Gilad Arnold | 968bf19 | 2015-07-17 00:23:30 -0700 | [diff] [blame] | 1 | |
| 2 | /* Copyright 2005 by Dominick Meglio |
| 3 | * |
| 4 | * Permission to use, copy, modify, and distribute this |
| 5 | * software and its documentation for any purpose and without |
| 6 | * fee is hereby granted, provided that the above copyright |
| 7 | * notice appear in all copies and that both that copyright |
| 8 | * notice and this permission notice appear in supporting |
| 9 | * documentation, and that the name of M.I.T. not be used in |
| 10 | * advertising or publicity pertaining to distribution of the |
| 11 | * software without specific, written prior permission. |
| 12 | * M.I.T. makes no representations about the suitability of |
| 13 | * this software for any purpose. It is provided "as is" |
| 14 | * without express or implied warranty. |
| 15 | */ |
| 16 | #include "ares_setup.h" |
| 17 | |
| 18 | #ifdef HAVE_GETSERVBYPORT_R |
| 19 | # if !defined(GETSERVBYPORT_R_ARGS) || \ |
| 20 | (GETSERVBYPORT_R_ARGS < 4) || (GETSERVBYPORT_R_ARGS > 6) |
| 21 | # error "you MUST specifiy a valid number of arguments for getservbyport_r" |
| 22 | # endif |
| 23 | #endif |
| 24 | |
| 25 | #ifdef HAVE_SYS_SOCKET_H |
| 26 | # include <sys/socket.h> |
| 27 | #endif |
| 28 | #ifdef HAVE_NETINET_IN_H |
| 29 | # include <netinet/in.h> |
| 30 | #endif |
| 31 | #ifdef HAVE_NETDB_H |
| 32 | # include <netdb.h> |
| 33 | #endif |
| 34 | #ifdef HAVE_ARPA_INET_H |
| 35 | # include <arpa/inet.h> |
| 36 | #endif |
| 37 | #ifdef HAVE_ARPA_NAMESER_H |
| 38 | # include <arpa/nameser.h> |
| 39 | #else |
| 40 | # include "nameser.h" |
| 41 | #endif |
| 42 | #ifdef HAVE_ARPA_NAMESER_COMPAT_H |
| 43 | # include <arpa/nameser_compat.h> |
| 44 | #endif |
| 45 | |
| 46 | #ifdef HAVE_NET_IF_H |
| 47 | #include <net/if.h> |
| 48 | #endif |
| 49 | |
| 50 | #ifdef HAVE_UNISTD_H |
| 51 | #include <unistd.h> |
| 52 | #endif |
| 53 | |
| 54 | #include <stdio.h> |
| 55 | #include <stdlib.h> |
| 56 | #include <string.h> |
| 57 | |
| 58 | #include "ares.h" |
| 59 | #include "ares_ipv6.h" |
| 60 | #include "inet_ntop.h" |
| 61 | #include "ares_nowarn.h" |
| 62 | #include "ares_private.h" |
| 63 | |
| 64 | struct nameinfo_query { |
| 65 | ares_nameinfo_callback callback; |
| 66 | void *arg; |
| 67 | union { |
| 68 | struct sockaddr_in addr4; |
| 69 | struct sockaddr_in6 addr6; |
| 70 | } addr; |
| 71 | int family; |
| 72 | int flags; |
| 73 | int timeouts; |
| 74 | }; |
| 75 | |
| 76 | #ifdef HAVE_SOCKADDR_IN6_SIN6_SCOPE_ID |
| 77 | #define IPBUFSIZ \ |
| 78 | (sizeof("ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255") + IF_NAMESIZE) |
| 79 | #else |
| 80 | #define IPBUFSIZ \ |
| 81 | (sizeof("ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255")) |
| 82 | #endif |
| 83 | |
| 84 | static void nameinfo_callback(void *arg, int status, int timeouts, |
| 85 | struct hostent *host); |
