Class: Socket

Inherits:
BasicSocket show all
Defined in:
socket.c,
lib/socket.rb

Overview

Class Socket provides access to the underlying operating system socket implementations. It can be used to provide more operating system specific functionality than the protocol-specific socket classes.

The constants defined under Socket::Constants are also defined under Socket. For example, Socket::AF_INET is usable as well as Socket::Constants::AF_INET. See Socket::Constants for the list of constants.

What's a socket?

Sockets are endpoints of a bidirectionnal communication channel. Sockets can communicate within a process, between processes on the same machine or between different machines. There are many types of socket: TCPSocket, UDPSocket or UNIXSocket for example.

Sockets have their own vocabulary:

domain

The family of protocols: Socket::PF_INET, Socket::PF_INET6, Socket::PF_UNIX, etc.

type

The type of communications between the two endpoints, typically Socket::SOCK_STREAM or Socket::SOCK_DGRAM.

protocol

Typically zero. This may be used to identify a variant of a protocol.

hostname

The identifier of a network interface:

* a string (hostname, IPv4 or IPv6 adress or <tt><broadcast></tt>
  which specifies a broadcast address)
* a zero-length string which specifies INADDR_ANY
* an integer (interpreted as binary address in host byte order).

Quick start

Some classes such as TCPSocket, UDPSocket or UNIXSocket ease use of sockets of these types compared to C programming.

# Creating a TCP socket in a C-like manner
s = Socket.new Socket::INET, Socket::SOCK_STREAM
s.connect Socket.pack_sockaddr_in(80, 'example.com')

# Using TCPSocket
s = TCPSocket.new 'example.com', 80

A simple server would look like:

require 'socket'

server = TCPServer.new 2000 # Server bound to port 2000

loop do
  client = server.accept    # Wait for a client to connect
  client.puts "Hello !"
  client.puts "Time is #{Time.now}"
  client.close
end

A simple client may look like:

require 'socket'

s = TCPSocket.new 'localhost', 2000

while line = s.gets # Read lines from socket
  puts line         # and print them
end

s.close             # close socket when done

Exception Handling

Ruby's Socket implementation raises exceptions based on the error generated by the system dependent implementation. This is why the methods are documented in a way that isolate Unix-based system exceptions from Windows based exceptions. If more information on particular exception is needed please refer to the Unix manual pages or the Windows WinSock reference.

Convenient methods

Although the general way to create socket is Socket.new, there are several methods for socket creation for most cases.

TCP client socket

Socket.tcp, TCPSocket.open

TCP server socket

Socket.tcp_server_loop, TCPServer.open

UNIX client socket

Socket.unix, UNIXSocket.open

UNIX server socket

Socket.unix_server_loop, UNIXServer.open

Documentation by

  • Zach Dennis

  • Sam Roberts

  • Programming Ruby from The Pragmatic Bookshelf.

Much material in this documentation is taken with permission from Programming Ruby from The Pragmatic Bookshelf.

Defined Under Namespace

Modules: Constants Classes: AncillaryData, UDPSource

Constant Summary collapse

SOCK_STREAM =

A stream socket provides a sequenced, reliable two-way connection for a byte stream

INT2NUM(SOCK_STREAM)
SOCK_DGRAM =

A datagram socket provides connectionless, unreliable messaging

INT2NUM(SOCK_DGRAM)
SOCK_RAW =

A raw socket provides low-level access for direct access or implementing network protocols

INT2NUM(SOCK_RAW)
SOCK_RDM =

A reliable datagram socket provides reliable delivery of messages

INT2NUM(SOCK_RDM)
SOCK_SEQPACKET =

A sequential packet socket provides sequenced, reliable two-way connection for datagrams

