New API call iso_file_make_md5() to equip old file nodes with MD5.

libisofs/ecma119.c

@@ -962,10 +962,10 @@ int checksum_prepare_nodes(Ecma119Image *target, IsoNode *node, int flag)
     IsoNode *pos;
     IsoFile *file;
     IsoImage *img;
-    int ret, i, no_md5 = 0;
+    int ret, i, no_md5 = 0, has_xinfo = 0;
     size_t value_length;
     unsigned int idx = 0;
-    char *value;
+    char *value= NULL, *direct_md5;
     void *xipt = NULL;
     static char *cx_names = "isofs.cx";
     static size_t cx_value_lengths[1] = {0};
@@ -978,10 +978,17 @@ int checksum_prepare_nodes(Ecma119Image *target, IsoNode *node, int flag)
         if (file->from_old_session && target->appendable) {
             /* Save MD5 data of files from old image which will not
                be copied and have an MD5 recorded in the old image. */
-            value= NULL;
-            ret = iso_node_lookup_attr(node, "isofs.cx", &value_length,
-                                       &value, 0);
-            if (ret == 1 && img->checksum_array == NULL) {
+            has_xinfo = iso_node_get_xinfo(node, checksum_md5_xinfo_func,
+                                           &xipt);
+            if (has_xinfo <= 0) {
+                ret = iso_node_lookup_attr(node, "isofs.cx", &value_length,
+                                           &value, 0);
+            }
+            if (has_xinfo > 0) {
+                /* xinfo MD5 overrides everything else unless data get copied
+                   and checksummed during that copying
+                 */;
+            } else if (ret == 1 && img->checksum_array == NULL) {
                 /* No checksum array loaded. Delete "isofs.cx" */
                 iso_node_set_attrs(node, (size_t) 1,
                               &cx_names, cx_value_lengths, &cx_valuept, 4 | 8);
@@ -993,7 +1000,7 @@ int checksum_prepare_nodes(Ecma119Image *target, IsoNode *node, int flag)
                     /* xipt is an int disguised as void pointer */
                     for (i = 0; i < 4; i++)
                         ((char *) &xipt)[i] = value[i];
-                    ret = iso_node_add_xinfo(node, checksum_xinfo_func,
+                    ret = iso_node_add_xinfo(node, checksum_cx_xinfo_func,
                                              xipt);
                     if (ret < 0)
                         return ret;
@@ -1002,8 +1009,10 @@ int checksum_prepare_nodes(Ecma119Image *target, IsoNode *node, int flag)
             } else {
                 no_md5 = 1;
             }
-            if (value != NULL)
+            if (value != NULL) {
                 free(value);
+                value= NULL;
+            }
         }
         /* Equip nodes with provisory isofs.cx numbers: 4 byte, all 0.
            Omit those from old image which will not be copied and have no MD5.

libisofs/filesrc.c

@@ -119,17 +119,21 @@ int iso_file_src_create(Ecma119Image *img, IsoFile *file, IsoFileSrc **src)
 #ifdef Libisofs_with_checksumS
 
     if ((img->md5_file_checksums & 1) &&
-         file->from_old_session && img->appendable) {
-        /* Omit MD5 indexing with old image nodes which have no MD5 */
-        ret = iso_node_get_xinfo((IsoNode *) file, checksum_xinfo_func, &xipt);
+        file->from_old_session && img->appendable) {
+        ret = iso_node_get_xinfo((IsoNode *) file, checksum_md5_xinfo_func,
+                                  &xipt);
         if (ret <= 0)
+            ret = iso_node_get_xinfo((IsoNode *) file, checksum_cx_xinfo_func,
+                                      &xipt);
+        if (ret <= 0)
+            /* Omit MD5 indexing with old image nodes which have no MD5 */
             no_md5 = 1;
     }
 
     if ((img->md5_file_checksums & 1) && !no_md5) {
         img->checksum_idx_counter++;
         if (img->checksum_idx_counter < 0x80000000) {
-            fsrc->checksum_index= img->checksum_idx_counter;
+            fsrc->checksum_index = img->checksum_idx_counter;
         } else {
             fsrc->checksum_index= 0;
             img->checksum_idx_counter= 0x80000000; /* keep from rolling over */
@@ -289,29 +293,9 @@ int filesrc_close(IsoFileSrc *file)
 static
 int filesrc_read(IsoFileSrc *file, char *buf, size_t count)
 {
-    size_t bytes = 0;
-
-    /* loop to ensure the full buffer is filled */
-    do {
-        ssize_t result;
-        result = iso_stream_read(file->stream, buf + bytes, count - bytes);
-        if (result < 0) {
-            /* fill buffer with 0s and return */
-            memset(buf + bytes, 0, count - bytes);
-            return result;
-        }
-        if (result == 0)
-            break;
-        bytes += result;
-    } while (bytes < count);
-
-    if (bytes < count) {
-        /* eof */
-        memset(buf + bytes, 0, count - bytes);
-        return 0;
-    } else {
-        return 1;
-    }
+    size_t got;
+
+    return iso_stream_read_buffer(file->stream, buf, count, &got);
 }
 
 #ifdef Libisofs_with_checksumS
@@ -319,46 +303,12 @@ int filesrc_read(IsoFileSrc *file, char *buf, size_t count)
 /* @return 1=ok, md5 is valid,
            0= not ok, go on,
           <0 fatal error, abort 
-*/
+*/  
+
 static
 int filesrc_make_md5(Ecma119Image *t, IsoFileSrc *file, char md5[16], int flag)
 {
-    int res, is_open = 0;
-    char buffer[BLOCK_SIZE];
-    void *ctx= NULL;
-    off_t file_size;
-    uint32_t b, nblocks;
-
-    if (! iso_stream_is_repeatable(file->stream))
-        return 0;
-    res = iso_md5_start(&ctx);
-    if (res < 0)
-        return res;
-    res = filesrc_open(file);
-    if (res < 0)
-        return 0;
-    is_open = 1;
-    file_size = iso_file_src_get_size(file);
-    nblocks = DIV_UP(file_size, BLOCK_SIZE);
-    for (b = 0; b < nblocks; ++b) {
-        res = filesrc_read(file, buffer, BLOCK_SIZE);
-        if (res < 0) {
-            res = 0;
-            goto ex;
-        }
-        if (file_size - b * BLOCK_SIZE > BLOCK_SIZE)
-            res = BLOCK_SIZE;
-        else
-            res = file_size - b * BLOCK_SIZE;
-        iso_md5_compute(ctx, buffer, res);
-    }
-    res = 1;
-ex:;
-    if (is_open)
-        filesrc_close(file);
-    if (ctx != NULL)
-        iso_md5_end(&ctx, md5);
-    return res;
+    return iso_stream_make_md5(file->stream, md5, 0);
 }
 
 #endif /* Libisofs_with_checksumS */

libisofs/libisofs.h

@@ -1424,10 +1424,13 @@ int iso_write_opts_set_sort_files(IsoWriteOpts *opts, int sort);
  * @param opts
  *      The option set to be manipulated.
  * @param session
- *      If bit0 set: compute session checksum
+ *      If bit0 set: Compute session checksum
  * @param files
- *      If bit0 set: compute a checksum for each single IsoFile object.
- *      If bit1 set: check content stability (only with bit0). I.e.  before
+ *      If bit0 set: Compute a checksum for each single IsoFile object which
+ *                   gets its data content written into the session. Copy
+ *                   checksums from files which keep their data in older
+ *                   sessions.
+ *      If bit1 set: Check content stability (only with bit0). I.e.  before
  *                   writing the file content into to image stream, read it
  *                   once and compute a MD5. Do a second reading for writing
  *                   into the image stream. Afterwards compare both MD5 and
@@ -5055,6 +5058,28 @@ int iso_image_get_session_md5(IsoImage *image, uint32_t *start_lba,
  */
 int iso_file_get_md5(IsoImage *image, IsoFile *file, char md5[16], int flag);
 
+/**
+ * Read the content of an IsoFile object, compute its MD5 and attach it to
+ * the IsoFile. It can then be inquired by iso_file_get_md5() and will get
+ * written into the next session if this is enabled at write time and if the
+ * image write process does not compute an MD5 from content which it copies.
+ * So this call can be used to equip nodes from the old image with checksums
+ * or to make available checksums of newly added files before the session gets
+ * written.
+ * @param file
+ *      The file object to read data from and to which to attach the checksum.
+ *      If the file is from the imported image, then its most original stream
+ *      will be checksummed. Else the eventual filter streams will get into
+ *      effect.
+ * @param flag
+ *      Bitfield for control purposes. Unused yet. Submit 0.
+ * @return
+ *      1= ok, MD5 is computed and attached , <0 indicates error
+ *
+ * @since 0.6.22
+ */
+int iso_file_make_md5(IsoFile *file, int flag);
+
 /**
  * Check a data block whether it is a libisofs session checksum tag and
  * eventually obtain its recorded parameters. These tags get written after

libisofs/md5.c

@@ -406,13 +406,25 @@ int iso_md5_match(char first_md5[16], char second_md5[16])
  * data is supposed to be a 4 byte integer, bit 31 shall be 0,
  * value 0 of this integer means that it is not a valid index.
  */
-int checksum_xinfo_func(void *data, int flag)
+int checksum_cx_xinfo_func(void *data, int flag)
 {
     /* data is an int disguised as pointer. It does not point to memory. */
     return 1;
 }
 
 
+/* Function to identify and manage md5 sums of unspecified providence stored
+ * directly in this xinfo.
+ */
+int checksum_md5_xinfo_func(void *data, int flag)
+{
+    if (data == NULL)
+        return 1;
+    free(data);
+    return 1;
+}
+
+
 /* ----------------------------------------------------------------------- */
 
 /* MD5 checksum image writer */
@@ -432,25 +444,43 @@ int checksum_copy_old_nodes(Ecma119Image *target, IsoNode *node, int flag)
     int ret, i;
     size_t value_length;
     unsigned int idx = 0, old_idx = 0;
-    char *value = NULL;
+    char *value = NULL, *md5_pt = NULL;
     void *xipt;
 
     img = target->image;
-    if (img->checksum_array == NULL || target->checksum_buffer == NULL)
+    if (target->checksum_buffer == NULL)
         return 0;
 
     if (node->type == LIBISO_FILE) {
         file = (IsoFile *) node;
         if (file->from_old_session && target->appendable) {
-            ret = iso_node_get_xinfo(node, checksum_xinfo_func, &xipt);
-            if (ret <= 0)
-                return ret;
-            /* xipt is an int disguised as void pointer */
-            old_idx = 0;
-            for (i = 0; i < 4; i++)
-                old_idx = (old_idx << 8) | ((unsigned char *) &xipt)[i];
+            /* Look for checksums at various places */
+
+            /* Try checksum directly stored with node */
+            if (md5_pt == NULL) {
+                ret = iso_node_get_xinfo(node, checksum_md5_xinfo_func, &xipt);
+                if (ret < 0)
+                    return ret;
+                if (ret == 1)
+                    md5_pt = (char *) xipt;
+            }
+
+            /* Try checksum index to image checksum buffer */
+            if (md5_pt == NULL && img->checksum_array != NULL) {
+                ret = iso_node_get_xinfo(node, checksum_cx_xinfo_func, &xipt);
+                if (ret <= 0)
+                    return ret;
+                /* xipt is an int disguised as void pointer */
+                old_idx = 0;
+                for (i = 0; i < 4; i++)
+                    old_idx = (old_idx << 8) | ((unsigned char *) &xipt)[i];
+    
+                if (old_idx == 0 || old_idx > img->checksum_idx_count - 1)
+                    return 0;
+                md5_pt = img->checksum_array + 16 * old_idx;
+            }
 
-            if (old_idx == 0 || old_idx > img->checksum_idx_count - 1)
+            if (md5_pt == NULL)
                 return 0;
 
             ret = iso_node_lookup_attr(node, "isofs.cx", &value_length,
@@ -459,12 +489,13 @@ int checksum_copy_old_nodes(Ecma119Image *target, IsoNode *node, int flag)
                 for (i = 0; i < 4; i++)
                     idx = (idx << 8) | ((unsigned char *) value)[i];
                 if (idx > 0 && idx <= target->checksum_idx_counter) {
-                    memcpy(target->checksum_buffer + 16 * idx,
-                           img->checksum_array + 16 * old_idx, 16);
+                    memcpy(target->checksum_buffer + 16 * idx, md5_pt, 16);
                 }
             }
             if (value != NULL)
                 free(value);
+            iso_node_remove_xinfo(node, checksum_md5_xinfo_func);
+            iso_node_remove_xinfo(node, checksum_cx_xinfo_func);
         }
     } else if (node->type == LIBISO_DIR) {
         for (pos = ((IsoDir *) node)->children; pos != NULL; pos = pos->next) {

libisofs/md5.h

@@ -19,13 +19,6 @@
 int checksum_writer_create(Ecma119Image *target);
 
 
-/* Function to identify and manage md5sum indice of the old image.
- * data is supposed to be a 4 byte integer, bit 31 shall be 0,
- * value 0 of this integer means that it is not a valid index.
- */
-int checksum_xinfo_func(void *data, int flag);
-
-
 /* Write stream detectable checksum tag to extra block.
  * All tag ranges start at the beginning of the System Area (i.e. t->ms_block)
  * and stem from the same MD5 computation context. Tag types 2 and 3 are

libisofs/node.c

@@ -2678,6 +2678,14 @@ int iso_file_get_md5(IsoImage *image, IsoFile *file, char md5[16], int flag)
     size_t value_len;
     char *value = NULL;
     uint32_t idx = 0;
+    void *xipt;
+
+    /* xinfo MD5 overrides everything else */
+    ret = iso_node_get_xinfo((IsoNode *) file, checksum_md5_xinfo_func, &xipt);
+    if (ret == 1) {
+        memcpy(md5, (char *) xipt, 16);
+        return 1;
+    }
 
     if (image->checksum_array == NULL)
         return 0;
@@ -2714,3 +2722,40 @@ ex:;
 
 }
 
+
+/* API */
+int iso_file_make_md5(IsoFile *file, int flag)
+{
+
+#ifdef Libisofs_with_checksumS
+    int ret, dig = 0;
+    char *md5 = NULL;
+
+    if (file->from_old_session)
+        dig = 1;
+    md5= calloc(16, 1);
+    ret = iso_stream_make_md5(file->stream, md5, dig);
+    if (ret < 0)
+        goto ex;
+    iso_node_remove_xinfo((IsoNode *) file, checksum_md5_xinfo_func);
+    ret = iso_node_add_xinfo((IsoNode *) file, checksum_md5_xinfo_func, md5);
+    if (ret == 0)
+        ret = ISO_ERROR; /* should not happen after iso_node_remove_xinfo() */
+    if (ret < 0) {
+        free(md5);
+        goto ex;
+    }
+    ret = 1;
+ex:;
+    return ret;
+
+#else
+
+    return ISO_ERROR;
+
+#endif /* ! Libisofs_with_checksumS */
+
+}
+
+
+

libisofs/stream.c

@@ -830,3 +830,96 @@ int iso_stream_cmp_ino(IsoStream *s1, IsoStream *s2, int flag)
 
