Socket::Constants provides socket-related constants. All possible socket constants are listed in the documentation but they may not all be present on your platform.
If the underlying platform doesn’t define a constant the corresponding Ruby constant is not defined.
A stream socket provides a sequenced, reliable two-way connection for a byte stream
A datagram socket provides connectionless, unreliable messaging
A raw socket provides low-level access for direct access or implementing network protocols
A reliable datagram socket provides reliable delivery of messages
A sequential packet socket provides sequenced, reliable two-way connection for datagrams
Device-level packet access
Set the O_NONBLOCK file status flag on the open file description (see open(2)) referred to by the new file descriptor.
Set the close-on-exec (FD_CLOEXEC) flag on the new file descriptor.
Unspecified protocol, any supported address family
Unspecified protocol, any supported address family
IPv4 protocol
IPv4 protocol
IPv6 protocol
IPv6 protocol
UNIX sockets
UNIX sockets
AX.25 protocol
AX.25 protocol
IPX protocol
IPX protocol
AppleTalk protocol
AppleTalk protocol
Host-internal protocols
Host-internal protocols
ARPANET IMP protocol
ARPANET IMP protocol
PARC Universal Packet protocol
PARC Universal Packet protocol
MIT CHAOS protocols
MIT CHAOS protocols
XEROX NS protocols
XEROX NS protocols
ISO Open Systems Interconnection protocols
ISO Open Systems Interconnection protocols
ISO Open Systems Interconnection protocols
ISO Open Systems Interconnection protocols
European Computer Manufacturers protocols
European Computer Manufacturers protocols
Datakit protocol
Datakit protocol
CCITT (now ITU-T) protocols
CCITT (now ITU-T) protocols
IBM SNA protocol
IBM SNA protocol
DECnet protocol
DECnet protocol
DECnet protocol
DECnet protocol
DEC Direct Data Link Interface protocol
DEC Direct Data Link Interface protocol
Local Area Transport protocol
Local Area Transport protocol
NSC Hyperchannel protocol
NSC Hyperchannel protocol
Internal routing protocol
Internal routing protocol
Link layer interface
Link layer interface
Connection-oriented IP
Connection-oriented IP
Computer Network Technology
Computer Network Technology
Simple Internet Protocol
Simple Internet Protocol
Network driver raw access
Network driver raw access
Integrated Services Digital Network
Integrated Services Digital Network
Native ATM access
Native ATM access
Kernel event messages
Kernel event messages
NetBIOS
NetBIOS
Point-to-Point Protocol
Point-to-Point Protocol
Asynchronous Transfer Mode
Asynchronous Transfer Mode
Netgraph sockets
Netgraph sockets
Maximum address family for this platform
Maximum address family for this platform
Direct link-layer access
Direct link-layer access
CCITT (ITU-T) E.164 recommendation
eXpress Transfer Protocol
Help Identify RTIP packets
Help Identify PIP packets
Key management protocol, originally developed for usage with IPsec
Key management protocol, originally developed for usage with IPsec
Kernel user interface device
Kernel user interface device
Reliable Datagram Sockets (RDS) protocol
Reliable Datagram Sockets (RDS) protocol
Generic PPP transport layer, for setting up L2 tunnels (L2TP and PPPoE)
Generic PPP transport layer, for setting up L2 tunnels (L2TP and PPPoE)
Logical link control (IEEE 802.2 LLC) protocol
Logical link control (IEEE 802.2 LLC) protocol
InfiniBand native addressing
InfiniBand native addressing
Multiprotocol Label Switching
Multiprotocol Label Switching
Controller Area Network automotive bus protocol
Controller Area Network automotive bus protocol
TIPC, “cluster domain sockets” protocol
TIPC, “cluster domain sockets” protocol
Bluetooth low-level socket protocol
Bluetooth low-level socket protocol
Interface to kernel crypto API
Interface to kernel crypto API
VSOCK (originally “VMWare VSockets”) protocol for hypervisor-guest communication
VSOCK (originally “VMWare VSockets”) protocol for hypervisor-guest communication
KCM (kernel connection multiplexor) interface
KCM (kernel connection multiplexor) interface
XDP (express data path) interface
XDP (express data path) interface
Process out-of-band data
Peek at incoming message
Send without using the routing tables
Data completes record
Data discarded before delivery
Control data lost before delivery
Wait for full request or error
This message should be non-blocking
Data completes connection
Start of a hold sequence. Dumps to so_temp
Hold fragment in so_temp
Send the packet in so_temp
Data ready to be read
Data remains in the current packet
End of record
Wait for full request
Confirm path validity
Fetch message from error queue
Do not generate SIGPIPE
Sender will send more
Reduce step of the handshake process
Socket-level options
IP socket options
IPX socket options
AX.25 socket options
AppleTalk socket options
TCP socket options
UDP socket options
Dummy protocol for IP
Control message protocol
Group Management Protocol
Gateway to Gateway Protocol
TCP
Exterior Gateway Protocol
PARC Universal Packet protocol
UDP
XNS IDP
“hello” routing protocol
Sun net disk protocol
ISO transport protocol class 4
Xpress Transport Protocol
ISO cnlp
IP6 auth header
IP6 destination option
IP6 Encapsulated Security Payload
