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 lws_0405_frame_mask_generate(struct lws *wsi)
29 /* fetch the per-frame nonce */
31 n = lws_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 lws *wsi, unsigned char *buf, size_t len)
95 struct lws_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 + wsi->truncated_send_len +
109 wsi->truncated_send_offset))) {
110 lwsl_err("****** %x Sending new, pending truncated ...\n", wsi);
114 m = lws_ext_callback_for_each_active(wsi,
115 LWS_EXT_CALLBACK_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");
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, (unsigned int)n == len);
134 case LWS_SSL_CAPABLE_ERROR:
135 lwsl_err("%s: wsi %p: LWS_SSL_CAPABLE_ERROR\n", __func__, (void *)wsi);
136 /* we're going to close, let close know sends aren't possible */
137 wsi->socket_is_permanently_unusable = 1;
139 case LWS_SSL_CAPABLE_MORE_SERVICE:
140 /* nothing got sent, not fatal, retry the whole thing later */
145 handle_truncated_send:
147 * we were already handling a truncated send?
149 if (wsi->truncated_send_len) {
150 lwsl_info("***** %x partial send moved on by %d (vs %d)\n",
152 wsi->truncated_send_offset += n;
153 wsi->truncated_send_len -= n;
155 if (!wsi->truncated_send_len) {
156 lwsl_info("***** %x partial send completed\n", wsi);
157 /* done with it, but don't free it */
159 if (wsi->state == WSI_STATE_FLUSHING_STORED_SEND_BEFORE_CLOSE) {
160 lwsl_info("***** %x signalling to close now\n", wsi);
161 return -1; /* retry closing now */
164 /* always callback on writeable */
165 lws_callback_on_writable(
166 wsi->protocol->owning_server, wsi);
171 if ((unsigned int)n == real_len)
172 /* what we just sent went out cleanly */
175 if (n && wsi->u.ws.clean_buffer)
177 * This buffer unaffected by extension rewriting.
178 * It means the user code is expected to deal with
179 * partial sends. (lws knows the header was already
180 * sent, so on next send will just resume sending
186 * Newly truncated send. Buffer the remainder (it will get
187 * first priority next time the socket is writable)
189 lwsl_info("***** %x new partial sent %d from %d total\n",
193 * - if we still have a suitable malloc lying around, use it
194 * - or, if too small, reallocate it
195 * - or, if no buffer, create it
197 if (!wsi->truncated_send_malloc ||
198 real_len - n > wsi->truncated_send_allocation) {
199 lws_free(wsi->truncated_send_malloc);
201 wsi->truncated_send_allocation = real_len - n;
202 wsi->truncated_send_malloc = lws_malloc(real_len - n);
203 if (!wsi->truncated_send_malloc) {
204 lwsl_err("truncated send: unable to malloc %d\n",
209 wsi->truncated_send_offset = 0;
210 wsi->truncated_send_len = real_len - n;
211 memcpy(wsi->truncated_send_malloc, buf + n, real_len - n);
213 /* since something buffered, force it to get another chance to send */
214 lws_callback_on_writable(wsi->protocol->owning_server, wsi);
220 * lws_write() - Apply protocol then write data to client
221 * @wsi: Websocket instance (available from user callback)
222 * @buf: The data to send. For data being sent on a websocket
223 * connection (ie, not default http), this buffer MUST have
224 * LWS_SEND_BUFFER_PRE_PADDING bytes valid BEFORE the pointer
225 * and an additional LWS_SEND_BUFFER_POST_PADDING bytes valid
226 * in the buffer after (buf + len). This is so the protocol
227 * header and trailer data can be added in-situ.
228 * @len: Count of the data bytes in the payload starting from buf
229 * @protocol: Use LWS_WRITE_HTTP to reply to an http connection, and one
230 * of LWS_WRITE_BINARY or LWS_WRITE_TEXT to send appropriate
231 * data on a websockets connection. Remember to allow the extra
232 * bytes before and after buf if LWS_WRITE_BINARY or LWS_WRITE_TEXT
235 * This function provides the way to issue data back to the client
236 * for both http and websocket protocols.
