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f07119b33a
iwd/src/scan.c
Andrew Zaborowski 0d3f16ec5e scan: Call .destroy in scan_request_free 
The main difference with this is that scan_context removal will also
trigger the .destroy calls.  Normally there won't be any requests left
during scan_context but if there were any we should call destroy on
them.
2018-12-03 11:42:32 -06:00

1717 lines
38 KiB
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/*
*
* Wireless daemon for Linux
*
* Copyright (C) 2015-2018 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
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#define _GNU_SOURCE
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <time.h>
#include <sys/socket.h>
#include <limits.h>
#include <linux/if.h>
#include <linux/if_ether.h>
#include <ell/ell.h>
#include "linux/nl80211.h"
#include "src/iwd.h"
#include "src/wiphy.h"
#include "src/netdev.h"
#include "src/ie.h"
#include "src/common.h"
#include "src/network.h"
#include "src/knownnetworks.h"
#include "src/util.h"
#include "src/scan.h"
#define SCAN_MAX_INTERVAL 320
#define SCAN_INIT_INTERVAL 10
struct l_queue *scan_contexts = NULL;
static struct l_genl_family *nl80211 = NULL;
uint32_t scan_id = 0;
uint32_t next_scan_request_id = 0;
struct scan_periodic {
struct l_timeout *timeout;
uint16_t interval;
scan_trigger_func_t trigger;
scan_notify_func_t callback;
void *userdata;
bool rearm:1;
bool retry:1;
bool triggered:1;
bool needs_active_scan:1;
bool passive:1; /* Active or Passive scan? */
struct l_queue *cmds;
};
struct scan_request {
uint32_t id;
scan_trigger_func_t trigger;
scan_notify_func_t callback;
void *userdata;
scan_destroy_func_t destroy;
bool passive:1; /* Active or Passive scan? */
bool triggered:1;
struct l_queue *cmds;
};
struct scan_context {
uint32_t ifindex;
enum scan_state state;
struct scan_periodic sp;
struct l_queue *requests;
unsigned int start_cmd_id;
struct wiphy *wiphy;
};
struct scan_results {
uint32_t wiphy;
uint32_t ifindex;
struct l_queue *bss_list;
struct scan_freq_set *freqs;
};
static bool start_next_scan_request(struct scan_context *sc);
static void scan_periodic_rearm(struct scan_context *sc);
static bool scan_context_match(const void *a, const void *b)
{
const struct scan_context *sc = a;
uint32_t ifindex = L_PTR_TO_UINT(b);
return (sc->ifindex == ifindex);
}
static bool scan_request_match(const void *a, const void *b)
{
const struct scan_request *sr = a;
uint32_t id = L_PTR_TO_UINT(b);
return sr->id == id;
}
static void scan_request_free(void *data)
{
struct scan_request *sr = data;
if (sr->destroy)
sr->destroy(sr->userdata);
l_queue_destroy(sr->cmds, (l_queue_destroy_func_t) l_genl_msg_unref);
l_free(sr);
}
static void scan_request_trigger_failed(struct scan_request *sr, int err)
{
if (sr->trigger)
sr->trigger(err, sr->userdata);
scan_request_free(sr);
}
static struct scan_context *scan_context_new(uint32_t ifindex)
{
struct netdev *netdev = netdev_find(ifindex);
struct wiphy *wiphy;
struct scan_context *sc;
if (!netdev)
return NULL;
wiphy = netdev_get_wiphy(netdev);
if (!wiphy)
return NULL;
sc = l_new(struct scan_context, 1);
sc->ifindex = ifindex;
sc->wiphy = wiphy;
sc->state = SCAN_STATE_NOT_RUNNING;
sc->requests = l_queue_new();
return sc;
}
static void scan_context_free(struct scan_context *sc)
{
l_debug("sc: %p", sc);
l_queue_destroy(sc->sp.cmds, (l_queue_destroy_func_t) l_genl_msg_unref);
l_queue_destroy(sc->requests, scan_request_free);
if (sc->sp.timeout)
l_timeout_remove(sc->sp.timeout);
l_free(sc);
}
bool scan_ifindex_add(uint32_t ifindex)
{
struct scan_context *sc;
sc = l_queue_find(scan_contexts, scan_context_match,
L_UINT_TO_PTR(ifindex));
if (sc)
return false;
sc = scan_context_new(ifindex);
if (!sc)
return false;
l_queue_push_head(scan_contexts, sc);
return true;
}
bool scan_ifindex_remove(uint32_t ifindex)
{
struct scan_context *sc;
sc = l_queue_remove_if(scan_contexts, scan_context_match,
L_UINT_TO_PTR(ifindex));
if (!sc)
return false;
if (sc->start_cmd_id)
l_genl_family_cancel(nl80211, sc->start_cmd_id);
l_info("Removing scan context for ifindex: %u", ifindex);
scan_context_free(sc);
return true;
}
static unsigned int scan_send_start(struct l_genl_msg **msg,
scan_func_t callback, void *user_data)
{
unsigned int id = l_genl_family_send(nl80211, *msg, callback,
user_data, NULL);
if (id)
*msg = NULL;
else
l_error("Sending NL80211_CMD_TRIGGER_SCAN failed");
return id;
}
static void scan_triggered(struct l_genl_msg *msg, void *userdata)
{
struct scan_context *sc = userdata;
struct scan_request *sr = l_queue_peek_head(sc->requests);
int err;
l_debug("");
sc->start_cmd_id = 0;
err = l_genl_msg_get_error(msg);
if (err < 0) {
/* Scan in progress, defer */
if (err == -EBUSY)
return;
l_queue_pop_head(sc->requests);
scan_request_trigger_failed(sr, err);
l_error("Received error during CMD_TRIGGER_SCAN: %s (%d)",
strerror(-err), -err);
start_next_scan_request(sc);
return;
}
sc->state = sr->passive ? SCAN_STATE_PASSIVE : SCAN_STATE_ACTIVE;
l_debug("%s scan triggered for ifindex: %u",
sr->passive ? "Passive" : "Active", sc->ifindex);
sr->triggered = true;
if (sr->trigger) {
sr->trigger(0, sr->userdata);
/*
* Reset callback for the consequent scan triggerings of the
* multi-segmented scans.
