Merge branch 'for-3.10' of git://linux-nfs.org/~bfields/linux
[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/oid_registry.h>
40 #include <linux/sunrpc/msg_prot.h>
41 #include <linux/sunrpc/gss_asn1.h>
42 #include <linux/sunrpc/auth_gss.h>
43 #include <linux/sunrpc/svcauth_gss.h>
44 #include <linux/sunrpc/gss_err.h>
45 #include <linux/sunrpc/sched.h>
46 #include <linux/sunrpc/gss_api.h>
47 #include <linux/sunrpc/clnt.h>
48
49 #ifdef RPC_DEBUG
50 # define RPCDBG_FACILITY        RPCDBG_AUTH
51 #endif
52
53 static LIST_HEAD(registered_mechs);
54 static DEFINE_SPINLOCK(registered_mechs_lock);
55
56 static void
57 gss_mech_free(struct gss_api_mech *gm)
58 {
59         struct pf_desc *pf;
60         int i;
61
62         for (i = 0; i < gm->gm_pf_num; i++) {
63                 pf = &gm->gm_pfs[i];
64                 kfree(pf->auth_domain_name);
65                 pf->auth_domain_name = NULL;
66         }
67 }
68
69 static inline char *
70 make_auth_domain_name(char *name)
71 {
72         static char     *prefix = "gss/";
73         char            *new;
74
75         new = kmalloc(strlen(name) + strlen(prefix) + 1, GFP_KERNEL);
76         if (new) {
77                 strcpy(new, prefix);
78                 strcat(new, name);
79         }
80         return new;
81 }
82
83 static int
84 gss_mech_svc_setup(struct gss_api_mech *gm)
85 {
86         struct pf_desc *pf;
87         int i, status;
88
89         for (i = 0; i < gm->gm_pf_num; i++) {
90                 pf = &gm->gm_pfs[i];
91                 pf->auth_domain_name = make_auth_domain_name(pf->name);
92                 status = -ENOMEM;
93                 if (pf->auth_domain_name == NULL)
94                         goto out;
95                 status = svcauth_gss_register_pseudoflavor(pf->pseudoflavor,
96                                                         pf->auth_domain_name);
97                 if (status)
98                         goto out;
99         }
100         return 0;
101 out:
102         gss_mech_free(gm);
103         return status;
104 }
105
106 /**
107  * gss_mech_register - register a GSS mechanism
108  * @gm: GSS mechanism handle
109  *
110  * Returns zero if successful, or a negative errno.
111  */
112 int gss_mech_register(struct gss_api_mech *gm)
113 {
114         int status;
115
116         status = gss_mech_svc_setup(gm);
117         if (status)
118                 return status;
119         spin_lock(&registered_mechs_lock);
120         list_add(&gm->gm_list, &registered_mechs);
121         spin_unlock(&registered_mechs_lock);
122         dprintk("RPC:       registered gss mechanism %s\n", gm->gm_name);
123         return 0;
124 }
125 EXPORT_SYMBOL_GPL(gss_mech_register);
126
127 /**
128  * gss_mech_unregister - release a GSS mechanism
129  * @gm: GSS mechanism handle
130  *
131  */
132 void gss_mech_unregister(struct gss_api_mech *gm)
133 {
134         spin_lock(&registered_mechs_lock);
135         list_del(&gm->gm_list);
136         spin_unlock(&registered_mechs_lock);
137         dprintk("RPC:       unregistered gss mechanism %s\n", gm->gm_name);
138         gss_mech_free(gm);
139 }
140 EXPORT_SYMBOL_GPL(gss_mech_unregister);
141
142 static struct gss_api_mech *gss_mech_get(struct gss_api_mech *gm)
143 {
144         __module_get(gm->gm_owner);
145         return gm;
146 }
147
148 static struct gss_api_mech *
149 _gss_mech_get_by_name(const char *name)
150 {
151         struct gss_api_mech     *pos, *gm = NULL;
152
