[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 1.24 by pcg, Mon Mar 7 01:31:26 2005 UTC

…		…
25		25
26	// dns processing is EXTREMELY ugly. For obvious(?) reasons.	26	// dns processing is EXTREMELY ugly. For obvious(?) reasons.
27	// it's a hack, use only in emergency situations please.	27	// it's a hack, use only in emergency situations please.
28		28
29	#include <cstring>	29	#include <cstring>
		30	#include <cassert>
30		31
31	#include <sys/types.h>	32	#include <sys/types.h>
32	#include <sys/socket.h>	33	#include <sys/socket.h>
33	#include <sys/wait.h>	34	#include <sys/wait.h>
34	#include <sys/uio.h>	35	#include <sys/uio.h>
…		…
43		44
44	#include "netcompat.h"	45	#include "netcompat.h"
45		46
46	#include "vpn.h"	47	#include "vpn.h"
47		48
48	#define MIN_RETRY 1.	49	#define MIN_POLL_INTERVAL .02 // how often to poll minimally when the server has data
49	#define MAX_RETRY 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 0.5 // optimistic?
		58
51	#define MAX_OUTSTANDING 400 // max. outstanding requests	59	#define MAX_OUTSTANDING 10 // max. outstanding requests
52	#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING	60	#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog
53	#define MAX_RATE 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 220 // 255 is legal limit, but bind doesn't compress well
57	// 240 leaves about 4 bytes of server reply data	64	// 240 leaves about 4 bytes of server reply data
58	// every two request byte sless give room for one reply byte	65	// every two request bytes less give room for one reply byte
59		66
60	#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 r2, r3, r4;
		429
		430	u8 r5, r6, r7, r8;
		431
		432	void reset (int clientid);
		433	bool valid ();
		434	};
		435
		436	int dns_cfg::next_uid;
		437
		438	void dns_cfg::reset (int clientid)
		439	{
		440	id1 = 'G';
		441	id2 = 'V';
		442	id3 = 'P';
		443	id4 = 'E';
		444
		445	version = 1;
		446
		447	rrtype = RR_TYPE_TXT;
		448	flags = 0;
		449	def_ttl = 0;
		450	seq_cdc = 26;
		451	req_cdc = 62;
		452	rep_cdc = 0;
		453	max_size = ntohs (MAX_PKT_SIZE);
		454	client = ntohs (clientid);
		455	uid = next_uid++;
		456
		457	r2 = r3 = r4 = 0;
		458	r4 = r5 = r6 = r7 = 0;
		459	}
		460
		461	bool dns_cfg::valid ()
		462	{
		463	return id1 == 'G'
		464	&& id2 == 'V'
		465	&& id3 == 'P'
		466	&& id4 == 'E'
		467	&& seq_cdc == 26
		468	&& req_cdc == 62
		469	&& rep_cdc == 0
		470	&& version == 1
		471	&& max_size == ntohs (MAX_PKT_SIZE);
		472	}
		473
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 last_latency;
		553	double poll_interval, send_interval;
		554
		555	vector<dns_rcv *> rcvpq;
		556
		557	byte_stream rcvdq; int rcvseq;
		558	byte_stream snddq; int sndseq;
		559
		560	void time_cb (time_watcher &w); time_watcher tw;
		561	void receive_rep (dns_rcv *r);
		562
		563	dns_connection (connection *c);
		564	~dns_connection ();
		565	};
		566
		567	struct dns_snd
		568	{
		569	dns_packet *pkt;
		570	tstamp timeout, sent;
		571	int retry;
		572	struct dns_connection *dns;
		573	int seqno;
		574	bool stdhdr;
		575
		576	void gen_stream_req (int seqno, byte_stream &stream);
		577	void gen_syn_req ();
