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_GPL(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_GPL(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_GPL(gss_mech_get);
142
143struct gss_api_mech *
144_gss_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
161struct gss_api_mech * gss_mech_get_by_name(const char *name)
162{
163	struct gss_api_mech *gm = NULL;
164
165	gm = _gss_mech_get_by_name(name);
166	if (!gm) {
167		request_module("rpc-auth-gss-%s", name);
168		gm = _gss_mech_get_by_name(name);
169	}
170	return gm;
171}
172EXPORT_SYMBOL_GPL(gss_mech_get_by_name);
173
174struct gss_api_mech *
175gss_mech_get_by_OID(struct xdr_netobj *obj)
176{
177	struct gss_api_mech	*pos, *gm = NULL;
178
179	spin_lock(&registered_mechs_lock);
180	list_for_each_entry(pos, &registered_mechs, gm_list) {
181		if (obj->len == pos->gm_oid.len) {
182			if (0 == memcmp(obj->data, pos->gm_oid.data, obj->len)) {
183				if (try_module_get(pos->gm_owner))
184					gm = pos;
185				break;
186			}
187		}
188	}
189	spin_unlock(&registered_mechs_lock);
190	return gm;
191
192}
193
194EXPORT_SYMBOL_GPL(gss_mech_get_by_OID);
195
196static inline int
197mech_supports_pseudoflavor(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 1;
204	}
205	return 0;
206}
207
208struct gss_api_mech *_gss_mech_get_by_pseudoflavor(u32 pseudoflavor)
209{
210	struct gss_api_mech *gm = NULL, *pos;
211
212	spin_lock(&registered_mechs_lock);
213	list_for_each_entry(pos, &registered_mechs, gm_list) {
214		if (!mech_supports_pseudoflavor(pos, pseudoflavor)) {
215			module_put(pos->gm_owner);
216			continue;
217		}
218		if (try_module_get(pos->gm_owner))
219			gm = pos;
220		break;
221	}
222	spin_unlock(&registered_mechs_lock);
223	return gm;
224}
225
226struct gss_api_mech *
227gss_mech_get_by_pseudoflavor(u32 pseudoflavor)
228{
229	struct gss_api_mech *gm;
230
231	gm = _gss_mech_get_by_pseudoflavor(pseudoflavor);
232
233	if (!gm) {
234		request_module("rpc-auth-gss-%u", pseudoflavor);
235		gm = _gss_mech_get_by_pseudoflavor(pseudoflavor);
236	}
237	return gm;
238}
239
240EXPORT_SYMBOL_GPL(gss_mech_get_by_pseudoflavor);
241
242int gss_mech_list_pseudoflavors(rpc_authflavor_t *array_ptr)
243{
244	struct gss_api_mech *pos = NULL;
245	int j, i = 0;
246
247	spin_lock(&registered_mechs_lock);
248	list_for_each_entry(pos, &registered_mechs, gm_list) {
249		for (j=0; j < pos->gm_pf_num; j++) {
250			array_ptr[i++] = pos->gm_pfs[j].pseudoflavor;
251		}
252	}
253	spin_unlock(&registered_mechs_lock);
254	return i;
255}
256
257EXPORT_SYMBOL_GPL(gss_mech_list_pseudoflavors);
258
259u32
260gss_svc_to_pseudoflavor(struct gss_api_mech *gm, u32 service)
261{
262	int i;
263
264	for (i = 0; i < gm->gm_pf_num; i++) {
265		if (gm->gm_pfs[i].service == service) {
266			return gm->gm_pfs[i].pseudoflavor;
267		}
268	}
269	return RPC_AUTH_MAXFLAVOR; /* illegal value */
270}
271EXPORT_SYMBOL_GPL(gss_svc_to_pseudoflavor);
272
273u32
274gss_pseudoflavor_to_service(struct gss_api_mech *gm, u32 pseudoflavor)
275{
276	int i;
277
278	for (i = 0; i < gm->gm_pf_num; i++) {
279		if (gm->gm_pfs[i].pseudoflavor == pseudoflavor)
280			return gm->gm_pfs[i].service;
281	}
282	return 0;
283}
284
285EXPORT_SYMBOL_GPL(gss_pseudoflavor_to_service);
286
287char *
288gss_service_to_auth_domain_name(struct gss_api_mech *gm, u32 service)
289{
290	int i;
291
