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

Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.23 by pcg, Sun Mar 6 21:52:15 2005 UTC vs.
Revision 1.52 by root, Sun Mar 6 21:01:37 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 0.5 // optimistic?	70	#define MAX_SEND_INTERVAL 5. // optimistic?
58		71
59	#define MAX_OUTSTANDING 10 // 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 220 // 255 is legal limit, but bind doesn't compress well	75	#define MAX_DOMAIN_SIZE 240 // 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
		453	u8 chksum;
		454	u8 rrtype;
		455	u16 uid; // to make request unique
		456
		457	u8 version;
		458	u8 flags;
		459	u16 max_size;
		460
413	u8 id1, id2, id3, id4;	461	u8 id1, id2, id3, id4;
414	u8 version;	462
415	u8 rrtype;	463	u16 client;
416	u8 flags;
417	u8 def_ttl;	464	u8 def_ttl;
418	u8 rcv_cdc;	465	u8 r0;
419	u8 snd_cdc;
420	u16 max_size;
421	u16 client;
422	u16 uid; // to make request unique
423		466
424	u8 reserved[8];	467	u8 syn_cdc; // cdc en/decoder for syn (A?) requests
		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
		471
		472	u8 r1, r2, r3, r4;
425		473
426	void reset (int clientid);	474	void reset (int clientid);
427	bool valid ();	475	bool valid ();
		476	u8 get_chksum ();
428	};	477	};
429		478
430	int dns_cfg::next_uid;	479	int dns_cfg::next_uid;
431		480
		481	void
432	void dns_cfg::reset (int clientid)	482	dns_cfg::reset (int clientid)
433	{	483	{
		484	// this ID must result in some mixed-case characters in cdc26-encoding
434	id1 = 'G';	485	id1 = 'G';
435	id2 = 'V';	486	id2 = 'V';
436	id3 = 'P';	487	id3 = 'P';
437	id4 = 'E';	488	id4 = 'E';
438		489
439	version = 1;	490	version = 2;
440		491
441	rrtype = RR_TYPE_TXT;	492	rrtype = RR_TYPE_TXT;
442	flags = 0;	493	flags = 0;
443	def_ttl = 1;	494	def_ttl = 0;
444	rcv_cdc = 0;
445	snd_cdc = 62;	495	syn_cdc = 26;
		496	hdr_cdc = 36;
		497	req_cdc = conf.dns_case_preserving ? 62 : 36;
		498	rep_cdc = 0;
446	max_size = ntohs (MAX_PKT_SIZE);	499	max_size = htons (MAX_PKT_SIZE);
447	client = ntohs (clientid);	500	client = htons (clientid);
448	uid = next_uid++;	501	uid = ++next_uid;
449		502
450	memset (reserved, 0, 8);	503	r0 = r1 = r2 = r3 = r4 = 0;
451	}
452		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
453	bool dns_cfg::valid ()	526	dns_cfg::valid ()
454	{	527	{
		528	// although the protocol itself allows for some configurability,
		529	// only the following encoding/decoding settings are implemented.
455	return id1 == 'G'	530	return id1 == 'G'
456	&& id2 == 'V'	531	&& id2 == 'V'
457	&& id3 == 'P'	532	&& id3 == 'P'
458	&& id4 == 'E'	533	&& id4 == 'E'
459	&& version == 1	534	&& version == 2
460	&& flags == 0
461	&& rcv_cdc == 0
462	&& snd_cdc == 62	535	&& syn_cdc == 26
463	&& max_size == ntohs (MAX_PKT_SIZE);	536	&& hdr_cdc == 36
		537	&& (req_cdc == 36 \|\| req_cdc == 62)
		538	&& rep_cdc == 0
		539	&& chksum == get_chksum ();
464	}	540	}
465		541
466	struct dns_packet : net_packet	542	struct dns_packet : net_packet
467	{	543	{
468	u16 id;	544	u16 id;
469	u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4	545	u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4
470	u16 qdcount, ancount, nscount, arcount;	546	u16 qdcount, ancount, nscount, arcount;
471		547
472	u8 data[MAXSIZE - 6 * 2];	548	u8 data [MAXSIZE - 6 * 2];
473		549
474	int decode_label (char *data, int size, int &offs);	550	int decode_label (char *data, int size, int &offs);
475	};	551	};
476		552
		553	int
477	int dns_packet::decode_label (char *data, int size, int &offs)	554	dns_packet::decode_label (char *data, int size, int &offs)
478	{	555	{
479	char *orig = data;	556	char *orig = data;
480		557
481	memset (data, 0, size);	558	memset (data, 0, size);
482		559
…		…
508	return data - orig;	585	return data - orig;
509	}	586	}
510		587
511	/////////////////////////////////////////////////////////////////////////////	588	/////////////////////////////////////////////////////////////////////////////
512		589
		590	static
		591	u16 next_id ()
		592	{
