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

Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.13 by pcg, Fri Mar 4 09:48:42 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 is having 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 1.	52	#define INITIAL_TIMEOUT 0.1 // retry timeouts
53	#define INITIAL_SYN_TIMEOUT 2.	53	#define INITIAL_SYN_TIMEOUT 2. // retry timeout for initial syn
54		54
55	#define MIN_SEND_INTERVAL 0.01
56	#define MAX_SEND_INTERVAL 0.5 // optimistic?	55	#define MAX_SEND_INTERVAL 2. // optimistic?
57		56
58	#define MAX_OUTSTANDING 40 // max. outstanding requests
59	#define MAX_WINDOW 100 // max. for MAX_OUTSTANDING	57	#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog
60	#define MAX_BACKLOG (100*1024) // size of protocol backlog, 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 byte sless give room for one reply byte	62	// every request byte less give room for two reply bytes
65		63
66	#define SEQNO_MASK 0xffff	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
70	#define MAX_PKT_SIZE 512	68	#define MAX_PKT_SIZE 512
71		69
…		…
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)	268	inline void encode_header (char *data, int clientid, int seqno, int retry = 0)
271	{	269	{
272	u8 hdr[3] = { clientid, seqno >> 8, seqno };	270	seqno &= SEQNO_MASK;
		271
		272	u8 hdr[3] = {
		273	clientid,
		274	(seqno >> 8) \| (retry << 6),
		275	seqno,
		276	};
273		277
274	assert (clientid < 256);	278	assert (clientid < 256);
275		279
276	cdc26.encode (data, hdr, 3);	280	cdc26.encode (data, hdr, 3);
277	}	281	}
…		…
281	u8 hdr[3];	285	u8 hdr[3];
282		286
283	cdc26.decode (hdr, data, HDRSIZE);	287	cdc26.decode (hdr, data, HDRSIZE);
284		288
285	clientid = hdr[0];	289	clientid = hdr[0];
286	seqno = (hdr[1] << 8) \| hdr[2];	290	seqno = ((hdr[1] << 8) \| hdr[2]) & SEQNO_MASK;
287	}	291	}
288		292
289	/////////////////////////////////////////////////////////////////////////////	293	/////////////////////////////////////////////////////////////////////////////
290		294
291	struct byte_stream	295	struct byte_stream
…		…
320	}	324	}
321		325
322	void byte_stream::remove (int count)	326	void byte_stream::remove (int count)
323	{	327	{
324	if (count > fill)	328	if (count > fill)
325	abort ();	329	assert (count <= fill);
326		330
327	memmove (data, data + count, fill -= count);	331	memmove (data, data + count, fill -= count);
328	}	332	}
329		333
330	bool byte_stream::put (u8 *data, unsigned int datalen)	334	bool byte_stream::put (u8 *data, unsigned int datalen)
…		…
350	return true;	354	return true;
351	}	355	}
352		356
353	vpn_packet *byte_stream::get ()	357	vpn_packet *byte_stream::get ()
354	{	358	{
		359	unsigned int len;
		360
		361	for (;;)
		362	{
355	unsigned int len = (data [0] << 8) \| data [1];	363	len = (data [0] << 8) \| data [1];
356		364
357	if (len > MAXSIZE && fill >= 2)	365	if (len <= MAXSIZE \|\| fill < 2)
358	abort (); // TODO handle this gracefully, connection reset	366	break;
359		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
360	if (fill < len + 2)	373	if (fill < len + 2)
361	return 0;	374	return 0;
362		375
363	vpn_packet *pkt = new vpn_packet;	376	vpn_packet *pkt = new vpn_packet;
364		377
…		…
393	struct dns_cfg	406	struct dns_cfg
394	{	407	{
395	static int next_uid;	408	static int next_uid;
396		409
397	u8 id1, id2, id3, id4;	410	u8 id1, id2, id3, id4;
		411
398	u8 version;	412	u8 version;
		413	u8 flags;
399	u8 rrtype;	414	u8 rrtype;
