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

Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.30 by pcg, Mon Mar 14 17:40:01 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
		64	#define MIN_POLL_INTERVAL 0.025 // poll at most this often when no data received
49	#define MAX_POLL_INTERVAL 5. // 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
50	#define ACTIVITY_INTERVAL 5.
51		66
52	#define INITIAL_TIMEOUT 0.1 // retry timeouts	67	#define INITIAL_TIMEOUT 0.1 // retry timeouts
53	#define INITIAL_SYN_TIMEOUT 10. // retry timeout for initial syn	68	#define INITIAL_SYN_TIMEOUT 2. // retry timeout for initial syn
54		69
55	#define MIN_SEND_INTERVAL 0.001 // wait at least this time between sending requests
56	#define MAX_SEND_INTERVAL 2. // optimistic?	70	#define MAX_SEND_INTERVAL 5. // optimistic?
57		71
58	#define LATENCY_FACTOR 0.5 // RTT * LATENCY_FACTOR == sending rate
59	#define MAX_OUTSTANDING 2 // max. outstanding requests
60	#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog	72	#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog
61	#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
62		74
63	#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
64	// 240 leaves about 4 bytes of server reply data	76	// 240 leaves about 4 bytes of server reply data
65	// every two request bytes less give room for one reply byte	77	// every request byte less give room for two reply bytes
66		78
67	#define SEQNO_MASK 0x3fff	79	#define SEQNO_MASK 0x3fff
68	#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )	80	#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )
69		81
70	#define MAX_LBL_SIZE 63	82	#define MAX_LBL_SIZE 63
71	#define MAX_PKT_SIZE 512	83	#define MAX_PKT_SIZE 512
72		84
73	#define RR_TYPE_A 1	85	#define RR_TYPE_A 1
74	#define RR_TYPE_NULL 10	86	#define RR_TYPE_NULL 10
75	#define RR_TYPE_TXT 16	87	#define RR_TYPE_TXT 16
		88	#define RR_TYPE_AAAA 28
76	#define RR_TYPE_ANY 255	89	#define RR_TYPE_ANY 255
77		90
78	#define RR_CLASS_IN 1	91	#define RR_CLASS_IN 1
79		92
80	#define CMD_IP_1 207	93	#define CMD_IP_1 207
81	#define CMD_IP_2 46	94	#define CMD_IP_2 46
82	#define CMD_IP_3 236	95	#define CMD_IP_3 236
83	#define CMD_IP_RST 29	96
84	#define CMD_IP_SYN 113	97	#define CMD_IP_RST 29 // some error, reset and retry
85	#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	}
86		113
87	// works for cmaps up to 255 (not 256!)	114	// works for cmaps up to 255 (not 256!)
88	struct charmap	115	struct charmap
89	{	116	{
90	enum { INVALID = (u8)255 };	117	enum { INVALID = (u8)255 };
…		…
104	memset (enc, (char) 0, 256);	131	memset (enc, (char) 0, 256);
105	memset (dec, (char)INVALID, 256);	132	memset (dec, (char)INVALID, 256);
106		133
107	for (size = 0; cmap [size]; size++)	134	for (size = 0; cmap [size]; size++)
108	{	135	{
		136	char c = cmap [size];
		137
109	enc [size] = cmap [size];	138	enc [size] = c;
110	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;
111	}	144	}
112		145
113	assert (size < 256);	146	assert (size < 256);
114	}	147	}
115		148
…		…
122	{	155	{
123	charmap cmap;	156	charmap cmap;
124	unsigned int enc_len [MAX_DEC_LEN];	157	unsigned int enc_len [MAX_DEC_LEN];
125	unsigned int dec_len [MAX_ENC_LEN];	158	unsigned int dec_len [MAX_ENC_LEN];
126		159
127	unsigned int encode_len (unsigned int len);	160	unsigned int encode_len (unsigned int len) const;
128	unsigned int decode_len (unsigned int len);	161	unsigned int decode_len (unsigned int len) const;
129		162
130	unsigned int encode (char dst, u8 src, unsigned int len);	163	unsigned int encode (char dst, u8 src, unsigned int len) const;
131	unsigned int decode (u8 dst, char src, unsigned int len);	164	unsigned int decode (u8 dst, char src, unsigned int len) const;
132		165
133	basecoder (const char *cmap);	166	basecoder (const char *cmap);
134	};	167	};
135		168
136	basecoder::basecoder (const char *cmap)	169	basecoder::basecoder (const char *cmap)
…		…
155	enc_len [len] = n;	188	enc_len [len] = n;
156	dec_len [n] = len;	189	dec_len [n] = len;
157	}	190	}
158	}	191	}
159		192
		193	unsigned int
160	unsigned int basecoder::encode_len (unsigned int len)	194	basecoder::encode_len (unsigned int len) const
161	{	195	{
162	return enc_len [len];	196	return enc_len [len];