513	static u16 dns_id = 0; // TODO: should be per-vpn	593	static u16 dns_id = 0; // TODO: should be per-vpn
514		594
515	static u16 next_id ()
516	{
517	if (!dns_id)	595	if (!dns_id)
518	dns_id = time (0);	596	dns_id = time (0);
519		597
520	// the simplest lsfr with periodicity 65535 i could find	598	// the simplest lsfr with periodicity 65535 i could find
521	dns_id = (dns_id << 1)	599	dns_id = (dns_id << 1)
…		…
536	struct vpn *vpn;	614	struct vpn *vpn;
537		615
538	dns_cfg cfg;	616	dns_cfg cfg;
539		617
540	bool established;	618	bool established;
		619	const basecoder *cdc;
541		620
542	tstamp last_received;	621	tstamp last_received;
543	tstamp last_sent;	622	tstamp last_sent;
544	double last_latency;	623	double min_latency;
545	double poll_interval, send_interval;	624	double poll_interval, send_interval;
546		625
547	vector<dns_rcv *> rcvpq;	626	vector<dns_rcv *> rcvpq;
548		627
549	byte_stream rcvdq; int rcvseq;	628	byte_stream rcvdq; int rcvseq; int repseq;
550	byte_stream snddq; int sndseq;	629	byte_stream snddq; int sndseq;
551		630
552	void time_cb (time_watcher &w); time_watcher tw;	631	inline void time_cb (ev::timer &w, int revents); ev::timer tw;
553	void receive_rep (dns_rcv *r);	632	void receive_rep (dns_rcv *r);
		633
		634	void reset (); // quite like tcp RST
		635	void set_cfg (); // to be called after any cfg changes
554		636
555	dns_connection (connection *c);	637	dns_connection (connection *c);
556	~dns_connection ();	638	~dns_connection ();
557	};	639	};
558		640
…		…
576	: dns (dns)	658	: dns (dns)
577	{	659	{
578	timeout = 0;	660	timeout = 0;
579	retry = 0;	661	retry = 0;
580	seqno = 0;	662	seqno = 0;
581	sent = NOW;	663	sent = ev_now ();
582	stdhdr = false;	664	stdhdr = false;
583		665
584	pkt = new dns_packet;	666	pkt = new dns_packet;
585		667
586	pkt->id = next_id ();	668	pkt->id = next_id ();
…		…
589	dns_snd::~dns_snd ()	671	dns_snd::~dns_snd ()
590	{	672	{
591	delete pkt;	673	delete pkt;
592	}	674	}
593		675
		676	static void
594	static void append_domain (dns_packet &pkt, int &offs, const char *domain)	677	append_domain (dns_packet &pkt, int &offs, const char *domain)
595	{	678	{
596	// add tunnel domain	679	// add tunnel domain
597	for (;;)	680	for (;;)
598	{	681	{
599	const char *end = strchr (domain, '.');	682	const char *end = strchr (domain, '.');
…		…
612		695
613	domain = end + 1;	696	domain = end + 1;
614	}	697	}
615	}	698	}
616		699
		700	void
617	void dns_snd::gen_stream_req (int seqno, byte_stream &stream)	701	dns_snd::gen_stream_req (int seqno, byte_stream &stream)
618	{	702	{
619	stdhdr = true;	703	stdhdr = true;
620	this->seqno = seqno;	704	this->seqno = seqno;
621		705
622	timeout = NOW + INITIAL_TIMEOUT;	706	timeout = ev_now () + INITIAL_TIMEOUT;
623		707
624	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);	708	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
625	pkt->qdcount = htons (1);	709	pkt->qdcount = htons (1);
626		710
627	int offs = 6*2;	711	int offs = 6*2;
…		…
630	// so we need to have space for 2*MAX_DOMAIN_SIZE + header + extra	714	// so we need to have space for 2*MAX_DOMAIN_SIZE + header + extra
631		715
632	char enc[256], *encp = enc;	716	char enc[256], *encp = enc;
633	encode_header (enc, THISNODE->id, seqno);	717	encode_header (enc, THISNODE->id, seqno);
634		718
635	int datalen = cdc62.decode_len (dlen - (dlen + MAX_LBL_SIZE - 1) / MAX_LBL_SIZE - HDRSIZE);	719	int datalen = dns->cdc->decode_len (dlen - (dlen + MAX_LBL_SIZE - 1) / MAX_LBL_SIZE - HDRSIZE);
636		720
637	if (datalen > stream.size ())	721	if (datalen > stream.size ())
638	datalen = stream.size ();	722	datalen = stream.size ();
639		723
640	int enclen = cdc62.encode (enc + HDRSIZE, stream.begin (), datalen) + HDRSIZE;	724	int enclen = dns->cdc->encode (enc + HDRSIZE, stream.begin (), datalen) + HDRSIZE;
641	stream.remove (datalen);	725	stream.remove (datalen);
642		726
643	while (enclen)	727	while (enclen)
644	{	728	{
645	int lbllen = enclen < MAX_LBL_SIZE ? enclen : MAX_LBL_SIZE;	729	int lbllen = enclen < MAX_LBL_SIZE ? enclen : MAX_LBL_SIZE;
