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Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.25 by pcg, Mon Mar 7 22:24:24 2005 UTC vs.
Revision 1.47 by pcg, Thu Aug 7 17:54:27 2008 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
… …
424 u16 max_size; 435 u16 max_size;
425 u8 seq_cdc; 436 u8 seq_cdc;
426 u8 req_cdc; 437 u8 req_cdc;
427 438
428 u8 rep_cdc; 439 u8 rep_cdc;
440 u8 delay; // time in 0.01s units that the server may delay replying packets
429 u8 r2, r3, r4; 441 u8 r3, r4;
430 442
431 u8 r5, r6, r7, r8; 443 u8 r5, r6, r7, r8;
432 444
433 void reset (int clientid); 445 void reset (int clientid);
434 bool valid (); 446 bool valid ();
… …
449 flags = 0; 461 flags = 0;
450 def_ttl = 0; 462 def_ttl = 0;
451 seq_cdc = 26; 463 seq_cdc = 26;
452 req_cdc = 62; 464 req_cdc = 62;
453 rep_cdc = 0; 465 rep_cdc = 0;
454 max_size = ntohs (MAX_PKT_SIZE); 466 max_size = htons (MAX_PKT_SIZE);
455 client = ntohs (clientid); 467 client = htons (clientid);
456 uid = next_uid++; 468 uid = next_uid++;
469 delay = 0;
457 470
458 r2 = r3 = r4 = 0; 471 r3 = r4 = 0;
459 r4 = r5 = r6 = r7 = 0; 472 r4 = r5 = r6 = r7 = 0;
460} 473}
461 474
462bool dns_cfg::valid () 475bool dns_cfg::valid ()
463{ 476{
477 // although the protocol itself allows for some configurability,
478 // only the following encoding/decoding settings are implemented.
464 return id1 == 'G' 479 return id1 == 'G'
465 && id2 == 'V' 480 && id2 == 'V'
466 && id3 == 'P' 481 && id3 == 'P'
467 && id4 == 'E' 482 && id4 == 'E'
468 && seq_cdc == 26 483 && seq_cdc == 26
469 && req_cdc == 62 484 && req_cdc == 62
470 && rep_cdc == 0 485 && rep_cdc == 0
471 && version == 1 486 && version == 1;
472 && max_size == ntohs (MAX_PKT_SIZE);
473} 487}
474 488
475struct dns_packet : net_packet 489struct dns_packet : net_packet
476{ 490{
477 u16 id; 491 u16 id;
… …
553 double min_latency; 567 double min_latency;
554 double poll_interval, send_interval; 568 double poll_interval, send_interval;
555 569
556 vector<dns_rcv *> rcvpq; 570 vector<dns_rcv *> rcvpq;
557 571
558 byte_stream rcvdq; int rcvseq; 572 byte_stream rcvdq; int rcvseq; int repseq;
559 byte_stream snddq; int sndseq; 573 byte_stream snddq; int sndseq;
560 574
561 void time_cb (time_watcher &w); time_watcher tw; 575 inline void time_cb (ev::timer &w, int revents); ev::timer tw;
562 void receive_rep (dns_rcv *r); 576 void receive_rep (dns_rcv *r);
563 577
564 dns_connection (connection *c); 578 dns_connection (connection *c);
565 ~dns_connection (); 579 ~dns_connection ();
566}; 580};
… …
585: dns (dns) 599: dns (dns)
586{ 600{
587 timeout = 0; 601 timeout = 0;
588 retry = 0; 602 retry = 0;
589 seqno = 0; 603 seqno = 0;
590 sent = NOW; 604 sent = ev_now ();
591 stdhdr = false; 605 stdhdr = false;
592 606
593 pkt = new dns_packet; 607 pkt = new dns_packet;
594 608
595 pkt->id = next_id (); 609 pkt->id = next_id ();
… …
626void dns_snd::gen_stream_req (int seqno, byte_stream &stream) 640void dns_snd::gen_stream_req (int seqno, byte_stream &stream)
627{ 641{
628 stdhdr = true; 642 stdhdr = true;
629 this->seqno = seqno; 643 this->seqno = seqno;
630 644
631 timeout = NOW + INITIAL_TIMEOUT; 645 timeout = ev_now () + INITIAL_TIMEOUT;
632 646
633 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 647 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
634 pkt->qdcount = htons (1); 648 pkt->qdcount = htons (1);
635 649
636 int offs = 6*2; 650 int offs = 6*2;
… …
671 pkt->len = offs; 685 pkt->len = offs;
672} 686}
673 687
674void dns_snd::gen_syn_req () 688void dns_snd::gen_syn_req ()
675{ 689{
676 timeout = NOW + INITIAL_SYN_TIMEOUT; 690 timeout = ev_now () + INITIAL_SYN_TIMEOUT;
