xref: /rk3399_rockchip-uboot/net/net.c (revision cb1c991120983b2b2690564eb6e9d3bfd1c6ae7e)
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  * NFS:
60  *
61  *	Prerequisites:	- own ethernet address
62  *			- own IP address
63  *			- name of bootfile (if unknown, we use a default name
64  *			  derived from our own IP address)
65  *	We want:	- load the boot file
66  *	Next step:	none
67  *
68  * SNTP:
69  *
70  *	Prerequisites:	- own ethernet address
71  *			- own IP address
72  *	We want:	- network time
73  *	Next step:	none
74  */
75 
76 
77 #include <common.h>
78 #include <command.h>
79 #include <net.h>
80 #if defined(CONFIG_STATUS_LED)
81 #include <miiphy.h>
82 #include <status_led.h>
83 #endif
84 #include <watchdog.h>
85 #include <linux/compiler.h>
86 #include "arp.h"
87 #include "bootp.h"
88 #include "cdp.h"
89 #if defined(CONFIG_CMD_DNS)
90 #include "dns.h"
91 #endif
92 #include "nfs.h"
93 #include "ping.h"
94 #include "rarp.h"
95 #if defined(CONFIG_CMD_SNTP)
96 #include "sntp.h"
97 #endif
98 #include "tftp.h"
99 
100 DECLARE_GLOBAL_DATA_PTR;
101 
102 /** BOOTP EXTENTIONS **/
103 
104 /* Our subnet mask (0=unknown) */
105 IPaddr_t	NetOurSubnetMask;
106 /* Our gateways IP address */
107 IPaddr_t	NetOurGatewayIP;
108 /* Our DNS IP address */
109 IPaddr_t	NetOurDNSIP;
110 #if defined(CONFIG_BOOTP_DNS2)
111 /* Our 2nd DNS IP address */
112 IPaddr_t	NetOurDNS2IP;
113 #endif
114 /* Our NIS domain */
115 char		NetOurNISDomain[32] = {0,};
116 /* Our hostname */
117 char		NetOurHostName[32] = {0,};
118 /* Our bootpath */
119 char		NetOurRootPath[64] = {0,};
120 /* Our bootfile size in blocks */
121 ushort		NetBootFileSize;
122 
123 #ifdef CONFIG_MCAST_TFTP	/* Multicast TFTP */
124 IPaddr_t Mcast_addr;
125 #endif
126 
127 /** END OF BOOTP EXTENTIONS **/
128 
129 /* The actual transferred size of the bootfile (in bytes) */
130 ulong		NetBootFileXferSize;
131 /* Our ethernet address */
132 uchar		NetOurEther[6];
133 /* Boot server enet address */
134 uchar		NetServerEther[6];
135 /* Our IP addr (0 = unknown) */
136 IPaddr_t	NetOurIP;
137 /* Server IP addr (0 = unknown) */
138 IPaddr_t	NetServerIP;
139 /* Current receive packet */
140 uchar *NetRxPacket;
141 /* Current rx packet length */
142 int		NetRxPacketLen;
143 /* IP packet ID */
144 unsigned	NetIPID;
145 /* Ethernet bcast address */
146 uchar		NetBcastAddr[6] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
147 uchar		NetEtherNullAddr[6];
148 #ifdef CONFIG_API
149 void		(*push_packet)(void *, int len) = 0;
150 #endif
151 /* Network loop state */
152 enum net_loop_state net_state;
153 /* Tried all network devices */
154 int		NetRestartWrap;
155 /* Network loop restarted */
156 static int	NetRestarted;
157 /* At least one device configured */
158 static int	NetDevExists;
159 
160 /* XXX in both little & big endian machines 0xFFFF == ntohs(-1) */
161 /* default is without VLAN */
162 ushort		NetOurVLAN = 0xFFFF;
163 /* ditto */
164 ushort		NetOurNativeVLAN = 0xFFFF;
165 
166 /* Boot File name */
167 char		BootFile[128];
168 
169 #if defined(CONFIG_CMD_SNTP)
170 /* NTP server IP address */
171 IPaddr_t	NetNtpServerIP;
172 /* offset time from UTC */
173 int		NetTimeOffset;
174 #endif
175 
176 uchar PktBuf[(PKTBUFSRX+1) * PKTSIZE_ALIGN + PKTALIGN];
177 
178 /* Receive packet */
179 uchar *NetRxPackets[PKTBUFSRX];
180 
181 /* Current UDP RX packet handler */
182 static rxhand_f *udp_packet_handler;
183 /* Current ARP RX packet handler */
184 static rxhand_f *arp_packet_handler;
185 #ifdef CONFIG_CMD_TFTPPUT
186 /* Current ICMP rx handler */
187 static rxhand_icmp_f *packet_icmp_handler;
188 #endif
189 /* Current timeout handler */
190 static thand_f *timeHandler;
191 /* Time base value */
192 static ulong	timeStart;
193 /* Current timeout value */
194 static ulong	timeDelta;
195 /* THE transmit packet */
196 uchar *NetTxPacket;
197 
198 static int net_check_prereq(enum proto_t protocol);
199 
200 static int NetTryCount;
201 
202 /**********************************************************************/
203 
204 /*
205  * Check if autoload is enabled. If so, use either NFS or TFTP to download
206  * the boot file.
207  */
208 void net_auto_load(void)
209 {
210 	const char *s = getenv("autoload");
211 
212 	if (s != NULL) {
213 		if (*s == 'n') {
214 			/*
215 			 * Just use BOOTP/RARP to configure system;
216 			 * Do not use TFTP to load the bootfile.
217 			 */
218 			net_set_state(NETLOOP_SUCCESS);
219 			return;
220 		}
221 #if defined(CONFIG_CMD_NFS)
222 		if (strcmp(s, "NFS") == 0) {
223 			/*
224 			 * Use NFS to load the bootfile.