163	}	197	}
164		198
		199	unsigned int
165	unsigned int basecoder::decode_len (unsigned int len)	200	basecoder::decode_len (unsigned int len) const
166	{	201	{
167	while (len && !dec_len [len])	202	while (len && !dec_len [len])
168	--len;	203	--len;
169		204
170	return dec_len [len];	205	return dec_len [len];
171	}	206	}
172		207
		208	unsigned int
173	unsigned int basecoder::encode (char dst, u8 src, unsigned int len)	209	basecoder::encode (char dst, u8 src, unsigned int len) const
174	{	210	{
175	if (!len \|\| len > MAX_DEC_LEN)	211	if (!len \|\| len > MAX_DEC_LEN)
176	return 0;	212	return 0;
177		213
178	int elen = encode_len (len);	214	int elen = encode_len (len);
…		…
197	*dst++ = cmap.encode [dst_ [i]];	233	*dst++ = cmap.encode [dst_ [i]];
198		234
199	return elen;	235	return elen;
200	}	236	}
201		237
		238	unsigned int
202	unsigned int basecoder::decode (u8 dst, char src, unsigned int len)	239	basecoder::decode (u8 dst, char src, unsigned int len) const
203	{	240	{
204	if (!len \|\| len > MAX_ENC_LEN)	241	if (!len \|\| len > MAX_ENC_LEN)
205	return 0;	242	return 0;
206		243
207	u8 src_ [MAX_ENC_LEN];	244	u8 src_ [MAX_ENC_LEN];
…		…
256	}	293	}
257	abort ();	294	abort ();
258	}	295	}
259	#endif	296	#endif
260		297
261	//static basecoder cdc64 ("_dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI-");
262	//static basecoder cdc63 ("_dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI");
263	static basecoder cdc62 ("dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI");	298	static basecoder cdc62 ("dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI"); // a-zA-Z0-9
264	//static basecoder cdc36 ("dphzr06qmjkb34tsvl81xaef92wgyo57ucni"); // unused as of yet	299	static basecoder cdc36 ("dPhZr06QmJkB34tSvL81xAeF92wGyO57uCnI"); // a-z0-9 for case-changers
265	static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO");	300	static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyOuCnI"); // a-z
266		301
267	/////////////////////////////////////////////////////////////////////////////	302	/////////////////////////////////////////////////////////////////////////////
268		303
269	#define HDRSIZE 6	304	#define HDRSIZE 5
270		305
		306	inline void
271	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)
272	{	308	{
		309	assert (clientid < 256);
		310
273	seqno &= SEQNO_MASK;	311	seqno &= SEQNO_MASK;
274		312
275	u8 hdr[3] = {	313	u8 hdr[3] = {
		314	seqno,
		315	(seqno >> 8) \| (retry << 6),
276	clientid,	316	clientid,
277	(seqno >> 8) \| (retry << 6),
278	seqno,
279	};	317	};
280		318
281	assert (clientid < 256);
282
283	cdc26.encode (data, hdr, 3);	319	cdc36.encode (data, hdr, 3);
284	}	320	}
285		321
		322	inline void
286	inline void decode_header (char *data, int &clientid, int &seqno)	323	decode_header (char *data, int &clientid, int &seqno)
287	{	324	{
288	u8 hdr[3];	325	u8 hdr[3];
289		326
290	cdc26.decode (hdr, data, HDRSIZE);	327	cdc36.decode (hdr, data, HDRSIZE);
291		328
292	clientid = hdr[0];	329	clientid = hdr[2];
293	seqno = ((hdr[1] << 8) \| hdr[2]) & SEQNO_MASK;	330	seqno = ((hdr[1] << 8) \| hdr[0]) & SEQNO_MASK;
294	}	331	}
295		332
296	/////////////////////////////////////////////////////////////////////////////	333	/////////////////////////////////////////////////////////////////////////////
297		334
298	struct byte_stream	335	struct byte_stream
…		…
324	byte_stream::~byte_stream ()	361	byte_stream::~byte_stream ()
325	{	362	{
326	delete data;	363	delete data;
327	}	364	}
328		365
		366	void
329	void byte_stream::remove (int count)	367	byte_stream::remove (int count)
330	{	368	{
331	if (count > fill)	369	if (count > fill)
332	assert (count <= fill);	370	assert (count <= fill);
333		371
334	memmove (data, data + count, fill -= count);	372	memmove (data, data + count, fill -= count);
335	}	373	}
336		374
		375	bool
337	bool byte_stream::put (u8 *data, unsigned int datalen)	376	byte_stream::put (u8 *data, unsigned int datalen)
338	{	377	{
339	if (maxsize - fill < datalen)	378	if (maxsize - fill < datalen)
340	return false;	379	return false;
341		380
342	memcpy (this->data + fill, data, datalen); fill += datalen;	381	memcpy (this->data + fill, data, datalen); fill += datalen;
343		382
344	return true;	383	return true;
