xref: /openbmc/u-boot/net/net.c (revision 180d3f74)
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  */
10 
11 /*
12  * General Desription:
13  *
14  * The user interface supports commands for BOOTP, RARP, and TFTP.
15  * Also, we support ARP internally. Depending on available data,
16  * these interact as follows:
17  *
18  * BOOTP:
19  *
20  *	Prerequisites:	- own ethernet address
21  *	We want:	- own IP address
22  *			- TFTP server IP address
23  *			- name of bootfile
24  *	Next step:	ARP
25  *
26  * RARP:
27  *
28  *	Prerequisites:	- own ethernet address
29  *	We want:	- own IP address
30  *			- TFTP server IP address
31  *	Next step:	ARP
32  *
33  * ARP:
34  *
35  *	Prerequisites:	- own ethernet address
36  *			- own IP address
37  *			- TFTP server IP address
38  *	We want:	- TFTP server ethernet address
39  *	Next step:	TFTP
40  *
41  * DHCP:
42  *
43  *     Prerequisites:   - own ethernet address
44  *     We want:         - IP, Netmask, ServerIP, Gateway IP
45  *                      - bootfilename, lease time
46  *     Next step:       - TFTP
47  *
48  * TFTP:
49  *
50  *	Prerequisites:	- own ethernet address
51  *			- own IP address
52  *			- TFTP server IP address
53  *			- TFTP server ethernet address
54  *			- name of bootfile (if unknown, we use a default name
55  *			  derived from our own IP address)
56  *	We want:	- load the boot file
57  *	Next step:	none
58  */
59 
60 
61 #include <common.h>
62 #include <watchdog.h>
63 #include <command.h>
64 #include <net.h>
65 #include "bootp.h"
66 #include "tftp.h"
67 #include "rarp.h"
68 #ifdef CONFIG_STATUS_LED
69 #include <status_led.h>
70 #include <miiphy.h>
71 #endif
72 
73 #if (CONFIG_COMMANDS & CFG_CMD_NET)
74 
75 #define ARP_TIMEOUT		5		/* Seconds before trying ARP again */
76 #ifndef	CONFIG_NET_RETRY_COUNT
77 # define ARP_TIMEOUT_COUNT	5		/* # of timeouts before giving up  */
78 #else
79 # define ARP_TIMEOUT_COUNT  (CONFIG_NET_RETRY_COUNT)
80 #endif
81 
82 #if 0
83 #define ET_DEBUG
84 #endif
85 
86 /** BOOTP EXTENTIONS **/
87 
88 IPaddr_t	NetOurSubnetMask=0;		/* Our subnet mask (0=unknown)	*/
89 IPaddr_t	NetOurGatewayIP=0;		/* Our gateways IP address	*/
90 IPaddr_t	NetOurDNSIP=0;			/* Our DNS IP address		*/
91 #if (CONFIG_BOOTP_MASK & CONFIG_BOOTP_DNS2)
92 IPaddr_t	NetOurDNS2IP=0;			/* Our 2nd DNS IP address	*/
93 #endif
94 char		NetOurNISDomain[32]={0,};	/* Our NIS domain		*/
95 char		NetOurHostName[32]={0,};	/* Our hostname			*/
96 char		NetOurRootPath[64]={0,};	/* Our bootpath			*/
97 ushort		NetBootFileSize=0;		/* Our bootfile size in blocks	*/
98 
99 /** END OF BOOTP EXTENTIONS **/
100 
101 ulong		NetBootFileXferSize;	/* The actual transferred size of the bootfile (in bytes) */
102 uchar		NetOurEther[6];		/* Our ethernet address			*/
103 uchar		NetServerEther[6] =	/* Boot server enet address		*/
104 			{ 0, 0, 0, 0, 0, 0 };
105 IPaddr_t	NetOurIP;		/* Our IP addr (0 = unknown)		*/
106 IPaddr_t	NetServerIP;		/* Our IP addr (0 = unknown)		*/
107 volatile uchar *NetRxPkt;		/* Current receive packet		*/
108 int		NetRxPktLen;		/* Current rx packet length		*/
109 unsigned	NetIPID;		/* IP packet ID				*/
110 uchar		NetBcastAddr[6] =	/* Ethernet bcast address		*/
111 			{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
112 uchar		NetEtherNullAddr[6] =
113 			{ 0, 0, 0, 0, 0, 0 };
114 int		NetState;		/* Network loop state			*/
115 #ifdef CONFIG_NET_MULTI
116 int		NetRestartWrap = 0;	/* Tried all network devices		*/
117 static int	NetRestarted = 0;	/* Network loop restarted		*/
118 static int	NetDevExists = 0;	/* At least one device configured	*/
