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Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.26 by pcg, Tue Mar 8 17:25:27 2005 UTC vs.
Revision 1.48 by pcg, Tue Jul 28 00:42:14 2009 UTC

1/* 1/*
2 vpn_dns.C -- handle the dns tunnel part of the protocol. 2 vpn_dns.C -- handle the dns tunnel part of the protocol.
3 Copyright (C) 2003-2005 Marc Lehmann <gvpe@schmorp.de> 3 Copyright (C) 2003-2008 Marc Lehmann <gvpe@schmorp.de>
4 4
5 This file is part of GVPE. 5 This file is part of GVPE.
6 6
7 GVPE is free software; you can redistribute it and/or modify 7 GVPE is free software; you can redistribute it and/or modify it
8 it under the terms of the GNU General Public License as published by 8 under the terms of the GNU General Public License as published by the
9 the Free Software Foundation; either version 2 of the License, or 9 Free Software Foundation; either version 3 of the License, or (at your
10 (at your option) any later version. 10 option) any later version.
11 11
12 This program is distributed in the hope that it will be useful, 12 This program is distributed in the hope that it will be useful, but
13 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
15 GNU General Public License for more details. 15 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 along
18 along with gvpe; if not, write to the Free Software 18 with this program; if not, see <http://www.gnu.org/licenses/>.
19 Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 19
20 Additional permission under GNU GPL version 3 section 7
21
22 If you modify this Program, or any covered work, by linking or
23 combining it with the OpenSSL project's OpenSSL library (or a modified
24 version of that library), containing parts covered by the terms of the
25 OpenSSL or SSLeay licenses, the licensors of this Program grant you
26 additional permission to convey the resulting work. Corresponding
27 Source for a non-source form of such a combination shall include the
28 source code for the parts of OpenSSL used as well as that of the
29 covered work.
20*/ 30*/
31
32// TODO: EDNS0 option to increase dns mtu?
33// TODO: re-write dns packet parsing/creation using a safe mem-buffer
34// to ensure no buffer overflows or similar problems.
21 35
22#include "config.h" 36#include "config.h"
23 37
24#if ENABLE_DNS 38#if ENABLE_DNS
25 39
… …
38#include <unistd.h> 52#include <unistd.h>
39#include <fcntl.h> 53#include <fcntl.h>
40 54
41#include <map> 55#include <map>
42 56
57#include <cstdio> /* bug in libgmp: gmp.h relies on cstdio being included */
43#include <gmp.h> 58#include <gmp.h>
44 59
45#include "netcompat.h" 60#include "netcompat.h"
46 61
47#include "vpn.h" 62#include "vpn.h"
48 63
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 64#define MAX_POLL_INTERVAL 5. // how often to poll minimally when the server has no data
51#define ACTIVITY_INTERVAL 5. 65#define ACTIVITY_INTERVAL 5.
52 66
53#define INITIAL_TIMEOUT 0.1 // retry timeouts 67#define INITIAL_TIMEOUT 0.1 // retry timeouts
54#define INITIAL_SYN_TIMEOUT 10. // retry timeout for initial syn 68#define INITIAL_SYN_TIMEOUT 2. // retry timeout for initial syn
55 69
56#define MIN_SEND_INTERVAL 0.01 // wait at least this time between sending requests
57#define MAX_SEND_INTERVAL 0.5 // optimistic? 70#define MAX_SEND_INTERVAL 2. // optimistic?
