xref: /openbmc/u-boot/net/net.c (revision e2211743) 
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 #include "arp.h"
69 
70 #if (CONFIG_COMMANDS & CFG_CMD_NET)
71 
72 #if 0
73 #define ET_DEBUG
74 #endif
75 
76 /** BOOTP EXTENTIONS **/
77 
78 IPaddr_t	NetOurSubnetMask=0;		/* Our subnet mask (0=unknown)	*/
79 IPaddr_t	NetOurGatewayIP=0;		/* Our gateways IP address	*/
80 IPaddr_t	NetOurDNSIP=0;			/* Our DNS IP address		*/
81 char		NetOurNISDomain[32]={0,};	/* Our NIS domain		*/
82 char		NetOurHostName[32]={0,};	/* Our hostname			*/
83 char		NetOurRootPath[64]={0,};	/* Our bootpath			*/
84 ushort		NetBootFileSize=0;		/* Our bootfile size in blocks	*/
85 
86 /** END OF BOOTP EXTENTIONS **/
87 
88 ulong		NetBootFileXferSize;	/* The actual transferred size of the bootfile (in bytes) */
89 uchar		NetOurEther[6];		/* Our ethernet address			*/
90 uchar		NetServerEther[6] =	/* Boot server enet address		*/
91 			{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
92 IPaddr_t	NetOurIP;		/* Our IP addr (0 = unknown)		*/
93 IPaddr_t	NetServerIP;		/* Our IP addr (0 = unknown)		*/
94 volatile uchar *NetRxPkt;		/* Current receive packet		*/
95 int		NetRxPktLen;		/* Current rx packet length		*/
96 unsigned	NetIPID;		/* IP packet ID				*/
97 uchar		NetBcastAddr[6] =	/* Ethernet bcast address		*/
98 			{ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
99 int		NetState;		/* Network loop state			*/
100 #ifdef CONFIG_NET_MULTI
101 int		NetRestartWrap = 0;	/* Tried all network devices		*/
102 static int	NetRestarted = 0;	/* Network loop restarted		*/
103 static int	NetDevExists = 0;	/* At least one device configured	*/
104 #endif
105 
106 char		BootFile[128];		/* Boot File name			*/
107 
108 volatile uchar	PktBuf[(PKTBUFSRX+1) * PKTSIZE_ALIGN + PKTALIGN];
109 
110 volatile uchar *NetRxPackets[PKTBUFSRX]; /* Receive packets			*/
111 
112 static rxhand_f *packetHandler;		/* Current RX packet handler		*/
113 static thand_f *timeHandler;		/* Current timeout handler		*/
114 static ulong	timeValue;		/* Current timeout value		*/
115 volatile uchar *NetTxPacket = 0;	/* THE transmit packet			*/
116 
117 static int net_check_prereq (proto_t protocol);
118 
119 /**********************************************************************/
120 /*
121  *	Main network processing loop.
122  */
123 
124 int
125 NetLoop(proto_t protocol)
126 {
127 	DECLARE_GLOBAL_DATA_PTR;
128 
129 	bd_t *bd = gd->bd;
130 
131 #ifdef CONFIG_NET_MULTI
132 	NetRestarted = 0;
133 	NetDevExists = 0;
134 #endif
135 
136 	if (!NetTxPacket) {
137 		int	i;
138 
139 		/*
140 		 *	Setup packet buffers, aligned correctly.
141 		 */
142 		NetTxPacket = &PktBuf[0] + (PKTALIGN - 1);
143 		NetTxPacket -= (ulong)NetTxPacket % PKTALIGN;
144 		for (i = 0; i < PKTBUFSRX; i++) {
145 			NetRxPackets[i] = NetTxPacket + (i+1)*PKTSIZE_ALIGN;
146 		}
147 	}
148 
149 	eth_halt();
150 	eth_init(bd);
151 
152 restart:
153 #ifdef CONFIG_NET_MULTI
154 	memcpy (NetOurEther, eth_get_dev()->enetaddr, 6);
155 #else
156 	memcpy (NetOurEther, bd->bi_enetaddr, 6);
157 #endif
158 
159 	NetState = NETLOOP_CONTINUE;
160 
161 	/*
162 	 *	Start the ball rolling with the given start function.  From
163 	 *	here on, this code is a state machine driven by received
164 	 *	packets and timer events.