| 86 | static char *lookup_service(unsigned short port, int flags, |
| 87 | char *buf, size_t buflen); |
| 88 | #ifdef HAVE_SOCKADDR_IN6_SIN6_SCOPE_ID |
| 89 | static void append_scopeid(struct sockaddr_in6 *addr6, unsigned int scopeid, |
| 90 | char *buf, size_t buflen); |
| 91 | #endif |
| 92 | static char *ares_striendstr(const char *s1, const char *s2); |
| 93 | |
| 94 | void ares_getnameinfo(ares_channel channel, const struct sockaddr *sa, |
| 95 | ares_socklen_t salen, |
| 96 | int flags, ares_nameinfo_callback callback, void *arg) |
| 97 | { |
| 98 | struct sockaddr_in *addr = NULL; |
| 99 | struct sockaddr_in6 *addr6 = NULL; |
| 100 | struct nameinfo_query *niquery; |
| 101 | unsigned int port = 0; |
| 102 | |
| 103 | /* Validate socket address family and length */ |
| 104 | if ((sa->sa_family == AF_INET) && |
| 105 | (salen == sizeof(struct sockaddr_in))) |
| 106 | { |
| 107 | addr = (struct sockaddr_in *)sa; |
| 108 | port = addr->sin_port; |
| 109 | } |
| 110 | else if ((sa->sa_family == AF_INET6) && |
| 111 | (salen == sizeof(struct sockaddr_in6))) |
| 112 | { |
| 113 | addr6 = (struct sockaddr_in6 *)sa; |
| 114 | port = addr6->sin6_port; |
| 115 | } |
| 116 | else |
| 117 | { |
| 118 | callback(arg, ARES_ENOTIMP, 0, NULL, NULL); |
| 119 | return; |
| 120 | } |
| 121 | |
| 122 | /* If neither, assume they want a host */ |
| 123 | if (!(flags & ARES_NI_LOOKUPSERVICE) && !(flags & ARES_NI_LOOKUPHOST)) |
| 124 | flags |= ARES_NI_LOOKUPHOST; |
| 125 | |
| 126 | /* All they want is a service, no need for DNS */ |
| 127 | if ((flags & ARES_NI_LOOKUPSERVICE) && !(flags & ARES_NI_LOOKUPHOST)) |
| 128 | { |
| 129 | char buf[33], *service; |
| 130 | |
| 131 | service = lookup_service((unsigned short)(port & 0xffff), |
| 132 | flags, buf, sizeof(buf)); |
| 133 | callback(arg, ARES_SUCCESS, 0, NULL, service); |
| 134 | return; |
| 135 | } |
| 136 | |
| 137 | /* They want a host lookup */ |
| 138 | if ((flags & ARES_NI_LOOKUPHOST)) |
| 139 | { |
| 140 | /* A numeric host can be handled without DNS */ |
| 141 | if ((flags & ARES_NI_NUMERICHOST)) |
| 142 | { |
| 143 | char ipbuf[IPBUFSIZ]; |
| 144 | char srvbuf[33]; |
| 145 | char *service = NULL; |
| 146 | ipbuf[0] = 0; |
| 147 | |
| 148 | /* Specifying not to lookup a host, but then saying a host |
| 149 | * is required has to be illegal. |
| 150 | */ |
| 151 | if (flags & ARES_NI_NAMEREQD) |
| 152 | { |
| 153 | callback(arg, ARES_EBADFLAGS, 0, NULL, NULL); |
| 154 | return; |
| 155 | } |
| 156 | if (salen == sizeof(struct sockaddr_in6)) |
| 157 | { |
| 158 | ares_inet_ntop(AF_INET6, &addr6->sin6_addr, ipbuf, IPBUFSIZ); |
| 159 | /* If the system supports scope IDs, use it */ |
| 160 | #ifdef HAVE_SOCKADDR_IN6_SIN6_SCOPE_ID |
| 161 | append_scopeid(addr6, flags, ipbuf, sizeof(ipbuf)); |
| 162 | #endif |
| 163 | } |
| 164 | else |
| 165 | { |
| 166 | ares_inet_ntop(AF_INET, &addr->sin_addr, ipbuf, IPBUFSIZ); |
| 167 | } |
