[ViewVC] Diff of: cvs/gvpe/src/vpn

Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.29 by pcg, Sun Mar 13 12:40:20 2005 UTC vs.
Revision 1.53 by root, Tue Oct 18 10:54:17 2011 UTC

…		…
1	/*	1	/*
2	vpn_dns.C -- handle the dns tunnel part of the protocol.	2	vpn_dns.C -- handle the dns tunnel part of the protocol.
3	Copyright (C) 2003-2005 Marc Lehmann <gvpe@schmorp.de>	3	Copyright (C) 2003-2011 Marc Lehmann <gvpe@schmorp.de>
4		4
5	This file is part of GVPE.	5	This file is part of GVPE.
6		6
7	GVPE is free software; you can redistribute it and/or modify	7	GVPE is free software; you can redistribute it and/or modify it
8	it under the terms of the GNU General Public License as published by	8	under the terms of the GNU General Public License as published by the
9	the Free Software Foundation; either version 2 of the License, or	9	Free Software Foundation; either version 3 of the License, or (at your
10	(at your option) any later version.	10	option) any later version.
11		11
12	This program is distributed in the hope that it will be useful,	12	This program is distributed in the hope that it will be useful, but
13	but WITHOUT ANY WARRANTY; without even the implied warranty of	13	WITHOUT ANY WARRANTY; without even the implied warranty of
14	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the	14	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
15	GNU General Public License for more details.	15	Public License for more details.
16		16
17	You should have received a copy of the GNU General Public License	17	You should have received a copy of the GNU General Public License along
18	along with gvpe; if not, write to the Free Software	18	with this program; if not, see <http://www.gnu.org/licenses/>.
19	Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA	19
		20	Additional permission under GNU GPL version 3 section 7
		21
		22	If you modify this Program, or any covered work, by linking or
		23	combining it with the OpenSSL project's OpenSSL library (or a modified
		24	version of that library), containing parts covered by the terms of the
		25	OpenSSL or SSLeay licenses, the licensors of this Program grant you
		26	additional permission to convey the resulting work. Corresponding
		27	Source for a non-source form of such a combination shall include the
		28	source code for the parts of OpenSSL used as well as that of the
		29	covered work.
20	*/	30	*/
		31
		32	// TODO: EDNS0 option to increase dns mtu?
		33	// TODO: re-write dns packet parsing/creation using a safe mem-buffer
		34	// to ensure no buffer overflows or similar problems.
21		35
22	#include "config.h"	36	#include "config.h"
23		37
24	#if ENABLE_DNS	38	#if ENABLE_DNS
25		39
38	#include <unistd.h>	52	#include <unistd.h>
39	#include <fcntl.h>	53	#include <fcntl.h>
40		54
41	#include <map>	55	#include <map>
42		56
		57	#include <cstdio> /* bug in libgmp: gmp.h relies on cstdio being included */
43	#include <gmp.h>	58	#include <gmp.h>
44		59
45	#include "netcompat.h"	60	#include "netcompat.h"
46		61
47	#include "vpn.h"	62	#include "vpn.h"
48		63
49	#define MIN_POLL_INTERVAL .02 // how often to poll minimally when the server has data	64	#define MIN_POLL_INTERVAL 0.025 // poll at most this often when no data received
50	#define MAX_POLL_INTERVAL 6. // how often to poll minimally when the server has no data	65	#define MAX_POLL_INTERVAL 1. // how often to poll minimally when the server has no data
51	#define ACTIVITY_INTERVAL 5.
52		66
53	#define INITIAL_TIMEOUT 0.1 // retry timeouts	67	#define INITIAL_TIMEOUT 0.1 // retry timeouts
54	#define INITIAL_SYN_TIMEOUT 10. // retry timeout for initial syn	68	#define INITIAL_SYN_TIMEOUT 2. // retry timeout for initial syn
55		69
56	#define MIN_SEND_INTERVAL 0.01 // wait at least this time between sending requests
57	#define MAX_SEND_INTERVAL 2. // optimistic?	70	#define MAX_SEND_INTERVAL 5. // optimistic?
58		71
59	#define LATENCY_FACTOR 0.5 // RTT * LATENCY_FACTOR == sending rate
60	#define MAX_OUTSTANDING 100 // max. outstanding requests
61	#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog	72	#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog
62	#define MAX_BACKLOG (100*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE	73	#define MAX_BACKLOG (64*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE
63		74
64	#define MAX_DOMAIN_SIZE 240 // 255 is legal limit, but bind doesn't compress well	75	#define MAX_DOMAIN_SIZE 235 // 255 is legal limit, but bind doesn't compress well
65	// 240 leaves about 4 bytes of server reply data	76	// 240 leaves about 4 bytes of server reply data
66	// every two request bytes less give room for one reply byte	77	// every request byte less give room for two reply bytes
67		78
68	#define SEQNO_MASK 0x3fff	79	#define SEQNO_MASK 0x3fff
69	#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )	80	#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )
70		81
71	#define MAX_LBL_SIZE 63	82	#define MAX_LBL_SIZE 63
72	#define MAX_PKT_SIZE 512	83	#define MAX_PKT_SIZE 512
73		84
74	#define RR_TYPE_A 1	85	#define RR_TYPE_A 1
75	#define RR_TYPE_NULL 10	86	#define RR_TYPE_NULL 10
76	#define RR_TYPE_TXT 16	87	#define RR_TYPE_TXT 16
		88	#define RR_TYPE_AAAA 28
77	#define RR_TYPE_ANY 255	89	#define RR_TYPE_ANY 255
78		90
79	#define RR_CLASS_IN 1	91	#define RR_CLASS_IN 1
80		92
81	#define CMD_IP_1 207	93	#define CMD_IP_1 207
82	#define CMD_IP_2 46	94	#define CMD_IP_2 46
83	#define CMD_IP_3 236	95	#define CMD_IP_3 236
84	#define CMD_IP_RST 29	96
85	#define CMD_IP_SYN 113	97	#define CMD_IP_RST 29 // some error, reset and retry
86	#define CMD_IP_REJ 32	98	#define CMD_IP_REJ 32 // do not want you
		99	#define CMD_IP_SYN 113 // connection established
		100	#define CMD_IP_CSE 213 // connection established, but likely case mismatch
		101
		102	static bool
		103	is_uc (char c)
		104	{
		105	return 'A' <= c && c <= 'Z';
		106	}
		107
		108	static bool
		109	is_lc (char c)
		110	{
		111	return 'a' <= c && c <= 'z';
		112	}
87		113
88	// works for cmaps up to 255 (not 256!)	114	// works for cmaps up to 255 (not 256!)