165 	 */
166 
167 	switch (protocol) {
168 	case TFTP:
169 		NetCopyIP(&NetOurIP, &bd->bi_ip_addr);
170 		NetServerIP	= getenv_IPaddr ("serverip");
171 		NetOurGatewayIP = getenv_IPaddr ("gatewayip");
172 		NetOurSubnetMask= getenv_IPaddr ("netmask");
173 		break;
174 	case BOOTP:
175 	case RARP:
176 		/*
177                  * initialize our IP addr to 0 in order to accept ANY
178                  * IP addr assigned to us by the BOOTP / RARP server
179 		 */
180 		NetOurIP = 0;
181 		NetServerIP = 0;
182 		break;
183 	default:
184 		break;
185 	}
186 
187 	switch (net_check_prereq (protocol)) {
188 	case 1:
189 		/* network not configured */
190 		return 0;
191 
192 #ifdef CONFIG_NET_MULTI
193 	case 2:
194 		/* network device not configured */
195 		break;
196 #endif /* CONFIG_NET_MULTI */
197 
198 	case 0:
199 #ifdef CONFIG_NET_MULTI
200 		NetDevExists = 1;
201 #endif
202 		switch (protocol) {
203 		case TFTP:
204 			/* always use ARP to get server ethernet address */
205 			ArpTry = 0;
206 			ArpRequest ();
207 			break;
208 
209 #if (CONFIG_COMMANDS & CFG_CMD_DHCP)
210 		case DHCP:
211 			/* Start with a clean slate... */
212 			NetOurIP = 0;
213 			NetServerIP = 0;
214 			DhcpRequest();		/* Basically same as BOOTP */
215 			break;
216 #endif /* CFG_CMD_DHCP */
217 
218 		case BOOTP:
219 			BootpTry = 0;
220 			BootpRequest ();
221 			break;
222 
223 		case RARP:
224 			RarpTry = 0;
225 			RarpRequest ();
226 			break;
227 		default:
228 			break;
229 		}
230 
231 		NetBootFileXferSize = 0;
232 		break;
233 	}
234 
235 
236 	/*
237 	 *	Main packet reception loop.  Loop receiving packets until
238 	 *	someone sets `NetQuit'.
239 	 */
240 	for (;;) {
241 		WATCHDOG_RESET();
242 #ifdef CONFIG_SHOW_ACTIVITY
243 		{
244 			extern void show_activity(int arg);
245 			show_activity(1);
246 		}
247 #endif
248 		/*
249 		 *	Check the ethernet for a new packet.  The ethernet
250 		 *	receive routine will process it.
251 		 */
252 			eth_rx();
253 
254 		/*
255 		 *	Abort if ctrl-c was pressed.
256 		 */
257 		if (ctrlc()) {
258 		        eth_halt();
259 			printf("\nAbort\n");
260 			return 0;
261 		}
262 
263 
264 		/*
265 		 *	Check for a timeout, and run the timeout handler
266 		 *	if we have one.
