bootp.c@ 44528

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1	/* $Id: bootp.c 44528 2013-02-04 14:27:54Z vboxsync $ */
2	/** @file
3	* NAT - BOOTP/DHCP server emulation.
4	*/
5
6	/*
7	* Copyright (C) 2006-2012 Oracle Corporation
8	*
9	* This file is part of VirtualBox Open Source Edition (OSE), as
10	* available from http://www.virtualbox.org. This file is free software;
11	* you can redistribute it and/or modify it under the terms of the GNU
12	* General Public License (GPL) as published by the Free Software
13	* Foundation, in version 2 as it comes in the "COPYING" file of the
14	* VirtualBox OSE distribution. VirtualBox OSE is distributed in the
15	* hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
16	*/
17
18	/*
19	* This code is based on:
20	*
21	* QEMU BOOTP/DHCP server
22	*
23	* Copyright (c) 2004 Fabrice Bellard
24	*
25	* Permission is hereby granted, free of charge, to any person obtaining a copy
26	* of this software and associated documentation files (the "Software"), to deal
27	* in the Software without restriction, including without limitation the rights
28	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
29	* copies of the Software, and to permit persons to whom the Software is
30	* furnished to do so, subject to the following conditions:
31	*
32	* The above copyright notice and this permission notice shall be included in
33	* all copies or substantial portions of the Software.
34	*
35	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
36	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
37	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
38	* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
39	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
40	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
41	* THE SOFTWARE.
42	*/
43	#include <slirp.h>
44
45	/** Entry in the table of known DHCP clients. */
46	typedef struct
47	{
48	uint32_t xid;
49	bool allocated;
50	uint8_t macaddr[6];
51	struct in_addr addr;
52	int number;
53	} BOOTPClient;
54	/** Number of DHCP clients supported by NAT. */
55	#define NB_ADDR 16
56
57	#define bootp_clients ((BOOTPClient *)pData->pbootp_clients)
58
59	/* XXX: only DHCP is supported */
60	static const uint8_t rfc1533_cookie[] = { RFC1533_COOKIE };
61
62	static void bootp_reply(PNATState pData, struct mbuf *m0, int offReply, uint16_t flags);
63
64	static uint8_t dhcp_find_option(uint8_t vend, uint8_t tag)
65	{
66	uint8_t *q = vend;
67	uint8_t len;
68	/@todo magic validation /
69	q += 4; /magic/
70	while(*q != RFC1533_END)
71	{
72	if (*q == RFC1533_PAD)
73	continue;
74	if (*q == tag)
75	return q;
76	q++;
77	len = *q;
78	q += 1 + len;
79	}
80	return NULL;
81	}
82
83	static BOOTPClient *bc_alloc_client(PNATState pData)
84	{
85	int i;
86	LogFlowFuncEnter();
87	for (i = 0; i < NB_ADDR; i++)
88	{
89	if (!bootp_clients[i].allocated)
90	{
91	BOOTPClient *bc;
92
93	bc = &bootp_clients[i];
94	memset(bc, 0, sizeof(BOOTPClient));
95	bc->allocated = 1;
96	bc->number = i;
97	LogFlowFunc(("LEAVE: bc:%d\n", bc->number));
98	return bc;
99	}
100	}
101	LogFlowFunc(("LEAVE: NULL\n"));
102	return NULL;
103	}
104
105	static BOOTPClient get_new_addr(PNATState pData, struct in_addr paddr)
106	{
107	BOOTPClient *bc;
108	LogFlowFuncEnter();
109	bc = bc_alloc_client(pData);
110	if (!bc)
111	return NULL;
112
