lsquic_frame_reader.c revision a0e1aeee
1/* Copyright (c) 2017 - 2019 LiteSpeed Technologies Inc. See LICENSE. */ 2/* 3 * lsquic_frame_reader.c -- Read HTTP frames from stream 4 */ 5 6#ifndef WIN32 7#include <arpa/inet.h> 8#endif 9#include <assert.h> 10#include <ctype.h> 11#include <errno.h> 12#include <inttypes.h> 13#include <stdlib.h> 14#include <string.h> 15#include <sys/queue.h> 16 17#include "lshpack.h" 18#include "lsquic.h" 19#include "lsquic_mm.h" 20#include "lsquic_frame_common.h" 21#include "lsquic_frame_reader.h" 22#include "lsquic_http1x_if.h" 23#include "lsquic_headers.h" 24#include "lsquic_ev_log.h" 25#include "lsquic_hash.h" 26#include "lsquic_conn.h" 27 28#define LSQUIC_LOGGER_MODULE LSQLM_FRAME_READER 29#define LSQUIC_LOG_CONN_ID lsquic_conn_log_cid(lsquic_stream_conn(\ 30 fr->fr_stream)) 31#include "lsquic_logger.h" 32 33 34/* headers_state is used by HEADERS, PUSH_PROMISE, and CONTINUATION frames */ 35struct headers_state 36{ 37 enum http_frame_type 38 frame_type; 39 unsigned nread; /* Not counting pesw, only payload and padding */ 40 41 /* Values parsed out from pesw buffer: */ 42 uint32_t oth_stream_id; /* For HEADERS: ID of stream we depend on; 43 * for PUSH_PROMISE: promised stream ID. 44 */ 45 unsigned short weight; /* HEADERS only */ 46 signed char exclusive; /* HEADERS only */ 47 unsigned char pad_length; 48 49 unsigned char pseh; 50 51 /* PESW: Pad length, Exclusive, Stream Dependency, Weight. This is at 52 * most six bytes for HEADERS frame (RFC 7540, page 33) and five bytes 53 * for PUSH_PROMISE frame (Ibid, p. 40). 54 */ 55 unsigned char pesw_size; 56 unsigned char pesw_nread; 57 unsigned char pesw[6]; 58}; 59 60 61struct settings_state 62{ /* RFC 7540, Section 6.5.1 */ 63 unsigned char nread; 64 unsigned char set_buf[2 + 4]; /* We'll read one setting at a time */ 65}; 66 67 68struct priority_state 69{ /* RFC 7540, Section 6.3 */ 70 unsigned char nread; 71 union { 72 unsigned char prio_buf[sizeof(struct http_prio_frame)]; 73 struct http_prio_frame prio_frame; 74 } u; 75}; 76 77 78struct skip_state 79{ 80 uint32_t n_skipped; 81}; 82 83 84struct reader_state 85{ 86 unsigned nh_read; /* Number of bytes of header read */ 87 struct http_frame_header header; 88 enum { 89 READER_SKIP, 90 READER_HEADERS, 91 READER_PUSH_PROMISE, 92 READER_CONTIN, 93 READER_SETTINGS, 94 READER_PRIORITY, 95 } reader_type; 96 unsigned payload_length; 97 union { 98 struct headers_state headers_state; 99 struct skip_state skip_state; 100 struct settings_state settings_state; 101 struct priority_state priority_state; 102 } by_type; 103}; 104 105 106struct lsquic_frame_reader 107{ 108 struct lsquic_mm *fr_mm; 109 struct lshpack_dec *fr_hdec; 110 struct lsquic_stream *fr_stream; 111 fr_stream_read_f fr_read; 112 const struct frame_reader_callbacks 113 *fr_callbacks; 114 void *fr_cb_ctx; 115 const struct lsquic_hset_if *fr_hsi_if; 116 void *fr_hsi_ctx; 117 struct http1x_ctor_ctx fr_h1x_ctor_ctx; 118 /* The the header block is shared between HEADERS, PUSH_PROMISE, and 119 * CONTINUATION frames. It gets added to as block fragments come in. 120 */ 121 unsigned char *fr_header_block; 122#if LSQUIC_CONN_STATS 123 struct conn_stats *fr_conn_stats; 124#endif 125 unsigned fr_header_block_sz; 126 unsigned fr_max_headers_sz; /* 0 means no limit */ 127 enum frame_reader_flags fr_flags; 128 /* Keep some information about previous frame to catch framing errors. 