struct fst_session * fst_session_create(struct fst_group *g)
{
struct fst_session *s;
u32 id;
WPA_ASSERT(!is_zero_ether_addr(own_addr));
id = fst_find_free_session_id();
if (id == FST_INVALID_SESSION_ID) {
fst_printf(MSG_ERROR, "Cannot assign new session ID");
return NULL;
}
s = os_zalloc(sizeof(*s));
if (!s) {
fst_printf(MSG_ERROR, "Cannot allocate new session object");
return NULL;
}
s->id = id;
s->group = g;
s->state = FST_SESSION_STATE_INITIAL;
s->data.llt_ms = FST_LLT_MS_DEFAULT;
fst_printf(MSG_INFO, "Session %u created", s->id);
dl_list_add_tail(&global_sessions_list, &s->global_sessions_lentry);
foreach_fst_ctrl_call(on_session_added, s);
return s;
}
void fst_session_delete(struct fst_session *s)
{
fst_printf(MSG_INFO, "Session %u deleted", s->id);
dl_list_del(&s->global_sessions_lentry);
foreach_fst_ctrl_call(on_session_removed, s);
os_free(s);
}
struct fst_iface * fst_attach(const char *ifname, const u8 *own_addr,
const struct fst_wpa_obj *iface_obj,
const struct fst_iface_cfg *cfg)
{
struct fst_group *g;
struct fst_group *group = NULL;
struct fst_iface *iface = NULL;
Boolean new_group = FALSE;
WPA_ASSERT(ifname != NULL);
WPA_ASSERT(iface_obj != NULL);
WPA_ASSERT(cfg != NULL);
foreach_fst_group(g) {
if (os_strcmp(cfg->group_id, fst_group_get_id(g)) == 0) {
group = g;
break;
}
}
if (!group) {
group = fst_group_create(cfg->group_id);
if (!group) {
fst_printf(MSG_ERROR, "%s: FST group cannot be created",
cfg->group_id);
return NULL;
}
new_group = TRUE;
}
iface = fst_iface_create(group, ifname, own_addr, iface_obj, cfg);
if (!iface) {
fst_printf_group(group, MSG_ERROR, "cannot create iface for %s",
ifname);
if (new_group)
fst_group_delete(group);
return NULL;
}
fst_group_attach_iface(group, iface);
fst_group_update_ie(group);
foreach_fst_ctrl_call(on_iface_added, iface);
fst_printf_iface(iface, MSG_DEBUG,
"iface attached to group %s (prio=%d, llt=%d)",
cfg->group_id, cfg->priority, cfg->llt);
return iface;
}
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);
}