Class: BasicSocket

Inherits:
IO
  • Object
show all
Defined in:
socket.c

Direct Known Subclasses

IPSocket, Socket, UNIXSocket

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.do_not_reverse_lookupObject

.do_not_reverse_lookup=Object

.for_fdObject

Instance Method Details

#close_readObject

#close_writeObject

#getpeernameObject

#getsocknameObject

#getsockopt(level, optname) ⇒ Object

Gets a socket option. These are protocol and system specific, see your local sytem documentation for details. The option is returned as a String with the data being the binary value of the socket option.

Parameters

  • level is an integer, usually one of the SOL_ constants such as Socket::SOL_SOCKET, or a protocol level.

  • optname is an integer, usually one of the SO_ constants, such as Socket::SO_REUSEADDR.

Examples

Some socket options are integers with boolean values, in this case #getsockopt could be called like this:

optval = sock.getsockopt(Socket::SOL_SOCKET,Socket::SO_REUSEADDR)
optval = optval.unpack "i"
reuseaddr = optval[0] == 0 ? false : true

Some socket options are integers with numeric values, in this case #getsockopt could be called like this:

optval = sock.getsockopt(Socket::IPPROTO_IP, Socket::IP_TTL)
ipttl = optval.unpack("i")[0]

Option values may be structs. Decoding them can be complex as it involves examining your system headers to determine the correct definition. An example is a struct linger, which may be defined in your system headers as:

struct linger {
  int l_onoff;
  int l_linger;
};

In this case #getsockopt could be called like this:

optval =  sock.getsockopt(Socket::SOL_SOCKET, Socket::SO_LINGER)
onoff, linger = optval.unpack "ii"


# File 'socket.c'

/*
 * Document-method: getsockopt
 * call-seq: getsockopt(level, optname)
 *
 * Gets a socket option. These are protocol and system specific, see your
 * local sytem documentation for details. The option is returned as
 * a String with the data being the binary value of the socket option.
 *
 * === Parameters
 * * +level+ is an integer, usually one of the SOL_ constants such as
 *   Socket::SOL_SOCKET, or a protocol level.
 * * +optname+ is an integer, usually one of the SO_ constants, such
 *   as Socket::SO_REUSEADDR.
 *
 * === Examples
 *
 * Some socket options are integers with boolean values, in this case
 * #getsockopt could be called like this:
 *   optval = sock.getsockopt(Socket::SOL_SOCKET,Socket::SO_REUSEADDR)
 *   optval = optval.unpack "i"
 *   reuseaddr = optval[0] == 0 ? false : true
 *
 * Some socket options are integers with numeric values, in this case
 * #getsockopt could be called like this:
 *   optval = sock.getsockopt(Socket::IPPROTO_IP, Socket::IP_TTL)
 *   ipttl = optval.unpack("i")[0]
 *
 * Option values may be structs. Decoding them can be complex as it involves
 * examining your system headers to determine the correct definition. An
 * example is a +struct linger+, which may be defined in your system headers
 * as:
 *   struct linger {
 *     int l_onoff;
 *     int l_linger;
 *   };
 * 
 * In this case #getsockopt could be called like this:
 *   optval =  sock.getsockopt(Socket::SOL_SOCKET, Socket::SO_LINGER)
 *   onoff, linger = optval.unpack "ii"
*/
static VALUE
bsock_getsockopt(sock, lev, optname)
    VALUE sock, lev, optname;
{
#if !defined(__BEOS__)
    int level, option;
    socklen_t len;
    char *buf;
    OpenFile *fptr;

    level = NUM2INT(lev);
    option = NUM2INT(optname);
    len = 256;
    buf = ALLOCA_N(char,len);
    GetOpenFile(sock, fptr);

    GetOpenFile(sock, fptr);
    if (getsockopt(fileno(fptr->f), level, option, buf, &len) < 0)
    rb_sys_fail(fptr->path);

    return rb_str_new(buf, len);
#else
    rb_notimplement();
#endif
}

#recvObject

#recv_nonblock(maxlen) ⇒ Object #recv_nonblock(maxlen, flags) ⇒ Object

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 result, mesg, is the data received.

When recvfrom(2) returns 0, Socket#recv_nonblock returns an empty string as data. The meaning depends on the socket: EOF on TCP, empty packet on UDP, etc.

Parameters

  • maxlen - the number of bytes to receive from the socket

  • flags - zero or more of the MSG_ options

Example

serv = TCPServer.new("127.0.0.1", 0)
af, port, host, addr = serv.addr
c = TCPSocket.new(addr, port)
s = serv.accept
c.send "aaa", 0
IO.select([s])
p s.recv_nonblock(10) #=> "aaa"

Refer to Socket#recvfrom for the exceptions that may be thrown if the call to recv_nonblock fails.

BasicSocket#recv_nonblock may raise any error corresponding to recvfrom(2) failure, including Errno::EAGAIN.

