[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 1.30 by pcg, Mon Mar 14 17:40:01 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 INITIAL_TIMEOUT 0.1 // retry timeouts
		53	#define INITIAL_SYN_TIMEOUT 10. // retry timeout for initial syn
		54
		55	#define MIN_SEND_INTERVAL 0.001 // wait at least this time between sending requests
		56	#define MAX_SEND_INTERVAL 2. // optimistic?
		57
		58	#define LATENCY_FACTOR 0.5 // RTT * LATENCY_FACTOR == sending rate
51	#define MAX_OUTSTANDING 400 // max. outstanding requests	59	#define MAX_OUTSTANDING 2 // 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 100 // 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 240 // 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	#define SEQNO_MASK 0xffff	67	#define SEQNO_MASK 0x3fff
61	#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )	68	#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )
62		69
63	#define MAX_LBL_SIZE 63	70	#define MAX_LBL_SIZE 63
64	#define MAX_PKT_SIZE 512	71	#define MAX_PKT_SIZE 512
65		72
		73	#define RR_TYPE_A 1
		74	#define RR_TYPE_NULL 10
66	#define RR_TYPE_TXT 16	75	#define RR_TYPE_TXT 16
67	#define RR_TYPE_ANY 255	76	#define RR_TYPE_ANY 255
		77
68	#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
69		86
70	// works for cmaps up to 255 (not 256!)	87	// works for cmaps up to 255 (not 256!)
71	struct charmap	88	struct charmap
72	{	89	{
73	enum { INVALID = (u8)255 };	90	enum { INVALID = (u8)255 };
…		…
153	return dec_len [len];	170	return dec_len [len];
154	}	171	}
155		172
156	unsigned int basecoder::encode (char dst, u8 src, unsigned int len)	173	unsigned int basecoder::encode (char dst, u8 src, unsigned int len)
157	{	174	{
158	if (!len)	175	if (!len \|\| len > MAX_DEC_LEN)
159	return 0;	176	return 0;
160		177
161	int elen = encode_len (len);	178	int elen = encode_len (len);
162		179
163	mp_limb_t m [MAX_LIMBS];	180	mp_limb_t m [MAX_LIMBS];
…		…
182	return elen;	199	return elen;
183	}	200	}
184		201
185	unsigned int basecoder::decode (u8 dst, char src, unsigned int len)	202	unsigned int basecoder::decode (u8 dst, char src, unsigned int len)
186	{	203	{
187	if (!len)	204	if (!len \|\| len > MAX_ENC_LEN)
188	return 0;	205	return 0;
189		206
190	u8 src_ [MAX_ENC_LEN];	207	u8 src_ [MAX_ENC_LEN];
191	unsigned int elen = 0;	208	unsigned int elen = 0;
192		209
…		…
239	}	256	}
240	abort ();	257	abort ();
241	}	258	}
242	#endif	259	#endif
243		260
244	// the following sequence has been crafted to	261	//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");	262	//static basecoder cdc63 ("_dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI");
250	static basecoder cdc62 ("dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI");	263	static basecoder cdc62 ("dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI");
251	//static basecoder cdc36 ("dphzr06qmjkb34tsvl81xaef92wgyo57ucni"); // unused as of yet	264	//static basecoder cdc36 ("dphzr06qmjkb34tsvl81xaef92wgyo57ucni"); // unused as of yet
252	static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO");	265	static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO");
253		266
254	/////////////////////////////////////////////////////////////////////////////	267	/////////////////////////////////////////////////////////////////////////////
255		268
256	#define HDRSIZE 6	269	#define HDRSIZE 6
257		270
258	inline void encode_header (char *data, int clientid, int seqno)	271	inline void encode_header (char *data, int clientid, int seqno, int retry = 0)
259	{	272	{
260	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	};
261		280
262	assert (clientid < 256);	281	assert (clientid < 256);
263		282
264	cdc26.encode (data, hdr, 3);	283	cdc26.encode (data, hdr, 3);
265	}	284	}
…		…
269	u8 hdr[3];	288	u8 hdr[3];
270		289
271	cdc26.decode (hdr, data, HDRSIZE);	290	cdc26.decode (hdr, data, HDRSIZE);
272		291
273	clientid = hdr[0];	292	clientid = hdr[0];
274	seqno = (hdr[1] << 8) \| hdr[2];	293	seqno = ((hdr[1] << 8) \| hdr[2]) & SEQNO_MASK;
275	}	294	}
276		295
277	/////////////////////////////////////////////////////////////////////////////	296	/////////////////////////////////////////////////////////////////////////////
278		297
279	struct byte_stream	298	struct byte_stream
…		…
308	}	327	}
309		328
310	void byte_stream::remove (int count)	329	void byte_stream::remove (int count)
311	{	330	{
312	if (count > fill)	331	if (count > fill)
313	abort ();	332	assert (count <= fill);