153         spin_lock(&registered_mechs_lock);
154         list_for_each_entry(pos, &registered_mechs, gm_list) {
155                 if (0 == strcmp(name, pos->gm_name)) {
156                         if (try_module_get(pos->gm_owner))
157                                 gm = pos;
158                         break;
159                 }
160         }
161         spin_unlock(&registered_mechs_lock);
162         return gm;
163
164 }
165
166 struct gss_api_mech * gss_mech_get_by_name(const char *name)
167 {
168         struct gss_api_mech *gm = NULL;
169
170         gm = _gss_mech_get_by_name(name);
171         if (!gm) {
172                 request_module("rpc-auth-gss-%s", name);
173                 gm = _gss_mech_get_by_name(name);
174         }
175         return gm;
176 }
177
178 struct gss_api_mech *gss_mech_get_by_OID(struct rpcsec_gss_oid *obj)
179 {
180         struct gss_api_mech     *pos, *gm = NULL;
181         char buf[32];
182
183         if (sprint_oid(obj->data, obj->len, buf, sizeof(buf)) < 0)
184                 return NULL;
185         dprintk("RPC:       %s(%s)\n", __func__, buf);
186         request_module("rpc-auth-gss-%s", buf);
187
188         spin_lock(&registered_mechs_lock);
189         list_for_each_entry(pos, &registered_mechs, gm_list) {
190                 if (obj->len == pos->gm_oid.len) {
191                         if (0 == memcmp(obj->data, pos->gm_oid.data, obj->len)) {
192                                 if (try_module_get(pos->gm_owner))
193                                         gm = pos;
194                                 break;
195                         }
196                 }
197         }
198         spin_unlock(&registered_mechs_lock);
199         return gm;
200 }
201
202 static inline int
203 mech_supports_pseudoflavor(struct gss_api_mech *gm, u32 pseudoflavor)
204 {
205         int i;
206
207         for (i = 0; i < gm->gm_pf_num; i++) {
208                 if (gm->gm_pfs[i].pseudoflavor == pseudoflavor)
209                         return 1;
210         }
211         return 0;
212 }
213
214 static struct gss_api_mech *_gss_mech_get_by_pseudoflavor(u32 pseudoflavor)
215 {
216         struct gss_api_mech *gm = NULL, *pos;
217
218         spin_lock(&registered_mechs_lock);
219         list_for_each_entry(pos, &registered_mechs, gm_list) {
220                 if (!mech_supports_pseudoflavor(pos, pseudoflavor)) {
221                         module_put(pos->gm_owner);
222                         continue;
223                 }
224                 if (try_module_get(pos->gm_owner))
225                         gm = pos;
226                 break;
227         }
228         spin_unlock(&registered_mechs_lock);
229         return gm;
230 }
231
232 struct gss_api_mech *
233 gss_mech_get_by_pseudoflavor(u32 pseudoflavor)
234 {
235         struct gss_api_mech *gm;
236
237         gm = _gss_mech_get_by_pseudoflavor(pseudoflavor);
238
239         if (!gm) {
240                 request_module("rpc-auth-gss-%u", pseudoflavor);
241                 gm = _gss_mech_get_by_pseudoflavor(pseudoflavor);
242         }
243         return gm;
244 }
245
246 /**
247  * gss_mech_list_pseudoflavors - Discover registered GSS pseudoflavors
248  * @array: array to fill in
249  * @size: size of "array"
250  *
251  * Returns the number of array items filled in, or a negative errno.
252  *
253  * The returned array is not sorted by any policy.  Callers should not
254  * rely on the order of the items in the returned array.
