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| -rw-r--r-- | src/lib/libc/net/getaddrinfo.3 | 469 |
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diff --git a/src/lib/libc/net/getaddrinfo.3 b/src/lib/libc/net/getaddrinfo.3 deleted file mode 100644 index af3df3c2f6..0000000000 --- a/src/lib/libc/net/getaddrinfo.3 +++ /dev/null | |||
| @@ -1,469 +0,0 @@ | |||
| 1 | .\" $OpenBSD: getaddrinfo.3,v 1.50 2012/04/20 16:37:07 sthen Exp $ | ||
| 2 | .\" $KAME: getaddrinfo.3,v 1.36 2005/01/05 03:23:05 itojun Exp $ | ||
| 3 | .\" | ||
| 4 | .\" Copyright (C) 2004 Internet Systems Consortium, Inc. ("ISC") | ||
| 5 | .\" Copyright (C) 2000, 2001 Internet Software Consortium. | ||
| 6 | .\" | ||
| 7 | .\" Permission to use, copy, modify, and distribute this software for any | ||
| 8 | .\" purpose with or without fee is hereby granted, provided that the above | ||
| 9 | .\" copyright notice and this permission notice appear in all copies. | ||
| 10 | .\" | ||
| 11 | .\" THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH | ||
| 12 | .\" REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY | ||
| 13 | .\" AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, | ||
| 14 | .\" INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM | ||
| 15 | .\" LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE | ||
| 16 | .\" OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR | ||
| 17 | .\" PERFORMANCE OF THIS SOFTWARE. | ||
| 18 | .\" | ||
| 19 | .Dd $Mdocdate: April 20 2012 $ | ||
| 20 | .Dt GETADDRINFO 3 | ||
| 21 | .Os | ||
| 22 | .Sh NAME | ||
| 23 | .Nm getaddrinfo , | ||
| 24 | .Nm freeaddrinfo | ||
| 25 | .Nd host and service name to socket address structure | ||
| 26 | .Sh SYNOPSIS | ||
| 27 | .Fd #include <sys/types.h> | ||
| 28 | .Fd #include <sys/socket.h> | ||
| 29 | .Fd #include <netdb.h> | ||
| 30 | .Ft int | ||
| 31 | .Fn getaddrinfo "const char *hostname" "const char *servname" \ | ||
| 32 | "const struct addrinfo *hints" "struct addrinfo **res" | ||
| 33 | .Ft void | ||
| 34 | .Fn freeaddrinfo "struct addrinfo *ai" | ||
| 35 | .Sh DESCRIPTION | ||
| 36 | The | ||
| 37 | .Fn getaddrinfo | ||
| 38 | function is used to get a list of | ||
| 39 | .Tn IP | ||
| 40 | addresses and port numbers for host | ||
| 41 | .Fa hostname | ||
| 42 | and service | ||
| 43 | .Fa servname . | ||
| 44 | It is a replacement for and provides more flexibility than the | ||
| 45 | .Xr gethostbyname 3 | ||
| 46 | and | ||
| 47 | .Xr getservbyname 3 | ||
| 48 | functions. | ||
| 49 | .Pp | ||
| 50 | The | ||
| 51 | .Fa hostname | ||
| 52 | and | ||
| 53 | .Fa servname | ||
| 54 | arguments are either pointers to NUL-terminated strings or the null pointer. | ||
| 55 | An acceptable value for | ||
| 56 | .Fa hostname | ||
| 57 | is either a valid host name or a numeric host address string consisting | ||
| 58 | of a dotted decimal IPv4 address or an IPv6 address. | ||
| 59 | The | ||
| 60 | .Fa servname | ||
| 61 | is either a decimal port number or a service name listed in | ||
| 62 | .Xr services 5 . | ||
| 63 | At least one of | ||
| 64 | .Fa hostname | ||
| 65 | and | ||
| 66 | .Fa servname | ||
| 67 | must be non-null. | ||
| 68 | .Pp | ||
| 69 | .Fa hints | ||
| 70 | is an optional pointer to a | ||
| 71 | .Li struct addrinfo , | ||
| 72 | as defined by | ||
| 73 | .Aq Pa netdb.h : | ||
| 74 | .Bd -literal | ||
| 75 | struct addrinfo { | ||
| 76 | int ai_flags; /* input flags */ | ||
| 77 | int ai_family; /* protocol family for socket */ | ||