314		333
315	memmove (data, data + count, fill -= count);	334	memmove (data, data + count, fill -= count);
316	}	335	}
317		336
318	bool byte_stream::put (u8 *data, unsigned int datalen)	337	bool byte_stream::put (u8 *data, unsigned int datalen)
…		…
331	return false;	350	return false;
332		351
333	data [fill++] = pkt->len >> 8;	352	data [fill++] = pkt->len >> 8;
334	data [fill++] = pkt->len;	353	data [fill++] = pkt->len;
335		354
336	memcpy (data + fill, &((*pkt)[0]), pkt->len); fill += pkt->len;	355	memcpy (data + fill, pkt->at (0), pkt->len); fill += pkt->len;
337		356
338	return true;	357	return true;
339	}	358	}
340		359
341	vpn_packet *byte_stream::get ()	360	vpn_packet *byte_stream::get ()
342	{	361	{
		362	unsigned int len;
		363
		364	for (;;)
		365	{
343	int len = (data [0] << 8) \| data [1];	366	len = (data [0] << 8) \| data [1];
344		367
345	if (len > MAXSIZE && fill >= 2)	368	if (len <= MAXSIZE \|\| fill < 2)
346	abort (); // TODO handle this gracefully, connection reset	369	break;
347		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
348	if (fill < len + 2)	376	if (fill < len + 2)
349	return 0;	377	return 0;
350		378
351	vpn_packet *pkt = new vpn_packet;	379	vpn_packet *pkt = new vpn_packet;
352		380
353	pkt->len = len;	381	pkt->len = len;
354	memcpy (&((*pkt)[0]), data + 2, len);	382	memcpy (pkt->at (0), data + 2, len);
355	remove (len + 2);	383	remove (len + 2);
356		384
357	return pkt;	385	return pkt;
358	}	386	}
359		387
…		…
376	#define FLAG_RCODE_REFUSED ( 5 << 0)	404	#define FLAG_RCODE_REFUSED ( 5 << 0)
377		405
378	#define DEFAULT_CLIENT_FLAGS (FLAG_QUERY \| FLAG_OP_QUERY \| FLAG_RD)	406	#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)	407	#define DEFAULT_SERVER_FLAGS (FLAG_RESPONSE \| FLAG_OP_QUERY \| FLAG_AA \| FLAG_RD \| FLAG_RA)
380		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 delay; // time in 0.01s units that the server may delay replying packets
		429	u8 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	delay = 0;
		458
		459	r3 = r4 = 0;
		460	r4 = r5 = r6 = r7 = 0;
		461	}
		462
		463	bool dns_cfg::valid ()
		464	{
		465	return id1 == 'G'
		466	&& id2 == 'V'
		467	&& id3 == 'P'
		468	&& id4 == 'E'
		469	&& seq_cdc == 26
		470	&& req_cdc == 62
		471	&& rep_cdc == 0
		472	&& version == 1;
		473	}
		474
381	struct dns_packet : net_packet	475	struct dns_packet : net_packet
382	{	476	{
383	u16 id;	477	u16 id;
384	u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4	478	u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4
385	u16 qdcount, ancount, nscount, arcount;	479	u16 qdcount, ancount, nscount, arcount;
386		480
387	u8 data[MAXSIZE - 6 * 2];	481	u8 data [MAXSIZE - 6 * 2];
388		482
389	int decode_label (char *data, int size, int &offs);	483	int decode_label (char *data, int size, int &offs);
390	};	484	};
391		485
392	int dns_packet::decode_label (char *data, int size, int &offs)	486	int dns_packet::decode_label (char *data, int size, int &offs)
…		…
423	return data - orig;	517	return data - orig;
424	}	518	}
425		519
426	/////////////////////////////////////////////////////////////////////////////	520	/////////////////////////////////////////////////////////////////////////////
427		521
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	522	static u16 dns_id = 0; // TODO: should be per-vpn
441		523
442	static u16 next_id ()	524	static u16 next_id ()
443	{	525	{
		526	if (!dns_id)
		527	dns_id = time (0);
		528
444	// the simplest lsfr with periodicity 65535 i could find	529	// the simplest lsfr with periodicity 65535 i could find
445	dns_id = (dns_id << 1)	530	dns_id = (dns_id << 1)
446	\| (((dns_id >> 1)	531	\| (((dns_id >> 1)
447	^ (dns_id >> 2)	532	^ (dns_id >> 2)
448	^ (dns_id >> 4)	533	^ (dns_id >> 4)
449	^ (dns_id >> 15)) & 1);	534	^ (dns_id >> 15)) & 1);
450		535
451	return dns_id;	536	return dns_id;
452	}	537	}
453		538
		539	struct dns_rcv;
		540	struct dns_snd;
		541
		542	struct dns_connection
		543	{
		544	connection *c;
		545	struct vpn *vpn;
		546
		547	dns_cfg cfg;
		548
		549	bool established;
		550
		551	tstamp last_received;
		552	tstamp last_sent;
		553	double min_latency;
		554	double poll_interval, send_interval;
		555
		556	vector<dns_rcv *> rcvpq;
		557
		558	byte_stream rcvdq; int rcvseq;
		559	byte_stream snddq; int sndseq;
		560
		561	void time_cb (time_watcher &w); time_watcher tw;
		562	void receive_rep (dns_rcv *r);
		563
		564	dns_connection (connection *c);
		565	~dns_connection ();
