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mirror of https://git.kernel.org/pub/scm/network/wireless/iwd.git synced 2024-10-04 02:18:49 +02:00

device: Add support for AP directed roaming

This patch adds a watcher/parser for the frame event associated with
an AP directed BSS transition (AP roaming). When the AP sends a BSS
transition request, this will parse out the BSS candidate list
(neighbor report) and initiate a roam scan. After this point the
existing roaming code path is reused.
This commit is contained in:
James Prestwood 2018-01-18 13:36:38 -08:00 committed by Denis Kenzior
parent 6a9de526a8
commit 38e9a67da8

View File

@ -2,7 +2,7 @@
*
* Wireless daemon for Linux
*
* Copyright (C) 2013-2016 Intel Corporation. All rights reserved.
* Copyright (C) 2013-2018 Intel Corporation. All rights reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
@ -90,6 +90,9 @@ struct device {
bool preparing_roam : 1;
bool signal_low : 1;
bool roam_no_orig_ap : 1;
bool ap_directed_roaming : 1;
uint32_t ap_roam_watch;
};
struct signal_agent {
@ -763,6 +766,7 @@ static void device_roam_failed(struct device *device)
device->preparing_roam = false;
device->roam_no_orig_ap = false;
device->ap_directed_roaming = false;
if (device->state == DEVICE_STATE_ROAMING)
device_disassociated(device);
@ -921,6 +925,9 @@ static void device_transition_start(struct device *device, struct scan_bss *bss)
l_debug("%d, target %s", device->index,
util_address_to_string(bss->addr));
/* Reset AP roam flag, at this point the roaming behaves the same */
device->ap_directed_roaming = false;
if (hs->mde)
ie_parse_mobility_domain_from_data(hs->mde, hs->mde[1] + 2,
&mdid, NULL, NULL);
@ -1054,6 +1061,11 @@ static bool device_roam_scan_notify(uint32_t wiphy_id, uint32_t ifindex,
struct ie_rsn_info info;
int r;
/* Skip the BSS we are connected to if doing an AP roam */
if (device->ap_directed_roaming && !memcmp(bss->addr,
device->connected_bss->addr, 6))
goto next;
/* Skip result if it is not part of the ESS */
if (bss->ssid_len != hs->ssid_len ||
@ -1153,6 +1165,29 @@ static void device_roam_scan(struct device *device,
device_roam_failed(device);
}
static uint32_t device_freq_from_neighbor_report(const uint8_t *country,
struct ie_neighbor_report_info *info)
{
enum scan_band band;
uint32_t freq;
band = scan_oper_class_to_band(country, info->oper_class);
if (!band) {
l_debug("Ignored: unsupported oper class");
return 0;
}
freq = scan_channel_to_freq(info->channel_num, band);
if (!freq) {
l_debug("Ignored: unsupported channel");
return 0;
}
return freq;
}
static void device_neighbor_report_cb(struct netdev *netdev, int err,
const uint8_t *reports,
size_t reports_len, void *user_data)
@ -1186,7 +1221,6 @@ static void device_neighbor_report_cb(struct netdev *netdev, int err,
/* First see if any of the reports contain the MD bit set */
while (ie_tlv_iter_next(&iter)) {
struct ie_neighbor_report_info info;
enum scan_band band;
uint32_t freq;
const uint8_t *cc = NULL;
@ -1205,19 +1239,9 @@ static void device_neighbor_report_cb(struct netdev *netdev, int err,
if (device->connected_bss->cc_present)
cc = device->connected_bss->cc;
band = scan_oper_class_to_band(cc, info.oper_class);
if (!band) {
l_debug("Ignored: unsupported oper class");
freq = device_freq_from_neighbor_report(cc, &info);
if (!freq)
continue;
}
freq = scan_channel_to_freq(info.channel_num, band);
if (!freq) {
l_debug("Ignored: unsupported channel");
continue;
}
if (!memcmp(info.addr, device->connected_bss->addr, ETH_ALEN)) {
/*
@ -1333,6 +1357,91 @@ static void device_roam_timeout_rearm(struct device *device, int seconds)
l_timeout_create(seconds, device_roam_trigger_cb, device, NULL);
}
#define AP_ROAM_BSS_LIST_BIT (1 << 0)
#define AP_ROAM_BSS_TERMINATION_BIT (1 << 3)
#define AP_ROAM_ESS_DISSASSOCIATION_IMMINENT (1 << 4)
static void device_ap_roam_frame_event(struct netdev *netdev,
const struct mmpdu_header *hdr,
const void *body, size_t body_len,
void *user_data)
{
struct device *device = user_data;
uint32_t pos = 0;
uint8_t req_mode;
uint16_t dtimer;
uint8_t valid_interval;
if (device->preparing_roam || device->state == DEVICE_STATE_ROAMING)
return;
if (body_len < 7)
goto format_error;
/*
* First two bytes are checked by the frame watch (WNM category and
* WNM action). The third is the dialog token which is not relevant
* because we did not send a BSS transition query -- so skip these
* first three bytes.
*/
pos += 3;
req_mode = l_get_u8(body + pos);
pos++;
/*
* TODO: Disassociation timer and validity interval are currently not
* used since the BSS transition request is being handled immediately.
*/
dtimer = l_get_le16(body + pos);
pos += 2;
valid_interval = l_get_u8(body + pos);
pos++;
l_debug("BSS transition received from AP: Disassociation Time: %u, "
"Validity interval: %u", dtimer, valid_interval);
/* check req_mode for optional values */
if (req_mode & AP_ROAM_BSS_TERMINATION_BIT) {
if (pos + 12 > body_len)
goto format_error;
pos += 12;
}
if (req_mode & AP_ROAM_ESS_DISSASSOCIATION_IMMINENT) {
uint8_t url_len;
if (pos + 1 > body_len)
goto format_error;
url_len = l_get_u8(body + pos);
pos++;
if (pos + url_len > body_len)
goto format_error;
pos += url_len;
}
device->ap_directed_roaming = true;
device->preparing_roam = true;
l_timeout_remove(device->roam_trigger_timeout);
device->roam_trigger_timeout = NULL;
if (req_mode & AP_ROAM_BSS_LIST_BIT)
device_neighbor_report_cb(device->netdev, 0, body + pos,
body_len - pos, device);
else
device_roam_scan(device, NULL);
return;
format_error:
l_debug("bad AP roam frame formatting");
}
static void device_lost_beacon(struct device *device)
{
l_debug("%d", device->index);
@ -2216,6 +2325,7 @@ struct device *device_create(struct wiphy *wiphy, struct netdev *netdev)
struct device *device;
struct l_dbus *dbus = dbus_get_bus();
uint32_t ifindex = netdev_get_ifindex(netdev);
const uint8_t action_ap_roam_prefix[2] = { 0x0a, 0x07 };
device = l_new(struct device, 1);
device->bss_list = l_queue_new();
@ -2252,6 +2362,13 @@ struct device *device_create(struct wiphy *wiphy, struct netdev *netdev)
device->netdev_watch_id =
netdev_watch_add(netdev, device_netdev_notify, device);
/*
* register for AP roam transition watch
*/
device->ap_roam_watch = netdev_frame_watch_add(netdev, 0x00d0,
action_ap_roam_prefix, sizeof(action_ap_roam_prefix),
device_ap_roam_frame_event, device);
return device;
}
@ -2297,6 +2414,9 @@ static void device_free(void *user)
l_timeout_remove(device->roam_trigger_timeout);
scan_ifindex_remove(device->index);
netdev_frame_watch_remove(device->netdev, device->ap_roam_watch);
l_free(device);
}