check_device.c

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#include "config.h"
#include "check_device.h"

#include <stdio.h>
#include <sys/stat.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <libintl.h>

#include "len.h"
#include "output.h"

struct mnt_info {
        int mntid;
        int parentid;
        int major;
        int minor;
        char *root;
        char *mntpoint;
        char *mntopts1;
        char *fstype;
        char *mntsrc;
        char *mntopts2;
};

int readmountinfo(struct mnt_info ***collection);

int readmountinfo(struct mnt_info ***collection)
{
        char *line = NULL;
        size_t s = 0;
        ssize_t readsize = 0;
        FILE *fp = fopen("/proc/self/mountinfo", "r");
        if (fp == NULL)
        {
                error(_("cannot open file '%s': %s"), "/proc/self/mountinfo", strerror(errno));
                return 0;
        }

        int mntid = 0;
        int parentid = 0;
        int major = 0;
        int minor = 0;
        char *root = NULL;
        char *mntpoint = NULL;
        char *mntopts1 = NULL;
        char *fstype = NULL;
        char *mntsrc = NULL;
        char *mntopts2 = NULL;
        struct mnt_info **ptr = NULL;
        int n = 0;

        while((readsize = getline(&line, &s, fp)) != -1)
        {
                if(line[readsize - 1] == '\n')
                        line[--readsize] = '\0';

                mntid = 0;
                parentid = 0;
                major = 0;
                minor = 0;
                root = malloc(readsize);
                mntpoint = malloc(readsize);
                mntopts1 = malloc(readsize);
                fstype = malloc(readsize);
                mntsrc = malloc(readsize);
                mntopts2 = malloc(readsize);

                if(sscanf(line, "%d %d %d:%d %[^%#= ] %[^%#= ] %[^ ]%*[^-]- %[^%#= ] %[^%#= ] %s", &mntid, &parentid, &major, &minor, root, mntpoint, mntopts1, fstype, mntsrc, mntopts2) == 10)
                {
                        *collection = (struct mnt_info **)realloc(*collection, (n + 1) * sizeof(struct mnt_info *));
                        ptr = *collection + n;
                        *ptr = (struct mnt_info *)malloc(sizeof(struct mnt_info));
                        (*ptr)->mntid = mntid;
                        (*ptr)->parentid = parentid;
                        (*ptr)->major = major;
                        (*ptr)->minor = minor;
                        (*ptr)->root = strdup(root);
                        (*ptr)->mntpoint = strdup(mntpoint);
                        (*ptr)->mntopts1 = strdup(mntopts1);
                        (*ptr)->fstype = strdup(fstype);
                        (*ptr)->mntsrc = strdup(mntsrc);
                        (*ptr)->mntopts2 = strdup(mntopts2);
                        n++;
                }
                free(root);
                free(mntpoint);
                free(mntopts1);
                free(fstype);
                free(mntsrc);
                free(mntopts2);
                free(line);
                line = root = mntpoint = mntopts1 = fstype = mntsrc = mntopts2 = NULL;
        }
        return n;
}

int check_device(const char *file, const char *dev)
{
        if(str_len(file) == 0 || str_len(dev) == 0)
        {
                debug(_("wrong call to function %s"), "check_device(const char*, const char*)");
                debug(_("One of the parameters has a zero length"));
                return -1;
        }

        struct stat sb_file, sb_dev;

        debug(_("Check if file '%s' is on device '%s'."), file, dev);
        if(stat(file, &sb_file) == 0)
        {
                if(stat(dev, &sb_dev) == 0)
                {
                        if(S_ISBLK(sb_dev.st_mode) && sb_file.st_dev == sb_dev.st_rdev)
                        {
                                debug(_("file '%s' is on device '%s'"), file, dev);
                                return 0;
                        }
                }
        }
        else
        {
                output(LOG_WARNING, _("cannot stat file: %s"), file);
                return -1;
        }

        int minor_file = minor(sb_file.st_dev);
        int major_file = major(sb_file.st_dev);

        struct mnt_info **mntinfo = NULL;
        int j = readmountinfo(&mntinfo);
        int n = 0;

        while(n < j)
        {
                if(mntinfo[n]->major == major_file && mntinfo[n]->minor == minor_file && strcmp(mntinfo[n]->mntsrc, dev) == 0)
                {
                        debug(_("file '%s' is on device '%s'"), file, dev);
                        return 0;
                }
                n++;
        }
        output(LOG_NOTICE, _("file '%s' is not device '%s'"), file, dev);
        return -1;
}