		566	};
		567
		568	struct dns_snd
		569	{
		570	dns_packet *pkt;
		571	tstamp timeout, sent;
		572	int retry;
		573	struct dns_connection *dns;
		574	int seqno;
		575	bool stdhdr;
		576
		577	void gen_stream_req (int seqno, byte_stream &stream);
		578	void gen_syn_req ();
		579
		580	dns_snd (dns_connection *dns);
		581	~dns_snd ();
		582	};
		583
454	dns_req::dns_req (dns_connection *dns)	584	dns_snd::dns_snd (dns_connection *dns)
455	: dns (dns)	585	: dns (dns)
456	{	586	{
457	next = 0;	587	timeout = 0;
458	retry = 0;	588	retry = 0;
		589	seqno = 0;
		590	sent = NOW;
		591	stdhdr = false;
459		592
460	pkt = new dns_packet;	593	pkt = new dns_packet;
461		594
462	pkt->id = next_id ();	595	pkt->id = next_id ();
463	}	596	}
464		597
		598	dns_snd::~dns_snd ()
		599	{
		600	delete pkt;
		601	}
		602
		603	static void append_domain (dns_packet &pkt, int &offs, const char *domain)
		604	{
		605	// add tunnel domain
		606	for (;;)
		607	{
		608	const char *end = strchr (domain, '.');
		609
		610	if (!end)
		611	end = domain + strlen (domain);
		612
		613	int len = end - domain;
		614
		615	pkt [offs++] = len;
		616	memcpy (pkt.at (offs), domain, len);
		617	offs += len;
		618
		619	if (!*end)
		620	break;
		621
		622	domain = end + 1;
		623	}
		624	}
		625
465	void dns_req::gen_stream_req (int seqno, byte_stream &stream)	626	void dns_snd::gen_stream_req (int seqno, byte_stream &stream)
466	{	627	{
		628	stdhdr = true;
467	this->seqno = seqno;	629	this->seqno = seqno;
		630
		631	timeout = NOW + INITIAL_TIMEOUT;
468		632
469	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);	633	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
470	pkt->qdcount = htons (1);	634	pkt->qdcount = htons (1);
471		635
472	int offs = 6*2;	636	int offs = 6*2;
473	int dlen = MAX_DOMAIN_SIZE - (strlen (THISNODE->domain) + 2);	637	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,	638	// 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	639	// so we need to have space for 2*MAX_DOMAIN_SIZE + header + extra
476		640
477	char enc[256], *encp = enc;	641	char enc[256], *encp = enc;
478	encode_header (enc, THISNODE->id, seqno);	642	encode_header (enc, THISNODE->id, seqno);
…		…
496	encp += lbllen;	660	encp += lbllen;
497		661
498	enclen -= lbllen;	662	enclen -= lbllen;
499	}	663	}
500		664
501	const char *suffix = THISNODE->domain;	665	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		666
523	(*pkt)[offs++] = 0;	667	(*pkt)[offs++] = 0;
524	(pkt)[offs++] = RR_TYPE_ANY >> 8; (pkt)[offs++] = RR_TYPE_ANY;	668	(pkt)[offs++] = RR_TYPE_ANY >> 8; (pkt)[offs++] = RR_TYPE_ANY;
		669	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;
		670
		671	pkt->len = offs;
		672	}
		673
		674	void dns_snd::gen_syn_req ()
		675	{
		676	timeout = NOW + INITIAL_SYN_TIMEOUT;
		677
		678	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
		679	pkt->qdcount = htons (1);
		680
		681	int offs = 6 * 2;
		682
		683	int elen = cdc26.encode ((char )pkt->at (offs + 1), (u8 )&dns->cfg, sizeof (dns_cfg));
		684
		685	assert (elen <= MAX_LBL_SIZE);
		686
		687	(*pkt)[offs] = elen;
		688	offs += elen + 1;
		689	append_domain (*pkt, offs, dns->c->conf->domain);
		690
		691	(*pkt)[offs++] = 0;
		692	(pkt)[offs++] = RR_TYPE_A >> 8; (pkt)[offs++] = RR_TYPE_A;
525	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;	693	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;
526		694
527	pkt->len = offs;	695	pkt->len = offs;
528	}	696	}
529		697
…		…
549	delete pkt;	717	delete pkt;
550	}	718	}
551		719
552	/////////////////////////////////////////////////////////////////////////////	720	/////////////////////////////////////////////////////////////////////////////
553		721
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)	722	dns_connection::dns_connection (connection *c)
575	: c (c)	723	: c (c)
576	, rcvdq (MAX_BACKLOG * 2)	724	, rcvdq (MAX_BACKLOG * 2)
577	, snddq (MAX_BACKLOG * 2)	725	, snddq (MAX_BACKLOG * 2)
578	, tw (this, &dns_connection::time_cb)	726	, tw (this, &dns_connection::time_cb)
579	{	727	{
580	vpn = c->vpn;	728	vpn = c->vpn;
581		729
		730	established = false;
		731
582	rcvseq = sndseq = 0;	732	rcvseq = sndseq = 0;
		733
		734	last_sent = last_received = 0;
		735	poll_interval = 0.5; // starting here
		736	send_interval = 0.5; // starting rate
		737	min_latency = INITIAL_TIMEOUT;
583	}	738	}
584		739
585	dns_connection::~dns_connection ()	740	dns_connection::~dns_connection ()
586	{	741	{
