hostap/src/ap/wnm_ap.c
Jouni Malinen 2049a875bc WNM: Additional BSS Transition Management capability
Add some more functionality for BSS Transition Management:
- advertise support for BSS Transition Management in extended
  capabilities element
- add hostapd.conf parameter bss_transition=1 for enabling support
  for BSS Transition Management
- add "hostapd_cli disassoc_imminent <STA> <num TBTTs>" for sending
  disassociation imminent notifications for testing purposes
- wpa_supplicant: trigger a new scan to find another BSS if the
  current AP indicates disassociation imminent (TODO: the old AP needs
  to be marked to use lower priority to avoid re-selecting it)

Signed-hostap: Jouni Malinen <j@w1.fi>
2012-12-22 20:27:30 +02:00

271 lines
7.8 KiB
C

/*
* hostapd - WNM
* Copyright (c) 2011-2012, Qualcomm Atheros, Inc.
*
* This software may be distributed under the terms of the BSD license.
* See README for more details.
*/
#include "utils/includes.h"
#include "utils/common.h"
#include "common/ieee802_11_defs.h"
#include "ap/hostapd.h"
#include "ap/sta_info.h"
#include "ap/ap_config.h"
#include "ap/ap_drv_ops.h"
#include "ap/wpa_auth.h"
#include "wnm_ap.h"
#define MAX_TFS_IE_LEN 1024
/* get the TFS IE from driver */
static int ieee80211_11_get_tfs_ie(struct hostapd_data *hapd, const u8 *addr,
u8 *buf, u16 *buf_len, enum wnm_oper oper)
{
wpa_printf(MSG_DEBUG, "%s: TFS get operation %d", __func__, oper);
return hostapd_drv_wnm_oper(hapd, oper, addr, buf, buf_len);
}
/* set the TFS IE to driver */
static int ieee80211_11_set_tfs_ie(struct hostapd_data *hapd, const u8 *addr,
u8 *buf, u16 *buf_len, enum wnm_oper oper)
{
wpa_printf(MSG_DEBUG, "%s: TFS set operation %d", __func__, oper);
return hostapd_drv_wnm_oper(hapd, oper, addr, buf, buf_len);
}
/* MLME-SLEEPMODE.response */
static int ieee802_11_send_wnmsleep_resp(struct hostapd_data *hapd,
const u8 *addr, u8 dialog_token,
u8 action_type, u16 intval)
{
struct ieee80211_mgmt *mgmt;
int res;
size_t len;
size_t gtk_elem_len = 0;
size_t igtk_elem_len = 0;
struct wnm_sleep_element wnmsleep_ie;
u8 *wnmtfs_ie;
u8 wnmsleep_ie_len;
u16 wnmtfs_ie_len;
u8 *pos;
struct sta_info *sta;
enum wnm_oper tfs_oper = action_type == WNM_SLEEP_MODE_ENTER ?
WNM_SLEEP_TFS_RESP_IE_ADD : WNM_SLEEP_TFS_RESP_IE_NONE;
sta = ap_get_sta(hapd, addr);
if (sta == NULL) {
wpa_printf(MSG_DEBUG, "%s: station not found", __func__);
return -EINVAL;
}
/* WNM-Sleep Mode IE */
os_memset(&wnmsleep_ie, 0, sizeof(struct wnm_sleep_element));
wnmsleep_ie_len = sizeof(struct wnm_sleep_element);
wnmsleep_ie.eid = WLAN_EID_WNMSLEEP;
wnmsleep_ie.len = wnmsleep_ie_len - 2;
wnmsleep_ie.action_type = action_type;
wnmsleep_ie.status = WNM_STATUS_SLEEP_ACCEPT;
wnmsleep_ie.intval = intval;
