xref: /openbmc/u-boot/net/net.c (revision 3f82d89d)
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  * LINK_LOCAL:
27  *
28  *	Prerequisites:	- own ethernet address
29  *	We want:	- own IP address
30  *	Next step:	ARP
31  *
32  * RARP:
33  *
34  *	Prerequisites:	- own ethernet address
35  *	We want:	- own IP address
36  *			- TFTP server IP address
37  *	Next step:	ARP
38  *
39  * ARP:
40  *
41  *	Prerequisites:	- own ethernet address
42  *			- own IP address
43  *			- TFTP server IP address
44  *	We want:	- TFTP server ethernet address
45  *	Next step:	TFTP
46  *
47  * DHCP:
48  *
49  *     Prerequisites:	- own ethernet address
50  *     We want:		- IP, Netmask, ServerIP, Gateway IP
51  *			- bootfilename, lease time
52  *     Next step:	- TFTP
53  *
54  * TFTP:
55  *
56  *	Prerequisites:	- own ethernet address
57  *			- own IP address
58  *			- TFTP server IP address
59  *			- TFTP server ethernet address
60  *			- name of bootfile (if unknown, we use a default name
61  *			  derived from our own IP address)
62  *	We want:	- load the boot file
63  *	Next step:	none
64  *
65  * NFS:
66  *
67  *	Prerequisites:	- own ethernet address
68  *			- own IP address
69  *			- name of bootfile (if unknown, we use a default name
70  *			  derived from our own IP address)
71  *	We want:	- load the boot file
72  *	Next step:	none
73  *
74  * SNTP:
75  *
76  *	Prerequisites:	- own ethernet address
77  *			- own IP address
78  *	We want:	- network time
79  *	Next step:	none
80  */
81 
82 
83 #include <common.h>
84 #include <command.h>
85 #include <net.h>
86 #if defined(CONFIG_STATUS_LED)
87 #include <miiphy.h>
88 #include <status_led.h>
89 #endif
90 #include <watchdog.h>
91 #include <linux/compiler.h>
92 #include "arp.h"
93 #include "bootp.h"
94 #include "cdp.h"
95 #if defined(CONFIG_CMD_DNS)
96 #include "dns.h"
97 #endif
98 #include "link_local.h"
99 #include "nfs.h"
100 #include "ping.h"
101 #include "rarp.h"
102 #if defined(CONFIG_CMD_SNTP)
103 #include "sntp.h"
104 #endif
105 #include "tftp.h"
106 
107 DECLARE_GLOBAL_DATA_PTR;
108 
109 /** BOOTP EXTENTIONS **/
110 
111 /* Our subnet mask (0=unknown) */
112 IPaddr_t	NetOurSubnetMask;
113 /* Our gateways IP address */
114 IPaddr_t	NetOurGatewayIP;
115 /* Our DNS IP address */
116 IPaddr_t	NetOurDNSIP;
117 #if defined(CONFIG_BOOTP_DNS2)
118 /* Our 2nd DNS IP address */
119 IPaddr_t	NetOurDNS2IP;
120 #endif
121 /* Our NIS domain */
122 char		NetOurNISDomain[32] = {0,};
123 /* Our hostname */
124 char		NetOurHostName[32] = {0,};
125 /* Our bootpath */
126 char		NetOurRootPath[64] = {0,};
127 /* Our bootfile size in blocks */
128 ushort		NetBootFileSize;
129 
130 #ifdef CONFIG_MCAST_TFTP	/* Multicast TFTP */
131 IPaddr_t Mcast_addr;
132 #endif
133 
134 /** END OF BOOTP EXTENTIONS **/
135 
136 /* The actual transferred size of the bootfile (in bytes) */
137 ulong		NetBootFileXferSize;
138 /* Our ethernet address */
139 uchar		NetOurEther[6];
140 /* Boot server enet address */
141 uchar		NetServerEther[6];
142 /* Our IP addr (0 = unknown) */
143 IPaddr_t	NetOurIP;
144 /* Server IP addr (0 = unknown) */
145 IPaddr_t	NetServerIP;
146 /* Current receive packet */
147 uchar *NetRxPacket;
148 /* Current rx packet length */
149 int		NetRxPacketLen;
150 /* IP packet ID */
151 unsigned	NetIPID;
152 /* Ethernet bcast address */
153 uchar		NetBcastAddr[6] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
154 uchar		NetEtherNullAddr[6];
155 #ifdef CONFIG_API
156 void		(*push_packet)(void *, int len) = 0;
157 #endif
158 /* Network loop state */
159 enum net_loop_state net_state;
160 /* Tried all network devices */
161 int		NetRestartWrap;
162 /* Network loop restarted */
163 static int	NetRestarted;
164 /* At least one device configured */
165 static int	NetDevExists;
166 
167 /* XXX in both little & big endian machines 0xFFFF == ntohs(-1) */
168 /* default is without VLAN */
169 ushort		NetOurVLAN = 0xFFFF;
170 /* ditto */
171 ushort		NetOurNativeVLAN = 0xFFFF;
172 
173 /* Boot File name */
174 char		BootFile[128];
175 
176 #if defined(CONFIG_CMD_SNTP)
177 /* NTP server IP address */
178 IPaddr_t	NetNtpServerIP;
179 /* offset time from UTC */
180 int		NetTimeOffset;
181 #endif
182 
183 uchar PktBuf[(PKTBUFSRX+1) * PKTSIZE_ALIGN + PKTALIGN];
184 
185 /* Receive packet */
186 uchar *NetRxPackets[PKTBUFSRX];
187 
188 /* Current UDP RX packet handler */
189 static rxhand_f *udp_packet_handler;
190 /* Current ARP RX packet handler */
191 static rxhand_f *arp_packet_handler;
192 #ifdef CONFIG_CMD_TFTPPUT
193 /* Current ICMP rx handler */
194 static rxhand_icmp_f *packet_icmp_handler;
195 #endif
196 /* Current timeout handler */
197 static thand_f *timeHandler;
198 /* Time base value */
199 static ulong	timeStart;
200 /* Current timeout value */
201 static ulong	timeDelta;
202 /* THE transmit packet */
203 uchar *NetTxPacket;
204 
205 static int net_check_prereq(enum proto_t protocol);
206 
207 static int NetTryCount;
208 
209 /**********************************************************************/
210 
211 /*
212  * Check if autoload is enabled. If so, use either NFS or TFTP to download
213  * the boot file.
214  */
215 void net_auto_load(void)
216 {
217 	const char *s = getenv("autoload");
218 
219 	if (s != NULL) {
220 		if (*s == 'n') {
221 			/*
222 			 * Just use BOOTP/RARP to configure system;
223 			 * Do not use TFTP to load the bootfile.
