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

Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.20 by pcg, Sun Mar 6 21:32:15 2005 UTC vs.
Revision 1.42 by pcg, Sat Nov 10 05:14:22 2007 UTC

…		…
14	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the	14	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15	GNU General Public License for more details.	15	GNU General Public License for more details.
16		16
17	You should have received a copy of the GNU General Public License	17	You should have received a copy of the GNU General Public License
18	along with gvpe; if not, write to the Free Software	18	along with gvpe; if not, write to the Free Software
19	Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA	19	Foundation, Inc. 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20	*/	20	*/
		21
		22	// TODO: EDNS0 option to increase dns mtu?
		23	// TODO: re-write dns packet parsing/creation using a safe mem-buffer
		24	// to ensure no buffer overflows or similar problems.
21		25
22	#include "config.h"	26	#include "config.h"
23		27
24	#if ENABLE_DNS	28	#if ENABLE_DNS
25		29
…		…
44		48
45	#include "netcompat.h"	49	#include "netcompat.h"
46		50
47	#include "vpn.h"	51	#include "vpn.h"
48		52
49	#define MIN_POLL_INTERVAL .02 // how often to poll minimally when the server has data
50	#define MAX_POLL_INTERVAL 6. // how often to poll minimally when the server has no data	53	#define MAX_POLL_INTERVAL 5. // how often to poll minimally when the server has no data
51	#define ACTIVITY_INTERVAL 5.	54	#define ACTIVITY_INTERVAL 5.
52		55
53	#define INITIAL_TIMEOUT 0.1 // retry timeouts	56	#define INITIAL_TIMEOUT 0.1 // retry timeouts
54	#define INITIAL_SYN_TIMEOUT 10. // retry timeout for initial syn	57	#define INITIAL_SYN_TIMEOUT 2. // retry timeout for initial syn
55		58
56	#define MIN_SEND_INTERVAL 0.01 // wait at least this time between sending requests
57	#define MAX_SEND_INTERVAL 0.5 // optimistic?	59	#define MAX_SEND_INTERVAL 2. // optimistic?
58		60
59	#define MAX_OUTSTANDING 10 // max. outstanding requests
60	#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog	61	#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog
61	#define MAX_BACKLOG (100*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE	62	#define MAX_BACKLOG (64*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE
62		63
63	#define MAX_DOMAIN_SIZE 220 // 255 is legal limit, but bind doesn't compress well	64	#define MAX_DOMAIN_SIZE 240 // 255 is legal limit, but bind doesn't compress well
64	// 240 leaves about 4 bytes of server reply data	65	// 240 leaves about 4 bytes of server reply data
65	// every two request bytes less give room for one reply byte	66	// every request byte less give room for two reply bytes
66		67
67	#define SEQNO_MASK 0x3fff	68	#define SEQNO_MASK 0x3fff
68	#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )	69	#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )
69		70
70	#define MAX_LBL_SIZE 63	71	#define MAX_LBL_SIZE 63
…		…
265	static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO");	266	static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO");
266		267
267	/////////////////////////////////////////////////////////////////////////////	268	/////////////////////////////////////////////////////////////////////////////
268		269
269	#define HDRSIZE 6	270	#define HDRSIZE 6
270		271
271	inline void encode_header (char *data, int clientid, int seqno, int retry = 0)	272	inline void encode_header (char *data, int clientid, int seqno, int retry = 0)
272	{	273	{
273	seqno &= SEQNO_MASK;	274	seqno &= SEQNO_MASK;