*/
sr->trigger = NULL;
}
}
struct scan_freq_append_data {
struct l_genl_msg *msg;
int count;
};
static void scan_freq_append(uint32_t freq, void *user_data)
{
struct scan_freq_append_data *data = user_data;
l_genl_msg_append_attr(data->msg, data->count++, 4, &freq);
}
static void scan_build_attr_scan_frequencies(struct l_genl_msg *msg,
struct scan_freq_set *freqs)
{
struct scan_freq_append_data append_data = { msg, 0 };
l_genl_msg_enter_nested(msg, NL80211_ATTR_SCAN_FREQUENCIES);
scan_freq_set_foreach(freqs, scan_freq_append, &append_data);
l_genl_msg_leave_nested(msg);
}
static void scan_freq_count(uint32_t freq, void *user_data)
{
int *count = user_data;
*count += 1;
}
static struct l_genl_msg *scan_build_cmd(struct scan_context *sc,
bool ignore_flush_flag,
const struct scan_parameters *params)
{
struct l_genl_msg *msg;
int n_channels = 0;
uint32_t flags = 0;
if (params->freqs)
scan_freq_set_foreach(params->freqs, scan_freq_count,
&n_channels);
msg = l_genl_msg_new_sized(NL80211_CMD_TRIGGER_SCAN,
64 + params->extra_ie_size +
4 * n_channels);
l_genl_msg_append_attr(msg, NL80211_ATTR_IFINDEX, 4, &sc->ifindex);
if (params->extra_ie && params->extra_ie_size)
l_genl_msg_append_attr(msg, NL80211_ATTR_IE,
params->extra_ie_size,
params->extra_ie);
if (params->freqs)
scan_build_attr_scan_frequencies(msg, params->freqs);
if (params->flush && !ignore_flush_flag)
flags |= NL80211_SCAN_FLAG_FLUSH;
/*
* TODO: Discovery of the hidden networks with randomization flag set
* works with real hardware, but fails when used in simulated
* environment with mac80211_hwsim. This needs to be investigated.
*
* if (params->randomize_mac_addr_hint &&
* wiphy_has_feature(sc->wiphy,
* NL80211_FEATURE_SCAN_RANDOM_MAC_ADDR))
*
* Randomizing 46 bits (locally administered 1 and multicast 0
* is assumed).
*
* flags |= NL80211_SCAN_FLAG_RANDOM_ADDR;
*/
if (flags)
l_genl_msg_append_attr(msg, NL80211_ATTR_SCAN_FLAGS, 4, &flags);
return msg;
}
struct scan_cmds_add_data {
struct scan_context *sc;
const struct scan_parameters *params;
struct l_queue *cmds;
struct l_genl_msg **cmd;
uint8_t max_ssids_per_scan;
uint8_t num_ssids_can_append;
};
static bool scan_cmds_add_hidden(const struct network_info *network,
void *user_data)
{
struct scan_cmds_add_data *data = user_data;
if (!network->is_hidden)
return true;
l_genl_msg_append_attr(*data->cmd, NL80211_ATTR_SSID,
strlen(network->ssid), network->ssid);
data->num_ssids_can_append--;
if (!data->num_ssids_can_append) {
l_genl_msg_leave_nested(*data->cmd);
l_queue_push_tail(data->cmds, *data->cmd);
data->num_ssids_can_append = data->max_ssids_per_scan;
/*
* Create a consecutive scan trigger in the batch of scans.
* The 'flush' flag is ignored, this allows to get the results
* of all scans in the batch after the last scan is finished.
*/
*data->cmd = scan_build_cmd(data->sc, true, data->params);
l_genl_msg_enter_nested(*data->cmd, NL80211_ATTR_SCAN_SSIDS);
}
return true;
}
static void scan_cmds_add(struct l_queue *cmds, struct scan_context *sc,
bool passive,
const struct scan_parameters *params)
{
struct l_genl_msg *cmd;
struct scan_cmds_add_data data = {
sc,
params,
cmds,
&cmd,
wiphy_get_max_num_ssids_per_scan(sc->wiphy),
};
cmd = scan_build_cmd(sc, false, params);
if (passive) {
/* passive scan */
l_queue_push_tail(cmds, cmd);
return;
}
l_genl_msg_enter_nested(cmd, NL80211_ATTR_SCAN_SSIDS);
if (params->ssid) {
/* direct probe request scan */
l_genl_msg_append_attr(cmd, NL80211_ATTR_SSID,
strlen(params->ssid), params->ssid);
l_genl_msg_leave_nested(cmd);
l_queue_push_tail(cmds, cmd);
return;
}
data.num_ssids_can_append = data.max_ssids_per_scan;
known_networks_foreach(scan_cmds_add_hidden, &data);
l_genl_msg_append_attr(cmd, NL80211_ATTR_SSID, 0, NULL);
l_genl_msg_leave_nested(cmd);
l_queue_push_tail(cmds, cmd);
}
static int scan_request_send_next(struct scan_context *sc,
struct scan_request *sr)
{
struct l_genl_msg *cmd = l_queue_pop_head(sr->cmds);
if (!cmd)
return -ENOMSG;
