nfs4.1: Minimal SP4_MACH_CRED implementation
This is a minimal client side implementation of SP4_MACH_CRED. It will
attempt to negotiate SP4_MACH_CRED iff the EXCHANGE_ID is using
krb5i or krb5p auth. SP4_MACH_CRED will be used if the server supports the
minimal operations:
BIND_CONN_TO_SESSION
EXCHANGE_ID
CREATE_SESSION
DESTROY_SESSION
DESTROY_CLIENTID
This patch only includes the EXCHANGE_ID negotiation code because
the client will already use the machine cred for these operations.
If the server doesn't support SP4_MACH_CRED or doesn't support the minimal
operations, the exchange id will be resent with SP4_NONE.
Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 535011a..ab6ee1d 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -6117,16 +6117,87 @@
}
/*
- * 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.
+ * Minimum set of SP4_MACH_CRED operations from RFC 5661
*/
-int nfs4_proc_exchange_id(struct nfs_client *clp, struct rpc_cred *cred)
+static const struct nfs41_state_protection nfs4_sp4_mach_cred_request = {
+ .how = SP4_MACH_CRED,
+ .enforce.u.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 0 on success, negative errno otherwise.
+ */
+static int nfs4_sp4_select_mode(struct nfs_client *clp,
+ struct nfs41_state_protection *sp)
+{
+ static const u32 supported_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)
+ };
+ 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))
+ dfprintk(MOUNT, " enforce op %d\n", i);
+ if (test_bit(i, sp->allow.u.longs))
+ dfprintk(MOUNT, " allow op %d\n", i);
+ }
+
+ /* make sure nothing is on enforce list that isn't supported */
+ for (i = 0; i < NFS4_OP_MAP_NUM_WORDS; i++) {
+ if (sp->enforce.u.words[i] & ~supported_enforce[i]) {
+ dfprintk(MOUNT, "sp4_mach_cred: disabled\n");
+ return -EINVAL;
+ }
+ }
+
+ /*
+ * 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.
+ *
+ * NOTE: we don't care if EXCHANGE_ID is in the list -
+ * we're already using the machine cred for exchange_id
+ * and will never use a different cred.
+ */
+ if (test_bit(OP_BIND_CONN_TO_SESSION, sp->enforce.u.longs) &&
+ test_bit(OP_CREATE_SESSION, sp->enforce.u.longs) &&
+ test_bit(OP_DESTROY_SESSION, sp->enforce.u.longs) &&
+ test_bit(OP_DESTROY_CLIENTID, sp->enforce.u.longs)) {
+ dfprintk(MOUNT, "sp4_mach_cred:\n");
+ dfprintk(MOUNT, " minimal mode enabled\n");
+ set_bit(NFS_SP4_MACH_CRED_MINIMAL, &clp->cl_sp4_flags);
+ } else {
+ dfprintk(MOUNT, "sp4_mach_cred: disabled\n");
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * _nfs4_proc_exchange_id()
+ *
+ * Wrapper for EXCHANGE_ID operation.
+ */
+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 = {
@@ -6173,11 +6244,30 @@
goto out_server_scope;
}
+ switch (sp4_how) {
+ case SP4_NONE:
+ args.state_protect.how = SP4_NONE;
+ break;
+
+ case SP4_MACH_CRED:
+ args.state_protect = nfs4_sp4_mach_cred_request;
+ break;
+
+ default:
+ /* unsupported! */
+ WARN_ON_ONCE(1);
+ status = -EINVAL;
+ goto out_server_scope;
+ }
+
status = rpc_call_sync(clp->cl_rpcclient, &msg, RPC_TASK_TIMEOUT);
trace_nfs4_exchange_id(clp, status);
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);
@@ -6224,6 +6314,35 @@
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)
{