113	paddr->s_addr = RT_H2N_U32(RT_N2H_U32(pData->special_addr.s_addr) \| (bc->number + START_ADDR));
114	bc->addr.s_addr = paddr->s_addr;
115	LogFlowFunc(("LEAVE: paddr:%RTnaipv4, bc:%d\n", paddr->s_addr, bc->number));
116	return bc;
117	}
118
119	static int release_addr(PNATState pData, struct in_addr *paddr)
120	{
121	unsigned i;
122	for (i = 0; i < NB_ADDR; i++)
123	{
124	if (paddr->s_addr == bootp_clients[i].addr.s_addr)
125	{
126	memset(&bootp_clients[i], 0, sizeof(BOOTPClient));
127	return VINF_SUCCESS;
128	}
129	}
130	return VERR_NOT_FOUND;
131	}
132
133	/*
134	* from RFC 2131 4.3.1
135	* Field DHCPOFFER DHCPACK DHCPNAK
136	* ----- --------- ------- -------
137	* 'op' BOOTREPLY BOOTREPLY BOOTREPLY
138	* 'htype' (From "Assigned Numbers" RFC)
139	* 'hlen' (Hardware address length in octets)
140	* 'hops' 0 0 0
141	* 'xid' 'xid' from client 'xid' from client 'xid' from client
142	* DHCPDISCOVER DHCPREQUEST DHCPREQUEST
143	* message message message
144	* 'secs' 0 0 0
145	* 'ciaddr' 0 'ciaddr' from 0
146	* DHCPREQUEST or 0
147	* 'yiaddr' IP address offered IP address 0
148	* to client assigned to client
149	* 'siaddr' IP address of next IP address of next 0
150	* bootstrap server bootstrap server
151	* 'flags' 'flags' from 'flags' from 'flags' from
152	* client DHCPDISCOVER client DHCPREQUEST client DHCPREQUEST
153	* message message message
154	* 'giaddr' 'giaddr' from 'giaddr' from 'giaddr' from
155	* client DHCPDISCOVER client DHCPREQUEST client DHCPREQUEST
156	* message message message
157	* 'chaddr' 'chaddr' from 'chaddr' from 'chaddr' from
158	* client DHCPDISCOVER client DHCPREQUEST client DHCPREQUEST
159	* message message message
160	* 'sname' Server host name Server host name (unused)
161	* or options or options
162	* 'file' Client boot file Client boot file (unused)
163	* name or options name or options
164	* 'options' options options
165	*
166	* Option DHCPOFFER DHCPACK DHCPNAK
167	* ------ --------- ------- -------
168	* Requested IP address MUST NOT MUST NOT MUST NOT
169	* IP address lease time MUST MUST (DHCPREQUEST) MUST NOT
170	* MUST NOT (DHCPINFORM)
171	* Use 'file'/'sname' fields MAY MAY MUST NOT
172	* DHCP message type DHCPOFFER DHCPACK DHCPNAK
173	* Parameter request list MUST NOT MUST NOT MUST NOT
174	* Message SHOULD SHOULD SHOULD
175	* Client identifier MUST NOT MUST NOT MAY
176	* Vendor class identifier MAY MAY MAY
177	* Server identifier MUST MUST MUST
178	* Maximum message size MUST NOT MUST NOT MUST NOT
179	* All others MAY MAY MUST NOT
180	*/
181	static BOOTPClient find_addr(PNATState pData, struct in_addr paddr, const uint8_t *macaddr)
182	{
183	int i;
184
185	LogFlowFunc(("macaddr:%RTmac\n", macaddr));
186	for (i = 0; i < NB_ADDR; i++)
187	{
188	if ( memcmp(macaddr, bootp_clients[i].macaddr, ETH_ALEN) == 0
189	&& bootp_clients[i].allocated != 0)
190	{
191	BOOTPClient *bc;
192
193	bc = &bootp_clients[i];
194	bc->allocated = 1;
195	paddr->s_addr = RT_H2N_U32(RT_N2H_U32(pData->special_addr.s_addr) \| (i + START_ADDR));
196	LogFlowFunc(("LEAVE: paddr:%RTnaipv4 bc:%d\n", paddr->s_addr, bc->number));
197	return bc;
198	}
199	}
200	LogFlowFunc(("LEAVE: NULL\n"));
201	return NULL;
202	}
203
204	static struct mbuf dhcp_create_msg(PNATState pData, struct bootp_t bp, struct mbuf *m, uint8_t type)
205	{
206	struct bootp_t *rbp;
207	struct ethhdr *eh;