267 		 */
268 		if (timeHandler && (get_timer(0) > timeValue)) {
269 			thand_f *x;
270 
271 			x = timeHandler;
272 			timeHandler = (thand_f *)0;
273 			(*x)();
274 		}
275 
276 
277 		switch (NetState) {
278 
279 		case NETLOOP_RESTART:
280 #ifdef CONFIG_NET_MULTI
281 			NetRestarted = 1;
282 #endif
283 			goto restart;
284 
285 		case NETLOOP_SUCCESS:
286 			if (NetBootFileXferSize > 0) {
287 				char buf[10];
288 				printf("Bytes transferred = %ld (%lx hex)\n",
289 					NetBootFileXferSize,
290 					NetBootFileXferSize);
291 				sprintf(buf, "%lx", NetBootFileXferSize);
292 				setenv("filesize", buf);
293 			}
294 			eth_halt();
295 			return NetBootFileXferSize;
296 
297 		case NETLOOP_FAIL:
298 			return 0;
299 		}
300 	}
301 }
302 
303 /**********************************************************************/
304 
305 static void
306 startAgainTimeout(void)
307 {
308 	NetState = NETLOOP_RESTART;
309 }
310 
311 static void
312 startAgainHandler(uchar * pkt, unsigned dest, unsigned src, unsigned len)
313 {
314 	/* Totally ignore the packet */
315 }
316 
317 void
318 NetStartAgain(void)
319 {
320 #ifndef CONFIG_NET_MULTI
321 	NetSetTimeout(10 * CFG_HZ, startAgainTimeout);
322 	NetSetHandler(startAgainHandler);
323 #else
324 	DECLARE_GLOBAL_DATA_PTR;
325 
326 	eth_halt();
327 	eth_try_another(!NetRestarted);
328 	eth_init(gd->bd);
329 	if (NetRestartWrap)
330 	{
331 		NetRestartWrap = 0;
332 		if (NetDevExists)
333 		{
334 			NetSetTimeout(10 * CFG_HZ, startAgainTimeout);
335 			NetSetHandler(startAgainHandler);
336 		}
337 		else
338 		{
339 			NetState = NETLOOP_FAIL;
340 		}
341 	}
342 	else
343 	{
344 		NetState = NETLOOP_RESTART;
345 	}
346 #endif
347 }
348 
349 /**********************************************************************/
350 /*
351  *	Miscelaneous bits.
352  */
353 
354 void
355 NetSetHandler(rxhand_f * f)
356 {
357 	packetHandler = f;
358 }
359 
360 
361 void
362 NetSetTimeout(int iv, thand_f * f)
363 {
364 	if (iv == 0) {
365 		timeHandler = (thand_f *)0;
366 	} else {
367 		timeHandler = f;
368 		timeValue = get_timer(0) + iv;
369 	}
370 }
371 
372 
373 void
374 NetSendPacket(volatile uchar * pkt, int len)
375 {
376 	(void) eth_send(pkt, len);
377 }
378 
379 
380 
381 void
382 NetReceive(volatile uchar * pkt, int len)
383 {
384 	Ethernet_t *et;
385 	IP_t	*ip;
386 	ARP_t	*arp;
387 	IPaddr_t tmp;
388 	int	x;
389 
390 
391 	NetRxPkt = pkt;
392 	NetRxPktLen = len;
393 	et = (Ethernet_t *)pkt;
394 
395 	x = ntohs(et->et_protlen);
396 
397 	if (x < 1514) {
398 		/*
399 		 *	Got a 802 packet.  Check the other protocol field.
400 		 */
401 		x = ntohs(et->et_prot);
402 		ip = (IP_t *)(pkt + E802_HDR_SIZE);
403 		len -= E802_HDR_SIZE;
404 	} else {
405 		ip = (IP_t *)(pkt + ETHER_HDR_SIZE);
406 		len -= ETHER_HDR_SIZE;
407 	}
408 
409 #ifdef ET_DEBUG
410 	printf("Receive from protocol 0x%x\n", x);
411 #endif
412 
413 	switch (x) {
414 
415 	case PROT_ARP:
416 		/*
417 		 * We have to deal with two types of ARP packets:
418                  * - REQUEST packets will be answered by sending  our
419                  *   IP address - if we know it.