sc->start_cmd_id = scan_send_start(&cmd, scan_triggered, sc);
if (sc->start_cmd_id) {
sr->triggered = false;
return 0;
}
l_genl_msg_unref(cmd);
return -EIO;
}
static uint32_t scan_common(uint32_t ifindex, bool passive,
const struct scan_parameters *params,
scan_trigger_func_t trigger,
scan_notify_func_t notify, void *userdata,
scan_destroy_func_t destroy)
{
struct scan_context *sc;
struct scan_request *sr;
sc = l_queue_find(scan_contexts, scan_context_match,
L_UINT_TO_PTR(ifindex));
if (!sc)
return 0;
sr = l_new(struct scan_request, 1);
sr->trigger = trigger;
sr->callback = notify;
sr->userdata = userdata;
sr->destroy = destroy;
sr->passive = passive;
sr->id = ++next_scan_request_id;
sr->cmds = l_queue_new();
scan_cmds_add(sr->cmds, sc, passive, params);
if (l_queue_length(sc->requests) > 0)
goto done;
if (sc->state != SCAN_STATE_NOT_RUNNING || sc->start_cmd_id)
goto done;
if (!scan_request_send_next(sc, sr))
goto done;
scan_request_free(sr);
return 0;
done:
l_queue_push_tail(sc->requests, sr);
return sr->id;
}
uint32_t scan_passive(uint32_t ifindex, scan_trigger_func_t trigger,
scan_notify_func_t notify, void *userdata,
scan_destroy_func_t destroy)
{
struct scan_parameters params = {};
return scan_common(ifindex, true, &params, trigger, notify,
userdata, destroy);
}
uint32_t scan_active(uint32_t ifindex, uint8_t *extra_ie, size_t extra_ie_size,
scan_trigger_func_t trigger,
scan_notify_func_t notify, void *userdata,
scan_destroy_func_t destroy)
{
struct scan_parameters params = {};
params.extra_ie = extra_ie;
params.extra_ie_size = extra_ie_size;
return scan_common(ifindex, false, &params,
trigger, notify, userdata, destroy);
}
uint32_t scan_active_full(uint32_t ifindex,
const struct scan_parameters *params,
scan_trigger_func_t trigger, scan_notify_func_t notify,
void *userdata, scan_destroy_func_t destroy)
{
return scan_common(ifindex, false, params,
trigger, notify, userdata, destroy);
}
bool scan_cancel(uint32_t ifindex, uint32_t id)
{
struct scan_context *sc;
struct scan_request *sr;
sc = l_queue_find(scan_contexts, scan_context_match,
L_UINT_TO_PTR(ifindex));
if (!sc)
return false;
sr = l_queue_peek_head(sc->requests);
if (!sr)
return false;
if (sr->id == id) {
/* If we already sent the trigger command, cancel the scan */
if (!sr->triggered && sc->start_cmd_id) {
l_genl_family_cancel(nl80211, sc->start_cmd_id);
sc->start_cmd_id = 0;
l_queue_pop_head(sc->requests);
start_next_scan_request(sc);
goto free;
}
/* If already triggered, just zero out the callback */
sr->callback = NULL;
if (sr->destroy) {
sr->destroy(sr->userdata);
sr->destroy = NULL;
}
return true;
}
sr = l_queue_remove_if(sc->requests, scan_request_match,
L_UINT_TO_PTR(id));
if (!sr)
return false;
free:
if (sr->destroy)
sr->destroy(sr->userdata);
scan_request_free(sr);
return true;
}
void scan_sched_start(struct l_genl_family *nl80211, uint32_t ifindex,
uint32_t scan_interval,
scan_func_t callback, void *user_data)
{
struct l_genl_msg *msg;
scan_interval *= 1000; /* in kernel the interval is in msecs */
msg = l_genl_msg_new_sized(NL80211_CMD_START_SCHED_SCAN, 32);
l_genl_msg_append_attr(msg, NL80211_ATTR_IFINDEX, 4, &ifindex);
l_genl_msg_append_attr(msg, NL80211_ATTR_SCHED_SCAN_INTERVAL,
4, &scan_interval);
l_genl_msg_append_attr(msg, NL80211_ATTR_SOCKET_OWNER, 0, NULL);
if (!l_genl_family_send(nl80211, msg, callback, user_data, NULL))
l_error("Starting scheduled scan failed");
}
static void scan_periodic_triggered(struct l_genl_msg *msg, void *user_data)
{
struct scan_context *sc = user_data;
int err;
l_debug("");
sc->sp.rearm = true;
sc->start_cmd_id = 0;
err = l_genl_msg_get_error(msg);
if (err < 0) {
/* Scan already in progress */
if (err != -EBUSY)
l_warn("Periodic scan could not be triggered: %s (%d)",
strerror(-err), -err);
if (!start_next_scan_request(sc))
scan_periodic_rearm(sc);
return;
}
sc->state = sc->sp.passive ? SCAN_STATE_PASSIVE : SCAN_STATE_ACTIVE;
l_debug("Periodic %s scan triggered for ifindex: %u", sc->sp.passive ?
"passive" : "active", sc->ifindex);
sc->sp.triggered = true;
if (sc->sp.trigger)
sc->sp.trigger(0, sc->sp.userdata);
}
static bool scan_periodic_send_start(struct scan_context *sc)
{
struct l_genl_msg *cmd;
struct scan_parameters params = {};
if (sc->sp.needs_active_scan && known_networks_has_hidden()) {
sc->sp.needs_active_scan = false;
sc->sp.passive = false;
params.randomize_mac_addr_hint = true;
} else {
sc->sp.passive = true;
}
scan_cmds_add(sc->sp.cmds, sc, sc->sp.passive, &params);
cmd = l_queue_pop_head(sc->sp.cmds);
if (!cmd)
return false;
sc->start_cmd_id = scan_send_start(&cmd, scan_periodic_triggered, sc);
if (!sc->start_cmd_id) {
l_genl_msg_unref(cmd);
return false;
}
return true;
}
static bool scan_periodic_is_disabled(void)
{
const struct l_settings *config = iwd_get_config();
bool disabled;
if (!l_settings_get_bool(config, "Scan", "disable_periodic_scan",
&disabled))
return false;
return disabled;
}
void scan_periodic_start(uint32_t ifindex, scan_trigger_func_t trigger,
scan_notify_func_t func, void *userdata)
{
struct scan_context *sc;
if (scan_periodic_is_disabled())
return;
sc = l_queue_find(scan_contexts, scan_context_match,
L_UINT_TO_PTR(ifindex));
if (!sc) {
l_error("scan_periodic_start called without scan_ifindex_add");
return;
}
if (sc->sp.interval)
return;
l_debug("Starting periodic scan for ifindex: %u", ifindex);
sc->sp.interval = SCAN_INIT_INTERVAL;
sc->sp.trigger = trigger;
sc->sp.callback = func;
sc->sp.userdata = userdata;
sc->sp.retry = true;
sc->sp.rearm = false;
sc->sp.cmds = l_queue_new();
start_next_scan_request(sc);
}
bool scan_periodic_stop(uint32_t ifindex)
{
struct scan_context *sc;
sc = l_queue_find(scan_contexts, scan_context_match,
L_UINT_TO_PTR(ifindex));
if (!sc)
return false;
if (!sc->sp.interval)
return false;
l_debug("Stopping periodic scan for ifindex: %u", ifindex);
if (sc->sp.timeout) {
l_timeout_remove(sc->sp.timeout);
sc->sp.timeout = NULL;
}
sc->sp.interval = 0;
sc->sp.trigger = NULL;
sc->sp.callback = NULL;
sc->sp.userdata = NULL;
sc->sp.rearm = false;
sc->sp.retry = false;
sc->sp.needs_active_scan = false;
l_queue_destroy(sc->sp.cmds, (l_queue_destroy_func_t) l_genl_msg_unref);
sc->sp.cmds = NULL;
return true;
}
static void scan_periodic_timeout(struct l_timeout *timeout, void *user_data)
{
struct scan_context *sc = user_data;
l_debug("scan_periodic_timeout: %u", sc->ifindex);
sc->sp.interval *= 2;
sc->sp.retry = true;
start_next_scan_request(sc);
}
static void scan_periodic_rearm(struct scan_context *sc)
{
l_debug("Arming periodic scan timer: %u", sc->sp.interval);
if (sc->sp.timeout)
l_timeout_modify(sc->sp.timeout, sc->sp.interval);
else
sc->sp.timeout = l_timeout_create(sc->sp.interval,
scan_periodic_timeout, sc, NULL);
sc->sp.rearm = false;
}
static bool start_next_scan_request(struct scan_context *sc)
{
struct scan_request *sr;
if (sc->state != SCAN_STATE_NOT_RUNNING || sc->start_cmd_id)
return true;
while (!l_queue_isempty(sc->requests)) {
sr = l_queue_peek_head(sc->requests);
if (!scan_request_send_next(sc, sr))
return true;
l_queue_pop_head(sc->requests);
scan_request_trigger_failed(sr, -EIO);
}
if (sc->sp.retry) {
if (scan_periodic_send_start(sc)) {
sc->sp.retry = false;
return true;
}
}
return false;
}
static bool scan_parse_bss_information_elements(struct scan_bss *bss,
const void *data, uint16_t len)
{
struct ie_tlv_iter iter;
bool have_ssid = false;
ie_tlv_iter_init(&iter, data, len);
while (ie_tlv_iter_next(&iter)) {
uint8_t tag = ie_tlv_iter_get_tag(&iter);
switch (tag) {
case IE_TYPE_SSID:
if (iter.len > 32)
return false;
memcpy(bss->ssid, iter.data, iter.len);
bss->ssid_len = iter.len;
have_ssid = true;
break;
case IE_TYPE_SUPPORTED_RATES:
case IE_TYPE_EXTENDED_SUPPORTED_RATES:
if (ie_parse_supported_rates(&iter,
&bss->supported_rates) < 0)
l_warn("Unable to parse [Extended] "
"Supported Rates IE for "
MAC, MAC_STR(bss->addr));
break;
case IE_TYPE_RSN:
if (!bss->rsne)
bss->rsne = l_memdup(iter.data - 2,
iter.len + 2);
break;
case IE_TYPE_BSS_LOAD:
if (ie_parse_bss_load(&iter, NULL, &bss->utilization,
NULL) < 0)
l_warn("Unable to parse BSS Load IE for "
MAC, MAC_STR(bss->addr));
else
l_debug("Load: %u/255", bss->utilization);
break;
case IE_TYPE_VENDOR_SPECIFIC:
/* Interested only in WPA IE from Vendor data */
if (!bss->wpa && is_ie_wpa_ie(iter.data, iter.len))
bss->wpa = l_memdup(iter.data - 2,
iter.len + 2);
break;
case IE_TYPE_MOBILITY_DOMAIN:
if (!bss->mde_present && iter.len == 3) {
memcpy(bss->mde, iter.data, iter.len);
bss->mde_present = true;
}
break;
case IE_TYPE_RM_ENABLED_CAPABILITIES:
if (iter.len != 5)
break;
/* Only interested in Neighbor Reports */
bss->cap_rm_neighbor_report =
(iter.data[0] & IE_RM_CAP_NEIGHBOR_REPORT) > 0;
break;
case IE_TYPE_COUNTRY:
if (bss->cc_present || iter.len < 6)
break;
bss->cc[0] = iter.data[0];
bss->cc[1] = iter.data[1];
bss->cc[2] = iter.data[2];
bss->cc_present = true;
break;
}
}
return have_ssid;
}
static struct scan_bss *scan_parse_attr_bss(struct l_genl_attr *attr)
{
uint16_t type, len;
const void *data;
struct scan_bss *bss;
bss = l_new(struct scan_bss, 1);
bss->utilization = 127;
while (l_genl_attr_next(attr, &type, &len, &data)) {
switch (type) {
case NL80211_BSS_BSSID:
if (len != sizeof(bss->addr))
goto fail;
memcpy(bss->addr, data, len);
break;
case NL80211_BSS_CAPABILITY:
if (len != sizeof(uint16_t))
goto fail;
bss->capability = *((uint16_t *) data);
break;
case NL80211_BSS_FREQUENCY:
if (len != sizeof(uint32_t))
goto fail;
bss->frequency = *((uint32_t *) data);
break;
case NL80211_BSS_SIGNAL_MBM:
if (len != sizeof(int32_t))
goto fail;
bss->signal_strength = *((int32_t *) data);
break;
case NL80211_BSS_INFORMATION_ELEMENTS:
if (!scan_parse_bss_information_elements(bss,
data, len))
goto fail;
bss->wsc = ie_tlv_extract_wsc_payload(data, len,
&bss->wsc_size);
break;
}
}
return bss;
fail:
scan_bss_free(bss);
return NULL;
}
static struct scan_freq_set *scan_parse_attr_scan_frequencies(
struct l_genl_attr *attr)
{
uint16_t type, len;
const void *data;
struct scan_freq_set *set;
set = scan_freq_set_new();
while (l_genl_attr_next(attr, &type, &len, &data)) {
uint32_t freq;
if (len != sizeof(uint32_t))
continue;
freq = *((uint32_t *) data);
scan_freq_set_add(set, freq);
}
return set;
}
static struct scan_bss *scan_parse_result(struct l_genl_msg *msg,
uint32_t *out_ifindex,
uint64_t *out_wdev)
{
struct l_genl_attr attr, nested;
uint16_t type, len;
const void *data;
uint32_t ifindex;
uint64_t wdev;
struct scan_bss *bss = NULL;
if (!l_genl_attr_init(&attr, msg))
return NULL;
while (l_genl_attr_next(&attr, &type, &len, &data)) {
switch (type) {
case NL80211_ATTR_IFINDEX:
if (len != sizeof(uint32_t))
return NULL;
ifindex = *((uint32_t *) data);
break;
case NL80211_ATTR_WDEV:
if (len != sizeof(uint64_t))
return NULL;
wdev = *((uint64_t *) data);
break;
case NL80211_ATTR_BSS:
if (!l_genl_attr_recurse(&attr, &nested))
return NULL;
bss = scan_parse_attr_bss(&nested);
break;
}
}
if (!bss)
return NULL;
if (out_ifindex)
*out_ifindex = ifindex;
if (out_wdev)
*out_wdev = wdev;
return bss;
}
static void scan_bss_compute_rank(struct scan_bss *bss)
{
static const double RANK_RSNE_FACTOR = 1.2;
static const double RANK_WPA_FACTOR = 1.0;
static const double RANK_OPEN_FACTOR = 0.5;
static const double RANK_NO_PRIVACY_FACTOR = 0.5;
static const double RANK_5G_FACTOR = 1.1;
static const double RANK_HIGH_UTILIZATION_FACTOR = 0.8;
static const double RANK_LOW_UTILIZATION_FACTOR = 1.2;
static const double RANK_MIN_SUPPORTED_RATE_FACTOR = 0.8;
static const double RANK_MAX_SUPPORTED_RATE_FACTOR = 1.1;
double rank;
uint32_t irank;
/*
* Signal strength is in mBm (100 * dBm) and is negative.
* WiFi range is -0 to -100 dBm
*/
/* Heavily slanted towards signal strength */
rank = 10000 + bss->signal_strength;
/*
* Prefer RSNE first, WPA second. Open networks are much less
* desirable.
*/
if (bss->rsne)
rank *= RANK_RSNE_FACTOR;
else if (bss->wpa)
rank *= RANK_WPA_FACTOR;
else
rank *= RANK_OPEN_FACTOR;
/* We prefer networks with CAP PRIVACY */
if (!(bss->capability & IE_BSS_CAP_PRIVACY))
rank *= RANK_NO_PRIVACY_FACTOR;
/* Prefer 5G networks over 2.4G */
if (bss->frequency > 4000)
rank *= RANK_5G_FACTOR;
/* Rank loaded APs lower and lighly loaded APs higher */
if (bss->utilization >= 192)
rank *= RANK_HIGH_UTILIZATION_FACTOR;
else if (bss->utilization <= 63)
rank *= RANK_LOW_UTILIZATION_FACTOR;
if (bss->supported_rates) {
uint8_t max = l_uintset_find_max(bss->supported_rates);
double factor = RANK_MAX_SUPPORTED_RATE_FACTOR -
RANK_MIN_SUPPORTED_RATE_FACTOR;
/*
* Maximum rate is 54 Mbps, see DATA_RATE in 802.11-2012,
* Section 6.5.5.2
*/
factor = factor * max / 108 + RANK_MIN_SUPPORTED_RATE_FACTOR;
rank *= factor;
}
irank = rank;
if (irank > USHRT_MAX)
bss->rank = USHRT_MAX;
else
bss->rank = irank;
}
void scan_bss_free(struct scan_bss *bss)
{
l_uintset_free(bss->supported_rates);
l_free(bss->rsne);
l_free(bss->wpa);
l_free(bss->wsc);
l_free(bss);
}
int scan_bss_get_rsn_info(const struct scan_bss *bss, struct ie_rsn_info *info)
{
/*
* If both an RSN and a WPA elements are present currently
* RSN takes priority and the WPA IE is ignored.