See

  • Socket#recvfrom



# File 'socket.c'

/*
 * call-seq:
 *  basicsocket.recv_nonblock(maxlen) => mesg
 *  basicsocket.recv_nonblock(maxlen, flags) => mesg
 * 
 * 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 result, _mesg_, is the data received.
 *
 * When recvfrom(2) returns 0, Socket#recv_nonblock returns
 * an empty string as data.
 * The meaning depends on the socket: EOF on TCP, empty packet on UDP, etc.
 * 
 * === Parameters
 * * +maxlen+ - the number of bytes to receive from the socket
 * * +flags+ - zero or more of the +MSG_+ options 
 * 
 * === Example
 *  serv = TCPServer.new("127.0.0.1", 0)
 *  af, port, host, addr = serv.addr
 *  c = TCPSocket.new(addr, port)
 *  s = serv.accept
 *  c.send "aaa", 0
 *  IO.select([s])
 *  p s.recv_nonblock(10) #=> "aaa"
 *
 * Refer to Socket#recvfrom for the exceptions that may be thrown if the call
 * to _recv_nonblock_ fails. 
 *
 * BasicSocket#recv_nonblock may raise any error corresponding to recvfrom(2) failure,
 * including Errno::EAGAIN.
 *
 * === See
 * * Socket#recvfrom
 */

static VALUE
bsock_recv_nonblock(argc, argv, sock)
    int argc;
    VALUE *argv;
    VALUE sock;
{
    return s_recvfrom_nonblock(sock, argc, argv, RECV_RECV);
}

#sendObject

#setsockopt(level, optname, optval) ⇒ Object

Sets a socket option. These are protocol and system specific, see your local sytem documentation for details.

Parameters

  • level is an integer, usually one of the SOL_ constants such as Socket::SOL_SOCKET, or a protocol level.

  • optname is an integer, usually one of the SO_ constants, such as Socket::SO_REUSEADDR.

  • optval is the value of the option, it is passed to the underlying setsockopt() as a pointer to a certain number of bytes. How this is done depends on the type:

    • Fixnum: value is assigned to an int, and a pointer to the int is passed, with length of sizeof(int).

    • true or false: 1 or 0 (respectively) is assigned to an int, and the int is passed as for a Fixnum. Note that false must be passed, not nil.

    • String: the string's data and length is passed to the socket.

Examples

Some socket options are integers with boolean values, in this case #setsockopt could be called like this:

sock.setsockopt(Socket::SOL_SOCKET,Socket::SO_REUSEADDR, true)

Some socket options are integers with numeric values, in this case #setsockopt could be called like this:

sock.setsockopt(Socket::IPPROTO_IP, Socket::IP_TTL, 255)

Option values may be structs. Passing them can be complex as it involves examining your system headers to determine the correct definition. An example is an ip_mreq, which may be defined in your system headers as:

struct ip_mreq {
  struct  in_addr imr_multiaddr;
  struct  in_addr imr_interface;
};

In this case #setsockopt could be called like this:

optval =  IPAddr.new("224.0.0.251") + Socket::INADDR_ANY
sock.setsockopt(Socket::IPPROTO_IP, Socket::IP_ADD_MEMBERSHIP, optval)


# File 'socket.c'

/*
 * Document-method: setsockopt
 * call-seq: setsockopt(level, optname, optval)
 *
 * Sets a socket option. These are protocol and system specific, see your
 * local sytem documentation for details.
 *
 * === Parameters
 * * +level+ is an integer, usually one of the SOL_ constants such as
 *   Socket::SOL_SOCKET, or a protocol level.
 * * +optname+ is an integer, usually one of the SO_ constants, such
 *   as Socket::SO_REUSEADDR.
 * * +optval+ is the value of the option, it is passed to the underlying
 *   setsockopt() as a pointer to a certain number of bytes. How this is
 *   done depends on the type:
 *   - Fixnum: value is assigned to an int, and a pointer to the int is
 *     passed, with length of sizeof(int).
 *   - true or false: 1 or 0 (respectively) is assigned to an int, and the
 *     int is passed as for a Fixnum. Note that +false+ must be passed,
 *     not +nil+.
 *   - String: the string's data and length is passed to the socket.
 *
 * === Examples
 *
 * Some socket options are integers with boolean values, in this case
 * #setsockopt could be called like this:
 *   sock.setsockopt(Socket::SOL_SOCKET,Socket::SO_REUSEADDR, true)
 *
 * Some socket options are integers with numeric values, in this case
 * #setsockopt could be called like this:
 *   sock.setsockopt(Socket::IPPROTO_IP, Socket::IP_TTL, 255)
 *
 * Option values may be structs. Passing them can be complex as it involves
 * examining your system headers to determine the correct definition. An
 * example is an +ip_mreq+, which may be defined in your system headers as:
 *   struct ip_mreq {
 *     struct  in_addr imr_multiaddr;
 *     struct  in_addr imr_interface;
 *   };
 * 
 * In this case #setsockopt could be called like this:
 *   optval =  IPAddr.new("224.0.0.251") + Socket::INADDR_ANY
 *   sock.setsockopt(Socket::IPPROTO_IP, Socket::IP_ADD_MEMBERSHIP, optval)
 *
*/
static VALUE
bsock_setsockopt(sock, lev, optname, val)
    VALUE sock, lev, optname, val;
{
    int level, option;
    OpenFile *fptr;
    int i;
    char *v;
    int vlen;

    rb_secure(2);
    level = NUM2INT(lev);
    option = NUM2INT(optname);

    switch (TYPE(val)) {
      case T_FIXNUM:
    i = FIX2INT(val);
    goto numval;
      case T_FALSE:
    i = 0;
    goto numval;
      case T_TRUE:
    i = 1;
      numval:
    v = (char*)&i; vlen = sizeof(i);
    break;
      default:
    StringValue(val);
    v = RSTRING(val)->ptr;
    vlen = RSTRING(val)->len;
    break;
    }

    GetOpenFile(sock, fptr);
    if (setsockopt(fileno(fptr->f), level, option, v, vlen) < 0)
    rb_sys_fail(fptr->path);

    return INT2FIX(0);
}

#shutdownObject