[PATCH] wireless: deprecate WDS and disable by default

[Johannes Berg]

From: Johannes Berg <***@intel.com>

The old WDS 4-addr frame support is very limited, e.g.
* no encryption is possible on such links
* it cannot support rate/HT/VHT negotiation
* management APIs are very restricted

These make the WDS legacy mode useless in practice.

All of these are resolved by the 4-addr AP/client support,
so there's also no reason to improve WDS in the future.

Therefore, add a Kconfig option to disable legacy WDS.
This gives people an "emergency valve" while they migrate
to the better-supported 4-addr AP/client option; we plan
to remove it (and the associated cfg80211/mac80211 code,
which is the ultimate goal) in the future.

Signed-off-by: Johannes Berg <***@intel.com>
---
drivers/net/wireless/Kconfig | 13 +++++++++++++
drivers/net/wireless/ath/ath9k/init.c | 6 ++++++
drivers/net/wireless/broadcom/b43/main.c | 2 ++
drivers/net/wireless/broadcom/b43legacy/main.c | 2 ++
drivers/net/wireless/ralink/rt2x00/rt2x00dev.c | 6 ++++--
net/wireless/core.c | 10 ++++++++++
6 files changed, 37 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/Kconfig b/drivers/net/wireless/Kconfig
index 8c8edaf1bba6..fa9c4fa9477e 100644
--- a/drivers/net/wireless/Kconfig
+++ b/drivers/net/wireless/Kconfig
@@ -17,6 +17,19 @@ menuconfig WLAN

if WLAN

+config WIRELESS_WDS
+ bool "mac80211-based legacy WDS support"
+ help
+ This option enables the deprecated WDS support, the newer
+ mac80211-based 4-addr AP/client support supersedes it with
+ a much better feature set (HT, VHT, ...)
+
+ We plan to remove this option and code, so if you find
+ that you have to enable it, please let us know on the
+ linux-***@vger.kernel.org mailing list, so we can
+ help you migrate to 4-addr AP/client (or, if it's really
+ necessary, give up on our plan of removing it).
+
source "drivers/net/wireless/admtek/Kconfig"
source "drivers/net/wireless/ath/Kconfig"
source "drivers/net/wireless/atmel/Kconfig"
diff --git a/drivers/net/wireless/ath/ath9k/init.c b/drivers/net/wireless/ath/ath9k/init.c
index cfa3fe82ade3..368d9b313823 100644
--- a/drivers/net/wireless/ath/ath9k/init.c
+++ b/drivers/net/wireless/ath/ath9k/init.c
@@ -734,9 +734,11 @@ static const struct ieee80211_iface_limit if_limits[] = {
BIT(NL80211_IFTYPE_P2P_GO) },
};

+#ifdef CONFIG_WIRELESS_WDS
static const struct ieee80211_iface_limit wds_limits[] = {
{ .max = 2048, .types = BIT(NL80211_IFTYPE_WDS) },
};
+#endif

#ifdef CONFIG_ATH9K_CHANNEL_CONTEXT

@@ -774,6 +776,7 @@ static const struct ieee80211_iface_combination if_comb[] = {
BIT(NL80211_CHAN_WIDTH_40),
#endif
},
+#ifdef CONFIG_WIRELESS_WDS
{
.limits = wds_limits,
.n_limits = ARRAY_SIZE(wds_limits),
@@ -781,6 +784,7 @@ static const struct ieee80211_iface_combination if_comb[] = {
.num_different_channels = 1,
.beacon_int_infra_match = true,
},
+#endif
};

