lh | 9ed821d | 2023-04-07 01:36:19 -0700 | [diff] [blame^] | 1 | /* dnsmasq is Copyright (c) 2000-2021 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 | #if defined(HAVE_LIBIDN2) |
| 28 | #include <idn2.h> |
| 29 | #elif defined(HAVE_IDN) |
| 30 | #include <idna.h> |
| 31 | #endif |
| 32 | |
| 33 | #ifdef HAVE_LINUX_NETWORK |
| 34 | #include <sys/utsname.h> |
| 35 | #endif |
| 36 | |
| 37 | /* SURF random number generator */ |
| 38 | |
| 39 | static u32 seed[32]; |
| 40 | static u32 in[12]; |
| 41 | static u32 out[8]; |
| 42 | static int outleft = 0; |
| 43 | |
| 44 | void rand_init() |
| 45 | { |
| 46 | int fd = open(RANDFILE, O_RDONLY); |
| 47 | |
| 48 | if (fd == -1 || |
| 49 | !read_write(fd, (unsigned char *)&seed, sizeof(seed), 1) || |
| 50 | !read_write(fd, (unsigned char *)&in, sizeof(in), 1)) |
| 51 | die(_("failed to seed the random number generator: %s"), NULL, EC_MISC); |
| 52 | |
| 53 | close(fd); |
| 54 | } |
| 55 | |
| 56 | #define ROTATE(x,b) (((x) << (b)) | ((x) >> (32 - (b)))) |
| 57 | #define MUSH(i,b) x = t[i] += (((x ^ seed[i]) + sum) ^ ROTATE(x,b)); |
| 58 | |
| 59 | static void surf(void) |
| 60 | { |
| 61 | u32 t[12]; u32 x; u32 sum = 0; |
| 62 | int r; int i; int loop; |
| 63 | |
| 64 | for (i = 0;i < 12;++i) t[i] = in[i] ^ seed[12 + i]; |
| 65 | for (i = 0;i < 8;++i) out[i] = seed[24 + i]; |
| 66 | x = t[11]; |
| 67 | for (loop = 0;loop < 2;++loop) { |
| 68 | for (r = 0;r < 16;++r) { |
| 69 | sum += 0x9e3779b9; |
| 70 | MUSH(0,5) MUSH(1,7) MUSH(2,9) MUSH(3,13) |
| 71 | MUSH(4,5) MUSH(5,7) MUSH(6,9) MUSH(7,13) |
| 72 | MUSH(8,5) MUSH(9,7) MUSH(10,9) MUSH(11,13) |
| 73 | } |
| 74 | for (i = 0;i < 8;++i) out[i] ^= t[i + 4]; |
| 75 | } |
| 76 | } |
| 77 | |
| 78 | unsigned short rand16(void) |
| 79 | { |
| 80 | if (!outleft) |
| 81 | { |
| 82 | if (!++in[0]) if (!++in[1]) if (!++in[2]) ++in[3]; |
| 83 | surf(); |
| 84 | outleft = 8; |
| 85 | } |
| 86 | |
| 87 | return (unsigned short) out[--outleft]; |
| 88 | } |
| 89 | |
| 90 | u32 rand32(void) |
| 91 | { |
| 92 | if (!outleft) |
| 93 | { |
| 94 | if (!++in[0]) if (!++in[1]) if (!++in[2]) ++in[3]; |
| 95 | surf(); |
| 96 | outleft = 8; |
| 97 | } |
| 98 | |
| 99 | return out[--outleft]; |
| 100 | } |
| 101 | |
| 102 | u64 rand64(void) |
| 103 | { |
| 104 | static int outleft = 0; |
| 105 | |
| 106 | if (outleft < 2) |
| 107 | { |
| 108 | if (!++in[0]) if (!++in[1]) if (!++in[2]) ++in[3]; |
| 109 | surf(); |
| 110 | outleft = 8; |
| 111 | } |
| 112 | |
| 113 | outleft -= 2; |
| 114 | |
| 115 | return (u64)out[outleft+1] + (((u64)out[outleft]) << 32); |
| 116 | } |
| 117 | |
| 118 | /* returns 2 if names is OK but contains one or more underscores */ |
| 119 | static int check_name(char *in) |
| 120 | { |
