1/*
2 *  linux/net/sunrpc/gss_mech_switch.c
3 *
4 *  Copyright (c) 2001 The Regents of the University of Michigan.
5 *  All rights reserved.
6 *
7 *  J. Bruce Fields   <bfields@umich.edu>
8 *
9 *  Redistribution and use in source and binary forms, with or without
10 *  modification, are permitted provided that the following conditions
11 *  are met:
12 *
13 *  1. Redistributions of source code must retain the above copyright
14 *     notice, this list of conditions and the following disclaimer.
15 *  2. Redistributions in binary form must reproduce the above copyright
16 *     notice, this list of conditions and the following disclaimer in the
17 *     documentation and/or other materials provided with the distribution.
18 *  3. Neither the name of the University nor the names of its
19 *     contributors may be used to endorse or promote products derived
20 *     from this software without specific prior written permission.
21 *
22 *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
23 *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
24 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
25 *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
27 *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
28 *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
29 *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
30 *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
31 *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
32 *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33 *
34 */
35
36#include <linux/types.h>
37#include <linux/slab.h>
38#include <linux/module.h>
39#include <linux/sunrpc/msg_prot.h>
40#include <linux/sunrpc/gss_asn1.h>
41#include <linux/sunrpc/auth_gss.h>
42#include <linux/sunrpc/svcauth_gss.h>
43#include <linux/sunrpc/gss_err.h>
44#include <linux/sunrpc/sched.h>
45#include <linux/sunrpc/gss_api.h>
46#include <linux/sunrpc/clnt.h>
47
48#ifdef RPC_DEBUG
49# define RPCDBG_FACILITY        RPCDBG_AUTH
50#endif
51
52static LIST_HEAD(registered_mechs);
53static DEFINE_SPINLOCK(registered_mechs_lock);
54
55static void
56gss_mech_free(struct gss_api_mech *gm)
57{
58	struct pf_desc *pf;
59	int i;
60
61	for (i = 0; i < gm->gm_pf_num; i++) {
62		pf = &gm->gm_pfs[i];
63		kfree(pf->auth_domain_name);
64		pf->auth_domain_name = NULL;
65	}
66}
67
68static inline char *
69make_auth_domain_name(char *name)
70{
71	static char	*prefix = "gss/";
72	char		*new;
73
74	new = kmalloc(strlen(name) + strlen(prefix) + 1, GFP_KERNEL);
75	if (new) {
76		strcpy(new, prefix);
77		strcat(new, name);
78	}
79	return new;
80}
81
82static int
83gss_mech_svc_setup(struct gss_api_mech *gm)
84{
85	struct pf_desc *pf;
86	int i, status;
87
88	for (i = 0; i < gm->gm_pf_num; i++) {
89		pf = &gm->gm_pfs[i];
90		pf->auth_domain_name = make_auth_domain_name(pf->name);
91		status = -ENOMEM;
92		if (pf->auth_domain_name == NULL)
93			goto out;
94		status = svcauth_gss_register_pseudoflavor(pf->pseudoflavor,
95							pf->auth_domain_name);
96		if (status)
97			goto out;
98	}
99	return 0;
100out:
101	gss_mech_free(gm);
102	return status;
103}
104
105int
106gss_mech_register(struct gss_api_mech *gm)
107{
108	int status;
109
110	status = gss_mech_svc_setup(gm);
111	if (status)
112		return status;
113	spin_lock(&registered_mechs_lock);
114	list_add(&gm->gm_list, &registered_mechs);
115	spin_unlock(&registered_mechs_lock);
116	dprintk("RPC:       registered gss mechanism %s\n", gm->gm_name);
117	return 0;
118}
119
120EXPORT_SYMBOL(gss_mech_register);
121
122void
123gss_mech_unregister(struct gss_api_mech *gm)
124{
125	spin_lock(&registered_mechs_lock);
126	list_del(&gm->gm_list);
127	spin_unlock(&registered_mechs_lock);
128	dprintk("RPC:       unregistered gss mechanism %s\n", gm->gm_name);
129	gss_mech_free(gm);
130}
131
132EXPORT_SYMBOL(gss_mech_unregister);
133
134struct gss_api_mech *
135gss_mech_get(struct gss_api_mech *gm)
136{
137	__module_get(gm->gm_owner);
138	return gm;
139}
140
141EXPORT_SYMBOL(gss_mech_get);
142
143struct gss_api_mech *
144gss_mech_get_by_name(const char *name)
145{
146	struct gss_api_mech	*pos, *gm = NULL;
147
148	spin_lock(&registered_mechs_lock);
149	list_for_each_entry(pos, &registered_mechs, gm_list) {