129 */ 130 uint32_t fr_prev_stream_id; 131 enum http_frame_header_flags fr_prev_hfh_flags:8; 132 enum http_frame_type fr_prev_frame_type:8; 133 struct reader_state fr_state; 134}; 135 136 137#define reset_state(fr) do { \ 138 LSQ_DEBUG("reset state"); \ 139 (fr)->fr_state.nh_read = 0; \ 140} while (0) 141 142 143static uint32_t 144fr_get_stream_id (const struct lsquic_frame_reader *fr) 145{ 146 uint32_t stream_id; 147 assert(fr->fr_state.nh_read >= sizeof(fr->fr_state.header)); 148 memcpy(&stream_id, fr->fr_state.header.hfh_stream_id, sizeof(stream_id)); 149 stream_id = ntohl(stream_id); 150 return stream_id; 151} 152 153 154static const char * 155hft_to_string (enum http_frame_type hft) 156{ 157 static const char *const map[] = { 158 [HTTP_FRAME_DATA] = "HTTP_FRAME_DATA", 159 [HTTP_FRAME_HEADERS] = "HTTP_FRAME_HEADERS", 160 [HTTP_FRAME_PRIORITY] = "HTTP_FRAME_PRIORITY", 161 [HTTP_FRAME_RST_STREAM] = "HTTP_FRAME_RST_STREAM", 162 [HTTP_FRAME_SETTINGS] = "HTTP_FRAME_SETTINGS", 163 [HTTP_FRAME_PUSH_PROMISE] = "HTTP_FRAME_PUSH_PROMISE", 164 [HTTP_FRAME_PING] = "HTTP_FRAME_PING", 165 [HTTP_FRAME_GOAWAY] = "HTTP_FRAME_GOAWAY", 166 [HTTP_FRAME_WINDOW_UPDATE] = "HTTP_FRAME_WINDOW_UPDATE", 167 [HTTP_FRAME_CONTINUATION] = "HTTP_FRAME_CONTINUATION", 168 }; 169 if (hft < N_HTTP_FRAME_TYPES) 170 return map[hft]; 171 else 172 return "<unknown>"; 173} 174 175 176struct lsquic_frame_reader * 177lsquic_frame_reader_new (enum frame_reader_flags flags, 178 unsigned max_headers_sz, 179 struct lsquic_mm *mm, 180 struct lsquic_stream *stream, fr_stream_read_f read, 181 struct lshpack_dec *hdec, 182 const struct frame_reader_callbacks *cb, 183 void *frame_reader_cb_ctx, 184#if LSQUIC_CONN_STATS 185 struct conn_stats *conn_stats, 186#endif 187 const struct lsquic_hset_if *hsi_if, void *hsi_ctx) 188{ 189 struct lsquic_frame_reader *fr = malloc(sizeof(*fr)); 190 if (!fr) 191 return NULL; 192 fr->fr_mm = mm; 193 fr->fr_hdec = hdec; 194 fr->fr_flags = flags; 195 fr->fr_stream = stream; 196 fr->fr_read = read; 197 fr->fr_callbacks = cb; 198 fr->fr_cb_ctx = frame_reader_cb_ctx; 199 fr->fr_header_block = NULL; 200 fr->fr_max_headers_sz = max_headers_sz; 201 fr->fr_hsi_if = hsi_if; 202 if (hsi_if == lsquic_http1x_if) 203 { 204 fr->fr_h1x_ctor_ctx = (struct http1x_ctor_ctx) { 205 .conn = lsquic_stream_conn(stream), 206 .max_headers_sz = fr->fr_max_headers_sz, 207 .is_server = fr->fr_flags & FRF_SERVER, 208 }; 209 fr->fr_hsi_ctx = &fr->fr_h1x_ctor_ctx; 210 } 211 else 212 fr->fr_hsi_ctx = hsi_ctx; 213 reset_state(fr); 214#if LSQUIC_CONN_STATS 215 fr->fr_conn_stats = conn_stats; 216#endif 217 return fr; 218} 219 220 221void 222lsquic_frame_reader_destroy (struct lsquic_frame_reader *fr) 223{ 224 free(fr->fr_header_block); 225 free(fr); 226} 227 228 229#define RETURN_ERROR(nread) do { \ 230 assert(nread <= 0); \ 231 if (0 == nread) \ 232 { \ 233 LSQ_INFO("%s: unexpected EOF", __func__); \ 234 return -1; \ 235 } \ 236 else \ 237 { \ 238 LSQ_WARN("%s: error reading from stream: %s", __func__, \ 239 strerror(errno)); \ 240 return -1; \ 241 } \ 242} while (0) 243 244 245static int 246prepare_for_payload (struct lsquic_frame_reader *fr) 247{ 248 uint32_t stream_id; 249 unsigned char *header_block; 250 251 /* RFC 7540, Section 4.1: Ignore R bit: */ 252 fr->fr_state.header.hfh_stream_id[0] &= ~0x80; 253 254 fr->fr_state.payload_length = hfh_get_length(&fr->fr_state.header); 255 256 stream_id = fr_get_stream_id(fr); 257 258 if (fr->fr_state.header.hfh_type != HTTP_FRAME_CONTINUATION && 259 (fr->fr_flags & FRF_HAVE_PREV) && 260 (fr->fr_prev_frame_type == HTTP_FRAME_HEADERS || 261 fr->fr_prev_frame_type == HTTP_FRAME_PUSH_PROMISE || 262 fr->fr_prev_frame_type == HTTP_FRAME_CONTINUATION ) && 263 0 == (fr->fr_prev_hfh_flags & HFHF_END_HEADERS)) 264 { 265 LSQ_INFO("Framing error: expected CONTINUATION frame, got %u", 266 fr->fr_state.header.hfh_type); 267 fr->fr_callbacks->frc_on_error(fr->fr_cb_ctx, stream_id, 268 FR_ERR_EXPECTED_CONTIN); 269 return -1; 270 } 271 272 switch (fr->fr_state.header.hfh_type) 273 { 274 case HTTP_FRAME_HEADERS: 275 if (fr->fr_max_headers_sz && 276 fr->fr_state.payload_length > fr->fr_max_headers_sz) 277 goto headers_too_large; 278 fr->fr_state.by_type.headers_state.frame_type = HTTP_FRAME_HEADERS; 279 fr->fr_state.by_type.headers_state.nread = 0; 280 fr->fr_state.by_type.headers_state.pesw_nread = 0; 281 fr->fr_state.by_type.headers_state.pseh = 0; 282 if (fr->fr_state.header.hfh_flags & HFHF_PADDED) 283 fr->fr_state.by_type.headers_state.pesw_size = 1; 284 else 285 { 286 fr->fr_state.by_type.headers_state.pad_length = 0; 287 fr->fr_state.by_type.headers_state.pesw_size = 0; 288 } 289 if (fr->fr_state.header.hfh_flags & HFHF_PRIORITY) 290 fr->fr_state.by_type.headers_state.pesw_size += 5; 291 else 292 { 293 fr->fr_state.by_type.headers_state.exclusive = -1; 294 fr->fr_state.by_type.headers_state.oth_stream_id = 0; 295 fr->fr_state.by_type.headers_state.weight = 0; 296 } 297 LSQ_DEBUG("pesw size: %u; payload length: %u; flags: 0x%X", 298 fr->fr_state.by_type.headers_state.pesw_size, 299 fr->fr_state.payload_length, fr->fr_state.header.hfh_flags); 300 if (fr->fr_state.by_type.headers_state.pesw_size > 301 fr->fr_state.payload_length) 302 { 303 LSQ_INFO("Invalid headers frame: payload length too small"); 304 errno = EBADMSG; 305 return -1; 306 } 307 fr->fr_state.reader_type = READER_HEADERS; 308 break; 309 case HTTP_FRAME_PUSH_PROMISE: 310 if (fr->fr_flags & FRF_SERVER) 311 { 312 LSQ_INFO("clients should not push promised"); 313 fr->fr_callbacks->frc_on_error(fr->fr_cb_ctx, stream_id, 314 FR_ERR_UNEXPECTED_PUSH); 315 return -1; 316 } 317 if (fr->fr_max_headers_sz && 318 fr->fr_state.payload_length > fr->fr_max_headers_sz) 319 goto headers_too_large; 320 fr->fr_state.by_type.headers_state.frame_type = HTTP_FRAME_PUSH_PROMISE; 321 fr->fr_state.by_type.headers_state.nread = 0; 322 fr->fr_state.by_type.headers_state.pesw_nread = 0; 323 fr->fr_state.by_type.headers_state.pseh = 0; 324 if (fr->fr_state.header.hfh_flags & HFHF_PADDED) 325 fr->fr_state.by_type.headers_state.pesw_size = 5; 326 else 327 { 328 fr->fr_state.by_type.headers_state.pad_length = 0; 329 fr->fr_state.by_type.headers_state.pesw_size = 4; 330 } 331 LSQ_DEBUG("pesw size: %u; payload length: %u; flags: 0x%X", 332 fr->fr_state.by_type.headers_state.pesw_size, 333 fr->fr_state.payload_length, fr->fr_state.header.hfh_flags); 334 if (fr->fr_state.by_type.headers_state.pesw_size > 335 fr->fr_state.payload_length) 336 { 337 LSQ_INFO("Invalid headers frame: payload length too small"); 338 errno = EBADMSG; 339 return -1; 340 } 341 fr->fr_state.reader_type = READER_PUSH_PROMISE; 342 break; 343 case HTTP_FRAME_CONTINUATION: 344 if (0 == (fr->fr_flags & FRF_HAVE_PREV)) 345 { 346 LSQ_INFO("Framing error: unexpected CONTINUATION"); 347 return -1; 348 } 349 if (!