[core] Rework mDNS responder to fix TXT records

arduino/libretuya/libraries/mDNS/LwIPmDNS.cpp

@@ -3,6 +3,7 @@
 #ifdef LT_HAS_LWIP2
 
 #include "mDNS.h"
+#include <vector>
 
 extern "C" {
 #include <lwip/apps/mdns.h>
@@ -11,59 +12,35 @@ extern "C" {
 
 static u8_t mdns_netif_client_id = 0; // TODO fix this
 
-struct mdns_domain {
+static std::vector<char *> services;
-	/* Encoded domain name */
+static std::vector<uint8_t> protos;
-	u8_t name[256];
+static std::vector<std::vector<char *>> records;
-	/* Total length of domain name, including zero */
-	u16_t length;
-	/* Set if compression of this domain is not allowed */
-	u8_t skip_compression;
-};
-
-/** Description of a service */
-struct mdns_service {
-	/** TXT record to answer with */
-	struct mdns_domain txtdata;
-	/** Name of service, like 'myweb' */
-	char name[MDNS_LABEL_MAXLEN + 1];
-	/** Type of service, like '_http' */
-	char service[MDNS_LABEL_MAXLEN + 1];
-	/** Callback function and userdata
-	 * to update txtdata buffer */
-	service_get_txt_fn_t txt_fn;
-	void *txt_userdata;
-	/** TTL in seconds of SRV/TXT replies */
-	u32_t dns_ttl;
-	/** Protocol, TCP or UDP */
-	u16_t proto;
-	/** Port of the service */
-	u16_t port;
-};
-
-/** Description of a host/netif */
-struct mdns_host {
-	/** Hostname */
-	char name[MDNS_LABEL_MAXLEN + 1];
-	/** Pointer to services */
-	struct mdns_service *services[MDNS_MAX_SERVICES];
-	/** TTL in seconds of A/AAAA/PTR replies */
-	u32_t dns_ttl;
-};
-
-static String mdnsInstanceName = "default_instance";
 
 mDNS::mDNS() {}
 
 mDNS::~mDNS() {}
 
+static void mdnsTxtCallback(struct mdns_service *service, void *userdata) {
+	size_t index = (size_t)userdata;
+	if (index >= records.size())
+		return;
+
+	for (const auto record : records[index]) {
+		err_t err = mdns_resp_add_service_txtitem(service, record, strlen(record));
+		if (err != ERR_OK)
+			return;
+	}
+}
+
+static void mdnsStatusCallback(struct netif *netif, uint8_t result) {}
+
 bool mDNS::begin(const char *hostname) {
+	mdns_resp_register_name_result_cb(mdnsStatusCallback);
 	mdns_resp_init();
 	struct netif *netif = netif_list;
 	uint8_t enabled		= 0;
 	while (netif != NULL) {
 		netif->flags |= NETIF_FLAG_IGMP;
-		// TODO: detect mdns_netif_client_id by checking netif_get_client_data()
-		// and finding the requested hostname in struct mdns_host
 		if (netif_is_up(netif) && mdns_resp_add_netif(netif, hostname, 255) == ERR_OK) {
 			enabled++;
 		}
@@ -81,72 +58,52 @@ void mDNS::end() {
 	}
 }
 
-void mDNS::setInstanceName(String name) {
+bool mDNS::addServiceImpl(const char *name, const char *service, uint8_t proto, uint16_t port) {
-	mdnsInstanceName = name;
+	bool added			= false;
-}
-
-bool mDNS::addService(char *service, char *proto, uint16_t port) {
-	char _service[strlen(service) + 2];
-	char _proto[strlen(proto) + 2];
-	_service[0] = '_';
-	_proto[0]	= '_';
-	// prepend names with _
-	strcpy(_service + 1, service + (service[0] == '_'));
-	strcpy(_proto + 1, proto + (proto[0] == '_'));
-
-	mdns_sd_proto protocol = DNSSD_PROTO_UDP;
-	if (strncmp(_proto + 1, "tcp", 3) == 0)
-		protocol = DNSSD_PROTO_TCP;
-
 	struct netif *netif = netif_list;
 	while (netif != NULL) {
 		if (netif_is_up(netif)) {
-			mdns_resp_add_service(netif, mdnsInstanceName.c_str(), _service, protocol, port, 255, NULL, NULL);
+			// register TXT callback;
+			// pass service index as userdata parameter
+			mdns_resp_add_service(
+				netif,
+				name,
+				service,
+				(mdns_sd_proto)proto,
+				port,
+				255,
+				mdnsTxtCallback,
+				(void *)services.size() // index of newly added service
+			);
+			added = true;
 		}
 		netif = netif->next;
 	}
+
+	if (!added)
+		return false;
+
+	// add the service to TXT record arrays
+	services.push_back(strdup(service));
+	protos.push_back(proto);
+	records.emplace_back();
+
+	return true;
 }
 
