resolv_conf_parser.c@ 91942

Last change on this file since 91942 was 82968, checked in by vboxsync, 5 years ago
Copyright year updates by scm.
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1	/* $Id: resolv_conf_parser.c 82968 2020-02-04 10:35:17Z vboxsync $ */
2	/** @file
3	* resolv_conf_parser.c - parser of resolv.conf resolver(5)
4	*/
5
6	/*
7	* Copyright (C) 2016-2020 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/err.h>
28	#include <iprt/net.h>
29	#include <iprt/string.h>
30	#include <iprt/stream.h>
31	#include <iprt/thread.h>
32
33	#include <VBox/log.h>
34
35	#ifdef RT_OS_FREEBSD
36	# include <sys/socket.h>
37	#endif
38
39	#include <arpa/inet.h>
40
41	#include "resolv_conf_parser.h"
42
43	#if !defined(RCP_ACCEPT_PORT)
44	# if defined(RT_OS_DARWIN)
45	# define RCP_ACCEPT_PORT
46	# endif
47	#endif
48
49	static int rcp_address_trailer(char **ppszNext, PRTNETADDR pNetAddr, RTNETADDRTYPE enmType);
50	static char getToken(char psz, char **ppszSavePtr);
51
52	#if 0
53	#undef Log2
54	#define Log2 LogRel
55	#endif
56
57	#ifdef RCP_STANDALONE
58	#undef LogRel
59	#define LogRel(a) RTPrintf a
60	#endif
61
62
63	#ifdef RCP_STANDALONE
64	int main(int argc, char **argv)
65	{
66	struct rcp_state state;
67	int i;
68	int rc;
69
70	rc = rcp_parse(&state, NULL);
71	if (RT_FAILURE(rc))
72	{
73	RTPrintf(">>> Failed: %Rrc\n", rc);
74	return 1;
75	}
76
77	RTPrintf(">>> Success:\n");
78
79	RTPrintf("rcps_num_nameserver = %u\n", state.rcps_num_nameserver);
80	for (i = 0; i < state.rcps_num_nameserver; ++i)
81	{
82	if (state.rcps_str_nameserver[i] == NULL)
83	LogRel((" nameserver %RTnaddr\n",
84	&state.rcps_nameserver[i]));
85	else
86	LogRel((" nameserver %RTnaddr (from \"%s\")\n",
87	&state.rcps_nameserver[i], state.rcps_str_nameserver[i]));
88	}
89
90	if (state.rcps_domain != NULL)
91	RTPrintf("domain %s\n", state.rcps_domain);
92
93	RTPrintf("rcps_num_searchlist = %u\n", state.rcps_num_searchlist);
94	for (i = 0; i < state.rcps_num_searchlist; ++i)
95	{
96	RTPrintf("... %s\n", state.rcps_searchlist[i] ? state.rcps_searchlist[i] : "(null)");
97	}
98
99	return 0;
100	}
101	#endif
102
103
104	int rcp_parse(struct rcp_state state, const char filename)
105	{
106	PRTSTREAM stream;
107	# define RCP_BUFFER_SIZE 256
108	char buf[RCP_BUFFER_SIZE];
109	char *pszAddrBuf;
110	size_t cbAddrBuf;
111	char *pszSearchBuf;
112	size_t cbSearchBuf;
113	uint32_t flags;
114	#ifdef RCP_ACCEPT_PORT /* OS X extention */
115	uint32_t default_port = RTNETADDR_PORT_NA;
116	#endif
117	unsigned i;
118	int rc;
119
120	AssertPtrReturn(state, VERR_INVALID_PARAMETER);
121	flags = state->rcps_flags;
122
123	RT_ZERO(*state);
124	state->rcps_flags = flags;
125
126	if (RT_UNLIKELY(filename == NULL))
127	{
128	#ifdef RCP_STANDALONE
129	stream = g_pStdIn; /* for testing/debugging */
130	#else
131	return VERR_INVALID_PARAMETER;
132	#endif
133	}
134	else
135	{
136	rc = RTStrmOpen(filename, "r", &stream);
137	if (RT_FAILURE(rc))
138	return rc;
139	}
140
141
142	pszAddrBuf = state->rcps_nameserver_str_buffer;
143	cbAddrBuf = sizeof(state->rcps_nameserver_str_buffer);
144
145	pszSearchBuf = state->rcps_searchlist_buffer;
146	cbSearchBuf = sizeof(state->rcps_searchlist_buffer);
147
148	for (;;)
149	{
150	char s, tok;
151
152	rc = RTStrmGetLine(stream, buf, sizeof(buf));
153	if (RT_FAILURE(rc))
154	{
155	if (rc == VERR_EOF)
156	rc = VINF_SUCCESS;
157	break;
158	}
159
160	/*
161	* Strip comment if present.
162	*
163	* This is not how ad-hoc parser in bind's res_init.c does it,
164	* btw, so this code will accept more input as valid compared
165	* to res_init. (e.g. "nameserver 1.1.1.1; comment" is
166	* misparsed by res_init).
167	*/
168	for (s = buf; *s != '\0'; ++s)
169	{
170	if (s == '#' \|\| s == ';')
171	{
172	*s = '\0';
173	break;
174	}
175	}
176
177	tok = getToken(buf, &s);
178	if (tok == NULL)
179	continue;
180
181
182	/*
183	* NAMESERVER
184	*/
185	if (RTStrCmp(tok, "nameserver") == 0)
186	{
187	RTNETADDR NetAddr;
188	const char *pszAddr;
189	char *pszNext;
190
191	if (RT_UNLIKELY(state->rcps_num_nameserver >= RCPS_MAX_NAMESERVERS))
192	{
193	LogRel(("NAT: resolv.conf: too many nameserver lines, ignoring %s\n", s));
194	continue;
195	}
196
197	/* XXX: TODO: don't save strings unless asked to */
198	if (RT_UNLIKELY(cbAddrBuf == 0))
199	{
200	LogRel(("NAT: resolv.conf: no buffer space, ignoring %s\n", s));
201	continue;
202	}
203
204
205	/*
206	* parse next token as an IP address
207	*/
208	tok = getToken(NULL, &s);
209	if (tok == NULL)
210	{
211	LogRel(("NAT: resolv.conf: nameserver line without value\n"));
212	continue;
213	}
214
215	pszAddr = tok;
216	RT_ZERO(NetAddr);
217	NetAddr.uPort = RTNETADDR_PORT_NA;
218
219	/* if (NetAddr.enmType == RTNETADDRTYPE_INVALID) */
220	{
221	rc = RTNetStrToIPv4AddrEx(tok, &NetAddr.uAddr.IPv4, &pszNext);
222	if (RT_SUCCESS(rc))
223	{
224	rc = rcp_address_trailer(&pszNext, &NetAddr, RTNETADDRTYPE_IPV4);
225	if (RT_FAILURE(rc))
226	{
227	LogRel(("NAT: resolv.conf: garbage at the end of IPv4 address %s\n", tok));
228	continue;
229	}
230
231	LogRel(("NAT: resolv.conf: nameserver %RTnaddr\n", &NetAddr));
232	}
233	} /* IPv4 */
234
235	if (NetAddr.enmType == RTNETADDRTYPE_INVALID)
236	{
237	rc = RTNetStrToIPv6AddrEx(tok, &NetAddr.uAddr.IPv6, &pszNext);
238	if (RT_SUCCESS(rc))
239	{
240	if (pszNext == '%') / XXX: TODO: IPv6 zones */
241	{
242	size_t zlen = RTStrOffCharOrTerm(pszNext, '.');
243	LogRel(("NAT: resolv.conf: FIXME: ignoring IPv6 zone %.s\n",
244	zlen, zlen, pszNext));
245	pszNext += zlen;
246	}
247
248	rc = rcp_address_trailer(&pszNext, &NetAddr, RTNETADDRTYPE_IPV6);
249	if (RT_FAILURE(rc))
250	{
251	LogRel(("NAT: resolv.conf: garbage at the end of IPv6 address %s\n", tok));
252	continue;
253	}
254
255	LogRel(("NAT: resolv.conf: nameserver %RTnaddr\n", &NetAddr));
256	}
257	} /* IPv6 */
258
259	if (NetAddr.enmType == RTNETADDRTYPE_INVALID)
260	{
261	LogRel(("NAT: resolv.conf: bad nameserver address %s\n", tok));
262	continue;
263	}
264
265
266	tok = getToken(NULL, &s);
267	if (tok != NULL)
268	LogRel(("NAT: resolv.conf: ignoring unexpected trailer on the nameserver line\n"));
269
270	if ((flags & RCPSF_IGNORE_IPV6) && NetAddr.enmType == RTNETADDRTYPE_IPV6)
