lib/lwres/getnameinfo.c

	getnameinfo.c revision 40f53fa8d9c6a4fc38c0014495e7a42b08f52481
/*
 * Portions Copyright (C) 1999, 2000  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and 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 INTERNET SOFTWARE CONSORTIUM
 * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
 * INTERNET SOFTWARE CONSORTIUM 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 1.25 2000/08/01 01:32:16 tale 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    This product includes software developed by WIDE Project and
 *    its contributors.
 * 4. 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().
 */

#include <config.h>

#include <sys/types.h>
#include <sys/socket.h>

#include <netinet/in.h>

#include <stdio.h>
#include <string.h>

#include <lwres/lwres.h>
#include <lwres/net.h>
#include <lwres/netdb.h>

#include "assert_p.h"

#define SUCCESS 0

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)

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 == 0) {
        /*
         * Caller does not want service.
         */
    } else if ((flags & NI_NUMERICSERV) != 0 ||
           (sp = getservbyport(port, proto)) == NULL) {
        sprintf(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 == 0) {
        /*
         * 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) > 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, "/etc/resolv.conf");

        if (n == 0)
            n = lwres_getnamebyaddr(lwrctx, lwf, 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);
}