SUNRPC: track whether a request is coming from a loop-back interface.

If an incoming NFS request is coming from the local host, then
nfsd will need to perform some special handling.  So detect that
possibility and make the source visible in rq_local.

Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

diff --git a/include/linux/sunrpc/svc.h b/include/linux/sunrpc/svc.h
index 04e76322124634af03ec734996184a5b76b5e528..a0dbbd1e00e97ac4766c45029d068faa9b136f4a 100644 (file)
--- 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 0cec1b94c67056abb21bdb277e9c0580b3d35f64..7235040a19b2caecb8ea7043a1bc9cdf20535dda 100644 (file)
--- 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 14c9f6d1c5ff22987e6dfdbf2ce9a95508ee4696..f2b7cb540e61997ce427e132f7d0f20cada5a46e 100644 (file)
--- 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 0cb34f5d58dc61f7dbab6e6883c6b545b5b64eec..f3b8eb309d014a30e014ec4bac30266a38203627 100644 (file)
--- 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];