420                  * - REPLY packates are expected only after we asked
421                  *   for the TFTP server's or the gateway's ethernet
422                  *   address; so if we receive such a packet, we set
423                  *   the server ethernet address
424 		 */
425 #ifdef ET_DEBUG
426 		printf("Got ARP\n");
427 #endif
428 		arp = (ARP_t *)ip;
429 		if (len < ARP_HDR_SIZE) {
430 			printf("bad length %d < %d\n", len, ARP_HDR_SIZE);
431 			return;
432 		}
433 		if (ntohs(arp->ar_hrd) != ARP_ETHER) {
434 			return;
435 		}
436 		if (ntohs(arp->ar_pro) != PROT_IP) {
437 			return;
438 		}
439 		if (arp->ar_hln != 6) {
440 			return;
441 		}
442 		if (arp->ar_pln != 4) {
443 			return;
444 		}
445 
446 		if (NetOurIP == 0) {
447 			return;
448 		}
449 
450 		if (NetReadIP(&arp->ar_data[16]) != NetOurIP) {
451 			return;
452 		}
453 
454 		switch (ntohs(arp->ar_op)) {
455 		case ARPOP_REQUEST:		/* reply with our IP address	*/
456 #ifdef ET_DEBUG
457 			printf("Got ARP REQUEST, return our IP\n");
458 #endif
459 			NetSetEther((uchar *)et, et->et_src, PROT_ARP);
460 			arp->ar_op = htons(ARPOP_REPLY);
461 			memcpy   (&arp->ar_data[10], &arp->ar_data[0], 6);
462 			NetCopyIP(&arp->ar_data[16], &arp->ar_data[6]);
463 			memcpy   (&arp->ar_data[ 0], NetOurEther, 6);
464 			NetCopyIP(&arp->ar_data[ 6], &NetOurIP);
465 			NetSendPacket((uchar *)et,((uchar *)arp-pkt)+ARP_HDR_SIZE);
466 			return;
467 		case ARPOP_REPLY:		/* set TFTP server eth addr	*/
468 #ifdef ET_DEBUG
469 			printf("Got ARP REPLY, set server/gtwy eth addr\n");
470 #endif
471 			memcpy (NetServerEther, &arp->ar_data[0], 6);
472 			(*packetHandler)(0,0,0,0);	/* start TFTP */
473 			return;
474 		default:
475 #ifdef ET_DEBUG
476 			printf("Unexpected ARP opcode 0x%x\n", ntohs(arp->ar_op));
477 #endif
478 			return;
479 		}
480 
481 	case PROT_RARP:
482 #ifdef ET_DEBUG
483 		printf("Got RARP\n");
484 #endif
485 		arp = (ARP_t *)ip;
486 		if (len < ARP_HDR_SIZE) {
487 			printf("bad length %d < %d\n", len, ARP_HDR_SIZE);
488 			return;
489 		}
490 
491 		if ((ntohs(arp->ar_op) != RARPOP_REPLY) ||
492 			(ntohs(arp->ar_hrd) != ARP_ETHER)   ||
493 			(ntohs(arp->ar_pro) != PROT_IP)     ||
494 			(arp->ar_hln != 6) || (arp->ar_pln != 4)) {
495 
496 			printf("invalid RARP header\n");
497 		} else {
498 			NetCopyIP(&NetOurIP,    &arp->ar_data[16]);
499 			NetCopyIP(&NetServerIP, &arp->ar_data[ 6]);
500 			memcpy (NetServerEther, &arp->ar_data[ 0], 6);
501 
502 			(*packetHandler)(0,0,0,0);
503 		}
504 		break;
505 
506 	case PROT_IP:
507 #ifdef ET_DEBUG
508 		printf("Got IP\n");
509 #endif
510 		if (len < IP_HDR_SIZE) {
511 			debug ("len bad %d < %d\n", len, IP_HDR_SIZE);
512 			return;
513 		}
514 		if (len < ntohs(ip->ip_len)) {
515 			printf("len bad %d < %d\n", len, ntohs(ip->ip_len));
516 			return;
517 		}
518 		len = ntohs(ip->ip_len);
519 #ifdef ET_DEBUG
520 		printf("len=%d, v=%02x\n", len, ip->ip_hl_v & 0xff);
521 #endif
522 		if ((ip->ip_hl_v & 0xf0) != 0x40) {
523 			return;
524 		}
525 		if (ip->ip_off & htons(0x1fff)) { /* Can't deal w/ fragments */
526 			return;
527 		}
528 		if (!NetCksumOk((uchar *)ip, IP_HDR_SIZE_NO_UDP / 2)) {
529 			printf("checksum bad\n");
530 			return;
531 		}
532 		tmp = NetReadIP(&ip->ip_dst);
533 		if (NetOurIP && tmp != NetOurIP && tmp != 0xFFFFFFFF) {
534 			return;
535 		}
536 		/*
537 		 * watch for ICMP host redirects
538 		 *
539                  * There is no real handler code (yet). We just watch
540                  * for ICMP host redirect messages. In case anybody
541                  * sees these messages: please contact me