345	}	384	}
346		385
		386	bool
347	bool byte_stream::put (vpn_packet *pkt)	387	byte_stream::put (vpn_packet *pkt)
348	{	388	{
349	if (maxsize - fill < pkt->len + 2)	389	if (maxsize - fill < pkt->len + 2)
350	return false;	390	return false;
351		391
352	data [fill++] = pkt->len >> 8;	392	data [fill++] = pkt->len >> 8;
…		…
408		448
409	struct dns_cfg	449	struct dns_cfg
410	{	450	{
411	static int next_uid;	451	static int next_uid;
412		452
413	u8 id1, id2, id3, id4;	453	u8 chksum;
		454	u8 rrtype;
		455	u16 uid; // to make request unique
414		456
415	u8 version;	457	u8 version;
416	u8 flags;	458	u8 flags;
417	u8 rrtype;	459	u16 max_size;
		460
		461	u8 id1, id2, id3, id4;
		462
		463	u16 client;
418	u8 def_ttl;	464	u8 def_ttl;
		465	u8 r0;
419		466
420	u16 client;	467	u8 syn_cdc; // cdc en/decoder for syn (A?) requests
421	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
422		471
423	u16 max_size;
424	u8 seq_cdc;
425	u8 req_cdc;
426
427	u8 rep_cdc;
428	u8 delay; // time in 0.01s units that the server may delay replying packets
429	u8 r3, r4;
430
431	u8 r5, r6, r7, r8;	472	u8 r1, r2, r3, r4;
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	delay = 0;
458		502
459	r3 = r4 = 0;	503	r0 = r1 = r2 = r3 = r4 = 0;
460	r4 = r5 = r6 = r7 = 0;
461	}
462		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
463	bool dns_cfg::valid ()	526	dns_cfg::valid ()
464	{	527	{
		528	// although the protocol itself allows for some configurability,
		529	// only the following encoding/decoding settings are implemented.
465	return id1 == 'G'	530	return id1 == 'G'
466	&& id2 == 'V'	531	&& id2 == 'V'
467	&& id3 == 'P'	532	&& id3 == 'P'
468	&& id4 == 'E'	533	&& id4 == 'E'
		534	&& version == 2
469	&& seq_cdc == 26	535	&& syn_cdc == 26
470	&& req_cdc == 62	536	&& hdr_cdc == 36
		537	&& (req_cdc == 36 \|\| req_cdc == 62)
471	&& rep_cdc == 0	538	&& rep_cdc == 0
472	&& version == 1;	539	&& chksum == get_chksum ();
473	}	540	}
474		541
475	struct dns_packet : net_packet	542	struct dns_packet : net_packet
476	{	543	{
477	u16 id;	544	u16 id;
…		…
481	u8 data [MAXSIZE - 6 * 2];	548	u8 data [MAXSIZE - 6 * 2];
482		549
483	int decode_label (char *data, int size, int &offs);	550	int decode_label (char *data, int size, int &offs);
484	};	551	};
485		552
		553	int
486	int dns_packet::decode_label (char *data, int size, int &offs)	554	dns_packet::decode_label (char *data, int size, int &offs)
487	{	555	{
488	char *orig = data;	556	char *orig = data;
489		557
490	memset (data, 0, size);	558	memset (data, 0, size);
491		559
…		…
517	return data - orig;	585	return data - orig;
518	}	586	}
519		587
520	/////////////////////////////////////////////////////////////////////////////	588	/////////////////////////////////////////////////////////////////////////////
521		589
		590	static
		591	u16 next_id ()
		592	{
522	static u16 dns_id = 0; // TODO: should be per-vpn	593	static u16 dns_id = 0; // TODO: should be per-vpn
523		594
524	static u16 next_id ()	595	#if 1
525	{
526	if (!dns_id)	596	if (!dns_id)
527	dns_id = time (0);	597	dns_id = time (0);
528		598
529	// the simplest lsfr with periodicity 65535 i could find	599	// the simplest lsfr with periodicity 65535 i could find
530	dns_id = (dns_id << 1)	600	dns_id = (dns_id << 1)
…		…
532	^ (dns_id >> 2)	602	^ (dns_id >> 2)
533	^ (dns_id >> 4)	603	^ (dns_id >> 4)
534	^ (dns_id >> 15)) & 1);	604	^ (dns_id >> 15)) & 1);
535		605
536	return dns_id;	606	return dns_id;
		607	#else
		608	dns_id++;//D
		609
		610	return htons (dns_id);
		611	#endif
537	}	612	}
538		613
539	struct dns_rcv;	614	struct dns_rcv;
540	struct dns_snd;	615	struct dns_snd;
541		616
…		…
545	struct vpn *vpn;	620	struct vpn *vpn;
546		621
547	dns_cfg cfg;	622	dns_cfg cfg;
548		623
549	bool established;	624	bool established;
		625	const basecoder *cdc;
550		626
551	tstamp last_received;	627	tstamp last_received;
552	tstamp last_sent;	628	tstamp last_sent;
553	double min_latency;	629	double min_latency;
554	double poll_interval, send_interval;	630	double poll_interval, send_interval;
555		631
556	vector<dns_rcv *> rcvpq;	632	vector<dns_rcv *> rcvpq;
557		633
558	byte_stream rcvdq; int rcvseq;	634	byte_stream rcvdq; int rcvseq; int repseq;
559	byte_stream snddq; int sndseq;	635	byte_stream snddq; int sndseq;
