/* $KAME: getnameinfo.c,v 1.72 2005/01/13 04:12:03 itojun Exp $ */ /* * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the project nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ /* * Issues to be discussed: * - RFC2553 says that we should raise error on short buffer. X/Open says * we need to truncate the result. We obey RFC2553 (and X/Open should be * modified). ipngwg rough consensus seems to follow RFC2553. RFC3493 says * nothing about it, but defines a new error code EAI_OVERFLOW which seems * to be intended the code for this case. * - What is "local" in NI_NOFQDN? (see comments in the code) * - NI_NAMEREQD and NI_NUMERICHOST conflict with each other. * - (KAME extension) always attach textual scopeid (fe80::1%lo0), if * sin6_scope_id is filled - standardization status? * - what should we do if we should do getservbyport("sctp")? */ /* * Considerations about thread-safeness * The code in this file is thread-safe, and so the thread-safeness of * getnameinfo() depends on the property of backend functions. * - getservbyport() is not thread safe for most systems we are targeting. * - getipnodebyaddr() is thread safe. However, many resolver libraries * used in the function are not thread safe. * - gethostbyaddr() is usually not thread safe. */ #ifdef HAVE_CONFIG_H #include #endif #ifndef HAVE_GETNAMEINFO #include #include #include #include #include #include #include #include #include #include #include #ifdef HAVE_INTTYPES_H #include #endif #include "fetchmail.h" #include "getaddrinfo.h" static const struct afd { int a_af; int a_addrlen; int a_socklen; int a_off; int a_portoff; } afdl [] = { #ifdef INET6 {PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6), offsetof(struct sockaddr_in6, sin6_addr), offsetof(struct sockaddr_in6, sin6_port)}, #endif {PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in), offsetof(struct sockaddr_in, sin_addr), offsetof(struct sockaddr_in, sin_port)}, {0, 0, 0, 0, 0}, }; #ifdef INET6 static int ip6_parsenumeric __P((const struct sockaddr *, const char *, char *, size_t, int)); static int ip6_sa2str __P((const struct sockaddr_in6 *, char *, size_t, int)); #endif int getnameinfo(sa, salen, host, hostlen, serv, servlen, flags) const struct sockaddr *sa; #ifdef HAVE_SOCKLEN_T socklen_t salen; #else unsigned int salen; #endif char *host; size_t hostlen; char *serv; size_t servlen; int flags; { const struct afd *afd; struct servent *sp; struct hostent *hp; u_short port; int family, i; const char *addr; u_int32_t v4a; int h_error; char numserv[512]; char numaddr[512]; if (sa == NULL) return EAI_FAIL; #ifdef HAVE_SA_LEN /*XXX*/ if (sa->sa_len != salen) return EAI_FAIL; #endif family = sa->sa_family; for (i = 0; afdl[i].a_af; i++) if (afdl[i].a_af == family) { afd = &afdl[i]; goto found; } return EAI_FAMILY; found: if (salen != afd->a_socklen) return EAI_FAIL; /* network byte order */ memcpy(&port, (const char *)sa + afd->a_portoff, sizeof(port)); addr = (const char *)sa + afd->a_off; if (serv == NULL || servlen == 0) { /* * do nothing in this case. * in case you are wondering if "&&" is more correct than * "||" here: RFC3493 says that serv == NULL OR servlen == 0 * means that the caller does not want the result. */ } else { if (flags & NI_NUMERICSERV) sp = NULL; else { sp = getservbyport(port, (flags & NI_DGRAM) ? "udp" : "tcp"); } if (sp) { if (strlen(sp->s_name) + 1 > servlen) return EAI_OVERFLOW; strlcpy(serv, sp->s_name, servlen); } else { snprintf(numserv, sizeof(numserv), "%u", ntohs(port)); if (strlen(numserv) + 1 > servlen) return EAI_OVERFLOW; strlcpy(serv, numserv, servlen); } } switch (sa->sa_family) { case AF_INET: v4a = (u_int32_t) ntohl(((const struct sockaddr_in *)sa)->sin_addr.s_addr); if (IN_MULTICAST(v4a) || IN_EXPERIMENTAL(v4a)) flags |= NI_NUMERICHOST; v4a >>= IN_CLASSA_NSHIFT; if (v4a == 0) flags |= NI_NUMERICHOST; break; #ifdef INET6 case AF_INET6: { const struct sockaddr_in6 *sin6; sin6 = (const struct sockaddr_in6 *)sa; switch (sin6->sin6_addr.s6_addr[0]) { case 