lib/http2.c

   1 /*
   2  * libwebsockets - small server side websockets and web server implementation
   3  *
   4  * Copyright (C) 2010-2013 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
  23 #include "private-libwebsockets.h"
  24
  25 const struct http2_settings lws_http2_default_settings = { {
  26         0,
  27         /* LWS_HTTP2_SETTINGS__HEADER_TABLE_SIZE */             4096,
  28         /* LWS_HTTP2_SETTINGS__ENABLE_PUSH */                      1,
  29         /* LWS_HTTP2_SETTINGS__MAX_CONCURRENT_STREAMS */         100,
  30         /* LWS_HTTP2_SETTINGS__INITIAL_WINDOW_SIZE */          65535,
  31         /* LWS_HTTP2_SETTINGS__MAX_FRAME_SIZE */               16384,
  32         /* LWS_HTTP2_SETTINGS__MAX_HEADER_LIST_SIZE */            ~0,
  33 }};
  34
  35
  36 void lws_http2_init(struct http2_settings *settings)
  37 {
  38         memcpy(settings, lws_http2_default_settings.setting, sizeof(*settings));
  39 }
  40
  41 struct lws *
  42 lws_http2_wsi_from_id(struct lws *wsi, unsigned int sid)
  43 {
  44         do {
  45                 if (wsi->u.http2.my_stream_id == sid)
  46                         return wsi;
  47
  48                 wsi = wsi->u.http2.next_child_wsi;
  49         } while (wsi);
  50
  51         return NULL;
  52 }
  53
  54 struct lws *
  55 lws_create_server_child_wsi(struct lws_context *context, struct lws *parent_wsi,
  56                             unsigned int sid)
  57 {
  58         struct lws *wsi = lws_create_new_server_wsi(context);
  59
  60         if (!wsi)
  61                 return NULL;
  62
  63         /* no more children allowed by parent */
  64         if (parent_wsi->u.http2.child_count + 1 ==
  65             parent_wsi->u.http2.peer_settings.setting[
  66                         LWS_HTTP2_SETTINGS__MAX_CONCURRENT_STREAMS])
  67                 return NULL;
  68
  69         lws_http2_init(&wsi->u.http2.peer_settings);
  70         lws_http2_init(&wsi->u.http2.my_settings);
  71         wsi->u.http2.stream_id = sid;
  72         wsi->u.http2.my_stream_id = sid;
  73
  74         wsi->u.http2.parent_wsi = parent_wsi;
  75         wsi->u.http2.next_child_wsi = parent_wsi->u.http2.next_child_wsi;
  76         parent_wsi->u.http2.next_child_wsi = wsi;
  77         parent_wsi->u.http2.child_count++;
  78
  79         wsi->u.http2.my_priority = 16;
  80         wsi->u.http2.tx_credit = 65535;
  81
  82         wsi->state = LWSS_HTTP2_ESTABLISHED;
  83         wsi->mode = parent_wsi->mode;
  84
  85         wsi->protocol = &context->protocols[0];
  86         lws_ensure_user_space(wsi);
  87
  88         lwsl_info("%s: %p new child %p, sid %d, user_space=%p\n", __func__,
  89                   parent_wsi, wsi, sid, wsi->user_space);
  90
  91         return wsi;
  92 }
  93
  94 int lws_remove_server_child_wsi(struct lws_context *context, struct lws *wsi)
  95 {
  96         struct lws **w = &wsi->u.http2.parent_wsi;
  97         do {
  98                 if (*w == wsi) {
  99                         *w = wsi->u.http2.next_child_wsi;
 100                         (wsi->u.http2.parent_wsi)->u.http2.child_count--;
 101                         return 0;
 102                 }
 103
 104                 w = &((*w)->u.http2.next_child_wsi);
 105         } while (*w);
 106
 107         lwsl_err("%s: can't find %p\n", __func__, wsi);
 108         return 1;
 109 }
 110
 111 int
 112 lws_http2_interpret_settings_payload(struct http2_settings *settings,
 113                                      unsigned char *buf, int len)
 114 {
 115         unsigned int a, b;
 116
 117         if (!len)
 118                 return 0;
 119
 120         if (len < LWS_HTTP2_SETTINGS_LENGTH)
