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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 1.34 by pcg, Tue Mar 15 19:26:11 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.
51
52#define TIMEOUT_FACTOR 2.
52 53
53#define INITIAL_TIMEOUT 0.1 // retry timeouts 54#define INITIAL_TIMEOUT 0.1 // retry timeouts
54#define INITIAL_SYN_TIMEOUT 10. // retry timeout for initial syn 55#define INITIAL_SYN_TIMEOUT 10. // retry timeout for initial syn
55 56
56#define MIN_SEND_INTERVAL 0.01 // wait at least this time between sending requests 57#define MIN_SEND_INTERVAL 0.001 // wait at least this time between sending requests
57#define MAX_SEND_INTERVAL 0.5 // optimistic? 58#define MAX_SEND_INTERVAL 2. // optimistic?
58 59
60#define LATENCY_FACTOR 0.5 // RTT * LATENCY_FACTOR == sending rate
59#define MAX_OUTSTANDING 10 // max. outstanding requests 61#define MAX_OUTSTANDING 100 // max. outstanding requests
60#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog 62#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 63#define MAX_BACKLOG (32*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE
62 64
63#define MAX_DOMAIN_SIZE 220 // 255 is legal limit, but bind doesn't compress well 65#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 66// 240 leaves about 4 bytes of server reply data
65// every two request bytes less give room for one reply byte 67// every request byte less give room for two reply bytes
66 68
67#define SEQNO_MASK 0x3fff 69#define SEQNO_MASK 0x3fff
68#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) ) 70#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )
69 71
70#define MAX_LBL_SIZE 63 72#define MAX_LBL_SIZE 63
… …
423 u16 max_size; 425 u16 max_size;
424 u8 seq_cdc; 426 u8 seq_cdc;
425 u8 req_cdc; 427 u8 req_cdc;
426 428
427 u8 rep_cdc; 429 u8 rep_cdc;
430 u8 delay; // time in 0.01s units that the server may delay replying packets
428 u8 r2, r3, r4; 431 u8 r3, r4;
429 432
430 u8 r5, r6, r7, r8; 433 u8 r5, r6, r7, r8;
431 434
432 void reset (int clientid); 435 void reset (int clientid);
433 bool valid (); 436 bool valid ();
… …
448 flags = 0; 451 flags = 0;
449 def_ttl = 0; 452 def_ttl = 0;
450 seq_cdc = 26; 453 seq_cdc = 26;
451 req_cdc = 62; 454 req_cdc = 62;
452 rep_cdc = 0; 455 rep_cdc = 0;
453 max_size = ntohs (MAX_PKT_SIZE); 456 max_size = htons (MAX_PKT_SIZE);
454 client = ntohs (clientid); 457 client = htons (clientid);
455 uid = next_uid++; 458 uid = next_uid++;
459 delay = 0;
456 460
457 r2 = r3 = r4 = 0; 461 r3 = r4 = 0;
458 r4 = r5 = r6 = r7 = 0; 462 r4 = r5 = r6 = r7 = 0;
459} 463}
460 464
461bool dns_cfg::valid () 465bool dns_cfg::valid ()
462{ 466{
… …
465 && id3 == 'P' 469 && id3 == 'P'
466 && id4 == 'E' 470 && id4 == 'E'
467 && seq_cdc == 26 471 && seq_cdc == 26
468 && req_cdc == 62 472 && req_cdc == 62
469 && rep_cdc == 0 473 && rep_cdc == 0
470 && version == 1 474 && version == 1;
471 && max_size == ntohs (MAX_PKT_SIZE);
472} 475}
473 476
474struct dns_packet : net_packet 477struct dns_packet : net_packet
475{ 478{
476 u16 id; 479 u16 id;
… …
547 550
548 bool established; 551 bool established;
549 552
550 tstamp last_received; 553 tstamp last_received;
551 tstamp last_sent; 554 tstamp last_sent;
552 double last_latency; 555 double min_latency;
553 double poll_interval, send_interval; 556 double poll_interval, send_interval;
554 557
555 vector<dns_rcv *> rcvpq; 558 vector<dns_rcv *> rcvpq;
556 559
557 byte_stream rcvdq; int rcvseq; 560 byte_stream rcvdq; int rcvseq; int repseq;
