hostapd: update mesh DFS patches and add mesh HE support

Drop outdated and by now broken patchset originally supplied by
Peter Oh in August 2018 but never merged upstream.
Instead add the more promissing rework recently submitted by
Markus Theil who picked up Peter's patchset, fixed and completed it
and added support for HE (802.11ax) in mesh mode.

This is only compile tested and needs some real-life testing.

Fixes: FS#3214
Fixes: 167028b750 ("hostapd: Update to version 2.9 (2019-08-08)")
Fixes: 0a3ec87a66 ("hostapd: update to latest Git hostap_2_9-1238-gdd2daf0848ed")
Fixes: 017320ead3 ("hostapd: bring back mesh patches")
Signed-off-by: Daniel Golle <daniel@makrotopia.org>

1 files changed, 81 insertions, 0 deletions

diff --git a/package/network/services/hostapd/patches/019-mesh-use-deterministic-channel-on-channel-switch.patch b/package/network/services/hostapd/patches/019-mesh-use-deterministic-channel-on-channel-switch.patch
new file mode 100644
index 0000000000..8e38a8e53c
--- /dev/null
+++ b/package/network/services/hostapd/patches/019-mesh-use-deterministic-channel-on-channel-switch.patch
@@ -0,0 +1,81 @@
+From fc8ea40f6130ac18d9c66797de2cf1d5af55d496 Mon Sep 17 00:00:00 2001
+From: Markus Theil <markus.theil@tu-ilmenau.de>
+Date: Tue, 30 Jun 2020 14:19:07 +0200
+Subject: [PATCH 19/19] mesh: use deterministic channel on channel switch
+
+This patch uses a deterministic channel on DFS channel switch
+in mesh networks. Otherwise, when switching to a usable but not
+available channel, no CSA can be sent and a random channel is choosen
+without notification of other nodes. It is then quite likely, that
+the mesh network gets disconnected.
+
+Fix this by using a deterministic number, based on the sha256 hash
+of the mesh ID, in order to use at least a different number in each
+mesh network.
+
+Signed-off-by: Markus Theil <markus.theil@tu-ilmenau.de>
+---
+ src/ap/dfs.c                 | 20 +++++++++++++++++++-
+ src/drivers/driver_nl80211.c |  4 ++++
+ 2 files changed, 23 insertions(+), 1 deletion(-)
+
+--- a/src/ap/dfs.c
++++ b/src/ap/dfs.c
+@@ -17,6 +17,7 @@
+ #include "ap_drv_ops.h"
+ #include "drivers/driver.h"
+ #include "dfs.h"
++#include "crypto/crypto.h"
+ 
+ 
+ static int dfs_get_used_n_chans(struct hostapd_iface *iface, int *seg1)
+@@ -480,9 +481,14 @@ dfs_get_valid_channel(struct hostapd_ifa
+ 	int num_available_chandefs;
+ 	int chan_idx, chan_idx2;
+ 	int sec_chan_idx_80p80 = -1;
++	bool is_mesh = false;
+ 	int i;
+ 	u32 _rand;
+ 
++#ifdef CONFIG_MESH
++	is_mesh = iface->mconf;
++#endif
++
+ 	wpa_printf(MSG_DEBUG, "DFS: Selecting random channel");
+ 	*secondary_channel = 0;
+ 	*oper_centr_freq_seg0_idx = 0;
+@@ -502,8 +508,20 @@ dfs_get_valid_channel(struct hostapd_ifa
+ 	if (num_available_chandefs == 0)
+ 		return NULL;
+ 
+-	if (os_get_random((u8 *) &_rand, sizeof(_rand)) < 0)
++	/* try to use deterministic channel in mesh, so that both sides
++	 * have a chance to switch to the same channel */
++	if (is_mesh) {
++#ifdef CONFIG_MESH
++		u64 hash[4];
++		const u8 *meshid[1] = { &iface->mconf->meshid[0] };
++		const size_t meshid_len = iface->mconf->meshid_len;
++
++		sha256_vector(1, meshid, &meshid_len, (u8 *)&hash[0]);
++		_rand = hash[0] + hash[1] + hash[2] + hash[3];
++#endif
++	} else if (os_get_random((u8 *) &_rand, sizeof(_rand)) < 0)
+ 		return NULL;
++
+ 	chan_idx = _rand % num_available_chandefs;
+ 	dfs_find_channel(iface, &chan, chan_idx, skip_radar);
+ 	if (!chan) {
+--- a/src/drivers/driver_nl80211.c
++++ b/src/drivers/driver_nl80211.c
+@@ -9473,6 +9473,10 @@ static int nl80211_switch_channel(void *
+ 	if (ret)
+ 		goto error;
+ 
++	if (drv->nlmode == NL80211_IFTYPE_MESH_POINT) {
++		nla_put_flag(msg, NL80211_ATTR_HANDLE_DFS);
++	}
++
+ 	/* beacon_csa params */
+ 	beacon_csa = nla_nest_start(msg, NL80211_ATTR_CSA_IES);
+ 	if (!beacon_csa)