274		275
275	u8 hdr[3] = {	276	u8 hdr[3] = {
…		…
409	struct dns_cfg	410	struct dns_cfg
410	{	411	{
411	static int next_uid;	412	static int next_uid;
412		413
413	u8 id1, id2, id3, id4;	414	u8 id1, id2, id3, id4;
		415
414	u8 version;	416	u8 version;
		417	u8 flags;
415	u8 rrtype;	418	u8 rrtype;
416	u8 flags;
417	u8 def_ttl;	419	u8 def_ttl;
418	u8 rcv_cdc;	420
419	u8 snd_cdc;
420	u16 max_size;
421	u16 client;	421	u16 client;
422	u16 uid; // to make request unique	422	u16 uid; // to make request unique
423		423
424	u8 reserved[8];	424	u16 max_size;
		425	u8 seq_cdc;
		426	u8 req_cdc;
		427
		428	u8 rep_cdc;
		429	u8 delay; // time in 0.01s units that the server may delay replying packets
		430	u8 r3, r4;
		431
		432	u8 r5, r6, r7, r8;
425		433
426	void reset (int clientid);	434	void reset (int clientid);
427	bool valid ();	435	bool valid ();
428	};	436	};
429		437
…		…
438		446
439	version = 1;	447	version = 1;
440		448
441	rrtype = RR_TYPE_TXT;	449	rrtype = RR_TYPE_TXT;
442	flags = 0;	450	flags = 0;
443	def_ttl = 1;	451	def_ttl = 0;
		452	seq_cdc = 26;
		453	req_cdc = 62;
444	rcv_cdc = 0;	454	rep_cdc = 0;
445	snd_cdc = 62;
446	max_size = ntohs (MAX_PKT_SIZE);	455	max_size = htons (MAX_PKT_SIZE);
447	client = ntohs (clientid);	456	client = htons (clientid);
448	uid = next_uid++;	457	uid = next_uid++;
		458	delay = 0;
449		459
450	memset (reserved, 0, 8);	460	r3 = r4 = 0;
		461	r4 = r5 = r6 = r7 = 0;
451	}	462	}
452		463
453	bool dns_cfg::valid ()	464	bool dns_cfg::valid ()
454	{	465	{
		466	// although the protocol itself allows for some configurability,
		467	// only the following encoding/decoding settings are implemented.
455	return id1 == 'G'	468	return id1 == 'G'
456	&& id2 == 'V'	469	&& id2 == 'V'
457	&& id3 == 'P'	470	&& id3 == 'P'
458	&& id4 == 'E'	471	&& id4 == 'E'
		472	&& seq_cdc == 26
		473	&& req_cdc == 62
		474	&& rep_cdc == 0
459	&& version == 1	475	&& version == 1;
460	&& flags == 0
461	&& rcv_cdc == 0
462	&& snd_cdc == 62
463	&& max_size == ntohs (MAX_PKT_SIZE);
464	}	476	}
465		477
466	struct dns_packet : net_packet	478	struct dns_packet : net_packet
467	{	479	{
468	u16 id;	480	u16 id;
469	u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4	481	u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4
470	u16 qdcount, ancount, nscount, arcount;	482	u16 qdcount, ancount, nscount, arcount;
471		483
472	u8 data[MAXSIZE - 6 * 2];	484	u8 data [MAXSIZE - 6 * 2];
473		485
474	int decode_label (char *data, int size, int &offs);	486	int decode_label (char *data, int size, int &offs);
475	};	487	};
476		488
477	int dns_packet::decode_label (char *data, int size, int &offs)	489	int dns_packet::decode_label (char *data, int size, int &offs)
…		…
539		551
540	bool established;	552	bool established;
541		553
542	tstamp last_received;	554	tstamp last_received;
543	tstamp last_sent;	555	tstamp last_sent;
544	double last_latency;	556	double min_latency;
545	double poll_interval, send_interval;	557	double poll_interval, send_interval;
546		558
547	vector<dns_rcv *> rcvpq;	559	vector<dns_rcv *> rcvpq;
548		560
549	byte_stream rcvdq; int rcvseq;	561	byte_stream rcvdq; int rcvseq; int repseq;
550	byte_stream snddq; int sndseq;	562	byte_stream snddq; int sndseq;
551		563
552	void time_cb (time_watcher &w); time_watcher tw;	564	void time_cb (ev::timer &w, int revents); ev::timer tw;
553	void receive_rep (dns_rcv *r);	565	void receive_rep (dns_rcv *r);
554		566
555	dns_connection (connection *c);	567	dns_connection (connection *c);
556	~dns_connection ();	568	~dns_connection ();
557	};	569	};
…		…
