#$@%#$%!

Ngiler SH3LL 360
: / opt / alt / ruby21 / lib64 / ruby / 2.1.0 /

Information Server
MySQL : OFF Perl : OFF CURL : ON WGET : OFF PKEXEC : OFF

Directive	Local Value
IP Address	162.0.209.101
System	Linux premium169.web-hosting.com 4.18.0-553.50.1.lve.el8.x86_64 #1 SMP Thu Apr 17 19:10:24 UTC 2025 x86_64
User	luxeelil
PHP Version	8.0.30
Software	LiteSpeed
Doc root	Writable

Edit File : socket.rb \| Size : 25.60 KB
require 'socket.so' class Addrinfo # creates an Addrinfo object from the arguments. # # The arguments are interpreted as similar to self. # # Addrinfo.tcp("0.0.0.0", 4649).family_addrinfo("www.ruby-lang.org", 80) # #=> #<Addrinfo: 221.186.184.68:80 TCP (www.ruby-lang.org:80)> # # Addrinfo.unix("/tmp/sock").family_addrinfo("/tmp/sock2") # #=> #<Addrinfo: /tmp/sock2 SOCK_STREAM> # def family_addrinfo(args) if args.empty? raise ArgumentError, "no address specified" elsif Addrinfo === args.first raise ArgumentError, "too many arguments" if args.length != 1 addrinfo = args.first if (self.pfamily != addrinfo.pfamily) \|\| (self.socktype != addrinfo.socktype) raise ArgumentError, "Addrinfo type mismatch" end addrinfo elsif self.ip? raise ArgumentError, "IP address needs host and port but #{args.length} arguments given" if args.length != 2 host, port = args Addrinfo.getaddrinfo(host, port, self.pfamily, self.socktype, self.protocol)[0] elsif self.unix? raise ArgumentError, "UNIX socket needs single path argument but #{args.length} arguments given" if args.length != 1 path, = args Addrinfo.unix(path) else raise ArgumentError, "unexpected family" end end # creates a new Socket connected to the address of +local_addrinfo+. # # If _local_addrinfo_ is nil, the address of the socket is not bound. # # The _timeout_ specify the seconds for timeout. # Errno::ETIMEDOUT is raised when timeout occur. # # If a block is given the created socket is yielded for each address. # def connect_internal(local_addrinfo, timeout=nil) # :yields: socket sock = Socket.new(self.pfamily, self.socktype, self.protocol) begin sock.ipv6only! if self.ipv6? sock.bind local_addrinfo if local_addrinfo if timeout begin sock.connect_nonblock(self) rescue IO::WaitWritable if !IO.select(nil, [sock], nil, timeout) raise Errno::ETIMEDOUT, 'user specified timeout' end begin sock.connect_nonblock(self) # check connection failure rescue Errno::EISCONN end end else sock.connect(self) end rescue Exception sock.close raise end if block_given? begin yield sock ensure sock.close if !sock.closed? end else sock end end private :connect_internal # :call-seq: # addrinfo.connect_from([local_addr_args], [opts]) {\|socket\| ... } # addrinfo.connect_from([local_addr_args], [opts]) # # creates a socket connected to the address of self. # # If one or more arguments given as _local_addr_args_, # it is used as the local address of the socket. # _local_addr_args_ is given for family_addrinfo to obtain actual address. # # If _local_addr_args_ is not given, the local address of the socket is not bound. # # The optional last argument _opts_ is options represented by a hash. # _opts_ may have following options: # # [:timeout] specify the timeout in seconds. # # If a block is given, it is called with the socket and the value of the block is returned. # The socket is returned otherwise. # # Addrinfo.tcp("www.ruby-lang.org", 80).connect_from("0.0.0.0", 4649) {\|s\| # s.print "GET / HTTP/1.0\r\nHost: www.ruby-lang.org\r\n\r\n" # puts s.read # } # # # Addrinfo object can be taken for the argument. # Addrinfo.tcp("www.ruby-lang.org", 80).connect_from(Addrinfo.tcp("0.0.0.0", 4649)) {\|s\| # s.print "GET / HTTP/1.0\r\nHost: www.ruby-lang.org\r\n\r\n" # puts s.read # } # def connect_from(args, &block) opts = Hash === args.last ? args.pop : {} local_addr_args = args connect_internal(family_addrinfo(local_addr_args), opts[:timeout], &block) end # :call-seq: # addrinfo.connect([opts]) {\|socket\| ... } # addrinfo.connect([opts]) # # creates a socket connected to the address of self. # # The optional argument _opts_ is options represented by a hash. # _opts_ may have following options: # # [:timeout] specify the timeout in seconds. # # If a block is given, it is called with the socket and the value of the block is returned. # The socket is returned otherwise. # # Addrinfo.tcp("www.ruby-lang.org", 80).connect {\|s\| # s.print "GET / HTTP/1.0\r\nHost: www.ruby-lang.org\r\n\r\n" # puts s.read # } # def connect(opts={}, &block) connect_internal(nil, opts[:timeout], &block) end # :call-seq: # addrinfo.connect_to([remote_addr_args], [opts]) {\|socket\| ... } # addrinfo.connect_to([remote_addr_args], [opts]) # # creates a socket connected to _remote_addr_args_ and bound to self. # # The optional last argument _opts_ is options represented by a hash. # _opts_ may have following options: # # [:timeout] specify the timeout in seconds. # # If a block is given, it is called with the socket and the value of the block is returned. # The socket is returned otherwise. # # Addrinfo.tcp("0.0.0.0", 4649).connect_to("www.ruby-lang.org", 80) {\|s\| # s.print "GET / HTTP/1.0\r\nHost: www.ruby-lang.org\r\n\r\n" # puts s.read # } # def connect_to(args, &block) opts = Hash === args.last ? args.pop : {} remote_addr_args = args remote_addrinfo = family_addrinfo(remote_addr_args) remote_addrinfo.send(:connect_internal, self, opts[:timeout], &block) end # creates a socket bound to self. # # If a block is given, it is called with the socket and the value of the block is returned. # The socket is returned otherwise. # # Addrinfo.udp("0.0.0.0", 9981).bind {\|s\| # s.local_address.connect {\|s\| s.send "hello", 0 } # p s.recv(10) #=> "hello" # } # def bind sock = Socket.new(self.pfamily, self.socktype, self.protocol) begin sock.ipv6only! if self.ipv6? sock.setsockopt(:SOCKET, :REUSEADDR, 1) sock.bind(self) rescue Exception sock.close raise end if block_given? begin yield sock ensure sock.close if !sock.closed? end else sock end end # creates a listening socket bound to self. def listen(backlog=Socket::SOMAXCONN) sock = Socket.new(self.pfamily, self.socktype, self.protocol) begin sock.ipv6only! if self.ipv6? sock.setsockopt(:SOCKET, :REUSEADDR, 1) sock.bind(self) sock.listen(backlog) rescue Exception sock.close raise end if block_given? begin yield sock ensure sock.close if !sock.closed? end else sock end end # iterates over the list of Addrinfo objects obtained by Addrinfo.getaddrinfo. # # Addrinfo.foreach(nil, 80) {\|x\| p x } # #=> #<Addrinfo: 127.0.0.1:80 TCP (:80)> # # #<Addrinfo: 127.0.0.1:80 UDP (:80)> # # #<Addrinfo: [::1]:80 TCP (:80)> # # #<Addrinfo: [::1]:80 UDP (:80)> # def self.foreach(nodename, service, family=nil, socktype=nil, protocol=nil, flags=nil, &block) Addrinfo.getaddrinfo(nodename, service, family, socktype, protocol, flags).each(&block) end end class BasicSocket < IO # Returns an address of the socket suitable for connect in the local machine. # # This method returns _self_.local_address, except following condition. # # - IPv4 unspecified address (0.0.0.0) is replaced by IPv4 loopback address (127.0.0.1). # - IPv6 unspecified address (::) is replaced by IPv6 loopback address (::1). # # If the local address is not suitable for connect, SocketError is raised. # IPv4 and IPv6 address which port is 0 is not suitable for connect. # Unix domain socket which has no path is not suitable for connect. # # Addrinfo.tcp("0.0.0.0", 0).listen {\|serv\| # p serv.connect_address #=> #<Addrinfo: 127.0.0.1:53660 TCP> # serv.connect_address.connect {\|c\| # s, _ = serv.accept # p [c, s] #=> [#<Socket:fd 4>, #<Socket:fd 6>] # } # } # def connect_address addr = local_address afamily = addr.afamily if afamily == Socket::AF_INET raise SocketError, "unbound IPv4 socket" if addr.ip_port == 0 if addr.ip_address == "0.0.0.0" addr = Addrinfo.new(["AF_INET", addr.ip_port, nil, "127.0.0.1"], addr.pfamily, addr.socktype, addr.protocol) end elsif defined?