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Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.23 by pcg, Sun Mar 6 21:52:15 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) )
… …
265static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO"); 266static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO");
266 267
267///////////////////////////////////////////////////////////////////////////// 268/////////////////////////////////////////////////////////////////////////////
268 269
269#define HDRSIZE 6 270#define HDRSIZE 6
270 271
271inline void encode_header (char *data, int clientid, int seqno, int retry = 0) 272inline void encode_header (char *data, int clientid, int seqno, int retry = 0)
272{ 273{
273 seqno &= SEQNO_MASK; 274 seqno &= SEQNO_MASK;
274 275
275 u8 hdr[3] = { 276 u8 hdr[3] = {
… …
409struct dns_cfg 410struct dns_cfg
410{ 411{
411 static int next_uid; 412 static int next_uid;
412 413
413 u8 id1, id2, id3, id4; 414 u8 id1, id2, id3, id4;
415
414 u8 version; 416 u8 version;
417 u8 flags;
415 u8 rrtype; 418 u8 rrtype;
416 u8 flags;
417 u8 def_ttl; 419 u8 def_ttl;
418 u8 rcv_cdc; 420
419 u8 snd_cdc;
420 u16 max_size;
421 u16 client; 421 u16 client;
422 u16 uid; // to make request unique 422 u16 uid; // to make request unique
423 423
424 u8 reserved[8]; 424 u16 max_size;
425 u8 seq_cdc;
426 u8 req_cdc;
427
428 u8 rep_cdc;
429 u8 r2, r3, r4;
430
431 u8 r5, r6, r7, r8;
425 432
426 void reset (int clientid); 433 void reset (int clientid);
427 bool valid (); 434 bool valid ();
428}; 435};
429 436
… …
438 445
439 version = 1; 446 version = 1;
440 447
441 rrtype = RR_TYPE_TXT; 448 rrtype = RR_TYPE_TXT;
442 flags = 0; 449 flags = 0;
443 def_ttl = 1; 450 def_ttl = 0;
451 seq_cdc = 26;
452 req_cdc = 62;
444 rcv_cdc = 0; 453 rep_cdc = 0;
445 snd_cdc = 62;
446 max_size = ntohs (MAX_PKT_SIZE); 454 max_size = htons (MAX_PKT_SIZE);
447 client = ntohs (clientid); 455 client = htons (clientid);
448 uid = next_uid++; 456 uid = next_uid++;
449 457
450 memset (reserved, 0, 8); 458 r2 = r3 = r4 = 0;
459 r4 = r5 = r6 = r7 = 0;
451} 460}
452 461
453bool dns_cfg::valid () 462bool dns_cfg::valid ()
454{ 463{
455 return id1 == 'G' 464 return id1 == 'G'
456 && id2 == 'V' 465 && id2 == 'V'
457 && id3 == 'P' 466 && id3 == 'P'
458 && id4 == 'E' 467 && id4 == 'E'
468 && seq_cdc == 26
469 && req_cdc == 62
470 && rep_cdc == 0
459 && version == 1 471 && version == 1;
460 && flags == 0
461 && rcv_cdc == 0
462 && snd_cdc == 62
463 && max_size == ntohs (MAX_PKT_SIZE);
464} 472}
465 473
466struct dns_packet : net_packet 474struct dns_packet : net_packet
467{ 475{
468 u16 id; 476 u16 id;
469 u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4 477 u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4
470 u16 qdcount, ancount, nscount, arcount; 478 u16 qdcount, ancount, nscount, arcount;
471 479
472 u8 data[MAXSIZE - 6 * 2]; 480 u8 data [MAXSIZE - 6 * 2];
473 481
474 int decode_label (char *data, int size, int &offs); 482 int decode_label (char *data, int size, int &offs);
475}; 483};
476 484
477int dns_packet::decode_label (char *data, int size, int &offs) 485int dns_packet::decode_label (char *data, int size, int &offs)
… …
539 547
540 bool established; 548 bool established;
541 549
542 tstamp last_received; 550 tstamp last_received;
543 tstamp last_sent; 551 tstamp last_sent;
544 double last_latency; 552 double min_latency;
545 double poll_interval, send_interval; 553 double poll_interval, send_interval;
546 554
547 vector<dns_rcv *> rcvpq; 555 vector<dns_rcv *> rcvpq;
548 556
549 byte_stream rcvdq; int rcvseq; 557 byte_stream rcvdq; int rcvseq;
… …
723 rcvseq = sndseq = 0; 731 rcvseq = sndseq = 0;
724 732
725 last_sent = last_received = 0; 733 last_sent = last_received = 0;
726 poll_interval = MIN_POLL_INTERVAL; 734 poll_interval = MIN_POLL_INTERVAL;
727 send_interval = 0.5; // starting rate 735 send_interval = 0.5; // starting rate
728 last_latency = INITIAL_TIMEOUT; 736 min_latency = INITIAL_TIMEOUT;
729} 737}
730 738
731dns_connection::~dns_connection () 739dns_connection::~dns_connection ()
732{ 740{
