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Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.21 by pcg, Sun Mar 6 21:33:40 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
58#define LATENCY_FACTOR 0.5 // RTT * LATENCY_FACTOR == sending rate
59#define MAX_OUTSTANDING 10 // max. outstanding requests 59#define MAX_OUTSTANDING 2 // max. outstanding requests
60#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog 60#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 61#define MAX_BACKLOG (100*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE
62 62
63#define MAX_DOMAIN_SIZE 220 // 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
64// 240 leaves about 4 bytes of server reply data 64// 240 leaves about 4 bytes of server reply data
65// every two request bytes less give room for one reply byte 65// every two request bytes less give room for one reply byte
66 66
67#define SEQNO_MASK 0x3fff 67#define SEQNO_MASK 0x3fff
68#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) ) 68#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )
… …
265static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO"); 265static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO");
266 266
267///////////////////////////////////////////////////////////////////////////// 267/////////////////////////////////////////////////////////////////////////////
268 268
269#define HDRSIZE 6 269#define HDRSIZE 6
270 270
271inline void encode_header (char *data, int clientid, int seqno, int retry = 0) 271inline void encode_header (char *data, int clientid, int seqno, int retry = 0)
272{ 272{
273 seqno &= SEQNO_MASK; 273 seqno &= SEQNO_MASK;
274 274
275 u8 hdr[3] = { 275 u8 hdr[3] = {
… …
409struct dns_cfg 409struct dns_cfg
410{ 410{
411 static int next_uid; 411 static int next_uid;
412 412
413 u8 id1, id2, id3, id4; 413 u8 id1, id2, id3, id4;
414
414 u8 version; 415 u8 version;
416 u8 flags;
415 u8 rrtype; 417 u8 rrtype;
416 u8 flags;
417 u8 def_ttl; 418 u8 def_ttl;
418 u8 rcv_cdc; 419
419 u8 snd_cdc;
420 u16 max_size;
421 u16 client; 420 u16 client;
422 u16 uid; // to make request unique 421 u16 uid; // to make request unique
423 422
424 u8 reserved[8]; 423 u16 max_size;
424 u8 seq_cdc;
425 u8 req_cdc;
426
427 u8 rep_cdc;
428 u8 delay; // time in 0.01s units that the server may delay replying packets
429 u8 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++;
457 delay = 0;
449 458
450 memset (reserved, 0, 8); 459 r3 = r4 = 0;
460 r4 = r5 = r6 = r7 = 0;
451} 461}
452 462
453bool dns_cfg::valid () 463bool dns_cfg::valid ()
454{ 464{
455 return id1 == 'G' 465 return id1 == 'G'
456 && id2 == 'V' 466 && id2 == 'V'
457 && id3 == 'P' 467 && id3 == 'P'
458 && id4 == 'E' 468 && id4 == 'E'
469 && seq_cdc == 26
470 && req_cdc == 62
471 && rep_cdc == 0
459 && version == 1 472 && version == 1;
460 && flags == 0
461 && rcv_cdc == 0
462 && snd_cdc == 62
463 && max_size == ntohs (MAX_PKT_SIZE);
464} 473}
465 474
466struct dns_packet : net_packet 475struct dns_packet : net_packet
467{ 476{
468 u16 id; 477 u16 id;
469 u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4 478 u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4
470 u16 qdcount, ancount, nscount, arcount; 479 u16 qdcount, ancount, nscount, arcount;
471 480
472 u8 data[MAXSIZE - 6 * 2]; 481 u8 data [MAXSIZE - 6 * 2];
473 482
474 int decode_label (char *data, int size, int &offs); 483 int decode_label (char *data, int size, int &offs);
475}; 484};
476 485
