From fe3d2c3fe32dd4d0a421ba39caba1cf87402314e Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Tue, 10 Feb 2009 21:26:03 +0100 Subject: [PATCH] mac80211: split managed/ibss code a little more It appears that you can completely mess up mac80211 in IBSS mode by sending it a disassoc or deauth: it'll stop queues and do a lot more but not ever do anything again. Fix this by not handling all those frames in IBSS mode, Signed-off-by: Johannes Berg Signed-off-by: John W. Linville --- net/mac80211/mlme.c | 254 ++++++++++++++++++++++++++++++---------------------- 1 file changed, 146 insertions(+), 108 deletions(-) diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c index 3323974..fbb766a 100644 --- a/net/mac80211/mlme.c +++ b/net/mac80211/mlme.c @@ -808,9 +808,6 @@ static void ieee80211_set_associated(struct ieee80211_sub_if_data *sdata, bss_info_changed |= BSS_CHANGED_ASSOC; ifsta->flags |= IEEE80211_STA_ASSOCIATED; - if (sdata->vif.type != NL80211_IFTYPE_STATION) - return; - bss = ieee80211_rx_bss_get(local, ifsta->bssid, conf->channel->center_freq, ifsta->ssid, ifsta->ssid_len); @@ -1169,6 +1166,30 @@ static void ieee80211_auth_challenge(struct ieee80211_sub_if_data *sdata, elems.challenge_len + 2, 1); } +static void ieee80211_rx_mgmt_auth_ibss(struct ieee80211_sub_if_data *sdata, + struct ieee80211_if_sta *ifsta, + struct ieee80211_mgmt *mgmt, + size_t len) +{ + u16 auth_alg, auth_transaction, status_code; + + if (len < 24 + 6) + return; + + auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg); + auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction); + status_code = le16_to_cpu(mgmt->u.auth.status_code); + + /* + * IEEE 802.11 standard does not require authentication in IBSS + * networks and most implementations do not seem to use it. + * However, try to reply to authentication attempts if someone + * has actually implemented this. + */ + if (auth_alg == WLAN_AUTH_OPEN && auth_transaction == 1) + ieee80211_send_auth(sdata, ifsta, 2, NULL, 0, 0); +} + static void ieee80211_rx_mgmt_auth(struct ieee80211_sub_if_data *sdata, struct ieee80211_if_sta *ifsta, struct ieee80211_mgmt *mgmt, @@ -1176,38 +1197,22 @@ static void ieee80211_rx_mgmt_auth(struct ieee80211_sub_if_data *sdata, { u16 auth_alg, auth_transaction, status_code; - if (ifsta->state != IEEE80211_STA_MLME_AUTHENTICATE && - sdata->vif.type != NL80211_IFTYPE_ADHOC) + if (ifsta->state != IEEE80211_STA_MLME_AUTHENTICATE) return; if (len < 24 + 6) return; - if (sdata->vif.type != NL80211_IFTYPE_ADHOC && - memcmp(ifsta->bssid, mgmt->sa, ETH_ALEN) != 0) + if (memcmp(ifsta->bssid, mgmt->sa, ETH_ALEN) != 0) return; - if (sdata->vif.type != NL80211_IFTYPE_ADHOC && - memcmp(ifsta->bssid, mgmt->bssid, ETH_ALEN) != 0) + if (memcmp(ifsta->bssid, mgmt->bssid, ETH_ALEN) != 0) return; auth_alg = le16_to_cpu(mgmt->u.auth.auth_alg); auth_transaction = le16_to_cpu(mgmt->u.auth.auth_transaction); status_code = le16_to_cpu(mgmt->u.auth.status_code); - if (sdata->vif.type == NL80211_IFTYPE_ADHOC) { - /* - * IEEE 802.11 standard does not require authentication in IBSS - * networks and most implementations do not seem to use it. - * However, try to reply to authentication attempts if someone - * has actually implemented this. - */ - if (auth_alg != WLAN_AUTH_OPEN || auth_transaction != 1) - return; - ieee80211_send_auth(sdata, ifsta, 2, NULL, 0, 0); - return; - } - if (auth_alg != ifsta->auth_alg || auth_transaction != ifsta->auth_transaction) return; @@ -1762,74 +1767,85 @@ static void ieee80211_rx_bss_info(struct ieee80211_sub_if_data *sdata, /* was just updated in ieee80211_bss_info_update */ beacon_timestamp = bss->cbss.tsf; - /* - * In STA mode, the remaining parameters should not be overridden - * by beacons because they're not necessarily accurate there. - */ - if (sdata->vif.type != NL80211_IFTYPE_ADHOC && - bss->last_probe_resp && beacon) { - ieee80211_rx_bss_put(local, bss); - return; - } + if (sdata->vif.type != NL80211_IFTYPE_ADHOC) + goto put_bss; /* check if we need to merge IBSS */ - if (sdata->vif.type == NL80211_IFTYPE_ADHOC && beacon && - (!