1 // SPDX-License-Identifier: GPL-2.0
3 * linux/net/sunrpc/auth_unix.c
5 * UNIX-style authentication; no AUTH_SHORT support
7 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
10 #include <linux/slab.h>
11 #include <linux/types.h>
12 #include <linux/sched.h>
13 #include <linux/module.h>
14 #include <linux/mempool.h>
15 #include <linux/sunrpc/clnt.h>
16 #include <linux/sunrpc/auth.h>
17 #include <linux/user_namespace.h>
20 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
21 # define RPCDBG_FACILITY RPCDBG_AUTH
24 static struct rpc_auth unix_auth;
25 static const struct rpc_credops unix_credops;
26 static mempool_t *unix_pool;
28 static struct rpc_auth *
29 unx_create(const struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
31 refcount_inc(&unix_auth.au_count);
36 unx_destroy(struct rpc_auth *auth)
41 * Lookup AUTH_UNIX creds for current process
43 static struct rpc_cred *
44 unx_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
46 struct rpc_cred *ret = mempool_alloc(unix_pool, GFP_NOFS);
48 rpcauth_init_cred(ret, acred, auth, &unix_credops);
49 ret->cr_flags = 1UL << RPCAUTH_CRED_UPTODATE;
54 unx_free_cred_callback(struct rcu_head *head)
56 struct rpc_cred *rpc_cred = container_of(head, struct rpc_cred, cr_rcu);
58 put_cred(rpc_cred->cr_cred);
59 mempool_free(rpc_cred, unix_pool);
63 unx_destroy_cred(struct rpc_cred *cred)
65 call_rcu(&cred->cr_rcu, unx_free_cred_callback);
69 * Match credentials against current the auth_cred.
72 unx_match(struct auth_cred *acred, struct rpc_cred *cred, int flags)
74 unsigned int groups = 0;
77 if (cred->cr_cred == acred->cred)
80 if (!uid_eq(cred->cr_cred->fsuid, acred->cred->fsuid) || !gid_eq(cred->cr_cred->fsgid, acred->cred->fsgid))
83 if (acred->cred->group_info != NULL)
84 groups = acred->cred->group_info->ngroups;
85 if (groups > UNX_NGROUPS)
87 if (cred->cr_cred->group_info == NULL)
89 if (groups != cred->cr_cred->group_info->ngroups)
92 for (i = 0; i < groups ; i++)
93 if (!gid_eq(cred->cr_cred->group_info->gid[i], acred->cred->group_info->gid[i]))
99 * Marshal credentials.
100 * Maybe we should keep a cached credential for performance reasons.
103 unx_marshal(struct rpc_task *task, struct xdr_stream *xdr)
105 struct rpc_clnt *clnt = task->tk_client;
106 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
107 __be32 *p, *cred_len, *gidarr_len;
109 struct group_info *gi = cred->cr_cred->group_info;
113 p = xdr_reserve_space(xdr, 3 * sizeof(*p));
116 *p++ = rpc_auth_unix;
118 *p++ = xdr_zero; /* stamp */
119 if (xdr_stream_encode_opaque(xdr, clnt->cl_nodename,
120 clnt->cl_nodelen) < 0)
122 p = xdr_reserve_space(xdr, 3 * sizeof(*p));
125 *p++ = cpu_to_be32(from_kuid(&init_user_ns, cred->cr_cred->fsuid));
126 *p++ = cpu_to_be32(from_kgid(&init_user_ns, cred->cr_cred->fsgid));
130 for (i = 0; i < UNX_NGROUPS && i < gi->ngroups; i++)
131 *p++ = cpu_to_be32(from_kgid(&init_user_ns,
133 *gidarr_len = cpu_to_be32(p - gidarr_len - 1);
134 *cred_len = cpu_to_be32((p - cred_len - 1) << 2);
135 p = xdr_reserve_space(xdr, (p - gidarr_len - 1) << 2);
141 p = xdr_reserve_space(xdr, 2 * sizeof(*p));
144 *p++ = rpc_auth_null;
154 * Refresh credentials. This is a no-op for AUTH_UNIX
157 unx_refresh(struct rpc_task *task)
159 set_bit(RPCAUTH_CRED_UPTODATE, &task->tk_rqstp->rq_cred->cr_flags);
164 unx_validate(struct rpc_task *task, struct xdr_stream *xdr)
166 struct rpc_auth *auth = task->tk_rqstp->rq_cred->cr_auth;
170 p = xdr_inline_decode(xdr, 2 * sizeof(*p));
181 size = be32_to_cpup(p);
182 if (size > RPC_MAX_AUTH_SIZE)
184 p = xdr_inline_decode(xdr, size);
188 auth->au_verfsize = XDR_QUADLEN(size) + 2;
189 auth->au_rslack = XDR_QUADLEN(size) + 2;
190 auth->au_ralign = XDR_QUADLEN(size) + 2;
194 int __init rpc_init_authunix(void)
196 unix_pool = mempool_create_kmalloc_pool(16, sizeof(struct rpc_cred));
197 return unix_pool ? 0 : -ENOMEM;
200 void rpc_destroy_authunix(void)
202 mempool_destroy(unix_pool);
205 const struct rpc_authops authunix_ops = {
206 .owner = THIS_MODULE,
207 .au_flavor = RPC_AUTH_UNIX,
209 .create = unx_create,
210 .destroy = unx_destroy,
211 .lookup_cred = unx_lookup_cred,
215 struct rpc_auth unix_auth = {
216 .au_cslack = UNX_CALLSLACK,
217 .au_rslack = NUL_REPLYSLACK,
218 .au_verfsize = NUL_REPLYSLACK,
219 .au_ops = &authunix_ops,
220 .au_flavor = RPC_AUTH_UNIX,
221 .au_count = REFCOUNT_INIT(1),
225 const struct rpc_credops unix_credops = {
226 .cr_name = "AUTH_UNIX",
227 .crdestroy = unx_destroy_cred,
228 .crmatch = unx_match,
229 .crmarshal = unx_marshal,
230 .crwrap_req = rpcauth_wrap_req_encode,
231 .crrefresh = unx_refresh,
232 .crvalidate = unx_validate,
233 .crunwrap_resp = rpcauth_unwrap_resp_decode,