ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/gvpe/src/vpn_dns.C
(Generate patch)

Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.30 by pcg, Mon Mar 14 17:40:01 2005 UTC vs.
Revision 1.37 by pcg, Wed Mar 23 17:03:58 2005 UTC

… …
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 INITIAL_TIMEOUT 0.1 // retry timeouts 52#define INITIAL_TIMEOUT 0.1 // retry timeouts
53#define INITIAL_SYN_TIMEOUT 10. // retry timeout for initial syn 53#define INITIAL_SYN_TIMEOUT 2. // retry timeout for initial syn
54 54
55#define MIN_SEND_INTERVAL 0.001 // wait at least this time between sending requests
56#define MAX_SEND_INTERVAL 2. // optimistic? 55#define MAX_SEND_INTERVAL 2. // optimistic?
57 56
58#define LATENCY_FACTOR 0.5 // RTT * LATENCY_FACTOR == sending rate
59#define MAX_OUTSTANDING 2 // max. outstanding requests
60#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog 57#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 58#define MAX_BACKLOG (64*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE
62 59
63#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
64// 240 leaves about 4 bytes of server reply data 61// 240 leaves about 4 bytes of server reply data
65// every two request bytes less give room for one reply byte 62// every request byte less give room for two reply bytes
66 63
67#define SEQNO_MASK 0x3fff 64#define SEQNO_MASK 0x3fff
68#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) ) 65#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )
69 66
70#define MAX_LBL_SIZE 63 67#define MAX_LBL_SIZE 63
… …
553 double min_latency; 550 double min_latency;
554 double poll_interval, send_interval; 551 double poll_interval, send_interval;
555 552
556 vector<dns_rcv *> rcvpq; 553 vector<dns_rcv *> rcvpq;
557 554
558 byte_stream rcvdq; int rcvseq; 555 byte_stream rcvdq; int rcvseq; int repseq;
559 byte_stream snddq; int sndseq; 556 byte_stream snddq; int sndseq;
560 557
561 void time_cb (time_watcher &w); time_watcher tw; 558 void time_cb (time_watcher &w); time_watcher tw;
562 void receive_rep (dns_rcv *r); 559 void receive_rep (dns_rcv *r);
563 560
… …
720///////////////////////////////////////////////////////////////////////////// 717/////////////////////////////////////////////////////////////////////////////
721 718
722dns_connection::dns_connection (connection *c) 719dns_connection::dns_connection (connection *c)
723: c (c) 720: c (c)
724, rcvdq (MAX_BACKLOG * 2) 721, rcvdq (MAX_BACKLOG * 2)
725, snddq (MAX_BACKLOG * 2) 722, snddq (MAX_BACKLOG)
726, tw (this, &dns_connection::time_cb) 723, tw (this, &dns_connection::time_cb)
727{ 724{
728 vpn = c->vpn; 725 vpn = c->vpn;
729 726
730 established = false; 727 established = false;
731 728
732 rcvseq = sndseq = 0; 729 rcvseq = repseq = sndseq = 0;
733 730
734 last_sent = last_received = 0; 731 last_sent = last_received = 0;
735 poll_interval = 0.5; // starting here 732 poll_interval = 0.5; // starting here
736 send_interval = 0.5; // starting rate 733 send_interval = 0.5; // starting rate
737 min_latency = INITIAL_TIMEOUT; 734 min_latency = INITIAL_TIMEOUT;
… …
791 } 788 }
792 789
793 while (vpn_packet *pkt = rcvdq.get ()) 790 while (vpn_packet *pkt = rcvdq.get ())
794 { 791 {
795 sockinfo si; 792 sockinfo si;
796 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;
797 794
798 vpn->recv_vpn_packet (pkt, si); 795 vpn->recv_vpn_packet (pkt, si);
799 796
800 delete pkt; 797 delete pkt;
801 } 798 }
… …
855 if (0 < client && client <= conns.size ()) 852 if (0 < client && client <= conns.size ())
856 { 853 {
857 connection *c = conns [client - 1]; 854 connection *c = conns [client - 1];
858 dns_connection *dns = c->dns; 855 dns_connection *dns = c->dns;
859 dns_rcv *rcv; 856 dns_rcv *rcv;
860 bool in_seq;
861 857
862 if (dns) 858 if (dns)
863 { 859 {
864 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 (); )
865 if (SEQNO_EQ ((*i)->seqno, seqno)) 861 if (SEQNO_EQ ((*i)->seqno, seqno))
… …
876 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);
877 873
878 goto duplicate_request; 874 goto duplicate_request;
879 } 875 }
880 876
881 in_seq = dns->rcvseq == seqno;
882
883 // new packet, queue 877 // new packet, queue
884 rcv = new dns_rcv (seqno, data, datalen); 878 rcv = new dns_rcv (seqno, data, datalen);
885 dns->receive_rep (rcv); 879 dns->receive_rep (rcv);
886 } 880 }
887 881
… …
904 dlen -= qlen; 898 dlen -= qlen;
905 899
906 // only put data into in-order sequence packets, if 900 // only put data into in-order sequence packets, if
907 // we receive out-of-order packets we generate empty 901 // we receive out-of-order packets we generate empty
908 // replies 902 // replies
909 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)
910 { 905 {
906 dns->repseq = seqno;
907
908 while (dlen > 1 && !dns->snddq.empty ())
909 {
911 int txtlen = dlen <= 255 ? dlen - 1 : 255; 910 int txtlen = dlen <= 255 ? dlen - 1 : 255;
