source: rtems/cpukit/libnetworking/libc/gethostnamadr.c @ b2b143f4

/*-
 * Copyright (c) 1994, Garrett Wollman
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE 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 REGENTS 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.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)$Id$";
static char rcsid[] = "$Id$";
#endif /* LIBC_SCCS and not lint */

/* Since we compile with strict ANSI we need to undef it to get
 * prototypes for extensions
 */
#undef __STRICT_ANSI__

#include <sys/param.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <stdio.h>
#include <ctype.h>
#include <errno.h>
#include <string.h>
#include <arpa/nameser.h>               /* XXX hack for _res */
#include <resolv.h>                     /* XXX hack for _res */

#define _PATH_HOSTCONF  "/etc/host.conf"

enum service_type {
  SERVICE_NONE = 0,
  SERVICE_BIND,
  SERVICE_HOSTS,
  SERVICE_NIS };
#define SERVICE_MAX     SERVICE_NIS

static struct {
  const char *name;
  enum service_type type;
} service_names[] = {
  { "hosts", SERVICE_HOSTS },
  { "/etc/hosts", SERVICE_HOSTS },
  { "hosttable", SERVICE_HOSTS },
  { "htable", SERVICE_HOSTS },
  { "bind", SERVICE_BIND },
  { "dns", SERVICE_BIND },
  { "domain", SERVICE_BIND },
  { "yp", SERVICE_NIS },
  { "yellowpages", SERVICE_NIS },
  { "nis", SERVICE_NIS },
  { 0, SERVICE_NONE }
};

static enum service_type service_order[SERVICE_MAX + 1];
static int service_done = 0;

static enum service_type
get_service_name(const char *name) {
        int i;
        for(i = 0; service_names[i].type != SERVICE_NONE; i++) {
                if(!strcasecmp(name, service_names[i].name)) {
                        return service_names[i].type;
                }
        }
        return SERVICE_NONE;
}

static void
init_services()
{
        char *cp, *p, buf[BUFSIZ];
        register int cc = 0;
        FILE *fd;

        if ((fd = (FILE *)fopen(_PATH_HOSTCONF, "r")) == NULL) {
                                /* make some assumptions */
                service_order[0] = SERVICE_BIND;
                service_order[1] = SERVICE_HOSTS;
                service_order[2] = SERVICE_NONE;
        } else {
                while (fgets(buf, BUFSIZ, fd) != NULL && cc < SERVICE_MAX) {
                        if(buf[0] == '#')
                                continue;

                        p = buf;
                        while ((cp = strsep(&p, "\n \t,:;")) != NULL && *cp == '\0')
                                ;
                        if (cp == NULL)
                                continue;
                        do {
                                if (isalpha((int)cp[0])) {
                                        service_order[cc] = get_service_name(cp);
                                        if(service_order[cc] != SERVICE_NONE)
                                                cc++;
                                }
                                while ((cp = strsep(&p, "\n \t,:;")) != NULL && *cp == '\0')
                                        ;
                        } while(cp != NULL && cc < SERVICE_MAX);
                }
                service_order[cc] = SERVICE_NONE;
                fclose(fd);
        }
        service_done = 1;
}

struct hostent *
gethostbyname(const char *name)
{
        struct hostent *hp;

        if (_res.options & RES_USE_INET6) {             /* XXX */
                hp = gethostbyname2(name, AF_INET6);    /* XXX */
                if (hp)                                 /* XXX */
                        return (hp);                    /* XXX */
        }                                               /* XXX */
        return (gethostbyname2(name, AF_INET));
}

struct hostent *
gethostbyname2(const char *name, int type)
{
        struct hostent *hp = 0;
        int nserv = 0;

        if (!service_done)
                init_services();

        while (!hp) {
                switch (service_order[nserv]) {
                      case SERVICE_NONE:
                        return NULL;
                      case SERVICE_HOSTS:
                        hp = _gethostbyhtname(name, type);
                        break;
                      case SERVICE_BIND:
                        hp = _gethostbydnsname(name, type);
                        break;
                      case SERVICE_NIS:
                        hp = _gethostbynisname(name, type);
                        break;
                }
                nserv++;
        }
        return hp;
}

struct hostent *
gethostbyaddr(const char *addr, int len, int type)
{
        struct hostent *hp = 0;
        int nserv = 0;

        if (!service_done)
                init_services();

        while (!hp) {
                switch (service_order[nserv]) {
                      case SERVICE_NONE:
                        return 0;
                      case SERVICE_HOSTS:
                        hp = _gethostbyhtaddr(addr, len, type);
                        break;
                      case SERVICE_BIND:
                        hp = _gethostbydnsaddr(addr, len, type);
                        break;
                      case SERVICE_NIS:
                        hp = _gethostbynisaddr(addr, len, type);
                        break;
                }
                nserv++;
        }
        return hp;
}

#ifdef _THREAD_SAFE
struct hostent_data;

/*
 * Temporary function (not thread safe)
 */
int gethostbyaddr_r(const char *addr, int len, int type,
        struct hostent *result, struct hostent_data *buffer)
{
        struct hostent *hp;
        int ret;
        if ((hp = gethostbyaddr(addr, len, type)) == NULL) {
                ret = -1;
        } else {
                memcpy(result, hp, sizeof(struct hostent));
                ret = 0;
        }
        return(ret);
}
#endif

void
sethostent(stayopen)
        int stayopen;
{
        _sethosthtent(stayopen);
        _sethostdnsent(stayopen);
}

void
endhostent()
{
        _endhosthtent();
        _endhostdnsent();
}