src/eap_peer/eap_methods.c

   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 }