| 78 | int ai_socktype; /* socket type */ | ||
| 79 | int ai_protocol; /* protocol for socket */ | ||
| 80 | socklen_t ai_addrlen; /* length of socket-address */ | ||
| 81 | struct sockaddr *ai_addr; /* socket-address for socket */ | ||
| 82 | char *ai_canonname; /* canonical name for service location */ | ||
| 83 | struct addrinfo *ai_next; /* pointer to next in list */ | ||
| 84 | }; | ||
| 85 | .Ed | ||
| 86 | .Pp | ||
| 87 | This structure can be used to provide hints concerning the type of socket | ||
| 88 | that the caller supports or wishes to use. | ||
| 89 | The caller can supply the following structure elements in | ||
| 90 | .Fa hints : | ||
| 91 | .Bl -tag -width "ai_socktypeXX" | ||
| 92 | .It Fa ai_family | ||
| 93 | The protocol family that should be used. | ||
| 94 | When | ||
| 95 | .Fa ai_family | ||
| 96 | is set to | ||
| 97 | .Dv PF_UNSPEC , | ||
| 98 | it means the caller will accept any protocol family supported by the | ||
| 99 | operating system. | ||
| 100 | .It Fa ai_socktype | ||
| 101 | Denotes the type of socket that is wanted: | ||
| 102 | .Dv SOCK_STREAM , | ||
| 103 | .Dv SOCK_DGRAM , | ||
| 104 | or | ||
| 105 | .Dv SOCK_RAW . | ||
| 106 | When | ||
| 107 | .Fa ai_socktype | ||
| 108 | is zero the caller will accept any socket type. | ||
| 109 | .It Fa ai_protocol | ||
| 110 | Indicates which transport protocol is desired, | ||
| 111 | .Dv IPPROTO_UDP | ||
| 112 | or | ||
| 113 | .Dv IPPROTO_TCP . | ||
| 114 | If | ||
| 115 | .Fa ai_protocol | ||
| 116 | is zero the caller will accept any protocol. | ||
| 117 | .It Fa ai_flags | ||
| 118 | .Fa ai_flags | ||
| 119 | is formed by | ||
| 120 | .Tn OR Ns 'ing | ||
| 121 | the following values: | ||
| 122 | .Bl -tag -width "AI_CANONNAMEXX" | ||
| 123 | .It Dv AI_CANONNAME | ||
| 124 | If the | ||
| 125 | .Dv AI_CANONNAME | ||
| 126 | bit is set, a successful call to | ||
| 127 | .Fn getaddrinfo | ||
| 128 | will return a NUL-terminated string containing the canonical name | ||
| 129 | of the specified host name in the | ||
| 130 | .Fa ai_canonname | ||
| 131 | element of the first | ||
| 132 | .Li addrinfo | ||
| 133 | structure returned. | ||
| 134 | .It Dv AI_FQDN | ||
| 135 | If the | ||
| 136 | .Dv AI_FQDN | ||
| 137 | bit is set, a successful call to | ||
| 138 | .Fn getaddrinfo | ||
| 139 | will return a NUL-terminated string containing the fully qualified domain name | ||
| 140 | of the specified host name in the | ||
| 141 | .Fa ai_canonname | ||
| 142 | element of the first | ||
| 143 | .Li addrinfo | ||
| 144 | structure returned. | ||
| 145 | .Pp | ||
| 146 | This is different from the | ||
| 147 | .Dv AI_CANONNAME | ||
| 148 | bit flag that returns the canonical name registered in DNS, | ||
| 149 | which may be different from the fully qualified domain name | ||
| 150 | that the host name resolved to. | ||
| 151 | Only one of the | ||
| 152 | .Dv AI_FQDN | ||
| 153 | and | ||
| 154 | .Dv AI_CANONNAME | ||
| 155 | bits can be set. | ||
| 156 | .It Dv AI_NUMERICHOST | ||
| 157 | If the | ||
| 158 | .Dv AI_NUMERICHOST | ||
| 159 | bit is set, it indicates that | ||
| 160 | .Fa hostname | ||
| 161 | should be treated as a numeric string defining an IPv4 or IPv6 address | ||
| 162 | and no name resolution should be attempted. | ||
| 163 | .It Dv AI_NUMERICSERV | ||
| 164 | If the | ||
| 165 | .Dv AI_NUMERICSERV | ||
| 166 | bit is set, it indicates that | ||
| 167 | .Fa servname | ||
