DhcpMessage.cpp@ 79761

最後變更在這個檔案從79761是 79568,由 vboxsync 提交於 6 年前
Dhcpd: Went over the DhcpMessage a little as well as revisiting the lease reading code in the database. Logging is LogRel() or similar, no cout, RTPrintf or similar. The debug & release loggers can both output to stderr/out/whatever as needed. bugref:9288
屬性 svn:eol-style 設為 `native` 屬性 svn:keywords 設為 `Author Date Id Revision`
檔案大小: 12.3 KB

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1	/* $Id: DhcpMessage.cpp 79568 2019-07-06 23:42:51Z vboxsync $ */
2	/** @file
3	* DHCP Message and its de/serialization.
4	*/
5
6	/*
7	* Copyright (C) 2017-2019 Oracle Corporation
8	*
9	* This file is part of VirtualBox Open Source Edition (OSE), as
10	* available from http://www.alldomusa.eu.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	/*********************************************************************************************************************************
20	* Header Files *
21	*********************************************************************************************************************************/
22	#include "DhcpdInternal.h"
23	#include "DhcpMessage.h"
24	#include "DhcpOptions.h"
25
26	#include <iprt/string.h>
27
28
29
30	DhcpMessage::DhcpMessage()
31	: m_xid(0)
32	, m_flags(0)
33	, m_ciaddr()
34	, m_yiaddr()
35	, m_siaddr()
36	, m_giaddr()
37	#if 0 /* not currently unused */
38	, m_sname()
39	, m_file()
40	#endif
41	, m_optMessageType()
42	{
43	}
44
45
46	/*********************************************************************************************************************************
47	* DhcpClientMessage Implementation *
48	*********************************************************************************************************************************/
49
50	/* static */
51	DhcpClientMessage DhcpClientMessage::parse(bool broadcasted, const void buf, size_t buflen)
52	{
53	/*
54	* Validate the request.
55	*/
56	if (buflen < RT_OFFSETOF(RTNETBOOTP, bp_vend.Dhcp.dhcp_opts))
57	DHCP_LOG2_RET_NULL(("DhcpClientMessage::parse: %zu bytes datagram is too short\n", buflen));
58
59	PCRTNETBOOTP bp = (PCRTNETBOOTP)buf;
60
61	if (bp->bp_op != RTNETBOOTP_OP_REQUEST)
62	DHCP_LOG2_RET_NULL(("DhcpClientMessage::parse: bad opcode: %d\n", bp->bp_op));
63
64	if (bp->bp_htype != RTNET_ARP_ETHER)
65	DHCP_LOG2_RET_NULL(("DhcpClientMessage::parse: unsupported htype %d\n", bp->bp_htype));
66
67	if (bp->bp_hlen != sizeof(RTMAC))
68	DHCP_LOG2_RET_NULL(("DhcpClientMessage::parse: unexpected hlen %d\n", bp->bp_hlen));
69
70	if ( (bp->bp_chaddr.Mac.au8[0] & 0x01) != 0
71	&& (bp->bp_flags & RTNET_DHCP_FLAG_BROADCAST) == 0)
72	LogRel2(("DhcpClientMessage::parse: multicast chaddr %RTmac without broadcast flag\n", &bp->bp_chaddr.Mac));
73
74	/* we don't want to deal with forwarding */
75	if (bp->bp_giaddr.u != 0)
76	DHCP_LOG2_RET_NULL(("DhcpClientMessage::parse: giaddr %RTnaipv4\n", bp->bp_giaddr.u));
77
78	if (bp->bp_hops != 0)
79	DHCP_LOG2_RET_NULL(("DhcpClientMessage::parse: non-zero hops %d\n", bp->bp_hops));
80
81	if (bp->bp_vend.Dhcp.dhcp_cookie != RT_H2N_U32_C(RTNET_DHCP_COOKIE))
82	DHCP_LOG2_RET_NULL(("DhcpClientMessage::parse: bad cookie %#RX32\n", bp->bp_vend.Dhcp.dhcp_cookie));
83
84	/*
85	* Convert it into a DhcpClientMessage instance.
