clean tidy the worst whitespace alignment probs due to mass token name length changes
[platform/upstream/libwebsockets.git] / lib / output.c
1 /*
2  * libwebsockets - small server side websockets and web server implementation
3  *
4  * Copyright (C) 2010-2014 Andy Green <andy@warmcat.com>
5  *
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.
10  *
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.
15  *
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,
19  *  MA  02110-1301  USA
20  */
21
22 #include "private-libwebsockets.h"
23
24 static int
25 lws_0405_frame_mask_generate(struct lws *wsi)
26 {
27         int n;
28
29         /* fetch the per-frame nonce */
30
31         n = lws_get_random(wsi->protocol->owning_server,
32                                            wsi->u.ws.frame_masking_nonce_04, 4);
33         if (n != 4) {
34                 lwsl_parser("Unable to read from random device %s %d\n",
35                                                      SYSTEM_RANDOM_FILEPATH, n);
36                 return 1;
37         }
38
39         /* start masking from first byte of masking key buffer */
40         wsi->u.ws.frame_mask_index = 0;
41
42         return 0;
43 }
44
45 #ifdef _DEBUG
46
47 LWS_VISIBLE void lwsl_hexdump(void *vbuf, size_t len)
48 {
49         unsigned int n;
50         unsigned int m;
51         unsigned int start;
52         unsigned char *buf = (unsigned char *)vbuf;
53         char line[80];
54         char *p;
55
56         lwsl_parser("\n");
57
58         for (n = 0; n < len;) {
59                 start = n;
60                 p = line;
61
62                 p += sprintf(p, "%04X: ", start);
63
64                 for (m = 0; m < 16 && n < len; m++)
65                         p += sprintf(p, "%02X ", buf[n++]);
66                 while (m++ < 16)
67                         p += sprintf(p, "   ");
68
69                 p += sprintf(p, "   ");
70
71                 for (m = 0; m < 16 && (start + m) < len; m++) {
72                         if (buf[start + m] >= ' ' && buf[start + m] < 127)
73                                 *p++ = buf[start + m];
74                         else
75                                 *p++ = '.';
76                 }
77                 while (m++ < 16)
78                         *p++ = ' ';
79
80                 *p++ = '\n';
81                 *p = '\0';
82                 lwsl_debug("%s", line);
83         }
84         lwsl_debug("\n");
85 }
86
87 #endif
88
89 /*
90  * notice this returns number of bytes consumed, or -1
91  */
92
93 int lws_issue_raw(struct lws *wsi, unsigned char *buf, size_t len)
94 {
95         struct lws_context *context = wsi->protocol->owning_server;
96         int n;
97         size_t real_len = len;
98         int m;
99         
100         if (!len)
101                 return 0;
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)
105                 return len;
106
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);
111                 assert(0);
112         }
113
114         m = lws_ext_callback_for_each_active(wsi,
115                         LWS_EXT_CALLBACK_PACKET_TX_DO_SEND, &buf, len);
116         if (m < 0)
117                 return -1;
118         if (m) /* handled */ {
119                 n = m;
120                 goto handle_truncated_send;
121         }
122
123         if (!lws_socket_is_valid(wsi->sock))
124                 lwsl_warn("** error invalid sock but expected to send\n");
125
126         /*
127          * nope, send it on the socket directly
128          */
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);
132
133         switch (n) {
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;
138                 return -1;
139         case LWS_SSL_CAPABLE_MORE_SERVICE:
140                 /* nothing got sent, not fatal, retry the whole thing later */
141                 n = 0;
142                 break;
143         }
144
145 handle_truncated_send:
146         /*
147          * we were already handling a truncated send?