89	struct charmap	115	struct charmap
90	{	116	{
91	enum { INVALID = (u8)255 };	117	enum { INVALID = (u8)255 };
…		…
105	memset (enc, (char) 0, 256);	131	memset (enc, (char) 0, 256);
106	memset (dec, (char)INVALID, 256);	132	memset (dec, (char)INVALID, 256);
107		133
108	for (size = 0; cmap [size]; size++)	134	for (size = 0; cmap [size]; size++)
109	{	135	{
		136	char c = cmap [size];
		137
110	enc [size] = cmap [size];	138	enc [size] = c;
111	dec [(u8)enc [size]] = size;	139	dec [(u8)c] = size;
		140
		141	// allow lowercase/uppercase aliases if possible
		142	if (is_uc (c) && dec [c + ('a' - 'A')] == INVALID) dec [c + ('a' - 'A')] = size;
		143	if (is_lc (c) && dec [c - ('a' - 'A')] == INVALID) dec [c - ('a' - 'A')] = size;
112	}	144	}
113		145
114	assert (size < 256);	146	assert (size < 256);
115	}	147	}
116		148
…		…
123	{	155	{
124	charmap cmap;	156	charmap cmap;
125	unsigned int enc_len [MAX_DEC_LEN];	157	unsigned int enc_len [MAX_DEC_LEN];
126	unsigned int dec_len [MAX_ENC_LEN];	158	unsigned int dec_len [MAX_ENC_LEN];
127		159
128	unsigned int encode_len (unsigned int len);	160	unsigned int encode_len (unsigned int len) const;
129	unsigned int decode_len (unsigned int len);	161	unsigned int decode_len (unsigned int len) const;
130		162
131	unsigned int encode (char dst, u8 src, unsigned int len);	163	unsigned int encode (char dst, u8 src, unsigned int len) const;
132	unsigned int decode (u8 dst, char src, unsigned int len);	164	unsigned int decode (u8 dst, char src, unsigned int len) const;
133		165
134	basecoder (const char *cmap);	166	basecoder (const char *cmap);
135	};	167	};
136		168
137	basecoder::basecoder (const char *cmap)	169	basecoder::basecoder (const char *cmap)
…		…
156	enc_len [len] = n;	188	enc_len [len] = n;
157	dec_len [n] = len;	189	dec_len [n] = len;
158	}	190	}
159	}	191	}
160		192
		193	unsigned int
161	unsigned int basecoder::encode_len (unsigned int len)	194	basecoder::encode_len (unsigned int len) const
162	{	195	{
163	return enc_len [len];	196	return enc_len [len];
164	}	197	}
165		198
		199	unsigned int
166	unsigned int basecoder::decode_len (unsigned int len)	200	basecoder::decode_len (unsigned int len) const
167	{	201	{
168	while (len && !dec_len [len])	202	while (len && !dec_len [len])
169	--len;	203	--len;
170		204
171	return dec_len [len];	205	return dec_len [len];
172	}	206	}
173		207
		208	unsigned int
174	unsigned int basecoder::encode (char dst, u8 src, unsigned int len)	209	basecoder::encode (char dst, u8 src, unsigned int len) const
175	{	210	{
176	if (!len \|\| len > MAX_DEC_LEN)	211	if (!len \|\| len > MAX_DEC_LEN)
177	return 0;	212	return 0;
178		213
179	int elen = encode_len (len);	214	int elen = encode_len (len);
…		…
198	*dst++ = cmap.encode [dst_ [i]];	233	*dst++ = cmap.encode [dst_ [i]];
199		234
200	return elen;	235	return elen;
201	}	236	}
202		237
		238	unsigned int
203	unsigned int basecoder::decode (u8 dst, char src, unsigned int len)	239	basecoder::decode (u8 dst, char src, unsigned int len) const
204	{	240	{
205	if (!len \|\| len > MAX_ENC_LEN)	241	if (!len \|\| len > MAX_ENC_LEN)
206	return 0;	242	return 0;
207		243
208	u8 src_ [MAX_ENC_LEN];	244	u8 src_ [MAX_ENC_LEN];
…		…
257	}	293	}
258	abort ();	294	abort ();
259	}	295	}
260	#endif	296	#endif
261		297
262	//static basecoder cdc64 ("_dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI-");
263	//static basecoder cdc63 ("_dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI");
264	static basecoder cdc62 ("dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI");	298	static basecoder cdc62 ("dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI"); // a-zA-Z0-9
265	//static basecoder cdc36 ("dphzr06qmjkb34tsvl81xaef92wgyo57ucni"); // unused as of yet	299	static basecoder cdc36 ("dPhZr06QmJkB34tSvL81xAeF92wGyO57uCnI"); // a-z0-9 for case-changers
266	static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO");	300	static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyOuCnI"); // a-z
267		301
268	/////////////////////////////////////////////////////////////////////////////	302	/////////////////////////////////////////////////////////////////////////////
269		303
270	#define HDRSIZE 6	304	#define HDRSIZE 5
271		305
		306	inline void
272	inline void encode_header (char *data, int clientid, int seqno, int retry = 0)	307	encode_header (char *data, int clientid, int seqno, int retry = 0)
273	{	308	{
		309	assert (clientid < 256);
		310
274	seqno &= SEQNO_MASK;	311	seqno &= SEQNO_MASK;
275		312
276	u8 hdr[3] = {	313	u8 hdr[3] = {
		314	seqno,
		315	(seqno >> 8) \| (retry << 6),
277	clientid,	316	clientid,
278	(seqno >> 8) \| (retry << 6),
279	seqno,
280	};	317	};
281		318
