/*
* libwebsockets-test-server - libwebsockets test implementation
*
* Copyright (C) 2010-2015 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 "test-server.h"
/*
* This demo server shows how to use libwebsockets for one or more
* websocket protocols in the same server
*
* It defines the following websocket protocols:
*
* dumb-increment-protocol: once the socket is opened, an incrementing
* ascii string is sent down it every 50ms.
* If you send "reset\n" on the websocket, then
* the incrementing number is reset to 0.
*
* lws-mirror-protocol: copies any received packet to every connection also
* using this protocol, including the sender
*/
enum demo_protocols {
/* always first */
PROTOCOL_HTTP = 0,
PROTOCOL_DUMB_INCREMENT,
PROTOCOL_LWS_MIRROR,
/* always last */
DEMO_PROTOCOL_COUNT
};
/*
* We take a strict whitelist approach to stop ../ attacks
*/
struct serveable {
const char *urlpath;
const char *mimetype;
};
/*
* this is just an example of parsing handshake headers, you don't need this
* in your code unless you will filter allowing connections by the header
* content
*/
void
dump_handshake_info(struct lws *wsi)
{
int n = 0;
char buf[256];
const unsigned char *c;
do {
c = lws_token_to_string(n);
if (!c) {
n++;
continue;
}
if (!lws_hdr_total_length(wsi, n)) {
n++;
continue;
}
lws_hdr_copy(wsi, buf, sizeof buf, n);
fprintf(stderr, " %s = %s\n", (char *)c, buf);
n++;
} while (c);
}
const char * get_mimetype(const char *file)
{
int n = strlen(file);
if (n < 5)
return NULL;
if (!strcmp(&file[n - 4], ".ico"))
return "image/x-icon";
if (!strcmp(&file[n - 4], ".png"))
return "image/png";
if (!strcmp(&file[n - 5], ".html"))
return "text/html";
return NULL;
}
/* this protocol server (always the first one) handles HTTP,
*
* Some misc callbacks that aren't associated with a protocol also turn up only
* here on the first protocol server.
*/
int callback_http(struct lws_context *context, struct lws *wsi,
enum lws_callback_reasons reason, void *user,
void *in, size_t len)
{
struct per_session_data__http *pss =
(struct per_session_data__http *)user;
static unsigned char buffer[4096];
unsigned long amount, file_len;
char leaf_path[1024];
const char *mimetype;
char *other_headers;
unsigned char *end;
struct timeval tv;
unsigned char *p;
char buf[256];
char b64[64];
int n, m;
#ifdef EXTERNAL_POLL
struct lws_pollargs *pa = (struct lws_pollargs *)in;
#endif
switch (reason) {
case LWS_CALLBACK_HTTP:
dump_handshake_info(wsi);
if (len < 1) {
lws_return_http_status(context, wsi,
HTTP_STATUS_BAD_REQUEST, NULL);
goto try_to_reuse;
}
/* this example server has no concept of directories */
if (strchr((const char *)in + 1, '/')) {
lws_return_http_status(context, wsi,
HTTP_STATUS_FORBIDDEN, NULL);
goto try_to_reuse;
}
/* if a legal POST URL, let it continue and accept data */
if (lws_hdr_total_length(wsi, WSI_TOKEN_POST_URI))
return 0;
/* check for the "send a big file by hand" example case */
if (!strcmp((const char *)in, "/leaf.jpg")) {
if (strlen(resource_path) > sizeof(leaf_path) - 10)
return -1;
sprintf(leaf_path, "%s/leaf.jpg", resource_path);
/* well, let's demonstrate how to send the hard way */
p = buffer + LWS_SEND_BUFFER_PRE_PADDING;
end = p + sizeof(buffer) - LWS_SEND_BUFFER_PRE_PADDING;
pss->fd = lws_plat_file_open(wsi, leaf_path, &file_len,
LWS_O_RDONLY);
if (pss->fd == LWS_INVALID_FILE)
return -1;
/*
* we will send a big jpeg file, but it could be
* anything. Set the Content-Type: appropriately
* so the browser knows what to do with it.
