lsquic_qdec_hdl.c revision a137764b
1/* Copyright (c) 2017 - 2019 LiteSpeed Technologies Inc. See LICENSE. */ 2/* 3 * lsquic_qdec_hdl.c -- QPACK decoder streams handler 4 */ 5 6#include <assert.h> 7#include <errno.h> 8#include <inttypes.h> 9#include <stdlib.h> 10#include <string.h> 11#include <sys/queue.h> 12 13#include "lsquic.h" 14#include "lsquic_types.h" 15#include "lsquic_int_types.h" 16#include "lsquic_sfcw.h" 17#include "lsquic_varint.h" 18#include "lsquic_hq.h" 19#include "lsquic_hash.h" 20#include "lsquic_stream.h" 21#include "lsquic_frab_list.h" 22#include "lsqpack.h" 23#include "lsquic_http1x_if.h" 24#include "lsquic_qdec_hdl.h" 25#include "lsquic_mm.h" 26#include "lsquic_engine_public.h" 27#include "lsquic_headers.h" 28#include "lsquic_http1x_if.h" 29#include "lsquic_conn.h" 30 31#define LSQUIC_LOGGER_MODULE LSQLM_QDEC_HDL 32#define LSQUIC_LOG_CONN_ID lsquic_conn_log_cid(qdh->qdh_conn) 33#include "lsquic_logger.h" 34 35static void 36qdh_hblock_unblocked (void *); 37 38 39static int 40qdh_write_decoder (struct qpack_dec_hdl *qdh, const unsigned char *buf, 41 size_t sz) 42{ 43 ssize_t nw; 44 45 if (!(qdh->qdh_dec_sm_out && lsquic_frab_list_empty(&qdh->qdh_fral))) 46 { 47 write_to_frab: 48 if (0 == lsquic_frab_list_write(&qdh->qdh_fral, 49 (unsigned char *) buf, sz)) 50 { 51 LSQ_DEBUG("wrote %zu bytes to frab list", sz); 52 lsquic_stream_wantwrite(qdh->qdh_dec_sm_out, 1); 53 return 0; 54 } 55 else 56 { 57 LSQ_INFO("error writing to frab list"); 58 return -1; 59 } 60 } 61 62 nw = lsquic_stream_write(qdh->qdh_dec_sm_out, buf, sz); 63 if (nw < 0) 64 { 65 LSQ_INFO("error writing to outgoing QPACK decoder stream: %s", 66 strerror(errno)); 67 return -1; 68 } 69 LSQ_DEBUG("wrote %zd bytes to outgoing QPACK decoder stream", nw); 70 71 if ((size_t) nw == sz) 72 return 0; 73 74 buf = buf + nw; 75 sz -= (size_t) nw; 76 goto write_to_frab; 77} 78 79 80static int 81qdh_write_type (struct qpack_dec_hdl *qdh) 82{ 83 int s; 84 85#ifndef NDEBUG 86 const char *env = getenv("LSQUIC_RND_VARINT_LEN"); 87 if (env && atoi(env)) 88 { 89 s = rand() & 3; 90 LSQ_DEBUG("writing %d-byte stream type", 1 << s); 91 } 92 else 93#endif 94 s = 0; 95 96 switch (s) 97 { 98 case 0: 99 return qdh_write_decoder(qdh, 100 (unsigned char []) { HQUST_QPACK_DEC }, 1); 101 case 1: 102 return qdh_write_decoder(qdh, 103 (unsigned char []) { 0x40, HQUST_QPACK_DEC }, 2); 104 case 2: 105 return qdh_write_decoder(qdh, 106 (unsigned char []) { 0x80, 0x00, 0x00, HQUST_QPACK_DEC }, 4); 107 default: 108 return qdh_write_decoder(qdh, 109 (unsigned char []) { 0xC0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 110 HQUST_QPACK_DEC }, 8); 111 } 112} 113 114 115static void 116qdh_begin_out (struct qpack_dec_hdl *qdh) 117{ 118 if (0 != qdh_write_type(qdh)) 119 { 120 LSQ_WARN("%s: could not write to decoder", __func__); 121 qdh->qdh_conn->cn_if->ci_internal_error(qdh->qdh_conn, 122 "cannot write to decoder stream"); 123 } 124} 125 126 127int 128lsquic_qdh_init (struct qpack_dec_hdl *qdh, struct lsquic_conn *conn, 129 int is_server, const struct lsquic_engine_public *enpub, 130 unsigned dyn_table_size, unsigned max_risked_streams) 131{ 132 qdh->qdh_conn = conn; 133 lsquic_frab_list_init(&qdh->qdh_fral, 