class Socket
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 bidirectional 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:
type: The type of communications between the two endpoints, typically
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 address or
broadcast
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¶ ↑
Many of the classes, such as TCPSocket
, UDPSocket
or UNIXSocket
, ease the use of sockets comparatively to the equivalent C programming interface.
Let’s create an internet socket using the IPv4 protocol in a C-like manner:
require 'socket' s = Socket.new Socket::AF_INET, Socket::SOCK_STREAM s.connect Socket.pack_sockaddr_in(80, 'example.com')
You could also use the TCPSocket
class:
s = TCPSocket.new 'example.com', 80
A simple server might look like this:
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 this:
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 a particular exception is needed, please refer to the Unix manual pages or the Windows WinSock reference.
Convenience methods¶ ↑
Although the general way to create socket is Socket.new
, there are several methods of 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.
Constants
- AF_ALG
Interface to kernel crypto API
- AF_APPLETALK
AppleTalk protocol
- AF_ATM
Asynchronous Transfer Mode
- AF_AX25
AX.25 protocol
- AF_BLUETOOTH
Bluetooth low-level socket protocol
- AF_CAN
Controller Area Network automotive bus protocol
- AF_CCITT
CCITT (now ITU-T) protocols
- AF_CHAOS
MIT CHAOS protocols
- AF_CNT
Computer Network Technology
- AF_COIP
Connection-oriented IP
- AF_DATAKIT
Datakit protocol
- AF_DEC
DECnet protocol
- AF_DECnet
DECnet protocol
- AF_DLI
DEC Direct Data Link Interface protocol
- AF_E164
CCITT (ITU-T) E.164 recommendation
- AF_ECMA
European Computer Manufacturers protocols
- AF_HYLINK
NSC Hyperchannel protocol
- AF_IB
InfiniBand native addressing
- AF_IMPLINK
ARPANET IMP protocol
- AF_INET
IPv4 protocol
- AF_INET6
IPv6 protocol
- AF_IPX
IPX protocol
- AF_ISDN
Integrated Services Digital Network
- AF_ISO
ISO Open Systems Interconnection protocols
- AF_KCM
KCM (kernel connection multiplexor) interface
- AF_KEY
Key management protocol, originally developed for usage with IPsec
- AF_LAT
Local Area Transport protocol
- AF_LINK
Link layer interface
- AF_LLC
Logical link control (IEEE 802.2 LLC) protocol
- AF_LOCAL
Host-internal protocols
- AF_MAX
Maximum address family for this platform
- AF_MPLS
Multiprotocol Label Switching
- AF_NATM
Native ATM access
- AF_NDRV
Network driver raw access
- AF_NETBIOS
NetBIOS
- AF_NETGRAPH
Netgraph sockets
- AF_NETLINK
Kernel user interface device
- AF_NS
XEROX NS protocols
- AF_OSI
ISO Open Systems Interconnection protocols
- AF_PACKET
Direct link-layer access
- AF_PPP
Point-to-Point Protocol
- AF_PPPOX
Generic PPP transport layer, for setting up L2 tunnels (L2TP and PPPoE)
- AF_PUP
PARC Universal Packet protocol
- AF_RDS
Reliable Datagram Sockets (RDS) protocol
- AF_ROUTE
Internal routing protocol
- AF_SIP
Simple Internet Protocol
- AF_SNA
IBM SNA protocol
- AF_SYSTEM
Kernel event messages
- AF_TIPC
TIPC, “cluster domain sockets” protocol
- AF_UNIX
UNIX sockets
- AF_UNSPEC
Unspecified protocol, any supported address family
- AF_VSOCK
VSOCK (originally “VMWare VSockets”) protocol for hypervisor-guest communication
- AF_XDP
XDP (express data path) interface
- AI_ADDRCONFIG
Accept only if any address is assigned
- AI_ALL
Allow all addresses
- AI_CANONNAME
Fill in the canonical name
- AI_DEFAULT
Default flags for getaddrinfo
- AI_MASK
Valid flag mask for getaddrinfo (not for application use)
- AI_NUMERICHOST
Prevent host name resolution
- AI_NUMERICSERV
Prevent service name resolution
- AI_PASSIVE
Get address to use with bind()
- AI_V4MAPPED
Accept IPv4-mapped IPv6 addresses
- AI_V4MAPPED_CFG
Accept IPv4 mapped addresses if the kernel supports it
- EAI_ADDRFAMILY
Address family for hostname not supported
- EAI_AGAIN
Temporary failure in name resolution
- EAI_BADFLAGS
Invalid flags
- EAI_BADHINTS
Invalid value for hints
- EAI_FAIL
Non-recoverable failure in name resolution
- EAI_FAMILY
Address family not supported
- EAI_MAX
Maximum error code from getaddrinfo
- EAI_MEMORY
Memory allocation failure
- EAI_NODATA
No address associated with hostname
- EAI_NONAME
Hostname nor servname, or not known
- EAI_OVERFLOW
Argument buffer overflow
- EAI_PROTOCOL
Resolved protocol is unknown
- EAI_SERVICE
Servname not supported for socket type
- EAI_SOCKTYPE
Socket type not supported
- EAI_SYSTEM
System error returned in errno
- IFF_802_1Q_VLAN
802.1Q VLAN device
- IFF_ALLMULTI
receive all multicast packets
- IFF_ALTPHYS
use alternate physical connection
- IFF_AUTOMEDIA
auto media select active
- IFF_BONDING
bonding master or slave
- IFF_BRIDGE_PORT
device used as bridge port
- IFF_BROADCAST
broadcast address valid
- IFF_CANTCHANGE
flags not changeable
- IFF_CANTCONFIG
unconfigurable using ioctl(2)
- IFF_DEBUG
turn on debugging
- IFF_DISABLE_NETPOLL
disable netpoll at run-time
- IFF_DONT_BRIDGE
disallow bridging this ether dev
- IFF_DORMANT
driver signals dormant
- IFF_DRV_OACTIVE
tx hardware queue is full
- IFF_DRV_RUNNING
resources allocated
- IFF_DYING
interface is winding down
- IFF_DYNAMIC
dialup device with changing addresses
- IFF_EBRIDGE
ethernet bridging device
- IFF_ECHO
echo sent packets
- IFF_ISATAP
ISATAP interface (RFC4214)
- IFF_LINK0
per link layer defined bit 0
- IFF_LINK1
per link layer defined bit 1
- IFF_LINK2
per link layer defined bit 2
- IFF_LIVE_ADDR_CHANGE
hardware address change when it’s running
- IFF_LOOPBACK
loopback net
- IFF_LOWER_UP
driver signals L1 up
- IFF_MACVLAN_PORT
device used as macvlan port
- IFF_MASTER
master of a load balancer
- IFF_MASTER_8023AD
bonding master, 802.3ad.
- IFF_MASTER_ALB
bonding master, balance-alb.
