common/cmd_net.c - github/trini/u-boot - Gitiles

 /*
  * (C) Copyright 2000
  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
  *
  * SPDX-License-Identifier:	GPL-2.0+
  */

 /*
  * Boot support
  */
 #include <common.h>
 #include <command.h>
 #include <net.h>

 static int netboot_common(enum proto_t, cmd_tbl_t *, int, char * const []);

 static int do_bootp(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 {
 	return netboot_common(BOOTP, cmdtp, argc, argv);
 }

 U_BOOT_CMD(
 	bootp,	3,	1,	do_bootp,
 	"boot image via network using BOOTP/TFTP protocol",
 	"[loadAddress] [[hostIPaddr:]bootfilename]"
 );

 int do_tftpb(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 {
 	int ret;

 	bootstage_mark_name(BOOTSTAGE_KERNELREAD_START, "tftp_start");
 	ret = netboot_common(TFTPGET, cmdtp, argc, argv);
 	bootstage_mark_name(BOOTSTAGE_KERNELREAD_STOP, "tftp_done");
 	return ret;
 }

 U_BOOT_CMD(
 	tftpboot,	3,	1,	do_tftpb,
 	"boot image via network using TFTP protocol",
 	"[loadAddress] [[hostIPaddr:]bootfilename]"
 );

 #ifdef CONFIG_CMD_TFTPPUT
 int do_tftpput(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 {
 	return netboot_common(TFTPPUT, cmdtp, argc, argv);
 }

 U_BOOT_CMD(
 	tftpput,	4,	1,	do_tftpput,
 	"TFTP put command, for uploading files to a server",
 	"Address Size [[hostIPaddr:]filename]"
 );
 #endif

 #ifdef CONFIG_CMD_TFTPSRV
 static int do_tftpsrv(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[])
 {
 	return netboot_common(TFTPSRV, cmdtp, argc, argv);
 }

 U_BOOT_CMD(
 	tftpsrv,	2,	1,	do_tftpsrv,
 	"act as a TFTP server and boot the first received file",
 	"[loadAddress]\n"
 	"Listen for an incoming TFTP transfer, receive a file and boot it.\n"
 	"The transfer is aborted if a transfer has not been started after\n"
 	"about 50 seconds or if Ctrl-C is pressed."
 );
 #endif


 #ifdef CONFIG_CMD_RARP
 int do_rarpb(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 {
 	return netboot_common(RARP, cmdtp, argc, argv);
 }

 U_BOOT_CMD(
 	rarpboot,	3,	1,	do_rarpb,
 	"boot image via network using RARP/TFTP protocol",
 	"[loadAddress] [[hostIPaddr:]bootfilename]"
 );
 #endif

 #if defined(CONFIG_CMD_DHCP)
 static int do_dhcp(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 {
 	return netboot_common(DHCP, cmdtp, argc, argv);
 }

 U_BOOT_CMD(
 	dhcp,	3,	1,	do_dhcp,
 	"boot image via network using DHCP/TFTP protocol",
 	"[loadAddress] [[hostIPaddr:]bootfilename]"
 );
 #endif

 #if defined(CONFIG_CMD_NFS)
 static int do_nfs(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 {
 	return netboot_common(NFS, cmdtp, argc, argv);
 }

 U_BOOT_CMD(
 	nfs,	3,	1,	do_nfs,
 	"boot image via network using NFS protocol",
 	"[loadAddress] [[hostIPaddr:]bootfilename]"
 );
 #endif

 static void netboot_update_env(void)
 {
 	char tmp[22];

 	if (net_gateway.s_addr) {
 		ip_to_string(net_gateway, tmp);
 		setenv("gatewayip", tmp);
 	}

 	if (net_netmask.s_addr) {
 		ip_to_string(net_netmask, tmp);
 		setenv("netmask", tmp);
 	}

 	if (net_hostname[0])
 		setenv("hostname", net_hostname);

 	if (net_root_path[0])
 		setenv("rootpath", net_root_path);