86	*/
87	std::unique_ptr<DhcpClientMessage> msg(new DhcpClientMessage());
88
89	msg->m_broadcasted = broadcasted;
90	msg->m_xid = bp->bp_xid;
91	msg->m_flags = bp->bp_flags;
92	msg->m_mac = bp->bp_chaddr.Mac;
93	msg->m_ciaddr = bp->bp_ciaddr;
94	msg->m_yiaddr = bp->bp_yiaddr;
95	msg->m_siaddr = bp->bp_siaddr;
96	msg->m_giaddr = bp->bp_giaddr;
97
98	int fOptOverload = msg->i_parseOptions(&bp->bp_vend.Dhcp.dhcp_opts[0],
99	buflen - RT_OFFSETOF(RTNETBOOTP, bp_vend.Dhcp.dhcp_opts));
100	if (fOptOverload < 0)
101	return NULL;
102
103	/* "The 'file' field MUST be interpreted next ..." */
104	if (fOptOverload & RTNET_DHCP_OPTION_OVERLOAD_FILE)
105	{
106	int status = msg->i_parseOptions(bp->bp_file, sizeof(bp->bp_file));
107	if (status != 0)
108	return NULL;
109	}
110	#if 0 /* not currently unused */
111	else if (bp->bp_file[0] != '\0')
112	{
113	/* must be zero terminated, ignore if not */
114	const char pszFile = (const char )bp->bp_file;
115	size_t len = RTStrNLen(pszFile, sizeof(bp->bp_file));
116	if (len < sizeof(bp->bp_file))
117	msg->m_file.assign(pszFile, len);
118	}
119	#endif
120
121	/* "... followed by the 'sname' field." */
122	if (fOptOverload & RTNET_DHCP_OPTION_OVERLOAD_SNAME)
123	{
124	int status = msg->i_parseOptions(bp->bp_sname, sizeof(bp->bp_sname));
125	if (status != 0) /* NB: this includes "nested" Option Overload */
126	return NULL;
127	}
128	#if 0 /* not currently unused */
129	else if (bp->bp_sname[0] != '\0')
130	{
131	/* must be zero terminated, ignore if not */
132	const char pszSName = (const char )bp->bp_sname;
133	size_t len = RTStrNLen(pszSName, sizeof(bp->bp_sname));
134	if (len < sizeof(bp->bp_sname))
135	msg->m_sname.assign(pszSName, len);
136	}
137	#endif
138
139	msg->m_optMessageType = OptMessageType(*msg);
140	if (!msg->m_optMessageType.present())
141	return NULL;
142
143	msg->m_id = ClientId(msg->m_mac, OptClientId(*msg));
144
145	return msg.release();
146	}
147
148
149	int DhcpClientMessage::i_parseOptions(const uint8_t *pbBuf, size_t cbBuf) RT_NOEXCEPT
150	{
151	int fOptOverload = 0;
152	while (cbBuf > 0)
153	{
154	uint8_t const bOpt = *pbBuf++;
155	--cbBuf;
156
157	if (bOpt == RTNET_DHCP_OPT_PAD)
158	continue;
159
160	if (bOpt == RTNET_DHCP_OPT_END)
161	break;
162
163	if (cbBuf == 0)
164	DHCP_LOG_RET(-1, ("option %d has no length field\n", bOpt));
165
166	uint8_t const cbOpt = *pbBuf++;
167	--cbBuf;
168
169	if (cbOpt > cbBuf)
170	DHCP_LOG_RET(-1, ("option %d truncated (length %d, but only %zu bytes left)\n", bOpt, cbOpt, cbBuf));
171
172	#if 0
173	rawopts_t::const_iterator it(m_optmap.find(bOpt));
174	if (it != m_optmap.cend())
175	return -1;
176	#endif
177	if (bOpt == RTNET_DHCP_OPT_OPTION_OVERLOAD)
178	{
179	if (cbOpt != 1)
180	DHCP_LOG_RET(-1, ("Overload Option (option %d) has invalid length %d\n", bOpt, cbOpt));
181
182	fOptOverload = *pbBuf;
183
184	if ((fOptOverload & ~RTNET_DHCP_OPTION_OVERLOAD_MASK) != 0)