400	u8 flags;
401	u8 def_ttl;	415	u8 def_ttl;
402	u8 rcv_cdc;	416
403	u8 snd_cdc;
404	u16 max_size;
405	u16 client;	417	u16 client;
406	u16 uid; // to make request unique	418	u16 uid; // to make request unique
407		419
408	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;
409		429
410	void reset (int clientid);	430	void reset (int clientid);
411	bool valid ();	431	bool valid ();
412	};	432	};
413		433
…		…
423	version = 1;	443	version = 1;
424		444
425	rrtype = RR_TYPE_TXT;	445	rrtype = RR_TYPE_TXT;
426	flags = 0;	446	flags = 0;
427	def_ttl = 0;	447	def_ttl = 0;
		448	seq_cdc = 26;
		449	req_cdc = 62;
428	rcv_cdc = 0;	450	rep_cdc = 0;
429	snd_cdc = 62;
430	max_size = ntohs (MAX_PKT_SIZE);	451	max_size = htons (MAX_PKT_SIZE);
431	client = ntohs (clientid);	452	client = htons (clientid);
432	uid = next_uid++;	453	uid = next_uid++;
		454	delay = 0;
433		455
434	memset (reserved, 0, 8);	456	r3 = r4 = 0;
		457	r4 = r5 = r6 = r7 = 0;
435	}	458	}
436		459
437	bool dns_cfg::valid ()	460	bool dns_cfg::valid ()
438	{	461	{
439	return id1 == 'G'	462	return id1 == 'G'
440	&& id2 == 'V'	463	&& id2 == 'V'
441	&& id3 == 'P'	464	&& id3 == 'P'
442	&& id4 == 'E'	465	&& id4 == 'E'
		466	&& seq_cdc == 26
		467	&& req_cdc == 62
		468	&& rep_cdc == 0
443	&& version == 1	469	&& version == 1;
444	&& flags == 0
445	&& rcv_cdc == 0
446	&& snd_cdc == 62
447	&& max_size == ntohs (MAX_PKT_SIZE);
448	}	470	}
449		471
450	struct dns_packet : net_packet	472	struct dns_packet : net_packet
451	{	473	{
452	u16 id;	474	u16 id;
453	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
454	u16 qdcount, ancount, nscount, arcount;	476	u16 qdcount, ancount, nscount, arcount;
455		477
456	u8 data[MAXSIZE - 6 * 2];	478	u8 data [MAXSIZE - 6 * 2];
457		479
458	int decode_label (char *data, int size, int &offs);	480	int decode_label (char *data, int size, int &offs);
459	};	481	};
460		482
461	int dns_packet::decode_label (char *data, int size, int &offs)	483	int dns_packet::decode_label (char *data, int size, int &offs)
…		…
492	return data - orig;	514	return data - orig;
493	}	515	}
494		516
495	/////////////////////////////////////////////////////////////////////////////	517	/////////////////////////////////////////////////////////////////////////////
496		518
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	519	static u16 dns_id = 0; // TODO: should be per-vpn
513		520
514	static u16 next_id ()	521	static u16 next_id ()
515	{	522	{
		523	if (!dns_id)
		524	dns_id = time (0);
		525
516	// the simplest lsfr with periodicity 65535 i could find	526	// the simplest lsfr with periodicity 65535 i could find
517	dns_id = (dns_id << 1)	527	dns_id = (dns_id << 1)
518	\| (((dns_id >> 1)	528	\| (((dns_id >> 1)
519	^ (dns_id >> 2)	529	^ (dns_id >> 2)
520	^ (dns_id >> 4)	530	^ (dns_id >> 4)
521	^ (dns_id >> 15)) & 1);	531	^ (dns_id >> 15)) & 1);
522		532
523	return dns_id;	533	return dns_id;
524	}	534	}
525		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
		565	struct dns_snd
		566	{
		567	dns_packet *pkt;
		568	tstamp timeout, sent;
		569	int retry;
		570	struct dns_connection *dns;
		571	int seqno;
		572	bool stdhdr;
		573
		574	void gen_stream_req (int seqno, byte_stream &stream);
		575	void gen_syn_req ();
		576
		577	dns_snd (dns_connection *dns);
		578	~dns_snd ();
		579	};
		580
526	dns_snd::dns_snd (dns_connection *dns)	581	dns_snd::dns_snd (dns_connection *dns)
527	: dns (dns)	582	: dns (dns)
528	{	583	{
