Merge tag 'nfsd-4.11' of git://linux-nfs.org/~bfields/linux

[sfrench/cifs-2.6.git] / net / sunrpc / svc.c

diff --git a/net/sunrpc/svc.c b/net/sunrpc/svc.c
index 75f290bddca1bbfd5c8a9db9bab1ac3d231f9ada..b94efd93d3e498a94bec4fee5eec8b9748052bdb 100644 (file)
--- a/net/sunrpc/svc.c
+++ b/net/sunrpc/svc.c
@@ -385,7 +385,7 @@ static int svc_uses_rpcbind(struct svc_serv *serv)
                for (i = 0; i < progp->pg_nvers; i++) {
                        if (progp->pg_vers[i] == NULL)
                                continue;
-                       if (progp->pg_vers[i]->vs_hidden == 0)
+                       if (!progp->pg_vers[i]->vs_hidden)
                                return 1;
                }
        }
@@ -976,6 +976,13 @@ int svc_register(const struct svc_serv *serv, struct net *net,
                        if (vers->vs_hidden)
                                continue;
 
+                       /*
+                        * Don't register a UDP port if we need congestion
+                        * control.
+                        */
+                       if (vers->vs_need_cong_ctrl && proto == IPPROTO_UDP)
+                               continue;
+
                        error = __svc_register(net, progp->pg_name, progp->pg_prog,
                                                i, family, proto, port);
 
@@ -1169,6 +1176,21 @@ svc_process_common(struct svc_rqst *rqstp, struct kvec *argv, struct kvec *resv)
          !(versp = progp->pg_vers[vers]))
                goto err_bad_vers;
 
+       /*
+        * Some protocol versions (namely NFSv4) require some form of
+        * congestion control.  (See RFC 7530 section 3.1 paragraph 2)
+        * In other words, UDP is not allowed. We mark those when setting
+        * up the svc_xprt, and verify that here.
+        *
+        * The spec is not very clear about what error should be returned
+        * when someone tries to access a server that is listening on UDP
+        * for lower versions. RPC_PROG_MISMATCH seems to be the closest
+        * fit.
+        */
+       if (versp->vs_need_cong_ctrl &&
+           !test_bit(XPT_CONG_CTRL, &rqstp->rq_xprt->xpt_flags))
+               goto err_bad_vers;
+
        procp = versp->vs_proc + proc;
        if (proc >= versp->vs_nproc || !procp->pc_func)
                goto err_bad_proc;
@@ -1260,7 +1282,7 @@ svc_process_common(struct svc_rqst *rqstp, struct kvec *argv, struct kvec *resv)
        return 0;
 
 err_short_len:
-       svc_printk(rqstp, "short len %Zd, dropping request\n",
+       svc_printk(rqstp, "short len %zd, dropping request\n",
                        argv->iov_len);
        goto close;