resolv_conf_parser.c@ 69500

Last change on this file since 69500 was 69500, checked in by vboxsync, 7 years ago
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1	/* $Id: resolv_conf_parser.c 69500 2017-10-28 15:14:05Z vboxsync $ */
2	/** @file
3	* resolv_conf_parser.c - parser of resolv.conf resolver(5)
4	*/
5
6	/*
7	* Copyright (C) 2016-2017 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	#ifdef RCP_STANDALONE
19	#define IN_RING3
20	#endif
21
22	#ifndef LOG_GROUP
23	# define LOG_GROUP LOG_GROUP_DRV_NAT
24	#endif
25
26	#include <iprt/assert.h>
27	#include <iprt/net.h>
28	#include <iprt/string.h>
29	#include <iprt/stream.h>
30	#include <iprt/thread.h>
31
32	#include <VBox/log.h>
33
34	#ifdef RT_OS_FREEBSD
35	# include <sys/socket.h>
36	#endif
37
38	#include <arpa/inet.h>
39
40	#include "resolv_conf_parser.h"
41
42	#if !defined(RCP_ACCEPT_PORT)
43	# if defined(RT_OS_DARWIN)
44	# define RCP_ACCEPT_PORT
45	# endif
46	#endif
47
48	static int rcp_address_trailer(char **ppszNext, PRTNETADDR pNetAddr, RTNETADDRTYPE enmType);
49	static char getToken(char psz, char **ppszSavePtr);
50
51	#if 0
52	#undef Log2
53	#define Log2 LogRel
54	#endif
55
56	#ifdef RCP_STANDALONE
57	#undef LogRel
58	#define LogRel(a) RTPrintf a
59	#endif
60
61
62	#ifdef RCP_STANDALONE
63	int main(int argc, char **argv)
64	{
65	struct rcp_state state;
66	int i;
67	int rc;
68
69	rc = rcp_parse(&state, NULL);
70	if (RT_FAILURE(rc))
71	{
72	RTPrintf(">>> Failed: %Rrc\n", rc);
73	return 1;
74	}
75
76	RTPrintf(">>> Success:\n");
77
78	RTPrintf("rcps_num_nameserver = %u\n", state.rcps_num_nameserver);
79	for (i = 0; i < state.rcps_num_nameserver; ++i)
80	{
81	if (state.rcps_str_nameserver[i] == NULL)
82	LogRel((" nameserver %RTnaddr\n",
83	&state.rcps_nameserver[i]));
84	else
85	LogRel((" nameserver %RTnaddr (from \"%s\")\n",
86	&state.rcps_nameserver[i], state.rcps_str_nameserver[i]));
87	}
88
89	if (state.rcps_domain != NULL)
90	RTPrintf("domain %s\n", state.rcps_domain);
91
92	RTPrintf("rcps_num_searchlist = %u\n", state.rcps_num_searchlist);
93	for (i = 0; i < state.rcps_num_searchlist; ++i)
94	{
95	RTPrintf("... %s\n", state.rcps_searchlist[i] ? state.rcps_searchlist[i] : "(null)");
96	}
97
98	return 0;
99	}
100	#endif
101
102
103	int rcp_parse(struct rcp_state state, const char filename)
104	{
105	PRTSTREAM stream;
106	# define RCP_BUFFER_SIZE 256
107	char buf[RCP_BUFFER_SIZE];
108	char *pszAddrBuf;
109	size_t cbAddrBuf;
110	char *pszSearchBuf;
111	size_t cbSearchBuf;
112	uint32_t flags;
113	#ifdef RCP_ACCEPT_PORT /* OS X extention */
114	uint32_t default_port = RTNETADDR_PORT_NA;
115	#endif
116	unsigned i;
117	int rc;
118
119	AssertPtrReturn(state, VERR_INVALID_PARAMETER);
120	flags = state->rcps_flags;
121
122	RT_ZERO(*state);
123	state->rcps_flags = flags;
124
125	if (RT_UNLIKELY(filename == NULL))
126	{
127	#ifdef RCP_STANDALONE
128	stream = g_pStdIn; /* for testing/debugging */
129	#else
130	return VERR_INVALID_PARAMETER;
131	#endif
132	}
133	else
134	{
135	rc = RTStrmOpen(filename, "r", &stream);
136	if (RT_FAILURE(rc))
137	return rc;
138	}
139
140
141	pszAddrBuf = state->rcps_nameserver_str_buffer;
142	cbAddrBuf = sizeof(state->rcps_nameserver_str_buffer);
143
144	pszSearchBuf = state->rcps_searchlist_buffer;
145	cbSearchBuf = sizeof(state->rcps_searchlist_buffer);
146
147	for (;;)
148	{
149	char s, tok;
150
151	rc = RTStrmGetLine(stream, buf, sizeof(buf));
152	if (RT_FAILURE(rc))
153	{
154	if (rc == VERR_EOF)
155	rc = VINF_SUCCESS;
156	break;
157	}
158
159	/*
160	* Strip comment if present.
