HP UX 11i v2 Networking Software manual 164

Sample Programs

Connectionless Mode

/************************************************************************** main

**************************************************************************/

main() {

int	send_fd, recv_fd;	/*	file descriptors */
u_char	sdlsap[20];	/*	sending DLSAP */
u_char	rdlsap[20];	/*	receiving DLSAP */
int	sdlsap_len, rdlsap_len; /*		DLSAP lengths */
int	i, j, recv_len;

/*

PART 1 of program. Demonstrate connectionless data transfer with LLC SAP header.

*/

/*

First, we must open the DLPI device file, /dev/dlpi, and attach to a PPA. attach() will open /dev/dlpi, find the first PPA with the DL_HP_PPA_INFO primitive, and attach to that PPA. attach() returns the file descriptor for the stream. Here we do an attach for each file descriptor.

*/

send_fd = attach(); recv_fd = attach();

/*

Now we have to bind to a IEEESAP. We will ask for connectionless data link service with the DL_CLDLS service mode. Since we are connectionless, we will not have any incoming connections so we

set max_conind to 0. bind() will return our local DLSAP and its length in the last two arguments we pass to it.

*/

bind(send_fd, SEND_SAP, 0, DL_CLDLS, sdlsap, &sdlsap_len); bind(recv_fd, RECV_SAP, 0, DL_CLDLS, rdlsap, &rdlsap_len);

/* print the DLSAPs we got back from the binds */ print_dlsap(”sending DLSAP = ”, sdlsap, sdlsap_len); print_dlsap(”receiving DLSAP = ”, rdlsap, rdlsap_len);

/*

Time to send some data. We'll send 5 data packets in sequence. */

for(i = 0; i < 5; i++) {

/* send (i+1)*10 data bytes with the first byte = i */ data_area[0] = i;

/* Initialize data area */ for (j = 1; j < (i+1)*10; j++)

data_area[j] = ”a”; print_dlsap(”sending data to ”,rdlsap, rdlsap_len);

send_data(send_fd, rdlsap, rdlsap_len, (i + 1) * 10); /* receive the data packet */

recv_len = recv_data(recv_fd);

printf(”received %d bytes, first word = %d\n”, recv_len, data_area[0]);

}

164 Appendix A