diff options
| -rw-r--r-- | include/linux/ieee80211.h | 3 | ||||
| -rw-r--r-- | net/mac80211/ieee80211_i.h | 1 | ||||
| -rw-r--r-- | net/mac80211/mlme.c | 60 | ||||
| -rw-r--r-- | net/mac80211/util.c | 25 |
4 files changed, 77 insertions, 12 deletions
diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h index 77d4f26..61a09f0 100644 --- a/include/linux/ieee80211.h +++ b/include/linux/ieee80211.h @@ -1824,7 +1824,8 @@ enum ieee80211_eid { WLAN_EID_DMG_TSPEC = 146, WLAN_EID_DMG_AT = 147, WLAN_EID_DMG_CAP = 148, - /* 149-150 reserved for Cisco */ + /* 149 reserved for Cisco */ + WLAN_EID_CISCO_VENDOR_SPECIFIC = 150, WLAN_EID_DMG_OPERATION = 151, WLAN_EID_DMG_BSS_PARAM_CHANGE = 152, WLAN_EID_DMG_BEAM_REFINEMENT = 153, diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index 6b7bdd8..c2aaec4 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -1369,6 +1369,7 @@ struct ieee802_11_elems { const struct ieee80211_wide_bw_chansw_ie *wide_bw_chansw_ie; const u8 *country_elem; const u8 *pwr_constr_elem; + const u8 *cisco_dtpc_elem; const struct ieee80211_timeout_interval_ie *timeout_int; const u8 *opmode_notif; const struct ieee80211_sec_chan_offs_ie *sec_chan_offs; diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c index 0b812a8..a7b92f5 100644 --- a/net/mac80211/mlme.c +++ b/net/mac80211/mlme.c @@ -1230,14 +1230,30 @@ ieee80211_find_80211h_pwr_constr(struct ieee80211_sub_if_data *sdata, return have_chan_pwr; } +static void ieee80211_find_cisco_dtpc(struct ieee80211_sub_if_data *sdata, + struct ieee80211_channel *channel, + const u8 *cisco_dtpc_ie, + int *pwr_level) +{ + /* From practical testing, the first data byte of the DTPC element + * seems to contain the requested dBm level, and the CLI on Cisco + * APs clearly state the range is -127 to 127 dBm, which indicates + * a signed byte, although it seemingly never actually goes negative. + * The other byte seems to always be zero. + */ + *pwr_level = (__s8)cisco_dtpc_ie[4]; +} + static u32 ieee80211_handle_pwr_constr(struct ieee80211_sub_if_data *sdata, struct ieee80211_channel *channel, struct ieee80211_mgmt *mgmt, const u8 *country_ie, u8 country_ie_len, - const u8 *pwr_constr_ie) + const u8 *pwr_constr_ie, + const u8 *cisco_dtpc_ie) { - bool has_80211h_pwr = false; - int chan_pwr, pwr_reduction_80211h; + bool has_80211h_pwr = false, has_cisco_pwr = false; + int chan_pwr = 0, pwr_reduction_80211h = 0; + int pwr_level_cisco, pwr_level_80211h; int new_ap_level; if (country_ie && pwr_constr_ie && @@ -1246,16 +1262,35 @@ static u32 ieee80211_handle_pwr_constr(struct ieee80211_sub_if_data *sdata, has_80211h_pwr = ieee80211_find_80211h_pwr_constr( sdata, channel, country_ie, country_ie_len, pwr_constr_ie, &chan_pwr, &pwr_reduction_80211h); - new_ap_level = max_t(int, 0, chan_pwr - pwr_reduction_80211h); + pwr_level_80211h = + max_t(int, 0, chan_pwr - pwr_reduction_80211h); + } + + if (cisco_dtpc_ie) { + ieee80211_find_cisco_dtpc( + sdata, channel, cisco_dtpc_ie, &pwr_level_cisco); + has_cisco_pwr = true; } - if (!has_80211h_pwr) + if (!has_80211h_pwr && !has_cisco_pwr) return 0; - sdata_info(sdata, - "Limiting TX power to %d (%d - %d) dBm as advertised by %pM\n", - new_ap_level, chan_pwr, pwr_reduction_80211h, - sdata->u.mgd.bssid); + /* If we have both 802.11h and Cisco DTPC, apply both limits + * by picking the smallest of the two power levels advertised. + */ + if (has_80211h_pwr && + (!has_cisco_pwr || pwr_level_80211h <= pwr_level_cisco)) { + sdata_info(sdata, + "Limiting TX power to %d (%d - %d) dBm as advertised by %pM\n", + pwr_level_80211h, chan_pwr, pwr_reduction_80211h, + sdata->u.mgd.bssid); + new_ap_level = pwr_level_80211h; + } else { /* has_cisco_pwr is always true here. */ + sdata_info(sdata, + "Limiting TX power to %d dBm as advertised by %pM\n", + pwr_level_cisco, sdata->u.mgd.bssid); + new_ap_level = pwr_level_cisco; + } if (sdata->ap_power_level == new_ap_level) return 0; @@ -2923,7 +2958,9 @@ static void ieee80211_rx_mgmt_probe_resp(struct ieee80211_sub_if_data *sdata, /* * 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. + * (00:50:F2) vendor IE which is used for WMM which we need to track, + * as well as the DTPC IE (part of the Cisco OUI) used for signaling + * changes to requested client power. * * We implement beacon filtering in software since that means we can * avoid processing the frame here and in cfg80211, and userspace @@ -3232,7 +3269,8 @@ static void ieee80211_rx_mgmt_beacon(struct ieee80211_sub_if_data *sdata, changed |= ieee80211_handle_pwr_constr(sdata, chan, mgmt, elems.country_elem, elems.country_elem_len, - elems.pwr_constr_elem); + elems.pwr_constr_elem, + elems.cisco_dtpc_elem); ieee80211_bss_info_change_notify(sdata, changed); } diff --git a/net/mac80211/util.c b/net/mac80211/util.c index b444f27..3c61060 100644 --- a/net/mac80211/util.c +++ b/net/mac80211/util.c @@ -1015,6 +1015,31 @@ u32 ieee802_11_parse_elems_crc(const u8 *start, size_t len, bool action, } elems->pwr_constr_elem = pos; break; + case WLAN_EID_CISCO_VENDOR_SPECIFIC: + /* Lots of different options exist, but we only care + * about the Dynamic Transmit Power Control element. + * First check for the Cisco OUI, then for the DTPC + * tag (0x00). + */ + if (elen < 4) { + elem_parse_failed = true; + break; + } + + if (pos[0] != 0x00 || pos[1] != 0x40 || + pos[2] != 0x96 || pos[3] != 0x00) + break; + + if (elen != 6) { + elem_parse_failed = true; + break; + } + + if (calc_crc) + crc = crc32_be(crc, pos - 2, elen + 2); + + elems->cisco_dtpc_elem = pos; + break; case WLAN_EID_TIMEOUT_INTERVAL: if (elen >= sizeof(struct ieee80211_timeout_interval_ie)) elems->timeout_int = (void *)pos; 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