…		…
660	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;	744	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;
661		745
662	pkt->len = offs;	746	pkt->len = offs;
663	}	747	}
664		748
		749	void
665	void dns_snd::gen_syn_req ()	750	dns_snd::gen_syn_req ()
666	{	751	{
667	timeout = NOW + INITIAL_SYN_TIMEOUT;	752	timeout = ev_now () + INITIAL_SYN_TIMEOUT;
668		753
669	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);	754	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
670	pkt->qdcount = htons (1);	755	pkt->qdcount = htons (1);
671		756
672	int offs = 6 * 2;	757	int offs = 6 * 2;
…		…
711	/////////////////////////////////////////////////////////////////////////////	796	/////////////////////////////////////////////////////////////////////////////
712		797
713	dns_connection::dns_connection (connection *c)	798	dns_connection::dns_connection (connection *c)
714	: c (c)	799	: c (c)
715	, rcvdq (MAX_BACKLOG * 2)	800	, rcvdq (MAX_BACKLOG * 2)
716	, snddq (MAX_BACKLOG * 2)	801	, snddq (MAX_BACKLOG)
717	, tw (this, &dns_connection::time_cb)
718	{	802	{
		803	tw.set<dns_connection, &dns_connection::time_cb> (this);
		804
719	vpn = c->vpn;	805	vpn = c->vpn;
720		806
		807	reset ();
		808	}
		809
		810	dns_connection::~dns_connection ()
		811	{
		812	reset ();
		813	}
		814
		815	void
		816	dns_connection::reset ()
		817	{
		818	while (!rcvpq.empty ())
		819	{
		820	delete rcvpq.back ();
		821	rcvpq.pop_back ();
		822	}
		823
		824	for (int i = vpn->dns_sndpq.size (); i--; )
		825	if (vpn->dns_sndpq [i]->dns == this)
		826	{
		827	vpn->dns_sndpq [i] = vpn->dns_sndpq.back ();
		828	vpn->dns_sndpq.pop_back ();
		829	}
		830
721	established = false;	831	established = false;
722		832
723	rcvseq = sndseq = 0;	833	rcvseq = repseq = sndseq = 0;
724		834
725	last_sent = last_received = 0;	835	last_sent = 0;
726	poll_interval = MIN_POLL_INTERVAL;	836	poll_interval = 0.5; // starting here
727	send_interval = 0.5; // starting rate	837	send_interval = 0.5; // starting rate
728	last_latency = INITIAL_TIMEOUT;	838	min_latency = INITIAL_TIMEOUT;
729	}	839	}
730		840
731	dns_connection::~dns_connection ()	841	void
		842	dns_connection::set_cfg ()
732	{	843	{
733	for (vector<dns_rcv *>::iterator i = rcvpq.begin ();	844	cdc = cfg.req_cdc == 36 ? &cdc36 : &cdc62;
734	i != rcvpq.end ();
735	++i)
736	delete *i;
737	}	845	}
738		846
		847	void
739	void dns_connection::receive_rep (dns_rcv *r)	848	dns_connection::receive_rep (dns_rcv *r)
740	{	849	{
741	if (r->datalen)	850	if (r->datalen)
742	{	851	poll_interval = max (poll_interval * (1. / 1.2), MIN_POLL_INTERVAL);
743	last_received = NOW;
744	tw.trigger ();
745
746	poll_interval = send_interval;
747	}
748	else	852	else
749	{	853	poll_interval = min (poll_interval * 1.1, MAX_POLL_INTERVAL);
750	poll_interval *= 1.5;
751	if (poll_interval > MAX_POLL_INTERVAL)
752	poll_interval = MAX_POLL_INTERVAL;
753	}
754		854
755	rcvpq.push_back (r);	855	rcvpq.push_back (r);
756		856
757	redo:	857	redo:
758		858
759	// find next packet	859	// find next packet
760	for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); )	860	for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); )
761	if (SEQNO_EQ (rcvseq, (*i)->seqno))	861	if (SEQNO_EQ (rcvseq, (*i)->seqno))
762	{	862	{
		863	//printf ("seqno eq %x %x\n", rcvseq, (*i)->seqno);//D
763	// enter the packet into our input stream	864	// enter the packet into our input stream
764	r = *i;	865	r = *i;
765		866
766	// remove the oldest packet, look forward, as it's oldest first	867	// remove the oldest packet, look forward, as it's oldest first
767	for (vector<dns_rcv *>::iterator j = rcvpq.begin (); j != rcvpq.end (); ++j)	868	for (vector<dns_rcv *>::iterator j = rcvpq.begin (); j != rcvpq.end (); ++j)
768	if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW))	869	if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW))
769	{	870	{
		871	//printf ("seqno RR %x %x\n", (*j)->seqno, rcvseq - MAX_WINDOW);//D
770	delete *j;	872	delete *j;
