San Mehat | ffd6872 | 2010-01-20 09:56:15 -0800 | [diff] [blame] | 1 | /* dnsmasq is Copyright (c) 2000-2009 Simon Kelley |
| 2 | |
| 3 | This program is free software; you can redistribute it and/or modify |
| 4 | it under the terms of the GNU General Public License as published by |
| 5 | the Free Software Foundation; version 2 dated June, 1991, or |
| 6 | (at your option) version 3 dated 29 June, 2007. |
| 7 | |
| 8 | This program is distributed in the hope that it will be useful, |
| 9 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 10 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 11 | GNU General Public License for more details. |
| 12 | |
| 13 | You should have received a copy of the GNU General Public License |
| 14 | along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 15 | */ |
| 16 | |
| 17 | /* The SURF random number generator was taken from djbdns-1.05, by |
| 18 | Daniel J Bernstein, which is public domain. */ |
| 19 | |
| 20 | |
| 21 | #include "dnsmasq.h" |
| 22 | |
| 23 | #ifdef HAVE_BROKEN_RTC |
| 24 | #include <sys/times.h> |
| 25 | #endif |
| 26 | |
| 27 | #ifdef LOCALEDIR |
| 28 | #include <idna.h> |
| 29 | #endif |
| 30 | |
| 31 | #ifdef HAVE_ARC4RANDOM |
| 32 | void rand_init(void) |
| 33 | { |
| 34 | return; |
| 35 | } |
| 36 | |
| 37 | unsigned short rand16(void) |
| 38 | { |
| 39 | return (unsigned short) (arc4random() >> 15); |
| 40 | } |
| 41 | |
| 42 | #else |
| 43 | |
| 44 | /* SURF random number generator */ |
| 45 | |
| 46 | typedef unsigned int uint32; |
| 47 | |
| 48 | static uint32 seed[32]; |
| 49 | static uint32 in[12]; |
| 50 | static uint32 out[8]; |
| 51 | |
| 52 | void rand_init() |
| 53 | { |
| 54 | int fd = open(RANDFILE, O_RDONLY); |
| 55 | |
| 56 | if (fd == -1 || |
| 57 | !read_write(fd, (unsigned char *)&seed, sizeof(seed), 1) || |
| 58 | !read_write(fd, (unsigned char *)&in, sizeof(in), 1)) |
| 59 | die(_("failed to seed the random number generator: %s"), NULL, EC_MISC); |
| 60 | |
| 61 | close(fd); |
| 62 | } |
| 63 | |
| 64 | #define ROTATE(x,b) (((x) << (b)) | ((x) >> (32 - (b)))) |
| 65 | #define MUSH(i,b) x = t[i] += (((x ^ seed[i]) + sum) ^ ROTATE(x,b)); |
| 66 | |
| 67 | static void surf(void) |
| 68 | { |
| 69 | uint32 t[12]; uint32 x; uint32 sum = 0; |
| 70 | int r; int i; int loop; |
| 71 | |
| 72 | for (i = 0;i < 12;++i) t[i] = in[i] ^ seed[12 + i]; |
| 73 | for (i = 0;i < 8;++i) out[i] = seed[24 + i]; |
| 74 | x = t[11]; |
| 75 | for (loop = 0;loop < 2;++loop) { |
| 76 | for (r = 0;r < 16;++r) { |
| 77 | sum += 0x9e3779b9; |
| 78 | MUSH(0,5) MUSH(1,7) MUSH(2,9) MUSH(3,13) |
| 79 | MUSH(4,5) MUSH(5,7) MUSH(6,9) MUSH(7,13) |
| 80 | MUSH(8,5) MUSH(9,7) MUSH(10,9) MUSH(11,13) |
| 81 | } |
| 82 | for (i = 0;i < 8;++i) out[i] ^= t[i + 4]; |
| 83 | } |
| 84 | } |
