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/cvs/gvpe/src/vpn_dns.C
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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 1.30 by pcg, Mon Mar 14 17:40:01 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 10. // retry timeout for initial syn
55 54
56#define MIN_SEND_INTERVAL 0.01 // wait at least this time between sending requests 55#define MIN_SEND_INTERVAL 0.001 // wait at least this time between sending requests
57#define MAX_SEND_INTERVAL 0.5 // optimistic? 56#define MAX_SEND_INTERVAL 2. // optimistic?
58 57
59#define LATENCY_FACTOR 0.5 // RTT * LATENCY_FACTOR == sending rate 58#define LATENCY_FACTOR 0.5 // RTT * LATENCY_FACTOR == sending rate
60#define MAX_OUTSTANDING 20 // max. outstanding requests 59#define MAX_OUTSTANDING 2 // max. outstanding requests
61#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog 60#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 61#define MAX_BACKLOG (100*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE
63 62
64#define MAX_DOMAIN_SIZE 200 // 255 is legal limit, but bind doesn't compress well 63#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 64// 240 leaves about 4 bytes of server reply data
66// every two request bytes less give room for one reply byte 65// every two request bytes less give room for one reply byte
67 66
68#define SEQNO_MASK 0x3fff 67#define SEQNO_MASK 0x3fff
69#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) ) 68#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )
… …
424 u16 max_size; 423 u16 max_size;
425 u8 seq_cdc; 424 u8 seq_cdc;
426 u8 req_cdc; 425 u8 req_cdc;
427 426
428 u8 rep_cdc; 427 u8 rep_cdc;
428 u8 delay; // time in 0.01s units that the server may delay replying packets
429 u8 r2, r3, r4; 429 u8 r3, r4;
430 430
431 u8 r5, r6, r7, r8; 431 u8 r5, r6, r7, r8;
432 432
433 void reset (int clientid); 433 void reset (int clientid);
434 bool valid (); 434 bool valid ();
… …
449 flags = 0; 449 flags = 0;
450 def_ttl = 0; 450 def_ttl = 0;
451 seq_cdc = 26; 451 seq_cdc = 26;
452 req_cdc = 62; 452 req_cdc = 62;
453 rep_cdc = 0; 453 rep_cdc = 0;
454 max_size = ntohs (MAX_PKT_SIZE); 454 max_size = htons (MAX_PKT_SIZE);
455 client = ntohs (clientid); 455 client = htons (clientid);
456 uid = next_uid++; 456 uid = next_uid++;
457 delay = 0;
457 458
458 r2 = r3 = r4 = 0; 459 r3 = r4 = 0;
459 r4 = r5 = r6 = r7 = 0; 460 r4 = r5 = r6 = r7 = 0;
460} 461}
461 462
462bool dns_cfg::valid () 463bool dns_cfg::valid ()
463{ 464{
… …
466 && id3 == 'P' 467 && id3 == 'P'
467 && id4 == 'E' 468 && id4 == 'E'
468 && seq_cdc == 26 469 && seq_cdc == 26
469 && req_cdc == 62 470 && req_cdc == 62
470 && rep_cdc == 0 471 && rep_cdc == 0
471 && version == 1 472 && version == 1;
472 && max_size == ntohs (MAX_PKT_SIZE);
473} 473}
474 474
475struct dns_packet : net_packet 475struct dns_packet : net_packet
476{ 476{
477 u16 id; 477 u16 id;
… …
730 established = false; 730 established = false;
731 731
732 rcvseq = sndseq = 0; 732 rcvseq = sndseq = 0;
733 733
734 last_sent = last_received = 0; 734 last_sent = last_received = 0;
735 poll_interval = MIN_POLL_INTERVAL; 735 poll_interval = 0.5; // starting here
736 send_interval = 0.5; // starting rate 736 send_interval = 0.5; // starting rate
737 min_latency = INITIAL_TIMEOUT; 737 min_latency = INITIAL_TIMEOUT;
738} 738}
739 739
740dns_connection::~dns_connection () 740dns_connection::~dns_connection ()
… …
894 pkt [offs++] = 0; pkt [offs++] = 0; 894 pkt [offs++] = 0; pkt [offs++] = 0;
895 pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL 895 pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL
896 896
897 int rdlen_offs = offs += 2; 897 int rdlen_offs = offs += 2;
898 898
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) 899 if (dns)
904 { 900 {
901 int dlen = ntohs (dns->cfg.max_size) - offs;
902
903 // bind doesn't compress well, so reduce further by one label length
904 dlen -= qlen;
905
905 // only put data into in-order sequence packets, if 906 // only put data into in-order sequence packets, if
906 // we receive out-of-order packets we generate empty 907 // we receive out-of-order packets we generate empty
907 // replies 908 // replies
908 while (dlen > 1 && !dns->snddq.empty () && in_seq) 909 while (dlen > 1 && !dns->snddq.empty () && in_seq)
909 { 910 {
… …
1017 if (dns->send_interval > MAX_SEND_INTERVAL) 1018 if (dns->send_interval > MAX_SEND_INTERVAL)
1018 dns->send_interval = MAX_SEND_INTERVAL; 1019 dns->send_interval = MAX_SEND_INTERVAL;