(fr->fr_prev_frame_type == HTTP_FRAME_HEADERS || 350 fr->fr_prev_frame_type == HTTP_FRAME_PUSH_PROMISE || 351 fr->fr_prev_frame_type == HTTP_FRAME_CONTINUATION)) 352 { 353 LSQ_INFO("Framing error: unexpected CONTINUATION"); 354 return -1; 355 } 356 if (fr->fr_prev_hfh_flags & HFHF_END_HEADERS) 357 { 358 LSQ_INFO("Framing error: unexpected CONTINUATION"); 359 return -1; 360 } 361 if (stream_id != fr->fr_prev_stream_id) 362 { 363 LSQ_INFO("Framing error: CONTINUATION does not have matching " 364 "stream ID"); 365 return -1; 366 } 367 if (fr->fr_state.reader_type == READER_SKIP) 368 goto continue_skipping; 369 fr->fr_header_block_sz += fr->fr_state.payload_length; 370 if (fr->fr_max_headers_sz && 371 fr->fr_header_block_sz > fr->fr_max_headers_sz) 372 { 373 free(fr->fr_header_block); 374 fr->fr_header_block = NULL; 375 goto headers_too_large; 376 } 377 header_block = realloc(fr->fr_header_block, fr->fr_header_block_sz); 378 if (!header_block) 379 { 380 LSQ_WARN("cannot allocate %u bytes for header block", 381 fr->fr_header_block_sz); 382 fr->fr_callbacks->frc_on_error(fr->fr_cb_ctx, stream_id, 383 FR_ERR_NOMEM); 384 return -1; 385 } 386 fr->fr_header_block = header_block; 387 fr->fr_state.by_type.headers_state.nread = 0; 388 fr->fr_state.reader_type = READER_CONTIN; 389 break; 390 case HTTP_FRAME_SETTINGS: 391 if (0 == fr->fr_state.payload_length || 392 0 != fr->fr_state.payload_length % 6) 393 { 394 LSQ_INFO("Framing error: %u is not a valid SETTINGS length", 395 fr->fr_state.payload_length); 396 fr->fr_callbacks->frc_on_error(fr->fr_cb_ctx, stream_id, 397 FR_ERR_INVALID_FRAME_SIZE); 398 return -1; 399 } 400 if (stream_id) 401 { /* RFC 7540, Section 6.5 */ 402 LSQ_INFO("Error: SETTINGS frame should not have stream ID set"); 403 fr->fr_callbacks->frc_on_error(fr->fr_cb_ctx, stream_id, 404 FR_ERR_NONZERO_STREAM_ID); 405 return -1; 406 } 407 fr->fr_state.by_type.settings_state.nread = 0; 408 fr->fr_state.reader_type = READER_SETTINGS; 409 break; 410 case HTTP_FRAME_PRIORITY: 411 if (fr->fr_state.payload_length != sizeof(struct http_prio_frame)) 412 { 413 LSQ_INFO("Framing error: %u is not a valid PRIORITY length", 414 fr->fr_state.payload_length); 415 fr->fr_callbacks->frc_on_error(fr->fr_cb_ctx, stream_id, 416 FR_ERR_INVALID_FRAME_SIZE); 417 return -1; 418 } 419 if (!stream_id) 420 { /* RFC 7540, Section 6.3 */ 421 LSQ_INFO("Error: PRIORITY frame must have stream ID set"); 422 fr->fr_callbacks->frc_on_error(fr->fr_cb_ctx, stream_id, 423 FR_ERR_ZERO_STREAM_ID); 424 return -1; 425 } 426 fr->fr_state.by_type.settings_state.nread = 0; 427 fr->fr_state.reader_type = READER_PRIORITY; 428 break; 429 headers_too_large: 430 LSQ_INFO("headers are too large (%u bytes), skipping", 431 fr->fr_state.payload_length); 432 fr->fr_callbacks->frc_on_error(fr->fr_cb_ctx, stream_id, 433 FR_ERR_HEADERS_TOO_LARGE); 434 /* fallthru */ 435 continue_skipping: 436 default: 437 fr->fr_state.by_type.skip_state.n_skipped = 0; 438 fr->fr_state.reader_type = READER_SKIP; 439 break; 440 } 441 442 fr->fr_flags |= FRF_HAVE_PREV; 443 fr->fr_prev_frame_type = fr->fr_state.header.hfh_type; 444 