SUNRPC: Introduce rpcauth_get_pseudoflavor()
[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 static 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 static struct gss_api_mech *gss_mech_get_by_OID(struct rpcsec_gss_oid *obj)
175 {
176         struct gss_api_mech     *pos, *gm = NULL;
177
178         spin_lock(&registered_mechs_lock);
179         list_for_each_entry(pos, &registered_mechs, gm_list) {
180                 if (obj->len == pos->gm_oid.len) {
181                         if (0 == memcmp(obj->data, pos->gm_oid.data, obj->len)) {
182                                 if (try_module_get(pos->gm_owner))
183                                         gm = pos;
184                                 break;
185                         }
186                 }
187         }
188         spin_unlock(&registered_mechs_lock);
189         return gm;
190 }
191
192 static inline int
193 mech_supports_pseudoflavor(struct gss_api_mech *gm, u32 pseudoflavor)
194 {
195         int i;
196
197         for (i = 0; i < gm->gm_pf_num; i++) {
198                 if (gm->gm_pfs[i].pseudoflavor == pseudoflavor)
199                         return 1;
200         }
201         return 0;
202 }
203
204 static struct gss_api_mech *_gss_mech_get_by_pseudoflavor(u32 pseudoflavor)
205 {
206         struct gss_api_mech *gm = NULL, *pos;
207
208         spin_lock(&registered_mechs_lock);
209         list_for_each_entry(pos, &registered_mechs, gm_list) {
210                 if (!mech_supports_pseudoflavor(pos, pseudoflavor)) {
211                         module_put(pos->gm_owner);
212                         continue;
213                 }
214                 if (try_module_get(pos->gm_owner))
215                         gm = pos;
216                 break;
217         }
218         spin_unlock(&registered_mechs_lock);
219         return gm;
220 }
221
222 struct gss_api_mech *
223 gss_mech_get_by_pseudoflavor(u32 pseudoflavor)
224 {
225         struct gss_api_mech *gm;
226
227         gm = _gss_mech_get_by_pseudoflavor(pseudoflavor);
228
229         if (!gm) {
230                 request_module("rpc-auth-gss-%u", pseudoflavor);
231                 gm = _gss_mech_get_by_pseudoflavor(pseudoflavor);
232         }
233         return gm;
234 }
235
236 EXPORT_SYMBOL_GPL(gss_mech_get_by_pseudoflavor);
237
238 /**
239  * gss_mech_list_pseudoflavors - Discover registered GSS pseudoflavors
240  * @array: array to fill in
241  * @size: size of "array"
242  *
243  * Returns the number of array items filled in, or a negative errno.
244  *
245  * The returned array is not sorted by any policy.  Callers should not
246  * rely on the order of the items in the returned array.
247  */
248 int gss_mech_list_pseudoflavors(rpc_authflavor_t *array_ptr, int size)
249 {
250         struct gss_api_mech *pos = NULL;
251         int j, i = 0;
252
253         spin_lock(&registered_mechs_lock);
254         list_for_each_entry(pos, &registered_mechs, gm_list) {
255                 for (j = 0; j < pos->gm_pf_num; j++) {
256                         if (i >= size) {
257                                 spin_unlock(&registered_mechs_lock);
258                                 return -ENOMEM;
259                         }
260                         array_ptr[i++] = pos->gm_pfs[j].pseudoflavor;
261                 }
262         }
263         spin_unlock(&registered_mechs_lock);
264         return i;
265 }
266
267 u32
268 gss_svc_to_pseudoflavor(struct gss_api_mech *gm, u32 service)
269 {
270         int i;
271
272         for (i = 0; i < gm->gm_pf_num; i++) {
273                 if (gm->gm_pfs[i].service == service) {
274                         return gm->gm_pfs[i].pseudoflavor;
275                 }
276         }
277         return RPC_AUTH_MAXFLAVOR; /* illegal value */
278 }
279 EXPORT_SYMBOL_GPL(gss_svc_to_pseudoflavor);
280
281 /**
282  * gss_mech_info2flavor - look up a pseudoflavor given a GSS tuple
283  * @info: a GSS mech OID, quality of protection, and service value
284  *
285  * Returns a matching pseudoflavor, or RPC_AUTH_MAXFLAVOR if the tuple is
286  * not supported.
