resolv_conf_parser.c@ 60960

Last change on this file since 60960 was 60960, checked in by vboxsync, 9 years ago
NAT: rewrite resolv.conf parser. The old code tried to be fancy, but somehow manged to miss the fact that resolv.conf is line-oriented.
Property svn:eol-style set to `native` Property svn:keywords set to `Author Date Id Revision`
File size: 13.1 KB

Line
1	/* $Id: resolv_conf_parser.c 60960 2016-05-12 15:24:18Z vboxsync $ */
2	/** @file
3	* resolv_conf_parser.c - parser of resolv.conf resolver(5)
4	*/
5
6	/*
7	* Copyright (C) 2016 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	uint32_t default_port = RTNETADDR_PORT_NA;
114	unsigned i;
115	int rc;
116
117	AssertPtrReturn(state, VERR_INVALID_PARAMETER);
118	flags = state->rcps_flags;
119
120	RT_ZERO(*state);
121	state->rcps_flags = flags;
122
123	if (RT_UNLIKELY(filename == NULL))
124	{
125	#ifdef RCP_STANDALONE
126	stream = g_pStdIn; /* for testing/debugging */
127	#else
128	return VERR_INVALID_PARAMETER;
129	#endif
130	}
131	else
132	{
133	rc = RTStrmOpen(filename, "r", &stream);
134	if (RT_FAILURE(rc))
135	return rc;
136	}
137
138
139	pszAddrBuf = state->rcps_nameserver_str_buffer;
140	cbAddrBuf = sizeof(state->rcps_nameserver_str_buffer);
141
142	pszSearchBuf = state->rcps_searchlist_buffer;
143	cbSearchBuf = sizeof(state->rcps_searchlist_buffer);
144
145	for (;;)
146	{
147	char s, tok;
148
149	rc = RTStrmGetLine(stream, buf, sizeof(buf));
150	if (RT_FAILURE(rc))
151	{
152	if (rc == VERR_EOF)
153	rc = VINF_SUCCESS;
154	break;
155	}
156
157
158	tok = getToken(buf, &s);
159
160	/* no more tokens or a comment */
161	# define NO_VALUE(tok) (tok == NULL \|\| tok[0] == '#' \|\| tok[0] == ';')
162
163	if (NO_VALUE(tok))
164	continue;
165
166
167	/*
168	* NAMESERVER
169	*/
170	if (RTStrCmp(tok, "nameserver") == 0)
171	{
172	RTNETADDR NetAddr;
173	const char *pszAddr;
174	char *pszNext;
175
176	if (RT_UNLIKELY(state->rcps_num_nameserver >= RCPS_MAX_NAMESERVERS))
177	{
178	LogRel(("NAT: resolv.conf: too many nameserver lines, ignoring %s\n", s));
179	continue;
180	}
181
182	/* XXX: TODO: don't save strings unless asked to */
183	if (RT_UNLIKELY(cbAddrBuf == 0))
184	{
185	LogRel(("NAT: resolv.conf: no buffer space, ignoring %s\n", s));
186	continue;
187	}
188
189
190	/*
191	* parse next token as an IP address
192	*/
193	tok = getToken(NULL, &s);
194	if (NO_VALUE(tok))
195	{
196	LogRel(("NAT: resolv.conf: nameserver line without value\n"));
197	continue;
198	}
199
200	pszAddr = tok;
201	RT_ZERO(NetAddr);
202	NetAddr.uPort = RTNETADDR_PORT_NA;
203
204	/* if (NetAddr.enmType == RTNETADDRTYPE_INVALID) */
205	{
206	rc = RTNetStrToIPv4AddrEx(tok, &NetAddr.uAddr.IPv4, &pszNext);
207	if (RT_SUCCESS(rc))
208	{
209	rc = rcp_address_trailer(&pszNext, &NetAddr, RTNETADDRTYPE_IPV4);
210	if (RT_FAILURE(rc))
211	{
212	LogRel(("NAT: resolv.conf: garbage at the end of IPv4 address %s\n", tok));
213	continue;
214	}
215
216	LogRel(("NAT: resolv.conf: nameserver %RTnaddr\n", &NetAddr));
217	}
218	} /* IPv4 */
219
220	if (NetAddr.enmType == RTNETADDRTYPE_INVALID)
221	{
222	rc = RTNetStrToIPv6AddrEx(tok, &NetAddr.uAddr.IPv6, &pszNext);
223	if (RT_SUCCESS(rc))
224	{
225	if (pszNext == '%') / XXX: TODO: IPv6 zones */
226	{
227	size_t zlen = RTStrOffCharOrTerm(pszNext, '.');
228	LogRel(("NAT: resolv.conf: FIXME: ignoring IPv6 zone %.s\n",
229	zlen, zlen, pszNext));
230	pszNext += zlen;
231	}
232
233	rc = rcp_address_trailer(&pszNext, &NetAddr, RTNETADDRTYPE_IPV6);
234	if (RT_FAILURE(rc))
235	{
236	LogRel(("NAT: resolv.conf: garbage at the end of IPv6 address %s\n", tok));
237	continue;
238	}
239
240	LogRel(("NAT: resolv.conf: nameserver %RTnaddr\n", &NetAddr));
241	}
242	} /* IPv6 */
243
244	if (NetAddr.enmType == RTNETADDRTYPE_INVALID)
245	{
246	LogRel(("NAT: resolv.conf: bad nameserver address %s\n", tok));
247	continue;
248	}
249
250
251	tok = getToken(NULL, &s);
252	if (!NO_VALUE(tok))
253	LogRel(("NAT: resolv.conf: ignoring unexpected trailer on the nameserver line\n"));
254
255	if ((flags & RCPSF_IGNORE_IPV6) && NetAddr.enmType == RTNETADDRTYPE_IPV6)
256	{
257	Log2(("NAT: resolv.conf: IPv6 address ignored\n"));
258	continue;
259	}
260
261	/* seems ok, save it */
262	{
263	i = state->rcps_num_nameserver;
264
265	state->rcps_nameserver[i] = NetAddr;
266
267	/* XXX: TODO: don't save strings unless asked to */
268	Log2(("NAT: resolv.conf: saving address @%td,+%zu\n",
269	pszAddrBuf - state->rcps_nameserver_str_buffer, cbAddrBuf));
270	state->rcps_str_nameserver[i] = pszAddrBuf;
271	rc = RTStrCopyP(&pszAddrBuf, &cbAddrBuf, pszAddr);
272	if (RT_SUCCESS(rc))
273	{
274	++pszAddrBuf; /* skip '\0' */
275	if (cbAddrBuf > 0) /* on overflow we get 1 (for the '\0'), but be defensive */
276	--cbAddrBuf;
277	++state->rcps_num_nameserver;
278	}
279	else
280	{
281	Log2(("NAT: resolv.conf: ... truncated\n"));
282	}
283	}
284
285	continue;
286	}
287
288
289	#ifdef RCP_ACCEPT_PORT /* OS X extention */
290	/*
291	* PORT
292	*/
293	if (RTStrCmp(tok, "port") == 0)
294	{
295	uint16_t port;
296
297	if (default_port != RTNETADDR_PORT_NA)
298	{
299	LogRel(("NAT: resolv.conf: ignoring multiple port lines\n"));
300	continue;
301	}
302
303	tok = getToken(NULL, &s);
304	if (NO_VALUE(tok))
305	{
306	LogRel(("NAT: resolv.conf: port line without value\n"));
307	continue;
308	}
309
310	rc = RTStrToUInt16Full(tok, 10, &port);
311	if (RT_SUCCESS(rc))
312	{
313	if (port != 0)
314	default_port = port;
315	else
316	LogRel(("NAT: resolv.conf: port 0 is invalid\n"));
317	}
318
319	continue;
320	}
321	#endif
322
323
324	/*
325	* DOMAIN
326	*/
327	if (RTStrCmp(tok, "domain") == 0)
328	{
329	if (state->rcps_domain != NULL)
330	{
331	LogRel(("NAT: resolv.conf: ignoring multiple domain lines\n"));
332	continue;
333	}
334
335	tok = getToken(NULL, &s);
336	if (NO_VALUE(tok))
337	{
338	LogRel(("NAT: resolv.conf: domain line without value\n"));
339	continue;
340	}
341
342	rc = RTStrCopy(state->rcps_domain_buffer, sizeof(state->rcps_domain_buffer), tok);
343	if (RT_SUCCESS(rc))
344	{
345	state->rcps_domain = state->rcps_domain_buffer;
346	}
347	else
348	{
349	LogRel(("NAT: resolv.conf: domain name too long\n"));
350	RT_ZERO(state->rcps_domain_buffer);
351	}
352
353	continue;
354	}
355
356
357	/*
358	* SEARCH
359	*/
360	if (RTStrCmp(tok, "search") == 0)
361	{
362	if (cbSearchBuf == 0)
363	{
