Db.cpp@ 71512

Last change on this file since 71512 was 71512, checked in by vboxsync, 7 years ago
Binding::fromXML - don't leak memory.
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File size: 19.3 KB

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1	/* $Id: Db.cpp 71512 2018-03-26 14:02:50Z vboxsync $ */
2	/** @file
3	* DHCP server - address database
4	*/
5
6	/*
7	* Copyright (C) 2017-2018 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	#include <iprt/err.h>
19	#include <iprt/stream.h>
20
21	#include <algorithm>
22	#include <functional>
23
24	#include "Db.h"
25
26
27	Db::~Db()
28	{
29	/** @todo free bindings */
30	}
31
32
33	int Db::init(const Config *pConfig)
34	{
35	Binding::registerFormat();
36
37	m_pConfig = pConfig;
38
39	m_pool.init(pConfig->getIPv4PoolFirst(),
40	pConfig->getIPv4PoolLast());
41
42	return VINF_SUCCESS;
43	}
44
45
46	bool Binding::g_fFormatRegistered = false;
47
48
49	void Binding::registerFormat()
50	{
51	if (g_fFormatRegistered)
52	return;
53
54	int rc = RTStrFormatTypeRegister("binding", rtStrFormat, NULL);
55	AssertRC(rc);
56
57	g_fFormatRegistered = true;
58	}
59
60
61	DECLCALLBACK(size_t)
62	Binding::rtStrFormat(PFNRTSTROUTPUT pfnOutput, void *pvArgOutput,
63	const char pszType, void const pvValue,
64	int cchWidth, int cchPrecision, unsigned fFlags,
65	void *pvUser)
66	{
67	const Binding b = static_cast<const Binding >(pvValue);
68	size_t cb = 0;
69
70	AssertReturn(strcmp(pszType, "binding") == 0, 0);
71	RT_NOREF(pszType);
72
73	RT_NOREF(cchWidth, cchPrecision, fFlags);
74	RT_NOREF(pvUser);
75
76	if (b == NULL)
77	{
78	return RTStrFormat(pfnOutput, pvArgOutput, NULL, 0,
79	"<NULL>");
80	}
81
82	cb += RTStrFormat(pfnOutput, pvArgOutput, NULL, 0,
83	"%RTnaipv4", b->m_addr.u);
84
85	if (b->m_state == Binding::FREE)
86	{
87	cb += RTStrFormat(pfnOutput, pvArgOutput, NULL, 0,
88	" free");
89	}
90	else
91	{
92	cb += RTStrFormat(pfnOutput, pvArgOutput, NULL, 0,
93	" to %R[id], %s, valid from ",
94	&b->m_id, b->stateName());
95
96	TimeStamp tsIssued = b->issued();
97	cb += tsIssued.absStrFormat(pfnOutput, pvArgOutput);
98
99	cb += RTStrFormat(pfnOutput, pvArgOutput, NULL, 0,
100	" for %ds until ",
101	b->leaseTime());
102
103	TimeStamp tsValid = b->issued();
104	tsValid.addSeconds(b->leaseTime());
105	cb += tsValid.absStrFormat(pfnOutput, pvArgOutput);
106	}
107
108	return cb;
109	}
110
111	const char *Binding::stateName() const
112	{
113	switch (m_state) {
114	case FREE:
115	return "free";
116	case RELEASED:
117	return "released";
118	case EXPIRED:
119	return "expired";
120	case OFFERED:
121	return "offered";
122	case ACKED:
123	return "acked";
124	default:
125	return "released";
126	}
127	}
128
129
130	Binding &Binding::setState(const char *pszStateName)
131	{
132	if (strcmp(pszStateName, "free") == 0)
133	m_state = Binding::FREE;
134	else if (strcmp(pszStateName, "released") == 0)
135	m_state = Binding::RELEASED;
136	else if (strcmp(pszStateName, "expired") == 0)
137	m_state = Binding::EXPIRED;
