Follow-up fixes to fd5cf245ea.

These address https://puszcza.gnu.org.ua/bugs/?503

* src/gdbmdefs.h (gdbm_avail_block_valid_p): Remove.
* src/gdbmopen.c (gdbm_avail_block_validate): Use inline conditional
instead of gdbm_avail_block_valid_p.
(gdbm_fd_open): Revert to reading master avail_block in two passes (as
was before fd5cf245ea).
(validate_header): Add back master avail block consistency check.
* src/gdbmtool.c (_gdbm_avail_list_size): Use _gdbm_avail_block_read.
* src/recover.c (_gdbm_finish_transfer): Reset dbf->file_size.

4 files changed, 32 insertions, 31 deletions

diff --git a/src/gdbmdefs.h b/src/gdbmdefs.h
index bfa05c6..c3ff353 100644
--- a/src/gdbmdefs.h
+++ b/src/gdbmdefs.h
@@ -66,13 +66,6 @@ typedef struct
   avail_elem av_table[1]; /* The table.  Make it look like an array.  */
 } avail_block;
 
-/* Return true if avail_block is valid */
-static int inline
-gdbm_avail_block_valid_p (avail_block const *av)
-{
-  return (av->size > 1 && av->count >= 0 && av->count <= av->size);
-}
-
 /* Return true if both AV and the size of AV->av_table are valid.
    See comment to this function in gdbmopen.c */
 extern int gdbm_avail_table_valid_p (GDBM_FILE dbf, avail_elem *av, int count);
diff --git a/src/gdbmopen.c b/src/gdbmopen.c
index c769643..97654c7 100644
--- a/src/gdbmopen.c
+++ b/src/gdbmopen.c
@@ -108,8 +108,9 @@ gdbm_avail_table_valid_p (GDBM_FILE dbf, avail_elem *av, int count)
 int
 gdbm_avail_block_validate (GDBM_FILE dbf, avail_block *avblk, size_t size)
 {
-  if (!(((size - sizeof (avail_block)) / sizeof (avail_elem) + 1) >= avblk->count
-	&& gdbm_avail_block_valid_p (avblk)
+  if (!(size > sizeof (avail_block)
+	&& (avblk->size > 1 && avblk->count >= 0 && avblk->count <= avblk->size)
+	&& ((size - sizeof (avail_block)) / sizeof (avail_elem) + 1) >= avblk->count
 	&& gdbm_avail_table_valid_p (dbf, avblk->av_table, avblk->count)))
     {
       GDBM_SET_ERRNO (dbf, GDBM_BAD_AVAIL, TRUE);
@@ -198,17 +199,15 @@ validate_header (gdbm_file_header const *hdr, struct stat const *st)
   if (hdr->bucket_elems != bucket_element_count (hdr->bucket_size))
     return GDBM_BAD_HEADER;
 
+  if (((hdr->block_size - sizeof (gdbm_file_header)) / sizeof(avail_elem) + 1)
+      != hdr->avail.size)
+    return GDBM_BAD_HEADER;
+
   return result;
 }
 
-/*
- * GDBM file header is read in two chunks: first, all fields up to avail,
- * then the avail block.  PARTIAL_HEADER_SIZE is the size of the first
- * chunk, and HEADER_AVAIL_SIZE(dbf) gives the size of the second one.
- */
-#define PARTIAL_HEADER_SIZE (offsetof (gdbm_file_header, avail))
 #define HEADER_AVAIL_SIZE(dbf) \
-  ((dbf)->header->block_size - PARTIAL_HEADER_SIZE)
+  ((dbf)->header->block_size - offsetof (gdbm_file_header, avail))
 
 int
 _gdbm_validate_header (GDBM_FILE dbf)
@@ -541,7 +540,7 @@ gdbm_fd_open (int fd, const char *file_name, int block_size,
       int rc;
       