225 			 */
226 			NfsStart();
227 			return;
228 		}
229 #endif
230 	}
231 	TftpStart(TFTPGET);
232 }
233 
234 static void NetInitLoop(void)
235 {
236 	static int env_changed_id;
237 	int env_id = get_env_id();
238 
239 	/* update only when the environment has changed */
240 	if (env_changed_id != env_id) {
241 		NetOurIP = getenv_IPaddr("ipaddr");
242 		NetOurGatewayIP = getenv_IPaddr("gatewayip");
243 		NetOurSubnetMask = getenv_IPaddr("netmask");
244 		NetServerIP = getenv_IPaddr("serverip");
245 		NetOurNativeVLAN = getenv_VLAN("nvlan");
246 		NetOurVLAN = getenv_VLAN("vlan");
247 #if defined(CONFIG_CMD_DNS)
248 		NetOurDNSIP = getenv_IPaddr("dnsip");
249 #endif
250 		env_changed_id = env_id;
251 	}
252 
253 	return;
254 }
255 
256 static void net_clear_handlers(void)
257 {
258 	net_set_udp_handler(NULL);
259 	net_set_arp_handler(NULL);
260 	NetSetTimeout(0, NULL);
261 }
262 
263 static void net_cleanup_loop(void)
264 {
265 	net_clear_handlers();
266 }
267 
268 /**********************************************************************/
269 /*
270  *	Main network processing loop.
271  */
272 
273 int NetLoop(enum proto_t protocol)
274 {
275 	int	i;
276 	bd_t *bd = gd->bd;
277 	int ret = -1;
278 
279 	NetRestarted = 0;
280 	NetDevExists = 0;
281 
282 	NetTxPacket = NULL;
283 	NetTryCount = 1;
284 
285 	ArpInit();
286 	net_clear_handlers();
287 
288 	/*
289 	 *	Setup packet buffers, aligned correctly.
290 	 */
291 	NetTxPacket = &PktBuf[0] + (PKTALIGN - 1);
292 	NetTxPacket -= (ulong)NetTxPacket % PKTALIGN;
293 	for (i = 0; i < PKTBUFSRX; i++)
294 		NetRxPackets[i] = NetTxPacket + (i+1)*PKTSIZE_ALIGN;
295 
296 	bootstage_mark_name(BOOTSTAGE_ID_ETH_START, "eth_start");
297 	eth_halt();
298 	eth_set_current();
299 	if (eth_init(bd) < 0) {
300 		eth_halt();
301 		return -1;
302 	}
303 
304 restart:
305 	memcpy(NetOurEther, eth_get_dev()->enetaddr, 6);
306 
307 	net_set_state(NETLOOP_CONTINUE);
308 
309 	/*
310 	 *	Start the ball rolling with the given start function.  From
311 	 *	here on, this code is a state machine driven by received
312 	 *	packets and timer events.
313 	 */
314 	NetInitLoop();
315 
316 	switch (net_check_prereq(protocol)) {
317 	case 1:
318 		/* network not configured */
319 		eth_halt();
320 		return -1;
321 
322 	case 2:
323 		/* network device not configured */
324 		break;
325 
326 	case 0:
327 		NetDevExists = 1;
328 		NetBootFileXferSize = 0;
329 		switch (protocol) {
330 		case TFTPGET:
331 #ifdef CONFIG_CMD_TFTPPUT
332 		case TFTPPUT:
333 #endif
334 			/* always use ARP to get server ethernet address */
335 			TftpStart(protocol);
336 			break;
337 #ifdef CONFIG_CMD_TFTPSRV
338 		case TFTPSRV:
339 			TftpStartServer();
340 			break;
341 #endif
342 #if defined(CONFIG_CMD_DHCP)
343 		case DHCP:
344 			BootpTry = 0;
345 			NetOurIP = 0;
346 			DhcpRequest();		/* Basically same as BOOTP */
347 			break;
348 #endif
349 
350 		case BOOTP:
351 			BootpTry = 0;
352 			NetOurIP = 0;
353 			BootpRequest();
354 			break;
355 
356 #if defined(CONFIG_CMD_RARP)
357 		case RARP:
358 			RarpTry = 0;
359 			NetOurIP = 0;
360 			RarpRequest();
361 			break;
362 #endif
363 #if defined(CONFIG_CMD_PING)
364 		case PING:
365 			ping_start();
366 			break;
367 #endif
368 #if defined(CONFIG_CMD_NFS)
369 		case NFS:
370 			NfsStart();
371 			break;
372 #endif
373 #if defined(CONFIG_CMD_CDP)
374 		case CDP:
375 			CDPStart();
376 			break;
377 #endif
378 #ifdef CONFIG_NETCONSOLE
379 		case NETCONS:
380 			NcStart();
381 			break;
382 #endif
383 #if defined(CONFIG_CMD_SNTP)
384 		case SNTP:
385 			SntpStart();
386 			break;
387 #endif
388 #if defined(CONFIG_CMD_DNS)
389 		case DNS:
390 			DnsStart();
391 			break;
392 #endif
393 		default:
394 			break;
395 		}
396 
397 		break;
398 	}
399 
400 #if defined(CONFIG_MII) || defined(CONFIG_CMD_MII)
401 #if	defined(CONFIG_SYS_FAULT_ECHO_LINK_DOWN)	&& \
402 	defined(CONFIG_STATUS_LED)			&& \
403 	defined(STATUS_LED_RED)
404 	/*
405 	 * Echo the inverted link state to the fault LED.
406 	 */
407 	if (miiphy_link(eth_get_dev()->name, CONFIG_SYS_FAULT_MII_ADDR))
408 		status_led_set(STATUS_LED_RED, STATUS_LED_OFF);
409 	else
410 		status_led_set(STATUS_LED_RED, STATUS_LED_ON);
411 #endif /* CONFIG_SYS_FAULT_ECHO_LINK_DOWN, ... */
412 #endif /* CONFIG_MII, ... */
413 
414 	/*
415 	 *	Main packet reception loop.  Loop receiving packets until
416 	 *	someone sets `net_state' to a state that terminates.
417 	 */
418 	for (;;) {
419 		WATCHDOG_RESET();
420 #ifdef CONFIG_SHOW_ACTIVITY
421 		show_activity(1);
422 #endif
423 		/*
424 		 *	Check the ethernet for a new packet.  The ethernet
425 		 *	receive routine will process it.
426 		 */
427 		eth_rx();
428 
429 		/*
430 		 *	Abort if ctrl-c was pressed.
