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example: Add UDP multicast example

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Angus Gratton 2017-07-10 16:33:08 +08:00 committed by Angus Gratton
parent 04a2cefb26
commit 61d2069e1c
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11
examples/protocols/udp_multicast/Makefile Normal file
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#
# This is a project Makefile. It is assumed the directory this Makefile resides in is a
# project subdirectory.
#
PROJECT_NAME := udp-multicast
CFLAGS := -DCONFIG_MDNS
include $(IDF_PATH)/make/project.mk

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examples/protocols/udp_multicast/README.md Normal file
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# UDP Multicast Example
This example shows how to use the IPV4 & IPV6 UDP multicast features via the BSD-style sockets interface.
## Behaviour
The behaviour of the example is:
* Listens to specified multicast addresses (one IPV4 and/or one IPV6).
* Print any UDP packets received as ASCII text.
* If no packets are received it will periodicially (after 2.5 seconds) send its own plaintext packet(s) to the multicast address(es).
## Configuration
The "Example Configuration" menu "make menuconfig" allows you to configure the details of the example:
* WiFi SSD & Password
* IP Mode: IPV4 & IPV6 dual, IPV4 only, or IPv6 only.
* Multicast addresses for IPV4 and/or IPV6.
* Enable multicast socket loopback (ie should the socket receive its own multicast transmissions.)
* Change the interface to add the multicast group on (default interface, or WiFi STA interface.) Both methods are valid.
## Implementation Details
In IPV4 & IPV6 dual mode, an IPV6 socket is created and the "dual mode" options described in [RFC4038](https://tools.ietf.org/html/rfc4038) are used to bind it to the default address for both IPV4 & IPV6 and join both the configured IPV4 & IPV6 multicast groups. Otherwise, a single socket of the appropriate type is created.
The socket is always bound to the default address, so it will also receive unicast packets. If you only want to receive multicast packets for a particular address, `bind()` to that multicast address instead.
## Host Tools
There are many host-side tools which can be used to interact with the UDP multicast example. One command line tool is [socat](http://www.dest-unreach.org/socat/) which can send and receive many kinds of packets.
### Send IPV4 multicast via socat
```
echo "Hi there, IPv4!" | socat STDIO UDP4-DATAGRAM:232.10.11.12:3333,ip-multicast-if=(host_ip_addr)
```
Replace `232.10.11.12:3333` with the IPV4 multicast address and port, and `(host_ip_addr)` with the host's IP address (used to find the interface to send the multicast packet on.)
### Receive IPV4 multicast via socat
```
socat STDIO UDP4-RECVFROM:3333,ip-add-membership=232.10.11.12:(host_ip_addr)
```
Replace `:3333` and `232.10.11.12` with the port and IPV4 multicast address, respectively. Replace `(host_ip_addr)` with the host IP address, used to find the interface to listen on.
(The `,ip-add-membership=...` clause may not be necessary, depending on your network configuration.)
### Send IPV6 multicast via socat
```
echo "Hi there, IPV6!" | socat STDIO UDP6-DATAGRAM:[ff02::fc]:3333
```
Replace `[ff02::fc]:3333` with the IPV6 multicast address and port, respectively.
### Receive IPV6 multicast via socat
At time of writing this is not possible without patching socat. Use a different tool or programming language to receive IPV6 multicast packets.
## About Examples
See the README.md file in the upper level 'examples' directory for general information about examples.

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examples/protocols/udp_multicast/main/Kconfig.projbuild Normal file
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menu "Example Configuration"
config WIFI_SSID
string "WiFi SSID"
default "myssid"
help
SSID (network name) for the example to connect to.
config WIFI_PASSWORD
string "WiFi Password"
default "myssid"
help
WiFi password (WPA or WPA2) for the example to use.
