lib/output.c

   1 /*
   2  * libwebsockets - small server side websockets and web server implementation
   3  *
   4  * Copyright (C) 2010-2015 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 #if 0
  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;
  32 #else
  33         int n;
  34         /* fetch the per-frame nonce */
  35
  36         n = lws_get_random(lws_get_context(wsi), wsi->u.ws.mask, 4);
  37         if (n != 4) {
  38                 lwsl_parser("Unable to read from random device %s %d\n",
  39                             SYSTEM_RANDOM_FILEPATH, n);
  40                 return 1;
  41         }
  42 #endif
  43         /* start masking from first byte of masking key buffer */
  44         wsi->u.ws.mask_idx = 0;
  45
  46         return 0;
  47 }
  48
  49 #ifdef _DEBUG
  50
  51 LWS_VISIBLE void lwsl_hexdump(void *vbuf, size_t len)
  52 {
  53         unsigned char *buf = (unsigned char *)vbuf;
  54         unsigned int n, m, start;
  55         char line[80];
  56         char *p;
  57
  58         lwsl_parser("\n");
  59
  60         for (n = 0; n < len;) {
  61                 start = n;
  62                 p = line;
  63
  64                 p += sprintf(p, "%04X: ", start);
  65
  66                 for (m = 0; m < 16 && n < len; m++)
  67                         p += sprintf(p, "%02X ", buf[n++]);
  68                 while (m++ < 16)
  69                         p += sprintf(p, "   ");
  70
  71                 p += sprintf(p, "   ");
  72
  73                 for (m = 0; m < 16 && (start + m) < len; m++) {
  74                         if (buf[start + m] >= ' ' && buf[start + m] < 127)
  75                                 *p++ = buf[start + m];
  76                         else
  77                                 *p++ = '.';
  78                 }
  79                 while (m++ < 16)
  80                         *p++ = ' ';
  81
  82                 *p++ = '\n';
  83                 *p = '\0';
  84                 lwsl_debug("%s", line);
  85         }
  86         lwsl_debug("\n");
  87 }
  88
  89 #endif
  90
  91 /*
  92  * notice this returns number of bytes consumed, or -1
  93  */
  94
  95 int lws_issue_raw(struct lws *wsi, unsigned char *buf, size_t len)
  96 {
  97         struct lws_context *context = lws_get_context(wsi);
  98         struct lws_context_per_thread *pt = &wsi->context->pt[(int)wsi->tsi];
  99         size_t real_len = len;
 100         unsigned int n;
 101         int m;
 102
 103         lws_stats_atomic_bump(wsi->context, pt, LWSSTATS_C_API_WRITE, 1);
 104
 105         if (!len)
 106                 return 0;
 107         /* just ignore sends after we cleared the truncation buffer */
 108         if (wsi->state == LWSS_FLUSHING_STORED_SEND_BEFORE_CLOSE &&
 109             !wsi->trunc_len)
 110                 return len;
 111
 112         if (wsi->trunc_len && (buf < wsi->trunc_alloc ||
 113             buf > (wsi->trunc_alloc + wsi->trunc_len + wsi->trunc_offset))) {
 114                 char dump[20];
 115                 strncpy(dump, (char *)buf, sizeof(dump) - 1);
 116                 dump[sizeof(dump) - 1] = '\0';
 117 #if defined(LWS_WITH_ESP8266)
 118                 lwsl_err("****** %p: Sending new %lu (%s), pending truncated ...\n",
 119                          wsi, (unsigned long)len, dump);
 120 #else
 121                 lwsl_err("****** %p: Sending new %lu (%s), pending truncated ...\n"
 122                          "       It's illegal to do an lws_write outside of\n"
 123                          "       the writable callback: fix your code",
 124                          wsi, (unsigned long)len, dump);
 125 #endif
 126                 assert(0);
 127
 128                 return -1;
 129         }
 130
 131         m = lws_ext_cb_active(wsi, LWS_EXT_CB_PACKET_TX_DO_SEND, &buf, len);
 132         if (m < 0)
 133                 return -1;
 134         if (m) /* handled */ {
 135                 n = m;
 136                 goto handle_truncated_send;
 137         }
 138
 139         if (!lws_socket_is_valid(wsi->desc.sockfd))
 140                 lwsl_warn("** error invalid sock but expected to send\n");
 141
 142         /* limit sending */
