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Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.26 by pcg, Tue Mar 8 17:25:27 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 LATENCY_FACTOR 0.5 // RTT * LATENCY_FACTOR == sending rate
60#define MAX_OUTSTANDING 20 // max. outstanding requests
61#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog 72#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 73#define MAX_BACKLOG (64*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE
63 74
64#define MAX_DOMAIN_SIZE 200 // 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
65// 240 leaves about 4 bytes of server reply data 76// 240 leaves about 4 bytes of server reply data
66// every two request bytes less give room for one reply byte 77// every request byte less give room for two reply bytes
67 78
68#define SEQNO_MASK 0x3fff 79#define SEQNO_MASK 0x3fff
69#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) ) 80#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )
70 81
71#define MAX_LBL_SIZE 63 82#define MAX_LBL_SIZE 63
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
… …
156 enc_len [len] = n; 168 enc_len [len] = n;
157 dec_len [n] = len; 169 dec_len [n] = len;
158 } 170 }
159} 171}
160 172
173unsigned int
161unsigned int basecoder::encode_len (unsigned int len) 174basecoder::encode_len (unsigned int len)
162{ 175{
163 return enc_len [len]; 176 return enc_len [len];
164} 177}
165 178
179unsigned int
166unsigned int basecoder::decode_len (unsigned int len) 180basecoder::decode_len (unsigned int len)
167{ 181{
168 while (len && !dec_len [len]) 182 while (len && !dec_len [len])
169 --len; 183 --len;
170 184
171 return dec_len [len]; 185 return dec_len [len];
172} 186}
173 187
188unsigned int
174unsigned int basecoder::encode (char *dst, u8 *src, unsigned int len) 189basecoder::encode (char *dst, u8 *src, unsigned int len)
175{ 190{
176 if (!len || len > MAX_DEC_LEN) 191 if (!len || len > MAX_DEC_LEN)
177 return 0; 192 return 0;
178 193
179 int elen = encode_len (len); 194 int elen = encode_len (len);
… …
198 *dst++ = cmap.encode [dst_ [i]]; 213 *dst++ = cmap.encode [dst_ [i]];
199 214
200 return elen; 215 return elen;
201} 216}
202 217
218unsigned int
203unsigned int basecoder::decode (u8 *dst, char *src, unsigned int len) 219basecoder::decode (u8 *dst, char *src, unsigned int len)
204{ 220{
205 if (!len || len > MAX_ENC_LEN) 221 if (!len || len > MAX_ENC_LEN)
206 return 0; 222 return 0;
207 223
208 u8 src_ [MAX_ENC_LEN]; 224 u8 src_ [MAX_ENC_LEN];
… …
267 283
268///////////////////////////////////////////////////////////////////////////// 284/////////////////////////////////////////////////////////////////////////////
269 285
270#define HDRSIZE 6 286#define HDRSIZE 6
271 287
288inline void
272inline void encode_header (char *data, int clientid, int seqno, int retry = 0) 289encode_header (char *data, int clientid, int seqno, int retry = 0)
273{ 290{
274 seqno &= SEQNO_MASK; 291 seqno &= SEQNO_MASK;
275 292
276 u8 hdr[3] = { 293 u8 hdr[3] = {