		578
		579	dns_snd (dns_connection *dns);
		580	~dns_snd ();
		581	};
		582
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	last_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	if (poll_interval > MAX_POLL_INTERVAL)
		760	poll_interval = MAX_POLL_INTERVAL;
		761	}
		762
604	rcvpq.push_back (r);	763	rcvpq.push_back (r);
605		764
606	redo:	765	redo:
607		766
608	// find next packet	767	// find next packet
…		…
622	}	781	}
623		782
624	rcvseq = (rcvseq + 1) & SEQNO_MASK;	783	rcvseq = (rcvseq + 1) & SEQNO_MASK;
625		784
626	if (!rcvdq.put (r->data, r->datalen))	785	if (!rcvdq.put (r->data, r->datalen))
		786	{
		787	slog (L_ERR, "DNS: !rcvdq.put (r->data, r->datalen)");
627	abort (); // MUST never overflow, can be caused by data corruption, TODO	788	abort (); // MUST never overflow, can be caused by data corruption, TODO
		789	}
628		790
629	while (vpn_packet *pkt = rcvdq.get ())	791	while (vpn_packet *pkt = rcvdq.get ())
630	{	792	{
631	sockinfo si;	793	sockinfo si;
632	si.host = 0; si.port = 0; si.prot = PROT_DNSv4;	794	si.host = 0x01010101; si.port = htons (c->conf->id); si.prot = PROT_DNSv4;
633		795
634	vpn->recv_vpn_packet (pkt, si);	796	vpn->recv_vpn_packet (pkt, si);
		797
		798	delete pkt;
635	}	799	}
636		800
637	// check for further packets	801	// check for further packets
638	goto redo;	802	goto redo;
639	}	803	}
640	}	804	}
641		805
642	dns_packet *	806	void
643	vpn::dnsv4_server (dns_packet *pkt)	807	vpn::dnsv4_server (dns_packet &pkt)
644	{	808	{
645	u16 flags = ntohs (pkt->flags);	809	u16 flags = ntohs (pkt.flags);
646		810
647	//memcpy (&((rep)[0]), &((pkt)[0]), pkt->len);
648	int offs = 6 * 2; // skip header	811	int offs = 6 * 2; // skip header
649		812
650	pkt->flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);	813	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);
651		814
652	if (0 == (flags & (FLAG_RESPONSE \| FLAG_OP_MASK \| FLAG_TC))	815	if (0 == (flags & (FLAG_RESPONSE \| FLAG_OP_MASK))
653	&& pkt->qdcount == htons (1))	816	&& pkt.qdcount == htons (1))
654	{	817	{
655	char qname[MAXSIZE];	818	char qname [MAXSIZE];
656	int qlen = pkt->decode_label ((char *)qname, MAXSIZE - offs, offs);	819	int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
657		820
658	u16 qtype = (pkt) [offs++] << 8; qtype \|= (pkt) [offs++];	821	u16 qtype = pkt [offs++] << 8; qtype \|= pkt [offs++];
659	u16 qclass = (pkt) [offs++] << 8; qclass \|= (pkt) [offs++];	822	u16 qclass = pkt [offs++] << 8; qclass \|= pkt [offs++];
660		823
661	pkt->qdcount = htons (1);	824	pkt.qdcount = htons (1);
662	pkt->ancount = 0;	825	pkt.ancount = 0;
663	pkt->nscount = 0; // should be self, as other nameservers reply like this	826	pkt.nscount = 0; // should be self, as other nameservers reply like this
664	pkt->arcount = 0; // a record for self, as other nameservers reply like this	827	pkt.arcount = 0; // a record for self, as other nameservers reply like this
665		828
666	pkt->flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_NXDOMAIN);	829	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_SERVFAIL);
667		830
668	int dlen = strlen (THISNODE->domain);	831	int dlen = strlen (THISNODE->domain);
