2 * libwebsockets - small server side websockets and web server implementation
4 * Copyright (C) 2010-2014 Andy Green <andy@warmcat.com>
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation:
9 * version 2.1 of the License.
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
22 #include "private-libwebsockets.h"
25 libwebsocket_0405_frame_mask_generate(struct libwebsocket *wsi)
29 /* fetch the per-frame nonce */
31 n = libwebsockets_get_random(wsi->protocol->owning_server,
32 wsi->u.ws.frame_masking_nonce_04, 4);
34 lwsl_parser("Unable to read from random device %s %d\n",
35 SYSTEM_RANDOM_FILEPATH, n);
39 /* start masking from first byte of masking key buffer */
40 wsi->u.ws.frame_mask_index = 0;
47 LWS_VISIBLE void lwsl_hexdump(void *vbuf, size_t len)
52 unsigned char *buf = (unsigned char *)vbuf;
58 for (n = 0; n < len;) {
62 p += sprintf(p, "%04X: ", start);
64 for (m = 0; m < 16 && n < len; m++)
65 p += sprintf(p, "%02X ", buf[n++]);
71 for (m = 0; m < 16 && (start + m) < len; m++) {
72 if (buf[start + m] >= ' ' && buf[start + m] < 127)
73 *p++ = buf[start + m];
82 lwsl_debug("%s", line);
90 * notice this returns number of bytes consumed, or -1
93 int lws_issue_raw(struct libwebsocket *wsi, unsigned char *buf, size_t len)
95 struct libwebsocket_context *context = wsi->protocol->owning_server;
97 size_t real_len = len;
102 /* just ignore sends after we cleared the truncation buffer */
103 if (wsi->state == WSI_STATE_FLUSHING_STORED_SEND_BEFORE_CLOSE &&
104 !wsi->truncated_send_len)
107 if (wsi->truncated_send_len && (buf < wsi->truncated_send_malloc ||
108 buf > (wsi->truncated_send_malloc +
109 wsi->truncated_send_len +
110 wsi->truncated_send_offset))) {
111 lwsl_err("****** %x Sending new, pending truncated ...\n", wsi);
115 m = lws_ext_callback_for_each_active(wsi,
116 LWS_EXT_CALLBACK_PACKET_TX_DO_SEND, &buf, len);
119 if (m) /* handled */ {
121 goto handle_truncated_send;
124 lwsl_warn("** error invalid sock but expected to send\n");
127 * nope, send it on the socket directly
129 lws_latency_pre(context, wsi);
130 n = lws_ssl_capable_write(wsi, buf, len);
131 lws_latency(context, wsi, "send lws_issue_raw", n, n == len);
134 case LWS_SSL_CAPABLE_ERROR:
136 case LWS_SSL_CAPABLE_MORE_SERVICE:
137 /* nothing got sent, not fatal, retry the whole thing later */
142 handle_truncated_send:
144 * we were already handling a truncated send?
146 if (wsi->truncated_send_len) {
147 lwsl_info("***** %x partial send moved on by %d (vs %d)\n",
149 wsi->truncated_send_offset += n;
150 wsi->truncated_send_len -= n;
152 if (!wsi->truncated_send_len) {
153 lwsl_info("***** %x partial send completed\n", wsi);
154 /* done with it, but don't free it */
156 if (wsi->state == WSI_STATE_FLUSHING_STORED_SEND_BEFORE_CLOSE) {
157 lwsl_info("***** %x signalling to close now\n", wsi);
158 return -1; /* retry closing now */
161 /* always callback on writeable */
162 libwebsocket_callback_on_writable(
163 wsi->protocol->owning_server, wsi);
169 /* what we just sent went out cleanly */
172 if (n && wsi->u.ws.clean_buffer)
174 * This buffer unaffected by extension rewriting.
175 * It means the user code is expected to deal with
176 * partial sends. (lws knows the header was already
177 * sent, so on next send will just resume sending
183 * Newly truncated send. Buffer the remainder (it will get
184 * first priority next time the socket is writable)
186 lwsl_info("***** %x new partial sent %d from %d total\n",
190 * - if we still have a suitable malloc lying around, use it
191 * - or, if too small, reallocate it
192 * - or, if no buffer, create it
194 if (!wsi->truncated_send_malloc ||
195 real_len - n > wsi->truncated_send_allocation) {
196 if (wsi->truncated_send_malloc)
197 free(wsi->truncated_send_malloc);
199 wsi->truncated_send_allocation = real_len - n;
200 wsi->truncated_send_malloc = malloc(real_len - n);
201 if (!wsi->truncated_send_malloc) {
202 lwsl_err("truncated send: unable to malloc %d\n",
207 wsi->truncated_send_offset = 0;
208 wsi->truncated_send_len = real_len - n;
209 memcpy(wsi->truncated_send_malloc, buf + n, real_len - n);
211 /* since something buffered, force it to get another chance to send */
212 libwebsocket_callback_on_writable(wsi->protocol->owning_server, wsi);
218 * libwebsocket_write() - Apply protocol then write data to client
219 * @wsi: Websocket instance (available from user callback)
220 * @buf: The data to send. For data being sent on a websocket
221 * connection (ie, not default http), this buffer MUST have
222 * LWS_SEND_BUFFER_PRE_PADDING bytes valid BEFORE the pointer
223 * and an additional LWS_SEND_BUFFER_POST_PADDING bytes valid
224 * in the buffer after (buf + len). This is so the protocol
225 * header and trailer data can be added in-situ.