277 clientid, 294 clientid,
… …
282 assert (clientid < 256); 299 assert (clientid < 256);
283 300
284 cdc26.encode (data, hdr, 3); 301 cdc26.encode (data, hdr, 3);
285} 302}
286 303
304inline void
287inline void decode_header (char *data, int &clientid, int &seqno) 305decode_header (char *data, int &clientid, int &seqno)
288{ 306{
289 u8 hdr[3]; 307 u8 hdr[3];
290 308
291 cdc26.decode (hdr, data, HDRSIZE); 309 cdc26.decode (hdr, data, HDRSIZE);
292 310
… …
325byte_stream::~byte_stream () 343byte_stream::~byte_stream ()
326{ 344{
327 delete data; 345 delete data;
328} 346}
329 347
348void
330void byte_stream::remove (int count) 349byte_stream::remove (int count)
331{ 350{
332 if (count > fill) 351 if (count > fill)
333 assert (count <= fill); 352 assert (count <= fill);
334 353
335 memmove (data, data + count, fill -= count); 354 memmove (data, data + count, fill -= count);
336} 355}
337 356
357bool
338bool byte_stream::put (u8 *data, unsigned int datalen) 358byte_stream::put (u8 *data, unsigned int datalen)
339{ 359{
340 if (maxsize - fill < datalen) 360 if (maxsize - fill < datalen)
341 return false; 361 return false;
342 362
343 memcpy (this->data + fill, data, datalen); fill += datalen; 363 memcpy (this->data + fill, data, datalen); fill += datalen;
344 364
345 return true; 365 return true;
346} 366}
347 367
368bool
348bool byte_stream::put (vpn_packet *pkt) 369byte_stream::put (vpn_packet *pkt)
349{ 370{
350 if (maxsize - fill < pkt->len + 2) 371 if (maxsize - fill < pkt->len + 2)
351 return false; 372 return false;
352 373
353 data [fill++] = pkt->len >> 8; 374 data [fill++] = pkt->len >> 8;
… …
424 u16 max_size; 445 u16 max_size;
425 u8 seq_cdc; 446 u8 seq_cdc;
426 u8 req_cdc; 447 u8 req_cdc;
427 448
428 u8 rep_cdc; 449 u8 rep_cdc;
450 u8 delay; // time in 0.01s units that the server may delay replying packets
429 u8 r2, r3, r4; 451 u8 r3, r4;
430 452
431 u8 r5, r6, r7, r8; 453 u8 r5, r6, r7, r8;
432 454
433 void reset (int clientid); 455 void reset (int clientid);
434 bool valid (); 456 bool valid ();
435}; 457};
436 458
437int dns_cfg::next_uid; 459int dns_cfg::next_uid;
438 460
461void
439void dns_cfg::reset (int clientid) 462dns_cfg::reset (int clientid)
440{ 463{
441 id1 = 'G'; 464 id1 = 'G';
442 id2 = 'V'; 465 id2 = 'V';
443 id3 = 'P'; 466 id3 = 'P';
444 id4 = 'E'; 467 id4 = 'E';
… …
449 flags = 0; 472 flags = 0;
450 def_ttl = 0; 473 def_ttl = 0;
451 seq_cdc = 26; 474 seq_cdc = 26;
452 req_cdc = 62; 475 req_cdc = 62;
453 rep_cdc = 0; 476 rep_cdc = 0;
454 max_size = ntohs (MAX_PKT_SIZE); 477 max_size = htons (MAX_PKT_SIZE);
455 client = ntohs (clientid); 478 client = htons (clientid);
456 uid = next_uid++; 479 uid = next_uid++;
480 delay = 0;
457 481
458 r2 = r3 = r4 = 0; 482 r3 = r4 = 0;
459 r4 = r5 = r6 = r7 = 0; 483 r4 = r5 = r6 = r7 = 0;
460} 484}
461 485
486bool
462bool dns_cfg::valid () 487dns_cfg::valid ()
463{ 488{
489 // although the protocol itself allows for some configurability,
490 // only the following encoding/decoding settings are implemented.
