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Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.24 by pcg, Mon Mar 7 01:31:26 2005 UTC vs.
Revision 1.37 by pcg, Wed Mar 23 17:03:58 2005 UTC

… …
44 44
45#include "netcompat.h" 45#include "netcompat.h"
46 46
47#include "vpn.h" 47#include "vpn.h"
48 48
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 49#define MAX_POLL_INTERVAL 5. // how often to poll minimally when the server has no data
51#define ACTIVITY_INTERVAL 5. 50#define ACTIVITY_INTERVAL 5.
52 51
53#define INITIAL_TIMEOUT 0.1 // retry timeouts 52#define INITIAL_TIMEOUT 0.1 // retry timeouts
54#define INITIAL_SYN_TIMEOUT 10. // retry timeout for initial syn 53#define INITIAL_SYN_TIMEOUT 2. // retry timeout for initial syn
55 54
56#define MIN_SEND_INTERVAL 0.01 // wait at least this time between sending requests
57#define MAX_SEND_INTERVAL 0.5 // optimistic? 55#define MAX_SEND_INTERVAL 2. // optimistic?
58 56
59#define MAX_OUTSTANDING 10 // max. outstanding requests
60#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog 57#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog
61#define MAX_BACKLOG (100*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE 58#define MAX_BACKLOG (64*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE
62 59
63#define MAX_DOMAIN_SIZE 220 // 255 is legal limit, but bind doesn't compress well 60#define MAX_DOMAIN_SIZE 240 // 255 is legal limit, but bind doesn't compress well
64// 240 leaves about 4 bytes of server reply data 61// 240 leaves about 4 bytes of server reply data
65// every two request bytes less give room for one reply byte 62// every request byte less give room for two reply bytes
66 63
67#define SEQNO_MASK 0x3fff 64#define SEQNO_MASK 0x3fff
68#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) ) 65#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )
69 66
70#define MAX_LBL_SIZE 63 67#define MAX_LBL_SIZE 63
… …
423 u16 max_size; 420 u16 max_size;
424 u8 seq_cdc; 421 u8 seq_cdc;
425 u8 req_cdc; 422 u8 req_cdc;
426 423
427 u8 rep_cdc; 424 u8 rep_cdc;
425 u8 delay; // time in 0.01s units that the server may delay replying packets
428 u8 r2, r3, r4; 426 u8 r3, r4;
429 427
430 u8 r5, r6, r7, r8; 428 u8 r5, r6, r7, r8;
431 429
432 void reset (int clientid); 430 void reset (int clientid);
433 bool valid (); 431 bool valid ();
… …
448 flags = 0; 446 flags = 0;
449 def_ttl = 0; 447 def_ttl = 0;
450 seq_cdc = 26; 448 seq_cdc = 26;
451 req_cdc = 62; 449 req_cdc = 62;
452 rep_cdc = 0; 450 rep_cdc = 0;
453 max_size = ntohs (MAX_PKT_SIZE); 451 max_size = htons (MAX_PKT_SIZE);
454 client = ntohs (clientid); 452 client = htons (clientid);
455 uid = next_uid++; 453 uid = next_uid++;
454 delay = 0;
456 455
457 r2 = r3 = r4 = 0; 456 r3 = r4 = 0;
458 r4 = r5 = r6 = r7 = 0; 457 r4 = r5 = r6 = r7 = 0;
459} 458}
460 459
461bool dns_cfg::valid () 460bool dns_cfg::valid ()
462{ 461{
… …
465 && id3 == 'P' 464 && id3 == 'P'
466 && id4 == 'E' 465 && id4 == 'E'
467 && seq_cdc == 26 466 && seq_cdc == 26
468 && req_cdc == 62 467 && req_cdc == 62
469 && rep_cdc == 0 468 && rep_cdc == 0
470 && version == 1 469 && version == 1;
471 && max_size == ntohs (MAX_PKT_SIZE);
472} 470}
473 471
474struct dns_packet : net_packet 472struct dns_packet : net_packet
475{ 473{
476 u16 id; 474 u16 id;
… …
547 545
548 bool established; 546 bool established;
549 547
550 tstamp last_received; 548 tstamp last_received;
551 tstamp last_sent; 549 tstamp last_sent;
552 double last_latency; 550 double min_latency;
553 double poll_interval, send_interval; 551 double poll_interval, send_interval;
554 552
555 vector<dns_rcv *> rcvpq; 553 vector<dns_rcv *> rcvpq;
556 554
557 byte_stream rcvdq; int rcvseq; 555 byte_stream rcvdq; int rcvseq; int repseq;
