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

Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.8 by pcg, Fri Mar 4 03:43:09 2005 UTC vs.
Revision 1.24 by pcg, Mon Mar 7 01:31:26 2005 UTC

…		…
25		25
26	// dns processing is EXTREMELY ugly. For obvious(?) reasons.	26	// dns processing is EXTREMELY ugly. For obvious(?) reasons.
27	// it's a hack, use only in emergency situations please.	27	// it's a hack, use only in emergency situations please.
28		28
29	#include <cstring>	29	#include <cstring>
		30	#include <cassert>
30		31
31	#include <sys/types.h>	32	#include <sys/types.h>
32	#include <sys/socket.h>	33	#include <sys/socket.h>
33	#include <sys/wait.h>	34	#include <sys/wait.h>
34	#include <sys/uio.h>	35	#include <sys/uio.h>
…		…
43		44
44	#include "netcompat.h"	45	#include "netcompat.h"
45		46
46	#include "vpn.h"	47	#include "vpn.h"
47		48
48	#define MIN_RETRY 1.	49	#define MIN_POLL_INTERVAL .02 // how often to poll minimally when the server has data
49	#define MAX_RETRY 60.	50	#define MAX_POLL_INTERVAL 6. // how often to poll minimally when the server has no data
		51	#define ACTIVITY_INTERVAL 5.
50		52
		53	#define INITIAL_TIMEOUT 0.1 // retry timeouts
		54	#define INITIAL_SYN_TIMEOUT 10. // retry timeout for initial syn
		55
		56	#define MIN_SEND_INTERVAL 0.01 // wait at least this time between sending requests
		57	#define MAX_SEND_INTERVAL 0.5 // optimistic?
		58
51	#define MAX_OUTSTANDING 400 // max. outstanding requests	59	#define MAX_OUTSTANDING 10 // max. outstanding requests
52	#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING	60	#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog
53	#define MAX_RATE 10000 // requests/s
54	#define MAX_BACKLOG (10*1024) // size of protocol backlog, must be > MAXSIZE	61	#define MAX_BACKLOG (100*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE
55		62
56	#define MAX_DOMAIN_SIZE 220 // 255 is legal limit, but bind doesn't compress well	63	#define MAX_DOMAIN_SIZE 220 // 255 is legal limit, but bind doesn't compress well
57	// 240 leaves about 4 bytes of server reply data	64	// 240 leaves about 4 bytes of server reply data
58	// every two request byte sless give room for one reply byte	65	// every two request bytes less give room for one reply byte
59		66
60	// seqno has 12 bits (3 bytes a 4 bits in the header)
61	#define SEQNO_MASK 0x7fff	67	#define SEQNO_MASK 0x3fff
62	#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )	68	#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )
63		69
64	#define MAX_LBL_SIZE 63	70	#define MAX_LBL_SIZE 63
65	#define MAX_PKT_SIZE 512	71	#define MAX_PKT_SIZE 512
66		72
		73	#define RR_TYPE_A 1
		74	#define RR_TYPE_NULL 10
67	#define RR_TYPE_TXT 16	75	#define RR_TYPE_TXT 16
68	#define RR_TYPE_ANY 255	76	#define RR_TYPE_ANY 255
		77
69	#define RR_CLASS_IN 1	78	#define RR_CLASS_IN 1
		79
		80	#define CMD_IP_1 207
		81	#define CMD_IP_2 46
		82	#define CMD_IP_3 236
		83	#define CMD_IP_RST 29
		84	#define CMD_IP_SYN 113
		85	#define CMD_IP_REJ 32
70		86
71	// works for cmaps up to 255 (not 256!)	87	// works for cmaps up to 255 (not 256!)
72	struct charmap	88	struct charmap
73	{	89	{
74	enum { INVALID = (u8)255 };	90	enum { INVALID = (u8)255 };
…		…
154	return dec_len [len];	170	return dec_len [len];
155	}	171	}
156		172
157	unsigned int basecoder::encode (char dst, u8 src, unsigned int len)	173	unsigned int basecoder::encode (char dst, u8 src, unsigned int len)
158	{	174	{
159	if (!len)	175	if (!len \|\| len > MAX_DEC_LEN)
160	return 0;	176	return 0;
161		177
162	int elen = encode_len (len);	178	int elen = encode_len (len);
163		179
164	mp_limb_t m [MAX_LIMBS];	180	mp_limb_t m [MAX_LIMBS];
…		…
183	return elen;	199	return elen;
184	}	200	}
185		201
186	unsigned int basecoder::decode (u8 dst, char src, unsigned int len)	202	unsigned int basecoder::decode (u8 dst, char src, unsigned int len)
187	{	203	{
188	if (!len)	204	if (!len \|\| len > MAX_ENC_LEN)
189	return 0;	205	return 0;
190		206
191	u8 src_ [MAX_ENC_LEN];	207	u8 src_ [MAX_ENC_LEN];
192	unsigned int elen = 0;	208	unsigned int elen = 0;
193		209
…		…
240	}	256	}
241	abort ();	257	abort ();
242	}	258	}
243	#endif	259	#endif
244		260
245	// the following sequence has been crafted to	261	//static basecoder cdc64 ("_dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI-");
246	// a) look somewhat random
247	// b) the even (and odd) indices never share the same character as upper/lowercase
248	// the "_" is not valid but widely accepted (all octets should be supported, but let's be conservative)
249	// the other sequences are obviously derived
250	//static basecoder cdc63 ("_dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI");	262	//static basecoder cdc63 ("_dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI");
251	static basecoder cdc62 ("dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI");	263	static basecoder cdc62 ("dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI");
252	//static basecoder cdc36 ("dphzr06qmjkb34tsvl81xaef92wgyo57ucni"); // unused as of yet	264	//static basecoder cdc36 ("dphzr06qmjkb34tsvl81xaef92wgyo57ucni"); // unused as of yet
253	static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO");	265	static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO");
254		266
255	/////////////////////////////////////////////////////////////////////////////	267	/////////////////////////////////////////////////////////////////////////////