fr->fr_prev_hfh_flags = fr->fr_state.header.hfh_flags; 445 fr->fr_prev_stream_id = stream_id; 446 447 return 0; 448} 449 450 451static int 452read_http_frame_header (struct lsquic_frame_reader *fr) 453{ 454 ssize_t nr; 455 size_t ntoread; 456 unsigned char *dst; 457 458 ntoread = sizeof(fr->fr_state.header) - fr->fr_state.nh_read; 459 dst = (unsigned char *) &fr->fr_state.header + fr->fr_state.nh_read; 460 nr = fr->fr_read(fr->fr_stream, dst, ntoread); 461 if (nr <= 0) 462 RETURN_ERROR(nr); 463 fr->fr_state.nh_read += nr; 464 if (fr->fr_state.nh_read == sizeof(fr->fr_state.header)) 465 { 466 LSQ_DEBUG("read in frame %s", hft_to_string(fr->fr_state.header.hfh_type)); 467 return prepare_for_payload(fr); 468 } 469 else 470 return 0; 471} 472 473 474static int 475skip_payload (struct lsquic_frame_reader *fr) 476{ 477 struct skip_state *ss = &fr->fr_state.by_type.skip_state; 478 size_t ntoread = fr->fr_state.payload_length - ss->n_skipped; 479 unsigned char buf[0x100]; 480 if (ntoread > sizeof(buf)) 481 ntoread = sizeof(buf); 482 ssize_t nr = fr->fr_read(fr->fr_stream, buf, ntoread); 483 if (nr <= 0) 484 RETURN_ERROR(nr); 485 ss->n_skipped += nr; 486 if (ss->n_skipped == fr->fr_state.payload_length) 487 reset_state(fr); 488 return 0; 489} 490 491 492static int 493skip_headers_padding (struct lsquic_frame_reader *fr) 494{ 495 unsigned char buf[0x100]; 496 struct headers_state *hs = &fr->fr_state.by_type.headers_state; 497 unsigned pay_and_pad_length = fr->fr_state.payload_length - hs->pesw_size; 498 unsigned ntoread = pay_and_pad_length - hs->nread; 499 assert(ntoread <= sizeof(buf)); 500 if (ntoread > sizeof(buf)) 501 ntoread = sizeof(buf); 502 ssize_t nr = fr->fr_read(fr->fr_stream, buf, ntoread); 503 if (nr <= 0) 504 RETURN_ERROR(nr); 505 hs->nread += nr; 506 if (hs->nread == pay_and_pad_length) 507 reset_state(fr); 508 return 0; 509} 510 511 512static int 513decode_and_pass_payload (struct lsquic_frame_reader *fr) 514{ 515 struct headers_state *hs = &fr->fr_state.by_type.headers_state; 516 const unsigned char *comp, *end; 517 enum frame_reader_error err; 518 int s; 519 uint32_t name_idx; 520 lshpack_strlen_t name_len, val_len; 521 char *buf; 522 uint32_t stream_id32; 523 struct uncompressed_headers *uh = NULL; 524 void *hset = NULL; 525 526 buf = lsquic_mm_get_16k(fr->fr_mm); 527 if (!buf) 528 { 529 err = FR_ERR_NOMEM; 530 goto stream_error; 531 } 532 533 hset = fr->fr_hsi_if->hsi_create_header_set(fr->fr_hsi_ctx, 534 READER_PUSH_PROMISE == fr->fr_state.reader_type); 535 if (!hset) 536 { 537 err = FR_ERR_NOMEM; 538 goto stream_error; 539 } 540 541 comp = fr->fr_header_block; 542 end = comp + fr->fr_header_block_sz; 543 544 while (comp < end) 545 { 546 s = lshpack_dec_decode(fr->fr_hdec, &comp, end, 547 buf, buf + 16 * 1024, &name_len, &val_len, &name_idx); 548 if (s == 0) 549 { 550 if (name_idx > 61 /* XXX 61 */) 551 name_idx = 0; /* Work around bug in ls-hpack */ 552 err = (enum frame_reader_error) 553 fr->fr_hsi_if->hsi_process_header(hset, name_idx, buf, 554 name_len, buf + name_len, val_len); 555 if (err == 0) 556 { 557#if LSQUIC_CONN_STATS 558 fr->fr_conn_stats->in.headers_uncomp += name_len + val_len; 559#endif 560 continue; 561 } 562 } 563 else 564 err = FR_ERR_DECOMPRESS; 565 goto stream_error; 566 } 567 assert(comp == end); 568 lsquic_mm_put_16k(fr->fr_mm, buf); 569 