 	if (net_ip.s_addr) {
 		ip_to_string(net_ip, tmp);
 		setenv("ipaddr", tmp);
 	}
 #if !defined(CONFIG_BOOTP_SERVERIP)
 	/*
 	 * Only attempt to change serverip if net/bootp.c:BootpCopyNetParams()
 	 * could have set it
 	 */
 	if (net_server_ip.s_addr) {
 		ip_to_string(net_server_ip, tmp);
 		setenv("serverip", tmp);
 	}
 #endif
 	if (net_dns_server.s_addr) {
 		ip_to_string(net_dns_server, tmp);
 		setenv("dnsip", tmp);
 	}
 #if defined(CONFIG_BOOTP_DNS2)
 	if (net_dns_server2.s_addr) {
 		ip_to_string(net_dns_server2, tmp);
 		setenv("dnsip2", tmp);
 	}
 #endif
 	if (net_nis_domain[0])
 		setenv("domain", net_nis_domain);

 #if defined(CONFIG_CMD_SNTP) && defined(CONFIG_BOOTP_TIMEOFFSET)
 	if (net_ntp_time_offset) {
 		sprintf(tmp, "%d", net_ntp_time_offset);
 		setenv("timeoffset", tmp);
 	}
 #endif
 #if defined(CONFIG_CMD_SNTP) && defined(CONFIG_BOOTP_NTPSERVER)
 	if (net_ntp_server.s_addr) {
 		ip_to_string(net_ntp_server, tmp);
 		setenv("ntpserverip", tmp);
 	}
 #endif
 }

 static int netboot_common(enum proto_t proto, cmd_tbl_t *cmdtp, int argc,
 		char * const argv[])
 {
 	char *s;
 	char *end;
 	int   rcode = 0;
 	int   size;
 	ulong addr;

 	/* pre-set load_addr */
 	s = getenv("loadaddr");
 	if (s != NULL)
 		load_addr = simple_strtoul(s, NULL, 16);

 	switch (argc) {
 	case 1:
 		break;

 	case 2:	/*
 		 * Only one arg - accept two forms:
 		 * Just load address, or just boot file name. The latter
 		 * form must be written in a format which can not be
 		 * mis-interpreted as a valid number.
 		 */
 		addr = simple_strtoul(argv[1], &end, 16);
 		if (end == (argv[1] + strlen(argv[1])))
 			load_addr = addr;
 		else
 			copy_filename(net_boot_file_name, argv[1],
 				      sizeof(net_boot_file_name));
 		break;

 	case 3:
 		load_addr = simple_strtoul(argv[1], NULL, 16);
 		copy_filename(net_boot_file_name, argv[2],
 			      sizeof(net_boot_file_name));

 		break;

 #ifdef CONFIG_CMD_TFTPPUT
 	case 4:
 		if (strict_strtoul(argv[1], 16, &save_addr) < 0 ||
 		    strict_strtoul(argv[2], 16, &save_size) < 0) {
 			printf("Invalid address/size\n");
 			return CMD_RET_USAGE;
 		}
 		copy_filename(net_boot_file_name, argv[3],
 			      sizeof(net_boot_file_name));
 		break;
 #endif
 	default:
 		bootstage_error(BOOTSTAGE_ID_NET_START);
 		return CMD_RET_USAGE;
 	}
 	bootstage_mark(BOOTSTAGE_ID_NET_START);

 	size = net_loop(proto);
 	if (size < 0) {
 		bootstage_error(BOOTSTAGE_ID_NET_NETLOOP_OK);
 		return CMD_RET_FAILURE;
 	}
 	bootstage_mark(BOOTSTAGE_ID_NET_NETLOOP_OK);

 	/* net_loop ok, update environment */
 	netboot_update_env();

 	/* done if no file was loaded (no errors though) */
 	if (size == 0) {
 		bootstage_error(BOOTSTAGE_ID_NET_LOADED);
 		return CMD_RET_SUCCESS;
 	}

