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/cvs/gvpe/src/vpn_dns.C
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Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.30 by pcg, Mon Mar 14 17:40:01 2005 UTC vs.
Revision 1.31 by pcg, Tue Mar 15 11:43:38 2005 UTC

… …
47#include "vpn.h" 47#include "vpn.h"
48 48
49#define MAX_POLL_INTERVAL 5. // 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
50#define ACTIVITY_INTERVAL 5. 50#define ACTIVITY_INTERVAL 5.
51 51
52#define TIMEOUT_FACTOR 2.
53
52#define INITIAL_TIMEOUT 0.1 // retry timeouts 54#define INITIAL_TIMEOUT 0.1 // retry timeouts
53#define INITIAL_SYN_TIMEOUT 10. // retry timeout for initial syn 55#define INITIAL_SYN_TIMEOUT 10. // retry timeout for initial syn
54 56
55#define MIN_SEND_INTERVAL 0.001 // wait at least this time between sending requests 57#define MIN_SEND_INTERVAL 0.001 // wait at least this time between sending requests
56#define MAX_SEND_INTERVAL 2. // optimistic? 58#define MAX_SEND_INTERVAL 2. // optimistic?
57 59
58#define LATENCY_FACTOR 0.5 // RTT * LATENCY_FACTOR == sending rate 60#define LATENCY_FACTOR 0.5 // RTT * LATENCY_FACTOR == sending rate
59#define MAX_OUTSTANDING 2 // 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 240 // 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 two request bytes less give room for one reply byte
66 68
67#define SEQNO_MASK 0x3fff 69#define SEQNO_MASK 0x0fff
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
71#define MAX_PKT_SIZE 512 73#define MAX_PKT_SIZE 512
72 74
… …
553 double min_latency; 555 double min_latency;
554 double poll_interval, send_interval; 556 double poll_interval, send_interval;
555 557
556 vector<dns_rcv *> rcvpq; 558 vector<dns_rcv *> rcvpq;
557 559
558 byte_stream rcvdq; int rcvseq; 560 byte_stream rcvdq; int rcvseq; int repseq;
559 byte_stream snddq; int sndseq; 561 byte_stream snddq; int sndseq;
560 562
561 void time_cb (time_watcher &w); time_watcher tw; 563 void time_cb (time_watcher &w); time_watcher tw;
562 void receive_rep (dns_rcv *r); 564 void receive_rep (dns_rcv *r);
563 565
… …
720///////////////////////////////////////////////////////////////////////////// 722/////////////////////////////////////////////////////////////////////////////
721 723
722dns_connection::dns_connection (connection *c) 724dns_connection::dns_connection (connection *c)
723: c (c) 725: c (c)
724, rcvdq (MAX_BACKLOG * 2) 726, rcvdq (MAX_BACKLOG * 2)
725, snddq (MAX_BACKLOG * 2) 727, snddq (MAX_BACKLOG)
726, tw (this, &dns_connection::time_cb) 728, tw (this, &dns_connection::time_cb)
727{ 729{
728 vpn = c->vpn; 730 vpn = c->vpn;
729 731
730 established = false; 732 established = false;
731 733
732 rcvseq = sndseq = 0; 734 rcvseq = repseq = sndseq = 0;
733 735
734 last_sent = last_received = 0; 736 last_sent = last_received = 0;
735 poll_interval = 0.5; // starting here 737 poll_interval = 0.5; // starting here
736 send_interval = 0.5; // starting rate 738 send_interval = 0.5; // starting rate
737 min_latency = INITIAL_TIMEOUT; 739 min_latency = INITIAL_TIMEOUT;
… …
855 if (0 < client && client <= conns.size ()) 857 if (0 < client && client <= conns.size ())
856 { 858 {
857 connection *c = conns [client - 1]; 859 connection *c = conns [client - 1];
858 dns_connection *dns = c->dns; 860 dns_connection *dns = c->dns;
859 dns_rcv *rcv; 861 dns_rcv *rcv;
860 bool in_seq;
861 862
862 if (dns) 863 if (dns)
863 { 864 {
864 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 (); )
865 if (SEQNO_EQ ((*i)->seqno, seqno)) 866 if (SEQNO_EQ ((*i)->seqno, seqno))
… …
876 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);
877 878
878 goto duplicate_request; 879 goto duplicate_request;
879 } 880 }
880 881
881 in_seq = dns->rcvseq == seqno;
882