771	rcvpq.erase (j);	873	rcvpq.erase (j);
772	break;	874	break;
773	}	875	}
774		876
775	rcvseq = (rcvseq + 1) & SEQNO_MASK;	877	rcvseq = (rcvseq + 1) & SEQNO_MASK;
776		878
777	if (!rcvdq.put (r->data, r->datalen))	879	if (!rcvdq.put (r->data, r->datalen))
778	{	880	{
		881	// MUST never overflow, can be caused by data corruption, TODO
779	slog (L_ERR, "DNS: !rcvdq.put (r->data, r->datalen)");	882	slog (L_CRIT, "DNS: !rcvdq.put (r->data, r->datalen)");
780	abort (); // MUST never overflow, can be caused by data corruption, TODO	883	reset ();
		884	return;
781	}	885	}
782		886
783	while (vpn_packet *pkt = rcvdq.get ())	887	while (vpn_packet *pkt = rcvdq.get ())
784	{	888	{
785	sockinfo si;	889	sockinfo si;
786	si.host = 0x01010101; si.port = htons (c->conf->id); si.prot = PROT_DNSv4;	890	si.host = htonl (c->conf->id); si.port = 0; si.prot = PROT_DNSv4;
787		891
788	vpn->recv_vpn_packet (pkt, si);	892	vpn->recv_vpn_packet (pkt, si);
789
790	delete pkt;	893	delete pkt;
791	}	894	}
792		895
793	// check for further packets	896	// check for further packets
794	goto redo;	897	goto redo;
…		…
805	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);	908	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);
806		909
807	if (0 == (flags & (FLAG_RESPONSE \| FLAG_OP_MASK))	910	if (0 == (flags & (FLAG_RESPONSE \| FLAG_OP_MASK))
808	&& pkt.qdcount == htons (1))	911	&& pkt.qdcount == htons (1))
809	{	912	{
810	char qname[MAXSIZE];	913	char qname [MAXSIZE];
811	int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);	914	int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
812		915
813	u16 qtype = pkt [offs++] << 8; qtype \|= pkt [offs++];	916	u16 qtype = pkt [offs++] << 8; qtype \|= pkt [offs++];
814	u16 qclass = pkt [offs++] << 8; qclass \|= pkt [offs++];	917	u16 qclass = pkt [offs++] << 8; qclass \|= pkt [offs++];
815		918
…		…
822		925
823	int dlen = strlen (THISNODE->domain);	926	int dlen = strlen (THISNODE->domain);
824		927
825	if (qclass == RR_CLASS_IN	928	if (qclass == RR_CLASS_IN
826	&& qlen > dlen + 1	929	&& qlen > dlen + 1
827	&& !memcmp (qname + qlen - dlen - 1, THISNODE->domain, dlen))	930	&& !memcmp (qname + qlen - (dlen + 1), THISNODE->domain, dlen))
828	{	931	{
829	// now generate reply	932	// now generate reply
830	pkt.ancount = htons (1); // one answer RR	933	pkt.ancount = htons (1); // one answer RR
831	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_OK);	934	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_OK);
832		935
…		…
837	{	940	{
838	// correct class, domain: parse	941	// correct class, domain: parse
839	int client, seqno;	942	int client, seqno;
840	decode_header (qname, client, seqno);	943	decode_header (qname, client, seqno);
841		944
842	u8 data[MAXSIZE];
843	int datalen = cdc62.decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE));
844
845	if (0 < client && client <= conns.size ())	945	if (0 < client && client <= conns.size ())
846	{	946	{
847	connection *c = conns [client - 1];	947	connection *c = conns [client - 1];
848	dns_connection *dns = c->dns;	948	dns_connection *dns = c->dns;
849	dns_rcv *rcv;	949	dns_rcv *rcv;
850	bool in_seq;
851		950
852	if (dns)	951	if (dns)
853	{	952	{
		953	u8 data[MAXSIZE];
		954	int datalen = dns->cdc->decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE));
		955
854	for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); )	956	for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); )
855	if (SEQNO_EQ ((*i)->seqno, seqno))	957	if (SEQNO_EQ ((*i)->seqno, seqno))
856	{	958	{
857	// already seen that request: simply reply with the cached reply	959	// already seen that request: simply reply with the cached reply
858	dns_rcv r = i;	960	dns_rcv r = i;
…		…
866	memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len);	968	memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len);
867		969
868	goto duplicate_request;	970	goto duplicate_request;
869	}	971	}
870		972
871	in_seq = dns->rcvseq == seqno;
872
873	// new packet, queue	973	// new packet, queue
