Better messages when aborting iso_image_import() due to checksum failure.

libisofs/fs_image.c

@@ -2323,8 +2323,8 @@ int iso_src_check_sb_tree(IsoDataSource *src, uint32_t start_lba, int flag)
         /* Relocated Superblock: restart checking at real session start */
         if (next_tag < 32) {
             /* Non plausible session_start address */
-            iso_msg_submit(-1, ret, 0, NULL);
             ret = ISO_SB_TREE_CORRUPTED;
+            iso_msg_submit(-1, ret, 0, NULL);
             goto ex;
         }
         /* Check real session */
@@ -2422,13 +2422,15 @@ int iso_image_filesystem_new(IsoDataSource *src, struct iso_read_opts *opts,
 #ifdef Libisofs_with_checksumS
 
     if (data->md5_load) {
-
         /* From opts->block on : check for superblock and tree tags */;
         ret = iso_src_check_sb_tree(src, opts->block, 0);
-        if (ret <= 0) {
-
-            /* >>> refuse to load, hint towards loading without MD5 check */;
-
+        if (ret < 0) {
+            iso_msgs_submit(0,
+                "Image loading aborted due to MD5 mismatch of image tree data",
+                            0, "FAILURE", 0);
+            iso_msgs_submit(0,
+                     "You may override this refusal by disabling MD5 checking",
+                            0, "HINT", 0);
             goto fs_cleanup;
         }
     }

libisofs/messages.c

@@ -277,6 +277,14 @@ const char *iso_error_to_msg(int errcode)
     }
 }
 
+int iso_msg_is_abort(int errcode)
+{
+    if (ISO_ERR_SEV(errcode) >= abort_threshold)
+        return 1;
+    return 0;
+}
+       
+
 int iso_msg_submit(int imgid, int errcode, int causedby, const char *fmt, ...)
 {
     char msg[MAX_MSG_LEN];
@@ -307,7 +315,7 @@ int iso_msg_submit(int imgid, int errcode, int causedby, const char *fmt, ...)
         }
     }
 
-    if (ISO_ERR_SEV(errcode) >= abort_threshold) {
+    if (iso_msg_is_abort(errcode)) {
         return ISO_CANCELED;
     } else {
         return 0;

libisofs/messages.h

@@ -24,6 +24,13 @@ extern int iso_message_id;
  */
 void iso_msg_debug(int imgid, const char *fmt, ...);
 
+
+/**
+ * Inquire whether the given error code triggers the abort threshold
+ */
+int iso_msg_is_abort(int errcode);
+
+
 /**
  * 
  * @param errcode
@@ -33,7 +40,7 @@ void iso_msg_debug(int imgid, const char *fmt, ...);
  *      < 0 will be returned in any case. Use 0 if there is no previous 
  *      cause for the error.
  * @return
- *      1 on success, < 0 if function must abort asap.
+ *      0 on success, < 0 if function must abort asap.
  */
 int iso_msg_submit(int imgid, int errcode, int causedby, const char *fmt, ...);