669		832
670	if (qclass == RR_CLASS_IN	833	if (qclass == RR_CLASS_IN
671	&& (qtype == RR_TYPE_ANY \|\| qtype == RR_TYPE_TXT)
672	&& qlen > dlen + 1 + HDRSIZE	834	&& qlen > dlen + 1
673	&& !memcmp (qname + qlen - dlen - 1, THISNODE->domain, dlen))	835	&& !memcmp (qname + qlen - (dlen + 1), THISNODE->domain, dlen))
674	{	836	{
675	// correct class, domain: parse	837	// now generate reply
676	int client, seqno;	838	pkt.ancount = htons (1); // one answer RR
677	decode_header (qname, client, seqno);	839	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_OK);
678		840
679	u8 data[MAXSIZE];	841	if ((qtype == RR_TYPE_ANY
680	int datalen = cdc62.decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE));	842	\|\| qtype == RR_TYPE_TXT
681		843	\|\| qtype == RR_TYPE_NULL)
682	if (0 < client && client <= conns.size ())	844	&& qlen > dlen + 1 + HDRSIZE)
683	{	845	{
		846	// correct class, domain: parse
		847	int client, seqno;
		848	decode_header (qname, client, seqno);
		849
		850	u8 data[MAXSIZE];
		851	int datalen = cdc62.decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE));
		852
		853	if (0 < client && client <= conns.size ())
		854	{
684	connection *c = conns [client - 1];	855	connection *c = conns [client - 1];
685
686	if (!c->dns)
687	c->dns = new dns_connection (c);
688
689	dns_connection *dns = c->dns;	856	dns_connection *dns = c->dns;
		857	dns_rcv *rcv;
		858	bool in_seq;
690		859
		860	if (dns)
		861	{
691	for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); )	862	for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); )
692	if (SEQNO_EQ ((*i)->seqno, seqno))	863	if (SEQNO_EQ ((*i)->seqno, seqno))
		864	{
		865	// already seen that request: simply reply with the cached reply
		866	dns_rcv r = i;
		867
		868	slog (L_DEBUG, "DNS: duplicate packet received ID %d, SEQ %d", htons (r->pkt->id), seqno);
		869
		870	// refresh header & id, as the retry count could have changed
		871	memcpy (r->pkt->at (6 * 2 + 1), pkt.at (6 * 2 + 1), HDRSIZE);
		872	r->pkt->id = pkt.id;
		873
		874	memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len);
		875
		876	goto duplicate_request;
		877	}
		878
		879	in_seq = dns->rcvseq == seqno;
		880
		881	// new packet, queue
		882	rcv = new dns_rcv (seqno, data, datalen);
		883	dns->receive_rep (rcv);
		884	}
		885
693	{	886	{
694	// already seen that request: simply reply with the cached reply	887	pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section
695	dns_rcv r = i;
696		888
697	printf ("DUPLICATE %d\n", htons (r->pkt->id));//D	889	int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A;
		890	pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type
		891	pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
		892	pkt [offs++] = 0; pkt [offs++] = 0;
		893	pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL
698		894
699	memcpy (pkt->at (0), r->pkt->at (0), offs = r->pkt->len);	895	int rdlen_offs = offs += 2;
700	pkt->id = r->pkt->id;	896
701	goto duplicate_request;	897	int dlen = (dns ? ntohs (dns->cfg.max_size) : MAX_PKT_SIZE) - offs;
		898	// bind doesn't compress well, so reduce further by one label length
		899	dlen -= qlen;
		900
		901	if (dns)