58 71
59#define LATENCY_FACTOR 0.5 // RTT * LATENCY_FACTOR == sending rate
60#define MAX_OUTSTANDING 20 // max. outstanding requests
61#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog 72#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog
62#define MAX_BACKLOG (100*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE 73#define MAX_BACKLOG (64*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE
63 74
64#define MAX_DOMAIN_SIZE 200 // 255 is legal limit, but bind doesn't compress well 75#define MAX_DOMAIN_SIZE 240 // 255 is legal limit, but bind doesn't compress well
65// 240 leaves about 4 bytes of server reply data 76// 240 leaves about 4 bytes of server reply data
66// every two request bytes less give room for one reply byte 77// every request byte less give room for two reply bytes
67 78
68#define SEQNO_MASK 0x3fff 79#define SEQNO_MASK 0x3fff
69#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) ) 80#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )
70 81
71#define MAX_LBL_SIZE 63 82#define MAX_LBL_SIZE 63
72#define MAX_PKT_SIZE 512 83#define MAX_PKT_SIZE 512
73 84
74#define RR_TYPE_A 1 85#define RR_TYPE_A 1
75#define RR_TYPE_NULL 10 86#define RR_TYPE_NULL 10
76#define RR_TYPE_TXT 16 87#define RR_TYPE_TXT 16
88#define RR_TYPE_AAAA 28
77#define RR_TYPE_ANY 255 89#define RR_TYPE_ANY 255
78 90
79#define RR_CLASS_IN 1 91#define RR_CLASS_IN 1
80 92
81#define CMD_IP_1 207 93#define CMD_IP_1 207
… …
424 u16 max_size; 436 u16 max_size;
425 u8 seq_cdc; 437 u8 seq_cdc;
426 u8 req_cdc; 438 u8 req_cdc;
427 439
428 u8 rep_cdc; 440 u8 rep_cdc;
441 u8 delay; // time in 0.01s units that the server may delay replying packets
429 u8 r2, r3, r4; 442 u8 r3, r4;
430 443
431 u8 r5, r6, r7, r8; 444 u8 r5, r6, r7, r8;
432 445
433 void reset (int clientid); 446 void reset (int clientid);
434 bool valid (); 447 bool valid ();
… …
449 flags = 0; 462 flags = 0;
450 def_ttl = 0; 463 def_ttl = 0;
451 seq_cdc = 26; 464 seq_cdc = 26;
452 req_cdc = 62; 465 req_cdc = 62;
453 rep_cdc = 0; 466 rep_cdc = 0;
454 max_size = ntohs (MAX_PKT_SIZE); 467 max_size = htons (MAX_PKT_SIZE);
455 client = ntohs (clientid); 468 client = htons (clientid);
456 uid = next_uid++; 469 uid = next_uid++;
470 delay = 0;
457 471
458 r2 = r3 = r4 = 0; 472 r3 = r4 = 0;
459 r4 = r5 = r6 = r7 = 0; 473 r4 = r5 = r6 = r7 = 0;
460} 474}
461 475
462bool dns_cfg::valid () 476bool dns_cfg::valid ()
463{ 477{
478 // although the protocol itself allows for some configurability,
479 // only the following encoding/decoding settings are implemented.
