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Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.18 by pcg, Sat Mar 5 19:13:16 2005 UTC vs.
Revision 1.35 by pcg, Wed Mar 16 14:56:32 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
52#define TIMEOUT_FACTOR 2.
51 53
52#define INITIAL_TIMEOUT 0.1 // retry timeouts 54#define INITIAL_TIMEOUT 0.1 // retry timeouts
53#define INITIAL_SYN_TIMEOUT 10. // retry timeout for initial syn 55#define INITIAL_SYN_TIMEOUT 10. // retry timeout for initial syn
54 56
55#define MIN_SEND_INTERVAL 0.01 // wait at least this time between sending requests 57#define MIN_SEND_INTERVAL 0.001 // wait at least this time between sending requests
56#define MAX_SEND_INTERVAL 0.5 // optimistic? 58#define MAX_SEND_INTERVAL 2. // optimistic?
57 59
60#define LATENCY_FACTOR 0.5 // RTT * LATENCY_FACTOR == sending rate
58#define MAX_OUTSTANDING 10 // max. outstanding requests 61#define MAX_OUTSTANDING 100 // max. outstanding requests
59#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog 62#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 63#define MAX_BACKLOG (64*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE
61 64
62#define MAX_DOMAIN_SIZE 220 // 255 is legal limit, but bind doesn't compress well 65#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 66// 240 leaves about 4 bytes of server reply data
64// every two request bytes less give room for one reply byte 67// every request byte less give room for two reply bytes
65 68
66#define SEQNO_MASK 0x3fff 69#define SEQNO_MASK 0x3fff
67#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) ) 70#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )
68 71
69#define MAX_LBL_SIZE 63 72#define MAX_LBL_SIZE 63
… …
264static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO"); 267static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO");
265 268
266///////////////////////////////////////////////////////////////////////////// 269/////////////////////////////////////////////////////////////////////////////
267 270
268#define HDRSIZE 6 271#define HDRSIZE 6
269 272
270inline void encode_header (char *data, int clientid, int seqno, int retry = 0) 273inline void encode_header (char *data, int clientid, int seqno, int retry = 0)
271{ 274{
272 seqno &= SEQNO_MASK; 275 seqno &= SEQNO_MASK;
273 276
274 u8 hdr[3] = { 277 u8 hdr[3] = {
… …
408struct dns_cfg 411struct dns_cfg
409{ 412{
410 static int next_uid; 413 static int next_uid;
411 414
412 u8 id1, id2, id3, id4; 415 u8 id1, id2, id3, id4;
416
413 u8 version; 417 u8 version;
418 u8 flags;
414 u8 rrtype; 419 u8 rrtype;
415 u8 flags;
416 u8 def_ttl; 420 u8 def_ttl;
417 u8 rcv_cdc; 421
418 u8 snd_cdc;
419 u16 max_size;
420 u16 client; 422 u16 client;
421 u16 uid; // to make request unique 423 u16 uid; // to make request unique
422 424
423 u8 reserved[8]; 425 u16 max_size;
426 u8 seq_cdc;
427 u8 req_cdc;
428
429 u8 rep_cdc;
430 u8 delay; // time in 0.01s units that the server may delay replying packets
431 u8 r3, r4;
432
433 u8 r5, r6, r7, r8;
424 434
425 void reset (int clientid); 435 void reset (int clientid);
426 bool valid (); 436 bool valid ();
427}; 437};
428 438
… …
437 447
438 version = 1; 448 version = 1;
439 449
440 rrtype = RR_TYPE_TXT; 450 rrtype = RR_TYPE_TXT;
441 flags = 0; 451 flags = 0;
442 def_ttl = 1; 452 def_ttl = 0;
453 seq_cdc = 26;