256		268
257	#define HDRSIZE 6	269	#define HDRSIZE 6
258		270
259	inline void encode_header (char *data, int clientid, int seqno)	271	inline void encode_header (char *data, int clientid, int seqno, int retry = 0)
260	{	272	{
261	u8 hdr[3] = { clientid, seqno >> 8, seqno };	273	seqno &= SEQNO_MASK;
		274
		275	u8 hdr[3] = {
		276	clientid,
		277	(seqno >> 8) \| (retry << 6),
		278	seqno,
		279	};
262		280
263	assert (clientid < 256);	281	assert (clientid < 256);
264		282
265	cdc26.encode (data, hdr, 3);	283	cdc26.encode (data, hdr, 3);
266	}	284	}
…		…
269	{	287	{
270	u8 hdr[3];	288	u8 hdr[3];
271		289
272	cdc26.decode (hdr, data, HDRSIZE);	290	cdc26.decode (hdr, data, HDRSIZE);
273		291
274	printf ("DEC %02x %02x %02x %02x\n", hdr[0], hdr[1], hdr[2], hdr[3]);
275
276	clientid = hdr[0];	292	clientid = hdr[0];
277	seqno = (hdr[1] << 8) \| hdr[2];	293	seqno = ((hdr[1] << 8) \| hdr[2]) & SEQNO_MASK;
278	}	294	}
279		295
280	/////////////////////////////////////////////////////////////////////////////	296	/////////////////////////////////////////////////////////////////////////////
281		297
282	struct byte_stream	298	struct byte_stream
…		…
311	}	327	}
312		328
313	void byte_stream::remove (int count)	329	void byte_stream::remove (int count)
314	{	330	{
315	if (count > fill)	331	if (count > fill)
316	abort ();	332	assert (count <= fill);
317		333
318	memmove (data, data + count, fill -= count);	334	memmove (data, data + count, fill -= count);
319	}	335	}
320		336
321	bool byte_stream::put (u8 *data, unsigned int datalen)	337	bool byte_stream::put (u8 *data, unsigned int datalen)
…		…
334	return false;	350	return false;
335		351
336	data [fill++] = pkt->len >> 8;	352	data [fill++] = pkt->len >> 8;
337	data [fill++] = pkt->len;	353	data [fill++] = pkt->len;
338		354
339	memcpy (data + fill, &((*pkt)[0]), pkt->len); fill += pkt->len;	355	memcpy (data + fill, pkt->at (0), pkt->len); fill += pkt->len;
340		356
341	return true;	357	return true;
342	}	358	}
343		359
344	vpn_packet *byte_stream::get ()	360	vpn_packet *byte_stream::get ()
345	{	361	{
		362	unsigned int len;
		363
		364	for (;;)
		365	{
346	int len = (data [0] << 8) \| data [1];	366	len = (data [0] << 8) \| data [1];
347		367
348	if (len > MAXSIZE && fill >= 2)	368	if (len <= MAXSIZE \|\| fill < 2)
349	abort (); // TODO handle this gracefully, connection reset	369	break;
350		370
		371	// TODO: handle this better than skipping, e.g. by reset
		372	slog (L_DEBUG, _("DNS: corrupted packet stream skipping a byte..."));
		373	remove (1);
		374	}
		375
351	if (fill < len + 2)	376	if (fill < len + 2)
352	return 0;	377	return 0;
353		378
354	vpn_packet *pkt = new vpn_packet;	379	vpn_packet *pkt = new vpn_packet;
355		380
356	pkt->len = len;	381	pkt->len = len;
357	memcpy (&((*pkt)[0]), data + 2, len);	382	memcpy (pkt->at (0), data + 2, len);
358	remove (len + 2);	383	remove (len + 2);
359		384
360	return pkt;	385	return pkt;
361	}	386	}
362		387
363	/////////////////////////////////////////////////////////////////////////////	388	/////////////////////////////////////////////////////////////////////////////
364		389
365	#define FLAG_QUERY ( 0 << 15)	390	#define FLAG_QUERY ( 0 << 15)
366	#define FLAG_RESPONSE ( 1 << 15)	391	#define FLAG_RESPONSE ( 1 << 15)
367	#define FLAG_OP_MASK (15 << 14)	392	#define FLAG_OP_MASK (15 << 11)
368	#define FLAG_OP_QUERY ( 0 << 11)	393	#define FLAG_OP_QUERY ( 0 << 11)
369	#define FLAG_AA ( 1 << 10)	394	#define FLAG_AA ( 1 << 10)
370	#define FLAG_TC ( 1 << 9)	395	#define FLAG_TC ( 1 << 9)
371	#define FLAG_RD ( 1 << 8)	396	#define FLAG_RD ( 1 << 8)
372	#define FLAG_RA ( 1 << 7)	397	#define FLAG_RA ( 1 << 7)
…		…
379	#define FLAG_RCODE_REFUSED ( 5 << 0)	404	#define FLAG_RCODE_REFUSED ( 5 << 0)
380		405
381	#define DEFAULT_CLIENT_FLAGS (FLAG_QUERY \| FLAG_OP_QUERY \| FLAG_RD)	406	#define DEFAULT_CLIENT_FLAGS (FLAG_QUERY \| FLAG_OP_QUERY \| FLAG_RD)
382	#define DEFAULT_SERVER_FLAGS (FLAG_RESPONSE \| FLAG_OP_QUERY \| FLAG_AA \| FLAG_RD \| FLAG_RA)	407	#define DEFAULT_SERVER_FLAGS (FLAG_RESPONSE \| FLAG_OP_QUERY \| FLAG_AA \| FLAG_RD \| FLAG_RA)
383		408
		409	struct dns_cfg
		410	{
		411	static int next_uid;
		412
		413	u8 id1, id2, id3, id4;
		414
		415	u8 version;
		416	u8 flags;
		417	u8 rrtype;
		418	u8 def_ttl;
		419
		420	u16 client;
		421	u16 uid; // to make request unique
		422
		423	u16 max_size;
		424	u8 seq_cdc;
		425	u8 req_cdc;
		426
		427	u8 rep_cdc;
		428	u8 r2, r3, r4;
		429
		430	u8 r5, r6, r7, r8;
		431
		432	void reset (int clientid);
		433	bool valid ();
		434	};
		435
		436	int dns_cfg::next_uid;
		437
		438	void dns_cfg::reset (int clientid)
		439	{
		440	id1 = 'G';
		441	id2 = 'V';
		442	id3 = 'P';
		443	id4 = 'E';
		444
		445	version = 1;
		446
		447	rrtype = RR_TYPE_TXT;
		448	flags = 0;
		449	def_ttl = 0;
		450	seq_cdc = 26;
		451	req_cdc = 62;
		452	rep_cdc = 0;
		453	max_size = ntohs (MAX_PKT_SIZE);
		454	client = ntohs (clientid);
		455	uid = next_uid++;
		456
		457	r2 = r3 = r4 = 0;
		458	r4 = r5 = r6 = r7 = 0;
		459	}
		460
		461	bool dns_cfg::valid ()
		462	{
		463	return id1 == 'G'
		464	&& id2 == 'V'
		465	&& id3 == 'P'
		466	&& id4 == 'E'
		467	&& seq_cdc == 26
		468	&& req_cdc == 62
		469	&& rep_cdc == 0
		470	&& version == 1
		471	&& max_size == ntohs (MAX_PKT_SIZE);
		472	}
		473
384	struct dns_packet : net_packet	474	struct dns_packet : net_packet
385	{	475	{
386	u16 id;	476	u16 id;
