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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 1.27 by pcg, Sat Mar 12 18:10:40 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>
… …
51 52
52#define INITIAL_TIMEOUT 0.1 // retry timeouts 53#define INITIAL_TIMEOUT 0.1 // retry timeouts
53#define INITIAL_SYN_TIMEOUT 10. // retry timeout for initial syn 54#define INITIAL_SYN_TIMEOUT 10. // retry timeout for initial syn
54 55
55#define MIN_SEND_INTERVAL 0.01 // wait at least this time between sending requests 56#define MIN_SEND_INTERVAL 0.01 // wait at least this time between sending requests
56#define MAX_SEND_INTERVAL 0.5 // optimistic? 57#define MAX_SEND_INTERVAL 2. // optimistic?
57 58
59#define LATENCY_FACTOR 0.5 // RTT * LATENCY_FACTOR == sending rate
58#define MAX_OUTSTANDING 10 // max. outstanding requests 60#define MAX_OUTSTANDING 40 // max. outstanding requests
59#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog 61#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 62#define MAX_BACKLOG (100*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE
61 63
62#define MAX_DOMAIN_SIZE 220 // 255 is legal limit, but bind doesn't compress well 64#define MAX_DOMAIN_SIZE 200 // 255 is legal limit, but bind doesn't compress well
63// 240 leaves about 4 bytes of server reply data 65// 240 leaves about 4 bytes of server reply data
64// every two request bytes less give room for one reply byte 66// every two request bytes less give room for one reply byte
65 67
66#define SEQNO_MASK 0x3fff 68#define SEQNO_MASK 0x3fff
67#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) ) 69#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )
… …
264static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO"); 266static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO");
265 267
266///////////////////////////////////////////////////////////////////////////// 268/////////////////////////////////////////////////////////////////////////////
267 269
268#define HDRSIZE 6 270#define HDRSIZE 6
269 271
270inline void encode_header (char *data, int clientid, int seqno, int retry = 0) 272inline void encode_header (char *data, int clientid, int seqno, int retry = 0)
271{ 273{
272 seqno &= SEQNO_MASK; 274 seqno &= SEQNO_MASK;
273 275
274 u8 hdr[3] = { 276 u8 hdr[3] = {
… …
356 return true; 358 return true;
357} 359}
358 360
359vpn_packet *byte_stream::get () 361vpn_packet *byte_stream::get ()
360{ 362{
363 unsigned int len;
364
365 for (;;)
366 {
361 unsigned int len = (data [0] << 8) | data [1]; 367 len = (data [0] << 8) | data [1];
362 368
363 if (len > MAXSIZE && fill >= 2) 369 if (len <= MAXSIZE || fill < 2)
364 assert (len <= MAXSIZE || fill < 2); // TODO handle this gracefully, connection reset 370 break;
365 371
372 // TODO: handle this better than skipping, e.g. by reset
373 slog (L_DEBUG, _("DNS: corrupted packet stream skipping a byte..."));
374 remove (1);
375 }
376
366 if (fill < len + 2) 377 if (fill < len + 2)
367 return 0; 378 return 0;
368 379
369 vpn_packet *pkt = new vpn_packet; 380 vpn_packet *pkt = new vpn_packet;
370 381
… …
399struct dns_cfg 410struct dns_cfg
400{ 411{
401 static int next_uid; 412 static int next_uid;
402 413
403 u8 id1, id2, id3, id4; 414 u8 id1, id2, id3, id4;
415
404 u8 version; 416 u8 version;
417 u8 flags;
405 u8 rrtype; 418 u8 rrtype;
406 u8 flags;
407 u8 def_ttl; 419 u8 def_ttl;
408 u8 rcv_cdc; 420
409 u8 snd_cdc;
410 u16 max_size;
411 u16 client; 421 u16 client;
412 u16 uid; // to make request unique 422 u16 uid; // to make request unique
413 423
414 u8 reserved[8]; 424 u16 max_size;
425 u8 seq_cdc;
426 u8 req_cdc;
427
428 u8 rep_cdc;
429 u8 r2, 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++;
439 457
440 memset (reserved, 0, 8); 458 r2 = r3 = r4 = 0;
459 r4 = r5 = r6 = r7 = 0;
441} 460}
442 461
443bool dns_cfg::valid () 462bool dns_cfg::valid ()
444{ 463{
445 return id1 == 'G' 464 return id1 == 'G'
446 && id2 == 'V' 465 && id2 == 'V'
447 && id3 == 'P' 466 && id3 == 'P'
448 && id4 == 'E' 467 && id4 == 'E'
468 && seq_cdc == 26
469 && req_cdc == 62
470 && rep_cdc == 0
449 && version == 1 471 && version == 1;
450 && flags == 0
451 && rcv_cdc == 0
452 && snd_cdc == 62
453 && max_size == ntohs (MAX_PKT_SIZE);
454} 472}
455 473
456struct dns_packet : net_packet 474struct dns_packet : net_packet
457{ 475{
458 u16 id; 476 u16 id;
459 u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4 477 u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4
460 u16 qdcount, ancount, nscount, arcount; 478 u16 qdcount, ancount, nscount, arcount;
461 479
462 u8 data[MAXSIZE - 6 * 2]; 480 u8 data [MAXSIZE - 6 * 2];
463 481
464 int decode_label (char *data, int size, int &offs); 482 int decode_label (char *data, int size, int &offs);
465}; 483};
466 484
467int dns_packet::decode_label (char *data, int size, int &offs) 485int dns_packet::decode_label (char *data, int size, int &offs)
… …
498 return data - orig; 516 return data - orig;
499} 517}
500 518
501///////////////////////////////////////////////////////////////////////////// 519/////////////////////////////////////////////////////////////////////////////
502 520
521static u16 dns_id = 0; // TODO: should be per-vpn
522
523static u16 next_id ()
524{
525 if (!dns_id)
526 dns_id = time (0);
527
528 // the simplest lsfr with periodicity 65535 i could find
529 dns_id = (dns_id << 1)
530 | (((dns_id >> 1)
531 ^ (dns_id >> 2)
532 ^ (dns_id >> 4)
533 ^ (dns_id >> 15)) & 1);
534
535 return dns_id;
536}
537
538struct dns_rcv;
539struct dns_snd;
540
541struct dns_connection
542{
543 connection *c;
544 struct vpn *vpn;
545
546 dns_cfg cfg;
547
548 bool established;
549
550 tstamp last_received;
551 tstamp last_sent;
552 double min_latency;
553 double poll_interval, send_interval;
554
555 vector<dns_rcv *> rcvpq;
556
557 byte_stream rcvdq; int rcvseq;
558 byte_stream snddq; int sndseq;
559
560 void time_cb (time_watcher &w); time_watcher tw;
561 void receive_rep (dns_rcv *r);
562
563 dns_connection (connection *c);
564 ~dns_connection ();
565};
566
503struct dns_snd 567struct dns_snd
504{ 568{
505 dns_packet *pkt; 569 dns_packet *pkt;
506 tstamp timeout, sent; 570 tstamp timeout, sent;
507 int retry; 571 int retry;
508 struct dns_connection *dns; 572 struct dns_connection *dns;
509 int seqno; 573 int seqno;
510 bool stdhdr; 574 bool stdhdr;
511 575
512 void gen_stream_req (int seqno, byte_stream &stream); 576 void gen_stream_req (int seqno, byte_stream &stream);
513 void gen_syn_req (const dns_cfg &cfg); 577 void gen_syn_req ();
514 578
515 dns_snd (dns_connection *dns); 579 dns_snd (dns_connection *dns);
516 ~dns_snd (); 580 ~dns_snd ();
517}; 581};
518
519static u16 dns_id = 12098; // TODO: should be per-vpn
520
521static 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}
532 582
533dns_snd::dns_snd (dns_connection *dns) 583dns_snd::dns_snd (dns_connection *dns)
534: dns (dns) 584: dns (dns)
535{ 585{