431 		 */
432 		if (ctrlc()) {
433 			net_cleanup_loop();
434 			eth_halt();
435 			puts("\nAbort\n");
436 			goto done;
437 		}
438 
439 		ArpTimeoutCheck();
440 
441 		/*
442 		 *	Check for a timeout, and run the timeout handler
443 		 *	if we have one.
444 		 */
445 		if (timeHandler && ((get_timer(0) - timeStart) > timeDelta)) {
446 			thand_f *x;
447 
448 #if defined(CONFIG_MII) || defined(CONFIG_CMD_MII)
449 #if	defined(CONFIG_SYS_FAULT_ECHO_LINK_DOWN)	&& \
450 	defined(CONFIG_STATUS_LED)			&& \
451 	defined(STATUS_LED_RED)
452 			/*
453 			 * Echo the inverted link state to the fault LED.
454 			 */
455 			if (miiphy_link(eth_get_dev()->name,
456 				       CONFIG_SYS_FAULT_MII_ADDR)) {
457 				status_led_set(STATUS_LED_RED, STATUS_LED_OFF);
458 			} else {
459 				status_led_set(STATUS_LED_RED, STATUS_LED_ON);
460 			}
461 #endif /* CONFIG_SYS_FAULT_ECHO_LINK_DOWN, ... */
462 #endif /* CONFIG_MII, ... */
463 			x = timeHandler;
464 			timeHandler = (thand_f *)0;
465 			(*x)();
466 		}
467 
468 
469 		switch (net_state) {
470 
471 		case NETLOOP_RESTART:
472 			NetRestarted = 1;
473 			goto restart;
474 
475 		case NETLOOP_SUCCESS:
476 			net_cleanup_loop();
477 			if (NetBootFileXferSize > 0) {
478 				char buf[20];
479 				printf("Bytes transferred = %ld (%lx hex)\n",
480 					NetBootFileXferSize,
481 					NetBootFileXferSize);
482 				sprintf(buf, "%lX", NetBootFileXferSize);
483 				setenv("filesize", buf);
484 
485 				sprintf(buf, "%lX", (unsigned long)load_addr);
486 				setenv("fileaddr", buf);
487 			}
488 			eth_halt();
489 			ret = NetBootFileXferSize;
490 			goto done;
491 
492 		case NETLOOP_FAIL:
493 			net_cleanup_loop();
494 			goto done;
495 
496 		case NETLOOP_CONTINUE:
497 			continue;
498 		}
499 	}
500 
501 done:
502 #ifdef CONFIG_CMD_TFTPPUT
503 	/* Clear out the handlers */
504 	net_set_udp_handler(NULL);
505 	net_set_icmp_handler(NULL);
506 #endif
507 	return ret;
508 }
509 
510 /**********************************************************************/
511 
512 static void
513 startAgainTimeout(void)
514 {
515 	net_set_state(NETLOOP_RESTART);
516 }
517 
518 void NetStartAgain(void)
519 {
520 	char *nretry;
521 	int retry_forever = 0;
522 	unsigned long retrycnt = 0;
523 
524 	nretry = getenv("netretry");
525 	if (nretry) {
526 		if (!strcmp(nretry, "yes"))
527 			retry_forever = 1;
528 		else if (!strcmp(nretry, "no"))
529 			retrycnt = 0;
530 		else if (!strcmp(nretry, "once"))
531 			retrycnt = 1;
532 		else
533 			retrycnt = simple_strtoul(nretry, NULL, 0);
534 	} else
535 		retry_forever = 1;
536 
537 	if ((!retry_forever) && (NetTryCount >= retrycnt)) {
538 		eth_halt();
539 		net_set_state(NETLOOP_FAIL);
540 		return;
541 	}
542 
543 	NetTryCount++;
544 
545 	eth_halt();
546 #if !defined(CONFIG_NET_DO_NOT_TRY_ANOTHER)
547 	eth_try_another(!NetRestarted);
548 #endif
549 	eth_init(gd->bd);
550 	if (NetRestartWrap) {
551 		NetRestartWrap = 0;
552 		if (NetDevExists) {
553 			NetSetTimeout(10000UL, startAgainTimeout);
554 			net_set_udp_handler(NULL);
555 		} else {
556 			net_set_state(NETLOOP_FAIL);
557 		}
558 	} else {
559 		net_set_state(NETLOOP_RESTART);
560 	}
561 }
562 
563 /**********************************************************************/
564 /*
565  *	Miscelaneous bits.