576	: dns (dns)	588	: dns (dns)
577	{	589	{
578	timeout = 0;	590	timeout = 0;
579	retry = 0;	591	retry = 0;
580	seqno = 0;	592	seqno = 0;
581	sent = NOW;	593	sent = ev::ev_now ();
582	stdhdr = false;	594	stdhdr = false;
583		595
584	pkt = new dns_packet;	596	pkt = new dns_packet;
585		597
586	pkt->id = next_id ();	598	pkt->id = next_id ();
…		…
617	void dns_snd::gen_stream_req (int seqno, byte_stream &stream)	629	void dns_snd::gen_stream_req (int seqno, byte_stream &stream)
618	{	630	{
619	stdhdr = true;	631	stdhdr = true;
620	this->seqno = seqno;	632	this->seqno = seqno;
621		633
622	timeout = NOW + INITIAL_TIMEOUT;	634	timeout = ev::ev_now () + INITIAL_TIMEOUT;
623		635
624	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);	636	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
625	pkt->qdcount = htons (1);	637	pkt->qdcount = htons (1);
626		638
627	int offs = 6*2;	639	int offs = 6*2;
…		…
662	pkt->len = offs;	674	pkt->len = offs;
663	}	675	}
664		676
665	void dns_snd::gen_syn_req ()	677	void dns_snd::gen_syn_req ()
666	{	678	{
667	timeout = NOW + INITIAL_SYN_TIMEOUT;	679	timeout = ev::ev_now () + INITIAL_SYN_TIMEOUT;
668
669	printf ("send syn\n");//D
670		680
671	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);	681	pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
672	pkt->qdcount = htons (1);	682	pkt->qdcount = htons (1);
673		683
674	int offs = 6 * 2;	684	int offs = 6 * 2;
…		…
713	/////////////////////////////////////////////////////////////////////////////	723	/////////////////////////////////////////////////////////////////////////////
714		724
715	dns_connection::dns_connection (connection *c)	725	dns_connection::dns_connection (connection *c)
716	: c (c)	726	: c (c)
717	, rcvdq (MAX_BACKLOG * 2)	727	, rcvdq (MAX_BACKLOG * 2)
718	, snddq (MAX_BACKLOG * 2)	728	, snddq (MAX_BACKLOG)
719	, tw (this, &dns_connection::time_cb)	729	, tw (this, &dns_connection::time_cb)
720	{	730	{
721	vpn = c->vpn;	731	vpn = c->vpn;
722		732
723	established = false;	733	established = false;
724		734
725	rcvseq = sndseq = 0;	735	rcvseq = repseq = sndseq = 0;
726		736
727	last_sent = last_received = 0;	737	last_sent = last_received = 0;
728	poll_interval = MIN_POLL_INTERVAL;	738	poll_interval = 0.5; // starting here
729	send_interval = 0.5; // starting rate	739	send_interval = 0.5; // starting rate
730	last_latency = INITIAL_TIMEOUT;	740	min_latency = INITIAL_TIMEOUT;
731	}	741	}
732		742
733	dns_connection::~dns_connection ()	743	dns_connection::~dns_connection ()
734	{	744	{
735	for (vector<dns_rcv *>::iterator i = rcvpq.begin ();	745	for (vector<dns_rcv *>::iterator i = rcvpq.begin ();
…		…
740		750
741	void dns_connection::receive_rep (dns_rcv *r)	751	void dns_connection::receive_rep (dns_rcv *r)
742	{	752	{
743	if (r->datalen)	753	if (r->datalen)
744	{	754	{
745	last_received = NOW;	755	last_received = ev::ev_now ();
746	tw.trigger ();	756	tw ();
747		757
748	poll_interval = send_interval;	758	poll_interval = send_interval;
749	}	759	}
750	else	760	else
751	{	761	{
752	poll_interval *= 1.5;	762	poll_interval *= 1.5;
		763
753	if (poll_interval > MAX_POLL_INTERVAL)	764	if (poll_interval > MAX_POLL_INTERVAL)
754	poll_interval = MAX_POLL_INTERVAL;	765	poll_interval = MAX_POLL_INTERVAL;
755	}	766	}
756		767
757	rcvpq.push_back (r);	768	rcvpq.push_back (r);
…		…
760		771
761	// find next packet	772	// find next packet
762	for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); )	773	for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); )
763	if (SEQNO_EQ (rcvseq, (*i)->seqno))	774	if (SEQNO_EQ (rcvseq, (*i)->seqno))
