mntd_mount.c

/***************************************************************************
 * CVSID: $Id: mntd_mount.c,v 1.19 2005/03/29 23:32:03 stefanb Exp $
 *
 * mntd_mount.c : Mount helper for MNT daemon
 *
 * Copyright (C) 2004 Stefan Bambach, <sbambach@gmx.net>
 *
 * Licensed under the GNU General Public License 2.0
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 **************************************************************************/
 
#ifdef HAVE_CONFIG_H
#  include <config.h>
#endif

#include <mntent.h>
#include <stdlib.h>
#include <glib.h>
#include <errno.h>

#include "mntd_mount.h"
#include "errmanager.h"
#include "main.h"
#include "dbug_mem.h"


extern int errno;


int 
mntd_mount_mount(const char *device, const char *mntpnt)
{
    gchar *g_cmd = NULL;
    int res = 0;
    
    g_assert(device!=NULL);
    g_assert(mntpnt!=NULL);
    
    // try to mount
    if (mntd_mount_is_mounted(mntpnt) == 0) {
        g_cmd = g_strjoin(" ", MOUNT_BIN_PATH, "-o", "ro", device, mntpnt, NULL);
        if (g_cmd != NULL) {
            MSG_DEBUG("Mounting with '%s'", g_cmd);
            res = system(g_cmd);
            if (res == -1) {
                MSG_ERR("Error mounting '%s' on '%s': %s", device, mntpnt, strerror(errno));
                goto error;
            }
        } else {
            goto error;
        }
        
        // remounting, if needed
        MSG_DEBUG("trying to remount with user options from configfile ...");
        if (mntd_mount_is_mounted(mntpnt) == 1) {
            int r = -1;
            r = mntd_mount_remount_from_configfile(mntpnt);
            MSG_DEBUG("mntd_mount_remount_from_configfile('%s') returns %d", mntpnt, r);
        }

    } else {
        // return successful, if not mounted
        MSG_DEBUG("mount('%s') called, but it's already mounted -> ignoring", mntpnt);
    }
    
    goto cleanup;
    
error:
    res = -1;
    
cleanup:
    if (g_cmd != NULL) {
        g_free(g_cmd);
        g_cmd = NULL;
    }
    
    return res;
}


int 
mntd_mount_umount(const char *mntpnt)
{
    gchar *g_cmd = NULL;
    int res = 0;
    
    g_assert(mntpnt!=NULL);
    
    if (mntd_mount_is_mounted(mntpnt) == 1) {
        g_cmd = g_strjoin(" ", UMOUNT_BIN_PATH, "-f", "-l", mntpnt, NULL);
        if (g_cmd != NULL) {
            MSG_DEBUG("Unmounting with '%s'", g_cmd);
            res = system(g_cmd);
            if (res == -1) {
                MSG_ERR("Error unmounting '%s': %s", mntpnt, strerror(errno));
                goto error;
            }
        } else {
            goto error;
        }
    } else {
        // return successful, if not mounted
        MSG_DEBUG("unmount('%s') called, but it's not mounted -> ignoring", mntpnt);
    }
    
    goto cleanup;
    
error:
    res = -1;
    
cleanup:
    if (g_cmd != NULL) {
        g_free(g_cmd);
        g_cmd = NULL;
    }
    
    return res;
}


int 
_mntd_mount_remount(const char *user_opts, const char *mntpnt)
{
    gchar *g_joined = NULL;
    gchar *g_opts = NULL;
    gchar *g_cmd = NULL;
    int res = 0;
    
    g_assert(user_opts!=NULL);
    g_assert(mntpnt!=NULL);

    if (strlen(user_opts) > 0) {
        if (mntd_mount_is_mounted(mntpnt) == 1) {
            g_joined = g_strjoin(",", "remount", user_opts, NULL);
            if (g_joined != NULL) {
                g_opts = g_shell_quote(g_joined);
                if (g_opts != NULL) {
                    g_cmd = g_strjoin(" ", MOUNT_BIN_PATH, "-o", g_opts, mntpnt, NULL);
                    if (g_cmd != NULL) {
                        res = system(g_cmd);
                        if (res == -1) {
                            MSG_ERR("Error remounting '%s': %s", mntpnt, strerror(errno));
                            goto error;
                        }
                        MSG_DEBUG("Remounting with '%s' returns %d", g_cmd, res);
                    } else {
                        goto error;
                    }
                } else {
                    goto error;
                }
            } else {
                goto error;
            }
        }
    }
    
    goto cleanup;
    
error:
    res = -1;
    
cleanup:
    if (g_cmd != NULL) {
        g_free(g_cmd);
        g_cmd = NULL;
    }
    if (g_opts != NULL) {
        g_free(g_opts);
        g_opts = NULL;
    }
    if (g_joined != NULL) {
        g_free(g_joined);
        g_joined = NULL;
    }
    
    return res;
}


int 
mntd_mount_remount_rd(const char *mntpnt)
{
    int res = -1;
    
    g_assert(mntpnt!=NULL);

    if (mntd_mount_is_mounted(mntpnt) == 1) {
        res = _mntd_mount_remount("ro", mntpnt);
    }
    
    return res;
}


int 
mntd_mount_remount_rw(const char *mntpnt)
{
    int res = -1;
    
    g_assert(mntpnt!=NULL);

    if (mntd_mount_is_mounted(mntpnt) == 1) {
        res = _mntd_mount_remount("rw", mntpnt);
    }
    
    return res;
}


int 
mntd_mount_remount_from_configfile(const char *mntpnt)
{
    char *fsname = NULL;
    char *fsoptions = NULL;
    gchar *o = NULL;
    int res = -1;
    