542                  * (wd@denx.de), or - even better - send me the
543                  * necessary fixes :-)
544 		 *
545                  * Note: in all cases where I have seen this so far
546                  * it was a problem with the router configuration,
547                  * for instance when a router was configured in the
548                  * BOOTP reply, but the TFTP server was on the same
549                  * subnet. So this is probably a warning that your
550                  * configuration might be wrong. But I'm not really
551                  * sure if there aren't any other situations.
552 		 */
553 		if (ip->ip_p == IPPROTO_ICMP) {
554 			ICMP_t *icmph = (ICMP_t *)&(ip->udp_src);
555 
556 			if (icmph->type != ICMP_REDIRECT)
557 				return;
558 			if (icmph->code != ICMP_REDIR_HOST)
559 				return;
560 			puts (" ICMP Host Redirect to ");
561 			print_IPaddr(icmph->un.gateway);
562 			putc(' ');
563 		} else if (ip->ip_p != IPPROTO_UDP) {	/* Only UDP packets */
564 			return;
565 		}
566 
567 		/*
568 		 *	IP header OK.  Pass the packet to the current handler.
569 		 */
570 		(*packetHandler)((uchar *)ip +IP_HDR_SIZE,
571 						ntohs(ip->udp_dst),
572 						ntohs(ip->udp_src),
573 						ntohs(ip->udp_len) - 8);
574 
575 		break;
576 	}
577 }
578 
579 
580 /**********************************************************************/
581 
582 static int net_check_prereq (proto_t protocol)
583 {
584 	switch (protocol) {
585 	case ARP:	/* nothing to do */
586 			break;
587 
588 	case TFTP:
589 			if (NetServerIP == 0) {
590 				puts ("*** ERROR: `serverip' not set\n");
591 				return (1);
592 			}
593 
594 			if (NetOurIP == 0) {
595 				puts ("*** ERROR: `ipaddr' not set\n");
596 				return (1);
597 			}
598 			/* Fall through */
599 
600 	case DHCP:
601 	case RARP:
602 	case BOOTP:
603 			if (memcmp(NetOurEther, "\0\0\0\0\0\0", 6) == 0) {
604 #ifdef CONFIG_NET_MULTI
605 			    extern int eth_get_dev_index (void);
606 			    int num = eth_get_dev_index();
607 
608 			    switch (num) {
609 			    case -1:
610 				puts ("*** ERROR: No ethernet found.\n");
611 				return (1);
612 			    case 0:
613 				puts ("*** ERROR: `ethaddr' not set\n");
614 				break;
615 			    default:
616 			        printf ("*** ERROR: `eth%daddr' not set\n",
617 					num);
618 				break;
619 			    }
620 
621 			    NetStartAgain ();
622 			    return (2);
623 #else
624 			    puts ("*** ERROR: `ethaddr' not set\n");
625 			    return (1);
626 #endif
627 			}
628 			/* Fall through */
629 	}
630 	return (0);	/* OK */
631 }
632 /**********************************************************************/
633 
634 int
635 NetCksumOk(uchar * ptr, int len)
636 {
637 	return !((NetCksum(ptr, len) + 1) & 0xfffe);
638 }
639 
640 
641 unsigned
642 NetCksum(uchar * ptr, int len)
643 {
644 	ulong	xsum;
645 
646 	xsum = 0;
647 	while (len-- > 0)
648 		xsum += *((ushort *)ptr)++;
649 	xsum = (xsum & 0xffff) + (xsum >> 16);
650 	xsum = (xsum & 0xffff) + (xsum >> 16);
651 	return (xsum & 0xffff);
652 }
653 
654 
655 void
656 NetSetEther(volatile uchar * xet, uchar * addr, uint prot)
657 {
658 	Ethernet_t *et = (Ethernet_t *)xet;
659 
660 	memcpy (et->et_dest, addr, 6);
661 	memcpy (et->et_src, NetOurEther, 6);
662 	et->et_protlen = htons(prot);
663 }
664 
665 
666 void
667 NetSetIP(volatile uchar * xip, IPaddr_t dest, int dport, int sport, int len)
668 {
669 	volatile IP_t *ip = (IP_t *)xip;
670 
671 	/*
672 	 *	If the data is an odd number of bytes, zero the
673 	 *	byte after the last byte so that the checksum
674 	 *	will work.
