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Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.30 by pcg, Mon Mar 14 17:40:01 2005 UTC vs.
Revision 1.50 by root, Sun Mar 6 13:49:50 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 MAX_POLL_INTERVAL 5. // 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
50#define ACTIVITY_INTERVAL 5. 65#define ACTIVITY_INTERVAL 5.
51 66
52#define INITIAL_TIMEOUT 0.1 // retry timeouts 67#define INITIAL_TIMEOUT 0.1 // retry timeouts
53#define INITIAL_SYN_TIMEOUT 10. // retry timeout for initial syn 68#define INITIAL_SYN_TIMEOUT 2. // retry timeout for initial syn
54 69
55#define MIN_SEND_INTERVAL 0.001 // wait at least this time between sending requests
56#define MAX_SEND_INTERVAL 2. // optimistic? 70#define MAX_SEND_INTERVAL 2. // optimistic?
57 71
58#define LATENCY_FACTOR 0.5 // RTT * LATENCY_FACTOR == sending rate
59#define MAX_OUTSTANDING 2 // 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 240 // 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
… …
104 memset (enc, (char) 0, 256); 117 memset (enc, (char) 0, 256);
105 memset (dec, (char)INVALID, 256); 118 memset (dec, (char)INVALID, 256);
106 119
107 for (size = 0; cmap [size]; size++) 120 for (size = 0; cmap [size]; size++)
108 { 121 {
122 char c = cmap [size];
123
109 enc [size] = cmap [size]; 124 enc [size] = c;
110 dec [(u8)enc [size]] = size; 125 dec [(u8)c] = size;
126
127 // allow lowercase/uppercase aliases if possible
128 if (c >= 'A' && c <= 'Z' && dec [c + ('a' - 'A')] == INVALID) dec [c + ('a' - 'A')] = size;
129 if (c >= 'a' && c <= 'z' && dec [c - ('a' - 'A')] == INVALID) dec [c - ('a' - 'A')] = size;
111 } 130 }
112 131
113 assert (size < 256); 132 assert (size < 256);
114} 133}
115 134
… …
155 enc_len [len] = n; 174 enc_len [len] = n;
156 dec_len [n] = len; 175 dec_len [n] = len;
157 } 176 }
158} 177}
159 178
179unsigned int
160unsigned int basecoder::encode_len (unsigned int len) 180basecoder::encode_len (unsigned int len)
161{ 181{
162 return enc_len [len]; 182 return enc_len [len];
163} 183}
164 184
185unsigned int
165unsigned int basecoder::decode_len (unsigned int len) 186basecoder::decode_len (unsigned int len)
166{ 187{
167 while (len && !dec_len [len]) 188 while (len && !dec_len [len])
168 --len; 189 --len;
169 190
170 return dec_len [len]; 191 return dec_len [len];
171} 192}
172 193
194unsigned int
173unsigned int basecoder::encode (char *dst, u8 *src, unsigned int len) 195basecoder::encode (char *dst, u8 *src, unsigned int len)
174{ 196{
175 if (!len || len > MAX_DEC_LEN) 197 if (!len || len > MAX_DEC_LEN)
176 return 0; 198 return 0;
177 199
178 int elen = encode_len (len); 200 int elen = encode_len (len);
… …
197 *dst++ = cmap.encode [dst_ [i]]; 219 *dst++ = cmap.encode [dst_ [i]];
198 220
199 return elen; 221 return elen;
200} 222}
201 223
224unsigned int
202unsigned int basecoder::decode (u8 *dst, char *src, unsigned int len) 225basecoder::decode (u8 *dst, char *src, unsigned int len)
203{ 226{
204 if (!len || len > MAX_ENC_LEN) 227 if (!len || len > MAX_ENC_LEN)
205 return 0; 228 return 0;
206 229
207 u8 src_ [MAX_ENC_LEN]; 230 u8 src_ [MAX_ENC_LEN];
… …
266 289
267///////////////////////////////////////////////////////////////////////////// 290/////////////////////////////////////////////////////////////////////////////
268 291
269#define HDRSIZE 6 292#define HDRSIZE 6
270 293
294inline void
271inline void encode_header (char *data, int clientid, int seqno, int retry = 0) 295encode_header (char *data, int clientid, int seqno, int retry = 0)
272{ 296{
273 seqno &= SEQNO_MASK; 297 seqno &= SEQNO_MASK;
274 298