464 return id1 == 'G' 491 return id1 == 'G'
465 && id2 == 'V' 492 && id2 == 'V'
466 && id3 == 'P' 493 && id3 == 'P'
467 && id4 == 'E' 494 && id4 == 'E'
468 && seq_cdc == 26 495 && seq_cdc == 26
469 && req_cdc == 62 496 && req_cdc == 62
470 && rep_cdc == 0 497 && rep_cdc == 0
471 && version == 1 498 && version == 1;
472 && max_size == ntohs (MAX_PKT_SIZE);
473} 499}
474 500
475struct dns_packet : net_packet 501struct dns_packet : net_packet
476{ 502{
477 u16 id; 503 u16 id;
… …
481 u8 data [MAXSIZE - 6 * 2]; 507 u8 data [MAXSIZE - 6 * 2];
482 508
483 int decode_label (char *data, int size, int &offs); 509 int decode_label (char *data, int size, int &offs);
484}; 510};
485 511
512int
486int dns_packet::decode_label (char *data, int size, int &offs) 513dns_packet::decode_label (char *data, int size, int &offs)
487{ 514{
488 char *orig = data; 515 char *orig = data;
489 516
490 memset (data, 0, size); 517 memset (data, 0, size);
491 518
… …
517 return data - orig; 544 return data - orig;
518} 545}
519 546
520///////////////////////////////////////////////////////////////////////////// 547/////////////////////////////////////////////////////////////////////////////
521 548
549static
550u16 next_id ()
551{
522static u16 dns_id = 0; // TODO: should be per-vpn 552 static u16 dns_id = 0; // TODO: should be per-vpn
523 553
524static u16 next_id ()
525{
526 if (!dns_id) 554 if (!dns_id)
527 dns_id = time (0); 555 dns_id = time (0);
528 556
529 // the simplest lsfr with periodicity 65535 i could find 557 // the simplest lsfr with periodicity 65535 i could find
530 dns_id = (dns_id << 1) 558 dns_id = (dns_id << 1)
… …
553 double min_latency; 581 double min_latency;
554 double poll_interval, send_interval; 582 double poll_interval, send_interval;
555 583
556 vector<dns_rcv *> rcvpq; 584 vector<dns_rcv *> rcvpq;
557 585
558 byte_stream rcvdq; int rcvseq; 586 byte_stream rcvdq; int rcvseq; int repseq;
559 byte_stream snddq; int sndseq; 587 byte_stream snddq; int sndseq;
560 588
561 void time_cb (time_watcher &w); time_watcher tw; 589 inline void time_cb (ev::timer &w, int revents); ev::timer tw;
562 void receive_rep (dns_rcv *r); 590 void receive_rep (dns_rcv *r);
563 591
564 dns_connection (connection *c); 592 dns_connection (connection *c);
565 ~dns_connection (); 593 ~dns_connection ();
566}; 594};
… …
585: dns (dns) 613: dns (dns)
586{ 614{
587 timeout = 0; 615 timeout = 0;
588 retry = 0; 616 retry = 0;
589 seqno = 0; 617 seqno = 0;
590 sent = NOW; 618 sent = ev_now ();
591 stdhdr = false; 619 stdhdr = false;
592 620
593 pkt = new dns_packet; 621 pkt = new dns_packet;
594 622
595 pkt->id = next_id (); 623 pkt->id = next_id ();
… …
598dns_snd::~dns_snd () 626dns_snd::~dns_snd ()
599{ 627{
600 delete pkt; 628 delete pkt;
601} 629}
602 630
631static void
603static void append_domain (dns_packet &pkt, int &offs, const char *domain) 632append_domain (dns_packet &pkt, int &offs, const char *domain)
604{ 633{
605 // add tunnel domain 634 // add tunnel domain
606 for (;;) 635 for (;;)
607 { 636 {
608 const char *end = strchr (domain, '.'); 637 const char *end = strchr (domain, '.');
… …
621 650
622 domain = end + 1; 651 domain = end + 1;
623 } 652 }
624} 653}
625 654
655void
626void dns_snd::gen_stream_req (int seqno, byte_stream &stream) 656dns_snd::gen_stream_req (int seqno, byte_stream &stream)
627{ 657{
628 stdhdr = true; 658 stdhdr = true;
629 this->seqno = seqno; 659 this->seqno = seqno;
630 660
631 timeout = NOW + INITIAL_TIMEOUT; 661 timeout = ev_now () + INITIAL_TIMEOUT;