587	for (vector<dns_rcv *>::iterator i = rcvpq.begin ();	742	for (vector<dns_rcv *>::iterator i = rcvpq.begin ();
588	i != rcvpq.end ();	743	i != rcvpq.end ();
589	++i)	744	++i)
590	delete *i;	745	delete *i;
591	}	746	}
592		747
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)	748	void dns_connection::receive_rep (dns_rcv *r)
603	{	749	{
		750	if (r->datalen)
		751	{
		752	last_received = NOW;
		753	tw.trigger ();
		754
		755	poll_interval = send_interval;
		756	}
		757	else
		758	{
		759	poll_interval *= 1.5;
		760
		761	if (poll_interval > MAX_POLL_INTERVAL)
		762	poll_interval = MAX_POLL_INTERVAL;
		763	}
		764
604	rcvpq.push_back (r);	765	rcvpq.push_back (r);
605		766
606	redo:	767	redo:
607		768
608	// find next packet	769	// find next packet
…		…
622	}	783	}
623		784
624	rcvseq = (rcvseq + 1) & SEQNO_MASK;	785	rcvseq = (rcvseq + 1) & SEQNO_MASK;
625		786
626	if (!rcvdq.put (r->data, r->datalen))	787	if (!rcvdq.put (r->data, r->datalen))
		788	{
		789	slog (L_ERR, "DNS: !rcvdq.put (r->data, r->datalen)");
627	abort (); // MUST never overflow, can be caused by data corruption, TODO	790	abort (); // MUST never overflow, can be caused by data corruption, TODO
		791	}
628		792
629	while (vpn_packet *pkt = rcvdq.get ())	793	while (vpn_packet *pkt = rcvdq.get ())
630	{	794	{
631	sockinfo si;	795	sockinfo si;
632	si.host = 0; si.port = 0; si.prot = PROT_DNSv4;	796	si.host = 0x01010101; si.port = htons (c->conf->id); si.prot = PROT_DNSv4;
633		797
634	vpn->recv_vpn_packet (pkt, si);	798	vpn->recv_vpn_packet (pkt, si);
		799
		800	delete pkt;
635	}	801	}
636		802
637	// check for further packets	803	// check for further packets
638	goto redo;	804	goto redo;
639	}	805	}
640	}	806	}
641		807
642	dns_packet *	808	void
643	vpn::dnsv4_server (dns_packet *pkt)	809	vpn::dnsv4_server (dns_packet &pkt)
644	{	810	{
645	u16 flags = ntohs (pkt->flags);	811	u16 flags = ntohs (pkt.flags);
646		812
647	//memcpy (&((rep)[0]), &((pkt)[0]), pkt->len);
648	int offs = 6 * 2; // skip header	813	int offs = 6 * 2; // skip header
649		814
650	pkt->flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);	815	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);
651		816
652	if (0 == (flags & (FLAG_RESPONSE \| FLAG_OP_MASK \| FLAG_TC))	817	if (0 == (flags & (FLAG_RESPONSE \| FLAG_OP_MASK))
653	&& pkt->qdcount == htons (1))	818	&& pkt.qdcount == htons (1))
654	{	819	{
655	char qname[MAXSIZE];	820	char qname [MAXSIZE];
656	int qlen = pkt->decode_label ((char *)qname, MAXSIZE - offs, offs);	821	int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
657		822
658	u16 qtype = (pkt) [offs++] << 8; qtype \|= (pkt) [offs++];	823	u16 qtype = pkt [offs++] << 8; qtype \|= pkt [offs++];
659	u16 qclass = (pkt) [offs++] << 8; qclass \|= (pkt) [offs++];	824	u16 qclass = pkt [offs++] << 8; qclass \|= pkt [offs++];
660		825
661	pkt->qdcount = htons (1);	826	pkt.qdcount = htons (1);
662	pkt->ancount = 0;	827	pkt.ancount = 0;
663	pkt->nscount = 0; // should be self, as other nameservers reply like this	828	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	829	pkt.arcount = 0; // a record for self, as other nameservers reply like this
665		830
666	pkt->flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_NXDOMAIN);	831	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_SERVFAIL);
667		832
668	int dlen = strlen (THISNODE->domain);	833	int dlen = strlen (THISNODE->domain);
669		834
670	if (qclass == RR_CLASS_IN	835	if (qclass == RR_CLASS_IN
671	&& (qtype == RR_TYPE_ANY \|\| qtype == RR_TYPE_TXT)
672	&& qlen > dlen + 1 + HDRSIZE	836	&& qlen > dlen + 1
673	&& !memcmp (qname + qlen - dlen - 1, THISNODE->domain, dlen))	837	&& !memcmp (qname + qlen - (dlen + 1), THISNODE->domain, dlen))
674	{	838	{
675	// correct class, domain: parse	839	// now generate reply
676	int client, seqno;	840	pkt.ancount = htons (1); // one answer RR
677	decode_header (qname, client, seqno);	841	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_OK);
678		842
679	u8 data[MAXSIZE];	843	if ((qtype == RR_TYPE_ANY
680	int datalen = cdc62.decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE));	844	\|\| qtype == RR_TYPE_TXT
681		845	\|\| qtype == RR_TYPE_NULL)
682	if (0 < client && client <= conns.size ())	846	&& qlen > dlen + 1 + HDRSIZE)
683	{	847	{
		848	// correct class, domain: parse
		849	int client, seqno;
		850	decode_header (qname, client, seqno);
		851
		852	u8 data[MAXSIZE];