| 121 | /* remove trailing . |
| 122 | also fail empty string and label > 63 chars */ |
| 123 | size_t dotgap = 0, l = strlen(in); |
| 124 | char c; |
| 125 | int nowhite = 0; |
| 126 | int hasuscore = 0; |
| 127 | |
| 128 | if (l == 0 || l > MAXDNAME) return 0; |
| 129 | |
| 130 | if (in[l-1] == '.') |
| 131 | { |
| 132 | in[l-1] = 0; |
| 133 | nowhite = 1; |
| 134 | } |
| 135 | |
| 136 | for (; (c = *in); in++) |
| 137 | { |
| 138 | if (c == '.') |
| 139 | dotgap = 0; |
| 140 | else if (++dotgap > MAXLABEL) |
| 141 | return 0; |
| 142 | else if (isascii((unsigned char)c) && iscntrl((unsigned char)c)) |
| 143 | /* iscntrl only gives expected results for ascii */ |
| 144 | return 0; |
| 145 | #if !defined(HAVE_IDN) && !defined(HAVE_LIBIDN2) |
| 146 | else if (!isascii((unsigned char)c)) |
| 147 | return 0; |
| 148 | #endif |
| 149 | else if (c != ' ') |
| 150 | { |
| 151 | nowhite = 1; |
| 152 | if (c == '_') |
| 153 | hasuscore = 1; |
| 154 | } |
| 155 | } |
| 156 | |
| 157 | if (!nowhite) |
| 158 | return 0; |
| 159 | |
| 160 | return hasuscore ? 2 : 1; |
| 161 | } |
| 162 | |
| 163 | /* Hostnames have a more limited valid charset than domain names |
| 164 | so check for legal char a-z A-Z 0-9 - _ |
| 165 | Note that this may receive a FQDN, so only check the first label |
| 166 | for the tighter criteria. */ |
| 167 | int legal_hostname(char *name) |
| 168 | { |
| 169 | char c; |
| 170 | int first; |
| 171 | |
| 172 | if (!check_name(name)) |
| 173 | return 0; |
| 174 | |
| 175 | for (first = 1; (c = *name); name++, first = 0) |
| 176 | /* check for legal char a-z A-Z 0-9 - _ . */ |
| 177 | { |
| 178 | if ((c >= 'A' && c <= 'Z') || |
| 179 | (c >= 'a' && c <= 'z') || |
| 180 | (c >= '0' && c <= '9')) |
| 181 | continue; |
| 182 | |
| 183 | if (!first && (c == '-' || c == '_')) |
| 184 | continue; |
| 185 | |
| 186 | /* end of hostname part */ |
| 187 | if (c == '.') |
| 188 | return 1; |
| 189 | |
| 190 | return 0; |
| 191 | } |
| 192 | |
| 193 | return 1; |
| 194 | } |
| 195 | |
| 196 | char *canonicalise(char *in, int *nomem) |
| 197 | { |
| 198 | char *ret = NULL; |
| 199 | int rc; |
| 200 | |
| 201 | if (nomem) |
| 202 | *nomem = 0; |
| 203 | |
| 204 | if (!(rc = check_name(in))) |
| 205 | return NULL; |
| 206 | |
| 207 | #if defined(HAVE_LIBIDN2) && (!defined(IDN2_VERSION_NUMBER) || IDN2_VERSION_NUMBER < 0x02000003) |
| 208 | /* older libidn2 strips underscores, so don't do IDN processing |
| 209 | if the name has an underscore (check_name() returned 2) */ |
| 210 | if (rc != 2) |
| 211 | #endif |
| 212 | #if defined(HAVE_IDN) || defined(HAVE_LIBIDN2) |
| 213 | { |
| 214 | # ifdef HAVE_LIBIDN2 |
| 215 | rc = idn2_to_ascii_lz(in, &ret, IDN2_NONTRANSITIONAL); |
| 216 | if (rc == IDN2_DISALLOWED) |
