[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 1.30 by pcg, Mon Mar 14 17:40:01 2005 UTC

…		…
25		25
26	// dns processing is EXTREMELY ugly. For obvious(?) reasons.	26	// dns processing is EXTREMELY ugly. For obvious(?) reasons.
27	// it's a hack, use only in emergency situations please.	27	// it's a hack, use only in emergency situations please.
28		28
29	#include <cstring>	29	#include <cstring>
		30	#include <cassert>
30		31
31	#include <sys/types.h>	32	#include <sys/types.h>
32	#include <sys/socket.h>	33	#include <sys/socket.h>
33	#include <sys/wait.h>	34	#include <sys/wait.h>
34	#include <sys/uio.h>	35	#include <sys/uio.h>
…		…
43		44
44	#include "netcompat.h"	45	#include "netcompat.h"
45		46
46	#include "vpn.h"	47	#include "vpn.h"
47		48
48	#define MIN_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 INITIAL_TIMEOUT 0.1 // retry timeouts	52	#define INITIAL_TIMEOUT 0.1 // retry timeouts
53	#define INITIAL_SYN_TIMEOUT 10. // retry timeout for initial syn	53	#define INITIAL_SYN_TIMEOUT 10. // retry timeout for initial syn
54		54
55	#define MIN_SEND_INTERVAL 0.01 // wait at least this time between sending requests	55	#define MIN_SEND_INTERVAL 0.001 // wait at least this time between sending requests
56	#define MAX_SEND_INTERVAL 0.5 // optimistic?	56	#define MAX_SEND_INTERVAL 2. // optimistic?
57		57
		58	#define LATENCY_FACTOR 0.5 // RTT * LATENCY_FACTOR == sending rate
58	#define MAX_OUTSTANDING 10 // max. outstanding requests	59	#define MAX_OUTSTANDING 2 // max. outstanding requests
59	#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog	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 240 // 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 0x3fff	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) )
…		…
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, int retry = 0)	271	inline void encode_header (char *data, int clientid, int seqno, int retry = 0)
271	{	272	{
272	seqno &= SEQNO_MASK;	273	seqno &= SEQNO_MASK;
273		274
274	u8 hdr[3] = {	275	u8 hdr[3] = {
…		…
356	return true;	357	return true;
357	}	358	}
358		359
359	vpn_packet *byte_stream::get ()	360	vpn_packet *byte_stream::get ()
360	{	361	{
		362	unsigned int len;
		363
		364	for (;;)
		365	{
361	unsigned int len = (data [0] << 8) \| data [1];	366	len = (data [0] << 8) \| data [1];
362		367
363	if (len > MAXSIZE && fill >= 2)	368	if (len <= MAXSIZE \|\| fill < 2)
364	assert (len <= MAXSIZE \|\| fill < 2); // TODO handle this gracefully, connection reset	369	break;
365		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
366	if (fill < len + 2)	376	if (fill < len + 2)
367	return 0;	377	return 0;
368		378
369	vpn_packet *pkt = new vpn_packet;	379	vpn_packet *pkt = new vpn_packet;
370		380
…		…
399	struct dns_cfg	409	struct dns_cfg
400	{	410	{
401	static int next_uid;	411	static int next_uid;
402		412
403	u8 id1, id2, id3, id4;	413	u8 id1, id2, id3, id4;
		414
404	u8 version;	415	u8 version;
		416	u8 flags;
405	u8 rrtype;	417	u8 rrtype;
406	u8 flags;
407	u8 def_ttl;	418	u8 def_ttl;
408	u8 rcv_cdc;	419
409	u8 snd_cdc;
410	u16 max_size;
411	u16 client;	420	u16 client;
412	u16 uid; // to make request unique	421	u16 uid; // to make request unique
413		422
414	u8 reserved[8];	423	u16 max_size;
		424	u8 seq_cdc;
		425	u8 req_cdc;
		426
		427	u8 rep_cdc;
		428	u8 delay; // time in 0.01s units that the server may delay replying packets
		429	u8 r3, r4;
		430
		431	u8 r5, r6, r7, r8;
415		432
416	void reset (int clientid);	433	void reset (int clientid);