238 * In the case of sending using websocket protocol, be sure to allocate
239 * valid storage before and after buf as explained above. This scheme
240 * allows maximum efficiency of sending data and protocol in a single
241 * packet while not burdening the user code with any protocol knowledge.
243 * Return may be -1 for a fatal error needing connection close, or a
244 * positive number reflecting the amount of bytes actually sent. This
245 * can be less than the requested number of bytes due to OS memory
246 * pressure at any given time.
249 LWS_VISIBLE int lws_write(struct lws *wsi, unsigned char *buf,
250 size_t len, enum lws_write_protocol protocol)
255 int masked7 = wsi->mode == LWS_CONNMODE_WS_CLIENT;
256 unsigned char *dropmask = NULL;
257 unsigned char is_masked_bit = 0;
258 size_t orig_len = len;
259 struct lws_tokens eff_buf;
261 if (len == 0 && protocol != LWS_WRITE_CLOSE &&
262 protocol != LWS_WRITE_PING && protocol != LWS_WRITE_PONG) {
263 lwsl_warn("zero length lws_write attempt\n");
267 if (protocol == LWS_WRITE_HTTP ||
268 protocol == LWS_WRITE_HTTP_FINAL ||
269 protocol == LWS_WRITE_HTTP_HEADERS)
272 /* websocket protocol, either binary or text */
274 if (wsi->state != WSI_STATE_ESTABLISHED &&
275 !(wsi->state == WSI_STATE_RETURNED_CLOSE_ALREADY &&
276 protocol == LWS_WRITE_CLOSE))
279 /* if we are continuing a frame that already had its header done */
281 if (wsi->u.ws.inside_frame)
282 goto do_more_inside_frame;
284 wsi->u.ws.clean_buffer = 1;
287 * give a chance to the extensions to modify payload
288 * pre-TX mangling is not allowed to truncate
290 eff_buf.token = (char *)buf;
291 eff_buf.token_len = len;
296 case LWS_WRITE_CLOSE:
299 if (lws_ext_callback_for_each_active(wsi,
300 LWS_EXT_CALLBACK_PAYLOAD_TX, &eff_buf, 0) < 0)
305 * an extension did something we need to keep... for example, if
306 * compression extension, it has already updated its state according
307 * to this being issued
309 if ((char *)buf != eff_buf.token)
311 * extension recreated it:
312 * need to buffer this if not all sent
314 wsi->u.ws.clean_buffer = 0;
316 buf = (unsigned char *)eff_buf.token;
317 len = eff_buf.token_len;
319 switch (wsi->ietf_spec_revision) {
324 dropmask = &buf[0 - pre];
325 is_masked_bit = 0x80;
328 switch (protocol & 0xf) {
330 n = LWS_WS_OPCODE_07__TEXT_FRAME;
332 case LWS_WRITE_BINARY:
333 n = LWS_WS_OPCODE_07__BINARY_FRAME;
335 case LWS_WRITE_CONTINUATION:
336 n = LWS_WS_OPCODE_07__CONTINUATION;
339 case LWS_WRITE_CLOSE:
340 n = LWS_WS_OPCODE_07__CLOSE;
343 * 06+ has a 2-byte status code in network order
344 * we can do this because we demand post-buf
347 if (wsi->u.ws.close_reason) {
348 /* reason codes count as data bytes */
350 buf[0] = wsi->u.ws.close_reason >> 8;
351 buf[1] = wsi->u.ws.close_reason;
356 n = LWS_WS_OPCODE_07__PING;
359 n = LWS_WS_OPCODE_07__PONG;
362 lwsl_warn("lws_write: unknown write opc / protocol\n");
366 if (!(protocol & LWS_WRITE_NO_FIN))
372 buf[-pre + 1] = len | is_masked_bit;
377 buf[-pre + 1] = 126 | is_masked_bit;
