4 files changed, 20 insertions, 0 deletions

diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h
index 04e763221246..a0dbbd1e00e9 100644
--- a/include/linux/sunrpc/svc.h
+++ b/include/linux/sunrpc/svc.h
@@ -254,6 +254,7 @@ struct svc_rqst {
         u32                     rq_prot;        /* IP protocol */
         unsigned short
                                 rq_secure  : 1; /* secure port */
+        unsigned short          rq_local   : 1; /* local request */
 
         void *                  rq_argp;        /* decoded arguments */
         void *                  rq_resp;        /* xdr'd results */
diff --git a/include/linux/sunrpc/svc_xprt.h b/include/linux/sunrpc/svc_xprt.h
index 0cec1b94c670..7235040a19b2 100644
--- a/include/linux/sunrpc/svc_xprt.h
+++ b/include/linux/sunrpc/svc_xprt.h
@@ -64,6 +64,7 @@ struct svc_xprt {
 #define XPT_DETACHED    10              /* detached from tempsocks list */
 #define XPT_LISTENER    11              /* listening endpoint */
 #define XPT_CACHE_AUTH  12              /* cache auth info */
+#define XPT_LOCAL       13              /* connection from loopback interface */
 
         struct svc_serv         *xpt_server;    /* service for transport */
         atomic_t                xpt_reserved;   /* space on outq that is rsvd */
diff --git a/net/sunrpc/sunrpc.h b/net/sunrpc/sunrpc.h
index 14c9f6d1c5ff..f2b7cb540e61 100644
--- a/net/sunrpc/sunrpc.h
+++ b/net/sunrpc/sunrpc.h
@@ -43,6 +43,19 @@ static inline int rpc_reply_expected(struct rpc_task *task)
                 (task->tk_msg.rpc_proc->p_decode != NULL);
 }
 
+static inline int sock_is_loopback(struct sock *sk)
+{
+        struct dst_entry *dst;
+        int loopback = 0;
+        rcu_read_lock();
+        dst = rcu_dereference(sk->sk_dst_cache);
+        if (dst && dst->dev &&
+            (dst->dev->features & NETIF_F_LOOPBACK))
+                loopback = 1;
+        rcu_read_unlock();
+        return loopback;
+}
+
 int svc_send_common(struct socket *sock, struct xdr_buf *xdr,
                     struct page *headpage, unsigned long headoffset,
                     struct page *tailpage, unsigned long tailoffset);
diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c
index 0cb34f5d58dc..f3b8eb309d01 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -874,6 +874,10 @@ static struct svc_xprt *svc_tcp_accept(struct svc_xprt *xprt)
         }
         svc_xprt_set_local(&newsvsk->sk_xprt, sin, slen);
 
+        if (sock_is_loopback(newsock->sk))
+                set_bit(XPT_LOCAL, &newsvsk->sk_xprt.xpt_flags);
+        else
+                clear_bit(XPT_LOCAL, &newsvsk->sk_xprt.xpt_flags);
         if (serv->sv_stats)
                 serv->sv_stats->nettcpconn++;
 
@@ -1119,6 +1123,7 @@ static int svc_tcp_recvfrom(struct svc_rqst *rqstp)
 
         rqstp->rq_xprt_ctxt   = NULL;
         rqstp->rq_prot        = IPPROTO_TCP;
+        rqstp->rq_local       = !!test_bit(XPT_LOCAL, &svsk->sk_xprt.xpt_flags);
 
         p = (__be32 *)rqstp->rq_arg.head[0].iov_base;
         calldir = p[1];