xref: /openbmc/u-boot/net/bootp.c (revision 8c6407fc)
1 /*
2  *	Based on LiMon - BOOTP.
3  *
4  *	Copyright 1994, 1995, 2000 Neil Russell.
5  *	(See License)
6  *	Copyright 2000 Roland Borde
7  *	Copyright 2000 Paolo Scaffardi
8  *	Copyright 2000-2004 Wolfgang Denk, wd@denx.de
9  */
10 
11 #include <common.h>
12 #include <command.h>
13 #include <net.h>
14 #include "bootp.h"
15 #include "tftp.h"
16 #include "nfs.h"
17 #ifdef CONFIG_STATUS_LED
18 #include <status_led.h>
19 #endif
20 
21 #define BOOTP_VENDOR_MAGIC	0x63825363	/* RFC1048 Magic Cookie		*/
22 
23 #define TIMEOUT		5000UL	/* Milliseconds before trying BOOTP again */
24 #ifndef CONFIG_NET_RETRY_COUNT
25 # define TIMEOUT_COUNT	5		/* # of timeouts before giving up  */
26 #else
27 # define TIMEOUT_COUNT	(CONFIG_NET_RETRY_COUNT)
28 #endif
29 
30 #define PORT_BOOTPS	67		/* BOOTP server UDP port		*/
31 #define PORT_BOOTPC	68		/* BOOTP client UDP port		*/
32 
33 #ifndef CONFIG_DHCP_MIN_EXT_LEN		/* minimal length of extension list	*/
34 #define CONFIG_DHCP_MIN_EXT_LEN 64
35 #endif
36 
37 ulong		BootpID;
38 int		BootpTry;
39 #ifdef CONFIG_BOOTP_RANDOM_DELAY
40 ulong		seed1, seed2;
41 #endif
42 
43 #if defined(CONFIG_CMD_DHCP)
44 dhcp_state_t dhcp_state = INIT;
45 unsigned long dhcp_leasetime = 0;
46 IPaddr_t NetDHCPServerIP = 0;
47 static void DhcpHandler(uchar *pkt, unsigned dest, IPaddr_t sip, unsigned src,
48 			unsigned len);
49 
50 /* For Debug */
51 #if 0
52 static char *dhcpmsg2str(int type)
53 {
54 	switch (type) {
55 	case 1:	 return "DHCPDISCOVER"; break;
56 	case 2:	 return "DHCPOFFER";	break;
57 	case 3:	 return "DHCPREQUEST";	break;
58 	case 4:	 return "DHCPDECLINE";	break;
59 	case 5:	 return "DHCPACK";	break;
60 	case 6:	 return "DHCPNACK";	break;
61 	case 7:	 return "DHCPRELEASE";	break;
62 	default: return "UNKNOWN/INVALID MSG TYPE"; break;
63 	}
64 }
65 #endif
66 
67 #if defined(CONFIG_BOOTP_VENDOREX)
68 extern u8 *dhcp_vendorex_prep (u8 *e); /*rtn new e after add own opts. */
69 extern u8 *dhcp_vendorex_proc (u8 *e); /*rtn next e if mine,else NULL  */
70 #endif
71 
72 #endif
73 
74 static int BootpCheckPkt(uchar *pkt, unsigned dest, unsigned src, unsigned len)
75 {
76 	Bootp_t *bp = (Bootp_t *) pkt;
77 	int retval = 0;
78 
79 	if (dest != PORT_BOOTPC || src != PORT_BOOTPS)
80 		retval = -1;
81 	else if (len < sizeof (Bootp_t) - OPT_SIZE)
82 		retval = -2;
83 	else if (bp->bp_op != OP_BOOTREQUEST &&
84 	    bp->bp_op != OP_BOOTREPLY &&
85 	    bp->bp_op != DHCP_OFFER &&
86 	    bp->bp_op != DHCP_ACK &&
87 	    bp->bp_op != DHCP_NAK ) {
88 		retval = -3;
89 	}
90 	else if (bp->bp_htype != HWT_ETHER)
91 		retval = -4;
92 	else if (bp->bp_hlen != HWL_ETHER)
93 		retval = -5;
94 	else if (NetReadLong((ulong*)&bp->bp_id) != BootpID) {
95 		retval = -6;
96 	}
97 
98 	debug("Filtering pkt = %d\n", retval);
99 
100 	return retval;
101 }
102 
103 /*
104  * Copy parameters of interest from BOOTP_REPLY/DHCP_OFFER packet
105  */
106 static void BootpCopyNetParams(Bootp_t *bp)
107 {
108 	IPaddr_t tmp_ip;
109 
110 	NetCopyIP(&NetOurIP, &bp->bp_yiaddr);
111 #if !defined(CONFIG_BOOTP_SERVERIP)
112 	NetCopyIP(&tmp_ip, &bp->bp_siaddr);
113 	if (tmp_ip != 0)
114 		NetCopyIP(&NetServerIP, &bp->bp_siaddr);
115 	memcpy (NetServerEther, ((Ethernet_t *)NetRxPacket)->et_src, 6);
116 #endif
117 	if (strlen(bp->bp_file) > 0)
118 		copy_filename (BootFile, bp->bp_file, sizeof(BootFile));
119 
120 	debug("Bootfile: %s\n", BootFile);
121 
122 	/* Propagate to environment:
123 	 * don't delete exising entry when BOOTP / DHCP reply does
