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

Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.9 by pcg, Fri Mar 4 04:52:38 2005 UTC vs.
Revision 1.29 by pcg, Sun Mar 13 12:40:20 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 6.	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 2. // optimistic?
		58
		59	#define LATENCY_FACTOR 0.5 // RTT * LATENCY_FACTOR == sending rate
51	#define MAX_OUTSTANDING 400 // max. outstanding requests	60	#define MAX_OUTSTANDING 100 // max. outstanding requests
52	#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING	61	#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog
53	#define MAX_RATE 100 // requests/s
54	#define MAX_BACKLOG (10*1024) // size of protocol backlog, must be > MAXSIZE	62	#define MAX_BACKLOG (100*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE
55		63
56	#define MAX_DOMAIN_SIZE 220 // 255 is legal limit, but bind doesn't compress well	64	#define MAX_DOMAIN_SIZE 240 // 255 is legal limit, but bind doesn't compress well
57	// 240 leaves about 4 bytes of server reply data	65	// 240 leaves about 4 bytes of server reply data
58	// every two request byte sless give room for one reply byte	66	// every two request bytes less give room for one reply byte
59		67
60	#define SEQNO_MASK 0xffff	68	#define SEQNO_MASK 0x3fff
61	#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )	69	#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )
62		70
63	#define MAX_LBL_SIZE 63	71	#define MAX_LBL_SIZE 63
64	#define MAX_PKT_SIZE 512	72	#define MAX_PKT_SIZE 512
65		73
		74	#define RR_TYPE_A 1
		75	#define RR_TYPE_NULL 10
66	#define RR_TYPE_TXT 16	76	#define RR_TYPE_TXT 16
67	#define RR_TYPE_ANY 255	77	#define RR_TYPE_ANY 255
		78
68	#define RR_CLASS_IN 1	79	#define RR_CLASS_IN 1
		80
		81	#define CMD_IP_1 207
		82	#define CMD_IP_2 46
		83	#define CMD_IP_3 236
		84	#define CMD_IP_RST 29
		85	#define CMD_IP_SYN 113
		86	#define CMD_IP_REJ 32
69		87
70	// works for cmaps up to 255 (not 256!)	88	// works for cmaps up to 255 (not 256!)
71	struct charmap	89	struct charmap
72	{	90	{
73	enum { INVALID = (u8)255 };	91	enum { INVALID = (u8)255 };
…		…
153	return dec_len [len];	171	return dec_len [len];
154	}	172	}
155		173
156	unsigned int basecoder::encode (char dst, u8 src, unsigned int len)	174	unsigned int basecoder::encode (char dst, u8 src, unsigned int len)
157	{	175	{
158	if (!len)	176	if (!len \|\| len > MAX_DEC_LEN)
159	return 0;	177	return 0;
160		178
161	int elen = encode_len (len);	179	int elen = encode_len (len);
162		180
163	mp_limb_t m [MAX_LIMBS];	181	mp_limb_t m [MAX_LIMBS];
…		…
182	return elen;	200	return elen;
183	}	201	}
184		202
185	unsigned int basecoder::decode (u8 dst, char src, unsigned int len)	203	unsigned int basecoder::decode (u8 dst, char src, unsigned int len)
186	{	204	{
187	if (!len)	205	if (!len \|\| len > MAX_ENC_LEN)
188	return 0;	206	return 0;
189		207
190	u8 src_ [MAX_ENC_LEN];	208	u8 src_ [MAX_ENC_LEN];
191	unsigned int elen = 0;	209	unsigned int elen = 0;
192		210
…		…
239	}	257	}
240	abort ();	258	abort ();
241	}	259	}
242	#endif	260	#endif
243		261
244	// the following sequence has been crafted to	262	//static basecoder cdc64 ("_dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI-");
245	// a) look somewhat random
246	// b) the even (and odd) indices never share the same character as upper/lowercase
247	// the "_" is not valid but widely accepted (all octets should be supported, but let's be conservative)
248	// the other sequences are obviously derived
249	//static basecoder cdc63 ("_dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI");	263	//static basecoder cdc63 ("_dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI");
250	static basecoder cdc62 ("dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI");	264	static basecoder cdc62 ("dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI");
251	//static basecoder cdc36 ("dphzr06qmjkb34tsvl81xaef92wgyo57ucni"); // unused as of yet	265	//static basecoder cdc36 ("dphzr06qmjkb34tsvl81xaef92wgyo57ucni"); // unused as of yet
252	static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO");	266	static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO");
253		267
254	/////////////////////////////////////////////////////////////////////////////	268	/////////////////////////////////////////////////////////////////////////////
255		269
256	#define HDRSIZE 6	270	#define HDRSIZE 6
257		271
258	inline void encode_header (char *data, int clientid, int seqno)	272	inline void encode_header (char *data, int clientid, int seqno, int retry = 0)
259	{	273	{
260	u8 hdr[3] = { clientid, seqno >> 8, seqno };	274	seqno &= SEQNO_MASK;
