xref: /openbmc/u-boot/net/net.c (revision 9d1b2987)
1 /*
2  *	Copied from Linux Monitor (LiMon) - Networking.
3  *
4  *	Copyright 1994 - 2000 Neil Russell.
5  *	(See License)
6  *	Copyright 2000 Roland Borde
7  *	Copyright 2000 Paolo Scaffardi
8  *	Copyright 2000-2002 Wolfgang Denk, wd@denx.de
9  *	SPDX-License-Identifier:	GPL-2.0
10  */
11 
12 /*
13  * General Desription:
14  *
15  * The user interface supports commands for BOOTP, RARP, and TFTP.
16  * Also, we support ARP internally. Depending on available data,
17  * these interact as follows:
18  *
19  * BOOTP:
20  *
21  *	Prerequisites:	- own ethernet address
22  *	We want:	- own IP address
23  *			- TFTP server IP address
24  *			- name of bootfile
25  *	Next step:	ARP
26  *
27  * LINK_LOCAL:
28  *
29  *	Prerequisites:	- own ethernet address
30  *	We want:	- own IP address
31  *	Next step:	ARP
32  *
33  * RARP:
34  *
35  *	Prerequisites:	- own ethernet address
36  *	We want:	- own IP address
37  *			- TFTP server IP address
38  *	Next step:	ARP
39  *
40  * ARP:
41  *
42  *	Prerequisites:	- own ethernet address
43  *			- own IP address
44  *			- TFTP server IP address
45  *	We want:	- TFTP server ethernet address
46  *	Next step:	TFTP
47  *
48  * DHCP:
49  *
50  *     Prerequisites:	- own ethernet address
51  *     We want:		- IP, Netmask, ServerIP, Gateway IP
52  *			- bootfilename, lease time
53  *     Next step:	- TFTP
54  *
55  * TFTP:
56  *
57  *	Prerequisites:	- own ethernet address
58  *			- own IP address
59  *			- TFTP server IP address
60  *			- TFTP server ethernet address
61  *			- name of bootfile (if unknown, we use a default name
62  *			  derived from our own IP address)
63  *	We want:	- load the boot file
64  *	Next step:	none
65  *
66  * NFS:
67  *
68  *	Prerequisites:	- own ethernet address
69  *			- own IP address
70  *			- name of bootfile (if unknown, we use a default name
71  *			  derived from our own IP address)
72  *	We want:	- load the boot file
73  *	Next step:	none
74  *
75  * SNTP:
76  *
77  *	Prerequisites:	- own ethernet address
78  *			- own IP address
79  *	We want:	- network time
80  *	Next step:	none
81  */
82 
83 
84 #include <common.h>
85 #include <command.h>
86 #include <environment.h>
87 #include <errno.h>
88 #include <net.h>
89 #include <net/tftp.h>
90 #if defined(CONFIG_STATUS_LED)
91 #include <miiphy.h>
92 #include <status_led.h>
93 #endif
94 #include <watchdog.h>
95 #include <linux/compiler.h>
96 #include "arp.h"
97 #include "bootp.h"
98 #include "cdp.h"
99 #if defined(CONFIG_CMD_DNS)
100 #include "dns.h"
101 #endif
102 #include "link_local.h"
103 #include "nfs.h"
104 #include "ping.h"
105 #include "rarp.h"
106 #if defined(CONFIG_CMD_SNTP)
107 #include "sntp.h"
108 #endif
109 
110 DECLARE_GLOBAL_DATA_PTR;
111 
112 /** BOOTP EXTENTIONS **/
113 
114 /* Our subnet mask (0=unknown) */
115 struct in_addr net_netmask;
116 /* Our gateways IP address */
117 struct in_addr net_gateway;
118 /* Our DNS IP address */
119 struct in_addr net_dns_server;
120 #if defined(CONFIG_BOOTP_DNS2)
121 /* Our 2nd DNS IP address */
122 struct in_addr net_dns_server2;
123 #endif
124 
125 #ifdef CONFIG_MCAST_TFTP	/* Multicast TFTP */
126 struct in_addr net_mcast_addr;
127 #endif
128 
129 /** END OF BOOTP EXTENTIONS **/
130 
131 /* Our ethernet address */
132 u8 net_ethaddr[6];
133 /* Boot server enet address */
134 u8 net_server_ethaddr[6];
135 /* Our IP addr (0 = unknown) */
136 struct in_addr	net_ip;
137 /* Server IP addr (0 = unknown) */
138 struct in_addr	net_server_ip;
139 /* Current receive packet */
140 uchar *net_rx_packet;
141 /* Current rx packet length */
142 int		net_rx_packet_len;
143 /* IP packet ID */
144 static unsigned	net_ip_id;
145 /* Ethernet bcast address */
146 const u8 net_bcast_ethaddr[6] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
147 const u8 net_null_ethaddr[6];
148 #ifdef CONFIG_API
149 void (*push_packet)(void *, int len) = 0;
150 #endif
151 /* Network loop state */
152 enum net_loop_state net_state;
153 /* Tried all network devices */
154 int		net_restart_wrap;
155 /* Network loop restarted */
156 static int	net_restarted;
157 /* At least one device configured */
158 static int	net_dev_exists;
159 
160 /* XXX in both little & big endian machines 0xFFFF == ntohs(-1) */
161 /* default is without VLAN */
162 ushort		net_our_vlan = 0xFFFF;
163 /* ditto */
164 ushort		net_native_vlan = 0xFFFF;
165 
166 /* Boot File name */
167 char net_boot_file_name[128];
168 /* The actual transferred size of the bootfile (in bytes) */
169 u32 net_boot_file_size;
170 /* Boot file size in blocks as reported by the DHCP server */
171 u32 net_boot_file_expected_size_in_blocks;
172 
173 #if defined(CONFIG_CMD_SNTP)
174 /* NTP server IP address */
175 struct in_addr	net_ntp_server;
176 /* offset time from UTC */
177 int		net_ntp_time_offset;
178 #endif
179 
180 static uchar net_pkt_buf[(PKTBUFSRX+1) * PKTSIZE_ALIGN + PKTALIGN];
181 /* Receive packets */
182 uchar *net_rx_packets[PKTBUFSRX];
183 /* Current UDP RX packet handler */
184 static rxhand_f *udp_packet_handler;
185 /* Current ARP RX packet handler */
186 static rxhand_f *arp_packet_handler;
187 #ifdef CONFIG_CMD_TFTPPUT
188 /* Current ICMP rx handler */
189 static rxhand_icmp_f *packet_icmp_handler;
190 #endif
191 /* Current timeout handler */
192 static thand_f *time_handler;
193 /* Time base value */
