1 /* 2 * Copyright (c) 2003, 2004 Niels Provos <provos (at) citi.umich.edu> 3 * All rights reserved. 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 #ifdef HAVE_CONFIG_H 29 #include "config.h" 30 #endif 31 32 #ifdef HAVE_SYS_TYPES_H 33 #include <sys/types.h> 34 #endif 35 #ifdef HAVE_SYS_PARAM_H 36 #include <sys/param.h> 37 #endif 38 39 #ifdef WIN32 40 #define WIN32_LEAN_AND_MEAN 41 #include <winsock2.h> 42 #include <windows.h> 43 #undef WIN32_LEAN_AND_MEAN 44 #else 45 #include <sys/ioctl.h> 46 #endif 47 48 #include <sys/queue.h> 49 #ifdef 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 HAVE_UNISTD_H 61 #include <unistd.h> 62 #endif 63 64 #include "event.h" 65 #include "evutil.h" 66 #include "log.h" 67 68 int evtag_decode_int(ev_uint32_t *pnumber, struct evbuffer *evbuf); 69 int evtag_encode_tag(struct evbuffer *evbuf, ev_uint32_t tag); 70 int evtag_decode_tag(ev_uint32_t *ptag, struct evbuffer *evbuf); 71 72 static struct evbuffer *_buf; /* not thread safe */ 73 74 void 75 evtag_init(void) 76 { 77 if (_buf != NULL) 78 return; 79 80 if ((_buf = evbuffer_new()) == NULL) 81 event_err(1, "%s: malloc", __func__); 82 } 83 84 /* 85 * We encode integer's by nibbles; the first nibble contains the number 86 * of significant nibbles - 1; this allows us to encode up to 64-bit 87 * integers. This function is byte-order independent. 88 */ 89 90 void 91 encode_int(struct evbuffer *evbuf, ev_uint32_t number) 92 { 93 int off = 1, nibbles = 0; 94 ev_uint8_t data[5]; 95 96 memset(data, 0, sizeof(ev_uint32_t)+1); 97 while (number) { 98 if (off & 0x1) 99 data[off/2] = (data[off/2] & 0xf0) | (number & 0x0f); 100 else 101 data[off/2] = (data[off/2] & 0x0f) | 102 ((number & 0x0f) << 4); 103 number >>= 4; 104 off++; 105 } 106 107 if (off > 2) 108 nibbles = off - 2; 109 110 /* Off - 1 is the number of encoded nibbles */ 111 data[0] = (data[0] & 0x0f) | ((nibbles & 0x0f) << 4); 112 113 evbuffer_add(evbuf, data, (off + 1) / 2); 114 } 115 116 /* 117 * Support variable length encoding of tags; we use the high bit in each 118 * octet as a continuation signal. 119 */ 120 121 int 122 evtag_encode_tag(struct evbuffer *evbuf, ev_uint32_t tag) 123 { 124 int bytes = 0; 125 ev_uint8_t data[5]; 126 127 memset(data, 0, sizeof(data)); 128 do { 129 ev_uint8_t lower = tag & 0x7f; 130 tag >>= 7; 131 132 if (tag) 133 lower |= 0x80; 134 135 data[bytes++] = lower; 136 } while (tag); 137 138 if (evbuf != NULL) 139 evbuffer_add(evbuf, data, bytes); 140 141 return (bytes); 142 } 143 144 static int 145 decode_tag_internal(ev_uint32_t *ptag, struct evbuffer *evbuf, int dodrain) 146 { 147 ev_uint32_t number = 0; 148 ev_uint8_t *data = EVBUFFER_DATA(evbuf); 149 int len = EVBUFFER_LENGTH(evbuf); 150 int count = 0, shift = 0, done = 0; 151 152 while (count++ < len) { 153 ev_uint8_t lower = *data++; 154 number |= (lower & 0x7f) << shift; 155 shift += 7; 156 157 if (!