clntudp_create()

The clntudp_create() call creates an RPC client transport handle for the remote program using UDP transport.

Syntax

#include <rpc\rpc.h>
#include <netdb.h>

CLIENT *
clntudp_create(addr, prognum, versnum, wait, sockp)
struct sockaddr_in *addr;
u_long prognum;
u_long versnum;
struct timeval wait;
int *sockp;

Parameters

addr

Pointer to the internet address of the remote program. If addr points to a port number of 0, addr is set to the port on which the remote program is receiving. The remote PORTMAP service is used for this.

Remote program number.

Version number of the remote program.

Interval at which UDP resends the call request, until either a response is received or the call times out. Set the time-out length using the clnt_call() procedure.

Pointer to the socket. If sockp is RPC_ANYSOCK, this routine opens a new socket and sets sockp.

Description

The clntudp_create() call creates a client transport handle for the remote program (prognum) with version (versnum). UDP is used as the transport layer.

Note: Do not use this procedure with procedures that use large arguments or return large results. UDP RPC messages can contain only 2K bytes of encoded data.

Return Values

NULL indicates failure.

Examples

#define RMTPROGNUM   (u_long)0x3fffffffL#define RMTPROGVER   (u_long)0x1L

register CLIENT *clnt;
int sock = RPC_ANYSOCK; /* can be also valid socket descriptor */
struct hostent *hp;
struct timeval pertry_timeout;
struct sockaddr_in server_addr;

/* get the internet address of RPC server */
if ((hp = gethostbyname("RPC_HOST") == NULL)
  {
   fprintf(stderr,"Can't get address for %s\n",argv[2]);
   exit (-1);
  }

pertry_timeout.tv_sec = 3;
pertry_timeout.tv_usec = 0;
bcopy(hp->h_addr, (caddr_t)&server_addr.sin_addr.s_addr, hp->h_length);
server_addr.sin_family = AF_INET;
server_addr.sin_port = 0;

/* create UDP handle */
if ((clnt = clntudp_create(&server_addr, RMTPROGNUM, RMTPROGVER,
                                pertry_timeout, &sock)) == NULL)
   {
    clnt_pcreateerror("clntudp_create");
    exit(-1);
   }

Related Calls

clnt_destroy()
clnt_pcreateerror()
clntraw_create()
clnttcp_create()