287  */
288 rpc_authflavor_t gss_mech_info2flavor(struct rpcsec_gss_info *info)
289 {
290         rpc_authflavor_t pseudoflavor;
291         struct gss_api_mech *gm;
292
293         gm = gss_mech_get_by_OID(&info->oid);
294         if (gm == NULL)
295                 return RPC_AUTH_MAXFLAVOR;
296
297         pseudoflavor = gss_svc_to_pseudoflavor(gm, info->service);
298
299         gss_mech_put(gm);
300         return pseudoflavor;
301 }
302
303 u32
304 gss_pseudoflavor_to_service(struct gss_api_mech *gm, u32 pseudoflavor)
305 {
306         int i;
307
308         for (i = 0; i < gm->gm_pf_num; i++) {
309                 if (gm->gm_pfs[i].pseudoflavor == pseudoflavor)
310                         return gm->gm_pfs[i].service;
311         }
312         return 0;
313 }
314
315 EXPORT_SYMBOL_GPL(gss_pseudoflavor_to_service);
316
317 char *
318 gss_service_to_auth_domain_name(struct gss_api_mech *gm, u32 service)
319 {
320         int i;
321
322         for (i = 0; i < gm->gm_pf_num; i++) {
323                 if (gm->gm_pfs[i].service == service)
324                         return gm->gm_pfs[i].auth_domain_name;
325         }
326         return NULL;
327 }
328
329 EXPORT_SYMBOL_GPL(gss_service_to_auth_domain_name);
330
331 void
332 gss_mech_put(struct gss_api_mech * gm)
333 {
334         if (gm)
335                 module_put(gm->gm_owner);
336 }
337
338 EXPORT_SYMBOL_GPL(gss_mech_put);
339
340 /* The mech could probably be determined from the token instead, but it's just
341  * as easy for now to pass it in. */
342 int
343 gss_import_sec_context(const void *input_token, size_t bufsize,
344                        struct gss_api_mech      *mech,
345                        struct gss_ctx           **ctx_id,
346                        gfp_t gfp_mask)
347 {
348         if (!(*ctx_id = kzalloc(sizeof(**ctx_id), gfp_mask)))
349                 return -ENOMEM;
350         (*ctx_id)->mech_type = gss_mech_get(mech);
351
352         return mech->gm_ops
353                 ->gss_import_sec_context(input_token, bufsize, *ctx_id, gfp_mask);
354 }
355
356 /* gss_get_mic: compute a mic over message and return mic_token. */
357
358 u32
359 gss_get_mic(struct gss_ctx      *context_handle,
360             struct xdr_buf      *message,
361             struct xdr_netobj   *mic_token)
362 {
363          return context_handle->mech_type->gm_ops
364                 ->gss_get_mic(context_handle,
365                               message,
366                               mic_token);
367 }
368
369 /* gss_verify_mic: check whether the provided mic_token verifies message. */
370
371 u32
372 gss_verify_mic(struct gss_ctx           *context_handle,
373                struct xdr_buf           *message,
374                struct xdr_netobj        *mic_token)
375 {
376         return context_handle->mech_type->gm_ops
377                 ->gss_verify_mic(context_handle,
378                                  message,
379                                  mic_token);
380 }
381
382 /*
383  * This function is called from both the client and server code.
384  * Each makes guarantees about how much "slack" space is available
385  * for the underlying function in "buf"'s head and tail while
386  * performing the wrap.
387  *
388  * The client and server code allocate RPC_MAX_AUTH_SIZE extra
389  * space in both the head and tail which is available for use by
390  * the wrap function.
391  *
392  * Underlying functions should verify they do not use more than
393  * RPC_MAX_AUTH_SIZE of extra space in either the head or tail
394  * when performing the wrap.
395  */
396 u32
397 gss_wrap(struct gss_ctx *ctx_id,
398          int            offset,
399          struct xdr_buf *buf,
400          struct page    **inpages)
401 {
402         return ctx_id->mech_type->gm_ops
403                 ->gss_wrap(ctx_id, offset, buf, inpages);
404 }
405
406 u32
407 gss_unwrap(struct gss_ctx       *ctx_id,
408            int                  offset,
409            struct xdr_buf       *buf)
410 {
411         return ctx_id->mech_type->gm_ops
412                 ->gss_unwrap(ctx_id, offset, buf);
413 }
414
415
416 /* gss_delete_sec_context: free all resources associated with context_handle.
417  * Note this differs from the RFC 2744-specified prototype in that we don't
418  * bother returning an output token, since it would never be used anyway. */
419
420 u32
421 gss_delete_sec_context(struct gss_ctx   **context_handle)
422 {
423         dprintk("RPC:       gss_delete_sec_context deleting %p\n",
424                         *context_handle);
425
426         if (!*context_handle)
427                 return GSS_S_NO_CONTEXT;
428         if ((*context_handle)->internal_ctx_id)
429                 (*context_handle)->mech_type->gm_ops
430                         ->gss_delete_sec_context((*context_handle)
431                                                         ->internal_ctx_id);
432         gss_mech_put((*context_handle)->mech_type);
433         kfree(*context_handle);
434         *context_handle=NULL;
435         return GSS_S_COMPLETE;
436 }