632 662
633 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 663 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
634 pkt->qdcount = htons (1); 664 pkt->qdcount = htons (1);
635 665
636 int offs = 6*2; 666 int offs = 6*2;
… …
669 (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN; 699 (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN;
670 700
671 pkt->len = offs; 701 pkt->len = offs;
672} 702}
673 703
704void
674void dns_snd::gen_syn_req () 705dns_snd::gen_syn_req ()
675{ 706{
676 timeout = NOW + INITIAL_SYN_TIMEOUT; 707 timeout = ev_now () + INITIAL_SYN_TIMEOUT;
677 708
678 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 709 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
679 pkt->qdcount = htons (1); 710 pkt->qdcount = htons (1);
680 711
681 int offs = 6 * 2; 712 int offs = 6 * 2;
… …
720///////////////////////////////////////////////////////////////////////////// 751/////////////////////////////////////////////////////////////////////////////
721 752
722dns_connection::dns_connection (connection *c) 753dns_connection::dns_connection (connection *c)
723: c (c) 754: c (c)
724, rcvdq (MAX_BACKLOG * 2) 755, rcvdq (MAX_BACKLOG * 2)
725, snddq (MAX_BACKLOG * 2) 756, snddq (MAX_BACKLOG)
726, tw (this, &dns_connection::time_cb)
727{ 757{
758 tw.set<dns_connection, &dns_connection::time_cb> (this);
759
728 vpn = c->vpn; 760 vpn = c->vpn;
729 761
730 established = false; 762 established = false;
731 763
732 rcvseq = sndseq = 0; 764 rcvseq = repseq = sndseq = 0;
733 765
734 last_sent = last_received = 0; 766 last_sent = last_received = 0;
735 poll_interval = MIN_POLL_INTERVAL; 767 poll_interval = 0.5; // starting here
736 send_interval = 0.5; // starting rate 768 send_interval = 0.5; // starting rate
737 min_latency = INITIAL_TIMEOUT; 769 min_latency = INITIAL_TIMEOUT;
738} 770}
739 771
740dns_connection::~dns_connection () 772dns_connection::~dns_connection ()
… …
743 i != rcvpq.end (); 775 i != rcvpq.end ();
744 ++i) 776 ++i)
745 delete *i; 777 delete *i;
746} 778}
747 779
780void
748void dns_connection::receive_rep (dns_rcv *r) 781dns_connection::receive_rep (dns_rcv *r)
749{ 782{
750 if (r->datalen) 783 if (r->datalen)
751 { 784 {
752 last_received = NOW; 785 last_received = ev_now ();
753 tw.trigger (); 786 tw ();
754 787
755 poll_interval = send_interval; 788 poll_interval = send_interval;
756 } 789 }
757 else 790 else
758 { 791 {
… …
768 801
769 // find next packet 802 // find next packet
770 for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); ) 803 for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); )
771 if (SEQNO_EQ (rcvseq, (*i)->seqno)) 804 if (SEQNO_EQ (rcvseq, (*i)->seqno))
772 { 805 {
806 //printf ("seqno eq %x %x\n", rcvseq, (*i)->seqno);//D
773 // enter the packet into our input stream 807 // enter the packet into our input stream
774 r = *i; 808 r = *i;
775 809
776 // remove the oldest packet, look forward, as it's oldest first 810 // remove the oldest packet, look forward, as it's oldest first
777 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)
778 if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW)) 812 if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW))
779 { 813 {
814 //printf ("seqno RR %x %x\n", (*j)->seqno, rcvseq - MAX_WINDOW);//D
780 delete *j; 815 delete *j;
781 rcvpq.erase (j); 816 rcvpq.erase (j);
782 break; 817 break;
783 } 818 }
784 819
… …
791 } 826 }
792 827
793 while (vpn_packet *pkt = rcvdq.get ()) 828 while (vpn_packet *pkt = rcvdq.get ())