161	*
162	* This is not how ad-hoc parser in bind's res_init.c does it,
163	* btw, so this code will accept more input as valid compared
164	* to res_init. (e.g. "nameserver 1.1.1.1; comment" is
165	* misparsed by res_init).
166	*/
167	for (s = buf; *s != '\0'; ++s)
168	{
169	if (s == '#' \|\| s == ';')
170	{
171	*s = '\0';
172	break;
173	}
174	}
175
176	tok = getToken(buf, &s);
177	if (tok == NULL)
178	continue;
179
180
181	/*
182	* NAMESERVER
183	*/
184	if (RTStrCmp(tok, "nameserver") == 0)
185	{
186	RTNETADDR NetAddr;
187	const char *pszAddr;
188	char *pszNext;
189
190	if (RT_UNLIKELY(state->rcps_num_nameserver >= RCPS_MAX_NAMESERVERS))
191	{
192	LogRel(("NAT: resolv.conf: too many nameserver lines, ignoring %s\n", s));
193	continue;
194	}
195
196	/* XXX: TODO: don't save strings unless asked to */
197	if (RT_UNLIKELY(cbAddrBuf == 0))
198	{
199	LogRel(("NAT: resolv.conf: no buffer space, ignoring %s\n", s));
200	continue;
201	}
202
203
204	/*
205	* parse next token as an IP address
206	*/
207	tok = getToken(NULL, &s);
208	if (tok == NULL)
209	{
210	LogRel(("NAT: resolv.conf: nameserver line without value\n"));
211	continue;
212	}
213
214	pszAddr = tok;
215	RT_ZERO(NetAddr);
216	NetAddr.uPort = RTNETADDR_PORT_NA;
217
218	/* if (NetAddr.enmType == RTNETADDRTYPE_INVALID) */
219	{
220	rc = RTNetStrToIPv4AddrEx(tok, &NetAddr.uAddr.IPv4, &pszNext);
221	if (RT_SUCCESS(rc))
222	{
223	rc = rcp_address_trailer(&pszNext, &NetAddr, RTNETADDRTYPE_IPV4);
224	if (RT_FAILURE(rc))
225	{
226	LogRel(("NAT: resolv.conf: garbage at the end of IPv4 address %s\n", tok));
227	continue;
228	}
229
230	LogRel(("NAT: resolv.conf: nameserver %RTnaddr\n", &NetAddr));
231	}
232	} /* IPv4 */
233
234	if (NetAddr.enmType == RTNETADDRTYPE_INVALID)
235	{
236	rc = RTNetStrToIPv6AddrEx(tok, &NetAddr.uAddr.IPv6, &pszNext);
237	if (RT_SUCCESS(rc))
238	{
239	if (pszNext == '%') / XXX: TODO: IPv6 zones */
240	{
241	size_t zlen = RTStrOffCharOrTerm(pszNext, '.');
242	LogRel(("NAT: resolv.conf: FIXME: ignoring IPv6 zone %.s\n",
243	zlen, zlen, pszNext));
244	pszNext += zlen;
245	}
246
247	rc = rcp_address_trailer(&pszNext, &NetAddr, RTNETADDRTYPE_IPV6);
248	if (RT_FAILURE(rc))
249	{
250	LogRel(("NAT: resolv.conf: garbage at the end of IPv6 address %s\n", tok));
251	continue;
252	}
253
254	LogRel(("NAT: resolv.conf: nameserver %RTnaddr\n", &NetAddr));
255	}
256	} /* IPv6 */
257
258	if (NetAddr.enmType == RTNETADDRTYPE_INVALID)
259	{
260	LogRel(("NAT: resolv.conf: bad nameserver address %s\n", tok));
261	continue;
262	}
263
264
265	tok = getToken(NULL, &s);
266	if (tok != NULL)
267	LogRel(("NAT: resolv.conf: ignoring unexpected trailer on the nameserver line\n"));
268
269	if ((flags & RCPSF_IGNORE_IPV6) && NetAddr.enmType == RTNETADDRTYPE_IPV6)
