summaryrefslogtreecommitdiffstats
path: root/net/dhcp.c
blob: fa4c4d1de1e464f869fe6a8637bb37a1ddec6a5b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
/*
 *	Based on LiMon - BOOTP.
 *
 *	Copyright 1994, 1995, 2000 Neil Russell.
 *	(See License)
 *	Copyright 2000 Roland Borde
 *	Copyright 2000 Paolo Scaffardi
 *	Copyright 2000-2004 Wolfgang Denk, wd@denx.de
 */

#include <common.h>
#include <command.h>
#include <complete.h>
#include <environment.h>
#include <clock.h>
#include <net.h>
#include <libbb.h>
#include <errno.h>
#include <magicvar.h>
#include <linux/err.h>
#include <getopt.h>
#include <globalvar.h>
#include <init.h>
#include <dhcp.h>

#define OPT_SIZE 312	/* Minimum DHCP Options size per RFC2131 - results in 576 byte pkt */

struct bootp {
	uint8_t		bp_op;		/* Operation				*/
#define OP_BOOTREQUEST	1
#define OP_BOOTREPLY	2
	uint8_t		bp_htype;	/* Hardware type			*/
#define HWT_ETHER	1
	uint8_t		bp_hlen;	/* Hardware address length		*/
#define HWL_ETHER	6
	uint8_t		bp_hops;	/* Hop count (gateway thing)		*/
	uint32_t	bp_id;		/* Transaction ID			*/
	uint16_t	bp_secs;	/* Seconds since boot			*/
	uint16_t	bp_spare1;	/* Alignment				*/
	IPaddr_t	bp_ciaddr;	/* Client IP address			*/
	IPaddr_t	bp_yiaddr;	/* Your (client) IP address		*/
	IPaddr_t	bp_siaddr;	/* Server IP address			*/
	IPaddr_t	bp_giaddr;	/* Gateway IP address			*/
	uint8_t		bp_chaddr[16];	/* Client hardware address		*/
	char		bp_sname[64];	/* Server host name			*/
	char		bp_file[128];	/* Boot file name			*/
	char		bp_vend[0];	/* Vendor information			*/
};

/* DHCP States */
typedef enum {
	INIT,
	INIT_REBOOT,
	REBOOTING,
	SELECTING,
	REQUESTING,
	REBINDING,
	BOUND,
	RENEWING,
} dhcp_state_t;

#define DHCP_DISCOVER 1
#define DHCP_OFFER    2
#define DHCP_REQUEST  3
#define DHCP_DECLINE  4
#define DHCP_ACK      5
#define DHCP_NAK      6
#define DHCP_RELEASE  7

#define BOOTP_VENDOR_MAGIC	0x63825363	/* RFC1048 Magic Cookie		*/

#define PORT_BOOTPS	67		/* BOOTP server UDP port		*/
#define PORT_BOOTPC	68		/* BOOTP client UDP port		*/

#define DHCP_MIN_EXT_LEN 64	/* minimal length of extension list	*/

static uint32_t Bootp_id;
static dhcp_state_t dhcp_state;
static uint32_t dhcp_leasetime;
static IPaddr_t net_dhcp_server_ip;
static uint64_t dhcp_start;
static char dhcp_tftpname[256];

static const char* dhcp_get_barebox_global(const char * var)
{
	char * var_global = asprintf("global.dhcp.%s", var);
	const char *val;

	if (!var_global)
		return NULL;

	val = getenv(var_global);
	free(var_global);
	return val;
}

static int dhcp_set_barebox_global(const char * var, char *val)
{
	char * var_global = asprintf("global.dhcp.%s", var);
	int ret;

	if (!var_global)
		return -ENOMEM;

	ret = setenv(var_global, val);
	free(var_global);
	return ret;
}

struct dhcp_opt {
	unsigned char option;
	/* request automatically the option when creating the DHCP request */
	bool optional;
	bool copy_only_if_valid;
	const char *barebox_var_name;
	const char *barebox_dhcp_global;
	void (*handle)(struct dhcp_opt *opt, unsigned char *data, int tlen);
	int (*handle_param)(struct dhcp_opt *dhcp_opt, u8 *e);
	void *data;

	struct bootp *bp;
};