150		if (0 == strcmp(name, pos->gm_name)) {
151			if (try_module_get(pos->gm_owner))
152				gm = pos;
153			break;
154		}
155	}
156	spin_unlock(&registered_mechs_lock);
157	return gm;
158
159}
160
161EXPORT_SYMBOL(gss_mech_get_by_name);
162
163static inline int
164mech_supports_pseudoflavor(struct gss_api_mech *gm, u32 pseudoflavor)
165{
166	int i;
167
168	for (i = 0; i < gm->gm_pf_num; i++) {
169		if (gm->gm_pfs[i].pseudoflavor == pseudoflavor)
170			return 1;
171	}
172	return 0;
173}
174
175struct gss_api_mech *
176gss_mech_get_by_pseudoflavor(u32 pseudoflavor)
177{
178	struct gss_api_mech *pos, *gm = NULL;
179
180	spin_lock(&registered_mechs_lock);
181	list_for_each_entry(pos, &registered_mechs, gm_list) {
182		if (!mech_supports_pseudoflavor(pos, pseudoflavor)) {
183			module_put(pos->gm_owner);
184			continue;
185		}
186		if (try_module_get(pos->gm_owner))
187			gm = pos;
188		break;
189	}
190	spin_unlock(&registered_mechs_lock);
191	return gm;
192}
193
194EXPORT_SYMBOL(gss_mech_get_by_pseudoflavor);
195
196u32
197gss_pseudoflavor_to_service(struct gss_api_mech *gm, u32 pseudoflavor)
198{
199	int i;
200
201	for (i = 0; i < gm->gm_pf_num; i++) {
202		if (gm->gm_pfs[i].pseudoflavor == pseudoflavor)
203			return gm->gm_pfs[i].service;
204	}
205	return 0;
206}
207
208EXPORT_SYMBOL(gss_pseudoflavor_to_service);
209
210char *
211gss_service_to_auth_domain_name(struct gss_api_mech *gm, u32 service)
212{
213	int i;
214
215	for (i = 0; i < gm->gm_pf_num; i++) {
216		if (gm->gm_pfs[i].service == service)
217			return gm->gm_pfs[i].auth_domain_name;
218	}
219	return NULL;
220}
221
222EXPORT_SYMBOL(gss_service_to_auth_domain_name);
223
224void
225gss_mech_put(struct gss_api_mech * gm)
226{
227	if (gm)
228		module_put(gm->gm_owner);
229}
230
231EXPORT_SYMBOL(gss_mech_put);
232
233/* The mech could probably be determined from the token instead, but it's just
234 * as easy for now to pass it in. */
235int
236gss_import_sec_context(const void *input_token, size_t bufsize,
237		       struct gss_api_mech	*mech,
238		       struct gss_ctx		**ctx_id)
239{
240	if (!(*ctx_id = kzalloc(sizeof(**ctx_id), GFP_KERNEL)))
241		return GSS_S_FAILURE;
242	(*ctx_id)->mech_type = gss_mech_get(mech);
243
244	return mech->gm_ops
245		->gss_import_sec_context(input_token, bufsize, *ctx_id);
246}
247
248/* gss_get_mic: compute a mic over message and return mic_token. */
249
250u32
251gss_get_mic(struct gss_ctx	*context_handle,
252	    struct xdr_buf	*message,
253	    struct xdr_netobj	*mic_token)
254{
255	 return context_handle->mech_type->gm_ops
256		->gss_get_mic(context_handle,
257			      message,
258			      mic_token);
259}
260
261/* gss_verify_mic: check whether the provided mic_token verifies message. */
262
263u32
264gss_verify_mic(struct gss_ctx		*context_handle,
265	       struct xdr_buf		*message,
266	       struct xdr_netobj	*mic_token)
267{
268	return context_handle->mech_type->gm_ops
269		->gss_verify_mic(context_handle,
270				 message,
271				 mic_token);
272}
273
274u32
275gss_wrap(struct gss_ctx	*ctx_id,
276	 int		offset,
277	 struct xdr_buf	*buf,
278	 struct page	**inpages)
279{
280	return ctx_id->mech_type->gm_ops
281		->gss_wrap(ctx_id, offset, buf, inpages);
282}
283
284u32
285gss_unwrap(struct gss_ctx	*ctx_id,
286	   int			offset,
287	   struct xdr_buf	*buf)
288{
289	return ctx_id->mech_type->gm_ops
290		->gss_unwrap(ctx_id, offset, buf);
291}
292
293
294/* gss_delete_sec_context: free all resources associated with context_handle.
295 * Note this differs from the RFC 2744-specified prototype in that we don't
296 * bother returning an output token, since it would never be used anyway. */
297
298u32
299gss_delete_sec_context(struct gss_ctx	**context_handle)
300{
301	dprintk("RPC:       gss_delete_sec_context deleting %p\n",
302			*context_handle);
303
304	if (!*context_handle)
305		return(GSS_S_NO_CONTEXT);
306	if ((*context_handle)->internal_ctx_id != 0)
307		(*context_handle)->mech_type->gm_ops
308			->gss_delete_sec_context((*context_handle)
309							->internal_ctx_id);
310	gss_mech_put((*context_handle)->mech_type);
311	kfree(*context_handle);
312	*context_handle=NULL;
313	return GSS_S_COMPLETE;
314}
315