-bool mDNS::addServiceTxt(char *name, char *proto, char *key, char *value) {
+bool mDNS::addServiceTxtImpl(const char *service, uint8_t proto, const char *item) {
-	char _name[strlen(name) + 2];
+	int8_t index = -1;
-	char _proto[strlen(proto) + 2];
+	for (uint8_t i = 0; i < services.size(); i++) {
-	_name[0]  = '_';
+		// find a matching service
-	_proto[0] = '_';
+		if (strcmp(services[i], service) == 0 && protos[i] == proto) {
-	// prepend names with _
+			index = i;
-	strcpy(_name + 1, name + (name[0] == '_'));
+			break;
-	strcpy(_proto + 1, proto + (proto[0] == '_'));
-
-	mdns_sd_proto protocol = DNSSD_PROTO_UDP;
-	if (strncmp(_proto + 1, "tcp", 3) == 0)
-		protocol = DNSSD_PROTO_TCP;
-
-	struct netif *netif = netif_list;
-	struct mdns_host *mdns;
-	struct mdns_service *service;
-
-	uint8_t txt_len = strlen(key) + strlen(value) + 1;
-	char *txt		= (char *)malloc(txt_len + 1);
-	sprintf(txt, "%s=%s", key, value);
-
-	while (netif != NULL) {
-		if (netif_is_up(netif)) {
-			mdns = (struct mdns_host *)netif_get_client_data(netif, mdns_netif_client_id);
-
-			for (uint8_t i = 0; i < MDNS_MAX_SERVICES; i++) {
-				service = mdns->services[i];
-				if (service == NULL)
-					continue;
-				if (strcmp(service->service, _name) || service->proto != protocol)
-					continue;
-				if (mdns_resp_add_service_txtitem(service, txt, txt_len) != ERR_OK) {
-					free(txt);
-					return false;
-				}
-			}
 		}
-		netif = netif->next;
 	}
-	free(txt);
+	if (index == -1)
+		return false;
+
+	records[index].push_back(strdup(item));
 	return true;
 }
 

arduino/libretuya/libraries/mDNS/mDNS.cpp

@@ -0,0 +1,40 @@
+/* Copyright (c) Kuba Szczodrzyński 2022-08-26. */
+
+#include "mDNS.h"
+
+static char *ensureUnderscore(const char *value) {
+	uint8_t len	 = strlen(value) + 1;
+	char *result = (char *)malloc(len);
+	result[0]	 = '_';
+	strcpy(result + 1, value + (value[0] == '_'));
+	return result;
+}
+
+void mDNS::setInstanceName(const char *name) {
+	if (instanceName)
+		free(instanceName);
+	instanceName = strdup(name);
+}
+
+bool mDNS::addService(char *service, char *proto, uint16_t port) {
+	char *_service = ensureUnderscore(service);
+	uint8_t _proto = strncmp(proto + (proto[0] == '_'), "tcp", 3) == 0 ? MDNS_TCP : MDNS_UDP;
+
+	bool result = addServiceImpl(instanceName ? instanceName : "LT mDNS", _service, _proto, port);
+	free(_service);
+	return result;
+}
+
+bool mDNS::addServiceTxt(char *service, char *proto, char *key, char *value) {
+	char *_service = ensureUnderscore(service);
+	uint8_t _proto = strncmp(proto + (proto[0] == '_'), "tcp", 3) == 0 ? MDNS_TCP : MDNS_UDP;
+
+	uint8_t txt_len = strlen(key) + strlen(value) + 1;
+	char *txt		= (char *)malloc(txt_len + 1);
+	sprintf(txt, "%s=%s", key, value);
+
+	bool result = addServiceTxtImpl(_service, _proto, txt);
+	free(_service);
+	free(txt);
+	return result;
+}

arduino/libretuya/libraries/mDNS/mDNS.h

@@ -44,7 +44,16 @@ License (MIT license):
 #include <Arduino.h>
 #include <api/IPv6Address.h>
 
