events.c

WPA在Linux下实现的原代码 WPA在Linux下实现的原代码

/*
 * WPA Supplicant - Driver event processing
 * Copyright (c) 2003-2006, Jouni Malinen <[e-mail]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Alternatively, this software may be distributed under the terms of BSD
 * license.
 *
 * See README and COPYING for more details.
 */

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <time.h>

#include "common.h"
#include "eapol_sm.h"
#include "wpa.h"
#include "eloop.h"
#include "wpa_supplicant.h"
#include "config.h"
#include "l2_packet.h"
#include "wpa_supplicant_i.h"
#include "pcsc_funcs.h"
#include "preauth.h"
#include "wpa_ctrl.h"
#include "eap.h"


static int wpa_supplicant_select_config(struct wpa_supplicant *wpa_s)
{
	struct wpa_ssid *ssid;

	if (wpa_s->conf->ap_scan == 1 && wpa_s->current_ssid)
		return 0;

	ssid = wpa_supplicant_get_ssid(wpa_s);
	if (ssid == NULL) {
		wpa_printf(MSG_INFO, "No network configuration found for the "
			   "current AP");
		return -1;
	}

	if (ssid->disabled) {
		wpa_printf(MSG_DEBUG, "Selected network is disabled");
		return -1;
	}

	wpa_printf(MSG_DEBUG, "Network configuration found for the current "
		   "AP");
	if (ssid->key_mgmt & (WPA_KEY_MGMT_PSK | WPA_KEY_MGMT_IEEE8021X |
			      WPA_KEY_MGMT_WPA_NONE)) {
		u8 wpa_ie[80];
		size_t wpa_ie_len = sizeof(wpa_ie);
		wpa_supplicant_set_suites(wpa_s, NULL, ssid,
					  wpa_ie, &wpa_ie_len);
	} else {
		wpa_supplicant_set_non_wpa_policy(wpa_s, ssid);
	}

	if (wpa_s->current_ssid && wpa_s->current_ssid != ssid)
		eapol_sm_invalidate_cached_session(wpa_s->eapol);
	wpa_s->current_ssid = ssid;
	wpa_sm_set_config(wpa_s->wpa, wpa_s->current_ssid);
	wpa_supplicant_initiate_eapol(wpa_s);

	return 0;
}


static void wpa_supplicant_stop_countermeasures(void *eloop_ctx,
						void *sock_ctx)
{
	struct wpa_supplicant *wpa_s = eloop_ctx;

	if (wpa_s->countermeasures) {
		wpa_s->countermeasures = 0;
		wpa_drv_set_countermeasures(wpa_s, 0);
		wpa_msg(wpa_s, MSG_INFO, "WPA: TKIP countermeasures stopped");
		wpa_supplicant_req_scan(wpa_s, 0, 0);
	}
}


static void wpa_supplicant_mark_disassoc(struct wpa_supplicant *wpa_s)
{
	wpa_supplicant_set_state(wpa_s, WPA_DISCONNECTED);
	memset(wpa_s->bssid, 0, ETH_ALEN);
	eapol_sm_notify_portEnabled(wpa_s->eapol, FALSE);
	eapol_sm_notify_portValid(wpa_s->eapol, FALSE);
	if (wpa_s->key_mgmt == WPA_KEY_MGMT_PSK)
		eapol_sm_notify_eap_success(wpa_s->eapol, FALSE);
}


static void wpa_find_assoc_pmkid(struct wpa_supplicant *wpa_s)
{
	struct wpa_ie_data ie;
	int i, pmksa_set = -1;

	if (wpa_sm_parse_own_wpa_ie(wpa_s->wpa, &ie) < 0 ||
	    ie.pmkid == NULL)
		return;

	for (i = 0; i < ie.num_pmkid; i++) {
		pmksa_set = pmksa_cache_set_current(wpa_s->wpa,
						    ie.pmkid + i * PMKID_LEN,
						    NULL, NULL, 0);
		if (pmksa_set == 0) {
			eapol_sm_notify_pmkid_attempt(wpa_s->eapol, 1);
			break;
		}
	}

	wpa_printf(MSG_DEBUG, "RSN: PMKID from assoc IE %sfound from PMKSA "
		   "cache", pmksa_set == 0 ? "" : "not ");
}


static void wpa_supplicant_event_pmkid_candidate(struct wpa_supplicant *wpa_s,
						 union wpa_event_data *data)
{
	if (data == NULL) {
		wpa_printf(MSG_DEBUG, "RSN: No data in PMKID candidate event");
		return;
	}
	wpa_printf(MSG_DEBUG, "RSN: PMKID candidate event - bssid=" MACSTR
		   " index=%d preauth=%d",
		   MAC2STR(data->pmkid_candidate.bssid),
		   data->pmkid_candidate.index,
		   data->pmkid_candidate.preauth);

