… | |
… | |
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. |
|
|
51 | |
|
|
52 | #define TIMEOUT_FACTOR 2. |
52 | |
53 | |
53 | #define INITIAL_TIMEOUT 0.1 // retry timeouts |
54 | #define INITIAL_TIMEOUT 0.1 // retry timeouts |
54 | #define INITIAL_SYN_TIMEOUT 10. // retry timeout for initial syn |
55 | #define INITIAL_SYN_TIMEOUT 10. // retry timeout for initial syn |
55 | |
56 | |
56 | #define MIN_SEND_INTERVAL 0.01 // wait at least this time between sending requests |
57 | #define MIN_SEND_INTERVAL 0.001 // wait at least this time between sending requests |
57 | #define MAX_SEND_INTERVAL 0.5 // optimistic? |
58 | #define MAX_SEND_INTERVAL 2. // optimistic? |
58 | |
59 | |
59 | #define LATENCY_FACTOR 0.5 // RTT * LATENCY_FACTOR == sending rate |
60 | #define LATENCY_FACTOR 0.5 // RTT * LATENCY_FACTOR == sending rate |
60 | #define MAX_OUTSTANDING 20 // max. outstanding requests |
61 | #define MAX_OUTSTANDING 100 // max. outstanding requests |
61 | #define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog |
62 | #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 |
63 | #define MAX_BACKLOG (32*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE |
63 | |
64 | |
64 | #define MAX_DOMAIN_SIZE 200 // 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 |
65 | // 240 leaves about 4 bytes of server reply data |
66 | // 240 leaves about 4 bytes of server reply data |
66 | // every two request bytes less give room for one reply byte |
67 | // every two request bytes less give room for one reply byte |
67 | |
68 | |
68 | #define SEQNO_MASK 0x3fff |
69 | #define SEQNO_MASK 0x0fff |
69 | #define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) ) |
70 | #define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) ) |
70 | |
71 | |
71 | #define MAX_LBL_SIZE 63 |
72 | #define MAX_LBL_SIZE 63 |
72 | #define MAX_PKT_SIZE 512 |
73 | #define MAX_PKT_SIZE 512 |
73 | |
74 | |
… | |
… | |
424 | u16 max_size; |
425 | u16 max_size; |
425 | u8 seq_cdc; |
426 | u8 seq_cdc; |
426 | u8 req_cdc; |
427 | u8 req_cdc; |
427 | |
428 | |
428 | u8 rep_cdc; |
429 | u8 rep_cdc; |
|
|
430 | u8 delay; // time in 0.01s units that the server may delay replying packets |
429 | u8 r2, r3, r4; |
431 | u8 r3, r4; |
430 | |
432 | |
431 | u8 r5, r6, r7, r8; |
433 | u8 r5, r6, r7, r8; |
432 | |
434 | |
433 | void reset (int clientid); |
435 | void reset (int clientid); |
434 | bool valid (); |
436 | bool valid (); |
… | |
… | |
449 | flags = 0; |
451 | flags = 0; |
450 | def_ttl = 0; |
452 | def_ttl = 0; |
451 | seq_cdc = 26; |
453 | seq_cdc = 26; |
452 | req_cdc = 62; |
454 | req_cdc = 62; |
453 | rep_cdc = 0; |
455 | rep_cdc = 0; |
454 | max_size = ntohs (MAX_PKT_SIZE); |
456 | max_size = htons (MAX_PKT_SIZE); |
455 | client = ntohs (clientid); |
457 | client = htons (clientid); |
456 | uid = next_uid++; |
458 | uid = next_uid++; |
|
|
459 | delay = 0; |
457 | |
460 | |
458 | r2 = r3 = r4 = 0; |
461 | r3 = r4 = 0; |
459 | r4 = r5 = r6 = r7 = 0; |
462 | r4 = r5 = r6 = r7 = 0; |
460 | } |
463 | } |
461 | |
464 | |
462 | bool dns_cfg::valid () |
465 | bool dns_cfg::valid () |
463 | { |
466 | { |
… | |
… | |
466 | && id3 == 'P' |
469 | && id3 == 'P' |
467 | && id4 == 'E' |
470 | && id4 == 'E' |
468 | && seq_cdc == 26 |
471 | && seq_cdc == 26 |
469 | && req_cdc == 62 |
472 | && req_cdc == 62 |
470 | && rep_cdc == 0 |
473 | && rep_cdc == 0 |
471 | && version == 1 |