 121                 return 1;
 122
 123         while (len >= LWS_HTTP2_SETTINGS_LENGTH) {
 124                 a = (buf[0] << 8) | buf[1];
 125                 if (a < LWS_HTTP2_SETTINGS__COUNT) {
 126                         b = buf[2] << 24 | buf[3] << 16 | buf[4] << 8 | buf[5];
 127                         settings->setting[a] = b;
 128                         lwsl_info("http2 settings %d <- 0x%x\n", a, b);
 129                 }
 130                 len -= LWS_HTTP2_SETTINGS_LENGTH;
 131                 buf += LWS_HTTP2_SETTINGS_LENGTH;
 132         }
 133
 134         if (len)
 135                 return 1;
 136
 137         return 0;
 138 }
 139
 140 struct lws *lws_http2_get_network_wsi(struct lws *wsi)
 141 {
 142         while (wsi->u.http2.parent_wsi)
 143                 wsi = wsi->u.http2.parent_wsi;
 144
 145         return wsi;
 146 }
 147
 148 int lws_http2_frame_write(struct lws *wsi, int type, int flags,
 149                           unsigned int sid, unsigned int len, unsigned char *buf)
 150 {
 151         struct lws *wsi_eff = lws_http2_get_network_wsi(wsi);
 152         unsigned char *p = &buf[-LWS_HTTP2_FRAME_HEADER_LENGTH];
 153         int n;
 154
 155         *p++ = len >> 16;
 156         *p++ = len >> 8;
 157         *p++ = len;
 158         *p++ = type;
 159         *p++ = flags;
 160         *p++ = sid >> 24;
 161         *p++ = sid >> 16;
 162         *p++ = sid >> 8;
 163         *p++ = sid;
 164
 165         lwsl_info("%s: %p (eff %p). type %d, flags 0x%x, sid=%d, len=%d\n",
 166                   __func__, wsi, wsi_eff, type, flags, sid, len,
 167                   wsi->u.http2.tx_credit);
 168
 169         if (type == LWS_HTTP2_FRAME_TYPE_DATA) {
 170                 if (wsi->u.http2.tx_credit < len)
 171                         lwsl_err("%s: %p: sending payload len %d"
 172                                  " but tx_credit only %d!\n", len,
 173                                  wsi->u.http2.tx_credit);
 174                 wsi->u.http2.tx_credit -= len;
 175         }
 176
 177         n = lws_issue_raw(wsi_eff, &buf[-LWS_HTTP2_FRAME_HEADER_LENGTH],
 178                           len + LWS_HTTP2_FRAME_HEADER_LENGTH);
 179         if (n >= LWS_HTTP2_FRAME_HEADER_LENGTH)
 180                 return n - LWS_HTTP2_FRAME_HEADER_LENGTH;
 181
 182         return n;
 183 }
 184
 185 static void lws_http2_settings_write(struct lws *wsi, int n, unsigned char *buf)
 186 {
 187         *buf++ = n >> 8;
 188         *buf++ = n;
 189         *buf++ = wsi->u.http2.my_settings.setting[n] >> 24;
 190         *buf++ = wsi->u.http2.my_settings.setting[n] >> 16;
 191         *buf++ = wsi->u.http2.my_settings.setting[n] >> 8;
 192         *buf = wsi->u.http2.my_settings.setting[n];
 193 }
 194
 195 static const char * https_client_preface =
 196         "PRI * HTTP/2.0\x0d\x0a\x0d\x0aSM\x0d\x0a\x0d\x0a";
 197
 198 int
 199 lws_http2_parser(struct lws *wsi, unsigned char c)
 200 {
 201         struct lws_context *context = wsi->context;
 202         struct lws *swsi;
 203         int n;
 204
 205         switch (wsi->state) {
 206         case LWSS_HTTP2_AWAIT_CLIENT_PREFACE:
 207                 if (https_client_preface[wsi->u.http2.count++] != c)
 208                         return 1;
 209
 210                 if (!https_client_preface[wsi->u.http2.count]) {
 211                         lwsl_info("http2: %p: established\n", wsi);
 212                         wsi->state = LWSS_HTTP2_ESTABLISHED_PRE_SETTINGS;
 213                         wsi->u.http2.count = 0;
 214                         wsi->u.http2.tx_credit = 65535;
 215
 216                         /*
 217                          * we must send a settings frame -- empty one is OK...
