Commit | Line | Data |
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1da177e4 LT |
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/socket.h> | |
13 | #include <linux/in.h> | |
14 | #include <linux/sunrpc/clnt.h> | |
15 | #include <linux/sunrpc/auth.h> | |
16 | ||
17 | #define NFS_NGROUPS 16 | |
18 | ||
19 | struct 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 | |
25 | #define uc_count uc_base.cr_count | |
26 | #define uc_flags uc_base.cr_flags | |
27 | #define uc_expire uc_base.cr_expire | |
28 | ||
29 | #define UNX_CRED_EXPIRE (60 * HZ) | |
30 | ||
31 | #define UNX_WRITESLACK (21 + (UNX_MAXNODENAME >> 2)) | |
32 | ||
33 | #ifdef RPC_DEBUG | |
34 | # define RPCDBG_FACILITY RPCDBG_AUTH | |
35 | #endif | |
36 | ||
37 | static struct rpc_auth unix_auth; | |
38 | static struct rpc_cred_cache unix_cred_cache; | |
39 | static struct rpc_credops unix_credops; | |
40 | ||
41 | static struct rpc_auth * | |
42 | unx_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor) | |
43 | { | |
44 | dprintk("RPC: creating UNIX authenticator for client %p\n", clnt); | |
45 | if (atomic_inc_return(&unix_auth.au_count) == 0) | |
46 | unix_cred_cache.nextgc = jiffies + (unix_cred_cache.expire >> 1); | |
47 | return &unix_auth; | |
48 | } | |
49 | ||
50 | static void | |
51 | unx_destroy(struct rpc_auth *auth) | |
52 | { | |
53 | dprintk("RPC: destroying UNIX authenticator %p\n", auth); | |
54 | rpcauth_free_credcache(auth); | |
55 | } | |
56 | ||
57 | /* | |
58 | * Lookup AUTH_UNIX creds for current process | |
59 | */ | |
60 | static struct rpc_cred * | |
61 | unx_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags) | |
62 | { | |
63 | return rpcauth_lookup_credcache(auth, acred, flags); | |
64 | } | |
65 | ||
66 | static struct rpc_cred * | |
67 | unx_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags) | |
68 | { | |
69 | struct unx_cred *cred; | |
70 | int i; | |
71 | ||
72 | dprintk("RPC: allocating UNIX cred for uid %d gid %d\n", | |
73 | acred->uid, acred->gid); | |
74 | ||
75 | if (!(cred = (struct unx_cred *) kmalloc(sizeof(*cred), GFP_KERNEL))) | |
76 | return ERR_PTR(-ENOMEM); | |
77 | ||
78 | atomic_set(&cred->uc_count, 1); | |
79 | cred->uc_flags = RPCAUTH_CRED_UPTODATE; | |
80 | if (flags & RPC_TASK_ROOTCREDS) { | |
81 | cred->uc_uid = 0; | |
82 | cred->uc_gid = 0; | |
83 | cred->uc_gids[0] = NOGROUP; | |
84 | } else { | |
85 | int groups = acred->group_info->ngroups; | |
86 | if (groups > NFS_NGROUPS) | |
87 | groups = NFS_NGROUPS; | |
88 | ||
89 | cred->uc_uid = acred->uid; | |
90 | cred->uc_gid = acred->gid; | |
91 | for (i = 0; i < groups; i++) | |
92 | cred->uc_gids[i] = GROUP_AT(acred->group_info, i); | |
93 | if (i < NFS_NGROUPS) | |
94 | cred->uc_gids[i] = NOGROUP; | |
95 | } | |
96 | cred->uc_base.cr_ops = &unix_credops; | |
97 | ||
98 | return (struct rpc_cred *) cred; | |
99 | } | |
100 | ||
101 | static void | |
102 | unx_destroy_cred(struct rpc_cred *cred) | |
103 | { | |
104 | kfree(cred); | |
105 | } | |
106 | ||
107 | /* | |
108 | * Match credentials against current process creds. | |
109 | * The root_override argument takes care of cases where the caller may | |
110 | * request root creds (e.g. for NFS swapping). | |
111 | */ | |
112 | static int | |
113 | unx_match(struct auth_cred *acred, struct rpc_cred *rcred, int taskflags) | |
114 | { | |
115 | struct unx_cred *cred = (struct unx_cred *) rcred; | |
116 | int i; | |
117 | ||