*/
if (bss->rsne) {
int res = ie_parse_rsne_from_data(bss->rsne, bss->rsne[1] + 2,
info);
if (res < 0) {
l_debug("Cannot parse RSN field (%d, %s)",
res, strerror(-res));
return res;
}
} else if (bss->wpa) {
int res = ie_parse_wpa_from_data(bss->wpa, bss->wpa[1] + 2,
info);
if (res < 0) {
l_debug("Cannot parse WPA IE (%d, %s)",
res, strerror(-res));
return res;
}
} else
return -ENOENT;
return 0;
}
int scan_bss_rank_compare(const void *a, const void *b, void *user_data)
{
const struct scan_bss *new_bss = a, *bss = b;
return bss->rank - new_bss->rank;
}
static void get_scan_callback(struct l_genl_msg *msg, void *user_data)
{
struct scan_results *results = user_data;
struct scan_bss *bss;
uint32_t ifindex;
l_debug("get_scan_callback");
if (!results->bss_list)
results->bss_list = l_queue_new();
bss = scan_parse_result(msg, &ifindex, NULL);
if (!bss)
return;
if (ifindex != results->ifindex) {
l_warn("ifindex mismatch in get_scan_callback");
scan_bss_free(bss);
return;
}
scan_bss_compute_rank(bss);
l_queue_insert(results->bss_list, bss, scan_bss_rank_compare, NULL);
}
static void discover_hidden_network_bsses(struct scan_context *sc,
struct l_queue *bss_list)
{
const struct l_queue_entry *bss_entry;
for (bss_entry = l_queue_get_entries(bss_list); bss_entry;
bss_entry = bss_entry->next) {
struct scan_bss *bss = bss_entry->data;
if (!util_ssid_is_hidden(bss->ssid_len, bss->ssid))
continue;
sc->sp.needs_active_scan = true;
}
}
static void scan_finished(struct scan_context *sc, uint32_t wiphy,
int err, struct l_queue *bss_list)
{
struct scan_request *sr;
scan_notify_func_t callback = NULL;
void *userdata;
scan_destroy_func_t destroy = NULL;
bool new_owner = false;
sr = l_queue_peek_head(sc->requests);
if (sr && sr->triggered) {
callback = sr->callback;
userdata = sr->userdata;
destroy = sr->destroy;
scan_request_free(sr);
l_queue_pop_head(sc->requests);
} else if (sc->sp.interval) {
/*
* If we'd called sc.sp->trigger, we must call back now
* independent of whether the scan was succesful or was
* aborted. If the scan was successful though we call back
* with the scan results even if didn't triggered this scan.
*/
if (sc->sp.triggered || bss_list) {
callback = sc->sp.callback;
userdata = sc->sp.userdata;
destroy = NULL;
}
sc->sp.triggered = false;
if (bss_list)
discover_hidden_network_bsses(sc, bss_list);
}
if (callback)
new_owner = callback(wiphy, sc->ifindex, err,
bss_list, userdata);
if (destroy)
destroy(userdata);
sc->state = SCAN_STATE_NOT_RUNNING;
if (!start_next_scan_request(sc) && sc->sp.rearm)
scan_periodic_rearm(sc);
if (bss_list && !new_owner)
l_queue_destroy(bss_list,
(l_queue_destroy_func_t) scan_bss_free);
}
static void get_scan_done(void *user)
{
struct scan_results *results = user;
struct scan_context *sc;
l_debug("get_scan_done");
sc = l_queue_find(scan_contexts, scan_context_match,
L_UINT_TO_PTR(results->ifindex));
if (sc)
scan_finished(sc, results->wiphy, 0, results->bss_list);
else
l_queue_destroy(results->bss_list,
(l_queue_destroy_func_t) scan_bss_free);
if (results->freqs)
scan_freq_set_free(results->freqs);
l_free(results);
}
static void scan_parse_new_scan_results(struct l_genl_msg *msg,
struct scan_results *results)
{
struct l_genl_attr attr, nested;
uint16_t type, len;
const void *data;
if (!l_genl_attr_init(&attr, msg))
return;
while (l_genl_attr_next(&attr, &type, &len, &data)) {
switch (type) {
case NL80211_ATTR_SCAN_FREQUENCIES:
if (!l_genl_attr_recurse(&attr, &nested)) {
l_warn("Failed to parse ATTR_SCAN_FREQUENCIES");
break;
}
results->freqs =
scan_parse_attr_scan_frequencies(&nested);
break;
}
}
}
static bool scan_send_next_cmd(struct scan_context *sc)
{
struct scan_request *sr = l_queue_peek_head(sc->requests);
int err;
if (sr && sr->triggered) {
err = scan_request_send_next(sc, sr);
if (!err)
return true;
/* Nothing left in the scan_request queue, we're done */
if (err < 0 && err == -ENOMSG)
return false;
sr = l_queue_pop_head(sc->requests);
scan_request_trigger_failed(sr, -EIO);
/*
* The request is destroyed, return 'true' to stop further
* processing.
