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Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.24 by pcg, Mon Mar 7 01:31:26 2005 UTC vs.
Revision 1.49 by root, Tue Feb 8 23:11:36 2011 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. 59 Temple Place, Suite 330, Boston, MA 02111-1307 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*/
31
32// TODO: EDNS0 option to increase dns mtu?
33// TODO: re-write dns packet parsing/creation using a safe mem-buffer
34// to ensure no buffer overflows or similar problems.
21 35
22#include "config.h" 36#include "config.h"
23 37
24#if ENABLE_DNS 38#if ENABLE_DNS
25 39
… …
38#include <unistd.h> 52#include <unistd.h>
39#include <fcntl.h> 53#include <fcntl.h>
40 54
41#include <map> 55#include <map>
42 56
57#include <cstdio> /* bug in libgmp: gmp.h relies on cstdio being included */
43#include <gmp.h> 58#include <gmp.h>
44 59
45#include "netcompat.h" 60#include "netcompat.h"
46 61
47#include "vpn.h" 62#include "vpn.h"
48 63
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 64#define MAX_POLL_INTERVAL 5. // how often to poll minimally when the server has no data
51#define ACTIVITY_INTERVAL 5. 65#define ACTIVITY_INTERVAL 5.
52 66
53#define INITIAL_TIMEOUT 0.1 // retry timeouts 67#define INITIAL_TIMEOUT 0.1 // retry timeouts
54#define INITIAL_SYN_TIMEOUT 10. // retry timeout for initial syn 68#define INITIAL_SYN_TIMEOUT 2. // retry timeout for initial syn
55 69
56#define MIN_SEND_INTERVAL 0.01 // wait at least this time between sending requests
57#define MAX_SEND_INTERVAL 0.5 // optimistic? 70#define MAX_SEND_INTERVAL 2. // optimistic?
58 71
59#define MAX_OUTSTANDING 10 // max. outstanding requests
60#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog 72#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 73#define MAX_BACKLOG (64*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE
62 74
63#define MAX_DOMAIN_SIZE 220 // 255 is legal limit, but bind doesn't compress well 75#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 76// 240 leaves about 4 bytes of server reply data
65// every two request bytes less give room for one reply byte 77// every request byte less give room for two reply bytes
66 78
67#define SEQNO_MASK 0x3fff 79#define SEQNO_MASK 0x3fff
68#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) ) 80#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )
69 81
70#define MAX_LBL_SIZE 63 82#define MAX_LBL_SIZE 63
71#define MAX_PKT_SIZE 512 83#define MAX_PKT_SIZE 512
72 84
73#define RR_TYPE_A 1 85#define RR_TYPE_A 1
74#define RR_TYPE_NULL 10 86#define RR_TYPE_NULL 10
75#define RR_TYPE_TXT 16 87#define RR_TYPE_TXT 16
88#define RR_TYPE_AAAA 28
76#define RR_TYPE_ANY 255 89#define RR_TYPE_ANY 255
77 90
78#define RR_CLASS_IN 1 91#define RR_CLASS_IN 1
79 92
80#define CMD_IP_1 207 93#define CMD_IP_1 207
… …
155 enc_len [len] = n; 168 enc_len [len] = n;
156 dec_len [n] = len; 169 dec_len [n] = len;
157 } 170 }
158} 171}
159 172
173unsigned int
160unsigned int basecoder::encode_len (unsigned int len) 174basecoder::encode_len (unsigned int len)
161{ 175{
162 return enc_len [len]; 176 return enc_len [len];
163} 177}
164 178
179unsigned int
165unsigned int basecoder::decode_len (unsigned int len) 180basecoder::decode_len (unsigned int len)
166{ 181{
167 while (len && !dec_len [len]) 182 while (len && !dec_len [len])
168 --len; 183 --len;
169 184
170 return dec_len [len]; 185 return dec_len [len];