		275
		276	u8 hdr[3] = {
		277	clientid,
		278	(seqno >> 8) \| (retry << 6),
		279	seqno,
		280	};
261		281
262	assert (clientid < 256);	282	assert (clientid < 256);
263		283
264	cdc26.encode (data, hdr, 3);	284	cdc26.encode (data, hdr, 3);
265	}	285	}
…		…
269	u8 hdr[3];	289	u8 hdr[3];
270		290
271	cdc26.decode (hdr, data, HDRSIZE);	291	cdc26.decode (hdr, data, HDRSIZE);
272		292
273	clientid = hdr[0];	293	clientid = hdr[0];
274	seqno = (hdr[1] << 8) \| hdr[2];	294	seqno = ((hdr[1] << 8) \| hdr[2]) & SEQNO_MASK;
275	}	295	}
276		296
277	/////////////////////////////////////////////////////////////////////////////	297	/////////////////////////////////////////////////////////////////////////////
278		298
279	struct byte_stream	299	struct byte_stream
…		…
308	}	328	}
309		329
310	void byte_stream::remove (int count)	330	void byte_stream::remove (int count)
311	{	331	{
312	if (count > fill)	332	if (count > fill)
313	abort ();	333	assert (count <= fill);
314		334
315	memmove (data, data + count, fill -= count);	335	memmove (data, data + count, fill -= count);
316	}	336	}
317		337
318	bool byte_stream::put (u8 *data, unsigned int datalen)	338	bool byte_stream::put (u8 *data, unsigned int datalen)
…		…
331	return false;	351	return false;
332		352
333	data [fill++] = pkt->len >> 8;	353	data [fill++] = pkt->len >> 8;
334	data [fill++] = pkt->len;	354	data [fill++] = pkt->len;
335		355
336	memcpy (data + fill, &((*pkt)[0]), pkt->len); fill += pkt->len;	356	memcpy (data + fill, pkt->at (0), pkt->len); fill += pkt->len;
337		357
338	return true;	358	return true;
339	}	359	}
340		360
341	vpn_packet *byte_stream::get ()	361	vpn_packet *byte_stream::get ()
342	{	362	{
		363	unsigned int len;
		364
		365	for (;;)
		366	{
343	int len = (data [0] << 8) \| data [1];	367	len = (data [0] << 8) \| data [1];
344		368
345	if (len > MAXSIZE && fill >= 2)	369	if (len <= MAXSIZE \|\| fill < 2)
346	abort (); // TODO handle this gracefully, connection reset	370	break;
347		371
		372	// TODO: handle this better than skipping, e.g. by reset
		373	slog (L_DEBUG, _("DNS: corrupted packet stream skipping a byte..."));
		374	remove (1);
		375	}
		376
348	if (fill < len + 2)	377	if (fill < len + 2)
349	return 0;	378	return 0;
350		379
351	vpn_packet *pkt = new vpn_packet;	380	vpn_packet *pkt = new vpn_packet;
352		381
353	pkt->len = len;	382	pkt->len = len;
354	memcpy (&((*pkt)[0]), data + 2, len);	383	memcpy (pkt->at (0), data + 2, len);
355	remove (len + 2);	384	remove (len + 2);
356		385
357	return pkt;	386	return pkt;
358	}	387	}
359		388
…		…
376	#define FLAG_RCODE_REFUSED ( 5 << 0)	405	#define FLAG_RCODE_REFUSED ( 5 << 0)
377		406
378	#define DEFAULT_CLIENT_FLAGS (FLAG_QUERY \| FLAG_OP_QUERY \| FLAG_RD)	407	#define DEFAULT_CLIENT_FLAGS (FLAG_QUERY \| FLAG_OP_QUERY \| FLAG_RD)
379	#define DEFAULT_SERVER_FLAGS (FLAG_RESPONSE \| FLAG_OP_QUERY \| FLAG_AA \| FLAG_RD \| FLAG_RA)	408	#define DEFAULT_SERVER_FLAGS (FLAG_RESPONSE \| FLAG_OP_QUERY \| FLAG_AA \| FLAG_RD \| FLAG_RA)
380		409
		410	struct dns_cfg
		411	{
		412	static int next_uid;
		413
		414	u8 id1, id2, id3, id4;
		415
		416	u8 version;
		417	u8 flags;
		418	u8 rrtype;
		419	u8 def_ttl;
		420
		421	u16 client;
		422	u16 uid; // to make request unique
		423
		424	u16 max_size;
		425	u8 seq_cdc;
		426	u8 req_cdc;
		427
		428	u8 rep_cdc;
		429	u8 r2, r3, r4;
		430
		431	u8 r5, r6, r7, r8;
		432
		433	void reset (int clientid);
		434	bool valid ();
		435	};
		436
		437	int dns_cfg::next_uid;
		438
		439	void dns_cfg::reset (int clientid)
		440	{
		441	id1 = 'G';
		442	id2 = 'V';
		443	id3 = 'P';
		444	id4 = 'E';
		445
		446	version = 1;
		447
		448	rrtype = RR_TYPE_TXT;
		449	flags = 0;
		450	def_ttl = 0;
		451	seq_cdc = 26;
		452	req_cdc = 62;
		453	rep_cdc = 0;
		454	max_size = htons (MAX_PKT_SIZE);
		455	client = htons (clientid);
		456	uid = next_uid++;
		457
		458	r2 = r3 = r4 = 0;
		459	r4 = r5 = r6 = r7 = 0;
		460	}
		461
		462	bool dns_cfg::valid ()
		463	{
		464	return id1 == 'G'
		465	&& id2 == 'V'
		466	&& id3 == 'P'
		467	&& id4 == 'E'
		468	&& seq_cdc == 26
		469	&& req_cdc == 62
		470	&& rep_cdc == 0
		471	&& version == 1;
		472	}
		473
381	struct dns_packet : net_packet	474	struct dns_packet : net_packet
382	{	475	{
383	u16 id;	476	u16 id;
384	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
385	u16 qdcount, ancount, nscount, arcount;	478	u16 qdcount, ancount, nscount, arcount;
386		479
387	u8 data[MAXSIZE - 6 * 2];	480	u8 data [MAXSIZE - 6 * 2];
388		481
389	int decode_label (char *data, int size, int &offs);	482	int decode_label (char *data, int size, int &offs);
390	};	483	};
391		484