+#define MDNS_UDP 0
+#define MDNS_TCP 1
+
 class mDNS {
+  private:
+	bool addServiceImpl(const char *name, const char *service, uint8_t proto, uint16_t port);
+	bool addServiceTxtImpl(const char *service, uint8_t proto, const char *item);
+
+	char *instanceName = NULL;
+
   public:
 	mDNS();
 	~mDNS();
@@ -52,9 +61,9 @@ class mDNS {
 	bool begin(const char *hostname);
 	void end();
 
-	void setInstanceName(String name);
+	void setInstanceName(const char *name);
 	bool addService(char *service, char *proto, uint16_t port);
-	bool addServiceTxt(char *name, char *proto, char *key, char *value);
+	bool addServiceTxt(char *service, char *proto, char *key, char *value);
 	// void enableArduino(uint16_t port = 3232, bool auth = false);
 	// void disableArduino();
 	// void enableWorkstation(esp_interface_t interface = ESP_IF_WIFI_STA);
@@ -73,12 +82,12 @@ class mDNS {
 	String txt(int idx, int txtIdx);
 	String txtKey(int idx, int txtIdx);
 
-	void setInstanceName(const char *name) {
+	void setInstanceName(String name) {
-		setInstanceName(String(name));
+		setInstanceName(name.c_str());
 	}
 
 	void setInstanceName(char *name) {
-		setInstanceName(String(name));
+		setInstanceName((const char *)name);
 	}
 
 	bool addService(const char *service, const char *proto, uint16_t port) {
@@ -89,12 +98,12 @@ class mDNS {
 		return addService(service.c_str(), proto.c_str(), port);
 	}
 
-	void addServiceTxt(const char *name, const char *proto, const char *key, const char *value) {
+	void addServiceTxt(const char *service, const char *proto, const char *key, const char *value) {
-		addServiceTxt((char *)name, (char *)proto, (char *)key, (char *)value);
+		addServiceTxt((char *)service, (char *)proto, (char *)key, (char *)value);
 	}
 
-	void addServiceTxt(String name, String proto, String key, String value) {
+	void addServiceTxt(String service, String proto, String key, String value) {
-		addServiceTxt(name.c_str(), proto.c_str(), key.c_str(), value.c_str());
+		addServiceTxt(service.c_str(), proto.c_str(), key.c_str(), value.c_str());
 	}
 
 	IPAddress queryHost(const char *host, uint32_t timeout = 2000) {

builder/utils/env.py

@@ -47,6 +47,7 @@ def env_add_defaults(env, platform, board):
     # Default build options
     env.Prepend(
         CPPPATH=[
+            "$LT_DIR/platform/common/config",
             "$LT_DIR/platform/common/fixups",
             "$LT_DIR/platform/common/fixups/lib_inc",
             "$BOARD_DIR",

platform/beken-72xx/config/lwipopts.h

@@ -6,9 +6,10 @@
 
 #include <sys/time.h>
 
-#define LWIP_MDNS_RESPONDER		   1
+// mDNS support
+#undef MEMP_NUM_UDP_PCB
 #define LWIP_NUM_NETIF_CLIENT_DATA 1
-#define LWIP_SO_RCVBUF			   1 // for ioctl(FIONREAD)
+#define MEMP_NUM_UDP_PCB		   (MAX_SOCKETS_UDP + 2 + 1)
 
 #define ip_addr	  ip4_addr
 #define ip_addr_t ip4_addr_t

platform/common/config/lwipopts.h

@@ -0,0 +1,10 @@
+/* Copyright (c) Kuba Szczodrzyński 2022-08-26. */
+
+#define LWIP_TIMEVAL_PRIVATE 0
+#define LWIP_NETIF_HOSTNAME	 1 // to support hostname changing
+#define LWIP_SO_RCVBUF		 1 // for ioctl(FIONREAD)
+
+#define LWIP_MDNS_RESPONDER 1
+#define MDNS_MAX_SERVICES	10
+
+#include_next "lwipopts.h"

platform/realtek-amb/config/lwipopts.h

@@ -2,10 +2,6 @@
 
 #pragma once
 
-#define LWIP_TIMEVAL_PRIVATE 0
-#define LWIP_NETIF_HOSTNAME	 1 // to support hostname changing
-#define LWIP_SO_RCVBUF		 1 // for ioctl(FIONREAD)
-
 #include_next "lwipopts.h"
 
 #define ip_addr			  ip4_addr	 // LwIP 2.0.x compatibility