bootp.c@ 18902

Last change on this file since 18902 was 18902, checked in by vboxsync, 16 years ago
NAT: removed VBOX_WITH_SIMPLIFIED_SLIRP_SYNC as the poller API was removed some days ago
Property svn:eol-style set to `native`
File size: 10.5 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	return bc;
44	}
45	}
46	return NULL;
47	}
48
49	static int release_addr(PNATState pData, struct in_addr *paddr)
50	{
51	unsigned i;
52
53	i = ntohl(paddr->s_addr) - START_ADDR - ntohl(special_addr.s_addr);
54	if (i >= NB_ADDR)
55	return 0;
56
57	memset(bootp_clients[i].macaddr, '\0', 6);
58	bootp_clients[i].allocated = 0;
59	return 1;
60	}
61
62	static BOOTPClient find_addr(PNATState pData, struct in_addr paddr, const uint8_t *macaddr)
63	{
64	int i;
65
66	for(i = 0; i < NB_ADDR; i++)
67	{
68	if (!memcmp(macaddr, bootp_clients[i].macaddr, 6))
69	{
70	BOOTPClient *bc;
71
72	bc = &bootp_clients[i];
73	bc->allocated = 1;
74	paddr->s_addr = htonl(ntohl(special_addr.s_addr) \| (i + START_ADDR));
75	return bc;
76	}
77	}
78	return NULL;
79	}
80
81	static void dhcp_decode(const uint8_t *buf, int size,
82	int pmsg_type, struct in_addr req_ip)
83	{
84	const uint8_t p, p_end;
85	int len, tag;
86
87	*pmsg_type = 0;
88
89	p = buf;
90	p_end = buf + size;
91	if (size < 5)
92	return;
93	if (memcmp(p, rfc1533_cookie, 4) != 0)
94	return;
95	p += 4;
96	while (p < p_end)
97	{
98	tag = p[0];
99	if (tag == RFC1533_PAD)
100	p++;
101	else if (tag == RFC1533_END)
102	break;
103	else
104	{
105	p++;
106	if (p >= p_end)
107	break;
108	len = *p++;
109	Log(("dhcp: tag=0x%02x len=%d\n", tag, len));
110
111	switch(tag)
112	{
113	case RFC2132_REQ_ADDR:
114	if (len >= 4)
115	req_ip = (struct in_addr*)p;
116	break;
117	case RFC2132_MSG_TYPE:
118	if (len >= 1)
119	*pmsg_type = p[0];
120	break;
121	default:
122	break;
123	}
124	p += len;
125	}
126	}
127	}
128
129	static void bootp_reply(PNATState pData, struct bootp_t *bp)
130	{
131	BOOTPClient *bc;
132	struct mbuf *m;
133	struct bootp_t *rbp;
134	struct sockaddr_in saddr, daddr;
135	#ifndef VBOX_WITH_MULTI_DNS
136	struct in_addr dns_addr_dhcp;
137	#endif
138	int dhcp_msg_type, val;
139	uint8_t *q;
140	struct in_addr requested_ip; /* the requested IP in DHCPREQUEST */
141	int send_nak = 0;
142
143	#define FILL_BOOTP_EXT(q, tag, len, pvalue) \
144	do { \
145	struct bootp_ext be = (struct bootp_ext )(q); \
146	be->bpe_tag = (tag); \
147	be->bpe_len = (len); \
148	memcpy(&be[1], (pvalue), (len)); \
149	(q) = (uint8_t *)(&be[1]) + (len); \
150	}while(0)
151
152	/* extract exact DHCP msg type */
153	requested_ip.s_addr = 0xffffffff;
154	dhcp_decode(bp->bp_vend, DHCP_OPT_LEN, &dhcp_msg_type, &requested_ip);
155	Log(("bootp packet op=%d msgtype=%d\n", bp->bp_op, dhcp_msg_type));
156
157	if (dhcp_msg_type == 0)
158	dhcp_msg_type = DHCPREQUEST; /* Force reply for old BOOTP clients */
159
