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

Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.17 by pcg, Sat Mar 5 03:47:05 2005 UTC vs.
Revision 1.36 by pcg, Thu Mar 17 22:24:31 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_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	49	#define MAX_POLL_INTERVAL 5. // how often to poll minimally when the server has no data
50	#define ACTIVITY_INTERVAL 5.	50	#define ACTIVITY_INTERVAL 5.
51		51
		52	#define TIMEOUT_FACTOR 8.
		53
52	#define INITIAL_TIMEOUT 0.1 // retry timeouts	54	#define INITIAL_TIMEOUT 0.1 // retry timeouts
53	#define INITIAL_SYN_TIMEOUT 10. // retry timeout for initial syn	55	#define INITIAL_SYN_TIMEOUT 2. // retry timeout for initial syn
54		56
55	#define MIN_SEND_INTERVAL 0.01 // wait at least this time between sending requests	57	#define MIN_SEND_INTERVAL 0.001 // wait at least this time between sending requests
56	#define MAX_SEND_INTERVAL 0.5 // optimistic?	58	#define MAX_SEND_INTERVAL 2. // optimistic?
57		59
		60	#define LATENCY_FACTOR 0.5 // RTT * LATENCY_FACTOR == sending rate
58	#define MAX_OUTSTANDING 10 // max. outstanding requests	61	#define MAX_OUTSTANDING 100 // max. outstanding requests
59	#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog	62	#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	63	#define MAX_BACKLOG (64*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE
61		64
62	#define MAX_DOMAIN_SIZE 220 // 255 is legal limit, but bind doesn't compress well	65	#define MAX_DOMAIN_SIZE 240 // 255 is legal limit, but bind doesn't compress well
63	// 240 leaves about 4 bytes of server reply data	66	// 240 leaves about 4 bytes of server reply data
64	// every two request bytes less give room for one reply byte	67	// every request byte less give room for two reply bytes
65		68
66	#define SEQNO_MASK 0x3fff	69	#define SEQNO_MASK 0x3fff
67	#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )	70	#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )
68		71
69	#define MAX_LBL_SIZE 63	72	#define MAX_LBL_SIZE 63
…		…
264	static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO");	267	static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO");
265		268
266	/////////////////////////////////////////////////////////////////////////////	269	/////////////////////////////////////////////////////////////////////////////
267		270
268	#define HDRSIZE 6	271	#define HDRSIZE 6
269		272
270	inline void encode_header (char *data, int clientid, int seqno, int retry = 0)	273	inline void encode_header (char *data, int clientid, int seqno, int retry = 0)
271	{	274	{
272	seqno &= SEQNO_MASK;	275	seqno &= SEQNO_MASK;
273		276
274	u8 hdr[3] = {	277	u8 hdr[3] = {
…		…
356	return true;	359	return true;
357	}	360	}
358		361
359	vpn_packet *byte_stream::get ()	362	vpn_packet *byte_stream::get ()
360	{	363	{
		364	unsigned int len;
		365
		366	for (;;)
		367	{
361	unsigned int len = (data [0] << 8) \| data [1];	368	len = (data [0] << 8) \| data [1];
362		369
363	if (len > MAXSIZE && fill >= 2)	370	if (len <= MAXSIZE \|\| fill < 2)
364	assert (len <= MAXSIZE \|\| fill < 2); // TODO handle this gracefully, connection reset	371	break;
365		372
		373	// TODO: handle this better than skipping, e.g. by reset
		374	slog (L_DEBUG, _("DNS: corrupted packet stream skipping a byte..."));
		375	remove (1);
		376	}
		377
366	if (fill < len + 2)	378	if (fill < len + 2)
367	return 0;	379	return 0;
368		380