171} 186}
172 187
188unsigned int
173unsigned int basecoder::encode (char *dst, u8 *src, unsigned int len) 189basecoder::encode (char *dst, u8 *src, unsigned int len)
174{ 190{
175 if (!len || len > MAX_DEC_LEN) 191 if (!len || len > MAX_DEC_LEN)
176 return 0; 192 return 0;
177 193
178 int elen = encode_len (len); 194 int elen = encode_len (len);
… …
197 *dst++ = cmap.encode [dst_ [i]]; 213 *dst++ = cmap.encode [dst_ [i]];
198 214
199 return elen; 215 return elen;
200} 216}
201 217
218unsigned int
202unsigned int basecoder::decode (u8 *dst, char *src, unsigned int len) 219basecoder::decode (u8 *dst, char *src, unsigned int len)
203{ 220{
204 if (!len || len > MAX_ENC_LEN) 221 if (!len || len > MAX_ENC_LEN)
205 return 0; 222 return 0;
206 223
207 u8 src_ [MAX_ENC_LEN]; 224 u8 src_ [MAX_ENC_LEN];
… …
266 283
267///////////////////////////////////////////////////////////////////////////// 284/////////////////////////////////////////////////////////////////////////////
268 285
269#define HDRSIZE 6 286#define HDRSIZE 6
270 287
288inline void
271inline void encode_header (char *data, int clientid, int seqno, int retry = 0) 289encode_header (char *data, int clientid, int seqno, int retry = 0)
272{ 290{
273 seqno &= SEQNO_MASK; 291 seqno &= SEQNO_MASK;
274 292
275 u8 hdr[3] = { 293 u8 hdr[3] = {
276 clientid, 294 clientid,
… …
281 assert (clientid < 256); 299 assert (clientid < 256);
282 300
283 cdc26.encode (data, hdr, 3); 301 cdc26.encode (data, hdr, 3);
284} 302}
285 303
304inline void
286inline void decode_header (char *data, int &clientid, int &seqno) 305decode_header (char *data, int &clientid, int &seqno)
287{ 306{
288 u8 hdr[3]; 307 u8 hdr[3];
289 308
290 cdc26.decode (hdr, data, HDRSIZE); 309 cdc26.decode (hdr, data, HDRSIZE);
291 310
… …
324byte_stream::~byte_stream () 343byte_stream::~byte_stream ()
325{ 344{
326 delete data; 345 delete data;
327} 346}
328 347
348void
329void byte_stream::remove (int count) 349byte_stream::remove (int count)
330{ 350{
331 if (count > fill) 351 if (count > fill)
332 assert (count <= fill); 352 assert (count <= fill);
333 353
334 memmove (data, data + count, fill -= count); 354 memmove (data, data + count, fill -= count);
335} 355}
336 356
357bool
337bool byte_stream::put (u8 *data, unsigned int datalen) 358byte_stream::put (u8 *data, unsigned int datalen)
338{ 359{
339 if (maxsize - fill < datalen) 360 if (maxsize - fill < datalen)
340 return false; 361 return false;
341 362
342 memcpy (this->data + fill, data, datalen); fill += datalen; 363 memcpy (this->data + fill, data, datalen); fill += datalen;
343 364
344 return true; 365 return true;
345} 366}
346 367
368bool
347bool byte_stream::put (vpn_packet *pkt) 369byte_stream::put (vpn_packet *pkt)
348{ 370{
349 if (maxsize - fill < pkt->len + 2) 371 if (maxsize - fill < pkt->len + 2)
350 return false; 372 return false;
351 373
352 data [fill++] = pkt->len >> 8; 374 data [fill++] = pkt->len >> 8;
… …
423 u16 max_size; 445 u16 max_size;
424 u8 seq_cdc; 446 u8 seq_cdc;
425 u8 req_cdc; 447 u8 req_cdc;
426 448
427 u8 rep_cdc; 449 u8 rep_cdc;
450 u8 delay; // time in 0.01s units that the server may delay replying packets
428 u8 r2, r3, r4; 451 u8 r3, r4;
429 452
430 u8 r5, r6, r7, r8; 453 u8 r5, r6, r7, r8;
431 454
432 void reset (int clientid); 455 void reset (int clientid);
433 bool valid (); 456 bool valid ();
434}; 457};
435 458
436int dns_cfg::next_uid; 459int dns_cfg::next_uid;
