[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 1.37 by pcg, Wed Mar 23 17:03:58 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 2. // retry timeout for initial syn
54		54
55	#define MIN_SEND_INTERVAL 0.01 // wait at least this time between sending requests
56	#define MAX_SEND_INTERVAL 0.5 // optimistic?	55	#define MAX_SEND_INTERVAL 2. // optimistic?
57		56
58	#define MAX_OUTSTANDING 10 // max. outstanding requests
59	#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog	57	#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	58	#define MAX_BACKLOG (64*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE
61		59
62	#define MAX_DOMAIN_SIZE 220 // 255 is legal limit, but bind doesn't compress well	60	#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	61	// 240 leaves about 4 bytes of server reply data
64	// every two request bytes less give room for one reply byte	62	// every request byte less give room for two reply bytes
65		63
66	#define SEQNO_MASK 0x3fff	64	#define SEQNO_MASK 0x3fff
67	#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )	65	#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )
68		66
69	#define MAX_LBL_SIZE 63	67	#define MAX_LBL_SIZE 63
…		…
264	static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO");	262	static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO");
265		263
266	/////////////////////////////////////////////////////////////////////////////	264	/////////////////////////////////////////////////////////////////////////////
267		265
268	#define HDRSIZE 6	266	#define HDRSIZE 6
269		267
270	inline void encode_header (char *data, int clientid, int seqno, int retry = 0)	268	inline void encode_header (char *data, int clientid, int seqno, int retry = 0)
271	{	269	{
272	seqno &= SEQNO_MASK;	270	seqno &= SEQNO_MASK;
273		271
274	u8 hdr[3] = {	272	u8 hdr[3] = {
…		…
356	return true;	354	return true;
357	}	355	}
358		356
359	vpn_packet *byte_stream::get ()	357	vpn_packet *byte_stream::get ()
360	{	358	{
		359	unsigned int len;
		360
		361	for (;;)
		362	{
361	unsigned int len = (data [0] << 8) \| data [1];	363	len = (data [0] << 8) \| data [1];
362		364
363	if (len > MAXSIZE && fill >= 2)	365	if (len <= MAXSIZE \|\| fill < 2)
364	assert (len <= MAXSIZE \|\| fill < 2); // TODO handle this gracefully, connection reset	366	break;
365		367
		368	// TODO: handle this better than skipping, e.g. by reset
		369	slog (L_DEBUG, _("DNS: corrupted packet stream skipping a byte..."));
		370	remove (1);
		371	}
		372
366	if (fill < len + 2)	373	if (fill < len + 2)
367	return 0;	374	return 0;
368		375
369	vpn_packet *pkt = new vpn_packet;	376	vpn_packet *pkt = new vpn_packet;
370		377
…		…
399	struct dns_cfg	406	struct dns_cfg
400	{	407	{
401	static int next_uid;	408	static int next_uid;
402		409
403	u8 id1, id2, id3, id4;	410	u8 id1, id2, id3, id4;
		411
404	u8 version;	412	u8 version;
		413	u8 flags;
405	u8 rrtype;	414	u8 rrtype;
406	u8 flags;
407	u8 def_ttl;	415	u8 def_ttl;
408	u8 rcv_cdc;	416
409	u8 snd_cdc;
410	u16 max_size;
411	u16 client;	417	u16 client;
412	u16 uid; // to make request unique	418	u16 uid; // to make request unique
413		419
414	u8 reserved[8];	420	u16 max_size;
		421	u8 seq_cdc;
		422	u8 req_cdc;
		423
		424	u8 rep_cdc;
		425	u8 delay; // time in 0.01s units that the server may delay replying packets
		426	u8 r3, r4;
		427
		428	u8 r5, r6, r7, r8;
415		429
416	void reset (int clientid);	430	void reset (int clientid);
417	bool valid ();	431	bool valid ();
418	};	432	};
419		433
…		…
428		442
429	version = 1;	443	version = 1;
430		444