| 217 | rc = idn2_to_ascii_lz(in, &ret, IDN2_TRANSITIONAL); |
| 218 | # else |
| 219 | rc = idna_to_ascii_lz(in, &ret, 0); |
| 220 | # endif |
| 221 | if (rc != IDNA_SUCCESS) |
| 222 | { |
| 223 | if (ret) |
| 224 | free(ret); |
| 225 | |
| 226 | if (nomem && (rc == IDNA_MALLOC_ERROR || rc == IDNA_DLOPEN_ERROR)) |
| 227 | { |
| 228 | my_syslog(LOG_ERR, _("failed to allocate memory")); |
| 229 | *nomem = 1; |
| 230 | } |
| 231 | |
| 232 | return NULL; |
| 233 | } |
| 234 | |
| 235 | return ret; |
| 236 | } |
| 237 | #endif |
| 238 | |
| 239 | if ((ret = whine_malloc(strlen(in)+1))) |
| 240 | strcpy(ret, in); |
| 241 | else if (nomem) |
| 242 | *nomem = 1; |
| 243 | |
| 244 | return ret; |
| 245 | } |
| 246 | |
| 247 | unsigned char *do_rfc1035_name(unsigned char *p, char *sval, char *limit) |
| 248 | { |
| 249 | int j; |
| 250 | |
| 251 | while (sval && *sval) |
| 252 | { |
| 253 | unsigned char *cp = p++; |
| 254 | |
| 255 | if (limit && p > (unsigned char*)limit) |
| 256 | return NULL; |
| 257 | |
| 258 | for (j = 0; *sval && (*sval != '.'); sval++, j++) |
| 259 | { |
| 260 | if (limit && p + 1 > (unsigned char*)limit) |
| 261 | return NULL; |
| 262 | |
| 263 | #ifdef HAVE_DNSSEC |
| 264 | if (option_bool(OPT_DNSSEC_VALID) && *sval == NAME_ESCAPE) |
| 265 | *p++ = (*(++sval))-1; |
| 266 | else |
| 267 | #endif |
| 268 | *p++ = *sval; |
| 269 | } |
| 270 | |
| 271 | *cp = j; |
| 272 | if (*sval) |
| 273 | sval++; |
| 274 | } |
| 275 | |
| 276 | return p; |
| 277 | } |
| 278 | |
| 279 | /* for use during startup */ |
| 280 | void *safe_malloc(size_t size) |
| 281 | { |
| 282 | void *ret = calloc(1, size); |
| 283 | |
| 284 | if (!ret) |
| 285 | die(_("could not get memory"), NULL, EC_NOMEM); |
| 286 | |
| 287 | return ret; |
| 288 | } |
| 289 | |
| 290 | /* Ensure limited size string is always terminated. |
| 291 | * Can be replaced by (void)strlcpy() on some platforms */ |
| 292 | void safe_strncpy(char *dest, const char *src, size_t size) |
| 293 | { |
| 294 | if (size != 0) |
| 295 | { |
| 296 | dest[size-1] = '\0'; |
| 297 | strncpy(dest, src, size-1); |
| 298 | } |
| 299 | } |
| 300 | |
| 301 | void safe_pipe(int *fd, int read_noblock) |
| 302 | { |
| 303 | if (pipe(fd) == -1 || |
| 304 | !fix_fd(fd[1]) || |
| 305 | (read_noblock && !fix_fd(fd[0]))) |
| 306 | die(_("cannot create pipe: %s"), NULL, EC_MISC); |
| 307 | } |
| 308 | |
| 309 | void *whine_malloc(size_t size) |
| 310 | { |
| 311 | void *ret = calloc(1, size); |
| 312 | |
| 313 | if (!ret) |
| 314 | my_syslog(LOG_ERR, _("failed to allocate %d bytes"), (int) size); |
| 315 | |
| 316 | return ret; |
| 317 | } |
| 318 | |
| 319 | int sockaddr_isequal(const union mysockaddr *s1, const union mysockaddr *s2) |
| 320 | { |
