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/cvs/gvpe/src/vpn_dns.C
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Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.29 by pcg, Sun Mar 13 12:40:20 2005 UTC vs.
Revision 1.37 by pcg, Wed Mar 23 17:03:58 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 2. // retry timeout for initial syn
55 54
56#define MIN_SEND_INTERVAL 0.01 // wait at least this time between sending requests
57#define MAX_SEND_INTERVAL 2. // optimistic? 55#define MAX_SEND_INTERVAL 2. // optimistic?
58 56
59#define LATENCY_FACTOR 0.5 // RTT * LATENCY_FACTOR == sending rate
60#define MAX_OUTSTANDING 100 // max. outstanding requests
61#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog 57#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog
62#define MAX_BACKLOG (100*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE 58#define MAX_BACKLOG (64*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE
63 59
64#define MAX_DOMAIN_SIZE 240 // 255 is legal limit, but bind doesn't compress well 60#define MAX_DOMAIN_SIZE 240 // 255 is legal limit, but bind doesn't compress well
65// 240 leaves about 4 bytes of server reply data 61// 240 leaves about 4 bytes of server reply data
66// every two request bytes less give room for one reply byte 62// every request byte less give room for two reply bytes
67 63
68#define SEQNO_MASK 0x3fff 64#define SEQNO_MASK 0x3fff
69#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) ) 65#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )
70 66
71#define MAX_LBL_SIZE 63 67#define MAX_LBL_SIZE 63
… …
424 u16 max_size; 420 u16 max_size;
425 u8 seq_cdc; 421 u8 seq_cdc;
426 u8 req_cdc; 422 u8 req_cdc;
427 423
428 u8 rep_cdc; 424 u8 rep_cdc;
425 u8 delay; // time in 0.01s units that the server may delay replying packets
429 u8 r2, r3, r4; 426 u8 r3, r4;
430 427
431 u8 r5, r6, r7, r8; 428 u8 r5, r6, r7, r8;
432 429
433 void reset (int clientid); 430 void reset (int clientid);
434 bool valid (); 431 bool valid ();
… …
452 req_cdc = 62; 449 req_cdc = 62;
453 rep_cdc = 0; 450 rep_cdc = 0;
454 max_size = htons (MAX_PKT_SIZE); 451 max_size = htons (MAX_PKT_SIZE);
455 client = htons (clientid); 452 client = htons (clientid);
456 uid = next_uid++; 453 uid = next_uid++;
454 delay = 0;
457 455
458 r2 = r3 = r4 = 0; 456 r3 = r4 = 0;
459 r4 = r5 = r6 = r7 = 0; 457 r4 = r5 = r6 = r7 = 0;
460} 458}
461 459
462bool dns_cfg::valid () 460bool dns_cfg::valid ()
463{ 461{
… …
552 double min_latency; 550 double min_latency;
553 double poll_interval, send_interval; 551 double poll_interval, send_interval;
554 552
555 vector<dns_rcv *> rcvpq; 553 vector<dns_rcv *> rcvpq;
556 554
557 byte_stream rcvdq; int rcvseq; 555 byte_stream rcvdq; int rcvseq; int repseq;
558 byte_stream snddq; int sndseq; 556 byte_stream snddq; int sndseq;
559 557
560 void time_cb (time_watcher &w); time_watcher tw; 558 void time_cb (time_watcher &w); time_watcher tw;
561 void receive_rep (dns_rcv *r); 559 void receive_rep (dns_rcv *r);
562 560
… …
719///////////////////////////////////////////////////////////////////////////// 717/////////////////////////////////////////////////////////////////////////////
720 718
721dns_connection::dns_connection (connection *c) 719dns_connection::dns_connection (connection *c)
722: c (c) 720: c (c)
723, rcvdq (MAX_BACKLOG * 2) 721, rcvdq (MAX_BACKLOG * 2)
724, snddq (MAX_BACKLOG * 2) 722, snddq (MAX_BACKLOG)
725, tw (this, &dns_connection::time_cb) 723, tw (this, &dns_connection::time_cb)
726{ 724{
727 vpn = c->vpn; 725 vpn = c->vpn;
728 726
729 established = false; 727 established = false;
730 728
731 rcvseq = sndseq = 0; 729 rcvseq = repseq = sndseq = 0;
732 730
733 last_sent = last_received = 0; 731 last_sent = last_received = 0;
