1 /* 2 * Copyright (c) 2003-2009 Niels Provos <provos (at) 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 96 int evtag_decode_int(ev_uint32_t *pnumber, struct evbuffer *evbuf); 97 int evtag_decode_int64(ev_uint64_t *pnumber, struct evbuffer *evbuf); 98 int evtag_encode_tag(struct evbuffer *evbuf, ev_uint32_t tag); 99 int evtag_decode_tag(ev_uint32_t *ptag, struct evbuffer *evbuf); 100 101 void 102 evtag_init(void) 103 { 104 } 105 106 /* 107 * We encode integers by nibbles; the first nibble contains the number 108 * of significant nibbles - 1; this allows us to encode up to 64-bit 109 * integers. This function is byte-order independent. 110 * 111 * @param number a 32-bit unsigned integer to encode 112 * @param data a pointer to where the data should be written. Must 113 * have at least 5 bytes free. 114 * @return the number of bytes written into data. 115 */ 116 117 #define ENCODE_INT_INTERNAL(data, number) do { \ 118 int off = 1, nibbles = 0; \ 119 \ 120 memset(data, 0, sizeof(number)+1); \ 121 while (number) { \ 122 if (off & 0x1) \ 123 data[off/2] = (data[off/2] & 0xf0) | (number & 0x0f); \ 124 else \ 125 data[off/2] = (data[off/2] & 0x0f) | \ 126 ((number & 0x0f) << 4); \ 127 number >>= 4; \ 128 off++; \ 129 } \ 130 \ 131 if (off > 2) \ 132 nibbles = off - 2; \ 133 \ 134 /* Off - 1 is the number of encoded nibbles */ \ 135 data[0] = (data[0] & 0x0f) | ((nibbles & 0x0f) << 4); \ 136 \ 137 return ((off + 1) / 2); \ 138 } while (0) 139 140 static inline int 141 encode_int_internal(ev_uint8_t *data, ev_uint32_t number) 142 { 143 ENCODE_INT_INTERNAL(data, number); 144 } 145 146 static inline int 147 encode_int64_internal(ev_uint8_t *data, ev_uint64_t number) 148 { 149 ENCODE_INT_INTERNAL(data, number); 150 } 151 152 void 153 evtag_encode_int(struct evbuffer *evbuf, ev_uint32_t number) 154 { 155 ev_uint8_t data[5]; 156 int len = encode_int_internal(data, number); 157 evbuffer_add(evbuf, data, len); 158 } 159 160 void 161 evtag_encode_int64(struct evbuffer *evbuf, ev_uint64_t number) 162 { 163 ev_uint8_t data[9]; 164 int len = encode_int64_internal(data, number); 165 evbuffer_add(evbuf, data, len); 166 } 167 168 /* 169 * Support variable length encoding of tags; we use the high bit in each 170 * octet as a continuation signal. 171 */ 172 173 int 174 evtag_encode_tag(struct evbuffer *evbuf, ev_uint32_t tag) 175 { 176 int bytes = 0; 177 ev_uint8_t data[5]; 178 179 memset(data, 0, sizeof(data)); 180 do { 181 ev_uint8_t lower = tag & 0x7f; 182 tag >>= 7; 183 184 if (tag) 185 lower |= 0x80; 186 187 data[bytes++] = lower; 188 } while (tag); 189 190 if (evbuf != NULL) 191 evbuffer_add(evbuf, data, bytes); 192 193 return (bytes); 194 } 195 196 static int 197 decode_tag_internal(ev_uint32_t *ptag, struct evbuffer *evbuf, int dodrain) 198 { 199 ev_uint32_t number = 0; 200 size_t len = evbuffer_get_length(evbuf); 201 ev_uint8_t *data; 202 size_t count = 0; 203 int shift = 0, done = 0; 204 205 /* 206 * the encoding of a number is at most one byte more than its 207 * storage size. however, it may also be much smaller. 