Method: Socket.udp_server_sockets

Defined in:
lib/socket.rb

.udp_server_sockets(host = nil, port) ⇒ Object

:call-seq:

Socket.udp_server_sockets([host, ] port)

Creates UDP/IP sockets for a UDP server.

If no block given, it returns an array of sockets.

If a block is given, the block is called with the sockets. The value of the block is returned. The sockets are closed when this method returns.

If port is zero, some port is chosen. But the chosen port is used for the all sockets.

# UDP/IP echo server
Socket.udp_server_sockets(0) {|sockets|
  p sockets.first.local_address.ip_port     #=> 32963
  Socket.udp_server_loop_on(sockets) {|msg, msg_src|
    msg_src.reply msg
  }
}


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# File 'lib/socket.rb', line 1303

def self.udp_server_sockets(host=nil, port)
  last_error = nil
  sockets = []

  ipv6_recvpktinfo = nil
  if defined? Socket::AncillaryData
    if defined? Socket::IPV6_RECVPKTINFO # RFC 3542
      ipv6_recvpktinfo = Socket::IPV6_RECVPKTINFO
    elsif defined? Socket::IPV6_PKTINFO # RFC 2292
      ipv6_recvpktinfo = Socket::IPV6_PKTINFO
    end
  end

  local_addrs = Socket.ip_address_list

  ip_list = []
  Addrinfo.foreach(host, port, nil, :DGRAM, nil, Socket::AI_PASSIVE) {|ai|
    if ai.ipv4? && ai.ip_address == "0.0.0.0"
      local_addrs.each {|a|
        next unless a.ipv4?
        ip_list << Addrinfo.new(a.to_sockaddr, :INET, :DGRAM, 0);
      }
    elsif ai.ipv6? && ai.ip_address == "::" && !ipv6_recvpktinfo
      local_addrs.each {|a|
        next unless a.ipv6?
        ip_list << Addrinfo.new(a.to_sockaddr, :INET6, :DGRAM, 0);
      }
    else
      ip_list << ai
    end
  }
  ip_list.uniq!(&:to_sockaddr)

  if port == 0
    sockets = ip_sockets_port0(ip_list, false)
  else
    ip_list.each {|ip|
      ai = Addrinfo.udp(ip.ip_address, port)
      begin
        s = ai.bind
      rescue SystemCallError
        last_error = $!
        next
      end
      sockets << s
    }
    if sockets.empty?
      raise last_error
    end
  end

  sockets.each {|s|
    ai = s.local_address
    if ipv6_recvpktinfo && ai.ipv6? && ai.ip_address == "::"
      s.setsockopt(:IPV6, ipv6_recvpktinfo, 1)
    end
  }

  if block_given?
    begin
      yield sockets
    ensure
      sockets.each(&:close) if sockets
    end
  else
    sockets
  end
end