nfs/lib/sharetab.c

	sharetab.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (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 1999 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*  Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */
/*    All Rights Reserved   */

/*
 * Portions of this source code were derived from Berkeley 4.3 BSD
 * under license from the Regents of the University of California.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "sharetab.h"

static int logging_specified(char *);

/*
 * Get an entry from the share table.
 * There should be at least 4 fields:
 *
 *  pathname  resource  fstype  options  [ description ]
 *
 * A fifth field (description) is optional.
 *
 * Returns:
 *  > 1  valid entry
 *  = 0  end of file
 *  < 0  error
 */
int
getshare(fd, shp)
    FILE *fd;
    struct share **shp;
{
    static char *line = NULL;
    static struct share *sh = NULL;
    char *p;
    char *lasts;
    char *w = " \t";

    if (line == NULL) {
        line = (char *)malloc(MAXBUFSIZE+1);
        if (line == NULL)
            return (-1);
    }
    if (sh == NULL) {
        sh = (struct share *)malloc(sizeof (*sh));
        if (sh == NULL)
            return (-1);
    }

    p = fgets(line, MAXBUFSIZE, fd);
    if (p == NULL)
        return (0);
    line[strlen(line) - 1] = '\0';

    sh->sh_path = (char *)strtok_r(p, w, &lasts);
    if (sh->sh_path == NULL)
        return (-3);
    sh->sh_res = (char *)strtok_r(NULL, w, &lasts);
    if (sh->sh_res == NULL)
        return (-3);
    sh->sh_fstype = (char *)strtok_r(NULL, w, &lasts);
    if (sh->sh_fstype == NULL)
        return (-3);
    sh->sh_opts = (char *)strtok_r(NULL, w, &lasts);
    if (sh->sh_opts == NULL)
        return (-3);
    sh->sh_descr = (char *)strtok_r(NULL, "", &lasts);
    if (sh->sh_descr == NULL)
        sh->sh_descr = "";

    *shp = sh;
    return (1);
}

/*
 * Append an entry to the sharetab file.
 */
int
putshare(fd, sh)
    FILE *fd;
    struct share *sh;
{
    int r;

    if (fseek(fd, 0L, 2) < 0)
        return (-1);

    r = fprintf(fd, "%s\t%s\t%s\t%s\t%s\n",
        sh->sh_path,
        sh->sh_res,
        sh->sh_fstype,
        sh->sh_opts,
        sh->sh_descr);
    return (r);
}

/*
 * The entry corresponding to path is removed from the
 * sharetab file.  The file is assumed to be locked.
 * Read the entries into a linked list of share structures
 * minus the entry to be removed.  Then truncate the sharetab
 * file and write almost all of it back to the file from the
 * linked list.
 *
 * If logging information is requested then 'logging' is set
 * to non-zero if the entry is shared with logging enabled.
 *
 * Note: The file is assumed to be locked.
 */
int
remshare(fd, path, logging)
    FILE *fd;
    char *path;
    int *logging;
{
    struct share *sh_tmp;
    struct shl {            /* the linked list */
        struct shl   *shl_next;
        struct share *shl_sh;
    };
    struct shl *shl_head = NULL;
    struct shl *shl, *prev, *next;
    int res, remcnt;

    rewind(fd);
    remcnt = 0;
    shl = NULL;
    while ((res = getshare(fd, &sh_tmp)) > 0) {
        if (strcmp(path, sh_tmp->sh_path) == 0 ||
            strcmp(path, sh_tmp->sh_res)  == 0) {
            remcnt++;
            if (logging != NULL)
                *logging = logging_specified(sh_tmp->sh_opts);
        } else {
            prev = shl;
            shl = (struct shl *)malloc(sizeof (*shl));
            if (shl == NULL) {
                res = -1;
                goto dealloc;
            }
            if (shl_head == NULL)
                shl_head = shl;
            else
                prev->shl_next = shl;
            shl->shl_next = NULL;
            shl->shl_sh = sharedup(sh_tmp);
            if (shl->shl_sh == NULL) {
                res = -3;
                goto dealloc;
            }
        }
    }
    if (res < 0)
        goto dealloc;
    if (remcnt == 0) {
        res = 1;    /* nothing removed */
        goto dealloc;
    }