208 */ 209 data = evbuffer_pullup( 210 evbuf, len < sizeof(number) + 1 ? len : sizeof(number) + 1); 211 if (!data) 212 return (-1); 213 214 while (count++ < len) { 215 ev_uint8_t lower = *data++; 216 if (shift >= 28) { 217 /* Make sure it fits into 32 bits */ 218 if (shift > 28) 219 return (-1); 220 if ((lower & 0x7f) > 15) 221 return (-1); 222 } 223 number |= (lower & (unsigned)0x7f) << shift; 224 shift += 7; 225 226 if (!(lower & 0x80)) { 227 done = 1; 228 break; 229 } 230 } 231 232 if (!done) 233 return (-1); 234 235 if (dodrain) 236 evbuffer_drain(evbuf, count); 237 238 if (ptag != NULL) 239 *ptag = number; 240 241 return count > INT_MAX ? INT_MAX : (int)(count); 242 } 243 244 int 245 evtag_decode_tag(ev_uint32_t *ptag, struct evbuffer *evbuf) 246 { 247 return (decode_tag_internal(ptag, evbuf, 1 /* dodrain */)); 248 } 249 250 /* 251 * Marshal a data type, the general format is as follows: 252 * 253 * tag number: one byte; length: var bytes; payload: var bytes 254 */ 255 256 void 257 evtag_marshal(struct evbuffer *evbuf, ev_uint32_t tag, 258 const void *data, ev_uint32_t len) 259 { 260 evtag_encode_tag(evbuf, tag); 261 evtag_encode_int(evbuf, len); 262 evbuffer_add(evbuf, (void *)data, len); 263 } 264 265 void 266 evtag_marshal_buffer(struct evbuffer *evbuf, ev_uint32_t tag, 267 struct evbuffer *data) 268 { 269 evtag_encode_tag(evbuf, tag); 270 /* XXX support more than UINT32_MAX data */ 271 evtag_encode_int(evbuf, (ev_uint32_t)evbuffer_get_length(data)); 272 evbuffer_add_buffer(evbuf, data); 273 } 274 275 /* Marshaling for integers */ 276 void 277 evtag_marshal_int(struct evbuffer *evbuf, ev_uint32_t tag, ev_uint32_t integer) 278 { 279 ev_uint8_t data[5]; 280 int len = encode_int_internal(data, integer); 281 282 evtag_encode_tag(evbuf, tag); 283 evtag_encode_int(evbuf, len); 284 evbuffer_add(evbuf, data, len); 285 } 286 287 void 288 evtag_marshal_int64(struct evbuffer *evbuf, ev_uint32_t tag, 289 ev_uint64_t integer) 290 { 291 ev_uint8_t data[9]; 292 int len = encode_int64_internal(data, integer); 293 294 evtag_encode_tag(evbuf, tag); 295 evtag_encode_int(evbuf, len); 296 evbuffer_add(evbuf, data, len); 297 } 298 299 void 300 evtag_marshal_string(struct evbuffer *buf, ev_uint32_t tag, const char *string) 301 { 302 /* TODO support strings longer than UINT32_MAX ? */ 303 evtag_marshal(buf, tag, string, (ev_uint32_t)strlen(string)); 304 } 305 306 void 307 evtag_marshal_timeval(struct evbuffer *evbuf, ev_uint32_t tag, struct timeval *tv) 308 { 309 ev_uint8_t data[10]; 310 int len = encode_int_internal(data, tv->tv_sec); 311 len += encode_int_internal(data + len, tv->tv_usec); 312 evtag_marshal(evbuf, tag, data, len); 313 } 314 315 #define DECODE_INT_INTERNAL(number, maxnibbles, pnumber, evbuf, offset) \ 316 do { \ 317 ev_uint8_t *data; \ 318 ev_ssize_t len = evbuffer_get_length(evbuf) - offset; \ 319 int nibbles = 0; \ 320 \ 321 if (len <= 0) \ 322 return (-1); \ 323 \ 324 /* XXX(niels): faster? */ \ 325 data = evbuffer_pullup(evbuf, offset + 1) + offset; \ 326 if (!data) \ 327 return (-1); \ 328 \ 329 nibbles = ((data[0] & 0xf0) >> 4) + 1; \ 330 if (nibbles > maxnibbles || (nibbles >> 1) + 1 > len) \ 331 return (-1); \ 332 len = (nibbles >> 1) + 1; \ 333 \ 334 data = evbuffer_pullup(evbuf, offset + len) + offset; \ 335 if (!data) \ 336 return (-1); \ 337 \ 338 while (nibbles > 0) { \ 339 number <<= 4; \ 340 if (nibbles & 0x1) \ 341 number |= data[nibbles >> 1] & 0x0f; \ 342 else \ 343 number |= (data[nibbles >> 1] & 0xf0) >> 4; \ 344 nibbles--; \ 345 } \ 346 \ 347 *pnumber = number; \ 348 \ 349 return (int)(len); \ 350 } while (0) 351 352 /* Internal: decode an integer from an evbuffer, without draining it. 353 * Only integers up to 32-bits are supported. 