int fst_session_initiate_switch(struct fst_session *s)
{
struct fst_ack_req req;
int res;
u8 dialog_token;
if (!fst_session_is_ready(s)) {
fst_printf_session(s, MSG_ERROR,
"cannot initiate switch due to wrong setup state (%d)",
s->state);
return -1;
}
dialog_token = fst_group_assign_dialog_token(s->group);
WPA_ASSERT(s->data.new_iface != NULL);
WPA_ASSERT(s->data.old_iface != NULL);
fst_printf_session(s, MSG_INFO, "initiating FST switch: %s => %s",
fst_iface_get_name(s->data.old_iface),
fst_iface_get_name(s->data.new_iface));
os_memset(&req, 0, sizeof(req));
req.action = FST_ACTION_ACK_REQUEST;
req.dialog_token = dialog_token;
req.fsts_id = host_to_le32(s->data.fsts_id);
res = fst_session_send_action(s, FALSE, &req, sizeof(req), NULL);
if (!res) {
fst_printf_sframe(s, FALSE, MSG_INFO, "FST Ack Request sent");
fst_session_set_state(s, FST_SESSION_STATE_TRANSITION_DONE,
NULL);
fst_session_stt_arm(s);
} else {
fst_printf_sframe(s, FALSE, MSG_ERROR,
"Cannot send FST Ack Request");
}
return res;
}
static void fst_ctrl_iface_notify_peer_state_change(struct fst_iface *iface,
Boolean connected,
const u8 *peer_addr)
{
union fst_event_extra extra;
extra.peer_state.connected = connected;
os_strlcpy(extra.peer_state.ifname, fst_iface_get_name(iface),
sizeof(extra.peer_state.ifname));
os_memcpy(extra.peer_state.addr, peer_addr, ETH_ALEN);
foreach_fst_ctrl_call(on_event, EVENT_PEER_STATE_CHANGED,
iface, NULL, &extra);
}
int fst_session_respond(struct fst_session *s, u8 status_code)
{
struct fst_setup_res res;
enum hostapd_hw_mode hw_mode;
u8 channel;
if (!fst_session_is_ready_pending(s)) {
fst_printf_session(s, MSG_ERROR, "incorrect state: %s",
fst_session_state_name(s->state));
return -EINVAL;
}
if (is_zero_ether_addr(s->data.old_peer_addr)) {
fst_printf_session(s, MSG_ERROR, "No peer MAC address");
return -EINVAL;
}
if (!s->data.old_iface) {
fst_printf_session(s, MSG_ERROR, "No old interface defined");
return -EINVAL;
}
if (!s->data.new_iface) {
fst_printf_session(s, MSG_ERROR, "No new interface defined");
return -EINVAL;
}
if (s->data.new_iface == s->data.old_iface) {
fst_printf_session(s, MSG_ERROR,
"Same interface set as old and new");
return -EINVAL;
}
if (!fst_iface_is_connected(s->data.old_iface,
s->data.old_peer_addr, FALSE)) {
fst_printf_session(s, MSG_ERROR,
"The preset peer address is not in the peer list");
return -EINVAL;
}
fst_session_stt_disarm(s);
os_memset(&res, 0, sizeof(res));
res.action = FST_ACTION_SETUP_RESPONSE;
res.dialog_token = s->data.pending_setup_req_dlgt;
res.status_code = status_code;
res.stie.element_id = WLAN_EID_SESSION_TRANSITION;
res.stie.length = sizeof(res.stie) - 2;
if (status_code == WLAN_STATUS_SUCCESS) {
res.stie.fsts_id = s->data.fsts_id;
res.stie.session_control = SESSION_CONTROL(SESSION_TYPE_BSS, 0);
fst_iface_get_channel_info(s->data.new_iface, &hw_mode,
&channel);
res.stie.new_band_id = fst_hw_mode_to_band(hw_mode);