(sdata->u.sta.flags & IEEE80211_STA_BSSID_SET)) && - bss->cbss.capability & WLAN_CAPABILITY_IBSS && - bss->cbss.channel == local->oper_channel && - elems->ssid_len == sdata->u.sta.ssid_len && + + /* merge only on beacons (???) */ + if (!beacon) + goto put_bss; + + /* we use a fixed BSSID */ + if (sdata->u.sta.flags & IEEE80211_STA_BSSID_SET) + goto put_bss; + + /* not an IBSS */ + if (!(bss->cbss.capability & WLAN_CAPABILITY_IBSS)) + goto put_bss; + + /* different channel */ + if (bss->cbss.channel != local->oper_channel) + goto put_bss; + + /* different SSID */ + if (elems->ssid_len != sdata->u.sta.ssid_len || memcmp(elems->ssid, sdata->u.sta.ssid, - sdata->u.sta.ssid_len) == 0) { - if (rx_status->flag & RX_FLAG_TSFT) { - /* in order for correct IBSS merging we need mactime - * - * since mactime is defined as the time the first data - * symbol of the frame hits the PHY, and the timestamp - * of the beacon is defined as "the time that the data - * symbol containing the first bit of the timestamp is - * transmitted to the PHY plus the transmitting STA’s - * delays through its local PHY from the MAC-PHY - * interface to its interface with the WM" - * (802.11 11.1.2) - equals the time this bit arrives at - * the receiver - we have to take into account the - * offset between the two. - * e.g: at 1 MBit that means mactime is 192 usec earlier - * (=24 bytes * 8 usecs/byte) than the beacon timestamp. - */ - int rate; - if (rx_status->flag & RX_FLAG_HT) { - rate = 65; /* TODO: HT rates */ - } else { - rate = local->hw.wiphy->bands[band]-> - bitrates[rx_status->rate_idx].bitrate; - } - rx_timestamp = rx_status->mactime + (24 * 8 * 10 / rate); - } else if (local && local->ops && local->ops->get_tsf) - /* second best option: get current TSF */ - rx_timestamp = local->ops->get_tsf(local_to_hw(local)); + sdata->u.sta.ssid_len)) + goto put_bss; + + if (rx_status->flag & RX_FLAG_TSFT) { + /* + * For correct IBSS merging we need mactime; since mactime is + * defined as the time the first data symbol of the frame hits + * the PHY, and the timestamp of the beacon is defined as "the + * time that the data symbol containing the first bit of the + * timestamp is transmitted to the PHY plus the transmitting + * STA's delays through its local PHY from the MAC-PHY + * interface to its interface with the WM" (802.11 11.1.2) + * - equals the time this bit arrives at the receiver - we have + * to take into account the offset between the two. + * + * E.g. at 1 MBit that means mactime is 192 usec earlier + * (=24 bytes * 8 usecs/byte) than the beacon timestamp. + */ + int rate; + + if (rx_status->flag & RX_FLAG_HT) + rate = 65; /* TODO: HT rates */ else - /* can't merge without knowing the TSF */ - rx_timestamp = -1LLU; + rate = local->hw.wiphy->bands[band]-> + bitrates[rx_status->rate_idx].bitrate; + + rx_timestamp = rx_status->mactime + (24 * 8 * 10 / rate); + } else if (local && local->ops && local->ops->get_tsf) + /* second best option: get current TSF */ + rx_timestamp = local->ops->get_tsf(local_to_hw(local)); + else + /* can't merge without knowing the TSF */ + rx_timestamp = -1LLU; + #ifdef CONFIG_MAC80211_IBSS_DEBUG - printk(KERN_DEBUG "RX beacon SA=%pM BSSID=" - "%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n", - mgmt->sa, mgmt->bssid, - (unsigned long long)rx_timestamp, - (unsigned long long)beacon_timestamp, - (unsigned long long)(rx_timestamp - beacon_timestamp), - jiffies); -#endif /* CONFIG_MAC80211_IBSS_DEBUG */ - if (beacon_timestamp > rx_timestamp) { + printk(KERN_DEBUG "RX beacon SA=%pM BSSID=" + "%pM TSF=0x%llx BCN=0x%llx diff=%lld @%lu\n", + mgmt->sa, mgmt->bssid, + (unsigned long long)rx_timestamp, + (unsigned long long)beacon_timestamp, + (unsigned long long)(rx_timestamp - beacon_timestamp), + jiffies); +#endif + + if (beacon_timestamp > rx_timestamp) { #ifdef CONFIG_MAC80211_IBSS_DEBUG - printk(KERN_DEBUG "%s: beacon TSF higher than " - "local TSF - IBSS merge with BSSID %pM\n", - sdata->dev->name, mgmt->bssid); + printk(KERN_DEBUG "%s: beacon TSF higher than " + "local TSF - IBSS merge with BSSID %pM\n", + sdata->dev->name, mgmt->bssid); #endif - ieee80211_sta_join_ibss(sdata, &sdata->u.sta, bss); - ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, supp_rates); - } + ieee80211_sta_join_ibss(sdata, &sdata->u.sta, bss); + ieee80211_ibss_add_sta(sdata, mgmt->bssid, mgmt->sa, supp_rates); } + put_bss: ieee80211_rx_bss_put(local, bss); } @@ -1993,8 +2009,7 @@ static void ieee80211_rx_mgmt_probe_req(struct ieee80211_sub_if_data *sdata, struct ieee80211_mgmt *resp; u8 *pos, *end; - if (sdata->vif.type != NL80211_IFTYPE_ADHOC || - ifsta->state != IEEE80211_STA_MLME_IBSS_JOINED || + if (ifsta->state != IEEE80211_STA_MLME_IBSS_JOINED || len < 24 + 2 || !ifsta->probe_resp) return; @@ -2098,31 +2113,54 @@ static void ieee80211_sta_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata, mgmt = (struct ieee80211_mgmt *) skb->data; fc = le16_to_cpu(mgmt->frame_control); - switch (fc & IEEE80211_FCTL_STYPE) { - case IEEE80211_STYPE_PROBE_REQ: - ieee80211_rx_mgmt_probe_req(sdata, ifsta, mgmt, skb->len); - break; - case IEEE80211_STYPE_PROBE_RESP: - ieee80211_rx_mgmt_probe_resp(sdata, mgmt, skb->len, rx_status); - break; - case IEEE80211_STYPE_BEACON: - ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len, rx_status); - break; - case IEEE80211_STYPE_AUTH: - ieee80211_rx_mgmt_auth(sdata, ifsta, mgmt, skb->len); - break; - case IEEE80211_STYPE_ASSOC_RESP: - ieee80211_rx_mgmt_assoc_resp(sdata, ifsta, mgmt, skb->len, 0); - break; - case IEEE80211_STYPE_REASSOC_RESP: - ieee80211_rx_mgmt_assoc_resp(sdata, ifsta, mgmt, skb->len, 1); - break; - case IEEE80211_STYPE_DEAUTH: - ieee80211_rx_mgmt_deauth(sdata, ifsta, mgmt, skb->len); - break; - case IEEE80211_STYPE_DISASSOC: - ieee80211_rx_mgmt_disassoc(sdata, ifsta, mgmt, skb->len); - break; + if (sdata->vif.type == NL80211_IFTYPE_ADHOC) { + switch (fc & IEEE80211_FCTL_STYPE) { + case IEEE80211_STYPE_PROBE_REQ: + ieee80211_rx_mgmt_probe_req(sdata, ifsta, mgmt, + skb->len); + break; + case IEEE80211_STYPE_PROBE_RESP: + ieee80211_rx_mgmt_probe_resp(sdata, mgmt, skb->len, + rx_status); + break; + case IEEE80211_STYPE_BEACON: + ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len, + rx_status); + break; + case IEEE80211_STYPE_AUTH: + ieee80211_rx_mgmt_auth_ibss(sdata, ifsta, mgmt, + skb->len); + break; + } + } else { /* NL80211_IFTYPE_STATION */ + switch (fc & IEEE80211_FCTL_STYPE) { + case IEEE80211_STYPE_PROBE_RESP: + ieee80211_rx_mgmt_probe_resp(sdata, mgmt, skb->len, + rx_status); + break; + case IEEE80211_STYPE_BEACON: + ieee80211_rx_mgmt_beacon(sdata, mgmt, skb->len, + rx_status); + break; + case IEEE80211_STYPE_AUTH: + ieee80211_rx_mgmt_auth(sdata, ifsta, mgmt, skb->len); + break; + case IEEE80211_STYPE_ASSOC_RESP: + ieee80211_rx_mgmt_assoc_resp(sdata, ifsta, mgmt, + skb->len, 0); + break; + case IEEE80211_STYPE_REASSOC_RESP: + ieee80211_rx_mgmt_assoc_resp(sdata, ifsta, mgmt, + skb->len, 1); + break; + case IEEE80211_STYPE_DEAUTH: + ieee80211_rx_mgmt_deauth(sdata, ifsta, mgmt, skb->len); + break; + case IEEE80211_STYPE_DISASSOC: + ieee80211_rx_mgmt_disassoc(sdata, ifsta, mgmt, + skb->len); + break; + } } kfree_skb(skb); -- 2.7.4