1 files changed, 30 insertions, 10 deletions

diff --git a/src/main/extractor_datasource.c b/src/main/extractor_datasource.c
index 4efe3b2..e2f151a 100644
--- a/src/main/extractor_datasource.c
+++ b/src/main/extractor_datasource.c
@@ -364,7 +364,10 @@ bfds_seek (struct BufferedFileDataSource *bfds,
         }
       if (pos > bfds->fsize)
         {
-          LOG ("Invalid seek operation\n");
+          LOG ("Invalid seek operation (%lld > %llu) %d\n",
+               (long long) pos,
+               (unsigned long long) bfds->fsize,
+               SEEK_SET == whence);
           return -1;
         }
       if ( (NULL == bfds->buffer) ||
@@ -538,8 +541,7 @@ cfs_init_decompressor_zlib (struct CompressedFileSource *cfs,
   if (sizeof (hdata) > bfds_read (cfs->bfds, hdata, sizeof (hdata)))
     return -1;
   if (0 != (hdata[3] & 0x4)) /* FEXTRA  set */
-    gzip_header_length += 2 + (unsigned) (hdata[10] & 0xff) +
-      (((unsigned) (hdata[11] & 0xff)) * 256);
+    gzip_header_length += 2 + (hdata[10] & 0xff) + ((hdata[11] & 0xff) * 256);
 
   if (0 != (hdata[3] & 0x8)) 
     {
@@ -550,18 +552,27 @@ cfs_init_decompressor_zlib (struct CompressedFileSource *cfs,
       ssize_t buf_bytes;
       
       if (gzip_header_length > bfds_seek (cfs->bfds, gzip_header_length, SEEK_SET))
-        return -1;
+        {
+          LOG ("Corrupt gzip, failed to seek to end of header\n");
+          return -1;
+        }
       buf_bytes = bfds_read (cfs->bfds, fname, sizeof (fname));
       if (buf_bytes <= 0)
-        return -1;
+        {
+          LOG ("Corrupt gzip, failed to read filename\n");        
+          return -1;
+        }
       if (NULL == (cptr = memchr (fname, 0, buf_bytes)))
-        return -1;
+        {
+          LOG ("Corrupt gzip, failed to read filename terminator\n");
+          return -1;
+        }
       len = cptr - fname;
       if (0 != proc (proc_cls, "<zlib>", EXTRACTOR_METATYPE_FILENAME,
                      EXTRACTOR_METAFORMAT_C_STRING, "text/plain",
                      fname,
                      len))
-        return 0; /* done */
+        return 0; /* done */    
       gzip_header_length += len + 1;
     }
   
@@ -574,12 +585,21 @@ cfs_init_decompressor_zlib (struct CompressedFileSource *cfs,
       size_t len;
       
       if (gzip_header_length > bfds_seek (cfs->bfds, gzip_header_length, SEEK_SET))
-        return -1;
+        {
+          LOG ("Corrupt gzip, failed to seek to end of header\n");
+          return -1;
+        }
       buf_bytes = bfds_read (cfs->bfds, fcomment, sizeof (fcomment));
       if (buf_bytes <= 0)
-        return -1;
+        {
+          LOG ("Corrupt gzip, failed to read comment\n");         
+          return -1;
+        }
       if (NULL == (cptr = memchr (fcomment, 0, buf_bytes)))
-        return -1;
+        {
+          LOG ("Corrupt gzip, failed to read comment terminator\n");
+          return -1;
+        }
       len = cptr - fcomment;
       if (0 != proc (proc_cls, "<zlib>", EXTRACTOR_METATYPE_COMMENT,
                      EXTRACTOR_METAFORMAT_C_STRING, "text/plain",