369	vpn_packet *pkt = new vpn_packet;	381	vpn_packet *pkt = new vpn_packet;
370		382
…		…
399	struct dns_cfg	411	struct dns_cfg
400	{	412	{
401	static int next_uid;	413	static int next_uid;
402		414
403	u8 id1, id2, id3, id4;	415	u8 id1, id2, id3, id4;
		416
404	u8 version;	417	u8 version;
		418	u8 flags;
405	u8 rrtype;	419	u8 rrtype;
406	u8 flags;
407	u8 def_ttl;	420	u8 def_ttl;
408	u8 rcv_cdc;	421
409	u8 snd_cdc;
410	u16 max_size;
411	u16 client;	422	u16 client;
412	u16 uid; // to make request unique	423	u16 uid; // to make request unique
413		424
414	u8 reserved[8];	425	u16 max_size;
		426	u8 seq_cdc;
		427	u8 req_cdc;
		428
		429	u8 rep_cdc;
		430	u8 delay; // time in 0.01s units that the server may delay replying packets
		431	u8 r3, r4;
		432
		433	u8 r5, r6, r7, r8;
415		434
416	void reset (int clientid);	435	void reset (int clientid);
417	bool valid ();	436	bool valid ();
418	};	437	};
419		438
…		…
428		447
429	version = 1;	448	version = 1;
430		449
431	rrtype = RR_TYPE_TXT;	450	rrtype = RR_TYPE_TXT;
432	flags = 0;	451	flags = 0;
433	def_ttl = 1;	452	def_ttl = 0;
		453	seq_cdc = 26;
		454	req_cdc = 62;
434	rcv_cdc = 0;	455	rep_cdc = 0;
435	snd_cdc = 62;
436	max_size = ntohs (MAX_PKT_SIZE);	456	max_size = htons (MAX_PKT_SIZE);
437	client = ntohs (clientid);	457	client = htons (clientid);
438	uid = next_uid++;	458	uid = next_uid++;
		459	delay = 0;
439		460
440	memset (reserved, 0, 8);	461	r3 = r4 = 0;
		462	r4 = r5 = r6 = r7 = 0;
441	}	463	}
442		464
443	bool dns_cfg::valid ()	465	bool dns_cfg::valid ()
444	{	466	{
445	return id1 == 'G'	467	return id1 == 'G'
446	&& id2 == 'V'	468	&& id2 == 'V'
447	&& id3 == 'P'	469	&& id3 == 'P'
448	&& id4 == 'E'	470	&& id4 == 'E'
		471	&& seq_cdc == 26
		472	&& req_cdc == 62
		473	&& rep_cdc == 0
449	&& version == 1	474	&& version == 1;
450	&& flags == 0
451	&& rcv_cdc == 0
452	&& snd_cdc == 62
453	&& max_size == ntohs (MAX_PKT_SIZE);
454	}	475	}
455		476
456	struct dns_packet : net_packet	477	struct dns_packet : net_packet
457	{	478	{
458	u16 id;	479	u16 id;
459	u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4	480	u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4
460	u16 qdcount, ancount, nscount, arcount;	481	u16 qdcount, ancount, nscount, arcount;
461		482
462	u8 data[MAXSIZE - 6 * 2];	483	u8 data [MAXSIZE - 6 * 2];
463		484
464	int decode_label (char *data, int size, int &offs);	485	int decode_label (char *data, int size, int &offs);
465	};	486	};
466		487
467	int dns_packet::decode_label (char *data, int size, int &offs)	488	int dns_packet::decode_label (char *data, int size, int &offs)
…		…
498	return data - orig;	519	return data - orig;
499	}	520	}
500		521
501	/////////////////////////////////////////////////////////////////////////////	522	/////////////////////////////////////////////////////////////////////////////
502		523
		524	static u16 dns_id = 0; // TODO: should be per-vpn
		525
		526	static u16 next_id ()
		527	{
		528	if (!dns_id)
		529	dns_id = time (0);
		530
		531	// the simplest lsfr with periodicity 65535 i could find
		532	dns_id = (dns_id << 1)
		533	\| (((dns_id >> 1)
		534	^ (dns_id >> 2)
		535	^ (dns_id >> 4)
		536	^ (dns_id >> 15)) & 1);
		537
		538	return dns_id;
		539	}
		540
		541	struct dns_rcv;
		542	struct dns_snd;
		543
		544	struct dns_connection
		545	{
		546	connection *c;
		547	struct vpn *vpn;
		548
		549	dns_cfg cfg;
		550
		551	bool established;
		552
		553	tstamp last_received;
		554	tstamp last_sent;
		555	double min_latency;