148          */
149         if (wsi->truncated_send_len) {
150                 lwsl_info("***** %x partial send moved on by %d (vs %d)\n",
151                                                              wsi, n, real_len);
152                 wsi->truncated_send_offset += n;
153                 wsi->truncated_send_len -= n;
154
155                 if (!wsi->truncated_send_len) {
156                         lwsl_info("***** %x partial send completed\n", wsi);
157                         /* done with it, but don't free it */
158                         n = real_len;
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 */
162                         }
163                 }
164                 /* always callback on writeable */
165                 lws_callback_on_writable(
166                                              wsi->protocol->owning_server, wsi);
167
168                 return n;
169         }
170
171         if ((unsigned int)n == real_len)
172                 /* what we just sent went out cleanly */
173                 return n;
174
175         if (n && wsi->u.ws.clean_buffer)
176                 /*
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
181                  * payload)
182                  */
183                  return n;
184
185         /*
186          * Newly truncated send.  Buffer the remainder (it will get
187          * first priority next time the socket is writable)
188          */
189         lwsl_info("***** %x new partial sent %d from %d total\n",
190                                                       wsi, n, real_len);
191
192         /*
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
196          */
197         if (!wsi->truncated_send_malloc ||
198                         real_len - n > wsi->truncated_send_allocation) {
199                 lws_free(wsi->truncated_send_malloc);
200
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",
205                                                           real_len - n);
206                         return -1;
207                 }
208         }
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);
212
213         /* since something buffered, force it to get another chance to send */
214         lws_callback_on_writable(wsi->protocol->owning_server, wsi);
215
216         return real_len;
217 }
218
219 /**
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
233  *              are used.
234  *
235  *      This function provides the way to issue data back to the client
236  *      for both http and websocket protocols.
237  *
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.
242  *
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.
247  */
248
249 LWS_VISIBLE int lws_write(struct lws *wsi, unsigned char *buf,
250                           size_t len, enum lws_write_protocol protocol)
251 {
252         int n;
253         int pre = 0;
254         int post = 0;
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;
260
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");
264                 return 0;
265         }
266
267         if (protocol == LWS_WRITE_HTTP ||
268             protocol == LWS_WRITE_HTTP_FINAL ||
269             protocol == LWS_WRITE_HTTP_HEADERS)
270                 goto send_raw;
271
272         /* websocket protocol, either binary or text */
273
274         if (wsi->state != WSI_STATE_ESTABLISHED &&
275             !(wsi->state == WSI_STATE_RETURNED_CLOSE_ALREADY &&
276               protocol == LWS_WRITE_CLOSE))
277                 return -1;
278
279         /* if we are continuing a frame that already had its header done */
280
281         if (wsi->u.ws.inside_frame)
282                 goto do_more_inside_frame;
283
284         wsi->u.ws.clean_buffer = 1;
285
286         /*
287          * give a chance to the extensions to modify payload
288          * pre-TX mangling is not allowed to truncate
289          */
290         eff_buf.token = (char *)buf;
291         eff_buf.token_len = len;
292
293         switch (protocol) {
294         case LWS_WRITE_PING:
295         case LWS_WRITE_PONG:
296         case LWS_WRITE_CLOSE:
297                 break;
298         default:
299                 if (lws_ext_callback_for_each_active(wsi,
300                                LWS_EXT_CALLBACK_PAYLOAD_TX, &eff_buf, 0) < 0)
301                         return -1;
302         }
303
304         /*
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
308          */
309         if ((char *)buf != eff_buf.token)
310                 /*
311                  * extension recreated it:
312                  * need to buffer this if not all sent
313                  */
314                 wsi->u.ws.clean_buffer = 0;
315
316         buf = (unsigned char *)eff_buf.token;
317         len = eff_buf.token_len;
318
319         switch (wsi->ietf_spec_revision) {
320         case 13:
321
322                 if (masked7) {
323                         pre += 4;
324                         dropmask = &buf[0 - pre];
325                         is_masked_bit = 0x80;
326                 }
327
328                 switch (protocol & 0xf) {
329                 case LWS_WRITE_TEXT:
330                         n = LWS_WS_OPCODE_07__TEXT_FRAME;
