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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 1.54 by root, Tue Oct 18 11:07:28 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
64#define MIN_POLL_INTERVAL 0.025 // poll at most this often when no data received
49#define MAX_POLL_INTERVAL 5. // 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
50#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 5. // 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 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;
… …
357 return true; 397 return true;
358} 398}
359 399
360vpn_packet *byte_stream::get () 400vpn_packet *byte_stream::get ()
361{ 401{
402 if (fill < 2)
403 return 0;
404
362 unsigned int len; 405 unsigned int len;
363 406
364 for (;;) 407 for (;;)
365 { 408 {
366 len = (data [0] << 8) | data [1]; 409 len = (data [0] << 8) | data [1];
367 410
368 if (len <= MAXSIZE || fill < 2) 411 if (len <= MAXSIZE)
369 break; 412 break;
370 413
371 // TODO: handle this better than skipping, e.g. by reset 414 // TODO: handle this better than skipping, e.g. by reset
372 slog (L_DEBUG, _("DNS: corrupted packet stream skipping a byte...")); 415 slog (L_DEBUG, _("DNS: corrupted packet (%02x %02x) stream skipping a byte..."), data [0], data [1]);
373 remove (1); 416 remove (1);
374 } 417 }
375 418
376 if (fill < len + 2) 419 if (fill < len + 2)
377 return 0; 420 return 0;
… …
408 451
409struct dns_cfg 452struct dns_cfg
410{ 453{
411 static int next_uid; 454 static int next_uid;
412 455
413 u8 id1, id2, id3, id4; 456 u8 chksum;
457 u8 rrtype;
458 u16 uid; // to make request unique
414 459
415 u8 version; 460 u8 version;
416 u8 flags; 461 u8 flags;
417 u8 rrtype; 462 u16 max_size;
463
464 u8 id1, id2, id3, id4;
465
466 u16 client;
418 u8 def_ttl; 467 u8 def_ttl;
468 u8 r0;
419 469
420 u16 client; 470 u8 syn_cdc; // cdc en/decoder for syn (A?) requests
421 u16 uid; // to make request unique 471 u8 hdr_cdc; // cdc en/decoder for regular request headers
472 u8 req_cdc; // cdc en/decoder for regular (ANY?) request data
473 u8 rep_cdc; // cdc en/decoder for regular (TXT) replies, 0 == 8 bit encoding
422 474
423 u16 max_size;
424 u8 seq_cdc;
425 u8 req_cdc;
426
427 u8 rep_cdc;
428 u8 delay; // time in 0.01s units that the server may delay replying packets
429 u8 r3, r4;
430
431 u8 r5, r6, r7, r8; 475 u8 r1, r2, r3, r4;
432 476
433 void reset (int clientid); 477 void reset (int clientid);
434 bool valid (); 478 bool valid ();
479 u8 get_chksum ();
435}; 480};
436 481
437int dns_cfg::next_uid; 482int dns_cfg::next_uid;
438 483
484void
439void dns_cfg::reset (int clientid) 485dns_cfg::reset (int clientid)
440{ 486{
487 // this ID must result in some mixed-case characters in cdc26-encoding
441 id1 = 'G'; 488 id1 = 'G';
442 id2 = 'V'; 489 id2 = 'V';
443 id3 = 'P'; 490 id3 = 'P';
444 id4 = 'E'; 491 id4 = 'E';
445 492
446 version = 1; 493 version = 2;
447 494
448 rrtype = RR_TYPE_TXT; 495 rrtype = RR_TYPE_TXT;
449 flags = 0; 496 flags = 0;
450 def_ttl = 0; 497 def_ttl = 0;
451 seq_cdc = 26; 498 syn_cdc = 26;
452 req_cdc = 62; 499 hdr_cdc = 36;
500 req_cdc = conf.dns_case_preserving ? 62 : 36;
453 rep_cdc = 0; 501 rep_cdc = 0;
454 max_size = htons (MAX_PKT_SIZE); 502 max_size = htons (MAX_PKT_SIZE);
455 client = htons (clientid); 503 client = htons (clientid);
456 uid = next_uid++; 504 uid = ++next_uid;
457 delay = 0;
458 505
459 r3 = r4 = 0; 506 r0 = r1 = r2 = r3 = r4 = 0;
460 r4 = r5 = r6 = r7 = 0;
461}
462 507
508 chksum = get_chksum ();
509}
510
511// simple but not trivial chksum
512u8
513dns_cfg::get_chksum ()
514{
515 unsigned int sum = 0xff00; // only 16 bits required
516
517 u8 old_chksum = chksum;
518 chksum = 0;
519
520 for (unsigned int i = 0; i < sizeof (*this); ++i)
521 sum += ((u8 *)this)[i] * (i + 1);
522
523 chksum = old_chksum;
524
525 return sum + (sum >> 8);
526}
527
528bool
463bool dns_cfg::valid () 529dns_cfg::valid ()
464{ 530{
531 // although the protocol itself allows for some configurability,
532 // only the following encoding/decoding settings are implemented.
