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

Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.15 by pcg, Fri Mar 4 10:15:45 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>
…		…
47		48
48	#define MIN_POLL_INTERVAL .02 // how often to poll minimally when the server has data	49	#define MIN_POLL_INTERVAL .02 // how often to poll minimally when the server has data
49	#define MAX_POLL_INTERVAL 6. // how often to poll minimally when the server has no data	50	#define MAX_POLL_INTERVAL 6. // how often to poll minimally when the server has no data
50	#define ACTIVITY_INTERVAL 5.	51	#define ACTIVITY_INTERVAL 5.
51		52
52	#define INITIAL_TIMEOUT 1. // retry timeouts	53	#define INITIAL_TIMEOUT 0.1 // retry timeouts
53	#define INITIAL_SYN_TIMEOUT 2. // retry timeout for initial syn	54	#define INITIAL_SYN_TIMEOUT 10. // retry timeout for initial syn
54		55
55	#define MIN_SEND_INTERVAL 0.01 // wait at least this time between sending requests	56	#define MIN_SEND_INTERVAL 0.01 // wait at least this time between sending requests
56	#define MAX_SEND_INTERVAL 0.5 // optimistic?	57	#define MAX_SEND_INTERVAL 0.5 // optimistic?
57		58
58	#define MAX_OUTSTANDING 40 // max. outstanding requests	59	#define MAX_OUTSTANDING 10 // max. outstanding requests
59	#define MAX_WINDOW 100 // max. for MAX_OUTSTANDING	60	#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog
60	#define MAX_BACKLOG (100*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE	61	#define MAX_BACKLOG (100*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE
61		62
62	#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
63	// 240 leaves about 4 bytes of server reply data	64	// 240 leaves about 4 bytes of server reply data
64	// every two request bytes less give room for one reply byte	65	// every two request bytes less give room for one reply byte
65		66
66	#define SEQNO_MASK 0xffff	67	#define SEQNO_MASK 0x3fff
67	#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )	68	#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )
68		69
69	#define MAX_LBL_SIZE 63	70	#define MAX_LBL_SIZE 63
70	#define MAX_PKT_SIZE 512	71	#define MAX_PKT_SIZE 512
71		72
…		…
264	static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO");	265	static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO");
265		266
266	/////////////////////////////////////////////////////////////////////////////	267	/////////////////////////////////////////////////////////////////////////////
267		268
268	#define HDRSIZE 6	269	#define HDRSIZE 6
269		270
270	inline void encode_header (char *data, int clientid, int seqno)	271	inline void encode_header (char *data, int clientid, int seqno, int retry = 0)
271	{	272	{
272	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	};
273		280
274	assert (clientid < 256);	281	assert (clientid < 256);
275		282
276	cdc26.encode (data, hdr, 3);	283	cdc26.encode (data, hdr, 3);
277	}	284	}
…		…
281	u8 hdr[3];	288	u8 hdr[3];
282		289
283	cdc26.decode (hdr, data, HDRSIZE);	290	cdc26.decode (hdr, data, HDRSIZE);
284		291
285	clientid = hdr[0];	292	clientid = hdr[0];
286	seqno = (hdr[1] << 8) \| hdr[2];	293	seqno = ((hdr[1] << 8) \| hdr[2]) & SEQNO_MASK;
287	}	294	}
288		295
289	/////////////////////////////////////////////////////////////////////////////	296	/////////////////////////////////////////////////////////////////////////////
290		297
291	struct byte_stream	298	struct byte_stream
…		…
320	}	327	}
321		328
322	void byte_stream::remove (int count)	329	void byte_stream::remove (int count)
323	{	330	{
324	if (count > fill)	331	if (count > fill)
