Enabled multi-session with partition offset

libisoburn/burn_wrap.c

@@ -1192,7 +1192,7 @@ int isoburn_emulate_toc(struct burn_drive *d, int flag)
    ret= isoburn_read_iso_head(d, lba, &image_size, NULL, 0);
    if(ret<=0)
      {ret= 0; goto failure;}
-   lba= Libisoburn_overwriteable_starT;
+   lba= o->target_iso_head_size / 2048;
    with_enclosure= 1;
    if((flag & 16) && o->emulation_mode == 1) {
      ret= 1;
@@ -1219,7 +1219,7 @@ int isoburn_emulate_toc(struct burn_drive *d, int flag)
      /* growisofs aligns to 16 rather than 32. Overwriteable TOC emulation
         relies on not accidentially seeing inter-session trash data.
         But one can safely access 16 blocks earlier because a xorriso header
-        would have overwritten with the unused 16 blocks at its start.
+        would have been overwritten with the unused 16 blocks at its start.
         If libisoburn alignment would increase, then this would not be
         possible any more.
      */

libisoburn/isoburn.c

@@ -115,7 +115,7 @@ struct isoburn *isoburn_list_start= NULL;
 int isoburn_new(struct isoburn **objpt, int flag)
 {
  struct isoburn *o;
- int i, ret;
+ int ret;
 
  *objpt= o= (struct isoburn *) malloc(sizeof(struct isoburn));
  if(o==NULL) {
@@ -137,8 +137,9 @@ int isoburn_new(struct isoburn **objpt, int flag)
  o->fabricated_disc_status= BURN_DISC_UNREADY;
  o->toc= NULL;
  o->wrote_well= -1;
- for(i=0;i<Libisoburn_target_head_sizE;i++)
-   o->target_iso_head[i]= 0;
+ o->loaded_partition_offset= 0;
+ o->target_iso_head_size= Libisoburn_target_head_sizE;
+ o->target_iso_head= NULL;
  o->image= NULL;
  o->iso_data_source= NULL;
  o->read_pacifier= NULL;
@@ -148,9 +149,15 @@ int isoburn_new(struct isoburn **objpt, int flag)
  o->msgs_submit_flag= 0;
  o->prev= NULL;
  o->next= NULL;
+ o->target_iso_head= calloc(1, o->target_iso_head_size);
+ if(o->target_iso_head == NULL) {
+   isoburn_report_iso_error(ISO_OUT_OF_MEM, "Cannot allocate overwrite buffer",
+                            0, "FATAL", 0);
+   goto failed;
+ }
  ret= iso_image_new("ISOIMAGE", &o->image);
  if(ret<0) {
-   isoburn_report_iso_error(ret, "Cannot create image", 0, "FATAL", 0);
+   isoburn_report_iso_error(ret, "Cannot create image object", 0, "FATAL", 0);
    goto failed;
  }
  isoburn_link(o, isoburn_list_start, 1);
@@ -188,6 +195,8 @@ int isoburn_destroy(struct isoburn **objpt, int flag)
    burn_source_free(o->iso_source);
  if(o->iso_data_source!=NULL)
    iso_data_source_unref(o->iso_data_source);
+ if(o->target_iso_head != NULL)
+   free(o->target_iso_head);
  free((char *) o);
  *objpt= NULL;
  return(1);
@@ -346,6 +355,37 @@ int isoburn_msgs_submit(struct isoburn *o, int error_code, char msg_text[],
 }
 
 
+/* TWINTREE: 
+   Check whether size of target_iso_head matches partition offset.
+   Eventually adjust size.
+*/
+int isoburn_adjust_target_iso_head(struct isoburn *o,
+                                   uint32_t offst, int flag)
+{
+ uint8_t *new_buf;
+ uint32_t new_size;
+
+ if(o->target_iso_head_size == Libisoburn_target_head_sizE + 2048 * offst)
+   return(1);
+ new_size= Libisoburn_target_head_sizE + 2048 * offst;
+ new_buf= calloc(1, new_size);
+ if(new_buf == NULL) {
+   isoburn_msgs_submit(o, 0x00060000,
+                       "Cannot re-allocate overwrite buffer", 0, "FATAL", 0);
+   return(-1);
+ }
+ memcpy(new_buf, o->target_iso_head,
+      o->target_iso_head_size < new_size ? o->target_iso_head_size : new_size);
+ free(o->target_iso_head);
+ o->target_iso_head= new_buf;
+ o->target_iso_head_size= new_size;
+ if(o->nwa == o->zero_nwa)
+   o->nwa= Libisoburn_overwriteable_starT + offst;
+ o->zero_nwa= Libisoburn_overwriteable_starT + offst;
+ return(1);
+}
+
+
 /* @param flag bit0= modifying rather than growing
                bit1= prepare for early release of input drive:
                      wait until input and then disable image data source
@@ -458,10 +498,17 @@ int isoburn_prepare_disc_aux(struct burn_drive *in_d, struct burn_drive *out_d,
                         opts->vol_expiration_time, opts->vol_effective_time,
                         opts->vol_uuid);
 