static void netmask_handle(struct dhcp_opt *opt, unsigned char *popt, int optlen)
{
	IPaddr_t ip;

	ip = net_read_ip(popt);
	net_set_netmask(ip);
}

static void gateway_handle(struct dhcp_opt *opt, unsigned char *popt, int optlen)
{
	IPaddr_t ip;

	ip = net_read_ip(popt);
	net_set_gateway(ip);
}

static void env_ip_handle(struct dhcp_opt *opt, unsigned char *popt, int optlen)
{
	IPaddr_t ip;

	ip = net_read_ip(popt);
	if (IS_ENABLED(CONFIG_ENVIRONMENT_VARIABLES))
		setenv_ip(opt->barebox_var_name, ip);
}

static void env_str_handle(struct dhcp_opt *opt, unsigned char *popt, int optlen)
{
	char str[256];
	char *tmp = str;

	if (opt->data)
		tmp = opt->data;

	memcpy(tmp, popt, optlen);
	tmp[optlen] = 0;

	if (opt->copy_only_if_valid && !strlen(tmp))
		return;
	if (opt->barebox_var_name && IS_ENABLED(CONFIG_ENVIRONMENT_VARIABLES))
		setenv(opt->barebox_var_name, tmp);
	if (opt->barebox_dhcp_global && IS_ENABLED(CONFIG_GLOBALVAR))
		dhcp_set_barebox_global(opt->barebox_dhcp_global, tmp);

}

static void copy_uint32_handle(struct dhcp_opt *opt, unsigned char *popt, int optlen)
{
	net_copy_uint32(opt->data, (uint32_t *)popt);
};

static void copy_ip_handle(struct dhcp_opt *opt, unsigned char *popt, int optlen)
{
	net_copy_ip(opt->data, popt);
};

static void bootfile_vendorex_handle(struct dhcp_opt *opt, unsigned char *popt, int optlen)
{
	if (opt->bp->bp_file[0] != '\0')
		return;

	/*
	 * only use vendor boot file if we didn't
	 * receive a boot file in the main non-vendor
	 * part of the packet - god only knows why
	 * some vendors chose not to use this perfectly
	 * good spot to store the boot file (join on
	 * Tru64 Unix) it seems mind bogglingly crazy
	 * to me
	 */
	pr_warn("*** WARNING: using vendor optional boot file\n");

	/*
	 * I can't use dhcp_vendorex_proc here because I need
	 * to write into the bootp packet - even then I had to
	 * pass the bootp packet pointer into here as the
	 * second arg
	 */
	env_str_handle(opt, popt, optlen);
}

static int dhcp_set_string_options(struct dhcp_opt *param, u8 *e)
{
	int str_len;
	char* str = param->data;

	if (!str && param->barebox_var_name && IS_ENABLED(CONFIG_ENVIRONMENT_VARIABLES))
		str = (char*)getenv(param->barebox_var_name);

	if (!str && param->barebox_dhcp_global && IS_ENABLED(CONFIG_GLOBALVAR))
		str = (char*)dhcp_get_barebox_global(param->barebox_dhcp_global);

	if (!str)
		return 0;

	str_len = strlen(str);
	if (!str_len)
		return 0;

	*e++ = param->option;
	*e++ = str_len;
	memcpy(e, str, str_len);

	return str_len + 2;
}

#define DHCP_HOSTNAME		12
#define DHCP_VENDOR_ID		60
#define DHCP_CLIENT_ID		61
#define DHCP_USER_CLASS		77
#define DHCP_CLIENT_UUID	97