387	u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4	477	u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4
388	u16 qdcount, ancount, nscount, arcount;	478	u16 qdcount, ancount, nscount, arcount;
389		479
390	u8 data[MAXSIZE - 6 * 2];	480	u8 data [MAXSIZE - 6 * 2];
391		481
392	int decode_label (char *data, int size, int &offs);	482	int decode_label (char *data, int size, int &offs);
393	};	483	};
394		484
395	int dns_packet::decode_label (char *data, int size, int &offs)	485	int dns_packet::decode_label (char *data, int size, int &offs)
…		…
426	return data - orig;	516	return data - orig;
427	}	517	}
428		518
429	/////////////////////////////////////////////////////////////////////////////	519	/////////////////////////////////////////////////////////////////////////////
430		520
431	struct dns_req
432	{
433	dns_packet *pkt;
434	tstamp next;
435	int retry;
436	connection *conn;
437	int seqno;
438
439	dns_req (connection *c);
440	void gen_stream_req (int seqno, byte_stream *stream);
441	};
442
443	static u16 dns_id = 12098; // TODO: should be per-vpn	521	static u16 dns_id = 0; // TODO: should be per-vpn
444		522
445	static u16 next_id ()	523	static u16 next_id ()
446	{	524	{
		525	if (!dns_id)
		526	dns_id = time (0);
		527
447	// the simplest lsfr with periodicity 65535 i could find	528	// the simplest lsfr with periodicity 65535 i could find
448	dns_id = (dns_id << 1)	529	dns_id = (dns_id << 1)
449	\| (((dns_id >> 1)	530	\| (((dns_id >> 1)
450	^ (dns_id >> 2)	531	^ (dns_id >> 2)
451	^ (dns_id >> 4)	532	^ (dns_id >> 4)
452	^ (dns_id >> 15)) & 1);	533	^ (dns_id >> 15)) & 1);
453		534
454	return dns_id;	535	return dns_id;
455	}	536	}
456		537
457	dns_req::dns_req (connection *c)	538	struct dns_rcv;
458	: conn (c)	539	struct dns_snd;
		540
		541	struct dns_connection
459	{	542	{
460	next = 0;	543	connection *c;
		544	struct vpn *vpn;
		545
		546	dns_cfg cfg;
		547
		548	bool established;
		549
		550	tstamp last_received;
		551	tstamp last_sent;
		552	double last_latency;
		553	double poll_interval, send_interval;
		554
		555	vector<dns_rcv *> rcvpq;
		556
		557	byte_stream rcvdq; int rcvseq;
		558	byte_stream snddq; int sndseq;
		559
		560	void time_cb (time_watcher &w); time_watcher tw;
		561	void receive_rep (dns_rcv *r);
		562
		563	dns_connection (connection *c);
		564	~dns_connection ();
		565	};
		566
		567	struct dns_snd
		568	{
		569	dns_packet *pkt;
		570	tstamp timeout, sent;
		571	int retry;
		572	struct dns_connection *dns;
		573	int seqno;
		574	bool stdhdr;
		575
		576	void gen_stream_req (int seqno, byte_stream &stream);
		577	void gen_syn_req ();
		578
		579	dns_snd (dns_connection *dns);
		580	~dns_snd ();
		581	};
		582
		583	dns_snd::dns_snd (dns_connection *dns)
		584	: dns (dns)
		585	{
		586	timeout = 0;
461	retry = 0;	587	retry = 0;
		588	seqno = 0;
		589	sent = NOW;
		590	stdhdr = false;
462		591
463	pkt = new dns_packet;	592	pkt = new dns_packet;
464		593
465	pkt->id = next_id ();	594	pkt->id = next_id ();
466	}	595	}
467		596
		597	dns_snd::~dns_snd ()
		598	{
		599	delete pkt;
		600	}
		601
		602	static void append_domain (dns_packet &pkt, int &offs, const char *domain)
		603	{
		604	// add tunnel domain
		605	for (;;)
		606	{
		607	const char *end = strchr (domain, '.');
		608
		609	if (!end)
		610	end = domain + strlen (domain);
		611
		612	int len = end - domain;
		613
		614	pkt [offs++] = len;
		615	memcpy (pkt.at (offs), domain, len);
		616	offs += len;
		617
		618	if (!*end)
		619	break;
		620
		621	domain = end + 1;
		622	}
		623	}
		624
468	void dns_req::gen_stream_req (int seqno, byte_stream *stream)	625	void dns_snd::gen_stream_req (int seqno, byte_stream &stream)
469	{	626	{
		627	stdhdr = true;
470	this->seqno = seqno;	628	this->seqno = seqno;
		629
		630	timeout = NOW + INITIAL_TIMEOUT;
471		631
472	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);	632	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
473	pkt->qdcount = htons (1);	633	pkt->qdcount = htons (1);
474		634
475	int offs = 6*2;	635	int offs = 6*2;
476	int dlen = MAX_DOMAIN_SIZE - (strlen (THISNODE->domain) + 2);	636	int dlen = MAX_DOMAIN_SIZE - (strlen (dns->c->conf->domain) + 2);
477	// MAX_DOMAIN_SIZE is technically 255, but bind doesn't compress responses well,	637	// MAX_DOMAIN_SIZE is technically 255, but bind doesn't compress responses well,
478	// so we need to have space for 2*MAX_DOMAIN_SIZE + header + extra	638	// so we need to have space for 2*MAX_DOMAIN_SIZE + header + extra
479		639
480	char enc[256], *encp = enc;	640	char enc[256], *encp = enc;
481	encode_header (enc, THISNODE->id, seqno);	641	encode_header (enc, THISNODE->id, seqno);
482		642
483	int datalen = cdc62.decode_len (dlen - (dlen + MAX_LBL_SIZE - 1) / MAX_LBL_SIZE - HDRSIZE);	643	int datalen = cdc62.decode_len (dlen - (dlen + MAX_LBL_SIZE - 1) / MAX_LBL_SIZE - HDRSIZE);
484		644
485	if (datalen > stream->size ())	645	if (datalen > stream.size ())
486	datalen = stream->size ();	646	datalen = stream.size ();
487		647
488	int enclen = cdc62.encode (enc + HDRSIZE, stream->begin (), datalen) + HDRSIZE;	648	int enclen = cdc62.encode (enc + HDRSIZE, stream.begin (), datalen) + HDRSIZE;
489
490	printf ("cdc62.encode %d->%d:%02x %02x %02x %02x\n", datalen, enclen,
491	stream->begin ()[0],
492	stream->begin ()[1],
493	stream->begin ()[2],
494	stream->begin ()[3]);
495
496	stream->remove (datalen);	649	stream.remove (datalen);
497		650