325	abort ();	332	assert (count <= fill);
326		333
327	memmove (data, data + count, fill -= count);	334	memmove (data, data + count, fill -= count);
328	}	335	}
329		336
330	bool byte_stream::put (u8 *data, unsigned int datalen)	337	bool byte_stream::put (u8 *data, unsigned int datalen)
…		…
350	return true;	357	return true;
351	}	358	}
352		359
353	vpn_packet *byte_stream::get ()	360	vpn_packet *byte_stream::get ()
354	{	361	{
		362	unsigned int len;
		363
		364	for (;;)
		365	{
355	unsigned int len = (data [0] << 8) \| data [1];	366	len = (data [0] << 8) \| data [1];
356		367
357	if (len > MAXSIZE && fill >= 2)	368	if (len <= MAXSIZE \|\| fill < 2)
358	abort (); // TODO handle this gracefully, connection reset	369	break;
359		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
360	if (fill < len + 2)	376	if (fill < len + 2)
361	return 0;	377	return 0;
362		378
363	vpn_packet *pkt = new vpn_packet;	379	vpn_packet *pkt = new vpn_packet;
364		380
…		…
393	struct dns_cfg	409	struct dns_cfg
394	{	410	{
395	static int next_uid;	411	static int next_uid;
396		412
397	u8 id1, id2, id3, id4;	413	u8 id1, id2, id3, id4;
		414
398	u8 version;	415	u8 version;
		416	u8 flags;
399	u8 rrtype;	417	u8 rrtype;
400	u8 flags;
401	u8 def_ttl;	418	u8 def_ttl;
402	u8 rcv_cdc;	419
403	u8 snd_cdc;
404	u16 max_size;
405	u16 client;	420	u16 client;
406	u16 uid; // to make request unique	421	u16 uid; // to make request unique
407		422
408	u8 reserved[8];	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;
409		431
410	void reset (int clientid);	432	void reset (int clientid);
411	bool valid ();	433	bool valid ();
412	};	434	};
413		435
…		…
423	version = 1;	445	version = 1;
424		446
425	rrtype = RR_TYPE_TXT;	447	rrtype = RR_TYPE_TXT;
426	flags = 0;	448	flags = 0;
427	def_ttl = 0;	449	def_ttl = 0;
		450	seq_cdc = 26;
		451	req_cdc = 62;
428	rcv_cdc = 0;	452	rep_cdc = 0;
429	snd_cdc = 62;
430	max_size = ntohs (MAX_PKT_SIZE);	453	max_size = ntohs (MAX_PKT_SIZE);
431	client = ntohs (clientid);	454	client = ntohs (clientid);
432	uid = next_uid++;	455	uid = next_uid++;
433		456
434	memset (reserved, 0, 8);	457	r2 = r3 = r4 = 0;
		458	r4 = r5 = r6 = r7 = 0;
435	}	459	}
436		460
437	bool dns_cfg::valid ()	461	bool dns_cfg::valid ()
438	{	462	{
439	return id1 == 'G'	463	return id1 == 'G'
440	&& id2 == 'V'	464	&& id2 == 'V'
441	&& id3 == 'P'	465	&& id3 == 'P'
442	&& id4 == 'E'	466	&& id4 == 'E'
		467	&& seq_cdc == 26
		468	&& req_cdc == 62
		469	&& rep_cdc == 0
443	&& version == 1	470	&& version == 1
444	&& flags == 0
445	&& rcv_cdc == 0
446	&& snd_cdc == 62
447	&& max_size == ntohs (MAX_PKT_SIZE);	471	&& max_size == ntohs (MAX_PKT_SIZE);
448	}	472	}
449		473
450	struct dns_packet : net_packet	474	struct dns_packet : net_packet
451	{	475	{
452	u16 id;	476	u16 id;
453	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
454	u16 qdcount, ancount, nscount, arcount;	478	u16 qdcount, ancount, nscount, arcount;
455		479
456	u8 data[MAXSIZE - 6 * 2];	480	u8 data [MAXSIZE - 6 * 2];
457		481
458	int decode_label (char *data, int size, int &offs);	482	int decode_label (char *data, int size, int &offs);
459	};	483	};
460		484
461	int dns_packet::decode_label (char *data, int size, int &offs)	485	int dns_packet::decode_label (char *data, int size, int &offs)
…		…
492	return data - orig;	516	return data - orig;
493	}	517	}
494		518
495	/////////////////////////////////////////////////////////////////////////////	519	/////////////////////////////////////////////////////////////////////////////
496		520
497	struct dns_snd