0x400, NULL, NULL, NULL); 134 lsqpack_dec_init(&qdh->qdh_decoder, (void *) conn, dyn_table_size, 135 max_risked_streams, qdh_hblock_unblocked); 136 qdh->qdh_flags |= QDH_INITIALIZED; 137 qdh->qdh_enpub = enpub; 138 if (qdh->qdh_enpub->enp_hsi_if == lsquic_http1x_if) 139 { 140 qdh->qdh_h1x_ctor_ctx = (struct http1x_ctor_ctx) { 141 .conn = conn, 142 .max_headers_sz = 0x10000, /* XXX */ 143 .is_server = is_server, 144 }; 145 qdh->qdh_hsi_ctx = &qdh->qdh_h1x_ctor_ctx; 146 } 147 else 148 qdh->qdh_hsi_ctx = qdh->qdh_enpub->enp_hsi_ctx; 149 if (qdh->qdh_dec_sm_out) 150 qdh_begin_out(qdh); 151 if (qdh->qdh_enc_sm_in) 152 lsquic_stream_wantread(qdh->qdh_enc_sm_in, 1); 153 LSQ_DEBUG("initialized"); 154 return 0; 155} 156 157 158void 159lsquic_qdh_cleanup (struct qpack_dec_hdl *qdh) 160{ 161 if (qdh->qdh_flags & QDH_INITIALIZED) 162 { 163 LSQ_DEBUG("cleanup"); 164 lsqpack_dec_cleanup(&qdh->qdh_decoder); 165 lsquic_frab_list_cleanup(&qdh->qdh_fral); 166 qdh->qdh_flags &= ~QDH_INITIALIZED; 167 } 168} 169 170static lsquic_stream_ctx_t * 171qdh_out_on_new (void *stream_if_ctx, struct lsquic_stream *stream) 172{ 173 struct qpack_dec_hdl *const qdh = stream_if_ctx; 174 qdh->qdh_dec_sm_out = stream; 175 if (qdh->qdh_flags & QDH_INITIALIZED) 176 qdh_begin_out(qdh); 177 LSQ_DEBUG("initialized outgoing decoder stream"); 178 return (void *) qdh; 179} 180 181 182static void 183qdh_out_on_write (struct lsquic_stream *stream, lsquic_stream_ctx_t *ctx) 184{ 185 struct qpack_dec_hdl *const qdh = (void *) ctx; 186 struct lsquic_reader reader; 187 ssize_t nw; 188 unsigned char buf[LSQPACK_LONGEST_ICI]; 189 190 if (lsqpack_dec_ici_pending(&qdh->qdh_decoder)) 191 { 192 nw = lsqpack_dec_write_ici(&qdh->qdh_decoder, buf, sizeof(buf)); 193 if (nw > 0) 194 { 195 if (0 == qdh_write_decoder(qdh, buf, nw)) 196 LSQ_DEBUG("wrote %zd-byte TSS instruction", nw); 197 else 198 goto err; 199 } 200 else if (nw < 0) 201 { 202 LSQ_WARN("could not generate TSS instruction"); 203 goto err; 204 } 205 } 206 207 if (lsquic_frab_list_empty(&qdh->qdh_fral)) 208 { 209 LSQ_DEBUG("%s: nothing to write", __func__); 210 lsquic_stream_wantwrite(stream, 0); 211 return; 212 } 213 214 reader = (struct lsquic_reader) { 215 .lsqr_read = lsquic_frab_list_read, 216 .lsqr_size = lsquic_frab_list_size, 217 .lsqr_ctx = &qdh->qdh_fral, 218 }; 219 220 nw = lsquic_stream_writef(stream, &reader); 221 if (nw >= 0) 222 { 223 LSQ_DEBUG("wrote %zd bytes to stream", nw); 224 (void) lsquic_stream_flush(stream); 225 if (lsquic_frab_list_empty(&qdh->qdh_fral)) 226 lsquic_stream_wantwrite(stream, 0); 227 } 228 else 229 { 230 LSQ_WARN("cannot write to stream: %s", strerror(errno)); 231 err: 232 lsquic_stream_wantwrite(stream, 0); 233 qdh->qdh_conn->cn_if->ci_internal_error(qdh->qdh_conn, 234 "cannot write to stream"); 235 } 236} 237 238 239static void 240qdh_out_on_close (struct lsquic_stream *stream, lsquic_stream_ctx_t *ctx) 241{ 242 struct qpack_dec_hdl *const qdh = (void *) ctx; 243 qdh->qdh_dec_sm_out = NULL; 244 LSQ_DEBUG("closed outgoing decoder stream"); 245} 246 247 248static void 249qdh_out_on_read (struct lsquic_stream *stream, lsquic_stream_ctx_t *ctx) 250{ 251 assert(0); 252} 253 254 255static