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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 1.48 by pcg, Tue Jul 28 00:42:14 2009 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"
… …
72#define MAX_PKT_SIZE 512 83#define MAX_PKT_SIZE 512
73 84
74#define RR_TYPE_A 1 85#define RR_TYPE_A 1
75#define RR_TYPE_NULL 10 86#define RR_TYPE_NULL 10
76#define RR_TYPE_TXT 16 87#define RR_TYPE_TXT 16
88#define RR_TYPE_AAAA 28
77#define RR_TYPE_ANY 255 89#define RR_TYPE_ANY 255
78 90
79#define RR_CLASS_IN 1 91#define RR_CLASS_IN 1
80 92
81#define CMD_IP_1 207 93#define CMD_IP_1 207
… …
559 vector<dns_rcv *> rcvpq; 571 vector<dns_rcv *> rcvpq;
560 572
561 byte_stream rcvdq; int rcvseq; int repseq; 573 byte_stream rcvdq; int rcvseq; int repseq;
562 byte_stream snddq; int sndseq; 574 byte_stream snddq; int sndseq;
563 575
564 void time_cb (ev::timer &w, int revents); ev::timer tw; 576 inline void time_cb (ev::timer &w, int revents); ev::timer tw;
565 void receive_rep (dns_rcv *r); 577 void receive_rep (dns_rcv *r);
566 578
567 dns_connection (connection *c); 579 dns_connection (connection *c);
568 ~dns_connection (); 580 ~dns_connection ();
569}; 581};
… …
588: dns (dns) 600: dns (dns)
589{ 601{
590 timeout = 0; 602 timeout = 0;
591 retry = 0; 603 retry = 0;
592 seqno = 0; 604 seqno = 0;
593 sent = ev::ev_now (); 605 sent = ev_now ();
594 stdhdr = false; 606 stdhdr = false;
595 607
596 pkt = new dns_packet; 608 pkt = new dns_packet;
597 609
598 pkt->id = next_id (); 610 pkt->id = next_id ();
… …
629void dns_snd::gen_stream_req (int seqno, byte_stream &stream) 641void dns_snd::gen_stream_req (int seqno, byte_stream &stream)
630{ 642{
631 stdhdr = true; 643 stdhdr = true;
632 this->seqno = seqno; 644 this->seqno = seqno;
633 645
634 timeout = ev::ev_now () + INITIAL_TIMEOUT; 646 timeout = ev_now () + INITIAL_TIMEOUT;
635 647
636 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 648 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
637 pkt->qdcount = htons (1); 649 pkt->qdcount = htons (1);
638 650
639 int offs = 6*2; 651 int offs = 6*2;
… …
674 pkt->len = offs; 686 pkt->len = offs;
675} 687}
676 688
677void dns_snd::gen_syn_req () 689void dns_snd::gen_syn_req ()
678{ 690{
679 timeout = ev::ev_now () + INITIAL_SYN_TIMEOUT; 691 timeout = ev_now () + INITIAL_SYN_TIMEOUT;
680 692
681 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 693 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
682 pkt->qdcount = htons (1); 694 pkt->qdcount = htons (1);
683 695
684 int offs = 6 * 2; 696 int offs = 6 * 2;
… …
724 736
725dns_connection::dns_connection (connection *c) 737dns_connection::dns_connection (connection *c)
726: c (c) 738: c (c)
727, rcvdq (MAX_BACKLOG * 2) 739, rcvdq (MAX_BACKLOG * 2)
728, snddq (MAX_BACKLOG) 740, snddq (MAX_BACKLOG)
729, tw (this, &dns_connection::time_cb)
730{ 741{
742 tw.set<dns_connection, &dns_connection::time_cb> (this);
743
731 vpn = c->vpn; 744 vpn = c->vpn;
732 745
733 established = false; 746 established = false;
734 747
735 rcvseq = repseq = sndseq = 0; 748 rcvseq = repseq = sndseq = 0;
… …
750 763
751void dns_connection::receive_rep (dns_rcv *r) 764void dns_connection::receive_rep (dns_rcv *r)
752{ 765{
753 if (r->datalen) 766 if (r->datalen)
754 { 767 {
755 last_received = ev::ev_now (); 768 last_received = ev_now ();
756 tw (); 769 tw ();
757 770
758 poll_interval = send_interval; 771 poll_interval = send_interval;
759 } 772 }
760 else 773 else
… …
1032#if 0 1045#if 0
1033 dns->send_interval *= 0.999; 1046 dns->send_interval *= 0.999;
1034#endif 1047#endif
1035 // the latency surely puts an upper bound on 1048 // the latency surely puts an upper bound on
1036 // the minimum send interval 1049 // the minimum send interval
1037 double latency = ev::ev_now () - (*i)->sent; 1050 double latency = ev_now () - (*i)->sent;
1038 1051
1039 if (latency < dns->min_latency) 1052 if (latency < dns->min_latency)
1040 dns->min_latency = latency; 1053 dns->min_latency = latency;
1041 1054
