2 * linux/net/sunrpc/auth_unix.c
4 * UNIX-style authentication; no AUTH_SHORT support
6 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
9 #include <linux/slab.h>
10 #include <linux/types.h>
11 #include <linux/sched.h>
12 #include <linux/module.h>
13 #include <linux/sunrpc/clnt.h>
14 #include <linux/sunrpc/auth.h>
15 #include <linux/user_namespace.h>
17 #define NFS_NGROUPS 16
20 struct rpc_cred uc_base;
22 kgid_t uc_gids[NFS_NGROUPS];
24 #define uc_uid uc_base.cr_uid
26 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
27 # define RPCDBG_FACILITY RPCDBG_AUTH
30 static struct rpc_auth unix_auth;
31 static const struct rpc_credops unix_credops;
33 static struct rpc_auth *
34 unx_create(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
36 dprintk("RPC: creating UNIX authenticator for client %p\n",
38 atomic_inc(&unix_auth.au_count);
43 unx_destroy(struct rpc_auth *auth)
45 dprintk("RPC: destroying UNIX authenticator %p\n", auth);
46 rpcauth_clear_credcache(auth->au_credcache);
50 unx_hash_cred(struct auth_cred *acred, unsigned int hashbits)
52 return hash_64(from_kgid(&init_user_ns, acred->gid) |
53 ((u64)from_kuid(&init_user_ns, acred->uid) <<
54 (sizeof(gid_t) * 8)), hashbits);
58 * Lookup AUTH_UNIX creds for current process
60 static struct rpc_cred *
61 unx_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
63 return rpcauth_lookup_credcache(auth, acred, flags, GFP_NOFS);
66 static struct rpc_cred *
67 unx_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags, gfp_t gfp)
69 struct unx_cred *cred;
70 unsigned int groups = 0;
73 dprintk("RPC: allocating UNIX cred for uid %d gid %d\n",
74 from_kuid(&init_user_ns, acred->uid),
75 from_kgid(&init_user_ns, acred->gid));
77 if (!(cred = kmalloc(sizeof(*cred), gfp)))
78 return ERR_PTR(-ENOMEM);
80 rpcauth_init_cred(&cred->uc_base, acred, auth, &unix_credops);
81 cred->uc_base.cr_flags = 1UL << RPCAUTH_CRED_UPTODATE;
83 if (acred->group_info != NULL)
84 groups = acred->group_info->ngroups;
85 if (groups > NFS_NGROUPS)
88 cred->uc_gid = acred->gid;
89 for (i = 0; i < groups; i++)
90 cred->uc_gids[i] = acred->group_info->gid[i];
92 cred->uc_gids[i] = INVALID_GID;
94 return &cred->uc_base;
98 unx_free_cred(struct unx_cred *unx_cred)
100 dprintk("RPC: unx_free_cred %p\n", unx_cred);
105 unx_free_cred_callback(struct rcu_head *head)
107 struct unx_cred *unx_cred = container_of(head, struct unx_cred, uc_base.cr_rcu);
108 unx_free_cred(unx_cred);
112 unx_destroy_cred(struct rpc_cred *cred)
114 call_rcu(&cred->cr_rcu, unx_free_cred_callback);
118 * Match credentials against current process creds.
119 * The root_override argument takes care of cases where the caller may
120 * request root creds (e.g. for NFS swapping).
123 unx_match(struct auth_cred *acred, struct rpc_cred *rcred, int flags)
125 struct unx_cred *cred = container_of(rcred, struct unx_cred, uc_base);
126 unsigned int groups = 0;
130 if (!uid_eq(cred->uc_uid, acred->uid) || !gid_eq(cred->uc_gid, acred->gid))
133 if (acred->group_info != NULL)
134 groups = acred->group_info->ngroups;
135 if (groups > NFS_NGROUPS)
136 groups = NFS_NGROUPS;
137 for (i = 0; i < groups ; i++)
138 if (!gid_eq(cred->uc_gids[i], acred->group_info->gid[i]))
140 if (groups < NFS_NGROUPS && gid_valid(cred->uc_gids[groups]))
146 * Marshal credentials.
147 * Maybe we should keep a cached credential for performance reasons.
150 unx_marshal(struct rpc_task *task, __be32 *p)
152 struct rpc_clnt *clnt = task->tk_client;
153 struct unx_cred *cred = container_of(task->tk_rqstp->rq_cred, struct unx_cred, uc_base);
157 *p++ = htonl(RPC_AUTH_UNIX);
159 *p++ = htonl(jiffies/HZ);
162 * Copy the UTS nodename captured when the client was created.
164 p = xdr_encode_array(p, clnt->cl_nodename, clnt->cl_nodelen);
166 *p++ = htonl((u32) from_kuid(&init_user_ns, cred->uc_uid));
167 *p++ = htonl((u32) from_kgid(&init_user_ns, cred->uc_gid));
169 for (i = 0; i < 16 && gid_valid(cred->uc_gids[i]); i++)
170 *p++ = htonl((u32) from_kgid(&init_user_ns, cred->uc_gids[i]));
171 *hold = htonl(p - hold - 1); /* gid array length */
172 *base = htonl((p - base - 1) << 2); /* cred length */
174 *p++ = htonl(RPC_AUTH_NULL);
181 * Refresh credentials. This is a no-op for AUTH_UNIX
184 unx_refresh(struct rpc_task *task)
186 set_bit(RPCAUTH_CRED_UPTODATE, &task->tk_rqstp->rq_cred->cr_flags);
191 unx_validate(struct rpc_task *task, __be32 *p)
193 rpc_authflavor_t flavor;
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 ERR_PTR(-EIO);
205 if (size > RPC_MAX_AUTH_SIZE) {
206 printk("RPC: giant verf size: %u\n", size);
207 return ERR_PTR(-EIO);
209 task->tk_rqstp->rq_cred->cr_auth->au_rslack = (size >> 2) + 2;
215 int __init rpc_init_authunix(void)
217 return rpcauth_init_credcache(&unix_auth);
220 void rpc_destroy_authunix(void)
222 rpcauth_destroy_credcache(&unix_auth);
225 const struct rpc_authops authunix_ops = {
226 .owner = THIS_MODULE,
227 .au_flavor = RPC_AUTH_UNIX,
229 .create = unx_create,
230 .destroy = unx_destroy,
231 .hash_cred = unx_hash_cred,
232 .lookup_cred = unx_lookup_cred,
233 .crcreate = unx_create_cred,
237 struct rpc_auth unix_auth = {
238 .au_cslack = UNX_CALLSLACK,
239 .au_rslack = NUL_REPLYSLACK,
240 .au_flags = RPCAUTH_AUTH_NO_CRKEY_TIMEOUT,
241 .au_ops = &authunix_ops,
242 .au_flavor = RPC_AUTH_UNIX,
243 .au_count = ATOMIC_INIT(0),
247 const struct rpc_credops unix_credops = {
248 .cr_name = "AUTH_UNIX",
249 .crdestroy = unx_destroy_cred,
250 .crbind = rpcauth_generic_bind_cred,
251 .crmatch = unx_match,
252 .crmarshal = unx_marshal,
253 .crrefresh = unx_refresh,
254 .crvalidate = unx_validate,