 	/* flush cache */
 	flush_cache(load_addr, size);

 	bootstage_mark(BOOTSTAGE_ID_NET_LOADED);

 	rcode = bootm_maybe_autostart(cmdtp, argv[0]);

 	if (rcode == CMD_RET_SUCCESS)
 		bootstage_mark(BOOTSTAGE_ID_NET_DONE);
 	else
 		bootstage_error(BOOTSTAGE_ID_NET_DONE_ERR);
 	return rcode;
 }

 #if defined(CONFIG_CMD_PING)
 static int do_ping(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 {
 	if (argc < 2)
 		return CMD_RET_USAGE;

 	net_ping_ip = string_to_ip(argv[1]);
 	if (net_ping_ip.s_addr == 0)
 		return CMD_RET_USAGE;

 	if (net_loop(PING) < 0) {
 		printf("ping failed; host %s is not alive\n", argv[1]);
 		return CMD_RET_FAILURE;
 	}

 	printf("host %s is alive\n", argv[1]);

 	return CMD_RET_SUCCESS;
 }

 U_BOOT_CMD(
 	ping,	2,	1,	do_ping,
 	"send ICMP ECHO_REQUEST to network host",
 	"pingAddress"
 );
 #endif

 #if defined(CONFIG_CMD_CDP)

 static void cdp_update_env(void)
 {
 	char tmp[16];

 	if (cdp_appliance_vlan != htons(-1)) {
 		printf("CDP offered appliance VLAN %d\n",
 		       ntohs(cdp_appliance_vlan));
 		vlan_to_string(cdp_appliance_vlan, tmp);
 		setenv("vlan", tmp);
 		net_our_vlan = cdp_appliance_vlan;
 	}

 	if (cdp_native_vlan != htons(-1)) {
 		printf("CDP offered native VLAN %d\n", ntohs(cdp_native_vlan));
 		vlan_to_string(cdp_native_vlan, tmp);
 		setenv("nvlan", tmp);
 		net_native_vlan = cdp_native_vlan;
 	}
 }

 int do_cdp(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 {
 	int r;

 	r = net_loop(CDP);
 	if (r < 0) {
 		printf("cdp failed; perhaps not a CISCO switch?\n");
 		return CMD_RET_FAILURE;
 	}

 	cdp_update_env();

 	return CMD_RET_SUCCESS;
 }

 U_BOOT_CMD(
 	cdp,	1,	1,	do_cdp,
 	"Perform CDP network configuration",
 	"\n"
 );
 #endif

 #if defined(CONFIG_CMD_SNTP)
 int do_sntp(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 {
 	char *toff;

 	if (argc < 2) {
 		net_ntp_server = getenv_ip("ntpserverip");
 		if (net_ntp_server.s_addr == 0) {
 			printf("ntpserverip not set\n");
 			return CMD_RET_FAILURE;
 		}
 	} else {
 		net_ntp_server = string_to_ip(argv[1]);
 		if (net_ntp_server.s_addr == 0) {
 			printf("Bad NTP server IP address\n");
 			return CMD_RET_FAILURE;
 		}
 	}

 	toff = getenv("timeoffset");
 	if (toff == NULL)
 		net_ntp_time_offset = 0;
 	else
 		net_ntp_time_offset = simple_strtol(toff, NULL, 10);

 	if (net_loop(SNTP) < 0) {
 		printf("SNTP failed: host %pI4 not responding\n",
 		       &net_ntp_server);
 		return CMD_RET_FAILURE;
 	}

 	return CMD_RET_SUCCESS;
 }

 U_BOOT_CMD(
 	sntp,	2,	1,	do_sntp,
 	"synchronize RTC via network",
 	"[NTP server IP]\n"
 );
 #endif

 #if defined(CONFIG_CMD_DNS)
 int do_dns(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 {
 	if (argc == 1)
 		return CMD_RET_USAGE;