282	assert (clientid < 256);
283
284	cdc26.encode (data, hdr, 3);	319	cdc36.encode (data, hdr, 3);
285	}	320	}
286		321
		322	inline void
287	inline void decode_header (char *data, int &clientid, int &seqno)	323	decode_header (char *data, int &clientid, int &seqno)
288	{	324	{
289	u8 hdr[3];	325	u8 hdr[3];
290		326
291	cdc26.decode (hdr, data, HDRSIZE);	327	cdc36.decode (hdr, data, HDRSIZE);
292		328
293	clientid = hdr[0];	329	clientid = hdr[2];
294	seqno = ((hdr[1] << 8) \| hdr[2]) & SEQNO_MASK;	330	seqno = ((hdr[1] << 8) \| hdr[0]) & SEQNO_MASK;
295	}	331	}
296		332
297	/////////////////////////////////////////////////////////////////////////////	333	/////////////////////////////////////////////////////////////////////////////
298		334
299	struct byte_stream	335	struct byte_stream
…		…
325	byte_stream::~byte_stream ()	361	byte_stream::~byte_stream ()
326	{	362	{
327	delete data;	363	delete data;
328	}	364	}
329		365
		366	void
330	void byte_stream::remove (int count)	367	byte_stream::remove (int count)
331	{	368	{
332	if (count > fill)	369	if (count > fill)
333	assert (count <= fill);	370	assert (count <= fill);
334		371
335	memmove (data, data + count, fill -= count);	372	memmove (data, data + count, fill -= count);
336	}	373	}
337		374
		375	bool
338	bool byte_stream::put (u8 *data, unsigned int datalen)	376	byte_stream::put (u8 *data, unsigned int datalen)
339	{	377	{
340	if (maxsize - fill < datalen)	378	if (maxsize - fill < datalen)
341	return false;	379	return false;
342		380
343	memcpy (this->data + fill, data, datalen); fill += datalen;	381	memcpy (this->data + fill, data, datalen); fill += datalen;
344		382
345	return true;	383	return true;
346	}	384	}
347		385
		386	bool
348	bool byte_stream::put (vpn_packet *pkt)	387	byte_stream::put (vpn_packet *pkt)
349	{	388	{
350	if (maxsize - fill < pkt->len + 2)	389	if (maxsize - fill < pkt->len + 2)
351	return false;	390	return false;
352		391
353	data [fill++] = pkt->len >> 8;	392	data [fill++] = pkt->len >> 8;
…		…
409		448
410	struct dns_cfg	449	struct dns_cfg
411	{	450	{
412	static int next_uid;	451	static int next_uid;
413		452
414	u8 id1, id2, id3, id4;	453	u8 chksum;
		454	u8 rrtype;
		455	u16 uid; // to make request unique
415		456
416	u8 version;	457	u8 version;
417	u8 flags;	458	u8 flags;
418	u8 rrtype;	459	u16 max_size;
		460
		461	u8 id1, id2, id3, id4;
		462
		463	u16 client;
419	u8 def_ttl;	464	u8 def_ttl;
		465	u8 r0;
420		466
421	u16 client;	467	u8 syn_cdc; // cdc en/decoder for syn (A?) requests
422	u16 uid; // to make request unique	468	u8 hdr_cdc; // cdc en/decoder for regular request headers
		469	u8 req_cdc; // cdc en/decoder for regular (ANY?) request data
		470	u8 rep_cdc; // cdc en/decoder for regular (TXT) replies, 0 == 8 bit encoding
423		471
424	u16 max_size;
425	u8 seq_cdc;
426	u8 req_cdc;
427
428	u8 rep_cdc;
429	u8 r2, r3, r4;	472	u8 r1, r2, r3, r4;
430
431	u8 r5, r6, r7, r8;
432		473
433	void reset (int clientid);	474	void reset (int clientid);
434	bool valid ();	475	bool valid ();
		476	u8 get_chksum ();
435	};	477	};
436		478
437	int dns_cfg::next_uid;	479	int dns_cfg::next_uid;
438		480
		481	void
439	void dns_cfg::reset (int clientid)	482	dns_cfg::reset (int clientid)
440	{	483	{
		484	// this ID must result in some mixed-case characters in cdc26-encoding
441	id1 = 'G';	485	id1 = 'G';
442	id2 = 'V';	486	id2 = 'V';
443	id3 = 'P';	487	id3 = 'P';
444	id4 = 'E';	488	id4 = 'E';
445		489
446	version = 1;	490	version = 2;
447		491
448	rrtype = RR_TYPE_TXT;	492	rrtype = RR_TYPE_TXT;
449	flags = 0;	493	flags = 0;
450	def_ttl = 0;	494	def_ttl = 0;
451	seq_cdc = 26;	495	syn_cdc = 26;
452	req_cdc = 62;	496	hdr_cdc = 36;
		497	req_cdc = conf.dns_case_preserving ? 62 : 36;
453	rep_cdc = 0;	498	rep_cdc = 0;
454	max_size = htons (MAX_PKT_SIZE);	499	max_size = htons (MAX_PKT_SIZE);
455	client = htons (clientid);	500	client = htons (clientid);
456	uid = next_uid++;	501	uid = ++next_uid;
457		502
458	r2 = r3 = r4 = 0;	503	r0 = r1 = r2 = r3 = r4 = 0;
459	r4 = r5 = r6 = r7 = 0;
460	}
461		504
		505	chksum = get_chksum ();
		506	}
		507
		508	// simple but not trivial chksum
		509	u8
		510	dns_cfg::get_chksum ()
		511	{
		512	unsigned int sum = 0xff00; // only 16 bits required
		513
		514	u8 old_chksum = chksum;
		515	chksum = 0;
		516
		517	for (unsigned int i = 0; i < sizeof (*this); ++i)
		518	sum += ((u8 )this)[i] (i + 1);
		519
		520	chksum = old_chksum;
		521
		522	return sum + (sum >> 8);
		523	}
		524
		525	bool
462	bool dns_cfg::valid ()	526	dns_cfg::valid ()
463	{	527	{
		528	// although the protocol itself allows for some configurability,
		529	// only the following encoding/decoding settings are implemented.