IP6 fragmentation header
IP6 hop-by-hop options
ICMP6
IP6 header
IP6 no next header
IP6 routing header
Raw IP packet
Maximum IPPROTO constant
Default minimum address for bind or connect
Default maximum address for bind or connect
A socket bound to INADDR_ANY receives packets from all interfaces and sends from the default IP address
The network broadcast address
The loopback address
The reserved multicast group
Multicast group for all systems on this subset
The last local network multicast group
A bitmask for matching no valid IP address
IP options to be included in packets
Header is included with data
IP type-of-service
IP time-to-live
Receive all IP options with datagram
Receive all IP options for response
Receive IP destination address with datagram
IP options to be included in datagrams
Minimum TTL allowed for received packets
Don’t fragment packets
Source address for outgoing UDP datagrams
Force outgoing broadcast datagrams to have the undirected broadcast address
Receive IP TTL with datagrams
Receive interface information with datagrams
Receive link-layer address with datagrams
Set the port range for sockets with unspecified port numbers
IP multicast interface
IP multicast TTL
IP multicast loopback
Add a multicast group membership
Drop a multicast group membership
Default multicast TTL
Default multicast loopback
Maximum number multicast groups a socket can join
Notify transit routers to more closely examine the contents of an IP packet
Receive packet information with datagrams
Receive packet options with datagrams
Path MTU discovery
Enable extended reliable error message passing
Receive TOS with incoming packets
The Maximum Transmission Unit of the socket
Allow binding to nonexistent IP addresses
IPsec security policy
Retrieve security context with datagram
Transparent proxy
Never send DF frames
Use per-route hints
Always send DF frames
Unblock IPv4 multicast packets with a give source address
Block IPv4 multicast packets with a give source address
Add a multicast group membership
Drop a multicast group membership
Multicast source filtering
Join a multicast group
Block multicast packets from this source
Unblock multicast packets from this source
Leave a multicast group
Join a multicast source group
Leave a multicast source group
Multicast source filtering
Exclusive multicast source filter
Inclusive multicast source filter
Debug info recording
Allow local address reuse
Allow local address and port reuse
Get the socket type
Get and clear the error status
Use interface addresses
Permit sending of broadcast messages
Send buffer size
Receive buffer size
Send buffer size without wmem_max limit (Linux 2.6.14)
Receive buffer size without rmem_max limit (Linux 2.6.14)
Keep connections alive
Leave received out-of-band data in-line
Disable checksums
The protocol-defined priority for all packets on this socket
Linger on close if data is present
Receive SCM_CREDENTIALS messages
The credentials of the foreign process connected to this socket
Receive low-water mark
Send low-water mark
Receive timeout
Send timeout
Socket has had listen() called on it
Bypass hardware when possible
There is an accept filter
Setting an identifier for ipfw purpose mainly
Retain unread data
Give a hint when more data is ready
OOB data is wanted in MSG_FLAG on receive
Get first packet byte count
Install socket-level Network Kernel Extension
Don’t SIGPIPE on EPIPE
Only send packets from the given interface
Attach an accept filter
Detach an accept filter
Obtain filter set by SO_ATTACH_FILTER (Linux 3.8)
Name of the connecting user
Receive timestamp with datagrams (timeval)
Receive nanosecond timestamp with datagrams (timespec)
Receive timestamp with datagrams (bintime)
Receive user credentials with datagram
Mandatory Access Control exemption for unlabeled peers
Bypass zone boundaries
Obtain the security credentials (Linux 2.6.2)
Toggle security context passing (Linux 2.6.18)
Set the mark for mark-based routing (Linux 2.6.25)
Time stamping of incoming and outgoing packets (Linux 2.6.30)
Protocol given for socket() (Linux 2.6.32)
Domain given for socket() (Linux 2.6.32)
Toggle cmsg for number of packets dropped (Linux 2.6.33)
Toggle cmsg for wifi status (Linux 3.3)
Set the peek offset (Linux 3.4)
Set netns of a socket (Linux 3.4)
Lock the filter attached to a socket (Linux 3.9)
Make select() detect socket error queue with errorfds (Linux 3.10)
Set the threshold in microseconds for low latency polling (Linux 3.11)
Cap the rate computed by transport layer. [bytes per second] (Linux 3.13)
Query supported BPF extensions (Linux 3.14)
Set the associated routing table for the socket (FreeBSD)
Set the routing table for this socket (OpenBSD)
Receive the cpu attached to the socket (Linux 3.19)
Receive the napi ID attached to a RX queue (Linux 4.12)
Interactive socket priority
Normal socket priority
Background socket priority
Don’t delay sending to coalesce packets
Set maximum segment size
Retrieve information about this socket (macOS)
Don’t send partial frames (Linux 2.2, glibc 2.2)
Don’t notify a listening socket until data is ready (Linux 2.4, glibc 2.2)
Retrieve information about this socket (Linux 2.4, glibc 2.2)
Idle time before keepalive probes are sent (macOS)