566  */
567 
568 static void dummy_handler(uchar *pkt, unsigned dport,
569 			IPaddr_t sip, unsigned sport,
570 			unsigned len)
571 {
572 }
573 
574 rxhand_f *net_get_udp_handler(void)
575 {
576 	return udp_packet_handler;
577 }
578 
579 void net_set_udp_handler(rxhand_f *f)
580 {
581 	if (f == NULL)
582 		udp_packet_handler = dummy_handler;
583 	else
584 		udp_packet_handler = f;
585 }
586 
587 rxhand_f *net_get_arp_handler(void)
588 {
589 	return arp_packet_handler;
590 }
591 
592 void net_set_arp_handler(rxhand_f *f)
593 {
594 	if (f == NULL)
595 		arp_packet_handler = dummy_handler;
596 	else
597 		arp_packet_handler = f;
598 }
599 
600 #ifdef CONFIG_CMD_TFTPPUT
601 void net_set_icmp_handler(rxhand_icmp_f *f)
602 {
603 	packet_icmp_handler = f;
604 }
605 #endif
606 
607 void
608 NetSetTimeout(ulong iv, thand_f *f)
609 {
610 	if (iv == 0) {
611 		timeHandler = (thand_f *)0;
612 	} else {
613 		timeHandler = f;
614 		timeStart = get_timer(0);
615 		timeDelta = iv;
616 	}
617 }
618 
619 int NetSendUDPPacket(uchar *ether, IPaddr_t dest, int dport, int sport,
620 		int payload_len)
621 {
622 	uchar *pkt;
623 	int need_arp = 0;
624 	int eth_hdr_size;
625 	int pkt_hdr_size;
626 
627 	/* convert to new style broadcast */
628 	if (dest == 0)
629 		dest = 0xFFFFFFFF;
630 
631 	/* if broadcast, make the ether address a broadcast and don't do ARP */
632 	if (dest == 0xFFFFFFFF)
633 		ether = NetBcastAddr;
634 
635 	/*
636 	 * if MAC address was not discovered yet, save the packet and do
637 	 * an ARP request
638 	 */
639 	if (memcmp(ether, NetEtherNullAddr, 6) == 0) {
640 		need_arp = 1;
641 		pkt = NetArpWaitTxPacket;
642 	} else
643 		pkt = (uchar *)NetTxPacket;
644 
645 	eth_hdr_size = NetSetEther(pkt, ether, PROT_IP);
646 	pkt += eth_hdr_size;
647 	net_set_udp_header(pkt, dest, dport, sport, payload_len);
648 	pkt_hdr_size = eth_hdr_size + IP_UDP_HDR_SIZE;
649 
650 	if (need_arp) {
651 		debug("sending ARP for %pI4\n", &dest);
652 
653 		/* save the ip and eth addr for the packet to send after arp */
654 		NetArpWaitPacketIP = dest;
655 		NetArpWaitPacketMAC = ether;
656 
657 		/*
658 		 * Copy the packet data from the NetTxPacket into the
659 		 *   NetArpWaitTxPacket to send after arp
660 		 */
661 		memcpy(pkt + IP_UDP_HDR_SIZE, (uchar *)NetTxPacket +
662 			pkt_hdr_size, payload_len);
663 
664 		/* size of the waiting packet */
665 		NetArpWaitTxPacketSize = pkt_hdr_size + payload_len;
666 
667 		/* and do the ARP request */
668 		NetArpWaitTry = 1;
669 		NetArpWaitTimerStart = get_timer(0);
670 		ArpRequest();
671 		return 1;	/* waiting */
672 	} else {
673 		debug("sending UDP to %pI4/%pM\n", &dest, ether);
674 		NetSendPacket(NetTxPacket, pkt_hdr_size + payload_len);
675 		return 0;	/* transmitted */
676 	}
677 }
678 
679 #ifdef CONFIG_IP_DEFRAG
680 /*
681  * This function collects fragments in a single packet, according
682  * to the algorithm in RFC815. It returns NULL or the pointer to
683  * a complete packet, in static storage
684  */
685 #ifndef CONFIG_NET_MAXDEFRAG
686 #define CONFIG_NET_MAXDEFRAG 16384
687 #endif
688 /*
689  * MAXDEFRAG, above, is chosen in the config file and  is real data
690  * so we need to add the NFS overhead, which is more than TFTP.
691  * To use sizeof in the internal unnamed structures, we need a real
692  * instance (can't do "sizeof(struct rpc_t.u.reply))", unfortunately).
693  * The compiler doesn't complain nor allocates the actual structure
694  */
695 static struct rpc_t rpc_specimen;
696 #define IP_PKTSIZE (CONFIG_NET_MAXDEFRAG + sizeof(rpc_specimen.u.reply))
697 
698 #define IP_MAXUDP (IP_PKTSIZE - IP_HDR_SIZE)
699 
700 /*
701  * this is the packet being assembled, either data or frag control.
702  * Fragments go by 8 bytes, so this union must be 8 bytes long
703  */
704 struct hole {
705 	/* first_byte is address of this structure */
706 	u16 last_byte;	/* last byte in this hole + 1 (begin of next hole) */
707 	u16 next_hole;	/* index of next (in 8-b blocks), 0 == none */
708 	u16 prev_hole;	/* index of prev, 0 == none */
709 	u16 unused;
710 };
711 
712 static struct ip_udp_hdr *__NetDefragment(struct ip_udp_hdr *ip, int *lenp)
713 {
714 	static uchar pkt_buff[IP_PKTSIZE] __aligned(PKTALIGN);
715 	static u16 first_hole, total_len;
716 	struct hole *payload, *thisfrag, *h, *newh;
717 	struct ip_udp_hdr *localip = (struct ip_udp_hdr *)pkt_buff;
718 	uchar *indata = (uchar *)ip;
719 	int offset8, start, len, done = 0;
720 	u16 ip_off = ntohs(ip->ip_off);
721 
722 	/* payload starts after IP header, this fragment is in there */
723 	payload = (struct hole *)(pkt_buff + IP_HDR_SIZE);
724 	offset8 =  (ip_off & IP_OFFS);
725 	thisfrag = payload + offset8;
726 	start = offset8 * 8;
727 	len = ntohs(ip->ip_len) - IP_HDR_SIZE;
728 
729 	if (start + len > IP_MAXUDP) /* fragment extends too far */
730 		return NULL;
731 
732 	if (!total_len || localip->ip_id != ip->ip_id) {
733 		/* new (or different) packet, reset structs */
734 		total_len = 0xffff;
735 		payload[0].last_byte = ~0;
736 		payload[0].next_hole = 0;
737 		payload[0].prev_hole = 0;
738 		first_hole = 0;
739 		/* any IP header will work, copy the first we received */
740 		memcpy(localip, ip, IP_HDR_SIZE);
741 	}
742 
743 	/*
744 	 * What follows is the reassembly algorithm. We use the payload
745 	 * array as a linked list of hole descriptors, as each hole starts
746 	 * at a multiple of 8 bytes. However, last byte can be whatever value,
747 	 * so it is represented as byte count, not as 8-byte blocks.
748 	 */
749 
750 	h = payload + first_hole;
751 	while (h->last_byte < start) {
752 		if (!h->next_hole) {
753 			/* no hole that far away */
754 			return NULL;
755 		}
756 		h = payload + h->next_hole;
757 	}
758 
759 	/* last fragment may be 1..7 bytes, the "+7" forces acceptance */
760 	if (offset8 + ((len + 7) / 8) <= h - payload) {
761 		/* no overlap with holes (dup fragment?) */
762 		return NULL;
763 	}
764 
765 	if (!(ip_off & IP_FLAGS_MFRAG)) {
766 		/* no more fragmentss: truncate this (last) hole */
767 		total_len = start + len;
768 		h->last_byte = start + len;
769 	}
770 
771 	/*
772 	 * There is some overlap: fix the hole list. This code doesn't
773 	 * deal with a fragment that overlaps with two different holes
774 	 * (thus being a superset of a previously-received fragment).