498	while (enclen)	651	while (enclen)
499	{	652	{
500	int lbllen = enclen < MAX_LBL_SIZE ? enclen : MAX_LBL_SIZE;	653	int lbllen = enclen < MAX_LBL_SIZE ? enclen : MAX_LBL_SIZE;
501		654
…		…
506	encp += lbllen;	659	encp += lbllen;
507		660
508	enclen -= lbllen;	661	enclen -= lbllen;
509	}	662	}
510		663
511	const char *suffix = THISNODE->domain;	664	append_domain (*pkt, offs, dns->c->conf->domain);
512
513	// add tunnel domain
514	for (;;)
515	{
516	const char *end = strchr (suffix, '.');
517
518	if (!end)
519	end = suffix + strlen (suffix);
520
521	int len = end - suffix;
522
523	(*pkt)[offs++] = len;
524	memcpy (&((*pkt)[offs]), suffix, len);
525	offs += len;
526
527	if (!*end)
528	break;
529
530	suffix = end + 1;
531	}
532		665
533	(*pkt)[offs++] = 0;	666	(*pkt)[offs++] = 0;
534	(pkt)[offs++] = RR_TYPE_ANY >> 8; (pkt)[offs++] = RR_TYPE_ANY;	667	(pkt)[offs++] = RR_TYPE_ANY >> 8; (pkt)[offs++] = RR_TYPE_ANY;
		668	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;
		669
		670	pkt->len = offs;
		671	}
		672
		673	void dns_snd::gen_syn_req ()
		674	{
		675	timeout = NOW + INITIAL_SYN_TIMEOUT;
		676
		677	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
		678	pkt->qdcount = htons (1);
		679
		680	int offs = 6 * 2;
		681
		682	int elen = cdc26.encode ((char )pkt->at (offs + 1), (u8 )&dns->cfg, sizeof (dns_cfg));
		683
		684	assert (elen <= MAX_LBL_SIZE);
		685
		686	(*pkt)[offs] = elen;
		687	offs += elen + 1;
		688	append_domain (*pkt, offs, dns->c->conf->domain);
		689
		690	(*pkt)[offs++] = 0;
		691	(pkt)[offs++] = RR_TYPE_A >> 8; (pkt)[offs++] = RR_TYPE_A;
535	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;	692	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;
536		693
537	pkt->len = offs;	694	pkt->len = offs;
538	}	695	}
539		696
…		…
558	{	715	{
559	delete pkt;	716	delete pkt;
560	}	717	}
561		718
562	/////////////////////////////////////////////////////////////////////////////	719	/////////////////////////////////////////////////////////////////////////////
563		720
564	struct dns_cfg	721	dns_connection::dns_connection (connection *c)
		722	: c (c)
		723	, rcvdq (MAX_BACKLOG * 2)
		724	, snddq (MAX_BACKLOG * 2)
		725	, tw (this, &dns_connection::time_cb)
565	{	726	{
566	u8 id1, id2, id3;	727	vpn = c->vpn;
567	u8 def_ttl;
568	u8 unused1;
569	u16 max_size;
570	u8 flags1, flags2;
571	};
572		728
		729	established = false;
		730
		731	rcvseq = sndseq = 0;
		732
		733	last_sent = last_received = 0;
		734	poll_interval = MIN_POLL_INTERVAL;
		735	send_interval = 0.5; // starting rate
		736	last_latency = INITIAL_TIMEOUT;
		737	}
		738
		739	dns_connection::~dns_connection ()
		740	{
		741	for (vector<dns_rcv *>::iterator i = rcvpq.begin ();
		742	i != rcvpq.end ();
		743	++i)
		744	delete *i;
		745	}
		746
573	void connection::dnsv4_receive_rep (struct dns_rcv *r)	747	void dns_connection::receive_rep (dns_rcv *r)
574	{	748	{
		749	if (r->datalen)
		750	{
		751	last_received = NOW;
		752	tw.trigger ();
		753
		754	poll_interval = send_interval;
		755	}
		756	else
		757	{
		758	poll_interval *= 1.5;
		759	if (poll_interval > MAX_POLL_INTERVAL)
		760	poll_interval = MAX_POLL_INTERVAL;
		761	}
		762
575	dns_rcvpq.push_back (r);	763	rcvpq.push_back (r);
576		764
577	printf ("%d got inketc %d (%02x %02x %02x %02x)\n", THISNODE->id, r->seqno
578	,r->data[0]
579	,r->data[1]
580	,r->data[2]
581	,r->data[3]
582	);
583	redo:	765	redo:
584		766
585	// find next packet	767	// find next packet
586	for (vector<dns_rcv *>::iterator i = dns_rcvpq.end (); i-- != dns_rcvpq.begin (); )	768	for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); )
587	if (SEQNO_EQ (dns_rcvseq, (*i)->seqno))	769	if (SEQNO_EQ (rcvseq, (*i)->seqno))
588	{	770	{
589	// enter the packet into our input stream	771	// enter the packet into our input stream
590	r = *i;	772	r = *i;
591		773
592	printf ("%d checking for older packet %d\n", THISNODE->id, dns_rcvseq);
593	// remove the oldest packet, look forward, as it's oldest first	774	// remove the oldest packet, look forward, as it's oldest first
594	for (vector<dns_rcv *>::iterator j = dns_rcvpq.begin (); j != dns_rcvpq.end (); ++j)	775	for (vector<dns_rcv *>::iterator j = rcvpq.begin (); j != rcvpq.end (); ++j)
595	if (SEQNO_EQ ((*j)->seqno, dns_rcvseq - MAX_WINDOW))	776	if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW))
596	{	777	{
597	printf ("%d removing %d\n", THISNODE->id, (*j)->seqno);
598	delete *j;	778	delete *j;
599	dns_rcvpq.erase (j);	779	rcvpq.erase (j);
600	break;	780	break;
601	}	781	}
602		782
603	dns_rcvseq = (dns_rcvseq + 1) & SEQNO_MASK;	783	rcvseq = (rcvseq + 1) & SEQNO_MASK;
604		784
605	if (!dns_snddq && !dns_rcvdq)	785	if (!rcvdq.put (r->data, r->datalen))
606	{	786	{
607	dns_rcvdq = new byte_stream (MAX_BACKLOG * 2);	787	slog (L_ERR, "DNS: !rcvdq.put (r->data, r->datalen)");
608	dns_snddq = new byte_stream (MAX_BACKLOG);	788	abort (); // MUST never overflow, can be caused by data corruption, TODO
609
610	dns_si.set (::conf.dns_forw_host, ::conf.dns_forw_port, PROT_DNSv4);
611	}	789	}
612		790
613	if (!dns_rcvdq->put (r->data, r->datalen))
614	abort (); // MUST never overflow, can be caused by data corruption, TODO
615
616	while (vpn_packet *pkt = dns_rcvdq->get ())	791	while (vpn_packet *pkt = rcvdq.get ())
617	{	792	{
618	sockinfo si;	793	sockinfo si;
619	si.host = 0; si.port = 0; si.prot = PROT_DNSv4;	794	si.host = 0x01010101; si.port = htons (c->conf->id); si.prot = PROT_DNSv4;