| 168 | /* They also want a service */ |
| 169 | if (flags & ARES_NI_LOOKUPSERVICE) |
| 170 | service = lookup_service((unsigned short)(port & 0xffff), |
| 171 | flags, srvbuf, sizeof(srvbuf)); |
| 172 | callback(arg, ARES_SUCCESS, 0, ipbuf, service); |
| 173 | return; |
| 174 | } |
| 175 | /* This is where a DNS lookup becomes necessary */ |
| 176 | else |
| 177 | { |
| 178 | niquery = malloc(sizeof(struct nameinfo_query)); |
| 179 | if (!niquery) |
| 180 | { |
| 181 | callback(arg, ARES_ENOMEM, 0, NULL, NULL); |
| 182 | return; |
| 183 | } |
| 184 | niquery->callback = callback; |
| 185 | niquery->arg = arg; |
| 186 | niquery->flags = flags; |
| 187 | niquery->timeouts = 0; |
| 188 | if (sa->sa_family == AF_INET) |
| 189 | { |
| 190 | niquery->family = AF_INET; |
| 191 | memcpy(&niquery->addr.addr4, addr, sizeof(struct in_addr)); |
| 192 | ares_gethostbyaddr(channel, &addr->sin_addr, |
| 193 | sizeof(struct in_addr), AF_INET, |
| 194 | nameinfo_callback, niquery); |
| 195 | } |
| 196 | else |
| 197 | { |
| 198 | niquery->family = AF_INET6; |
| 199 | memcpy(&niquery->addr.addr6, addr6, sizeof(struct ares_in6_addr)); |
| 200 | ares_gethostbyaddr(channel, &addr6->sin6_addr, |
| 201 | sizeof(struct ares_in6_addr), AF_INET6, |
| 202 | nameinfo_callback, niquery); |
| 203 | } |
| 204 | } |
| 205 | } |
| 206 | } |
| 207 | |
| 208 | static void nameinfo_callback(void *arg, int status, int timeouts, |
| 209 | struct hostent *host) |
| 210 | { |
| 211 | struct nameinfo_query *niquery = (struct nameinfo_query *) arg; |
| 212 | char srvbuf[33]; |
| 213 | char *service = NULL; |
| 214 | |
| 215 | niquery->timeouts += timeouts; |
| 216 | if (status == ARES_SUCCESS) |
| 217 | { |
| 218 | /* They want a service too */ |
| 219 | if (niquery->flags & ARES_NI_LOOKUPSERVICE) |
| 220 | { |
| 221 | if (niquery->family == AF_INET) |
| 222 | service = lookup_service(niquery->addr.addr4.sin_port, |
| 223 | niquery->flags, srvbuf, sizeof(srvbuf)); |
| 224 | else |
| 225 | service = lookup_service(niquery->addr.addr6.sin6_port, |
| 226 | niquery->flags, srvbuf, sizeof(srvbuf)); |
| 227 | } |
| 228 | /* NOFQDN means we have to strip off the domain name portion. We do |
| 229 | this by determining our own domain name, then searching the string |
| 230 | for this domain name and removing it. |
| 231 | */ |
| 232 | #ifdef HAVE_GETHOSTNAME |
| 233 | if (niquery->flags & ARES_NI_NOFQDN) |
| 234 | { |
| 235 | char buf[255]; |
| 236 | char *domain; |
| 237 | gethostname(buf, 255); |
| 238 | if ((domain = strchr(buf, '.')) != NULL) |
| 239 | { |
| 240 | char *end = ares_striendstr(host->h_name, domain); |
| 241 | if (end) |
| 242 | *end = 0; |
| 243 | } |
| 244 | } |
| 245 | #endif |
| 246 | niquery->callback(niquery->arg, ARES_SUCCESS, niquery->timeouts, |
| 247 | (char *)(host->h_name), |
| 248 | service); |
| 249 | free(niquery); |
| 250 | return; |
| 251 | } |
