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 30 #ifdef _EVENT_HAVE_SYS_TYPES_H 31 #include <sys/types.h> 32 #endif 33 #ifdef _EVENT_HAVE_SYS_PARAM_H 34 #include <sys/param.h> 35 #endif 36 37 #ifdef WIN32 38 #define WIN32_LEAN_AND_MEAN 39 #include <winsock2.h> 40 #include <windows.h> 41 #undef WIN32_LEAN_AND_MEAN 42 #else 43 #include <sys/ioctl.h> 44 #endif 45 46 #include <sys/queue.h> 47 #ifdef _EVENT_HAVE_SYS_TIME_H 48 #include <sys/time.h> 49 #endif 50 51 #include <errno.h> 52 #include <stdio.h> 53 #include <stdlib.h> 54 #include <string.h> 55 #ifndef WIN32 56 #include <syslog.h> 57 #endif 58 #ifdef _EVENT_HAVE_UNISTD_H 59 #include <unistd.h> 60 #endif 61 #include <limits.h> 62 63 #include "event2/event.h" 64 #include "event2/tag.h" 65 #include "event2/buffer.h" 66 #include "log-internal.h" 67 #include "mm-internal.h" 68 #include "util-internal.h" 69 70 /* 71 Here's our wire format: 72 73 Stream = TaggedData* 74 75 TaggedData = Tag Length Data 76 where the integer value of 'Length' is the length of 'data'. 77 78 Tag = HByte* LByte 79 where HByte is a byte with the high bit set, and LByte is a byte 80 with the high bit clear. The integer value of the tag is taken 81 by concatenating the lower 7 bits from all the tags. So for example, 82 the tag 0x66 is encoded as [66], whereas the tag 0x166 is encoded as 83 [82 66] 84 85 Length = Integer 86 87 Integer = NNibbles Nibble* Padding? 88 where NNibbles is a 4-bit value encoding the number of nibbles-1, 89 and each Nibble is 4 bits worth of encoded integer, in big-endian 90 order. If the total encoded integer size is an odd number of nibbles, 91 a final padding nibble with value 0 is appended. 92 */ 93 94 int evtag_decode_int(ev_uint32_t *pnumber, struct evbuffer *evbuf); 95 int evtag_decode_int64(ev_uint64_t *pnumber, struct evbuffer *evbuf); 96 int evtag_encode_tag(struct evbuffer *evbuf, ev_uint32_t tag); 97 int evtag_decode_tag(ev_uint32_t *ptag, struct evbuffer *evbuf); 98 99 void 100 evtag_init(void) 101 { 102 } 103 104 /* 105 * We encode integers by nibbles; the first nibble contains the number 106 * of significant nibbles - 1; this allows us to encode up to 64-bit 107 * integers. This function is byte-order independent. 108 * 109 * @param number a 32-bit unsigned integer to encode 110 * @param data a pointer to where the data should be written. Must 111 * have at least 5 bytes free. 112 * @return the number of bytes written into data. 113 */ 114 115 #define ENCODE_INT_INTERNAL(data, number) do { \ 116 int off = 1, nibbles = 0; \ 117 \ 118 memset(data, 0, sizeof(number)+1); \ 119 while (number) { \ 120 if (off & 0x1) \ 121 data[off/2] = (data[off/2] & 0xf0) | (number & 0x0f); \ 122 else \ 123 data[off/2] = (data[off/2] & 0x0f) | \ 124 ((number & 0x0f) << 4); \ 125 number >>= 4; \ 126 off++; \ 127 } \ 128 \ 129 if (off > 2) \ 130 nibbles = off - 2; \ 131 \ 132 /* Off - 1 is the number of encoded nibbles */ \ 133 data[0] = (data[0] & 0x0f) | ((nibbles & 0x0f) << 4); \ 134 \ 135 return ((off + 1) / 2); \ 136 } while (0) 137 138 static inline int 139 encode_int_internal(ev_uint8_t *data, ev_uint32_t number) 140 { 141 ENCODE_INT_INTERNAL(data, number); 142 } 143 144 static inline int 145 encode_int64_internal(ev_uint8_t *data, ev_uint64_t number) 146 { 147 ENCODE_INT_INTERNAL(data, number); 148 } 149 150 void 151 evtag_encode_int(struct evbuffer *evbuf, ev_uint32_t number) 152 { 153 ev_uint8_t data[5]; 154 int len = encode_int_internal(data, number); 155 evbuffer_add(evbuf, data, len); 156 } 157 158 void 159 evtag_encode_int64(struct evbuffer *evbuf, ev_uint64_t number) 160 { 161 ev_uint8_t data[9]; 162 int len = encode_int64_internal(data, number); 163 evbuffer_add(evbuf, data, len); 164 } 165 166 /* 167 * Support variable length encoding of tags; we use the high bit in each 168 * octet as a continuation signal. 