 	/*
 	 * We should check for a valid hostname:
 	 * - Each label must be between 1 and 63 characters long
 	 * - the entire hostname has a maximum of 255 characters
 	 * - only the ASCII letters 'a' through 'z' (case-insensitive),
 	 *   the digits '0' through '9', and the hyphen
 	 * - cannot begin or end with a hyphen
 	 * - no other symbols, punctuation characters, or blank spaces are
 	 *   permitted
 	 * but hey - this is a minimalist implmentation, so only check length
 	 * and let the name server deal with things.
 	 */
 	if (strlen(argv[1]) >= 255) {
 		printf("dns error: hostname too long\n");
 		return CMD_RET_FAILURE;
 	}

 	net_dns_resolve = argv[1];

 	if (argc == 3)
 		net_dns_env_var = argv[2];
 	else
 		net_dns_env_var = NULL;

 	if (net_loop(DNS) < 0) {
 		printf("dns lookup of %s failed, check setup\n", argv[1]);
 		return CMD_RET_FAILURE;
 	}

 	return CMD_RET_SUCCESS;
 }

 U_BOOT_CMD(
 	dns,	3,	1,	do_dns,
 	"lookup the IP of a hostname",
 	"hostname [envvar]"
 );

 #endif	/* CONFIG_CMD_DNS */

 #if defined(CONFIG_CMD_LINK_LOCAL)
 static int do_link_local(cmd_tbl_t *cmdtp, int flag, int argc,
 			char * const argv[])
 {
 	char tmp[22];

 	if (net_loop(LINKLOCAL) < 0)
 		return CMD_RET_FAILURE;

 	net_gateway.s_addr = 0;
 	ip_to_string(net_gateway, tmp);
 	setenv("gatewayip", tmp);

 	ip_to_string(net_netmask, tmp);
 	setenv("netmask", tmp);

 	ip_to_string(net_ip, tmp);
 	setenv("ipaddr", tmp);
 	setenv("llipaddr", tmp); /* store this for next time */

 	return CMD_RET_SUCCESS;
 }

 U_BOOT_CMD(
 	linklocal,	1,	1,	do_link_local,
 	"acquire a network IP address using the link-local protocol",
 	""
 );

 #endif  /* CONFIG_CMD_LINK_LOCAL */
	/*
	* (C) Copyright 2000
	* Wolfgang Denk, DENX Software Engineering, wd@denx.de.
	*
	* SPDX-License-Identifier: GPL-2.0+
	*/

	/*
	* Boot support
	*/
	#include <common.h>
	#include <command.h>
	#include <net.h>

	static int netboot_common(enum proto_t, cmd_tbl_t , int, char const []);

	static int do_bootp(cmd_tbl_t cmdtp, int flag, int argc, char const argv[])
	{
	return netboot_common(BOOTP, cmdtp, argc, argv);
	}

	U_BOOT_CMD(
	bootp, 3, 1, do_bootp,
	"boot image via network using BOOTP/TFTP protocol",
	"[loadAddress] [[hostIPaddr:]bootfilename]"
	);

	int do_tftpb(cmd_tbl_t cmdtp, int flag, int argc, char const argv[])
	{
	int ret;

	bootstage_mark_name(BOOTSTAGE_KERNELREAD_START, "tftp_start");
	ret = netboot_common(TFTPGET, cmdtp, argc, argv);
	bootstage_mark_name(BOOTSTAGE_KERNELREAD_STOP, "tftp_done");
	return ret;
	}

	U_BOOT_CMD(
	tftpboot, 3, 1, do_tftpb,
	"boot image via network using TFTP protocol",
	"[loadAddress] [[hostIPaddr:]bootfilename]"
	);

	#ifdef CONFIG_CMD_TFTPPUT
	int do_tftpput(cmd_tbl_t cmdtp, int flag, int argc, char const argv[])
	{
	return netboot_common(TFTPPUT, cmdtp, argc, argv);
	}

	U_BOOT_CMD(
	tftpput, 4, 1, do_tftpput,
	"TFTP put command, for uploading files to a server",
	"Address Size [[hostIPaddr:]filename]"
	);
	#endif

	#ifdef CONFIG_CMD_TFTPSRV
	static int do_tftpsrv(cmd_tbl_t cmdtp, int flag, int argc, char const argv[])
	{
	return netboot_common(TFTPSRV, cmdtp, argc, argv);
	}

