Decompressors: check input size in decompress_unlzo.c
[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/slab.h>
9 #include <linux/types.h>
10 #include <linux/module.h>
11 #include <linux/sched.h>
12 #include <linux/sunrpc/auth.h>
13 #include <linux/sunrpc/clnt.h>
14 #include <linux/sunrpc/debug.h>
15 #include <linux/sunrpc/sched.h>
16
17 #ifdef RPC_DEBUG
18 # define RPCDBG_FACILITY        RPCDBG_AUTH
19 #endif
20
21 #define RPC_MACHINE_CRED_USERID         ((uid_t)0)
22 #define RPC_MACHINE_CRED_GROUPID        ((gid_t)0)
23
24 struct generic_cred {
25         struct rpc_cred gc_base;
26         struct auth_cred acred;
27 };
28
29 static struct rpc_auth generic_auth;
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 struct rpc_cred *generic_bind_cred(struct rpc_task *task,
58                 struct rpc_cred *cred, int lookupflags)
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
63         return auth->au_ops->lookup_cred(auth, acred, lookupflags);
64 }
65
66 /*
67  * Lookup generic creds for current process
68  */
69 static struct rpc_cred *
70 generic_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
71 {
72         return rpcauth_lookup_credcache(&generic_auth, acred, flags);
73 }
74
75 static struct rpc_cred *
76 generic_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
77 {
78         struct generic_cred *gcred;
79
80         gcred = kmalloc(sizeof(*gcred), GFP_KERNEL);
81         if (gcred == NULL)
82                 return ERR_PTR(-ENOMEM);
83
84         rpcauth_init_cred(&gcred->gc_base, acred, &generic_auth, &generic_credops);
85         gcred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_UPTODATE;
86
87         gcred->acred.uid = acred->uid;
88         gcred->acred.gid = acred->gid;
89         gcred->acred.group_info = acred->group_info;
90         if (gcred->acred.group_info != NULL)
91                 get_group_info(gcred->acred.group_info);
92         gcred->acred.machine_cred = acred->machine_cred;
93
94         dprintk("RPC:       allocated %s cred %p for uid %d gid %d\n",
95                         gcred->acred.machine_cred ? "machine" : "generic",
96                         gcred, acred->uid, acred->gid);
97         return &gcred->gc_base;
98 }
99
100 static void
101 generic_free_cred(struct rpc_cred *cred)
102 {
103         struct generic_cred *gcred = container_of(cred, struct generic_cred, gc_base);
104
105         dprintk("RPC:       generic_free_cred %p\n", gcred);
106         if (gcred->acred.group_info != NULL)
107                 put_group_info(gcred->acred.group_info);
108         kfree(gcred);
109 }
110
111 static void
112 generic_free_cred_callback(struct rcu_head *head)
113 {
114         struct rpc_cred *cred = container_of(head, struct rpc_cred, cr_rcu);
115         generic_free_cred(cred);
116 }
117
118 static void
119 generic_destroy_cred(struct rpc_cred *cred)
120 {
121         call_rcu(&cred->cr_rcu, generic_free_cred_callback);
122 }
123
124 /*
125  * Match credentials against current process creds.
126  */
127 static int
128 generic_match(struct auth_cred *acred, struct rpc_cred *cred, int flags)
129 {
130         struct generic_cred *gcred = container_of(cred, struct generic_cred, gc_base);
131         int i;
132
133         if (gcred->acred.uid != acred->uid ||
134             gcred->acred.gid != acred->gid ||
135             gcred->acred.machine_cred != acred->machine_cred)
136                 goto out_nomatch;
137
138         /* Optimisation in the case where pointers are identical... */
139         if (gcred->acred.group_info == acred->group_info)
140                 goto out_match;
141
142         /* Slow path... */
143         if (gcred->acred.group_info->ngroups != acred->group_info->ngroups)
144                 goto out_nomatch;
145         for (i = 0; i < gcred->acred.group_info->ngroups; i++) {
146                 if (GROUP_AT(gcred->acred.group_info, i) !=
147                                 GROUP_AT(acred->group_info, i))
148                         goto out_nomatch;
149         }
150 out_match:
151         return 1;
152 out_nomatch:
153         return 0;
154 }
155
156 int __init rpc_init_generic_auth(void)
157 {
158         return rpcauth_init_credcache(&generic_auth);
159 }
160
161 void rpc_destroy_generic_auth(void)
162 {
163         rpcauth_destroy_credcache(&generic_auth);
164 }
165
166 static const struct rpc_authops generic_auth_ops = {
167         .owner = THIS_MODULE,
168         .au_name = "Generic",
169         .lookup_cred = generic_lookup_cred,
170         .crcreate = generic_create_cred,
171 };
172
173 static struct rpc_auth generic_auth = {
174         .au_ops = &generic_auth_ops,
175         .au_count = ATOMIC_INIT(0),
176 };
177
178 static const struct rpc_credops generic_credops = {
179         .cr_name = "Generic cred",
180         .crdestroy = generic_destroy_cred,
181         .crbind = generic_bind_cred,
182         .crmatch = generic_match,
183 };