498	{
499	dns_packet *pkt;
500	tstamp timeout, sent;
501	int retry;
502	struct dns_connection *dns;
503	int seqno;
504
505	void gen_stream_req (int seqno, byte_stream &stream);
506	void gen_syn_req (const dns_cfg &cfg);
507
508	dns_snd (dns_connection *dns);
509	~dns_snd ();
510	};
511
512	static u16 dns_id = 12098; // TODO: should be per-vpn	521	static u16 dns_id = 0; // TODO: should be per-vpn
513		522
514	static u16 next_id ()	523	static u16 next_id ()
515	{	524	{
		525	if (!dns_id)
		526	dns_id = time (0);
		527
516	// the simplest lsfr with periodicity 65535 i could find	528	// the simplest lsfr with periodicity 65535 i could find
517	dns_id = (dns_id << 1)	529	dns_id = (dns_id << 1)
518	\| (((dns_id >> 1)	530	\| (((dns_id >> 1)
519	^ (dns_id >> 2)	531	^ (dns_id >> 2)
520	^ (dns_id >> 4)	532	^ (dns_id >> 4)
521	^ (dns_id >> 15)) & 1);	533	^ (dns_id >> 15)) & 1);
522		534
523	return dns_id;	535	return dns_id;
524	}	536	}
525		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
526	dns_snd::dns_snd (dns_connection *dns)	583	dns_snd::dns_snd (dns_connection *dns)
527	: dns (dns)	584	: dns (dns)
528	{	585	{
529	timeout = 0;	586	timeout = 0;
530	retry = 0;	587	retry = 0;
531	seqno = 0;	588	seqno = 0;
532	sent = NOW;	589	sent = NOW;
		590	stdhdr = false;
533		591
534	pkt = new dns_packet;	592	pkt = new dns_packet;
535		593
536	pkt->id = next_id ();	594	pkt->id = next_id ();
537	}	595	}
…		…
564	}	622	}
565	}	623	}
566		624
567	void dns_snd::gen_stream_req (int seqno, byte_stream &stream)	625	void dns_snd::gen_stream_req (int seqno, byte_stream &stream)
568	{	626	{
		627	stdhdr = true;
569	this->seqno = seqno;	628	this->seqno = seqno;
570		629
571	timeout = NOW + INITIAL_TIMEOUT;	630	timeout = NOW + INITIAL_TIMEOUT;
572		631
573	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);	632	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
574	pkt->qdcount = htons (1);	633	pkt->qdcount = htons (1);
575		634
576	int offs = 6*2;	635	int offs = 6*2;
577	int dlen = MAX_DOMAIN_SIZE - (strlen (THISNODE->domain) + 2);	636	int dlen = MAX_DOMAIN_SIZE - (strlen (dns->c->conf->domain) + 2);
578	// 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,
579	// 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
580		639
581	char enc[256], *encp = enc;	640	char enc[256], *encp = enc;
582	encode_header (enc, THISNODE->id, seqno);	641	encode_header (enc, THISNODE->id, seqno);
…		…
600	encp += lbllen;	659	encp += lbllen;
601		660
602	enclen -= lbllen;	661	enclen -= lbllen;
603	}	662	}
604		663
605	append_domain (*pkt, offs, THISNODE->domain);	664	append_domain (*pkt, offs, dns->c->conf->domain);
606		665
607	(*pkt)[offs++] = 0;	666	(*pkt)[offs++] = 0;
608	(pkt)[offs++] = RR_TYPE_ANY >> 8; (pkt)[offs++] = RR_TYPE_ANY;	667	(pkt)[offs++] = RR_TYPE_ANY >> 8; (pkt)[offs++] = RR_TYPE_ANY;
609	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;	668	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;
610		669
611	pkt->len = offs;	670	pkt->len = offs;
612	}	671	}
613		672
614	void dns_snd::gen_syn_req (const dns_cfg &cfg)	673	void dns_snd::gen_syn_req ()
615	{	674	{
616	timeout = NOW + INITIAL_SYN_TIMEOUT;	675	timeout = NOW + INITIAL_SYN_TIMEOUT;
617		676
618	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);	677	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
619	pkt->qdcount = htons (1);	678	pkt->qdcount = htons (1);
620		679
621	int offs = 6*2;	680	int offs = 6 * 2;
622		681
623	int elen = cdc26.encode ((char )pkt->at (offs + 1), (u8 )&cfg, sizeof (dns_cfg));	682	int elen = cdc26.encode ((char )pkt->at (offs + 1), (u8 )&dns->cfg, sizeof (dns_cfg));