677 691
678 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 692 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
679 pkt->qdcount = htons (1); 693 pkt->qdcount = htons (1);
680 694
681 int offs = 6 * 2; 695 int offs = 6 * 2;
… …
720///////////////////////////////////////////////////////////////////////////// 734/////////////////////////////////////////////////////////////////////////////
721 735
722dns_connection::dns_connection (connection *c) 736dns_connection::dns_connection (connection *c)
723: c (c) 737: c (c)
724, rcvdq (MAX_BACKLOG * 2) 738, rcvdq (MAX_BACKLOG * 2)
725, snddq (MAX_BACKLOG * 2) 739, snddq (MAX_BACKLOG)
726, tw (this, &dns_connection::time_cb)
727{ 740{
741 tw.set<dns_connection, &dns_connection::time_cb> (this);
742
728 vpn = c->vpn; 743 vpn = c->vpn;
729 744
730 established = false; 745 established = false;
731 746
732 rcvseq = sndseq = 0; 747 rcvseq = repseq = sndseq = 0;
733 748
734 last_sent = last_received = 0; 749 last_sent = last_received = 0;
735 poll_interval = MIN_POLL_INTERVAL; 750 poll_interval = 0.5; // starting here
736 send_interval = 0.5; // starting rate 751 send_interval = 0.5; // starting rate
737 min_latency = INITIAL_TIMEOUT; 752 min_latency = INITIAL_TIMEOUT;
738} 753}
739 754
740dns_connection::~dns_connection () 755dns_connection::~dns_connection ()
… …
747 762
748void dns_connection::receive_rep (dns_rcv *r) 763void dns_connection::receive_rep (dns_rcv *r)
749{ 764{
750 if (r->datalen) 765 if (r->datalen)
751 { 766 {
752 last_received = NOW; 767 last_received = ev_now ();
753 tw.trigger (); 768 tw ();
754 769
755 poll_interval = send_interval; 770 poll_interval = send_interval;
756 } 771 }
757 else 772 else
758 { 773 {
… …
768 783
769 // find next packet 784 // find next packet
770 for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); ) 785 for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); )
771 if (SEQNO_EQ (rcvseq, (*i)->seqno)) 786 if (SEQNO_EQ (rcvseq, (*i)->seqno))
772 { 787 {
788 //printf ("seqno eq %x %x\n", rcvseq, (*i)->seqno);//D
773 // enter the packet into our input stream 789 // enter the packet into our input stream
774 r = *i; 790 r = *i;
775 791
776 // remove the oldest packet, look forward, as it's oldest first 792 // remove the oldest packet, look forward, as it's oldest first
777 for (vector<dns_rcv *>::iterator j = rcvpq.begin (); j != rcvpq.end (); ++j) 793 for (vector<dns_rcv *>::iterator j = rcvpq.begin (); j != rcvpq.end (); ++j)
778 if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW)) 794 if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW))
779 { 795 {
796 //printf ("seqno RR %x %x\n", (*j)->seqno, rcvseq - MAX_WINDOW);//D
780 delete *j; 797 delete *j;
781 rcvpq.erase (j); 798 rcvpq.erase (j);
782 break; 799 break;
783 } 800 }
784 801
… …
791 } 808 }
792 809
793 while (vpn_packet *pkt = rcvdq.get ()) 810 while (vpn_packet *pkt = rcvdq.get ())
794 { 811 {
795 sockinfo si; 812 sockinfo si;
796 si.host = 0x01010101; si.port = htons (c->conf->id); si.prot = PROT_DNSv4; 813 si.host = htonl (c->conf->id); si.port = 0; si.prot = PROT_DNSv4;
797 814
798 vpn->recv_vpn_packet (pkt, si); 815 vpn->recv_vpn_packet (pkt, si);
799 816
800 delete pkt; 817 delete pkt;
801 } 818 }
… …
855 if (0 < client && client <= conns.size ()) 872 if (0 < client && client <= conns.size ())
856 { 873 {
857 connection *c = conns [client - 1]; 874 connection *c = conns [client - 1];
858 dns_connection *dns = c->dns; 875 dns_connection *dns = c->dns;
859 dns_rcv *rcv; 876 dns_rcv *rcv;
860 bool in_seq;
861 877
862 if (dns) 878 if (dns)
863 { 879 {