		556	double poll_interval, send_interval;
		557
		558	vector<dns_rcv *> rcvpq;
		559
		560	byte_stream rcvdq; int rcvseq; int repseq;
		561	byte_stream snddq; int sndseq;
		562
		563	void time_cb (time_watcher &w); time_watcher tw;
		564	void receive_rep (dns_rcv *r);
		565
		566	dns_connection (connection *c);
		567	~dns_connection ();
		568	};
		569
503	struct dns_snd	570	struct dns_snd
504	{	571	{
505	dns_packet *pkt;	572	dns_packet *pkt;
506	tstamp timeout, sent;	573	tstamp timeout, sent;
507	int retry;	574	int retry;
508	struct dns_connection *dns;	575	struct dns_connection *dns;
509	int seqno;	576	int seqno;
510	bool stdhdr;	577	bool stdhdr;
511		578
512	void gen_stream_req (int seqno, byte_stream &stream);	579	void gen_stream_req (int seqno, byte_stream &stream);
513	void gen_syn_req (const dns_cfg &cfg);	580	void gen_syn_req ();
514		581
515	dns_snd (dns_connection *dns);	582	dns_snd (dns_connection *dns);
516	~dns_snd ();	583	~dns_snd ();
517	};	584	};
518
519	static u16 dns_id = 12098; // TODO: should be per-vpn
520
521	static u16 next_id ()
522	{
523	// the simplest lsfr with periodicity 65535 i could find
524	dns_id = (dns_id << 1)
525	\| (((dns_id >> 1)
526	^ (dns_id >> 2)
527	^ (dns_id >> 4)
528	^ (dns_id >> 15)) & 1);
529
530	return dns_id;
531	}
532		585
533	dns_snd::dns_snd (dns_connection *dns)	586	dns_snd::dns_snd (dns_connection *dns)
534	: dns (dns)	587	: dns (dns)
535	{	588	{
536	timeout = 0;	589	timeout = 0;
…		…
581		634
582	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);	635	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
583	pkt->qdcount = htons (1);	636	pkt->qdcount = htons (1);
584		637
585	int offs = 6*2;	638	int offs = 6*2;
586	int dlen = MAX_DOMAIN_SIZE - (strlen (THISNODE->domain) + 2);	639	int dlen = MAX_DOMAIN_SIZE - (strlen (dns->c->conf->domain) + 2);
587	// MAX_DOMAIN_SIZE is technically 255, but bind doesn't compress responses well,	640	// MAX_DOMAIN_SIZE is technically 255, but bind doesn't compress responses well,
588	// so we need to have space for 2*MAX_DOMAIN_SIZE + header + extra	641	// so we need to have space for 2*MAX_DOMAIN_SIZE + header + extra
589		642
590	char enc[256], *encp = enc;	643	char enc[256], *encp = enc;
591	encode_header (enc, THISNODE->id, seqno);	644	encode_header (enc, THISNODE->id, seqno);
…		…
609	encp += lbllen;	662	encp += lbllen;
610		663
611	enclen -= lbllen;	664	enclen -= lbllen;
612	}	665	}
613		666
614	append_domain (*pkt, offs, THISNODE->domain);	667	append_domain (*pkt, offs, dns->c->conf->domain);
615		668
616	(*pkt)[offs++] = 0;	669	(*pkt)[offs++] = 0;
617	(pkt)[offs++] = RR_TYPE_ANY >> 8; (pkt)[offs++] = RR_TYPE_ANY;	670	(pkt)[offs++] = RR_TYPE_ANY >> 8; (pkt)[offs++] = RR_TYPE_ANY;
618	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;	671	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;
619		672
620	pkt->len = offs;	673	pkt->len = offs;
621	}	674	}
622		675
623	void dns_snd::gen_syn_req (const dns_cfg &cfg)	676	void dns_snd::gen_syn_req ()
624	{	677	{
625	timeout = NOW + INITIAL_SYN_TIMEOUT;	678	timeout = NOW + INITIAL_SYN_TIMEOUT;
626		679
627	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);	680	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
628	pkt->qdcount = htons (1);	681	pkt->qdcount = htons (1);
629		682
630	int offs = 6*2;	683	int offs = 6 * 2;
631		684
632	int elen = cdc26.encode ((char )pkt->at (offs + 1), (u8 )&cfg, sizeof (dns_cfg));	685	int elen = cdc26.encode ((char )pkt->at (offs + 1), (u8 )&dns->cfg, sizeof (dns_cfg));
