xref: /openbmc/u-boot/net/net.c (revision ed09a554)
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  *	SPDX-License-Identifier:	GPL-2.0
10  */
11 
12 /*
13  * General Desription:
14  *
15  * The user interface supports commands for BOOTP, RARP, and TFTP.
16  * Also, we support ARP internally. Depending on available data,
17  * these interact as follows:
18  *
19  * BOOTP:
20  *
21  *	Prerequisites:	- own ethernet address
22  *	We want:	- own IP address
23  *			- TFTP server IP address
24  *			- name of bootfile
25  *	Next step:	ARP
26  *
27  * LINK_LOCAL:
28  *
29  *	Prerequisites:	- own ethernet address
30  *	We want:	- own IP address
31  *	Next step:	ARP
32  *
33  * RARP:
34  *
35  *	Prerequisites:	- own ethernet address
36  *	We want:	- own IP address
37  *			- TFTP server IP address
38  *	Next step:	ARP
39  *
40  * ARP:
41  *
42  *	Prerequisites:	- own ethernet address
43  *			- own IP address
44  *			- TFTP server IP address
45  *	We want:	- TFTP server ethernet address
46  *	Next step:	TFTP
47  *
48  * DHCP:
49  *
50  *     Prerequisites:	- own ethernet address
51  *     We want:		- IP, Netmask, ServerIP, Gateway IP
52  *			- bootfilename, lease time
53  *     Next step:	- TFTP
54  *
55  * TFTP:
56  *
57  *	Prerequisites:	- own ethernet address
58  *			- own IP address
59  *			- TFTP server IP address
60  *			- TFTP server ethernet address
61  *			- name of bootfile (if unknown, we use a default name
62  *			  derived from our own IP address)
63  *	We want:	- load the boot file
64  *	Next step:	none
65  *
66  * NFS:
67  *
68  *	Prerequisites:	- own ethernet address
69  *			- own IP address
70  *			- name of bootfile (if unknown, we use a default name
71  *			  derived from our own IP address)
72  *	We want:	- load the boot file
73  *	Next step:	none
74  *
75  * SNTP:
76  *
77  *	Prerequisites:	- own ethernet address
78  *			- own IP address
79  *	We want:	- network time
80  *	Next step:	none
81  */
82 
83 
84 #include <common.h>
85 #include <command.h>
86 #include <environment.h>
87 #include <errno.h>
88 #include <net.h>
89 #if defined(CONFIG_STATUS_LED)
90 #include <miiphy.h>
91 #include <status_led.h>
92 #endif
93 #include <watchdog.h>
94 #include <linux/compiler.h>
95 #include "arp.h"
96 #include "bootp.h"
97 #include "cdp.h"
98 #if defined(CONFIG_CMD_DNS)
99 #include "dns.h"
100 #endif
101 #include "link_local.h"
102 #include "nfs.h"
103 #include "ping.h"
104 #include "rarp.h"
105 #if defined(CONFIG_CMD_SNTP)
106 #include "sntp.h"
107 #endif
108 #include "tftp.h"
109 
110 DECLARE_GLOBAL_DATA_PTR;
111 
112 /** BOOTP EXTENTIONS **/
113 
114 /* Our subnet mask (0=unknown) */
115 struct in_addr net_netmask;
116 /* Our gateways IP address */
117 struct in_addr net_gateway;
118 /* Our DNS IP address */
119 struct in_addr net_dns_server;
120 #if defined(CONFIG_BOOTP_DNS2)
121 /* Our 2nd DNS IP address */
122 struct in_addr net_dns_server2;
123 #endif
124 
125 #ifdef CONFIG_MCAST_TFTP	/* Multicast TFTP */
126 struct in_addr net_mcast_addr;
127 #endif
128 
129 /** END OF BOOTP EXTENTIONS **/
130 
131 /* Our ethernet address */
132 u8 net_ethaddr[6];
133 /* Boot server enet address */
134 u8 net_server_ethaddr[6];
135 /* Our IP addr (0 = unknown) */
136 struct in_addr	net_ip;
137 /* Server IP addr (0 = unknown) */
138 struct in_addr	net_server_ip;
139 /* Current receive packet */
140 uchar *net_rx_packet;
141 /* Current rx packet length */
142 int		net_rx_packet_len;
143 /* IP packet ID */
144 static unsigned	net_ip_id;
145 /* Ethernet bcast address */
146 const u8 net_bcast_ethaddr[6] = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
147 const u8 net_null_ethaddr[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		net_restart_wrap;
155 /* Network loop restarted */
156 static int	net_restarted;
157 /* At least one device configured */
158 static int	net_dev_exists;
159 
160 /* XXX in both little & big endian machines 0xFFFF == ntohs(-1) */
161 /* default is without VLAN */
162 ushort		net_our_vlan = 0xFFFF;
163 /* ditto */
164 ushort		net_native_vlan = 0xFFFF;
165 
166 /* Boot File name */
167 char net_boot_file_name[128];
168 /* The actual transferred size of the bootfile (in bytes) */
169 u32 net_boot_file_size;
170 /* Boot file size in blocks as reported by the DHCP server */
171 u32 net_boot_file_expected_size_in_blocks;
172 
173 #if defined(CONFIG_CMD_SNTP)
174 /* NTP server IP address */
175 struct in_addr	net_ntp_server;
176 /* offset time from UTC */
177 int		net_ntp_time_offset;
178 #endif
179 
180 static uchar net_pkt_buf[(PKTBUFSRX+1) * PKTSIZE_ALIGN + PKTALIGN];
181 /* Receive packets */
182 uchar *net_rx_packets[PKTBUFSRX];
183 /* Current UDP RX packet handler */
184 static rxhand_f *udp_packet_handler;
185 /* Current ARP RX packet handler */
186 static rxhand_f *arp_packet_handler;
187 #ifdef CONFIG_CMD_TFTPPUT
188 /* Current ICMP rx handler */
189 static rxhand_icmp_f *packet_icmp_handler;
190 #endif
191 /* Current timeout handler */
192 static thand_f *time_handler;
193 /* Time base value */
194 static ulong	time_start;
195 /* Current timeout value */
196 static ulong	time_delta;
197 /* THE transmit packet */
198 uchar *net_tx_packet;
199 
200 static int net_check_prereq(enum proto_t protocol);
201 
202 static int net_try_count;
203 
204 int __maybe_unused net_busy_flag;
205 
206 /**********************************************************************/
207 
208 static int on_bootfile(const char *name, const char *value, enum env_op op,
209 	int flags)
210 {
211 	switch (op) {
212 	case env_op_create:
213 	case env_op_overwrite:
214 		copy_filename(net_boot_file_name, value,
215 			      sizeof(net_boot_file_name));
216 		break;
217 	default:
218 		break;
219 	}
220 
221 	return 0;
222 }
223 U_BOOT_ENV_CALLBACK(bootfile, on_bootfile);
224 
225 /*
226  * Check if autoload is enabled. If so, use either NFS or TFTP to download
227  * the boot file.