465 return id1 == 'G' 533 return id1 == 'G'
466 && id2 == 'V' 534 && id2 == 'V'
467 && id3 == 'P' 535 && id3 == 'P'
468 && id4 == 'E' 536 && id4 == 'E'
537 && version == 2
469 && seq_cdc == 26 538 && syn_cdc == 26
470 && req_cdc == 62 539 && hdr_cdc == 36
540 && (req_cdc == 36 || req_cdc == 62)
471 && rep_cdc == 0 541 && rep_cdc == 0
472 && version == 1; 542 && chksum == get_chksum ();
473} 543}
474 544
475struct dns_packet : net_packet 545struct dns_packet : net_packet
476{ 546{
477 u16 id; 547 u16 id;
… …
481 u8 data [MAXSIZE - 6 * 2]; 551 u8 data [MAXSIZE - 6 * 2];
482 552
483 int decode_label (char *data, int size, int &offs); 553 int decode_label (char *data, int size, int &offs);
484}; 554};
485 555
556int
486int dns_packet::decode_label (char *data, int size, int &offs) 557dns_packet::decode_label (char *data, int size, int &offs)
487{ 558{
488 char *orig = data; 559 char *orig = data;
489 560
490 memset (data, 0, size); 561 memset (data, 0, size);
491 562
… …
517 return data - orig; 588 return data - orig;
518} 589}
519 590
520///////////////////////////////////////////////////////////////////////////// 591/////////////////////////////////////////////////////////////////////////////
521 592
593static
594u16 next_id ()
595{
522static u16 dns_id = 0; // TODO: should be per-vpn 596 static u16 dns_id = 0; // TODO: should be per-vpn
523 597
524static u16 next_id () 598#if 1
525{
526 if (!dns_id) 599 if (!dns_id)
527 dns_id = time (0); 600 dns_id = time (0);
528 601
529 // the simplest lsfr with periodicity 65535 i could find 602 // the simplest lsfr with periodicity 65535 i could find
530 dns_id = (dns_id << 1) 603 dns_id = (dns_id << 1)
… …
532 ^ (dns_id >> 2) 605 ^ (dns_id >> 2)
533 ^ (dns_id >> 4) 606 ^ (dns_id >> 4)
534 ^ (dns_id >> 15)) & 1); 607 ^ (dns_id >> 15)) & 1);
535 608
536 return dns_id; 609 return dns_id;
610#else
611 dns_id++;//D
612
613 return htons (dns_id);
614#endif
537} 615}
538 616
539struct dns_rcv; 617struct dns_rcv;
540struct dns_snd; 618struct dns_snd;
541 619
… …
545 struct vpn *vpn; 623 struct vpn *vpn;
546 624
547 dns_cfg cfg; 625 dns_cfg cfg;
548 626
549 bool established; 627 bool established;
628 const basecoder *cdc;
550 629
551 tstamp last_received; 630 tstamp last_received;
552 tstamp last_sent; 631 tstamp last_sent;
553 double min_latency; 632 double min_latency;
554 double poll_interval, send_interval; 633 double poll_interval, send_interval;
555 634
556 vector<dns_rcv *> rcvpq; 635 vector<dns_rcv *> rcvpq;
557 636
558 byte_stream rcvdq; int rcvseq; 637 byte_stream rcvdq; int rcvseq; int repseq;
559 byte_stream snddq; int sndseq; 638 byte_stream snddq; int sndseq;
560 639
561 void time_cb (time_watcher &w); time_watcher tw; 640 inline void time_cb (ev::timer &w, int revents); ev::timer tw;
562 void receive_rep (dns_rcv *r); 641 void receive_rep (dns_rcv *r);
642
643 void reset (); // quite like tcp RST
644 void set_cfg (); // to be called after any cfg changes
563 645
564 dns_connection (connection *c); 646 dns_connection (connection *c);
565 ~dns_connection (); 647 ~dns_connection ();
566}; 648};
567 649
… …
585: dns (dns) 667: dns (dns)
586{ 668{
587 timeout = 0; 669 timeout = 0;
588 retry = 0; 670 retry = 0;
589 seqno = 0; 671 seqno = 0;
590 sent = NOW; 672 sent = ev_now ();
591 stdhdr = false; 673 stdhdr = false;
592 674
593 pkt = new dns_packet; 675 pkt = new dns_packet;
594 676
595 pkt->id = next_id (); 677 pkt->id = next_id ();
… …
598dns_snd::~dns_snd () 680dns_snd::~dns_snd ()
599{ 681{
600 delete pkt; 682 delete pkt;
601} 683}
602 684
685static void
603static void append_domain (dns_packet &pkt, int &offs, const char *domain) 686append_domain (dns_packet &pkt, int &offs, const char *domain)
604{ 687{
