summaryrefslogtreecommitdiff
path: root/net/sunrpc/auth_gss/gss_rpc_upcall.c
blob: abbb7dcd16897125863098cb48f6a6411488225c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
/*
 *  linux/net/sunrpc/gss_rpc_upcall.c
 *
 *  Copyright (C) 2012 Simo Sorce <simo@redhat.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/types.h>
#include <linux/un.h>

#include <linux/sunrpc/svcauth.h>
#include "gss_rpc_upcall.h"

#define GSSPROXY_SOCK_PATHNAME	"/var/run/gssproxy.sock"

#define GSSPROXY_PROGRAM	(400112u)
#define GSSPROXY_VERS_1		(1u)

/*
 * Encoding/Decoding functions
 */

enum {
	GSSX_NULL = 0,	/* Unused */
        GSSX_INDICATE_MECHS = 1,
        GSSX_GET_CALL_CONTEXT = 2,
        GSSX_IMPORT_AND_CANON_NAME = 3,
        GSSX_EXPORT_CRED = 4,
        GSSX_IMPORT_CRED = 5,
        GSSX_ACQUIRE_CRED = 6,
        GSSX_STORE_CRED = 7,
        GSSX_INIT_SEC_CONTEXT = 8,
        GSSX_ACCEPT_SEC_CONTEXT = 9,
        GSSX_RELEASE_HANDLE = 10,
        GSSX_GET_MIC = 11,
        GSSX_VERIFY = 12,
        GSSX_WRAP = 13,
        GSSX_UNWRAP = 14,
        GSSX_WRAP_SIZE_LIMIT = 15,
};

#define PROC(proc, name)				\
[GSSX_##proc] = {					\
	.p_proc   = GSSX_##proc,			\
	.p_encode = (kxdreproc_t)gssx_enc_##name,	\
	.p_decode = (kxdrdproc_t)gssx_dec_##name,	\
	.p_arglen = GSSX_ARG_##name##_sz,		\
	.p_replen = GSSX_RES_##name##_sz, 		\
	.p_statidx = GSSX_##proc,			\
	.p_name   = #proc,				\
}

static struct rpc_procinfo gssp_procedures[] = {
	PROC(INDICATE_MECHS, indicate_mechs),
        PROC(GET_CALL_CONTEXT, get_call_context),
        PROC(IMPORT_AND_CANON_NAME, import_and_canon_name),
        PROC(EXPORT_CRED, export_cred),
        PROC(IMPORT_CRED, import_cred),
        PROC(ACQUIRE_CRED, acquire_cred),
        PROC(STORE_CRED, store_cred),
        PROC(INIT_SEC_CONTEXT, init_sec_context),
        PROC(ACCEPT_SEC_CONTEXT, accept_sec_context),
        PROC(RELEASE_HANDLE, release_handle),
        PROC(GET_MIC, get_mic),
        PROC(VERIFY, verify),
        PROC(WRAP, wrap),
        PROC(UNWRAP, unwrap),
        PROC(WRAP_SIZE_LIMIT, wrap_size_limit),
};



/*
 * Common transport functions
 */

static const struct rpc_program gssp_program;

static int gssp_rpc_create(struct net *net, struct rpc_clnt **_clnt)
{
	static const struct sockaddr_un gssp_localaddr = {
		.sun_family		= AF_LOCAL,
		.sun_path		= GSSPROXY_SOCK_PATHNAME,
	};
	struct rpc_create_args args = {
		.net		= net,
		.protocol	= XPRT_TRANSPORT_LOCAL,
		.address	= (struct sockaddr *)&gssp_localaddr,
		.addrsize	= sizeof(gssp_localaddr),
		.servername	= "localhost",
		.program	= &gssp_program,
		.version	= GSSPROXY_VERS_1,
		.authflavor	= RPC_AUTH_NULL,
		/*
		 * Note we want connection to be done in the caller's
		 * filesystem namespace.  We therefore turn off the idle
		 * timeout, which would result in reconnections being
		 * done without the correct namespace:
		 */
		.flags		= RPC_CLNT_CREATE_NOPING |
				  RPC_CLNT_CREATE_NO_IDLE_TIMEOUT
	};
	struct rpc_clnt *clnt;
	int result = 0;