	U_BOOT_CMD(
	tftpsrv, 2, 1, do_tftpsrv,
	"act as a TFTP server and boot the first received file",
	"[loadAddress]\n"
	"Listen for an incoming TFTP transfer, receive a file and boot it.\n"
	"The transfer is aborted if a transfer has not been started after\n"
	"about 50 seconds or if Ctrl-C is pressed."
	);
	#endif


	#ifdef CONFIG_CMD_RARP
	int do_rarpb(cmd_tbl_t cmdtp, int flag, int argc, char const argv[])
	{
	return netboot_common(RARP, cmdtp, argc, argv);
	}

	U_BOOT_CMD(
	rarpboot, 3, 1, do_rarpb,
	"boot image via network using RARP/TFTP protocol",
	"[loadAddress] [[hostIPaddr:]bootfilename]"
	);
	#endif

	#if defined(CONFIG_CMD_DHCP)
	static int do_dhcp(cmd_tbl_t cmdtp, int flag, int argc, char const argv[])
	{
	return netboot_common(DHCP, cmdtp, argc, argv);
	}

	U_BOOT_CMD(
	dhcp, 3, 1, do_dhcp,
	"boot image via network using DHCP/TFTP protocol",
	"[loadAddress] [[hostIPaddr:]bootfilename]"
	);
	#endif

	#if defined(CONFIG_CMD_NFS)
	static int do_nfs(cmd_tbl_t cmdtp, int flag, int argc, char const argv[])
	{
	return netboot_common(NFS, cmdtp, argc, argv);
	}

	U_BOOT_CMD(
	nfs, 3, 1, do_nfs,
	"boot image via network using NFS protocol",
	"[loadAddress] [[hostIPaddr:]bootfilename]"
	);
	#endif

	static void netboot_update_env(void)
	{
	char tmp[22];

	if (net_gateway.s_addr) {
	ip_to_string(net_gateway, tmp);
	setenv("gatewayip", tmp);
	}

	if (net_netmask.s_addr) {
	ip_to_string(net_netmask, tmp);
	setenv("netmask", tmp);
	}

	if (net_hostname[0])
	setenv("hostname", net_hostname);

	if (net_root_path[0])
	setenv("rootpath", net_root_path);

	if (net_ip.s_addr) {
	ip_to_string(net_ip, tmp);
	setenv("ipaddr", tmp);
	}
	#if !defined(CONFIG_BOOTP_SERVERIP)
	/*
	* Only attempt to change serverip if net/bootp.c:BootpCopyNetParams()
	* could have set it
	*/
	if (net_server_ip.s_addr) {
	ip_to_string(net_server_ip, tmp);
	setenv("serverip", tmp);
	}
	#endif
	if (net_dns_server.s_addr) {
	ip_to_string(net_dns_server, tmp);
	setenv("dnsip", tmp);
	}
	#if defined(CONFIG_BOOTP_DNS2)
	if (net_dns_server2.s_addr) {
	ip_to_string(net_dns_server2, tmp);
	setenv("dnsip2", tmp);
	}
	#endif
	if (net_nis_domain[0])
	setenv("domain", net_nis_domain);

	#if defined(CONFIG_CMD_SNTP) && defined(CONFIG_BOOTP_TIMEOFFSET)
	if (net_ntp_time_offset) {
	sprintf(tmp, "%d", net_ntp_time_offset);
	setenv("timeoffset", tmp);
	}
	#endif
	#if defined(CONFIG_CMD_SNTP) && defined(CONFIG_BOOTP_NTPSERVER)
	if (net_ntp_server.s_addr) {
	ip_to_string(net_ntp_server, tmp);
	setenv("ntpserverip", tmp);
	}
	#endif
	}

	static int netboot_common(enum proto_t proto, cmd_tbl_t *cmdtp, int argc,
	char * const argv[])
	{
	char *s;
	char *end;
	int rcode = 0;
	int size;
	ulong addr;