464	return id1 == 'G'	530	return id1 == 'G'
465	&& id2 == 'V'	531	&& id2 == 'V'
466	&& id3 == 'P'	532	&& id3 == 'P'
467	&& id4 == 'E'	533	&& id4 == 'E'
		534	&& version == 2
468	&& seq_cdc == 26	535	&& syn_cdc == 26
469	&& req_cdc == 62	536	&& hdr_cdc == 36
		537	&& (req_cdc == 36 \|\| req_cdc == 62)
470	&& rep_cdc == 0	538	&& rep_cdc == 0
471	&& version == 1;	539	&& chksum == get_chksum ();
472	}	540	}
473		541
474	struct dns_packet : net_packet	542	struct dns_packet : net_packet
475	{	543	{
476	u16 id;	544	u16 id;
…		…
480	u8 data [MAXSIZE - 6 * 2];	548	u8 data [MAXSIZE - 6 * 2];
481		549
482	int decode_label (char *data, int size, int &offs);	550	int decode_label (char *data, int size, int &offs);
483	};	551	};
484		552
		553	int
485	int dns_packet::decode_label (char *data, int size, int &offs)	554	dns_packet::decode_label (char *data, int size, int &offs)
486	{	555	{
487	char *orig = data;	556	char *orig = data;
488		557
489	memset (data, 0, size);	558	memset (data, 0, size);
490		559
…		…
516	return data - orig;	585	return data - orig;
517	}	586	}
518		587
519	/////////////////////////////////////////////////////////////////////////////	588	/////////////////////////////////////////////////////////////////////////////
520		589
		590	static
		591	u16 next_id ()
		592	{
521	static u16 dns_id = 0; // TODO: should be per-vpn	593	static u16 dns_id = 0; // TODO: should be per-vpn
522		594
523	static u16 next_id ()	595	#if 1
524	{
525	if (!dns_id)	596	if (!dns_id)
526	dns_id = time (0);	597	dns_id = time (0);
527		598
528	// the simplest lsfr with periodicity 65535 i could find	599	// the simplest lsfr with periodicity 65535 i could find
529	dns_id = (dns_id << 1)	600	dns_id = (dns_id << 1)
…		…
531	^ (dns_id >> 2)	602	^ (dns_id >> 2)
532	^ (dns_id >> 4)	603	^ (dns_id >> 4)
533	^ (dns_id >> 15)) & 1);	604	^ (dns_id >> 15)) & 1);
534		605
535	return dns_id;	606	return dns_id;
		607	#else
		608	dns_id++;//D
		609
		610	return htons (dns_id);
		611	#endif
536	}	612	}
537		613
538	struct dns_rcv;	614	struct dns_rcv;
539	struct dns_snd;	615	struct dns_snd;
540		616
…		…
544	struct vpn *vpn;	620	struct vpn *vpn;
545		621
546	dns_cfg cfg;	622	dns_cfg cfg;
547		623
548	bool established;	624	bool established;
		625	const basecoder *cdc;
549		626
550	tstamp last_received;	627	tstamp last_received;
551	tstamp last_sent;	628	tstamp last_sent;
552	double min_latency;	629	double min_latency;
553	double poll_interval, send_interval;	630	double poll_interval, send_interval;
554		631
555	vector<dns_rcv *> rcvpq;	632	vector<dns_rcv *> rcvpq;
556		633
557	byte_stream rcvdq; int rcvseq;	634	byte_stream rcvdq; int rcvseq; int repseq;
558	byte_stream snddq; int sndseq;	635	byte_stream snddq; int sndseq;
559		636
560	void time_cb (time_watcher &w); time_watcher tw;	637	inline void time_cb (ev::timer &w, int revents); ev::timer tw;
561	void receive_rep (dns_rcv *r);	638	void receive_rep (dns_rcv *r);
		639
		640	void reset (); // quite like tcp RST
		641	void set_cfg (); // to be called after any cfg changes
562		642
563	dns_connection (connection *c);	643	dns_connection (connection *c);
564	~dns_connection ();	644	~dns_connection ();
565	};	645	};
566		646
…		…
584	: dns (dns)	664	: dns (dns)
585	{	665	{
586	timeout = 0;	666	timeout = 0;
587	retry = 0;	667	retry = 0;
588	seqno = 0;	668	seqno = 0;
589	sent = NOW;	669	sent = ev_now ();
590	stdhdr = false;	670	stdhdr = false;
591		671
592	pkt = new dns_packet;	672	pkt = new dns_packet;
593		673
594	pkt->id = next_id ();	674	pkt->id = next_id ();
…		…
597	dns_snd::~dns_snd ()	677	dns_snd::~dns_snd ()
598	{	678	{
599	delete pkt;	679	delete pkt;
600	}	680	}
601		681
		682	static void
602	static void append_domain (dns_packet &pkt, int &offs, const char *domain)	683	append_domain (dns_packet &pkt, int &offs, const char *domain)
603	{	684	{
604	// add tunnel domain	685	// add tunnel domain
605	for (;;)	686	for (;;)
606	{	687	{
607	const char *end = strchr (domain, '.');	688	const char *end = strchr (domain, '.');
…		…
620		701
621	domain = end + 1;	702	domain = end + 1;
622	}	703	}
623	}	704	}
624		705
		706	void
625	void dns_snd::gen_stream_req (int seqno, byte_stream &stream)	707	dns_snd::gen_stream_req (int seqno, byte_stream &stream)
626	{	708	{
627	stdhdr = true;	709	stdhdr = true;
628	this->seqno = seqno;	710	this->seqno = seqno;
629		711
630	timeout = NOW + INITIAL_TIMEOUT;	712	timeout = ev_now () + INITIAL_TIMEOUT;
631		713
632	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);	714	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
633	pkt->qdcount = htons (1);	715	pkt->qdcount = htons (1);
634		716
635	int offs = 6*2;	717	int offs = 6*2;
…		…
638	// so we need to have space for 2*MAX_DOMAIN_SIZE + header + extra	720	// so we need to have space for 2*MAX_DOMAIN_SIZE + header + extra
639		721
640	char enc[256], *encp = enc;	722	char enc[256], *encp = enc;
641	encode_header (enc, THISNODE->id, seqno);	723	encode_header (enc, THISNODE->id, seqno);
642		724
643	int datalen = cdc62.decode_len (dlen - (dlen + MAX_LBL_SIZE - 1) / MAX_LBL_SIZE - HDRSIZE);	725	int datalen = dns->cdc->decode_len (dlen - (dlen + MAX_LBL_SIZE - 1) / MAX_LBL_SIZE - HDRSIZE);
644		726
645	if (datalen > stream.size ())	727	if (datalen > stream.size ())
646	datalen = stream.size ();	728	datalen = stream.size ();
647		729