226 * @len: Count of the data bytes in the payload starting from buf
227 * @protocol: Use LWS_WRITE_HTTP to reply to an http connection, and one
228 * of LWS_WRITE_BINARY or LWS_WRITE_TEXT to send appropriate
229 * data on a websockets connection. Remember to allow the extra
230 * bytes before and after buf if LWS_WRITE_BINARY or LWS_WRITE_TEXT
233 * This function provides the way to issue data back to the client
234 * for both http and websocket protocols.
236 * In the case of sending using websocket protocol, be sure to allocate
237 * valid storage before and after buf as explained above. This scheme
238 * allows maximum efficiency of sending data and protocol in a single
239 * packet while not burdening the user code with any protocol knowledge.
241 * Return may be -1 for a fatal error needing connection close, or a
242 * positive number reflecting the amount of bytes actually sent. This
243 * can be less than the requested number of bytes due to OS memory
244 * pressure at any given time.
247 LWS_VISIBLE int libwebsocket_write(struct libwebsocket *wsi, unsigned char *buf,
248 size_t len, enum libwebsocket_write_protocol protocol)
253 int masked7 = wsi->mode == LWS_CONNMODE_WS_CLIENT;
254 unsigned char *dropmask = NULL;
255 unsigned char is_masked_bit = 0;
256 size_t orig_len = len;
257 struct lws_tokens eff_buf;
259 if (len == 0 && protocol != LWS_WRITE_CLOSE &&
260 protocol != LWS_WRITE_PING && protocol != LWS_WRITE_PONG) {
261 lwsl_warn("zero length libwebsocket_write attempt\n");
265 if (protocol == LWS_WRITE_HTTP)
268 /* websocket protocol, either binary or text */
270 if (wsi->state != WSI_STATE_ESTABLISHED)
273 /* if we are continuing a frame that already had its header done */
275 if (wsi->u.ws.inside_frame)
276 goto do_more_inside_frame;
278 wsi->u.ws.clean_buffer = 1;
281 * give a chance to the extensions to modify payload
282 * pre-TX mangling is not allowed to truncate
284 eff_buf.token = (char *)buf;
285 eff_buf.token_len = len;
290 case LWS_WRITE_CLOSE:
293 if (lws_ext_callback_for_each_active(wsi,
294 LWS_EXT_CALLBACK_PAYLOAD_TX, &eff_buf, 0) < 0)
299 * an extension did something we need to keep... for example, if
300 * compression extension, it has already updated its state according
301 * to this being issued
303 if ((char *)buf != eff_buf.token)
305 * extension recreated it:
306 * need to buffer this if not all sent
308 wsi->u.ws.clean_buffer = 0;
310 buf = (unsigned char *)eff_buf.token;
311 len = eff_buf.token_len;
313 switch (wsi->ietf_spec_revision) {
318 dropmask = &buf[0 - pre];
319 is_masked_bit = 0x80;
322 switch (protocol & 0xf) {
324 n = LWS_WS_OPCODE_07__TEXT_FRAME;
326 case LWS_WRITE_BINARY:
327 n = LWS_WS_OPCODE_07__BINARY_FRAME;
329 case LWS_WRITE_CONTINUATION:
330 n = LWS_WS_OPCODE_07__CONTINUATION;
333 case LWS_WRITE_CLOSE:
334 n = LWS_WS_OPCODE_07__CLOSE;
337 * 06+ has a 2-byte status code in network order
338 * we can do this because we demand post-buf
341 if (wsi->u.ws.close_reason) {
342 /* reason codes count as data bytes */
344 buf[0] = wsi->u.ws.close_reason >> 8;
345 buf[1] = wsi->u.ws.close_reason;
350 n = LWS_WS_OPCODE_07__PING;
353 n = LWS_WS_OPCODE_07__PONG;
356 lwsl_warn("lws_write: unknown write opc / protocol\n");
360 if (!(protocol & LWS_WRITE_NO_FIN))
366 buf[-pre + 1] = len | is_masked_bit;
371 buf[-pre + 1] = 126 | is_masked_bit;
372 buf[-pre + 2] = len >> 8;
377 buf[-pre + 1] = 127 | is_masked_bit;
379 buf[-pre + 2] = (len >> 56) & 0x7f;
380 buf[-pre + 3] = len >> 48;
381 buf[-pre + 4] = len >> 40;
382 buf[-pre + 5] = len >> 32;
389 buf[-pre + 6] = len >> 24;
390 buf[-pre + 7] = len >> 16;
391 buf[-pre + 8] = len >> 8;
398 do_more_inside_frame:
401 * Deal with masking if we are in client -> server direction and
402 * the protocol demands it
405 if (wsi->mode == LWS_CONNMODE_WS_CLIENT) {
407 if (!wsi->u.ws.inside_frame)
408 if (libwebsocket_0405_frame_mask_generate(wsi)) {