620		795
621	vpn->recv_vpn_packet (pkt, si);	796	vpn->recv_vpn_packet (pkt, si);
		797
		798	delete pkt;
622	}	799	}
623		800
624	// check for further packets	801	// check for further packets
625	goto redo;	802	goto redo;
626	}	803	}
627	}	804	}
628		805
629	dns_packet *	806	void
630	vpn::dnsv4_server (dns_packet *pkt)	807	vpn::dnsv4_server (dns_packet &pkt)
631	{	808	{
632	u16 flags = ntohs (pkt->flags);	809	u16 flags = ntohs (pkt.flags);
633		810
634	//memcpy (&((rep)[0]), &((pkt)[0]), pkt->len);
635	int offs = 6 * 2; // skip header	811	int offs = 6 * 2; // skip header
636		812
637	pkt->flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);	813	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);
638		814
639	if (!(flags & (FLAG_RESPONSE \| FLAG_OP_MASK \| FLAG_TC))	815	if (0 == (flags & (FLAG_RESPONSE \| FLAG_OP_MASK))
640	&& pkt->qdcount == htons (1))	816	&& pkt.qdcount == htons (1))
641	{	817	{
642	char qname[MAXSIZE];	818	char qname [MAXSIZE];
643	int qlen = pkt->decode_label ((char *)qname, MAXSIZE - offs, offs);	819	int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
644		820
645	u16 qtype = (pkt) [offs++] << 8; qtype \|= (pkt) [offs++];	821	u16 qtype = pkt [offs++] << 8; qtype \|= pkt [offs++];
646	u16 qclass = (pkt) [offs++] << 8; qclass \|= (pkt) [offs++];	822	u16 qclass = pkt [offs++] << 8; qclass \|= pkt [offs++];
647		823
648	pkt->qdcount = htons (1);	824	pkt.qdcount = htons (1);
649	pkt->ancount = 0;	825	pkt.ancount = 0;
650	pkt->nscount = 0; // should be self, as other nameservers reply like this	826	pkt.nscount = 0; // should be self, as other nameservers reply like this
651	pkt->arcount = 0; // a record for self, as other nameservers reply like this	827	pkt.arcount = 0; // a record for self, as other nameservers reply like this
652		828
653	pkt->flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_NXDOMAIN);	829	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_SERVFAIL);
654		830
655	int dlen = strlen (THISNODE->domain);	831	int dlen = strlen (THISNODE->domain);
656		832
657	if (qclass == RR_CLASS_IN	833	if (qclass == RR_CLASS_IN
658	&& (qtype == RR_TYPE_ANY \|\| qtype == RR_TYPE_TXT)
659	&& qlen > dlen + 1 + HDRSIZE	834	&& qlen > dlen + 1
660	&& !memcmp (qname + qlen - dlen - 1, THISNODE->domain, dlen))	835	&& !memcmp (qname + qlen - (dlen + 1), THISNODE->domain, dlen))
661	{	836	{
662	// correct class, domain: parse	837	// now generate reply
663	int client, seqno;	838	pkt.ancount = htons (1); // one answer RR
664	decode_header (qname, client, seqno);	839	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_OK);
665		840
666	u8 data[MAXSIZE];	841	if ((qtype == RR_TYPE_ANY
667	int datalen = cdc62.decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE));	842	\|\| qtype == RR_TYPE_TXT
668		843	\|\| qtype == RR_TYPE_NULL)
669	printf ("cdc62.decode %d(%d): %02x %02x %02x %02x\n",
670	qlen - (dlen + 1 + HDRSIZE), datalen	844	&& qlen > dlen + 1 + HDRSIZE)
671	,data[0]
672	,data[1]
673	,data[2]
674	,data[3]);
675
676	printf ("SRV got %d <%.*s>\n", seqno, qlen, qname + HDRSIZE);//D
677	printf ("SRV got %d <%.*s>\n", seqno, qlen - (dlen + 1 + HDRSIZE), qname + HDRSIZE);//D
678
679	if (0 < client && client <= conns.size ())
680	{	845	{
		846	// correct class, domain: parse
		847	int client, seqno;
		848	decode_header (qname, client, seqno);
		849
		850	u8 data[MAXSIZE];
		851	int datalen = cdc62.decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE));
		852
		853	if (0 < client && client <= conns.size ())
		854	{
681	connection *c = conns [client - 1];	855	connection *c = conns [client - 1];
		856	dns_connection *dns = c->dns;
		857	dns_rcv *rcv;
		858	bool in_seq;
682		859
		860	if (dns)
		861	{
683	for (vector<dns_rcv *>::iterator i = c->dns_rcvpq.end (); i-- != c->dns_rcvpq.begin (); )	862	for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); )
684	if (SEQNO_EQ ((*i)->seqno, seqno))	863	if (SEQNO_EQ ((*i)->seqno, seqno))
		864	{
		865	// already seen that request: simply reply with the cached reply
		866	dns_rcv r = i;
		867
		868	slog (L_DEBUG, "DNS: duplicate packet received ID %d, SEQ %d", htons (r->pkt->id), seqno);
		869
		870	// refresh header & id, as the retry count could have changed
		871	memcpy (r->pkt->at (6 * 2 + 1), pkt.at (6 * 2 + 1), HDRSIZE);
		872	r->pkt->id = pkt.id;
		873
		874	memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len);
		875
		876	goto duplicate_request;
		877	}
		878
		879	in_seq = dns->rcvseq == seqno;
		880
		881	// new packet, queue
		882	rcv = new dns_rcv (seqno, data, datalen);
		883	dns->receive_rep (rcv);
		884	}
		885
685	{	886	{
686	// already seen that request: simply reply with the cached reply	887	pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section
687	dns_rcv r = i;
688		888
689	printf ("DUPLICATE %d\n", htons (r->pkt->id));//D	889	int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A;
		890	pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type
		891	pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
		892	pkt [offs++] = 0; pkt [offs++] = 0;
		893	pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL
690		894
691	memcpy (pkt->at (0), r->pkt->at (0), offs = r->pkt->len);	895	int rdlen_offs = offs += 2;
692	pkt->id = r->pkt->id;	896
693	goto duplicate_request;	897	int dlen = (dns ? ntohs (dns->cfg.max_size) : MAX_PKT_SIZE) - offs;
		898	// bind doesn't compress well, so reduce further by one label length
