files/common/bootparams_getbyname.c

/*
 * 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
 */
/*
 * Copyright (c) 1992, 2011, Oracle and/or its affiliates. All rights reserved.
 *
 *  files/bootparams_getbyname.c -- "files" backend for
 *  nsswitch "bootparams" database.
 */

static const char *bootparams = "/etc/bootparams";

#include "files_common.h"
#include <stdlib.h>
#include <ctype.h>
#include <strings.h>

static nss_status_t _nss_files_XY_bootparams(files_backend_ptr_t,
    nss_XbyY_args_t *, const char *);

static nss_status_t
getbyname(be, a)
    files_backend_ptr_t be;
    void            *a;
{
    nss_XbyY_args_t     *argp = (nss_XbyY_args_t *)a;
    nss_status_t        res;

    /* bootparams_getbyname() has not set/endent; rewind on each call */
    if ((res = _nss_files_setent(be, 0)) != NSS_SUCCESS) {
        return (res);
    }
    return (_nss_files_XY_bootparams(be, argp, argp->key.name));
}

static files_backend_op_t bootparams_ops[] = {
    _nss_files_destr,
    getbyname
};

/*ARGSUSED*/
nss_backend_t *
_nss_files_bootparams_constr(dummy1, dummy2, dummy3)
    const char  *dummy1, *dummy2, *dummy3;
{
    return (_nss_files_constr(bootparams_ops,
        sizeof (bootparams_ops) / sizeof (bootparams_ops[0]),
        bootparams,
        NSS_LINELEN_BOOTPARAMS,
        NULL, 0));
}

/*
 * bootparams has the hostname as part of the data in the file, but the other
 * backends don't include it in the data passed to the backend.  For this
 * reason, we process everything here and don't bother calling the backend.
 */
/*ARGSUSED*/
static nss_status_t
_nss_files_XY_bootparams(be, args, filter)
    files_backend_ptr_t be;
    nss_XbyY_args_t     *args;
    const char      *filter;
            /*
             * filter not useful here since the key
             * we are looking for is the first "word"
             * on the line and we can be fast enough.
             */
{
    nss_status_t        res;

    if (be->buf == 0 &&
        (be->buf = (char *)malloc(be->minbuf)) == 0) {
        (void) _nss_files_endent(be, 0);
        return (NSS_UNAVAIL); /* really panic, malloc failed */
    }

    res = NSS_NOTFOUND;

    /*CONSTCOND*/
    while (1) {
        char        *instr  = be->buf;
        char        *p, *host, *limit;
        int     linelen;

        /*
         * _nss_files_read_line does process the '\' that are used
         * in /etc/bootparams for continuation and gives one long
         * buffer.
         *
         * linelen counts the characters up to but excluding the '\n'
         */
        if ((linelen = _nss_files_read_line(be, instr,
            be->minbuf)) < 0) {
            /* End of file */
            args->returnval = 0;
            args->returnlen = 0;
            break;
        }

        /*
         * we need to strip off the host name before returning it.
         */
        p = instr;
        limit = p + linelen;

        /* Skip over leading whitespace */
        while (p < limit && isspace(*p)) {
            p++;
        }
        host = p;

        /* Skip over the hostname */
        while (p < limit && !isspace(*p)) {
            p++;
        }
        *p++ = '\0';

        if (strcasecmp(args->key.name, host) != 0) {
            continue;
        }

        /* Skip over whitespace between name and first datum */
        while (p < limit && isspace(*p)) {
            p++;
        }
        if (p >= limit) {
            /* Syntax error -- no data! Just skip it. */
            continue;
        }

        linelen -= (p - instr);
        if (args->buf.buflen <= linelen) {  /* not enough buffer */
            args->erange = 1;
            break;
        }
        (void) memcpy(args->buf.buffer, p, linelen);
        args->buf.buffer[linelen] = '\0';
        args->returnval = args->buf.result;
        args->returnlen = linelen;
        res = NSS_SUCCESS;
        break;
    }
    (void) _nss_files_endent(be, 0);
    return (res);
}