364	LogRel(("NAT: resolv.conf: no buffer space, ignoring search list %s\n", s));
365	break;
366	}
367
368	while ((tok = getToken(NULL, &s)) && !NO_VALUE(tok))
369	{
370	i = state->rcps_num_searchlist;
371
372	Log2(("NAT: resolv.conf: saving search @%td,+%zu\n",
373	pszSearchBuf - state->rcps_searchlist_buffer, cbSearchBuf));
374	state->rcps_searchlist[i] = pszSearchBuf;
375	rc = RTStrCopyP(&pszSearchBuf, &cbSearchBuf, tok);
376	if (RT_SUCCESS(rc))
377	{
378	++pszSearchBuf; /* skip '\0' */
379	if (cbSearchBuf > 0) /* on overflow we get 1 (for the '\0'), but be defensive */
380	--cbSearchBuf;
381	++state->rcps_num_searchlist;
382	}
383	else
384	{
385	Log2(("NAT: resolv.conf: truncated: %s\n", tok));
386	pszSearchBuf = state->rcps_searchlist[i];
387	cbSearchBuf = sizeof(state->rcps_searchlist_buffer)
388	- (pszSearchBuf - state->rcps_searchlist_buffer);
389	Log2(("NAT: resolv.conf: backtracking to @%td,+%zu\n",
390	pszSearchBuf - state->rcps_searchlist_buffer, cbSearchBuf));
391	}
392	}
393
394	continue;
395	}
396
397
398	LogRel(("NAT: resolv.conf: ignoring \"%s %s\"\n", tok, s));
399	}
400
401	if (filename != NULL)
402	RTStrmClose(stream);
403
404	if (RT_FAILURE(rc))
405	return rc;
406
407
408	/* XXX: I don't like that OS X would return a different result here */
409	#ifdef RCP_ACCEPT_PORT /* OS X extention */
410	if (default_port == RTNETADDR_PORT_NA)
411	default_port = 53;
412
413	for (i = 0; i < state->rcps_num_nameserver; ++i)
414	{
415	RTNETADDR *addr = &state->rcps_nameserver[i];
416	if (addr->uPort == RTNETADDR_PORT_NA \|\| addr->uPort == 0)
417	addr->uPort = (uint16_t)default_port;
418	}
419	#endif
420
421	if ( state->rcps_domain == NULL
422	&& state->rcps_num_searchlist > 0)
423	{
424	state->rcps_domain = state->rcps_searchlist[0];
425	}
426
427	return VINF_SUCCESS;
428	}
429
430
431	static int
432	rcp_address_trailer(char **ppszNext, PRTNETADDR pNetAddr, RTNETADDRTYPE enmType)
433	{
434	char pszNext = ppszNext;
435	uint16_t port;
436	int rc = VINF_SUCCESS;
437
438	if (*pszNext == '\0')
439	{
440	pNetAddr->enmType = enmType;
441	rc = VINF_SUCCESS;
442	}
443	#ifdef RCP_ACCEPT_PORT /* OS X extention */
444	else if (*pszNext == '.')
445	{
446	rc = RTStrToUInt16Ex(++pszNext, NULL, 10, &port);
447	if (RT_SUCCESS(rc))
448	{
449	pNetAddr->enmType = enmType;
450	pNetAddr->uPort = port;
451	}
452	}
453	#endif
454	else
455	{
456	rc = VERR_TRAILING_CHARS;
457	}
458
459	return rc;
460	}
461
462
463	static char getToken(char psz, char **ppszSavePtr)
464	{
465	char *pszToken;
466
467	AssertPtrReturn(ppszSavePtr, NULL);
468
469	if (psz == NULL)
470	{
471	psz = *ppszSavePtr;
472	if (psz == NULL)
473	return NULL;
474	}
475
476	while (psz && psz == ' ' && *psz == '\t')
477	++psz;
478
479	if (*psz == '\0')
480	{
481	*ppszSavePtr = NULL;
482	return NULL;
483	}
484
485	pszToken = psz;
486	while (psz && psz != ' ' && *psz != '\t')
487	++psz;
488
489	if (*psz == '\0')
490	psz = NULL;
491	else
492	*psz++ = '\0';
493
494	*ppszSavePtr = psz;
495	return pszToken;
496	}

Note: See TracBrowser for help on using the repository browser.

source: vbox/trunk/src/VBox/Devices/Network/slirp/resolv_conf_parser.c@ 60960

Download in other formats: