[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 1.31 by pcg, Tue Mar 15 11:43:38 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 MAX_POLL_INTERVAL 5. // how often to poll minimally when the server has no data
49	#define MAX_RETRY 6.	50	#define ACTIVITY_INTERVAL 5.
50		51
		52	#define TIMEOUT_FACTOR 2.
		53
		54	#define INITIAL_TIMEOUT 0.1 // retry timeouts
		55	#define INITIAL_SYN_TIMEOUT 10. // retry timeout for initial syn
		56
		57	#define MIN_SEND_INTERVAL 0.001 // wait at least this time between sending requests
		58	#define MAX_SEND_INTERVAL 2. // optimistic?
		59
		60	#define LATENCY_FACTOR 0.5 // RTT * LATENCY_FACTOR == sending rate
51	#define MAX_OUTSTANDING 400 // max. outstanding requests	61	#define MAX_OUTSTANDING 100 // max. outstanding requests
52	#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING	62	#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	63	#define MAX_BACKLOG (32*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE
55		64
56	#define MAX_DOMAIN_SIZE 220 // 255 is legal limit, but bind doesn't compress well	65	#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	66	// 240 leaves about 4 bytes of server reply data
58	// every two request byte sless give room for one reply byte	67	// every two request bytes less give room for one reply byte
59		68
60	#define SEQNO_MASK 0xffff	69	#define SEQNO_MASK 0x0fff
61	#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )	70	#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )
62		71
63	#define MAX_LBL_SIZE 63	72	#define MAX_LBL_SIZE 63
64	#define MAX_PKT_SIZE 512	73	#define MAX_PKT_SIZE 512
65		74
		75	#define RR_TYPE_A 1
		76	#define RR_TYPE_NULL 10
66	#define RR_TYPE_TXT 16	77	#define RR_TYPE_TXT 16
67	#define RR_TYPE_ANY 255	78	#define RR_TYPE_ANY 255
		79
68	#define RR_CLASS_IN 1	80	#define RR_CLASS_IN 1
		81
		82	#define CMD_IP_1 207
		83	#define CMD_IP_2 46
		84	#define CMD_IP_3 236
		85	#define CMD_IP_RST 29
		86	#define CMD_IP_SYN 113
		87	#define CMD_IP_REJ 32
69		88
70	// works for cmaps up to 255 (not 256!)	89	// works for cmaps up to 255 (not 256!)
71	struct charmap	90	struct charmap
72	{	91	{
73	enum { INVALID = (u8)255 };	92	enum { INVALID = (u8)255 };
…		…
153	return dec_len [len];	172	return dec_len [len];
154	}	173	}
155		174
156	unsigned int basecoder::encode (char dst, u8 src, unsigned int len)	175	unsigned int basecoder::encode (char dst, u8 src, unsigned int len)
157	{	176	{
158	if (!len)	177	if (!len \|\| len > MAX_DEC_LEN)
159	return 0;	178	return 0;
160		179
161	int elen = encode_len (len);	180	int elen = encode_len (len);
162		181
163	mp_limb_t m [MAX_LIMBS];	182	mp_limb_t m [MAX_LIMBS];
…		…
182	return elen;	201	return elen;
183	}	202	}
184		203
185	unsigned int basecoder::decode (u8 dst, char src, unsigned int len)	204	unsigned int basecoder::decode (u8 dst, char src, unsigned int len)
186	{	205	{
187	if (!len)	206	if (!len \|\| len > MAX_ENC_LEN)
188	return 0;	207	return 0;
189		208
190	u8 src_ [MAX_ENC_LEN];	209	u8 src_ [MAX_ENC_LEN];
191	unsigned int elen = 0;	210	unsigned int elen = 0;
192		211
…		…
239	}	258	}
240	abort ();	259	abort ();
241	}	260	}
242	#endif	261	#endif
243		262
244	// the following sequence has been crafted to	263	//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");	264	//static basecoder cdc63 ("_dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI");
250	static basecoder cdc62 ("dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI");	265	static basecoder cdc62 ("dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI");
251	//static basecoder cdc36 ("dphzr06qmjkb34tsvl81xaef92wgyo57ucni"); // unused as of yet	266	//static basecoder cdc36 ("dphzr06qmjkb34tsvl81xaef92wgyo57ucni"); // unused as of yet
252	static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO");	267	static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO");
253		268
254	/////////////////////////////////////////////////////////////////////////////	269	/////////////////////////////////////////////////////////////////////////////
255		270
256	#define HDRSIZE 6	271	#define HDRSIZE 6
257		272
258	inline void encode_header (char *data, int clientid, int seqno)	273	inline void encode_header (char *data, int clientid, int seqno, int retry = 0)
259	{	274	{
260	u8 hdr[3] = { clientid, seqno >> 8, seqno };	275	seqno &= SEQNO_MASK;
		276
		277	u8 hdr[3] = {
		278	clientid,
		279	(seqno >> 8) \| (retry << 6),
		280	seqno,
		281	};
261		282
262	assert (clientid < 256);	283	assert (clientid < 256);
263		284
264	cdc26.encode (data, hdr, 3);	285	cdc26.encode (data, hdr, 3);
