/*
 * Copyright (c) 1989, 1993, 1995
 *      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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. 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.
 */

/*
 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
 * Portions Copyright (c) 1996-1999 by 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 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.
 */

/* from getgrent.c 8.2 (Berkeley) 3/21/94"; */
/* from BSDI Id: getgrent.c,v 2.8 1996/05/28 18:15:14 bostic Exp $      */

/* Imports */

#include "port_before.h"

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

#include <netinet/in.h>
#include <arpa/inet.h>
#include <arpa/nameser.h>

#include <errno.h>
#include <fcntl.h>
#include <resolv.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <irs.h>
#include <isc/memcluster.h>

#include "port_after.h"

#include <isc/misc.h>
#include "irs_p.h"
#include "lcl_p.h"

#define MAXALIASES 35
#define MAXADDRSIZE 4

struct pvt {
        FILE *          fp;
        char            line[BUFSIZ+1];
        struct nwent    net;
        char *          aliases[MAXALIASES];
        char            addr[MAXADDRSIZE];
        struct __res_state *  res;
        void            (*free_res)(void *);
};

/* Forward */

static void             nw_close(struct irs_nw *);
static struct nwent *   nw_byname(struct irs_nw *, const char *, int);
static struct nwent *   nw_byaddr(struct irs_nw *, void *, int, int);
static struct nwent *   nw_next(struct irs_nw *);
static void             nw_rewind(struct irs_nw *);
static void             nw_minimize(struct irs_nw *);
static struct __res_state * nw_res_get(struct irs_nw *this);
static void             nw_res_set(struct irs_nw *this,
                                   struct __res_state *res,
                                   void (*free_res)(void *));

static int              init(struct irs_nw *this);

/* Portability. */

#ifndef SEEK_SET
# define SEEK_SET 0
#endif

/* Public */

struct irs_nw *
irs_lcl_nw(struct irs_acc *this) {
        struct irs_nw *nw;
        struct pvt *pvt;

        UNUSED(this);

        if (!(pvt = memget(sizeof *pvt))) {
                errno = ENOMEM;
                return (NULL);
        }
        memset(pvt, 0, sizeof *pvt);
        if (!(nw = memget(sizeof *nw))) {
                memput(pvt, sizeof *pvt);
                errno = ENOMEM;
                return (NULL);
        }
        memset(nw, 0x5e, sizeof *nw);
        nw->private = pvt;
        nw->close = nw_close;
        nw->byname = nw_byname;
        nw->byaddr = nw_byaddr;
        nw->next = nw_next;
        nw->rewind = nw_rewind;
        nw->minimize = nw_minimize;
        nw->res_get = nw_res_get;
        nw->res_set = nw_res_set;
        return (nw);
}

/* Methods */

static void
nw_close(struct irs_nw *this) {
        struct pvt *pvt = (struct pvt *)this->private;

        nw_minimize(this);
        if (pvt->res && pvt->free_res)
                (*pvt->free_res)(pvt->res);
        if (pvt->fp)
                (void)fclose(pvt->fp);
        memput(pvt, sizeof *pvt);
        memput(this, sizeof *this);
}

static struct nwent *
nw_byaddr(struct irs_nw *this, void *net, int length, int type) {
        struct nwent *p;

        if (init(this) == -1)
                return(NULL);

        nw_rewind(this);
        while ((p = nw_next(this)) != NULL)
                if (p->n_addrtype == type && p->n_length == length)
                        if (bitncmp(p->n_addr, net, length) == 0)
                                break;
        return (p);
}

static struct nwent *
nw_byname(struct irs_nw *this, const char *name, int type) {
        struct nwent *p;
        char **ap;

        if (init(this) == -1)
                return(NULL);

        nw_rewind(this);
        while ((p = nw_next(this)) != NULL) {
                if (ns_samename(p->n_name, name) == 1 &&
                    p->n_addrtype == type)
                        break;
                for (ap = p->n_aliases; *ap; ap++)
                        if ((ns_samename(*ap, name) == 1) &&
                            (p->n_addrtype == type))
                                goto found;
        }
 found:
        return (p);
}

static void
nw_rewind(struct irs_nw *this) {
        struct pvt *pvt = (struct pvt *)this->private;

        if (pvt->fp) {
                if (fseek(pvt->fp, 0L, SEEK_SET) == 0)
                        return;
                (void)fclose(pvt->fp);
        }
        if (!(pvt->fp = fopen(_PATH_NETWORKS, "r")))
                return;
        if (fcntl(fileno(pvt->fp), F_SETFD, 1) < 0) {
                (void)fclose(pvt->fp);
                pvt->fp = NULL;
        }
}