633		686
634	assert (elen <= MAX_LBL_SIZE);	687	assert (elen <= MAX_LBL_SIZE);
635		688
636	(*pkt)[offs] = elen;	689	(*pkt)[offs] = elen;
637	offs += elen + 1;	690	offs += elen + 1;
638	append_domain (*pkt, offs, THISNODE->domain);	691	append_domain (*pkt, offs, dns->c->conf->domain);
639		692
640	(*pkt)[offs++] = 0;	693	(*pkt)[offs++] = 0;
641	(pkt)[offs++] = RR_TYPE_A >> 8; (pkt)[offs++] = RR_TYPE_A;	694	(pkt)[offs++] = RR_TYPE_A >> 8; (pkt)[offs++] = RR_TYPE_A;
642	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;	695	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;
643		696
…		…
666	delete pkt;	719	delete pkt;
667	}	720	}
668		721
669	/////////////////////////////////////////////////////////////////////////////	722	/////////////////////////////////////////////////////////////////////////////
670		723
671	struct dns_connection
672	{
673	connection *c;
674	struct vpn *vpn;
675
676	dns_cfg cfg;
677
678	bool established;
679
680	tstamp last_received;
681	tstamp last_sent;
682	double last_latency;
683	double poll_interval, send_interval;
684
685	vector<dns_rcv *> rcvpq;
686
687	byte_stream rcvdq; int rcvseq;
688	byte_stream snddq; int sndseq;
689
690	void time_cb (time_watcher &w); time_watcher tw;
691	void receive_rep (dns_rcv *r);
692
693	dns_connection (connection *c);
694	~dns_connection ();
695	};
696
697	dns_connection::dns_connection (connection *c)	724	dns_connection::dns_connection (connection *c)
698	: c (c)	725	: c (c)
699	, rcvdq (MAX_BACKLOG * 2)	726	, rcvdq (MAX_BACKLOG * 2)
700	, snddq (MAX_BACKLOG * 2)	727	, snddq (MAX_BACKLOG)
701	, tw (this, &dns_connection::time_cb)	728	, tw (this, &dns_connection::time_cb)
702	{	729	{
703	vpn = c->vpn;	730	vpn = c->vpn;
704		731
705	established = false;	732	established = false;
706		733
707	rcvseq = sndseq = 0;	734	rcvseq = repseq = sndseq = 0;
708		735
709	last_sent = last_received = 0;	736	last_sent = last_received = 0;
710	poll_interval = MIN_POLL_INTERVAL;	737	poll_interval = 0.5; // starting here
711	send_interval = 0.5; // starting rate	738	send_interval = 0.5; // starting rate
712	last_latency = INITIAL_TIMEOUT;	739	min_latency = INITIAL_TIMEOUT;
713	}	740	}
714		741
715	dns_connection::~dns_connection ()	742	dns_connection::~dns_connection ()
716	{	743	{
717	for (vector<dns_rcv *>::iterator i = rcvpq.begin ();	744	for (vector<dns_rcv *>::iterator i = rcvpq.begin ();
…		…
730	poll_interval = send_interval;	757	poll_interval = send_interval;
731	}	758	}
732	else	759	else
733	{	760	{
734	poll_interval *= 1.5;	761	poll_interval *= 1.5;
		762
735	if (poll_interval > MAX_POLL_INTERVAL)	763	if (poll_interval > MAX_POLL_INTERVAL)
736	poll_interval = MAX_POLL_INTERVAL;	764	poll_interval = MAX_POLL_INTERVAL;
737	}	765	}
738		766
739	rcvpq.push_back (r);	767	rcvpq.push_back (r);
…		…
765	}	793	}
766		794
767	while (vpn_packet *pkt = rcvdq.get ())	795	while (vpn_packet *pkt = rcvdq.get ())
768	{	796	{
769	sockinfo si;	797	sockinfo si;
770	si.host = 0; si.port = 0; si.prot = PROT_DNSv4;	798	si.host = htonl (c->conf->id); si.port = 0; si.prot = PROT_DNSv4;
771		799
772	vpn->recv_vpn_packet (pkt, si);	800	vpn->recv_vpn_packet (pkt, si);
773		801
774	delete pkt;	802	delete pkt;
775	}	803	}
…		…
789	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);	817	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);
790		818
791	if (0 == (flags & (FLAG_RESPONSE \| FLAG_OP_MASK))	819	if (0 == (flags & (FLAG_RESPONSE \| FLAG_OP_MASK))