struct dhcp_opt dhcp_options[] = {
	{
		.option = 1,
		.handle = netmask_handle,
	}, {
		.option = 3,
		.handle = gateway_handle,
	}, {
		.option = 6,
		.handle = env_ip_handle,
		.barebox_var_name = "net.nameserver",
	}, {
		.option = DHCP_HOSTNAME,
		.copy_only_if_valid = 1,
		.handle = env_str_handle,
		.handle_param = dhcp_set_string_options,
		.barebox_var_name = "global.hostname",
	}, {
		.option = 15,
		.handle = env_str_handle,
		.barebox_var_name = "net.domainname",
	}, {
		.option = 17,
		.handle = env_str_handle,
		.barebox_dhcp_global = "rootpath",
	}, {
		.option = 51,
		.handle = copy_uint32_handle,
		.data = &dhcp_leasetime,
	}, {
		.option = 54,
		.handle = copy_ip_handle,
		.data = &net_dhcp_server_ip,
		.optional = true,
	}, {
		.option = DHCP_VENDOR_ID,
		.handle_param = dhcp_set_string_options,
		.barebox_dhcp_global = "vendor_id",
	},{
		.option = 66,
		.handle = env_str_handle,
		.barebox_dhcp_global = "tftp_server_name",
		.data = dhcp_tftpname,
	}, {
		.option = 67,
		.handle = bootfile_vendorex_handle,
		.barebox_dhcp_global = "bootfile",
	}, {
		.option = DHCP_CLIENT_ID,
		.handle_param = dhcp_set_string_options,
		.barebox_dhcp_global = "client_id",
	}, {
		.option = DHCP_USER_CLASS,
		.handle_param = dhcp_set_string_options,
		.barebox_dhcp_global = "user_class",
	}, {
		.option = DHCP_CLIENT_UUID,
		.handle_param = dhcp_set_string_options,
		.barebox_dhcp_global = "client_uuid",
	}, {
		.option = 224,
		.handle = env_str_handle,
		.barebox_dhcp_global = "oftree_file",
	},
};

static void dhcp_set_param_data(int option, void* data)
{
	struct dhcp_opt *opt;
	int i;

	for (i = 0; i < ARRAY_SIZE(dhcp_options); i++) {
		opt = &dhcp_options[i];

		if (opt->option == option) {
			opt->data = data;
			return;
		}
	}
}

static int dhcp_set_ip_options(int option, u8 *e, IPaddr_t ip)
{
	int tmp;

	if (!ip)
		return 0;

	tmp = ntohl(ip);

	*e++ = option;
	*e++ = 4;
	*e++ = tmp >> 24;
	*e++ = tmp >> 16;
	*e++ = tmp >> 8;
	*e++ = tmp & 0xff;

	return 6;
}

static int bootp_check_packet(unsigned char *pkt, unsigned src, unsigned len)
{
	struct bootp *bp = (struct bootp *) pkt;
	int retval = 0;

	if (src != PORT_BOOTPS)
		retval = -1;
	else if (len < sizeof(struct bootp))
		retval = -2;
	else if (bp->bp_op != OP_BOOTREQUEST &&
	    bp->bp_op != OP_BOOTREPLY &&
	    bp->bp_op != DHCP_OFFER &&
	    bp->bp_op != DHCP_ACK &&
	    bp->bp_op != DHCP_NAK ) {
		retval = -3;
	}
	else if (bp->bp_htype != HWT_ETHER)
		retval = -4;
	else if (bp->bp_hlen != HWL_ETHER)
		retval = -5;
	else if (net_read_uint32(&bp->bp_id) != Bootp_id) {
		retval = -6;
	}

	debug("Filtering pkt = %d\n", retval);

	return retval;
}

/*
 * Copy parameters of interest from BOOTP_REPLY/DHCP_OFFER packet
 */
static void bootp_copy_net_params(struct bootp *bp)
{
	IPaddr_t tmp_ip;

	tmp_ip = net_read_ip(&bp->bp_yiaddr);
	net_set_ip(tmp_ip);

	tmp_ip = net_read_ip(&bp->bp_siaddr);
	if (tmp_ip != 0)
		net_set_serverip(tmp_ip);

	if (strlen(bp->bp_file) > 0) {
		if (IS_ENABLED(CONFIG_ENVIRONMENT_VARIABLES))
			setenv("bootfile", bp->bp_file);
		if (IS_ENABLED(CONFIG_GLOBALVAR))
			dhcp_set_barebox_global("bootfile", bp->bp_file);
	}

	debug("bootfile: %s\n", bp->bp_file);
}

/*
 * Initialize BOOTP extension fields in the request.
 */
static int dhcp_extended (u8 *e, int message_type, IPaddr_t ServerID,
			  IPaddr_t RequestedIP)
{
	struct dhcp_opt *opt;
	int i;
	u8 *start = e;
	u8 *cnt;

	*e++ = 99;		/* RFC1048 Magic Cookie */
	*e++ = 130;
	*e++ = 83;
	*e++ = 99;

	*e++ = 53;		/* DHCP Message Type */
	*e++ = 1;
	*e++ = message_type;

	*e++ = 57;		/* Maximum DHCP Message Size */
	*e++ = 2;
	*e++ = (576 - 312 + OPT_SIZE) >> 8;
	*e++ = (576 - 312 + OPT_SIZE) & 0xff;


	e += dhcp_set_ip_options(50, e, RequestedIP);
	e += dhcp_set_ip_options(54, e, ServerID);

	for (i = 0; i < ARRAY_SIZE(dhcp_options); i++) {
		opt = &dhcp_options[i];
		if (opt->handle_param)
			e += opt->handle_param(opt, e);
	}

	*e++ = 55;		/* Parameter Request List */
	 cnt = e++;		/* Pointer to count of requested items */
	*cnt = 0;

	for (i = 0; i < ARRAY_SIZE(dhcp_options); i++) {
		if (dhcp_options[i].optional)
			continue;
		*e++  = dhcp_options[i].option;
		*cnt += 1;
	}
	*e++  = 255;		/* End of the list */

	/* Pad to minimal length */
	while ((e - start) <= DHCP_MIN_EXT_LEN)
		*e++ = 0;

	return e - start;
}

static struct net_connection *dhcp_con;

static int bootp_request(void)
{
	struct bootp *bp;
	int ext_len;
	int ret;
	unsigned char *payload = net_udp_get_payload(dhcp_con);
	const char *bfile;

	dhcp_state = INIT;

	debug("BOOTP broadcast\n");

	bp = (struct bootp *)payload;
	bp->bp_op = OP_BOOTREQUEST;
	bp->bp_htype = HWT_ETHER;
	bp->bp_hlen = HWL_ETHER;
	bp->bp_hops = 0;
	bp->bp_secs = htons(get_time_ns() >> 30);
	net_write_ip(&bp->bp_ciaddr, 0);
	net_write_ip(&bp->bp_yiaddr, 0);
	net_write_ip(&bp->bp_siaddr, 0);
	net_write_ip(&bp->bp_giaddr, 0);
	memcpy(bp->bp_chaddr, dhcp_con->et->et_src, 6);

	bfile = getenv("bootfile");
	if (bfile)
		safe_strncpy (bp->bp_file, bfile, sizeof(bp->bp_file));

	/* Request additional information from the BOOTP/DHCP server */
	ext_len = dhcp_extended((u8 *)bp->bp_vend, DHCP_DISCOVER, 0, 0);

	Bootp_id = (uint32_t)get_time_ns();
	net_copy_uint32(&bp->bp_id, &Bootp_id);

	dhcp_state = SELECTING;

	ret = net_udp_send(dhcp_con, sizeof(*bp) + ext_len);

	return ret;
}

static int dhcp_options_handle(unsigned char option, unsigned char *popt,
			       int optlen, struct bootp *bp)
{
	int i;
	struct dhcp_opt *opt;

	for (i = 0; i < ARRAY_SIZE(dhcp_options); i++) {
		opt = &dhcp_options[i];
		if (opt->option == option) {
			opt->bp = bp;
			opt->handle(opt, popt, optlen);
			goto end;
		}
	}

end:
	return i;
}

static void dhcp_options_process(unsigned char *popt, struct bootp *bp)
{
	unsigned char *end = popt + sizeof(*bp) + OPT_SIZE;
	int oplen;
	unsigned char option;
	int i;

	while (popt < end && *popt != 0xff) {
		oplen = *(popt + 1);
		option = *popt;

		i = dhcp_options_handle(option, popt + 2, oplen, bp);
		if (i == ARRAY_SIZE(dhcp_options))
			debug("*** Unhandled DHCP Option in OFFER/ACK: %d\n", option);

		popt += oplen + 2;	/* Process next option */
	}
}

static int dhcp_message_type(unsigned char *popt)
{
	if (net_read_uint32((uint32_t *)popt) != htonl(BOOTP_VENDOR_MAGIC))
		return -1;

