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
- TCP server socket
- UNIX client socket
- UNIX server socket
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.
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
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
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
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
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
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)
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)
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)
Interactive socket priority
Normal socket priority
Background socket priority
Don’t delay sending to coalesce packets
Set
maximum segment size
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)
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
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
# File tmp/rubies/ruby-3.1.3/ext/socket/lib/socket.rb, line 800
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
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.
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;
}
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_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#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_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);
}
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_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 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
socket_s_getifaddrs(VALUE self)
{
return rsock_getifaddrs();
}
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
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_socket_error("getnameinfo", error);
UNREACHABLE_RETURN(Qnil);
}
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_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 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_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);
}
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
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) && !defined(__hpux)
/* Solaris if_tcp(7P) */
/* HP-UX has SIOCGLIFCONF too. But it uses different struct */
int fd = -1;
int ret;
struct lifnum ln;
struct lifconf lc;
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;
if (lc.lifc_buf != NULL)
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
}
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
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);
}
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_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 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_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;
}
Packs path as an AF_UNIX
sockaddr string.
Socket.sockaddr_un("/tmp/sock") #=> "\x01\x00/tmp/sock\x00\x00..."
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 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"
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 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_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;
}
Packs path as an AF_UNIX
sockaddr string.
Socket.sockaddr_un("/tmp/sock") #=> "\x01\x00/tmp/sock\x00\x00..."
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 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"
# File tmp/rubies/ruby-3.1.3/ext/socket/lib/socket.rb, line 623
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 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.
- :resolv_timeout
-
specify the name resolution 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 tmp/rubies/ruby-3.1.3/ext/socket/lib/socket.rb, line 856
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 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 tmp/rubies/ruby-3.1.3/ext/socket/lib/socket.rb, line 756
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 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 tmp/rubies/ruby-3.1.3/ext/socket/lib/socket.rb, line 1026
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
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 tmp/rubies/ruby-3.1.3/ext/socket/lib/socket.rb, line 999
def self.udp_server_loop_on(sockets, &b) # :yield: msg, msg_src
loop {
readable, _, _ = IO.select(sockets)
udp_server_recv(readable, &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 tmp/rubies/ruby-3.1.3/ext/socket/lib/socket.rb, line 972
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
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 tmp/rubies/ruby-3.1.3/ext/socket/lib/socket.rb, line 884
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 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 tmp/rubies/ruby-3.1.3/ext/socket/lib/socket.rb, line 1076
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 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 tmp/rubies/ruby-3.1.3/ext/socket/lib/socket.rb, line 1163
def self.unix_server_loop(path, &b) # :yield: socket, client_addrinfo
unix_server_socket(path) {|serv|
accept_loop(serv, &b)
}
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 tmp/rubies/ruby-3.1.3/ext/socket/lib/socket.rb, line 1106
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
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 tmp/rubies/ruby-3.1.3/ext/socket/lib/socket.rb, line 1134
def unix_socket_abstract_name?(path)
/linux/ =~ RUBY_PLATFORM && /\A(\0|\z)/ =~ path
end
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 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_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;
}
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_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));
}
# File tmp/rubies/ruby-3.1.3/ext/socket/lib/socket.rb, line 592
def accept_nonblock(exception: true)
__accept_nonblock(exception)
end
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
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);
}
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_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
. 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
# File tmp/rubies/ruby-3.1.3/ext/socket/lib/socket.rb, line 1213
def connect_nonblock(addr, exception: true)
__connect_nonblock(addr, exception)
end
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 tmp/rubies/ruby-3.1.3/ext/socket/lib/socket.rb, line 463
def ipv6only!
if defined? Socket::IPV6_V6ONLY
self.setsockopt(:IPV6, :V6ONLY, 1)
end
end
enable the socket option IPV6_V6ONLY
if IPV6_V6ONLY
is available.
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);
}
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
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
. 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.
# File tmp/rubies/ruby-3.1.3/ext/socket/lib/socket.rb, line 535
def recvfrom_nonblock(len, flag = 0, str = nil, exception: true)
__recvfrom_nonblock(len, flag, str, exception)
end
Receives up to maxlen bytes from socket
using recvfrom(2) after O_NONBLOCK is set for the underlying file descriptor. flags is zero or more of the MSG_
options. The first element of the results, mesg, is the data received. The second element, sender_addrinfo, contains protocol-specific address information of the sender.
When recvfrom(2) returns 0, Socket#recvfrom_nonblock
returns an empty string as data. The meaning depends on the socket: EOF on TCP, empty packet on UDP, etc.
Parameters
-
maxlen
- the maximum number of bytes to receive from the socket -
flags
- zero or more of theMSG_
options -
outbuf
- destinationString
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
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));
}
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.