| 252 | /* We couldn't find the host, but it's OK, we can use the IP */ |
| 253 | else if (status == ARES_ENOTFOUND && !(niquery->flags & ARES_NI_NAMEREQD)) |
| 254 | { |
| 255 | char ipbuf[IPBUFSIZ]; |
| 256 | if (niquery->family == AF_INET) |
| 257 | ares_inet_ntop(AF_INET, &niquery->addr.addr4.sin_addr, ipbuf, |
| 258 | IPBUFSIZ); |
| 259 | else |
| 260 | { |
| 261 | ares_inet_ntop(AF_INET6, &niquery->addr.addr6.sin6_addr, ipbuf, |
| 262 | IPBUFSIZ); |
| 263 | #ifdef HAVE_SOCKADDR_IN6_SIN6_SCOPE_ID |
| 264 | append_scopeid(&niquery->addr.addr6, niquery->flags, ipbuf, |
| 265 | sizeof(ipbuf)); |
| 266 | #endif |
| 267 | } |
| 268 | /* They want a service too */ |
| 269 | if (niquery->flags & ARES_NI_LOOKUPSERVICE) |
| 270 | { |
| 271 | if (niquery->family == AF_INET) |
| 272 | service = lookup_service(niquery->addr.addr4.sin_port, |
| 273 | niquery->flags, srvbuf, sizeof(srvbuf)); |
| 274 | else |
| 275 | service = lookup_service(niquery->addr.addr6.sin6_port, |
| 276 | niquery->flags, srvbuf, sizeof(srvbuf)); |
| 277 | } |
| 278 | niquery->callback(niquery->arg, ARES_SUCCESS, niquery->timeouts, ipbuf, |
| 279 | service); |
| 280 | free(niquery); |
| 281 | return; |
| 282 | } |
| 283 | niquery->callback(niquery->arg, status, niquery->timeouts, NULL, NULL); |
| 284 | free(niquery); |
| 285 | } |
| 286 | |
| 287 | static char *lookup_service(unsigned short port, int flags, |
| 288 | char *buf, size_t buflen) |
| 289 | { |
| 290 | const char *proto; |
| 291 | struct servent *sep; |
| 292 | #ifdef HAVE_GETSERVBYPORT_R |
| 293 | struct servent se; |
| 294 | #endif |
| 295 | char tmpbuf[4096]; |
| 296 | |
| 297 | if (port) |
| 298 | { |
| 299 | if (flags & ARES_NI_NUMERICSERV) |
| 300 | sep = NULL; |
| 301 | else |
| 302 | { |
| 303 | if (flags & ARES_NI_UDP) |
| 304 | proto = "udp"; |
| 305 | else if (flags & ARES_NI_SCTP) |
| 306 | proto = "sctp"; |
| 307 | else if (flags & ARES_NI_DCCP) |
| 308 | proto = "dccp"; |
| 309 | else |
| 310 | proto = "tcp"; |
| 311 | #ifdef HAVE_GETSERVBYPORT_R |
| 312 | sep = &se; |
| 313 | memset(tmpbuf, 0, sizeof(tmpbuf)); |
| 314 | #if GETSERVBYPORT_R_ARGS == 6 |
| 315 | if (getservbyport_r(port, proto, &se, (void *)tmpbuf, |
| 316 | sizeof(tmpbuf), &sep) != 0) |
| 317 | sep = NULL; |
| 318 | #elif GETSERVBYPORT_R_ARGS == 5 |
| 319 | sep = getservbyport_r(port, proto, &se, (void *)tmpbuf, |
| 320 | sizeof(tmpbuf)); |
| 321 | #elif GETSERVBYPORT_R_ARGS == 4 |
| 322 | if (getservbyport_r(port, proto, &se, (void *)tmpbuf) != 0) |
| 323 | sep = NULL; |
| 324 | #else |
| 325 | /* Lets just hope the OS uses TLS! */ |
| 326 | sep = getservbyport(port, proto); |
| 327 | #endif |
| 328 | #else |
| 329 | /* Lets just hope the OS uses TLS! */ |
| 330 | #if (defined(NETWARE) && !defined(__NOVELL_LIBC__)) |
| 331 | sep = getservbyport(port, (char*)proto); |
| 332 | #else |
| 333 | sep = getservbyport(port, proto); |
| 334 | #endif |
| 335 | #endif |
| 336 | } |