       /* Read the partial file header. */
-      if (_gdbm_full_read (dbf, &partial_header, PARTIAL_HEADER_SIZE))
+      if (_gdbm_full_read (dbf, &partial_header, sizeof (partial_header)))
 	{
 	  GDBM_DEBUG (GDBM_DEBUG_ERR|GDBM_DEBUG_OPEN,
 		      "%s: error reading partial header: %s",
@@ -578,9 +577,9 @@ gdbm_fd_open (int fd, const char *file_name, int block_size,
 	  return NULL;
 	}
       
-      memcpy (dbf->header, &partial_header, PARTIAL_HEADER_SIZE);
-      if (_gdbm_avail_block_read (dbf, &dbf->header->avail,
-				  HEADER_AVAIL_SIZE (dbf)))
+      memcpy (dbf->header, &partial_header, sizeof (partial_header));
+      if (_gdbm_full_read (dbf, &dbf->header->avail.av_table[1],
+			   dbf->header->block_size - sizeof (gdbm_file_header)))
 	{
 	  if (!(flags & GDBM_CLOERROR))
 	    dbf->desc = -1;
@@ -588,6 +587,15 @@ gdbm_fd_open (int fd, const char *file_name, int block_size,
 	  return NULL;
 	}
 
+      if (gdbm_avail_block_validate (dbf, &dbf->header->avail,
+				     HEADER_AVAIL_SIZE (dbf)))
+	{
+	  if (!(flags & GDBM_CLOERROR))
+	    dbf->desc = -1;
+	  SAVE_ERRNO (gdbm_close (dbf));
+	  return NULL;
+	}
+      
       /* Allocate space for the hash table directory.  */
       dbf->dir = malloc (dbf->header->dir_size);
       if (dbf->dir == NULL)
diff --git a/src/gdbmtool.c b/src/gdbmtool.c
index 1d6b8dd..0293647 100644
--- a/src/gdbmtool.c
+++ b/src/gdbmtool.c
@@ -240,19 +240,17 @@ _gdbm_avail_list_size (GDBM_FILE dbf, size_t min_size)
 	  terror ("lseek: %s", strerror (errno));
 	  break;
 	}
-      
-      if (_gdbm_full_read (dbf, av_stk, size))
+
+      if (_gdbm_avail_block_read (dbf, av_stk, size))
 	{
 	  terror ("read: %s", gdbm_db_strerror (dbf));
 	  break;
 	}
 
-      if (gdbm_avail_block_valid_p (av_stk))
-	{
-	  lines += av_stk->count;
-	  if (lines > min_size)
-	    break;
-	}
+      lines += av_stk->count;
+      if (lines > min_size)
+	break;
+
       temp = av_stk->next_block;
     }
   free (av_stk);
@@ -276,7 +274,7 @@ void
 _gdbm_print_avail_list (FILE *fp, GDBM_FILE dbf)
 {
   int             temp;
-  int             size;
+  size_t          size;
   avail_block    *av_stk;
   
   /* Print the the header avail block.  */
@@ -286,8 +284,8 @@ _gdbm_print_avail_list (FILE *fp, GDBM_FILE dbf)
 
   /* Initialize the variables for a pass throught the avail stack. */
   temp = dbf->header->avail.next_block;
-  size = ((dbf->header->avail.size - 1) * sizeof (avail_elem))
-	  + sizeof (avail_block);
+  size = (((size_t)dbf->header->avail.size - 1) * sizeof (avail_elem))
+          + sizeof (avail_block);
   av_stk = emalloc (size);
 
   /* Print the stack. */
diff --git a/src/recover.c b/src/recover.c
index 26a6414..b4b577c 100644
--- a/src/recover.c
+++ b/src/recover.c
@@ -164,6 +164,8 @@ _gdbm_finish_transfer (GDBM_FILE dbf, GDBM_FILE new_dbf,
   dbf->directory_changed = new_dbf->directory_changed;
   dbf->bucket_changed    = new_dbf->bucket_changed;
   dbf->second_changed    = new_dbf->second_changed;
+
+  dbf->file_size = -1;
   
   free (new_dbf->name);
   free (new_dbf);