124 	 * not contain a new value
125 	 */
126 	if (*BootFile) {
127 		setenv ("bootfile", BootFile);
128 	}
129 }
130 
131 static int truncate_sz (const char *name, int maxlen, int curlen)
132 {
133 	if (curlen >= maxlen) {
134 		printf("*** WARNING: %s is too long (%d - max: %d) - truncated\n",
135 			name, curlen, maxlen);
136 		curlen = maxlen - 1;
137 	}
138 	return (curlen);
139 }
140 
141 #if !defined(CONFIG_CMD_DHCP)
142 
143 static void BootpVendorFieldProcess (u8 * ext)
144 {
145 	int size = *(ext + 1);
146 
147 	debug("[BOOTP] Processing extension %d... (%d bytes)\n", *ext,
148 		   *(ext + 1));
149 
150 	NetBootFileSize = 0;
151 
152 	switch (*ext) {
153 		/* Fixed length fields */
154 	case 1:			/* Subnet mask					*/
155 		if (NetOurSubnetMask == 0)
156 			NetCopyIP (&NetOurSubnetMask, (IPaddr_t *) (ext + 2));
157 		break;
158 	case 2:			/* Time offset - Not yet supported		*/
159 		break;
160 		/* Variable length fields */
161 	case 3:			/* Gateways list				*/
162 		if (NetOurGatewayIP == 0) {
163 			NetCopyIP (&NetOurGatewayIP, (IPaddr_t *) (ext + 2));
164 		}
165 		break;
166 	case 4:			/* Time server - Not yet supported		*/
167 		break;
168 	case 5:			/* IEN-116 name server - Not yet supported	*/
169 		break;
170 	case 6:
171 		if (NetOurDNSIP == 0) {
172 			NetCopyIP (&NetOurDNSIP, (IPaddr_t *) (ext + 2));
173 		}
174 #if defined(CONFIG_BOOTP_DNS2)
175 		if ((NetOurDNS2IP == 0) && (size > 4)) {
176 			NetCopyIP (&NetOurDNS2IP, (IPaddr_t *) (ext + 2 + 4));
177 		}
178 #endif
179 		break;
180 	case 7:			/* Log server - Not yet supported		*/
181 		break;
182 	case 8:			/* Cookie/Quote server - Not yet supported	*/
183 		break;
184 	case 9:			/* LPR server - Not yet supported		*/
185 		break;
186 	case 10:		/* Impress server - Not yet supported		*/
187 		break;
188 	case 11:		/* RPL server - Not yet supported		*/
189 		break;
190 	case 12:		/* Host name					*/
191 		if (NetOurHostName[0] == 0) {
192 			size = truncate_sz ("Host Name", sizeof (NetOurHostName), size);
193 			memcpy (&NetOurHostName, ext + 2, size);
194 			NetOurHostName[size] = 0;
195 		}
196 		break;
197 	case 13:		/* Boot file size				*/
198 		if (size == 2)
199 			NetBootFileSize = ntohs (*(ushort *) (ext + 2));
200 		else if (size == 4)
201 			NetBootFileSize = ntohl (*(ulong *) (ext + 2));
202 		break;
203 	case 14:		/* Merit dump file - Not yet supported		*/
204 		break;
205 	case 15:		/* Domain name - Not yet supported		*/
206 		break;
207 	case 16:		/* Swap server - Not yet supported		*/
208 		break;
209 	case 17:		/* Root path					*/
210 		if (NetOurRootPath[0] == 0) {
211 			size = truncate_sz ("Root Path", sizeof (NetOurRootPath), size);
212 			memcpy (&NetOurRootPath, ext + 2, size);
213 			NetOurRootPath[size] = 0;
214 		}
215 		break;
216 	case 18:		/* Extension path - Not yet supported		*/
217 		/*
218 		 * This can be used to send the information of the
219 		 * vendor area in another file that the client can
220 		 * access via TFTP.
221 		 */
222 		break;
223 		/* IP host layer fields */
224 	case 40:		/* NIS Domain name				*/
225 		if (NetOurNISDomain[0] == 0) {
226 			size = truncate_sz ("NIS Domain Name", sizeof (NetOurNISDomain), size);
227 			memcpy (&NetOurNISDomain, ext + 2, size);
228 			NetOurNISDomain[size] = 0;
229 		}
230 		break;
231 		/* Application layer fields */
232 	case 43:		/* Vendor specific info - Not yet supported	*/
233 		/*
234 		 * Binary information to exchange specific
235 		 * product information.
