NAME

AutoIP Service – autoip

SYNOPSIS

#include <tcpinit.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h >

int get_autoip(struct tcpinit *etherinit);

// For dual TCP stack:

int get_autoip (unsigned char *mac, char *if_name);

DESCRIPTION

The tcp and udp server or tcpd provides IPv4/IPv6 TCP, UDP and IP protocol support with low level drivers for specific chip support packages. It is a fast and easy to use TCP/UDP solution which requires a simple setup structure at creation time to get it up and running. It offers static IP addresses in IPv4 format unless provisioned with the DHCP client service or AutoIP service for IP address retrieval.

The autoip service generates an IPv4 address following the information from net interface and uses the standard ARP protocol to check if such IP already present on net. Generally there is two ways of using an AutoIP: standalone or together with DHCP client.

More precisely, the autoip service is actually a library that is called and does not run as a separate thread. This library uses the calling thread’s context and sets up the tcpinit structure for use with tcpd. It implements the standard autoip functions in the library and returns control to the calling thread when complete.

SPECIFIC OPTIONS (Compile time)

EXAMPLE

This is the example of the various setup parameters for the tcpd.

#define ETH_ADDR        ETH_BASE
#define ETH_INT_VECT    INT_ETH
#define ETH_INT_LEVEL   0x80

static char	tcpbuf[1024*8];

struct tcpinit etherinit = {
	sizeof(struct tcpinit),             /* message size             */
	0,                                  /* default gateway          */
	ETH_ADDR,                           /* address of ethernet chip */
	ETH_INT_VECT,                       /* interrupt vector         */
	0,                                  /* internet address         */
	{0x00,0x11,0x22,0x33,0x44,0x55},    /* ethernet address         */
	{0,0},                              /* padding                  */
	ETH_INT_LEVEL,                      /* interrupt level          */
	0,                                  /* unit number              */
	tcpbuf,                             /* buffer pointer           */
	sizeof(tcpbuf),                     /* size of buffer           */
	{'l','e',0},                        /* interface name           */
};

This is the example of the various setup parameters for the dual TCP stack.

/*************************************************************************
 *  Subroutine  : tcp_shell
 *  Purpose     : Task shell for starting device specific tcpserver
 ************************************************************************/
THREAD tcp_shell(void *arg)
{
	// clear init structure
	memset(&tcpinit, 0, sizeof(tcpinit));

	// memory
	tcpinit.tcp_pool_start = tcpbuf;
	tcpinit.tcp_pool_size = sizeof(tcpbuf);

	// device
	tcpinit.dev_type = DEV_ETHERNET;
	tcpinit.dev_unit = 0;
	tcpinit.dev_addr = ETH_ADDR;
	tcpinit.dev_vector = ETH_INT_VECT;
	tcpinit.dev_level = ETH_INT_LEVEL;
	tcpinit.eth_mac[0] = 0x00;
	tcpinit.eth_mac[1] = 0x11;
	tcpinit.eth_mac[2] = 0x22;
	tcpinit.eth_mac[3] = 0x33;
	tcpinit.eth_mac[4] = 0x44;
	tcpinit.eth_mac[5] = 0x66;

	// IPv4
	tcpinit.IPv4.IP_address = NULL;
	tcpinit.IPv4.IP_mask = NULL;
	tcpinit.IPv4_default_gateway = NULL;


	tcpd(&tcpinit);
	return 0;	//just to avoid warning
}

This partial example shows the creation and registration of the tcpd using tcp_shell followed with the set IP by AutoIP.

	if(pthread_create(&pid, &attr, &tcp_shell, 0)!=0)
	{
		xprintf("pthread_create = %d\n", errno);
		pthread_exit(0);
	}	

	if(dir_register("/dev/tcpd", pid, TYPE_SERVER)==0)
	{
		xprintf("dir_register = %d\n", errno);
		pthread_exit(0);
	}


	// Set automatic IP
	xprintf("Using AutoIP...\n");
	if(get_autoip(&etherinit) != 0) {
		xprintf("AutoIP could not get params!\n");
		while (1) sleep(1);
	}

	xprintf("Get AutoIP params:\n");
   	xprintf("  Client IP: %d.%d.%d.%d\n",
		((unsigned char *)& etherinit.tcp_IP_address)[0],
		((unsigned char *)& etherinit.tcp_IP_address)[1],
		((unsigned char *)& etherinit.tcp_IP_address)[2],
		((unsigned char *)& etherinit.tcp_IP_address)[3]);
 

This partial example shows the process of setting IP by AutoIP for dual TCP stack.

#if TRY_DHCP
	// Try to get our IP and default GW
	xprintf("Using DHCP...\n");
	dhcp_sts = dhcp_get_params (tcpinit.eth_mac, "eth0", &dhcp_param);
	if (dhcp_sts == -1)
	{
		xprintf("DHCP could not get params! errno = %d\n", errno);
	}
#endif /* TRY_DHCP */

	if (dhcp_sts == -1)
	{
		xprintf("Using AutoIP...\n");
		if(get_autoip(tcpinit.eth_mac, "eth0") != 0) {
			xprintf("AutoIP could not get params!\n");
			while (1) sleep(1);
		}
	}

NOTES

There is a demo available for the Unison and DSPnano AutoIP Service which can be found in installdir/demos.

SEE ALSO

tcpd, dhcp_client