bootp.c@ 19846

Last change on this file since 19846 was 19839, checked in by vboxsync, 16 years ago
NAT: Slirp don't use ether address of guest anymore instead it calculates ethernet address of destination with lookup operation. Currently it's very simple looks over send addresses via dhcp or assume destination in outer network and gets Slirp's ethernet address.
Property svn:eol-style set to `native`
File size: 12.4 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
30	static BOOTPClient get_new_addr(PNATState pData, struct in_addr paddr)
31	{
32	int i;
33
34	for(i = 0; i < NB_ADDR; i++)
35	{
36	if (!bootp_clients[i].allocated)
37	{
38	BOOTPClient *bc;
39
40	bc = &bootp_clients[i];
41	bc->allocated = 1;
42	paddr->s_addr = htonl(ntohl(special_addr.s_addr) \| (i + START_ADDR));
43	#ifdef VBOX_WITHOUT_SLIRP_CLIENT_ETHER
44	bc->addr.s_addr = paddr->s_addr;
45	#endif
46	return bc;
47	}
48	}
49	return NULL;
50	}
51
52	static int release_addr(PNATState pData, struct in_addr *paddr)
53	{
54	unsigned i;
55
56	i = ntohl(paddr->s_addr) - START_ADDR - ntohl(special_addr.s_addr);
57	if (i >= NB_ADDR)
58	return 0;
59
60	memset(bootp_clients[i].macaddr, '\0', 6);
61	bootp_clients[i].allocated = 0;
62	return 1;
63	}
64
65	static BOOTPClient find_addr(PNATState pData, struct in_addr paddr, const uint8_t *macaddr)
66	{
67	int i;
68
69	for(i = 0; i < NB_ADDR; i++)
70	{
71	if (!memcmp(macaddr, bootp_clients[i].macaddr, 6))
72	{
73	BOOTPClient *bc;
74
75	bc = &bootp_clients[i];
76	bc->allocated = 1;
77	paddr->s_addr = htonl(ntohl(special_addr.s_addr) \| (i + START_ADDR));
78	return bc;
79	}
80	}
81	return NULL;
82	}
83
84	static void dhcp_decode(const uint8_t *buf, int size,
85	int pmsg_type, struct in_addr req_ip)
86	{
87	const uint8_t p, p_end;
88	int len, tag;
89
90	*pmsg_type = 0;
91
92	p = buf;
93	p_end = buf + size;
94	if (size < 5)
95	return;
96	if (memcmp(p, rfc1533_cookie, 4) != 0)
97	return;
98	p += 4;
99	while (p < p_end)
100	{
101	tag = p[0];
102	if (tag == RFC1533_PAD)
103	p++;
104	else if (tag == RFC1533_END)
105	break;
106	else
107	{
108	p++;
109	if (p >= p_end)
110	break;
111	len = *p++;
112	Log(("dhcp: tag=0x%02x len=%d\n", tag, len));
113
114	switch(tag)
115	{
116	case RFC2132_REQ_ADDR:
117	if (len >= 4)
118	req_ip = (struct in_addr*)p;
119	break;
120	case RFC2132_MSG_TYPE:
121	if (len >= 1)
122	*pmsg_type = p[0];
123	break;
124	default:
125	break;
126	}
127	p += len;
128	}
129	}
130	}
131
132	#ifndef VBOX_WITHOUT_SLIRP_CLIENT_ETHER
133	static void bootp_reply(PNATState pData, struct bootp_t *bp)
134	#else
135	static void bootp_reply(PNATState pData, struct mbuf *m0)
136	#endif
137	{
138	BOOTPClient *bc;
