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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
Linus Torvalds1da177e2005-04-16 15:20:36 -070026#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;
Trond Myklebustf1c0a862007-06-23 20:17:58 -040033static const struct rpc_credops unix_credops;
Linus Torvalds1da177e2005-04-16 15:20:36 -070034
35static struct rpc_auth *
Trond Myklebustc2190662013-08-26 19:23:04 -040036unx_create(struct rpc_auth_create_args *args, struct rpc_clnt *clnt)
Linus Torvalds1da177e2005-04-16 15:20:36 -070037{
Chuck Lever46121cf2007-01-31 12:14:08 -050038 dprintk("RPC: creating UNIX authenticator for client %p\n",
39 clnt);
Trond Myklebustf5c21872007-06-25 17:11:20 -040040 atomic_inc(&unix_auth.au_count);
Linus Torvalds1da177e2005-04-16 15:20:36 -070041 return &unix_auth;
42}
43
44static void
45unx_destroy(struct rpc_auth *auth)
46{
Chuck Lever46121cf2007-01-31 12:14:08 -050047 dprintk("RPC: destroying UNIX authenticator %p\n", auth);
Trond Myklebust3ab9bb72007-06-09 15:41:42 -040048 rpcauth_clear_credcache(auth->au_credcache);
Linus Torvalds1da177e2005-04-16 15:20:36 -070049}
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;
Trond Myklebustaf093832008-03-12 12:12:16 -040064 unsigned int groups = 0;
65 unsigned int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -070066
Chuck Lever46121cf2007-01-31 12:14:08 -050067 dprintk("RPC: allocating UNIX cred for uid %d gid %d\n",
Eric W. Biedermancdba3212013-02-01 17:10:52 -080068 from_kuid(&init_user_ns, acred->uid),
69 from_kgid(&init_user_ns, acred->gid));
Linus Torvalds1da177e2005-04-16 15:20:36 -070070
Trond Myklebust0f38b872008-06-10 18:31:01 -040071 if (!(cred = kmalloc(sizeof(*cred), GFP_NOFS)))
Linus Torvalds1da177e2005-04-16 15:20:36 -070072 return ERR_PTR(-ENOMEM);
73
Trond Myklebust5fe47552007-06-23 19:55:31 -040074 rpcauth_init_cred(&cred->uc_base, acred, auth, &unix_credops);
Trond Myklebustfc432dd2007-06-25 10:15:15 -040075 cred->uc_base.cr_flags = 1UL << RPCAUTH_CRED_UPTODATE;
Linus Torvalds1da177e2005-04-16 15:20:36 -070076
Trond Myklebustaf093832008-03-12 12:12:16 -040077 if (acred->group_info != NULL)
78 groups = acred->group_info->ngroups;
79 if (groups > NFS_NGROUPS)
80 groups = NFS_NGROUPS;
81
82 cred->uc_gid = acred->gid;
Eric W. Biederman9132adb2013-02-01 16:46:42 -080083 for (i = 0; i < groups; i++)
84 cred->uc_gids[i] = GROUP_AT(acred->group_info, i);
Trond Myklebustaf093832008-03-12 12:12:16 -040085 if (i < NFS_NGROUPS)
Eric W. Biedermanbf37f792013-02-01 15:55:38 -080086 cred->uc_gids[i] = INVALID_GID;
Linus Torvalds1da177e2005-04-16 15:20:36 -070087
Trond Myklebust696e38d2007-06-25 09:48:25 -040088 return &cred->uc_base;
Linus Torvalds1da177e2005-04-16 15:20:36 -070089}
90
91static void
Trond Myklebust31be5bf2007-06-24 15:55:26 -040092unx_free_cred(struct unx_cred *unx_cred)
Linus Torvalds1da177e2005-04-16 15:20:36 -070093{
Trond Myklebust31be5bf2007-06-24 15:55:26 -040094 dprintk("RPC: unx_free_cred %p\n", unx_cred);
95 kfree(unx_cred);
96}
Trond Myklebust696e38d2007-06-25 09:48:25 -040097
Trond Myklebust31be5bf2007-06-24 15:55:26 -040098static void
99unx_free_cred_callback(struct rcu_head *head)
100{
101 struct unx_cred *unx_cred = container_of(head, struct unx_cred, uc_base.cr_rcu);
102 unx_free_cred(unx_cred);
103}
104
105static void
106unx_destroy_cred(struct rpc_cred *cred)
107{
108 call_rcu(&cred->cr_rcu, unx_free_cred_callback);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109}
110
111/*
112 * Match credentials against current process creds.
113 * The root_override argument takes care of cases where the caller may
114 * request root creds (e.g. for NFS swapping).
115 */
116static int
Trond Myklebust8a317762006-02-01 12:18:36 -0500117unx_match(struct auth_cred *acred, struct rpc_cred *rcred, int flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118{
Trond Myklebust696e38d2007-06-25 09:48:25 -0400119 struct unx_cred *cred = container_of(rcred, struct unx_cred, uc_base);
Trond Myklebustaf093832008-03-12 12:12:16 -0400120 unsigned int groups = 0;
121 unsigned int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123
Eric W. Biederman0b4d51b2013-02-01 16:39:32 -0800124 if (!uid_eq(cred->uc_uid, acred->uid) || !gid_eq(cred->uc_gid, acred->gid))
Trond Myklebustaf093832008-03-12 12:12:16 -0400125 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126
Trond Myklebustaf093832008-03-12 12:12:16 -0400127 if (acred->group_info != NULL)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 groups = acred->group_info->ngroups;
Trond Myklebustaf093832008-03-12 12:12:16 -0400129 if (groups > NFS_NGROUPS)
130 groups = NFS_NGROUPS;
Eric W. Biederman9132adb2013-02-01 16:46:42 -0800131 for (i = 0; i < groups ; i++)
132 if (!gid_eq(cred->uc_gids[i], GROUP_AT(acred->group_info, i)))
Trond Myklebustaf093832008-03-12 12:12:16 -0400133 return 0;
Eric W. Biedermane572fc72013-02-01 17:18:04 -0800134 if (groups < NFS_NGROUPS && gid_valid(cred->uc_gids[groups]))
NeilBrowndc6f55e2011-10-25 10:25:49 +1100135 return 0;
Trond Myklebustaf093832008-03-12 12:12:16 -0400136 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137}
138
139/*
140 * Marshal credentials.
141 * Maybe we should keep a cached credential for performance reasons.
142 */
Alexey Dobriyand8ed0292006-09-26 22:29:38 -0700143static __be32 *
144unx_marshal(struct rpc_task *task, __be32 *p)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145{
146 struct rpc_clnt *clnt = task->tk_client;
Trond Myklebusta17c2152010-07-31 14:29:08 -0400147 struct unx_cred *cred = container_of(task->tk_rqstp->rq_cred, struct unx_cred, uc_base);
Alexey Dobriyand8ed0292006-09-26 22:29:38 -0700148 __be32 *base, *hold;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149 int i;
150
151 *p++ = htonl(RPC_AUTH_UNIX);
152 base = p++;
153 *p++ = htonl(jiffies/HZ);
154
155 /*
156 * Copy the UTS nodename captured when the client was created.