    g_assert(mntpnt!=NULL);

    if (mntd_mount_is_mounted(mntpnt) == 1) {
        fsname = mntd_mount_getfsname(mntpnt);
        if (fsname != NULL) {
            fsoptions = mntd_mount_getoptions(mntpnt);
            if (fsoptions != NULL) {
                o = mntd_mount_normalize_options(g_hash_table_lookup(pmd->configdata->filesystems, 
                    fsname));
                // no remount, if nothing configured
                if (o!=NULL) {
                    // only try to remount, if options are different
                    if (strcmp(fsoptions, o) != 0) {
                        // remount with options from configfile
                        res = _mntd_mount_remount(o, mntpnt);
                        if (res == -1) {
                            MSG_WARNING("Remount '%s' with options from config '%s' failed -> falling back to standard options", 
                                mntpnt, o);
                            res = _mntd_mount_remount(fsoptions, mntpnt);
                        }
                    } else {
                        MSG_DEBUG("mtab options are identical to configfile -> nothing to be done.");
                        res = 0;
                    }
                    g_free(o);
                } else {
                    MSG_DEBUG("No options for filesystem '%s' in configfile found.", 
                        fsname);
                    res = 0;
                }
                g_free(fsoptions);
            } else {
                MSG_ERR("Couldn't get fsoptions from mtab for '%s'", mntpnt);
            }
            free(fsname);
        } else {
            MSG_ERR("Couldn't get fsname from mtab for '%s'", mntpnt);
        }
    } else {
        MSG_ERR("mntd_mount_remount_from_configfile('%s') called, but it's not mounted", mntpnt);
    }
    
    return res;
}


FILE *
mntd_mount_open_mtab(void)
{
    FILE *mtab = NULL;
    
    // try to open mount table
    mtab = setmntent("/etc/mtab", "r");
    if (mtab==NULL) {
        mtab = setmntent("/proc/mounts", "r");
        if (mtab==NULL) {
            return NULL;
        }
    }
    
    return mtab;
}
    

int 
mntd_mount_is_mounted(const char *path)
{
    int res = 0;
    FILE *mtab = NULL;
    struct mntent *me = NULL;
    
    // try to open mount table
    mtab = mntd_mount_open_mtab();
    if (mtab==NULL) {
        return 0;
    }
    
    // check entries
    while ((me = getmntent(mtab)) != 0) {
        if ((strcmp(path, me->mnt_dir) == 0) || 
             (strcmp(path, me->mnt_fsname) == 0)) {
            res = 1;
            break;
        }
    }
    endmntent(mtab);
    
    return res;
}


struct mntent * 
mntd_mount_getmntent(const char *path)
{
    struct mntent *res = NULL;
    FILE *mtab = NULL;
    struct mntent *me = NULL;
    
    // try to open mount table
    mtab = mntd_mount_open_mtab();
    if (mtab==NULL) {
        return NULL;
    }
    
    // check entries
    while ((me = getmntent(mtab)) != 0) {
        if ((strcmp(path, me->mnt_dir) == 0) || 
             (strcmp(path, me->mnt_fsname) == 0)) {
            res = (struct mntent *) malloc(sizeof(struct mntent));
            if (res != NULL) {
                res->mnt_fsname = strdup(me->mnt_fsname);
                res->mnt_dir = strdup(me->mnt_dir);
                res->mnt_type = strdup(me->mnt_type);
                res->mnt_opts = strdup(me->mnt_opts);
                res->mnt_freq = me->mnt_freq;
                res->mnt_passno = me->mnt_passno;
            }
            break;
        }
    }
    endmntent(mtab);
    
    return res;
}


char *
mntd_mount_getfsname(const char *path)
{
    char *res = NULL;
    FILE *mtab = NULL;
    struct mntent *me = NULL;
    
    // try to open mount table
    mtab = mntd_mount_open_mtab();
    if (mtab==NULL) {
        return NULL;
    }
    
    // check entries
    while ((me = getmntent(mtab)) != 0) {
        if ((strcmp(path, me->mnt_dir) == 0) || 
             (strcmp(path, me->mnt_fsname) == 0)) {
            res = strdup(me->mnt_type);
            break;
        }
    }
    endmntent(mtab);
    
    return res;
}


gchar *
mntd_mount_getoptions(const char *path)
{
    char *res = NULL;
    FILE *mtab = NULL;
    struct mntent *me = NULL;
    
    // try to open mount table
    mtab = mntd_mount_open_mtab();
    if (mtab==NULL) {
        return NULL;
    }
    
    // check entries
    while ((me = getmntent(mtab)) != 0) {
        if ((strcmp(path, me->mnt_dir) == 0) || 
             (strcmp(path, me->mnt_fsname) == 0)) {
            res = mntd_mount_normalize_options(me->mnt_opts);
            break;
        }
    }
    endmntent(mtab);
    
    return res;
}


gchar *
mntd_mount_normalize_options(const char *options)
{
    gchar **ov = NULL;
    gchar **oe = NULL;
    gchar *o = NULL;
    char *res = NULL;
    
    if (options != NULL) {
        o = g_strdup(options);
        if (o != NULL) {
            ov = g_strsplit(g_strstrip(o), ",", 0);
            if (ov != NULL) {
                oe = ov;
                while (*oe != NULL) {
                    *oe = g_strstrip(*oe);
                    oe++;
                }
                res = (char *) g_strjoinv(",", ov);
                g_strfreev(ov);
            }
            g_free(o);
        }
    }

    return res;
}

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