 218                          * that must be the first thing sent by server
 219                          * and the peer must send a SETTINGS with ACK flag...
 220                          */
 221
 222                         lws_set_protocol_write_pending(wsi,
 223                                                        LWS_PPS_HTTP2_MY_SETTINGS);
 224                 }
 225                 break;
 226
 227         case LWSS_HTTP2_ESTABLISHED_PRE_SETTINGS:
 228         case LWSS_HTTP2_ESTABLISHED:
 229                 if (wsi->u.http2.frame_state == LWS_HTTP2_FRAME_HEADER_LENGTH) { // payload
 230                         wsi->u.http2.count++;
 231                         wsi->u.http2.stream_wsi->u.http2.count = wsi->u.http2.count;
 232                         /* applies to wsi->u.http2.stream_wsi which may be wsi*/
 233                         switch(wsi->u.http2.type) {
 234                         case LWS_HTTP2_FRAME_TYPE_SETTINGS:
 235                                 wsi->u.http2.stream_wsi->u.http2.one_setting[wsi->u.http2.count % LWS_HTTP2_SETTINGS_LENGTH] = c;
 236                                 if (wsi->u.http2.count % LWS_HTTP2_SETTINGS_LENGTH == LWS_HTTP2_SETTINGS_LENGTH - 1)
 237                                         if (lws_http2_interpret_settings_payload(
 238                                              &wsi->u.http2.stream_wsi->u.http2.peer_settings,
 239                                              wsi->u.http2.one_setting,
 240                                              LWS_HTTP2_SETTINGS_LENGTH))
 241                                                 return 1;
 242                                 break;
 243                         case LWS_HTTP2_FRAME_TYPE_CONTINUATION:
 244                         case LWS_HTTP2_FRAME_TYPE_HEADERS:
 245                                 lwsl_info(" %02X\n", c);
 246                                 if (lws_hpack_interpret(wsi->u.http2.stream_wsi, c))
 247                                         return 1;
 248                                 break;
 249                         case LWS_HTTP2_FRAME_TYPE_GOAWAY:
 250                                 if (wsi->u.http2.count >= 5 && wsi->u.http2.count <= 8) {
 251                                         wsi->u.http2.hpack_e_dep <<= 8;
 252                                         wsi->u.http2.hpack_e_dep |= c;
 253                                         if (wsi->u.http2.count == 8) {
 254                                                 lwsl_info("goaway err 0x%x\n", wsi->u.http2.hpack_e_dep);
 255                                         }
 256                                 }
 257                                 wsi->u.http2.GOING_AWAY = 1;
 258                                 break;
 259                         case LWS_HTTP2_FRAME_TYPE_DATA:
 260                                 break;
 261                         case LWS_HTTP2_FRAME_TYPE_PRIORITY:
 262                                 break;
 263                         case LWS_HTTP2_FRAME_TYPE_RST_STREAM:
 264                                 break;
 265                         case LWS_HTTP2_FRAME_TYPE_PUSH_PROMISE:
 266                                 break;
 267                         case LWS_HTTP2_FRAME_TYPE_PING:
 268                                 if (wsi->u.http2.flags & LWS_HTTP2_FLAG_SETTINGS_ACK) { // ack
 269                                 } else { /* they're sending us a ping request */
 270                                         if (wsi->u.http2.count > 8)
 271                                                 return 1;
 272                                         wsi->u.http2.ping_payload[wsi->u.http2.count - 1] = c;
 273                                 }
 274                                 break;
 275                         case LWS_HTTP2_FRAME_TYPE_WINDOW_UPDATE:
 276                                 wsi->u.http2.hpack_e_dep <<= 8;
 277                                 wsi->u.http2.hpack_e_dep |= c;
 278                                 break;
 279                         }
 280                         if (wsi->u.http2.count != wsi->u.http2.length)
 281                                 break;
 282
 283                         /* end of frame */
 284
 285                         wsi->u.http2.frame_state = 0;
 286                         wsi->u.http2.count = 0;