392	int dns_packet::decode_label (char *data, int size, int &offs)	485	int dns_packet::decode_label (char *data, int size, int &offs)
…		…
423	return data - orig;	516	return data - orig;
424	}	517	}
425		518
426	/////////////////////////////////////////////////////////////////////////////	519	/////////////////////////////////////////////////////////////////////////////
427		520
428	struct dns_req
429	{
430	dns_packet *pkt;
431	tstamp next;
432	int retry;
433	struct dns_connection *dns;
434	int seqno;
435
436	dns_req (dns_connection *dns);
437	void gen_stream_req (int seqno, byte_stream &stream);
438	};
439
440	static u16 dns_id = 12098; // TODO: should be per-vpn	521	static u16 dns_id = 0; // TODO: should be per-vpn
441		522
442	static u16 next_id ()	523	static u16 next_id ()
443	{	524	{
		525	if (!dns_id)
		526	dns_id = time (0);
		527
444	// the simplest lsfr with periodicity 65535 i could find	528	// the simplest lsfr with periodicity 65535 i could find
445	dns_id = (dns_id << 1)	529	dns_id = (dns_id << 1)
446	\| (((dns_id >> 1)	530	\| (((dns_id >> 1)
447	^ (dns_id >> 2)	531	^ (dns_id >> 2)
448	^ (dns_id >> 4)	532	^ (dns_id >> 4)
449	^ (dns_id >> 15)) & 1);	533	^ (dns_id >> 15)) & 1);
450		534
451	return dns_id;	535	return dns_id;
452	}	536	}
453		537
		538	struct dns_rcv;
		539	struct dns_snd;
		540
		541	struct dns_connection
		542	{
		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 min_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
454	dns_req::dns_req (dns_connection *dns)	583	dns_snd::dns_snd (dns_connection *dns)
455	: dns (dns)	584	: dns (dns)
456	{	585	{
457	next = 0;	586	timeout = 0;
458	retry = 0;	587	retry = 0;
		588	seqno = 0;
		589	sent = NOW;
		590	stdhdr = false;
459		591
460	pkt = new dns_packet;	592	pkt = new dns_packet;
461		593
462	pkt->id = next_id ();	594	pkt->id = next_id ();
463	}	595	}
464		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
465	void dns_req::gen_stream_req (int seqno, byte_stream &stream)	625	void dns_snd::gen_stream_req (int seqno, byte_stream &stream)
466	{	626	{
		627	stdhdr = true;
467	this->seqno = seqno;	628	this->seqno = seqno;
		629
		630	timeout = NOW + INITIAL_TIMEOUT;
468		631
469	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);	632	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
470	pkt->qdcount = htons (1);	633	pkt->qdcount = htons (1);
471		634
472	int offs = 6*2;	635	int offs = 6*2;
473	int dlen = MAX_DOMAIN_SIZE - (strlen (THISNODE->domain) + 2);	636	int dlen = MAX_DOMAIN_SIZE - (strlen (dns->c->conf->domain) + 2);
474	// 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,
475	// 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
476		639
477	char enc[256], *encp = enc;	640	char enc[256], *encp = enc;
478	encode_header (enc, THISNODE->id, seqno);	641	encode_header (enc, THISNODE->id, seqno);
…		…
496	encp += lbllen;	659	encp += lbllen;
497		660
498	enclen -= lbllen;	661	enclen -= lbllen;
499	}	662	}
500		663
501	const char *suffix = THISNODE->domain;	664	append_domain (*pkt, offs, dns->c->conf->domain);
502
503	// add tunnel domain
504	for (;;)
505	{
506	const char *end = strchr (suffix, '.');
507
508	if (!end)
509	end = suffix + strlen (suffix);
510
511	int len = end - suffix;
512
513	(*pkt)[offs++] = len;
514	memcpy (&((*pkt)[offs]), suffix, len);
515	offs += len;
516
517	if (!*end)
518	break;
519
520	suffix = end + 1;
521	}
522		665
523	(*pkt)[offs++] = 0;	666	(*pkt)[offs++] = 0;
524	(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;
525	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;	692	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;
526		693
527	pkt->len = offs;	694	pkt->len = offs;
528	}	695	}
529		696
…		…
549	delete pkt;	716	delete pkt;
550	}	717	}
551		718
552	/////////////////////////////////////////////////////////////////////////////	719	/////////////////////////////////////////////////////////////////////////////
553		720
554	struct dns_connection
555	{
556	connection *c;
557	struct vpn *vpn;
558
559	vector<dns_rcv *> rcvpq;
560
561	int rcvseq;
562	int sndseq;
563
564	byte_stream rcvdq;
565	byte_stream snddq;
566
567	void time_cb (time_watcher &w); time_watcher tw;
568	void receive_rep (dns_rcv *r);
569
570	dns_connection (connection *c);
571	~dns_connection ();
572	};
573
574	dns_connection::dns_connection (connection *c)	721	dns_connection::dns_connection (connection *c)
575	: c (c)	722	: c (c)
576	, rcvdq (MAX_BACKLOG * 2)	723	, rcvdq (MAX_BACKLOG * 2)
577	, snddq (MAX_BACKLOG * 2)	724	, snddq (MAX_BACKLOG * 2)
578	, tw (this, &dns_connection::time_cb)	725	, tw (this, &dns_connection::time_cb)
579	{	726	{
580	vpn = c->vpn;	727	vpn = c->vpn;
581		728
		729	established = false;
