client/smbumount.c

ソースコードを見る。

関数
static void	usage (void)
static int	umount_ok (const char *mount_point)
static char *	canonicalize (char *path)
int	main (int argc, char *argv[])

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関数

static void usage

(

void

)

[static]

smbumount.c の 33 行で定義されています。

参照先 printf().

{
        printf("usage: smbumount mountpoint\n\n");
        printf("Please be aware that smbfs is deprecated in favor of "
               "cifs\n");
}

static int umount_ok

(

const char *

mount_point

)

[static]

smbumount.c の 41 行で定義されています。

参照先 errno・fprintf()・mount_uid・strerror().

参照元 main().

{
        /* we set O_NOFOLLOW to prevent users playing games with symlinks to
           umount filesystems they don't own */
        int fid = open(mount_point, O_RDONLY|O_NOFOLLOW, 0);
        __kernel_uid32_t mount_uid;
        
        if (fid == -1) {
                fprintf(stderr, "Could not open %s: %s\n",
                        mount_point, strerror(errno));
                return -1;
        }
        
        if (ioctl(fid, SMB_IOC_GETMOUNTUID32, &mount_uid) != 0) {
                __kernel_uid_t mount_uid16;
                if (ioctl(fid, SMB_IOC_GETMOUNTUID, &mount_uid16) != 0) {
                        fprintf(stderr, "%s probably not smb-filesystem\n",
                                mount_point);
                        return -1;
                }
                mount_uid = mount_uid16;
        }

        if ((getuid() != 0)
            && (mount_uid != getuid())) {
                fprintf(stderr, "You are not allowed to umount %s\n",
                        mount_point);
                return -1;
        }

        close(fid);
        return 0;
}

static char* canonicalize

(

char *

path

)

[static]

smbumount.c の 81 行で定義されています。

参照先 fprintf().

参照元 main().

{
        char *canonical = malloc (PATH_MAX + 1);

        if (!canonical) {
                fprintf(stderr, "Error! Not enough memory!\n");
                return NULL;
        }

        if (strlen(path) > PATH_MAX) {
                fprintf(stderr, "Mount point string too long\n");
                return NULL;
        }

        if (path == NULL)
                return NULL;
  
        if (realpath (path, canonical))
                return canonical;

        strncpy (canonical, path, PATH_MAX);
        canonical[PATH_MAX] = '\0';
        return canonical;
}

int main	(	int	argc,
		char *	argv[]
	)

smbumount.c の 108 行で定義されています。

参照先 canonicalize()・errno・fd・fprintf()・strerror()・umount_ok()・usage().

{
        int fd;
        char* mount_point;
        struct mntent *mnt;
        FILE* mtab;
        FILE* new_mtab;

        if (argc != 2) {
                usage();
                exit(1);
        }

        if (geteuid() != 0) {
                fprintf(stderr, "smbumount must be installed suid root\n");
                exit(1);
        }

        mount_point = canonicalize(argv[1]);

        if (mount_point == NULL)
        {
                exit(1);
        }

        if (umount_ok(mount_point) != 0) {
                exit(1);
        }

        if (umount(mount_point) != 0) {
                fprintf(stderr, "Could not umount %s: %s\n",
                        mount_point, strerror(errno));
                exit(1);
        }

        if ((fd = open(MOUNTED"~", O_RDWR|O_CREAT|O_EXCL, 0600)) == -1)
        {
                fprintf(stderr, "Can't get "MOUNTED"~ lock file");
                return 1;
        }
        close(fd);
        
        if ((mtab = setmntent(MOUNTED, "r")) == NULL) {
                fprintf(stderr, "Can't open " MOUNTED ": %s\n",
                        strerror(errno));
                return 1;
        }

#define MOUNTED_TMP MOUNTED".tmp"

        if ((new_mtab = setmntent(MOUNTED_TMP, "w")) == NULL) {
                fprintf(stderr, "Can't open " MOUNTED_TMP ": %s\n",
                        strerror(errno));
                endmntent(mtab);
                return 1;
        }

        while ((mnt = getmntent(mtab)) != NULL) {
                if (strcmp(mnt->mnt_dir, mount_point) != 0) {
                        addmntent(new_mtab, mnt);
                }
        }

        endmntent(mtab);

        if (fchmod (fileno (new_mtab), S_IRUSR|S_IWUSR|S_IRGRP|S_IROTH) < 0) {
                fprintf(stderr, "Error changing mode of %s: %s\n",
                        MOUNTED_TMP, strerror(errno));
                exit(1);
        }

        endmntent(new_mtab);

        if (rename(MOUNTED_TMP, MOUNTED) < 0) {
                fprintf(stderr, "Cannot rename %s to %s: %s\n",
                        MOUNTED, MOUNTED_TMP, strerror(errno));
                exit(1);
        }

        if (unlink(MOUNTED"~") == -1)
        {
                fprintf(stderr, "Can't remove "MOUNTED"~");
                return 1;
        }

        return 0;
}       

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