271	{
272	Log2(("NAT: resolv.conf: IPv6 address ignored\n"));
273	continue;
274	}
275
276	/* seems ok, save it */
277	{
278	i = state->rcps_num_nameserver;
279
280	state->rcps_nameserver[i] = NetAddr;
281
282	/* XXX: TODO: don't save strings unless asked to */
283	Log2(("NAT: resolv.conf: saving address @%td,+%zu\n",
284	pszAddrBuf - state->rcps_nameserver_str_buffer, cbAddrBuf));
285	state->rcps_str_nameserver[i] = pszAddrBuf;
286	rc = RTStrCopyP(&pszAddrBuf, &cbAddrBuf, pszAddr);
287	if (RT_SUCCESS(rc))
288	{
289	++pszAddrBuf; /* skip '\0' */
290	if (cbAddrBuf > 0) /* on overflow we get 1 (for the '\0'), but be defensive */
291	--cbAddrBuf;
292	++state->rcps_num_nameserver;
293	}
294	else
295	{
296	Log2(("NAT: resolv.conf: ... truncated\n"));
297	}
298	}
299
300	continue;
301	}
302
303
304	#ifdef RCP_ACCEPT_PORT /* OS X extention */
305	/*
306	* PORT
307	*/
308	if (RTStrCmp(tok, "port") == 0)
309	{
310	uint16_t port;
311
312	if (default_port != RTNETADDR_PORT_NA)
313	{
314	LogRel(("NAT: resolv.conf: ignoring multiple port lines\n"));
315	continue;
316	}
317
318	tok = getToken(NULL, &s);
319	if (tok == NULL)
320	{
321	LogRel(("NAT: resolv.conf: port line without value\n"));
322	continue;
323	}
324
325	rc = RTStrToUInt16Full(tok, 10, &port);
326	if (RT_SUCCESS(rc))
327	{
328	if (port != 0)
329	default_port = port;
330	else
331	LogRel(("NAT: resolv.conf: port 0 is invalid\n"));
332	}
333
334	continue;
335	}
336	#endif
337
338
339	/*
340	* DOMAIN
341	*/
342	if (RTStrCmp(tok, "domain") == 0)
343	{
344	if (state->rcps_domain != NULL)
345	{
346	LogRel(("NAT: resolv.conf: ignoring multiple domain lines\n"));
347	continue;
348	}
349
350	tok = getToken(NULL, &s);
351	if (tok == NULL)
352	{
353	LogRel(("NAT: resolv.conf: domain line without value\n"));
354	continue;
355	}
356
357	rc = RTStrCopy(state->rcps_domain_buffer, sizeof(state->rcps_domain_buffer), tok);
358	if (RT_SUCCESS(rc))
359	{
360	state->rcps_domain = state->rcps_domain_buffer;
361	}
362	else
363	{
364	LogRel(("NAT: resolv.conf: domain name too long\n"));
365	RT_ZERO(state->rcps_domain_buffer);
366	}
367
368	continue;
369	}
370
371
372	/*
373	* SEARCH
374	*/
375	if (RTStrCmp(tok, "search") == 0)
376	{
377	while ((tok = getToken(NULL, &s)) && tok != NULL)
378	{
379	i = state->rcps_num_searchlist;
380	if (RT_UNLIKELY(i >= RCPS_MAX_SEARCHLIST))
381	{
382	LogRel(("NAT: resolv.conf: too many search domains, ignoring %s\n", tok));
383	continue;
384	}
385
386	Log2(("NAT: resolv.conf: saving search %s @%td,+%zu\n",
387	tok, pszSearchBuf - state->rcps_searchlist_buffer, cbSearchBuf));
388	state->rcps_searchlist[i] = pszSearchBuf;
389	rc = RTStrCopyP(&pszSearchBuf, &cbSearchBuf, tok);
390	if (RT_SUCCESS(rc))
391	{
392	++pszSearchBuf; /* skip '\0' */
393	if (cbSearchBuf > 0) /* on overflow we get 1 (for the '\0'), but be defensive */
394	--cbSearchBuf;
395	++state->rcps_num_searchlist;
396	}
397	else
398	{
399	LogRel(("NAT: resolv.conf: no buffer space, ignoring search domain %s\n", tok));
400	pszSearchBuf = state->rcps_searchlist[i];
401	cbSearchBuf = sizeof(state->rcps_searchlist_buffer)
402	- (pszSearchBuf - state->rcps_searchlist_buffer);
403	Log2(("NAT: resolv.conf: backtracking to @%td,+%zu\n",
404	pszSearchBuf - state->rcps_searchlist_buffer, cbSearchBuf));
405	}
406	}
407
408	continue;
409	}
410
411
412	LogRel(("NAT: resolv.conf: ignoring \"%s %s\"\n", tok, s));
413	}
414
415	if (filename != NULL)
416	RTStrmClose(stream);
417
418	if (RT_FAILURE(rc))
419	return rc;
420
421
422	/* XXX: I don't like that OS X would return a different result here */
423	#ifdef RCP_ACCEPT_PORT /* OS X extention */
424	if (default_port == RTNETADDR_PORT_NA)
425	default_port = 53;
426
427	for (i = 0; i < state->rcps_num_nameserver; ++i)
428	{
429	RTNETADDR *addr = &state->rcps_nameserver[i];
430	if (addr->uPort == RTNETADDR_PORT_NA \|\| addr->uPort == 0)
431	addr->uPort = (uint16_t)default_port;
432	}
433	#endif
434
435	if ( state->rcps_domain == NULL
436	&& state->rcps_num_searchlist > 0)
437	{
438	state->rcps_domain = state->rcps_searchlist[0];
439	}
440
441	return VINF_SUCCESS;
442	}
443
444
445	static int
446	rcp_address_trailer(char **ppszNext, PRTNETADDR pNetAddr, RTNETADDRTYPE enmType)
447	{
448	char pszNext = ppszNext;
449	int rc = VINF_SUCCESS;
450
451	if (*pszNext == '\0')
452	{
453	pNetAddr->enmType = enmType;
454	rc = VINF_SUCCESS;
455	}
456	#ifdef RCP_ACCEPT_PORT /* OS X extention */
457	else if (*pszNext == '.')
458	{
459	uint16_t port;
460
461	rc = RTStrToUInt16Ex(++pszNext, NULL, 10, &port);
462	if (RT_SUCCESS(rc))
463	{
464	pNetAddr->enmType = enmType;
465	pNetAddr->uPort = port;
466	}
467	}
468	#endif
469	else
470	{
471	rc = VERR_TRAILING_CHARS;
472	}
473
474	return rc;
475	}
476
477
478	static char getToken(char psz, char **ppszSavePtr)
479	{
480	char *pszToken;
481
482	AssertPtrReturn(ppszSavePtr, NULL);
483
484	if (psz == NULL)
485	{
486	psz = *ppszSavePtr;
487	if (psz == NULL)
488	return NULL;
489	}
490
491	while (psz == ' ' \|\| psz == '\t')
492	++psz;
493
494	if (*psz == '\0')
495	{
496	*ppszSavePtr = NULL;
497	return NULL;
498	}
499
500	pszToken = psz;
501	while (psz && psz != ' ' && *psz != '\t')
502	++psz;
503
504	if (*psz == '\0')
505	psz = NULL;
506	else
507	*psz++ = '\0';
508
509	*ppszSavePtr = psz;
510	return pszToken;
511	}

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source: vbox/trunk/src/VBox/Devices/Network/slirp/resolv_conf_parser.c@ 91942

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