558 byte_stream snddq; int sndseq; 556 byte_stream snddq; int sndseq;
559 557
560 void time_cb (time_watcher &w); time_watcher tw; 558 void time_cb (time_watcher &w); time_watcher tw;
561 void receive_rep (dns_rcv *r); 559 void receive_rep (dns_rcv *r);
562 560
… …
719///////////////////////////////////////////////////////////////////////////// 717/////////////////////////////////////////////////////////////////////////////
720 718
721dns_connection::dns_connection (connection *c) 719dns_connection::dns_connection (connection *c)
722: c (c) 720: c (c)
723, rcvdq (MAX_BACKLOG * 2) 721, rcvdq (MAX_BACKLOG * 2)
724, snddq (MAX_BACKLOG * 2) 722, snddq (MAX_BACKLOG)
725, tw (this, &dns_connection::time_cb) 723, tw (this, &dns_connection::time_cb)
726{ 724{
727 vpn = c->vpn; 725 vpn = c->vpn;
728 726
729 established = false; 727 established = false;
730 728
731 rcvseq = sndseq = 0; 729 rcvseq = repseq = sndseq = 0;
732 730
733 last_sent = last_received = 0; 731 last_sent = last_received = 0;
734 poll_interval = MIN_POLL_INTERVAL; 732 poll_interval = 0.5; // starting here
735 send_interval = 0.5; // starting rate 733 send_interval = 0.5; // starting rate
736 last_latency = INITIAL_TIMEOUT; 734 min_latency = INITIAL_TIMEOUT;
737} 735}
738 736
739dns_connection::~dns_connection () 737dns_connection::~dns_connection ()
740{ 738{
741 for (vector<dns_rcv *>::iterator i = rcvpq.begin (); 739 for (vector<dns_rcv *>::iterator i = rcvpq.begin ();
… …
754 poll_interval = send_interval; 752 poll_interval = send_interval;
755 } 753 }
756 else 754 else
757 { 755 {
758 poll_interval *= 1.5; 756 poll_interval *= 1.5;
757
759 if (poll_interval > MAX_POLL_INTERVAL) 758 if (poll_interval > MAX_POLL_INTERVAL)
760 poll_interval = MAX_POLL_INTERVAL; 759 poll_interval = MAX_POLL_INTERVAL;
761 } 760 }
762 761
763 rcvpq.push_back (r); 762 rcvpq.push_back (r);
… …
789 } 788 }
790 789
791 while (vpn_packet *pkt = rcvdq.get ()) 790 while (vpn_packet *pkt = rcvdq.get ())
792 { 791 {
793 sockinfo si; 792 sockinfo si;
794 si.host = 0x01010101; si.port = htons (c->conf->id); si.prot = PROT_DNSv4; 793 si.host = htonl (c->conf->id); si.port = 0; si.prot = PROT_DNSv4;
795 794
796 vpn->recv_vpn_packet (pkt, si); 795 vpn->recv_vpn_packet (pkt, si);
797 796
798 delete pkt; 797 delete pkt;
799 } 798 }
… …
853 if (0 < client && client <= conns.size ()) 852 if (0 < client && client <= conns.size ())
854 { 853 {
855 connection *c = conns [client - 1]; 854 connection *c = conns [client - 1];
856 dns_connection *dns = c->dns; 855 dns_connection *dns = c->dns;
857 dns_rcv *rcv; 856 dns_rcv *rcv;
858 bool in_seq;
859 857
860 if (dns) 858 if (dns)
861 { 859 {
862 for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); ) 860 for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); )
863 if (SEQNO_EQ ((*i)->seqno, seqno)) 861 if (SEQNO_EQ ((*i)->seqno, seqno))
… …
874 memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len); 872 memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len);
875 873
876 goto duplicate_request; 874 goto duplicate_request;
877 } 875 }
878 876
879 in_seq = dns->rcvseq == seqno;
880
881 // new packet, queue 877 // new packet, queue
882 rcv = new dns_rcv (seqno, data, datalen); 878 rcv = new dns_rcv (seqno, data, datalen);
883 dns->receive_rep (rcv); 879 dns->receive_rep (rcv);
884 } 880 }
885 881
… …
892 pkt [offs++] = 0; pkt [offs++] = 0; 888 pkt [offs++] = 0; pkt [offs++] = 0;
893 pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL 889 pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL
894 890
895 int rdlen_offs = offs += 2; 891 int rdlen_offs = offs += 2;
896 892
897 int dlen = (dns ? ntohs (dns->cfg.max_size) : MAX_PKT_SIZE) - offs;
898 // bind doesn't compress well, so reduce further by one label length
899 dlen -= qlen;
900