139	struct mbuf m; / XXX: @todo vasily - it'd be better to reuse this mbuf here */
140	#ifdef VBOX_WITHOUT_SLIRP_CLIENT_ETHER
141	struct bootp_t bp = mtod(m0, struct bootp_t );
142	struct ethhdr *eh;
143	#endif
144	struct bootp_t *rbp;
145	struct sockaddr_in saddr, daddr;
146	#ifndef VBOX_WITH_MULTI_DNS
147	struct in_addr dns_addr_dhcp;
148	#endif
149	int dhcp_msg_type, val;
150	uint8_t *q;
151	struct in_addr requested_ip; /* the requested IP in DHCPREQUEST */
152	int send_nak = 0;
153
154	#define FILL_BOOTP_EXT(q, tag, len, pvalue) \
155	do { \
156	struct bootp_ext be = (struct bootp_ext )(q); \
157	be->bpe_tag = (tag); \
158	be->bpe_len = (len); \
159	memcpy(&be[1], (pvalue), (len)); \
160	(q) = (uint8_t *)(&be[1]) + (len); \
161	}while(0)
162	/* appending another value to tag, calculates len of whole block*/
163	#define FILL_BOOTP_APP(head, q, tag, len, pvalue) \
164	do { \
165	struct bootp_ext be = (struct bootp_ext )(head); \
166	memcpy(q, (pvalue), (len)); \
167	(q) += (len); \
168	Assert(be->bpe_tag == (tag)); \
169	be->bpe_len += (len); \
170	}while(0)
171
172	/* extract exact DHCP msg type */
173	requested_ip.s_addr = 0xffffffff;
174	dhcp_decode(bp->bp_vend, DHCP_OPT_LEN, &dhcp_msg_type, &requested_ip);
175	Log(("bootp packet op=%d msgtype=%d\n", bp->bp_op, dhcp_msg_type));
176
177	if (dhcp_msg_type == 0)
178	dhcp_msg_type = DHCPREQUEST; /* Force reply for old BOOTP clients */
179
180	if (dhcp_msg_type == DHCPRELEASE)
181	{
182	int rc;
183	rc = release_addr(pData, &bp->bp_ciaddr);
184	LogRel(("NAT: %s %R[IP4]\n",
185	rc ? "DHCP released IP address" : "Ignored DHCP release for IP address",
186	&bp->bp_ciaddr));
187	/* This message is not to be answered in any way. */
188	return;
189	}
190	if ( dhcp_msg_type != DHCPDISCOVER
191	&& dhcp_msg_type != DHCPREQUEST)
192	return;
193
194	#ifndef VBOX_WITHOUT_SLIRP_CLIENT_ETHER
195	/* XXX: this is a hack to get the client mac address */
196	memcpy(client_ethaddr, bp->bp_hwaddr, 6);
197	#endif
198
199	if ((m = m_get(pData)) == NULL)
200	return;
201	#ifdef VBOX_WITHOUT_SLIRP_CLIENT_ETHER
202	eh = mtod(m, struct ethhdr *);
203	memcpy(eh->h_source, bp->bp_hwaddr, ETH_ALEN); /* XXX: if_encap just swap source with dest*/
204	#endif
205	m->m_data += if_maxlinkhdr; /reserve ether header /
206	rbp = mtod(m, struct bootp_t *);
207	memset(rbp, 0, sizeof(struct bootp_t));
208
209	if (dhcp_msg_type == DHCPDISCOVER)
210	{
211	/* Do not allocate a new lease for clients that forgot that they had a lease. */
212	bc = find_addr(pData, &daddr.sin_addr, bp->bp_hwaddr);
213	if (!bc)
214	{
215	new_addr:
216	bc = get_new_addr(pData, &daddr.sin_addr);
217	if (!bc)
218	{
219	LogRel(("NAT: DHCP no IP address left\n"));
220	Log(("no address left\n"));
