blob: f7f990c9afe2ef805b2ea75e1d9b23dbb7f2d2fc [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{
42 dprintk("RPC: creating UNIX authenticator for client %p\n", clnt);
43 if (atomic_inc_return(&unix_auth.au_count) == 0)
44 unix_cred_cache.nextgc = jiffies + (unix_cred_cache.expire >> 1);
45 return &unix_auth;
46}
47
48static void
49unx_destroy(struct rpc_auth *auth)
50{
51 dprintk("RPC: destroying UNIX authenticator %p\n", auth);
52 rpcauth_free_credcache(auth);
53}
54
55/*
56 * Lookup AUTH_UNIX creds for current process
57 */
58static struct rpc_cred *
59unx_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
60{
61 return rpcauth_lookup_credcache(auth, acred, flags);
62}
63
64static struct rpc_cred *
65unx_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
66{
67 struct unx_cred *cred;
68 int i;
69
70 dprintk("RPC: allocating UNIX cred for uid %d gid %d\n",
71 acred->uid, acred->gid);
72
Kris Katterjohn8b3a7002006-01-11 15:56:43 -080073 if (!(cred = kmalloc(sizeof(*cred), GFP_KERNEL)))
Linus Torvalds1da177e2005-04-16 15:20:36 -070074 return ERR_PTR(-ENOMEM);
75
76 atomic_set(&cred->uc_count, 1);
77 cred->uc_flags = RPCAUTH_CRED_UPTODATE;
Trond Myklebust8a317762006-02-01 12:18:36 -050078 if (flags & RPCAUTH_LOOKUP_ROOTCREDS) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070079 cred->uc_uid = 0;
80 cred->uc_gid = 0;
81 cred->uc_gids[0] = NOGROUP;
82 } else {
83 int groups = acred->group_info->ngroups;
84 if (groups > NFS_NGROUPS)
85 groups = NFS_NGROUPS;
86
87 cred->uc_uid = acred->uid;
88 cred->uc_gid = acred->gid;
89 for (i = 0; i < groups; i++)
90 cred->uc_gids[i] = GROUP_AT(acred->group_info, i);
91 if (i < NFS_NGROUPS)
92 cred->uc_gids[i] = NOGROUP;
93 }
94 cred->uc_base.cr_ops = &unix_credops;
95
96 return (struct rpc_cred *) cred;
97}
98
99static void
100unx_destroy_cred(struct rpc_cred *cred)
101{
102 kfree(cred);
103}
104
105/*
106 * Match credentials against current process creds.
107 * The root_override argument takes care of cases where the caller may
108 * request root creds (e.g. for NFS swapping).
109 */
110static int
Trond Myklebust8a317762006-02-01 12:18:36 -0500111unx_match(struct auth_cred *acred, struct rpc_cred *rcred, int flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112{
113 struct unx_cred *cred = (struct unx_cred *) rcred;
114 int i;
115
Trond Myklebust8a317762006-02-01 12:18:36 -0500116 if (!(flags & RPCAUTH_LOOKUP_ROOTCREDS)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117 int groups;
118
119 if (cred->uc_uid != acred->uid
120 || cred->uc_gid != acred->gid)
121 return 0;
122
123 groups = acred->group_info->ngroups;
124 if (groups > NFS_NGROUPS)
125 groups = NFS_NGROUPS;
126 for (i = 0; i < groups ; i++)
127 if (cred->uc_gids[i] != GROUP_AT(acred->group_info, i))
128 return 0;
129 return 1;
130 }
131 return (cred->uc_uid == 0
132 && cred->uc_gid == 0
133 && cred->uc_gids[0] == (gid_t) NOGROUP);
134}
135
136/*
137 * Marshal credentials.
138 * Maybe we should keep a cached credential for performance reasons.
139 */
Alexey Dobriyand8ed0292006-09-26 22:29:38 -0700140static __be32 *
141unx_marshal(struct rpc_task *task, __be32 *p)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142{
143 struct rpc_clnt *clnt = task->tk_client;
144 struct unx_cred *cred = (struct unx_cred *) task->tk_msg.rpc_cred;
Alexey Dobriyand8ed0292006-09-26 22:29:38 -0700145 __be32 *base, *hold;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146 int i;
147
148 *p++ = htonl(RPC_AUTH_UNIX);
149 base = p++;
150 *p++ = htonl(jiffies/HZ);
151
152 /*
153 * Copy the UTS nodename captured when the client was created.
154 */
155 p = xdr_encode_array(p, clnt->cl_nodename, clnt->cl_nodelen);
156
157 *p++ = htonl((u32) cred->uc_uid);
158 *p++ = htonl((u32) cred->uc_gid);
159 hold = p++;
160 for (i = 0; i < 16 && cred->uc_gids[i] != (gid_t) NOGROUP; i++)
161 *p++ = htonl((u32) cred->uc_gids[i]);
162 *hold = htonl(p - hold - 1); /* gid array length */
163 *base = htonl((p - base - 1) << 2); /* cred length */
164
165 *p++ = htonl(RPC_AUTH_NULL);
166 *p++ = htonl(0);
167
168 return p;
169}
170
171/*
172 * Refresh credentials. This is a no-op for AUTH_UNIX
173 */
174static int
175unx_refresh(struct rpc_task *task)
176{
177 task->tk_msg.rpc_cred->cr_flags |= RPCAUTH_CRED_UPTODATE;
178 return 0;
179}
180
Alexey Dobriyand8ed0292006-09-26 22:29:38 -0700181static __be32 *
182unx_validate(struct rpc_task *task, __be32 *p)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183{
184 rpc_authflavor_t flavor;
185 u32 size;
186
187 flavor = ntohl(*p++);
188 if (flavor != RPC_AUTH_NULL &&
189 flavor != RPC_AUTH_UNIX &&
190 flavor != RPC_AUTH_SHORT) {
191 printk("RPC: bad verf flavor: %u\n", flavor);
192 return NULL;
193 }
194
195 size = ntohl(*p++);
196 if (size > RPC_MAX_AUTH_SIZE) {
197 printk("RPC: giant verf size: %u\n", size);
198 return NULL;
199 }
200 task->tk_auth->au_rslack = (size >> 2) + 2;
201 p += (size >> 2);
202
203 return p;
204}
205
206struct rpc_authops authunix_ops = {
207 .owner = THIS_MODULE,
208 .au_flavor = RPC_AUTH_UNIX,
209#ifdef RPC_DEBUG
210 .au_name = "UNIX",
211#endif
212 .create = unx_create,
213 .destroy = unx_destroy,
214 .lookup_cred = unx_lookup_cred,
215 .crcreate = unx_create_cred,
216};
217
218static
219struct rpc_cred_cache unix_cred_cache = {
220 .expire = UNX_CRED_EXPIRE,
221};
222
223static
224struct rpc_auth unix_auth = {
225 .au_cslack = UNX_WRITESLACK,
226 .au_rslack = 2, /* assume AUTH_NULL verf */
227 .au_ops = &authunix_ops,
Trond Myklebust81039f12006-06-09 09:34:34 -0400228 .au_flavor = RPC_AUTH_UNIX,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229 .au_count = ATOMIC_INIT(0),
230 .au_credcache = &unix_cred_cache,
231};
232
233static
234struct rpc_credops unix_credops = {
235 .cr_name = "AUTH_UNIX",
236 .crdestroy = unx_destroy_cred,
237 .crmatch = unx_match,
238 .crmarshal = unx_marshal,
239 .crrefresh = unx_refresh,
240 .crvalidate = unx_validate,
241};