208	uint8_t *q;
209
210	eh = mtod(m, struct ethhdr *);
211	memcpy(eh->h_source, bp->bp_hwaddr, ETH_ALEN); /* XXX: if_encap just swap source with dest */
212
213	m->m_data += if_maxlinkhdr; /reserve ether header /
214
215	rbp = mtod(m, struct bootp_t *);
216	memset(rbp, 0, sizeof(struct bootp_t));
217	rbp->bp_op = BOOTP_REPLY;
218	rbp->bp_xid = bp->bp_xid; /* see table 3 of rfc2131*/
219	rbp->bp_flags = bp->bp_flags; /* figure 2 of rfc2131 */
220	rbp->bp_giaddr.s_addr = bp->bp_giaddr.s_addr;
221	#if 0 /check flags/
222	saddr.sin_port = RT_H2N_U16_C(BOOTP_SERVER);
223	daddr.sin_port = RT_H2N_U16_C(BOOTP_CLIENT);
224	#endif
225	rbp->bp_htype = 1;
226	rbp->bp_hlen = 6;
227	memcpy(rbp->bp_hwaddr, bp->bp_hwaddr, 6);
228
229	memcpy(rbp->bp_vend, rfc1533_cookie, 4); /* cookie */
230	q = rbp->bp_vend;
231	q += 4;
232	*q++ = RFC2132_MSG_TYPE;
233	*q++ = 1;
234	*q++ = type;
235
236	return m;
237	}
238
239	static int dhcp_do_ack_offer(PNATState pData, struct mbuf m, BOOTPClient bc, int fDhcpRequest)
240	{
241	struct bootp_t *rbp = NULL;
242	uint8_t *q;
243	struct in_addr saddr;
244	int val;
245
246	struct dns_entry *de = NULL;
247	struct dns_domain_entry *dd = NULL;
248	int added = 0;
249	uint8_t *q_dns_header = NULL;
250	uint32_t lease_time = RT_H2N_U32_C(LEASE_TIME);
251	uint32_t netmask = RT_H2N_U32(pData->netmask);
252
253	rbp = mtod(m, struct bootp_t *);
254	q = &rbp->bp_vend[0];
255	q += 7; /* !cookie rfc 2132 + TYPE*/
256
257	/DHCP Offer specific/
258	/*
259	* we're care in built-in tftp server about existence/validness of the boot file.
260	*/
261	if (bootp_filename)
262	RTStrPrintf((char*)rbp->bp_file, sizeof(rbp->bp_file), "%s", bootp_filename);
263
264	Log(("NAT: DHCP: bp_file:%s\n", &rbp->bp_file));
265	/* Address/port of the DHCP server. */
266	rbp->bp_yiaddr = bc->addr; /* Client IP address */
267	Log(("NAT: DHCP: bp_yiaddr:%RTnaipv4\n", rbp->bp_yiaddr));
268	rbp->bp_siaddr = pData->tftp_server; /* Next Server IP address, i.e. TFTP */
269	Log(("NAT: DHCP: bp_siaddr:%RTnaipv4\n", rbp->bp_siaddr));
270	if (fDhcpRequest)
271	{
272	rbp->bp_ciaddr.s_addr = bc->addr.s_addr; /* Client IP address */
273	}
274	saddr.s_addr = RT_H2N_U32(RT_N2H_U32(pData->special_addr.s_addr) \| CTL_ALIAS);
275	Log(("NAT: DHCP: s_addr:%RTnaipv4\n", saddr));
276
277	#define FILL_BOOTP_EXT(q, tag, len, pvalue) \
278	do { \
279	struct bootp_ext be = (struct bootp_ext )(q); \
280	be->bpe_tag = (tag); \
281	be->bpe_len = (len); \
282	memcpy(&be[1], (pvalue), (len)); \
283	(q) = (uint8_t *)(&be[1]) + (len); \
284	}while(0)
285	/* appending another value to tag, calculates len of whole block*/
286	#define FILL_BOOTP_APP(head, q, tag, len, pvalue) \
287	do { \
288	struct bootp_ext be = (struct bootp_ext )(head); \
289	memcpy(q, (pvalue), (len)); \
290	(q) += (len); \
291	Assert(be->bpe_tag == (tag)); \
292	be->bpe_len += (len); \
293	}while(0)
294
295
296	FILL_BOOTP_EXT(q, RFC1533_NETMASK, 4, &netmask);
297	FILL_BOOTP_EXT(q, RFC1533_GATEWAY, 4, &saddr);
298
299	if (pData->fUseDnsProxy \|\| pData->fUseHostResolver)
300	{
301	uint32_t addr = RT_H2N_U32(RT_N2H_U32(pData->special_addr.s_addr) \| CTL_DNS);
302	FILL_BOOTP_EXT(q, RFC1533_DNS, 4, &addr);
303	}
304	else
305	{
306	if (!TAILQ_EMPTY(&pData->pDnsList))
307	{
308	de = TAILQ_LAST(&pData->pDnsList, dns_list_head);
309	q_dns_header = q;