255  */
256 int gss_mech_list_pseudoflavors(rpc_authflavor_t *array_ptr, int size)
257 {
258         struct gss_api_mech *pos = NULL;
259         int j, i = 0;
260
261         spin_lock(&registered_mechs_lock);
262         list_for_each_entry(pos, &registered_mechs, gm_list) {
263                 for (j = 0; j < pos->gm_pf_num; j++) {
264                         if (i >= size) {
265                                 spin_unlock(&registered_mechs_lock);
266                                 return -ENOMEM;
267                         }
268                         array_ptr[i++] = pos->gm_pfs[j].pseudoflavor;
269                 }
270         }
271         spin_unlock(&registered_mechs_lock);
272         return i;
273 }
274
275 /**
276  * gss_svc_to_pseudoflavor - map a GSS service number to a pseudoflavor
277  * @gm: GSS mechanism handle
278  * @qop: GSS quality-of-protection value
279  * @service: GSS service value
280  *
281  * Returns a matching security flavor, or RPC_AUTH_MAXFLAVOR if none is found.
282  */
283 rpc_authflavor_t gss_svc_to_pseudoflavor(struct gss_api_mech *gm, u32 qop,
284                                          u32 service)
285 {
286         int i;
287
288         for (i = 0; i < gm->gm_pf_num; i++) {
289                 if (gm->gm_pfs[i].qop == qop &&
290                     gm->gm_pfs[i].service == service) {
291                         return gm->gm_pfs[i].pseudoflavor;
292                 }
293         }
294         return RPC_AUTH_MAXFLAVOR;
295 }
296
297 /**
298  * gss_mech_info2flavor - look up a pseudoflavor given a GSS tuple
299  * @info: a GSS mech OID, quality of protection, and service value
300  *
301  * Returns a matching pseudoflavor, or RPC_AUTH_MAXFLAVOR if the tuple is
302  * not supported.
303  */
304 rpc_authflavor_t gss_mech_info2flavor(struct rpcsec_gss_info *info)
305 {
306         rpc_authflavor_t pseudoflavor;
307         struct gss_api_mech *gm;
308
309         gm = gss_mech_get_by_OID(&info->oid);
310         if (gm == NULL)
311                 return RPC_AUTH_MAXFLAVOR;
312
313         pseudoflavor = gss_svc_to_pseudoflavor(gm, info->qop, info->service);
314
315         gss_mech_put(gm);
316         return pseudoflavor;
317 }
318
319 /**
320  * gss_mech_flavor2info - look up a GSS tuple for a given pseudoflavor
321  * @pseudoflavor: GSS pseudoflavor to match
322  * @info: rpcsec_gss_info structure to fill in
323  *
324  * Returns zero and fills in "info" if pseudoflavor matches a
325  * supported mechanism.  Otherwise a negative errno is returned.
326  */
327 int gss_mech_flavor2info(rpc_authflavor_t pseudoflavor,
328                          struct rpcsec_gss_info *info)
329 {
330         struct gss_api_mech *gm;
331         int i;
332
333         gm = gss_mech_get_by_pseudoflavor(pseudoflavor);
334         if (gm == NULL)
335                 return -ENOENT;
336
337         for (i = 0; i < gm->gm_pf_num; i++) {
338                 if (gm->gm_pfs[i].pseudoflavor == pseudoflavor) {
339                         memcpy(info->oid.data, gm->gm_oid.data, gm->gm_oid.len);
340                         info->oid.len = gm->gm_oid.len;
341                         info->qop = gm->gm_pfs[i].qop;
342                         info->service = gm->gm_pfs[i].service;
343                         gss_mech_put(gm);
344                         return 0;
345                 }
346         }
347
348         gss_mech_put(gm);
349         return -ENOENT;
350 }
351
352 u32
353 gss_pseudoflavor_to_service(struct gss_api_mech *gm, u32 pseudoflavor)
354 {
355         int i;
356
357         for (i = 0; i < gm->gm_pf_num; i++) {
358                 if (gm->gm_pfs[i].pseudoflavor == pseudoflavor)
359                         return gm->gm_pfs[i].service;
360         }
361         return 0;
362 }
363
364 char *
365 gss_service_to_auth_domain_name(struct gss_api_mech *gm, u32 service)
366 {
367         int i;
368
369         for (i = 0; i < gm->gm_pf_num; i++) {
370                 if (gm->gm_pfs[i].service == service)
