[PATCH 05/19] SUNRPC: track whether a request is coming from a loop-back interface.

NeilBrown
2014-04-16T04:18:25Z

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>
---
include/linux/sunrpc/svc.h | 1 +
include/linux/sunrpc/svc_xprt.h | 1 +
net/sunrpc/svcsock.c | 10 ++++++++++
3 files changed, 12 insertions(+)

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 b05963f09ebf..b99bdfb0fcf9 100644
--- a/include/linux/sunrpc/svc_xprt.h
+++ b/include/linux/sunrpc/svc_xprt.h
@@ -63,6 +63,7 @@ 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/svcsock.c b/net/sunrpc/svcsock.c
index b6e59f0a9475..193115fe968c 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -811,6 +811,7 @@ static struct svc_xprt *svc_tcp_accept(struct svc_xprt *xprt)
struct socket *newsock;
struct svc_sock *newsvsk;
int err, slen;
+ struct dst_entry *dst;
RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);

dprintk("svc: tcp_accept %p sock %p\n", svsk, sock);
@@ -867,6 +868,14 @@ static struct svc_xprt *svc_tcp_accept(struct svc_xprt *xprt)
}
svc_xprt_set_local(&newsvsk->sk_xprt, sin, slen);

+ clear_bit(XPT_LOCAL, &newsvsk->sk_xprt.xpt_flags);
+ rcu_read_lock();
+ dst = rcu_dereference(newsock->sk->sk_dst_cache);
+ if (dst && dst->dev &&
+ (dst->dev->features & NETIF_F_LOOPBACK))
+ set_bit(XPT_LOCAL, &newsvsk->sk_xprt.xpt_flags);
+ rcu_read_unlock();
+
if (serv->sv_stats)
serv->sv_stats->nettcpconn++;

@@ -1112,6 +1121,7 @@ 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];