| 321 | if (s1->sa.sa_family == s2->sa.sa_family) |
| 322 | { |
| 323 | if (s1->sa.sa_family == AF_INET && |
| 324 | s1->in.sin_port == s2->in.sin_port && |
| 325 | s1->in.sin_addr.s_addr == s2->in.sin_addr.s_addr) |
| 326 | return 1; |
| 327 | |
| 328 | if (s1->sa.sa_family == AF_INET6 && |
| 329 | s1->in6.sin6_port == s2->in6.sin6_port && |
| 330 | s1->in6.sin6_scope_id == s2->in6.sin6_scope_id && |
| 331 | IN6_ARE_ADDR_EQUAL(&s1->in6.sin6_addr, &s2->in6.sin6_addr)) |
| 332 | return 1; |
| 333 | } |
| 334 | return 0; |
| 335 | } |
| 336 | |
| 337 | int sa_len(union mysockaddr *addr) |
| 338 | { |
| 339 | #ifdef HAVE_SOCKADDR_SA_LEN |
| 340 | return addr->sa.sa_len; |
| 341 | #else |
| 342 | if (addr->sa.sa_family == AF_INET6) |
| 343 | return sizeof(addr->in6); |
| 344 | else |
| 345 | return sizeof(addr->in); |
| 346 | #endif |
| 347 | } |
| 348 | |
| 349 | /* don't use strcasecmp and friends here - they may be messed up by LOCALE */ |
| 350 | int hostname_isequal(const char *a, const char *b) |
| 351 | { |
| 352 | unsigned int c1, c2; |
| 353 | |
| 354 | do { |
| 355 | c1 = (unsigned char) *a++; |
| 356 | c2 = (unsigned char) *b++; |
| 357 | |
| 358 | if (c1 >= 'A' && c1 <= 'Z') |
| 359 | c1 += 'a' - 'A'; |
| 360 | if (c2 >= 'A' && c2 <= 'Z') |
| 361 | c2 += 'a' - 'A'; |
| 362 | |
| 363 | if (c1 != c2) |
| 364 | return 0; |
| 365 | } while (c1); |
| 366 | |
| 367 | return 1; |
| 368 | } |
| 369 | |
| 370 | /* is b equal to or a subdomain of a return 2 for equal, 1 for subdomain */ |
| 371 | int hostname_issubdomain(char *a, char *b) |
| 372 | { |
| 373 | char *ap, *bp; |
| 374 | unsigned int c1, c2; |
| 375 | |
| 376 | /* move to the end */ |
| 377 | for (ap = a; *ap; ap++); |
| 378 | for (bp = b; *bp; bp++); |
| 379 | |
| 380 | /* a shorter than b or a empty. */ |
| 381 | if ((bp - b) < (ap - a) || ap == a) |
| 382 | return 0; |
| 383 | |
| 384 | do |
| 385 | { |
| 386 | c1 = (unsigned char) *(--ap); |
| 387 | c2 = (unsigned char) *(--bp); |
| 388 | |
| 389 | if (c1 >= 'A' && c1 <= 'Z') |
| 390 | c1 += 'a' - 'A'; |
| 391 | if (c2 >= 'A' && c2 <= 'Z') |
| 392 | c2 += 'a' - 'A'; |
| 393 | |
| 394 | if (c1 != c2) |
| 395 | return 0; |
| 396 | } while (ap != a); |
| 397 | |
| 398 | if (bp == b) |
| 399 | return 2; |
| 400 | |
| 401 | if (*(--bp) == '.') |
| 402 | return 1; |
| 403 | |
| 404 | return 0; |
| 405 | } |
| 406 | |
| 407 | |
| 408 | time_t dnsmasq_time(void) |
| 409 | { |
| 410 | #ifdef HAVE_BROKEN_RTC |
| 411 | struct tms dummy; |
| 412 | static long tps = 0; |
| 413 | |
| 414 | if (tps == 0) |
| 415 | tps = sysconf(_SC_CLK_TCK); |
| 416 | |
| 417 | return (time_t)(times(&dummy)/tps); |
| 418 | #else |
| 419 | return time(NULL); |
| 420 | #endif |
| 421 | } |
| 422 | |