794 { 829 {
795 sockinfo si; 830 sockinfo si;
796 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;
797 832
798 vpn->recv_vpn_packet (pkt, si); 833 vpn->recv_vpn_packet (pkt, si);
799 834
800 delete pkt; 835 delete pkt;
801 } 836 }
… …
855 if (0 < client && client <= conns.size ()) 890 if (0 < client && client <= conns.size ())
856 { 891 {
857 connection *c = conns [client - 1]; 892 connection *c = conns [client - 1];
858 dns_connection *dns = c->dns; 893 dns_connection *dns = c->dns;
859 dns_rcv *rcv; 894 dns_rcv *rcv;
860 bool in_seq;
861 895
862 if (dns) 896 if (dns)
863 { 897 {
864 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 (); )
865 if (SEQNO_EQ ((*i)->seqno, seqno)) 899 if (SEQNO_EQ ((*i)->seqno, seqno))
… …
876 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);
877 911
878 goto duplicate_request; 912 goto duplicate_request;
879 } 913 }
880 914
881 in_seq = dns->rcvseq == seqno;
882
883 // new packet, queue 915 // new packet, queue
884 rcv = new dns_rcv (seqno, data, datalen); 916 rcv = new dns_rcv (seqno, data, datalen);
885 dns->receive_rep (rcv); 917 dns->receive_rep (rcv);
886 } 918 }
887 919
… …
894 pkt [offs++] = 0; pkt [offs++] = 0; 926 pkt [offs++] = 0; pkt [offs++] = 0;
895 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
896 928
897 int rdlen_offs = offs += 2; 929 int rdlen_offs = offs += 2;
898 930
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) 931 if (dns)
904 { 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
905 // only put data into in-order sequence packets, if 938 // only put data into in-order sequence packets, if
906 // we receive out-of-order packets we generate empty 939 // we receive out-of-order packets we generate empty
907 // replies 940 // replies
908 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)
909 { 943 {
944 dns->repseq = seqno;
945
946 while (dlen > 1 && !dns->snddq.empty ())
947 {
910 int txtlen = dlen <= 255 ? dlen - 1 : 255; 948 int txtlen = dlen <= 255 ? dlen - 1 : 255;
911 949
912 if (txtlen > dns->snddq.size ()) 950 if (txtlen > dns->snddq.size ())
913 txtlen = dns->snddq.size (); 951 txtlen = dns->snddq.size ();
914 952
915 pkt[offs++] = txtlen; 953 pkt[offs++] = txtlen;
916 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen); 954 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
917 offs += txtlen; 955 offs += txtlen;
918 dns->snddq.remove (txtlen); 956 dns->snddq.remove (txtlen);
919 957
920 dlen -= txtlen + 1; 958 dlen -= txtlen + 1;
959 }
921 } 960 }
922 961
923 // avoid empty TXT rdata 962 // avoid completely empty TXT rdata
924 if (offs == rdlen_offs) 963 if (offs == rdlen_offs)
925 pkt[offs++] = 0; 964 pkt[offs++] = 0;
926 965
927 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ()); 966 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
928 } 967 }
… …
1008 { 1047 {
1009 dns_connection *dns = (*i)->dns; 1048 dns_connection *dns = (*i)->dns;
1010 connection *c = dns->c; 1049 connection *c = dns->c;
1011 int seqno = (*i)->seqno; 1050 int seqno = (*i)->seqno;
1012 u8 data[MAXSIZE], *datap = data; 1051 u8 data[MAXSIZE], *datap = data;
1052 //printf ("rcv pkt %x\n", seqno);//D
1013 1053
1014 if ((*i)->retry) 1054 if ((*i)->retry)
1015 { 1055 {
1016 dns->send_interval *= 1.01; 1056 dns->send_interval *= 1.01;
1017 if (dns->send_interval > MAX_SEND_INTERVAL) 1057 if (dns->send_interval > MAX_SEND_INTERVAL)
… …
1020 else 1060 else
1021 { 1061 {
1022#if 0 1062#if 0
1023 dns->send_interval *= 0.999; 1063 dns->send_interval *= 0.999;
