/*
* This file contains the softmac's association logic.
*
* Copyright (c) 2005, 2006 Johannes Berg <johannes@sipsolutions.net>
* Joseph Jezak <josejx@gentoo.org>
* Larry Finger <Larry.Finger@lwfinger.net>
* Danny van Dyk <kugelfang@gentoo.org>
* Michael Buesch <mbuesch@freenet.de>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of version 2 of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program 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 General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* The full GNU General Public License is included in this distribution in the
* file called COPYING.
*/
#include "ieee80211softmac_priv.h"
/*
* Overview
*
* Before you can associate, you have to authenticate.
*
*/
/* Sends out an association request to the desired AP */
static void
ieee80211softmac_assoc(struct ieee80211softmac_device *mac, struct ieee80211softmac_network *net)
{
unsigned long flags;
/* Switch to correct channel for this network */
mac->set_channel(mac->dev, net->channel);
/* Send association request */
ieee80211softmac_send_mgt_frame(mac, net, IEEE80211_STYPE_ASSOC_REQ, 0);
dprintk(KERN_INFO PFX "sent association request!\n");
spin_lock_irqsave(&mac->lock, flags);
mac->associated = 0; /* just to make sure */
/* Set a timer for timeout */
/* FIXME: make timeout configurable */
if (likely(mac->running))
schedule_delayed_work(&mac->associnfo.timeout, 5 * HZ);
spin_unlock_irqrestore(&mac->lock, flags);
}
void
ieee80211softmac_assoc_timeout(void *d)
{
struct ieee80211softmac_device *mac = (struct ieee80211softmac_device *)d;
struct ieee80211softmac_network *n;
unsigned long flags;
spin_lock_irqsave(&mac->lock, flags);
/* we might race against ieee80211softmac_handle_assoc_response,
* so make sure only one of us does something */
if (!mac->associnfo.associating) {
spin_unlock_irqrestore(&mac->lock, flags);
return;
}
mac->associnfo.associating = 0;
mac->associnfo.bssvalid = 0;
mac->associated = 0;
n = ieee80211softmac_get_network_by_bssid_locked(mac, mac->associnfo.bssid);
spin_unlock_irqrestore(&mac->lock, flags);
dprintk(KERN_INFO PFX "assoc request timed out!\n");
ieee80211softmac_call_events(mac, IEEE80211SOFTMAC_EVENT_ASSOCIATE_TIMEOUT, n);
}
void
ieee80211softmac_disassoc(struct ieee80211softmac_device *mac)
{
unsigned long flags;
spin_lock_irqsave(&mac->lock, flags);
if (mac->associnfo.associating)
cancel_delayed_work(&mac->associnfo.timeout);
netif_carrier_off(mac->dev);
mac->associated = 0;
mac->associnfo.bssvalid = 0;
mac->associnfo.associating = 0;
ieee80211softmac_init_bss(mac);
ieee80211softmac_call_events_locked(mac, IEEE80211SOFTMAC_EVENT_DISASSOCIATED, NULL);
spin_unlock_irqrestore(&mac->lock, flags);
}
/* Sends out a disassociation request to the desired AP */
void
ieee80211softmac_send_disassoc_req(struct ieee80211softmac_device *mac, u16 reason)
{
struct ieee80211softmac_network *found;
if (mac->associnfo.bssvalid && mac->associated) {
found = ieee80211softmac_get_network_by_bssid(mac, mac->associnfo.bssid);
if (found)
ieee80211softmac_send_mgt_frame(mac, found, IEEE80211_STYPE_DISASSOC, reason);
}
ieee80211softmac_disassoc(mac);
}
static inline int
we_support_all_basic_rates(struct ieee80211softmac_device *mac, u8 *from, u8 from_len)
{
int idx;
u8 rate;
for (idx = 0; idx < (from_len); idx++) {
rate = (from)[idx];
if (!(rate & IEEE80211_BASIC_RATE_MASK))
continue;
rate &= ~IEEE80211_BASIC_RATE_MASK;
if (!ieee80211softmac_ratesinfo_rate_supported(&mac->ratesinfo, rate))
return 0;
}
return 1;
}
static int
network_matches_request(struct ieee80211softmac_device *mac, struct ieee80211_network *net)
{
/* we cannot associate to networks whose name we don't know */
if (ieee80211_is_empty_essid(net->ssid, net->ssid_len))
return 0;
/* do not associate to a network whose BSSBasicRateSet we cannot support */
if (!we_support_all_basic_rates(mac, net->rates, net->rates_len))
return 0;
/* do we really need to check the ex rates? */
if (!we_support_all_basic_rates(mac, net->rates_ex, net->rates_ex_len))
return 0;
/* assume that users know what they're doing ...