605 // add tunnel domain 688 // add tunnel domain
606 for (;;) 689 for (;;)
607 { 690 {
608 const char *end = strchr (domain, '.'); 691 const char *end = strchr (domain, '.');
… …
621 704
622 domain = end + 1; 705 domain = end + 1;
623 } 706 }
624} 707}
625 708
709void
626void dns_snd::gen_stream_req (int seqno, byte_stream &stream) 710dns_snd::gen_stream_req (int seqno, byte_stream &stream)
627{ 711{
628 stdhdr = true; 712 stdhdr = true;
629 this->seqno = seqno; 713 this->seqno = seqno;
630 714
631 timeout = NOW + INITIAL_TIMEOUT; 715 timeout = ev_now () + INITIAL_TIMEOUT;
632 716
633 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 717 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
634 pkt->qdcount = htons (1); 718 pkt->qdcount = htons (1);
635 719
636 int offs = 6*2; 720 int offs = 6*2;
… …
639 // so we need to have space for 2*MAX_DOMAIN_SIZE + header + extra 723 // so we need to have space for 2*MAX_DOMAIN_SIZE + header + extra
640 724
641 char enc[256], *encp = enc; 725 char enc[256], *encp = enc;
642 encode_header (enc, THISNODE->id, seqno); 726 encode_header (enc, THISNODE->id, seqno);
643 727
644 int datalen = cdc62.decode_len (dlen - (dlen + MAX_LBL_SIZE - 1) / MAX_LBL_SIZE - HDRSIZE); 728 int datalen = dns->cdc->decode_len (dlen - (dlen + MAX_LBL_SIZE - 1) / MAX_LBL_SIZE - HDRSIZE);
645 729
646 if (datalen > stream.size ()) 730 if (datalen > stream.size ())
647 datalen = stream.size (); 731 datalen = stream.size ();
648 732
649 int enclen = cdc62.encode (enc + HDRSIZE, stream.begin (), datalen) + HDRSIZE; 733 int enclen = dns->cdc->encode (enc + HDRSIZE, stream.begin (), datalen) + HDRSIZE;
650 stream.remove (datalen); 734 stream.remove (datalen);
651 735
652 while (enclen) 736 while (enclen)
653 { 737 {
654 int lbllen = enclen < MAX_LBL_SIZE ? enclen : MAX_LBL_SIZE; 738 int lbllen = enclen < MAX_LBL_SIZE ? enclen : MAX_LBL_SIZE;
… …
669 (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN; 753 (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN;
670 754
671 pkt->len = offs; 755 pkt->len = offs;
672} 756}
673 757
758void
674void dns_snd::gen_syn_req () 759dns_snd::gen_syn_req ()
675{ 760{
676 timeout = NOW + INITIAL_SYN_TIMEOUT; 761 timeout = ev_now () + INITIAL_SYN_TIMEOUT;
677 762
678 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 763 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
679 pkt->qdcount = htons (1); 764 pkt->qdcount = htons (1);
680 765
681 int offs = 6 * 2; 766 int offs = 6 * 2;
… …
720///////////////////////////////////////////////////////////////////////////// 805/////////////////////////////////////////////////////////////////////////////
721 806
722dns_connection::dns_connection (connection *c) 807dns_connection::dns_connection (connection *c)
723: c (c) 808: c (c)
724, rcvdq (MAX_BACKLOG * 2) 809, rcvdq (MAX_BACKLOG * 2)
725, snddq (MAX_BACKLOG * 2) 810, snddq (MAX_BACKLOG)
726, tw (this, &dns_connection::time_cb)
727{ 811{
812 tw.set<dns_connection, &dns_connection::time_cb> (this);
813
728 vpn = c->vpn; 814 vpn = c->vpn;
729 815
816 reset ();
817}
818
819dns_connection::~dns_connection ()
820{
821 reset ();
822}
823
824void
825dns_connection::reset ()
826{
827 while (!rcvpq.empty ())
828 {
829 delete rcvpq.back ();
830 rcvpq.pop_back ();
831 }
832
833 for (int i = vpn->dns_sndpq.size (); i--; )
834 if (vpn->dns_sndpq [i]->dns == this)
835 {
836 vpn->dns_sndpq [i] = vpn->dns_sndpq.back ();
837 vpn->dns_sndpq.pop_back ();
838 }
839
730 established = false; 840 established = false;
731 841
732 rcvseq = sndseq = 0; 842 rcvseq = repseq = sndseq = 0;
733 843
734 last_sent = last_received = 0; 844 last_sent = 0;
735 poll_interval = 0.5; // starting here 845 poll_interval = 0.5; // starting here
