svc_dg_rendezvous: Bad message sa_family is 0xffff when receiving a NULL PROC over UDP

[oliviergaraud]

Tested with NFS Ganesha 6.3

I'm running the following command rpcinfo -u 127.0.0.1 nfs 4 to send a NULL RPC over UDP to ganesha.

The server shows the following log in a loop and the CPU consumption increase drastically.
ganesha.nfsd-144552[svc_34] rpc :TIRPC :CRIT :svc_dg_rendezvous: Bad message sa_family is 0xffff

If I revert #302 the problem is not visible anymore.

[oliviergaraud]

I made some progress on this:

close was not called if xprt->xp_flags didn't have SVC_XPRT_FLAG_CLOSE
https://github.com/nfs-ganesha/ntirpc/pull/302/files#diff-37072503703dc62cb86cabc70ea232df164ce3f724e4972f8779104ef5e49bf6L521

in svc_dg_rendezvous the CLOSE flag is not set for newxprt: https://github.com/nfs-ganesha/ntirpc/blob/next/src/svc_dg.c#L247 but the fd is shutdown in any case.

At this line https://github.com/nfs-ganesha/ntirpc/blob/next/ntirpc/rpc/svc.h#L565 we should probably have something like if ((flags & SVC_XPRT_FLAG_CLOSE) && xprt->xp_fd != RPC_ANYFD) {

[oliviergaraud]

Looks like fixed in #318