558 byte_stream snddq; int sndseq; 561 byte_stream snddq; int sndseq;
559 562
560 void time_cb (time_watcher &w); time_watcher tw; 563 void time_cb (time_watcher &w); time_watcher tw;
561 void receive_rep (dns_rcv *r); 564 void receive_rep (dns_rcv *r);
562 565
… …
719///////////////////////////////////////////////////////////////////////////// 722/////////////////////////////////////////////////////////////////////////////
720 723
721dns_connection::dns_connection (connection *c) 724dns_connection::dns_connection (connection *c)
722: c (c) 725: c (c)
723, rcvdq (MAX_BACKLOG * 2) 726, rcvdq (MAX_BACKLOG * 2)
724, snddq (MAX_BACKLOG * 2) 727, snddq (MAX_BACKLOG)
725, tw (this, &dns_connection::time_cb) 728, tw (this, &dns_connection::time_cb)
726{ 729{
727 vpn = c->vpn; 730 vpn = c->vpn;
728 731
729 established = false; 732 established = false;
730 733
731 rcvseq = sndseq = 0; 734 rcvseq = repseq = sndseq = 0;
732 735
733 last_sent = last_received = 0; 736 last_sent = last_received = 0;
734 poll_interval = MIN_POLL_INTERVAL; 737 poll_interval = 0.5; // starting here
735 send_interval = 0.5; // starting rate 738 send_interval = 0.5; // starting rate
736 last_latency = INITIAL_TIMEOUT; 739 min_latency = INITIAL_TIMEOUT;
737} 740}
738 741
739dns_connection::~dns_connection () 742dns_connection::~dns_connection ()
740{ 743{
741 for (vector<dns_rcv *>::iterator i = rcvpq.begin (); 744 for (vector<dns_rcv *>::iterator i = rcvpq.begin ();
… …
754 poll_interval = send_interval; 757 poll_interval = send_interval;
755 } 758 }
756 else 759 else
757 { 760 {
758 poll_interval *= 1.5; 761 poll_interval *= 1.5;
762
759 if (poll_interval > MAX_POLL_INTERVAL) 763 if (poll_interval > MAX_POLL_INTERVAL)
760 poll_interval = MAX_POLL_INTERVAL; 764 poll_interval = MAX_POLL_INTERVAL;
761 } 765 }
762 766
763 rcvpq.push_back (r); 767 rcvpq.push_back (r);
… …
789 } 793 }
790 794
791 while (vpn_packet *pkt = rcvdq.get ()) 795 while (vpn_packet *pkt = rcvdq.get ())
792 { 796 {
793 sockinfo si; 797 sockinfo si;
794 si.host = 0x01010101; si.port = htons (c->conf->id); si.prot = PROT_DNSv4; 798 si.host = htonl (c->conf->id); si.port = 0; si.prot = PROT_DNSv4;
795 799
796 vpn->recv_vpn_packet (pkt, si); 800 vpn->recv_vpn_packet (pkt, si);
797 801
798 delete pkt; 802 delete pkt;
799 } 803 }
… …
853 if (0 < client && client <= conns.size ()) 857 if (0 < client && client <= conns.size ())
854 { 858 {
855 connection *c = conns [client - 1]; 859 connection *c = conns [client - 1];
856 dns_connection *dns = c->dns; 860 dns_connection *dns = c->dns;
857 dns_rcv *rcv; 861 dns_rcv *rcv;
858 bool in_seq;
859 862
860 if (dns) 863 if (dns)
861 { 864 {
862 for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); ) 865 for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); )
863 if (SEQNO_EQ ((*i)->seqno, seqno)) 866 if (SEQNO_EQ ((*i)->seqno, seqno))
… …
874 memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len); 877 memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len);
875 878
876 goto duplicate_request; 879 goto duplicate_request;
877 } 880 }
878 881
879 in_seq = dns->rcvseq == seqno;
880
881 // new packet, queue 882 // new packet, queue
882 rcv = new dns_rcv (seqno, data, datalen); 883 rcv = new dns_rcv (seqno, data, datalen);
883 dns->receive_rep (rcv); 884 dns->receive_rep (rcv);
884 } 885 }
885 886
… …
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 //printf ("%d - %d & %x (=%d) < %d\n", seqno, dns->repseq, SEQNO_MASK, (seqno - dns->repseq) & SEQNO_MASK, MAX_WINDOW);//D