775 	 */
776 
777 	if ((h >= thisfrag) && (h->last_byte <= start + len)) {
778 		/* complete overlap with hole: remove hole */
779 		if (!h->prev_hole && !h->next_hole) {
780 			/* last remaining hole */
781 			done = 1;
782 		} else if (!h->prev_hole) {
783 			/* first hole */
784 			first_hole = h->next_hole;
785 			payload[h->next_hole].prev_hole = 0;
786 		} else if (!h->next_hole) {
787 			/* last hole */
788 			payload[h->prev_hole].next_hole = 0;
789 		} else {
790 			/* in the middle of the list */
791 			payload[h->next_hole].prev_hole = h->prev_hole;
792 			payload[h->prev_hole].next_hole = h->next_hole;
793 		}
794 
795 	} else if (h->last_byte <= start + len) {
796 		/* overlaps with final part of the hole: shorten this hole */
797 		h->last_byte = start;
798 
799 	} else if (h >= thisfrag) {
800 		/* overlaps with initial part of the hole: move this hole */
801 		newh = thisfrag + (len / 8);
802 		*newh = *h;
803 		h = newh;
804 		if (h->next_hole)
805 			payload[h->next_hole].prev_hole = (h - payload);
806 		if (h->prev_hole)
807 			payload[h->prev_hole].next_hole = (h - payload);
808 		else
809 			first_hole = (h - payload);
810 
811 	} else {
812 		/* fragment sits in the middle: split the hole */
813 		newh = thisfrag + (len / 8);
814 		*newh = *h;
815 		h->last_byte = start;
816 		h->next_hole = (newh - payload);
817 		newh->prev_hole = (h - payload);
818 		if (newh->next_hole)
819 			payload[newh->next_hole].prev_hole = (newh - payload);
820 	}
821 
822 	/* finally copy this fragment and possibly return whole packet */
823 	memcpy((uchar *)thisfrag, indata + IP_HDR_SIZE, len);
824 	if (!done)
825 		return NULL;
826 
827 	localip->ip_len = htons(total_len);
828 	*lenp = total_len + IP_HDR_SIZE;
829 	return localip;
830 }
831 
832 static inline struct ip_udp_hdr *NetDefragment(struct ip_udp_hdr *ip, int *lenp)
833 {
834 	u16 ip_off = ntohs(ip->ip_off);
835 	if (!(ip_off & (IP_OFFS | IP_FLAGS_MFRAG)))
836 		return ip; /* not a fragment */
837 	return __NetDefragment(ip, lenp);
838 }
839 
840 #else /* !CONFIG_IP_DEFRAG */
841 
842 static inline struct ip_udp_hdr *NetDefragment(struct ip_udp_hdr *ip, int *lenp)
843 {
844 	u16 ip_off = ntohs(ip->ip_off);
845 	if (!(ip_off & (IP_OFFS | IP_FLAGS_MFRAG)))
846 		return ip; /* not a fragment */
847 	return NULL;
848 }
849 #endif
850 
851 /**
852  * Receive an ICMP packet. We deal with REDIRECT and PING here, and silently
853  * drop others.
854  *
855  * @parma ip	IP packet containing the ICMP
856  */
857 static void receive_icmp(struct ip_udp_hdr *ip, int len,
858 			IPaddr_t src_ip, struct ethernet_hdr *et)
859 {
860 	struct icmp_hdr *icmph = (struct icmp_hdr *)&ip->udp_src;
861 
862 	switch (icmph->type) {
863 	case ICMP_REDIRECT:
864 		if (icmph->code != ICMP_REDIR_HOST)
865 			return;
866 		printf(" ICMP Host Redirect to %pI4 ",
867 			&icmph->un.gateway);
868 		break;
869 	default:
870 #if defined(CONFIG_CMD_PING)
871 		ping_receive(et, ip, len);
872 #endif
873 #ifdef CONFIG_CMD_TFTPPUT
874 		if (packet_icmp_handler)
875 			packet_icmp_handler(icmph->type, icmph->code,
876 				ntohs(ip->udp_dst), src_ip, ntohs(ip->udp_src),
877 				icmph->un.data, ntohs(ip->udp_len));
878 #endif
879 		break;
880 	}
881 }
882 
883 void
884 NetReceive(uchar *inpkt, int len)
885 {
886 	struct ethernet_hdr *et;
887 	struct ip_udp_hdr *ip;
888 	IPaddr_t dst_ip;
889 	IPaddr_t src_ip;
890 	int eth_proto;
891 #if defined(CONFIG_CMD_CDP)
892 	int iscdp;
893 #endif
894 	ushort cti = 0, vlanid = VLAN_NONE, myvlanid, mynvlanid;
895 
896 	debug("packet received\n");
897 
898 	NetRxPacket = inpkt;
899 	NetRxPacketLen = len;
900 	et = (struct ethernet_hdr *)inpkt;
901 
902 	/* too small packet? */
903 	if (len < ETHER_HDR_SIZE)
904 		return;
905 
906 #ifdef CONFIG_API
907 	if (push_packet) {
908 		(*push_packet)(inpkt, len);
909 		return;
910 	}
911 #endif
912 
913 #if defined(CONFIG_CMD_CDP)
914 	/* keep track if packet is CDP */
915 	iscdp = is_cdp_packet(et->et_dest);
916 #endif
917 
918 	myvlanid = ntohs(NetOurVLAN);
919 	if (myvlanid == (ushort)-1)
920 		myvlanid = VLAN_NONE;
921 	mynvlanid = ntohs(NetOurNativeVLAN);
922 	if (mynvlanid == (ushort)-1)
923 		mynvlanid = VLAN_NONE;
924 
925 	eth_proto = ntohs(et->et_protlen);
926 
927 	debug("packet received\n");
928 
929 	if (eth_proto < 1514) {
930 		struct e802_hdr *et802 = (struct e802_hdr *)et;
931 		/*
932 		 *	Got a 802.2 packet.  Check the other protocol field.
933 		 *	XXX VLAN over 802.2+SNAP not implemented!