378 buf[-pre + 2] = len >> 8;
383 buf[-pre + 1] = 127 | is_masked_bit;
385 buf[-pre + 2] = (len >> 56) & 0x7f;
386 buf[-pre + 3] = len >> 48;
387 buf[-pre + 4] = len >> 40;
388 buf[-pre + 5] = len >> 32;
395 buf[-pre + 6] = len >> 24;
396 buf[-pre + 7] = len >> 16;
397 buf[-pre + 8] = len >> 8;
404 do_more_inside_frame:
407 * Deal with masking if we are in client -> server direction and
408 * the protocol demands it
411 if (wsi->mode == LWS_CONNMODE_WS_CLIENT) {
413 if (!wsi->u.ws.inside_frame)
414 if (lws_0405_frame_mask_generate(wsi)) {
415 lwsl_err("frame mask generation failed\n");
420 * in v7, just mask the payload
422 if (dropmask) { /* never set if already inside frame */
423 for (n = 4; n < (int)len + 4; n++)
424 dropmask[n] = dropmask[n] ^
425 wsi->u.ws.frame_masking_nonce_04[
426 (wsi->u.ws.frame_mask_index++) & 3];
428 /* copy the frame nonce into place */
429 memcpy(dropmask, wsi->u.ws.frame_masking_nonce_04, 4);
435 case LWS_WRITE_CLOSE:
436 /* lwsl_hexdump(&buf[-pre], len + post); */
438 case LWS_WRITE_HTTP_FINAL:
439 case LWS_WRITE_HTTP_HEADERS:
443 if (wsi->mode == LWS_CONNMODE_HTTP2_SERVING) {
444 unsigned char flags = 0;
446 n = LWS_HTTP2_FRAME_TYPE_DATA;
447 if (protocol == LWS_WRITE_HTTP_HEADERS) {
448 n = LWS_HTTP2_FRAME_TYPE_HEADERS;
449 flags = LWS_HTTP2_FLAG_END_HEADERS;
450 if (wsi->u.http2.send_END_STREAM)
451 flags |= LWS_HTTP2_FLAG_END_STREAM;
454 if ((protocol == LWS_WRITE_HTTP || protocol == LWS_WRITE_HTTP_FINAL) && wsi->u.http.content_length) {
455 wsi->u.http.content_remain -= len;
456 lwsl_info("%s: content_remain = %lu\n", __func__, wsi->u.http.content_remain);
457 if (!wsi->u.http.content_remain) {
458 lwsl_info("%s: selecting final write mode\n", __func__);
459 protocol = LWS_WRITE_HTTP_FINAL;
463 if (protocol == LWS_WRITE_HTTP_FINAL && wsi->u.http2.END_STREAM) {
464 lwsl_info("%s: setting END_STREAM\n", __func__);
465 flags |= LWS_HTTP2_FLAG_END_STREAM;
468 return lws_http2_frame_write(wsi, n, flags, wsi->u.http2.my_stream_id, len, buf);
471 return lws_issue_raw(wsi, (unsigned char *)buf - pre,
477 wsi->u.ws.inside_frame = 1;
480 * give any active extensions a chance to munge the buffer
481 * before send. We pass in a pointer to an lws_tokens struct
482 * prepared with the default buffer and content length that's in
483 * there. Rather than rewrite the default buffer, extensions
484 * that expect to grow the buffer can adapt .token to
485 * point to their own per-connection buffer in the extension
486 * user allocation. By default with no extensions or no
487 * extension callback handling, just the normal input buffer is
488 * used then so it is efficient.
490 * callback returns 1 in case it wants to spill more buffers
492 * This takes care of holding the buffer if send is incomplete, ie,
493 * if wsi->u.ws.clean_buffer is 0 (meaning an extension meddled with
494 * the buffer). If wsi->u.ws.clean_buffer is 1, it will instead
495 * return to the user code how much OF THE USER BUFFER was consumed.