270	{
271	Log2(("NAT: resolv.conf: IPv6 address ignored\n"));
272	continue;
273	}
274
275	/* seems ok, save it */
276	{
277	i = state->rcps_num_nameserver;
278
279	state->rcps_nameserver[i] = NetAddr;
280
281	/* XXX: TODO: don't save strings unless asked to */
282	Log2(("NAT: resolv.conf: saving address @%td,+%zu\n",
283	pszAddrBuf - state->rcps_nameserver_str_buffer, cbAddrBuf));
284	state->rcps_str_nameserver[i] = pszAddrBuf;
285	rc = RTStrCopyP(&pszAddrBuf, &cbAddrBuf, pszAddr);
286	if (RT_SUCCESS(rc))
287	{
288	++pszAddrBuf; /* skip '\0' */
289	if (cbAddrBuf > 0) /* on overflow we get 1 (for the '\0'), but be defensive */
290	--cbAddrBuf;
291	++state->rcps_num_nameserver;
292	}
293	else
294	{
295	Log2(("NAT: resolv.conf: ... truncated\n"));
296	}
297	}
298
299	continue;
300	}
301
302
303	#ifdef RCP_ACCEPT_PORT /* OS X extention */
304	/*
305	* PORT
306	*/
307	if (RTStrCmp(tok, "port") == 0)
308	{
309	uint16_t port;
310
311	if (default_port != RTNETADDR_PORT_NA)
312	{
313	LogRel(("NAT: resolv.conf: ignoring multiple port lines\n"));
314	continue;
315	}
316
317	tok = getToken(NULL, &s);
318	if (tok == NULL)
319	{
320	LogRel(("NAT: resolv.conf: port line without value\n"));
321	continue;
322	}
323
324	rc = RTStrToUInt16Full(tok, 10, &port);
325	if (RT_SUCCESS(rc))
326	{
327	if (port != 0)
328	default_port = port;
329	else
330	LogRel(("NAT: resolv.conf: port 0 is invalid\n"));
331	}
332
333	continue;
334	}
335	#endif
336
337
338	/*
339	* DOMAIN
340	*/
341	if (RTStrCmp(tok, "domain") == 0)
342	{
343	if (state->rcps_domain != NULL)
344	{
345	LogRel(("NAT: resolv.conf: ignoring multiple domain lines\n"));
346	continue;
347	}
348
349	tok = getToken(NULL, &s);
350	if (tok == NULL)
351	{
352	LogRel(("NAT: resolv.conf: domain line without value\n"));
353	continue;
354	}
355
356	rc = RTStrCopy(state->rcps_domain_buffer, sizeof(state->rcps_domain_buffer), tok);
357	if (RT_SUCCESS(rc))
358	{
359	state->rcps_domain = state->rcps_domain_buffer;
360	}
361	else
362	{
363	LogRel(("NAT: resolv.conf: domain name too long\n"));
364	RT_ZERO(state->rcps_domain_buffer);
365	}
366
367	continue;
368	}
369
370
371	/*
372	* SEARCH
373	*/
374	if (RTStrCmp(tok, "search") == 0)
375	{
376	while ((tok = getToken(NULL, &s)) && tok != NULL)
377	{
378	i = state->rcps_num_searchlist;
379	if (RT_UNLIKELY(i >= RCPS_MAX_SEARCHLIST))
380	{
381	LogRel(("NAT: resolv.conf: too many search domains, ignoring %s\n", tok));
382	continue;
383	}
384
385	Log2(("NAT: resolv.conf: saving search %s @%td,+%zu\n",
386	tok, pszSearchBuf - state->rcps_searchlist_buffer, cbSearchBuf));
387	state->rcps_searchlist[i] = pszSearchBuf;
388	rc = RTStrCopyP(&pszSearchBuf, &cbSearchBuf, tok);
389	if (RT_SUCCESS(rc))
390	{
391	++pszSearchBuf; /* skip '\0' */