228  */
229 void net_auto_load(void)
230 {
231 #if defined(CONFIG_CMD_NFS)
232 	const char *s = getenv("autoload");
233 
234 	if (s != NULL && strcmp(s, "NFS") == 0) {
235 		/*
236 		 * Use NFS to load the bootfile.
237 		 */
238 		nfs_start();
239 		return;
240 	}
241 #endif
242 	if (getenv_yesno("autoload") == 0) {
243 		/*
244 		 * Just use BOOTP/RARP to configure system;
245 		 * Do not use TFTP to load the bootfile.
246 		 */
247 		net_set_state(NETLOOP_SUCCESS);
248 		return;
249 	}
250 	tftp_start(TFTPGET);
251 }
252 
253 static void net_init_loop(void)
254 {
255 	static int env_changed_id;
256 	int env_id = get_env_id();
257 
258 	/* update only when the environment has changed */
259 	if (env_changed_id != env_id) {
260 		net_ip = getenv_ip("ipaddr");
261 		net_gateway = getenv_ip("gatewayip");
262 		net_netmask = getenv_ip("netmask");
263 		net_server_ip = getenv_ip("serverip");
264 		net_native_vlan = getenv_vlan("nvlan");
265 		net_our_vlan = getenv_vlan("vlan");
266 #if defined(CONFIG_CMD_DNS)
267 		net_dns_server = getenv_ip("dnsip");
268 #endif
269 		env_changed_id = env_id;
270 	}
271 	if (eth_get_dev())
272 		memcpy(net_ethaddr, eth_get_ethaddr(), 6);
273 
274 	return;
275 }
276 
277 static void net_clear_handlers(void)
278 {
279 	net_set_udp_handler(NULL);
280 	net_set_arp_handler(NULL);
281 	net_set_timeout_handler(0, NULL);
282 }
283 
284 static void net_cleanup_loop(void)
285 {
286 	net_clear_handlers();
287 }
288 
289 void net_init(void)
290 {
291 	static int first_call = 1;
292 
293 	if (first_call) {
294 		/*
295 		 *	Setup packet buffers, aligned correctly.
296 		 */
297 		int i;
298 
299 		net_tx_packet = &net_pkt_buf[0] + (PKTALIGN - 1);
300 		net_tx_packet -= (ulong)net_tx_packet % PKTALIGN;
301 		for (i = 0; i < PKTBUFSRX; i++) {
302 			net_rx_packets[i] = net_tx_packet +
303 				(i + 1) * PKTSIZE_ALIGN;
304 		}
305 		arp_init();
306 		net_clear_handlers();
307 
308 		/* Only need to setup buffer pointers once. */
309 		first_call = 0;
310 	}
311 
312 	net_init_loop();
313 }
314 
315 /**********************************************************************/
316 /*
317  *	Main network processing loop.
318  */
319 
320 int net_loop(enum proto_t protocol)
321 {
322 	int ret = -EINVAL;
323 
324 	net_restarted = 0;
325 	net_dev_exists = 0;
326 	net_try_count = 1;
327 	debug_cond(DEBUG_INT_STATE, "--- net_loop Entry\n");
328 
329 	bootstage_mark_name(BOOTSTAGE_ID_ETH_START, "eth_start");
330 	net_init();
331 	if (eth_is_on_demand_init() || protocol != NETCONS) {
332 		eth_halt();
333 		eth_set_current();
334 		ret = eth_init();
335 		if (ret < 0) {
336 			eth_halt();
337 			return ret;
338 		}
339 	} else {
340 		eth_init_state_only();
341 	}
342 restart:
343 #ifdef CONFIG_USB_KEYBOARD
344 	net_busy_flag = 0;
345 #endif
346 	net_set_state(NETLOOP_CONTINUE);
347 
348 	/*
349 	 *	Start the ball rolling with the given start function.  From
350 	 *	here on, this code is a state machine driven by received
351 	 *	packets and timer events.
352 	 */
353 	debug_cond(DEBUG_INT_STATE, "--- net_loop Init\n");
354 	net_init_loop();
355 
356 	switch (net_check_prereq(protocol)) {
357 	case 1:
358 		/* network not configured */
359 		eth_halt();
360 		return -ENODEV;
361 
362 	case 2:
363 		/* network device not configured */
364 		break;
365 
366 	case 0:
367 		net_dev_exists = 1;
368 		net_boot_file_size = 0;
369 		switch (protocol) {
370 		case TFTPGET:
371 #ifdef CONFIG_CMD_TFTPPUT
372 		case TFTPPUT:
373 #endif
374 			/* always use ARP to get server ethernet address */
375 			tftp_start(protocol);
376 			break;
377 #ifdef CONFIG_CMD_TFTPSRV
378 		case TFTPSRV:
379 			tftp_start_server();
380 			break;
381 #endif
382 #if defined(CONFIG_CMD_DHCP)
383 		case DHCP:
384 			bootp_reset();
385 			net_ip.s_addr = 0;
386 			dhcp_request();		/* Basically same as BOOTP */
387 			break;
388 #endif
389 
390 		case BOOTP:
391 			bootp_reset();
392 			net_ip.s_addr = 0;
393 			bootp_request();
394 			break;
395 
396 #if defined(CONFIG_CMD_RARP)
397 		case RARP:
398 			rarp_try = 0;
399 			net_ip.s_addr = 0;
400 			rarp_request();
401 			break;
402 #endif
403 #if defined(CONFIG_CMD_PING)
404 		case PING:
405 			ping_start();
406 			break;
407 #endif
408 #if defined(CONFIG_CMD_NFS)
409 		case NFS:
410 			nfs_start();
411 			break;
412 #endif
413 #if defined(CONFIG_CMD_CDP)
414 		case CDP:
415 			cdp_start();
416 			break;
417 #endif
418 #if defined(CONFIG_NETCONSOLE) && !(CONFIG_SPL_BUILD)
419 		case NETCONS:
420 			nc_start();
421 			break;
422 #endif
423 #if defined(CONFIG_CMD_SNTP)
424 		case SNTP:
425 			sntp_start();
426 			break;
427 #endif
428 #if defined(CONFIG_CMD_DNS)
429 		case DNS:
430 			dns_start();
431 			break;
432 #endif
433 #if defined(CONFIG_CMD_LINK_LOCAL)
434 		case LINKLOCAL:
435 			link_local_start();
436 			break;
437 #endif
438 		default:
439 			break;
440 		}
441 
442 		break;
443 	}
444 
445 #if defined(CONFIG_MII) || defined(CONFIG_CMD_MII)
446 #if	defined(CONFIG_SYS_FAULT_ECHO_LINK_DOWN)	&& \
447 	defined(CONFIG_STATUS_LED)			&& \
448 	defined(STATUS_LED_RED)
449 	/*
450 	 * Echo the inverted link state to the fault LED.