901 if (dns) 893 if (dns)
902 { 894 {
895 int dlen = ntohs (dns->cfg.max_size) - offs;
896
897 // bind doesn't compress well, so reduce further by one label length
898 dlen -= qlen;
899
903 // only put data into in-order sequence packets, if 900 // only put data into in-order sequence packets, if
904 // we receive out-of-order packets we generate empty 901 // we receive out-of-order packets we generate empty
905 // replies 902 // replies
906 while (dlen > 1 && !dns->snddq.empty () && in_seq) 903 //printf ("%d - %d & %x (=%d) < %d\n", seqno, dns->repseq, SEQNO_MASK, (seqno - dns->repseq) & SEQNO_MASK, MAX_WINDOW);//D
904 if (((seqno - dns->repseq) & SEQNO_MASK) <= MAX_WINDOW)
907 { 905 {
906 dns->repseq = seqno;
907
908 while (dlen > 1 && !dns->snddq.empty ())
909 {
908 int txtlen = dlen <= 255 ? dlen - 1 : 255; 910 int txtlen = dlen <= 255 ? dlen - 1 : 255;
909 911
910 if (txtlen > dns->snddq.size ()) 912 if (txtlen > dns->snddq.size ())
911 txtlen = dns->snddq.size (); 913 txtlen = dns->snddq.size ();
912 914
913 pkt[offs++] = txtlen; 915 pkt[offs++] = txtlen;
914 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen); 916 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
915 offs += txtlen; 917 offs += txtlen;
916 dns->snddq.remove (txtlen); 918 dns->snddq.remove (txtlen);
917 919
918 dlen -= txtlen + 1; 920 dlen -= txtlen + 1;
921 }
919 } 922 }
920 923
921 // avoid empty TXT rdata 924 // avoid completely empty TXT rdata
922 if (offs == rdlen_offs) 925 if (offs == rdlen_offs)
923 pkt[offs++] = 0; 926 pkt[offs++] = 0;
924 927
925 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ()); 928 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
926 } 929 }
… …
1015 if (dns->send_interval > MAX_SEND_INTERVAL) 1018 if (dns->send_interval > MAX_SEND_INTERVAL)
1016 dns->send_interval = MAX_SEND_INTERVAL; 1019 dns->send_interval = MAX_SEND_INTERVAL;
1017 } 1020 }
1018 else 1021 else
1019 { 1022 {
1020#if 1 1023#if 0
1021 dns->send_interval *= 0.999; 1024 dns->send_interval *= 0.999;
1022#endif 1025#endif
1023 if (dns->send_interval < MIN_SEND_INTERVAL)
1024 dns->send_interval = MIN_SEND_INTERVAL;
1025
1026 // the latency surely puts an upper bound on 1026 // the latency surely puts an upper bound on
1027 // the minimum send interval 1027 // the minimum send interval
1028 double latency = NOW - (*i)->sent; 1028 double latency = NOW - (*i)->sent;
1029
1030 if (latency < dns->min_latency)
1029 dns->last_latency = latency; 1031 dns->min_latency = latency;
1030 1032
1031 if (dns->send_interval > latency) 1033 if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor)
1034 dns->send_interval = dns->min_latency * conf.dns_overlap_factor;
1035
1036 if (dns->send_interval < conf.dns_send_interval)
1032 dns->send_interval = latency; 1037 dns->send_interval = conf.dns_send_interval;
1033 } 1038 }
1034 1039
1035 delete *i; 1040 delete *i;
1036 dns_sndpq.erase (i); 1041 dns_sndpq.erase (i);
1037 1042
… …
1170} 1175}
1171 1176
1172bool 1177bool
1173vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) 1178vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
1174{ 1179{
1175 int client = ntohs (si.port); 1180 int client = ntohl (si.host);
1176 1181
1177 assert (0 < client && client <= conns.size ()); 1182 assert (0 < client && client <= conns.size ());
1178 1183
1179 connection *c = conns [client - 1]; 1184 connection *c = conns [client - 1];
1180 1185
1181 if (!c->dns) 1186 if (!c->dns)
1182 c->dns = new dns_connection (c); 1187 c->dns = new dns_connection (c);
1183 1188
1184 if (!c->dns->snddq.put (pkt)) 1189 if (c->dns->snddq.put (pkt))
1185 return false;
1186
1187 c->dns->tw.trigger (); 1190 c->dns->tw.trigger ();
1188 1191
1192 // always return true even if the buffer overflows
1189 return true; 1193 return true;