		730
582	rcvseq = sndseq = 0;	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	min_latency = INITIAL_TIMEOUT;
583	}	737	}
584		738
585	dns_connection::~dns_connection ()	739	dns_connection::~dns_connection ()
586	{	740	{
587	for (vector<dns_rcv *>::iterator i = rcvpq.begin ();	741	for (vector<dns_rcv *>::iterator i = rcvpq.begin ();
588	i != rcvpq.end ();	742	i != rcvpq.end ();
589	++i)	743	++i)
590	delete *i;	744	delete *i;
591	}	745	}
592		746
593	struct dns_cfg
594	{
595	u8 id1, id2, id3;
596	u8 def_ttl;
597	u8 unused1;
598	u16 max_size;
599	u8 flags1, flags2;
600	};
601
602	void dns_connection::receive_rep (dns_rcv *r)	747	void dns_connection::receive_rep (dns_rcv *r)
603	{	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
		760	if (poll_interval > MAX_POLL_INTERVAL)
		761	poll_interval = MAX_POLL_INTERVAL;
		762	}
		763
604	rcvpq.push_back (r);	764	rcvpq.push_back (r);
605		765
606	redo:	766	redo:
607		767
608	// find next packet	768	// find next packet
…		…
622	}	782	}
623		783
624	rcvseq = (rcvseq + 1) & SEQNO_MASK;	784	rcvseq = (rcvseq + 1) & SEQNO_MASK;
625		785
626	if (!rcvdq.put (r->data, r->datalen))	786	if (!rcvdq.put (r->data, r->datalen))
		787	{
		788	slog (L_ERR, "DNS: !rcvdq.put (r->data, r->datalen)");
627	abort (); // MUST never overflow, can be caused by data corruption, TODO	789	abort (); // MUST never overflow, can be caused by data corruption, TODO
		790	}
628		791
629	while (vpn_packet *pkt = rcvdq.get ())	792	while (vpn_packet *pkt = rcvdq.get ())
630	{	793	{
631	sockinfo si;	794	sockinfo si;
632	si.host = 0; si.port = 0; si.prot = PROT_DNSv4;	795	si.host = 0x01010101; si.port = htons (c->conf->id); si.prot = PROT_DNSv4;
633		796
634	vpn->recv_vpn_packet (pkt, si);	797	vpn->recv_vpn_packet (pkt, si);
		798
		799	delete pkt;
635	}	800	}
636		801
637	// check for further packets	802	// check for further packets
638	goto redo;	803	goto redo;
639	}	804	}
640	}	805	}
641		806
642	dns_packet *	807	void
643	vpn::dnsv4_server (dns_packet *pkt)	808	vpn::dnsv4_server (dns_packet &pkt)
644	{	809	{
645	u16 flags = ntohs (pkt->flags);	810	u16 flags = ntohs (pkt.flags);
646		811
647	//memcpy (&((rep)[0]), &((pkt)[0]), pkt->len);
648	int offs = 6 * 2; // skip header	812	int offs = 6 * 2; // skip header
649		813
650	pkt->flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);	814	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);
651		815
652	if (0 == (flags & (FLAG_RESPONSE \| FLAG_OP_MASK \| FLAG_TC))	816	if (0 == (flags & (FLAG_RESPONSE \| FLAG_OP_MASK))
653	&& pkt->qdcount == htons (1))	817	&& pkt.qdcount == htons (1))
654	{	818	{
655	char qname[MAXSIZE];	819	char qname [MAXSIZE];
656	int qlen = pkt->decode_label ((char *)qname, MAXSIZE - offs, offs);	820	int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
657		821
658	u16 qtype = (pkt) [offs++] << 8; qtype \|= (pkt) [offs++];	822	u16 qtype = pkt [offs++] << 8; qtype \|= pkt [offs++];
659	u16 qclass = (pkt) [offs++] << 8; qclass \|= (pkt) [offs++];	823	u16 qclass = pkt [offs++] << 8; qclass \|= pkt [offs++];
660		824
661	pkt->qdcount = htons (1);	825	pkt.qdcount = htons (1);
662	pkt->ancount = 0;	826	pkt.ancount = 0;
663	pkt->nscount = 0; // should be self, as other nameservers reply like this	827	pkt.nscount = 0; // should be self, as other nameservers reply like this
664	pkt->arcount = 0; // a record for self, as other nameservers reply like this	828	pkt.arcount = 0; // a record for self, as other nameservers reply like this
665		829
666	pkt->flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_NXDOMAIN);	830	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_SERVFAIL);
667		831
668	int dlen = strlen (THISNODE->domain);	832	int dlen = strlen (THISNODE->domain);
669		833
670	if (qclass == RR_CLASS_IN	834	if (qclass == RR_CLASS_IN
671	&& (qtype == RR_TYPE_ANY \|\| qtype == RR_TYPE_TXT)
672	&& qlen > dlen + 1 + HDRSIZE	835	&& qlen > dlen + 1
673	&& !memcmp (qname + qlen - dlen - 1, THISNODE->domain, dlen))	836	&& !memcmp (qname + qlen - (dlen + 1), THISNODE->domain, dlen))
674	{	837	{
675	// correct class, domain: parse	838	// now generate reply
676	int client, seqno;	839	pkt.ancount = htons (1); // one answer RR
677	decode_header (qname, client, seqno);	840	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_OK);
678		841
679	u8 data[MAXSIZE];	842	if ((qtype == RR_TYPE_ANY
680	int datalen = cdc62.decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE));	843	\|\| qtype == RR_TYPE_TXT
681		844	\|\| qtype == RR_TYPE_NULL)
682	if (0 < client && client <= conns.size ())	845	&& qlen > dlen + 1 + HDRSIZE)
683	{	846	{
		847	// correct class, domain: parse
		848	int client, seqno;
