/*
* Portions Copyright (C) 1999-2001, 2003-2005, 2007, 2011-2013, 2016 Internet Systems Consortium, Inc. ("ISC")
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*/
/* $Id$ */
/*! \file */
/*
* 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.
*/
/*
* XXX
* Issues to be discussed:
* - Return values. There seems to be no standard for return value (RFC2553)
* but INRIA implementation returns EAI_xxx defined for getaddrinfo().
*/
/**
* This function is equivalent to the getnameinfo(3) function defined in
* RFC2133. lwres_getnameinfo() returns the hostname for the struct
* sockaddr sa which is salen bytes long. The hostname is of length
* hostlen and is returned via *host. The maximum length of the hostname
* is 1025 bytes: #NI_MAXHOST.
*
* The name of the service associated with the port number in sa is
* returned in *serv. It is servlen bytes long. The maximum length of the
* service name is #NI_MAXSERV - 32 bytes.
*
* The flags argument sets the following bits:
*
* \li #NI_NOFQDN:
* A fully qualified domain name is not required for local hosts.
* The local part of the fully qualified domain name is returned
* instead.
*
* \li #NI_NUMERICHOST
* Return the address in numeric form, as if calling inet_ntop(),
* instead of a host name.
*
* \li #NI_NAMEREQD
* A name is required. If the hostname cannot be found in the DNS
* and this flag is set, a non-zero error code is returned. If the
* hostname is not found and the flag is not set, the address is
* returned in numeric form.
*
* \li #NI_NUMERICSERV
* The service name is returned as a digit string representing the
* port number.
*
* \li #NI_DGRAM
* Specifies that the service being looked up is a datagram
* service, and causes getservbyport() to be called with a second
* argument of "udp" instead of its default of "tcp". This is
* required for the few ports (512-514) that have different
* services for UDP and TCP.
*
* \section getnameinfo_return Return Values
*
* lwres_getnameinfo() returns 0 on success or a non-zero error code if
* an error occurs.
*
* \section getname_see See Also
*
* RFC2133, getservbyport(),
* lwres_getnamebyaddr(). lwres_net_ntop().
*
* \section getnameinfo_bugs Bugs
*
* RFC2133 fails to define what the nonzero return values of
* getnameinfo() are.
*/
#include <config.h>
#include <stdio.h>
#include <string.h>
#include <lwres/lwres.h>
#include <lwres/net.h>
#include <lwres/netdb.h>
#include "print_p.h"
#include "assert_p.h"
#define SUCCESS 0
/*% afd structure definition */
static struct afd {
int a_af;
size_t a_addrlen;
size_t a_socklen;
} afdl [] = {
/*!
* First entry is linked last...
*/
{ AF_INET, sizeof(struct in_addr), sizeof(struct sockaddr_in) },
{ AF_INET6, sizeof(struct in6_addr), sizeof(struct sockaddr_in6) },
{0, 0, 0},
};
#define ENI_NOSERVNAME 1
#define ENI_NOHOSTNAME 2
#define ENI_MEMORY 3
#define ENI_SYSTEM 4
#define ENI_FAMILY 5
#define ENI_SALEN 6
#define ENI_NOSOCKET 7
/*!
* The test against 0 is there to keep the Solaris compiler
* from complaining about "end-of-loop code not reached".
*/
#define ERR(code) \
do { result = (code); \
if (result != 0) goto cleanup; \
} while (0)
/*% lightweight resolver socket address structure to hostname and service name */
int
lwres_getnameinfo(const struct sockaddr *sa, size_t salen, char *host,
size_t hostlen, char *serv, size_t servlen, int flags)
{
struct afd *afd = NULL;
struct servent *sp;
unsigned short port;
#ifdef LWRES_PLATFORM_HAVESALEN
size_t len;
#endif
int family, i;
const void *addr;
char *p;
#if 0
unsigned long v4a;
unsigned char pfx;
#endif
char numserv[sizeof("65000")];
char numaddr[sizeof("abcd:abcd:abcd:abcd:abcd:abcd:255.255.255.255")
+ 1 + sizeof("4294967295")];
const char *proto;
lwres_uint32_t lwf = 0;
lwres_context_t *lwrctx = NULL;
lwres_gnbaresponse_t *by = NULL;
int result = SUCCESS;
int n;
if (sa == NULL)
ERR(ENI_NOSOCKET);
#ifdef LWRES_PLATFORM_HAVESALEN
len = sa->sa_len;
if (len != salen)
ERR(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;
}
ERR(ENI_FAMILY);
found:
if (salen != afd->a_socklen)
ERR(ENI_SALEN);
switch (family) {
case AF_INET:
port = ((const struct sockaddr_in *)sa)->sin_port;
addr = &((const struct sockaddr_in *)sa)->sin_addr.s_addr;
break;
case AF_INET6:
port = ((const struct sockaddr_in6 *)sa)->sin6_port;
addr = ((const struct sockaddr_in6 *)sa)->sin6_addr.s6_addr;
break;
default:
port = 0;
addr = NULL;
POST(port); POST(addr);
INSIST(0);
}
proto = (flags & NI_DGRAM) ? "udp" : "tcp";
if (serv == NULL || servlen == 0U) {
/*
* Caller does not want service.
