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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>
Eric W. Biedermanae2975b2011-11-14 15:56:38 -080015#include <linux/user_namespace.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070016
17#define NFS_NGROUPS 16
18
19struct unx_cred {
20 struct rpc_cred uc_base;
21 gid_t uc_gid;
22 gid_t uc_gids[NFS_NGROUPS];
23};
24#define uc_uid uc_base.cr_uid
Linus Torvalds1da177e2005-04-16 15:20:36 -070025
Linus Torvalds1da177e2005-04-16 15:20:36 -070026#define UNX_WRITESLACK (21 + (UNX_MAXNODENAME >> 2))
27
28#ifdef RPC_DEBUG
29# define RPCDBG_FACILITY RPCDBG_AUTH
30#endif
31
32static struct rpc_auth unix_auth;
Trond Myklebustf1c0a862007-06-23 20:17:58 -040033static const struct rpc_credops unix_credops;
Linus Torvalds1da177e2005-04-16 15:20:36 -070034
35static struct rpc_auth *
36unx_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
37{
Chuck Lever46121cf2007-01-31 12:14:08 -050038 dprintk("RPC: creating UNIX authenticator for client %p\n",
39 clnt);
Trond Myklebustf5c21872007-06-25 17:11:20 -040040 atomic_inc(&unix_auth.au_count);
Linus Torvalds1da177e2005-04-16 15:20:36 -070041 return &unix_auth;
42}
43
44static void
45unx_destroy(struct rpc_auth *auth)
46{
Chuck Lever46121cf2007-01-31 12:14:08 -050047 dprintk("RPC: destroying UNIX authenticator %p\n", auth);
Trond Myklebust3ab9bb72007-06-09 15:41:42 -040048 rpcauth_clear_credcache(auth->au_credcache);
Linus Torvalds1da177e2005-04-16 15:20:36 -070049}
50
51/*
52 * Lookup AUTH_UNIX creds for current process
53 */
54static struct rpc_cred *
55unx_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
56{
57 return rpcauth_lookup_credcache(auth, acred, flags);
58}
59
60static struct rpc_cred *
61unx_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
62{
63 struct unx_cred *cred;
Trond Myklebustaf093832008-03-12 12:12:16 -040064 unsigned int groups = 0;
65 unsigned int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -070066
Chuck Lever46121cf2007-01-31 12:14:08 -050067 dprintk("RPC: allocating UNIX cred for uid %d gid %d\n",
68 acred->uid, acred->gid);
Linus Torvalds1da177e2005-04-16 15:20:36 -070069
Trond Myklebust0f38b872008-06-10 18:31:01 -040070 if (!(cred = kmalloc(sizeof(*cred), GFP_NOFS)))
Linus Torvalds1da177e2005-04-16 15:20:36 -070071 return ERR_PTR(-ENOMEM);
72
Trond Myklebust5fe47552007-06-23 19:55:31 -040073 rpcauth_init_cred(&cred->uc_base, acred, auth, &unix_credops);
Trond Myklebustfc432dd2007-06-25 10:15:15 -040074 cred->uc_base.cr_flags = 1UL << RPCAUTH_CRED_UPTODATE;
Linus Torvalds1da177e2005-04-16 15:20:36 -070075
Trond Myklebustaf093832008-03-12 12:12:16 -040076 if (acred->group_info != NULL)
77 groups = acred->group_info->ngroups;
78 if (groups > NFS_NGROUPS)
79 groups = NFS_NGROUPS;
80
81 cred->uc_gid = acred->gid;
Eric W. Biedermanae2975b2011-11-14 15:56:38 -080082 for (i = 0; i < groups; i++) {
83 gid_t gid;
84 gid = from_kgid(&init_user_ns, GROUP_AT(acred->group_info, i));
85 cred->uc_gids[i] = gid;
86 }
Trond Myklebustaf093832008-03-12 12:12:16 -040087 if (i < NFS_NGROUPS)
88 cred->uc_gids[i] = NOGROUP;
Linus Torvalds1da177e2005-04-16 15:20:36 -070089
Trond Myklebust696e38d2007-06-25 09:48:25 -040090 return &cred->uc_base;
