xref: /linux/net/sunrpc/auth_gss/gss_mech_switch.c (revision 858259cf7d1c443c836a2022b78cb281f0a9b95e)
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 		if (pf->auth_domain_name)
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(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(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(gss_mech_get);
143 
144 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 EXPORT_SYMBOL(gss_mech_get_by_name);
163 
164 static inline int
165 mech_supports_pseudoflavor(struct gss_api_mech *gm, u32 pseudoflavor)
166 {
167 	int i;
168 
169 	for (i = 0; i < gm->gm_pf_num; i++) {
170 		if (gm->gm_pfs[i].pseudoflavor == pseudoflavor)
171 			return 1;
172 	}
173 	return 0;
174 }
175 
176 struct gss_api_mech *
177 gss_mech_get_by_pseudoflavor(u32 pseudoflavor)
178 {
179 	struct gss_api_mech *pos, *gm = NULL;
180 
181 	spin_lock(&registered_mechs_lock);
182 	list_for_each_entry(pos, &registered_mechs, gm_list) {
183 		if (!mech_supports_pseudoflavor(pos, pseudoflavor)) {
184 			module_put(pos->gm_owner);
185 			continue;
186 		}
187 		if (try_module_get(pos->gm_owner))
188 			gm = pos;
189 		break;
190 	}
191 	spin_unlock(&registered_mechs_lock);
192 	return gm;
193 }
194 
195 EXPORT_SYMBOL(gss_mech_get_by_pseudoflavor);
196 
197 u32
198 gss_pseudoflavor_to_service(struct gss_api_mech *gm, u32 pseudoflavor)
199 {
200 	int i;
201 
202 	for (i = 0; i < gm->gm_pf_num; i++) {
203 		if (gm->gm_pfs[i].pseudoflavor == pseudoflavor)
204 			return gm->gm_pfs[i].service;
205 	}
206 	return 0;
207 }
208 
209 EXPORT_SYMBOL(gss_pseudoflavor_to_service);
210 
211 char *
212 gss_service_to_auth_domain_name(struct gss_api_mech *gm, u32 service)
213 {
214 	int i;
215 
216 	for (i = 0; i < gm->gm_pf_num; i++) {
217 		if (gm->gm_pfs[i].service == service)
218 			return gm->gm_pfs[i].auth_domain_name;
219 	}
220 	return NULL;
221 }
222 
223 EXPORT_SYMBOL(gss_service_to_auth_domain_name);
224 
225 void
226 gss_mech_put(struct gss_api_mech * gm)
227 {
228 	module_put(gm->gm_owner);
229 }
230 
231 EXPORT_SYMBOL(gss_mech_put);
232 
233 /* The mech could probably be determined from the token instead, but it's just
234  * as easy for now to pass it in. */
235 int
236 gss_import_sec_context(const void *input_token, size_t bufsize,
237 		       struct gss_api_mech	*mech,
238 		       struct gss_ctx		**ctx_id)
239 {
240 	if (!(*ctx_id = kmalloc(sizeof(**ctx_id), GFP_KERNEL)))
241 		return GSS_S_FAILURE;
242 	memset(*ctx_id, 0, sizeof(**ctx_id));
243 	(*ctx_id)->mech_type = gss_mech_get(mech);
244 
245 	return mech->gm_ops
246 		->gss_import_sec_context(input_token, bufsize, *ctx_id);
247 }
248 
249 /* gss_get_mic: compute a mic over message and return mic_token. */
250 
251 u32
252 gss_get_mic(struct gss_ctx	*context_handle,
253 	    struct xdr_buf	*message,
254 	    struct xdr_netobj	*mic_token)
255 {
256 	 return context_handle->mech_type->gm_ops
257 		->gss_get_mic(context_handle,
258 			      message,
259 			      mic_token);
260 }
261 
262 /* gss_verify_mic: check whether the provided mic_token verifies message. */
263 
264 u32
265 gss_verify_mic(struct gss_ctx		*context_handle,
266 	       struct xdr_buf		*message,
267 	       struct xdr_netobj	*mic_token)
268 {
269 	return context_handle->mech_type->gm_ops
270 		->gss_verify_mic(context_handle,
271 				 message,
272 				 mic_token);
273 }
274 
275 u32
276 gss_wrap(struct gss_ctx	*ctx_id,
277 	 int		offset,
278 	 struct xdr_buf	*buf,
279 	 struct page	**inpages)
280 {
281 	return ctx_id->mech_type->gm_ops
282 		->gss_wrap(ctx_id, offset, buf, inpages);
283 }
284 
285 u32
286 gss_unwrap(struct gss_ctx	*ctx_id,
287 	   int			offset,
288 	   struct xdr_buf	*buf)
289 {
290 	return ctx_id->mech_type->gm_ops
291 		->gss_unwrap(ctx_id, offset, buf);
292 }
293 
294 
295 /* gss_delete_sec_context: free all resources associated with context_handle.
296  * Note this differs from the RFC 2744-specified prototype in that we don't
297  * bother returning an output token, since it would never be used anyway. */
298 
299 u32
300 gss_delete_sec_context(struct gss_ctx	**context_handle)
301 {
302 	dprintk("RPC:      gss_delete_sec_context deleting %p\n",
303 			*context_handle);
304 
305 	if (!*context_handle)
306 		return(GSS_S_NO_CONTEXT);
307 	if ((*context_handle)->internal_ctx_id != 0)
308 		(*context_handle)->mech_type->gm_ops
309 			->gss_delete_sec_context((*context_handle)
310 							->internal_ctx_id);
311 	if ((*context_handle)->mech_type)
312 		gss_mech_put((*context_handle)->mech_type);
313 	kfree(*context_handle);
314 	*context_handle=NULL;
315 	return GSS_S_COMPLETE;
316 }
317