*
* Notice we use the APIs to build the header, which
* will do the right thing for HTTP 1/1.1 and HTTP2
* depending on what connection it happens to be working
* on
*/
if (lws_add_http_header_status(context, wsi, 200, &p, end))
return 1;
if (lws_add_http_header_by_token(context, wsi,
WSI_TOKEN_HTTP_SERVER,
(unsigned char *)"libwebsockets",
13, &p, end))
return 1;
if (lws_add_http_header_by_token(context, wsi,
WSI_TOKEN_HTTP_CONTENT_TYPE,
(unsigned char *)"image/jpeg",
10, &p, end))
return 1;
if (lws_add_http_header_content_length(context, wsi,
file_len, &p,
end))
return 1;
if (lws_finalize_http_header(context, wsi, &p, end))
return 1;
/*
* send the http headers...
* this won't block since it's the first payload sent
* on the connection since it was established
* (too small for partial)
*
* Notice they are sent using LWS_WRITE_HTTP_HEADERS
* which also means you can't send body too in one step,
* this is mandated by changes in HTTP2
*/
n = lws_write(wsi, buffer + LWS_SEND_BUFFER_PRE_PADDING,
p - (buffer + LWS_SEND_BUFFER_PRE_PADDING),
LWS_WRITE_HTTP_HEADERS);
if (n < 0) {
lws_plat_file_close(wsi, pss->fd);
return -1;
}
/*
* book us a LWS_CALLBACK_HTTP_WRITEABLE callback
*/
lws_callback_on_writable(context, wsi);
break;
}
/* if not, send a file the easy way */
strcpy(buf, resource_path);
if (strcmp(in, "/")) {
if (*((const char *)in) != '/')
strcat(buf, "/");
strncat(buf, in, sizeof(buf) - strlen(resource_path));
} else /* default file to serve */
strcat(buf, "/test.html");
buf[sizeof(buf) - 1] = '\0';
/* refuse to serve files we don't understand */
mimetype = get_mimetype(buf);
if (!mimetype) {
lwsl_err("Unknown mimetype for %s\n", buf);
lws_return_http_status(context, wsi,
HTTP_STATUS_UNSUPPORTED_MEDIA_TYPE, NULL);
return -1;
}
/* demostrates how to set a cookie on / */
other_headers = NULL;
n = 0;
if (!strcmp((const char *)in, "/") &&
!lws_hdr_total_length(wsi, WSI_TOKEN_HTTP_COOKIE)) {
/* this isn't very unguessable but it'll do for us */
gettimeofday(&tv, NULL);
n = sprintf(b64, "test=LWS_%u_%u_COOKIE;Max-Age=360000",
(unsigned int)tv.tv_sec,
(unsigned int)tv.tv_usec);
p = (unsigned char *)leaf_path;
if (lws_add_http_header_by_name(context, wsi,
(unsigned char *)"set-cookie:",
(unsigned char *)b64, n, &p,
(unsigned char *)leaf_path + sizeof(leaf_path)))
return 1;
n = (char *)p - leaf_path;
other_headers = leaf_path;
}
n = lws_serve_http_file(context, wsi, buf,
mimetype, other_headers, n);
if (n < 0 || ((n > 0) && lws_http_transaction_completed(wsi)))
return -1; /* error or can't reuse connection: close the socket */
/*
* notice that the sending of the file completes asynchronously,
* we'll get a LWS_CALLBACK_HTTP_FILE_COMPLETION callback when
* it's done
*/
break;
case LWS_CALLBACK_HTTP_BODY:
strncpy(buf, in, 20);
buf[20] = '\0';
if (len < 20)
buf[len] = '\0';
lwsl_notice("LWS_CALLBACK_HTTP_BODY: %s... len %d\n",
(const char *)buf, (int)len);
break;
case LWS_CALLBACK_HTTP_BODY_COMPLETION:
lwsl_notice("LWS_CALLBACK_HTTP_BODY_COMPLETION\n");
/* the whole of the sent body arrived, close or reuse the connection */
lws_return_http_status(context, wsi,
HTTP_STATUS_OK, NULL);
goto try_to_reuse;
case LWS_CALLBACK_HTTP_FILE_COMPLETION:
goto try_to_reuse;
case LWS_CALLBACK_HTTP_WRITEABLE:
/*
* we can send more of whatever it is we were sending
*/
do {
/* we'd like the send this much */
n = sizeof(buffer) - LWS_SEND_BUFFER_PRE_PADDING;
/* but if the peer told us he wants less, we can adapt */
