From: Johannes Berg Date: Tue, 6 Feb 2024 14:54:08 +0000 (+0200) Subject: wifi: cfg80211: optionally support monitor on disabled channels X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=a110a3b79177ddd7e7295671df97fb5386406835;p=linux.git wifi: cfg80211: optionally support monitor on disabled channels If the hardware supports a disabled channel, it may in some cases be possible to use monitor mode (without any transmit) on it when it's otherwise disabled. Add a new channel flag IEEE80211_CHAN_CAN_MONITOR that makes it possible for a driver to indicate such a thing. Make it per channel so drivers could have a choice with it, perhaps it's only possible on some channels, perhaps some channels are not supported at all, but still there and marked disabled. In _nl80211_parse_chandef() simplify the code and check only for an unknown channel, _cfg80211_chandef_usable() will later check for IEEE80211_CHAN_DISABLED anyway. Signed-off-by: Johannes Berg Signed-off-by: Miri Korenblit Link: https://msgid.link/20240206164849.87fad3a21a09.I9116b2fdc2e2c9fd59a9273a64db7fcb41fc0328@changeid Signed-off-by: Johannes Berg --- diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h index 7bb8484e859e6..0a3151587556e 100644 --- a/include/net/cfg80211.h +++ b/include/net/cfg80211.h @@ -122,6 +122,9 @@ struct wiphy; * not permitted using this channel * @IEEE80211_CHAN_NO_6GHZ_AFC_CLIENT: Client connection with AFC AP * not permitted using this channel + * @IEEE80211_CHAN_CAN_MONITOR: This channel can be used for monitor + * mode even in the presence of other (regulatory) restrictions, + * even if it is otherwise disabled. */ enum ieee80211_channel_flags { IEEE80211_CHAN_DISABLED = 1<<0, @@ -148,6 +151,7 @@ enum ieee80211_channel_flags { IEEE80211_CHAN_DFS_CONCURRENT = 1<<21, IEEE80211_CHAN_NO_6GHZ_VLP_CLIENT = 1<<22, IEEE80211_CHAN_NO_6GHZ_AFC_CLIENT = 1<<23, + IEEE80211_CHAN_CAN_MONITOR = 1<<24, }; #define IEEE80211_CHAN_NO_HT40 \ diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h index 13fa10804909a..546cc176c2a99 100644 --- a/include/uapi/linux/nl80211.h +++ b/include/uapi/linux/nl80211.h @@ -4273,6 +4273,9 @@ enum nl80211_wmm_rule { * not allowed using this channel * @NL80211_FREQUENCY_ATTR_NO_6GHZ_AFC_CLIENT: Client connection to AFC AP * not allowed using this channel + * @NL80211_FREQUENCY_ATTR_CAN_MONITOR: This channel can be used in monitor + * mode despite other (regulatory) restrictions, even if the channel is + * otherwise completely disabled. * @NL80211_FREQUENCY_ATTR_MAX: highest frequency attribute number * currently defined * @__NL80211_FREQUENCY_ATTR_AFTER_LAST: internal use @@ -4315,6 +4318,7 @@ enum nl80211_frequency_attr { NL80211_FREQUENCY_ATTR_DFS_CONCURRENT, NL80211_FREQUENCY_ATTR_NO_6GHZ_VLP_CLIENT, NL80211_FREQUENCY_ATTR_NO_6GHZ_AFC_CLIENT, + NL80211_FREQUENCY_ATTR_CAN_MONITOR, /* keep last */ __NL80211_FREQUENCY_ATTR_AFTER_LAST, diff --git a/net/wireless/chan.c b/net/wireless/chan.c index e2ce89afa9ffe..3414b2c3abcc5 100644 --- a/net/wireless/chan.c +++ b/net/wireless/chan.c @@ -1145,7 +1145,7 @@ EXPORT_SYMBOL(cfg80211_chandef_dfs_cac_time); static bool cfg80211_secondary_chans_ok(struct wiphy *wiphy, u32 center_freq, u32 bandwidth, - u32 prohibited_flags) + u32 prohibited_flags, bool monitor) { struct ieee80211_channel *c; u32 freq, start_freq, end_freq; @@ -1155,7 +1155,11 @@ static bool cfg80211_secondary_chans_ok(struct wiphy *wiphy, for (freq = start_freq; freq <= end_freq; freq += MHZ_TO_KHZ(20)) { c = ieee80211_get_channel_khz(wiphy, freq); - if (!c || c->flags & prohibited_flags) + if (!c) + return false; + if (monitor && c->flags & IEEE80211_CHAN_CAN_MONITOR) + continue; + if (c->flags & prohibited_flags) return false; } @@ -1215,9 +1219,9 @@ static bool cfg80211_edmg_usable(struct wiphy *wiphy, u8 edmg_channels, return true; } -bool cfg80211_chandef_usable(struct wiphy *wiphy, - const struct cfg80211_chan_def *chandef, - u32 prohibited_flags) +bool _cfg80211_chandef_usable(struct wiphy *wiphy, + const struct cfg80211_chan_def *chandef, + u32 prohibited_flags, bool monitor) { struct ieee80211_sta_ht_cap *ht_cap; struct ieee80211_sta_vht_cap *vht_cap; @@ -1379,14 +1383,22 @@ bool cfg80211_chandef_usable(struct wiphy *wiphy, if (!cfg80211_secondary_chans_ok(wiphy, ieee80211_chandef_to_khz(chandef), - width, prohibited_flags)) + width, prohibited_flags, monitor)) return false; if (!chandef->center_freq2) return true; return cfg80211_secondary_chans_ok(wiphy, MHZ_TO_KHZ(chandef->center_freq2), - width, prohibited_flags); + width, prohibited_flags, monitor); +} + +bool cfg80211_chandef_usable(struct wiphy *wiphy, + const struct cfg80211_chan_def *chandef, + u32 prohibited_flags) +{ + return _cfg80211_chandef_usable(wiphy, chandef, prohibited_flags, + false); } EXPORT_SYMBOL(cfg80211_chandef_usable); diff --git a/net/wireless/core.h b/net/wireless/core.h index debf63e6c61fc..118f2f6198289 100644 --- a/net/wireless/core.h +++ b/net/wireless/core.h @@ -3,7 +3,7 @@ * Wireless configuration interface internals. * * Copyright 2006-2010 Johannes Berg - * Copyright (C) 2018-2023 Intel Corporation + * Copyright (C) 2018-2024 Intel Corporation */ #ifndef __NET_WIRELESS_CORE_H #define __NET_WIRELESS_CORE_H @@ -492,6 +492,9 @@ bool cfg80211_is_sub_chan(struct cfg80211_chan_def *chandef, bool cfg80211_wdev_on_sub_chan(struct wireless_dev *wdev, struct ieee80211_channel *chan, bool primary_only); +bool _cfg80211_chandef_usable(struct wiphy *wiphy, + const struct cfg80211_chan_def *chandef, + u32 prohibited_flags, bool monitor); static inline unsigned int elapsed_jiffies_msecs(unsigned long start) { diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index 3b3b511f9f69e..612ca99fbf39c 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -3218,9 +3218,9 @@ static bool nl80211_can_set_dev_channel(struct wireless_dev *wdev) wdev->iftype == NL80211_IFTYPE_P2P_GO; } -int nl80211_parse_chandef(struct cfg80211_registered_device *rdev, - struct genl_info *info, - struct cfg80211_chan_def *chandef) +static int _nl80211_parse_chandef(struct cfg80211_registered_device *rdev, + struct genl_info *info, bool monitor, + struct cfg80211_chan_def *chandef) { struct netlink_ext_ack *extack = info->extack; struct nlattr **attrs = info->attrs; @@ -3245,10 +3245,9 @@ int nl80211_parse_chandef(struct cfg80211_registered_device *rdev, chandef->freq1_offset = control_freq % 1000; chandef->center_freq2 = 0; - /* Primary channel not allowed */ - if (!chandef->chan || chandef->chan->flags & IEEE80211_CHAN_DISABLED) { + if (!chandef->chan) { NL_SET_ERR_MSG_ATTR(extack, attrs[NL80211_ATTR_WIPHY_FREQ], - "Channel is disabled"); + "Unknown channel"); return -EINVAL; } @@ -3343,8 +3342,9 @@ int nl80211_parse_chandef(struct cfg80211_registered_device *rdev, return -EINVAL; } - if (!cfg80211_chandef_usable(&rdev->wiphy, chandef, - IEEE80211_CHAN_DISABLED)) { + if (!_cfg80211_chandef_usable(&rdev->wiphy, chandef, + IEEE80211_CHAN_DISABLED, + monitor)) { NL_SET_ERR_MSG(extack, "(extension) channel is disabled"); return -EINVAL; } @@ -3359,6 +3359,13 @@ int nl80211_parse_chandef(struct cfg80211_registered_device *rdev, return 0; } +int nl80211_parse_chandef(struct cfg80211_registered_device *rdev, + struct genl_info *info, + struct cfg80211_chan_def *chandef) +{ + return _nl80211_parse_chandef(rdev, info, false, chandef); +} + static int __nl80211_set_channel(struct cfg80211_registered_device *rdev, struct net_device *dev, struct genl_info *info, @@ -3383,7 +3390,9 @@ static int __nl80211_set_channel(struct cfg80211_registered_device *rdev, link_id = 0; } - result = nl80211_parse_chandef(rdev, info, &chandef); + result = _nl80211_parse_chandef(rdev, info, + iftype == NL80211_IFTYPE_MONITOR, + &chandef); if (result) return result;