*/
} else if ((flags & NI_NUMERICSERV) != 0 ||
(sp = getservbyport(port, proto)) == NULL) {
snprintf(numserv, sizeof(numserv), "%d", ntohs(port));
if ((strlen(numserv) + 1) > servlen)
ERR(ENI_MEMORY);
strcpy(serv, numserv);
} else {
if ((strlen(sp->s_name) + 1) > servlen)
ERR(ENI_MEMORY);
strcpy(serv, sp->s_name);
}
#if 0
switch (sa->sa_family) {
case AF_INET:
v4a = ((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 || v4a == IN_LOOPBACKNET)
flags |= NI_NUMERICHOST;
break;
case AF_INET6:
pfx = ((struct sockaddr_in6 *)sa)->sin6_addr.s6_addr[0];
if (pfx == 0 || pfx == 0xfe || pfx == 0xff)
flags |= NI_NUMERICHOST;
break;
}
#endif
if (host == NULL || hostlen == 0U) {
/*
* What should we do?
*/
} else if (flags & NI_NUMERICHOST) {
if (lwres_net_ntop(afd->a_af, addr, numaddr, sizeof(numaddr))
== NULL)
ERR(ENI_SYSTEM);
#if defined(LWRES_HAVE_SIN6_SCOPE_ID)
if (afd->a_af == AF_INET6 &&
((const struct sockaddr_in6 *)sa)->sin6_scope_id) {
char *p = numaddr + strlen(numaddr);
const char *stringscope = NULL;
#if 0
if ((flags & NI_NUMERICSCOPE) == 0) {
/*
* Vendors may want to add support for
* non-numeric scope identifier.
*/
stringscope = foo;
}
#endif
if (stringscope == NULL) {
snprintf(p, sizeof(numaddr) - (p - numaddr),
"%%%u",
((const struct sockaddr_in6 *)sa)->sin6_scope_id);
} else {
snprintf(p, sizeof(numaddr) - (p - numaddr),
"%%%s", stringscope);
}
}
#endif
if (strlen(numaddr) + 1 > hostlen)
ERR(ENI_MEMORY);
strcpy(host, numaddr);
} else {
switch (family) {
case AF_INET:
lwf = LWRES_ADDRTYPE_V4;
break;
case AF_INET6:
lwf = LWRES_ADDRTYPE_V6;
break;
default:
INSIST(0);
}
n = lwres_context_create(&lwrctx, NULL, NULL, NULL, 0);
if (n == 0)
(void) lwres_conf_parse(lwrctx, lwres_resolv_conf);
if (n == 0)
n = lwres_getnamebyaddr(lwrctx, lwf,
(lwres_uint16_t)afd->a_addrlen,
addr, &by);
if (n == 0) {
if (flags & NI_NOFQDN) {
p = strchr(by->realname, '.');
if (p)
*p = '\0';
}
if ((strlen(by->realname) + 1) > hostlen)
ERR(ENI_MEMORY);
strcpy(host, by->realname);
} else {
if (flags & NI_NAMEREQD)
ERR(ENI_NOHOSTNAME);
if (lwres_net_ntop(afd->a_af, addr, numaddr,
sizeof(numaddr))
== NULL)
ERR(ENI_NOHOSTNAME);
if ((strlen(numaddr) + 1) > hostlen)
ERR(ENI_MEMORY);
strcpy(host, numaddr);
}
}
result = SUCCESS;
cleanup:
if (by != NULL)
lwres_gnbaresponse_free(lwrctx, &by);
if (lwrctx != NULL) {
lwres_conf_clear(lwrctx);
lwres_context_destroy(&lwrctx);
}
return (result);
}