417	bool valid ();	434	bool valid ();
418	};	435	};
419		436
…		…
428		445
429	version = 1;	446	version = 1;
430		447
431	rrtype = RR_TYPE_TXT;	448	rrtype = RR_TYPE_TXT;
432	flags = 0;	449	flags = 0;
433	def_ttl = 1;	450	def_ttl = 0;
		451	seq_cdc = 26;
		452	req_cdc = 62;
434	rcv_cdc = 0;	453	rep_cdc = 0;
435	snd_cdc = 62;
436	max_size = ntohs (MAX_PKT_SIZE);	454	max_size = htons (MAX_PKT_SIZE);
437	client = ntohs (clientid);	455	client = htons (clientid);
438	uid = next_uid++;	456	uid = next_uid++;
		457	delay = 0;
439		458
440	memset (reserved, 0, 8);	459	r3 = r4 = 0;
		460	r4 = r5 = r6 = r7 = 0;
441	}	461	}
442		462
443	bool dns_cfg::valid ()	463	bool dns_cfg::valid ()
444	{	464	{
445	return id1 == 'G'	465	return id1 == 'G'
446	&& id2 == 'V'	466	&& id2 == 'V'
447	&& id3 == 'P'	467	&& id3 == 'P'
448	&& id4 == 'E'	468	&& id4 == 'E'
		469	&& seq_cdc == 26
		470	&& req_cdc == 62
		471	&& rep_cdc == 0
449	&& version == 1	472	&& version == 1;
450	&& flags == 0
451	&& rcv_cdc == 0
452	&& snd_cdc == 62
453	&& max_size == ntohs (MAX_PKT_SIZE);
454	}	473	}
455		474
456	struct dns_packet : net_packet	475	struct dns_packet : net_packet
457	{	476	{
458	u16 id;	477	u16 id;
459	u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4	478	u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4
460	u16 qdcount, ancount, nscount, arcount;	479	u16 qdcount, ancount, nscount, arcount;
461		480
462	u8 data[MAXSIZE - 6 * 2];	481	u8 data [MAXSIZE - 6 * 2];
463		482
464	int decode_label (char *data, int size, int &offs);	483	int decode_label (char *data, int size, int &offs);
465	};	484	};
466		485
467	int dns_packet::decode_label (char *data, int size, int &offs)	486	int dns_packet::decode_label (char *data, int size, int &offs)
…		…
498	return data - orig;	517	return data - orig;
499	}	518	}
500		519
501	/////////////////////////////////////////////////////////////////////////////	520	/////////////////////////////////////////////////////////////////////////////
502		521
		522	static u16 dns_id = 0; // TODO: should be per-vpn
		523
		524	static u16 next_id ()
		525	{
		526	if (!dns_id)
		527	dns_id = time (0);
		528
		529	// the simplest lsfr with periodicity 65535 i could find
		530	dns_id = (dns_id << 1)
		531	\| (((dns_id >> 1)
		532	^ (dns_id >> 2)
		533	^ (dns_id >> 4)
		534	^ (dns_id >> 15)) & 1);
		535
		536	return dns_id;
		537	}
		538
		539	struct dns_rcv;
		540	struct dns_snd;
		541
		542	struct dns_connection
		543	{
		544	connection *c;
		545	struct vpn *vpn;
		546
		547	dns_cfg cfg;
		548
		549	bool established;
		550
		551	tstamp last_received;
		552	tstamp last_sent;
		553	double min_latency;
		554	double poll_interval, send_interval;
		555
		556	vector<dns_rcv *> rcvpq;
		557
		558	byte_stream rcvdq; int rcvseq;
		559	byte_stream snddq; int sndseq;
		560
		561	void time_cb (time_watcher &w); time_watcher tw;
		562	void receive_rep (dns_rcv *r);
		563
		564	dns_connection (connection *c);
		565	~dns_connection ();
		566	};
		567
503	struct dns_snd	568	struct dns_snd
504	{	569	{
505	dns_packet *pkt;	570	dns_packet *pkt;
506	tstamp timeout, sent;	571	tstamp timeout, sent;
507	int retry;	572	int retry;
508	struct dns_connection *dns;	573	struct dns_connection *dns;
509	int seqno;	574	int seqno;
510	bool stdhdr;	575	bool stdhdr;
511		576
512	void gen_stream_req (int seqno, byte_stream &stream);	577	void gen_stream_req (int seqno, byte_stream &stream);
513	void gen_syn_req (const dns_cfg &cfg);	578	void gen_syn_req ();