733 for (vector<dns_rcv *>::iterator i = rcvpq.begin (); 741 for (vector<dns_rcv *>::iterator i = rcvpq.begin ();
… …
746 poll_interval = send_interval; 754 poll_interval = send_interval;
747 } 755 }
748 else 756 else
749 { 757 {
750 poll_interval *= 1.5; 758 poll_interval *= 1.5;
759
751 if (poll_interval > MAX_POLL_INTERVAL) 760 if (poll_interval > MAX_POLL_INTERVAL)
752 poll_interval = MAX_POLL_INTERVAL; 761 poll_interval = MAX_POLL_INTERVAL;
753 } 762 }
754 763
755 rcvpq.push_back (r); 764 rcvpq.push_back (r);
… …
805 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR); 814 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR);
806 815
807 if (0 == (flags & (FLAG_RESPONSE | FLAG_OP_MASK)) 816 if (0 == (flags & (FLAG_RESPONSE | FLAG_OP_MASK))
808 && pkt.qdcount == htons (1)) 817 && pkt.qdcount == htons (1))
809 { 818 {
810 char qname[MAXSIZE]; 819 char qname [MAXSIZE];
811 int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs); 820 int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
812 821
813 u16 qtype = pkt [offs++] << 8; qtype |= pkt [offs++]; 822 u16 qtype = pkt [offs++] << 8; qtype |= pkt [offs++];
814 u16 qclass = pkt [offs++] << 8; qclass |= pkt [offs++]; 823 u16 qclass = pkt [offs++] << 8; qclass |= pkt [offs++];
815 824
… …
822 831
823 int dlen = strlen (THISNODE->domain); 832 int dlen = strlen (THISNODE->domain);
824 833
825 if (qclass == RR_CLASS_IN 834 if (qclass == RR_CLASS_IN
826 && qlen > dlen + 1 835 && qlen > dlen + 1
827 && !memcmp (qname + qlen - dlen - 1, THISNODE->domain, dlen)) 836 && !memcmp (qname + qlen - (dlen + 1), THISNODE->domain, dlen))
828 { 837 {
829 // now generate reply 838 // now generate reply
830 pkt.ancount = htons (1); // one answer RR 839 pkt.ancount = htons (1); // one answer RR
831 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_OK); 840 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_OK);
832 841
… …
884 pkt [offs++] = 0; pkt [offs++] = 0; 893 pkt [offs++] = 0; pkt [offs++] = 0;
885 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
886 895
887 int rdlen_offs = offs += 2; 896 int rdlen_offs = offs += 2;
888 897
889 int dlen = (dns ? ntohs (dns->cfg.max_size) : MAX_PKT_SIZE) - offs;
890 // bind doesn't compress well, so reduce further by one label length
891 dlen -= qlen;
892
893 if (dns) 898 if (dns)
894 { 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
895 // only put data into in-order sequence packets, if 905 // only put data into in-order sequence packets, if
896 // we receive out-of-order packets we generate empty 906 // we receive out-of-order packets we generate empty
897 // replies 907 // replies
898 while (dlen > 1 && !dns->snddq.empty () && in_seq) 908 while (dlen > 1 && !dns->snddq.empty () && in_seq)
899 { 909 {
… …
954 pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class 964 pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
955 pkt [offs++] = 0; pkt [offs++] = 0; 965 pkt [offs++] = 0; pkt [offs++] = 0;
956 pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL 966 pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL
957 pkt [offs++] = 0; pkt [offs++] = 4; // rdlength 967 pkt [offs++] = 0; pkt [offs++] = 4; // rdlength
958 968
959 slog (L_INFO, _("DNS: client %d tries to connect"), client); 969 slog (L_INFO, _("DNS: client %d connects"), client);
960 970
961 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3; 971 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
962 pkt [offs++] = CMD_IP_REJ; 972 pkt [offs++] = CMD_IP_REJ;
963 973
964 if (0 < client && client <= conns.size ()) 974 if (0 < client && client <= conns.size ())
… …
1007 if (dns->send_interval > MAX_SEND_INTERVAL) 1017 if (dns->send_interval > MAX_SEND_INTERVAL)
1008 dns->send_interval = MAX_SEND_INTERVAL; 1018 dns->send_interval = MAX_SEND_INTERVAL;
1009 } 1019 }
1010 else 1020 else
1011 { 1021 {
1012#if 1 1022#if 0
1013 dns->send_interval *= 0.999; 1023 dns->send_interval *= 0.999;
1014#endif 1024#endif
1015 if (dns->send_interval < MIN_SEND_INTERVAL)
1016 dns->send_interval = MIN_SEND_INTERVAL;
1017
1018 // the latency surely puts an upper bound on 1025 // the latency surely puts an upper bound on
