/*
* 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
static int
lws_extension_server_handshake(struct lws *wsi, char **p, int budget)
{
struct lws_context *context = wsi->context;
struct lws_context_per_thread *pt = &context->pt[(int)wsi->tsi];
char ext_name[64], *args, *end = (*p) + budget - 1;
const struct lws_ext_options *opts, *po;
const struct lws_extension *ext;
struct lws_ext_option_arg oa;
int n, m, more = 1;
int ext_count = 0;
char ignore;
char *c;
/*
* 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 *)pt->serv_buf, context->pt_serv_buf_size,
WSI_TOKEN_EXTENSIONS) < 0)
return 1;
c = (char *)pt->serv_buf;
lwsl_parser("WSI_TOKEN_EXTENSIONS = '%s'\n", c);
wsi->count_act_ext = 0;
ignore = 0;
n = 0;
args = NULL;
/*
* We may get a simple request
*
* Sec-WebSocket-Extensions: permessage-deflate
*
* or an elaborated one with requested options
*
* Sec-WebSocket-Extensions: permessage-deflate; \
* server_no_context_takeover; \
* client_no_context_takeover
*/
while (more) {
if (*c && (*c != ',' && *c != '\t')) {
if (*c == ';') {
ignore = 1;
args = c + 1;
}
if (ignore || *c == ' ') {
c++;
continue;
}
ext_name[n] = *c++;
if (n < sizeof(ext_name) - 1)
n++;
continue;
}
ext_name[n] = '\0';
ignore = 0;
if (!*c)
more = 0;
else {
c++;
if (!n)
continue;
}
while (args && *args && *args == ' ')
args++;
/* check a client's extension against our support */
ext = wsi->vhost->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
* confirm he only gave it once
*/
for (m = 0; m < wsi->count_act_ext; m++)
if (wsi->active_extensions[m] == ext) {
lwsl_info("extension mentioned twice\n");
return 1; /* shenanigans */
}
/*
* ask user code if it's OK to apply it on this
* particular connection + protocol
*/
m = (wsi->protocol->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 (m) {
ext++;
continue;
}
/* apply it */
ext_count++;
/* instantiate the extension on this conn */
wsi->active_extensions[wsi->count_act_ext] = ext;
/* allow him to construct his context */
if (ext->callback(lws_get_context(wsi), ext, wsi,
LWS_EXT_CB_CONSTRUCT,
(void *)&wsi->act_ext_user[
wsi->count_act_ext],
(void *)&opts, 0)) {
lwsl_info("ext %s failed construction\n",
ext_name);
ext_count--;
ext++;
continue;
}
if (ext_count > 1)
*(*p)++ = ',';
else
LWS_CPYAPP(*p,
"\x0d\x0aSec-WebSocket-Extensions: ");
*p += lws_snprintf(*p, (end - *p), "%s", ext_name);
/*
* go through the options trying to apply the
* recognized ones
*/
lwsl_debug("ext args %s", args);
while (args && *args && *args != ',') {
while (*args == ' ')
args++;
po = opts;
while (po->name) {
lwsl_debug("'%s' '%s'\n", po->name, args);
/* only support arg-less options... */
if (po->type == EXTARG_NONE &&
!strncmp(args, po->name,
strlen(po->name))) {
oa.option_name = NULL;
oa.option_index = po - opts;
oa.start = NULL;
lwsl_debug("setting %s\n", po->name);
if (!ext->callback(
lws_get_context(wsi), ext, wsi,
LWS_EXT_CB_OPTION_SET,
wsi->act_ext_user[
wsi->count_act_ext],
&oa, (end - *p))) {
*p += lws_snprintf(*p, (end - *p), "; %s", po->name);
lwsl_debug("adding option %s\n", po->name);
}
}
po++;
}
while (*args && *args != ',' && *args != ';')
args++;
}
wsi->count_act_ext++;
lwsl_parser("count_act_ext <- %d\n",
wsi->count_act_ext);
ext++;
}
n = 0;
args = NULL;
}
return 0;
}
#endif
int
handshake_0405(struct lws_context *context, struct lws *wsi)
{
struct lws_context_per_thread *pt = &context->pt[(int)wsi->tsi];
struct lws_process_html_args args;
unsigned char hash[20];
int n, accept_len;
char *response;
char *p;
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 *)pt->serv_buf,
"%s258EAFA5-E914-47DA-95CA-C5AB0DC85B11",
lws_hdr_simple_ptr(wsi, WSI_TOKEN_KEY));
lws_SHA1(pt->serv_buf, n, hash);
accept_len = lws_b64_encode_string((char *)hash, 20,
(char *)pt->serv_buf, context->pt_serv_buf_size);
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 *)pt->serv_buf + MAX_WEBSOCKET_04_KEY_LEN + LWS_PRE;
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 *)pt->serv_buf);
p += accept_len;
/* we can only return the protocol header if:
* - one came in, and ... */
if (lws_hdr_total_length(wsi, WSI_TOKEN_PROTOCOL) &&
/* - it is not an empty string */
wsi->protocol->name &&
wsi->protocol->name[0]) {
LWS_CPYAPP(p, "\x0d\x0aSec-WebSocket-Protocol: ");
p += lws_snprintf(p, 128, "%s", wsi->protocol->name);
}
#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.
*
* Give him a limited write bugdet
*/
if (lws_extension_server_handshake(wsi, &p, 192))
goto bail;
#endif
LWS_CPYAPP(p, "\x0d\x0a");
args.p = p;
args.max_len = ((char *)pt->serv_buf + context->pt_serv_buf_size) - p;
if (user_callback_handle_rxflow(wsi->protocol->callback, wsi,
LWS_CALLBACK_ADD_HEADERS,
wsi->user_space, &args, 0))
goto bail;
p = args.p;
/* end of response packet */
LWS_CPYAPP(p, "\x0d\x0a");
if (!lws_any_extension_handled(wsi, LWS_EXT_CB_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));
#if defined(DEBUG) && ! defined(LWS_WITH_ESP8266)
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;
{
const char * uri_ptr =
lws_hdr_simple_ptr(wsi, WSI_TOKEN_GET_URI);
int uri_len = lws_hdr_total_length(wsi, WSI_TOKEN_GET_URI);
const struct lws_http_mount *hit =
lws_find_mount(wsi, uri_ptr, uri_len);
if (hit && hit->cgienv &&
wsi->protocol->callback(wsi, LWS_CALLBACK_HTTP_PMO,
wsi->user_space, (void *)hit->cgienv, 0))
return 1;
}
return 0;
bail:
/* caller will free up his parsing allocations */
return -1;
}