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Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.42 by pcg, Sat Nov 10 05:14:22 2007 UTC vs.
Revision 1.47 by pcg, Thu Aug 7 17:54:27 2008 UTC

1/* 1/*
2 vpn_dns.C -- handle the dns tunnel part of the protocol. 2 vpn_dns.C -- handle the dns tunnel part of the protocol.
3 Copyright (C) 2003-2005 Marc Lehmann <gvpe@schmorp.de> 3 Copyright (C) 2003-2008 Marc Lehmann <gvpe@schmorp.de>
4 4
5 This file is part of GVPE. 5 This file is part of GVPE.
6 6
7 GVPE is free software; you can redistribute it and/or modify 7 GVPE is free software; you can redistribute it and/or modify it
8 it under the terms of the GNU General Public License as published by 8 under the terms of the GNU General Public License as published by the
9 the Free Software Foundation; either version 2 of the License, or 9 Free Software Foundation; either version 3 of the License, or (at your
10 (at your option) any later version. 10 option) any later version.
11 11
12 This program is distributed in the hope that it will be useful, 12 This program is distributed in the hope that it will be useful, but
13 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
15 GNU General Public License for more details. 15 Public License for more details.
16 16
17 You should have received a copy of the GNU General Public License 17 You should have received a copy of the GNU General Public License along
18 along with gvpe; if not, write to the Free Software 18 with this program; if not, see <http://www.gnu.org/licenses/>.
19 Foundation, Inc. 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 19
20 Additional permission under GNU GPL version 3 section 7
21
22 If you modify this Program, or any covered work, by linking or
23 combining it with the OpenSSL project's OpenSSL library (or a modified
24 version of that library), containing parts covered by the terms of the
25 OpenSSL or SSLeay licenses, the licensors of this Program grant you
26 additional permission to convey the resulting work. Corresponding
27 Source for a non-source form of such a combination shall include the
28 source code for the parts of OpenSSL used as well as that of the
29 covered work.
20*/ 30*/
21 31
22// TODO: EDNS0 option to increase dns mtu? 32// TODO: EDNS0 option to increase dns mtu?
23// TODO: re-write dns packet parsing/creation using a safe mem-buffer 33// TODO: re-write dns packet parsing/creation using a safe mem-buffer
24// to ensure no buffer overflows or similar problems. 34// to ensure no buffer overflows or similar problems.
… …
42#include <unistd.h> 52#include <unistd.h>
43#include <fcntl.h> 53#include <fcntl.h>
44 54
45#include <map> 55#include <map>
46 56
57#include <cstdio> /* bug in libgmp: gmp.h relies on cstdio being included */
47#include <gmp.h> 58#include <gmp.h>
48 59
49#include "netcompat.h" 60#include "netcompat.h"
50 61
51#include "vpn.h" 62#include "vpn.h"
… …
559 vector<dns_rcv *> rcvpq; 570 vector<dns_rcv *> rcvpq;
560 571
561 byte_stream rcvdq; int rcvseq; int repseq; 572 byte_stream rcvdq; int rcvseq; int repseq;
562 byte_stream snddq; int sndseq; 573 byte_stream snddq; int sndseq;
563 574
564 void time_cb (ev::timer &w, int revents); ev::timer tw; 575 inline void time_cb (ev::timer &w, int revents); ev::timer tw;
565 void receive_rep (dns_rcv *r); 576 void receive_rep (dns_rcv *r);
566 577
567 dns_connection (connection *c); 578 dns_connection (connection *c);
568 ~dns_connection (); 579 ~dns_connection ();
569}; 580};
… …
588: dns (dns) 599: dns (dns)
