diff options
Diffstat (limited to 'net/mac80211/rx.c')
| -rw-r--r-- | net/mac80211/rx.c | 113 |
1 files changed, 70 insertions, 43 deletions
diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c index b0959c249869..08ca066246b9 100644 --- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -310,52 +310,77 @@ static ieee80211_txrx_result ieee80211_rx_h_load_key(struct ieee80211_txrx_data *rx) { struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) rx->skb->data; - int always_sta_key; + int keyidx; + int hdrlen; - if (rx->sdata->type == IEEE80211_IF_TYPE_STA) - always_sta_key = 0; - else - always_sta_key = 1; + /* + * Key selection 101 + * + * There are three types of keys: + * - GTK (group keys) + * - PTK (pairwise keys) + * - STK (station-to-station pairwise keys) + * + * When selecting a key, we have to distinguish between multicast + * (including broadcast) and unicast frames, the latter can only + * use PTKs and STKs while the former always use GTKs. Unless, of + * course, actual WEP keys ("pre-RSNA") are used, then unicast + * frames can also use key indizes like GTKs. Hence, if we don't + * have a PTK/STK we check the key index for a WEP key. + * + * There is also a slight problem in IBSS mode: GTKs are negotiated + * with each station, that is something we don't currently handle. + */ + + if (!(rx->fc & IEEE80211_FCTL_PROTECTED)) + return TXRX_CONTINUE; - if (rx->sta && rx->sta->key && always_sta_key) { + /* + * No point in finding a key if the frame is neither + * addressed to us nor a multicast frame. + */ + if (!rx->u.rx.ra_match) + return TXRX_CONTINUE; + + if (!is_multicast_ether_addr(hdr->addr1) && rx->sta && rx->sta->key) { rx->key = rx->sta->key; } else { - if (rx->sta && rx->sta->key) - rx->key = rx->sta->key; - else - rx->key = rx->sdata->default_key; + /* + * The device doesn't give us the IV so we won't be + * able to look up the key. That's ok though, we + * don't need to decrypt the frame, we just won't + * be able to keep statistics accurate. + * Except for key threshold notifications, should + * we somehow allow the driver to tell us which key + * the hardware used if this flag is set? + */ + if (!(rx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV)) + return TXRX_CONTINUE; - if ((rx->local->hw.flags & IEEE80211_HW_WEP_INCLUDE_IV) && - rx->fc & IEEE80211_FCTL_PROTECTED) { - int keyidx = ieee80211_wep_get_keyidx(rx->skb); + hdrlen = ieee80211_get_hdrlen(rx->fc); - if (keyidx >= 0 && keyidx < NUM_DEFAULT_KEYS && - (!rx->sta || !rx->sta->key || keyidx > 0)) - rx->key = rx->sdata->keys[keyidx]; + if (rx->skb->len < 8 + hdrlen) + return TXRX_DROP; /* TODO: count this? */ - if (!rx->key) { - if (!rx->u.rx.ra_match) - return TXRX_DROP; - if (net_ratelimit()) - printk(KERN_DEBUG "%s: RX WEP frame " - "with unknown keyidx %d " - "(A1=" MAC_FMT - " A2=" MAC_FMT - " A3=" MAC_FMT ")\n", - rx->dev->name, keyidx, - MAC_ARG(hdr->addr1), - MAC_ARG(hdr->addr2), - MAC_ARG(hdr->addr3)); - /* - * TODO: notify userspace about this - * via cfg/nl80211 - */ - return TXRX_DROP; - } - } + /* + * no need to call ieee80211_wep_get_keyidx, + * it verifies a bunch of things we've done already + */ + keyidx = rx->skb->data[hdrlen + 3] >> 6; + + rx->key = rx->sdata->keys[keyidx]; + + /* + * RSNA-protected unicast frames should always be sent with + * pairwise or station-to-station keys, but for WEP we allow + * using a key index as well. + */ + if (rx->key && rx->key->alg != ALG_WEP && + !is_multicast_ether_addr(hdr->addr1)) + rx->key = NULL; } - if (rx->fc & IEEE80211_FCTL_PROTECTED && rx->key && rx->u.rx.ra_match) { + if (rx->key) { rx->key->tx_rx_count++; if (unlikely(rx->local->key_tx_rx_threshold && rx->key->tx_rx_count > @@ -516,10 +541,6 @@ ieee80211_rx_h_wep_weak_iv_detection(struct ieee80211_txrx_data *rx) static ieee80211_txrx_result ieee80211_rx_h_wep_decrypt(struct ieee80211_txrx_data *rx) { - /* If the device handles decryption totally, skip this test */ - if (rx->local->hw.flags & IEEE80211_HW_DEVICE_HIDES_WEP) - return TXRX_CONTINUE; - if ((rx->key && rx->key->alg != ALG_WEP) || !(rx->fc & IEEE80211_FCTL_PROTECTED) || ((rx->fc & IEEE80211_FCTL_FTYPE) != IEEE80211_FTYPE_DATA && @@ -871,8 +892,14 @@ ieee80211_rx_h_802_1x_pae(struct ieee80211_txrx_data *rx) static ieee80211_txrx_result ieee80211_rx_h_drop_unencrypted(struct ieee80211_txrx_data *rx) { - /* If the device handles decryption totally, skip this test */ - if (rx->local->hw.flags & IEEE80211_HW_DEVICE_HIDES_WEP) + /* + * Pass through unencrypted frames if the hardware might have + * decrypted them already without telling us, but that can only + * be true if we either didn't find a key or the found key is + * uploaded to the hardware. + */ + if ((rx->local->hw.flags & IEEE80211_HW_DEVICE_HIDES_WEP) && + (!rx->key || !rx->key->force_sw_encrypt)) return TXRX_CONTINUE; /* Drop unencrypted frames if key is set. */ |