431	rrtype = RR_TYPE_TXT;	445	rrtype = RR_TYPE_TXT;
432	flags = 0;	446	flags = 0;
433	def_ttl = 1;	447	def_ttl = 0;
		448	seq_cdc = 26;
		449	req_cdc = 62;
434	rcv_cdc = 0;	450	rep_cdc = 0;
435	snd_cdc = 62;
436	max_size = ntohs (MAX_PKT_SIZE);	451	max_size = htons (MAX_PKT_SIZE);
437	client = ntohs (clientid);	452	client = htons (clientid);
438	uid = next_uid++;	453	uid = next_uid++;
		454	delay = 0;
439		455
440	memset (reserved, 0, 8);	456	r3 = r4 = 0;
		457	r4 = r5 = r6 = r7 = 0;
441	}	458	}
442		459
443	bool dns_cfg::valid ()	460	bool dns_cfg::valid ()
444	{	461	{
445	return id1 == 'G'	462	return id1 == 'G'
446	&& id2 == 'V'	463	&& id2 == 'V'
447	&& id3 == 'P'	464	&& id3 == 'P'
448	&& id4 == 'E'	465	&& id4 == 'E'
		466	&& seq_cdc == 26
		467	&& req_cdc == 62
		468	&& rep_cdc == 0
449	&& version == 1	469	&& version == 1;
450	&& flags == 0
451	&& rcv_cdc == 0
452	&& snd_cdc == 62
453	&& max_size == ntohs (MAX_PKT_SIZE);
454	}	470	}
455		471
456	struct dns_packet : net_packet	472	struct dns_packet : net_packet
457	{	473	{
458	u16 id;	474	u16 id;
459	u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4	475	u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4
460	u16 qdcount, ancount, nscount, arcount;	476	u16 qdcount, ancount, nscount, arcount;
461		477
462	u8 data[MAXSIZE - 6 * 2];	478	u8 data [MAXSIZE - 6 * 2];
463		479
464	int decode_label (char *data, int size, int &offs);	480	int decode_label (char *data, int size, int &offs);
465	};	481	};
466		482
467	int dns_packet::decode_label (char *data, int size, int &offs)	483	int dns_packet::decode_label (char *data, int size, int &offs)
…		…
498	return data - orig;	514	return data - orig;
499	}	515	}
500		516
501	/////////////////////////////////////////////////////////////////////////////	517	/////////////////////////////////////////////////////////////////////////////
502		518
		519	static u16 dns_id = 0; // TODO: should be per-vpn
		520
		521	static u16 next_id ()
		522	{
		523	if (!dns_id)
		524	dns_id = time (0);
		525
		526	// the simplest lsfr with periodicity 65535 i could find
		527	dns_id = (dns_id << 1)
		528	\| (((dns_id >> 1)
		529	^ (dns_id >> 2)
		530	^ (dns_id >> 4)
		531	^ (dns_id >> 15)) & 1);
		532
		533	return dns_id;
		534	}
		535
		536	struct dns_rcv;
		537	struct dns_snd;
		538
		539	struct dns_connection
		540	{
		541	connection *c;
		542	struct vpn *vpn;
		543
		544	dns_cfg cfg;
		545
		546	bool established;
		547
		548	tstamp last_received;
		549	tstamp last_sent;
		550	double min_latency;
		551	double poll_interval, send_interval;
		552
		553	vector<dns_rcv *> rcvpq;
		554
		555	byte_stream rcvdq; int rcvseq; int repseq;
		556	byte_stream snddq; int sndseq;
		557
		558	void time_cb (time_watcher &w); time_watcher tw;
		559	void receive_rep (dns_rcv *r);
		560
		561	dns_connection (connection *c);
		562	~dns_connection ();
		563	};
		564
503	struct dns_snd	565	struct dns_snd
504	{	566	{
505	dns_packet *pkt;	567	dns_packet *pkt;
506	tstamp timeout, sent;	568	tstamp timeout, sent;
507	int retry;	569	int retry;
508	struct dns_connection *dns;	570	struct dns_connection *dns;
509	int seqno;	571	int seqno;
510	bool stdhdr;	572	bool stdhdr;
511		573
512	void gen_stream_req (int seqno, byte_stream &stream);	574	void gen_stream_req (int seqno, byte_stream &stream);
513	void gen_syn_req (const dns_cfg &cfg);	575	void gen_syn_req ();
514		576
515	dns_snd (dns_connection *dns);	577	dns_snd (dns_connection *dns);
516	~dns_snd ();	578	~dns_snd ();
517	};	579	};
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		580
533	dns_snd::dns_snd (dns_connection *dns)	581	dns_snd::dns_snd (dns_connection *dns)
534	: dns (dns)	582	: dns (dns)
535	{	583	{
536	timeout = 0;	584	timeout = 0;
…		…
581		629
582	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);	630	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
583	pkt->qdcount = htons (1);	631	pkt->qdcount = htons (1);
584		632
585	int offs = 6*2;	633	int offs = 6*2;
586	int dlen = MAX_DOMAIN_SIZE - (strlen (THISNODE->domain) + 2);	634	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,	635	// 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	636	// so we need to have space for 2*MAX_DOMAIN_SIZE + header + extra
589		637
590	char enc[256], *encp = enc;	638	char enc[256], *encp = enc;
591	encode_header (enc, THISNODE->id, seqno);	639	encode_header (enc, THISNODE->id, seqno);
…		…
609	encp += lbllen;	657	encp += lbllen;
610		658
611	enclen -= lbllen;	659	enclen -= lbllen;
612	}	660	}
613		661
614	append_domain (*pkt, offs, THISNODE->domain);	662	append_domain (*pkt, offs, dns->c->conf->domain);
615		663
616	(*pkt)[offs++] = 0;	664	(*pkt)[offs++] = 0;
617	(pkt)[offs++] = RR_TYPE_ANY >> 8; (pkt)[offs++] = RR_TYPE_ANY;	665	(pkt)[offs++] = RR_TYPE_ANY >> 8; (pkt)[offs++] = RR_TYPE_ANY;
618	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;	666	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;
619		667
620	pkt->len = offs;	668	pkt->len = offs;
621	}	669	}
622		670
623	void dns_snd::gen_syn_req (const dns_cfg &cfg)	671	void dns_snd::gen_syn_req ()
624	{	672	{
625	timeout = NOW + INITIAL_SYN_TIMEOUT;	673	timeout = NOW + INITIAL_SYN_TIMEOUT;
626		674
627	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);	675	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
628	pkt->qdcount = htons (1);	676	pkt->qdcount = htons (1);
629		677
630	int offs = 6*2;	678	int offs = 6 * 2;
631		679
632	int elen = cdc26.encode ((char )pkt->at (offs + 1), (u8 )&cfg, sizeof (dns_cfg));	680	int elen = cdc26.encode ((char )pkt->at (offs + 1), (u8 )&dns->cfg, sizeof (dns_cfg));
633		681
634	assert (elen <= MAX_LBL_SIZE);	682	assert (elen <= MAX_LBL_SIZE);
635		683
636	(*pkt)[offs] = elen;	684	(*pkt)[offs] = elen;
637	offs += elen + 1;	685	offs += elen + 1;
638	append_domain (*pkt, offs, THISNODE->domain);	686	append_domain (*pkt, offs, dns->c->conf->domain);
639		687
640	(*pkt)[offs++] = 0;	688	(*pkt)[offs++] = 0;
641	(pkt)[offs++] = RR_TYPE_A >> 8; (pkt)[offs++] = RR_TYPE_A;	689	(pkt)[offs++] = RR_TYPE_A >> 8; (pkt)[offs++] = RR_TYPE_A;
642	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;	690	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;
643		691
…		…
666	delete pkt;	714	delete pkt;
667	}	715	}
668		716
669	/////////////////////////////////////////////////////////////////////////////	717	/////////////////////////////////////////////////////////////////////////////
670		718
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)	719	dns_connection::dns_connection (connection *c)
698	: c (c)	720	: c (c)
699	, rcvdq (MAX_BACKLOG * 2)	721	, rcvdq (MAX_BACKLOG * 2)
700	, snddq (MAX_BACKLOG * 2)	722	, snddq (MAX_BACKLOG)
701	, tw (this, &dns_connection::time_cb)	723	, tw (this, &dns_connection::time_cb)
702	{	724	{
703	vpn = c->vpn;	725	vpn = c->vpn;
704		726
705	established = false;	727	established = false;
706		728
707	rcvseq = sndseq = 0;	729	rcvseq = repseq = sndseq = 0;
708		730
709	last_sent = last_received = 0;	731	last_sent = last_received = 0;
710	poll_interval = MIN_POLL_INTERVAL;	732	poll_interval = 0.5; // starting here
711	send_interval = 0.5; // starting rate	733	send_interval = 0.5; // starting rate
712	last_latency = INITIAL_TIMEOUT;	734	min_latency = INITIAL_TIMEOUT;
713	}	735	}
714		736
715	dns_connection::~dns_connection ()	737	dns_connection::~dns_connection ()
716	{	738	{
717	for (vector<dns_rcv *>::iterator i = rcvpq.begin ();	739	for (vector<dns_rcv *>::iterator i = rcvpq.begin ();
…		…
730	poll_interval = send_interval;	752	poll_interval = send_interval;
731	}	753	}
732	else	754	else
733	{	755	{
734	poll_interval *= 1.5;	756	poll_interval *= 1.5;
		757
735	if (poll_interval > MAX_POLL_INTERVAL)	758	if (poll_interval > MAX_POLL_INTERVAL)
736	poll_interval = MAX_POLL_INTERVAL;	759	poll_interval = MAX_POLL_INTERVAL;
737	}	760	}
738		761
739	rcvpq.push_back (r);	762	rcvpq.push_back (r);
…		…
765	}	788	}
766		789
767	while (vpn_packet *pkt = rcvdq.get ())	790	while (vpn_packet *pkt = rcvdq.get ())
768	{	791	{
769	sockinfo si;	792	sockinfo si;
770	si.host = 0; si.port = 0; si.prot = PROT_DNSv4;	793	si.host = htonl (c->conf->id); si.port = 0; si.prot = PROT_DNSv4;
771		794
772	vpn->recv_vpn_packet (pkt, si);	795	vpn->recv_vpn_packet (pkt, si);
773		796
774	delete pkt;	797	delete pkt;
775	}	798	}
…		…
789	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);	812	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);
790		813
791	if (0 == (flags & (FLAG_RESPONSE \| FLAG_OP_MASK))	814	if (0 == (flags & (FLAG_RESPONSE \| FLAG_OP_MASK))
792	&& pkt.qdcount == htons (1))	815	&& pkt.qdcount == htons (1))
793	{	816	{
794	char qname[MAXSIZE];	817	char qname [MAXSIZE];
795	int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);	818	int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
796		819
797	u16 qtype = pkt [offs++] << 8; qtype \|= pkt [offs++];	820	u16 qtype = pkt [offs++] << 8; qtype \|= pkt [offs++];
798	u16 qclass = pkt [offs++] << 8; qclass \|= pkt [offs++];	821	u16 qclass = pkt [offs++] << 8; qclass \|= pkt [offs++];
799		822
…		…
806		829
807	int dlen = strlen (THISNODE->domain);	830	int dlen = strlen (THISNODE->domain);
808		831
809	if (qclass == RR_CLASS_IN	832	if (qclass == RR_CLASS_IN
810	&& qlen > dlen + 1	833	&& qlen > dlen + 1
811	&& !memcmp (qname + qlen - dlen - 1, THISNODE->domain, dlen))	834	&& !memcmp (qname + qlen - (dlen + 1), THISNODE->domain, dlen))
812	{	835	{
813	// now generate reply	836	// now generate reply
814	pkt.ancount = htons (1); // one answer RR	837	pkt.ancount = htons (1); // one answer RR
815	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_OK);	838	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_OK);
816		839
…		…
829	if (0 < client && client <= conns.size ())	852	if (0 < client && client <= conns.size ())
830	{	853	{
831	connection *c = conns [client - 1];	854	connection *c = conns [client - 1];
832	dns_connection *dns = c->dns;	855	dns_connection *dns = c->dns;
833	dns_rcv *rcv;	856	dns_rcv *rcv;
834	bool in_seq;
835		857
836	if (dns)	858	if (dns)
837	{	859	{
838	for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); )	860	for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); )
839	if (SEQNO_EQ ((*i)->seqno, seqno))	861	if (SEQNO_EQ ((*i)->seqno, seqno))
…		…
850	memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len);	872	memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len);
851		873
852	goto duplicate_request;	874	goto duplicate_request;
853	}	875	}
854		876
855	in_seq = dns->rcvseq == seqno;
856
857	// new packet, queue	877	// new packet, queue
858	rcv = new dns_rcv (seqno, data, datalen);	878	rcv = new dns_rcv (seqno, data, datalen);
859	dns->receive_rep (rcv);	879	dns->receive_rep (rcv);
860	}	880	}
861		881
		882	{