	clnt = rpc_create(&args);
	if (IS_ERR(clnt)) {
		dprintk("RPC:       failed to create AF_LOCAL gssproxy "
				"client (errno %ld).\n", PTR_ERR(clnt));
		result = PTR_ERR(clnt);
		*_clnt = NULL;
		goto out;
	}

	dprintk("RPC:       created new gssp local client (gssp_local_clnt: "
			"%p)\n", clnt);
	*_clnt = clnt;

out:
	return result;
}

void init_gssp_clnt(struct sunrpc_net *sn)
{
	mutex_init(&sn->gssp_lock);
	sn->gssp_clnt = NULL;
}

int set_gssp_clnt(struct net *net)
{
	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
	struct rpc_clnt *clnt;
	int ret;

	mutex_lock(&sn->gssp_lock);
	ret = gssp_rpc_create(net, &clnt);
	if (!ret) {
		if (sn->gssp_clnt)
			rpc_shutdown_client(sn->gssp_clnt);
		sn->gssp_clnt = clnt;
	}
	mutex_unlock(&sn->gssp_lock);
	return ret;
}

void clear_gssp_clnt(struct sunrpc_net *sn)
{
	mutex_lock(&sn->gssp_lock);
	if (sn->gssp_clnt) {
		rpc_shutdown_client(sn->gssp_clnt);
		sn->gssp_clnt = NULL;
	}
	mutex_unlock(&sn->gssp_lock);
}

static struct rpc_clnt *get_gssp_clnt(struct sunrpc_net *sn)
{
	struct rpc_clnt *clnt;

	mutex_lock(&sn->gssp_lock);
	clnt = sn->gssp_clnt;
	if (clnt)
		atomic_inc(&clnt->cl_count);
	mutex_unlock(&sn->gssp_lock);
	return clnt;
}

static int gssp_call(struct net *net, struct rpc_message *msg)
{
	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
	struct rpc_clnt *clnt;
	int status;

	clnt = get_gssp_clnt(sn);
	if (!clnt)
		return -EIO;
	status = rpc_call_sync(clnt, msg, 0);
	if (status < 0) {
		dprintk("gssp: rpc_call returned error %d\n", -status);
		switch (status) {
		case -EPROTONOSUPPORT:
			status = -EINVAL;
			break;
		case -ECONNREFUSED:
		case -ETIMEDOUT:
		case -ENOTCONN:
			status = -EAGAIN;
			break;
		case -ERESTARTSYS:
			if (signalled ())
				status = -EINTR;
			break;
		default:
			break;
		}
	}
	rpc_release_client(clnt);
	return status;
}

static void gssp_free_receive_pages(struct gssx_arg_accept_sec_context *arg)
{
	int i;

	for (i = 0; i < arg->npages && arg->pages[i]; i++)
		__free_page(arg->pages[i]);
}

static int gssp_alloc_receive_pages(struct gssx_arg_accept_sec_context *arg)
{
	arg->npages = DIV_ROUND_UP(NGROUPS_MAX * 4, PAGE_SIZE);
	arg->pages = kzalloc(arg->npages * sizeof(struct page *), GFP_KERNEL);
	/*
	 * XXX: actual pages are allocated by xdr layer in
	 * xdr_partial_copy_from_skb.
	 */
	if (!arg->pages)
		return -ENOMEM;
	return 0;
}