		902	{
		903	// only put data into in-order sequence packets, if
		904	// we receive out-of-order packets we generate empty
		905	// replies
		906	while (dlen > 1 && !dns->snddq.empty () && in_seq)
		907	{
		908	int txtlen = dlen <= 255 ? dlen - 1 : 255;
		909
		910	if (txtlen > dns->snddq.size ())
		911	txtlen = dns->snddq.size ();
		912
		913	pkt[offs++] = txtlen;
		914	memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
		915	offs += txtlen;
		916	dns->snddq.remove (txtlen);
		917
		918	dlen -= txtlen + 1;
		919	}
		920
		921	// avoid empty TXT rdata
		922	if (offs == rdlen_offs)
		923	pkt[offs++] = 0;
		924
		925	slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
		926	}
		927	else
		928	{
		929	// send RST
		930	pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
		931	pkt [offs++] = CMD_IP_RST;
		932	}
		933
		934	int rdlen = offs - rdlen_offs;
		935
		936	pkt [rdlen_offs - 2] = rdlen >> 8;
		937	pkt [rdlen_offs - 1] = rdlen;
		938
		939	if (dns)
		940	{
		941	// now update dns_rcv copy
		942	rcv->pkt->len = offs;
		943	memcpy (rcv->pkt->at (0), pkt.at (0), offs);
		944	}
702	}	945	}
703		946
704	// new packet, queue	947	duplicate_request: ;
705	dns_rcv *rcv = new dns_rcv (seqno, data, datalen);	948	}
706	dns->receive_rep (rcv);	949	else
707
708	// now generate reply
709	pkt->ancount = htons (1); // one answer RR
710	pkt->flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_OK);	950	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);
		951	}
		952	else if (qtype == RR_TYPE_A
		953	&& qlen > dlen + 1 + cdc26.encode_len (sizeof (dns_cfg)))
		954	{
		955	dns_cfg cfg;
		956	cdc26.decode ((u8 *)&cfg, qname, cdc26.encode_len (sizeof (dns_cfg)));
		957	int client = ntohs (cfg.client);
711		958
712	(*pkt) [offs++] = 0xc0;
713	(pkt) [offs++] = 6 2; // same as in query section	959	pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section
714		960
715	(pkt) [offs++] = RR_TYPE_TXT >> 8; (pkt) [offs++] = RR_TYPE_TXT;	961	pkt [offs++] = RR_TYPE_A >> 8; pkt [offs++] = RR_TYPE_A; // type
716	(pkt) [offs++] = RR_CLASS_IN >> 8; (pkt) [offs++] = RR_CLASS_IN;	962	pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
717
718	(pkt) [offs++] = 0; (pkt) [offs++] = 0;	963	pkt [offs++] = 0; pkt [offs++] = 0;
719	(pkt) [offs++] = 0; (pkt) [offs++] = 0; // TTL	964	pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL
		965	pkt [offs++] = 0; pkt [offs++] = 4; // rdlength
720		966
721	int dlen = MAX_PKT_SIZE - offs - 2;	967	slog (L_INFO, _("DNS: client %d connects"), client);
722		968
723	// bind doesn't compress well, so reduce further by one label length	969	pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
724	dlen -= qlen;	970	pkt [offs++] = CMD_IP_REJ;
725		971
726	int rdlen_offs = offs += 2;	972	if (0 < client && client <= conns.size ())
727
728	while (dlen > 1 && !dns->snddq.empty ())
729	{	973	{
730	int txtlen = dlen <= 255 ? dlen - 1 : 255;	974	connection *c = conns [client - 1];
731		975
732	if (txtlen > dns->snddq.size ())	976	if (cfg.valid ())
733	txtlen = dns->snddq.size ();	977	{
		978	pkt [offs - 1] = CMD_IP_SYN;
734		979
735	(*pkt)[offs++] = txtlen;	980	delete c->dns;