864 for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); ) 880 for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); )
865 if (SEQNO_EQ ((*i)->seqno, seqno)) 881 if (SEQNO_EQ ((*i)->seqno, seqno))
… …
876 memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len); 892 memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len);
877 893
878 goto duplicate_request; 894 goto duplicate_request;
879 } 895 }
880 896
881 in_seq = dns->rcvseq == seqno;
882
883 // new packet, queue 897 // new packet, queue
884 rcv = new dns_rcv (seqno, data, datalen); 898 rcv = new dns_rcv (seqno, data, datalen);
885 dns->receive_rep (rcv); 899 dns->receive_rep (rcv);
886 } 900 }
887 901
… …
894 pkt [offs++] = 0; pkt [offs++] = 0; 908 pkt [offs++] = 0; pkt [offs++] = 0;
895 pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL 909 pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL
896 910
897 int rdlen_offs = offs += 2; 911 int rdlen_offs = offs += 2;
898 912
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) 913 if (dns)
904 { 914 {
915 int dlen = ntohs (dns->cfg.max_size) - offs;
916
917 // bind doesn't compress well, so reduce further by one label length
918 dlen -= qlen;
919
905 // only put data into in-order sequence packets, if 920 // only put data into in-order sequence packets, if
906 // we receive out-of-order packets we generate empty 921 // we receive out-of-order packets we generate empty
907 // replies 922 // replies
908 while (dlen > 1 && !dns->snddq.empty () && in_seq) 923 //printf ("%d - %d & %x (=%d) < %d\n", seqno, dns->repseq, SEQNO_MASK, (seqno - dns->repseq) & SEQNO_MASK, MAX_WINDOW);//D
924 if (((seqno - dns->repseq) & SEQNO_MASK) <= MAX_WINDOW)
909 { 925 {
926 dns->repseq = seqno;
927
928 while (dlen > 1 && !dns->snddq.empty ())
929 {
910 int txtlen = dlen <= 255 ? dlen - 1 : 255; 930 int txtlen = dlen <= 255 ? dlen - 1 : 255;
911 931
912 if (txtlen > dns->snddq.size ()) 932 if (txtlen > dns->snddq.size ())
913 txtlen = dns->snddq.size (); 933 txtlen = dns->snddq.size ();
914 934
915 pkt[offs++] = txtlen; 935 pkt[offs++] = txtlen;
916 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen); 936 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
917 offs += txtlen; 937 offs += txtlen;
918 dns->snddq.remove (txtlen); 938 dns->snddq.remove (txtlen);
919 939
920 dlen -= txtlen + 1; 940 dlen -= txtlen + 1;
941 }
921 } 942 }
922 943
923 // avoid empty TXT rdata 944 // avoid completely empty TXT rdata
924 if (offs == rdlen_offs) 945 if (offs == rdlen_offs)
925 pkt[offs++] = 0; 946 pkt[offs++] = 0;
926 947
927 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ()); 948 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
928 } 949 }
… …
1008 { 1029 {
1009 dns_connection *dns = (*i)->dns; 1030 dns_connection *dns = (*i)->dns;
1010 connection *c = dns->c; 1031 connection *c = dns->c;
1011 int seqno = (*i)->seqno; 1032 int seqno = (*i)->seqno;
1012 u8 data[MAXSIZE], *datap = data; 1033 u8 data[MAXSIZE], *datap = data;
1034 //printf ("rcv pkt %x\n", seqno);//D
1013 1035
1014 if ((*i)->retry) 1036 if ((*i)->retry)
1015 { 1037 {
1016 dns->send_interval *= 1.01; 1038 dns->send_interval *= 1.01;
1017 if (dns->send_interval > MAX_SEND_INTERVAL) 1039 if (dns->send_interval > MAX_SEND_INTERVAL)
1018 dns->send_interval = MAX_SEND_INTERVAL; 1040 dns->send_interval = MAX_SEND_INTERVAL;
1019 } 1041 }
1020 else 1042 else
1021 { 1043 {
1022#if 1 1044#if 0
1023 dns->send_interval *= 0.999; 1045 dns->send_interval *= 0.999;
1024#endif 1046#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 1047 // the latency surely puts an upper bound on
1029 // the minimum send interval 1048 // the minimum send interval
1030 double latency = NOW - (*i)->sent; 1049 double latency = ev_now () - (*i)->sent;
1031 1050
1032 if (latency < dns->min_latency) 1051 if (latency < dns->min_latency)
1033 dns->min_latency = latency; 1052 dns->min_latency = latency;
1034 1053
1035 if (dns->send_interval > dns->min_latency * LATENCY_FACTOR) 1054 if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor)
1036 dns->send_interval = dns->min_latency * LATENCY_FACTOR; 1055 dns->send_interval = dns->min_latency * conf.dns_overlap_factor;
1056
1057 if (dns->send_interval < conf.dns_send_interval)
1058 dns->send_interval = conf.dns_send_interval;
1037 } 1059 }
1038 1060
1039 delete *i; 1061 delete *i;
1040 dns_sndpq.erase (i); 1062 dns_sndpq.erase (i);
1041 1063
… …
1146 break; 1168 break;
1147 } 1169 }
1148} 1170}
1149 1171
1150void 1172void
1151vpn::dnsv4_ev (io_watcher &w, short revents) 1173vpn::dnsv4_ev (ev::io &w, int revents)
1152{ 1174{
1153 if (revents & EVENT_READ) 1175 if (revents & EV_READ)
1154 { 1176 {
1155 dns_packet *pkt = new dns_packet; 1177 dns_packet *pkt = new dns_packet;
1156 struct sockaddr_in sa; 1178 struct sockaddr_in sa;
1157 socklen_t sa_len = sizeof (sa); 1179 socklen_t sa_len = sizeof (sa);
1158 1180
… …
1174} 1196}
1175 1197
1176bool 1198bool
1177vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) 1199vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
1178{ 1200{
1179 int client = ntohs (si.port); 1201 int client = ntohl (si.host);
1180 1202
1181 assert (0 < client && client <= conns.size ()); 1203 assert (0 < client && client <= conns.size ());
1182 1204
1183 connection *c = conns [client - 1]; 1205 connection *c = conns [client - 1];
1184 1206
1185 if (!c->dns) 1207 if (!c->dns)
1186 c->dns = new dns_connection (c); 1208 c->dns = new dns_connection (c);
1187 1209
1188 if (!c->dns->snddq.put (pkt)) 1210 if (c->dns->snddq.put (pkt))
1189 return false;
1190
1191 c->dns->tw.trigger (); 1211 c->dns->tw ();
1192 1212
1213 // always return true even if the buffer overflows
1193 return true; 1214 return true;
1194} 1215}
1195 1216
1196void 1217void
1197connection::dnsv4_reset_connection () 1218connection::dnsv4_reset_connection ()
… …
1200} 1221}
1201 1222
1202#define NEXT(w) do { if (next > (w)) next = w; } while (0) 1223#define NEXT(w) do { if (next > (w)) next = w; } while (0)
1203 1224
1204void 1225void
1205dns_connection::time_cb (time_watcher &w) 1226dns_connection::time_cb (ev::timer &w, int revents)
1206{ 1227{
1207 // servers have to be polled 1228 // servers have to be polled
1208 if (THISNODE->dns_port) 1229 if (THISNODE->dns_port)
1209 return; 1230 return;
1210 1231
1211 // check for timeouts and (re)transmit 1232 // check for timeouts and (re)transmit
1212 tstamp next = NOW + poll_interval; 1233 tstamp next = ev::now () + poll_interval;
1213 dns_snd *send = 0; 1234 dns_snd *send = 0;
1214 1235
1215 for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin (); 1236 for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin ();
1216 i != vpn->dns_sndpq.end (); 1237 i != vpn->dns_sndpq.end ();
1217 ++i) 1238 ++i)
1218 { 1239 {
1219 dns_snd *r = *i; 1240 dns_snd *r = *i;
1220 1241
1221 if (r->timeout <= NOW) 1242 if (r->timeout <= ev_now ())
1222 { 1243 {
1223 if (!send) 1244 if (!send)
1224 { 1245 {
1225 send = r; 1246 send = r;
1226 1247
1227 r->retry++; 1248 r->retry++;
1228 r->timeout = NOW + (r->retry * min_latency * 8.); 1249 r->timeout = ev_now () + (r->retry * min_latency * conf.dns_timeout_factor);
1250 //printf ("RETRY %x (%d, %f)\n", r->seqno, r->retry, r->timeout - ev_now ());//D
1229 1251
1230 // the following code changes the query section a bit, forcing 1252 // the following code changes the query section a bit, forcing