265	}	286	}
…		…
269	u8 hdr[3];	290	u8 hdr[3];
270		291
271	cdc26.decode (hdr, data, HDRSIZE);	292	cdc26.decode (hdr, data, HDRSIZE);
272		293
273	clientid = hdr[0];	294	clientid = hdr[0];
274	seqno = (hdr[1] << 8) \| hdr[2];	295	seqno = ((hdr[1] << 8) \| hdr[2]) & SEQNO_MASK;
275	}	296	}
276		297
277	/////////////////////////////////////////////////////////////////////////////	298	/////////////////////////////////////////////////////////////////////////////
278		299
279	struct byte_stream	300	struct byte_stream
…		…
308	}	329	}
309		330
310	void byte_stream::remove (int count)	331	void byte_stream::remove (int count)
311	{	332	{
312	if (count > fill)	333	if (count > fill)
313	abort ();	334	assert (count <= fill);
314		335
315	memmove (data, data + count, fill -= count);	336	memmove (data, data + count, fill -= count);
316	}	337	}
317		338
318	bool byte_stream::put (u8 *data, unsigned int datalen)	339	bool byte_stream::put (u8 *data, unsigned int datalen)
…		…
331	return false;	352	return false;
332		353
333	data [fill++] = pkt->len >> 8;	354	data [fill++] = pkt->len >> 8;
334	data [fill++] = pkt->len;	355	data [fill++] = pkt->len;
335		356
336	memcpy (data + fill, &((*pkt)[0]), pkt->len); fill += pkt->len;	357	memcpy (data + fill, pkt->at (0), pkt->len); fill += pkt->len;
337		358
338	return true;	359	return true;
339	}	360	}
340		361
341	vpn_packet *byte_stream::get ()	362	vpn_packet *byte_stream::get ()
342	{	363	{
		364	unsigned int len;
		365
		366	for (;;)
		367	{
343	int len = (data [0] << 8) \| data [1];	368	len = (data [0] << 8) \| data [1];
344		369
345	if (len > MAXSIZE && fill >= 2)	370	if (len <= MAXSIZE \|\| fill < 2)
346	abort (); // TODO handle this gracefully, connection reset	371	break;
347		372
		373	// TODO: handle this better than skipping, e.g. by reset
		374	slog (L_DEBUG, _("DNS: corrupted packet stream skipping a byte..."));
		375	remove (1);
		376	}
		377
348	if (fill < len + 2)	378	if (fill < len + 2)
349	return 0;	379	return 0;
350		380
351	vpn_packet *pkt = new vpn_packet;	381	vpn_packet *pkt = new vpn_packet;
352		382
353	pkt->len = len;	383	pkt->len = len;
354	memcpy (&((*pkt)[0]), data + 2, len);	384	memcpy (pkt->at (0), data + 2, len);
355	remove (len + 2);	385	remove (len + 2);
356		386
357	return pkt;	387	return pkt;
358	}	388	}
359		389
…		…
376	#define FLAG_RCODE_REFUSED ( 5 << 0)	406	#define FLAG_RCODE_REFUSED ( 5 << 0)
377		407
378	#define DEFAULT_CLIENT_FLAGS (FLAG_QUERY \| FLAG_OP_QUERY \| FLAG_RD)	408	#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)	409	#define DEFAULT_SERVER_FLAGS (FLAG_RESPONSE \| FLAG_OP_QUERY \| FLAG_AA \| FLAG_RD \| FLAG_RA)
380		410
		411	struct dns_cfg
		412	{
		413	static int next_uid;
		414
		415	u8 id1, id2, id3, id4;
		416
		417	u8 version;
		418	u8 flags;
		419	u8 rrtype;
		420	u8 def_ttl;
		421
		422	u16 client;
		423	u16 uid; // to make request unique
		424
		425	u16 max_size;
		426	u8 seq_cdc;
		427	u8 req_cdc;
		428
		429	u8 rep_cdc;
		430	u8 delay; // time in 0.01s units that the server may delay replying packets
		431	u8 r3, r4;
		432
		433	u8 r5, r6, r7, r8;
		434
		435	void reset (int clientid);
		436	bool valid ();
		437	};
		438
		439	int dns_cfg::next_uid;
		440
		441	void dns_cfg::reset (int clientid)
		442	{
		443	id1 = 'G';
		444	id2 = 'V';
		445	id3 = 'P';
		446	id4 = 'E';
		447
		448	version = 1;
		449
		450	rrtype = RR_TYPE_TXT;
		451	flags = 0;
		452	def_ttl = 0;
		453	seq_cdc = 26;
		454	req_cdc = 62;
		455	rep_cdc = 0;
		456	max_size = htons (MAX_PKT_SIZE);
		457	client = htons (clientid);
		458	uid = next_uid++;
		459	delay = 0;
		460
		461	r3 = r4 = 0;
		462	r4 = r5 = r6 = r7 = 0;
		463	}
		464
		465	bool dns_cfg::valid ()
		466	{
		467	return id1 == 'G'
		468	&& id2 == 'V'
		469	&& id3 == 'P'
		470	&& id4 == 'E'
		471	&& seq_cdc == 26
		472	&& req_cdc == 62
		473	&& rep_cdc == 0
		474	&& version == 1;
		475	}
		476
381	struct dns_packet : net_packet	477	struct dns_packet : net_packet
382	{	478	{
383	u16 id;	479	u16 id;
384	u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4	480	u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4
385	u16 qdcount, ancount, nscount, arcount;	481	u16 qdcount, ancount, nscount, arcount;
386		482
387	u8 data[MAXSIZE - 6 * 2];	483	u8 data [MAXSIZE - 6 * 2];
388		484
389	int decode_label (char *data, int size, int &offs);	485	int decode_label (char *data, int size, int &offs);
390	};	486	};
391		487
392	int dns_packet::decode_label (char *data, int size, int &offs)	488	int dns_packet::decode_label (char *data, int size, int &offs)
…		…
423	return data - orig;	519	return data - orig;