275 u8 hdr[3] = { 299 u8 hdr[3] = {
276 clientid, 300 clientid,
… …
281 assert (clientid < 256); 305 assert (clientid < 256);
282 306
283 cdc26.encode (data, hdr, 3); 307 cdc26.encode (data, hdr, 3);
284} 308}
285 309
310inline void
286inline void decode_header (char *data, int &clientid, int &seqno) 311decode_header (char *data, int &clientid, int &seqno)
287{ 312{
288 u8 hdr[3]; 313 u8 hdr[3];
289 314
290 cdc26.decode (hdr, data, HDRSIZE); 315 cdc26.decode (hdr, data, HDRSIZE);
291 316
… …
324byte_stream::~byte_stream () 349byte_stream::~byte_stream ()
325{ 350{
326 delete data; 351 delete data;
327} 352}
328 353
354void
329void byte_stream::remove (int count) 355byte_stream::remove (int count)
330{ 356{
331 if (count > fill) 357 if (count > fill)
332 assert (count <= fill); 358 assert (count <= fill);
333 359
334 memmove (data, data + count, fill -= count); 360 memmove (data, data + count, fill -= count);
335} 361}
336 362
363bool
337bool byte_stream::put (u8 *data, unsigned int datalen) 364byte_stream::put (u8 *data, unsigned int datalen)
338{ 365{
339 if (maxsize - fill < datalen) 366 if (maxsize - fill < datalen)
340 return false; 367 return false;
341 368
342 memcpy (this->data + fill, data, datalen); fill += datalen; 369 memcpy (this->data + fill, data, datalen); fill += datalen;
343 370
344 return true; 371 return true;
345} 372}
346 373
374bool
347bool byte_stream::put (vpn_packet *pkt) 375byte_stream::put (vpn_packet *pkt)
348{ 376{
349 if (maxsize - fill < pkt->len + 2) 377 if (maxsize - fill < pkt->len + 2)
350 return false; 378 return false;
351 379
352 data [fill++] = pkt->len >> 8; 380 data [fill++] = pkt->len >> 8;
… …
434 bool valid (); 462 bool valid ();
435}; 463};
436 464
437int dns_cfg::next_uid; 465int dns_cfg::next_uid;
438 466
467void
439void dns_cfg::reset (int clientid) 468dns_cfg::reset (int clientid)
440{ 469{
441 id1 = 'G'; 470 id1 = 'G';
442 id2 = 'V'; 471 id2 = 'V';
443 id3 = 'P'; 472 id3 = 'P';
444 id4 = 'E'; 473 id4 = 'E';
… …
458 487
459 r3 = r4 = 0; 488 r3 = r4 = 0;
460 r4 = r5 = r6 = r7 = 0; 489 r4 = r5 = r6 = r7 = 0;
461} 490}
462 491
492bool
463bool dns_cfg::valid () 493dns_cfg::valid ()
464{ 494{
495 // although the protocol itself allows for some configurability,
496 // only the following encoding/decoding settings are implemented.
465 return id1 == 'G' 497 return id1 == 'G'
466 && id2 == 'V' 498 && id2 == 'V'
467 && id3 == 'P' 499 && id3 == 'P'
468 && id4 == 'E' 500 && id4 == 'E'
469 && seq_cdc == 26 501 && seq_cdc == 26
… …
481 u8 data [MAXSIZE - 6 * 2]; 513 u8 data [MAXSIZE - 6 * 2];
482 514
483 int decode_label (char *data, int size, int &offs); 515 int decode_label (char *data, int size, int &offs);
484}; 516};
485 517
518int
486int dns_packet::decode_label (char *data, int size, int &offs) 519dns_packet::decode_label (char *data, int size, int &offs)
487{ 520{
488 char *orig = data; 521 char *orig = data;
489 522
490 memset (data, 0, size); 523 memset (data, 0, size);
491 524
… …
517 return data - orig; 550 return data - orig;
518} 551}
519 552
520///////////////////////////////////////////////////////////////////////////// 553/////////////////////////////////////////////////////////////////////////////
521 554
555static
556u16 next_id ()
557{
522static u16 dns_id = 0; // TODO: should be per-vpn 558 static u16 dns_id = 0; // TODO: should be per-vpn
523 559
524static u16 next_id ()
525{
526 if (!dns_id) 560 if (!dns_id)
527 dns_id = time (0); 561 dns_id = time (0);
528 562
529 // the simplest lsfr with periodicity 65535 i could find 563 // the simplest lsfr with periodicity 65535 i could find
530 dns_id = (dns_id << 1) 564 dns_id = (dns_id << 1)