 143         if (wsi->protocol->tx_packet_size)
 144                 n = wsi->protocol->tx_packet_size;
 145         else {
 146                 n = wsi->protocol->rx_buffer_size;
 147                 if (!n)
 148                         n = context->pt_serv_buf_size;
 149         }
 150         n += LWS_PRE + 4;
 151         if (n > len)
 152                 n = len;
 153 #if defined(LWS_WITH_ESP8266)
 154         if (wsi->pending_send_completion) {
 155                 n = 0;
 156                 goto handle_truncated_send;
 157         }
 158 #endif
 159
 160         /* nope, send it on the socket directly */
 161         lws_latency_pre(context, wsi);
 162         n = lws_ssl_capable_write(wsi, buf, n);
 163         lws_latency(context, wsi, "send lws_issue_raw", n, n == len);
 164
 165         //lwsl_notice("lws_ssl_capable_write: %d\n", n);
 166
 167         switch (n) {
 168         case LWS_SSL_CAPABLE_ERROR:
 169                 /* we're going to close, let close know sends aren't possible */
 170                 wsi->socket_is_permanently_unusable = 1;
 171                 return -1;
 172         case LWS_SSL_CAPABLE_MORE_SERVICE:
 173                 /* nothing got sent, not fatal, retry the whole thing later */
 174                 n = 0;
 175                 break;
 176         }
 177
 178 handle_truncated_send:
 179         /*
 180          * we were already handling a truncated send?
 181          */
 182         if (wsi->trunc_len) {
 183                 lwsl_info("%p partial adv %d (vs %ld)\n", wsi, n, (long)real_len);
 184                 wsi->trunc_offset += n;
 185                 wsi->trunc_len -= n;
 186
 187                 if (!wsi->trunc_len) {
 188                         lwsl_info("***** %p partial send completed\n", wsi);
 189                         /* done with it, but don't free it */
 190                         n = real_len;
 191                         if (wsi->state == LWSS_FLUSHING_STORED_SEND_BEFORE_CLOSE) {
 192                                 lwsl_info("***** %p signalling to close now\n", wsi);
 193                                 return -1; /* retry closing now */
 194                         }
 195                 }
 196                 /* always callback on writeable */
 197                 lws_callback_on_writable(wsi);
 198
 199                 return n;
 200         }
 201
 202         if ((unsigned int)n == real_len)
 203                 /* what we just sent went out cleanly */
 204                 return n;
 205
 206         /*
 207          * Newly truncated send.  Buffer the remainder (it will get
 208          * first priority next time the socket is writable)
 209          */
 210         lwsl_debug("%p new partial sent %d from %lu total\n", wsi, n,
 211                     (unsigned long)real_len);
 212
 213         lws_stats_atomic_bump(wsi->context, pt, LWSSTATS_C_WRITE_PARTIALS, 1);
 214         lws_stats_atomic_bump(wsi->context, pt, LWSSTATS_B_PARTIALS_ACCEPTED_PARTS, n);
 215
 216         /*
 217          *  - if we still have a suitable malloc lying around, use it
 218          *  - or, if too small, reallocate it
 219          *  - or, if no buffer, create it
 220          */
 221         if (!wsi->trunc_alloc || real_len - n > wsi->trunc_alloc_len) {
 222                 lws_free(wsi->trunc_alloc);
 223
 224                 wsi->trunc_alloc_len = real_len - n;
 225                 wsi->trunc_alloc = lws_malloc(real_len - n);
 226                 if (!wsi->trunc_alloc) {
 227                         lwsl_err("truncated send: unable to malloc %lu\n",
 228                                  (unsigned long)(real_len - n));
 229                         return -1;
 230                 }
 231         }
 232         wsi->trunc_offset = 0;
 233         wsi->trunc_len = real_len - n;
 234         memcpy(wsi->trunc_alloc, buf + n, real_len - n);
 235
 236         /* since something buffered, force it to get another chance to send */
 237         lws_callback_on_writable(wsi);
 238
 239         return real_len;
 240 }
 241
 242 LWS_VISIBLE int lws_write(struct lws *wsi, unsigned char *buf, size_t len,
 243                           enum lws_write_protocol wp)
 244 {