624		683
625	assert (elen <= MAX_LBL_SIZE);	684	assert (elen <= MAX_LBL_SIZE);
626		685
627	(*pkt)[offs] = elen;	686	(*pkt)[offs] = elen;
628	offs += elen + 1;	687	offs += elen + 1;
629	append_domain (*pkt, offs, THISNODE->domain);	688	append_domain (*pkt, offs, dns->c->conf->domain);
630		689
631	(*pkt)[offs++] = 0;	690	(*pkt)[offs++] = 0;
632	(pkt)[offs++] = RR_TYPE_A >> 8; (pkt)[offs++] = RR_TYPE_A;	691	(pkt)[offs++] = RR_TYPE_A >> 8; (pkt)[offs++] = RR_TYPE_A;
633	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;	692	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;
634		693
…		…
657	delete pkt;	716	delete pkt;
658	}	717	}
659		718
660	/////////////////////////////////////////////////////////////////////////////	719	/////////////////////////////////////////////////////////////////////////////
661		720
662	struct dns_connection
663	{
664	connection *c;
665	struct vpn *vpn;
666
667	dns_cfg cfg;
668
669	bool established;
670
671	tstamp last_received;
672	tstamp last_sent;
673	double poll_interval, send_interval;
674
675	vector<dns_rcv *> rcvpq;
676
677	byte_stream rcvdq; int rcvseq;
678	byte_stream snddq; int sndseq;
679
680	void time_cb (time_watcher &w); time_watcher tw;
681	void receive_rep (dns_rcv *r);
682
683	dns_connection (connection *c);
684	~dns_connection ();
685	};
686
687	dns_connection::dns_connection (connection *c)	721	dns_connection::dns_connection (connection *c)
688	: c (c)	722	: c (c)
689	, rcvdq (MAX_BACKLOG * 2)	723	, rcvdq (MAX_BACKLOG * 2)
690	, snddq (MAX_BACKLOG * 2)	724	, snddq (MAX_BACKLOG * 2)
691	, tw (this, &dns_connection::time_cb)	725	, tw (this, &dns_connection::time_cb)
…		…
696		730
697	rcvseq = sndseq = 0;	731	rcvseq = sndseq = 0;
698		732
699	last_sent = last_received = 0;	733	last_sent = last_received = 0;
700	poll_interval = MIN_POLL_INTERVAL;	734	poll_interval = MIN_POLL_INTERVAL;
701	send_interval = 0.2; // starting rate	735	send_interval = 0.5; // starting rate
		736	last_latency = INITIAL_TIMEOUT;
702	}	737	}
703		738
704	dns_connection::~dns_connection ()	739	dns_connection::~dns_connection ()
705	{	740	{
706	for (vector<dns_rcv *>::iterator i = rcvpq.begin ();	741	for (vector<dns_rcv *>::iterator i = rcvpq.begin ();
…		…
718		753
719	poll_interval = send_interval;	754	poll_interval = send_interval;
720	}	755	}
721	else	756	else
722	{	757	{
723	poll_interval *= 1.1;	758	poll_interval *= 1.5;
724	if (poll_interval > MAX_POLL_INTERVAL)	759	if (poll_interval > MAX_POLL_INTERVAL)
725	poll_interval = MAX_POLL_INTERVAL;	760	poll_interval = MAX_POLL_INTERVAL;
726	}	761	}
727		762
728	rcvpq.push_back (r);	763	rcvpq.push_back (r);
…		…
746	}	781	}
747		782
748	rcvseq = (rcvseq + 1) & SEQNO_MASK;	783	rcvseq = (rcvseq + 1) & SEQNO_MASK;
749		784
750	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)");
751	abort (); // MUST never overflow, can be caused by data corruption, TODO	788	abort (); // MUST never overflow, can be caused by data corruption, TODO
		789	}
752		790
753	while (vpn_packet *pkt = rcvdq.get ())	791	while (vpn_packet *pkt = rcvdq.get ())
754	{	792	{
755	sockinfo si;	793	sockinfo si;
756	si.host = 0; si.port = 0; si.prot = PROT_DNSv4;	794	si.host = 0x01010101; si.port = htons (c->conf->id); si.prot = PROT_DNSv4;
757		795
758	vpn->recv_vpn_packet (pkt, si);	796	vpn->recv_vpn_packet (pkt, si);
759		797
760	delete pkt;	798	delete pkt;
761	}	799	}
…		…
775	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);	813	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);