INT2NUM(SOCK_SEQPACKET)
SOCK_PACKET =

Device-level packet access

INT2NUM(SOCK_PACKET)
AF_UNSPEC =

Unspecified protocol, any supported address family

INT2NUM(AF_UNSPEC)
PF_UNSPEC =

Unspecified protocol, any supported address family

INT2NUM(PF_UNSPEC)
AF_INET =

IPv4 protocol

INT2NUM(AF_INET)
PF_INET =

IPv4 protocol

INT2NUM(PF_INET)
AF_INET6 =

IPv6 protocol

INT2NUM(AF_INET6)
PF_INET6 =

IPv6 protocol

INT2NUM(PF_INET6)
AF_UNIX =

UNIX sockets

INT2NUM(AF_UNIX)
PF_UNIX =

UNIX sockets

INT2NUM(PF_UNIX)
AF_AX25 =

AX.25 protocol

INT2NUM(AF_AX25)
PF_AX25 =

AX.25 protocol

INT2NUM(PF_AX25)
AF_IPX =

IPX protocol

INT2NUM(AF_IPX)
PF_IPX =

IPX protocol

INT2NUM(PF_IPX)
AF_APPLETALK =

AppleTalk protocol

INT2NUM(AF_APPLETALK)
PF_APPLETALK =

AppleTalk protocol

INT2NUM(PF_APPLETALK)
AF_LOCAL =

Host-internal protocols

INT2NUM(AF_LOCAL)
PF_LOCAL =

Host-internal protocols

INT2NUM(PF_LOCAL)
INT2NUM(AF_IMPLINK)
INT2NUM(PF_IMPLINK)
AF_PUP =

PARC Universal Packet protocol

INT2NUM(AF_PUP)
PF_PUP =

PARC Universal Packet protocol

INT2NUM(PF_PUP)
AF_CHAOS =

MIT CHAOS protocols

INT2NUM(AF_CHAOS)
PF_CHAOS =

MIT CHAOS protocols

INT2NUM(PF_CHAOS)
AF_NS =

XEROX NS protocols

INT2NUM(AF_NS)
PF_NS =

XEROX NS protocols

INT2NUM(PF_NS)
AF_ISO =

ISO Open Systems Interconnection protocols

INT2NUM(AF_ISO)
PF_ISO =

ISO Open Systems Interconnection protocols

INT2NUM(PF_ISO)
AF_OSI =

ISO Open Systems Interconnection protocols

INT2NUM(AF_OSI)
PF_OSI =

ISO Open Systems Interconnection protocols

INT2NUM(PF_OSI)
AF_ECMA =

European Computer Manufacturers protocols

INT2NUM(AF_ECMA)
PF_ECMA =

European Computer Manufacturers protocols

INT2NUM(PF_ECMA)
AF_DATAKIT =

Datakit protocol

INT2NUM(AF_DATAKIT)
PF_DATAKIT =

Datakit protocol

INT2NUM(PF_DATAKIT)
AF_CCITT =

CCITT (now ITU-T) protocols

INT2NUM(AF_CCITT)
PF_CCITT =

CCITT (now ITU-T) protocols

INT2NUM(PF_CCITT)
AF_SNA =

IBM SNA protocol

INT2NUM(AF_SNA)
PF_SNA =

IBM SNA protocol

INT2NUM(PF_SNA)
AF_DEC =

DECnet protocol

INT2NUM(AF_DEC)
PF_DEC =

DECnet protocol

INT2NUM(PF_DEC)
AF_DLI =

DEC Direct Data Link Interface protocol

INT2NUM(AF_DLI)
PF_DLI =

DEC Direct Data Link Interface protocol

INT2NUM(PF_DLI)
AF_LAT =

Local Area Transport protocol

INT2NUM(AF_LAT)
PF_LAT =

Local Area Transport protocol

INT2NUM(PF_LAT)
INT2NUM(AF_HYLINK)
INT2NUM(PF_HYLINK)
AF_ROUTE =

Internal routing protocol

INT2NUM(AF_ROUTE)
PF_ROUTE =

Internal routing protocol

INT2NUM(PF_ROUTE)
INT2NUM(AF_LINK)
INT2NUM(PF_LINK)
AF_COIP =

Connection-oriented IP

INT2NUM(AF_COIP)
PF_COIP =

Connection-oriented IP

INT2NUM(PF_COIP)
AF_CNT =

Computer Network Technology

INT2NUM(AF_CNT)
PF_CNT =

Computer Network Technology

INT2NUM(PF_CNT)
AF_SIP =

Simple Internet Protocol

INT2NUM(AF_SIP)
PF_SIP =

Simple Internet Protocol

INT2NUM(PF_SIP)
AF_NDRV =

Network driver raw access

INT2NUM(AF_NDRV)
PF_NDRV =

Network driver raw access

INT2NUM(PF_NDRV)
AF_ISDN =

Integrated Services Digital Network

INT2NUM(AF_ISDN)
PF_ISDN =

Integrated Services Digital Network

INT2NUM(PF_ISDN)
AF_NATM =

Native ATM access

INT2NUM(AF_NATM)
PF_NATM =

Native ATM access

INT2NUM(PF_NATM)
AF_SYSTEM = 
INT2NUM(AF_SYSTEM)
PF_SYSTEM = 
INT2NUM(PF_SYSTEM)
AF_NETBIOS =

NetBIOS

INT2NUM(AF_NETBIOS)
PF_NETBIOS =

NetBIOS

INT2NUM(PF_NETBIOS)
AF_PPP =

Point-to-Point Protocol

INT2NUM(AF_PPP)
PF_PPP =

Point-to-Point Protocol

INT2NUM(PF_PPP)
AF_ATM =

Asynchronous Transfer Mode

INT2NUM(AF_ATM)
PF_ATM =

Asynchronous Transfer Mode

INT2NUM(PF_ATM)
AF_NETGRAPH =

Netgraph sockets

INT2NUM(AF_NETGRAPH)
PF_NETGRAPH =

Netgraph sockets

INT2NUM(PF_NETGRAPH)
AF_MAX =

Maximum address family for this platform

INT2NUM(AF_MAX)
PF_MAX =

Maximum address family for this platform

INT2NUM(PF_MAX)
AF_PACKET =

Direct link-layer access

INT2NUM(AF_PACKET)
PF_PACKET =

Direct link-layer access

INT2NUM(PF_PACKET)
AF_E164 =

CCITT (ITU-T) E.164 recommendation

INT2NUM(AF_E164)
PF_XTP =

eXpress Transfer Protocol

INT2NUM(PF_XTP)
PF_RTIP = 
INT2NUM(PF_RTIP)
PF_PIP = 
INT2NUM(PF_PIP)
PF_KEY = 
INT2NUM(PF_KEY)
MSG_OOB =

Process out-of-band data

INT2NUM(MSG_OOB)
MSG_PEEK =

Peek at incoming message

INT2NUM(MSG_PEEK)
MSG_DONTROUTE =

Send without using the routing tables

INT2NUM(MSG_DONTROUTE)
MSG_EOR =

Data completes record

INT2NUM(MSG_EOR)
MSG_TRUNC =

Data discarded before delivery

INT2NUM(MSG_TRUNC)
MSG_CTRUNC =

Control data lost before delivery

INT2NUM(MSG_CTRUNC)
MSG_WAITALL =

Wait for full request or error

INT2NUM(MSG_WAITALL)
MSG_DONTWAIT =

This message should be non-blocking

INT2NUM(MSG_DONTWAIT)
MSG_EOF =

Data completes connection

INT2NUM(MSG_EOF)
MSG_FLUSH =

Start of a hold sequence. Dumps to so_temp

INT2NUM(MSG_FLUSH)
MSG_HOLD =

Hold fragment in so_temp

INT2NUM(MSG_HOLD)
MSG_SEND =

Send the packet in so_temp

INT2NUM(MSG_SEND)
MSG_HAVEMORE =

Data ready to be read

INT2NUM(MSG_HAVEMORE)
MSG_RCVMORE =

Data remains in the current packet

INT2NUM(MSG_RCVMORE)
MSG_COMPAT =

End of record

INT2NUM(MSG_COMPAT)
MSG_PROXY =

Wait for full request

INT2NUM(MSG_PROXY)
MSG_FIN = 
INT2NUM(MSG_FIN)
MSG_SYN = 
INT2NUM(MSG_SYN)
MSG_CONFIRM =

Confirm path validity

INT2NUM(MSG_CONFIRM)
MSG_RST = 
INT2NUM(MSG_RST)
MSG_ERRQUEUE =

Fetch message from error queue

INT2NUM(MSG_ERRQUEUE)
MSG_NOSIGNAL =

Do not generate SIGPIPE

INT2NUM(MSG_NOSIGNAL)
MSG_MORE =

Sender will send more

INT2NUM(MSG_MORE)
SOL_SOCKET =

Socket-level options

INT2NUM(SOL_SOCKET)
SOL_IP =

IP socket options

INT2NUM(SOL_IP)
SOL_IPX =

IPX socket options

INT2NUM(SOL_IPX)
SOL_AX25 =

AX.25 socket options

INT2NUM(SOL_AX25)
SOL_ATALK =

AppleTalk socket options

INT2NUM(SOL_ATALK)
SOL_TCP =

TCP socket options

INT2NUM(SOL_TCP)
SOL_UDP =

UDP socket options

INT2NUM(SOL_UDP)
IPPROTO_IP =

Dummy protocol for IP

INT2NUM(IPPROTO_IP)
IPPROTO_ICMP =

Control message protocol

INT2NUM(IPPROTO_ICMP)
IPPROTO_IGMP =

Group Management Protocol

INT2NUM(IPPROTO_IGMP)
IPPROTO_GGP =

Gateway to Gateway Protocol

INT2NUM(IPPROTO_GGP)
IPPROTO_TCP =

TCP

INT2NUM(IPPROTO_TCP)
IPPROTO_EGP =

Exterior Gateway Protocol

INT2NUM(IPPROTO_EGP)
IPPROTO_PUP =

PARC Universal Packet protocol

INT2NUM(IPPROTO_PUP)
IPPROTO_UDP =

UDP

INT2NUM(IPPROTO_UDP)
IPPROTO_IDP =

XNS IDP

INT2NUM(IPPROTO_IDP)
IPPROTO_HELLO =

"hello" routing protocol

INT2NUM(IPPROTO_HELLO)
IPPROTO_ND =

Sun net disk protocol

INT2NUM(IPPROTO_ND)
IPPROTO_TP =

ISO transport protocol class 4

INT2NUM(IPPROTO_TP)
IPPROTO_XTP =

Xpress Transport Protocol

INT2NUM(IPPROTO_XTP)
IPPROTO_EON =

ISO cnlp

INT2NUM(IPPROTO_EON)
IPPROTO_BIP = 
INT2NUM(IPPROTO_BIP)
IPPROTO_AH =

IP6 auth header

INT2NUM(IPPROTO_AH)
IPPROTO_DSTOPTS =

IP6 destination option

INT2NUM(IPPROTO_DSTOPTS)
IPPROTO_ESP =

IP6 Encapsulated Security Payload

INT2NUM(IPPROTO_ESP)
IPPROTO_FRAGMENT =

IP6 fragmentation header

INT2NUM(IPPROTO_FRAGMENT)
IPPROTO_HOPOPTS =

IP6 hop-by-hop options

INT2NUM(IPPROTO_HOPOPTS)
IPPROTO_ICMPV6 =

ICMP6

INT2NUM(IPPROTO_ICMPV6)
IPPROTO_IPV6 =

IP6 header

INT2NUM(IPPROTO_IPV6)
IPPROTO_NONE =

IP6 no next header

INT2NUM(IPPROTO_NONE)
IPPROTO_ROUTING =

IP6 routing header

INT2NUM(IPPROTO_ROUTING)
IPPROTO_RAW =

Raw IP packet

INT2NUM(IPPROTO_RAW)
IPPROTO_MAX =

Maximum IPPROTO constant

INT2NUM(IPPROTO_MAX)
IPPORT_RESERVED =

Default minimum address for bind or connect

INT2NUM(IPPORT_RESERVED)
IPPORT_USERRESERVED =

Default maximum address for bind or connect

INT2NUM(IPPORT_USERRESERVED)
INADDR_ANY =

A socket bound to INADDR_ANY receives packets from all interfaces and sends from the default IP address

UINT2NUM(INADDR_ANY)
INADDR_BROADCAST =

The network broadcast address

UINT2NUM(INADDR_BROADCAST)
INADDR_LOOPBACK =

The loopback address

UINT2NUM(INADDR_LOOPBACK)
INADDR_UNSPEC_GROUP =

The reserved multicast group

UINT2NUM(INADDR_UNSPEC_GROUP)
INADDR_ALLHOSTS_GROUP =

Multicast group for all systems on this subset

UINT2NUM(INADDR_ALLHOSTS_GROUP)
INADDR_MAX_LOCAL_GROUP =

The last local network multicast group

UINT2NUM(INADDR_MAX_LOCAL_GROUP)
INADDR_NONE =

A bitmask for matching no valid IP address

UINT2NUM(INADDR_NONE)
IP_OPTIONS =

IP options to be included in packets

INT2NUM(IP_OPTIONS)
IP_HDRINCL =

Header is included with data

INT2NUM(IP_HDRINCL)
IP_TOS =

IP type-of-service

INT2NUM(IP_TOS)
IP_TTL =

IP time-to-live

INT2NUM(IP_TTL)
IP_RECVOPTS =

Receive all IP options with datagram

INT2NUM(IP_RECVOPTS)
IP_RECVRETOPTS =

Receive all IP options for response

INT2NUM(IP_RECVRETOPTS)
IP_RECVDSTADDR =

Receive IP destination address with datagram

INT2NUM(IP_RECVDSTADDR)
IP_RETOPTS =

IP options to be included in datagrams

INT2NUM(IP_RETOPTS)
IP_MINTTL =

Minimum TTL allowed for received packets

INT2NUM(IP_MINTTL)
IP_DONTFRAG =

Don't fragment packets

INT2NUM(IP_DONTFRAG)
IP_SENDSRCADDR =

Source address for outgoing UDP datagrams

INT2NUM(IP_SENDSRCADDR)
IP_ONESBCAST =

Force outgoing broadcast datagrams to have the undirected broadcast address

INT2NUM(IP_ONESBCAST)
IP_RECVTTL =

Receive IP TTL with datagrams

INT2NUM(IP_RECVTTL)
IP_RECVIF =

Receive interface information with datagrams

INT2NUM(IP_RECVIF)
IP_RECVSLLA =

Receive link-layer address with datagrams

INT2NUM(IP_RECVSLLA)
IP_PORTRANGE =

Set the port range for sockets with unspecified port numbers

INT2NUM(IP_PORTRANGE)
IP_MULTICAST_IF =

IP multicast interface

INT2NUM(IP_MULTICAST_IF)
IP_MULTICAST_TTL =

IP multicast TTL

INT2NUM(IP_MULTICAST_TTL)
IP_MULTICAST_LOOP =

IP multicast loopback

INT2NUM(IP_MULTICAST_LOOP)
IP_ADD_MEMBERSHIP =

Add a multicast group membership

INT2NUM(IP_ADD_MEMBERSHIP)
IP_DROP_MEMBERSHIP =

Drop a multicast group membership

INT2NUM(IP_DROP_MEMBERSHIP)
IP_DEFAULT_MULTICAST_TTL =

Default multicast TTL

INT2NUM(IP_DEFAULT_MULTICAST_TTL)
IP_DEFAULT_MULTICAST_LOOP =

Default multicast loopback

INT2NUM(IP_DEFAULT_MULTICAST_LOOP)
IP_MAX_MEMBERSHIPS =

Maximum number multicast groups a socket can join

INT2NUM(IP_MAX_MEMBERSHIPS)
IP_ROUTER_ALERT =

Notify transit routers to more closely examine the contents of an IP packet

INT2NUM(IP_ROUTER_ALERT)
IP_PKTINFO =

Receive packet information with datagrams

INT2NUM(IP_PKTINFO)
IP_PKTOPTIONS =

Receive packet options with datagrams

INT2NUM(IP_PKTOPTIONS)
IP_MTU_DISCOVER =

Path MTU discovery

INT2NUM(IP_MTU_DISCOVER)
IP_RECVERR =

Enable extended reliable error message passing

INT2NUM(IP_RECVERR)
IP_RECVTOS =

Receive TOS with incoming packets

INT2NUM(IP_RECVTOS)
IP_MTU =

The Maximum Transmission Unit of the socket

INT2NUM(IP_MTU)
IP_FREEBIND =

Allow binding to nonexistent IP addresses

INT2NUM(IP_FREEBIND)
IP_IPSEC_POLICY =

IPsec security policy

INT2NUM(IP_IPSEC_POLICY)
IP_XFRM_POLICY = 
INT2NUM(IP_XFRM_POLICY)
IP_PASSSEC =

Retrieve security context with datagram

INT2NUM(IP_PASSSEC)
IP_PMTUDISC_DONT =

Never send DF frames

INT2NUM(IP_PMTUDISC_DONT)
IP_PMTUDISC_WANT =

Use per-route hints

INT2NUM(IP_PMTUDISC_WANT)
IP_PMTUDISC_DO =

Always send DF frames

INT2NUM(IP_PMTUDISC_DO)
IP_UNBLOCK_SOURCE =

Unblock IPv4 multicast packets with a give source address

INT2NUM(IP_UNBLOCK_SOURCE)
IP_BLOCK_SOURCE =

Block IPv4 multicast packets with a give source address

INT2NUM(IP_BLOCK_SOURCE)
IP_ADD_SOURCE_MEMBERSHIP =

Add a multicast group membership

INT2NUM(IP_ADD_SOURCE_MEMBERSHIP)
IP_DROP_SOURCE_MEMBERSHIP =

Drop a multicast group membership

INT2NUM(IP_DROP_SOURCE_MEMBERSHIP)
IP_MSFILTER =

Multicast source filtering

INT2NUM(IP_MSFILTER)
MCAST_JOIN_GROUP =

Join a multicast group

INT2NUM(MCAST_JOIN_GROUP)
MCAST_BLOCK_SOURCE =

Block multicast packets from this source

INT2NUM(MCAST_BLOCK_SOURCE)
MCAST_UNBLOCK_SOURCE =

Unblock multicast packets from this source

INT2NUM(MCAST_UNBLOCK_SOURCE)
MCAST_LEAVE_GROUP =

Leave a multicast group

INT2NUM(MCAST_LEAVE_GROUP)
MCAST_JOIN_SOURCE_GROUP =

Join a multicast source group

INT2NUM(MCAST_JOIN_SOURCE_GROUP)
MCAST_LEAVE_SOURCE_GROUP =

Leave a multicast source group

INT2NUM(MCAST_LEAVE_SOURCE_GROUP)
MCAST_MSFILTER =

Multicast source filtering

INT2NUM(MCAST_MSFILTER)
MCAST_EXCLUDE =

Exclusive multicast source filter

INT2NUM(MCAST_EXCLUDE)
MCAST_INCLUDE =

Inclusive multicast source filter

INT2NUM(MCAST_INCLUDE)
SO_DEBUG =

Debug info recording

INT2NUM(SO_DEBUG)
SO_REUSEADDR =

Allow local address reuse

INT2NUM(SO_REUSEADDR)
SO_REUSEPORT =

Allow local address and port reuse

INT2NUM(SO_REUSEPORT)
SO_TYPE =

Get the socket type

INT2NUM(SO_TYPE)
SO_ERROR =

Get and clear the error status

INT2NUM(SO_ERROR)
SO_DONTROUTE =

Use interface addresses

INT2NUM(SO_DONTROUTE)
SO_BROADCAST =

Permit sending of broadcast messages

INT2NUM(SO_BROADCAST)
SO_SNDBUF =

Send buffer size

INT2NUM(SO_SNDBUF)
SO_RCVBUF =

Receive buffer size

INT2NUM(SO_RCVBUF)
SO_KEEPALIVE =

Keep connections alive

INT2NUM(SO_KEEPALIVE)
SO_OOBINLINE =

Leave received out-of-band data in-line

INT2NUM(SO_OOBINLINE)
SO_NO_CHECK =

Disable checksums

INT2NUM(SO_NO_CHECK)
SO_PRIORITY =

The protocol-defined priority for all packets on this socket

INT2NUM(SO_PRIORITY)
SO_LINGER =

Linger on close if data is present

INT2NUM(SO_LINGER)
SO_PASSCRED =

Receive SCM_CREDENTIALS messages

INT2NUM(SO_PASSCRED)
SO_PEERCRED =

The credentials of the foreign process connected to this socket

INT2NUM(SO_PEERCRED)
SO_RCVLOWAT =

Receive low-water mark

INT2NUM(SO_RCVLOWAT)
SO_SNDLOWAT =

Send low-water mark

INT2NUM(SO_SNDLOWAT)
SO_RCVTIMEO =

Receive timeout

INT2NUM(SO_RCVTIMEO)
SO_SNDTIMEO =

Send timeout

INT2NUM(SO_SNDTIMEO)
SO_ACCEPTCONN =

Socket has had listen() called on it

INT2NUM(SO_ACCEPTCONN)
SO_USELOOPBACK =

Bypass hardware when possible

INT2NUM(SO_USELOOPBACK)
SO_ACCEPTFILTER =

There is an accept filter

INT2NUM(SO_ACCEPTFILTER)
SO_DONTTRUNC =

Retain unread data

INT2NUM(SO_DONTTRUNC)
SO_WANTMORE =

Give a hint when more data is ready

INT2NUM(SO_WANTMORE)
SO_WANTOOBFLAG =

OOB data is wanted in MSG_FLAG on receive

INT2NUM(SO_WANTOOBFLAG)
SO_NREAD =

Get first packet byte count

INT2NUM(SO_NREAD)
SO_NKE =

Install socket-level Network Kernel Extension

INT2NUM(SO_NKE)
SO_NOSIGPIPE =

Don't SIGPIPE on EPIPE

INT2NUM(SO_NOSIGPIPE)
SO_SECURITY_AUTHENTICATION = 
INT2NUM(SO_SECURITY_AUTHENTICATION)
SO_SECURITY_ENCRYPTION_TRANSPORT = 
INT2NUM(SO_SECURITY_ENCRYPTION_TRANSPORT)
SO_SECURITY_ENCRYPTION_NETWORK = 
INT2NUM(SO_SECURITY_ENCRYPTION_NETWORK)
SO_BINDTODEVICE =