529	timeout = 0;	584	timeout = 0;
530	retry = 0;	585	retry = 0;
531	seqno = 0;	586	seqno = 0;
532	sent = NOW;	587	sent = NOW;
		588	stdhdr = false;
533		589
534	pkt = new dns_packet;	590	pkt = new dns_packet;
535		591
536	pkt->id = next_id ();	592	pkt->id = next_id ();
537	}	593	}
…		…
564	}	620	}
565	}	621	}
566		622
567	void dns_snd::gen_stream_req (int seqno, byte_stream &stream)	623	void dns_snd::gen_stream_req (int seqno, byte_stream &stream)
568	{	624	{
		625	stdhdr = true;
569	this->seqno = seqno;	626	this->seqno = seqno;
570		627
571	timeout = NOW + INITIAL_TIMEOUT;	628	timeout = NOW + INITIAL_TIMEOUT;
572		629
573	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);	630	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
574	pkt->qdcount = htons (1);	631	pkt->qdcount = htons (1);
575		632
576	int offs = 6*2;	633	int offs = 6*2;
577	int dlen = MAX_DOMAIN_SIZE - (strlen (THISNODE->domain) + 2);	634	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,	635	// 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	636	// so we need to have space for 2*MAX_DOMAIN_SIZE + header + extra
580		637
581	char enc[256], *encp = enc;	638	char enc[256], *encp = enc;
582	encode_header (enc, THISNODE->id, seqno);	639	encode_header (enc, THISNODE->id, seqno);
…		…
600	encp += lbllen;	657	encp += lbllen;
601		658
602	enclen -= lbllen;	659	enclen -= lbllen;
603	}	660	}
604		661
605	append_domain (*pkt, offs, THISNODE->domain);	662	append_domain (*pkt, offs, dns->c->conf->domain);
606		663
607	(*pkt)[offs++] = 0;	664	(*pkt)[offs++] = 0;
608	(pkt)[offs++] = RR_TYPE_ANY >> 8; (pkt)[offs++] = RR_TYPE_ANY;	665	(pkt)[offs++] = RR_TYPE_ANY >> 8; (pkt)[offs++] = RR_TYPE_ANY;
609	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;	666	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;
610		667
611	pkt->len = offs;	668	pkt->len = offs;
612	}	669	}
613		670
614	void dns_snd::gen_syn_req (const dns_cfg &cfg)	671	void dns_snd::gen_syn_req ()
615	{	672	{
616	timeout = NOW + INITIAL_SYN_TIMEOUT;	673	timeout = NOW + INITIAL_SYN_TIMEOUT;
617		674
618	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);	675	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
619	pkt->qdcount = htons (1);	676	pkt->qdcount = htons (1);
620		677
621	int offs = 6*2;	678	int offs = 6 * 2;
622		679
623	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));
624		681
625	assert (elen <= MAX_LBL_SIZE);	682	assert (elen <= MAX_LBL_SIZE);
626		683
627	(*pkt)[offs] = elen;	684	(*pkt)[offs] = elen;
628	offs += elen + 1;	685	offs += elen + 1;
629	append_domain (*pkt, offs, THISNODE->domain);	686	append_domain (*pkt, offs, dns->c->conf->domain);
630		687
631	(*pkt)[offs++] = 0;	688	(*pkt)[offs++] = 0;
632	(pkt)[offs++] = RR_TYPE_A >> 8; (pkt)[offs++] = RR_TYPE_A;	689	(pkt)[offs++] = RR_TYPE_A >> 8; (pkt)[offs++] = RR_TYPE_A;
633	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;	690	(pkt)[offs++] = RR_CLASS_IN >> 8; (pkt)[offs++] = RR_CLASS_IN;
634		691
…		…
657	delete pkt;	714	delete pkt;
658	}	715	}
659		716
660	/////////////////////////////////////////////////////////////////////////////	717	/////////////////////////////////////////////////////////////////////////////
661		718
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)	719	dns_connection::dns_connection (connection *c)
688	: c (c)	720	: c (c)
689	, rcvdq (MAX_BACKLOG * 2)	721	, rcvdq (MAX_BACKLOG * 2)
690	, snddq (MAX_BACKLOG * 2)	722	, snddq (MAX_BACKLOG)
