hostap/src/ap/preauth_auth.c

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/*
* hostapd - Authenticator for IEEE 802.11i RSN pre-authentication
* Copyright (c) 2004-2007, Jouni Malinen <j@w1.fi>
*
* This software may be distributed under the terms of the BSD license.
* See README for more details.
*/
#include "utils/includes.h"
#ifdef CONFIG_RSN_PREAUTH
#include "utils/common.h"
#include "utils/eloop.h"
#include "l2_packet/l2_packet.h"
#include "common/wpa_common.h"
#include "eapol_auth/eapol_auth_sm.h"
#include "eapol_auth/eapol_auth_sm_i.h"
#include "hostapd.h"
#include "ap_config.h"
#include "ieee802_1x.h"
#include "sta_info.h"
#include "wpa_auth.h"
#include "preauth_auth.h"
#ifndef ETH_P_PREAUTH
#define ETH_P_PREAUTH 0x88C7 /* IEEE 802.11i pre-authentication */
#endif /* ETH_P_PREAUTH */
static const int dot11RSNAConfigPMKLifetime = 43200;
struct rsn_preauth_interface {
struct rsn_preauth_interface *next;
struct hostapd_data *hapd;
struct l2_packet_data *l2;
char *ifname;
int ifindex;
};
static void rsn_preauth_receive(void *ctx, const u8 *src_addr,
const u8 *buf, size_t len)
{
struct rsn_preauth_interface *piface = ctx;
struct hostapd_data *hapd = piface->hapd;
struct ieee802_1x_hdr *hdr;
struct sta_info *sta;
struct l2_ethhdr *ethhdr;
wpa_printf(MSG_DEBUG, "RSN: receive pre-auth packet "
"from interface '%s'", piface->ifname);
if (len < sizeof(*ethhdr) + sizeof(*hdr)) {
wpa_printf(MSG_DEBUG, "RSN: too short pre-auth packet "
"(len=%lu)", (unsigned long) len);
return;
}
ethhdr = (struct l2_ethhdr *) buf;
hdr = (struct ieee802_1x_hdr *) (ethhdr + 1);
if (os_memcmp(ethhdr->h_dest, hapd->own_addr, ETH_ALEN) != 0) {
wpa_printf(MSG_DEBUG, "RSN: pre-auth for foreign address "
MACSTR, MAC2STR(ethhdr->h_dest));
return;
}
sta = ap_get_sta(hapd, ethhdr->h_source);
if (sta && (sta->flags & WLAN_STA_ASSOC)) {
wpa_printf(MSG_DEBUG, "RSN: pre-auth for already association "
"STA " MACSTR, MAC2STR(sta->addr));
return;
}
if (!sta && hdr->type == IEEE802_1X_TYPE_EAPOL_START) {
sta = ap_sta_add(hapd, ethhdr->h_source);
if (sta == NULL)
return;
sta->flags = WLAN_STA_PREAUTH;
ieee802_1x_new_station(hapd, sta);
if (sta->eapol_sm == NULL) {
ap_free_sta(hapd, sta);
sta = NULL;
} else {
sta->eapol_sm->radius_identifier = -1;
sta->eapol_sm->portValid = true;
sta->eapol_sm->flags |= EAPOL_SM_PREAUTH;
}
}
if (sta == NULL)
return;
sta->preauth_iface = piface;
ieee802_1x_receive(hapd, ethhdr->h_source, (u8 *) (ethhdr + 1),
len - sizeof(*ethhdr));
}
static int rsn_preauth_iface_add(struct hostapd_data *hapd, const char *ifname)
{
struct rsn_preauth_interface *piface;
wpa_printf(MSG_DEBUG, "RSN pre-auth interface '%s'", ifname);
piface = os_zalloc(sizeof(*piface));
if (piface == NULL)
return -1;
piface->hapd = hapd;
piface->ifname = os_strdup(ifname);
if (piface->ifname == NULL) {
goto fail1;
}
piface->l2 = l2_packet_init(piface->ifname, NULL, ETH_P_PREAUTH,
rsn_preauth_receive, piface, 1);
if (piface->l2 == NULL) {
wpa_printf(MSG_ERROR, "Failed to open register layer 2 access "
"to ETH_P_PREAUTH");
goto fail2;
}
piface->next = hapd->preauth_iface;
hapd->preauth_iface = piface;
return 0;
fail2:
