Initial import

[samba] / source / client / smbumount.c

diff --git a/source/client/smbumount.c b/source/client/smbumount.c
new file mode 100644 (file)
index 0000000..7ad7ed2
--- /dev/null
+++ b/source/client/smbumount.c
@@ -0,0 +1,192 @@
+/*
+ *  smbumount.c
+ *
+ *  Copyright (C) 1995-1998 by Volker Lendecke
+ *
+ */
+
+#define SMBMOUNT_MALLOC 1
+
+#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_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;
+}
+
+/* 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;
+}