185	DHCP_LOG_RET(-1, ("Overload Option (option %d) has invalid value 0x%x\n", bOpt, fOptOverload));
186	}
187	else
188	m_rawopts.insert(std::make_pair(bOpt, octets_t(pbBuf, pbBuf + cbOpt)));
189
190	pbBuf += cbOpt;
191	cbBuf -= cbOpt;
192	}
193
194	return fOptOverload;
195	}
196
197
198	void DhcpClientMessage::dump() const RT_NOEXCEPT
199	{
200	switch (m_optMessageType.value())
201	{
202	case RTNET_DHCP_MT_DISCOVER:
203	LogRel(("DISCOVER"));
204	break;
205
206	case RTNET_DHCP_MT_REQUEST:
207	LogRel(("REQUEST"));
208	break;
209
210	case RTNET_DHCP_MT_INFORM:
211	LogRel(("INFORM"));
212	break;
213
214	case RTNET_DHCP_MT_DECLINE:
215	LogRel(("DECLINE"));
216	break;
217
218	case RTNET_DHCP_MT_RELEASE:
219	LogRel(("RELEASE"));
220	break;
221
222	default:
223	LogRel(("<Unknown Mesage Type %d>", m_optMessageType.value()));
224	break;
225	}
226
227	if (OptRapidCommit(*this).present())
228	LogRel((" (rapid commit)"));
229
230	try
231	{
232	const OptServerId sid(*this);
233	if (sid.present())
234	LogRel((" for server %RTnaipv4", sid.value().u));
235
236	LogRel((" xid 0x%08x", m_xid));
237	LogRel((" chaddr %RTmac\n", &m_mac));
238
239	const OptClientId cid(*this);
240	if (cid.present()) {
241	if (cid.value().size() > 0)
242	LogRel((" client id: %.*Rhxs\n", cid.value().size(), &cid.value().front()));
243	else
244	LogRel((" client id: <empty>\n"));
245	}
246
247	LogRel((" ciaddr %RTnaipv4", m_ciaddr.u));
248	if (m_yiaddr.u != 0)
249	LogRel((" yiaddr %RTnaipv4", m_yiaddr.u));
250	if (m_siaddr.u != 0)
251	LogRel((" siaddr %RTnaipv4", m_siaddr.u));
252	if (m_giaddr.u != 0)
253	LogRel((" giaddr %RTnaipv4", m_giaddr.u));
254	LogRel(("%s\n", broadcast() ? "broadcast" : ""));
255
256
257	const OptRequestedAddress reqAddr(*this);
258	if (reqAddr.present())
259	LogRel((" requested address %RTnaipv4", reqAddr.value().u));
260	const OptLeaseTime reqLeaseTime(*this);
261	if (reqLeaseTime.present())
262	LogRel((" requested lease time %d", reqAddr.value()));
263	if (reqAddr.present() \|\| reqLeaseTime.present())
264	LogRel(("\n"));
265
266	const OptParameterRequest params(*this);
267	if (params.present())
268	{
269	LogRel((" params {"));
270	typedef OptParameterRequest::value_t::const_iterator it_t;
271	for (it_t it = params.value().begin(); it != params.value().end(); ++it)
272	LogRel((" %d", *it));
273	LogRel((" }\n"));
274	}
275	}
276	catch (std::bad_alloc &)
277	{
278	LogRel(("bad_alloc during dumping\n"));
279	}
280
281	bool fHeader = true;
282	for (rawopts_t::const_iterator it = m_rawopts.begin(); it != m_rawopts.end(); ++it)
283	{
284	const uint8_t optcode = (*it).first;
285	switch (optcode)
286	{
287	case OptMessageType::optcode: /* FALLTHROUGH */
288	case OptClientId::optcode: /* FALLTHROUGH */
289	case OptRequestedAddress::optcode: /* FALLTHROUGH */
290	case OptLeaseTime::optcode: /* FALLTHROUGH */
291	case OptParameterRequest::optcode: /* FALLTHROUGH */
292	case OptRapidCommit::optcode:
293	break;
294
295	default:
296	if (fHeader)
297	{
298	LogRel((" other options:"));
299	fHeader = false;
300	}
301	LogRel((" %d", optcode));
302	break;
303	}
304	}
305	if (!fHeader)
306	LogRel(("\n"));
307	}
308
309
310
311	/*********************************************************************************************************************************
312	* DhcpServerMessage Implementation *
313	*********************************************************************************************************************************/
314
315	DhcpServerMessage::DhcpServerMessage(const DhcpClientMessage &req, uint8_t messageTypeParam, RTNETADDRIPV4 serverAddr)
316	: DhcpMessage()
317	, m_optServerId(serverAddr)
318	{
319	m_dst.u = 0xffffffff; /* broadcast */
320
321	m_optMessageType = OptMessageType(messageTypeParam);
322
323	/* copy values from the request (cf. RFC2131 Table 3) */
324	m_xid = req.xid();
325	m_flags = req.flags();
326	m_giaddr = req.giaddr();
327	m_mac = req.mac();
328
329	if (req.messageType() == RTNET_DHCP_MT_REQUEST)
330	m_ciaddr = req.ciaddr();
331	}
332
333
334	void DhcpServerMessage::maybeUnicast(const DhcpClientMessage &req) RT_NOEXCEPT
335	{
336	if (!req.broadcast() && req.ciaddr().u != 0)
337	setDst(req.ciaddr());
338	}
339
340
341	/**
342	* @throws std::bad_alloc
343	*/
344	void DhcpServerMessage::addOption(DhcpOption *opt)
345	{
346	m_optmap << opt;
347	}
348
349
350	/**
351	* @throws std::bad_alloc
352	*/
353	void DhcpServerMessage::addOptions(const optmap_t &optmap)
354	{
355	for (optmap_t::const_iterator it( optmap.begin() ); it != optmap.end(); ++it)
356	m_optmap << it->second;
357	}
358
359
360	/**
361	* @throws std::bad_alloc
362	*/
363	int DhcpServerMessage::encode(octets_t &data)
364	{
365	/*
366	* Header, including DHCP cookie.
367	*/
368	RTNETBOOTP bp;
369	RT_ZERO(bp);
370
371	bp.bp_op = RTNETBOOTP_OP_REPLY;
372	bp.bp_htype = RTNET_ARP_ETHER;
373	bp.bp_hlen = sizeof(RTMAC);
374
375	bp.bp_xid = m_xid;
376
377	bp.bp_ciaddr = m_ciaddr;
378	bp.bp_yiaddr = m_yiaddr;
379	bp.bp_siaddr = m_siaddr;
380	bp.bp_giaddr = m_giaddr;
381
382	bp.bp_chaddr.Mac = m_mac;
383
384	bp.bp_vend.Dhcp.dhcp_cookie = RT_H2N_U32_C(RTNET_DHCP_COOKIE);
385
386	data.insert(data.end(), (uint8_t )&bp, (uint8_t )&bp.bp_vend.Dhcp.dhcp_opts);
387
388	/*
389	* Options
390	*/
391	data << m_optServerId
392	<< m_optMessageType;
393
394	for (optmap_t::const_iterator it ( m_optmap.begin() );
395	it != m_optmap.end(); ++it)
396	{
397	LogRel3(("encoding option %d\n", it->first));
398	DhcpOption &opt = *it->second;
399	data << opt;
400	}
401
402	data << OptEnd();
403
404	AssertCompile(RTNET_DHCP_NORMAL_SIZE == 548);
405	if (data.size() < RTNET_DHCP_NORMAL_SIZE) /* XXX */
406	data.resize(RTNET_DHCP_NORMAL_SIZE);
407
408	return VINF_SUCCESS;
409	}

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source: vbox/trunk/src/VBox/NetworkServices/Dhcpd/DhcpMessage.cpp@ 79761

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