224 			 */
225 			net_set_state(NETLOOP_SUCCESS);
226 			return;
227 		}
228 #if defined(CONFIG_CMD_NFS)
229 		if (strcmp(s, "NFS") == 0) {
230 			/*
231 			 * Use NFS to load the bootfile.
232 			 */
233 			NfsStart();
234 			return;
235 		}
236 #endif
237 	}
238 	TftpStart(TFTPGET);
239 }
240 
241 static void NetInitLoop(void)
242 {
243 	static int env_changed_id;
244 	int env_id = get_env_id();
245 
246 	/* update only when the environment has changed */
247 	if (env_changed_id != env_id) {
248 		NetOurIP = getenv_IPaddr("ipaddr");
249 		NetOurGatewayIP = getenv_IPaddr("gatewayip");
250 		NetOurSubnetMask = getenv_IPaddr("netmask");
251 		NetServerIP = getenv_IPaddr("serverip");
252 		NetOurNativeVLAN = getenv_VLAN("nvlan");
253 		NetOurVLAN = getenv_VLAN("vlan");
254 #if defined(CONFIG_CMD_DNS)
255 		NetOurDNSIP = getenv_IPaddr("dnsip");
256 #endif
257 		env_changed_id = env_id;
258 	}
259 
260 	return;
261 }
262 
263 static void net_clear_handlers(void)
264 {
265 	net_set_udp_handler(NULL);
266 	net_set_arp_handler(NULL);
267 	NetSetTimeout(0, NULL);
268 }
269 
270 static void net_cleanup_loop(void)
271 {
272 	net_clear_handlers();
273 }
274 
275 void net_init(void)
276 {
277 	static int first_call = 1;
278 
279 	if (first_call) {
280 		/*
281 		 *	Setup packet buffers, aligned correctly.
282 		 */
283 		int i;
284 
285 		NetTxPacket = &PktBuf[0] + (PKTALIGN - 1);
286 		NetTxPacket -= (ulong)NetTxPacket % PKTALIGN;
287 		for (i = 0; i < PKTBUFSRX; i++)
288 			NetRxPackets[i] = NetTxPacket + (i + 1) * PKTSIZE_ALIGN;
289 
290 		ArpInit();
291 		net_clear_handlers();
292 
293 		/* Only need to setup buffer pointers once. */
294 		first_call = 0;
295 	}
296 
297 	NetInitLoop();
298 }
299 
300 /**********************************************************************/
301 /*
302  *	Main network processing loop.
303  */
304 
305 int NetLoop(enum proto_t protocol)
306 {
307 	bd_t *bd = gd->bd;
308 	int ret = -1;
309 
310 	NetRestarted = 0;
311 	NetDevExists = 0;
312 	NetTryCount = 1;
313 	debug_cond(DEBUG_INT_STATE, "--- NetLoop Entry\n");
314 
315 	bootstage_mark_name(BOOTSTAGE_ID_ETH_START, "eth_start");
316 	net_init();
317 	eth_halt();
318 	eth_set_current();
319 	if (eth_init(bd) < 0) {
320 		eth_halt();
321 		return -1;
322 	}
323 
324 restart:
325 	memcpy(NetOurEther, eth_get_dev()->enetaddr, 6);
326 
327 	net_set_state(NETLOOP_CONTINUE);
328 
329 	/*
330 	 *	Start the ball rolling with the given start function.  From
331 	 *	here on, this code is a state machine driven by received
332 	 *	packets and timer events.
333 	 */
334 	debug_cond(DEBUG_INT_STATE, "--- NetLoop Init\n");
335 	NetInitLoop();
336 
337 	switch (net_check_prereq(protocol)) {
338 	case 1:
339 		/* network not configured */
340 		eth_halt();
341 		return -1;
342 
343 	case 2:
344 		/* network device not configured */
345 		break;
346 
347 	case 0:
348 		NetDevExists = 1;
349 		NetBootFileXferSize = 0;
350 		switch (protocol) {
351 		case TFTPGET:
352 #ifdef CONFIG_CMD_TFTPPUT
353 		case TFTPPUT:
354 #endif
355 			/* always use ARP to get server ethernet address */
356 			TftpStart(protocol);
357 			break;
358 #ifdef CONFIG_CMD_TFTPSRV
359 		case TFTPSRV:
360 			TftpStartServer();
361 			break;
362 #endif
363 #if defined(CONFIG_CMD_DHCP)
364 		case DHCP:
365 			BootpTry = 0;
366 			NetOurIP = 0;
367 			DhcpRequest();		/* Basically same as BOOTP */
368 			break;
369 #endif
370 
371 		case BOOTP:
372 			BootpTry = 0;
373 			NetOurIP = 0;
374 			BootpRequest();
375 			break;
376 
377 #if defined(CONFIG_CMD_RARP)
378 		case RARP:
379 			RarpTry = 0;
380 			NetOurIP = 0;
381 			RarpRequest();
382 			break;
383 #endif
384 #if defined(CONFIG_CMD_PING)
385 		case PING:
386 			ping_start();
387 			break;
388 #endif
389 #if defined(CONFIG_CMD_NFS)
390 		case NFS:
391 			NfsStart();
392 			break;
393 #endif
394 #if defined(CONFIG_CMD_CDP)
395 		case CDP:
396 			CDPStart();
397 			break;
398 #endif
399 #ifdef CONFIG_NETCONSOLE
400 		case NETCONS:
401 			NcStart();
402 			break;
403 #endif
404 #if defined(CONFIG_CMD_SNTP)
405 		case SNTP:
406 			SntpStart();
407 			break;
408 #endif
409 #if defined(CONFIG_CMD_DNS)
410 		case DNS:
411 			DnsStart();
412 			break;
413 #endif
414 #if defined(CONFIG_CMD_LINK_LOCAL)
415 		case LINKLOCAL:
416 			link_local_start();
417 			break;
418 #endif
419 		default:
420 			break;
421 		}
422 
423 		break;
424 	}
425 
426 #if defined(CONFIG_MII) || defined(CONFIG_CMD_MII)
427 #if	defined(CONFIG_SYS_FAULT_ECHO_LINK_DOWN)	&& \
428 	defined(CONFIG_STATUS_LED)			&& \
429 	defined(STATUS_LED_RED)
430 	/*
431 	 * Echo the inverted link state to the fault LED.