437 460
461void
438void dns_cfg::reset (int clientid) 462dns_cfg::reset (int clientid)
439{ 463{
440 id1 = 'G'; 464 id1 = 'G';
441 id2 = 'V'; 465 id2 = 'V';
442 id3 = 'P'; 466 id3 = 'P';
443 id4 = 'E'; 467 id4 = 'E';
… …
448 flags = 0; 472 flags = 0;
449 def_ttl = 0; 473 def_ttl = 0;
450 seq_cdc = 26; 474 seq_cdc = 26;
451 req_cdc = 62; 475 req_cdc = 62;
452 rep_cdc = 0; 476 rep_cdc = 0;
453 max_size = ntohs (MAX_PKT_SIZE); 477 max_size = htons (MAX_PKT_SIZE);
454 client = ntohs (clientid); 478 client = htons (clientid);
455 uid = next_uid++; 479 uid = next_uid++;
480 delay = 0;
456 481
457 r2 = r3 = r4 = 0; 482 r3 = r4 = 0;
458 r4 = r5 = r6 = r7 = 0; 483 r4 = r5 = r6 = r7 = 0;
459} 484}
460 485
486bool
461bool dns_cfg::valid () 487dns_cfg::valid ()
462{ 488{
489 // although the protocol itself allows for some configurability,
490 // only the following encoding/decoding settings are implemented.
463 return id1 == 'G' 491 return id1 == 'G'
464 && id2 == 'V' 492 && id2 == 'V'
465 && id3 == 'P' 493 && id3 == 'P'
466 && id4 == 'E' 494 && id4 == 'E'
467 && seq_cdc == 26 495 && seq_cdc == 26
468 && req_cdc == 62 496 && req_cdc == 62
469 && rep_cdc == 0 497 && rep_cdc == 0
470 && version == 1 498 && version == 1;
471 && max_size == ntohs (MAX_PKT_SIZE);
472} 499}
473 500
474struct dns_packet : net_packet 501struct dns_packet : net_packet
475{ 502{
476 u16 id; 503 u16 id;
… …
480 u8 data [MAXSIZE - 6 * 2]; 507 u8 data [MAXSIZE - 6 * 2];
481 508
482 int decode_label (char *data, int size, int &offs); 509 int decode_label (char *data, int size, int &offs);
483}; 510};
484 511
512int
485int dns_packet::decode_label (char *data, int size, int &offs) 513dns_packet::decode_label (char *data, int size, int &offs)
486{ 514{
487 char *orig = data; 515 char *orig = data;
488 516
489 memset (data, 0, size); 517 memset (data, 0, size);
490 518
… …
516 return data - orig; 544 return data - orig;
517} 545}
518 546
519///////////////////////////////////////////////////////////////////////////// 547/////////////////////////////////////////////////////////////////////////////
520 548
549static
550u16 next_id ()
551{
521static u16 dns_id = 0; // TODO: should be per-vpn 552 static u16 dns_id = 0; // TODO: should be per-vpn
522 553
523static u16 next_id ()
524{
525 if (!dns_id) 554 if (!dns_id)
526 dns_id = time (0); 555 dns_id = time (0);
527 556
528 // the simplest lsfr with periodicity 65535 i could find 557 // the simplest lsfr with periodicity 65535 i could find
529 dns_id = (dns_id << 1) 558 dns_id = (dns_id << 1)
… …
547 576
548 bool established; 577 bool established;
549 578
550 tstamp last_received; 579 tstamp last_received;
551 tstamp last_sent; 580 tstamp last_sent;
552 double last_latency; 581 double min_latency;
553 double poll_interval, send_interval; 582 double poll_interval, send_interval;
554 583
555 vector<dns_rcv *> rcvpq; 584 vector<dns_rcv *> rcvpq;
556 585
557 byte_stream rcvdq; int rcvseq; 586 byte_stream rcvdq; int rcvseq; int repseq;
558 byte_stream snddq; int sndseq; 587 byte_stream snddq; int sndseq;
559 588
560 void time_cb (time_watcher &w); time_watcher tw; 589 inline void time_cb (ev::timer &w, int revents); ev::timer tw;
561 void receive_rep (dns_rcv *r); 590 void receive_rep (dns_rcv *r);
562 591
563 dns_connection (connection *c); 592 dns_connection (connection *c);
564 ~dns_connection (); 593 ~dns_connection ();
565}; 594};
… …