736	memcpy (pkt->at (offs), dns->snddq.begin (), txtlen);	981	c->dns = new dns_connection (c);
737	offs += txtlen;	982	c->dns->cfg = cfg;
738	dns->snddq.remove (txtlen);	983	}
739
740	dlen -= txtlen + 1;
741	}	984	}
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	}	985	}
758	else
759	pkt->flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);
760	}	986	}
761		987
762	pkt->len = offs;	988	pkt.len = offs;
763	}	989	}
764
765	return pkt;
766	}	990	}
767		991
768	void	992	void
769	vpn::dnsv4_client (dns_packet *pkt)	993	vpn::dnsv4_client (dns_packet &pkt)
770	{	994	{
771	u16 flags = ntohs (pkt->flags);	995	u16 flags = ntohs (pkt.flags);
772	int offs = 6 * 2; // skip header	996	int offs = 6 * 2; // skip header
773		997
774	pkt->qdcount = ntohs (pkt->qdcount);	998	pkt.qdcount = ntohs (pkt.qdcount);
775	pkt->ancount = ntohs (pkt->ancount);	999	pkt.ancount = ntohs (pkt.ancount);
776		1000
777	// go through our request list and find the corresponding request	1001	// go through our request list and find the corresponding request
778	for (vector<dns_req *>::iterator i = dns_sndpq.begin ();	1002	for (vector<dns_snd *>::iterator i = dns_sndpq.begin ();
779	i != dns_sndpq.end ();	1003	i != dns_sndpq.end ();
780	++i)	1004	++i)
781	if ((*i)->pkt->id == pkt->id)	1005	if ((*i)->pkt->id == pkt.id)
782	{	1006	{
783	dns_connection dns = (i)->dns;	1007	dns_connection dns = (i)->dns;
		1008	connection *c = dns->c;
784	int seqno = (*i)->seqno;	1009	int seqno = (*i)->seqno;
785	u8 data[MAXSIZE], *datap = data;	1010	u8 data[MAXSIZE], *datap = data;
786		1011
		1012	if ((*i)->retry)
		1013	{
		1014	dns->send_interval *= 1.01;
		1015	if (dns->send_interval > MAX_SEND_INTERVAL)
		1016	dns->send_interval = MAX_SEND_INTERVAL;
		1017	}
		1018	else
		1019	{
		1020	#if 1
		1021	dns->send_interval *= 0.999;
		1022	#endif
		1023	if (dns->send_interval < MIN_SEND_INTERVAL)
		1024	dns->send_interval = MIN_SEND_INTERVAL;
		1025
		1026	// the latency surely puts an upper bound on
		1027	// the minimum send interval
		1028	double latency = NOW - (*i)->sent;
		1029	dns->last_latency = latency;
		1030
		1031	if (dns->send_interval > latency)
		1032	dns->send_interval = latency;
		1033	}
		1034
787	delete *i;	1035	delete *i;
788	dns_sndpq.erase (i);	1036	dns_sndpq.erase (i);
789		1037
790	if (flags & FLAG_RESPONSE && !(flags & (FLAG_OP_MASK \| FLAG_TC)))	1038	if (flags & FLAG_RESPONSE && !(flags & FLAG_OP_MASK))
791	{	1039	{
792	char qname[MAXSIZE];	1040	char qname[MAXSIZE];
793		1041
794	while (pkt->qdcount-- && offs < MAXSIZE - 4)	1042	while (pkt.qdcount-- && offs < MAXSIZE - 4)
795	{	1043	{
796	int qlen = pkt->decode_label ((char *)qname, MAXSIZE - offs, offs);	1044	int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
797	offs += 4; // skip qtype, qclass	1045	offs += 4; // skip qtype, qclass
798	}	1046	}
799		1047
800	while (pkt->ancount-- && offs < MAXSIZE - 10 && datap)	1048	while (pkt.ancount-- && offs < MAXSIZE - 10 && datap)
801	{	1049	{
802	int qlen = pkt->decode_label ((char *)qname, MAXSIZE - offs, offs);	1050	int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
803		1051
804	u16 qtype = (pkt) [offs++] << 8; qtype \|= (pkt) [offs++];	1052	u16 qtype = pkt [offs++] << 8; qtype \|= pkt [offs++];