119 #endif
120 
121 char		BootFile[128];		/* Boot File name			*/
122 
123 #if (CONFIG_COMMANDS & CFG_CMD_PING)
124 IPaddr_t	NetPingIP;		/* the ip address to ping 		*/
125 
126 static void PingStart(void);
127 #endif
128 
129 volatile uchar	PktBuf[(PKTBUFSRX+1) * PKTSIZE_ALIGN + PKTALIGN];
130 
131 volatile uchar *NetRxPackets[PKTBUFSRX]; /* Receive packets			*/
132 
133 static rxhand_f *packetHandler;		/* Current RX packet handler		*/
134 static thand_f *timeHandler;		/* Current timeout handler		*/
135 static ulong	timeStart;		/* Time base value			*/
136 static ulong	timeDelta;		/* Current timeout value		*/
137 volatile uchar *NetTxPacket = 0;	/* THE transmit packet			*/
138 
139 static int net_check_prereq (proto_t protocol);
140 
141 /**********************************************************************/
142 
143 IPaddr_t	NetArpWaitPacketIP;
144 IPaddr_t	NetArpWaitReplyIP;
145 uchar	       *NetArpWaitPacketMAC;	/* MAC address of waiting packet's destination	*/
146 uchar          *NetArpWaitTxPacket;	/* THE transmit packet			*/
147 int		NetArpWaitTxPacketSize;
148 uchar 		NetArpWaitPacketBuf[PKTSIZE_ALIGN + PKTALIGN];
149 ulong		NetArpWaitTimerStart;
150 int		NetArpWaitTry;
151 
152 void ArpRequest(void)
153 {
154 	int i;
155 	volatile uchar *pkt;
156 	ARP_t *	arp;
157 
158 #ifdef ET_DEBUG
159 	printf("ARP broadcast %d\n", NetArpWaitTry);
160 #endif
161 	pkt = NetTxPacket;
162 
163 	NetSetEther(pkt, NetBcastAddr, PROT_ARP);
164 	pkt += ETHER_HDR_SIZE;
165 
166 	arp = (ARP_t *)pkt;
167 
168 	arp->ar_hrd = htons(ARP_ETHER);
169 	arp->ar_pro = htons(PROT_IP);
170 	arp->ar_hln = 6;
171 	arp->ar_pln = 4;
172 	arp->ar_op  = htons(ARPOP_REQUEST);
173 
174 	memcpy (&arp->ar_data[0], NetOurEther, 6);	/* source ET addr	*/
175 	NetWriteIP((uchar*)&arp->ar_data[6], NetOurIP);	/* source IP addr	*/
176 	for (i=10; i<16; ++i) {
177 		arp->ar_data[i] = 0;			/* dest ET addr = 0	*/
178 	}
179 
180 	if((NetArpWaitPacketIP & NetOurSubnetMask) != (NetOurIP & NetOurSubnetMask)) {
181 	    if (NetOurGatewayIP == 0) {
182 		puts ("## Warning: gatewayip needed but not set\n");
183 	    }
184 	    NetArpWaitReplyIP = NetOurGatewayIP;
185 	} else
186 	    NetArpWaitReplyIP = NetArpWaitPacketIP;
187 
188 	NetWriteIP((uchar*)&arp->ar_data[16], NetArpWaitReplyIP);
189 	(void) eth_send(NetTxPacket, ETHER_HDR_SIZE + ARP_HDR_SIZE);
190 }
191 
192 void ArpTimeoutCheck(void)
193 {
194 	ulong t;
195 
196 	if (!NetArpWaitPacketIP)
197 		return;
198 
199 	t = get_timer(0);
200 
201 	/* check for arp timeout */
202 	if ((t - NetArpWaitTimerStart) > ARP_TIMEOUT * CFG_HZ) {
203 		NetArpWaitTry++;
204 
205 		if (NetArpWaitTry >= ARP_TIMEOUT_COUNT) {
206 			puts ("\nARP Retry count exceeded; starting again\n");
207 			NetArpWaitTry = 0;
208 			NetStartAgain();
209 		} else {
210 			NetArpWaitTimerStart = t;
211 			ArpRequest();
212 		}
213 	}
214 }
215 
216 /**********************************************************************/
217 /*
218  *	Main network processing loop.
219  */
220 
221 int
222 NetLoop(proto_t protocol)
223 {
224 	DECLARE_GLOBAL_DATA_PTR;
225 
226 	bd_t *bd = gd->bd;
227 
228 #ifdef CONFIG_NET_MULTI
229 	NetRestarted = 0;
230 	NetDevExists = 0;
231 #endif
232 
233 	/* XXX problem with bss workaround */
234 	NetArpWaitPacketMAC = NULL;
235 	NetArpWaitTxPacket = NULL;
236 	NetArpWaitPacketIP = 0;
237 	NetArpWaitReplyIP = 0;
238 	NetArpWaitTxPacket = NULL;
239 	NetTxPacket = NULL;
240 
241 	if (!NetTxPacket) {
242 		int	i;
243 
244 		/*
245 		 *	Setup packet buffers, aligned correctly.
