/* $KAME: getnameinfo.c,v 1.61 2002/06/27 09:25:47 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:
* - Thread safe-ness must be checked
* - 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.
* - What is "local" in NI_FQDN?
* - 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?
* XXX breaks backward compat for code that expects no scopeid.
* beware on merge.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#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>
static const struct afd {
int a_af;
size_t a_addrlen;
socklen_t a_socklen;
int a_off;
} afdl [] = {
#ifdef INET6
{PF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6),
offsetof(struct sockaddr_in6, sin6_addr)},
#endif
{PF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in),
offsetof(struct sockaddr_in, sin_addr)},
{0, 0, 0},
};
struct sockinet {
u_char si_len;
u_char si_family;
u_short si_port;
};
#ifdef INET6
static int ip6_parsenumeric(const struct sockaddr *, const char *, char *,
size_t, int);
static int ip6_sa2str(const struct sockaddr_in6 *, char *, size_t, int);
#endif
int
getnameinfo(const struct sockaddr *sa, socklen_t salen,
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;
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 */
port = ((const struct sockinet *)sa)->si_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: rfc2553bis-03 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_MEMORY;
strlcpy(serv, sp->s_name, servlen);
} else {
snprintf(numserv, sizeof(numserv), "%u", ntohs(port));
if (strlen(numserv) + 1 > servlen)
return EAI_MEMORY;
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: rfc2553bis-03 says that host == NULL or
* hostlen == 0 means that the caller does not want the result.
*/
} else if (flags & NI_NUMERICHOST) {
size_t numaddrlen;
/* NUMERICHOST and NAMEREQD conflicts with each other */
if (flags & NI_NAMEREQD)
return EAI_NONAME;
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, numaddr, sizeof(numaddr))
== NULL)
return EAI_SYSTEM;
numaddrlen = strlen(numaddr);
if (numaddrlen + 1 > hostlen) /* don't forget terminator */
return EAI_MEMORY;
strlcpy(host, numaddr, hostlen);
break;
}
} else {
hp = getipnodebyaddr(addr, afd->a_addrlen, afd->a_af, &h_error);
if (hp) {
#if 0
/*
* commented out, since "for local host" is not
* implemented here - see RFC2553 p30
*/
if (flags & NI_NOFQDN) {
char *p;
p = strchr(hp->h_name, '.');
if (p)
*p = '\0';
}
#endif
if (strlen(hp->h_name) + 1 > hostlen) {
freehostent(hp);
return EAI_MEMORY;
}
strlcpy(host, hp->h_name, hostlen);
freehostent(hp);
} else {
if (flags & NI_NAMEREQD)
return EAI_NONAME;
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(const struct sockaddr *sa, const char *addr,
char *host, size_t hostlen, int flags)
{
size_t 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_MEMORY;
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_MEMORY;
if (zonelen + 1 + numaddrlen + 1 > hostlen)
return EAI_MEMORY;
/* 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(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 || (size_t)n >= bufsiz)
return -1;
else
return n;
}
#endif /* INET6 */
