bridge: Allow tail-call on br_pass_frame_up
[linux-2.6.git] / 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         unsigned int groups = 0;
64         unsigned int i;
65
66         dprintk("RPC:       allocating UNIX cred for uid %d gid %d\n",
67                         acred->uid, acred->gid);
68
69         if (!(cred = kmalloc(sizeof(*cred), GFP_NOFS)))
70                 return ERR_PTR(-ENOMEM);
71
72         rpcauth_init_cred(&cred->uc_base, acred, auth, &unix_credops);
73         cred->uc_base.cr_flags = 1UL << RPCAUTH_CRED_UPTODATE;
74
75         if (acred->group_info != NULL)
76                 groups = acred->group_info->ngroups;
77         if (groups > NFS_NGROUPS)
78                 groups = NFS_NGROUPS;
79
80         cred->uc_gid = acred->gid;
81         for (i = 0; i < groups; i++)
82                 cred->uc_gids[i] = GROUP_AT(acred->group_info, i);
83         if (i < NFS_NGROUPS)
84                 cred->uc_gids[i] = NOGROUP;
85
86         return &cred->uc_base;
87 }
88
89 static void
90 unx_free_cred(struct unx_cred *unx_cred)
91 {
92         dprintk("RPC:       unx_free_cred %p\n", unx_cred);
93         kfree(unx_cred);
94 }
95
96 static void
97 unx_free_cred_callback(struct rcu_head *head)
98 {
99         struct unx_cred *unx_cred = container_of(head, struct unx_cred, uc_base.cr_rcu);
100         unx_free_cred(unx_cred);
101 }
102
103 static void
104 unx_destroy_cred(struct rpc_cred *cred)
105 {
106         call_rcu(&cred->cr_rcu, unx_free_cred_callback);
107 }
108
109 /*
110  * Match credentials against current process creds.
111  * The root_override argument takes care of cases where the caller may
112  * request root creds (e.g. for NFS swapping).
113  */
114 static int
115 unx_match(struct auth_cred *acred, struct rpc_cred *rcred, int flags)
116 {
117         struct unx_cred *cred = container_of(rcred, struct unx_cred, uc_base);
118         unsigned int groups = 0;
119         unsigned int i;
120
121
122         if (cred->uc_uid != acred->uid || cred->uc_gid != acred->gid)
123                 return 0;
124
125         if (acred->group_info != NULL)
126                 groups = acred->group_info->ngroups;
127         if (groups > NFS_NGROUPS)
128                 groups = NFS_NGROUPS;
129         for (i = 0; i < groups ; i++)
130                 if (cred->uc_gids[i] != GROUP_AT(acred->group_info, i))
131                         return 0;
132         return 1;
133 }
134
135 /*
136  * Marshal credentials.
137  * Maybe we should keep a cached credential for performance reasons.
138  */
139 static __be32 *
140 unx_marshal(struct rpc_task *task, __be32 *p)
141 {
142         struct rpc_clnt *clnt = task->tk_client;
143         struct unx_cred *cred = container_of(task->tk_msg.rpc_cred, struct unx_cred, uc_base);
144         __be32          *base, *hold;
145         int             i;
146
147         *p++ = htonl(RPC_AUTH_UNIX);
148         base = p++;
149         *p++ = htonl(jiffies/HZ);
150
151         /*
152          * Copy the UTS nodename captured when the client was created.
153          */
154         p = xdr_encode_array(p, clnt->cl_nodename, clnt->cl_nodelen);
155
156         *p++ = htonl((u32) cred->uc_uid);
157         *p++ = htonl((u32) cred->uc_gid);
158         hold = p++;
159         for (i = 0; i < 16 && cred->uc_gids[i] != (gid_t) NOGROUP; i++)
160                 *p++ = htonl((u32) cred->uc_gids[i]);
161         *hold = htonl(p - hold - 1);            /* gid array length */
162         *base = htonl((p - base - 1) << 2);     /* cred length */
163
164         *p++ = htonl(RPC_AUTH_NULL);
165         *p++ = htonl(0);
166
167         return p;
168 }
169
170 /*
171  * Refresh credentials. This is a no-op for AUTH_UNIX
172  */
173 static int
174 unx_refresh(struct rpc_task *task)
175 {
176         set_bit(RPCAUTH_CRED_UPTODATE, &task->tk_msg.rpc_cred->cr_flags);
177         return 0;
178 }
179
180 static __be32 *
181 unx_validate(struct rpc_task *task, __be32 *p)
182 {
183         rpc_authflavor_t        flavor;
184         u32                     size;
185
186         flavor = ntohl(*p++);
187         if (flavor != RPC_AUTH_NULL &&
188             flavor != RPC_AUTH_UNIX &&
189             flavor != RPC_AUTH_SHORT) {
190                 printk("RPC: bad verf flavor: %u\n", flavor);
191                 return NULL;
192         }
193
194         size = ntohl(*p++);
195         if (size > RPC_MAX_AUTH_SIZE) {
196                 printk("RPC: giant verf size: %u\n", size);
197                 return NULL;
198         }
199         task->tk_msg.rpc_cred->cr_auth->au_rslack = (size >> 2) + 2;
200         p += (size >> 2);
201
202         return p;
203 }
204
205 void __init rpc_init_authunix(void)
206 {
207         spin_lock_init(&unix_cred_cache.lock);
208 }
209
210 const struct rpc_authops authunix_ops = {
211         .owner          = THIS_MODULE,
212         .au_flavor      = RPC_AUTH_UNIX,
213         .au_name        = "UNIX",
214         .create         = unx_create,
215         .destroy        = unx_destroy,
216         .lookup_cred    = unx_lookup_cred,
217         .crcreate       = unx_create_cred,
218 };
219
220 static
221 struct rpc_cred_cache   unix_cred_cache = {
222 };
223
224 static
225 struct rpc_auth         unix_auth = {
226         .au_cslack      = UNX_WRITESLACK,
227         .au_rslack      = 2,                    /* assume AUTH_NULL verf */
228         .au_ops         = &authunix_ops,
229         .au_flavor      = RPC_AUTH_UNIX,
230         .au_count       = ATOMIC_INIT(0),
231         .au_credcache   = &unix_cred_cache,
232 };
233
234 static
235 const struct rpc_credops unix_credops = {
236         .cr_name        = "AUTH_UNIX",
237         .crdestroy      = unx_destroy_cred,
238         .crbind         = rpcauth_generic_bind_cred,
239         .crmatch        = unx_match,
240         .crmarshal      = unx_marshal,
241         .crrefresh      = unx_refresh,
242         .crvalidate     = unx_validate,
243 };