1019 } 1020 }
1020 else 1021 else
1021 { 1022 {
1022#if 1 1023#if 0
1023 dns->send_interval *= 0.999; 1024 dns->send_interval *= 0.999;
1024#endif 1025#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 1026 // the latency surely puts an upper bound on
1029 // the minimum send interval 1027 // the minimum send interval
1030 double latency = NOW - (*i)->sent; 1028 double latency = NOW - (*i)->sent;
1031 1029
1032 if (latency < dns->min_latency) 1030 if (latency < dns->min_latency)
1033 dns->min_latency = latency; 1031 dns->min_latency = latency;
1034 1032
1035 if (dns->send_interval > dns->min_latency * LATENCY_FACTOR) 1033 if (dns->send_interval > dns->min_latency * LATENCY_FACTOR)
1036 dns->send_interval = dns->min_latency * LATENCY_FACTOR; 1034 dns->send_interval = dns->min_latency * LATENCY_FACTOR;
1035
1036 if (dns->send_interval < MIN_SEND_INTERVAL)
1037 dns->send_interval = MIN_SEND_INTERVAL;
1037 } 1038 }
1038 1039
1039 delete *i; 1040 delete *i;
1040 dns_sndpq.erase (i); 1041 dns_sndpq.erase (i);
1041 1042
… …
1229 1230
1230 // the following code changes the query section a bit, forcing 1231 // the following code changes the query section a bit, forcing
1231 // the forwarder to generate a new request 1232 // the forwarder to generate a new request
1232 if (r->stdhdr) 1233 if (r->stdhdr)
1233 { 1234 {
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 //printf ("reencoded header for ID %d retry %d:%d:%d (%p)\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); 1236 //encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry);
1236 } 1237 }
1237 } 1238 }
1238 } 1239 }
1239 else 1240 else
1240 NEXT (r->timeout); 1241 NEXT (r->timeout);
1241 } 1242 }
1242 1243
1243 if (last_sent + send_interval <= NOW)
1244 {
1245 if (!send) 1244 if (!send)
1245 {
1246 // generate a new packet, if wise
1247
1248 if (!established)
1246 { 1249 {
1247 // generate a new packet, if wise 1250 if (vpn->dns_sndpq.empty ())
1248
1249 if (!established)
1250 { 1251 {
1251 if (vpn->dns_sndpq.empty ())
1252 {
1253 send = new dns_snd (this); 1252 send = new dns_snd (this);
1254 1253
1255 cfg.reset (THISNODE->id); 1254 cfg.reset (THISNODE->id);
1256 send->gen_syn_req (); 1255 send->gen_syn_req ();
1257 }
1258 } 1256 }
1257 }
1259 else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING 1258 else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING
1260 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) 1259 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
1260 {
1261 if (last_sent + send_interval <= NOW)
1261 { 1262 {
1262 //printf ("sending data request etc.\n"); //D 1263 //printf ("sending data request etc.\n"); //D
1263 if (!snddq.empty () || last_received + 1. > NOW) 1264 if (!snddq.empty () || last_received + 1. > NOW)
1264 { 1265 {
1265 poll_interval = send_interval; 1266 poll_interval = send_interval;
… …
1270 send->gen_stream_req (sndseq, snddq); 1271 send->gen_stream_req (sndseq, snddq);
1271 send->timeout = NOW + min_latency * 8.; 1272 send->timeout = NOW + min_latency * 8.;
1272 1273
1273 sndseq = (sndseq + 1) & SEQNO_MASK; 1274 sndseq = (sndseq + 1) & SEQNO_MASK;
1274 } 1275 }
1275 1276 else
1276 if (send) 1277 NEXT (last_sent + send_interval);
1277 vpn->dns_sndpq.push_back (send);
1278 } 1278 }
1279 1279
1280 if (send) 1280 if (send)
1281 { 1281 vpn->dns_sndpq.push_back (send);
1282 }
1283
1284 if (send)
1285 {
1282 last_sent = NOW; 1286 last_sent = NOW;
1283 sendto (vpn->dnsv4_fd, 1287 sendto (vpn->dnsv4_fd,
1284 send->pkt->at (0), send->pkt->len, 0, 1288 send->pkt->at (0), send->pkt->len, 0,
1285 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); 1289 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
1286 }
1287 } 1290 }
1288 else
1289 NEXT (last_sent + send_interval);
1290 1291
1291 slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d)", 1292 slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)",
1292 poll_interval, send_interval, next - NOW, 1293 poll_interval, send_interval, next - NOW,
1293 vpn->dns_sndpq.size (), snddq.size ()); 1294 vpn->dns_sndpq.size (), snddq.size (),
1295 rcvpq.size ());
1294 1296
1295 // TODO: no idea when this happens, but when next < NOW, we have a problem 1297 // TODO: no idea when this happens, but when next < NOW, we have a problem
1296 if (next < NOW + 0.0001) 1298 if (next < NOW + 0.001)
1297 next = NOW + 0.1; 1299 next = NOW + 0.1;
1298 1300
1299 w.start (next); 1301 w.start (next);
1300} 1302}
1301 1303

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