310	FILL_BOOTP_EXT(q, RFC1533_DNS, 4, &de->de_addr.s_addr);
311	}
312
313	TAILQ_FOREACH_REVERSE(de, &pData->pDnsList, dns_list_head, de_list)
314	{
315	if (TAILQ_LAST(&pData->pDnsList, dns_list_head) == de)
316	continue; /* first value with head we've ingected before */
317	FILL_BOOTP_APP(q_dns_header, q, RFC1533_DNS, 4, &de->de_addr.s_addr);
318	}
319	}
320	if (pData->fPassDomain && !pData->fUseHostResolver)
321	{
322	LIST_FOREACH(dd, &pData->pDomainList, dd_list)
323	{
324
325	if (dd->dd_pszDomain == NULL)
326	continue;
327	/* never meet valid separator here in RFC1533*/
328	if (added != 0)
329	FILL_BOOTP_EXT(q, RFC1533_DOMAINNAME, 1, ",");
330	else
331	added = 1;
332	val = (int)strlen(dd->dd_pszDomain);
333	FILL_BOOTP_EXT(q, RFC1533_DOMAINNAME, val, dd->dd_pszDomain);
334	}
335	}
336
337	FILL_BOOTP_EXT(q, RFC2132_LEASE_TIME, 4, &lease_time);
338
339	if (*slirp_hostname)
340	{
341	val = (int)strlen(slirp_hostname);
342	FILL_BOOTP_EXT(q, RFC1533_HOSTNAME, val, slirp_hostname);
343	}
344	slirp_arp_cache_update_or_add(pData, rbp->bp_yiaddr.s_addr, bc->macaddr);
345	return q - rbp->bp_vend; /return offset /
346	}
347
348	static int dhcp_send_nack(PNATState pData, struct bootp_t bp, BOOTPClient bc, struct mbuf *m)
349	{
350	NOREF(bc);
351
352	dhcp_create_msg(pData, bp, m, DHCPNAK);
353	return 7;
354	}
355
356	static int dhcp_send_ack(PNATState pData, struct bootp_t bp, BOOTPClient bc, struct mbuf *m, int fDhcpRequest)
357	{
358	int offReply = 0; /* boot_reply will fill general options and add END before sending response */
359
360	dhcp_create_msg(pData, bp, m, DHCPACK);
361	offReply = dhcp_do_ack_offer(pData, m, bc, fDhcpRequest);
362	return offReply;
363	}
364
365	static int dhcp_send_offer(PNATState pData, struct bootp_t bp, BOOTPClient bc, struct mbuf *m)
366	{
367	int offReply = 0; /* boot_reply will fill general options and add END before sending response */
368
369	dhcp_create_msg(pData, bp, m, DHCPOFFER);
370	offReply = dhcp_do_ack_offer(pData, m, bc, /* fDhcpRequest=*/ 0);
371	return offReply;
372	}
373
374	/**
375	* decoding client messages RFC2131 (4.3.6)
376	* ---------------------------------------------------------------------
377	* \| \|INIT-REBOOT \|SELECTING \|RENEWING \|REBINDING \|
378	* ---------------------------------------------------------------------
379	* \|broad/unicast \|broadcast \|broadcast \|unicast \|broadcast \|
380	* \|server-ip \|MUST NOT \|MUST \|MUST NOT \|MUST NOT \|
381	* \|requested-ip \|MUST \|MUST \|MUST NOT \|MUST NOT \|
382	* \|ciaddr \|zero \|zero \|IP address \|IP address\|
383	* ---------------------------------------------------------------------
384	*
385	*/
386
387	enum DHCP_REQUEST_STATES
388	{
389	INIT_REBOOT,
390	SELECTING,
391	RENEWING,
392	REBINDING,
393	NONE
394	};
395
396	static int dhcp_decode_request(PNATState pData, struct bootp_t bp, struct mbuf m)
397	{
398	BOOTPClient *bc = NULL;
399	struct in_addr daddr;
400	int offReply;
401	uint8_t *req_ip = NULL;
402	uint8_t *server_ip = NULL;
403	uint32_t ui32;
404	enum DHCP_REQUEST_STATES dhcp_stat = NONE;
405
406	/* need to understand which type of request we get */
407	req_ip = dhcp_find_option(&bp->bp_vend[0], RFC2132_REQ_ADDR);
408	server_ip = dhcp_find_option(&bp->bp_vend[0], RFC2132_SRV_ID);
409
410	bc = find_addr(pData, &daddr, bp->bp_hwaddr);
411
