core-legacy/helpers/get_server_port.cc

#include <netdb.h>
#include <helpers.h>

int
helpers::get_server_port(int fd)
{
    if(fd == -1)
    {
        return -1;
    }
    struct sockaddr_in sin{};
    socklen_t addr_len = sizeof(sin);
    if(getsockname(fd, (struct sockaddr *)&sin, &addr_len) == 0)
    {
        return ntohs(sin.sin_port);
    }
    return -1;
}