1024#endif 1064#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 1065 // the latency surely puts an upper bound on
1029 // the minimum send interval 1066 // the minimum send interval
1030 double latency = NOW - (*i)->sent; 1067 double latency = ev_now () - (*i)->sent;
1031 1068
1032 if (latency < dns->min_latency) 1069 if (latency < dns->min_latency)
1033 dns->min_latency = latency; 1070 dns->min_latency = latency;
1034 1071
1035 if (dns->send_interval > dns->min_latency * LATENCY_FACTOR) 1072 if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor)
1036 dns->send_interval = dns->min_latency * LATENCY_FACTOR; 1073 dns->send_interval = dns->min_latency * conf.dns_overlap_factor;
1074
1075 if (dns->send_interval < conf.dns_send_interval)
1076 dns->send_interval = conf.dns_send_interval;
1037 } 1077 }
1038 1078
1039 delete *i; 1079 delete *i;
1040 dns_sndpq.erase (i); 1080 dns_sndpq.erase (i);
1041 1081
… …
1146 break; 1186 break;
1147 } 1187 }
1148} 1188}
1149 1189
1150void 1190void
1151vpn::dnsv4_ev (io_watcher &w, short revents) 1191vpn::dnsv4_ev (ev::io &w, int revents)
1152{ 1192{
1153 if (revents & EVENT_READ) 1193 if (revents & EV_READ)
1154 { 1194 {
1155 dns_packet *pkt = new dns_packet; 1195 dns_packet *pkt = new dns_packet;
1156 struct sockaddr_in sa; 1196 struct sockaddr_in sa;
1157 socklen_t sa_len = sizeof (sa); 1197 socklen_t sa_len = sizeof (sa);
1158 1198
… …
1174} 1214}
1175 1215
1176bool 1216bool
1177vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) 1217vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
1178{ 1218{
1179 int client = ntohs (si.port); 1219 int client = ntohl (si.host);
1180 1220
1181 assert (0 < client && client <= conns.size ()); 1221 assert (0 < client && client <= conns.size ());
1182 1222
1183 connection *c = conns [client - 1]; 1223 connection *c = conns [client - 1];
1184 1224
1185 if (!c->dns) 1225 if (!c->dns)
1186 c->dns = new dns_connection (c); 1226 c->dns = new dns_connection (c);
1187 1227
1188 if (!c->dns->snddq.put (pkt)) 1228 if (c->dns->snddq.put (pkt))
1189 return false;
1190
1191 c->dns->tw.trigger (); 1229 c->dns->tw ();
1192 1230
1231 // always return true even if the buffer overflows
1193 return true; 1232 return true;
1194} 1233}
1195 1234
1196void 1235void
1197connection::dnsv4_reset_connection () 1236connection::dnsv4_reset_connection ()
… …
1200} 1239}
1201 1240
1202#define NEXT(w) do { if (next > (w)) next = w; } while (0) 1241#define NEXT(w) do { if (next > (w)) next = w; } while (0)
1203 1242
1204void 1243void
1205dns_connection::time_cb (time_watcher &w) 1244dns_connection::time_cb (ev::timer &w, int revents)
1206{ 1245{
1207 // servers have to be polled 1246 // servers have to be polled
1208 if (THISNODE->dns_port) 1247 if (THISNODE->dns_port)
1209 return; 1248 return;
1210 1249
1211 // check for timeouts and (re)transmit 1250 // check for timeouts and (re)transmit
1212 tstamp next = NOW + poll_interval; 1251 tstamp next = ev::now () + poll_interval;
1213 dns_snd *send = 0; 1252 dns_snd *send = 0;
1214 1253
1215 for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin (); 1254 for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin ();
1216 i != vpn->dns_sndpq.end (); 1255 i != vpn->dns_sndpq.end ();
1217 ++i) 1256 ++i)
1218 { 1257 {
1219 dns_snd *r = *i; 1258 dns_snd *r = *i;
1220 1259
1221 if (r->timeout <= NOW) 1260 if (r->timeout <= ev_now ())
1222 { 1261 {
1223 if (!send) 1262 if (!send)
1224 { 1263 {
1225 send = r; 1264 send = r;
1226 1265
1227 r->retry++; 1266 r->retry++;
