2 * libwebsockets - small server side websockets and web server implementation
4 * Copyright (C) 2010-2015 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 lws_0405_frame_mask_generate(struct lws *wsi)
28 wsi->u.ws.mask[0] = 0;
29 wsi->u.ws.mask[1] = 0;
30 wsi->u.ws.mask[2] = 0;
31 wsi->u.ws.mask[3] = 0;
34 /* fetch the per-frame nonce */
36 n = lws_get_random(lws_get_context(wsi), wsi->u.ws.mask, 4);
38 lwsl_parser("Unable to read from random device %s %d\n",
39 SYSTEM_RANDOM_FILEPATH, n);
43 /* start masking from first byte of masking key buffer */
44 wsi->u.ws.mask_idx = 0;
51 LWS_VISIBLE void lwsl_hexdump(void *vbuf, size_t len)
53 unsigned char *buf = (unsigned char *)vbuf;
54 unsigned int n, m, start;
60 for (n = 0; n < len;) {
64 p += sprintf(p, "%04X: ", start);
66 for (m = 0; m < 16 && n < len; m++)
67 p += sprintf(p, "%02X ", buf[n++]);
73 for (m = 0; m < 16 && (start + m) < len; m++) {
74 if (buf[start + m] >= ' ' && buf[start + m] < 127)
75 *p++ = buf[start + m];
84 lwsl_debug("%s", line);
92 * notice this returns number of bytes consumed, or -1
95 int lws_issue_raw(struct lws *wsi, unsigned char *buf, size_t len)
97 struct lws_context *context = lws_get_context(wsi);
98 size_t real_len = len;
103 /* just ignore sends after we cleared the truncation buffer */
104 if (wsi->state == LWSS_FLUSHING_STORED_SEND_BEFORE_CLOSE &&
108 if (wsi->trunc_len && (buf < wsi->trunc_alloc ||
109 buf > (wsi->trunc_alloc + wsi->trunc_len +
110 wsi->trunc_offset))) {
111 lwsl_err("****** %x Sending new, pending truncated ...\n", wsi);
115 m = lws_ext_cb_active(wsi, LWS_EXT_CB_PACKET_TX_DO_SEND, &buf, len);
118 if (m) /* handled */ {
120 goto handle_truncated_send;
123 if (!lws_socket_is_valid(wsi->sock))
124 lwsl_warn("** error invalid sock but expected to send\n");
126 /* nope, send it on the socket directly */
127 lws_latency_pre(context, wsi);
128 n = lws_ssl_capable_write(wsi, buf, len);
129 lws_latency(context, wsi, "send lws_issue_raw", n,
130 (unsigned int)n == len);
133 case LWS_SSL_CAPABLE_ERROR:
134 /* we're going to close, let close know sends aren't possible */
135 wsi->socket_is_permanently_unusable = 1;
137 case LWS_SSL_CAPABLE_MORE_SERVICE:
138 /* nothing got sent, not fatal, retry the whole thing later */
143 handle_truncated_send:
145 * we were already handling a truncated send?
147 if (wsi->trunc_len) {
148 lwsl_info("%p partial adv %d (vs %d)\n", wsi, n, real_len);
149 wsi->trunc_offset += n;
152 if (!wsi->trunc_len) {
153 lwsl_info("***** %x partial send completed\n", wsi);
154 /* done with it, but don't free it */
156 if (wsi->state == LWSS_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 lws_callback_on_writable(wsi);
167 if ((unsigned int)n == real_len)
168 /* what we just sent went out cleanly */
172 * Newly truncated send. Buffer the remainder (it will get
173 * first priority next time the socket is writable)
175 lwsl_info("%p new partial sent %d from %d total\n", wsi, n, real_len);
178 * - if we still have a suitable malloc lying around, use it
179 * - or, if too small, reallocate it
180 * - or, if no buffer, create it
182 if (!wsi->trunc_alloc || real_len - n > wsi->trunc_alloc_len) {
183 lws_free(wsi->trunc_alloc);
185 wsi->trunc_alloc_len = real_len - n;
186 wsi->trunc_alloc = lws_malloc(real_len - n);
187 if (!wsi->trunc_alloc) {
188 lwsl_err("truncated send: unable to malloc %d\n",
193 wsi->trunc_offset = 0;
194 wsi->trunc_len = real_len - n;
195 memcpy(wsi->trunc_alloc, buf + n, real_len - n);
197 /* since something buffered, force it to get another chance to send */
198 lws_callback_on_writable(wsi);
204 * lws_write() - Apply protocol then write data to client
205 * @wsi: Websocket instance (available from user callback)
206 * @buf: The data to send. For data being sent on a websocket
207 * connection (ie, not default http), this buffer MUST have
208 * LWS_PRE bytes valid BEFORE the pointer.
