New API call iso_write_opts_set_scdbackup_tag()

doc/checksums.txt

@@ -67,8 +67,8 @@ The tree checksum tag is written after the  ECMA-119 directory entries.
 The session checksum tag is written after all payload including the checksum
 array. (Then follows eventual padding.)
 
-The tags are single lines of printable text, padded by 0 bytes. They have
-the following format:
+The tags are single lines of printable text at the very beginning of a block
+of 2048 bytes. They have the following format:
 
  Tag_id pos=# range_start=# range_size=# [session_start|next=#] md5=# self=#\n
 
@@ -161,9 +161,14 @@ checksums as strings of 32 hex digits.
   The MD5 checksum of the tag itself up to and including the last hex digit of
   parameter "md5=".
   
-  The newline character at the end is mandatory. For now all bytes of the
-  block after that newline shall be zero. There may arise future extensions.
-
+The newline character at the end is mandatory. After that newline there may
+follow more lines. Their meaning is not necessarily described in this document.
+
+One such line type is the scdbackup checksum tag, an ancestor of libisofs tags
+which is suitable only for single session images which begin at LBA 0. It bears
+a checksum record which by its MD5 covers all bytes from LBA 0 up to the
+newline character preceding the scdbackup tag. See scdbackup/README appendix
+VERIFY for details.
 
 -------------------------------------------------------------------------------
 

libisofs/ecma119.c

@@ -31,11 +31,13 @@
 #include "md5.h"
 #endif
 
+#include <ctype.h>
 #include <stdlib.h>
 #include <time.h>
 #include <string.h>
 #include <locale.h>
 #include <langinfo.h>
+#include <stdio.h>
 
 /*
  * TODO #00011 : guard against bad path table usage with more than 65535 dirs
@@ -1132,6 +1134,7 @@ int ecma119_image_new(IsoImage *src, IsoWriteOpts *opts, Ecma119Image **img)
 
     target->md5_file_checksums = opts->md5_file_checksums;
     target->md5_session_checksum = opts->md5_session_checksum;
+    strcpy(target->scdbackup_tag_parm, opts->scdbackup_tag_parm);
     target->checksum_idx_counter = 0;
     target->checksum_ctx = NULL;
     target->checksum_counter = 0;
@@ -1866,6 +1869,39 @@ int iso_write_opts_set_record_md5(IsoWriteOpts *opts, int session, int files)
     return ISO_SUCCESS;
 }
 
+int iso_write_opts_set_scdbackup_tag(IsoWriteOpts *opts,
+                                     char *name, char *timestamp)
+{
+
+#ifdef Libisofs_with_checksumS
+
+    char eff_name[81], eff_time[19];
+    int i;
+
+    for (i = 0; name[i] != 0 && i < 80; i++)
+         if (isspace((int) ((unsigned char *) name)[i]))
+             eff_name[i] = '_';
+         else
+             eff_name[i] = name[i];
+    if (i == 0)
+        eff_name[i++] = '_';
+    eff_name[i] = 0;
+    for (i = 0; timestamp[i] != 0 && i < 18; i++)
+         if (isspace((int) ((unsigned char *) timestamp)[i]))
+             eff_time[i] = '_';
+         else
+             eff_time[i] = timestamp[i];
+    if (i == 0)
+        eff_time[i++] = '_';
+    eff_time[i] = 0;
+
+    sprintf(opts->scdbackup_tag_parm, "%s %s", eff_name, eff_time);
+
+#endif /* Libisofs_with_checksumS */
+
+    return ISO_SUCCESS;
+}
+
 int iso_write_opts_set_replace_mode(IsoWriteOpts *opts, int dir_mode,
                                     int file_mode, int uid, int gid)
 {

libisofs/ecma119.h

@@ -281,6 +281,15 @@ struct iso_write_opts {
      */
     uint32_t data_start_lba;
 
+    /**
+     * If not empty: A text holding parameters "name" and "timestamp" for
+     * a scdbackup stream checksum tag. See scdbackup/README appendix VERIFY.
+     * It makes sense only for single session images which start at LBA 0.
+     * Such a tag may be part of a libisofs checksum tag block after the
+     * session tag line. It then covers the whole session up to its own start
+     * position.
+     */
+    char scdbackup_tag_parm[100];
 };
 
 typedef struct ecma119_image Ecma119Image;
@@ -464,6 +473,8 @@ struct ecma119_image
            is submitted with ecma119_image_new() ?
      */
 
+    char scdbackup_tag_parm[96];
+
 #endif /* Libisofs_with_checksumS */
 
     /* Buffer for communication between burn_source and writer thread */

libisofs/libisofs.h

@@ -1446,6 +1446,27 @@ int iso_write_opts_set_sort_files(IsoWriteOpts *opts, int sort);
  */
 int iso_write_opts_set_record_md5(IsoWriteOpts *opts, int session, int files);
 