805	u16 qclass = (pkt) [offs++] << 8; qclass \|= (pkt) [offs++];	1053	u16 qclass = pkt [offs++] << 8; qclass \|= pkt [offs++];
806	u32 ttl = (*pkt) [offs++] << 24;	1054	u32 ttl = pkt [offs++] << 24;
807	ttl \|= (*pkt) [offs++] << 16;	1055	ttl \|= pkt [offs++] << 16;
808	ttl \|= (*pkt) [offs++] << 8;	1056	ttl \|= pkt [offs++] << 8;
809	ttl \|= (*pkt) [offs++];	1057	ttl \|= pkt [offs++];
810
811	u16 rdlen = (pkt) [offs++] << 8; rdlen \|= (pkt) [offs++];	1058	u16 rdlen = pkt [offs++] << 8; rdlen \|= pkt [offs++];
812		1059
813	if (rdlen <= MAXSIZE - offs)	1060	if (qtype == RR_TYPE_NULL \|\| qtype == RR_TYPE_TXT)
814	{	1061	{
815	// decode bytes, finally	1062	if (rdlen <= MAXSIZE - offs)
816
817	while (rdlen)
818	{	1063	{
		1064	// decode bytes, finally
		1065
		1066	while (rdlen)
		1067	{
819	int txtlen = (*pkt) [offs++];	1068	int txtlen = pkt [offs++];
820		1069
821	assert (txtlen + offs < MAXSIZE - 1);	1070	assert (txtlen + offs < MAXSIZE - 1);
822		1071
823	memcpy (datap, pkt->at (offs), txtlen);	1072	memcpy (datap, pkt.at (offs), txtlen);
824	datap += txtlen; offs += txtlen;	1073	datap += txtlen; offs += txtlen;
825		1074
826	rdlen -= txtlen + 1;	1075	rdlen -= txtlen + 1;
		1076	}
827	}	1077	}
828	}	1078	}
		1079	else if (qtype == RR_TYPE_A)
		1080	{
		1081	u8 ip [4];
		1082
		1083	ip [0] = pkt [offs++];
		1084	ip [1] = pkt [offs++];
		1085	ip [2] = pkt [offs++];
		1086	ip [3] = pkt [offs++];
		1087
		1088	if (ip [0] == CMD_IP_1
		1089	&& ip [1] == CMD_IP_2
		1090	&& ip [2] == CMD_IP_3)
		1091	{
		1092	slog (L_TRACE, _("DNS: got tunnel meta command %02x"), ip [3]);
		1093
		1094	if (ip [3] == CMD_IP_RST)
		1095	{
		1096	slog (L_DEBUG, _("DNS: got tunnel RST request"));
		1097
		1098	delete dns; c->dns = 0;
		1099
		1100	return;
		1101	}
		1102	else if (ip [3] == CMD_IP_SYN)
		1103	{
		1104	slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us."));
		1105	dns->established = true;
		1106	}
		1107	else if (ip [3] == CMD_IP_REJ)
		1108	{
		1109	slog (L_DEBUG, _("DNS: got tunnel REJ reply, server does not like us, aborting."));
		1110	abort ();
		1111	}
		1112	else
		1113	slog (L_INFO, _("DNS: got unknown meta command %02x"), ip [3]);
		1114	}
		1115	else
		1116	slog (L_INFO, _("DNS: got spurious a record %d.%d.%d.%d"),
		1117	ip [0], ip [1], ip [2], ip [3]);
		1118
		1119	return;
		1120	}
829		1121
830	int client, rseqno;	1122	int client, rseqno;
831	decode_header (qname, client, rseqno);	1123	decode_header (qname, client, rseqno);
832		1124
833	if (client != THISNODE->id)	1125	if (client != THISNODE->id)
834	{	1126	{
835	slog (L_INFO, _("got dns tunnel response with wrong clientid, ignoring"));	1127	slog (L_INFO, _("DNS: got dns tunnel response with wrong clientid, ignoring"));
836	datap = 0;	1128	datap = 0;
837	}	1129	}
838	else if (rseqno != seqno)	1130	else if (rseqno != seqno)
839	{	1131	{
840	slog (L_DEBUG, _("got dns tunnel response with wrong seqno, badly caching nameserver?"));	1132	slog (L_DEBUG, _("DNS: got dns tunnel response with wrong seqno, badly caching nameserver?"));
841	datap = 0;	1133	datap = 0;
842	}	1134	}
843	}	1135	}
844	}	1136	}