const struct lsquic_stream_if qdh_dec_sm_out_if = 256{ 257 .on_new_stream = qdh_out_on_new, 258 .on_read = qdh_out_on_read, 259 .on_write = qdh_out_on_write, 260 .on_close = qdh_out_on_close, 261}; 262const struct lsquic_stream_if *const lsquic_qdh_dec_sm_out_if = 263 &qdh_dec_sm_out_if; 264 265 266static lsquic_stream_ctx_t * 267qdh_in_on_new (void *stream_if_ctx, struct lsquic_stream *stream) 268{ 269 struct qpack_dec_hdl *const qdh = stream_if_ctx; 270 qdh->qdh_enc_sm_in = stream; 271 if (qdh->qdh_flags & QDH_INITIALIZED) 272 lsquic_stream_wantread(qdh->qdh_enc_sm_in, 1); 273 LSQ_DEBUG("initialized incoming encoder stream"); 274 return (void *) qdh; 275} 276 277 278static size_t 279qdh_read_encoder_stream (void *ctx, const unsigned char *buf, size_t sz, 280 int fin) 281{ 282 struct qpack_dec_hdl *const qdh = (void *) ctx; 283 const struct lsqpack_dec_err *qerr; 284 int s; 285 286 if (fin) 287 { 288 LSQ_INFO("encoder stream is closed"); 289 qdh->qdh_conn->cn_if->ci_abort_error(qdh->qdh_conn, 1, 290 HEC_CLOSED_CRITICAL_STREAM, "Peer closed QPACK encoder stream"); 291 goto end; 292 } 293 294 s = lsqpack_dec_enc_in(&qdh->qdh_decoder, buf, sz); 295 if (s != 0) 296 { 297 LSQ_INFO("error reading decoder stream"); 298 qerr = lsqpack_dec_get_err_info(&qdh->qdh_decoder); 299 qdh->qdh_conn->cn_if->ci_abort_error(qdh->qdh_conn, 1, 300 HEC_QPACK_DECODER_STREAM_ERROR, "Error interpreting QPACK encoder " 301 "stream; offset %"PRIu64", line %d", qerr->off, qerr->line); 302 goto end; 303 } 304 if (qdh->qdh_dec_sm_out 305 && lsqpack_dec_ici_pending(&qdh->qdh_decoder)) 306 lsquic_stream_wantwrite(qdh->qdh_dec_sm_out, 1); 307 308 LSQ_DEBUG("successfully fed %zu bytes to QPACK decoder", sz); 309 310 end: 311 return sz; 312} 313 314 315static void 316qdh_in_on_read (struct lsquic_stream *stream, lsquic_stream_ctx_t *ctx) 317{ 318 struct qpack_dec_hdl *const qdh = (void *) ctx; 319 ssize_t nread; 320 321 nread = lsquic_stream_readf(stream, qdh_read_encoder_stream, qdh); 322 if (nread <= 0) 323 { 324 if (nread < 0) 325 { 326 LSQ_WARN("cannot read from encoder stream: %s", strerror(errno)); 327 qdh->qdh_conn->cn_if->ci_internal_error(qdh->qdh_conn, 328 "cannot read from encoder stream"); 329 } 330 else 331 { 332 LSQ_INFO("encoder stream closed by peer: abort connection"); 333 qdh->qdh_conn->cn_if->ci_abort_error(qdh->qdh_conn, 1, 334 HEC_CLOSED_CRITICAL_STREAM, "encoder stream closed"); 335 } 336 lsquic_stream_wantread(stream, 0); 337 } 338} 339 340 341static void 342qdh_in_on_close (struct lsquic_stream *stream, lsquic_stream_ctx_t *ctx) 343{ 344 struct qpack_dec_hdl *const qdh = (void *) ctx; 345 LSQ_DEBUG("closed incoming encoder stream"); 346 qdh->qdh_enc_sm_in = NULL; 347} 348 349 350static void 351qdh_in_on_write (struct lsquic_stream *stream, lsquic_stream_ctx_t *ctx) 352{ 353 assert(0); 354} 355 356 357static const struct lsquic_stream_if qdh_enc_sm_in_if = 358{ 359 .on_new_stream = qdh_in_on_new, 360 .on_read = qdh_in_on_read, 361 .on_write = qdh_in_on_write, 362 .on_close = qdh_in_on_close, 363}; 364const struct lsquic_stream_if *const lsquic_qdh_enc_sm_in_if = 365 &qdh_enc_sm_in_if; 366 367 368static void 369qdh_hblock_unblocked (void *stream_p) 