451 	 */
452 	if (miiphy_link(eth_get_dev()->name, CONFIG_SYS_FAULT_MII_ADDR))
453 		status_led_set(STATUS_LED_RED, STATUS_LED_OFF);
454 	else
455 		status_led_set(STATUS_LED_RED, STATUS_LED_ON);
456 #endif /* CONFIG_SYS_FAULT_ECHO_LINK_DOWN, ... */
457 #endif /* CONFIG_MII, ... */
458 #ifdef CONFIG_USB_KEYBOARD
459 	net_busy_flag = 1;
460 #endif
461 
462 	/*
463 	 *	Main packet reception loop.  Loop receiving packets until
464 	 *	someone sets `net_state' to a state that terminates.
465 	 */
466 	for (;;) {
467 		WATCHDOG_RESET();
468 #ifdef CONFIG_SHOW_ACTIVITY
469 		show_activity(1);
470 #endif
471 		/*
472 		 *	Check the ethernet for a new packet.  The ethernet
473 		 *	receive routine will process it.
474 		 *	Most drivers return the most recent packet size, but not
475 		 *	errors that may have happened.
476 		 */
477 		eth_rx();
478 
479 		/*
480 		 *	Abort if ctrl-c was pressed.
481 		 */
482 		if (ctrlc()) {
483 			/* cancel any ARP that may not have completed */
484 			net_arp_wait_packet_ip.s_addr = 0;
485 
486 			net_cleanup_loop();
487 			eth_halt();
488 			/* Invalidate the last protocol */
489 			eth_set_last_protocol(BOOTP);
490 
491 			puts("\nAbort\n");
492 			/* include a debug print as well incase the debug
493 			   messages are directed to stderr */
494 			debug_cond(DEBUG_INT_STATE, "--- net_loop Abort!\n");
495 			goto done;
496 		}
497 
498 		arp_timeout_check();
499 
500 		/*
501 		 *	Check for a timeout, and run the timeout handler
502 		 *	if we have one.
503 		 */
504 		if (time_handler &&
505 		    ((get_timer(0) - time_start) > time_delta)) {
506 			thand_f *x;
507 
508 #if defined(CONFIG_MII) || defined(CONFIG_CMD_MII)
509 #if	defined(CONFIG_SYS_FAULT_ECHO_LINK_DOWN)	&& \
510 	defined(CONFIG_STATUS_LED)			&& \
511 	defined(STATUS_LED_RED)
512 			/*
513 			 * Echo the inverted link state to the fault LED.
514 			 */
515 			if (miiphy_link(eth_get_dev()->name,
516 					CONFIG_SYS_FAULT_MII_ADDR))
517 				status_led_set(STATUS_LED_RED, STATUS_LED_OFF);
518 			else
519 				status_led_set(STATUS_LED_RED, STATUS_LED_ON);
520 #endif /* CONFIG_SYS_FAULT_ECHO_LINK_DOWN, ... */
521 #endif /* CONFIG_MII, ... */
522 			debug_cond(DEBUG_INT_STATE, "--- net_loop timeout\n");
523 			x = time_handler;
524 			time_handler = (thand_f *)0;
525 			(*x)();
526 		}
527 
528 		if (net_state == NETLOOP_FAIL)
529 			ret = net_start_again();
530 
531 		switch (net_state) {
532 		case NETLOOP_RESTART:
533 			net_restarted = 1;
534 			goto restart;
535 
536 		case NETLOOP_SUCCESS:
537 			net_cleanup_loop();
538 			if (net_boot_file_size > 0) {
539 				printf("Bytes transferred = %d (%x hex)\n",
540 				       net_boot_file_size, net_boot_file_size);
541 				setenv_hex("filesize", net_boot_file_size);
542 				setenv_hex("fileaddr", load_addr);
543 			}
544 			if (protocol != NETCONS)
545 				eth_halt();
546 			else
547 				eth_halt_state_only();
548 
549 			eth_set_last_protocol(protocol);
550 
551 			ret = net_boot_file_size;
552 			debug_cond(DEBUG_INT_STATE, "--- net_loop Success!\n");
553 			goto done;
554 
555 		case NETLOOP_FAIL:
556 			net_cleanup_loop();
557 			/* Invalidate the last protocol */
558 			eth_set_last_protocol(BOOTP);
559 			debug_cond(DEBUG_INT_STATE, "--- net_loop Fail!\n");
560 			goto done;
561 
562 		case NETLOOP_CONTINUE:
563 			continue;
564 		}
565 	}
566 
567 done:
568 #ifdef CONFIG_USB_KEYBOARD
569 	net_busy_flag = 0;
570 #endif
571 #ifdef CONFIG_CMD_TFTPPUT
572 	/* Clear out the handlers */
573 	net_set_udp_handler(NULL);
574 	net_set_icmp_handler(NULL);
575 #endif
576 	return ret;
577 }
578 
579 /**********************************************************************/
580 
581 static void start_again_timeout_handler(void)
582 {
583 	net_set_state(NETLOOP_RESTART);
584 }
585 
586 int net_start_again(void)
587 {
588 	char *nretry;
589 	int retry_forever = 0;
590 	unsigned long retrycnt = 0;
591 	int ret;
592 
593 	nretry = getenv("netretry");
594 	if (nretry) {
595 		if (!strcmp(nretry, "yes"))
596 			retry_forever = 1;
597 		else if (!strcmp(nretry, "no"))
598 			retrycnt = 0;
599 		else if (!strcmp(nretry, "once"))
600 			retrycnt = 1;
601 		else
602 			retrycnt = simple_strtoul(nretry, NULL, 0);
603 	} else {
604 		retrycnt = 0;
605 		retry_forever = 0;
606 	}
607 
608 	if ((!retry_forever) && (net_try_count >= retrycnt)) {
609 		eth_halt();
610 		net_set_state(NETLOOP_FAIL);
611 		/*
612 		 * We don't provide a way for the protocol to return an error,
613 		 * but this is almost always the reason.
614 		 */
615 		return -ETIMEDOUT;
616 	}
617 
618 	net_try_count++;
619 
620 	eth_halt();
621 #if !defined(CONFIG_NET_DO_NOT_TRY_ANOTHER)
622 	eth_try_another(!net_restarted);
623 #endif
624 	ret = eth_init();
625 	if (net_restart_wrap) {
626 		net_restart_wrap = 0;
627 		if (net_dev_exists) {
628 			net_set_timeout_handler(10000UL,
629 						start_again_timeout_handler);
630 			net_set_udp_handler(NULL);
631 		} else {
632 			net_set_state(NETLOOP_FAIL);
633 		}
634 	} else {
635 		net_set_state(NETLOOP_RESTART);
636 	}
637 	return ret;
638 }
639 
640 /**********************************************************************/
641 /*
642  *	Miscelaneous bits.