584: dns (dns) 613: dns (dns)
585{ 614{
586 timeout = 0; 615 timeout = 0;
587 retry = 0; 616 retry = 0;
588 seqno = 0; 617 seqno = 0;
589 sent = NOW; 618 sent = ev_now ();
590 stdhdr = false; 619 stdhdr = false;
591 620
592 pkt = new dns_packet; 621 pkt = new dns_packet;
593 622
594 pkt->id = next_id (); 623 pkt->id = next_id ();
… …
597dns_snd::~dns_snd () 626dns_snd::~dns_snd ()
598{ 627{
599 delete pkt; 628 delete pkt;
600} 629}
601 630
631static void
602static void append_domain (dns_packet &pkt, int &offs, const char *domain) 632append_domain (dns_packet &pkt, int &offs, const char *domain)
603{ 633{
604 // add tunnel domain 634 // add tunnel domain
605 for (;;) 635 for (;;)
606 { 636 {
607 const char *end = strchr (domain, '.'); 637 const char *end = strchr (domain, '.');
… …
620 650
621 domain = end + 1; 651 domain = end + 1;
622 } 652 }
623} 653}
624 654
655void
625void dns_snd::gen_stream_req (int seqno, byte_stream &stream) 656dns_snd::gen_stream_req (int seqno, byte_stream &stream)
626{ 657{
627 stdhdr = true; 658 stdhdr = true;
628 this->seqno = seqno; 659 this->seqno = seqno;
629 660
630 timeout = NOW + INITIAL_TIMEOUT; 661 timeout = ev_now () + INITIAL_TIMEOUT;
631 662
632 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 663 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
633 pkt->qdcount = htons (1); 664 pkt->qdcount = htons (1);
634 665
635 int offs = 6*2; 666 int offs = 6*2;
… …
668 (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN; 699 (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN;
669 700
670 pkt->len = offs; 701 pkt->len = offs;
671} 702}
672 703
704void
673void dns_snd::gen_syn_req () 705dns_snd::gen_syn_req ()
674{ 706{
675 timeout = NOW + INITIAL_SYN_TIMEOUT; 707 timeout = ev_now () + INITIAL_SYN_TIMEOUT;
676 708
677 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 709 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
678 pkt->qdcount = htons (1); 710 pkt->qdcount = htons (1);
679 711
680 int offs = 6 * 2; 712 int offs = 6 * 2;
… …
719///////////////////////////////////////////////////////////////////////////// 751/////////////////////////////////////////////////////////////////////////////
720 752
721dns_connection::dns_connection (connection *c) 753dns_connection::dns_connection (connection *c)
722: c (c) 754: c (c)
723, rcvdq (MAX_BACKLOG * 2) 755, rcvdq (MAX_BACKLOG * 2)
724, snddq (MAX_BACKLOG * 2) 756, snddq (MAX_BACKLOG)
725, tw (this, &dns_connection::time_cb)
726{ 757{
758 tw.set<dns_connection, &dns_connection::time_cb> (this);
759
727 vpn = c->vpn; 760 vpn = c->vpn;
728 761
729 established = false; 762 established = false;
730 763
731 rcvseq = sndseq = 0; 764 rcvseq = repseq = sndseq = 0;
732 765
733 last_sent = last_received = 0; 766 last_sent = last_received = 0;
734 poll_interval = MIN_POLL_INTERVAL; 767 poll_interval = 0.5; // starting here
735 send_interval = 0.5; // starting rate 768 send_interval = 0.5; // starting rate
736 last_latency = INITIAL_TIMEOUT; 769 min_latency = INITIAL_TIMEOUT;
737} 770}
738 771
739dns_connection::~dns_connection () 772dns_connection::~dns_connection ()
740{ 773{
741 for (vector<dns_rcv *>::iterator i = rcvpq.begin (); 774 for (vector<dns_rcv *>::iterator i = rcvpq.begin ();
742 i != rcvpq.end (); 775 i != rcvpq.end ();
743 ++i) 776 ++i)
744 delete *i; 777 delete *i;
745} 778}
746 779
780void
747void dns_connection::receive_rep (dns_rcv *r) 781dns_connection::receive_rep (dns_rcv *r)