		853	int datalen = cdc62.decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE));
		854
		855	if (0 < client && client <= conns.size ())
		856	{
684	connection *c = conns [client - 1];	857	connection *c = conns [client - 1];
685
686	if (!c->dns)
687	c->dns = new dns_connection (c);
688
689	dns_connection *dns = c->dns;	858	dns_connection *dns = c->dns;
		859	dns_rcv *rcv;
		860	bool in_seq;
690		861
		862	if (dns)
		863	{
691	for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); )	864	for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); )
692	if (SEQNO_EQ ((*i)->seqno, seqno))	865	if (SEQNO_EQ ((*i)->seqno, seqno))
		866	{
		867	// already seen that request: simply reply with the cached reply
		868	dns_rcv r = i;
		869
		870	slog (L_DEBUG, "DNS: duplicate packet received ID %d, SEQ %d", htons (r->pkt->id), seqno);
		871
		872	// refresh header & id, as the retry count could have changed
		873	memcpy (r->pkt->at (6 * 2 + 1), pkt.at (6 * 2 + 1), HDRSIZE);
		874	r->pkt->id = pkt.id;
		875
		876	memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len);
		877
		878	goto duplicate_request;
		879	}
		880
		881	in_seq = dns->rcvseq == seqno;
		882
		883	// new packet, queue
		884	rcv = new dns_rcv (seqno, data, datalen);
		885	dns->receive_rep (rcv);
		886	}
		887
693	{	888	{
694	// already seen that request: simply reply with the cached reply	889	pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section
695	dns_rcv r = i;
696		890
697	printf ("DUPLICATE %d\n", htons (r->pkt->id));//D	891	int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A;
		892	pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type
		893	pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
		894	pkt [offs++] = 0; pkt [offs++] = 0;
		895	pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL
698		896
699	memcpy (pkt->at (0), r->pkt->at (0), offs = r->pkt->len);	897	int rdlen_offs = offs += 2;
700	pkt->id = r->pkt->id;	898
701	goto duplicate_request;	899	if (dns)
		900	{
		901	int dlen = ntohs (dns->cfg.max_size) - offs;
		902
		903	// bind doesn't compress well, so reduce further by one label length
		904	dlen -= qlen;
		905
		906	// only put data into in-order sequence packets, if
		907	// we receive out-of-order packets we generate empty
		908	// replies
		909	while (dlen > 1 && !dns->snddq.empty () && in_seq)
		910	{
		911	int txtlen = dlen <= 255 ? dlen - 1 : 255;
		912
		913	if (txtlen > dns->snddq.size ())
		914	txtlen = dns->snddq.size ();
		915
		916	pkt[offs++] = txtlen;
		917	memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
		918	offs += txtlen;
		919	dns->snddq.remove (txtlen);
		920
		921	dlen -= txtlen + 1;
		922	}
		923
		924	// avoid empty TXT rdata
		925	if (offs == rdlen_offs)
		926	pkt[offs++] = 0;
		927
		928	slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
		929	}
		930	else
		931	{
		932	// send RST
		933	pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
		934	pkt [offs++] = CMD_IP_RST;
		935	}
		936
		937	int rdlen = offs - rdlen_offs;
		938
		939	pkt [rdlen_offs - 2] = rdlen >> 8;
		940	pkt [rdlen_offs - 1] = rdlen;
		941
		942	if (dns)
		943	{
		944	// now update dns_rcv copy
		945	rcv->pkt->len = offs;
		946	memcpy (rcv->pkt->at (0), pkt.at (0), offs);
		947	}
702	}	948	}
703		949
704	// new packet, queue	950	duplicate_request: ;
705	dns_rcv *rcv = new dns_rcv (seqno, data, datalen);	951	}
706	dns->receive_rep (rcv);	952	else
707
708	// now generate reply
709	pkt->ancount = htons (1); // one answer RR
710	pkt->flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_OK);	953	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);
		954	}
		955	else if (qtype == RR_TYPE_A
		956	&& qlen > dlen + 1 + cdc26.encode_len (sizeof (dns_cfg)))
		957	{
		958	dns_cfg cfg;
		959	cdc26.decode ((u8 *)&cfg, qname, cdc26.encode_len (sizeof (dns_cfg)));
		960	int client = ntohs (cfg.client);
711		961
712	(*pkt) [offs++] = 0xc0;
713	(pkt) [offs++] = 6 2; // same as in query section	962	pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section
714		963
715	(pkt) [offs++] = RR_TYPE_TXT >> 8; (pkt) [offs++] = RR_TYPE_TXT;	964	pkt [offs++] = RR_TYPE_A >> 8; pkt [offs++] = RR_TYPE_A; // type
716	(pkt) [offs++] = RR_CLASS_IN >> 8; (pkt) [offs++] = RR_CLASS_IN;	965	pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
717
718	(pkt) [offs++] = 0; (pkt) [offs++] = 0;	966	pkt [offs++] = 0; pkt [offs++] = 0;
719	(pkt) [offs++] = 0; (pkt) [offs++] = 0; // TTL	967	pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL
		968	pkt [offs++] = 0; pkt [offs++] = 4; // rdlength
720		969
721	int dlen = MAX_PKT_SIZE - offs - 2;	970	slog (L_INFO, _("DNS: client %d connects"), client);
722		971
723	// bind doesn't compress well, so reduce further by one label length	972	pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
724	dlen -= qlen;	973	pkt [offs++] = CMD_IP_REJ;
725		974
726	int rdlen_offs = offs += 2;	975	if (0 < client && client <= conns.size ())
727
728	while (dlen > 1 && !dns->snddq.empty ())
729	{	976	{
730	int txtlen = dlen <= 255 ? dlen - 1 : 255;	977	connection *c = conns [client - 1];
731		978
732	if (txtlen > dns->snddq.size ())	979	if (cfg.valid ())
733	txtlen = dns->snddq.size ();	980	{
		981	pkt [offs - 1] = CMD_IP_SYN;
734		982
735	(*pkt)[offs++] = txtlen;	983	delete c->dns;
736	memcpy (pkt->at (offs), dns->snddq.begin (), txtlen);	984	c->dns = new dns_connection (c);
737	offs += txtlen;	985	c->dns->cfg = cfg;
738	dns->snddq.remove (txtlen);	986	}
739
740	dlen -= txtlen + 1;
741	}	987	}
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	}	988	}
758	else
759	pkt->flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);
760	}	989	}
761		990
762	pkt->len = offs;	991	pkt.len = offs;
763	}	992	}
764
765	return pkt;
766	}	993	}
767		994
768	void	995	void
769	vpn::dnsv4_client (dns_packet *pkt)	996	vpn::dnsv4_client (dns_packet &pkt)
770	{	997	{
771	u16 flags = ntohs (pkt->flags);	998	u16 flags = ntohs (pkt.flags);
772	int offs = 6 * 2; // skip header	999	int offs = 6 * 2; // skip header
773		1000
774	pkt->qdcount = ntohs (pkt->qdcount);	1001	pkt.qdcount = ntohs (pkt.qdcount);
775	pkt->ancount = ntohs (pkt->ancount);	1002	pkt.ancount = ntohs (pkt.ancount);
776		1003
777	// go through our request list and find the corresponding request	1004	// go through our request list and find the corresponding request
778	for (vector<dns_req *>::iterator i = dns_sndpq.begin ();	1005	for (vector<dns_snd *>::iterator i = dns_sndpq.begin ();
779	i != dns_sndpq.end ();	1006	i != dns_sndpq.end ();
780	++i)	1007	++i)
781	if ((*i)->pkt->id == pkt->id)	1008	if ((*i)->pkt->id == pkt.id)
782	{	1009	{
783	dns_connection dns = (i)->dns;	1010	dns_connection dns = (i)->dns;
		1011	connection *c = dns->c;
784	int seqno = (*i)->seqno;	1012	int seqno = (*i)->seqno;
785	u8 data[MAXSIZE], *datap = data;	1013	u8 data[MAXSIZE], *datap = data;
786		1014
		1015	if ((*i)->retry)
		1016	{
		1017	dns->send_interval *= 1.01;
		1018	if (dns->send_interval > MAX_SEND_INTERVAL)
		1019	dns->send_interval = MAX_SEND_INTERVAL;
		1020	}
		1021	else
		1022	{
		1023	#if 0
		1024	dns->send_interval *= 0.999;
		1025	#endif
		1026	// the latency surely puts an upper bound on
		1027	// the minimum send interval
		1028	double latency = NOW - (*i)->sent;
		1029
		1030	if (latency < dns->min_latency)
		1031	dns->min_latency = latency;
		1032
		1033	if (dns->send_interval > dns->min_latency * LATENCY_FACTOR)
		1034	dns->send_interval = dns->min_latency * LATENCY_FACTOR;
		1035
		1036	if (dns->send_interval < MIN_SEND_INTERVAL)
		1037	dns->send_interval = MIN_SEND_INTERVAL;
		1038	}
		1039
787	delete *i;	1040	delete *i;
788	dns_sndpq.erase (i);	1041	dns_sndpq.erase (i);
789		1042
790	if (flags & FLAG_RESPONSE && !(flags & (FLAG_OP_MASK \| FLAG_TC)))	1043	if (flags & FLAG_RESPONSE && !(flags & FLAG_OP_MASK))
791	{	1044	{
792	char qname[MAXSIZE];	1045	char qname[MAXSIZE];
793		1046
794	while (pkt->qdcount-- && offs < MAXSIZE - 4)	1047	while (pkt.qdcount-- && offs < MAXSIZE - 4)
795	{	1048	{
796	int qlen = pkt->decode_label ((char *)qname, MAXSIZE - offs, offs);	1049	int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
797	offs += 4; // skip qtype, qclass	1050	offs += 4; // skip qtype, qclass
798	}	1051	}
799		1052
800	while (pkt->ancount-- && offs < MAXSIZE - 10 && datap)	1053	while (pkt.ancount-- && offs < MAXSIZE - 10 && datap)
801	{	1054	{
802	int qlen = pkt->decode_label ((char *)qname, MAXSIZE - offs, offs);	1055	int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
803		1056
804	u16 qtype = (pkt) [offs++] << 8; qtype \|= (pkt) [offs++];	1057	u16 qtype = pkt [offs++] << 8; qtype \|= pkt [offs++];
805	u16 qclass = (pkt) [offs++] << 8; qclass \|= (pkt) [offs++];	1058	u16 qclass = pkt [offs++] << 8; qclass \|= pkt [offs++];
806	u32 ttl = (*pkt) [offs++] << 24;	1059	u32 ttl = pkt [offs++] << 24;
807	ttl \|= (*pkt) [offs++] << 16;	1060	ttl \|= pkt [offs++] << 16;
