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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 *unx_lookup_cred(struct rpc_auth *auth,
44 struct auth_cred *acred, int flags)
45{
46 struct rpc_cred *ret;
47
48 ret = kmalloc(sizeof(*ret), rpc_task_gfp_mask());
49 if (!ret) {
50 if (!(flags & RPCAUTH_LOOKUP_ASYNC))
51 return ERR_PTR(-ENOMEM);
52 ret = mempool_alloc(unix_pool, GFP_NOWAIT);
53 if (!ret)
54 return ERR_PTR(-ENOMEM);
55 }
56 rpcauth_init_cred(ret, acred, auth, &unix_credops);
57 ret->cr_flags = 1UL << RPCAUTH_CRED_UPTODATE;
58 return ret;
59}
60
61static void
62unx_free_cred_callback(struct rcu_head *head)
63{
64 struct rpc_cred *rpc_cred = container_of(head, struct rpc_cred, cr_rcu);
65
66 put_cred(rpc_cred->cr_cred);
67 mempool_free(rpc_cred, unix_pool);
68}
69
70static void
71unx_destroy_cred(struct rpc_cred *cred)
72{
73 call_rcu(&cred->cr_rcu, unx_free_cred_callback);
74}
75
76/*
77 * Match credentials against current the auth_cred.
78 */
79static int
80unx_match(struct auth_cred *acred, struct rpc_cred *cred, int flags)
81{
82 unsigned int groups = 0;
83 unsigned int i;
84
85 if (cred->cr_cred == acred->cred)
86 return 1;
87
88 if (!uid_eq(cred->cr_cred->fsuid, acred->cred->fsuid) || !gid_eq(cred->cr_cred->fsgid, acred->cred->fsgid))
89 return 0;
90
91 if (acred->cred->group_info != NULL)
92 groups = acred->cred->group_info->ngroups;
93 if (groups > UNX_NGROUPS)
94 groups = UNX_NGROUPS;
95 if (cred->cr_cred->group_info == NULL)
96 return groups == 0;
97 if (groups != cred->cr_cred->group_info->ngroups)
98 return 0;
99
100 for (i = 0; i < groups ; i++)
101 if (!gid_eq(cred->cr_cred->group_info->gid[i], acred->cred->group_info->gid[i]))
102 return 0;
103 return 1;
104}
105
106/*
107 * Marshal credentials.
108 * Maybe we should keep a cached credential for performance reasons.
109 */
110static int
111unx_marshal(struct rpc_task *task, struct xdr_stream *xdr)
112{
113 struct rpc_clnt *clnt = task->tk_client;
114 struct rpc_cred *cred = task->tk_rqstp->rq_cred;
115 __be32 *p, *cred_len, *gidarr_len;
116 int i;
117 struct group_info *gi = cred->cr_cred->group_info;
118 struct user_namespace *userns = clnt->cl_cred ?
119 clnt->cl_cred->user_ns : &init_user_ns;
120
121 /* Credential */
122
123 p = xdr_reserve_space(xdr, 3 * sizeof(*p));
124 if (!p)
125 goto marshal_failed;
126 *p++ = rpc_auth_unix;
127 cred_len = p++;
128 *p++ = xdr_zero; /* stamp */
129 if (xdr_stream_encode_opaque(xdr, clnt->cl_nodename,
130 clnt->cl_nodelen) < 0)
131 goto marshal_failed;
132 p = xdr_reserve_space(xdr, 3 * sizeof(*p));
133 if (!p)
134 goto marshal_failed;
135 *p++ = cpu_to_be32(from_kuid_munged(userns, cred->cr_cred->fsuid));
136 *p++ = cpu_to_be32(from_kgid_munged(userns, cred->cr_cred->fsgid));
137
138 gidarr_len = p++;
139 if (gi)
140 for (i = 0; i < UNX_NGROUPS && i < gi->ngroups; i++)
141 *p++ = cpu_to_be32(from_kgid_munged(userns, gi->gid[i]));
142 *gidarr_len = cpu_to_be32(p - gidarr_len - 1);
143 *cred_len = cpu_to_be32((p - cred_len - 1) << 2);
144 p = xdr_reserve_space(xdr, (p - gidarr_len - 1) << 2);
145 if (!p)
146 goto marshal_failed;
147
148 /* Verifier */
149
150 p = xdr_reserve_space(xdr, 2 * sizeof(*p));
151 if (!p)
152 goto marshal_failed;
153 *p++ = rpc_auth_null;
154 *p = xdr_zero;
155
156 return 0;
157
158marshal_failed:
159 return -EMSGSIZE;
160}
161
162/*
163 * Refresh credentials. This is a no-op for AUTH_UNIX
164 */
165static int
166unx_refresh(struct rpc_task *task)
167{
