On Thu, 2018-06-28 at 09:45 -0400, Chuck Lever wrote:
> We have a report that some commercial NFS file servers still do not
> support rpcbind v4 correctly. They return RPC_CANTDECODEARGS instead
> of RPC_PROGVERSMISMATCH, so our rpcbind client now errors out
> immediately instead of trying a lower rpcbind version.
>
> To address this, convert the "if () else if () else if ()" to a
> switch statement to make it straightforward to add new status codes
> to the error processing logic. Then, add a case for
> RPC_CANTDECODEARGS.
>
> Reported-by: Yuan-Yao Sung <yysung@xxxxxxxxxxxxxx>
> Fixes: 5e7b57bc20bd ("rpcinfo: change order of version to be ... ")
> Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
> Tested-by: Yuan-Yao Sung <yysung@xxxxxxxxxxxxxx>
> ---
> src/rpcb_clnt.c | 13 +++++++++----
> 1 file changed, 9 insertions(+), 4 deletions(-)
>
> diff --git a/src/rpcb_clnt.c b/src/rpcb_clnt.c
> index 4b44364..d6fefd0 100644
> --- a/src/rpcb_clnt.c
> +++ b/src/rpcb_clnt.c
> @@ -846,6 +846,7 @@ __rpcb_findaddr_timed(program, version, nconf,
> host, clpp, tp)
> struct netbuf *address = NULL;
> rpcvers_t start_vers = RPCBVERS4;
> struct netbuf servaddr;
> + struct rpc_err rpcerr;
>
> /* parameter checking */
> if (nconf == NULL) {
> @@ -902,7 +903,8 @@ __rpcb_findaddr_timed(program, version, nconf,
> host, clpp, tp)
> clnt_st = CLNT_CALL(client,
> (rpcproc_t)RPCBPROC_GETADDR,
> (xdrproc_t) xdr_rpcb, (char *)(void *)&parms,
> (xdrproc_t) xdr_wrapstring, (char *)(void *)
> &ua, *tp);
> - if (clnt_st == RPC_SUCCESS) {
> + switch (clnt_st) {
> + case RPC_SUCCESS:
> if ((ua == NULL) || (ua[0] == 0)) {
> /* address unknown */
> rpc_createerr.cf_stat =
> RPC_PROGNOTREGISTERED;
> @@ -924,12 +926,15 @@ __rpcb_findaddr_timed(program, version, nconf,
> host, clpp, tp)
> (char *)(void *)&servaddr);
> __rpc_fixup_addr(address, &servaddr);
> goto done;
> - } else if (clnt_st == RPC_PROGVERSMISMATCH) {
> - struct rpc_err rpcerr;
> + case RPC_PROGVERSMISMATCH:
> clnt_geterr(client, &rpcerr);
> if (rpcerr.re_vers.low > RPCBVERS4)
> goto error; /* a new version, can't
> handle */
> - } else if (clnt_st != RPC_PROGUNAVAIL) {
> + /* Try the next lower version */
> + case RPC_PROGUNAVAIL:
> + case RPC_CANTDECODEARGS:
> + break;
> + default:
> /* Cant handle this error */
> rpc_createerr.cf_stat = clnt_st;
> clnt_geterr(client,
> &rpc_createerr.cf_error);
>
> --
Interesting... Do these servers return any other non-sanctioned errors?
I can't find RPC_CANTDECODEARGS described in any of the official RFCs
pertaining to RPC, NFS or the RPCBIND protocol. It appears to be listed
among the private error codes in the libtirpc header files, and in some
java libraries, but googling around appeared to indicate that those
codes are intended for internal library signalling only, and should not
appear on the wire:
https://people.eecs.berkeley.edu/~jonah/javadoc/org/acplt/oncrpc/OncRp
cException.html
--
Trond Myklebust
Linux NFS client maintainer, Hammerspace
trond.myklebust@xxxxxxxxxxxxxxx
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