514		579
515	dns_snd (dns_connection *dns);	580	dns_snd (dns_connection *dns);
516	~dns_snd ();	581	~dns_snd ();
517	};	582	};
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		583
533	dns_snd::dns_snd (dns_connection *dns)	584	dns_snd::dns_snd (dns_connection *dns)
534	: dns (dns)	585	: dns (dns)
535	{	586	{
536	timeout = 0;	587	timeout = 0;
…		…
581		632
582	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);	633	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
583	pkt->qdcount = htons (1);	634	pkt->qdcount = htons (1);
584		635
585	int offs = 6*2;	636	int offs = 6*2;
586	int dlen = MAX_DOMAIN_SIZE - (strlen (THISNODE->domain) + 2);	637	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,	638	// 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	639	// so we need to have space for 2*MAX_DOMAIN_SIZE + header + extra
589		640
590	char enc[256], *encp = enc;	641	char enc[256], *encp = enc;
591	encode_header (enc, THISNODE->id, seqno);	642	encode_header (enc, THISNODE->id, seqno);
…		…
609	encp += lbllen;	660	encp += lbllen;
610		661
611	enclen -= lbllen;	662	enclen -= lbllen;
612	}	663	}
613		664
614	append_domain (*pkt, offs, THISNODE->domain);	665	append_domain (*pkt, offs, dns->c->conf->domain);
615		666
616	(*pkt)[offs++] = 0;	667	(*pkt)[offs++] = 0;
617	(pkt)[offs++] = RR_TYPE_ANY >> 8; (pkt)[offs++] = RR_TYPE_ANY;	668	(pkt)[offs++] = RR_TYPE_ANY >> 8; (pkt)[offs++] = RR_TYPE_ANY;
618	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;	669	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;
619		670
620	pkt->len = offs;	671	pkt->len = offs;
621	}	672	}
622		673
623	void dns_snd::gen_syn_req (const dns_cfg &cfg)	674	void dns_snd::gen_syn_req ()
624	{	675	{
625	timeout = NOW + INITIAL_SYN_TIMEOUT;	676	timeout = NOW + INITIAL_SYN_TIMEOUT;
626		677
627	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);	678	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
628	pkt->qdcount = htons (1);	679	pkt->qdcount = htons (1);
629		680
630	int offs = 6*2;	681	int offs = 6 * 2;
631		682
632	int elen = cdc26.encode ((char )pkt->at (offs + 1), (u8 )&cfg, sizeof (dns_cfg));	683	int elen = cdc26.encode ((char )pkt->at (offs + 1), (u8 )&dns->cfg, sizeof (dns_cfg));
633		684
634	assert (elen <= MAX_LBL_SIZE);	685	assert (elen <= MAX_LBL_SIZE);
635		686
636	(*pkt)[offs] = elen;	687	(*pkt)[offs] = elen;
637	offs += elen + 1;	688	offs += elen + 1;
638	append_domain (*pkt, offs, THISNODE->domain);	689	append_domain (*pkt, offs, dns->c->conf->domain);
639		690
640	(*pkt)[offs++] = 0;	691	(*pkt)[offs++] = 0;
641	(pkt)[offs++] = RR_TYPE_A >> 8; (pkt)[offs++] = RR_TYPE_A;	692	(pkt)[offs++] = RR_TYPE_A >> 8; (pkt)[offs++] = RR_TYPE_A;
642	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;	693	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;
643		694
…		…
666	delete pkt;	717	delete pkt;
667	}	718	}
668		719
669	/////////////////////////////////////////////////////////////////////////////	720	/////////////////////////////////////////////////////////////////////////////
670		721
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)	722	dns_connection::dns_connection (connection *c)
698	: c (c)	723	: c (c)
699	, rcvdq (MAX_BACKLOG * 2)	724	, rcvdq (MAX_BACKLOG * 2)
700	, snddq (MAX_BACKLOG * 2)	725	, snddq (MAX_BACKLOG * 2)
701	, tw (this, &dns_connection::time_cb)	726	, tw (this, &dns_connection::time_cb)
…		…
705	established = false;	730	established = false;
706		731