(lower & 0x80)) { 158 done = 1; 159 break; 160 } 161 } 162 163 if (!done) 164 return (-1); 165 166 if (dodrain) 167 evbuffer_drain(evbuf, count); 168 169 if (ptag != NULL) 170 *ptag = number; 171 172 return (count); 173 } 174 175 int 176 evtag_decode_tag(ev_uint32_t *ptag, struct evbuffer *evbuf) 177 { 178 return (decode_tag_internal(ptag, evbuf, 1 /* dodrain */)); 179 } 180 181 /* 182 * Marshal a data type, the general format is as follows: 183 * 184 * tag number: one byte; length: var bytes; payload: var bytes 185 */ 186 187 void 188 evtag_marshal(struct evbuffer *evbuf, ev_uint32_t tag, 189 const void *data, ev_uint32_t len) 190 { 191 evtag_encode_tag(evbuf, tag); 192 encode_int(evbuf, len); 193 evbuffer_add(evbuf, (void *)data, len); 194 } 195 196 /* Marshaling for integers */ 197 void 198 evtag_marshal_int(struct evbuffer *evbuf, ev_uint32_t tag, ev_uint32_t integer) 199 { 200 evbuffer_drain(_buf, EVBUFFER_LENGTH(_buf)); 201 encode_int(_buf, integer); 202 203 evtag_encode_tag(evbuf, tag); 204 encode_int(evbuf, EVBUFFER_LENGTH(_buf)); 205 evbuffer_add_buffer(evbuf, _buf); 206 } 207 208 void 209 evtag_marshal_string(struct evbuffer *buf, ev_uint32_t tag, const char *string) 210 { 211 evtag_marshal(buf, tag, string, strlen(string)); 212 } 213 214 void 215 evtag_marshal_timeval(struct evbuffer *evbuf, ev_uint32_t tag, struct timeval *tv) 216 { 217 evbuffer_drain(_buf, EVBUFFER_LENGTH(_buf)); 218 219 encode_int(_buf, tv->tv_sec); 220 encode_int(_buf, tv->tv_usec); 221 222 evtag_marshal(evbuf, tag, EVBUFFER_DATA(_buf), 223 EVBUFFER_LENGTH(_buf)); 224 } 225 226 static int 227 decode_int_internal(ev_uint32_t *pnumber, struct evbuffer *evbuf, int dodrain) 228 { 229 ev_uint32_t number = 0; 230 ev_uint8_t *data = EVBUFFER_DATA(evbuf); 231 int len = EVBUFFER_LENGTH(evbuf); 232 int nibbles = 0; 233 234 if (!len) 235 return (-1); 236 237 nibbles = ((data[0] & 0xf0) >> 4) + 1; 238 if (nibbles > 8 || (nibbles >> 1) + 1 > len) 239 return (-1); 240 len = (nibbles >> 1) + 1; 241 242 while (nibbles > 0) { 243 number <<= 4; 244 if (nibbles & 0x1) 245 number |= data[nibbles >> 1] & 0x0f; 246 else 247 number |= (data[nibbles >> 1] & 0xf0) >> 4; 248 nibbles--; 249 } 250 251 if (dodrain) 252 evbuffer_drain(evbuf, len); 253 254 *pnumber = number; 255 256 return (len); 257 } 258 259 int 260 evtag_decode_int(ev_uint32_t *pnumber, struct evbuffer *evbuf) 261 { 262 return (decode_int_internal(pnumber, evbuf, 1) == -1 ? -1 : 0); 263 } 264 265 int 266 evtag_peek(struct evbuffer *evbuf, ev_uint32_t *ptag) 267 { 268 return (decode_tag_internal(ptag, evbuf, 0 /* dodrain */)); 269 } 270 271 int 272 evtag_peek_length(struct evbuffer *evbuf, ev_uint32_t *plength) 273 { 274 struct evbuffer tmp; 275 int res, len; 276 277 len = decode_tag_internal(NULL, evbuf, 0 /* dodrain */); 278 if (len == -1) 279 return (-1); 280 281 tmp = *evbuf; 282 tmp.buffer += len; 283 tmp.off -= len; 284 285 res = decode_int_internal(plength, &tmp, 0); 286 if (res == -1) 287 return (-1); 288 289 *plength += res + len; 290 291 return (0); 292 } 293 294 int 295 evtag_payload_length(struct evbuffer *evbuf, ev_uint32_t *plength) 296 { 297 struct evbuffer tmp; 298 int res, len; 299 300 len = decode_tag_internal(NULL, evbuf, 0 /* dodrain */); 301 if (len == -1) 302 return (-1); 303 304 tmp = *evbuf; 305 tmp.buffer += len; 306 tmp.off -= len; 307 308 res = decode_int_internal(plength, &tmp, 0); 309 if (res == -1) 310 return (-1); 311 312 return (0); 313 } 314 315 int 316 evtag_consume(struct evbuffer *evbuf) 317 { 318 ev_uint32_t len; 319 if (decode_tag_internal(NULL, evbuf, 1 /* dodrain */) == -1) 320 return (-1); 321 if (evtag_decode_int(&len, evbuf) == -1) 322 return (-1); 323 evbuffer_drain(evbuf, len); 324 325 return (0); 326 } 327 328 /* Reads the data type from an event buffer */ 329 330 int 331 evtag_unmarshal(struct evbuffer *src, ev_uint32_t *ptag, struct evbuffer *dst) 332 { 333 ev_uint32_t len; 334 ev_uint32_t integer; 335 336 if (decode_tag_internal(ptag, src, 1 /* dodrain */) == -1) 337 return (-1); 338 if (evtag_decode_int(&integer, src) == -1) 339 return (-1); 340 len = integer; 341 342 if (EVBUFFER_LENGTH(src) < len) 343 return (-1); 344 345 if (evbuffer_add(dst, EVBUFFER_DATA(src), len) == -1) 346 return (-1); 347 348 evbuffer_drain(src, len); 349 350 return (len); 351 } 352 353 /* Marshaling for integers */ 354 355 int 356 evtag_unmarshal_int(struct evbuffer *evbuf, ev_uint32_t need_tag, 357 ev_uint32_t *pinteger) 358 { 359 ev_uint32_t tag; 360 ev_uint32_t len; 361 ev_uint32_t integer; 362 363 if (decode_tag_internal(&tag, evbuf, 1 /* dodrain */) == -1) 364 return (-1); 365 if (need_tag != tag) 366 return (-1); 367 if (evtag_decode_int(&integer, evbuf) == -1) 368 return (-1); 369 len = integer; 370 371 if (EVBUFFER_LENGTH(evbuf) < len) 372 return (-1); 373 374 evbuffer_drain(_buf, EVBUFFER_LENGTH(_buf)); 375 if (evbuffer_add(_buf, EVBUFFER_DATA(evbuf), len) == -1) 376 return (-1); 377 378 evbuffer_drain(evbuf, len); 379 380 return (evtag_decode_int(pinteger, _buf)); 381 } 382 383 /* Unmarshal a fixed length tag */ 384 385 int 386 evtag_unmarshal_fixed(struct evbuffer *src, ev_uint32_t need_tag, void *data, 387 size_t len) 388 { 389 ev_uint32_t tag; 390 391 /* Initialize this event buffer so that we can read into it */ 392 evbuffer_drain(_buf, EVBUFFER_LENGTH(_buf)); 393 394 /* Now unmarshal a tag and check that it matches the tag we want */ 395 if (evtag_unmarshal(src, &tag, _buf) == -1 || tag != need_tag) 396 return (-1); 397 398 if (EVBUFFER_LENGTH(_buf) != len) 399 return (-1); 400 401 memcpy(data, EVBUFFER_DATA(_buf), len); 402 return (0); 403 } 404 405 int 406 evtag_unmarshal_string(struct evbuffer *evbuf, ev_uint32_t need_tag, 407 char **pstring) 408 { 409 ev_uint32_t tag; 410 411 evbuffer_drain(_buf, EVBUFFER_LENGTH(_buf)); 412 413 if (evtag_unmarshal(evbuf, &tag, _buf) == -1 || tag != need_tag) 414 return (-1); 415 416 *pstring = calloc(EVBUFFER_LENGTH(_buf) + 1, 1); 417 if (*pstring == NULL) 418 event_err(1, "%s: calloc", __func__); 419 evbuffer_remove(_buf, *pstring, EVBUFFER_LENGTH(_buf)); 420 421 return (0); 422 } 423 424 int 425 evtag_unmarshal_timeval(struct evbuffer *evbuf, ev_uint32_t need_tag, 426 struct timeval *ptv) 427 { 428 ev_uint32_t tag; 429 ev_uint32_t integer; 430 431 evbuffer_drain(_buf, EVBUFFER_LENGTH(_buf)); 432 if (evtag_unmarshal(evbuf, &tag, _buf) == -1 || tag != need_tag) 433 return (-1); 434 435 if (evtag_decode_int(&integer, _buf) == -1) 436 return (-1); 437 ptv->tv_sec = integer; 438 if (evtag_decode_int(&integer, _buf) == -1) 439 return (-1); 440 ptv->tv_usec = integer; 441 442 return (0); 443 } 444
