From 50e16efd415132d2a7cee379f5183ddd907acfb2 Mon Sep 17 00:00:00 2001
From: Felix Fietkau <nbd@nbd.name>
Date: Fri, 15 Sep 2023 14:25:23 +0200
Subject: [PATCH] hostapd: support dynamic reload of vlan files when renaming
 interfaces

Avoids unnecessary AP restart on ifname changes when wifi-vlan sections
are present.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
 .../network/services/hostapd/files/hostapd.uc | 10 +--
 .../services/hostapd/src/src/ap/ucode.c       | 89 +++++++++++++++++++
 2 files changed, 94 insertions(+), 5 deletions(-)

diff --git a/package/network/services/hostapd/files/hostapd.uc b/package/network/services/hostapd/files/hostapd.uc
index 6b6e41b6f79..ebf732bea51 100644
--- a/package/network/services/hostapd/files/hostapd.uc
+++ b/package/network/services/hostapd/files/hostapd.uc
@@ -215,6 +215,7 @@ function bss_remove_file_fields(config)
 	for (let key in config.hash)
 		new_cfg.hash[key] = config.hash[key];
 	delete new_cfg.hash.wpa_psk_file;
+	delete new_cfg.hash.vlan_file;
 
 	return new_cfg;
 }
@@ -475,11 +476,12 @@ function iface_reload_config(phydev, config, old_config)
 		             bss_remove_file_fields(bss_list_cfg[i]))) {
 			hostapd.printf(`Update config data files for bss ${ifname}`);
 			if (bss.set_config(config_inline, i, true) < 0) {
-				hostapd.printf(`Failed to update config data files for bss ${ifname}`);
+				hostapd.printf(`Could not update config data files for bss ${ifname}`);
 				return false;
+			} else {
+				bss.ctrl("RELOAD_WPA_PSK");
+				continue;
 			}
-			bss.ctrl("RELOAD_WPA_PSK");
-			continue;
 		}
 
 		bss_reload_psk(bss, config.bss[i], bss_list_cfg[i]);
@@ -487,8 +489,6 @@ function iface_reload_config(phydev, config, old_config)
 			continue;
 
 		hostapd.printf(`Reload config for bss '${config.bss[0].ifname}' on phy '${phy}'`);
-		hostapd.printf(`old: ${bss_remove_file_fields(bss_list_cfg[i])}`);
-		hostapd.printf(`new: ${bss_remove_file_fields(config.bss[i])}`);
 		if (bss.set_config(config_inline, i) < 0) {
 			hostapd.printf(`Failed to set config for bss ${ifname}`);
 			return false;
diff --git a/package/network/services/hostapd/src/src/ap/ucode.c b/package/network/services/hostapd/src/src/ap/ucode.c
index 7bc797acfc6..e79f2420c07 100644
--- a/package/network/services/hostapd/src/src/ap/ucode.c
+++ b/package/network/services/hostapd/src/src/ap/ucode.c
@@ -111,6 +111,94 @@ uc_hostapd_remove_iface(uc_vm_t *vm, size_t nargs)
 	return NULL;
 }
 
+static struct hostapd_vlan *
+bss_conf_find_vlan(struct hostapd_bss_config *bss, int id)
+{
+	struct hostapd_vlan *vlan;
+
+	for (vlan = bss->vlan; vlan; vlan = vlan->next)
+		if (vlan->vlan_id == id)
+			return vlan;
+
+	return NULL;
+}
+
+static int
+bss_conf_rename_vlan(struct hostapd_data *hapd, struct hostapd_vlan *vlan,
+		     const char *ifname)
+{
+	if (!strcmp(ifname, vlan->ifname))
+		return 0;
+
+	hostapd_drv_if_rename(hapd, WPA_IF_AP_VLAN, vlan->ifname, ifname);
+	os_strlcpy(vlan->ifname, ifname, sizeof(vlan->ifname));
+
+	return 0;
+}
+
+static int
+bss_reload_vlans(struct hostapd_data *hapd, struct hostapd_bss_config *bss)
+{
+	struct hostapd_bss_config *old_bss = hapd->conf;
+	struct hostapd_vlan *vlan, *vlan_new, *wildcard;
+	char ifname[IFNAMSIZ + 1], vlan_ifname[IFNAMSIZ + 1], *pos;
+	int ret;
+
+	vlan = bss_conf_find_vlan(old_bss, VLAN_ID_WILDCARD);
+	wildcard = bss_conf_find_vlan(bss, VLAN_ID_WILDCARD);
+	if (!!vlan != !!wildcard)
+		return -1;
+
+	if (vlan && wildcard && strcmp(vlan->ifname, wildcard->ifname) != 0)
+		strcpy(vlan->ifname, wildcard->ifname);
+	else
+		wildcard = NULL;
+
+	for (vlan = bss->vlan; vlan; vlan = vlan->next) {
+		if (vlan->vlan_id == VLAN_ID_WILDCARD ||
+		    vlan->dynamic_vlan > 0)
+			continue;
+
+		if (!bss_conf_find_vlan(old_bss, vlan->vlan_id))
+			return -1;
+	}
+
+	for (vlan = old_bss->vlan; vlan; vlan = vlan->next) {
+		if (vlan->vlan_id == VLAN_ID_WILDCARD)
+			continue;
+
+		if (vlan->dynamic_vlan == 0) {
+			vlan_new = bss_conf_find_vlan(bss, vlan->vlan_id);
+			if (!vlan_new)
+				return -1;
+
+			if (bss_conf_rename_vlan(hapd, vlan, vlan_new->ifname))
+				return -1;
+
+			continue;
+		}
+
+		if (!wildcard)
+			continue;
+
+		os_strlcpy(ifname, wildcard->ifname, sizeof(ifname));
+		pos = os_strchr(ifname, '#');
+		if (!pos)
+			return -1;
+
+		*pos++ = '\0';
+		ret = os_snprintf(vlan_ifname, sizeof(vlan_ifname), "%s%d%s",
+				  ifname, vlan->vlan_id, pos);
+	        if (os_snprintf_error(sizeof(vlan_ifname), ret))
+			return -1;
+
+		if (bss_conf_rename_vlan(hapd, vlan, vlan_ifname))
+			return -1;
+	}
+
+	return 0;
+}
+
 static uc_value_t *
 uc_hostapd_bss_set_config(uc_vm_t *vm, size_t nargs)
 {
@@ -150,6 +238,7 @@ uc_hostapd_bss_set_config(uc_vm_t *vm, size_t nargs)
 	} while (0)
 
 		swap_field(ssid.wpa_psk_file);
+		ret = bss_reload_vlans(hapd, bss);
 		goto done;
 	}
 
-- 
2.30.2