class UDPSocket
UDPSocket represents a UDP/IP socket.
Public Class Methods
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);
} 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>
Public Instance Methods
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);
} 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)
{
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);
} 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_recvfrom_nonblock(int argc, VALUE *argv, VALUE sock)
{
return rsock_s_recvfrom_nonblock(sock, argc, argv, RECV_IP);
} 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_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;
rsock_maybe_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);
} 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"
Ruby Core © 1993–2017 Yukihiro Matsumoto
Licensed under the Ruby License.
Ruby Standard Library © contributors
Licensed under their own licenses.