792	&& pkt.qdcount == htons (1))	820	&& pkt.qdcount == htons (1))
793	{	821	{
794	char qname[MAXSIZE];	822	char qname [MAXSIZE];
795	int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);	823	int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
796		824
797	u16 qtype = pkt [offs++] << 8; qtype \|= pkt [offs++];	825	u16 qtype = pkt [offs++] << 8; qtype \|= pkt [offs++];
798	u16 qclass = pkt [offs++] << 8; qclass \|= pkt [offs++];	826	u16 qclass = pkt [offs++] << 8; qclass \|= pkt [offs++];
799		827
…		…
806		834
807	int dlen = strlen (THISNODE->domain);	835	int dlen = strlen (THISNODE->domain);
808		836
809	if (qclass == RR_CLASS_IN	837	if (qclass == RR_CLASS_IN
810	&& qlen > dlen + 1	838	&& qlen > dlen + 1
811	&& !memcmp (qname + qlen - dlen - 1, THISNODE->domain, dlen))	839	&& !memcmp (qname + qlen - (dlen + 1), THISNODE->domain, dlen))
812	{	840	{
813	// now generate reply	841	// now generate reply
814	pkt.ancount = htons (1); // one answer RR	842	pkt.ancount = htons (1); // one answer RR
815	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_OK);	843	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_OK);
816		844
…		…
829	if (0 < client && client <= conns.size ())	857	if (0 < client && client <= conns.size ())
830	{	858	{
831	connection *c = conns [client - 1];	859	connection *c = conns [client - 1];
832	dns_connection *dns = c->dns;	860	dns_connection *dns = c->dns;
833	dns_rcv *rcv;	861	dns_rcv *rcv;
834	bool in_seq;
835		862
836	if (dns)	863	if (dns)
837	{	864	{
838	for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); )	865	for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); )
839	if (SEQNO_EQ ((*i)->seqno, seqno))	866	if (SEQNO_EQ ((*i)->seqno, seqno))
…		…
850	memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len);	877	memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len);
851		878
852	goto duplicate_request;	879	goto duplicate_request;
853	}	880	}
854		881
855	in_seq = dns->rcvseq == seqno;
856
857	// new packet, queue	882	// new packet, queue
858	rcv = new dns_rcv (seqno, data, datalen);	883	rcv = new dns_rcv (seqno, data, datalen);
859	dns->receive_rep (rcv);	884	dns->receive_rep (rcv);
860	}	885	}
861		886
		887	{
862	pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section	888	pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section
863		889
864	int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A;	890	int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A;
865	pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type	891	pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type
866	pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class	892	pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
867	pkt [offs++] = 0; pkt [offs++] = 0;	893	pkt [offs++] = 0; pkt [offs++] = 0;
868	pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL	894	pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL
869		895
870	int rdlen_offs = offs += 2;	896	int rdlen_offs = offs += 2;
871		897
		898	if (dns)
		899	{
872	int dlen = (dns ? ntohs (dns->cfg.max_size) : MAX_PKT_SIZE) - offs;	900	int dlen = ntohs (dns->cfg.max_size) - offs;
		901
873	// bind doesn't compress well, so reduce further by one label length	902	// bind doesn't compress well, so reduce further by one label length
874	dlen -= qlen;	903	dlen -= qlen;
875		904
876	if (dns)
877	{