138	else if (strcmp(pszStateName, "offered") == 0)
139	m_state = Binding::OFFERED;
140	else if (strcmp(pszStateName, "acked") == 0)
141	m_state = Binding::ACKED;
142	else
143	m_state = Binding::RELEASED;
144
145	return *this;
146	}
147
148
149	bool Binding::expire(TimeStamp deadline)
150	{
151	if (m_state <= Binding::EXPIRED)
152	return false;
153
154	TimeStamp t = m_issued;
155	t.addSeconds(m_secLease);
156
157	if (t < deadline)
158	{
159	if (m_state == Binding::OFFERED)
160	setState(Binding::FREE);
161	else
162	setState(Binding::EXPIRED);
163	}
164	return true;
165	}
166
167
168	int Binding::toXML(xml::ElementNode *ndParent) const
169	{
170	int rc;
171
172	/*
173	* Lease
174	*/
175	xml::ElementNode *ndLease = ndParent->createChild("Lease");
176	if (ndLease == NULL)
177	return VERR_GENERAL_FAILURE;
178
179	/* XXX: arrange for lease to get deleted if anything below fails */
180
181
182	ndLease->setAttribute("mac", RTCStringFmt("%RTmac", &m_id.mac()));
183	if (m_id.id().present())
184	{
185	/* I'd prefer RTSTRPRINTHEXBYTES_F_SEP_COLON but there's no decoder */
186	size_t cbStrId = m_id.id().value().size() * 2 + 1;
187	char *pszId = new char[cbStrId];
188	rc = RTStrPrintHexBytes(pszId, cbStrId,
189	&m_id.id().value().front(), m_id.id().value().size(),
190	0);
191	ndLease->setAttribute("id", pszId);
192	delete[] pszId;
193	}
194
195	/* unused but we need it to keep the old code happy */
196	ndLease->setAttribute("network", "0.0.0.0");
197
198	ndLease->setAttribute("state", stateName());
199
200
201	/*
202	* Lease/Address
203	*/
204	xml::ElementNode *ndAddr = ndLease->createChild("Address");
205	ndAddr->setAttribute("value", RTCStringFmt("%RTnaipv4", m_addr.u));
206
207
208	/*
209	* Lease/Time
210	*/
211	xml::ElementNode *ndTime = ndLease->createChild("Time");
212	ndTime->setAttribute("issued", m_issued.getAbsSeconds());
213	ndTime->setAttribute("expiration", m_secLease);
214
215	return VINF_SUCCESS;
216	}
217
218
219	Binding Binding::fromXML(const xml::ElementNode ndLease)
220	{
221	int rc;
222
223	/* Lease/@network seems to always have bogus value, ignore it. */
224
225	/*
226	* Lease/@mac
227	*/
228	RTCString strMac;
229	bool fHasMac = ndLease->getAttributeValue("mac", &strMac);
230	if (!fHasMac)
231	return NULL;
232
233	RTMAC mac;
234	rc = RTNetStrToMacAddr(strMac.c_str(), &mac);
235	if (RT_FAILURE(rc))
236	return NULL;
237
238	OptClientId id;
239	RTCString strId;
240	bool fHasId = ndLease->getAttributeValue("id", &strId);
241	if (fHasId)
242	{
243	/*
244	* Decode from "de:ad:be:ef".
245	* XXX: RTStrConvertHexBytes() doesn't grok colons
246	*/
247	size_t cbBytes = strId.length() / 2;
248	uint8_t *pBytes = new uint8_t[cbBytes];
249	rc = RTStrConvertHexBytes(strId.c_str(), pBytes, cbBytes, 0);
250	if (RT_SUCCESS(rc))
251	{
252	std::vector<uint8_t> rawopt(pBytes, pBytes + cbBytes);
253	id = OptClientId(rawopt);
254	}
255	delete[] pBytes;
256	}
257
258	/*
259	* Lease/@state - not present in old leases file. We will try to
260	* infer from lease time below.