648	int enclen = cdc62.encode (enc + HDRSIZE, stream.begin (), datalen) + HDRSIZE;	730	int enclen = dns->cdc->encode (enc + HDRSIZE, stream.begin (), datalen) + HDRSIZE;
649	stream.remove (datalen);	731	stream.remove (datalen);
650		732
651	while (enclen)	733	while (enclen)
652	{	734	{
653	int lbllen = enclen < MAX_LBL_SIZE ? enclen : MAX_LBL_SIZE;	735	int lbllen = enclen < MAX_LBL_SIZE ? enclen : MAX_LBL_SIZE;
…		…
668	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;	750	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;
669		751
670	pkt->len = offs;	752	pkt->len = offs;
671	}	753	}
672		754
		755	void
673	void dns_snd::gen_syn_req ()	756	dns_snd::gen_syn_req ()
674	{	757	{
675	timeout = NOW + INITIAL_SYN_TIMEOUT;	758	timeout = ev_now () + INITIAL_SYN_TIMEOUT;
676		759
677	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);	760	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
678	pkt->qdcount = htons (1);	761	pkt->qdcount = htons (1);
679		762
680	int offs = 6 * 2;	763	int offs = 6 * 2;
…		…
719	/////////////////////////////////////////////////////////////////////////////	802	/////////////////////////////////////////////////////////////////////////////
720		803
721	dns_connection::dns_connection (connection *c)	804	dns_connection::dns_connection (connection *c)
722	: c (c)	805	: c (c)
723	, rcvdq (MAX_BACKLOG * 2)	806	, rcvdq (MAX_BACKLOG * 2)
724	, snddq (MAX_BACKLOG * 2)	807	, snddq (MAX_BACKLOG)
725	, tw (this, &dns_connection::time_cb)
726	{	808	{
		809	tw.set<dns_connection, &dns_connection::time_cb> (this);
		810
727	vpn = c->vpn;	811	vpn = c->vpn;
728		812
		813	reset ();
		814	}
		815
		816	dns_connection::~dns_connection ()
		817	{
		818	reset ();
		819	}
		820
		821	void
		822	dns_connection::reset ()
		823	{
		824	while (!rcvpq.empty ())
		825	{
		826	delete rcvpq.back ();
		827	rcvpq.pop_back ();
		828	}
		829
		830	for (int i = vpn->dns_sndpq.size (); i--; )
		831	if (vpn->dns_sndpq [i]->dns == this)
		832	{
		833	vpn->dns_sndpq [i] = vpn->dns_sndpq.back ();
		834	vpn->dns_sndpq.pop_back ();
		835	}
		836
729	established = false;	837	established = false;
730		838
731	rcvseq = sndseq = 0;	839	rcvseq = repseq = sndseq = 0;
732		840
733	last_sent = last_received = 0;	841	last_sent = 0;
734	poll_interval = MIN_POLL_INTERVAL;	842	poll_interval = 0.5; // starting here
735	send_interval = 0.5; // starting rate	843	send_interval = 0.5; // starting rate
736	min_latency = INITIAL_TIMEOUT;	844	min_latency = INITIAL_TIMEOUT;
737	}	845	}
738		846
739	dns_connection::~dns_connection ()	847	void
		848	dns_connection::set_cfg ()
740	{	849	{
741	for (vector<dns_rcv *>::iterator i = rcvpq.begin ();	850	cdc = cfg.req_cdc == 36 ? &cdc36 : &cdc62;
742	i != rcvpq.end ();
743	++i)
744	delete *i;
745	}	851	}
746		852
		853	void
747	void dns_connection::receive_rep (dns_rcv *r)	854	dns_connection::receive_rep (dns_rcv *r)
748	{	855	{
749	if (r->datalen)	856	if (r->datalen)
750	{	857	poll_interval = max (poll_interval * (1. / 1.2), MIN_POLL_INTERVAL);
751	last_received = NOW;
752	tw.trigger ();
753
754	poll_interval = send_interval;
755	}
756	else	858	else
757	{	859	poll_interval = min (poll_interval * 1.1, MAX_POLL_INTERVAL);
758	poll_interval *= 1.5;
759
760	if (poll_interval > MAX_POLL_INTERVAL)
761	poll_interval = MAX_POLL_INTERVAL;
762	}
763		860
764	rcvpq.push_back (r);	861	rcvpq.push_back (r);
765		862
766	redo:	863	redo:
767		864
768	// find next packet	865	// find next packet
769	for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); )	866	for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); )
770	if (SEQNO_EQ (rcvseq, (*i)->seqno))	867	if (SEQNO_EQ (rcvseq, (*i)->seqno))
771	{	868	{
		869	//printf ("seqno eq %x %x\n", rcvseq, (*i)->seqno);//D
772	// enter the packet into our input stream	870	// enter the packet into our input stream
773	r = *i;	871	r = *i;
774		872
775	// remove the oldest packet, look forward, as it's oldest first	873	// remove the oldest packet, look forward, as it's oldest first
776	for (vector<dns_rcv *>::iterator j = rcvpq.begin (); j != rcvpq.end (); ++j)	874	for (vector<dns_rcv *>::iterator j = rcvpq.begin (); j != rcvpq.end (); ++j)
777	if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW))	875	if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW))
778	{	876	{
		877	//printf ("seqno RR %x %x\n", (*j)->seqno, rcvseq - MAX_WINDOW);//D
779	delete *j;	878	delete *j;
780	rcvpq.erase (j);	879	rcvpq.erase (j);
781	break;	880	break;
782	}	881	}
783		882
784	rcvseq = (rcvseq + 1) & SEQNO_MASK;	883	rcvseq = (rcvseq + 1) & SEQNO_MASK;
785		884
786	if (!rcvdq.put (r->data, r->datalen))	885	if (!rcvdq.put (r->data, r->datalen))
787	{	886	{
		887	// MUST never overflow, can be caused by data corruption, TODO
788	slog (L_ERR, "DNS: !rcvdq.put (r->data, r->datalen)");	888	slog (L_CRIT, "DNS: !rcvdq.put (r->data, r->datalen)");
789	abort (); // MUST never overflow, can be caused by data corruption, TODO	889	reset ();
		890	return;
790	}	891	}
791		892
792	while (vpn_packet *pkt = rcvdq.get ())	893	while (vpn_packet *pkt = rcvdq.get ())
793	{	894	{
794	sockinfo si;	895	sockinfo si;
795	si.host = 0x01010101; si.port = htons (c->conf->id); si.prot = PROT_DNSv4;	896	si.host = htonl (c->conf->id); si.port = 0; si.prot = PROT_DNSv4;
796		897
797	vpn->recv_vpn_packet (pkt, si);	898	vpn->recv_vpn_packet (pkt, si);
798
799	delete pkt;	899	delete pkt;
800	}	900	}
801		901
802	// check for further packets	902	// check for further packets
