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/cvs/gvpe/src/vpn_dns.C
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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 1.25 by pcg, Mon Mar 7 22:24:24 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) )
… …
547 548
548 bool established; 549 bool established;
549 550
550 tstamp last_received; 551 tstamp last_received;
551 tstamp last_sent; 552 tstamp last_sent;
552 double last_latency; 553 double min_latency;
553 double poll_interval, send_interval; 554 double poll_interval, send_interval;
554 555
555 vector<dns_rcv *> rcvpq; 556 vector<dns_rcv *> rcvpq;
556 557
557 byte_stream rcvdq; int rcvseq; 558 byte_stream rcvdq; int rcvseq;
… …
731 rcvseq = sndseq = 0; 732 rcvseq = sndseq = 0;
732 733
733 last_sent = last_received = 0; 734 last_sent = last_received = 0;
734 poll_interval = MIN_POLL_INTERVAL; 735 poll_interval = MIN_POLL_INTERVAL;
735 send_interval = 0.5; // starting rate 736 send_interval = 0.5; // starting rate
736 last_latency = INITIAL_TIMEOUT; 737 min_latency = INITIAL_TIMEOUT;
737} 738}
738 739
739dns_connection::~dns_connection () 740dns_connection::~dns_connection ()
740{ 741{
741 for (vector<dns_rcv *>::iterator i = rcvpq.begin (); 742 for (vector<dns_rcv *>::iterator i = rcvpq.begin ();
… …
754 poll_interval = send_interval; 755 poll_interval = send_interval;
755 } 756 }
756 else 757 else
757 { 758 {
758 poll_interval *= 1.5; 759 poll_interval *= 1.5;
760
759 if (poll_interval > MAX_POLL_INTERVAL) 761 if (poll_interval > MAX_POLL_INTERVAL)
760 poll_interval = MAX_POLL_INTERVAL; 762 poll_interval = MAX_POLL_INTERVAL;
761 } 763 }
762 764
763 rcvpq.push_back (r); 765 rcvpq.push_back (r);
… …
1024 dns->send_interval = MIN_SEND_INTERVAL; 1026 dns->send_interval = MIN_SEND_INTERVAL;
1025 1027
1026 // the latency surely puts an upper bound on 1028 // the latency surely puts an upper bound on
1027 // the minimum send interval 1029 // the minimum send interval
1028 double latency = NOW - (*i)->sent; 1030 double latency = NOW - (*i)->sent;
1031
1032 if (latency < dns->min_latency)
1029 dns->last_latency = latency; 1033 dns->min_latency = latency;
1030 1034
1031 if (dns->send_interval > latency) 1035 if (dns->send_interval > dns->min_latency * LATENCY_FACTOR)
1032 dns->send_interval = latency; 1036 dns->send_interval = dns->min_latency * LATENCY_FACTOR;
1033 } 1037 }
1034 1038
1035 delete *i; 1039 delete *i;
1036 dns_sndpq.erase (i); 1040 dns_sndpq.erase (i);
1037 1041
… …
1219 if (!send) 1223 if (!send)
1220 { 1224 {
1221 send = r; 1225 send = r;
1222 1226
1223 r->retry++; 1227 r->retry++;
1224 r->timeout = NOW + (r->retry * last_latency * 8.); 1228 r->timeout = NOW + (r->retry * min_latency * 8.);
1225 1229
1226 // the following code changes the query section a bit, forcing 1230 // the following code changes the query section a bit, forcing
1227 // the forwarder to generate a new request 1231 // the forwarder to generate a new request
1228 if (r->stdhdr) 1232 if (r->stdhdr)
1229 { 1233 {
… …
1254 } 1258 }
1255 else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING 1259 else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING
1256 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) 1260 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
1257 { 1261 {
1258 //printf ("sending data request etc.\n"); //D 1262 //printf ("sending data request etc.\n"); //D
1259 if (!snddq.empty ()) 1263 if (!snddq.empty () || last_received + 1. > NOW)
1260 { 1264 {
1261 poll_interval = send_interval; 1265 poll_interval = send_interval;
1262 NEXT (NOW + send_interval); 1266 NEXT (NOW + send_interval);
1263 } 1267 }
1264 1268
1265 send = new dns_snd (this); 1269 send = new dns_snd (this);
1266 send->gen_stream_req (sndseq, snddq); 1270 send->gen_stream_req (sndseq, snddq);
1267 send->timeout = NOW + last_latency * 8.; 1271 send->timeout = NOW + min_latency * 8.;
1268 1272
1269 sndseq = (sndseq + 1) & SEQNO_MASK; 1273 sndseq = (sndseq + 1) & SEQNO_MASK;
1270 } 1274 }
1271 1275
1272 if (send) 1276 if (send)

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