194 static ulong	time_start;
195 /* Current timeout value */
196 static ulong	time_delta;
197 /* THE transmit packet */
198 uchar *net_tx_packet;
199 
200 static int net_check_prereq(enum proto_t protocol);
201 
202 static int net_try_count;
203 
204 int __maybe_unused net_busy_flag;
205 
206 /**********************************************************************/
207 
208 static int on_bootfile(const char *name, const char *value, enum env_op op,
209 	int flags)
210 {
211 	if (flags & H_PROGRAMMATIC)
212 		return 0;
213 
214 	switch (op) {
215 	case env_op_create:
216 	case env_op_overwrite:
217 		copy_filename(net_boot_file_name, value,
218 			      sizeof(net_boot_file_name));
219 		break;
220 	default:
221 		break;
222 	}
223 
224 	return 0;
225 }
226 U_BOOT_ENV_CALLBACK(bootfile, on_bootfile);
227 
228 static int on_ipaddr(const char *name, const char *value, enum env_op op,
229 	int flags)
230 {
231 	if (flags & H_PROGRAMMATIC)
232 		return 0;
233 
234 	net_ip = string_to_ip(value);
235 
236 	return 0;
237 }
238 U_BOOT_ENV_CALLBACK(ipaddr, on_ipaddr);
239 
240 static int on_gatewayip(const char *name, const char *value, enum env_op op,
241 	int flags)
242 {
243 	if (flags & H_PROGRAMMATIC)
244 		return 0;
245 
246 	net_gateway = string_to_ip(value);
247 
248 	return 0;
249 }
250 U_BOOT_ENV_CALLBACK(gatewayip, on_gatewayip);
251 
252 static int on_netmask(const char *name, const char *value, enum env_op op,
253 	int flags)
254 {
255 	if (flags & H_PROGRAMMATIC)
256 		return 0;
257 
258 	net_netmask = string_to_ip(value);
259 
260 	return 0;
261 }
262 U_BOOT_ENV_CALLBACK(netmask, on_netmask);
263 
264 static int on_serverip(const char *name, const char *value, enum env_op op,
265 	int flags)
266 {
267 	if (flags & H_PROGRAMMATIC)
268 		return 0;
269 
270 	net_server_ip = string_to_ip(value);
271 
272 	return 0;
273 }
274 U_BOOT_ENV_CALLBACK(serverip, on_serverip);
275 
276 static int on_nvlan(const char *name, const char *value, enum env_op op,
277 	int flags)
278 {
279 	if (flags & H_PROGRAMMATIC)
280 		return 0;
281 
282 	net_native_vlan = string_to_vlan(value);
283 
284 	return 0;
285 }
286 U_BOOT_ENV_CALLBACK(nvlan, on_nvlan);
287 
288 static int on_vlan(const char *name, const char *value, enum env_op op,
289 	int flags)
290 {
291 	if (flags & H_PROGRAMMATIC)
292 		return 0;
293 
294 	net_our_vlan = string_to_vlan(value);
295 
296 	return 0;
297 }
298 U_BOOT_ENV_CALLBACK(vlan, on_vlan);
299 
300 #if defined(CONFIG_CMD_DNS)
301 static int on_dnsip(const char *name, const char *value, enum env_op op,
302 	int flags)
303 {
304 	if (flags & H_PROGRAMMATIC)
305 		return 0;
306 
307 	net_dns_server = string_to_ip(value);
308 
309 	return 0;
310 }
311 U_BOOT_ENV_CALLBACK(dnsip, on_dnsip);
312 #endif
313 
314 /*
315  * Check if autoload is enabled. If so, use either NFS or TFTP to download
316  * the boot file.
317  */
318 void net_auto_load(void)
319 {
320 #if defined(CONFIG_CMD_NFS)
321 	const char *s = getenv("autoload");
322 
323 	if (s != NULL && strcmp(s, "NFS") == 0) {
324 		/*
325 		 * Use NFS to load the bootfile.
326 		 */
327 		nfs_start();
328 		return;
329 	}
330 #endif
331 	if (getenv_yesno("autoload") == 0) {
332 		/*
333 		 * Just use BOOTP/RARP to configure system;
334 		 * Do not use TFTP to load the bootfile.
335 		 */
336 		net_set_state(NETLOOP_SUCCESS);
337 		return;
338 	}
339 	tftp_start(TFTPGET);
340 }
341 
342 static void net_init_loop(void)
343 {
344 	if (eth_get_dev())
345 		memcpy(net_ethaddr, eth_get_ethaddr(), 6);
346 
347 	return;
348 }
349 
350 static void net_clear_handlers(void)
351 {
352 	net_set_udp_handler(NULL);
353 	net_set_arp_handler(NULL);
354 	net_set_timeout_handler(0, NULL);
355 }
356 
357 static void net_cleanup_loop(void)
358 {
359 	net_clear_handlers();
360 }
361 
362 void net_init(void)
363 {
364 	static int first_call = 1;
365 
366 	if (first_call) {
367 		/*
368 		 *	Setup packet buffers, aligned correctly.
369 		 */
370 		int i;
371 
372 		net_tx_packet = &net_pkt_buf[0] + (PKTALIGN - 1);
373 		net_tx_packet -= (ulong)net_tx_packet % PKTALIGN;
374 		for (i = 0; i < PKTBUFSRX; i++) {
375 			net_rx_packets[i] = net_tx_packet +
376 				(i + 1) * PKTSIZE_ALIGN;
377 		}
378 		arp_init();
379 		net_clear_handlers();
380 
381 		/* Only need to setup buffer pointers once. */
382 		first_call = 0;
383 	}
384 
385 	net_init_loop();
386 }
387 
388 /**********************************************************************/
389 /*
390  *	Main network processing loop.
391  */
392 
393 int net_loop(enum proto_t protocol)
394 {
395 	int ret = -EINVAL;
396 
397 	net_restarted = 0;
398 	net_dev_exists = 0;
399 	net_try_count = 1;
400 	debug_cond(DEBUG_INT_STATE, "--- net_loop Entry\n");
401 
402 	bootstage_mark_name(BOOTSTAGE_ID_ETH_START, "eth_start");
403 	net_init();
404 	if (eth_is_on_demand_init() || protocol != NETCONS) {
405 		eth_halt();
406 		eth_set_current();
407 		ret = eth_init();
408 		if (ret < 0) {
409 			eth_halt();
410 			return ret;
411 		}
412 	} else {
413 		eth_init_state_only();
414 	}
415 restart:
416 #ifdef CONFIG_USB_KEYBOARD
417 	net_busy_flag = 0;
418 #endif
419 	net_set_state(NETLOOP_CONTINUE);
420 
421 	/*
422 	 *	Start the ball rolling with the given start function.  From
423 	 *	here on, this code is a state machine driven by received
424 	 *	packets and timer events.