 245         struct lws_context_per_thread *pt = &wsi->context->pt[(int)wsi->tsi];
 246         int masked7 = (wsi->mode == LWSCM_WS_CLIENT);
 247         unsigned char is_masked_bit = 0;
 248         unsigned char *dropmask = NULL;
 249         struct lws_tokens eff_buf;
 250         int pre = 0, n;
 251         size_t orig_len = len;
 252
 253         if (wsi->parent_carries_io) {
 254                 struct lws_write_passthru pas;
 255
 256                 pas.buf = buf;
 257                 pas.len = len;
 258                 pas.wp = wp;
 259                 pas.wsi = wsi;
 260
 261                 if (wsi->parent->protocol->callback(wsi->parent,
 262                                 LWS_CALLBACK_CHILD_WRITE_VIA_PARENT,
 263                                 wsi->parent->user_space,
 264                                 (void *)&pas, 0))
 265                         return 1;
 266
 267                 return len;
 268         }
 269
 270         lws_stats_atomic_bump(wsi->context, pt, LWSSTATS_C_API_LWS_WRITE, 1);
 271
 272         if ((int)len < 0) {
 273                 lwsl_err("%s: suspicious len int %d, ulong %lu\n", __func__,
 274                                 (int)len, (unsigned long)len);
 275                 return -1;
 276         }
 277
 278         lws_stats_atomic_bump(wsi->context, pt, LWSSTATS_B_WRITE, len);
 279
 280 #ifdef LWS_WITH_ACCESS_LOG
 281         wsi->access_log.sent += len;
 282 #endif
 283         if (wsi->vhost)
 284                 wsi->vhost->conn_stats.tx += len;
 285
 286         if (wsi->state == LWSS_ESTABLISHED && wsi->u.ws.tx_draining_ext) {
 287                 /* remove us from the list */
 288                 struct lws **w = &pt->tx_draining_ext_list;
 289
 290         //      lwsl_notice("%s: TX EXT DRAINING: Remove from list\n", __func__);
 291                 wsi->u.ws.tx_draining_ext = 0;
 292                 /* remove us from context draining ext list */
 293                 while (*w) {
 294                         if (*w == wsi) {
 295                                 *w = wsi->u.ws.tx_draining_ext_list;
 296                                 break;
 297                         }
 298                         w = &((*w)->u.ws.tx_draining_ext_list);
 299                 }
 300                 wsi->u.ws.tx_draining_ext_list = NULL;
 301                 wp = (wsi->u.ws.tx_draining_stashed_wp & 0xc0) |
 302                                 LWS_WRITE_CONTINUATION;
 303
 304                 lwsl_ext("FORCED draining wp to 0x%02X\n", wp);
 305         }
 306
 307         lws_restart_ws_ping_pong_timer(wsi);
 308
 309         if (wp == LWS_WRITE_HTTP ||
 310             wp == LWS_WRITE_HTTP_FINAL ||
 311             wp == LWS_WRITE_HTTP_HEADERS)
 312                 goto send_raw;
 313
 314         /* if not in a state to send stuff, then just send nothing */
 315
 316         if (wsi->state != LWSS_ESTABLISHED &&
 317             ((wsi->state != LWSS_RETURNED_CLOSE_ALREADY &&
 318               wsi->state != LWSS_AWAITING_CLOSE_ACK) ||
 319                             wp != LWS_WRITE_CLOSE))
 320                 return 0;
 321
 322         /* if we are continuing a frame that already had its header done */
 323
 324         if (wsi->u.ws.inside_frame) {
 325                 lwsl_debug("INSIDE FRAME\n");
 326                 goto do_more_inside_frame;
 327         }
 328
 329         wsi->u.ws.clean_buffer = 1;
 330
 331         /*
 332          * give a chance to the extensions to modify payload
 333          * the extension may decide to produce unlimited payload erratically
 334          * (eg, compression extension), so we require only that if he produces
 335          * something, it will be a complete fragment of the length known at
 336          * the time (just the fragment length known), and if he has
 337          * more we will come back next time he is writeable and allow him to
 338          * produce more fragments until he's drained.
 339          *
 340          * This allows what is sent each time it is writeable to be limited to
 341          * a size that can be sent without partial sends or blocking, allows
 342          * interleaving of control frames and other connection service.