691	, tw (this, &dns_connection::time_cb)	723	, tw (this, &dns_connection::time_cb)
692	{	724	{
693	vpn = c->vpn;	725	vpn = c->vpn;
694		726
695	established = false;	727	established = false;
696		728
697	rcvseq = sndseq = 0;	729	rcvseq = repseq = sndseq = 0;
698		730
699	last_sent = last_received = 0;	731	last_sent = last_received = 0;
700	poll_interval = MIN_POLL_INTERVAL;	732	poll_interval = 0.5; // starting here
701	send_interval = 0.2; // starting rate	733	send_interval = 0.5; // starting rate
		734	min_latency = INITIAL_TIMEOUT;
702	}	735	}
703		736
704	dns_connection::~dns_connection ()	737	dns_connection::~dns_connection ()
705	{	738	{
706	for (vector<dns_rcv *>::iterator i = rcvpq.begin ();	739	for (vector<dns_rcv *>::iterator i = rcvpq.begin ();
…		…
718		751
719	poll_interval = send_interval;	752	poll_interval = send_interval;
720	}	753	}
721	else	754	else
722	{	755	{
723	poll_interval *= 1.1;	756	poll_interval *= 1.5;
		757
724	if (poll_interval > MAX_POLL_INTERVAL)	758	if (poll_interval > MAX_POLL_INTERVAL)
725	poll_interval = MAX_POLL_INTERVAL;	759	poll_interval = MAX_POLL_INTERVAL;
726	}	760	}
727		761
728	rcvpq.push_back (r);	762	rcvpq.push_back (r);
…		…
746	}	780	}
747		781
748	rcvseq = (rcvseq + 1) & SEQNO_MASK;	782	rcvseq = (rcvseq + 1) & SEQNO_MASK;
749		783
750	if (!rcvdq.put (r->data, r->datalen))	784	if (!rcvdq.put (r->data, r->datalen))
		785	{
		786	slog (L_ERR, "DNS: !rcvdq.put (r->data, r->datalen)");
751	abort (); // MUST never overflow, can be caused by data corruption, TODO	787	abort (); // MUST never overflow, can be caused by data corruption, TODO
		788	}
752		789
753	while (vpn_packet *pkt = rcvdq.get ())	790	while (vpn_packet *pkt = rcvdq.get ())
754	{	791	{
755	sockinfo si;	792	sockinfo si;
756	si.host = 0; si.port = 0; si.prot = PROT_DNSv4;	793	si.host = htonl (c->conf->id); si.port = 0; si.prot = PROT_DNSv4;
757		794
758	vpn->recv_vpn_packet (pkt, si);	795	vpn->recv_vpn_packet (pkt, si);
759		796
760	delete pkt;	797	delete pkt;
761	}	798	}
…		…
775	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);	812	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);
776		813
777	if (0 == (flags & (FLAG_RESPONSE \| FLAG_OP_MASK))	814	if (0 == (flags & (FLAG_RESPONSE \| FLAG_OP_MASK))
778	&& pkt.qdcount == htons (1))	815	&& pkt.qdcount == htons (1))
779	{	816	{
780	char qname[MAXSIZE];	817	char qname [MAXSIZE];
781	int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);	818	int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
782		819
783	u16 qtype = pkt [offs++] << 8; qtype \|= pkt [offs++];	820	u16 qtype = pkt [offs++] << 8; qtype \|= pkt [offs++];
784	u16 qclass = pkt [offs++] << 8; qclass \|= pkt [offs++];	821	u16 qclass = pkt [offs++] << 8; qclass \|= pkt [offs++];
785		822
786	pkt.qdcount = htons (1);	823	pkt.qdcount = htons (1);
787	pkt.ancount = 0;	824	pkt.ancount = 0;
788	pkt.nscount = 0; // should be self, as other nameservers reply like this	825	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	826	pkt.arcount = 0; // a record for self, as other nameservers reply like this
790		827
791	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_NXDOMAIN);	828	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_SERVFAIL);
792		829
793	int dlen = strlen (THISNODE->domain);	830	int dlen = strlen (THISNODE->domain);
794		831
795	if (qclass == RR_CLASS_IN	832	if (qclass == RR_CLASS_IN
796	&& qlen > dlen + 1	833	&& qlen > dlen + 1