862	pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section	883	pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section
863		884
864	int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A;	885	int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A;
865	pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type	886	pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type
866	pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class	887	pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
867	pkt [offs++] = 0; pkt [offs++] = 0;	888	pkt [offs++] = 0; pkt [offs++] = 0;
868	pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL	889	pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL
869		890
870	int rdlen_offs = offs += 2;	891	int rdlen_offs = offs += 2;
871		892
		893	if (dns)
		894	{
872	int dlen = (dns ? ntohs (dns->cfg.max_size) : MAX_PKT_SIZE) - offs;	895	int dlen = ntohs (dns->cfg.max_size) - offs;
		896
873	// bind doesn't compress well, so reduce further by one label length	897	// bind doesn't compress well, so reduce further by one label length
874	dlen -= qlen;	898	dlen -= qlen;
875		899
876	if (dns)
877	{
878	// only put data into in-order sequence packets, if	900	// only put data into in-order sequence packets, if
879	// we receive out-of-order packets we generate empty	901	// we receive out-of-order packets we generate empty
880	// replies	902	// replies
881	while (dlen > 1 && !dns->snddq.empty () && in_seq)	903	//printf ("%d - %d & %x (=%d) < %d\n", seqno, dns->repseq, SEQNO_MASK, (seqno - dns->repseq) & SEQNO_MASK, MAX_WINDOW);//D
		904	if (((seqno - dns->repseq) & SEQNO_MASK) <= MAX_WINDOW)
882	{	905	{
		906	dns->repseq = seqno;
		907
		908	while (dlen > 1 && !dns->snddq.empty ())
		909	{
883	int txtlen = dlen <= 255 ? dlen - 1 : 255;	910	int txtlen = dlen <= 255 ? dlen - 1 : 255;
884		911
885	if (txtlen > dns->snddq.size ())	912	if (txtlen > dns->snddq.size ())
886	txtlen = dns->snddq.size ();	913	txtlen = dns->snddq.size ();
887		914
888	pkt[offs++] = txtlen;	915	pkt[offs++] = txtlen;
889	memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);	916	memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
890	offs += txtlen;	917	offs += txtlen;
891	dns->snddq.remove (txtlen);	918	dns->snddq.remove (txtlen);
892		919
893	dlen -= txtlen + 1;	920	dlen -= txtlen + 1;
		921	}
894	}	922	}
895		923
896	// avoid empty TXT rdata	924	// avoid completely 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 * conf.dns_overlap_factor)
		1034	dns->send_interval = dns->min_latency * conf.dns_overlap_factor;
		1035
		1036	if (dns->send_interval < conf.dns_send_interval)
1006	dns->send_interval = latency;	1037	dns->send_interval = conf.dns_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 = ntohl (si.host);
		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;
1154
1155	dns->tw.trigger ();	1190	c->dns->tw.trigger ();
1156		1191
		1192	// always return true even if the buffer overflows
1157	return true;	1193	return true;
1158	}	1194	}
1159		1195
1160	void	1196	void
1161	connection::dnsv4_reset_connection ()	1197	connection::dnsv4_reset_connection ()
…		…
1187	if (!send)	1223	if (!send)
1188	{	1224	{
1189	send = r;	1225	send = r;
1190		1226
1191	r->retry++;	1227	r->retry++;
1192	r->timeout = NOW + (r->retry * last_latency * 8.);	1228	r->timeout = NOW + (r->retry * min_latency * conf.dns_timeout_factor);
1193		1229
1194	// the following code changes the query section a bit, forcing	1230	// the following code changes the query section a bit, forcing