| 168 | should be treated as a numeric port string | ||
| 169 | and no service name resolution should be attempted. | ||
| 170 | .It Dv AI_PASSIVE | ||
| 171 | If the | ||
| 172 | .Dv AI_PASSIVE | ||
| 173 | bit is set it indicates that the returned socket address structure | ||
| 174 | is intended for use in a call to | ||
| 175 | .Xr bind 2 . | ||
| 176 | In this case, if the | ||
| 177 | .Fa hostname | ||
| 178 | argument is the null pointer, then the IP address portion of the | ||
| 179 | socket address structure will be set to | ||
| 180 | .Dv INADDR_ANY | ||
| 181 | for an IPv4 address or | ||
| 182 | .Dv IN6ADDR_ANY_INIT | ||
| 183 | for an IPv6 address. | ||
| 184 | .Pp | ||
| 185 | If the | ||
| 186 | .Dv AI_PASSIVE | ||
| 187 | bit is not set, the returned socket address structure will be ready | ||
| 188 | for use in a call to | ||
| 189 | .Xr connect 2 | ||
| 190 | for a connection-oriented protocol or | ||
| 191 | .Xr connect 2 , | ||
| 192 | .Xr sendto 2 , | ||
| 193 | or | ||
| 194 | .Xr sendmsg 2 | ||
| 195 | if a connectionless protocol was chosen. | ||
| 196 | The | ||
| 197 | .Tn IP | ||
| 198 | address portion of the socket address structure will be set to the | ||
| 199 | loopback address if | ||
| 200 | .Fa hostname | ||
| 201 | is the null pointer and | ||
| 202 | .Dv AI_PASSIVE | ||
| 203 | is not set. | ||
| 204 | .El | ||
| 205 | .El | ||
| 206 | .Pp | ||
| 207 | All other elements of the | ||
| 208 | .Li addrinfo | ||
| 209 | structure passed via | ||
| 210 | .Fa hints | ||
| 211 | must be zero or the null pointer. | ||
| 212 | .Pp | ||
| 213 | If | ||
| 214 | .Fa hints | ||
| 215 | is the null pointer, | ||
| 216 | .Fn getaddrinfo | ||
| 217 | behaves as if the caller provided a | ||
| 218 | .Li struct addrinfo | ||
| 219 | with | ||
| 220 | .Fa ai_family | ||
| 221 | set to | ||
| 222 | .Dv PF_UNSPEC | ||
| 223 | and all other elements set to zero or | ||
| 224 | .Dv NULL . | ||
| 225 | .Pp | ||
| 226 | After a successful call to | ||
| 227 | .Fn getaddrinfo , | ||
| 228 | .Fa *res | ||
| 229 | is a pointer to a linked list of one or more | ||
| 230 | .Li addrinfo | ||
| 231 | structures. | ||
| 232 | The list can be traversed by following the | ||
| 233 | .Fa ai_next | ||
| 234 | pointer in each | ||
| 235 | .Li addrinfo | ||
| 236 | structure until a null pointer is encountered. | ||
| 237 | The three members | ||
| 238 | .Fa ai_family , | ||
| 239 | .Fa ai_socktype , | ||
| 240 | and | ||
| 241 | .Fa ai_protocol | ||
| 242 | in each returned | ||
| 243 | .Li addrinfo | ||
| 244 | structure are suitable for a call to | ||
| 245 | .Xr socket 2 . | ||
| 246 | For each | ||
| 247 | .Li addrinfo | ||
| 248 | structure in the list, the | ||
| 249 | .Fa ai_addr | ||
| 250 | member points to a filled-in socket address structure of length | ||
| 251 | .Fa ai_addrlen . | ||
| 252 | .Pp | ||
| 253 | This implementation of | ||
| 254 | .Fn getaddrinfo | ||
| 255 | allows numeric IPv6 address notation with scope identifier, | ||
| 256 | as documented in RFC 4007. | ||
| 257 | By appending the percent character and scope identifier to addresses, | ||
| 258 | one can fill the | ||
| 259 | .Li sin6_scope_id | ||
| 260 | field for addresses. | ||
| 261 | This would make management of scoped addresses easier | ||
| 262 | and allows cut-and-paste input of scoped addresses. | ||
| 263 | .Pp | ||
| 264 | At this moment the code supports only link-local addresses with the format. | ||