Can be left blank if the network has no security set.
choice EXAMPLE_IP_MODE
prompt "Multicast IP type"
help
Example can multicast IPV4, IPV6, or both.
config EXAMPLE_IPV4_V6
bool "IPV4 & IPV6"
select EXAMPLE_IPV4
select EXAMPLE_IPV6
config EXAMPLE_IPV4_ONLY
bool "IPV4"
select EXAMPLE_IPV4
config EXAMPLE_IPV6_ONLY
bool "IPV6"
select EXAMPLE_IPV6
endchoice
config EXAMPLE_IPV4
bool
config EXAMPLE_IPV6
bool
config EXAMPLE_MULTICAST_IPV4_ADDR
string "Multicast IPV4 Address (send & receive)"
default "232.10.11.12"
depends on EXAMPLE_IPV4
help
IPV4 multicast address. Example will both send to and listen to this address.
config EXAMPLE_MULTICAST_IPV6_ADDR
string "Multicast IPV6 Address (send & receive)"
default "FF02::FC"
depends on EXAMPLE_IPV6
help
IPV6 multicast address. Example will both send to and listen to this address.
The default FF02::FC address is a link-local multicast address. Consult IPV6 specifications or documentation for information about meaning of different IPV6 multicast ranges.
config EXAMPLE_PORT
int "Multicast port (send & receive)"
range 0 65535
default 333
help
Multicast port the example will both send & receive UDP packets on.
config EXAMPLE_LOOPBACK
bool "Multicast loopback"
help
Enables IP_MULTICAST_LOOP/IPV6_MULTICAST_LOOP options, meaning
that packets transmitted from the device are also received by the
device itself.
config EXAMPLE_MULTICAST_TTL
int "Multicast packet TTL"
range 1 255
help
Sets TTL field of multicast packets. Separate from uni- & broadcast TTL.
choice EXAMPLE_MULTICAST_IF
prompt "Multicast Interface"
help
Multicast socket can bind to default interface, or all interfaces.
config EXAMPLE_MULTICAST_LISTEN_DEFAULT_IF
bool "Default interface"
config EXAMPLE_MULTICAST_LISTEN_STA_IF
bool "WiFi STA interface"
endchoice
endmenu

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examples/protocols/udp_multicast/main/component.mk Normal file
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#
# "main" pseudo-component makefile.
#
# (Uses default behaviour of compiling all source files in directory, adding 'include' to include path.)

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examples/protocols/udp_multicast/main/udp_multicast_example_main.c Normal file
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/* UDP MultiCast Send/Receive Example
This example code is in the Public Domain (or CC0 licensed, at your option.)
Unless required by applicable law or agreed to in writing, this
software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
CONDITIONS OF ANY KIND, either express or implied.
*/
#include <string.h>
#include <sys/param.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/event_groups.h"
#include "esp_system.h"
#include "esp_wifi.h"
#include "esp_event_loop.h"
#include "esp_log.h"
#include "nvs_flash.h"
#include "lwip/err.h"
#include "lwip/sockets.h"
#include "lwip/sys.h"
#include <lwip/netdb.h>
/* The examples use simple WiFi configuration that you can set via
'make menuconfig'.