498 n = lws_issue_raw_ext_access(wsi, buf - pre, len + pre + post);
502 if (n == (int)len + pre + post) {
503 /* everything in the buffer was handled (or rebuffered...) */
504 wsi->u.ws.inside_frame = 0;
509 * it is how many bytes of user buffer got sent... may be < orig_len
510 * in which case callback when writable has already been arranged
511 * and user code can call lws_write() again with the rest
515 return n - (pre + post);
518 LWS_VISIBLE int lws_serve_http_file_fragment(struct lws_context *context,
524 while (!lws_send_pipe_choked(wsi)) {
526 if (wsi->truncated_send_len) {
527 if (lws_issue_raw(wsi, wsi->truncated_send_malloc +
528 wsi->truncated_send_offset,
529 wsi->truncated_send_len) < 0) {
530 lwsl_info("closing from lws_serve_http_file_fragment\n");
536 if (wsi->u.http.filepos == wsi->u.http.filelen)
539 compatible_file_read(n, wsi->u.http.fd, context->service_buffer,
540 sizeof(context->service_buffer));
542 return -1; /* caller will close */
544 lws_set_timeout(wsi, PENDING_TIMEOUT_HTTP_CONTENT, AWAITING_TIMEOUT);
545 wsi->u.http.filepos += n;
546 m = lws_write(wsi, context->service_buffer, n,
547 wsi->u.http.filepos == wsi->u.http.filelen ? LWS_WRITE_HTTP_FINAL : LWS_WRITE_HTTP);
552 /* adjust for what was not sent */
553 if (compatible_file_seek_cur(wsi->u.http.fd, m - n) < 0)
557 if (!wsi->truncated_send_len &&
558 wsi->u.http.filepos == wsi->u.http.filelen) {
559 wsi->state = WSI_STATE_HTTP;
561 /* we might be in keepalive, so close it off here */
562 compatible_file_close(wsi->u.http.fd);
563 wsi->u.http.fd = LWS_INVALID_FILE;
565 if (wsi->protocol->callback)
566 /* ignore callback returned value */
567 user_callback_handle_rxflow(
568 wsi->protocol->callback, context, wsi,
569 LWS_CALLBACK_HTTP_FILE_COMPLETION,
570 wsi->user_space, NULL, 0);
571 return 1; /* >0 indicates completed */
575 lwsl_info("choked before able to send whole file (post)\n");
576 lws_callback_on_writable(context, wsi);
578 return 0; /* indicates further processing must be done */
583 lws_ssl_capable_read_no_ssl(struct lws_context *context,
584 struct lws *wsi, unsigned char *buf, int len)
590 n = recv(wsi->sock, (char *)buf, len, 0);
594 if (LWS_ERRNO == LWS_EAGAIN ||
595 LWS_ERRNO == LWS_EWOULDBLOCK ||
596 LWS_ERRNO == LWS_EINTR)
597 return LWS_SSL_CAPABLE_MORE_SERVICE;
599 lwsl_warn("error on reading from skt\n");
600 return LWS_SSL_CAPABLE_ERROR;
604 lws_ssl_capable_write_no_ssl(struct lws *wsi, unsigned char *buf, int len)
609 n = send(wsi->sock, (char *)buf, len, MSG_NOSIGNAL);
613 if (LWS_ERRNO == LWS_EAGAIN ||
614 LWS_ERRNO == LWS_EWOULDBLOCK ||
615 LWS_ERRNO == LWS_EINTR) {
616 if (LWS_ERRNO == LWS_EWOULDBLOCK)
617 lws_set_blocking_send(wsi);
619 return LWS_SSL_CAPABLE_MORE_SERVICE;
629 lwsl_debug("ERROR writing len %d to skt %d\n", len, n);
630 return LWS_SSL_CAPABLE_ERROR;
634 lws_ssl_pending_no_ssl(struct lws *wsi)