net/sunrpc/auth_null.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * linux/net/sunrpc/auth_null.c
   4  *
   5  * AUTH_NULL authentication. Really :-)
   6  *
   7  * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
   8  */
   9
  10 #include <linux/types.h>
  11 #include <linux/module.h>
  12 #include <linux/sunrpc/clnt.h>
  13
  14 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  15 # define RPCDBG_FACILITY        RPCDBG_AUTH
  16 #endif
  17
  18 static struct rpc_auth null_auth;
  19 static struct rpc_cred null_cred;
  20
  21 static struct rpc_auth *
  22 nul_create(const struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
  23 {
  24         refcount_inc(&null_auth.au_count);
  25         return &null_auth;
  26 }
  27
  28 static void
  29 nul_destroy(struct rpc_auth *auth)
  30 {
  31 }
  32
  33 /*
  34  * Lookup NULL creds for current process
  35  */
  36 static struct rpc_cred *
  37 nul_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
  38 {
  39         return get_rpccred(&null_cred);
  40 }
  41
  42 /*
  43  * Destroy cred handle.
  44  */
  45 static void
  46 nul_destroy_cred(struct rpc_cred *cred)
  47 {
  48 }
  49
  50 /*
  51  * Match cred handle against current process
  52  */
  53 static int
  54 nul_match(struct auth_cred *acred, struct rpc_cred *cred, int taskflags)
  55 {
  56         return 1;
  57 }
  58
  59 /*
  60  * Marshal credential.
  61  */
  62 static int
  63 nul_marshal(struct rpc_task *task, struct xdr_stream *xdr)
  64 {
  65         __be32 *p;
  66
  67         p = xdr_reserve_space(xdr, 4 * sizeof(*p));
  68         if (!p)
  69                 return -EMSGSIZE;
  70         /* Credential */
  71         *p++ = rpc_auth_null;
  72         *p++ = xdr_zero;
  73         /* Verifier */
  74         *p++ = rpc_auth_null;
  75         *p   = xdr_zero;
  76         return 0;
  77 }
  78
  79 /*
  80  * Refresh credential. This is a no-op for AUTH_NULL
  81  */
  82 static int
  83 nul_refresh(struct rpc_task *task)
  84 {
  85         set_bit(RPCAUTH_CRED_UPTODATE, &task->tk_rqstp->rq_cred->cr_flags);
  86         return 0;
  87 }
  88
  89 static int
  90 nul_validate(struct rpc_task *task, struct xdr_stream *xdr)
  91 {
  92         __be32 *p;
  93
  94         p = xdr_inline_decode(xdr, 2 * sizeof(*p));
  95         if (!p)
  96                 return -EIO;
  97         if (*p++ != rpc_auth_null)
  98                 return -EIO;
  99         if (*p != xdr_zero)
 100                 return -EIO;
 101         return 0;
 102 }
 103
 104 const struct rpc_authops authnull_ops = {
 105         .owner          = THIS_MODULE,
 106         .au_flavor      = RPC_AUTH_NULL,
 107         .au_name        = "NULL",
 108         .create         = nul_create,
 109         .destroy        = nul_destroy,
 110         .lookup_cred    = nul_lookup_cred,
 111 };
 112
 113 static
 114 struct rpc_auth null_auth = {
 115         .au_cslack      = NUL_CALLSLACK,
 116         .au_rslack      = NUL_REPLYSLACK,
 117         .au_verfsize    = NUL_REPLYSLACK,
 118         .au_ralign      = NUL_REPLYSLACK,
 119         .au_ops         = &authnull_ops,
 120         .au_flavor      = RPC_AUTH_NULL,
 121         .au_count       = REFCOUNT_INIT(1),
 122 };
 123
 124 static
 125 const struct rpc_credops null_credops = {
 126         .cr_name        = "AUTH_NULL",
 127         .crdestroy      = nul_destroy_cred,
 128         .crmatch        = nul_match,
 129         .crmarshal      = nul_marshal,
 130         .crwrap_req     = rpcauth_wrap_req_encode,
 131         .crrefresh      = nul_refresh,
 132         .crvalidate     = nul_validate,
 133         .crunwrap_resp  = rpcauth_unwrap_resp_decode,
 134 };
 135
 136 static
 137 struct rpc_cred null_cred = {
 138         .cr_lru         = LIST_HEAD_INIT(null_cred.cr_lru),
 139         .cr_auth        = &null_auth,
 140         .cr_ops         = &null_credops,
 141         .cr_count       = REFCOUNT_INIT(2),
 142         .cr_flags       = 1UL << RPCAUTH_CRED_UPTODATE,
 143 };