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 */
rpc_lookup_cred(void)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 */
rpc_lookup_machine_cred(void)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
generic_bind_cred(struct rpc_task * task,struct rpc_cred * cred,int lookupflags)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 *
generic_lookup_cred(struct rpc_auth * auth,struct auth_cred * acred,int flags)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 *
generic_create_cred(struct rpc_auth * auth,struct auth_cred * acred,int flags)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
generic_free_cred(struct rpc_cred * cred)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
generic_free_cred_callback(struct rcu_head * head)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
generic_destroy_cred(struct rpc_cred * cred)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
generic_match(struct auth_cred * acred,struct rpc_cred * cred,int flags)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
rpc_init_generic_auth(void)156 int __init rpc_init_generic_auth(void)
157 {
158 return rpcauth_init_credcache(&generic_auth);
159 }
160
rpc_destroy_generic_auth(void)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 };
184