SUNRPC: Refactor nfsd4_do_encode_secinfo()
[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 int
107 gss_mech_register(struct gss_api_mech *gm)
108 {
109         int status;
110
111         status = gss_mech_svc_setup(gm);
112         if (status)
113                 return status;
114         spin_lock(&registered_mechs_lock);
115         list_add(&gm->gm_list, &registered_mechs);
116         spin_unlock(&registered_mechs_lock);
117         dprintk("RPC:       registered gss mechanism %s\n", gm->gm_name);
118         return 0;
119 }
120
121 EXPORT_SYMBOL_GPL(gss_mech_register);
122
123 void
124 gss_mech_unregister(struct gss_api_mech *gm)
125 {
126         spin_lock(&registered_mechs_lock);
127         list_del(&gm->gm_list);
128         spin_unlock(&registered_mechs_lock);
129         dprintk("RPC:       unregistered gss mechanism %s\n", gm->gm_name);
130         gss_mech_free(gm);
131 }
132
133 EXPORT_SYMBOL_GPL(gss_mech_unregister);
134
135 struct gss_api_mech *
136 gss_mech_get(struct gss_api_mech *gm)
137 {
138         __module_get(gm->gm_owner);
139         return gm;
140 }
141
142 EXPORT_SYMBOL_GPL(gss_mech_get);
143
144 static struct gss_api_mech *
145 _gss_mech_get_by_name(const char *name)
146 {
147         struct gss_api_mech     *pos, *gm = NULL;
148
149         spin_lock(&registered_mechs_lock);
150         list_for_each_entry(pos, &registered_mechs, gm_list) {
151                 if (0 == strcmp(name, pos->gm_name)) {
152                         if (try_module_get(pos->gm_owner))
153                                 gm = pos;
154                         break;
155                 }
156         }
157         spin_unlock(&registered_mechs_lock);
158         return gm;
159
160 }
161
162 struct gss_api_mech * gss_mech_get_by_name(const char *name)
163 {
164         struct gss_api_mech *gm = NULL;
165
166         gm = _gss_mech_get_by_name(name);
167         if (!gm) {
168                 request_module("rpc-auth-gss-%s", name);
169                 gm = _gss_mech_get_by_name(name);
170         }
171         return gm;
172 }
173 EXPORT_SYMBOL_GPL(gss_mech_get_by_name);
174
175 static struct gss_api_mech *gss_mech_get_by_OID(struct rpcsec_gss_oid *obj)
176 {
177         struct gss_api_mech     *pos, *gm = NULL;
178         char buf[32];
179
180         if (sprint_oid(obj->data, obj->len, buf, sizeof(buf)) < 0)
181                 return NULL;
182         dprintk("RPC:       %s(%s)\n", __func__, buf);
183         request_module("rpc-auth-gss-%s", buf);
184
185         spin_lock(&registered_mechs_lock);
186         list_for_each_entry(pos, &registered_mechs, gm_list) {
187                 if (obj->len == pos->gm_oid.len) {
188                         if (0 == memcmp(obj->data, pos->gm_oid.data, obj->len)) {
189                                 if (try_module_get(pos->gm_owner))
190                                         gm = pos;
191                                 break;
192                         }
193                 }
194         }
195         spin_unlock(&registered_mechs_lock);
196         return gm;
197 }
198
199 static inline int
200 mech_supports_pseudoflavor(struct gss_api_mech *gm, u32 pseudoflavor)
201 {
202         int i;
203
204         for (i = 0; i < gm->gm_pf_num; i++) {
205                 if (gm->gm_pfs[i].pseudoflavor == pseudoflavor)
206                         return 1;
207         }
208         return 0;
209 }
210
211 static struct gss_api_mech *_gss_mech_get_by_pseudoflavor(u32 pseudoflavor)
212 {
213         struct gss_api_mech *gm = NULL, *pos;
214
215         spin_lock(&registered_mechs_lock);
216         list_for_each_entry(pos, &registered_mechs, gm_list) {
217                 if (!mech_supports_pseudoflavor(pos, pseudoflavor)) {
218                         module_put(pos->gm_owner);
219                         continue;
220                 }
221                 if (try_module_get(pos->gm_owner))
222                         gm = pos;
223                 break;
224         }
225         spin_unlock(&registered_mechs_lock);
226         return gm;
227 }
228
229 struct gss_api_mech *
230 gss_mech_get_by_pseudoflavor(u32 pseudoflavor)
231 {
232         struct gss_api_mech *gm;
233
234         gm = _gss_mech_get_by_pseudoflavor(pseudoflavor);
235
236         if (!gm) {
237                 request_module("rpc-auth-gss-%u", pseudoflavor);
238                 gm = _gss_mech_get_by_pseudoflavor(pseudoflavor);
239         }
240         return gm;
241 }
242
243 /**
244  * gss_mech_list_pseudoflavors - Discover registered GSS pseudoflavors
245  * @array: array to fill in
246  * @size: size of "array"
247  *
248  * Returns the number of array items filled in, or a negative errno.