776		814
777	if (0 == (flags & (FLAG_RESPONSE \| FLAG_OP_MASK))	815	if (0 == (flags & (FLAG_RESPONSE \| FLAG_OP_MASK))
778	&& pkt.qdcount == htons (1))	816	&& pkt.qdcount == htons (1))
779	{	817	{
780	char qname[MAXSIZE];	818	char qname [MAXSIZE];
781	int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);	819	int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
782		820
783	u16 qtype = pkt [offs++] << 8; qtype \|= pkt [offs++];	821	u16 qtype = pkt [offs++] << 8; qtype \|= pkt [offs++];
784	u16 qclass = pkt [offs++] << 8; qclass \|= pkt [offs++];	822	u16 qclass = pkt [offs++] << 8; qclass \|= pkt [offs++];
785		823
786	pkt.qdcount = htons (1);	824	pkt.qdcount = htons (1);
787	pkt.ancount = 0;	825	pkt.ancount = 0;
788	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
789	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
790		828
791	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_NXDOMAIN);	829	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_SERVFAIL);
792		830
793	int dlen = strlen (THISNODE->domain);	831	int dlen = strlen (THISNODE->domain);
794		832
795	if (qclass == RR_CLASS_IN	833	if (qclass == RR_CLASS_IN
796	&& qlen > dlen + 1	834	&& qlen > dlen + 1
797	&& !memcmp (qname + qlen - dlen - 1, THISNODE->domain, dlen))	835	&& !memcmp (qname + qlen - (dlen + 1), THISNODE->domain, dlen))
798	{	836	{
799	// now generate reply	837	// now generate reply
800	pkt.ancount = htons (1); // one answer RR	838	pkt.ancount = htons (1); // one answer RR
801	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_OK);	839	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_OK);
802		840
…		…
815	if (0 < client && client <= conns.size ())	853	if (0 < client && client <= conns.size ())
816	{	854	{
817	connection *c = conns [client - 1];	855	connection *c = conns [client - 1];
818	dns_connection *dns = c->dns;	856	dns_connection *dns = c->dns;
819	dns_rcv *rcv;	857	dns_rcv *rcv;
		858	bool in_seq;
820		859
821	if (dns)	860	if (dns)
822	{	861	{
823	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 (); )
824	if (SEQNO_EQ ((*i)->seqno, seqno))	863	if (SEQNO_EQ ((*i)->seqno, seqno))
825	{	864	{
826	// already seen that request: simply reply with the cached reply	865	// already seen that request: simply reply with the cached reply
827	dns_rcv r = i;	866	dns_rcv r = i;
828		867
829	slog (L_DEBUG, "DUPLICATE %d\n", htons (r->pkt->id));	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;
830		873
831	memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len);	874	memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len);
832	pkt.id = r->pkt->id;	875
833	goto duplicate_request;	876	goto duplicate_request;
834	}	877	}
		878
		879	in_seq = dns->rcvseq == seqno;
835		880
836	// new packet, queue	881	// new packet, queue
837	rcv = new dns_rcv (seqno, data, datalen);	882	rcv = new dns_rcv (seqno, data, datalen);
838	dns->receive_rep (rcv);	883	dns->receive_rep (rcv);
839	}	884	}
840		885
		886	{
841	pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section	887	pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section
842		888
843	int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A;	889	int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A;
844	pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type	890	pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type
845	pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class	891	pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
846	pkt [offs++] = 0; pkt [offs++] = 0;	892	pkt [offs++] = 0; pkt [offs++] = 0;
847	pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL	893	pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL
848		894
849	int rdlen_offs = offs += 2;	895	int rdlen_offs = offs += 2;
850		896
851	int dlen = (dns ? ntohs (dns->cfg.max_size) : MAX_PKT_SIZE) - offs;	897	int dlen = (dns ? ntohs (dns->cfg.max_size) : MAX_PKT_SIZE) - offs;
852	// bind doesn't compress well, so reduce further by one label length	898	// bind doesn't compress well, so reduce further by one label length
853	dlen -= qlen;	899	dlen -= qlen;
854		900
855	if (dns)	901	if (dns)
856	{	902	{
		903	// only put data into in-order sequence packets, if
		904	// we receive out-of-order packets we generate empty
		905	// replies
857	while (dlen > 1 && !dns->snddq.empty ())	906	while (dlen > 1 && !dns->snddq.empty () && in_seq)
858	{	907	{
859	int txtlen = dlen <= 255 ? dlen - 1 : 255;	908	int txtlen = dlen <= 255 ? dlen - 1 : 255;
860		909
861	if (txtlen > dns->snddq.size ())	910	if (txtlen > dns->snddq.size ())
862	txtlen = dns->snddq.size ();	911	txtlen = dns->snddq.size ();
863		912
864	pkt[offs++] = txtlen;	913	pkt[offs++] = txtlen;
865	memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);	914	memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
866	offs += txtlen;	915	offs += txtlen;
867	dns->snddq.remove (txtlen);	916	dns->snddq.remove (txtlen);
868		917
869	dlen -= txtlen + 1;	918	dlen -= txtlen + 1;
870	}	919	}
871		920
872	// avoid empty TXT rdata	921	// avoid empty TXT rdata
873	if (offs == rdlen_offs)	922	if (offs == rdlen_offs)
874	pkt[offs++] = 0;	923	pkt[offs++] = 0;
875		924
876	slog (L_NOISE, "snddq %d", dns->snddq.size ());	925	slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
877	}	926	}
878	else	927	else
879	{	928	{
880	// send RST	929	// send RST
881	pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;	930	pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
882	pkt [offs++] = CMD_IP_RST;	931	pkt [offs++] = CMD_IP_RST;
883	}	932	}
884		933
885	int rdlen = offs - rdlen_offs;	934	int rdlen = offs - rdlen_offs;
886		935
887	pkt [rdlen_offs - 2] = rdlen >> 8;	936	pkt [rdlen_offs - 2] = rdlen >> 8;
888	pkt [rdlen_offs - 1] = rdlen;	937	pkt [rdlen_offs - 1] = rdlen;
889		938
890	if (dns)	939	if (dns)
891	{	940	{
892	// now update dns_rcv copy	941	// now update dns_rcv copy
893	rcv->pkt->len = offs;	942	rcv->pkt->len = offs;
894	memcpy (rcv->pkt->at (0), pkt.at (0), offs);	943	memcpy (rcv->pkt->at (0), pkt.at (0), offs);
895	}	944	}
		945	}
896		946
897	duplicate_request: ;	947	duplicate_request: ;
898	}	948	}
899	else	949	else
900	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);	950	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);
…		…
912	pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class	962	pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
913	pkt [offs++] = 0; pkt [offs++] = 0;	963	pkt [offs++] = 0; pkt [offs++] = 0;
914	pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL	964	pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL
915	pkt [offs++] = 0; pkt [offs++] = 4; // rdlength	965	pkt [offs++] = 0; pkt [offs++] = 4; // rdlength
916		966
917	slog (L_INFO, _("DNS tunnel: client %d tries to connect"), client);	967	slog (L_INFO, _("DNS: client %d connects"), client);
918		968
919	pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;	969	pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
920	pkt [offs++] = CMD_IP_REJ;	970	pkt [offs++] = CMD_IP_REJ;
921		971
922	if (0 < client && client <= conns.size ())	972	if (0 < client && client <= conns.size ())