432 	 */
433 	if (miiphy_link(eth_get_dev()->name, CONFIG_SYS_FAULT_MII_ADDR))
434 		status_led_set(STATUS_LED_RED, STATUS_LED_OFF);
435 	else
436 		status_led_set(STATUS_LED_RED, STATUS_LED_ON);
437 #endif /* CONFIG_SYS_FAULT_ECHO_LINK_DOWN, ... */
438 #endif /* CONFIG_MII, ... */
439 
440 	/*
441 	 *	Main packet reception loop.  Loop receiving packets until
442 	 *	someone sets `net_state' to a state that terminates.
443 	 */
444 	for (;;) {
445 		WATCHDOG_RESET();
446 #ifdef CONFIG_SHOW_ACTIVITY
447 		show_activity(1);
448 #endif
449 		/*
450 		 *	Check the ethernet for a new packet.  The ethernet
451 		 *	receive routine will process it.
452 		 */
453 		eth_rx();
454 
455 		/*
456 		 *	Abort if ctrl-c was pressed.
457 		 */
458 		if (ctrlc()) {
459 			/* cancel any ARP that may not have completed */
460 			NetArpWaitPacketIP = 0;
461 
462 			net_cleanup_loop();
463 			eth_halt();
464 			puts("\nAbort\n");
465 			/* include a debug print as well incase the debug
466 			   messages are directed to stderr */
467 			debug_cond(DEBUG_INT_STATE, "--- NetLoop Abort!\n");
468 			goto done;
469 		}
470 
471 		ArpTimeoutCheck();
472 
473 		/*
474 		 *	Check for a timeout, and run the timeout handler
475 		 *	if we have one.
476 		 */
477 		if (timeHandler && ((get_timer(0) - timeStart) > timeDelta)) {
478 			thand_f *x;
479 
480 #if defined(CONFIG_MII) || defined(CONFIG_CMD_MII)
481 #if	defined(CONFIG_SYS_FAULT_ECHO_LINK_DOWN)	&& \
482 	defined(CONFIG_STATUS_LED)			&& \
483 	defined(STATUS_LED_RED)
484 			/*
485 			 * Echo the inverted link state to the fault LED.
486 			 */
487 			if (miiphy_link(eth_get_dev()->name,
488 				       CONFIG_SYS_FAULT_MII_ADDR)) {
489 				status_led_set(STATUS_LED_RED, STATUS_LED_OFF);
490 			} else {
491 				status_led_set(STATUS_LED_RED, STATUS_LED_ON);
492 			}
493 #endif /* CONFIG_SYS_FAULT_ECHO_LINK_DOWN, ... */
494 #endif /* CONFIG_MII, ... */
495 			debug_cond(DEBUG_INT_STATE, "--- NetLoop timeout\n");
496 			x = timeHandler;
497 			timeHandler = (thand_f *)0;
498 			(*x)();
499 		}
500 
501 
502 		switch (net_state) {
503 
504 		case NETLOOP_RESTART:
505 			NetRestarted = 1;
506 			goto restart;
507 
508 		case NETLOOP_SUCCESS:
509 			net_cleanup_loop();
510 			if (NetBootFileXferSize > 0) {
511 				char buf[20];
512 				printf("Bytes transferred = %ld (%lx hex)\n",
513 					NetBootFileXferSize,
514 					NetBootFileXferSize);
515 				sprintf(buf, "%lX", NetBootFileXferSize);
516 				setenv("filesize", buf);
517 
518 				sprintf(buf, "%lX", (unsigned long)load_addr);
519 				setenv("fileaddr", buf);
520 			}
521 			eth_halt();
522 			ret = NetBootFileXferSize;
523 			debug_cond(DEBUG_INT_STATE, "--- NetLoop Success!\n");
524 			goto done;
525 
526 		case NETLOOP_FAIL:
527 			net_cleanup_loop();
528 			debug_cond(DEBUG_INT_STATE, "--- NetLoop Fail!\n");
529 			goto done;
530 
531 		case NETLOOP_CONTINUE:
532 			continue;
533 		}
534 	}
535 
536 done:
537 #ifdef CONFIG_CMD_TFTPPUT
538 	/* Clear out the handlers */
539 	net_set_udp_handler(NULL);
540 	net_set_icmp_handler(NULL);
541 #endif
542 	return ret;
543 }
544 
545 /**********************************************************************/
546 
547 static void
548 startAgainTimeout(void)
549 {
550 	net_set_state(NETLOOP_RESTART);
551 }
552 
553 void NetStartAgain(void)
554 {
555 	char *nretry;
556 	int retry_forever = 0;
557 	unsigned long retrycnt = 0;
558 
559 	nretry = getenv("netretry");
560 	if (nretry) {
561 		if (!strcmp(nretry, "yes"))
562 			retry_forever = 1;
563 		else if (!strcmp(nretry, "no"))
564 			retrycnt = 0;
565 		else if (!strcmp(nretry, "once"))
566 			retrycnt = 1;
567 		else
568 			retrycnt = simple_strtoul(nretry, NULL, 0);
569 	} else
570 		retry_forever = 1;
571 
572 	if ((!retry_forever) && (NetTryCount >= retrycnt)) {
573 		eth_halt();
574 		net_set_state(NETLOOP_FAIL);
575 		return;
576 	}
577 
578 	NetTryCount++;
579 
580 	eth_halt();
581 #if !defined(CONFIG_NET_DO_NOT_TRY_ANOTHER)
582 	eth_try_another(!NetRestarted);
583 #endif
584 	eth_init(gd->bd);
585 	if (NetRestartWrap) {
586 		NetRestartWrap = 0;
587 		if (NetDevExists) {
588 			NetSetTimeout(10000UL, startAgainTimeout);
589 			net_set_udp_handler(NULL);
590 		} else {
591 			net_set_state(NETLOOP_FAIL);
592 		}
593 	} else {
594 		net_set_state(NETLOOP_RESTART);
595 	}
596 }
597 
598 /**********************************************************************/
599 /*
600  *	Miscelaneous bits.
