NetBSD/lib/libc/net/getnameinfo.c

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/* $NetBSD: getnameinfo.c,v 1.27 2001/04/26 19:43:53 kleink Exp $ */
/* $KAME: getnameinfo.c,v 1.45 2000/09/25 22:43:56 itojun Exp $ */
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/*
* 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
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* 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) NI_WITHSCOPEID when called with global address,
* and sin6_scope_id filled
*/
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#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
__RCSID("$NetBSD: getnameinfo.c,v 1.27 2001/04/26 19:43:53 kleink Exp $");
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#endif /* LIBC_SCCS and not lint */
#include "namespace.h"
#include <sys/types.h>
#include <sys/socket.h>
#include <net/if.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <arpa/nameser.h>
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#include <assert.h>
#include <netdb.h>
#include <resolv.h>
#include <stddef.h>
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#include <string.h>
#ifdef __weak_alias
__weak_alias(getnameinfo,_getnameinfo)
#endif
#define SUCCESS 0
#define ANY 0
#define YES 1
#define NO 0
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static const struct afd {
int a_af;
socklen_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 __P((const struct sockaddr *, const char *, char *,
size_t, int));
static int ip6_sa2str __P((const struct sockaddr_in6 *, char *, size_t, int));
#endif
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/* 2553bis: use EAI_xx for getnameinfo */
#define ENI_NOSOCKET EAI_FAIL /*XXX*/
#define ENI_NOSERVNAME EAI_NONAME
#define ENI_NOHOSTNAME EAI_NONAME
#define ENI_MEMORY EAI_MEMORY
#define ENI_SYSTEM EAI_SYSTEM
#define ENI_FAMILY EAI_FAMILY
#define ENI_SALEN EAI_FAMILY
int
getnameinfo(sa, salen, host, hostlen, serv, servlen, flags)
const struct sockaddr *sa;
socklen_t salen;
char *host;
size_t hostlen;
char *serv;
size_t servlen;
int flags;
{
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const struct afd *afd;
struct servent *sp;
struct hostent *hp;
u_short port;
int family, i;
const char *addr;
u_int32_t v4a;
char numserv[512];
char numaddr[512];
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/* sa is checked below */
/* host may be NULL */
/* serv may be NULL */
if (sa == NULL)
return ENI_NOSOCKET;
#ifdef BSD4_4
if (sa->sa_len != salen)
return ENI_SALEN;
#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 ENI_FAMILY;
found:
if (salen != afd->a_socklen)
return ENI_SALEN;
/* network byte order */
port = ((const struct sockinet *)(const void *)sa)->si_port;
addr = (const char *)(const void *)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: RFC2553 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 ENI_MEMORY;
strcpy(serv, sp->s_name);
} else {
snprintf(numserv, sizeof(numserv), "%d", ntohs(port));
if (strlen(numserv) + 1 > servlen)
return ENI_MEMORY;
strcpy(serv, numserv);
}
}
switch (sa->sa_family) {
case AF_INET:
v4a = (u_int32_t)
ntohl(((const struct sockaddr_in *)
(const void *)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 *)(const void *)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: RFC2553 says that host == NULL OR hostlen == 0
* means that the caller does not want the result.
*/
} else if (flags & NI_NUMERICHOST) {
int numaddrlen;
/* NUMERICHOST and NAMEREQD conflicts with each other */
if (flags & NI_NAMEREQD)
return ENI_NOHOSTNAME;
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 ENI_SYSTEM;
numaddrlen = strlen(numaddr);
if (numaddrlen + 1 > hostlen) /* don't forget terminator */
return ENI_MEMORY;
strcpy(host, numaddr);
break;
}
} else {
hp = gethostbyaddr(addr, afd->a_addrlen, afd->a_af);
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) {
return ENI_MEMORY;
}
strcpy(host, hp->h_name);
} else {
if (flags & NI_NAMEREQD)
return ENI_NOHOSTNAME;
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 ENI_SYSTEM;
break;
}
}
}
return SUCCESS;
}
#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];
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_DIAGASSERT(sa != NULL);
_DIAGASSERT(addr != NULL);
_DIAGASSERT(host != NULL);
if (inet_ntop(AF_INET6, addr, numaddr, sizeof(numaddr))
== NULL)
return ENI_SYSTEM;
numaddrlen = strlen(numaddr);
if (numaddrlen + 1 > hostlen) /* don't forget terminator */
return ENI_MEMORY;
strcpy(host, numaddr);
#ifdef NI_WITHSCOPEID
if (((const struct sockaddr_in6 *)(const void *)sa)->sin6_scope_id) {
if (flags & NI_WITHSCOPEID)
{
char scopebuf[MAXHOSTNAMELEN];
int scopelen;
/* ip6_sa2str never fails */
scopelen = ip6_sa2str(
(const struct sockaddr_in6 *)(const void *)sa,
scopebuf, sizeof(scopebuf), 0);
if (scopelen + 1 + numaddrlen + 1 > hostlen)
return ENI_MEMORY;
/*
* construct <numeric-addr><delim><scopeid>
*/
memcpy(host + numaddrlen + 1, scopebuf,
(size_t)scopelen);
host[numaddrlen] = SCOPE_DELIMITER;
host[numaddrlen + 1 + scopelen] = '\0';
}
}
#endif /* NI_WITHSCOPEID */
return 0;
}
/* ARGSUSED */
static int
ip6_sa2str(sa6, buf, bufsiz, flags)
const struct sockaddr_in6 *sa6;
char *buf;
size_t bufsiz;
int flags;
{
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unsigned int ifindex;
const struct in6_addr *a6;
_DIAGASSERT(sa6 != NULL);
_DIAGASSERT(buf != NULL);
ifindex = (unsigned int)sa6->sin6_scope_id;
a6 = &sa6->sin6_addr;
#ifdef notyet
if (flags & NI_NUMERICSCOPE) {
return(snprintf(buf, bufsiz, "%d", sa6->sin6_scope_id));
}
#endif
/* if_indextoname() does not take buffer size. not a good api... */
if ((IN6_IS_ADDR_LINKLOCAL(a6) || IN6_IS_ADDR_MC_LINKLOCAL(a6)) &&
bufsiz >= IF_NAMESIZE) {
char *p = if_indextoname(ifindex, buf);
if (p) {
return(strlen(p));
}
}
/* last resort */
return(snprintf(buf, bufsiz, "%u", sa6->sin6_scope_id));
}
#endif /* INET6 */