*/
return true;
} else if (sc->sp.triggered) {
struct l_genl_msg *cmd = l_queue_pop_head(sc->sp.cmds);
if (!cmd)
return false;
sc->sp.triggered = false;
sc->start_cmd_id = scan_send_start(&cmd,
scan_periodic_triggered, sc);
if (!sc->start_cmd_id) {
l_genl_msg_unref(cmd);
l_queue_clear(sc->sp.cmds,
(l_queue_destroy_func_t) l_genl_msg_unref);
}
return true;
}
return false;
}
static void scan_notify(struct l_genl_msg *msg, void *user_data)
{
struct l_genl_attr attr;
uint16_t type, len;
const void *data;
uint8_t cmd;
uint32_t uninitialized_var(attr_ifindex);
bool have_ifindex;
uint32_t uninitialized_var(attr_wiphy);
bool have_wiphy;
struct scan_context *sc;
bool active_scan = false;
cmd = l_genl_msg_get_command(msg);
l_debug("Scan notification %u", cmd);
if (!l_genl_attr_init(&attr, msg))
return;
while (l_genl_attr_next(&attr, &type, &len, &data)) {
switch (type) {
case NL80211_ATTR_WIPHY:
if (len != sizeof(uint32_t)) {
l_warn("Invalid wiphy attribute");
return;
}
have_wiphy = true;
attr_wiphy = *((uint32_t *) data);
break;
case NL80211_ATTR_IFINDEX:
if (len != sizeof(uint32_t)) {
l_warn("Invalid interface index attribute");
return;
}
have_ifindex = true;
attr_ifindex = *((uint32_t *) data);
break;
case NL80211_ATTR_SCAN_SSIDS:
active_scan = true;
break;
}
}
if (!have_wiphy) {
l_warn("Scan results do not contain wiphy attribute");
return;
}
if (!have_ifindex) {
l_warn("Scan results do not contain ifindex attribute");
return;
}
sc = l_queue_find(scan_contexts, scan_context_match,
L_UINT_TO_PTR(attr_ifindex));
if (!sc)
return;
switch (cmd) {
case NL80211_CMD_NEW_SCAN_RESULTS:
case NL80211_CMD_SCHED_SCAN_RESULTS:
{
struct l_genl_msg *scan_msg;
struct scan_results *results;
if (scan_send_next_cmd(sc))
return;
results = l_new(struct scan_results, 1);
results->wiphy = attr_wiphy;
results->ifindex = attr_ifindex;
scan_parse_new_scan_results(msg, results);
scan_msg = l_genl_msg_new_sized(NL80211_CMD_GET_SCAN, 8);
l_genl_msg_append_attr(scan_msg, NL80211_ATTR_IFINDEX, 4,
&attr_ifindex);
l_genl_family_dump(nl80211, scan_msg, get_scan_callback,
results, get_scan_done);
break;
}
case NL80211_CMD_TRIGGER_SCAN:
if (active_scan)
sc->state = SCAN_STATE_ACTIVE;
else
sc->state = SCAN_STATE_PASSIVE;
break;
case NL80211_CMD_SCAN_ABORTED:
scan_finished(sc, attr_wiphy, -ECANCELED, NULL);
break;
}
}
uint8_t scan_freq_to_channel(uint32_t freq, enum scan_band *out_band)
{
uint32_t channel = 0;
if (freq >= 2412 && freq <= 2484) {
if (freq == 2484)
channel = 14;
else {
channel = freq - 2407;
if (channel % 5)
return 0;
channel /= 5;
}
if (out_band)
*out_band = SCAN_BAND_2_4_GHZ;
return channel;
}
if (freq >= 5005 && freq < 5900) {
if (channel % 5)
return 0;
channel = (freq - 5000) / 5;
if (out_band)
*out_band = SCAN_BAND_5_GHZ;
return channel;
}
if (freq >= 4905 && freq < 5000) {
if (channel % 5)
return 0;
channel = (freq - 4000) / 5;
if (out_band)
*out_band = SCAN_BAND_5_GHZ;
return channel;
}
return 0;
}
uint32_t scan_channel_to_freq(uint8_t channel, enum scan_band band)
{
if (band == SCAN_BAND_2_4_GHZ) {
if (channel >= 1 && channel <= 13)
return 2407 + 5 * channel;
if (channel == 14)
return 2484;
}
if (band == SCAN_BAND_5_GHZ) {
if (channel >= 1 && channel <= 179)
return 5000 + 5 * channel;
if (channel >= 181 && channel <= 199)
return 4000 + 5 * channel;
}
return 0;
}
static const char *const oper_class_us_codes[] = {
"US", "CA"
};
static const char *const oper_class_eu_codes[] = {
"AL", "AM", "AT", "AZ", "BA", "BE", "BG", "BY", "CH", "CY", "CZ", "DE",
"DK", "EE", "EL", "ES", "FI", "FR", "GE", "HR", "HU", "IE", "IS", "IT",
"LI", "LT", "LU", "LV", "MD", "ME", "MK", "MT", "NL", "NO", "PL", "PT",
"RO", "RS", "RU", "SE", "SI", "SK", "TR", "UA", "UK"
};
/* Annex E, table E-1 */
static const uint8_t oper_class_us_to_global[] = {
[1] = 115, [2] = 118, [3] = 124, [4] = 121,
[5] = 125, [6] = 103, [7] = 103, [8] = 102,
[9] = 102, [10] = 101, [11] = 101, [12] = 81,
[13] = 94, [14] = 95, [15] = 96, [22] = 116,
[23] = 119, [24] = 122, [25] = 126, [26] = 126,
[27] = 117, [28] = 120, [29] = 123, [30] = 127,
[31] = 127, [32] = 83, [33] = 84, [34] = 180,
/* 128 - 130 is a 1 to 1 mapping */
};
/* Annex E, table E-2 */
static const uint8_t oper_class_eu_to_global[] = {
[1] = 115, [2] = 118, [3] = 121, [4] = 81,
[5] = 116, [6] = 119, [7] = 122, [8] = 117,
[9] = 120, [10] = 123, [11] = 83, [12] = 84,
[17] = 125, [18] = 130,
/* 128 - 130 is a 1 to 1 mapping */
};
/* Annex E, table E-3 */
static const uint8_t oper_class_jp_to_global[] = {
[1] = 115, [2] = 112, [3] = 112, [4] = 112,
[5] = 112, [6] = 112, [7] = 109, [8] = 109,
[9] = 109, [10] = 109, [11] = 109, [12] = 113,
[13] = 113, [14] = 113, [15] = 113, [16] = 110,
[17] = 110, [18] = 110, [19] = 110, [20] = 110,