643  */
644 
645 static void dummy_handler(uchar *pkt, unsigned dport,
646 			struct in_addr sip, unsigned sport,
647 			unsigned len)
648 {
649 }
650 
651 rxhand_f *net_get_udp_handler(void)
652 {
653 	return udp_packet_handler;
654 }
655 
656 void net_set_udp_handler(rxhand_f *f)
657 {
658 	debug_cond(DEBUG_INT_STATE, "--- net_loop UDP handler set (%p)\n", f);
659 	if (f == NULL)
660 		udp_packet_handler = dummy_handler;
661 	else
662 		udp_packet_handler = f;
663 }
664 
665 rxhand_f *net_get_arp_handler(void)
666 {
667 	return arp_packet_handler;
668 }
669 
670 void net_set_arp_handler(rxhand_f *f)
671 {
672 	debug_cond(DEBUG_INT_STATE, "--- net_loop ARP handler set (%p)\n", f);
673 	if (f == NULL)
674 		arp_packet_handler = dummy_handler;
675 	else
676 		arp_packet_handler = f;
677 }
678 
679 #ifdef CONFIG_CMD_TFTPPUT
680 void net_set_icmp_handler(rxhand_icmp_f *f)
681 {
682 	packet_icmp_handler = f;
683 }
684 #endif
685 
686 void net_set_timeout_handler(ulong iv, thand_f *f)
687 {
688 	if (iv == 0) {
689 		debug_cond(DEBUG_INT_STATE,
690 			   "--- net_loop timeout handler cancelled\n");
691 		time_handler = (thand_f *)0;
692 	} else {
693 		debug_cond(DEBUG_INT_STATE,
694 			   "--- net_loop timeout handler set (%p)\n", f);
695 		time_handler = f;
696 		time_start = get_timer(0);
697 		time_delta = iv * CONFIG_SYS_HZ / 1000;
698 	}
699 }
700 
701 int net_send_udp_packet(uchar *ether, struct in_addr dest, int dport, int sport,
702 		int payload_len)
703 {
704 	uchar *pkt;
705 	int eth_hdr_size;
706 	int pkt_hdr_size;
707 
708 	/* make sure the net_tx_packet is initialized (net_init() was called) */
709 	assert(net_tx_packet != NULL);
710 	if (net_tx_packet == NULL)
711 		return -1;
712 
713 	/* convert to new style broadcast */
714 	if (dest.s_addr == 0)
715 		dest.s_addr = 0xFFFFFFFF;
716 
717 	/* if broadcast, make the ether address a broadcast and don't do ARP */
718 	if (dest.s_addr == 0xFFFFFFFF)
719 		ether = (uchar *)net_bcast_ethaddr;
720 
721 	pkt = (uchar *)net_tx_packet;
722 
723 	eth_hdr_size = net_set_ether(pkt, ether, PROT_IP);
724 	pkt += eth_hdr_size;
725 	net_set_udp_header(pkt, dest, dport, sport, payload_len);
726 	pkt_hdr_size = eth_hdr_size + IP_UDP_HDR_SIZE;
727 
728 	/* if MAC address was not discovered yet, do an ARP request */
729 	if (memcmp(ether, net_null_ethaddr, 6) == 0) {
730 		debug_cond(DEBUG_DEV_PKT, "sending ARP for %pI4\n", &dest);
731 
732 		/* save the ip and eth addr for the packet to send after arp */
733 		net_arp_wait_packet_ip = dest;
734 		arp_wait_packet_ethaddr = ether;
735 
736 		/* size of the waiting packet */
737 		arp_wait_tx_packet_size = pkt_hdr_size + payload_len;
738 
739 		/* and do the ARP request */
740 		arp_wait_try = 1;
741 		arp_wait_timer_start = get_timer(0);
742 		arp_request();
743 		return 1;	/* waiting */
744 	} else {
745 		debug_cond(DEBUG_DEV_PKT, "sending UDP to %pI4/%pM\n",
746 			   &dest, ether);
747 		net_send_packet(net_tx_packet, pkt_hdr_size + payload_len);
748 		return 0;	/* transmitted */
749 	}
750 }
751 
752 #ifdef CONFIG_IP_DEFRAG
753 /*
754  * This function collects fragments in a single packet, according
755  * to the algorithm in RFC815. It returns NULL or the pointer to
756  * a complete packet, in static storage
757  */
758 #ifndef CONFIG_NET_MAXDEFRAG
759 #define CONFIG_NET_MAXDEFRAG 16384
760 #endif
761 /*
762  * MAXDEFRAG, above, is chosen in the config file and  is real data
763  * so we need to add the NFS overhead, which is more than TFTP.
764  * To use sizeof in the internal unnamed structures, we need a real
765  * instance (can't do "sizeof(struct rpc_t.u.reply))", unfortunately).
766  * The compiler doesn't complain nor allocates the actual structure
767  */
768 static struct rpc_t rpc_specimen;
769 #define IP_PKTSIZE (CONFIG_NET_MAXDEFRAG + sizeof(rpc_specimen.u.reply))
770 
771 #define IP_MAXUDP (IP_PKTSIZE - IP_HDR_SIZE)
772 
773 /*
774  * this is the packet being assembled, either data or frag control.
775  * Fragments go by 8 bytes, so this union must be 8 bytes long
776  */
777 struct hole {
778 	/* first_byte is address of this structure */
779 	u16 last_byte;	/* last byte in this hole + 1 (begin of next hole) */
780 	u16 next_hole;	/* index of next (in 8-b blocks), 0 == none */
781 	u16 prev_hole;	/* index of prev, 0 == none */
782 	u16 unused;
783 };
784 
785 static struct ip_udp_hdr *__net_defragment(struct ip_udp_hdr *ip, int *lenp)
786 {
787 	static uchar pkt_buff[IP_PKTSIZE] __aligned(PKTALIGN);
788 	static u16 first_hole, total_len;
789 	struct hole *payload, *thisfrag, *h, *newh;
790 	struct ip_udp_hdr *localip = (struct ip_udp_hdr *)pkt_buff;
791 	uchar *indata = (uchar *)ip;
792 	int offset8, start, len, done = 0;
793 	u16 ip_off = ntohs(ip->ip_off);
794 
795 	/* payload starts after IP header, this fragment is in there */
796 	payload = (struct hole *)(pkt_buff + IP_HDR_SIZE);
797 	offset8 =  (ip_off & IP_OFFS);
798 	thisfrag = payload + offset8;
799 	start = offset8 * 8;
800 	len = ntohs(ip->ip_len) - IP_HDR_SIZE;
801 
802 	if (start + len > IP_MAXUDP) /* fragment extends too far */
803 		return NULL;
804 
805 	if (!total_len || localip->ip_id != ip->ip_id) {
806 		/* new (or different) packet, reset structs */
807 		total_len = 0xffff;
808 		payload[0].last_byte = ~0;
809 		payload[0].next_hole = 0;
810 		payload[0].prev_hole = 0;
811 		first_hole = 0;
812 		/* any IP header will work, copy the first we received */
813 		memcpy(localip, ip, IP_HDR_SIZE);
814 	}
815 
816 	/*
817 	 * What follows is the reassembly algorithm. We use the payload
818 	 * array as a linked list of hole descriptors, as each hole starts
819 	 * at a multiple of 8 bytes. However, last byte can be whatever value,
820 	 * so it is represented as byte count, not as 8-byte blocks.