589{ 600{
590 timeout = 0; 601 timeout = 0;
591 retry = 0; 602 retry = 0;
592 seqno = 0; 603 seqno = 0;
593 sent = ev::ev_now (); 604 sent = ev_now ();
594 stdhdr = false; 605 stdhdr = false;
595 606
596 pkt = new dns_packet; 607 pkt = new dns_packet;
597 608
598 pkt->id = next_id (); 609 pkt->id = next_id ();
… …
629void dns_snd::gen_stream_req (int seqno, byte_stream &stream) 640void dns_snd::gen_stream_req (int seqno, byte_stream &stream)
630{ 641{
631 stdhdr = true; 642 stdhdr = true;
632 this->seqno = seqno; 643 this->seqno = seqno;
633 644
634 timeout = ev::ev_now () + INITIAL_TIMEOUT; 645 timeout = ev_now () + INITIAL_TIMEOUT;
635 646
636 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 647 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
637 pkt->qdcount = htons (1); 648 pkt->qdcount = htons (1);
638 649
639 int offs = 6*2; 650 int offs = 6*2;
… …
674 pkt->len = offs; 685 pkt->len = offs;
675} 686}
676 687
677void dns_snd::gen_syn_req () 688void dns_snd::gen_syn_req ()
678{ 689{
679 timeout = ev::ev_now () + INITIAL_SYN_TIMEOUT; 690 timeout = ev_now () + INITIAL_SYN_TIMEOUT;
680 691
681 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 692 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
682 pkt->qdcount = htons (1); 693 pkt->qdcount = htons (1);
683 694
684 int offs = 6 * 2; 695 int offs = 6 * 2;
… …
724 735
725dns_connection::dns_connection (connection *c) 736dns_connection::dns_connection (connection *c)
726: c (c) 737: c (c)
727, rcvdq (MAX_BACKLOG * 2) 738, rcvdq (MAX_BACKLOG * 2)
728, snddq (MAX_BACKLOG) 739, snddq (MAX_BACKLOG)
729, tw (this, &dns_connection::time_cb)
730{ 740{
741 tw.set<dns_connection, &dns_connection::time_cb> (this);
742
731 vpn = c->vpn; 743 vpn = c->vpn;
732 744
733 established = false; 745 established = false;
734 746
735 rcvseq = repseq = sndseq = 0; 747 rcvseq = repseq = sndseq = 0;
… …
750 762
751void dns_connection::receive_rep (dns_rcv *r) 763void dns_connection::receive_rep (dns_rcv *r)
752{ 764{
753 if (r->datalen) 765 if (r->datalen)
754 { 766 {
755 last_received = ev::ev_now (); 767 last_received = ev_now ();
756 tw (); 768 tw ();
757 769
758 poll_interval = send_interval; 770 poll_interval = send_interval;
759 } 771 }
760 else 772 else
… …
1032#if 0 1044#if 0
1033 dns->send_interval *= 0.999; 1045 dns->send_interval *= 0.999;
1034#endif 1046#endif
1035 // the latency surely puts an upper bound on 1047 // the latency surely puts an upper bound on
1036 // the minimum send interval 1048 // the minimum send interval
1037 double latency = ev::ev_now () - (*i)->sent; 1049 double latency = ev_now () - (*i)->sent;
1038 1050
1039 if (latency < dns->min_latency) 1051 if (latency < dns->min_latency)
1040 dns->min_latency = latency; 1052 dns->min_latency = latency;
1041 1053
1042 if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor) 1054 if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor)
… …
1225 i != vpn->dns_sndpq.end (); 1237 i != vpn->dns_sndpq.end ();
1226 ++i) 1238 ++i)
1227 { 1239 {
1228 dns_snd *r = *i; 1240 dns_snd *r = *i;
1229 1241
1230 if (r->timeout <= ev::ev_now ()) 1242 if (r->timeout <= ev_now ())
1231 { 1243 {
1232 if (!send) 1244 if (!send)
1233 { 1245 {
1234 send = r; 1246 send = r;
1235 1247
1236 r->retry++; 1248 r->retry++;
1237 r->timeout = ev::ev_now () + (r->retry * min_latency * conf.dns_timeout_factor); 1249 r->timeout = ev_now () + (r->retry * min_latency * conf.dns_timeout_factor);