209 * This is so the protocol header data can be added in-situ.
210 * @len: Count of the data bytes in the payload starting from buf
211 * @protocol: Use LWS_WRITE_HTTP to reply to an http connection, and one
212 * of LWS_WRITE_BINARY or LWS_WRITE_TEXT to send appropriate
213 * data on a websockets connection. Remember to allow the extra
214 * bytes before and after buf if LWS_WRITE_BINARY or LWS_WRITE_TEXT
217 * This function provides the way to issue data back to the client
218 * for both http and websocket protocols.
220 * In the case of sending using websocket protocol, be sure to allocate
221 * valid storage before and after buf as explained above. This scheme
222 * allows maximum efficiency of sending data and protocol in a single
223 * packet while not burdening the user code with any protocol knowledge.
225 * Return may be -1 for a fatal error needing connection close, or a
226 * positive number reflecting the amount of bytes actually sent. This
227 * can be less than the requested number of bytes due to OS memory
228 * pressure at any given time.
231 LWS_VISIBLE int lws_write(struct lws *wsi, unsigned char *buf, size_t len,
232 enum lws_write_protocol wp)
234 struct lws_context_per_thread *pt = &wsi->context->pt[(int)wsi->tsi];
235 int masked7 = (wsi->mode == LWSCM_WS_CLIENT);
236 unsigned char is_masked_bit = 0;
237 unsigned char *dropmask = NULL;
238 struct lws_tokens eff_buf;
240 size_t orig_len = len;
242 if (wsi->state == LWSS_ESTABLISHED && wsi->u.ws.tx_draining_ext) {
243 /* remove us from the list */
244 struct lws **w = &pt->tx_draining_ext_list;
245 lwsl_debug("%s: TX EXT DRAINING: Remove from list\n", __func__);
246 wsi->u.ws.tx_draining_ext = 0;
247 /* remove us from context draining ext list */
250 *w = wsi->u.ws.tx_draining_ext_list;
253 w = &((*w)->u.ws.tx_draining_ext_list);
255 wsi->u.ws.tx_draining_ext_list = NULL;
256 wp = (wsi->u.ws.tx_draining_stashed_wp & 0xc0) |
257 LWS_WRITE_CONTINUATION;
259 lwsl_ext("FORCED draining wp to 0x%02X\n", wp);
262 if (wp == LWS_WRITE_HTTP ||
263 wp == LWS_WRITE_HTTP_FINAL ||
264 wp == LWS_WRITE_HTTP_HEADERS)
267 /* if not in a state to send stuff, then just send nothing */
269 if (wsi->state != LWSS_ESTABLISHED &&
270 ((wsi->state != LWSS_RETURNED_CLOSE_ALREADY &&
271 wsi->state != LWSS_AWAITING_CLOSE_ACK) ||
272 wp != LWS_WRITE_CLOSE))
275 /* if we are continuing a frame that already had its header done */
277 if (wsi->u.ws.inside_frame) {
278 lwsl_debug("INSIDE FRAME\n");
279 goto do_more_inside_frame;
282 wsi->u.ws.clean_buffer = 1;
285 * give a chance to the extensions to modify payload
286 * the extension may decide to produce unlimited payload erratically
287 * (eg, compression extension), so we require only that if he produces
288 * something, it will be a complete fragment of the length known at
289 * the time (just the fragment length known), and if he has
290 * more we will come back next time he is writeable and allow him to
291 * produce more fragments until he's drained.
293 * This allows what is sent each time it is writeable to be limited to
294 * a size that can be sent without partial sends or blocking, allows
295 * interleaving of control frames and other connection service.
297 eff_buf.token = (char *)buf;
298 eff_buf.token_len = len;
303 case LWS_WRITE_CLOSE:
306 n = lws_ext_cb_active(wsi, LWS_EXT_CB_PAYLOAD_TX, &eff_buf, wp);
310 if (n && eff_buf.token_len) {
311 /* extension requires further draining */
312 wsi->u.ws.tx_draining_ext = 1;
313 wsi->u.ws.tx_draining_ext_list = pt->tx_draining_ext_list;
314 pt->tx_draining_ext_list = wsi;
315 /* we must come back to do more */
316 lws_callback_on_writable(wsi);
318 * keep a copy of the write type for the overall
319 * action that has provoked generation of these
320 * fragments, so the last guy can use its FIN state.
322 wsi->u.ws.tx_draining_stashed_wp = wp;
323 /* this is definitely not actually the last fragment
324 * because the extension asserted he has more coming
325 * So make sure this intermediate one doesn't go out
328 wp |= LWS_WRITE_NO_FIN;
331 if (eff_buf.token_len && wsi->u.ws.stashed_write_pending) {
332 wsi->u.ws.stashed_write_pending = 0;
333 wp = (wp &0xc0) | (int)wsi->u.ws.stashed_write_type;
338 * an extension did something we need to keep... for example, if
339 * compression extension, it has already updated its state according
340 * to this being issued
342 if ((char *)buf != eff_buf.token) {
344 * ext might eat it, but no have anything to issue yet
345 * in that case we have to follow his lead, but stash and
346 * replace the write type that was lost here the first time.