454 req_cdc = 62;
443 rcv_cdc = 0; 455 rep_cdc = 0;
444 snd_cdc = 62;
445 max_size = ntohs (MAX_PKT_SIZE); 456 max_size = htons (MAX_PKT_SIZE);
446 client = ntohs (clientid); 457 client = htons (clientid);
447 uid = next_uid++; 458 uid = next_uid++;
459 delay = 0;
448 460
449 memset (reserved, 0, 8); 461 r3 = r4 = 0;
462 r4 = r5 = r6 = r7 = 0;
450} 463}
451 464
452bool dns_cfg::valid () 465bool dns_cfg::valid ()
453{ 466{
454 return id1 == 'G' 467 return id1 == 'G'
455 && id2 == 'V' 468 && id2 == 'V'
456 && id3 == 'P' 469 && id3 == 'P'
457 && id4 == 'E' 470 && id4 == 'E'
471 && seq_cdc == 26
472 && req_cdc == 62
473 && rep_cdc == 0
458 && version == 1 474 && version == 1;
459 && flags == 0
460 && rcv_cdc == 0
461 && snd_cdc == 62
462 && max_size == ntohs (MAX_PKT_SIZE);
463} 475}
464 476
465struct dns_packet : net_packet 477struct dns_packet : net_packet
466{ 478{
467 u16 id; 479 u16 id;
468 u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4 480 u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4
469 u16 qdcount, ancount, nscount, arcount; 481 u16 qdcount, ancount, nscount, arcount;
470 482
471 u8 data[MAXSIZE - 6 * 2]; 483 u8 data [MAXSIZE - 6 * 2];
472 484
473 int decode_label (char *data, int size, int &offs); 485 int decode_label (char *data, int size, int &offs);
474}; 486};
475 487
476int dns_packet::decode_label (char *data, int size, int &offs) 488int dns_packet::decode_label (char *data, int size, int &offs)
… …
538 550
539 bool established; 551 bool established;
540 552
541 tstamp last_received; 553 tstamp last_received;
542 tstamp last_sent; 554 tstamp last_sent;
543 double last_latency; 555 double min_latency;
544 double poll_interval, send_interval; 556 double poll_interval, send_interval;
545 557
546 vector<dns_rcv *> rcvpq; 558 vector<dns_rcv *> rcvpq;
547 559
548 byte_stream rcvdq; int rcvseq; 560 byte_stream rcvdq; int rcvseq; int repseq;
549 byte_stream snddq; int sndseq; 561 byte_stream snddq; int sndseq;
550 562
551 void time_cb (time_watcher &w); time_watcher tw; 563 void time_cb (time_watcher &w); time_watcher tw;
552 void receive_rep (dns_rcv *r); 564 void receive_rep (dns_rcv *r);
553 565
… …
622 634
623 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 635 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
624 pkt->qdcount = htons (1); 636 pkt->qdcount = htons (1);
625 637
626 int offs = 6*2; 638 int offs = 6*2;
627 int dlen = MAX_DOMAIN_SIZE - (strlen (THISNODE->domain) + 2); 639 int dlen = MAX_DOMAIN_SIZE - (strlen (dns->c->conf->domain) + 2);
628 // MAX_DOMAIN_SIZE is technically 255, but bind doesn't compress responses well, 640 // MAX_DOMAIN_SIZE is technically 255, but bind doesn't compress responses well,
629 // so we need to have space for 2*MAX_DOMAIN_SIZE + header + extra 641 // so we need to have space for 2*MAX_DOMAIN_SIZE + header + extra
630 642
631 char enc[256], *encp = enc; 643 char enc[256], *encp = enc;
632 encode_header (enc, THISNODE->id, seqno); 644 encode_header (enc, THISNODE->id, seqno);
… …
650 encp += lbllen; 662 encp += lbllen;
651 663
652 enclen -= lbllen; 664 enclen -= lbllen;
653 } 665 }
654 666
655 append_domain (*pkt, offs, THISNODE->domain); 667 append_domain (*pkt, offs, dns->c->conf->domain);
656 668
657 (*pkt)[offs++] = 0; 669 (*pkt)[offs++] = 0;