808	ttl \|= (*pkt) [offs++] << 8;	1061	ttl \|= pkt [offs++] << 8;
809	ttl \|= (*pkt) [offs++];	1062	ttl \|= pkt [offs++];
810
811	u16 rdlen = (pkt) [offs++] << 8; rdlen \|= (pkt) [offs++];	1063	u16 rdlen = pkt [offs++] << 8; rdlen \|= pkt [offs++];
812		1064
813	if (rdlen <= MAXSIZE - offs)	1065	if (qtype == RR_TYPE_NULL \|\| qtype == RR_TYPE_TXT)
814	{	1066	{
815	// decode bytes, finally	1067	if (rdlen <= MAXSIZE - offs)
816
817	while (rdlen)
818	{	1068	{
		1069	// decode bytes, finally
		1070
		1071	while (rdlen)
		1072	{
819	int txtlen = (*pkt) [offs++];	1073	int txtlen = pkt [offs++];
820		1074
821	assert (txtlen + offs < MAXSIZE - 1);	1075	assert (txtlen + offs < MAXSIZE - 1);
822		1076
823	memcpy (datap, pkt->at (offs), txtlen);	1077	memcpy (datap, pkt.at (offs), txtlen);
824	datap += txtlen; offs += txtlen;	1078	datap += txtlen; offs += txtlen;
825		1079
826	rdlen -= txtlen + 1;	1080	rdlen -= txtlen + 1;
		1081	}
827	}	1082	}
828	}	1083	}
		1084	else if (qtype == RR_TYPE_A)
		1085	{
		1086	u8 ip [4];
		1087
		1088	ip [0] = pkt [offs++];
		1089	ip [1] = pkt [offs++];
		1090	ip [2] = pkt [offs++];
		1091	ip [3] = pkt [offs++];
		1092
		1093	if (ip [0] == CMD_IP_1
		1094	&& ip [1] == CMD_IP_2
		1095	&& ip [2] == CMD_IP_3)
		1096	{
		1097	slog (L_TRACE, _("DNS: got tunnel meta command %02x"), ip [3]);
		1098
		1099	if (ip [3] == CMD_IP_RST)
		1100	{
		1101	slog (L_DEBUG, _("DNS: got tunnel RST request"));
		1102
		1103	delete dns; c->dns = 0;
		1104
		1105	return;
		1106	}
		1107	else if (ip [3] == CMD_IP_SYN)
		1108	{
		1109	slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us."));
		1110	dns->established = true;
		1111	}
		1112	else if (ip [3] == CMD_IP_REJ)
		1113	{
		1114	slog (L_DEBUG, _("DNS: got tunnel REJ reply, server does not like us, aborting."));
		1115	abort ();
		1116	}
		1117	else
		1118	slog (L_INFO, _("DNS: got unknown meta command %02x"), ip [3]);
		1119	}
		1120	else
		1121	slog (L_INFO, _("DNS: got spurious a record %d.%d.%d.%d"),
		1122	ip [0], ip [1], ip [2], ip [3]);
		1123
		1124	return;
		1125	}
829		1126
830	int client, rseqno;	1127	int client, rseqno;
831	decode_header (qname, client, rseqno);	1128	decode_header (qname, client, rseqno);
832		1129
833	if (client != THISNODE->id)	1130	if (client != THISNODE->id)
834	{	1131	{
835	slog (L_INFO, _("got dns tunnel response with wrong clientid, ignoring"));	1132	slog (L_INFO, _("DNS: got dns tunnel response with wrong clientid, ignoring"));
836	datap = 0;	1133	datap = 0;
837	}	1134	}
838	else if (rseqno != seqno)	1135	else if (rseqno != seqno)
839	{	1136	{
840	slog (L_DEBUG, _("got dns tunnel response with wrong seqno, badly caching nameserver?"));	1137	slog (L_DEBUG, _("DNS: got dns tunnel response with wrong seqno, badly caching nameserver?"));
841	datap = 0;	1138	datap = 0;
842	}	1139	}
843	}	1140	}
844	}	1141	}
845		1142
…		…
847	if (datap)	1144	if (datap)
848	dns->receive_rep (new dns_rcv (seqno, data, datap - data));	1145	dns->receive_rep (new dns_rcv (seqno, data, datap - data));
849		1146
850	break;	1147	break;
851	}	1148	}
852
853	delete pkt;
854	}	1149	}
855		1150
856	void	1151	void
857	vpn::dnsv4_ev (io_watcher &w, short revents)	1152	vpn::dnsv4_ev (io_watcher &w, short revents)
858	{	1153	{
…		…
860	{	1155	{
861	dns_packet *pkt = new dns_packet;	1156	dns_packet *pkt = new dns_packet;
862	struct sockaddr_in sa;	1157	struct sockaddr_in sa;
863	socklen_t sa_len = sizeof (sa);	1158	socklen_t sa_len = sizeof (sa);
864		1159
865	pkt->len = recvfrom (w.fd, &((pkt)[0]), MAXSIZE, 0, (sockaddr )&sa, &sa_len);	1160	pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len);
866		1161
867	if (pkt->len > 0)	1162	if (pkt->len > 0)
868	{	1163	{
869	if (pkt->flags & htons (FLAG_TC))	1164	if (ntohs (pkt->flags) & FLAG_RESPONSE)
		1165	dnsv4_client (*pkt);
		1166	else
870	{	1167	{
871	slog (L_WARN, _("DNS request/response truncated, check protocol settings."));	1168	dnsv4_server (*pkt);
872	//TODO connection reset	1169	sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len);
873	}	1170	}
874		1171
875	if (THISNODE->dns_port)	1172	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	}	1173	}
883	}	1174	}
884	}	1175	}
885		1176
886	bool	1177	bool
887	connection::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)	1178	vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
888	{	1179	{
		1180	int client = ntohs (si.port);
		1181
		1182	assert (0 < client && client <= conns.size ());
		1183
		1184	connection *c = conns [client - 1];
