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:
135 /* we're going to close, let close know sends aren't possible */
136 wsi->socket_is_permanently_unusable = 1;
138 case LWS_SSL_CAPABLE_MORE_SERVICE:
139 /* nothing got sent, not fatal, retry the whole thing later */
144 handle_truncated_send:
146 * we were already handling a truncated send?
148 if (wsi->truncated_send_len) {
149 lwsl_info("***** %x partial send moved on by %d (vs %d)\n",
151 wsi->truncated_send_offset += n;
152 wsi->truncated_send_len -= n;
154 if (!wsi->truncated_send_len) {
155 lwsl_info("***** %x partial send completed\n", wsi);
156 /* done with it, but don't free it */
158 if (wsi->state == WSI_STATE_FLUSHING_STORED_SEND_BEFORE_CLOSE) {
159 lwsl_info("***** %x signalling to close now\n", wsi);
160 return -1; /* retry closing now */
163 /* always callback on writeable */
164 libwebsocket_callback_on_writable(
165 wsi->protocol->owning_server, wsi);
171 /* what we just sent went out cleanly */
174 if (n && wsi->u.ws.clean_buffer)
176 * This buffer unaffected by extension rewriting.
177 * It means the user code is expected to deal with
178 * partial sends. (lws knows the header was already
179 * sent, so on next send will just resume sending
185 * Newly truncated send. Buffer the remainder (it will get
186 * first priority next time the socket is writable)
188 lwsl_info("***** %x new partial sent %d from %d total\n",
192 * - if we still have a suitable malloc lying around, use it
193 * - or, if too small, reallocate it
194 * - or, if no buffer, create it
196 if (!wsi->truncated_send_malloc ||
197 real_len - n > wsi->truncated_send_allocation) {
198 lws_free(wsi->truncated_send_malloc);
200 wsi->truncated_send_allocation = real_len - n;
201 wsi->truncated_send_malloc = lws_malloc(real_len - n);
202 if (!wsi->truncated_send_malloc) {
203 lwsl_err("truncated send: unable to malloc %d\n",
208 wsi->truncated_send_offset = 0;
209 wsi->truncated_send_len = real_len - n;
210 memcpy(wsi->truncated_send_malloc, buf + n, real_len - n);
212 /* since something buffered, force it to get another chance to send */
213 libwebsocket_callback_on_writable(wsi->protocol->owning_server, wsi);
219 * libwebsocket_write() - Apply protocol then write data to client
220 * @wsi: Websocket instance (available from user callback)
221 * @buf: The data to send. For data being sent on a websocket
222 * connection (ie, not default http), this buffer MUST have
223 * LWS_SEND_BUFFER_PRE_PADDING bytes valid BEFORE the pointer
224 * and an additional LWS_SEND_BUFFER_POST_PADDING bytes valid
225 * in the buffer after (buf + len). This is so the protocol
226 * header and trailer data can be added in-situ.
227 * @len: Count of the data bytes in the payload starting from buf
228 * @protocol: Use LWS_WRITE_HTTP to reply to an http connection, and one
229 * of LWS_WRITE_BINARY or LWS_WRITE_TEXT to send appropriate
230 * data on a websockets connection. Remember to allow the extra
231 * bytes before and after buf if LWS_WRITE_BINARY or LWS_WRITE_TEXT
234 * This function provides the way to issue data back to the client
235 * for both http and websocket protocols.
237 * In the case of sending using websocket protocol, be sure to allocate
238 * valid storage before and after buf as explained above. This scheme
239 * allows maximum efficiency of sending data and protocol in a single
240 * packet while not burdening the user code with any protocol knowledge.
242 * Return may be -1 for a fatal error needing connection close, or a
243 * positive number reflecting the amount of bytes actually sent. This
244 * can be less than the requested number of bytes due to OS memory
245 * pressure at any given time.