425 	 */
426 	debug_cond(DEBUG_INT_STATE, "--- net_loop Init\n");
427 	net_init_loop();
428 
429 	switch (net_check_prereq(protocol)) {
430 	case 1:
431 		/* network not configured */
432 		eth_halt();
433 		return -ENODEV;
434 
435 	case 2:
436 		/* network device not configured */
437 		break;
438 
439 	case 0:
440 		net_dev_exists = 1;
441 		net_boot_file_size = 0;
442 		switch (protocol) {
443 		case TFTPGET:
444 #ifdef CONFIG_CMD_TFTPPUT
445 		case TFTPPUT:
446 #endif
447 			/* always use ARP to get server ethernet address */
448 			tftp_start(protocol);
449 			break;
450 #ifdef CONFIG_CMD_TFTPSRV
451 		case TFTPSRV:
452 			tftp_start_server();
453 			break;
454 #endif
455 #if defined(CONFIG_CMD_DHCP)
456 		case DHCP:
457 			bootp_reset();
458 			net_ip.s_addr = 0;
459 			dhcp_request();		/* Basically same as BOOTP */
460 			break;
461 #endif
462 
463 		case BOOTP:
464 			bootp_reset();
465 			net_ip.s_addr = 0;
466 			bootp_request();
467 			break;
468 
469 #if defined(CONFIG_CMD_RARP)
470 		case RARP:
471 			rarp_try = 0;
472 			net_ip.s_addr = 0;
473 			rarp_request();
474 			break;
475 #endif
476 #if defined(CONFIG_CMD_PING)
477 		case PING:
478 			ping_start();
479 			break;
480 #endif
481 #if defined(CONFIG_CMD_NFS)
482 		case NFS:
483 			nfs_start();
484 			break;
485 #endif
486 #if defined(CONFIG_CMD_CDP)
487 		case CDP:
488 			cdp_start();
489 			break;
490 #endif
491 #if defined(CONFIG_NETCONSOLE) && !(CONFIG_SPL_BUILD)
492 		case NETCONS:
493 			nc_start();
494 			break;
495 #endif
496 #if defined(CONFIG_CMD_SNTP)
497 		case SNTP:
498 			sntp_start();
499 			break;
500 #endif
501 #if defined(CONFIG_CMD_DNS)
502 		case DNS:
503 			dns_start();
504 			break;
505 #endif
506 #if defined(CONFIG_CMD_LINK_LOCAL)
507 		case LINKLOCAL:
508 			link_local_start();
509 			break;
510 #endif
511 		default:
512 			break;
513 		}
514 
515 		break;
516 	}
517 
518 #if defined(CONFIG_MII) || defined(CONFIG_CMD_MII)
519 #if	defined(CONFIG_SYS_FAULT_ECHO_LINK_DOWN)	&& \
520 	defined(CONFIG_STATUS_LED)			&& \
521 	defined(STATUS_LED_RED)
522 	/*
523 	 * Echo the inverted link state to the fault LED.
524 	 */
525 	if (miiphy_link(eth_get_dev()->name, CONFIG_SYS_FAULT_MII_ADDR))
526 		status_led_set(STATUS_LED_RED, STATUS_LED_OFF);
527 	else
528 		status_led_set(STATUS_LED_RED, STATUS_LED_ON);
529 #endif /* CONFIG_SYS_FAULT_ECHO_LINK_DOWN, ... */
530 #endif /* CONFIG_MII, ... */
531 #ifdef CONFIG_USB_KEYBOARD
532 	net_busy_flag = 1;
533 #endif
534 
535 	/*
536 	 *	Main packet reception loop.  Loop receiving packets until
537 	 *	someone sets `net_state' to a state that terminates.
538 	 */
539 	for (;;) {
540 		WATCHDOG_RESET();
541 #ifdef CONFIG_SHOW_ACTIVITY
542 		show_activity(1);
543 #endif
544 		/*
545 		 *	Check the ethernet for a new packet.  The ethernet
546 		 *	receive routine will process it.
547 		 *	Most drivers return the most recent packet size, but not
548 		 *	errors that may have happened.
549 		 */
550 		eth_rx();
551 
552 		/*
553 		 *	Abort if ctrl-c was pressed.
554 		 */
555 		if (ctrlc()) {
556 			/* cancel any ARP that may not have completed */
557 			net_arp_wait_packet_ip.s_addr = 0;
558 
559 			net_cleanup_loop();
560 			eth_halt();
561 			/* Invalidate the last protocol */
562 			eth_set_last_protocol(BOOTP);
563 
564 			puts("\nAbort\n");
565 			/* include a debug print as well incase the debug
566 			   messages are directed to stderr */
567 			debug_cond(DEBUG_INT_STATE, "--- net_loop Abort!\n");
568 			ret = -EINTR;
569 			goto done;
570 		}
571 
572 		arp_timeout_check();
573 
574 		/*
575 		 *	Check for a timeout, and run the timeout handler
576 		 *	if we have one.
577 		 */
578 		if (time_handler &&
579 		    ((get_timer(0) - time_start) > time_delta)) {
580 			thand_f *x;
581 
582 #if defined(CONFIG_MII) || defined(CONFIG_CMD_MII)
583 #if	defined(CONFIG_SYS_FAULT_ECHO_LINK_DOWN)	&& \
584 	defined(CONFIG_STATUS_LED)			&& \
585 	defined(STATUS_LED_RED)
586 			/*
587 			 * Echo the inverted link state to the fault LED.
588 			 */
589 			if (miiphy_link(eth_get_dev()->name,
590 					CONFIG_SYS_FAULT_MII_ADDR))
591 				status_led_set(STATUS_LED_RED, STATUS_LED_OFF);
592 			else
593 				status_led_set(STATUS_LED_RED, STATUS_LED_ON);
594 #endif /* CONFIG_SYS_FAULT_ECHO_LINK_DOWN, ... */
595 #endif /* CONFIG_MII, ... */
596 			debug_cond(DEBUG_INT_STATE, "--- net_loop timeout\n");
597 			x = time_handler;
598 			time_handler = (thand_f *)0;
599 			(*x)();
600 		}
601 
602 		if (net_state == NETLOOP_FAIL)
603 			ret = net_start_again();
604 
605 		switch (net_state) {
606 		case NETLOOP_RESTART:
607 			net_restarted = 1;
608 			goto restart;
609 
610 		case NETLOOP_SUCCESS:
611 			net_cleanup_loop();
612 			if (net_boot_file_size > 0) {
613 				printf("Bytes transferred = %d (%x hex)\n",
614 				       net_boot_file_size, net_boot_file_size);
615 				setenv_hex("filesize", net_boot_file_size);
616 				setenv_hex("fileaddr", load_addr);
617 			}
618 			if (protocol != NETCONS)
619 				eth_halt();
620 			else
621 				eth_halt_state_only();
622 
623 			eth_set_last_protocol(protocol);
624 
625 			ret = net_boot_file_size;
626 			debug_cond(DEBUG_INT_STATE, "--- net_loop Success!\n");
627 			goto done;
628 
629 		case NETLOOP_FAIL:
630 			net_cleanup_loop();
631 			/* Invalidate the last protocol */
632 			eth_set_last_protocol(BOOTP);
633 			debug_cond(DEBUG_INT_STATE, "--- net_loop Fail!\n");
634 			goto done;
635 
636 		case NETLOOP_CONTINUE:
637 			continue;
638 		}
639 	}
640 
641 done:
642 #ifdef CONFIG_USB_KEYBOARD
643 	net_busy_flag = 0;
644 #endif
645 #ifdef CONFIG_CMD_TFTPPUT
646 	/* Clear out the handlers */
647 	net_set_udp_handler(NULL);
648 	net_set_icmp_handler(NULL);
649 #endif
650 	return ret;
651 }
652 
653 /**********************************************************************/
654 
655 static void start_again_timeout_handler(void)
656 {
657 	net_set_state(NETLOOP_RESTART);
658 }
659 
660 int net_start_again(void)
661 {
662 	char *nretry;
663 	int retry_forever = 0;
664 	unsigned long retrycnt = 0;
665 	int ret;
666 
667 	nretry = getenv("netretry");
668 	if (nretry) {
669 		if (!strcmp(nretry, "yes"))
670 			retry_forever = 1;
671 		else if (!strcmp(nretry, "no"))
672 			retrycnt = 0;
673 		else if (!strcmp(nretry, "once"))
674 			retrycnt = 1;
675 		else
676 			retrycnt = simple_strtoul(nretry, NULL, 0);
677 	} else {
678 		retrycnt = 0;
679 		retry_forever = 0;
680 	}
681 
682 	if ((!retry_forever) && (net_try_count >= retrycnt)) {
683 		eth_halt();
684 		net_set_state(NETLOOP_FAIL);
685 		/*
686 		 * We don't provide a way for the protocol to return an error,
687 		 * but this is almost always the reason.