736 send_interval = 0.5; // starting rate 846 send_interval = 0.5; // starting rate
737 min_latency = INITIAL_TIMEOUT; 847 min_latency = INITIAL_TIMEOUT;
738} 848}
739 849
740dns_connection::~dns_connection () 850void
851dns_connection::set_cfg ()
741{ 852{
742 for (vector<dns_rcv *>::iterator i = rcvpq.begin (); 853 cdc = cfg.req_cdc == 36 ? &cdc36 : &cdc62;
743 i != rcvpq.end ();
744 ++i)
745 delete *i;
746} 854}
747 855
856void
748void dns_connection::receive_rep (dns_rcv *r) 857dns_connection::receive_rep (dns_rcv *r)
749{ 858{
750 if (r->datalen) 859 if (r->datalen)
751 { 860 poll_interval = max (poll_interval * (1. / 1.2), MIN_POLL_INTERVAL);
752 last_received = NOW;
753 tw.trigger ();
754
755 poll_interval = send_interval;
756 }
757 else 861 else
758 { 862 poll_interval = min (poll_interval * 1.1, MAX_POLL_INTERVAL);
759 poll_interval *= 1.5;
760
761 if (poll_interval > MAX_POLL_INTERVAL)
762 poll_interval = MAX_POLL_INTERVAL;
763 }
764 863
765 rcvpq.push_back (r); 864 rcvpq.push_back (r);
766 865
767 redo: 866 redo:
768 867
769 // find next packet 868 // find next packet
770 for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); ) 869 for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); )
771 if (SEQNO_EQ (rcvseq, (*i)->seqno)) 870 if (SEQNO_EQ (rcvseq, (*i)->seqno))
772 { 871 {
872 //printf ("seqno eq %x %x\n", rcvseq, (*i)->seqno);//D
773 // enter the packet into our input stream 873 // enter the packet into our input stream
774 r = *i; 874 r = *i;
775 875
776 // remove the oldest packet, look forward, as it's oldest first 876 // remove the oldest packet, look forward, as it's oldest first
777 for (vector<dns_rcv *>::iterator j = rcvpq.begin (); j != rcvpq.end (); ++j) 877 for (vector<dns_rcv *>::iterator j = rcvpq.begin (); j != rcvpq.end (); ++j)
778 if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW)) 878 if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW))
779 { 879 {
880 //printf ("seqno RR %x %x\n", (*j)->seqno, rcvseq - MAX_WINDOW);//D
780 delete *j; 881 delete *j;
781 rcvpq.erase (j); 882 rcvpq.erase (j);
782 break; 883 break;
783 } 884 }
784 885
785 rcvseq = (rcvseq + 1) & SEQNO_MASK; 886 rcvseq = (rcvseq + 1) & SEQNO_MASK;
786 887
787 if (!rcvdq.put (r->data, r->datalen)) 888 if (!rcvdq.put (r->data, r->datalen))
788 { 889 {
890 // MUST never overflow, can be caused by data corruption, TODO
789 slog (L_ERR, "DNS: !rcvdq.put (r->data, r->datalen)"); 891 slog (L_CRIT, "DNS: !rcvdq.put (r->data, r->datalen)");
790 abort (); // MUST never overflow, can be caused by data corruption, TODO 892 reset ();
893 return;
791 } 894 }
792 895
793 while (vpn_packet *pkt = rcvdq.get ()) 896 while (vpn_packet *pkt = rcvdq.get ())
794 { 897 {
795 sockinfo si; 898 sockinfo si;
796 si.host = 0x01010101; si.port = htons (c->conf->id); si.prot = PROT_DNSv4; 899 si.host = htonl (c->conf->id); si.port = 0; si.prot = PROT_DNSv4;
797 900
798 vpn->recv_vpn_packet (pkt, si); 901 vpn->recv_vpn_packet (pkt, si);
799
800 delete pkt; 902 delete pkt;
801 } 903 }
802 904
803 // check for further packets 905 // check for further packets
804 goto redo; 906 goto redo;
… …
847 { 949 {
848 // correct class, domain: parse 950 // correct class, domain: parse
849 int client, seqno; 951 int client, seqno;
850 decode_header (qname, client, seqno); 952 decode_header (qname, client, seqno);
851 953
852 u8 data[MAXSIZE];
853 int datalen = cdc62.decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE));
854
855 if (0 < client && client <= conns.size ()) 954 if (0 < client && client <= conns.size ())
856 { 955 {
857 connection *c = conns [client - 1]; 956 connection *c = conns [client - 1];
858 dns_connection *dns = c->dns; 957 dns_connection *dns = c->dns;