236 		 */
237 		break;
238 		/* Reserved (custom) fields (128..254) */
239 	}
240 }
241 
242 static void BootpVendorProcess (u8 * ext, int size)
243 {
244 	u8 *end = ext + size;
245 
246 	debug("[BOOTP] Checking extension (%d bytes)...\n", size);
247 
248 	while ((ext < end) && (*ext != 0xff)) {
249 		if (*ext == 0) {
250 			ext++;
251 		} else {
252 			u8 *opt = ext;
253 
254 			ext += ext[1] + 2;
255 			if (ext <= end)
256 				BootpVendorFieldProcess (opt);
257 		}
258 	}
259 
260 	debug("[BOOTP] Received fields: \n");
261 	if (NetOurSubnetMask)
262 		debug("NetOurSubnetMask : %pI4\n", &NetOurSubnetMask);
263 
264 	if (NetOurGatewayIP)
265 		debug("NetOurGatewayIP	: %pI4", &NetOurGatewayIP);
266 
267 	if (NetBootFileSize)
268 		debug("NetBootFileSize : %d\n", NetBootFileSize);
269 
270 	if (NetOurHostName[0])
271 		debug("NetOurHostName  : %s\n", NetOurHostName);
272 
273 	if (NetOurRootPath[0])
274 		debug("NetOurRootPath  : %s\n", NetOurRootPath);
275 
276 	if (NetOurNISDomain[0])
277 		debug("NetOurNISDomain : %s\n", NetOurNISDomain);
278 
279 	if (NetBootFileSize)
280 		debug("NetBootFileSize: %d\n", NetBootFileSize);
281 }
282 /*
283  *	Handle a BOOTP received packet.
284  */
285 static void
286 BootpHandler(uchar *pkt, unsigned dest, IPaddr_t sip, unsigned src,
287 	     unsigned len)
288 {
289 	Bootp_t *bp;
290 	char	*s;
291 
292 	debug("got BOOTP packet (src=%d, dst=%d, len=%d want_len=%zu)\n",
293 		src, dest, len, sizeof (Bootp_t));
294 
295 	bp = (Bootp_t *)pkt;
296 
297 	if (BootpCheckPkt(pkt, dest, src, len)) /* Filter out pkts we don't want */
298 		return;
299 
300 	/*
301 	 *	Got a good BOOTP reply.	 Copy the data into our variables.
302 	 */
303 #ifdef CONFIG_STATUS_LED
304 	status_led_set (STATUS_LED_BOOT, STATUS_LED_OFF);
305 #endif
306 
307 	BootpCopyNetParams(bp);		/* Store net parameters from reply */
308 
309 	/* Retrieve extended information (we must parse the vendor area) */
310 	if (NetReadLong((ulong*)&bp->bp_vend[0]) == htonl(BOOTP_VENDOR_MAGIC))
311 		BootpVendorProcess((uchar *)&bp->bp_vend[4], len);
312 
313 	NetSetTimeout(0, (thand_f *)0);
314 
315 	debug("Got good BOOTP\n");
316 
317 	if ((s = getenv("autoload")) != NULL) {
318 		if (*s == 'n') {
319 			/*
320 			 * Just use BOOTP to configure system;
321 			 * Do not use TFTP to load the bootfile.
322 			 */
323 			NetState = NETLOOP_SUCCESS;
324 			return;
325 #if defined(CONFIG_CMD_NFS)
326 		} else if (strcmp(s, "NFS") == 0) {
327 			/*
328 			 * Use NFS to load the bootfile.
329 			 */
330 			NfsStart();
331 			return;
332 #endif
333 		}
334 	}
335 
336 	TftpStart();
337 }
338 #endif
339 
340 /*
341  *	Timeout on BOOTP/DHCP request.
342  */
343 static void
344 BootpTimeout(void)
345 {
346 	if (BootpTry >= TIMEOUT_COUNT) {
347 		puts ("\nRetry count exceeded; starting again\n");
348 		NetStartAgain ();
349 	} else {
350 		NetSetTimeout (TIMEOUT, BootpTimeout);
351 		BootpRequest ();
352 	}
353 }
354 
355 /*
356  *	Initialize BOOTP extension fields in the request.
