Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc
[linux-2.6] / net / sunrpc / auth_unix.c
1 /*
2  * linux/net/sunrpc/auth_unix.c
3  *
4  * UNIX-style authentication; no AUTH_SHORT support
5  *
6  * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
7  */
8
9 #include <linux/types.h>
10 #include <linux/sched.h>
11 #include <linux/module.h>
12 #include <linux/sunrpc/clnt.h>
13 #include <linux/sunrpc/auth.h>
14
15 #define NFS_NGROUPS     16
16
17 struct unx_cred {
18         struct rpc_cred         uc_base;
19         gid_t                   uc_gid;
20         gid_t                   uc_gids[NFS_NGROUPS];
21 };
22 #define uc_uid                  uc_base.cr_uid
23
24 #define UNX_WRITESLACK          (21 + (UNX_MAXNODENAME >> 2))
25
26 #ifdef RPC_DEBUG
27 # define RPCDBG_FACILITY        RPCDBG_AUTH
28 #endif
29
30 static struct rpc_auth          unix_auth;
31 static struct rpc_cred_cache    unix_cred_cache;
32 static const struct rpc_credops unix_credops;
33
34 static struct rpc_auth *
35 unx_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
36 {
37         dprintk("RPC:       creating UNIX authenticator for client %p\n",
38                         clnt);
39         atomic_inc(&unix_auth.au_count);
40         return &unix_auth;
41 }
42
43 static void
44 unx_destroy(struct rpc_auth *auth)
45 {
46         dprintk("RPC:       destroying UNIX authenticator %p\n", auth);
47         rpcauth_clear_credcache(auth->au_credcache);
48 }
49
50 /*
51  * Lookup AUTH_UNIX creds for current process
52  */
53 static struct rpc_cred *
54 unx_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
55 {
56         return rpcauth_lookup_credcache(auth, acred, flags);
57 }
58
59 static struct rpc_cred *
60 unx_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
61 {
62         struct unx_cred *cred;
63         int             i;
64
65         dprintk("RPC:       allocating UNIX cred for uid %d gid %d\n",
66                         acred->uid, acred->gid);
67
68         if (!(cred = kmalloc(sizeof(*cred), GFP_KERNEL)))
69                 return ERR_PTR(-ENOMEM);
70
71         rpcauth_init_cred(&cred->uc_base, acred, auth, &unix_credops);
72         cred->uc_base.cr_flags = 1UL << RPCAUTH_CRED_UPTODATE;
73         if (flags & RPCAUTH_LOOKUP_ROOTCREDS) {
74                 cred->uc_uid = 0;
75                 cred->uc_gid = 0;
76                 cred->uc_gids[0] = NOGROUP;
77         } else {
78                 int groups = acred->group_info->ngroups;
79                 if (groups > NFS_NGROUPS)
80                         groups = NFS_NGROUPS;
81
82                 cred->uc_gid = acred->gid;
83                 for (i = 0; i < groups; i++)
84                         cred->uc_gids[i] = GROUP_AT(acred->group_info, i);
85                 if (i < NFS_NGROUPS)
86                   cred->uc_gids[i] = NOGROUP;
87         }
88
89         return &cred->uc_base;
90 }
91
92 static void
93 unx_free_cred(struct unx_cred *unx_cred)
94 {
95         dprintk("RPC:       unx_free_cred %p\n", unx_cred);
96         kfree(unx_cred);
97 }
98
99 static void
100 unx_free_cred_callback(struct rcu_head *head)
101 {
102         struct unx_cred *unx_cred = container_of(head, struct unx_cred, uc_base.cr_rcu);
103         unx_free_cred(unx_cred);
104 }
105
106 static void
107 unx_destroy_cred(struct rpc_cred *cred)
108 {
109         call_rcu(&cred->cr_rcu, unx_free_cred_callback);
110 }
111
112 /*
113  * Match credentials against current process creds.
114  * The root_override argument takes care of cases where the caller may
115  * request root creds (e.g. for NFS swapping).