675 	 */
676 	if (len & 1)
677 		xip[IP_HDR_SIZE + len] = 0;
678 
679 	/*
680 	 *	Construct an IP and UDP header.
681 			(need to set no fragment bit - XXX)
682 	 */
683 	ip->ip_hl_v  = 0x45;		/* IP_HDR_SIZE / 4 (not including UDP) */
684 	ip->ip_tos   = 0;
685 	ip->ip_len   = htons(IP_HDR_SIZE + len);
686 	ip->ip_id    = htons(NetIPID++);
687 	ip->ip_off   = htons(0x4000);	/* No fragmentation */
688 	ip->ip_ttl   = 255;
689 	ip->ip_p     = 17;		/* UDP */
690 	ip->ip_sum   = 0;
691 	NetCopyIP((void*)&ip->ip_src, &NetOurIP); /* already in network byte order */
692 	NetCopyIP((void*)&ip->ip_dst, &dest);	   /* - "" - */
693 	ip->udp_src  = htons(sport);
694 	ip->udp_dst  = htons(dport);
695 	ip->udp_len  = htons(8 + len);
696 	ip->udp_xsum = 0;
697 	ip->ip_sum   = ~NetCksum((uchar *)ip, IP_HDR_SIZE_NO_UDP / 2);
698 }
699 
700 void copy_filename (uchar *dst, uchar *src, int size)
701 {
702 	if (*src && (*src == '"')) {
703 		++src;
704 		--size;
705 	}
706 
707 	while ((--size > 0) && *src && (*src != '"')) {
708 		*dst++ = *src++;
709 	}
710 	*dst = '\0';
711 }
712 
713 #endif /* CFG_CMD_NET */
714 
715 void ip_to_string (IPaddr_t x, char *s)
716 {
717     x = ntohl(x);
718     sprintf (s,"%d.%d.%d.%d",
719     	(int)((x >> 24) & 0xff),
720 	(int)((x >> 16) & 0xff),
721 	(int)((x >>  8) & 0xff),
722 	(int)((x >>  0) & 0xff)
723     );
724 }
725 
726 void print_IPaddr (IPaddr_t x)
727 {
728     char tmp[16];
729 
730     ip_to_string(x, tmp);
731 
732     puts(tmp);
733 }
734 
735 IPaddr_t getenv_IPaddr (char *var)
736 {
737 	IPaddr_t addr;
738 	char *s, *e;
739 	int i;
740 
741 	s = getenv (var);
742 
743 	for (addr=0, i=0; i<4; ++i) {
744 		ulong val = s ? simple_strtoul(s, &e, 10) : 0;
745 		addr <<= 8;
746 		addr |= (val & 0xFF);
747 		if (s) {
748 			s = (*e) ? e+1 : e;
749 		}
750 	}
751 
752 	return (htonl(addr));
753 }
754