707	rcvseq = sndseq = 0;	732	rcvseq = sndseq = 0;
708		733
709	last_sent = last_received = 0;	734	last_sent = last_received = 0;
710	poll_interval = MIN_POLL_INTERVAL;	735	poll_interval = 0.5; // starting here
711	send_interval = 0.5; // starting rate	736	send_interval = 0.5; // starting rate
712	last_latency = INITIAL_TIMEOUT;	737	min_latency = INITIAL_TIMEOUT;
713	}	738	}
714		739
715	dns_connection::~dns_connection ()	740	dns_connection::~dns_connection ()
716	{	741	{
717	for (vector<dns_rcv *>::iterator i = rcvpq.begin ();	742	for (vector<dns_rcv *>::iterator i = rcvpq.begin ();
…		…
730	poll_interval = send_interval;	755	poll_interval = send_interval;
731	}	756	}
732	else	757	else
733	{	758	{
734	poll_interval *= 1.5;	759	poll_interval *= 1.5;
		760
735	if (poll_interval > MAX_POLL_INTERVAL)	761	if (poll_interval > MAX_POLL_INTERVAL)
736	poll_interval = MAX_POLL_INTERVAL;	762	poll_interval = MAX_POLL_INTERVAL;
737	}	763	}
738		764
739	rcvpq.push_back (r);	765	rcvpq.push_back (r);
…		…
765	}	791	}
766		792
767	while (vpn_packet *pkt = rcvdq.get ())	793	while (vpn_packet *pkt = rcvdq.get ())
768	{	794	{
769	sockinfo si;	795	sockinfo si;
770	si.host = 0; si.port = 0; si.prot = PROT_DNSv4;	796	si.host = 0x01010101; si.port = htons (c->conf->id); si.prot = PROT_DNSv4;
771		797
772	vpn->recv_vpn_packet (pkt, si);	798	vpn->recv_vpn_packet (pkt, si);
773		799
774	delete pkt;	800	delete pkt;
775	}	801	}
…		…
789	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);	815	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);
790		816
791	if (0 == (flags & (FLAG_RESPONSE \| FLAG_OP_MASK))	817	if (0 == (flags & (FLAG_RESPONSE \| FLAG_OP_MASK))
792	&& pkt.qdcount == htons (1))	818	&& pkt.qdcount == htons (1))
793	{	819	{
794	char qname[MAXSIZE];	820	char qname [MAXSIZE];
795	int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);	821	int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
796		822
797	u16 qtype = pkt [offs++] << 8; qtype \|= pkt [offs++];	823	u16 qtype = pkt [offs++] << 8; qtype \|= pkt [offs++];
798	u16 qclass = pkt [offs++] << 8; qclass \|= pkt [offs++];	824	u16 qclass = pkt [offs++] << 8; qclass \|= pkt [offs++];
799		825
…		…
806		832
807	int dlen = strlen (THISNODE->domain);	833	int dlen = strlen (THISNODE->domain);
808		834
809	if (qclass == RR_CLASS_IN	835	if (qclass == RR_CLASS_IN
810	&& qlen > dlen + 1	836	&& qlen > dlen + 1
811	&& !memcmp (qname + qlen - dlen - 1, THISNODE->domain, dlen))	837	&& !memcmp (qname + qlen - (dlen + 1), THISNODE->domain, dlen))
812	{	838	{
813	// now generate reply	839	// now generate reply
814	pkt.ancount = htons (1); // one answer RR	840	pkt.ancount = htons (1); // one answer RR
815	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_OK);	841	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_OK);
816		842
…		…
857	// new packet, queue	883	// new packet, queue
858	rcv = new dns_rcv (seqno, data, datalen);	884	rcv = new dns_rcv (seqno, data, datalen);
859	dns->receive_rep (rcv);	885	dns->receive_rep (rcv);
860	}	886	}
861		887
		888	{
862	pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section	889	pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section
863		890
864	int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A;	891	int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A;
865	pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type	892	pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type