560		636
561	void time_cb (time_watcher &w); time_watcher tw;	637	inline void time_cb (ev::timer &w, int revents); ev::timer tw;
562	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
563		642
564	dns_connection (connection *c);	643	dns_connection (connection *c);
565	~dns_connection ();	644	~dns_connection ();
566	};	645	};
567		646
…		…
585	: dns (dns)	664	: dns (dns)
586	{	665	{
587	timeout = 0;	666	timeout = 0;
588	retry = 0;	667	retry = 0;
589	seqno = 0;	668	seqno = 0;
590	sent = NOW;	669	sent = ev_now ();
591	stdhdr = false;	670	stdhdr = false;
592		671
593	pkt = new dns_packet;	672	pkt = new dns_packet;
594		673
595	pkt->id = next_id ();	674	pkt->id = next_id ();
…		…
598	dns_snd::~dns_snd ()	677	dns_snd::~dns_snd ()
599	{	678	{
600	delete pkt;	679	delete pkt;
601	}	680	}
602		681
		682	static void
603	static void append_domain (dns_packet &pkt, int &offs, const char *domain)	683	append_domain (dns_packet &pkt, int &offs, const char *domain)
604	{	684	{
605	// add tunnel domain	685	// add tunnel domain
606	for (;;)	686	for (;;)
607	{	687	{
608	const char *end = strchr (domain, '.');	688	const char *end = strchr (domain, '.');
…		…
621		701
622	domain = end + 1;	702	domain = end + 1;
623	}	703	}
624	}	704	}
625		705
		706	void
626	void dns_snd::gen_stream_req (int seqno, byte_stream &stream)	707	dns_snd::gen_stream_req (int seqno, byte_stream &stream)
627	{	708	{
628	stdhdr = true;	709	stdhdr = true;
629	this->seqno = seqno;	710	this->seqno = seqno;
630		711
631	timeout = NOW + INITIAL_TIMEOUT;	712	timeout = ev_now () + INITIAL_TIMEOUT;
632		713
633	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);	714	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
634	pkt->qdcount = htons (1);	715	pkt->qdcount = htons (1);
635		716
636	int offs = 6*2;	717	int offs = 6*2;
…		…
639	// 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
640		721
641	char enc[256], *encp = enc;	722	char enc[256], *encp = enc;
642	encode_header (enc, THISNODE->id, seqno);	723	encode_header (enc, THISNODE->id, seqno);
643		724
644	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);
645		726
646	if (datalen > stream.size ())	727	if (datalen > stream.size ())
647	datalen = stream.size ();	728	datalen = stream.size ();
648		729
649	int enclen = cdc62.encode (enc + HDRSIZE, stream.begin (), datalen) + HDRSIZE;	730	int enclen = dns->cdc->encode (enc + HDRSIZE, stream.begin (), datalen) + HDRSIZE;
650	stream.remove (datalen);	731	stream.remove (datalen);
651		732
652	while (enclen)	733	while (enclen)
653	{	734	{
654	int lbllen = enclen < MAX_LBL_SIZE ? enclen : MAX_LBL_SIZE;	735	int lbllen = enclen < MAX_LBL_SIZE ? enclen : MAX_LBL_SIZE;
…		…
669	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;	750	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;
670		751
671	pkt->len = offs;	752	pkt->len = offs;
672	}	753	}
673		754
		755	void
674	void dns_snd::gen_syn_req ()	756	dns_snd::gen_syn_req ()
675	{	757	{
676	timeout = NOW + INITIAL_SYN_TIMEOUT;	758	timeout = ev_now () + INITIAL_SYN_TIMEOUT;
677		759
678	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);	760	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
679	pkt->qdcount = htons (1);	761	pkt->qdcount = htons (1);
680		762
681	int offs = 6 * 2;	763	int offs = 6 * 2;
…		…
720	/////////////////////////////////////////////////////////////////////////////	802	/////////////////////////////////////////////////////////////////////////////
721		803
722	dns_connection::dns_connection (connection *c)	804	dns_connection::dns_connection (connection *c)
723	: c (c)	805	: c (c)
724	, rcvdq (MAX_BACKLOG * 2)	806	, rcvdq (MAX_BACKLOG * 2)
725	, snddq (MAX_BACKLOG * 2)	807	, snddq (MAX_BACKLOG)
726	, tw (this, &dns_connection::time_cb)
727	{	808	{
		809	tw.set<dns_connection, &dns_connection::time_cb> (this);
		810
728	vpn = c->vpn;	811	vpn = c->vpn;
729		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
730	established = false;	837	established = false;
731		838
732	rcvseq = sndseq = 0;	839	rcvseq = repseq = sndseq = 0;
733		840
734	last_sent = last_received = 0;	841	last_sent = 0;
735	poll_interval = 0.5; // starting here	842	poll_interval = 0.5; // starting here
