netdev: implement netdev_set_pmk

The 8021x offloading procedure still does EAP in userspace which
negotiates the PMK. The kernel then expects to obtain this PMK
from userspace by calling SET_PMK. This then allows the firmware
to begin the 4-way handshake.

Using __eapol_install_set_pmk_func to install netdev_set_pmk,
netdev now gets called into once EAP finishes and can begin
the final userspace actions prior to the firmware starting
the 4-way handshake:

 - SET_PMK using PMK negotiated with EAP
 - Emit SETTING_KEYS event
 - netdev_connect_ok

One thing to note is that the kernel provides no way of knowing if
the 4-way handshake completed. Assuming SET_PMK/SET_STATION come
back with no errors, IWD assumes the PMK was valid. If not, or
due to some other issue in the 4-way, the kernel will send a
disconnect.
This commit is contained in:
James Prestwood 2021-04-09 09:14:46 -07:00 committed by Denis Kenzior
parent 026ec40e1c
commit 379ec4b952
1 changed files with 55 additions and 0 deletions

View File

@ -83,6 +83,7 @@ struct netdev_handshake_state {
uint32_t group_new_key_cmd_id;
uint32_t group_management_new_key_cmd_id;
uint32_t set_station_cmd_id;
uint32_t set_pmk_cmd_id;
bool ptk_installed;
bool gtk_installed;
bool igtk_installed;
@ -252,6 +253,11 @@ static void netdev_handshake_state_cancel_all(
l_genl_family_cancel(nl80211, nhs->set_station_cmd_id);
nhs->set_station_cmd_id = 0;
}
if (nhs->set_pmk_cmd_id) {
l_genl_family_cancel(nl80211, nhs->set_pmk_cmd_id);
nhs->set_pmk_cmd_id = 0;
}
}
static void netdev_handshake_state_free(struct handshake_state *hs)
@ -1705,6 +1711,54 @@ invalid_key:
netdev_setting_keys_failed(nhs, err);
}
static void netdev_set_pmk_cb(struct l_genl_msg *msg, void *user_data)
{
struct netdev_handshake_state *nhs = user_data;
struct netdev *netdev = nhs->netdev;
int err = l_genl_msg_get_error(msg);
nhs->set_pmk_cmd_id = 0;
if (err < 0) {
l_error("Error with SET_PMK/SET_STATION");
netdev_setting_keys_failed(nhs, err);
return;
}
handshake_event(netdev->handshake, HANDSHAKE_EVENT_SETTING_KEYS);
netdev_connect_ok(netdev);
}
static void netdev_set_pmk(struct handshake_state *hs, const uint8_t *pmk,
size_t pmk_len)
{
struct l_genl_msg *msg;
struct netdev_handshake_state *nhs = l_container_of(hs,
struct netdev_handshake_state, super);
struct netdev *netdev = nhs->netdev;
/* Only relevent for 8021x offload */
if (nhs->type != CONNECTION_TYPE_8021X_OFFLOAD)
return;
msg = l_genl_msg_new(NL80211_CMD_SET_PMK);
l_genl_msg_append_attr(msg, NL80211_ATTR_IFINDEX, 4, &netdev->index);
l_genl_msg_append_attr(msg, NL80211_ATTR_MAC, 6, netdev->handshake->aa);
l_genl_msg_append_attr(msg, NL80211_ATTR_PMK,
netdev->handshake->pmk_len,
netdev->handshake->pmk);
nhs->set_pmk_cmd_id = l_genl_family_send(nl80211, msg,
netdev_set_pmk_cb,
nhs, NULL);
if (!nhs->set_pmk_cmd_id) {
l_error("Failed to set SET_PMK");
netdev_setting_keys_failed(nhs, -EIO);
return;
}
}
void netdev_handshake_failed(struct handshake_state *hs, uint16_t reason_code)
{
struct netdev_handshake_state *nhs =
@ -5566,6 +5620,7 @@ static int netdev_init(void)
__eapol_set_rekey_offload_func(netdev_set_rekey_offload);
__eapol_set_tx_packet_func(netdev_control_port_frame);
__eapol_set_install_pmk_func(netdev_set_pmk);
unicast_watch = l_genl_add_unicast_watch(genl, NL80211_GENL_NAME,
netdev_unicast_notify,