If you'd rather not, just change the below entries to strings with
the config you want - ie #define EXAMPLE_WIFI_SSID "mywifissid"
*/
#define EXAMPLE_WIFI_SSID CONFIG_WIFI_SSID
#define EXAMPLE_WIFI_PASS CONFIG_WIFI_PASSWORD
#define UDP_PORT CONFIG_EXAMPLE_PORT
#define MULTICAST_LOOPBACK CONFIG_EXAMPLE_LOOPBACK
#define MULTICAST_TTL CONFIG_EXAMPLE_MULTICAST_TTL
#define MULTICAST_IPV4_ADDR CONFIG_EXAMPLE_MULTICAST_IPV4_ADDR
#define MULTICAST_IPV6_ADDR CONFIG_EXAMPLE_MULTICAST_IPV6_ADDR
#define LISTEN_DEFAULT_IF CONFIG_EXAMPLE_LISTEN_DEFAULT_IF
/* FreeRTOS event group to signal when we are connected & ready to make a request */
static EventGroupHandle_t wifi_event_group;
/* The event group allows multiple bits for each event,
we use two - one for IPv4 "got ip", and
one for IPv6 "got ip". */
const int IPV4_GOTIP_BIT = BIT0;
const int IPV6_GOTIP_BIT = BIT1;
static const char *TAG = "multicast";
#ifdef CONFIG_EXAMPLE_IPV4
static const char *V4TAG = "mcast-ipv4";
#endif
#ifdef CONFIG_EXAMPLE_IPV6
static const char *V6TAG = "mcast-ipv6";
#endif
static esp_err_t event_handler(void *ctx, system_event_t *event)
{
switch(event->event_id) {
case SYSTEM_EVENT_STA_START:
esp_wifi_connect();
break;
case SYSTEM_EVENT_STA_CONNECTED:
/* enable ipv6 */
tcpip_adapter_create_ip6_linklocal(TCPIP_ADAPTER_IF_STA);
break;
case SYSTEM_EVENT_STA_GOT_IP:
xEventGroupSetBits(wifi_event_group, IPV4_GOTIP_BIT);
break;
case SYSTEM_EVENT_STA_DISCONNECTED:
/* This is a workaround as ESP32 WiFi libs don't currently
auto-reassociate. */
esp_wifi_connect();
xEventGroupClearBits(wifi_event_group, IPV4_GOTIP_BIT);
xEventGroupClearBits(wifi_event_group, IPV6_GOTIP_BIT);
break;
case SYSTEM_EVENT_AP_STA_GOT_IP6:
xEventGroupSetBits(wifi_event_group, IPV6_GOTIP_BIT);
default:
break;
}
return ESP_OK;
}
static void initialise_wifi(void)
{
tcpip_adapter_init();
wifi_event_group = xEventGroupCreate();
ESP_ERROR_CHECK( esp_event_loop_init(event_handler, NULL) );
wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
ESP_ERROR_CHECK( esp_wifi_init(&cfg) );
ESP_ERROR_CHECK( esp_wifi_set_storage(WIFI_STORAGE_RAM) );
wifi_config_t wifi_config = {
.sta = {
.ssid = EXAMPLE_WIFI_SSID,
.password = EXAMPLE_WIFI_PASS,
},
};
ESP_LOGI(TAG, "Setting WiFi configuration SSID %s...", wifi_config.sta.ssid);
ESP_ERROR_CHECK( esp_wifi_set_mode(WIFI_MODE_STA) );
ESP_ERROR_CHECK( esp_wifi_set_config(ESP_IF_WIFI_STA, &wifi_config) );
ESP_ERROR_CHECK( esp_wifi_start() );
}
#ifdef CONFIG_EXAMPLE_IPV4
/* Add a socket, either IPV4-only or IPV6 dual mode, to the IPV4
multicast group */
static int socket_add_ipv4_multicast_group(int sock, bool assign_source_if)
{
struct ip_mreq imreq = { 0 };
struct in_addr iaddr = { 0 };
int err = 0;
// Configure source interface
#if USE_DEFAULT_IF
imreq.imr_interface.s_addr = IPADDR_ANY;
#else
tcpip_adapter_ip_info_t ip_info = { 0 };
err = tcpip_adapter_get_ip_info(TCPIP_ADAPTER_IF_STA, &ip_info);
if (err != ESP_OK) {
ESP_LOGE(V4TAG, "Failed to get IP address info. Error 0x%x", err);
goto err;
}
inet_addr_from_ipaddr(&iaddr, &ip_info.ip);
#endif
// Configure multicast address to listen to
err = inet_aton(MULTICAST_IPV4_ADDR, &imreq.imr_multiaddr.s_addr);
if (err != 1) {