 287                         swsi = wsi->u.http2.stream_wsi;
 288                         /* set our initial window size */
 289                         if (!wsi->u.http2.initialized) {
 290                                 wsi->u.http2.tx_credit = wsi->u.http2.peer_settings.setting[LWS_HTTP2_SETTINGS__INITIAL_WINDOW_SIZE];
 291                                 lwsl_info("initial tx credit on master conn %p: %d\n", wsi, wsi->u.http2.tx_credit);
 292                                 wsi->u.http2.initialized = 1;
 293                         }
 294                         switch (wsi->u.http2.type) {
 295                         case LWS_HTTP2_FRAME_TYPE_HEADERS:
 296                                 /* service the http request itself */
 297                                 lwsl_info("servicing initial http request, wsi=%p, stream wsi=%p\n", wsi, wsi->u.http2.stream_wsi);
 298                                 n = lws_http_action(swsi);
 299                                 (void)n;
 300                                 lwsl_info("  action result %d\n", n);
 301                                 break;
 302                         case LWS_HTTP2_FRAME_TYPE_PING:
 303                                 if (wsi->u.http2.flags & LWS_HTTP2_FLAG_SETTINGS_ACK) { // ack
 304                                 } else { /* they're sending us a ping request */
 305                                         lws_set_protocol_write_pending(wsi, LWS_PPS_HTTP2_PONG);
 306                                 }
 307                                 break;
 308                         case LWS_HTTP2_FRAME_TYPE_WINDOW_UPDATE:
 309                                 wsi->u.http2.hpack_e_dep &= ~(1 << 31);
 310                                 if ((long long)swsi->u.http2.tx_credit + (unsigned long long)wsi->u.http2.hpack_e_dep > (~(1 << 31)))
 311                                         return 1; /* actually need to close swsi not the whole show */
 312                                 swsi->u.http2.tx_credit += wsi->u.http2.hpack_e_dep;
 313                                 if (swsi->u.http2.waiting_tx_credit && swsi->u.http2.tx_credit > 0) {
 314                                         lwsl_info("%s: %p: waiting_tx_credit -> wait on writeable\n", __func__, wsi);
 315                                         swsi->u.http2.waiting_tx_credit = 0;
 316                                         lws_callback_on_writable(swsi);
 317                                 }
 318                                 break;
 319                         }
 320                         break;
 321                 }
 322                 switch (wsi->u.http2.frame_state++) {
 323                 case 0:
 324                         wsi->u.http2.length = c;
 325                         break;
 326                 case 1:
 327                 case 2:
 328                         wsi->u.http2.length <<= 8;
 329                         wsi->u.http2.length |= c;
 330                         break;
 331                 case 3:
 332                         wsi->u.http2.type = c;
 333                         break;
 334                 case 4:
 335                         wsi->u.http2.flags = c;
 336                         break;
 337                 case 5:
 338                 case 6:
 339                 case 7:
 340                 case 8:
 341                         wsi->u.http2.stream_id <<= 8;
 342                         wsi->u.http2.stream_id |= c;
 343                         break;
 344                 }
 345                 if (wsi->u.http2.frame_state == LWS_HTTP2_FRAME_HEADER_LENGTH) { /* frame header complete */
 346                         lwsl_info("frame: type 0x%x, flags 0x%x, sid 0x%x, len 0x%x\n",
 347                                   wsi->u.http2.type, wsi->u.http2.flags, wsi->u.http2.stream_id, wsi->u.http2.length);
 348                         wsi->u.http2.count = 0;
 349
 350                         wsi->u.http2.stream_wsi = wsi;
 351                         if (wsi->u.http2.stream_id)
 352                                 wsi->u.http2.stream_wsi = lws_http2_wsi_from_id(wsi, wsi->u.http2.stream_id);
 353
 354                         switch (wsi->u.http2.type) {
 355                         case LWS_HTTP2_FRAME_TYPE_SETTINGS:
 356                                 /* nonzero sid on settings is illegal */