 343          */
 344         eff_buf.token = (char *)buf;
 345         eff_buf.token_len = len;
 346
 347         switch ((int)wp) {
 348         case LWS_WRITE_PING:
 349         case LWS_WRITE_PONG:
 350         case LWS_WRITE_CLOSE:
 351                 break;
 352         default:
 353                 lwsl_debug("LWS_EXT_CB_PAYLOAD_TX\n");
 354                 n = lws_ext_cb_active(wsi, LWS_EXT_CB_PAYLOAD_TX, &eff_buf, wp);
 355                 if (n < 0)
 356                         return -1;
 357
 358                 if (n && eff_buf.token_len) {
 359                         lwsl_debug("drain len %d\n", (int)eff_buf.token_len);
 360                         /* extension requires further draining */
 361                         wsi->u.ws.tx_draining_ext = 1;
 362                         wsi->u.ws.tx_draining_ext_list = pt->tx_draining_ext_list;
 363                         pt->tx_draining_ext_list = wsi;
 364                         /* we must come back to do more */
 365                         lws_callback_on_writable(wsi);
 366                         /*
 367                          * keep a copy of the write type for the overall
 368                          * action that has provoked generation of these
 369                          * fragments, so the last guy can use its FIN state.
 370                          */
 371                         wsi->u.ws.tx_draining_stashed_wp = wp;
 372                         /* this is definitely not actually the last fragment
 373                          * because the extension asserted he has more coming
 374                          * So make sure this intermediate one doesn't go out
 375                          * with a FIN.
 376                          */
 377                         wp |= LWS_WRITE_NO_FIN;
 378                 }
 379
 380                 if (eff_buf.token_len && wsi->u.ws.stashed_write_pending) {
 381                         wsi->u.ws.stashed_write_pending = 0;
 382                         wp = (wp &0xc0) | (int)wsi->u.ws.stashed_write_type;
 383                 }
 384         }
 385
 386         /*
 387          * an extension did something we need to keep... for example, if
 388          * compression extension, it has already updated its state according
 389          * to this being issued
 390          */
 391         if ((char *)buf != eff_buf.token) {
 392                 /*
 393                  * ext might eat it, but not have anything to issue yet.
 394                  * In that case we have to follow his lead, but stash and
 395                  * replace the write type that was lost here the first time.
 396                  */
 397                 if (len && !eff_buf.token_len) {
 398                         if (!wsi->u.ws.stashed_write_pending)
 399                                 wsi->u.ws.stashed_write_type = (char)wp & 0x3f;
 400                         wsi->u.ws.stashed_write_pending = 1;
 401                         return len;
 402                 }
 403                 /*
 404                  * extension recreated it:
 405                  * need to buffer this if not all sent
 406                  */
 407                 wsi->u.ws.clean_buffer = 0;
 408         }
 409
 410         buf = (unsigned char *)eff_buf.token;
 411         len = eff_buf.token_len;
 412
 413         lwsl_debug("%p / %d\n", buf, (int)len);
 414
 415         if (!buf) {
 416                 lwsl_err("null buf (%d)\n", (int)len);
 417                 return -1;
 418         }
 419
 420         switch (wsi->ietf_spec_revision) {
 421         case 13:
 422                 if (masked7) {
 423                         pre += 4;
 424                         dropmask = &buf[0 - pre];
 425                         is_masked_bit = 0x80;
 426                 }
 427
 428                 switch (wp & 0xf) {
 429                 case LWS_WRITE_TEXT:
 430                         n = LWSWSOPC_TEXT_FRAME;
 431                         break;
 432                 case LWS_WRITE_BINARY:
 433                         n = LWSWSOPC_BINARY_FRAME;
 434                         break;
 435                 case LWS_WRITE_CONTINUATION:
 436                         n = LWSWSOPC_CONTINUATION;
 437                         break;
 438
 439                 case LWS_WRITE_CLOSE:
 440                         n = LWSWSOPC_CLOSE;
 441                         break;
 442                 case LWS_WRITE_PING:
 443                         n = LWSWSOPC_PING;
 444                         break;
 445                 case LWS_WRITE_PONG:
 446                         n = LWSWSOPC_PONG;
 447                         break;
 448                 default:
 449                         lwsl_warn("lws_write: unknown write opc / wp\n");
 450                         return -1;
 451                 }
 452
 453                 if (!(wp & LWS_WRITE_NO_FIN))
 454                         n |= 1 << 7;
 455
 456                 if (len < 126) {
 457                         pre += 2;
 458                         buf[-pre] = n;
 459                         buf[-pre + 1] = (unsigned char)(len | is_masked_bit);
 460                 } else {
 461                         if (len < 65536) {
 462                                 pre += 4;
 463                                 buf[-pre] = n;
 464                                 buf[-pre + 1] = 126 | is_masked_bit;