- IFF_MASTER_ARPMON
bonding master, ARP mon in use
- IFF_MONITOR
user-requested monitor mode
- IFF_MULTICAST
supports multicast
- IFF_NOARP
no address resolution protocol
- IFF_NOTRAILERS
avoid use of trailers
- IFF_OACTIVE
transmission in progress
- IFF_OVS_DATAPATH
device used as Open vSwitch datapath port
- IFF_POINTOPOINT
point-to-point link
- IFF_PORTSEL
can set media type
- IFF_PPROMISC
user-requested promisc mode
- IFF_PROMISC
receive all packets
- IFF_RENAMING
interface is being renamed
- IFF_ROUTE
routing entry installed
- IFF_RUNNING
resources allocated
- IFF_SIMPLEX
can’t hear own transmissions
- IFF_SLAVE
slave of a load balancer
- IFF_SLAVE_INACTIVE
bonding slave not the curr. active
- IFF_SLAVE_NEEDARP
need ARPs for validation
- IFF_SMART
interface manages own routes
- IFF_STATICARP
static ARP
- IFF_SUPP_NOFCS
sending custom FCS
- IFF_TEAM_PORT
used as team port
- IFF_TX_SKB_SHARING
sharing skbs on transmit
- IFF_UNICAST_FLT
unicast filtering
- IFF_UP
interface is up
- IFF_VOLATILE
volatile flags
- IFF_WAN_HDLC
WAN HDLC device
- IFF_XMIT_DST_RELEASE
dev_hard_start_xmit() is allowed to release skb->dst
- IFNAMSIZ
Maximum interface name size
- IF_NAMESIZE
Maximum interface name size
- INADDR_ALLHOSTS_GROUP
Multicast group for all systems on this subset
- INADDR_ANY
A socket bound to
INADDR_ANY
receives packets from all interfaces and sends from the default IP address- INADDR_BROADCAST
The network broadcast address
- INADDR_LOOPBACK
The loopback address
- INADDR_MAX_LOCAL_GROUP
The last local network multicast group
- INADDR_NONE
A bitmask for matching no valid IP address
- INADDR_UNSPEC_GROUP
The reserved multicast group
- INET6_ADDRSTRLEN
Maximum length of an IPv6 address string
- INET_ADDRSTRLEN
Maximum length of an IPv4 address string
- IPPORT_RESERVED
Default minimum address for bind or connect
- IPPORT_USERRESERVED
Default maximum address for bind or connect
- IPPROTO_AH
IP6 auth header
- IPPROTO_BIP
- IPPROTO_DSTOPTS
IP6 destination option
- IPPROTO_EGP
Exterior Gateway Protocol
- IPPROTO_EON
ISO cnlp
- IPPROTO_ESP
IP6 Encapsulated Security Payload
- IPPROTO_FRAGMENT
IP6 fragmentation header
- IPPROTO_GGP
Gateway to Gateway Protocol
- IPPROTO_HELLO
“hello” routing protocol
- IPPROTO_HOPOPTS
IP6 hop-by-hop options
- IPPROTO_ICMP
Control message protocol
- IPPROTO_ICMPV6
ICMP6
- IPPROTO_IDP
XNS IDP
- IPPROTO_IGMP
Group Management Protocol
- IPPROTO_IP
Dummy protocol for IP
- IPPROTO_IPV6
IP6 header
- IPPROTO_MAX
Maximum IPPROTO constant
- IPPROTO_ND
Sun net disk protocol
- IPPROTO_NONE
IP6 no next header
- IPPROTO_PUP
PARC Universal Packet protocol
- IPPROTO_RAW
Raw IP packet
- IPPROTO_ROUTING
IP6 routing header
- IPPROTO_TCP
TCP
- IPPROTO_TP
ISO transport protocol class 4
- IPPROTO_UDP
UDP
- IPPROTO_XTP
Xpress Transport Protocol
- IPV6_CHECKSUM
Checksum offset for raw sockets
- IPV6_DONTFRAG
Don’t fragment packets
- IPV6_DSTOPTS
Destination option
- IPV6_HOPLIMIT
Hop limit
- IPV6_HOPOPTS
Hop-by-hop option
- IPV6_JOIN_GROUP
Join a group membership
- IPV6_LEAVE_GROUP
Leave a group membership
- IPV6_MULTICAST_HOPS
IP6 multicast hops
- IPV6_MULTICAST_IF
IP6 multicast interface
- IPV6_MULTICAST_LOOP
IP6 multicast loopback
- IPV6_NEXTHOP
Next hop address
- IPV6_PATHMTU
Retrieve current path MTU
- IPV6_PKTINFO
Receive packet information with datagram
- IPV6_RECVDSTOPTS
Receive all IP6 options for response
- IPV6_RECVHOPLIMIT
Receive hop limit with datagram
- IPV6_RECVHOPOPTS
Receive hop-by-hop options
- IPV6_RECVPATHMTU
Receive current path MTU with datagram
- IPV6_RECVPKTINFO
Receive destination IP address and incoming interface
- IPV6_RECVRTHDR
Receive routing header
- IPV6_RECVTCLASS
Receive traffic class
- IPV6_RTHDR
Allows removal of sticky routing headers
- IPV6_RTHDRDSTOPTS
Allows removal of sticky destination options header
- IPV6_RTHDR_TYPE_0
Routing header type 0
- IPV6_TCLASS
Specify the traffic class
- IPV6_UNICAST_HOPS
IP6 unicast hops
- IPV6_USE_MIN_MTU
Use the minimum MTU size
- IPV6_V6ONLY
Only bind IPv6 with a wildcard bind
- IPX_TYPE
- IP_ADD_MEMBERSHIP
Add a multicast group membership
- IP_ADD_SOURCE_MEMBERSHIP
Add a multicast group membership
- IP_BLOCK_SOURCE
Block IPv4 multicast packets with a give source address
- IP_DEFAULT_MULTICAST_LOOP
Default multicast loopback
- IP_DEFAULT_MULTICAST_TTL
Default multicast TTL
- IP_DONTFRAG
Don’t fragment packets
- IP_DROP_MEMBERSHIP
Drop a multicast group membership
- IP_DROP_SOURCE_MEMBERSHIP
Drop a multicast group membership
- IP_FREEBIND
Allow binding to nonexistent IP addresses
- IP_HDRINCL
Header is included with data
- IP_IPSEC_POLICY
IPsec security policy
- IP_MAX_MEMBERSHIPS
Maximum number multicast groups a socket can join
- IP_MINTTL
Minimum TTL allowed for received packets
- IP_MSFILTER
Multicast source filtering
- IP_MTU
The Maximum Transmission Unit of the socket
- IP_MTU_DISCOVER
Path MTU discovery
- IP_MULTICAST_IF
IP multicast interface
- IP_MULTICAST_LOOP
IP multicast loopback
- IP_MULTICAST_TTL
IP multicast TTL
- IP_ONESBCAST
Force outgoing broadcast datagrams to have the undirected broadcast address
- IP_OPTIONS
IP options to be included in packets
- IP_PASSSEC
Retrieve security context with datagram
- IP_PKTINFO
Receive packet information with datagrams
- IP_PKTOPTIONS
Receive packet options with datagrams
- IP_PMTUDISC_DO
Always send DF frames
- IP_PMTUDISC_DONT
Never send DF frames
- IP_PMTUDISC_WANT
Use per-route hints
- IP_PORTRANGE
Set the port range for sockets with unspecified port numbers
- IP_RECVDSTADDR
Receive IP destination address with datagram
- IP_RECVERR
Enable extended reliable error message passing