+ ret= isoburn_adjust_target_iso_head(out_o, opts->partition_offset, 0);
+ if(ret <= 0)
+   {ret= -1; goto ex;}
+ iso_write_opts_set_overwrite_buf(wopts,
+                                  nwa>0 ? out_o->target_iso_head : NULL);
+
  if(opts->no_emul_toc) {
    if(out_o->nwa == out_o->zero_nwa &&
-      out_o->zero_nwa == Libisoburn_overwriteable_starT &&
-      out_o->emulation_mode == 1) {
+      out_o->zero_nwa == Libisoburn_overwriteable_starT 
+                         + opts->partition_offset
+      && out_o->emulation_mode == 1) {
      out_o->nwa= 0;
      out_o->zero_nwa= 0;
      out_o->min_start_byte= 0;
@@ -477,41 +524,9 @@ int isoburn_prepare_disc_aux(struct burn_drive *in_d, struct burn_drive *out_d,
  }
  iso_write_opts_set_ms_block(wopts, nwa);
  iso_write_opts_set_appendable(wopts, !new_img);
- iso_write_opts_set_overwrite_buf(wopts,
-                                  nwa>0 ? out_o->target_iso_head : NULL);
-
- if (opts->partition_offset > 0) {
-
-   if (nwa > 0) {
-     /* >>> refuse because for now this works only for single session with
-            no_emul_toc
-        <<< to be removed when multi session stuff is fully ready 
-     */
-     isoburn_msgs_submit(in_o, 0x00060000,
-              "Programming error: non-zero NWA combined with partition offset",
-              0, "FATAL", 0);
-     {ret= -4; goto ex;}
-   }
-
-   iso_write_opts_set_part_offset(wopts, opts->partition_offset,
-                                  opts->partition_secs_per_head,
-                                  opts->partition_heads_per_cyl);
- }
-#ifdef Libisoburn_partition_offseT
-#if Libisoburn_partition_offseT >= 16
-
- else {
-   /* <<< For preliminary testing of emulated TOC and partition offset.
-          Problem is that only this macro can prepare the overwrite buffer
-          for partition offset yet. Emulated TOC does not work yet.
-   */
-   iso_write_opts_set_part_offset(wopts,
-                                  (uint32_t) Libisoburn_partition_offseT,
-                                  0, 0);
- }
-
-#endif
-#endif
+ iso_write_opts_set_part_offset(wopts, opts->partition_offset,
+                                opts->partition_secs_per_head,
+                                opts->partition_heads_per_cyl);
 
  ret = iso_image_create_burn_source(in_o->image, wopts, &wsrc);
  if (ret < 0) {

libisoburn/isoburn.h

@@ -36,20 +36,15 @@ int isoburn_toc_entry_new(struct isoburn_toc_entry **objpt,
 int isoburn_toc_entry_destroy(struct isoburn_toc_entry **o, int flag);
 
 
-/* >>> TWINTREE : provisory test of partition offset with emulated TOC.
-                  .target_iso_head must become dynamically allocated
-#define Libisoburn_partition_offseT 16
+/* Minimal size of target_iso_head which is to be written during
+   isoburn_activate_session().
+   TWINTREE:
+   Within this size there is everything that is needed for image access with
+   no partition offset. The actual target_iso_head buffer must be larger by
+   the evential partition offset.
 */
-
-
-/* Size of target_iso_head which is to be written during
-   isoburn_activate_session()
-*/
-#ifdef Libisoburn_partition_offseT
-#define Libisoburn_target_head_sizE (32*2048 +Libisoburn_partition_offseT*2048)
-#else
 #define Libisoburn_target_head_sizE (32*2048)
-#endif
+
 
 struct isoburn {
 
@@ -114,9 +109,14 @@ struct isoburn {
  int wrote_well;
 
  
- /* Buffered ISO head from media (should that become part of
-    ecma119_read_opts ?) */
- uint8_t target_iso_head[Libisoburn_target_head_sizE];
+ /* ISO head buffer to be filled by write run */
+ int target_iso_head_size;
+ uint8_t *target_iso_head;
+
+ /* The 2k offset which was read from a loaded image.
+ */
+ uint32_t loaded_partition_offset;
+ 
 