 465                                 buf[-pre + 2] = (unsigned char)(len >> 8);
 466                                 buf[-pre + 3] = (unsigned char)len;
 467                         } else {
 468                                 pre += 10;
 469                                 buf[-pre] = n;
 470                                 buf[-pre + 1] = 127 | is_masked_bit;
 471 #if defined __LP64__
 472                                         buf[-pre + 2] = (len >> 56) & 0x7f;
 473                                         buf[-pre + 3] = len >> 48;
 474                                         buf[-pre + 4] = len >> 40;
 475                                         buf[-pre + 5] = len >> 32;
 476 #else
 477                                         buf[-pre + 2] = 0;
 478                                         buf[-pre + 3] = 0;
 479                                         buf[-pre + 4] = 0;
 480                                         buf[-pre + 5] = 0;
 481 #endif
 482                                 buf[-pre + 6] = (unsigned char)(len >> 24);
 483                                 buf[-pre + 7] = (unsigned char)(len >> 16);
 484                                 buf[-pre + 8] = (unsigned char)(len >> 8);
 485                                 buf[-pre + 9] = (unsigned char)len;
 486                         }
 487                 }
 488                 break;
 489         }
 490
 491 do_more_inside_frame:
 492
 493         /*
 494          * Deal with masking if we are in client -> server direction and
 495          * the wp demands it
 496          */
 497
 498         if (masked7) {
 499                 if (!wsi->u.ws.inside_frame)
 500                         if (lws_0405_frame_mask_generate(wsi)) {
 501                                 lwsl_err("frame mask generation failed\n");
 502                                 return -1;
 503                         }
 504
 505                 /*
 506                  * in v7, just mask the payload
 507                  */
 508                 if (dropmask) { /* never set if already inside frame */
 509                         for (n = 4; n < (int)len + 4; n++)
 510                                 dropmask[n] = dropmask[n] ^ wsi->u.ws.mask[
 511                                         (wsi->u.ws.mask_idx++) & 3];
 512
 513                         /* copy the frame nonce into place */
 514                         memcpy(dropmask, wsi->u.ws.mask, 4);
 515                 }
 516         }
 517
 518 send_raw:
 519         switch ((int)wp) {
 520         case LWS_WRITE_CLOSE:
 521 /*              lwsl_hexdump(&buf[-pre], len); */
 522         case LWS_WRITE_HTTP:
 523         case LWS_WRITE_HTTP_FINAL:
 524         case LWS_WRITE_HTTP_HEADERS:
 525         case LWS_WRITE_PONG:
 526         case LWS_WRITE_PING:
 527 #ifdef LWS_USE_HTTP2
 528                 if (wsi->mode == LWSCM_HTTP2_SERVING) {
 529                         unsigned char flags = 0;
 530
 531                         n = LWS_HTTP2_FRAME_TYPE_DATA;
 532                         if (wp == LWS_WRITE_HTTP_HEADERS) {
 533                                 n = LWS_HTTP2_FRAME_TYPE_HEADERS;
 534                                 flags = LWS_HTTP2_FLAG_END_HEADERS;
 535                                 if (wsi->u.http2.send_END_STREAM)
 536                                         flags |= LWS_HTTP2_FLAG_END_STREAM;
 537                         }
 538
 539                         if ((wp == LWS_WRITE_HTTP ||
 540                              wp == LWS_WRITE_HTTP_FINAL) &&
 541                             wsi->u.http.content_length) {
 542                                 wsi->u.http.content_remain -= len;
 543                                 lwsl_info("%s: content_remain = %llu\n", __func__,
 544                                           (unsigned long long)wsi->u.http.content_remain);
 545                                 if (!wsi->u.http.content_remain) {
 546                                         lwsl_info("%s: selecting final write mode\n", __func__);
 547                                         wp = LWS_WRITE_HTTP_FINAL;
 548                                 }
 549                         }
 550
 551                         if (wp == LWS_WRITE_HTTP_FINAL && wsi->u.http2.END_STREAM) {
 552                                 lwsl_info("%s: setting END_STREAM\n", __func__);
 553                                 flags |= LWS_HTTP2_FLAG_END_STREAM;
 554                         }
 555
 556                         return lws_http2_frame_write(wsi, n, flags,
 557                                         wsi->u.http2.my_stream_id, len, buf);
 558                 }
 559 #endif
 560                 return lws_issue_raw(wsi, (unsigned char *)buf - pre, len + pre);
 561         default:
 562                 break;
 563         }
 564
 565         /*
 566          * give any active extensions a chance to munge the buffer
 567          * before send.  We pass in a pointer to an lws_tokens struct
 568          * prepared with the default buffer and content length that's in
 569          * there.  Rather than rewrite the default buffer, extensions
 570          * that expect to grow the buffer can adapt .token to
 571          * point to their own per-connection buffer in the extension
 572          * user allocation.  By default with no extensions or no
 573          * extension callback handling, just the normal input buffer is
 574          * used then so it is efficient.