… …
553 double min_latency; 587 double min_latency;
554 double poll_interval, send_interval; 588 double poll_interval, send_interval;
555 589
556 vector<dns_rcv *> rcvpq; 590 vector<dns_rcv *> rcvpq;
557 591
558 byte_stream rcvdq; int rcvseq; 592 byte_stream rcvdq; int rcvseq; int repseq;
559 byte_stream snddq; int sndseq; 593 byte_stream snddq; int sndseq;
560 594
561 void time_cb (time_watcher &w); time_watcher tw; 595 inline void time_cb (ev::timer &w, int revents); ev::timer tw;
562 void receive_rep (dns_rcv *r); 596 void receive_rep (dns_rcv *r);
563 597
564 dns_connection (connection *c); 598 dns_connection (connection *c);
565 ~dns_connection (); 599 ~dns_connection ();
566}; 600};
… …
585: dns (dns) 619: dns (dns)
586{ 620{
587 timeout = 0; 621 timeout = 0;
588 retry = 0; 622 retry = 0;
589 seqno = 0; 623 seqno = 0;
590 sent = NOW; 624 sent = ev_now ();
591 stdhdr = false; 625 stdhdr = false;
592 626
593 pkt = new dns_packet; 627 pkt = new dns_packet;
594 628
595 pkt->id = next_id (); 629 pkt->id = next_id ();
… …
598dns_snd::~dns_snd () 632dns_snd::~dns_snd ()
599{ 633{
600 delete pkt; 634 delete pkt;
601} 635}
602 636
637static void
603static void append_domain (dns_packet &pkt, int &offs, const char *domain) 638append_domain (dns_packet &pkt, int &offs, const char *domain)
604{ 639{
605 // add tunnel domain 640 // add tunnel domain
606 for (;;) 641 for (;;)
607 { 642 {
608 const char *end = strchr (domain, '.'); 643 const char *end = strchr (domain, '.');
… …
621 656
622 domain = end + 1; 657 domain = end + 1;
623 } 658 }
624} 659}
625 660
661void
626void dns_snd::gen_stream_req (int seqno, byte_stream &stream) 662dns_snd::gen_stream_req (int seqno, byte_stream &stream)
627{ 663{
628 stdhdr = true; 664 stdhdr = true;
629 this->seqno = seqno; 665 this->seqno = seqno;
630 666
631 timeout = NOW + INITIAL_TIMEOUT; 667 timeout = ev_now () + INITIAL_TIMEOUT;
632 668
633 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 669 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
634 pkt->qdcount = htons (1); 670 pkt->qdcount = htons (1);
635 671
636 int offs = 6*2; 672 int offs = 6*2;
… …
669 (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN; 705 (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN;
670 706
671 pkt->len = offs; 707 pkt->len = offs;
672} 708}
673 709
710void
674void dns_snd::gen_syn_req () 711dns_snd::gen_syn_req ()
675{ 712{
676 timeout = NOW + INITIAL_SYN_TIMEOUT; 713 timeout = ev_now () + INITIAL_SYN_TIMEOUT;
677 714
678 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 715 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
679 pkt->qdcount = htons (1); 716 pkt->qdcount = htons (1);
680 717
681 int offs = 6 * 2; 718 int offs = 6 * 2;
… …
720///////////////////////////////////////////////////////////////////////////// 757/////////////////////////////////////////////////////////////////////////////
721 758
722dns_connection::dns_connection (connection *c) 759dns_connection::dns_connection (connection *c)
723: c (c) 760: c (c)
724, rcvdq (MAX_BACKLOG * 2) 761, rcvdq (MAX_BACKLOG * 2)
725, snddq (MAX_BACKLOG * 2) 762, snddq (MAX_BACKLOG)
726, tw (this, &dns_connection::time_cb)
727{ 763{
764 tw.set<dns_connection, &dns_connection::time_cb> (this);
765
728 vpn = c->vpn; 766 vpn = c->vpn;
729 767
730 established = false; 768 established = false;
731 769
732 rcvseq = sndseq = 0; 770 rcvseq = repseq = sndseq = 0;
733 771
734 last_sent = last_received = 0; 772 last_sent = last_received = 0;
735 poll_interval = 0.5; // starting here 773 poll_interval = 0.5; // starting here
