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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/mempool.h>
15#include <linux/sunrpc/clnt.h>
16#include <linux/sunrpc/auth.h>
17#include <linux/user_namespace.h>
18
19
20#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
21# define RPCDBG_FACILITY RPCDBG_AUTH
22#endif
23
24static struct rpc_auth unix_auth;
25static const struct rpc_credops unix_credops;
26static mempool_t *unix_pool;
27
28static struct rpc_auth *
29unx_create(const struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
30{
31 refcount_inc(&unix_auth.au_count);
32 return &unix_auth;
33}
34
35static void
36unx_destroy(struct rpc_auth *auth)
37{
38}
39
40/*
41 * Lookup AUTH_UNIX creds for current process
42 */
43static struct rpc_cred *
44unx_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
45{
46 struct rpc_cred *ret = mempool_alloc(unix_pool, GFP_NOFS);
47
48 rpcauth_init_cred(ret, acred, auth, &unix_credops);
49 ret->cr_flags = 1UL << RPCAUTH_CRED_UPTODATE;
50 return ret;
51}
52
53static void
54unx_free_cred_callback(struct rcu_head *head)
55{
56 struct rpc_cred *rpc_cred = container_of(head, struct rpc_cred, cr_rcu);
57
58 put_cred(rpc_cred->cr_cred);
59 mempool_free(rpc_cred, unix_pool);
60}
61
62static void
63unx_destroy_cred(struct rpc_cred *cred)
64{
65 call_rcu(&cred->cr_rcu, unx_free_cred_callback);
66}
67
68/*
69 * Match credentials against current the auth_cred.
70 */
71static int
72unx_match(struct auth_cred *acred, struct rpc_cred *cred, int flags)
73{
74 unsigned int groups = 0;
75 unsigned int i;
76
77 if (cred->cr_cred == acred->cred)
78 return 1;
79
80 if (!uid_eq(cred->cr_cred->fsuid, acred->cred->fsuid) || !gid_eq(cred->cr_cred->fsgid, acred->cred->fsgid))
81 return 0;
82
83 if (acred->cred->group_info != NULL)
84 groups = acred->cred->group_info->ngroups;
85 if (groups > UNX_NGROUPS)
86 groups = UNX_NGROUPS;
87 if (cred->cr_cred->group_info == NULL)
88 return groups == 0;
89 if (groups != cred->cr_cred->group_info->ngroups)
90 return 0;
91
92 for (i = 0; i < groups ; i++)
93 if (!gid_eq(cred->cr_cred->group_info->gid[i], acred->cred->group_info->gid[i]))
94 return 0;
95 return 1;
96}
97
98/*
99 * Marshal credentials.
100 * Maybe we should keep a cached credential for performance reasons.
101 */
102static int
103unx_marshal(struct rpc_task *task, struct xdr_stream *xdr)
104{
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;
108 int i;
109 struct group_info *gi = cred->cr_cred->group_info;
110 struct user_namespace *userns = clnt->cl_cred ?
111 clnt->cl_cred->user_ns : &init_user_ns;
112
113 /* Credential */
114
115 p = xdr_reserve_space(xdr, 3 * sizeof(*p));
116 if (!p)
117 goto marshal_failed;
118 *p++ = rpc_auth_unix;
119 cred_len = p++;
120 *p++ = xdr_zero; /* stamp */
121 if (xdr_stream_encode_opaque(xdr, clnt->cl_nodename,
122 clnt->cl_nodelen) < 0)
123 goto marshal_failed;
124 p = xdr_reserve_space(xdr, 3 * sizeof(*p));
125 if (!p)
126 goto marshal_failed;
127 *p++ = cpu_to_be32(from_kuid_munged(userns, cred->cr_cred->fsuid));
128 *p++ = cpu_to_be32(from_kgid_munged(userns, cred->cr_cred->fsgid));
129
130 gidarr_len = p++;
131 if (gi)
132 for (i = 0; i < UNX_NGROUPS && i < gi->ngroups; i++)
133 *p++ = cpu_to_be32(from_kgid_munged(userns, gi->gid[i]));
134 *gidarr_len = cpu_to_be32(p - gidarr_len - 1);
135 *cred_len = cpu_to_be32((p - cred_len - 1) << 2);
136 p = xdr_reserve_space(xdr, (p - gidarr_len - 1) << 2);
137 if (!p)
138 goto marshal_failed;
139
140 /* Verifier */
141
142 p = xdr_reserve_space(xdr, 2 * sizeof(*p));
143 if (!p)
144 goto marshal_failed;
145 *p++ = rpc_auth_null;
146 *p = xdr_zero;
147
148 return 0;
149
150marshal_failed:
151 return -EMSGSIZE;
152}
153
154/*
155 * Refresh credentials. This is a no-op for AUTH_UNIX
156 */
157static int
158unx_refresh(struct rpc_task *task)
159{
160 set_bit(RPCAUTH_CRED_UPTODATE, &task->tk_rqstp->rq_cred->cr_flags);
161 return 0;
162}
163
164static int
165unx_validate(struct rpc_task *task, struct xdr_stream *xdr)
166{
167 struct rpc_auth *auth = task->tk_rqstp->rq_cred->cr_auth;
168 __be32 *p;
169 u32 size;
170
171 p = xdr_inline_decode(xdr, 2 * sizeof(*p));
172 if (!p)
173 return -EIO;
174 switch (*p++) {
175 case rpc_auth_null:
176 case rpc_auth_unix:
177 case rpc_auth_short:
178 break;
179 default:
180 return -EIO;
181 }
182 size = be32_to_cpup(p);
183 if (size > RPC_MAX_AUTH_SIZE)
184 return -EIO;
185 p = xdr_inline_decode(xdr, size);
186 if (!p)
187 return -EIO;
188
189 auth->au_verfsize = XDR_QUADLEN(size) + 2;
190 auth->au_rslack = XDR_QUADLEN(size) + 2;
191 auth->au_ralign = XDR_QUADLEN(size) + 2;
192 return 0;
193}
194
195int __init rpc_init_authunix(void)
196{
197 unix_pool = mempool_create_kmalloc_pool(16, sizeof(struct rpc_cred));
198 return unix_pool ? 0 : -ENOMEM;
199}
200
201void rpc_destroy_authunix(void)
202{
203 mempool_destroy(unix_pool);
204}
205
206const struct rpc_authops authunix_ops = {
207 .owner = THIS_MODULE,
208 .au_flavor = RPC_AUTH_UNIX,
209 .au_name = "UNIX",
210 .create = unx_create,
211 .destroy = unx_destroy,
212 .lookup_cred = unx_lookup_cred,
213};
214
215static
216struct rpc_auth unix_auth = {
217 .au_cslack = UNX_CALLSLACK,
218 .au_rslack = NUL_REPLYSLACK,
219 .au_verfsize = NUL_REPLYSLACK,
220 .au_ops = &authunix_ops,
221 .au_flavor = RPC_AUTH_UNIX,
222 .au_count = REFCOUNT_INIT(1),
223};
224
225static
226const struct rpc_credops unix_credops = {
227 .cr_name = "AUTH_UNIX",
228 .crdestroy = unx_destroy_cred,
229 .crmatch = unx_match,
230 .crmarshal = unx_marshal,
231 .crwrap_req = rpcauth_wrap_req_encode,
232 .crrefresh = unx_refresh,
233 .crvalidate = unx_validate,
234 .crunwrap_resp = rpcauth_unwrap_resp_decode,
235};
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};