| 423 | int netmask_length(struct in_addr mask) |
| 424 | { |
| 425 | int zero_count = 0; |
| 426 | |
| 427 | while (0x0 == (mask.s_addr & 0x1) && zero_count < 32) |
| 428 | { |
| 429 | mask.s_addr >>= 1; |
| 430 | zero_count++; |
| 431 | } |
| 432 | |
| 433 | return 32 - zero_count; |
| 434 | } |
| 435 | |
| 436 | int is_same_net(struct in_addr a, struct in_addr b, struct in_addr mask) |
| 437 | { |
| 438 | return (a.s_addr & mask.s_addr) == (b.s_addr & mask.s_addr); |
| 439 | } |
| 440 | |
| 441 | int is_same_net_prefix(struct in_addr a, struct in_addr b, int prefix) |
| 442 | { |
| 443 | struct in_addr mask; |
| 444 | |
| 445 | mask.s_addr = htonl(~((1 << (32 - prefix)) - 1)); |
| 446 | |
| 447 | return is_same_net(a, b, mask); |
| 448 | } |
| 449 | |
| 450 | |
| 451 | int is_same_net6(struct in6_addr *a, struct in6_addr *b, int prefixlen) |
| 452 | { |
| 453 | int pfbytes = prefixlen >> 3; |
| 454 | int pfbits = prefixlen & 7; |
| 455 | |
| 456 | if (memcmp(&a->s6_addr, &b->s6_addr, pfbytes) != 0) |
| 457 | return 0; |
| 458 | |
| 459 | if (pfbits == 0 || |
| 460 | (a->s6_addr[pfbytes] >> (8 - pfbits) == b->s6_addr[pfbytes] >> (8 - pfbits))) |
| 461 | return 1; |
| 462 | |
| 463 | return 0; |
| 464 | } |
| 465 | |
| 466 | /* return least significant 64 bits if IPv6 address */ |
| 467 | u64 addr6part(struct in6_addr *addr) |
| 468 | { |
| 469 | int i; |
| 470 | u64 ret = 0; |
| 471 | |
| 472 | for (i = 8; i < 16; i++) |
| 473 | ret = (ret << 8) + addr->s6_addr[i]; |
| 474 | |
| 475 | return ret; |
| 476 | } |
| 477 | |
| 478 | void setaddr6part(struct in6_addr *addr, u64 host) |
| 479 | { |
| 480 | int i; |
| 481 | |
| 482 | for (i = 15; i >= 8; i--) |
| 483 | { |
| 484 | addr->s6_addr[i] = host; |
| 485 | host = host >> 8; |
| 486 | } |
| 487 | } |
| 488 | |
| 489 | |
| 490 | /* returns port number from address */ |
| 491 | int prettyprint_addr(union mysockaddr *addr, char *buf) |
| 492 | { |
| 493 | int port = 0; |
| 494 | |
| 495 | if (addr->sa.sa_family == AF_INET) |
| 496 | { |
| 497 | inet_ntop(AF_INET, &addr->in.sin_addr, buf, ADDRSTRLEN); |
| 498 | port = ntohs(addr->in.sin_port); |
| 499 | } |
| 500 | else if (addr->sa.sa_family == AF_INET6) |
| 501 | { |
| 502 | char name[IF_NAMESIZE]; |
| 503 | inet_ntop(AF_INET6, &addr->in6.sin6_addr, buf, ADDRSTRLEN); |
| 504 | if (addr->in6.sin6_scope_id != 0 && |
| 505 | if_indextoname(addr->in6.sin6_scope_id, name) && |
| 506 | strlen(buf) + strlen(name) + 2 <= ADDRSTRLEN) |
| 507 | { |
| 508 | strcat(buf, "%"); |
| 509 | strcat(buf, name); |
| 510 | } |
| 511 | port = ntohs(addr->in6.sin6_port); |
| 512 | } |
| 513 | |
| 514 | return port; |
| 515 | } |
| 516 | |
| 517 | void prettyprint_time(char *buf, unsigned int t) |
| 518 | { |
| 519 | if (t == 0xffffffff) |