res.stie.new_band_op = 1;
res.stie.new_band_setup = 0;
fst_iface_get_channel_info(s->data.old_iface, &hw_mode,
&channel);
res.stie.old_band_id = fst_hw_mode_to_band(hw_mode);
res.stie.old_band_op = 1;
res.stie.old_band_setup = 0;
fst_printf_session(s, MSG_INFO,
"%s: FST Setup Request accepted for %s (llt=%u)",
fst_iface_get_name(s->data.old_iface),
fst_iface_get_name(s->data.new_iface),
s->data.llt_ms);
} else {
fst_printf_session(s, MSG_WARNING,
"%s: FST Setup Request rejected with code %d",
fst_iface_get_name(s->data.old_iface),
status_code);
}
if (fst_session_send_action(s, TRUE, &res, sizeof(res),
fst_iface_get_mbie(s->data.old_iface))) {
fst_printf_sframe(s, TRUE, MSG_ERROR,
"cannot send FST Setup Response with code %d",
status_code);
return -EINVAL;
}
fst_printf_sframe(s, TRUE, MSG_INFO, "FST Setup Response sent");
if (status_code != WLAN_STATUS_SUCCESS) {
union fst_session_state_switch_extra evext = {
.to_initial = {
.reason = REASON_REJECT,
.reject_code = status_code,
.initiator = FST_INITIATOR_LOCAL,
},
};
fst_session_set_state(s, FST_SESSION_STATE_INITIAL, &evext);
}
return 0;
}
int fst_session_initiate_setup(struct fst_session *s)
{
struct fst_setup_req req;
int res;
u32 fsts_id;
u8 dialog_token;
struct fst_session *_s;
if (fst_session_is_in_progress(s)) {
fst_printf_session(s, MSG_ERROR, "Session in progress");
return -EINVAL;
}
if (is_zero_ether_addr(s->data.old_peer_addr)) {
fst_printf_session(s, MSG_ERROR, "No old peer MAC address");
return -EINVAL;
}
if (is_zero_ether_addr(s->data.new_peer_addr)) {
fst_printf_session(s, MSG_ERROR, "No new peer MAC address");
return -EINVAL;
}
if (!s->data.old_iface) {
fst_printf_session(s, MSG_ERROR, "No old interface defined");
return -EINVAL;
}
if (!s->data.new_iface) {
fst_printf_session(s, MSG_ERROR, "No new interface defined");
return -EINVAL;
}
if (s->data.new_iface == s->data.old_iface) {
fst_printf_session(s, MSG_ERROR,
"Same interface set as old and new");
return -EINVAL;
}
if (!fst_iface_is_connected(s->data.old_iface, s->data.old_peer_addr,
FALSE)) {
fst_printf_session(s, MSG_ERROR,
"The preset old peer address is not connected");
return -EINVAL;
}
if (!fst_iface_is_connected(s->data.new_iface, s->data.new_peer_addr,
FALSE)) {
fst_printf_session(s, MSG_ERROR,
"The preset new peer address is not connected");
return -EINVAL;
}
_s = fst_find_session_in_progress(s->data.old_peer_addr, s->group);
if (_s) {
fst_printf_session(s, MSG_ERROR,
"There is another session in progress (old): %u",
_s->id);
return -EINVAL;
}
_s = fst_find_session_in_progress(s->data.new_peer_addr, s->group);
if (_s) {
fst_printf_session(s, MSG_ERROR,
"There is another session in progress (new): %u",
_s->id);
return -EINVAL;
}
dialog_token = fst_group_assign_dialog_token(s->group);
fsts_id = fst_group_assign_fsts_id(s->group);
os_memset(&req, 0, sizeof(req));
fst_printf_siface(s, s->data.old_iface, MSG_INFO,