	/* pre-set load_addr */
	s = getenv("loadaddr");
	if (s != NULL)
	load_addr = simple_strtoul(s, NULL, 16);

	switch (argc) {
	case 1:
	break;

	case 2: /*
	* Only one arg - accept two forms:
	* Just load address, or just boot file name. The latter
	* form must be written in a format which can not be
	* mis-interpreted as a valid number.
	*/
	addr = simple_strtoul(argv[1], &end, 16);
	if (end == (argv[1] + strlen(argv[1])))
	load_addr = addr;
	else
	copy_filename(net_boot_file_name, argv[1],
	sizeof(net_boot_file_name));
	break;

	case 3:
	load_addr = simple_strtoul(argv[1], NULL, 16);
	copy_filename(net_boot_file_name, argv[2],
	sizeof(net_boot_file_name));

	break;

	#ifdef CONFIG_CMD_TFTPPUT
	case 4:
	if (strict_strtoul(argv[1], 16, &save_addr) < 0 \|\|
	strict_strtoul(argv[2], 16, &save_size) < 0) {
	printf("Invalid address/size\n");
	return CMD_RET_USAGE;
	}
	copy_filename(net_boot_file_name, argv[3],
	sizeof(net_boot_file_name));
	break;
	#endif
	default:
	bootstage_error(BOOTSTAGE_ID_NET_START);
	return CMD_RET_USAGE;
	}
	bootstage_mark(BOOTSTAGE_ID_NET_START);

	size = net_loop(proto);
	if (size < 0) {
	bootstage_error(BOOTSTAGE_ID_NET_NETLOOP_OK);
	return CMD_RET_FAILURE;
	}
	bootstage_mark(BOOTSTAGE_ID_NET_NETLOOP_OK);

	/* net_loop ok, update environment */
	netboot_update_env();

	/* done if no file was loaded (no errors though) */
	if (size == 0) {
	bootstage_error(BOOTSTAGE_ID_NET_LOADED);
	return CMD_RET_SUCCESS;
	}

	/* flush cache */
	flush_cache(load_addr, size);

	bootstage_mark(BOOTSTAGE_ID_NET_LOADED);

	rcode = bootm_maybe_autostart(cmdtp, argv[0]);

	if (rcode == CMD_RET_SUCCESS)
	bootstage_mark(BOOTSTAGE_ID_NET_DONE);
	else
	bootstage_error(BOOTSTAGE_ID_NET_DONE_ERR);
	return rcode;
	}

	#if defined(CONFIG_CMD_PING)
	static int do_ping(cmd_tbl_t cmdtp, int flag, int argc, char const argv[])
	{
	if (argc < 2)
	return CMD_RET_USAGE;

	net_ping_ip = string_to_ip(argv[1]);
	if (net_ping_ip.s_addr == 0)
	return CMD_RET_USAGE;

	if (net_loop(PING) < 0) {
	printf("ping failed; host %s is not alive\n", argv[1]);
	return CMD_RET_FAILURE;
	}

	printf("host %s is alive\n", argv[1]);

	return CMD_RET_SUCCESS;
	}

	U_BOOT_CMD(
	ping, 2, 1, do_ping,
	"send ICMP ECHO_REQUEST to network host",
	"pingAddress"
	);
	#endif

	#if defined(CONFIG_CMD_CDP)

	static void cdp_update_env(void)
	{
	char tmp[16];

	if (cdp_appliance_vlan != htons(-1)) {
	printf("CDP offered appliance VLAN %d\n",
	ntohs(cdp_appliance_vlan));
	vlan_to_string(cdp_appliance_vlan, tmp);
	setenv("vlan", tmp);
	net_our_vlan = cdp_appliance_vlan;
	}

	if (cdp_native_vlan != htons(-1)) {
	printf("CDP offered native VLAN %d\n", ntohs(cdp_native_vlan));
	vlan_to_string(cdp_native_vlan, tmp);
	setenv("nvlan", tmp);
	net_native_vlan = cdp_native_vlan;
	}
	}

	int do_cdp(cmd_tbl_t cmdtp, int flag, int argc, char const argv[])
	{
	int r;

	r = net_loop(CDP);
	if (r < 0) {
	printf("cdp failed; perhaps not a CISCO switch?\n");
	return CMD_RET_FAILURE;
	}

	cdp_update_env();

	return CMD_RET_SUCCESS;
	}

	U_BOOT_CMD(
	cdp, 1, 1, do_cdp,
	"Perform CDP network configuration",
	"\n"
	);
	#endif