(Socket::AF_INET6) && afamily == Socket::AF_INET6 raise SocketError, "unbound IPv6 socket" if addr.ip_port == 0 if addr.ip_address == "::" addr = Addrinfo.new(["AF_INET6", addr.ip_port, nil, "::1"], addr.pfamily, addr.socktype, addr.protocol) elsif addr.ip_address == "0.0.0.0" # MacOS X 10.4 returns "a.b.c.d" for IPv4-mapped IPv6 address. addr = Addrinfo.new(["AF_INET6", addr.ip_port, nil, "::1"], addr.pfamily, addr.socktype, addr.protocol) elsif addr.ip_address == "::ffff:0.0.0.0" # MacOS X 10.6 returns "::ffff:a.b.c.d" for IPv4-mapped IPv6 address. addr = Addrinfo.new(["AF_INET6", addr.ip_port, nil, "::1"], addr.pfamily, addr.socktype, addr.protocol) end elsif defined?(Socket::AF_UNIX) && afamily == Socket::AF_UNIX raise SocketError, "unbound Unix socket" if addr.unix_path == "" end addr end end class Socket < BasicSocket # enable the socket option IPV6_V6ONLY if IPV6_V6ONLY is available. def ipv6only! if defined? Socket::IPV6_V6ONLY self.setsockopt(:IPV6, :V6ONLY, 1) end end # :call-seq: # Socket.tcp(host, port, local_host=nil, local_port=nil, [opts]) {\|socket\| ... } # Socket.tcp(host, port, local_host=nil, local_port=nil, [opts]) # # creates a new socket object connected to host:port using TCP/IP. # # If local_host:local_port is given, # the socket is bound to it. # # The optional last argument _opts_ is options represented by a hash. # _opts_ may have following options: # # [:connect_timeout] specify the timeout in seconds. # # If a block is given, the block is called with the socket. # The value of the block is returned. # The socket is closed when this method returns. # # If no block is given, the socket is returned. # # Socket.tcp("www.ruby-lang.org", 80) {\|sock\| # sock.print "GET / HTTP/1.0\r\nHost: www.ruby-lang.org\r\n\r\n" # sock.close_write # puts sock.read # } # def self.tcp(host, port, rest) # :yield: socket opts = Hash === rest.last ? rest.pop : {} raise ArgumentError, "wrong number of arguments (#{rest.length} for 2)" if 2 < rest.length local_host, local_port = rest last_error = nil ret = nil connect_timeout = opts[:connect_timeout] local_addr_list = nil if local_host != nil \|\| local_port != nil local_addr_list = Addrinfo.getaddrinfo(local_host, local_port, nil, :STREAM, nil) end Addrinfo.foreach(host, port, nil, :STREAM) {\|ai\| if local_addr_list local_addr = local_addr_list.find {\|local_ai\| local_ai.afamily == ai.afamily } next if !local_addr else local_addr = nil end begin sock = local_addr ? ai.connect_from(local_addr, :timeout => connect_timeout) : ai.connect(:timeout => connect_timeout) rescue SystemCallError last_error = $! next end ret = sock break } if !ret if last_error raise last_error else raise SocketError, "no appropriate local address" end end if block_given? begin yield ret ensure ret.close if !ret.closed? end else ret end end # :stopdoc: def self.ip_sockets_port0(ai_list, reuseaddr) sockets = [] begin sockets.clear port = nil ai_list.each {\|ai\| begin s = Socket.new(ai.pfamily, ai.socktype, ai.protocol) rescue SystemCallError next end sockets << s s.ipv6only! if ai.ipv6? if reuseaddr s.setsockopt(:SOCKET, :REUSEADDR, 1) end if !port s.bind(ai) port = s.local_address.ip_port else s.bind(ai.family_addrinfo(ai.ip_address, port)) end } rescue Errno::EADDRINUSE sockets.each {\|s\| s.close } retry rescue Exception sockets.each {\|s\| s.close } raise end sockets end class << self private :ip_sockets_port0 end def self.tcp_server_sockets_port0(host) ai_list = Addrinfo.getaddrinfo(host, 0, nil, :STREAM, nil, Socket::AI_PASSIVE) sockets = ip_sockets_port0(ai_list, true) begin sockets.each {\|s\| s.listen(Socket::SOMAXCONN) } rescue Exception sockets.each {\|s\| s.close } raise end sockets end class << self private :tcp_server_sockets_port0 end # :startdoc: # creates TCP/IP server sockets for _host_ and _port_. # _host_ is optional. # # If no block given, # it returns an array of listening sockets. # # If a block is given, the block is called with the sockets. # The value of the block is returned. # The socket is closed when this method returns. # # If _port_ is 0, actual port number is chosen dynamically. # However all sockets in the result has same port number. # # # tcp_server_sockets returns two sockets. # sockets = Socket.tcp_server_sockets(1296) # p sockets #=> [#<Socket:fd 3>, #<Socket:fd 4>] # # # The sockets contains IPv6 and IPv4 sockets. # sockets.each {\|s\| p s.local_address } # #=> #<Addrinfo: [::]:1296 TCP> # # #<Addrinfo: 0.0.0.0:1296 TCP> # # # IPv6 and IPv4 socket has same port number, 53114, even if it is chosen dynamically. # sockets = Socket.tcp_server_sockets(0) # sockets.each {\|s\| p s.local_address } # #=> #<Addrinfo: [::]:53114 TCP> # # #<Addrinfo: 0.0.0.0:53114 TCP> # # # The block is called with the sockets. # Socket.tcp_server_sockets(0) {\|sockets\| # p sockets #=> [#<Socket:fd 3>, #<Socket:fd 4>] # } # def self.tcp_server_sockets(host=nil, port) if port == 0 sockets = tcp_server_sockets_port0(host) else last_error = nil sockets = [] begin Addrinfo.foreach(host, port, nil, :STREAM, nil, Socket::AI_PASSIVE) {\|ai\| begin s = ai.listen rescue SystemCallError last_error = $! next end sockets << s } if sockets.empty? raise last_error end rescue Exception sockets.each {\|s\| s.close } raise end end if block_given? begin yield sockets ensure sockets.each {\|s\| s.close if !s.closed? } end else sockets end end # yield socket and client address for each a connection accepted via given sockets. # # The arguments are a list of sockets. # The individual argument should be a socket or an array of sockets. # # This method yields the block sequentially. # It means that the next connection is not accepted until the block returns. # So concurrent mechanism, thread for example, should be used to service multiple clients at a time. # def self.accept_loop(sockets) # :yield: socket, client_addrinfo sockets.flatten!