| 520 | sprintf(buf, _("infinite")); |
| 521 | else |
| 522 | { |
| 523 | unsigned int x, p = 0; |
| 524 | if ((x = t/86400)) |
| 525 | p += sprintf(&buf[p], "%ud", x); |
| 526 | if ((x = (t/3600)%24)) |
| 527 | p += sprintf(&buf[p], "%uh", x); |
| 528 | if ((x = (t/60)%60)) |
| 529 | p += sprintf(&buf[p], "%um", x); |
| 530 | if ((x = t%60)) |
| 531 | p += sprintf(&buf[p], "%us", x); |
| 532 | } |
| 533 | } |
| 534 | |
| 535 | |
| 536 | /* in may equal out, when maxlen may be -1 (No max len). |
| 537 | Return -1 for extraneous no-hex chars found. */ |
| 538 | int parse_hex(char *in, unsigned char *out, int maxlen, |
| 539 | unsigned int *wildcard_mask, int *mac_type) |
| 540 | { |
| 541 | int done = 0, mask = 0, i = 0; |
| 542 | char *r; |
| 543 | |
| 544 | if (mac_type) |
| 545 | *mac_type = 0; |
| 546 | |
| 547 | while (!done && (maxlen == -1 || i < maxlen)) |
| 548 | { |
| 549 | for (r = in; *r != 0 && *r != ':' && *r != '-' && *r != ' '; r++) |
| 550 | if (*r != '*' && !isxdigit((unsigned char)*r)) |
| 551 | return -1; |
| 552 | |
| 553 | if (*r == 0) |
| 554 | done = 1; |
| 555 | |
| 556 | if (r != in ) |
| 557 | { |
| 558 | if (*r == '-' && i == 0 && mac_type) |
| 559 | { |
| 560 | *r = 0; |
| 561 | *mac_type = strtol(in, NULL, 16); |
| 562 | mac_type = NULL; |
| 563 | } |
| 564 | else |
| 565 | { |
| 566 | *r = 0; |
| 567 | if (strcmp(in, "*") == 0) |
| 568 | { |
| 569 | mask = (mask << 1) | 1; |
| 570 | i++; |
| 571 | } |
| 572 | else |
| 573 | { |
| 574 | int j, bytes = (1 + (r - in))/2; |
| 575 | for (j = 0; j < bytes; j++) |
| 576 | { |
| 577 | char sav = sav; |
| 578 | if (j < bytes - 1) |
| 579 | { |
| 580 | sav = in[(j+1)*2]; |
| 581 | in[(j+1)*2] = 0; |
| 582 | } |
| 583 | /* checks above allow mix of hexdigit and *, which |
| 584 | is illegal. */ |
| 585 | if (strchr(&in[j*2], '*')) |
| 586 | return -1; |
| 587 | out[i] = strtol(&in[j*2], NULL, 16); |
| 588 | mask = mask << 1; |
| 589 | if (++i == maxlen) |
| 590 | break; |
| 591 | if (j < bytes - 1) |
| 592 | in[(j+1)*2] = sav; |
| 593 | } |
| 594 | } |
| 595 | } |
| 596 | } |
| 597 | in = r+1; |
| 598 | } |
| 599 | |
| 600 | if (wildcard_mask) |
| 601 | *wildcard_mask = mask; |
| 602 | |
| 603 | return i; |
| 604 | } |
| 605 | |
| 606 | /* return 0 for no match, or (no matched octets) + 1 */ |
| 607 | int memcmp_masked(unsigned char *a, unsigned char *b, int len, unsigned int mask) |
| 608 | { |
| 609 | int i, count; |
| 610 | for (count = 1, i = len - 1; i >= 0; i--, mask = mask >> 1) |
| 611 | if (!(mask & 1)) |
| 612 | { |
| 613 | if (a[i] == b[i]) |
| 614 | count++; |
| 615 | else |
| 616 | return 0; |
| 617 | } |
| 618 | return count; |
| 619 | } |
| 620 | |
| 621 | /* _note_ may copy buffer */ |