764	{	775	{
		776	//printf ("seqno eq %x %x\n", rcvseq, (*i)->seqno);//D
765	// enter the packet into our input stream	777	// enter the packet into our input stream
766	r = *i;	778	r = *i;
767		779
768	// remove the oldest packet, look forward, as it's oldest first	780	// remove the oldest packet, look forward, as it's oldest first
769	for (vector<dns_rcv *>::iterator j = rcvpq.begin (); j != rcvpq.end (); ++j)	781	for (vector<dns_rcv *>::iterator j = rcvpq.begin (); j != rcvpq.end (); ++j)
770	if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW))	782	if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW))
771	{	783	{
		784	//printf ("seqno RR %x %x\n", (*j)->seqno, rcvseq - MAX_WINDOW);//D
772	delete *j;	785	delete *j;
773	rcvpq.erase (j);	786	rcvpq.erase (j);
774	break;	787	break;
775	}	788	}
776		789
…		…
783	}	796	}
784		797
785	while (vpn_packet *pkt = rcvdq.get ())	798	while (vpn_packet *pkt = rcvdq.get ())
786	{	799	{
787	sockinfo si;	800	sockinfo si;
788	si.host = 0x01010101; si.port = htons (c->conf->id); si.prot = PROT_DNSv4;	801	si.host = htonl (c->conf->id); si.port = 0; si.prot = PROT_DNSv4;
789		802
790	vpn->recv_vpn_packet (pkt, si);	803	vpn->recv_vpn_packet (pkt, si);
791		804
792	delete pkt;	805	delete pkt;
793	}	806	}
…		…
807	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);	820	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);
808		821
809	if (0 == (flags & (FLAG_RESPONSE \| FLAG_OP_MASK))	822	if (0 == (flags & (FLAG_RESPONSE \| FLAG_OP_MASK))
810	&& pkt.qdcount == htons (1))	823	&& pkt.qdcount == htons (1))
811	{	824	{
812	char qname[MAXSIZE];	825	char qname [MAXSIZE];
813	int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);	826	int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
814		827
815	u16 qtype = pkt [offs++] << 8; qtype \|= pkt [offs++];	828	u16 qtype = pkt [offs++] << 8; qtype \|= pkt [offs++];
816	u16 qclass = pkt [offs++] << 8; qclass \|= pkt [offs++];	829	u16 qclass = pkt [offs++] << 8; qclass \|= pkt [offs++];
817		830
…		…
824		837
825	int dlen = strlen (THISNODE->domain);	838	int dlen = strlen (THISNODE->domain);
826		839
827	if (qclass == RR_CLASS_IN	840	if (qclass == RR_CLASS_IN
828	&& qlen > dlen + 1	841	&& qlen > dlen + 1
829	&& !memcmp (qname + qlen - dlen - 1, THISNODE->domain, dlen))	842	&& !memcmp (qname + qlen - (dlen + 1), THISNODE->domain, dlen))
830	{	843	{
831	// now generate reply	844	// now generate reply
832	pkt.ancount = htons (1); // one answer RR	845	pkt.ancount = htons (1); // one answer RR
833	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_OK);	846	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_OK);
834		847
…		…
847	if (0 < client && client <= conns.size ())	860	if (0 < client && client <= conns.size ())
848	{	861	{
849	connection *c = conns [client - 1];	862	connection *c = conns [client - 1];
850	dns_connection *dns = c->dns;	863	dns_connection *dns = c->dns;
851	dns_rcv *rcv;	864	dns_rcv *rcv;
852	bool in_seq;
853		865
854	if (dns)	866	if (dns)
855	{	867	{
856	for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); )	868	for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); )
857	if (SEQNO_EQ ((*i)->seqno, seqno))	869	if (SEQNO_EQ ((*i)->seqno, seqno))
…		…
868	memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len);	880	memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len);
869		881
870	goto duplicate_request;	882	goto duplicate_request;
871	}	883	}
872		884
873	in_seq = dns->rcvseq == seqno;
874
875	// new packet, queue	885	// new packet, queue