736 send_interval = 0.5; // starting rate 774 send_interval = 0.5; // starting rate
737 min_latency = INITIAL_TIMEOUT; 775 min_latency = INITIAL_TIMEOUT;
… …
743 i != rcvpq.end (); 781 i != rcvpq.end ();
744 ++i) 782 ++i)
745 delete *i; 783 delete *i;
746} 784}
747 785
786void
748void dns_connection::receive_rep (dns_rcv *r) 787dns_connection::receive_rep (dns_rcv *r)
749{ 788{
750 if (r->datalen) 789 if (r->datalen)
751 { 790 {
752 last_received = NOW; 791 last_received = ev_now ();
753 tw.trigger (); 792 tw ();
754 793
755 poll_interval = send_interval; 794 poll_interval = send_interval;
756 } 795 }
757 else 796 else
758 { 797 {
… …
768 807
769 // find next packet 808 // find next packet
770 for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); ) 809 for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); )
771 if (SEQNO_EQ (rcvseq, (*i)->seqno)) 810 if (SEQNO_EQ (rcvseq, (*i)->seqno))
772 { 811 {
812 //printf ("seqno eq %x %x\n", rcvseq, (*i)->seqno);//D
773 // enter the packet into our input stream 813 // enter the packet into our input stream
774 r = *i; 814 r = *i;
775 815
776 // remove the oldest packet, look forward, as it's oldest first 816 // remove the oldest packet, look forward, as it's oldest first
777 for (vector<dns_rcv *>::iterator j = rcvpq.begin (); j != rcvpq.end (); ++j) 817 for (vector<dns_rcv *>::iterator j = rcvpq.begin (); j != rcvpq.end (); ++j)
778 if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW)) 818 if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW))
779 { 819 {
820 //printf ("seqno RR %x %x\n", (*j)->seqno, rcvseq - MAX_WINDOW);//D
780 delete *j; 821 delete *j;
781 rcvpq.erase (j); 822 rcvpq.erase (j);
782 break; 823 break;
783 } 824 }
784 825
785 rcvseq = (rcvseq + 1) & SEQNO_MASK; 826 rcvseq = (rcvseq + 1) & SEQNO_MASK;
786 827
787 if (!rcvdq.put (r->data, r->datalen)) 828 if (!rcvdq.put (r->data, r->datalen))
788 { 829 {
830 // MUST never overflow, can be caused by data corruption, TODO
789 slog (L_ERR, "DNS: !rcvdq.put (r->data, r->datalen)"); 831 slog (L_CRIT, "DNS: !rcvdq.put (r->data, r->datalen)");
790 abort (); // MUST never overflow, can be caused by data corruption, TODO 832 c->dnsv4_reset_connection ();
833 return;
791 } 834 }
792 835
793 while (vpn_packet *pkt = rcvdq.get ()) 836 while (vpn_packet *pkt = rcvdq.get ())
794 { 837 {
795 sockinfo si; 838 sockinfo si;
796 si.host = 0x01010101; si.port = htons (c->conf->id); si.prot = PROT_DNSv4; 839 si.host = htonl (c->conf->id); si.port = 0; si.prot = PROT_DNSv4;
797 840
798 vpn->recv_vpn_packet (pkt, si); 841 vpn->recv_vpn_packet (pkt, si);
799
800 delete pkt; 842 delete pkt;
801 } 843 }
802 844
803 // check for further packets 845 // check for further packets
804 goto redo; 846 goto redo;
… …
855 if (0 < client && client <= conns.size ()) 897 if (0 < client && client <= conns.size ())
856 { 898 {
857 connection *c = conns [client - 1]; 899 connection *c = conns [client - 1];
858 dns_connection *dns = c->dns; 900 dns_connection *dns = c->dns;
859 dns_rcv *rcv; 901 dns_rcv *rcv;
860 bool in_seq;
861 902
862 if (dns) 903 if (dns)
863 { 904 {
864 for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); ) 905 for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); )
865 if (SEQNO_EQ ((*i)->seqno, seqno)) 906 if (SEQNO_EQ ((*i)->seqno, seqno))
… …
876 memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len); 917 memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len);
877 918
878 goto duplicate_request; 919 goto duplicate_request;
879 } 920 }
880 921
881 in_seq = dns->rcvseq == seqno;
882
883 // new packet, queue 922 // new packet, queue
