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Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.20 by pcg, Sun Mar 6 21:32:15 2005 UTC vs.
Revision 1.26 by pcg, Tue Mar 8 17:25:27 2005 UTC

… …
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 0.5 // 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 20 // 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 = ntohs (MAX_PKT_SIZE);
447 client = ntohs (clientid); 455 client = ntohs (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); 472 && 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;
… …
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 = MIN_POLL_INTERVAL;
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
… …
875 // new packet, queue 883 // new packet, queue
876 rcv = new dns_rcv (seqno, data, datalen); 884 rcv = new dns_rcv (seqno, data, datalen);
877 dns->receive_rep (rcv); 885 dns->receive_rep (rcv);
878 } 886 }
879 887
888 {
880 pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section 889 pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section
881 890
882 int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A; 891 int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A;
883 pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type 892 pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type
884 pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class 893 pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
885 pkt [offs++] = 0; pkt [offs++] = 0; 894 pkt [offs++] = 0; pkt [offs++] = 0;
886 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
887 896
888 int rdlen_offs = offs += 2; 897 int rdlen_offs = offs += 2;
889 898
890 int dlen = (dns ? ntohs (dns->cfg.max_size) : MAX_PKT_SIZE) - offs; 899 int dlen = (dns ? ntohs (dns->cfg.max_size) : MAX_PKT_SIZE) - offs;
891 // bind doesn't compress well, so reduce further by one label length 900 // bind doesn't compress well, so reduce further by one label length
892 dlen -= qlen; 901 dlen -= qlen;
893 902
894 if (dns) 903 if (dns)
895 { 904 {
896 // only put data into in-order sequence packets, if 905 // only put data into in-order sequence packets, if
897 // we receive out-of-order packets we generate empty 906 // we receive out-of-order packets we generate empty
898 // replies 907 // replies
899 while (dlen > 1 && !dns->snddq.empty () && in_seq) 908 while (dlen > 1 && !dns->snddq.empty () && in_seq)
900 { 909 {
901 int txtlen = dlen <= 255 ? dlen - 1 : 255; 910 int txtlen = dlen <= 255 ? dlen - 1 : 255;
902 911
903 if (txtlen > dns->snddq.size ()) 912 if (txtlen > dns->snddq.size ())
904 txtlen = dns->snddq.size (); 913 txtlen = dns->snddq.size ();
905 914
906 pkt[offs++] = txtlen; 915 pkt[offs++] = txtlen;
907 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen); 916 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
908 offs += txtlen; 917 offs += txtlen;
909 dns->snddq.remove (txtlen); 918 dns->snddq.remove (txtlen);
910 919
911 dlen -= txtlen + 1; 920 dlen -= txtlen + 1;
912 } 921 }
913 922
914 // avoid empty TXT rdata 923 // avoid empty TXT rdata
915 if (offs == rdlen_offs) 924 if (offs == rdlen_offs)
916 pkt[offs++] = 0; 925 pkt[offs++] = 0;
917 926
918 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ()); 927 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
919 } 928 }
920 else 929 else
921 { 930 {
922 // send RST 931 // send RST
923 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3; 932 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
924 pkt [offs++] = CMD_IP_RST; 933 pkt [offs++] = CMD_IP_RST;
925 } 934 }
926 935
927 int rdlen = offs - rdlen_offs; 936 int rdlen = offs - rdlen_offs;
928 937
929 pkt [rdlen_offs - 2] = rdlen >> 8; 938 pkt [rdlen_offs - 2] = rdlen >> 8;
930 pkt [rdlen_offs - 1] = rdlen; 939 pkt [rdlen_offs - 1] = rdlen;
931 940
932 if (dns) 941 if (dns)
933 { 942 {
934 // now update dns_rcv copy 943 // now update dns_rcv copy
935 rcv->pkt->len = offs; 944 rcv->pkt->len = offs;
936 memcpy (rcv->pkt->at (0), pkt.at (0), offs); 945 memcpy (rcv->pkt->at (0), pkt.at (0), offs);
937 } 946 }
947 }
938 948
939 duplicate_request: ; 949 duplicate_request: ;
940 } 950 }
941 else 951 else
942 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR); 952 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR);
… …
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) 1025 if (dns->send_interval < MIN_SEND_INTERVAL)
1016 dns->send_interval = MIN_SEND_INTERVAL; 1026 dns->send_interval = MIN_SEND_INTERVAL;
1017 1027
1018 // the latency surely puts an upper bound on 1028 // the latency surely puts an upper bound on
1019 // the minimum send interval 1029 // the minimum send interval
1020 double latency = NOW - (*i)->sent; 1030 double latency = NOW - (*i)->sent;
1031
1032 if (latency < dns->min_latency)
1021 dns->last_latency = latency; 1033 dns->min_latency = latency;
1022 1034
1023 if (dns->send_interval > latency) 1035 if (dns->send_interval > dns->min_latency * LATENCY_FACTOR)
1024 dns->send_interval = latency; 1036 dns->send_interval = dns->min_latency * LATENCY_FACTOR;
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 {
… …
1238 { 1250 {
1239 if (vpn->dns_sndpq.empty ()) 1251 if (vpn->dns_sndpq.empty ())
1240 { 1252 {
1241 send = new dns_snd (this); 1253 send = new dns_snd (this);
1242 1254
1243 printf ("new conn %p %d\n", this, c->conf->id);//D
1244 cfg.reset (THISNODE->id); 1255 cfg.reset (THISNODE->id);
1245 send->gen_syn_req (); 1256 send->gen_syn_req ();
1246 } 1257 }
1247 } 1258 }
1248 else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING 1259 else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING
1249 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) 1260 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
1250 { 1261 {
1251 //printf ("sending data request etc.\n"); //D 1262 //printf ("sending data request etc.\n"); //D
1252 if (!snddq.empty ()) 1263 if (!snddq.empty () || last_received + 1. > NOW)
1253 { 1264 {
1254 poll_interval = send_interval; 1265 poll_interval = send_interval;
1255 NEXT (NOW + send_interval); 1266 NEXT (NOW + send_interval);
1256 } 1267 }
1257 1268
1258 send = new dns_snd (this); 1269 send = new dns_snd (this);
1259 send->gen_stream_req (sndseq, snddq); 1270 send->gen_stream_req (sndseq, snddq);
1260 send->timeout = NOW + last_latency * 8.; 1271 send->timeout = NOW + min_latency * 8.;
1261 1272
1262 sndseq = (sndseq + 1) & SEQNO_MASK; 1273 sndseq = (sndseq + 1) & SEQNO_MASK;
1263 } 1274 }
1264 1275
1265 if (send) 1276 if (send)

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