477int dns_packet::decode_label (char *data, int size, int &offs) 486int dns_packet::decode_label (char *data, int size, int &offs)
… …
539 548
540 bool established; 549 bool established;
541 550
542 tstamp last_received; 551 tstamp last_received;
543 tstamp last_sent; 552 tstamp last_sent;
544 double last_latency; 553 double min_latency;
545 double poll_interval, send_interval; 554 double poll_interval, send_interval;
546 555
547 vector<dns_rcv *> rcvpq; 556 vector<dns_rcv *> rcvpq;
548 557
549 byte_stream rcvdq; int rcvseq; 558 byte_stream rcvdq; int rcvseq;
… …
663} 672}
664 673
665void dns_snd::gen_syn_req () 674void dns_snd::gen_syn_req ()
666{ 675{
667 timeout = NOW + INITIAL_SYN_TIMEOUT; 676 timeout = NOW + INITIAL_SYN_TIMEOUT;
668
669 printf ("send syn\n");//D
670 677
671 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 678 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
672 pkt->qdcount = htons (1); 679 pkt->qdcount = htons (1);
673 680
674 int offs = 6 * 2; 681 int offs = 6 * 2;
… …
723 established = false; 730 established = false;
724 731
725 rcvseq = sndseq = 0; 732 rcvseq = sndseq = 0;
726 733
727 last_sent = last_received = 0; 734 last_sent = last_received = 0;
728 poll_interval = MIN_POLL_INTERVAL; 735 poll_interval = 0.5; // starting here
729 send_interval = 0.5; // starting rate 736 send_interval = 0.5; // starting rate
730 last_latency = INITIAL_TIMEOUT; 737 min_latency = INITIAL_TIMEOUT;
731} 738}
732 739
733dns_connection::~dns_connection () 740dns_connection::~dns_connection ()
734{ 741{
735 for (vector<dns_rcv *>::iterator i = rcvpq.begin (); 742 for (vector<dns_rcv *>::iterator i = rcvpq.begin ();
… …
748 poll_interval = send_interval; 755 poll_interval = send_interval;
749 } 756 }
750 else 757 else
751 { 758 {
752 poll_interval *= 1.5; 759 poll_interval *= 1.5;
760
753 if (poll_interval > MAX_POLL_INTERVAL) 761 if (poll_interval > MAX_POLL_INTERVAL)
754 poll_interval = MAX_POLL_INTERVAL; 762 poll_interval = MAX_POLL_INTERVAL;
755 } 763 }
756 764
757 rcvpq.push_back (r); 765 rcvpq.push_back (r);
… …
807 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR); 815 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR);
808 816
809 if (0 == (flags & (FLAG_RESPONSE | FLAG_OP_MASK)) 817 if (0 == (flags & (FLAG_RESPONSE | FLAG_OP_MASK))
810 && pkt.qdcount == htons (1)) 818 && pkt.qdcount == htons (1))
811 { 819 {
812 char qname[MAXSIZE]; 820 char qname [MAXSIZE];
813 int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs); 821 int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
814 822
815 u16 qtype = pkt [offs++] << 8; qtype |= pkt [offs++]; 823 u16 qtype = pkt [offs++] << 8; qtype |= pkt [offs++];
816 u16 qclass = pkt [offs++] << 8; qclass |= pkt [offs++]; 824 u16 qclass = pkt [offs++] << 8; qclass |= pkt [offs++];
817 825
… …
824 832
825 int dlen = strlen (THISNODE->domain); 833 int dlen = strlen (THISNODE->domain);
826 834
827 if (qclass == RR_CLASS_IN 835 if (qclass == RR_CLASS_IN
828 && qlen > dlen + 1 836 && qlen > dlen + 1
829 && !memcmp (qname + qlen - dlen - 1, THISNODE->domain, dlen)) 837 && !memcmp (qname + qlen - (dlen + 1), THISNODE->domain, dlen))
830 { 838 {
831 // now generate reply 839 // now generate reply
832 pkt.ancount = htons (1); // one answer RR 840 pkt.ancount = htons (1); // one answer RR
833 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_OK); 841 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_OK);
834 842
… …
886 pkt [offs++] = 0; pkt [offs++] = 0; 894 pkt [offs++] = 0; pkt [offs++] = 0;