+/**
+ * Set the parameters "name" and "timestamp" for a scdbackup checksum tag.
+ * It will be appended to the libisofs session tag if the image starts at
+ * LBA 0 (see iso_write_opts_set_ms_block()). The scdbackup tag can be used
+ * to verify the image by command scdbackup_verify <device> -auto_end.
+ * See scdbackup/README appendix VERIFY for its inner details.
+ *
+ * @param name
+ *      A word of up to 80 characters. Typically <volno>_<totalno> telling
+ *      that this is volume <volno> of a total of <totalno> volumes.
+ * @param timestamp
+ *      A string of 13 characters YYMMDD.hhmmss (e.g. A90831.190324).
+ *      A9 = 2009, B0 = 2010, B1 = 2011, ... C0 = 2020, ...
+ * @return
+ *      1 indicates success, <0 is error
+ *
+ * @since 0.6.24
+ */
+int iso_write_opts_set_scdbackup_tag(IsoWriteOpts *opts,
+                                     char *name, char *timestamp);
+
 /**
  * Whether to set default values for files and directory permissions, gid and
  * uid. All these take one of three values: 0, 1 or 2.
@@ -5522,6 +5543,13 @@ int iso_md5_match(char first_md5[16], char second_md5[16]);
 */
 #define ISO_MD5_STREAM_CHANGE     0xE430FE9A
 
+/**
+ * Session does not start at LBA 0. scdbackup checksum tag not written.
+ * (WARNING, HIGH, -359)
+ * @since 0.6.24
+*/
+#define ISO_SCDBACKUP_TAG_NOT_0   0xD030FE99
+
 
 /* ! PLACE NEW ERROR CODES HERE ! */
 

libisofs/md5.c

@@ -698,6 +698,66 @@ int checksum_writer_create(Ecma119Image *target)
 }
 
 
+static
+int iso_md5_write_scdbackup_tag(Ecma119Image *t, char *tag_block, int flag)
+{
+
+#ifdef Libisofs_with_checksumS
+
+    void *ctx = NULL;
+    off_t pos = 0, line_start;
+    int record_len, block_len, res, i;
+    char postext[20], md5[16], record[160];
+
+    line_start = strlen(tag_block);
+    iso_md5_compute(t->checksum_ctx, tag_block, line_start);
+    res = iso_md5_clone(t->checksum_ctx, &ctx);
+    if (res < 0)
+        goto ex;
+    res = iso_md5_end(&ctx, md5);
+
+    pos = (off_t) t->checksum_tag_pos * (off_t) 2048 + line_start;
+    if(pos >= 1000000000)
+        sprintf(postext, "%u%9.9u", (unsigned int) (pos / 1000000000),
+                                    (unsigned int) (pos % 1000000000));
+    else
+        sprintf(postext, "%u", (unsigned int) pos),
+
+    sprintf(record, "%s %s ", t->scdbackup_tag_parm, postext);
+    record_len = strlen(record);
+    for (i = 0; i < 16; i++)
+         sprintf(record + record_len + 2 * i,
+                 "%2.2x", ((unsigned char *) md5)[i]);
+    record_len+= 32;
+    res = iso_md5_start(&ctx);
+    if (res < 0)
+        goto ex;
+    iso_md5_compute(ctx, record, record_len);
+    iso_md5_end(&ctx, md5);
+
+    sprintf(tag_block + line_start, "scdbackup_checksum_tag_v0.1 %s %d %s ",
+            postext, record_len, record);
+    block_len = strlen(tag_block);
+    for (i = 0; i < 16; i++)
+        sprintf(tag_block + block_len + 2 * i,
+                "%2.2x", ((unsigned char *) md5)[i]);
+    block_len+= 32;
+    tag_block[block_len++]= '\n';
+
+    res = ISO_SUCCESS;
+ex:;
+    if (ctx != NULL)
+        iso_md5_end(&ctx, md5);
+    return res;
+
+#else
+
+    return ISO_SUCCESS;
+
+#endif /* Libisofs_with_checksumS */
+}
+
+
 /* Write stream detectable checksum tag to extra block.
  * @flag bit0-7= tag type
  *               1= session tag (End checksumming.)
@@ -719,11 +779,16 @@ int iso_md5_write_tag(Ecma119Image *t, int flag)
     start = t->checksum_range_start;
     memset(tag_block, 0, 2048);
     mode = flag & 255;
+    if (mode < 1 || mode > 4)
+        return ISO_WRONG_ARG_VALUE;
+    res = iso_md5_clone(t->checksum_ctx, &ctx);
+    if (res < 0)
+        return res;
+    res = iso_md5_end(&ctx, md5);
     if (mode == 1) {
-        res = iso_md5_end(&(t->checksum_ctx), md5);
         size = t->checksum_range_size;
         pos = t->checksum_tag_pos;
-    } else if (mode >= 2 && mode <= 4) {
+    } else {
         if (mode == 2) {
             pos = t->checksum_sb_tag_pos;
         } else if (mode == 3) {
@@ -733,46 +798,51 @@ int iso_md5_write_tag(Ecma119Image *t, int flag)
             start = pos - (pos % 32);
         }
         size = pos - start;
-        res = iso_md5_clone(t->checksum_ctx, &ctx);
-        if (res < 0)
-            return res;
-        res = iso_md5_end(&ctx, md5);
-    } else {
-        return ISO_WRONG_ARG_VALUE;
     }
-    if (res > 0) {
-        iso_util_tag_magic(mode, &tag_id, &tag_id_len, 0);
-        sprintf(tag_block,
-                "%s pos=%u range_start=%u range_size=%u",
-                tag_id, pos, start, size);
+    if (res < 0)
+        goto ex;
 