| 337 | if (sep && sep->s_name) |
| 338 | /* get service name */ |
| 339 | strcpy(tmpbuf, sep->s_name); |
| 340 | else |
| 341 | /* get port as a string */ |
| 342 | sprintf(tmpbuf, "%u", (unsigned int)ntohs(port)); |
| 343 | if (strlen(tmpbuf) < buflen) |
| 344 | /* return it if buffer big enough */ |
| 345 | strcpy(buf, tmpbuf); |
| 346 | else |
| 347 | /* avoid reusing previous one */ |
| 348 | buf[0] = '\0'; |
| 349 | return buf; |
| 350 | } |
| 351 | buf[0] = '\0'; |
| 352 | return NULL; |
| 353 | } |
| 354 | |
| 355 | #ifdef HAVE_SOCKADDR_IN6_SIN6_SCOPE_ID |
| 356 | static void append_scopeid(struct sockaddr_in6 *addr6, unsigned int flags, |
| 357 | char *buf, size_t buflen) |
| 358 | { |
| 359 | #ifdef HAVE_IF_INDEXTONAME |
| 360 | int is_ll, is_mcll; |
| 361 | #endif |
| 362 | static const char fmt_u[] = "%u"; |
| 363 | static const char fmt_lu[] = "%lu"; |
| 364 | char tmpbuf[IF_NAMESIZE + 2]; |
| 365 | size_t bufl; |
| 366 | const char *fmt = (sizeof(addr6->sin6_scope_id) > sizeof(unsigned int))? |
| 367 | fmt_lu:fmt_u; |
| 368 | |
| 369 | tmpbuf[0] = '%'; |
| 370 | |
| 371 | #ifdef HAVE_IF_INDEXTONAME |
| 372 | is_ll = IN6_IS_ADDR_LINKLOCAL(&addr6->sin6_addr); |
| 373 | is_mcll = IN6_IS_ADDR_MC_LINKLOCAL(&addr6->sin6_addr); |
| 374 | if ((flags & ARES_NI_NUMERICSCOPE) || |
| 375 | (!is_ll && !is_mcll)) |
| 376 | { |
| 377 | sprintf(&tmpbuf[1], fmt, addr6->sin6_scope_id); |
| 378 | } |
| 379 | else |
| 380 | { |
| 381 | if (if_indextoname(addr6->sin6_scope_id, &tmpbuf[1]) == NULL) |
| 382 | sprintf(&tmpbuf[1], fmt, addr6->sin6_scope_id); |
| 383 | } |
| 384 | #else |
| 385 | sprintf(&tmpbuf[1], fmt, addr6->sin6_scope_id); |
| 386 | (void) flags; |
| 387 | #endif |
| 388 | tmpbuf[IF_NAMESIZE + 1] = '\0'; |
| 389 | bufl = strlen(buf); |
| 390 | |
| 391 | if(bufl + strlen(tmpbuf) < buflen) |
| 392 | /* only append the scopeid string if it fits in the target buffer */ |
| 393 | strcpy(&buf[bufl], tmpbuf); |
| 394 | } |
| 395 | #endif |
| 396 | |
| 397 | /* Determines if s1 ends with the string in s2 (case-insensitive) */ |
| 398 | static char *ares_striendstr(const char *s1, const char *s2) |
| 399 | { |
| 400 | const char *c1, *c2, *c1_begin; |
| 401 | int lo1, lo2; |
| 402 | size_t s1_len = strlen(s1), s2_len = strlen(s2); |
| 403 | |
| 404 | /* If the substr is longer than the full str, it can't match */ |
| 405 | if (s2_len > s1_len) |
| 406 | return NULL; |
| 407 | |
| 408 | /* Jump to the end of s1 minus the length of s2 */ |
| 409 | c1_begin = s1+s1_len-s2_len; |
| 410 | c1 = (const char *)c1_begin; |
| 411 | c2 = s2; |
| 412 | while (c2 < s2+s2_len) |
| 413 | { |
| 414 | lo1 = TOLOWER(*c1); |
| 415 | lo2 = TOLOWER(*c2); |
| 416 | if (lo1 != lo2) |
| 417 | return NULL; |
| 418 | else |
| 419 | { |
| 420 | c1++; |
| 421 | c2++; |
| 422 | } |
| 423 | } |
| 424 | if (c2 == c1 && c2 == NULL) |
| 425 | return (char *)c1_begin; |
| 426 | return NULL; |
| 427 | } |