- IP_RECVIF
Receive interface information with datagrams
- IP_RECVOPTS
Receive all IP options with datagram
- IP_RECVRETOPTS
Receive all IP options for response
- IP_RECVSLLA
Receive link-layer address with datagrams
- IP_RECVTOS
Receive TOS with incoming packets
- IP_RECVTTL
Receive IP TTL with datagrams
- IP_RETOPTS
IP options to be included in datagrams
- IP_ROUTER_ALERT
Notify transit routers to more closely examine the contents of an IP packet
- IP_SENDSRCADDR
Source address for outgoing UDP datagrams
- IP_TOS
IP type-of-service
- IP_TRANSPARENT
Transparent proxy
- IP_TTL
IP time-to-live
- IP_UNBLOCK_SOURCE
Unblock IPv4 multicast packets with a give source address
- IP_XFRM_POLICY
- LOCAL_CONNWAIT
Connect blocks until accepted
- LOCAL_CREDS
Pass credentials to receiver
- LOCAL_PEERCRED
Retrieve peer credentials
- MCAST_BLOCK_SOURCE
Block multicast packets from this source
- MCAST_EXCLUDE
Exclusive multicast source filter
- MCAST_INCLUDE
Inclusive multicast source filter
- MCAST_JOIN_GROUP
Join a multicast group
- MCAST_JOIN_SOURCE_GROUP
Join a multicast source group
- MCAST_LEAVE_GROUP
Leave a multicast group
- MCAST_LEAVE_SOURCE_GROUP
Leave a multicast source group
- MCAST_MSFILTER
Multicast source filtering
- MCAST_UNBLOCK_SOURCE
Unblock multicast packets from this source
- MSG_COMPAT
End of record
- MSG_CONFIRM
Confirm path validity
- MSG_CTRUNC
Control data lost before delivery
- MSG_DONTROUTE
Send without using the routing tables
- MSG_DONTWAIT
This message should be non-blocking
- MSG_EOF
Data completes connection
- MSG_EOR
Data completes record
- MSG_ERRQUEUE
Fetch message from error queue
- MSG_FASTOPEN
Reduce step of the handshake process
- MSG_FIN
- MSG_FLUSH
Start of a hold sequence. Dumps to so_temp
- MSG_HAVEMORE
Data ready to be read
- MSG_HOLD
Hold fragment in so_temp
- MSG_MORE
Sender will send more
- MSG_NOSIGNAL
Do not generate SIGPIPE
- MSG_OOB
Process out-of-band data
- MSG_PEEK
Peek at incoming message
- MSG_PROXY
Wait for full request
- MSG_RCVMORE
Data remains in the current packet
- MSG_RST
- MSG_SEND
Send the packet in so_temp
- MSG_SYN
- MSG_TRUNC
Data discarded before delivery
- MSG_WAITALL
Wait for full request or error
- NI_DGRAM
The service specified is a datagram service (looks up UDP ports)
- NI_MAXHOST
Maximum length of a hostname
- NI_MAXSERV
Maximum length of a service name
- NI_NAMEREQD
A name is required
- NI_NOFQDN
An FQDN is not required for local hosts, return only the local part
- NI_NUMERICHOST
Return a numeric address
- NI_NUMERICSERV
Return the service name as a digit string
- PF_ALG
Interface to kernel crypto API
- PF_APPLETALK
AppleTalk protocol
- PF_ATM
Asynchronous Transfer Mode
- PF_AX25
AX.25 protocol
- PF_BLUETOOTH
Bluetooth low-level socket protocol
- PF_CAN
Controller Area Network automotive bus protocol
- PF_CCITT
CCITT (now ITU-T) protocols
- PF_CHAOS
MIT CHAOS protocols
- PF_CNT
Computer Network Technology
- PF_COIP
Connection-oriented IP
- PF_DATAKIT
Datakit protocol
- PF_DEC
DECnet protocol
- PF_DECnet
DECnet protocol
- PF_DLI
DEC Direct Data Link Interface protocol
- PF_ECMA
European Computer Manufacturers protocols
- PF_HYLINK
NSC Hyperchannel protocol
- PF_IB
InfiniBand native addressing
- PF_IMPLINK
ARPANET IMP protocol
- PF_INET
IPv4 protocol
- PF_INET6
IPv6 protocol
- PF_IPX
IPX protocol
- PF_ISDN
Integrated Services Digital Network
- PF_ISO
ISO Open Systems Interconnection protocols
- PF_KCM
KCM (kernel connection multiplexor) interface
- PF_KEY
Key management protocol, originally developed for usage with IPsec
- PF_LAT
Local Area Transport protocol
- PF_LINK
Link layer interface
- PF_LLC
Logical link control (IEEE 802.2 LLC) protocol
- PF_LOCAL
Host-internal protocols
- PF_MAX
Maximum address family for this platform
- PF_MPLS
Multiprotocol Label Switching
- PF_NATM
Native ATM access
- PF_NDRV
Network driver raw access
- PF_NETBIOS
NetBIOS
- PF_NETGRAPH
Netgraph sockets
- PF_NETLINK
Kernel user interface device
- PF_NS
XEROX NS protocols
- PF_OSI
ISO Open Systems Interconnection protocols
- PF_PACKET
Direct link-layer access
- PF_PIP
Help Identify PIP packets
- PF_PPP
Point-to-Point Protocol
- PF_PPPOX
Generic PPP transport layer, for setting up L2 tunnels (L2TP and PPPoE)
- PF_PUP
PARC Universal Packet protocol
- PF_RDS
Reliable Datagram Sockets (RDS) protocol
- PF_ROUTE
Internal routing protocol
- PF_RTIP
Help Identify RTIP packets
- PF_SIP
Simple Internet Protocol
- PF_SNA
IBM SNA protocol
- PF_SYSTEM
Kernel event messages
- PF_TIPC
TIPC, “cluster domain sockets” protocol
- PF_UNIX
UNIX sockets
- PF_UNSPEC
Unspecified protocol, any supported address family
- PF_VSOCK
VSOCK (originally “VMWare VSockets”) protocol for hypervisor-guest communication
- PF_XDP
XDP (express data path) interface
- PF_XTP
eXpress Transfer Protocol
- SCM_BINTIME
Timestamp (bintime)
- SCM_CREDENTIALS
The sender’s credentials
- SCM_CREDS
Process credentials
- SCM_RIGHTS
Access rights
- SCM_TIMESTAMP
Timestamp (timeval)
- SCM_TIMESTAMPING
Timestamp (timespec list) (Linux 2.6.30)
- SCM_TIMESTAMPNS
Timespec (timespec)
- SCM_UCRED
User credentials
- SCM_WIFI_STATUS
Wifi status (Linux 3.3)
- SHUT_RD
Shut down the reading side of the socket
- SHUT_RDWR
Shut down the both sides of the socket
- SHUT_WR
Shut down the writing side of the socket
- SOCK_CLOEXEC
Set the close-on-exec (FD_CLOEXEC) flag on the new file descriptor.
- SOCK_DGRAM
A datagram socket provides connectionless, unreliable messaging
- SOCK_NONBLOCK
Set the O_NONBLOCK file status flag on the open file description (see open(2)) referred to by the new file descriptor.