934 		 */
935 		eth_proto = ntohs(et802->et_prot);
936 
937 		ip = (struct ip_udp_hdr *)(inpkt + E802_HDR_SIZE);
938 		len -= E802_HDR_SIZE;
939 
940 	} else if (eth_proto != PROT_VLAN) {	/* normal packet */
941 		ip = (struct ip_udp_hdr *)(inpkt + ETHER_HDR_SIZE);
942 		len -= ETHER_HDR_SIZE;
943 
944 	} else {			/* VLAN packet */
945 		struct vlan_ethernet_hdr *vet =
946 			(struct vlan_ethernet_hdr *)et;
947 
948 		debug("VLAN packet received\n");
949 
950 		/* too small packet? */
951 		if (len < VLAN_ETHER_HDR_SIZE)
952 			return;
953 
954 		/* if no VLAN active */
955 		if ((ntohs(NetOurVLAN) & VLAN_IDMASK) == VLAN_NONE
956 #if defined(CONFIG_CMD_CDP)
957 				&& iscdp == 0
958 #endif
959 				)
960 			return;
961 
962 		cti = ntohs(vet->vet_tag);
963 		vlanid = cti & VLAN_IDMASK;
964 		eth_proto = ntohs(vet->vet_type);
965 
966 		ip = (struct ip_udp_hdr *)(inpkt + VLAN_ETHER_HDR_SIZE);
967 		len -= VLAN_ETHER_HDR_SIZE;
968 	}
969 
970 	debug("Receive from protocol 0x%x\n", eth_proto);
971 
972 #if defined(CONFIG_CMD_CDP)
973 	if (iscdp) {
974 		cdp_receive((uchar *)ip, len);
975 		return;
976 	}
977 #endif
978 
979 	if ((myvlanid & VLAN_IDMASK) != VLAN_NONE) {
980 		if (vlanid == VLAN_NONE)
981 			vlanid = (mynvlanid & VLAN_IDMASK);
982 		/* not matched? */
983 		if (vlanid != (myvlanid & VLAN_IDMASK))
984 			return;
985 	}
986 
987 	switch (eth_proto) {
988 
989 	case PROT_ARP:
990 		ArpReceive(et, ip, len);
991 		break;
992 
993 #ifdef CONFIG_CMD_RARP
994 	case PROT_RARP:
995 		rarp_receive(ip, len);
996 		break;
997 #endif
998 	case PROT_IP:
999 		debug("Got IP\n");
1000 		/* Before we start poking the header, make sure it is there */
1001 		if (len < IP_UDP_HDR_SIZE) {
1002 			debug("len bad %d < %lu\n", len,
1003 				(ulong)IP_UDP_HDR_SIZE);
1004 			return;
1005 		}
1006 		/* Check the packet length */
1007 		if (len < ntohs(ip->ip_len)) {
1008 			printf("len bad %d < %d\n", len, ntohs(ip->ip_len));
1009 			return;
1010 		}
1011 		len = ntohs(ip->ip_len);
1012 		debug("len=%d, v=%02x\n", len, ip->ip_hl_v & 0xff);
1013 
1014 		/* Can't deal with anything except IPv4 */
1015 		if ((ip->ip_hl_v & 0xf0) != 0x40)
1016 			return;
1017 		/* Can't deal with IP options (headers != 20 bytes) */
1018 		if ((ip->ip_hl_v & 0x0f) > 0x05)
1019 			return;
1020 		/* Check the Checksum of the header */
1021 		if (!NetCksumOk((uchar *)ip, IP_HDR_SIZE / 2)) {
1022 			puts("checksum bad\n");
1023 			return;
1024 		}
1025 		/* If it is not for us, ignore it */
1026 		dst_ip = NetReadIP(&ip->ip_dst);
1027 		if (NetOurIP && dst_ip != NetOurIP && dst_ip != 0xFFFFFFFF) {
1028 #ifdef CONFIG_MCAST_TFTP
1029 			if (Mcast_addr != dst_ip)
1030 #endif
1031 				return;
1032 		}
1033 		/* Read source IP address for later use */
1034 		src_ip = NetReadIP(&ip->ip_src);
1035 		/*
1036 		 * The function returns the unchanged packet if it's not
1037 		 * a fragment, and either the complete packet or NULL if
1038 		 * it is a fragment (if !CONFIG_IP_DEFRAG, it returns NULL)
1039 		 */
1040 		ip = NetDefragment(ip, &len);
1041 		if (!ip)
1042 			return;
1043 		/*
1044 		 * watch for ICMP host redirects
1045 		 *
1046 		 * There is no real handler code (yet). We just watch
1047 		 * for ICMP host redirect messages. In case anybody
1048 		 * sees these messages: please contact me
1049 		 * (wd@denx.de), or - even better - send me the
1050 		 * necessary fixes :-)
1051 		 *
1052 		 * Note: in all cases where I have seen this so far
1053 		 * it was a problem with the router configuration,
1054 		 * for instance when a router was configured in the
1055 		 * BOOTP reply, but the TFTP server was on the same
1056 		 * subnet. So this is probably a warning that your
1057 		 * configuration might be wrong. But I'm not really
1058 		 * sure if there aren't any other situations.
1059 		 *
1060 		 * Simon Glass <sjg@chromium.org>: We get an ICMP when
1061 		 * we send a tftp packet to a dead connection, or when
1062 		 * there is no server at the other end.