748{ 782{
749 if (r->datalen) 783 if (r->datalen)
750 { 784 {
751 last_received = NOW; 785 last_received = ev_now ();
752 tw.trigger (); 786 tw ();
753 787
754 poll_interval = send_interval; 788 poll_interval = send_interval;
755 } 789 }
756 else 790 else
757 { 791 {
758 poll_interval *= 1.5; 792 poll_interval *= 1.5;
793
759 if (poll_interval > MAX_POLL_INTERVAL) 794 if (poll_interval > MAX_POLL_INTERVAL)
760 poll_interval = MAX_POLL_INTERVAL; 795 poll_interval = MAX_POLL_INTERVAL;
761 } 796 }
762 797
763 rcvpq.push_back (r); 798 rcvpq.push_back (r);
… …
766 801
767 // find next packet 802 // find next packet
768 for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); ) 803 for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); )
769 if (SEQNO_EQ (rcvseq, (*i)->seqno)) 804 if (SEQNO_EQ (rcvseq, (*i)->seqno))
770 { 805 {
806 //printf ("seqno eq %x %x\n", rcvseq, (*i)->seqno);//D
771 // enter the packet into our input stream 807 // enter the packet into our input stream
772 r = *i; 808 r = *i;
773 809
774 // remove the oldest packet, look forward, as it's oldest first 810 // remove the oldest packet, look forward, as it's oldest first
775 for (vector<dns_rcv *>::iterator j = rcvpq.begin (); j != rcvpq.end (); ++j) 811 for (vector<dns_rcv *>::iterator j = rcvpq.begin (); j != rcvpq.end (); ++j)
776 if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW)) 812 if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW))
777 { 813 {
814 //printf ("seqno RR %x %x\n", (*j)->seqno, rcvseq - MAX_WINDOW);//D
778 delete *j; 815 delete *j;
779 rcvpq.erase (j); 816 rcvpq.erase (j);
780 break; 817 break;
781 } 818 }
782 819
… …
789 } 826 }
790 827
791 while (vpn_packet *pkt = rcvdq.get ()) 828 while (vpn_packet *pkt = rcvdq.get ())
792 { 829 {
793 sockinfo si; 830 sockinfo si;
794 si.host = 0x01010101; si.port = htons (c->conf->id); si.prot = PROT_DNSv4; 831 si.host = htonl (c->conf->id); si.port = 0; si.prot = PROT_DNSv4;
795 832
796 vpn->recv_vpn_packet (pkt, si); 833 vpn->recv_vpn_packet (pkt, si);
797 834
798 delete pkt; 835 delete pkt;
799 } 836 }
… …
853 if (0 < client && client <= conns.size ()) 890 if (0 < client && client <= conns.size ())
854 { 891 {
855 connection *c = conns [client - 1]; 892 connection *c = conns [client - 1];
856 dns_connection *dns = c->dns; 893 dns_connection *dns = c->dns;
857 dns_rcv *rcv; 894 dns_rcv *rcv;
858 bool in_seq;
859 895
860 if (dns) 896 if (dns)
861 { 897 {
862 for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); ) 898 for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); )
863 if (SEQNO_EQ ((*i)->seqno, seqno)) 899 if (SEQNO_EQ ((*i)->seqno, seqno))
… …
874 memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len); 910 memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len);
875 911
876 goto duplicate_request; 912 goto duplicate_request;
877 } 913 }
878 914
879 in_seq = dns->rcvseq == seqno;
880
881 // new packet, queue 915 // new packet, queue
882 rcv = new dns_rcv (seqno, data, datalen); 916 rcv = new dns_rcv (seqno, data, datalen);
883 dns->receive_rep (rcv); 917 dns->receive_rep (rcv);
884 } 918 }
885 919
… …
892 pkt [offs++] = 0; pkt [offs++] = 0; 926 pkt [offs++] = 0; pkt [offs++] = 0;
893 pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL 927 pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL
894 928
895 int rdlen_offs = offs += 2; 929 int rdlen_offs = offs += 2;