	popt += 4;
	while ( *popt != 0xff ) {
		if ( *popt == 53 )	/* DHCP Message Type */
			return *(popt + 2);
		popt += *(popt + 1) + 2;	/* Scan through all options */
	}
	return -1;
}

static void dhcp_send_request_packet(struct bootp *bp_offer)
{
	struct bootp *bp;
	int extlen;
	IPaddr_t OfferedIP;
	unsigned char *payload = net_udp_get_payload(dhcp_con);

	debug("%s: Sending DHCPREQUEST\n", __func__);

	bp = (struct bootp *)payload;
	bp->bp_op = OP_BOOTREQUEST;
	bp->bp_htype = HWT_ETHER;
	bp->bp_hlen = HWL_ETHER;
	bp->bp_hops = 0;
	bp->bp_secs = htons(get_time_ns() >> 30);

	/*
	 * RFC3046 requires Relay Agents to discard packets with
	 * nonzero and offered giaddr
	 */
	net_write_ip(&bp->bp_giaddr, 0);

	memcpy(bp->bp_chaddr, dhcp_con->et->et_src, 6);

	/*
	 * ID is the id of the OFFER packet
	 */

	net_copy_uint32(&bp->bp_id, &bp_offer->bp_id);

	/*
	 * Copy options from OFFER packet if present
	 */
	net_copy_ip(&OfferedIP, &bp_offer->bp_yiaddr);
	extlen = dhcp_extended((u8 *)bp->bp_vend, DHCP_REQUEST, net_dhcp_server_ip,
				OfferedIP);

	debug("Transmitting DHCPREQUEST packet\n");
	net_udp_send(dhcp_con, sizeof(*bp) + extlen);
}

/*
 *	Handle DHCP received packets.
 */
static void dhcp_handler(void *ctx, char *packet, unsigned int len)
{
	char *pkt = net_eth_to_udp_payload(packet);
	struct udphdr *udp = net_eth_to_udphdr(packet);
	struct bootp *bp = (struct bootp *)pkt;

	len = net_eth_to_udplen(packet);

	debug("DHCPHandler: got packet: (len=%d) state: %d\n",
		len, dhcp_state);

	if (bootp_check_packet(pkt, ntohs(udp->uh_sport), len)) /* Filter out pkts we don't want */
		return;

	switch (dhcp_state) {
	case SELECTING:
		/*
		 * Wait an appropriate time for any potential DHCPOFFER packets
		 * to arrive.  Then select one, and generate DHCPREQUEST response.
		 * If filename is in format we recognize, assume it is a valid
		 * OFFER from a server we want.
		 */
		debug ("%s: state SELECTING, bp_file: \"%s\"\n", __func__, bp->bp_file);
		dhcp_state = REQUESTING;

		if (net_read_uint32((uint32_t *)&bp->bp_vend[0]) == htonl(BOOTP_VENDOR_MAGIC))
			dhcp_options_process((u8 *)&bp->bp_vend[4], bp);

		bootp_copy_net_params(bp); /* Store net params from reply */

		dhcp_start = get_time_ns();
		dhcp_send_request_packet(bp);

		break;
	case REQUESTING:
		debug ("%s: State REQUESTING\n", __func__);

		if (dhcp_message_type((u8 *)bp->bp_vend) == DHCP_ACK ) {
			if (net_read_uint32((uint32_t *)&bp->bp_vend[0]) == htonl(BOOTP_VENDOR_MAGIC))
				dhcp_options_process((u8 *)&bp->bp_vend[4], bp);
			bootp_copy_net_params(bp); /* Store net params from reply */
			dhcp_state = BOUND;
			puts ("DHCP client bound to address ");
			print_IPaddr(net_get_ip());
			putchar('\n');
			return;
		}
		break;
	default:
		debug("%s: INVALID STATE\n", __func__);
		break;
	}
}

static void dhcp_reset_env(void)
{
	struct dhcp_opt *opt;
	int i;

	for (i = 0; i < ARRAY_SIZE(dhcp_options); i++) {
		opt = &dhcp_options[i];
		if (!opt->barebox_var_name || opt->copy_only_if_valid)
			continue;

