[rrd-developers] [PATCH] rrd_open: Make sure the data portion of the file is big enough

[kevin brintnall]

After we read the header, we can determine how large the entire file
should be.  Make sure that the file is large enough.
---
 src/rrd_open.c |   25 ++++++++++++++++++++++++-
 1 files changed, 24 insertions(+), 1 deletions(-)

diff --git a/src/rrd_open.c b/src/rrd_open.c
index 7a85aa8..2796506 100644
--- a/src/rrd_open.c
+++ b/src/rrd_open.c
@@ -72,7 +72,7 @@ rrd_file_t *rrd_open(
 #ifdef HAVE_MMAP
     ssize_t   _page_size = sysconf(_SC_PAGESIZE);
     int       mm_prot = PROT_READ, mm_flags = 0;
-    char     *data;
+    char     *data = MAP_FAILED;
 #endif
     off_t     offset = 0;
     struct stat statb;
@@ -271,11 +271,34 @@ rrd_file_t *rrd_open(
 
     rrd_file->header_len = offset;
     rrd_file->pos = offset;
+
+    {
+      unsigned long row_cnt = 0;
+      unsigned long i;
+
+      for (i=0; i<rrd->stat_head->rra_cnt; i++)
+        row_cnt += rrd->rra_def[i].row_cnt;
+
+      off_t correct_len = rrd_file->header_len +
+        sizeof(rrd_value_t) * row_cnt * rrd->stat_head->ds_cnt;
+
+      if (correct_len > rrd_file->file_len)
+      {
+        rrd_set_error("'%s' is too small (should be %ld bytes)",
+                      file_name, (long long) correct_len);
+        goto out_nullify_head;
+      }
+    }
+
   out_done:
     return (rrd_file);
   out_nullify_head:
     rrd->stat_head = NULL;
   out_close:
+#ifdef HAVE_MMAP
+    if (data != MAP_FAILED)
+      munmap(data, rrd_file->file_len);
+#endif
     close(rrd_file->fd);
   out_free:
     free(rrd_file);
-- 
1.6.0.2