"initiating FST setup for %s (llt=%u ms)",
fst_iface_get_name(s->data.new_iface), s->data.llt_ms);
req.action = FST_ACTION_SETUP_REQUEST;
req.dialog_token = dialog_token;
req.llt = host_to_le32(FST_LLT_MS_TO_VAL(s->data.llt_ms));
/* 8.4.2.147 Session Transition element */
req.stie.element_id = WLAN_EID_SESSION_TRANSITION;
req.stie.length = sizeof(req.stie) - 2;
req.stie.fsts_id = host_to_le32(fsts_id);
req.stie.session_control = SESSION_CONTROL(SESSION_TYPE_BSS, 0);
req.stie.new_band_id = fst_iface_get_band_id(s->data.new_iface);
req.stie.new_band_op = 1;
req.stie.new_band_setup = 0;
req.stie.old_band_id = fst_iface_get_band_id(s->data.old_iface);
req.stie.old_band_op = 1;
req.stie.old_band_setup = 0;
res = fst_session_send_action(s, TRUE, &req, sizeof(req),
fst_iface_get_mbie(s->data.old_iface));
if (!res) {
s->data.fsts_id = fsts_id;
s->data.pending_setup_req_dlgt = dialog_token;
fst_printf_sframe(s, TRUE, MSG_INFO, "FST Setup Request sent");
fst_session_set_state(s, FST_SESSION_STATE_SETUP_COMPLETION,
NULL);
fst_session_stt_arm(s);
}
return res;
}
static void fst_session_handle_setup_response(struct fst_session *s,
struct fst_iface *iface,
const struct ieee80211_mgmt *mgmt,
size_t frame_len)
{
const struct fst_setup_res *res;
size_t plen = frame_len - IEEE80211_HDRLEN - 1;
enum hostapd_hw_mode hw_mode;
u8 channel;
union fst_session_state_switch_extra evext = {
.to_initial = {0},
};
if (iface != s->data.old_iface) {
fst_printf_session(s, MSG_WARNING,
"FST Response dropped: %s is not the old iface",
fst_iface_get_name(iface));
return;
}
if (!fst_session_is_ready_pending(s)) {
fst_printf_session(s, MSG_WARNING,
"FST Response dropped due to wrong state: %s",
fst_session_state_name(s->state));
return;
}
if (plen < sizeof(*res)) {
fst_printf_session(s, MSG_WARNING,
"Too short FST Response dropped");
return;
}
res = (const struct fst_setup_res *)
(((const u8 *) mgmt) + IEEE80211_HDRLEN + 1);
if (res->stie.element_id != WLAN_EID_SESSION_TRANSITION ||
res->stie.length < 11) {
fst_printf_iface(iface, MSG_WARNING,
"FST Response dropped: invalid STIE");
return;
}
if (res->dialog_token != s->data.pending_setup_req_dlgt) {
fst_printf_session(s, MSG_WARNING,
"FST Response dropped due to wrong dialog token (%u != %u)",
s->data.pending_setup_req_dlgt,
res->dialog_token);
return;
}
if (res->status_code == WLAN_STATUS_SUCCESS &&
le_to_host32(res->stie.fsts_id) != s->data.fsts_id) {
fst_printf_session(s, MSG_WARNING,
"FST Response dropped due to wrong FST Session ID (%u)",
le_to_host32(res->stie.fsts_id));
return;
}
fst_session_stt_disarm(s);
if (res->status_code != WLAN_STATUS_SUCCESS) {
/*
* 10.32.2.2 Transitioning between states
* The initiator shall set the STT to the value of the
* FSTSessionTimeOut field at ... and at each ACK frame sent in
* response to a received FST Setup Response with the Status
* Code field equal to PENDING_ADMITTING_FST_SESSION or
* PENDING_GAP_IN_BA_WINDOW.