424	}	520	}
425		521
426	/////////////////////////////////////////////////////////////////////////////	522	/////////////////////////////////////////////////////////////////////////////
427		523
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	524	static u16 dns_id = 0; // TODO: should be per-vpn
441		525
442	static u16 next_id ()	526	static u16 next_id ()
443	{	527	{
		528	if (!dns_id)
		529	dns_id = time (0);
		530
444	// the simplest lsfr with periodicity 65535 i could find	531	// the simplest lsfr with periodicity 65535 i could find
445	dns_id = (dns_id << 1)	532	dns_id = (dns_id << 1)
446	\| (((dns_id >> 1)	533	\| (((dns_id >> 1)
447	^ (dns_id >> 2)	534	^ (dns_id >> 2)
448	^ (dns_id >> 4)	535	^ (dns_id >> 4)
449	^ (dns_id >> 15)) & 1);	536	^ (dns_id >> 15)) & 1);
450		537
451	return dns_id;	538	return dns_id;
452	}	539	}
453		540
		541	struct dns_rcv;
		542	struct dns_snd;
		543
		544	struct dns_connection
		545	{
		546	connection *c;
		547	struct vpn *vpn;
		548
		549	dns_cfg cfg;
		550
		551	bool established;
		552
		553	tstamp last_received;
		554	tstamp last_sent;
		555	double min_latency;
		556	double poll_interval, send_interval;
		557
		558	vector<dns_rcv *> rcvpq;
		559
		560	byte_stream rcvdq; int rcvseq; int repseq;
		561	byte_stream snddq; int sndseq;
		562
		563	void time_cb (time_watcher &w); time_watcher tw;
		564	void receive_rep (dns_rcv *r);
		565
		566	dns_connection (connection *c);
		567	~dns_connection ();
		568	};
		569
		570	struct dns_snd
		571	{
		572	dns_packet *pkt;
		573	tstamp timeout, sent;
		574	int retry;
		575	struct dns_connection *dns;
		576	int seqno;
		577	bool stdhdr;
		578
		579	void gen_stream_req (int seqno, byte_stream &stream);
		580	void gen_syn_req ();
		581
		582	dns_snd (dns_connection *dns);
		583	~dns_snd ();
		584	};
		585
454	dns_req::dns_req (dns_connection *dns)	586	dns_snd::dns_snd (dns_connection *dns)
455	: dns (dns)	587	: dns (dns)
456	{	588	{
457	next = 0;	589	timeout = 0;
458	retry = 0;	590	retry = 0;
		591	seqno = 0;
		592	sent = NOW;
		593	stdhdr = false;
459		594
460	pkt = new dns_packet;	595	pkt = new dns_packet;
461		596
462	pkt->id = next_id ();	597	pkt->id = next_id ();
463	}	598	}
464		599
		600	dns_snd::~dns_snd ()
		601	{
		602	delete pkt;
		603	}
		604
		605	static void append_domain (dns_packet &pkt, int &offs, const char *domain)
		606	{
		607	// add tunnel domain
		608	for (;;)
		609	{
		610	const char *end = strchr (domain, '.');
		611
		612	if (!end)
		613	end = domain + strlen (domain);
		614
		615	int len = end - domain;
		616
		617	pkt [offs++] = len;
		618	memcpy (pkt.at (offs), domain, len);
		619	offs += len;
		620
		621	if (!*end)
		622	break;
		623
		624	domain = end + 1;
		625	}
		626	}
		627
465	void dns_req::gen_stream_req (int seqno, byte_stream &stream)	628	void dns_snd::gen_stream_req (int seqno, byte_stream &stream)
466	{	629	{
		630	stdhdr = true;
467	this->seqno = seqno;	631	this->seqno = seqno;
		632
		633	timeout = NOW + INITIAL_TIMEOUT;
468		634
469	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);	635	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
470	pkt->qdcount = htons (1);	636	pkt->qdcount = htons (1);
471		637
472	int offs = 6*2;	638	int offs = 6*2;
473	int dlen = MAX_DOMAIN_SIZE - (strlen (THISNODE->domain) + 2);	639	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,	640	// 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	641	// so we need to have space for 2*MAX_DOMAIN_SIZE + header + extra
476		642
477	char enc[256], *encp = enc;	643	char enc[256], *encp = enc;
478	encode_header (enc, THISNODE->id, seqno);	644	encode_header (enc, THISNODE->id, seqno);
…		…
496	encp += lbllen;	662	encp += lbllen;
497		663
498	enclen -= lbllen;	664	enclen -= lbllen;
499	}	665	}
500		666
501	const char *suffix = THISNODE->domain;	667	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		668
523	(*pkt)[offs++] = 0;	669	(*pkt)[offs++] = 0;
524	(pkt)[offs++] = RR_TYPE_ANY >> 8; (pkt)[offs++] = RR_TYPE_ANY;	670	(pkt)[offs++] = RR_TYPE_ANY >> 8; (pkt)[offs++] = RR_TYPE_ANY;
		671	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;
		672
		673	pkt->len = offs;
		674	}
		675
		676	void dns_snd::gen_syn_req ()
		677	{
		678	timeout = NOW + INITIAL_SYN_TIMEOUT;
		679
		680	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
		681	pkt->qdcount = htons (1);
		682
		683	int offs = 6 * 2;
		684
		685	int elen = cdc26.encode ((char )pkt->at (offs + 1), (u8 )&dns->cfg, sizeof (dns_cfg));
		686
		687	assert (elen <= MAX_LBL_SIZE);
		688
		689	(*pkt)[offs] = elen;
		690	offs += elen + 1;
		691	append_domain (*pkt, offs, dns->c->conf->domain);
		692
		693	(*pkt)[offs++] = 0;
		694	(pkt)[offs++] = RR_TYPE_A >> 8; (pkt)[offs++] = RR_TYPE_A;
525	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;	695	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;
526		696
527	pkt->len = offs;	697	pkt->len = offs;
528	}	698	}
529		699
…		…
549	delete pkt;	719	delete pkt;
550	}	720	}
551		721
552	/////////////////////////////////////////////////////////////////////////////	722	/////////////////////////////////////////////////////////////////////////////
553		723
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)	724	dns_connection::dns_connection (connection *c)
575	: c (c)	725	: c (c)
576	, rcvdq (MAX_BACKLOG * 2)	726	, rcvdq (MAX_BACKLOG * 2)
577	, snddq (MAX_BACKLOG * 2)	727	, snddq (MAX_BACKLOG)
578	, tw (this, &dns_connection::time_cb)	728	, tw (this, &dns_connection::time_cb)
579	{	729	{
580	vpn = c->vpn;	730	vpn = c->vpn;
581		731
		732	established = false;
		733
582	rcvseq = sndseq = 0;	734	rcvseq = repseq = sndseq = 0;
		735
		736	last_sent = last_received = 0;
		737	poll_interval = 0.5; // starting here
		738	send_interval = 0.5; // starting rate
		739	min_latency = INITIAL_TIMEOUT;
583	}	740	}
584		741
585	dns_connection::~dns_connection ()	742	dns_connection::~dns_connection ()
586	{	743	{
587	for (vector<dns_rcv *>::iterator i = rcvpq.begin ();	744	for (vector<dns_rcv *>::iterator i = rcvpq.begin ();
588	i != rcvpq.end ();	745	i != rcvpq.end ();
589	++i)	746	++i)
590	delete *i;	747	delete *i;
591	}	748	}
592		749
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)	750	void dns_connection::receive_rep (dns_rcv *r)
603	{	751	{
		752	if (r->datalen)
		753	{
		754	last_received = NOW;
		755	tw.trigger ();
		756
		757	poll_interval = send_interval;
		758	}
		759	else
		760	{
		761	poll_interval *= 1.5;
		762
		763	if (poll_interval > MAX_POLL_INTERVAL)
		764	poll_interval = MAX_POLL_INTERVAL;
		765	}
		766
604	rcvpq.push_back (r);	767	rcvpq.push_back (r);
605		768
606	redo:	769	redo:
607		770
608	// find next packet	771	// find next packet
…		…
622	}	785	}
623		786
624	rcvseq = (rcvseq + 1) & SEQNO_MASK;	787	rcvseq = (rcvseq + 1) & SEQNO_MASK;
625		788
626	if (!rcvdq.put (r->data, r->datalen))	789	if (!rcvdq.put (r->data, r->datalen))
		790	{
		791	slog (L_ERR, "DNS: !rcvdq.put (r->data, r->datalen)");
627	abort (); // MUST never overflow, can be caused by data corruption, TODO	792	abort (); // MUST never overflow, can be caused by data corruption, TODO
		793	}
628		794
629	while (vpn_packet *pkt = rcvdq.get ())	795	while (vpn_packet *pkt = rcvdq.get ())
630	{	796	{
631	sockinfo si;	797	sockinfo si;
632	si.host = 0; si.port = 0; si.prot = PROT_DNSv4;	798	si.host = 0x01010101; si.port = htons (c->conf->id); si.prot = PROT_DNSv4;
633		799
634	vpn->recv_vpn_packet (pkt, si);	800	vpn->recv_vpn_packet (pkt, si);
		801
		802	delete pkt;
635	}	803	}
636		804
637	// check for further packets	805	// check for further packets
638	goto redo;	806	goto redo;
639	}	807	}
640	}	808	}
641		809
642	dns_packet *	810	void
643	vpn::dnsv4_server (dns_packet *pkt)	811	vpn::dnsv4_server (dns_packet &pkt)
644	{	812	{
645	u16 flags = ntohs (pkt->flags);	813	u16 flags = ntohs (pkt.flags);
646		814
647	//memcpy (&((rep)[0]), &((pkt)[0]), pkt->len);
648	int offs = 6 * 2; // skip header	815	int offs = 6 * 2; // skip header
649		816
650	pkt->flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);	817	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);
651		818
652	if (0 == (flags & (FLAG_RESPONSE \| FLAG_OP_MASK \| FLAG_TC))	819	if (0 == (flags & (FLAG_RESPONSE \| FLAG_OP_MASK))
653	&& pkt->qdcount == htons (1))	820	&& pkt.qdcount == htons (1))
654	{	821	{
655	char qname[MAXSIZE];	822	char qname [MAXSIZE];
656	int qlen = pkt->decode_label ((char *)qname, MAXSIZE - offs, offs);	823	int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
657		824
658	u16 qtype = (pkt) [offs++] << 8; qtype \|= (pkt) [offs++];	825	u16 qtype = pkt [offs++] << 8; qtype \|= pkt [offs++];
659	u16 qclass = (pkt) [offs++] << 8; qclass \|= (pkt) [offs++];	826	u16 qclass = pkt [offs++] << 8; qclass \|= pkt [offs++];
660		827
661	pkt->qdcount = htons (1);	828	pkt.qdcount = htons (1);
662	pkt->ancount = 0;	829	pkt.ancount = 0;
663	pkt->nscount = 0; // should be self, as other nameservers reply like this	830	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	831	pkt.arcount = 0; // a record for self, as other nameservers reply like this
665		832
666	pkt->flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_NXDOMAIN);	833	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_SERVFAIL);
667		834
668	int dlen = strlen (THISNODE->domain);	835	int dlen = strlen (THISNODE->domain);
669		836
670	if (qclass == RR_CLASS_IN	837	if (qclass == RR_CLASS_IN
671	&& (qtype == RR_TYPE_ANY \|\| qtype == RR_TYPE_TXT)
672	&& qlen > dlen + 1 + HDRSIZE	838	&& qlen > dlen + 1
673	&& !memcmp (qname + qlen - dlen - 1, THISNODE->domain, dlen))	839	&& !memcmp (qname + qlen - (dlen + 1), THISNODE->domain, dlen))
674	{	840	{
675	// correct class, domain: parse	841	// now generate reply
676	int client, seqno;	842	pkt.ancount = htons (1); // one answer RR
677	decode_header (qname, client, seqno);	843	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_OK);
678		844
679	u8 data[MAXSIZE];	845	if ((qtype == RR_TYPE_ANY
680	int datalen = cdc62.decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE));	846	\|\| qtype == RR_TYPE_TXT
681		847	\|\| qtype == RR_TYPE_NULL)
682	if (0 < client && client <= conns.size ())	848	&& qlen > dlen + 1 + HDRSIZE)
683	{	849	{
		850	// correct class, domain: parse
		851	int client, seqno;
		852	decode_header (qname, client, seqno);
		853
		854	u8 data[MAXSIZE];
		855	int datalen = cdc62.decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE));
		856
		857	if (0 < client && client <= conns.size ())
		858	{
684	connection *c = conns [client - 1];	859	connection *c = conns [client - 1];
685
686	if (!c->dns)
687	c->dns = new dns_connection (c);
688
689	dns_connection *dns = c->dns;	860	dns_connection *dns = c->dns;
		861	dns_rcv *rcv;
690		862
		863	if (dns)
		864	{
691	for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); )	865	for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); )
692	if (SEQNO_EQ ((*i)->seqno, seqno))	866	if (SEQNO_EQ ((*i)->seqno, seqno))
		867	{
		868	// already seen that request: simply reply with the cached reply
		869	dns_rcv r = i;
		870
		871	slog (L_DEBUG, "DNS: duplicate packet received ID %d, SEQ %d", htons (r->pkt->id), seqno);
		872
		873	// refresh header & id, as the retry count could have changed
		874	memcpy (r->pkt->at (6 * 2 + 1), pkt.at (6 * 2 + 1), HDRSIZE);
		875	r->pkt->id = pkt.id;
		876
		877	memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len);
		878
		879	goto duplicate_request;
		880	}
		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	//printf ("%d - %d & %x (=%d) < %d\n", seqno, dns->repseq, SEQNO_MASK, (seqno - dns->repseq) & SEQNO_MASK, MAX_WINDOW);//D
		909	if (((seqno - dns->repseq) & SEQNO_MASK) <= MAX_WINDOW)
		910	{
		911	dns->repseq = seqno;
		912
		913	while (dlen > 1 && !dns->snddq.empty ())
		914	{
		915	int txtlen = dlen <= 255 ? dlen - 1 : 255;
		916
		917	if (txtlen > dns->snddq.size ())
		918	txtlen = dns->snddq.size ();
		919
		920	pkt[offs++] = txtlen;
		921	memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
		922	offs += txtlen;
		923	dns->snddq.remove (txtlen);
		924
		925	dlen -= txtlen + 1;
		926	}
		927	}
		928
		929	// avoid completely empty TXT rdata
		930	if (offs == rdlen_offs)
		931	pkt[offs++] = 0;
		932
		933	slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
		934	}
		935	else
		936	{
		937	// send RST
		938	pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
		939	pkt [offs++] = CMD_IP_RST;
		940	}
		941
		942	int rdlen = offs - rdlen_offs;
		943
		944	pkt [rdlen_offs - 2] = rdlen >> 8;
		945	pkt [rdlen_offs - 1] = rdlen;
		946
		947	if (dns)
		948	{
		949	// now update dns_rcv copy
		950	rcv->pkt->len = offs;
		951	memcpy (rcv->pkt->at (0), pkt.at (0), offs);
		952	}
702	}	953	}
703		954
704	// new packet, queue	955	duplicate_request: ;
705	dns_rcv *rcv = new dns_rcv (seqno, data, datalen);	956	}
706	dns->receive_rep (rcv);	957	else
707
708	// now generate reply
709	pkt->ancount = htons (1); // one answer RR
710	pkt->flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_OK);	958	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);
		959	}
		960	else if (qtype == RR_TYPE_A
		961	&& qlen > dlen + 1 + cdc26.encode_len (sizeof (dns_cfg)))
		962	{
		963	dns_cfg cfg;
		964	cdc26.decode ((u8 *)&cfg, qname, cdc26.encode_len (sizeof (dns_cfg)));
		965	int client = ntohs (cfg.client);
711		966
712	(*pkt) [offs++] = 0xc0;
713	(pkt) [offs++] = 6 2; // same as in query section	967	pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section
714		968
715	(pkt) [offs++] = RR_TYPE_TXT >> 8; (pkt) [offs++] = RR_TYPE_TXT;	969	pkt [offs++] = RR_TYPE_A >> 8; pkt [offs++] = RR_TYPE_A; // type
716	(pkt) [offs++] = RR_CLASS_IN >> 8; (pkt) [offs++] = RR_CLASS_IN;	970	pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
