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/cvs/gvpe/src/vpn_dns.C
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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 1.27 by pcg, Sat Mar 12 18:10:40 2005 UTC

… …
52 52
53#define INITIAL_TIMEOUT 0.1 // retry timeouts 53#define INITIAL_TIMEOUT 0.1 // retry timeouts
54#define INITIAL_SYN_TIMEOUT 10. // retry timeout for initial syn 54#define INITIAL_SYN_TIMEOUT 10. // retry timeout for initial syn
55 55
56#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
57#define MAX_SEND_INTERVAL 0.5 // optimistic? 57#define MAX_SEND_INTERVAL 2. // optimistic?
58 58
59#define LATENCY_FACTOR 0.5 // RTT * LATENCY_FACTOR == sending rate
59#define MAX_OUTSTANDING 10 // max. outstanding requests 60#define MAX_OUTSTANDING 40 // max. outstanding requests
60#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog 61#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 62#define MAX_BACKLOG (100*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE
62 63
63#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
64// 240 leaves about 4 bytes of server reply data 65// 240 leaves about 4 bytes of server reply data
65// every two request bytes less give room for one reply byte 66// every two request bytes less give room for one reply byte
66 67
67#define SEQNO_MASK 0x3fff 68#define SEQNO_MASK 0x3fff
68#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) ) 69#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )
… …
448 flags = 0; 449 flags = 0;
449 def_ttl = 0; 450 def_ttl = 0;
450 seq_cdc = 26; 451 seq_cdc = 26;
451 req_cdc = 62; 452 req_cdc = 62;
452 rep_cdc = 0; 453 rep_cdc = 0;
453 max_size = ntohs (MAX_PKT_SIZE); 454 max_size = htons (MAX_PKT_SIZE);
454 client = ntohs (clientid); 455 client = htons (clientid);
455 uid = next_uid++; 456 uid = next_uid++;
456 457
457 r2 = r3 = r4 = 0; 458 r2 = r3 = r4 = 0;
458 r4 = r5 = r6 = r7 = 0; 459 r4 = r5 = r6 = r7 = 0;
459} 460}
… …
465 && id3 == 'P' 466 && id3 == 'P'
466 && id4 == 'E' 467 && id4 == 'E'
467 && seq_cdc == 26 468 && seq_cdc == 26
468 && req_cdc == 62 469 && req_cdc == 62
469 && rep_cdc == 0 470 && rep_cdc == 0
470 && version == 1 471 && version == 1;
471 && max_size == ntohs (MAX_PKT_SIZE);
472} 472}
473 473
474struct dns_packet : net_packet 474struct dns_packet : net_packet
475{ 475{
476 u16 id; 476 u16 id;
… …
547 547
548 bool established; 548 bool established;
549 549
550 tstamp last_received; 550 tstamp last_received;
551 tstamp last_sent; 551 tstamp last_sent;
552 double last_latency; 552 double min_latency;
553 double poll_interval, send_interval; 553 double poll_interval, send_interval;
554 554
555 vector<dns_rcv *> rcvpq; 555 vector<dns_rcv *> rcvpq;
556 556
557 byte_stream rcvdq; int rcvseq; 557 byte_stream rcvdq; int rcvseq;
… …
731 rcvseq = sndseq = 0; 731 rcvseq = sndseq = 0;
732 732
733 last_sent = last_received = 0; 733 last_sent = last_received = 0;
734 poll_interval = MIN_POLL_INTERVAL; 734 poll_interval = MIN_POLL_INTERVAL;
735 send_interval = 0.5; // starting rate 735 send_interval = 0.5; // starting rate
736 last_latency = INITIAL_TIMEOUT; 736 min_latency = INITIAL_TIMEOUT;
737} 737}
738 738
739dns_connection::~dns_connection () 739dns_connection::~dns_connection ()
740{ 740{
741 for (vector<dns_rcv *>::iterator i = rcvpq.begin (); 741 for (vector<dns_rcv *>::iterator i = rcvpq.begin ();
… …
754 poll_interval = send_interval; 754 poll_interval = send_interval;