| 265 | The scope identifier is hardcoded to the name of the hardware interface | ||
| 266 | associated | ||
| 267 | with the link | ||
| 268 | .Po | ||
| 269 | such as | ||
| 270 | .Li ne0 | ||
| 271 | .Pc . | ||
| 272 | An example is | ||
| 273 | .Dq Li fe80::1%ne0 , | ||
| 274 | which means | ||
| 275 | .Do | ||
| 276 | .Li fe80::1 | ||
| 277 | on the link associated with the | ||
| 278 | .Li ne0 | ||
| 279 | interface | ||
| 280 | .Dc . | ||
| 281 | .Pp | ||
| 282 | The current implementation assumes a one-to-one relationship between | ||
| 283 | the interface and link, which is not necessarily true from the specification. | ||
| 284 | .Pp | ||
| 285 | All of the information returned by | ||
| 286 | .Fn getaddrinfo | ||
| 287 | is dynamically allocated: the | ||
| 288 | .Li addrinfo | ||
| 289 | structures themselves as well as the socket address structures and | ||
| 290 | the canonical host name strings included in the | ||
| 291 | .Li addrinfo | ||
| 292 | structures. | ||
| 293 | .Pp | ||
| 294 | Memory allocated for the dynamically allocated structures created by | ||
| 295 | a successful call to | ||
| 296 | .Fn getaddrinfo | ||
| 297 | is released by the | ||
| 298 | .Fn freeaddrinfo | ||
| 299 | function. | ||
| 300 | The | ||
| 301 | .Fa ai | ||
| 302 | pointer should be an | ||
| 303 | .Li addrinfo | ||
| 304 | structure created by a call to | ||
| 305 | .Fn getaddrinfo . | ||
| 306 | .Sh RETURN VALUES | ||
| 307 | .Fn getaddrinfo | ||
| 308 | returns zero on success or one of the error codes listed in | ||
| 309 | .Xr gai_strerror 3 | ||
| 310 | if an error occurs. | ||
| 311 | If an error occurs, no memory is allocated by | ||
| 312 | .Fn getaddrinfo , | ||
| 313 | therefore it is not necessary to release the | ||
| 314 | .Li addrinfo | ||
| 315 | structure(s). | ||
| 316 | .Sh EXAMPLES | ||
| 317 | The following code tries to connect to | ||
| 318 | .Dq Li www.kame.net | ||
| 319 | service | ||
| 320 | .Dq Li www | ||
| 321 | via a stream socket. | ||
| 322 | It loops through all the addresses available, regardless of address family. | ||
| 323 | If the destination resolves to an IPv4 address, it will use an | ||
| 324 | .Dv AF_INET | ||
| 325 | socket. | ||
| 326 | Similarly, if it resolves to IPv6, an | ||
| 327 | .Dv AF_INET6 | ||
| 328 | socket is used. | ||
| 329 | Observe that there is no hardcoded reference to a particular address family. | ||
| 330 | The code works even if | ||
| 331 | .Fn getaddrinfo | ||
| 332 | returns addresses that are not IPv4/v6. | ||
| 333 | .Bd -literal -offset indent | ||
| 334 | struct addrinfo hints, *res, *res0; | ||
| 335 | int error; | ||
| 336 | int save_errno; | ||
| 337 | int s; | ||
| 338 | const char *cause = NULL; | ||
| 339 | |||
| 340 | memset(&hints, 0, sizeof(hints)); | ||
| 341 | hints.ai_family = PF_UNSPEC; | ||
| 342 | hints.ai_socktype = SOCK_STREAM; | ||
| 343 | error = getaddrinfo("www.kame.net", "www", &hints, &res0); | ||
| 344 | if (error) | ||
| 345 | errx(1, "%s", gai_strerror(error)); | ||
| 346 | s = -1; | ||
| 347 | for (res = res0; res; res = res->ai_next) { | ||
| 348 | s = socket(res->ai_family, res->ai_socktype, | ||
| 349 | res->ai_protocol); | ||
| 350 | if (s == -1) { | ||
| 351 | cause = "socket"; | ||
| 352 | continue; | ||
| 353 | } | ||
| 354 | |||
| 355 | if (connect(s, res->ai_addr, res->ai_addrlen) == -1) { | ||
| 356 | cause = "connect"; | ||
| 357 | save_errno = errno; | ||
| 358 | close(s); | ||
| 359 | errno = save_errno; | ||
| 360 | s = -1; | ||