| 85 | |
| 86 | unsigned short rand16(void) |
| 87 | { |
| 88 | static int outleft = 0; |
| 89 | |
| 90 | if (!outleft) { |
| 91 | if (!++in[0]) if (!++in[1]) if (!++in[2]) ++in[3]; |
| 92 | surf(); |
| 93 | outleft = 8; |
| 94 | } |
| 95 | |
| 96 | return (unsigned short) out[--outleft]; |
| 97 | } |
| 98 | |
| 99 | #endif |
| 100 | |
| 101 | static int check_name(char *in) |
| 102 | { |
| 103 | /* remove trailing . |
| 104 | also fail empty string and label > 63 chars */ |
| 105 | size_t dotgap = 0, l = strlen(in); |
| 106 | char c; |
| 107 | int nowhite = 0; |
| 108 | |
| 109 | if (l == 0 || l > MAXDNAME) return 0; |
| 110 | |
| 111 | if (in[l-1] == '.') |
| 112 | { |
| 113 | if (l == 1) return 0; |
| 114 | in[l-1] = 0; |
| 115 | } |
| 116 | |
| 117 | for (; (c = *in); in++) |
| 118 | { |
| 119 | if (c == '.') |
| 120 | dotgap = 0; |
| 121 | else if (++dotgap > MAXLABEL) |
| 122 | return 0; |
| 123 | else if (isascii(c) && iscntrl(c)) |
| 124 | /* iscntrl only gives expected results for ascii */ |
| 125 | return 0; |
| 126 | #ifndef LOCALEDIR |
| 127 | else if (!isascii(c)) |
| 128 | return 0; |
| 129 | #endif |
| 130 | else if (c != ' ') |
| 131 | nowhite = 1; |
| 132 | } |
| 133 | |
| 134 | if (!nowhite) |
| 135 | return 0; |
| 136 | |
| 137 | return 1; |
| 138 | } |
| 139 | |
| 140 | /* Hostnames have a more limited valid charset than domain names |
| 141 | so check for legal char a-z A-Z 0-9 - _ |
| 142 | Note that this may receive a FQDN, so only check the first label |
| 143 | for the tighter criteria. */ |
| 144 | int legal_hostname(char *name) |
| 145 | { |
| 146 | char c; |
| 147 | |
| 148 | if (!check_name(name)) |
| 149 | return 0; |
| 150 | |
| 151 | for (; (c = *name); name++) |
| 152 | /* check for legal char a-z A-Z 0-9 - _ . */ |
| 153 | { |
| 154 | if ((c >= 'A' && c <= 'Z') || |
| 155 | (c >= 'a' && c <= 'z') || |
| 156 | (c >= '0' && c <= '9') || |
| 157 | c == '-' || c == '_') |
| 158 | continue; |
| 159 | |
| 160 | /* end of hostname part */ |
| 161 | if (c == '.') |
| 162 | return 1; |
| 163 | |
| 164 | return 0; |
| 165 | } |
| 166 | |
| 167 | return 1; |
| 168 | } |
| 169 | |
| 170 | char *canonicalise(char *in, int *nomem) |
| 171 | { |
| 172 | char *ret = NULL; |
| 173 | #ifdef LOCALEDIR |
| 174 | int rc; |
| 175 | #endif |
| 176 | |
| 177 | if (nomem) |
| 178 | *nomem = 0; |
| 179 | |
| 180 | if (!check_name(in)) |
| 181 | return NULL; |
| 182 | |
| 183 | #ifdef LOCALEDIR |
| 184 | if ((rc = idna_to_ascii_lz(in, &ret, 0)) != IDNA_SUCCESS) |
| 185 | { |
| 186 | if (ret) |
| 187 | free(ret); |
| 188 | |
| 189 | if (nomem && (rc == IDNA_MALLOC_ERROR || rc == IDNA_DLOPEN_ERROR)) |
| 190 | { |
| 191 | my_syslog(LOG_ERR, _("failed to allocate memory")); |
| 192 | *nomem = 1; |
| 193 | } |
| 194 | |