797	&& !memcmp (qname + qlen - dlen - 1, THISNODE->domain, dlen))	834	&& !memcmp (qname + qlen - (dlen + 1), THISNODE->domain, dlen))
798	{	835	{
799	// now generate reply	836	// now generate reply
800	pkt.ancount = htons (1); // one answer RR	837	pkt.ancount = htons (1); // one answer RR
801	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_OK);	838	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_OK);
802		839
…		…
824	if (SEQNO_EQ ((*i)->seqno, seqno))	861	if (SEQNO_EQ ((*i)->seqno, seqno))
825	{	862	{
826	// already seen that request: simply reply with the cached reply	863	// already seen that request: simply reply with the cached reply
827	dns_rcv r = i;	864	dns_rcv r = i;
828		865
829	printf ("DUPLICATE %d\n", htons (r->pkt->id));//D	866	slog (L_DEBUG, "DNS: duplicate packet received ID %d, SEQ %d", htons (r->pkt->id), seqno);
		867
		868	// refresh header & id, as the retry count could have changed
		869	memcpy (r->pkt->at (6 * 2 + 1), pkt.at (6 * 2 + 1), HDRSIZE);
		870	r->pkt->id = pkt.id;
830		871
831	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);
832	pkt.id = r->pkt->id;	873
833	goto duplicate_request;	874	goto duplicate_request;
834	}	875	}
835		876
836	// new packet, queue	877	// new packet, queue
837	rcv = new dns_rcv (seqno, data, datalen);	878	rcv = new dns_rcv (seqno, data, datalen);
838	dns->receive_rep (rcv);	879	dns->receive_rep (rcv);
839	}	880	}
840		881
		882	{
841	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
842		884
843	int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A;	885	int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A;
844	pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type	886	pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type
845	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
846	pkt [offs++] = 0; pkt [offs++] = 0;	888	pkt [offs++] = 0; pkt [offs++] = 0;
847	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
848		890
849	int rdlen_offs = offs += 2;	891	int rdlen_offs = offs += 2;
850		892
		893	if (dns)
		894	{
851	int dlen = (dns ? ntohs (dns->cfg.max_size) : MAX_PKT_SIZE) - offs;	895	int dlen = ntohs (dns->cfg.max_size) - offs;
		896
852	// 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
853	dlen -= qlen;	898	dlen -= qlen;
854		899
855	if (dns)	900	// only put data into in-order sequence packets, if
856	{	901	// we receive out-of-order packets we generate empty
857	while (dlen > 1 && !dns->snddq.empty ())	902	// replies
		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)
858	{	905	{
		906	dns->repseq = seqno;
		907
		908	while (dlen > 1 && !dns->snddq.empty ())
		909	{
859	int txtlen = dlen <= 255 ? dlen - 1 : 255;	910	int txtlen = dlen <= 255 ? dlen - 1 : 255;
860		911
861	if (txtlen > dns->snddq.size ())	912	if (txtlen > dns->snddq.size ())
862	txtlen = dns->snddq.size ();	913	txtlen = dns->snddq.size ();
863		914
864	pkt[offs++] = txtlen;	915	pkt[offs++] = txtlen;
865	memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);	916	memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
866	offs += txtlen;	917	offs += txtlen;
867	dns->snddq.remove (txtlen);	918	dns->snddq.remove (txtlen);
868		919
869	dlen -= txtlen + 1;	920	dlen -= txtlen + 1;
		921	}
870	}	922	}
871		923
872	// avoid empty TXT rdata	924	// avoid completely empty TXT rdata
873	if (offs == rdlen_offs)	925	if (offs == rdlen_offs)
874	pkt[offs++] = 0;	926	pkt[offs++] = 0;
		927
		928	slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
875	}	929	}
