class UDPSocket
UDPSocket represents a UDP/IP socket.
Public Class Methods
Creates a new UDPSocket object.
address_family should be an integer, a string or a symbol: Socket::AF_INET, “AF_INET”, :INET, etc.
UDPSocket.new #=> #<UDPSocket:fd 3> UDPSocket.new(Socket::AF_INET6) #=> #<UDPSocket:fd 4>
static VALUE udp_init(int argc, VALUE *argv, VALUE sock) { VALUE arg; int family = AF_INET; int fd; rb_secure(3); 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); }
Public Instance Methods
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_bind(VALUE sock, VALUE host, VALUE port) { rb_io_t *fptr; struct rb_addrinfo *res0; struct addrinfo *res; rb_secure(3); res0 = rsock_addrinfo(host, port, SOCK_DGRAM, 0); GetOpenFile(sock, fptr); for (res = res0->ai; res; res = res->ai_next) { if (bind(fptr->fd, res->ai_addr, res->ai_addrlen) < 0) { continue; } rb_freeaddrinfo(res0); return INT2FIX(0); } rb_freeaddrinfo(res0); rsock_sys_fail_host_port("bind(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"]]
static VALUE udp_connect(VALUE sock, VALUE host, VALUE port) { rb_io_t *fptr; struct udp_arg arg; VALUE ret; rb_secure(3); arg.res = rsock_addrinfo(host, port, SOCK_DGRAM, 0); GetOpenFile(sock, fptr); arg.fd = fptr->fd; 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); }
Receives up to maxlen bytes from udpsocket
using
recvfrom(2) after O_NONBLOCK is set for the underlying file descriptor. If
maxlen is omitted, its default value is 65536. 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
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.
#recvfrom_nonblock may raise any error corresponding to recvfrom(2) failure, including Errno::EWOULDBLOCK.
If the exception is Errno::EWOULDBLOCK or Errno::AGAIN, it is extended by IO::WaitReadable. So IO::WaitReadable can be used to rescue the exceptions for retrying recvfrom_nonblock.
See¶ ↑
static VALUE udp_recvfrom_nonblock(int argc, VALUE *argv, VALUE sock) { return rsock_s_recvfrom_nonblock(sock, argc, argv, RECV_IP); }
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"
static VALUE udp_send(int argc, VALUE *argv, VALUE sock) { VALUE flags, host, port; rb_io_t *fptr; int n; struct rb_addrinfo *res0; struct addrinfo *res; struct rsock_send_arg arg; if (argc == 2 || argc == 3) { return rsock_bsock_send(argc, argv, sock); } rb_scan_args(argc, argv, "4", &arg.mesg, &flags, &host, &port); StringValue(arg.mesg); res0 = rsock_addrinfo(host, port, SOCK_DGRAM, 0); GetOpenFile(sock, fptr); arg.fd = fptr->fd; arg.flags = NUM2INT(flags); for (res = res0->ai; res; res = res->ai_next) { retry: arg.to = res->ai_addr; arg.tolen = res->ai_addrlen; rb_thread_fd_writable(arg.fd); n = (int)BLOCKING_REGION_FD(rsock_sendto_blocking, &arg); if (n >= 0) { rb_freeaddrinfo(res0); return INT2FIX(n); } if (rb_io_wait_writable(fptr->fd)) { goto retry; } } rb_freeaddrinfo(res0); rsock_sys_fail_host_port("sendto(2)", host, port); return INT2FIX(n); }