357  */
358 #if defined(CONFIG_CMD_DHCP)
359 static int DhcpExtended (u8 * e, int message_type, IPaddr_t ServerID, IPaddr_t RequestedIP)
360 {
361 	u8 *start = e;
362 	u8 *cnt;
363 
364 #if defined(CONFIG_BOOTP_VENDOREX)
365 	u8 *x;
366 #endif
367 #if defined(CONFIG_BOOTP_SEND_HOSTNAME)
368 	char *hostname;
369 #endif
370 
371 	*e++ = 99;		/* RFC1048 Magic Cookie */
372 	*e++ = 130;
373 	*e++ = 83;
374 	*e++ = 99;
375 
376 	*e++ = 53;		/* DHCP Message Type */
377 	*e++ = 1;
378 	*e++ = message_type;
379 
380 	*e++ = 57;		/* Maximum DHCP Message Size */
381 	*e++ = 2;
382 	*e++ = (576 - 312 + OPT_SIZE) >> 8;
383 	*e++ = (576 - 312 + OPT_SIZE) & 0xff;
384 
385 	if (ServerID) {
386 		int tmp = ntohl (ServerID);
387 
388 		*e++ = 54;	/* ServerID */
389 		*e++ = 4;
390 		*e++ = tmp >> 24;
391 		*e++ = tmp >> 16;
392 		*e++ = tmp >> 8;
393 		*e++ = tmp & 0xff;
394 	}
395 
396 	if (RequestedIP) {
397 		int tmp = ntohl (RequestedIP);
398 
399 		*e++ = 50;	/* Requested IP */
400 		*e++ = 4;
401 		*e++ = tmp >> 24;
402 		*e++ = tmp >> 16;
403 		*e++ = tmp >> 8;
404 		*e++ = tmp & 0xff;
405 	}
406 #if defined(CONFIG_BOOTP_SEND_HOSTNAME)
407 	if ((hostname = getenv ("hostname"))) {
408 		int hostnamelen = strlen (hostname);
409 
410 		*e++ = 12;	/* Hostname */
411 		*e++ = hostnamelen;
412 		memcpy (e, hostname, hostnamelen);
413 		e += hostnamelen;
414 	}
415 #endif
416 
417 #if defined(CONFIG_BOOTP_VENDOREX)
418 	if ((x = dhcp_vendorex_prep (e)))
419 		return x - start;
420 #endif
421 
422 	*e++ = 55;		/* Parameter Request List */
423 	 cnt = e++;		/* Pointer to count of requested items */
424 	*cnt = 0;
425 #if defined(CONFIG_BOOTP_SUBNETMASK)
426 	*e++  = 1;		/* Subnet Mask */
427 	*cnt += 1;
428 #endif
429 #if defined(CONFIG_BOOTP_TIMEOFFSET)
430 	*e++  = 2;
431 	*cnt += 1;
432 #endif
433 #if defined(CONFIG_BOOTP_GATEWAY)
434 	*e++  = 3;		/* Router Option */
435 	*cnt += 1;
436 #endif
437 #if defined(CONFIG_BOOTP_DNS)
438 	*e++  = 6;		/* DNS Server(s) */
439 	*cnt += 1;
440 #endif
441 #if defined(CONFIG_BOOTP_HOSTNAME)
442 	*e++  = 12;		/* Hostname */
443 	*cnt += 1;
444 #endif
445 #if defined(CONFIG_BOOTP_BOOTFILESIZE)
446 	*e++  = 13;		/* Boot File Size */
447 	*cnt += 1;
448 #endif
449 #if defined(CONFIG_BOOTP_BOOTPATH)
450 	*e++  = 17;		/* Boot path */
451 	*cnt += 1;
452 #endif
453 #if defined(CONFIG_BOOTP_NISDOMAIN)
454 	*e++  = 40;		/* NIS Domain name request */
455 	*cnt += 1;
456 #endif
457 #if defined(CONFIG_BOOTP_NTPSERVER)
458 	*e++  = 42;
459 	*cnt += 1;
460 #endif
461 	/* no options, so back up to avoid sending an empty request list */
462 	if (*cnt == 0)
463 		e -= 2;
464 
465 	*e++  = 255;		/* End of the list */
466 
467 	/* Pad to minimal length */
468 #ifdef	CONFIG_DHCP_MIN_EXT_LEN
469 	while ((e - start) < CONFIG_DHCP_MIN_EXT_LEN)
470 		*e++ = 0;
471 #endif
472 
473 	return e - start;
474 }
475 
476 #else
477 /*
478  *	Warning: no field size check - change CONFIG_BOOTP_* at your own risk!