#ifdef CONFIG_ATH9K_CHANNEL_CONTEXT
@@ -851,7 +855,9 @@ static void ath9k_set_hw_capab(struct ath_softc *sc, struct ieee80211_hw *hw)
BIT(NL80211_IFTYPE_STATION) |
BIT(NL80211_IFTYPE_ADHOC) |
BIT(NL80211_IFTYPE_MESH_POINT) |
+#ifdef CONFIG_WIRELESS_WDS
BIT(NL80211_IFTYPE_WDS) |
+#endif
BIT(NL80211_IFTYPE_OCB);

if (ath9k_is_chanctx_enabled())
diff --git a/drivers/net/wireless/broadcom/b43/main.c b/drivers/net/wireless/broadcom/b43/main.c
index 6e5d9095b195..52f3541ecbcf 100644
--- a/drivers/net/wireless/broadcom/b43/main.c
+++ b/drivers/net/wireless/broadcom/b43/main.c
@@ -5591,7 +5591,9 @@ static struct b43_wl *b43_wireless_init(struct b43_bus_dev *dev)
BIT(NL80211_IFTYPE_AP) |
BIT(NL80211_IFTYPE_MESH_POINT) |
BIT(NL80211_IFTYPE_STATION) |
+#ifdef CONFIG_WIRELESS_WDS
BIT(NL80211_IFTYPE_WDS) |
+#endif
BIT(NL80211_IFTYPE_ADHOC);

hw->wiphy->flags |= WIPHY_FLAG_IBSS_RSN;
diff --git a/drivers/net/wireless/broadcom/b43legacy/main.c b/drivers/net/wireless/broadcom/b43legacy/main.c
index 83770d2ea057..e97ab2b91663 100644
--- a/drivers/net/wireless/broadcom/b43legacy/main.c
+++ b/drivers/net/wireless/broadcom/b43legacy/main.c
@@ -3838,7 +3838,9 @@ static int b43legacy_wireless_init(struct ssb_device *dev)
hw->wiphy->interface_modes =
BIT(NL80211_IFTYPE_AP) |
BIT(NL80211_IFTYPE_STATION) |
+#ifdef CONFIG_WIRELESS_WDS
BIT(NL80211_IFTYPE_WDS) |
+#endif
BIT(NL80211_IFTYPE_ADHOC);
hw->queues = 1; /* FIXME: hardware has more queues */
hw->max_rates = 2;
diff --git a/drivers/net/wireless/ralink/rt2x00/rt2x00dev.c b/drivers/net/wireless/ralink/rt2x00/rt2x00dev.c
index 4e0c5653054b..236f790e097a 100644
--- a/drivers/net/wireless/ralink/rt2x00/rt2x00dev.c
+++ b/drivers/net/wireless/ralink/rt2x00/rt2x00dev.c
@@ -1362,11 +1362,13 @@ int rt2x00lib_probe_dev(struct rt2x00_dev *rt2x00dev)
if (rt2x00dev->bcn->limit > 0)
rt2x00dev->hw->wiphy->interface_modes |=
BIT(NL80211_IFTYPE_ADHOC) |
- BIT(NL80211_IFTYPE_AP) |
#ifdef CONFIG_MAC80211_MESH
BIT(NL80211_IFTYPE_MESH_POINT) |
#endif
- BIT(NL80211_IFTYPE_WDS);
+#ifdef CONFIG_WIRELESS_WDS
+ BIT(NL80211_IFTYPE_WDS) |
+#endif
+ BIT(NL80211_IFTYPE_AP);

rt2x00dev->hw->wiphy->flags |= WIPHY_FLAG_IBSS_RSN;

diff --git a/net/wireless/core.c b/net/wireless/core.c
index 8201e6d7449e..f433f15f9222 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -571,6 +571,11 @@ static int wiphy_verify_combinations(struct wiphy *wiphy)
return -EINVAL;
}

+#ifndef CONFIG_WIRELESS_WDS
+ if (WARN_ON(all_iftypes & BIT(NL80211_IFTYPE_WDS)))
+ return -EINVAL;
+#endif
+
/* You can't even choose that many! */
if (WARN_ON(cnt < c->max_interfaces))
return -EINVAL;
@@ -609,6 +614,11 @@ int wiphy_register(struct wiphy *wiphy)
!rdev->ops->add_nan_func || !rdev->ops->del_nan_func)))
return -EINVAL;

+#ifndef CONFIG_WIRELESS_WDS
+ if (WARN_ON(wiphy->interface_modes & BIT(NL80211_IFTYPE_WDS)))
+ return -EINVAL;
+#endif
+
/*
* if a wiphy has unsupported modes for regulatory channel enforcement,
* opt-out of enforcement checking