821 	 */
822 
823 	h = payload + first_hole;
824 	while (h->last_byte < start) {
825 		if (!h->next_hole) {
826 			/* no hole that far away */
827 			return NULL;
828 		}
829 		h = payload + h->next_hole;
830 	}
831 
832 	/* last fragment may be 1..7 bytes, the "+7" forces acceptance */
833 	if (offset8 + ((len + 7) / 8) <= h - payload) {
834 		/* no overlap with holes (dup fragment?) */
835 		return NULL;
836 	}
837 
838 	if (!(ip_off & IP_FLAGS_MFRAG)) {
839 		/* no more fragmentss: truncate this (last) hole */
840 		total_len = start + len;
841 		h->last_byte = start + len;
842 	}
843 
844 	/*
845 	 * There is some overlap: fix the hole list. This code doesn't
846 	 * deal with a fragment that overlaps with two different holes
847 	 * (thus being a superset of a previously-received fragment).
848 	 */
849 
850 	if ((h >= thisfrag) && (h->last_byte <= start + len)) {
851 		/* complete overlap with hole: remove hole */
852 		if (!h->prev_hole && !h->next_hole) {
853 			/* last remaining hole */
854 			done = 1;
855 		} else if (!h->prev_hole) {
856 			/* first hole */
857 			first_hole = h->next_hole;
858 			payload[h->next_hole].prev_hole = 0;
859 		} else if (!h->next_hole) {
860 			/* last hole */
861 			payload[h->prev_hole].next_hole = 0;
862 		} else {
863 			/* in the middle of the list */
864 			payload[h->next_hole].prev_hole = h->prev_hole;
865 			payload[h->prev_hole].next_hole = h->next_hole;
866 		}
867 
868 	} else if (h->last_byte <= start + len) {
869 		/* overlaps with final part of the hole: shorten this hole */
870 		h->last_byte = start;
871 
872 	} else if (h >= thisfrag) {
873 		/* overlaps with initial part of the hole: move this hole */
874 		newh = thisfrag + (len / 8);
875 		*newh = *h;
876 		h = newh;
877 		if (h->next_hole)
878 			payload[h->next_hole].prev_hole = (h - payload);
879 		if (h->prev_hole)
880 			payload[h->prev_hole].next_hole = (h - payload);
881 		else
882 			first_hole = (h - payload);
883 
884 	} else {
885 		/* fragment sits in the middle: split the hole */
886 		newh = thisfrag + (len / 8);
887 		*newh = *h;
888 		h->last_byte = start;
889 		h->next_hole = (newh - payload);
890 		newh->prev_hole = (h - payload);
891 		if (newh->next_hole)
892 			payload[newh->next_hole].prev_hole = (newh - payload);
893 	}
894 
895 	/* finally copy this fragment and possibly return whole packet */
896 	memcpy((uchar *)thisfrag, indata + IP_HDR_SIZE, len);
897 	if (!done)
898 		return NULL;
899 
900 	localip->ip_len = htons(total_len);
901 	*lenp = total_len + IP_HDR_SIZE;
902 	return localip;
903 }
904 
905 static inline struct ip_udp_hdr *net_defragment(struct ip_udp_hdr *ip,
906 	int *lenp)
907 {
908 	u16 ip_off = ntohs(ip->ip_off);
909 	if (!(ip_off & (IP_OFFS | IP_FLAGS_MFRAG)))
910 		return ip; /* not a fragment */
911 	return __net_defragment(ip, lenp);
912 }
913 
914 #else /* !CONFIG_IP_DEFRAG */
915 
916 static inline struct ip_udp_hdr *net_defragment(struct ip_udp_hdr *ip,
917 	int *lenp)
918 {
919 	u16 ip_off = ntohs(ip->ip_off);
920 	if (!(ip_off & (IP_OFFS | IP_FLAGS_MFRAG)))
921 		return ip; /* not a fragment */
922 	return NULL;
923 }
924 #endif
925 
926 /**
927  * Receive an ICMP packet. We deal with REDIRECT and PING here, and silently
928  * drop others.
929  *
930  * @parma ip	IP packet containing the ICMP
931  */
932 static void receive_icmp(struct ip_udp_hdr *ip, int len,
933 			struct in_addr src_ip, struct ethernet_hdr *et)
934 {
935 	struct icmp_hdr *icmph = (struct icmp_hdr *)&ip->udp_src;
936 
937 	switch (icmph->type) {
938 	case ICMP_REDIRECT:
939 		if (icmph->code != ICMP_REDIR_HOST)
940 			return;
941 		printf(" ICMP Host Redirect to %pI4 ",
942 		       &icmph->un.gateway);
943 		break;
944 	default:
945 #if defined(CONFIG_CMD_PING)
946 		ping_receive(et, ip, len);
947 #endif
948 #ifdef CONFIG_CMD_TFTPPUT
949 		if (packet_icmp_handler)
950 			packet_icmp_handler(icmph->type, icmph->code,
951 					    ntohs(ip->udp_dst), src_ip,
952 					    ntohs(ip->udp_src), icmph->un.data,
953 					    ntohs(ip->udp_len));
954 #endif
955 		break;
956 	}
957 }
958 
959 void net_process_received_packet(uchar *in_packet, int len)
960 {
961 	struct ethernet_hdr *et;
962 	struct ip_udp_hdr *ip;
963 	struct in_addr dst_ip;
964 	struct in_addr src_ip;
965 	int eth_proto;
966 #if defined(CONFIG_CMD_CDP)
967 	int iscdp;
968 #endif
969 	ushort cti = 0, vlanid = VLAN_NONE, myvlanid, mynvlanid;
970 
971 	debug_cond(DEBUG_NET_PKT, "packet received\n");
972 
973 	net_rx_packet = in_packet;
974 	net_rx_packet_len = len;
975 	et = (struct ethernet_hdr *)in_packet;
976 
977 	/* too small packet? */
978 	if (len < ETHER_HDR_SIZE)
979 		return;
980 
981 #ifdef CONFIG_API
982 	if (push_packet) {
983 		(*push_packet)(in_packet, len);
984 		return;
985 	}
986 #endif
987 
988 #if defined(CONFIG_CMD_CDP)
989 	/* keep track if packet is CDP */
990 	iscdp = is_cdp_packet(et->et_dest);
991 #endif
992 
993 	myvlanid = ntohs(net_our_vlan);
994 	if (myvlanid == (ushort)-1)
995 		myvlanid = VLAN_NONE;
996 	mynvlanid = ntohs(net_native_vlan);
997 	if (mynvlanid == (ushort)-1)
998 		mynvlanid = VLAN_NONE;
999 
1000 	eth_proto = ntohs(et->et_protlen);
1001 
1002 	if (eth_proto < 1514) {
1003 		struct e802_hdr *et802 = (struct e802_hdr *)et;
1004 		/*
1005 		 *	Got a 802.2 packet.  Check the other protocol field.