887 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
888 896
889 int rdlen_offs = offs += 2; 897 int rdlen_offs = offs += 2;
890 898
891 int dlen = (dns ? ntohs (dns->cfg.max_size) : MAX_PKT_SIZE) - offs;
892 // bind doesn't compress well, so reduce further by one label length
893 dlen -= qlen;
894
895 if (dns) 899 if (dns)
896 { 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
897 // only put data into in-order sequence packets, if 906 // only put data into in-order sequence packets, if
898 // we receive out-of-order packets we generate empty 907 // we receive out-of-order packets we generate empty
899 // replies 908 // replies
900 while (dlen > 1 && !dns->snddq.empty () && in_seq) 909 while (dlen > 1 && !dns->snddq.empty () && in_seq)
901 { 910 {
… …
956 pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class 965 pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
957 pkt [offs++] = 0; pkt [offs++] = 0; 966 pkt [offs++] = 0; pkt [offs++] = 0;
958 pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL 967 pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL
959 pkt [offs++] = 0; pkt [offs++] = 4; // rdlength 968 pkt [offs++] = 0; pkt [offs++] = 4; // rdlength
960 969
961 slog (L_INFO, _("DNS: client %d tries to connect"), client); 970 slog (L_INFO, _("DNS: client %d connects"), client);
962 971
963 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3; 972 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
964 pkt [offs++] = CMD_IP_REJ; 973 pkt [offs++] = CMD_IP_REJ;
965 974
966 if (0 < client && client <= conns.size ()) 975 if (0 < client && client <= conns.size ())
… …
1009 if (dns->send_interval > MAX_SEND_INTERVAL) 1018 if (dns->send_interval > MAX_SEND_INTERVAL)
1010 dns->send_interval = MAX_SEND_INTERVAL; 1019 dns->send_interval = MAX_SEND_INTERVAL;
1011 } 1020 }
1012 else 1021 else
1013 { 1022 {
1014#if 1 1023#if 0
1015 dns->send_interval *= 0.999; 1024 dns->send_interval *= 0.999;
1016#endif 1025#endif
1017 if (dns->send_interval < MIN_SEND_INTERVAL)
1018 dns->send_interval = MIN_SEND_INTERVAL;
1019
1020 // the latency surely puts an upper bound on 1026 // the latency surely puts an upper bound on
1021 // the minimum send interval 1027 // the minimum send interval
1022 double latency = NOW - (*i)->sent; 1028 double latency = NOW - (*i)->sent;
1029
1030 if (latency < dns->min_latency)
1023 dns->last_latency = latency; 1031 dns->min_latency = latency;
1024 1032
1025 if (dns->send_interval > latency) 1033 if (dns->send_interval > dns->min_latency * LATENCY_FACTOR)
1026 dns->send_interval = latency; 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;
1027 } 1038 }
1028 1039
1029 delete *i; 1040 delete *i;
1030 dns_sndpq.erase (i); 1041 dns_sndpq.erase (i);
1031 1042
… …
1148 1159
1149 pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len); 1160 pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len);
1150 1161
1151 if (pkt->len > 0) 1162 if (pkt->len > 0)
1152 { 1163 {
1153 if (THISNODE->dns_port) 1164 if (ntohs (pkt->flags) & FLAG_RESPONSE)
1165 dnsv4_client (*pkt);
1166 else
1154 { 1167 {
1155 dnsv4_server (*pkt); 1168 dnsv4_server (*pkt);
1156 sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len); 1169 sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len);
1157 } 1170 }
1158 else
1159 dnsv4_client (*pkt);
1160 1171
1161 delete pkt; 1172 delete pkt;
1162 } 1173 }
1163 } 1174 }
1164} 1175}
… …
1213 if (!send) 1224 if (!send)
1214 { 1225 {
1215 send = r; 1226 send = r;
1216 1227