884 rcv = new dns_rcv (seqno, data, datalen); 923 rcv = new dns_rcv (seqno, data, datalen);
885 dns->receive_rep (rcv); 924 dns->receive_rep (rcv);
886 } 925 }
887 926
… …
904 dlen -= qlen; 943 dlen -= qlen;
905 944
906 // only put data into in-order sequence packets, if 945 // only put data into in-order sequence packets, if
907 // we receive out-of-order packets we generate empty 946 // we receive out-of-order packets we generate empty
908 // replies 947 // replies
909 while (dlen > 1 && !dns->snddq.empty () && in_seq) 948 //printf ("%d - %d & %x (=%d) < %d\n", seqno, dns->repseq, SEQNO_MASK, (seqno - dns->repseq) & SEQNO_MASK, MAX_WINDOW);//D
949 if (((seqno - dns->repseq) & SEQNO_MASK) <= MAX_WINDOW)
910 { 950 {
951 dns->repseq = seqno;
952
953 while (dlen > 1 && !dns->snddq.empty ())
954 {
911 int txtlen = dlen <= 255 ? dlen - 1 : 255; 955 int txtlen = dlen <= 255 ? dlen - 1 : 255;
912 956
913 if (txtlen > dns->snddq.size ()) 957 if (txtlen > dns->snddq.size ())
914 txtlen = dns->snddq.size (); 958 txtlen = dns->snddq.size ();
915 959
916 pkt[offs++] = txtlen; 960 pkt[offs++] = txtlen;
917 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen); 961 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
918 offs += txtlen; 962 offs += txtlen;
919 dns->snddq.remove (txtlen); 963 dns->snddq.remove (txtlen);
920 964
921 dlen -= txtlen + 1; 965 dlen -= txtlen + 1;
966 }
922 } 967 }
923 968
924 // avoid empty TXT rdata 969 // avoid completely empty TXT rdata
925 if (offs == rdlen_offs) 970 if (offs == rdlen_offs)
926 pkt[offs++] = 0; 971 pkt[offs++] = 0;
927 972
928 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ()); 973 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
929 } 974 }
… …
1009 { 1054 {
1010 dns_connection *dns = (*i)->dns; 1055 dns_connection *dns = (*i)->dns;
1011 connection *c = dns->c; 1056 connection *c = dns->c;
1012 int seqno = (*i)->seqno; 1057 int seqno = (*i)->seqno;
1013 u8 data[MAXSIZE], *datap = data; 1058 u8 data[MAXSIZE], *datap = data;
1059 //printf ("rcv pkt %x\n", seqno);//D
1014 1060
1015 if ((*i)->retry) 1061 if ((*i)->retry)
1016 { 1062 {
1017 dns->send_interval *= 1.01; 1063 dns->send_interval *= 1.01;
1018 if (dns->send_interval > MAX_SEND_INTERVAL) 1064 if (dns->send_interval > MAX_SEND_INTERVAL)
… …
1023#if 0 1069#if 0
1024 dns->send_interval *= 0.999; 1070 dns->send_interval *= 0.999;
1025#endif 1071#endif
1026 // the latency surely puts an upper bound on 1072 // the latency surely puts an upper bound on
1027 // the minimum send interval 1073 // the minimum send interval
1028 double latency = NOW - (*i)->sent; 1074 double latency = ev_now () - (*i)->sent;
1029 1075
1030 if (latency < dns->min_latency) 1076 if (latency < dns->min_latency)
1031 dns->min_latency = latency; 1077 dns->min_latency = latency;
1032 1078
1033 if (dns->send_interval > dns->min_latency * LATENCY_FACTOR) 1079 if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor)
1034 dns->send_interval = dns->min_latency * LATENCY_FACTOR; 1080 dns->send_interval = dns->min_latency * conf.dns_overlap_factor;
1035 1081
1036 if (dns->send_interval < MIN_SEND_INTERVAL) 1082 if (dns->send_interval < conf.dns_send_interval)
1037 dns->send_interval = MIN_SEND_INTERVAL; 1083 dns->send_interval = conf.dns_send_interval;
1038 } 1084 }
1039 1085
1040 delete *i; 1086 delete *i;
1041 dns_sndpq.erase (i); 1087 dns_sndpq.erase (i);
1042 1088
… …
1098 1144
1099 if (ip [3] == CMD_IP_RST) 1145 if (ip [3] == CMD_IP_RST)
1100 { 1146 {
1101 slog (L_DEBUG, _("DNS: got tunnel RST request")); 1147 slog (L_DEBUG, _("DNS: got tunnel RST request"));
1102 1148
1103 delete dns; c->dns = 0; 1149 c->dnsv4_reset_connection ();
1104
