port/gen/getvfsent.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) 1989, 2010, Oracle and/or its affiliates. All rights reserved.
 */

/*  Copyright (c) 1988 AT&T */
/*    All Rights Reserved   */

#include    "lint.h"
#include    <mtlib.h>
#include    <stdio.h>
#include    <stdlib.h>
#include    <errno.h>
#include    <sys/types.h>
#include    <sys/stat.h>
#include    <sys/vfstab.h>
#include    <string.h>
#include    <thread.h>
#include    <synch.h>
#include    <strings.h>
#include    <libc.h>
#include    "tsd.h"


#define GETTOK_R(xx, ll, tmp)\
    if ((vp->xx = (char *)strtok_r(ll, sepstr, tmp)) == NULL)\
        return (VFS_TOOFEW);\
    if (strcmp(vp->xx, dash) == 0)\
        vp->xx = NULL
#define GETTOK(xx, ll)\
    if ((vp->xx = strtok(ll, sepstr)) == NULL)\
        return (VFS_TOOFEW);\
    if (strcmp(vp->xx, dash) == 0)\
        vp->xx = NULL
#define DIFF(xx)\
    (vrefp->xx != NULL && (vgetp->xx == NULL ||\
        strcmp(vrefp->xx, vgetp->xx) != 0))
#define SDIFF(xx, typem, typer)\
    (vgetp->xx == NULL || stat64(vgetp->xx, &statb) == -1 ||\
    (statb.st_mode & S_IFMT) != typem ||\
        statb.st_rdev != typer)

static const char   sepstr[] = " \t\n";
static const char   dash[] = "-";

static int  getaline(char *, FILE *);

int
getvfsspec(FILE *fd, struct vfstab *vgetp, char *special)
{
    int ret, bstat;
    mode_t  bmode;
    dev_t   brdev;
    struct stat64   statb;


    if (special && stat64(special, &statb) == 0 &&
        ((bmode = (statb.st_mode & S_IFMT)) == S_IFBLK ||
        bmode == S_IFCHR)) {
        bstat = 1;
        brdev = statb.st_rdev;
    } else
        bstat = 0;

    while ((ret = getvfsent(fd, vgetp)) == 0 &&
        ((bstat == 0 &&
        (special != NULL && (vgetp->vfs_special == NULL ||
        strcmp(special, vgetp->vfs_special) != 0))) ||
        (bstat == 1 &&
        (vgetp->vfs_special == NULL ||
        stat64(vgetp->vfs_special, &statb) == -1 ||
        (statb.st_mode & S_IFMT) != bmode ||
        statb.st_rdev != brdev))))
        ;
    return (ret);
}

int
getvfsfile(FILE *fd, struct vfstab *vp, char *mountp)
{
    struct vfstab   vv;

    bzero(&vv, (size_t)sizeof (vv));
    vv.vfs_mountp = mountp;
    return (getvfsany(fd, vp, &vv));
}

int
getvfsany(FILE *fd, struct vfstab *vgetp, struct vfstab *vrefp)
{
    int ret, bstat, cstat;
    mode_t  bmode, cmode;
    dev_t   brdev, crdev;
    struct stat64   statb;
    off64_t start = ftello64(fd);

    /* Match by straight strcmp */
    while ((ret = getvfsent(fd, vgetp)) == 0 &&
        (DIFF(vfs_special) || DIFF(vfs_fsckdev) ||
        DIFF(vfs_mountp) ||
        DIFF(vfs_fstype) ||
        DIFF(vfs_fsckpass) ||
        DIFF(vfs_automnt) ||
        DIFF(vfs_mntopts)))
        ;

    /* If something other than EOF, return it */
    if (ret != -1)
        return (ret);

    /*
     * Go back to the original location in the file and try to
     * match the devices by doing stat's (retains compatibility
     * with original getvfsany).
     */
    (void) fseeko64(fd, start, SEEK_SET);

    if (vrefp->vfs_special && stat64(vrefp->vfs_special, &statb) == 0 &&
        ((bmode = (statb.st_mode & S_IFMT)) == S_IFBLK ||
        bmode == S_IFCHR)) {
        bstat = 1;
        brdev = statb.st_rdev;
    } else
        bstat = 0;

    if (vrefp->vfs_fsckdev && stat64(vrefp->vfs_fsckdev, &statb) == 0 &&
        ((cmode = (statb.st_mode & S_IFMT)) == S_IFBLK ||
        cmode == S_IFCHR)) {
        cstat = 1;
        crdev = statb.st_rdev;
    } else
        cstat = 0;

    while ((ret = getvfsent(fd, vgetp)) == 0 &&
        ((bstat == 0 && DIFF(vfs_special)) ||
        (bstat == 1 && SDIFF(vfs_special, bmode, brdev)) ||
        (cstat == 0 && DIFF(vfs_fsckdev)) ||
        (cstat == 1 && SDIFF(vfs_fsckdev, cmode, crdev)) ||
        DIFF(vfs_mountp) ||
        DIFF(vfs_fstype) ||
        DIFF(vfs_fsckpass) ||
        DIFF(vfs_automnt) ||
        DIFF(vfs_mntopts)))
        ;
    return (ret);
}

int
getvfsent(FILE *fd, struct vfstab *vp)
{
    int ret;
    char    *tmp, *line;

    line = tsdalloc(_T_GETVFSENT, VFS_LINE_MAX, NULL);
    if (line == NULL)
        return (0);

    /* skip leading spaces and comments */
    if ((ret = getaline(line, fd)) != 0)
        return (ret);

    /* split up each field */
    GETTOK_R(vfs_special, line, &tmp);
    GETTOK_R(vfs_fsckdev, NULL, &tmp);
    GETTOK_R(vfs_mountp, NULL, &tmp);
    GETTOK_R(vfs_fstype, NULL, &tmp);
    GETTOK_R(vfs_fsckpass, NULL, &tmp);
    GETTOK_R(vfs_automnt, NULL, &tmp);
    GETTOK_R(vfs_mntopts, NULL, &tmp);

    /* check for too many fields */
    if (strtok_r(NULL, sepstr, &tmp) != NULL)
        return (VFS_TOOMANY);

    return (0);
}

static int
getaline(char *lp, FILE *fd)
{
    char    *cp;

    while ((lp = fgets(lp, VFS_LINE_MAX, fd)) != NULL) {
        if (strlen(lp) == VFS_LINE_MAX-1 && lp[VFS_LINE_MAX-2] != '\n')
            return (VFS_TOOLONG);

        for (cp = lp; *cp == ' ' || *cp == '\t'; cp++)
            ;

        if (*cp != '#' && *cp != '\n')
            return (0);
    }
    return (-1);
}