874	rcv = new dns_rcv (seqno, data, datalen);	974	rcv = new dns_rcv (seqno, data, datalen);
875	dns->receive_rep (rcv);	975	dns->receive_rep (rcv);
876	}	976	}
877		977
…		…
884	pkt [offs++] = 0; pkt [offs++] = 0;	984	pkt [offs++] = 0; pkt [offs++] = 0;
885	pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL	985	pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL
886		986
887	int rdlen_offs = offs += 2;	987	int rdlen_offs = offs += 2;
888		988
889	int dlen = (dns ? ntohs (dns->cfg.max_size) : MAX_PKT_SIZE) - offs;
890	// bind doesn't compress well, so reduce further by one label length
891	dlen -= qlen;
892
893	if (dns)	989	if (dns)
894	{	990	{
		991	int dlen = ntohs (dns->cfg.max_size) - offs;
		992
		993	// bind doesn't compress well, so reduce further by one label length
		994	dlen -= qlen;
		995
895	// only put data into in-order sequence packets, if	996	// only put data into in-order sequence packets, if
896	// we receive out-of-order packets we generate empty	997	// we receive out-of-order packets we generate empty
897	// replies	998	// replies
898	while (dlen > 1 && !dns->snddq.empty () && in_seq)	999	//printf ("%d - %d & %x (=%d) < %d\n", seqno, dns->repseq, SEQNO_MASK, (seqno - dns->repseq) & SEQNO_MASK, MAX_WINDOW);//D
		1000	if (((seqno - dns->repseq) & SEQNO_MASK) <= MAX_WINDOW)
899	{	1001	{
		1002	dns->repseq = seqno;
		1003
		1004	while (dlen > 1 && !dns->snddq.empty ())
		1005	{
900	int txtlen = dlen <= 255 ? dlen - 1 : 255;	1006	int txtlen = dlen <= 255 ? dlen - 1 : 255;
901		1007
902	if (txtlen > dns->snddq.size ())	1008	if (txtlen > dns->snddq.size ())
903	txtlen = dns->snddq.size ();	1009	txtlen = dns->snddq.size ();
904		1010
905	pkt[offs++] = txtlen;	1011	pkt[offs++] = txtlen;
906	memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);	1012	memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
907	offs += txtlen;	1013	offs += txtlen;
908	dns->snddq.remove (txtlen);	1014	dns->snddq.remove (txtlen);
909		1015
910	dlen -= txtlen + 1;	1016	dlen -= txtlen + 1;
		1017	}
911	}	1018	}
912		1019
913	// avoid empty TXT rdata	1020	// avoid completely empty TXT rdata
914	if (offs == rdlen_offs)	1021	if (offs == rdlen_offs)
915	pkt[offs++] = 0;	1022	pkt[offs++] = 0;
916		1023
917	slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());	1024	slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
918	}	1025	}
…		…
954	pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class	1061	pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
955	pkt [offs++] = 0; pkt [offs++] = 0;	1062	pkt [offs++] = 0; pkt [offs++] = 0;
956	pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL	1063	pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL
957	pkt [offs++] = 0; pkt [offs++] = 4; // rdlength	1064	pkt [offs++] = 0; pkt [offs++] = 4; // rdlength
958		1065
959	slog (L_INFO, _("DNS: client %d tries to connect"), client);
960
961	pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;	1066	pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
962	pkt [offs++] = CMD_IP_REJ;	1067	pkt [offs++] = CMD_IP_REJ;
963		1068
964	if (0 < client && client <= conns.size ())	1069	if (0 < client && client <= conns.size ())
965	{	1070	{
966	connection *c = conns [client - 1];	1071	connection *c = conns [client - 1];
967		1072
968	if (cfg.valid ())	1073	if (cfg.valid ())
969	{	1074	{
970	pkt [offs - 1] = CMD_IP_SYN;	1075	slog (L_INFO, _("DNS: client %d connects (version %d, req_cdc %d)"), client, cfg.version, cfg.req_cdc);
		1076
		1077	// check for any encoding mismatches - hints at a case problem
		1078	char qname2 [MAX_ENC_LEN];
		1079	cdc26.encode (qname2, (u8 *)&cfg, sizeof (dns_cfg));
971		1080
972	delete c->dns;	1081	delete c->dns;
		1082
		1083	pkt [offs - 1] = memcmp (qname, qname2, cdc26.encode_len (sizeof (dns_cfg)))
		1084	? CMD_IP_CSE : CMD_IP_SYN;
		1085
973	c->dns = new dns_connection (c);	1086	c->dns = new dns_connection (c);
974	c->dns->cfg = cfg;	1087	c->dns->cfg = cfg;
		1088	c->dns->set_cfg ();
975	}	1089	}
976	}	1090	}
