NFS: Determine initial mount security
[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 EXPORT_SYMBOL_GPL(gss_mech_get_by_name);
162
163 struct gss_api_mech *
164 gss_mech_get_by_OID(struct xdr_netobj *obj)
165 {
166         struct gss_api_mech     *pos, *gm = NULL;
167
168         spin_lock(&registered_mechs_lock);
169         list_for_each_entry(pos, &registered_mechs, gm_list) {
170                 if (obj->len == pos->gm_oid.len) {
171                         if (0 == memcmp(obj->data, pos->gm_oid.data, obj->len)) {
172                                 if (try_module_get(pos->gm_owner))
173                                         gm = pos;
174                                 break;
175                         }
176                 }
177         }
178         spin_unlock(&registered_mechs_lock);
179         return gm;
180
181 }
182
183 EXPORT_SYMBOL_GPL(gss_mech_get_by_OID);
184
185 static inline int
186 mech_supports_pseudoflavor(struct gss_api_mech *gm, u32 pseudoflavor)
187 {
188         int i;
189
190         for (i = 0; i < gm->gm_pf_num; i++) {
191                 if (gm->gm_pfs[i].pseudoflavor == pseudoflavor)
192                         return 1;
193         }
194         return 0;
195 }
196
197 struct gss_api_mech *
198 gss_mech_get_by_pseudoflavor(u32 pseudoflavor)
199 {
200         struct gss_api_mech *pos, *gm = NULL;
201
202         spin_lock(&registered_mechs_lock);
203         list_for_each_entry(pos, &registered_mechs, gm_list) {
204                 if (!mech_supports_pseudoflavor(pos, pseudoflavor)) {
205                         module_put(pos->gm_owner);
206                         continue;
207                 }
208                 if (try_module_get(pos->gm_owner))
209                         gm = pos;
210                 break;
211         }
212         spin_unlock(&registered_mechs_lock);
213         return gm;
214 }
215
216 EXPORT_SYMBOL_GPL(gss_mech_get_by_pseudoflavor);
217
218 int gss_mech_list_pseudoflavors(rpc_authflavor_t *array_ptr)
219 {
220         struct gss_api_mech *pos = NULL;
221         int i = 0;
222
223         spin_lock(&registered_mechs_lock);
224         list_for_each_entry(pos, &registered_mechs, gm_list) {
225                 array_ptr[i] = pos->gm_pfs->pseudoflavor;
226                 i++;
227         }
228         spin_unlock(&registered_mechs_lock);
229         return i;
230 }
231
232 EXPORT_SYMBOL_GPL(gss_mech_list_pseudoflavors);
233
234 u32
235 gss_svc_to_pseudoflavor(struct gss_api_mech *gm, u32 service)
236 {
237         int i;
238
239         for (i = 0; i < gm->gm_pf_num; i++) {
240                 if (gm->gm_pfs[i].service == service) {
241                         return gm->gm_pfs[i].pseudoflavor;
242                 }
243         }
244         return RPC_AUTH_MAXFLAVOR; /* illegal value */
245 }
246 EXPORT_SYMBOL_GPL(gss_svc_to_pseudoflavor);
247
248 u32
249 gss_pseudoflavor_to_service(struct gss_api_mech *gm, u32 pseudoflavor)
250 {
251         int i;
252
253         for (i = 0; i < gm->gm_pf_num; i++) {
254                 if (gm->gm_pfs[i].pseudoflavor == pseudoflavor)
255                         return gm->gm_pfs[i].service;
256         }
257         return 0;
258 }
259
260 EXPORT_SYMBOL_GPL(gss_pseudoflavor_to_service);
261
262 char *
263 gss_service_to_auth_domain_name(struct gss_api_mech *gm, u32 service)
264 {
265         int i;
266
267         for (i = 0; i < gm->gm_pf_num; i++) {
268                 if (gm->gm_pfs[i].service == service)
269                         return gm->gm_pfs[i].auth_domain_name;
270         }
271         return NULL;
272 }
273
274 EXPORT_SYMBOL_GPL(gss_service_to_auth_domain_name);
275
276 void
277 gss_mech_put(struct gss_api_mech * gm)
278 {
279         if (gm)
280                 module_put(gm->gm_owner);
281 }
282
283 EXPORT_SYMBOL_GPL(gss_mech_put);
284
285 /* The mech could probably be determined from the token instead, but it's just
286  * as easy for now to pass it in. */
287 int
288 gss_import_sec_context(const void *input_token, size_t bufsize,
289                        struct gss_api_mech      *mech,
290                        struct gss_ctx           **ctx_id,
291                        gfp_t gfp_mask)
292 {
293         if (!(*ctx_id = kzalloc(sizeof(**ctx_id), gfp_mask)))
294                 return -ENOMEM;
295         (*ctx_id)->mech_type = gss_mech_get(mech);
296
297         return mech->gm_ops
298                 ->gss_import_sec_context(input_token, bufsize, *ctx_id, gfp_mask);
299 }
300
301 /* gss_get_mic: compute a mic over message and return mic_token. */
302
303 u32
304 gss_get_mic(struct gss_ctx      *context_handle,
305             struct xdr_buf      *message,
306             struct xdr_netobj   *mic_token)
307 {
308          return context_handle->mech_type->gm_ops
309                 ->gss_get_mic(context_handle,
310                               message,
311                               mic_token);
312 }
313
314 /* gss_verify_mic: check whether the provided mic_token verifies message. */
315
316 u32
317 gss_verify_mic(struct gss_ctx           *context_handle,
318                struct xdr_buf           *message,
319                struct xdr_netobj        *mic_token)
320 {
321         return context_handle->mech_type->gm_ops
322                 ->gss_verify_mic(context_handle,
323                                  message,
324                                  mic_token);
325 }
326
327 /*
328  * This function is called from both the client and server code.
329  * Each makes guarantees about how much "slack" space is available
330  * for the underlying function in "buf"'s head and tail while
331  * performing the wrap.
332  *
333  * The client and server code allocate RPC_MAX_AUTH_SIZE extra
334  * space in both the head and tail which is available for use by
335  * the wrap function.
336  *
337  * Underlying functions should verify they do not use more than
338  * RPC_MAX_AUTH_SIZE of extra space in either the head or tail
339  * when performing the wrap.
340  */
341 u32
342 gss_wrap(struct gss_ctx *ctx_id,
343          int            offset,
344          struct xdr_buf *buf,
345          struct page    **inpages)
346 {
347         return ctx_id->mech_type->gm_ops
348                 ->gss_wrap(ctx_id, offset, buf, inpages);
349 }
350
351 u32
352 gss_unwrap(struct gss_ctx       *ctx_id,
353            int                  offset,
354            struct xdr_buf       *buf)
355 {
356         return ctx_id->mech_type->gm_ops
357                 ->gss_unwrap(ctx_id, offset, buf);
358 }
359
360
361 /* gss_delete_sec_context: free all resources associated with context_handle.
362  * Note this differs from the RFC 2744-specified prototype in that we don't
363  * bother returning an output token, since it would never be used anyway. */
364
365 u32
366 gss_delete_sec_context(struct gss_ctx   **context_handle)
367 {
368         dprintk("RPC:       gss_delete_sec_context deleting %p\n",
369                         *context_handle);
370
371         if (!*context_handle)
372                 return GSS_S_NO_CONTEXT;
373         if ((*context_handle)->internal_ctx_id)
374                 (*context_handle)->mech_type->gm_ops
375                         ->gss_delete_sec_context((*context_handle)
376                                                         ->internal_ctx_id);
377         gss_mech_put((*context_handle)->mech_type);
378         kfree(*context_handle);
379         *context_handle=NULL;
380         return GSS_S_COMPLETE;
381 }