ESP_LOGE(V4TAG, "Configured IPV4 multicast address '%s' is invalid.", MULTICAST_IPV4_ADDR);
goto err;
}
ESP_LOGI(TAG, "Configured IPV4 Multicast address %s", inet_ntoa(imreq.imr_multiaddr.s_addr));
if (!IP_MULTICAST(ntohl(imreq.imr_multiaddr.s_addr))) {
ESP_LOGW(V4TAG, "Configured IPV4 multicast address '%s' is not a valid multicast address. This will probably not work.", MULTICAST_IPV4_ADDR);
}
if (assign_source_if) {
// Assign the IPv4 multicast source interface, via its IP
// (only necessary if this socket is IPV4 only)
err = setsockopt(sock, IPPROTO_IP, IP_MULTICAST_IF, &iaddr,
sizeof(struct in_addr));
if (err < 0) {
ESP_LOGE(V4TAG, "Failed to set IP_MULTICAST_IF. Error %d", errno);
goto err;
}
}
err = setsockopt(sock, IPPROTO_IP, IP_ADD_MEMBERSHIP,
&imreq, sizeof(struct ip_mreq));
if (err < 0) {
ESP_LOGE(V4TAG, "Failed to set IP_ADD_MEMBERSHIP. Error %d", errno);
goto err;
}
err:
return err;
}
#endif /* CONFIG_EXAMPLE_IPV4 */
#ifdef CONFIG_EXAMPLE_IPV4_ONLY
static int create_multicast_ipv4_socket()
{
struct sockaddr_in saddr = { 0 };
int sock = -1;
int err = 0;
sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_IP);
if (sock < 0) {
ESP_LOGE(V4TAG, "Failed to create socket. Error %d", errno);
return -1;
}
// Bind the socket to any address
saddr.sin_family = PF_INET;
saddr.sin_port = htons(UDP_PORT);
saddr.sin_addr.s_addr = htonl(INADDR_ANY);
err = bind(sock, (struct sockaddr *)&saddr, sizeof(struct sockaddr_in));
if (err < 0) {
ESP_LOGE(V4TAG, "Failed to bind socket. Error %d", errno);
goto err;
}
// Assign multicast TTL (set separately from normal interface TTL)
uint8_t ttl = MULTICAST_TTL;
setsockopt(sock, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(uint8_t));
if (err < 0) {
ESP_LOGE(V4TAG, "Failed to set IP_MULTICAST_TTL. Error %d", errno);
goto err;
}
#if MULTICAST_LOOPBACK
// select whether multicast traffic should be received by this device, too
// (if setsockopt() is not called, the default is no)
uint8_t loopback_val = MULTICAST_LOOPBACK;
err = setsockopt(sock, IPPROTO_IP, IP_MULTICAST_LOOP,
&loopback_val, sizeof(uint8_t));
if (err < 0) {
ESP_LOGE(V4TAG, "Failed to set IP_MULTICAST_LOOP. Error %d", errno);
goto err;
}
#endif
// this is also a listening socket, so add it to the multicast
// group for listening...
err = socket_add_ipv4_multicast_group(sock, true);
if (err < 0) {
goto err;
}
// All set, socket is configured for sending and receiving
return sock;
err:
close(sock);
return -1;
}
#endif /* CONFIG_EXAMPLE_IPV4_ONLY */
#ifdef CONFIG_EXAMPLE_IPV6
static int create_multicast_ipv6_socket()
{
struct sockaddr_in6 saddr = { 0 };
struct in6_addr if_inaddr = { 0 };
struct ip6_addr if_ipaddr = { 0 };
struct ip6_mreq v6imreq = { 0 };
int sock = -1;
int err = 0;
sock = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IPV6);
if (sock < 0) {
ESP_LOGE(V6TAG, "Failed to create socket. Error %d", errno);
return -1;
}
// Bind the socket to any address
saddr.sin6_family = AF_INET6;
saddr.sin6_port = htons(UDP_PORT);
bzero(&saddr.sin6_addr.un, sizeof(saddr.sin6_addr.un));
err = bind(sock, (struct sockaddr *)&saddr, sizeof(struct sockaddr_in6));
if (err < 0) {
ESP_LOGE(V6TAG, "Failed to bind socket. Error %d", errno);
goto err;
}
// Selct the interface to use as multicast source for this socket.