859 dns_rcv *rcv; 958 dns_rcv *rcv;
860 bool in_seq;
861 959
862 if (dns) 960 if (dns)
863 { 961 {
962 u8 data[MAXSIZE];
963 int datalen = dns->cdc->decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE));
964
864 for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); ) 965 for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); )
865 if (SEQNO_EQ ((*i)->seqno, seqno)) 966 if (SEQNO_EQ ((*i)->seqno, seqno))
866 { 967 {
867 // already seen that request: simply reply with the cached reply 968 // already seen that request: simply reply with the cached reply
868 dns_rcv *r = *i; 969 dns_rcv *r = *i;
… …
876 memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len); 977 memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len);
877 978
878 goto duplicate_request; 979 goto duplicate_request;
879 } 980 }
880 981
881 in_seq = dns->rcvseq == seqno;
882
883 // new packet, queue 982 // new packet, queue
884 rcv = new dns_rcv (seqno, data, datalen); 983 rcv = new dns_rcv (seqno, data, datalen);
885 dns->receive_rep (rcv); 984 dns->receive_rep (rcv);
886 } 985 }
887 986
… …
904 dlen -= qlen; 1003 dlen -= qlen;
905 1004
906 // only put data into in-order sequence packets, if 1005 // only put data into in-order sequence packets, if
907 // we receive out-of-order packets we generate empty 1006 // we receive out-of-order packets we generate empty
908 // replies 1007 // replies
909 while (dlen > 1 && !dns->snddq.empty () && in_seq) 1008 //printf ("%d - %d & %x (=%d) < %d\n", seqno, dns->repseq, SEQNO_MASK, (seqno - dns->repseq) & SEQNO_MASK, MAX_WINDOW);//D
1009 if (((seqno - dns->repseq) & SEQNO_MASK) <= MAX_WINDOW)
910 { 1010 {
1011 dns->repseq = seqno;
1012
1013 while (dlen > 1 && !dns->snddq.empty ())
1014 {
911 int txtlen = dlen <= 255 ? dlen - 1 : 255; 1015 int txtlen = dlen <= 255 ? dlen - 1 : 255;
912 1016
913 if (txtlen > dns->snddq.size ()) 1017 if (txtlen > dns->snddq.size ())
914 txtlen = dns->snddq.size (); 1018 txtlen = dns->snddq.size ();
915 1019
916 pkt[offs++] = txtlen; 1020 pkt[offs++] = txtlen;
917 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen); 1021 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
918 offs += txtlen; 1022 offs += txtlen;
919 dns->snddq.remove (txtlen); 1023 dns->snddq.remove (txtlen);
920 1024
921 dlen -= txtlen + 1; 1025 dlen -= txtlen + 1;
1026 }
922 } 1027 }
923 1028
924 // avoid empty TXT rdata 1029 // avoid completely empty TXT rdata
925 if (offs == rdlen_offs) 1030 if (offs == rdlen_offs)
926 pkt[offs++] = 0; 1031 pkt[offs++] = 0;
927 1032
928 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ()); 1033 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
929 } 1034 }
… …
965 pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class 1070 pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
966 pkt [offs++] = 0; pkt [offs++] = 0; 1071 pkt [offs++] = 0; pkt [offs++] = 0;
967 pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL 1072 pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL
968 pkt [offs++] = 0; pkt [offs++] = 4; // rdlength 1073 pkt [offs++] = 0; pkt [offs++] = 4; // rdlength
969 1074
970 slog (L_INFO, _("DNS: client %d connects"), client);
971
972 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3; 1075 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
973 pkt [offs++] = CMD_IP_REJ; 1076 pkt [offs++] = CMD_IP_REJ;
974 1077
975 if (0 < client && client <= conns.size ()) 1078 if (0 < client && client <= conns.size ())
976 { 1079 {
977 connection *c = conns [client - 1]; 1080 connection *c = conns [client - 1];
978 1081
979 if (cfg.valid ()) 1082 if (cfg.valid ())
980 { 1083 {
