From f8d504caa9739f74c7c399e158a7dce8478b866e Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Mon, 28 Sep 2020 13:06:56 +0200 Subject: [PATCH] nl80211: reduce non-split wiphy dump size When wiphy dumps cannot be split, such as in events or with older userspace that doesn't support it, the size can today be too big. Reduce it, by doing two things: 1) remove data that couldn't have been present before the split capability was introduced since it's new, such as HE capabilities 2) as suggested by Martin Willi, remove management frame subtypes from the split dumps, as just (1) isn't even enough due to other new code capabilities. This is fine as old consumers (really just wpa_supplicant) didn't check this data before they got support for split dumps. Reported-by: Martin Willi Suggested-by: Martin Willi Signed-off-by: Johannes Berg Tested-by: Martin Willi Link: https://lore.kernel.org/r/20200928130655.53bce7873164.I71f06c9a221cd0630429a1a56eeae68a13beca61@changeid Signed-off-by: Johannes Berg --- net/wireless/nl80211.c | 37 ++++++++++++++++++++++++------------- 1 file changed, 24 insertions(+), 13 deletions(-) diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index d76b8bd0e1d1..d0e2d144cb94 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -984,6 +984,8 @@ static int nl80211_msg_put_channel(struct sk_buff *msg, struct wiphy *wiphy, if (!large && chan->flags & (IEEE80211_CHAN_NO_10MHZ | IEEE80211_CHAN_NO_20MHZ)) return 0; + if (!large && chan->freq_offset) + return 0; if (nla_put_u32(msg, NL80211_FREQUENCY_ATTR_FREQ, chan->center_freq)) @@ -1676,7 +1678,8 @@ nl80211_send_iftype_data(struct sk_buff *msg, } static int nl80211_send_band_rateinfo(struct sk_buff *msg, - struct ieee80211_supported_band *sband) + struct ieee80211_supported_band *sband, + bool large) { struct nlattr *nl_rates, *nl_rate; struct ieee80211_rate *rate; @@ -1704,7 +1707,7 @@ static int nl80211_send_band_rateinfo(struct sk_buff *msg, sband->vht_cap.cap))) return -ENOBUFS; - if (sband->n_iftype_data) { + if (large && sband->n_iftype_data) { struct nlattr *nl_iftype_data = nla_nest_start_noflag(msg, NL80211_BAND_ATTR_IFTYPE_DATA); @@ -1732,7 +1735,7 @@ static int nl80211_send_band_rateinfo(struct sk_buff *msg, } /* add EDMG info */ - if (sband->edmg_cap.channels && + if (large && sband->edmg_cap.channels && (nla_put_u8(msg, NL80211_BAND_ATTR_EDMG_CHANNELS, sband->edmg_cap.channels) || nla_put_u8(msg, NL80211_BAND_ATTR_EDMG_BW_CONFIG, @@ -2150,13 +2153,7 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *rdev, nla_put_u16(msg, NL80211_ATTR_MAX_SCHED_SCAN_IE_LEN, rdev->wiphy.max_sched_scan_ie_len) || nla_put_u8(msg, NL80211_ATTR_MAX_MATCH_SETS, - rdev->wiphy.max_match_sets) || - nla_put_u32(msg, NL80211_ATTR_MAX_NUM_SCHED_SCAN_PLANS, - rdev->wiphy.max_sched_scan_plans) || - nla_put_u32(msg, NL80211_ATTR_MAX_SCAN_PLAN_INTERVAL, - rdev->wiphy.max_sched_scan_plan_interval) || - nla_put_u32(msg, NL80211_ATTR_MAX_SCAN_PLAN_ITERATIONS, - rdev->wiphy.max_sched_scan_plan_iterations)) + rdev->wiphy.max_match_sets)) goto nla_put_failure; if ((rdev->wiphy.flags & WIPHY_FLAG_IBSS_RSN) && @@ -2246,6 +2243,10 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *rdev, band < NUM_NL80211_BANDS; band++) { struct ieee80211_supported_band *sband; + /* omit higher bands for ancient software */ + if (band > NL80211_BAND_5GHZ && !state->split) + break; + sband = rdev->wiphy.bands[band]; if (!sband) @@ -2257,7 +2258,8 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *rdev, switch (state->chan_start) { case 0: - if (nl80211_send_band_rateinfo(msg, sband)) + if (nl80211_send_band_rateinfo(msg, sband, + state->split)) goto nla_put_failure; state->chan_start++; if (state->split) @@ -2359,8 +2361,6 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *rdev, nla_put_flag(msg, NL80211_ATTR_OFFCHANNEL_TX_OK)) goto nla_put_failure; - if (nl80211_send_mgmt_stypes(msg, mgmt_stypes)) - goto nla_put_failure; state->split_start++; if (state->split) break; @@ -2431,6 +2431,17 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *rdev, state->split_start++; break; case 9: + if (nl80211_send_mgmt_stypes(msg, mgmt_stypes)) + goto nla_put_failure; + + if (nla_put_u32(msg, NL80211_ATTR_MAX_NUM_SCHED_SCAN_PLANS, + rdev->wiphy.max_sched_scan_plans) || + nla_put_u32(msg, NL80211_ATTR_MAX_SCAN_PLAN_INTERVAL, + rdev->wiphy.max_sched_scan_plan_interval) || + nla_put_u32(msg, NL80211_ATTR_MAX_SCAN_PLAN_ITERATIONS, + rdev->wiphy.max_sched_scan_plan_iterations)) + goto nla_put_failure; + if (rdev->wiphy.extended_capabilities && (nla_put(msg, NL80211_ATTR_EXT_CAPA, rdev->wiphy.extended_capabilities_len,