1217 r->retry++; 1228 r->retry++;
1218 r->timeout = NOW + (r->retry * last_latency * 8.); 1229 r->timeout = NOW + (r->retry * min_latency * 8.);
1219 1230
1220 // the following code changes the query section a bit, forcing 1231 // the following code changes the query section a bit, forcing
1221 // the forwarder to generate a new request 1232 // the forwarder to generate a new request
1222 if (r->stdhdr) 1233 if (r->stdhdr)
1223 { 1234 {
1224 //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);
1225 //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);
1226 } 1237 }
1227 } 1238 }
1228 } 1239 }
1229 else 1240 else
1230 NEXT (r->timeout); 1241 NEXT (r->timeout);
1231 } 1242 }
1232 1243
1233 if (last_sent + send_interval <= NOW)
1234 {
1235 if (!send) 1244 if (!send)
1245 {
1246 // generate a new packet, if wise
1247
1248 if (!established)
1236 { 1249 {
1237 // generate a new packet, if wise 1250 if (vpn->dns_sndpq.empty ())
1238
1239 if (!established)
1240 { 1251 {
1241 if (vpn->dns_sndpq.empty ())
1242 {
1243 send = new dns_snd (this); 1252 send = new dns_snd (this);
1244 1253
1245 printf ("new conn %p %d\n", this, c->conf->id);//D
1246 cfg.reset (THISNODE->id); 1254 cfg.reset (THISNODE->id);
1247 send->gen_syn_req (); 1255 send->gen_syn_req ();
1248 }
1249 } 1256 }
1257 }
1250 else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING 1258 else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING
1251 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) 1259 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
1260 {
1261 if (last_sent + send_interval <= NOW)
1252 { 1262 {
1253 //printf ("sending data request etc.\n"); //D 1263 //printf ("sending data request etc.\n"); //D
1254 if (!snddq.empty ()) 1264 if (!snddq.empty () || last_received + 1. > NOW)
1255 { 1265 {
1256 poll_interval = send_interval; 1266 poll_interval = send_interval;
1257 NEXT (NOW + send_interval); 1267 NEXT (NOW + send_interval);
1258 } 1268 }
1259 1269
1260 send = new dns_snd (this); 1270 send = new dns_snd (this);
1261 send->gen_stream_req (sndseq, snddq); 1271 send->gen_stream_req (sndseq, snddq);
1262 send->timeout = NOW + last_latency * 8.; 1272 send->timeout = NOW + min_latency * 8.;
1263 1273
1264 sndseq = (sndseq + 1) & SEQNO_MASK; 1274 sndseq = (sndseq + 1) & SEQNO_MASK;
1265 } 1275 }
1266 1276 else
1267 if (send) 1277 NEXT (last_sent + send_interval);
1268 vpn->dns_sndpq.push_back (send);
1269 } 1278 }
1270 1279
1271 if (send) 1280 if (send)
1272 { 1281 vpn->dns_sndpq.push_back (send);
1282 }
1283
1284 if (send)
1285 {
1273 last_sent = NOW; 1286 last_sent = NOW;
1274 sendto (vpn->dnsv4_fd, 1287 sendto (vpn->dnsv4_fd,
1275 send->pkt->at (0), send->pkt->len, 0, 1288 send->pkt->at (0), send->pkt->len, 0,
1276 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); 1289 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
1277 }
1278 } 1290 }
1279 else
1280 NEXT (last_sent + send_interval);
1281 1291
1282 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)",
1283 poll_interval, send_interval, next - NOW, 1293 poll_interval, send_interval, next - NOW,
1284 vpn->dns_sndpq.size (), snddq.size ()); 1294 vpn->dns_sndpq.size (), snddq.size (),
1295 rcvpq.size ());
1285 1296
1286 // 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
1287 if (next < NOW + 0.0001) 1298 if (next < NOW + 0.001)
1288 next = NOW + 0.1; 1299 next = NOW + 0.1;
1289 1300
1290 w.start (next); 1301 w.start (next);
1291} 1302}
1292 1303

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