4028502f052858b1d66af4b31c17d641c16fac0b
[linux-2.6.git] / net / sunrpc / auth_generic.c
1 /*
2  * Generic RPC credential
3  *
4  * Copyright (C) 2008, Trond Myklebust <Trond.Myklebust@netapp.com>
5  */
6
7 #include <linux/err.h>
8 #include <linux/types.h>
9 #include <linux/module.h>
10 #include <linux/sched.h>
11 #include <linux/sunrpc/auth.h>
12 #include <linux/sunrpc/clnt.h>
13 #include <linux/sunrpc/debug.h>
14 #include <linux/sunrpc/sched.h>
15
16 #ifdef RPC_DEBUG
17 # define RPCDBG_FACILITY        RPCDBG_AUTH
18 #endif
19
20 #define RPC_MACHINE_CRED_USERID         ((uid_t)0)
21 #define RPC_MACHINE_CRED_GROUPID        ((gid_t)0)
22
23 struct generic_cred {
24         struct rpc_cred gc_base;
25         struct auth_cred acred;
26 };
27
28 static struct rpc_auth generic_auth;
29 static struct rpc_cred_cache generic_cred_cache;
30 static const struct rpc_credops generic_credops;
31
32 /*
33  * Public call interface
34  */
35 struct rpc_cred *rpc_lookup_cred(void)
36 {
37         return rpcauth_lookupcred(&generic_auth, 0);
38 }
39 EXPORT_SYMBOL_GPL(rpc_lookup_cred);
40
41 /*
42  * Public call interface for looking up machine creds.
43  */
44 struct rpc_cred *rpc_lookup_machine_cred(void)
45 {
46         struct auth_cred acred = {
47                 .uid = RPC_MACHINE_CRED_USERID,
48                 .gid = RPC_MACHINE_CRED_GROUPID,
49                 .machine_cred = 1,
50         };
51
52         dprintk("RPC:       looking up machine cred\n");
53         return generic_auth.au_ops->lookup_cred(&generic_auth, &acred, 0);
54 }
55 EXPORT_SYMBOL_GPL(rpc_lookup_machine_cred);
56
57 static void
58 generic_bind_cred(struct rpc_task *task, struct rpc_cred *cred)
59 {
60         struct rpc_auth *auth = task->tk_client->cl_auth;
61         struct auth_cred *acred = &container_of(cred, struct generic_cred, gc_base)->acred;
62         struct rpc_cred *ret;
63
64         ret = auth->au_ops->lookup_cred(auth, acred, 0);
65         if (!IS_ERR(ret))
66                 task->tk_msg.rpc_cred = ret;
67         else
68                 task->tk_status = PTR_ERR(ret);
69 }
70
71 /*
72  * Lookup generic creds for current process
73  */
74 static struct rpc_cred *
75 generic_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
76 {
77         return rpcauth_lookup_credcache(&generic_auth, acred, flags);
78 }
79
80 static struct rpc_cred *
81 generic_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
82 {
83         struct generic_cred *gcred;
84
85         gcred = kmalloc(sizeof(*gcred), GFP_KERNEL);
86         if (gcred == NULL)
87                 return ERR_PTR(-ENOMEM);
88
89         rpcauth_init_cred(&gcred->gc_base, acred, &generic_auth, &generic_credops);
90         gcred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_UPTODATE;
91
92         gcred->acred.uid = acred->uid;
93         gcred->acred.gid = acred->gid;
94         gcred->acred.group_info = acred->group_info;
95         if (gcred->acred.group_info != NULL)
96                 get_group_info(gcred->acred.group_info);
97         gcred->acred.machine_cred = acred->machine_cred;
98
99         dprintk("RPC:       allocated %s cred %p for uid %d gid %d\n",
100                         gcred->acred.machine_cred ? "machine" : "generic",
101                         gcred, acred->uid, acred->gid);
102         return &gcred->gc_base;
103 }
104
105 static void
106 generic_free_cred(struct rpc_cred *cred)
107 {
108         struct generic_cred *gcred = container_of(cred, struct generic_cred, gc_base);
109
110         dprintk("RPC:       generic_free_cred %p\n", gcred);
111         if (gcred->acred.group_info != NULL)
112                 put_group_info(gcred->acred.group_info);
113         kfree(gcred);
114 }
115
116 static void
117 generic_free_cred_callback(struct rcu_head *head)
118 {
119         struct rpc_cred *cred = container_of(head, struct rpc_cred, cr_rcu);
120         generic_free_cred(cred);
121 }
122
123 static void
124 generic_destroy_cred(struct rpc_cred *cred)
125 {
126         call_rcu(&cred->cr_rcu, generic_free_cred_callback);
127 }
128
129 /*
130  * Match credentials against current process creds.
131  */
132 static int
133 generic_match(struct auth_cred *acred, struct rpc_cred *cred, int flags)
134 {
135         struct generic_cred *gcred = container_of(cred, struct generic_cred, gc_base);
136         int i;
137
138         if (gcred->acred.uid != acred->uid ||
139             gcred->acred.gid != acred->gid ||
140             gcred->acred.machine_cred != acred->machine_cred)
141                 goto out_nomatch;
142
143         /* Optimisation in the case where pointers are identical... */
144         if (gcred->acred.group_info == acred->group_info)
145                 goto out_match;
146
147         /* Slow path... */
148         if (gcred->acred.group_info->ngroups != acred->group_info->ngroups)
149                 goto out_nomatch;
150         for (i = 0; i < gcred->acred.group_info->ngroups; i++) {
151                 if (GROUP_AT(gcred->acred.group_info, i) !=
152                                 GROUP_AT(acred->group_info, i))
153                         goto out_nomatch;
154         }
155 out_match:
156         return 1;
157 out_nomatch:
158         return 0;
159 }
160
161 void __init rpc_init_generic_auth(void)
162 {
163         spin_lock_init(&generic_cred_cache.lock);
164 }
165
166 void __exit rpc_destroy_generic_auth(void)
167 {
168         rpcauth_clear_credcache(&generic_cred_cache);
169 }
170
171 static struct rpc_cred_cache generic_cred_cache = {
172         {{ NULL, },},
173 };
174
175 static const struct rpc_authops generic_auth_ops = {
176         .owner = THIS_MODULE,
177         .au_name = "Generic",
178         .lookup_cred = generic_lookup_cred,
179         .crcreate = generic_create_cred,
180 };
181
182 static struct rpc_auth generic_auth = {
183         .au_ops = &generic_auth_ops,
184         .au_count = ATOMIC_INIT(0),
185         .au_credcache = &generic_cred_cache,
186 };
187
188 static const struct rpc_credops generic_credops = {
189         .cr_name = "Generic cred",
190         .crdestroy = generic_destroy_cred,
191         .crbind = generic_bind_cred,
192         .crmatch = generic_match,
193 };