354 * 355 * @param evbuf the buffer to read from 356 * @param offset an index into the buffer at which we should start reading. 357 * @param pnumber a pointer to receive the integer. 358 * @return The length of the number as encoded, or -1 on error. 359 */ 360 361 static int 362 decode_int_internal(ev_uint32_t *pnumber, struct evbuffer *evbuf, int offset) 363 { 364 ev_uint32_t number = 0; 365 DECODE_INT_INTERNAL(number, 8, pnumber, evbuf, offset); 366 } 367 368 static int 369 decode_int64_internal(ev_uint64_t *pnumber, struct evbuffer *evbuf, int offset) 370 { 371 ev_uint64_t number = 0; 372 DECODE_INT_INTERNAL(number, 16, pnumber, evbuf, offset); 373 } 374 375 int 376 evtag_decode_int(ev_uint32_t *pnumber, struct evbuffer *evbuf) 377 { 378 int res = decode_int_internal(pnumber, evbuf, 0); 379 if (res != -1) 380 evbuffer_drain(evbuf, res); 381 382 return (res == -1 ? -1 : 0); 383 } 384 385 int 386 evtag_decode_int64(ev_uint64_t *pnumber, struct evbuffer *evbuf) 387 { 388 int res = decode_int64_internal(pnumber, evbuf, 0); 389 if (res != -1) 390 evbuffer_drain(evbuf, res); 391 392 return (res == -1 ? -1 : 0); 393 } 394 395 int 396 evtag_peek(struct evbuffer *evbuf, ev_uint32_t *ptag) 397 { 398 return (decode_tag_internal(ptag, evbuf, 0 /* dodrain */)); 399 } 400 401 int 402 evtag_peek_length(struct evbuffer *evbuf, ev_uint32_t *plength) 403 { 404 int res, len; 405 406 len = decode_tag_internal(NULL, evbuf, 0 /* dodrain */); 407 if (len == -1) 408 return (-1); 409 410 res = decode_int_internal(plength, evbuf, len); 411 if (res == -1) 412 return (-1); 413 414 *plength += res + len; 415 416 return (0); 417 } 418 419 int 420 evtag_payload_length(struct evbuffer *evbuf, ev_uint32_t *plength) 421 { 422 int res, len; 423 424 len = decode_tag_internal(NULL, evbuf, 0 /* dodrain */); 425 if (len == -1) 426 return (-1); 427 428 res = decode_int_internal(plength, evbuf, len); 429 if (res == -1) 430 return (-1); 431 432 return (0); 433 } 434 435 /* just unmarshals the header and returns the length of the remaining data */ 436 437 int 438 evtag_unmarshal_header(struct evbuffer *evbuf, ev_uint32_t *ptag) 439 { 440 ev_uint32_t len; 441 442 if (decode_tag_internal(ptag, evbuf, 1 /* dodrain */) == -1) 443 return (-1); 444 if (evtag_decode_int(&len, evbuf) == -1) 445 return (-1); 446 447 if (evbuffer_get_length(evbuf) < len) 448 return (-1); 449 450 return (len); 451 } 452 453 int 454 evtag_consume(struct evbuffer *evbuf) 455 { 456 int len; 457 if ((len = evtag_unmarshal_header(evbuf, NULL)) == -1) 458 return (-1); 459 evbuffer_drain(evbuf, len); 460 461 return (0); 462 } 463 464 /* Reads the data type from an event buffer */ 465 466 int 467 evtag_unmarshal(struct evbuffer *src, ev_uint32_t *ptag, struct evbuffer *dst) 468 { 469 int len; 470 471 if ((len = evtag_unmarshal_header(src, ptag)) == -1) 472 return (-1); 473 