1190} 1194}
1191 1195
1192void 1196void
1193connection::dnsv4_reset_connection () 1197connection::dnsv4_reset_connection ()
… …
1219 if (!send) 1223 if (!send)
1220 { 1224 {
1221 send = r; 1225 send = r;
1222 1226
1223 r->retry++; 1227 r->retry++;
1224 r->timeout = NOW + (r->retry * last_latency * 8.); 1228 r->timeout = NOW + (r->retry * min_latency * conf.dns_timeout_factor);
1225 1229
1226 // the following code changes the query section a bit, forcing 1230 // the following code changes the query section a bit, forcing
1227 // the forwarder to generate a new request 1231 // the forwarder to generate a new request
1228 if (r->stdhdr) 1232 if (r->stdhdr)
1229 { 1233 {
1230 //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);
1231 //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);
1232 } 1236 }
1233 } 1237 }
1234 } 1238 }
1235 else 1239 else
1236 NEXT (r->timeout); 1240 NEXT (r->timeout);
1237 } 1241 }
1238 1242
1239 if (last_sent + send_interval <= NOW)
1240 {
1241 if (!send) 1243 if (!send)
1244 {
1245 // generate a new packet, if wise
1246
1247 if (!established)
1242 { 1248 {
1243 // generate a new packet, if wise 1249 if (vpn->dns_sndpq.empty ())
1244
1245 if (!established)
1246 { 1250 {
1247 if (vpn->dns_sndpq.empty ())
1248 {
1249 send = new dns_snd (this); 1251 send = new dns_snd (this);
1250 1252
1251 cfg.reset (THISNODE->id); 1253 cfg.reset (THISNODE->id);
1252 send->gen_syn_req (); 1254 send->gen_syn_req ();
1253 }
1254 } 1255 }
1255 else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING 1256 }
1257 else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding
1256 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) 1258 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
1259 {
1260 if (last_sent + send_interval <= NOW)
1257 { 1261 {
1258 //printf ("sending data request etc.\n"); //D 1262 //printf ("sending data request etc.\n"); //D
1259 if (!snddq.empty ()) 1263 if (!snddq.empty () || last_received + 1. > NOW)
1260 { 1264 {
1261 poll_interval = send_interval; 1265 poll_interval = send_interval;
1262 NEXT (NOW + send_interval); 1266 NEXT (NOW + send_interval);
1263 } 1267 }
1264 1268
1265 send = new dns_snd (this); 1269 send = new dns_snd (this);
1266 send->gen_stream_req (sndseq, snddq); 1270 send->gen_stream_req (sndseq, snddq);
1267 send->timeout = NOW + last_latency * 8.; 1271 send->timeout = NOW + min_latency * conf.dns_timeout_factor;
1268 1272
1269 sndseq = (sndseq + 1) & SEQNO_MASK; 1273 sndseq = (sndseq + 1) & SEQNO_MASK;
1270 } 1274 }
1271 1275 else
1272 if (send) 1276 NEXT (last_sent + send_interval);
1273 vpn->dns_sndpq.push_back (send);
1274 } 1277 }
1275 1278
1276 if (send) 1279 if (send)
1277 { 1280 vpn->dns_sndpq.push_back (send);
1281 }
1282
1283 if (send)
1284 {
1278 last_sent = NOW; 1285 last_sent = NOW;
1279 sendto (vpn->dnsv4_fd, 1286 sendto (vpn->dnsv4_fd,
1280 send->pkt->at (0), send->pkt->len, 0, 1287 send->pkt->at (0), send->pkt->len, 0,
1281 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); 1288 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
1282 }
1283 } 1289 }
1284 else
1285 NEXT (last_sent + send_interval);
1286 1290
1287 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)",
1288 poll_interval, send_interval, next - NOW, 1292 poll_interval, send_interval, next - NOW,
1289 vpn->dns_sndpq.size (), snddq.size ()); 1293 vpn->dns_sndpq.size (), snddq.size (),
1294 rcvpq.size ());
1290 1295
1291 // 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
1297 // doesn't seem to happen anymore
1292 if (next < NOW + 0.0001) 1298 if (next < NOW + 0.001)
1293 next = NOW + 0.1; 1299 next = NOW + 0.1;
1294 1300
1295 w.start (next); 1301 w.start (next);
1296} 1302}
1297 1303

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