412	if (server_ip != NULL)
413	{
414	/* selecting */
415	if (!bc)
416	{
417	LogRel(("NAT: DHCP no IP was allocated\n"));
418	return -1;
419	}
420
421	if ( !req_ip
422	\|\| bp->bp_ciaddr.s_addr != INADDR_ANY)
423	{
424	LogRel(("NAT: Invalid SELECTING request\n"));
425	return -1; /* silently ignored */
426	}
427	dhcp_stat = SELECTING;
428	Assert((bp->bp_ciaddr.s_addr == INADDR_ANY));
429	#if 0
430	/* DSL xid in request differ from offer */
431	Assert((bp->bp_xid == bc->xid));
432	#endif
433	}
434	else
435	{
436	if (req_ip != NULL)
437	{
438	/* init-reboot */
439	dhcp_stat = INIT_REBOOT;
440	}
441	else
442	{
443	/* table 4 of rfc2131 */
444	if (bp->bp_flags & RT_H2N_U16_C(DHCP_FLAGS_B))
445	dhcp_stat = REBINDING;
446	else
447	dhcp_stat = RENEWING;
448	}
449	}
450
451	/?? renewing ??/
452	switch (dhcp_stat)
453	{
454	case RENEWING:
455	/**
456	* decoding client messages RFC2131 (4.3.6)
457	* ------------------------------
458	* \| \|RENEWING \|
459	* ------------------------------
460	* \|broad/unicast \|unicast \|
461	* \|server-ip \|MUST NOT \|
462	* \|requested-ip \|MUST NOT \|
463	* \|ciaddr \|IP address \|
464	* ------------------------------
465	*/
466	Assert((server_ip == NULL && req_ip == NULL && bp->bp_ciaddr.s_addr != INADDR_ANY));
467	if ( server_ip
468	\|\| req_ip
469	\|\| bp->bp_ciaddr.s_addr == INADDR_ANY)
470	{
471	LogRel(("NAT: invalid RENEWING dhcp request\n"));
472	return -1; /* silent ignorance */
473	}
474	if (bc != NULL)
475	{
476	Assert((bc->addr.s_addr == bp->bp_ciaddr.s_addr));
477	/if it already here well just do ack, we aren't aware of dhcp time expiration/
478	}
479	else
480	{
481	if ((bp->bp_ciaddr.s_addr & RT_H2N_U32(pData->netmask)) != pData->special_addr.s_addr)
482	{
483	LogRel(("NAT: Client %RTnaipv4 requested IP -- sending NAK\n", bp->bp_ciaddr));
484	offReply = dhcp_send_nack(pData, bp, bc, m);
485	return offReply;
486	}
487
488	bc = bc_alloc_client(pData);
489	if (!bc)
490	{
491	LogRel(("NAT: can't alloc address. RENEW has been silently ignored.\n"));
492	return -1;
493	}
494
495	Assert((bp->bp_hlen == ETH_ALEN));
496	memcpy(bc->macaddr, bp->bp_hwaddr, bp->bp_hlen);
497	bc->addr.s_addr = bp->bp_ciaddr.s_addr;
498	}
499	break;
500
501	case INIT_REBOOT:
502	/**
503	* decoding client messages RFC2131 (4.3.6)
504	* ------------------------------
505	* \| \|INIT-REBOOT \|
506	* ------------------------------
507	* \|broad/unicast \|broadcast \|
508	* \|server-ip \|MUST NOT \|
509	* \|requested-ip \|MUST \|
510	* \|ciaddr \|zero \|
511	* ------------------------------
512	*
513	*/
514	Assert(server_ip == NULL);
515	Assert(req_ip != NULL);
516	if ( server_ip
517	\|\| !req_ip
518	\|\| bp->bp_ciaddr.s_addr != INADDR_ANY)
519	{
520	LogRel(("NAT: Invalid INIT-REBOOT dhcp request\n"));
521	return -1; /* silently ignored */
522	}
523	ui32 = (uint32_t )(req_ip + 2);
524	if ((ui32 & RT_H2N_U32(pData->netmask)) != pData->special_addr.s_addr)
525	{
526	LogRel(("NAT: address %RTnaipv4 has been requested -- sending NAK\n", ui32));
527	offReply = dhcp_send_nack(pData, bp, bc, m);
528	return offReply;
529	}
530
531	bc = bc_alloc_client(pData);
532	if (!bc)
533	{
534	LogRel(("NAT: can't alloc address. RENEW has been silently ignored\n"));
535	return -1;
536	}
537	Assert((bp->bp_hlen == ETH_ALEN));
538	memcpy(bc->macaddr, bp->bp_hwaddr, bp->bp_hlen);
539	bc->addr.s_addr = ui32;