658 (*pkt)[offs++] = RR_TYPE_ANY >> 8; (*pkt)[offs++] = RR_TYPE_ANY; 670 (*pkt)[offs++] = RR_TYPE_ANY >> 8; (*pkt)[offs++] = RR_TYPE_ANY;
659 (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN; 671 (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN;
660 672
… …
663 675
664void dns_snd::gen_syn_req () 676void dns_snd::gen_syn_req ()
665{ 677{
666 timeout = NOW + INITIAL_SYN_TIMEOUT; 678 timeout = NOW + INITIAL_SYN_TIMEOUT;
667 679
668 printf ("send syn\n");//D
669
670 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 680 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
671 pkt->qdcount = htons (1); 681 pkt->qdcount = htons (1);
672 682
673 int offs = 6 * 2; 683 int offs = 6 * 2;
674 684
… …
676 686
677 assert (elen <= MAX_LBL_SIZE); 687 assert (elen <= MAX_LBL_SIZE);
678 688
679 (*pkt)[offs] = elen; 689 (*pkt)[offs] = elen;
680 offs += elen + 1; 690 offs += elen + 1;
681 append_domain (*pkt, offs, THISNODE->domain); 691 append_domain (*pkt, offs, dns->c->conf->domain);
682 692
683 (*pkt)[offs++] = 0; 693 (*pkt)[offs++] = 0;
684 (*pkt)[offs++] = RR_TYPE_A >> 8; (*pkt)[offs++] = RR_TYPE_A; 694 (*pkt)[offs++] = RR_TYPE_A >> 8; (*pkt)[offs++] = RR_TYPE_A;
685 (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN; 695 (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN;
686 696
… …
712///////////////////////////////////////////////////////////////////////////// 722/////////////////////////////////////////////////////////////////////////////
713 723
714dns_connection::dns_connection (connection *c) 724dns_connection::dns_connection (connection *c)
715: c (c) 725: c (c)
716, rcvdq (MAX_BACKLOG * 2) 726, rcvdq (MAX_BACKLOG * 2)
717, snddq (MAX_BACKLOG * 2) 727, snddq (MAX_BACKLOG)
718, tw (this, &dns_connection::time_cb) 728, tw (this, &dns_connection::time_cb)
719{ 729{
720 vpn = c->vpn; 730 vpn = c->vpn;
721 731
722 established = false; 732 established = false;
723 733
724 rcvseq = sndseq = 0; 734 rcvseq = repseq = sndseq = 0;
725 735
726 last_sent = last_received = 0; 736 last_sent = last_received = 0;
727 poll_interval = MIN_POLL_INTERVAL; 737 poll_interval = 0.5; // starting here
728 send_interval = 0.5; // starting rate 738 send_interval = 0.5; // starting rate
729 last_latency = INITIAL_TIMEOUT; 739 min_latency = INITIAL_TIMEOUT;
730} 740}
731 741
732dns_connection::~dns_connection () 742dns_connection::~dns_connection ()
733{ 743{
734 for (vector<dns_rcv *>::iterator i = rcvpq.begin (); 744 for (vector<dns_rcv *>::iterator i = rcvpq.begin ();
… …
747 poll_interval = send_interval; 757 poll_interval = send_interval;
748 } 758 }
749 else 759 else
750 { 760 {
751 poll_interval *= 1.5; 761 poll_interval *= 1.5;
762
752 if (poll_interval > MAX_POLL_INTERVAL) 763 if (poll_interval > MAX_POLL_INTERVAL)
753 poll_interval = MAX_POLL_INTERVAL; 764 poll_interval = MAX_POLL_INTERVAL;
754 } 765 }
755 766
756 rcvpq.push_back (r); 767 rcvpq.push_back (r);
… …
782 } 793 }
783 794
784 while (vpn_packet *pkt = rcvdq.get ()) 795 while (vpn_packet *pkt = rcvdq.get ())
785 { 796 {
786 sockinfo si; 797 sockinfo si;
787 si.host = 0x01010101; si.port = htons (c->conf->id); si.prot = PROT_DNSv4; 798 si.host = htonl (c->conf->id); si.port = 0; si.prot = PROT_DNSv4;
788 799
789 vpn->recv_vpn_packet (pkt, si); 800 vpn->recv_vpn_packet (pkt, si);
790 801
791 delete pkt; 802 delete pkt;
792 } 803 }
… …