370{ 371 struct lsquic_stream *const stream = stream_p; 372 struct qpack_dec_hdl *const qdh = lsquic_stream_get_qdh(stream); 373 374 LSQ_DEBUG("header block for stream %"PRIu64" unblocked", stream->id); 375 lsquic_stream_qdec_unblocked(stream); 376} 377 378 379static int 380qdh_supply_hset_to_stream (struct qpack_dec_hdl *qdh, 381 struct lsquic_stream *stream, struct lsqpack_header_list *qlist) 382{ 383 const struct lsquic_hset_if *const hset_if = qdh->qdh_enpub->enp_hsi_if; 384 struct uncompressed_headers *uh = NULL; 385 const struct lsqpack_header *header; 386 enum lsquic_header_status st; 387 int push_promise; 388 unsigned i; 389 void *hset; 390 391 push_promise = lsquic_stream_header_is_pp(stream); 392 hset = hset_if->hsi_create_header_set(qdh->qdh_hsi_ctx, push_promise); 393 if (!hset) 394 { 395 LSQ_INFO("call to hsi_create_header_set failed"); 396 return -1; 397 } 398 399 LSQ_DEBUG("got header set for stream %"PRIu64, stream->id); 400 401 for (i = 0; i < qlist->qhl_count; ++i) 402 { 403 header = qlist->qhl_headers[i]; 404 LSQ_DEBUG("%.*s: %.*s", header->qh_name_len, header->qh_name, 405 header->qh_value_len, header->qh_value); 406 st = hset_if->hsi_process_header(hset, 407 header->qh_flags & QH_ID_SET ? 62 /* XXX: 62 */ + header->qh_static_id : 0, 408 header->qh_name, header->qh_name_len, 409 header->qh_value, header->qh_value_len); 410 if (st != LSQUIC_HDR_OK) 411 { 412 LSQ_INFO("header process returned non-OK code %u", (unsigned) st); 413 goto err; 414 } 415 } 416 417 lsqpack_dec_destroy_header_list(qlist); 418 qlist = NULL; 419 st = hset_if->hsi_process_header(hset, 0, 0, 0, 0, 0); 420 if (st != LSQUIC_HDR_OK) 421 goto err; 422 423 uh = calloc(1, sizeof(*uh)); 424 if (!uh) 425 goto err; 426 uh->uh_stream_id = stream->id; 427 uh->uh_oth_stream_id = 0; 428 uh->uh_weight = 0; 429 uh->uh_exclusive = -1; 430 if (hset_if == lsquic_http1x_if) 431 uh->uh_flags |= UH_H1H; 432 uh->uh_hset = hset; 433 if (0 != lsquic_stream_uh_in(stream, uh)) 434 goto err; 435 LSQ_DEBUG("converted qlist to hset and gave it to stream %"PRIu64, 436 stream->id); 437 return 0; 438 439 err: 440 if (qlist) 441 lsqpack_dec_destroy_header_list(qlist); 442 hset_if->hsi_discard_header_set(hset); 443 free(uh); 444 return -1; 445} 446 447 448static int 449qdh_process_qlist (struct qpack_dec_hdl *qdh, 450 struct lsquic_stream *stream, struct lsqpack_header_list *qlist) 451{ 452 if (!lsquic_stream_header_is_trailer(stream)) 453 return qdh_supply_hset_to_stream(qdh, stream, qlist); 454 else 455 { 456 LSQ_DEBUG("discard trailer header set"); 457 lsqpack_dec_destroy_header_list(qlist); 458 return 0; 459 } 460} 461 462 463static enum lsqpack_read_header_status 464qdh_header_read_results (struct qpack_dec_hdl *qdh, 465 struct lsquic_stream *stream, enum lsqpack_read_header_status rhs, 466 struct lsqpack_header_list *qlist, const unsigned char *dec_buf, 467 size_t dec_buf_sz) 468{ 469 const struct lsqpack_dec_err *qerr; 470 471 if (rhs == LQRHS_DONE) 472 { 473 if (qlist) 474 { 475 if (0 != qdh_process_qlist(qdh, stream, qlist)) 476 return LQRHS_ERROR; 477 if (qdh->qdh_dec_sm_out) 478 { 479 if (dec_buf_sz 480 && 0 != qdh_write_decoder(qdh, dec_buf, dec_buf_sz)) 481 { 482 return