479  */
480 static int BootpExtended (u8 * e)
481 {
482 	u8 *start = e;
483 
484 	*e++ = 99;		/* RFC1048 Magic Cookie */
485 	*e++ = 130;
486 	*e++ = 83;
487 	*e++ = 99;
488 
489 #if defined(CONFIG_CMD_DHCP)
490 	*e++ = 53;		/* DHCP Message Type */
491 	*e++ = 1;
492 	*e++ = DHCP_DISCOVER;
493 
494 	*e++ = 57;		/* Maximum DHCP Message Size */
495 	*e++ = 2;
496 	*e++ = (576 - 312 + OPT_SIZE) >> 16;
497 	*e++ = (576 - 312 + OPT_SIZE) & 0xff;
498 #endif
499 
500 #if defined(CONFIG_BOOTP_SUBNETMASK)
501 	*e++ = 1;		/* Subnet mask request */
502 	*e++ = 4;
503 	e   += 4;
504 #endif
505 
506 #if defined(CONFIG_BOOTP_GATEWAY)
507 	*e++ = 3;		/* Default gateway request */
508 	*e++ = 4;
509 	e   += 4;
510 #endif
511 
512 #if defined(CONFIG_BOOTP_DNS)
513 	*e++ = 6;		/* Domain Name Server */
514 	*e++ = 4;
515 	e   += 4;
516 #endif
517 
518 #if defined(CONFIG_BOOTP_HOSTNAME)
519 	*e++ = 12;		/* Host name request */
520 	*e++ = 32;
521 	e   += 32;
522 #endif
523 
524 #if defined(CONFIG_BOOTP_BOOTFILESIZE)
525 	*e++ = 13;		/* Boot file size */
526 	*e++ = 2;
527 	e   += 2;
528 #endif
529 
530 #if defined(CONFIG_BOOTP_BOOTPATH)
531 	*e++ = 17;		/* Boot path */
532 	*e++ = 32;
533 	e   += 32;
534 #endif
535 
536 #if defined(CONFIG_BOOTP_NISDOMAIN)
537 	*e++ = 40;		/* NIS Domain name request */
538 	*e++ = 32;
539 	e   += 32;
540 #endif
541 
542 	*e++ = 255;		/* End of the list */
543 
544 	return e - start;
545 }
546 #endif
547 
548 void
549 BootpRequest (void)
550 {
551 	volatile uchar *pkt, *iphdr;
552 	Bootp_t *bp;
553 	int ext_len, pktlen, iplen;
554 
555 #if defined(CONFIG_CMD_DHCP)
556 	dhcp_state = INIT;
557 #endif
558 
559 #ifdef CONFIG_BOOTP_RANDOM_DELAY		/* Random BOOTP delay */
560 	unsigned char bi_enetaddr[6];
561 	int   reg;
562 	ulong tst1, tst2, sum, m_mask, m_value = 0;
563 
564 	if (BootpTry ==0) {
565 		/* get our mac */
566 		eth_getenv_enetaddr("ethaddr", bi_enetaddr);
567 
568 		debug("BootpRequest => Our Mac: ");
569 		for (reg=0; reg<6; reg++)
570 			debug("%x%c", bi_enetaddr[reg], reg==5 ? '\n' : ':');
571 
572 		/* Mac-Manipulation 2 get seed1 */
573 		tst1=0;
574 		tst2=0;
575 		for (reg=2; reg<6; reg++) {
576 			tst1 = tst1 << 8;
577 			tst1 = tst1 | bi_enetaddr[reg];
578 		}
579 		for (reg=0; reg<2; reg++) {
580 			tst2 = tst2 | bi_enetaddr[reg];
581 			tst2 = tst2 << 8;
582 		}
583 
584 		seed1 = tst1^tst2;
585 
586 		/* Mirror seed1*/
587 		m_mask=0x1;
588 		for (reg=1;reg<=32;reg++) {
589 			m_value |= (m_mask & seed1);
590 			seed1 = seed1 >> 1;
591 			m_value = m_value << 1;
592 		}
593 		seed1 = m_value;
594 		seed2 = 0xB78D0945;
595 	}
596 
597 	/* Random Number Generator */
598 
599 	for (reg=0;reg<=0;reg++) {
600 		sum = seed1 + seed2;
601 		if (sum < seed1 || sum < seed2)
602 			sum++;
603 		seed2 = seed1;
604 		seed1 = sum;
605 
606 		if (BootpTry<=2) {	/* Start with max 1024 * 1ms */
607 			sum = sum >> (22-BootpTry);
608 		} else {		/*After 3rd BOOTP request max 8192 * 1ms */
609 			sum = sum >> 19;
610 		}
611 	}
612 
613 	printf ("Random delay: %ld ms...\n", sum);
614 	for (reg=0; reg <sum; reg++) {
615 		udelay(1000); /*Wait 1ms*/
616 	}
617 #endif	/* CONFIG_BOOTP_RANDOM_DELAY */
618 
619 	printf("BOOTP broadcast %d\n", ++BootpTry);
620 	pkt = NetTxPacket;
621 	memset ((void*)pkt, 0, PKTSIZE);
622 
623 	pkt += NetSetEther(pkt, NetBcastAddr, PROT_IP);
624 
625 	/*
626 	 * Next line results in incorrect packet size being transmitted, resulting
627 	 * in errors in some DHCP servers, reporting missing bytes.  Size must be
628 	 * set in packet header after extension length has been determined.
629 	 * C. Hallinan, DS4.COM, Inc.