601  */
602 
603 static void dummy_handler(uchar *pkt, unsigned dport,
604 			IPaddr_t sip, unsigned sport,
605 			unsigned len)
606 {
607 }
608 
609 rxhand_f *net_get_udp_handler(void)
610 {
611 	return udp_packet_handler;
612 }
613 
614 void net_set_udp_handler(rxhand_f *f)
615 {
616 	debug_cond(DEBUG_INT_STATE, "--- NetLoop UDP handler set (%p)\n", f);
617 	if (f == NULL)
618 		udp_packet_handler = dummy_handler;
619 	else
620 		udp_packet_handler = f;
621 }
622 
623 rxhand_f *net_get_arp_handler(void)
624 {
625 	return arp_packet_handler;
626 }
627 
628 void net_set_arp_handler(rxhand_f *f)
629 {
630 	debug_cond(DEBUG_INT_STATE, "--- NetLoop ARP handler set (%p)\n", f);
631 	if (f == NULL)
632 		arp_packet_handler = dummy_handler;
633 	else
634 		arp_packet_handler = f;
635 }
636 
637 #ifdef CONFIG_CMD_TFTPPUT
638 void net_set_icmp_handler(rxhand_icmp_f *f)
639 {
640 	packet_icmp_handler = f;
641 }
642 #endif
643 
644 void
645 NetSetTimeout(ulong iv, thand_f *f)
646 {
647 	if (iv == 0) {
648 		debug_cond(DEBUG_INT_STATE,
649 			"--- NetLoop timeout handler cancelled\n");
650 		timeHandler = (thand_f *)0;
651 	} else {
652 		debug_cond(DEBUG_INT_STATE,
653 			"--- NetLoop timeout handler set (%p)\n", f);
654 		timeHandler = f;
655 		timeStart = get_timer(0);
656 		timeDelta = iv;
657 	}
658 }
659 
660 int NetSendUDPPacket(uchar *ether, IPaddr_t dest, int dport, int sport,
661 		int payload_len)
662 {
663 	uchar *pkt;
664 	int eth_hdr_size;
665 	int pkt_hdr_size;
666 
667 	/* make sure the NetTxPacket is initialized (NetInit() was called) */
668 	assert(NetTxPacket != NULL);
669 	if (NetTxPacket == NULL)
670 		return -1;
671 
672 	/* convert to new style broadcast */
673 	if (dest == 0)
674 		dest = 0xFFFFFFFF;
675 
676 	/* if broadcast, make the ether address a broadcast and don't do ARP */
677 	if (dest == 0xFFFFFFFF)
678 		ether = NetBcastAddr;
679 
680 	pkt = (uchar *)NetTxPacket;
681 
682 	eth_hdr_size = NetSetEther(pkt, ether, PROT_IP);
683 	pkt += eth_hdr_size;
684 	net_set_udp_header(pkt, dest, dport, sport, payload_len);
685 	pkt_hdr_size = eth_hdr_size + IP_UDP_HDR_SIZE;
686 
687 	/* if MAC address was not discovered yet, do an ARP request */
688 	if (memcmp(ether, NetEtherNullAddr, 6) == 0) {
689 		debug_cond(DEBUG_DEV_PKT, "sending ARP for %pI4\n", &dest);
690 
691 		/* save the ip and eth addr for the packet to send after arp */
692 		NetArpWaitPacketIP = dest;
693 		NetArpWaitPacketMAC = ether;
694 
695 		/* size of the waiting packet */
696 		NetArpWaitTxPacketSize = pkt_hdr_size + payload_len;
697 
698 		/* and do the ARP request */
699 		NetArpWaitTry = 1;
700 		NetArpWaitTimerStart = get_timer(0);
701 		ArpRequest();
702 		return 1;	/* waiting */
703 	} else {
704 		debug_cond(DEBUG_DEV_PKT, "sending UDP to %pI4/%pM\n",
705 			&dest, ether);
706 		NetSendPacket(NetTxPacket, pkt_hdr_size + payload_len);
707 		return 0;	/* transmitted */
708 	}
709 }
710 
711 #ifdef CONFIG_IP_DEFRAG
712 /*
713  * This function collects fragments in a single packet, according
714  * to the algorithm in RFC815. It returns NULL or the pointer to
715  * a complete packet, in static storage
716  */
717 #ifndef CONFIG_NET_MAXDEFRAG
718 #define CONFIG_NET_MAXDEFRAG 16384
719 #endif
720 /*
721  * MAXDEFRAG, above, is chosen in the config file and  is real data
722  * so we need to add the NFS overhead, which is more than TFTP.
723  * To use sizeof in the internal unnamed structures, we need a real
724  * instance (can't do "sizeof(struct rpc_t.u.reply))", unfortunately).
725  * The compiler doesn't complain nor allocates the actual structure
726  */
727 static struct rpc_t rpc_specimen;
728 #define IP_PKTSIZE (CONFIG_NET_MAXDEFRAG + sizeof(rpc_specimen.u.reply))
729 
730 #define IP_MAXUDP (IP_PKTSIZE - IP_HDR_SIZE)
731 
732 /*
733  * this is the packet being assembled, either data or frag control.
734  * Fragments go by 8 bytes, so this union must be 8 bytes long
735  */
736 struct hole {
737 	/* first_byte is address of this structure */
738 	u16 last_byte;	/* last byte in this hole + 1 (begin of next hole) */
739 	u16 next_hole;	/* index of next (in 8-b blocks), 0 == none */
740 	u16 prev_hole;	/* index of prev, 0 == none */
741 	u16 unused;
742 };
743 
744 static struct ip_udp_hdr *__NetDefragment(struct ip_udp_hdr *ip, int *lenp)
745 {
746 	static uchar pkt_buff[IP_PKTSIZE] __aligned(PKTALIGN);
747 	static u16 first_hole, total_len;
748 	struct hole *payload, *thisfrag, *h, *newh;
749 	struct ip_udp_hdr *localip = (struct ip_udp_hdr *)pkt_buff;
750 	uchar *indata = (uchar *)ip;
751 	int offset8, start, len, done = 0;
752 	u16 ip_off = ntohs(ip->ip_off);
753 
754 	/* payload starts after IP header, this fragment is in there */
755 	payload = (struct hole *)(pkt_buff + IP_HDR_SIZE);
756 	offset8 =  (ip_off & IP_OFFS);
757 	thisfrag = payload + offset8;
758 	start = offset8 * 8;
759 	len = ntohs(ip->ip_len) - IP_HDR_SIZE;
760 
761 	if (start + len > IP_MAXUDP) /* fragment extends too far */
762 		return NULL;
763 
764 	if (!total_len || localip->ip_id != ip->ip_id) {
765 		/* new (or different) packet, reset structs */
766 		total_len = 0xffff;
767 		payload[0].last_byte = ~0;
768 		payload[0].next_hole = 0;
769 		payload[0].prev_hole = 0;
770 		first_hole = 0;
771 		/* any IP header will work, copy the first we received */
772 		memcpy(localip, ip, IP_HDR_SIZE);
773 	}
774 
775 	/*
776 	 * What follows is the reassembly algorithm. We use the payload
777 	 * array as a linked list of hole descriptors, as each hole starts
778 	 * at a multiple of 8 bytes. However, last byte can be whatever value,
779 	 * so it is represented as byte count, not as 8-byte blocks.