736	send_interval = 0.5; // starting rate	843	send_interval = 0.5; // starting rate
737	min_latency = INITIAL_TIMEOUT;	844	min_latency = INITIAL_TIMEOUT;
738	}	845	}
739		846
740	dns_connection::~dns_connection ()	847	void
		848	dns_connection::set_cfg ()
741	{	849	{
742	for (vector<dns_rcv *>::iterator i = rcvpq.begin ();	850	cdc = cfg.req_cdc == 36 ? &cdc36 : &cdc62;
743	i != rcvpq.end ();
744	++i)
745	delete *i;
746	}	851	}
747		852
		853	void
748	void dns_connection::receive_rep (dns_rcv *r)	854	dns_connection::receive_rep (dns_rcv *r)
749	{	855	{
750	if (r->datalen)	856	if (r->datalen)
751	{	857	poll_interval = max (poll_interval * (1. / 1.2), MIN_POLL_INTERVAL);
752	last_received = NOW;
753	tw.trigger ();
754
755	poll_interval = send_interval;
756	}
757	else	858	else
758	{	859	poll_interval = min (poll_interval * 1.1, MAX_POLL_INTERVAL);
759	poll_interval *= 1.5;
760
761	if (poll_interval > MAX_POLL_INTERVAL)
762	poll_interval = MAX_POLL_INTERVAL;
763	}
764		860
765	rcvpq.push_back (r);	861	rcvpq.push_back (r);
766		862
767	redo:	863	redo:
768		864
769	// find next packet	865	// find next packet
770	for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); )	866	for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); )
771	if (SEQNO_EQ (rcvseq, (*i)->seqno))	867	if (SEQNO_EQ (rcvseq, (*i)->seqno))
772	{	868	{
		869	//printf ("seqno eq %x %x\n", rcvseq, (*i)->seqno);//D
773	// enter the packet into our input stream	870	// enter the packet into our input stream
774	r = *i;	871	r = *i;
775		872
776	// remove the oldest packet, look forward, as it's oldest first	873	// remove the oldest packet, look forward, as it's oldest first
777	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)
778	if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW))	875	if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW))
779	{	876	{
		877	//printf ("seqno RR %x %x\n", (*j)->seqno, rcvseq - MAX_WINDOW);//D
780	delete *j;	878	delete *j;
781	rcvpq.erase (j);	879	rcvpq.erase (j);
782	break;	880	break;
783	}	881	}
784		882
785	rcvseq = (rcvseq + 1) & SEQNO_MASK;	883	rcvseq = (rcvseq + 1) & SEQNO_MASK;
786		884
787	if (!rcvdq.put (r->data, r->datalen))	885	if (!rcvdq.put (r->data, r->datalen))
788	{	886	{
		887	// MUST never overflow, can be caused by data corruption, TODO
789	slog (L_ERR, "DNS: !rcvdq.put (r->data, r->datalen)");	888	slog (L_CRIT, "DNS: !rcvdq.put (r->data, r->datalen)");
790	abort (); // MUST never overflow, can be caused by data corruption, TODO	889	reset ();
		890	return;
791	}	891	}
792		892
793	while (vpn_packet *pkt = rcvdq.get ())	893	while (vpn_packet *pkt = rcvdq.get ())
794	{	894	{
795	sockinfo si;	895	sockinfo si;
796	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;
797		897
798	vpn->recv_vpn_packet (pkt, si);	898	vpn->recv_vpn_packet (pkt, si);
799
800	delete pkt;	899	delete pkt;
801	}	900	}
802		901
803	// check for further packets	902	// check for further packets
804	goto redo;	903	goto redo;
…		…
847	{	946	{
848	// correct class, domain: parse	947	// correct class, domain: parse
849	int client, seqno;	948	int client, seqno;
850	decode_header (qname, client, seqno);	949	decode_header (qname, client, seqno);
851		950
852	u8 data[MAXSIZE];
853	int datalen = cdc62.decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE));
854
855	if (0 < client && client <= conns.size ())	951	if (0 < client && client <= conns.size ())
856	{	952	{
857	connection *c = conns [client - 1];	953	connection *c = conns [client - 1];
858	dns_connection *dns = c->dns;	954	dns_connection *dns = c->dns;
859	dns_rcv *rcv;	955	dns_rcv *rcv;
860	bool in_seq;
861		956
862	if (dns)	957	if (dns)
863	{	958	{
		959	u8 data[MAXSIZE];
		960	int datalen = dns->cdc->decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE));
		961
864	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 (); )
865	if (SEQNO_EQ ((*i)->seqno, seqno))	963	if (SEQNO_EQ ((*i)->seqno, seqno))
866	{	964	{
867	// already seen that request: simply reply with the cached reply	965	// already seen that request: simply reply with the cached reply
868	dns_rcv r = i;	966	dns_rcv r = i;
…		…
876	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);
877		975
878	goto duplicate_request;	976	goto duplicate_request;
879	}	977	}
880		978