(1) if sockets.empty? raise ArgumentError, "no sockets" end loop { readable, _, _ = IO.select(sockets) readable.each {\|r\| begin sock, addr = r.accept_nonblock rescue IO::WaitReadable next end yield sock, addr } } end # creates a TCP/IP server on _port_ and calls the block for each connection accepted. # The block is called with a socket and a client_address as an Addrinfo object. # # If _host_ is specified, it is used with _port_ to determine the server addresses. # # The socket is not* closed when the block returns. # So application should close it explicitly. # # This method calls the block sequentially. # It means that the next connection is not accepted until the block returns. # So concurrent mechanism, thread for example, should be used to service multiple clients at a time. # # Note that Addrinfo.getaddrinfo is used to determine the server socket addresses. # When Addrinfo.getaddrinfo returns two or more addresses, # IPv4 and IPv6 address for example, # all of them are used. # Socket.tcp_server_loop succeeds if one socket can be used at least. # # # Sequential echo server. # # It services only one client at a time. # Socket.tcp_server_loop(16807) {\|sock, client_addrinfo\| # begin # IO.copy_stream(sock, sock) # ensure # sock.close # end # } # # # Threaded echo server # # It services multiple clients at a time. # # Note that it may accept connections too much. # Socket.tcp_server_loop(16807) {\|sock, client_addrinfo\| # Thread.new { # begin # IO.copy_stream(sock, sock) # ensure # sock.close # end # } # } # def self.tcp_server_loop(host=nil, port, &b) # :yield: socket, client_addrinfo tcp_server_sockets(host, port) {\|sockets\| accept_loop(sockets, &b) } end # :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 # } # } # 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 if !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 if !a.ipv6? ip_list << Addrinfo.new(a.to_sockaddr, :INET6, :DGRAM, 0); } else ip_list << ai end } 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 {\|s\| s.close if !s.closed? } if sockets end else sockets end end # :call-seq: # Socket.udp_server_recv(sockets) {\|msg, msg_src\| ... } # # Receive UDP/IP packets from the given _sockets_. # For each packet received, the block is called. # # The block receives _msg_ and _msg_src_. # _msg_ is a string which is the payload of the received packet. # _msg_src_ is a Socket::UDPSource object which is used for reply. # # Socket.udp_server_loop can be implemented using this method as follows. # # udp_server_sockets(host, port) {\|sockets\| # loop { # readable, _, _ = IO.select(sockets) # udp_server_recv(readable) {\|msg, msg_src\| ... } # } # } # def self.udp_server_recv(sockets) sockets.each {\|r\| begin msg, sender_addrinfo, _, controls = r.recvmsg_nonblock rescue IO::WaitReadable next end ai = r.local_address if ai.ipv6? and pktinfo = controls.find {\|c\| c.cmsg_is?(:IPV6, :PKTINFO) } ai = Addrinfo.udp(pktinfo.ipv6_pktinfo_addr.ip_address, ai.ip_port) yield msg, UDPSource.new(sender_addrinfo, ai) {\|reply_msg\| r.sendmsg reply_msg, 0, sender_addrinfo, pktinfo } else yield msg, UDPSource.new(sender_addrinfo, ai) {\|reply_msg\| r.send reply_msg, 0, sender_addrinfo } end } end # :call-seq: # Socket.udp_server_loop_on(sockets) {\|msg, msg_src\| ... } # # Run UDP/IP server loop on the given sockets. # # The return value of Socket.udp_server_sockets is appropriate for the argument. # # It calls the block for each message received. # def self.udp_server_loop_on(sockets, &b) # :yield: msg, msg_src loop { readable, _, _ = IO.select(sockets) udp_server_recv(readable, &b) } end # :call-seq: # Socket.udp_server_loop(port) {\|msg, msg_src\| ... } # Socket.udp_server_loop(host, port) {\|msg, msg_src\| ... } # # creates a UDP/IP server on _port_ and calls the block for each message arrived. # The block is called with the message and its source information. # # This method allocates sockets internally using _port_. # If _host_ is specified, it is used conjunction with _port_ to determine the server addresses. # # The _msg_ is a string. # # The _msg_src_ is a Socket::UDPSource object. # It is used for reply. # # # UDP/IP echo server. # Socket.udp_server_loop(9261) {\|msg, msg_src\| # msg_src.reply msg # } # def self.udp_server_loop(host=nil, port, &b) # :yield: message, message_source udp_server_sockets(host, port) {\|sockets\| udp_server_loop_on(sockets, &b) } end # UDP/IP address information used by Socket.udp_server_loop. class UDPSource # +remote_address+ is an Addrinfo object. # # +local_address+ is an Addrinfo object. # # +reply_proc+ is a Proc used to send reply back to the source. def initialize(remote_address, local_address, &reply_proc) @remote_address = remote_address @local_address = local_address @reply_proc = reply_proc end # Address of the source attr_reader :remote_address # Local address attr_reader :local_address def inspect # :nodoc: "\#<#{self.class}: #{@remote_address.inspect_sockaddr} to #{@local_address.inspect_sockaddr}>" end # Sends the String +msg+ to the source def reply(msg) @reply_proc.call msg end end # creates a new socket connected to path using UNIX socket socket. # # If a block is given, the block is called with the socket. # The value of the block is returned. # The socket is closed when this method returns. # # If no block is given, the socket is returned. # # # talk to /tmp/sock socket. # Socket.unix("/tmp/sock") {\|sock\| # t = Thread.new { IO.copy_stream(sock, STDOUT) } # IO.copy_stream(STDIN, sock) # t.join # } # def self.unix(path) # :yield: socket addr = Addrinfo.unix(path) sock = addr.connect if block_given? begin yield sock ensure sock.close if !sock.closed? end else sock end end # creates a UNIX server socket on _path_ # # If no block given, it returns a listening socket. # # If a block is given, it is called with the socket and the block value is returned. # When the block exits, the socket is closed and the socket file is removed. # # socket = Socket.unix_server_socket("/tmp/s") # p socket #=> #<Socket:fd 3> # p socket.local_address #=> #<Addrinfo: /tmp/s SOCK_STREAM> # # Socket.unix_server_socket("/tmp/sock") {\|s\| # p s #=> #<Socket:fd 3> # p s.local_address #=> # #<Addrinfo: /tmp/sock SOCK_STREAM> # } # def self.unix_server_socket(path) if !unix_socket_abstract_name?(path) begin st = File.lstat(path) rescue Errno::ENOENT end if st && st.socket? && st.owned? File.unlink path end end s = Addrinfo.unix(path).listen if block_given? begin yield s ensure s.close if !s.closed? if !unix_socket_abstract_name?(path) File.unlink path end end else s end end class << self private def unix_socket_abstract_name?(path) /linux/ =~ RUBY_PLATFORM && /\A(\0\|\z)/ =~ path end end # creates a UNIX socket server on _path_. # It calls the block for each socket accepted. # # If _host_ is specified, it is used with _port_ to determine the server ports. # # The socket is not* closed when the block returns. # So application should close it. # # This method deletes the socket file pointed by _path_ at first if # the file is a socket file and it is owned by the user of the application. # This is safe only if the directory of _path_ is not changed by a malicious user. # So don't use /tmp/malicious-users-directory/socket. # Note that /tmp/socket and /tmp/your-private-directory/socket is safe assuming that /tmp has sticky bit. # # # Sequential echo server. # # It services only one client at a time. # Socket.unix_server_loop("/tmp/sock") {\|sock, client_addrinfo\| # begin # IO.copy_stream(sock, sock) # ensure # sock.close # end # } # def self.unix_server_loop(path, &b) # :yield: socket, client_addrinfo unix_server_socket(path) {\|serv\| accept_loop(serv, &b) } end end Back