116  */
117 static int
118 unx_match(struct auth_cred *acred, struct rpc_cred *rcred, int flags)
119 {
120         struct unx_cred *cred = container_of(rcred, struct unx_cred, uc_base);
121         int             i;
122
123         if (!(flags & RPCAUTH_LOOKUP_ROOTCREDS)) {
124                 int groups;
125
126                 if (cred->uc_uid != acred->uid
127                  || cred->uc_gid != acred->gid)
128                         return 0;
129
130                 groups = acred->group_info->ngroups;
131                 if (groups > NFS_NGROUPS)
132                         groups = NFS_NGROUPS;
133                 for (i = 0; i < groups ; i++)
134                         if (cred->uc_gids[i] != GROUP_AT(acred->group_info, i))
135                                 return 0;
136                 return 1;
137         }
138         return (cred->uc_uid == 0
139              && cred->uc_gid == 0
140              && cred->uc_gids[0] == (gid_t) NOGROUP);
141 }
142
143 /*
144  * Marshal credentials.
145  * Maybe we should keep a cached credential for performance reasons.
146  */
147 static __be32 *
148 unx_marshal(struct rpc_task *task, __be32 *p)
149 {
150         struct rpc_clnt *clnt = task->tk_client;
151         struct unx_cred *cred = container_of(task->tk_msg.rpc_cred, struct unx_cred, uc_base);
152         __be32          *base, *hold;
153         int             i;
154
155         *p++ = htonl(RPC_AUTH_UNIX);
156         base = p++;
157         *p++ = htonl(jiffies/HZ);
158
159         /*
160          * Copy the UTS nodename captured when the client was created.
161          */
162         p = xdr_encode_array(p, clnt->cl_nodename, clnt->cl_nodelen);
163
164         *p++ = htonl((u32) cred->uc_uid);
165         *p++ = htonl((u32) cred->uc_gid);
166         hold = p++;
167         for (i = 0; i < 16 && cred->uc_gids[i] != (gid_t) NOGROUP; i++)
168                 *p++ = htonl((u32) cred->uc_gids[i]);
169         *hold = htonl(p - hold - 1);            /* gid array length */
170         *base = htonl((p - base - 1) << 2);     /* cred length */
171
172         *p++ = htonl(RPC_AUTH_NULL);
173         *p++ = htonl(0);
174
175         return p;
176 }
177
178 /*
179  * Refresh credentials. This is a no-op for AUTH_UNIX
180  */
181 static int
182 unx_refresh(struct rpc_task *task)
183 {
184         set_bit(RPCAUTH_CRED_UPTODATE, &task->tk_msg.rpc_cred->cr_flags);
185         return 0;
186 }
187
188 static __be32 *
189 unx_validate(struct rpc_task *task, __be32 *p)
190 {
191         rpc_authflavor_t        flavor;
192         u32                     size;
193
194         flavor = ntohl(*p++);
195         if (flavor != RPC_AUTH_NULL &&
196             flavor != RPC_AUTH_UNIX &&
197             flavor != RPC_AUTH_SHORT) {
198                 printk("RPC: bad verf flavor: %u\n", flavor);
199                 return NULL;
200         }
201
202         size = ntohl(*p++);
203         if (size > RPC_MAX_AUTH_SIZE) {
204                 printk("RPC: giant verf size: %u\n", size);
205                 return NULL;
206         }
207         task->tk_msg.rpc_cred->cr_auth->au_rslack = (size >> 2) + 2;
208         p += (size >> 2);
209
210         return p;
211 }
212
213 void __init rpc_init_authunix(void)
214 {
215         spin_lock_init(&unix_cred_cache.lock);
216 }
217
218 const struct rpc_authops authunix_ops = {
219         .owner          = THIS_MODULE,
220         .au_flavor      = RPC_AUTH_UNIX,
221 #ifdef RPC_DEBUG
222         .au_name        = "UNIX",
223 #endif
224         .create         = unx_create,
225         .destroy        = unx_destroy,
226         .lookup_cred    = unx_lookup_cred,
227         .crcreate       = unx_create_cred,
228 };
229
230 static
231 struct rpc_cred_cache   unix_cred_cache = {
232 };
233
234 static
235 struct rpc_auth         unix_auth = {
236         .au_cslack      = UNX_WRITESLACK,
237         .au_rslack      = 2,                    /* assume AUTH_NULL verf */
238         .au_ops         = &authunix_ops,
239         .au_flavor      = RPC_AUTH_UNIX,
240         .au_count       = ATOMIC_INIT(0),
241         .au_credcache   = &unix_cred_cache,
242 };
243
244 static
245 const struct rpc_credops unix_credops = {
246         .cr_name        = "AUTH_UNIX",
247         .crdestroy      = unx_destroy_cred,
248         .crmatch        = unx_match,
249         .crmarshal      = unx_marshal,
250         .crrefresh      = unx_refresh,
251         .crvalidate     = unx_validate,
252 };