1063 		 */
1064 		if (ip->ip_p == IPPROTO_ICMP) {
1065 			receive_icmp(ip, len, src_ip, et);
1066 			return;
1067 		} else if (ip->ip_p != IPPROTO_UDP) {	/* Only UDP packets */
1068 			return;
1069 		}
1070 
1071 #ifdef CONFIG_UDP_CHECKSUM
1072 		if (ip->udp_xsum != 0) {
1073 			ulong   xsum;
1074 			ushort *sumptr;
1075 			ushort  sumlen;
1076 
1077 			xsum  = ip->ip_p;
1078 			xsum += (ntohs(ip->udp_len));
1079 			xsum += (ntohl(ip->ip_src) >> 16) & 0x0000ffff;
1080 			xsum += (ntohl(ip->ip_src) >>  0) & 0x0000ffff;
1081 			xsum += (ntohl(ip->ip_dst) >> 16) & 0x0000ffff;
1082 			xsum += (ntohl(ip->ip_dst) >>  0) & 0x0000ffff;
1083 
1084 			sumlen = ntohs(ip->udp_len);
1085 			sumptr = (ushort *) &(ip->udp_src);
1086 
1087 			while (sumlen > 1) {
1088 				ushort sumdata;
1089 
1090 				sumdata = *sumptr++;
1091 				xsum += ntohs(sumdata);
1092 				sumlen -= 2;
1093 			}
1094 			if (sumlen > 0) {
1095 				ushort sumdata;
1096 
1097 				sumdata = *(unsigned char *) sumptr;
1098 				sumdata = (sumdata << 8) & 0xff00;
1099 				xsum += sumdata;
1100 			}
1101 			while ((xsum >> 16) != 0) {
1102 				xsum = (xsum & 0x0000ffff) +
1103 				       ((xsum >> 16) & 0x0000ffff);
1104 			}
1105 			if ((xsum != 0x00000000) && (xsum != 0x0000ffff)) {
1106 				printf(" UDP wrong checksum %08lx %08x\n",
1107 					xsum, ntohs(ip->udp_xsum));
1108 				return;
1109 			}
1110 		}
1111 #endif
1112 
1113 
1114 #ifdef CONFIG_NETCONSOLE
1115 		nc_input_packet((uchar *)ip + IP_UDP_HDR_SIZE,
1116 					ntohs(ip->udp_dst),
1117 					ntohs(ip->udp_src),
1118 					ntohs(ip->udp_len) - UDP_HDR_SIZE);
1119 #endif
1120 		/*
1121 		 *	IP header OK.  Pass the packet to the current handler.
1122 		 */
1123 		(*udp_packet_handler)((uchar *)ip + IP_UDP_HDR_SIZE,
1124 				ntohs(ip->udp_dst),
1125 				src_ip,
1126 				ntohs(ip->udp_src),
1127 				ntohs(ip->udp_len) - UDP_HDR_SIZE);
1128 		break;
1129 	}
1130 }
1131 
1132 
1133 /**********************************************************************/
1134 
1135 static int net_check_prereq(enum proto_t protocol)
1136 {
1137 	switch (protocol) {
1138 		/* Fall through */
1139 #if defined(CONFIG_CMD_PING)
1140 	case PING:
1141 		if (NetPingIP == 0) {
1142 			puts("*** ERROR: ping address not given\n");
1143 			return 1;
1144 		}
1145 		goto common;
1146 #endif
1147 #if defined(CONFIG_CMD_SNTP)
1148 	case SNTP:
1149 		if (NetNtpServerIP == 0) {
1150 			puts("*** ERROR: NTP server address not given\n");
1151 			return 1;
1152 		}
1153 		goto common;
1154 #endif
1155 #if defined(CONFIG_CMD_DNS)
1156 	case DNS:
1157 		if (NetOurDNSIP == 0) {
1158 			puts("*** ERROR: DNS server address not given\n");
1159 			return 1;
1160 		}
1161 		goto common;
1162 #endif
1163 #if defined(CONFIG_CMD_NFS)
1164 	case NFS:
1165 #endif
1166 	case TFTPGET:
1167 	case TFTPPUT:
1168 		if (NetServerIP == 0) {
1169 			puts("*** ERROR: `serverip' not set\n");
1170 			return 1;
1171 		}
1172 #if	defined(CONFIG_CMD_PING) || defined(CONFIG_CMD_SNTP) || \
1173 	defined(CONFIG_CMD_DNS)
1174 common:
1175 #endif
1176 		/* Fall through */
1177 
1178 	case NETCONS:
1179 	case TFTPSRV:
1180 		if (NetOurIP == 0) {
1181 			puts("*** ERROR: `ipaddr' not set\n");
1182 			return 1;
1183 		}
1184 		/* Fall through */
1185 
1186 #ifdef CONFIG_CMD_RARP
1187 	case RARP:
1188 #endif
1189 	case BOOTP:
1190 	case CDP:
1191 	case DHCP:
1192 		if (memcmp(NetOurEther, "\0\0\0\0\0\0", 6) == 0) {
1193 			int num = eth_get_dev_index();
1194 
1195 			switch (num) {
1196 			case -1:
1197 				puts("*** ERROR: No ethernet found.\n");
1198 				return 1;
1199 			case 0:
1200 				puts("*** ERROR: `ethaddr' not set\n");
1201 				break;
1202 			default:
1203 				printf("*** ERROR: `eth%daddr' not set\n",
1204 					num);
1205 				break;
1206 			}
1207 
1208 			NetStartAgain();
1209 			return 2;
1210 		}
1211 		/* Fall through */
1212 	default:
1213 		return 0;
1214 	}
1215 	return 0;		/* OK */
1216 }
1217 /**********************************************************************/
1218 
1219 int
1220 NetCksumOk(uchar *ptr, int len)
1221 {
1222 	return !((NetCksum(ptr, len) + 1) & 0xfffe);
1223 }
1224 
1225 
1226 unsigned
1227 NetCksum(uchar *ptr, int len)
1228 {
1229 	ulong	xsum;
1230 	ushort *p = (ushort *)ptr;
1231 
1232 	xsum = 0;
1233 	while (len-- > 0)
1234 		xsum += *p++;
1235 	xsum = (xsum & 0xffff) + (xsum >> 16);
1236 	xsum = (xsum & 0xffff) + (xsum >> 16);
1237 	return xsum & 0xffff;
1238 }
1239 
1240 int
1241 NetEthHdrSize(void)
1242 {
1243 	ushort myvlanid;
1244 
1245 	myvlanid = ntohs(NetOurVLAN);
1246 	if (myvlanid == (ushort)-1)
