getnameinfo.c revision 157119
1100628Sume/* $KAME: getnameinfo.c,v 1.61 2002/06/27 09:25:47 itojun Exp $ */ 262615Sitojun 355163Sshin/* 455163Sshin * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 555163Sshin * All rights reserved. 655163Sshin * 755163Sshin * Redistribution and use in source and binary forms, with or without 855163Sshin * modification, are permitted provided that the following conditions 955163Sshin * are met: 1055163Sshin * 1. Redistributions of source code must retain the above copyright 1155163Sshin * notice, this list of conditions and the following disclaimer. 1255163Sshin * 2. Redistributions in binary form must reproduce the above copyright 1355163Sshin * notice, this list of conditions and the following disclaimer in the 1455163Sshin * documentation and/or other materials provided with the distribution. 1555163Sshin * 3. Neither the name of the project nor the names of its contributors 1655163Sshin * may be used to endorse or promote products derived from this software 1755163Sshin * without specific prior written permission. 1855163Sshin * 1955163Sshin * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 2055163Sshin * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 2155163Sshin * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 2255163Sshin * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 2355163Sshin * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 2455163Sshin * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 2555163Sshin * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2655163Sshin * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2755163Sshin * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 2855163Sshin * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 2955163Sshin * SUCH DAMAGE. 3055163Sshin */ 3155163Sshin 3255163Sshin/* 3355163Sshin * Issues to be discussed: 3455163Sshin * - Thread safe-ness must be checked 3562615Sitojun * - RFC2553 says that we should raise error on short buffer. X/Open says 3662615Sitojun * we need to truncate the result. We obey RFC2553 (and X/Open should be 3766374Sitojun * modified). ipngwg rough consensus seems to follow RFC2553. 3862615Sitojun * - What is "local" in NI_FQDN? 3962615Sitojun * - NI_NAMEREQD and NI_NUMERICHOST conflict with each other. 4099252Sume * - (KAME extension) always attach textual scopeid (fe80::1%lo0), if 4199252Sume * sin6_scope_id is filled - standardization status? 4299252Sume * XXX breaks backward compat for code that expects no scopeid. 4399252Sume * beware on merge. 4455163Sshin */ 4555163Sshin 4692986Sobrien#include <sys/cdefs.h> 4792986Sobrien__FBSDID("$FreeBSD: head/lib/libc/net/getnameinfo.c 157119 2006-03-25 11:46:37Z ume $"); 4892986Sobrien 4955163Sshin#include <sys/types.h> 5055163Sshin#include <sys/socket.h> 5155163Sshin#include <net/if.h> 5255163Sshin#include <netinet/in.h> 5355163Sshin#include <arpa/inet.h> 5455163Sshin#include <arpa/nameser.h> 5555163Sshin#include <netdb.h> 5655163Sshin#include <resolv.h> 5755163Sshin#include <string.h> 5855163Sshin#include <stddef.h> 5962615Sitojun#include <errno.h> 6055163Sshin 61100628Sumestatic const struct afd { 6255163Sshin int a_af; 63145831Sume size_t a_addrlen; 64145831Sume socklen_t a_socklen; 6555163Sshin int a_off; 6655163Sshin} afdl [] = { 6755163Sshin#ifdef INET6 6855163Sshin {PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6), 6955163Sshin offsetof(struct sockaddr_in6, sin6_addr)}, 7055163Sshin#endif 7155163Sshin {PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in), 7255163Sshin offsetof(struct sockaddr_in, sin_addr)}, 7355163Sshin {0, 0, 0}, 7455163Sshin}; 7555163Sshin 7655163Sshinstruct sockinet { 7755163Sshin u_char si_len; 7855163Sshin u_char si_family; 7955163Sshin u_short si_port; 8055163Sshin}; 8155163Sshin 8262615Sitojun#ifdef INET6 8392941Sobrienstatic int ip6_parsenumeric(const struct sockaddr *, const char *, char *, 84100628Sume size_t, int); 8592905Sobrienstatic int ip6_sa2str(const struct sockaddr_in6 *, char *, size_t, int); 8662615Sitojun#endif 8755163Sshin 8855163Sshinint 89157119Sumegetnameinfo(const struct sockaddr *sa, socklen_t salen, 90157119Sume char *host, size_t hostlen, char *serv, size_t servlen, 91157119Sume int flags) 9255163Sshin{ 93100628Sume const struct afd *afd; 9455163Sshin struct servent *sp; 9555163Sshin struct hostent *hp; 9655163Sshin u_short port; 9755163Sshin int family, i; 9862615Sitojun const char *addr; 9962615Sitojun u_int32_t v4a; 10055163Sshin int h_error; 10155163Sshin char numserv[512]; 10255163Sshin char numaddr[512]; 10355163Sshin 10455163Sshin if (sa == NULL) 105100628Sume return EAI_FAIL; 10655163Sshin 10755163Sshin family = sa->sa_family; 10855163Sshin for (i = 0; afdl[i].a_af; i++) 10955163Sshin if (afdl[i].a_af == family) { 11055163Sshin afd = &afdl[i]; 11155163Sshin goto found; 11255163Sshin } 113100628Sume return EAI_FAMILY; 114100628Sume 11555163Sshin found: 11655163Sshin if (salen != afd->a_socklen) 117100628Sume return EAI_FAIL; 118100628Sume 11962615Sitojun /* network byte order */ 12062615Sitojun port = ((const struct sockinet *)sa)->si_port; 12162615Sitojun addr = (const char *)sa + afd->a_off; 12255163Sshin 12355163Sshin if (serv == NULL || servlen == 0) { 12462615Sitojun /* 12562615Sitojun * do nothing in this case. 12662615Sitojun * in case you are wondering if "&&" is more correct than 127100628Sume * "||" here: rfc2553bis-03 says that serv == NULL OR 128100628Sume * servlen == 0 means that the caller does not want the result. 12962615Sitojun */ 13055163Sshin } else { 13155163Sshin if (flags & NI_NUMERICSERV) 13255163Sshin sp = NULL; 13355163Sshin else { 13455163Sshin sp = getservbyport(port, 13555163Sshin (flags & NI_DGRAM) ? "udp" : "tcp"); 13655163Sshin } 13755163Sshin if (sp) { 13866374Sitojun if (strlen(sp->s_name) + 1 > servlen) 139100628Sume return EAI_MEMORY; 140114443Snectar strlcpy(serv, sp->s_name, servlen); 14155163Sshin } else { 142100628Sume snprintf(numserv, sizeof(numserv), "%u", ntohs(port)); 14366374Sitojun if (strlen(numserv) + 1 > servlen) 144100628Sume return EAI_MEMORY; 145114443Snectar strlcpy(serv, numserv, servlen); 14655163Sshin } 14755163Sshin } 14855163Sshin 14955163Sshin switch (sa->sa_family) { 15055163Sshin case AF_INET: 15162615Sitojun v4a = (u_int32_t) 15262615Sitojun ntohl(((const struct sockaddr_in *)sa)->sin_addr.s_addr); 15355163Sshin if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a)) 15455163Sshin flags |= NI_NUMERICHOST; 15555163Sshin v4a >>= IN_CLASSA_NSHIFT; 15656671Sshin if (v4a == 0) 157157119Sume flags |= NI_NUMERICHOST; 