806 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR); 817 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR);
807 818
808 if (0 == (flags & (FLAG_RESPONSE | FLAG_OP_MASK)) 819 if (0 == (flags & (FLAG_RESPONSE | FLAG_OP_MASK))
809 && pkt.qdcount == htons (1)) 820 && pkt.qdcount == htons (1))
810 { 821 {
811 char qname[MAXSIZE]; 822 char qname [MAXSIZE];
812 int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs); 823 int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
813 824
814 u16 qtype = pkt [offs++] << 8; qtype |= pkt [offs++]; 825 u16 qtype = pkt [offs++] << 8; qtype |= pkt [offs++];
815 u16 qclass = pkt [offs++] << 8; qclass |= pkt [offs++]; 826 u16 qclass = pkt [offs++] << 8; qclass |= pkt [offs++];
816 827
… …
823 834
824 int dlen = strlen (THISNODE->domain); 835 int dlen = strlen (THISNODE->domain);
825 836
826 if (qclass == RR_CLASS_IN 837 if (qclass == RR_CLASS_IN
827 && qlen > dlen + 1 838 && qlen > dlen + 1
828 && !memcmp (qname + qlen - dlen - 1, THISNODE->domain, dlen)) 839 && !memcmp (qname + qlen - (dlen + 1), THISNODE->domain, dlen))
829 { 840 {
830 // now generate reply 841 // now generate reply
831 pkt.ancount = htons (1); // one answer RR 842 pkt.ancount = htons (1); // one answer RR
832 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_OK); 843 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_OK);
833 844
… …
846 if (0 < client && client <= conns.size ()) 857 if (0 < client && client <= conns.size ())
847 { 858 {
848 connection *c = conns [client - 1]; 859 connection *c = conns [client - 1];
849 dns_connection *dns = c->dns; 860 dns_connection *dns = c->dns;
850 dns_rcv *rcv; 861 dns_rcv *rcv;
851 bool in_seq;
852 862
853 if (dns) 863 if (dns)
854 { 864 {
855 for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); ) 865 for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); )
856 if (SEQNO_EQ ((*i)->seqno, seqno)) 866 if (SEQNO_EQ ((*i)->seqno, seqno))
… …
867 memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len); 877 memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len);
868 878
869 goto duplicate_request; 879 goto duplicate_request;
870 } 880 }
871 881
872 in_seq = dns->rcvseq == seqno;
873
874 // new packet, queue 882 // new packet, queue
875 rcv = new dns_rcv (seqno, data, datalen); 883 rcv = new dns_rcv (seqno, data, datalen);
876 dns->receive_rep (rcv); 884 dns->receive_rep (rcv);
877 } 885 }
878 886
887 {
879 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
880 889
881 int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A; 890 int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A;
882 pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type 891 pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type
883 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
884 pkt [offs++] = 0; pkt [offs++] = 0; 893 pkt [offs++] = 0; pkt [offs++] = 0;
885 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
886 895
887 int rdlen_offs = offs += 2; 896 int rdlen_offs = offs += 2;
888 897
898 if (dns)
899 {
889 int dlen = (dns ? ntohs (dns->cfg.max_size) : MAX_PKT_SIZE) - offs; 900 int dlen = ntohs (dns->cfg.max_size) - offs;
901
890 // 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
891 dlen -= qlen; 903 dlen -= qlen;
892 904
893 if (dns)
894 {
895 // only put data into in-order sequence packets, if 905 // only put data into in-order sequence packets, if
