xref: /freebsd/contrib/wpa/src/eap_peer/eap_methods.c (revision bb15ca603fa442c72dde3f3cb8b46db6970e3950)
1 /*
2  * EAP peer: Method registration
3  * Copyright (c) 2004-2007, Jouni Malinen <j@w1.fi>
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License version 2 as
7  * published by the Free Software Foundation.
8  *
9  * Alternatively, this software may be distributed under the terms of BSD
10  * license.
11  *
12  * See README and COPYING for more details.
13  */
14 
15 #include "includes.h"
16 #ifdef CONFIG_DYNAMIC_EAP_METHODS
17 #include <dlfcn.h>
18 #endif /* CONFIG_DYNAMIC_EAP_METHODS */
19 
20 #include "common.h"
21 #include "eap_i.h"
22 #include "eap_methods.h"
23 
24 
25 static struct eap_method *eap_methods = NULL;
26 
27 
28 /**
29  * eap_peer_get_eap_method - Get EAP method based on type number
30  * @vendor: EAP Vendor-Id (0 = IETF)
31  * @method: EAP type number
32  * Returns: Pointer to EAP method or %NULL if not found
33  */
34 const struct eap_method * eap_peer_get_eap_method(int vendor, EapType method)
35 {
36 	struct eap_method *m;
37 	for (m = eap_methods; m; m = m->next) {
38 		if (m->vendor == vendor && m->method == method)
39 			return m;
40 	}
41 	return NULL;
42 }
43 
44 
45 /**
46  * eap_peer_get_type - Get EAP type for the given EAP method name
47  * @name: EAP method name, e.g., TLS
48  * @vendor: Buffer for returning EAP Vendor-Id
49  * Returns: EAP method type or %EAP_TYPE_NONE if not found
50  *
51  * This function maps EAP type names into EAP type numbers based on the list of
52  * EAP methods included in the build.
53  */
54 EapType eap_peer_get_type(const char *name, int *vendor)
55 {
56 	struct eap_method *m;
57 	for (m = eap_methods; m; m = m->next) {
58 		if (os_strcmp(m->name, name) == 0) {
59 			*vendor = m->vendor;
60 			return m->method;
61 		}
62 	}
63 	*vendor = EAP_VENDOR_IETF;
64 	return EAP_TYPE_NONE;
65 }
66 
67 
68 /**
69  * eap_get_name - Get EAP method name for the given EAP type
70  * @vendor: EAP Vendor-Id (0 = IETF)
71  * @type: EAP method type
72  * Returns: EAP method name, e.g., TLS, or %NULL if not found
73  *
74  * This function maps EAP type numbers into EAP type names based on the list of
75  * EAP methods included in the build.
76  */
77 const char * eap_get_name(int vendor, EapType type)
78 {
79 	struct eap_method *m;
80 	for (m = eap_methods; m; m = m->next) {
81 		if (m->vendor == vendor && m->method == type)
82 			return m->name;
83 	}
84 	return NULL;
85 }
86 
87 
88 /**
89  * eap_get_names - Get space separated list of names for supported EAP methods
90  * @buf: Buffer for names
91  * @buflen: Buffer length
92  * Returns: Number of characters written into buf (not including nul
93  * termination)
94  */
95 size_t eap_get_names(char *buf, size_t buflen)
96 {
97 	char *pos, *end;
98 	struct eap_method *m;
99 	int ret;
100 
101 	if (buflen == 0)
102 		return 0;
103 
104 	pos = buf;
105 	end = pos + buflen;
106 
107 	for (m = eap_methods; m; m = m->next) {
108 		ret = os_snprintf(pos, end - pos, "%s%s",
109 				  m == eap_methods ? "" : " ", m->name);
110 		if (ret < 0 || ret >= end - pos)
111 			break;
112 		pos += ret;
113 	}
114 	buf[buflen - 1] = '\0';
115 
116 	return pos - buf;
117 }
118 
119 
120 /**
121  * eap_get_names_as_string_array - Get supported EAP methods as string array
122  * @num: Buffer for returning the number of items in array, not including %NULL
123  * terminator. This parameter can be %NULL if the length is not needed.
124  * Returns: A %NULL-terminated array of strings, or %NULL on error.
125  *
126  * This function returns the list of names for all supported EAP methods as an
127  * array of strings. The caller must free the returned array items and the
128  * array.
129  */
130 char ** eap_get_names_as_string_array(size_t *num)
131 {
132 	struct eap_method *m;
133 	size_t array_len = 0;
134 	char **array;
135 	int i = 0, j;
136 
137 	for (m = eap_methods; m; m = m->next)
138 		array_len++;
139 
140 	array = os_zalloc(sizeof(char *) * (array_len + 1));
141 	if (array == NULL)
142 		return NULL;
143 
144 	for (m = eap_methods; m; m = m->next) {
145 		array[i++] = os_strdup(m->name);
146 		if (array[i - 1] == NULL) {
147 			for (j = 0; j < i; j++)
148 				os_free(array[j]);
149 			os_free(array);
150 			return NULL;
151 		}
152 	}
153 	array[i] = NULL;
154 
155 	if (num)
156 		*num = array_len;
157 
158 	return array;
159 }
160 
161 
162 /**
163  * eap_peer_get_methods - Get a list of enabled EAP peer methods
164  * @count: Set to number of available methods
165  * Returns: List of enabled EAP peer methods
166  */
167 const struct eap_method * eap_peer_get_methods(size_t *count)
168 {
169 	int c = 0;
170 	struct eap_method *m;
171 
172 	for (m = eap_methods; m; m = m->next)
173 		c++;
174 
175 	*count = c;
176 	return eap_methods;
177 }
178 
179 
180 #ifdef CONFIG_DYNAMIC_EAP_METHODS
181 /**
182  * eap_peer_method_load - Load a dynamic EAP method library (shared object)
183  * @so: File path for the shared object file to load
184  * Returns: 0 on success, -1 on failure
185  */
186 int eap_peer_method_load(const char *so)
187 {
188 	void *handle;
189 	int (*dyn_init)(void);
190 	int ret;
191 
192 	handle = dlopen(so, RTLD_LAZY);
193 	if (handle == NULL) {
194 		wpa_printf(MSG_ERROR, "EAP: Failed to open dynamic EAP method "
195 			   "'%s': %s", so, dlerror());
196 		return -1;
197 	}
198 
199 	dyn_init = dlsym(handle, "eap_peer_method_dynamic_init");
200 	if (dyn_init == NULL) {
201 		dlclose(handle);
202 		wpa_printf(MSG_ERROR, "EAP: Invalid EAP method '%s' - no "
203 			   "eap_peer_method_dynamic_init()", so);
204 		return -1;
205 	}
206 
207 	ret = dyn_init();
208 	if (ret) {
209 		dlclose(handle);
210 		wpa_printf(MSG_ERROR, "EAP: Failed to add EAP method '%s' - "
211 			   "ret %d", so, ret);
212 		return ret;
213 	}
214 
215 	/* Store the handle for this shared object. It will be freed with
216 	 * dlclose() when the EAP method is unregistered. */
217 	eap_methods->dl_handle = handle;
218 
219 	wpa_printf(MSG_DEBUG, "EAP: Loaded dynamic EAP method: '%s'", so);
220 
221 	return 0;
222 }
223 
224 
225 /**
226  * eap_peer_method_unload - Unload a dynamic EAP method library (shared object)
227  * @method: Pointer to the dynamically loaded EAP method
228  * Returns: 0 on success, -1 on failure
229  *
230  * This function can be used to unload EAP methods that have been previously
231  * loaded with eap_peer_method_load(). Before unloading the method, all
232  * references to the method must be removed to make sure that no dereferences
233  * of freed memory will occur after unloading.