/* TFS IE(s) */
wnmtfs_ie = os_zalloc(MAX_TFS_IE_LEN);
if (wnmtfs_ie == NULL)
return -1;
if (ieee80211_11_get_tfs_ie(hapd, addr, wnmtfs_ie, &wnmtfs_ie_len,
tfs_oper)) {
wnmtfs_ie_len = 0;
os_free(wnmtfs_ie);
wnmtfs_ie = NULL;
}
#define MAX_GTK_SUBELEM_LEN 45
#define MAX_IGTK_SUBELEM_LEN 26
mgmt = os_zalloc(sizeof(*mgmt) + wnmsleep_ie_len +
MAX_GTK_SUBELEM_LEN + MAX_IGTK_SUBELEM_LEN);
if (mgmt == NULL) {
wpa_printf(MSG_DEBUG, "MLME: Failed to allocate buffer for "
"WNM-Sleep Response action frame");
return -1;
}
os_memcpy(mgmt->da, addr, ETH_ALEN);
os_memcpy(mgmt->sa, hapd->own_addr, ETH_ALEN);
os_memcpy(mgmt->bssid, hapd->own_addr, ETH_ALEN);
mgmt->frame_control = IEEE80211_FC(WLAN_FC_TYPE_MGMT,
WLAN_FC_STYPE_ACTION);
mgmt->u.action.category = WLAN_ACTION_WNM;
mgmt->u.action.u.wnm_sleep_resp.action = WNM_SLEEP_MODE_RESP;
mgmt->u.action.u.wnm_sleep_resp.dialogtoken = dialog_token;
pos = (u8 *)mgmt->u.action.u.wnm_sleep_resp.variable;
/* add key data if MFP is enabled */
if (!wpa_auth_uses_mfp(sta->wpa_sm) ||
action_type != WNM_SLEEP_MODE_EXIT) {
mgmt->u.action.u.wnm_sleep_resp.keydata_len = 0;
} else {
gtk_elem_len = wpa_wnmsleep_gtk_subelem(sta->wpa_sm, pos);
pos += gtk_elem_len;
wpa_printf(MSG_DEBUG, "Pass 4, gtk_len = %d",
(int) gtk_elem_len);
#ifdef CONFIG_IEEE80211W
res = wpa_wnmsleep_igtk_subelem(sta->wpa_sm, pos);
if (res < 0) {
os_free(wnmtfs_ie);
os_free(mgmt);
return -1;
}
igtk_elem_len = res;
pos += igtk_elem_len;
wpa_printf(MSG_DEBUG, "Pass 4 igtk_len = %d",
(int) igtk_elem_len);
#endif /* CONFIG_IEEE80211W */
WPA_PUT_LE16((u8 *)
&mgmt->u.action.u.wnm_sleep_resp.keydata_len,
gtk_elem_len + igtk_elem_len);
}
os_memcpy(pos, &wnmsleep_ie, wnmsleep_ie_len);
/* copy TFS IE here */
pos += wnmsleep_ie_len;
if (wnmtfs_ie)
os_memcpy(pos, wnmtfs_ie, wnmtfs_ie_len);
len = 1 + sizeof(mgmt->u.action.u.wnm_sleep_resp) + gtk_elem_len +
igtk_elem_len + wnmsleep_ie_len + wnmtfs_ie_len;
/* In driver, response frame should be forced to sent when STA is in
* PS mode */
res = hostapd_drv_send_action(hapd, hapd->iface->freq, 0,
mgmt->da, &mgmt->u.action.category, len);
if (!res) {
wpa_printf(MSG_DEBUG, "Successfully send WNM-Sleep Response "
"frame");
/* when entering wnmsleep
* 1. pause the node in driver
* 2. mark the node so that AP won't update GTK/IGTK during
* WNM Sleep
*/
if (wnmsleep_ie.status == WNM_STATUS_SLEEP_ACCEPT &&
wnmsleep_ie.action_type == WNM_SLEEP_MODE_ENTER) {
hostapd_drv_wnm_oper(hapd, WNM_SLEEP_ENTER_CONFIRM,
addr, NULL, NULL);
wpa_set_wnmsleep(sta->wpa_sm, 1);
}
/* when exiting wnmsleep
* 1. unmark the node
* 2. start GTK/IGTK update if MFP is not used
* 3. unpause the node in driver
*/
if ((wnmsleep_ie.status == WNM_STATUS_SLEEP_ACCEPT ||