392	if (cbSearchBuf > 0) /* on overflow we get 1 (for the '\0'), but be defensive */
393	--cbSearchBuf;
394	++state->rcps_num_searchlist;
395	}
396	else
397	{
398	LogRel(("NAT: resolv.conf: no buffer space, ignoring search domain %s\n", tok));
399	pszSearchBuf = state->rcps_searchlist[i];
400	cbSearchBuf = sizeof(state->rcps_searchlist_buffer)
401	- (pszSearchBuf - state->rcps_searchlist_buffer);
402	Log2(("NAT: resolv.conf: backtracking to @%td,+%zu\n",
403	pszSearchBuf - state->rcps_searchlist_buffer, cbSearchBuf));
404	}
405	}
406
407	continue;
408	}
409
410
411	LogRel(("NAT: resolv.conf: ignoring \"%s %s\"\n", tok, s));
412	}
413
414	if (filename != NULL)
415	RTStrmClose(stream);
416
417	if (RT_FAILURE(rc))
418	return rc;
419
420
421	/* XXX: I don't like that OS X would return a different result here */
422	#ifdef RCP_ACCEPT_PORT /* OS X extention */
423	if (default_port == RTNETADDR_PORT_NA)
424	default_port = 53;
425
426	for (i = 0; i < state->rcps_num_nameserver; ++i)
427	{
428	RTNETADDR *addr = &state->rcps_nameserver[i];
429	if (addr->uPort == RTNETADDR_PORT_NA \|\| addr->uPort == 0)
430	addr->uPort = (uint16_t)default_port;
431	}
432	#endif
433
434	if ( state->rcps_domain == NULL
435	&& state->rcps_num_searchlist > 0)
436	{
437	state->rcps_domain = state->rcps_searchlist[0];
438	}
439
440	return VINF_SUCCESS;
441	}
442
443
444	static int
445	rcp_address_trailer(char **ppszNext, PRTNETADDR pNetAddr, RTNETADDRTYPE enmType)
446	{
447	char pszNext = ppszNext;
448	int rc = VINF_SUCCESS;
449
450	if (*pszNext == '\0')
451	{
452	pNetAddr->enmType = enmType;
453	rc = VINF_SUCCESS;
454	}
455	#ifdef RCP_ACCEPT_PORT /* OS X extention */
456	else if (*pszNext == '.')
457	{
458	uint16_t port;
459
460	rc = RTStrToUInt16Ex(++pszNext, NULL, 10, &port);
461	if (RT_SUCCESS(rc))
462	{
463	pNetAddr->enmType = enmType;
464	pNetAddr->uPort = port;
465	}
466	}
467	#endif
468	else
469	{
470	rc = VERR_TRAILING_CHARS;
471	}
472
473	return rc;
474	}
475
476
477	static char getToken(char psz, char **ppszSavePtr)
478	{
479	char *pszToken;
480
481	AssertPtrReturn(ppszSavePtr, NULL);
482
483	if (psz == NULL)
484	{
485	psz = *ppszSavePtr;
486	if (psz == NULL)
487	return NULL;
488	}
489
490	while (psz == ' ' \|\| psz == '\t')
491	++psz;
492
493	if (*psz == '\0')
494	{
495	*ppszSavePtr = NULL;
496	return NULL;
497	}
498
499	pszToken = psz;
500	while (psz && psz != ' ' && *psz != '\t')
501	++psz;
502
503	if (*psz == '\0')
504	psz = NULL;
505	else
506	*psz++ = '\0';
507
508	*ppszSavePtr = psz;
509	return pszToken;
510	}

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source: vbox/trunk/src/VBox/Devices/Network/slirp/resolv_conf_parser.c@ 69500

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