234  */
235 int eap_peer_method_unload(struct eap_method *method)
236 {
237 	struct eap_method *m, *prev;
238 	void *handle;
239 
240 	m = eap_methods;
241 	prev = NULL;
242 	while (m) {
243 		if (m == method)
244 			break;
245 		prev = m;
246 		m = m->next;
247 	}
248 
249 	if (m == NULL || m->dl_handle == NULL)
250 		return -1;
251 
252 	if (prev)
253 		prev->next = m->next;
254 	else
255 		eap_methods = m->next;
256 
257 	handle = m->dl_handle;
258 
259 	if (m->free)
260 		m->free(m);
261 	else
262 		eap_peer_method_free(m);
263 
264 	dlclose(handle);
265 
266 	return 0;
267 }
268 #endif /* CONFIG_DYNAMIC_EAP_METHODS */
269 
270 
271 /**
272  * eap_peer_method_alloc - Allocate EAP peer method structure
273  * @version: Version of the EAP peer method interface (set to
274  * EAP_PEER_METHOD_INTERFACE_VERSION)
275  * @vendor: EAP Vendor-ID (EAP_VENDOR_*) (0 = IETF)
276  * @method: EAP type number (EAP_TYPE_*)
277  * @name: Name of the method (e.g., "TLS")
278  * Returns: Allocated EAP method structure or %NULL on failure
279  *
280  * The returned structure should be freed with eap_peer_method_free() when it
281  * is not needed anymore.
282  */
283 struct eap_method * eap_peer_method_alloc(int version, int vendor,
284 					  EapType method, const char *name)
285 {
286 	struct eap_method *eap;
287 	eap = os_zalloc(sizeof(*eap));
288 	if (eap == NULL)
289 		return NULL;
290 	eap->version = version;
291 	eap->vendor = vendor;
292 	eap->method = method;
293 	eap->name = name;
294 	return eap;
295 }
296 
297 
298 /**
299  * eap_peer_method_free - Free EAP peer method structure
300  * @method: Method structure allocated with eap_peer_method_alloc()
301  */
302 void eap_peer_method_free(struct eap_method *method)
303 {
304 	os_free(method);
305 }
306 
307 
308 /**
309  * eap_peer_method_register - Register an EAP peer method
310  * @method: EAP method to register
311  * Returns: 0 on success, -1 on invalid method, or -2 if a matching EAP method
312  * has already been registered
313  *
314  * Each EAP peer method needs to call this function to register itself as a
315  * supported EAP method.
316  */
317 int eap_peer_method_register(struct eap_method *method)
318 {
319 	struct eap_method *m, *last = NULL;
320 
321 	if (method == NULL || method->name == NULL ||
322 	    method->version != EAP_PEER_METHOD_INTERFACE_VERSION)
323 		return -1;
324 
325 	for (m = eap_methods; m; m = m->next) {
326 		if ((m->vendor == method->vendor &&
327 		     m->method == method->method) ||
328 		    os_strcmp(m->name, method->name) == 0)
329 			return -2;
330 		last = m;
331 	}
332 
333 	if (last)
334 		last->next = method;
335 	else
336 		eap_methods = method;
337 
338 	return 0;
339 }
340 
341 
342 /**
343  * eap_peer_unregister_methods - Unregister EAP peer methods
344  *
345  * This function is called at program termination to unregister all EAP peer
346  * methods.
347  */
348 void eap_peer_unregister_methods(void)
349 {
350 	struct eap_method *m;
351 #ifdef CONFIG_DYNAMIC_EAP_METHODS
352 	void *handle;
353 #endif /* CONFIG_DYNAMIC_EAP_METHODS */
354 
355 	while (eap_methods) {
356 		m = eap_methods;
357 		eap_methods = eap_methods->next;
358 
359 #ifdef CONFIG_DYNAMIC_EAP_METHODS
360 		handle = m->dl_handle;
361 #endif /* CONFIG_DYNAMIC_EAP_METHODS */
362 
363 		if (m->free)
364 			m->free(m);
365 		else
366 			eap_peer_method_free(m);
367 
368 #ifdef CONFIG_DYNAMIC_EAP_METHODS
369 		if (handle)
370 			dlclose(handle);
371 #endif /* CONFIG_DYNAMIC_EAP_METHODS */
372 	}
373 }
374