| 195 | return NULL; |
| 196 | } |
| 197 | #else |
| 198 | if ((ret = whine_malloc(strlen(in)+1))) |
| 199 | strcpy(ret, in); |
| 200 | else if (nomem) |
| 201 | *nomem = 1; |
| 202 | #endif |
| 203 | |
| 204 | return ret; |
| 205 | } |
| 206 | |
| 207 | unsigned char *do_rfc1035_name(unsigned char *p, char *sval) |
| 208 | { |
| 209 | int j; |
| 210 | |
| 211 | while (sval && *sval) |
| 212 | { |
| 213 | unsigned char *cp = p++; |
| 214 | for (j = 0; *sval && (*sval != '.'); sval++, j++) |
| 215 | *p++ = *sval; |
| 216 | *cp = j; |
| 217 | if (*sval) |
| 218 | sval++; |
| 219 | } |
| 220 | return p; |
| 221 | } |
| 222 | |
| 223 | /* for use during startup */ |
| 224 | void *safe_malloc(size_t size) |
| 225 | { |
| 226 | void *ret = malloc(size); |
| 227 | |
| 228 | if (!ret) |
| 229 | die(_("could not get memory"), NULL, EC_NOMEM); |
| 230 | |
| 231 | return ret; |
| 232 | } |
| 233 | |
| 234 | void safe_pipe(int *fd, int read_noblock) |
| 235 | { |
| 236 | if (pipe(fd) == -1 || |
| 237 | !fix_fd(fd[1]) || |
| 238 | (read_noblock && !fix_fd(fd[0]))) |
| 239 | die(_("cannot create pipe: %s"), NULL, EC_MISC); |
| 240 | } |
| 241 | |
| 242 | void *whine_malloc(size_t size) |
| 243 | { |
| 244 | void *ret = malloc(size); |
| 245 | |
| 246 | if (!ret) |
| 247 | my_syslog(LOG_ERR, _("failed to allocate %d bytes"), (int) size); |
| 248 | |
| 249 | return ret; |
| 250 | } |
| 251 | |
| 252 | int sockaddr_isequal(union mysockaddr *s1, union mysockaddr *s2) |
| 253 | { |
| 254 | if (s1->sa.sa_family == s2->sa.sa_family) |
| 255 | { |
| 256 | if (s1->sa.sa_family == AF_INET && |
| 257 | s1->in.sin_port == s2->in.sin_port && |
| 258 | s1->in.sin_addr.s_addr == s2->in.sin_addr.s_addr) |
| 259 | return 1; |
| 260 | #ifdef HAVE_IPV6 |
| 261 | if (s1->sa.sa_family == AF_INET6 && |
| 262 | s1->in6.sin6_port == s2->in6.sin6_port && |
| 263 | IN6_ARE_ADDR_EQUAL(&s1->in6.sin6_addr, &s2->in6.sin6_addr)) |
| 264 | return 1; |
| 265 | #endif |
| 266 | } |
| 267 | return 0; |
| 268 | } |
| 269 | |
| 270 | int sa_len(union mysockaddr *addr) |
| 271 | { |
| 272 | #ifdef HAVE_SOCKADDR_SA_LEN |
| 273 | return addr->sa.sa_len; |
| 274 | #else |
| 275 | #ifdef HAVE_IPV6 |
| 276 | if (addr->sa.sa_family == AF_INET6) |
| 277 | return sizeof(addr->in6); |
| 278 | else |
| 279 | #endif |
| 280 | return sizeof(addr->in); |
| 281 | #endif |
| 282 | } |
| 283 | |
| 284 | /* don't use strcasecmp and friends here - they may be messed up by LOCALE */ |
| 285 | int hostname_isequal(char *a, char *b) |
| 286 | { |
| 287 | unsigned int c1, c2; |
| 288 | |
| 289 | do { |
| 290 | c1 = (unsigned char) *a++; |
| 291 | c2 = (unsigned char) *b++; |
| 292 | |
| 293 | if (c1 >= 'A' && c1 <= 'Z') |
| 294 | c1 += 'a' - 'A'; |
| 295 | if (c2 >= 'A' && c2 <= 'Z') |
| 296 | c2 += 'a' - 'A'; |