845		1137
…		…
847	if (datap)	1139	if (datap)
848	dns->receive_rep (new dns_rcv (seqno, data, datap - data));	1140	dns->receive_rep (new dns_rcv (seqno, data, datap - data));
849		1141
850	break;	1142	break;
851	}	1143	}
852
853	delete pkt;
854	}	1144	}
855		1145
856	void	1146	void
857	vpn::dnsv4_ev (io_watcher &w, short revents)	1147	vpn::dnsv4_ev (io_watcher &w, short revents)
858	{	1148	{
…		…
860	{	1150	{
861	dns_packet *pkt = new dns_packet;	1151	dns_packet *pkt = new dns_packet;
862	struct sockaddr_in sa;	1152	struct sockaddr_in sa;
863	socklen_t sa_len = sizeof (sa);	1153	socklen_t sa_len = sizeof (sa);
864		1154
865	pkt->len = recvfrom (w.fd, &((pkt)[0]), MAXSIZE, 0, (sockaddr )&sa, &sa_len);	1155	pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len);
866		1156
867	if (pkt->len > 0)	1157	if (pkt->len > 0)
868	{	1158	{
869	if (pkt->flags & htons (FLAG_TC))	1159	if (ntohs (pkt->flags) & FLAG_RESPONSE)
		1160	dnsv4_client (*pkt);
		1161	else
870	{	1162	{
871	slog (L_WARN, _("DNS request/response truncated, check protocol settings."));	1163	dnsv4_server (*pkt);
872	//TODO connection reset	1164	sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len);
873	}	1165	}
874		1166
875	if (THISNODE->dns_port)	1167	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	}	1168	}
883	}	1169	}
884	}	1170	}
885		1171
886	bool	1172	bool
887	connection::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)	1173	vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
888	{	1174	{
		1175	int client = ntohs (si.port);
		1176
		1177	assert (0 < client && client <= conns.size ());
		1178
		1179	connection *c = conns [client - 1];
		1180
889	if (!dns)	1181	if (!c->dns)
890	dns = new dns_connection (this);	1182	c->dns = new dns_connection (c);
891		1183
892	if (!dns->snddq.put (pkt))	1184	if (!c->dns->snddq.put (pkt))
893	return false;	1185	return false;
894		1186
895	// start timer if neccessary
896	if (!THISNODE->dns_port && !dns->tw.active)
897	dns->tw.trigger ();	1187	c->dns->tw.trigger ();
898		1188
899	return true;	1189	return true;
900	}	1190	}
		1191
		1192	void
		1193	connection::dnsv4_reset_connection ()
		1194	{
		1195	//delete dns; dns = 0; //TODO
		1196	}
		1197
		1198	#define NEXT(w) do { if (next > (w)) next = w; } while (0)
901		1199
902	void	1200	void
903	dns_connection::time_cb (time_watcher &w)	1201	dns_connection::time_cb (time_watcher &w)
904	{	1202	{
		1203	// servers have to be polled
		1204	if (THISNODE->dns_port)
		1205	return;
		1206
905	// check for timeouts and (re)transmit	1207	// check for timeouts and (re)transmit
906	tstamp next = NOW + 60;	1208	tstamp next = NOW + poll_interval;
907	dns_req *send = 0;	1209	dns_snd *send = 0;
908		1210
909	for (vector<dns_req *>::iterator i = vpn->dns_sndpq.begin ();	1211	for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin ();
910	i != vpn->dns_sndpq.end ();	1212	i != vpn->dns_sndpq.end ();
911	++i)	1213	++i)
912	{	1214	{
913	dns_req r = i;	1215	dns_snd r = i;
914		1216
915	if (r->next <= NOW)	1217	if (r->timeout <= NOW)
916	{	1218	{
917	if (!send)	1219	if (!send)
918	{	1220	{
919	send = r;	1221	send = r;
920		1222
921	if (r->retry)//D