m = lws_get_peer_write_allowance(wsi);
/* -1 means not using a protocol that has this info */
if (m == 0)
/* right now, peer can't handle anything */
goto later;
if (m != -1 && m < n)
/* he couldn't handle that much */
n = m;
n = lws_plat_file_read(wsi, pss->fd,
&amount, buffer +
LWS_SEND_BUFFER_PRE_PADDING, n);
/* problem reading, close conn */
if (n < 0)
goto bail;
n = (int)amount;
/* sent it all, close conn */
if (n == 0)
goto flush_bail;
/*
* To support HTTP2, must take care about preamble space
*
* identification of when we send the last payload frame
* is handled by the library itself if you sent a
* content-length header
*/
m = lws_write(wsi, buffer + LWS_SEND_BUFFER_PRE_PADDING,
n, LWS_WRITE_HTTP);
if (m < 0)
/* write failed, close conn */
goto bail;
/*
* http2 won't do this
*/
if (m != n)
/* partial write, adjust */
if (lws_plat_file_seek_cur(wsi, pss->fd, m - n) ==
(unsigned long)-1)
goto bail;
if (m) /* while still active, extend timeout */
lws_set_timeout(wsi,
PENDING_TIMEOUT_HTTP_CONTENT, 5);
/* if we have indigestion, let him clear it
* before eating more */
if (lws_partial_buffered(wsi))
break;
} while (!lws_send_pipe_choked(wsi));
later:
lws_callback_on_writable(context, wsi);
break;
flush_bail:
/* true if still partial pending */
if (lws_partial_buffered(wsi)) {
lws_callback_on_writable(context, wsi);
break;
}
lws_plat_file_close(wsi, pss->fd);
goto try_to_reuse;
bail:
lws_plat_file_close(wsi, pss->fd);
return -1;
/*
* callback for confirming to continue with client IP appear in
* protocol 0 callback since no websocket protocol has been agreed
* yet. You can just ignore this if you won't filter on client IP
* since the default uhandled callback return is 0 meaning let the
* connection continue.
*/
case LWS_CALLBACK_FILTER_NETWORK_CONNECTION:
/* if we returned non-zero from here, we kill the connection */
break;
/*
* callbacks for managing the external poll() array appear in
* protocol 0 callback
*/
case LWS_CALLBACK_LOCK_POLL:
/*
* lock mutex to protect pollfd state
* called before any other POLL related callback
* if protecting wsi lifecycle change, len == 1
*/
test_server_lock(len);
break;
case LWS_CALLBACK_UNLOCK_POLL:
/*
* unlock mutex to protect pollfd state when
* called after any other POLL related callback
* if protecting wsi lifecycle change, len == 1
*/
test_server_unlock(len);
break;
#ifdef EXTERNAL_POLL
case LWS_CALLBACK_ADD_POLL_FD:
if (count_pollfds >= max_poll_elements) {
lwsl_err("LWS_CALLBACK_ADD_POLL_FD: too many sockets to track\n");
return 1;
}
fd_lookup[pa->fd] = count_pollfds;
pollfds[count_pollfds].fd = pa->fd;
pollfds[count_pollfds].events = pa->events;
pollfds[count_pollfds++].revents = 0;
break;
case LWS_CALLBACK_DEL_POLL_FD:
if (!--count_pollfds)
break;
m = fd_lookup[pa->fd];
/* have the last guy take up the vacant slot */
pollfds[m] = pollfds[count_pollfds];
fd_lookup[pollfds[count_pollfds].fd] = m;
break;
case LWS_CALLBACK_CHANGE_MODE_POLL_FD:
pollfds[fd_lookup[pa->fd]].events = pa->events;
break;
#endif
case LWS_CALLBACK_GET_THREAD_ID:
/*
* if you will call "lws_callback_on_writable"
* from a different thread, return the caller thread ID
* here so lws can use this information to work out if it
* should signal the poll() loop to exit and restart early
*/
/* return pthread_getthreadid_np(); */
break;
default:
break;
}
return 0;
/* if we're on HTTP1.1 or 2.0, will keep the idle connection alive */
try_to_reuse:
if (lws_http_transaction_completed(wsi))
return -1;
return 0;
}