977	}	1091	}
978	}	1092	}
979		1093
…		…
998	{	1112	{
999	dns_connection dns = (i)->dns;	1113	dns_connection dns = (i)->dns;
1000	connection *c = dns->c;	1114	connection *c = dns->c;
1001	int seqno = (*i)->seqno;	1115	int seqno = (*i)->seqno;
1002	u8 data[MAXSIZE], *datap = data;	1116	u8 data[MAXSIZE], *datap = data;
		1117	//printf ("rcv pkt %x\n", seqno);//D
1003		1118
1004	if ((*i)->retry)	1119	if ((*i)->retry)
1005	{	1120	{
1006	dns->send_interval *= 1.01;	1121	dns->send_interval *= 1.01;
1007	if (dns->send_interval > MAX_SEND_INTERVAL)	1122	if (dns->send_interval > MAX_SEND_INTERVAL)
1008	dns->send_interval = MAX_SEND_INTERVAL;	1123	dns->send_interval = MAX_SEND_INTERVAL;
1009	}	1124	}
1010	else	1125	else
1011	{	1126	{
1012	#if 1	1127	#if 0
1013	dns->send_interval *= 0.999;	1128	dns->send_interval *= 0.999;
1014	#endif	1129	#endif
1015	if (dns->send_interval < MIN_SEND_INTERVAL)
1016	dns->send_interval = MIN_SEND_INTERVAL;
1017
1018	// the latency surely puts an upper bound on	1130	// the latency surely puts an upper bound on
1019	// the minimum send interval	1131	// the minimum send interval
1020	double latency = NOW - (*i)->sent;	1132	double latency = ev_now () - (*i)->sent;
		1133
		1134	if (latency < dns->min_latency)
1021	dns->last_latency = latency;	1135	dns->min_latency = latency;
1022		1136
1023	if (dns->send_interval > latency)	1137	if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor)
		1138	dns->send_interval = dns->min_latency * conf.dns_overlap_factor;
		1139
		1140	if (dns->send_interval < conf.dns_send_interval)
1024	dns->send_interval = latency;	1141	dns->send_interval = conf.dns_send_interval;
1025	}	1142	}
1026		1143
1027	delete *i;	1144	delete *i;
1028	dns_sndpq.erase (i);	1145	dns_sndpq.erase (i);
1029		1146
…		…
1047	ttl \|= pkt [offs++] << 16;	1164	ttl \|= pkt [offs++] << 16;
1048	ttl \|= pkt [offs++] << 8;	1165	ttl \|= pkt [offs++] << 8;
1049	ttl \|= pkt [offs++];	1166	ttl \|= pkt [offs++];
1050	u16 rdlen = pkt [offs++] << 8; rdlen \|= pkt [offs++];	1167	u16 rdlen = pkt [offs++] << 8; rdlen \|= pkt [offs++];
1051		1168
1052	if (qtype == RR_TYPE_NULL \|\| qtype == RR_TYPE_TXT)	1169	if (qtype == RR_TYPE_NULL \|\| qtype == RR_TYPE_TXT \|\| qtype == dns->cfg.rrtype)
1053	{	1170	{
1054	if (rdlen <= MAXSIZE - offs)	1171	if (rdlen <= MAXSIZE - offs)
1055	{	1172	{
1056	// decode bytes, finally	1173	// decode bytes, finally
1057		1174
…		…
1083	{	1200	{
1084	slog (L_TRACE, _("DNS: got tunnel meta command %02x"), ip [3]);	1201	slog (L_TRACE, _("DNS: got tunnel meta command %02x"), ip [3]);
1085		1202
1086	if (ip [3] == CMD_IP_RST)	1203	if (ip [3] == CMD_IP_RST)
1087	{	1204	{
1088	slog (L_DEBUG, _("DNS: got tunnel RST request"));	1205	slog (L_DEBUG, _("DNS: got tunnel RST request."));
1089		1206
1090	delete dns; c->dns = 0;	1207	dns->reset ();
1091
1092	return;	1208	return;
1093	}	1209	}
1094	else if (ip [3] == CMD_IP_SYN)	1210	else if (ip [3] == CMD_IP_SYN)
1095	{	1211	{
1096	slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us."));	1212	slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us."));
1097	dns->established = true;	1213	dns->established = true;
1098	}	1214	}
		1215	else if (ip [3] == CMD_IP_CSE)
		1216	{
		1217	if (conf.dns_case_preserving)
		1218	{
		1219	slog (L_INFO, _("DNS: got tunnel CSE reply, globally downgrading to case-insensitive protocol."));
		1220	conf.dns_case_preserving = false;
		1221	dns->reset ();
		1222	return;
		1223	}
		1224	else
		1225	{
		1226	slog (L_DEBUG, _("DNS: got tunnel CSE reply, server likes us."));
		1227	dns->established = true;
		1228	}
		1229	}
1099	else if (ip [3] == CMD_IP_REJ)	1230	else if (ip [3] == CMD_IP_REJ)
1100	{	1231	{
1101	slog (L_DEBUG, _("DNS: got tunnel REJ reply, server does not like us, aborting."));	1232	slog (L_ERR, _("DNS: got tunnel REJ reply, server does not like us."));
1102	abort ();	1233	dns->tw.start (60.);
1103	}	1234	}
1104	else	1235	else
		1236	{
1105	slog (L_INFO, _("DNS: got unknown meta command %02x"), ip [3]);	1237	slog (L_INFO, _("DNS: got unknown meta command %02x"), ip [3]);