169 */ 170 171 int 172 evtag_encode_tag(struct evbuffer *evbuf, ev_uint32_t tag) 173 { 174 int bytes = 0; 175 ev_uint8_t data[5]; 176 177 memset(data, 0, sizeof(data)); 178 do { 179 ev_uint8_t lower = tag & 0x7f; 180 tag >>= 7; 181 182 if (tag) 183 lower |= 0x80; 184 185 data[bytes++] = lower; 186 } while (tag); 187 188 if (evbuf != NULL) 189 evbuffer_add(evbuf, data, bytes); 190 191 return (bytes); 192 } 193 194 static int 195 decode_tag_internal(ev_uint32_t *ptag, struct evbuffer *evbuf, int dodrain) 196 { 197 ev_uint32_t number = 0; 198 size_t len = evbuffer_get_length(evbuf); 199 ev_uint8_t *data; 200 size_t count = 0; 201 int shift = 0, done = 0; 202 203 /* 204 * the encoding of a number is at most one byte more than its 205 * storage size. however, it may also be much smaller. 206 */ 207 data = evbuffer_pullup( 208 evbuf, len < sizeof(number) + 1 ? len : sizeof(number) + 1); 209 if (!data) 210 return (-1); 211 212 while (count++ < len) { 213 ev_uint8_t lower = *data++; 214 number |= (lower & 0x7f) << shift; 215 shift += 7; 216 217 if (!(lower & 0x80)) { 218 done = 1; 219 break; 220 } 221 } 222 223 if (!done) 224 return (-1); 225 226 if (dodrain) 227 evbuffer_drain(evbuf, count); 228 229 if (ptag != NULL) 230 *ptag = number; 231 232 return count > INT_MAX ? INT_MAX : (int)(count); 233 } 234 235 int 236 evtag_decode_tag(ev_uint32_t *ptag, struct evbuffer *evbuf) 237 { 238 return (decode_tag_internal(ptag, evbuf, 1 /* dodrain */)); 239 } 240 241 /* 242 * Marshal a data type, the general format is as follows: 243 * 244 * tag number: one byte; length: var bytes; payload: var bytes 245 */ 246 247 void 248 evtag_marshal(struct evbuffer *evbuf, ev_uint32_t tag, 249 const void *data, ev_uint32_t len) 250 { 251 evtag_encode_tag(evbuf, tag); 252 evtag_encode_int(evbuf, len); 253 evbuffer_add(evbuf, (void *)data, len); 254 } 255 256 void 257 evtag_marshal_buffer(struct evbuffer *evbuf, ev_uint32_t tag, 258 struct evbuffer *data) 259 { 260 evtag_encode_tag(evbuf, tag); 261 /* XXX support more than UINT32_MAX data */ 262 evtag_encode_int(evbuf, (ev_uint32_t)evbuffer_get_length(data)); 263 evbuffer_add_buffer(evbuf, data); 264 } 265 266 /* Marshaling for integers */ 267 void 268 evtag_marshal_int(struct evbuffer *evbuf, ev_uint32_t tag, ev_uint32_t integer) 269 { 270 ev_uint8_t data[5]; 271 int len = encode_int_internal(data, integer); 272 273 evtag_encode_tag(evbuf, tag); 274 evtag_encode_int(evbuf, len); 275 evbuffer_add(evbuf, data, len); 276 } 277 278 void 279 evtag_marshal_int64(struct evbuffer *evbuf, ev_uint32_t tag, 280 ev_uint64_t integer) 281 { 282 ev_uint8_t data[9]; 283 int len = encode_int64_internal(data, integer); 284 285 evtag_encode_tag(evbuf, tag); 286 evtag_encode_int(evbuf, len); 287 evbuffer_add(evbuf, data, len); 288 } 289 290 void 291 evtag_marshal_string(struct evbuffer *buf, ev_uint32_t tag, const char *string) 292 { 293 /* TODO support strings longer than UINT32_MAX ? */ 294 evtag_marshal(buf, tag, string, (ev_uint32_t)strlen(string)); 295 } 296 297 void 298 evtag_marshal_timeval(struct evbuffer *evbuf, ev_uint32_t tag, struct timeval *tv) 299 { 300 ev_uint8_t data[10]; 301 int len = encode_int_internal(data, tv->tv_sec); 302 len += encode_int_internal(data + len, tv->tv_usec); 303 evtag_marshal(evbuf, tag, data, len); 