/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1983, 1993
 *      The Regents of the University of California.  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 University 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 REGENTS 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 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.
 */

/* Portions Copyright (c) 1993 Carlos Leandro and Rui Salgueiro
 *      Dep. Matematica Universidade de Coimbra, Portugal, Europe
 *
 * 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.
 *
 * from getnetent.c     1.1 (Coimbra) 93/06/02
 */

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <arpa/nameser.h>
#include <errno.h>
#include <netdb.h>
#include <resolv.h>
#include <stdio.h>
#include <string.h>
#include <stdarg.h>
#include <nsswitch.h>
#include "netdb_private.h"

void
_setnethtent(int f, struct netent_data *ned)
{

        if (ned->netf == NULL)
                ned->netf = fopen(_PATH_NETWORKS, "re");
        else
                rewind(ned->netf);
        ned->stayopen |= f;
}

void
_endnethtent(struct netent_data *ned)
{

        if (ned->netf) {
                fclose(ned->netf);
                ned->netf = NULL;
        }
        ned->stayopen = 0;
}

static int
getnetent_p(struct netent *ne, struct netent_data *ned)
{
        char *p, *bp, *ep;
        char *cp, **q;
        int len;
        char line[BUFSIZ + 1];

        if (ned->netf == NULL &&
            (ned->netf = fopen(_PATH_NETWORKS, "re")) == NULL)
                return (-1);
again:
        p = fgets(line, sizeof line, ned->netf);
        if (p == NULL)
                return (-1);
        if (*p == '#')
                goto again;
        cp = strpbrk(p, "#\n");
        if (cp != NULL)
                *cp = '\0';
        bp = ned->netbuf;
        ep = ned->netbuf + sizeof ned->netbuf;
        ne->n_name = bp;
        cp = strpbrk(p, " \t");
        if (cp == NULL)
                goto again;
        *cp++ = '\0';
        len = strlen(p) + 1;
        if (ep - bp < len) {
                RES_SET_H_ERRNO(__res_state(), NO_RECOVERY);
                return (-1);
        }
        strlcpy(bp, p, ep - bp);
        bp += len;
        while (*cp == ' ' || *cp == '\t')
                cp++;
        p = strpbrk(cp, " \t");
        if (p != NULL)
                *p++ = '\0';
        ne->n_net = inet_network(cp);
        ne->n_addrtype = AF_INET;
        q = ne->n_aliases = ned->net_aliases;
        if (p != NULL) {
                cp = p;
                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);
}

int
getnetent_r(struct netent *nptr, char *buffer, size_t buflen,
    struct netent **result, int *h_errnop)
{
        struct netent_data *ned;
        struct netent ne;
        res_state statp;

        statp = __res_state();
        if ((ned = __netent_data_init()) == NULL) {
                RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
                *h_errnop = statp->res_h_errno;
                return (-1);
        }
        if (getnetent_p(&ne, ned) != 0)
                return (-1);
        if (__copy_netent(&ne, nptr, buffer, buflen) != 0) {
                RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
                *h_errnop = statp->res_h_errno;
                return ((errno != 0) ? errno : -1);
        }
        *result = nptr;
        return (0);
}

struct netent *
getnetent(void)
{
        struct netdata *nd;
        struct netent *rval;
        int ret_h_errno;

        if ((nd = __netdata_init()) == NULL)
                return (NULL);
        if (getnetent_r(&nd->net, nd->data, sizeof(nd->data), &rval,
            &ret_h_errno) != 0)
                return (NULL);
        return (rval);
}

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

        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);
        }

        _setnethtent(ned->stayopen, ned);
        while ((error = getnetent_p(&ne, ned)) == 0) {
                if (strcasecmp(ne.n_name, name) == 0)
                        break;
                for (cp = ne.n_aliases; *cp != 0; cp++)
                        if (strcasecmp(*cp, name) == 0)
                                goto found;
        }
found:
        if (!ned->stayopen)
                _endnethtent(ned);
        if (error != 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);
}

int
_ht_getnetbyaddr(void *rval, void *cb_data, va_list ap)
{
        uint32_t net;
        int type;
        char *buffer;
        size_t buflen;
        int *errnop, *h_errnop;
        struct netent *nptr, ne;
        struct netent_data *ned;
        res_state statp;
        int error;

        net = va_arg(ap, uint32_t);
        type = 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);
        }

        _setnethtent(ned->stayopen, ned);
        while ((error = getnetent_p(&ne, ned)) == 0)
                if (ne.n_addrtype == type && ne.n_net == net)
                        break;
        if (!ned->stayopen)
                _endnethtent(ned);
        if (error != 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);
}