348 if (len && !eff_buf.token_len) {
349 if (!wsi->u.ws.stashed_write_pending)
350 wsi->u.ws.stashed_write_type = (char)wp & 0x3f;
351 wsi->u.ws.stashed_write_pending = 1;
355 * extension recreated it:
356 * need to buffer this if not all sent
358 wsi->u.ws.clean_buffer = 0;
361 buf = (unsigned char *)eff_buf.token;
362 len = eff_buf.token_len;
364 switch (wsi->ietf_spec_revision) {
368 dropmask = &buf[0 - pre];
369 is_masked_bit = 0x80;
374 n = LWSWSOPC_TEXT_FRAME;
376 case LWS_WRITE_BINARY:
377 n = LWSWSOPC_BINARY_FRAME;
379 case LWS_WRITE_CONTINUATION:
380 n = LWSWSOPC_CONTINUATION;
383 case LWS_WRITE_CLOSE:
393 lwsl_warn("lws_write: unknown write opc / wp\n");
397 if (!(wp & LWS_WRITE_NO_FIN))
403 buf[-pre + 1] = (unsigned char)(len | is_masked_bit);
408 buf[-pre + 1] = 126 | is_masked_bit;
409 buf[-pre + 2] = (unsigned char)(len >> 8);
410 buf[-pre + 3] = (unsigned char)len;
414 buf[-pre + 1] = 127 | is_masked_bit;
416 buf[-pre + 2] = (len >> 56) & 0x7f;
417 buf[-pre + 3] = len >> 48;
418 buf[-pre + 4] = len >> 40;
419 buf[-pre + 5] = len >> 32;
426 buf[-pre + 6] = (unsigned char)(len >> 24);
427 buf[-pre + 7] = (unsigned char)(len >> 16);
428 buf[-pre + 8] = (unsigned char)(len >> 8);
429 buf[-pre + 9] = (unsigned char)len;
435 do_more_inside_frame:
438 * Deal with masking if we are in client -> server direction and
443 if (!wsi->u.ws.inside_frame)
444 if (lws_0405_frame_mask_generate(wsi)) {
445 lwsl_err("frame mask generation failed\n");
450 * in v7, just mask the payload
452 if (dropmask) { /* never set if already inside frame */
453 for (n = 4; n < (int)len + 4; n++)
454 dropmask[n] = dropmask[n] ^ wsi->u.ws.mask[
455 (wsi->u.ws.mask_idx++) & 3];
457 /* copy the frame nonce into place */
458 memcpy(dropmask, wsi->u.ws.mask, 4);
464 case LWS_WRITE_CLOSE:
465 /* lwsl_hexdump(&buf[-pre], len); */
467 case LWS_WRITE_HTTP_FINAL:
468 case LWS_WRITE_HTTP_HEADERS:
472 if (wsi->mode == LWSCM_HTTP2_SERVING) {
473 unsigned char flags = 0;
475 n = LWS_HTTP2_FRAME_TYPE_DATA;
476 if (wp == LWS_WRITE_HTTP_HEADERS) {
477 n = LWS_HTTP2_FRAME_TYPE_HEADERS;
478 flags = LWS_HTTP2_FLAG_END_HEADERS;
479 if (wsi->u.http2.send_END_STREAM)
480 flags |= LWS_HTTP2_FLAG_END_STREAM;
483 if ((wp == LWS_WRITE_HTTP ||
484 wp == LWS_WRITE_HTTP_FINAL) &&
485 wsi->u.http.content_length) {
486 wsi->u.http.content_remain -= len;
487 lwsl_info("%s: content_remain = %lu\n", __func__,
488 wsi->u.http.content_remain);
489 if (!wsi->u.http.content_remain) {
490 lwsl_info("%s: selecting final write mode\n", __func__);
491 wp = LWS_WRITE_HTTP_FINAL;
495 if (wp == LWS_WRITE_HTTP_FINAL && wsi->u.http2.END_STREAM) {
496 lwsl_info("%s: setting END_STREAM\n", __func__);
497 flags |= LWS_HTTP2_FLAG_END_STREAM;
500 return lws_http2_frame_write(wsi, n, flags,
501 wsi->u.http2.my_stream_id, len, buf);
504 return lws_issue_raw(wsi, (unsigned char *)buf - pre, len + pre);
510 * give any active extensions a chance to munge the buffer
511 * before send. We pass in a pointer to an lws_tokens struct
512 * prepared with the default buffer and content length that's in
513 * there. Rather than rewrite the default buffer, extensions
514 * that expect to grow the buffer can adapt .token to
515 * point to their own per-connection buffer in the extension
516 * user allocation. By default with no extensions or no
517 * extension callback handling, just the normal input buffer is
518 * used then so it is efficient.