[21] = 114, [22] = 114, [23] = 114, [24] = 114,
[25] = 111, [26] = 111, [27] = 111, [28] = 111,
[29] = 111, [30] = 81, [31] = 82, [32] = 118,
[33] = 118, [34] = 121, [35] = 121, [36] = 116,
[37] = 119, [38] = 119, [39] = 122, [40] = 122,
[41] = 117, [42] = 120, [43] = 120, [44] = 123,
[45] = 123, [46] = 104, [47] = 104, [48] = 104,
[49] = 104, [50] = 104, [51] = 105, [52] = 105,
[53] = 105, [54] = 105, [55] = 105, [56] = 83,
[57] = 84, [58] = 121, [59] = 180,
/* 128 - 130 is a 1 to 1 mapping */
};
/* Annex E, table E-4 (only 2.4GHz and 4.9 / 5GHz bands) */
static const enum scan_band oper_class_to_band_global[] = {
[81 ... 84] = SCAN_BAND_2_4_GHZ,
[104 ... 130] = SCAN_BAND_5_GHZ,
};
/* Annex E, table E-5 */
static const uint8_t oper_class_cn_to_global[] = {
[1] = 115, [2] = 118, [3] = 125, [4] = 116,
[5] = 119, [6] = 126, [7] = 81, [8] = 83,
[9] = 84,
/* 128 - 130 is a 1 to 1 mapping */
};
enum scan_band scan_oper_class_to_band(const uint8_t *country,
uint8_t oper_class)
{
unsigned int i;
int table = 0;
if (country && country[2] >= 1 && country[2] <= 5)
table = country[2];
else if (country) {
for (i = 0; i < L_ARRAY_SIZE(oper_class_us_codes); i++)
if (!memcmp(oper_class_us_codes[i], country, 2)) {
/* Use table E-1 */
table = 1;
break;
}
for (i = 0; i < L_ARRAY_SIZE(oper_class_eu_codes); i++)
if (!memcmp(oper_class_eu_codes[i], country, 2)) {
/* Use table E-2 */
table = 2;
break;
}
if (!memcmp("JP", country, 2))
/* Use table E-3 */
table = 3;
if (!memcmp("CN", country, 2))
/* Use table E-5 */
table = 5;
}
switch (table) {
case 1:
if (oper_class < L_ARRAY_SIZE(oper_class_us_to_global))
oper_class = oper_class_us_to_global[oper_class];
break;
case 2:
if (oper_class < L_ARRAY_SIZE(oper_class_eu_to_global))
oper_class = oper_class_eu_to_global[oper_class];
break;
case 3:
if (oper_class < L_ARRAY_SIZE(oper_class_jp_to_global))
oper_class = oper_class_jp_to_global[oper_class];
break;
case 5:
if (oper_class < L_ARRAY_SIZE(oper_class_cn_to_global))
oper_class = oper_class_cn_to_global[oper_class];
break;
}
if (oper_class < L_ARRAY_SIZE(oper_class_to_band_global))
return oper_class_to_band_global[oper_class];
else
return 0;
}
struct scan_freq_set {
uint16_t channels_2ghz;
struct l_uintset *channels_5ghz;
};
struct scan_freq_set *scan_freq_set_new(void)
{
struct scan_freq_set *ret = l_new(struct scan_freq_set, 1);
/* 802.11-2012, 8.4.2.10 hints that 200 is the largest channel number */
ret->channels_5ghz = l_uintset_new_from_range(1, 200);
return ret;
}
void scan_freq_set_free(struct scan_freq_set *freqs)
{
l_uintset_free(freqs->channels_5ghz);
l_free(freqs);
}
bool scan_freq_set_add(struct scan_freq_set *freqs, uint32_t freq)
{
enum scan_band band;
uint8_t channel;
channel = scan_freq_to_channel(freq, &band);
if (!channel)
return false;
switch (band) {
case SCAN_BAND_2_4_GHZ:
freqs->channels_2ghz |= 1 << (channel - 1);
return true;
case SCAN_BAND_5_GHZ:
return l_uintset_put(freqs->channels_5ghz, channel);
}
return false;
}
bool scan_freq_set_contains(struct scan_freq_set *freqs, uint32_t freq)
{
enum scan_band band;
uint8_t channel;
channel = scan_freq_to_channel(freq, &band);
if (!channel)
return false;
switch (band) {
case SCAN_BAND_2_4_GHZ:
return freqs->channels_2ghz & (1 << (channel - 1));
case SCAN_BAND_5_GHZ:
return l_uintset_contains(freqs->channels_5ghz, channel);
}
return false;
}
uint32_t scan_freq_set_get_bands(struct scan_freq_set *freqs)
{
uint32_t bands = 0;
uint32_t max;
if (freqs->channels_2ghz)
bands |= SCAN_BAND_2_4_GHZ;
max = l_uintset_get_max(freqs->channels_5ghz);
if (l_uintset_find_min(freqs->channels_5ghz) <= max)
bands |= SCAN_BAND_5_GHZ;
return bands;
}
void scan_freq_set_foreach(struct scan_freq_set *freqs,
scan_freq_set_func_t func, void *user_data)
{
uint8_t channel;
uint32_t freq;
for (channel = 1; channel <= 14; channel++)
if (freqs->channels_2ghz & (1 << (channel - 1))) {
freq = scan_channel_to_freq(channel, SCAN_BAND_2_4_GHZ);
func(freq, user_data);
}
for (channel = 1; channel <= 200; channel++)
if (l_uintset_contains(freqs->channels_5ghz, channel)) {
freq = scan_channel_to_freq(channel, SCAN_BAND_5_GHZ);
func(freq, user_data);
}
}
bool scan_init(struct l_genl_family *in)
{
nl80211 = in;
scan_id = l_genl_family_register(nl80211, "scan", scan_notify,
NULL, NULL);
if (!scan_id) {
l_error("Registering for scan notification failed");
return false;
}
scan_contexts = l_queue_new();
return true;
}
bool scan_exit()
{
bool r;
l_debug("");
if (!nl80211)
return false;
l_queue_destroy(scan_contexts,
(l_queue_destroy_func_t) scan_context_free);
scan_contexts = NULL;
r = l_genl_family_unregister(nl80211, scan_id);
scan_id = 0;
nl80211 = 0;
return r;
}
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