883 // new packet, queue 882 // new packet, queue
884 rcv = new dns_rcv (seqno, data, datalen); 883 rcv = new dns_rcv (seqno, data, datalen);
885 dns->receive_rep (rcv); 884 dns->receive_rep (rcv);
886 } 885 }
887 886
… …
904 dlen -= qlen; 903 dlen -= qlen;
905 904
906 // only put data into in-order sequence packets, if 905 // only put data into in-order sequence packets, if
907 // we receive out-of-order packets we generate empty 906 // we receive out-of-order packets we generate empty
908 // replies 907 // replies
909 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)
910 { 910 {
911 dns->repseq = seqno;
912
913 while (dlen > 1 && !dns->snddq.empty ())
914 {
911 int txtlen = dlen <= 255 ? dlen - 1 : 255; 915 int txtlen = dlen <= 255 ? dlen - 1 : 255;
912 916
913 if (txtlen > dns->snddq.size ()) 917 if (txtlen > dns->snddq.size ())
914 txtlen = dns->snddq.size (); 918 txtlen = dns->snddq.size ();
915 919
916 pkt[offs++] = txtlen; 920 pkt[offs++] = txtlen;
917 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen); 921 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
918 offs += txtlen; 922 offs += txtlen;
919 dns->snddq.remove (txtlen); 923 dns->snddq.remove (txtlen);
920 924
921 dlen -= txtlen + 1; 925 dlen -= txtlen + 1;
926 }
922 } 927 }
923 928
924 // avoid empty TXT rdata 929 // avoid completely empty TXT rdata
925 if (offs == rdlen_offs) 930 if (offs == rdlen_offs)
926 pkt[offs++] = 0; 931 pkt[offs++] = 0;
927 932
928 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ()); 933 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
929 } 934 }
… …
1184 connection *c = conns [client - 1]; 1189 connection *c = conns [client - 1];
1185 1190
1186 if (!c->dns) 1191 if (!c->dns)
1187 c->dns = new dns_connection (c); 1192 c->dns = new dns_connection (c);
1188 1193
1189 if (!c->dns->snddq.put (pkt)) 1194 if (c->dns->snddq.put (pkt))
1190 return false;
1191
1192 c->dns->tw.trigger (); 1195 c->dns->tw.trigger ();
1193 1196
1197 // always return true even if the buffer overflows
1194 return true; 1198 return true;
1195} 1199}
1196 1200
1197void 1201void
1198connection::dnsv4_reset_connection () 1202connection::dnsv4_reset_connection ()
… …
1224 if (!send) 1228 if (!send)
1225 { 1229 {
1226 send = r; 1230 send = r;
1227 1231
1228 r->retry++; 1232 r->retry++;
1229 r->timeout = NOW + (r->retry * min_latency * 8.); 1233 r->timeout = NOW + (r->retry * min_latency * TIMEOUT_FACTOR);
1230 1234
1231 // the following code changes the query section a bit, forcing 1235 // the following code changes the query section a bit, forcing
1232 // the forwarder to generate a new request 1236 // the forwarder to generate a new request
1233 if (r->stdhdr) 1237 if (r->stdhdr)
1234 { 1238 {
… …
1267 NEXT (NOW + send_interval); 1271 NEXT (NOW + send_interval);
1268 } 1272 }
1269 1273
1270 send = new dns_snd (this); 1274 send = new dns_snd (this);
1271 send->gen_stream_req (sndseq, snddq); 1275 send->gen_stream_req (sndseq, snddq);
1272 send->timeout = NOW + min_latency * 8.; 1276 send->timeout = NOW + min_latency * TIMEOUT_FACTOR;
1273 1277
1274 sndseq = (sndseq + 1) & SEQNO_MASK; 1278 sndseq = (sndseq + 1) & SEQNO_MASK;
1275 } 1279 }
1276 else 1280 else
1277 NEXT (last_sent + send_interval); 1281 NEXT (last_sent + send_interval);
… …
1282 } 1286 }
1283 1287
1284 if (send) 1288 if (send)
1285 { 1289 {
1286 last_sent = NOW; 1290 last_sent = NOW;
1291 if (rand () & 15 != 0)//D
1287 sendto (vpn->dnsv4_fd, 1292 sendto (vpn->dnsv4_fd,
1288 send->pkt->at (0), send->pkt->len, 0, 1293 send->pkt->at (0), send->pkt->len, 0,
1289 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); 1294 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
1290 } 1295 }
1291 1296

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