diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index b1d18d967d8..38c98061251 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -308,6 +308,8 @@ struct ieee80211_if_managed { int auth_alg; /* currently used IEEE 802.11 authentication algorithm */ int auth_transaction; + u32 beacon_crc; + enum { IEEE80211_MFP_DISABLED, IEEE80211_MFP_OPTIONAL, @@ -1085,6 +1087,9 @@ void ieee80211_tx_skb(struct ieee80211_sub_if_data *sdata, struct sk_buff *skb, int encrypt); void ieee802_11_parse_elems(u8 *start, size_t len, struct ieee802_11_elems *elems); +u32 ieee802_11_parse_elems_crc(u8 *start, size_t len, + struct ieee802_11_elems *elems, + u64 filter, u32 crc); int ieee80211_set_freq(struct ieee80211_sub_if_data *sdata, int freq); u32 ieee80211_mandatory_rates(struct ieee80211_local *local, enum ieee80211_band band); diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c index c39a214e7ad..7a8d4c49424 100644 --- a/net/mac80211/mlme.c +++ b/net/mac80211/mlme.c @@ -18,6 +18,7 @@ #include #include #include +#include #include #include @@ -1752,46 +1753,73 @@ static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata, ifmgd->flags &= ~IEEE80211_STA_PROBEREQ_POLL; } +/* + * This is the canonical list of information elements we care about, + * the filter code also gives us all changes to the Microsoft OUI + * (00:50:F2) vendor IE which is used for WMM which we need to track. + * + * We implement beacon filtering in software since that means we can + * avoid processing the frame here and in cfg80211, and userspace + * will not be able to tell whether the hardware supports it or not. + * + * XXX: This list needs to be dynamic -- userspace needs to be able to + * add items it requires. It also needs to be able to tell us to + * look out for other vendor IEs. + */ +static const u64 care_about_ies = + BIT(WLAN_EID_COUNTRY) | + BIT(WLAN_EID_ERP_INFO) | + BIT(WLAN_EID_CHANNEL_SWITCH) | + BIT(WLAN_EID_PWR_CONSTRAINT) | + BIT(WLAN_EID_HT_CAPABILITY) | + BIT(WLAN_EID_HT_INFORMATION); + static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata, struct ieee80211_mgmt *mgmt, size_t len, struct ieee80211_rx_status *rx_status) { - struct ieee80211_if_managed *ifmgd; + struct ieee80211_if_managed *ifmgd = &sdata->u.mgd; size_t baselen; struct ieee802_11_elems elems; struct ieee80211_local *local = sdata->local; u32 changed = 0; - bool erp_valid, directed_tim; + bool erp_valid, directed_tim = false; u8 erp_value = 0; + u32 ncrc; /* Process beacon from the current BSS */ baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt; if (baselen > len) return; - ieee802_11_parse_elems(mgmt->u.beacon.variable, len - baselen, &elems); - - ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true); - - if (sdata->vif.type != NL80211_IFTYPE_STATION) + if (rx_status->freq != local->hw.conf.channel->center_freq) return; - ifmgd = &sdata->u.mgd; - if (!(ifmgd->flags & IEEE80211_STA_ASSOCIATED) || memcmp(ifmgd->bssid, mgmt->bssid, ETH_ALEN) != 0) return; - if (rx_status->freq != local->hw.conf.channel->center_freq) + ncrc = crc32_be(0, (void *)&mgmt->u.beacon.beacon_int, 4); + ncrc = ieee802_11_parse_elems_crc(mgmt->u.beacon.variable, + len - baselen, &elems, + care_about_ies, ncrc); + + if (local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK) + directed_tim = ieee80211_check_tim(&elems, ifmgd->aid); + + ncrc = crc32_be(ncrc, (void *)&directed_tim, sizeof(directed_tim)); + + if (ncrc == ifmgd->beacon_crc) return; + ifmgd->beacon_crc = ncrc; + + ieee80211_rx_bss_info(sdata, mgmt, len, rx_status, &elems, true); ieee80211_sta_wmm_params(local, ifmgd, elems.wmm_param, elems.wmm_param_len); if (local->hw.flags & IEEE80211_HW_PS_NULLFUNC_STACK) { - directed_tim = ieee80211_check_tim(&elems, ifmgd->aid); - if (directed_tim) { if (local->hw.conf.dynamic_ps_timeout > 0) { local->hw.conf.flags &= ~IEEE80211_CONF_PS; diff --git a/net/mac80211/util.c b/net/mac80211/util.c index b361e2acfce..3dd490fa4b6 100644 --- a/net/mac80211/util.c +++ b/net/mac80211/util.c @@ -20,6 +20,7 @@ #include #include #include +#include #include #include #include @@ -536,9 +537,17 @@ EXPORT_SYMBOL_GPL(ieee80211_iterate_active_interfaces_atomic); void ieee802_11_parse_elems(u8 *start, size_t len, struct ieee802_11_elems *elems) +{ + ieee802_11_parse_elems_crc(start, len, elems, 0, 0); +} + +u32 ieee802_11_parse_elems_crc(u8 *start, size_t len, + struct ieee802_11_elems *elems, + u64 filter, u32 crc) { size_t left = len; u8 *pos = start; + bool calc_crc = filter != 0; memset(elems, 0, sizeof(*elems)); elems->ie_start = start; @@ -552,7 +561,10 @@ void ieee802_11_parse_elems(u8 *start, size_t len, left -= 2; if (elen > left) - return; + break; + + if (calc_crc && id < 64 && (filter & BIT(id))) + crc = crc32_be(crc, pos - 2, elen + 2); switch (id) { case WLAN_EID_SSID: @@ -587,15 +599,20 @@ void ieee802_11_parse_elems(u8 *start, size_t len, elems->challenge = pos; elems->challenge_len = elen; break; - case WLAN_EID_WPA: + case WLAN_EID_VENDOR_SPECIFIC: if (elen >= 4 && pos[0] == 0x00 && pos[1] == 0x50 && pos[2] == 0xf2) { /* Microsoft OUI (00:50:F2) */ + + if (calc_crc) + crc = crc32_be(crc, pos - 2, elen + 2); + if (pos[3] == 1) { /* OUI Type 1 - WPA IE */ elems->wpa = pos; elems->wpa_len = elen; } else if (elen >= 5 && pos[3] == 2) { + /* OUI Type 2 - WMM IE */ if (pos[4] == 0) { elems->wmm_info = pos; elems->wmm_info_len = elen; @@ -680,6 +697,8 @@ void ieee802_11_parse_elems(u8 *start, size_t len, left -= elen; pos += elen; } + + return crc; } void ieee80211_set_wmm_default(struct ieee80211_sub_if_data *sdata)