331                         break;
332                 case LWS_WRITE_BINARY:
333                         n = LWS_WS_OPCODE_07__BINARY_FRAME;
334                         break;
335                 case LWS_WRITE_CONTINUATION:
336                         n = LWS_WS_OPCODE_07__CONTINUATION;
337                         break;
338
339                 case LWS_WRITE_CLOSE:
340                         n = LWS_WS_OPCODE_07__CLOSE;
341
342                         /*
343                          * 06+ has a 2-byte status code in network order
344                          * we can do this because we demand post-buf
345                          */
346
347                         if (wsi->u.ws.close_reason) {
348                                 /* reason codes count as data bytes */
349                                 buf -= 2;
350                                 buf[0] = wsi->u.ws.close_reason >> 8;
351                                 buf[1] = wsi->u.ws.close_reason;
352                                 len += 2;
353                         }
354                         break;
355                 case LWS_WRITE_PING:
356                         n = LWS_WS_OPCODE_07__PING;
357                         break;
358                 case LWS_WRITE_PONG:
359                         n = LWS_WS_OPCODE_07__PONG;
360                         break;
361                 default:
362                         lwsl_warn("lws_write: unknown write opc / protocol\n");
363                         return -1;
364                 }
365
366                 if (!(protocol & LWS_WRITE_NO_FIN))
367                         n |= 1 << 7;
368
369                 if (len < 126) {
370                         pre += 2;
371                         buf[-pre] = n;
372                         buf[-pre + 1] = len | is_masked_bit;
373                 } else {
374                         if (len < 65536) {
375                                 pre += 4;
376                                 buf[-pre] = n;
377                                 buf[-pre + 1] = 126 | is_masked_bit;
378                                 buf[-pre + 2] = len >> 8;
379                                 buf[-pre + 3] = len;
380                         } else {
381                                 pre += 10;
382                                 buf[-pre] = n;
383                                 buf[-pre + 1] = 127 | is_masked_bit;
384 #if defined __LP64__
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;
389 #else
390                                         buf[-pre + 2] = 0;
391                                         buf[-pre + 3] = 0;
392                                         buf[-pre + 4] = 0;
393                                         buf[-pre + 5] = 0;
394 #endif
395                                 buf[-pre + 6] = len >> 24;
396                                 buf[-pre + 7] = len >> 16;
397                                 buf[-pre + 8] = len >> 8;
398                                 buf[-pre + 9] = len;
399                         }
400                 }
401                 break;
402         }
403
404 do_more_inside_frame:
405
406         /*
407          * Deal with masking if we are in client -> server direction and
408          * the protocol demands it
409          */
410
411         if (wsi->mode == LWS_CONNMODE_WS_CLIENT) {
412
413                 if (!wsi->u.ws.inside_frame)
414                         if (lws_0405_frame_mask_generate(wsi)) {
415                                 lwsl_err("frame mask generation failed\n");
416                                 return -1;
417                         }
418
419                 /*
420                  * in v7, just mask the payload
421                  */
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];
427
428                         /* copy the frame nonce into place */
429                         memcpy(dropmask, wsi->u.ws.frame_masking_nonce_04, 4);
430                 }
431         }
432
433 send_raw:
434         switch (protocol) {
435         case LWS_WRITE_CLOSE:
436 /*              lwsl_hexdump(&buf[-pre], len + post); */
437         case LWS_WRITE_HTTP:
438         case LWS_WRITE_HTTP_FINAL:
439         case LWS_WRITE_HTTP_HEADERS:
440         case LWS_WRITE_PONG:
441         case LWS_WRITE_PING:
442 #ifdef LWS_USE_HTTP2
443                 if (wsi->mode == LWS_CONNMODE_HTTP2_SERVING) {
444                         unsigned char flags = 0;
445
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;
452                         }
453                         
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;
460                                 }
461                         }
462                         
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;
466                         }
467
468                         return lws_http2_frame_write(wsi, n, flags, wsi->u.http2.my_stream_id, len, buf);
469                 }
470 #endif
471                 return lws_issue_raw(wsi, (unsigned char *)buf - pre,
472                                                               len + pre + post);
473         default:
474                 break;
475         }
476
477         wsi->u.ws.inside_frame = 1;
478
479         /*
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.
