I have noticed that when a client issues a request from insecure port (involving an object from export that does not allow that) nfsd returns ERR_PERM. This does not seem to conform to the either NFS or RPC specification. First of all, NFS4 specification states that only CREATE, OPEN and SETATTR operations may return ERR_PERM, in situation when: "Not owner. The operation was not allowed because the caller is either not a privileged user (root) or not the owner of the target of the operation." Moreover, definition of ERR_ACCESS points out the difference between these two error codes. "Contrast this with NFS4ERR_PERM, which restricts itself to owner or privileged user permission failures." I believe that ERR_ACCESS is more suitable error code when access is denied due to insecure port, at least no client will get unexpected ERR_PERM. However, rejecting RPC request and setting rejection reason to AUTH_TOOWEAK seems to be the best solution. In appendix A RPC version 2 specification suggests that using privileged transport addresses may be a part of client authentication. "The authentication provided by this scheme can be considered legitimate only when applications using this scheme and the network can be secured externally, and privileged transport addresses are used for the communicating end-points (an example of this is the use of privileged TCP/UDP ports in UNIX systems -- note that not all systems enforce privileged transport address mechanisms)." Hence, AUTH_TOOWEAK would clearly state that access was denied due to authentication problem, use of insecure port in this case. IIRC this is the way nfsportmon behaves. Paweł Dziepak -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