780 	 */
781 
782 	h = payload + first_hole;
783 	while (h->last_byte < start) {
784 		if (!h->next_hole) {
785 			/* no hole that far away */
786 			return NULL;
787 		}
788 		h = payload + h->next_hole;
789 	}
790 
791 	/* last fragment may be 1..7 bytes, the "+7" forces acceptance */
792 	if (offset8 + ((len + 7) / 8) <= h - payload) {
793 		/* no overlap with holes (dup fragment?) */
794 		return NULL;
795 	}
796 
797 	if (!(ip_off & IP_FLAGS_MFRAG)) {
798 		/* no more fragmentss: truncate this (last) hole */
799 		total_len = start + len;
800 		h->last_byte = start + len;
801 	}
802 
803 	/*
804 	 * There is some overlap: fix the hole list. This code doesn't
805 	 * deal with a fragment that overlaps with two different holes
806 	 * (thus being a superset of a previously-received fragment).
807 	 */
808 
809 	if ((h >= thisfrag) && (h->last_byte <= start + len)) {
810 		/* complete overlap with hole: remove hole */
811 		if (!h->prev_hole && !h->next_hole) {
812 			/* last remaining hole */
813 			done = 1;
814 		} else if (!h->prev_hole) {
815 			/* first hole */
816 			first_hole = h->next_hole;
817 			payload[h->next_hole].prev_hole = 0;
818 		} else if (!h->next_hole) {
819 			/* last hole */
820 			payload[h->prev_hole].next_hole = 0;
821 		} else {
822 			/* in the middle of the list */
823 			payload[h->next_hole].prev_hole = h->prev_hole;
824 			payload[h->prev_hole].next_hole = h->next_hole;
825 		}
826 
827 	} else if (h->last_byte <= start + len) {
828 		/* overlaps with final part of the hole: shorten this hole */
829 		h->last_byte = start;
830 
831 	} else if (h >= thisfrag) {
832 		/* overlaps with initial part of the hole: move this hole */
833 		newh = thisfrag + (len / 8);
834 		*newh = *h;
835 		h = newh;
836 		if (h->next_hole)
837 			payload[h->next_hole].prev_hole = (h - payload);
838 		if (h->prev_hole)
839 			payload[h->prev_hole].next_hole = (h - payload);
840 		else
841 			first_hole = (h - payload);
842 
843 	} else {
844 		/* fragment sits in the middle: split the hole */
845 		newh = thisfrag + (len / 8);
846 		*newh = *h;
847 		h->last_byte = start;
848 		h->next_hole = (newh - payload);
849 		newh->prev_hole = (h - payload);
850 		if (newh->next_hole)
851 			payload[newh->next_hole].prev_hole = (newh - payload);
852 	}
853 
854 	/* finally copy this fragment and possibly return whole packet */
855 	memcpy((uchar *)thisfrag, indata + IP_HDR_SIZE, len);
856 	if (!done)
857 		return NULL;
858 
859 	localip->ip_len = htons(total_len);
860 	*lenp = total_len + IP_HDR_SIZE;
861 	return localip;
862 }
863 
864 static inline struct ip_udp_hdr *NetDefragment(struct ip_udp_hdr *ip, int *lenp)
865 {
866 	u16 ip_off = ntohs(ip->ip_off);
867 	if (!(ip_off & (IP_OFFS | IP_FLAGS_MFRAG)))
868 		return ip; /* not a fragment */
869 	return __NetDefragment(ip, lenp);
870 }
871 
872 #else /* !CONFIG_IP_DEFRAG */
873 
874 static inline struct ip_udp_hdr *NetDefragment(struct ip_udp_hdr *ip, int *lenp)
875 {
876 	u16 ip_off = ntohs(ip->ip_off);
877 	if (!(ip_off & (IP_OFFS | IP_FLAGS_MFRAG)))
878 		return ip; /* not a fragment */
879 	return NULL;
880 }
881 #endif
882 
883 /**
884  * Receive an ICMP packet. We deal with REDIRECT and PING here, and silently
885  * drop others.
886  *
887  * @parma ip	IP packet containing the ICMP
888  */
889 static void receive_icmp(struct ip_udp_hdr *ip, int len,
890 			IPaddr_t src_ip, struct ethernet_hdr *et)
891 {
892 	struct icmp_hdr *icmph = (struct icmp_hdr *)&ip->udp_src;
893 
894 	switch (icmph->type) {
895 	case ICMP_REDIRECT:
896 		if (icmph->code != ICMP_REDIR_HOST)
897 			return;
898 		printf(" ICMP Host Redirect to %pI4 ",
899 			&icmph->un.gateway);
900 		break;
901 	default:
902 #if defined(CONFIG_CMD_PING)
903 		ping_receive(et, ip, len);
904 #endif
905 #ifdef CONFIG_CMD_TFTPPUT
906 		if (packet_icmp_handler)
907 			packet_icmp_handler(icmph->type, icmph->code,
908 				ntohs(ip->udp_dst), src_ip, ntohs(ip->udp_src),
909 				icmph->un.data, ntohs(ip->udp_len));
910 #endif
911 		break;
912 	}
913 }
914 
915 void
916 NetReceive(uchar *inpkt, int len)
917 {
918 	struct ethernet_hdr *et;
919 	struct ip_udp_hdr *ip;
920 	IPaddr_t dst_ip;
921 	IPaddr_t src_ip;
922 	int eth_proto;
923 #if defined(CONFIG_CMD_CDP)
924 	int iscdp;
925 #endif
926 	ushort cti = 0, vlanid = VLAN_NONE, myvlanid, mynvlanid;
927 
928 	debug_cond(DEBUG_NET_PKT, "packet received\n");
929 
930 	NetRxPacket = inpkt;
931 	NetRxPacketLen = len;
932 	et = (struct ethernet_hdr *)inpkt;
933 
934 	/* too small packet? */
935 	if (len < ETHER_HDR_SIZE)
936 		return;
937 
938 #ifdef CONFIG_API
939 	if (push_packet) {
940 		(*push_packet)(inpkt, len);
941 		return;
942 	}
943 #endif
944 
945 #if defined(CONFIG_CMD_CDP)
946 	/* keep track if packet is CDP */
947 	iscdp = is_cdp_packet(et->et_dest);
948 #endif
949 
950 	myvlanid = ntohs(NetOurVLAN);
951 	if (myvlanid == (ushort)-1)
952 		myvlanid = VLAN_NONE;
953 	mynvlanid = ntohs(NetOurNativeVLAN);
954 	if (mynvlanid == (ushort)-1)
955 		mynvlanid = VLAN_NONE;
956 
957 	eth_proto = ntohs(et->et_protlen);
958 
959 	if (eth_proto < 1514) {
960 		struct e802_hdr *et802 = (struct e802_hdr *)et;
961 		/*
962 		 *	Got a 802.2 packet.  Check the other protocol field.