- SOCK_PACKET
Device-level packet access
- SOCK_RAW
A raw socket provides low-level access for direct access or implementing network protocols
- SOCK_RDM
A reliable datagram socket provides reliable delivery of messages
- SOCK_SEQPACKET
A sequential packet socket provides sequenced, reliable two-way connection for datagrams
- SOCK_STREAM
A stream socket provides a sequenced, reliable two-way connection for a byte stream
- SOL_ATALK
AppleTalk socket options
- SOL_AX25
AX.25 socket options
- SOL_IP
IP socket options
- SOL_IPX
IPX socket options
- SOL_SOCKET
Socket-level options
- SOL_TCP
TCP socket options
- SOL_UDP
UDP socket options
- SOMAXCONN
Maximum connection requests that may be queued for a socket
- SOPRI_BACKGROUND
Background socket priority
- SOPRI_INTERACTIVE
Interactive socket priority
- SOPRI_NORMAL
Normal socket priority
- SO_ACCEPTCONN
Socket has had listen() called on it
- SO_ACCEPTFILTER
There is an accept filter
- SO_ALLZONES
Bypass zone boundaries
- SO_ATTACH_FILTER
Attach an accept filter
- SO_BINDTODEVICE
Only send packets from the given interface
- SO_BINTIME
Receive timestamp with datagrams (bintime)
- SO_BPF_EXTENSIONS
Query supported BPF extensions (Linux 3.14)
- SO_BROADCAST
Permit sending of broadcast messages
- SO_BUSY_POLL
Set the threshold in microseconds for low latency polling (Linux 3.11)
- SO_DEBUG
Debug info recording
- SO_DETACH_FILTER
Detach an accept filter
- SO_DOMAIN
Domain given for socket() (Linux 2.6.32)
- SO_DONTROUTE
Use interface addresses
- SO_DONTTRUNC
Retain unread data
- SO_ERROR
Get and clear the error status
- SO_GET_FILTER
Obtain filter set by
SO_ATTACH_FILTER
(Linux 3.8)- SO_INCOMING_CPU
Receive the cpu attached to the socket (Linux 3.19)
- SO_INCOMING_NAPI_ID
Receive the napi ID attached to a RX queue (Linux 4.12)
- SO_KEEPALIVE
Keep connections alive
- SO_LINGER
Linger on close if data is present
- SO_LOCK_FILTER
Lock the filter attached to a socket (Linux 3.9)
- SO_MAC_EXEMPT
Mandatory Access Control exemption for unlabeled peers
- SO_MARK
Set the mark for mark-based routing (Linux 2.6.25)
- SO_MAX_PACING_RATE
Cap the rate computed by transport layer. [bytes per second] (Linux 3.13)
- SO_NKE
Install socket-level Network Kernel Extension
- SO_NOFCS
Set netns of a socket (Linux 3.4)
- SO_NOSIGPIPE
Don’t SIGPIPE on EPIPE
- SO_NO_CHECK
Disable checksums
- SO_NREAD
Get first packet byte count
- SO_OOBINLINE
Leave received out-of-band data in-line
- SO_PASSCRED
Receive
SCM_CREDENTIALS
messages- SO_PASSSEC
Toggle security context passing (Linux 2.6.18)
- SO_PEEK_OFF
Set the peek offset (Linux 3.4)
- SO_PEERCRED
The credentials of the foreign process connected to this socket
- SO_PEERNAME
Name of the connecting user
- SO_PEERSEC
Obtain the security credentials (Linux 2.6.2)
- SO_PRIORITY
The protocol-defined priority for all packets on this socket
- SO_PROTOCOL
Protocol given for socket() (Linux 2.6.32)
- SO_RCVBUF
Receive buffer size
- SO_RCVBUFFORCE
Receive buffer size without rmem_max limit (Linux 2.6.14)
- SO_RCVLOWAT
Receive low-water mark
- SO_RCVTIMEO
Receive timeout
- SO_RECVUCRED
Receive user credentials with datagram
- SO_REUSEADDR
Allow local address reuse
- SO_REUSEPORT
Allow local address and port reuse
- SO_RTABLE
Set the routing table for this socket (OpenBSD)
- SO_RXQ_OVFL
Toggle cmsg for number of packets dropped (Linux 2.6.33)
- SO_SECURITY_AUTHENTICATION
- SO_SECURITY_ENCRYPTION_NETWORK
- SO_SECURITY_ENCRYPTION_TRANSPORT
- SO_SELECT_ERR_QUEUE
Make select() detect socket error queue with errorfds (Linux 3.10)
- SO_SETFIB
Set the associated routing table for the socket (FreeBSD)
- SO_SNDBUF
Send buffer size
- SO_SNDBUFFORCE
Send buffer size without wmem_max limit (Linux 2.6.14)
- SO_SNDLOWAT
Send low-water mark
- SO_SNDTIMEO
Send timeout
- SO_TIMESTAMP
Receive timestamp with datagrams (timeval)
- SO_TIMESTAMPING
Time stamping of incoming and outgoing packets (Linux 2.6.30)
- SO_TIMESTAMPNS
Receive nanosecond timestamp with datagrams (timespec)
- SO_TYPE
Get the socket type
- SO_USELOOPBACK
Bypass hardware when possible
- SO_USER_COOKIE
Setting an identifier for ipfw purpose mainly
- SO_WANTMORE
Give a hint when more data is ready
- SO_WANTOOBFLAG
OOB data is wanted in MSG_FLAG on receive
- SO_WIFI_STATUS
Toggle cmsg for wifi status (Linux 3.3)
- TCP_CONGESTION
TCP congestion control algorithm (Linux 2.6.13, glibc 2.6)
- TCP_CONNECTION_INFO
Retrieve information about this socket (macOS)
- TCP_COOKIE_TRANSACTIONS
TCP Cookie Transactions (Linux 2.6.33, glibc 2.18)
- TCP_CORK
Don’t send partial frames (Linux 2.2, glibc 2.2)
- TCP_DEFER_ACCEPT
Don’t notify a listening socket until data is ready (Linux 2.4, glibc 2.2)
- TCP_FASTOPEN
Reduce step of the handshake process (Linux 3.7, glibc 2.18)
- TCP_INFO
Retrieve information about this socket (Linux 2.4, glibc 2.2)
- TCP_KEEPALIVE
Idle time before keepalive probes are sent (macOS)
- TCP_KEEPCNT
Maximum number of keepalive probes allowed before dropping a connection (Linux 2.4, glibc 2.2)
- TCP_KEEPIDLE
Idle time before keepalive probes are sent (Linux 2.4, glibc 2.2)
- TCP_KEEPINTVL
Time between keepalive probes (Linux 2.4, glibc 2.2)
- TCP_LINGER2
Lifetime of orphaned FIN_WAIT2 sockets (Linux 2.4, glibc 2.2)
- TCP_MAXSEG
Set maximum segment size
- TCP_MD5SIG
Use MD5 digests (RFC2385, Linux 2.6.20, glibc 2.7)
- TCP_NODELAY
Don’t delay sending to coalesce packets
- TCP_NOOPT
Don’t use TCP options
- TCP_NOPUSH
Don’t push the last block of write
- TCP_QUEUE_SEQ
Sequence of a queue for repair mode (Linux 3.5, glibc 2.18)
- TCP_QUICKACK
Enable quickack mode (Linux 2.4.4, glibc 2.3)
- TCP_REPAIR
Repair mode (Linux 3.5, glibc 2.18)
- TCP_REPAIR_OPTIONS
Options for repair mode (Linux 3.5, glibc 2.18)
- TCP_REPAIR_QUEUE
Queue for repair mode (Linux 3.5, glibc 2.18)
- TCP_SYNCNT
Number of SYN retransmits before a connection is dropped (Linux 2.4, glibc 2.2)
- TCP_THIN_DUPACK
Duplicated acknowledgments handling for thin-streams (Linux 2.6.34, glibc 2.18)
- TCP_THIN_LINEAR_TIMEOUTS
Linear timeouts for thin-streams (Linux 2.6.34, glibc 2.18)
- TCP_TIMESTAMP
TCP timestamp (Linux 3.9, glibc 2.18)
- TCP_USER_TIMEOUT
Max timeout before a TCP connection is aborted (Linux 2.6.37, glibc 2.18)
- TCP_WINDOW_CLAMP
Clamp the size of the advertised window (Linux 2.4, glibc 2.2)
- UDP_CORK
Don’t send partial frames (Linux 2.5.44, glibc 2.11)
Public Class Methods
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.
# File socket/lib/socket.rb, line 805 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| sock, addr = r.accept_nonblock(exception: false) next if sock == :wait_readable yield sock, addr } } end
Obtains address information for nodename:servname.
Note that Addrinfo.getaddrinfo
provides the same functionality in an object oriented style.
family should be an address family such as: :INET, :INET6, etc.
socktype should be a socket type such as: :STREAM, :DGRAM, :RAW, etc.
protocol should be a protocol defined in the family, and defaults to 0 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 reverse_lookup is omitted, 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 the same as numeric address. +nil+: obey to the current +do_not_reverse_lookup+ flag.
If Addrinfo
object is preferred, use Addrinfo.getaddrinfo
.
static VALUE sock_s_getaddrinfo(int argc, VALUE *argv, VALUE _) { VALUE host, port, family, socktype, protocol, flags, ret, revlookup; struct addrinfo hints; struct rb_addrinfo *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); rb_freeaddrinfo(res); return ret; }
Use Addrinfo#getnameinfo
instead. This method is deprecated for the following reasons:
-
Uncommon address representation: 4/16-bytes binary string to represent IPv4/IPv6 address.
-
gethostbyaddr() may take a long time and it may block other threads. (GVL cannot be released since gethostbyname() is not thread safe.)
-
This method uses gethostbyname() function already removed from POSIX.
This method obtains the host information for address.
p Socket.gethostbyaddr([221,186,184,68].pack("CCCC")) #=> ["carbon.ruby-lang.org", [], 2, "\xDD\xBA\xB8D"] p Socket.gethostbyaddr([127,0,0,1].pack("CCCC")) ["localhost", [], 2, "\x7F\x00\x00\x01"] p Socket.gethostbyaddr(([0]*15+[1]).pack("C"*16)) #=> ["localhost", ["ip6-localhost", "ip6-loopback"], 10, "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01"]
static VALUE sock_s_gethostbyaddr(int argc, VALUE *argv, VALUE _) { VALUE addr, family; struct hostent *h; char **pch; VALUE ary, names; int t = AF_INET; rb_warn("Socket.gethostbyaddr is deprecated; use Addrinfo#getnameinfo instead."); rb_scan_args(argc, argv, "11", &addr, &family); StringValue(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_SOCKLEN(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; }
Use Addrinfo.getaddrinfo
instead. This method is deprecated for the following reasons:
-
The 3rd element of the result is the address family of the first address. The address families of the rest of the addresses are not returned.
-
Uncommon address representation: 4/16-bytes binary string to represent IPv4/IPv6 address.
-
gethostbyname() may take a long time and it may block other threads. (GVL cannot be released since gethostbyname() is not thread safe.)
-
This method uses gethostbyname() function already removed from POSIX.
This method obtains the host information for hostname.
p Socket.gethostbyname("hal") #=> ["localhost", ["hal"], 2, "\x7F\x00\x00\x01"]
static VALUE sock_s_gethostbyname(VALUE obj, VALUE host) { rb_warn("Socket.gethostbyname is deprecated; use Addrinfo.getaddrinfo instead."); struct rb_addrinfo *res = rsock_addrinfo(host, Qnil, AF_UNSPEC, SOCK_STREAM, AI_CANONNAME); return rsock_make_hostent(host, res, sock_sockaddr); }
Returns the hostname.
p Socket.gethostname #=> "hal"
Note that it is not guaranteed to be able to convert to IP address using gethostbyname, getaddrinfo, etc. If you need local IP address, use Socket.ip_address_list
.
static VALUE sock_gethostname(VALUE obj) { #if defined(NI_MAXHOST) # define RUBY_MAX_HOST_NAME_LEN NI_MAXHOST #elif defined(HOST_NAME_MAX) # define RUBY_MAX_HOST_NAME_LEN HOST_NAME_MAX #else # define RUBY_MAX_HOST_NAME_LEN 1024 #endif long len = RUBY_MAX_HOST_NAME_LEN; VALUE name; name = rb_str_new(0, len); while (gethostname(RSTRING_PTR(name), len) < 0) { int e = errno; switch (e) { case ENAMETOOLONG: #ifdef __linux__ case EINVAL: /* glibc before version 2.1 uses EINVAL instead of ENAMETOOLONG */ #endif break; default: rb_syserr_fail(e, "gethostname(3)"); } rb_str_modify_expand(name, len); len += len; } rb_str_resize(name, strlen(RSTRING_PTR(name))); return name; }
Returns an array of interface addresses. An element of the array is an instance of Socket::Ifaddr
.
This method can be used to find multicast-enabled interfaces:
pp Socket.getifaddrs.reject {|ifaddr| !ifaddr.addr.ip? || (ifaddr.flags & Socket::IFF_MULTICAST == 0) }.map {|ifaddr| [ifaddr.name, ifaddr.ifindex, ifaddr.addr] } #=> [["eth0", 2, #<Addrinfo: 221.186.184.67>], # ["eth0", 2, #<Addrinfo: fe80::216:3eff:fe95:88bb%eth0>]]
Example result on GNU/Linux:
pp Socket.getifaddrs #=> [#<Socket::Ifaddr lo UP,LOOPBACK,RUNNING,0x10000 PACKET[protocol=0 lo hatype=772 HOST hwaddr=00:00:00:00:00:00]>, # #<Socket::Ifaddr eth0 UP,BROADCAST,RUNNING,MULTICAST,0x10000 PACKET[protocol=0 eth0 hatype=1 HOST hwaddr=00:16:3e:95:88:bb] broadcast=PACKET[protocol=0 eth0 hatype=1 HOST hwaddr=ff:ff:ff:ff:ff:ff]>, # #<Socket::Ifaddr sit0 NOARP PACKET[protocol=0 sit0 hatype=776 HOST hwaddr=00:00:00:00]>, # #<Socket::Ifaddr lo UP,LOOPBACK,RUNNING,0x10000 127.0.0.1 netmask=255.0.0.0>, # #<Socket::Ifaddr eth0 UP,BROADCAST,RUNNING,MULTICAST,0x10000 221.186.184.67 netmask=255.255.255.240 broadcast=221.186.184.79>, # #<Socket::Ifaddr lo UP,LOOPBACK,RUNNING,0x10000 ::1 netmask=ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff>, # #<Socket::Ifaddr eth0 UP,BROADCAST,RUNNING,MULTICAST,0x10000 fe80::216:3eff:fe95:88bb%eth0 netmask=ffff:ffff:ffff:ffff::>]
Example result on FreeBSD:
pp Socket.getifaddrs #=> [#<Socket::Ifaddr usbus0 UP,0x10000 LINK[usbus0]>, # #<Socket::Ifaddr re0 UP,BROADCAST,RUNNING,MULTICAST,0x800 LINK[re0 3a:d0:40:9a:fe:e8]>, # #<Socket::Ifaddr re0 UP,BROADCAST,RUNNING,MULTICAST,0x800 10.250.10.18 netmask=255.255.255.? (7 bytes for 16 bytes sockaddr_in) broadcast=10.250.10.255>, # #<Socket::Ifaddr re0 UP,BROADCAST,RUNNING,MULTICAST,0x800 fe80:2::38d0:40ff:fe9a:fee8 netmask=ffff:ffff:ffff:ffff::>, # #<Socket::Ifaddr re0 UP,BROADCAST,RUNNING,MULTICAST,0x800 2001:2e8:408:10::12 netmask=UNSPEC>, # #<Socket::Ifaddr plip0 POINTOPOINT,MULTICAST,0x800 LINK[plip0]>, # #<Socket::Ifaddr lo0 UP,LOOPBACK,RUNNING,MULTICAST LINK[lo0]>, # #<Socket::Ifaddr lo0 UP,LOOPBACK,RUNNING,MULTICAST ::1 netmask=ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff>, # #<Socket::Ifaddr lo0 UP,LOOPBACK,RUNNING,MULTICAST fe80:4::1 netmask=ffff:ffff:ffff:ffff::>, # #<Socket::Ifaddr lo0 UP,LOOPBACK,RUNNING,MULTICAST 127.0.0.1 netmask=255.?.?.? (5 bytes for 16 bytes sockaddr_in)>]
static VALUE socket_s_getifaddrs(VALUE self) { return rsock_getifaddrs(); }
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: The last form is compatible with IPSocket#addr
and IPSocket#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
.
static VALUE sock_s_getnameinfo(int argc, VALUE *argv, VALUE _) { VALUE sa, af = Qnil, host = Qnil, port = Qnil, flags, tmp; char hbuf[1024], pbuf[1024]; int fl; struct rb_addrinfo *res = NULL; struct addrinfo hints, *r; int error, saved_errno; union_sockaddr ss; struct sockaddr *sap; socklen_t salen; 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 (!VALIDATE_SOCKLEN(&ss.addr, RSTRING_LEN(sa))) { rb_raise(rb_eTypeError, "sockaddr size differs - should not happen"); } sap = &ss.addr; salen = RSTRING_SOCKLEN(sa); 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_AREF(sa, 0); port = RARRAY_AREF(sa, 1); host = RARRAY_AREF(sa, 2); } else if (RARRAY_LEN(sa) >= 4) { af = RARRAY_AREF(sa, 0); port = RARRAY_AREF(sa, 1); host = RARRAY_AREF(sa, 3); if (NIL_P(host)) { host = RARRAY_AREF(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)); } hints.ai_socktype = (fl & NI_DGRAM) ? SOCK_DGRAM : SOCK_STREAM; /* af */ hints.ai_family = NIL_P(af) ? PF_UNSPEC : rsock_family_arg(af); res = rsock_getaddrinfo(host, port, &hints, 0); sap = res->ai->ai_addr; salen = res->ai->ai_addrlen; } else { rb_raise(rb_eTypeError, "expecting String or Array"); } call_nameinfo: error = rb_getnameinfo(sap, salen, hbuf, sizeof(hbuf), pbuf, sizeof(pbuf), fl); if (error) goto error_exit_name; if (res) { for (r = res->ai->ai_next; r; r = r->ai_next) { char hbuf2[1024], pbuf2[1024]; sap = r->ai_addr; salen = r->ai_addrlen; error = rb_getnameinfo(sap, salen, hbuf2, sizeof(hbuf2), pbuf2, sizeof(pbuf2), fl); if (error) goto error_exit_name; if (strcmp(hbuf, hbuf2) != 0|| strcmp(pbuf, pbuf2) != 0) { rb_freeaddrinfo(res); rb_raise(rb_eSocket, "sockaddr resolved to multiple nodename"); } } rb_freeaddrinfo(res); } return rb_assoc_new(rb_str_new2(hbuf), rb_str_new2(pbuf)); error_exit_name: saved_errno = errno; if (res) rb_freeaddrinfo(res); errno = saved_errno; rsock_raise_resolution_error("getnameinfo", error); UNREACHABLE_RETURN(Qnil); }
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
static VALUE sock_s_getservbyname(int argc, VALUE *argv, VALUE _) { 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); }
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"
static VALUE sock_s_getservbyport(int argc, VALUE *argv, VALUE _) { 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_str_new2(sp->s_name); }
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>, ...]
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)) { struct sockaddr *addr = p->ifa_addr; #if defined(AF_INET6) && defined(__sun) /* * OpenIndiana SunOS 5.11 getifaddrs() returns IPv6 link local * address with sin6_scope_id == 0. * So fill it from the interface name (ifa_name). */ struct sockaddr_in6 addr6; if (addr->sa_family == AF_INET6) { socklen_t len = (socklen_t)sizeof(struct sockaddr_in6); memcpy(&addr6, addr, len); addr = (struct sockaddr *)&addr6; if (IN6_IS_ADDR_LINKLOCAL(&addr6.sin6_addr) && addr6.sin6_scope_id == 0) { unsigned int ifindex = if_nametoindex(p->ifa_name); if (ifindex != 0) { addr6.sin6_scope_id = ifindex; } } } #endif rb_ary_push(list, sockaddr_obj(addr, sockaddr_len(addr))); } } freeifaddrs(ifp); return list; #elif defined(SIOCGLIFCONF) && defined(SIOCGLIFNUM) /* Solaris if_tcp(7P) */ int fd = -1; int ret; struct lifnum ln; struct lifconf lc; const 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(2)"); 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, req->lifr_addrlen)); } } finish: save_errno = errno; xfree(lc.lifc_req); if (fd != -1) close(fd); errno = save_errno; if (reason) rb_syserr_fail(save_errno, reason); return list; #elif defined(SIOCGIFCONF) int fd = -1; int ret; #define EXTRA_SPACE ((int)(sizeof(struct ifconf) + sizeof(union_sockaddr))) 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(2)"); 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, sockaddr_len(addr))); } #ifdef HAVE_STRUCT_SOCKADDR_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_syserr_fail(save_errno, 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, uni->Address.iSockaddrLength)); } 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, any->Address.iSockaddrLength)); } } FreeLibrary(h); return list; #endif }
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 is optional and should be a protocol defined in the domain. If protocol 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
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); 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); }
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"
static VALUE sock_s_pack_sockaddr_in(VALUE self, VALUE port, VALUE host) { struct rb_addrinfo *res = rsock_addrinfo(host, port, AF_UNSPEC, 0, 0); VALUE addr = rb_str_new((char*)res->ai->ai_addr, res->ai->ai_addrlen); rb_freeaddrinfo(res); return addr; }
Packs path as an AF_UNIX
sockaddr string.
Socket.sockaddr_un("/tmp/sock") #=> "\x01\x00/tmp/sock\x00\x00..."
static VALUE sock_s_pack_sockaddr_un(VALUE self, VALUE path) { struct sockaddr_un sockaddr; VALUE addr; StringValue(path); INIT_SOCKADDR_UN(&sockaddr, sizeof(struct sockaddr_un)); if (sizeof(sockaddr.sun_path) < (size_t)RSTRING_LEN(path)) { rb_raise(rb_eArgError, "too long unix socket path (%"PRIuSIZE" bytes given but %"PRIuSIZE" bytes max)", (size_t)RSTRING_LEN(path), sizeof(sockaddr.sun_path)); } memcpy(sockaddr.sun_path, RSTRING_PTR(path), RSTRING_LEN(path)); addr = rb_str_new((char*)&sockaddr, rsock_unix_sockaddr_len(path)); return addr; }
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, defaults to 0 for the domain.
s1, s2 = Socket.pair(:UNIX, :STREAM, 0) s1.send "a", 0 s1.send "b", 0 s1.close p s2.recv(10) #=> "ab" p s2.recv(10) #=> "" p s2.recv(10) #=> "" 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"
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 = rsock_socketpair(d, t, p, sp); if (ret < 0) { rb_sys_fail("socketpair(2)"); } 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; }
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"
static VALUE sock_s_pack_sockaddr_in(VALUE self, VALUE port, VALUE host) { struct rb_addrinfo *res = rsock_addrinfo(host, port, AF_UNSPEC, 0, 0); VALUE addr = rb_str_new((char*)res->ai->ai_addr, res->ai->ai_addrlen); rb_freeaddrinfo(res); return addr; }
Packs path as an AF_UNIX
sockaddr string.
Socket.sockaddr_un("/tmp/sock") #=> "\x01\x00/tmp/sock\x00\x00..."
static VALUE sock_s_pack_sockaddr_un(VALUE self, VALUE path) { struct sockaddr_un sockaddr; VALUE addr; StringValue(path); INIT_SOCKADDR_UN(&sockaddr, sizeof(struct sockaddr_un)); if (sizeof(sockaddr.sun_path) < (size_t)RSTRING_LEN(path)) { rb_raise(rb_eArgError, "too long unix socket path (%"PRIuSIZE" bytes given but %"PRIuSIZE" bytes max)", (size_t)RSTRING_LEN(path), sizeof(sockaddr.sun_path)); } memcpy(sockaddr.sun_path, RSTRING_PTR(path), RSTRING_LEN(path)); addr = rb_str_new((char*)&sockaddr, rsock_unix_sockaddr_len(path)); return addr; }
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, defaults to 0 for the domain.
s1, s2 = Socket.pair(:UNIX, :STREAM, 0) s1.send "a", 0 s1.send "b", 0 s1.close p s2.recv(10) #=> "ab" p s2.recv(10) #=> "" p s2.recv(10) #=> "" 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"
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 = rsock_socketpair(d, t, p, sp); if (ret < 0) { rb_sys_fail("socketpair(2)"); } 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; }
creates a new socket object connected to host:port using TCP/IP.
If local_host:local_port is given, the socket is bound to it.
The optional last argument opts is options represented by a hash. opts may have following options:
- :connect_timeout
-
specify the timeout in seconds.
If a block is given, the block is called with the socket. The value of the block is returned. The socket is closed when this method returns.
If no block is given, the socket is returned.
Socket.tcp("www.ruby-lang.org", 80) {|sock| sock.print "GET / HTTP/1.0\r\nHost: www.ruby-lang.org\r\n\r\n" sock.close_write puts sock.read }
# File socket/lib/socket.rb, line 628 def self.tcp(host, port, local_host = nil, local_port = nil, connect_timeout: nil, resolv_timeout: 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, timeout: resolv_timeout) {|ai| if local_addr_list local_addr = local_addr_list.find {|local_ai| local_ai.afamily == ai.afamily } next unless local_addr else local_addr = nil end begin sock = local_addr ? ai.connect_from(local_addr, timeout: connect_timeout) : ai.connect(timeout: connect_timeout) rescue SystemCallError last_error = $! next end ret = sock break } unless 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 end else ret end end
creates a TCP/IP server on port and calls the block for each connection accepted. The block is called with a socket and a client_address as an Addrinfo
object.
If host is specified, it is used with port to determine the server addresses.
The socket is not closed when the block returns. So application should close it explicitly.
This method calls the block sequentially. It means that the next connection is not accepted until the block returns. So concurrent mechanism, thread for example, should be used to service multiple clients at a time.
Note that Addrinfo.getaddrinfo
is used to determine the server socket addresses. When Addrinfo.getaddrinfo
returns two or more addresses, IPv4 and IPv6 address for example, all of them are used. Socket.tcp_server_loop
succeeds if one socket can be used at least.
# Sequential echo server. # It services only one client at a time. Socket.tcp_server_loop(16807) {|sock, client_addrinfo| begin IO.copy_stream(sock, sock) ensure sock.close end } # Threaded echo server # It services multiple clients at a time. # Note that it may accept connections too much. Socket.tcp_server_loop(16807) {|sock, client_addrinfo| Thread.new { begin IO.copy_stream(sock, sock) ensure sock.close end } }
# File socket/lib/socket.rb, line 861 def self.tcp_server_loop(host=nil, port, &b) # :yield: socket, client_addrinfo tcp_server_sockets(host, port) {|sockets| accept_loop(sockets, &b) } end
creates TCP/IP server sockets for host and port. host is optional.
If no block given, it returns an array of listening sockets.
If a block is given, the block is called with the sockets. The value of the block is returned. The socket is closed when this method returns.
If port is 0, actual port number is chosen dynamically. However all sockets in the result has same port number.
# tcp_server_sockets returns two sockets. sockets = Socket.tcp_server_sockets(1296) p sockets #=> [#<Socket:fd 3>, #<Socket:fd 4>] # The sockets contains IPv6 and IPv4 sockets. sockets.each {|s| p s.local_address } #=> #<Addrinfo: [::]:1296 TCP> # #<Addrinfo: 0.0.0.0:1296 TCP> # IPv6 and IPv4 socket has same port number, 53114, even if it is chosen dynamically. sockets = Socket.tcp_server_sockets(0) sockets.each {|s| p s.local_address } #=> #<Addrinfo: [::]:53114 TCP> # #<Addrinfo: 0.0.0.0:53114 TCP> # The block is called with the sockets. Socket.tcp_server_sockets(0) {|sockets| p sockets #=> [#<Socket:fd 3>, #<Socket:fd 4>] }
# File socket/lib/socket.rb, line 761 def self.tcp_server_sockets(host=nil, port) if port == 0 sockets = tcp_server_sockets_port0(host) else last_error = nil sockets = [] begin Addrinfo.foreach(host, port, nil, :STREAM, nil, Socket::AI_PASSIVE) {|ai| begin s = ai.listen rescue SystemCallError last_error = $! next end sockets << s } if sockets.empty? raise last_error end rescue Exception sockets.each(&:close) raise end end if block_given? begin yield sockets ensure sockets.each(&:close) end else sockets end end
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 }
# File socket/lib/socket.rb, line 1031 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
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.
# File socket/lib/socket.rb, line 1004 def self.udp_server_loop_on(sockets, &b) # :yield: msg, msg_src loop { readable, _, _ = IO.select(sockets) udp_server_recv(readable, &b) } end
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| ... } } }
# File socket/lib/socket.rb, line 977 def self.udp_server_recv(sockets) sockets.each {|r| msg, sender_addrinfo, _, *controls = r.recvmsg_nonblock(exception: false) next if msg == :wait_readable 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
Creates UDP/IP sockets for a UDP server.
If no block given, it returns an array of sockets.
If a block is given, the block is called with the sockets. The value of the block is returned. The sockets are closed when this method returns.
If port is zero, some port is chosen. But the chosen port is used for the all sockets.
# UDP/IP echo server Socket.udp_server_sockets(0) {|sockets| p sockets.first.local_address.ip_port #=> 32963 Socket.udp_server_loop_on(sockets) {|msg, msg_src| msg_src.reply msg } }
# File socket/lib/socket.rb, line 889 def self.udp_server_sockets(host=nil, port) last_error = nil sockets = [] ipv6_recvpktinfo = nil if defined? Socket::AncillaryData if defined? Socket::IPV6_RECVPKTINFO # RFC 3542 ipv6_recvpktinfo = Socket::IPV6_RECVPKTINFO elsif defined? Socket::IPV6_PKTINFO # RFC 2292 ipv6_recvpktinfo = Socket::IPV6_PKTINFO end end local_addrs = Socket.ip_address_list ip_list = [] Addrinfo.foreach(host, port, nil, :DGRAM, nil, Socket::AI_PASSIVE) {|ai| if ai.ipv4? && ai.ip_address == "0.0.0.0" local_addrs.each {|a| next unless a.ipv4? ip_list << Addrinfo.new(a.to_sockaddr, :INET, :DGRAM, 0); } elsif ai.ipv6? && ai.ip_address == "::" && !ipv6_recvpktinfo local_addrs.each {|a| next unless a.ipv6? ip_list << Addrinfo.new(a.to_sockaddr, :INET6, :DGRAM, 0); } else ip_list << ai end } ip_list.uniq!(&:to_sockaddr) if port == 0 sockets = ip_sockets_port0(ip_list, false) else ip_list.each {|ip| ai = Addrinfo.udp(ip.ip_address, port) begin s = ai.bind rescue SystemCallError last_error = $! next end sockets << s } if sockets.empty? raise last_error end end sockets.each {|s| ai = s.local_address if ipv6_recvpktinfo && ai.ipv6? && ai.ip_address == "::" s.setsockopt(:IPV6, ipv6_recvpktinfo, 1) end } if block_given? begin yield sockets ensure sockets.each(&:close) if sockets end else sockets end end
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 }
# File socket/lib/socket.rb, line 1081 def self.unix(path) # :yield: socket addr = Addrinfo.unix(path) sock = addr.connect if block_given? begin yield sock ensure sock.close end else sock end end
creates a UNIX socket server on path. It calls the block for each socket accepted.
If host is specified, it is used with port to determine the server ports.
The socket is not closed when the block returns. So application should close it.
This method deletes the socket file pointed by path at first if the file is a socket file and it is owned by the user of the application. This is safe only if the directory of path is not changed by a malicious user. So don’t use /tmp/malicious-users-directory/socket. Note that /tmp/socket and /tmp/your-private-directory/socket is safe assuming that /tmp has sticky bit.
# Sequential echo server. # It services only one client at a time. Socket.unix_server_loop("/tmp/sock") {|sock, client_addrinfo| begin IO.copy_stream(sock, sock) ensure sock.close end }
# File socket/lib/socket.rb, line 1168 def self.unix_server_loop(path, &b) # :yield: socket, client_addrinfo unix_server_socket(path) {|serv| accept_loop(serv, &b) } end
creates a UNIX server socket on path
If no block given, it returns a listening socket.
If a block is given, it is called with the socket and the block value is returned. When the block exits, the socket is closed and the socket file is removed.
socket = Socket.unix_server_socket("/tmp/s") p socket #=> #<Socket:fd 3> p socket.local_address #=> #<Addrinfo: /tmp/s SOCK_STREAM> Socket.unix_server_socket("/tmp/sock") {|s| p s #=> #<Socket:fd 3> p s.local_address #=> # #<Addrinfo: /tmp/sock SOCK_STREAM> }
# File socket/lib/socket.rb, line 1111 def self.unix_server_socket(path) unless unix_socket_abstract_name?(path) begin st = File.lstat(path) rescue Errno::ENOENT end if st&.socket? && st.owned? File.unlink path end end s = Addrinfo.unix(path).listen if block_given? begin yield s ensure s.close unless unix_socket_abstract_name?(path) File.unlink path end end else s end end
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"]
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, RSTRING_SOCKLEN(addr)); return rb_assoc_new(INT2NUM(ntohs(sockaddr->sin_port)), host); }
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"
static VALUE sock_s_unpack_sockaddr_un(VALUE self, VALUE addr) { struct sockaddr_un * sockaddr; 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)); } path = rsock_unixpath_str(sockaddr, RSTRING_SOCKLEN(addr)); return path; }
Private Class Methods
# File socket/lib/socket.rb, line 1139 def unix_socket_abstract_name?(path) /linux/ =~ RUBY_PLATFORM && /\A(\0|\z)/ =~ path end
Public Instance Methods
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>]
static VALUE sock_accept(VALUE server) { union_sockaddr buffer; socklen_t length = (socklen_t)sizeof(buffer); VALUE peer = rsock_s_accept(rb_cSocket, server, &buffer.addr, &length); return rb_assoc_new(peer, rsock_io_socket_addrinfo(peer, &buffer.addr, length)); }
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([socket]) retry end puts "The client said, '#{client_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.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::EAGAIN, 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.
By specifying a keyword argument exception to false
, you can indicate that accept_nonblock
should not raise an IO::WaitReadable exception, but return the symbol :wait_readable
instead.
See¶ ↑
# File socket/lib/socket.rb, line 598 def accept_nonblock(exception: true) __accept_nonblock(exception) end
Binds to the given local address.
Parameter¶ ↑
-
local_sockaddr
- thestruct
sockaddr contained in a string or anAddrinfo
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 thesocket
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
static VALUE sock_bind(VALUE sock, VALUE addr) { VALUE rai; rb_io_t *fptr; SockAddrStringValueWithAddrinfo(addr, rai); GetOpenFile(sock, fptr); if (bind(fptr->fd, (struct sockaddr*)RSTRING_PTR(addr), RSTRING_SOCKLEN(addr)) < 0) rsock_sys_fail_raddrinfo_or_sockaddr("bind(2)", addr, rai); return INT2FIX(0); }
Requests a connection to be made on the given remote_sockaddr
. Returns 0 if successful, otherwise an exception is raised.
Parameter¶ ↑
-
remote_sockaddr
- thestruct
sockaddr contained in a string orAddrinfo
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/1.0\r\n\r\n" ) 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 timed 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 timed 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
static VALUE sock_connect(VALUE sock, VALUE addr) { VALUE rai; rb_io_t *fptr; int fd, n; SockAddrStringValueWithAddrinfo(addr, rai); addr = rb_str_new4(addr); GetOpenFile(sock, fptr); fd = fptr->fd; n = rsock_connect(fd, (struct sockaddr*)RSTRING_PTR(addr), RSTRING_SOCKLEN(addr), 0, NULL); if (n < 0) { rsock_sys_fail_raddrinfo_or_sockaddr("connect(2)", addr, rai); } return INT2FIX(n); }
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/1.0\r\n\r\n") 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.
By specifying a keyword argument exception to false
, you can indicate that connect_nonblock
should not raise an IO::WaitWritable exception, but return the symbol :wait_writable
instead.
See¶ ↑
# Socket#connect
# File socket/lib/socket.rb, line 1218 def connect_nonblock(addr, exception: true) __connect_nonblock(addr, exception) end
enable the socket option IPV6_V6ONLY
if IPV6_V6ONLY
is available.
# File socket/lib/socket.rb, line 468 def ipv6only! if defined? Socket::IPV6_V6ONLY self.setsockopt(:IPV6, :V6ONLY, 1) end end
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
VALUE rsock_sock_listen(VALUE sock, VALUE log) { rb_io_t *fptr; int backlog; backlog = NUM2INT(log); GetOpenFile(sock, fptr); if (listen(fptr->fd, backlog) < 0) rb_sys_fail("listen(2)"); return INT2FIX(0); }
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 theMSG_
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; orMSG_OOB
is set and no out-of-band data is available and either thesocket
file descriptor is marked as O_NONBLOCK or thesocket
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, orMSG_OOB
was specified for a socket withSO_OOBINLINE
enabled, or (for byte stream-style sockets only) the internal len parameter onsocket
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, butsocket
is not stream-style such as typeSOCK_STREAM
. OOB data is not supported in the communication domain associated withsocket
, orsocket
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.
static VALUE sock_recvfrom(int argc, VALUE *argv, VALUE sock) { return rsock_s_recvfrom(sock, argc, argv, RECV_SOCKET); }
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#recv_nonblock
returns nil. In most cases it means the connection was closed, but for UDP connections it may mean an empty packet was received, as the underlying API makes it impossible to distinguish these two cases.
Parameters¶ ↑
-
maxlen
- the maximum number of bytes to receive from the socket -
flags
- zero or more of theMSG_
options -
outbuf
- destination String buffer -
opts
- keyword hash, supporting ‘exception: false`
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([client]) retry end data = pair[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.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::EAGAIN, it is extended by IO::WaitReadable. So IO::WaitReadable can be used to rescue the exceptions for retrying recvfrom_nonblock.
By specifying a keyword argument exception to false
, you can indicate that recvfrom_nonblock
should not raise an IO::WaitReadable exception, but return the symbol :wait_readable
instead.
See¶ ↑
# File socket/lib/socket.rb, line 541 def recvfrom_nonblock(len, flag = 0, str = nil, exception: true) __recvfrom_nonblock(len, flag, str, exception) end
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, '#{client_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.readline.chomp}'" socket.close
Refer to Socket#accept
for the exceptions that may be thrown if the call to sysaccept fails.
See¶ ↑
static VALUE sock_sysaccept(VALUE server) { union_sockaddr buffer; socklen_t length = (socklen_t)sizeof(buffer); VALUE peer = rsock_s_accept(0, server, &buffer.addr, &length); return rb_assoc_new(peer, rsock_io_socket_addrinfo(peer, &buffer.addr, length)); }