246 		 */
247 		NetTxPacket = &PktBuf[0] + (PKTALIGN - 1);
248 		NetTxPacket -= (ulong)NetTxPacket % PKTALIGN;
249 		for (i = 0; i < PKTBUFSRX; i++) {
250 			NetRxPackets[i] = NetTxPacket + (i+1)*PKTSIZE_ALIGN;
251 		}
252 
253 	}
254 
255 	if (!NetArpWaitTxPacket) {
256 		NetArpWaitTxPacket = &NetArpWaitPacketBuf[0] + (PKTALIGN - 1);
257 		NetArpWaitTxPacket -= (ulong)NetArpWaitTxPacket % PKTALIGN;
258 		NetArpWaitTxPacketSize = 0;
259 	}
260 
261 	eth_halt();
262 	if(eth_init(bd) < 0)
263 	    return(-1);
264 
265 restart:
266 #ifdef CONFIG_NET_MULTI
267 	memcpy (NetOurEther, eth_get_dev()->enetaddr, 6);
268 #else
269 	memcpy (NetOurEther, bd->bi_enetaddr, 6);
270 #endif
271 
272 	NetState = NETLOOP_CONTINUE;
273 
274 	/*
275 	 *	Start the ball rolling with the given start function.  From
276 	 *	here on, this code is a state machine driven by received
277 	 *	packets and timer events.
278 	 */
279 
280 	switch (protocol) {
281 #if (CONFIG_COMMANDS & CFG_CMD_PING)
282 	case PING:
283 #endif
284 	case TFTP:
285 		NetCopyIP(&NetOurIP, &bd->bi_ip_addr);
286 		NetOurGatewayIP = getenv_IPaddr ("gatewayip");
287 		NetOurSubnetMask= getenv_IPaddr ("netmask");
288 
289 		switch (protocol) {
290 		case TFTP:
291 			NetServerIP = getenv_IPaddr ("serverip");
292 			break;
293 #if (CONFIG_COMMANDS & CFG_CMD_PING)
294 		case PING:
295 			/* nothing */
296 			break;
297 #endif
298 		default:
299 			break;
300 		}
301 
302 		break;
303 	case BOOTP:
304 	case RARP:
305 		/*
306 		 * initialize our IP addr to 0 in order to accept ANY
307 		 * IP addr assigned to us by the BOOTP / RARP server
308 		 */
309 		NetOurIP = 0;
310 		NetServerIP = 0;
311 		break;
312 	default:
313 		break;
314 	}
315 
316 	switch (net_check_prereq (protocol)) {
317 	case 1:
318 		/* network not configured */
319 		return (-1);
320 
321 #ifdef CONFIG_NET_MULTI
322 	case 2:
323 		/* network device not configured */
324 		break;
325 #endif /* CONFIG_NET_MULTI */
326 
327 	case 0:
328 #ifdef CONFIG_NET_MULTI
329 		NetDevExists = 1;
330 #endif
331 		switch (protocol) {
332 		case TFTP:
333 			/* always use ARP to get server ethernet address */
334 			TftpStart();
335 			break;
336 
337 #if (CONFIG_COMMANDS & CFG_CMD_DHCP)
338 		case DHCP:
339 			/* Start with a clean slate... */
340 			NetOurIP = 0;
341 			NetServerIP = 0;
342 			DhcpRequest();		/* Basically same as BOOTP */
343 			break;
344 #endif /* CFG_CMD_DHCP */
345 
346 		case BOOTP:
347 			BootpTry = 0;
348 			BootpRequest ();
349 			break;
350 
351 		case RARP:
352 			RarpTry = 0;
353 			RarpRequest ();
354 			break;
355 #if (CONFIG_COMMANDS & CFG_CMD_PING)
356 		case PING:
357 			PingStart();
358 			break;
359 #endif
360 		default:
361 			break;
362 		}
363 
364 		NetBootFileXferSize = 0;
365 		break;
366 	}
367 
368 #if defined(CONFIG_MII) || (CONFIG_COMMANDS & CFG_CMD_MII)
369 #if defined(CFG_FAULT_ECHO_LINK_DOWN) && defined(CONFIG_STATUS_LED) && defined(STATUS_LED_RED)
370 	/*
371 	 * Echo the inverted link state to the fault LED.
372 	 */
373 	if(miiphy_link(CFG_FAULT_MII_ADDR)) {
374 		status_led_set (STATUS_LED_RED, STATUS_LED_OFF);
375 	} else {
376 		status_led_set (STATUS_LED_RED, STATUS_LED_ON);
377 	}
378 #endif /* CFG_FAULT_ECHO_LINK_DOWN, ... */
379 #endif /* CONFIG_MII, ... */
380 
381 	/*
382 	 *	Main packet reception loop.  Loop receiving packets until
383 	 *	someone sets `NetQuit'.
384 	 */
385 	for (;;) {
386 		WATCHDOG_RESET();
387 #ifdef CONFIG_SHOW_ACTIVITY
388 		{
389 			extern void show_activity(int arg);
390 			show_activity(1);
391 		}
392 #endif
393 		/*
394 		 *	Check the ethernet for a new packet.  The ethernet
395 		 *	receive routine will process it.
396 		 */
397 			eth_rx();
398 
399 		/*
400 		 *	Abort if ctrl-c was pressed.
401 		 */
402 		if (ctrlc()) {
403 			eth_halt();
404 			printf("\nAbort\n");
405 			return (-1);
406 		}
407 
408 		ArpTimeoutCheck();
409 
410 		/*
411 		 *	Check for a timeout, and run the timeout handler
412 		 *	if we have one.