536 timeout = 0; 586 timeout = 0;
… …
581 631
582 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 632 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
583 pkt->qdcount = htons (1); 633 pkt->qdcount = htons (1);
584 634
585 int offs = 6*2; 635 int offs = 6*2;
586 int dlen = MAX_DOMAIN_SIZE - (strlen (THISNODE->domain) + 2); 636 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, 637 // 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 638 // so we need to have space for 2*MAX_DOMAIN_SIZE + header + extra
589 639
590 char enc[256], *encp = enc; 640 char enc[256], *encp = enc;
591 encode_header (enc, THISNODE->id, seqno); 641 encode_header (enc, THISNODE->id, seqno);
… …
609 encp += lbllen; 659 encp += lbllen;
610 660
611 enclen -= lbllen; 661 enclen -= lbllen;
612 } 662 }
613 663
614 append_domain (*pkt, offs, THISNODE->domain); 664 append_domain (*pkt, offs, dns->c->conf->domain);
615 665
616 (*pkt)[offs++] = 0; 666 (*pkt)[offs++] = 0;
617 (*pkt)[offs++] = RR_TYPE_ANY >> 8; (*pkt)[offs++] = RR_TYPE_ANY; 667 (*pkt)[offs++] = RR_TYPE_ANY >> 8; (*pkt)[offs++] = RR_TYPE_ANY;
618 (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN; 668 (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN;
619 669
620 pkt->len = offs; 670 pkt->len = offs;
621} 671}
622 672
623void dns_snd::gen_syn_req (const dns_cfg &cfg) 673void dns_snd::gen_syn_req ()
624{ 674{
625 timeout = NOW + INITIAL_SYN_TIMEOUT; 675 timeout = NOW + INITIAL_SYN_TIMEOUT;
626 676
627 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 677 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
628 pkt->qdcount = htons (1); 678 pkt->qdcount = htons (1);
629 679
630 int offs = 6*2; 680 int offs = 6 * 2;
631 681
632 int elen = cdc26.encode ((char *)pkt->at (offs + 1), (u8 *)&cfg, sizeof (dns_cfg)); 682 int elen = cdc26.encode ((char *)pkt->at (offs + 1), (u8 *)&dns->cfg, sizeof (dns_cfg));
633 683
634 assert (elen <= MAX_LBL_SIZE); 684 assert (elen <= MAX_LBL_SIZE);
635 685
636 (*pkt)[offs] = elen; 686 (*pkt)[offs] = elen;
637 offs += elen + 1; 687 offs += elen + 1;
638 append_domain (*pkt, offs, THISNODE->domain); 688 append_domain (*pkt, offs, dns->c->conf->domain);
639 689
640 (*pkt)[offs++] = 0; 690 (*pkt)[offs++] = 0;
641 (*pkt)[offs++] = RR_TYPE_A >> 8; (*pkt)[offs++] = RR_TYPE_A; 691 (*pkt)[offs++] = RR_TYPE_A >> 8; (*pkt)[offs++] = RR_TYPE_A;
642 (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN; 692 (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN;
643 693
… …
666 delete pkt; 716 delete pkt;
667} 717}
668 718
669///////////////////////////////////////////////////////////////////////////// 719/////////////////////////////////////////////////////////////////////////////
670 720
671struct 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
697dns_connection::dns_connection (connection *c) 721dns_connection::dns_connection (connection *c)
698: c (c) 722: c (c)
699, rcvdq (MAX_BACKLOG * 2) 723, rcvdq (MAX_BACKLOG * 2)
700, snddq (MAX_BACKLOG * 2) 724, snddq (MAX_BACKLOG * 2)
701, tw (this, &dns_connection::time_cb) 725, tw (this, &dns_connection::time_cb)
… …
707 rcvseq = sndseq = 0; 731 rcvseq = sndseq = 0;
708 732
709 last_sent = last_received = 0; 733 last_sent = last_received = 0;
710 poll_interval = MIN_POLL_INTERVAL; 734 poll_interval = MIN_POLL_INTERVAL;
711 send_interval = 0.5; // starting rate 735 send_interval = 0.5; // starting rate
712 last_latency = INITIAL_TIMEOUT; 736 min_latency = INITIAL_TIMEOUT;
713} 737}
714 738
715dns_connection::~dns_connection () 739dns_connection::~dns_connection ()
716{ 740{
717 for (vector<dns_rcv *>::iterator i = rcvpq.begin (); 741 for (vector<dns_rcv *>::iterator i = rcvpq.begin ();
… …
730 poll_interval = send_interval; 754 poll_interval = send_interval;
731 } 755 }
732 else 756 else
733 { 757 {
734 poll_interval *= 1.5; 758 poll_interval *= 1.5;
759
735 if (poll_interval > MAX_POLL_INTERVAL) 760 if (poll_interval > MAX_POLL_INTERVAL)
736 poll_interval = MAX_POLL_INTERVAL; 761 poll_interval = MAX_POLL_INTERVAL;
737 } 762 }
738 763
739 rcvpq.push_back (r); 764 rcvpq.push_back (r);
… …
765 } 790 }
766 791
767 while (vpn_packet *pkt = rcvdq.get ()) 792 while (vpn_packet *pkt = rcvdq.get ())
768 { 793 {
769 sockinfo si; 794 sockinfo si;
770 si.host = 0; si.port = 0; si.prot = PROT_DNSv4; 795 si.host = 0x01010101; si.port = htons (c->conf->id); si.prot = PROT_DNSv4;
771 796
772 vpn->recv_vpn_packet (pkt, si); 797 vpn->recv_vpn_packet (pkt, si);
773 798
774 delete pkt; 799 delete pkt;
775 } 800 }
… …
789 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR); 814 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR);
790 815
791 if (0 == (flags & (FLAG_RESPONSE | FLAG_OP_MASK)) 816 if (0 == (flags & (FLAG_RESPONSE | FLAG_OP_MASK))
792 && pkt.qdcount == htons (1)) 817 && pkt.qdcount == htons (1))
793 { 818 {
794 char qname[MAXSIZE]; 819 char qname [MAXSIZE];
795 int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs); 820 int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
796 821
797 u16 qtype = pkt [offs++] << 8; qtype |= pkt [offs++]; 822 u16 qtype = pkt [offs++] << 8; qtype |= pkt [offs++];
798 u16 qclass = pkt [offs++] << 8; qclass |= pkt [offs++]; 823 u16 qclass = pkt [offs++] << 8; qclass |= pkt [offs++];
799 824
… …
806 831
807 int dlen = strlen (THISNODE->domain); 832 int dlen = strlen (THISNODE->domain);
808 833
809 if (qclass == RR_CLASS_IN 834 if (qclass == RR_CLASS_IN
810 && qlen > dlen + 1 835 && qlen > dlen + 1
811 && !memcmp (qname + qlen - dlen - 1, THISNODE->domain, dlen)) 836 && !memcmp (qname + qlen - (dlen + 1), THISNODE->domain, dlen))
812 { 837 {
813 // now generate reply 838 // now generate reply
814 pkt.ancount = htons (1); // one answer RR 839 pkt.ancount = htons (1); // one answer RR
815 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_OK); 840 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_OK);
816 841
… …
857 // new packet, queue 882 // new packet, queue
858 rcv = new dns_rcv (seqno, data, datalen); 883 rcv = new dns_rcv (seqno, data, datalen);
859 dns->receive_rep (rcv); 884 dns->receive_rep (rcv);
860 } 885 }
861 886
887 {
862 pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section 888 pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section
863 889
864 int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A; 890 int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A;
865 pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type 891 pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type
866 pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class 892 pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
867 pkt [offs++] = 0; pkt [offs++] = 0; 893 pkt [offs++] = 0; pkt [offs++] = 0;
868 pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL 894 pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL
869 895
870 int rdlen_offs = offs += 2; 896 int rdlen_offs = offs += 2;
871 897
898 if (dns)
899 {
872 int dlen = (dns ? ntohs (dns->cfg.max_size) : MAX_PKT_SIZE) - offs; 900 int dlen = ntohs (dns->cfg.max_size) - offs;
901
873 // bind doesn't compress well, so reduce further by one label length 902 // bind doesn't compress well, so reduce further by one label length
874 dlen -= qlen; 903 dlen -= qlen;
875 904
876 if (dns)
877 {
878 // only put data into in-order sequence packets, if 905 // only put data into in-order sequence packets, if
879 // we receive out-of-order packets we generate empty 906 // we receive out-of-order packets we generate empty
880 // replies 907 // replies
881 while (dlen > 1 && !dns->snddq.empty () && in_seq) 908 while (dlen > 1 && !dns->snddq.empty () && in_seq)
882 { 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;
894 } 921 }
895 922
896 // avoid empty TXT rdata 923 // avoid empty TXT rdata
897 if (offs == rdlen_offs) 924 if (offs == rdlen_offs)
898 pkt[offs++] = 0; 925 pkt[offs++] = 0;
899 926
900 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ()); 927 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
901 } 928 }
902 else 929 else
903 { 930 {
904 // send RST 931 // send RST
905 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3; 932 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
906 pkt [offs++] = CMD_IP_RST; 933 pkt [offs++] = CMD_IP_RST;
907 } 934 }
908 935
909 int rdlen = offs - rdlen_offs; 936 int rdlen = offs - rdlen_offs;
910 937
911 pkt [rdlen_offs - 2] = rdlen >> 8; 938 pkt [rdlen_offs - 2] = rdlen >> 8;
912 pkt [rdlen_offs - 1] = rdlen; 939 pkt [rdlen_offs - 1] = rdlen;
913 940
914 if (dns) 941 if (dns)
915 { 942 {
916 // now update dns_rcv copy 943 // now update dns_rcv copy
917 rcv->pkt->len = offs; 944 rcv->pkt->len = offs;
918 memcpy (rcv->pkt->at (0), pkt.at (0), offs); 945 memcpy (rcv->pkt->at (0), pkt.at (0), offs);
919 } 946 }
947 }
920 948
921 duplicate_request: ; 949 duplicate_request: ;
922 } 950 }
923 else 951 else
924 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR); 952 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR);
… …
936 pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class 964 pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
937 pkt [offs++] = 0; pkt [offs++] = 0; 965 pkt [offs++] = 0; pkt [offs++] = 0;
938 pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL 966 pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL
939 pkt [offs++] = 0; pkt [offs++] = 4; // rdlength 967 pkt [offs++] = 0; pkt [offs++] = 4; // rdlength
940 968
941 slog (L_INFO, _("DNS: client %d tries to connect"), client); 969 slog (L_INFO, _("DNS: client %d connects"), client);
942 970
943 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3; 971 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
944 pkt [offs++] = CMD_IP_REJ; 972 pkt [offs++] = CMD_IP_REJ;
945 973
946 if (0 < client && client <= conns.size ()) 974 if (0 < client && client <= conns.size ())
… …
989 if (dns->send_interval > MAX_SEND_INTERVAL) 1017 if (dns->send_interval > MAX_SEND_INTERVAL)
990 dns->send_interval = MAX_SEND_INTERVAL; 1018 dns->send_interval = MAX_SEND_INTERVAL;
991 } 1019 }
992 else 1020 else
993 { 1021 {
994#if 1 1022#if 0
995 dns->send_interval *= 0.999; 1023 dns->send_interval *= 0.999;
996#endif 1024#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 1025 // the latency surely puts an upper bound on
1001 // the minimum send interval 1026 // the minimum send interval
1002 double latency = NOW - (*i)->sent; 1027 double latency = NOW - (*i)->sent;