540	break;
541
542	case NONE:
543	Assert((dhcp_stat != NONE));
544	if (dhcp_stat == REBINDING)
545	LogRel(("NAT: REBINDING state isn't impemented\n"));
546	else if (dhcp_stat == SELECTING)
547	LogRel(("NAT: SELECTING state isn't impemented\n"));
548	return -1;
549
550	default:
551	break;
552	}
553
554	LogRel(("NAT: DHCP offered IP address %RTnaipv4\n", bc->addr));
555	offReply = dhcp_send_ack(pData, bp, bc, m, /* fDhcpRequest=*/ 1);
556	return offReply;
557	}
558
559	static int dhcp_decode_discover(PNATState pData, struct bootp_t bp, int fDhcpDiscover, struct mbuf m)
560	{
561	BOOTPClient *bc;
562	struct in_addr daddr;
563	int offReply;
564
565	if (fDhcpDiscover)
566	{
567	bc = find_addr(pData, &daddr, bp->bp_hwaddr);
568	if (!bc)
569	{
570	bc = get_new_addr(pData, &daddr);
571	if (!bc)
572	{
573	LogRel(("NAT: DHCP no IP address left\n"));
574	Log(("no address left\n"));
575	return -1;
576	}
577	memcpy(bc->macaddr, bp->bp_hwaddr, 6);
578	}
579
580	bc->xid = bp->bp_xid;
581	LogRel(("NAT: DHCP offered IP address %RTnaipv4\n", bc->addr));
582	offReply = dhcp_send_offer(pData, bp, bc, m);
583	return offReply;
584	}
585	else
586	{
587	bc = find_addr(pData, &daddr, bp->bp_hwaddr);
588	if (!bc)
589	{
590	LogRel(("NAT: DHCP Inform was ignored no boot client was found\n"));
591	return -1;
592	}
593
594	LogRel(("NAT: DHCP offered IP address %RTnaipv4\n", bc->addr));
595	offReply = dhcp_send_ack(pData, bp, bc, m, /* fDhcpRequest=*/ 0);
596	return offReply;
597	}
598
599	return -1;
600	}
601
602	static int dhcp_decode_release(PNATState pData, struct bootp_t *bp)
603	{
604	int rc = release_addr(pData, &bp->bp_ciaddr);
605	LogRel(("NAT: %s %RTnaipv4\n",
606	RT_SUCCESS(rc) ? "DHCP released IP address" : "Ignored DHCP release for IP address",
607	&bp->bp_ciaddr));
608	return 0;
609	}
610	/**
611	* fields for discovering t
612	* Field DHCPDISCOVER DHCPREQUEST DHCPDECLINE,
613	* DHCPINFORM DHCPRELEASE
614	* ----- ------------ ----------- -----------
615	* 'op' BOOTREQUEST BOOTREQUEST BOOTREQUEST
616	* 'htype' (From "Assigned Numbers" RFC)
617	* 'hlen' (Hardware address length in octets)
618	* 'hops' 0 0 0
619	* 'xid' selected by client 'xid' from server selected by
620	* DHCPOFFER message client
621	* 'secs' 0 or seconds since 0 or seconds since 0
622	* DHCP process started DHCP process started
623	* 'flags' Set 'BROADCAST' Set 'BROADCAST' 0
624	* flag if client flag if client
625	* requires broadcast requires broadcast
626	* reply reply
627	* 'ciaddr' 0 (DHCPDISCOVER) 0 or client's 0 (DHCPDECLINE)
628	* client's network address client's network
629	* network address (BOUND/RENEW/REBIND) address
630	* (DHCPINFORM) (DHCPRELEASE)
631	* 'yiaddr' 0 0 0
632	* 'siaddr' 0 0 0
633	* 'giaddr' 0 0 0
634	* 'chaddr' client's hardware client's hardware client's hardware
635	* address address address
636	* 'sname' options, if options, if (unused)
637	* indicated in indicated in
638	* 'sname/file' 'sname/file'
639	* option; otherwise option; otherwise
640	* unused unused
641	* 'file' options, if options, if (unused)
642	* indicated in indicated in
643	* 'sname/file' 'sname/file'
644	* option; otherwise option; otherwise
645	* unused unused
646	* 'options' options options (unused)
647	* Requested IP address MAY MUST (in MUST
648	* (DISCOVER) SELECTING or (DHCPDECLINE),