* (note we don't let them select a net we're incompatible with) */
if (mac->associnfo.bssfixed) {
return !memcmp(mac->associnfo.bssid, net->bssid, ETH_ALEN);
}
/* if 'ANY' network requested, take any that doesn't have privacy enabled */
if (mac->associnfo.req_essid.len == 0
&& !(net->capability & WLAN_CAPABILITY_PRIVACY))
return 1;
if (net->ssid_len != mac->associnfo.req_essid.len)
return 0;
if (!memcmp(net->ssid, mac->associnfo.req_essid.data, mac->associnfo.req_essid.len))
return 1;
return 0;
}
static void
ieee80211softmac_assoc_notify_scan(struct net_device *dev, int event_type, void *context)
{
struct ieee80211softmac_device *mac = ieee80211_priv(dev);
ieee80211softmac_assoc_work((void*)mac);
}
static void
ieee80211softmac_assoc_notify_auth(struct net_device *dev, int event_type, void *context)
{
struct ieee80211softmac_device *mac = ieee80211_priv(dev);
switch (event_type) {
case IEEE80211SOFTMAC_EVENT_AUTHENTICATED:
ieee80211softmac_assoc_work((void*)mac);
break;
case IEEE80211SOFTMAC_EVENT_AUTH_FAILED:
case IEEE80211SOFTMAC_EVENT_AUTH_TIMEOUT:
ieee80211softmac_disassoc(mac);
break;
}
}
/* This function is called to handle userspace requests (asynchronously) */
void
ieee80211softmac_assoc_work(void *d)
{
struct ieee80211softmac_device *mac = (struct ieee80211softmac_device *)d;
struct ieee80211softmac_network *found = NULL;
struct ieee80211_network *net = NULL, *best = NULL;
int bssvalid;
unsigned long flags;
/* ieee80211_disassoc might clear this */
bssvalid = mac->associnfo.bssvalid;
/* meh */
if (mac->associated)
ieee80211softmac_send_disassoc_req(mac, WLAN_REASON_DISASSOC_STA_HAS_LEFT);
spin_lock_irqsave(&mac->lock, flags);
mac->associnfo.associating = 1;
spin_unlock_irqrestore(&mac->lock, flags);
/* try to find the requested network in our list, if we found one already */
if (bssvalid || mac->associnfo.bssfixed)
found = ieee80211softmac_get_network_by_bssid(mac, mac->associnfo.bssid);
/* Search the ieee80211 networks for this network if we didn't find it by bssid,
* but only if we've scanned at least once (to get a better list of networks to
* select from). If we have not scanned before, the !found logic below will be
* invoked and will scan. */
if (!found && (mac->associnfo.scan_retry < IEEE80211SOFTMAC_ASSOC_SCAN_RETRY_LIMIT))
{
s8 rssi = -128; /* if I don't initialise, gcc emits an invalid warning
because it cannot follow the best pointer logic. */
spin_lock_irqsave(&mac->ieee->lock, flags);
list_for_each_entry(net, &mac->ieee->network_list, list) {
/* we're supposed to find the network with
* the best signal here, as we're asked to join
* any network with a specific ESSID, and many
* different ones could have that.
*
* I'll for now just go with the reported rssi.
*
* We also should take into account the rateset
* here to find the best BSSID to try.
*/
if (network_matches_request(mac, net)) {
if (!best) {
best = net;
rssi = best->stats.rssi;
continue;
}
/* we already had a matching network, so
* compare their properties to get the
* better of the two ... (see above)
*/
if (rssi < net->stats.rssi) {
best = net;
rssi = best->stats.rssi;
}
}
}
/* if we unlock here, we might get interrupted and the `best'
* pointer could go stale */
if (best) {
found = ieee80211softmac_create_network(mac, best);
/* if found is still NULL, then we got -ENOMEM somewhere */
if (found)
ieee80211softmac_add_network(mac, found);
}
spin_unlock_irqrestore(&mac->ieee->lock, flags);
}
if (!found) {
if (mac->associnfo.scan_retry > 0) {
spin_lock_irqsave(&mac->lock, flags);
mac->associnfo.scan_retry--;
spin_unlock_irqrestore(&mac->lock, flags);
/* We know of no such network. Let's scan.