168 set_bit(RPCAUTH_CRED_UPTODATE, &task->tk_rqstp->rq_cred->cr_flags);
169 return 0;
170}
171
172static int
173unx_validate(struct rpc_task *task, struct xdr_stream *xdr)
174{
175 struct rpc_auth *auth = task->tk_rqstp->rq_cred->cr_auth;
176 __be32 *p;
177 u32 size;
178
179 p = xdr_inline_decode(xdr, 2 * sizeof(*p));
180 if (!p)
181 return -EIO;
182 switch (*p++) {
183 case rpc_auth_null:
184 case rpc_auth_unix:
185 case rpc_auth_short:
186 break;
187 default:
188 return -EIO;
189 }
190 size = be32_to_cpup(p);
191 if (size > RPC_MAX_AUTH_SIZE)
192 return -EIO;
193 p = xdr_inline_decode(xdr, size);
194 if (!p)
195 return -EIO;
196
197 auth->au_verfsize = XDR_QUADLEN(size) + 2;
198 auth->au_rslack = XDR_QUADLEN(size) + 2;
199 auth->au_ralign = XDR_QUADLEN(size) + 2;
200 return 0;
201}
202
203int __init rpc_init_authunix(void)
204{
205 unix_pool = mempool_create_kmalloc_pool(16, sizeof(struct rpc_cred));
206 return unix_pool ? 0 : -ENOMEM;
207}
208
209void rpc_destroy_authunix(void)
210{
211 mempool_destroy(unix_pool);
212}
213
214const struct rpc_authops authunix_ops = {
215 .owner = THIS_MODULE,
216 .au_flavor = RPC_AUTH_UNIX,
217 .au_name = "UNIX",
218 .create = unx_create,
219 .destroy = unx_destroy,
220 .lookup_cred = unx_lookup_cred,
221};
222
223static
224struct rpc_auth unix_auth = {
225 .au_cslack = UNX_CALLSLACK,
226 .au_rslack = NUL_REPLYSLACK,
227 .au_verfsize = NUL_REPLYSLACK,
228 .au_ops = &authunix_ops,
229 .au_flavor = RPC_AUTH_UNIX,
230 .au_count = REFCOUNT_INIT(1),
231};
232
233static
234const struct rpc_credops unix_credops = {
235 .cr_name = "AUTH_UNIX",
236 .crdestroy = unx_destroy_cred,
237 .crmatch = unx_match,
238 .crmarshal = unx_marshal,
239 .crwrap_req = rpcauth_wrap_req_encode,
240 .crrefresh = unx_refresh,
241 .crvalidate = unx_validate,
242 .crunwrap_resp = rpcauth_unwrap_resp_decode,
243};
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
16#define NFS_NGROUPS 16
17
18struct unx_cred {
19 struct rpc_cred uc_base;
20 gid_t uc_gid;
21 gid_t uc_gids[NFS_NGROUPS];
22};
23#define uc_uid uc_base.cr_uid
24
25#define UNX_WRITESLACK (21 + (UNX_MAXNODENAME >> 2))
26
27#ifdef RPC_DEBUG
28# define RPCDBG_FACILITY RPCDBG_AUTH
29#endif
30
31static struct rpc_auth unix_auth;
32static const struct rpc_credops unix_credops;
33
34static struct rpc_auth *
35unx_create(struct rpc_clnt *clnt, rpc_authflavor_t flavor)
36{
37 dprintk("RPC: creating UNIX authenticator for client %p\n",
38 clnt);
39 atomic_inc(&unix_auth.au_count);
40 return &unix_auth;
41}
42
43static void
44unx_destroy(struct rpc_auth *auth)
45{
46 dprintk("RPC: destroying UNIX authenticator %p\n", auth);
47 rpcauth_clear_credcache(auth->au_credcache);
48}
49
50/*
51 * Lookup AUTH_UNIX creds for current process
52 */
53static struct rpc_cred *
54unx_lookup_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
55{
56 return rpcauth_lookup_credcache(auth, acred, flags);
57}
58
59static struct rpc_cred *
60unx_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags)
61{
62 struct unx_cred *cred;
63 unsigned int groups = 0;
64 unsigned int i;
65
66 dprintk("RPC: allocating UNIX cred for uid %d gid %d\n",
67 acred->uid, 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] = NOGROUP;
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 (cred->uc_uid != acred->uid || 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 (cred->uc_gids[i] != GROUP_AT(acred->group_info, i))
131 return 0;
132 return 1;
133}
134
135/*
136 * Marshal credentials.