261	*/
262	RTCString strState;
263	bool fHasState = ndLease->getAttributeValue("state", &strState);
264
265	/*
266	* Lease/Address
267	*/
268	const xml::ElementNode *ndAddress = ndLease->findChildElement("Address");
269	if (ndAddress == NULL)
270	return NULL;
271
272	/*
273	* Lease/Address/@value
274	*/
275	RTCString strAddress;
276	bool fHasValue = ndAddress->getAttributeValue("value", &strAddress);
277	if (!fHasValue)
278	return NULL;
279
280	RTNETADDRIPV4 addr;
281	rc = RTNetStrToIPv4Addr(strAddress.c_str(), &addr);
282	if (RT_FAILURE(rc))
283	return NULL;
284
285	/*
286	* Lease/Time
287	*/
288	const xml::ElementNode *ndTime = ndLease->findChildElement("Time");
289	if (time == NULL)
290	return NULL;
291
292	/*
293	* Lease/Time/@issued
294	*/
295	int64_t issued;
296	bool fHasIssued = ndTime->getAttributeValue("issued", &issued);
297	if (!fHasIssued)
298	return NULL;
299
300	/*
301	* Lease/Time/@expiration
302	*/
303	uint32_t duration;
304	bool fHasExpiration = ndTime->getAttributeValue("expiration", &duration);
305	if (!fHasExpiration)
306	return NULL;
307
308	std::unique_ptr<Binding> b(new Binding(addr));
309	b->m_id = ClientId(mac, id);
310
311	if (fHasState)
312	{
313	b->m_issued = TimeStamp::absSeconds(issued);
314	b->m_secLease = duration;
315	b->setState(strState.c_str());
316	}
317	else
318	{ /* XXX: old code wrote timestamps instead of absolute time. */
319	/* pretend that lease has just ended */
320	TimeStamp fakeIssued = TimeStamp::now();
321	fakeIssued.subSeconds(duration);
322	b->m_issued = fakeIssued;
323	b->m_secLease = duration;
324	b->m_state = Binding::EXPIRED;
325	}
326
327	return b.release();
328	}
329
330
331	void Db::expire()
332	{
333	const TimeStamp now = TimeStamp::now();
334
335	for (bindings_t::iterator it = m_bindings.begin();
336	it != m_bindings.end(); ++it)
337	{
338	Binding b = it;
339	b->expire(now);
340	}
341	}
342
343
344	Binding *Db::bindingById(const ClientId &id) const
345	{
346	struct ClientMatch : public Binding::Match {
347	const ClientId &m_id;
348	ClientMatch(const ClientId &id) : m_id(id) {}
349
350	bool operator()(const Binding *b)
351	{
352	return b->m_id == m_id;
353	}
354	};
355
356	bindings_t::const_iterator found =
357	std::find_if(m_bindings.begin(), m_bindings.end(),
358	ClientMatch(id));
359
360	if (found == m_bindings.end())
361	return NULL;
362
363	Binding b = found;
364	return b;
365	}
366
367
368	Binding *Db::bindingByAddr(RTNETADDRIPV4 addr) const
369	{
370	struct AddrMatch : public Binding::Match {
371	const RTNETADDRIPV4 m_addr;
372	AddrMatch(RTNETADDRIPV4 addr) : m_addr(addr) {}
373
374	bool operator()(const Binding *b)
375	{
376	return b->m_addr.u == m_addr.u;
377	}
378	};
379
380	bindings_t::const_iterator found =
381	std::find_if(m_bindings.begin(), m_bindings.end(),
382	AddrMatch(addr));
383
384	if (found == m_bindings.end())
385	return NULL;
386
387	Binding b = found;
388	return b;
389	}
390
391
392
393	Binding *Db::createBinding(const ClientId &id)
394	{
395	RTNETADDRIPV4 addr = m_pool.allocate();
396	if (addr.u == 0)
397	return NULL;
398
399	Binding *b = new Binding(addr, id);
400	m_bindings.push_front(b);
401	return b;
402	}
403
404
405	Binding *Db::createBinding(RTNETADDRIPV4 addr, const ClientId &id)
406	{
407	bool fAvailable = m_pool.allocate(addr);
408	if (!fAvailable)
409	{
410	/*
411	* XXX: this should not happen. If the address is from the
412	* pool, which we have verified before, then either it's in
413	* the free pool or there's an binding (possibly free) for it.
