am-utils-6.2 - add get_nfs_xprt() and put_nfs_xprt() functions

From: Ian Kent <raven@themaw.net>

The nfs_quick_reply() functionality relies on taking a copy of the
current transport for later use.

The problem with this is the context of the RPC message is kept in
the transport and if any RPC message arrives before nfs_quick_reply()
is called that context will be corrupted.

So add a function get_nfs_xprt() to replace the current transport
with a new one returning the passed in transort so nfs_quick_reply()
can use it later.

A function put_nfs_xprt() is also added (although not really needed
since it just destroys the now unused transport) for completeness.

Signed-off-by: Ian Kent <raven@themaw.net>
---
 conf/transp/transp_sockets.c |   44 ++++++++++++++++++++++++++++++++++++++++
 conf/transp/transp_tli.c     |   46 +++++++++++++++++++++++++++++++++++++++++-
 include/am_utils.h           |    2 ++
 3 files changed, 91 insertions(+), 1 deletion(-)

diff --git a/conf/transp/transp_sockets.c b/conf/transp/transp_sockets.c
index 6326007..98f79c8 100644
--- a/conf/transp/transp_sockets.c
+++ b/conf/transp/transp_sockets.c
@@ -45,6 +45,7 @@
 #include <am_defs.h>
 #include <amu.h>
 
+static int soNFS = RPC_ANYSOCK;
 
 /*
  * find the IP address that can be used to connect to the local host
@@ -273,9 +274,52 @@ create_nfs_service(int *soNFSp, u_short *nfs_portp, SVCXPRT **nfs_xprtp, void (*
     return 3;
   }
 
+  soNFS = *soNFSp;
+
   return 0;			/* all is well */
 }
 
+/*
+ * Get a pointer to the current NFS SVCXPRT and replace it
+ * with a new one.
+ */
+SVCXPRT *
+get_nfs_xprt(SVCXPRT *nfs_xprt)
+{
+  SVCXPRT *newxprt;
+  int newfd;
+
+  if (!nfs_xprt || soNFS == RPC_ANYSOCK)
+    return NULL;
+
+  newfd = dup(soNFS);
+  if (newfd < 0)
+    return NULL;
+
+  xprt_unregister(nfs_xprt);
+  newxprt = svcudp_create(newfd);
+  if (!newxprt) {
+    plog(XLOG_FATAL, "Can't switch to new transport");
+    xprt_register(nfs_xprt);
+    close(newfd);
+    return NULL;
+  }
+
+  soNFS = newfd;
+
+  return nfs_xprt;
+}
+
+/*
+ * Destroy a transport previously obtained by get_nfs_xprt().
+ */
+void put_nfs_xprt(SVCXPRT *nfs_xprt)
+{
+  if (!nfs_xprt || soNFS == RPC_ANYSOCK)
+    return;
+
+  svc_destroy(nfs_xprt);
+}
 
 /*
  * Create the amq service for amd (both TCP and UDP)
diff --git a/conf/transp/transp_tli.c b/conf/transp/transp_tli.c
index d26a511..ea565cc 100644
--- a/conf/transp/transp_tli.c
+++ b/conf/transp/transp_tli.c
@@ -45,7 +45,8 @@
 #include <am_defs.h>
 #include <amu.h>
 
-struct netconfig *nfsncp;
+struct netconfig *nfsncp = NULL;
+static int soNFS = RPC_ANYSOCK;
 
 
 /*
@@ -456,9 +457,52 @@ create_nfs_service(int *soNFSp, u_short *nfs_portp, SVCXPRT **nfs_xprtp, void (*
     return 1;
   }
 
+  soNFS = *soNFSp;
+
   return 0;			/* all is well */
 }
 
+/*
+ * Get a pointer to the current NFS SVCXPRT and replace it
+ * with a new one.
+ */
+SVCXPRT *
+get_nfs_xprt(SVCXPRT *nfs_xprt)
+{
+  SVCXPRT *newxprt;
+  int newfd;
+
+  if (!nfs_xprt || soNFS == RPC_ANYSOCK)
+    return NULL;
+
+  newfd = dup(soNFS);
+  if (newfd < 0)
+    return NULL;
+
+  xprt_unregister(nfs_xprt);
+  newxprt = svc_tli_create(newfd, nfsncp, NULL, 0, 0);
+  if (!newxprt) {
+    plog(XLOG_FATAL, "Can't switch to new transport");
+    xprt_register(nfs_xprt);
+    close(newfd);
+    return NULL;
+  }
+
+  soNFS = newfd;
+
+  return nfs_xprt;
+}
+
+/*
+ * Destroy a transport previously obtained by get_nfs_xprt().
+ */
+void put_nfs_xprt(SVCXPRT *nfs_xprt)
+{
+  if (!nfs_xprt || soNFS == RPC_ANYSOCK)
+    return;
+
+  svc_destroy(nfs_xprt);
+}
 
 /*
  * Bind to preferred AMQ port.
diff --git a/include/am_utils.h b/include/am_utils.h
index 0de881a..ff13c26 100644
--- a/include/am_utils.h
+++ b/include/am_utils.h
@@ -378,6 +378,8 @@ extern void compute_nfs_args(void *nap, mntent_t *mntp, int genflags, struct net
 extern void destroy_nfs_args(void *nap, u_long nfs_version);
 extern int create_amq_service(int *udp_soAMQp, SVCXPRT **udp_amqpp, struct netconfig **udp_amqncpp, int *tcp_soAMQp, SVCXPRT **tcp_amqpp, struct netconfig **tcp_amqncpp, u_short preferred_amq_port);
 extern int create_nfs_service(int *soNFSp, u_short *nfs_portp, SVCXPRT **nfs_xprtp, void (*dispatch_fxn)(struct svc_req *rqstp, SVCXPRT *transp), u_long nfs_version);
+extern SVCXPRT *get_nfs_xprt(SVCXPRT *nfs_xprt);
+extern void put_nfs_xprt(SVCXPRT *nfs_xprt);
 extern int amu_svc_register(SVCXPRT *, u_long, u_long, void (*)(struct svc_req *, SVCXPRT *), u_long, struct netconfig *);
 
 #ifdef HAVE_TRANSPORT_TYPE_TLI