  /* Libisofs image context */
  IsoImage *image;
@@ -253,6 +253,13 @@ isoburn_data_source_new(struct burn_drive *d);
 int isoburn_data_source_shutdown(IsoDataSource *src, int flag);
 
 
+/** TWINTREE:
+    Check whether size of target_iso_head matches offset.
+    Eventually adjust size.
+*/
+int isoburn_adjust_target_iso_head(struct isoburn *o,
+                                   uint32_t offst, int flag);
+
 /**
  * Options for image reading.
    (Comments here may be outdated. API getter/setter function descriptions
@@ -576,6 +583,10 @@ struct isoburn_imgen_opts {
    written by random access before they were written sequentially.
    In this case, no copy of the session  1 header is maintained and no TOC
    will be possible. Thus writing begins sequentially at LBA 0.
+
+   TWINTREE:
+   This macro gives the minimal size of an image header. It has to be
+   enlarged by the eventual partition offset.
 */
 #define Libisoburn_overwriteable_starT \
                                    ((off_t) (Libisoburn_target_head_sizE/2048))

libisoburn/isofs_wrap.c

@@ -32,8 +32,8 @@
 
 #endif /* Xorriso_standalonE */
 
-#include "isoburn.h"
 #include "libisoburn.h"
+#include "isoburn.h"
 
 #define BP(a,b) [(b) - (a) + 1]
 
@@ -299,12 +299,111 @@ int isoburn_activate_session(struct burn_drive *drive)
    return 1;
  
  ret = burn_random_access_write(drive, (off_t) 0, (char*)o->target_iso_head, 
-                                Libisoburn_target_head_sizE, 1);
+                                o->target_iso_head_size, 1);
 
  return ret;
 }
 
 
+/** TWINTREE:
+    API @since 0.6.2
+*/
+int isoburn_get_img_partition_offset(struct burn_drive *drive,
+                                     uint32_t *block_offset_2k)
+{
+ int ret;
+ struct isoburn *o;
+
+ ret = isoburn_find_emulator(&o, drive, 0);
+ if(ret < 0 || o == NULL)
+   return -1;
+ *block_offset_2k= o->loaded_partition_offset;
+ if(o->loaded_partition_offset == 0)
+   return(0);
+ if(o->target_iso_head_size == (off_t) Libisoburn_target_head_sizE
+                           + (off_t) 2048 * (off_t) o->loaded_partition_offset)
+   return(1);
+ return(2);
+}
+
+
+/* TWINTREE:
+   Check for MBR signature and a first partition that starts at a 2k block 
+   and ends where the image ends.
+   If not too large or too small, accept its start as partition offset.
+*/
+static int isoburn_inspect_partition(struct isoburn *o, uint32_t img_size,
+                                     int flag)
+{
+ uint8_t *mbr, *part, buf[2048];
+ uint32_t offst, numsec;
+ struct ecma119_pri_vol_desc *pvm;
+ off_t data_count;
+ int ret;
+ char msg[160];
+ static int max_offst= 512 - 32;
+
+ mbr= o->target_iso_head;
+ part= mbr + 446;
+ if(mbr[510] != 0x55 || mbr[511] != 0xAA)
+   return(2); /* not an MBR */
+
+ /* Does the first partition entry look credible ? */
+ if(part[0] != 0x80 && part[0] != 0x00)
+   return(2); /* Invalid partition status */
+ if(part[1] == 0 && part[2] == 0 && part[3] == 0)
+   return(2); /* Zero C/H/S start address */
+
+ /* Does it match the normal ISO image ? */
+ offst= iso_read_lsb(part + 8, 4);
+ numsec= iso_read_lsb(part + 12, 4);
+ if(offst < 64)
+   return(2); /* Zero or unusably small partition start */
+ if((offst % 4) || (numsec % 4))
+   return(2); /* Not aligned to 2k */
+ if(numsec < 72)
+   return(2); /* No room for volume descriptors */
+ offst/= 4;
+ numsec/= 4;
+ if(offst + numsec != img_size)
+   return(2); /* Partition end does not match image end */
+
+ /* Is there a PVD at the partition start ? */
+ ret = burn_read_data(o->drive, (off_t) (offst + 16) * (off_t) 2048,
+                      (char*) buf, 2048, &data_count, 2);
+ if(ret <= 0)
+   return(2);
+ pvm = (struct ecma119_pri_vol_desc *) buf;
+ if (strncmp((char*) pvm->std_identifier, "CD001", 5) != 0)
+   return(2); /* not a PVD */
+ if (pvm->vol_desc_type[0] != 1 || pvm->vol_desc_version[0] != 1 
+     || pvm->file_structure_version[0] != 1 )
+   return(2); /* failed sanity check */
+
+ if(iso_read_lsb(pvm->vol_space_size, 4) + offst != img_size)
+   return(2); /* Image ends do not match */
+
+ /* Now it is credible. Not yet clear is whether it is acceptable. */
+ o->loaded_partition_offset= offst;
+
+ /* If the partition start is too large: Report but do not accept. */
+ if(offst > max_offst) { /* Not more than 1 MB of .target_iso_head */
+   sprintf(msg,
+      "Detected partition offset of %.f blocks. Maximum for load buffer is %d",
+      (double) offst, max_offst);
+   isoburn_msgs_submit(NULL, 0x00060000, msg, 0, "WARNING", 0);
+   return(3);
+ }
+
+ /* Accept partition start and adjust buffer size */
+ ret= isoburn_adjust_target_iso_head(o, offst, 0);
+ if(ret <= 0)
+   return(ret);
+
+ return(1);
+}
+
+
 /** Initialize the emulation of multi-session on random access media.
     The need for emulation is confirmed already.
     @param o A freshly created isoburn object. isoburn_create_data_source() was
@@ -337,8 +436,8 @@ int isoburn_start_emulation(struct isoburn *o, int flag)
  if (capacity > 0 || role == 2) {
    /* Might be a block device on a system where libburn cannot determine its
       size.  Try to read anyway. */
-   memset(o->target_iso_head, 0, Libisoburn_target_head_sizE);
-   to_read = Libisoburn_target_head_sizE;
+   to_read = o->target_iso_head_size;
+   memset(o->target_iso_head, 0, to_read);
    if(capacity > 0 && (off_t) capacity * (off_t) 2048 < to_read)
      to_read = (off_t) capacity * (off_t) 2048;
    ret = burn_read_data(drive, (off_t) 0, (char*)o->target_iso_head, 
@@ -370,7 +469,7 @@ int isoburn_start_emulation(struct isoburn *o, int flag)
 