413 		 */
414 		if (timeHandler && ((get_timer(0) - timeStart) > timeDelta)) {
415 			thand_f *x;
416 
417 #if defined(CONFIG_MII) || (CONFIG_COMMANDS & CFG_CMD_MII)
418 #if defined(CFG_FAULT_ECHO_LINK_DOWN) && defined(CONFIG_STATUS_LED) && defined(STATUS_LED_RED)
419 			/*
420 			 * Echo the inverted link state to the fault LED.
421 			 */
422 			if(miiphy_link(CFG_FAULT_MII_ADDR)) {
423 				status_led_set (STATUS_LED_RED, STATUS_LED_OFF);
424 			} else {
425 				status_led_set (STATUS_LED_RED, STATUS_LED_ON);
426 			}
427 #endif /* CFG_FAULT_ECHO_LINK_DOWN, ... */
428 #endif /* CONFIG_MII, ... */
429 			x = timeHandler;
430 			timeHandler = (thand_f *)0;
431 			(*x)();
432 		}
433 
434 
435 		switch (NetState) {
436 
437 		case NETLOOP_RESTART:
438 #ifdef CONFIG_NET_MULTI
439 			NetRestarted = 1;
440 #endif
441 			goto restart;
442 
443 		case NETLOOP_SUCCESS:
444 			if (NetBootFileXferSize > 0) {
445 				char buf[10];
446 				printf("Bytes transferred = %ld (%lx hex)\n",
447 					NetBootFileXferSize,
448 					NetBootFileXferSize);
449 				sprintf(buf, "%lx", NetBootFileXferSize);
450 				setenv("filesize", buf);
451 			}
452 			eth_halt();
453 			return NetBootFileXferSize;
454 
455 		case NETLOOP_FAIL:
456 			return (-1);
457 		}
458 	}
459 }
460 
461 /**********************************************************************/
462 
463 static void
464 startAgainTimeout(void)
465 {
466 	NetState = NETLOOP_RESTART;
467 }
468 
469 static void
470 startAgainHandler(uchar * pkt, unsigned dest, unsigned src, unsigned len)
471 {
472 	/* Totally ignore the packet */
473 }
474 
475 void
476 NetStartAgain(void)
477 {
478 #ifndef CONFIG_NET_MULTI
479 	NetSetTimeout(10 * CFG_HZ, startAgainTimeout);
480 	NetSetHandler(startAgainHandler);
481 #else
482 	DECLARE_GLOBAL_DATA_PTR;
483 
484 	eth_halt();
485 	eth_try_another(!NetRestarted);
486 	eth_init(gd->bd);
487 	if (NetRestartWrap)
488 	{
489 		NetRestartWrap = 0;
490 		if (NetDevExists)
491 		{
492 			NetSetTimeout(10 * CFG_HZ, startAgainTimeout);
493 			NetSetHandler(startAgainHandler);
494 		}
495 		else
496 		{
497 			NetState = NETLOOP_FAIL;
498 		}
499 	}
500 	else
501 	{
502 		NetState = NETLOOP_RESTART;
503 	}
504 #endif
505 }
506 
507 /**********************************************************************/
508 /*
509  *	Miscelaneous bits.
510  */
511 
512 void
513 NetSetHandler(rxhand_f * f)
514 {
515 	packetHandler = f;
516 }
517 
518 
519 void
520 NetSetTimeout(int iv, thand_f * f)
521 {
522 	if (iv == 0) {
523 		timeHandler = (thand_f *)0;
524 	} else {
525 		timeHandler = f;
526 		timeStart = get_timer(0);
527 		timeDelta = iv;
528 	}
529 }
530 
531 
532 void
533 NetSendPacket(volatile uchar * pkt, int len)
534 {
535 	(void) eth_send(pkt, len);
536 }
537 
538 int
539 NetSendUDPPacket(uchar *ether, IPaddr_t dest, int dport, int sport, int len)
540 {
541 	/* convert to new style broadcast */
542 	if (dest == 0)
543 		dest = 0xFFFFFFFF;
544 
545 	/* if broadcast, make the ether address a broadcast and don't do ARP */
546 	if (dest == 0xFFFFFFFF)
547 		ether = NetBcastAddr;
548 
549 	/* if MAC address was not discovered yet, save the packet and do an ARP request */
550 	if (memcmp(ether, NetEtherNullAddr, 6) == 0) {
551 
552 #ifdef ET_DEBUG
553 		printf("sending ARP for %08lx\n", dest);
554 #endif
555 
556 		NetArpWaitPacketIP = dest;
557 		NetArpWaitPacketMAC = ether;
558 		NetSetEther (NetArpWaitTxPacket, NetArpWaitPacketMAC, PROT_IP);
559 		NetSetIP (NetArpWaitTxPacket + ETHER_HDR_SIZE, dest, dport, sport, len);
