1/* 2 * Copyright (c) 2003-2009 Niels Provos <provos@citi.umich.edu> 3 * Copyright (c) 2009-2012 Niels Provos and Nick Mathewson 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. The name of the author may not be used to endorse or promote products 14 * derived from this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28#include "event2/event-config.h" 29#include "evconfig-private.h" 30 31#ifdef EVENT__HAVE_SYS_TYPES_H 32#include <sys/types.h> 33#endif 34#ifdef EVENT__HAVE_SYS_PARAM_H 35#include <sys/param.h> 36#endif 37 38#ifdef _WIN32 39#define WIN32_LEAN_AND_MEAN 40#include <winsock2.h> 41#include <windows.h> 42#undef WIN32_LEAN_AND_MEAN 43#endif 44 45#ifdef EVENT__HAVE_SYS_IOCTL_H 46#include <sys/ioctl.h> 47#endif 48#include <sys/queue.h> 49#ifdef EVENT__HAVE_SYS_TIME_H 50#include <sys/time.h> 51#endif 52 53#include <errno.h> 54#include <stdio.h> 55#include <stdlib.h> 56#include <string.h> 57#ifndef _WIN32 58#include <syslog.h> 59#endif 60#ifdef EVENT__HAVE_UNISTD_H 61#include <unistd.h> 62#endif 63#include <limits.h> 64 65#include "event2/event.h" 66#include "event2/tag.h" 67#include "event2/buffer.h" 68#include "log-internal.h" 69#include "mm-internal.h" 70#include "util-internal.h" 71 72/* 73 Here's our wire format: 74 75 Stream = TaggedData* 76 77 TaggedData = Tag Length Data 78 where the integer value of 'Length' is the length of 'data'. 79 80 Tag = HByte* LByte 81 where HByte is a byte with the high bit set, and LByte is a byte 82 with the high bit clear. The integer value of the tag is taken 83 by concatenating the lower 7 bits from all the tags. So for example, 84 the tag 0x66 is encoded as [66], whereas the tag 0x166 is encoded as 85 [82 66] 86 87 Length = Integer 88 89 Integer = NNibbles Nibble* Padding? 90 where NNibbles is a 4-bit value encoding the number of nibbles-1, 91 and each Nibble is 4 bits worth of encoded integer, in big-endian 92 order. If the total encoded integer size is an odd number of nibbles, 93 a final padding nibble with value 0 is appended. 94*/ 95 96EVENT2_EXPORT_SYMBOL 97int evtag_decode_int(ev_uint32_t *pnumber, struct evbuffer *evbuf); 98EVENT2_EXPORT_SYMBOL 99int evtag_decode_int64(ev_uint64_t *pnumber, struct evbuffer *evbuf); 100EVENT2_EXPORT_SYMBOL 101int evtag_encode_tag(struct evbuffer *evbuf, ev_uint32_t tag); 102EVENT2_EXPORT_SYMBOL 103int evtag_decode_tag(ev_uint32_t *ptag, struct evbuffer *evbuf); 104 105void 106evtag_init(void) 107{ 108} 109 110/* 111 * We encode integers by nibbles; the first nibble contains the number 112 * of significant nibbles - 1; this allows us to encode up to 64-bit 113 * integers. This function is byte-order independent. 114 * 115 * @param number a 32-bit unsigned integer to encode 116 * @param data a pointer to where the data should be written. Must 117 * have at least 5 bytes free. 118 * @return the number of bytes written into data. 119 */ 120 121#define ENCODE_INT_INTERNAL(data, number) do { \ 122 int off = 1, nibbles = 0; \ 123 \ 124 memset(data, 0, sizeof(number)+1); \ 125 while (number) { \ 126 if (off & 0x1) \ 127 data[off/2] = (data[off/2] & 0xf0) | (number & 0x0f); \ 128 else \ 129 data[off/2] = (data[off/2] & 0x0f) | \ 130 ((number & 0x0f) << 4); \ 131 number >>= 4; \ 132 off++; \ 133 } \ 134 \ 135 if (off > 2) \ 136 nibbles = off - 2; \ 137 \ 138 /* Off - 1 is the number of encoded nibbles */ \ 139 data[0] = (data[0] & 0x0f) | ((nibbles & 0x0f) << 4); \ 140 \ 141 return ((off + 1) / 2); \ 142} while (0) 143 144static inline int 145encode_int_internal(ev_uint8_t *data, ev_uint32_t number) 146{ 147 ENCODE_INT_INTERNAL(data, number); 148} 149 150static inline int 151encode_int64_internal(ev_uint8_t *data, ev_uint64_t