981 pkt [offs - 1] = CMD_IP_SYN; 1084 slog (L_INFO, _("DNS: client %d connects (version %d, req_cdc %d)"), client, cfg.version, cfg.req_cdc);
1085
1086 // check for any encoding mismatches - hints at a case problem
1087 char qname2 [MAX_ENC_LEN];
1088 cdc26.encode (qname2, (u8 *)&cfg, sizeof (dns_cfg));
982 1089
983 delete c->dns; 1090 delete c->dns;
1091
1092 pkt [offs - 1] = memcmp (qname, qname2, cdc26.encode_len (sizeof (dns_cfg)))
1093 ? CMD_IP_CSE : CMD_IP_SYN;
1094
984 c->dns = new dns_connection (c); 1095 c->dns = new dns_connection (c);
985 c->dns->cfg = cfg; 1096 c->dns->cfg = cfg;
1097 c->dns->set_cfg ();
986 } 1098 }
987 } 1099 }
988 } 1100 }
989 } 1101 }
990 1102
… …
1009 { 1121 {
1010 dns_connection *dns = (*i)->dns; 1122 dns_connection *dns = (*i)->dns;
1011 connection *c = dns->c; 1123 connection *c = dns->c;
1012 int seqno = (*i)->seqno; 1124 int seqno = (*i)->seqno;
1013 u8 data[MAXSIZE], *datap = data; 1125 u8 data[MAXSIZE], *datap = data;
1126 //printf ("rcv pkt %x\n", seqno);//D
1014 1127
1015 if ((*i)->retry) 1128 if ((*i)->retry)
1016 { 1129 {
1017 dns->send_interval *= 1.01; 1130 dns->send_interval *= 1.01;
1018 if (dns->send_interval > MAX_SEND_INTERVAL) 1131 if (dns->send_interval > MAX_SEND_INTERVAL)
… …
1023#if 0 1136#if 0
1024 dns->send_interval *= 0.999; 1137 dns->send_interval *= 0.999;
1025#endif 1138#endif
1026 // the latency surely puts an upper bound on 1139 // the latency surely puts an upper bound on
1027 // the minimum send interval 1140 // the minimum send interval
1028 double latency = NOW - (*i)->sent; 1141 double latency = ev_now () - (*i)->sent;
1029 1142
1030 if (latency < dns->min_latency) 1143 if (latency < dns->min_latency)
1031 dns->min_latency = latency; 1144 dns->min_latency = latency;
1032 1145
1033 if (dns->send_interval > dns->min_latency * LATENCY_FACTOR) 1146 if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor)
1034 dns->send_interval = dns->min_latency * LATENCY_FACTOR; 1147 dns->send_interval = dns->min_latency * conf.dns_overlap_factor;
1035 1148
1036 if (dns->send_interval < MIN_SEND_INTERVAL) 1149 if (dns->send_interval < conf.dns_send_interval)
1037 dns->send_interval = MIN_SEND_INTERVAL; 1150 dns->send_interval = conf.dns_send_interval;
1038 } 1151 }
1039 1152
1040 delete *i; 1153 delete *i;
1041 dns_sndpq.erase (i); 1154 dns_sndpq.erase (i);
1042 1155
… …
1060 ttl |= pkt [offs++] << 16; 1173 ttl |= pkt [offs++] << 16;
1061 ttl |= pkt [offs++] << 8; 1174 ttl |= pkt [offs++] << 8;
1062 ttl |= pkt [offs++]; 1175 ttl |= pkt [offs++];
1063 u16 rdlen = pkt [offs++] << 8; rdlen |= pkt [offs++]; 1176 u16 rdlen = pkt [offs++] << 8; rdlen |= pkt [offs++];
1064 1177
1065 if (qtype == RR_TYPE_NULL || qtype == RR_TYPE_TXT) 1178 if (qtype == RR_TYPE_NULL || qtype == RR_TYPE_TXT || qtype == dns->cfg.rrtype)
1066 { 1179 {
1067 if (rdlen <= MAXSIZE - offs) 1180 if (rdlen <= MAXSIZE - offs)
1068 { 1181 {
1069 // decode bytes, finally 1182 // decode bytes, finally
1070 1183
… …
1096 { 1209 {
1097 slog (L_TRACE, _("DNS: got tunnel meta command %02x"), ip [3]); 1210 slog (L_TRACE, _("DNS: got tunnel meta command %02x"), ip [3]);
1098 1211
1099 if (ip [3] == CMD_IP_RST) 1212 if (ip [3] == CMD_IP_RST)
1100 { 1213 {
1101 slog (L_DEBUG, _("DNS: got tunnel RST request")); 1214 slog (L_DEBUG, _("DNS: got tunnel RST request."));
1102 1215
1103 delete dns; c->dns = 0; 1216 dns->reset ();
1104
1105 return; 1217 return;
1106 } 1218 }
1107 else if (ip [3] == CMD_IP_SYN) 1219 else if (ip [3] == CMD_IP_SYN)
1108 { 1220 {
1109 slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us.")); 1221 slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us."));
1110 dns->established = true; 1222 dns->established = true;
1111 } 1223 }
1224 else if (ip [3] == CMD_IP_CSE)
1225 {
