nfs4.1: Minimal SP4_MACH_CRED implementation

index 0e64ccc..b9f5dac 100644
@@ -5915,16 +5915,63 @@ out:
 }
 
 /*
- * nfs4_proc_exchange_id()
+ * Minimum set of SP4_MACH_CRED operations from RFC 5661
+ */
+static uint32_t _nfs4_spo_must_enforce[NFS4_OP_MAP_NUM_WORDS] = {
+	[1] = 1 << (OP_BIND_CONN_TO_SESSION - 32) |
+	      1 << (OP_EXCHANGE_ID - 32) |
+	      1 << (OP_CREATE_SESSION - 32) |
+	      1 << (OP_DESTROY_SESSION - 32) |
+	      1 << (OP_DESTROY_CLIENTID - 32)
+};
+
+/*
+ * Select the state protection mode for client `clp' given the server results
+ * from exchange_id in `sp'.
  *
- * Returns zero, a negative errno, or a negative NFS4ERR status code.
+ * Returns 0 on success, negative errno otherwise.
+ */
+static int _nfs4_sp4_select_mode(struct nfs_client *clp,
+				 struct nfs41_state_protection *sp)
+{
+	unsigned int i;
+
+	if (sp->how == SP4_MACH_CRED) {
+		/* Print state protect result */
+		dfprintk(MOUNT, "Server SP4_MACH_CRED support:\n");
+		for (i = 0; i <= LAST_NFS4_OP; i++) {
+			if (test_bit(i, &sp->enforce.u.longs[0]))
+				dfprintk(MOUNT, "  enforce op %d\n", i);
+			if (test_bit(i, &sp->allow.u.longs[0]))
+				dfprintk(MOUNT, "  allow op %d\n", i);
+		}
+
+		/*
+		 * Minimal mode - state operations are allowed to use machine
+		 * credential.  Note this already happens by default, so the
+		 * client doesn't have to do anything more than the negotiation.
+		 */
+		if (memcmp(sp->enforce.u.words, _nfs4_spo_must_enforce,
+			   sizeof(sp->enforce.u.words)) == 0)
+			set_bit(NFS_SP4_MACH_CRED_MINIMAL, &clp->cl_sp4_flags);
+
+		if (!clp->cl_sp4_flags) {
+			dfprintk(MOUNT, "sp4_mach_cred: disabled\n");
+			return -EINVAL;
+		} else
+			dfprintk(MOUNT, "sp4_mach_cred: enabled\n");
+	}
+
+	return 0;
+}
+
+/*
+ * _nfs4_proc_exchange_id()
  *
- * Since the clientid has expired, all compounds using sessions
- * associated with the stale clientid will be returning
- * NFS4ERR_BADSESSION in the sequence operation, and will therefore
- * be in some phase of session reset.
+ * Wrapper for EXCHANGE_ID operation.
  */
-int nfs4_proc_exchange_id(struct nfs_client *clp, struct rpc_cred *cred)
+static int _nfs4_proc_exchange_id(struct nfs_client *clp, struct rpc_cred *cred,
+	u32 sp4_how)
 {
 	nfs4_verifier verifier;
 	struct nfs41_exchange_id_args args = {

@@ -5971,10 +6018,35 @@ int nfs4_proc_exchange_id(struct nfs_client *clp, struct rpc_cred *cred)
 		goto out_server_scope;
 	}
 
+	switch (sp4_how) {
+	case SP4_NONE:
+		args.state_protect.how = SP4_NONE;
+		break;
+
+	case SP4_MACH_CRED:
+		args.state_protect.how = SP4_MACH_CRED;
+
+		/* request minumum set op operations */
+		memcpy(args.state_protect.enforce.u.words,
+		       &_nfs4_spo_must_enforce,
+		       sizeof(uint32_t) * NFS4_OP_MAP_NUM_WORDS);
+
+		break;
+
+	default:
+		/* unsupportd! */
+		WARN_ON_ONCE(1);
+		status = -EINVAL;
+		goto out_server_scope;
+	}
+
 	status = rpc_call_sync(clp->cl_rpcclient, &msg, RPC_TASK_TIMEOUT);
 	if (status == 0)
 		status = nfs4_check_cl_exchange_flags(res.flags);
 