688 		 */
689 		return -ETIMEDOUT;
690 	}
691 
692 	net_try_count++;
693 
694 	eth_halt();
695 #if !defined(CONFIG_NET_DO_NOT_TRY_ANOTHER)
696 	eth_try_another(!net_restarted);
697 #endif
698 	ret = eth_init();
699 	if (net_restart_wrap) {
700 		net_restart_wrap = 0;
701 		if (net_dev_exists) {
702 			net_set_timeout_handler(10000UL,
703 						start_again_timeout_handler);
704 			net_set_udp_handler(NULL);
705 		} else {
706 			net_set_state(NETLOOP_FAIL);
707 		}
708 	} else {
709 		net_set_state(NETLOOP_RESTART);
710 	}
711 	return ret;
712 }
713 
714 /**********************************************************************/
715 /*
716  *	Miscelaneous bits.
717  */
718 
719 static void dummy_handler(uchar *pkt, unsigned dport,
720 			struct in_addr sip, unsigned sport,
721 			unsigned len)
722 {
723 }
724 
725 rxhand_f *net_get_udp_handler(void)
726 {
727 	return udp_packet_handler;
728 }
729 
730 void net_set_udp_handler(rxhand_f *f)
731 {
732 	debug_cond(DEBUG_INT_STATE, "--- net_loop UDP handler set (%p)\n", f);
733 	if (f == NULL)
734 		udp_packet_handler = dummy_handler;
735 	else
736 		udp_packet_handler = f;
737 }
738 
739 rxhand_f *net_get_arp_handler(void)
740 {
741 	return arp_packet_handler;
742 }
743 
744 void net_set_arp_handler(rxhand_f *f)
745 {
746 	debug_cond(DEBUG_INT_STATE, "--- net_loop ARP handler set (%p)\n", f);
747 	if (f == NULL)
748 		arp_packet_handler = dummy_handler;
749 	else
750 		arp_packet_handler = f;
751 }
752 
753 #ifdef CONFIG_CMD_TFTPPUT
754 void net_set_icmp_handler(rxhand_icmp_f *f)
755 {
756 	packet_icmp_handler = f;
757 }
758 #endif
759 
760 void net_set_timeout_handler(ulong iv, thand_f *f)
761 {
762 	if (iv == 0) {
763 		debug_cond(DEBUG_INT_STATE,
764 			   "--- net_loop timeout handler cancelled\n");
765 		time_handler = (thand_f *)0;
766 	} else {
767 		debug_cond(DEBUG_INT_STATE,
768 			   "--- net_loop timeout handler set (%p)\n", f);
769 		time_handler = f;
770 		time_start = get_timer(0);
771 		time_delta = iv * CONFIG_SYS_HZ / 1000;
772 	}
773 }
774 
775 int net_send_udp_packet(uchar *ether, struct in_addr dest, int dport, int sport,
776 		int payload_len)
777 {
778 	uchar *pkt;
779 	int eth_hdr_size;
780 	int pkt_hdr_size;
781 
782 	/* make sure the net_tx_packet is initialized (net_init() was called) */
783 	assert(net_tx_packet != NULL);
784 	if (net_tx_packet == NULL)
785 		return -1;
786 
787 	/* convert to new style broadcast */
788 	if (dest.s_addr == 0)
789 		dest.s_addr = 0xFFFFFFFF;
790 
791 	/* if broadcast, make the ether address a broadcast and don't do ARP */
792 	if (dest.s_addr == 0xFFFFFFFF)
793 		ether = (uchar *)net_bcast_ethaddr;
794 
795 	pkt = (uchar *)net_tx_packet;
796 
797 	eth_hdr_size = net_set_ether(pkt, ether, PROT_IP);
798 	pkt += eth_hdr_size;
799 	net_set_udp_header(pkt, dest, dport, sport, payload_len);
800 	pkt_hdr_size = eth_hdr_size + IP_UDP_HDR_SIZE;
801 
802 	/* if MAC address was not discovered yet, do an ARP request */
803 	if (memcmp(ether, net_null_ethaddr, 6) == 0) {
804 		debug_cond(DEBUG_DEV_PKT, "sending ARP for %pI4\n", &dest);
805 
806 		/* save the ip and eth addr for the packet to send after arp */
807 		net_arp_wait_packet_ip = dest;
808 		arp_wait_packet_ethaddr = ether;
809 
810 		/* size of the waiting packet */
811 		arp_wait_tx_packet_size = pkt_hdr_size + payload_len;
812 
813 		/* and do the ARP request */
814 		arp_wait_try = 1;
815 		arp_wait_timer_start = get_timer(0);
816 		arp_request();
817 		return 1;	/* waiting */
818 	} else {
819 		debug_cond(DEBUG_DEV_PKT, "sending UDP to %pI4/%pM\n",
820 			   &dest, ether);
821 		net_send_packet(net_tx_packet, pkt_hdr_size + payload_len);
822 		return 0;	/* transmitted */
823 	}
824 }
825 
826 #ifdef CONFIG_IP_DEFRAG
827 /*
828  * This function collects fragments in a single packet, according
829  * to the algorithm in RFC815. It returns NULL or the pointer to
830  * a complete packet, in static storage
831  */
832 #ifndef CONFIG_NET_MAXDEFRAG
833 #define CONFIG_NET_MAXDEFRAG 16384
834 #endif
835 /*
836  * MAXDEFRAG, above, is chosen in the config file and  is real data
837  * so we need to add the NFS overhead, which is more than TFTP.
838  * To use sizeof in the internal unnamed structures, we need a real
839  * instance (can't do "sizeof(struct rpc_t.u.reply))", unfortunately).
840  * The compiler doesn't complain nor allocates the actual structure
841  */
842 static struct rpc_t rpc_specimen;
843 #define IP_PKTSIZE (CONFIG_NET_MAXDEFRAG + sizeof(rpc_specimen.u.reply))
844 
845 #define IP_MAXUDP (IP_PKTSIZE - IP_HDR_SIZE)
846 
847 /*
848  * this is the packet being assembled, either data or frag control.
