blob: 4e7733aee36e8f42dafa178cceabdfa028a3dbae [file] [log] [blame]
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
9#include <linux/types.h>
10#include <linux/sched.h>
11#include <linux/module.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#include <linux/sunrpc/clnt.h>
13#include <linux/sunrpc/auth.h>
14
15#define NFS_NGROUPS 16
16
17struct 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#define uc_count uc_base.cr_count
24#define uc_flags uc_base.cr_flags
25#define uc_expire uc_base.cr_expire
26
27#define UNX_CRED_EXPIRE (60 * HZ)
28
29#define UNX_WRITESLACK (21 + (UNX_MAXNODENAME >> 2))
30
31#ifdef RPC_DEBUG
32# define RPCDBG_FACILITY RPCDBG_AUTH
33#endif
34
35static struct rpc_auth unix_auth;
36static struct rpc_cred_cache unix_cred_cache;
37static struct rpc_credops unix_credops;
38
39static struct rpc_auth *
40unx_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
41{
Chuck Lever46121cf2007-01-31 12:14:08 -050042 dprintk("RPC: creating UNIX authenticator for client %p\n",
43 clnt);
Linus Torvalds1da177e2005-04-16 15:20:36 -070044 if (atomic_inc_return(&unix_auth.au_count) == 0)
45 unix_cred_cache.nextgc = jiffies + (unix_cred_cache.expire >> 1);
46 return &unix_auth;
47}
48
49static void
50unx_destroy(struct rpc_auth *auth)
51{
Chuck Lever46121cf2007-01-31 12:14:08 -050052 dprintk("RPC: destroying UNIX authenticator %p\n", auth);
Linus Torvalds1da177e2005-04-16 15:20:36 -070053 rpcauth_free_credcache(auth);
54}
55
56/*
57 * Lookup AUTH_UNIX creds for current process
58 */
59static struct rpc_cred *
60unx_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
61{
62 return rpcauth_lookup_credcache(auth, acred, flags);
63}
64
65static struct rpc_cred *
66unx_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
67{
68 struct unx_cred *cred;
69 int i;
70
Chuck Lever46121cf2007-01-31 12:14:08 -050071 dprintk("RPC: allocating UNIX cred for uid %d gid %d\n",
72 acred->uid, acred->gid);
Linus Torvalds1da177e2005-04-16 15:20:36 -070073
Kris Katterjohn8b3a7002006-01-11 15:56:43 -080074 if (!(cred = kmalloc(sizeof(*cred), GFP_KERNEL)))
Linus Torvalds1da177e2005-04-16 15:20:36 -070075 return ERR_PTR(-ENOMEM);
76
77 atomic_set(&cred->uc_count, 1);
78 cred->uc_flags = RPCAUTH_CRED_UPTODATE;
Trond Myklebust8a317762006-02-01 12:18:36 -050079 if (flags & RPCAUTH_LOOKUP_ROOTCREDS) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070080 cred->uc_uid = 0;
81 cred->uc_gid = 0;
82 cred->uc_gids[0] = NOGROUP;
83 } else {
84 int groups = acred->group_info->ngroups;
85 if (groups > NFS_NGROUPS)
86 groups = NFS_NGROUPS;
87
88 cred->uc_uid = acred->uid;
89 cred->uc_gid = acred->gid;
90 for (i = 0; i < groups; i++)
91 cred->uc_gids[i] = GROUP_AT(acred->group_info, i);
92 if (i < NFS_NGROUPS)
93 cred->uc_gids[i] = NOGROUP;
94 }
95 cred->uc_base.cr_ops = &unix_credops;
96
97 return (struct rpc_cred *) cred;
98}
99
100static void
101unx_destroy_cred(struct rpc_cred *cred)
102{
103 kfree(cred);
104}
105
106/*
107 * Match credentials against current process creds.
108 * The root_override argument takes care of cases where the caller may
109 * request root creds (e.g. for NFS swapping).
110 */
111static int
Trond Myklebust8a317762006-02-01 12:18:36 -0500112unx_match(struct auth_cred *acred, struct rpc_cred *rcred, int flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113{
114 struct unx_cred *cred = (struct unx_cred *) rcred;
115 int i;
116
Trond Myklebust8a317762006-02-01 12:18:36 -0500117 if (!(flags & RPCAUTH_LOOKUP_ROOTCREDS)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118 int groups;
119
120 if (cred->uc_uid != acred->uid
121 || cred->uc_gid != acred->gid)
122 return 0;
123
124 groups = acred->group_info->ngroups;
125 if (groups > NFS_NGROUPS)
126 groups = NFS_NGROUPS;
127 for (i = 0; i < groups ; i++)
128 if (cred->uc_gids[i] != GROUP_AT(acred->group_info, i))
129 return 0;
130 return 1;
131 }
132 return (cred->uc_uid == 0
133 && cred->uc_gid == 0
134 && cred->uc_gids[0] == (gid_t) NOGROUP);
135}
136
137/*
138 * Marshal credentials.