| 622 | int expand_buf(struct iovec *iov, size_t size) |
| 623 | { |
| 624 | void *new; |
| 625 | |
| 626 | if (size <= (size_t)iov->iov_len) |
| 627 | return 1; |
| 628 | |
| 629 | if (!(new = whine_malloc(size))) |
| 630 | { |
| 631 | errno = ENOMEM; |
| 632 | return 0; |
| 633 | } |
| 634 | |
| 635 | if (iov->iov_base) |
| 636 | { |
| 637 | memcpy(new, iov->iov_base, iov->iov_len); |
| 638 | free(iov->iov_base); |
| 639 | } |
| 640 | |
| 641 | iov->iov_base = new; |
| 642 | iov->iov_len = size; |
| 643 | |
| 644 | return 1; |
| 645 | } |
| 646 | |
| 647 | char *print_mac(char *buff, unsigned char *mac, int len) |
| 648 | { |
| 649 | char *p = buff; |
| 650 | int i; |
| 651 | |
| 652 | if (len == 0) |
| 653 | sprintf(p, "<null>"); |
| 654 | else |
| 655 | for (i = 0; i < len; i++) |
| 656 | p += sprintf(p, "%.2x%s", mac[i], (i == len - 1) ? "" : ":"); |
| 657 | |
| 658 | return buff; |
| 659 | } |
| 660 | |
| 661 | /* rc is return from sendto and friends. |
| 662 | Return 1 if we should retry. |
| 663 | Set errno to zero if we succeeded. */ |
| 664 | int retry_send(ssize_t rc) |
| 665 | { |
| 666 | static int retries = 0; |
| 667 | struct timespec waiter; |
| 668 | |
| 669 | if (rc != -1) |
| 670 | { |
| 671 | retries = 0; |
| 672 | errno = 0; |
| 673 | return 0; |
| 674 | } |
| 675 | |
| 676 | /* Linux kernels can return EAGAIN in perpetuity when calling |
| 677 | sendmsg() and the relevant interface has gone. Here we loop |
| 678 | retrying in EAGAIN for 1 second max, to avoid this hanging |
| 679 | dnsmasq. */ |
| 680 | |
| 681 | if (errno == EAGAIN || errno == EWOULDBLOCK) |
| 682 | { |
| 683 | waiter.tv_sec = 0; |
| 684 | waiter.tv_nsec = 10000; |
| 685 | nanosleep(&waiter, NULL); |
| 686 | if (retries++ < 1000) |
| 687 | return 1; |
| 688 | } |
| 689 | |
| 690 | retries = 0; |
| 691 | |
| 692 | if (errno == EINTR) |
| 693 | return 1; |
| 694 | |
| 695 | return 0; |
| 696 | } |
| 697 | |
| 698 | int read_write(int fd, unsigned char *packet, int size, int rw) |
| 699 | { |
| 700 | ssize_t n, done; |
| 701 | |
| 702 | for (done = 0; done < size; done += n) |
| 703 | { |
| 704 | do { |
| 705 | if (rw) |
| 706 | n = read(fd, &packet[done], (size_t)(size - done)); |
| 707 | else |
| 708 | n = write(fd, &packet[done], (size_t)(size - done)); |
| 709 | |
| 710 | if (n == 0) |
| 711 | return 0; |
| 712 | |
| 713 | } while (retry_send(n) || errno == ENOMEM || errno == ENOBUFS); |
| 714 | |
| 715 | if (errno != 0) |
| 716 | return 0; |
| 717 | } |
| 718 | |
| 719 | return 1; |
| 720 | } |
| 721 | |
| 722 | /* close all fds except STDIN, STDOUT and STDERR, spare1, spare2 and spare3 */ |
| 723 | void close_fds(long max_fd, int spare1, int spare2, int spare3) |
| 724 | { |
