/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * 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.
 */

#include <sys/param.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <resolv.h>
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <errno.h>
#include <string.h>
#include <stdarg.h>
#include <nsswitch.h>
#include <arpa/nameser.h>
#ifdef YP
#include <rpc/rpc.h>
#include <rpcsvc/yp_prot.h>
#include <rpcsvc/ypclnt.h>
#endif
#include "netdb_private.h"

#ifdef YP
static int
_getnetbynis(const char *name, char *map, int af, struct netent *ne,
    struct netent_data *ned)
{
        char *p, *bp, *ep;
        char *cp, **q;
        char *result;
        int resultlen, len;
        char *ypbuf;

        switch(af) {
        case AF_INET:
                break;
        default:
        case AF_INET6:
                errno = EAFNOSUPPORT;
                return (-1);
        }

        if (ned->yp_domain == (char *)NULL)
                if (yp_get_default_domain (&ned->yp_domain))
                        return (-1);

        if (yp_match(ned->yp_domain, map, name, strlen(name), &result,
            &resultlen))
                return (-1);

        ypbuf = alloca(resultlen + 2);
        bcopy(result, ypbuf, resultlen);
        ypbuf[resultlen] = '\0';
        free(result);
        result = ypbuf;

        if ((cp = strchr(result, '\n')))
                *cp = '\0';

        cp = strpbrk(result, " \t");
        *cp++ = '\0';
        bp = ned->netbuf;
        ep = ned->netbuf + sizeof ned->netbuf;
        len = strlen(result) + 1;
        if (ep - bp < len) {
                RES_SET_H_ERRNO(__res_state(), NO_RECOVERY);
                return (-1);
        }
        strlcpy(bp, result, ep - bp);
        ne->n_name = bp;
        bp += len;

        while (*cp == ' ' || *cp == '\t')
                cp++;

        ne->n_net = inet_network(cp);
        ne->n_addrtype = AF_INET;

        q = ne->n_aliases = ned->net_aliases;
        cp = strpbrk(cp, " \t");
        if (cp != NULL)
                *cp++ = '\0';
        while (cp && *cp) {
                if (*cp == ' ' || *cp == '\t') {
                        cp++;
                        continue;
                }
                if (q > &ned->net_aliases[_MAXALIASES - 1])
                        break;
                p = strpbrk(cp, " \t");
                if (p != NULL)
                        *p++ = '\0';
                len = strlen(cp) + 1;
                if (ep - bp < len)
                        break;
                strlcpy(bp, cp, ep - bp);
                *q++ = bp;
                bp += len;
                cp = p;
        }
        *q = NULL;
        return (0);
}
#endif /* YP */

int
_nis_getnetbyname(void *rval, void *cb_data, va_list ap)
{
#ifdef YP
        const char *name;
        char *buffer;
        size_t buflen;
        int *errnop, *h_errnop;
        struct netent *nptr, ne;
        struct netent_data *ned;
        res_state statp;

        name = va_arg(ap, const char *);
        nptr = va_arg(ap, struct netent *);
        buffer = va_arg(ap, char *);
        buflen = va_arg(ap, size_t);
        errnop = va_arg(ap, int *);
        h_errnop = va_arg(ap, int *);

        statp = __res_state();
        if ((ned = __netent_data_init()) == NULL) {
                RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
                *h_errnop = statp->res_h_errno;
                return (NS_UNAVAIL);
        }

        if (_getnetbynis(name, "networks.byname", AF_INET, &ne, ned) != 0) {
                *h_errnop = statp->res_h_errno;
                return (NS_NOTFOUND);
        }
        if (__copy_netent(&ne, nptr, buffer, buflen) != 0) {
                *errnop = errno;
                RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
                *h_errnop = statp->res_h_errno;
                return (NS_RETURN);
        }
        *((struct netent **)rval) = nptr;
        return (NS_SUCCESS);
#else
        return (NS_UNAVAIL);
#endif

}

int
_nis_getnetbyaddr(void *rval, void *cb_data, va_list ap)
{
#ifdef YP
        uint32_t addr;
        int af;
        char *buffer;
        size_t buflen;
        int *errnop, *h_errnop;
        struct netent *nptr, ne;
        struct netent_data *ned;
        char *str, *cp;
        uint32_t net2;
        int nn;
        unsigned int netbr[4];
        char buf[MAXDNAME];
        res_state statp;

        addr = va_arg(ap, uint32_t);
        af = va_arg(ap, int);
        nptr = va_arg(ap, struct netent *);
        buffer = va_arg(ap, char *);
        buflen = va_arg(ap, size_t);
        errnop = va_arg(ap, int *);
        h_errnop = va_arg(ap, int *);

        statp = __res_state();
        if ((ned = __netent_data_init()) == NULL) {
                RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
                *h_errnop = statp->res_h_errno;
                return (NS_UNAVAIL);
        }

        if (af != AF_INET) {
                RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
                *h_errnop = statp->res_h_errno;
                errno = EAFNOSUPPORT;
                return (NS_UNAVAIL);
        }

        for (nn = 4, net2 = addr; net2; net2 >>= 8) {
                netbr[--nn] = net2 & 0xff;
        }

        switch (nn) {
        case 3:         /* Class A */
                sprintf(buf, "%u", netbr[3]);
                break;
        case 2:         /* Class B */
                sprintf(buf, "%u.%u", netbr[2], netbr[3]);
                break;
        case 1:         /* Class C */
                sprintf(buf, "%u.%u.%u", netbr[1], netbr[2], netbr[3]);
                break;
        case 0:         /* Class D - E */
                sprintf(buf, "%u.%u.%u.%u", netbr[0], netbr[1],
                        netbr[2], netbr[3]);
                break;
        }

        str = (char *)&buf;
        cp = str + (strlen(str) - 2);

        while(!strcmp(cp, ".0")) {
                *cp = '\0';
                cp = str + (strlen(str) - 2);
        }

        if (_getnetbynis(str, "networks.byaddr", af, &ne, ned) != 0) {
                *h_errnop = statp->res_h_errno;
                return (NS_NOTFOUND);
        }
        if (__copy_netent(&ne, nptr, buffer, buflen) != 0) {
                *errnop = errno;
                RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
                *h_errnop = statp->res_h_errno;
                return (NS_RETURN);
        }
        *((struct netent **)rval) = nptr;
        return (NS_SUCCESS);
#else
        return (NS_UNAVAIL);
#endif /* YP */
}