896 930
897 int dlen = (dns ? ntohs (dns->cfg.max_size) : MAX_PKT_SIZE) - offs;
898 // bind doesn't compress well, so reduce further by one label length
899 dlen -= qlen;
900
901 if (dns) 931 if (dns)
902 { 932 {
933 int dlen = ntohs (dns->cfg.max_size) - offs;
934
935 // bind doesn't compress well, so reduce further by one label length
936 dlen -= qlen;
937
903 // only put data into in-order sequence packets, if 938 // only put data into in-order sequence packets, if
904 // we receive out-of-order packets we generate empty 939 // we receive out-of-order packets we generate empty
905 // replies 940 // replies
906 while (dlen > 1 && !dns->snddq.empty () && in_seq) 941 //printf ("%d - %d & %x (=%d) < %d\n", seqno, dns->repseq, SEQNO_MASK, (seqno - dns->repseq) & SEQNO_MASK, MAX_WINDOW);//D
942 if (((seqno - dns->repseq) & SEQNO_MASK) <= MAX_WINDOW)
907 { 943 {
944 dns->repseq = seqno;
945
946 while (dlen > 1 && !dns->snddq.empty ())
947 {
908 int txtlen = dlen <= 255 ? dlen - 1 : 255; 948 int txtlen = dlen <= 255 ? dlen - 1 : 255;
909 949
910 if (txtlen > dns->snddq.size ()) 950 if (txtlen > dns->snddq.size ())
911 txtlen = dns->snddq.size (); 951 txtlen = dns->snddq.size ();
912 952
913 pkt[offs++] = txtlen; 953 pkt[offs++] = txtlen;
914 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen); 954 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
915 offs += txtlen; 955 offs += txtlen;
916 dns->snddq.remove (txtlen); 956 dns->snddq.remove (txtlen);
917 957
918 dlen -= txtlen + 1; 958 dlen -= txtlen + 1;
959 }
919 } 960 }
920 961
921 // avoid empty TXT rdata 962 // avoid completely empty TXT rdata
922 if (offs == rdlen_offs) 963 if (offs == rdlen_offs)
923 pkt[offs++] = 0; 964 pkt[offs++] = 0;
924 965
925 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ()); 966 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
926 } 967 }
… …
1006 { 1047 {
1007 dns_connection *dns = (*i)->dns; 1048 dns_connection *dns = (*i)->dns;
1008 connection *c = dns->c; 1049 connection *c = dns->c;
1009 int seqno = (*i)->seqno; 1050 int seqno = (*i)->seqno;
1010 u8 data[MAXSIZE], *datap = data; 1051 u8 data[MAXSIZE], *datap = data;
1052 //printf ("rcv pkt %x\n", seqno);//D
1011 1053
1012 if ((*i)->retry) 1054 if ((*i)->retry)
1013 { 1055 {
1014 dns->send_interval *= 1.01; 1056 dns->send_interval *= 1.01;
1015 if (dns->send_interval > MAX_SEND_INTERVAL) 1057 if (dns->send_interval > MAX_SEND_INTERVAL)
1016 dns->send_interval = MAX_SEND_INTERVAL; 1058 dns->send_interval = MAX_SEND_INTERVAL;
1017 } 1059 }
1018 else 1060 else
1019 { 1061 {
1020#if 1 1062#if 0
1021 dns->send_interval *= 0.999; 1063 dns->send_interval *= 0.999;
1022#endif 1064#endif
1023 if (dns->send_interval < MIN_SEND_INTERVAL)
1024 dns->send_interval = MIN_SEND_INTERVAL;
1025
1026 // the latency surely puts an upper bound on 1065 // the latency surely puts an upper bound on
1027 // the minimum send interval 1066 // the minimum send interval
1028 double latency = NOW - (*i)->sent; 1067 double latency = ev_now () - (*i)->sent;
1068
1069 if (latency < dns->min_latency)
1029 dns->last_latency = latency; 1070 dns->min_latency = latency;
1030 1071
1031 if (dns->send_interval > latency) 1072 if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor)
1073 dns->send_interval = dns->min_latency * conf.dns_overlap_factor;
1074
1075 if (dns->send_interval < conf.dns_send_interval)