		849	decode_header (qname, client, seqno);
		850
		851	u8 data[MAXSIZE];
		852	int datalen = cdc62.decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE));
		853
		854	if (0 < client && client <= conns.size ())
		855	{
684	connection *c = conns [client - 1];	856	connection *c = conns [client - 1];
685
686	if (!c->dns)
687	c->dns = new dns_connection (c);
688
689	dns_connection *dns = c->dns;	857	dns_connection *dns = c->dns;
		858	dns_rcv *rcv;
		859	bool in_seq;
690		860
		861	if (dns)
		862	{
691	for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); )	863	for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); )
692	if (SEQNO_EQ ((*i)->seqno, seqno))	864	if (SEQNO_EQ ((*i)->seqno, seqno))
		865	{
		866	// already seen that request: simply reply with the cached reply
		867	dns_rcv r = i;
		868
		869	slog (L_DEBUG, "DNS: duplicate packet received ID %d, SEQ %d", htons (r->pkt->id), seqno);
		870
		871	// refresh header & id, as the retry count could have changed
		872	memcpy (r->pkt->at (6 * 2 + 1), pkt.at (6 * 2 + 1), HDRSIZE);
		873	r->pkt->id = pkt.id;
		874
		875	memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len);
		876
		877	goto duplicate_request;
		878	}
		879
		880	in_seq = dns->rcvseq == seqno;
		881
		882	// new packet, queue
		883	rcv = new dns_rcv (seqno, data, datalen);
		884	dns->receive_rep (rcv);
		885	}
		886
693	{	887	{
694	// already seen that request: simply reply with the cached reply	888	pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section
695	dns_rcv r = i;
696		889
697	printf ("DUPLICATE %d\n", htons (r->pkt->id));//D	890	int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A;
		891	pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type
		892	pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
		893	pkt [offs++] = 0; pkt [offs++] = 0;
		894	pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL
698		895
699	memcpy (pkt->at (0), r->pkt->at (0), offs = r->pkt->len);	896	int rdlen_offs = offs += 2;
700	pkt->id = r->pkt->id;	897
701	goto duplicate_request;	898	if (dns)
		899	{
		900	int dlen = ntohs (dns->cfg.max_size) - offs;
		901
		902	// bind doesn't compress well, so reduce further by one label length
		903	dlen -= qlen;
		904
		905	// only put data into in-order sequence packets, if
		906	// we receive out-of-order packets we generate empty
		907	// replies
		908	while (dlen > 1 && !dns->snddq.empty () && in_seq)
		909	{
		910	int txtlen = dlen <= 255 ? dlen - 1 : 255;
		911
		912	if (txtlen > dns->snddq.size ())
		913	txtlen = dns->snddq.size ();
		914
		915	pkt[offs++] = txtlen;
		916	memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
		917	offs += txtlen;
		918	dns->snddq.remove (txtlen);
		919
		920	dlen -= txtlen + 1;
		921	}
		922
		923	// avoid empty TXT rdata
		924	if (offs == rdlen_offs)
		925	pkt[offs++] = 0;
		926
		927	slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
		928	}
		929	else
		930	{
		931	// send RST
		932	pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
		933	pkt [offs++] = CMD_IP_RST;
		934	}
		935
		936	int rdlen = offs - rdlen_offs;
		937
		938	pkt [rdlen_offs - 2] = rdlen >> 8;
		939	pkt [rdlen_offs - 1] = rdlen;
		940
		941	if (dns)
		942	{
		943	// now update dns_rcv copy
		944	rcv->pkt->len = offs;
		945	memcpy (rcv->pkt->at (0), pkt.at (0), offs);
		946	}
702	}	947	}
703		948
704	// new packet, queue	949	duplicate_request: ;
705	dns_rcv *rcv = new dns_rcv (seqno, data, datalen);	950	}
706	dns->receive_rep (rcv);	951	else
707
708	// now generate reply
709	pkt->ancount = htons (1); // one answer RR
710	pkt->flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_OK);	952	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);
		953	}
		954	else if (qtype == RR_TYPE_A
		955	&& qlen > dlen + 1 + cdc26.encode_len (sizeof (dns_cfg)))
		956	{
		957	dns_cfg cfg;
		958	cdc26.decode ((u8 *)&cfg, qname, cdc26.encode_len (sizeof (dns_cfg)));
		959	int client = ntohs (cfg.client);
711		960
712	(*pkt) [offs++] = 0xc0;
713	(pkt) [offs++] = 6 2; // same as in query section	961	pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section
714		962
715	(pkt) [offs++] = RR_TYPE_TXT >> 8; (pkt) [offs++] = RR_TYPE_TXT;	963	pkt [offs++] = RR_TYPE_A >> 8; pkt [offs++] = RR_TYPE_A; // type
716	(pkt) [offs++] = RR_CLASS_IN >> 8; (pkt) [offs++] = RR_CLASS_IN;	964	pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
717
718	(pkt) [offs++] = 0; (pkt) [offs++] = 0;	965	pkt [offs++] = 0; pkt [offs++] = 0;
719	(pkt) [offs++] = 0; (pkt) [offs++] = 0; // TTL	966	pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL
		967	pkt [offs++] = 0; pkt [offs++] = 4; // rdlength
720		968
