From 300b1220fab38600f102bb8cfcc59a29ce41b095 Mon Sep 17 00:00:00 2001
From: Felix Fietkau <nbd@nbd.name>
Date: Wed, 1 Sep 2021 19:00:41 +0200
Subject: [PATCH] wireless: improve reliability of proxyarp support

instead of relying on hostapd to manipulate bridge attributes (which can race
against netifd adding/removing of member ports), set the proxyarp related
attributes in netifd directly when bringing up the member port

Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
 device.h                   |  1 +
 scripts/netifd-wireless.sh |  4 ++--
 system-linux.c             | 11 +++++++++--
 wireless.c                 |  7 +++++++
 wireless.h                 |  1 +
 5 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/device.h b/device.h
index 88cce9a..0496e89 100644
--- a/device.h
+++ b/device.h
@@ -243,6 +243,7 @@ struct device {
 	bool default_config;
 	bool wireless;
 	bool wireless_ap;
+	bool wireless_proxyarp;
 	bool wireless_isolate;
 	bool bpdu_filter;
 
diff --git a/scripts/netifd-wireless.sh b/scripts/netifd-wireless.sh
index 5527791..80fbf75 100644
--- a/scripts/netifd-wireless.sh
+++ b/scripts/netifd-wireless.sh
@@ -294,10 +294,10 @@ _wireless_set_brsnoop_isolation() {
 	local multicast_to_unicast="$1"
 	local isolate
 
-	json_get_var isolate isolate
+	json_get_vars isolate proxy_arp
 
 	[ ${isolate:-0} -gt 0 -o -z "$network_bridge" ] && return
-	[ ${multicast_to_unicast:-1} -gt 0 ] && json_add_boolean isolate 1
+	[ ${multicast_to_unicast:-1} -gt 0 -o ${proxy_arp:-0} -gt 0 ] && json_add_boolean isolate 1
 }
 
 for_each_interface() {
diff --git a/system-linux.c b/system-linux.c
index 7c91008..6c6f1ec 100644
--- a/system-linux.c
+++ b/system-linux.c
@@ -464,6 +464,11 @@ static void system_bridge_set_hairpin_mode(struct device *dev, const char *val)
 	system_set_dev_sysfs("brport/hairpin_mode", dev->ifname, val);
 }
 
+static void system_bridge_set_proxyarp_wifi(struct device *dev, const char *val)
+{
+	system_set_dev_sysfs("brport/proxyarp_wifi", dev->ifname, val);
+}
+
 static void system_bridge_set_bpdu_filter(struct device *dev, const char *val)
 {
 	system_set_dev_sysfs("brport/bpdu_filter", dev->ifname, val);
@@ -870,17 +875,19 @@ static void
 system_bridge_set_wireless(struct device *bridge, struct device *dev)
 {
 	bool mcast_to_ucast = dev->wireless_ap;
-	bool hairpin = true;
+	bool hairpin;
 
 	if (bridge->settings.flags & DEV_OPT_MULTICAST_TO_UNICAST &&
 	    !bridge->settings.multicast_to_unicast)
 		mcast_to_ucast = false;
 
-	if (!mcast_to_ucast || dev->wireless_isolate)
+	hairpin = mcast_to_ucast || dev->wireless_proxyarp;
+	if (dev->wireless_isolate)
 		hairpin = false;
 
 	system_bridge_set_multicast_to_unicast(dev, mcast_to_ucast ? "1" : "0");
 	system_bridge_set_hairpin_mode(dev, hairpin ? "1" : "0");
+	system_bridge_set_proxyarp_wifi(dev, dev->wireless_proxyarp ? "1" : "0");
 }
 
 int system_bridge_addif(struct device *bridge, struct device *dev)
diff --git a/wireless.c b/wireless.c
index 61125a4..0e6447d 100644
--- a/wireless.c
+++ b/wireless.c
@@ -64,6 +64,7 @@ enum {
 	VIF_ATTR_NETWORK,
 	VIF_ATTR_ISOLATE,
 	VIF_ATTR_MODE,
+	VIF_ATTR_PROXYARP,
 	__VIF_ATTR_MAX,
 };
 
@@ -72,6 +73,7 @@ static const struct blobmsg_policy vif_policy[__VIF_ATTR_MAX] = {
 	[VIF_ATTR_NETWORK] = { .name = "network", .type = BLOBMSG_TYPE_ARRAY },
 	[VIF_ATTR_ISOLATE] = { .name = "isolate", .type = BLOBMSG_TYPE_BOOL },
 	[VIF_ATTR_MODE] = { .name = "mode", .type = BLOBMSG_TYPE_STRING },
+	[VIF_ATTR_PROXYARP] = { .name = "proxy_arp", .type = BLOBMSG_TYPE_BOOL },
 };
 
 static const struct uci_blob_param_list vif_param = {
@@ -330,6 +332,7 @@ static void wireless_interface_handle_link(struct wireless_interface *vif, const
 		struct device *dev = device_get(ifname, 2);
 		if (dev) {
 			dev->wireless_isolate = vif->isolate;
+			dev->wireless_proxyarp = vif->proxyarp;
 			dev->wireless = true;
 			dev->wireless_ap = vif->ap_mode;
 			dev->bpdu_filter = dev->wireless_ap && ifname == vif->ifname;
@@ -794,6 +797,10 @@ wireless_interface_init_config(struct wireless_interface *vif)
 	if (cur)
 		vif->isolate = blobmsg_get_bool(cur);
 
+	cur = tb[VIF_ATTR_PROXYARP];
+	if (cur)
+		vif->proxyarp = blobmsg_get_bool(cur);
+
 	cur = tb[VIF_ATTR_MODE];
 	if (cur)
 		vif->ap_mode = !strcmp(blobmsg_get_string(cur), "ap");
diff --git a/wireless.h b/wireless.h
index 5969218..7b87611 100644
--- a/wireless.h
+++ b/wireless.h
@@ -88,6 +88,7 @@ struct wireless_interface {
 
 	const char *ifname;
 	struct blob_attr *network;
+	bool proxyarp;
 	bool isolate;
 	bool ap_mode;
 };
-- 
2.30.2