bootp.c@ 22103

Last change on this file since 22103 was 22103, checked in by vboxsync, 16 years ago
NAT: removing some todos
Property svn:eol-style set to `native`
File size: 24.8 KB

Line
1	/*
2	* QEMU BOOTP/DHCP server
3	*
4	* Copyright (c) 2004 Fabrice Bellard
5	*
6	* Permission is hereby granted, free of charge, to any person obtaining a copy
7	* of this software and associated documentation files (the "Software"), to deal
8	* in the Software without restriction, including without limitation the rights
9	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10	* copies of the Software, and to permit persons to whom the Software is
11	* furnished to do so, subject to the following conditions:
12	*
13	* The above copyright notice and this permission notice shall be included in
14	* all copies or substantial portions of the Software.
15	*
16	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19	* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22	* THE SOFTWARE.
23	*/
24	#include <slirp.h>
25
26	/* XXX: only DHCP is supported */
27
28	static const uint8_t rfc1533_cookie[] = { RFC1533_COOKIE };
29	static void bootp_reply(PNATState pData, struct mbuf *m0, int off, uint16_t flags);
30
31	static uint8_t dhcp_find_option(uint8_t vend, uint8_t tag)
32	{
33	uint8_t *q = vend;
34	uint8_t len;
35	/@todo magic validation /
36	q += 4; /magic/
37	while(*q != RFC1533_END)
38	{
39	if (*q == RFC1533_PAD)
40	continue;
41	if (*q == tag)
42	return q;
43	q++;
44	len = *q;
45	q += 1 + len;
46	}
47	return NULL;
48	}
49	static BOOTPClient *alloc_addr(PNATState pData)
50	{
51	int i;
52	for (i = 0; i < NB_ADDR; i++)
53	{
54	if (!bootp_clients[i].allocated)
55	{
56	BOOTPClient *bc;
57
58	bc = &bootp_clients[i];
59	memset(bc, 0, sizeof(BOOTPClient));
60	bc->allocated = 1;
61	bc->number = i;
62	return bc;
63	}
64	}
65	return NULL;
66	}
67	static BOOTPClient get_new_addr(PNATState pData, struct in_addr paddr)
68	{
69	BOOTPClient *bc;
70	bc = alloc_addr(pData);
71	if (bc == NULL)
72	return NULL;
73	paddr->s_addr = htonl(ntohl(special_addr.s_addr) \| (bc->number + START_ADDR));
74	bc->addr.s_addr = paddr->s_addr;
75	return bc;
76	return NULL;
77	}
78
79	static int release_addr(PNATState pData, struct in_addr *paddr)
80	{
81	unsigned i;
82	for (i = 0; i < NB_ADDR; i++)
83	{
84	if (paddr->s_addr == bootp_clients[i].addr.s_addr)
85	{
86	memset(&bootp_clients[i], 0, sizeof(BOOTPClient));
87	return 1;
88	}
89	}
90	return 0;
91	}
92
93	/*
94	* from RFC 2131 4.3.1
95	* Field DHCPOFFER DHCPACK DHCPNAK
96	* ----- --------- ------- -------
97	* 'op' BOOTREPLY BOOTREPLY BOOTREPLY
98	* 'htype' (From "Assigned Numbers" RFC)
99	* 'hlen' (Hardware address length in octets)
100	* 'hops' 0 0 0
101	* 'xid' 'xid' from client 'xid' from client 'xid' from client
102	* DHCPDISCOVER DHCPREQUEST DHCPREQUEST
103	* message message message
104	* 'secs' 0 0 0
105	* 'ciaddr' 0 'ciaddr' from 0
106	* DHCPREQUEST or 0
107	* 'yiaddr' IP address offered IP address 0
108	* to client assigned to client
109	* 'siaddr' IP address of next IP address of next 0
110	* bootstrap server bootstrap server