buf = NULL; 570 571 err = (enum frame_reader_error) 572 fr->fr_hsi_if->hsi_process_header(hset, 0, 0, 0, 0, 0); 573 if (err) 574 goto stream_error; 575 576 uh = calloc(1, sizeof(*uh)); 577 if (!uh) 578 { 579 err = FR_ERR_NOMEM; 580 goto stream_error; 581 } 582 583 memcpy(&stream_id32, fr->fr_state.header.hfh_stream_id, 584 sizeof(stream_id32)); 585 uh->uh_stream_id = ntohl(stream_id32); 586 uh->uh_oth_stream_id = hs->oth_stream_id; 587 if (HTTP_FRAME_HEADERS == fr->fr_state.by_type.headers_state.frame_type) 588 { 589 uh->uh_weight = hs->weight; 590 uh->uh_exclusive = hs->exclusive; 591 uh->uh_flags = 0; 592 } 593 else 594 { 595 assert(HTTP_FRAME_PUSH_PROMISE == 596 fr->fr_state.by_type.headers_state.frame_type); 597 uh->uh_weight = 0; /* Zero unused value */ 598 uh->uh_exclusive = 0; /* Zero unused value */ 599 uh->uh_flags = UH_PP; 600 } 601 if (fr->fr_state.header.hfh_flags & HFHF_END_STREAM) 602 uh->uh_flags |= UH_FIN; 603 if (fr->fr_hsi_if == lsquic_http1x_if) 604 uh->uh_flags |= UH_H1H; 605 uh->uh_hset = hset; 606 607 EV_LOG_HTTP_HEADERS_IN(LSQUIC_LOG_CONN_ID, fr->fr_flags & FRF_SERVER, uh); 608 if (HTTP_FRAME_HEADERS == fr->fr_state.by_type.headers_state.frame_type) 609 fr->fr_callbacks->frc_on_headers(fr->fr_cb_ctx, uh); 610 else 611 fr->fr_callbacks->frc_on_push_promise(fr->fr_cb_ctx, uh); 612#if LSQUIC_CONN_STATS 613 fr->fr_conn_stats->in.headers_comp += fr->fr_header_block_sz; 614#endif 615 616 return 0; 617 618 stream_error: 619 LSQ_INFO("%s: stream error %u", __func__, err); 620 if (hset) 621 fr->fr_hsi_if->hsi_discard_header_set(hset); 622 if (buf) 623 lsquic_mm_put_16k(fr->fr_mm, buf); 624 fr->fr_callbacks->frc_on_error(fr->fr_cb_ctx, fr_get_stream_id(fr), err); 625 return 0; 626} 627 628 629static int 630read_headers_block_fragment (struct lsquic_frame_reader *fr) 631{ 632 struct headers_state *hs = &fr->fr_state.by_type.headers_state; 633 ssize_t nr; 634 unsigned payload_length = fr->fr_state.payload_length - hs->pesw_size - 635 hs->pad_length; 636 if (!fr->fr_header_block) 637 { 638 fr->fr_header_block_sz = payload_length; 639 fr->fr_header_block = malloc(payload_length); 640 if (!fr->fr_header_block) 641 return -1; 642 } 643 nr = fr->fr_read(fr->fr_stream, fr->fr_header_block + hs->nread, 644 fr->fr_header_block_sz - hs->nread); 645 if (nr <= 0) 646 { 647 free(fr->fr_header_block); 648 fr->fr_header_block = NULL; 649 RETURN_ERROR(nr); 650 } 651 hs->nread += nr; 652 if (hs->nread == payload_length && 653 (fr->fr_state.header.hfh_flags & HFHF_END_HEADERS)) 654 { 655 int rv = decode_and_pass_payload(fr); 656 free(fr->fr_header_block); 657 fr->fr_header_block = NULL; 658 return rv; 659 } 660 else 661 return 0; 662} 663 664 665static int 666read_headers_block_fragment_and_padding (struct lsquic_frame_reader *fr) 667{ 668 struct headers_state *hs = &fr->fr_state.by_type.headers_state; 669 unsigned payload_length = fr->fr_state.payload_length - hs->pesw_size; 670 int rv; 671 if (hs->nread < payload_length - hs->pad_length) 672 rv = read_headers_block_fragment(fr); 673 else if (payload_length) 674 rv = skip_headers_padding(fr); 675 else 676 { /* Edge case where PESW takes up the whole frame */ 677 fr->fr_header_block_sz = 0; 678 fr->fr_header_block = NULL; 679 rv = 0; 680 } 681 if (0 == rv && hs->nread == payload_length) 682 reset_state(fr); 683 return rv; 684} 