#if USE_DEFAULT_IF
bzero(&if_inaddr.un, sizeof(if_inaddr.un));
#else
// Read interface adapter link-local address and use it
// to bind the multicast IF to this socket.
//
// (Note the interface may have other non-LL IPV6 addresses as well,
// but it doesn't matter in this context as the address is only
// used to identify the interface.)
err = tcpip_adapter_get_ip6_linklocal(TCPIP_ADAPTER_IF_STA, &if_ipaddr);
inet6_addr_from_ip6addr(&if_inaddr, &if_ipaddr);
if (err != ESP_OK) {
ESP_LOGE(V6TAG, "Failed to get IPV6 LL address. Error 0x%x", err);
goto err;
}
#endif
// Assign the multicast source interface, via its IP
err = setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_IF, &if_inaddr,
sizeof(struct in6_addr));
if (err < 0) {
ESP_LOGE(V6TAG, "Failed to set IPV6_MULTICAST_IF. Error %d", errno);
goto err;
}
// Assign multicast TTL (set separately from normal interface TTL)
uint8_t ttl = MULTICAST_TTL;
setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(uint8_t));
if (err < 0) {
ESP_LOGE(V6TAG, "Failed to set IPV6_MULTICAST_HOPS. Error %d", errno);
goto err;
}
#if MULTICAST_LOOPBACK
// select whether multicast traffic should be received by this device, too
// (if setsockopt() is not called, the default is no)
uint8_t loopback_val = MULTICAST_LOOPBACK;
err = setsockopt(sock, IPPROTO_IPV6, IPV6_MULTICAST_LOOP,
&loopback_val, sizeof(uint8_t));
if (err < 0) {
ESP_LOGE(V6TAG, "Failed to set IPV6_MULTICAST_LOOP. Error %d", errno);
goto err;
}
#endif
// this is also a listening socket, so add it to the multicast
// group for listening...
// Configure source interface
#if USE_DEFAULT_IF
v6imreq.imr_interface.s_addr = IPADDR_ANY;
#else
inet6_addr_from_ip6addr(&v6imreq.ipv6mr_interface, &if_ipaddr);
#endif
#ifdef CONFIG_EXAMPLE_IPV6
// Configure multicast address to listen to
err = inet6_aton(MULTICAST_IPV6_ADDR, &v6imreq.ipv6mr_multiaddr);
if (err != 1) {
ESP_LOGE(V6TAG, "Configured IPV6 multicast address '%s' is invalid.", MULTICAST_IPV6_ADDR);
goto err;
}
ESP_LOGI(TAG, "Configured IPV6 Multicast address %s", inet6_ntoa(v6imreq.ipv6mr_multiaddr));
ip6_addr_t multi_addr;
inet6_addr_to_ip6addr(&multi_addr, &v6imreq.ipv6mr_multiaddr);
if (!ip6_addr_ismulticast(&multi_addr)) {
ESP_LOGW(V6TAG, "Configured IPV6 multicast address '%s' is not a valid multicast address. This will probably not work.", MULTICAST_IPV6_ADDR);
}
err = setsockopt(sock, IPPROTO_IPV6, IPV6_ADD_MEMBERSHIP,
&v6imreq, sizeof(struct ip6_mreq));
if (err < 0) {
ESP_LOGE(V6TAG, "Failed to set IPV6_ADD_MEMBERSHIP. Error %d", errno);
goto err;
}
#endif
#if CONFIG_EXAMPLE_IPV4_V6
// Add the common IPV4 config options
err = socket_add_ipv4_multicast_group(sock, false);
if (err < 0) {
goto err;
}
#endif
#if CONFIG_EXAMPLE_IPV4_V6
int only = 0;
#else
int only = 1; /* IPV6-only socket */
#endif
err = setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &only, sizeof(int));
