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+/*
+ * Portions Copyright (C) 2004, 2005, 2007 Internet Systems Consortium, Inc. ("ISC")
+ * Portions Copyright (C) 1999-2001, 2003 Internet Software Consortium.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+ * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/* $Id: getnameinfo.c,v 1.39 2007/06/19 23:47:22 tbox Exp $ */
+
+/*! \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;
+ 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;
+ 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);
+}
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