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/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>
 16
 17#define NFS_NGROUPS	16
 18
 19struct unx_cred {
 20	struct rpc_cred		uc_base;
 21	kgid_t			uc_gid;
 22	kgid_t			uc_gids[NFS_NGROUPS];
 23};
 24#define uc_uid			uc_base.cr_uid
 25
 26#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 27# define RPCDBG_FACILITY	RPCDBG_AUTH
 28#endif
 29
 30static struct rpc_auth		unix_auth;
 31static const struct rpc_credops	unix_credops;
 32
 33static struct rpc_auth *
 34unx_create(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
 35{
 36	dprintk("RPC:       creating UNIX authenticator for client %p\n",
 37			clnt);
 38	atomic_inc(&unix_auth.au_count);
 39	return &unix_auth;
 40}
 41
 42static void
 43unx_destroy(struct rpc_auth *auth)
 44{
 45	dprintk("RPC:       destroying UNIX authenticator %p\n", auth);
 46	rpcauth_clear_credcache(auth->au_credcache);
 47}
 48
 
 
 
 
 
 
 
 
 49/*
 50 * Lookup AUTH_UNIX creds for current process
 51 */
 52static struct rpc_cred *
 53unx_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
 54{
 55	return rpcauth_lookup_credcache(auth, acred, flags);
 56}
 57
 58static struct rpc_cred *
 59unx_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
 60{
 61	struct unx_cred	*cred;
 62	unsigned int groups = 0;
 63	unsigned int i;
 64
 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));
 68
 69	if (!(cred = kmalloc(sizeof(*cred), GFP_NOFS)))
 70		return ERR_PTR(-ENOMEM);
 71
 72	rpcauth_init_cred(&cred->uc_base, acred, auth, &unix_credops);
 73	cred->uc_base.cr_flags = 1UL << RPCAUTH_CRED_UPTODATE;
 74
 75	if (acred->group_info != NULL)
 76		groups = acred->group_info->ngroups;
 77	if (groups > NFS_NGROUPS)
 78		groups = NFS_NGROUPS;
 79
 80	cred->uc_gid = acred->gid;
 81	for (i = 0; i < groups; i++)
 82		cred->uc_gids[i] = GROUP_AT(acred->group_info, i);
 83	if (i < NFS_NGROUPS)
 84		cred->uc_gids[i] = INVALID_GID;
 85
 86	return &cred->uc_base;
 87}
 88
 89static void
 90unx_free_cred(struct unx_cred *unx_cred)
 91{
 92	dprintk("RPC:       unx_free_cred %p\n", unx_cred);
 93	kfree(unx_cred);
 94}
 95
 96static void
 97unx_free_cred_callback(struct rcu_head *head)
 98{
 99	struct unx_cred *unx_cred = container_of(head, struct unx_cred, uc_base.cr_rcu);
100	unx_free_cred(unx_cred);
101}
102
103static void
104unx_destroy_cred(struct rpc_cred *cred)
105{
106	call_rcu(&cred->cr_rcu, unx_free_cred_callback);
107}
108
109/*
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).
113 */
114static int
115unx_match(struct auth_cred *acred, struct rpc_cred *rcred, int flags)
116{
117	struct unx_cred	*cred = container_of(rcred, struct unx_cred, uc_base);
118	unsigned int groups = 0;
119	unsigned int i;
120
121
122	if (!uid_eq(cred->uc_uid, acred->uid) || !gid_eq(cred->uc_gid, acred->gid))
123		return 0;
124
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)))
131			return 0;
132	if (groups < NFS_NGROUPS && gid_valid(cred->uc_gids[groups]))
133		return 0;
134	return 1;
135}
136
137/*
138 * Marshal credentials.
139 * Maybe we should keep a cached credential for performance reasons.
140 */
141static __be32 *
142unx_marshal(struct rpc_task *task, __be32 *p)
143{
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);
146	__be32		*base, *hold;
147	int		i;
148
149	*p++ = htonl(RPC_AUTH_UNIX);
150	base = p++;
151	*p++ = htonl(jiffies/HZ);
152
153	/*
154	 * Copy the UTS nodename captured when the client was created.
155	 */
156	p = xdr_encode_array(p, clnt->cl_nodename, clnt->cl_nodelen);
157
158	*p++ = htonl((u32) from_kuid(&init_user_ns, cred->uc_uid));
159	*p++ = htonl((u32) from_kgid(&init_user_ns, cred->uc_gid));
160	hold = p++;
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 */
165
166	*p++ = htonl(RPC_AUTH_NULL);
167	*p++ = htonl(0);
168
169	return p;
170}
171
172/*
173 * Refresh credentials. This is a no-op for AUTH_UNIX
174 */
175static int
176unx_refresh(struct rpc_task *task)
177{
178	set_bit(RPCAUTH_CRED_UPTODATE, &task->tk_rqstp->rq_cred->cr_flags);
179	return 0;
180}
181
182static __be32 *
183unx_validate(struct rpc_task *task, __be32 *p)
184{
185	rpc_authflavor_t	flavor;
186	u32			size;
187
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);
194	}
195
196	size = ntohl(*p++);
197	if (size > RPC_MAX_AUTH_SIZE) {
198		printk("RPC: giant verf size: %u\n", size);
199		return ERR_PTR(-EIO);
200	}
201	task->tk_rqstp->rq_cred->cr_auth->au_rslack = (size >> 2) + 2;
202	p += (size >> 2);
203
204	return p;
205}
206
207int __init rpc_init_authunix(void)
208{
209	return rpcauth_init_credcache(&unix_auth);
210}
211
212void rpc_destroy_authunix(void)
213{
214	rpcauth_destroy_credcache(&unix_auth);
215}
216
217const struct rpc_authops authunix_ops = {
218	.owner		= THIS_MODULE,
219	.au_flavor	= RPC_AUTH_UNIX,
220	.au_name	= "UNIX",
221	.create		= unx_create,
222	.destroy	= unx_destroy,
 
223	.lookup_cred	= unx_lookup_cred,
224	.crcreate	= unx_create_cred,
225};
226
227static
228struct 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),
234};
235
236static
237const 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,
245};

  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * linux/net/sunrpc/auth_unix.c
  4 *
  5 * UNIX-style authentication; no AUTH_SHORT support
  6 *
  7 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
  8 */
  9
 10#include <linux/slab.h>
 11#include <linux/types.h>
 12#include <linux/sched.h>
 13#include <linux/module.h>
 14#include <linux/sunrpc/clnt.h>
 15#include <linux/sunrpc/auth.h>
 16#include <linux/user_namespace.h>
 17
 
 
 18struct unx_cred {
 19	struct rpc_cred		uc_base;
 20	kgid_t			uc_gid;
 21	kgid_t			uc_gids[UNX_NGROUPS];
 22};
 23#define uc_uid			uc_base.cr_uid
 24
 25#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
 26# define RPCDBG_FACILITY	RPCDBG_AUTH
 27#endif
 28
 29static struct rpc_auth		unix_auth;
 30static const struct rpc_credops	unix_credops;
 31
 32static struct rpc_auth *
 33unx_create(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
 34{
 35	dprintk("RPC:       creating UNIX authenticator for client %p\n",
 36			clnt);
 37	atomic_inc(&unix_auth.au_count);
 38	return &unix_auth;
 39}
 40
 41static void
 42unx_destroy(struct rpc_auth *auth)
 43{
 44	dprintk("RPC:       destroying UNIX authenticator %p\n", auth);
 45	rpcauth_clear_credcache(auth->au_credcache);
 46}
 47
 48static int
 49unx_hash_cred(struct auth_cred *acred, unsigned int hashbits)
 50{
 51	return hash_64(from_kgid(&init_user_ns, acred->gid) |
 52		((u64)from_kuid(&init_user_ns, acred->uid) <<
 53			(sizeof(gid_t) * 8)), hashbits);
 54}
 55
 56/*
 57 * Lookup AUTH_UNIX creds for current process
 58 */
 59static struct rpc_cred *
 60unx_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
 61{
 62	return rpcauth_lookup_credcache(auth, acred, flags, GFP_NOFS);
 63}
 64
 65static struct rpc_cred *
 66unx_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags, gfp_t gfp)
 67{
 68	struct unx_cred	*cred;
 69	unsigned int groups = 0;
 70	unsigned int i;
 71
 72	dprintk("RPC:       allocating UNIX cred for uid %d gid %d\n",
 73			from_kuid(&init_user_ns, acred->uid),
 74			from_kgid(&init_user_ns, acred->gid));
 75
 76	if (!(cred = kmalloc(sizeof(*cred), gfp)))
 77		return ERR_PTR(-ENOMEM);
 78
 79	rpcauth_init_cred(&cred->uc_base, acred, auth, &unix_credops);
 80	cred->uc_base.cr_flags = 1UL << RPCAUTH_CRED_UPTODATE;
 81
 82	if (acred->group_info != NULL)
 83		groups = acred->group_info->ngroups;
 84	if (groups > UNX_NGROUPS)
 85		groups = UNX_NGROUPS;
 86
 87	cred->uc_gid = acred->gid;
 88	for (i = 0; i < groups; i++)
 89		cred->uc_gids[i] = acred->group_info->gid[i];
 90	if (i < UNX_NGROUPS)
 91		cred->uc_gids[i] = INVALID_GID;
 92
 93	return &cred->uc_base;
 94}
 95
 96static void
 97unx_free_cred(struct unx_cred *unx_cred)
 98{
 99	dprintk("RPC:       unx_free_cred %p\n", unx_cred);
100	kfree(unx_cred);
101}
102
103static void
104unx_free_cred_callback(struct rcu_head *head)
105{
106	struct unx_cred *unx_cred = container_of(head, struct unx_cred, uc_base.cr_rcu);
107	unx_free_cred(unx_cred);
108}
109
110static void
111unx_destroy_cred(struct rpc_cred *cred)
112{
113	call_rcu(&cred->cr_rcu, unx_free_cred_callback);
114}
115
116/*
117 * Match credentials against current process creds.
118 * The root_override argument takes care of cases where the caller may
119 * request root creds (e.g. for NFS swapping).
120 */
121static int
122unx_match(struct auth_cred *acred, struct rpc_cred *rcred, int flags)
123{
124	struct unx_cred	*cred = container_of(rcred, struct unx_cred, uc_base);
125	unsigned int groups = 0;
126	unsigned int i;
127
128
129	if (!uid_eq(cred->uc_uid, acred->uid) || !gid_eq(cred->uc_gid, acred->gid))
130		return 0;
131
132	if (acred->group_info != NULL)
133		groups = acred->group_info->ngroups;
134	if (groups > UNX_NGROUPS)
135		groups = UNX_NGROUPS;
136	for (i = 0; i < groups ; i++)
137		if (!gid_eq(cred->uc_gids[i], acred->group_info->gid[i]))
138			return 0;
139	if (groups < UNX_NGROUPS && gid_valid(cred->uc_gids[groups]))
140		return 0;
141	return 1;
142}
143
144/*
145 * Marshal credentials.
146 * Maybe we should keep a cached credential for performance reasons.
147 */
148static __be32 *
149unx_marshal(struct rpc_task *task, __be32 *p)
150{
151	struct rpc_clnt	*clnt = task->tk_client;
152	struct unx_cred	*cred = container_of(task->tk_rqstp->rq_cred, struct unx_cred, uc_base);
153	__be32		*base, *hold;
154	int		i;
155
156	*p++ = htonl(RPC_AUTH_UNIX);
157	base = p++;
158	*p++ = htonl(jiffies/HZ);
159
160	/*
161	 * Copy the UTS nodename captured when the client was created.
162	 */
163	p = xdr_encode_array(p, clnt->cl_nodename, clnt->cl_nodelen);
164
165	*p++ = htonl((u32) from_kuid(&init_user_ns, cred->uc_uid));
166	*p++ = htonl((u32) from_kgid(&init_user_ns, cred->uc_gid));
167	hold = p++;
168	for (i = 0; i < UNX_NGROUPS && gid_valid(cred->uc_gids[i]); i++)
169		*p++ = htonl((u32) from_kgid(&init_user_ns, cred->uc_gids[i]));
170	*hold = htonl(p - hold - 1);		/* gid array length */
171	*base = htonl((p - base - 1) << 2);	/* cred length */
172
173	*p++ = htonl(RPC_AUTH_NULL);
174	*p++ = htonl(0);
175
176	return p;
177}
178
179/*
180 * Refresh credentials. This is a no-op for AUTH_UNIX
181 */
182static int
183unx_refresh(struct rpc_task *task)
184{
185	set_bit(RPCAUTH_CRED_UPTODATE, &task->tk_rqstp->rq_cred->cr_flags);
186	return 0;
187}
188
189static __be32 *
190unx_validate(struct rpc_task *task, __be32 *p)
191{
192	rpc_authflavor_t	flavor;
193	u32			size;
194
195	flavor = ntohl(*p++);
196	if (flavor != RPC_AUTH_NULL &&
197	    flavor != RPC_AUTH_UNIX &&
198	    flavor != RPC_AUTH_SHORT) {
199		printk("RPC: bad verf flavor: %u\n", flavor);
200		return ERR_PTR(-EIO);
201	}
202
203	size = ntohl(*p++);
204	if (size > RPC_MAX_AUTH_SIZE) {
205		printk("RPC: giant verf size: %u\n", size);
206		return ERR_PTR(-EIO);
207	}
208	task->tk_rqstp->rq_cred->cr_auth->au_rslack = (size >> 2) + 2;
209	p += (size >> 2);
210
211	return p;
212}
213
214int __init rpc_init_authunix(void)
215{
216	return rpcauth_init_credcache(&unix_auth);
217}
218
219void rpc_destroy_authunix(void)
220{
221	rpcauth_destroy_credcache(&unix_auth);
222}
223
224const struct rpc_authops authunix_ops = {
225	.owner		= THIS_MODULE,
226	.au_flavor	= RPC_AUTH_UNIX,
227	.au_name	= "UNIX",
228	.create		= unx_create,
229	.destroy	= unx_destroy,
230	.hash_cred	= unx_hash_cred,
231	.lookup_cred	= unx_lookup_cred,
232	.crcreate	= unx_create_cred,
233};
234
235static
236struct rpc_auth		unix_auth = {
237	.au_cslack	= UNX_CALLSLACK,
238	.au_rslack	= NUL_REPLYSLACK,
239	.au_flags	= RPCAUTH_AUTH_NO_CRKEY_TIMEOUT,
240	.au_ops		= &authunix_ops,
241	.au_flavor	= RPC_AUTH_UNIX,
242	.au_count	= ATOMIC_INIT(0),
243};
244
245static
246const struct rpc_credops unix_credops = {
247	.cr_name	= "AUTH_UNIX",
248	.crdestroy	= unx_destroy_cred,
249	.crbind		= rpcauth_generic_bind_cred,
250	.crmatch	= unx_match,
251	.crmarshal	= unx_marshal,
252	.crrefresh	= unx_refresh,
253	.crvalidate	= unx_validate,
254};