137 * Maybe we should keep a cached credential for performance reasons.
138 */
139static __be32 *
140unx_marshal(struct rpc_task *task, __be32 *p)
141{
142 struct rpc_clnt *clnt = task->tk_client;
143 struct unx_cred *cred = container_of(task->tk_rqstp->rq_cred, struct unx_cred, uc_base);
144 __be32 *base, *hold;
145 int i;
146
147 *p++ = htonl(RPC_AUTH_UNIX);
148 base = p++;
149 *p++ = htonl(jiffies/HZ);
150
151 /*
152 * Copy the UTS nodename captured when the client was created.
153 */
154 p = xdr_encode_array(p, clnt->cl_nodename, clnt->cl_nodelen);
155
156 *p++ = htonl((u32) cred->uc_uid);
157 *p++ = htonl((u32) cred->uc_gid);
158 hold = p++;
159 for (i = 0; i < 16 && cred->uc_gids[i] != (gid_t) NOGROUP; i++)
160 *p++ = htonl((u32) cred->uc_gids[i]);
161 *hold = htonl(p - hold - 1); /* gid array length */
162 *base = htonl((p - base - 1) << 2); /* cred length */
163
164 *p++ = htonl(RPC_AUTH_NULL);
165 *p++ = htonl(0);
166
167 return p;
168}
169
170/*
171 * Refresh credentials. This is a no-op for AUTH_UNIX
172 */
173static int
174unx_refresh(struct rpc_task *task)
175{
176 set_bit(RPCAUTH_CRED_UPTODATE, &task->tk_rqstp->rq_cred->cr_flags);
177 return 0;
178}
179
180static __be32 *
181unx_validate(struct rpc_task *task, __be32 *p)
182{
183 rpc_authflavor_t flavor;
184 u32 size;
185
186 flavor = ntohl(*p++);
187 if (flavor != RPC_AUTH_NULL &&
188 flavor != RPC_AUTH_UNIX &&
189 flavor != RPC_AUTH_SHORT) {
190 printk("RPC: bad verf flavor: %u\n", flavor);
191 return NULL;
192 }
193
194 size = ntohl(*p++);
195 if (size > RPC_MAX_AUTH_SIZE) {
196 printk("RPC: giant verf size: %u\n", size);
197 return NULL;
198 }
199 task->tk_rqstp->rq_cred->cr_auth->au_rslack = (size >> 2) + 2;
200 p += (size >> 2);
201
202 return p;
203}
204
205int __init rpc_init_authunix(void)
206{
207 return rpcauth_init_credcache(&unix_auth);
208}
209
210void rpc_destroy_authunix(void)
211{
212 rpcauth_destroy_credcache(&unix_auth);
213}
214
215const struct rpc_authops authunix_ops = {
216 .owner = THIS_MODULE,
217 .au_flavor = RPC_AUTH_UNIX,
218 .au_name = "UNIX",
219 .create = unx_create,
220 .destroy = unx_destroy,
221 .lookup_cred = unx_lookup_cred,
222 .crcreate = unx_create_cred,
223};
224
225static
226struct rpc_auth unix_auth = {
227 .au_cslack = UNX_WRITESLACK,
228 .au_rslack = 2, /* assume AUTH_NULL verf */
229 .au_ops = &authunix_ops,
230 .au_flavor = RPC_AUTH_UNIX,
231 .au_count = ATOMIC_INIT(0),
232};
233
234static
235const struct rpc_credops unix_credops = {
236 .cr_name = "AUTH_UNIX",
237 .crdestroy = unx_destroy_cred,
238 .crbind = rpcauth_generic_bind_cred,
239 .crmatch = unx_match,
240 .crmarshal = unx_marshal,
241 .crrefresh = unx_refresh,
242 .crvalidate = unx_validate,
243};