		if (IS_ENABLED(CONFIG_ENVIRONMENT_VARIABLES))
			setenv(opt->barebox_var_name, "");
		if (opt->barebox_dhcp_global && IS_ENABLED(CONFIG_GLOBALVAR))
			dhcp_set_barebox_global(opt->barebox_dhcp_global, "");
	}
}

int dhcp(int retries, struct dhcp_req_param *param)
{
	int ret = 0;

	dhcp_reset_env();

	dhcp_set_param_data(DHCP_HOSTNAME, param->hostname);
	dhcp_set_param_data(DHCP_VENDOR_ID, param->vendor_id);
	dhcp_set_param_data(DHCP_CLIENT_ID, param->client_id);
	dhcp_set_param_data(DHCP_USER_CLASS, param->user_class);
	dhcp_set_param_data(DHCP_CLIENT_UUID, param->client_uuid);

	if (!retries)
		retries = DHCP_DEFAULT_RETRY;

	dhcp_con = net_udp_new(0xffffffff, PORT_BOOTPS, dhcp_handler, NULL);
	if (IS_ERR(dhcp_con)) {
		ret = PTR_ERR(dhcp_con);
		goto out;
	}

	ret = net_udp_bind(dhcp_con, PORT_BOOTPC);
	if (ret)
		goto out1;

	net_set_ip(0);

	dhcp_start = get_time_ns();
	ret = bootp_request(); /* Basically same as BOOTP */
	if (ret)
		goto out1;

	while (dhcp_state != BOUND) {
		if (ctrlc()) {
			ret = -EINTR;
			goto out1;
		}
		if (!retries) {
			ret = -ETIMEDOUT;
			goto out1;
		}
		net_poll();
		if (is_timeout(dhcp_start, 3 * SECOND)) {
			dhcp_start = get_time_ns();
			printf("T ");
			ret = bootp_request();
			/* no need to check if retries > 0 as we check if != 0 */
			retries--;
			if (ret)
				goto out1;
		}
	}

	if (dhcp_tftpname[0] != 0) {
		IPaddr_t tftpserver = resolv(dhcp_tftpname);
		if (tftpserver)
			net_set_serverip(tftpserver);
	}

out1:
	net_unregister(dhcp_con);
out:
	if (ret)
		debug("dhcp failed: %s\n", strerror(-ret));

	return ret;
}

#ifdef CONFIG_GLOBALVAR
static void dhcp_global_add(const char *var)
{
	char *var_global = asprintf("dhcp.%s", var);

	if (!var_global)
		return;

	globalvar_add_simple(var_global, NULL);
	free(var_global);
}

static int dhcp_global_init(void)
{
	struct dhcp_opt *opt;
	int i;

	for (i = 0; i < ARRAY_SIZE(dhcp_options); i++) {
		opt = &dhcp_options[i];

		if (!opt->barebox_dhcp_global)
			continue;

		dhcp_global_add(opt->barebox_dhcp_global);
	}

	return 0;
}
late_initcall(dhcp_global_init);

BAREBOX_MAGICVAR_NAMED(global_dhcp_bootfile, global.dhcp.bootfile, "bootfile returned from DHCP request");
BAREBOX_MAGICVAR_NAMED(global_dhcp_rootpath, global.dhcp.rootpath, "rootpath returned from DHCP request");
BAREBOX_MAGICVAR_NAMED(global_dhcp_vendor_id, global.dhcp.vendor_id, "vendor id to send to the DHCP server");
BAREBOX_MAGICVAR_NAMED(global_dhcp_client_uuid, global.dhcp.client_uuid, "client uuid to send to the DHCP server");
BAREBOX_MAGICVAR_NAMED(global_dhcp_client_id, global.dhcp.client_id, "client id to send to the DHCP server");
BAREBOX_MAGICVAR_NAMED(global_dhcp_user_class, global.dhcp.user_class, "user class to send to the DHCP server");
BAREBOX_MAGICVAR_NAMED(global_dhcp_tftp_server_name, global.dhcp.tftp_server_name, "TFTP server Name returned from DHCP request");
BAREBOX_MAGICVAR_NAMED(global_dhcp_oftree_file, global.dhcp.oftree_file, "OF tree returned from DHCP request (option 224)");
BAREBOX_MAGICVAR_NAMED(global_dhcp_retries, global.dhcp.retries, "retry limit");
#endif