803	goto redo;	903	goto redo;
…		…
846	{	946	{
847	// correct class, domain: parse	947	// correct class, domain: parse
848	int client, seqno;	948	int client, seqno;
849	decode_header (qname, client, seqno);	949	decode_header (qname, client, seqno);
850		950
851	u8 data[MAXSIZE];
852	int datalen = cdc62.decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE));
853
854	if (0 < client && client <= conns.size ())	951	if (0 < client && client <= conns.size ())
855	{	952	{
856	connection *c = conns [client - 1];	953	connection *c = conns [client - 1];
857	dns_connection *dns = c->dns;	954	dns_connection *dns = c->dns;
858	dns_rcv *rcv;	955	dns_rcv *rcv;
859	bool in_seq;
860		956
861	if (dns)	957	if (dns)
862	{	958	{
		959	u8 data[MAXSIZE];
		960	int datalen = dns->cdc->decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE));
		961
863	for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); )	962	for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); )
864	if (SEQNO_EQ ((*i)->seqno, seqno))	963	if (SEQNO_EQ ((*i)->seqno, seqno))
865	{	964	{
866	// already seen that request: simply reply with the cached reply	965	// already seen that request: simply reply with the cached reply
867	dns_rcv r = i;	966	dns_rcv r = i;
…		…
875	memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len);	974	memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len);
876		975
877	goto duplicate_request;	976	goto duplicate_request;
878	}	977	}
879		978
880	in_seq = dns->rcvseq == seqno;
881
882	// new packet, queue	979	// new packet, queue
883	rcv = new dns_rcv (seqno, data, datalen);	980	rcv = new dns_rcv (seqno, data, datalen);
884	dns->receive_rep (rcv);	981	dns->receive_rep (rcv);
885	}	982	}
886		983
…		…
903	dlen -= qlen;	1000	dlen -= qlen;
904		1001
905	// only put data into in-order sequence packets, if	1002	// only put data into in-order sequence packets, if
906	// we receive out-of-order packets we generate empty	1003	// we receive out-of-order packets we generate empty
907	// replies	1004	// replies
908	while (dlen > 1 && !dns->snddq.empty () && in_seq)	1005	//printf ("%d - %d & %x (=%d) < %d\n", seqno, dns->repseq, SEQNO_MASK, (seqno - dns->repseq) & SEQNO_MASK, MAX_WINDOW);//D
		1006	if (((seqno - dns->repseq) & SEQNO_MASK) <= MAX_WINDOW)
909	{	1007	{
		1008	dns->repseq = seqno;
		1009
		1010	while (dlen > 1 && !dns->snddq.empty ())
		1011	{
910	int txtlen = dlen <= 255 ? dlen - 1 : 255;	1012	int txtlen = dlen <= 255 ? dlen - 1 : 255;
911		1013
912	if (txtlen > dns->snddq.size ())	1014	if (txtlen > dns->snddq.size ())
913	txtlen = dns->snddq.size ();	1015	txtlen = dns->snddq.size ();
914		1016
915	pkt[offs++] = txtlen;	1017	pkt[offs++] = txtlen;
916	memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);	1018	memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
917	offs += txtlen;	1019	offs += txtlen;
918	dns->snddq.remove (txtlen);	1020	dns->snddq.remove (txtlen);
919		1021
920	dlen -= txtlen + 1;	1022	dlen -= txtlen + 1;
		1023	}
921	}	1024	}
922		1025
923	// avoid empty TXT rdata	1026	// avoid completely empty TXT rdata
924	if (offs == rdlen_offs)	1027	if (offs == rdlen_offs)
925	pkt[offs++] = 0;	1028	pkt[offs++] = 0;
926		1029
927	slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());	1030	slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
928	}	1031	}
…		…
964	pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class	1067	pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
965	pkt [offs++] = 0; pkt [offs++] = 0;	1068	pkt [offs++] = 0; pkt [offs++] = 0;
966	pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL	1069	pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL
967	pkt [offs++] = 0; pkt [offs++] = 4; // rdlength	1070	pkt [offs++] = 0; pkt [offs++] = 4; // rdlength
968		1071
969	slog (L_INFO, _("DNS: client %d connects"), client);
970
971	pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;	1072	pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
972	pkt [offs++] = CMD_IP_REJ;	1073	pkt [offs++] = CMD_IP_REJ;
973		1074
974	if (0 < client && client <= conns.size ())	1075	if (0 < client && client <= conns.size ())
975	{	1076	{
976	connection *c = conns [client - 1];	1077	connection *c = conns [client - 1];
977		1078
978	if (cfg.valid ())	1079	if (cfg.valid ())
979	{	1080	{
980	pkt [offs - 1] = CMD_IP_SYN;	1081	slog (L_INFO, _("DNS: client %d connects (version %d, req_cdc %d)"), client, cfg.version, cfg.req_cdc);
		1082
		1083	// check for any encoding mismatches - hints at a case problem
		1084	char qname2 [MAX_ENC_LEN];
		1085	cdc26.encode (qname2, (u8 *)&cfg, sizeof (dns_cfg));
981		1086
982	delete c->dns;	1087	delete c->dns;
		1088
		1089	pkt [offs - 1] = memcmp (qname, qname2, cdc26.encode_len (sizeof (dns_cfg)))
		1090	? CMD_IP_CSE : CMD_IP_SYN;
		1091
983	c->dns = new dns_connection (c);	1092	c->dns = new dns_connection (c);
984	c->dns->cfg = cfg;	1093	c->dns->cfg = cfg;
		1094	c->dns->set_cfg ();
985	}	1095	}
986	}	1096	}
987	}	1097	}
988	}	1098	}
989		1099
…		…
1008	{	1118	{
1009	dns_connection dns = (i)->dns;	1119	dns_connection dns = (i)->dns;
1010	connection *c = dns->c;	1120	connection *c = dns->c;
1011	int seqno = (*i)->seqno;	1121	int seqno = (*i)->seqno;
1012	u8 data[MAXSIZE], *datap = data;	1122	u8 data[MAXSIZE], *datap = data;
		1123	//printf ("rcv pkt %x\n", seqno);//D
1013		1124
1014	if ((*i)->retry)	1125	if ((*i)->retry)
1015	{	1126	{