1231 // the forwarder to generate a new request 1253 // the forwarder to generate a new request
1232 if (r->stdhdr) 1254 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); 1255 encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry);
1236 }
1237 } 1256 }
1238 } 1257 }
1239 else 1258 else
1240 NEXT (r->timeout); 1259 NEXT (r->timeout);
1241 } 1260 }
1242 1261
1243 if (last_sent + send_interval <= NOW)
1244 {
1245 if (!send) 1262 if (!send)
1263 {
1264 // generate a new packet, if wise
1265
1266 if (!established)
1246 { 1267 {
1247 // generate a new packet, if wise 1268 if (vpn->dns_sndpq.empty ())
1248
1249 if (!established)
1250 { 1269 {
1251 if (vpn->dns_sndpq.empty ())
1252 {
1253 send = new dns_snd (this); 1270 send = new dns_snd (this);
1254 1271
1255 cfg.reset (THISNODE->id); 1272 cfg.reset (THISNODE->id);
1256 send->gen_syn_req (); 1273 send->gen_syn_req ();
1257 }
1258 } 1274 }
1259 else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING 1275 }
1276 else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding
1260 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) 1277 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
1278 {
1279 if (last_sent + send_interval <= ev_now ())
1261 { 1280 {
1262 //printf ("sending data request etc.\n"); //D 1281 //printf ("sending data request etc.\n"); //D
1263 if (!snddq.empty () || last_received + 1. > NOW) 1282 if (!snddq.empty () || last_received + 1. > ev_now ())
1264 { 1283 {
1265 poll_interval = send_interval; 1284 poll_interval = send_interval;
1266 NEXT (NOW + send_interval); 1285 NEXT (ev_now () + send_interval);
1267 } 1286 }
1268 1287
1269 send = new dns_snd (this); 1288 send = new dns_snd (this);
1270 send->gen_stream_req (sndseq, snddq); 1289 send->gen_stream_req (sndseq, snddq);
1271 send->timeout = NOW + min_latency * 8.; 1290 send->timeout = ev_now () + min_latency * conf.dns_timeout_factor;
1291 //printf ("SEND %x (%f)\n", send->seqno, send->timeout - ev_now (), min_latency, conf.dns_timeout_factor);//D
1272 1292
1273 sndseq = (sndseq + 1) & SEQNO_MASK; 1293 sndseq = (sndseq + 1) & SEQNO_MASK;
1274 } 1294 }
1275 1295 else
1276 if (send) 1296 NEXT (last_sent + send_interval);
1277 vpn->dns_sndpq.push_back (send);
1278 } 1297 }
1279 1298
1280 if (send) 1299 if (send)
1281 { 1300 vpn->dns_sndpq.push_back (send);
1282 last_sent = NOW; 1301 }
1302
1303 if (send)
1304 {
1305 last_sent = ev_now ();
1283 sendto (vpn->dnsv4_fd, 1306 sendto (vpn->dnsv4_fd,
1284 send->pkt->at (0), send->pkt->len, 0, 1307 send->pkt->at (0), send->pkt->len, 0,
1285 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); 1308 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
1286 }
1287 } 1309 }
1288 else
1289 NEXT (last_sent + send_interval);
1290 1310
1291 slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d)", 1311 slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)",
1292 poll_interval, send_interval, next - NOW, 1312 poll_interval, send_interval, next - ev_now (),
1293 vpn->dns_sndpq.size (), snddq.size ()); 1313 vpn->dns_sndpq.size (), snddq.size (),
1314 rcvpq.size ());
1294 1315
1295 // TODO: no idea when this happens, but when next < NOW, we have a problem 1316 // TODO: no idea when this happens, but when next < ev_now (), we have a problem
1317 // doesn't seem to happen anymore
1296 if (next < NOW + 0.0001) 1318 if (next < ev_now () + 0.001)
1297 next = NOW + 0.1; 1319 next = ev_now () + 0.1;
1298 1320
1299 w.start (next); 1321 w.start (next - ev_now ());
1300} 1322}
1301 1323
1302#endif 1324#endif
1303 1325

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