resolv_conf_parser.c@ 63913

Last change on this file since 63913 was 63913, checked in by vboxsync, 8 years ago
NAT: don't stop parsing if we are out of buffer space for search domains. LogRel search domains we've dropped b/c we didn't have buffer space for them.
Property svn:eol-style set to `native` Property svn:keywords set to `Author Date Id Revision`
File size: 13.2 KB

Line
1	/* $Id: resolv_conf_parser.c 63913 2016-09-20 12:31:51Z 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	#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	tok = getToken(buf, &s);
161
162	/* no more tokens or a comment */
163	# define NO_VALUE(tok) (tok == NULL \|\| tok[0] == '#' \|\| tok[0] == ';')
164
165	if (NO_VALUE(tok))
166	continue;
167
168
169	/*
170	* NAMESERVER
171	*/
172	if (RTStrCmp(tok, "nameserver") == 0)
173	{
174	RTNETADDR NetAddr;
175	const char *pszAddr;
176	char *pszNext;
177
178	if (RT_UNLIKELY(state->rcps_num_nameserver >= RCPS_MAX_NAMESERVERS))
179	{
180	LogRel(("NAT: resolv.conf: too many nameserver lines, ignoring %s\n", s));
181	continue;
182	}
183
184	/* XXX: TODO: don't save strings unless asked to */
185	if (RT_UNLIKELY(cbAddrBuf == 0))
186	{
187	LogRel(("NAT: resolv.conf: no buffer space, ignoring %s\n", s));
188	continue;
189	}
190
191
192	/*
193	* parse next token as an IP address
194	*/
195	tok = getToken(NULL, &s);
196	if (NO_VALUE(tok))
197	{
198	LogRel(("NAT: resolv.conf: nameserver line without value\n"));
199	continue;
200	}
201
202	pszAddr = tok;
203	RT_ZERO(NetAddr);
204	NetAddr.uPort = RTNETADDR_PORT_NA;
205
206	/* if (NetAddr.enmType == RTNETADDRTYPE_INVALID) */
207	{
208	rc = RTNetStrToIPv4AddrEx(tok, &NetAddr.uAddr.IPv4, &pszNext);
209	if (RT_SUCCESS(rc))
210	{
211	rc = rcp_address_trailer(&pszNext, &NetAddr, RTNETADDRTYPE_IPV4);
212	if (RT_FAILURE(rc))
213	{
214	LogRel(("NAT: resolv.conf: garbage at the end of IPv4 address %s\n", tok));
215	continue;
216	}
217
218	LogRel(("NAT: resolv.conf: nameserver %RTnaddr\n", &NetAddr));
219	}
220	} /* IPv4 */
221
222	if (NetAddr.enmType == RTNETADDRTYPE_INVALID)
223	{
224	rc = RTNetStrToIPv6AddrEx(tok, &NetAddr.uAddr.IPv6, &pszNext);
225	if (RT_SUCCESS(rc))
226	{
227	if (pszNext == '%') / XXX: TODO: IPv6 zones */
228	{
229	size_t zlen = RTStrOffCharOrTerm(pszNext, '.');
230	LogRel(("NAT: resolv.conf: FIXME: ignoring IPv6 zone %.s\n",
231	zlen, zlen, pszNext));
232	pszNext += zlen;
233	}
234
235	rc = rcp_address_trailer(&pszNext, &NetAddr, RTNETADDRTYPE_IPV6);
236	if (RT_FAILURE(rc))
237	{
238	LogRel(("NAT: resolv.conf: garbage at the end of IPv6 address %s\n", tok));
239	continue;
240	}
241
242	LogRel(("NAT: resolv.conf: nameserver %RTnaddr\n", &NetAddr));
243	}
244	} /* IPv6 */
245
246	if (NetAddr.enmType == RTNETADDRTYPE_INVALID)
247	{