1016	dns->send_interval *= 1.01;	1127	dns->send_interval *= 1.01;
1017	if (dns->send_interval > MAX_SEND_INTERVAL)	1128	if (dns->send_interval > MAX_SEND_INTERVAL)
…		…
1022	#if 0	1133	#if 0
1023	dns->send_interval *= 0.999;	1134	dns->send_interval *= 0.999;
1024	#endif	1135	#endif
1025	// the latency surely puts an upper bound on	1136	// the latency surely puts an upper bound on
1026	// the minimum send interval	1137	// the minimum send interval
1027	double latency = NOW - (*i)->sent;	1138	double latency = ev_now () - (*i)->sent;
1028		1139
1029	if (latency < dns->min_latency)	1140	if (latency < dns->min_latency)
1030	dns->min_latency = latency;	1141	dns->min_latency = latency;
1031		1142
1032	if (dns->send_interval > dns->min_latency * LATENCY_FACTOR)	1143	if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor)
1033	dns->send_interval = dns->min_latency * LATENCY_FACTOR;	1144	dns->send_interval = dns->min_latency * conf.dns_overlap_factor;
1034		1145
1035	if (dns->send_interval < MIN_SEND_INTERVAL)	1146	if (dns->send_interval < conf.dns_send_interval)
1036	dns->send_interval = MIN_SEND_INTERVAL;	1147	dns->send_interval = conf.dns_send_interval;
1037	}	1148	}
1038		1149
1039	delete *i;	1150	delete *i;
1040	dns_sndpq.erase (i);	1151	dns_sndpq.erase (i);
1041		1152
…		…
1059	ttl \|= pkt [offs++] << 16;	1170	ttl \|= pkt [offs++] << 16;
1060	ttl \|= pkt [offs++] << 8;	1171	ttl \|= pkt [offs++] << 8;
1061	ttl \|= pkt [offs++];	1172	ttl \|= pkt [offs++];
1062	u16 rdlen = pkt [offs++] << 8; rdlen \|= pkt [offs++];	1173	u16 rdlen = pkt [offs++] << 8; rdlen \|= pkt [offs++];
1063		1174
1064	if (qtype == RR_TYPE_NULL \|\| qtype == RR_TYPE_TXT)	1175	if (qtype == RR_TYPE_NULL \|\| qtype == RR_TYPE_TXT \|\| qtype == dns->cfg.rrtype)
1065	{	1176	{
1066	if (rdlen <= MAXSIZE - offs)	1177	if (rdlen <= MAXSIZE - offs)
1067	{	1178	{
1068	// decode bytes, finally	1179	// decode bytes, finally
1069		1180
…		…
1095	{	1206	{
1096	slog (L_TRACE, _("DNS: got tunnel meta command %02x"), ip [3]);	1207	slog (L_TRACE, _("DNS: got tunnel meta command %02x"), ip [3]);
1097		1208
1098	if (ip [3] == CMD_IP_RST)	1209	if (ip [3] == CMD_IP_RST)
1099	{	1210	{
1100	slog (L_DEBUG, _("DNS: got tunnel RST request"));	1211	slog (L_DEBUG, _("DNS: got tunnel RST request."));
1101		1212
1102	delete dns; c->dns = 0;	1213	dns->reset ();
1103
1104	return;	1214	return;
1105	}	1215	}
1106	else if (ip [3] == CMD_IP_SYN)	1216	else if (ip [3] == CMD_IP_SYN)
1107	{	1217	{
1108	slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us."));	1218	slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us."));
1109	dns->established = true;	1219	dns->established = true;
1110	}	1220	}
		1221	else if (ip [3] == CMD_IP_CSE)
		1222	{
		1223	if (conf.dns_case_preserving)
		1224	{
		1225	slog (L_INFO, _("DNS: got tunnel CSE reply, globally downgrading to case-insensitive protocol."));
		1226	conf.dns_case_preserving = false;
		1227	dns->reset ();
		1228	return;
		1229	}
		1230	else
		1231	{
		1232	slog (L_DEBUG, _("DNS: got tunnel CSE reply, server likes us."));
		1233	dns->established = true;
		1234	}
		1235	}
1111	else if (ip [3] == CMD_IP_REJ)	1236	else if (ip [3] == CMD_IP_REJ)
1112	{	1237	{
1113	slog (L_DEBUG, _("DNS: got tunnel REJ reply, server does not like us, aborting."));	1238	slog (L_ERR, _("DNS: got tunnel REJ reply, server does not like us."));
1114	abort ();	1239	dns->tw.start (60.);
1115	}	1240	}
1116	else	1241	else
		1242	{
1117	slog (L_INFO, _("DNS: got unknown meta command %02x"), ip [3]);	1243	slog (L_INFO, _("DNS: got unknown meta command %02x"), ip [3]);
		1244	dns->tw.start (60.);
		1245	}
1118	}	1246	}
1119	else	1247	else
1120	slog (L_INFO, _("DNS: got spurious a record %d.%d.%d.%d"),	1248	slog (L_INFO, _("DNS: got spurious a record %d.%d.%d.%d"),
1121	ip [0], ip [1], ip [2], ip [3]);	1249	ip [0], ip [1], ip [2], ip [3]);
1122		1250
…		…
1146	break;	1274	break;
1147	}	1275	}
1148	}	1276	}
1149		1277
1150	void	1278	void
1151	vpn::dnsv4_ev (io_watcher &w, short revents)	1279	vpn::dnsv4_ev (ev::io &w, int revents)
1152	{	1280	{
1153	if (revents & EVENT_READ)	1281	if (revents & EV_READ)
1154	{	1282	{
1155	dns_packet *pkt = new dns_packet;	1283	dns_packet *pkt = new dns_packet;
1156	struct sockaddr_in sa;	1284	struct sockaddr_in sa;
1157	socklen_t sa_len = sizeof (sa);	1285	socklen_t sa_len = sizeof (sa);
1158		1286
…		…
1174	}	1302	}
1175		1303
1176	bool	1304	bool
1177	vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)	1305	vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
1178	{	1306	{
1179	int client = ntohs (si.port);	1307	int client = ntohl (si.host);
1180		1308
1181	assert (0 < client && client <= conns.size ());	1309	assert (0 < client && client <= conns.size ());
1182		1310
1183	connection *c = conns [client - 1];	1311	connection *c = conns [client - 1];
1184		1312
1185	if (!c->dns)	1313	if (!c->dns)
1186	c->dns = new dns_connection (c);	1314	c->dns = new dns_connection (c);
1187		1315
1188	if (!c->dns->snddq.put (pkt))	1316	if (c->dns->snddq.put (pkt))
1189	return false;	1317	{
		1318	min_it (c->dns->poll_interval, 0.25);
		1319	c->dns->tw ();
		1320	}
1190		1321
1191	c->dns->tw.trigger ();	1322	// always return true even if the buffer overflows
1192
1193	return true;	1323	return true;
1194	}	1324	}
1195		1325
1196	void	1326	void
1197	connection::dnsv4_reset_connection ()	1327	dns_connection::time_cb (ev::timer &w, int revents)
1198	{