1247 		myvlanid = VLAN_NONE;
1248 
1249 	return ((myvlanid & VLAN_IDMASK) == VLAN_NONE) ? ETHER_HDR_SIZE :
1250 		VLAN_ETHER_HDR_SIZE;
1251 }
1252 
1253 int
1254 NetSetEther(uchar *xet, uchar * addr, uint prot)
1255 {
1256 	struct ethernet_hdr *et = (struct ethernet_hdr *)xet;
1257 	ushort myvlanid;
1258 
1259 	myvlanid = ntohs(NetOurVLAN);
1260 	if (myvlanid == (ushort)-1)
1261 		myvlanid = VLAN_NONE;
1262 
1263 	memcpy(et->et_dest, addr, 6);
1264 	memcpy(et->et_src, NetOurEther, 6);
1265 	if ((myvlanid & VLAN_IDMASK) == VLAN_NONE) {
1266 		et->et_protlen = htons(prot);
1267 		return ETHER_HDR_SIZE;
1268 	} else {
1269 		struct vlan_ethernet_hdr *vet =
1270 			(struct vlan_ethernet_hdr *)xet;
1271 
1272 		vet->vet_vlan_type = htons(PROT_VLAN);
1273 		vet->vet_tag = htons((0 << 5) | (myvlanid & VLAN_IDMASK));
1274 		vet->vet_type = htons(prot);
1275 		return VLAN_ETHER_HDR_SIZE;
1276 	}
1277 }
1278 
1279 int net_update_ether(struct ethernet_hdr *et, uchar *addr, uint prot)
1280 {
1281 	ushort protlen;
1282 
1283 	memcpy(et->et_dest, addr, 6);
1284 	memcpy(et->et_src, NetOurEther, 6);
1285 	protlen = ntohs(et->et_protlen);
1286 	if (protlen == PROT_VLAN) {
1287 		struct vlan_ethernet_hdr *vet =
1288 			(struct vlan_ethernet_hdr *)et;
1289 		vet->vet_type = htons(prot);
1290 		return VLAN_ETHER_HDR_SIZE;
1291 	} else if (protlen > 1514) {
1292 		et->et_protlen = htons(prot);
1293 		return ETHER_HDR_SIZE;
1294 	} else {
1295 		/* 802.2 + SNAP */
1296 		struct e802_hdr *et802 = (struct e802_hdr *)et;
1297 		et802->et_prot = htons(prot);
1298 		return E802_HDR_SIZE;
1299 	}
1300 }
1301 
1302 void net_set_ip_header(uchar *pkt, IPaddr_t dest, IPaddr_t source)
1303 {
1304 	struct ip_udp_hdr *ip = (struct ip_udp_hdr *)pkt;
1305 
1306 	/*
1307 	 *	Construct an IP header.
1308 	 */
1309 	/* IP_HDR_SIZE / 4 (not including UDP) */
1310 	ip->ip_hl_v  = 0x45;
1311 	ip->ip_tos   = 0;
1312 	ip->ip_len   = htons(IP_HDR_SIZE);
1313 	ip->ip_id    = htons(NetIPID++);
1314 	ip->ip_off   = htons(IP_FLAGS_DFRAG);	/* Don't fragment */
1315 	ip->ip_ttl   = 255;
1316 	ip->ip_sum   = 0;
1317 	/* already in network byte order */
1318 	NetCopyIP((void *)&ip->ip_src, &source);
1319 	/* already in network byte order */
1320 	NetCopyIP((void *)&ip->ip_dst, &dest);
1321 }
1322 
1323 void net_set_udp_header(uchar *pkt, IPaddr_t dest, int dport, int sport,
1324 			int len)
1325 {
1326 	struct ip_udp_hdr *ip = (struct ip_udp_hdr *)pkt;
1327 
1328 	/*
1329 	 *	If the data is an odd number of bytes, zero the
1330 	 *	byte after the last byte so that the checksum
1331 	 *	will work.
1332 	 */
1333 	if (len & 1)
1334 		pkt[IP_UDP_HDR_SIZE + len] = 0;
1335 
1336 	net_set_ip_header(pkt, dest, NetOurIP);
1337 	ip->ip_len   = htons(IP_UDP_HDR_SIZE + len);
1338 	ip->ip_p     = IPPROTO_UDP;
1339 	ip->ip_sum   = ~NetCksum((uchar *)ip, IP_HDR_SIZE >> 1);
1340 
1341 	ip->udp_src  = htons(sport);
1342 	ip->udp_dst  = htons(dport);
1343 	ip->udp_len  = htons(UDP_HDR_SIZE + len);
1344 	ip->udp_xsum = 0;
1345 }
1346 
1347 void copy_filename(char *dst, const char *src, int size)
1348 {
1349 	if (*src && (*src == '"')) {
1350 		++src;
1351 		--size;
1352 	}
1353 
1354 	while ((--size > 0) && *src && (*src != '"'))
1355 		*dst++ = *src++;
1356 	*dst = '\0';
1357 }
1358 
1359 #if	defined(CONFIG_CMD_NFS)		|| \
1360 	defined(CONFIG_CMD_SNTP)	|| \
1361 	defined(CONFIG_CMD_DNS)
1362 /*
1363  * make port a little random (1024-17407)
1364  * This keeps the math somewhat trivial to compute, and seems to work with
1365  * all supported protocols/clients/servers
1366  */
1367 unsigned int random_port(void)
1368 {
1369 	return 1024 + (get_timer(0) % 0x4000);
1370 }
1371 #endif
1372 
1373 void ip_to_string(IPaddr_t x, char *s)
1374 {
1375 	x = ntohl(x);
1376 	sprintf(s, "%d.%d.%d.%d",
1377 		(int) ((x >> 24) & 0xff),
1378 		(int) ((x >> 16) & 0xff),
1379 		(int) ((x >> 8) & 0xff), (int) ((x >> 0) & 0xff)
1380 	);
1381 }
1382 
1383 void VLAN_to_string(ushort x, char *s)
1384 {
1385 	x = ntohs(x);
1386 
1387 	if (x == (ushort)-1)
1388 		x = VLAN_NONE;
1389 
1390 	if (x == VLAN_NONE)
1391 		strcpy(s, "none");
1392 	else
1393 		sprintf(s, "%d", x & VLAN_IDMASK);
1394 }
1395 
1396 ushort string_to_VLAN(const char *s)
1397 {
1398 	ushort id;
1399 
1400 	if (s == NULL)
1401 		return htons(VLAN_NONE);
1402 
1403 	if (*s < '0' || *s > '9')
1404 		id = VLAN_NONE;
1405 	else
1406 		id = (ushort)simple_strtoul(s, NULL, 10);
1407 
1408 	return htons(id);
1409 }
1410 
1411 ushort getenv_VLAN(char *var)
1412 {
1413 	return string_to_VLAN(getenv(var));
1414 }
1415