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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 1.53 by root, Tue Oct 18 10:54:17 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) 2003-2011 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 64#define MIN_POLL_INTERVAL 0.025 // poll at most this often when no data received
50#define MAX_POLL_INTERVAL 6. // how often to poll minimally when the server has no data 65#define MAX_POLL_INTERVAL 1. // how often to poll minimally when the server has no data
51#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 5. // 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 235 // 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
81#define CMD_IP_2 46 94#define CMD_IP_2 46
82#define CMD_IP_3 236 95#define CMD_IP_3 236
83#define CMD_IP_RST 29 96
84#define CMD_IP_SYN 113 97#define CMD_IP_RST 29 // some error, reset and retry
85#define CMD_IP_REJ 32 98#define CMD_IP_REJ 32 // do not want you
99#define CMD_IP_SYN 113 // connection established
100#define CMD_IP_CSE 213 // connection established, but likely case mismatch
101
102static bool
103is_uc (char c)
104{
105 return 'A' <= c && c <= 'Z';
106}
107
108static bool
109is_lc (char c)
110{
111 return 'a' <= c && c <= 'z';
112}
86 113
87// works for cmaps up to 255 (not 256!) 114// works for cmaps up to 255 (not 256!)
88struct charmap 115struct charmap
89{ 116{
90 enum { INVALID = (u8)255 }; 117 enum { INVALID = (u8)255 };
… …
104 memset (enc, (char) 0, 256); 131 memset (enc, (char) 0, 256);
105 memset (dec, (char)INVALID, 256); 132 memset (dec, (char)INVALID, 256);
106 133
107 for (size = 0; cmap [size]; size++) 134 for (size = 0; cmap [size]; size++)
108 { 135 {
136 char c = cmap [size];
137
109 enc [size] = cmap [size]; 138 enc [size] = c;
110 dec [(u8)enc [size]] = size; 139 dec [(u8)c] = size;
140
141 // allow lowercase/uppercase aliases if possible
142 if (is_uc (c) && dec [c + ('a' - 'A')] == INVALID) dec [c + ('a' - 'A')] = size;
143 if (is_lc (c) && dec [c - ('a' - 'A')] == INVALID) dec [c - ('a' - 'A')] = size;
111 } 144 }
112 145
113 assert (size < 256); 146 assert (size < 256);
114} 147}
115 148
… …
122{ 155{
123 charmap cmap; 156 charmap cmap;
124 unsigned int enc_len [MAX_DEC_LEN]; 157 unsigned int enc_len [MAX_DEC_LEN];
125 unsigned int dec_len [MAX_ENC_LEN]; 158 unsigned int dec_len [MAX_ENC_LEN];
126 159
127 unsigned int encode_len (unsigned int len); 160 unsigned int encode_len (unsigned int len) const;
128 unsigned int decode_len (unsigned int len); 161 unsigned int decode_len (unsigned int len) const;
129 162
130 unsigned int encode (char *dst, u8 *src, unsigned int len); 163 unsigned int encode (char *dst, u8 *src, unsigned int len) const;
131 unsigned int decode (u8 *dst, char *src, unsigned int len); 164 unsigned int decode (u8 *dst, char *src, unsigned int len) const;
132 165
133 basecoder (const char *cmap); 166 basecoder (const char *cmap);
134}; 167};
135 168
136basecoder::basecoder (const char *cmap) 169basecoder::basecoder (const char *cmap)
… …
155 enc_len [len] = n; 188 enc_len [len] = n;
156 dec_len [n] = len; 189 dec_len [n] = len;
157 } 190 }
158} 191}
159 192
193unsigned int
160unsigned int basecoder::encode_len (unsigned int len) 194basecoder::encode_len (unsigned int len) const
161{ 195{
162 return enc_len [len]; 196 return enc_len [len];
163} 197}
164 198
199unsigned int
165unsigned int basecoder::decode_len (unsigned int len) 200basecoder::decode_len (unsigned int len) const
166{ 201{
167 while (len && !dec_len [len]) 202 while (len && !dec_len [len])
168 --len; 203 --len;
169 204
170 return dec_len [len]; 205 return dec_len [len];
171} 206}
172 207
208unsigned int
173unsigned int basecoder::encode (char *dst, u8 *src, unsigned int len) 209basecoder::encode (char *dst, u8 *src, unsigned int len) const
174{ 210{
175 if (!len || len > MAX_DEC_LEN) 211 if (!len || len > MAX_DEC_LEN)
176 return 0; 212 return 0;
177 213
178 int elen = encode_len (len); 214 int elen = encode_len (len);
… …
197 *dst++ = cmap.encode [dst_ [i]]; 233 *dst++ = cmap.encode [dst_ [i]];
198 234
199 return elen; 235 return elen;
200} 236}
201 237
238unsigned int
202unsigned int basecoder::decode (u8 *dst, char *src, unsigned int len) 239basecoder::decode (u8 *dst, char *src, unsigned int len) const
203{ 240{
204 if (!len || len > MAX_ENC_LEN) 241 if (!len || len > MAX_ENC_LEN)
205 return 0; 242 return 0;
206 243
207 u8 src_ [MAX_ENC_LEN]; 244 u8 src_ [MAX_ENC_LEN];
… …
256 } 293 }
257 abort (); 294 abort ();
258} 295}
259#endif 296#endif
260 297
261//static basecoder cdc64 ("_dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI-");
262//static basecoder cdc63 ("_dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI");
263static basecoder cdc62 ("dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI"); 298static basecoder cdc62 ("dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI"); // a-zA-Z0-9
264//static basecoder cdc36 ("dphzr06qmjkb34tsvl81xaef92wgyo57ucni"); // unused as of yet 299static basecoder cdc36 ("dPhZr06QmJkB34tSvL81xAeF92wGyO57uCnI"); // a-z0-9 for case-changers
265static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO"); 300static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyOuCnI"); // a-z
266 301
267///////////////////////////////////////////////////////////////////////////// 302/////////////////////////////////////////////////////////////////////////////
268 303
269#define HDRSIZE 6 304#define HDRSIZE 5
270 305
306inline void
271inline void encode_header (char *data, int clientid, int seqno, int retry = 0) 307encode_header (char *data, int clientid, int seqno, int retry = 0)
272{ 308{
309 assert (clientid < 256);
310
273 seqno &= SEQNO_MASK; 311 seqno &= SEQNO_MASK;
274 312
275 u8 hdr[3] = { 313 u8 hdr[3] = {
314 seqno,
315 (seqno >> 8) | (retry << 6),
276 clientid, 316 clientid,
277 (seqno >> 8) | (retry << 6),
278 seqno,
279 }; 317 };
280 318
281 assert (clientid < 256);
282
283 cdc26.encode (data, hdr, 3); 319 cdc36.encode (data, hdr, 3);
284} 320}
285 321
322inline void
286inline void decode_header (char *data, int &clientid, int &seqno) 323decode_header (char *data, int &clientid, int &seqno)
287{ 324{
288 u8 hdr[3]; 325 u8 hdr[3];
289 326
290 cdc26.decode (hdr, data, HDRSIZE); 327 cdc36.decode (hdr, data, HDRSIZE);
291 328
292 clientid = hdr[0]; 329 clientid = hdr[2];
293 seqno = ((hdr[1] << 8) | hdr[2]) & SEQNO_MASK; 330 seqno = ((hdr[1] << 8) | hdr[0]) & SEQNO_MASK;
294} 331}
295 332
296///////////////////////////////////////////////////////////////////////////// 333/////////////////////////////////////////////////////////////////////////////
297 334
298struct byte_stream 335struct byte_stream
… …
324byte_stream::~byte_stream () 361byte_stream::~byte_stream ()
325{ 362{
326 delete data; 363 delete data;
327} 364}
328 365
366void
329void byte_stream::remove (int count) 367byte_stream::remove (int count)
330{ 368{
331 if (count > fill) 369 if (count > fill)
332 assert (count <= fill); 370 assert (count <= fill);
333 371
334 memmove (data, data + count, fill -= count); 372 memmove (data, data + count, fill -= count);
335} 373}
336 374
375bool
337bool byte_stream::put (u8 *data, unsigned int datalen) 376byte_stream::put (u8 *data, unsigned int datalen)
338{ 377{
339 if (maxsize - fill < datalen) 378 if (maxsize - fill < datalen)
340 return false; 379 return false;
341 380
342 memcpy (this->data + fill, data, datalen); fill += datalen; 381 memcpy (this->data + fill, data, datalen); fill += datalen;
343 382
344 return true; 383 return true;
345} 384}
346 385
386bool
347bool byte_stream::put (vpn_packet *pkt) 387byte_stream::put (vpn_packet *pkt)
348{ 388{
349 if (maxsize - fill < pkt->len + 2) 389 if (maxsize - fill < pkt->len + 2)
350 return false; 390 return false;
351 391
352 data [fill++] = pkt->len >> 8; 392 data [fill++] = pkt->len >> 8;
… …
408 448
409struct dns_cfg 449struct dns_cfg
410{ 450{
411 static int next_uid; 451 static int next_uid;
412 452
413 u8 id1, id2, id3, id4; 453 u8 chksum;
454 u8 rrtype;
455 u16 uid; // to make request unique
414 456
415 u8 version; 457 u8 version;
416 u8 flags; 458 u8 flags;
417 u8 rrtype; 459 u16 max_size;
460
461 u8 id1, id2, id3, id4;
462
463 u16 client;
418 u8 def_ttl; 464 u8 def_ttl;
465 u8 r0;
419 466
420 u16 client; 467 u8 syn_cdc; // cdc en/decoder for syn (A?) requests
421 u16 uid; // to make request unique 468 u8 hdr_cdc; // cdc en/decoder for regular request headers
469 u8 req_cdc; // cdc en/decoder for regular (ANY?) request data
470 u8 rep_cdc; // cdc en/decoder for regular (TXT) replies, 0 == 8 bit encoding
422 471
423 u16 max_size;
424 u8 seq_cdc;
425 u8 req_cdc;
426
427 u8 rep_cdc;
428 u8 r2, r3, r4; 472 u8 r1, r2, r3, r4;
429
430 u8 r5, r6, r7, r8;
431 473
432 void reset (int clientid); 474 void reset (int clientid);
433 bool valid (); 475 bool valid ();
476 u8 get_chksum ();
434}; 477};
435 478
436int dns_cfg::next_uid; 479int dns_cfg::next_uid;
437 480
481void
438void dns_cfg::reset (int clientid) 482dns_cfg::reset (int clientid)
439{ 483{
484 // this ID must result in some mixed-case characters in cdc26-encoding
440 id1 = 'G'; 485 id1 = 'G';
441 id2 = 'V'; 486 id2 = 'V';
442 id3 = 'P'; 487 id3 = 'P';
443 id4 = 'E'; 488 id4 = 'E';
444 489
445 version = 1; 490 version = 2;
446 491
447 rrtype = RR_TYPE_TXT; 492 rrtype = RR_TYPE_TXT;
448 flags = 0; 493 flags = 0;
449 def_ttl = 0; 494 def_ttl = 0;
450 seq_cdc = 26; 495 syn_cdc = 26;
451 req_cdc = 62; 496 hdr_cdc = 36;
497 req_cdc = conf.dns_case_preserving ? 62 : 36;
452 rep_cdc = 0; 498 rep_cdc = 0;
453 max_size = ntohs (MAX_PKT_SIZE); 499 max_size = htons (MAX_PKT_SIZE);
454 client = ntohs (clientid); 500 client = htons (clientid);
455 uid = next_uid++; 501 uid = ++next_uid;
456 502
457 r2 = r3 = r4 = 0; 503 r0 = r1 = r2 = r3 = r4 = 0;
458 r4 = r5 = r6 = r7 = 0;
459}
460 504
505 chksum = get_chksum ();
506}
507
508// simple but not trivial chksum
509u8
510dns_cfg::get_chksum ()
511{
512 unsigned int sum = 0xff00; // only 16 bits required
513
514 u8 old_chksum = chksum;
515 chksum = 0;
516
517 for (unsigned int i = 0; i < sizeof (*this); ++i)
518 sum += ((u8 *)this)[i] * (i + 1);
519
520 chksum = old_chksum;
521
522 return sum + (sum >> 8);
523}
524
525bool
461bool dns_cfg::valid () 526dns_cfg::valid ()
462{ 527{
528 // although the protocol itself allows for some configurability,
529 // only the following encoding/decoding settings are implemented.
463 return id1 == 'G' 530 return id1 == 'G'
464 && id2 == 'V' 531 && id2 == 'V'
465 && id3 == 'P' 532 && id3 == 'P'
466 && id4 == 'E' 533 && id4 == 'E'
534 && version == 2
467 && seq_cdc == 26 535 && syn_cdc == 26
468 && req_cdc == 62 536 && hdr_cdc == 36
537 && (req_cdc == 36 || req_cdc == 62)
469 && rep_cdc == 0 538 && rep_cdc == 0
470 && version == 1 539 && chksum == get_chksum ();
471 && max_size == ntohs (MAX_PKT_SIZE);
472} 540}
473 541
474struct dns_packet : net_packet 542struct dns_packet : net_packet
475{ 543{
476 u16 id; 544 u16 id;
… …
480 u8 data [MAXSIZE - 6 * 2]; 548 u8 data [MAXSIZE - 6 * 2];
481 549
482 int decode_label (char *data, int size, int &offs); 550 int decode_label (char *data, int size, int &offs);
483}; 551};
484 552
553int
485int dns_packet::decode_label (char *data, int size, int &offs) 554dns_packet::decode_label (char *data, int size, int &offs)
486{ 555{
487 char *orig = data; 556 char *orig = data;
488 557
489 memset (data, 0, size); 558 memset (data, 0, size);
490 559
… …
516 return data - orig; 585 return data - orig;
517} 586}
518 587
519///////////////////////////////////////////////////////////////////////////// 588/////////////////////////////////////////////////////////////////////////////
520 589
590static
591u16 next_id ()
592{
521static u16 dns_id = 0; // TODO: should be per-vpn 593 static u16 dns_id = 0; // TODO: should be per-vpn
522 594
523static u16 next_id () 595#if 1
524{
525 if (!dns_id) 596 if (!dns_id)
526 dns_id = time (0); 597 dns_id = time (0);
527 598
528 // the simplest lsfr with periodicity 65535 i could find 599 // the simplest lsfr with periodicity 65535 i could find
529 dns_id = (dns_id << 1) 600 dns_id = (dns_id << 1)
… …
531 ^ (dns_id >> 2) 602 ^ (dns_id >> 2)
532 ^ (dns_id >> 4) 603 ^ (dns_id >> 4)
533 ^ (dns_id >> 15)) & 1); 604 ^ (dns_id >> 15)) & 1);
534 605
535 return dns_id; 606 return dns_id;
607#else
608 dns_id++;//D
609
610 return htons (dns_id);
611#endif
536} 612}
537 613
538struct dns_rcv; 614struct dns_rcv;
539struct dns_snd; 615struct dns_snd;
540 616
… …
544 struct vpn *vpn; 620 struct vpn *vpn;
545 621
546 dns_cfg cfg; 622 dns_cfg cfg;
547 623
548 bool established; 624 bool established;
625 const basecoder *cdc;
549 626
550 tstamp last_received; 627 tstamp last_received;
551 tstamp last_sent; 628 tstamp last_sent;
552 double last_latency; 629 double min_latency;
553 double poll_interval, send_interval; 630 double poll_interval, send_interval;
554 631
555 vector<dns_rcv *> rcvpq; 632 vector<dns_rcv *> rcvpq;
556 633
557 byte_stream rcvdq; int rcvseq; 634 byte_stream rcvdq; int rcvseq; int repseq;
558 byte_stream snddq; int sndseq; 635 byte_stream snddq; int sndseq;
559 636
560 void time_cb (time_watcher &w); time_watcher tw; 637 inline void time_cb (ev::timer &w, int revents); ev::timer tw;
561 void receive_rep (dns_rcv *r); 638 void receive_rep (dns_rcv *r);
639
640 void reset (); // quite like tcp RST
641 void set_cfg (); // to be called after any cfg changes
562 642
563 dns_connection (connection *c); 643 dns_connection (connection *c);
564 ~dns_connection (); 644 ~dns_connection ();
565}; 645};
566 646
… …
584: dns (dns) 664: dns (dns)
585{ 665{
586 timeout = 0; 666 timeout = 0;
587 retry = 0; 667 retry = 0;
588 seqno = 0; 668 seqno = 0;
589 sent = NOW; 669 sent = ev_now ();
590 stdhdr = false; 670 stdhdr = false;
591 671
592 pkt = new dns_packet; 672 pkt = new dns_packet;
593 673
594 pkt->id = next_id (); 674 pkt->id = next_id ();
… …
597dns_snd::~dns_snd () 677dns_snd::~dns_snd ()
598{ 678{
599 delete pkt; 679 delete pkt;
600} 680}
601 681
682static void
602static void append_domain (dns_packet &pkt, int &offs, const char *domain) 683append_domain (dns_packet &pkt, int &offs, const char *domain)
603{ 684{
604 // add tunnel domain 685 // add tunnel domain
605 for (;;) 686 for (;;)
606 { 687 {
607 const char *end = strchr (domain, '.'); 688 const char *end = strchr (domain, '.');
… …
620 701
621 domain = end + 1; 702 domain = end + 1;
622 } 703 }
623} 704}
624 705
706void
625void dns_snd::gen_stream_req (int seqno, byte_stream &stream) 707dns_snd::gen_stream_req (int seqno, byte_stream &stream)
626{ 708{
627 stdhdr = true; 709 stdhdr = true;
628 this->seqno = seqno; 710 this->seqno = seqno;
629 711
630 timeout = NOW + INITIAL_TIMEOUT; 712 timeout = ev_now () + INITIAL_TIMEOUT;
631 713
632 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 714 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
633 pkt->qdcount = htons (1); 715 pkt->qdcount = htons (1);
634 716
635 int offs = 6*2; 717 int offs = 6*2;
… …
638 // so we need to have space for 2*MAX_DOMAIN_SIZE + header + extra 720 // so we need to have space for 2*MAX_DOMAIN_SIZE + header + extra
639 721
640 char enc[256], *encp = enc; 722 char enc[256], *encp = enc;
641 encode_header (enc, THISNODE->id, seqno); 723 encode_header (enc, THISNODE->id, seqno);
642 724
643 int datalen = cdc62.decode_len (dlen - (dlen + MAX_LBL_SIZE - 1) / MAX_LBL_SIZE - HDRSIZE); 725 int datalen = dns->cdc->decode_len (dlen - (dlen + MAX_LBL_SIZE - 1) / MAX_LBL_SIZE - HDRSIZE);
644 726
645 if (datalen > stream.size ()) 727 if (datalen > stream.size ())
646 datalen = stream.size (); 728 datalen = stream.size ();
647 729
648 int enclen = cdc62.encode (enc + HDRSIZE, stream.begin (), datalen) + HDRSIZE; 730 int enclen = dns->cdc->encode (enc + HDRSIZE, stream.begin (), datalen) + HDRSIZE;
649 stream.remove (datalen); 731 stream.remove (datalen);
650 732
651 while (enclen) 733 while (enclen)
652 { 734 {
653 int lbllen = enclen < MAX_LBL_SIZE ? enclen : MAX_LBL_SIZE; 735 int lbllen = enclen < MAX_LBL_SIZE ? enclen : MAX_LBL_SIZE;
… …
668 (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN; 750 (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN;
669 751
670 pkt->len = offs; 752 pkt->len = offs;
671} 753}
672 754
755void
673void dns_snd::gen_syn_req () 756dns_snd::gen_syn_req ()
674{ 757{
675 timeout = NOW + INITIAL_SYN_TIMEOUT; 758 timeout = ev_now () + INITIAL_SYN_TIMEOUT;
676 759
677 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 760 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
678 pkt->qdcount = htons (1); 761 pkt->qdcount = htons (1);
679 762
680 int offs = 6 * 2; 763 int offs = 6 * 2;
… …
719///////////////////////////////////////////////////////////////////////////// 802/////////////////////////////////////////////////////////////////////////////
720 803
721dns_connection::dns_connection (connection *c) 804dns_connection::dns_connection (connection *c)
722: c (c) 805: c (c)
723, rcvdq (MAX_BACKLOG * 2) 806, rcvdq (MAX_BACKLOG * 2)
724, snddq (MAX_BACKLOG * 2) 807, snddq (MAX_BACKLOG)
725, tw (this, &dns_connection::time_cb)
726{ 808{
809 tw.set<dns_connection, &dns_connection::time_cb> (this);
810
727 vpn = c->vpn; 811 vpn = c->vpn;
728 812
813 reset ();
814}
815
816dns_connection::~dns_connection ()
817{
818 reset ();
819}
820
821void
822dns_connection::reset ()
823{
824 while (!rcvpq.empty ())
825 {
826 delete rcvpq.back ();
827 rcvpq.pop_back ();
828 }
829
830 for (int i = vpn->dns_sndpq.size (); i--; )
831 if (vpn->dns_sndpq [i]->dns == this)
832 {
833 vpn->dns_sndpq [i] = vpn->dns_sndpq.back ();
834 vpn->dns_sndpq.pop_back ();
835 }
836
729 established = false; 837 established = false;
730 838
731 rcvseq = sndseq = 0; 839 rcvseq = repseq = sndseq = 0;
732 840
733 last_sent = last_received = 0; 841 last_sent = 0;
734 poll_interval = MIN_POLL_INTERVAL; 842 poll_interval = 0.5; // starting here
735 send_interval = 0.5; // starting rate 843 send_interval = 0.5; // starting rate
736 last_latency = INITIAL_TIMEOUT; 844 min_latency = INITIAL_TIMEOUT;
737} 845}
738 846
739dns_connection::~dns_connection () 847void
848dns_connection::set_cfg ()
740{ 849{
741 for (vector<dns_rcv *>::iterator i = rcvpq.begin (); 850 cdc = cfg.req_cdc == 36 ? &cdc36 : &cdc62;
742 i != rcvpq.end ();
743 ++i)
744 delete *i;
745} 851}
746 852
853void
747void dns_connection::receive_rep (dns_rcv *r) 854dns_connection::receive_rep (dns_rcv *r)
748{ 855{
749 if (r->datalen) 856 if (r->datalen)
750 { 857 poll_interval = max (poll_interval * (1. / 1.2), MIN_POLL_INTERVAL);
751 last_received = NOW;
752 tw.trigger ();
753
754 poll_interval = send_interval;
755 }
756 else 858 else
757 { 859 poll_interval = min (poll_interval * 1.1, MAX_POLL_INTERVAL);
758 poll_interval *= 1.5;
759 if (poll_interval > MAX_POLL_INTERVAL)
760 poll_interval = MAX_POLL_INTERVAL;
761 }
762 860
763 rcvpq.push_back (r); 861 rcvpq.push_back (r);
764 862
765 redo: 863 redo:
766 864
767 // find next packet 865 // find next packet
768 for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); ) 866 for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); )
769 if (SEQNO_EQ (rcvseq, (*i)->seqno)) 867 if (SEQNO_EQ (rcvseq, (*i)->seqno))
770 { 868 {
869 //printf ("seqno eq %x %x\n", rcvseq, (*i)->seqno);//D
771 // enter the packet into our input stream 870 // enter the packet into our input stream
772 r = *i; 871 r = *i;
773 872
774 // remove the oldest packet, look forward, as it's oldest first 873 // remove the oldest packet, look forward, as it's oldest first
775 for (vector<dns_rcv *>::iterator j = rcvpq.begin (); j != rcvpq.end (); ++j) 874 for (vector<dns_rcv *>::iterator j = rcvpq.begin (); j != rcvpq.end (); ++j)
776 if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW)) 875 if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW))
777 { 876 {
877 //printf ("seqno RR %x %x\n", (*j)->seqno, rcvseq - MAX_WINDOW);//D
778 delete *j; 878 delete *j;
779 rcvpq.erase (j); 879 rcvpq.erase (j);
780 break; 880 break;
781 } 881 }
782 882
783 rcvseq = (rcvseq + 1) & SEQNO_MASK; 883 rcvseq = (rcvseq + 1) & SEQNO_MASK;
784 884
785 if (!rcvdq.put (r->data, r->datalen)) 885 if (!rcvdq.put (r->data, r->datalen))
786 { 886 {
887 // MUST never overflow, can be caused by data corruption, TODO
787 slog (L_ERR, "DNS: !rcvdq.put (r->data, r->datalen)"); 888 slog (L_CRIT, "DNS: !rcvdq.put (r->data, r->datalen)");
788 abort (); // MUST never overflow, can be caused by data corruption, TODO 889 reset ();
890 return;
789 } 891 }
790 892
791 while (vpn_packet *pkt = rcvdq.get ()) 893 while (vpn_packet *pkt = rcvdq.get ())
792 { 894 {
793 sockinfo si; 895 sockinfo si;
794 si.host = 0x01010101; si.port = htons (c->conf->id); si.prot = PROT_DNSv4; 896 si.host = htonl (c->conf->id); si.port = 0; si.prot = PROT_DNSv4;
795 897
796 vpn->recv_vpn_packet (pkt, si); 898 vpn->recv_vpn_packet (pkt, si);
797
798 delete pkt; 899 delete pkt;
799 } 900 }
800 901
801 // check for further packets 902 // check for further packets
802 goto redo; 903 goto redo;
… …
845 { 946 {
846 // correct class, domain: parse 947 // correct class, domain: parse
847 int client, seqno; 948 int client, seqno;
848 decode_header (qname, client, seqno); 949 decode_header (qname, client, seqno);
849 950
850 u8 data[MAXSIZE];
851 int datalen = cdc62.decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE));
852
853 if (0 < client && client <= conns.size ()) 951 if (0 < client && client <= conns.size ())
854 { 952 {
855 connection *c = conns [client - 1]; 953 connection *c = conns [client - 1];
856 dns_connection *dns = c->dns; 954 dns_connection *dns = c->dns;
857 dns_rcv *rcv; 955 dns_rcv *rcv;
858 bool in_seq;
859 956
860 if (dns) 957 if (dns)
861 { 958 {
959 u8 data[MAXSIZE];
960 int datalen = dns->cdc->decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE));
961
862 for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); ) 962 for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); )
863 if (SEQNO_EQ ((*i)->seqno, seqno)) 963 if (SEQNO_EQ ((*i)->seqno, seqno))
864 { 964 {
865 // already seen that request: simply reply with the cached reply 965 // already seen that request: simply reply with the cached reply
866 dns_rcv *r = *i; 966 dns_rcv *r = *i;
… …
874 memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len); 974 memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len);
875 975
876 goto duplicate_request; 976 goto duplicate_request;
877 } 977 }
878 978
879 in_seq = dns->rcvseq == seqno;
880
881 // new packet, queue 979 // new packet, queue
882 rcv = new dns_rcv (seqno, data, datalen); 980 rcv = new dns_rcv (seqno, data, datalen);
883 dns->receive_rep (rcv); 981 dns->receive_rep (rcv);
884 } 982 }
885 983
… …
892 pkt [offs++] = 0; pkt [offs++] = 0; 990 pkt [offs++] = 0; pkt [offs++] = 0;
893 pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL 991 pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL
894 992
895 int rdlen_offs = offs += 2; 993 int rdlen_offs = offs += 2;
896 994
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) 995 if (dns)
902 { 996 {
997 int dlen = ntohs (dns->cfg.max_size) - offs;
998
999 // bind doesn't compress well, so reduce further by one label length
1000 dlen -= qlen;
1001
903 // only put data into in-order sequence packets, if 1002 // only put data into in-order sequence packets, if
904 // we receive out-of-order packets we generate empty 1003 // we receive out-of-order packets we generate empty
905 // replies 1004 // replies
906 while (dlen > 1 && !dns->snddq.empty () && in_seq) 1005 //printf ("%d - %d & %x (=%d) < %d\n", seqno, dns->repseq, SEQNO_MASK, (seqno - dns->repseq) & SEQNO_MASK, MAX_WINDOW);//D
1006 if (((seqno - dns->repseq) & SEQNO_MASK) <= MAX_WINDOW)
907 { 1007 {
1008 dns->repseq = seqno;
1009
1010 while (dlen > 1 && !dns->snddq.empty ())
1011 {
908 int txtlen = dlen <= 255 ? dlen - 1 : 255; 1012 int txtlen = dlen <= 255 ? dlen - 1 : 255;
909 1013
910 if (txtlen > dns->snddq.size ()) 1014 if (txtlen > dns->snddq.size ())
911 txtlen = dns->snddq.size (); 1015 txtlen = dns->snddq.size ();
912 1016
913 pkt[offs++] = txtlen; 1017 pkt[offs++] = txtlen;
914 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen); 1018 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
915 offs += txtlen; 1019 offs += txtlen;
916 dns->snddq.remove (txtlen); 1020 dns->snddq.remove (txtlen);
917 1021
918 dlen -= txtlen + 1; 1022 dlen -= txtlen + 1;
1023 }
919 } 1024 }
920 1025
921 // avoid empty TXT rdata 1026 // avoid completely empty TXT rdata
922 if (offs == rdlen_offs) 1027 if (offs == rdlen_offs)
923 pkt[offs++] = 0; 1028 pkt[offs++] = 0;
924 1029
925 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ()); 1030 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
926 } 1031 }
… …
962 pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class 1067 pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
963 pkt [offs++] = 0; pkt [offs++] = 0; 1068 pkt [offs++] = 0; pkt [offs++] = 0;
964 pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL 1069 pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL
965 pkt [offs++] = 0; pkt [offs++] = 4; // rdlength 1070 pkt [offs++] = 0; pkt [offs++] = 4; // rdlength
966 1071
967 slog (L_INFO, _("DNS: client %d connects"), client);
968
969 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3; 1072 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
970 pkt [offs++] = CMD_IP_REJ; 1073 pkt [offs++] = CMD_IP_REJ;
971 1074
972 if (0 < client && client <= conns.size ()) 1075 if (0 < client && client <= conns.size ())
973 { 1076 {
974 connection *c = conns [client - 1]; 1077 connection *c = conns [client - 1];
975 1078
976 if (cfg.valid ()) 1079 if (cfg.valid ())
977 { 1080 {
978 pkt [offs - 1] = CMD_IP_SYN; 1081 slog (L_INFO, _("DNS: client %d connects (version %d, req_cdc %d)"), client, cfg.version, cfg.req_cdc);
1082
1083 // check for any encoding mismatches - hints at a case problem
1084 char qname2 [MAX_ENC_LEN];
1085 cdc26.encode (qname2, (u8 *)&cfg, sizeof (dns_cfg));
979 1086
980 delete c->dns; 1087 delete c->dns;
1088
1089 pkt [offs - 1] = memcmp (qname, qname2, cdc26.encode_len (sizeof (dns_cfg)))
1090 ? CMD_IP_CSE : CMD_IP_SYN;
1091
981 c->dns = new dns_connection (c); 1092 c->dns = new dns_connection (c);
982 c->dns->cfg = cfg; 1093 c->dns->cfg = cfg;
1094 c->dns->set_cfg ();
983 } 1095 }
984 } 1096 }
985 } 1097 }
986 } 1098 }
987 1099
… …
1006 { 1118 {
1007 dns_connection *dns = (*i)->dns; 1119 dns_connection *dns = (*i)->dns;
1008 connection *c = dns->c; 1120 connection *c = dns->c;
1009 int seqno = (*i)->seqno; 1121 int seqno = (*i)->seqno;
1010 u8 data[MAXSIZE], *datap = data; 1122 u8 data[MAXSIZE], *datap = data;
1123 //printf ("rcv pkt %x\n", seqno);//D
1011 1124
1012 if ((*i)->retry) 1125 if ((*i)->retry)
1013 { 1126 {
1014 dns->send_interval *= 1.01; 1127 dns->send_interval *= 1.01;
1015 if (dns->send_interval > MAX_SEND_INTERVAL) 1128 if (dns->send_interval > MAX_SEND_INTERVAL)
1016 dns->send_interval = MAX_SEND_INTERVAL; 1129 dns->send_interval = MAX_SEND_INTERVAL;
1017 } 1130 }
1018 else 1131 else
1019 { 1132 {
1020#if 1 1133#if 0
1021 dns->send_interval *= 0.999; 1134 dns->send_interval *= 0.999;
1022#endif 1135#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 1136 // the latency surely puts an upper bound on
1027 // the minimum send interval 1137 // the minimum send interval
1028 double latency = NOW - (*i)->sent; 1138 double latency = ev_now () - (*i)->sent;
1139
1140 if (latency < dns->min_latency)
1029 dns->last_latency = latency; 1141 dns->min_latency = latency;
1030 1142
1031 if (dns->send_interval > latency) 1143 if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor)
1144 dns->send_interval = dns->min_latency * conf.dns_overlap_factor;
1145
1146 if (dns->send_interval < conf.dns_send_interval)
1032 dns->send_interval = latency; 1147 dns->send_interval = conf.dns_send_interval;
1033 } 1148 }
1034 1149
1035 delete *i; 1150 delete *i;
1036 dns_sndpq.erase (i); 1151 dns_sndpq.erase (i);
1037 1152
… …
1055 ttl |= pkt [offs++] << 16; 1170 ttl |= pkt [offs++] << 16;
1056 ttl |= pkt [offs++] << 8; 1171 ttl |= pkt [offs++] << 8;
1057 ttl |= pkt [offs++]; 1172 ttl |= pkt [offs++];
1058 u16 rdlen = pkt [offs++] << 8; rdlen |= pkt [offs++]; 1173 u16 rdlen = pkt [offs++] << 8; rdlen |= pkt [offs++];
1059 1174
1060 if (qtype == RR_TYPE_NULL || qtype == RR_TYPE_TXT) 1175 if (qtype == RR_TYPE_NULL || qtype == RR_TYPE_TXT || qtype == dns->cfg.rrtype)
1061 { 1176 {
1062 if (rdlen <= MAXSIZE - offs) 1177 if (rdlen <= MAXSIZE - offs)
1063 { 1178 {
1064 // decode bytes, finally 1179 // decode bytes, finally
1065 1180
… …
1091 { 1206 {
1092 slog (L_TRACE, _("DNS: got tunnel meta command %02x"), ip [3]); 1207 slog (L_TRACE, _("DNS: got tunnel meta command %02x"), ip [3]);
1093 1208
1094 if (ip [3] == CMD_IP_RST) 1209 if (ip [3] == CMD_IP_RST)
1095 { 1210 {
1096 slog (L_DEBUG, _("DNS: got tunnel RST request")); 1211 slog (L_DEBUG, _("DNS: got tunnel RST request."));
1097 1212
1098 delete dns; c->dns = 0; 1213 dns->reset ();
1099
1100 return; 1214 return;
1101 } 1215 }
1102 else if (ip [3] == CMD_IP_SYN) 1216 else if (ip [3] == CMD_IP_SYN)
1103 { 1217 {
1104 slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us.")); 1218 slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us."));
1105 dns->established = true; 1219 dns->established = true;
1106 } 1220 }
1221 else if (ip [3] == CMD_IP_CSE)
1222 {
1223 if (conf.dns_case_preserving)
1224 {
1225 slog (L_INFO, _("DNS: got tunnel CSE reply, globally downgrading to case-insensitive protocol."));
1226 conf.dns_case_preserving = false;
1227 dns->reset ();
1228 return;
1229 }
1230 else
1231 {
1232 slog (L_DEBUG, _("DNS: got tunnel CSE reply, server likes us."));
1233 dns->established = true;
1234 }
1235 }
1107 else if (ip [3] == CMD_IP_REJ) 1236 else if (ip [3] == CMD_IP_REJ)
1108 { 1237 {
1109 slog (L_DEBUG, _("DNS: got tunnel REJ reply, server does not like us, aborting.")); 1238 slog (L_ERR, _("DNS: got tunnel REJ reply, server does not like us."));
1110 abort (); 1239 dns->tw.start (60.);
1111 } 1240 }
1112 else 1241 else
1242 {
1113 slog (L_INFO, _("DNS: got unknown meta command %02x"), ip [3]); 1243 slog (L_INFO, _("DNS: got unknown meta command %02x"), ip [3]);
1244 dns->tw.start (60.);
1245 }
1114 } 1246 }
1115 else 1247 else
1116 slog (L_INFO, _("DNS: got spurious a record %d.%d.%d.%d"), 1248 slog (L_INFO, _("DNS: got spurious a record %d.%d.%d.%d"),
1117 ip [0], ip [1], ip [2], ip [3]); 1249 ip [0], ip [1], ip [2], ip [3]);
1118 1250
… …
1142 break; 1274 break;
1143 } 1275 }
1144} 1276}
1145 1277
1146void 1278void
1147vpn::dnsv4_ev (io_watcher &w, short revents) 1279vpn::dnsv4_ev (ev::io &w, int revents)
1148{ 1280{
1149 if (revents & EVENT_READ) 1281 if (revents & EV_READ)
1150 { 1282 {
1151 dns_packet *pkt = new dns_packet; 1283 dns_packet *pkt = new dns_packet;
1152 struct sockaddr_in sa; 1284 struct sockaddr_in sa;
1153 socklen_t sa_len = sizeof (sa); 1285 socklen_t sa_len = sizeof (sa);
1154 1286
… …
1170} 1302}
1171 1303
1172bool 1304bool
1173vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) 1305vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
1174{ 1306{
1175 int client = ntohs (si.port); 1307 int client = ntohl (si.host);
1176 1308
1177 assert (0 < client && client <= conns.size ()); 1309 assert (0 < client && client <= conns.size ());
1178 1310
1179 connection *c = conns [client - 1]; 1311 connection *c = conns [client - 1];
1180 1312
1181 if (!c->dns) 1313 if (!c->dns)
1182 c->dns = new dns_connection (c); 1314 c->dns = new dns_connection (c);
1183 1315
1184 if (!c->dns->snddq.put (pkt)) 1316 if (c->dns->snddq.put (pkt))
1185 return false; 1317 {
1318 min_it (c->dns->poll_interval, 0.25);
1319 c->dns->tw ();
1320 }
1186 1321
1187 c->dns->tw.trigger (); 1322 // always return true even if the buffer overflows
1188
1189 return true; 1323 return true;
1190} 1324}
1191 1325
1192void 1326void
1193connection::dnsv4_reset_connection () 1327dns_connection::time_cb (ev::timer &w, int revents)
1194{
1195 //delete dns; dns = 0; //TODO
1196}
1197
1198#define NEXT(w) do { if (next > (w)) next = w; } while (0)
1199
1200void
1201dns_connection::time_cb (time_watcher &w)
1202{ 1328{
1203 // servers have to be polled 1329 // servers have to be polled
1204 if (THISNODE->dns_port) 1330 if (THISNODE->dns_port)
1205 return; 1331 return;
1206 1332
1207 // check for timeouts and (re)transmit 1333 // check for timeouts and (re)transmit