560 		memcpy(NetArpWaitTxPacket + ETHER_HDR_SIZE + IP_HDR_SIZE,
561 			(uchar *)NetTxPacket + ETHER_HDR_SIZE + IP_HDR_SIZE, len);
562 
563 		/* size of the waiting packet */
564 		NetArpWaitTxPacketSize = ETHER_HDR_SIZE + IP_HDR_SIZE + len;
565 
566 		/* and do the ARP request */
567 		NetArpWaitTry = 1;
568 		NetArpWaitTimerStart = get_timer(0);
569 		ArpRequest();
570 		return 1;	/* waiting */
571 	}
572 
573 #ifdef ET_DEBUG
574 	printf("sending UDP to %08lx/%02x:%02x:%02x:%02x:%02x:%02x\n",
575 			dest, ether[0], ether[1], ether[2], ether[3], ether[4], ether[5]);
576 #endif
577 
578 	NetSetEther (NetTxPacket, ether, PROT_IP);
579 	NetSetIP (NetTxPacket + ETHER_HDR_SIZE, dest, dport, sport, len);
580 	(void) eth_send(NetTxPacket, ETHER_HDR_SIZE + IP_HDR_SIZE + len);
581 
582 	return 0;	/* transmited */
583 }
584 
585 #if (CONFIG_COMMANDS & CFG_CMD_PING)
586 static ushort PingSeqNo;
587 
588 int PingSend(void)
589 {
590 	static uchar mac[6];
591 	volatile IP_t *ip;
592 	volatile ushort *s;
593 
594 	/* XXX always send arp request */
595 
596 	memcpy(mac, NetEtherNullAddr, 6);
597 
598 #ifdef ET_DEBUG
599 	printf("sending ARP for %08lx\n", NetPingIP);
600 #endif
601 
602 	NetArpWaitPacketIP = NetPingIP;
603 	NetArpWaitPacketMAC = mac;
604 
605 	NetSetEther(NetArpWaitTxPacket, mac, PROT_IP);
606 
607 	ip = (volatile IP_t *)(NetArpWaitTxPacket + ETHER_HDR_SIZE);
608 
609 	/*
610 	 *	Construct an IP and ICMP header.  (need to set no fragment bit - XXX)
611 	 */
612 	ip->ip_hl_v  = 0x45;		/* IP_HDR_SIZE / 4 (not including UDP) */
613 	ip->ip_tos   = 0;
614 	ip->ip_len   = htons(IP_HDR_SIZE_NO_UDP + 8);
615 	ip->ip_id    = htons(NetIPID++);
616 	ip->ip_off   = htons(0x4000);	/* No fragmentation */
617 	ip->ip_ttl   = 255;
618 	ip->ip_p     = 0x01;		/* ICMP */
619 	ip->ip_sum   = 0;
620 	NetCopyIP((void*)&ip->ip_src, &NetOurIP); /* already in network byte order */
621 	NetCopyIP((void*)&ip->ip_dst, &NetPingIP);	   /* - "" - */
622 	ip->ip_sum   = ~NetCksum((uchar *)ip, IP_HDR_SIZE_NO_UDP / 2);
623 
624 	s = &ip->udp_src;		/* XXX ICMP starts here */
625 	s[0] = htons(0x0800);		/* echo-request, code */
626 	s[1] = 0;			/* checksum */
627 	s[2] = 0; 			/* identifier */
628 	s[3] = htons(PingSeqNo++);	/* sequence number */
629 	s[1] = ~NetCksum((uchar *)s, 8/2);
630 
631 	/* size of the waiting packet */
632 	NetArpWaitTxPacketSize = ETHER_HDR_SIZE + IP_HDR_SIZE_NO_UDP + 8;
633 
634 	/* and do the ARP request */
635 	NetArpWaitTry = 1;
636 	NetArpWaitTimerStart = get_timer(0);
637 	ArpRequest();
638 	return 1;	/* waiting */
639 }
640 
641 static void
642 PingTimeout (void)
643 {
644 	eth_halt();
645 	NetState = NETLOOP_FAIL;	/* we did not get the reply */
646 }
647 
648 static void
649 PingHandler (uchar * pkt, unsigned dest, unsigned src, unsigned len)
650 {
651 	IPaddr_t tmp;
652 	volatile IP_t *ip = (volatile IP_t *)pkt;
653 
654 	tmp = NetReadIP((void *)&ip->ip_src);
655 	if (tmp != NetPingIP)
656 		return;
657 
658 	NetState = NETLOOP_SUCCESS;
659 }
660 
661 static void PingStart(void)
662 {
663 	NetSetTimeout (10 * CFG_HZ, PingTimeout);
664 	NetSetHandler (PingHandler);
665 
666 	PingSend();
667 }
668 
669 #endif
670 
671 void
672 NetReceive(volatile uchar * pkt, int len)
673 {
674 	Ethernet_t *et;
675 	IP_t	*ip;
676 	ARP_t	*arp;
677 	IPaddr_t tmp;
678 	int	x;
679 
680 	NetRxPkt = pkt;
681 	NetRxPktLen = len;
682 	et = (Ethernet_t *)pkt;
683 
684 	x = ntohs(et->et_protlen);
685 
686 	if (x < 1514) {
687 		/*
688 		 *	Got a 802 packet.  Check the other protocol field.
