diff options
Diffstat (limited to 'source/client/smbumount.c')
| -rw-r--r-- | source/client/smbumount.c | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/source/client/smbumount.c b/source/client/smbumount.c new file mode 100644 index 00000000000..9ea3083a6f9 --- /dev/null +++ b/source/client/smbumount.c @@ -0,0 +1,186 @@ +/* + * smbumount.c + * + * Copyright (C) 1995-1998 by Volker Lendecke + * + */ + +#include "includes.h" + +#include <mntent.h> + +#include <asm/types.h> +#include <asm/posix_types.h> +#include <linux/smb.h> +#include <linux/smb_mount.h> +#include <linux/smb_fs.h> + +/* This is a (hopefully) temporary hack due to the fact that + sizeof( uid_t ) != sizeof( __kernel_uid_t ) under glibc. + This may change in the future and smb.h may get fixed in the + future. In the mean time, it's ugly hack time - get over it. +*/ +#undef SMB_IOC_GETMOUNTUID +#define SMB_IOC_GETMOUNTUID _IOR('u', 1, __kernel_uid_t) + +#ifndef O_NOFOLLOW +#define O_NOFOLLOW 0400000 +#endif + +static void +usage(void) +{ + printf("usage: smbumount mountpoint\n"); +} + +static int +umount_ok(const char *mount_point) +{ + /* 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_uid_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_GETMOUNTUID, &mount_uid) != 0) { + fprintf(stderr, "%s probably not smb-filesystem\n", + mount_point); + return -1; + } + + if ((getuid() != 0) + && (mount_uid != getuid())) { + fprintf(stderr, "You are not allowed to umount %s\n", + mount_point); + return -1; + } + + close(fid); + return 0; +} + +/* Make a canonical pathname from PATH. Returns a freshly malloced string. + It is up the *caller* to ensure that the PATH is sensible. i.e. + canonicalize ("/dev/fd0/.") returns "/dev/fd0" even though ``/dev/fd0/.'' + is not a legal pathname for ``/dev/fd0'' Anything we cannot parse + we return unmodified. */ +static char * +canonicalize (char *path) +{ + 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[]) +{ + 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; +} |