721	int dlen = MAX_PKT_SIZE - offs - 2;	969	slog (L_INFO, _("DNS: client %d connects"), client);
722		970
723	// bind doesn't compress well, so reduce further by one label length	971	pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
724	dlen -= qlen;	972	pkt [offs++] = CMD_IP_REJ;
725		973
726	int rdlen_offs = offs += 2;	974	if (0 < client && client <= conns.size ())
727
728	while (dlen > 1 && !dns->snddq.empty ())
729	{	975	{
730	int txtlen = dlen <= 255 ? dlen - 1 : 255;	976	connection *c = conns [client - 1];
731		977
732	if (txtlen > dns->snddq.size ())	978	if (cfg.valid ())
733	txtlen = dns->snddq.size ();	979	{
		980	pkt [offs - 1] = CMD_IP_SYN;
734		981
735	(*pkt)[offs++] = txtlen;	982	delete c->dns;
736	memcpy (pkt->at (offs), dns->snddq.begin (), txtlen);	983	c->dns = new dns_connection (c);
737	offs += txtlen;	984	c->dns->cfg = cfg;
738	dns->snddq.remove (txtlen);	985	}
739
740	dlen -= txtlen + 1;
741	}	986	}
742
743	// avoid empty TXT rdata
744	if (offs == rdlen_offs)
745	(*pkt)[offs++] = 0;
746
747	int rdlen = offs - rdlen_offs;
748
749	(*pkt) [rdlen_offs - 2] = rdlen >> 8;
750	(*pkt) [rdlen_offs - 1] = rdlen;
751
752	// now update dns_rcv copy
753	rcv->pkt->len = offs;
754	memcpy (rcv->pkt->at (0), pkt->at (0), offs);
755
756	duplicate_request: ;
757	}	987	}
758	else
759	pkt->flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);
760	}	988	}
761		989
762	pkt->len = offs;	990	pkt.len = offs;
763	}	991	}
764
765	return pkt;
766	}	992	}
767		993
768	void	994	void
769	vpn::dnsv4_client (dns_packet *pkt)	995	vpn::dnsv4_client (dns_packet &pkt)
770	{	996	{
771	u16 flags = ntohs (pkt->flags);	997	u16 flags = ntohs (pkt.flags);
772	int offs = 6 * 2; // skip header	998	int offs = 6 * 2; // skip header
773		999
774	pkt->qdcount = ntohs (pkt->qdcount);	1000	pkt.qdcount = ntohs (pkt.qdcount);
775	pkt->ancount = ntohs (pkt->ancount);	1001	pkt.ancount = ntohs (pkt.ancount);
776		1002
777	// go through our request list and find the corresponding request	1003	// go through our request list and find the corresponding request
778	for (vector<dns_req *>::iterator i = dns_sndpq.begin ();	1004	for (vector<dns_snd *>::iterator i = dns_sndpq.begin ();
779	i != dns_sndpq.end ();	1005	i != dns_sndpq.end ();
780	++i)	1006	++i)
781	if ((*i)->pkt->id == pkt->id)	1007	if ((*i)->pkt->id == pkt.id)
782	{	1008	{
783	dns_connection dns = (i)->dns;	1009	dns_connection dns = (i)->dns;
		1010	connection *c = dns->c;
784	int seqno = (*i)->seqno;	1011	int seqno = (*i)->seqno;
785	u8 data[MAXSIZE], *datap = data;	1012	u8 data[MAXSIZE], *datap = data;
786		1013
		1014	if ((*i)->retry)
		1015	{
		1016	dns->send_interval *= 1.01;
		1017	if (dns->send_interval > MAX_SEND_INTERVAL)
		1018	dns->send_interval = MAX_SEND_INTERVAL;
		1019	}
		1020	else
		1021	{
		1022	#if 0
		1023	dns->send_interval *= 0.999;
		1024	#endif
		1025	// the latency surely puts an upper bound on
		1026	// the minimum send interval
		1027	double latency = NOW - (*i)->sent;
		1028
		1029	if (latency < dns->min_latency)
		1030	dns->min_latency = latency;
		1031
		1032	if (dns->send_interval > dns->min_latency * LATENCY_FACTOR)
		1033	dns->send_interval = dns->min_latency * LATENCY_FACTOR;
		1034
		1035	if (dns->send_interval < MIN_SEND_INTERVAL)
		1036	dns->send_interval = MIN_SEND_INTERVAL;
		1037	}
		1038
787	delete *i;	1039	delete *i;
788	dns_sndpq.erase (i);	1040	dns_sndpq.erase (i);
789		1041
790	if (flags & FLAG_RESPONSE && !(flags & (FLAG_OP_MASK \| FLAG_TC)))	1042	if (flags & FLAG_RESPONSE && !(flags & FLAG_OP_MASK))
791	{	1043	{
792	char qname[MAXSIZE];	1044	char qname[MAXSIZE];
793		1045
794	while (pkt->qdcount-- && offs < MAXSIZE - 4)	1046	while (pkt.qdcount-- && offs < MAXSIZE - 4)
795	{	1047	{
796	int qlen = pkt->decode_label ((char *)qname, MAXSIZE - offs, offs);	1048	int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
797	offs += 4; // skip qtype, qclass	1049	offs += 4; // skip qtype, qclass
798	}	1050	}
799		1051
800	while (pkt->ancount-- && offs < MAXSIZE - 10 && datap)	1052	while (pkt.ancount-- && offs < MAXSIZE - 10 && datap)
801	{	1053	{
802	int qlen = pkt->decode_label ((char *)qname, MAXSIZE - offs, offs);	1054	int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
803		1055
804	u16 qtype = (pkt) [offs++] << 8; qtype \|= (pkt) [offs++];	1056	u16 qtype = pkt [offs++] << 8; qtype \|= pkt [offs++];
805	u16 qclass = (pkt) [offs++] << 8; qclass \|= (pkt) [offs++];	1057	u16 qclass = pkt [offs++] << 8; qclass \|= pkt [offs++];
806	u32 ttl = (*pkt) [offs++] << 24;	1058	u32 ttl = pkt [offs++] << 24;
807	ttl \|= (*pkt) [offs++] << 16;	1059	ttl \|= pkt [offs++] << 16;
808	ttl \|= (*pkt) [offs++] << 8;	1060	ttl \|= pkt [offs++] << 8;