1019 // the minimum send interval 1026 // the minimum send interval
1020 double latency = NOW - (*i)->sent; 1027 double latency = NOW - (*i)->sent;
1028
1029 if (latency < dns->min_latency)
1021 dns->last_latency = latency; 1030 dns->min_latency = latency;
1022 1031
1023 if (dns->send_interval > latency) 1032 if (dns->send_interval > dns->min_latency * LATENCY_FACTOR)
1024 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;
1025 } 1037 }
1026 1038
1027 delete *i; 1039 delete *i;
1028 dns_sndpq.erase (i); 1040 dns_sndpq.erase (i);
1029 1041
… …
1146 1158
1147 pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len); 1159 pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len);
1148 1160
1149 if (pkt->len > 0) 1161 if (pkt->len > 0)
1150 { 1162 {
1151 if (THISNODE->dns_port) 1163 if (ntohs (pkt->flags) & FLAG_RESPONSE)
1164 dnsv4_client (*pkt);
1165 else
1152 { 1166 {
1153 dnsv4_server (*pkt); 1167 dnsv4_server (*pkt);
1154 sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len); 1168 sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len);
1155 } 1169 }
1156 else
1157 dnsv4_client (*pkt);
1158 1170
1159 delete pkt; 1171 delete pkt;
1160 } 1172 }
1161 } 1173 }
1162} 1174}
… …
1211 if (!send) 1223 if (!send)
1212 { 1224 {
1213 send = r; 1225 send = r;
1214 1226
1215 r->retry++; 1227 r->retry++;
1216 r->timeout = NOW + (r->retry * last_latency * 8.); 1228 r->timeout = NOW + (r->retry * min_latency * 8.);
1217 1229
1218 // the following code changes the query section a bit, forcing 1230 // the following code changes the query section a bit, forcing
1219 // the forwarder to generate a new request 1231 // the forwarder to generate a new request
1220 if (r->stdhdr) 1232 if (r->stdhdr)
1221 { 1233 {
1222 //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);
1223 //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);
1224 } 1236 }
1225 } 1237 }
1226 } 1238 }
1227 else 1239 else
1228 NEXT (r->timeout); 1240 NEXT (r->timeout);
1229 } 1241 }
1230 1242
1231 if (last_sent + send_interval <= NOW) 1243 if (send || (last_sent + send_interval <= NOW))
1232 { 1244 {
1233 if (!send) 1245 if (!send)
1234 { 1246 {
1235 // generate a new packet, if wise 1247 // generate a new packet, if wise
1236 1248
… …
1246 } 1258 }
1247 else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING 1259 else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING
1248 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) 1260 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
1249 { 1261 {
1250 //printf ("sending data request etc.\n"); //D 1262 //printf ("sending data request etc.\n"); //D
1251 if (!snddq.empty ()) 1263 if (!snddq.empty () || last_received + 1. > NOW)
1252 { 1264 {
1253 poll_interval = send_interval; 1265 poll_interval = send_interval;
1254 NEXT (NOW + send_interval); 1266 NEXT (NOW + send_interval);
1255 } 1267 }
1256 1268
1257 send = new dns_snd (this); 1269 send = new dns_snd (this);
1258 send->gen_stream_req (sndseq, snddq); 1270 send->gen_stream_req (sndseq, snddq);
1259 send->timeout = NOW + last_latency * 8.; 1271 send->timeout = NOW + min_latency * 8.;
1260 1272
1261 sndseq = (sndseq + 1) & SEQNO_MASK; 1273 sndseq = (sndseq + 1) & SEQNO_MASK;
1262 } 1274 }
1263 1275
1264 if (send) 1276 if (send && !send->retry)
1265 vpn->dns_sndpq.push_back (send); 1277 vpn->dns_sndpq.push_back (send);
1266 } 1278 }
1267 1279
1268 if (send) 1280 if (send)
1269 { 1281 {
… …
1274 } 1286 }
1275 } 1287 }
1276 else 1288 else
1277 NEXT (last_sent + send_interval); 1289 NEXT (last_sent + send_interval);
1278 1290
1279 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)",
1280 poll_interval, send_interval, next - NOW, 1292 poll_interval, send_interval, next - NOW,
1281 vpn->dns_sndpq.size (), snddq.size ()); 1293 vpn->dns_sndpq.size (), snddq.size (),
1294 rcvpq.size ());
1282 1295
1283 // 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
1284 if (next < NOW + 0.0001) 1297 if (next < NOW + 0.0001)
1285 next = NOW + 0.1; 1298 next = NOW + 0.1;
1286 1299

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