464 return id1 == 'G' 480 return id1 == 'G'
465 && id2 == 'V' 481 && id2 == 'V'
466 && id3 == 'P' 482 && id3 == 'P'
467 && id4 == 'E' 483 && id4 == 'E'
468 && seq_cdc == 26 484 && seq_cdc == 26
469 && req_cdc == 62 485 && req_cdc == 62
470 && rep_cdc == 0 486 && rep_cdc == 0
471 && version == 1 487 && version == 1;
472 && max_size == ntohs (MAX_PKT_SIZE);
473} 488}
474 489
475struct dns_packet : net_packet 490struct dns_packet : net_packet
476{ 491{
477 u16 id; 492 u16 id;
… …
553 double min_latency; 568 double min_latency;
554 double poll_interval, send_interval; 569 double poll_interval, send_interval;
555 570
556 vector<dns_rcv *> rcvpq; 571 vector<dns_rcv *> rcvpq;
557 572
558 byte_stream rcvdq; int rcvseq; 573 byte_stream rcvdq; int rcvseq; int repseq;
559 byte_stream snddq; int sndseq; 574 byte_stream snddq; int sndseq;
560 575
561 void time_cb (time_watcher &w); time_watcher tw; 576 inline void time_cb (ev::timer &w, int revents); ev::timer tw;
562 void receive_rep (dns_rcv *r); 577 void receive_rep (dns_rcv *r);
563 578
564 dns_connection (connection *c); 579 dns_connection (connection *c);
565 ~dns_connection (); 580 ~dns_connection ();
566}; 581};
… …
585: dns (dns) 600: dns (dns)
586{ 601{
587 timeout = 0; 602 timeout = 0;
588 retry = 0; 603 retry = 0;
589 seqno = 0; 604 seqno = 0;
590 sent = NOW; 605 sent = ev_now ();
591 stdhdr = false; 606 stdhdr = false;
592 607
593 pkt = new dns_packet; 608 pkt = new dns_packet;
594 609
595 pkt->id = next_id (); 610 pkt->id = next_id ();
… …
626void dns_snd::gen_stream_req (int seqno, byte_stream &stream) 641void dns_snd::gen_stream_req (int seqno, byte_stream &stream)
627{ 642{
628 stdhdr = true; 643 stdhdr = true;
629 this->seqno = seqno; 644 this->seqno = seqno;
630 645
631 timeout = NOW + INITIAL_TIMEOUT; 646 timeout = ev_now () + INITIAL_TIMEOUT;
632 647
633 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 648 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
634 pkt->qdcount = htons (1); 649 pkt->qdcount = htons (1);
635 650
636 int offs = 6*2; 651 int offs = 6*2;
… …
671 pkt->len = offs; 686 pkt->len = offs;
672} 687}
673 688
674void dns_snd::gen_syn_req () 689void dns_snd::gen_syn_req ()
675{ 690{
676 timeout = NOW + INITIAL_SYN_TIMEOUT; 691 timeout = ev_now () + INITIAL_SYN_TIMEOUT;
677 692
678 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 693 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
679 pkt->qdcount = htons (1); 694 pkt->qdcount = htons (1);
680 695
681 int offs = 6 * 2; 696 int offs = 6 * 2;
… …
720///////////////////////////////////////////////////////////////////////////// 735/////////////////////////////////////////////////////////////////////////////
721 736
722dns_connection::dns_connection (connection *c) 737dns_connection::dns_connection (connection *c)
723: c (c) 738: c (c)
724, rcvdq (MAX_BACKLOG * 2) 739, rcvdq (MAX_BACKLOG * 2)
725, snddq (MAX_BACKLOG * 2) 740, snddq (MAX_BACKLOG)
726, tw (this, &dns_connection::time_cb)
727{ 741{
742 tw.set<dns_connection, &dns_connection::time_cb> (this);
743
728 vpn = c->vpn; 744 vpn = c->vpn;
729 745
730 established = false; 746 established = false;
731 747
732 rcvseq = sndseq = 0; 748 rcvseq = repseq = sndseq = 0;
733 749
734 last_sent = last_received = 0; 750 last_sent = last_received = 0;
735 poll_interval = MIN_POLL_INTERVAL; 751 poll_interval = 0.5; // starting here
736 send_interval = 0.5; // starting rate 752 send_interval = 0.5; // starting rate