		1185
889	if (!dns)	1186	if (!c->dns)
890	dns = new dns_connection (this);	1187	c->dns = new dns_connection (c);
891		1188
892	if (!dns->snddq.put (pkt))	1189	if (!c->dns->snddq.put (pkt))
893	return false;	1190	return false;
894		1191
895	// start timer if neccessary
896	if (!THISNODE->dns_port && !dns->tw.active)
897	dns->tw.trigger ();	1192	c->dns->tw.trigger ();
898		1193
899	return true;	1194	return true;
900	}	1195	}
		1196
		1197	void
		1198	connection::dnsv4_reset_connection ()
		1199	{
		1200	//delete dns; dns = 0; //TODO
		1201	}
		1202
		1203	#define NEXT(w) do { if (next > (w)) next = w; } while (0)
901		1204
902	void	1205	void
903	dns_connection::time_cb (time_watcher &w)	1206	dns_connection::time_cb (time_watcher &w)
904	{	1207	{
		1208	// servers have to be polled
		1209	if (THISNODE->dns_port)
		1210	return;
		1211
905	// check for timeouts and (re)transmit	1212	// check for timeouts and (re)transmit
906	tstamp next = NOW + 60;	1213	tstamp next = NOW + poll_interval;
907	dns_req *send = 0;	1214	dns_snd *send = 0;
908		1215
909	for (vector<dns_req *>::iterator i = vpn->dns_sndpq.begin ();	1216	for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin ();
910	i != vpn->dns_sndpq.end ();	1217	i != vpn->dns_sndpq.end ();
911	++i)	1218	++i)
912	{	1219	{
913	dns_req r = i;	1220	dns_snd r = i;
914		1221
915	if (r->next <= NOW)	1222	if (r->timeout <= NOW)
916	{	1223	{
917	if (!send)	1224	if (!send)
918	{	1225	{
919	send = r;	1226	send = r;
920		1227
921	if (r->retry)//D
922	printf ("req %d:%d, retry %d\n", r->seqno, r->pkt->id, r->retry);
923	r->retry++;	1228	r->retry++;
924	r->next = NOW + r->retry;	1229	r->timeout = NOW + (r->retry * min_latency * 8.);
		1230
		1231	// the following code changes the query section a bit, forcing
		1232	// the forwarder to generate a new request
		1233	if (r->stdhdr)
		1234	{
		1235	//printf ("reencoded header for ID %d retry %d:%d:%d (%p)\n", htons (r->pkt->id), THISNODE->id, r->seqno, r->retry);
		1236	//encode_header ((char )r->pkt->at (6 2 + 1), THISNODE->id, r->seqno, r->retry);
		1237	}
925	}	1238	}
926	}	1239	}
927		1240	else
928	if (r->next < next)	1241	NEXT (r->timeout);
929	next = r->next;
930	}	1242	}
931		1243
932	if (!send	1244	if (!send)
		1245	{
		1246	// generate a new packet, if wise
		1247
		1248	if (!established)
		1249	{
		1250	if (vpn->dns_sndpq.empty ())
		1251	{
		1252	send = new dns_snd (this);
		1253
		1254	cfg.reset (THISNODE->id);
		1255	send->gen_syn_req ();
		1256	}
		1257	}
933	&& vpn->dns_sndpq.size () < MAX_OUTSTANDING)	1258	else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING
934	{	1259	&& !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
		1260	{
		1261	if (last_sent + send_interval <= NOW)
		1262	{
		1263	//printf ("sending data request etc.\n"); //D
		1264	if (!snddq.empty () \|\| last_received + 1. > NOW)
		1265	{
		1266	poll_interval = send_interval;
		1267	NEXT (NOW + send_interval);
		1268	}
		1269
935	send = new dns_req (this);	1270	send = new dns_snd (this);
936	send->gen_stream_req (sndseq, snddq);	1271	send->gen_stream_req (sndseq, snddq);
		1272	send->timeout = NOW + min_latency * 8.;
		1273
		1274	sndseq = (sndseq + 1) & SEQNO_MASK;
		1275	}
		1276	else
		1277	NEXT (last_sent + send_interval);
		1278	}
		1279
		1280	if (send)
937	vpn->dns_sndpq.push_back (send);	1281	vpn->dns_sndpq.push_back (send);
938
939	sndseq = (sndseq + 1) & SEQNO_MASK;
940	}	1282	}
941
942	tstamp min_next = NOW + (1. / (tstamp)MAX_RATE);
943		1283
944	if (send)	1284	if (send)
945	{	1285	{
946	dns_packet *pkt = send->pkt;	1286	last_sent = NOW;
947		1287	sendto (vpn->dnsv4_fd,
948	next = min_next;	1288	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 ());	1289	vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
952	}	1290	}
953	else if (next < min_next)	1291
954	next = min_next;	1292	slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)",
		1293	poll_interval, send_interval, next - NOW,
		1294	vpn->dns_sndpq.size (), snddq.size (),
		1295	rcvpq.size ());
		1296
		1297	// TODO: no idea when this happens, but when next < NOW, we have a problem
		1298	if (next < NOW + 0.001)
		1299	next = NOW + 0.1;
955		1300
956	w.start (next);	1301	w.start (next);
957	}	1302	}
958		1303
959	#endif	1304	#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 1.30 by pcg, Mon Mar 14 17:40:01 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 1.30 by pcg, Mon Mar 14 17:40:01 2005 UTC