 575          *
 576          * callback returns 1 in case it wants to spill more buffers
 577          *
 578          * This takes care of holding the buffer if send is incomplete, ie,
 579          * if wsi->u.ws.clean_buffer is 0 (meaning an extension meddled with
 580          * the buffer).  If wsi->u.ws.clean_buffer is 1, it will instead
 581          * return to the user code how much OF THE USER BUFFER was consumed.
 582          */
 583
 584         n = lws_issue_raw_ext_access(wsi, buf - pre, len + pre);
 585         wsi->u.ws.inside_frame = 1;
 586         if (n <= 0)
 587                 return n;
 588
 589         if (n == (int)len + pre) {
 590                 /* everything in the buffer was handled (or rebuffered...) */
 591                 wsi->u.ws.inside_frame = 0;
 592                 return orig_len;
 593         }
 594
 595         /*
 596          * it is how many bytes of user buffer got sent... may be < orig_len
 597          * in which case callback when writable has already been arranged
 598          * and user code can call lws_write() again with the rest
 599          * later.
 600          */
 601
 602         return n - pre;
 603 }
 604
 605 LWS_VISIBLE int lws_serve_http_file_fragment(struct lws *wsi)
 606 {
 607         struct lws_context *context = wsi->context;
 608         struct lws_context_per_thread *pt = &context->pt[(int)wsi->tsi];
 609         struct lws_process_html_args args;
 610         lws_filepos_t amount, poss;
 611         unsigned char *p;
 612 #if defined(LWS_WITH_RANGES)
 613         unsigned char finished = 0;
 614 #endif
 615         int n, m;
 616
 617         // lwsl_notice("%s (trunc len %d)\n", __func__, wsi->trunc_len);
 618
 619         while (wsi->http2_substream || !lws_send_pipe_choked(wsi)) {
 620
 621                 if (wsi->trunc_len) {
 622                         if (lws_issue_raw(wsi, wsi->trunc_alloc +
 623                                           wsi->trunc_offset,
 624                                           wsi->trunc_len) < 0) {
 625                                 lwsl_info("%s: closing\n", __func__);
 626                                 goto file_had_it;
 627                         }
 628                         continue;
 629                 }
 630
 631                 if (wsi->u.http.filepos == wsi->u.http.filelen)
 632                         goto all_sent;
 633
 634                 n = 0;
 635
 636                 p = pt->serv_buf;
 637
 638 #if defined(LWS_WITH_RANGES)
 639                 if (wsi->u.http.range.count_ranges && !wsi->u.http.range.inside) {
 640
 641                         lwsl_notice("%s: doing range start %llu\n", __func__, wsi->u.http.range.start);
 642
 643                         if ((long long)lws_vfs_file_seek_cur(wsi->u.http.fop_fd,
 644                                                    wsi->u.http.range.start -
 645                                                    wsi->u.http.filepos) < 0)
 646                                 goto file_had_it;
 647
 648                         wsi->u.http.filepos = wsi->u.http.range.start;
 649
 650                         if (wsi->u.http.range.count_ranges > 1) {
 651                                 n =  lws_snprintf((char *)p, context->pt_serv_buf_size,
 652                                         "_lws\x0d\x0a"
 653                                         "Content-Type: %s\x0d\x0a"
 654                                         "Content-Range: bytes %llu-%llu/%llu\x0d\x0a"
 655                                         "\x0d\x0a",
 656                                         wsi->u.http.multipart_content_type,
 657                                         wsi->u.http.range.start,
 658                                         wsi->u.http.range.end,
 659                                         wsi->u.http.range.extent);
 660                                 p += n;
 661                         }
 662
 663                         wsi->u.http.range.budget = wsi->u.http.range.end -
 664                                                    wsi->u.http.range.start + 1;
 665                         wsi->u.http.range.inside = 1;
 666                 }
 667 #endif
 668
 669                 poss = context->pt_serv_buf_size - n;
 670
 671                 /*
 672                  * if there is a hint about how much we will do well to send at one time,
 673                  * restrict ourselves to only trying to send that.