* NB: this also happens if we had no memory to copy the network info...
* Maybe we can hope to have more memory after scanning finishes ;)
*/
dprintk(KERN_INFO PFX "Associate: Scanning for networks first.\n");
ieee80211softmac_notify(mac->dev, IEEE80211SOFTMAC_EVENT_SCAN_FINISHED, ieee80211softmac_assoc_notify_scan, NULL);
if (ieee80211softmac_start_scan(mac))
dprintk(KERN_INFO PFX "Associate: failed to initiate scan. Is device up?\n");
return;
} else {
spin_lock_irqsave(&mac->lock, flags);
mac->associnfo.associating = 0;
mac->associated = 0;
spin_unlock_irqrestore(&mac->lock, flags);
dprintk(KERN_INFO PFX "Unable to find matching network after scan!\n");
/* reset the retry counter for the next user request since we
* break out and don't reschedule ourselves after this point. */
mac->associnfo.scan_retry = IEEE80211SOFTMAC_ASSOC_SCAN_RETRY_LIMIT;
ieee80211softmac_call_events(mac, IEEE80211SOFTMAC_EVENT_ASSOCIATE_NET_NOT_FOUND, NULL);
return;
}
}
/* reset the retry counter for the next user request since we
* now found a net and will try to associate to it, but not
* schedule this function again. */
mac->associnfo.scan_retry = IEEE80211SOFTMAC_ASSOC_SCAN_RETRY_LIMIT;
mac->associnfo.bssvalid = 1;
memcpy(mac->associnfo.bssid, found->bssid, ETH_ALEN);
/* copy the ESSID for displaying it */
mac->associnfo.associate_essid.len = found->essid.len;
memcpy(mac->associnfo.associate_essid.data, found->essid.data, IW_ESSID_MAX_SIZE + 1);
/* we found a network! authenticate (if necessary) and associate to it. */
if (found->authenticating) {
dprintk(KERN_INFO PFX "Already requested authentication, waiting...\n");
if(!mac->associnfo.assoc_wait) {
mac->associnfo.assoc_wait = 1;
ieee80211softmac_notify_internal(mac, IEEE80211SOFTMAC_EVENT_ANY, found, ieee80211softmac_assoc_notify_auth, NULL, GFP_KERNEL);
}
return;
}
if (!found->authenticated && !found->authenticating) {
/* This relies on the fact that _auth_req only queues the work,
* otherwise adding the notification would be racy. */
if (!ieee80211softmac_auth_req(mac, found)) {
if(!mac->associnfo.assoc_wait) {
dprintk(KERN_INFO PFX "Cannot associate without being authenticated, requested authentication\n");
mac->associnfo.assoc_wait = 1;
ieee80211softmac_notify_internal(mac, IEEE80211SOFTMAC_EVENT_ANY, found, ieee80211softmac_assoc_notify_auth, NULL, GFP_KERNEL);
}
} else {
printkl(KERN_WARNING PFX "Not authenticated, but requesting authentication failed. Giving up to associate\n");
mac->associnfo.assoc_wait = 0;
ieee80211softmac_call_events(mac, IEEE80211SOFTMAC_EVENT_ASSOCIATE_FAILED, found);
}
return;
}
/* finally! now we can start associating */
mac->associnfo.assoc_wait = 0;
ieee80211softmac_assoc(mac, found);
}
/* call this to do whatever is necessary when we're associated */
static void
ieee80211softmac_associated(struct ieee80211softmac_device *mac,
struct ieee80211_assoc_response * resp,
struct ieee80211softmac_network *net)
{
u16 cap = le16_to_cpu(resp->capability);
u8 erp_value = net->erp_value;
mac->associnfo.associating = 0;
mac->bssinfo.supported_rates = net->supported_rates;
ieee80211softmac_recalc_txrates(mac);
mac->associated = 1;
mac->associnfo.short_preamble_available =
(cap & WLAN_CAPABILITY_SHORT_PREAMBLE) != 0;
ieee80211softmac_process_erp(mac, erp_value);
if (mac->set_bssid_filter)
mac->set_bssid_filter(mac->dev, net->bssid);
memcpy(mac->ieee->bssid, net->bssid, ETH_ALEN);
netif_carrier_on(mac->dev);