		1238	dns->tw.start (60.);
		1239	}
1106	}	1240	}
1107	else	1241	else
1108	slog (L_INFO, _("DNS: got spurious a record %d.%d.%d.%d"),	1242	slog (L_INFO, _("DNS: got spurious a record %d.%d.%d.%d"),
1109	ip [0], ip [1], ip [2], ip [3]);	1243	ip [0], ip [1], ip [2], ip [3]);
1110		1244
…		…
1134	break;	1268	break;
1135	}	1269	}
1136	}	1270	}
1137		1271
1138	void	1272	void
1139	vpn::dnsv4_ev (io_watcher &w, short revents)	1273	vpn::dnsv4_ev (ev::io &w, int revents)
1140	{	1274	{
1141	if (revents & EVENT_READ)	1275	if (revents & EV_READ)
1142	{	1276	{
1143	dns_packet *pkt = new dns_packet;	1277	dns_packet *pkt = new dns_packet;
1144	struct sockaddr_in sa;	1278	struct sockaddr_in sa;
1145	socklen_t sa_len = sizeof (sa);	1279	socklen_t sa_len = sizeof (sa);
1146		1280
1147	pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len);	1281	pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len);
1148		1282
1149	if (pkt->len > 0)	1283	if (pkt->len > 0)
1150	{	1284	{
1151	if (THISNODE->dns_port)	1285	if (ntohs (pkt->flags) & FLAG_RESPONSE)
		1286	dnsv4_client (*pkt);
		1287	else
1152	{	1288	{
1153	dnsv4_server (*pkt);	1289	dnsv4_server (*pkt);
1154	sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len);	1290	sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len);
1155	}	1291	}
1156	else
1157	dnsv4_client (*pkt);
1158		1292
1159	delete pkt;	1293	delete pkt;
1160	}	1294	}
1161	}	1295	}
1162	}	1296	}
1163		1297
1164	bool	1298	bool
1165	vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)	1299	vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
1166	{	1300	{
1167	int client = ntohs (si.port);	1301	int client = ntohl (si.host);
1168		1302
1169	assert (0 < client && client <= conns.size ());	1303	assert (0 < client && client <= conns.size ());
1170		1304
1171	connection *c = conns [client - 1];	1305	connection *c = conns [client - 1];
1172		1306
1173	if (!c->dns)	1307	if (!c->dns)
1174	c->dns = new dns_connection (c);	1308	c->dns = new dns_connection (c);
1175		1309
1176	if (!c->dns->snddq.put (pkt))	1310	if (c->dns->snddq.put (pkt))
1177	return false;	1311	{
		1312	min_it (c->dns->poll_interval, 0.25);
		1313	c->dns->tw ();
		1314	}
1178		1315
1179	c->dns->tw.trigger ();	1316	// always return true even if the buffer overflows
1180
1181	return true;	1317	return true;
1182	}	1318	}
1183		1319
1184	void	1320	void
1185	connection::dnsv4_reset_connection ()	1321	dns_connection::time_cb (ev::timer &w, int revents)
1186	{
1187	//delete dns; dns = 0; //TODO
1188	}
1189
1190	#define NEXT(w) do { if (next > (w)) next = w; } while (0)
1191
1192	void
1193	dns_connection::time_cb (time_watcher &w)
1194	{	1322	{
1195	// servers have to be polled	1323	// servers have to be polled
1196	if (THISNODE->dns_port)	1324	if (THISNODE->dns_port)
1197	return;	1325	return;
1198		1326
1199	// check for timeouts and (re)transmit	1327	// check for timeouts and (re)transmit
1200	tstamp next = NOW + poll_interval;	1328	tstamp next = 86400 * 365;
1201	dns_snd *send = 0;	1329	dns_snd *send = 0;
1202		1330
1203	for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin ();	1331	for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin ();
1204	i != vpn->dns_sndpq.end ();	1332	i != vpn->dns_sndpq.end ();
1205	++i)	1333	++i)
1206	{	1334	{
1207	dns_snd r = i;	1335	dns_snd r = i;
1208		1336
1209	if (r->timeout <= NOW)	1337	if (r->timeout <= ev_now ())
1210	{	1338	{
1211	if (!send)	1339	if (!send)
1212	{	1340	{
1213	send = r;	1341	send = r;
1214		1342
1215	r->retry++;	1343	r->retry++;
1216	r->timeout = NOW + (r->retry * last_latency * 8.);	1344	r->timeout = ev_now () + r->retry * min_latency * conf.dns_timeout_factor;
		1345	//printf ("RETRY %x (%d, %f)\n", r->seqno, r->retry, r->timeout - ev_now ());//D
1217		1346
1218	// the following code changes the query section a bit, forcing	1347	// the following code changes the query section a bit, forcing
1219	// the forwarder to generate a new request	1348	// the forwarder to generate a new request