717
718	(pkt) [offs++] = 0; (pkt) [offs++] = 0;	971	pkt [offs++] = 0; pkt [offs++] = 0;
719	(pkt) [offs++] = 0; (pkt) [offs++] = 0; // TTL	972	pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL
		973	pkt [offs++] = 0; pkt [offs++] = 4; // rdlength
720		974
721	int dlen = MAX_PKT_SIZE - offs - 2;	975	slog (L_INFO, _("DNS: client %d connects"), client);
722		976
723	// bind doesn't compress well, so reduce further by one label length	977	pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
724	dlen -= qlen;	978	pkt [offs++] = CMD_IP_REJ;
725		979
726	int rdlen_offs = offs += 2;	980	if (0 < client && client <= conns.size ())
727
728	while (dlen > 1 && !dns->snddq.empty ())
729	{	981	{
730	int txtlen = dlen <= 255 ? dlen - 1 : 255;	982	connection *c = conns [client - 1];
731		983
732	if (txtlen > dns->snddq.size ())	984	if (cfg.valid ())
733	txtlen = dns->snddq.size ();	985	{
		986	pkt [offs - 1] = CMD_IP_SYN;
734		987
735	(*pkt)[offs++] = txtlen;	988	delete c->dns;
736	memcpy (pkt->at (offs), dns->snddq.begin (), txtlen);	989	c->dns = new dns_connection (c);
737	offs += txtlen;	990	c->dns->cfg = cfg;
738	dns->snddq.remove (txtlen);	991	}
739
740	dlen -= txtlen + 1;
741	}	992	}
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	}	993	}
758	else
759	pkt->flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);
760	}	994	}
761		995
762	pkt->len = offs;	996	pkt.len = offs;
763	}	997	}
764
765	return pkt;
766	}	998	}
767		999
768	void	1000	void
769	vpn::dnsv4_client (dns_packet *pkt)	1001	vpn::dnsv4_client (dns_packet &pkt)
770	{	1002	{
771	u16 flags = ntohs (pkt->flags);	1003	u16 flags = ntohs (pkt.flags);
772	int offs = 6 * 2; // skip header	1004	int offs = 6 * 2; // skip header
773		1005
774	pkt->qdcount = ntohs (pkt->qdcount);	1006	pkt.qdcount = ntohs (pkt.qdcount);
775	pkt->ancount = ntohs (pkt->ancount);	1007	pkt.ancount = ntohs (pkt.ancount);
776		1008
777	// go through our request list and find the corresponding request	1009	// go through our request list and find the corresponding request
778	for (vector<dns_req *>::iterator i = dns_sndpq.begin ();	1010	for (vector<dns_snd *>::iterator i = dns_sndpq.begin ();
779	i != dns_sndpq.end ();	1011	i != dns_sndpq.end ();
780	++i)	1012	++i)
781	if ((*i)->pkt->id == pkt->id)	1013	if ((*i)->pkt->id == pkt.id)
782	{	1014	{
783	dns_connection dns = (i)->dns;	1015	dns_connection dns = (i)->dns;
		1016	connection *c = dns->c;
784	int seqno = (*i)->seqno;	1017	int seqno = (*i)->seqno;
785	u8 data[MAXSIZE], *datap = data;	1018	u8 data[MAXSIZE], *datap = data;
786		1019
		1020	if ((*i)->retry)
		1021	{
		1022	dns->send_interval *= 1.01;
		1023	if (dns->send_interval > MAX_SEND_INTERVAL)
		1024	dns->send_interval = MAX_SEND_INTERVAL;
		1025	}
		1026	else
		1027	{
		1028	#if 0
		1029	dns->send_interval *= 0.999;
		1030	#endif
		1031	// the latency surely puts an upper bound on
		1032	// the minimum send interval
		1033	double latency = NOW - (*i)->sent;
		1034
		1035	if (latency < dns->min_latency)
		1036	dns->min_latency = latency;
		1037
		1038	if (dns->send_interval > dns->min_latency * LATENCY_FACTOR)
		1039	dns->send_interval = dns->min_latency * LATENCY_FACTOR;
		1040
		1041	if (dns->send_interval < MIN_SEND_INTERVAL)
		1042	dns->send_interval = MIN_SEND_INTERVAL;
		1043	}
		1044
787	delete *i;	1045	delete *i;
788	dns_sndpq.erase (i);	1046	dns_sndpq.erase (i);
789		1047
790	if (flags & FLAG_RESPONSE && !(flags & (FLAG_OP_MASK \| FLAG_TC)))	1048	if (flags & FLAG_RESPONSE && !(flags & FLAG_OP_MASK))
791	{	1049	{
792	char qname[MAXSIZE];	1050	char qname[MAXSIZE];
793		1051
794	while (pkt->qdcount-- && offs < MAXSIZE - 4)	1052	while (pkt.qdcount-- && offs < MAXSIZE - 4)
795	{	1053	{
796	int qlen = pkt->decode_label ((char *)qname, MAXSIZE - offs, offs);	1054	int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
797	offs += 4; // skip qtype, qclass	1055	offs += 4; // skip qtype, qclass
798	}	1056	}
799		1057
800	while (pkt->ancount-- && offs < MAXSIZE - 10 && datap)	1058	while (pkt.ancount-- && offs < MAXSIZE - 10 && datap)
801	{	1059	{
802	int qlen = pkt->decode_label ((char *)qname, MAXSIZE - offs, offs);	1060	int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
803		1061
804	u16 qtype = (pkt) [offs++] << 8; qtype \|= (pkt) [offs++];	1062	u16 qtype = pkt [offs++] << 8; qtype \|= pkt [offs++];
805	u16 qclass = (pkt) [offs++] << 8; qclass \|= (pkt) [offs++];	1063	u16 qclass = pkt [offs++] << 8; qclass \|= pkt [offs++];
806	u32 ttl = (*pkt) [offs++] << 24;	1064	u32 ttl = pkt [offs++] << 24;
807	ttl \|= (*pkt) [offs++] << 16;	1065	ttl \|= pkt [offs++] << 16;
808	ttl \|= (*pkt) [offs++] << 8;	1066	ttl \|= pkt [offs++] << 8;
809	ttl \|= (*pkt) [offs++];	1067	ttl \|= pkt [offs++];
810
811	u16 rdlen = (pkt) [offs++] << 8; rdlen \|= (pkt) [offs++];	1068	u16 rdlen = pkt [offs++] << 8; rdlen \|= pkt [offs++];
812		1069
813	if (rdlen <= MAXSIZE - offs)	1070	if (qtype == RR_TYPE_NULL \|\| qtype == RR_TYPE_TXT)
814	{	1071	{
815	// decode bytes, finally	1072	if (rdlen <= MAXSIZE - offs)
816
817	while (rdlen)
818	{	1073	{
		1074	// decode bytes, finally
		1075
		1076	while (rdlen)
		1077	{
819	int txtlen = (*pkt) [offs++];	1078	int txtlen = pkt [offs++];
820		1079
821	assert (txtlen + offs < MAXSIZE - 1);	1080	assert (txtlen + offs < MAXSIZE - 1);
822		1081
823	memcpy (datap, pkt->at (offs), txtlen);	1082	memcpy (datap, pkt.at (offs), txtlen);
824	datap += txtlen; offs += txtlen;	1083	datap += txtlen; offs += txtlen;
825		1084
826	rdlen -= txtlen + 1;	1085	rdlen -= txtlen + 1;
		1086	}
827	}	1087	}
828	}	1088	}
		1089	else if (qtype == RR_TYPE_A)
		1090	{
		1091	u8 ip [4];
		1092
		1093	ip [0] = pkt [offs++];
		1094	ip [1] = pkt [offs++];
		1095	ip [2] = pkt [offs++];
		1096	ip [3] = pkt [offs++];
		1097
		1098	if (ip [0] == CMD_IP_1
		1099	&& ip [1] == CMD_IP_2
		1100	&& ip [2] == CMD_IP_3)
		1101	{
		1102	slog (L_TRACE, _("DNS: got tunnel meta command %02x"), ip [3]);
		1103
		1104	if (ip [3] == CMD_IP_RST)
		1105	{
		1106	slog (L_DEBUG, _("DNS: got tunnel RST request"));
		1107
		1108	delete dns; c->dns = 0;
		1109
		1110	return;
		1111	}
		1112	else if (ip [3] == CMD_IP_SYN)
		1113	{
		1114	slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us."));
		1115	dns->established = true;
		1116	}
		1117	else if (ip [3] == CMD_IP_REJ)
		1118	{
		1119	slog (L_DEBUG, _("DNS: got tunnel REJ reply, server does not like us, aborting."));
		1120	abort ();
		1121	}
		1122	else
		1123	slog (L_INFO, _("DNS: got unknown meta command %02x"), ip [3]);
		1124	}
		1125	else
		1126	slog (L_INFO, _("DNS: got spurious a record %d.%d.%d.%d"),
		1127	ip [0], ip [1], ip [2], ip [3]);
		1128
		1129	return;
		1130	}
829		1131
830	int client, rseqno;	1132	int client, rseqno;
831	decode_header (qname, client, rseqno);	1133	decode_header (qname, client, rseqno);
832		1134
833	if (client != THISNODE->id)	1135	if (client != THISNODE->id)
834	{	1136	{
835	slog (L_INFO, _("got dns tunnel response with wrong clientid, ignoring"));	1137	slog (L_INFO, _("DNS: got dns tunnel response with wrong clientid, ignoring"));
836	datap = 0;	1138	datap = 0;
837	}	1139	}
838	else if (rseqno != seqno)	1140	else if (rseqno != seqno)
839	{	1141	{
840	slog (L_DEBUG, _("got dns tunnel response with wrong seqno, badly caching nameserver?"));	1142	slog (L_DEBUG, _("DNS: got dns tunnel response with wrong seqno, badly caching nameserver?"));
841	datap = 0;	1143	datap = 0;
842	}	1144	}
843	}	1145	}
844	}	1146	}
845		1147
…		…
847	if (datap)	1149	if (datap)
848	dns->receive_rep (new dns_rcv (seqno, data, datap - data));	1150	dns->receive_rep (new dns_rcv (seqno, data, datap - data));
849		1151
850	break;	1152	break;
851	}	1153	}
852
853	delete pkt;
854	}	1154	}
855		1155
856	void	1156	void
857	vpn::dnsv4_ev (io_watcher &w, short revents)	1157	vpn::dnsv4_ev (io_watcher &w, short revents)
858	{	1158	{
…		…
860	{	1160	{
861	dns_packet *pkt = new dns_packet;	1161	dns_packet *pkt = new dns_packet;
862	struct sockaddr_in sa;	1162	struct sockaddr_in sa;
863	socklen_t sa_len = sizeof (sa);	1163	socklen_t sa_len = sizeof (sa);
864		1164
865	pkt->len = recvfrom (w.fd, &((pkt)[0]), MAXSIZE, 0, (sockaddr )&sa, &sa_len);	1165	pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len);
866		1166
867	if (pkt->len > 0)	1167	if (pkt->len > 0)
868	{	1168	{
869	if (pkt->flags & htons (FLAG_TC))	1169	if (ntohs (pkt->flags) & FLAG_RESPONSE)
		1170	dnsv4_client (*pkt);
		1171	else
870	{	1172	{
871	slog (L_WARN, _("DNS request/response truncated, check protocol settings."));	1173	dnsv4_server (*pkt);
872	//TODO connection reset	1174	sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len);
873	}	1175	}
874		1176
875	if (THISNODE->dns_port)	1177	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	}	1178	}
883	}	1179	}
884	}	1180	}
885		1181
886	bool	1182	bool
887	connection::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)	1183	vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
888	{	1184	{
		1185	int client = ntohs (si.port);
		1186
		1187	assert (0 < client && client <= conns.size ());
		1188
		1189	connection *c = conns [client - 1];
		1190
889	if (!dns)	1191	if (!c->dns)