304 } 305 306 #define DECODE_INT_INTERNAL(number, maxnibbles, pnumber, evbuf, offset) \ 307 do { \ 308 ev_uint8_t *data; \ 309 ev_ssize_t len = evbuffer_get_length(evbuf) - offset; \ 310 int nibbles = 0; \ 311 \ 312 if (len <= 0) \ 313 return (-1); \ 314 \ 315 /* XXX(niels): faster? */ \ 316 data = evbuffer_pullup(evbuf, offset + 1) + offset; \ 317 if (!data) \ 318 return (-1); \ 319 \ 320 nibbles = ((data[0] & 0xf0) >> 4) + 1; \ 321 if (nibbles > maxnibbles || (nibbles >> 1) + 1 > len) \ 322 return (-1); \ 323 len = (nibbles >> 1) + 1; \ 324 \ 325 data = evbuffer_pullup(evbuf, offset + len) + offset; \ 326 if (!data) \ 327 return (-1); \ 328 \ 329 while (nibbles > 0) { \ 330 number <<= 4; \ 331 if (nibbles & 0x1) \ 332 number |= data[nibbles >> 1] & 0x0f; \ 333 else \ 334 number |= (data[nibbles >> 1] & 0xf0) >> 4; \ 335 nibbles--; \ 336 } \ 337 \ 338 *pnumber = number; \ 339 \ 340 return (int)(len); \ 341 } while (0) 342 343 /* Internal: decode an integer from an evbuffer, without draining it. 344 * Only integers up to 32-bits are supported. 345 * 346 * @param evbuf the buffer to read from 347 * @param offset an index into the buffer at which we should start reading. 348 * @param pnumber a pointer to receive the integer. 349 * @return The length of the number as encoded, or -1 on error. 350 */ 351 352 static int 353 decode_int_internal(ev_uint32_t *pnumber, struct evbuffer *evbuf, int offset) 354 { 355 ev_uint32_t number = 0; 356 DECODE_INT_INTERNAL(number, 8, pnumber, evbuf, offset); 357 } 358 359 static int 360 decode_int64_internal(ev_uint64_t *pnumber, struct evbuffer *evbuf, int offset) 361 { 362 ev_uint64_t number = 0; 363 DECODE_INT_INTERNAL(number, 16, pnumber, evbuf, offset); 364 } 365 366 int 367 evtag_decode_int(ev_uint32_t *pnumber, struct evbuffer *evbuf) 368 { 369 int res = decode_int_internal(pnumber, evbuf, 0); 370 if (res != -1) 371 evbuffer_drain(evbuf, res); 372 373 return (res == -1 ? -1 : 0); 374 } 375 376 int 377 evtag_decode_int64(ev_uint64_t *pnumber, struct evbuffer *evbuf) 378 { 379 int res = decode_int64_internal(pnumber, evbuf, 0); 380 if (res != -1) 381 evbuffer_drain(evbuf, res); 382 383 return (res == -1 ? -1 : 0); 384 } 385 386 int 387 evtag_peek(struct evbuffer *evbuf, ev_uint32_t *ptag) 388 { 389 return (decode_tag_internal(ptag, evbuf, 0 /* dodrain */)); 390 } 391 392 int 393 evtag_peek_length(struct evbuffer *evbuf, ev_uint32_t *plength) 394 { 395 int res, len; 396 397 len = decode_tag_internal(NULL, evbuf, 0 /* dodrain */); 398 if (len == -1) 399 return (-1); 400 401 res = decode_int_internal(plength, evbuf, len); 402 if (res == -1) 403 return (-1); 404 405 *plength += res + len; 406 407 return (0); 408 } 409 410 int 411 evtag_payload_length(struct evbuffer *evbuf, ev_uint32_t *plength) 412 { 413 int res, len; 414 415 len = decode_tag_internal(NULL, evbuf, 0 /* dodrain */); 416 if (len == -1) 417 return (-1); 418 419 res = decode_int_internal(plength, evbuf, len); 420 if (res == -1) 421 return (-1); 422 423 return (0); 424 } 425 426 /* just unmarshals the header and returns the length of the remaining data */ 427 428 int 429 evtag_unmarshal_header(struct evbuffer *evbuf, ev_uint32_t *ptag) 430 { 431 ev_uint32_t len; 432 433 if (decode_tag_internal(ptag, evbuf, 1 /* dodrain */) == -1) 434 return (-1); 435 if (evtag_decode_int(&len, evbuf) == -1) 436 return (-1); 437 438 if (evbuffer_get_length(evbuf) < len) 439 return (-1); 440 441 return (len); 442 } 443 444 int 445 evtag_consume(struct evbuffer *evbuf) 446 { 447 int len; 448 if ((len = evtag_unmarshal_header(evbuf, NULL)) == -1) 449 return (-1); 450 evbuffer_drain(evbuf, len); 451 452 return (0); 453 } 454 455 /* Reads the data type from an event buffer */ 456 457 int 458 evtag_unmarshal(struct evbuffer *src, ev_uint32_t *ptag, struct evbuffer *dst) 459 { 460 int len; 461 462 if ((len = evtag_unmarshal_header(src, ptag)) == -1) 463 return (-1); 464 465 if (evbuffer_add(dst, evbuffer_pullup(src, len), len) == -1) 466 return (-1); 467 468 evbuffer_drain(src, len); 469 470 return (len); 471 } 472 473 /* Marshaling for integers */ 474 475 int 476 evtag_unmarshal_int(struct evbuffer *evbuf, ev_uint32_t need_tag, 477 ev_uint32_t *pinteger) 478 { 479 ev_uint32_t tag; 480 ev_uint32_t len; 481 int result; 482 483 if (decode_tag_internal(&tag, evbuf, 1 /* dodrain */) == -1) 484 return (-1); 485 if (need_tag != tag) 486 return (-1); 487 if (evtag_decode_int(&len, evbuf) == -1) 488 return (-1); 489 490 if (evbuffer_get_length(evbuf) < len) 491 return (-1); 492 493 result = decode_int_internal(pinteger, evbuf, 0); 494 evbuffer_drain(evbuf, len); 495 if (result < 0 || (size_t)result > len) /* XXX Should this be != rather than > ?*/ 496 return (-1); 497 else 498 return result; 499 } 500 501 int 502 evtag_unmarshal_int64(struct evbuffer *evbuf, ev_uint32_t need_tag, 503 ev_uint64_t *pinteger) 504 { 505 ev_uint32_t tag; 506 ev_uint32_t len; 507 int result; 508 509 if (decode_tag_internal(&tag, evbuf, 1 /* dodrain */) == -1) 510 return (-1); 511 if (need_tag != tag) 512 return (-1); 513 if (evtag_decode_int(&len, evbuf) == -1) 514 return (-1); 515 516 if (evbuffer_get_length(evbuf) < len) 517 return (-1); 518 519 result = decode_int64_internal(pinteger, evbuf, 0); 520 evbuffer_drain(evbuf, len); 521 if (result < 0 || (size_t)result > len) /* XXX Should this be != rather than > ?*/ 522 return (-1); 523 else 524 return result; 525 } 526 527 /* Unmarshal a fixed length tag */ 528 529 int 530 evtag_unmarshal_fixed(struct evbuffer *src, ev_uint32_t need_tag, void *data, 531 size_t len) 532 { 533 ev_uint32_t tag; 534 int tag_len; 535 536 /* Now unmarshal a tag and check that it matches the tag we want */ 537 if ((tag_len = evtag_unmarshal_header(src, &tag)) < 0 || 538 tag != need_tag) 539 return (-1); 540 541 if ((size_t)tag_len != len) 542 return (-1); 543 544 evbuffer_remove(src, data, len); 545 return (0); 546 } 547 548 int 549 evtag_unmarshal_string(struct evbuffer *evbuf, ev_uint32_t need_tag, 550 char **pstring) 551 { 552 ev_uint32_t tag; 553 int tag_len; 554 555 if ((tag_len = evtag_unmarshal_header(evbuf, &tag)) == -1 || 556 tag != need_tag) 557 return (-1); 558 559 *pstring = mm_malloc(tag_len + 1); 560 if (*pstring == NULL) { 561 event_warn("%s: malloc", __func__); 562 return -1; 563 } 564 evbuffer_remove(evbuf, *pstring, tag_len); 565 (*pstring)[tag_len] = '\0'; 566 567 return (0); 568 } 569 570 int 571 evtag_unmarshal_timeval(struct evbuffer *evbuf, ev_uint32_t need_tag, 572 struct timeval *ptv) 573 { 574 ev_uint32_t tag; 575 ev_uint32_t integer; 576 int len, offset, offset2; 577 int result = -1; 578 579 if ((len = evtag_unmarshal_header(evbuf, &tag)) == -1) 580 return (-1); 581 if (tag != need_tag) 582 goto done; 583 if ((offset = decode_int_internal(&integer, evbuf, 0)) == -1) 584 goto done; 585 ptv->tv_sec = integer; 586 if ((offset2 = decode_int_internal(&integer, evbuf, offset)) == -1) 587 goto done; 588 ptv->tv_usec = integer; 589 if (offset + offset2 > len) /* XXX Should this be != instead of > ? */ 590 goto done; 591 592 result = 0; 593 done: 594 evbuffer_drain(evbuf, len); 595 return result; 596 } 597