static struct nwent *
nw_next(struct irs_nw *this) {
        struct pvt *pvt = (struct pvt *)this->private;
        struct nwent *ret = NULL;
        char *p, *cp, **q;
        char *bufp, *ndbuf, *dbuf = NULL;
        int c, bufsiz, offset = 0;

        if (init(this) == -1)
                return(NULL);

        if (pvt->fp == NULL)
                nw_rewind(this);
        if (pvt->fp == NULL) {
                RES_SET_H_ERRNO(pvt->res, NETDB_INTERNAL);
                return (NULL);
        }
        bufp = pvt->line;
        bufsiz = sizeof(pvt->line);

 again:
        p = fgets(bufp + offset, bufsiz - offset, pvt->fp);
        if (p == NULL)
                goto cleanup;
        if (!strchr(p, '\n') && !feof(pvt->fp)) {
#define GROWBUF 1024
                /* allocate space for longer line */
                if (dbuf == NULL) {
                        if ((ndbuf = malloc(bufsiz + GROWBUF)) != NULL)
                                strcpy(ndbuf, bufp);
                } else
                        ndbuf = realloc(dbuf, bufsiz + GROWBUF);
                if (ndbuf) {
                        dbuf = ndbuf;
                        bufp = dbuf;
                        bufsiz += GROWBUF;
                        offset = strlen(dbuf);
                } else {
                        /* allocation failed; skip this long line */
                        while ((c = getc(pvt->fp)) != EOF)
                                if (c == '\n')
                                        break;
                        if (c != EOF)
                                ungetc(c, pvt->fp);
                }
                goto again;
        }

        p -= offset;
        offset = 0;

        if (*p == '#')
                goto again;

        cp = strpbrk(p, "#\n");
        if (cp != NULL)
                *cp = '\0';
        pvt->net.n_name = p;
        cp = strpbrk(p, " \t");
        if (cp == NULL)
                goto again;
        *cp++ = '\0';
        while (*cp == ' ' || *cp == '\t')
                cp++;
        p = strpbrk(cp, " \t");
        if (p != NULL)
                *p++ = '\0';
        pvt->net.n_length = inet_net_pton(AF_INET, cp, pvt->addr,
                                          sizeof pvt->addr);
        if (pvt->net.n_length < 0)
                goto again;
        pvt->net.n_addrtype = AF_INET;
        pvt->net.n_addr = pvt->addr;
        q = pvt->net.n_aliases = pvt->aliases;
        if (p != NULL) {
                cp = p;
                while (cp && *cp) {
                        if (*cp == ' ' || *cp == '\t') {
                                cp++;
                                continue;
                        }
                        if (q < &pvt->aliases[MAXALIASES - 1])
                                *q++ = cp;
                        cp = strpbrk(cp, " \t");
                        if (cp != NULL)
                                *cp++ = '\0';
                }
        }
        *q = NULL;
        ret = &pvt->net;

 cleanup:
        if (dbuf)
                free(dbuf);

        return (ret);
}

static void
nw_minimize(struct irs_nw *this) {
        struct pvt *pvt = (struct pvt *)this->private;

        if (pvt->res)
                res_nclose(pvt->res);
        if (pvt->fp != NULL) {
                (void)fclose(pvt->fp);
                pvt->fp = NULL;
        }
}

static struct __res_state *
nw_res_get(struct irs_nw *this) {
        struct pvt *pvt = (struct pvt *)this->private;

        if (!pvt->res) {
                struct __res_state *res;
                res = (struct __res_state *)malloc(sizeof *res);
                if (!res) {
                        errno = ENOMEM;
                        return (NULL);
                }
                memset(res, 0, sizeof *res);
                nw_res_set(this, res, free);
        }

        return (pvt->res);
}

static void
nw_res_set(struct irs_nw *this, struct __res_state *res,
                void (*free_res)(void *)) {
        struct pvt *pvt = (struct pvt *)this->private;

        if (pvt->res && pvt->free_res) {
                res_nclose(pvt->res);
                (*pvt->free_res)(pvt->res);
        }

        pvt->res = res;
        pvt->free_res = free_res;
}

static int
init(struct irs_nw *this) {
        struct pvt *pvt = (struct pvt *)this->private;

        if (!pvt->res && !nw_res_get(this))
                return (-1);
        if (((pvt->res->options & RES_INIT) == 0U) &&
            res_ninit(pvt->res) == -1)
                return (-1);
        return (0);
}

/*! \file */