890	dns = new dns_connection (this);	1192	c->dns = new dns_connection (c);
891		1193
892	if (!dns->snddq.put (pkt))	1194	if (c->dns->snddq.put (pkt))
893	return false;
894
895	// start timer if neccessary
896	if (!THISNODE->dns_port && !dns->tw.active)
897	dns->tw.trigger ();	1195	c->dns->tw.trigger ();
898		1196
		1197	// always return true even if the buffer overflows
899	return true;	1198	return true;
900	}	1199	}
		1200
		1201	void
		1202	connection::dnsv4_reset_connection ()
		1203	{
		1204	//delete dns; dns = 0; //TODO
		1205	}
		1206
		1207	#define NEXT(w) do { if (next > (w)) next = w; } while (0)
901		1208
902	void	1209	void
903	dns_connection::time_cb (time_watcher &w)	1210	dns_connection::time_cb (time_watcher &w)
904	{	1211	{
		1212	// servers have to be polled
		1213	if (THISNODE->dns_port)
		1214	return;
		1215
905	// check for timeouts and (re)transmit	1216	// check for timeouts and (re)transmit
906	tstamp next = NOW + 60;	1217	tstamp next = NOW + poll_interval;
907	dns_req *send = 0;	1218	dns_snd *send = 0;
908		1219
909	for (vector<dns_req *>::iterator i = vpn->dns_sndpq.begin ();	1220	for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin ();
910	i != vpn->dns_sndpq.end ();	1221	i != vpn->dns_sndpq.end ();
911	++i)	1222	++i)
912	{	1223	{
913	dns_req r = i;	1224	dns_snd r = i;
914		1225
915	if (r->next <= NOW)	1226	if (r->timeout <= NOW)
916	{	1227	{
917	if (!send)	1228	if (!send)
918	{	1229	{
919	send = r;	1230	send = r;
920		1231
921	if (r->retry)//D
922	printf ("req %d:%d, retry %d\n", r->seqno, r->pkt->id, r->retry);
923	r->retry++;	1232	r->retry++;
924	r->next = NOW + r->retry;	1233	r->timeout = NOW + (r->retry * min_latency * TIMEOUT_FACTOR);
		1234
		1235	// the following code changes the query section a bit, forcing
		1236	// the forwarder to generate a new request
		1237	if (r->stdhdr)
		1238	{
		1239	//printf ("reencoded header for ID %d retry %d:%d:%d (%p)\n", htons (r->pkt->id), THISNODE->id, r->seqno, r->retry);
		1240	//encode_header ((char )r->pkt->at (6 2 + 1), THISNODE->id, r->seqno, r->retry);
		1241	}
925	}	1242	}
926	}	1243	}
927		1244	else
928	if (r->next < next)	1245	NEXT (r->timeout);
929	next = r->next;
930	}	1246	}
931		1247
932	if (!send	1248	if (!send)
		1249	{
		1250	// generate a new packet, if wise
		1251
		1252	if (!established)
		1253	{
		1254	if (vpn->dns_sndpq.empty ())
		1255	{
		1256	send = new dns_snd (this);
		1257
		1258	cfg.reset (THISNODE->id);
		1259	send->gen_syn_req ();
		1260	}
		1261	}
933	&& vpn->dns_sndpq.size () < MAX_OUTSTANDING)	1262	else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING
934	{	1263	&& !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
		1264	{
		1265	if (last_sent + send_interval <= NOW)
		1266	{
		1267	//printf ("sending data request etc.\n"); //D
		1268	if (!snddq.empty () \|\| last_received + 1. > NOW)
		1269	{
		1270	poll_interval = send_interval;
		1271	NEXT (NOW + send_interval);
		1272	}
		1273
935	send = new dns_req (this);	1274	send = new dns_snd (this);
936	send->gen_stream_req (sndseq, snddq);	1275	send->gen_stream_req (sndseq, snddq);
		1276	send->timeout = NOW + min_latency * TIMEOUT_FACTOR;
		1277
		1278	sndseq = (sndseq + 1) & SEQNO_MASK;
		1279	}
		1280	else
		1281	NEXT (last_sent + send_interval);
		1282	}
		1283
		1284	if (send)
937	vpn->dns_sndpq.push_back (send);	1285	vpn->dns_sndpq.push_back (send);
938
939	sndseq = (sndseq + 1) & SEQNO_MASK;
940	}	1286	}
941
942	tstamp min_next = NOW + (1. / (tstamp)MAX_RATE);
943		1287
944	if (send)	1288	if (send)
945	{	1289	{
946	dns_packet *pkt = send->pkt;	1290	last_sent = NOW;
947		1291	if (rand () & 15 != 0)//D
948	next = min_next;	1292	sendto (vpn->dnsv4_fd,
949		1293	send->pkt->at (0), send->pkt->len, 0,
950	sendto (vpn->dnsv4_fd, &((*pkt)[0]), pkt->len, 0,
951	vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());	1294	vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
952	}	1295	}
953	else if (next < min_next)	1296
954	next = min_next;	1297	slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)",
		1298	poll_interval, send_interval, next - NOW,
		1299	vpn->dns_sndpq.size (), snddq.size (),
		1300	rcvpq.size ());
		1301
		1302	// TODO: no idea when this happens, but when next < NOW, we have a problem
		1303	if (next < NOW + 0.001)
		1304	next = NOW + 0.1;
955		1305
956	w.start (next);	1306	w.start (next);
957	}	1307	}
958		1308
959	#endif	1309	#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 1.31 by pcg, Tue Mar 15 11:43:38 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 1.31 by pcg, Tue Mar 15 11:43:38 2005 UTC