header = ntohl (header);
rstrm->last_frag = ((header & LAST_FRAG) == 0) ? FALSE : TRUE;
/*
- * Sanity check. Try not to accept wildly incorrect
- * record sizes. Unfortunately, the only record size
- * we can positively identify as being 'wildly incorrect'
- * is zero. Ridiculously large record sizes may look wrong,
- * but we don't have any way to be certain that they aren't
- * what the client actually intended to send us.
+ * Sanity check. Try not to accept wildly incorrect fragment
+ * sizes. Unfortunately, only a size of zero can be identified as
+ * 'wildely incorrect', and this only, if it is not the last
+ * fragment of a message. Ridiculously large fragment sizes may look
+ * wrong, but we don't have any way to be certain that they aren't
+ * what the client actually intended to send us. Many existing RPC
+ * implementations may sent a fragment of size zero as the last
+ * fragment of a message.
*/
- if ((header & (~LAST_FRAG)) == 0)
+ if (header == 0)
return FALSE;
rstrm->fbtbc = header & ~LAST_FRAG;
return TRUE;