248	LogRel(("NAT: resolv.conf: bad nameserver address %s\n", tok));
249	continue;
250	}
251
252
253	tok = getToken(NULL, &s);
254	if (!NO_VALUE(tok))
255	LogRel(("NAT: resolv.conf: ignoring unexpected trailer on the nameserver line\n"));
256
257	if ((flags & RCPSF_IGNORE_IPV6) && NetAddr.enmType == RTNETADDRTYPE_IPV6)
258	{
259	Log2(("NAT: resolv.conf: IPv6 address ignored\n"));
260	continue;
261	}
262
263	/* seems ok, save it */
264	{
265	i = state->rcps_num_nameserver;
266
267	state->rcps_nameserver[i] = NetAddr;
268
269	/* XXX: TODO: don't save strings unless asked to */
270	Log2(("NAT: resolv.conf: saving address @%td,+%zu\n",
271	pszAddrBuf - state->rcps_nameserver_str_buffer, cbAddrBuf));
272	state->rcps_str_nameserver[i] = pszAddrBuf;
273	rc = RTStrCopyP(&pszAddrBuf, &cbAddrBuf, pszAddr);
274	if (RT_SUCCESS(rc))
275	{
276	++pszAddrBuf; /* skip '\0' */
277	if (cbAddrBuf > 0) /* on overflow we get 1 (for the '\0'), but be defensive */
278	--cbAddrBuf;
279	++state->rcps_num_nameserver;
280	}
281	else
282	{
283	Log2(("NAT: resolv.conf: ... truncated\n"));
284	}
285	}
286
287	continue;
288	}
289
290
291	#ifdef RCP_ACCEPT_PORT /* OS X extention */
292	/*
293	* PORT
294	*/
295	if (RTStrCmp(tok, "port") == 0)
296	{
297	uint16_t port;
298
299	if (default_port != RTNETADDR_PORT_NA)
300	{
301	LogRel(("NAT: resolv.conf: ignoring multiple port lines\n"));
302	continue;
303	}
304
305	tok = getToken(NULL, &s);
306	if (NO_VALUE(tok))
307	{
308	LogRel(("NAT: resolv.conf: port line without value\n"));
309	continue;
310	}
311
312	rc = RTStrToUInt16Full(tok, 10, &port);
313	if (RT_SUCCESS(rc))
314	{
315	if (port != 0)
316	default_port = port;
317	else
318	LogRel(("NAT: resolv.conf: port 0 is invalid\n"));
319	}
320
321	continue;
322	}
323	#endif
324
325
326	/*
327	* DOMAIN
328	*/
329	if (RTStrCmp(tok, "domain") == 0)
330	{
331	if (state->rcps_domain != NULL)
332	{
333	LogRel(("NAT: resolv.conf: ignoring multiple domain lines\n"));
334	continue;
335	}
336
337	tok = getToken(NULL, &s);
338	if (NO_VALUE(tok))
339	{
340	LogRel(("NAT: resolv.conf: domain line without value\n"));
341	continue;
342	}
343
344	rc = RTStrCopy(state->rcps_domain_buffer, sizeof(state->rcps_domain_buffer), tok);
345	if (RT_SUCCESS(rc))
346	{
347	state->rcps_domain = state->rcps_domain_buffer;
348	}
349	else
350	{
351	LogRel(("NAT: resolv.conf: domain name too long\n"));
352	RT_ZERO(state->rcps_domain_buffer);
353	}
354
355	continue;
356	}
357
358
359	/*
360	* SEARCH
361	*/
362	if (RTStrCmp(tok, "search") == 0)
363	{
364	while ((tok = getToken(NULL, &s)) && !NO_VALUE(tok))
365	{
366	i = state->rcps_num_searchlist;
367	if (RT_UNLIKELY(i >= RCPS_MAX_SEARCHLIST))
368	{
369	LogRel(("NAT: resolv.conf: too many search domains, ignoring %s\n", tok));
370	continue;
371	}
372
373	Log2(("NAT: resolv.conf: saving search %s @%td,+%zu\n",