866	pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class	893	pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
867	pkt [offs++] = 0; pkt [offs++] = 0;	894	pkt [offs++] = 0; pkt [offs++] = 0;
868	pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL	895	pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL
869		896
870	int rdlen_offs = offs += 2;	897	int rdlen_offs = offs += 2;
871		898
		899	if (dns)
		900	{
872	int dlen = (dns ? ntohs (dns->cfg.max_size) : MAX_PKT_SIZE) - offs;	901	int dlen = ntohs (dns->cfg.max_size) - offs;
		902
873	// bind doesn't compress well, so reduce further by one label length	903	// bind doesn't compress well, so reduce further by one label length
874	dlen -= qlen;	904	dlen -= qlen;
875		905
876	if (dns)
877	{
878	// only put data into in-order sequence packets, if	906	// only put data into in-order sequence packets, if
879	// we receive out-of-order packets we generate empty	907	// we receive out-of-order packets we generate empty
880	// replies	908	// replies
881	while (dlen > 1 && !dns->snddq.empty () && in_seq)	909	while (dlen > 1 && !dns->snddq.empty () && in_seq)
882	{	910	{
883	int txtlen = dlen <= 255 ? dlen - 1 : 255;	911	int txtlen = dlen <= 255 ? dlen - 1 : 255;
884		912
885	if (txtlen > dns->snddq.size ())	913	if (txtlen > dns->snddq.size ())
886	txtlen = dns->snddq.size ();	914	txtlen = dns->snddq.size ();
887		915
888	pkt[offs++] = txtlen;	916	pkt[offs++] = txtlen;
889	memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);	917	memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
890	offs += txtlen;	918	offs += txtlen;
891	dns->snddq.remove (txtlen);	919	dns->snddq.remove (txtlen);
892		920
893	dlen -= txtlen + 1;	921	dlen -= txtlen + 1;
894	}	922	}
895		923
896	// avoid empty TXT rdata	924	// avoid empty TXT rdata
897	if (offs == rdlen_offs)	925	if (offs == rdlen_offs)
898	pkt[offs++] = 0;	926	pkt[offs++] = 0;
899		927
900	slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());	928	slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
901	}	929	}
902	else	930	else
903	{	931	{
904	// send RST	932	// send RST
905	pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;	933	pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
906	pkt [offs++] = CMD_IP_RST;	934	pkt [offs++] = CMD_IP_RST;
907	}	935	}
908		936
909	int rdlen = offs - rdlen_offs;	937	int rdlen = offs - rdlen_offs;
910		938
911	pkt [rdlen_offs - 2] = rdlen >> 8;	939	pkt [rdlen_offs - 2] = rdlen >> 8;
912	pkt [rdlen_offs - 1] = rdlen;	940	pkt [rdlen_offs - 1] = rdlen;
913		941
914	if (dns)	942	if (dns)
915	{	943	{
916	// now update dns_rcv copy	944	// now update dns_rcv copy
917	rcv->pkt->len = offs;	945	rcv->pkt->len = offs;
918	memcpy (rcv->pkt->at (0), pkt.at (0), offs);	946	memcpy (rcv->pkt->at (0), pkt.at (0), offs);
919	}	947	}
		948	}
920		949
921	duplicate_request: ;	950	duplicate_request: ;
922	}	951	}
923	else	952	else
924	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);	953	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);
…		…
936	pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class	965	pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
937	pkt [offs++] = 0; pkt [offs++] = 0;	966	pkt [offs++] = 0; pkt [offs++] = 0;
938	pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL	967	pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL
939	pkt [offs++] = 0; pkt [offs++] = 4; // rdlength	968	pkt [offs++] = 0; pkt [offs++] = 4; // rdlength
940		969
941	slog (L_INFO, _("DNS: client %d tries to connect"), client);	970	slog (L_INFO, _("DNS: client %d connects"), client);
942		971
943	pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;	972	pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
944	pkt [offs++] = CMD_IP_REJ;	973	pkt [offs++] = CMD_IP_REJ;
945		974
946	if (0 < client && client <= conns.size ())	975	if (0 < client && client <= conns.size ())
…		…
989	if (dns->send_interval > MAX_SEND_INTERVAL)	1018	if (dns->send_interval > MAX_SEND_INTERVAL)
990	dns->send_interval = MAX_SEND_INTERVAL;	1019	dns->send_interval = MAX_SEND_INTERVAL;
991	}	1020	}
992	else	1021	else
993	{	1022	{
994	#if 1	1023	#if 0
995	dns->send_interval *= 0.999;	1024	dns->send_interval *= 0.999;
996	#endif	1025	#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	1026	// the latency surely puts an upper bound on
1001	// the minimum send interval	1027	// the minimum send interval
1002	double latency = NOW - (*i)->sent;	1028	double latency = NOW - (*i)->sent;
		1029
		1030	if (latency < dns->min_latency)
1003	dns->last_latency = latency;	1031	dns->min_latency = latency;
1004		1032
1005	if (dns->send_interval > latency)	1033	if (dns->send_interval > dns->min_latency * LATENCY_FACTOR)
1006	dns->send_interval = latency;	1034	dns->send_interval = dns->min_latency * LATENCY_FACTOR;
		1035
		1036	if (dns->send_interval < MIN_SEND_INTERVAL)
		1037	dns->send_interval = MIN_SEND_INTERVAL;
1007	}	1038	}
1008		1039
1009	delete *i;	1040	delete *i;
1010	dns_sndpq.erase (i);	1041	dns_sndpq.erase (i);
1011		1042
…		…
1128		1159
1129	pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len);	1160	pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len);
1130		1161
1131	if (pkt->len > 0)	1162	if (pkt->len > 0)
1132	{	1163	{
1133	if (THISNODE->dns_port)	1164	if (ntohs (pkt->flags) & FLAG_RESPONSE)
		1165	dnsv4_client (*pkt);
		1166	else
1134	{	1167	{
1135	dnsv4_server (*pkt);	1168	dnsv4_server (*pkt);
1136	sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len);	1169	sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len);
1137	}	1170	}
1138	else
1139	dnsv4_client (*pkt);
1140		1171
1141	delete pkt;	1172	delete pkt;
1142	}	1173	}
1143	}	1174	}
1144	}	1175	}
1145		1176
1146	bool	1177	bool
1147	connection::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)	1178	vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
1148	{	1179	{
		1180	int client = ntohs (si.port);
		1181
		1182	assert (0 < client && client <= conns.size ());
		1183
		1184	connection *c = conns [client - 1];
		1185
1149	if (!dns)	1186	if (!c->dns)
1150	dns = new dns_connection (this);	1187	c->dns = new dns_connection (c);
1151		1188
1152	if (!dns->snddq.put (pkt))	1189	if (!c->dns->snddq.put (pkt))
1153	return false;	1190	return false;
1154		1191
1155	dns->tw.trigger ();	1192	c->dns->tw.trigger ();
1156		1193
1157	return true;	1194	return true;
1158	}	1195	}
1159		1196
1160	void	1197	void
…		…
1187	if (!send)	1224	if (!send)
1188	{	1225	{
1189	send = r;	1226	send = r;
1190		1227
1191	r->retry++;	1228	r->retry++;
1192	r->timeout = NOW + (r->retry * last_latency * 8.);	1229	r->timeout = NOW + (r->retry * min_latency * 8.);
1193		1230
1194	// the following code changes the query section a bit, forcing	1231	// the following code changes the query section a bit, forcing
1195	// the forwarder to generate a new request	1232	// the forwarder to generate a new request
1196	if (r->stdhdr)	1233	if (r->stdhdr)
1197	{	1234	{