1226 if (conf.dns_case_preserving)
1227 {
1228 slog (L_INFO, _("DNS: got tunnel CSE reply, globally downgrading to case-insensitive protocol."));
1229 conf.dns_case_preserving = false;
1230 dns->reset ();
1231 return;
1232 }
1233 else
1234 {
1235 slog (L_DEBUG, _("DNS: got tunnel CSE reply, server likes us."));
1236 dns->established = true;
1237 }
1238 }
1112 else if (ip [3] == CMD_IP_REJ) 1239 else if (ip [3] == CMD_IP_REJ)
1113 { 1240 {
1114 slog (L_DEBUG, _("DNS: got tunnel REJ reply, server does not like us, aborting.")); 1241 slog (L_ERR, _("DNS: got tunnel REJ reply, server does not like us."));
1115 abort (); 1242 dns->tw.start (60.);
1116 } 1243 }
1117 else 1244 else
1245 {
1118 slog (L_INFO, _("DNS: got unknown meta command %02x"), ip [3]); 1246 slog (L_INFO, _("DNS: got unknown meta command %02x"), ip [3]);
1247 dns->tw.start (60.);
1248 }
1119 } 1249 }
1120 else 1250 else
1121 slog (L_INFO, _("DNS: got spurious a record %d.%d.%d.%d"), 1251 slog (L_INFO, _("DNS: got spurious a record %d.%d.%d.%d"),
1122 ip [0], ip [1], ip [2], ip [3]); 1252 ip [0], ip [1], ip [2], ip [3]);
1123 1253
… …
1147 break; 1277 break;
1148 } 1278 }
1149} 1279}
1150 1280
1151void 1281void
1152vpn::dnsv4_ev (io_watcher &w, short revents) 1282vpn::dnsv4_ev (ev::io &w, int revents)
1153{ 1283{
1154 if (revents & EVENT_READ) 1284 if (revents & EV_READ)
1155 { 1285 {
1156 dns_packet *pkt = new dns_packet; 1286 dns_packet *pkt = new dns_packet;
1157 struct sockaddr_in sa; 1287 struct sockaddr_in sa;
1158 socklen_t sa_len = sizeof (sa); 1288 socklen_t sa_len = sizeof (sa);
1159 1289
… …
1175} 1305}
1176 1306
1177bool 1307bool
1178vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) 1308vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
1179{ 1309{
1180 int client = ntohs (si.port); 1310 int client = ntohl (si.host);
1181 1311
1182 assert (0 < client && client <= conns.size ()); 1312 assert (0 < client && client <= conns.size ());
1183 1313
1184 connection *c = conns [client - 1]; 1314 connection *c = conns [client - 1];
1185 1315
1186 if (!c->dns) 1316 if (!c->dns)
1187 c->dns = new dns_connection (c); 1317 c->dns = new dns_connection (c);
1188 1318
1189 if (!c->dns->snddq.put (pkt)) 1319 if (c->dns->snddq.put (pkt))
1190 return false; 1320 {
1321 min_it (c->dns->poll_interval, 0.25);
1322 c->dns->tw ();
1323 }
1191 1324
1192 c->dns->tw.trigger (); 1325 // always return true even if the buffer overflows
1193
1194 return true; 1326 return true;
1195} 1327}
1196 1328
1197void 1329void
1198connection::dnsv4_reset_connection () 1330dns_connection::time_cb (ev::timer &w, int revents)
1199{
1200 //delete dns; dns = 0; //TODO
1201}
1202
1203#define NEXT(w) do { if (next > (w)) next = w; } while (0)
1204
1205void
1206dns_connection::time_cb (time_watcher &w)
1207{ 1331{
1208 // servers have to be polled 1332 // servers have to be polled
1209 if (THISNODE->dns_port) 1333 if (THISNODE->dns_port)
1210 return; 1334 return;
1211 1335
1212 // check for timeouts and (re)transmit 1336 // check for timeouts and (re)transmit
1213 tstamp next = NOW + poll_interval; 1337 tstamp next = 86400 * 365;
1214 dns_snd *send = 0; 1338 dns_snd *send = 0;
1215 1339
1216 for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin (); 1340 for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin ();
1217 i != vpn->dns_sndpq.end (); 1341 i != vpn->dns_sndpq.end ();
1218 ++i) 1342 ++i)
1219 { 1343 {
1220 dns_snd *r = *i; 1344 dns_snd *r = *i;
1221 1345
1222 if (r->timeout <= NOW) 1346 if (r->timeout <= ev_now ())
1223 { 1347 {
1224 if (!send) 1348 if (!send)
1225 { 1349 {
1226 send = r; 1350 send = r;
1227 1351
1228 r->retry++; 1352 r->retry++;
