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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
Tejun Heo5a0e3ad2010-03-24 17:04:11 +09009#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070010#include <linux/types.h>
11#include <linux/sched.h>
12#include <linux/module.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070013#include <linux/sunrpc/clnt.h>
14#include <linux/sunrpc/auth.h>
15
16#define NFS_NGROUPS 16
17
18struct unx_cred {
19 struct rpc_cred uc_base;
20 gid_t uc_gid;
21 gid_t uc_gids[NFS_NGROUPS];
22};
23#define uc_uid uc_base.cr_uid
Linus Torvalds1da177e2005-04-16 15:20:36 -070024
Linus Torvalds1da177e2005-04-16 15:20:36 -070025#define UNX_WRITESLACK (21 + (UNX_MAXNODENAME >> 2))
26
27#ifdef RPC_DEBUG
28# define RPCDBG_FACILITY RPCDBG_AUTH
29#endif
30
31static struct rpc_auth unix_auth;
Trond Myklebustf1c0a862007-06-23 20:17:58 -040032static const struct rpc_credops unix_credops;
Linus Torvalds1da177e2005-04-16 15:20:36 -070033
34static struct rpc_auth *
35unx_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
36{
Chuck Lever46121cf2007-01-31 12:14:08 -050037 dprintk("RPC: creating UNIX authenticator for client %p\n",
38 clnt);
Trond Myklebustf5c21872007-06-25 17:11:20 -040039 atomic_inc(&unix_auth.au_count);
Linus Torvalds1da177e2005-04-16 15:20:36 -070040 return &unix_auth;
41}
42
43static void
44unx_destroy(struct rpc_auth *auth)
45{
Chuck Lever46121cf2007-01-31 12:14:08 -050046 dprintk("RPC: destroying UNIX authenticator %p\n", auth);
Trond Myklebust3ab9bb72007-06-09 15:41:42 -040047 rpcauth_clear_credcache(auth->au_credcache);
Linus Torvalds1da177e2005-04-16 15:20:36 -070048}
49
50/*
51 * Lookup AUTH_UNIX creds for current process
52 */
53static struct rpc_cred *
54unx_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
55{
56 return rpcauth_lookup_credcache(auth, acred, flags);
57}
58
59static struct rpc_cred *
60unx_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
61{
62 struct unx_cred *cred;
Trond Myklebustaf093832008-03-12 12:12:16 -040063 unsigned int groups = 0;
64 unsigned int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -070065
Chuck Lever46121cf2007-01-31 12:14:08 -050066 dprintk("RPC: allocating UNIX cred for uid %d gid %d\n",
67 acred->uid, acred->gid);
Linus Torvalds1da177e2005-04-16 15:20:36 -070068
Trond Myklebust0f38b872008-06-10 18:31:01 -040069 if (!(cred = kmalloc(sizeof(*cred), GFP_NOFS)))
Linus Torvalds1da177e2005-04-16 15:20:36 -070070 return ERR_PTR(-ENOMEM);
71
Trond Myklebust5fe47552007-06-23 19:55:31 -040072 rpcauth_init_cred(&cred->uc_base, acred, auth, &unix_credops);
Trond Myklebustfc432dd2007-06-25 10:15:15 -040073 cred->uc_base.cr_flags = 1UL << RPCAUTH_CRED_UPTODATE;
Linus Torvalds1da177e2005-04-16 15:20:36 -070074
Trond Myklebustaf093832008-03-12 12:12:16 -040075 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;
Linus Torvalds1da177e2005-04-16 15:20:36 -070085
Trond Myklebust696e38d2007-06-25 09:48:25 -040086 return &cred->uc_base;
Linus Torvalds1da177e2005-04-16 15:20:36 -070087}
88
89static void
Trond Myklebust31be5bf2007-06-24 15:55:26 -040090unx_free_cred(struct unx_cred *unx_cred)
Linus Torvalds1da177e2005-04-16 15:20:36 -070091{
Trond Myklebust31be5bf2007-06-24 15:55:26 -040092 dprintk("RPC: unx_free_cred %p\n", unx_cred);
93 kfree(unx_cred);
94}
Trond Myklebust696e38d2007-06-25 09:48:25 -040095
Trond Myklebust31be5bf2007-06-24 15:55:26 -040096static void
97unx_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
103static void
104unx_destroy_cred(struct rpc_cred *cred)
105{
106 call_rcu(&cred->cr_rcu, unx_free_cred_callback);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107}
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 */
114static int
Trond Myklebust8a317762006-02-01 12:18:36 -0500115unx_match(struct auth_cred *acred, struct rpc_cred *rcred, int flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116{
Trond Myklebust696e38d2007-06-25 09:48:25 -0400117 struct unx_cred *cred = container_of(rcred, struct unx_cred, uc_base);
Trond Myklebustaf093832008-03-12 12:12:16 -0400118 unsigned int groups = 0;
119 unsigned int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121
Trond Myklebustaf093832008-03-12 12:12:16 -0400122 if (cred->uc_uid != acred->uid || cred->uc_gid != acred->gid)
123 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124
Trond Myklebustaf093832008-03-12 12:12:16 -0400125 if (acred->group_info != NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126 groups = acred->group_info->ngroups;
Trond Myklebustaf093832008-03-12 12:12:16 -0400127 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;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133}
134
135/*
136 * Marshal credentials.
137 * Maybe we should keep a cached credential for performance reasons.
138 */
Alexey Dobriyand8ed0292006-09-26 22:29:38 -0700139static __be32 *
140unx_marshal(struct rpc_task *task, __be32 *p)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141{
142 struct rpc_clnt *clnt = task->tk_client;
Trond Myklebusta17c2152010-07-31 14:29:08 -0400143 struct unx_cred *cred = container_of(task->tk_rqstp->rq_cred, struct unx_cred, uc_base);
Alexey Dobriyand8ed0292006-09-26 22:29:38 -0700144 __be32 *base, *hold;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145 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 */
173static int
174unx_refresh(struct rpc_task *task)
175{
Trond Myklebusta17c2152010-07-31 14:29:08 -0400176 set_bit(RPCAUTH_CRED_UPTODATE, &task->tk_rqstp->rq_cred->cr_flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177 return 0;
178}
179
Alexey Dobriyand8ed0292006-09-26 22:29:38 -0700180static __be32 *
181unx_validate(struct rpc_task *task, __be32 *p)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182{
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 }
Trond Myklebusta17c2152010-07-31 14:29:08 -0400199 task->tk_rqstp->rq_cred->cr_auth->au_rslack = (size >> 2) + 2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200 p += (size >> 2);
201
202 return p;
203}
204
Trond Myklebust5d8d9a42010-07-31 14:29:07 -0400205int __init rpc_init_authunix(void)
Trond Myklebust9499b432007-06-24 15:57:57 -0400206{
Trond Myklebust5d8d9a42010-07-31 14:29:07 -0400207 return rpcauth_init_credcache(&unix_auth);
208}
209
210void rpc_destroy_authunix(void)
211{
212 rpcauth_destroy_credcache(&unix_auth);
Trond Myklebust9499b432007-06-24 15:57:57 -0400213}
214
Trond Myklebustf1c0a862007-06-23 20:17:58 -0400215const struct rpc_authops authunix_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216 .owner = THIS_MODULE,
217 .au_flavor = RPC_AUTH_UNIX,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 .au_name = "UNIX",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219 .create = unx_create,
220 .destroy = unx_destroy,
221 .lookup_cred = unx_lookup_cred,
222 .crcreate = unx_create_cred,
223};
224
225static
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226struct rpc_auth unix_auth = {
227 .au_cslack = UNX_WRITESLACK,
228 .au_rslack = 2, /* assume AUTH_NULL verf */
229 .au_ops = &authunix_ops,
Trond Myklebust81039f12006-06-09 09:34:34 -0400230 .au_flavor = RPC_AUTH_UNIX,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 .au_count = ATOMIC_INIT(0),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232};
233
234static
Trond Myklebustf1c0a862007-06-23 20:17:58 -0400235const struct rpc_credops unix_credops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236 .cr_name = "AUTH_UNIX",
237 .crdestroy = unx_destroy_cred,
Trond Myklebust5c691042008-03-12 16:21:07 -0400238 .crbind = rpcauth_generic_bind_cred,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239 .crmatch = unx_match,
240 .crmarshal = unx_marshal,
241 .crrefresh = unx_refresh,
242 .crvalidate = unx_validate,
243};