1228 r->timeout = NOW + (r->retry * min_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
1229 1269
1230 // the following code changes the query section a bit, forcing 1270 // the following code changes the query section a bit, forcing
1231 // the forwarder to generate a new request 1271 // the forwarder to generate a new request
1232 if (r->stdhdr) 1272 if (r->stdhdr)
1233 {
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);
1235 //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);
1236 }
1237 } 1274 }
1238 } 1275 }
1239 else 1276 else
1240 NEXT (r->timeout); 1277 NEXT (r->timeout);
1241 } 1278 }
1242 1279
1243 if (last_sent + send_interval <= NOW)
1244 {
1245 if (!send) 1280 if (!send)
1281 {
1282 // generate a new packet, if wise
1283
1284 if (!established)
1246 { 1285 {
1247 // generate a new packet, if wise 1286 if (vpn->dns_sndpq.empty ())
1248
1249 if (!established)
1250 { 1287 {
1251 if (vpn->dns_sndpq.empty ())
1252 {
1253 send = new dns_snd (this); 1288 send = new dns_snd (this);
1254 1289
1255 cfg.reset (THISNODE->id); 1290 cfg.reset (THISNODE->id);
1256 send->gen_syn_req (); 1291 send->gen_syn_req ();
1257 }
1258 } 1292 }
1259 else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING 1293 }
1294 else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding
1260 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) 1295 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
1296 {
1297 if (last_sent + send_interval <= ev_now ())
1261 { 1298 {
1262 //printf ("sending data request etc.\n"); //D 1299 //printf ("sending data request etc.\n"); //D
1263 if (!snddq.empty () || last_received + 1. > NOW) 1300 if (!snddq.empty () || last_received + 1. > ev_now ())
1264 { 1301 {
1265 poll_interval = send_interval; 1302 poll_interval = send_interval;
1266 NEXT (NOW + send_interval); 1303 NEXT (ev_now () + send_interval);
1267 } 1304 }
1268 1305
1269 send = new dns_snd (this); 1306 send = new dns_snd (this);
1270 send->gen_stream_req (sndseq, snddq); 1307 send->gen_stream_req (sndseq, snddq);
1271 send->timeout = NOW + min_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
1272 1310
1273 sndseq = (sndseq + 1) & SEQNO_MASK; 1311 sndseq = (sndseq + 1) & SEQNO_MASK;
1274 } 1312 }
1275 1313 else
1276 if (send) 1314 NEXT (last_sent + send_interval);
1277 vpn->dns_sndpq.push_back (send);
1278 } 1315 }
1279 1316
1280 if (send) 1317 if (send)
1281 { 1318 vpn->dns_sndpq.push_back (send);
1282 last_sent = NOW; 1319 }
1320
1321 if (send)
1322 {
1323 last_sent = ev_now ();
1283 sendto (vpn->dnsv4_fd, 1324 sendto (vpn->dnsv4_fd,
1284 send->pkt->at (0), send->pkt->len, 0, 1325 send->pkt->at (0), send->pkt->len, 0,
1285 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); 1326 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
1286 }
1287 } 1327 }
1288 else
1289 NEXT (last_sent + send_interval);
1290 1328
1291 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)",
1292 poll_interval, send_interval, next - NOW, 1330 poll_interval, send_interval, next - ev_now (),
1293 vpn->dns_sndpq.size (), snddq.size ()); 1331 vpn->dns_sndpq.size (), snddq.size (),
1332 rcvpq.size ());
1294 1333
1295 // 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
1296 if (next < NOW + 0.0001) 1336 if (next < ev_now () + 0.001)
1297 next = NOW + 0.1; 1337 next = ev_now () + 0.1;
1298 1338
1299 w.start (next); 1339 w.start (next - ev_now ());
1300} 1340}
1301 1341
1302#endif 1342#endif
1303 1343

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