1006 		 *	XXX VLAN over 802.2+SNAP not implemented!
1007 		 */
1008 		eth_proto = ntohs(et802->et_prot);
1009 
1010 		ip = (struct ip_udp_hdr *)(in_packet + E802_HDR_SIZE);
1011 		len -= E802_HDR_SIZE;
1012 
1013 	} else if (eth_proto != PROT_VLAN) {	/* normal packet */
1014 		ip = (struct ip_udp_hdr *)(in_packet + ETHER_HDR_SIZE);
1015 		len -= ETHER_HDR_SIZE;
1016 
1017 	} else {			/* VLAN packet */
1018 		struct vlan_ethernet_hdr *vet =
1019 			(struct vlan_ethernet_hdr *)et;
1020 
1021 		debug_cond(DEBUG_NET_PKT, "VLAN packet received\n");
1022 
1023 		/* too small packet? */
1024 		if (len < VLAN_ETHER_HDR_SIZE)
1025 			return;
1026 
1027 		/* if no VLAN active */
1028 		if ((ntohs(net_our_vlan) & VLAN_IDMASK) == VLAN_NONE
1029 #if defined(CONFIG_CMD_CDP)
1030 				&& iscdp == 0
1031 #endif
1032 				)
1033 			return;
1034 
1035 		cti = ntohs(vet->vet_tag);
1036 		vlanid = cti & VLAN_IDMASK;
1037 		eth_proto = ntohs(vet->vet_type);
1038 
1039 		ip = (struct ip_udp_hdr *)(in_packet + VLAN_ETHER_HDR_SIZE);
1040 		len -= VLAN_ETHER_HDR_SIZE;
1041 	}
1042 
1043 	debug_cond(DEBUG_NET_PKT, "Receive from protocol 0x%x\n", eth_proto);
1044 
1045 #if defined(CONFIG_CMD_CDP)
1046 	if (iscdp) {
1047 		cdp_receive((uchar *)ip, len);
1048 		return;
1049 	}
1050 #endif
1051 
1052 	if ((myvlanid & VLAN_IDMASK) != VLAN_NONE) {
1053 		if (vlanid == VLAN_NONE)
1054 			vlanid = (mynvlanid & VLAN_IDMASK);
1055 		/* not matched? */
1056 		if (vlanid != (myvlanid & VLAN_IDMASK))
1057 			return;
1058 	}
1059 
1060 	switch (eth_proto) {
1061 	case PROT_ARP:
1062 		arp_receive(et, ip, len);
1063 		break;
1064 
1065 #ifdef CONFIG_CMD_RARP
1066 	case PROT_RARP:
1067 		rarp_receive(ip, len);
1068 		break;
1069 #endif
1070 	case PROT_IP:
1071 		debug_cond(DEBUG_NET_PKT, "Got IP\n");
1072 		/* Before we start poking the header, make sure it is there */
1073 		if (len < IP_UDP_HDR_SIZE) {
1074 			debug("len bad %d < %lu\n", len,
1075 			      (ulong)IP_UDP_HDR_SIZE);
1076 			return;
1077 		}
1078 		/* Check the packet length */
1079 		if (len < ntohs(ip->ip_len)) {
1080 			debug("len bad %d < %d\n", len, ntohs(ip->ip_len));
1081 			return;
1082 		}
1083 		len = ntohs(ip->ip_len);
1084 		debug_cond(DEBUG_NET_PKT, "len=%d, v=%02x\n",
1085 			   len, ip->ip_hl_v & 0xff);
1086 
1087 		/* Can't deal with anything except IPv4 */
1088 		if ((ip->ip_hl_v & 0xf0) != 0x40)
1089 			return;
1090 		/* Can't deal with IP options (headers != 20 bytes) */
1091 		if ((ip->ip_hl_v & 0x0f) > 0x05)
1092 			return;
1093 		/* Check the Checksum of the header */
1094 		if (!ip_checksum_ok((uchar *)ip, IP_HDR_SIZE)) {
1095 			debug("checksum bad\n");
1096 			return;
1097 		}
1098 		/* If it is not for us, ignore it */
1099 		dst_ip = net_read_ip(&ip->ip_dst);
1100 		if (net_ip.s_addr && dst_ip.s_addr != net_ip.s_addr &&
1101 		    dst_ip.s_addr != 0xFFFFFFFF) {
1102 #ifdef CONFIG_MCAST_TFTP
1103 			if (net_mcast_addr != dst_ip)
1104 #endif
1105 				return;
1106 		}
1107 		/* Read source IP address for later use */
1108 		src_ip = net_read_ip(&ip->ip_src);
1109 		/*
1110 		 * The function returns the unchanged packet if it's not
1111 		 * a fragment, and either the complete packet or NULL if
1112 		 * it is a fragment (if !CONFIG_IP_DEFRAG, it returns NULL)
1113 		 */
1114 		ip = net_defragment(ip, &len);
1115 		if (!ip)
1116 			return;
1117 		/*
1118 		 * watch for ICMP host redirects
1119 		 *
1120 		 * There is no real handler code (yet). We just watch
1121 		 * for ICMP host redirect messages. In case anybody
1122 		 * sees these messages: please contact me
1123 		 * (wd@denx.de), or - even better - send me the
1124 		 * necessary fixes :-)
1125 		 *
1126 		 * Note: in all cases where I have seen this so far
1127 		 * it was a problem with the router configuration,
1128 		 * for instance when a router was configured in the
1129 		 * BOOTP reply, but the TFTP server was on the same
1130 		 * subnet. So this is probably a warning that your
1131 		 * configuration might be wrong. But I'm not really
1132 		 * sure if there aren't any other situations.
