rpc: allow autoloading of gss mechanisms
[linux-3.10.git] / net / sunrpc / auth_gss / gss_mech_switch.c
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
52 static LIST_HEAD(registered_mechs);
53 static DEFINE_SPINLOCK(registered_mechs_lock);
54
55 static void
56 gss_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
68 static inline char *
69 make_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
82 static int
83 gss_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;
100 out:
101         gss_mech_free(gm);
102         return status;
103 }
104
105 int
106 gss_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
120 EXPORT_SYMBOL_GPL(gss_mech_register);
121
122 void
123 gss_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
132 EXPORT_SYMBOL_GPL(gss_mech_unregister);
133
134 struct gss_api_mech *
135 gss_mech_get(struct gss_api_mech *gm)
136 {
137         __module_get(gm->gm_owner);
138         return gm;
139 }
140
141 EXPORT_SYMBOL_GPL(gss_mech_get);
142
143 struct 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
161 struct 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 }
172 EXPORT_SYMBOL_GPL(gss_mech_get_by_name);
173
174 struct gss_api_mech *
175 gss_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
194 EXPORT_SYMBOL_GPL(gss_mech_get_by_OID);
195
196 static inline int
197 mech_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
208 struct 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
226 struct gss_api_mech *
227 gss_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
240 EXPORT_SYMBOL_GPL(gss_mech_get_by_pseudoflavor);
241
242 int gss_mech_list_pseudoflavors(rpc_authflavor_t *array_ptr)
243 {
244         struct gss_api_mech *pos = NULL;
245         int i = 0;
246
247         spin_lock(&registered_mechs_lock);
248         list_for_each_entry(pos, &registered_mechs, gm_list) {
249                 array_ptr[i] = pos->gm_pfs->pseudoflavor;
250                 i++;
251         }
252         spin_unlock(&registered_mechs_lock);
253         return i;
254 }
255
256 EXPORT_SYMBOL_GPL(gss_mech_list_pseudoflavors);
257
258 u32
259 gss_svc_to_pseudoflavor(struct gss_api_mech *gm, u32 service)
260 {
261         int i;
262
263         for (i = 0; i < gm->gm_pf_num; i++) {
264                 if (gm->gm_pfs[i].service == service) {
265                         return gm->gm_pfs[i].pseudoflavor;
266                 }
267         }
268         return RPC_AUTH_MAXFLAVOR; /* illegal value */
269 }
270 EXPORT_SYMBOL_GPL(gss_svc_to_pseudoflavor);
271
272 u32
273 gss_pseudoflavor_to_service(struct gss_api_mech *gm, u32 pseudoflavor)
274 {
275         int i;
276
277         for (i = 0; i < gm->gm_pf_num; i++) {
278                 if (gm->gm_pfs[i].pseudoflavor == pseudoflavor)
279                         return gm->gm_pfs[i].service;
280         }
281         return 0;
282 }
283
284 EXPORT_SYMBOL_GPL(gss_pseudoflavor_to_service);
285
286 char *
287 gss_service_to_auth_domain_name(struct gss_api_mech *gm, u32 service)
288 {
289         int i;
290
291         for (i = 0; i < gm->gm_pf_num; i++) {
292                 if (gm->gm_pfs[i].service == service)
293                         return gm->gm_pfs[i].auth_domain_name;
294         }
295         return NULL;
296 }
297
298 EXPORT_SYMBOL_GPL(gss_service_to_auth_domain_name);
299
300 void
301 gss_mech_put(struct gss_api_mech * gm)
302 {
303         if (gm)
304                 module_put(gm->gm_owner);
305 }
306
307 EXPORT_SYMBOL_GPL(gss_mech_put);
308
309 /* The mech could probably be determined from the token instead, but it's just
310  * as easy for now to pass it in. */
311 int
312 gss_import_sec_context(const void *input_token, size_t bufsize,
313                        struct gss_api_mech      *mech,
314                        struct gss_ctx           **ctx_id,
315                        gfp_t gfp_mask)
316 {
317         if (!(*ctx_id = kzalloc(sizeof(**ctx_id), gfp_mask)))
318                 return -ENOMEM;
319         (*ctx_id)->mech_type = gss_mech_get(mech);
320
321         return mech->gm_ops
322                 ->gss_import_sec_context(input_token, bufsize, *ctx_id, gfp_mask);
323 }
324
325 /* gss_get_mic: compute a mic over message and return mic_token. */
326
327 u32
328 gss_get_mic(struct gss_ctx      *context_handle,
329             struct xdr_buf      *message,
330             struct xdr_netobj   *mic_token)
331 {
332          return context_handle->mech_type->gm_ops
333                 ->gss_get_mic(context_handle,
334                               message,
335                               mic_token);
336 }
337
338 /* gss_verify_mic: check whether the provided mic_token verifies message. */
339
340 u32
341 gss_verify_mic(struct gss_ctx           *context_handle,
342                struct xdr_buf           *message,
343                struct xdr_netobj        *mic_token)
344 {
345         return context_handle->mech_type->gm_ops
346                 ->gss_verify_mic(context_handle,
347                                  message,
348                                  mic_token);
349 }
350
351 /*
352  * This function is called from both the client and server code.
353  * Each makes guarantees about how much "slack" space is available
354  * for the underlying function in "buf"'s head and tail while
355  * performing the wrap.
356  *
357  * The client and server code allocate RPC_MAX_AUTH_SIZE extra
358  * space in both the head and tail which is available for use by
359  * the wrap function.
360  *
361  * Underlying functions should verify they do not use more than
362  * RPC_MAX_AUTH_SIZE of extra space in either the head or tail
363  * when performing the wrap.
364  */
365 u32
366 gss_wrap(struct gss_ctx *ctx_id,
367          int            offset,
368          struct xdr_buf *buf,
369          struct page    **inpages)
370 {
371         return ctx_id->mech_type->gm_ops
372                 ->gss_wrap(ctx_id, offset, buf, inpages);
373 }
374
375 u32
376 gss_unwrap(struct gss_ctx       *ctx_id,
377            int                  offset,
378            struct xdr_buf       *buf)
379 {
380         return ctx_id->mech_type->gm_ops
381                 ->gss_unwrap(ctx_id, offset, buf);
382 }
383
384
385 /* gss_delete_sec_context: free all resources associated with context_handle.
386  * Note this differs from the RFC 2744-specified prototype in that we don't
387  * bother returning an output token, since it would never be used anyway. */
388
389 u32
390 gss_delete_sec_context(struct gss_ctx   **context_handle)
391 {
392         dprintk("RPC:       gss_delete_sec_context deleting %p\n",
393                         *context_handle);
394
395         if (!*context_handle)
396                 return GSS_S_NO_CONTEXT;
397         if ((*context_handle)->internal_ctx_id)
398                 (*context_handle)->mech_type->gm_ops
399                         ->gss_delete_sec_context((*context_handle)
400                                                         ->internal_ctx_id);
401         gss_mech_put((*context_handle)->mech_type);
402         kfree(*context_handle);
403         *context_handle=NULL;
404         return GSS_S_COMPLETE;
405 }