warn("Client key too long %d\n", MAX_WEBSOCKET_04_KEY_LEN);
goto bail;
}
/*
* since key length is restricted above (currently 128), cannot
* overflow
*/
n = sprintf((char *)context->serv_buf,
"%s258EAFA5-E914-47DA-95CA-C5AB0DC85B11",
lws_hdr_simple_ptr(wsi, WSI_TOKEN_KEY));
lws_SHA1(context->serv_buf, n, hash);
accept_len = lws_b64_encode_string((char *)hash, 20,
(char *)context->serv_buf,
sizeof(context->serv_buf));
if (accept_len < 0) {
lwsl_warn("Base64 encoded hash too long\n");
goto bail;
}
/* allocate the per-connection user memory (if any) */
if (lws_ensure_user_space(wsi))
goto bail;
/* create the response packet */
/* make a buffer big enough for everything */
response = (char *)context->serv_buf + MAX_WEBSOCKET_04_KEY_LEN + LWS_SEND_BUFFER_PRE_PADDING;
p = response;
LWS_CPYAPP(p, "HTTP/1.1 101 Switching Protocols\x0d\x0a"
"Upgrade: WebSocket\x0d\x0a"
"Connection: Upgrade\x0d\x0a"
"Sec-WebSocket-Accept: ");
strcpy(p, (char *)context->serv_buf);
p += accept_len;
if (lws_hdr_total_length(wsi, WSI_TOKEN_PROTOCOL)) {
LWS_CPYAPP(p, "\x0d\x0aSec-WebSocket-Protocol: ");
n = lws_hdr_copy(wsi, p, 128, WSI_TOKEN_PROTOCOL);
if (n < 0)
goto bail;
p += n;
}
#ifndef LWS_NO_EXTENSIONS
/*
* Figure out which extensions the client has that we want to
* enable on this connection, and give him back the list
*/
if (lws_extension_server_handshake(wsi, &p))
goto bail;
#endif
//LWS_CPYAPP(p, "\x0d\x0a""An-unknown-header: blah");
/* end of response packet */
LWS_CPYAPP(p, "\x0d\x0a\x0d\x0a");
if (!lws_any_extension_handled(wsi, LWS_EXT_CALLBACK_HANDSHAKE_REPLY_TX,
response, p - response)) {
/* okay send the handshake response accepting the connection */
lwsl_parser("issuing resp pkt %d len\n", (int)(p - response));
#ifdef DEBUG
fwrite(response, 1, p - response, stderr);
#endif
n = lws_write(wsi, (unsigned char *)response,
p - response, LWS_WRITE_HTTP_HEADERS);
if (n != (p - response)) {
lwsl_debug("handshake_0405: ERROR writing to socket\n");
goto bail;
}
}
/* alright clean up and set ourselves into established state */
wsi->state = LWSS_ESTABLISHED;
wsi->lws_rx_parse_state = LWS_RXPS_NEW;
/* notify user code that we're ready to roll */
if (wsi->protocol->callback)
if (wsi->protocol->callback(wsi, LWS_CALLBACK_ESTABLISHED,
wsi->user_space,
#ifdef LWS_OPENSSL_SUPPORT
wsi->ssl,
#else
NULL,
#endif
0))
goto bail;
return 0;
bail:
/* free up his parsing allocations */
lws_free_header_table(wsi);
return -1;
}