734 poll_interval = MIN_POLL_INTERVAL; 732 poll_interval = 0.5; // starting here
735 send_interval = 0.5; // starting rate 733 send_interval = 0.5; // starting rate
736 min_latency = INITIAL_TIMEOUT; 734 min_latency = INITIAL_TIMEOUT;
737} 735}
738 736
739dns_connection::~dns_connection () 737dns_connection::~dns_connection ()
… …
790 } 788 }
791 789
792 while (vpn_packet *pkt = rcvdq.get ()) 790 while (vpn_packet *pkt = rcvdq.get ())
793 { 791 {
794 sockinfo si; 792 sockinfo si;
795 si.host = 0x01010101; si.port = htons (c->conf->id); si.prot = PROT_DNSv4; 793 si.host = htonl (c->conf->id); si.port = 0; si.prot = PROT_DNSv4;
796 794
797 vpn->recv_vpn_packet (pkt, si); 795 vpn->recv_vpn_packet (pkt, si);
798 796
799 delete pkt; 797 delete pkt;
800 } 798 }
… …
854 if (0 < client && client <= conns.size ()) 852 if (0 < client && client <= conns.size ())
855 { 853 {
856 connection *c = conns [client - 1]; 854 connection *c = conns [client - 1];
857 dns_connection *dns = c->dns; 855 dns_connection *dns = c->dns;
858 dns_rcv *rcv; 856 dns_rcv *rcv;
859 bool in_seq;
860 857
861 if (dns) 858 if (dns)
862 { 859 {
863 for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); ) 860 for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); )
864 if (SEQNO_EQ ((*i)->seqno, seqno)) 861 if (SEQNO_EQ ((*i)->seqno, seqno))
… …
875 memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len); 872 memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len);
876 873
877 goto duplicate_request; 874 goto duplicate_request;
878 } 875 }
879 876
880 in_seq = dns->rcvseq == seqno;
881
882 // new packet, queue 877 // new packet, queue
883 rcv = new dns_rcv (seqno, data, datalen); 878 rcv = new dns_rcv (seqno, data, datalen);
884 dns->receive_rep (rcv); 879 dns->receive_rep (rcv);
885 } 880 }
886 881
… …
903 dlen -= qlen; 898 dlen -= qlen;
904 899
905 // only put data into in-order sequence packets, if 900 // only put data into in-order sequence packets, if
906 // we receive out-of-order packets we generate empty 901 // we receive out-of-order packets we generate empty
907 // replies 902 // replies
908 while (dlen > 1 && !dns->snddq.empty () && in_seq) 903 //printf ("%d - %d & %x (=%d) < %d\n", seqno, dns->repseq, SEQNO_MASK, (seqno - dns->repseq) & SEQNO_MASK, MAX_WINDOW);//D
904 if (((seqno - dns->repseq) & SEQNO_MASK) <= MAX_WINDOW)
909 { 905 {
906 dns->repseq = seqno;
907
908 while (dlen > 1 && !dns->snddq.empty ())
909 {
910 int txtlen = dlen <= 255 ? dlen - 1 : 255; 910 int txtlen = dlen <= 255 ? dlen - 1 : 255;
911 911
912 if (txtlen > dns->snddq.size ()) 912 if (txtlen > dns->snddq.size ())
913 txtlen = dns->snddq.size (); 913 txtlen = dns->snddq.size ();
914 914
915 pkt[offs++] = txtlen; 915 pkt[offs++] = txtlen;
916 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen); 916 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
917 offs += txtlen; 917 offs += txtlen;
918 dns->snddq.remove (txtlen); 918 dns->snddq.remove (txtlen);
919 919
920 dlen -= txtlen + 1; 920 dlen -= txtlen + 1;
921 }
921 } 922 }
922 923
923 // avoid empty TXT rdata 924 // avoid completely empty TXT rdata
924 if (offs == rdlen_offs) 925 if (offs == rdlen_offs)
925 pkt[offs++] = 0; 926 pkt[offs++] = 0;
926 927
927 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ()); 928 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
928 } 929 }
… …
1027 double latency = NOW - (*i)->sent; 1028 double latency = NOW - (*i)->sent;
1028 1029
1029 if (latency < dns->min_latency) 1030 if (latency < dns->min_latency)
1030 dns->min_latency = latency; 1031 dns->min_latency = latency;
1031 1032
1032 if (dns->send_interval > dns->min_latency * LATENCY_FACTOR) 1033 if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor)
1033 dns->send_interval = dns->min_latency * LATENCY_FACTOR; 1034 dns->send_interval = dns->min_latency * conf.dns_overlap_factor;
1034 1035
1035 if (dns->send_interval < MIN_SEND_INTERVAL) 1036 if (dns->send_interval < conf.dns_send_interval)
1036 dns->send_interval = MIN_SEND_INTERVAL; 1037 dns->send_interval = conf.dns_send_interval;
1037 } 1038 }
1038 1039
1039 delete *i; 1040 delete *i;
1040 dns_sndpq.erase (i); 1041 dns_sndpq.erase (i);
1041 1042
… …
1174} 1175}
1175 1176
1176bool 1177bool
1177vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) 1178vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
1178{ 1179{
1179 int client = ntohs (si.port); 1180 int client = ntohl (si.host);
1180 1181
1181 assert (0 < client && client <= conns.size ()); 1182 assert (0 < client && client <= conns.size ());
1182 1183
1183 connection *c = conns [client - 1]; 1184 connection *c = conns [client - 1];
1184 1185
1185 if (!c->dns) 1186 if (!c->dns)
1186 c->dns = new dns_connection (c); 1187 c->dns = new dns_connection (c);
1187 1188
1188 if (!c->dns->snddq.put (pkt)) 1189 if (c->dns->snddq.put (pkt))
1189 return false;
1190
1191 c->dns->tw.trigger (); 1190 c->dns->tw.trigger ();
1192 1191
1192 // always return true even if the buffer overflows
1193 return true; 1193 return true;
1194} 1194}
1195 1195
1196void 1196void
1197connection::dnsv4_reset_connection () 1197connection::dnsv4_reset_connection ()
… …
1223 if (!send) 1223 if (!send)
1224 { 1224 {
1225 send = r; 1225 send = r;
1226 1226
1227 r->retry++; 1227 r->retry++;
1228 r->timeout = NOW + (r->retry * min_latency * 8.); 1228 r->timeout = NOW + (r->retry * min_latency * conf.dns_timeout_factor);
1229 1229
1230 // the following code changes the query section a bit, forcing 1230 // the following code changes the query section a bit, forcing
1231 // the forwarder to generate a new request 1231 // the forwarder to generate a new request
1232 if (r->stdhdr) 1232 if (r->stdhdr)
1233 { 1233 {
… …
1252 1252
1253 cfg.reset (THISNODE->id); 1253 cfg.reset (THISNODE->id);
1254 send->gen_syn_req (); 1254 send->gen_syn_req ();
1255 } 1255 }
1256 } 1256 }
1257 else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING 1257 else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding
1258 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) 1258 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
1259 { 1259 {
1260 if (last_sent + send_interval <= NOW) 1260 if (last_sent + send_interval <= NOW)
1261 { 1261 {
1262 //printf ("sending data request etc.\n"); //D 1262 //printf ("sending data request etc.\n"); //D
… …
1266 NEXT (NOW + send_interval); 1266 NEXT (NOW + send_interval);
1267 } 1267 }
1268 1268
1269 send = new dns_snd (this); 1269 send = new dns_snd (this);
1270 send->gen_stream_req (sndseq, snddq); 1270 send->gen_stream_req (sndseq, snddq);
1271 send->timeout = NOW + min_latency * 8.; 1271 send->timeout = NOW + min_latency * conf.dns_timeout_factor;
1272 1272
1273 sndseq = (sndseq + 1) & SEQNO_MASK; 1273 sndseq = (sndseq + 1) & SEQNO_MASK;
1274 } 1274 }
1275 else 1275 else
1276 NEXT (last_sent + send_interval); 1276 NEXT (last_sent + send_interval);
… …
1292 poll_interval, send_interval, next - NOW, 1292 poll_interval, send_interval, next - NOW,
1293 vpn->dns_sndpq.size (), snddq.size (), 1293 vpn->dns_sndpq.size (), snddq.size (),
1294 rcvpq.size ()); 1294 rcvpq.size ());
1295 1295
1296 // 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
1297 // doesn't seem to happen anymore
1297 if (next < NOW + 0.001) 1298 if (next < NOW + 0.001)
1298 next = NOW + 0.1; 1299 next = NOW + 0.1;
1299 1300
1300 w.start (next); 1301 w.start (next);
1301} 1302}

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