Maximum number of keepalive probes allowed before dropping a connection (Linux 2.4, glibc 2.2)
Idle time before keepalive probes are sent (Linux 2.4, glibc 2.2)
Time between keepalive probes (Linux 2.4, glibc 2.2)
Lifetime of orphaned FIN_WAIT2 sockets (Linux 2.4, glibc 2.2)
Use MD5 digests (RFC2385, Linux 2.6.20, glibc 2.7)
Don’t use TCP options
Don’t push the last block of write
Enable quickack mode (Linux 2.4.4, glibc 2.3)
Number of SYN retransmits before a connection is dropped (Linux 2.4, glibc 2.2)
Clamp the size of the advertised window (Linux 2.4, glibc 2.2)
Reduce step of the handshake process (Linux 3.7, glibc 2.18)
TCP congestion control algorithm (Linux 2.6.13, glibc 2.6)
TCP Cookie Transactions (Linux 2.6.33, glibc 2.18)
Sequence of a queue for repair mode (Linux 3.5, glibc 2.18)
Repair mode (Linux 3.5, glibc 2.18)
Options for repair mode (Linux 3.5, glibc 2.18)
Queue for repair mode (Linux 3.5, glibc 2.18)
Duplicated acknowledgments handling for thin-streams (Linux 2.6.34, glibc 2.18)
Linear timeouts for thin-streams (Linux 2.6.34, glibc 2.18)
TCP timestamp (Linux 3.9, glibc 2.18)
Max timeout before a TCP connection is aborted (Linux 2.6.37, glibc 2.18)
Don’t send partial frames (Linux 2.5.44, glibc 2.11)
Address family for hostname not supported
Temporary failure in name resolution
Invalid flags
Non-recoverable failure in name resolution
Address family not supported
Memory allocation failure
No address associated with hostname
Hostname nor servname, or not known
Argument buffer overflow
Servname not supported for socket type
Socket type not supported
System error returned in errno
Invalid value for hints
Resolved protocol is unknown
Maximum error code from getaddrinfo
Get address to use with bind()
Fill in the canonical name
Prevent host name resolution
Prevent service name resolution
Valid flag mask for getaddrinfo (not for application use)
Allow all addresses
Accept IPv4 mapped addresses if the kernel supports it
Accept only if any address is assigned
Accept IPv4-mapped IPv6 addresses
Default flags for getaddrinfo
Maximum length of a hostname
Maximum length of a service name
An FQDN is not required for local hosts, return only the local part
Return a numeric address
A name is required
Return the service name as a digit string
The service specified is a datagram service (looks up UDP ports)
Shut down the reading side of the socket
Shut down the writing side of the socket
Shut down the both sides of the socket
Join a group membership
Leave a group membership
IP6 multicast hops
IP6 multicast interface
IP6 multicast loopback
IP6 unicast hops
Only bind IPv6 with a wildcard bind
Checksum offset for raw sockets
Don’t fragment packets
Destination option
Hop limit
Hop-by-hop option
Next hop address
Retrieve current path MTU
Receive packet information with datagram
Receive all IP6 options for response
Receive hop limit with datagram
Receive hop-by-hop options
Receive destination IP address and incoming interface
Receive routing header
Receive traffic class
Allows removal of sticky routing headers
Allows removal of sticky destination options header
Routing header type 0
Receive current path MTU with datagram
Specify the traffic class
Use the minimum MTU size
Maximum length of an IPv4 address string
Maximum length of an IPv6 address string
Maximum interface name size
Maximum interface name size
Maximum connection requests that may be queued for a socket
Access rights
Timestamp (timeval)
Timespec (timespec)
Timestamp (timespec list) (Linux 2.6.30)
Timestamp (bintime)
The sender’s credentials
Process credentials
User credentials
Wifi status (Linux 3.3)
Retrieve peer credentials
Pass credentials to receiver
Connect blocks until accepted
802.1Q VLAN device
receive all multicast packets
use alternate physical connection
auto media select active
bonding master or slave
device used as bridge port
broadcast address valid
unconfigurable using ioctl(2)
turn on debugging
disable netpoll at run-time
disallow bridging this ether dev
driver signals dormant
tx hardware queue is full
resources allocated
interface is winding down
dialup device with changing addresses
ethernet bridging device
echo sent packets
ISATAP interface (RFC4214)
per link layer defined bit 0
per link layer defined bit 1
per link layer defined bit 2
hardware address change when it’s running
loopback net
driver signals L1 up
device used as macvlan port
master of a load balancer
bonding master, 802.3ad.
bonding master, balance-alb.
bonding master, ARP mon in use
user-requested monitor mode
supports multicast
no address resolution protocol
avoid use of trailers
transmission in progress
device used as Open vSwitch datapath port
point-to-point link
can set media type
user-requested promisc mode
receive all packets
interface is being renamed
routing entry installed
resources allocated
can’t hear own transmissions
slave of a load balancer
bonding slave not the curr. active
need ARPs for validation
interface manages own routes
static ARP
sending custom FCS
used as team port
sharing skbs on transmit
unicast filtering
interface is up
WAN HDLC device
dev_hard_start_xmit() is allowed to release skb->dst
volatile flags
flags not changeable