		899	dlen -= qlen;
		900
		901	if (dns)
		902	{
		903	// only put data into in-order sequence packets, if
		904	// we receive out-of-order packets we generate empty
		905	// replies
		906	while (dlen > 1 && !dns->snddq.empty () && in_seq)
		907	{
		908	int txtlen = dlen <= 255 ? dlen - 1 : 255;
		909
		910	if (txtlen > dns->snddq.size ())
		911	txtlen = dns->snddq.size ();
		912
		913	pkt[offs++] = txtlen;
		914	memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
		915	offs += txtlen;
		916	dns->snddq.remove (txtlen);
		917
		918	dlen -= txtlen + 1;
		919	}
		920
		921	// avoid empty TXT rdata
		922	if (offs == rdlen_offs)
		923	pkt[offs++] = 0;
		924
		925	slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
		926	}
		927	else
		928	{
		929	// send RST
		930	pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
		931	pkt [offs++] = CMD_IP_RST;
		932	}
		933
		934	int rdlen = offs - rdlen_offs;
		935
		936	pkt [rdlen_offs - 2] = rdlen >> 8;
		937	pkt [rdlen_offs - 1] = rdlen;
		938
		939	if (dns)
		940	{
		941	// now update dns_rcv copy
		942	rcv->pkt->len = offs;
		943	memcpy (rcv->pkt->at (0), pkt.at (0), offs);
		944	}
694	}	945	}
695		946
696	// new packet, queue	947	duplicate_request: ;
697	dns_rcv *rcv = new dns_rcv (seqno, data, datalen);	948	}
698	c->dnsv4_receive_rep (rcv);	949	else
699
700	// now generate reply
701	pkt->ancount = htons (1); // one answer RR
702	pkt->flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_OK);	950	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);
		951	}
		952	else if (qtype == RR_TYPE_A
		953	&& qlen > dlen + 1 + cdc26.encode_len (sizeof (dns_cfg)))
		954	{
		955	dns_cfg cfg;
		956	cdc26.decode ((u8 *)&cfg, qname, cdc26.encode_len (sizeof (dns_cfg)));
		957	int client = ntohs (cfg.client);
703		958
704	(*pkt) [offs++] = 0xc0;
705	(pkt) [offs++] = 6 2; // same as in query section	959	pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section
706		960
707	(pkt) [offs++] = RR_TYPE_TXT >> 8; (pkt) [offs++] = RR_TYPE_TXT;	961	pkt [offs++] = RR_TYPE_A >> 8; pkt [offs++] = RR_TYPE_A; // type
708	(pkt) [offs++] = RR_CLASS_IN >> 8; (pkt) [offs++] = RR_CLASS_IN;	962	pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
709
710	(pkt) [offs++] = 0; (pkt) [offs++] = 0;	963	pkt [offs++] = 0; pkt [offs++] = 0;
711	(pkt) [offs++] = 0; (pkt) [offs++] = 0; // TTL	964	pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL
		965	pkt [offs++] = 0; pkt [offs++] = 4; // rdlength
712		966
713	int dlen = MAX_PKT_SIZE - offs - 2;	967	slog (L_INFO, _("DNS: client %d connects"), client);
714		968
715	// bind doesn't compress well, so reduce further by one label length	969	pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
716	dlen -= qlen;	970	pkt [offs++] = CMD_IP_REJ;
717		971
718	int rdlen_offs = offs += 2;	972	if (0 < client && client <= conns.size ())
719
720	while (c->dns_snddq
721	&& !c->dns_snddq->empty ()
722	&& dlen > 1)
723	{	973	{
724	int txtlen = dlen <= 255 ? dlen - 1 : 255;	974	connection *c = conns [client - 1];
725		975
726	if (txtlen > c->dns_snddq->size ())	976	if (cfg.valid ())
727	txtlen = c->dns_snddq->size ();	977	{
		978	pkt [offs - 1] = CMD_IP_SYN;
728		979
729	(*pkt)[offs++] = txtlen;	980	delete c->dns;
730	memcpy (pkt->at (offs), c->dns_snddq->begin (), txtlen);	981	c->dns = new dns_connection (c);
731	offs += txtlen;	982	c->dns->cfg = cfg;
732	c->dns_snddq->remove (txtlen);	983	}
733
734	dlen -= txtlen + 1;
735	}	984	}
736
737	// avoid empty TXT rdata
738	if (offs == rdlen_offs)
739	(*pkt)[offs++] = 0;
740
741	int rdlen = offs - rdlen_offs;
742
743	(*pkt) [rdlen_offs - 2] = rdlen >> 8;
744	(*pkt) [rdlen_offs - 1] = rdlen;
745
746	// now update dns_rcv copy
747	rcv->pkt->len = offs;
748	memcpy (rcv->pkt->at (0), pkt->at (0), offs);
749
750	duplicate_request: ;
751	}	985	}
752	else
753	pkt->flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);
754	}	986	}
755		987
756	pkt->len = offs;	988	pkt.len = offs;
757	}	989	}
758
759	return pkt;
760	}	990	}
761		991
762	void	992	void
763	vpn::dnsv4_client (dns_packet *pkt)	993	vpn::dnsv4_client (dns_packet &pkt)
764	{	994	{
765	u16 flags = ntohs (pkt->flags);	995	u16 flags = ntohs (pkt.flags);
766	int offs = 6 * 2; // skip header	996	int offs = 6 * 2; // skip header
767		997
768	pkt->qdcount = ntohs (pkt->qdcount);	998	pkt.qdcount = ntohs (pkt.qdcount);
769	pkt->ancount = ntohs (pkt->ancount);	999	pkt.ancount = ntohs (pkt.ancount);
770		1000
771	// go through our request list and find the corresponding request	1001	// go through our request list and find the corresponding request
772	for (vector<dns_req *>::iterator i = dns_sndpq.begin ();	1002	for (vector<dns_snd *>::iterator i = dns_sndpq.begin ();
773	i != dns_sndpq.end ();	1003	i != dns_sndpq.end ();
774	++i)	1004	++i)
775	if ((*i)->pkt->id == pkt->id)	1005	if ((*i)->pkt->id == pkt.id)
776	{	1006	{
		1007	dns_connection dns = (i)->dns;
777	connection c = (i)->conn;	1008	connection *c = dns->c;
778	int seqno = (*i)->seqno;	1009	int seqno = (*i)->seqno;
779	u8 data[MAXSIZE], *datap = data;	1010	u8 data[MAXSIZE], *datap = data;
780		1011
		1012	if ((*i)->retry)
		1013	{
		1014	dns->send_interval *= 1.01;
		1015	if (dns->send_interval > MAX_SEND_INTERVAL)
		1016	dns->send_interval = MAX_SEND_INTERVAL;
		1017	}
		1018	else
		1019	{
		1020	#if 1
		1021	dns->send_interval *= 0.999;
		1022	#endif
		1023	if (dns->send_interval < MIN_SEND_INTERVAL)