| 297 | |
| 298 | if (c1 != c2) |
| 299 | return 0; |
| 300 | } while (c1); |
| 301 | |
| 302 | return 1; |
| 303 | } |
| 304 | |
| 305 | time_t dnsmasq_time(void) |
| 306 | { |
| 307 | #ifdef HAVE_BROKEN_RTC |
| 308 | struct tms dummy; |
| 309 | static long tps = 0; |
| 310 | |
| 311 | if (tps == 0) |
| 312 | tps = sysconf(_SC_CLK_TCK); |
| 313 | |
| 314 | return (time_t)(times(&dummy)/tps); |
| 315 | #else |
| 316 | return time(NULL); |
| 317 | #endif |
| 318 | } |
| 319 | |
| 320 | int is_same_net(struct in_addr a, struct in_addr b, struct in_addr mask) |
| 321 | { |
| 322 | return (a.s_addr & mask.s_addr) == (b.s_addr & mask.s_addr); |
| 323 | } |
| 324 | |
| 325 | /* returns port number from address */ |
| 326 | int prettyprint_addr(union mysockaddr *addr, char *buf) |
| 327 | { |
| 328 | int port = 0; |
| 329 | |
| 330 | #ifdef HAVE_IPV6 |
| 331 | if (addr->sa.sa_family == AF_INET) |
| 332 | { |
| 333 | inet_ntop(AF_INET, &addr->in.sin_addr, buf, ADDRSTRLEN); |
| 334 | port = ntohs(addr->in.sin_port); |
| 335 | } |
| 336 | else if (addr->sa.sa_family == AF_INET6) |
| 337 | { |
| 338 | inet_ntop(AF_INET6, &addr->in6.sin6_addr, buf, ADDRSTRLEN); |
| 339 | port = ntohs(addr->in6.sin6_port); |
| 340 | } |
| 341 | #else |
| 342 | strcpy(buf, inet_ntoa(addr->in.sin_addr)); |
| 343 | port = ntohs(addr->in.sin_port); |
| 344 | #endif |
| 345 | |
| 346 | return port; |
| 347 | } |
| 348 | |
| 349 | void prettyprint_time(char *buf, unsigned int t) |
| 350 | { |
| 351 | if (t == 0xffffffff) |
| 352 | sprintf(buf, _("infinite")); |
| 353 | else |
| 354 | { |
| 355 | unsigned int x, p = 0; |
| 356 | if ((x = t/86400)) |
| 357 | p += sprintf(&buf[p], "%dd", x); |
| 358 | if ((x = (t/3600)%24)) |
| 359 | p += sprintf(&buf[p], "%dh", x); |
| 360 | if ((x = (t/60)%60)) |
| 361 | p += sprintf(&buf[p], "%dm", x); |
| 362 | if ((x = t%60)) |
| 363 | p += sprintf(&buf[p], "%ds", x); |
| 364 | } |
| 365 | } |
| 366 | |
| 367 | |
| 368 | /* in may equal out, when maxlen may be -1 (No max len). */ |
| 369 | int parse_hex(char *in, unsigned char *out, int maxlen, |
| 370 | unsigned int *wildcard_mask, int *mac_type) |
| 371 | { |
| 372 | int mask = 0, i = 0; |
| 373 | char *r; |
| 374 | |
| 375 | if (mac_type) |
| 376 | *mac_type = 0; |
| 377 | |
| 378 | while (maxlen == -1 || i < maxlen) |
| 379 | { |
| 380 | for (r = in; *r != 0 && *r != ':' && *r != '-'; r++); |
| 381 | if (*r == 0) |
| 382 | maxlen = i; |
| 383 | |
| 384 | if (r != in ) |
| 385 | { |
| 386 | if (*r == '-' && i == 0 && mac_type) |
| 387 | { |
| 388 | *r = 0; |
| 389 | *mac_type = strtol(in, NULL, 16); |
| 390 | mac_type = NULL; |
| 391 | } |
| 392 | else |
| 393 | { |
| 394 | *r = 0; |
| 395 | mask = mask << 1; |
| 396 | if (strcmp(in, "*") == 0) |
| 397 | mask |= 1; |
