1 /*
2  * linux/net/sunrpc/auth_null.c
3  *
4  * AUTH_NULL authentication. Really :-)
5  *
6  * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
7  */
8 
9 #include <linux/types.h>
10 #include <linux/module.h>
11 #include <linux/sunrpc/clnt.h>
12 
13 #ifdef RPC_DEBUG
14 # define RPCDBG_FACILITY	RPCDBG_AUTH
15 #endif
16 
17 static struct rpc_auth null_auth;
18 static struct rpc_cred null_cred;
19 
20 static struct rpc_auth *
nul_create(struct rpc_clnt * clnt,rpc_authflavor_t flavor)21 nul_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
22 {
23 	atomic_inc(&null_auth.au_count);
24 	return &null_auth;
25 }
26 
27 static void
nul_destroy(struct rpc_auth * auth)28 nul_destroy(struct rpc_auth *auth)
29 {
30 }
31 
32 /*
33  * Lookup NULL creds for current process
34  */
35 static struct rpc_cred *
nul_lookup_cred(struct rpc_auth * auth,struct auth_cred * acred,int flags)36 nul_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
37 {
38 	return get_rpccred(&null_cred);
39 }
40 
41 /*
42  * Destroy cred handle.
43  */
44 static void
nul_destroy_cred(struct rpc_cred * cred)45 nul_destroy_cred(struct rpc_cred *cred)
46 {
47 }
48 
49 /*
50  * Match cred handle against current process
51  */
52 static int
nul_match(struct auth_cred * acred,struct rpc_cred * cred,int taskflags)53 nul_match(struct auth_cred *acred, struct rpc_cred *cred, int taskflags)
54 {
55 	return 1;
56 }
57 
58 /*
59  * Marshal credential.
60  */
61 static __be32 *
nul_marshal(struct rpc_task * task,__be32 * p)62 nul_marshal(struct rpc_task *task, __be32 *p)
63 {
64 	*p++ = htonl(RPC_AUTH_NULL);
65 	*p++ = 0;
66 	*p++ = htonl(RPC_AUTH_NULL);
67 	*p++ = 0;
68 
69 	return p;
70 }
71 
72 /*
73  * Refresh credential. This is a no-op for AUTH_NULL
74  */
75 static int
nul_refresh(struct rpc_task * task)76 nul_refresh(struct rpc_task *task)
77 {
78 	set_bit(RPCAUTH_CRED_UPTODATE, &task->tk_rqstp->rq_cred->cr_flags);
79 	return 0;
80 }
81 
82 static __be32 *
nul_validate(struct rpc_task * task,__be32 * p)83 nul_validate(struct rpc_task *task, __be32 *p)
84 {
85 	rpc_authflavor_t	flavor;
86 	u32			size;
87 
88 	flavor = ntohl(*p++);
89 	if (flavor != RPC_AUTH_NULL) {
90 		printk("RPC: bad verf flavor: %u\n", flavor);
91 		return NULL;
92 	}
93 
94 	size = ntohl(*p++);
95 	if (size != 0) {
96 		printk("RPC: bad verf size: %u\n", size);
97 		return NULL;
98 	}
99 
100 	return p;
101 }
102 
103 const struct rpc_authops authnull_ops = {
104 	.owner		= THIS_MODULE,
105 	.au_flavor	= RPC_AUTH_NULL,
106 	.au_name	= "NULL",
107 	.create		= nul_create,
108 	.destroy	= nul_destroy,
109 	.lookup_cred	= nul_lookup_cred,
110 };
111 
112 static
113 struct rpc_auth null_auth = {
114 	.au_cslack	= 4,
115 	.au_rslack	= 2,
116 	.au_ops		= &authnull_ops,
117 	.au_flavor	= RPC_AUTH_NULL,
118 	.au_count	= ATOMIC_INIT(0),
119 };
120 
121 static
122 const struct rpc_credops null_credops = {
123 	.cr_name	= "AUTH_NULL",
124 	.crdestroy	= nul_destroy_cred,
125 	.crbind		= rpcauth_generic_bind_cred,
126 	.crmatch	= nul_match,
127 	.crmarshal	= nul_marshal,
128 	.crrefresh	= nul_refresh,
129 	.crvalidate	= nul_validate,
130 };
131 
132 static
133 struct rpc_cred null_cred = {
134 	.cr_lru		= LIST_HEAD_INIT(null_cred.cr_lru),
135 	.cr_auth	= &null_auth,
136 	.cr_ops		= &null_credops,
137 	.cr_count	= ATOMIC_INIT(1),
138 	.cr_flags	= 1UL << RPCAUTH_CRED_UPTODATE,
139 #ifdef RPC_DEBUG
140 	.cr_magic	= RPCAUTH_CRED_MAGIC,
141 #endif
142 };
143