118 | if (!(taskflags & RPC_TASK_ROOTCREDS)) { | |
119 | int groups; | |
120 | ||
121 | if (cred->uc_uid != acred->uid | |
122 | || cred->uc_gid != acred->gid) | |
123 | return 0; | |
124 | ||
125 | groups = acred->group_info->ngroups; | |
126 | if (groups > NFS_NGROUPS) | |
127 | groups = NFS_NGROUPS; | |
128 | for (i = 0; i < groups ; i++) | |
129 | if (cred->uc_gids[i] != GROUP_AT(acred->group_info, i)) | |
130 | return 0; | |
131 | return 1; | |
132 | } | |
133 | return (cred->uc_uid == 0 | |
134 | && cred->uc_gid == 0 | |
135 | && cred->uc_gids[0] == (gid_t) NOGROUP); | |
136 | } | |
137 | ||
138 | /* | |
139 | * Marshal credentials. | |
140 | * Maybe we should keep a cached credential for performance reasons. | |
141 | */ | |
142 | static u32 * | |
143 | unx_marshal(struct rpc_task *task, u32 *p) | |
144 | { | |
145 | struct rpc_clnt *clnt = task->tk_client; | |
146 | struct unx_cred *cred = (struct unx_cred *) task->tk_msg.rpc_cred; | |
147 | u32 *base, *hold; | |
148 | int i; | |
149 | ||
150 | *p++ = htonl(RPC_AUTH_UNIX); | |
151 | base = p++; | |
152 | *p++ = htonl(jiffies/HZ); | |
153 | ||
154 | /* | |
155 | * Copy the UTS nodename captured when the client was created. | |
156 | */ | |
157 | p = xdr_encode_array(p, clnt->cl_nodename, clnt->cl_nodelen); | |
158 | ||
159 | *p++ = htonl((u32) cred->uc_uid); | |
160 | *p++ = htonl((u32) cred->uc_gid); | |
161 | hold = p++; | |
162 | for (i = 0; i < 16 && cred->uc_gids[i] != (gid_t) NOGROUP; i++) | |
163 | *p++ = htonl((u32) cred->uc_gids[i]); | |
164 | *hold = htonl(p - hold - 1); /* gid array length */ | |
165 | *base = htonl((p - base - 1) << 2); /* cred length */ | |
166 | ||
167 | *p++ = htonl(RPC_AUTH_NULL); | |
168 | *p++ = htonl(0); | |
169 | ||
170 | return p; | |
171 | } | |
172 | ||
173 | /* | |
174 | * Refresh credentials. This is a no-op for AUTH_UNIX | |
175 | */ | |
176 | static int | |
177 | unx_refresh(struct rpc_task *task) | |
178 | { | |
179 | task->tk_msg.rpc_cred->cr_flags |= RPCAUTH_CRED_UPTODATE; | |
180 | return 0; | |
181 | } | |
182 | ||
183 | static u32 * | |
184 | unx_validate(struct rpc_task *task, u32 *p) | |
185 | { | |
186 | rpc_authflavor_t flavor; | |
187 | u32 size; | |
188 | ||
189 | flavor = ntohl(*p++); | |
190 | if (flavor != RPC_AUTH_NULL && | |
191 | flavor != RPC_AUTH_UNIX && | |
192 | flavor != RPC_AUTH_SHORT) { | |
193 | printk("RPC: bad verf flavor: %u\n", flavor); | |
194 | return NULL; | |
195 | } | |
196 | ||
197 | size = ntohl(*p++); | |
198 | if (size > RPC_MAX_AUTH_SIZE) { | |
199 | printk("RPC: giant verf size: %u\n", size); | |
200 | return NULL; | |
201 | } | |
202 | task->tk_auth->au_rslack = (size >> 2) + 2; | |
203 | p += (size >> 2); | |
204 | ||
205 | return p; | |
206 | } | |
207 | ||
208 | struct rpc_authops authunix_ops = { | |
209 | .owner = THIS_MODULE, | |
210 | .au_flavor = RPC_AUTH_UNIX, | |
211 | #ifdef RPC_DEBUG | |
212 | .au_name = "UNIX", | |
213 | #endif | |
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 | .expire = UNX_CRED_EXPIRE, | |
223 | }; | |
224 | ||
225 | static | |
226 | struct rpc_auth unix_auth = { | |
227 | .au_cslack = UNX_WRITESLACK, | |
228 | .au_rslack = 2, /* assume AUTH_NULL verf */ | |
229 | .au_ops = &authunix_ops, | |
230 | .au_count = ATOMIC_INIT(0), | |
231 | .au_credcache = &unix_cred_cache, | |
232 | }; | |
233 | ||
234 | static | |
235 | struct 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 | }; |