909 if (((seqno - dns->repseq) & SEQNO_MASK) <= MAX_WINDOW)
907 { 910 {
911 dns->repseq = seqno;
912
913 while (dlen > 1 && !dns->snddq.empty ())
914 {
908 int txtlen = dlen <= 255 ? dlen - 1 : 255; 915 int txtlen = dlen <= 255 ? dlen - 1 : 255;
909 916
910 if (txtlen > dns->snddq.size ()) 917 if (txtlen > dns->snddq.size ())
911 txtlen = dns->snddq.size (); 918 txtlen = dns->snddq.size ();
912 919
913 pkt[offs++] = txtlen; 920 pkt[offs++] = txtlen;
914 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen); 921 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
915 offs += txtlen; 922 offs += txtlen;
916 dns->snddq.remove (txtlen); 923 dns->snddq.remove (txtlen);
917 924
918 dlen -= txtlen + 1; 925 dlen -= txtlen + 1;
926 }
919 } 927 }
920 928
921 // avoid empty TXT rdata 929 // avoid completely empty TXT rdata
922 if (offs == rdlen_offs) 930 if (offs == rdlen_offs)
923 pkt[offs++] = 0; 931 pkt[offs++] = 0;
924 932
925 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ()); 933 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
926 } 934 }
… …
1015 if (dns->send_interval > MAX_SEND_INTERVAL) 1023 if (dns->send_interval > MAX_SEND_INTERVAL)
1016 dns->send_interval = MAX_SEND_INTERVAL; 1024 dns->send_interval = MAX_SEND_INTERVAL;
1017 } 1025 }
1018 else 1026 else
1019 { 1027 {
1020#if 1 1028#if 0
1021 dns->send_interval *= 0.999; 1029 dns->send_interval *= 0.999;
1022#endif 1030#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 1031 // the latency surely puts an upper bound on
1027 // the minimum send interval 1032 // the minimum send interval
1028 double latency = NOW - (*i)->sent; 1033 double latency = NOW - (*i)->sent;
1034
1035 if (latency < dns->min_latency)
1029 dns->last_latency = latency; 1036 dns->min_latency = latency;
1030 1037
1031 if (dns->send_interval > latency) 1038 if (dns->send_interval > dns->min_latency * LATENCY_FACTOR)
1032 dns->send_interval = latency; 1039 dns->send_interval = dns->min_latency * LATENCY_FACTOR;
1040
1041 if (dns->send_interval < MIN_SEND_INTERVAL)
1042 dns->send_interval = MIN_SEND_INTERVAL;
1033 } 1043 }
1034 1044
1035 delete *i; 1045 delete *i;
1036 dns_sndpq.erase (i); 1046 dns_sndpq.erase (i);
1037 1047
… …
1170} 1180}
1171 1181
1172bool 1182bool
1173vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) 1183vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
1174{ 1184{
1175 int client = ntohs (si.port); 1185 int client = ntohl (si.host);
1176 1186
1177 assert (0 < client && client <= conns.size ()); 1187 assert (0 < client && client <= conns.size ());
1178 1188
1179 connection *c = conns [client - 1]; 1189 connection *c = conns [client - 1];
1180 1190
1181 if (!c->dns) 1191 if (!c->dns)
1182 c->dns = new dns_connection (c); 1192 c->dns = new dns_connection (c);
1183 1193
1184 if (!c->dns->snddq.put (pkt)) 1194 if (c->dns->snddq.put (pkt))
1185 return false;
1186
1187 c->dns->tw.trigger (); 1195 c->dns->tw.trigger ();
1188 1196
1197 // always return true even if the buffer overflows
1189 return true; 1198 return true;
1190} 1199}
1191 1200
1192void 1201void
1193connection::dnsv4_reset_connection () 1202connection::dnsv4_reset_connection ()
… …
1219 if (!send) 1228 if (!send)
1220 { 1229 {
1221 send = r; 1230 send = r;
1222 1231
1223 r->retry++; 1232 r->retry++;
1224 r->timeout = NOW + (r->retry * last_latency * 8.); 1233 r->timeout = NOW + (r->retry * min_latency * TIMEOUT_FACTOR);
1225 1234