922	printf ("req %d:%d, retry %d\n", r->seqno, r->pkt->id, r->retry);
923	r->retry++;	1223	r->retry++;
924	r->next = NOW + r->retry;	1224	r->timeout = NOW + (r->retry * last_latency * 8.);
		1225
		1226	// the following code changes the query section a bit, forcing
		1227	// the forwarder to generate a new request
		1228	if (r->stdhdr)
		1229	{
		1230	//printf ("reencoded header for ID %d retry %d:%d:%d\n", htons (r->pkt->id), THISNODE->id, r->seqno, r->retry);printf ("reencoded header for ID %d retry %d:%d:%d\n", htons (r->pkt->id), THISNODE->id, r->seqno, r->retry);
		1231	//encode_header ((char )r->pkt->at (6 2 + 1), THISNODE->id, r->seqno, r->retry);
		1232	}
925	}	1233	}
926	}	1234	}
		1235	else
		1236	NEXT (r->timeout);
		1237	}
927		1238
928	if (r->next < next)	1239	if (last_sent + send_interval <= NOW)
929	next = r->next;
930	}	1240	{
931
932	if (!send	1241	if (!send)
		1242	{
		1243	// generate a new packet, if wise
		1244
		1245	if (!established)
		1246	{
		1247	if (vpn->dns_sndpq.empty ())
		1248	{
		1249	send = new dns_snd (this);
		1250
		1251	cfg.reset (THISNODE->id);
		1252	send->gen_syn_req ();
		1253	}
		1254	}
933	&& vpn->dns_sndpq.size () < MAX_OUTSTANDING)	1255	else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING
934	{	1256	&& !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
		1257	{
		1258	//printf ("sending data request etc.\n"); //D
		1259	if (!snddq.empty ())
		1260	{
		1261	poll_interval = send_interval;
		1262	NEXT (NOW + send_interval);
		1263	}
		1264
935	send = new dns_req (this);	1265	send = new dns_snd (this);
936	send->gen_stream_req (sndseq, snddq);	1266	send->gen_stream_req (sndseq, snddq);
		1267	send->timeout = NOW + last_latency * 8.;
		1268
		1269	sndseq = (sndseq + 1) & SEQNO_MASK;
		1270	}
		1271
		1272	if (send)
937	vpn->dns_sndpq.push_back (send);	1273	vpn->dns_sndpq.push_back (send);
		1274	}
938		1275
939	sndseq = (sndseq + 1) & SEQNO_MASK;
940	}
941
942	tstamp min_next = NOW + (1. / (tstamp)MAX_RATE);
943
944	if (send)	1276	if (send)
945	{	1277	{
946	dns_packet *pkt = send->pkt;	1278	last_sent = NOW;
947		1279	sendto (vpn->dnsv4_fd,
948	next = min_next;	1280	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 ());	1281	vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
		1282	}
952	}	1283	}
953	else if (next < min_next)	1284	else
954	next = min_next;	1285	NEXT (last_sent + send_interval);
		1286
		1287	slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d)",
		1288	poll_interval, send_interval, next - NOW,
		1289	vpn->dns_sndpq.size (), snddq.size ());
		1290
		1291	// TODO: no idea when this happens, but when next < NOW, we have a problem
		1292	if (next < NOW + 0.0001)
		1293	next = NOW + 0.1;
955		1294
956	w.start (next);	1295	w.start (next);
957	}	1296	}
958		1297
959	#endif	1298	#endif

Diff Legend

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

Comparing gvpe/src/vpn_dns.C (file contents): Revision 1.9 by pcg, Fri Mar 4 04:52:38 2005 UTC vs. Revision 1.24 by pcg, Mon Mar 7 01:31:26 2005 UTC

Diff Legend

Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.9 by pcg, Fri Mar 4 04:52:38 2005 UTC vs.
Revision 1.24 by pcg, Mon Mar 7 01:31:26 2005 UTC