*/
evext.to_initial.reason = REASON_REJECT;
evext.to_initial.reject_code = res->status_code;
evext.to_initial.initiator = FST_INITIATOR_REMOTE;
fst_session_set_state(s, FST_SESSION_STATE_INITIAL, &evext);
fst_printf_session(s, MSG_WARNING,
"FST Setup rejected by remote side with status %u",
res->status_code);
return;
}
fst_iface_get_channel_info(s->data.new_iface, &hw_mode, &channel);
if (fst_hw_mode_to_band(hw_mode) != res->stie.new_band_id) {
evext.to_initial.reason = REASON_ERROR_PARAMS;
fst_session_set_state(s, FST_SESSION_STATE_INITIAL, &evext);
fst_printf_session(s, MSG_WARNING,
"invalid FST Setup parameters");
fst_session_tear_down_setup(s);
return;
}
fst_printf_session(s, MSG_INFO,
"%s: FST Setup established for %s (llt=%u)",
fst_iface_get_name(s->data.old_iface),
fst_iface_get_name(s->data.new_iface),
s->data.llt_ms);
fst_session_notify_ctrl(s, EVENT_FST_ESTABLISHED, NULL);
if (s->data.llt_ms == FST_LLT_SWITCH_IMMEDIATELY)
fst_session_initiate_switch(s);
}
static void fst_session_handle_setup_request(struct fst_iface *iface,
const struct ieee80211_mgmt *mgmt,
size_t frame_len)
{
struct fst_session *s;
const struct fst_setup_req *req;
struct fst_iface *new_iface = NULL;
struct fst_group *g;
u8 new_iface_peer_addr[ETH_ALEN];
const struct wpabuf *peer_mbies;
size_t plen;
if (frame_len < IEEE80211_HDRLEN + 1 + sizeof(*req)) {
fst_printf_iface(iface, MSG_WARNING,
"FST Request dropped: too short (%zu < %zu)",
frame_len,
IEEE80211_HDRLEN + 1 + sizeof(*req));
return;
}
plen = frame_len - IEEE80211_HDRLEN - 1;
req = (const struct fst_setup_req *)
(((const u8 *) mgmt) + IEEE80211_HDRLEN + 1);
if (req->stie.element_id != WLAN_EID_SESSION_TRANSITION ||
req->stie.length < 11) {
fst_printf_iface(iface, MSG_WARNING,
"FST Request dropped: invalid STIE");
return;
}
if (req->stie.new_band_id == req->stie.old_band_id) {
fst_printf_iface(iface, MSG_WARNING,
"FST Request dropped: new and old band IDs are the same");
return;
}
g = fst_iface_get_group(iface);
if (plen > sizeof(*req)) {
fst_iface_update_mb_ie(iface, mgmt->sa, (const u8 *) (req + 1),
plen - sizeof(*req));
fst_printf_iface(iface, MSG_INFO,
"FST Request: MB IEs updated for " MACSTR,
MAC2STR(mgmt->sa));
}
peer_mbies = fst_iface_get_peer_mb_ie(iface, mgmt->sa);
if (peer_mbies) {
new_iface = fst_group_get_new_iface_by_stie_and_mbie(
g, wpabuf_head(peer_mbies), wpabuf_len(peer_mbies),
&req->stie, new_iface_peer_addr);
if (new_iface)
fst_printf_iface(iface, MSG_INFO,
"FST Request: new iface (%s:" MACSTR
") found by MB IEs",
fst_iface_get_name(new_iface),
MAC2STR(new_iface_peer_addr));
}
if (!new_iface) {
new_iface = fst_group_find_new_iface_by_stie(
g, iface, mgmt->sa, &req->stie,
new_iface_peer_addr);
if (new_iface)
fst_printf_iface(iface, MSG_INFO,
"FST Request: new iface (%s:" MACSTR
") found by others",
fst_iface_get_name(new_iface),
MAC2STR(new_iface_peer_addr));
}
if (!new_iface) {
fst_printf_iface(iface, MSG_WARNING,
"FST Request dropped: new iface not found");
return;
}
s = fst_find_session_in_progress(mgmt->sa, g);
if (s) {
union fst_session_state_switch_extra evext = {
.to_initial = {
.reason = REASON_SETUP,
},
};
/*
* 10.32.2.2 Transitioning between states:
* Upon receipt of an FST Setup Request frame, the responder
* shall respond with an FST Setup Response frame unless it has
* a pending FST Setup Request frame addressed to the initiator
* and the responder has a numerically larger MAC address than
* the initiator’s MAC address, in which case, the responder
* shall delete the received FST Setup Request.