0x00: if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) ; else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr)) ; else flags |= NI_NUMERICHOST; break; default: if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) flags |= NI_NUMERICHOST; else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) flags |= NI_NUMERICHOST; break; } } break; #endif } if (host == NULL || hostlen == 0) { /* * do nothing in this case. * in case you are wondering if "&&" is more correct than * "||" here: RFC3493 says that host == NULL or hostlen == 0 * means that the caller does not want the result. */ } else if (flags & NI_NUMERICHOST) { /* NUMERICHOST and NAMEREQD conflicts with each other */ if (flags & NI_NAMEREQD) return EAI_NONAME; goto numeric; } else { #ifdef USE_GETIPNODEBY hp = getipnodebyaddr(addr, afd->a_addrlen, afd->a_af, &h_error); #else hp = gethostbyaddr(addr, afd->a_addrlen, afd->a_af); #ifdef HAVE_H_ERRNO h_error = h_errno; #else h_error = EINVAL; #endif #endif if (hp) { #if 0 if (flags & NI_NOFQDN) { /* * According to RFC3493 section 6.2, NI_NOFQDN * means "node name portion of the FQDN shall * be returned for local hosts." The following * code tries to implement it by returning the * first label (the part before the first * period) of the FQDN. However, it is not * clear if this always makes sense, since the * given address may be outside of "local * hosts." Due to the unclear description, we * disable the code in this implementation. */ char *p; p = strchr(hp->h_name, '.'); if (p) *p = '\0'; } #endif if (strlen(hp->h_name) + 1 > hostlen) { #ifdef USE_GETIPNODEBY freehostent(hp); #endif return EAI_OVERFLOW; } strlcpy(host, hp->h_name, hostlen); #ifdef USE_GETIPNODEBY freehostent(hp); #endif } else { if (flags & NI_NAMEREQD) return EAI_NONAME; numeric: switch(afd->a_af) { #ifdef INET6 case AF_INET6: { int error; if ((error = ip6_parsenumeric(sa, addr, host, hostlen, flags)) != 0) return(error); break; } #endif default: #ifdef HAVE_INET_NTOP if (inet_ntop(afd->a_af, addr, host, hostlen) == NULL) return EAI_SYSTEM; #else if (afd->a_af == AF_INET) { struct in_addr addr_tmp; addr_tmp.s_addr = addr; strlcpy(host, inet_ntoa(addr_tmp), hostlen); } else return EAI_FAMILY; #endif break; } } } return(0); } #ifdef INET6 static int ip6_parsenumeric(sa, addr, host, hostlen, flags) const struct sockaddr *sa; const char *addr; char *host; size_t hostlen; int flags; { int numaddrlen; char numaddr[512]; if (inet_ntop(AF_INET6, addr, numaddr, sizeof(numaddr)) == NULL) return EAI_SYSTEM; numaddrlen = strlen(numaddr); if (numaddrlen + 1 > hostlen) /* don't forget terminator */ return EAI_OVERFLOW; strlcpy(host, numaddr, hostlen); if (((const struct sockaddr_in6 *)sa)->sin6_scope_id) { char zonebuf[MAXHOSTNAMELEN]; int zonelen; zonelen = ip6_sa2str( (const struct sockaddr_in6 *)(const void *)sa, zonebuf, sizeof(zonebuf), flags); if (zonelen < 0) return EAI_OVERFLOW; if (zonelen + 1 + numaddrlen + 1 > hostlen) return EAI_OVERFLOW; /* construct */ memcpy(host + numaddrlen + 1, zonebuf, (size_t)zonelen); host[numaddrlen] = SCOPE_DELIMITER; host[numaddrlen + 1 + zonelen] = '\0'; } return 0; } /* ARGSUSED */ static int ip6_sa2str(sa6, buf, bufsiz, flags) const struct sockaddr_in6 *sa6; char *buf; size_t bufsiz; int flags; { unsigned int ifindex; const struct in6_addr *a6; int n; ifindex = (unsigned int)sa6->sin6_scope_id; a6 = &sa6->sin6_addr; #ifdef NI_NUMERICSCOPE if ((flags & NI_NUMERICSCOPE) != 0) { n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id); if (n < 0 || n >= bufsiz) return -1; else return n; } #endif /* if_indextoname() does not take buffer size. not a good api... */ if ((IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6) || IN6_IS_ADDR_MC_NODELOCAL(a6)) && bufsiz >= IF_NAMESIZE) { char *p = if_indextoname(ifindex, buf); if (p) return (strlen(p)); } /* last resort */ n = snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id); if (n < 0 || n >= bufsiz) return -1; else return n; } #endif /* INET6 */ #endif