net/sunrpc/auth_null.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /*
0003  * linux/net/sunrpc/auth_null.c
0004  *
0005  * AUTH_NULL authentication. Really :-)
0006  *
0007  * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
0008  */
0009
0010 #include <linux/types.h>
0011 #include <linux/module.h>
0012 #include <linux/sunrpc/clnt.h>
0013
0014 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
0015 # define RPCDBG_FACILITY    RPCDBG_AUTH
0016 #endif
0017
0018 static struct rpc_auth null_auth;
0019 static struct rpc_cred null_cred;
0020
0021 static struct rpc_auth *
0022 nul_create(const struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
0023 {
0024     refcount_inc(&null_auth.au_count);
0025     return &null_auth;
0026 }
0027
0028 static void
0029 nul_destroy(struct rpc_auth *auth)
0030 {
0031 }
0032
0033 /*
0034  * Lookup NULL creds for current process
0035  */
0036 static struct rpc_cred *
0037 nul_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
0038 {
0039     return get_rpccred(&null_cred);
0040 }
0041
0042 /*
0043  * Destroy cred handle.
0044  */
0045 static void
0046 nul_destroy_cred(struct rpc_cred *cred)
0047 {
0048 }
0049
0050 /*
0051  * Match cred handle against current process
0052  */
0053 static int
0054 nul_match(struct auth_cred *acred, struct rpc_cred *cred, int taskflags)
0055 {
0056     return 1;
0057 }
0058
0059 /*
0060  * Marshal credential.
0061  */
0062 static int
0063 nul_marshal(struct rpc_task *task, struct xdr_stream *xdr)
0064 {
0065     __be32 *p;
0066
0067     p = xdr_reserve_space(xdr, 4 * sizeof(*p));
0068     if (!p)
0069         return -EMSGSIZE;
0070     /* Credential */
0071     *p++ = rpc_auth_null;
0072     *p++ = xdr_zero;
0073     /* Verifier */
0074     *p++ = rpc_auth_null;
0075     *p   = xdr_zero;
0076     return 0;
0077 }
0078
0079 /*
0080  * Refresh credential. This is a no-op for AUTH_NULL
0081  */
0082 static int
0083 nul_refresh(struct rpc_task *task)
0084 {
0085     set_bit(RPCAUTH_CRED_UPTODATE, &task->tk_rqstp->rq_cred->cr_flags);
0086     return 0;
0087 }
0088
0089 static int
0090 nul_validate(struct rpc_task *task, struct xdr_stream *xdr)
0091 {
0092     __be32 *p;
0093
0094     p = xdr_inline_decode(xdr, 2 * sizeof(*p));
0095     if (!p)
0096         return -EIO;
0097     if (*p++ != rpc_auth_null)
0098         return -EIO;
0099     if (*p != xdr_zero)
0100         return -EIO;
0101     return 0;
0102 }
0103
0104 const struct rpc_authops authnull_ops = {
0105     .owner      = THIS_MODULE,
0106     .au_flavor  = RPC_AUTH_NULL,
0107     .au_name    = "NULL",
0108     .create     = nul_create,
0109     .destroy    = nul_destroy,
0110     .lookup_cred    = nul_lookup_cred,
0111 };
0112
0113 static
0114 struct rpc_auth null_auth = {
0115     .au_cslack  = NUL_CALLSLACK,
0116     .au_rslack  = NUL_REPLYSLACK,
0117     .au_verfsize    = NUL_REPLYSLACK,
0118     .au_ralign  = NUL_REPLYSLACK,
0119     .au_ops     = &authnull_ops,
0120     .au_flavor  = RPC_AUTH_NULL,
0121     .au_count   = REFCOUNT_INIT(1),
0122 };
0123
0124 static
0125 const struct rpc_credops null_credops = {
0126     .cr_name    = "AUTH_NULL",
0127     .crdestroy  = nul_destroy_cred,
0128     .crmatch    = nul_match,
0129     .crmarshal  = nul_marshal,
0130     .crwrap_req = rpcauth_wrap_req_encode,
0131     .crrefresh  = nul_refresh,
0132     .crvalidate = nul_validate,
0133     .crunwrap_resp  = rpcauth_unwrap_resp_decode,
0134 };
0135
0136 static
0137 struct rpc_cred null_cred = {
0138     .cr_lru     = LIST_HEAD_INIT(null_cred.cr_lru),
0139     .cr_auth    = &null_auth,
0140     .cr_ops     = &null_credops,
0141     .cr_count   = REFCOUNT_INIT(2),
0142     .cr_flags   = 1UL << RPCAUTH_CRED_UPTODATE,
0143 };