 674                  */
 675                 if (wsi->protocol->tx_packet_size && poss > wsi->protocol->tx_packet_size)
 676                         poss = wsi->protocol->tx_packet_size;
 677
 678 #if defined(LWS_WITH_RANGES)
 679                 if (wsi->u.http.range.count_ranges) {
 680                         if (wsi->u.http.range.count_ranges > 1)
 681                                 poss -= 7; /* allow for final boundary */
 682                         if (poss > wsi->u.http.range.budget)
 683                                 poss = wsi->u.http.range.budget;
 684                 }
 685 #endif
 686                 if (wsi->sending_chunked) {
 687                         /* we need to drop the chunk size in here */
 688                         p += 10;
 689                         /* allow for the chunk to grow by 128 in translation */
 690                         poss -= 10 + 128;
 691                 }
 692
 693                 if (lws_vfs_file_read(wsi->u.http.fop_fd, &amount, p, poss) < 0)
 694                         goto file_had_it; /* caller will close */
 695
 696                 //lwsl_notice("amount %ld\n", amount);
 697
 698                 if (wsi->sending_chunked)
 699                         n = (int)amount;
 700                 else
 701                         n = (p - pt->serv_buf) + (int)amount;
 702                 if (n) {
 703                         lws_set_timeout(wsi, PENDING_TIMEOUT_HTTP_CONTENT,
 704                                         context->timeout_secs);
 705
 706                         if (wsi->sending_chunked) {
 707                                 args.p = (char *)p;
 708                                 args.len = n;
 709                                 args.max_len = (unsigned int)poss + 128;
 710                                 args.final = wsi->u.http.filepos + n ==
 711                                              wsi->u.http.filelen;
 712                                 if (user_callback_handle_rxflow(
 713                                      wsi->vhost->protocols[(int)wsi->protocol_interpret_idx].callback, wsi,
 714                                      LWS_CALLBACK_PROCESS_HTML,
 715                                      wsi->user_space, &args, 0) < 0)
 716                                         goto file_had_it;
 717                                 n = args.len;
 718                                 p = (unsigned char *)args.p;
 719                         } else
 720                                 p = pt->serv_buf;
 721
 722 #if defined(LWS_WITH_RANGES)
 723                         if (wsi->u.http.range.send_ctr + 1 ==
 724                                 wsi->u.http.range.count_ranges && // last range
 725                             wsi->u.http.range.count_ranges > 1 && // was 2+ ranges (ie, multipart)
 726                             wsi->u.http.range.budget - amount == 0) {// final part
 727                                 n += lws_snprintf((char *)pt->serv_buf + n, 6,
 728                                         "_lws\x0d\x0a"); // append trailing boundary
 729                                 lwsl_debug("added trailing boundary\n");
 730                         }
 731 #endif
 732                         m = lws_write(wsi, p, n,
 733                                       wsi->u.http.filepos == wsi->u.http.filelen ?