111	* 'flags' 'flags' from 'flags' from 'flags' from
112	* client DHCPDISCOVER client DHCPREQUEST client DHCPREQUEST
113	* message message message
114	* 'giaddr' 'giaddr' from 'giaddr' from 'giaddr' from
115	* client DHCPDISCOVER client DHCPREQUEST client DHCPREQUEST
116	* message message message
117	* 'chaddr' 'chaddr' from 'chaddr' from 'chaddr' from
118	* client DHCPDISCOVER client DHCPREQUEST client DHCPREQUEST
119	* message message message
120	* 'sname' Server host name Server host name (unused)
121	* or options or options
122	* 'file' Client boot file Client boot file (unused)
123	* name or options name or options
124	* 'options' options options
125	*
126	* Option DHCPOFFER DHCPACK DHCPNAK
127	* ------ --------- ------- -------
128	* Requested IP address MUST NOT MUST NOT MUST NOT
129	* IP address lease time MUST MUST (DHCPREQUEST) MUST NOT
130	* MUST NOT (DHCPINFORM)
131	* Use 'file'/'sname' fields MAY MAY MUST NOT
132	* DHCP message type DHCPOFFER DHCPACK DHCPNAK
133	* Parameter request list MUST NOT MUST NOT MUST NOT
134	* Message SHOULD SHOULD SHOULD
135	* Client identifier MUST NOT MUST NOT MAY
136	* Vendor class identifier MAY MAY MAY
137	* Server identifier MUST MUST MUST
138	* Maximum message size MUST NOT MUST NOT MUST NOT
139	* All others MAY MAY MUST NOT
140	*/
141	static BOOTPClient find_addr(PNATState pData, struct in_addr paddr, const uint8_t *macaddr)
142	{
143	int i;
144
145	for (i = 0; i < NB_ADDR; i++)
146	{
147	if (!memcmp(macaddr, bootp_clients[i].macaddr, 6))
148	{
149	BOOTPClient *bc;
150
151	bc = &bootp_clients[i];
152	bc->allocated = 1;
153	paddr->s_addr = htonl(ntohl(special_addr.s_addr) \| (i + START_ADDR));
154	return bc;
155	}
156	}
157	return NULL;
158	}
159
160	static struct mbuf dhcp_create_msg(PNATState pData, struct bootp_t bp, struct mbuf *m, uint8_t type)
161	{
162	struct bootp_t *rbp;
163	struct ethhdr *eh;
164	uint8_t *q;
165
166	rbp = mtod(m, struct bootp_t *);
167	memset(rbp, 0, sizeof(struct bootp_t));
168	eh = mtod(m, struct ethhdr *);
169	memcpy(eh->h_source, bp->bp_hwaddr, ETH_ALEN); /* XXX: if_encap just swap source with dest*/
170	m->m_data += if_maxlinkhdr; /reserve ether header /
171	rbp = mtod(m, struct bootp_t *);
172	rbp->bp_op = BOOTP_REPLY;
173	rbp->bp_xid = bp->bp_xid; /* see table 3 of rfc2131*/
174	rbp->bp_flags = bp->bp_flags;
175	rbp->bp_giaddr.s_addr = bp->bp_giaddr.s_addr;
176	#if 0 /check flags/
177	saddr.sin_port = htons(BOOTP_SERVER);
178	daddr.sin_port = htons(BOOTP_CLIENT);
179	#endif
180	rbp->bp_htype = 1;
181	rbp->bp_hlen = 6;
182	memcpy(rbp->bp_hwaddr, bp->bp_hwaddr, 6);
183
184	memcpy(rbp->bp_vend, rfc1533_cookie, 4); /* cookie */
185	q = rbp->bp_vend;
186	q += 4;
187	*q++ = RFC2132_MSG_TYPE;
188	*q++ = 1;
189	*q++ = type;
190
191	return m;
192	}
193
194	static int dhcp_do_ack_offer(PNATState pData, struct mbuf m, BOOTPClient bc, int is_from_request)
195	{
196	int off = 0;
197	struct bootp_t *rbp = NULL;
198	uint8_t *q;
199	struct in_addr saddr;
200	int val;
201
202	struct dns_entry *de = NULL;
203	struct dns_domain_entry *dd = NULL;
204	int added = 0;
