UDPSocket
represents a UDP/IP socket.
static VALUE
udp_init(int argc, VALUE *argv, VALUE sock)
{
VALUE arg;
int family = AF_INET;
int fd;
if (rb_scan_args(argc, argv, "01", &arg) == 1) {
family = rsock_family_arg(arg);
}
fd = rsock_socket(family, SOCK_DGRAM, 0);
if (fd < 0) {
rb_sys_fail("socket(2) - udp");
}
return rsock_init_sock(sock, fd);
}
Creates a new UDPSocket
object.
address_family should be an integer, a string or a symbol: Socket::AF_INET, “AF_INET”, :INET, etc.
require 'socket' UDPSocket.new #=> #<UDPSocket:fd 3> UDPSocket.new(Socket::AF_INET6) #=> #<UDPSocket:fd 4>
static VALUE
udp_bind(VALUE sock, VALUE host, VALUE port)
{
struct udp_arg arg;
VALUE ret;
GetOpenFile(sock, arg.fptr);
arg.res = rsock_addrinfo(host, port, rsock_fd_family(arg.fptr->fd), SOCK_DGRAM, 0);
ret = rb_ensure(udp_bind_internal, (VALUE)&arg,
rsock_freeaddrinfo, (VALUE)arg.res);
if (!ret) rsock_sys_fail_host_port("bind(2)", host, port);
return INT2FIX(0);
}
Binds udpsocket to host:port.
u1 = UDPSocket.new u1.bind("127.0.0.1", 4913) u1.send "message-to-self", 0, "127.0.0.1", 4913 p u1.recvfrom(10) #=> ["message-to", ["AF_INET", 4913, "localhost", "127.0.0.1"]]
static VALUE
udp_connect(VALUE sock, VALUE host, VALUE port)
{
struct udp_arg arg;
VALUE ret;
GetOpenFile(sock, arg.fptr);
arg.res = rsock_addrinfo(host, port, rsock_fd_family(arg.fptr->fd), SOCK_DGRAM, 0);
ret = rb_ensure(udp_connect_internal, (VALUE)&arg,
rsock_freeaddrinfo, (VALUE)arg.res);
if (!ret) rsock_sys_fail_host_port("connect(2)", host, port);
return INT2FIX(0);
}
Connects udpsocket to host:port.
This makes possible to send without destination address.
u1 = UDPSocket.new u1.bind("127.0.0.1", 4913) u2 = UDPSocket.new u2.connect("127.0.0.1", 4913) u2.send "uuuu", 0 p u1.recvfrom(10) #=> ["uuuu", ["AF_INET", 33230, "localhost", "127.0.0.1"]]
# File tmp/rubies/ruby-3.0.5/ext/socket/lib/socket.rb, line 1271
def recvfrom_nonblock(len, flag = 0, outbuf = nil, exception: true)
__recvfrom_nonblock(len, flag, outbuf, exception)
end
Receives up to maxlen bytes from udpsocket
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_inet_addr, is an array to represent the sender address.
When recvfrom(2) returns 0, Socket#recvfrom_nonblock
returns an empty string as data. It means an empty packet.
Parameters
-
maxlen
- the number of bytes to receive from the socket -
flags
- zero or more of theMSG_
options -
outbuf
- destinationString
buffer -
options
- keyword hash, supporting ‘exception: false`
Example
require 'socket' s1 = UDPSocket.new s1.bind("127.0.0.1", 0) s2 = UDPSocket.new s2.bind("127.0.0.1", 0) s2.connect(*s1.addr.values_at(3,1)) s1.connect(*s2.addr.values_at(3,1)) s1.send "aaa", 0 begin # emulate blocking recvfrom p s2.recvfrom_nonblock(10) #=> ["aaa", ["AF_INET", 33302, "localhost.localdomain", "127.0.0.1"]] rescue IO::WaitReadable IO.select([s2]) retry end
Refer to Socket#recvfrom
for the exceptions that may be thrown if the call to recvfrom_nonblock fails.
UDPSocket#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
udp_send(int argc, VALUE *argv, VALUE sock)
{
VALUE flags, host, port;
struct udp_send_arg arg;
VALUE ret;
if (argc == 2 || argc == 3) {
return rsock_bsock_send(argc, argv, sock);
}
rb_scan_args(argc, argv, "4", &arg.sarg.mesg, &flags, &host, &port);
StringValue(arg.sarg.mesg);
GetOpenFile(sock, arg.fptr);
arg.sarg.fd = arg.fptr->fd;
arg.sarg.flags = NUM2INT(flags);
arg.res = rsock_addrinfo(host, port, rsock_fd_family(arg.fptr->fd), SOCK_DGRAM, 0);
ret = rb_ensure(udp_send_internal, (VALUE)&arg,
rsock_freeaddrinfo, (VALUE)arg.res);
if (!ret) rsock_sys_fail_host_port("sendto(2)", host, port);
return ret;
}
Sends mesg via udpsocket.
flags should be a bitwise OR of Socket::MSG_* constants.
u1 = UDPSocket.new u1.bind("127.0.0.1", 4913) u2 = UDPSocket.new u2.send "hi", 0, "127.0.0.1", 4913 mesg, addr = u1.recvfrom(10) u1.send mesg, 0, addr[3], addr[1] p u2.recv(100) #=> "hi"