common/irs/lcl_nw.c

/*
 * 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.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static const char rcsid[] = "$Id: lcl_nw.c,v 1.4 2005/04/27 04:56:31 sra Exp $";
/* 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 $  */
#endif /* LIBC_SCCS and not lint */

/* 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 */