1133 		 *
1134 		 * Simon Glass <sjg@chromium.org>: We get an ICMP when
1135 		 * we send a tftp packet to a dead connection, or when
1136 		 * there is no server at the other end.
1137 		 */
1138 		if (ip->ip_p == IPPROTO_ICMP) {
1139 			receive_icmp(ip, len, src_ip, et);
1140 			return;
1141 		} else if (ip->ip_p != IPPROTO_UDP) {	/* Only UDP packets */
1142 			return;
1143 		}
1144 
1145 		debug_cond(DEBUG_DEV_PKT,
1146 			   "received UDP (to=%pI4, from=%pI4, len=%d)\n",
1147 			   &dst_ip, &src_ip, len);
1148 
1149 #ifdef CONFIG_UDP_CHECKSUM
1150 		if (ip->udp_xsum != 0) {
1151 			ulong   xsum;
1152 			ushort *sumptr;
1153 			ushort  sumlen;
1154 
1155 			xsum  = ip->ip_p;
1156 			xsum += (ntohs(ip->udp_len));
1157 			xsum += (ntohl(ip->ip_src.s_addr) >> 16) & 0x0000ffff;
1158 			xsum += (ntohl(ip->ip_src.s_addr) >>  0) & 0x0000ffff;
1159 			xsum += (ntohl(ip->ip_dst.s_addr) >> 16) & 0x0000ffff;
1160 			xsum += (ntohl(ip->ip_dst.s_addr) >>  0) & 0x0000ffff;
1161 
1162 			sumlen = ntohs(ip->udp_len);
1163 			sumptr = (ushort *)&(ip->udp_src);
1164 
1165 			while (sumlen > 1) {
1166 				ushort sumdata;
1167 
1168 				sumdata = *sumptr++;
1169 				xsum += ntohs(sumdata);
1170 				sumlen -= 2;
1171 			}
1172 			if (sumlen > 0) {
1173 				ushort sumdata;
1174 
1175 				sumdata = *(unsigned char *)sumptr;
1176 				sumdata = (sumdata << 8) & 0xff00;
1177 				xsum += sumdata;
1178 			}
1179 			while ((xsum >> 16) != 0) {
1180 				xsum = (xsum & 0x0000ffff) +
1181 				       ((xsum >> 16) & 0x0000ffff);
1182 			}
1183 			if ((xsum != 0x00000000) && (xsum != 0x0000ffff)) {
1184 				printf(" UDP wrong checksum %08lx %08x\n",
1185 				       xsum, ntohs(ip->udp_xsum));
1186 				return;
1187 			}
1188 		}
1189 #endif
1190 
1191 #if defined(CONFIG_NETCONSOLE) && !(CONFIG_SPL_BUILD)
1192 		nc_input_packet((uchar *)ip + IP_UDP_HDR_SIZE,
1193 				src_ip,
1194 				ntohs(ip->udp_dst),
1195 				ntohs(ip->udp_src),
1196 				ntohs(ip->udp_len) - UDP_HDR_SIZE);
1197 #endif
1198 		/*
1199 		 * IP header OK.  Pass the packet to the current handler.
1200 		 */
1201 		(*udp_packet_handler)((uchar *)ip + IP_UDP_HDR_SIZE,
1202 				      ntohs(ip->udp_dst),
1203 				      src_ip,
1204 				      ntohs(ip->udp_src),
1205 				      ntohs(ip->udp_len) - UDP_HDR_SIZE);
1206 		break;
1207 	}
1208 }
1209 
1210 /**********************************************************************/
1211 
1212 static int net_check_prereq(enum proto_t protocol)
1213 {
1214 	switch (protocol) {
1215 		/* Fall through */
1216 #if defined(CONFIG_CMD_PING)
1217 	case PING:
1218 		if (net_ping_ip.s_addr == 0) {
1219 			puts("*** ERROR: ping address not given\n");
1220 			return 1;
1221 		}
1222 		goto common;
1223 #endif
1224 #if defined(CONFIG_CMD_SNTP)
1225 	case SNTP:
1226 		if (net_ntp_server.s_addr == 0) {
1227 			puts("*** ERROR: NTP server address not given\n");
1228 			return 1;
1229 		}
1230 		goto common;
1231 #endif
1232 #if defined(CONFIG_CMD_DNS)
1233 	case DNS:
1234 		if (net_dns_server.s_addr == 0) {
1235 			puts("*** ERROR: DNS server address not given\n");
1236 			return 1;
1237 		}
1238 		goto common;
1239 #endif
1240 #if defined(CONFIG_CMD_NFS)
1241 	case NFS:
1242 #endif
1243 		/* Fall through */
1244 	case TFTPGET:
1245 	case TFTPPUT:
1246 		if (net_server_ip.s_addr == 0) {
1247 			puts("*** ERROR: `serverip' not set\n");
1248 			return 1;
1249 		}
1250 #if	defined(CONFIG_CMD_PING) || defined(CONFIG_CMD_SNTP) || \
1251 	defined(CONFIG_CMD_DNS)
1252 common:
1253 #endif
1254 		/* Fall through */
1255 
1256 	case NETCONS:
1257 	case TFTPSRV:
1258 		if (net_ip.s_addr == 0) {
1259 			puts("*** ERROR: `ipaddr' not set\n");
1260 			return 1;
1261 		}
1262 		/* Fall through */
1263 
1264 #ifdef CONFIG_CMD_RARP
1265 	case RARP:
1266 #endif
1267 	case BOOTP:
1268 	case CDP:
1269 	case DHCP:
1270 	case LINKLOCAL:
1271 		if (memcmp(net_ethaddr, "\0\0\0\0\0\0", 6) == 0) {
1272 			int num = eth_get_dev_index();
1273 
1274 			switch (num) {
1275 			case -1:
1276 				puts("*** ERROR: No ethernet found.\n");
1277 				return 1;
1278 			case 0:
1279 				puts("*** ERROR: `ethaddr' not set\n");
1280 				break;
1281 			default:
1282 				printf("*** ERROR: `eth%daddr' not set\n",
1283 				       num);
1284 				break;
1285 			}
1286 
1287 			net_start_again();
1288 			return 2;
1289 		}
1290 		/* Fall through */
1291 	default:
1292 		return 0;
1293 	}
1294 	return 0;		/* OK */
1295 }
1296 /**********************************************************************/
1297 
1298 int
1299 net_eth_hdr_size(void)
1300 {
1301 	ushort myvlanid;
1302 
1303 	myvlanid = ntohs(net_our_vlan);
1304 	if (myvlanid == (ushort)-1)