414	*/
415	return NULL;
416	}
417
418	Binding *b = new Binding(addr, id);
419	m_bindings.push_front(b);
420	return b;
421	}
422
423
424	Binding *Db::allocateAddress(const ClientId &id, RTNETADDRIPV4 addr)
425	{
426	Assert(addr.u == 0 \|\| addressBelongs(addr));
427
428	Binding *addrBinding = NULL;
429	Binding *freeBinding = NULL;
430	Binding *reuseBinding = NULL;
431
432	if (addr.u != 0)
433	LogDHCP(("> allocateAddress %RTnaipv4 to client %R[id]\n", addr.u, &id));
434	else
435	LogDHCP(("> allocateAddress to client %R[id]\n", &id));
436
437	/*
438	* Allocate existing address if client has one. Ignore requested
439	* address in that case. While here, look for free addresses and
440	* addresses that can be reused.
441	*/
442	const TimeStamp now = TimeStamp::now();
443	for (bindings_t::iterator it = m_bindings.begin();
444	it != m_bindings.end(); ++it)
445	{
446	Binding b = it;
447	b->expire(now);
448
449	/*
450	* We've already seen this client, give it its old binding.
451	*/
452	if (b->m_id == id)
453	{
454	LogDHCP(("> ... found existing binding %R[binding]\n", b));
455	return b;
456	}
457
458	if (addr.u != 0 && b->m_addr.u == addr.u)
459	{
460	Assert(addrBinding == NULL);
461	addrBinding = b;
462	LogDHCP(("> .... noted existing binding %R[binding]\n", addrBinding));
463	}
464
465	/* if we haven't found a free binding yet, keep looking */
466	if (freeBinding == NULL)
467	{
468	if (b->m_state == Binding::FREE)
469	{
470	freeBinding = b;
471	LogDHCP(("> .... noted free binding %R[binding]\n", freeBinding));
472	continue;
473	}
474
475	/* still no free binding, can this one be reused? */
476	if (b->m_state == Binding::RELEASED)
477	{
478	if ( reuseBinding == NULL
479	/* released binding is better than an expired one */
480	\|\| reuseBinding->m_state == Binding::EXPIRED)
481	{
482	reuseBinding = b;
483	LogDHCP(("> .... noted released binding %R[binding]\n", reuseBinding));
484	}
485	}
486	else if (b->m_state == Binding::EXPIRED)
487	{
488	if ( reuseBinding == NULL
489	/* long expired binding is bettern than a recent one */
490	/* \|\| (reuseBinding->m_state == Binding::EXPIRED && b->olderThan(reuseBinding)) */)
491	{
492	reuseBinding = b;
493	LogDHCP(("> .... noted expired binding %R[binding]\n", reuseBinding));
494	}
495	}
496	}
497	}
498
499	/*
500	* Allocate requested address if we can.
501	*/
502	if (addr.u != 0)
503	{
504	if (addrBinding == NULL)
505	{
506	addrBinding = createBinding(addr, id);
507	Assert(addrBinding != NULL);
508	LogDHCP(("> .... creating new binding for this address %R[binding]\n",
509	addrBinding));
510	return addrBinding;
511	}
512
513	if (addrBinding->m_state <= Binding::EXPIRED) /* not in use */
514	{
515	LogDHCP(("> .... reusing %s binding for this address\n",
516	addrBinding->stateName()));
517	addrBinding->giveTo(id);
518	return addrBinding;
519	}
520	else
521	{
522	LogDHCP(("> .... cannot reuse %s binding for this address\n",
523	addrBinding->stateName()));
524	}
525	}
526
527	/*
528	* Allocate new (or reuse).
