core-legacy/helpers/send_udp_broadcast.cc

#include <netdb.h>
#include <arpa/inet.h>
#include <trantor/utils/Logger.h>
#include "config.h"
#include <helpers.h>
#include <unistd.h>

int
helpers::send_udp_broadcast(const char *addr, uint16_t port, const char* message)
{
    struct sockaddr_in their_addr{};
    int fd;

    if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) == -1)
    {
        LOG_ERROR << "Error creating socket";
        return -1;
    }

    int broadcast = 1;
    if (setsockopt(fd, SOL_SOCKET, SO_BROADCAST, &broadcast, sizeof broadcast) < 0)
    {
        LOG_ERROR << "Error setting broadcast";
        return -1;
    }

    memset(&their_addr, 0, sizeof(their_addr));
    their_addr.sin_family = AF_INET;
    their_addr.sin_port = htons(port);
    their_addr.sin_addr.s_addr = inet_addr(addr);

    if(sendto(fd, message, strlen(message), 0, (struct sockaddr *)&their_addr, sizeof(their_addr)) < 0)
    {
        LOG_ERROR << "Error sending broadcast " << errno << " " << strerror(errno);
        return -1;
    }
    close(fd);

    return 0;
}