689 		 */
690 		x = ntohs(et->et_prot);
691 		ip = (IP_t *)(pkt + E802_HDR_SIZE);
692 		len -= E802_HDR_SIZE;
693 	} else {
694 		ip = (IP_t *)(pkt + ETHER_HDR_SIZE);
695 		len -= ETHER_HDR_SIZE;
696 	}
697 
698 #ifdef ET_DEBUG
699 	printf("Receive from protocol 0x%x\n", x);
700 #endif
701 
702 	switch (x) {
703 
704 	case PROT_ARP:
705 		/*
706 		 * We have to deal with two types of ARP packets:
707 		 * - REQUEST packets will be answered by sending  our
708 		 *   IP address - if we know it.
709 		 * - REPLY packates are expected only after we asked
710 		 *   for the TFTP server's or the gateway's ethernet
711 		 *   address; so if we receive such a packet, we set
712 		 *   the server ethernet address
713 		 */
714 #ifdef ET_DEBUG
715 		printf("Got ARP\n");
716 #endif
717 		arp = (ARP_t *)ip;
718 		if (len < ARP_HDR_SIZE) {
719 			printf("bad length %d < %d\n", len, ARP_HDR_SIZE);
720 			return;
721 		}
722 		if (ntohs(arp->ar_hrd) != ARP_ETHER) {
723 			return;
724 		}
725 		if (ntohs(arp->ar_pro) != PROT_IP) {
726 			return;
727 		}
728 		if (arp->ar_hln != 6) {
729 			return;
730 		}
731 		if (arp->ar_pln != 4) {
732 			return;
733 		}
734 
735 		if (NetOurIP == 0) {
736 			return;
737 		}
738 
739 		if (NetReadIP(&arp->ar_data[16]) != NetOurIP) {
740 			return;
741 		}
742 
743 		switch (ntohs(arp->ar_op)) {
744 		case ARPOP_REQUEST:		/* reply with our IP address	*/
745 #ifdef ET_DEBUG
746 			printf("Got ARP REQUEST, return our IP\n");
747 #endif
748 			NetSetEther((uchar *)et, et->et_src, PROT_ARP);
749 			arp->ar_op = htons(ARPOP_REPLY);
750 			memcpy   (&arp->ar_data[10], &arp->ar_data[0], 6);
751 			NetCopyIP(&arp->ar_data[16], &arp->ar_data[6]);
752 			memcpy   (&arp->ar_data[ 0], NetOurEther, 6);
753 			NetCopyIP(&arp->ar_data[ 6], &NetOurIP);
754 			(void) eth_send((uchar *)et, ((uchar *)arp-pkt) + ARP_HDR_SIZE);
755 			return;
756 
757 		case ARPOP_REPLY:		/* arp reply */
758 			/* are we waiting for a reply */
759 			if (!NetArpWaitPacketIP || !NetArpWaitPacketMAC)
760 				break;
761 #ifdef ET_DEBUG
762 			printf("Got ARP REPLY, set server/gtwy eth addr (%02x:%02x:%02x:%02x:%02x:%02x)\n",
763 				arp->ar_data[0], arp->ar_data[1],
764 				arp->ar_data[2], arp->ar_data[3],
765 				arp->ar_data[4], arp->ar_data[5]);
766 #endif
767 
768 			tmp = NetReadIP(&arp->ar_data[6]);
769 
770 			/* matched waiting packet's address */
771 			if (tmp == NetArpWaitReplyIP) {
772 #ifdef ET_DEBUG
773 				printf("Got it\n");
774 #endif
775 				/* save address for later use */
776 				memcpy(NetArpWaitPacketMAC, &arp->ar_data[0], 6);
777 
778 				/* modify header, and transmit it */
779 				memcpy(((Ethernet_t *)NetArpWaitTxPacket)->et_dest, NetArpWaitPacketMAC, 6);
780 				(void) eth_send(NetArpWaitTxPacket, NetArpWaitTxPacketSize);
781 
782 				/* no arp request pending now */
783 				NetArpWaitPacketIP = 0;
784 				NetArpWaitTxPacketSize = 0;
785 				NetArpWaitPacketMAC = NULL;
786 
787 			}
788 			return;
789 		default:
790 #ifdef ET_DEBUG
791 			printf("Unexpected ARP opcode 0x%x\n", ntohs(arp->ar_op));
792 #endif
793 			return;
794 		}
795 
796 	case PROT_RARP:
797 #ifdef ET_DEBUG
798 		printf("Got RARP\n");
799 #endif
800 		arp = (ARP_t *)ip;
801 		if (len < ARP_HDR_SIZE) {
802 			printf("bad length %d < %d\n", len, ARP_HDR_SIZE);
803 			return;
804 		}
805 
806 		if ((ntohs(arp->ar_op) != RARPOP_REPLY) ||
807 			(ntohs(arp->ar_hrd) != ARP_ETHER)   ||
808 			(ntohs(arp->ar_pro) != PROT_IP)     ||
809 			(arp->ar_hln != 6) || (arp->ar_pln != 4)) {
810 
811 			printf("invalid RARP header\n");
812 		} else {
813 			NetCopyIP(&NetOurIP,    &arp->ar_data[16]);