205	uint8_t *q_dns_header = NULL;
206	uint32_t lease_time = htonl(LEASE_TIME);
207	uint32_t netmask = htonl(pData->netmask);
208
209	rbp = mtod(m, struct bootp_t *);
210	q = &rbp->bp_vend[0];
211	q += 7; /* !cookie rfc 2132 + TYPE*/
212
213	/DHCP Offer specific/
214	if ( tftp_prefix
215	&& RTDirExists(tftp_prefix)
216	&& bootp_filename)
217	RTStrPrintf((char*)rbp->bp_file, sizeof(rbp->bp_file), "%s", bootp_filename);
218
219	Log(("NAT: DHCP: bp_file:%s\n", &rbp->bp_file));
220	/* Address/port of the DHCP server. */
221	rbp->bp_yiaddr = bc->addr; /* Client IP address */
222	Log(("NAT: DHCP: bp_yiaddr:%R[IP4]\n", &rbp->bp_yiaddr));
223	rbp->bp_siaddr = pData->tftp_server; /* Next Server IP address, i.e. TFTP */
224	Log(("NAT: DHCP: bp_siaddr:%R[IP4]\n", &rbp->bp_siaddr));
225	if (is_from_request)
226	{
227	rbp->bp_ciaddr.s_addr = bc->addr.s_addr; /* Client IP address */
228	}
229	#ifndef VBOX_WITH_NAT_SERVICE
230	saddr.s_addr = htonl(ntohl(special_addr.s_addr) \| CTL_ALIAS);
231	#else
232	saddr.s_addr = special_addr.s_addr;
233	#endif
234	Log(("NAT: DHCP: s_addr:%R[IP4]\n", &saddr));
235
236	#define FILL_BOOTP_EXT(q, tag, len, pvalue) \
237	do { \
238	struct bootp_ext be = (struct bootp_ext )(q); \
239	be->bpe_tag = (tag); \
240	be->bpe_len = (len); \
241	memcpy(&be[1], (pvalue), (len)); \
242	(q) = (uint8_t *)(&be[1]) + (len); \
243	}while(0)
244	/* appending another value to tag, calculates len of whole block*/
245	#define FILL_BOOTP_APP(head, q, tag, len, pvalue) \
246	do { \
247	struct bootp_ext be = (struct bootp_ext )(head); \
248	memcpy(q, (pvalue), (len)); \
249	(q) += (len); \
250	Assert(be->bpe_tag == (tag)); \
251	be->bpe_len += (len); \
252	}while(0)
253
254
255
256	FILL_BOOTP_EXT(q, RFC1533_NETMASK, 4, &netmask);
257	FILL_BOOTP_EXT(q, RFC1533_GATEWAY, 4, &saddr);
258
259	if (pData->use_dns_proxy)
260	{
261	uint32_t addr = htonl(ntohl(special_addr.s_addr) \| CTL_DNS);
262	FILL_BOOTP_EXT(q, RFC1533_DNS, 4, &addr);
263	goto skip_dns_servers;
264	}
265
266	if (!TAILQ_EMPTY(&pData->dns_list_head))
267	{
268	de = TAILQ_LAST(&pData->dns_list_head, dns_list_head);
269	q_dns_header = q;
270	FILL_BOOTP_EXT(q, RFC1533_DNS, 4, &de->de_addr.s_addr);
271	}
272
273	TAILQ_FOREACH_REVERSE(de, &pData->dns_list_head, dns_list_head, de_list)
274	{
275	if (TAILQ_LAST(&pData->dns_list_head, dns_list_head) == de)
276	continue; /* first value with head we've ingected before */
277	FILL_BOOTP_APP(q_dns_header, q, RFC1533_DNS, 4, &de->de_addr.s_addr);
278	}
279
280	skip_dns_servers:
281	if (LIST_EMPTY(&pData->dns_domain_list_head))
282	{
283	/* Microsoft dhcp client doen't like domain-less dhcp and trimmed packets*/
284	/* dhcpcd client very sad if no domain name is passed */
285	FILL_BOOTP_EXT(q, RFC1533_DOMAINNAME, 1, " ");
286	}
287	if (pData->fPassDomain)
288	{
289	LIST_FOREACH(dd, &pData->dns_domain_list_head, dd_list)
290	{
291
292	if (dd->dd_pszDomain == NULL)
293	continue;
294	/* never meet valid separator here in RFC1533*/
295	if (added != 0)
296	FILL_BOOTP_EXT(q, RFC1533_DOMAINNAME, 1, ",");
297	else
298	added = 1;