529	*/
530	Binding *idBinding = NULL;
531	if (freeBinding != NULL)
532	{
533	idBinding = freeBinding;
534	LogDHCP(("> .... reusing free binding\n"));
535	}
536	else
537	{
538	idBinding = createBinding();
539	if (idBinding != NULL)
540	{
541	LogDHCP(("> .... creating new binding\n"));
542	}
543	else
544	{
545	idBinding = reuseBinding;
546	LogDHCP(("> .... reusing %s binding %R[binding]\n",
547	reuseBinding->stateName()));
548	}
549	}
550
551	if (idBinding == NULL)
552	{
553	LogDHCP(("> .... failed to allocate binding\n"));
554	return NULL;
555	}
556
557	idBinding->giveTo(id);
558	LogDHCP(("> .... allocated %R[binding]\n", idBinding));
559
560	return idBinding;
561	}
562
563
564
565	Binding *Db::allocateBinding(const DhcpClientMessage &req)
566	{
567	/** @todo XXX: handle fixed address assignments */
568	OptRequestedAddress reqAddr(req);
569	if (reqAddr.present() && !addressBelongs(reqAddr.value()))
570	{
571	if (req.messageType() == RTNET_DHCP_MT_DISCOVER)
572	{
573	LogDHCP(("DISCOVER: ignoring invalid requested address\n"));
574	reqAddr = OptRequestedAddress();
575	}
576	else
577	{
578	LogDHCP(("rejecting invalid requested address\n"));
579	return NULL;
580	}
581	}
582
583	const ClientId &id(req.clientId());
584
585	Binding *b = allocateAddress(id, reqAddr.value());
586	if (b == NULL)
587	return NULL;
588
589	Assert(b->id() == id);
590	Assert(b->state() == Binding::FREE \|\| b->state() >= Binding::OFFERED);
591
592	/*
593	* XXX: handle requests for specific lease time!
594	* XXX: old lease might not have expired yet?
595	*/
596	// OptLeaseTime reqLeaseTime(req);
597	b->setLeaseTime(1200);
598	return b;
599	}
600
601
602	int Db::addBinding(Binding *newb)
603	{
604	if (!addressBelongs(newb->m_addr))
605	{
606	LogDHCP(("Binding for out of range address %RTnaipv4 ignored\n",
607	newb->m_addr.u));
608	return VERR_INVALID_PARAMETER;
609	}
610
611	for (bindings_t::iterator it = m_bindings.begin();
612	it != m_bindings.end(); ++it)
613	{
614	Binding b = it;
615
616	if (newb->m_addr.u == b->m_addr.u)
617	{
618	LogDHCP(("> ADD: %R[binding]\n", newb));
619	LogDHCP(("> .... duplicate ip: %R[binding]\n", b));
620	return VERR_INVALID_PARAMETER;
621	}
622
623	if (newb->m_id == b->m_id)
624	{
625	LogDHCP(("> ADD: %R[binding]\n", newb));
626	LogDHCP(("> .... duplicate id: %R[binding]\n", b));
627	return VERR_INVALID_PARAMETER;
628	}
629	}
630
631	bool ok = m_pool.allocate(newb->m_addr);
632	if (!ok)
633	{
634	LogDHCP(("> ADD: failed to claim IP %R[binding]\n", newb));
635	return VERR_INVALID_PARAMETER;
636	}
637
638	m_bindings.push_back(newb);
639	return VINF_SUCCESS;
640	}
641
642
643	void Db::cancelOffer(const DhcpClientMessage &req)
644	{
645	const OptRequestedAddress reqAddr(req);
646	if (!reqAddr.present())
647	return;
648
649	const RTNETADDRIPV4 addr = reqAddr.value();
650	const ClientId &id(req.clientId());
651
652	for (bindings_t::iterator it = m_bindings.begin();
653	it != m_bindings.end(); ++it)
654	{
655	Binding b = it;
656
657	if (b->addr().u == addr.u && b->id() == id)
658	{