896 // we receive out-of-order packets we generate empty 906 // we receive out-of-order packets we generate empty
897 // replies 907 // replies
898 while (dlen > 1 && !dns->snddq.empty () && in_seq) 908 //printf ("%d - %d & %x (=%d) < %d\n", seqno, dns->repseq, SEQNO_MASK, (seqno - dns->repseq) & SEQNO_MASK, MAX_WINDOW);//D
909 if (((seqno - dns->repseq) & SEQNO_MASK) <= MAX_WINDOW)
899 { 910 {
911 dns->repseq = seqno;
912
913 while (dlen > 1 && !dns->snddq.empty ())
914 {
900 int txtlen = dlen <= 255 ? dlen - 1 : 255; 915 int txtlen = dlen <= 255 ? dlen - 1 : 255;
901 916
902 if (txtlen > dns->snddq.size ()) 917 if (txtlen > dns->snddq.size ())
903 txtlen = dns->snddq.size (); 918 txtlen = dns->snddq.size ();
904 919
905 pkt[offs++] = txtlen; 920 pkt[offs++] = txtlen;
906 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen); 921 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
907 offs += txtlen; 922 offs += txtlen;
908 dns->snddq.remove (txtlen); 923 dns->snddq.remove (txtlen);
909 924
910 dlen -= txtlen + 1; 925 dlen -= txtlen + 1;
926 }
911 } 927 }
912 928
913 // avoid empty TXT rdata 929 // avoid completely empty TXT rdata
914 if (offs == rdlen_offs) 930 if (offs == rdlen_offs)
915 pkt[offs++] = 0; 931 pkt[offs++] = 0;
916 932
917 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ()); 933 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
918 } 934 }
919 else 935 else
920 { 936 {
921 // send RST 937 // send RST
922 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3; 938 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
923 pkt [offs++] = CMD_IP_RST; 939 pkt [offs++] = CMD_IP_RST;
924 } 940 }
925 941
926 int rdlen = offs - rdlen_offs; 942 int rdlen = offs - rdlen_offs;
927 943
928 pkt [rdlen_offs - 2] = rdlen >> 8; 944 pkt [rdlen_offs - 2] = rdlen >> 8;
929 pkt [rdlen_offs - 1] = rdlen; 945 pkt [rdlen_offs - 1] = rdlen;
930 946
931 if (dns) 947 if (dns)
932 { 948 {
933 // now update dns_rcv copy 949 // now update dns_rcv copy
934 rcv->pkt->len = offs; 950 rcv->pkt->len = offs;
935 memcpy (rcv->pkt->at (0), pkt.at (0), offs); 951 memcpy (rcv->pkt->at (0), pkt.at (0), offs);
936 } 952 }
953 }
937 954
938 duplicate_request: ; 955 duplicate_request: ;
939 } 956 }
940 else 957 else
941 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR); 958 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR);
… …
953 pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class 970 pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
954 pkt [offs++] = 0; pkt [offs++] = 0; 971 pkt [offs++] = 0; pkt [offs++] = 0;
955 pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL 972 pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL
956 pkt [offs++] = 0; pkt [offs++] = 4; // rdlength 973 pkt [offs++] = 0; pkt [offs++] = 4; // rdlength
957 974
958 slog (L_INFO, _("DNS: client %d tries to connect"), client); 975 slog (L_INFO, _("DNS: client %d connects"), client);
959 976
960 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3; 977 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
961 pkt [offs++] = CMD_IP_REJ; 978 pkt [offs++] = CMD_IP_REJ;
962 979
963 if (0 < client && client <= conns.size ()) 980 if (0 < client && client <= conns.size ())
… …
1006 if (dns->send_interval > MAX_SEND_INTERVAL) 1023 if (dns->send_interval > MAX_SEND_INTERVAL)