Edit File : socket.rb | Size : 25.60 KB

require 'socket.so'

class Addrinfo
  # creates an Addrinfo object from the arguments.
  #
  # The arguments are interpreted as similar to self.
  #
  #   Addrinfo.tcp("0.0.0.0", 4649).family_addrinfo("www.ruby-lang.org", 80)
  #   #=> #<Addrinfo: 221.186.184.68:80 TCP (www.ruby-lang.org:80)>
  #
  #   Addrinfo.unix("/tmp/sock").family_addrinfo("/tmp/sock2")
  #   #=> #<Addrinfo: /tmp/sock2 SOCK_STREAM>
  #
  def family_addrinfo(*args)
    if args.empty?
      raise ArgumentError, "no address specified"
    elsif Addrinfo === args.first
      raise ArgumentError, "too many arguments" if args.length != 1
      addrinfo = args.first
      if (self.pfamily != addrinfo.pfamily) ||
         (self.socktype != addrinfo.socktype)
        raise ArgumentError, "Addrinfo type mismatch"
      end
      addrinfo
    elsif self.ip?
      raise ArgumentError, "IP address needs host and port but #{args.length} arguments given" if args.length != 2
      host, port = args
      Addrinfo.getaddrinfo(host, port, self.pfamily, self.socktype, self.protocol)[0]
    elsif self.unix?
      raise ArgumentError, "UNIX socket needs single path argument but #{args.length} arguments given" if args.length != 1
      path, = args
      Addrinfo.unix(path)
    else
      raise ArgumentError, "unexpected family"
    end
  end

# creates a new Socket connected to the address of +local_addrinfo+.
  #
  # If _local_addrinfo_ is nil, the address of the socket is not bound.
  #
  # The _timeout_ specify the seconds for timeout.
  # Errno::ETIMEDOUT is raised when timeout occur.
  #
  # If a block is given the created socket is yielded for each address.
  #
  def connect_internal(local_addrinfo, timeout=nil) # :yields: socket
    sock = Socket.new(self.pfamily, self.socktype, self.protocol)
    begin
      sock.ipv6only! if self.ipv6?
      sock.bind local_addrinfo if local_addrinfo
      if timeout
        begin
          sock.connect_nonblock(self)
        rescue IO::WaitWritable
          if !IO.select(nil, [sock], nil, timeout)
            raise Errno::ETIMEDOUT, 'user specified timeout'
          end
          begin
            sock.connect_nonblock(self) # check connection failure
          rescue Errno::EISCONN
          end
        end
      else
        sock.connect(self)
      end
    rescue Exception
      sock.close
      raise
    end
    if block_given?
      begin
        yield sock
      ensure
        sock.close if !sock.closed?
      end
    else
      sock
    end
  end
  private :connect_internal

# :call-seq:
  #   addrinfo.connect_from([local_addr_args], [opts]) {|socket| ... }
  #   addrinfo.connect_from([local_addr_args], [opts])
  #
  # creates a socket connected to the address of self.
  #
  # If one or more arguments given as _local_addr_args_,
  # it is used as the local address of the socket.
  # _local_addr_args_ is given for family_addrinfo to obtain actual address.
  #
  # If _local_addr_args_ is not given, the local address of the socket is not bound.
  #
  # The optional last argument _opts_ is options represented by a hash.
  # _opts_ may have following options:
  #
  # [:timeout] specify the timeout in seconds.
  #
  # If a block is given, it is called with the socket and the value of the block is returned.
  # The socket is returned otherwise.
  #
  #   Addrinfo.tcp("www.ruby-lang.org", 80).connect_from("0.0.0.0", 4649) {|s|
  #     s.print "GET / HTTP/1.0\r\nHost: www.ruby-lang.org\r\n\r\n"
  #     puts s.read
  #   }
  #
  #   # Addrinfo object can be taken for the argument.
  #   Addrinfo.tcp("www.ruby-lang.org", 80).connect_from(Addrinfo.tcp("0.0.0.0", 4649)) {|s|
  #     s.print "GET / HTTP/1.0\r\nHost: www.ruby-lang.org\r\n\r\n"
  #     puts s.read
  #   }
  #
  def connect_from(*args, &block)
    opts = Hash === args.last ? args.pop : {}
    local_addr_args = args
    connect_internal(family_addrinfo(*local_addr_args), opts[:timeout], &block)
  end

# :call-seq:
  #   addrinfo.connect([opts]) {|socket| ... }
  #   addrinfo.connect([opts])
  #
  # creates a socket connected to the address of self.
  #
  # The optional argument _opts_ is options represented by a hash.
  # _opts_ may have following options:
  #
  # [:timeout] specify the timeout in seconds.
  #
  # If a block is given, it is called with the socket and the value of the block is returned.
  # The socket is returned otherwise.
  #
  #   Addrinfo.tcp("www.ruby-lang.org", 80).connect {|s|
  #     s.print "GET / HTTP/1.0\r\nHost: www.ruby-lang.org\r\n\r\n"
  #     puts s.read
  #   }
  #
  def connect(opts={}, &block)
    connect_internal(nil, opts[:timeout], &block)
  end

# :call-seq:
  #   addrinfo.connect_to([remote_addr_args], [opts]) {|socket| ... }
  #   addrinfo.connect_to([remote_addr_args], [opts])
  #
  # creates a socket connected to _remote_addr_args_ and bound to self.
  #
  # The optional last argument _opts_ is options represented by a hash.
  # _opts_ may have following options:
  #
  # [:timeout] specify the timeout in seconds.
  #
  # If a block is given, it is called with the socket and the value of the block is returned.
  # The socket is returned otherwise.
  #
  #   Addrinfo.tcp("0.0.0.0", 4649).connect_to("www.ruby-lang.org", 80) {|s|
  #     s.print "GET / HTTP/1.0\r\nHost: www.ruby-lang.org\r\n\r\n"
  #     puts s.read
  #   }
  #
  def connect_to(*args, &block)
    opts = Hash === args.last ? args.pop : {}
    remote_addr_args = args
    remote_addrinfo = family_addrinfo(*remote_addr_args)
    remote_addrinfo.send(:connect_internal, self, opts[:timeout], &block)
  end

# creates a socket bound to self.
  #
  # If a block is given, it is called with the socket and the value of the block is returned.
  # The socket is returned otherwise.
  #
  #   Addrinfo.udp("0.0.0.0", 9981).bind {|s|
  #     s.local_address.connect {|s| s.send "hello", 0 }
  #     p s.recv(10) #=> "hello"
  #   }
  #
  def bind
    sock = Socket.new(self.pfamily, self.socktype, self.protocol)
    begin
      sock.ipv6only! if self.ipv6?
      sock.setsockopt(:SOCKET, :REUSEADDR, 1)
      sock.bind(self)
    rescue Exception
      sock.close
      raise
    end
    if block_given?
      begin
        yield sock
      ensure
        sock.close if !sock.closed?
      end
    else
      sock
    end
  end

# creates a listening socket bound to self.
  def listen(backlog=Socket::SOMAXCONN)
    sock = Socket.new(self.pfamily, self.socktype, self.protocol)
    begin
      sock.ipv6only! if self.ipv6?
      sock.setsockopt(:SOCKET, :REUSEADDR, 1)
      sock.bind(self)
      sock.listen(backlog)
    rescue Exception
      sock.close
      raise
    end
    if block_given?
      begin
        yield sock
      ensure
        sock.close if !sock.closed?
      end
    else
      sock
    end
  end

# iterates over the list of Addrinfo objects obtained by Addrinfo.getaddrinfo.
  #
  #   Addrinfo.foreach(nil, 80) {|x| p x }
  #   #=> #<Addrinfo: 127.0.0.1:80 TCP (:80)>
  #   #   #<Addrinfo: 127.0.0.1:80 UDP (:80)>
  #   #   #<Addrinfo: [::1]:80 TCP (:80)>
  #   #   #<Addrinfo: [::1]:80 UDP (:80)>
  #
  def self.foreach(nodename, service, family=nil, socktype=nil, protocol=nil, flags=nil, &block)
    Addrinfo.getaddrinfo(nodename, service, family, socktype, protocol, flags).each(&block)
  end
end

class BasicSocket < IO
  # Returns an address of the socket suitable for connect in the local machine.
  #
  # This method returns _self_.local_address, except following condition.
  #
  # - IPv4 unspecified address (0.0.0.0) is replaced by IPv4 loopback address (127.0.0.1).
  # - IPv6 unspecified address (::) is replaced by IPv6 loopback address (::1).
  #
  # If the local address is not suitable for connect, SocketError is raised.
  # IPv4 and IPv6 address which port is 0 is not suitable for connect.
  # Unix domain socket which has no path is not suitable for connect.
  #
  #   Addrinfo.tcp("0.0.0.0", 0).listen {|serv|
  #     p serv.connect_address #=> #<Addrinfo: 127.0.0.1:53660 TCP>
  #     serv.connect_address.connect {|c|
  #       s, _ = serv.accept
  #       p [c, s] #=> [#<Socket:fd 4>, #<Socket:fd 6>]
  #     }
  #   }
  #
  def connect_address
    addr = local_address
    afamily = addr.afamily
    if afamily == Socket::AF_INET
      raise SocketError, "unbound IPv4 socket" if addr.ip_port == 0
      if addr.ip_address == "0.0.0.0"
        addr = Addrinfo.new(["AF_INET", addr.ip_port, nil, "127.0.0.1"], addr.pfamily, addr.socktype, addr.protocol)
      end
    elsif defined?(Socket::AF_INET6) && afamily == Socket::AF_INET6
      raise SocketError, "unbound IPv6 socket" if addr.ip_port == 0
      if addr.ip_address == "::"
        addr = Addrinfo.new(["AF_INET6", addr.ip_port, nil, "::1"], addr.pfamily, addr.socktype, addr.protocol)
      elsif addr.ip_address == "0.0.0.0" # MacOS X 10.4 returns "a.b.c.d" for IPv4-mapped IPv6 address.
        addr = Addrinfo.new(["AF_INET6", addr.ip_port, nil, "::1"], addr.pfamily, addr.socktype, addr.protocol)
      elsif addr.ip_address == "::ffff:0.0.0.0" # MacOS X 10.6 returns "::ffff:a.b.c.d" for IPv4-mapped IPv6 address.
        addr = Addrinfo.new(["AF_INET6", addr.ip_port, nil, "::1"], addr.pfamily, addr.socktype, addr.protocol)
      end
    elsif defined?(Socket::AF_UNIX) && afamily == Socket::AF_UNIX
      raise SocketError, "unbound Unix socket" if addr.unix_path == ""
    end
    addr
  end
end

class Socket < BasicSocket
  # enable the socket option IPV6_V6ONLY if IPV6_V6ONLY is available.
  def ipv6only!
    if defined? Socket::IPV6_V6ONLY
      self.setsockopt(:IPV6, :V6ONLY, 1)
    end
  end

# :call-seq:
  #   Socket.tcp(host, port, local_host=nil, local_port=nil, [opts]) {|socket| ... }
  #   Socket.tcp(host, port, local_host=nil, local_port=nil, [opts])
  #
  # creates a new socket object connected to host:port using TCP/IP.
  #
  # If local_host:local_port is given,
  # the socket is bound to it.
  #
  # The optional last argument _opts_ is options represented by a hash.
  # _opts_ may have following options:
  #
  # [:connect_timeout] specify the timeout in seconds.
  #
  # If a block is given, the block is called with the socket.
  # The value of the block is returned.
  # The socket is closed when this method returns.
  #
  # If no block is given, the socket is returned.
  #
  #   Socket.tcp("www.ruby-lang.org", 80) {|sock|
  #     sock.print "GET / HTTP/1.0\r\nHost: www.ruby-lang.org\r\n\r\n"
  #     sock.close_write
  #     puts sock.read
  #   }
  #
  def self.tcp(host, port, *rest) # :yield: socket
    opts = Hash === rest.last ? rest.pop : {}
    raise ArgumentError, "wrong number of arguments (#{rest.length} for 2)" if 2 < rest.length
    local_host, local_port = rest
    last_error = nil
    ret = nil

connect_timeout = opts[:connect_timeout]

local_addr_list = nil
    if local_host != nil || local_port != nil
      local_addr_list = Addrinfo.getaddrinfo(local_host, local_port, nil, :STREAM, nil)
    end

Addrinfo.foreach(host, port, nil, :STREAM) {|ai|
      if local_addr_list
        local_addr = local_addr_list.find {|local_ai| local_ai.afamily == ai.afamily }
        next if !local_addr
      else
        local_addr = nil
      end
      begin
        sock = local_addr ?
          ai.connect_from(local_addr, :timeout => connect_timeout) :
          ai.connect(:timeout => connect_timeout)
      rescue SystemCallError
        last_error = $!
        next
      end
      ret = sock
      break
    }
    if !ret
      if last_error
        raise last_error
      else
        raise SocketError, "no appropriate local address"
      end
    end
    if block_given?
      begin
        yield ret
      ensure
        ret.close if !ret.closed?
      end
    else
      ret
    end
  end

# :stopdoc:
  def self.ip_sockets_port0(ai_list, reuseaddr)
    sockets = []
    begin
      sockets.clear
      port = nil
      ai_list.each {|ai|
        begin
          s = Socket.new(ai.pfamily, ai.socktype, ai.protocol)
        rescue SystemCallError
          next
        end
        sockets << s
        s.ipv6only! if ai.ipv6?
        if reuseaddr
          s.setsockopt(:SOCKET, :REUSEADDR, 1)
        end
        if !port
          s.bind(ai)
          port = s.local_address.ip_port
        else
          s.bind(ai.family_addrinfo(ai.ip_address, port))
        end
      }
    rescue Errno::EADDRINUSE
      sockets.each {|s| s.close }
      retry
    rescue Exception
      sockets.each {|s| s.close }
      raise
    end
    sockets
  end
  class << self
    private :ip_sockets_port0
  end

def self.tcp_server_sockets_port0(host)
    ai_list = Addrinfo.getaddrinfo(host, 0, nil, :STREAM, nil, Socket::AI_PASSIVE)
    sockets = ip_sockets_port0(ai_list, true)
    begin
      sockets.each {|s|
        s.listen(Socket::SOMAXCONN)
      }
    rescue Exception
      sockets.each {|s| s.close }
      raise
    end
    sockets
  end
  class << self
    private :tcp_server_sockets_port0
  end
  # :startdoc:

# creates TCP/IP server sockets for _host_ and _port_.
  # _host_ is optional.
  #
  # If no block given,
  # it returns an array of listening sockets.
  #
  # If a block is given, the block is called with the sockets.
  # The value of the block is returned.
  # The socket is closed when this method returns.
  #
  # If _port_ is 0, actual port number is chosen dynamically.
  # However all sockets in the result has same port number.
  #
  #   # tcp_server_sockets returns two sockets.
  #   sockets = Socket.tcp_server_sockets(1296)
  #   p sockets #=> [#<Socket:fd 3>, #<Socket:fd 4>]
  #
  #   # The sockets contains IPv6 and IPv4 sockets.
  #   sockets.each {|s| p s.local_address }
  #   #=> #<Addrinfo: [::]:1296 TCP>
  #   #   #<Addrinfo: 0.0.0.0:1296 TCP>
  #
  #   # IPv6 and IPv4 socket has same port number, 53114, even if it is chosen dynamically.
  #   sockets = Socket.tcp_server_sockets(0)
  #   sockets.each {|s| p s.local_address }
  #   #=> #<Addrinfo: [::]:53114 TCP>
  #   #   #<Addrinfo: 0.0.0.0:53114 TCP>
  #
  #   # The block is called with the sockets.
  #   Socket.tcp_server_sockets(0) {|sockets|
  #     p sockets #=> [#<Socket:fd 3>, #<Socket:fd 4>]
  #   }
  #
  def self.tcp_server_sockets(host=nil, port)
    if port == 0
      sockets = tcp_server_sockets_port0(host)
    else
      last_error = nil
      sockets = []
      begin
        Addrinfo.foreach(host, port, nil, :STREAM, nil, Socket::AI_PASSIVE) {|ai|
          begin
            s = ai.listen
          rescue SystemCallError
            last_error = $!
            next
          end
          sockets << s
        }
        if sockets.empty?
          raise last_error
        end
      rescue Exception
        sockets.each {|s| s.close }
        raise
      end
    end
    if block_given?
      begin
        yield sockets
      ensure
        sockets.each {|s| s.close if !s.closed? }
      end
    else
      sockets
    end
  end

# yield socket and client address for each a connection accepted via given sockets.
  #
  # The arguments are a list of sockets.
  # The individual argument should be a socket or an array of sockets.
  #
  # This method yields the block sequentially.
  # It means that the next connection is not accepted until the block returns.
  # So concurrent mechanism, thread for example, should be used to service multiple clients at a time.
  #
  def self.accept_loop(*sockets) # :yield: socket, client_addrinfo
    sockets.flatten!(1)
    if sockets.empty?
      raise ArgumentError, "no sockets"
    end
    loop {
      readable, _, _ = IO.select(sockets)
      readable.each {|r|
        begin
          sock, addr = r.accept_nonblock
        rescue IO::WaitReadable
          next
        end
        yield sock, addr
      }
    }
  end

# creates a TCP/IP server on _port_ and calls the block for each connection accepted.
  # The block is called with a socket and a client_address as an Addrinfo object.
  #
  # If _host_ is specified, it is used with _port_ to determine the server addresses.
  #
  # The socket is *not* closed when the block returns.
  # So application should close it explicitly.
  #
  # This method calls the block sequentially.
  # It means that the next connection is not accepted until the block returns.
  # So concurrent mechanism, thread for example, should be used to service multiple clients at a time.
  #
  # Note that Addrinfo.getaddrinfo is used to determine the server socket addresses.
  # When Addrinfo.getaddrinfo returns two or more addresses,
  # IPv4 and IPv6 address for example,
  # all of them are used.
  # Socket.tcp_server_loop succeeds if one socket can be used at least.
  #
  #   # Sequential echo server.
  #   # It services only one client at a time.
  #   Socket.tcp_server_loop(16807) {|sock, client_addrinfo|
  #     begin
  #       IO.copy_stream(sock, sock)
  #     ensure
  #       sock.close
  #     end
  #   }
  #
  #   # Threaded echo server
  #   # It services multiple clients at a time.
  #   # Note that it may accept connections too much.
  #   Socket.tcp_server_loop(16807) {|sock, client_addrinfo|
  #     Thread.new {
  #       begin
  #         IO.copy_stream(sock, sock)
  #       ensure
  #         sock.close
  #       end
  #     }
  #   }
  #
  def self.tcp_server_loop(host=nil, port, &b) # :yield: socket, client_addrinfo
    tcp_server_sockets(host, port) {|sockets|
      accept_loop(sockets, &b)
    }
  end

# :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
  #     }
  #   }
  #
  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 if !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 if !a.ipv6?
          ip_list << Addrinfo.new(a.to_sockaddr, :INET6, :DGRAM, 0);
        }
      else
        ip_list << ai
      end
    }

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 {|s| s.close if !s.closed? } if sockets
      end
    else
      sockets
    end
  end