912 911
913 if (txtlen > dns->snddq.size ()) 912 if (txtlen > dns->snddq.size ())
914 txtlen = dns->snddq.size (); 913 txtlen = dns->snddq.size ();
915 914
916 pkt[offs++] = txtlen; 915 pkt[offs++] = txtlen;
917 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen); 916 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
918 offs += txtlen; 917 offs += txtlen;
919 dns->snddq.remove (txtlen); 918 dns->snddq.remove (txtlen);
920 919
921 dlen -= txtlen + 1; 920 dlen -= txtlen + 1;
921 }
922 } 922 }
923 923
924 // avoid empty TXT rdata 924 // avoid completely empty TXT rdata
925 if (offs == rdlen_offs) 925 if (offs == rdlen_offs)
926 pkt[offs++] = 0; 926 pkt[offs++] = 0;
927 927
928 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ()); 928 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
929 } 929 }
… …
1028 double latency = NOW - (*i)->sent; 1028 double latency = NOW - (*i)->sent;
1029 1029
1030 if (latency < dns->min_latency) 1030 if (latency < dns->min_latency)
1031 dns->min_latency = latency; 1031 dns->min_latency = latency;
1032 1032
1033 if (dns->send_interval > dns->min_latency * LATENCY_FACTOR) 1033 if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor)
1034 dns->send_interval = dns->min_latency * LATENCY_FACTOR; 1034 dns->send_interval = dns->min_latency * conf.dns_overlap_factor;
1035 1035
1036 if (dns->send_interval < MIN_SEND_INTERVAL) 1036 if (dns->send_interval < conf.dns_send_interval)
1037 dns->send_interval = MIN_SEND_INTERVAL; 1037 dns->send_interval = conf.dns_send_interval;
1038 } 1038 }
1039 1039
1040 delete *i; 1040 delete *i;
1041 dns_sndpq.erase (i); 1041 dns_sndpq.erase (i);
1042 1042
… …
1175} 1175}
1176 1176
1177bool 1177bool
1178vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) 1178vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
1179{ 1179{
1180 int client = ntohs (si.port); 1180 int client = ntohl (si.host);
1181 1181
1182 assert (0 < client && client <= conns.size ()); 1182 assert (0 < client && client <= conns.size ());
1183 1183
1184 connection *c = conns [client - 1]; 1184 connection *c = conns [client - 1];
1185 1185
1186 if (!c->dns) 1186 if (!c->dns)
1187 c->dns = new dns_connection (c); 1187 c->dns = new dns_connection (c);
1188 1188
1189 if (!c->dns->snddq.put (pkt)) 1189 if (c->dns->snddq.put (pkt))
1190 return false;
1191
1192 c->dns->tw.trigger (); 1190 c->dns->tw.trigger ();
1193 1191
1192 // always return true even if the buffer overflows
1194 return true; 1193 return true;
1195} 1194}
1196 1195
1197void 1196void
1198connection::dnsv4_reset_connection () 1197connection::dnsv4_reset_connection ()
… …
1224 if (!send) 1223 if (!send)
1225 { 1224 {
1226 send = r; 1225 send = r;
1227 1226
1228 r->retry++; 1227 r->retry++;
1229 r->timeout = NOW + (r->retry * min_latency * 8.); 1228 r->timeout = NOW + (r->retry * min_latency * conf.dns_timeout_factor);
1230 1229
1231 // the following code changes the query section a bit, forcing 1230 // the following code changes the query section a bit, forcing
1232 // the forwarder to generate a new request 1231 // the forwarder to generate a new request
1233 if (r->stdhdr) 1232 if (r->stdhdr)
1234 { 1233 {
… …
1253 1252
1254 cfg.reset (THISNODE->id); 1253 cfg.reset (THISNODE->id);
1255 send->gen_syn_req (); 1254 send->gen_syn_req ();
1256 } 1255 }
1257 } 1256 }
1258 else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING 1257 else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding
1259 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) 1258 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
1260 { 1259 {
1261 if (last_sent + send_interval <= NOW) 1260 if (last_sent + send_interval <= NOW)
1262 { 1261 {
1263 //printf ("sending data request etc.\n"); //D 1262 //printf ("sending data request etc.\n"); //D
… …
1267 NEXT (NOW + send_interval); 1266 NEXT (NOW + send_interval);
1268 } 1267 }
1269 1268
1270 send = new dns_snd (this); 1269 send = new dns_snd (this);
1271 send->gen_stream_req (sndseq, snddq); 1270 send->gen_stream_req (sndseq, snddq);
1272 send->timeout = NOW + min_latency * 8.; 1271 send->timeout = NOW + min_latency * conf.dns_timeout_factor;
1273 1272
1274 sndseq = (sndseq + 1) & SEQNO_MASK; 1273 sndseq = (sndseq + 1) & SEQNO_MASK;
1275 } 1274 }
1276 else 1275 else
1277 NEXT (last_sent + send_interval); 1276 NEXT (last_sent + send_interval);
… …
1293 poll_interval, send_interval, next - NOW, 1292 poll_interval, send_interval, next - NOW,
1294 vpn->dns_sndpq.size (), snddq.size (), 1293 vpn->dns_sndpq.size (), snddq.size (),
1295 rcvpq.size ()); 1294 rcvpq.size ());
1296 1295
1297 // 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
1298 if (next < NOW + 0.001) 1298 if (next < NOW + 0.001)
1299 next = NOW + 0.1; 1299 next = NOW + 0.1;
1300 1300
1301 w.start (next); 1301 w.start (next);
1302} 1302}

Diff Legend

– Removed lines
+ Added lines
< Changed lines
> Changed lines