wnmsleep_ie.status ==
WNM_STATUS_SLEEP_EXIT_ACCEPT_GTK_UPDATE) &&
wnmsleep_ie.action_type == WNM_SLEEP_MODE_EXIT) {
wpa_set_wnmsleep(sta->wpa_sm, 0);
hostapd_drv_wnm_oper(hapd, WNM_SLEEP_EXIT_CONFIRM,
addr, NULL, NULL);
if (!wpa_auth_uses_mfp(sta->wpa_sm))
wpa_wnmsleep_rekey_gtk(sta->wpa_sm);
}
} else
wpa_printf(MSG_DEBUG, "Fail to send WNM-Sleep Response frame");
#undef MAX_GTK_SUBELEM_LEN
#undef MAX_IGTK_SUBELEM_LEN
os_free(wnmtfs_ie);
os_free(mgmt);
return res;
}
static void ieee802_11_rx_wnmsleep_req(struct hostapd_data *hapd,
const u8 *addr, const u8 *frm, int len)
{
/* Dialog Token [1] | WNM-Sleep Mode IE | TFS Response IE */
const u8 *pos = frm;
u8 dialog_token;
struct wnm_sleep_element *wnmsleep_ie = NULL;
/* multiple TFS Req IE (assuming consecutive) */
u8 *tfsreq_ie_start = NULL;
u8 *tfsreq_ie_end = NULL;
u16 tfsreq_ie_len = 0;
dialog_token = *pos++;
while (pos + 1 < frm + len) {
u8 ie_len = pos[1];
if (pos + 2 + ie_len > frm + len)
break;
if (*pos == WLAN_EID_WNMSLEEP)
wnmsleep_ie = (struct wnm_sleep_element *) pos;
else if (*pos == WLAN_EID_TFS_REQ) {
if (!tfsreq_ie_start)
tfsreq_ie_start = (u8 *) pos;
tfsreq_ie_end = (u8 *) pos;
} else
wpa_printf(MSG_DEBUG, "WNM: EID %d not recognized",
*pos);
pos += ie_len + 2;
}
if (!wnmsleep_ie) {
wpa_printf(MSG_DEBUG, "No WNM-Sleep IE found");
return;
}
if (wnmsleep_ie->action_type == WNM_SLEEP_MODE_ENTER &&
tfsreq_ie_start && tfsreq_ie_end &&
tfsreq_ie_end - tfsreq_ie_start >= 0) {
tfsreq_ie_len = (tfsreq_ie_end + tfsreq_ie_end[1] + 2) -
tfsreq_ie_start;
wpa_printf(MSG_DEBUG, "TFS Req IE(s) found");
/* pass the TFS Req IE(s) to driver for processing */
if (ieee80211_11_set_tfs_ie(hapd, addr, tfsreq_ie_start,
&tfsreq_ie_len,
WNM_SLEEP_TFS_REQ_IE_SET))
wpa_printf(MSG_DEBUG, "Fail to set TFS Req IE");
}
ieee802_11_send_wnmsleep_resp(hapd, addr, dialog_token,
wnmsleep_ie->action_type,
wnmsleep_ie->intval);
if (wnmsleep_ie->action_type == WNM_SLEEP_MODE_EXIT) {
/* clear the tfs after sending the resp frame */
ieee80211_11_set_tfs_ie(hapd, addr, tfsreq_ie_start,
&tfsreq_ie_len, WNM_SLEEP_TFS_IE_DEL);
}
}
int ieee802_11_rx_wnm_action_ap(struct hostapd_data *hapd,
struct rx_action *action)
{
if (action->len < 1 || action->data == NULL)
return -1;
switch (action->data[0]) {
case WNM_BSS_TRANS_MGMT_QUERY:
wpa_printf(MSG_DEBUG, "WNM: BSS Transition Management Query");
/* TODO */
return -1;
case WNM_BSS_TRANS_MGMT_RESP:
wpa_printf(MSG_DEBUG, "WNM: BSS Transition Management "
"Response");
/* TODO */
return -1;
case WNM_SLEEP_MODE_REQ:
ieee802_11_rx_wnmsleep_req(hapd, action->sa, action->data + 1,
action->len - 1);
return 0;
}
wpa_printf(MSG_DEBUG, "WNM: Unsupported WNM Action %u from " MACSTR,
action->data[0], MAC2STR(action->sa));
return -1;
}