+	if (status == 0)
+		status = _nfs4_sp4_select_mode(clp, &res.state_protect);
+
 	if (status == 0) {
 		clp->cl_clientid = res.clientid;
 		clp->cl_exchange_flags = (res.flags & ~EXCHGID4_FLAG_CONFIRMED_R);

@@ -6021,6 +6093,35 @@ out:
 	return status;
 }
 
+/*
+ * nfs4_proc_exchange_id()
+ *
+ * Returns zero, a negative errno, or a negative NFS4ERR status code.
+ *
+ * Since the clientid has expired, all compounds using sessions
+ * associated with the stale clientid will be returning
+ * NFS4ERR_BADSESSION in the sequence operation, and will therefore
+ * be in some phase of session reset.
+ *
+ * Will attempt to negotiate SP4_MACH_CRED if krb5i / krb5p auth is used.
+ */
+int nfs4_proc_exchange_id(struct nfs_client *clp, struct rpc_cred *cred)
+{
+	rpc_authflavor_t authflavor = clp->cl_rpcclient->cl_auth->au_flavor;
+	int status;
+
+	/* try SP4_MACH_CRED if krb5i/p	*/
+	if (authflavor == RPC_AUTH_GSS_KRB5I ||
+	    authflavor == RPC_AUTH_GSS_KRB5P) {
+		status = _nfs4_proc_exchange_id(clp, cred, SP4_MACH_CRED);
+		if (!status)
+			return 0;
+	}
+
+	/* try SP4_NONE */
+	return _nfs4_proc_exchange_id(clp, cred, SP4_NONE);
+}
+
 static int _nfs4_proc_destroy_clientid(struct nfs_client *clp,
 		struct rpc_cred *cred)
 {

122 lines not on this page · raw message

index d221243..a0af429 100644
@@ -87,6 +87,10 @@ struct nfs_client {
 	struct nfs41_server_owner *cl_serverowner;
 	struct nfs41_server_scope *cl_serverscope;
 	struct nfs41_impl_id	*cl_implid;
+	/* nfs 4.1+ state protection modes: */
+	unsigned long		cl_sp4_flags;
+#define NFS_SP4_MACH_CRED_MINIMAL  1	/* Minimal sp4_mach_cred - state ops
+					 * must use machine cred */
 #endif /* CONFIG_NFS_V4 */
 
 #ifdef CONFIG_NFS_FSCACHE

index 8651574..18681d9 100644
@@ -1107,6 +1107,23 @@ struct pnfs_ds_commit_info {
 	struct pnfs_commit_bucket *buckets;
 };
 
+#define NFS4_OP_MAP_NUM_LONGS \
+	DIV_ROUND_UP(LAST_NFS4_OP, 8 * sizeof(unsigned long))
+#define NFS4_OP_MAP_NUM_WORDS \
+	(NFS4_OP_MAP_NUM_LONGS * sizeof(unsigned long) / sizeof(u32))
+struct nfs4_op_map {
+	union {
+		unsigned long longs[NFS4_OP_MAP_NUM_LONGS];
+		u32 words[NFS4_OP_MAP_NUM_WORDS];
+	} u;
+};
+
+struct nfs41_state_protection {
+	u32 how;
+	struct nfs4_op_map enforce;
+	struct nfs4_op_map allow;
+};
+
 #define NFS4_EXCHANGE_ID_LEN	(48)
 struct nfs41_exchange_id_args {
 	struct nfs_client		*client;

@@ -1114,6 +1131,7 @@ struct nfs41_exchange_id_args {
 	unsigned int 			id_len;
 	char 				id[NFS4_EXCHANGE_ID_LEN];
 	u32				flags;
+	struct nfs41_state_protection	state_protect;
 };
 
 struct nfs41_server_owner {

@@ -1146,6 +1164,7 @@ struct nfs41_exchange_id_res {
 	struct nfs41_server_owner	*server_owner;
 	struct nfs41_server_scope	*server_scope;
 	struct nfs41_impl_id		*impl_id;
+	struct nfs41_state_protection	state_protect;
 };
 
 struct nfs41_create_session_args {