1305 		myvlanid = VLAN_NONE;
1306 
1307 	return ((myvlanid & VLAN_IDMASK) == VLAN_NONE) ? ETHER_HDR_SIZE :
1308 		VLAN_ETHER_HDR_SIZE;
1309 }
1310 
1311 int net_set_ether(uchar *xet, const uchar *dest_ethaddr, uint prot)
1312 {
1313 	struct ethernet_hdr *et = (struct ethernet_hdr *)xet;
1314 	ushort myvlanid;
1315 
1316 	myvlanid = ntohs(net_our_vlan);
1317 	if (myvlanid == (ushort)-1)
1318 		myvlanid = VLAN_NONE;
1319 
1320 	memcpy(et->et_dest, dest_ethaddr, 6);
1321 	memcpy(et->et_src, net_ethaddr, 6);
1322 	if ((myvlanid & VLAN_IDMASK) == VLAN_NONE) {
1323 		et->et_protlen = htons(prot);
1324 		return ETHER_HDR_SIZE;
1325 	} else {
1326 		struct vlan_ethernet_hdr *vet =
1327 			(struct vlan_ethernet_hdr *)xet;
1328 
1329 		vet->vet_vlan_type = htons(PROT_VLAN);
1330 		vet->vet_tag = htons((0 << 5) | (myvlanid & VLAN_IDMASK));
1331 		vet->vet_type = htons(prot);
1332 		return VLAN_ETHER_HDR_SIZE;
1333 	}
1334 }
1335 
1336 int net_update_ether(struct ethernet_hdr *et, uchar *addr, uint prot)
1337 {
1338 	ushort protlen;
1339 
1340 	memcpy(et->et_dest, addr, 6);
1341 	memcpy(et->et_src, net_ethaddr, 6);
1342 	protlen = ntohs(et->et_protlen);
1343 	if (protlen == PROT_VLAN) {
1344 		struct vlan_ethernet_hdr *vet =
1345 			(struct vlan_ethernet_hdr *)et;
1346 		vet->vet_type = htons(prot);
1347 		return VLAN_ETHER_HDR_SIZE;
1348 	} else if (protlen > 1514) {
1349 		et->et_protlen = htons(prot);
1350 		return ETHER_HDR_SIZE;
1351 	} else {
1352 		/* 802.2 + SNAP */
1353 		struct e802_hdr *et802 = (struct e802_hdr *)et;
1354 		et802->et_prot = htons(prot);
1355 		return E802_HDR_SIZE;
1356 	}
1357 }
1358 
1359 void net_set_ip_header(uchar *pkt, struct in_addr dest, struct in_addr source)
1360 {
1361 	struct ip_udp_hdr *ip = (struct ip_udp_hdr *)pkt;
1362 
1363 	/*
1364 	 *	Construct an IP header.
1365 	 */
1366 	/* IP_HDR_SIZE / 4 (not including UDP) */
1367 	ip->ip_hl_v  = 0x45;
1368 	ip->ip_tos   = 0;
1369 	ip->ip_len   = htons(IP_HDR_SIZE);
1370 	ip->ip_id    = htons(net_ip_id++);
1371 	ip->ip_off   = htons(IP_FLAGS_DFRAG);	/* Don't fragment */
1372 	ip->ip_ttl   = 255;
1373 	ip->ip_sum   = 0;
1374 	/* already in network byte order */
1375 	net_copy_ip((void *)&ip->ip_src, &source);
1376 	/* already in network byte order */
1377 	net_copy_ip((void *)&ip->ip_dst, &dest);
1378 }
1379 
1380 void net_set_udp_header(uchar *pkt, struct in_addr dest, int dport, int sport,
1381 			int len)
1382 {
1383 	struct ip_udp_hdr *ip = (struct ip_udp_hdr *)pkt;
1384 
1385 	/*
1386 	 *	If the data is an odd number of bytes, zero the
1387 	 *	byte after the last byte so that the checksum
1388 	 *	will work.
1389 	 */
1390 	if (len & 1)
1391 		pkt[IP_UDP_HDR_SIZE + len] = 0;
1392 
1393 	net_set_ip_header(pkt, dest, net_ip);
1394 	ip->ip_len   = htons(IP_UDP_HDR_SIZE + len);
1395 	ip->ip_p     = IPPROTO_UDP;
1396 	ip->ip_sum   = compute_ip_checksum(ip, IP_HDR_SIZE);
1397 
1398 	ip->udp_src  = htons(sport);
1399 	ip->udp_dst  = htons(dport);
1400 	ip->udp_len  = htons(UDP_HDR_SIZE + len);
1401 	ip->udp_xsum = 0;
1402 }
1403 
1404 void copy_filename(char *dst, const char *src, int size)
1405 {
1406 	if (*src && (*src == '"')) {
1407 		++src;
1408 		--size;
1409 	}
1410 
1411 	while ((--size > 0) && *src && (*src != '"'))
1412 		*dst++ = *src++;
1413 	*dst = '\0';
1414 }
1415 
1416 #if	defined(CONFIG_CMD_NFS)		|| \
1417 	defined(CONFIG_CMD_SNTP)	|| \
1418 	defined(CONFIG_CMD_DNS)
1419 /*
1420  * make port a little random (1024-17407)
1421  * This keeps the math somewhat trivial to compute, and seems to work with
1422  * all supported protocols/clients/servers
1423  */
1424 unsigned int random_port(void)
1425 {
1426 	return 1024 + (get_timer(0) % 0x4000);
1427 }
1428 #endif
1429 
1430 void ip_to_string(struct in_addr x, char *s)
1431 {
1432 	x.s_addr = ntohl(x.s_addr);
1433 	sprintf(s, "%d.%d.%d.%d",
1434 		(int) ((x.s_addr >> 24) & 0xff),
1435 		(int) ((x.s_addr >> 16) & 0xff),
1436 		(int) ((x.s_addr >> 8) & 0xff),
1437 		(int) ((x.s_addr >> 0) & 0xff)
1438 	);
1439 }
1440 
1441 void vlan_to_string(ushort x, char *s)
1442 {
1443 	x = ntohs(x);
1444 
1445 	if (x == (ushort)-1)
1446 		x = VLAN_NONE;
1447 
1448 	if (x == VLAN_NONE)
1449 		strcpy(s, "none");
1450 	else
1451 		sprintf(s, "%d", x & VLAN_IDMASK);
1452 }
1453 
1454 ushort string_to_vlan(const char *s)
1455 {
1456 	ushort id;
1457 
1458 	if (s == NULL)
1459 		return htons(VLAN_NONE);
1460 
1461 	if (*s < '0' || *s > '9')
1462 		id = VLAN_NONE;
1463 	else
1464 		id = (ushort)simple_strtoul(s, NULL, 10);
1465 
1466 	return htons(id);
1467 }
1468 
1469 ushort getenv_vlan(char *var)
1470 {
1471 	return string_to_vlan(getenv(var));
1472 }
1473