474 | && version == 1; |
472 | && max_size == ntohs (MAX_PKT_SIZE); |
|
|
473 | } |
475 | } |
474 | |
476 | |
475 | struct dns_packet : net_packet |
477 | struct dns_packet : net_packet |
476 | { |
478 | { |
477 | u16 id; |
479 | u16 id; |
… | |
… | |
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 | |
722 | dns_connection::dns_connection (connection *c) |
724 | dns_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 = MIN_POLL_INTERVAL; |
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; |
738 | } |
740 | } |
739 | |
741 | |
740 | dns_connection::~dns_connection () |
742 | dns_connection::~dns_connection () |
… | |
… | |
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 | |
… | |
… | |
894 | pkt [offs++] = 0; pkt [offs++] = 0; |
893 | pkt [offs++] = 0; pkt [offs++] = 0; |
895 | pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL |
894 | pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL |
896 | |
895 | |
897 | int rdlen_offs = offs += 2; |
896 | int rdlen_offs = offs += 2; |
898 | |
897 | |
899 | int dlen = (dns ? ntohs (dns->cfg.max_size) : MAX_PKT_SIZE) - offs; |
|
|
900 | // bind doesn't compress well, so reduce further by one label length |
|
|
901 | dlen -= qlen; |
|
|
902 | |
|
|
903 | if (dns) |
898 | if (dns) |
904 | { |
899 | { |
|
|
900 | int dlen = ntohs (dns->cfg.max_size) - offs; |
|
|
901 | |
|
|
902 | // bind doesn't compress well, so reduce further by one label length |
|
|
903 | dlen -= qlen; |
|
|
904 | |
905 | // only put data into in-order sequence packets, if |
905 | // only put data into in-order sequence packets, if |
906 | // we receive out-of-order packets we generate empty |
906 | // we receive out-of-order packets we generate empty |
907 | // replies |
907 | // replies |
908 | 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) |
909 | { |
910 | { |
|
|
911 | dns->repseq = seqno; |
|
|
912 | |
|
|
913 | while (dlen > 1 && !dns->snddq.empty ()) |
|
|
914 | { |
910 | int txtlen = dlen <= 255 ? dlen - 1 : 255; |
915 | int txtlen = dlen <= 255 ? dlen - 1 : 255; |
911 | |
916 | |
912 | if (txtlen > dns->snddq.size ()) |
917 | if (txtlen > dns->snddq.size ()) |
913 | txtlen = dns->snddq.size (); |
918 | txtlen = dns->snddq.size (); |
914 | |
919 | |
915 | pkt[offs++] = txtlen; |
920 | pkt[offs++] = txtlen; |
916 | memcpy (pkt.at (offs), dns->snddq.begin (), txtlen); |
921 | memcpy (pkt.at (offs), dns->snddq.begin (), txtlen); |
917 | offs += txtlen; |
922 | offs += txtlen; |
918 | dns->snddq.remove (txtlen); |
923 | dns->snddq.remove (txtlen); |
919 | |
924 | |
920 | dlen -= txtlen + 1; |
925 | dlen -= txtlen + 1; |
|
|
926 | } |
921 | } |
927 | } |
922 | |
928 | |
923 | // avoid empty TXT rdata |
929 | // avoid completely empty TXT rdata |
924 | if (offs == rdlen_offs) |
930 | if (offs == rdlen_offs) |
925 | pkt[offs++] = 0; |
931 | pkt[offs++] = 0; |
926 | |
932 | |
927 | slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ()); |
933 | slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ()); |
928 | } |
934 | } |
… | |
… | |
1017 | if (dns->send_interval > MAX_SEND_INTERVAL) |
1023 | if (dns->send_interval > MAX_SEND_INTERVAL) |
1018 | dns->send_interval = MAX_SEND_INTERVAL; |
1024 | dns->send_interval = MAX_SEND_INTERVAL; |
1019 | } |
1025 | } |
1020 | else |
1026 | else |
1021 | { |
1027 | { |
1022 | #if 1 |
1028 | #if 0 |
1023 | dns->send_interval *= 0.999; |