Only send packets from the given interface

INT2NUM(SO_BINDTODEVICE)
SO_ATTACH_FILTER =

Attach an accept filter

INT2NUM(SO_ATTACH_FILTER)
SO_DETACH_FILTER =

Detach an accept filter

INT2NUM(SO_DETACH_FILTER)
SO_PEERNAME =

Name of the connecting user

INT2NUM(SO_PEERNAME)
SO_TIMESTAMP =

Receive timestamp with datagrams (timeval)

INT2NUM(SO_TIMESTAMP)
SO_TIMESTAMPNS =

Receive nanosecond timestamp with datagrams (timespec)

INT2NUM(SO_TIMESTAMPNS)
SO_BINTIME =

Receive timestamp with datagrams (bintime)

INT2NUM(SO_BINTIME)
SO_RECVUCRED =

Receive user credentials with datagram

INT2NUM(SO_RECVUCRED)
SO_MAC_EXEMPT =

Mandatory Access Control exemption for unlabeled peers

INT2NUM(SO_MAC_EXEMPT)
SO_ALLZONES =

Bypass zone boundaries

INT2NUM(SO_ALLZONES)
SOPRI_INTERACTIVE =

Interactive socket priority

INT2NUM(SOPRI_INTERACTIVE)
SOPRI_NORMAL =

Normal socket priority

INT2NUM(SOPRI_NORMAL)
SOPRI_BACKGROUND =

Background socket priority

INT2NUM(SOPRI_BACKGROUND)
IPX_TYPE = 
INT2NUM(IPX_TYPE)
TCP_NODELAY =

Don't delay sending to coalesce packets

INT2NUM(TCP_NODELAY)
TCP_MAXSEG =

Set maximum segment size

INT2NUM(TCP_MAXSEG)
TCP_CORK =

Don't send partial frames

INT2NUM(TCP_CORK)
TCP_DEFER_ACCEPT =

Don't notify a listening socket until data is ready

INT2NUM(TCP_DEFER_ACCEPT)
TCP_INFO =

Retrieve information about this socket

INT2NUM(TCP_INFO)
TCP_KEEPCNT =

Maximum number of keepalive probes allowed before dropping a connection

INT2NUM(TCP_KEEPCNT)
TCP_KEEPIDLE =

Idle time before keepalive probes are sent

INT2NUM(TCP_KEEPIDLE)
TCP_KEEPINTVL =

Time between keepalive probes

INT2NUM(TCP_KEEPINTVL)
TCP_LINGER2 =

Lifetime of orphaned FIN_WAIT2 sockets

INT2NUM(TCP_LINGER2)
TCP_MD5SIG =

Use MD5 digests (RFC2385)

INT2NUM(TCP_MD5SIG)
TCP_NOOPT =

Don't use TCP options

INT2NUM(TCP_NOOPT)
TCP_NOPUSH =

Don't push the last block of write

INT2NUM(TCP_NOPUSH)
TCP_QUICKACK =

Enable quickack mode

INT2NUM(TCP_QUICKACK)
TCP_SYNCNT =

Number of SYN retransmits before a connection is dropped

INT2NUM(TCP_SYNCNT)
TCP_WINDOW_CLAMP =

Clamp the size of the advertised window

INT2NUM(TCP_WINDOW_CLAMP)
UDP_CORK =

Don't send partial frames

INT2NUM(UDP_CORK)
EAI_ADDRFAMILY =

Address family for hostname not supported

INT2NUM(EAI_ADDRFAMILY)
EAI_AGAIN =

Temporary failure in name resolution

INT2NUM(EAI_AGAIN)
EAI_BADFLAGS =

Invalid flags

INT2NUM(EAI_BADFLAGS)
EAI_FAIL =

Non-recoverable failure in name resolution

INT2NUM(EAI_FAIL)
EAI_FAMILY =

Address family not supported

INT2NUM(EAI_FAMILY)
EAI_MEMORY =

Memory allocation failure

INT2NUM(EAI_MEMORY)
EAI_NODATA =

No address associated with hostname

INT2NUM(EAI_NODATA)
EAI_NONAME =

Hostname nor servname, or not known

INT2NUM(EAI_NONAME)
EAI_OVERFLOW =

Argument buffer overflow

INT2NUM(EAI_OVERFLOW)
EAI_SERVICE =

Servname not supported for socket type

INT2NUM(EAI_SERVICE)
EAI_SOCKTYPE =

Socket type not supported

INT2NUM(EAI_SOCKTYPE)
EAI_SYSTEM =

System error returned in errno

INT2NUM(EAI_SYSTEM)
EAI_BADHINTS =

Invalid value for hints

INT2NUM(EAI_BADHINTS)
EAI_PROTOCOL =

Resolved protocol is unknown

INT2NUM(EAI_PROTOCOL)
EAI_MAX =

Maximum error code from getaddrinfo

INT2NUM(EAI_MAX)
AI_PASSIVE =

Get address to use with bind()

INT2NUM(AI_PASSIVE)
AI_CANONNAME =

Fill in the canonical name

INT2NUM(AI_CANONNAME)
AI_NUMERICHOST =

Prevent host name resolution

INT2NUM(AI_NUMERICHOST)
AI_NUMERICSERV =

Prevent service name resolution

INT2NUM(AI_NUMERICSERV)
AI_MASK =

Valid flag mask for getaddrinfo (not for application use)

INT2NUM(AI_MASK)
AI_ALL =

Allow all addresses

INT2NUM(AI_ALL)
AI_V4MAPPED_CFG =

Accept IPv4 mapped addresses if the kernel supports it

INT2NUM(AI_V4MAPPED_CFG)
AI_ADDRCONFIG =

Accept only if any address is assigned

INT2NUM(AI_ADDRCONFIG)
AI_V4MAPPED =

Accept IPv4-mapped IPv6 addresses

INT2NUM(AI_V4MAPPED)
AI_DEFAULT =

Default flags for getaddrinfo

INT2NUM(AI_DEFAULT)
NI_MAXHOST =

Maximum length of a hostname

INT2NUM(NI_MAXHOST)
NI_MAXSERV =

Maximum length of a service name

INT2NUM(NI_MAXSERV)
NI_NOFQDN =

An FQDN is not required for local hosts, return only the local part

INT2NUM(NI_NOFQDN)
NI_NUMERICHOST =

Return a numeric address

INT2NUM(NI_NUMERICHOST)
NI_NAMEREQD =

A name is required

INT2NUM(NI_NAMEREQD)
NI_NUMERICSERV =

Return the service name as a digit string

INT2NUM(NI_NUMERICSERV)
NI_DGRAM =

The service specified is a datagram service (looks up UDP ports)

INT2NUM(NI_DGRAM)
SHUT_RD =

Shut down the reading side of the socket

INT2NUM(SHUT_RD)
SHUT_WR =

Shut down the writing side of the socket

INT2NUM(SHUT_WR)
SHUT_RDWR =

Shut down the both sides of the socket

INT2NUM(SHUT_RDWR)
IPV6_JOIN_GROUP =

Join a group membership

INT2NUM(IPV6_JOIN_GROUP)
IPV6_LEAVE_GROUP =

Leave a group membership

INT2NUM(IPV6_LEAVE_GROUP)
IPV6_MULTICAST_HOPS =

IP6 multicast hops

INT2NUM(IPV6_MULTICAST_HOPS)
IPV6_MULTICAST_IF =

IP6 multicast interface

INT2NUM(IPV6_MULTICAST_IF)
IPV6_MULTICAST_LOOP =

IP6 multicast loopback

INT2NUM(IPV6_MULTICAST_LOOP)
IPV6_UNICAST_HOPS =

IP6 unicast hops

INT2NUM(IPV6_UNICAST_HOPS)
IPV6_V6ONLY =

Only bind IPv6 with a wildcard bind

INT2NUM(IPV6_V6ONLY)
IPV6_CHECKSUM =

Checksum offset for raw sockets

INT2NUM(IPV6_CHECKSUM)
IPV6_DONTFRAG =

Don't fragment packets

INT2NUM(IPV6_DONTFRAG)
IPV6_DSTOPTS =

Destination option

INT2NUM(IPV6_DSTOPTS)
IPV6_HOPLIMIT =

Hop limit

INT2NUM(IPV6_HOPLIMIT)
IPV6_HOPOPTS =

Hop-by-hop option

INT2NUM(IPV6_HOPOPTS)
IPV6_NEXTHOP =

Next hop address

INT2NUM(IPV6_NEXTHOP)
IPV6_PATHMTU =

Retrieve current path MTU

INT2NUM(IPV6_PATHMTU)
IPV6_PKTINFO =

Receive packet information with datagram

INT2NUM(IPV6_PKTINFO)
IPV6_RECVDSTOPTS =

Receive all IP6 options for response

INT2NUM(IPV6_RECVDSTOPTS)
IPV6_RECVHOPLIMIT =

Receive hop limit with datagram

INT2NUM(IPV6_RECVHOPLIMIT)
IPV6_RECVHOPOPTS =

Receive hop-by-hop options

INT2NUM(IPV6_RECVHOPOPTS)
IPV6_RECVPKTINFO =

Receive destination IP address and incoming interface

INT2NUM(IPV6_RECVPKTINFO)
IPV6_RECVRTHDR =

Receive routing header

INT2NUM(IPV6_RECVRTHDR)
IPV6_RECVTCLASS =

Receive traffic class

INT2NUM(IPV6_RECVTCLASS)
IPV6_RTHDR =

Allows removal of sticky routing headers

INT2NUM(IPV6_RTHDR)
IPV6_RTHDRDSTOPTS =

Allows removal of sticky destination options header

INT2NUM(IPV6_RTHDRDSTOPTS)
IPV6_RTHDR_TYPE_0 =

Routing header type 0

INT2NUM(IPV6_RTHDR_TYPE_0)
IPV6_RECVPATHMTU =

Receive current path MTU with datagram

INT2NUM(IPV6_RECVPATHMTU)
IPV6_TCLASS =

Specify the traffic class

INT2NUM(IPV6_TCLASS)
IPV6_USE_MIN_MTU =

Use the minimum MTU size

INT2NUM(IPV6_USE_MIN_MTU)
INET_ADDRSTRLEN =

Maximum length of an IPv4 address string

INT2NUM(INET_ADDRSTRLEN)
INET6_ADDRSTRLEN =

Maximum length of an IPv6 address string

INT2NUM(INET6_ADDRSTRLEN)
IFNAMSIZ =

Maximum interface name size

INT2NUM(IFNAMSIZ)
IF_NAMESIZE =

Maximum interface name size

INT2NUM(IF_NAMESIZE)
SOMAXCONN =

Maximum connection requests that may be queued for a socket

INT2NUM(SOMAXCONN)
SCM_RIGHTS =

Access rights

INT2NUM(SCM_RIGHTS)
SCM_TIMESTAMP =

Timestamp (timeval)

INT2NUM(SCM_TIMESTAMP)
SCM_TIMESTAMPNS =

Timespec (timespec)

INT2NUM(SCM_TIMESTAMPNS)
SCM_BINTIME =

Timestamp (bintime)

INT2NUM(SCM_BINTIME)
SCM_CREDENTIALS =

The sender's credentials

INT2NUM(SCM_CREDENTIALS)
SCM_CREDS =

Process credentials

INT2NUM(SCM_CREDS)
SCM_UCRED =

User credentials

INT2NUM(SCM_UCRED)
LOCAL_PEERCRED =

Retrieve peer credentials

INT2NUM(LOCAL_PEERCRED)
LOCAL_CREDS =

Pass credentials to receiver

INT2NUM(LOCAL_CREDS)
LOCAL_CONNWAIT =

Connect blocks until accepted

INT2NUM(LOCAL_CONNWAIT)

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from BasicSocket

#connect_address

Constructor Details

#new(domain, socktype[, protocol]) ⇒ Object

Creates a new socket object.

domain should be a communications domain such as: :INET, :INET6, :UNIX, etc.

socktype should be a socket type such as: :STREAM, :DGRAM, :RAW, etc.

protocol should be a protocol defined in the domain. This is optional. If it is not given, 0 is used internally.

Socket.new(:INET, :STREAM) # TCP socket
Socket.new(:INET, :DGRAM)  # UDP socket
Socket.new(:UNIX, :STREAM) # UNIX stream socket
Socket.new(:UNIX, :DGRAM)  # UNIX datagram socket



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# File 'socket.c', line 39

static VALUE
sock_initialize(int argc, VALUE *argv, VALUE sock)
{
    VALUE domain, type, protocol;
    int fd;
    int d, t;

    rb_scan_args(argc, argv, "21", &domain, &type, &protocol);
    if (NIL_P(protocol))
        protocol = INT2FIX(0);

    rb_secure(3);
    setup_domain_and_type(domain, &d, type, &t);
    fd = rsock_socket(d, t, NUM2INT(protocol));
    if (fd < 0) rb_sys_fail("socket(2)");

    return rsock_init_sock(sock, fd);
}

Class Method Details

.accept_loop(*sockets) ⇒ Object

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.