Linus Torvalds1da177e2005-04-16 15:20:36 -070091}
92
93static void
Trond Myklebust31be5bf2007-06-24 15:55:26 -040094unx_free_cred(struct unx_cred *unx_cred)
Linus Torvalds1da177e2005-04-16 15:20:36 -070095{
Trond Myklebust31be5bf2007-06-24 15:55:26 -040096 dprintk("RPC: unx_free_cred %p\n", unx_cred);
97 kfree(unx_cred);
98}
Trond Myklebust696e38d2007-06-25 09:48:25 -040099
Trond Myklebust31be5bf2007-06-24 15:55:26 -0400100static void
101unx_free_cred_callback(struct rcu_head *head)
102{
103 struct unx_cred *unx_cred = container_of(head, struct unx_cred, uc_base.cr_rcu);
104 unx_free_cred(unx_cred);
105}
106
107static void
108unx_destroy_cred(struct rpc_cred *cred)
109{
110 call_rcu(&cred->cr_rcu, unx_free_cred_callback);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111}
112
113/*
114 * Match credentials against current process creds.
115 * The root_override argument takes care of cases where the caller may
116 * request root creds (e.g. for NFS swapping).
117 */
118static int
Trond Myklebust8a317762006-02-01 12:18:36 -0500119unx_match(struct auth_cred *acred, struct rpc_cred *rcred, int flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120{
Trond Myklebust696e38d2007-06-25 09:48:25 -0400121 struct unx_cred *cred = container_of(rcred, struct unx_cred, uc_base);
Trond Myklebustaf093832008-03-12 12:12:16 -0400122 unsigned int groups = 0;
123 unsigned int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125
Trond Myklebustaf093832008-03-12 12:12:16 -0400126 if (cred->uc_uid != acred->uid || cred->uc_gid != acred->gid)
127 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128
Trond Myklebustaf093832008-03-12 12:12:16 -0400129 if (acred->group_info != NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130 groups = acred->group_info->ngroups;
Trond Myklebustaf093832008-03-12 12:12:16 -0400131 if (groups > NFS_NGROUPS)
132 groups = NFS_NGROUPS;
Eric W. Biedermanae2975b2011-11-14 15:56:38 -0800133 for (i = 0; i < groups ; i++) {
134 gid_t gid;
135 gid = from_kgid(&init_user_ns, GROUP_AT(acred->group_info, i));
136 if (cred->uc_gids[i] != gid)
Trond Myklebustaf093832008-03-12 12:12:16 -0400137 return 0;
Eric W. Biedermanae2975b2011-11-14 15:56:38 -0800138 }
NeilBrowndc6f55e2011-10-25 10:25:49 +1100139 if (groups < NFS_NGROUPS &&
140 cred->uc_gids[groups] != NOGROUP)
141 return 0;
Trond Myklebustaf093832008-03-12 12:12:16 -0400142 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143}
144
145/*
146 * Marshal credentials.
147 * Maybe we should keep a cached credential for performance reasons.
148 */
Alexey Dobriyand8ed0292006-09-26 22:29:38 -0700149static __be32 *
150unx_marshal(struct rpc_task *task, __be32 *p)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151{
152 struct rpc_clnt *clnt = task->tk_client;
Trond Myklebusta17c2152010-07-31 14:29:08 -0400153 struct unx_cred *cred = container_of(task->tk_rqstp->rq_cred, struct unx_cred, uc_base);
Alexey Dobriyand8ed0292006-09-26 22:29:38 -0700154 __be32 *base, *hold;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 int i;
156
157 *p++ = htonl(RPC_AUTH_UNIX);
158 base = p++;
159 *p++ = htonl(jiffies/HZ);
160
161 /*
162 * Copy the UTS nodename captured when the client was created.