1028
1029 if (latency < dns->min_latency)
1003 dns->last_latency = latency; 1030 dns->min_latency = latency;
1004 1031
1005 if (dns->send_interval > latency) 1032 if (dns->send_interval > dns->min_latency * LATENCY_FACTOR)
1006 dns->send_interval = latency; 1033 dns->send_interval = dns->min_latency * LATENCY_FACTOR;
1034
1035 if (dns->send_interval < MIN_SEND_INTERVAL)
1036 dns->send_interval = MIN_SEND_INTERVAL;
1007 } 1037 }
1008 1038
1009 delete *i; 1039 delete *i;
1010 dns_sndpq.erase (i); 1040 dns_sndpq.erase (i);
1011 1041
… …
1128 1158
1129 pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len); 1159 pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len);
1130 1160
1131 if (pkt->len > 0) 1161 if (pkt->len > 0)
1132 { 1162 {
1133 if (THISNODE->dns_port) 1163 if (ntohs (pkt->flags) & FLAG_RESPONSE)
1164 dnsv4_client (*pkt);
1165 else
1134 { 1166 {
1135 dnsv4_server (*pkt); 1167 dnsv4_server (*pkt);
1136 sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len); 1168 sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len);
1137 } 1169 }
1138 else
1139 dnsv4_client (*pkt);
1140 1170
1141 delete pkt; 1171 delete pkt;
1142 } 1172 }
1143 } 1173 }
1144} 1174}
1145 1175
1146bool 1176bool
1147connection::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) 1177vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
1148{ 1178{
1179 int client = ntohs (si.port);
1180
1181 assert (0 < client && client <= conns.size ());
1182
1183 connection *c = conns [client - 1];
1184
1149 if (!dns) 1185 if (!c->dns)
1150 dns = new dns_connection (this); 1186 c->dns = new dns_connection (c);
1151 1187
1152 if (!dns->snddq.put (pkt)) 1188 if (!c->dns->snddq.put (pkt))
1153 return false; 1189 return false;
1154 1190
1155 dns->tw.trigger (); 1191 c->dns->tw.trigger ();
1156 1192
1157 return true; 1193 return true;
1158} 1194}
1159 1195
1160void 1196void
… …
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 * 8.);
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) 1243 if (send || (last_sent + send_interval <= NOW))
1208 { 1244 {
1209 if (!send) 1245 if (!send)
1210 { 1246 {
1211 // generate a new packet, if wise 1247 // generate a new packet, if wise
1212 1248
… …
1215 if (vpn->dns_sndpq.empty ()) 1251 if (vpn->dns_sndpq.empty ())
1216 { 1252 {
1217 send = new dns_snd (this); 1253 send = new dns_snd (this);
1218 1254
1219 cfg.reset (THISNODE->id); 1255 cfg.reset (THISNODE->id);
1220 send->gen_syn_req (cfg); 1256 send->gen_syn_req ();
1221 } 1257 }
1222 } 1258 }
1223 else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING 1259 else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING
1224 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) 1260 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
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 * 8.;
1235 1272
1236 sndseq = (sndseq + 1) & SEQNO_MASK; 1273 sndseq = (sndseq + 1) & SEQNO_MASK;
1237 } 1274 }
1238 1275
1239 if (send) 1276 if (send && !send->retry)
1240 vpn->dns_sndpq.push_back (send); 1277 vpn->dns_sndpq.push_back (send);
1241 } 1278 }
1242 1279
1243 if (send) 1280 if (send)
1244 { 1281 {
… …
1249 } 1286 }
1250 } 1287 }
1251 else 1288 else
1252 NEXT (last_sent + send_interval); 1289 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
1259 if (next < NOW + 0.0001) 1297 if (next < NOW + 0.0001)
1260 next = NOW + 0.1; 1298 next = NOW + 0.1;
1261 1299

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