963 		 *	XXX VLAN over 802.2+SNAP not implemented!
964 		 */
965 		eth_proto = ntohs(et802->et_prot);
966 
967 		ip = (struct ip_udp_hdr *)(inpkt + E802_HDR_SIZE);
968 		len -= E802_HDR_SIZE;
969 
970 	} else if (eth_proto != PROT_VLAN) {	/* normal packet */
971 		ip = (struct ip_udp_hdr *)(inpkt + ETHER_HDR_SIZE);
972 		len -= ETHER_HDR_SIZE;
973 
974 	} else {			/* VLAN packet */
975 		struct vlan_ethernet_hdr *vet =
976 			(struct vlan_ethernet_hdr *)et;
977 
978 		debug_cond(DEBUG_NET_PKT, "VLAN packet received\n");
979 
980 		/* too small packet? */
981 		if (len < VLAN_ETHER_HDR_SIZE)
982 			return;
983 
984 		/* if no VLAN active */
985 		if ((ntohs(NetOurVLAN) & VLAN_IDMASK) == VLAN_NONE
986 #if defined(CONFIG_CMD_CDP)
987 				&& iscdp == 0
988 #endif
989 				)
990 			return;
991 
992 		cti = ntohs(vet->vet_tag);
993 		vlanid = cti & VLAN_IDMASK;
994 		eth_proto = ntohs(vet->vet_type);
995 
996 		ip = (struct ip_udp_hdr *)(inpkt + VLAN_ETHER_HDR_SIZE);
997 		len -= VLAN_ETHER_HDR_SIZE;
998 	}
999 
1000 	debug_cond(DEBUG_NET_PKT, "Receive from protocol 0x%x\n", eth_proto);
1001 
1002 #if defined(CONFIG_CMD_CDP)
1003 	if (iscdp) {
1004 		cdp_receive((uchar *)ip, len);
1005 		return;
1006 	}
1007 #endif
1008 
1009 	if ((myvlanid & VLAN_IDMASK) != VLAN_NONE) {
1010 		if (vlanid == VLAN_NONE)
1011 			vlanid = (mynvlanid & VLAN_IDMASK);
1012 		/* not matched? */
1013 		if (vlanid != (myvlanid & VLAN_IDMASK))
1014 			return;
1015 	}
1016 
1017 	switch (eth_proto) {
1018 
1019 	case PROT_ARP:
1020 		ArpReceive(et, ip, len);
1021 		break;
1022 
1023 #ifdef CONFIG_CMD_RARP
1024 	case PROT_RARP:
1025 		rarp_receive(ip, len);
1026 		break;
1027 #endif
1028 	case PROT_IP:
1029 		debug_cond(DEBUG_NET_PKT, "Got IP\n");
1030 		/* Before we start poking the header, make sure it is there */
1031 		if (len < IP_UDP_HDR_SIZE) {
1032 			debug("len bad %d < %lu\n", len,
1033 				(ulong)IP_UDP_HDR_SIZE);
1034 			return;
1035 		}
1036 		/* Check the packet length */
1037 		if (len < ntohs(ip->ip_len)) {
1038 			debug("len bad %d < %d\n", len, ntohs(ip->ip_len));
1039 			return;
1040 		}
1041 		len = ntohs(ip->ip_len);
1042 		debug_cond(DEBUG_NET_PKT, "len=%d, v=%02x\n",
1043 			len, ip->ip_hl_v & 0xff);
1044 
1045 		/* Can't deal with anything except IPv4 */
1046 		if ((ip->ip_hl_v & 0xf0) != 0x40)
1047 			return;
1048 		/* Can't deal with IP options (headers != 20 bytes) */
1049 		if ((ip->ip_hl_v & 0x0f) > 0x05)
1050 			return;
1051 		/* Check the Checksum of the header */
1052 		if (!NetCksumOk((uchar *)ip, IP_HDR_SIZE / 2)) {
1053 			debug("checksum bad\n");
1054 			return;
1055 		}
1056 		/* If it is not for us, ignore it */
1057 		dst_ip = NetReadIP(&ip->ip_dst);
1058 		if (NetOurIP && dst_ip != NetOurIP && dst_ip != 0xFFFFFFFF) {
1059 #ifdef CONFIG_MCAST_TFTP
1060 			if (Mcast_addr != dst_ip)
1061 #endif
1062 				return;
1063 		}
1064 		/* Read source IP address for later use */
1065 		src_ip = NetReadIP(&ip->ip_src);
1066 		/*
1067 		 * The function returns the unchanged packet if it's not
1068 		 * a fragment, and either the complete packet or NULL if
1069 		 * it is a fragment (if !CONFIG_IP_DEFRAG, it returns NULL)
1070 		 */
1071 		ip = NetDefragment(ip, &len);
1072 		if (!ip)
1073 			return;
1074 		/*
1075 		 * watch for ICMP host redirects
1076 		 *
1077 		 * There is no real handler code (yet). We just watch
1078 		 * for ICMP host redirect messages. In case anybody
1079 		 * sees these messages: please contact me
1080 		 * (wd@denx.de), or - even better - send me the
1081 		 * necessary fixes :-)
1082 		 *
1083 		 * Note: in all cases where I have seen this so far
1084 		 * it was a problem with the router configuration,
1085 		 * for instance when a router was configured in the
1086 		 * BOOTP reply, but the TFTP server was on the same
1087 		 * subnet. So this is probably a warning that your
1088 		 * configuration might be wrong. But I'm not really
1089 		 * sure if there aren't any other situations.
1090 		 *
1091 		 * Simon Glass <sjg@chromium.org>: We get an ICMP when
1092 		 * we send a tftp packet to a dead connection, or when
1093 		 * there is no server at the other end.