876	rcv = new dns_rcv (seqno, data, datalen);	886	rcv = new dns_rcv (seqno, data, datalen);
877	dns->receive_rep (rcv);	887	dns->receive_rep (rcv);
878	}	888	}
879		889
		890	{
880	pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section	891	pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section
881		892
882	int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A;	893	int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A;
883	pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type	894	pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type
884	pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class	895	pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
885	pkt [offs++] = 0; pkt [offs++] = 0;	896	pkt [offs++] = 0; pkt [offs++] = 0;
886	pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL	897	pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL
887		898
888	int rdlen_offs = offs += 2;	899	int rdlen_offs = offs += 2;
889		900
		901	if (dns)
		902	{
890	int dlen = (dns ? ntohs (dns->cfg.max_size) : MAX_PKT_SIZE) - offs;	903	int dlen = ntohs (dns->cfg.max_size) - offs;
		904
891	// bind doesn't compress well, so reduce further by one label length	905	// bind doesn't compress well, so reduce further by one label length
892	dlen -= qlen;	906	dlen -= qlen;
893		907
894	if (dns)
895	{
896	// only put data into in-order sequence packets, if	908	// only put data into in-order sequence packets, if
897	// we receive out-of-order packets we generate empty	909	// we receive out-of-order packets we generate empty
898	// replies	910	// replies
899	while (dlen > 1 && !dns->snddq.empty () && in_seq)	911	//printf ("%d - %d & %x (=%d) < %d\n", seqno, dns->repseq, SEQNO_MASK, (seqno - dns->repseq) & SEQNO_MASK, MAX_WINDOW);//D
		912	if (((seqno - dns->repseq) & SEQNO_MASK) <= MAX_WINDOW)
900	{	913	{
		914	dns->repseq = seqno;
		915
		916	while (dlen > 1 && !dns->snddq.empty ())
		917	{
901	int txtlen = dlen <= 255 ? dlen - 1 : 255;	918	int txtlen = dlen <= 255 ? dlen - 1 : 255;
902		919
903	if (txtlen > dns->snddq.size ())	920	if (txtlen > dns->snddq.size ())
904	txtlen = dns->snddq.size ();	921	txtlen = dns->snddq.size ();
905		922
906	pkt[offs++] = txtlen;	923	pkt[offs++] = txtlen;
907	memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);	924	memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
908	offs += txtlen;	925	offs += txtlen;
909	dns->snddq.remove (txtlen);	926	dns->snddq.remove (txtlen);
910		927
911	dlen -= txtlen + 1;	928	dlen -= txtlen + 1;
		929	}
912	}	930	}
913		931
914	// avoid empty TXT rdata	932	// avoid completely empty TXT rdata
915	if (offs == rdlen_offs)	933	if (offs == rdlen_offs)
916	pkt[offs++] = 0;	934	pkt[offs++] = 0;
917		935
918	slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());	936	slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
919	}	937	}
920	else	938	else
921	{	939	{
922	// send RST	940	// send RST
923	pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;	941	pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
924	pkt [offs++] = CMD_IP_RST;	942	pkt [offs++] = CMD_IP_RST;
925	}	943	}
926		944
927	int rdlen = offs - rdlen_offs;	945	int rdlen = offs - rdlen_offs;
928		946
929	pkt [rdlen_offs - 2] = rdlen >> 8;	947	pkt [rdlen_offs - 2] = rdlen >> 8;
930	pkt [rdlen_offs - 1] = rdlen;	948	pkt [rdlen_offs - 1] = rdlen;
931		949
932	if (dns)	950	if (dns)
933	{	951	{
934	// now update dns_rcv copy	952	// now update dns_rcv copy
935	rcv->pkt->len = offs;	953	rcv->pkt->len = offs;
936	memcpy (rcv->pkt->at (0), pkt.at (0), offs);	954	memcpy (rcv->pkt->at (0), pkt.at (0), offs);
937	}	955	}
		956	}
938		957
939	duplicate_request: ;	958	duplicate_request: ;
940	}	959	}
941	else	960	else
942	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);	961	pkt.flags = htons (DEFAULT_SERVER_FLAGS \| FLAG_RCODE_FORMERR);
…		…
954	pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class	973	pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
955	pkt [offs++] = 0; pkt [offs++] = 0;	974	pkt [offs++] = 0; pkt [offs++] = 0;
956	pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL	975	pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL
957	pkt [offs++] = 0; pkt [offs++] = 4; // rdlength	976	pkt [offs++] = 0; pkt [offs++] = 4; // rdlength
958		977
959	slog (L_INFO, _("DNS: client %d tries to connect"), client);	978	slog (L_INFO, _("DNS: client %d connects"), client);
960		979
961	pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;	980	pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
962	pkt [offs++] = CMD_IP_REJ;	981	pkt [offs++] = CMD_IP_REJ;
963		982
964	if (0 < client && client <= conns.size ())	983	if (0 < client && client <= conns.size ())
…		…
998	{	1017	{
999	dns_connection dns = (i)->dns;	1018	dns_connection dns = (i)->dns;
1000	connection *c = dns->c;	1019	connection *c = dns->c;
1001	int seqno = (*i)->seqno;	1020	int seqno = (*i)->seqno;
1002	u8 data[MAXSIZE], *datap = data;	1021	u8 data[MAXSIZE], *datap = data;
		1022	//printf ("rcv pkt %x\n", seqno);//D
1003		1023
1004	if ((*i)->retry)	1024	if ((*i)->retry)
1005	{	1025	{
1006	dns->send_interval *= 1.01;	1026	dns->send_interval *= 1.01;
1007	if (dns->send_interval > MAX_SEND_INTERVAL)	1027	if (dns->send_interval > MAX_SEND_INTERVAL)
1008	dns->send_interval = MAX_SEND_INTERVAL;	1028	dns->send_interval = MAX_SEND_INTERVAL;
1009	}	1029	}
1010	else	1030	else
1011	{	1031	{
1012	#if 1	1032	#if 0
1013	dns->send_interval *= 0.999;	1033	dns->send_interval *= 0.999;
1014	#endif	1034	#endif
1015	if (dns->send_interval < MIN_SEND_INTERVAL)
1016	dns->send_interval = MIN_SEND_INTERVAL;
1017
1018	// the latency surely puts an upper bound on	1035	// the latency surely puts an upper bound on
1019	// the minimum send interval	1036	// the minimum send interval
1020	double latency = NOW - (*i)->sent;	1037	double latency = ev::ev_now () - (*i)->sent;
		1038
		1039	if (latency < dns->min_latency)
1021	dns->last_latency = latency;	1040	dns->min_latency = latency;
1022		1041
1023	if (dns->send_interval > latency)	1042	if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor)
		1043	dns->send_interval = dns->min_latency * conf.dns_overlap_factor;
		1044
		1045	if (dns->send_interval < conf.dns_send_interval)
1024	dns->send_interval = latency;	1046	dns->send_interval = conf.dns_send_interval;
1025	}	1047	}
1026		1048
1027	delete *i;	1049	delete *i;
1028	dns_sndpq.erase (i);	1050	dns_sndpq.erase (i);
1029		1051
…		…
1134	break;	1156	break;
1135	}	1157	}
1136	}	1158	}
1137		1159
1138	void	1160	void
1139	vpn::dnsv4_ev (io_watcher &w, short revents)	1161	vpn::dnsv4_ev (ev::io &w, int revents)
1140	{	1162	{
1141	if (revents & EVENT_READ)	1163	if (revents & EV_READ)
1142	{	1164	{
1143	dns_packet *pkt = new dns_packet;	1165	dns_packet *pkt = new dns_packet;
1144	struct sockaddr_in sa;	1166	struct sockaddr_in sa;
1145	socklen_t sa_len = sizeof (sa);	1167	socklen_t sa_len = sizeof (sa);
1146		1168
1147	pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len);	1169	pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len);
1148		1170
1149	if (pkt->len > 0)	1171	if (pkt->len > 0)
1150	{	1172	{
1151	if (THISNODE->dns_port)	1173	if (ntohs (pkt->flags) & FLAG_RESPONSE)
		1174	dnsv4_client (*pkt);
		1175	else
1152	{	1176	{
1153	dnsv4_server (*pkt);	1177	dnsv4_server (*pkt);
1154	sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len);	1178	sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len);
1155	}	1179	}
1156	else
1157	dnsv4_client (*pkt);
1158		1180
1159	delete pkt;	1181	delete pkt;
1160	}	1182	}
1161	}	1183	}
1162	}	1184	}
1163		1185
1164	bool	1186	bool
1165	vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)	1187	vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
1166	{	1188	{
1167	int client = ntohs (si.port);	1189	int client = ntohl (si.host);
1168		1190
1169	assert (0 < client && client <= conns.size ());	1191	assert (0 < client && client <= conns.size ());
1170		1192
1171	connection *c = conns [client - 1];	1193	connection *c = conns [client - 1];
1172		1194
1173	if (!c->dns)	1195	if (!c->dns)
1174	c->dns = new dns_connection (c);	1196	c->dns = new dns_connection (c);
1175		1197
1176	if (!c->dns->snddq.put (pkt))	1198	if (c->dns->snddq.put (pkt))
1177	return false;
1178
1179	c->dns->tw.trigger ();	1199	c->dns->tw ();
1180		1200
		1201	// always return true even if the buffer overflows
1181	return true;	1202	return true;
1182	}	1203	}
1183		1204
1184	void	1205	void
1185	connection::dnsv4_reset_connection ()	1206	connection::dnsv4_reset_connection ()
…		…
1188	}	1209	}
1189		1210
1190	#define NEXT(w) do { if (next > (w)) next = w; } while (0)	1211	#define NEXT(w) do { if (next > (w)) next = w; } while (0)
1191		1212
1192	void	1213	void
1193	dns_connection::time_cb (time_watcher &w)	1214	dns_connection::time_cb (ev::timer &w, int revents)
1194	{	1215	{
1195	// servers have to be polled	1216	// servers have to be polled
1196	if (THISNODE->dns_port)	1217	if (THISNODE->dns_port)
1197	return;	1218	return;
1198		1219
1199	// check for timeouts and (re)transmit	1220	// check for timeouts and (re)transmit
1200	tstamp next = NOW + poll_interval;	1221	tstamp next = ev::now () + poll_interval;
1201	dns_snd *send = 0;	1222	dns_snd *send = 0;
1202		1223
1203	for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin ();	1224	for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin ();
1204	i != vpn->dns_sndpq.end ();	1225	i != vpn->dns_sndpq.end ();
1205	++i)	1226	++i)
1206	{	1227	{
1207	dns_snd r = i;	1228	dns_snd r = i;
1208		1229
1209	if (r->timeout <= NOW)	1230	if (r->timeout <= ev::ev_now ())
1210	{	1231	{
1211	if (!send)	1232	if (!send)
1212	{	1233	{
1213	send = r;	1234	send = r;
1214		1235
1215	r->retry++;	1236	r->retry++;
1216	r->timeout = NOW + (r->retry * last_latency * 8.);	1237	r->timeout = ev::ev_now () + (r->retry * min_latency * conf.dns_timeout_factor);
		1238	//printf ("RETRY %x (%d, %f)\n", r->seqno, r->retry, r->timeout - ev::ev_now ());//D
1217		1239
1218	// the following code changes the query section a bit, forcing	1240	// the following code changes the query section a bit, forcing
1219	// the forwarder to generate a new request	1241	// the forwarder to generate a new request
1220	if (r->stdhdr)	1242	if (r->stdhdr)
1221	{
1222	//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);
1223	//encode_header ((char )r->pkt->at (6 2 + 1), THISNODE->id, r->seqno, r->retry);	1243	encode_header ((char )r->pkt->at (6 2 + 1), THISNODE->id, r->seqno, r->retry);
1224	}
1225	}	1244	}
1226	}	1245	}
1227	else	1246	else
1228	NEXT (r->timeout);	1247	NEXT (r->timeout);
1229	}	1248	}
1230		1249
1231	if (last_sent + send_interval <= NOW)
1232	{
1233	if (!send)	1250	if (!send)
		1251	{
		1252	// generate a new packet, if wise
		1253
		1254	if (!established)
1234	{	1255	{
1235	// generate a new packet, if wise	1256	if (vpn->dns_sndpq.empty ())
1236
1237	if (!established)
1238	{	1257	{
1239	if (vpn->dns_sndpq.empty ())
1240	{
1241	send = new dns_snd (this);	1258	send = new dns_snd (this);
1242		1259
1243	printf ("new conn %p %d\n", this, c->conf->id);//D
1244	cfg.reset (THISNODE->id);	1260	cfg.reset (THISNODE->id);
1245	send->gen_syn_req ();	1261	send->gen_syn_req ();
1246	}
1247	}	1262	}
1248	else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING	1263	}
		1264	else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding
1249	&& !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))	1265	&& !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
		1266	{
		1267	if (last_sent + send_interval <= ev::ev_now ())
1250	{	1268	{
1251	//printf ("sending data request etc.\n"); //D	1269	//printf ("sending data request etc.\n"); //D
1252	if (!snddq.empty ())	1270	if (!snddq.empty () \|\| last_received + 1. > ev::ev_now ())
1253	{	1271	{
1254	poll_interval = send_interval;	1272	poll_interval = send_interval;
1255	NEXT (NOW + send_interval);	1273	NEXT (ev::ev_now () + send_interval);
1256	}	1274	}
1257		1275
1258	send = new dns_snd (this);	1276	send = new dns_snd (this);
1259	send->gen_stream_req (sndseq, snddq);	1277	send->gen_stream_req (sndseq, snddq);
1260	send->timeout = NOW + last_latency * 8.;	1278	send->timeout = ev::ev_now () + min_latency * conf.dns_timeout_factor;
		1279	//printf ("SEND %x (%f)\n", send->seqno, send->timeout - ev::ev_now (), min_latency, conf.dns_timeout_factor);//D
1261		1280
1262	sndseq = (sndseq + 1) & SEQNO_MASK;	1281	sndseq = (sndseq + 1) & SEQNO_MASK;
1263	}	1282	}
1264		1283	else
1265	if (send)	1284	NEXT (last_sent + send_interval);
1266	vpn->dns_sndpq.push_back (send);
1267	}	1285	}
1268		1286
1269	if (send)	1287	if (send)
1270	{	1288	vpn->dns_sndpq.push_back (send);
1271	last_sent = NOW;	1289	}
		1290
		1291	if (send)
		1292	{
		1293	last_sent = ev::ev_now ();
1272	sendto (vpn->dnsv4_fd,	1294	sendto (vpn->dnsv4_fd,
1273	send->pkt->at (0), send->pkt->len, 0,	1295	send->pkt->at (0), send->pkt->len, 0,
1274	vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());	1296	vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
1275	}
1276	}	1297	}
1277	else
1278	NEXT (last_sent + send_interval);
1279		1298
1280	slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d)",	1299	slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)",
1281	poll_interval, send_interval, next - NOW,	1300	poll_interval, send_interval, next - ev::ev_now (),
1282	vpn->dns_sndpq.size (), snddq.size ());	1301	vpn->dns_sndpq.size (), snddq.size (),
		1302	rcvpq.size ());
1283		1303
1284	// TODO: no idea when this happens, but when next < NOW, we have a problem	1304	// TODO: no idea when this happens, but when next < ev::ev_now (), we have a problem
1285	if (next < NOW + 0.0001)	1305	// doesn't seem to happen anymore
1286	next = NOW + 0.1;	1306	if (next < ev::ev_now () + 0.001)
		1307	next = ev::ev_now () + 0.1;
1287		1308
1288	w.start (next);	1309	w.start (next - ev::ev_now ());
1289	}	1310	}
1290		1311
1291	#endif	1312	#endif
1292		1313

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Comparing gvpe/src/vpn_dns.C (file contents): Revision 1.20 by pcg, Sun Mar 6 21:32:15 2005 UTC vs. Revision 1.42 by pcg, Sat Nov 10 05:14:22 2007 UTC

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Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.20 by pcg, Sun Mar 6 21:32:15 2005 UTC vs.
Revision 1.42 by pcg, Sat Nov 10 05:14:22 2007 UTC