371                         return gm->gm_pfs[i].auth_domain_name;
372         }
373         return NULL;
374 }
375
376 void
377 gss_mech_put(struct gss_api_mech * gm)
378 {
379         if (gm)
380                 module_put(gm->gm_owner);
381 }
382
383 /* The mech could probably be determined from the token instead, but it's just
384  * as easy for now to pass it in. */
385 int
386 gss_import_sec_context(const void *input_token, size_t bufsize,
387                        struct gss_api_mech      *mech,
388                        struct gss_ctx           **ctx_id,
389                        time_t                   *endtime,
390                        gfp_t gfp_mask)
391 {
392         if (!(*ctx_id = kzalloc(sizeof(**ctx_id), gfp_mask)))
393                 return -ENOMEM;
394         (*ctx_id)->mech_type = gss_mech_get(mech);
395
396         return mech->gm_ops->gss_import_sec_context(input_token, bufsize,
397                                                 *ctx_id, endtime, gfp_mask);
398 }
399
400 /* gss_get_mic: compute a mic over message and return mic_token. */
401
402 u32
403 gss_get_mic(struct gss_ctx      *context_handle,
404             struct xdr_buf      *message,
405             struct xdr_netobj   *mic_token)
406 {
407          return context_handle->mech_type->gm_ops
408                 ->gss_get_mic(context_handle,
409                               message,
410                               mic_token);
411 }
412
413 /* gss_verify_mic: check whether the provided mic_token verifies message. */
414
415 u32
416 gss_verify_mic(struct gss_ctx           *context_handle,
417                struct xdr_buf           *message,
418                struct xdr_netobj        *mic_token)
419 {
420         return context_handle->mech_type->gm_ops
421                 ->gss_verify_mic(context_handle,
422                                  message,
423                                  mic_token);
424 }
425
426 /*
427  * This function is called from both the client and server code.
428  * Each makes guarantees about how much "slack" space is available
429  * for the underlying function in "buf"'s head and tail while
430  * performing the wrap.
431  *
432  * The client and server code allocate RPC_MAX_AUTH_SIZE extra
433  * space in both the head and tail which is available for use by
434  * the wrap function.
435  *
436  * Underlying functions should verify they do not use more than
437  * RPC_MAX_AUTH_SIZE of extra space in either the head or tail
438  * when performing the wrap.
439  */
440 u32
441 gss_wrap(struct gss_ctx *ctx_id,
442          int            offset,
443          struct xdr_buf *buf,
444          struct page    **inpages)
445 {
446         return ctx_id->mech_type->gm_ops
447                 ->gss_wrap(ctx_id, offset, buf, inpages);
448 }
449
450 u32
451 gss_unwrap(struct gss_ctx       *ctx_id,
452            int                  offset,
453            struct xdr_buf       *buf)
454 {
455         return ctx_id->mech_type->gm_ops
456                 ->gss_unwrap(ctx_id, offset, buf);
457 }
458
459
460 /* gss_delete_sec_context: free all resources associated with context_handle.
461  * Note this differs from the RFC 2744-specified prototype in that we don't
462  * bother returning an output token, since it would never be used anyway. */
463
464 u32
465 gss_delete_sec_context(struct gss_ctx   **context_handle)
466 {
467         dprintk("RPC:       gss_delete_sec_context deleting %p\n",
468                         *context_handle);
469
470         if (!*context_handle)
471                 return GSS_S_NO_CONTEXT;
472         if ((*context_handle)->internal_ctx_id)
473                 (*context_handle)->mech_type->gm_ops
474                         ->gss_delete_sec_context((*context_handle)
475                                                         ->internal_ctx_id);
476         gss_mech_put((*context_handle)->mech_type);
477         kfree(*context_handle);
478         *context_handle=NULL;
479         return GSS_S_COMPLETE;
480 }