814 			NetCopyIP(&NetServerIP, &arp->ar_data[ 6]);
815 			memcpy (NetServerEther, &arp->ar_data[ 0], 6);
816 
817 			(*packetHandler)(0,0,0,0);
818 		}
819 		break;
820 
821 	case PROT_IP:
822 #ifdef ET_DEBUG
823 		printf("Got IP\n");
824 #endif
825 		if (len < IP_HDR_SIZE) {
826 			debug ("len bad %d < %d\n", len, IP_HDR_SIZE);
827 			return;
828 		}
829 		if (len < ntohs(ip->ip_len)) {
830 			printf("len bad %d < %d\n", len, ntohs(ip->ip_len));
831 			return;
832 		}
833 		len = ntohs(ip->ip_len);
834 #ifdef ET_DEBUG
835 		printf("len=%d, v=%02x\n", len, ip->ip_hl_v & 0xff);
836 #endif
837 		if ((ip->ip_hl_v & 0xf0) != 0x40) {
838 			return;
839 		}
840 		if (ip->ip_off & htons(0x1fff)) { /* Can't deal w/ fragments */
841 			return;
842 		}
843 		if (!NetCksumOk((uchar *)ip, IP_HDR_SIZE_NO_UDP / 2)) {
844 			printf("checksum bad\n");
845 			return;
846 		}
847 		tmp = NetReadIP(&ip->ip_dst);
848 		if (NetOurIP && tmp != NetOurIP && tmp != 0xFFFFFFFF) {
849 			return;
850 		}
851 		/*
852 		 * watch for ICMP host redirects
853 		 *
854 		 * There is no real handler code (yet). We just watch
855 		 * for ICMP host redirect messages. In case anybody
856 		 * sees these messages: please contact me
857 		 * (wd@denx.de), or - even better - send me the
858 		 * necessary fixes :-)
859 		 *
860 		 * Note: in all cases where I have seen this so far
861 		 * it was a problem with the router configuration,
862 		 * for instance when a router was configured in the
863 		 * BOOTP reply, but the TFTP server was on the same
864 		 * subnet. So this is probably a warning that your
865 		 * configuration might be wrong. But I'm not really
866 		 * sure if there aren't any other situations.
867 		 */
868 		if (ip->ip_p == IPPROTO_ICMP) {
869 			ICMP_t *icmph = (ICMP_t *)&(ip->udp_src);
870 
871 			switch (icmph->type) {
872 			case ICMP_REDIRECT:
873 			if (icmph->code != ICMP_REDIR_HOST)
874 				return;
875 			puts (" ICMP Host Redirect to ");
876 			print_IPaddr(icmph->un.gateway);
877 			putc(' ');
878 				break;
879 #if (CONFIG_COMMANDS & CFG_CMD_PING)
880 			case ICMP_ECHO_REPLY:
881 				/*
882 				 *	IP header OK.  Pass the packet to the current handler.
883 				 */
884 				/* XXX point to ip packet */
885 				(*packetHandler)((uchar *)ip, 0, 0, 0);
886 				break;
887 #endif
888 			default:
889 				return;
890 			}
891 		} else if (ip->ip_p != IPPROTO_UDP) {	/* Only UDP packets */
892 			return;
893 		}
894 
895 		/*
896 		 *	IP header OK.  Pass the packet to the current handler.
897 		 */
898 		(*packetHandler)((uchar *)ip +IP_HDR_SIZE,
899 						ntohs(ip->udp_dst),
900 						ntohs(ip->udp_src),
901 						ntohs(ip->udp_len) - 8);
902 
903 		break;
904 	}
905 }
906 
907 
908 /**********************************************************************/
909 
910 static int net_check_prereq (proto_t protocol)
911 {
912 	switch (protocol) {
913 			/* Fall through */
914 #if (CONFIG_COMMANDS & CFG_CMD_PING)
915 	case PING:
916 			if (NetPingIP == 0) {
917 				puts ("*** ERROR: ping address not given\n");
918 				return (1);
919 			}
920 			goto common;
921 #endif
922 	case TFTP:
923 			if (NetServerIP == 0) {
924 				puts ("*** ERROR: `serverip' not set\n");
925 				return (1);
926 			}
927 
928 #if (CONFIG_COMMANDS & CFG_CMD_PING)
929 		common:
930 #endif
931 
932 			if (NetOurIP == 0) {
933 				puts ("*** ERROR: `ipaddr' not set\n");
934 				return (1);
935 			}
936 			/* Fall through */
937 
938 	case DHCP:
939 	case RARP:
940 	case BOOTP:
941 			if (memcmp(NetOurEther, "\0\0\0\0\0\0", 6) == 0) {
942 #ifdef CONFIG_NET_MULTI
943 			    extern int eth_get_dev_index (void);
944 			    int num = eth_get_dev_index();