os_free(piface->ifname);
fail1:
os_free(piface);
return -1;
}
void rsn_preauth_iface_deinit(struct hostapd_data *hapd)
{
struct rsn_preauth_interface *piface, *prev;
piface = hapd->preauth_iface;
hapd->preauth_iface = NULL;
while (piface) {
prev = piface;
piface = piface->next;
l2_packet_deinit(prev->l2);
os_free(prev->ifname);
os_free(prev);
}
}
int rsn_preauth_iface_init(struct hostapd_data *hapd)
{
char *tmp, *start, *end;
if (hapd->conf->rsn_preauth_interfaces == NULL)
return 0;
tmp = os_strdup(hapd->conf->rsn_preauth_interfaces);
if (tmp == NULL)
return -1;
start = tmp;
for (;;) {
while (*start == ' ')
start++;
if (*start == '\0')
break;
end = os_strchr(start, ' ');
if (end)
*end = '\0';
if (rsn_preauth_iface_add(hapd, start)) {
rsn_preauth_iface_deinit(hapd);
os_free(tmp);
return -1;
}
if (end)
start = end + 1;
else
break;
}
os_free(tmp);
return 0;
}
static void rsn_preauth_finished_cb(void *eloop_ctx, void *timeout_ctx)
{
struct hostapd_data *hapd = eloop_ctx;
struct sta_info *sta = timeout_ctx;
wpa_printf(MSG_DEBUG, "RSN: Removing pre-authentication STA entry for "
MACSTR, MAC2STR(sta->addr));
ap_free_sta(hapd, sta);
}
void rsn_preauth_finished(struct hostapd_data *hapd, struct sta_info *sta,
int success)
{
const u8 *key;
size_t len;
hostapd_logger(hapd, sta->addr, HOSTAPD_MODULE_WPA,
HOSTAPD_LEVEL_INFO, "pre-authentication %s",
success ? "succeeded" : "failed");
key = ieee802_1x_get_key(sta->eapol_sm, &len);
if (len > PMK_LEN)
len = PMK_LEN;
if (success && key) {
if (wpa_auth_pmksa_add_preauth(hapd->wpa_auth, key, len,
sta->addr,
dot11RSNAConfigPMKLifetime,
sta->eapol_sm) == 0) {
hostapd_logger(hapd, sta->addr, HOSTAPD_MODULE_WPA,
HOSTAPD_LEVEL_DEBUG,
"added PMKSA cache entry (pre-auth)");
} else {
hostapd_logger(hapd, sta->addr, HOSTAPD_MODULE_WPA,
HOSTAPD_LEVEL_DEBUG,
"failed to add PMKSA cache entry "
"(pre-auth)");
}
}
/*
* Finish STA entry removal from timeout in order to avoid freeing
* STA data before the caller has finished processing.
*/
eloop_register_timeout(0, 0, rsn_preauth_finished_cb, hapd, sta);
}
void rsn_preauth_send(struct hostapd_data *hapd, struct sta_info *sta,
u8 *buf, size_t len)
{
struct rsn_preauth_interface *piface;
struct l2_ethhdr *ethhdr;
piface = hapd->preauth_iface;
while (piface) {
if (piface == sta->preauth_iface)
break;
piface = piface->next;
}
if (piface == NULL) {
wpa_printf(MSG_DEBUG, "RSN: Could not find pre-authentication "
"interface for " MACSTR, MAC2STR(sta->addr));
return;
}
ethhdr = os_malloc(sizeof(*ethhdr) + len);
if (ethhdr == NULL)
return;
os_memcpy(ethhdr->h_dest, sta->addr, ETH_ALEN);
os_memcpy(ethhdr->h_source, hapd->own_addr, ETH_ALEN);
2009-01-11 09:42:07 +01:00
ethhdr->h_proto = host_to_be16(ETH_P_PREAUTH);
os_memcpy(ethhdr + 1, buf, len);
if (l2_packet_send(piface->l2, sta->addr, ETH_P_PREAUTH, (u8 *) ethhdr,
sizeof(*ethhdr) + len) < 0) {
wpa_printf(MSG_ERROR, "Failed to send preauth packet using "
"l2_packet_send\n");
}
os_free(ethhdr);
}
void rsn_preauth_free_station(struct hostapd_data *hapd, struct sta_info *sta)
{
eloop_cancel_timeout(rsn_preauth_finished_cb, hapd, sta);
}
#endif /* CONFIG_RSN_PREAUTH */