SOCKET

Use the SOCKET command to open a socket descriptor in the active socket set.

Restriction: If the socket type is SOCK_RAW or RAW, the user ID associated with the REXX socket application must have z/OS® UNIX System Services superuser authority. The user ID must have the UID value 0 or have read access to the BPX.SUPERUSER security profile. An application can attempt to obtain superuser authority by issuing the z/OS UNIX System Services SYSCALLS command: address syscall 'SETEUID 0'. If this command fails, the user ID does not have the authorization needed to run the program; contact your security administrator.

Format


                        .-,--AF_INET-.  .-,--STREAM-.   
>>-SOCKET--(--"SOCKET"--+------------+--+-----------+----------->
                        '-,--domain--'  '-,--type---'   

   .-,--0--------.      
>--+-------------+--)------------------------------------------><
   '-,--protocol-'

Parameters

domain

The address family of the socket. The supported families are AF_INET (2) and AF_INET6 (19). By default, the domain parameter is set to AF_INET.

type

An optional parameter that specifies the type of socket to be created. By default, this parameter is set to STREAM. The following values are supported:

STREAM or SOCK_STREAM
DATAGRAM or SOCK_DATAGRAM
RAW or SOCK_RAW

protocol

An optional parameter that specifies the protocol that is requested. By default, the value to which this parameter is set depends on the type parameter. The default protocol for stream sockets is TCP. The default protocol for datagram sockets is UDP. There is no default for RAW sockets. To enable the stack to select the applicable protocol, set the protocol parameter to 0.

The following protocols are supported:

Stream sockets

IPPROTO_TCP or TCP

Datagram sockets

IPPROTO_UDP or UDP

RAW sockets

IPPROTO_IP or IP
IPPROTO_IPV6 or IPV6
IPPROTO_ICMP or ICMP
IPPROTO_ICMPV6 or ICMPV6
IPPROTO_RAW or RAW

Returned value

The command returns a string that contains the return code and the new socket descriptor, for example, 0 6. The return code can be 0, a REXX socket API error number, or the REXX TCP/IP error number that is set by the socket command. The return code 0 indicates that the requested socket command was completed successfully.

See Socket call error return codes for additional information about the numeric error codes that are returned by this command.

The following REXX TCP/IP error numbers can be returned:

9 EBADF
22 EINVAL
38 ENOTSOCK
45 EOPNOTSUPP
139 EPERM

The following REXX socket API error numbers can be returned:

2001 EINVALIDRXSOCKETCALL
2005 ESUBTASKNOTACTIVE
2007 EMAXSOCKETSREACHED

LE C/C++ equivalent

int socket(int *domain, int type, int protocol);

Code example

Figure 1. SOCKET command example

/*  REXX EZARXR26 */
/*
 * This sample demonstrates the use of the SOCKET
 * socket command.
 *
 * HINT: See other socket command descriptions for
 *       additional examples.
 */
src=SOCKET("INITIALIZE","MYSET01",20);
src=SOCKET("SOCKET","AF_INET","STREAM")
parse var src l_retcode l_socketid
if l_retcode = 0 then do
   Say "Socket Created Successfully.  Socket descriptor is" l_socketid;
   src=SOCKET("CLOSE",l_socketid);
   parse var src l_retcode .
   if l_retcode = 0 then
      say "Socket "l_socketid" closed successfully";
   else do
      say "Close of socket "l_socketid" failed.";
      say src;
   end;
end;
else do
   Say "Socket not created."
   Say "..."src;
end;
x=SOCKET("TERMINATE","MYSET01");
exit;