15855163Sshin break; 15955163Sshin#ifdef INET6 16055163Sshin case AF_INET6: 16155163Sshin { 16262615Sitojun const struct sockaddr_in6 *sin6; 16362615Sitojun sin6 = (const struct sockaddr_in6 *)sa; 16462615Sitojun switch (sin6->sin6_addr.s6_addr[0]) { 16562615Sitojun case 0x00: 16662615Sitojun if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) 16762615Sitojun ; 16862615Sitojun else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr)) 16962615Sitojun ; 17062615Sitojun else 17162615Sitojun flags |= NI_NUMERICHOST; 17262615Sitojun break; 17362615Sitojun default: 17462615Sitojun if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) { 17562615Sitojun flags |= NI_NUMERICHOST; 17662615Sitojun } 17762615Sitojun else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) 17862615Sitojun flags |= NI_NUMERICHOST; 17962615Sitojun break; 18062615Sitojun } 18155163Sshin } 18255163Sshin break; 18355163Sshin#endif 18455163Sshin } 18555163Sshin if (host == NULL || hostlen == 0) { 18662615Sitojun /* 18762615Sitojun * do nothing in this case. 18862615Sitojun * in case you are wondering if "&&" is more correct than 189100628Sume * "||" here: rfc2553bis-03 says that host == NULL or 190100628Sume * hostlen == 0 means that the caller does not want the result. 19162615Sitojun */ 19255163Sshin } else if (flags & NI_NUMERICHOST) { 193145831Sume size_t numaddrlen; 19462615Sitojun 19555163Sshin /* NUMERICHOST and NAMEREQD conflicts with each other */ 19655163Sshin if (flags & NI_NAMEREQD) 197100628Sume return EAI_NONAME; 19862615Sitojun 19962615Sitojun switch(afd->a_af) { 20055163Sshin#ifdef INET6 20162615Sitojun case AF_INET6: 20262615Sitojun { 20362615Sitojun int error; 20455163Sshin 20562615Sitojun if ((error = ip6_parsenumeric(sa, addr, host, 20662615Sitojun hostlen, flags)) != 0) 20762615Sitojun return(error); 20862615Sitojun break; 20955163Sshin } 21062615Sitojun#endif 21162615Sitojun default: 21262615Sitojun if (inet_ntop(afd->a_af, addr, numaddr, sizeof(numaddr)) 21362615Sitojun == NULL) 214100628Sume return EAI_SYSTEM; 21562615Sitojun numaddrlen = strlen(numaddr); 21662615Sitojun if (numaddrlen + 1 > hostlen) /* don't forget terminator */ 217100628Sume return EAI_MEMORY; 218114443Snectar strlcpy(host, numaddr, hostlen); 21962615Sitojun break; 22062615Sitojun } 22155163Sshin } else { 22255163Sshin hp = getipnodebyaddr(addr, afd->a_addrlen, afd->a_af, &h_error); 22362615Sitojun 22455163Sshin if (hp) { 22562615Sitojun#if 0 22662615Sitojun /* 22762615Sitojun * commented out, since "for local host" is not 22862615Sitojun * implemented here - see RFC2553 p30 22962615Sitojun */ 23055163Sshin if (flags & NI_NOFQDN) { 23162615Sitojun char *p; 23255163Sshin p = strchr(hp->h_name, '.'); 23362615Sitojun if (p) 23462615Sitojun *p = '\0'; 23555163Sshin } 23662615Sitojun#endif 23766374Sitojun if (strlen(hp->h_name) + 1 > hostlen) { 23855163Sshin freehostent(hp); 239100628Sume return EAI_MEMORY; 24055163Sshin } 241114443Snectar strlcpy(host, hp->h_name, hostlen); 24255163Sshin freehostent(hp); 24355163Sshin } else { 24455163Sshin if (flags & NI_NAMEREQD) 245100628Sume return EAI_NONAME; 24662615Sitojun switch(afd->a_af) { 24762615Sitojun#ifdef INET6 24862615Sitojun case AF_INET6: 24962615Sitojun { 25062615Sitojun int error; 25162615Sitojun 25262615Sitojun if ((error = ip6_parsenumeric(sa, addr, host, 25362615Sitojun hostlen, 25462615Sitojun flags)) != 0) 25562615Sitojun return(error); 25662615Sitojun break; 25762615Sitojun } 25862615Sitojun#endif 25962615Sitojun default: 26062615Sitojun if (inet_ntop(afd->a_af, addr, host, 26162615Sitojun hostlen) == NULL) 262100628Sume return EAI_SYSTEM; 26362615Sitojun break; 26462615Sitojun } 26555163Sshin } 26655163Sshin } 267100628Sume return(0); 26855163Sshin} 26962615Sitojun 27062615Sitojun#ifdef INET6 27162615Sitojunstatic int 272157119Sumeip6_parsenumeric(const struct sockaddr *sa, const char *addr, 273157119Sume char *host, size_t hostlen, int flags) 27462615Sitojun{ 275145831Sume size_t numaddrlen; 27662615Sitojun char numaddr[512]; 27762615Sitojun 278100628Sume if (inet_ntop(AF_INET6, addr, numaddr, sizeof(numaddr)) == NULL) 279100628Sume return EAI_SYSTEM; 28062615Sitojun 28162615Sitojun numaddrlen = strlen(numaddr); 28262615Sitojun if (numaddrlen + 1 > hostlen) /* don't forget terminator */ 283100628Sume return EAI_MEMORY; 284114443Snectar strlcpy(host, numaddr, hostlen); 28562615Sitojun 28699252Sume if (((const struct sockaddr_in6 *)sa)->sin6_scope_id) { 28799252Sume char zonebuf[MAXHOSTNAMELEN]; 28899252Sume int zonelen; 28962615Sitojun 29099252Sume zonelen = ip6_sa2str( 29199252Sume (const struct sockaddr_in6 *)(const void *)sa, 29299252Sume zonebuf, sizeof(zonebuf), flags); 29399252Sume if (zonelen < 0) 29499252Sume return EAI_MEMORY; 29599252Sume if (zonelen + 1 + numaddrlen + 1 > hostlen) 296100628Sume return EAI_MEMORY; 297100628Sume 298100628Sume /* construct <numeric-addr><delim><zoneid> */ 29999252Sume memcpy(host + numaddrlen + 1, zonebuf, 300100628Sume (size_t)zonelen); 30199252Sume host[numaddrlen] = SCOPE_DELIMITER; 30299252Sume host[numaddrlen + 1 + zonelen] = '\0'; 30362615Sitojun } 30462615Sitojun 30562615Sitojun return 0; 30662615Sitojun} 30762615Sitojun 30862615Sitojun/* ARGSUSED */ 30962615Sitojunstatic int 310157119Sumeip6_sa2str(const struct sockaddr_in6 *sa6, char *buf, size_t bufsiz, int flags) 31162615Sitojun{ 312100628Sume unsigned int ifindex; 313100628Sume const struct in6_addr *a6; 314100628Sume int n; 31562615Sitojun 316100628Sume ifindex = (unsigned int)sa6->sin6_scope_id; 317100628Sume a6 = &sa6->sin6_addr; 318100628Sume 31962615Sitojun#ifdef NI_NUMERICSCOPE 320100628Sume if ((flags & NI_NUMERICSCOPE) != 0) { 321100628Sume n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id); 322100628Sume if (n < 0 || n >= bufsiz) 323100628Sume return -1; 324100628Sume else 325100628Sume return n; 32662615Sitojun } 32762615Sitojun#endif 32862615Sitojun 32962615Sitojun /* if_indextoname() does not take buffer size. not a good api... */ 330100628Sume if ((IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6) || 331100628Sume IN6_IS_ADDR_MC_NODELOCAL(a6)) && bufsiz >= IF_NAMESIZE) { 33262615Sitojun char *p = if_indextoname(ifindex, buf); 33362615Sitojun if (p) { 33462615Sitojun return(strlen(p)); 33562615Sitojun } 33662615Sitojun } 33762615Sitojun 33862615Sitojun /* last resort */ 339100628Sume n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id); 340145831Sume if (n < 0 || (size_t)n >= bufsiz) 341100628Sume return -1; 342100628Sume else 343100628Sume return n; 34462615Sitojun} 34562615Sitojun#endif /* INET6 */ 346