if (err < 0) {
ESP_LOGE(V6TAG, "Failed to set IPV6_V6ONLY. Error %d", errno);
goto err;
}
ESP_LOGI(TAG, "Socket set IPV6-only");
// All set, socket is configured for sending and receiving
return sock;
err:
close(sock);
return -1;
}
#endif
static void mcast_example_task(void *pvParameters)
{
while (1) {
/* Wait for all the IPs we care about to be set
*/
uint32_t bits = 0;
#ifdef CONFIG_EXAMPLE_IPV4
bits |= IPV4_GOTIP_BIT;
#endif
#ifdef CONFIG_EXAMPLE_IPV6
bits |= IPV6_GOTIP_BIT;
#endif
ESP_LOGI(TAG, "Waiting for AP connection...");
xEventGroupWaitBits(wifi_event_group, bits, false, true, portMAX_DELAY);
ESP_LOGI(TAG, "Connected to AP");
int sock;
#ifdef CONFIG_EXAMPLE_IPV4_ONLY
sock = create_multicast_ipv4_socket();
if (sock < 0) {
ESP_LOGE(TAG, "Failed to create IPv4 multicast socket");
}
#else
sock = create_multicast_ipv6_socket();
if (sock < 0) {
ESP_LOGE(TAG, "Failed to create IPv6 multicast socket");
}
#endif
if (sock < 0) {
// Nothing to do!
vTaskDelay(5 / portTICK_PERIOD_MS);
continue;
}
#ifdef CONFIG_EXAMPLE_IPV4
// set destination multicast addresses for sending from these sockets
struct sockaddr_in sdestv4 = {
.sin_family = PF_INET,
.sin_port = htons(UDP_PORT),
};
// We know this inet_aton will pass because we did it above already
inet_aton(MULTICAST_IPV4_ADDR, &sdestv4.sin_addr.s_addr);
#endif
#ifdef CONFIG_EXAMPLE_IPV6
struct sockaddr_in6 sdestv6 = {
.sin6_family = PF_INET6,
.sin6_port = htons(UDP_PORT),
};
// We know this inet_aton will pass because we did it above already
inet6_aton(MULTICAST_IPV6_ADDR, &sdestv6.sin6_addr);
#endif
// Loop waiting for UDP received, and sending UDP packets if we don't
// see any.
int err = 1;
while (err > 0) {
struct timeval tv = {
.tv_sec = 2,
.tv_usec = 0,
};
fd_set rfds;
FD_ZERO(&rfds);
FD_SET(sock, &rfds);
int s = lwip_select(sock + 1, &rfds, NULL, NULL, &tv);
if (s < 0) {
ESP_LOGE(TAG, "Select failed: errno %d", errno);
err = -1;
break;
}
else if (s > 0) {
if (FD_ISSET(sock, &rfds)) {
// Incoming datagram received
char recvbuf[48];
char raddr_name[32] = { 0 };
struct sockaddr_in6 raddr; // Large enough for both IPv4 or IPv6
socklen_t socklen = sizeof(raddr);
int len = recvfrom(sock, recvbuf, sizeof(recvbuf)-1, 0,
(struct sockaddr *)&raddr, &socklen);
if (len < 0) {
ESP_LOGE(TAG, "multicast recvfrom failed: errno %d", errno);
err = -1;
break;
}
// Get the sender's address as a string
#ifdef CONFIG_EXAMPLE_IPV4
if (raddr.sin6_family == PF_INET) {
inet_ntoa_r(((struct sockaddr_in *)&raddr)->sin_addr.s_addr,
raddr_name, sizeof(raddr_name)-1);
}
#endif
#ifdef CONFIG_EXAMPLE_IPV6
if (raddr.sin6_family == PF_INET6) {
inet6_ntoa_r(raddr.sin6_addr, raddr_name, sizeof(raddr_name)-1);
}
#endif
ESP_LOGI(TAG, "received %d bytes from %s:", len, raddr_name);
recvbuf[len] = 0; // Null-terminate whatever we received and treat like a string...