		1024	dns->send_interval = MIN_SEND_INTERVAL;
		1025
		1026	// the latency surely puts an upper bound on
		1027	// the minimum send interval
		1028	double latency = NOW - (*i)->sent;
		1029	dns->last_latency = latency;
		1030
		1031	if (dns->send_interval > latency)
		1032	dns->send_interval = latency;
		1033	}
		1034
781	delete *i;	1035	delete *i;
782	dns_sndpq.erase (i);	1036	dns_sndpq.erase (i);
783		1037
784	if (flags & (FLAG_RESPONSE \| FLAG_OP_MASK \| FLAG_TC))	1038	if (flags & FLAG_RESPONSE && !(flags & FLAG_OP_MASK))
785	{	1039	{
786	char qname[MAXSIZE];	1040	char qname[MAXSIZE];
787		1041
788	while (pkt->qdcount-- && offs < MAXSIZE - 4)	1042	while (pkt.qdcount-- && offs < MAXSIZE - 4)
789	{	1043	{
790	int qlen = pkt->decode_label ((char *)qname, MAXSIZE - offs, offs);	1044	int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
791	offs += 4; // skip qtype, qclass	1045	offs += 4; // skip qtype, qclass
792	}	1046	}
793		1047
794	while (pkt->ancount-- && offs < MAXSIZE - 10)	1048	while (pkt.ancount-- && offs < MAXSIZE - 10 && datap)
795	{	1049	{
796	int qlen = //D
797	pkt->decode_label ((char *)qname, MAXSIZE - offs, offs);	1050	int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
798		1051
799	printf ("got reply to <%.*s>\n", qlen, qname);//D
800
801	u16 qtype = (pkt) [offs++] << 8; qtype \|= (pkt) [offs++];	1052	u16 qtype = pkt [offs++] << 8; qtype \|= pkt [offs++];
802	u16 qclass = (pkt) [offs++] << 8; qclass \|= (pkt) [offs++];	1053	u16 qclass = pkt [offs++] << 8; qclass \|= pkt [offs++];
803	u32 ttl = (*pkt) [offs++] << 24;	1054	u32 ttl = pkt [offs++] << 24;
804	ttl \|= (*pkt) [offs++] << 16;	1055	ttl \|= pkt [offs++] << 16;
805	ttl \|= (*pkt) [offs++] << 8;	1056	ttl \|= pkt [offs++] << 8;
806	ttl \|= (*pkt) [offs++];	1057	ttl \|= pkt [offs++];
807
808	u16 rdlen = (pkt) [offs++] << 8; rdlen \|= (pkt) [offs++];	1058	u16 rdlen = pkt [offs++] << 8; rdlen \|= pkt [offs++];
809		1059
810	if (rdlen <= MAXSIZE - offs)	1060	if (qtype == RR_TYPE_NULL \|\| qtype == RR_TYPE_TXT)
811	{	1061	{
812	// decode bytes, finally	1062	if (rdlen <= MAXSIZE - offs)
813
814	while (rdlen)
815	{	1063	{
		1064	// decode bytes, finally
		1065
		1066	while (rdlen)
		1067	{
816	int txtlen = (*pkt) [offs++];	1068	int txtlen = pkt [offs++];
817		1069
818	assert (txtlen + offs < MAXSIZE - 1);	1070	assert (txtlen + offs < MAXSIZE - 1);
819		1071
820	memcpy (datap, pkt->at (offs), txtlen);	1072	memcpy (datap, pkt.at (offs), txtlen);
821	datap += txtlen; offs += txtlen;	1073	datap += txtlen; offs += txtlen;
822		1074
823	rdlen -= txtlen + 1;	1075	rdlen -= txtlen + 1;
		1076	}
824	}	1077	}
825
826	}	1078	}
		1079	else if (qtype == RR_TYPE_A)
		1080	{
		1081	u8 ip [4];
827		1082
		1083	ip [0] = pkt [offs++];
		1084	ip [1] = pkt [offs++];
		1085	ip [2] = pkt [offs++];
		1086	ip [3] = pkt [offs++];
		1087
		1088	if (ip [0] == CMD_IP_1
		1089	&& ip [1] == CMD_IP_2
		1090	&& ip [2] == CMD_IP_3)
		1091	{
		1092	slog (L_TRACE, _("DNS: got tunnel meta command %02x"), ip [3]);
		1093
		1094	if (ip [3] == CMD_IP_RST)
		1095	{
		1096	slog (L_DEBUG, _("DNS: got tunnel RST request"));
		1097
		1098	delete dns; c->dns = 0;
		1099
		1100	return;
		1101	}
		1102	else if (ip [3] == CMD_IP_SYN)
		1103	{
		1104	slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us."));
		1105	dns->established = true;
		1106	}
		1107	else if (ip [3] == CMD_IP_REJ)
		1108	{
		1109	slog (L_DEBUG, _("DNS: got tunnel REJ reply, server does not like us, aborting."));
		1110	abort ();
		1111	}
		1112	else
		1113	slog (L_INFO, _("DNS: got unknown meta command %02x"), ip [3]);
		1114	}
		1115	else
		1116	slog (L_INFO, _("DNS: got spurious a record %d.%d.%d.%d"),
		1117	ip [0], ip [1], ip [2], ip [3]);
		1118
		1119	return;
		1120	}
		1121
		1122	int client, rseqno;
		1123	decode_header (qname, client, rseqno);
		1124
		1125	if (client != THISNODE->id)
		1126	{
		1127	slog (L_INFO, _("DNS: got dns tunnel response with wrong clientid, ignoring"));
		1128	datap = 0;
		1129	}
		1130	else if (rseqno != seqno)
		1131	{
		1132	slog (L_DEBUG, _("DNS: got dns tunnel response with wrong seqno, badly caching nameserver?"));
		1133	datap = 0;
		1134	}
828	}	1135	}
829	}	1136	}
830		1137
831	// todo: pkt now used	1138	// todo: pkt now used
		1139	if (datap)
832	c->dnsv4_receive_rep (new dns_rcv (seqno, data, datap - data));	1140	dns->receive_rep (new dns_rcv (seqno, data, datap - data));
833		1141
834	break;	1142	break;
835	}	1143	}
836
837	delete pkt;
838	}	1144	}
839		1145
840	void	1146	void
841	vpn::dnsv4_ev (io_watcher &w, short revents)	1147	vpn::dnsv4_ev (io_watcher &w, short revents)
842	{	1148	{
…		…
844	{	1150	{
845	dns_packet *pkt = new dns_packet;	1151	dns_packet *pkt = new dns_packet;
846	struct sockaddr_in sa;	1152	struct sockaddr_in sa;
847	socklen_t sa_len = sizeof (sa);	1153	socklen_t sa_len = sizeof (sa);
848		1154
849	pkt->len = recvfrom (w.fd, &((pkt)[0]), MAXSIZE, 0, (sockaddr )&sa, &sa_len);	1155	pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len);
850		1156
851	if (pkt->len > 0)	1157	if (pkt->len > 0)
852	{	1158	{
853	if (pkt->flags & htons (FLAG_TC))	1159	if (ntohs (pkt->flags) & FLAG_RESPONSE)
		1160	dnsv4_client (*pkt);
		1161	else
854	{	1162	{
855	slog (L_WARN, _("DNS request/response truncated, check protocol settings."));	1163	dnsv4_server (*pkt);
856	//TODO connection reset	1164	sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len);
857	}	1165	}
858		1166