299	val = (int)strlen(dd->dd_pszDomain);
300	FILL_BOOTP_EXT(q, RFC1533_DOMAINNAME, val, dd->dd_pszDomain);
301	}
302	}
303
304	FILL_BOOTP_EXT(q, RFC2132_LEASE_TIME, 4, &lease_time);
305
306	if (*slirp_hostname)
307	{
308	val = (int)strlen(slirp_hostname);
309	FILL_BOOTP_EXT(q, RFC1533_HOSTNAME, val, slirp_hostname);
310	}
311	return q - rbp->bp_vend; /return offset /
312	}
313
314	static int dhcp_send_nack(PNATState pData, struct bootp_t bp, BOOTPClient bc, struct mbuf *m)
315	{
316	struct bootp_t *rbp;
317	uint8_t *q = NULL;
318	rbp = mtod(m, struct bootp_t *);
319
320	dhcp_create_msg(pData, bp, m, DHCPNAK);
321
322	return 7;
323	}
324	static int dhcp_send_ack(PNATState pData, struct bootp_t bp, BOOTPClient bc, struct mbuf *m, int is_from_request)
325	{
326	struct bootp_t *rbp;
327	int off = 0; /* boot_reply will fill general options and add END before sending response*/
328
329	dhcp_create_msg(pData, bp, m, DHCPACK);
330	off = dhcp_do_ack_offer(pData, m, bc, is_from_request);
331	return off;
332	}
333	static int dhcp_send_offer(PNATState pData, struct bootp_t bp, BOOTPClient bc, struct mbuf *m)
334	{
335	struct bootp_t *rbp;
336	int off = 0; /* boot_reply will fill general options and add END before sending response*/
337
338	dhcp_create_msg(pData, bp, m, DHCPOFFER);
339	off = dhcp_do_ack_offer(pData, m, bc, 0);
340	return off;
341	}
342
343	/**
344	* decoding client messages RFC2131 (4.3.6)
345	* ---------------------------------------------------------------------
346	* \| \|INIT-REBOOT \|SELECTING \|RENEWING \|REBINDING \|
347	* ---------------------------------------------------------------------
348	* \|broad/unicast \|broadcast \|broadcast \|unicast \|broadcast \|
349	* \|server-ip \|MUST NOT \|MUST \|MUST NOT \|MUST NOT \|
350	* \|requested-ip \|MUST \|MUST \|MUST NOT \|MUST NOT \|
351	* \|ciaddr \|zero \|zero \|IP address \|IP address\|
352	* ---------------------------------------------------------------------
353	*
354	*/
355	enum DHCP_REQUEST_STATES{INIT_REBOOT, SELECTING, RENEWING, REBINDING, NONE};
356	static int dhcp_decode_request(PNATState pData, struct bootp_t bp, const uint8_t buf, int size, struct mbuf *m)
357	{
358	BOOTPClient *bc;
359	struct in_addr daddr;
360	int off;
361	uint8_t *opt;
362	uint8_t *req_ip;
363	uint8_t *server_ip;
364	enum DHCP_REQUEST_STATES dhcp_stat = NONE;
365	/need to understand which type of request we get /
366	req_ip = dhcp_find_option(&bp->bp_vend[0], RFC2132_REQ_ADDR);
367	server_ip = dhcp_find_option(&bp->bp_vend[0], RFC2132_SRV_ID);
368
369	bc = find_addr(pData, &daddr, bp->bp_hwaddr);
370	if (!bc)
371	{
372	LogRel(("NAT: DHCP no IP address left\n"));
373	Log(("no address left\n"));
374	return -1;
375	}
376	if (server_ip != NULL)
377	{
378	/selecting/
379	dhcp_stat = SELECTING;
380	Assert((bp->bp_ciaddr.s_addr == INADDR_ANY));
381	Assert(((uint32_t )(req_ip + 2) == bc->addr.s_addr)); /the same address as in offer/
382	Assert((bp->bp_xid == bc->xid));
383	}
384	else
385	{
386	if (req_ip != NULL)
387	{
388	/* init-reboot */
389	dhcp_stat = INIT_REBOOT;
390	}
391	else
392	{