LQRHS_ERROR; 483 } 484 if (dec_buf_sz || lsqpack_dec_ici_pending(&qdh->qdh_decoder)) 485 lsquic_stream_wantwrite(qdh->qdh_dec_sm_out, 1); 486 } 487 } 488 else 489 { 490 assert(0); /* XXX TODO What do we do here? */ 491 return LQRHS_ERROR; 492 } 493 } 494 else if (rhs == LQRHS_ERROR) 495 { 496 qerr = lsqpack_dec_get_err_info(&qdh->qdh_decoder); 497 qdh->qdh_conn->cn_if->ci_abort_error(qdh->qdh_conn, 1, 498 HEC_QPACK_DECOMPRESSION_FAILED, "QPACK decompression error; " 499 "stream %"PRIu64", offset %"PRIu64", line %d", qerr->stream_id, 500 qerr->off, qerr->line); 501 } 502 503 return rhs; 504} 505 506 507enum lsqpack_read_header_status 508lsquic_qdh_header_in_begin (struct qpack_dec_hdl *qdh, 509 struct lsquic_stream *stream, uint64_t header_size, 510 const unsigned char **buf, size_t bufsz) 511{ 512 enum lsqpack_read_header_status rhs; 513 struct lsqpack_header_list *qlist; 514 size_t dec_buf_sz; 515 unsigned char dec_buf[LSQPACK_LONGEST_HEADER_ACK]; 516 517 if (qdh->qdh_flags & QDH_INITIALIZED) 518 { 519 dec_buf_sz = sizeof(dec_buf); 520 rhs = lsqpack_dec_header_in(&qdh->qdh_decoder, stream, stream->id, 521 header_size, buf, bufsz, &qlist, dec_buf, &dec_buf_sz); 522 return qdh_header_read_results(qdh, stream, rhs, qlist, dec_buf, 523 dec_buf_sz); 524 } 525 else 526 { 527 LSQ_WARN("not initialized: cannot process header block"); 528 return LQRHS_ERROR; 529 } 530 531} 532 533 534enum lsqpack_read_header_status 535lsquic_qdh_header_in_continue (struct qpack_dec_hdl *qdh, 536 struct lsquic_stream *stream, const unsigned char **buf, size_t bufsz) 537{ 538 enum lsqpack_read_header_status rhs; 539 struct lsqpack_header_list *qlist; 540 size_t dec_buf_sz; 541 unsigned char dec_buf[LSQPACK_LONGEST_HEADER_ACK]; 542 543 if (qdh->qdh_flags & QDH_INITIALIZED) 544 { 545 dec_buf_sz = sizeof(dec_buf); 546 rhs = lsqpack_dec_header_read(&qdh->qdh_decoder, stream, 547 buf, bufsz, &qlist, dec_buf, &dec_buf_sz); 548 return qdh_header_read_results(qdh, stream, rhs, qlist, dec_buf, 549 dec_buf_sz); 550 } 551 else 552 { 553 LSQ_WARN("not initialized: cannot process header block"); 554 return LQRHS_ERROR; 555 } 556} 557 558 559void 560lsquic_qdh_unref_stream (struct qpack_dec_hdl *qdh, 561 struct lsquic_stream *stream) 562{ 563 if (0 == lsqpack_dec_unref_stream(&qdh->qdh_decoder, stream)) 564 LSQ_DEBUG("unreffed stream %"PRIu64, stream->id); 565 else 566 LSQ_WARN("cannot unref stream %"PRIu64, stream->id); 567} 568 569 570void 571lsquic_qdh_cancel_stream (struct qpack_dec_hdl *qdh, 572 struct lsquic_stream *stream) 573{ 574 ssize_t nw; 575 unsigned char buf[LSQPACK_LONGEST_CANCEL]; 576 577 nw = lsqpack_dec_cancel_stream(&qdh->qdh_decoder, stream, buf, sizeof(buf)); 578 if (nw > 0) 579 { 580 if (0 == qdh_write_decoder(qdh, buf, nw)) 581 LSQ_DEBUG("cancelled stream %"PRIu64" and wrote %zd-byte Cancel " 582 "Stream instruction to the decoder stream", stream->id, nw); 583 } 584 else if (nw == 0) 585 LSQ_WARN("cannot cancel stream %"PRIu64" -- not found", stream->id); 586 else 587 { 588 LSQ_WARN("cannot cancel stream %"PRIu64" -- not enough buffer space " 589 "to encode Cancel Stream instructin", stream->id); 590 lsquic_qdh_unref_stream(qdh, stream); 591 } 592} 593