248 LWS_VISIBLE int libwebsocket_write(struct libwebsocket *wsi, unsigned char *buf,
249 size_t len, enum libwebsocket_write_protocol protocol)
254 int masked7 = wsi->mode == LWS_CONNMODE_WS_CLIENT;
255 unsigned char *dropmask = NULL;
256 unsigned char is_masked_bit = 0;
257 size_t orig_len = len;
258 struct lws_tokens eff_buf;
260 if (len == 0 && protocol != LWS_WRITE_CLOSE &&
261 protocol != LWS_WRITE_PING && protocol != LWS_WRITE_PONG) {
262 lwsl_warn("zero length libwebsocket_write attempt\n");
266 if (protocol == LWS_WRITE_HTTP ||
267 protocol == LWS_WRITE_HTTP_FINAL ||
268 protocol == LWS_WRITE_HTTP_HEADERS)
271 /* websocket protocol, either binary or text */
273 if (wsi->state != WSI_STATE_ESTABLISHED)
276 /* if we are continuing a frame that already had its header done */
278 if (wsi->u.ws.inside_frame)
279 goto do_more_inside_frame;
281 wsi->u.ws.clean_buffer = 1;
284 * give a chance to the extensions to modify payload
285 * pre-TX mangling is not allowed to truncate
287 eff_buf.token = (char *)buf;
288 eff_buf.token_len = len;
293 case LWS_WRITE_CLOSE:
296 if (lws_ext_callback_for_each_active(wsi,
297 LWS_EXT_CALLBACK_PAYLOAD_TX, &eff_buf, 0) < 0)
302 * an extension did something we need to keep... for example, if
303 * compression extension, it has already updated its state according
304 * to this being issued
306 if ((char *)buf != eff_buf.token)
308 * extension recreated it:
309 * need to buffer this if not all sent
311 wsi->u.ws.clean_buffer = 0;
313 buf = (unsigned char *)eff_buf.token;
314 len = eff_buf.token_len;
316 switch (wsi->ietf_spec_revision) {
321 dropmask = &buf[0 - pre];
322 is_masked_bit = 0x80;
325 switch (protocol & 0xf) {
327 n = LWS_WS_OPCODE_07__TEXT_FRAME;
329 case LWS_WRITE_BINARY:
330 n = LWS_WS_OPCODE_07__BINARY_FRAME;
332 case LWS_WRITE_CONTINUATION:
333 n = LWS_WS_OPCODE_07__CONTINUATION;
336 case LWS_WRITE_CLOSE:
337 n = LWS_WS_OPCODE_07__CLOSE;
340 * 06+ has a 2-byte status code in network order
341 * we can do this because we demand post-buf
344 if (wsi->u.ws.close_reason) {
345 /* reason codes count as data bytes */
347 buf[0] = wsi->u.ws.close_reason >> 8;
348 buf[1] = wsi->u.ws.close_reason;
353 n = LWS_WS_OPCODE_07__PING;
356 n = LWS_WS_OPCODE_07__PONG;
359 lwsl_warn("lws_write: unknown write opc / protocol\n");
363 if (!(protocol & LWS_WRITE_NO_FIN))
369 buf[-pre + 1] = len | is_masked_bit;
374 buf[-pre + 1] = 126 | is_masked_bit;
375 buf[-pre + 2] = len >> 8;
380 buf[-pre + 1] = 127 | is_masked_bit;
382 buf[-pre + 2] = (len >> 56) & 0x7f;
383 buf[-pre + 3] = len >> 48;
384 buf[-pre + 4] = len >> 40;
385 buf[-pre + 5] = len >> 32;
392 buf[-pre + 6] = len >> 24;
393 buf[-pre + 7] = len >> 16;
394 buf[-pre + 8] = len >> 8;
401 do_more_inside_frame:
404 * Deal with masking if we are in client -> server direction and
405 * the protocol demands it
408 if (wsi->mode == LWS_CONNMODE_WS_CLIENT) {
410 if (!wsi->u.ws.inside_frame)
411 if (libwebsocket_0405_frame_mask_generate(wsi)) {
412 lwsl_err("frame mask generation failed\n");
417 * in v7, just mask the payload
419 if (dropmask) { /* never set if already inside frame */
420 for (n = 4; n < (int)len + 4; n++)
421 dropmask[n] = dropmask[n] ^
422 wsi->u.ws.frame_masking_nonce_04[
423 (wsi->u.ws.frame_mask_index++) & 3];
425 /* copy the frame nonce into place */
426 memcpy(dropmask, wsi->u.ws.frame_masking_nonce_04, 4);
432 case LWS_WRITE_CLOSE:
433 /* lwsl_hexdump(&buf[-pre], len + post); */
435 case LWS_WRITE_HTTP_FINAL:
436 case LWS_WRITE_HTTP_HEADERS:
440 if (wsi->mode == LWS_CONNMODE_HTTP2_SERVING) {
441 unsigned char flags = 0;
443 n = LWS_HTTP2_FRAME_TYPE_DATA;
444 if (protocol == LWS_WRITE_HTTP_HEADERS) {
445 n = LWS_HTTP2_FRAME_TYPE_HEADERS;
446 flags = LWS_HTTP2_FLAG_END_HEADERS;
447 if (wsi->u.http2.send_END_STREAM)
448 flags |= LWS_HTTP2_FLAG_END_STREAM;
451 if ((protocol == LWS_WRITE_HTTP || protocol == LWS_WRITE_HTTP_FINAL) && wsi->u.http.content_length) {
452 wsi->u.http.content_remain -= len;
453 lwsl_info("%s: content_remain = %lu\n", __func__, wsi->u.http.content_remain);
454 if (!wsi->u.http.content_remain) {
455 lwsl_info("%s: selecting final write mode\n", __func__);
456 protocol = LWS_WRITE_HTTP_FINAL;
460 if (protocol == LWS_WRITE_HTTP_FINAL && wsi->u.http2.END_STREAM) {
461 lwsl_info("%s: setting END_STREAM\n", __func__);
462 flags |= LWS_HTTP2_FLAG_END_STREAM;
465 return lws_http2_frame_write(wsi, n, flags, wsi->u.http2.my_stream_id, len, buf);
468 return lws_issue_raw(wsi, (unsigned char *)buf - pre,
474 wsi->u.ws.inside_frame = 1;
477 * give any active extensions a chance to munge the buffer
478 * before send. We pass in a pointer to an lws_tokens struct
479 * prepared with the default buffer and content length that's in
480 * there. Rather than rewrite the default buffer, extensions
481 * that expect to grow the buffer can adapt .token to
482 * point to their own per-connection buffer in the extension
483 * user allocation. By default with no extensions or no
484 * extension callback handling, just the normal input buffer is
485 * used then so it is efficient.
