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(const char * service_name)44 struct rpc_cred *rpc_lookup_machine_cred(const char *service_name)
45 {
46 struct auth_cred acred = {
47 .uid = RPC_MACHINE_CRED_USERID,
48 .gid = RPC_MACHINE_CRED_GROUPID,
49 .principal = service_name,
50 .machine_cred = 1,
51 };
52
53 dprintk("RPC: looking up machine cred for service %s\n",
54 service_name);
55 return generic_auth.au_ops->lookup_cred(&generic_auth, &acred, 0);
56 }
57 EXPORT_SYMBOL_GPL(rpc_lookup_machine_cred);
58
generic_bind_cred(struct rpc_task * task,struct rpc_cred * cred,int lookupflags)59 static struct rpc_cred *generic_bind_cred(struct rpc_task *task,
60 struct rpc_cred *cred, int lookupflags)
61 {
62 struct rpc_auth *auth = task->tk_client->cl_auth;
63 struct auth_cred *acred = &container_of(cred, struct generic_cred, gc_base)->acred;
64
65 return auth->au_ops->lookup_cred(auth, acred, lookupflags);
66 }
67
68 /*
69 * Lookup generic creds for current process
70 */
71 static struct rpc_cred *
generic_lookup_cred(struct rpc_auth * auth,struct auth_cred * acred,int flags)72 generic_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
73 {
74 return rpcauth_lookup_credcache(&generic_auth, acred, flags);
75 }
76
77 static struct rpc_cred *
generic_create_cred(struct rpc_auth * auth,struct auth_cred * acred,int flags)78 generic_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
79 {
80 struct generic_cred *gcred;
81
82 gcred = kmalloc(sizeof(*gcred), GFP_KERNEL);
83 if (gcred == NULL)
84 return ERR_PTR(-ENOMEM);
85
86 rpcauth_init_cred(&gcred->gc_base, acred, &generic_auth, &generic_credops);
87 gcred->gc_base.cr_flags = 1UL << RPCAUTH_CRED_UPTODATE;
88
89 gcred->acred.uid = acred->uid;
90 gcred->acred.gid = acred->gid;
91 gcred->acred.group_info = acred->group_info;
92 if (gcred->acred.group_info != NULL)
93 get_group_info(gcred->acred.group_info);
94 gcred->acred.machine_cred = acred->machine_cred;
95 gcred->acred.principal = acred->principal;
96
97 dprintk("RPC: allocated %s cred %p for uid %d gid %d\n",
98 gcred->acred.machine_cred ? "machine" : "generic",
99 gcred, acred->uid, acred->gid);
100 return &gcred->gc_base;
101 }
102
103 static void
generic_free_cred(struct rpc_cred * cred)104 generic_free_cred(struct rpc_cred *cred)
105 {
106 struct generic_cred *gcred = container_of(cred, struct generic_cred, gc_base);
107
108 dprintk("RPC: generic_free_cred %p\n", gcred);
109 if (gcred->acred.group_info != NULL)
110 put_group_info(gcred->acred.group_info);
111 kfree(gcred);
112 }
113
114 static void
generic_free_cred_callback(struct rcu_head * head)115 generic_free_cred_callback(struct rcu_head *head)
116 {
117 struct rpc_cred *cred = container_of(head, struct rpc_cred, cr_rcu);
118 generic_free_cred(cred);
119 }
120
121 static void
generic_destroy_cred(struct rpc_cred * cred)122 generic_destroy_cred(struct rpc_cred *cred)
123 {
124 call_rcu(&cred->cr_rcu, generic_free_cred_callback);
125 }
126
127 static int
machine_cred_match(struct auth_cred * acred,struct generic_cred * gcred,int flags)128 machine_cred_match(struct auth_cred *acred, struct generic_cred *gcred, int flags)
129 {
130 if (!gcred->acred.machine_cred ||
131 gcred->acred.principal != acred->principal ||
132 gcred->acred.uid != acred->uid ||
133 gcred->acred.gid != acred->gid)
134 return 0;
135 return 1;
136 }
137
138 /*
139 * Match credentials against current process creds.
140 */
141 static int
generic_match(struct auth_cred * acred,struct rpc_cred * cred,int flags)142 generic_match(struct auth_cred *acred, struct rpc_cred *cred, int flags)
143 {
144 struct generic_cred *gcred = container_of(cred, struct generic_cred, gc_base);
145 int i;
146
147 if (acred->machine_cred)
148 return machine_cred_match(acred, gcred, flags);
149
150 if (gcred->acred.uid != acred->uid ||
151 gcred->acred.gid != acred->gid ||
152 gcred->acred.machine_cred != 0)
153 goto out_nomatch;
154
155 /* Optimisation in the case where pointers are identical... */
156 if (gcred->acred.group_info == acred->group_info)
157 goto out_match;
158
159 /* Slow path... */
160 if (gcred->acred.group_info->ngroups != acred->group_info->ngroups)
161 goto out_nomatch;
162 for (i = 0; i < gcred->acred.group_info->ngroups; i++) {
163 if (GROUP_AT(gcred->acred.group_info, i) !=
164 GROUP_AT(acred->group_info, i))
165 goto out_nomatch;
166 }
167 out_match:
168 return 1;
169 out_nomatch:
170 return 0;
171 }
172
rpc_init_generic_auth(void)173 int __init rpc_init_generic_auth(void)
174 {
175 return rpcauth_init_credcache(&generic_auth);
176 }
177
rpc_destroy_generic_auth(void)178 void rpc_destroy_generic_auth(void)
179 {
180 rpcauth_destroy_credcache(&generic_auth);
181 }
182
183 static const struct rpc_authops generic_auth_ops = {
184 .owner = THIS_MODULE,
185 .au_name = "Generic",
186 .lookup_cred = generic_lookup_cred,
187 .crcreate = generic_create_cred,
188 };
189
190 static struct rpc_auth generic_auth = {
191 .au_ops = &generic_auth_ops,
192 .au_count = ATOMIC_INIT(0),
193 };
194
195 static const struct rpc_credops generic_credops = {
196 .cr_name = "Generic cred",
197 .crdestroy = generic_destroy_cred,
198 .crbind = generic_bind_cred,
199 .crmatch = generic_match,
200 };
201