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# File 'lib/socket.rb', line 407

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

.getaddrinfo(nodename, servname[, family[, socktype[, protocol[, flags[, reverse_lookup]]]]]) ⇒ Array

Obtains address information for nodename:servname.

family should be an address family such as: :INET, :INET6, :UNIX, etc.

socktype should be a socket type such as: :STREAM, :DGRAM, :RAW, etc.

protocol should be a protocol defined in the family. 0 is default protocol for the family.

flags should be bitwise OR of Socket::AI_* constants.

Socket.getaddrinfo("www.ruby-lang.org", "http", nil, :STREAM)
#=> [["AF_INET", 80, "carbon.ruby-lang.org", "221.186.184.68", 2, 1, 6]] # PF_INET/SOCK_STREAM/IPPROTO_TCP

Socket.getaddrinfo("localhost", nil)
#=> [["AF_INET", 0, "localhost", "127.0.0.1", 2, 1, 6],  # PF_INET/SOCK_STREAM/IPPROTO_TCP
#    ["AF_INET", 0, "localhost", "127.0.0.1", 2, 2, 17], # PF_INET/SOCK_DGRAM/IPPROTO_UDP
#    ["AF_INET", 0, "localhost", "127.0.0.1", 2, 3, 0]]  # PF_INET/SOCK_RAW/IPPROTO_IP

reverse_lookup directs the form of the third element, and has to be one of below. If it is ommitted, the default value is nil.

+true+, +:hostname+:  hostname is obtained from numeric address using reverse lookup, which may take a time.
+false+, +:numeric+:  hostname is same as numeric address.
+nil+:              obey to the current +do_not_reverse_lookup+ flag.

If Addrinfo object is preferred, use Addrinfo.getaddrinfo.

Returns:

  • (Array) 


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# File 'socket.c', line 1112

static VALUE
sock_s_getaddrinfo(int argc, VALUE *argv)
{
    VALUE host, port, family, socktype, protocol, flags, ret, revlookup;
    struct addrinfo hints, *res;
    int norevlookup;

    rb_scan_args(argc, argv, "25", &host, &port, &family, &socktype, &protocol, &flags, &revlookup);

    MEMZERO(&hints, struct addrinfo, 1);
    hints.ai_family = NIL_P(family) ? PF_UNSPEC : rsock_family_arg(family);

    if (!NIL_P(socktype)) {
	hints.ai_socktype = rsock_socktype_arg(socktype);
    }
    if (!NIL_P(protocol)) {
	hints.ai_protocol = NUM2INT(protocol);
    }
    if (!NIL_P(flags)) {
	hints.ai_flags = NUM2INT(flags);
    }
    if (NIL_P(revlookup) || !rsock_revlookup_flag(revlookup, &norevlookup)) {
	norevlookup = rsock_do_not_reverse_lookup;
    }
    res = rsock_getaddrinfo(host, port, &hints, 0);

    ret = make_addrinfo(res, norevlookup);
    freeaddrinfo(res);
    return ret;
}

.gethostbyaddr(address_string[, address_family]) ⇒ Object

Obtains the host information for address.

p Socket.gethostbyaddr([221,186,184,68].pack("CCCC"))
#=> ["carbon.ruby-lang.org", [], 2, "\xDD\xBA\xB8D"]



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# File 'socket.c', line 952

static VALUE
sock_s_gethostbyaddr(int argc, VALUE *argv)
{
    VALUE addr, family;
    struct hostent *h;
    struct sockaddr *sa;
    char **pch;
    VALUE ary, names;
    int t = AF_INET;

    rb_scan_args(argc, argv, "11", &addr, &family);
    sa = (struct sockaddr*)StringValuePtr(addr);
    if (!NIL_P(family)) {
	t = rsock_family_arg(family);
    }
#ifdef AF_INET6
    else if (RSTRING_LEN(addr) == 16) {
	t = AF_INET6;
    }
#endif
    h = gethostbyaddr(RSTRING_PTR(addr), RSTRING_LENINT(addr), t);
    if (h == NULL) {
#ifdef HAVE_HSTRERROR
	extern int h_errno;
	rb_raise(rb_eSocket, "%s", (char*)hstrerror(h_errno));
#else
	rb_raise(rb_eSocket, "host not found");
#endif
    }
    ary = rb_ary_new();
    rb_ary_push(ary, rb_str_new2(h->h_name));
    names = rb_ary_new();
    rb_ary_push(ary, names);
    if (h->h_aliases != NULL) {
	for (pch = h->h_aliases; *pch; pch++) {
	    rb_ary_push(names, rb_str_new2(*pch));
	}
    }
    rb_ary_push(ary, INT2NUM(h->h_addrtype));
#ifdef h_addr
    for (pch = h->h_addr_list; *pch; pch++) {
	rb_ary_push(ary, rb_str_new(*pch, h->h_length));
    }
#else
    rb_ary_push(ary, rb_str_new(h->h_addr, h->h_length));
#endif

    return ary;
}

.gethostbyname(hostname) ⇒ Array

Obtains the host information for hostname.

p Socket.gethostbyname("hal") #=> ["localhost", ["hal"], 2, "\x7F\x00\x00\x01"]

Returns:

  • (Array) 


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# File 'socket.c', line 936

static VALUE
sock_s_gethostbyname(VALUE obj, VALUE host)
{
    rb_secure(3);
    return rsock_make_hostent(host, rsock_addrinfo(host, Qnil, SOCK_STREAM, AI_CANONNAME), sock_sockaddr);
}

.gethostname ⇒ Object 



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# File 'socket.c', line 867

static VALUE
sock_gethostname(VALUE obj)
{
    struct utsname un;

    rb_secure(3);
    uname(&un);
    return rb_str_new2(un.nodename);
}

.getnameinfo(sockaddr[, flags]) ⇒ Array

Obtains name information for sockaddr.

sockaddr should be one of follows.

  • packed sockaddr string such as Socket.sockaddr_in(80, "127.0.0.1")

  • 3-elements array such as ["AF_INET", 80, "127.0.0.1"]

  • 4-elements array such as ["AF_INET", 80, ignored, "127.0.0.1"]

flags should be bitwise OR of Socket::NI_* constants.

Note that the last form is compatible with IPSocket#addr,peeraddr.

Socket.getnameinfo(Socket.sockaddr_in(80, "127.0.0.1"))       #=> ["localhost", "www"]
Socket.getnameinfo(["AF_INET", 80, "127.0.0.1"])              #=> ["localhost", "www"]
Socket.getnameinfo(["AF_INET", 80, "localhost", "127.0.0.1"]) #=> ["localhost", "www"]

If Addrinfo object is preferred, use Addrinfo#getnameinfo.

Returns:

  • (Array) 


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# File 'socket.c', line 1164

static VALUE
sock_s_getnameinfo(int argc, VALUE *argv)
{
    VALUE sa, af = Qnil, host = Qnil, port = Qnil, flags, tmp;
    char *hptr, *pptr;
    char hbuf[1024], pbuf[1024];
    int fl;
    struct addrinfo hints, *res = NULL, *r;
    int error;
    struct sockaddr_storage ss;
    struct sockaddr *sap;

    sa = flags = Qnil;
    rb_scan_args(argc, argv, "11", &sa, &flags);

    fl = 0;
    if (!NIL_P(flags)) {
	fl = NUM2INT(flags);
    }
    tmp = rb_check_sockaddr_string_type(sa);
    if (!NIL_P(tmp)) {
	sa = tmp;
	if (sizeof(ss) < (size_t)RSTRING_LEN(sa)) {
	    rb_raise(rb_eTypeError, "sockaddr length too big");
	}
	memcpy(&ss, RSTRING_PTR(sa), RSTRING_LEN(sa));
	if ((size_t)RSTRING_LEN(sa) != SS_LEN(&ss)) {
	    rb_raise(rb_eTypeError, "sockaddr size differs - should not happen");
	}
	sap = (struct sockaddr*)&ss;
	goto call_nameinfo;
    }
    tmp = rb_check_array_type(sa);
    if (!NIL_P(tmp)) {
	sa = tmp;
	MEMZERO(&hints, struct addrinfo, 1);
	if (RARRAY_LEN(sa) == 3) {
	    af = RARRAY_PTR(sa)[0];
	    port = RARRAY_PTR(sa)[1];
	    host = RARRAY_PTR(sa)[2];
	}
	else if (RARRAY_LEN(sa) >= 4) {
	    af = RARRAY_PTR(sa)[0];
	    port = RARRAY_PTR(sa)[1];
	    host = RARRAY_PTR(sa)[3];
	    if (NIL_P(host)) {
		host = RARRAY_PTR(sa)[2];
	    }
	    else {
		/*
		 * 4th element holds numeric form, don't resolve.
		 * see rsock_ipaddr().
		 */
#ifdef AI_NUMERICHOST /* AIX 4.3.3 doesn't have AI_NUMERICHOST. */
		hints.ai_flags |= AI_NUMERICHOST;
#endif
	    }
	}
	else {
	    rb_raise(rb_eArgError, "array size should be 3 or 4, %ld given",
		     RARRAY_LEN(sa));
	}
	/* host */
	if (NIL_P(host)) {
	    hptr = NULL;
	}
	else {
	    strncpy(hbuf, StringValuePtr(host), sizeof(hbuf));
	    hbuf[sizeof(hbuf) - 1] = '\0';
	    hptr = hbuf;
	}
	/* port */
	if (NIL_P(port)) {
	    strcpy(pbuf, "0");
	    pptr = NULL;
	}
	else if (FIXNUM_P(port)) {
	    snprintf(pbuf, sizeof(pbuf), "%ld", NUM2LONG(port));
	    pptr = pbuf;
	}
	else {
	    strncpy(pbuf, StringValuePtr(port), sizeof(pbuf));
	    pbuf[sizeof(pbuf) - 1] = '\0';
	    pptr = pbuf;
	}
	hints.ai_socktype = (fl & NI_DGRAM) ? SOCK_DGRAM : SOCK_STREAM;
	/* af */
        hints.ai_family = NIL_P(af) ? PF_UNSPEC : rsock_family_arg(af);
	error = rb_getaddrinfo(hptr, pptr, &hints, &res);
	if (error) goto error_exit_addr;
	sap = res->ai_addr;
    }
    else {
	rb_raise(rb_eTypeError, "expecting String or Array");
    }

  call_nameinfo:
    error = rb_getnameinfo(sap, SA_LEN(sap), hbuf, sizeof(hbuf),
			   pbuf, sizeof(pbuf), fl);
    if (error) goto error_exit_name;
    if (res) {
	for (r = res->ai_next; r; r = r->ai_next) {
	    char hbuf2[1024], pbuf2[1024];

	    sap = r->ai_addr;
	    error = rb_getnameinfo(sap, SA_LEN(sap), hbuf2, sizeof(hbuf2),
				   pbuf2, sizeof(pbuf2), fl);
	    if (error) goto error_exit_name;
	    if (strcmp(hbuf, hbuf2) != 0|| strcmp(pbuf, pbuf2) != 0) {
		freeaddrinfo(res);
		rb_raise(rb_eSocket, "sockaddr resolved to multiple nodename");
	    }
	}
	freeaddrinfo(res);
    }
    return rb_assoc_new(rb_str_new2(hbuf), rb_str_new2(pbuf));

  error_exit_addr:
    if (res) freeaddrinfo(res);
    rsock_raise_socket_error("getaddrinfo", error);

  error_exit_name:
    if (res) freeaddrinfo(res);
    rsock_raise_socket_error("getnameinfo", error);
}

.getservbyname(service_name) ⇒ Object .getservbyname(service_name, protocol_name) ⇒ Object

Obtains the port number for service_name.

If protocol_name is not given, "tcp" is assumed.

Socket.getservbyname("smtp")          #=> 25
Socket.getservbyname("shell")         #=> 514
Socket.getservbyname("syslog", "udp") #=> 514



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# File 'socket.c', line 1015

static VALUE
sock_s_getservbyname(int argc, VALUE *argv)
{
    VALUE service, proto;
    struct servent *sp;
    long port;
    const char *servicename, *protoname = "tcp";

    rb_scan_args(argc, argv, "11", &service, &proto);
    StringValue(service);
    if (!NIL_P(proto)) StringValue(proto);
    servicename = StringValueCStr(service);
    if (!NIL_P(proto)) protoname = StringValueCStr(proto);
    sp = getservbyname(servicename, protoname);
    if (sp) {
	port = ntohs(sp->s_port);
    }
    else {
	char *end;

	port = STRTOUL(servicename, &end, 0);
	if (*end != '\0') {
	    rb_raise(rb_eSocket, "no such service %s/%s", servicename, protoname);
	}
    }
    return INT2FIX(port);
}

.getservbyport(port[, protocol_name]) ⇒ Object

Obtains the port number for port.

If protocol_name is not given, "tcp" is assumed.