1238 //printf ("RETRY %x (%d, %f)\n", r->seqno, r->retry, r->timeout - ev::ev_now ());//D 1250 //printf ("RETRY %x (%d, %f)\n", r->seqno, r->retry, r->timeout - ev_now ());//D
1239 1251
1240 // the following code changes the query section a bit, forcing 1252 // the following code changes the query section a bit, forcing
1241 // the forwarder to generate a new request 1253 // the forwarder to generate a new request
1242 if (r->stdhdr) 1254 if (r->stdhdr)
1243 encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry); 1255 encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry);
… …
1262 } 1274 }
1263 } 1275 }
1264 else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding 1276 else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding
1265 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) 1277 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
1266 { 1278 {
1267 if (last_sent + send_interval <= ev::ev_now ()) 1279 if (last_sent + send_interval <= ev_now ())
1268 { 1280 {
1269 //printf ("sending data request etc.\n"); //D 1281 //printf ("sending data request etc.\n"); //D
1270 if (!snddq.empty () || last_received + 1. > ev::ev_now ()) 1282 if (!snddq.empty () || last_received + 1. > ev_now ())
1271 { 1283 {
1272 poll_interval = send_interval; 1284 poll_interval = send_interval;
1273 NEXT (ev::ev_now () + send_interval); 1285 NEXT (ev_now () + send_interval);
1274 } 1286 }
1275 1287
1276 send = new dns_snd (this); 1288 send = new dns_snd (this);
1277 send->gen_stream_req (sndseq, snddq); 1289 send->gen_stream_req (sndseq, snddq);
1278 send->timeout = ev::ev_now () + min_latency * conf.dns_timeout_factor; 1290 send->timeout = ev_now () + min_latency * conf.dns_timeout_factor;
1279 //printf ("SEND %x (%f)\n", send->seqno, send->timeout - ev::ev_now (), min_latency, conf.dns_timeout_factor);//D 1291 //printf ("SEND %x (%f)\n", send->seqno, send->timeout - ev_now (), min_latency, conf.dns_timeout_factor);//D
1280 1292
1281 sndseq = (sndseq + 1) & SEQNO_MASK; 1293 sndseq = (sndseq + 1) & SEQNO_MASK;
1282 } 1294 }
1283 else 1295 else
1284 NEXT (last_sent + send_interval); 1296 NEXT (last_sent + send_interval);
… …
1288 vpn->dns_sndpq.push_back (send); 1300 vpn->dns_sndpq.push_back (send);
1289 } 1301 }
1290 1302
1291 if (send) 1303 if (send)
1292 { 1304 {
1293 last_sent = ev::ev_now (); 1305 last_sent = ev_now ();
1294 sendto (vpn->dnsv4_fd, 1306 sendto (vpn->dnsv4_fd,
1295 send->pkt->at (0), send->pkt->len, 0, 1307 send->pkt->at (0), send->pkt->len, 0,
1296 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); 1308 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
1297 } 1309 }
1298 1310
1299 slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)", 1311 slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)",
1300 poll_interval, send_interval, next - ev::ev_now (), 1312 poll_interval, send_interval, next - ev_now (),
1301 vpn->dns_sndpq.size (), snddq.size (), 1313 vpn->dns_sndpq.size (), snddq.size (),
1302 rcvpq.size ()); 1314 rcvpq.size ());
1303 1315
1304 // TODO: no idea when this happens, but when next < ev::ev_now (), we have a problem 1316 // TODO: no idea when this happens, but when next < ev_now (), we have a problem
1305 // doesn't seem to happen anymore 1317 // doesn't seem to happen anymore
1306 if (next < ev::ev_now () + 0.001) 1318 if (next < ev_now () + 0.001)
1307 next = ev::ev_now () + 0.1; 1319 next = ev_now () + 0.1;
1308 1320
1309 w.start (next - ev::ev_now ()); 1321 w.start (next - ev_now ());
1310} 1322}
1311 1323
1312#endif 1324#endif
1313 1325

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