 357                                 if (wsi->u.http2.stream_id)
 358                                         return 1;
 359
 360                                 if (wsi->u.http2.flags & LWS_HTTP2_FLAG_SETTINGS_ACK) { // ack
 361                                 } else
 362                                         /* non-ACK coming in means we must ACK it */
 363                                         lws_set_protocol_write_pending(wsi, LWS_PPS_HTTP2_ACK_SETTINGS);
 364                                 break;
 365                         case LWS_HTTP2_FRAME_TYPE_PING:
 366                                 if (wsi->u.http2.stream_id)
 367                                         return 1;
 368                                 if (wsi->u.http2.length != 8)
 369                                         return 1;
 370                                 break;
 371                         case LWS_HTTP2_FRAME_TYPE_CONTINUATION:
 372                                 if (wsi->u.http2.END_HEADERS)
 373                                         return 1;
 374                                 goto update_end_headers;
 375
 376                         case LWS_HTTP2_FRAME_TYPE_HEADERS:
 377                                 lwsl_info("LWS_HTTP2_FRAME_TYPE_HEADERS: stream_id = %d\n", wsi->u.http2.stream_id);
 378                                 if (!wsi->u.http2.stream_id)
 379                                         return 1;
 380                                 if (!wsi->u.http2.stream_wsi)
 381                                         wsi->u.http2.stream_wsi = lws_create_server_child_wsi(context, wsi, wsi->u.http2.stream_id);
 382
 383                                 /* END_STREAM means after servicing this, close the stream */
 384                                 wsi->u.http2.END_STREAM = !!(wsi->u.http2.flags & LWS_HTTP2_FLAG_END_STREAM);
 385                                 lwsl_info("%s: headers END_STREAM = %d\n",__func__, wsi->u.http2.END_STREAM);
 386 update_end_headers:
 387                                 /* no END_HEADERS means CONTINUATION must come */
 388                                 wsi->u.http2.END_HEADERS = !!(wsi->u.http2.flags & LWS_HTTP2_FLAG_END_HEADERS);
 389
 390                                 swsi = wsi->u.http2.stream_wsi;
 391                                 if (!swsi)
 392                                         return 1;
 393
 394
 395                                 /* prepare the hpack parser at the right start */
 396
 397                                 swsi->u.http2.flags = wsi->u.http2.flags;
 398                                 swsi->u.http2.length = wsi->u.http2.length;
 399                                 swsi->u.http2.END_STREAM = wsi->u.http2.END_STREAM;
 400
 401                                 if (swsi->u.http2.flags & LWS_HTTP2_FLAG_PADDED)
 402                                         swsi->u.http2.hpack = HPKS_OPT_PADDING;
 403                                 else
 404                                         if (swsi->u.http2.flags & LWS_HTTP2_FLAG_PRIORITY) {
 405                                                 swsi->u.http2.hpack = HKPS_OPT_E_DEPENDENCY;
 406                                                 swsi->u.http2.hpack_m = 4;
 407                                         } else
 408                                                 swsi->u.http2.hpack = HPKS_TYPE;
 409                                 lwsl_info("initial hpack state %d\n", swsi->u.http2.hpack);
 410                                 break;
 411                         case LWS_HTTP2_FRAME_TYPE_WINDOW_UPDATE:
 412                                 if (wsi->u.http2.length != 4)
 413                                         return 1;
 414                                 break;
 415                         }
 416                         if (wsi->u.http2.length == 0)
 417                                 wsi->u.http2.frame_state = 0;
 418
 419                 }
 420                 break;
 421         }
 422
 423         return 0;
 424 }
 425
 426 int lws_http2_do_pps_send(struct lws_context *context, struct lws *wsi)
 427 {
 428         unsigned char settings[LWS_PRE + 6 * LWS_HTTP2_SETTINGS__COUNT];
 429         struct lws *swsi;
 430         int n, m = 0;
 431
 432         lwsl_debug("%s: %p: %d\n", __func__, wsi, wsi->pps);