737 min_latency = INITIAL_TIMEOUT; 753 min_latency = INITIAL_TIMEOUT;
738} 754}
739 755
740dns_connection::~dns_connection () 756dns_connection::~dns_connection ()
… …
747 763
748void dns_connection::receive_rep (dns_rcv *r) 764void dns_connection::receive_rep (dns_rcv *r)
749{ 765{
750 if (r->datalen) 766 if (r->datalen)
751 { 767 {
752 last_received = NOW; 768 last_received = ev_now ();
753 tw.trigger (); 769 tw ();
754 770
755 poll_interval = send_interval; 771 poll_interval = send_interval;
756 } 772 }
757 else 773 else
758 { 774 {
… …
768 784
769 // find next packet 785 // find next packet
770 for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); ) 786 for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); )
771 if (SEQNO_EQ (rcvseq, (*i)->seqno)) 787 if (SEQNO_EQ (rcvseq, (*i)->seqno))
772 { 788 {
789 //printf ("seqno eq %x %x\n", rcvseq, (*i)->seqno);//D
773 // enter the packet into our input stream 790 // enter the packet into our input stream
774 r = *i; 791 r = *i;
775 792
776 // remove the oldest packet, look forward, as it's oldest first 793 // remove the oldest packet, look forward, as it's oldest first
777 for (vector<dns_rcv *>::iterator j = rcvpq.begin (); j != rcvpq.end (); ++j) 794 for (vector<dns_rcv *>::iterator j = rcvpq.begin (); j != rcvpq.end (); ++j)
778 if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW)) 795 if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW))
779 { 796 {
797 //printf ("seqno RR %x %x\n", (*j)->seqno, rcvseq - MAX_WINDOW);//D
780 delete *j; 798 delete *j;
781 rcvpq.erase (j); 799 rcvpq.erase (j);
782 break; 800 break;
783 } 801 }
784 802
… …
791 } 809 }
792 810
793 while (vpn_packet *pkt = rcvdq.get ()) 811 while (vpn_packet *pkt = rcvdq.get ())
794 { 812 {
795 sockinfo si; 813 sockinfo si;
796 si.host = 0x01010101; si.port = htons (c->conf->id); si.prot = PROT_DNSv4; 814 si.host = htonl (c->conf->id); si.port = 0; si.prot = PROT_DNSv4;
797 815
798 vpn->recv_vpn_packet (pkt, si); 816 vpn->recv_vpn_packet (pkt, si);
799 817
800 delete pkt; 818 delete pkt;
801 } 819 }
… …
855 if (0 < client && client <= conns.size ()) 873 if (0 < client && client <= conns.size ())
856 { 874 {
857 connection *c = conns [client - 1]; 875 connection *c = conns [client - 1];
858 dns_connection *dns = c->dns; 876 dns_connection *dns = c->dns;
859 dns_rcv *rcv; 877 dns_rcv *rcv;
860 bool in_seq;
861 878
862 if (dns) 879 if (dns)
863 { 880 {
864 for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); ) 881 for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); )
865 if (SEQNO_EQ ((*i)->seqno, seqno)) 882 if (SEQNO_EQ ((*i)->seqno, seqno))
… …
876 memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len); 893 memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len);
877 894
878 goto duplicate_request; 895 goto duplicate_request;
879 } 896 }
880 897
881 in_seq = dns->rcvseq == seqno;
882
883 // new packet, queue 898 // new packet, queue
884 rcv = new dns_rcv (seqno, data, datalen); 899 rcv = new dns_rcv (seqno, data, datalen);
885 dns->receive_rep (rcv); 900 dns->receive_rep (rcv);
886 } 901 }
887 902
… …
894 pkt [offs++] = 0; pkt [offs++] = 0; 909 pkt [offs++] = 0; pkt [offs++] = 0;
895 pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL 910 pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL
896 911
897 int rdlen_offs = offs += 2; 912 int rdlen_offs = offs += 2;
898 913
899 int dlen = (dns ? ntohs (dns->cfg.max_size) : MAX_PKT_SIZE) - offs;
900 // bind doesn't compress well, so reduce further by one label length
901 dlen -= qlen;
902
903 if (dns) 914 if (dns)
904 { 915 {
916 int dlen = ntohs (dns->cfg.max_size) - offs;
917
918 // bind doesn't compress well, so reduce further by one label length
919 dlen -= qlen;
920
905 // only put data into in-order sequence packets, if 921 // only put data into in-order sequence packets, if
906 // we receive out-of-order packets we generate empty 922 // we receive out-of-order packets we generate empty
907 // replies 923 // replies
908 while (dlen > 1 && !dns->snddq.empty () && in_seq) 924 //printf ("%d - %d & %x (=%d) < %d\n", seqno, dns->repseq, SEQNO_MASK, (seqno - dns->repseq) & SEQNO_MASK, MAX_WINDOW);//D
925 if (((seqno - dns->repseq) & SEQNO_MASK) <= MAX_WINDOW)
909 { 926 {
927 dns->repseq = seqno;
928
929 while (dlen > 1 && !dns->snddq.empty ())
930 {
910 int txtlen = dlen <= 255 ? dlen - 1 : 255; 931 int txtlen = dlen <= 255 ? dlen - 1 : 255;
911 932
912 if (txtlen > dns->snddq.size ()) 933 if (txtlen > dns->snddq.size ())
913 txtlen = dns->snddq.size (); 934 txtlen = dns->snddq.size ();
914 935
915 pkt[offs++] = txtlen; 936 pkt[offs++] = txtlen;
916 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen); 937 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
917 offs += txtlen; 938 offs += txtlen;
918 dns->snddq.remove (txtlen); 939 dns->snddq.remove (txtlen);
919 940
920 dlen -= txtlen + 1; 941 dlen -= txtlen + 1;
942 }
921 } 943 }
922 944
923 // avoid empty TXT rdata 945 // avoid completely empty TXT rdata
924 if (offs == rdlen_offs) 946 if (offs == rdlen_offs)
925 pkt[offs++] = 0; 947 pkt[offs++] = 0;
926 948
927 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ()); 949 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
928 } 950 }
… …
1008 { 1030 {
1009 dns_connection *dns = (*i)->dns; 1031 dns_connection *dns = (*i)->dns;
1010 connection *c = dns->c; 1032 connection *c = dns->c;
1011 int seqno = (*i)->seqno; 1033 int seqno = (*i)->seqno;
1012 u8 data[MAXSIZE], *datap = data; 1034 u8 data[MAXSIZE], *datap = data;
1035 //printf ("rcv pkt %x\n", seqno);//D
1013 1036
1014 if ((*i)->retry) 1037 if ((*i)->retry)
1015 { 1038 {
1016 dns->send_interval *= 1.01; 1039 dns->send_interval *= 1.01;
1017 if (dns->send_interval > MAX_SEND_INTERVAL) 1040 if (dns->send_interval > MAX_SEND_INTERVAL)
… …
1020 else 1043 else
1021 { 1044 {
1022#if 0 1045#if 0
1023 dns->send_interval *= 0.999; 1046 dns->send_interval *= 0.999;
1024#endif 1047#endif
1025 if (dns->send_interval < MIN_SEND_INTERVAL)
1026 dns->send_interval = MIN_SEND_INTERVAL;
1027
1028 // the latency surely puts an upper bound on 1048 // the latency surely puts an upper bound on
1029 // the minimum send interval 1049 // the minimum send interval
1030 double latency = NOW - (*i)->sent; 1050 double latency = ev_now () - (*i)->sent;
1031 1051
1032 if (latency < dns->min_latency) 1052 if (latency < dns->min_latency)
1033 dns->min_latency = latency; 1053 dns->min_latency = latency;
1034 1054
1035 if (dns->send_interval > dns->min_latency * LATENCY_FACTOR) 1055 if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor)
1036 dns->send_interval = dns->min_latency * LATENCY_FACTOR; 1056 dns->send_interval = dns->min_latency * conf.dns_overlap_factor;
1057
1058 if (dns->send_interval < conf.dns_send_interval)
