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 * Lookup AUTH_UNIX creds for current process
52 static struct rpc_cred *
53 unx_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
55 return rpcauth_lookup_credcache(auth, acred, flags);
58 static struct rpc_cred *
59 unx_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
61 struct unx_cred *cred;
62 unsigned int groups = 0;
65 dprintk("RPC: allocating UNIX cred for uid %d gid %d\n",
66 from_kuid(&init_user_ns, acred->uid),
67 from_kgid(&init_user_ns, acred->gid));
69 if (!(cred = kmalloc(sizeof(*cred), GFP_NOFS)))
70 return ERR_PTR(-ENOMEM);
72 rpcauth_init_cred(&cred->uc_base, acred, auth, &unix_credops);
73 cred->uc_base.cr_flags = 1UL << RPCAUTH_CRED_UPTODATE;
75 if (acred->group_info != NULL)
76 groups = acred->group_info->ngroups;
77 if (groups > NFS_NGROUPS)
80 cred->uc_gid = acred->gid;
81 for (i = 0; i < groups; i++)
82 cred->uc_gids[i] = GROUP_AT(acred->group_info, i);
84 cred->uc_gids[i] = INVALID_GID;
86 return &cred->uc_base;
90 unx_free_cred(struct unx_cred *unx_cred)
92 dprintk("RPC: unx_free_cred %p\n", unx_cred);
97 unx_free_cred_callback(struct rcu_head *head)
99 struct unx_cred *unx_cred = container_of(head, struct unx_cred, uc_base.cr_rcu);
100 unx_free_cred(unx_cred);
104 unx_destroy_cred(struct rpc_cred *cred)
106 call_rcu(&cred->cr_rcu, unx_free_cred_callback);
110 * Match credentials against current process creds.
111 * The root_override argument takes care of cases where the caller may
112 * request root creds (e.g. for NFS swapping).
115 unx_match(struct auth_cred *acred, struct rpc_cred *rcred, int flags)
117 struct unx_cred *cred = container_of(rcred, struct unx_cred, uc_base);
118 unsigned int groups = 0;
122 if (!uid_eq(cred->uc_uid, acred->uid) || !gid_eq(cred->uc_gid, acred->gid))
125 if (acred->group_info != NULL)
126 groups = acred->group_info->ngroups;
127 if (groups > NFS_NGROUPS)
128 groups = NFS_NGROUPS;
129 for (i = 0; i < groups ; i++)
130 if (!gid_eq(cred->uc_gids[i], GROUP_AT(acred->group_info, i)))
132 if (groups < NFS_NGROUPS && gid_valid(cred->uc_gids[groups]))
138 * Marshal credentials.
139 * Maybe we should keep a cached credential for performance reasons.
142 unx_marshal(struct rpc_task *task, __be32 *p)
144 struct rpc_clnt *clnt = task->tk_client;
145 struct unx_cred *cred = container_of(task->tk_rqstp->rq_cred, struct unx_cred, uc_base);
149 *p++ = htonl(RPC_AUTH_UNIX);
151 *p++ = htonl(jiffies/HZ);
154 * Copy the UTS nodename captured when the client was created.
156 p = xdr_encode_array(p, clnt->cl_nodename, clnt->cl_nodelen);
158 *p++ = htonl((u32) from_kuid(&init_user_ns, cred->uc_uid));
159 *p++ = htonl((u32) from_kgid(&init_user_ns, cred->uc_gid));
161 for (i = 0; i < 16 && gid_valid(cred->uc_gids[i]); i++)
162 *p++ = htonl((u32) from_kgid(&init_user_ns, cred->uc_gids[i]));
163 *hold = htonl(p - hold - 1); /* gid array length */
164 *base = htonl((p - base - 1) << 2); /* cred length */
166 *p++ = htonl(RPC_AUTH_NULL);
173 * Refresh credentials. This is a no-op for AUTH_UNIX
176 unx_refresh(struct rpc_task *task)
178 set_bit(RPCAUTH_CRED_UPTODATE, &task->tk_rqstp->rq_cred->cr_flags);
183 unx_validate(struct rpc_task *task, __be32 *p)
185 rpc_authflavor_t flavor;
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 ERR_PTR(-EIO);
197 if (size > RPC_MAX_AUTH_SIZE) {
198 printk("RPC: giant verf size: %u\n", size);
199 return ERR_PTR(-EIO);
201 task->tk_rqstp->rq_cred->cr_auth->au_rslack = (size >> 2) + 2;
207 int __init rpc_init_authunix(void)
209 return rpcauth_init_credcache(&unix_auth);
212 void rpc_destroy_authunix(void)
214 rpcauth_destroy_credcache(&unix_auth);
217 const struct rpc_authops authunix_ops = {
218 .owner = THIS_MODULE,
219 .au_flavor = RPC_AUTH_UNIX,
221 .create = unx_create,
222 .destroy = unx_destroy,
223 .lookup_cred = unx_lookup_cred,
224 .crcreate = unx_create_cred,
228 struct rpc_auth unix_auth = {
229 .au_cslack = UNX_CALLSLACK,
230 .au_rslack = NUL_REPLYSLACK,
231 .au_ops = &authunix_ops,
232 .au_flavor = RPC_AUTH_UNIX,
233 .au_count = ATOMIC_INIT(0),
237 const struct rpc_credops unix_credops = {
238 .cr_name = "AUTH_UNIX",
239 .crdestroy = unx_destroy_cred,
240 .crbind = rpcauth_generic_bind_cred,
241 .crmatch = unx_match,
242 .crmarshal = unx_marshal,
243 .crrefresh = unx_refresh,
244 .crvalidate = unx_validate,