…		…
959	int seqno = (*i)->seqno;	1009	int seqno = (*i)->seqno;
960	u8 data[MAXSIZE], *datap = data;	1010	u8 data[MAXSIZE], *datap = data;
961		1011
962	if ((*i)->retry)	1012	if ((*i)->retry)
963	{	1013	{
964	dns->send_interval *= 1.001;	1014	dns->send_interval *= 1.01;
965	if (dns->send_interval > MAX_SEND_INTERVAL)	1015	if (dns->send_interval > MAX_SEND_INTERVAL)
966	dns->send_interval = MAX_SEND_INTERVAL;	1016	dns->send_interval = MAX_SEND_INTERVAL;
967	}	1017	}
968	else	1018	else
969	{	1019	{
970	#if 1	1020	#if 1
971	dns->send_interval *= 0.9999;	1021	dns->send_interval *= 0.999;
972	#endif	1022	#endif
973	if (dns->send_interval < MIN_SEND_INTERVAL)	1023	if (dns->send_interval < MIN_SEND_INTERVAL)
974	dns->send_interval = MIN_SEND_INTERVAL;	1024	dns->send_interval = MIN_SEND_INTERVAL;
975		1025
976	// the latency surely puts an upper bound on	1026	// the latency surely puts an upper bound on
977	// the minimum send interval	1027	// the minimum send interval
978	double latency = NOW - (*i)->sent;	1028	double latency = NOW - (*i)->sent;
		1029	dns->last_latency = latency;
979		1030
980	if (dns->send_interval > latency)	1031	if (dns->send_interval > latency)
981	dns->send_interval = latency;	1032	dns->send_interval = latency;
982	}	1033	}
983		1034
…		…
1036		1087
1037	if (ip [0] == CMD_IP_1	1088	if (ip [0] == CMD_IP_1
1038	&& ip [1] == CMD_IP_2	1089	&& ip [1] == CMD_IP_2
1039	&& ip [2] == CMD_IP_3)	1090	&& ip [2] == CMD_IP_3)
1040	{	1091	{
1041	slog (L_TRACE, _("got tunnel meta command %02x"), ip [3]);	1092	slog (L_TRACE, _("DNS: got tunnel meta command %02x"), ip [3]);
1042		1093
1043	if (ip [3] == CMD_IP_RST)	1094	if (ip [3] == CMD_IP_RST)
1044	{	1095	{
1045	slog (L_DEBUG, _("got tunnel RST request"));	1096	slog (L_DEBUG, _("DNS: got tunnel RST request"));
1046		1097
1047	delete dns; c->dns = 0;	1098	delete dns; c->dns = 0;
1048		1099
1049	return;	1100	return;
1050	}	1101	}
1051	else if (ip [3] == CMD_IP_SYN)	1102	else if (ip [3] == CMD_IP_SYN)
1052	{	1103	{
1053	slog (L_DEBUG, _("got tunnel SYN reply, server likes us."));	1104	slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us."));
1054	dns->established = true;	1105	dns->established = true;
1055	}	1106	}
1056	else if (ip [3] == CMD_IP_REJ)	1107	else if (ip [3] == CMD_IP_REJ)
1057	{	1108	{
1058	slog (L_DEBUG, _("got tunnel REJ reply, server does not like us, aborting."));	1109	slog (L_DEBUG, _("DNS: got tunnel REJ reply, server does not like us, aborting."));
1059	abort ();	1110	abort ();
1060	}	1111	}
1061	else	1112	else
1062	slog (L_INFO, _("got unknown meta command %02x"), ip [3]);	1113	slog (L_INFO, _("DNS: got unknown meta command %02x"), ip [3]);
1063	}	1114	}
1064	else	1115	else
1065	slog (L_INFO, _("got spurious a record %d.%d.%d.%d"),	1116	slog (L_INFO, _("DNS: got spurious a record %d.%d.%d.%d"),
1066	ip [0], ip [1], ip [2], ip [3]);	1117	ip [0], ip [1], ip [2], ip [3]);
1067		1118
1068	return;	1119	return;
1069	}	1120	}
1070		1121
1071	int client, rseqno;	1122	int client, rseqno;
1072	decode_header (qname, client, rseqno);	1123	decode_header (qname, client, rseqno);
1073		1124
1074	if (client != THISNODE->id)	1125	if (client != THISNODE->id)
1075	{	1126	{
1076	slog (L_INFO, _("got dns tunnel response with wrong clientid, ignoring"));	1127	slog (L_INFO, _("DNS: got dns tunnel response with wrong clientid, ignoring"));
1077	datap = 0;	1128	datap = 0;
1078	}	1129	}
1079	else if (rseqno != seqno)	1130	else if (rseqno != seqno)
1080	{	1131	{
1081	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?"));
1082	datap = 0;	1133	datap = 0;