Socket.getservbyport(80)         #=> "www"
Socket.getservbyport(514, "tcp") #=> "shell"
Socket.getservbyport(514, "udp") #=> "syslog"



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# File 'socket.c', line 1056

static VALUE
sock_s_getservbyport(int argc, VALUE *argv)
{
    VALUE port, proto;
    struct servent *sp;
    long portnum;
    const char *protoname = "tcp";

    rb_scan_args(argc, argv, "11", &port, &proto);
    portnum = NUM2LONG(port);
    if (portnum != (uint16_t)portnum) {
	const char *s = portnum > 0 ? "big" : "small";
	rb_raise(rb_eRangeError, "integer %ld too %s to convert into `int16_t'", portnum, s);
    }
    if (!NIL_P(proto)) protoname = StringValueCStr(proto);

    sp = getservbyport((int)htons((uint16_t)portnum), protoname);
    if (!sp) {
	rb_raise(rb_eSocket, "no such service for port %d/%s", (int)portnum, protoname);
    }
    return rb_tainted_str_new2(sp->s_name);
}

.ip_address_list ⇒ Array

Returns local IP addresses as an array.

The array contains Addrinfo objects.

pp Socket.ip_address_list
#=> [#<Addrinfo: 127.0.0.1>,
     #<Addrinfo: 192.168.0.128>,
     #<Addrinfo: ::1>,
     ...]

Returns:

  • (Array) 


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# File 'socket.c', line 1507

static VALUE
socket_s_ip_address_list(VALUE self)
{
#if defined(HAVE_GETIFADDRS)
    struct ifaddrs *ifp = NULL;
    struct ifaddrs *p;
    int ret;
    VALUE list;

    ret = getifaddrs(&ifp);
    if (ret == -1) {
        rb_sys_fail("getifaddrs");
    }

    list = rb_ary_new();
    for (p = ifp; p; p = p->ifa_next) {
        if (p->ifa_addr != NULL && IS_IP_FAMILY(p->ifa_addr->sa_family)) {
            rb_ary_push(list, sockaddr_obj(p->ifa_addr));
        }
    }

    freeifaddrs(ifp);

    return list;
#elif defined(SIOCGLIFCONF) && defined(SIOCGLIFNUM) && !defined(__hpux)
    /* Solaris if_tcp(7P) */
    /* HP-UX has SIOCGLIFCONF too.  But it uses different struct */
    int fd = -1;
    int ret;
    struct lifnum ln;
    struct lifconf lc;
    char *reason = NULL;
    int save_errno;
    int i;
    VALUE list = Qnil;

    lc.lifc_buf = NULL;

    fd = socket(AF_INET, SOCK_DGRAM, 0);
    if (fd == -1)
        rb_sys_fail("socket");

    memset(&ln, 0, sizeof(ln));
    ln.lifn_family = AF_UNSPEC;

    ret = ioctl(fd, SIOCGLIFNUM, &ln);
    if (ret == -1) {
	reason = "SIOCGLIFNUM";
	goto finish;
    }

    memset(&lc, 0, sizeof(lc));
    lc.lifc_family = AF_UNSPEC;
    lc.lifc_flags = 0;
    lc.lifc_len = sizeof(struct lifreq) * ln.lifn_count;
    lc.lifc_req = xmalloc(lc.lifc_len);

    ret = ioctl(fd, SIOCGLIFCONF, &lc);
    if (ret == -1) {
	reason = "SIOCGLIFCONF";
	goto finish;
    }

    list = rb_ary_new();
    for (i = 0; i < ln.lifn_count; i++) {
	struct lifreq *req = &lc.lifc_req[i];
        if (IS_IP_FAMILY(req->lifr_addr.ss_family)) {
            if (req->lifr_addr.ss_family == AF_INET6 &&
                IN6_IS_ADDR_LINKLOCAL(&((struct sockaddr_in6 *)(&req->lifr_addr))->sin6_addr) &&
                ((struct sockaddr_in6 *)(&req->lifr_addr))->sin6_scope_id == 0) {
                struct lifreq req2;
                memcpy(req2.lifr_name, req->lifr_name, LIFNAMSIZ);
                ret = ioctl(fd, SIOCGLIFINDEX, &req2);
                if (ret == -1) {
                    reason = "SIOCGLIFINDEX";
                    goto finish;
                }
                ((struct sockaddr_in6 *)(&req->lifr_addr))->sin6_scope_id = req2.lifr_index;
            }
            rb_ary_push(list, sockaddr_obj((struct sockaddr *)&req->lifr_addr));
        }
    }

  finish:
    save_errno = errno;
    if (lc.lifc_buf != NULL)
	xfree(lc.lifc_req);
    if (fd != -1)
	close(fd);
    errno = save_errno;

    if (reason)
	rb_sys_fail(reason);
    return list;

#elif defined(SIOCGIFCONF)
    int fd = -1;
    int ret;
#define EXTRA_SPACE (sizeof(struct ifconf) + sizeof(struct sockaddr_storage))
    char initbuf[4096+EXTRA_SPACE];
    char *buf = initbuf;
    int bufsize;
    struct ifconf conf;
    struct ifreq *req;
    VALUE list = Qnil;
    const char *reason = NULL;
    int save_errno;

    fd = socket(AF_INET, SOCK_DGRAM, 0);
    if (fd == -1)
        rb_sys_fail("socket");

    bufsize = sizeof(initbuf);
    buf = initbuf;

  retry:
    conf.ifc_len = bufsize;
    conf.ifc_req = (struct ifreq *)buf;

    /* fprintf(stderr, "bufsize: %d\n", bufsize); */

    ret = ioctl(fd, SIOCGIFCONF, &conf);
    if (ret == -1) {
        reason = "SIOCGIFCONF";
        goto finish;
    }

    /* fprintf(stderr, "conf.ifc_len: %d\n", conf.ifc_len); */

    if (bufsize - EXTRA_SPACE < conf.ifc_len) {
	if (bufsize < conf.ifc_len) {
	    /* NetBSD returns required size for all interfaces. */
	    bufsize = conf.ifc_len + EXTRA_SPACE;
	}
	else {
	    bufsize = bufsize << 1;
	}
	if (buf == initbuf)
	    buf = NULL;
	buf = xrealloc(buf, bufsize);
	goto retry;
    }

    close(fd);
    fd = -1;

    list = rb_ary_new();
    req = conf.ifc_req;
    while ((char*)req < (char*)conf.ifc_req + conf.ifc_len) {
	struct sockaddr *addr = &req->ifr_addr;
        if (IS_IP_FAMILY(addr->sa_family)) {
	    rb_ary_push(list, sockaddr_obj(addr));
	}
#ifdef HAVE_SA_LEN
# ifndef _SIZEOF_ADDR_IFREQ
#  define _SIZEOF_ADDR_IFREQ(r) \
          (sizeof(struct ifreq) + \
           (sizeof(struct sockaddr) < (r).ifr_addr.sa_len ? \
            (r).ifr_addr.sa_len - sizeof(struct sockaddr) : \
            0))
# endif
	req = (struct ifreq *)((char*)req + _SIZEOF_ADDR_IFREQ(*req));
#else
	req = (struct ifreq *)((char*)req + sizeof(struct ifreq));
#endif
    }

  finish:

    save_errno = errno;
    if (buf != initbuf)
        xfree(buf);
    if (fd != -1)
	close(fd);
    errno = save_errno;

    if (reason)
	rb_sys_fail(reason);
    return list;

#undef EXTRA_SPACE
#elif defined(_WIN32)
    typedef struct ip_adapter_unicast_address_st {
	unsigned LONG_LONG dummy0;
	struct ip_adapter_unicast_address_st *Next;
	struct {
	    struct sockaddr *lpSockaddr;
	    int iSockaddrLength;
	} Address;
	int dummy1;
	int dummy2;
	int dummy3;
	long dummy4;
	long dummy5;
	long dummy6;
    } ip_adapter_unicast_address_t;
    typedef struct ip_adapter_anycast_address_st {
	unsigned LONG_LONG dummy0;
	struct ip_adapter_anycast_address_st *Next;
	struct {
	    struct sockaddr *lpSockaddr;
	    int iSockaddrLength;
	} Address;
    } ip_adapter_anycast_address_t;
    typedef struct ip_adapter_addresses_st {
	unsigned LONG_LONG dummy0;
	struct ip_adapter_addresses_st *Next;
	void *dummy1;
	ip_adapter_unicast_address_t *FirstUnicastAddress;
	ip_adapter_anycast_address_t *FirstAnycastAddress;
	void *dummy2;
	void *dummy3;
	void *dummy4;
	void *dummy5;
	void *dummy6;
	BYTE dummy7[8];
	DWORD dummy8;
	DWORD dummy9;
	DWORD dummy10;
	DWORD IfType;
	int OperStatus;
	DWORD dummy12;
	DWORD dummy13[16];
	void *dummy14;
    } ip_adapter_addresses_t;
    typedef ULONG (WINAPI *GetAdaptersAddresses_t)(ULONG, ULONG, PVOID, ip_adapter_addresses_t *, PULONG);
    HMODULE h;
    GetAdaptersAddresses_t pGetAdaptersAddresses;
    ULONG len;
    DWORD ret;
    ip_adapter_addresses_t *adapters;
    VALUE list;

    h = LoadLibrary("iphlpapi.dll");
    if (!h)
	rb_notimplement();
    pGetAdaptersAddresses = (GetAdaptersAddresses_t)GetProcAddress(h, "GetAdaptersAddresses");
    if (!pGetAdaptersAddresses) {
	FreeLibrary(h);
	rb_notimplement();
    }

    ret = pGetAdaptersAddresses(AF_UNSPEC, 0, NULL, NULL, &len);
    if (ret != ERROR_SUCCESS && ret != ERROR_BUFFER_OVERFLOW) {
	errno = rb_w32_map_errno(ret);
	FreeLibrary(h);
	rb_sys_fail("GetAdaptersAddresses");
    }
    adapters = (ip_adapter_addresses_t *)ALLOCA_N(BYTE, len);
    ret = pGetAdaptersAddresses(AF_UNSPEC, 0, NULL, adapters, &len);
    if (ret != ERROR_SUCCESS) {
	errno = rb_w32_map_errno(ret);
	FreeLibrary(h);
	rb_sys_fail("GetAdaptersAddresses");
    }

    list = rb_ary_new();
    for (; adapters; adapters = adapters->Next) {
	ip_adapter_unicast_address_t *uni;
	ip_adapter_anycast_address_t *any;
	if (adapters->OperStatus != 1)	/* 1 means IfOperStatusUp */
	    continue;
	for (uni = adapters->FirstUnicastAddress; uni; uni = uni->Next) {
#ifndef INET6
	    if (uni->Address.lpSockaddr->sa_family == AF_INET)
#else
	    if (IS_IP_FAMILY(uni->Address.lpSockaddr->sa_family))
#endif
		rb_ary_push(list, sockaddr_obj(uni->Address.lpSockaddr));
	}
	for (any = adapters->FirstAnycastAddress; any; any = any->Next) {
#ifndef INET6
	    if (any->Address.lpSockaddr->sa_family == AF_INET)
#else
	    if (IS_IP_FAMILY(any->Address.lpSockaddr->sa_family))
#endif
		rb_ary_push(list, sockaddr_obj(any->Address.lpSockaddr));
	}
    }

    FreeLibrary(h);
    return list;
#endif
}

.sockaddr_in(port, host) ⇒ Object .pack_sockaddr_in(port, host) ⇒ Object

Packs port and host as an AF_INET/AF_INET6 sockaddr string.

Socket.sockaddr_in(80, "127.0.0.1")
#=> "\x02\x00\x00P\x7F\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\x00"

Socket.sockaddr_in(80, "::1")
#=> "\n\x00\x00P\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00"



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# File 'socket.c', line 1304

static VALUE
sock_s_pack_sockaddr_in(VALUE self, VALUE port, VALUE host)
{
    struct addrinfo *res = rsock_addrinfo(host, port, 0, 0);
    VALUE addr = rb_str_new((char*)res->ai_addr, res->ai_addrlen);

    freeaddrinfo(res);
    OBJ_INFECT(addr, port);
    OBJ_INFECT(addr, host);

    return addr;
}

.sockaddr_un(path) ⇒ Object .pack_sockaddr_un(path) ⇒ Object

Packs path as an AF_UNIX sockaddr string.

Socket.sockaddr_un("/tmp/sock") #=> "\x01\x00/tmp/sock\x00\x00..."