1059 dns->send_interval = conf.dns_send_interval;
1037 } 1060 }
1038 1061
1039 delete *i; 1062 delete *i;
1040 dns_sndpq.erase (i); 1063 dns_sndpq.erase (i);
1041 1064
… …
1146 break; 1169 break;
1147 } 1170 }
1148} 1171}
1149 1172
1150void 1173void
1151vpn::dnsv4_ev (io_watcher &w, short revents) 1174vpn::dnsv4_ev (ev::io &w, int revents)
1152{ 1175{
1153 if (revents & EVENT_READ) 1176 if (revents & EV_READ)
1154 { 1177 {
1155 dns_packet *pkt = new dns_packet; 1178 dns_packet *pkt = new dns_packet;
1156 struct sockaddr_in sa; 1179 struct sockaddr_in sa;
1157 socklen_t sa_len = sizeof (sa); 1180 socklen_t sa_len = sizeof (sa);
1158 1181
… …
1174} 1197}
1175 1198
1176bool 1199bool
1177vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) 1200vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
1178{ 1201{
1179 int client = ntohs (si.port); 1202 int client = ntohl (si.host);
1180 1203
1181 assert (0 < client && client <= conns.size ()); 1204 assert (0 < client && client <= conns.size ());
1182 1205
1183 connection *c = conns [client - 1]; 1206 connection *c = conns [client - 1];
1184 1207
1185 if (!c->dns) 1208 if (!c->dns)
1186 c->dns = new dns_connection (c); 1209 c->dns = new dns_connection (c);
1187 1210
1188 if (!c->dns->snddq.put (pkt)) 1211 if (c->dns->snddq.put (pkt))
1189 return false;
1190
1191 c->dns->tw.trigger (); 1212 c->dns->tw ();
1192 1213
1214 // always return true even if the buffer overflows
1193 return true; 1215 return true;
1194} 1216}
1195 1217
1196void 1218void
1197connection::dnsv4_reset_connection () 1219connection::dnsv4_reset_connection ()
… …
1200} 1222}
1201 1223
1202#define NEXT(w) do { if (next > (w)) next = w; } while (0) 1224#define NEXT(w) do { if (next > (w)) next = w; } while (0)
1203 1225
1204void 1226void
1205dns_connection::time_cb (time_watcher &w) 1227dns_connection::time_cb (ev::timer &w, int revents)
1206{ 1228{
1207 // servers have to be polled 1229 // servers have to be polled
1208 if (THISNODE->dns_port) 1230 if (THISNODE->dns_port)
1209 return; 1231 return;
1210 1232
1211 // check for timeouts and (re)transmit 1233 // check for timeouts and (re)transmit
1212 tstamp next = NOW + poll_interval; 1234 tstamp next = ev::now () + poll_interval;
1213 dns_snd *send = 0; 1235 dns_snd *send = 0;
1214 1236
1215 for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin (); 1237 for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin ();
1216 i != vpn->dns_sndpq.end (); 1238 i != vpn->dns_sndpq.end ();
1217 ++i) 1239 ++i)
1218 { 1240 {
1219 dns_snd *r = *i; 1241 dns_snd *r = *i;
1220 1242
1221 if (r->timeout <= NOW) 1243 if (r->timeout <= ev_now ())
1222 { 1244 {
1223 if (!send) 1245 if (!send)
1224 { 1246 {
1225 send = r; 1247 send = r;
1226 1248
1227 r->retry++; 1249 r->retry++;
1228 r->timeout = NOW + (r->retry * min_latency * 8.); 1250 r->timeout = ev_now () + (r->retry * min_latency * conf.dns_timeout_factor);
1251 //printf ("RETRY %x (%d, %f)\n", r->seqno, r->retry, r->timeout - ev_now ());//D
1229 1252
1230 // the following code changes the query section a bit, forcing 1253 // the following code changes the query section a bit, forcing
1231 // the forwarder to generate a new request 1254 // the forwarder to generate a new request
1232 if (r->stdhdr) 1255 if (r->stdhdr)
1233 {
1234 //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);
1235 //encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry); 1256 encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry);
