net: mdns: add capability of providing records in runtime (42e6c1fb) · Commits · Wenxi XU / zephyr

include/zephyr/net/dns_sd.h

+6 −8

Changes for include/zephyr/net/dns_sd.h: 6 added lines, 8 removed lines.
Original line number	Diff line number	Diff line
		@@ -198,8 +198,6 @@ extern "C" {
		/** Empty DNS-SD TXT specifier */
		#define DNS_SD_EMPTY_TXT dns_sd_empty_txt

		/** @cond INTERNAL_HIDDEN */

		/**
		* @brief DNS Service Discovery record
		*
		@@ -214,18 +212,16 @@ extern "C" {
		* Thus, it is possible for multiple services to advertise on a
		* particular port if they hard-code the port.
		*
		* @internal
		*
		* @see <a href="https://tools.ietf.org/html/rfc6763">RFC 6763</a>
		*/
		struct dns_sd_rec {
		/** <Instance> - e.g. "My HTTP Server" */
		/** "<Instance>" - e.g. "My HTTP Server" */
		const char *instance;
		/** Top half of the <Service> such as "_http" */
		/** Top half of the "<Service>" such as "_http" */
		const char *service;
		/** Bottom half of the <Service> "_tcp" or "_udp" */
		/** Bottom half of the "<Service>" "_tcp" or "_udp" */
		const char *proto;
		/** <Domain> such as "local" or "zephyrproject.org" */
		/** "<Domain>" such as "local" or "zephyrproject.org" */
		const char *domain;
		/** DNS TXT record */
		const char *text;
		@@ -235,6 +231,8 @@ struct dns_sd_rec {
		const uint16_t *port;
		};

		/** @cond INTERNAL_HIDDEN */

		/**
		* @brief Empty TXT specifier for DNS-SD
		*

include/zephyr/net/mdns_responder.h

0 → 100644

+34 −0

Changes for include/zephyr/net/mdns_responder.h: 34 added lines, 0 removed lines.
Original line number	Diff line number	Diff line
		/*
		* Copyright (c) 2023 Nordic Semiconductor ASA.
		*
		* SPDX-License-Identifier: Apache-2.0
		*/

		/** @file
		* @brief mDNS responder API
		*
		* This file contains the mDNS responder API. These APIs are used by the
		* to register mDNS records.
		*/

		#ifndef ZEPHYR_INCLUDE_NET_MDNS_RESPONDER_H_
		#define ZEPHYR_INCLUDE_NET_MDNS_RESPONDER_H_

		#include <stddef.h>
		#include <zephyr/net/dns_sd.h>

		/**
		* @brief Register continuous memory of @ref dns_sd_rec records.
		*
		* mDNS responder will start with iteration over mDNS records registered using
		* @ref DNS_SD_REGISTER_SERVICE (if any) and then go over external records.
		*
		* @param records A pointer to an array of mDNS records. It is stored internally
		* without copying the content so it must be kept valid. It can
		* be set to NULL, e.g. before freeing the memory block.
		* @param count The number of elements
		* @return 0 for OK; -EINVAL for invalid parameters.
		*/
		int mdns_responder_set_ext_records(const struct dns_sd_rec *records, size_t count);

		#endif /* ZEPHYR_INCLUDE_NET_MDNS_RESPONDER_H_ */

subsys/net/lib/dns/dns_sd.c

+1 −0

Changes for subsys/net/lib/dns/dns_sd.c: 1 added line, 0 removed lines.
Original line number	Diff line number	Diff line
		@@ -857,6 +857,7 @@ int dns_sd_handle_service_type_enum(const struct dns_sd_rec *inst,

		if (!port_in_use(proto, ntohs(*(inst->port)), addr4, addr6)) {
		/* Service is not yet bound, so do not advertise */
		NET_DBG("service not bound");
		return -EHOSTDOWN;
		}

subsys/net/lib/dns/dns_sd.h

+6 −0

Changes for subsys/net/lib/dns/dns_sd.h: 6 added lines, 0 removed lines.
Original line number	Diff line number	Diff line
		@@ -33,6 +33,12 @@ extern "C" {
		#define DNS_SD_FOREACH(it) \
		STRUCT_SECTION_FOREACH(dns_sd_rec, it)

		#define DNS_SD_COUNT(dst) \
		STRUCT_SECTION_COUNT(dns_sd_rec, dst)

		#define DNS_SD_GET(i, dst) \
		STRUCT_SECTION_GET(dns_sd_rec, i, dst)

		/**
		* @brief Extract labels from a DNS-SD PTR query
		*

subsys/net/lib/dns/mdns_responder.c

+34 −1

Changes for subsys/net/lib/dns/mdns_responder.c: 34 added lines, 1 removed line.
Original line number	Diff line number	Diff line
		@@ -52,6 +52,8 @@ static struct net_context *ipv6[MAX_IPV6_IFACE_COUNT];
		#endif

		static struct net_mgmt_event_callback mgmt_cb;
		static const struct dns_sd_rec *external_records;
		static size_t external_records_count;

		#define BUF_ALLOC_TIMEOUT K_MSEC(100)

		@@ -340,6 +342,7 @@ static void send_sd_response(struct net_context *ctx,
		struct net_buf *result)
		{
		int ret;
		const struct dns_sd_rec *record;
		/* filter must be zero-initialized for "wildcard" port */
		struct dns_sd_rec filter = {0};
		struct sockaddr dst;
		@@ -359,6 +362,8 @@ static void send_sd_response(struct net_context *ctx,
		ARRAY_SIZE(domain_buf),
		};
		size_t n = ARRAY_SIZE(label);
		size_t rec_num;
		size_t ext_rec_num = external_records_count;

		BUILD_ASSERT(ARRAY_SIZE(label) == ARRAY_SIZE(size), "");

		@@ -423,7 +428,21 @@ static void send_sd_response(struct net_context *ctx,
		service_type_enum = true;
		}

		DNS_SD_FOREACH(record) {
		DNS_SD_COUNT(&rec_num);

		while (rec_num > 0 \|\| ext_rec_num > 0) {
		/*
		* The loop will always iterate over all entries, it can be done
		* backwards for simplicity
		*/
		if (rec_num > 0) {
		DNS_SD_GET(rec_num - 1, &record);
		rec_num--;
		} else {
		record = &external_records[ext_rec_num - 1];
		ext_rec_num--;
		}

		/* Checks validity and then compare */
		if (dns_sd_rec_match(record, &filter)) {
		NET_DBG("matched query: %s.%s.%s.%s port: %u",
		@@ -760,6 +779,8 @@ ipv4_out:

		static int mdns_responder_init(void)
		{
		external_records = NULL;
		external_records_count = 0;

		net_mgmt_init_event_callback(&mgmt_cb, mdns_iface_event_handler,
		NET_EVENT_IF_UP);
		@@ -769,4 +790,16 @@ static int mdns_responder_init(void)
		return init_listener();
		}

		int mdns_responder_set_ext_records(const struct dns_sd_rec *records, size_t count)
		{
		if (records == NULL \|\| count == 0) {
		return -EINVAL;
		}

		external_records = records;
		external_records_count = count;

		return 0;
		}

		SYS_INIT(mdns_responder_init, APPLICATION, CONFIG_MDNS_RESPONDER_INIT_PRIO);

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