tls: in AES-GCM decoding, avoid memmove

[oweals/busybox.git] / util-linux / umount.c

diff --git a/util-linux/umount.c b/util-linux/umount.c
index 00910977d5c91035ab7af91c98128ce923ab7827..e2329f8b34c42a383e3ba58b97f17c099c216d7d 100644 (file)
--- a/util-linux/umount.c
+++ b/util-linux/umount.c
@@ -7,6 +7,39 @@
  *
  * Licensed under GPLv2, see file LICENSE in this source tree.
  */
+//config:config UMOUNT
+//config:      bool "umount (4.5 kb)"
+//config:      default y
+//config:      select PLATFORM_LINUX
+//config:      help
+//config:      When you want to remove a mounted filesystem from its current mount
+//config:      point, for example when you are shutting down the system, the
+//config:      'umount' utility is the tool to use. If you enabled the 'mount'
+//config:      utility, you almost certainly also want to enable 'umount'.
+//config:
+//config:config FEATURE_UMOUNT_ALL
+//config:      bool "Support -a (unmount all)"
+//config:      default y
+//config:      depends on UMOUNT
+//config:      help
+//config:      Support -a option to unmount all currently mounted filesystems.
+
+//applet:IF_UMOUNT(APPLET_NOEXEC(umount, umount, BB_DIR_BIN, BB_SUID_DROP, umount))
+/*
+ * On one hand, in some weird situations you'd want umount
+ * to not do anything surprising, to behave as a usual fork+execed executable.
+ *
+ * OTOH, there can be situations where execing would not succeed, or even hang
+ * (say, if executable is on a filesystem which is in trouble and accesses to it
+ * block in kernel).
+ * In this case, you might be actually happy if your standalone bbox shell
+ * does not fork+exec, but only forks and calls umount_main() which it already has!
+ * Let's go with NOEXEC.
+ *
+ * bb_common_bufsiz1 usage here is safe wrt NOEXEC: not expecting it to be zeroed.
+ */
+
+//kbuild:lib-$(CONFIG_UMOUNT) += umount.o
 
 //usage:#define umount_trivial_usage
 //usage:       "[OPTIONS] FILESYSTEM|DIRECTORY"
@@ -22,15 +55,20 @@
 //usage:     "\n       -l      Lazy umount (detach filesystem)"
 //usage:     "\n       -f      Force umount (i.e., unreachable NFS server)"
 //usage:       IF_FEATURE_MOUNT_LOOP(
-//usage:     "\n       -D      Don't free loop device even if it has been used"
+//usage:     "\n       -d      Free loop device if it has been used"
 //usage:       )
+//usage:     "\n       -t FSTYPE[,...] Unmount only these filesystem type(s)"
 //usage:
 //usage:#define umount_example_usage
 //usage:       "$ umount /dev/hdc1\n"
 
 #include <mntent.h>
 #include <sys/mount.h>
+#ifndef MNT_DETACH
+# define MNT_DETACH 0x00000002
+#endif
 #include "libbb.h"
+#include "common_bufsiz.h"
 
 #if defined(__dietlibc__)
 // TODO: This does not belong here.
@@ -44,22 +82,14 @@ static struct mntent *getmntent_r(FILE* stream, struct mntent* result,
 }
 #endif
 
-/* Ignored: -v -t -i
- * bbox always acts as if -d is present.
- * -D can be used to suppress it (bbox extension).
- * Rationale:
- * (1) util-linux's umount does it if "loop=..." is seen in /etc/mtab:
- * thus, on many systems, bare umount _does_ drop loop devices.
- * (2) many users request this feature.
- */
-#define OPTION_STRING           "fldDnra" "vt:i"
+/* ignored: -c -v -i */
+#define OPTION_STRING           "fldnrat:" "cvi"
 #define OPT_FORCE               (1 << 0) // Same as MNT_FORCE
 #define OPT_LAZY                (1 << 1) // Same as MNT_DETACH
-//#define OPT_FREE_LOOP           (1 << 2) // -d is assumed always present
-#define OPT_DONT_FREE_LOOP      (1 << 3)
-#define OPT_NO_MTAB             (1 << 4)
-#define OPT_REMOUNT             (1 << 5)
-#define OPT_ALL                 (ENABLE_FEATURE_UMOUNT_ALL ? (1 << 6) : 0)
+#define OPT_FREELOOP            (1 << 2)
+#define OPT_NO_MTAB             (1 << 3)
+#define OPT_REMOUNT             (1 << 4)
+#define OPT_ALL                 (ENABLE_FEATURE_UMOUNT_ALL ? (1 << 5) : 0)
 
 int umount_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int umount_main(int argc UNUSED_PARAM, char **argv)
@@ -99,9 +129,10 @@ int umount_main(int argc UNUSED_PARAM, char **argv)
                if (opt & OPT_ALL)
                        bb_error_msg_and_die("can't open '%s'", bb_path_mtab_file);
        } else {
-               while (getmntent_r(fp, &me, bb_common_bufsiz1, sizeof(bb_common_bufsiz1))) {
-                       /* Match fstype if passed */
-                       if (!match_fstype(&me, fstype))
+               setup_common_bufsiz();
+               while (getmntent_r(fp, &me, bb_common_bufsiz1, COMMON_BUFSIZE)) {
+                       /* Match fstype (fstype==NULL matches always) */
+                       if (!fstype_matches(me.mnt_type, fstype))
                                continue;
                        m = xzalloc(sizeof(*m));
                        m->next = mtl;
@@ -113,7 +144,8 @@ int umount_main(int argc UNUSED_PARAM, char **argv)
        }
 
        // If we're not umounting all, we need at least one argument.
-       if (!(opt & OPT_ALL) && !fstype) {
+       // Note: "-t FSTYPE" does not imply -a.
+       if (!(opt & OPT_ALL)) {
                if (!argv[0])
                        bb_show_usage();
                m = NULL;
@@ -181,7 +213,7 @@ int umount_main(int argc UNUSED_PARAM, char **argv)
                } else {
                        // De-allocate the loop device.  This ioctl should be ignored on
                        // any non-loop block devices.
-                       if (ENABLE_FEATURE_MOUNT_LOOP && !(opt & OPT_DONT_FREE_LOOP) && m)
+                       if (ENABLE_FEATURE_MOUNT_LOOP && (opt & OPT_FREELOOP) && m)
                                del_loop(m->device);
                        if (ENABLE_FEATURE_MTAB_SUPPORT && !(opt & OPT_NO_MTAB) && m)
                                erase_mtab(m->dir);