393	if (bp->bp_flags & DHCP_FLAGS_B)
394	dhcp_stat = RENEWING;
395	else
396	dhcp_stat = REBINDING; /??rebinding??/
397	}
398	}
399	/?? renewing ??/
400	if(dhcp_stat == RENEWING){
401	Assert(( server_ip == NULL
402	&& req_ip == NULL
403	&& bp->bp_ciaddr.s_addr != INADDR_ANY));
404	if (bc != NULL)
405	{
406	Assert((bc->addr.s_addr == bp->bp_ciaddr.s_addr));
407	/if it already here well just do ack, we aren't aware of dhcp time expiration/
408	}
409	else
410	{
411	if ((bp->bp_ciaddr.s_addr & pData->netmask) != special_addr.s_addr)
412	{
413	off = dhcp_send_nack(pData, bp, bc, m);
414	return off;
415	}
416	bc = alloc_addr(pData);
417	if (bc == NULL)
418	{
419	LogRel(("NAT: can't alloc address. RENEW has been silently ignored\n"));
420	return -1;
421	}
422	Assert((bp->bp_hlen == ETH_ALEN));
423	memcpy(bc->macaddr, bp->bp_hwaddr, bp->bp_hlen);
424	bc->addr.s_addr = bp->bp_ciaddr.s_addr;
425	}
426	}
427	Assert((dhcp_stat != NONE));
428	off = dhcp_send_ack(pData, bp, bc, m, 1);
429	return off;
430	}
431
432	static int dhcp_decode_discover(PNATState pData, struct bootp_t bp, const uint8_t buf, int size, int flag, struct mbuf *m)
433	{
434	BOOTPClient *bc;
435	struct in_addr daddr;
436	int off;
437	/* flag == 1 discover */
438	if (flag == 1)
439	{
440	bc = find_addr(pData, &daddr, bp->bp_hwaddr);
441	if (!bc)
442	{
443	bc = get_new_addr(pData, &daddr);
444	if (!bc)
445	{
446	LogRel(("NAT: DHCP no IP address left\n"));
447	Log(("no address left\n"));
448	return -1;
449	}
450	memcpy(bc->macaddr, bp->bp_hwaddr, 6);
451	}
452	bc->xid = bp->bp_xid;
453	/bc isn't NULL /
454	off = dhcp_send_offer(pData, bp, bc, m);
455	return off;
456	}
457	else
458	{
459	/* flag == 0 inform */
460	bc = find_addr(pData, &daddr, bp->bp_hwaddr);
461	if (bc == NULL)
462	{
463	LogRel(("NAT: DHCP Inform was ignored no boot client was found\n"));
464	return -1;
465	}
466	off = dhcp_send_ack(pData, bp, bc, m, 0);
467	return off;
468	}
469	return -1;
470	}
471
472	static int dhcp_decode_release(PNATState pData, struct bootp_t bp, const uint8_t buf, int size, int flag)
473	{
474	return -1;
475	}
476	/**
477	* fields for discovering t
478	* Field DHCPDISCOVER DHCPREQUEST DHCPDECLINE,
479	* DHCPINFORM DHCPRELEASE
480	* ----- ------------ ----------- -----------
481	* 'op' BOOTREQUEST BOOTREQUEST BOOTREQUEST
482	* 'htype' (From "Assigned Numbers" RFC)
483	* 'hlen' (Hardware address length in octets)
484	* 'hops' 0 0 0
485	* 'xid' selected by client 'xid' from server selected by
486	* DHCPOFFER message client
487	* 'secs' 0 or seconds since 0 or seconds since 0
488	* DHCP process started DHCP process started
489	* 'flags' Set 'BROADCAST' Set 'BROADCAST' 0
490	* flag if client flag if client
491	* requires broadcast requires broadcast
492	* reply reply
493	* 'ciaddr' 0 (DHCPDISCOVER) 0 or client's 0 (DHCPDECLINE)
494	* client's network address client's network
495	* network address (BOUND/RENEW/REBIND) address
496	* (DHCPINFORM) (DHCPRELEASE)
497	* 'yiaddr' 0 0 0
498	* 'siaddr' 0 0 0
499	* 'giaddr' 0 0 0
500	* 'chaddr' client's hardware client's hardware client's hardware
501	* address address address