/*
 * Public functions
 */

/* numbers somewhat arbitrary but large enough for current needs */
#define GSSX_MAX_OUT_HANDLE	128
#define GSSX_MAX_SRC_PRINC	256
#define GSSX_KMEMBUF (GSSX_max_output_handle_sz + \
			GSSX_max_oid_sz + \
			GSSX_max_princ_sz + \
			sizeof(struct svc_cred))

int gssp_accept_sec_context_upcall(struct net *net,
				struct gssp_upcall_data *data)
{
	struct gssx_ctx ctxh = {
		.state = data->in_handle
	};
	struct gssx_arg_accept_sec_context arg = {
		.input_token = data->in_token,
	};
	struct gssx_ctx rctxh = {
		/*
		 * pass in the max length we expect for each of these
		 * buffers but let the xdr code kmalloc them:
		 */
		.exported_context_token.len = GSSX_max_output_handle_sz,
		.mech.len = GSS_OID_MAX_LEN,
		.src_name.display_name.len = GSSX_max_princ_sz
	};
	struct gssx_res_accept_sec_context res = {
		.context_handle = &rctxh,
		.output_token = &data->out_token
	};
	struct rpc_message msg = {
		.rpc_proc = &gssp_procedures[GSSX_ACCEPT_SEC_CONTEXT],
		.rpc_argp = &arg,
		.rpc_resp = &res,
		.rpc_cred = NULL, /* FIXME ? */
	};
	struct xdr_netobj client_name = { 0 , NULL };
	int ret;

	if (data->in_handle.len != 0)
		arg.context_handle = &ctxh;
	res.output_token->len = GSSX_max_output_token_sz;

	ret = gssp_alloc_receive_pages(&arg);
	if (ret)
		return ret;

	/* use nfs/ for targ_name ? */

	ret = gssp_call(net, &msg);

	gssp_free_receive_pages(&arg);

	/* we need to fetch all data even in case of error so
	 * that we can free special strctures is they have been allocated */
	data->major_status = res.status.major_status;
	data->minor_status = res.status.minor_status;
	if (res.context_handle) {
		data->out_handle = rctxh.exported_context_token;
		data->mech_oid.len = rctxh.mech.len;
		if (rctxh.mech.data)
			memcpy(data->mech_oid.data, rctxh.mech.data,
						data->mech_oid.len);
		client_name = rctxh.src_name.display_name;
	}

	if (res.options.count == 1) {
		gssx_buffer *value = &res.options.data[0].value;
		/* Currently we only decode CREDS_VALUE, if we add
		 * anything else we'll have to loop and match on the
		 * option name */
		if (value->len == 1) {
			/* steal group info from struct svc_cred */
			data->creds = *(struct svc_cred *)value->data;
			data->found_creds = 1;
		}
		/* whether we use it or not, free data */
		kfree(value->data);
	}

	if (res.options.count != 0) {
		kfree(res.options.data);
	}

	/* convert to GSS_NT_HOSTBASED_SERVICE form and set into creds */
	if (data->found_creds && client_name.data != NULL) {
		char *c;

		data->creds.cr_principal = kstrndup(client_name.data,
						client_name.len, GFP_KERNEL);
		if (data->creds.cr_principal) {
			/* terminate and remove realm part */
			c = strchr(data->creds.cr_principal, '@');
			if (c) {
				*c = '\0';

				/* change service-hostname delimiter */
				c = strchr(data->creds.cr_principal, '/');
				if (c) *c = '@';
			}
			if (!c) {
				/* not a service principal */
				kfree(data->creds.cr_principal);
				data->creds.cr_principal = NULL;
			}
		}
	}
	kfree(client_name.data);

	return ret;
}

void gssp_free_upcall_data(struct gssp_upcall_data *data)
{
	kfree(data->in_handle.data);
	kfree(data->out_handle.data);
	kfree(data->out_token.data);
	free_svc_cred(&data->creds);
}

/*
 * Initialization stuff
 */

static const struct rpc_version gssp_version1 = {
	.number		= GSSPROXY_VERS_1,
	.nrprocs	= ARRAY_SIZE(gssp_procedures),
	.procs		= gssp_procedures,
};

static const struct rpc_version *gssp_version[] = {
	NULL,
	&gssp_version1,
};

static struct rpc_stat gssp_stats;

static const struct rpc_program gssp_program = {
	.name		= "gssproxy",
	.number		= GSSPROXY_PROGRAM,
	.nrvers		= ARRAY_SIZE(gssp_version),
	.version	= gssp_version,
	.stats		= &gssp_stats,
};