Tim Hardisty 30b1c024a1 apps/netutils: add mdns library support
This commit allows an external mDNS library to be included in NuttX.

It originates from here: <https://github.com/mjansson/mdns>

It is declared as being in the Public Domain as per <http://unlicense.org>

Signed-off-by: Tim Hardisty <timh@jti.uk.com>
2025-06-02 23:18:24 +08:00

183 lines
5.6 KiB
C

/****************************************************************************
* apps/netutils/mdns/mdnsd.c
*
* SPDX-License-Identifier: Apache-2.0
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <limits.h>
#include <semaphore.h>
#include <debug.h> /* For nerr, info */
#include "netutils/netlib.h"
#include "netutils/mdnsd.h"
#include <spawn.h>
/****************************************************************************
* Preprocessor Definitions
****************************************************************************/
/****************************************************************************
* Private Types
****************************************************************************/
/* This enumeration describes the state of the MDNSD daemon */
enum mdnsd_daemon_e
{
MDNSD_NOT_RUNNING = 0,
MDNSD_STARTING,
MDNSD_RUNNING,
MDNSD_STOP_REQUESTED,
};
struct mdnsd_config_s
{
pid_t pid; /* Task ID of the spawned MDNSD daemon */
enum mdnsd_daemon_e state; /* State of the daemon */
sem_t lock; /* Used to protect the whole structure */
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
/****************************************************************************
* Private Data
****************************************************************************/
struct mdnsd_config_s g_mdnsd_config =
{
-1,
MDNSD_NOT_RUNNING,
SEM_INITIALIZER(1),
};
/****************************************************************************
* Public Data
****************************************************************************/
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
int mdnsd_stop(void)
{
int ret;
sem_wait(&g_mdnsd_config.lock);
if (g_mdnsd_config.state == MDNSD_RUNNING)
{
g_mdnsd_config.state = MDNSD_STOP_REQUESTED;
do
{
ret = (kill(g_mdnsd_config.pid,
CONFIG_NETUTILS_MDNS_DAEMON_STOP_SIGNAL));
if (ret < 0)
{
nerr("ERROR: kill pid %d failed: %d\n",
g_mdnsd_config.pid, errno);
break;
}
}
while (g_mdnsd_config.state == MDNSD_STOP_REQUESTED);
}
g_mdnsd_config.state = MDNSD_NOT_RUNNING;
sem_post(&g_mdnsd_config.lock);
return OK;
}
int mdnsd_start(FAR char *service_name, FAR char *service_port)
{
int ret;
char hostname_buffer[HOST_NAME_MAX];
const char *hostname = "nuttx";
FAR char *argv[7];
/* Are we in a non-running state? */
sem_wait(&g_mdnsd_config.lock);
if (g_mdnsd_config.state == MDNSD_NOT_RUNNING)
{
g_mdnsd_config.state = MDNSD_STARTING;
/* Configure our mDNS service */
/* The mdns library function will check the hostname too, but this
* ensures the default is our, not the library author's, choice.
*/
if (gethostname(hostname_buffer, HOST_NAME_MAX) == 0)
{
if (strlen(hostname_buffer) != 0)
{
hostname = hostname_buffer;
}
}
argv[0] = "--service";
argv[1] = service_name;
argv[2] = "--hostname";
argv[3] = (char *)hostname;
argv[4] = "--port";
argv[5] = service_port;
argv[6] = NULL;
/* Spawn mdns app */
ret = posix_spawn(&g_mdnsd_config.pid, /* Returned Task ID */
"mdns", /* Task Path */
NULL, /* File actions */
NULL, /* Attributes */
argv, /* Arguments */
NULL); /* No */
if (ret < 0)
{
int errval = errno;
syslog(LOG_ERR, "Failed to spawn mdns daemon\n");
g_mdnsd_config.state = MDNSD_NOT_RUNNING;
return -errval;
}
ninfo("Started\n");
g_mdnsd_config.state = MDNSD_RUNNING;
}
sem_post(&g_mdnsd_config.lock);
return OK;
}