474 if (evbuffer_add(dst, evbuffer_pullup(src, len), len) == -1) 475 return (-1); 476 477 evbuffer_drain(src, len); 478 479 return (len); 480 } 481 482 /* Marshaling for integers */ 483 484 int 485 evtag_unmarshal_int(struct evbuffer *evbuf, ev_uint32_t need_tag, 486 ev_uint32_t *pinteger) 487 { 488 ev_uint32_t tag; 489 ev_uint32_t len; 490 int result; 491 492 if (decode_tag_internal(&tag, evbuf, 1 /* dodrain */) == -1) 493 return (-1); 494 if (need_tag != tag) 495 return (-1); 496 if (evtag_decode_int(&len, evbuf) == -1) 497 return (-1); 498 499 if (evbuffer_get_length(evbuf) < len) 500 return (-1); 501 502 result = decode_int_internal(pinteger, evbuf, 0); 503 evbuffer_drain(evbuf, len); 504 if (result < 0 || (size_t)result > len) /* XXX Should this be != rather than > ?*/ 505 return (-1); 506 else 507 return result; 508 } 509 510 int 511 evtag_unmarshal_int64(struct evbuffer *evbuf, ev_uint32_t need_tag, 512 ev_uint64_t *pinteger) 513 { 514 ev_uint32_t tag; 515 ev_uint32_t len; 516 int result; 517 518 if (decode_tag_internal(&tag, evbuf, 1 /* dodrain */) == -1) 519 return (-1); 520 if (need_tag != tag) 521 return (-1); 522 if (evtag_decode_int(&len, evbuf) == -1) 523 return (-1); 524 525 if (evbuffer_get_length(evbuf) < len) 526 return (-1); 527 528 result = decode_int64_internal(pinteger, evbuf, 0); 529 evbuffer_drain(evbuf, len); 530 if (result < 0 || (size_t)result > len) /* XXX Should this be != rather than > ?*/ 531 return (-1); 532 else 533 return result; 534 } 535 536 /* Unmarshal a fixed length tag */ 537 538 int 539 evtag_unmarshal_fixed(struct evbuffer *src, ev_uint32_t need_tag, void *data, 540 size_t len) 541 { 542 ev_uint32_t tag; 543 int tag_len; 544 545 /* Now unmarshal a tag and check that it matches the tag we want */ 546 if ((tag_len = evtag_unmarshal_header(src, &tag)) < 0 || 547 tag != need_tag) 548 return (-1); 549 550 if ((size_t)tag_len != len) 551 return (-1); 552 553 evbuffer_remove(src, data, len); 554 return (0); 555 } 556 557 int 558 evtag_unmarshal_string(struct evbuffer *evbuf, ev_uint32_t need_tag, 559 char **pstring) 560 { 561 ev_uint32_t tag; 562 int tag_len; 563 564 if ((tag_len = evtag_unmarshal_header(evbuf, &tag)) == -1 || 565 tag != need_tag) 566 return (-1); 567 568 *pstring = mm_malloc(tag_len + 1); 569 if (*pstring == NULL) { 570 event_warn("%s: malloc", __func__); 571 return -1; 572 } 573 evbuffer_remove(evbuf, *pstring, tag_len); 574 (*pstring)[tag_len] = '\0'; 575 576 return (0); 577 } 578 579 int 580 evtag_unmarshal_timeval(struct evbuffer *evbuf, ev_uint32_t need_tag, 581 struct timeval *ptv) 582 { 583 ev_uint32_t tag; 584 ev_uint32_t integer; 585 int len, offset, offset2; 586 int result = -1; 587 588 if ((len = evtag_unmarshal_header(evbuf, &tag)) == -1) 589 return (-1); 590 if (tag != need_tag) 591 goto done; 592 if ((offset = decode_int_internal(&integer, evbuf, 0)) == -1) 593 goto done; 594 ptv->tv_sec = integer; 595 if ((offset2 = decode_int_internal(&integer, evbuf, offset)) == -1) 596 goto done; 597 ptv->tv_usec = integer; 598 if (offset + offset2 > len) /* XXX Should this be != instead of > ? */ 599 goto done; 600 601 result = 0; 602 done: 603 evbuffer_drain(evbuf, len); 604 return result; 605 } 606