 433
 434         switch (wsi->pps) {
 435         case LWS_PPS_HTTP2_MY_SETTINGS:
 436                 for (n = 1; n < LWS_HTTP2_SETTINGS__COUNT; n++)
 437                         if (wsi->u.http2.my_settings.setting[n] != lws_http2_default_settings.setting[n]) {
 438                                 lws_http2_settings_write(wsi, n,
 439                                                          &settings[LWS_PRE + m]);
 440                                 m += sizeof(wsi->u.http2.one_setting);
 441                         }
 442                 n = lws_http2_frame_write(wsi, LWS_HTTP2_FRAME_TYPE_SETTINGS,
 443                                           0, LWS_HTTP2_STREAM_ID_MASTER, m,
 444                                           &settings[LWS_PRE]);
 445                 if (n != m) {
 446                         lwsl_info("send %d %d\n", n, m);
 447                         return 1;
 448                 }
 449                 break;
 450         case LWS_PPS_HTTP2_ACK_SETTINGS:
 451                 /* send ack ... always empty */
 452                 n = lws_http2_frame_write(wsi, LWS_HTTP2_FRAME_TYPE_SETTINGS,
 453                         1, LWS_HTTP2_STREAM_ID_MASTER, 0,
 454                         &settings[LWS_PRE]);
 455                 if (n) {
 456                         lwsl_err("ack tells %d\n", n);
 457                         return 1;
 458                 }
 459                 /* this is the end of the preface dance then? */
 460                 if (wsi->state == LWSS_HTTP2_ESTABLISHED_PRE_SETTINGS) {
 461                         wsi->state = LWSS_HTTP2_ESTABLISHED;
 462
 463                         wsi->u.http.fd = LWS_INVALID_FILE;
 464
 465                         if (lws_is_ssl(lws_http2_get_network_wsi(wsi))) {
 466                                 lwsl_info("skipping nonexistant ssl upgrade headers\n");
 467                                 break;
 468                         }
 469
 470                         /*
 471                          * we need to treat the headers from this upgrade
 472                          * as the first job.  These need to get
 473                          * shifted to stream ID 1
 474                          */
 475                         lwsl_info("%s: setting up sid 1\n", __func__);
 476
 477                         swsi = wsi->u.http2.stream_wsi = lws_create_server_child_wsi(context, wsi, 1);
 478                         /* pass on the initial headers to SID 1 */
 479                         swsi->u.http.ah = wsi->u.http.ah;
 480                         wsi->u.http.ah = NULL;
 481
 482                         lwsl_info("%s: inherited headers %p\n", __func__, swsi->u.http.ah);
 483                         swsi->u.http2.tx_credit = wsi->u.http2.peer_settings.setting[LWS_HTTP2_SETTINGS__INITIAL_WINDOW_SIZE];
 484                         lwsl_info("initial tx credit on conn %p: %d\n", swsi, swsi->u.http2.tx_credit);
 485                         swsi->u.http2.initialized = 1;
 486                         /* demanded by HTTP2 */
 487                         swsi->u.http2.END_STREAM = 1;
 488                         lwsl_info("servicing initial http request\n");
 489                         return lws_http_action(swsi);
 490                 }
 491                 break;
 492         case LWS_PPS_HTTP2_PONG:
 493                 memcpy(&settings[LWS_PRE], wsi->u.http2.ping_payload, 8);
 494                 n = lws_http2_frame_write(wsi, LWS_HTTP2_FRAME_TYPE_PING,
 495                                           LWS_HTTP2_FLAG_SETTINGS_ACK,
 496                                           LWS_HTTP2_STREAM_ID_MASTER, 8,
 497                                           &settings[LWS_PRE]);
 498                 if (n != 8) {
 499                         lwsl_info("send %d %d\n", n, m);
 500                         return 1;
 501                 }
 502                 break;
 503         default:
 504                 break;
 505         }
 506
 507         return 0;
 508 }
 509
 510 struct lws * lws_http2_get_nth_child(struct lws *wsi, int n)
 511 {
 512         do {
 513                 wsi = wsi->u.http2.next_child_wsi;
 514                 if (!wsi)
 515                         return NULL;
 516         } while (n--);
 517
 518         return wsi;
 519 }