221	return;
222	}
223	#ifdef VBOX_WITHOUT_SLIRP_CLIENT_ETHER
224	memcpy(bc->macaddr, bp->bp_hwaddr, 6);
225	#else
226	memcpy(bc->macaddr, client_ethaddr, 6);
227	#endif
228	}
229	}
230	else
231	{
232	bc = find_addr(pData, &daddr.sin_addr, bp->bp_hwaddr);
233	if (!bc)
234	{
235	/* if never assigned, behaves as if it was already
236	assigned (windows fix because it remembers its address) */
237	goto new_addr;
238	}
239	}
240
241	if ( tftp_prefix
242	&& RTDirExists(tftp_prefix)
243	&& bootp_filename)
244	RTStrPrintf((char*)rbp->bp_file, sizeof(rbp->bp_file), "%s", bootp_filename);
245
246	/* Address/port of the DHCP server. */
247	#ifndef VBOX_WITHOUT_SLIRP_CLIENT_ETHER
248	saddr.sin_addr.s_addr = htonl(ntohl(special_addr.s_addr) \| CTL_ALIAS);
249	#else
250	saddr.sin_addr.s_addr = special_addr.s_addr;
251	#endif
252
253	saddr.sin_port = htons(BOOTP_SERVER);
254
255	daddr.sin_port = htons(BOOTP_CLIENT);
256
257	rbp->bp_op = BOOTP_REPLY;
258	rbp->bp_xid = bp->bp_xid;
259	rbp->bp_htype = 1;
260	rbp->bp_hlen = 6;
261	memcpy(rbp->bp_hwaddr, bp->bp_hwaddr, 6);
262
263	rbp->bp_yiaddr = daddr.sin_addr; /* Client IP address */
264	rbp->bp_siaddr = pData->tftp_server; /* Next Server IP address, i.e. TFTP */
265
266	q = rbp->bp_vend;
267	memcpy(q, rfc1533_cookie, 4);
268	q += 4;
269
270	if (dhcp_msg_type == DHCPDISCOVER)
271	{
272	*q++ = RFC2132_MSG_TYPE;
273	*q++ = 1;
274	*q++ = DHCPOFFER;
275	}
276	else if (dhcp_msg_type == DHCPREQUEST)
277	{
278	*q++ = RFC2132_MSG_TYPE;
279	*q++ = 1;
280	if ( requested_ip.s_addr != 0xffffffff
281	&& requested_ip.s_addr != daddr.sin_addr.s_addr)
282	{
283	/* network changed */
284	*q++ = DHCPNAK;
285	send_nak = 1;
286	}
287	else
288	*q++ = DHCPACK;
289	}
290
291	if (send_nak)
292	LogRel(("NAT: Client requested IP address %R[IP4] -- sending NAK\n",
293	&requested_ip));
294	else
295	LogRel(("NAT: DHCP offered IP address %R[IP4]\n",
296	&daddr.sin_addr));
297	if ( dhcp_msg_type == DHCPDISCOVER
298	\|\| dhcp_msg_type == DHCPREQUEST)
299	{
300	FILL_BOOTP_EXT(q, RFC2132_SRV_ID, 4, &saddr.sin_addr);
301	}
302
303	if (!send_nak &&
304	( dhcp_msg_type == DHCPDISCOVER
305	\|\| dhcp_msg_type == DHCPREQUEST))
306	{
307	#ifdef VBOX_WITH_MULTI_DNS
308	struct dns_entry *de = NULL;
309	struct dns_domain_entry *dd = NULL;
310	int added = 0;
311	uint8_t *q_dns_header = NULL;
312	#endif
313	uint32_t lease_time = htonl(LEASE_TIME);
314	uint32_t netmask = htonl(pData->netmask);
315
316	FILL_BOOTP_EXT(q, RFC1533_NETMASK, 4, &netmask);
317	FILL_BOOTP_EXT(q, RFC1533_GATEWAY, 4, &saddr.sin_addr);
318
319	#ifndef VBOX_WITH_MULTI_DNS
320	dns_addr_dhcp.s_addr = htonl(ntohl(special_addr.s_addr) \| CTL_DNS);
321	FILL_BOOTP_EXT(q, RFC1533_DNS, 4, &dns_addr_dhcp.s_addr);