876	else	930	else
877	{	931	{
878	// send RST	932	// send RST
879	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;
880	pkt [offs++] = CMD_IP_RST;	934	pkt [offs++] = CMD_IP_RST;
881	}	935	}
882		936
883	int rdlen = offs - rdlen_offs;	937	int rdlen = offs - rdlen_offs;
884		938
885	pkt [rdlen_offs - 2] = rdlen >> 8;	939	pkt [rdlen_offs - 2] = rdlen >> 8;
886	pkt [rdlen_offs - 1] = rdlen;	940	pkt [rdlen_offs - 1] = rdlen;
887		941
888	if (dns)	942	if (dns)
889	{	943	{
890	// now update dns_rcv copy	944	// now update dns_rcv copy
891	rcv->pkt->len = offs;	945	rcv->pkt->len = offs;
892	memcpy (rcv->pkt->at (0), pkt.at (0), offs);	946	memcpy (rcv->pkt->at (0), pkt.at (0), offs);
893	}	947	}
		948	}
894		949
895	duplicate_request: ;	950	duplicate_request: ;
896	}	951	}
897	else	952	else
898	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);	953	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);
…		…
910	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
911	pkt [offs++] = 0; pkt [offs++] = 0;	966	pkt [offs++] = 0; pkt [offs++] = 0;
912	pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL	967	pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL
913	pkt [offs++] = 0; pkt [offs++] = 4; // rdlength	968	pkt [offs++] = 0; pkt [offs++] = 4; // rdlength
914		969
915	slog (L_INFO, _("DNS tunnel: client %d tries to connect"), client);	970	slog (L_INFO, _("DNS: client %d connects"), client);
916		971
917	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;
918	pkt [offs++] = CMD_IP_REJ;	973	pkt [offs++] = CMD_IP_REJ;
919		974
920	if (0 < client && client <= conns.size ())	975	if (0 < client && client <= conns.size ())
…		…
957	int seqno = (*i)->seqno;	1012	int seqno = (*i)->seqno;
958	u8 data[MAXSIZE], *datap = data;	1013	u8 data[MAXSIZE], *datap = data;
959		1014
960	if ((*i)->retry)	1015	if ((*i)->retry)
961	{	1016	{
962	dns->send_interval *= 1.001;	1017	dns->send_interval *= 1.01;
963	if (dns->send_interval > MAX_SEND_INTERVAL)	1018	if (dns->send_interval > MAX_SEND_INTERVAL)
964	dns->send_interval = MAX_SEND_INTERVAL;	1019	dns->send_interval = MAX_SEND_INTERVAL;
965	}	1020	}
966	else	1021	else
967	{	1022	{
968	#if 1	1023	#if 0
969	dns->send_interval *= 0.9999;	1024	dns->send_interval *= 0.999;
970	#endif	1025	#endif
971	if (dns->send_interval < MIN_SEND_INTERVAL)
972	dns->send_interval = MIN_SEND_INTERVAL;
973
974	// the latency surely puts an upper bound on	1026	// the latency surely puts an upper bound on
975	// the minimum send interval	1027	// the minimum send interval
976	double latency = NOW - (*i)->sent;	1028	double latency = NOW - (*i)->sent;
977		1029
978	if (dns->send_interval > latency)	1030	if (latency < dns->min_latency)
979	dns->send_interval = latency;	1031	dns->min_latency = latency;
		1032
		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)
		1037	dns->send_interval = conf.dns_send_interval;
980	}	1038	}
981		1039
982	delete *i;	1040	delete *i;
983	dns_sndpq.erase (i);	1041	dns_sndpq.erase (i);
984		1042
…		…
1034		1092
1035	if (ip [0] == CMD_IP_1	1093	if (ip [0] == CMD_IP_1
1036	&& ip [1] == CMD_IP_2	1094	&& ip [1] == CMD_IP_2
1037	&& ip [2] == CMD_IP_3)	1095	&& ip [2] == CMD_IP_3)
1038	{	1096	{
1039	slog (L_TRACE, _("got tunnel meta command %02x"), ip [3]);	1097	slog (L_TRACE, _("DNS: got tunnel meta command %02x"), ip [3]);
1040		1098
1041	if (ip [3] == CMD_IP_RST)	1099	if (ip [3] == CMD_IP_RST)
1042	{	1100	{
1043	slog (L_DEBUG, _("got tunnel RST request"));	1101	slog (L_DEBUG, _("DNS: got tunnel RST request"));