292	for (i = 0; i < gm->gm_pf_num; i++) {
293		if (gm->gm_pfs[i].service == service)
294			return gm->gm_pfs[i].auth_domain_name;
295	}
296	return NULL;
297}
298
299EXPORT_SYMBOL_GPL(gss_service_to_auth_domain_name);
300
301void
302gss_mech_put(struct gss_api_mech * gm)
303{
304	if (gm)
305		module_put(gm->gm_owner);
306}
307
308EXPORT_SYMBOL_GPL(gss_mech_put);
309
310/* The mech could probably be determined from the token instead, but it's just
311 * as easy for now to pass it in. */
312int
313gss_import_sec_context(const void *input_token, size_t bufsize,
314		       struct gss_api_mech	*mech,
315		       struct gss_ctx		**ctx_id,
316		       gfp_t gfp_mask)
317{
318	if (!(*ctx_id = kzalloc(sizeof(**ctx_id), gfp_mask)))
319		return -ENOMEM;
320	(*ctx_id)->mech_type = gss_mech_get(mech);
321
322	return mech->gm_ops
323		->gss_import_sec_context(input_token, bufsize, *ctx_id, gfp_mask);
324}
325
326/* gss_get_mic: compute a mic over message and return mic_token. */
327
328u32
329gss_get_mic(struct gss_ctx	*context_handle,
330	    struct xdr_buf	*message,
331	    struct xdr_netobj	*mic_token)
332{
333	 return context_handle->mech_type->gm_ops
334		->gss_get_mic(context_handle,
335			      message,
336			      mic_token);
337}
338
339/* gss_verify_mic: check whether the provided mic_token verifies message. */
340
341u32
342gss_verify_mic(struct gss_ctx		*context_handle,
343	       struct xdr_buf		*message,
344	       struct xdr_netobj	*mic_token)
345{
346	return context_handle->mech_type->gm_ops
347		->gss_verify_mic(context_handle,
348				 message,
349				 mic_token);
350}
351
352/*
353 * This function is called from both the client and server code.
354 * Each makes guarantees about how much "slack" space is available
355 * for the underlying function in "buf"'s head and tail while
356 * performing the wrap.
357 *
358 * The client and server code allocate RPC_MAX_AUTH_SIZE extra
359 * space in both the head and tail which is available for use by
360 * the wrap function.
361 *
362 * Underlying functions should verify they do not use more than
363 * RPC_MAX_AUTH_SIZE of extra space in either the head or tail
364 * when performing the wrap.
365 */
366u32
367gss_wrap(struct gss_ctx	*ctx_id,
368	 int		offset,
369	 struct xdr_buf	*buf,
370	 struct page	**inpages)
371{
372	return ctx_id->mech_type->gm_ops
373		->gss_wrap(ctx_id, offset, buf, inpages);
374}
375
376u32
377gss_unwrap(struct gss_ctx	*ctx_id,
378	   int			offset,
379	   struct xdr_buf	*buf)
380{
381	return ctx_id->mech_type->gm_ops
382		->gss_unwrap(ctx_id, offset, buf);
383}
384
385
386/* gss_delete_sec_context: free all resources associated with context_handle.
387 * Note this differs from the RFC 2744-specified prototype in that we don't
388 * bother returning an output token, since it would never be used anyway. */
389
390u32
391gss_delete_sec_context(struct gss_ctx	**context_handle)
392{
393	dprintk("RPC:       gss_delete_sec_context deleting %p\n",
394			*context_handle);
395
396	if (!*context_handle)
397		return GSS_S_NO_CONTEXT;
398	if ((*context_handle)->internal_ctx_id)
399		(*context_handle)->mech_type->gm_ops
400			->gss_delete_sec_context((*context_handle)
401							->internal_ctx_id);
402	gss_mech_put((*context_handle)->mech_type);
403	kfree(*context_handle);
404	*context_handle=NULL;
405	return GSS_S_COMPLETE;
406}