	#if defined(CONFIG_CMD_SNTP)
	int do_sntp(cmd_tbl_t cmdtp, int flag, int argc, char const argv[])
	{
	char *toff;

	if (argc < 2) {
	net_ntp_server = getenv_ip("ntpserverip");
	if (net_ntp_server.s_addr == 0) {
	printf("ntpserverip not set\n");
	return CMD_RET_FAILURE;
	}
	} else {
	net_ntp_server = string_to_ip(argv[1]);
	if (net_ntp_server.s_addr == 0) {
	printf("Bad NTP server IP address\n");
	return CMD_RET_FAILURE;
	}
	}

	toff = getenv("timeoffset");
	if (toff == NULL)
	net_ntp_time_offset = 0;
	else
	net_ntp_time_offset = simple_strtol(toff, NULL, 10);

	if (net_loop(SNTP) < 0) {
	printf("SNTP failed: host %pI4 not responding\n",
	&net_ntp_server);
	return CMD_RET_FAILURE;
	}

	return CMD_RET_SUCCESS;
	}

	U_BOOT_CMD(
	sntp, 2, 1, do_sntp,
	"synchronize RTC via network",
	"[NTP server IP]\n"
	);
	#endif

	#if defined(CONFIG_CMD_DNS)
	int do_dns(cmd_tbl_t cmdtp, int flag, int argc, char const argv[])
	{
	if (argc == 1)
	return CMD_RET_USAGE;

	/*
	* We should check for a valid hostname:
	* - Each label must be between 1 and 63 characters long
	* - the entire hostname has a maximum of 255 characters
	* - only the ASCII letters 'a' through 'z' (case-insensitive),
	* the digits '0' through '9', and the hyphen
	* - cannot begin or end with a hyphen
	* - no other symbols, punctuation characters, or blank spaces are
	* permitted
	* but hey - this is a minimalist implmentation, so only check length
	* and let the name server deal with things.
	*/
	if (strlen(argv[1]) >= 255) {
	printf("dns error: hostname too long\n");
	return CMD_RET_FAILURE;
	}

	net_dns_resolve = argv[1];

	if (argc == 3)
	net_dns_env_var = argv[2];
	else
	net_dns_env_var = NULL;

	if (net_loop(DNS) < 0) {
	printf("dns lookup of %s failed, check setup\n", argv[1]);
	return CMD_RET_FAILURE;
	}

	return CMD_RET_SUCCESS;
	}

	U_BOOT_CMD(
	dns, 3, 1, do_dns,
	"lookup the IP of a hostname",
	"hostname [envvar]"
	);

	#endif /* CONFIG_CMD_DNS */

	#if defined(CONFIG_CMD_LINK_LOCAL)
	static int do_link_local(cmd_tbl_t *cmdtp, int flag, int argc,
	char * const argv[])
	{
	char tmp[22];

	if (net_loop(LINKLOCAL) < 0)
	return CMD_RET_FAILURE;

	net_gateway.s_addr = 0;
	ip_to_string(net_gateway, tmp);
	setenv("gatewayip", tmp);

	ip_to_string(net_netmask, tmp);
	setenv("netmask", tmp);

	ip_to_string(net_ip, tmp);
	setenv("ipaddr", tmp);
	setenv("llipaddr", tmp); /* store this for next time */

	return CMD_RET_SUCCESS;
	}

	U_BOOT_CMD(
	linklocal, 1, 1, do_link_local,
	"acquire a network IP address using the link-local protocol",
	""
	);

	#endif /* CONFIG_CMD_LINK_LOCAL */