649	* MUST NOT INIT-REBOOT) MUST NOT
650	* (INFORM) MUST NOT (in (DHCPRELEASE)
651	* BOUND or
652	* RENEWING)
653	* IP address lease time MAY MAY MUST NOT
654	* (DISCOVER)
655	* MUST NOT
656	* (INFORM)
657	* Use 'file'/'sname' fields MAY MAY MAY
658	* DHCP message type DHCPDISCOVER/ DHCPREQUEST DHCPDECLINE/
659	* DHCPINFORM DHCPRELEASE
660	* Client identifier MAY MAY MAY
661	* Vendor class identifier MAY MAY MUST NOT
662	* Server identifier MUST NOT MUST (after MUST
663	* SELECTING)
664	* MUST NOT (after
665	* INIT-REBOOT,
666	* BOUND, RENEWING
667	* or REBINDING)
668	* Parameter request list MAY MAY MUST NOT
669	* Maximum message size MAY MAY MUST NOT
670	* Message SHOULD NOT SHOULD NOT SHOULD
671	* Site-specific MAY MAY MUST NOT
672	* All others MAY MAY MUST NOT
673	*
674	*/
675	static void dhcp_decode(PNATState pData, struct bootp_t bp, const uint8_t buf, int size)
676	{
677	const uint8_t *pu8RawDhcpObject;
678	int rc;
679	struct in_addr req_ip;
680	int fDhcpDiscover = 0;
681	uint8_t *parameter_list = NULL;
682	struct mbuf *m = NULL;
683
684	pu8RawDhcpObject = buf;
685	if (size < 5)
686	return;
687
688	if (memcmp(pu8RawDhcpObject, rfc1533_cookie, 4) != 0)
689	return;
690
691	/* note: pu8RawDhcpObject doesn't point to parameter buf */
692	pu8RawDhcpObject = dhcp_find_option(bp->bp_vend, RFC2132_MSG_TYPE);
693	Assert(pu8RawDhcpObject);
694	if (!pu8RawDhcpObject)
695	return;
696	/*
697	* We're going update dns list at least once per DHCP transaction (!not on every operation
698	* within transaction), assuming that transaction can't be longer than 1 min.
699	*/
700	if ( !pData->fUseHostResolver
701	&& ( pData->dnsLastUpdate == 0
702	\|\| curtime - pData->dnsLastUpdate > 60 * 1000)) /* one minute*/
703	{
704	uint8_t i = 2; /* i = 0 - tag, i == 1 - length */
705	parameter_list = dhcp_find_option(&bp->bp_vend[0], RFC2132_PARAM_LIST);
706	for (;parameter_list && i < parameter_list[1]; ++i)
707	{
708	if (parameter_list[i] == RFC1533_DNS)
709	{
710	slirpReleaseDnsSettings(pData);
711	slirpInitializeDnsSettings(pData);
712	pData->dnsLastUpdate = curtime;
713	break;
714	}
715	}
716	}
717
718	m = m_getcl(pData, M_DONTWAIT, MT_HEADER, M_PKTHDR);
719	if (!m)
720	{
721	LogRel(("NAT: can't alocate memory for response!\n"));
722	return;
723	}
724
725	switch (*(pu8RawDhcpObject + 2))
726	{
727	case DHCPDISCOVER:
728	fDhcpDiscover = 1;
729	/* fall through */
730	case DHCPINFORM:
731	rc = dhcp_decode_discover(pData, bp, fDhcpDiscover, m);
732	if (rc > 0)
733	goto reply;
734	break;
735
736	case DHCPREQUEST:
737	rc = dhcp_decode_request(pData, bp, m);
738	if (rc > 0)
739	goto reply;
740	break;
741
742	case DHCPRELEASE:
743	dhcp_decode_release(pData, bp);
744	/* no reply required */
745	break;
746
747	case DHCPDECLINE:
748	/* note: pu8RawDhcpObject doesn't point to DHCP header, now it's expected it points
749	* to Dhcp Option RFC2132_REQ_ADDR
750	*/
751	pu8RawDhcpObject = dhcp_find_option(&bp->bp_vend[0], RFC2132_REQ_ADDR);
752	if (!pu8RawDhcpObject)
753	{
754	Log(("NAT: RFC2132_REQ_ADDR not found\n"));
755	break;
756	}
757	req_ip.s_addr = (uint32_t )(pu8RawDhcpObject + 2);
758	rc = bootp_cache_lookup_ether_by_ip(pData, req_ip.s_addr, NULL);
759	if (RT_FAILURE(rc))
760	{
761	/* Not registered */
762	BOOTPClient *bc;
763	bc = bc_alloc_client(pData);
764	Assert(bc);
765	if (!bc)
766	{