# :call-seq:
  #   Socket.udp_server_recv(sockets) {|msg, msg_src| ... }
  #
  # Receive UDP/IP packets from the given _sockets_.
  # For each packet received, the block is called.
  #
  # The block receives _msg_ and _msg_src_.
  # _msg_ is a string which is the payload of the received packet.
  # _msg_src_ is a Socket::UDPSource object which is used for reply.
  #
  # Socket.udp_server_loop can be implemented using this method as follows.
  #
  #   udp_server_sockets(host, port) {|sockets|
  #     loop {
  #       readable, _, _ = IO.select(sockets)
  #       udp_server_recv(readable) {|msg, msg_src| ... }
  #     }
  #   }
  #
  def self.udp_server_recv(sockets)
    sockets.each {|r|
      begin
        msg, sender_addrinfo, _, *controls = r.recvmsg_nonblock
      rescue IO::WaitReadable
        next
      end
      ai = r.local_address
      if ai.ipv6? and pktinfo = controls.find {|c| c.cmsg_is?(:IPV6, :PKTINFO) }
        ai = Addrinfo.udp(pktinfo.ipv6_pktinfo_addr.ip_address, ai.ip_port)
        yield msg, UDPSource.new(sender_addrinfo, ai) {|reply_msg|
          r.sendmsg reply_msg, 0, sender_addrinfo, pktinfo
        }
      else
        yield msg, UDPSource.new(sender_addrinfo, ai) {|reply_msg|
          r.send reply_msg, 0, sender_addrinfo
        }
      end
    }
  end

# :call-seq:
  #   Socket.udp_server_loop_on(sockets) {|msg, msg_src| ... }
  #
  # Run UDP/IP server loop on the given sockets.
  #
  # The return value of Socket.udp_server_sockets is appropriate for the argument.
  #
  # It calls the block for each message received.
  #
  def self.udp_server_loop_on(sockets, &b) # :yield: msg, msg_src
    loop {
      readable, _, _ = IO.select(sockets)
      udp_server_recv(readable, &b)
    }
  end

# :call-seq:
  #   Socket.udp_server_loop(port) {|msg, msg_src| ... }
  #   Socket.udp_server_loop(host, port) {|msg, msg_src| ... }
  #
  # creates a UDP/IP server on _port_ and calls the block for each message arrived.
  # The block is called with the message and its source information.
  #
  # This method allocates sockets internally using _port_.
  # If _host_ is specified, it is used conjunction with _port_ to determine the server addresses.
  #
  # The _msg_ is a string.
  #
  # The _msg_src_ is a Socket::UDPSource object.
  # It is used for reply.
  #
  #   # UDP/IP echo server.
  #   Socket.udp_server_loop(9261) {|msg, msg_src|
  #     msg_src.reply msg
  #   }
  #
  def self.udp_server_loop(host=nil, port, &b) # :yield: message, message_source
    udp_server_sockets(host, port) {|sockets|
      udp_server_loop_on(sockets, &b)
    }
  end

# UDP/IP address information used by Socket.udp_server_loop.
  class UDPSource
    # +remote_address+ is an Addrinfo object.
    #
    # +local_address+ is an Addrinfo object.
    #
    # +reply_proc+ is a Proc used to send reply back to the source.
    def initialize(remote_address, local_address, &reply_proc)
      @remote_address = remote_address
      @local_address = local_address
      @reply_proc = reply_proc
    end

# Address of the source
    attr_reader :remote_address

# Local address
    attr_reader :local_address

def inspect # :nodoc:
      "\#<#{self.class}: #{@remote_address.inspect_sockaddr} to #{@local_address.inspect_sockaddr}>"
    end

# Sends the String +msg+ to the source
    def reply(msg)
      @reply_proc.call msg
    end
  end

# creates a new socket connected to path using UNIX socket socket.
  #
  # If a block is given, the block is called with the socket.
  # The value of the block is returned.
  # The socket is closed when this method returns.
  #
  # If no block is given, the socket is returned.
  #
  #   # talk to /tmp/sock socket.
  #   Socket.unix("/tmp/sock") {|sock|
  #     t = Thread.new { IO.copy_stream(sock, STDOUT) }
  #     IO.copy_stream(STDIN, sock)
  #     t.join
  #   }
  #
  def self.unix(path) # :yield: socket
    addr = Addrinfo.unix(path)
    sock = addr.connect
    if block_given?
      begin
        yield sock
      ensure
        sock.close if !sock.closed?
      end
    else
      sock
    end
  end

# creates a UNIX server socket on _path_
  #
  # If no block given, it returns a listening socket.
  #
  # If a block is given, it is called with the socket and the block value is returned.
  # When the block exits, the socket is closed and the socket file is removed.
  #
  #   socket = Socket.unix_server_socket("/tmp/s")
  #   p socket                  #=> #<Socket:fd 3>
  #   p socket.local_address    #=> #<Addrinfo: /tmp/s SOCK_STREAM>
  #
  #   Socket.unix_server_socket("/tmp/sock") {|s|
  #     p s                     #=> #<Socket:fd 3>
  #     p s.local_address       #=> # #<Addrinfo: /tmp/sock SOCK_STREAM>
  #   }
  #
  def self.unix_server_socket(path)
    if !unix_socket_abstract_name?(path)
      begin
        st = File.lstat(path)
      rescue Errno::ENOENT
      end
      if st && st.socket? && st.owned?
        File.unlink path
      end
    end
    s = Addrinfo.unix(path).listen
    if block_given?
      begin
        yield s
      ensure
        s.close if !s.closed?
        if !unix_socket_abstract_name?(path)
          File.unlink path
        end
      end
    else
      s
    end
  end

class << self
    private

def unix_socket_abstract_name?(path)
      /linux/ =~ RUBY_PLATFORM && /\A(\0|\z)/ =~ path
    end
  end

# creates a UNIX socket server on _path_.
  # It calls the block for each socket accepted.
  #
  # If _host_ is specified, it is used with _port_ to determine the server ports.
  #
  # The socket is *not* closed when the block returns.
  # So application should close it.
  #
  # This method deletes the socket file pointed by _path_ at first if
  # the file is a socket file and it is owned by the user of the application.
  # This is safe only if the directory of _path_ is not changed by a malicious user.
  # So don't use /tmp/malicious-users-directory/socket.
  # Note that /tmp/socket and /tmp/your-private-directory/socket is safe assuming that /tmp has sticky bit.
  #
  #   # Sequential echo server.
  #   # It services only one client at a time.
  #   Socket.unix_server_loop("/tmp/sock") {|sock, client_addrinfo|
  #     begin
  #       IO.copy_stream(sock, sock)
  #     ensure
  #       sock.close
  #     end
  #   }
  #
  def self.unix_server_loop(path, &b) # :yield: socket, client_addrinfo
    unix_server_socket(path) {|serv|
      accept_loop(serv, &b)
    }
  end

end

Back