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 __be32 *
  90 nul_validate(struct rpc_task *task, __be32 *p)
  91 {
  92         rpc_authflavor_t        flavor;
  93         u32                     size;
  94
  95         flavor = ntohl(*p++);
  96         if (flavor != RPC_AUTH_NULL) {
  97                 printk("RPC: bad verf flavor: %u\n", flavor);
  98                 return ERR_PTR(-EIO);
  99         }
 100
 101         size = ntohl(*p++);
 102         if (size != 0) {
 103                 printk("RPC: bad verf size: %u\n", size);
 104                 return ERR_PTR(-EIO);
 105         }
 106
 107         return p;
 108 }
 109
 110 const struct rpc_authops authnull_ops = {
 111         .owner          = THIS_MODULE,
 112         .au_flavor      = RPC_AUTH_NULL,
 113         .au_name        = "NULL",
 114         .create         = nul_create,
 115         .destroy        = nul_destroy,
 116         .lookup_cred    = nul_lookup_cred,
 117 };
 118
 119 static
 120 struct rpc_auth null_auth = {
 121         .au_cslack      = NUL_CALLSLACK,
 122         .au_rslack      = NUL_REPLYSLACK,
 123         .au_ops         = &authnull_ops,
 124         .au_flavor      = RPC_AUTH_NULL,
 125         .au_count       = REFCOUNT_INIT(1),
 126 };
 127
 128 static
 129 const struct rpc_credops null_credops = {
 130         .cr_name        = "AUTH_NULL",
 131         .crdestroy      = nul_destroy_cred,
 132         .crmatch        = nul_match,
 133         .crmarshal      = nul_marshal,
 134         .crwrap_req     = rpcauth_wrap_req_encode,
 135         .crrefresh      = nul_refresh,
 136         .crvalidate     = nul_validate,
 137 };
 138
 139 static
 140 struct rpc_cred null_cred = {
 141         .cr_lru         = LIST_HEAD_INIT(null_cred.cr_lru),
 142         .cr_auth        = &null_auth,
 143         .cr_ops         = &null_credops,
 144         .cr_count       = REFCOUNT_INIT(2),
 145         .cr_flags       = 1UL << RPCAUTH_CRED_UPTODATE,
 146 };