685 686 687static int 688read_headers_pesw (struct lsquic_frame_reader *fr) 689{ 690 struct headers_state *hs = &fr->fr_state.by_type.headers_state; 691 ssize_t nr = fr->fr_read(fr->fr_stream, hs->pesw + hs->pesw_nread, 692 hs->pesw_size - hs->pesw_nread); 693 if (nr <= 0) 694 RETURN_ERROR(nr); 695 hs->pesw_nread += nr; 696 if (hs->pesw_nread == hs->pesw_size) 697 { 698 unsigned char *p = hs->pesw; 699 if (fr->fr_state.header.hfh_flags & HFHF_PADDED) 700 hs->pad_length = *p++; 701 if (fr->fr_state.header.hfh_flags & HFHF_PRIORITY) 702 { 703 hs->exclusive = p[0] >> 7; 704 p[0] &= ~0x80; /* Note that we are modifying pesw buffer. */ 705 memcpy(&hs->oth_stream_id, p, sizeof(hs->oth_stream_id)); 706 hs->oth_stream_id = ntohl(hs->oth_stream_id); 707 p += 4; 708 hs->weight = 1 + *p++; 709 } 710 assert(p - hs->pesw == hs->pesw_size); 711 712 if (hs->pesw_size + hs->pad_length > fr->fr_state.payload_length) 713 { 714 LSQ_INFO("Invalid headers frame: pesw length and padding length " 715 "are larger than the payload length"); 716 errno = EBADMSG; 717 return -1; 718 } 719 } 720 return 0; 721} 722 723 724static int 725read_headers (struct lsquic_frame_reader *fr) 726{ 727 struct headers_state *hs = &fr->fr_state.by_type.headers_state; 728 if (hs->pesw_nread < hs->pesw_size) 729 return read_headers_pesw(fr); 730 else 731 return read_headers_block_fragment_and_padding(fr); 732} 733 734 735static int 736read_push_promise_pesw (struct lsquic_frame_reader *fr) 737{ 738 struct headers_state *hs = &fr->fr_state.by_type.headers_state; 739 ssize_t nr = fr->fr_read(fr->fr_stream, hs->pesw + hs->pesw_nread, 740 hs->pesw_size - hs->pesw_nread); 741 if (nr <= 0) 742 RETURN_ERROR(nr); 743 hs->pesw_nread += nr; 744 if (hs->pesw_nread == hs->pesw_size) 745 { 746 unsigned char *p = hs->pesw; 747 if (fr->fr_state.header.hfh_flags & HFHF_PADDED) 748 hs->pad_length = *p++; 749 p[0] &= ~0x80; /* Clear reserved bit. Note: modifying pesw buffer. */ 750 memcpy(&hs->oth_stream_id, p, sizeof(hs->oth_stream_id)); 751 hs->oth_stream_id = ntohl(hs->oth_stream_id); 752 p += 4; 753 assert(p - hs->pesw == hs->pesw_size); 754 if (hs->pesw_size + hs->pad_length > fr->fr_state.payload_length) 755 { 756 LSQ_INFO("Invalid PUSH_PROMISE frame: pesw length and padding length " 757 "are larger than the payload length"); 758 errno = EBADMSG; 759 return -1; 760 } 761 } 762 return 0; 763} 764 765 766static int 767read_push_promise (struct lsquic_frame_reader *fr) 768{ 769 struct headers_state *hs = &fr->fr_state.by_type.headers_state; 770 if (hs->pesw_nread < hs->pesw_size) 771 return read_push_promise_pesw(fr); 772 else 773 return read_headers_block_fragment_and_padding(fr); 774} 775 776 777static int 778read_contin (struct lsquic_frame_reader *fr) 779{ 780 struct headers_state *hs = &fr->fr_state.by_type.headers_state; 781 unsigned ntoread; 782 ssize_t nr; 783 784 ntoread = fr->fr_state.payload_length - hs->nread; 785 nr = fr->fr_read(fr->fr_stream, 786 fr->fr_header_block + fr->fr_header_block_sz - ntoread, 787 ntoread); 788 if (nr <= 0) 789 RETURN_ERROR(nr); 790 hs->nread += nr; 791 if (hs->nread == fr->fr_state.payload_length) 792 { 793 if (fr->fr_state.header.hfh_flags & HFHF_END_HEADERS) 794 { 795 int rv = decode_and_pass_payload(fr); 796 free(fr->fr_header_block); 797 fr->fr_header_block = NULL; 798 reset_state(fr); 799 