1044		1102
1045	delete dns; c->dns = 0;	1103	delete dns; c->dns = 0;
1046		1104
1047	return;	1105	return;
1048	}	1106	}
1049	else if (ip [3] == CMD_IP_SYN)	1107	else if (ip [3] == CMD_IP_SYN)
1050	{	1108	{
1051	slog (L_DEBUG, _("got tunnel SYN reply, server likes us."));	1109	slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us."));
1052	dns->established = true;	1110	dns->established = true;
1053	}	1111	}
1054	else if (ip [3] == CMD_IP_REJ)	1112	else if (ip [3] == CMD_IP_REJ)
1055	{	1113	{
1056	slog (L_DEBUG, _("got tunnel REJ reply, server does not like us, aborting."));	1114	slog (L_DEBUG, _("DNS: got tunnel REJ reply, server does not like us, aborting."));
1057	abort ();	1115	abort ();
1058	}	1116	}
1059	else	1117	else
1060	slog (L_INFO, _("got unknown meta command %02x"), ip [3]);	1118	slog (L_INFO, _("DNS: got unknown meta command %02x"), ip [3]);
1061	}	1119	}
1062	else	1120	else
1063	slog (L_INFO, _("got spurious a record %d.%d.%d.%d"),	1121	slog (L_INFO, _("DNS: got spurious a record %d.%d.%d.%d"),
1064	ip [0], ip [1], ip [2], ip [3]);	1122	ip [0], ip [1], ip [2], ip [3]);
1065		1123
1066	return;	1124	return;
1067	}	1125	}
1068		1126
1069	int client, rseqno;	1127	int client, rseqno;
1070	decode_header (qname, client, rseqno);	1128	decode_header (qname, client, rseqno);
1071		1129
1072	if (client != THISNODE->id)	1130	if (client != THISNODE->id)
1073	{	1131	{
1074	slog (L_INFO, _("got dns tunnel response with wrong clientid, ignoring"));	1132	slog (L_INFO, _("DNS: got dns tunnel response with wrong clientid, ignoring"));
1075	datap = 0;	1133	datap = 0;
1076	}	1134	}
1077	else if (rseqno != seqno)	1135	else if (rseqno != seqno)
1078	{	1136	{
1079	slog (L_DEBUG, _("got dns tunnel response with wrong seqno, badly caching nameserver?"));	1137	slog (L_DEBUG, _("DNS: got dns tunnel response with wrong seqno, badly caching nameserver?"));
1080	datap = 0;	1138	datap = 0;
1081	}	1139	}
1082	}	1140	}
1083	}	1141	}
1084		1142
…		…
1101		1159
1102	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);
1103		1161
1104	if (pkt->len > 0)	1162	if (pkt->len > 0)
1105	{	1163	{
1106	if (THISNODE->dns_port)	1164	if (ntohs (pkt->flags) & FLAG_RESPONSE)
		1165	dnsv4_client (*pkt);
		1166	else
1107	{	1167	{
1108	dnsv4_server (*pkt);	1168	dnsv4_server (*pkt);
1109	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);
1110	}	1170	}
1111	else
1112	dnsv4_client (*pkt);
1113		1171
1114	delete pkt;	1172	delete pkt;
1115	}	1173	}
1116	}	1174	}
1117	}	1175	}
1118		1176
1119	bool	1177	bool
1120	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)
1121	{	1179	{
		1180	int client = ntohl (si.host);
		1181
		1182	assert (0 < client && client <= conns.size ());
		1183
		1184	connection *c = conns [client - 1];
		1185
1122	if (!dns)	1186	if (!c->dns)
1123	dns = new dns_connection (this);	1187	c->dns = new dns_connection (c);
1124		1188
1125	if (!dns->snddq.put (pkt))	1189	if (c->dns->snddq.put (pkt))
1126	return false;
1127
1128	dns->tw.trigger ();	1190	c->dns->tw.trigger ();
1129		1191
		1192	// always return true even if the buffer overflows
1130	return true;	1193	return true;
1131	}	1194	}
1132		1195
1133	void	1196	void
1134	connection::dnsv4_reset_connection ()	1197	connection::dnsv4_reset_connection ()
…		…
1160	if (!send)	1223	if (!send)
1161	{	1224	{
1162	send = r;	1225	send = r;
1163		1226
1164	r->retry++;	1227	r->retry++;