1032 dns->send_interval = latency; 1076 dns->send_interval = conf.dns_send_interval;
1033 } 1077 }
1034 1078
1035 delete *i; 1079 delete *i;
1036 dns_sndpq.erase (i); 1080 dns_sndpq.erase (i);
1037 1081
… …
1142 break; 1186 break;
1143 } 1187 }
1144} 1188}
1145 1189
1146void 1190void
1147vpn::dnsv4_ev (io_watcher &w, short revents) 1191vpn::dnsv4_ev (ev::io &w, int revents)
1148{ 1192{
1149 if (revents & EVENT_READ) 1193 if (revents & EV_READ)
1150 { 1194 {
1151 dns_packet *pkt = new dns_packet; 1195 dns_packet *pkt = new dns_packet;
1152 struct sockaddr_in sa; 1196 struct sockaddr_in sa;
1153 socklen_t sa_len = sizeof (sa); 1197 socklen_t sa_len = sizeof (sa);
1154 1198
… …
1170} 1214}
1171 1215
1172bool 1216bool
1173vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) 1217vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
1174{ 1218{
1175 int client = ntohs (si.port); 1219 int client = ntohl (si.host);
1176 1220
1177 assert (0 < client && client <= conns.size ()); 1221 assert (0 < client && client <= conns.size ());
1178 1222
1179 connection *c = conns [client - 1]; 1223 connection *c = conns [client - 1];
1180 1224
1181 if (!c->dns) 1225 if (!c->dns)
1182 c->dns = new dns_connection (c); 1226 c->dns = new dns_connection (c);
1183 1227
1184 if (!c->dns->snddq.put (pkt)) 1228 if (c->dns->snddq.put (pkt))
1185 return false;
1186
1187 c->dns->tw.trigger (); 1229 c->dns->tw ();
1188 1230
1231 // always return true even if the buffer overflows
1189 return true; 1232 return true;
1190} 1233}
1191 1234
1192void 1235void
1193connection::dnsv4_reset_connection () 1236connection::dnsv4_reset_connection ()
… …
1196} 1239}
1197 1240
1198#define NEXT(w) do { if (next > (w)) next = w; } while (0) 1241#define NEXT(w) do { if (next > (w)) next = w; } while (0)
1199 1242
1200void 1243void
1201dns_connection::time_cb (time_watcher &w) 1244dns_connection::time_cb (ev::timer &w, int revents)
1202{ 1245{
1203 // servers have to be polled 1246 // servers have to be polled
1204 if (THISNODE->dns_port) 1247 if (THISNODE->dns_port)
1205 return; 1248 return;
1206 1249
1207 // check for timeouts and (re)transmit 1250 // check for timeouts and (re)transmit
1208 tstamp next = NOW + poll_interval; 1251 tstamp next = ev::now () + poll_interval;
1209 dns_snd *send = 0; 1252 dns_snd *send = 0;
1210 1253
1211 for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin (); 1254 for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin ();
1212 i != vpn->dns_sndpq.end (); 1255 i != vpn->dns_sndpq.end ();
1213 ++i) 1256 ++i)
1214 { 1257 {
1215 dns_snd *r = *i; 1258 dns_snd *r = *i;
1216 1259
1217 if (r->timeout <= NOW) 1260 if (r->timeout <= ev_now ())
1218 { 1261 {
1219 if (!send) 1262 if (!send)
1220 { 1263 {
1221 send = r; 1264 send = r;
1222 1265
1223 r->retry++; 1266 r->retry++;
1224 r->timeout = NOW + (r->retry * last_latency * 8.); 1267 r->timeout = ev_now () + (r->retry * min_latency * conf.dns_timeout_factor);
1268 //printf ("RETRY %x (%d, %f)\n", r->seqno, r->retry, r->timeout - ev_now ());//D
1225 1269
1226 // the following code changes the query section a bit, forcing 1270 // the following code changes the query section a bit, forcing
1227 // the forwarder to generate a new request 1271 // the forwarder to generate a new request
1228 if (r->stdhdr) 1272 if (r->stdhdr)
1229 {
1230 //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);