number) 152{ 153 ENCODE_INT_INTERNAL(data, number); 154} 155 156void 157evtag_encode_int(struct evbuffer *evbuf, ev_uint32_t number) 158{ 159 ev_uint8_t data[5]; 160 int len = encode_int_internal(data, number); 161 evbuffer_add(evbuf, data, len); 162} 163 164void 165evtag_encode_int64(struct evbuffer *evbuf, ev_uint64_t number) 166{ 167 ev_uint8_t data[9]; 168 int len = encode_int64_internal(data, number); 169 evbuffer_add(evbuf, data, len); 170} 171 172/* 173 * Support variable length encoding of tags; we use the high bit in each 174 * octet as a continuation signal. 175 */ 176 177int 178evtag_encode_tag(struct evbuffer *evbuf, ev_uint32_t tag) 179{ 180 int bytes = 0; 181 ev_uint8_t data[5]; 182 183 memset(data, 0, sizeof(data)); 184 do { 185 ev_uint8_t lower = tag & 0x7f; 186 tag >>= 7; 187 188 if (tag) 189 lower |= 0x80; 190 191 data[bytes++] = lower; 192 } while (tag); 193 194 if (evbuf != NULL) 195 evbuffer_add(evbuf, data, bytes); 196 197 return (bytes); 198} 199 200static int 201decode_tag_internal(ev_uint32_t *ptag, struct evbuffer *evbuf, int dodrain) 202{ 203 ev_uint32_t number = 0; 204 size_t len = evbuffer_get_length(evbuf); 205 ev_uint8_t *data; 206 size_t count = 0; 207 int shift = 0, done = 0; 208 209 /* 210 * the encoding of a number is at most one byte more than its 211 * storage size. however, it may also be much smaller. 212 */ 213 data = evbuffer_pullup( 214 evbuf, len < sizeof(number) + 1 ? len : sizeof(number) + 1); 215 if (!data) 216 return (-1); 217 218 while (count++ < len) { 219 ev_uint8_t lower = *data++; 220 if (shift >= 28) { 221 /* Make sure it fits into 32 bits */ 222 if (shift > 28) 223 return (-1); 224 if ((lower & 0x7f) > 15) 225 return (-1); 226 } 227 number |= (lower & (unsigned)0x7f) << shift; 228 shift += 7; 229 230 if (!(lower & 0x80)) { 231 done = 1; 232 break; 233 } 234 } 235 236 if (!done) 237 return (-1); 238 239 if (dodrain) 240 evbuffer_drain(evbuf, count); 241 242 if (ptag != NULL) 243 *ptag = number; 244 245 return count > INT_MAX ? INT_MAX : (int)(count); 246} 247 248int 249evtag_decode_tag(ev_uint32_t *ptag, struct evbuffer *evbuf) 250{ 251 return (decode_tag_internal(ptag, evbuf, 1 /* dodrain */)); 252} 253 254/* 255 * Marshal a data type, the general format is as follows: 256 * 257 * tag number: one byte; length: var bytes; payload: var bytes 258 */ 259 260void 261evtag_marshal(struct evbuffer *evbuf, ev_uint32_t tag, 262 const void *data, ev_uint32_t len) 263{ 264 evtag_encode_tag(evbuf, tag); 265 evtag_encode_int(evbuf, len); 266 evbuffer_add(evbuf, (void *)data, len); 267} 268 269void 270evtag_marshal_buffer(struct evbuffer *evbuf, ev_uint32_t tag, 271 struct evbuffer *data) 272{ 273 evtag_encode_tag(evbuf, tag); 274 /* XXX support more than UINT32_MAX data */ 275 evtag_encode_int(evbuf, (ev_uint32_t)evbuffer_get_length(data)); 276 evbuffer_add_buffer(evbuf, data); 277} 278 279/* Marshaling for integers */ 280void 281evtag_marshal_int(struct evbuffer *evbuf, ev_uint32_t tag, ev_uint32_t integer) 282{ 283 ev_uint8_t data[5]; 284 int len = encode_int_internal(data, integer); 285 286 evtag_encode_tag(evbuf, tag); 287 evtag_encode_int(evbuf, len); 288 evbuffer_add(evbuf, data, len); 289} 290 291void 292evtag_marshal_int64(struct evbuffer *evbuf, ev_uint32_t tag, 293 ev_uint64_t integer) 294{ 295 ev_uint8_t data[9]; 296 int len = encode_int64_internal(data, integer); 297 298 evtag_encode_tag(evbuf, tag); 299 evtag_encode_int(evbuf, len); 300 evbuffer_add(evbuf, data, len); 301} 302 303void 304evtag_marshal_string(struct evbuffer *buf, ev_uint32_t tag, const char *string) 305{ 306 /* TODO support strings longer than UINT32_MAX ? */ 307 evtag_marshal(buf, tag, string, (ev_uint32_t)strlen(string)); 