809	ttl \|= (*pkt) [offs++];	1061	ttl \|= pkt [offs++];
810
811	u16 rdlen = (pkt) [offs++] << 8; rdlen \|= (pkt) [offs++];	1062	u16 rdlen = pkt [offs++] << 8; rdlen \|= pkt [offs++];
812		1063
813	if (rdlen <= MAXSIZE - offs)	1064	if (qtype == RR_TYPE_NULL \|\| qtype == RR_TYPE_TXT)
814	{	1065	{
815	// decode bytes, finally	1066	if (rdlen <= MAXSIZE - offs)
816
817	while (rdlen)
818	{	1067	{
		1068	// decode bytes, finally
		1069
		1070	while (rdlen)
		1071	{
819	int txtlen = (*pkt) [offs++];	1072	int txtlen = pkt [offs++];
820		1073
821	assert (txtlen + offs < MAXSIZE - 1);	1074	assert (txtlen + offs < MAXSIZE - 1);
822		1075
823	memcpy (datap, pkt->at (offs), txtlen);	1076	memcpy (datap, pkt.at (offs), txtlen);
824	datap += txtlen; offs += txtlen;	1077	datap += txtlen; offs += txtlen;
825		1078
826	rdlen -= txtlen + 1;	1079	rdlen -= txtlen + 1;
		1080	}
827	}	1081	}
828	}	1082	}
		1083	else if (qtype == RR_TYPE_A)
		1084	{
		1085	u8 ip [4];
		1086
		1087	ip [0] = pkt [offs++];
		1088	ip [1] = pkt [offs++];
		1089	ip [2] = pkt [offs++];
		1090	ip [3] = pkt [offs++];
		1091
		1092	if (ip [0] == CMD_IP_1
		1093	&& ip [1] == CMD_IP_2
		1094	&& ip [2] == CMD_IP_3)
		1095	{
		1096	slog (L_TRACE, _("DNS: got tunnel meta command %02x"), ip [3]);
		1097
		1098	if (ip [3] == CMD_IP_RST)
		1099	{
		1100	slog (L_DEBUG, _("DNS: got tunnel RST request"));
		1101
		1102	delete dns; c->dns = 0;
		1103
		1104	return;
		1105	}
		1106	else if (ip [3] == CMD_IP_SYN)
		1107	{
		1108	slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us."));
		1109	dns->established = true;
		1110	}
		1111	else if (ip [3] == CMD_IP_REJ)
		1112	{
		1113	slog (L_DEBUG, _("DNS: got tunnel REJ reply, server does not like us, aborting."));
		1114	abort ();
		1115	}
		1116	else
		1117	slog (L_INFO, _("DNS: got unknown meta command %02x"), ip [3]);
		1118	}
		1119	else
		1120	slog (L_INFO, _("DNS: got spurious a record %d.%d.%d.%d"),
		1121	ip [0], ip [1], ip [2], ip [3]);
		1122
		1123	return;
		1124	}
829		1125
830	int client, rseqno;	1126	int client, rseqno;
831	decode_header (qname, client, rseqno);	1127	decode_header (qname, client, rseqno);
832		1128
833	if (client != THISNODE->id)	1129	if (client != THISNODE->id)
834	{	1130	{
835	slog (L_INFO, _("got dns tunnel response with wrong clientid, ignoring"));	1131	slog (L_INFO, _("DNS: got dns tunnel response with wrong clientid, ignoring"));
836	datap = 0;	1132	datap = 0;
837	}	1133	}
838	else if (rseqno != seqno)	1134	else if (rseqno != seqno)
839	{	1135	{
840	slog (L_DEBUG, _("got dns tunnel response with wrong seqno, badly caching nameserver?"));	1136	slog (L_DEBUG, _("DNS: got dns tunnel response with wrong seqno, badly caching nameserver?"));
841	datap = 0;	1137	datap = 0;
842	}	1138	}
843	}	1139	}
844	}	1140	}
845		1141
…		…
847	if (datap)	1143	if (datap)
848	dns->receive_rep (new dns_rcv (seqno, data, datap - data));	1144	dns->receive_rep (new dns_rcv (seqno, data, datap - data));
849		1145
850	break;	1146	break;
851	}	1147	}
852
853	delete pkt;
854	}	1148	}
855		1149
856	void	1150	void
857	vpn::dnsv4_ev (io_watcher &w, short revents)	1151	vpn::dnsv4_ev (io_watcher &w, short revents)
858	{	1152	{
…		…
860	{	1154	{
861	dns_packet *pkt = new dns_packet;	1155	dns_packet *pkt = new dns_packet;
862	struct sockaddr_in sa;	1156	struct sockaddr_in sa;
863	socklen_t sa_len = sizeof (sa);	1157	socklen_t sa_len = sizeof (sa);
864		1158
865	pkt->len = recvfrom (w.fd, &((pkt)[0]), MAXSIZE, 0, (sockaddr )&sa, &sa_len);	1159	pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len);
866		1160
867	if (pkt->len > 0)	1161	if (pkt->len > 0)
868	{	1162	{
869	if (pkt->flags & htons (FLAG_TC))	1163	if (ntohs (pkt->flags) & FLAG_RESPONSE)
		1164	dnsv4_client (*pkt);
		1165	else
870	{	1166	{
871	slog (L_WARN, _("DNS request/response truncated, check protocol settings."));	1167	dnsv4_server (*pkt);
872	//TODO connection reset	1168	sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len);
873	}	1169	}
874		1170
875	if (THISNODE->dns_port)	1171	delete pkt;
876	{
877	pkt = dnsv4_server (pkt);
878	sendto (w.fd, &((pkt)[0]), pkt->len, 0, (sockaddr )&sa, sa_len);
879	}
880	else
881	dnsv4_client (pkt);
882	}	1172	}
883	}	1173	}
884	}	1174	}
885		1175
886	bool	1176	bool
887	connection::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)	1177	vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
888	{	1178	{
		1179	int client = ntohs (si.port);
		1180
		1181	assert (0 < client && client <= conns.size ());
		1182
		1183	connection *c = conns [client - 1];
		1184
889	if (!dns)	1185	if (!c->dns)
890	dns = new dns_connection (this);	1186	c->dns = new dns_connection (c);