160	if (dhcp_msg_type == DHCPRELEASE)
161	{
162	int rc;
163	rc = release_addr(pData, &bp->bp_ciaddr);
164	LogRel(("NAT: %s %R[IP4]\n",
165	rc ? "DHCP released IP address" : "Ignored DHCP release for IP address",
166	&bp->bp_ciaddr));
167	/* This message is not to be answered in any way. */
168	return;
169	}
170	if ( dhcp_msg_type != DHCPDISCOVER
171	&& dhcp_msg_type != DHCPREQUEST)
172	return;
173
174	/* XXX: this is a hack to get the client mac address */
175	memcpy(client_ethaddr, bp->bp_hwaddr, 6);
176
177	if ((m = m_get(pData)) == NULL)
178	return;
179	m->m_data += if_maxlinkhdr; /reserve ether header /
180	rbp = mtod(m, struct bootp_t *);
181	memset(rbp, 0, sizeof(struct bootp_t));
182
183	if (dhcp_msg_type == DHCPDISCOVER)
184	{
185	/* Do not allocate a new lease for clients that forgot that they had a lease. */
186	bc = find_addr(pData, &daddr.sin_addr, bp->bp_hwaddr);
187	if (!bc)
188	{
189	new_addr:
190	bc = get_new_addr(pData, &daddr.sin_addr);
191	if (!bc)
192	{
193	LogRel(("NAT: DHCP no IP address left\n"));
194	Log(("no address left\n"));
195	return;
196	}
197	memcpy(bc->macaddr, client_ethaddr, 6);
198	}
199	}
200	else
201	{
202	bc = find_addr(pData, &daddr.sin_addr, bp->bp_hwaddr);
203	if (!bc)
204	{
205	/* if never assigned, behaves as if it was already
206	assigned (windows fix because it remembers its address) */
207	goto new_addr;
208	}
209	}
210
211	if ( tftp_prefix
212	&& RTDirExists(tftp_prefix)
213	&& bootp_filename)
214	RTStrPrintf((char*)rbp->bp_file, sizeof(rbp->bp_file), "%s", bootp_filename);
215
216	/* Address/port of the DHCP server. */
217	saddr.sin_addr.s_addr = htonl(ntohl(special_addr.s_addr) \| CTL_ALIAS);
218	saddr.sin_port = htons(BOOTP_SERVER);
219
220	daddr.sin_port = htons(BOOTP_CLIENT);
221
222	rbp->bp_op = BOOTP_REPLY;
223	rbp->bp_xid = bp->bp_xid;
224	rbp->bp_htype = 1;
225	rbp->bp_hlen = 6;
226	memcpy(rbp->bp_hwaddr, bp->bp_hwaddr, 6);
227
228	rbp->bp_yiaddr = daddr.sin_addr; /* Client IP address */
229	rbp->bp_siaddr = pData->tftp_server; /* Next Server IP address, i.e. TFTP */
230
231	q = rbp->bp_vend;
232	memcpy(q, rfc1533_cookie, 4);
233	q += 4;
234
235	if (dhcp_msg_type == DHCPDISCOVER)
236	{
237	*q++ = RFC2132_MSG_TYPE;
238	*q++ = 1;
239	*q++ = DHCPOFFER;
240	}
241	else if (dhcp_msg_type == DHCPREQUEST)
242	{
243	*q++ = RFC2132_MSG_TYPE;
244	*q++ = 1;
245	if ( requested_ip.s_addr != 0xffffffff
246	&& requested_ip.s_addr != daddr.sin_addr.s_addr)
247	{
248	/* network changed */
249	*q++ = DHCPNAK;
250	send_nak = 1;
251	}
252	else
253	*q++ = DHCPACK;
254	}
255
256	if (send_nak)
257	LogRel(("NAT: Client requested IP address %R[IP4] -- sending NAK\n",
258	&requested_ip));
259	else
260	LogRel(("NAT: DHCP offered IP address %R[IP4]\n",
261	&daddr.sin_addr));
262	if ( dhcp_msg_type == DHCPDISCOVER
263	\|\| dhcp_msg_type == DHCPREQUEST)
264	{