*/
if (os_memcmp(mgmt->da, mgmt->sa, ETH_ALEN) > 0) {
fst_printf_session(s, MSG_WARNING,
"FST Request dropped due to MAC comparison (our MAC is "
MACSTR ")",
MAC2STR(mgmt->da));
return;
}
if (!fst_session_is_ready_pending(s)) {
fst_printf_session(s, MSG_WARNING,
"FST Request from " MACSTR
" dropped due to inappropriate state %s",
MAC2STR(mgmt->da),
fst_session_state_name(s->state));
return;
}
/*
* If FST Setup Request arrived with the same FSTS ID as one we
* initialized before, it means the other side either didn't
* receive our FST Request or skipped it for some reason (for
* example, due to numerical MAC comparison).
*
* In this case, there's no need to tear down the session.
* Moreover, as FSTS ID is the same, the other side will
* associate this tear down with the session it initiated that
* will break the sync.
*/
if (le_to_host32(req->stie.fsts_id) != s->data.fsts_id)
fst_session_send_tear_down(s);
else
fst_printf_session(s, MSG_WARNING,
"Skipping TearDown as the FST request has the same FSTS ID as initiated");
fst_session_set_state(s, FST_SESSION_STATE_INITIAL, &evext);
fst_session_stt_disarm(s);
fst_printf_session(s, MSG_WARNING, "reset due to FST request");
}
s = fst_session_create(g);
if (!s) {
fst_printf(MSG_WARNING,
"FST Request dropped: cannot create session for %s and %s",
fst_iface_get_name(iface),
fst_iface_get_name(new_iface));
return;
}
fst_session_set_iface(s, iface, TRUE);
fst_session_set_peer_addr(s, mgmt->sa, TRUE);
fst_session_set_iface(s, new_iface, FALSE);
fst_session_set_peer_addr(s, new_iface_peer_addr, FALSE);
fst_session_set_llt(s, FST_LLT_VAL_TO_MS(le_to_host32(req->llt)));
s->data.pending_setup_req_dlgt = req->dialog_token;
s->data.fsts_id = le_to_host32(req->stie.fsts_id);
fst_session_stt_arm(s);
fst_session_notify_ctrl(s, EVENT_FST_SETUP, NULL);
fst_session_set_state(s, FST_SESSION_STATE_SETUP_COMPLETION, NULL);
}
static void fst_session_handle_setup_request(struct fst_iface *iface,
const struct ieee80211_mgmt *mgmt,
size_t frame_len)
{
struct fst_session *s;
const struct fst_setup_req *req;
struct fst_iface *new_iface = NULL;
struct fst_group *g;
u8 new_iface_peer_addr[ETH_ALEN];
size_t plen;
if (frame_len < IEEE80211_HDRLEN + 1 + sizeof(*req)) {
fst_printf_iface(iface, MSG_WARNING,
"FST Request dropped: too short (%zu < %zu)",
frame_len,
IEEE80211_HDRLEN + 1 + sizeof(*req));
return;
}
plen = frame_len - IEEE80211_HDRLEN - 1;
req = (const struct fst_setup_req *)
(((const u8 *) mgmt) + IEEE80211_HDRLEN + 1);
if (req->stie.element_id != WLAN_EID_SESSION_TRANSITION ||
req->stie.length < 11) {
fst_printf_iface(iface, MSG_WARNING,
"FST Request dropped: invalid STIE");
return;
}
if (req->stie.new_band_id == req->stie.old_band_id) {
fst_printf_iface(iface, MSG_WARNING,
"FST Request dropped: new and old band IDs are the same");
return;
}
g = fst_iface_get_group(iface);
if (plen > sizeof(*req)) {
fst_iface_update_mb_ie(iface, mgmt->sa, (const u8 *) (req + 1),
plen - sizeof(*req));
fst_printf_iface(iface, MSG_INFO,
