1 files changed, 49 insertions, 43 deletions

diff --git a/fs/nfs/callback.c b/fs/nfs/callback.c
index 93a8b3bd69e3..e3d294269058 100644
--- a/fs/nfs/callback.c
+++ b/fs/nfs/callback.c
@@ -16,9 +16,7 @@
 #include <linux/freezer.h>
 #include <linux/kthread.h>
 #include <linux/sunrpc/svcauth_gss.h>
-#if defined(CONFIG_NFS_V4_1)
 #include <linux/sunrpc/bc_xprt.h>
-#endif
 
 #include <net/inet_sock.h>
 
@@ -177,30 +175,38 @@ nfs41_callback_svc(void *vrqstp)
 struct svc_rqst *
 nfs41_callback_up(struct svc_serv *serv, struct rpc_xprt *xprt)
 {
-        struct svc_xprt *bc_xprt;
-        struct svc_rqst *rqstp = ERR_PTR(-ENOMEM);
+        struct svc_rqst *rqstp;
+        int ret;
 
-        dprintk("--> %s\n", __func__);
-        /* Create a svc_sock for the service */
-        bc_xprt = svc_sock_create(serv, xprt->prot);
-        if (!bc_xprt)
+        /*
+         * Create an svc_sock for the back channel service that shares the
+         * fore channel connection.
+         * Returns the input port (0) and sets the svc_serv bc_xprt on success
+         */
+        ret = svc_create_xprt(serv, "tcp-bc", &init_net, PF_INET, 0,
+                              SVC_SOCK_ANONYMOUS);
+        if (ret < 0) {
+                rqstp = ERR_PTR(ret);
                 goto out;
+        }
 
         /*
          * Save the svc_serv in the transport so that it can
          * be referenced when the session backchannel is initialized
          */
-        serv->bc_xprt = bc_xprt;
         xprt->bc_serv = serv;
 
         INIT_LIST_HEAD(&serv->sv_cb_list);
         spin_lock_init(&serv->sv_cb_lock);
         init_waitqueue_head(&serv->sv_cb_waitq);
         rqstp = svc_prepare_thread(serv, &serv->sv_pools[0]);
-        if (IS_ERR(rqstp))
-                svc_sock_destroy(bc_xprt);
+        if (IS_ERR(rqstp)) {
+                svc_xprt_put(serv->sv_bc_xprt);
+                serv->sv_bc_xprt = NULL;
+        }
 out:
-        dprintk("--> %s return %p\n", __func__, rqstp);
+        dprintk("--> %s return %ld\n", __func__,
+                IS_ERR(rqstp) ? PTR_ERR(rqstp) : 0);
         return rqstp;
 }
 
@@ -322,58 +328,58 @@ void nfs_callback_down(int minorversion)
         mutex_unlock(&nfs_callback_mutex);
 }
 
-static int check_gss_callback_principal(struct nfs_client *clp,
-                                        struct svc_rqst *rqstp)
+/* Boolean check of RPC_AUTH_GSS principal */
+int
+check_gss_callback_principal(struct nfs_client *clp, struct svc_rqst *rqstp)
 {
         struct rpc_clnt *r = clp->cl_rpcclient;
         char *p = svc_gss_principal(rqstp);
 
+        if (rqstp->rq_authop->flavour != RPC_AUTH_GSS)
+                return 1;
+
+        /* No RPC_AUTH_GSS on NFSv4.1 back channel yet */
+        if (clp->cl_minorversion != 0)
+                return 0;
         /*
          * It might just be a normal user principal, in which case
          * userspace won't bother to tell us the name at all.
          */
         if (p == NULL)
-                return SVC_DENIED;
+                return 0;
 
         /* Expect a GSS_C_NT_HOSTBASED_NAME like "nfs@serverhostname" */
 
         if (memcmp(p, "nfs@", 4) != 0)
-                return SVC_DENIED;
+                return 0;
         p += 4;
         if (strcmp(p, r->cl_server) != 0)
-                return SVC_DENIED;
-        return SVC_OK;
+                return 0;
+        return 1;
 }
 
+/*
+ * pg_authenticate method for nfsv4 callback threads.
+ *
+ * The authflavor has been negotiated, so an incorrect flavor is a server
+ * bug. Drop packets with incorrect authflavor.
+ *
+ * All other checking done after NFS decoding where the nfs_client can be
+ * found in nfs4_callback_compound
+ */
 static int nfs_callback_authenticate(struct svc_rqst *rqstp)
 {
-        struct nfs_client *clp;
-        RPC_IFDEBUG(char buf[RPC_MAX_ADDRBUFLEN]);
-        int ret = SVC_OK;
-
-        /* Don't talk to strangers */
-        clp = nfs_find_client(svc_addr(rqstp), 4);
-        if (clp == NULL)
-                return SVC_DROP;
-
-        dprintk("%s: %s NFSv4 callback!\n", __func__,
-                        svc_print_addr(rqstp, buf, sizeof(buf)));
-
         switch (rqstp->rq_authop->flavour) {
-                case RPC_AUTH_NULL:
-                        if (rqstp->rq_proc != CB_NULL)
-                                ret = SVC_DENIED;
-                        break;
-                case RPC_AUTH_UNIX:
-                        break;
-                case RPC_AUTH_GSS:
-                        ret = check_gss_callback_principal(clp, rqstp);
-                        break;
-                default:
-                        ret = SVC_DENIED;
+        case RPC_AUTH_NULL:
+                if (rqstp->rq_proc != CB_NULL)
+                        return SVC_DROP;
+                break;
+        case RPC_AUTH_GSS:
+                /* No RPC_AUTH_GSS support yet in NFSv4.1 */
+                 if (svc_is_backchannel(rqstp))
+                        return SVC_DROP;
         }
-        nfs_put_client(clp);
-        return ret;
+        return SVC_OK;
 }
 
 /*