1220	if (r->stdhdr)	1349	if (r->stdhdr)
1221	{
1222	//printf ("reencoded header for ID %d retry %d:%d:%d\n", htons (r->pkt->id), THISNODE->id, r->seqno, r->retry);printf ("reencoded header for ID %d retry %d:%d:%d\n", htons (r->pkt->id), THISNODE->id, r->seqno, r->retry);
1223	//encode_header ((char )r->pkt->at (6 2 + 1), THISNODE->id, r->seqno, r->retry);	1350	encode_header ((char )r->pkt->at (6 2 + 1), THISNODE->id, r->seqno, r->retry);
1224	}
1225	}	1351	}
1226	}	1352	}
1227	else	1353	else
1228	NEXT (r->timeout);	1354	min_it (next, r->timeout - ev_now ());
1229	}
1230
1231	if (last_sent + send_interval <= NOW)
1232	{	1355	}
		1356
1233	if (!send)	1357	if (!send)
		1358	{
		1359	// generate a new packet, if wise
		1360
		1361	if (!established)
1234	{	1362	{
1235	// generate a new packet, if wise	1363	if (vpn->dns_sndpq.empty ())
1236
1237	if (!established)
1238	{	1364	{
1239	if (vpn->dns_sndpq.empty ())
1240	{
1241	send = new dns_snd (this);	1365	send = new dns_snd (this);
1242		1366
1243	cfg.reset (THISNODE->id);	1367	cfg.reset (THISNODE->id);
		1368	set_cfg ();
1244	send->gen_syn_req ();	1369	send->gen_syn_req ();
1245	}
1246	}	1370	}
1247	else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING	1371	}
		1372	else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding
1248	&& !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))	1373	&& !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
		1374	{
		1375	if (last_sent + send_interval <= ev_now ())
1249	{	1376	{
1250	//printf ("sending data request etc.\n"); //D	1377	//printf ("sending data request etc.\n"); //D
1251	if (!snddq.empty ())	1378	if (!snddq.empty ())
1252	{
1253	poll_interval = send_interval;
1254	NEXT (NOW + send_interval);	1379	min_it (next, send_interval);
1255	}
1256		1380
1257	send = new dns_snd (this);	1381	send = new dns_snd (this);
1258	send->gen_stream_req (sndseq, snddq);	1382	send->gen_stream_req (sndseq, snddq);
1259	send->timeout = NOW + last_latency * 8.;	1383	send->timeout = ev_now () + min_latency * conf.dns_timeout_factor;
		1384	//printf ("SEND %x (%f)\n", send->seqno, send->timeout - ev_now (), min_latency, conf.dns_timeout_factor);//D
1260		1385
1261	sndseq = (sndseq + 1) & SEQNO_MASK;	1386	sndseq = (sndseq + 1) & SEQNO_MASK;
1262	}	1387	}
1263		1388	else
1264	if (send)	1389	min_it (next, last_sent + send_interval - ev_now ());
1265	vpn->dns_sndpq.push_back (send);
1266	}	1390	}
1267		1391
1268	if (send)	1392	if (send)
1269	{	1393	vpn->dns_sndpq.push_back (send);
1270	last_sent = NOW;	1394	}
		1395
		1396	if (send)
		1397	{
		1398	last_sent = ev_now ();
1271	sendto (vpn->dnsv4_fd,	1399	sendto (vpn->dnsv4_fd,
1272	send->pkt->at (0), send->pkt->len, 0,	1400	send->pkt->at (0), send->pkt->len, 0,
1273	vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());	1401	vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
1274	}
1275	}	1402	}
1276	else
1277	NEXT (last_sent + send_interval);
1278		1403
		1404	min_it (next, last_sent + max (poll_interval, send_interval) - ev_now ());
		1405
1279	slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d)",	1406	slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)",
1280	poll_interval, send_interval, next - NOW,	1407	poll_interval, send_interval, next - ev_now (),
1281	vpn->dns_sndpq.size (), snddq.size ());	1408	vpn->dns_sndpq.size (), snddq.size (),
1282		1409	rcvpq.size ());
1283	// TODO: no idea when this happens, but when next < NOW, we have a problem
1284	if (next < NOW + 0.0001)
1285	next = NOW + 0.1;
1286		1410
1287	w.start (next);	1411	w.start (next);
1288	}	1412	}
1289		1413
1290	#endif	1414	#endif

Diff Legend

-–
+Removed lines
-+
+Added lines
-<
+Changed lines
->
+Changed lines

Comparing gvpe/src/vpn_dns.C (file contents): Revision 1.23 by pcg, Sun Mar 6 21:52:15 2005 UTC vs. Revision 1.52 by root, Sun Mar 6 21:01:37 2011 UTC

Diff Legend

Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.23 by pcg, Sun Mar 6 21:52:15 2005 UTC vs.
Revision 1.52 by root, Sun Mar 6 21:01:37 2011 UTC