1226 // the following code changes the query section a bit, forcing 1235 // the following code changes the query section a bit, forcing
1227 // the forwarder to generate a new request 1236 // the forwarder to generate a new request
1228 if (r->stdhdr) 1237 if (r->stdhdr)
1229 { 1238 {
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); 1239 //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); 1240 //encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry);
1232 } 1241 }
1233 } 1242 }
1234 } 1243 }
1235 else 1244 else
1236 NEXT (r->timeout); 1245 NEXT (r->timeout);
1237 } 1246 }
1238 1247
1239 if (last_sent + send_interval <= NOW)
1240 {
1241 if (!send) 1248 if (!send)
1249 {
1250 // generate a new packet, if wise
1251
1252 if (!established)
1242 { 1253 {
1243 // generate a new packet, if wise 1254 if (vpn->dns_sndpq.empty ())
1244
1245 if (!established)
1246 { 1255 {
1247 if (vpn->dns_sndpq.empty ())
1248 {
1249 send = new dns_snd (this); 1256 send = new dns_snd (this);
1250 1257
1251 cfg.reset (THISNODE->id); 1258 cfg.reset (THISNODE->id);
1252 send->gen_syn_req (); 1259 send->gen_syn_req ();
1253 }
1254 } 1260 }
1261 }
1255 else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING 1262 else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING
1256 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) 1263 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
1264 {
1265 if (last_sent + send_interval <= NOW)
1257 { 1266 {
1258 //printf ("sending data request etc.\n"); //D 1267 //printf ("sending data request etc.\n"); //D
1259 if (!snddq.empty ()) 1268 if (!snddq.empty () || last_received + 1. > NOW)
1260 { 1269 {
1261 poll_interval = send_interval; 1270 poll_interval = send_interval;
1262 NEXT (NOW + send_interval); 1271 NEXT (NOW + send_interval);
1263 } 1272 }
1264 1273
1265 send = new dns_snd (this); 1274 send = new dns_snd (this);
1266 send->gen_stream_req (sndseq, snddq); 1275 send->gen_stream_req (sndseq, snddq);
1267 send->timeout = NOW + last_latency * 8.; 1276 send->timeout = NOW + min_latency * TIMEOUT_FACTOR;
1268 1277
1269 sndseq = (sndseq + 1) & SEQNO_MASK; 1278 sndseq = (sndseq + 1) & SEQNO_MASK;
1270 } 1279 }
1271 1280 else
1272 if (send) 1281 NEXT (last_sent + send_interval);
1273 vpn->dns_sndpq.push_back (send);
1274 } 1282 }
1275 1283
1276 if (send) 1284 if (send)
1277 { 1285 vpn->dns_sndpq.push_back (send);
1286 }
1287
1288 if (send)
1289 {
1278 last_sent = NOW; 1290 last_sent = NOW;
1279 sendto (vpn->dnsv4_fd, 1291 sendto (vpn->dnsv4_fd,
1280 send->pkt->at (0), send->pkt->len, 0, 1292 send->pkt->at (0), send->pkt->len, 0,
1281 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); 1293 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
1282 }
1283 } 1294 }
1284 else
1285 NEXT (last_sent + send_interval);
1286 1295
1287 slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d)", 1296 slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)",
1288 poll_interval, send_interval, next - NOW, 1297 poll_interval, send_interval, next - NOW,
1289 vpn->dns_sndpq.size (), snddq.size ()); 1298 vpn->dns_sndpq.size (), snddq.size (),
1299 rcvpq.size ());
1290 1300
1291 // TODO: no idea when this happens, but when next < NOW, we have a problem 1301 // TODO: no idea when this happens, but when next < NOW, we have a problem
1292 if (next < NOW + 0.0001) 1302 if (next < NOW + 0.001)
1293 next = NOW + 0.1; 1303 next = NOW + 0.1;
1294 1304
1295 w.start (next); 1305 w.start (next);
1296} 1306}
1297 1307

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