878	// only put data into in-order sequence packets, if	905	// only put data into in-order sequence packets, if
879	// we receive out-of-order packets we generate empty	906	// we receive out-of-order packets we generate empty
880	// replies	907	// replies
881	while (dlen > 1 && !dns->snddq.empty () && in_seq)	908	//printf ("%d - %d & %x (=%d) < %d\n", seqno, dns->repseq, SEQNO_MASK, (seqno - dns->repseq) & SEQNO_MASK, MAX_WINDOW);//D
		909	if (((seqno - dns->repseq) & SEQNO_MASK) <= MAX_WINDOW)
882	{	910	{
		911	dns->repseq = seqno;
		912
		913	while (dlen > 1 && !dns->snddq.empty ())
		914	{
883	int txtlen = dlen <= 255 ? dlen - 1 : 255;	915	int txtlen = dlen <= 255 ? dlen - 1 : 255;
884		916
885	if (txtlen > dns->snddq.size ())	917	if (txtlen > dns->snddq.size ())
886	txtlen = dns->snddq.size ();	918	txtlen = dns->snddq.size ();
887		919
888	pkt[offs++] = txtlen;	920	pkt[offs++] = txtlen;
889	memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);	921	memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
890	offs += txtlen;	922	offs += txtlen;
891	dns->snddq.remove (txtlen);	923	dns->snddq.remove (txtlen);
892		924
893	dlen -= txtlen + 1;	925	dlen -= txtlen + 1;
		926	}
894	}	927	}
895		928
896	// avoid empty TXT rdata	929	// avoid completely empty TXT rdata
897	if (offs == rdlen_offs)	930	if (offs == rdlen_offs)
898	pkt[offs++] = 0;	931	pkt[offs++] = 0;
899		932
900	slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());	933	slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
901	}	934	}
902	else	935	else
903	{	936	{
904	// send RST	937	// send RST
905	pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;	938	pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
906	pkt [offs++] = CMD_IP_RST;	939	pkt [offs++] = CMD_IP_RST;
907	}	940	}
908		941
909	int rdlen = offs - rdlen_offs;	942	int rdlen = offs - rdlen_offs;
910		943
911	pkt [rdlen_offs - 2] = rdlen >> 8;	944	pkt [rdlen_offs - 2] = rdlen >> 8;
912	pkt [rdlen_offs - 1] = rdlen;	945	pkt [rdlen_offs - 1] = rdlen;
913		946
914	if (dns)	947	if (dns)
915	{	948	{
916	// now update dns_rcv copy	949	// now update dns_rcv copy
917	rcv->pkt->len = offs;	950	rcv->pkt->len = offs;
918	memcpy (rcv->pkt->at (0), pkt.at (0), offs);	951	memcpy (rcv->pkt->at (0), pkt.at (0), offs);
919	}	952	}
		953	}
920		954
921	duplicate_request: ;	955	duplicate_request: ;
922	}	956	}
923	else	957	else
924	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);	958	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);
…		…
936	pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class	970	pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
937	pkt [offs++] = 0; pkt [offs++] = 0;	971	pkt [offs++] = 0; pkt [offs++] = 0;
938	pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL	972	pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL
939	pkt [offs++] = 0; pkt [offs++] = 4; // rdlength	973	pkt [offs++] = 0; pkt [offs++] = 4; // rdlength
940		974
941	slog (L_INFO, _("DNS: client %d tries to connect"), client);	975	slog (L_INFO, _("DNS: client %d connects"), client);
942		976
943	pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;	977	pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
944	pkt [offs++] = CMD_IP_REJ;	978	pkt [offs++] = CMD_IP_REJ;
945		979
946	if (0 < client && client <= conns.size ())	980	if (0 < client && client <= conns.size ())
…		…
989	if (dns->send_interval > MAX_SEND_INTERVAL)	1023	if (dns->send_interval > MAX_SEND_INTERVAL)