487 * callback returns 1 in case it wants to spill more buffers
489 * This takes care of holding the buffer if send is incomplete, ie,
490 * if wsi->u.ws.clean_buffer is 0 (meaning an extension meddled with
491 * the buffer). If wsi->u.ws.clean_buffer is 1, it will instead
492 * return to the user code how much OF THE USER BUFFER was consumed.
495 n = lws_issue_raw_ext_access(wsi, buf - pre, len + pre + post);
499 if (n == len + pre + post) {
500 /* everything in the buffer was handled (or rebuffered...) */
501 wsi->u.ws.inside_frame = 0;
506 * it is how many bytes of user buffer got sent... may be < orig_len
507 * in which case callback when writable has already been arranged
508 * and user code can call libwebsocket_write() again with the rest
512 return n - (pre + post);
515 LWS_VISIBLE int libwebsockets_serve_http_file_fragment(
516 struct libwebsocket_context *context, struct libwebsocket *wsi)
521 while (!lws_send_pipe_choked(wsi)) {
523 if (wsi->truncated_send_len) {
524 if (lws_issue_raw(wsi, wsi->truncated_send_malloc +
525 wsi->truncated_send_offset,
526 wsi->truncated_send_len) < 0) {
527 lwsl_info("closing from libwebsockets_serve_http_file_fragment\n");
533 if (wsi->u.http.filepos == wsi->u.http.filelen)
536 compatible_file_read(n, wsi->u.http.fd, context->service_buffer,
537 sizeof(context->service_buffer));
539 return -1; /* caller will close */
541 wsi->u.http.filepos += n;
542 m = libwebsocket_write(wsi, context->service_buffer, n,
543 wsi->u.http.filepos == wsi->u.http.filelen ? LWS_WRITE_HTTP_FINAL : LWS_WRITE_HTTP);
548 /* adjust for what was not sent */
549 if (compatible_file_seek_cur(wsi->u.http.fd, m - n) < 0)
553 if (!wsi->truncated_send_len &&
554 wsi->u.http.filepos == wsi->u.http.filelen) {
555 wsi->state = WSI_STATE_HTTP;
557 if (wsi->protocol->callback)
558 /* ignore callback returned value */
559 user_callback_handle_rxflow(
560 wsi->protocol->callback, context, wsi,
561 LWS_CALLBACK_HTTP_FILE_COMPLETION,
562 wsi->user_space, NULL, 0);
563 return 1; /* >0 indicates completed */
567 lwsl_info("choked before able to send whole file (post)\n");
568 libwebsocket_callback_on_writable(context, wsi);
570 return 0; /* indicates further processing must be done */
574 lws_ssl_capable_read_no_ssl(struct libwebsocket_context *context,
575 struct libwebsocket *wsi, unsigned char *buf, int len)
579 n = recv(wsi->sock, buf, len, 0);
583 lwsl_warn("error on reading from skt\n");
584 return LWS_SSL_CAPABLE_ERROR;
588 lws_ssl_capable_write_no_ssl(struct libwebsocket *wsi, unsigned char *buf, int len)
592 n = send(wsi->sock, buf, len, 0);
596 if (LWS_ERRNO == LWS_EAGAIN ||
597 LWS_ERRNO == LWS_EWOULDBLOCK ||
598 LWS_ERRNO == LWS_EINTR) {
599 if (LWS_ERRNO == LWS_EWOULDBLOCK)
600 lws_set_blocking_send(wsi);
602 return LWS_SSL_CAPABLE_MORE_SERVICE;
604 lwsl_debug("ERROR writing len %d to skt %d\n", len, n);
605 return LWS_SSL_CAPABLE_ERROR;