881	in_seq = dns->rcvseq == seqno;
882
883	// new packet, queue	979	// new packet, queue
884	rcv = new dns_rcv (seqno, data, datalen);	980	rcv = new dns_rcv (seqno, data, datalen);
885	dns->receive_rep (rcv);	981	dns->receive_rep (rcv);
886	}	982	}
887		983
…		…
904	dlen -= qlen;	1000	dlen -= qlen;
905		1001
906	// only put data into in-order sequence packets, if	1002	// only put data into in-order sequence packets, if
907	// we receive out-of-order packets we generate empty	1003	// we receive out-of-order packets we generate empty
908	// replies	1004	// replies
909	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)
910	{	1007	{
		1008	dns->repseq = seqno;
		1009
		1010	while (dlen > 1 && !dns->snddq.empty ())
		1011	{
911	int txtlen = dlen <= 255 ? dlen - 1 : 255;	1012	int txtlen = dlen <= 255 ? dlen - 1 : 255;
912		1013
913	if (txtlen > dns->snddq.size ())	1014	if (txtlen > dns->snddq.size ())
914	txtlen = dns->snddq.size ();	1015	txtlen = dns->snddq.size ();
915		1016
916	pkt[offs++] = txtlen;	1017	pkt[offs++] = txtlen;
917	memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);	1018	memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
918	offs += txtlen;	1019	offs += txtlen;
919	dns->snddq.remove (txtlen);	1020	dns->snddq.remove (txtlen);
920		1021
921	dlen -= txtlen + 1;	1022	dlen -= txtlen + 1;
		1023	}
922	}	1024	}
923		1025
924	// avoid empty TXT rdata	1026	// avoid completely empty TXT rdata
925	if (offs == rdlen_offs)	1027	if (offs == rdlen_offs)
926	pkt[offs++] = 0;	1028	pkt[offs++] = 0;
927		1029
928	slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());	1030	slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
929	}	1031	}
…		…
965	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
966	pkt [offs++] = 0; pkt [offs++] = 0;	1068	pkt [offs++] = 0; pkt [offs++] = 0;
967	pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL	1069	pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL
968	pkt [offs++] = 0; pkt [offs++] = 4; // rdlength	1070	pkt [offs++] = 0; pkt [offs++] = 4; // rdlength
969		1071
970	slog (L_INFO, _("DNS: client %d connects"), client);
971
972	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;
973	pkt [offs++] = CMD_IP_REJ;	1073	pkt [offs++] = CMD_IP_REJ;
974		1074
975	if (0 < client && client <= conns.size ())	1075	if (0 < client && client <= conns.size ())
976	{	1076	{
977	connection *c = conns [client - 1];	1077	connection *c = conns [client - 1];
978		1078
979	if (cfg.valid ())	1079	if (cfg.valid ())
980	{	1080	{
981	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));
982		1086
983	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
984	c->dns = new dns_connection (c);	1092	c->dns = new dns_connection (c);
985	c->dns->cfg = cfg;	1093	c->dns->cfg = cfg;
		1094	c->dns->set_cfg ();
986	}	1095	}
987	}	1096	}
988	}	1097	}
989	}	1098	}
990		1099
…		…
1009	{	1118	{
1010	dns_connection dns = (i)->dns;	1119	dns_connection dns = (i)->dns;
1011	connection *c = dns->c;	1120	connection *c = dns->c;
1012	int seqno = (*i)->seqno;	1121	int seqno = (*i)->seqno;
1013	u8 data[MAXSIZE], *datap = data;	1122	u8 data[MAXSIZE], *datap = data;
		1123	//printf ("rcv pkt %x\n", seqno);//D
1014		1124
1015	if ((*i)->retry)	1125	if ((*i)->retry)
1016	{	1126	{
1017	dns->send_interval *= 1.01;	1127	dns->send_interval *= 1.01;
1018	if (dns->send_interval > MAX_SEND_INTERVAL)	1128	if (dns->send_interval > MAX_SEND_INTERVAL)
…		…
1023	#if 0	1133	#if 0
1024	dns->send_interval *= 0.999;	1134	dns->send_interval *= 0.999;
1025	#endif	1135	#endif
1026	// the latency surely puts an upper bound on	1136	// the latency surely puts an upper bound on
1027	// the minimum send interval	1137	// the minimum send interval
1028	double latency = NOW - (*i)->sent;	1138	double latency = ev_now () - (*i)->sent;
1029		1139
1030	if (latency < dns->min_latency)	1140	if (latency < dns->min_latency)
1031	dns->min_latency = latency;	1141	dns->min_latency = latency;
1032		1142
1033	if (dns->send_interval > dns->min_latency * LATENCY_FACTOR)	1143	if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor)
1034	dns->send_interval = dns->min_latency * LATENCY_FACTOR;	1144	dns->send_interval = dns->min_latency * conf.dns_overlap_factor;
1035		1145