1208 tstamp next = NOW + poll_interval; 1334 tstamp next = 86400 * 365;
1209 dns_snd *send = 0; 1335 dns_snd *send = 0;
1210 1336
1211 for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin (); 1337 for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin ();
1212 i != vpn->dns_sndpq.end (); 1338 i != vpn->dns_sndpq.end ();
1213 ++i) 1339 ++i)
1214 { 1340 {
1215 dns_snd *r = *i; 1341 dns_snd *r = *i;
1216 1342
1217 if (r->timeout <= NOW) 1343 if (r->timeout <= ev_now ())
1218 { 1344 {
1219 if (!send) 1345 if (!send)
1220 { 1346 {
1221 send = r; 1347 send = r;
1222 1348
1223 r->retry++; 1349 r->retry++;
1224 r->timeout = NOW + (r->retry * last_latency * 8.); 1350 r->timeout = ev_now () + r->retry * min_latency * conf.dns_timeout_factor;
1351 //printf ("RETRY %x (%d, %f)\n", r->seqno, r->retry, r->timeout - ev_now ());//D
1225 1352
1226 // the following code changes the query section a bit, forcing 1353 // the following code changes the query section a bit, forcing
1227 // the forwarder to generate a new request 1354 // the forwarder to generate a new request
1228 if (r->stdhdr) 1355 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); 1356 encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry);
1232 }
1233 } 1357 }
1234 } 1358 }
1235 else 1359 else
1236 NEXT (r->timeout); 1360 min_it (next, r->timeout - ev_now ());
1237 }
1238
1239 if (last_sent + send_interval <= NOW)
1240 { 1361 }
1362
1241 if (!send) 1363 if (!send)
1364 {
1365 // generate a new packet, if wise
1366
1367 if (!established)
1242 { 1368 {
1243 // generate a new packet, if wise 1369 if (vpn->dns_sndpq.empty ())
1244
1245 if (!established)
1246 { 1370 {
1247 if (vpn->dns_sndpq.empty ())
1248 {
1249 send = new dns_snd (this); 1371 send = new dns_snd (this);
1250 1372
1251 cfg.reset (THISNODE->id); 1373 cfg.reset (THISNODE->id);
1374 set_cfg ();
1252 send->gen_syn_req (); 1375 send->gen_syn_req ();
1253 }
1254 } 1376 }
1255 else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING 1377 }
1378 else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding
1256 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) 1379 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
1380 {
1381 if (last_sent + send_interval <= ev_now ())
1257 { 1382 {
1258 //printf ("sending data request etc.\n"); //D 1383 //printf ("sending data request etc.\n"); //D
1259 if (!snddq.empty ()) 1384 if (!snddq.empty ())
1260 {
1261 poll_interval = send_interval;
1262 NEXT (NOW + send_interval); 1385 min_it (next, send_interval);
1263 }
1264 1386
1265 send = new dns_snd (this); 1387 send = new dns_snd (this);
1266 send->gen_stream_req (sndseq, snddq); 1388 send->gen_stream_req (sndseq, snddq);
1267 send->timeout = NOW + last_latency * 8.; 1389 send->timeout = ev_now () + min_latency * conf.dns_timeout_factor;
1390 //printf ("SEND %x (%f)\n", send->seqno, send->timeout - ev_now (), min_latency, conf.dns_timeout_factor);//D
1268 1391
1269 sndseq = (sndseq + 1) & SEQNO_MASK; 1392 sndseq = (sndseq + 1) & SEQNO_MASK;
1270 } 1393 }
1271 1394 else
1272 if (send) 1395 min_it (next, last_sent + send_interval - ev_now ());
1273 vpn->dns_sndpq.push_back (send);
1274 } 1396 }
1275 1397
1276 if (send) 1398 if (send)
1277 { 1399 vpn->dns_sndpq.push_back (send);
1278 last_sent = NOW; 1400 }
1401
1402 if (send)
1403 {
1404 last_sent = ev_now ();
1279 sendto (vpn->dnsv4_fd, 1405 sendto (vpn->dnsv4_fd,
1280 send->pkt->at (0), send->pkt->len, 0, 1406 send->pkt->at (0), send->pkt->len, 0,
1281 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); 1407 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
1282 }
1283 } 1408 }
1284 else
1285 NEXT (last_sent + send_interval);
1286 1409
1410 min_it (next, last_sent + max (poll_interval, send_interval) - ev_now ());
1411
1287 slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d)", 1412 slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)",
1288 poll_interval, send_interval, next - NOW, 1413 poll_interval, send_interval, next - ev_now (),
1289 vpn->dns_sndpq.size (), snddq.size ()); 1414 vpn->dns_sndpq.size (), snddq.size (),
1290 1415 rcvpq.size ());
1291 // TODO: no idea when this happens, but when next < NOW, we have a problem
1292 if (next < NOW + 0.0001)
1293 next = NOW + 0.1;
1294 1416
1295 w.start (next); 1417 w.start (next);
1296} 1418}
1297 1419
1298#endif 1420#endif

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