1029 | dns->send_interval *= 0.999; |
1024 | #endif |
1030 | #endif |
1025 | if (dns->send_interval < MIN_SEND_INTERVAL) |
|
|
1026 | dns->send_interval = MIN_SEND_INTERVAL; |
|
|
1027 | |
|
|
1028 | // the latency surely puts an upper bound on |
1031 | // the latency surely puts an upper bound on |
1029 | // the minimum send interval |
1032 | // the minimum send interval |
1030 | double latency = NOW - (*i)->sent; |
1033 | double latency = NOW - (*i)->sent; |
1031 | |
1034 | |
1032 | if (latency < dns->min_latency) |
1035 | if (latency < dns->min_latency) |
1033 | dns->min_latency = latency; |
1036 | dns->min_latency = latency; |
1034 | |
1037 | |
1035 | if (dns->send_interval > dns->min_latency * LATENCY_FACTOR) |
1038 | if (dns->send_interval > dns->min_latency * LATENCY_FACTOR) |
1036 | dns->send_interval = dns->min_latency * LATENCY_FACTOR; |
1039 | dns->send_interval = dns->min_latency * LATENCY_FACTOR; |
|
|
1040 | |
|
|
1041 | if (dns->send_interval < MIN_SEND_INTERVAL) |
|
|
1042 | dns->send_interval = MIN_SEND_INTERVAL; |
1037 | } |
1043 | } |
1038 | |
1044 | |
1039 | delete *i; |
1045 | delete *i; |
1040 | dns_sndpq.erase (i); |
1046 | dns_sndpq.erase (i); |
1041 | |
1047 | |
… | |
… | |
1183 | connection *c = conns [client - 1]; |
1189 | connection *c = conns [client - 1]; |
1184 | |
1190 | |
1185 | if (!c->dns) |
1191 | if (!c->dns) |
1186 | c->dns = new dns_connection (c); |
1192 | c->dns = new dns_connection (c); |
1187 | |
1193 | |
1188 | if (!c->dns->snddq.put (pkt)) |
1194 | if (c->dns->snddq.put (pkt)) |
1189 | return false; |
|
|
1190 | |
|
|
1191 | c->dns->tw.trigger (); |
1195 | c->dns->tw.trigger (); |
1192 | |
1196 | |
|
|
1197 | // always return true even if the buffer overflows |
1193 | return true; |
1198 | return true; |
1194 | } |
1199 | } |
1195 | |
1200 | |
1196 | void |
1201 | void |
1197 | connection::dnsv4_reset_connection () |
1202 | connection::dnsv4_reset_connection () |
… | |
… | |
1223 | if (!send) |
1228 | if (!send) |
1224 | { |
1229 | { |
1225 | send = r; |
1230 | send = r; |
1226 | |
1231 | |
1227 | r->retry++; |
1232 | r->retry++; |
1228 | r->timeout = NOW + (r->retry * min_latency * 8.); |
1233 | r->timeout = NOW + (r->retry * min_latency * TIMEOUT_FACTOR); |
1229 | |
1234 | |
1230 | // the following code changes the query section a bit, forcing |
1235 | // the following code changes the query section a bit, forcing |
1231 | // the forwarder to generate a new request |
1236 | // the forwarder to generate a new request |
1232 | if (r->stdhdr) |
1237 | if (r->stdhdr) |
1233 | { |
1238 | { |
1234 | //printf ("reencoded header for ID %d retry %d:%d:%d\n", htons (r->pkt->id), THISNODE->id, r->seqno, r->retry);printf ("reencoded header for ID %d retry %d:%d:%d\n", htons (r->pkt->id), THISNODE->id, r->seqno, r->retry); |
1239 | //printf ("reencoded header for ID %d retry %d:%d:%d (%p)\n", htons (r->pkt->id), THISNODE->id, r->seqno, r->retry); |
1235 | //encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry); |
1240 | //encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry); |
1236 | } |
1241 | } |
1237 | } |
1242 | } |
1238 | } |
1243 | } |
1239 | else |
1244 | else |
1240 | NEXT (r->timeout); |
1245 | NEXT (r->timeout); |
1241 | } |
1246 | } |
1242 | |
1247 | |
1243 | if (last_sent + send_interval <= NOW) |
|
|
1244 | { |
|
|
1245 | if (!send) |
1248 | if (!send) |
|
|
1249 | { |
|
|