659	if (b->state() == Binding::OFFERED)
660	{
661	b->setLeaseTime(0);
662	b->setState(Binding::RELEASED);
663	}
664	return;
665	}
666	}
667	}
668
669
670	bool Db::releaseBinding(const DhcpClientMessage &req)
671	{
672	const RTNETADDRIPV4 addr = req.ciaddr();
673	const ClientId &id(req.clientId());
674
675	for (bindings_t::iterator it = m_bindings.begin();
676	it != m_bindings.end(); ++it)
677	{
678	Binding b = it;
679
680	if (b->addr().u == addr.u && b->id() == id)
681	{
682	b->setState(Binding::RELEASED);
683	return true;
684	}
685	}
686
687	return false;
688	}
689
690
691	int Db::writeLeases(const std::string &strFileName) const
692	{
693	LogDHCP(("writing leases to %s\n", strFileName.c_str()));
694
695	xml::Document doc;
696
697	xml::ElementNode *root = doc.createRootElement("Leases");
698	if (root == NULL)
699	return VERR_INTERNAL_ERROR;
700
701	root->setAttribute("version", "1.0");
702
703	for (bindings_t::const_iterator it = m_bindings.begin();
704	it != m_bindings.end(); ++it)
705	{
706	const Binding b = it;
707	b->toXML(root);
708	}
709
710	try {
711	xml::XmlFileWriter writer(doc);
712	writer.write(strFileName.c_str(), true);
713	}
714	catch (const xml::EIPRTFailure &e)
715	{
716	LogDHCP(("%s\n", e.what()));
717	return e.rc();
718	}
719	catch (const RTCError &e)
720	{
721	LogDHCP(("%s\n", e.what()));
722	return VERR_GENERAL_FAILURE;
723	}
724	catch (...)
725	{
726	LogDHCP(("Unknown exception while writing '%s'\n",
727	strFileName.c_str()));
728	return VERR_GENERAL_FAILURE;
729	}
730
731	return VINF_SUCCESS;
732	}
733
734
735	int Db::loadLeases(const std::string &strFileName)
736	{
737	LogDHCP(("loading leases from %s\n", strFileName.c_str()));
738
739	xml::Document doc;
740	try
741	{
742	xml::XmlFileParser parser;
743	parser.read(strFileName.c_str(), doc);
744	}
745	catch (const xml::EIPRTFailure &e)
746	{
747	LogDHCP(("%s\n", e.what()));
748	return e.rc();
749	}
750	catch (const RTCError &e)
751	{
752	LogDHCP(("%s\n", e.what()));
753	return VERR_GENERAL_FAILURE;
754	}
755	catch (...)
756	{
757	LogDHCP(("Unknown exception while reading and parsing '%s'\n",
758	strFileName.c_str()));
759	return VERR_GENERAL_FAILURE;
760	}
761
762	xml::ElementNode *ndRoot = doc.getRootElement();
763	if (ndRoot == NULL \|\| !ndRoot->nameEquals("Leases"))
764	{
765	return VERR_NOT_FOUND;
766	}
767
768	xml::NodesLoop it(*ndRoot);
769	const xml::ElementNode *node;
770	while ((node = it.forAllNodes()) != NULL)
771	{
772	if (!node->nameEquals("Lease"))
773	continue;
774
775	loadLease(node);
776	}
777
778	return VINF_SUCCESS;
779	}
780
781
782	void Db::loadLease(const xml::ElementNode *ndLease)
783	{
784	Binding *b = Binding::fromXML(ndLease);
785	bool expired = b->expire();
786
787	if (!expired)
788	LogDHCP(("> LOAD: lease %R[binding]\n", b));
789	else
790	LogDHCP(("> LOAD: EXPIRED lease %R[binding]\n", b));
791
792	addBinding(b);
793	}

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source: vbox/trunk/src/VBox/NetworkServices/Dhcpd/Db.cpp@ 71512

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