374	tok, pszSearchBuf - state->rcps_searchlist_buffer, cbSearchBuf));
375	state->rcps_searchlist[i] = pszSearchBuf;
376	rc = RTStrCopyP(&pszSearchBuf, &cbSearchBuf, tok);
377	if (RT_SUCCESS(rc))
378	{
379	++pszSearchBuf; /* skip '\0' */
380	if (cbSearchBuf > 0) /* on overflow we get 1 (for the '\0'), but be defensive */
381	--cbSearchBuf;
382	++state->rcps_num_searchlist;
383	}
384	else
385	{
386	LogRel(("NAT: resolv.conf: no buffer space, ignoring search domain %s\n", tok));
387	pszSearchBuf = state->rcps_searchlist[i];
388	cbSearchBuf = sizeof(state->rcps_searchlist_buffer)
389	- (pszSearchBuf - state->rcps_searchlist_buffer);
390	Log2(("NAT: resolv.conf: backtracking to @%td,+%zu\n",
391	pszSearchBuf - state->rcps_searchlist_buffer, cbSearchBuf));
392	}
393	}
394
395	continue;
396	}
397
398
399	LogRel(("NAT: resolv.conf: ignoring \"%s %s\"\n", tok, s));
400	}
401
402	if (filename != NULL)
403	RTStrmClose(stream);
404
405	if (RT_FAILURE(rc))
406	return rc;
407
408
409	/* XXX: I don't like that OS X would return a different result here */
410	#ifdef RCP_ACCEPT_PORT /* OS X extention */
411	if (default_port == RTNETADDR_PORT_NA)
412	default_port = 53;
413
414	for (i = 0; i < state->rcps_num_nameserver; ++i)
415	{
416	RTNETADDR *addr = &state->rcps_nameserver[i];
417	if (addr->uPort == RTNETADDR_PORT_NA \|\| addr->uPort == 0)
418	addr->uPort = (uint16_t)default_port;
419	}
420	#endif
421
422	if ( state->rcps_domain == NULL
423	&& state->rcps_num_searchlist > 0)
424	{
425	state->rcps_domain = state->rcps_searchlist[0];
426	}
427
428	return VINF_SUCCESS;
429	}
430
431
432	static int
433	rcp_address_trailer(char **ppszNext, PRTNETADDR pNetAddr, RTNETADDRTYPE enmType)
434	{
435	char pszNext = ppszNext;
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	uint16_t port;
447
448	rc = RTStrToUInt16Ex(++pszNext, NULL, 10, &port);
449	if (RT_SUCCESS(rc))
450	{
451	pNetAddr->enmType = enmType;
452	pNetAddr->uPort = port;
453	}
454	}
455	#endif
456	else
457	{
458	rc = VERR_TRAILING_CHARS;
459	}
460
461	return rc;
462	}
463
464
465	static char getToken(char psz, char **ppszSavePtr)
466	{
467	char *pszToken;
468
469	AssertPtrReturn(ppszSavePtr, NULL);
470
471	if (psz == NULL)
472	{
473	psz = *ppszSavePtr;
474	if (psz == NULL)
475	return NULL;
476	}
477
478	while (psz == ' ' \|\| psz == '\t')
479	++psz;
480
481	if (*psz == '\0')
482	{
483	*ppszSavePtr = NULL;
484	return NULL;
485	}
486
487	pszToken = psz;
488	while (psz && psz != ' ' && *psz != '\t')
489	++psz;
490
491	if (*psz == '\0')
492	psz = NULL;
493	else
494	*psz++ = '\0';
495
496	*ppszSavePtr = psz;
497	return pszToken;
498	}

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

source: vbox/trunk/src/VBox/Devices/Network/slirp/resolv_conf_parser.c@ 63913

Download in other formats: