diff options
| -rw-r--r-- | KAME/getnameinfo.c | 380 |
1 files changed, 380 insertions, 0 deletions
diff --git a/KAME/getnameinfo.c b/KAME/getnameinfo.c new file mode 100644 index 00000000..9549600c --- /dev/null +++ b/KAME/getnameinfo.c @@ -0,0 +1,380 @@ +/* $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 <config.h> +#endif + +#ifndef HAVE_GETNAMEINFO + +#include <sys/types.h> +#include <sys/socket.h> +#include <net/if.h> +#include <netinet/in.h> +#include <arpa/inet.h> +#include <arpa/nameser.h> +#include <netdb.h> +#include <resolv.h> +#include <string.h> +#include <stddef.h> +#include <errno.h> + +#include <inttypes.h> +#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: + if (inet_ntop(afd->a_af, addr, host, + hostlen) == NULL) + return EAI_SYSTEM; + 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 <numeric-addr><delim><zoneid> */ + 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 |