"FST Request: MB IEs updated for " MACSTR,
MAC2STR(mgmt->sa));
}
new_iface = fst_group_get_peer_other_connection(iface, mgmt->sa,
req->stie.new_band_id,
new_iface_peer_addr);
if (!new_iface) {
fst_printf_iface(iface, MSG_WARNING,
"FST Request dropped: new iface not found");
return;
}
fst_printf_iface(iface, MSG_INFO,
"FST Request: new iface (%s:" MACSTR ") found",
fst_iface_get_name(new_iface),
MAC2STR(new_iface_peer_addr));
s = fst_find_session_in_progress(mgmt->sa, g);
if (s) {
union fst_session_state_switch_extra evext = {
.to_initial = {
.reason = REASON_SETUP,
},
};
/*
* 10.32.2.2 Transitioning between states:
* Upon receipt of an FST Setup Request frame, the responder
* shall respond with an FST Setup Response frame unless it has
* a pending FST Setup Request frame addressed to the initiator
* and the responder has a numerically larger MAC address than
* the initiator’s MAC address, in which case, the responder
* shall delete the received FST Setup Request.
*/
if (fst_session_is_ready_pending(s) &&
/* waiting for Setup Response */
os_memcmp(mgmt->da, mgmt->sa, ETH_ALEN) > 0) {
fst_printf_session(s, MSG_WARNING,
"FST Request dropped due to MAC comparison (our MAC is "
MACSTR ")",
MAC2STR(mgmt->da));
return;
}
/*
* State is SETUP_COMPLETION (either in transition or not) or
* TRANSITION_DONE (in transition).
* Setup Request arriving in this state could mean:
* 1. peer sent it before receiving our Setup Request (race
* condition)
* 2. peer didn't receive our Setup Response. Peer is retrying
* after STT timeout
* 3. peer's FST state machines are out of sync due to some
* other reason
*
* We will reset our session and create a new one instead.
*/
fst_printf_session(s, MSG_WARNING,
"resetting due to FST request");
/*
* If FST Setup Request arrived with the same FSTS ID as one we
* initialized before, there's no need to tear down the session.
* Moreover, as FSTS ID is the same, the other side will
* associate this tear down with the session it initiated that
* will break the sync.
*/
if (le_to_host32(req->stie.fsts_id) != s->data.fsts_id)
fst_session_send_tear_down(s);
else
fst_printf_session(s, MSG_WARNING,
"Skipping TearDown as the FST request has the same FSTS ID as initiated");
fst_session_set_state(s, FST_SESSION_STATE_INITIAL, &evext);
fst_session_stt_disarm(s);
}
s = fst_session_create(g);
if (!s) {
fst_printf(MSG_WARNING,
"FST Request dropped: cannot create session for %s and %s",
fst_iface_get_name(iface),
fst_iface_get_name(new_iface));
return;
}
fst_session_set_iface(s, iface, TRUE);
fst_session_set_peer_addr(s, mgmt->sa, TRUE);
fst_session_set_iface(s, new_iface, FALSE);
fst_session_set_peer_addr(s, new_iface_peer_addr, FALSE);
fst_session_set_llt(s, FST_LLT_VAL_TO_MS(le_to_host32(req->llt)));
s->data.pending_setup_req_dlgt = req->dialog_token;
s->data.fsts_id = le_to_host32(req->stie.fsts_id);
fst_session_stt_arm(s);
fst_session_notify_ctrl(s, EVENT_FST_SETUP, NULL);
fst_session_set_state(s, FST_SESSION_STATE_SETUP_COMPLETION, NULL);
}