945 
946 			    switch (num) {
947 			    case -1:
948 				puts ("*** ERROR: No ethernet found.\n");
949 				return (1);
950 			    case 0:
951 				puts ("*** ERROR: `ethaddr' not set\n");
952 				break;
953 			    default:
954 				printf ("*** ERROR: `eth%daddr' not set\n",
955 					num);
956 				break;
957 			    }
958 
959 			    NetStartAgain ();
960 			    return (2);
961 #else
962 			    puts ("*** ERROR: `ethaddr' not set\n");
963 			    return (1);
964 #endif
965 			}
966 			/* Fall through */
967 		default:
968 			return(0);
969 	}
970 	return (0);	/* OK */
971 }
972 /**********************************************************************/
973 
974 int
975 NetCksumOk(uchar * ptr, int len)
976 {
977 	return !((NetCksum(ptr, len) + 1) & 0xfffe);
978 }
979 
980 
981 unsigned
982 NetCksum(uchar * ptr, int len)
983 {
984 	ulong	xsum;
985 
986 	xsum = 0;
987 	while (len-- > 0)
988 		xsum += *((ushort *)ptr)++;
989 	xsum = (xsum & 0xffff) + (xsum >> 16);
990 	xsum = (xsum & 0xffff) + (xsum >> 16);
991 	return (xsum & 0xffff);
992 }
993 
994 
995 void
996 NetSetEther(volatile uchar * xet, uchar * addr, uint prot)
997 {
998 	Ethernet_t *et = (Ethernet_t *)xet;
999 
1000 	memcpy (et->et_dest, addr, 6);
1001 	memcpy (et->et_src, NetOurEther, 6);
1002 	et->et_protlen = htons(prot);
1003 }
1004 
1005 
1006 void
1007 NetSetIP(volatile uchar * xip, IPaddr_t dest, int dport, int sport, int len)
1008 {
1009 	volatile IP_t *ip = (IP_t *)xip;
1010 
1011 	/*
1012 	 *	If the data is an odd number of bytes, zero the
1013 	 *	byte after the last byte so that the checksum
1014 	 *	will work.
1015 	 */
1016 	if (len & 1)
1017 		xip[IP_HDR_SIZE + len] = 0;
1018 
1019 	/*
1020 	 *	Construct an IP and UDP header.
1021 			(need to set no fragment bit - XXX)
1022 	 */
1023 	ip->ip_hl_v  = 0x45;		/* IP_HDR_SIZE / 4 (not including UDP) */
1024 	ip->ip_tos   = 0;
1025 	ip->ip_len   = htons(IP_HDR_SIZE + len);
1026 	ip->ip_id    = htons(NetIPID++);
1027 	ip->ip_off   = htons(0x4000);	/* No fragmentation */
1028 	ip->ip_ttl   = 255;
1029 	ip->ip_p     = 17;		/* UDP */
1030 	ip->ip_sum   = 0;
1031 	NetCopyIP((void*)&ip->ip_src, &NetOurIP); /* already in network byte order */
1032 	NetCopyIP((void*)&ip->ip_dst, &dest);	   /* - "" - */
1033 	ip->udp_src  = htons(sport);
1034 	ip->udp_dst  = htons(dport);
1035 	ip->udp_len  = htons(8 + len);
1036 	ip->udp_xsum = 0;
1037 	ip->ip_sum   = ~NetCksum((uchar *)ip, IP_HDR_SIZE_NO_UDP / 2);
1038 }
1039 
1040 void copy_filename (uchar *dst, uchar *src, int size)
1041 {
1042 	if (*src && (*src == '"')) {
1043 		++src;
1044 		--size;
1045 	}
1046 
1047 	while ((--size > 0) && *src && (*src != '"')) {
1048 		*dst++ = *src++;
1049 	}
1050 	*dst = '\0';
1051 }
1052 
1053 #endif /* CFG_CMD_NET */
1054 
1055 void ip_to_string (IPaddr_t x, char *s)
1056 {
1057     x = ntohl(x);
1058     sprintf (s,"%d.%d.%d.%d",
1059 	(int)((x >> 24) & 0xff),
1060 	(int)((x >> 16) & 0xff),
1061 	(int)((x >>  8) & 0xff),
1062 	(int)((x >>  0) & 0xff)
1063     );
1064 }
1065 
1066 IPaddr_t string_to_ip(char *s)
1067 {
1068 	IPaddr_t addr;
1069 	char *e;
1070 	int i;
1071 
1072 	if (s == NULL)
1073 		return(0);
1074 
1075 	for (addr=0, i=0; i<4; ++i) {
1076 		ulong val = s ? simple_strtoul(s, &e, 10) : 0;
1077 		addr <<= 8;
1078 		addr |= (val & 0xFF);
1079 		if (s) {
1080 			s = (*e) ? e+1 : e;
1081 		}
1082 	}
1083 
1084 	return (htonl(addr));
1085 }
1086 
1087 void print_IPaddr (IPaddr_t x)
1088 {
1089     char tmp[16];
1090 
1091     ip_to_string(x, tmp);
1092 
1093     puts(tmp);
1094 }
1095 
1096 IPaddr_t getenv_IPaddr (char *var)
1097 {
1098 	return (string_to_ip(getenv(var)));
1099 }
1100