990	dns->send_interval = MAX_SEND_INTERVAL;	1024	dns->send_interval = MAX_SEND_INTERVAL;
991	}	1025	}
992	else	1026	else
993	{	1027	{
994	#if 1	1028	#if 0
995	dns->send_interval *= 0.999;	1029	dns->send_interval *= 0.999;
996	#endif	1030	#endif
997	if (dns->send_interval < MIN_SEND_INTERVAL)
998	dns->send_interval = MIN_SEND_INTERVAL;
999
1000	// the latency surely puts an upper bound on	1031	// the latency surely puts an upper bound on
1001	// the minimum send interval	1032	// the minimum send interval
1002	double latency = NOW - (*i)->sent;	1033	double latency = NOW - (*i)->sent;
		1034
		1035	if (latency < dns->min_latency)
1003	dns->last_latency = latency;	1036	dns->min_latency = latency;
1004		1037
1005	if (dns->send_interval > latency)	1038	if (dns->send_interval > dns->min_latency * LATENCY_FACTOR)
1006	dns->send_interval = latency;	1039	dns->send_interval = dns->min_latency * LATENCY_FACTOR;
		1040
		1041	if (dns->send_interval < MIN_SEND_INTERVAL)
		1042	dns->send_interval = MIN_SEND_INTERVAL;
1007	}	1043	}
1008		1044
1009	delete *i;	1045	delete *i;
1010	dns_sndpq.erase (i);	1046	dns_sndpq.erase (i);
1011		1047
…		…
1128		1164
1129	pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len);	1165	pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len);
1130		1166
1131	if (pkt->len > 0)	1167	if (pkt->len > 0)
1132	{	1168	{
1133	if (THISNODE->dns_port)	1169	if (ntohs (pkt->flags) & FLAG_RESPONSE)
		1170	dnsv4_client (*pkt);
		1171	else
1134	{	1172	{
1135	dnsv4_server (*pkt);	1173	dnsv4_server (*pkt);
1136	sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len);	1174	sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len);
1137	}	1175	}
1138	else
1139	dnsv4_client (*pkt);
1140		1176
1141	delete pkt;	1177	delete pkt;
1142	}	1178	}
1143	}	1179	}
1144	}	1180	}
1145		1181
1146	bool	1182	bool
1147	connection::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)	1183	vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
1148	{	1184	{
		1185	int client = ntohl (si.host);
		1186
		1187	assert (0 < client && client <= conns.size ());
		1188
		1189	connection *c = conns [client - 1];
		1190
1149	if (!dns)	1191	if (!c->dns)
1150	dns = new dns_connection (this);	1192	c->dns = new dns_connection (c);
1151		1193
1152	if (!dns->snddq.put (pkt))	1194	if (c->dns->snddq.put (pkt))
1153	return false;
1154
1155	dns->tw.trigger ();	1195	c->dns->tw.trigger ();
1156		1196
		1197	// always return true even if the buffer overflows
1157	return true;	1198	return true;
1158	}	1199	}
1159		1200
1160	void	1201	void
1161	connection::dnsv4_reset_connection ()	1202	connection::dnsv4_reset_connection ()
…		…
1187	if (!send)	1228	if (!send)
1188	{	1229	{
1189	send = r;	1230	send = r;
1190		1231
1191	r->retry++;	1232	r->retry++;
1192	r->timeout = NOW + (r->retry * last_latency * 8.);	1233	r->timeout = NOW + (r->retry * min_latency * TIMEOUT_FACTOR);
1193		1234
1194	// the following code changes the query section a bit, forcing	1235	// the following code changes the query section a bit, forcing
1195	// the forwarder to generate a new request	1236	// the forwarder to generate a new request
1196	if (r->stdhdr)	1237	if (r->stdhdr)
1197	{	1238	{
1198	//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);	1239	//printf ("reencoded header for ID %d retry %d:%d:%d (%p)\n", htons (r->pkt->id), THISNODE->id, r->seqno, r->retry);
1199	//encode_header ((char )r->pkt->at (6 2 + 1), THISNODE->id, r->seqno, r->retry);	1240	//encode_header ((char )r->pkt->at (6 2 + 1), THISNODE->id, r->seqno, r->retry);