1094 		 */
1095 		if (ip->ip_p == IPPROTO_ICMP) {
1096 			receive_icmp(ip, len, src_ip, et);
1097 			return;
1098 		} else if (ip->ip_p != IPPROTO_UDP) {	/* Only UDP packets */
1099 			return;
1100 		}
1101 
1102 		debug_cond(DEBUG_DEV_PKT,
1103 			"received UDP (to=%pI4, from=%pI4, len=%d)\n",
1104 			&dst_ip, &src_ip, len);
1105 
1106 #ifdef CONFIG_UDP_CHECKSUM
1107 		if (ip->udp_xsum != 0) {
1108 			ulong   xsum;
1109 			ushort *sumptr;
1110 			ushort  sumlen;
1111 
1112 			xsum  = ip->ip_p;
1113 			xsum += (ntohs(ip->udp_len));
1114 			xsum += (ntohl(ip->ip_src) >> 16) & 0x0000ffff;
1115 			xsum += (ntohl(ip->ip_src) >>  0) & 0x0000ffff;
1116 			xsum += (ntohl(ip->ip_dst) >> 16) & 0x0000ffff;
1117 			xsum += (ntohl(ip->ip_dst) >>  0) & 0x0000ffff;
1118 
1119 			sumlen = ntohs(ip->udp_len);
1120 			sumptr = (ushort *) &(ip->udp_src);
1121 
1122 			while (sumlen > 1) {
1123 				ushort sumdata;
1124 
1125 				sumdata = *sumptr++;
1126 				xsum += ntohs(sumdata);
1127 				sumlen -= 2;
1128 			}
1129 			if (sumlen > 0) {
1130 				ushort sumdata;
1131 
1132 				sumdata = *(unsigned char *) sumptr;
1133 				sumdata = (sumdata << 8) & 0xff00;
1134 				xsum += sumdata;
1135 			}
1136 			while ((xsum >> 16) != 0) {
1137 				xsum = (xsum & 0x0000ffff) +
1138 				       ((xsum >> 16) & 0x0000ffff);
1139 			}
1140 			if ((xsum != 0x00000000) && (xsum != 0x0000ffff)) {
1141 				printf(" UDP wrong checksum %08lx %08x\n",
1142 					xsum, ntohs(ip->udp_xsum));
1143 				return;
1144 			}
1145 		}
1146 #endif
1147 
1148 
1149 #ifdef CONFIG_NETCONSOLE
1150 		nc_input_packet((uchar *)ip + IP_UDP_HDR_SIZE,
1151 					ntohs(ip->udp_dst),
1152 					ntohs(ip->udp_src),
1153 					ntohs(ip->udp_len) - UDP_HDR_SIZE);
1154 #endif
1155 		/*
1156 		 *	IP header OK.  Pass the packet to the current handler.
1157 		 */
1158 		(*udp_packet_handler)((uchar *)ip + IP_UDP_HDR_SIZE,
1159 				ntohs(ip->udp_dst),
1160 				src_ip,
1161 				ntohs(ip->udp_src),
1162 				ntohs(ip->udp_len) - UDP_HDR_SIZE);
1163 		break;
1164 	}
1165 }
1166 
1167 
1168 /**********************************************************************/
1169 
1170 static int net_check_prereq(enum proto_t protocol)
1171 {
1172 	switch (protocol) {
1173 		/* Fall through */
1174 #if defined(CONFIG_CMD_PING)
1175 	case PING:
1176 		if (NetPingIP == 0) {
1177 			puts("*** ERROR: ping address not given\n");
1178 			return 1;
1179 		}
1180 		goto common;
1181 #endif
1182 #if defined(CONFIG_CMD_SNTP)
1183 	case SNTP:
1184 		if (NetNtpServerIP == 0) {
1185 			puts("*** ERROR: NTP server address not given\n");
1186 			return 1;
1187 		}
1188 		goto common;
1189 #endif
1190 #if defined(CONFIG_CMD_DNS)
1191 	case DNS:
1192 		if (NetOurDNSIP == 0) {
1193 			puts("*** ERROR: DNS server address not given\n");
1194 			return 1;
1195 		}
1196 		goto common;
1197 #endif
1198 #if defined(CONFIG_CMD_NFS)
1199 	case NFS:
1200 #endif
1201 	case TFTPGET:
1202 	case TFTPPUT:
1203 		if (NetServerIP == 0) {
1204 			puts("*** ERROR: `serverip' not set\n");
1205 			return 1;
1206 		}
1207 #if	defined(CONFIG_CMD_PING) || defined(CONFIG_CMD_SNTP) || \
1208 	defined(CONFIG_CMD_DNS)
1209 common:
1210 #endif
1211 		/* Fall through */
1212 
1213 	case NETCONS:
1214 	case TFTPSRV:
1215 		if (NetOurIP == 0) {
1216 			puts("*** ERROR: `ipaddr' not set\n");
1217 			return 1;
1218 		}
1219 		/* Fall through */
1220 
1221 #ifdef CONFIG_CMD_RARP
1222 	case RARP:
1223 #endif
1224 	case BOOTP:
1225 	case CDP:
1226 	case DHCP:
1227 	case LINKLOCAL:
1228 		if (memcmp(NetOurEther, "\0\0\0\0\0\0", 6) == 0) {
1229 			int num = eth_get_dev_index();
1230 
1231 			switch (num) {
1232 			case -1:
1233 				puts("*** ERROR: No ethernet found.\n");
1234 				return 1;
1235 			case 0:
1236 				puts("*** ERROR: `ethaddr' not set\n");
1237 				break;
1238 			default:
1239 				printf("*** ERROR: `eth%daddr' not set\n",
1240 					num);
1241 				break;
1242 			}
1243 
1244 			NetStartAgain();
1245 			return 2;
1246 		}
1247 		/* Fall through */
1248 	default:
1249 		return 0;
1250 	}
1251 	return 0;		/* OK */
1252 }
1253 /**********************************************************************/
1254 
1255 int
1256 NetCksumOk(uchar *ptr, int len)
1257 {
1258 	return !((NetCksum(ptr, len) + 1) & 0xfffe);
1259 }
1260 
1261 
1262 unsigned
1263 NetCksum(uchar *ptr, int len)
1264 {
1265 	ulong	xsum;
1266 	ushort *p = (ushort *)ptr;
1267 
1268 	xsum = 0;
1269 	while (len-- > 0)
1270 		xsum += *p++;
1271 	xsum = (xsum & 0xffff) + (xsum >> 16);
1272 	xsum = (xsum & 0xffff) + (xsum >> 16);
1273 	return xsum & 0xffff;
1274 }
1275 
1276 int
1277 NetEthHdrSize(void)
1278 {
1279 	ushort myvlanid;