1195	// the forwarder to generate a new request	1231	// the forwarder to generate a new request
1196	if (r->stdhdr)	1232	if (r->stdhdr)
1197	{	1233	{
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);	1234	//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);	1235	//encode_header ((char )r->pkt->at (6 2 + 1), THISNODE->id, r->seqno, r->retry);
1200	}	1236	}
1201	}	1237	}
1202	}	1238	}
1203	else	1239	else
1204	NEXT (r->timeout);	1240	NEXT (r->timeout);
1205	}	1241	}
1206		1242
1207	if (last_sent + send_interval <= NOW)
1208	{
1209	if (!send)	1243	if (!send)
		1244	{
		1245	// generate a new packet, if wise
		1246
		1247	if (!established)
1210	{	1248	{
1211	// generate a new packet, if wise	1249	if (vpn->dns_sndpq.empty ())
1212
1213	if (!established)
1214	{	1250	{
1215	if (vpn->dns_sndpq.empty ())
1216	{
1217	send = new dns_snd (this);	1251	send = new dns_snd (this);
1218		1252
1219	cfg.reset (THISNODE->id);	1253	cfg.reset (THISNODE->id);
1220	send->gen_syn_req (cfg);	1254	send->gen_syn_req ();
1221	}
1222	}	1255	}
1223	else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING	1256	}
		1257	else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding
1224	&& !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))	1258	&& !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
		1259	{
		1260	if (last_sent + send_interval <= NOW)
1225	{	1261	{
1226	if (!snddq.empty ())	1262	//printf ("sending data request etc.\n"); //D
		1263	if (!snddq.empty () \|\| last_received + 1. > NOW)
1227	{	1264	{
1228	poll_interval = send_interval;	1265	poll_interval = send_interval;
1229	NEXT (NOW + send_interval);	1266	NEXT (NOW + send_interval);
1230	}	1267	}
1231		1268
1232	send = new dns_snd (this);	1269	send = new dns_snd (this);
1233	send->gen_stream_req (sndseq, snddq);	1270	send->gen_stream_req (sndseq, snddq);
1234	send->timeout = NOW + last_latency * 8.;	1271	send->timeout = NOW + min_latency * conf.dns_timeout_factor;
1235		1272
1236	sndseq = (sndseq + 1) & SEQNO_MASK;	1273	sndseq = (sndseq + 1) & SEQNO_MASK;
1237	}	1274	}
1238		1275	else
1239	if (send)	1276	NEXT (last_sent + send_interval);
1240	vpn->dns_sndpq.push_back (send);
1241	}	1277	}
1242		1278
1243	if (send)	1279	if (send)
1244	{	1280	vpn->dns_sndpq.push_back (send);
		1281	}
		1282
		1283	if (send)
		1284	{
1245	last_sent = NOW;	1285	last_sent = NOW;
1246	sendto (vpn->dnsv4_fd,	1286	sendto (vpn->dnsv4_fd,
1247	send->pkt->at (0), send->pkt->len, 0,	1287	send->pkt->at (0), send->pkt->len, 0,
1248	vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());	1288	vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
1249	}
1250	}	1289	}
1251	else
1252	NEXT (last_sent + send_interval);
1253		1290
1254	slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d)",	1291	slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)",
1255	poll_interval, send_interval, next - NOW,	1292	poll_interval, send_interval, next - NOW,
1256	vpn->dns_sndpq.size (), snddq.size ());	1293	vpn->dns_sndpq.size (), snddq.size (),
		1294	rcvpq.size ());
1257		1295
1258	// TODO: no idea when this happens, but when next < NOW, we have a problem	1296	// TODO: no idea when this happens, but when next < NOW, we have a problem
		1297	// doesn't seem to happen anymore
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

Diff Legend

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

Comparing gvpe/src/vpn_dns.C (file contents): Revision 1.17 by pcg, Sat Mar 5 03:47:05 2005 UTC vs. Revision 1.37 by pcg, Wed Mar 23 17:03:58 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 1.37 by pcg, Wed Mar 23 17:03:58 2005 UTC