849  * Fragments go by 8 bytes, so this union must be 8 bytes long
850  */
851 struct hole {
852 	/* first_byte is address of this structure */
853 	u16 last_byte;	/* last byte in this hole + 1 (begin of next hole) */
854 	u16 next_hole;	/* index of next (in 8-b blocks), 0 == none */
855 	u16 prev_hole;	/* index of prev, 0 == none */
856 	u16 unused;
857 };
858 
859 static struct ip_udp_hdr *__net_defragment(struct ip_udp_hdr *ip, int *lenp)
860 {
861 	static uchar pkt_buff[IP_PKTSIZE] __aligned(PKTALIGN);
862 	static u16 first_hole, total_len;
863 	struct hole *payload, *thisfrag, *h, *newh;
864 	struct ip_udp_hdr *localip = (struct ip_udp_hdr *)pkt_buff;
865 	uchar *indata = (uchar *)ip;
866 	int offset8, start, len, done = 0;
867 	u16 ip_off = ntohs(ip->ip_off);
868 
869 	/* payload starts after IP header, this fragment is in there */
870 	payload = (struct hole *)(pkt_buff + IP_HDR_SIZE);
871 	offset8 =  (ip_off & IP_OFFS);
872 	thisfrag = payload + offset8;
873 	start = offset8 * 8;
874 	len = ntohs(ip->ip_len) - IP_HDR_SIZE;
875 
876 	if (start + len > IP_MAXUDP) /* fragment extends too far */
877 		return NULL;
878 
879 	if (!total_len || localip->ip_id != ip->ip_id) {
880 		/* new (or different) packet, reset structs */
881 		total_len = 0xffff;
882 		payload[0].last_byte = ~0;
883 		payload[0].next_hole = 0;
884 		payload[0].prev_hole = 0;
885 		first_hole = 0;
886 		/* any IP header will work, copy the first we received */
887 		memcpy(localip, ip, IP_HDR_SIZE);
888 	}
889 
890 	/*
891 	 * What follows is the reassembly algorithm. We use the payload
892 	 * array as a linked list of hole descriptors, as each hole starts
893 	 * at a multiple of 8 bytes. However, last byte can be whatever value,
894 	 * so it is represented as byte count, not as 8-byte blocks.
895 	 */
896 
897 	h = payload + first_hole;
898 	while (h->last_byte < start) {
899 		if (!h->next_hole) {
900 			/* no hole that far away */
901 			return NULL;
902 		}
903 		h = payload + h->next_hole;
904 	}
905 
906 	/* last fragment may be 1..7 bytes, the "+7" forces acceptance */
907 	if (offset8 + ((len + 7) / 8) <= h - payload) {
908 		/* no overlap with holes (dup fragment?) */
909 		return NULL;
910 	}
911 
912 	if (!(ip_off & IP_FLAGS_MFRAG)) {
913 		/* no more fragmentss: truncate this (last) hole */
914 		total_len = start + len;
915 		h->last_byte = start + len;
916 	}
917 
918 	/*
919 	 * There is some overlap: fix the hole list. This code doesn't
920 	 * deal with a fragment that overlaps with two different holes
921 	 * (thus being a superset of a previously-received fragment).
922 	 */
923 
924 	if ((h >= thisfrag) && (h->last_byte <= start + len)) {
925 		/* complete overlap with hole: remove hole */
926 		if (!h->prev_hole && !h->next_hole) {
927 			/* last remaining hole */
928 			done = 1;
929 		} else if (!h->prev_hole) {
930 			/* first hole */
931 			first_hole = h->next_hole;
932 			payload[h->next_hole].prev_hole = 0;
933 		} else if (!h->next_hole) {
934 			/* last hole */
935 			payload[h->prev_hole].next_hole = 0;
936 		} else {
937 			/* in the middle of the list */
938 			payload[h->next_hole].prev_hole = h->prev_hole;
939 			payload[h->prev_hole].next_hole = h->next_hole;
940 		}
941 
942 	} else if (h->last_byte <= start + len) {
943 		/* overlaps with final part of the hole: shorten this hole */
944 		h->last_byte = start;
945 
946 	} else if (h >= thisfrag) {
947 		/* overlaps with initial part of the hole: move this hole */
948 		newh = thisfrag + (len / 8);
949 		*newh = *h;
950 		h = newh;
951 		if (h->next_hole)
952 			payload[h->next_hole].prev_hole = (h - payload);
953 		if (h->prev_hole)
954 			payload[h->prev_hole].next_hole = (h - payload);
955 		else
956 			first_hole = (h - payload);
957 
958 	} else {
959 		/* fragment sits in the middle: split the hole */
960 		newh = thisfrag + (len / 8);
961 		*newh = *h;
962 		h->last_byte = start;
963 		h->next_hole = (newh - payload);
964 		newh->prev_hole = (h - payload);
965 		if (newh->next_hole)
966 			payload[newh->next_hole].prev_hole = (newh - payload);
967 	}
968 
969 	/* finally copy this fragment and possibly return whole packet */
970 	memcpy((uchar *)thisfrag, indata + IP_HDR_SIZE, len);
971 	if (!done)
972 		return NULL;
973 
974 	localip->ip_len = htons(total_len);
975 	*lenp = total_len + IP_HDR_SIZE;
976 	return localip;
977 }
978 
979 static inline struct ip_udp_hdr *net_defragment(struct ip_udp_hdr *ip,
980 	int *lenp)
981 {
982 	u16 ip_off = ntohs(ip->ip_off);
983 	if (!(ip_off & (IP_OFFS | IP_FLAGS_MFRAG)))
984 		return ip; /* not a fragment */
985 	return __net_defragment(ip, lenp);
986 }
987 
988 #else /* !CONFIG_IP_DEFRAG */
989 
990 static inline struct ip_udp_hdr *net_defragment(struct ip_udp_hdr *ip,
991 	int *lenp)
992 {
993 	u16 ip_off = ntohs(ip->ip_off);
994 	if (!(ip_off & (IP_OFFS | IP_FLAGS_MFRAG)))
995 		return ip; /* not a fragment */
996 	return NULL;
997 }
998 #endif
999 
1000 /**
1001  * Receive an ICMP packet. We deal with REDIRECT and PING here, and silently
1002  * drop others.