1036	if (dns->send_interval < MIN_SEND_INTERVAL)	1146	if (dns->send_interval < conf.dns_send_interval)
1037	dns->send_interval = MIN_SEND_INTERVAL;	1147	dns->send_interval = conf.dns_send_interval;
1038	}	1148	}
1039		1149
1040	delete *i;	1150	delete *i;
1041	dns_sndpq.erase (i);	1151	dns_sndpq.erase (i);
1042		1152
…		…
1060	ttl \|= pkt [offs++] << 16;	1170	ttl \|= pkt [offs++] << 16;
1061	ttl \|= pkt [offs++] << 8;	1171	ttl \|= pkt [offs++] << 8;
1062	ttl \|= pkt [offs++];	1172	ttl \|= pkt [offs++];
1063	u16 rdlen = pkt [offs++] << 8; rdlen \|= pkt [offs++];	1173	u16 rdlen = pkt [offs++] << 8; rdlen \|= pkt [offs++];
1064		1174
1065	if (qtype == RR_TYPE_NULL \|\| qtype == RR_TYPE_TXT)	1175	if (qtype == RR_TYPE_NULL \|\| qtype == RR_TYPE_TXT \|\| qtype == dns->cfg.rrtype)
1066	{	1176	{
1067	if (rdlen <= MAXSIZE - offs)	1177	if (rdlen <= MAXSIZE - offs)
1068	{	1178	{
1069	// decode bytes, finally	1179	// decode bytes, finally
1070		1180
…		…
1096	{	1206	{
1097	slog (L_TRACE, _("DNS: got tunnel meta command %02x"), ip [3]);	1207	slog (L_TRACE, _("DNS: got tunnel meta command %02x"), ip [3]);
1098		1208
1099	if (ip [3] == CMD_IP_RST)	1209	if (ip [3] == CMD_IP_RST)
1100	{	1210	{
1101	slog (L_DEBUG, _("DNS: got tunnel RST request"));	1211	slog (L_DEBUG, _("DNS: got tunnel RST request."));
1102		1212
1103	delete dns; c->dns = 0;	1213	dns->reset ();
1104
1105	return;	1214	return;
1106	}	1215	}
1107	else if (ip [3] == CMD_IP_SYN)	1216	else if (ip [3] == CMD_IP_SYN)
1108	{	1217	{
1109	slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us."));	1218	slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us."));
1110	dns->established = true;	1219	dns->established = true;
1111	}	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	}
1112	else if (ip [3] == CMD_IP_REJ)	1236	else if (ip [3] == CMD_IP_REJ)
1113	{	1237	{
1114	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."));
1115	abort ();	1239	dns->tw.start (60.);
1116	}	1240	}
1117	else	1241	else
		1242	{
1118	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	}
1119	}	1246	}
1120	else	1247	else
1121	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"),
1122	ip [0], ip [1], ip [2], ip [3]);	1249	ip [0], ip [1], ip [2], ip [3]);
1123		1250
…		…
1147	break;	1274	break;
1148	}	1275	}
1149	}	1276	}
1150		1277
1151	void	1278	void
1152	vpn::dnsv4_ev (io_watcher &w, short revents)	1279	vpn::dnsv4_ev (ev::io &w, int revents)
1153	{	1280	{
1154	if (revents & EVENT_READ)	1281	if (revents & EV_READ)
1155	{	1282	{
1156	dns_packet *pkt = new dns_packet;	1283	dns_packet *pkt = new dns_packet;
1157	struct sockaddr_in sa;	1284	struct sockaddr_in sa;
1158	socklen_t sa_len = sizeof (sa);	1285	socklen_t sa_len = sizeof (sa);
1159		1286
…		…
1175	}	1302	}
1176		1303
1177	bool	1304	bool
1178	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)
1179	{	1306	{
1180	int client = ntohs (si.port);	1307	int client = ntohl (si.host);
1181		1308
1182	assert (0 < client && client <= conns.size ());	1309	assert (0 < client && client <= conns.size ());
1183		1310
1184	connection *c = conns [client - 1];	1311	connection *c = conns [client - 1];
1185		1312
1186	if (!c->dns)	1313	if (!c->dns)
1187	c->dns = new dns_connection (c);	1314	c->dns = new dns_connection (c);
1188		1315
1189	if (!c->dns->snddq.put (pkt))	1316	if (c->dns->snddq.put (pkt))
1190	return false;	1317	{
		1318	min_it (c->dns->poll_interval, 0.25);
		1319	c->dns->tw ();
		1320	}
1191		1321
1192	c->dns->tw.trigger ();	1322	// always return true even if the buffer overflows
1193
1194	return true;	1323	return true;
1195	}	1324	}
1196		1325
1197	void	1326	void
1198	connection::dnsv4_reset_connection ()	1327	dns_connection::time_cb (ev::timer &w, int revents)
1199	{
1200	//delete dns; dns = 0; //TODO
1201	}
1202
1203	#define NEXT(w) do { if (next > (w)) next = w; } while (0)
1204
1205	void
1206	dns_connection::time_cb (time_watcher &w)
1207	{	1328	{
1208	// servers have to be polled	1329	// servers have to be polled
1209	if (THISNODE->dns_port)	1330	if (THISNODE->dns_port)
1210	return;	1331	return;
1211		1332
1212	// check for timeouts and (re)transmit	1333	// check for timeouts and (re)transmit
1213	tstamp next = NOW + poll_interval;	1334	tstamp next = 86400 * 365;
1214	dns_snd *send = 0;	1335	dns_snd *send = 0;
