Better diagnostics for bad MARC records.

diff --git a/src/marcdisp.c b/src/marcdisp.c
index be233a7..c23b1b6 100644 (file)
--- a/src/marcdisp.c
+++ b/src/marcdisp.c
@@ -2,7 +2,7 @@
  * Copyright (C) 1995-2005, Index Data ApS
  * See the file LICENSE for details.
  *
- * $Id: marcdisp.c,v 1.18 2005-02-25 17:04:45 adam Exp $
+ * $Id: marcdisp.c,v 1.19 2005-03-06 21:27:09 adam Exp $
  */
 
 /**
@@ -86,6 +86,7 @@ int yaz_marc_decode_wrbuf (yaz_marc_t mt, const char *buf, int bsize, WRBUF wr)
     int record_length;
     int indicator_length;
     int identifier_length;
+    int end_of_directory;
     int base_address;
     int length_data_entry;
     int length_starting;
@@ -236,18 +237,37 @@ int yaz_marc_decode_wrbuf (yaz_marc_t mt, const char *buf, int bsize, WRBUF wr)
     /* first pass. determine length of directory & base of data */
     for (entry_p = 24; buf[entry_p] != ISO2709_FS; )
     {
-        entry_p += 3+length_data_entry+length_starting;
-        if (entry_p >= record_length)
+       /* length of directory entry */
+       int l = 3 + length_data_entry + length_starting;
+       if (entry_p + l >= record_length)
+       {
+           wrbuf_printf (wr, "<!-- Directory offset %d: end of record. "
+                           "Missing FS char -->\n", entry_p);
             return -1;
+       }
+        if (mt->debug)
+           wrbuf_printf (wr, "<!-- Directory offset %d: Tag %.3s -->\n",
+                           entry_p, buf+entry_p);
+       /* check for digits in length info */
+       while (--l >= 3)
+            if (!isdigit(*(const unsigned char *) (buf + entry_p+l)))
+               break;
+        if (l >= 3)
+       {
+           /* not all digits, so stop directory scan */
+           wrbuf_printf (wr, "<!-- Directory offset %d: Bad data for data "
+                           "length and/or length starting -->\n", entry_p);
+           break;
+       }
+        entry_p += 3 + length_data_entry + length_starting;
     }
+    end_of_directory = entry_p;
     if (base_address != entry_p+1)
     {
        if (produce_warnings)
-           wrbuf_printf (wr,"  <!-- Base address not at end of directory "
-                         "base=%d end=%d -->\n", base_address, entry_p+1);
+           wrbuf_printf (wr,"  <!-- Base address not at end of directory, "
+                         "base %d, end %d -->\n", base_address, entry_p+1);
     }
-    base_address = entry_p+1;
-
     if (mt->xml == YAZ_MARC_ISO2709)
     {
        WRBUF wr_head = wrbuf_alloc();
@@ -256,7 +276,7 @@ int yaz_marc_decode_wrbuf (yaz_marc_t mt, const char *buf, int bsize, WRBUF wr)
 
        int data_p = 0;
        /* second pass. create directory for ISO2709 output */
-       for (entry_p = 24; buf[entry_p] != ISO2709_FS; )
+       for (entry_p = 24; entry_p != end_of_directory; )
        {
            int data_length, data_offset, end_offset;
            int i, sz1, sz2;
@@ -303,7 +323,7 @@ int yaz_marc_decode_wrbuf (yaz_marc_t mt, const char *buf, int bsize, WRBUF wr)
        wrbuf_free(wr_tmp, 1);
     }
     /* third pass. create data output */
-    for (entry_p = 24; buf[entry_p] != ISO2709_FS; )
+    for (entry_p = 24; entry_p != end_of_directory; )
     {
         int data_length;
        int data_offset;
@@ -311,11 +331,10 @@ int yaz_marc_decode_wrbuf (yaz_marc_t mt, const char *buf, int bsize, WRBUF wr)
        int i, j;
        char tag[4];
         int identifier_flag = 0;
-       int entry_p0;
+       int entry_p0 = entry_p;
 
         memcpy (tag, buf+entry_p, 3);
        entry_p += 3;
-       entry_p0 = entry_p;
         tag[3] = '\0';
        data_length = atoi_n (buf+entry_p, length_data_entry);
        entry_p += length_data_entry;
@@ -324,20 +343,22 @@ int yaz_marc_decode_wrbuf (yaz_marc_t mt, const char *buf, int bsize, WRBUF wr)
        i = data_offset + base_address;
        end_offset = i+data_length-1;
 
-       if (data_length <= 0 || data_offset < 0 || end_offset >= record_length)
-       {
-           if (produce_warnings)
-               wrbuf_printf (wr,"  <!-- Bad data-offset=%d or "
-                                   "data-length=%d -->\n",
-                                         data_length, data_offset);
+       if (data_length <= 0 || data_offset < 0)
            break;
-       }
         
        if (mt->debug)
        {
-           wrbuf_printf(wr, "<!-- offset=%d data dlength=%d doffset=%d -->\n",
+           wrbuf_printf(wr, "<!-- Directory offset %d: data-length %d, "
+                           "data-offset %d -->\n",
                    entry_p0, data_length, data_offset);
        }
+       if (end_offset >= record_length)
+       {
+           wrbuf_printf (wr,"<!-- Directory offset %d: Data out of bounds "
+                           "%d >= %d -->\n",
+                                  entry_p0, end_offset, record_length);
+           break;
+       }
         
         if (memcmp (tag, "00", 2))
             identifier_flag = 1;  /* if not 00X assume subfields */
@@ -552,13 +573,10 @@ int yaz_marc_decode_buf (yaz_marc_t mt, const char *buf, int bsize,
                          char **result, int *rsize)
 {
     int r = yaz_marc_decode_wrbuf(mt, buf, bsize, mt->m_wr);
-    if (r > 0)
-    {
-        if (result)
-            *result = wrbuf_buf(mt->m_wr);
-        if (rsize)
-            *rsize = wrbuf_len(mt->m_wr);
-    }
+    if (result)
+        *result = wrbuf_buf(mt->m_wr);
+    if (rsize)
+        *rsize = wrbuf_len(mt->m_wr);
     return r;
 }
 

diff --git a/util/marcdump.c b/util/marcdump.c
index 34700cf..6dd79d1 100644 (file)
--- a/util/marcdump.c
+++ b/util/marcdump.c
@@ -2,7 +2,7 @@
  * Copyright (C) 1995-2005, Index Data ApS
  * See the file LICENSE for details.
  *
- * $Id: marcdump.c,v 1.27 2005-02-08 13:51:31 adam Exp $
+ * $Id: marcdump.c,v 1.28 2005-03-06 21:27:09 adam Exp $
  */
 
 #if HAVE_CONFIG_H
@@ -193,7 +193,7 @@ int main (int argc, char **argv)
                 while (1)
                 {
                     int len;
-                    char *result;
+                    char *result = 0;
                     int rlen;
                     
                     r = fread (buf, 1, 5, inf);
@@ -216,11 +216,10 @@ int main (int argc, char **argv)
                     if (r < len)
                         break;
                     r = yaz_marc_decode_buf (mt, buf, -1, &result, &rlen);
-                    if (r <= 0)
-                        break;
-                   fwrite (result, rlen, 1, stdout);
+                   if (result)
+                       fwrite (result, rlen, 1, stdout);
 #if HAVE_XML2
-                   if (libxml_dom_test)
+                   if (r > 0 && libxml_dom_test)
                    {
                        xmlDocPtr doc = xmlParseMemory(result, rlen);
                        if (!doc)
@@ -256,7 +255,7 @@ int main (int argc, char **argv)
                        }
                    }
 #endif
-                    if (cfile)
+                    if (r > 0 && cfile)
                     {
                         char *p = buf;
                         int i;