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# File 'socket.c', line 1370

static VALUE
sock_s_pack_sockaddr_un(VALUE self, VALUE path)
{
    struct sockaddr_un sockaddr;
    char *sun_path;
    VALUE addr;

    MEMZERO(&sockaddr, struct sockaddr_un, 1);
    sockaddr.sun_family = AF_UNIX;
    sun_path = StringValueCStr(path);
    if (sizeof(sockaddr.sun_path) <= strlen(sun_path)) {
        rb_raise(rb_eArgError, "too long unix socket path (max: %dbytes)",
            (int)sizeof(sockaddr.sun_path)-1);
    }
    strncpy(sockaddr.sun_path, sun_path, sizeof(sockaddr.sun_path)-1);
    addr = rb_str_new((char*)&sockaddr, sizeof(sockaddr));
    OBJ_INFECT(addr, path);

    return addr;
}

.pair(domain, type, protocol) ⇒ Array .socketpair(domain, type, protocol) ⇒ Array

Creates a pair of sockets connected each other.

domain should be a communications domain such as: :INET, :INET6, :UNIX, etc.

socktype should be a socket type such as: :STREAM, :DGRAM, :RAW, etc.

protocol should be a protocol defined in the domain. 0 is default protocol for the domain.

s1, s2 = Socket.pair(:UNIX, :DGRAM, 0)
s1.send "a", 0
s1.send "b", 0
p s2.recv(10) #=> "a"
p s2.recv(10) #=> "b"

Overloads:

  • .pair(domain, type, protocol) ⇒ Array

    Returns:

    • (Array)
  • .socketpair(domain, type, protocol) ⇒ Array

    Returns:

    • (Array) 


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# File 'socket.c', line 100

VALUE
rsock_sock_s_socketpair(int argc, VALUE *argv, VALUE klass)
{
    VALUE domain, type, protocol;
    int d, t, p, sp[2];
    int ret;
    VALUE s1, s2, r;

    rb_scan_args(argc, argv, "21", &domain, &type, &protocol);
    if (NIL_P(protocol))
        protocol = INT2FIX(0);

    setup_domain_and_type(domain, &d, type, &t);
    p = NUM2INT(protocol);
    ret = socketpair(d, t, p, sp);
    if (ret < 0 && (errno == EMFILE || errno == ENFILE)) {
        rb_gc();
        ret = socketpair(d, t, p, sp);
    }
    if (ret < 0) {
	rb_sys_fail("socketpair(2)");
    }
    rb_update_max_fd(sp[0]);
    rb_update_max_fd(sp[1]);

    s1 = rsock_init_sock(rb_obj_alloc(klass), sp[0]);
    s2 = rsock_init_sock(rb_obj_alloc(klass), sp[1]);
    r = rb_assoc_new(s1, s2);
    if (rb_block_given_p()) {
        return rb_ensure(pair_yield, r, io_close, s1);
    }
    return r;
}

.sockaddr_in(port, host) ⇒ Object .pack_sockaddr_in(port, host) ⇒ Object

Packs port and host as an AF_INET/AF_INET6 sockaddr string.

Socket.sockaddr_in(80, "127.0.0.1")
#=> "\x02\x00\x00P\x7F\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\x00"

Socket.sockaddr_in(80, "::1")
#=> "\n\x00\x00P\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00"



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# File 'socket.c', line 1304

static VALUE
sock_s_pack_sockaddr_in(VALUE self, VALUE port, VALUE host)
{
    struct addrinfo *res = rsock_addrinfo(host, port, 0, 0);
    VALUE addr = rb_str_new((char*)res->ai_addr, res->ai_addrlen);

    freeaddrinfo(res);
    OBJ_INFECT(addr, port);
    OBJ_INFECT(addr, host);

    return addr;
}

.sockaddr_un(path) ⇒ Object .pack_sockaddr_un(path) ⇒ Object

Packs path as an AF_UNIX sockaddr string.

Socket.sockaddr_un("/tmp/sock") #=> "\x01\x00/tmp/sock\x00\x00..."



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# File 'socket.c', line 1370

static VALUE
sock_s_pack_sockaddr_un(VALUE self, VALUE path)
{
    struct sockaddr_un sockaddr;
    char *sun_path;
    VALUE addr;

    MEMZERO(&sockaddr, struct sockaddr_un, 1);
    sockaddr.sun_family = AF_UNIX;
    sun_path = StringValueCStr(path);
    if (sizeof(sockaddr.sun_path) <= strlen(sun_path)) {
        rb_raise(rb_eArgError, "too long unix socket path (max: %dbytes)",
            (int)sizeof(sockaddr.sun_path)-1);
    }
    strncpy(sockaddr.sun_path, sun_path, sizeof(sockaddr.sun_path)-1);
    addr = rb_str_new((char*)&sockaddr, sizeof(sockaddr));
    OBJ_INFECT(addr, path);

    return addr;
}

.pair(domain, type, protocol) ⇒ Array .socketpair(domain, type, protocol) ⇒ Array

Creates a pair of sockets connected each other.

domain should be a communications domain such as: :INET, :INET6, :UNIX, etc.

socktype should be a socket type such as: :STREAM, :DGRAM, :RAW, etc.

protocol should be a protocol defined in the domain. 0 is default protocol for the domain.

s1, s2 = Socket.pair(:UNIX, :DGRAM, 0)
s1.send "a", 0
s1.send "b", 0
p s2.recv(10) #=> "a"
p s2.recv(10) #=> "b"

Overloads:

  • .pair(domain, type, protocol) ⇒ Array

    Returns:

    • (Array)
  • .socketpair(domain, type, protocol) ⇒ Array

    Returns:

    • (Array) 


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# File 'socket.c', line 100

VALUE
rsock_sock_s_socketpair(int argc, VALUE *argv, VALUE klass)
{
    VALUE domain, type, protocol;
    int d, t, p, sp[2];
    int ret;
    VALUE s1, s2, r;

    rb_scan_args(argc, argv, "21", &domain, &type, &protocol);
    if (NIL_P(protocol))
        protocol = INT2FIX(0);

    setup_domain_and_type(domain, &d, type, &t);
    p = NUM2INT(protocol);
    ret = socketpair(d, t, p, sp);
    if (ret < 0 && (errno == EMFILE || errno == ENFILE)) {
        rb_gc();
        ret = socketpair(d, t, p, sp);
    }
    if (ret < 0) {
	rb_sys_fail("socketpair(2)");
    }
    rb_update_max_fd(sp[0]);
    rb_update_max_fd(sp[1]);

    s1 = rsock_init_sock(rb_obj_alloc(klass), sp[0]);
    s2 = rsock_init_sock(rb_obj_alloc(klass), sp[1]);
    r = rb_assoc_new(s1, s2);
    if (rb_block_given_p()) {
        return rb_ensure(pair_yield, r, io_close, s1);
    }
    return r;
}

.tcp(host, port, local_host = nil, local_port = nil) ⇒ Object

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.

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
}



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# File 'lib/socket.rb', line 236

def self.tcp(host, port, local_host=nil, local_port=nil) # :yield: socket
  last_error = nil
  ret = nil

  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) : ai.connect
    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

.tcp_server_loop(host = nil, port, &b) ⇒ Object

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
  }
}



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# File 'lib/socket.rb', line 466

def self.tcp_server_loop(host=nil, port, &b) # :yield: socket, client_addrinfo
  tcp_server_sockets(host, port) {|sockets|
    accept_loop(sockets, &b)
  }
end

.tcp_server_sockets(host = nil, port) ⇒ Object

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 choosen 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 choosen 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>]
}



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# File 'lib/socket.rb', line 364

def self.tcp_server_sockets(host=nil, port)
  if port == 0
    sockets = tcp_server_sockets_port0(host)
  else
    begin
      last_error = nil
      sockets = []
      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
    ensure
      sockets.each {|s| s.close if !s.closed? } if $!
    end
  end
  if block_given?
    begin
      yield sockets
    ensure
      sockets.each {|s| s.close if !s.closed? }
    end
  else
    sockets
  end
end

.udp_server_loop(host = nil, port, &b) ⇒ Object

: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
}



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# File 'lib/socket.rb', line 638

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_server_loop_on(sockets, &b) ⇒ Object

: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.



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# File 'lib/socket.rb', line 611

def self.udp_server_loop_on(sockets, &b) # :yield: msg, msg_src
  loop {
    readable, _, _ = IO.select(sockets)
    udp_server_recv(readable, &b)
  }
end

.udp_server_recv(sockets) ⇒ Object

: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| ... }
  }
}



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# File 'lib/socket.rb', line 581

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

.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 choosen. But the choosen 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 494

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

.unix(path) ⇒ Object

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
}



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# File 'lib/socket.rb', line 688

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

.unix_server_loop(path, &b) ⇒ Object

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
}



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# File 'lib/socket.rb', line 763

def self.unix_server_loop(path, &b) # :yield: socket, client_addrinfo
  unix_server_socket(path) {|serv|
    accept_loop(serv, &b)
  }
end

.unix_server_socket(path) ⇒ Object

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>
}



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# File 'lib/socket.rb', line 718

def self.unix_server_socket(path)
  begin
    st = File.lstat(path)
  rescue Errno::ENOENT
  end
  if st && st.socket? && st.owned?
    File.unlink path
  end
  s = Addrinfo.unix(path).listen
  if block_given?
    begin
      yield s
    ensure
      s.close if !s.closed?
      File.unlink path
    end
  else
    s
  end
end

.unpack_sockaddr_in(sockaddr) ⇒ Array

Unpacks sockaddr into port and ip_address.

sockaddr should be a string or an addrinfo for AF_INET/AF_INET6.

sockaddr = Socket.sockaddr_in(80, "127.0.0.1")
p sockaddr #=> "\x02\x00\x00P\x7F\x00\x00\x01\x00\x00\x00\x00\x00\x00\x00\x00"
p Socket.unpack_sockaddr_in(sockaddr) #=> [80, "127.0.0.1"]

Returns:

  • (Array) 


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# File 'socket.c', line 1330

static VALUE
sock_s_unpack_sockaddr_in(VALUE self, VALUE addr)
{
    struct sockaddr_in * sockaddr;
    VALUE host;

    sockaddr = (struct sockaddr_in*)SockAddrStringValuePtr(addr);
    if (RSTRING_LEN(addr) <
        (char*)&((struct sockaddr *)sockaddr)->sa_family +
        sizeof(((struct sockaddr *)sockaddr)->sa_family) -
        (char*)sockaddr)
        rb_raise(rb_eArgError, "too short sockaddr");
    if (((struct sockaddr *)sockaddr)->sa_family != AF_INET
#ifdef INET6
        && ((struct sockaddr *)sockaddr)->sa_family != AF_INET6
#endif
        ) {
#ifdef INET6
        rb_raise(rb_eArgError, "not an AF_INET/AF_INET6 sockaddr");
#else
        rb_raise(rb_eArgError, "not an AF_INET sockaddr");
#endif
    }
    host = rsock_make_ipaddr((struct sockaddr*)sockaddr);
    OBJ_INFECT(host, addr);
    return rb_assoc_new(INT2NUM(ntohs(sockaddr->sin_port)), host);
}

.unpack_sockaddr_un(sockaddr) ⇒ Object

Unpacks sockaddr into path.

sockaddr should be a string or an addrinfo for AF_UNIX.

sockaddr = Socket.sockaddr_un("/tmp/sock")
p Socket.unpack_sockaddr_un(sockaddr) #=> "/tmp/sock"



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# File 'socket.c', line 1403

static VALUE
sock_s_unpack_sockaddr_un(VALUE self, VALUE addr)
{
    struct sockaddr_un * sockaddr;
    const char *sun_path;
    VALUE path;

    sockaddr = (struct sockaddr_un*)SockAddrStringValuePtr(addr);
    if (RSTRING_LEN(addr) <
        (char*)&((struct sockaddr *)sockaddr)->sa_family +
        sizeof(((struct sockaddr *)sockaddr)->sa_family) -
        (char*)sockaddr)
        rb_raise(rb_eArgError, "too short sockaddr");
    if (((struct sockaddr *)sockaddr)->sa_family != AF_UNIX) {
        rb_raise(rb_eArgError, "not an AF_UNIX sockaddr");
    }
    if (sizeof(struct sockaddr_un) < (size_t)RSTRING_LEN(addr)) {
	rb_raise(rb_eTypeError, "too long sockaddr_un - %ld longer than %d",
		 RSTRING_LEN(addr), (int)sizeof(struct sockaddr_un));
    }
    sun_path = rsock_unixpath(sockaddr, RSTRING_LENINT(addr));
    if (sizeof(struct sockaddr_un) == RSTRING_LEN(addr) &&
        sun_path == sockaddr->sun_path &&
        sun_path + strlen(sun_path) == RSTRING_PTR(addr) + RSTRING_LEN(addr)) {
        rb_raise(rb_eArgError, "sockaddr_un.sun_path not NUL terminated");
    }
    path = rb_str_new2(sun_path);
    OBJ_INFECT(path, addr);
    return path;
}

Instance Method Details

#accept ⇒ Array

Accepts a next connection. Returns a new Socket object and Addrinfo object.

serv = Socket.new(:INET, :STREAM, 0)
serv.listen(5)
c = Socket.new(:INET, :STREAM, 0)
c.connect(serv.connect_address)
p serv.accept #=> [#<Socket:fd 6>, #<Addrinfo: 127.0.0.1:48555 TCP>]

Returns:

  • (Array) 


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# File 'socket.c', line 705

static VALUE
sock_accept(VALUE sock)
{
    rb_io_t *fptr;
    VALUE sock2;
    struct sockaddr_storage buf;
    socklen_t len = (socklen_t)sizeof buf;

    GetOpenFile(sock, fptr);
    sock2 = rsock_s_accept(rb_cSocket,fptr->fd,(struct sockaddr*)&buf,&len);

    return rb_assoc_new(sock2, rsock_io_socket_addrinfo(sock2, (struct sockaddr*)&buf, len));
}

#accept_nonblock ⇒ Array

Accepts an incoming connection using accept(2) after O_NONBLOCK is set for the underlying file descriptor. It returns an array containing the accepted socket for the incoming connection, client_socket, and an Addrinfo, client_addrinfo.