1215		1336
1216	for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin ();	1337	for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin ();
1217	i != vpn->dns_sndpq.end ();	1338	i != vpn->dns_sndpq.end ();
1218	++i)	1339	++i)
1219	{	1340	{
1220	dns_snd r = i;	1341	dns_snd r = i;
1221		1342
1222	if (r->timeout <= NOW)	1343	if (r->timeout <= ev_now ())
1223	{	1344	{
1224	if (!send)	1345	if (!send)
1225	{	1346	{
1226	send = r;	1347	send = r;
1227		1348
1228	r->retry++;	1349	r->retry++;
1229	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
1230		1352
1231	// the following code changes the query section a bit, forcing	1353	// the following code changes the query section a bit, forcing
1232	// the forwarder to generate a new request	1354	// the forwarder to generate a new request
1233	if (r->stdhdr)	1355	if (r->stdhdr)
1234	{
1235	//printf ("reencoded header for ID %d retry %d:%d:%d (%p)\n", htons (r->pkt->id), THISNODE->id, r->seqno, r->retry);
1236	//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);
1237	}
1238	}	1357	}
1239	}	1358	}
1240	else	1359	else
1241	NEXT (r->timeout);	1360	min_it (next, r->timeout - ev_now ());
1242	}	1361	}
1243		1362
1244	if (!send)	1363	if (!send)
1245	{	1364	{
1246	// generate a new packet, if wise	1365	// generate a new packet, if wise
…		…
1250	if (vpn->dns_sndpq.empty ())	1369	if (vpn->dns_sndpq.empty ())
1251	{	1370	{
1252	send = new dns_snd (this);	1371	send = new dns_snd (this);
1253		1372
1254	cfg.reset (THISNODE->id);	1373	cfg.reset (THISNODE->id);
		1374	set_cfg ();
1255	send->gen_syn_req ();	1375	send->gen_syn_req ();
1256	}	1376	}
1257	}	1377	}
1258	else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING	1378	else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding
1259	&& !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))	1379	&& !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
1260	{	1380	{
1261	if (last_sent + send_interval <= NOW)	1381	if (last_sent + send_interval <= ev_now ())
1262	{	1382	{
1263	//printf ("sending data request etc.\n"); //D	1383	//printf ("sending data request etc.\n"); //D
1264	if (!snddq.empty () \|\| last_received + 1. > NOW)	1384	if (!snddq.empty ())
1265	{
1266	poll_interval = send_interval;
1267	NEXT (NOW + send_interval);	1385	min_it (next, send_interval);
1268	}
1269		1386
1270	send = new dns_snd (this);	1387	send = new dns_snd (this);
1271	send->gen_stream_req (sndseq, snddq);	1388	send->gen_stream_req (sndseq, snddq);
1272	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
1273		1391
1274	sndseq = (sndseq + 1) & SEQNO_MASK;	1392	sndseq = (sndseq + 1) & SEQNO_MASK;
1275	}	1393	}
1276	else	1394	else
1277	NEXT (last_sent + send_interval);	1395	min_it (next, last_sent + send_interval - ev_now ());
1278	}	1396	}
1279		1397
1280	if (send)	1398	if (send)
1281	vpn->dns_sndpq.push_back (send);	1399	vpn->dns_sndpq.push_back (send);
1282	}	1400	}
1283		1401
1284	if (send)	1402	if (send)
1285	{	1403	{
1286	last_sent = NOW;	1404	last_sent = ev_now ();
1287	sendto (vpn->dnsv4_fd,	1405	sendto (vpn->dnsv4_fd,
1288	send->pkt->at (0), send->pkt->len, 0,	1406	send->pkt->at (0), send->pkt->len, 0,
1289	vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());	1407	vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
1290	}	1408	}
1291		1409
		1410	min_it (next, last_sent + max (poll_interval, send_interval) - ev_now ());
		1411
1292	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)",
1293	poll_interval, send_interval, next - NOW,	1413	poll_interval, send_interval, next - ev_now (),
1294	vpn->dns_sndpq.size (), snddq.size (),	1414	vpn->dns_sndpq.size (), snddq.size (),
1295	rcvpq.size ());	1415	rcvpq.size ());
1296		1416
1297	// TODO: no idea when this happens, but when next < NOW, we have a problem
1298	if (next < NOW + 0.001)
1299	next = NOW + 0.1;
1300
1301	w.start (next);	1417	w.start (next);
1302	}	1418	}
1303		1419
1304	#endif	1420	#endif
1305		1421

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Comparing gvpe/src/vpn_dns.C (file contents): Revision 1.30 by pcg, Mon Mar 14 17:40:01 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 1.30 by pcg, Mon Mar 14 17:40:01 2005 UTC vs.
Revision 1.53 by root, Tue Oct 18 10:54:17 2011 UTC