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