	pmksa_candidate_add(wpa_s->wpa, data->pmkid_candidate.bssid,
			    data->pmkid_candidate.index,
			    data->pmkid_candidate.preauth);
}


static int wpa_supplicant_dynamic_keys(struct wpa_supplicant *wpa_s)
{
	if (wpa_s->key_mgmt == WPA_KEY_MGMT_NONE ||
	    wpa_s->key_mgmt == WPA_KEY_MGMT_WPA_NONE)
		return 0;

	if (wpa_s->key_mgmt == WPA_KEY_MGMT_IEEE8021X_NO_WPA &&
	    wpa_s->current_ssid &&
	    !(wpa_s->current_ssid->eapol_flags &
	      (EAPOL_FLAG_REQUIRE_KEY_UNICAST |
	       EAPOL_FLAG_REQUIRE_KEY_BROADCAST))) {
		/* IEEE 802.1X, but not using dynamic WEP keys (i.e., either
		 * plaintext or static WEP keys). */
		return 0;
	}

	return 1;
}


/**
 * wpa_supplicant_scard_init - Initialize SIM/USIM access with PC/SC
 * @wpa_s: pointer to wpa_supplicant data
 * @ssid: Configuration data for the network
 * Returns: 0 on success, -1 on failure
 *
 * This function is called when starting authentication with a network that is
 * configured to use PC/SC for SIM/USIM access (EAP-SIM or EAP-AKA).
 */
int wpa_supplicant_scard_init(struct wpa_supplicant *wpa_s,
			      struct wpa_ssid *ssid)
{
	int aka = 0, sim = 0, type;

	if (ssid->pcsc == NULL || wpa_s->scard != NULL)
		return 0;

	if (ssid->eap_methods == NULL) {
		sim = 1;
		aka = 1;
	} else {
		u8 *eap = ssid->eap_methods;
		while (*eap != EAP_TYPE_NONE) {
			if (*eap == EAP_TYPE_SIM)
				sim = 1;
			else if (*eap == EAP_TYPE_AKA)
				aka = 1;
			eap++;
		}
	}

#ifndef EAP_SIM
	sim = 0;
#endif /* EAP_SIM */
#ifndef EAP_AKA
	aka = 0;
#endif /* EAP_AKA */

	if (!sim && !aka) {
		wpa_printf(MSG_DEBUG, "Selected network is configured to use "
			   "SIM, but neither EAP-SIM nor EAP-AKA are enabled");
		return 0;
	}

	wpa_printf(MSG_DEBUG, "Selected network is configured to use SIM "
		   "(sim=%d aka=%d) - initialize PCSC", sim, aka);
	if (sim && aka)
		type = SCARD_TRY_BOTH;
	else if (aka)
		type = SCARD_USIM_ONLY;
	else
		type = SCARD_GSM_SIM_ONLY;

	wpa_s->scard = scard_init(type);
	if (wpa_s->scard == NULL) {
		wpa_printf(MSG_WARNING, "Failed to initialize SIM "
			   "(pcsc-lite)");
		return -1;
	}
	wpa_sm_set_scard_ctx(wpa_s->wpa, wpa_s->scard);
	eapol_sm_register_scard_ctx(wpa_s->eapol, wpa_s->scard);

	return 0;
}


static int wpa_supplicant_match_privacy(struct wpa_scan_result *bss,
					struct wpa_ssid *ssid)
{
	int i, privacy = 0;

	for (i = 0; i < NUM_WEP_KEYS; i++) {
		if (ssid->wep_key_len[i]) {
			privacy = 1;
			break;
		}
	}
	if ((ssid->key_mgmt & WPA_KEY_MGMT_IEEE8021X_NO_WPA) &&
	    ssid->eapol_flags & (EAPOL_FLAG_REQUIRE_KEY_UNICAST |
				 EAPOL_FLAG_REQUIRE_KEY_BROADCAST))
		privacy = 1;

	if (bss->caps & IEEE80211_CAP_PRIVACY)
		return privacy;
	return !privacy;
}


static int wpa_supplicant_ssid_bss_match(struct wpa_ssid *ssid,
					 struct wpa_scan_result *bss)
{
	struct wpa_ie_data ie;
	int proto_match = 0;

	while ((ssid->proto & WPA_PROTO_RSN) && bss->rsn_ie_len > 0) {
		proto_match++;