157 */
158 p = xdr_encode_array(p, clnt->cl_nodename, clnt->cl_nodelen);
159
Eric W. Biedermana570abb2013-02-02 02:45:08 -0800160 *p++ = htonl((u32) from_kuid(&init_user_ns, cred->uc_uid));
161 *p++ = htonl((u32) from_kgid(&init_user_ns, cred->uc_gid));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162 hold = p++;
Eric W. Biedermane572fc72013-02-01 17:18:04 -0800163 for (i = 0; i < 16 && gid_valid(cred->uc_gids[i]); i++)
Eric W. Biedermana570abb2013-02-02 02:45:08 -0800164 *p++ = htonl((u32) from_kgid(&init_user_ns, cred->uc_gids[i]));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165 *hold = htonl(p - hold - 1); /* gid array length */
166 *base = htonl((p - base - 1) << 2); /* cred length */
167
168 *p++ = htonl(RPC_AUTH_NULL);
169 *p++ = htonl(0);
170
171 return p;
172}
173
174/*
175 * Refresh credentials. This is a no-op for AUTH_UNIX
176 */
177static int
178unx_refresh(struct rpc_task *task)
179{
Trond Myklebusta17c2152010-07-31 14:29:08 -0400180 set_bit(RPCAUTH_CRED_UPTODATE, &task->tk_rqstp->rq_cred->cr_flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181 return 0;
182}
183
Alexey Dobriyand8ed0292006-09-26 22:29:38 -0700184static __be32 *
185unx_validate(struct rpc_task *task, __be32 *p)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186{
187 rpc_authflavor_t flavor;
188 u32 size;
189
190 flavor = ntohl(*p++);
191 if (flavor != RPC_AUTH_NULL &&
192 flavor != RPC_AUTH_UNIX &&
193 flavor != RPC_AUTH_SHORT) {
194 printk("RPC: bad verf flavor: %u\n", flavor);
Andy Adamson35fa5f72013-08-14 11:59:17 -0400195 return ERR_PTR(-EIO);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196 }
197
198 size = ntohl(*p++);
199 if (size > RPC_MAX_AUTH_SIZE) {
200 printk("RPC: giant verf size: %u\n", size);
Andy Adamson35fa5f72013-08-14 11:59:17 -0400201 return ERR_PTR(-EIO);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202 }
Trond Myklebusta17c2152010-07-31 14:29:08 -0400203 task->tk_rqstp->rq_cred->cr_auth->au_rslack = (size >> 2) + 2;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204 p += (size >> 2);
205
206 return p;
207}
208
Trond Myklebust5d8d9a42010-07-31 14:29:07 -0400209int __init rpc_init_authunix(void)
Trond Myklebust9499b432007-06-24 15:57:57 -0400210{
Trond Myklebust5d8d9a42010-07-31 14:29:07 -0400211 return rpcauth_init_credcache(&unix_auth);
212}
213
214void rpc_destroy_authunix(void)
215{
216 rpcauth_destroy_credcache(&unix_auth);
Trond Myklebust9499b432007-06-24 15:57:57 -0400217}
218
Trond Myklebustf1c0a862007-06-23 20:17:58 -0400219const struct rpc_authops authunix_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 .owner = THIS_MODULE,
221 .au_flavor = RPC_AUTH_UNIX,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700222 .au_name = "UNIX",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223 .create = unx_create,
224 .destroy = unx_destroy,
225 .lookup_cred = unx_lookup_cred,
226 .crcreate = unx_create_cred,
227};
228
229static
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230struct rpc_auth unix_auth = {
231 .au_cslack = UNX_WRITESLACK,
232 .au_rslack = 2, /* assume AUTH_NULL verf */
233 .au_ops = &authunix_ops,
Trond Myklebust81039f12006-06-09 09:34:34 -0400234 .au_flavor = RPC_AUTH_UNIX,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235 .au_count = ATOMIC_INIT(0),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236};
237
238static
Trond Myklebustf1c0a862007-06-23 20:17:58 -0400239const struct rpc_credops unix_credops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240 .cr_name = "AUTH_UNIX",
241 .crdestroy = unx_destroy_cred,
Trond Myklebust5c691042008-03-12 16:21:07 -0400242 .crbind = rpcauth_generic_bind_cred,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243 .crmatch = unx_match,
244 .crmarshal = unx_marshal,
245 .crrefresh = unx_refresh,
246 .crvalidate = unx_validate,
247};