1165	r->timeout = NOW + r->retry;	1228	r->timeout = NOW + (r->retry * min_latency * conf.dns_timeout_factor);
		1229
		1230	// the following code changes the query section a bit, forcing
		1231	// the forwarder to generate a new request
		1232	if (r->stdhdr)
		1233	{
		1234	//printf ("reencoded header for ID %d retry %d:%d:%d (%p)\n", htons (r->pkt->id), THISNODE->id, r->seqno, r->retry);
		1235	//encode_header ((char )r->pkt->at (6 2 + 1), THISNODE->id, r->seqno, r->retry);
		1236	}
1166	}	1237	}
1167	}	1238	}
1168	else	1239	else
1169	NEXT (r->timeout);	1240	NEXT (r->timeout);
1170	}	1241	}
1171		1242
1172	if (last_sent + send_interval <= NOW)
1173	{
1174	if (!send)	1243	if (!send)
		1244	{
		1245	// generate a new packet, if wise
		1246
		1247	if (!established)
1175	{	1248	{
1176	// generate a new packet, if wise
1177
1178	if (!established)
1179	{
1180	if (vpn->dns_sndpq.empty ())	1249	if (vpn->dns_sndpq.empty ())
1181	{
1182	send = new dns_snd (this);
1183
1184	cfg.reset (THISNODE->id);
1185	send->gen_syn_req (cfg);
1186	}
1187	}
1188	else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING)
1189	{	1250	{
1190	send = new dns_snd (this);	1251	send = new dns_snd (this);
		1252
		1253	cfg.reset (THISNODE->id);
		1254	send->gen_syn_req ();
		1255	}
		1256	}
		1257	else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding
		1258	&& !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
		1259	{
		1260	if (last_sent + send_interval <= NOW)
		1261	{
		1262	//printf ("sending data request etc.\n"); //D
		1263	if (!snddq.empty () \|\| last_received + 1. > NOW)
		1264	{
		1265	poll_interval = send_interval;
		1266	NEXT (NOW + send_interval);
		1267	}
		1268
		1269	send = new dns_snd (this);
1191	send->gen_stream_req (sndseq, snddq);	1270	send->gen_stream_req (sndseq, snddq);
		1271	send->timeout = NOW + min_latency * conf.dns_timeout_factor;
1192		1272
1193	sndseq = (sndseq + 1) & SEQNO_MASK;	1273	sndseq = (sndseq + 1) & SEQNO_MASK;
1194	}	1274	}
1195		1275	else
1196	if (send)	1276	NEXT (last_sent + send_interval);
1197	vpn->dns_sndpq.push_back (send);
1198	}	1277	}
1199		1278
1200	if (send)	1279	if (send)
1201	{	1280	vpn->dns_sndpq.push_back (send);
		1281	}
		1282
		1283	if (send)
		1284	{
1202	last_sent = NOW;	1285	last_sent = NOW;
1203	sendto (vpn->dnsv4_fd,	1286	sendto (vpn->dnsv4_fd,
1204	send->pkt->at (0), send->pkt->len, 0,	1287	send->pkt->at (0), send->pkt->len, 0,
1205	vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());	1288	vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
1206	}
1207	}	1289	}
1208	else
1209	NEXT (last_sent + send_interval);
1210		1290
1211	slog (L_NOISE, "pi %f si %f N %f (%d:%d)",	1291	slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)",
1212	poll_interval, send_interval, next - NOW,	1292	poll_interval, send_interval, next - NOW,
1213	vpn->dns_sndpq.size (), snddq.size ());	1293	vpn->dns_sndpq.size (), snddq.size (),
		1294	rcvpq.size ());
1214		1295
1215	// 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
1216	if (next < NOW + 0.0001)	1298	if (next < NOW + 0.001)
1217	next = NOW + 0.1;	1299	next = NOW + 0.1;
1218		1300
1219	w.start (next);	1301	w.start (next);
1220	}	1302	}
1221		1303

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Comparing gvpe/src/vpn_dns.C (file contents): Revision 1.13 by pcg, Fri Mar 4 09:48:42 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 1.13 by pcg, Fri Mar 4 09:48:42 2005 UTC vs.
Revision 1.37 by pcg, Wed Mar 23 17:03:58 2005 UTC