1231 //encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry); 1273 encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry);
1232 }
1233 } 1274 }
1234 } 1275 }
1235 else 1276 else
1236 NEXT (r->timeout); 1277 NEXT (r->timeout);
1237 } 1278 }
1238 1279
1239 if (last_sent + send_interval <= NOW)
1240 {
1241 if (!send) 1280 if (!send)
1281 {
1282 // generate a new packet, if wise
1283
1284 if (!established)
1242 { 1285 {
1243 // generate a new packet, if wise 1286 if (vpn->dns_sndpq.empty ())
1244
1245 if (!established)
1246 { 1287 {
1247 if (vpn->dns_sndpq.empty ())
1248 {
1249 send = new dns_snd (this); 1288 send = new dns_snd (this);
1250 1289
1251 cfg.reset (THISNODE->id); 1290 cfg.reset (THISNODE->id);
1252 send->gen_syn_req (); 1291 send->gen_syn_req ();
1253 }
1254 } 1292 }
1255 else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING 1293 }
1294 else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding
1256 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) 1295 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
1296 {
1297 if (last_sent + send_interval <= ev_now ())
1257 { 1298 {
1258 //printf ("sending data request etc.\n"); //D 1299 //printf ("sending data request etc.\n"); //D
1259 if (!snddq.empty ()) 1300 if (!snddq.empty () || last_received + 1. > ev_now ())
1260 { 1301 {
1261 poll_interval = send_interval; 1302 poll_interval = send_interval;
1262 NEXT (NOW + send_interval); 1303 NEXT (ev_now () + send_interval);
1263 } 1304 }
1264 1305
1265 send = new dns_snd (this); 1306 send = new dns_snd (this);
1266 send->gen_stream_req (sndseq, snddq); 1307 send->gen_stream_req (sndseq, snddq);
1267 send->timeout = NOW + last_latency * 8.; 1308 send->timeout = ev_now () + min_latency * conf.dns_timeout_factor;
1309 //printf ("SEND %x (%f)\n", send->seqno, send->timeout - ev_now (), min_latency, conf.dns_timeout_factor);//D
1268 1310
1269 sndseq = (sndseq + 1) & SEQNO_MASK; 1311 sndseq = (sndseq + 1) & SEQNO_MASK;
1270 } 1312 }
1271 1313 else
1272 if (send) 1314 NEXT (last_sent + send_interval);
1273 vpn->dns_sndpq.push_back (send);
1274 } 1315 }
1275 1316
1276 if (send) 1317 if (send)
1277 { 1318 vpn->dns_sndpq.push_back (send);
1278 last_sent = NOW; 1319 }
1320
1321 if (send)
1322 {
1323 last_sent = ev_now ();
1279 sendto (vpn->dnsv4_fd, 1324 sendto (vpn->dnsv4_fd,
1280 send->pkt->at (0), send->pkt->len, 0, 1325 send->pkt->at (0), send->pkt->len, 0,
1281 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); 1326 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
1282 }
1283 } 1327 }
1284 else
1285 NEXT (last_sent + send_interval);
1286 1328
1287 slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d)", 1329 slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)",
1288 poll_interval, send_interval, next - NOW, 1330 poll_interval, send_interval, next - ev_now (),
1289 vpn->dns_sndpq.size (), snddq.size ()); 1331 vpn->dns_sndpq.size (), snddq.size (),
1332 rcvpq.size ());
1290 1333
1291 // TODO: no idea when this happens, but when next < NOW, we have a problem 1334 // TODO: no idea when this happens, but when next < ev_now (), we have a problem
1335 // doesn't seem to happen anymore
1292 if (next < NOW + 0.0001) 1336 if (next < ev_now () + 0.001)
1293 next = NOW + 0.1; 1337 next = ev_now () + 0.1;
1294 1338
1295 w.start (next); 1339 w.start (next - ev_now ());
1296} 1340}
1297 1341
1298#endif 1342#endif
1299 1343

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