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

  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};