    if (ftruncate(fileno(fd), 0) < 0) {
        res = -2;
        goto dealloc;
    }

    for (shl = shl_head; shl; shl = shl->shl_next)
        putshare(fd, shl->shl_sh);
    res = 1;

dealloc:
    for (shl = shl_head; shl; shl = next) {
        /*
         * make sure we don't reference sharefree with NULL shl->shl_sh
         */
        if (shl->shl_sh != NULL)
            sharefree(shl->shl_sh);
        next = shl->shl_next;
        free(shl);
    }
    return (res);
}

struct share *
sharedup(sh)
    struct share *sh;
{
    struct share *nsh;

    nsh = (struct share *)malloc(sizeof (*nsh));
    if (nsh == NULL)
        return (NULL);

    (void) memset((char *)nsh, 0, sizeof (*nsh));
    if (sh->sh_path) {
        nsh->sh_path = strdup(sh->sh_path);
        if (nsh->sh_path == NULL)
            goto alloc_failed;
    }

    if (sh->sh_res) {
        nsh->sh_res = strdup(sh->sh_res);
        if (nsh->sh_res == NULL)
            goto alloc_failed;
    }
    if (sh->sh_fstype) {
        nsh->sh_fstype = strdup(sh->sh_fstype);
        if (nsh->sh_fstype == NULL)
            goto alloc_failed;
    }
    if (sh->sh_opts) {
        nsh->sh_opts = strdup(sh->sh_opts);
        if (nsh->sh_opts == NULL)
            goto alloc_failed;
    }
    if (sh->sh_descr) {
        nsh->sh_descr = strdup(sh->sh_descr);
        if (nsh->sh_descr == NULL)
            goto alloc_failed;
    }
    return (nsh);

alloc_failed:
    sharefree(nsh);
    return (NULL);
}

void
sharefree(sh)
    struct share *sh;
{
    if (sh->sh_path != NULL)
        free(sh->sh_path);
    if (sh->sh_res != NULL)
        free(sh->sh_res);
    if (sh->sh_fstype != NULL)
        free(sh->sh_fstype);
    if (sh->sh_opts != NULL)
        free(sh->sh_opts);
    if (sh->sh_descr != NULL)
        free(sh->sh_descr);
    free(sh);
}

/*
 * Return the value after "=" for option "opt"
 * in option string "optlist". Caller must
 * free returned value.
 */
char *
getshareopt(optlist, opt)
    char *optlist, *opt;
{
    char *p, *pe;
    char *b;
    char *bb;
    char *lasts;
    char *val = NULL;

    b = bb = strdup(optlist);
    if (b == NULL)
        return (NULL);

    while (p = (char *)strtok_r(b, ",", &lasts)) {
        b = NULL;
        if (pe = strchr(p, '=')) {
            *pe = '\0';
            if (strcmp(opt, p) == 0) {
                val = strdup(pe + 1);
                goto done;
            }
        }
        if (strcmp(opt, p) == 0) {
            val = strdup("");
            goto done;
        }
    }
done:
    free(bb);
    return (val);
}

/*
 * Return 1 if the "log" option was specified in the optlist.
 * Return 0 otherwise.
 */
static int
logging_specified(optlist)
    char *optlist;
{
    char *p;
    char *b, *bb, *lasts;
    int specified = 0;

    b = bb = strdup(optlist);
    if (b == NULL)
        return (0);

    while (p = (char *)strtok_r(b, ",", &lasts)) {
        b = NULL;
        if (strncmp(p, "log", 3) == 0)
            specified++;
    }

    free(bb);
    return (specified ? 1 : 0);
}