return rv; 800 } 801 else 802 { 803 reset_state(fr); 804 return 0; 805 } 806 } 807 else 808 return 0; 809} 810 811 812static int 813read_settings (struct lsquic_frame_reader *fr) 814{ 815 struct settings_state *ss = &fr->fr_state.by_type.settings_state; 816 unsigned ntoread; 817 ssize_t nr; 818 uint32_t setting_value; 819 uint16_t setting_id; 820 821 ntoread = sizeof(ss->set_buf) - ss->nread; 822 nr = fr->fr_read(fr->fr_stream, ss->set_buf + ss->nread, ntoread); 823 if (nr <= 0) 824 RETURN_ERROR(nr); 825 ss->nread += nr; 826 if (ss->nread == sizeof(ss->set_buf)) 827 { 828 memcpy(&setting_id, ss->set_buf, 2); 829 memcpy(&setting_value, ss->set_buf + 2, 4); 830 setting_id = ntohs(setting_id); 831 setting_value = ntohl(setting_value); 832 EV_LOG_CONN_EVENT(LSQUIC_LOG_CONN_ID, "read HTTP SETTING %s=%"PRIu32, 833 lsquic_http_setting_id2str(setting_id), setting_value); 834 fr->fr_callbacks->frc_on_settings(fr->fr_cb_ctx, setting_id, 835 setting_value); 836 837 fr->fr_state.payload_length -= sizeof(ss->set_buf); 838 if (0 == fr->fr_state.payload_length) 839 reset_state(fr); 840 else 841 ss->nread = 0; 842 } 843 return 0; 844} 845 846 847static int 848read_priority (struct lsquic_frame_reader *fr) 849{ 850 struct priority_state *ps = &fr->fr_state.by_type.priority_state; 851 unsigned ntoread; 852 ssize_t nr; 853 uint32_t stream_id, dep_stream_id; 854 int exclusive; 855 856 ntoread = sizeof(ps->u.prio_buf) - ps->nread; 857 nr = fr->fr_read(fr->fr_stream, ps->u.prio_buf + ps->nread, ntoread); 858 if (nr <= 0) 859 RETURN_ERROR(nr); 860 ps->nread += nr; 861 if (ps->nread == sizeof(ps->u.prio_buf)) 862 { 863 memcpy(&dep_stream_id, ps->u.prio_frame.hpf_stream_id, 4); 864 dep_stream_id = ntohl(dep_stream_id); 865 exclusive = dep_stream_id >> 31; 866 dep_stream_id &= ~(1UL << 31); 867 stream_id = fr_get_stream_id(fr); 868 if (stream_id == dep_stream_id) 869 fr->fr_callbacks->frc_on_error(fr->fr_cb_ctx, stream_id, 870 FR_ERR_SELF_DEP_STREAM); 871 else 872 { 873 EV_LOG_CONN_EVENT(LSQUIC_LOG_CONN_ID, "read PRIORITY frame; " 874 "stream: %"PRIu32", dep stream %"PRIu32", exclusive: %d, " 875 "weight: %u", stream_id, dep_stream_id, exclusive, 876 ps->u.prio_frame.hpf_weight + 1); 877 fr->fr_callbacks->frc_on_priority(fr->fr_cb_ctx, stream_id, 878 exclusive, dep_stream_id, ps->u.prio_frame.hpf_weight + 1); 879 } 880 reset_state(fr); 881 } 882 return 0; 883} 884 885 886static int 887read_payload (struct lsquic_frame_reader *fr) 888{ 889 switch (fr->fr_state.reader_type) 890 { 891 case READER_HEADERS: 892 return read_headers(fr); 893 case READER_PUSH_PROMISE: 894 return read_push_promise(fr); 895 case READER_CONTIN: 896 return read_contin(fr); 897 case READER_SETTINGS: 898 return read_settings(fr); 899 case READER_PRIORITY: 900 return read_priority(fr); 901 default: 902 assert(READER_SKIP == fr->fr_state.reader_type); 903 return skip_payload(fr); 904 } 905} 906 907 908int 909lsquic_frame_reader_read (struct lsquic_frame_reader *fr) 910{ 911 if (fr->fr_state.nh_read < sizeof(fr->fr_state.header)) 912 return read_http_frame_header(fr); 913 else 914 return read_payload(fr); 915} 916 917 918size_t 919lsquic_frame_reader_mem_used (const struct lsquic_frame_reader *fr) 920{ 921 size_t size; 922 size = sizeof(*fr); 923 if (fr->fr_header_block) 924 size += fr->fr_header_block_sz; 925 return size; 926} 927