| 725 | /* On Linux, use the /proc/ filesystem to find which files |
| 726 | are actually open, rather than iterate over the whole space, |
| 727 | for efficiency reasons. If this fails we drop back to the dumb code. */ |
| 728 | #ifdef HAVE_LINUX_NETWORK |
| 729 | DIR *d; |
| 730 | |
| 731 | if ((d = opendir("/proc/self/fd"))) |
| 732 | { |
| 733 | struct dirent *de; |
| 734 | |
| 735 | while ((de = readdir(d))) |
| 736 | { |
| 737 | long fd; |
| 738 | char *e = NULL; |
| 739 | |
| 740 | errno = 0; |
| 741 | fd = strtol(de->d_name, &e, 10); |
| 742 | |
| 743 | if (errno != 0 || !e || *e || fd == dirfd(d) || |
| 744 | fd == STDOUT_FILENO || fd == STDERR_FILENO || fd == STDIN_FILENO || |
| 745 | fd == spare1 || fd == spare2 || fd == spare3) |
| 746 | continue; |
| 747 | |
| 748 | close(fd); |
| 749 | } |
| 750 | |
| 751 | closedir(d); |
| 752 | return; |
| 753 | } |
| 754 | #endif |
| 755 | |
| 756 | /* fallback, dumb code. */ |
| 757 | for (max_fd--; max_fd >= 0; max_fd--) |
| 758 | if (max_fd != STDOUT_FILENO && max_fd != STDERR_FILENO && max_fd != STDIN_FILENO && |
| 759 | max_fd != spare1 && max_fd != spare2 && max_fd != spare3) |
| 760 | close(max_fd); |
| 761 | } |
| 762 | |
| 763 | /* Basically match a string value against a wildcard pattern. */ |
| 764 | int wildcard_match(const char* wildcard, const char* match) |
| 765 | { |
| 766 | while (*wildcard && *match) |
| 767 | { |
| 768 | if (*wildcard == '*') |
| 769 | return 1; |
| 770 | |
| 771 | if (*wildcard != *match) |
| 772 | return 0; |
| 773 | |
| 774 | ++wildcard; |
| 775 | ++match; |
| 776 | } |
| 777 | |
| 778 | return *wildcard == *match; |
| 779 | } |
| 780 | |
| 781 | /* The same but comparing a maximum of NUM characters, like strncmp. */ |
| 782 | int wildcard_matchn(const char* wildcard, const char* match, int num) |
| 783 | { |
| 784 | while (*wildcard && *match && num) |
| 785 | { |
| 786 | if (*wildcard == '*') |
| 787 | return 1; |
| 788 | |
| 789 | if (*wildcard != *match) |
| 790 | return 0; |
| 791 | |
| 792 | ++wildcard; |
| 793 | ++match; |
| 794 | --num; |
| 795 | } |
| 796 | |
| 797 | return (!num) || (*wildcard == *match); |
| 798 | } |
| 799 | |
| 800 | #ifdef HAVE_LINUX_NETWORK |
| 801 | int kernel_version(void) |
| 802 | { |
| 803 | struct utsname utsname; |
| 804 | int version; |
| 805 | char *split; |
| 806 | |
| 807 | if (uname(&utsname) < 0) |
| 808 | die(_("failed to find kernel version: %s"), NULL, EC_MISC); |
| 809 | |
| 810 | split = strtok(utsname.release, "."); |
| 811 | version = (split ? atoi(split) : 0); |
| 812 | split = strtok(NULL, "."); |
| 813 | version = version * 256 + (split ? atoi(split) : 0); |
| 814 | split = strtok(NULL, "."); |
| 815 | return version * 256 + (split ? atoi(split) : 0); |
| 816 | } |
| 817 | #endif |