ESP_LOGI(TAG, "%s", recvbuf);
}
}
else { // s == 0
// Timeout passed with no incoming data, so send something!
static int send_count;
const char sendfmt[] = "Multicast #%d sent by ESP32\n";
char sendbuf[48];
char addrbuf[32] = { 0 };
int len = snprintf(sendbuf, sizeof(sendbuf), sendfmt, send_count++);
if (len > sizeof(sendbuf)) {
ESP_LOGE(TAG, "Overflowed multicast sendfmt buffer!!");
send_count = 0;
err = -1;
break;
}
struct addrinfo hints = {
.ai_flags = AI_PASSIVE,
.ai_socktype = SOCK_DGRAM,
};
struct addrinfo *res;
#ifdef CONFIG_EXAMPLE_IPV4 // Send an IPv4 multicast packet
#ifdef CONFIG_EXAMPLE_IPV4_ONLY
hints.ai_family = AF_INET; // For an IPv4 socket
#else
hints.ai_family = AF_INET6; // For an IPv4 socket with V4 mapped addresses
hints.ai_flags |= AI_V4MAPPED;
#endif
int err = getaddrinfo(CONFIG_EXAMPLE_MULTICAST_IPV4_ADDR,
NULL,
&hints,
&res);
if (err < 0) {
ESP_LOGE(TAG, "getaddrinfo() failed for IPV4 destination address. error: %d", err);
break;
}
#ifdef CONFIG_EXAMPLE_IPV4_ONLY
((struct sockaddr_in *)res->ai_addr)->sin_port = htons(UDP_PORT);
inet_ntoa_r(((struct sockaddr_in *)res->ai_addr)->sin_addr, addrbuf, sizeof(addrbuf)-1);
ESP_LOGI(TAG, "Sending to IPV4 multicast address %s...", addrbuf);
#else
((struct sockaddr_in6 *)res->ai_addr)->sin6_port = htons(UDP_PORT);
inet6_ntoa_r(((struct sockaddr_in6 *)res->ai_addr)->sin6_addr, addrbuf, sizeof(addrbuf)-1);
ESP_LOGI(TAG, "Sending to IPV6 (V4 mapped) multicast address %s (%s)...", addrbuf, CONFIG_EXAMPLE_MULTICAST_IPV4_ADDR);
#endif
err = sendto(sock, sendbuf, len, 0, res->ai_addr, res->ai_addrlen);
if (err < 0) {
ESP_LOGE(TAG, "IPV4 sendto failed. errno: %d", errno);
break;
}
#endif
#ifdef CONFIG_EXAMPLE_IPV6
hints.ai_family = AF_INET6;
hints.ai_protocol = 0;
err = getaddrinfo(CONFIG_EXAMPLE_MULTICAST_IPV6_ADDR,
NULL,
&hints,
&res);
if (err < 0) {
ESP_LOGE(TAG, "getaddrinfo() failed for IPV6 destination address. error: %d", err);
break;
}
struct sockaddr_in6 *s6addr = (struct sockaddr_in6 *)res->ai_addr;
s6addr->sin6_port = htons(UDP_PORT);
inet6_ntoa_r(s6addr->sin6_addr, addrbuf, sizeof(addrbuf)-1);
ESP_LOGI(TAG, "Sending to IPV6 multicast address %s...", addrbuf);
err = sendto(sock, sendbuf, len, 0, res->ai_addr, res->ai_addrlen);
if (err < 0) {
ESP_LOGE(TAG, "IPV6 sendto failed. errno: %d", errno);
break;
}
#endif
}
}
ESP_LOGE(TAG, "Shutting down socket and restarting...");
shutdown(sock, 0);
close(sock);
}
}
void app_main()
{
ESP_ERROR_CHECK( nvs_flash_init() );
initialise_wifi();
xTaskCreate(&mcast_example_task, "mcast_task", 4096, NULL, 5, NULL);
}