1200	}	1241	}
1201	}	1242	}
1202	}	1243	}
1203	else	1244	else
1204	NEXT (r->timeout);	1245	NEXT (r->timeout);
1205	}	1246	}
1206		1247
1207	if (last_sent + send_interval <= NOW)
1208	{
1209	if (!send)	1248	if (!send)
		1249	{
		1250	// generate a new packet, if wise
		1251
		1252	if (!established)
1210	{	1253	{
1211	// generate a new packet, if wise	1254	if (vpn->dns_sndpq.empty ())
1212
1213	if (!established)
1214	{	1255	{
1215	if (vpn->dns_sndpq.empty ())
1216	{
1217	send = new dns_snd (this);	1256	send = new dns_snd (this);
1218		1257
1219	cfg.reset (THISNODE->id);	1258	cfg.reset (THISNODE->id);
1220	send->gen_syn_req (cfg);	1259	send->gen_syn_req ();
1221	}
1222	}	1260	}
		1261	}
1223	else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING	1262	else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING
1224	&& !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))	1263	&& !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
		1264	{
		1265	if (last_sent + send_interval <= NOW)
1225	{	1266	{
1226	if (!snddq.empty ())	1267	//printf ("sending data request etc.\n"); //D
		1268	if (!snddq.empty () \|\| last_received + 1. > NOW)
1227	{	1269	{
1228	poll_interval = send_interval;	1270	poll_interval = send_interval;
1229	NEXT (NOW + send_interval);	1271	NEXT (NOW + send_interval);
1230	}	1272	}
1231		1273
1232	send = new dns_snd (this);	1274	send = new dns_snd (this);
1233	send->gen_stream_req (sndseq, snddq);	1275	send->gen_stream_req (sndseq, snddq);
1234	send->timeout = NOW + last_latency * 8.;	1276	send->timeout = NOW + min_latency * TIMEOUT_FACTOR;
1235		1277
1236	sndseq = (sndseq + 1) & SEQNO_MASK;	1278	sndseq = (sndseq + 1) & SEQNO_MASK;
1237	}	1279	}
1238		1280	else
1239	if (send)	1281	NEXT (last_sent + send_interval);
1240	vpn->dns_sndpq.push_back (send);
1241	}	1282	}
1242		1283
1243	if (send)	1284	if (send)
1244	{	1285	vpn->dns_sndpq.push_back (send);
		1286	}
		1287
		1288	if (send)
		1289	{
1245	last_sent = NOW;	1290	last_sent = NOW;
1246	sendto (vpn->dnsv4_fd,	1291	sendto (vpn->dnsv4_fd,
1247	send->pkt->at (0), send->pkt->len, 0,	1292	send->pkt->at (0), send->pkt->len, 0,
1248	vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());	1293	vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
1249	}
1250	}	1294	}
1251	else
1252	NEXT (last_sent + send_interval);
1253		1295
1254	slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d)",	1296	slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)",
1255	poll_interval, send_interval, next - NOW,	1297	poll_interval, send_interval, next - NOW,
1256	vpn->dns_sndpq.size (), snddq.size ());	1298	vpn->dns_sndpq.size (), snddq.size (),
		1299	rcvpq.size ());
1257		1300
1258	// TODO: no idea when this happens, but when next < NOW, we have a problem	1301	// TODO: no idea when this happens, but when next < NOW, we have a problem
1259	if (next < NOW + 0.0001)	1302	if (next < NOW + 0.001)
1260	next = NOW + 0.1;	1303	next = NOW + 0.1;
1261		1304
1262	w.start (next);	1305	w.start (next);
1263	}	1306	}
1264		1307

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Comparing gvpe/src/vpn_dns.C (file contents): Revision 1.17 by pcg, Sat Mar 5 03:47:05 2005 UTC vs. Revision 1.36 by pcg, Thu Mar 17 22:24:31 2005 UTC

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Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.17 by pcg, Sat Mar 5 03:47:05 2005 UTC vs.
Revision 1.36 by pcg, Thu Mar 17 22:24:31 2005 UTC