322	#else
323	# ifdef VBOX_WITH_SLIRP_DNS_PROXY
324	if (pData->use_dns_proxy)
325	{
326	uint32_t addr = htonl(ntohl(special_addr.s_addr) \| CTL_DNS);
327	FILL_BOOTP_EXT(q, RFC1533_DNS, 4, &addr);
328	goto skip_dns_servers;
329	}
330	# endif
331
332
333	if (!LIST_EMPTY(&pData->dns_list_head))
334	{
335	de = LIST_FIRST(&pData->dns_list_head);
336	q_dns_header = q;
337	FILL_BOOTP_EXT(q, RFC1533_DNS, 4, &de->de_addr.s_addr);
338	}
339
340	LIST_FOREACH(de, &pData->dns_list_head, de_list)
341	{
342	if (LIST_FIRST(&pData->dns_list_head) == de)
343	continue; /* first value with head we've ingected before */
344	FILL_BOOTP_APP(q_dns_header, q, RFC1533_DNS, 4, &de->de_addr.s_addr);
345	}
346
347	#ifdef VBOX_WITH_SLIRP_DNS_PROXY
348	skip_dns_servers:
349	#endif
350	if (LIST_EMPTY(&pData->dns_domain_list_head))
351	{
352	/* Microsoft dhcp client doen't like domain-less dhcp and trimmed packets*/
353	/* dhcpcd client very sad if no domain name is passed */
354	FILL_BOOTP_EXT(q, RFC1533_DOMAINNAME, 1, " ");
355	}
356	LIST_FOREACH(dd, &pData->dns_domain_list_head, dd_list)
357	{
358
359	if (dd->dd_pszDomain == NULL)
360	continue;
361	if (added != 0)
362	FILL_BOOTP_EXT(q, RFC1533_DOMAINNAME, 1, ","); /* never meet valid separator here in RFC1533*/
363	else
364	added = 1;
365	val = (int)strlen(dd->dd_pszDomain);
366	FILL_BOOTP_EXT(q, RFC1533_DOMAINNAME, val, dd->dd_pszDomain);
367	}
368	#endif
369
370	FILL_BOOTP_EXT(q, RFC2132_LEASE_TIME, 4, &lease_time);
371
372	if (*slirp_hostname)
373	{
374	val = (int)strlen(slirp_hostname);
375	FILL_BOOTP_EXT(q, RFC1533_HOSTNAME, val, slirp_hostname);
376	}
377
378	#ifndef VBOX_WITH_MULTI_DNS
379	if (pData->pszDomain && pData->fPassDomain)
380	{
381	val = (int)strlen(pData->pszDomain);
382	FILL_BOOTP_EXT(q, RFC1533_DOMAINNAME, val, pData->pszDomain);
383	}
384	#endif
385	}
386	*q++ = RFC1533_END;
387
388	m->m_len = sizeof(struct bootp_t)
389	- sizeof(struct ip)
390	- sizeof(struct udphdr);
391	m->m_data += sizeof(struct udphdr)
392	+ sizeof(struct ip);
393	/* Reply to the broadcast address, as some clients perform paranoid checks. */
394	daddr.sin_addr.s_addr = INADDR_BROADCAST;
395	udp_output2(pData, NULL, m, &saddr, &daddr, IPTOS_LOWDELAY);
396	}
397
398	void bootp_input(PNATState pData, struct mbuf *m)
399	{
400	struct bootp_t bp = mtod(m, struct bootp_t );
401
402	if (bp->bp_op == BOOTP_REQUEST)
403	#ifndef VBOX_WITHOUT_SLIRP_CLIENT_ETHER
404	bootp_reply(pData, bp);
405	#else
406	bootp_reply(pData, m);
407	#endif
408	}

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source: vbox/trunk/src/VBox/Devices/Network/slirp/bootp.c@ 19846

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