		if (wpa_parse_wpa_ie(bss->rsn_ie, bss->rsn_ie_len, &ie)) {
			wpa_printf(MSG_DEBUG, "   skip RSN IE - parse failed");
			break;
		}
		if (!(ie.proto & ssid->proto)) {
			wpa_printf(MSG_DEBUG, "   skip RSN IE - proto "
				   "mismatch");
			break;
		}

		if (!(ie.pairwise_cipher & ssid->pairwise_cipher)) {
			wpa_printf(MSG_DEBUG, "   skip RSN IE - PTK cipher "
				   "mismatch");
			break;
		}

		if (!(ie.group_cipher & ssid->group_cipher)) {
			wpa_printf(MSG_DEBUG, "   skip RSN IE - GTK cipher "
				   "mismatch");
			break;
		}

		if (!(ie.key_mgmt & ssid->key_mgmt)) {
			wpa_printf(MSG_DEBUG, "   skip RSN IE - key mgmt "
				   "mismatch");
			break;
		}

		wpa_printf(MSG_DEBUG, "   selected based on RSN IE");
		return 1;
	}

	while ((ssid->proto & WPA_PROTO_WPA) && bss->wpa_ie_len > 0) {
		proto_match++;

		if (wpa_parse_wpa_ie(bss->wpa_ie, bss->wpa_ie_len, &ie)) {
			wpa_printf(MSG_DEBUG, "   skip WPA IE - parse failed");
			break;
		}
		if (!(ie.proto & ssid->proto)) {
			wpa_printf(MSG_DEBUG, "   skip WPA IE - proto "
				   "mismatch");
			break;
		}

		if (!(ie.pairwise_cipher & ssid->pairwise_cipher)) {
			wpa_printf(MSG_DEBUG, "   skip WPA IE - PTK cipher "
				   "mismatch");
			break;
		}

		if (!(ie.group_cipher & ssid->group_cipher)) {
			wpa_printf(MSG_DEBUG, "   skip WPA IE - GTK cipher "
				   "mismatch");
			break;
		}

		if (!(ie.key_mgmt & ssid->key_mgmt)) {
			wpa_printf(MSG_DEBUG, "   skip WPA IE - key mgmt "
				   "mismatch");
			break;
		}

		wpa_printf(MSG_DEBUG, "   selected based on WPA IE");
		return 1;
	}

	if (proto_match == 0)
		wpa_printf(MSG_DEBUG, "   skip - no WPA/RSN proto match");

	return 0;
}


static struct wpa_scan_result *
wpa_supplicant_select_bss(struct wpa_supplicant *wpa_s, struct wpa_ssid *group,
			  struct wpa_scan_result *results, int num,
			  struct wpa_ssid **selected_ssid)
{
	struct wpa_ssid *ssid;
	struct wpa_scan_result *bss, *selected = NULL;
	int i;
	struct wpa_blacklist *e;

	wpa_printf(MSG_DEBUG, "Selecting BSS from priority group %d",
		   group->priority);

	bss = NULL;
	ssid = NULL;
	/* First, try to find WPA-enabled AP */
	for (i = 0; i < num && !selected; i++) {
		bss = &results[i];
		wpa_printf(MSG_DEBUG, "%d: " MACSTR " ssid='%s' "
			   "wpa_ie_len=%lu rsn_ie_len=%lu caps=0x%x",
			   i, MAC2STR(bss->bssid),
			   wpa_ssid_txt(bss->ssid, bss->ssid_len),
			   (unsigned long) bss->wpa_ie_len,
			   (unsigned long) bss->rsn_ie_len, bss->caps);
		if ((e = wpa_blacklist_get(wpa_s, bss->bssid)) &&
		    e->count > 1) {
			wpa_printf(MSG_DEBUG, "   skip - blacklisted");
			continue;
		}

		if (bss->wpa_ie_len == 0 && bss->rsn_ie_len == 0) {
			wpa_printf(MSG_DEBUG, "   skip - no WPA/RSN IE");
			continue;
		}

		for (ssid = group; ssid; ssid = ssid->pnext) {
			if (ssid->disabled)
				continue;
			if (bss->ssid_len != ssid->ssid_len ||
			    memcmp(bss->ssid, ssid->ssid,
				   bss->ssid_len) != 0) {
				wpa_printf(MSG_DEBUG, "   skip - "
					   "SSID mismatch");
				continue;
			}
			if (ssid->bssid_set &&
			    memcmp(bss->bssid, ssid->bssid, ETH_ALEN) != 0) {
				wpa_printf(MSG_DEBUG, "   skip - "
					   "BSSID mismatch");