502	* 'sname' options, if options, if (unused)
503	* indicated in indicated in
504	* 'sname/file' 'sname/file'
505	* option; otherwise option; otherwise
506	* unused unused
507	* 'file' options, if options, if (unused)
508	* indicated in indicated in
509	* 'sname/file' 'sname/file'
510	* option; otherwise option; otherwise
511	* unused unused
512	* 'options' options options (unused)
513	* Requested IP address MAY MUST (in MUST
514	* (DISCOVER) SELECTING or (DHCPDECLINE),
515	* MUST NOT INIT-REBOOT) MUST NOT
516	* (INFORM) MUST NOT (in (DHCPRELEASE)
517	* BOUND or
518	* RENEWING)
519	* IP address lease time MAY MAY MUST NOT
520	* (DISCOVER)
521	* MUST NOT
522	* (INFORM)
523	* Use 'file'/'sname' fields MAY MAY MAY
524	* DHCP message type DHCPDISCOVER/ DHCPREQUEST DHCPDECLINE/
525	* DHCPINFORM DHCPRELEASE
526	* Client identifier MAY MAY MAY
527	* Vendor class identifier MAY MAY MUST NOT
528	* Server identifier MUST NOT MUST (after MUST
529	* SELECTING)
530	* MUST NOT (after
531	* INIT-REBOOT,
532	* BOUND, RENEWING
533	* or REBINDING)
534	* Parameter request list MAY MAY MUST NOT
535	* Maximum message size MAY MAY MUST NOT
536	* Message SHOULD NOT SHOULD NOT SHOULD
537	* Site-specific MAY MAY MUST NOT
538	* All others MAY MAY MUST NOT
539	*
540	*/
541	static void dhcp_decode(PNATState pData, struct bootp_t bp, const uint8_t buf, int size)
542	{
543	const uint8_t p, p_end;
544	int rc;
545	int pmsg_type;
546	struct in_addr req_ip;
547	int flag = 0;
548	int len, tag;
549	struct mbuf *m = NULL;
550
551	pmsg_type = 0;
552
553	p = buf;
554	p_end = buf + size;
555	if (size < 5)
556	return;
557	if (memcmp(p, rfc1533_cookie, 4) != 0)
558	return;
559	p = dhcp_find_option(bp->bp_vend, RFC2132_MSG_TYPE);
560	Assert(p);
561	if (p == NULL)
562	return;
563	if ((m = m_get(pData)) == NULL)
564	{
565	LogRel(("NAT: can't alocate memory for response!\n"));
566	return;
567	}
568	switch(*(p+2))
569	{
570	case DHCPDISCOVER:
571	flag = 1;
572	/**/
573	case DHCPINFORM:
574	rc = dhcp_decode_discover(pData, bp, buf, size, flag, m);
575	Assert(rc > 0);
576	goto reply;
577	break;
578	case DHCPREQUEST:
579	rc = dhcp_decode_request(pData, bp, buf, size, m);
580	Assert(rc > 0);
581	goto reply;
582	break;
583	case DHCPRELEASE:
584	flag = 1;
585	#if 0
586	case DHCPDECLINE:
587	#endif
588	rc = dhcp_decode_release(pData, bp, buf, size, flag);
589	Assert(rc > 0);
590	goto reply;
591	break;
592	default:
593	AssertMsgFailed(("unsupported DHCP message type"));
594	}
595	return;
596	reply:
597	Assert(m);
598	if (rc < 0)
599	{
600	/silently ignore/
601	m_free(pData, m);
602	return;
603	}
604	bootp_reply(pData, m, rc, bp->bp_flags);
605	return;
606	}
607
608	static void bootp_reply(PNATState pData, struct mbuf *m, int off, uint16_t flags)
609	{
610	#if 0
611	BOOTPClient *bc;
612	struct mbuf m; / XXX: @todo vasily - it'd be better to reuse this mbuf here */
613	struct bootp_t bp = mtod(m0, struct bootp_t );
614	struct bootp_t *rbp;
615	struct sockaddr_in saddr, daddr;
616	int dhcp_msg_type, val;
617	uint8_t *q;
618	struct in_addr requested_ip; /* the requested IP in DHCPREQUEST */