409 lwsl_err("frame mask generation failed\n");
414 * in v7, just mask the payload
416 if (dropmask) { /* never set if already inside frame */
417 for (n = 4; n < (int)len + 4; n++)
418 dropmask[n] = dropmask[n] ^
419 wsi->u.ws.frame_masking_nonce_04[
420 (wsi->u.ws.frame_mask_index++) & 3];
422 /* copy the frame nonce into place */
423 memcpy(dropmask, wsi->u.ws.frame_masking_nonce_04, 4);
429 case LWS_WRITE_CLOSE:
430 /* lwsl_hexdump(&buf[-pre], len + post); */
434 return lws_issue_raw(wsi, (unsigned char *)buf - pre,
440 wsi->u.ws.inside_frame = 1;
443 * give any active extensions a chance to munge the buffer
444 * before send. We pass in a pointer to an lws_tokens struct
445 * prepared with the default buffer and content length that's in
446 * there. Rather than rewrite the default buffer, extensions
447 * that expect to grow the buffer can adapt .token to
448 * point to their own per-connection buffer in the extension
449 * user allocation. By default with no extensions or no
450 * extension callback handling, just the normal input buffer is
451 * used then so it is efficient.
453 * callback returns 1 in case it wants to spill more buffers
455 * This takes care of holding the buffer if send is incomplete, ie,
456 * if wsi->u.ws.clean_buffer is 0 (meaning an extension meddled with
457 * the buffer). If wsi->u.ws.clean_buffer is 1, it will instead
458 * return to the user code how much OF THE USER BUFFER was consumed.
461 n = lws_issue_raw_ext_access(wsi, buf - pre, len + pre + post);
465 if (n == len + pre + post) {
466 /* everything in the buffer was handled (or rebuffered...) */
467 wsi->u.ws.inside_frame = 0;
472 * it is how many bytes of user buffer got sent... may be < orig_len
473 * in which case callback when writable has already been arranged
474 * and user code can call libwebsocket_write() again with the rest
478 return n - (pre + post);
481 LWS_VISIBLE int libwebsockets_serve_http_file_fragment(
482 struct libwebsocket_context *context, struct libwebsocket *wsi)
487 while (!lws_send_pipe_choked(wsi)) {
489 if (wsi->truncated_send_len) {
490 if (lws_issue_raw(wsi, wsi->truncated_send_malloc +
491 wsi->truncated_send_offset,
492 wsi->truncated_send_len) < 0) {
493 lwsl_info("closing from libwebsockets_serve_http_file_fragment\n");
499 if (wsi->u.http.filepos == wsi->u.http.filelen)
502 compatible_file_read(n, wsi->u.http.fd, context->service_buffer,
503 sizeof(context->service_buffer));
505 return -1; /* caller will close */
507 m = libwebsocket_write(wsi, context->service_buffer, n,
512 wsi->u.http.filepos += m;
514 /* adjust for what was not sent */
515 compatible_file_seek_cur(wsi->u.http.fd, m - n);
518 if (!wsi->truncated_send_len &&
519 wsi->u.http.filepos == wsi->u.http.filelen) {
520 wsi->state = WSI_STATE_HTTP;
522 if (wsi->protocol->callback)
523 /* ignore callback returned value */
524 user_callback_handle_rxflow(
525 wsi->protocol->callback, context, wsi,
526 LWS_CALLBACK_HTTP_FILE_COMPLETION,
527 wsi->user_space, NULL, 0);
528 return 1; /* >0 indicates completed */
532 lwsl_info("choked before able to send whole file (post)\n");
533 libwebsocket_callback_on_writable(context, wsi);
535 return 0; /* indicates further processing must be done */
539 lws_ssl_capable_read_no_ssl(struct libwebsocket *wsi, unsigned char *buf, int len)
543 n = recv(wsi->sock, buf, len, 0);
547 lwsl_warn("error on reading from skt\n");
548 return LWS_SSL_CAPABLE_ERROR;
552 lws_ssl_capable_write_no_ssl(struct libwebsocket *wsi, unsigned char *buf, int len)
556 n = send(wsi->sock, buf, len, 0);
560 if (LWS_ERRNO == LWS_EAGAIN ||
561 LWS_ERRNO == LWS_EWOULDBLOCK ||
562 LWS_ERRNO == LWS_EINTR) {
563 if (LWS_ERRNO == LWS_EWOULDBLOCK)
564 lws_set_blocking_send(wsi);
566 return LWS_SSL_CAPABLE_MORE_SERVICE;
568 lwsl_debug("ERROR writing len %d to skt %d\n", len, n);
569 return LWS_SSL_CAPABLE_ERROR;