249  *
250  * The returned array is not sorted by any policy.  Callers should not
251  * rely on the order of the items in the returned array.
252  */
253 int gss_mech_list_pseudoflavors(rpc_authflavor_t *array_ptr, int size)
254 {
255         struct gss_api_mech *pos = NULL;
256         int j, i = 0;
257
258         spin_lock(&registered_mechs_lock);
259         list_for_each_entry(pos, &registered_mechs, gm_list) {
260                 for (j = 0; j < pos->gm_pf_num; j++) {
261                         if (i >= size) {
262                                 spin_unlock(&registered_mechs_lock);
263                                 return -ENOMEM;
264                         }
265                         array_ptr[i++] = pos->gm_pfs[j].pseudoflavor;
266                 }
267         }
268         spin_unlock(&registered_mechs_lock);
269         return i;
270 }
271
272 /**
273  * gss_svc_to_pseudoflavor - map a GSS service number to a pseudoflavor
274  * @gm: GSS mechanism handle
275  * @qop: GSS quality-of-protection value
276  * @service: GSS service value
277  *
278  * Returns a matching security flavor, or RPC_AUTH_MAXFLAVOR if none is found.
279  */
280 rpc_authflavor_t gss_svc_to_pseudoflavor(struct gss_api_mech *gm, u32 qop,
281                                          u32 service)
282 {
283         int i;
284
285         for (i = 0; i < gm->gm_pf_num; i++) {
286                 if (gm->gm_pfs[i].qop == qop &&
287                     gm->gm_pfs[i].service == service) {
288                         return gm->gm_pfs[i].pseudoflavor;
289                 }
290         }
291         return RPC_AUTH_MAXFLAVOR;
292 }
293
294 /**
295  * gss_mech_info2flavor - look up a pseudoflavor given a GSS tuple
296  * @info: a GSS mech OID, quality of protection, and service value
297  *
298  * Returns a matching pseudoflavor, or RPC_AUTH_MAXFLAVOR if the tuple is
299  * not supported.
300  */
301 rpc_authflavor_t gss_mech_info2flavor(struct rpcsec_gss_info *info)
302 {
303         rpc_authflavor_t pseudoflavor;
304         struct gss_api_mech *gm;
305
306         gm = gss_mech_get_by_OID(&info->oid);
307         if (gm == NULL)
308                 return RPC_AUTH_MAXFLAVOR;
309
310         pseudoflavor = gss_svc_to_pseudoflavor(gm, info->qop, info->service);
311
312         gss_mech_put(gm);
313         return pseudoflavor;
314 }
315
316 /**
317  * gss_mech_flavor2info - look up a GSS tuple for a given pseudoflavor
318  * @pseudoflavor: GSS pseudoflavor to match
319  * @info: rpcsec_gss_info structure to fill in
320  *
321  * Returns zero and fills in "info" if pseudoflavor matches a
322  * supported mechanism.  Otherwise a negative errno is returned.
323  */
324 int gss_mech_flavor2info(rpc_authflavor_t pseudoflavor,
325                          struct rpcsec_gss_info *info)
326 {
327         struct gss_api_mech *gm;
328         int i;
329
330         gm = gss_mech_get_by_pseudoflavor(pseudoflavor);
331         if (gm == NULL)
332                 return -ENOENT;
333
334         for (i = 0; i < gm->gm_pf_num; i++) {
335                 if (gm->gm_pfs[i].pseudoflavor == pseudoflavor) {
336                         memcpy(info->oid.data, gm->gm_oid.data, gm->gm_oid.len);
337                         info->oid.len = gm->gm_oid.len;
338                         info->qop = gm->gm_pfs[i].qop;
339                         info->service = gm->gm_pfs[i].service;
340                         gss_mech_put(gm);
341                         return 0;
342                 }
343         }
344
345         gss_mech_put(gm);
346         return -ENOENT;
347 }
348
349 u32
350 gss_pseudoflavor_to_service(struct gss_api_mech *gm, u32 pseudoflavor)
351 {
352         int i;
353
354         for (i = 0; i < gm->gm_pf_num; i++) {
355                 if (gm->gm_pfs[i].pseudoflavor == pseudoflavor)
356                         return gm->gm_pfs[i].service;
357         }
358         return 0;
359 }
360
361 EXPORT_SYMBOL_GPL(gss_pseudoflavor_to_service);
362
363 char *
364 gss_service_to_auth_domain_name(struct gss_api_mech *gm, u32 service)
365 {
366         int i;
367
368         for (i = 0; i < gm->gm_pf_num; i++) {
369                 if (gm->gm_pfs[i].service == service)
370                         return gm->gm_pfs[i].auth_domain_name;
371         }
372         return NULL;
373 }
374
375 EXPORT_SYMBOL_GPL(gss_service_to_auth_domain_name);
376
377 void
378 gss_mech_put(struct gss_api_mech * gm)
379 {
380         if (gm)
381                 module_put(gm->gm_owner);
382 }
383
384 EXPORT_SYMBOL_GPL(gss_mech_put);
385
386 /* The mech could probably be determined from the token instead, but it's just
387  * as easy for now to pass it in. */
388 int
389 gss_import_sec_context(const void *input_token, size_t bufsize,
390                        struct gss_api_mech      *mech,
391                        struct gss_ctx           **ctx_id,
392                        gfp_t gfp_mask)
393 {
394         if (!(*ctx_id = kzalloc(sizeof(**ctx_id), gfp_mask)))
395                 return -ENOMEM;
396         (*ctx_id)->mech_type = gss_mech_get(mech);
397
398         return mech->gm_ops
399                 ->gss_import_sec_context(input_token, bufsize, *ctx_id, gfp_mask);
400 }
401
402 /* gss_get_mic: compute a mic over message and return mic_token. */
403
404 u32
405 gss_get_mic(struct gss_ctx      *context_handle,
406             struct xdr_buf      *message,
407             struct xdr_netobj   *mic_token)
408 {
409          return context_handle->mech_type->gm_ops
410                 ->gss_get_mic(context_handle,
411                               message,
412                               mic_token);
413 }
414
415 /* gss_verify_mic: check whether the provided mic_token verifies message. */
416
417 u32
418 gss_verify_mic(struct gss_ctx           *context_handle,
419                struct xdr_buf           *message,
420                struct xdr_netobj        *mic_token)
421 {
422         return context_handle->mech_type->gm_ops
423                 ->gss_verify_mic(context_handle,
424                                  message,
425                                  mic_token);
426 }
427
428 /*
429  * This function is called from both the client and server code.
430  * Each makes guarantees about how much "slack" space is available
431  * for the underlying function in "buf"'s head and tail while
432  * performing the wrap.
433  *
434  * The client and server code allocate RPC_MAX_AUTH_SIZE extra
435  * space in both the head and tail which is available for use by
436  * the wrap function.
437  *
438  * Underlying functions should verify they do not use more than
439  * RPC_MAX_AUTH_SIZE of extra space in either the head or tail
440  * when performing the wrap.
441  */
442 u32
443 gss_wrap(struct gss_ctx *ctx_id,
444          int            offset,
445          struct xdr_buf *buf,
446          struct page    **inpages)
447 {
448         return ctx_id->mech_type->gm_ops
449                 ->gss_wrap(ctx_id, offset, buf, inpages);
450 }
451
452 u32
453 gss_unwrap(struct gss_ctx       *ctx_id,
454            int                  offset,
455            struct xdr_buf       *buf)
456 {
457         return ctx_id->mech_type->gm_ops
458                 ->gss_unwrap(ctx_id, offset, buf);
459 }
460
461
462 /* gss_delete_sec_context: free all resources associated with context_handle.
463  * Note this differs from the RFC 2744-specified prototype in that we don't
464  * bother returning an output token, since it would never be used anyway. */
465
466 u32
467 gss_delete_sec_context(struct gss_ctx   **context_handle)
468 {
469         dprintk("RPC:       gss_delete_sec_context deleting %p\n",
470                         *context_handle);
471
472         if (!*context_handle)
473                 return GSS_S_NO_CONTEXT;
474         if ((*context_handle)->internal_ctx_id)
475                 (*context_handle)->mech_type->gm_ops
476                         ->gss_delete_sec_context((*context_handle)
477                                                         ->internal_ctx_id);
478         gss_mech_put((*context_handle)->mech_type);
479         kfree(*context_handle);
480         *context_handle=NULL;
481         return GSS_S_COMPLETE;
482 }