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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
Tejun Heo5a0e3ad2010-03-24 17:04:11 +09009#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070010#include <linux/types.h>
11#include <linux/sched.h>
12#include <linux/module.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070013#include <linux/sunrpc/clnt.h>
14#include <linux/sunrpc/auth.h>
Eric W. Biedermanae2975b2011-11-14 15:56:38 -080015#include <linux/user_namespace.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070016
17#define NFS_NGROUPS 16
18
19struct unx_cred {
20 struct rpc_cred uc_base;
Eric W. Biederman7eaf0402013-02-01 16:31:17 -080021 kgid_t uc_gid;
22 kgid_t uc_gids[NFS_NGROUPS];
Linus Torvalds1da177e2005-04-16 15:20:36 -070023};
24#define uc_uid uc_base.cr_uid
Linus Torvalds1da177e2005-04-16 15:20:36 -070025
Jeff Laytonf895b252014-11-17 16:58:04 -050026#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
Linus Torvalds1da177e2005-04-16 15:20:36 -070027# define RPCDBG_FACILITY RPCDBG_AUTH
28#endif
29
30static struct rpc_auth unix_auth;
Trond Myklebustf1c0a862007-06-23 20:17:58 -040031static const struct rpc_credops unix_credops;
Linus Torvalds1da177e2005-04-16 15:20:36 -070032
33static struct rpc_auth *
Trond Myklebustc2190662013-08-26 19:23:04 -040034unx_create(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
Linus Torvalds1da177e2005-04-16 15:20:36 -070035{
Chuck Lever46121cf2007-01-31 12:14:08 -050036 dprintk("RPC: creating UNIX authenticator for client %p\n",
37 clnt);
Trond Myklebustf5c21872007-06-25 17:11:20 -040038 atomic_inc(&unix_auth.au_count);
Linus Torvalds1da177e2005-04-16 15:20:36 -070039 return &unix_auth;
40}
41
42static void
43unx_destroy(struct rpc_auth *auth)
44{
Chuck Lever46121cf2007-01-31 12:14:08 -050045 dprintk("RPC: destroying UNIX authenticator %p\n", auth);
Trond Myklebust3ab9bb72007-06-09 15:41:42 -040046 rpcauth_clear_credcache(auth->au_credcache);
Linus Torvalds1da177e2005-04-16 15:20:36 -070047}
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{
Jeff Layton3c6e0bc2016-04-21 20:51:54 -040055 return rpcauth_lookup_credcache(auth, acred, flags, GFP_NOFS);
Linus Torvalds1da177e2005-04-16 15:20:36 -070056}
57
58static struct rpc_cred *
Jeff Layton3c6e0bc2016-04-21 20:51:54 -040059unx_create_cred(struct rpc_auth *auth, struct auth_cred *acred, int flags, gfp_t gfp)
Linus Torvalds1da177e2005-04-16 15:20:36 -070060{
61 struct unx_cred *cred;
Trond Myklebustaf093832008-03-12 12:12:16 -040062 unsigned int groups = 0;
63 unsigned int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -070064
Chuck Lever46121cf2007-01-31 12:14:08 -050065 dprintk("RPC: allocating UNIX cred for uid %d gid %d\n",
Eric W. Biedermancdba3212013-02-01 17:10:52 -080066 from_kuid(&init_user_ns, acred->uid),
67 from_kgid(&init_user_ns, acred->gid));
Linus Torvalds1da177e2005-04-16 15:20:36 -070068
Jeff Layton3c6e0bc2016-04-21 20:51:54 -040069 if (!(cred = kmalloc(sizeof(*cred), gfp)))
Linus Torvalds1da177e2005-04-16 15:20:36 -070070 return ERR_PTR(-ENOMEM);
71
Trond Myklebust5fe47552007-06-23 19:55:31 -040072 rpcauth_init_cred(&cred->uc_base, acred, auth, &unix_credops);
Trond Myklebustfc432dd2007-06-25 10:15:15 -040073 cred->uc_base.cr_flags = 1UL << RPCAUTH_CRED_UPTODATE;
Linus Torvalds1da177e2005-04-16 15:20:36 -070074
Trond Myklebustaf093832008-03-12 12:12:16 -040075 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;
Eric W. Biederman9132adb2013-02-01 16:46:42 -080081 for (i = 0; i < groups; i++)
82 cred->uc_gids[i] = GROUP_AT(acred->group_info, i);
Trond Myklebustaf093832008-03-12 12:12:16 -040083 if (i < NFS_NGROUPS)
Eric W. Biedermanbf37f792013-02-01 15:55:38 -080084 cred->uc_gids[i] = INVALID_GID;
Linus Torvalds1da177e2005-04-16 15:20:36 -070085
Trond Myklebust696e38d2007-06-25 09:48:25 -040086 return &cred->uc_base;
Linus Torvalds1da177e2005-04-16 15:20:36 -070087}
88
89static void
Trond Myklebust31be5bf2007-06-24 15:55:26 -040090unx_free_cred(struct unx_cred *unx_cred)
Linus Torvalds1da177e2005-04-16 15:20:36 -070091{
Trond Myklebust31be5bf2007-06-24 15:55:26 -040092 dprintk("RPC: unx_free_cred %p\n", unx_cred);
93 kfree(unx_cred);
94}
Trond Myklebust696e38d2007-06-25 09:48:25 -040095
Trond Myklebust31be5bf2007-06-24 15:55:26 -040096static 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);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107}
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
Trond Myklebust8a317762006-02-01 12:18:36 -0500115unx_match(struct auth_cred *acred, struct rpc_cred *rcred, int flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116{
Trond Myklebust696e38d2007-06-25 09:48:25 -0400117 struct unx_cred *cred = container_of(rcred, struct unx_cred, uc_base);
Trond Myklebustaf093832008-03-12 12:12:16 -0400118 unsigned int groups = 0;
119 unsigned int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121
Eric W. Biederman0b4d51b2013-02-01 16:39:32 -0800122 if (!uid_eq(cred->uc_uid, acred->uid) || !gid_eq(cred->uc_gid, acred->gid))
Trond Myklebustaf093832008-03-12 12:12:16 -0400123 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124
Trond Myklebustaf093832008-03-12 12:12:16 -0400125 if (acred->group_info != NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126 groups = acred->group_info->ngroups;
Trond Myklebustaf093832008-03-12 12:12:16 -0400127 if (groups > NFS_NGROUPS)
128 groups = NFS_NGROUPS;
Eric W. Biederman9132adb2013-02-01 16:46:42 -0800129 for (i = 0; i < groups ; i++)
130 if (!gid_eq(cred->uc_gids[i], GROUP_AT(acred->group_info, i)))
Trond Myklebustaf093832008-03-12 12:12:16 -0400131 return 0;
Eric W. Biedermane572fc72013-02-01 17:18:04 -0800132 if (groups < NFS_NGROUPS && gid_valid(cred->uc_gids[groups]))
NeilBrowndc6f55e2011-10-25 10:25:49 +1100133 return 0;
Trond Myklebustaf093832008-03-12 12:12:16 -0400134 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135}
136
137/*
138 * Marshal credentials.