| 398 | else |
| 399 | out[i] = strtol(in, NULL, 16); |
| 400 | i++; |
| 401 | } |
| 402 | } |
| 403 | in = r+1; |
| 404 | } |
| 405 | |
| 406 | if (wildcard_mask) |
| 407 | *wildcard_mask = mask; |
| 408 | |
| 409 | return i; |
| 410 | } |
| 411 | |
| 412 | /* return 0 for no match, or (no matched octets) + 1 */ |
| 413 | int memcmp_masked(unsigned char *a, unsigned char *b, int len, unsigned int mask) |
| 414 | { |
| 415 | int i, count; |
| 416 | for (count = 1, i = len - 1; i >= 0; i--, mask = mask >> 1) |
| 417 | if (!(mask & 1)) |
| 418 | { |
| 419 | if (a[i] == b[i]) |
| 420 | count++; |
| 421 | else |
| 422 | return 0; |
| 423 | } |
| 424 | return count; |
| 425 | } |
| 426 | |
| 427 | /* _note_ may copy buffer */ |
| 428 | int expand_buf(struct iovec *iov, size_t size) |
| 429 | { |
| 430 | void *new; |
| 431 | |
| 432 | if (size <= (size_t)iov->iov_len) |
| 433 | return 1; |
| 434 | |
| 435 | if (!(new = whine_malloc(size))) |
| 436 | { |
| 437 | errno = ENOMEM; |
| 438 | return 0; |
| 439 | } |
| 440 | |
| 441 | if (iov->iov_base) |
| 442 | { |
| 443 | memcpy(new, iov->iov_base, iov->iov_len); |
| 444 | free(iov->iov_base); |
| 445 | } |
| 446 | |
| 447 | iov->iov_base = new; |
| 448 | iov->iov_len = size; |
| 449 | |
| 450 | return 1; |
| 451 | } |
| 452 | |
| 453 | char *print_mac(char *buff, unsigned char *mac, int len) |
| 454 | { |
| 455 | char *p = buff; |
| 456 | int i; |
| 457 | |
| 458 | if (len == 0) |
| 459 | sprintf(p, "<null>"); |
| 460 | else |
| 461 | for (i = 0; i < len; i++) |
| 462 | p += sprintf(p, "%.2x%s", mac[i], (i == len - 1) ? "" : ":"); |
| 463 | |
| 464 | return buff; |
| 465 | } |
| 466 | |
| 467 | void bump_maxfd(int fd, int *max) |
| 468 | { |
| 469 | if (fd > *max) |
| 470 | *max = fd; |
| 471 | } |
| 472 | |
| 473 | int retry_send(void) |
| 474 | { |
| 475 | struct timespec waiter; |
| 476 | if (errno == EAGAIN) |
| 477 | { |
| 478 | waiter.tv_sec = 0; |
| 479 | waiter.tv_nsec = 10000; |
| 480 | nanosleep(&waiter, NULL); |
| 481 | return 1; |
| 482 | } |
| 483 | |
| 484 | if (errno == EINTR) |
| 485 | return 1; |
| 486 | |
| 487 | return 0; |
| 488 | } |
| 489 | |
| 490 | int read_write(int fd, unsigned char *packet, int size, int rw) |
| 491 | { |
| 492 | ssize_t n, done; |
| 493 | |
| 494 | for (done = 0; done < size; done += n) |
| 495 | { |
| 496 | retry: |
| 497 | if (rw) |
| 498 | n = read(fd, &packet[done], (size_t)(size - done)); |
| 499 | else |
| 500 | n = write(fd, &packet[done], (size_t)(size - done)); |
| 501 | |
| 502 | if (n == 0) |
| 503 | return 0; |
| 504 | else if (n == -1) |
| 505 | { |
| 506 | if (retry_send() || errno == ENOMEM || errno == ENOBUFS) |
| 507 | goto retry; |
| 508 | else |
| 509 | return 0; |
| 510 | } |
| 511 | } |
| 512 | return 1; |
| 513 | } |
| 514 | |