767	LogRel(("NAT: can't allocate bootp client object\n"));
768	break;
769	}
770	bc->addr.s_addr = req_ip.s_addr;
771	slirp_arp_who_has(pData, bc->addr.s_addr);
772	LogRel(("NAT: %RTnaipv4 has been already registered\n", req_ip));
773	}
774	/* no response required */
775	break;
776
777	default:
778	AssertMsgFailed(("unsupported DHCP message type"));
779	}
780	/* silently ignore */
781	m_freem(pData, m);
782	return;
783
784	reply:
785	bootp_reply(pData, m, rc, bp->bp_flags);
786	}
787
788	static void bootp_reply(PNATState pData, struct mbuf *m, int offReply, uint16_t flags)
789	{
790	struct sockaddr_in saddr, daddr;
791	struct bootp_t *rbp = NULL;
792	uint8_t *q = NULL;
793	int nack;
794	rbp = mtod(m, struct bootp_t *);
795	Assert((m));
796	Assert((rbp));
797	q = rbp->bp_vend;
798	nack = (q[6] == DHCPNAK);
799	q += offReply;
800
801	saddr.sin_addr.s_addr = RT_H2N_U32(RT_N2H_U32(pData->special_addr.s_addr) \| CTL_ALIAS);
802
803	FILL_BOOTP_EXT(q, RFC2132_SRV_ID, 4, &saddr.sin_addr);
804
805	q++ = RFC1533_END; / end of message */
806
807	m->m_pkthdr.header = mtod(m, void *);
808	m->m_len = sizeof(struct bootp_t)
809	- sizeof(struct ip)
810	- sizeof(struct udphdr);
811	m->m_data += sizeof(struct udphdr)
812	+ sizeof(struct ip);
813	if ( (flags & RT_H2N_U16_C(DHCP_FLAGS_B))
814	\|\| nack != 0)
815	daddr.sin_addr.s_addr = INADDR_BROADCAST;
816	else
817	daddr.sin_addr.s_addr = rbp->bp_yiaddr.s_addr; /unicast requested by client/
818	saddr.sin_port = RT_H2N_U16_C(BOOTP_SERVER);
819	daddr.sin_port = RT_H2N_U16_C(BOOTP_CLIENT);
820	udp_output2(pData, NULL, m, &saddr, &daddr, IPTOS_LOWDELAY);
821	}
822
823	void bootp_input(PNATState pData, struct mbuf *m)
824	{
825	struct bootp_t bp = mtod(m, struct bootp_t );
826
827	if (bp->bp_op == BOOTP_REQUEST)
828	dhcp_decode(pData, bp, bp->bp_vend, DHCP_OPT_LEN);
829	}
830
831	int bootp_cache_lookup_ip_by_ether(PNATState pData,const uint8_t* ether, uint32_t *pip)
832	{
833	int i;
834
835	if (!ether \|\| !pip)
836	return VERR_INVALID_PARAMETER;
837
838	for (i = 0; i < NB_ADDR; i++)
839	{
840	if ( bootp_clients[i].allocated
841	&& memcmp(bootp_clients[i].macaddr, ether, ETH_ALEN) == 0)
842	{
843	*pip = bootp_clients[i].addr.s_addr;
844	return VINF_SUCCESS;
845	}
846	}
847
848	*pip = INADDR_ANY;
849	return VERR_NOT_FOUND;
850	}
851
852	int bootp_cache_lookup_ether_by_ip(PNATState pData, uint32_t ip, uint8_t *ether)
853	{
854	int i;
855	for (i = 0; i < NB_ADDR; i++)
856	{
857	if ( bootp_clients[i].allocated
858	&& ip == bootp_clients[i].addr.s_addr)
859	{
860	if (ether != NULL)
861	memcpy(ether, bootp_clients[i].macaddr, ETH_ALEN);
862	return VINF_SUCCESS;
863	}
864	}
865
866	return VERR_NOT_FOUND;
867	}
868
869	/*
870	* Initialize dhcp server
871	* @returns 0 - if initialization is ok, non-zero otherwise
872	*/
873	int bootp_dhcp_init(PNATState pData)
874	{
875	pData->pbootp_clients = RTMemAllocZ(sizeof(BOOTPClient) * NB_ADDR);
876	if (!pData->pbootp_clients)
877	return VERR_NO_MEMORY;
878
879	return VINF_SUCCESS;
880	}
881
882	int bootp_dhcp_fini(PNATState pData)
883	{
884	if (pData->pbootp_clients != NULL)
885	RTMemFree(pData->pbootp_clients);
886
887	return VINF_SUCCESS;
888	}

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source: vbox/trunk/src/VBox/Devices/Network/slirp/bootp.c@ 44528

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