/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * files/ether_addr.c -- "files" backend for nsswitch "ethers" database
 *
 * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * All routines necessary to deal with the file /etc/ethers.  The file
 * contains mappings from 48 bit ethernet addresses to their corresponding
 * hosts names.  The addresses have an ascii representation of the form
 * "x:x:x:x:x:x" where x is a hex number between 0x00 and 0xff;  the
 * bytes are always in network order.
 */

#include <sys/types.h>
#include <sys/socket.h>
#include <net/if.h>
#include <netinet/in.h>
#include <netinet/if_ether.h>
#include <nss_dbdefs.h>
#include "files_common.h"
#include <strings.h>
#include <ctype.h>

#define _PATH_ETHERS    "/etc/ethers"
#define DIGIT(x)        \
        (isdigit(x) ? (x) - '0' : islower(x) ? (x) + 10 - 'a' : (x) + 10 - 'A')

static int
check_host(nss_XbyY_args_t *argp, const char *line, int linelen)
{
        const char      *limit, *linep, *keyp;
        linep = line;
        limit = line + linelen;

        /* skip leading spaces */
        while (linep < limit && isspace(*linep))
                linep++;
        /* skip mac address */
        while (linep < limit && !isspace(*linep))
                linep++;
        /* skip the delimiting spaces */
        while (linep < limit && isspace(*linep))
                linep++;
        if (linep == limit)
                return (0);

        /* compare the host name */
        keyp = argp->key.name;
        while (*keyp != '\0' && linep < limit && *keyp == *linep) {
                keyp++;
                linep++;
        }
        return (*keyp == '\0' && linep == limit);
}

static nss_status_t
getbyhost(be, a)
        files_backend_ptr_t     be;
        void                    *a;
{
        nss_XbyY_args_t         *argp = (nss_XbyY_args_t *)a;
        char    hostname[MAXHOSTNAMELEN];
        nss_status_t            res;

        /*
         * use the buffer passed in if result is to be returned
         * in /etc file format
         */
        if (argp->buf.result != NULL) {
                argp->buf.buffer = hostname;
                argp->buf.buflen = MAXHOSTNAMELEN;
        }

        res = _nss_files_XY_all(be, argp, 0, argp->key.name, check_host);

        if (argp->buf.result != NULL) {
                argp->buf.buffer = NULL;
                argp->buf.buflen = 0;
        }

        return (res);
}

static int
check_ether(nss_XbyY_args_t *argp, const char *line, int linelen)
{

        const char      *limit, *linep;
        uchar_t         ether[6];
        ptrdiff_t       i;
        int             n;

        linep = line;
        limit = line + linelen;

        /* skip leading spaces */
        while (linep < limit && isspace(*linep))
                linep++;

        for (i = 0; i < 6; i++) {
                n = 0;
                while (linep < limit && isxdigit(*linep)) {
                        n = 16 * n + DIGIT(*linep);
                        linep++;
                }
                if (*linep != ':' && i < 5) {
                        return (0);
                } else if (*linep == ':' && i == 5) {
                        return (0);
                } else {
                        linep++;
                        ether[i] = (uchar_t)n;
                }
        }
        return (ether_cmp((void *)ether, (void *)argp->key.ether) == 0);
}

static nss_status_t
getbyether(be, a)
        files_backend_ptr_t     be;
        void                    *a;
{
        nss_XbyY_args_t         *argp = (nss_XbyY_args_t *)a;
        struct ether_addr       etheraddr;
        nss_status_t            res;

        argp->buf.result        = &etheraddr;

        res = _nss_files_XY_all(be, argp, 0, NULL, check_ether);

        argp->buf.result        = NULL;
        return (res);
}

static files_backend_op_t ethers_ops[] = {
        _nss_files_destr,
        getbyhost,
        getbyether
};

/*ARGSUSED*/
nss_backend_t *
_nss_files_ethers_constr(dummy1, dummy2, dummy3)
        const char      *dummy1, *dummy2, *dummy3;
{
        return (_nss_files_constr(ethers_ops,
                                sizeof (ethers_ops) / sizeof (ethers_ops[0]),
                                _PATH_ETHERS,
                                NSS_LINELEN_ETHERS,
                                NULL));
}