| 361 | continue; | ||
| 362 | } | ||
| 363 | |||
| 364 | break; /* okay we got one */ | ||
| 365 | } | ||
| 366 | if (s == -1) | ||
| 367 | err(1, "%s", cause); | ||
| 368 | freeaddrinfo(res0); | ||
| 369 | .Ed | ||
| 370 | .Pp | ||
| 371 | The following example tries to open a wildcard listening socket onto service | ||
| 372 | .Dq Li www , | ||
| 373 | for all the address families available. | ||
| 374 | .Bd -literal -offset indent | ||
| 375 | struct addrinfo hints, *res, *res0; | ||
| 376 | int error; | ||
| 377 | int save_errno; | ||
| 378 | int s[MAXSOCK]; | ||
| 379 | int nsock; | ||
| 380 | const char *cause = NULL; | ||
| 381 | |||
| 382 | memset(&hints, 0, sizeof(hints)); | ||
| 383 | hints.ai_family = PF_UNSPEC; | ||
| 384 | hints.ai_socktype = SOCK_STREAM; | ||
| 385 | hints.ai_flags = AI_PASSIVE; | ||
| 386 | error = getaddrinfo(NULL, "www", &hints, &res0); | ||
| 387 | if (error) | ||
| 388 | errx(1, "%s", gai_strerror(error)); | ||
| 389 | nsock = 0; | ||
| 390 | for (res = res0; res && nsock < MAXSOCK; res = res->ai_next) { | ||
| 391 | s[nsock] = socket(res->ai_family, res->ai_socktype, | ||
| 392 | res->ai_protocol); | ||
| 393 | if (s[nsock] == -1) { | ||
| 394 | cause = "socket"; | ||
| 395 | continue; | ||
| 396 | } | ||
| 397 | |||
| 398 | if (bind(s[nsock], res->ai_addr, res->ai_addrlen) == -1) { | ||
| 399 | cause = "bind"; | ||
| 400 | save_errno = errno; | ||
| 401 | close(s[nsock]); | ||
| 402 | errno = save_errno; | ||
| 403 | continue; | ||
| 404 | } | ||
| 405 | (void) listen(s[nsock], 5); | ||
| 406 | |||
| 407 | nsock++; | ||
| 408 | } | ||
| 409 | if (nsock == 0) | ||
| 410 | err(1, "%s", cause); | ||
| 411 | freeaddrinfo(res0); | ||
| 412 | .Ed | ||
| 413 | .Sh SEE ALSO | ||
| 414 | .Xr bind 2 , | ||
| 415 | .Xr connect 2 , | ||
| 416 | .Xr send 2 , | ||
| 417 | .Xr socket 2 , | ||
| 418 | .Xr gai_strerror 3 , | ||
| 419 | .Xr gethostbyname 3 , | ||
| 420 | .Xr getnameinfo 3 , | ||
| 421 | .Xr getservbyname 3 , | ||
| 422 | .Xr resolver 3 , | ||
| 423 | .Xr hosts 5 , | ||
| 424 | .Xr resolv.conf 5 , | ||
| 425 | .Xr services 5 , | ||
| 426 | .Xr hostname 7 , | ||
| 427 | .Xr named 8 | ||
| 428 | .Rs | ||
| 429 | .%A R. Gilligan | ||
| 430 | .%A S. Thomson | ||
| 431 | .%A J. Bound | ||
| 432 | .%A J. McCann | ||
| 433 | .%A W. Stevens | ||
| 434 | .%T Basic Socket Interface Extensions for IPv6 | ||
| 435 | .%R RFC 3493 | ||
| 436 | .%D February 2003 | ||
| 437 | .Re | ||
| 438 | .Rs | ||
| 439 | .%A S. Deering | ||
| 440 | .%A B. Haberman | ||
| 441 | .%A T. Jinmei | ||
| 442 | .%A E. Nordmark | ||
| 443 | .%A B. Zill | ||
| 444 | .%T "IPv6 Scoped Address Architecture" | ||
| 445 | .%R RFC 4007 | ||
| 446 | .%D March 2005 | ||
| 447 | .Re | ||
| 448 | .Rs | ||
| 449 | .%A Craig Metz | ||
| 450 | .%T Protocol Independence Using the Sockets API | ||
| 451 | .%B "Proceedings of the Freenix Track: 2000 USENIX Annual Technical Conference" | ||
| 452 | .%D June 2000 | ||
| 453 | .Re | ||
| 454 | .Sh STANDARDS | ||
| 455 | The | ||
| 456 | .Fn getaddrinfo | ||
| 457 | function is defined by the | ||
| 458 | .St -p1003.1g-2000 | ||
| 459 | draft specification and documented in | ||
| 460 | .Dv "RFC 3493" , | ||
| 461 | .Dq Basic Socket Interface Extensions for IPv6 . | ||
| 462 | .Pp | ||
| 463 | The | ||
| 464 | .Dv AI_FQDN | ||
| 465 | flag bit first appeared in Windows 7. | ||
| 466 | .Sh BUGS | ||
| 467 | The implementation of | ||
| 468 | .Fn getaddrinfo | ||
| 469 | is not thread-safe. | ||