1003  *
1004  * @parma ip	IP packet containing the ICMP
1005  */
1006 static void receive_icmp(struct ip_udp_hdr *ip, int len,
1007 			struct in_addr src_ip, struct ethernet_hdr *et)
1008 {
1009 	struct icmp_hdr *icmph = (struct icmp_hdr *)&ip->udp_src;
1010 
1011 	switch (icmph->type) {
1012 	case ICMP_REDIRECT:
1013 		if (icmph->code != ICMP_REDIR_HOST)
1014 			return;
1015 		printf(" ICMP Host Redirect to %pI4 ",
1016 		       &icmph->un.gateway);
1017 		break;
1018 	default:
1019 #if defined(CONFIG_CMD_PING)
1020 		ping_receive(et, ip, len);
1021 #endif
1022 #ifdef CONFIG_CMD_TFTPPUT
1023 		if (packet_icmp_handler)
1024 			packet_icmp_handler(icmph->type, icmph->code,
1025 					    ntohs(ip->udp_dst), src_ip,
1026 					    ntohs(ip->udp_src), icmph->un.data,
1027 					    ntohs(ip->udp_len));
1028 #endif
1029 		break;
1030 	}
1031 }
1032 
1033 void net_process_received_packet(uchar *in_packet, int len)
1034 {
1035 	struct ethernet_hdr *et;
1036 	struct ip_udp_hdr *ip;
1037 	struct in_addr dst_ip;
1038 	struct in_addr src_ip;
1039 	int eth_proto;
1040 #if defined(CONFIG_CMD_CDP)
1041 	int iscdp;
1042 #endif
1043 	ushort cti = 0, vlanid = VLAN_NONE, myvlanid, mynvlanid;
1044 
1045 	debug_cond(DEBUG_NET_PKT, "packet received\n");
1046 
1047 	net_rx_packet = in_packet;
1048 	net_rx_packet_len = len;
1049 	et = (struct ethernet_hdr *)in_packet;
1050 
1051 	/* too small packet? */
1052 	if (len < ETHER_HDR_SIZE)
1053 		return;
1054 
1055 #ifdef CONFIG_API
1056 	if (push_packet) {
1057 		(*push_packet)(in_packet, len);
1058 		return;
1059 	}
1060 #endif
1061 
1062 #if defined(CONFIG_CMD_CDP)
1063 	/* keep track if packet is CDP */
1064 	iscdp = is_cdp_packet(et->et_dest);
1065 #endif
1066 
1067 	myvlanid = ntohs(net_our_vlan);
1068 	if (myvlanid == (ushort)-1)
1069 		myvlanid = VLAN_NONE;
1070 	mynvlanid = ntohs(net_native_vlan);
1071 	if (mynvlanid == (ushort)-1)
1072 		mynvlanid = VLAN_NONE;
1073 
1074 	eth_proto = ntohs(et->et_protlen);
1075 
1076 	if (eth_proto < 1514) {
1077 		struct e802_hdr *et802 = (struct e802_hdr *)et;
1078 		/*
1079 		 *	Got a 802.2 packet.  Check the other protocol field.
1080 		 *	XXX VLAN over 802.2+SNAP not implemented!
1081 		 */
1082 		eth_proto = ntohs(et802->et_prot);
1083 
1084 		ip = (struct ip_udp_hdr *)(in_packet + E802_HDR_SIZE);
1085 		len -= E802_HDR_SIZE;
1086 
1087 	} else if (eth_proto != PROT_VLAN) {	/* normal packet */
1088 		ip = (struct ip_udp_hdr *)(in_packet + ETHER_HDR_SIZE);
1089 		len -= ETHER_HDR_SIZE;
1090 
1091 	} else {			/* VLAN packet */
1092 		struct vlan_ethernet_hdr *vet =
1093 			(struct vlan_ethernet_hdr *)et;
1094 
1095 		debug_cond(DEBUG_NET_PKT, "VLAN packet received\n");
1096 
1097 		/* too small packet? */
1098 		if (len < VLAN_ETHER_HDR_SIZE)
1099 			return;
1100 
1101 		/* if no VLAN active */
1102 		if ((ntohs(net_our_vlan) & VLAN_IDMASK) == VLAN_NONE
1103 #if defined(CONFIG_CMD_CDP)
1104 				&& iscdp == 0
1105 #endif
1106 				)
1107 			return;
1108 
1109 		cti = ntohs(vet->vet_tag);
1110 		vlanid = cti & VLAN_IDMASK;
1111 		eth_proto = ntohs(vet->vet_type);
1112 
1113 		ip = (struct ip_udp_hdr *)(in_packet + VLAN_ETHER_HDR_SIZE);
1114 		len -= VLAN_ETHER_HDR_SIZE;
1115 	}
1116 
1117 	debug_cond(DEBUG_NET_PKT, "Receive from protocol 0x%x\n", eth_proto);
1118 
1119 #if defined(CONFIG_CMD_CDP)
1120 	if (iscdp) {
1121 		cdp_receive((uchar *)ip, len);
1122 		return;
1123 	}
1124 #endif
1125 
1126 	if ((myvlanid & VLAN_IDMASK) != VLAN_NONE) {
1127 		if (vlanid == VLAN_NONE)
1128 			vlanid = (mynvlanid & VLAN_IDMASK);
1129 		/* not matched? */
1130 		if (vlanid != (myvlanid & VLAN_IDMASK))
1131 			return;
1132 	}
1133 
1134 	switch (eth_proto) {
1135 	case PROT_ARP:
1136 		arp_receive(et, ip, len);
1137 		break;
1138 
1139 #ifdef CONFIG_CMD_RARP
1140 	case PROT_RARP:
1141 		rarp_receive(ip, len);
1142 		break;
1143 #endif
1144 	case PROT_IP:
1145 		debug_cond(DEBUG_NET_PKT, "Got IP\n");
1146 		/* Before we start poking the header, make sure it is there */
1147 		if (len < IP_UDP_HDR_SIZE) {
1148 			debug("len bad %d < %lu\n", len,
1149 			      (ulong)IP_UDP_HDR_SIZE);
1150 			return;
1151 		}
1152 		/* Check the packet length */
1153 		if (len < ntohs(ip->ip_len)) {
1154 			debug("len bad %d < %d\n", len, ntohs(ip->ip_len));
1155 			return;
1156 		}
1157 		len = ntohs(ip->ip_len);
1158 		debug_cond(DEBUG_NET_PKT, "len=%d, v=%02x\n",
1159 			   len, ip->ip_hl_v & 0xff);
1160 
1161 		/* Can't deal with anything except IPv4 */
1162 		if ((ip->ip_hl_v & 0xf0) != 0x40)
1163 			return;
1164 		/* Can't deal with IP options (headers != 20 bytes) */
1165 		if ((ip->ip_hl_v & 0x0f) > 0x05)
1166 			return;
1167 		/* Check the Checksum of the header */
1168 		if (!ip_checksum_ok((uchar *)ip, IP_HDR_SIZE)) {
1169 			debug("checksum bad\n");
1170 			return;
1171 		}
1172 		/* If it is not for us, ignore it */
1173 		dst_ip = net_read_ip(&ip->ip_dst);
1174 		if (net_ip.s_addr && dst_ip.s_addr != net_ip.s_addr &&
1175 		    dst_ip.s_addr != 0xFFFFFFFF) {
1176 #ifdef CONFIG_MCAST_TFTP
1177 			if (net_mcast_addr != dst_ip)
1178 #endif
1179 				return;
1180 		}
1181 		/* Read source IP address for later use */
1182 		src_ip = net_read_ip(&ip->ip_src);
1183 		/*
1184 		 * The function returns the unchanged packet if it's not
1185 		 * a fragment, and either the complete packet or NULL if
1186 		 * it is a fragment (if !CONFIG_IP_DEFRAG, it returns NULL)
1187 		 */
1188 		ip = net_defragment(ip, &len);
1189 		if (!ip)
1190 			return;
1191 		/*
1192 		 * watch for ICMP host redirects
1193 		 *
1194 		 * There is no real handler code (yet). We just watch
1195 		 * for ICMP host redirect messages. In case anybody
1196 		 * sees these messages: please contact me
1197 		 * (wd@denx.de), or - even better - send me the
1198 		 * necessary fixes :-)
1199 		 *
1200 		 * Note: in all cases where I have seen this so far
1201 		 * it was a problem with the router configuration,
1202 		 * for instance when a router was configured in the
1203 		 * BOOTP reply, but the TFTP server was on the same
1204 		 * subnet. So this is probably a warning that your
1205 		 * configuration might be wrong. But I'm not really
1206 		 * sure if there aren't any other situations.
1207 		 *
1208 		 * Simon Glass <sjg@chromium.org>: We get an ICMP when
1209 		 * we send a tftp packet to a dead connection, or when
1210 		 * there is no server at the other end.
1211 		 */
1212 		if (ip->ip_p == IPPROTO_ICMP) {
1213 			receive_icmp(ip, len, src_ip, et);
1214 			return;
1215 		} else if (ip->ip_p != IPPROTO_UDP) {	/* Only UDP packets */
1216 			return;
1217 		}
1218 
1219 		debug_cond(DEBUG_DEV_PKT,
1220 			   "received UDP (to=%pI4, from=%pI4, len=%d)\n",
1221 			   &dst_ip, &src_ip, len);
1222 
1223 #ifdef CONFIG_UDP_CHECKSUM
1224 		if (ip->udp_xsum != 0) {
1225 			ulong   xsum;
1226 			ushort *sumptr;
1227 			ushort  sumlen;
1228 
1229 			xsum  = ip->ip_p;
1230 			xsum += (ntohs(ip->udp_len));
1231 			xsum += (ntohl(ip->ip_src.s_addr) >> 16) & 0x0000ffff;
1232 			xsum += (ntohl(ip->ip_src.s_addr) >>  0) & 0x0000ffff;
1233 			xsum += (ntohl(ip->ip_dst.s_addr) >> 16) & 0x0000ffff;
1234 			xsum += (ntohl(ip->ip_dst.s_addr) >>  0) & 0x0000ffff;
1235 
1236 			sumlen = ntohs(ip->udp_len);
1237 			sumptr = (ushort *)&(ip->udp_src);
1238 
1239 			while (sumlen > 1) {
1240 				ushort sumdata;
1241 
1242 				sumdata = *sumptr++;
1243 				xsum += ntohs(sumdata);
1244 				sumlen -= 2;
1245 			}
1246 			if (sumlen > 0) {
1247 				ushort sumdata;
1248 
1249 				sumdata = *(unsigned char *)sumptr;
1250 				sumdata = (sumdata << 8) & 0xff00;
1251 				xsum += sumdata;
1252 			}
1253 			while ((xsum >> 16) != 0) {
1254 				xsum = (xsum & 0x0000ffff) +
1255 				       ((xsum >> 16) & 0x0000ffff);
1256 			}
1257 			if ((xsum != 0x00000000) && (xsum != 0x0000ffff)) {
1258 				printf(" UDP wrong checksum %08lx %08x\n",
1259 				       xsum, ntohs(ip->udp_xsum));
1260 				return;
1261 			}
1262 		}
1263 #endif
1264 
1265 #if defined(CONFIG_NETCONSOLE) && !(CONFIG_SPL_BUILD)
1266 		nc_input_packet((uchar *)ip + IP_UDP_HDR_SIZE,
1267 				src_ip,
1268 				ntohs(ip->udp_dst),
1269 				ntohs(ip->udp_src),
1270 				ntohs(ip->udp_len) - UDP_HDR_SIZE);
1271 #endif
1272 		/*
1273 		 * IP header OK.  Pass the packet to the current handler.
1274 		 */
1275 		(*udp_packet_handler)((uchar *)ip + IP_UDP_HDR_SIZE,
1276 				      ntohs(ip->udp_dst),
1277 				      src_ip,
1278 				      ntohs(ip->udp_src),
1279 				      ntohs(ip->udp_len) - UDP_HDR_SIZE);
1280 		break;
1281 	}
1282 }
1283 
1284 /**********************************************************************/
1285 
1286 static int net_check_prereq(enum proto_t protocol)
1287 {
1288 	switch (protocol) {
1289 		/* Fall through */
1290 #if defined(CONFIG_CMD_PING)
1291 	case PING:
1292 		if (net_ping_ip.s_addr == 0) {
1293 			puts("*** ERROR: ping address not given\n");
1294 			return 1;
1295 		}
1296 		goto common;
1297 #endif
1298 #if defined(CONFIG_CMD_SNTP)
1299 	case SNTP:
1300 		if (net_ntp_server.s_addr == 0) {
1301 			puts("*** ERROR: NTP server address not given\n");
1302 			return 1;
1303 		}
1304 		goto common;
1305 #endif
1306 #if defined(CONFIG_CMD_DNS)
1307 	case DNS:
1308 		if (net_dns_server.s_addr == 0) {
1309 			puts("*** ERROR: DNS server address not given\n");
1310 			return 1;
1311 		}
1312 		goto common;
1313 #endif
1314 #if defined(CONFIG_CMD_NFS)
1315 	case NFS:
1316 #endif
1317 		/* Fall through */
1318 	case TFTPGET:
1319 	case TFTPPUT:
1320 		if (net_server_ip.s_addr == 0) {
1321 			puts("*** ERROR: `serverip' not set\n");
1322 			return 1;
1323 		}
1324 #if	defined(CONFIG_CMD_PING) || defined(CONFIG_CMD_SNTP) || \
1325 	defined(CONFIG_CMD_DNS)
1326 common:
1327 #endif
1328 		/* Fall through */
1329 
1330 	case NETCONS:
1331 	case TFTPSRV:
1332 		if (net_ip.s_addr == 0) {
1333 			puts("*** ERROR: `ipaddr' not set\n");
1334 			return 1;
1335 		}
1336 		/* Fall through */
1337 
1338 #ifdef CONFIG_CMD_RARP
1339 	case RARP:
1340 #endif
1341 	case BOOTP:
1342 	case CDP:
1343 	case DHCP:
1344 	case LINKLOCAL:
1345 		if (memcmp(net_ethaddr, "\0\0\0\0\0\0", 6) == 0) {
1346 			int num = eth_get_dev_index();
1347 
1348 			switch (num) {
1349 			case -1:
1350 				puts("*** ERROR: No ethernet found.\n");
1351 				return 1;
1352 			case 0:
1353 				puts("*** ERROR: `ethaddr' not set\n");
1354 				break;
1355 			default:
1356 				printf("*** ERROR: `eth%daddr' not set\n",
1357 				       num);
1358 				break;
1359 			}
1360 
1361 			net_start_again();
1362 			return 2;
1363 		}
1364 		/* Fall through */
1365 	default:
1366 		return 0;
1367 	}
1368 	return 0;		/* OK */
1369 }
1370 /**********************************************************************/
1371 
1372 int
1373 net_eth_hdr_size(void)
1374 {
1375 	ushort myvlanid;
1376 
1377 	myvlanid = ntohs(net_our_vlan);
1378 	if (myvlanid == (ushort)-1)