1083	}	1134	}
1084	}	1135	}
1085	}	1136	}
1086		1137
…		…
1103		1154
1104	pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len);	1155	pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len);
1105		1156
1106	if (pkt->len > 0)	1157	if (pkt->len > 0)
1107	{	1158	{
1108	if (THISNODE->dns_port)	1159	if (ntohs (pkt->flags) & FLAG_RESPONSE)
		1160	dnsv4_client (*pkt);
		1161	else
1109	{	1162	{
1110	dnsv4_server (*pkt);	1163	dnsv4_server (*pkt);
1111	sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len);	1164	sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len);
1112	}	1165	}
1113	else
1114	dnsv4_client (*pkt);
1115		1166
1116	delete pkt;	1167	delete pkt;
1117	}	1168	}
1118	}	1169	}
1119	}	1170	}
1120		1171
1121	bool	1172	bool
1122	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)
1123	{	1174	{
		1175	int client = ntohs (si.port);
		1176
		1177	assert (0 < client && client <= conns.size ());
		1178
		1179	connection *c = conns [client - 1];
		1180
1124	if (!dns)	1181	if (!c->dns)
1125	dns = new dns_connection (this);	1182	c->dns = new dns_connection (c);
1126		1183
1127	if (!dns->snddq.put (pkt))	1184	if (!c->dns->snddq.put (pkt))
1128	return false;	1185	return false;
1129		1186
1130	dns->tw.trigger ();	1187	c->dns->tw.trigger ();
1131		1188
1132	return true;	1189	return true;
1133	}	1190	}
1134		1191
1135	void	1192	void
…		…
1162	if (!send)	1219	if (!send)
1163	{	1220	{
1164	send = r;	1221	send = r;
1165		1222
1166	r->retry++;	1223	r->retry++;
1167	r->timeout = 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	}
1168	}	1233	}
1169	}	1234	}
1170	else	1235	else
1171	NEXT (r->timeout);	1236	NEXT (r->timeout);
1172	}	1237	}
…		…
1182	if (vpn->dns_sndpq.empty ())	1247	if (vpn->dns_sndpq.empty ())
1183	{	1248	{
1184	send = new dns_snd (this);	1249	send = new dns_snd (this);
1185		1250
1186	cfg.reset (THISNODE->id);	1251	cfg.reset (THISNODE->id);
1187	send->gen_syn_req (cfg);	1252	send->gen_syn_req ();
1188	}	1253	}
1189	}	1254	}
1190	else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING)	1255	else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING
		1256	&& !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
1191	{	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
1192	send = new dns_snd (this);	1265	send = new dns_snd (this);
1193	send->gen_stream_req (sndseq, snddq);	1266	send->gen_stream_req (sndseq, snddq);
		1267	send->timeout = NOW + last_latency * 8.;
1194		1268
1195	sndseq = (sndseq + 1) & SEQNO_MASK;	1269	sndseq = (sndseq + 1) & SEQNO_MASK;
1196	}	1270	}
1197		1271
1198	if (send)	1272	if (send)
…		…
1208	}	1282	}
1209	}	1283	}
1210	else	1284	else
1211	NEXT (last_sent + send_interval);	1285	NEXT (last_sent + send_interval);
1212		1286
1213	slog (L_NOISE, "pi %f si %f N %f (%d:%d)",	1287	slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d)",
1214	poll_interval, send_interval, next - NOW,	1288	poll_interval, send_interval, next - NOW,
1215	vpn->dns_sndpq.size (), snddq.size ());	1289	vpn->dns_sndpq.size (), snddq.size ());
1216		1290
1217	// TODO: no idea when this happens, but when next < NOW, we have a problem	1291	// TODO: no idea when this happens, but when next < NOW, we have a problem
1218	if (next < NOW + 0.0001)	1292	if (next < NOW + 0.0001)

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Comparing gvpe/src/vpn_dns.C (file contents): Revision 1.15 by pcg, Fri Mar 4 10:15:45 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 1.15 by pcg, Fri Mar 4 10:15:45 2005 UTC vs.
Revision 1.24 by pcg, Mon Mar 7 01:31:26 2005 UTC