163 */
164 p = xdr_encode_array(p, clnt->cl_nodename, clnt->cl_nodelen);
165
166 *p++ = htonl((u32) cred->uc_uid);
167 *p++ = htonl((u32) cred->uc_gid);
168 hold = p++;
169 for (i = 0; i < 16 && cred->uc_gids[i] != (gid_t) NOGROUP; i++)
170 *p++ = htonl((u32) cred->uc_gids[i]);
171 *hold = htonl(p - hold - 1); /* gid array length */
172 *base = htonl((p - base - 1) << 2); /* cred length */
173
174 *p++ = htonl(RPC_AUTH_NULL);
175 *p++ = htonl(0);
176
177 return p;
178}
179
180/*
181 * Refresh credentials. This is a no-op for AUTH_UNIX
182 */
183static int
184unx_refresh(struct rpc_task *task)
185{
Trond Myklebusta17c2152010-07-31 14:29:08 -0400186 set_bit(RPCAUTH_CRED_UPTODATE, &task->tk_rqstp->rq_cred->cr_flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187 return 0;
188}
189
Alexey Dobriyand8ed0292006-09-26 22:29:38 -0700190static __be32 *
191unx_validate(struct rpc_task *task, __be32 *p)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192{
193 rpc_authflavor_t flavor;
194 u32 size;
195
196 flavor = ntohl(*p++);
197 if (flavor != RPC_AUTH_NULL &&
198 flavor != RPC_AUTH_UNIX &&
199 flavor != RPC_AUTH_SHORT) {
200 printk("RPC: bad verf flavor: %u\n", flavor);
201 return NULL;
202 }
203
204 size = ntohl(*p++);
205 if (size > RPC_MAX_AUTH_SIZE) {
206 printk("RPC: giant verf size: %u\n", size);
207 return NULL;
208 }
Trond Myklebusta17c2152010-07-31 14:29:08 -0400209 task->tk_rqstp->rq_cred->cr_auth->au_rslack = (size >> 2) + 2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210 p += (size >> 2);
211
212 return p;
213}
214
Trond Myklebust5d8d9a42010-07-31 14:29:07 -0400215int __init rpc_init_authunix(void)
Trond Myklebust9499b432007-06-24 15:57:57 -0400216{
Trond Myklebust5d8d9a42010-07-31 14:29:07 -0400217 return rpcauth_init_credcache(&unix_auth);
218}
219
220void rpc_destroy_authunix(void)
221{
222 rpcauth_destroy_credcache(&unix_auth);
Trond Myklebust9499b432007-06-24 15:57:57 -0400223}
224
Trond Myklebustf1c0a862007-06-23 20:17:58 -0400225const struct rpc_authops authunix_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226 .owner = THIS_MODULE,
227 .au_flavor = RPC_AUTH_UNIX,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228 .au_name = "UNIX",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229 .create = unx_create,
230 .destroy = unx_destroy,
231 .lookup_cred = unx_lookup_cred,
232 .crcreate = unx_create_cred,
233};
234
235static
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236struct rpc_auth unix_auth = {
237 .au_cslack = UNX_WRITESLACK,
238 .au_rslack = 2, /* assume AUTH_NULL verf */
239 .au_ops = &authunix_ops,
Trond Myklebust81039f12006-06-09 09:34:34 -0400240 .au_flavor = RPC_AUTH_UNIX,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241 .au_count = ATOMIC_INIT(0),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242};
243
244static
Trond Myklebustf1c0a862007-06-23 20:17:58 -0400245const struct rpc_credops unix_credops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246 .cr_name = "AUTH_UNIX",
247 .crdestroy = unx_destroy_cred,
Trond Myklebust5c691042008-03-12 16:21:07 -0400248 .crbind = rpcauth_generic_bind_cred,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249 .crmatch = unx_match,
250 .crmarshal = unx_marshal,
251 .crrefresh = unx_refresh,
252 .crvalidate = unx_validate,
253};