630 	 */
631 	/* NetSetIP(pkt, 0xFFFFFFFFL, PORT_BOOTPS, PORT_BOOTPC, sizeof (Bootp_t)); */
632 	iphdr = pkt;	/* We need this later for NetSetIP() */
633 	pkt += IP_HDR_SIZE;
634 
635 	bp = (Bootp_t *)pkt;
636 	bp->bp_op = OP_BOOTREQUEST;
637 	bp->bp_htype = HWT_ETHER;
638 	bp->bp_hlen = HWL_ETHER;
639 	bp->bp_hops = 0;
640 	bp->bp_secs = htons(get_timer(0) / 1000);
641 	NetWriteIP(&bp->bp_ciaddr, 0);
642 	NetWriteIP(&bp->bp_yiaddr, 0);
643 	NetWriteIP(&bp->bp_siaddr, 0);
644 	NetWriteIP(&bp->bp_giaddr, 0);
645 	memcpy (bp->bp_chaddr, NetOurEther, 6);
646 	copy_filename (bp->bp_file, BootFile, sizeof(bp->bp_file));
647 
648 	/* Request additional information from the BOOTP/DHCP server */
649 #if defined(CONFIG_CMD_DHCP)
650 	ext_len = DhcpExtended((u8 *)bp->bp_vend, DHCP_DISCOVER, 0, 0);
651 #else
652 	ext_len = BootpExtended((u8 *)bp->bp_vend);
653 #endif
654 
655 	/*
656 	 *	Bootp ID is the lower 4 bytes of our ethernet address
657 	 *	plus the current time in ms.
658 	 */
659 	BootpID = ((ulong)NetOurEther[2] << 24)
660 		| ((ulong)NetOurEther[3] << 16)
661 		| ((ulong)NetOurEther[4] << 8)
662 		| (ulong)NetOurEther[5];
663 	BootpID += get_timer(0);
664 	BootpID	 = htonl(BootpID);
665 	NetCopyLong(&bp->bp_id, &BootpID);
666 
667 	/*
668 	 * Calculate proper packet lengths taking into account the
669 	 * variable size of the options field
670 	 */
671 	pktlen = ((int)(pkt-NetTxPacket)) + BOOTP_HDR_SIZE - sizeof(bp->bp_vend) + ext_len;
672 	iplen = BOOTP_HDR_SIZE - sizeof(bp->bp_vend) + ext_len;
673 	NetSetIP(iphdr, 0xFFFFFFFFL, PORT_BOOTPS, PORT_BOOTPC, iplen);
674 	NetSetTimeout(SELECT_TIMEOUT, BootpTimeout);
675 
676 #if defined(CONFIG_CMD_DHCP)
677 	dhcp_state = SELECTING;
678 	NetSetHandler(DhcpHandler);
679 #else
680 	NetSetHandler(BootpHandler);
681 #endif
682 	NetSendPacket(NetTxPacket, pktlen);
683 }
684 
685 #if defined(CONFIG_CMD_DHCP)
686 static void DhcpOptionsProcess (uchar * popt, Bootp_t *bp)
687 {
688 	uchar *end = popt + BOOTP_HDR_SIZE;
689 	int oplen, size;
690 #if defined(CONFIG_CMD_SNTP) && defined(CONFIG_BOOTP_TIMEOFFSET)
691 	int *to_ptr;
692 #endif
693 
694 	while (popt < end && *popt != 0xff) {
695 		oplen = *(popt + 1);
696 		switch (*popt) {
697 		case 1:
698 			NetCopyIP (&NetOurSubnetMask, (popt + 2));
699 			break;
700 #if defined(CONFIG_CMD_SNTP) && defined(CONFIG_BOOTP_TIMEOFFSET)
701 		case 2:		/* Time offset	*/
702 			to_ptr = &NetTimeOffset;
703 			NetCopyLong ((ulong *)to_ptr, (ulong *)(popt + 2));
704 			NetTimeOffset = ntohl (NetTimeOffset);
705 			break;
706 #endif
707 		case 3:
708 			NetCopyIP (&NetOurGatewayIP, (popt + 2));
709 			break;
710 		case 6:
711 			NetCopyIP (&NetOurDNSIP, (popt + 2));
712 #if defined(CONFIG_BOOTP_DNS2)
713 			if (*(popt + 1) > 4) {
714 				NetCopyIP (&NetOurDNS2IP, (popt + 2 + 4));
715 			}
716 #endif
717 			break;
718 		case 12:
719 			size = truncate_sz ("Host Name", sizeof (NetOurHostName), oplen);
720 			memcpy (&NetOurHostName, popt + 2, size);
721 			NetOurHostName[size] = 0;
722 			break;
723 		case 15:	/* Ignore Domain Name Option */
724 			break;
725 		case 17:
726 			size = truncate_sz ("Root Path", sizeof (NetOurRootPath), oplen);
727 			memcpy (&NetOurRootPath, popt + 2, size);
728 			NetOurRootPath[size] = 0;
729 			break;
730 #if defined(CONFIG_CMD_SNTP) && defined(CONFIG_BOOTP_NTPSERVER)
731 		case 42:	/* NTP server IP */
732 			NetCopyIP (&NetNtpServerIP, (popt + 2));
733 			break;
734 #endif
735 		case 51:
736 			NetCopyLong (&dhcp_leasetime, (ulong *) (popt + 2));
737 			break;
738 		case 53:	/* Ignore Message Type Option */
739 			break;
740 		case 54:
741 			NetCopyIP (&NetDHCPServerIP, (popt + 2));
742 			break;