1379 		myvlanid = VLAN_NONE;
1380 
1381 	return ((myvlanid & VLAN_IDMASK) == VLAN_NONE) ? ETHER_HDR_SIZE :
1382 		VLAN_ETHER_HDR_SIZE;
1383 }
1384 
1385 int net_set_ether(uchar *xet, const uchar *dest_ethaddr, uint prot)
1386 {
1387 	struct ethernet_hdr *et = (struct ethernet_hdr *)xet;
1388 	ushort myvlanid;
1389 
1390 	myvlanid = ntohs(net_our_vlan);
1391 	if (myvlanid == (ushort)-1)
1392 		myvlanid = VLAN_NONE;
1393 
1394 	memcpy(et->et_dest, dest_ethaddr, 6);
1395 	memcpy(et->et_src, net_ethaddr, 6);
1396 	if ((myvlanid & VLAN_IDMASK) == VLAN_NONE) {
1397 		et->et_protlen = htons(prot);
1398 		return ETHER_HDR_SIZE;
1399 	} else {
1400 		struct vlan_ethernet_hdr *vet =
1401 			(struct vlan_ethernet_hdr *)xet;
1402 
1403 		vet->vet_vlan_type = htons(PROT_VLAN);
1404 		vet->vet_tag = htons((0 << 5) | (myvlanid & VLAN_IDMASK));
1405 		vet->vet_type = htons(prot);
1406 		return VLAN_ETHER_HDR_SIZE;
1407 	}
1408 }
1409 
1410 int net_update_ether(struct ethernet_hdr *et, uchar *addr, uint prot)
1411 {
1412 	ushort protlen;
1413 
1414 	memcpy(et->et_dest, addr, 6);
1415 	memcpy(et->et_src, net_ethaddr, 6);
1416 	protlen = ntohs(et->et_protlen);
1417 	if (protlen == PROT_VLAN) {
1418 		struct vlan_ethernet_hdr *vet =
1419 			(struct vlan_ethernet_hdr *)et;
1420 		vet->vet_type = htons(prot);
1421 		return VLAN_ETHER_HDR_SIZE;
1422 	} else if (protlen > 1514) {
1423 		et->et_protlen = htons(prot);
1424 		return ETHER_HDR_SIZE;
1425 	} else {
1426 		/* 802.2 + SNAP */
1427 		struct e802_hdr *et802 = (struct e802_hdr *)et;
1428 		et802->et_prot = htons(prot);
1429 		return E802_HDR_SIZE;
1430 	}
1431 }
1432 
1433 void net_set_ip_header(uchar *pkt, struct in_addr dest, struct in_addr source)
1434 {
1435 	struct ip_udp_hdr *ip = (struct ip_udp_hdr *)pkt;
1436 
1437 	/*
1438 	 *	Construct an IP header.
1439 	 */
1440 	/* IP_HDR_SIZE / 4 (not including UDP) */
1441 	ip->ip_hl_v  = 0x45;
1442 	ip->ip_tos   = 0;
1443 	ip->ip_len   = htons(IP_HDR_SIZE);
1444 	ip->ip_id    = htons(net_ip_id++);
1445 	ip->ip_off   = htons(IP_FLAGS_DFRAG);	/* Don't fragment */
1446 	ip->ip_ttl   = 255;
1447 	ip->ip_sum   = 0;
1448 	/* already in network byte order */
1449 	net_copy_ip((void *)&ip->ip_src, &source);
1450 	/* already in network byte order */
1451 	net_copy_ip((void *)&ip->ip_dst, &dest);
1452 }
1453 
1454 void net_set_udp_header(uchar *pkt, struct in_addr dest, int dport, int sport,
1455 			int len)
1456 {
1457 	struct ip_udp_hdr *ip = (struct ip_udp_hdr *)pkt;
1458 
1459 	/*
1460 	 *	If the data is an odd number of bytes, zero the
1461 	 *	byte after the last byte so that the checksum
1462 	 *	will work.
1463 	 */
1464 	if (len & 1)
1465 		pkt[IP_UDP_HDR_SIZE + len] = 0;
1466 
1467 	net_set_ip_header(pkt, dest, net_ip);
1468 	ip->ip_len   = htons(IP_UDP_HDR_SIZE + len);
1469 	ip->ip_p     = IPPROTO_UDP;
1470 	ip->ip_sum   = compute_ip_checksum(ip, IP_HDR_SIZE);
1471 
1472 	ip->udp_src  = htons(sport);
1473 	ip->udp_dst  = htons(dport);
1474 	ip->udp_len  = htons(UDP_HDR_SIZE + len);
1475 	ip->udp_xsum = 0;
1476 }
1477 
1478 void copy_filename(char *dst, const char *src, int size)
1479 {
1480 	if (*src && (*src == '"')) {
1481 		++src;
1482 		--size;
1483 	}
1484 
1485 	while ((--size > 0) && *src && (*src != '"'))
1486 		*dst++ = *src++;
1487 	*dst = '\0';
1488 }
1489 
1490 #if	defined(CONFIG_CMD_NFS)		|| \
1491 	defined(CONFIG_CMD_SNTP)	|| \
1492 	defined(CONFIG_CMD_DNS)
1493 /*
1494  * make port a little random (1024-17407)
1495  * This keeps the math somewhat trivial to compute, and seems to work with
1496  * all supported protocols/clients/servers
1497  */
1498 unsigned int random_port(void)
1499 {
1500 	return 1024 + (get_timer(0) % 0x4000);
1501 }
1502 #endif
1503 
1504 void ip_to_string(struct in_addr x, char *s)
1505 {
1506 	x.s_addr = ntohl(x.s_addr);
1507 	sprintf(s, "%d.%d.%d.%d",
1508 		(int) ((x.s_addr >> 24) & 0xff),
1509 		(int) ((x.s_addr >> 16) & 0xff),
1510 		(int) ((x.s_addr >> 8) & 0xff),
1511 		(int) ((x.s_addr >> 0) & 0xff)
1512 	);
1513 }
1514 
1515 void vlan_to_string(ushort x, char *s)
1516 {
1517 	x = ntohs(x);
1518 
1519 	if (x == (ushort)-1)
1520 		x = VLAN_NONE;
1521 
1522 	if (x == VLAN_NONE)
1523 		strcpy(s, "none");
1524 	else
1525 		sprintf(s, "%d", x & VLAN_IDMASK);
1526 }
1527 
1528 ushort string_to_vlan(const char *s)
1529 {
1530 	ushort id;
1531 
1532 	if (s == NULL)
1533 		return htons(VLAN_NONE);
1534 
1535 	if (*s < '0' || *s > '9')
1536 		id = VLAN_NONE;
1537 	else
1538 		id = (ushort)simple_strtoul(s, NULL, 10);
1539 
1540 	return htons(id);
1541 }
1542 
1543 ushort getenv_vlan(char *var)
1544 {
1545 	return string_to_vlan(getenv(var));
1546 }
1547