1236 }
1237 } 1257 }
1238 } 1258 }
1239 else 1259 else
1240 NEXT (r->timeout); 1260 NEXT (r->timeout);
1241 } 1261 }
1242 1262
1243 if (last_sent + send_interval <= NOW)
1244 {
1245 if (!send) 1263 if (!send)
1264 {
1265 // generate a new packet, if wise
1266
1267 if (!established)
1246 { 1268 {
1247 // generate a new packet, if wise 1269 if (vpn->dns_sndpq.empty ())
1248
1249 if (!established)
1250 { 1270 {
1251 if (vpn->dns_sndpq.empty ())
1252 {
1253 send = new dns_snd (this); 1271 send = new dns_snd (this);
1254 1272
1255 cfg.reset (THISNODE->id); 1273 cfg.reset (THISNODE->id);
1256 send->gen_syn_req (); 1274 send->gen_syn_req ();
1257 }
1258 } 1275 }
1259 else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING 1276 }
1277 else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding
1260 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) 1278 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
1279 {
1280 if (last_sent + send_interval <= ev_now ())
1261 { 1281 {
1262 //printf ("sending data request etc.\n"); //D 1282 //printf ("sending data request etc.\n"); //D
1263 if (!snddq.empty () || last_received + 1. > NOW) 1283 if (!snddq.empty () || last_received + 1. > ev_now ())
1264 { 1284 {
1265 poll_interval = send_interval; 1285 poll_interval = send_interval;
1266 NEXT (NOW + send_interval); 1286 NEXT (ev_now () + send_interval);
1267 } 1287 }
1268 1288
1269 send = new dns_snd (this); 1289 send = new dns_snd (this);
1270 send->gen_stream_req (sndseq, snddq); 1290 send->gen_stream_req (sndseq, snddq);
1271 send->timeout = NOW + min_latency * 8.; 1291 send->timeout = ev_now () + min_latency * conf.dns_timeout_factor;
1292 //printf ("SEND %x (%f)\n", send->seqno, send->timeout - ev_now (), min_latency, conf.dns_timeout_factor);//D
1272 1293
1273 sndseq = (sndseq + 1) & SEQNO_MASK; 1294 sndseq = (sndseq + 1) & SEQNO_MASK;
1274 } 1295 }
1275 1296 else
1276 if (send) 1297 NEXT (last_sent + send_interval);
1277 vpn->dns_sndpq.push_back (send);
1278 } 1298 }
1279 1299
1280 if (send) 1300 if (send)
1281 { 1301 vpn->dns_sndpq.push_back (send);
1282 last_sent = NOW; 1302 }
1303
1304 if (send)
1305 {
1306 last_sent = ev_now ();
1283 sendto (vpn->dnsv4_fd, 1307 sendto (vpn->dnsv4_fd,
1284 send->pkt->at (0), send->pkt->len, 0, 1308 send->pkt->at (0), send->pkt->len, 0,
1285 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); 1309 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
1286 }
1287 } 1310 }
1288 else
1289 NEXT (last_sent + send_interval);
1290 1311
1291 slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d)", 1312 slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)",
1292 poll_interval, send_interval, next - NOW, 1313 poll_interval, send_interval, next - ev_now (),
1293 vpn->dns_sndpq.size (), snddq.size ()); 1314 vpn->dns_sndpq.size (), snddq.size (),
1315 rcvpq.size ());
1294 1316
1295 // TODO: no idea when this happens, but when next < NOW, we have a problem 1317 // TODO: no idea when this happens, but when next < ev_now (), we have a problem
1318 // doesn't seem to happen anymore
1296 if (next < NOW + 0.0001) 1319 if (next < ev_now () + 0.001)
1297 next = NOW + 0.1; 1320 next = ev_now () + 0.1;
1298 1321
1299 w.start (next); 1322 w.start (next - ev_now ());
1300} 1323}
1301 1324
1302#endif 1325#endif
1303 1326

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