743 		case 58:	/* Ignore Renewal Time Option */
744 			break;
745 		case 59:	/* Ignore Rebinding Time Option */
746 			break;
747 		case 66:	/* Ignore TFTP server name */
748 			break;
749 		case 67:	/* vendor opt bootfile */
750 			/*
751 			 * I can't use dhcp_vendorex_proc here because I need
752 			 * to write into the bootp packet - even then I had to
753 			 * pass the bootp packet pointer into here as the
754 			 * second arg
755 			 */
756 			size = truncate_sz ("Opt Boot File",
757 					    sizeof(bp->bp_file),
758 					    oplen);
759 			if (bp->bp_file[0] == '\0' && size > 0) {
760 				/*
761 				 * only use vendor boot file if we didn't
762 				 * receive a boot file in the main non-vendor
763 				 * part of the packet - god only knows why
764 				 * some vendors chose not to use this perfectly
765 				 * good spot to store the boot file (join on
766 				 * Tru64 Unix) it seems mind bogglingly crazy
767 				 * to me
768 				 */
769 				printf("*** WARNING: using vendor "
770 					"optional boot file\n");
771 				memcpy(bp->bp_file, popt + 2, size);
772 				bp->bp_file[size] = '\0';
773 			}
774 			break;
775 		default:
776 #if defined(CONFIG_BOOTP_VENDOREX)
777 			if (dhcp_vendorex_proc (popt))
778 				break;
779 #endif
780 			printf ("*** Unhandled DHCP Option in OFFER/ACK: %d\n", *popt);
781 			break;
782 		}
783 		popt += oplen + 2;	/* Process next option */
784 	}
785 }
786 
787 static int DhcpMessageType(unsigned char *popt)
788 {
789 	if (NetReadLong((ulong*)popt) != htonl(BOOTP_VENDOR_MAGIC))
790 		return -1;
791 
792 	popt += 4;
793 	while ( *popt != 0xff ) {
794 		if ( *popt == 53 )	/* DHCP Message Type */
795 			return *(popt + 2);
796 		popt += *(popt + 1) + 2;	/* Scan through all options */
797 	}
798 	return -1;
799 }
800 
801 static void DhcpSendRequestPkt(Bootp_t *bp_offer)
802 {
803 	volatile uchar *pkt, *iphdr;
804 	Bootp_t *bp;
805 	int pktlen, iplen, extlen;
806 	IPaddr_t OfferedIP;
807 
808 	debug("DhcpSendRequestPkt: Sending DHCPREQUEST\n");
809 	pkt = NetTxPacket;
810 	memset ((void*)pkt, 0, PKTSIZE);
811 
812 	pkt += NetSetEther(pkt, NetBcastAddr, PROT_IP);
813 
814 	iphdr = pkt;		/* We'll need this later to set proper pkt size */
815 	pkt += IP_HDR_SIZE;
816 
817 	bp = (Bootp_t *)pkt;
818 	bp->bp_op = OP_BOOTREQUEST;
819 	bp->bp_htype = HWT_ETHER;
820 	bp->bp_hlen = HWL_ETHER;
821 	bp->bp_hops = 0;
822 	bp->bp_secs = htons(get_timer(0) / 1000);
823 	/* Do not set the client IP, your IP, or server IP yet, since it hasn't been ACK'ed by
824 	 * the server yet */
825 
826 	/*
827 	 * RFC3046 requires Relay Agents to discard packets with
828 	 * nonzero and offered giaddr
829 	 */
830 	NetWriteIP(&bp->bp_giaddr, 0);
831 
832 	memcpy (bp->bp_chaddr, NetOurEther, 6);
833 
834 	/*
835 	 * ID is the id of the OFFER packet
836 	 */
837 
838 	NetCopyLong(&bp->bp_id, &bp_offer->bp_id);
839 
840 	/*
841 	 * Copy options from OFFER packet if present
842 	 */
843 
844 	/* Copy offered IP into the parameters request list */
845 	NetCopyIP(&OfferedIP, &bp_offer->bp_yiaddr);
846 	extlen = DhcpExtended((u8 *)bp->bp_vend, DHCP_REQUEST, NetDHCPServerIP, OfferedIP);
847 
848 	pktlen = ((int)(pkt-NetTxPacket)) + BOOTP_HDR_SIZE - sizeof(bp->bp_vend) + extlen;
849 	iplen = BOOTP_HDR_SIZE - sizeof(bp->bp_vend) + extlen;
850 	NetSetIP(iphdr, 0xFFFFFFFFL, PORT_BOOTPS, PORT_BOOTPC, iplen);
851 
852 	debug("Transmitting DHCPREQUEST packet: len = %d\n", pktlen);
853 #ifdef CONFIG_BOOTP_DHCP_REQUEST_DELAY
854 	udelay(CONFIG_BOOTP_DHCP_REQUEST_DELAY);
855 #endif	/* CONFIG_BOOTP_DHCP_REQUEST_DELAY */
856 	NetSendPacket(NetTxPacket, pktlen);
857 }
858 
859 /*
860  *	Handle DHCP received packets.