1042 if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor) 1055 if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor)
… …
1225 i != vpn->dns_sndpq.end (); 1238 i != vpn->dns_sndpq.end ();
1226 ++i) 1239 ++i)
1227 { 1240 {
1228 dns_snd *r = *i; 1241 dns_snd *r = *i;
1229 1242
1230 if (r->timeout <= ev::ev_now ()) 1243 if (r->timeout <= ev_now ())
1231 { 1244 {
1232 if (!send) 1245 if (!send)
1233 { 1246 {
1234 send = r; 1247 send = r;
1235 1248
1236 r->retry++; 1249 r->retry++;
1237 r->timeout = ev::ev_now () + (r->retry * min_latency * conf.dns_timeout_factor); 1250 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 1251 //printf ("RETRY %x (%d, %f)\n", r->seqno, r->retry, r->timeout - ev_now ());//D
1239 1252
1240 // the following code changes the query section a bit, forcing 1253 // the following code changes the query section a bit, forcing
1241 // the forwarder to generate a new request 1254 // the forwarder to generate a new request
1242 if (r->stdhdr) 1255 if (r->stdhdr)
1243 encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry); 1256 encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry);
… …
1262 } 1275 }
1263 } 1276 }
1264 else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding 1277 else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding
1265 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) 1278 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
1266 { 1279 {
1267 if (last_sent + send_interval <= ev::ev_now ()) 1280 if (last_sent + send_interval <= ev_now ())
1268 { 1281 {
1269 //printf ("sending data request etc.\n"); //D 1282 //printf ("sending data request etc.\n"); //D
1270 if (!snddq.empty () || last_received + 1. > ev::ev_now ()) 1283 if (!snddq.empty () || last_received + 1. > ev_now ())
1271 { 1284 {
1272 poll_interval = send_interval; 1285 poll_interval = send_interval;
1273 NEXT (ev::ev_now () + send_interval); 1286 NEXT (ev_now () + send_interval);
1274 } 1287 }
1275 1288
1276 send = new dns_snd (this); 1289 send = new dns_snd (this);
1277 send->gen_stream_req (sndseq, snddq); 1290 send->gen_stream_req (sndseq, snddq);
1278 send->timeout = ev::ev_now () + min_latency * conf.dns_timeout_factor; 1291 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 1292 //printf ("SEND %x (%f)\n", send->seqno, send->timeout - ev_now (), min_latency, conf.dns_timeout_factor);//D
1280 1293
1281 sndseq = (sndseq + 1) & SEQNO_MASK; 1294 sndseq = (sndseq + 1) & SEQNO_MASK;
1282 } 1295 }
1283 else 1296 else
1284 NEXT (last_sent + send_interval); 1297 NEXT (last_sent + send_interval);
… …
1288 vpn->dns_sndpq.push_back (send); 1301 vpn->dns_sndpq.push_back (send);
1289 } 1302 }
1290 1303
1291 if (send) 1304 if (send)
1292 { 1305 {
1293 last_sent = ev::ev_now (); 1306 last_sent = ev_now ();
1294 sendto (vpn->dnsv4_fd, 1307 sendto (vpn->dnsv4_fd,
1295 send->pkt->at (0), send->pkt->len, 0, 1308 send->pkt->at (0), send->pkt->len, 0,
1296 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); 1309 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
1297 } 1310 }
1298 1311
1299 slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)", 1312 slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)",
1300 poll_interval, send_interval, next - ev::ev_now (), 1313 poll_interval, send_interval, next - ev_now (),
1301 vpn->dns_sndpq.size (), snddq.size (), 1314 vpn->dns_sndpq.size (), snddq.size (),
1302 rcvpq.size ()); 1315 rcvpq.size ());
1303 1316
1304 // TODO: no idea when this happens, but when next < ev::ev_now (), we have a problem 1317 // TODO: no idea when this happens, but when next < ev_now (), we have a problem
1305 // doesn't seem to happen anymore 1318 // doesn't seem to happen anymore
1306 if (next < ev::ev_now () + 0.001) 1319 if (next < ev_now () + 0.001)
1307 next = ev::ev_now () + 0.1; 1320 next = ev_now () + 0.1;
1308 1321
1309 w.start (next - ev::ev_now ()); 1322 w.start (next - ev_now ());
1310} 1323}
1311 1324
1312#endif 1325#endif
1313 1326

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