520 * callback returns 1 in case it wants to spill more buffers
522 * This takes care of holding the buffer if send is incomplete, ie,
523 * if wsi->u.ws.clean_buffer is 0 (meaning an extension meddled with
524 * the buffer). If wsi->u.ws.clean_buffer is 1, it will instead
525 * return to the user code how much OF THE USER BUFFER was consumed.
528 n = lws_issue_raw_ext_access(wsi, buf - pre, len + pre);
529 wsi->u.ws.inside_frame = 1;
533 if (n == (int)len + pre) {
534 /* everything in the buffer was handled (or rebuffered...) */
535 wsi->u.ws.inside_frame = 0;
540 * it is how many bytes of user buffer got sent... may be < orig_len
541 * in which case callback when writable has already been arranged
542 * and user code can call lws_write() again with the rest
549 LWS_VISIBLE int lws_serve_http_file_fragment(struct lws *wsi)
551 struct lws_context *context = wsi->context;
552 struct lws_context_per_thread *pt = &context->pt[(int)wsi->tsi];
553 unsigned long amount;
556 while (!lws_send_pipe_choked(wsi)) {
557 if (wsi->trunc_len) {
558 if (lws_issue_raw(wsi, wsi->trunc_alloc +
560 wsi->trunc_len) < 0) {
561 lwsl_info("%s: closing\n", __func__);
567 if (wsi->u.http.filepos == wsi->u.http.filelen)
570 if (lws_plat_file_read(wsi, wsi->u.http.fd, &amount,
572 LWS_MAX_SOCKET_IO_BUF) < 0)
573 return -1; /* caller will close */
577 lws_set_timeout(wsi, PENDING_TIMEOUT_HTTP_CONTENT,
579 wsi->u.http.filepos += n;
580 m = lws_write(wsi, pt->serv_buf, n,
581 wsi->u.http.filepos == wsi->u.http.filelen ?
582 LWS_WRITE_HTTP_FINAL : LWS_WRITE_HTTP);
587 /* adjust for what was not sent */
588 if (lws_plat_file_seek_cur(wsi, wsi->u.http.fd,
594 if (!wsi->trunc_len && wsi->u.http.filepos == wsi->u.http.filelen) {
595 wsi->state = LWSS_HTTP;
597 /* we might be in keepalive, so close it off here */
598 lws_plat_file_close(wsi, wsi->u.http.fd);
599 wsi->u.http.fd = LWS_INVALID_FILE;
601 if (wsi->protocol->callback)
602 /* ignore callback returned value */
603 if (user_callback_handle_rxflow(
604 wsi->protocol->callback, wsi,
605 LWS_CALLBACK_HTTP_FILE_COMPLETION,
606 wsi->user_space, NULL, 0) < 0)
608 return 1; /* >0 indicates completed */
612 lwsl_info("choked before able to send whole file (post)\n");
613 lws_callback_on_writable(wsi);
615 return 0; /* indicates further processing must be done */
620 lws_ssl_capable_read_no_ssl(struct lws *wsi, unsigned char *buf, int len)
624 n = recv(wsi->sock, (char *)buf, len, 0);
628 if (LWS_ERRNO == LWS_EAGAIN ||
629 LWS_ERRNO == LWS_EWOULDBLOCK ||
630 LWS_ERRNO == LWS_EINTR)
631 return LWS_SSL_CAPABLE_MORE_SERVICE;
633 lwsl_warn("error on reading from skt\n");
634 return LWS_SSL_CAPABLE_ERROR;
638 lws_ssl_capable_write_no_ssl(struct lws *wsi, unsigned char *buf, int len)
643 n = send(wsi->sock, (char *)buf, len, MSG_NOSIGNAL);
644 // lwsl_info("%s: sent len %d result %d", __func__, len, n);
648 if (LWS_ERRNO == LWS_EAGAIN ||
649 LWS_ERRNO == LWS_EWOULDBLOCK ||
650 LWS_ERRNO == LWS_EINTR) {
651 if (LWS_ERRNO == LWS_EWOULDBLOCK)
652 lws_set_blocking_send(wsi);
654 return LWS_SSL_CAPABLE_MORE_SERVICE;
664 lwsl_debug("ERROR writing len %d to skt fd %d err %d / errno %d\n", len, wsi->sock, n, LWS_ERRNO);
665 return LWS_SSL_CAPABLE_ERROR;
669 lws_ssl_pending_no_ssl(struct lws *wsi)