1105 return;
1106 } 1150 }
1107 else if (ip [3] == CMD_IP_SYN) 1151 else if (ip [3] == CMD_IP_SYN)
1108 { 1152 {
1109 slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us.")); 1153 slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us."));
1110 dns->established = true; 1154 dns->established = true;
1111 } 1155 }
1112 else if (ip [3] == CMD_IP_REJ) 1156 else if (ip [3] == CMD_IP_REJ)
1113 {
1114 slog (L_DEBUG, _("DNS: got tunnel REJ reply, server does not like us, aborting.")); 1157 slog (L_ERR, _("DNS: got tunnel REJ reply, server does not like us."));
1115 abort ();
1116 }
1117 else 1158 else
1118 slog (L_INFO, _("DNS: got unknown meta command %02x"), ip [3]); 1159 slog (L_INFO, _("DNS: got unknown meta command %02x"), ip [3]);
1119 } 1160 }
1120 else 1161 else
1121 slog (L_INFO, _("DNS: got spurious a record %d.%d.%d.%d"), 1162 slog (L_INFO, _("DNS: got spurious a record %d.%d.%d.%d"),
… …
1147 break; 1188 break;
1148 } 1189 }
1149} 1190}
1150 1191
1151void 1192void
1152vpn::dnsv4_ev (io_watcher &w, short revents) 1193vpn::dnsv4_ev (ev::io &w, int revents)
1153{ 1194{
1154 if (revents & EVENT_READ) 1195 if (revents & EV_READ)
1155 { 1196 {
1156 dns_packet *pkt = new dns_packet; 1197 dns_packet *pkt = new dns_packet;
1157 struct sockaddr_in sa; 1198 struct sockaddr_in sa;
1158 socklen_t sa_len = sizeof (sa); 1199 socklen_t sa_len = sizeof (sa);
1159 1200
… …
1175} 1216}
1176 1217
1177bool 1218bool
1178vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) 1219vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
1179{ 1220{
1180 int client = ntohs (si.port); 1221 int client = ntohl (si.host);
1181 1222
1182 assert (0 < client && client <= conns.size ()); 1223 assert (0 < client && client <= conns.size ());
1183 1224
1184 connection *c = conns [client - 1]; 1225 connection *c = conns [client - 1];
1185 1226
1186 if (!c->dns) 1227 if (!c->dns)
1187 c->dns = new dns_connection (c); 1228 c->dns = new dns_connection (c);
1188 1229
1189 if (!c->dns->snddq.put (pkt)) 1230 if (c->dns->snddq.put (pkt))
1190 return false;
1191
1192 c->dns->tw.trigger (); 1231 c->dns->tw ();
1193 1232
1233 // always return true even if the buffer overflows
1194 return true; 1234 return true;
1195} 1235}
1196 1236
1197void 1237void
1198connection::dnsv4_reset_connection () 1238connection::dnsv4_reset_connection ()
… …
1201} 1241}
1202 1242
1203#define NEXT(w) do { if (next > (w)) next = w; } while (0) 1243#define NEXT(w) do { if (next > (w)) next = w; } while (0)
1204 1244
1205void 1245void
1206dns_connection::time_cb (time_watcher &w) 1246dns_connection::time_cb (ev::timer &w, int revents)
1207{ 1247{
1208 // servers have to be polled 1248 // servers have to be polled
1209 if (THISNODE->dns_port) 1249 if (THISNODE->dns_port)
1210 return; 1250 return;
1211 1251
1212 // check for timeouts and (re)transmit 1252 // check for timeouts and (re)transmit
1213 tstamp next = NOW + poll_interval; 1253 tstamp next = ev::now () + poll_interval;
1214 dns_snd *send = 0; 1254 dns_snd *send = 0;
1215 1255
1216 for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin (); 1256 for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin ();
1217 i != vpn->dns_sndpq.end (); 1257 i != vpn->dns_sndpq.end ();
1218 ++i) 1258 ++i)
1219 { 1259 {
1220 dns_snd *r = *i; 1260 dns_snd *r = *i;
1221 1261
1222 if (r->timeout <= NOW) 1262 if (r->timeout <= ev_now ())
1223 { 1263 {
1224 if (!send) 1264 if (!send)
1225 { 1265 {
1226 send = r; 1266 send = r;
1227 1267
1228 r->retry++; 1268 r->retry++;
1229 r->timeout = NOW + (r->retry * min_latency * 8.); 1269 r->timeout = ev_now () + (r->retry * min_latency * conf.dns_timeout_factor);