1250 | // generate a new packet, if wise |
|
|
1251 | |
|
|
1252 | if (!established) |
1246 | { |
1253 | { |
1247 | // generate a new packet, if wise |
1254 | if (vpn->dns_sndpq.empty ()) |
1248 | |
|
|
1249 | if (!established) |
|
|
1250 | { |
1255 | { |
1251 | if (vpn->dns_sndpq.empty ()) |
|
|
1252 | { |
|
|
1253 | send = new dns_snd (this); |
1256 | send = new dns_snd (this); |
1254 | |
1257 | |
1255 | cfg.reset (THISNODE->id); |
1258 | cfg.reset (THISNODE->id); |
1256 | send->gen_syn_req (); |
1259 | send->gen_syn_req (); |
1257 | } |
|
|
1258 | } |
1260 | } |
|
|
1261 | } |
1259 | else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING |
1262 | else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING |
1260 | && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) |
1263 | && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) |
|
|
1264 | { |
|
|
1265 | if (last_sent + send_interval <= NOW) |
1261 | { |
1266 | { |
1262 | //printf ("sending data request etc.\n"); //D |
1267 | //printf ("sending data request etc.\n"); //D |
1263 | if (!snddq.empty () || last_received + 1. > NOW) |
1268 | if (!snddq.empty () || last_received + 1. > NOW) |
1264 | { |
1269 | { |
1265 | poll_interval = send_interval; |
1270 | poll_interval = send_interval; |
1266 | NEXT (NOW + send_interval); |
1271 | NEXT (NOW + send_interval); |
1267 | } |
1272 | } |
1268 | |
1273 | |
1269 | send = new dns_snd (this); |
1274 | send = new dns_snd (this); |
1270 | send->gen_stream_req (sndseq, snddq); |
1275 | send->gen_stream_req (sndseq, snddq); |
1271 | send->timeout = NOW + min_latency * 8.; |
1276 | send->timeout = NOW + min_latency * TIMEOUT_FACTOR; |
1272 | |
1277 | |
1273 | sndseq = (sndseq + 1) & SEQNO_MASK; |
1278 | sndseq = (sndseq + 1) & SEQNO_MASK; |
1274 | } |
1279 | } |
1275 | |
1280 | else |
1276 | if (send) |
1281 | NEXT (last_sent + send_interval); |
1277 | vpn->dns_sndpq.push_back (send); |
|
|
1278 | } |
1282 | } |
1279 | |
1283 | |
1280 | if (send) |
1284 | if (send) |
1281 | { |
1285 | vpn->dns_sndpq.push_back (send); |
|
|
1286 | } |
|
|
1287 | |
|
|
1288 | if (send) |
|
|
1289 | { |
1282 | last_sent = NOW; |
1290 | last_sent = NOW; |
|
|
1291 | if (rand () & 15 != 0)//D |
1283 | sendto (vpn->dnsv4_fd, |
1292 | sendto (vpn->dnsv4_fd, |
1284 | send->pkt->at (0), send->pkt->len, 0, |
1293 | send->pkt->at (0), send->pkt->len, 0, |
1285 | vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); |
1294 | vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); |
1286 | } |
|
|
1287 | } |
1295 | } |
1288 | else |
|
|
1289 | NEXT (last_sent + send_interval); |
|
|
1290 | |
1296 | |
1291 | slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d)", |
1297 | slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)", |
1292 | poll_interval, send_interval, next - NOW, |
1298 | poll_interval, send_interval, next - NOW, |
1293 | vpn->dns_sndpq.size (), snddq.size ()); |
1299 | vpn->dns_sndpq.size (), snddq.size (), |
|
|
1300 | rcvpq.size ()); |
1294 | |
1301 | |
1295 | // TODO: no idea when this happens, but when next < NOW, we have a problem |
1302 | // TODO: no idea when this happens, but when next < NOW, we have a problem |
1296 | if (next < NOW + 0.0001) |
1303 | if (next < NOW + 0.001) |
1297 | next = NOW + 0.1; |
1304 | next = NOW + 0.1; |
1298 | |
1305 | |
1299 | w.start (next); |
1306 | w.start (next); |
1300 | } |
1307 | } |
1301 | |
1308 | |