/* * 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_txrates(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) { mac->associnfo.associating = 0; mac->associnfo.supported_rates = net->supported_rates; ieee80211softmac_recalc_txrates(mac); mac->associated = 1; 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_do_not_use) { /* NOTE: the network parameter has to be 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); 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; }