139 * Maybe we should keep a cached credential for performance reasons.
140 */
Alexey Dobriyand8ed0292006-09-26 22:29:38 -0700141static __be32 *
142unx_marshal(struct rpc_task *task, __be32 *p)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143{
144 struct rpc_clnt *clnt = task->tk_client;
Trond Myklebusta17c2152010-07-31 14:29:08 -0400145 struct unx_cred *cred = container_of(task->tk_rqstp->rq_cred, struct unx_cred, uc_base);
Alexey Dobriyand8ed0292006-09-26 22:29:38 -0700146 __be32 *base, *hold;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147 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
Eric W. Biedermana570abb2013-02-02 02:45:08 -0800158 *p++ = htonl((u32) from_kuid(&init_user_ns, cred->uc_uid));
159 *p++ = htonl((u32) from_kgid(&init_user_ns, cred->uc_gid));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160 hold = p++;
Eric W. Biedermane572fc72013-02-01 17:18:04 -0800161 for (i = 0; i < 16 && gid_valid(cred->uc_gids[i]); i++)
Eric W. Biedermana570abb2013-02-02 02:45:08 -0800162 *p++ = htonl((u32) from_kgid(&init_user_ns, cred->uc_gids[i]));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163 *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{
Trond Myklebusta17c2152010-07-31 14:29:08 -0400178 set_bit(RPCAUTH_CRED_UPTODATE, &task->tk_rqstp->rq_cred->cr_flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179 return 0;
180}
181
Alexey Dobriyand8ed0292006-09-26 22:29:38 -0700182static __be32 *
183unx_validate(struct rpc_task *task, __be32 *p)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184{
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);
Andy Adamson35fa5f72013-08-14 11:59:17 -0400193 return ERR_PTR(-EIO);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 }
195
196 size = ntohl(*p++);
197 if (size > RPC_MAX_AUTH_SIZE) {
198 printk("RPC: giant verf size: %u\n", size);
Andy Adamson35fa5f72013-08-14 11:59:17 -0400199 return ERR_PTR(-EIO);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200 }
Trond Myklebusta17c2152010-07-31 14:29:08 -0400201 task->tk_rqstp->rq_cred->cr_auth->au_rslack = (size >> 2) + 2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202 p += (size >> 2);
203
204 return p;
205}
206
Trond Myklebust5d8d9a42010-07-31 14:29:07 -0400207int __init rpc_init_authunix(void)
Trond Myklebust9499b432007-06-24 15:57:57 -0400208{
Trond Myklebust5d8d9a42010-07-31 14:29:07 -0400209 return rpcauth_init_credcache(&unix_auth);
210}
211
212void rpc_destroy_authunix(void)
213{
214 rpcauth_destroy_credcache(&unix_auth);
Trond Myklebust9499b432007-06-24 15:57:57 -0400215}
216
Trond Myklebustf1c0a862007-06-23 20:17:58 -0400217const struct rpc_authops authunix_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 .owner = THIS_MODULE,
219 .au_flavor = RPC_AUTH_UNIX,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 .au_name = "UNIX",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 .create = unx_create,
222 .destroy = unx_destroy,
223 .lookup_cred = unx_lookup_cred,
224 .crcreate = unx_create_cred,
225};
226
227static
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228struct rpc_auth unix_auth = {
Chuck Lever45006322016-03-01 13:06:02 -0500229 .au_cslack = UNX_CALLSLACK,
230 .au_rslack = NUL_REPLYSLACK,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 .au_ops = &authunix_ops,
Trond Myklebust81039f12006-06-09 09:34:34 -0400232 .au_flavor = RPC_AUTH_UNIX,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233 .au_count = ATOMIC_INIT(0),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234};
235
236static
Trond Myklebustf1c0a862007-06-23 20:17:58 -0400237const struct rpc_credops unix_credops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238 .cr_name = "AUTH_UNIX",
239 .crdestroy = unx_destroy_cred,
Trond Myklebust5c691042008-03-12 16:21:07 -0400240 .crbind = rpcauth_generic_bind_cred,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241 .crmatch = unx_match,
242 .crmarshal = unx_marshal,
243 .crrefresh = unx_refresh,
244 .crvalidate = unx_validate,
245};