1280 
1281 	myvlanid = ntohs(NetOurVLAN);
1282 	if (myvlanid == (ushort)-1)
1283 		myvlanid = VLAN_NONE;
1284 
1285 	return ((myvlanid & VLAN_IDMASK) == VLAN_NONE) ? ETHER_HDR_SIZE :
1286 		VLAN_ETHER_HDR_SIZE;
1287 }
1288 
1289 int
1290 NetSetEther(uchar *xet, uchar * addr, uint prot)
1291 {
1292 	struct ethernet_hdr *et = (struct ethernet_hdr *)xet;
1293 	ushort myvlanid;
1294 
1295 	myvlanid = ntohs(NetOurVLAN);
1296 	if (myvlanid == (ushort)-1)
1297 		myvlanid = VLAN_NONE;
1298 
1299 	memcpy(et->et_dest, addr, 6);
1300 	memcpy(et->et_src, NetOurEther, 6);
1301 	if ((myvlanid & VLAN_IDMASK) == VLAN_NONE) {
1302 		et->et_protlen = htons(prot);
1303 		return ETHER_HDR_SIZE;
1304 	} else {
1305 		struct vlan_ethernet_hdr *vet =
1306 			(struct vlan_ethernet_hdr *)xet;
1307 
1308 		vet->vet_vlan_type = htons(PROT_VLAN);
1309 		vet->vet_tag = htons((0 << 5) | (myvlanid & VLAN_IDMASK));
1310 		vet->vet_type = htons(prot);
1311 		return VLAN_ETHER_HDR_SIZE;
1312 	}
1313 }
1314 
1315 int net_update_ether(struct ethernet_hdr *et, uchar *addr, uint prot)
1316 {
1317 	ushort protlen;
1318 
1319 	memcpy(et->et_dest, addr, 6);
1320 	memcpy(et->et_src, NetOurEther, 6);
1321 	protlen = ntohs(et->et_protlen);
1322 	if (protlen == PROT_VLAN) {
1323 		struct vlan_ethernet_hdr *vet =
1324 			(struct vlan_ethernet_hdr *)et;
1325 		vet->vet_type = htons(prot);
1326 		return VLAN_ETHER_HDR_SIZE;
1327 	} else if (protlen > 1514) {
1328 		et->et_protlen = htons(prot);
1329 		return ETHER_HDR_SIZE;
1330 	} else {
1331 		/* 802.2 + SNAP */
1332 		struct e802_hdr *et802 = (struct e802_hdr *)et;
1333 		et802->et_prot = htons(prot);
1334 		return E802_HDR_SIZE;
1335 	}
1336 }
1337 
1338 void net_set_ip_header(uchar *pkt, IPaddr_t dest, IPaddr_t source)
1339 {
1340 	struct ip_udp_hdr *ip = (struct ip_udp_hdr *)pkt;
1341 
1342 	/*
1343 	 *	Construct an IP header.
1344 	 */
1345 	/* IP_HDR_SIZE / 4 (not including UDP) */
1346 	ip->ip_hl_v  = 0x45;
1347 	ip->ip_tos   = 0;
1348 	ip->ip_len   = htons(IP_HDR_SIZE);
1349 	ip->ip_id    = htons(NetIPID++);
1350 	ip->ip_off   = htons(IP_FLAGS_DFRAG);	/* Don't fragment */
1351 	ip->ip_ttl   = 255;
1352 	ip->ip_sum   = 0;
1353 	/* already in network byte order */
1354 	NetCopyIP((void *)&ip->ip_src, &source);
1355 	/* already in network byte order */
1356 	NetCopyIP((void *)&ip->ip_dst, &dest);
1357 }
1358 
1359 void net_set_udp_header(uchar *pkt, IPaddr_t dest, int dport, int sport,
1360 			int len)
1361 {
1362 	struct ip_udp_hdr *ip = (struct ip_udp_hdr *)pkt;
1363 
1364 	/*
1365 	 *	If the data is an odd number of bytes, zero the
1366 	 *	byte after the last byte so that the checksum
1367 	 *	will work.
1368 	 */
1369 	if (len & 1)
1370 		pkt[IP_UDP_HDR_SIZE + len] = 0;
1371 
1372 	net_set_ip_header(pkt, dest, NetOurIP);
1373 	ip->ip_len   = htons(IP_UDP_HDR_SIZE + len);
1374 	ip->ip_p     = IPPROTO_UDP;
1375 	ip->ip_sum   = ~NetCksum((uchar *)ip, IP_HDR_SIZE >> 1);
1376 
1377 	ip->udp_src  = htons(sport);
1378 	ip->udp_dst  = htons(dport);
1379 	ip->udp_len  = htons(UDP_HDR_SIZE + len);
1380 	ip->udp_xsum = 0;
1381 }
1382 
1383 void copy_filename(char *dst, const char *src, int size)
1384 {
1385 	if (*src && (*src == '"')) {
1386 		++src;
1387 		--size;
1388 	}
1389 
1390 	while ((--size > 0) && *src && (*src != '"'))
1391 		*dst++ = *src++;
1392 	*dst = '\0';
1393 }
1394 
1395 #if	defined(CONFIG_CMD_NFS)		|| \
1396 	defined(CONFIG_CMD_SNTP)	|| \
1397 	defined(CONFIG_CMD_DNS)
1398 /*
1399  * make port a little random (1024-17407)
1400  * This keeps the math somewhat trivial to compute, and seems to work with
1401  * all supported protocols/clients/servers
1402  */
1403 unsigned int random_port(void)
1404 {
1405 	return 1024 + (get_timer(0) % 0x4000);
1406 }
1407 #endif
1408 
1409 void ip_to_string(IPaddr_t x, char *s)
1410 {
1411 	x = ntohl(x);
1412 	sprintf(s, "%d.%d.%d.%d",
1413 		(int) ((x >> 24) & 0xff),
1414 		(int) ((x >> 16) & 0xff),
1415 		(int) ((x >> 8) & 0xff), (int) ((x >> 0) & 0xff)
1416 	);
1417 }
1418 
1419 void VLAN_to_string(ushort x, char *s)
1420 {
1421 	x = ntohs(x);
1422 
1423 	if (x == (ushort)-1)
1424 		x = VLAN_NONE;
1425 
1426 	if (x == VLAN_NONE)
1427 		strcpy(s, "none");
1428 	else
1429 		sprintf(s, "%d", x & VLAN_IDMASK);
1430 }
1431 
1432 ushort string_to_VLAN(const char *s)
1433 {
1434 	ushort id;
1435 
1436 	if (s == NULL)
1437 		return htons(VLAN_NONE);
1438 
1439 	if (*s < '0' || *s > '9')
1440 		id = VLAN_NONE;
1441 	else
1442 		id = (ushort)simple_strtoul(s, NULL, 10);
1443 
1444 	return htons(id);
1445 }
1446 
1447 ushort getenv_VLAN(char *var)
1448 {
1449 	return string_to_VLAN(getenv(var));
1450 }
1451