     return 0;
 }
+
+
+/**
+ * @return
+ *     1 ok, 0 EOF, < 0 error
+ */    
+int iso_stream_read_buffer(IsoStream *stream, char *buf, size_t count,
+                           size_t *got)
+{
+    ssize_t result;
+
+    *got = 0;
+    do {
+        result = iso_stream_read(stream, buf + *got, count - *got);
+        if (result < 0) {
+            memset(buf + *got, 0, count - *got);
+            return result;
+        }
+        if (result == 0)
+            break;
+        *got += result;
+    } while (*got < count);
+
+    if (*got < count) {
+        /* eof */
+        memset(buf + *got, 0, count - *got);
+        return 0;
+    }
+    return 1;
+}
+
+#ifdef Libisofs_with_checksumS
+
+
+/* @param flag bit0= dig out most original stream (e.g. because from old image)
+   @return 1=ok, md5 is valid,
+           0= not ok, 
+          <0 fatal error, abort 
+*/  
+int iso_stream_make_md5(IsoStream *stream, char md5[16], int flag)
+{
+    int res, is_open = 0;
+    char buffer[2048];
+    void *ctx= NULL;
+    off_t file_size;
+    uint32_t b, nblocks;
+    size_t got_bytes;
+    IsoStream *input_stream;
+
+    if (flag & 1) {
+        while(1) {
+           input_stream = iso_stream_get_input_stream(stream, 0);
+           if (input_stream == NULL)
+        break;
+           stream = input_stream;
+        }
+    }
+
+    if (! iso_stream_is_repeatable(stream))
+        return 0;
+    res = iso_md5_start(&ctx);
+    if (res < 0)
+        return res;
+    res = iso_stream_open(stream);
+    if (res < 0)
+        return 0;
+    is_open = 1;
+    file_size = iso_stream_get_size(stream);
+    nblocks = DIV_UP(file_size, 2048);
+    for (b = 0; b < nblocks; ++b) {
+        res = iso_stream_read_buffer(stream, buffer, 2048, &got_bytes);
+        if (res < 0) {
+            res = 0;
+            goto ex;
+        }
+        /* Do not use got_bytes to stay closer to IsoFileSrc processing */
+        if (file_size - b * 2048 > 2048)
+            res = 2048;
+        else
+            res = file_size - b * 2048;
+        iso_md5_compute(ctx, buffer, res);
+    }
+    res = 1;
+ex:;
+    if (is_open)
+        iso_stream_close(stream);
+    if (ctx != NULL)
+        iso_md5_end(&ctx, md5);
+    return res;
+}
+
+#endif /* Libisofs_with_checksumS */
+

libisofs/stream.h

@@ -83,4 +83,24 @@ int iso_stream_get_src_zf(IsoStream *stream, int *header_size_div4,
 int iso_stream_set_image_ino(IsoStream *stream, ino_t ino, int flag);
 
 
+/**
+ * Read the full required amount of data unless error or EOF occurs.
+ * Fill missing bytes by 0s.
+ * @param count   Required amount
+ * @param got     Returns number of actually read bytes
+ * @return
+ *     1 no problem encountered, 0 EOF encountered, < 0 error
+ */
+int iso_stream_read_buffer(IsoStream *stream, char *buf, size_t count,
+                           size_t *got);
+
+/**
+ * @return 1=ok, md5 is valid,
+ *        0= not ok
+ *       <0 fatal error, abort 
+ */
+int iso_stream_make_md5(IsoStream *stream, char md5[16], int flag);
+
+
+
 #endif /*STREAM_H_*/

libisofs/util.h

@@ -482,4 +482,26 @@ int iso_util_eval_md5_tag(char *block, int desired, uint32_t lba,
 int iso_util_tag_magic(int tag_type, char **tag_magic, int *len, int flag);
 
 
+/* ------------------------------------------------------------------------- */
+
+/* In md5.h these function prototypes would be neighbors of (Ecma119Image *)
+   which needs inclusion of ecma119.h and more. So, being generic, they ended
+   up here.
+*/
+
+/* Function to identify and manage md5sum indice of the old image.
+ * data is supposed to be a 4 byte integer, bit 31 shall be 0,
+ * value 0 of this integer means that it is not a valid index.
+ */
+int checksum_cx_xinfo_func(void *data, int flag);
+
+/* Function to identify and manage md5 sums of unspecified providence stored
+ * directly in this xinfo. This is supposed to override any other recorded
+ * MD5 of the node unless data get copied and checksummed during that copying.
+ */
+int checksum_md5_xinfo_func(void *data, int flag);
+
+/* ------------------------------------------------------------------------- */
+
+
 #endif /*LIBISO_UTIL_H_*/