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);	1235	//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);	1236	//encode_header ((char )r->pkt->at (6 2 + 1), THISNODE->id, r->seqno, r->retry);
1200	}	1237	}
1201	}	1238	}
1202	}	1239	}
1203	else	1240	else
1204	NEXT (r->timeout);	1241	NEXT (r->timeout);
1205	}	1242	}
1206		1243
1207	if (last_sent + send_interval <= NOW)
1208	{
1209	if (!send)	1244	if (!send)
		1245	{
		1246	// generate a new packet, if wise
		1247
		1248	if (!established)
1210	{	1249	{
1211	// generate a new packet, if wise	1250	if (vpn->dns_sndpq.empty ())
1212
1213	if (!established)
1214	{	1251	{
1215	if (vpn->dns_sndpq.empty ())
1216	{
1217	send = new dns_snd (this);	1252	send = new dns_snd (this);
1218		1253
1219	cfg.reset (THISNODE->id);	1254	cfg.reset (THISNODE->id);
1220	send->gen_syn_req (cfg);	1255	send->gen_syn_req ();
1221	}
1222	}	1256	}
		1257	}
1223	else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING	1258	else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING
1224	&& !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))	1259	&& !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
		1260	{
		1261	if (last_sent + send_interval <= NOW)
1225	{	1262	{
1226	if (!snddq.empty ())	1263	//printf ("sending data request etc.\n"); //D
		1264	if (!snddq.empty () \|\| last_received + 1. > NOW)
1227	{	1265	{
1228	poll_interval = send_interval;	1266	poll_interval = send_interval;
1229	NEXT (NOW + send_interval);	1267	NEXT (NOW + send_interval);
1230	}	1268	}
1231		1269
1232	send = new dns_snd (this);	1270	send = new dns_snd (this);
1233	send->gen_stream_req (sndseq, snddq);	1271	send->gen_stream_req (sndseq, snddq);
1234	send->timeout = NOW + last_latency * 8.;	1272	send->timeout = NOW + min_latency * 8.;
1235		1273
1236	sndseq = (sndseq + 1) & SEQNO_MASK;	1274	sndseq = (sndseq + 1) & SEQNO_MASK;
1237	}	1275	}
1238		1276	else
1239	if (send)	1277	NEXT (last_sent + send_interval);
1240	vpn->dns_sndpq.push_back (send);
1241	}	1278	}
1242		1279
1243	if (send)	1280	if (send)
1244	{	1281	vpn->dns_sndpq.push_back (send);
		1282	}
		1283
		1284	if (send)
		1285	{
1245	last_sent = NOW;	1286	last_sent = NOW;
1246	sendto (vpn->dnsv4_fd,	1287	sendto (vpn->dnsv4_fd,
1247	send->pkt->at (0), send->pkt->len, 0,	1288	send->pkt->at (0), send->pkt->len, 0,
1248	vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());	1289	vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
1249	}
1250	}	1290	}
1251	else
1252	NEXT (last_sent + send_interval);
1253		1291
1254	slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d)",	1292	slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)",
1255	poll_interval, send_interval, next - NOW,	1293	poll_interval, send_interval, next - NOW,
1256	vpn->dns_sndpq.size (), snddq.size ());	1294	vpn->dns_sndpq.size (), snddq.size (),
		1295	rcvpq.size ());
1257		1296
1258	// TODO: no idea when this happens, but when next < NOW, we have a problem	1297	// TODO: no idea when this happens, but when next < NOW, we have a problem
1259	if (next < NOW + 0.0001)	1298	if (next < NOW + 0.001)
1260	next = NOW + 0.1;	1299	next = NOW + 0.1;
1261		1300
1262	w.start (next);	1301	w.start (next);
1263	}	1302	}
1264		1303

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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 1.30 by pcg, Mon Mar 14 17:40:01 2005 UTC

Diff Legend

Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.17 by pcg, Sat Mar 5 03:47:05 2005 UTC vs.
Revision 1.30 by pcg, Mon Mar 14 17:40:01 2005 UTC