891		1187
892	if (!dns->snddq.put (pkt))	1188	if (!c->dns->snddq.put (pkt))
893	return false;	1189	return false;
894		1190
895	// start timer if neccessary
896	if (!THISNODE->dns_port && !dns->tw.active)
897	dns->tw.trigger ();	1191	c->dns->tw.trigger ();
898		1192
899	return true;	1193	return true;
900	}	1194	}
		1195
		1196	void
		1197	connection::dnsv4_reset_connection ()
		1198	{
		1199	//delete dns; dns = 0; //TODO
		1200	}
		1201
		1202	#define NEXT(w) do { if (next > (w)) next = w; } while (0)
901		1203
902	void	1204	void
903	dns_connection::time_cb (time_watcher &w)	1205	dns_connection::time_cb (time_watcher &w)
904	{	1206	{
		1207	// servers have to be polled
		1208	if (THISNODE->dns_port)
		1209	return;
		1210
905	// check for timeouts and (re)transmit	1211	// check for timeouts and (re)transmit
906	tstamp next = NOW + 60;	1212	tstamp next = NOW + poll_interval;
907	dns_req *send = 0;	1213	dns_snd *send = 0;
908		1214
909	for (vector<dns_req *>::iterator i = vpn->dns_sndpq.begin ();	1215	for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin ();
910	i != vpn->dns_sndpq.end ();	1216	i != vpn->dns_sndpq.end ();
911	++i)	1217	++i)
912	{	1218	{
913	dns_req r = i;	1219	dns_snd r = i;
914		1220
915	if (r->next <= NOW)	1221	if (r->timeout <= NOW)
916	{	1222	{
917	if (!send)	1223	if (!send)
918	{	1224	{
919	send = r;	1225	send = r;
920		1226
921	if (r->retry)//D
922	printf ("req %d:%d, retry %d\n", r->seqno, r->pkt->id, r->retry);
923	r->retry++;	1227	r->retry++;
924	r->next = NOW + r->retry;	1228	r->timeout = NOW + (r->retry * min_latency * 8.);
		1229
		1230	// the following code changes the query section a bit, forcing
		1231	// the forwarder to generate a new request
		1232	if (r->stdhdr)
		1233	{
		1234	//printf ("reencoded header for ID %d retry %d:%d:%d (%p)\n", htons (r->pkt->id), THISNODE->id, r->seqno, r->retry);
		1235	//encode_header ((char )r->pkt->at (6 2 + 1), THISNODE->id, r->seqno, r->retry);
		1236	}
925	}	1237	}
926	}	1238	}
927		1239	else
928	if (r->next < next)	1240	NEXT (r->timeout);
929	next = r->next;
930	}	1241	}
931		1242
932	if (!send	1243	if (!send)
		1244	{
		1245	// generate a new packet, if wise
		1246
		1247	if (!established)
		1248	{
		1249	if (vpn->dns_sndpq.empty ())
		1250	{
		1251	send = new dns_snd (this);
		1252
		1253	cfg.reset (THISNODE->id);
		1254	send->gen_syn_req ();
		1255	}
		1256	}
933	&& vpn->dns_sndpq.size () < MAX_OUTSTANDING)	1257	else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING
934	{	1258	&& !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
		1259	{
		1260	if (last_sent + send_interval <= NOW)
		1261	{
		1262	//printf ("sending data request etc.\n"); //D
		1263	if (!snddq.empty () \|\| last_received + 1. > NOW)
		1264	{
		1265	poll_interval = send_interval;
		1266	NEXT (NOW + send_interval);
		1267	}
		1268
935	send = new dns_req (this);	1269	send = new dns_snd (this);
936	send->gen_stream_req (sndseq, snddq);	1270	send->gen_stream_req (sndseq, snddq);
		1271	send->timeout = NOW + min_latency * 8.;
		1272
		1273	sndseq = (sndseq + 1) & SEQNO_MASK;
		1274	}
		1275	else
		1276	NEXT (last_sent + send_interval);
		1277	}
		1278
		1279	if (send)
937	vpn->dns_sndpq.push_back (send);	1280	vpn->dns_sndpq.push_back (send);
938
939	sndseq = (sndseq + 1) & SEQNO_MASK;
940	}	1281	}
941
942	tstamp min_next = NOW + (1. / (tstamp)MAX_RATE);
943		1282
944	if (send)	1283	if (send)
945	{	1284	{
946	dns_packet *pkt = send->pkt;	1285	last_sent = NOW;
947		1286	sendto (vpn->dnsv4_fd,
948	next = min_next;	1287	send->pkt->at (0), send->pkt->len, 0,
949
950	sendto (vpn->dnsv4_fd, &((*pkt)[0]), pkt->len, 0,
951	vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());	1288	vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
952	}	1289	}
953	else if (next < min_next)	1290
954	next = min_next;	1291	slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)",
		1292	poll_interval, send_interval, next - NOW,
		1293	vpn->dns_sndpq.size (), snddq.size (),
		1294	rcvpq.size ());
		1295
		1296	// TODO: no idea when this happens, but when next < NOW, we have a problem
		1297	if (next < NOW + 0.001)
		1298	next = NOW + 0.1;
955		1299
956	w.start (next);	1300	w.start (next);
957	}	1301	}
958		1302
959	#endif	1303	#endif

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Comparing gvpe/src/vpn_dns.C (file contents): Revision 1.9 by pcg, Fri Mar 4 04:52:38 2005 UTC vs. Revision 1.29 by pcg, Sun Mar 13 12:40:20 2005 UTC

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Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.9 by pcg, Fri Mar 4 04:52:38 2005 UTC vs.
Revision 1.29 by pcg, Sun Mar 13 12:40:20 2005 UTC