RFC3530 states:
Where an NFS version 4 implementation supports operation over the IP
network protocol, the supported transports between NFS and IP MUST be
among the IETF-approved congestion control transport protocols, which
include TCP and SCTP
This patch adds a wrapper for nfsd_dispatch that checks to see whether
the call came in via UDP, and then rejects it with a PROG_MISMATCH RPC
error. This replaces the earlier one I proposed -- it should mean no
extra overhead for NFSv2/3.
It also has the NFS server skip rpcbind registration for NFSv4 over UDP.
Reported-by: Sachin Prabhu <sprabhu@xxxxxxxxxx>
Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
fs/nfsd/nfs4proc.c | 3 ++-
fs/nfsd/nfsd.h | 1 +
fs/nfsd/nfssvc.c | 13 +++++++++++++
3 files changed, 16 insertions(+), 1 deletions(-)
diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index 59ec449..afbd03c 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -1363,8 +1363,9 @@ struct svc_version nfsd_version4 = {
.vs_vers = 4,
.vs_nproc = 2,
.vs_proc = nfsd_procedures4,
- .vs_dispatch = nfsd_dispatch,
+ .vs_dispatch = nfsd4_dispatch,
.vs_xdrsize = NFS4_SVC_XDRSIZE,
+ .vs_hidden_udp = true,
};
/*
diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h
index 7237776..f36e07c 100644
--- a/fs/nfsd/nfsd.h
+++ b/fs/nfsd/nfsd.h
@@ -41,6 +41,7 @@ extern const struct seq_operations nfs_exports_op;
*/
int nfsd_svc(unsigned short port, int nrservs);
int nfsd_dispatch(struct svc_rqst *rqstp, __be32 *statp);
+int nfsd4_dispatch(struct svc_rqst *rqstp, __be32 *statp);
int nfsd_nrthreads(void);
int nfsd_nrpools(void);
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index 6b59d32..0a04472 100644
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -595,6 +595,19 @@ nfsd_dispatch(struct svc_rqst *rqstp, __be32 *statp)
return 1;
}
+int
+nfsd4_dispatch(struct svc_rqst *rqstp, __be32 *statp)
+{
+ /* Reject any NFSv4 request over UDP. Don't bother caching it. */
+ if (rqstp->rq_prot == IPPROTO_UDP) {
+ dprintk("%s: rejecting vers 4 request over UDP\n", __func__);
+ *statp = rpc_prog_mismatch;
+ return 1;
+ }
+
+ return nfsd_dispatch(rqstp, statp);
+}
+
int nfsd_pool_stats_open(struct inode *inode, struct file *file)
{
int ret;
--
1.5.5.6
--
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