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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
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
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
100
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
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;
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
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
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};
236