265	FILL_BOOTP_EXT(q, RFC2132_SRV_ID, 4, &saddr.sin_addr);
266	}
267
268	if (!send_nak &&
269	( dhcp_msg_type == DHCPDISCOVER
270	\|\| dhcp_msg_type == DHCPREQUEST))
271	{
272	#ifdef VBOX_WITH_MULTI_DNS
273	struct dns_entry *de = NULL;
274	struct dns_domain_entry *dd = NULL;
275	int added = 0;
276	#endif
277	uint32_t lease_time = htonl(LEASE_TIME);
278	uint32_t netmask = htonl(pData->netmask);
279
280	FILL_BOOTP_EXT(q, RFC1533_NETMASK, 4, &netmask);
281	FILL_BOOTP_EXT(q, RFC1533_GATEWAY, 4, &saddr.sin_addr);
282
283	#ifndef VBOX_WITH_MULTI_DNS
284	dns_addr_dhcp.s_addr = htonl(ntohl(special_addr.s_addr) \| CTL_DNS);
285	FILL_BOOTP_EXT(q, RFC1533_DNS, 4, &dns_addr_dhcp.s_addr);
286	#else
287	# ifdef VBOX_WITH_SLIRP_DNS_PROXY
288	if (pData->use_dns_proxy)
289	{
290	uint32_t addr = htonl(ntohl(special_addr.s_addr) \| CTL_DNS);
291	FILL_BOOTP_EXT(q, RFC1533_DNS, 4, &addr);
292	}
293	else
294	# endif
295	LIST_FOREACH(de, &pData->dns_list_head, de_list)
296	{
297	FILL_BOOTP_EXT(q, RFC1533_DNS, 4, &de->de_addr.s_addr);
298	}
299	if (LIST_EMPTY(&pData->dns_domain_list_head))
300	{
301	/* Microsoft dhcp client doen't like domain-less dhcp and trimmed packets*/
302	/* dhcpcd client very sad if no domain name is passed */
303	FILL_BOOTP_EXT(q, RFC1533_DOMAINNAME, 1, " ");
304	}
305	LIST_FOREACH(dd, &pData->dns_domain_list_head, dd_list)
306	{
307
308	if (dd->dd_pszDomain == NULL)
309	continue;
310	if (added != 0)
311	FILL_BOOTP_EXT(q, RFC1533_DOMAINNAME, 1, ","); /* never meet valid separator here in RFC1533*/
312	else
313	added = 1;
314	val = (int)strlen(dd->dd_pszDomain);
315	FILL_BOOTP_EXT(q, RFC1533_DOMAINNAME, val, dd->dd_pszDomain);
316	}
317	#endif
318
319	FILL_BOOTP_EXT(q, RFC2132_LEASE_TIME, 4, &lease_time);
320
321	if (*slirp_hostname)
322	{
323	val = (int)strlen(slirp_hostname);
324	FILL_BOOTP_EXT(q, RFC1533_HOSTNAME, val, slirp_hostname);
325	}
326
327	#ifndef VBOX_WITH_MULTI_DNS
328	if (pData->pszDomain && pData->fPassDomain)
329	{
330	val = (int)strlen(pData->pszDomain);
331	FILL_BOOTP_EXT(q, RFC1533_DOMAINNAME, val, pData->pszDomain);
332	}
333	#endif
334	}
335	*q++ = RFC1533_END;
336
337	m->m_len = sizeof(struct bootp_t)
338	- sizeof(struct ip)
339	- sizeof(struct udphdr);
340	m->m_data += sizeof(struct udphdr)
341	+ sizeof(struct ip);
342	/* Reply to the broadcast address, as some clients perform paranoid checks. */
343	daddr.sin_addr.s_addr = INADDR_BROADCAST;
344	udp_output2(pData, NULL, m, &saddr, &daddr, IPTOS_LOWDELAY);
345	}
346
347	void bootp_input(PNATState pData, struct mbuf *m)
348	{
349	struct bootp_t bp = mtod(m, struct bootp_t );
350
351	if (bp->bp_op == BOOTP_REQUEST)
352	bootp_reply(pData, bp);
353	}

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source: vbox/trunk/src/VBox/Devices/Network/slirp/bootp.c@ 18902

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