Example

# In one script, start this first require 'socket' include Socket::Constants socket = Socket.new(AF_INET, SOCK_STREAM, 0) sockaddr = Socket.sockaddr_in(2200, 'localhost') socket.bind(sockaddr) socket.listen(5) begin # emulate blocking accept client_socket, client_addrinfo = socket.accept_nonblock rescue IO::WaitReadable, Errno::EINTR IO.select() retry end puts "The client said, '#Socket.client_socketclient_socket.readlineclient_socket.readline.chomp'" client_socket.puts "Hello from script one!" socket.close

# In another script, start this second require 'socket' include Socket::Constants socket = Socket.new(AF_INET, SOCK_STREAM, 0) sockaddr = Socket.sockaddr_in(2200, 'localhost') socket.connect(sockaddr) socket.puts "Hello from script 2." puts "The server said, '#Socket.socketsocket.readlinesocket.readline.chomp'" socket.close

Refer to Socket#accept for the exceptions that may be thrown if the call to accept_nonblock fails.

Socket#accept_nonblock may raise any error corresponding to accept(2) failure, including Errno::EWOULDBLOCK.

If the exception is Errno::EWOULDBLOCK, Errno::AGAIN, Errno::ECONNABORTED or Errno::EPROTO, it is extended by IO::WaitReadable. So IO::WaitReadable can be used to rescue the exceptions for retrying accept_nonblock.

See

  • Socket#accept

Returns:

  • (Array) 


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# File 'socket.c', line 770

static VALUE
sock_accept_nonblock(VALUE sock)
{
    rb_io_t *fptr;
    VALUE sock2;
    struct sockaddr_storage buf;
    socklen_t len = (socklen_t)sizeof buf;

    GetOpenFile(sock, fptr);
    sock2 = rsock_s_accept_nonblock(rb_cSocket, fptr, (struct sockaddr *)&buf, &len);
    return rb_assoc_new(sock2, rsock_io_socket_addrinfo(sock2, (struct sockaddr*)&buf, len));
}

#bind(local_sockaddr) ⇒ 0

Binds to the given local address.

Parameter

  • local_sockaddr - the struct sockaddr contained in a string or an Addrinfo object

Example

require 'socket'

# use Addrinfo socket = Socket.new(:INET, :STREAM, 0) socket.bind(Addrinfo.tcp("127.0.0.1", 2222)) p socket.local_address #=> #<Addrinfo: 127.0.0.1:2222 TCP>

# use struct sockaddr include Socket::Constants socket = Socket.new( AF_INET, SOCK_STREAM, 0 ) sockaddr = Socket.pack_sockaddr_in( 2200, 'localhost' ) socket.bind( sockaddr )

Unix-based Exceptions

On unix-based based systems the following system exceptions may be raised if the call to bind fails:

  • Errno::EACCES - the specified sockaddr is protected and the current user does not have permission to bind to it

  • Errno::EADDRINUSE - the specified sockaddr is already in use

  • Errno::EADDRNOTAVAIL - the specified sockaddr is not available from the local machine

  • Errno::EAFNOSUPPORT - the specified sockaddr is not a valid address for the family of the calling socket

  • Errno::EBADF - the sockaddr specified is not a valid file descriptor

  • Errno::EFAULT - the sockaddr argument cannot be accessed

  • Errno::EINVAL - the socket is already bound to an address, and the protocol does not support binding to the new sockaddr or the socket has been shut down.

  • Errno::EINVAL - the address length is not a valid length for the address family

  • Errno::ENAMETOOLONG - the pathname resolved had a length which exceeded PATH_MAX

  • Errno::ENOBUFS - no buffer space is available

  • Errno::ENOSR - there were insufficient STREAMS resources available to complete the operation

  • Errno::ENOTSOCK - the socket does not refer to a socket

  • Errno::EOPNOTSUPP - the socket type of the socket does not support binding to an address

On unix-based based systems if the address family of the calling socket is Socket::AF_UNIX the follow exceptions may be raised if the call to bind fails:

  • Errno::EACCES - search permission is denied for a component of the prefix path or write access to the socket is denied

  • Errno::EDESTADDRREQ - the sockaddr argument is a null pointer

  • Errno::EISDIR - same as Errno::EDESTADDRREQ

  • Errno::EIO - an i/o error occurred

  • Errno::ELOOP - too many symbolic links were encountered in translating the pathname in sockaddr

  • Errno::ENAMETOOLLONG - a component of a pathname exceeded NAME_MAX characters, or an entire pathname exceeded PATH_MAX characters

  • Errno::ENOENT - a component of the pathname does not name an existing file or the pathname is an empty string

  • Errno::ENOTDIR - a component of the path prefix of the pathname in sockaddr is not a directory

  • Errno::EROFS - the name would reside on a read only filesystem

Windows Exceptions

On Windows systems the following system exceptions may be raised if the call to bind fails:

  • Errno::ENETDOWN-- the network is down

  • Errno::EACCES - the attempt to connect the datagram socket to the broadcast address failed

  • Errno::EADDRINUSE - the socket's local address is already in use

  • Errno::EADDRNOTAVAIL - the specified address is not a valid address for this computer

  • Errno::EFAULT - the socket's internal address or address length parameter is too small or is not a valid part of the user space addressed

  • Errno::EINVAL - the socket is already bound to an address

  • Errno::ENOBUFS - no buffer space is available

  • Errno::ENOTSOCK - the socket argument does not refer to a socket

See

  • bind manual pages on unix-based systems

  • bind function in Microsoft's Winsock functions reference

Returns:

  • (0) 


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# File 'socket.c', line 414

static VALUE
sock_bind(VALUE sock, VALUE addr)
{
    rb_io_t *fptr;

    SockAddrStringValue(addr);
    GetOpenFile(sock, fptr);
    if (bind(fptr->fd, (struct sockaddr*)RSTRING_PTR(addr), RSTRING_LENINT(addr)) < 0)
	rb_sys_fail("bind(2)");

    return INT2FIX(0);
}

#connect(remote_sockaddr) ⇒ 0

Requests a connection to be made on the given remote_sockaddr. Returns 0 if successful, otherwise an exception is raised.

Parameter

  • remote_sockaddr - the struct sockaddr contained in a string or Addrinfo object

Example:

# Pull down Google's web page require 'socket' include Socket::Constants socket = Socket.new( AF_INET, SOCK_STREAM, 0 ) sockaddr = Socket.pack_sockaddr_in( 80, 'www.google.com' ) socket.connect( sockaddr ) socket.write( "GET / HTTP/1.0rnrn" ) results = socket.read

Unix-based Exceptions

On unix-based systems the following system exceptions may be raised if the call to connect fails:

  • Errno::EACCES - search permission is denied for a component of the prefix path or write access to the socket is denied

  • Errno::EADDRINUSE - the sockaddr is already in use

  • Errno::EADDRNOTAVAIL - the specified sockaddr is not available from the local machine

  • Errno::EAFNOSUPPORT - the specified sockaddr is not a valid address for the address family of the specified socket

  • Errno::EALREADY - a connection is already in progress for the specified socket

  • Errno::EBADF - the socket is not a valid file descriptor

  • Errno::ECONNREFUSED - the target sockaddr was not listening for connections refused the connection request

  • Errno::ECONNRESET - the remote host reset the connection request

  • Errno::EFAULT - the sockaddr cannot be accessed

  • Errno::EHOSTUNREACH - the destination host cannot be reached (probably because the host is down or a remote router cannot reach it)

  • Errno::EINPROGRESS - the O_NONBLOCK is set for the socket and the connection cannot be immediately established; the connection will be established asynchronously

  • Errno::EINTR - the attempt to establish the connection was interrupted by delivery of a signal that was caught; the connection will be established asynchronously

  • Errno::EISCONN - the specified socket is already connected

  • Errno::EINVAL - the address length used for the sockaddr is not a valid length for the address family or there is an invalid family in sockaddr

  • Errno::ENAMETOOLONG - the pathname resolved had a length which exceeded PATH_MAX

  • Errno::ENETDOWN - the local interface used to reach the destination is down

  • Errno::ENETUNREACH - no route to the network is present

  • Errno::ENOBUFS - no buffer space is available

  • Errno::ENOSR - there were insufficient STREAMS resources available to complete the operation

  • Errno::ENOTSOCK - the socket argument does not refer to a socket

  • Errno::EOPNOTSUPP - the calling socket is listening and cannot be connected

  • Errno::EPROTOTYPE - the sockaddr has a different type than the socket bound to the specified peer address

  • Errno::ETIMEDOUT - the attempt to connect time out before a connection was made.

On unix-based systems if the address family of the calling socket is AF_UNIX the follow exceptions may be raised if the call to connect fails:

  • Errno::EIO - an i/o error occurred while reading from or writing to the file system

  • Errno::ELOOP - too many symbolic links were encountered in translating the pathname in sockaddr

  • Errno::ENAMETOOLLONG - a component of a pathname exceeded NAME_MAX characters, or an entire pathname exceeded PATH_MAX characters

  • Errno::ENOENT - a component of the pathname does not name an existing file or the pathname is an empty string

  • Errno::ENOTDIR - a component of the path prefix of the pathname in sockaddr is not a directory

Windows Exceptions

On Windows systems the following system exceptions may be raised if the call to connect fails:

  • Errno::ENETDOWN - the network is down

  • Errno::EADDRINUSE - the socket's local address is already in use

  • Errno::EINTR - the socket was cancelled

  • Errno::EINPROGRESS - a blocking socket is in progress or the service provider is still processing a callback function. Or a nonblocking connect call is in progress on the socket.

  • Errno::EALREADY - see Errno::EINVAL

  • Errno::EADDRNOTAVAIL - the remote address is not a valid address, such as ADDR_ANY TODO check ADDRANY TO INADDR_ANY

  • Errno::EAFNOSUPPORT - addresses in the specified family cannot be used with with this socket

  • Errno::ECONNREFUSED - the target sockaddr was not listening for connections refused the connection request

  • Errno::EFAULT - the socket's internal address or address length parameter is too small or is not a valid part of the user space address

  • Errno::EINVAL - the socket is a listening socket

  • Errno::EISCONN - the socket is already connected

  • Errno::ENETUNREACH - the network cannot be reached from this host at this time

  • Errno::EHOSTUNREACH - no route to the network is present

  • Errno::ENOBUFS - no buffer space is available

  • Errno::ENOTSOCK - the socket argument does not refer to a socket

  • Errno::ETIMEDOUT - the attempt to connect time out before a connection was made.

  • Errno::EWOULDBLOCK - the socket is marked as nonblocking and the connection cannot be completed immediately

  • Errno::EACCES - the attempt to connect the datagram socket to the broadcast address failed

See

  • connect manual pages on unix-based systems

  • connect function in Microsoft's Winsock functions reference

Returns:

  • (0) 


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# File 'socket.c', line 248

static VALUE
sock_connect(VALUE sock, VALUE addr)
{
    rb_io_t *fptr;
    int fd, n;

    SockAddrStringValue(addr);
    addr = rb_str_new4(addr);
    GetOpenFile(sock, fptr);
    fd = fptr->fd;
    n = rsock_connect(fd, (struct sockaddr*)RSTRING_PTR(addr), RSTRING_LENINT(addr), 0);
    if (n < 0) {
	rb_sys_fail("connect(2)");
    }

    return INT2FIX(n);
}

#connect_nonblock(remote_sockaddr) ⇒ 0

Requests a connection to be made on the given remote_sockaddr after O_NONBLOCK is set for the underlying file descriptor. Returns 0 if successful, otherwise an exception is raised.

Parameter

  • remote_sockaddr - the struct sockaddr contained in a string or Addrinfo object

Example:

# Pull down Google's web page require 'socket' include Socket::Constants socket = Socket.new(AF_INET, SOCK_STREAM, 0) sockaddr = Socket.sockaddr_in(80, 'www.google.com') begin # emulate blocking connect socket.connect_nonblock(sockaddr) rescue IO::WaitWritable IO.select(nil, [socket]) # wait 3-way handshake completion begin socket.connect_nonblock(sockaddr) # check connection failure rescue Errno::EISCONN end end socket.write("GET / HTTP/1.0rnrn") results = socket.read

Refer to Socket#connect for the exceptions that may be thrown if the call to connect_nonblock fails.

Socket#connect_nonblock may raise any error corresponding to connect(2) failure, including Errno::EINPROGRESS.

If the exception is Errno::EINPROGRESS, it is extended by IO::WaitWritable. So IO::WaitWritable can be used to rescue the exceptions for retrying connect_nonblock.

