Better detects dm-ioctl secure flag using version before use.

git-svn-id: https://cryptsetup.googlecode.com/svn/trunk@435 36d66b0a-2a48-0410-832c-cd162a569da5

diff --git a/lib/internal.h b/lib/internal.h
index dc6dce0..7b42082 100644 (file)
--- a/lib/internal.h
+++ b/lib/internal.h
@@ -57,9 +57,10 @@ void set_error_va(const char *fmt, va_list va);
 void set_error(const char *fmt, ...);
 const char *get_error(void);
 
-/* Device mapper backend */
-#define DM_KEY_WIPE_SUPPORTED (1 << 0) /* kernel supports key wipe message */
-#define DM_LMK_SUPPORTED      (1 << 1) /* kernel supports lmk mode */
+/* Device mapper backend - kernel support flags */
+#define DM_KEY_WIPE_SUPPORTED (1 << 0) /* key wipe message */
+#define DM_LMK_SUPPORTED      (1 << 1) /* lmk mode */
+#define DM_SECURE_SUPPORTED   (1 << 2) /* wipe (secure) buffer flag */
 uint32_t dm_flags(void);
 
 const char *dm_get_dir(void);

diff --git a/lib/libdevmapper.c b/lib/libdevmapper.c
index c4b1f12..3e9c607 100644 (file)
--- a/lib/libdevmapper.c
+++ b/lib/libdevmapper.c
@@ -77,18 +77,28 @@ static void set_dm_error(int level, const char *file, int line,
 
 static int _dm_simple(int task, const char *name, int udev_wait);
 
-static void _dm_set_crypt_compat(int maj, int min, int patch)
+static void _dm_set_crypt_compat(const char *dm_version, unsigned crypt_maj,
+                                unsigned crypt_min, unsigned crypt_patch)
 {
-       log_dbg("Detected dm-crypt target of version %i.%i.%i.", maj, min, patch);
+       unsigned dm_maj, dm_min, dm_patch;
 
-       if (maj >= 1 && min >=2)
+       if (sscanf(dm_version, "%u.%u.%u", &dm_maj, &dm_min, &dm_patch) != 3)
+               dm_maj = dm_min = dm_patch = 0;
+
+       log_dbg("Detected dm-crypt version %i.%i.%i, dm-ioctl version %u.%u.%u.",
+               crypt_maj, crypt_min, crypt_patch, dm_maj, dm_min, dm_patch);
+
+       if (crypt_maj >= 1 && crypt_min >= 2)
                _dm_crypt_flags |= DM_KEY_WIPE_SUPPORTED;
        else
                log_dbg("Suspend and resume disabled, no wipe key support.");
 
-       if (maj >= 1 && min >=10)
+       if (crypt_maj >= 1 && crypt_min >= 10)
                _dm_crypt_flags |= DM_LMK_SUPPORTED;
 
+       if (dm_maj >= 4 && dm_min >= 20)
+               _dm_crypt_flags |= DM_SECURE_SUPPORTED;
+
        _dm_crypt_checked = 1;
 }
 
@@ -96,6 +106,7 @@ static int _dm_check_versions(void)
 {
        struct dm_task *dmt;
        struct dm_versions *target, *last_target;
+       char dm_version[16];
 
        if (_dm_crypt_checked)
                return 1;
@@ -108,13 +119,19 @@ static int _dm_check_versions(void)
                return 0;
        }
 
+       if (!dm_task_get_driver_version(dmt, dm_version, sizeof(dm_version))) {
+               dm_task_destroy(dmt);
+               return 0;
+       }
+
        target = dm_task_get_versions(dmt);
        do {
                last_target = target;
                if (!strcmp(DM_CRYPT_TARGET, target->name)) {
-                       _dm_set_crypt_compat((int)target->version[0],
-                                            (int)target->version[1],
-                                            (int)target->version[2]);
+                       _dm_set_crypt_compat(dm_version,
+                                            (unsigned)target->version[0],
+                                            (unsigned)target->version[1],
+                                            (unsigned)target->version[2]);
                }
                target = (void *) target + target->next;
        } while (last_target != target);
@@ -474,7 +491,7 @@ int dm_create_device(const char *name,
                        goto out_no_removal;
        }
 
-       if (!dm_task_secure_data(dmt))
+       if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
                goto out_no_removal;
        if (read_only && !dm_task_set_ro(dmt))
                goto out_no_removal;
@@ -600,7 +617,7 @@ int dm_query_device(const char *name,
 
        if (!(dmt = dm_task_create(DM_DEVICE_TABLE)))
                goto out;
-       if (!dm_task_secure_data(dmt))
+       if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
                goto out;
        if (!dm_task_set_name(dmt, name))
                goto out;
@@ -707,7 +724,7 @@ static int _dm_message(const char *name, const char *msg)
        if (!(dmt = dm_task_create(DM_DEVICE_TARGET_MSG)))
                return 0;
 
-       if (!dm_task_secure_data(dmt))
+       if ((dm_flags() & DM_SECURE_SUPPORTED) && !dm_task_secure_data(dmt))
                goto out;
 
        if (name && !dm_task_set_name(dmt, name))