859	if (THISNODE->dns_port)	1167	delete pkt;
860	{
861	pkt = dnsv4_server (pkt);
862	sendto (w.fd, &((pkt)[0]), pkt->len, 0, (sockaddr )&sa, sa_len);
863	}
864	else
865	dnsv4_client (pkt);
866	}	1168	}
867	}	1169	}
868	}	1170	}
869		1171
870	bool	1172	bool
871	connection::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)	1173	vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
872	{	1174	{
873	// never initialized	1175	int client = ntohs (si.port);
874	if (!dns_snddq && !dns_rcvdq)
875	{
876	dns_rcvdq = new byte_stream (MAX_BACKLOG * 2);
877	dns_snddq = new byte_stream (MAX_BACKLOG);
878		1176
879	//dns_rcvseq = dns_sndseq = 0;	1177	assert (0 < client && client <= conns.size ());
880		1178
881	dns_si.set (::conf.dns_forw_host, ::conf.dns_forw_port, PROT_DNSv4);	1179	connection *c = conns [client - 1];
882	}	1180
		1181	if (!c->dns)
		1182	c->dns = new dns_connection (c);
883		1183
884	if (!dns_snddq->put (pkt))	1184	if (!c->dns->snddq.put (pkt))
885	return false;	1185	return false;
886		1186
887	// start timer if neccessary	1187	c->dns->tw.trigger ();
888	if (!THISNODE->dns_port && !dnsv4_tw.active)
889	dnsv4_cb (dnsv4_tw);
890		1188
891	return true;	1189	return true;
892	}	1190	}
893		1191
894	void	1192	void
		1193	connection::dnsv4_reset_connection ()
		1194	{
		1195	//delete dns; dns = 0; //TODO
		1196	}
		1197
		1198	#define NEXT(w) do { if (next > (w)) next = w; } while (0)
		1199
		1200	void
895	connection::dnsv4_cb (time_watcher &w)	1201	dns_connection::time_cb (time_watcher &w)
896	{	1202	{
		1203	// servers have to be polled
		1204	if (THISNODE->dns_port)
		1205	return;
		1206
897	// check for timeouts and (re)transmit	1207	// check for timeouts and (re)transmit
898	tstamp next = NOW + 60;	1208	tstamp next = NOW + poll_interval;
899	dns_req *send = 0;	1209	dns_snd *send = 0;
900		1210
901	for (vector<dns_req *>::iterator i = vpn->dns_sndpq.begin ();	1211	for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin ();
902	i != vpn->dns_sndpq.end ();	1212	i != vpn->dns_sndpq.end ();
903	++i)	1213	++i)
904	{	1214	{
905	dns_req r = i;	1215	dns_snd r = i;
906		1216
907	if (r->next <= NOW)	1217	if (r->timeout <= NOW)
908	{	1218	{
909	if (!send)	1219	if (!send)
910	{	1220	{
911	send = r;	1221	send = r;
912		1222
913	if (r->retry)//D
914	printf ("req %d:%d, retry %d\n", r->seqno, r->pkt->id, r->retry);
915	r->retry++;	1223	r->retry++;
916	r->next = NOW + r->retry;	1224	r->timeout = NOW + (r->retry * last_latency * 8.);
		1225
		1226	// the following code changes the query section a bit, forcing
		1227	// the forwarder to generate a new request
		1228	if (r->stdhdr)
		1229	{
		1230	//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);
		1231	//encode_header ((char )r->pkt->at (6 2 + 1), THISNODE->id, r->seqno, r->retry);
		1232	}
917	}	1233	}
918	}	1234	}
		1235	else
		1236	NEXT (r->timeout);
		1237	}
919		1238
920	if (r->next < next)	1239	if (last_sent + send_interval <= NOW)
921	next = r->next;
922	}	1240	{
923
924	if (!send	1241	if (!send)
		1242	{
		1243	// generate a new packet, if wise
		1244
		1245	if (!established)
		1246	{
		1247	if (vpn->dns_sndpq.empty ())
		1248	{
		1249	send = new dns_snd (this);
		1250
		1251	cfg.reset (THISNODE->id);
		1252	send->gen_syn_req ();
		1253	}
		1254	}
925	&& vpn->dns_sndpq.size () < MAX_OUTSTANDING)	1255	else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING
926	{	1256	&& !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
		1257	{
		1258	//printf ("sending data request etc.\n"); //D
		1259	if (!snddq.empty ())
		1260	{
		1261	poll_interval = send_interval;
		1262	NEXT (NOW + send_interval);
		1263	}
		1264
927	send = new dns_req (this);	1265	send = new dns_snd (this);
928	send->gen_stream_req (dns_sndseq, dns_snddq);	1266	send->gen_stream_req (sndseq, snddq);
		1267	send->timeout = NOW + last_latency * 8.;
		1268
		1269	sndseq = (sndseq + 1) & SEQNO_MASK;
		1270	}
		1271
		1272	if (send)
929	vpn->dns_sndpq.push_back (send);	1273	vpn->dns_sndpq.push_back (send);
		1274	}
930		1275
931	dns_sndseq = (dns_sndseq + 1) & SEQNO_MASK;
932	}
933
934	tstamp min_next = NOW + (1. / (tstamp)MAX_RATE);
935
936	if (send)	1276	if (send)
		1277	{
		1278	last_sent = NOW;
		1279	sendto (vpn->dnsv4_fd,
		1280	send->pkt->at (0), send->pkt->len, 0,
		1281	vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
		1282	}
937	{	1283	}
938	dns_packet *pkt = send->pkt;	1284	else
		1285	NEXT (last_sent + send_interval);
939		1286
940	next = min_next;	1287	slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d)",
		1288	poll_interval, send_interval, next - NOW,
		1289	vpn->dns_sndpq.size (), snddq.size ());
941		1290
942	sendto (vpn->dnsv4_fd, &((*pkt)[0]), pkt->len, 0, dns_si.sav4 (), dns_si.salenv4 ());	1291	// TODO: no idea when this happens, but when next < NOW, we have a problem
943	}	1292	if (next < NOW + 0.0001)
944	else if (next < min_next)	1293	next = NOW + 0.1;
945	next = min_next;
946		1294
947	w.start (next);	1295	w.start (next);
948	}	1296	}
949		1297
950	#endif	1298	#endif

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Comparing gvpe/src/vpn_dns.C (file contents): Revision 1.8 by pcg, Fri Mar 4 03:43:09 2005 UTC vs. Revision 1.24 by pcg, Mon Mar 7 01:31:26 2005 UTC

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Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.8 by pcg, Fri Mar 4 03:43:09 2005 UTC vs.
Revision 1.24 by pcg, Mon Mar 7 01:31:26 2005 UTC