See

  • Socket#connect

Returns:

  • (0) 


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# File 'socket.c', line 308

static VALUE
sock_connect_nonblock(VALUE sock, VALUE addr)
{
    rb_io_t *fptr;
    int n;

    SockAddrStringValue(addr);
    addr = rb_str_new4(addr);
    GetOpenFile(sock, fptr);
    rb_io_set_nonblock(fptr);
    n = connect(fptr->fd, (struct sockaddr*)RSTRING_PTR(addr), RSTRING_LENINT(addr));
    if (n < 0) {
        if (errno == EINPROGRESS)
            rb_mod_sys_fail(rb_mWaitWritable, "connect(2) would block");
	rb_sys_fail("connect(2)");
    }

    return INT2FIX(n);
}

#ipv6only! ⇒ Object

enable the socket option IPV6_V6ONLY if IPV6_V6ONLY is available.



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# File 'lib/socket.rb', line 213

def ipv6only!
  if defined? Socket::IPV6_V6ONLY
    self.setsockopt(:IPV6, :V6ONLY, 1)
  end
end

#listen(int) ⇒ 0

Listens for connections, using the specified int as the backlog. A call to listen only applies if the socket is of type SOCK_STREAM or SOCK_SEQPACKET.

Parameter

  • backlog - the maximum length of the queue for pending connections.

Example 1

require 'socket' include Socket::Constants socket = Socket.new( AF_INET, SOCK_STREAM, 0 ) sockaddr = Socket.pack_sockaddr_in( 2200, 'localhost' ) socket.bind( sockaddr ) socket.listen( 5 )

Example 2 (listening on an arbitrary port, unix-based systems only):

require 'socket' include Socket::Constants socket = Socket.new( AF_INET, SOCK_STREAM, 0 ) socket.listen( 1 )

Unix-based Exceptions

On unix based systems the above will work because a new sockaddr struct is created on the address ADDR_ANY, for an arbitrary port number as handed off by the kernel. It will not work on Windows, because Windows requires that the socket is bound by calling bind before it can listen.

If the backlog amount exceeds the implementation-dependent maximum queue length, the implementation's maximum queue length will be used.

On unix-based based systems the following system exceptions may be raised if the call to listen fails:

  • Errno::EBADF - the socket argument is not a valid file descriptor

  • Errno::EDESTADDRREQ - the socket is not bound to a local address, and the protocol does not support listening on an unbound socket

  • Errno::EINVAL - the socket is already connected

  • Errno::ENOTSOCK - the socket argument does not refer to a socket

  • Errno::EOPNOTSUPP - the socket protocol does not support listen

  • Errno::EACCES - the calling process does not have appropriate privileges

  • Errno::EINVAL - the socket has been shut down

  • Errno::ENOBUFS - insufficient resources are available in the system to complete the call

Windows Exceptions

On Windows systems the following system exceptions may be raised if the call to listen fails:

  • Errno::ENETDOWN - the network is down

  • Errno::EADDRINUSE - the socket's local address is already in use. This usually occurs during the execution of bind but could be delayed if the call to bind was to a partially wildcard address (involving ADDR_ANY) and if a specific address needs to be committed at the time of the call to listen

  • Errno::EINPROGRESS - a Windows Sockets 1.1 call is in progress or the service provider is still processing a callback function

  • Errno::EINVAL - the socket has not been bound with a call to bind.

  • Errno::EISCONN - the socket is already connected

  • Errno::EMFILE - no more socket descriptors are available

  • Errno::ENOBUFS - no buffer space is available

  • Errno::ENOTSOC - socket is not a socket

  • Errno::EOPNOTSUPP - the referenced socket is not a type that supports the listen method

See

  • listen manual pages on unix-based systems

  • listen function in Microsoft's Winsock functions reference

Returns:

  • (0) 


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# File 'socket.c', line 497

VALUE
rsock_sock_listen(VALUE sock, VALUE log)
{
    rb_io_t *fptr;
    int backlog;

    rb_secure(4);
    backlog = NUM2INT(log);
    GetOpenFile(sock, fptr);
    if (listen(fptr->fd, backlog) < 0)
	rb_sys_fail("listen(2)");

    return INT2FIX(0);
}

#recvfrom(maxlen) ⇒ Array #recvfrom(maxlen, flags) ⇒ Array

Receives up to maxlen bytes from socket. flags is zero or more of the MSG_ options. The first element of the results, mesg, is the data received. The second element, sender_addrinfo, contains protocol-specific address information of the sender.

Parameters

  • maxlen - the maximum number of bytes to receive from the socket

  • flags - zero or more of the MSG_ options

Example

# In one file, start this first require 'socket' include Socket::Constants socket = Socket.new( AF_INET, SOCK_STREAM, 0 ) sockaddr = Socket.pack_sockaddr_in( 2200, 'localhost' ) socket.bind( sockaddr ) socket.listen( 5 ) client, client_addrinfo = socket.accept data = client.recvfrom( 20 )[0].chomp puts "I only received 20 bytes '#data'" sleep 1 socket.close

# In another file, start this second require 'socket' include Socket::Constants socket = Socket.new( AF_INET, SOCK_STREAM, 0 ) sockaddr = Socket.pack_sockaddr_in( 2200, 'localhost' ) socket.connect( sockaddr ) socket.puts "Watch this get cut short!" socket.close

Unix-based Exceptions

On unix-based based systems the following system exceptions may be raised if the call to recvfrom fails:

  • Errno::EAGAIN - the socket file descriptor is marked as O_NONBLOCK and no data is waiting to be received; or MSG_OOB is set and no out-of-band data is available and either the socket file descriptor is marked as O_NONBLOCK or the socket does not support blocking to wait for out-of-band-data

  • Errno::EWOULDBLOCK - see Errno::EAGAIN

  • Errno::EBADF - the socket is not a valid file descriptor

  • Errno::ECONNRESET - a connection was forcibly closed by a peer

  • Errno::EFAULT - the socket's internal buffer, address or address length cannot be accessed or written

  • Errno::EINTR - a signal interrupted recvfrom before any data was available

  • Errno::EINVAL - the MSG_OOB flag is set and no out-of-band data is available

  • Errno::EIO - an i/o error occurred while reading from or writing to the filesystem

  • Errno::ENOBUFS - insufficient resources were available in the system to perform the operation

  • Errno::ENOMEM - insufficient memory was available to fulfill the request

  • Errno::ENOSR - there were insufficient STREAMS resources available to complete the operation

  • Errno::ENOTCONN - a receive is attempted on a connection-mode socket that is not connected

  • Errno::ENOTSOCK - the socket does not refer to a socket

  • Errno::EOPNOTSUPP - the specified flags are not supported for this socket type

  • Errno::ETIMEDOUT - the connection timed out during connection establishment or due to a transmission timeout on an active connection

Windows Exceptions

On Windows systems the following system exceptions may be raised if the call to recvfrom fails:

  • Errno::ENETDOWN - the network is down

  • Errno::EFAULT - the internal buffer and from parameters on socket are not part of the user address space, or the internal fromlen parameter is too small to accommodate the peer address

  • Errno::EINTR - the (blocking) call was cancelled by an internal call to the WinSock function WSACancelBlockingCall

  • Errno::EINPROGRESS - a blocking Windows Sockets 1.1 call is in progress or the service provider is still processing a callback function

  • Errno::EINVAL - socket has not been bound with a call to bind, or an unknown flag was specified, or MSG_OOB was specified for a socket with SO_OOBINLINE enabled, or (for byte stream-style sockets only) the internal len parameter on socket was zero or negative

  • Errno::EISCONN - socket is already connected. The call to recvfrom is not permitted with a connected socket on a socket that is connection oriented or connectionless.

  • Errno::ENETRESET - the connection has been broken due to the keep-alive activity detecting a failure while the operation was in progress.

  • Errno::EOPNOTSUPP - MSG_OOB was specified, but socket is not stream-style such as type SOCK_STREAM. OOB data is not supported in the communication domain associated with socket, or socket is unidirectional and supports only send operations

  • Errno::ESHUTDOWN - socket has been shutdown. It is not possible to call recvfrom on a socket after shutdown has been invoked.

  • Errno::EWOULDBLOCK - socket is marked as nonblocking and a call to recvfrom would block.

  • Errno::EMSGSIZE - the message was too large to fit into the specified buffer and was truncated.

  • Errno::ETIMEDOUT - the connection has been dropped, because of a network failure or because the system on the other end went down without notice

  • Errno::ECONNRESET - the virtual circuit was reset by the remote side executing a hard or abortive close. The application should close the socket; it is no longer usable. On a UDP-datagram socket this error indicates a previous send operation resulted in an ICMP Port Unreachable message.

Overloads:

  • #recvfrom(maxlen) ⇒ Array

    Returns:

    • (Array)
  • #recvfrom(maxlen, flags) ⇒ Array

    Returns:

    • (Array) 


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# File 'socket.c', line 617

static VALUE
sock_recvfrom(int argc, VALUE *argv, VALUE sock)
{
    return rsock_s_recvfrom(sock, argc, argv, RECV_SOCKET);
}

#recvfrom_nonblock(maxlen) ⇒ Array #recvfrom_nonblock(maxlen, flags) ⇒ Array

Receives up to maxlen bytes from socket using recvfrom(2) after O_NONBLOCK is set for the underlying file descriptor. flags is zero or more of the MSG_ options. The first element of the results, mesg, is the data received. The second element, sender_addrinfo, contains protocol-specific address information of the sender.

When recvfrom(2) returns 0, Socket#recvfrom_nonblock returns an empty string as data. The meaning depends on the socket: EOF on TCP, empty packet on UDP, etc.

Parameters

  • maxlen - the maximum number of bytes to receive from the socket

  • flags - zero or more of the MSG_ options

Example

# In one file, start this first require 'socket' include Socket::Constants socket = Socket.new(AF_INET, SOCK_STREAM, 0) sockaddr = Socket.sockaddr_in(2200, 'localhost') socket.bind(sockaddr) socket.listen(5) client, client_addrinfo = socket.accept begin # emulate blocking recvfrom pair = client.recvfrom_nonblock(20) rescue IO::WaitReadable IO.select() retry end data = pair.chomp puts "I only received 20 bytes '#data'" sleep 1 socket.close

# In another file, start this second require 'socket' include Socket::Constants socket = Socket.new(AF_INET, SOCK_STREAM, 0) sockaddr = Socket.sockaddr_in(2200, 'localhost') socket.connect(sockaddr) socket.puts "Watch this get cut short!" socket.close

Refer to Socket#recvfrom for the exceptions that may be thrown if the call to recvfrom_nonblock fails.

Socket#recvfrom_nonblock may raise any error corresponding to recvfrom(2) failure, including Errno::EWOULDBLOCK.

If the exception is Errno::EWOULDBLOCK or Errno::AGAIN, it is extended by IO::WaitReadable. So IO::WaitReadable can be used to rescue the exceptions for retrying recvfrom_nonblock.

See

  • Socket#recvfrom

Overloads:

  • #recvfrom_nonblock(maxlen) ⇒ Array

    Returns:

    • (Array)
  • #recvfrom_nonblock(maxlen, flags) ⇒ Array

    Returns:

    • (Array) 


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# File 'socket.c', line 685

static VALUE
sock_recvfrom_nonblock(int argc, VALUE *argv, VALUE sock)
{
    return rsock_s_recvfrom_nonblock(sock, argc, argv, RECV_SOCKET);
}

#sysaccept ⇒ Array

Accepts an incoming connection returning an array containing the (integer) file descriptor for the incoming connection, client_socket_fd, and an Addrinfo, client_addrinfo.

Example

# In one script, start this first require 'socket' include Socket::Constants socket = Socket.new( AF_INET, SOCK_STREAM, 0 ) sockaddr = Socket.pack_sockaddr_in( 2200, 'localhost' ) socket.bind( sockaddr ) socket.listen( 5 ) client_fd, client_addrinfo = socket.sysaccept client_socket = Socket.for_fd( client_fd ) puts "The client said, '#Socket.client_socketclient_socket.readlineclient_socket.readline.chomp'" client_socket.puts "Hello from script one!" socket.close

# In another script, start this second require 'socket' include Socket::Constants socket = Socket.new( AF_INET, SOCK_STREAM, 0 ) sockaddr = Socket.pack_sockaddr_in( 2200, 'localhost' ) socket.connect( sockaddr ) socket.puts "Hello from script 2." puts "The server said, '#Socket.socketsocket.readlinesocket.readline.chomp'" socket.close

Refer to Socket#accept for the exceptions that may be thrown if the call to sysaccept fails.

See

  • Socket#accept

Returns:

  • (Array) 


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# File 'socket.c', line 821

static VALUE
sock_sysaccept(VALUE sock)
{
    rb_io_t *fptr;
    VALUE sock2;
    struct sockaddr_storage buf;
    socklen_t len = (socklen_t)sizeof buf;

    GetOpenFile(sock, fptr);
    sock2 = rsock_s_accept(0,fptr->fd,(struct sockaddr*)&buf,&len);

    return rb_assoc_new(sock2, rsock_io_socket_addrinfo(sock2, (struct sockaddr*)&buf, len));
}