139 * Maybe we should keep a cached credential for performance reasons.
140 */
Alexey Dobriyand8ed0292006-09-26 22:29:38 -0700141static __be32 *
142unx_marshal(struct rpc_task *task, __be32 *p)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143{
144 struct rpc_clnt *clnt = task->tk_client;
145 struct unx_cred *cred = (struct unx_cred *) task->tk_msg.rpc_cred;
Alexey Dobriyand8ed0292006-09-26 22:29:38 -0700146 __be32 *base, *hold;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147 int i;
148
149 *p++ = htonl(RPC_AUTH_UNIX);
150 base = p++;
151 *p++ = htonl(jiffies/HZ);
152
153 /*
154 * Copy the UTS nodename captured when the client was created.
155 */
156 p = xdr_encode_array(p, clnt->cl_nodename, clnt->cl_nodelen);
157
158 *p++ = htonl((u32) cred->uc_uid);
159 *p++ = htonl((u32) cred->uc_gid);
160 hold = p++;
161 for (i = 0; i < 16 && cred->uc_gids[i] != (gid_t) NOGROUP; i++)
162 *p++ = htonl((u32) cred->uc_gids[i]);
163 *hold = htonl(p - hold - 1); /* gid array length */
164 *base = htonl((p - base - 1) << 2); /* cred length */
165
166 *p++ = htonl(RPC_AUTH_NULL);
167 *p++ = htonl(0);
168
169 return p;
170}
171
172/*
173 * Refresh credentials. This is a no-op for AUTH_UNIX
174 */
175static int
176unx_refresh(struct rpc_task *task)
177{
178 task->tk_msg.rpc_cred->cr_flags |= RPCAUTH_CRED_UPTODATE;
179 return 0;
180}
181
Alexey Dobriyand8ed0292006-09-26 22:29:38 -0700182static __be32 *
183unx_validate(struct rpc_task *task, __be32 *p)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184{
185 rpc_authflavor_t flavor;
186 u32 size;
187
188 flavor = ntohl(*p++);
189 if (flavor != RPC_AUTH_NULL &&
190 flavor != RPC_AUTH_UNIX &&
191 flavor != RPC_AUTH_SHORT) {
192 printk("RPC: bad verf flavor: %u\n", flavor);
193 return NULL;
194 }
195
196 size = ntohl(*p++);
197 if (size > RPC_MAX_AUTH_SIZE) {
198 printk("RPC: giant verf size: %u\n", size);
199 return NULL;
200 }
201 task->tk_auth->au_rslack = (size >> 2) + 2;
202 p += (size >> 2);
203
204 return p;
205}
206
207struct rpc_authops authunix_ops = {
208 .owner = THIS_MODULE,
209 .au_flavor = RPC_AUTH_UNIX,
210#ifdef RPC_DEBUG
211 .au_name = "UNIX",
212#endif
213 .create = unx_create,
214 .destroy = unx_destroy,
215 .lookup_cred = unx_lookup_cred,
216 .crcreate = unx_create_cred,
217};
218
219static
220struct rpc_cred_cache unix_cred_cache = {
221 .expire = UNX_CRED_EXPIRE,
222};
223
224static
225struct rpc_auth unix_auth = {
226 .au_cslack = UNX_WRITESLACK,
227 .au_rslack = 2, /* assume AUTH_NULL verf */
228 .au_ops = &authunix_ops,
Trond Myklebust81039f12006-06-09 09:34:34 -0400229 .au_flavor = RPC_AUTH_UNIX,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230 .au_count = ATOMIC_INIT(0),
231 .au_credcache = &unix_cred_cache,
232};
233
234static
235struct rpc_credops unix_credops = {
236 .cr_name = "AUTH_UNIX",
237 .crdestroy = unx_destroy_cred,
238 .crmatch = unx_match,
239 .crmarshal = unx_marshal,
240 .crrefresh = unx_refresh,
241 .crvalidate = unx_validate,
242};