308} 309 310void 311evtag_marshal_timeval(struct evbuffer *evbuf, ev_uint32_t tag, struct timeval *tv) 312{ 313 ev_uint8_t data[10]; 314 int len = encode_int_internal(data, tv->tv_sec); 315 len += encode_int_internal(data + len, tv->tv_usec); 316 evtag_marshal(evbuf, tag, data, len); 317} 318 319#define DECODE_INT_INTERNAL(number, maxnibbles, pnumber, evbuf, offset) \ 320do { \ 321 ev_uint8_t *data; \ 322 ev_ssize_t len = evbuffer_get_length(evbuf) - offset; \ 323 int nibbles = 0; \ 324 \ 325 if (len <= 0) \ 326 return (-1); \ 327 \ 328 /* XXX(niels): faster? */ \ 329 data = evbuffer_pullup(evbuf, offset + 1) + offset; \ 330 if (!data) \ 331 return (-1); \ 332 \ 333 nibbles = ((data[0] & 0xf0) >> 4) + 1; \ 334 if (nibbles > maxnibbles || (nibbles >> 1) + 1 > len) \ 335 return (-1); \ 336 len = (nibbles >> 1) + 1; \ 337 \ 338 data = evbuffer_pullup(evbuf, offset + len) + offset; \ 339 if (!data) \ 340 return (-1); \ 341 \ 342 while (nibbles > 0) { \ 343 number <<= 4; \ 344 if (nibbles & 0x1) \ 345 number |= data[nibbles >> 1] & 0x0f; \ 346 else \ 347 number |= (data[nibbles >> 1] & 0xf0) >> 4; \ 348 nibbles--; \ 349 } \ 350 \ 351 *pnumber = number; \ 352 \ 353 return (int)(len); \ 354} while (0) 355 356/* Internal: decode an integer from an evbuffer, without draining it. 357 * Only integers up to 32-bits are supported. 358 * 359 * @param evbuf the buffer to read from 360 * @param offset an index into the buffer at which we should start reading. 361 * @param pnumber a pointer to receive the integer. 362 * @return The length of the number as encoded, or -1 on error. 363 */ 364 365static int 366decode_int_internal(ev_uint32_t *pnumber, struct evbuffer *evbuf, int offset) 367{ 368 ev_uint32_t number = 0; 369 DECODE_INT_INTERNAL(number, 8, pnumber, evbuf, offset); 370} 371 372static int 373decode_int64_internal(ev_uint64_t *pnumber, struct evbuffer *evbuf, int offset) 374{ 375 ev_uint64_t number = 0; 376 DECODE_INT_INTERNAL(number, 16, pnumber, evbuf, offset); 377} 378 379int 380evtag_decode_int(ev_uint32_t *pnumber, struct evbuffer *evbuf) 381{ 382 int res = decode_int_internal(pnumber, evbuf, 0); 383 if (res != -1) 384 evbuffer_drain(evbuf, res); 385 386 return (res == -1 ? -1 : 0); 387} 388 389int 390evtag_decode_int64(ev_uint64_t *pnumber, struct evbuffer *evbuf) 391{ 392 int res = decode_int64_internal(pnumber, evbuf, 0); 393 if (res != -1) 394 evbuffer_drain(evbuf, res); 395 396 return (res == -1 ? -1 : 0); 397} 398 399int 400evtag_peek(struct evbuffer *evbuf, ev_uint32_t *ptag) 401{ 402 return (decode_tag_internal(ptag, evbuf, 0 /* dodrain */)); 403} 404 405int 406evtag_peek_length(struct evbuffer *evbuf, ev_uint32_t *plength) 407{ 408 int res, len; 409 410 len = decode_tag_internal(NULL, evbuf, 0 /* dodrain */); 411 if (len == -1) 412 return (-1); 413 414 res = decode_int_internal(plength, evbuf, len); 415 if (res == -1) 416 return (-1); 417 418 *plength += res + len; 419 420 return (0); 421} 422 423int 424evtag_payload_length(struct evbuffer *evbuf, ev_uint32_t *plength) 425{ 426 int res, len; 427 428 len = decode_tag_internal(NULL, evbuf, 0 /* dodrain */); 429 if (len == -1) 430 return (-1); 431 432 res = decode_int_internal(plength, evbuf, len); 433 if (res == -1) 434 return (-1); 435 436 return (0); 437} 438 439/* just unmarshals the header and returns the length of the remaining data */ 440 441int 442evtag_unmarshal_header(struct evbuffer *evbuf, ev_uint32_t *ptag) 443{ 444 ev_uint32_t len; 445 446 if (decode_tag_internal(ptag, evbuf, 1 /* dodrain */) == -1) 447 return (-1); 448 if (evtag_decode_int(&len, evbuf) == -1) 449 return (-1); 450 451 if (evbuffer_get_length(evbuf) < len) 