755 } 755 }
756 else 756 else
757 { 757 {
758 poll_interval *= 1.5; 758 poll_interval *= 1.5;
759
759 if (poll_interval > MAX_POLL_INTERVAL) 760 if (poll_interval > MAX_POLL_INTERVAL)
760 poll_interval = MAX_POLL_INTERVAL; 761 poll_interval = MAX_POLL_INTERVAL;
761 } 762 }
762 763
763 rcvpq.push_back (r); 764 rcvpq.push_back (r);
… …
892 pkt [offs++] = 0; pkt [offs++] = 0; 893 pkt [offs++] = 0; pkt [offs++] = 0;
893 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
894 895
895 int rdlen_offs = offs += 2; 896 int rdlen_offs = offs += 2;
896 897
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) 898 if (dns)
902 { 899 {
900 int dlen = ntohs (dns->cfg.max_size) - offs;
901
902 // bind doesn't compress well, so reduce further by one label length
903 dlen -= qlen;
904
903 // only put data into in-order sequence packets, if 905 // only put data into in-order sequence packets, if
904 // we receive out-of-order packets we generate empty 906 // we receive out-of-order packets we generate empty
905 // replies 907 // replies
906 while (dlen > 1 && !dns->snddq.empty () && in_seq) 908 while (dlen > 1 && !dns->snddq.empty () && in_seq)
907 { 909 {
… …
1015 if (dns->send_interval > MAX_SEND_INTERVAL) 1017 if (dns->send_interval > MAX_SEND_INTERVAL)
1016 dns->send_interval = MAX_SEND_INTERVAL; 1018 dns->send_interval = MAX_SEND_INTERVAL;
1017 } 1019 }
1018 else 1020 else
1019 { 1021 {
1020#if 1 1022#if 0
1021 dns->send_interval *= 0.999; 1023 dns->send_interval *= 0.999;
1022#endif 1024#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 1025 // the latency surely puts an upper bound on
1027 // the minimum send interval 1026 // the minimum send interval
1028 double latency = NOW - (*i)->sent; 1027 double latency = NOW - (*i)->sent;
1028
1029 if (latency < dns->min_latency)
1029 dns->last_latency = latency; 1030 dns->min_latency = latency;
1030 1031
1031 if (dns->send_interval > latency) 1032 if (dns->send_interval > dns->min_latency * LATENCY_FACTOR)
1032 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;
1033 } 1037 }
1034 1038
1035 delete *i; 1039 delete *i;
1036 dns_sndpq.erase (i); 1040 dns_sndpq.erase (i);
1037 1041
… …
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 * 8.);
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) 1243 if (send || (last_sent + send_interval <= NOW))
1240 { 1244 {
1241 if (!send) 1245 if (!send)
1242 { 1246 {
1243 // generate a new packet, if wise 1247 // generate a new packet, if wise
1244 1248
… …
1254 } 1258 }
1255 else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING 1259 else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING
1256 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) 1260 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
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 * 8.;
1268 1272
1269 sndseq = (sndseq + 1) & SEQNO_MASK; 1273 sndseq = (sndseq + 1) & SEQNO_MASK;
1270 } 1274 }
1271 1275
1272 if (send) 1276 if (send && !send->retry)
1273 vpn->dns_sndpq.push_back (send); 1277 vpn->dns_sndpq.push_back (send);
1274 } 1278 }
1275 1279
1276 if (send) 1280 if (send)
1277 { 1281 {
… …
1282 } 1286 }
1283 } 1287 }
1284 else 1288 else
1285 NEXT (last_sent + send_interval); 1289 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
1292 if (next < NOW + 0.0001) 1297 if (next < NOW + 0.0001)
1293 next = NOW + 0.1; 1298 next = NOW + 0.1;
1294 1299

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