1270 //printf ("RETRY %x (%d, %f)\n", r->seqno, r->retry, r->timeout - ev_now ());//D
1230 1271
1231 // the following code changes the query section a bit, forcing 1272 // the following code changes the query section a bit, forcing
1232 // the forwarder to generate a new request 1273 // the forwarder to generate a new request
1233 if (r->stdhdr) 1274 if (r->stdhdr)
1234 {
1235 //printf ("reencoded header for ID %d retry %d:%d:%d (%p)\n", htons (r->pkt->id), THISNODE->id, r->seqno, r->retry);
1236 //encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry); 1275 encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry);
1237 }
1238 } 1276 }
1239 } 1277 }
1240 else 1278 else
1241 NEXT (r->timeout); 1279 NEXT (r->timeout);
1242 } 1280 }
… …
1253 1291
1254 cfg.reset (THISNODE->id); 1292 cfg.reset (THISNODE->id);
1255 send->gen_syn_req (); 1293 send->gen_syn_req ();
1256 } 1294 }
1257 } 1295 }
1258 else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING 1296 else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding
1259 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) 1297 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
1260 { 1298 {
1261 if (last_sent + send_interval <= NOW) 1299 if (last_sent + send_interval <= ev_now ())
1262 { 1300 {
1263 //printf ("sending data request etc.\n"); //D 1301 //printf ("sending data request etc.\n"); //D
1264 if (!snddq.empty () || last_received + 1. > NOW) 1302 if (!snddq.empty () || last_received + 1. > ev_now ())
1265 { 1303 {
1266 poll_interval = send_interval; 1304 poll_interval = send_interval;
1267 NEXT (NOW + send_interval); 1305 NEXT (ev_now () + send_interval);
1268 } 1306 }
1269 1307
1270 send = new dns_snd (this); 1308 send = new dns_snd (this);
1271 send->gen_stream_req (sndseq, snddq); 1309 send->gen_stream_req (sndseq, snddq);
1272 send->timeout = NOW + min_latency * 8.; 1310 send->timeout = ev_now () + min_latency * conf.dns_timeout_factor;
1311 //printf ("SEND %x (%f)\n", send->seqno, send->timeout - ev_now (), min_latency, conf.dns_timeout_factor);//D
1273 1312
1274 sndseq = (sndseq + 1) & SEQNO_MASK; 1313 sndseq = (sndseq + 1) & SEQNO_MASK;
1275 } 1314 }
1276 else 1315 else
1277 NEXT (last_sent + send_interval); 1316 NEXT (last_sent + send_interval);
… …
1281 vpn->dns_sndpq.push_back (send); 1320 vpn->dns_sndpq.push_back (send);
1282 } 1321 }
1283 1322
1284 if (send) 1323 if (send)
1285 { 1324 {
1286 last_sent = NOW; 1325 last_sent = ev_now ();
1287 sendto (vpn->dnsv4_fd, 1326 sendto (vpn->dnsv4_fd,
1288 send->pkt->at (0), send->pkt->len, 0, 1327 send->pkt->at (0), send->pkt->len, 0,
1289 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); 1328 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
1290 } 1329 }
1291 1330
1292 slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)", 1331 slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)",
1293 poll_interval, send_interval, next - NOW, 1332 poll_interval, send_interval, next - ev_now (),
1294 vpn->dns_sndpq.size (), snddq.size (), 1333 vpn->dns_sndpq.size (), snddq.size (),
1295 rcvpq.size ()); 1334 rcvpq.size ());
1296 1335
1297 // TODO: no idea when this happens, but when next < NOW, we have a problem 1336 // TODO: no idea when this happens, but when next < ev_now (), we have a problem
1337 // doesn't seem to happen anymore
1298 if (next < NOW + 0.001) 1338 if (next < ev_now () + 0.001)
1299 next = NOW + 0.1; 1339 next = ev_now () + 0.1;
1300 1340
1301 w.start (next); 1341 w.start (next - ev_now ());
1302} 1342}
1303 1343
1304#endif 1344#endif
1305 1345

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