489          *
490          * callback returns 1 in case it wants to spill more buffers
491          *
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.
496          */
497
498         n = lws_issue_raw_ext_access(wsi, buf - pre, len + pre + post);
499         if (n <= 0)
500                 return n;
501
502         if (n == (int)len + pre + post) {
503                 /* everything in the buffer was handled (or rebuffered...) */
504                 wsi->u.ws.inside_frame = 0;
505                 return orig_len;
506         }
507
508         /*
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
512          * later.
513          */
514
515         return n - (pre + post);
516 }
517
518 LWS_VISIBLE int lws_serve_http_file_fragment(struct lws_context *context,
519                                              struct lws *wsi)
520 {
521         int n;
522         int m;
523
524         while (!lws_send_pipe_choked(wsi)) {
525
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");
531                                 return -1;
532                         }
533                         continue;
534                 }
535
536                 if (wsi->u.http.filepos == wsi->u.http.filelen)
537                         goto all_sent;
538
539                 compatible_file_read(n, wsi->u.http.fd, context->service_buffer,
540                                                sizeof(context->service_buffer));
541                 if (n < 0)
542                         return -1; /* caller will close */
543                 if (n) {
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);
548                         if (m < 0)
549                                 return -1;
550
551                         if (m != n)
552                                 /* adjust for what was not sent */
553                                 if (compatible_file_seek_cur(wsi->u.http.fd, m - n) < 0)
554                                         return -1;
555                 }
556 all_sent:
557                 if (!wsi->truncated_send_len &&
558                                 wsi->u.http.filepos == wsi->u.http.filelen) {
559                         wsi->state = WSI_STATE_HTTP;
560
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;
564
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 */
572                 }
573         }
574
575         lwsl_info("choked before able to send whole file (post)\n");
576         lws_callback_on_writable(context, wsi);
577
578         return 0; /* indicates further processing must be done */
579 }
580
581 #if LWS_POSIX
582 LWS_VISIBLE int
583 lws_ssl_capable_read_no_ssl(struct lws_context *context,
584                             struct lws *wsi, unsigned char *buf, int len)
585 {
586         int n;
587
588         (void)context;
589
590         n = recv(wsi->sock, (char *)buf, len, 0);
591         if (n >= 0)
592                 return n;
593 #if LWS_POSIX
594         if (LWS_ERRNO == LWS_EAGAIN ||
595             LWS_ERRNO == LWS_EWOULDBLOCK ||
596             LWS_ERRNO == LWS_EINTR)
597                 return LWS_SSL_CAPABLE_MORE_SERVICE;
598 #endif
599         lwsl_warn("error on reading from skt\n");
600         return LWS_SSL_CAPABLE_ERROR;
601 }
602
603 LWS_VISIBLE int
604 lws_ssl_capable_write_no_ssl(struct lws *wsi, unsigned char *buf, int len)
605 {
606         int n = 0;
607
608 #if LWS_POSIX
609         n = send(wsi->sock, (char *)buf, len, MSG_NOSIGNAL);
610         if (n >= 0)
611                 return n;
612
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);
618
619                 return LWS_SSL_CAPABLE_MORE_SERVICE;
620         }
621 #else
622         (void)n;
623         (void)wsi;
624         (void)buf;
625         (void)len;
626         // !!!
627 #endif
628         
629         lwsl_debug("ERROR writing len %d to skt %d\n", len, n);
630         return LWS_SSL_CAPABLE_ERROR;
631 }
632 #endif
633 LWS_VISIBLE int
634 lws_ssl_pending_no_ssl(struct lws *wsi)
635 {
636         (void)wsi;
637         return 0;
638 }