mac->association_id = le16_to_cpup(&resp->aid);
}
/* received frame handling functions */
int
ieee80211softmac_handle_assoc_response(struct net_device * dev,
struct ieee80211_assoc_response * resp,
struct ieee80211_network * _ieee80211_network)
{
/* NOTE: the network parameter has to be mostly ignored by
* this code because it is the ieee80211's pointer
* to the struct, not ours (we made a copy)
*/
struct ieee80211softmac_device *mac = ieee80211_priv(dev);
u16 status = le16_to_cpup(&resp->status);
struct ieee80211softmac_network *network = NULL;
unsigned long flags;
if (unlikely(!mac->running))
return -ENODEV;
spin_lock_irqsave(&mac->lock, flags);
if (!mac->associnfo.associating) {
/* we race against the timeout function, so make sure
* only one of us can do work */
spin_unlock_irqrestore(&mac->lock, flags);
return 0;
}
network = ieee80211softmac_get_network_by_bssid_locked(mac, resp->header.addr3);
/* someone sending us things without us knowing him? Ignore. */
if (!network) {
dprintk(KERN_INFO PFX "Received unrequested assocation response from " MAC_FMT "\n", MAC_ARG(resp->header.addr3));
spin_unlock_irqrestore(&mac->lock, flags);
return 0;
}
/* now that we know it was for us, we can cancel the timeout */
cancel_delayed_work(&mac->associnfo.timeout);
/* if the association response included an ERP IE, update our saved
* copy */
if (_ieee80211_network->flags & NETWORK_HAS_ERP_VALUE)
network->erp_value = _ieee80211_network->erp_value;
switch (status) {
case 0:
dprintk(KERN_INFO PFX "associated!\n");
ieee80211softmac_associated(mac, resp, network);
ieee80211softmac_call_events_locked(mac, IEEE80211SOFTMAC_EVENT_ASSOCIATED, network);
break;
case WLAN_REASON_STA_REQ_ASSOC_WITHOUT_AUTH:
if (!network->auth_desynced_once) {
/* there seem to be a few rare cases where our view of
* the world is obscured, or buggy APs that don't DEAUTH
* us properly. So we handle that, but allow it only once.
*/
printkl(KERN_INFO PFX "We were not authenticated during association, retrying...\n");
network->authenticated = 0;
/* we don't want to do this more than once ... */
network->auth_desynced_once = 1;
schedule_work(&mac->associnfo.work);
break;
}
default:
dprintk(KERN_INFO PFX "associating failed (reason: 0x%x)!\n", status);
mac->associnfo.associating = 0;
mac->associnfo.bssvalid = 0;
mac->associated = 0;
ieee80211softmac_call_events_locked(mac, IEEE80211SOFTMAC_EVENT_ASSOCIATE_FAILED, network);
}
spin_unlock_irqrestore(&mac->lock, flags);
return 0;
}
int
ieee80211softmac_handle_disassoc(struct net_device * dev,
struct ieee80211_disassoc *disassoc)
{
struct ieee80211softmac_device *mac = ieee80211_priv(dev);
if (unlikely(!mac->running))
return -ENODEV;
if (memcmp(disassoc->header.addr2, mac->associnfo.bssid, ETH_ALEN))
return 0;
if (memcmp(disassoc->header.addr1, mac->dev->dev_addr, ETH_ALEN))
return 0;
dprintk(KERN_INFO PFX "got disassoc frame\n");
ieee80211softmac_disassoc(mac);
/* try to reassociate */
schedule_work(&mac->associnfo.work);
return 0;
}
int
ieee80211softmac_handle_reassoc_req(struct net_device * dev,
struct ieee80211_reassoc_request * resp)
{
struct ieee80211softmac_device *mac = ieee80211_priv(dev);
struct ieee80211softmac_network *network;
if (unlikely(!mac->running))
return -ENODEV;
network = ieee80211softmac_get_network_by_bssid(mac, resp->header.addr3);
if (!network) {
dprintkl(KERN_INFO PFX "reassoc request from unknown network\n");
return 0;
}
schedule_work(&mac->associnfo.work);
return 0;
}