452 return (-1); 453 454 return (len); 455} 456 457int 458evtag_consume(struct evbuffer *evbuf) 459{ 460 int len; 461 if ((len = evtag_unmarshal_header(evbuf, NULL)) == -1) 462 return (-1); 463 evbuffer_drain(evbuf, len); 464 465 return (0); 466} 467 468/* Reads the data type from an event buffer */ 469 470int 471evtag_unmarshal(struct evbuffer *src, ev_uint32_t *ptag, struct evbuffer *dst) 472{ 473 int len; 474 475 if ((len = evtag_unmarshal_header(src, ptag)) == -1) 476 return (-1); 477 478 if (evbuffer_add(dst, evbuffer_pullup(src, len), len) == -1) 479 return (-1); 480 481 evbuffer_drain(src, len); 482 483 return (len); 484} 485 486/* Marshaling for integers */ 487 488int 489evtag_unmarshal_int(struct evbuffer *evbuf, ev_uint32_t need_tag, 490 ev_uint32_t *pinteger) 491{ 492 ev_uint32_t tag; 493 ev_uint32_t len; 494 int result; 495 496 if (decode_tag_internal(&tag, evbuf, 1 /* dodrain */) == -1) 497 return (-1); 498 if (need_tag != tag) 499 return (-1); 500 if (evtag_decode_int(&len, evbuf) == -1) 501 return (-1); 502 503 if (evbuffer_get_length(evbuf) < len) 504 return (-1); 505 506 result = decode_int_internal(pinteger, evbuf, 0); 507 evbuffer_drain(evbuf, len); 508 if (result < 0 || (size_t)result > len) /* XXX Should this be != rather than > ?*/ 509 return (-1); 510 else 511 return result; 512} 513 514int 515evtag_unmarshal_int64(struct evbuffer *evbuf, ev_uint32_t need_tag, 516 ev_uint64_t *pinteger) 517{ 518 ev_uint32_t tag; 519 ev_uint32_t len; 520 int result; 521 522 if (decode_tag_internal(&tag, evbuf, 1 /* dodrain */) == -1) 523 return (-1); 524 if (need_tag != tag) 525 return (-1); 526 if (evtag_decode_int(&len, evbuf) == -1) 527 return (-1); 528 529 if (evbuffer_get_length(evbuf) < len) 530 return (-1); 531 532 result = decode_int64_internal(pinteger, evbuf, 0); 533 evbuffer_drain(evbuf, len); 534 if (result < 0 || (size_t)result > len) /* XXX Should this be != rather than > ?*/ 535 return (-1); 536 else 537 return result; 538} 539 540/* Unmarshal a fixed length tag */ 541 542int 543evtag_unmarshal_fixed(struct evbuffer *src, ev_uint32_t need_tag, void *data, 544 size_t len) 545{ 546 ev_uint32_t tag; 547 int tag_len; 548 549 /* Now unmarshal a tag and check that it matches the tag we want */ 550 if ((tag_len = evtag_unmarshal_header(src, &tag)) < 0 || 551 tag != need_tag) 552 return (-1); 553 554 if ((size_t)tag_len != len) 555 return (-1); 556 557 evbuffer_remove(src, data, len); 558 return (0); 559} 560 561int 562evtag_unmarshal_string(struct evbuffer *evbuf, ev_uint32_t need_tag, 563 char **pstring) 564{ 565 ev_uint32_t tag; 566 int tag_len; 567 568 if ((tag_len = evtag_unmarshal_header(evbuf, &tag)) == -1 || 569 tag != need_tag) 570 return (-1); 571 572 *pstring = mm_malloc(tag_len + 1); 573 if (*pstring == NULL) { 574 event_warn("%s: malloc", __func__); 575 return -1; 576 } 577 evbuffer_remove(evbuf, *pstring, tag_len); 578 (*pstring)[tag_len] = '\0'; 579 580 return (0); 581} 582 583int 584evtag_unmarshal_timeval(struct evbuffer *evbuf, ev_uint32_t need_tag, 585 struct timeval *ptv) 586{ 587 ev_uint32_t tag; 588 ev_uint32_t integer; 589 int len, offset, offset2; 590 int result = -1; 591 592 if ((len = evtag_unmarshal_header(evbuf, &tag)) == -1) 593 return (-1); 594 if (tag != need_tag) 595 goto done; 596 if ((offset = decode_int_internal(&integer, evbuf, 0)) == -1) 597 goto done; 598 ptv->tv_sec = integer; 599 if ((offset2 = decode_int_internal(&integer, evbuf, offset)) == -1) 600 goto done; 601 ptv->tv_usec = integer; 602 if (offset + offset2 > len) /* XXX Should this be != instead of > ? */ 603 goto done; 604 605 result = 0; 606 done: 607 evbuffer_drain(evbuf, len); 608 return result; 609} 610