-        l = strlen(tag_block);
-        if (mode == 2) {
-            sprintf(tag_block + l, " next=%u", t->checksum_tree_tag_pos);
-        } else if (mode == 3) {
-            sprintf(tag_block + l, " next=%u", t->checksum_tag_pos);
-        } else if (mode == 4) {
-            sprintf(tag_block + l, " session_start=%u", t->ms_block);
-        }
-        strcat(tag_block + l, " md5=");
-        l = strlen(tag_block);
+    iso_util_tag_magic(mode, &tag_id, &tag_id_len, 0);
+    sprintf(tag_block, "%s pos=%u range_start=%u range_size=%u",
+            tag_id, pos, start, size);
+
+    l = strlen(tag_block);
+    if (mode == 2) {
+        sprintf(tag_block + l, " next=%u", t->checksum_tree_tag_pos);
+    } else if (mode == 3) {
+        sprintf(tag_block + l, " next=%u", t->checksum_tag_pos);
+    } else if (mode == 4) {
+        sprintf(tag_block + l, " session_start=%u", t->ms_block);
+    }
+    strcat(tag_block + l, " md5=");
+    l = strlen(tag_block);
+    for (i = 0; i < 16; i++)
+        sprintf(tag_block + l + 2 * i, "%2.2x",
+                ((unsigned char *) md5)[i]);
+    l+= 32;
+        
+    res = iso_md5_start(&ctx);
+    if (res > 0) {
+        iso_md5_compute(ctx, tag_block, l);
+        iso_md5_end(&ctx, md5);
+        strcpy(tag_block + l, " self=");
+        l += 6;
         for (i = 0; i < 16; i++)
             sprintf(tag_block + l + 2 * i, "%2.2x",
                     ((unsigned char *) md5)[i]);
-        l+= 32;
-        
-        res = iso_md5_start(&ctx);
-        if (res > 0) {
-            iso_md5_compute(ctx, tag_block, l);
-            iso_md5_end(&ctx, md5);
-            strcpy(tag_block + l, " self=");
-            l += 6;
-            for (i = 0; i < 16; i++)
-                sprintf(tag_block + l + 2 * i, "%2.2x",
-                        ((unsigned char *) md5)[i]);
+    }
+    tag_block[l + 32] = '\n';
+
+    if (mode == 1 && t->scdbackup_tag_parm[0]) {
+        if (t->ms_block > 0) {
+            iso_msg_submit(t->image->id, ISO_SCDBACKUP_TAG_NOT_0, 0, NULL);
+        } else {
+            res = iso_md5_write_scdbackup_tag(t, tag_block, 0);
+            if (res < 0)
+                goto ex;
         }
-        tag_block[l + 32] = '\n';
     }
+
     if (mode == 4) {
         if (t->opts_overwrite != NULL)
             memcpy(t->opts_overwrite + pos * 2048, tag_block, 2048);
@@ -783,6 +853,7 @@ int iso_md5_write_tag(Ecma119Image *t, int flag)
             goto ex;
         }
     }
+
     res = ISO_SUCCESS;
 ex:;
     if (ctx != NULL)

libisofs/messages.c

@@ -274,6 +274,8 @@ const char *iso_error_to_msg(int errcode)
         return "Checksum tag with unexpected address range encountered";
     case ISO_MD5_STREAM_CHANGE:
         return "Detected file content changes while it was written into the image";
+    case ISO_SCDBACKUP_TAG_NOT_0:
+        return "Session does not start at LBA 0. scdbackup checksum tag not written.";
     default:
         return "Unknown error";
     }