1229 r->timeout = NOW + (r->retry * min_latency * 8.); 1353 r->timeout = ev_now () + r->retry * min_latency * conf.dns_timeout_factor;
1354 //printf ("RETRY %x (%d, %f)\n", r->seqno, r->retry, r->timeout - ev_now ());//D
1230 1355
1231 // the following code changes the query section a bit, forcing 1356 // the following code changes the query section a bit, forcing
1232 // the forwarder to generate a new request 1357 // the forwarder to generate a new request
1233 if (r->stdhdr) 1358 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); 1359 encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry);
1237 }
1238 } 1360 }
1239 } 1361 }
1240 else 1362 else
1241 NEXT (r->timeout); 1363 min_it (next, r->timeout - ev_now ());
1242 } 1364 }
1243 1365
1244 if (!send) 1366 if (!send)
1245 { 1367 {
1246 // generate a new packet, if wise 1368 // generate a new packet, if wise
… …
1250 if (vpn->dns_sndpq.empty ()) 1372 if (vpn->dns_sndpq.empty ())
1251 { 1373 {
1252 send = new dns_snd (this); 1374 send = new dns_snd (this);
1253 1375
1254 cfg.reset (THISNODE->id); 1376 cfg.reset (THISNODE->id);
1377 set_cfg ();
1255 send->gen_syn_req (); 1378 send->gen_syn_req ();
1256 } 1379 }
1257 } 1380 }
1258 else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING 1381 else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding
1259 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) 1382 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
1260 { 1383 {
1261 if (last_sent + send_interval <= NOW) 1384 if (last_sent + send_interval <= ev_now ())
1262 { 1385 {
1263 //printf ("sending data request etc.\n"); //D 1386 //printf ("sending data request etc.\n"); //D
1264 if (!snddq.empty () || last_received + 1. > NOW) 1387 if (!snddq.empty ())
1265 {
1266 poll_interval = send_interval;
1267 NEXT (NOW + send_interval); 1388 min_it (next, send_interval);
1268 }
1269 1389
1270 send = new dns_snd (this); 1390 send = new dns_snd (this);
1271 send->gen_stream_req (sndseq, snddq); 1391 send->gen_stream_req (sndseq, snddq);
1272 send->timeout = NOW + min_latency * 8.; 1392 send->timeout = ev_now () + min_latency * conf.dns_timeout_factor;
1393 //printf ("SEND %x (%f)\n", send->seqno, send->timeout - ev_now (), min_latency, conf.dns_timeout_factor);//D
1273 1394
1274 sndseq = (sndseq + 1) & SEQNO_MASK; 1395 sndseq = (sndseq + 1) & SEQNO_MASK;
1275 } 1396 }
1276 else 1397 else
1277 NEXT (last_sent + send_interval); 1398 min_it (next, last_sent + send_interval - ev_now ());
1278 } 1399 }
1279 1400
1280 if (send) 1401 if (send)
1281 vpn->dns_sndpq.push_back (send); 1402 vpn->dns_sndpq.push_back (send);
1282 } 1403 }
1283 1404
1284 if (send) 1405 if (send)
1285 { 1406 {
1286 last_sent = NOW; 1407 last_sent = ev_now ();
1287 sendto (vpn->dnsv4_fd, 1408 sendto (vpn->dnsv4_fd,
1288 send->pkt->at (0), send->pkt->len, 0, 1409 send->pkt->at (0), send->pkt->len, 0,
1289 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); 1410 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
1290 } 1411 }
1291 1412
1413 min_it (next, last_sent + max (poll_interval, send_interval) - ev_now ());
1414
1292 slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)", 1415 slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)",
1293 poll_interval, send_interval, next - NOW, 1416 poll_interval, send_interval, next - ev_now (),
1294 vpn->dns_sndpq.size (), snddq.size (), 1417 vpn->dns_sndpq.size (), snddq.size (),
1295 rcvpq.size ()); 1418 rcvpq.size ());
1296 1419
1297 // TODO: no idea when this happens, but when next < NOW, we have a problem
1298 if (next < NOW + 0.001)
1299 next = NOW + 0.1;
1300
1301 w.start (next); 1420 w.start (next);
1302} 1421}
1303 1422
1304#endif 1423#endif
1305 1424

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