 734                                         LWS_WRITE_HTTP_FINAL :
 735                                         LWS_WRITE_HTTP
 736                                 );
 737                         if (m < 0)
 738                                 goto file_had_it;
 739
 740                         wsi->u.http.filepos += amount;
 741
 742 #if defined(LWS_WITH_RANGES)
 743                         if (wsi->u.http.range.count_ranges >= 1) {
 744                                 wsi->u.http.range.budget -= amount;
 745                                 if (wsi->u.http.range.budget == 0) {
 746                                         lwsl_notice("range budget exhausted\n");
 747                                         wsi->u.http.range.inside = 0;
 748                                         wsi->u.http.range.send_ctr++;
 749
 750                                         if (lws_ranges_next(&wsi->u.http.range) < 1) {
 751                                                 finished = 1;
 752                                                 goto all_sent;
 753                                         }
 754                                 }
 755                         }
 756 #endif
 757
 758                         if (m != n) {
 759                                 /* adjust for what was not sent */
 760                                 if (lws_vfs_file_seek_cur(wsi->u.http.fop_fd,
 761                                                            m - n) ==
 762                                                              (unsigned long)-1)
 763                                         goto file_had_it;
 764                         }
 765                 }
 766 all_sent:
 767                 if ((!wsi->trunc_len && wsi->u.http.filepos == wsi->u.http.filelen)
 768 #if defined(LWS_WITH_RANGES)
 769                     || finished)
 770 #else
 771                 )
 772 #endif
 773                      {
 774                         wsi->state = LWSS_HTTP;
 775                         /* we might be in keepalive, so close it off here */
 776                         lws_vfs_file_close(&wsi->u.http.fop_fd);
 777
 778                         lwsl_debug("file completed\n");
 779
 780                         if (wsi->protocol->callback)
 781                                 /* ignore callback returned value */
 782                                 if (user_callback_handle_rxflow(
 783                                      wsi->protocol->callback, wsi,
 784                                      LWS_CALLBACK_HTTP_FILE_COMPLETION,
 785                                      wsi->user_space, NULL, 0) < 0)
 786                                         return -1;
 787
 788                         return 1;  /* >0 indicates completed */
 789                 }
 790         }
 791
 792         lws_callback_on_writable(wsi);
 793
 794         return 0; /* indicates further processing must be done */
 795
 796 file_had_it:
 797         lws_vfs_file_close(&wsi->u.http.fop_fd);
 798
 799         return -1;
 800 }
 801
 802 #if LWS_POSIX
 803 LWS_VISIBLE int
 804 lws_ssl_capable_read_no_ssl(struct lws *wsi, unsigned char *buf, int len)
 805 {
 806         struct lws_context *context = wsi->context;
 807         struct lws_context_per_thread *pt = &context->pt[(int)wsi->tsi];
 808         int n;
 809
 810         lws_stats_atomic_bump(context, pt, LWSSTATS_C_API_READ, 1);
 811
 812         n = recv(wsi->desc.sockfd, (char *)buf, len, 0);
 813         if (n >= 0) {
 814                 if (wsi->vhost)
 815                         wsi->vhost->conn_stats.rx += n;
 816                 lws_stats_atomic_bump(context, pt, LWSSTATS_B_READ, n);
 817                 lws_restart_ws_ping_pong_timer(wsi);
 818                 return n;
 819         }
 820 #if LWS_POSIX
 821         if (LWS_ERRNO == LWS_EAGAIN ||
 822             LWS_ERRNO == LWS_EWOULDBLOCK ||
 823             LWS_ERRNO == LWS_EINTR)
 824                 return LWS_SSL_CAPABLE_MORE_SERVICE;
 825 #endif
 826         lwsl_notice("error on reading from skt : %d\n", LWS_ERRNO);
 827         return LWS_SSL_CAPABLE_ERROR;
 828 }
 829
 830 LWS_VISIBLE int
 831 lws_ssl_capable_write_no_ssl(struct lws *wsi, unsigned char *buf, int len)
 832 {
 833         int n = 0;
 834
 835 #if LWS_POSIX
 836         n = send(wsi->desc.sockfd, (char *)buf, len, MSG_NOSIGNAL);
 837 //      lwsl_info("%s: sent len %d result %d", __func__, len, n);
 838         if (n >= 0)
 839                 return n;
 840
 841         if (LWS_ERRNO == LWS_EAGAIN ||
 842             LWS_ERRNO == LWS_EWOULDBLOCK ||
 843             LWS_ERRNO == LWS_EINTR) {
 844                 if (LWS_ERRNO == LWS_EWOULDBLOCK) {
 845                         lws_set_blocking_send(wsi);
 846                 }
 847
 848                 return LWS_SSL_CAPABLE_MORE_SERVICE;
 849         }
 850 #else
 851         (void)n;
 852         (void)wsi;
 853         (void)buf;
 854         (void)len;
 855         // !!!
 856 #endif
 857
 858         lwsl_debug("ERROR writing len %d to skt fd %d err %d / errno %d\n", len, wsi->desc.sockfd, n, LWS_ERRNO);
 859         return LWS_SSL_CAPABLE_ERROR;
 860 }
 861 #endif
 862 LWS_VISIBLE int
 863 lws_ssl_pending_no_ssl(struct lws *wsi)
 864 {
 865         (void)wsi;
 866 #if defined(LWS_WITH_ESP32)
 867         return 100;
 868 #else
 869         return 0;
 870 #endif
 871 }