  pvm = (struct ecma119_pri_vol_desc *)(o->target_iso_head + 16 * 2048);
 
- if (!strncmp((char*)pvm->std_identifier, "CD001", 5)) {
+ if (strncmp((char*)pvm->std_identifier, "CD001", 5) == 0) {
    off_t size;
 
    /* sanity check */
@@ -383,6 +482,9 @@ int isoburn_start_emulation(struct isoburn *o, int flag)
 
    /* ok, PVM found, set size */
    size = (off_t) iso_read_lsb(pvm->vol_space_size, 4);
+   ret= isoburn_inspect_partition(o, (uint32_t) size, 0);
+   if (ret <= 0)
+     return ret;
    size *= (off_t) 2048; /* block size in bytes */
    isoburn_set_start_byte(o, size, 0);
    o->fabricated_disc_status= BURN_DISC_APPENDABLE;
@@ -395,6 +497,7 @@ int isoburn_start_emulation(struct isoburn *o, int flag)
    /* treat any disc in an unknown format as full */
    o->fabricated_disc_status= BURN_DISC_FULL;
  }
+
  return 1;
 }
 

libisoburn/libisoburn.h

@@ -1361,6 +1361,24 @@ int isoburn_set_read_pacifier(struct burn_drive *drive,
                               int (*read_pacifier)(IsoImage*, IsoFileSource*),
                               void *app_handle);
 
+/** TWINTREE:
+    Inquire the partition offset of the loaded image. The first 512 bytes of
+    the image get examined whether they bear an MBR signature and a first
+    partition table entry which matches the size of the image. In this case
+    the start address is recorded as partition offset and internal buffers
+    get adjusted.
+    See also isoburn_igopt_set_part_offset().
+    @since 0.6.2
+    @param drive           The drive with the loaded image
+    @param block_offset_2k returns the recognized partition offset
+    @return <0 = error
+             0 = no partition offset recognized
+             1 = acceptable non-zero offset, buffers are adjusted
+             2 = offset is credible but not acceptable for buffer size
+*/ 
+int isoburn_get_img_partition_offset(struct burn_drive *drive,
+                                     uint32_t *block_offset_2k);
+
 
 /** Set the IsoImage to be used with a drive. This eventually releases
     the reference to the old IsoImage attached to the drive.
@@ -1659,3 +1677,7 @@ void isoburn_finish(void);
 int isoburn_needs_emulation(struct burn_drive *d);
  
 
+/* ---------------------------- Test area ----------------------------- */
+
+/* no tests active, currently */
+

xorriso/xorriso_timestamp.h

@@ -1 +1 @@
-#define Xorriso_timestamP "2010.09.06.103347"
+#define Xorriso_timestamP "2010.09.10.170925"