619	int send_nak = 0;
620
621	/* extract exact DHCP msg type */
622	requested_ip.s_addr = 0xffffffff;
623	dhcp_decode(bp, bp->bp_vend, DHCP_OPT_LEN, &dhcp_msg_type, &requested_ip);
624	Log(("bootp packet op=%d msgtype=%d\n", bp->bp_op, dhcp_msg_type));
625
626	if (dhcp_msg_type == 0)
627	dhcp_msg_type = DHCPREQUEST; /* Force reply for old BOOTP clients */
628
629	if (dhcp_msg_type == DHCPRELEASE)
630	{
631	int rc;
632	rc = release_addr(pData, &bp->bp_ciaddr);
633	LogRel(("NAT: %s %R[IP4]\n",
634	rc ? "DHCP released IP address" : "Ignored DHCP release for IP address",
635	&bp->bp_ciaddr));
636	/* This message is not to be answered in any way. */
637	return;
638	}
639	if ( dhcp_msg_type != DHCPDISCOVER
640	&& dhcp_msg_type != DHCPREQUEST)
641	return;
642
643
644	if (dhcp_msg_type == DHCPDISCOVER)
645	{
646	/* Do not allocate a new lease for clients that forgot that they had a lease. */
647	}
648	else if (dhcp_msg_type == DHCPREQUEST)
649	{
650	*q++ = RFC2132_MSG_TYPE;
651	*q++ = 1;
652	if (requested_ip.s_addr != daddr.sin_addr.s_addr)
653	{
654	/* network changed */
655	*q++ = DHCPNAK;
656	send_nak = 1;
657	}
658	else
659	*q++ = DHCPACK;
660	}
661
662	if (send_nak)
663	LogRel(("NAT: Client requested IP address %R[IP4] -- sending NAK\n",
664	&requested_ip));
665	else
666	LogRel(("NAT: DHCP offered IP address %R[IP4]\n",
667	&daddr.sin_addr));
668	if ( dhcp_msg_type == DHCPDISCOVER
669	\|\| dhcp_msg_type == DHCPREQUEST)
670	{
671	FILL_BOOTP_EXT(q, RFC2132_SRV_ID, 4, &saddr.sin_addr);
672	}
673
674	if (!send_nak &&
675	( dhcp_msg_type == DHCPDISCOVER
676	\|\| dhcp_msg_type == DHCPREQUEST))
677	#endif
678	struct sockaddr_in saddr, daddr;
679	struct bootp_t *rbp = NULL;
680	uint8_t *q = NULL;
681	int nack;
682	rbp = mtod(m, struct bootp_t *);
683	Assert((m));
684	Assert((rbp));
685	q = rbp->bp_vend;
686	nack = (q[6] == DHCPNAK);
687	q += off;
688
689	#ifndef VBOX_WITH_NAT_SERVICE
690	saddr.sin_addr.s_addr = htonl(ntohl(special_addr.s_addr) \| CTL_ALIAS);
691	#else
692	saddr.sin_addr.s_addr = special_addr.s_addr;
693	#endif
694
695	FILL_BOOTP_EXT(q, RFC2132_SRV_ID, 4, &saddr.sin_addr);
696
697
698	q++ = RFC1533_END; /end of message */
699
700
701	m->m_len = sizeof(struct bootp_t)
702	- sizeof(struct ip)
703	- sizeof(struct udphdr);
704	m->m_data += sizeof(struct udphdr)
705	+ sizeof(struct ip);
706	if ((flags & DHCP_FLAGS_B) \|\| nack != 0)
707	daddr.sin_addr.s_addr = INADDR_BROADCAST;
708	else
709	daddr.sin_addr.s_addr = rbp->bp_yiaddr.s_addr; /unicast requested by client/
710	saddr.sin_port = htons(BOOTP_SERVER);
711	daddr.sin_port = htons(BOOTP_CLIENT);
712	udp_output2(pData, NULL, m, &saddr, &daddr, IPTOS_LOWDELAY);
713	}
714
715	void bootp_input(PNATState pData, struct mbuf *m)
716	{
717	struct bootp_t bp = mtod(m, struct bootp_t );
718
719	if (bp->bp_op == BOOTP_REQUEST)
720	{
721	dhcp_decode(pData, bp, bp->bp_vend, DHCP_OPT_LEN);
722	}
723	}

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source: vbox/trunk/src/VBox/Devices/Network/slirp/bootp.c@ 22103

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