1007 dns->send_interval = MAX_SEND_INTERVAL; 1024 dns->send_interval = MAX_SEND_INTERVAL;
1008 } 1025 }
1009 else 1026 else
1010 { 1027 {
1011#if 1 1028#if 0
1012 dns->send_interval *= 0.999; 1029 dns->send_interval *= 0.999;
1013#endif 1030#endif
1014 if (dns->send_interval < MIN_SEND_INTERVAL)
1015 dns->send_interval = MIN_SEND_INTERVAL;
1016
1017 // the latency surely puts an upper bound on 1031 // the latency surely puts an upper bound on
1018 // the minimum send interval 1032 // the minimum send interval
1019 double latency = NOW - (*i)->sent; 1033 double latency = NOW - (*i)->sent;
1034
1035 if (latency < dns->min_latency)
1020 dns->last_latency = latency; 1036 dns->min_latency = latency;
1021 1037
1022 if (dns->send_interval > latency) 1038 if (dns->send_interval > dns->min_latency * LATENCY_FACTOR)
1023 dns->send_interval = latency; 1039 dns->send_interval = dns->min_latency * LATENCY_FACTOR;
1040
1041 if (dns->send_interval < MIN_SEND_INTERVAL)
1042 dns->send_interval = MIN_SEND_INTERVAL;
1024 } 1043 }
1025 1044
1026 delete *i; 1045 delete *i;
1027 dns_sndpq.erase (i); 1046 dns_sndpq.erase (i);
1028 1047
… …
1145 1164
1146 pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len); 1165 pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len);
1147 1166
1148 if (pkt->len > 0) 1167 if (pkt->len > 0)
1149 { 1168 {
1150 if (THISNODE->dns_port) 1169 if (ntohs (pkt->flags) & FLAG_RESPONSE)
1170 dnsv4_client (*pkt);
1171 else
1151 { 1172 {
1152 dnsv4_server (*pkt); 1173 dnsv4_server (*pkt);
1153 sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len); 1174 sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len);
1154 } 1175 }
1155 else
1156 dnsv4_client (*pkt);
1157 1176
1158 delete pkt; 1177 delete pkt;
1159 } 1178 }
1160 } 1179 }
1161} 1180}
1162 1181
1163bool 1182bool
1164vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) 1183vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
1165{ 1184{
1166 int client = ntohs (si.port); 1185 int client = ntohl (si.host);
1167 1186
1168 assert (0 < client && client <= conns.size ()); 1187 assert (0 < client && client <= conns.size ());
1169 1188
1170 connection *c = conns [client - 1]; 1189 connection *c = conns [client - 1];
1171 1190
1172 if (!c->dns) 1191 if (!c->dns)
1173 c->dns = new dns_connection (c); 1192 c->dns = new dns_connection (c);
1174 1193
1175 if (!c->dns->snddq.put (pkt)) 1194 if (c->dns->snddq.put (pkt))
1176 return false;
1177
1178 c->dns->tw.trigger (); 1195 c->dns->tw.trigger ();
1179 1196
1197 // always return true even if the buffer overflows
1180 return true; 1198 return true;
1181} 1199}
1182 1200
1183void 1201void
1184connection::dnsv4_reset_connection () 1202connection::dnsv4_reset_connection ()
… …
1210 if (!send) 1228 if (!send)
1211 { 1229 {
1212 send = r; 1230 send = r;
1213 1231
1214 r->retry++; 1232 r->retry++;
1215 r->timeout = NOW + (r->retry * last_latency * 8.); 1233 r->timeout = NOW + (r->retry * min_latency * TIMEOUT_FACTOR);
1216 1234
1217 // the following code changes the query section a bit, forcing 1235 // the following code changes the query section a bit, forcing
1218 // the forwarder to generate a new request 1236 // the forwarder to generate a new request
1219 if (r->stdhdr) 1237 if (r->stdhdr)
1220 { 1238 {
1221 //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); 1239 //printf ("reencoded header for ID %d retry %d:%d:%d (%p)\n", htons (r->pkt->id), THISNODE->id, r->seqno, r->retry);
1222 //encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry); 1240 //encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry);
1223 } 1241 }
1224 } 1242 }
1225 } 1243 }
1226 else 1244 else
1227 NEXT (r->timeout); 1245 NEXT (r->timeout);
1228 } 1246 }
1229 1247
1230 if (last_sent + send_interval <= NOW)
1231 {
1232 if (!send) 1248 if (!send)
1249 {
1250 // generate a new packet, if wise
1251
1252 if (!established)
1233 { 1253 {
1234 // generate a new packet, if wise 1254 if (vpn->dns_sndpq.empty ())
1235
1236 if (!established)
1237 { 1255 {
1238 if (vpn->dns_sndpq.empty ())
1239 {
1240 send = new dns_snd (this); 1256 send = new dns_snd (this);
1241 1257
1242 printf ("new conn %p %d\n", this, c->conf->id);//D
1243 cfg.reset (THISNODE->id); 1258 cfg.reset (THISNODE->id);
1244 send->gen_syn_req (); 1259 send->gen_syn_req ();
1245 }
1246 } 1260 }
1261 }
1247 else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING 1262 else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING
1248 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) 1263 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
1264 {
1265 if (last_sent + send_interval <= NOW)
1249 { 1266 {
1250 //printf ("sending data request etc.\n"); //D 1267 //printf ("sending data request etc.\n"); //D
1251 if (!snddq.empty ()) 1268 if (!snddq.empty () || last_received + 1. > NOW)
1252 { 1269 {
1253 poll_interval = send_interval; 1270 poll_interval = send_interval;
1254 NEXT (NOW + send_interval); 1271 NEXT (NOW + send_interval);
1255 } 1272 }
1256 1273
1257 send = new dns_snd (this); 1274 send = new dns_snd (this);
1258 send->gen_stream_req (sndseq, snddq); 1275 send->gen_stream_req (sndseq, snddq);
1259 send->timeout = NOW + last_latency * 8.; 1276 send->timeout = NOW + min_latency * TIMEOUT_FACTOR;
1260 1277
1261 sndseq = (sndseq + 1) & SEQNO_MASK; 1278 sndseq = (sndseq + 1) & SEQNO_MASK;
1262 } 1279 }
1263 1280 else
1264 if (send) 1281 NEXT (last_sent + send_interval);
1265 vpn->dns_sndpq.push_back (send);
1266 } 1282 }
1267 1283
1268 if (send) 1284 if (send)
1269 { 1285 vpn->dns_sndpq.push_back (send);
1286 }
1287
1288 if (send)
1289 {
1270 last_sent = NOW; 1290 last_sent = NOW;
1271 sendto (vpn->dnsv4_fd, 1291 sendto (vpn->dnsv4_fd,
1272 send->pkt->at (0), send->pkt->len, 0, 1292 send->pkt->at (0), send->pkt->len, 0,
1273 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); 1293 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
1274 }
1275 } 1294 }
1276 else
1277 NEXT (last_sent + send_interval);
1278 1295
1279 slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d)", 1296 slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)",
1280 poll_interval, send_interval, next - NOW, 1297 poll_interval, send_interval, next - NOW,
1281 vpn->dns_sndpq.size (), snddq.size ()); 1298 vpn->dns_sndpq.size (), snddq.size (),
1299 rcvpq.size ());
1282 1300
1283 // TODO: no idea when this happens, but when next < NOW, we have a problem 1301 // TODO: no idea when this happens, but when next < NOW, we have a problem
1284 if (next < NOW + 0.0001) 1302 if (next < NOW + 0.001)
1285 next = NOW + 0.1; 1303 next = NOW + 0.1;
1286 1304
1287 w.start (next); 1305 w.start (next);
1288} 1306}
1289 1307

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