861  */
862 static void
863 DhcpHandler(uchar *pkt, unsigned dest, IPaddr_t sip, unsigned src,
864 	    unsigned len)
865 {
866 	Bootp_t *bp = (Bootp_t *)pkt;
867 
868 	debug("DHCPHandler: got packet: (src=%d, dst=%d, len=%d) state: %d\n",
869 		src, dest, len, dhcp_state);
870 
871 	if (BootpCheckPkt(pkt, dest, src, len)) /* Filter out pkts we don't want */
872 		return;
873 
874 	debug("DHCPHandler: got DHCP packet: (src=%d, dst=%d, len=%d) state: %d\n",
875 		src, dest, len, dhcp_state);
876 
877 	switch (dhcp_state) {
878 	case SELECTING:
879 		/*
880 		 * Wait an appropriate time for any potential DHCPOFFER packets
881 		 * to arrive.  Then select one, and generate DHCPREQUEST response.
882 		 * If filename is in format we recognize, assume it is a valid
883 		 * OFFER from a server we want.
884 		 */
885 		debug("DHCP: state=SELECTING bp_file: \"%s\"\n", bp->bp_file);
886 #ifdef CONFIG_SYS_BOOTFILE_PREFIX
887 		if (strncmp(bp->bp_file,
888 			    CONFIG_SYS_BOOTFILE_PREFIX,
889 			    strlen(CONFIG_SYS_BOOTFILE_PREFIX)) == 0 ) {
890 #endif	/* CONFIG_SYS_BOOTFILE_PREFIX */
891 
892 			debug("TRANSITIONING TO REQUESTING STATE\n");
893 			dhcp_state = REQUESTING;
894 
895 			if (NetReadLong((ulong*)&bp->bp_vend[0]) == htonl(BOOTP_VENDOR_MAGIC))
896 				DhcpOptionsProcess((u8 *)&bp->bp_vend[4], bp);
897 
898 			NetSetTimeout(TIMEOUT, BootpTimeout);
899 			DhcpSendRequestPkt(bp);
900 #ifdef CONFIG_SYS_BOOTFILE_PREFIX
901 		}
902 #endif	/* CONFIG_SYS_BOOTFILE_PREFIX */
903 
904 		return;
905 		break;
906 	case REQUESTING:
907 		debug("DHCP State: REQUESTING\n");
908 
909 		if ( DhcpMessageType((u8 *)bp->bp_vend) == DHCP_ACK ) {
910 			char *s;
911 
912 			if (NetReadLong((ulong*)&bp->bp_vend[0]) == htonl(BOOTP_VENDOR_MAGIC))
913 				DhcpOptionsProcess((u8 *)&bp->bp_vend[4], bp);
914 			BootpCopyNetParams(bp); /* Store net params from reply */
915 			dhcp_state = BOUND;
916 			printf ("DHCP client bound to address %pI4\n", &NetOurIP);
917 
918 			/* Obey the 'autoload' setting */
919 			if ((s = getenv("autoload")) != NULL) {
920 				if (*s == 'n') {
921 					/*
922 					 * Just use BOOTP to configure system;
923 					 * Do not use TFTP to load the bootfile.
924 					 */
925 					NetState = NETLOOP_SUCCESS;
926 					return;
927 #if defined(CONFIG_CMD_NFS)
928 				} else if (strcmp(s, "NFS") == 0) {
929 					/*
930 					 * Use NFS to load the bootfile.
931 					 */
932 					NfsStart();
933 					return;
934 #endif
935 				}
936 			}
937 			TftpStart();
938 			return;
939 		}
940 		break;
941 	case BOUND:
942 		/* DHCP client bound to address */
943 		break;
944 	default:
945 		puts ("DHCP: INVALID STATE\n");
946 		break;
947 	}
948 
949 }
950 
951 void DhcpRequest(void)
952 {
953 	BootpRequest();
954 }
955 #endif	/* CONFIG_CMD_DHCP */
956