1199	//delete dns; dns = 0; //TODO
1200	}
1201
1202	#define NEXT(w) do { if (next > (w)) next = w; } while (0)
1203
1204	void
1205	dns_connection::time_cb (time_watcher &w)
1206	{	1328	{
1207	// servers have to be polled	1329	// servers have to be polled
1208	if (THISNODE->dns_port)	1330	if (THISNODE->dns_port)
1209	return;	1331	return;
1210		1332
1211	// check for timeouts and (re)transmit	1333	// check for timeouts and (re)transmit
1212	tstamp next = NOW + poll_interval;	1334	tstamp next = 86400 * 365;
1213	dns_snd *send = 0;	1335	dns_snd *send = 0;
1214		1336
1215	for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin ();	1337	for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin ();
1216	i != vpn->dns_sndpq.end ();	1338	i != vpn->dns_sndpq.end ();
1217	++i)	1339	++i)
1218	{	1340	{
1219	dns_snd r = i;	1341	dns_snd r = i;
1220		1342
1221	if (r->timeout <= NOW)	1343	if (r->timeout <= ev_now ())
1222	{	1344	{
1223	if (!send)	1345	if (!send)
1224	{	1346	{
1225	send = r;	1347	send = r;
1226		1348
1227	r->retry++;	1349	r->retry++;
1228	r->timeout = NOW + (r->retry * min_latency * 8.);	1350	r->timeout = ev_now () + r->retry * min_latency * conf.dns_timeout_factor;
		1351	//printf ("RETRY %x (%d, %f)\n", r->seqno, r->retry, r->timeout - ev_now ());//D
1229		1352
1230	// the following code changes the query section a bit, forcing	1353	// the following code changes the query section a bit, forcing
1231	// the forwarder to generate a new request	1354	// the forwarder to generate a new request
1232	if (r->stdhdr)	1355	if (r->stdhdr)
1233	{
1234	//printf ("reencoded header for ID %d retry %d:%d:%d (%p)\n", htons (r->pkt->id), THISNODE->id, r->seqno, r->retry);
1235	//encode_header ((char )r->pkt->at (6 2 + 1), THISNODE->id, r->seqno, r->retry);	1356	encode_header ((char )r->pkt->at (6 2 + 1), THISNODE->id, r->seqno, r->retry);
1236	}
1237	}	1357	}
1238	}	1358	}
1239	else	1359	else
1240	NEXT (r->timeout);	1360	min_it (next, r->timeout - ev_now ());
1241	}	1361	}
1242		1362
1243	if (!send)	1363	if (!send)
1244	{	1364	{
1245	// generate a new packet, if wise	1365	// generate a new packet, if wise
…		…
1249	if (vpn->dns_sndpq.empty ())	1369	if (vpn->dns_sndpq.empty ())
1250	{	1370	{
1251	send = new dns_snd (this);	1371	send = new dns_snd (this);
1252		1372
1253	cfg.reset (THISNODE->id);	1373	cfg.reset (THISNODE->id);
		1374	set_cfg ();
1254	send->gen_syn_req ();	1375	send->gen_syn_req ();
1255	}	1376	}
1256	}	1377	}
1257	else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING	1378	else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding
1258	&& !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))	1379	&& !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
1259	{	1380	{
1260	if (last_sent + send_interval <= NOW)	1381	if (last_sent + send_interval <= ev_now ())
1261	{	1382	{
1262	//printf ("sending data request etc.\n"); //D	1383	//printf ("sending data request etc.\n"); //D
1263	if (!snddq.empty () \|\| last_received + 1. > NOW)	1384	if (!snddq.empty ())
1264	{
1265	poll_interval = send_interval;
1266	NEXT (NOW + send_interval);	1385	min_it (next, send_interval);
1267	}
1268		1386
1269	send = new dns_snd (this);	1387	send = new dns_snd (this);
1270	send->gen_stream_req (sndseq, snddq);	1388	send->gen_stream_req (sndseq, snddq);
1271	send->timeout = NOW + min_latency * 8.;	1389	send->timeout = ev_now () + min_latency * conf.dns_timeout_factor;
		1390	//printf ("SEND %x (%f)\n", send->seqno, send->timeout - ev_now (), min_latency, conf.dns_timeout_factor);//D
1272		1391
1273	sndseq = (sndseq + 1) & SEQNO_MASK;	1392	sndseq = (sndseq + 1) & SEQNO_MASK;
1274	}	1393	}
1275	else	1394	else
1276	NEXT (last_sent + send_interval);	1395	min_it (next, last_sent + send_interval - ev_now ());
1277	}	1396	}
1278		1397
1279	if (send)	1398	if (send)
1280	vpn->dns_sndpq.push_back (send);	1399	vpn->dns_sndpq.push_back (send);
1281	}	1400	}
1282		1401
1283	if (send)	1402	if (send)
1284	{	1403	{
1285	last_sent = NOW;	1404	last_sent = ev_now ();
1286	sendto (vpn->dnsv4_fd,	1405	sendto (vpn->dnsv4_fd,
1287	send->pkt->at (0), send->pkt->len, 0,	1406	send->pkt->at (0), send->pkt->len, 0,
1288	vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());	1407	vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
1289	}	1408	}
1290		1409
		1410	min_it (next, last_sent + max (poll_interval, send_interval) - ev_now ());
		1411
1291	slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)",	1412	slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)",
1292	poll_interval, send_interval, next - NOW,	1413	poll_interval, send_interval, next - ev_now (),
1293	vpn->dns_sndpq.size (), snddq.size (),	1414	vpn->dns_sndpq.size (), snddq.size (),
1294	rcvpq.size ());	1415	rcvpq.size ());
1295		1416
1296	// TODO: no idea when this happens, but when next < NOW, we have a problem
1297	if (next < NOW + 0.001)
1298	next = NOW + 0.1;
1299
1300	w.start (next);	1417	w.start (next);
1301	}	1418	}
1302		1419
1303	#endif	1420	#endif
1304		1421

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Comparing gvpe/src/vpn_dns.C (file contents): Revision 1.29 by pcg, Sun Mar 13 12:40:20 2005 UTC vs. Revision 1.53 by root, Tue Oct 18 10:54:17 2011 UTC

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Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.29 by pcg, Sun Mar 13 12:40:20 2005 UTC vs.
Revision 1.53 by root, Tue Oct 18 10:54:17 2011 UTC