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Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.26 by pcg, Tue Mar 8 17:25:27 2005 UTC vs.
Revision 1.53 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 LATENCY_FACTOR 0.5 // RTT * LATENCY_FACTOR == sending rate
60#define MAX_OUTSTANDING 20 // max. outstanding requests
61#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog 72#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog
62#define MAX_BACKLOG (100*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE 73#define MAX_BACKLOG (64*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE
63 74
64#define MAX_DOMAIN_SIZE 200 // 255 is legal limit, but bind doesn't compress well 75#define MAX_DOMAIN_SIZE 235 // 255 is legal limit, but bind doesn't compress well
65// 240 leaves about 4 bytes of server reply data 76// 240 leaves about 4 bytes of server reply data
66// every two request bytes less give room for one reply byte 77// every request byte less give room for two reply bytes
67 78
68#define SEQNO_MASK 0x3fff 79#define SEQNO_MASK 0x3fff
69#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) ) 80#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )
70 81
71#define MAX_LBL_SIZE 63 82#define MAX_LBL_SIZE 63
72#define MAX_PKT_SIZE 512 83#define MAX_PKT_SIZE 512
73 84
74#define RR_TYPE_A 1 85#define RR_TYPE_A 1
75#define RR_TYPE_NULL 10 86#define RR_TYPE_NULL 10
76#define RR_TYPE_TXT 16 87#define RR_TYPE_TXT 16
88#define RR_TYPE_AAAA 28
77#define RR_TYPE_ANY 255 89#define RR_TYPE_ANY 255
78 90
79#define RR_CLASS_IN 1 91#define RR_CLASS_IN 1
80 92
81#define CMD_IP_1 207 93#define CMD_IP_1 207
82#define CMD_IP_2 46 94#define CMD_IP_2 46
83#define CMD_IP_3 236 95#define CMD_IP_3 236
84#define CMD_IP_RST 29 96
85#define CMD_IP_SYN 113 97#define CMD_IP_RST 29 // some error, reset and retry
86#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}
87 113
88// works for cmaps up to 255 (not 256!) 114// works for cmaps up to 255 (not 256!)
89struct charmap 115struct charmap
90{ 116{
91 enum { INVALID = (u8)255 }; 117 enum { INVALID = (u8)255 };
… …
105 memset (enc, (char) 0, 256); 131 memset (enc, (char) 0, 256);
106 memset (dec, (char)INVALID, 256); 132 memset (dec, (char)INVALID, 256);
107 133
108 for (size = 0; cmap [size]; size++) 134 for (size = 0; cmap [size]; size++)
109 { 135 {
136 char c = cmap [size];
137
110 enc [size] = cmap [size]; 138 enc [size] = c;
111 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;
112 } 144 }
113 145
114 assert (size < 256); 146 assert (size < 256);
115} 147}
116 148
… …
123{ 155{
124 charmap cmap; 156 charmap cmap;
125 unsigned int enc_len [MAX_DEC_LEN]; 157 unsigned int enc_len [MAX_DEC_LEN];
126 unsigned int dec_len [MAX_ENC_LEN]; 158 unsigned int dec_len [MAX_ENC_LEN];
127 159
128 unsigned int encode_len (unsigned int len); 160 unsigned int encode_len (unsigned int len) const;
129 unsigned int decode_len (unsigned int len); 161 unsigned int decode_len (unsigned int len) const;
130 162
131 unsigned int encode (char *dst, u8 *src, unsigned int len); 163 unsigned int encode (char *dst, u8 *src, unsigned int len) const;
132 unsigned int decode (u8 *dst, char *src, unsigned int len); 164 unsigned int decode (u8 *dst, char *src, unsigned int len) const;
133 165
134 basecoder (const char *cmap); 166 basecoder (const char *cmap);
135}; 167};
136 168
137basecoder::basecoder (const char *cmap) 169basecoder::basecoder (const char *cmap)
… …
156 enc_len [len] = n; 188 enc_len [len] = n;
157 dec_len [n] = len; 189 dec_len [n] = len;
158 } 190 }
159} 191}
160 192
193unsigned int
161unsigned int basecoder::encode_len (unsigned int len) 194basecoder::encode_len (unsigned int len) const
162{ 195{
163 return enc_len [len]; 196 return enc_len [len];
164} 197}
165 198
199unsigned int
166unsigned int basecoder::decode_len (unsigned int len) 200basecoder::decode_len (unsigned int len) const
167{ 201{
168 while (len && !dec_len [len]) 202 while (len && !dec_len [len])
169 --len; 203 --len;
170 204
171 return dec_len [len]; 205 return dec_len [len];
172} 206}
173 207
208unsigned int
174unsigned int basecoder::encode (char *dst, u8 *src, unsigned int len) 209basecoder::encode (char *dst, u8 *src, unsigned int len) const
175{ 210{
176 if (!len || len > MAX_DEC_LEN) 211 if (!len || len > MAX_DEC_LEN)
177 return 0; 212 return 0;
178 213
179 int elen = encode_len (len); 214 int elen = encode_len (len);
… …
198 *dst++ = cmap.encode [dst_ [i]]; 233 *dst++ = cmap.encode [dst_ [i]];
199 234
200 return elen; 235 return elen;
201} 236}
202 237
238unsigned int
203unsigned int basecoder::decode (u8 *dst, char *src, unsigned int len) 239basecoder::decode (u8 *dst, char *src, unsigned int len) const
204{ 240{
205 if (!len || len > MAX_ENC_LEN) 241 if (!len || len > MAX_ENC_LEN)
206 return 0; 242 return 0;
207 243
208 u8 src_ [MAX_ENC_LEN]; 244 u8 src_ [MAX_ENC_LEN];
… …
257 } 293 }
258 abort (); 294 abort ();
259} 295}
260#endif 296#endif
261 297
262//static basecoder cdc64 ("_dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI-");
263//static basecoder cdc63 ("_dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI");
264static basecoder cdc62 ("dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI"); 298static basecoder cdc62 ("dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI"); // a-zA-Z0-9
265//static basecoder cdc36 ("dphzr06qmjkb34tsvl81xaef92wgyo57ucni"); // unused as of yet 299static basecoder cdc36 ("dPhZr06QmJkB34tSvL81xAeF92wGyO57uCnI"); // a-z0-9 for case-changers
266static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO"); 300static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyOuCnI"); // a-z
267 301
268///////////////////////////////////////////////////////////////////////////// 302/////////////////////////////////////////////////////////////////////////////
269 303
270#define HDRSIZE 6 304#define HDRSIZE 5
271 305
306inline void
272inline void encode_header (char *data, int clientid, int seqno, int retry = 0) 307encode_header (char *data, int clientid, int seqno, int retry = 0)
273{ 308{
309 assert (clientid < 256);
310
274 seqno &= SEQNO_MASK; 311 seqno &= SEQNO_MASK;
275 312
276 u8 hdr[3] = { 313 u8 hdr[3] = {
314 seqno,
315 (seqno >> 8) | (retry << 6),
277 clientid, 316 clientid,
278 (seqno >> 8) | (retry << 6),
279 seqno,
280 }; 317 };
281 318
282 assert (clientid < 256);
283
284 cdc26.encode (data, hdr, 3); 319 cdc36.encode (data, hdr, 3);
285} 320}
286 321
322inline void
287inline void decode_header (char *data, int &clientid, int &seqno) 323decode_header (char *data, int &clientid, int &seqno)
288{ 324{
289 u8 hdr[3]; 325 u8 hdr[3];
290 326
291 cdc26.decode (hdr, data, HDRSIZE); 327 cdc36.decode (hdr, data, HDRSIZE);
292 328
293 clientid = hdr[0]; 329 clientid = hdr[2];
294 seqno = ((hdr[1] << 8) | hdr[2]) & SEQNO_MASK; 330 seqno = ((hdr[1] << 8) | hdr[0]) & SEQNO_MASK;
295} 331}
296 332
297///////////////////////////////////////////////////////////////////////////// 333/////////////////////////////////////////////////////////////////////////////
298 334
299struct byte_stream 335struct byte_stream
… …
325byte_stream::~byte_stream () 361byte_stream::~byte_stream ()
326{ 362{
327 delete data; 363 delete data;
328} 364}
329 365
366void
330void byte_stream::remove (int count) 367byte_stream::remove (int count)
331{ 368{
332 if (count > fill) 369 if (count > fill)
333 assert (count <= fill); 370 assert (count <= fill);
334 371
335 memmove (data, data + count, fill -= count); 372 memmove (data, data + count, fill -= count);
336} 373}
337 374
375bool
338bool byte_stream::put (u8 *data, unsigned int datalen) 376byte_stream::put (u8 *data, unsigned int datalen)
339{ 377{
340 if (maxsize - fill < datalen) 378 if (maxsize - fill < datalen)
341 return false; 379 return false;
342 380
343 memcpy (this->data + fill, data, datalen); fill += datalen; 381 memcpy (this->data + fill, data, datalen); fill += datalen;
344 382
345 return true; 383 return true;
346} 384}
347 385
386bool
348bool byte_stream::put (vpn_packet *pkt) 387byte_stream::put (vpn_packet *pkt)
349{ 388{
350 if (maxsize - fill < pkt->len + 2) 389 if (maxsize - fill < pkt->len + 2)
351 return false; 390 return false;
352 391
353 data [fill++] = pkt->len >> 8; 392 data [fill++] = pkt->len >> 8;
… …
409 448
410struct dns_cfg 449struct dns_cfg
411{ 450{
412 static int next_uid; 451 static int next_uid;
413 452
414 u8 id1, id2, id3, id4; 453 u8 chksum;
454 u8 rrtype;
455 u16 uid; // to make request unique
415 456
416 u8 version; 457 u8 version;
417 u8 flags; 458 u8 flags;
418 u8 rrtype; 459 u16 max_size;
460
461 u8 id1, id2, id3, id4;
462
463 u16 client;
419 u8 def_ttl; 464 u8 def_ttl;
465 u8 r0;
420 466
421 u16 client; 467 u8 syn_cdc; // cdc en/decoder for syn (A?) requests
422 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
423 471
424 u16 max_size;
425 u8 seq_cdc;
426 u8 req_cdc;
427
428 u8 rep_cdc;
429 u8 r2, r3, r4; 472 u8 r1, r2, r3, r4;
430
431 u8 r5, r6, r7, r8;
432 473
433 void reset (int clientid); 474 void reset (int clientid);
434 bool valid (); 475 bool valid ();
476 u8 get_chksum ();
435}; 477};
436 478
437int dns_cfg::next_uid; 479int dns_cfg::next_uid;
438 480
481void
439void dns_cfg::reset (int clientid) 482dns_cfg::reset (int clientid)
440{ 483{
484 // this ID must result in some mixed-case characters in cdc26-encoding
441 id1 = 'G'; 485 id1 = 'G';
442 id2 = 'V'; 486 id2 = 'V';
443 id3 = 'P'; 487 id3 = 'P';
444 id4 = 'E'; 488 id4 = 'E';
445 489
446 version = 1; 490 version = 2;
447 491
448 rrtype = RR_TYPE_TXT; 492 rrtype = RR_TYPE_TXT;
449 flags = 0; 493 flags = 0;
450 def_ttl = 0; 494 def_ttl = 0;
451 seq_cdc = 26; 495 syn_cdc = 26;
452 req_cdc = 62; 496 hdr_cdc = 36;
497 req_cdc = conf.dns_case_preserving ? 62 : 36;
453 rep_cdc = 0; 498 rep_cdc = 0;
454 max_size = ntohs (MAX_PKT_SIZE); 499 max_size = htons (MAX_PKT_SIZE);
455 client = ntohs (clientid); 500 client = htons (clientid);
456 uid = next_uid++; 501 uid = ++next_uid;
457 502
458 r2 = r3 = r4 = 0; 503 r0 = r1 = r2 = r3 = r4 = 0;
459 r4 = r5 = r6 = r7 = 0;
460}
461 504
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
462bool dns_cfg::valid () 526dns_cfg::valid ()
463{ 527{
528 // although the protocol itself allows for some configurability,
529 // only the following encoding/decoding settings are implemented.
464 return id1 == 'G' 530 return id1 == 'G'
465 && id2 == 'V' 531 && id2 == 'V'
466 && id3 == 'P' 532 && id3 == 'P'
467 && id4 == 'E' 533 && id4 == 'E'
534 && version == 2
468 && seq_cdc == 26 535 && syn_cdc == 26
469 && req_cdc == 62 536 && hdr_cdc == 36
537 && (req_cdc == 36 || req_cdc == 62)
470 && rep_cdc == 0 538 && rep_cdc == 0
471 && version == 1 539 && chksum == get_chksum ();
472 && max_size == ntohs (MAX_PKT_SIZE);
473} 540}
474 541
475struct dns_packet : net_packet 542struct dns_packet : net_packet
476{ 543{
477 u16 id; 544 u16 id;
… …
481 u8 data [MAXSIZE - 6 * 2]; 548 u8 data [MAXSIZE - 6 * 2];
482 549
483 int decode_label (char *data, int size, int &offs); 550 int decode_label (char *data, int size, int &offs);
484}; 551};
485 552
553int
486int dns_packet::decode_label (char *data, int size, int &offs) 554dns_packet::decode_label (char *data, int size, int &offs)
487{ 555{
488 char *orig = data; 556 char *orig = data;
489 557
490 memset (data, 0, size); 558 memset (data, 0, size);
491 559
… …
517 return data - orig; 585 return data - orig;
518} 586}
519 587
520///////////////////////////////////////////////////////////////////////////// 588/////////////////////////////////////////////////////////////////////////////
521 589
590static
591u16 next_id ()
592{
522static u16 dns_id = 0; // TODO: should be per-vpn 593 static u16 dns_id = 0; // TODO: should be per-vpn
523 594
524static u16 next_id () 595#if 1
525{
526 if (!dns_id) 596 if (!dns_id)
527 dns_id = time (0); 597 dns_id = time (0);
528 598
529 // the simplest lsfr with periodicity 65535 i could find 599 // the simplest lsfr with periodicity 65535 i could find
530 dns_id = (dns_id << 1) 600 dns_id = (dns_id << 1)
… …
532 ^ (dns_id >> 2) 602 ^ (dns_id >> 2)
533 ^ (dns_id >> 4) 603 ^ (dns_id >> 4)
534 ^ (dns_id >> 15)) & 1); 604 ^ (dns_id >> 15)) & 1);
535 605
536 return dns_id; 606 return dns_id;
607#else
608 dns_id++;//D
609
610 return htons (dns_id);
611#endif
537} 612}
538 613
539struct dns_rcv; 614struct dns_rcv;
540struct dns_snd; 615struct dns_snd;
541 616
… …
545 struct vpn *vpn; 620 struct vpn *vpn;
546 621
547 dns_cfg cfg; 622 dns_cfg cfg;
548 623
549 bool established; 624 bool established;
625 const basecoder *cdc;
550 626
551 tstamp last_received; 627 tstamp last_received;
552 tstamp last_sent; 628 tstamp last_sent;
553 double min_latency; 629 double min_latency;
554 double poll_interval, send_interval; 630 double poll_interval, send_interval;
555 631
556 vector<dns_rcv *> rcvpq; 632 vector<dns_rcv *> rcvpq;
557 633
558 byte_stream rcvdq; int rcvseq; 634 byte_stream rcvdq; int rcvseq; int repseq;
559 byte_stream snddq; int sndseq; 635 byte_stream snddq; int sndseq;
560 636
561 void time_cb (time_watcher &w); time_watcher tw; 637 inline void time_cb (ev::timer &w, int revents); ev::timer tw;
562 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
563 642
564 dns_connection (connection *c); 643 dns_connection (connection *c);
565 ~dns_connection (); 644 ~dns_connection ();
566}; 645};
567 646
… …
585: dns (dns) 664: dns (dns)
586{ 665{
587 timeout = 0; 666 timeout = 0;
588 retry = 0; 667 retry = 0;
589 seqno = 0; 668 seqno = 0;
590 sent = NOW; 669 sent = ev_now ();
591 stdhdr = false; 670 stdhdr = false;
592 671
593 pkt = new dns_packet; 672 pkt = new dns_packet;
594 673
595 pkt->id = next_id (); 674 pkt->id = next_id ();
… …
598dns_snd::~dns_snd () 677dns_snd::~dns_snd ()
599{ 678{
600 delete pkt; 679 delete pkt;
601} 680}
602 681
682static void
603static void append_domain (dns_packet &pkt, int &offs, const char *domain) 683append_domain (dns_packet &pkt, int &offs, const char *domain)
604{ 684{
605 // add tunnel domain 685 // add tunnel domain
606 for (;;) 686 for (;;)
607 { 687 {
608 const char *end = strchr (domain, '.'); 688 const char *end = strchr (domain, '.');
… …
621 701
622 domain = end + 1; 702 domain = end + 1;
623 } 703 }
624} 704}
625 705
706void
626void dns_snd::gen_stream_req (int seqno, byte_stream &stream) 707dns_snd::gen_stream_req (int seqno, byte_stream &stream)
627{ 708{
628 stdhdr = true; 709 stdhdr = true;
629 this->seqno = seqno; 710 this->seqno = seqno;
630 711
631 timeout = NOW + INITIAL_TIMEOUT; 712 timeout = ev_now () + INITIAL_TIMEOUT;
632 713
633 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 714 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
634 pkt->qdcount = htons (1); 715 pkt->qdcount = htons (1);
635 716
636 int offs = 6*2; 717 int offs = 6*2;
… …
639 // 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
640 721
641 char enc[256], *encp = enc; 722 char enc[256], *encp = enc;
642 encode_header (enc, THISNODE->id, seqno); 723 encode_header (enc, THISNODE->id, seqno);
643 724
644 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);
645 726
646 if (datalen > stream.size ()) 727 if (datalen > stream.size ())
647 datalen = stream.size (); 728 datalen = stream.size ();
648 729
649 int enclen = cdc62.encode (enc + HDRSIZE, stream.begin (), datalen) + HDRSIZE; 730 int enclen = dns->cdc->encode (enc + HDRSIZE, stream.begin (), datalen) + HDRSIZE;
650 stream.remove (datalen); 731 stream.remove (datalen);
651 732
652 while (enclen) 733 while (enclen)
653 { 734 {
654 int lbllen = enclen < MAX_LBL_SIZE ? enclen : MAX_LBL_SIZE; 735 int lbllen = enclen < MAX_LBL_SIZE ? enclen : MAX_LBL_SIZE;
… …
669 (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN; 750 (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN;
670 751
671 pkt->len = offs; 752 pkt->len = offs;
672} 753}
673 754
755void
674void dns_snd::gen_syn_req () 756dns_snd::gen_syn_req ()
675{ 757{
676 timeout = NOW + INITIAL_SYN_TIMEOUT; 758 timeout = ev_now () + INITIAL_SYN_TIMEOUT;
677 759
678 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 760 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
679 pkt->qdcount = htons (1); 761 pkt->qdcount = htons (1);
680 762
681 int offs = 6 * 2; 763 int offs = 6 * 2;
… …
720///////////////////////////////////////////////////////////////////////////// 802/////////////////////////////////////////////////////////////////////////////
721 803
722dns_connection::dns_connection (connection *c) 804dns_connection::dns_connection (connection *c)
723: c (c) 805: c (c)
724, rcvdq (MAX_BACKLOG * 2) 806, rcvdq (MAX_BACKLOG * 2)
725, snddq (MAX_BACKLOG * 2) 807, snddq (MAX_BACKLOG)
726, tw (this, &dns_connection::time_cb)
727{ 808{
809 tw.set<dns_connection, &dns_connection::time_cb> (this);
810
728 vpn = c->vpn; 811 vpn = c->vpn;
729 812
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
730 established = false; 837 established = false;
731 838
732 rcvseq = sndseq = 0; 839 rcvseq = repseq = sndseq = 0;
733 840
734 last_sent = last_received = 0; 841 last_sent = 0;
735 poll_interval = MIN_POLL_INTERVAL; 842 poll_interval = 0.5; // starting here
736 send_interval = 0.5; // starting rate 843 send_interval = 0.5; // starting rate
737 min_latency = INITIAL_TIMEOUT; 844 min_latency = INITIAL_TIMEOUT;
738} 845}
739 846
740dns_connection::~dns_connection () 847void
848dns_connection::set_cfg ()
741{ 849{
742 for (vector<dns_rcv *>::iterator i = rcvpq.begin (); 850 cdc = cfg.req_cdc == 36 ? &cdc36 : &cdc62;
743 i != rcvpq.end ();
744 ++i)
745 delete *i;
746} 851}
747 852
853void
748void dns_connection::receive_rep (dns_rcv *r) 854dns_connection::receive_rep (dns_rcv *r)
749{ 855{
750 if (r->datalen) 856 if (r->datalen)
751 { 857 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 858 else
758 { 859 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 }
764 860
765 rcvpq.push_back (r); 861 rcvpq.push_back (r);
766 862
767 redo: 863 redo:
768 864
769 // find next packet 865 // find next packet
770 for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); ) 866 for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); )
771 if (SEQNO_EQ (rcvseq, (*i)->seqno)) 867 if (SEQNO_EQ (rcvseq, (*i)->seqno))
772 { 868 {
869 //printf ("seqno eq %x %x\n", rcvseq, (*i)->seqno);//D
773 // enter the packet into our input stream 870 // enter the packet into our input stream
774 r = *i; 871 r = *i;
775 872
776 // remove the oldest packet, look forward, as it's oldest first 873 // remove the oldest packet, look forward, as it's oldest first
777 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)
778 if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW)) 875 if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW))
779 { 876 {
877 //printf ("seqno RR %x %x\n", (*j)->seqno, rcvseq - MAX_WINDOW);//D
780 delete *j; 878 delete *j;
781 rcvpq.erase (j); 879 rcvpq.erase (j);
782 break; 880 break;
783 } 881 }
784 882
785 rcvseq = (rcvseq + 1) & SEQNO_MASK; 883 rcvseq = (rcvseq + 1) & SEQNO_MASK;
786 884
787 if (!rcvdq.put (r->data, r->datalen)) 885 if (!rcvdq.put (r->data, r->datalen))
788 { 886 {
887 // MUST never overflow, can be caused by data corruption, TODO
789 slog (L_ERR, "DNS: !rcvdq.put (r->data, r->datalen)"); 888 slog (L_CRIT, "DNS: !rcvdq.put (r->data, r->datalen)");
790 abort (); // MUST never overflow, can be caused by data corruption, TODO 889 reset ();
890 return;
791 } 891 }
792 892
793 while (vpn_packet *pkt = rcvdq.get ()) 893 while (vpn_packet *pkt = rcvdq.get ())
794 { 894 {
795 sockinfo si; 895 sockinfo si;
796 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;
797 897
798 vpn->recv_vpn_packet (pkt, si); 898 vpn->recv_vpn_packet (pkt, si);
799
800 delete pkt; 899 delete pkt;
801 } 900 }
802 901
803 // check for further packets 902 // check for further packets
804 goto redo; 903 goto redo;
… …
847 { 946 {
848 // correct class, domain: parse 947 // correct class, domain: parse
849 int client, seqno; 948 int client, seqno;
850 decode_header (qname, client, seqno); 949 decode_header (qname, client, seqno);
851 950
852 u8 data[MAXSIZE];
853 int datalen = cdc62.decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE));
854
855 if (0 < client && client <= conns.size ()) 951 if (0 < client && client <= conns.size ())
856 { 952 {
857 connection *c = conns [client - 1]; 953 connection *c = conns [client - 1];
858 dns_connection *dns = c->dns; 954 dns_connection *dns = c->dns;
859 dns_rcv *rcv; 955 dns_rcv *rcv;
860 bool in_seq;
861 956
862 if (dns) 957 if (dns)
863 { 958 {
959 u8 data[MAXSIZE];
960 int datalen = dns->cdc->decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE));
961
864 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 (); )
865 if (SEQNO_EQ ((*i)->seqno, seqno)) 963 if (SEQNO_EQ ((*i)->seqno, seqno))
866 { 964 {
867 // already seen that request: simply reply with the cached reply 965 // already seen that request: simply reply with the cached reply
868 dns_rcv *r = *i; 966 dns_rcv *r = *i;
… …
876 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);
877 975
878 goto duplicate_request; 976 goto duplicate_request;
879 } 977 }
880 978
881 in_seq = dns->rcvseq == seqno;
882
883 // new packet, queue 979 // new packet, queue
884 rcv = new dns_rcv (seqno, data, datalen); 980 rcv = new dns_rcv (seqno, data, datalen);
885 dns->receive_rep (rcv); 981 dns->receive_rep (rcv);
886 } 982 }
887 983
… …
894 pkt [offs++] = 0; pkt [offs++] = 0; 990 pkt [offs++] = 0; pkt [offs++] = 0;
895 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
896 992
897 int rdlen_offs = offs += 2; 993 int rdlen_offs = offs += 2;
898 994
899 int dlen = (dns ? ntohs (dns->cfg.max_size) : MAX_PKT_SIZE) - offs;
900 // bind doesn't compress well, so reduce further by one label length
901 dlen -= qlen;
902
903 if (dns) 995 if (dns)
904 { 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
905 // only put data into in-order sequence packets, if 1002 // only put data into in-order sequence packets, if
906 // we receive out-of-order packets we generate empty 1003 // we receive out-of-order packets we generate empty
907 // replies 1004 // replies
908 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)
909 { 1007 {
1008 dns->repseq = seqno;
1009
1010 while (dlen > 1 && !dns->snddq.empty ())
1011 {
910 int txtlen = dlen <= 255 ? dlen - 1 : 255; 1012 int txtlen = dlen <= 255 ? dlen - 1 : 255;
911 1013
912 if (txtlen > dns->snddq.size ()) 1014 if (txtlen > dns->snddq.size ())
913 txtlen = dns->snddq.size (); 1015 txtlen = dns->snddq.size ();
914 1016
915 pkt[offs++] = txtlen; 1017 pkt[offs++] = txtlen;
916 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen); 1018 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
917 offs += txtlen; 1019 offs += txtlen;
918 dns->snddq.remove (txtlen); 1020 dns->snddq.remove (txtlen);
919 1021
920 dlen -= txtlen + 1; 1022 dlen -= txtlen + 1;
1023 }
921 } 1024 }
922 1025
923 // avoid empty TXT rdata 1026 // avoid completely empty TXT rdata
924 if (offs == rdlen_offs) 1027 if (offs == rdlen_offs)
925 pkt[offs++] = 0; 1028 pkt[offs++] = 0;
926 1029
927 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ()); 1030 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
928 } 1031 }
… …
964 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
965 pkt [offs++] = 0; pkt [offs++] = 0; 1068 pkt [offs++] = 0; pkt [offs++] = 0;
966 pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL 1069 pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL
967 pkt [offs++] = 0; pkt [offs++] = 4; // rdlength 1070 pkt [offs++] = 0; pkt [offs++] = 4; // rdlength
968 1071
969 slog (L_INFO, _("DNS: client %d connects"), client);
970
971 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;
972 pkt [offs++] = CMD_IP_REJ; 1073 pkt [offs++] = CMD_IP_REJ;
973 1074
974 if (0 < client && client <= conns.size ()) 1075 if (0 < client && client <= conns.size ())
975 { 1076 {
976 connection *c = conns [client - 1]; 1077 connection *c = conns [client - 1];
977 1078
978 if (cfg.valid ()) 1079 if (cfg.valid ())
979 { 1080 {
980 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));
981 1086
982 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
983 c->dns = new dns_connection (c); 1092 c->dns = new dns_connection (c);
984 c->dns->cfg = cfg; 1093 c->dns->cfg = cfg;
1094 c->dns->set_cfg ();
985 } 1095 }
986 } 1096 }
987 } 1097 }
988 } 1098 }
989 1099
… …
1008 { 1118 {
1009 dns_connection *dns = (*i)->dns; 1119 dns_connection *dns = (*i)->dns;
1010 connection *c = dns->c; 1120 connection *c = dns->c;
1011 int seqno = (*i)->seqno; 1121 int seqno = (*i)->seqno;
1012 u8 data[MAXSIZE], *datap = data; 1122 u8 data[MAXSIZE], *datap = data;
1123 //printf ("rcv pkt %x\n", seqno);//D
1013 1124
1014 if ((*i)->retry) 1125 if ((*i)->retry)
1015 { 1126 {
1016 dns->send_interval *= 1.01; 1127 dns->send_interval *= 1.01;
1017 if (dns->send_interval > MAX_SEND_INTERVAL) 1128 if (dns->send_interval > MAX_SEND_INTERVAL)
… …
1020 else 1131 else
1021 { 1132 {
1022#if 0 1133#if 0
1023 dns->send_interval *= 0.999; 1134 dns->send_interval *= 0.999;
1024#endif 1135#endif
1025 if (dns->send_interval < MIN_SEND_INTERVAL)
1026 dns->send_interval = MIN_SEND_INTERVAL;
1027
1028 // the latency surely puts an upper bound on 1136 // the latency surely puts an upper bound on
1029 // the minimum send interval 1137 // the minimum send interval
1030 double latency = NOW - (*i)->sent; 1138 double latency = ev_now () - (*i)->sent;
1031 1139
1032 if (latency < dns->min_latency) 1140 if (latency < dns->min_latency)
1033 dns->min_latency = latency; 1141 dns->min_latency = latency;
1034 1142
1035 if (dns->send_interval > dns->min_latency * LATENCY_FACTOR) 1143 if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor)
1036 dns->send_interval = dns->min_latency * LATENCY_FACTOR; 1144 dns->send_interval = dns->min_latency * conf.dns_overlap_factor;
1145
1146 if (dns->send_interval < conf.dns_send_interval)
1147 dns->send_interval = conf.dns_send_interval;
1037 } 1148 }
1038 1149
1039 delete *i; 1150 delete *i;
1040 dns_sndpq.erase (i); 1151 dns_sndpq.erase (i);
1041 1152
… …
1059 ttl |= pkt [offs++] << 16; 1170 ttl |= pkt [offs++] << 16;
1060 ttl |= pkt [offs++] << 8; 1171 ttl |= pkt [offs++] << 8;
1061 ttl |= pkt [offs++]; 1172 ttl |= pkt [offs++];
1062 u16 rdlen = pkt [offs++] << 8; rdlen |= pkt [offs++]; 1173 u16 rdlen = pkt [offs++] << 8; rdlen |= pkt [offs++];
1063 1174
1064 if (qtype == RR_TYPE_NULL || qtype == RR_TYPE_TXT) 1175 if (qtype == RR_TYPE_NULL || qtype == RR_TYPE_TXT || qtype == dns->cfg.rrtype)
1065 { 1176 {
1066 if (rdlen <= MAXSIZE - offs) 1177 if (rdlen <= MAXSIZE - offs)
1067 { 1178 {
1068 // decode bytes, finally 1179 // decode bytes, finally
1069 1180
… …
1095 { 1206 {
1096 slog (L_TRACE, _("DNS: got tunnel meta command %02x"), ip [3]); 1207 slog (L_TRACE, _("DNS: got tunnel meta command %02x"), ip [3]);
1097 1208
1098 if (ip [3] == CMD_IP_RST) 1209 if (ip [3] == CMD_IP_RST)
1099 { 1210 {
1100 slog (L_DEBUG, _("DNS: got tunnel RST request")); 1211 slog (L_DEBUG, _("DNS: got tunnel RST request."));
1101 1212
1102 delete dns; c->dns = 0; 1213 dns->reset ();
1103
1104 return; 1214 return;
1105 } 1215 }
1106 else if (ip [3] == CMD_IP_SYN) 1216 else if (ip [3] == CMD_IP_SYN)
1107 { 1217 {
1108 slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us.")); 1218 slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us."));
1109 dns->established = true; 1219 dns->established = true;
1110 } 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 }
1111 else if (ip [3] == CMD_IP_REJ) 1236 else if (ip [3] == CMD_IP_REJ)
1112 { 1237 {
1113 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."));
1114 abort (); 1239 dns->tw.start (60.);
1115 } 1240 }
1116 else 1241 else
1242 {
1117 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 }
1118 } 1246 }
1119 else 1247 else
1120 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"),
1121 ip [0], ip [1], ip [2], ip [3]); 1249 ip [0], ip [1], ip [2], ip [3]);
1122 1250
… …
1146 break; 1274 break;
1147 } 1275 }
1148} 1276}
1149 1277
1150void 1278void
1151vpn::dnsv4_ev (io_watcher &w, short revents) 1279vpn::dnsv4_ev (ev::io &w, int revents)
1152{ 1280{
1153 if (revents & EVENT_READ) 1281 if (revents & EV_READ)
1154 { 1282 {
1155 dns_packet *pkt = new dns_packet; 1283 dns_packet *pkt = new dns_packet;
1156 struct sockaddr_in sa; 1284 struct sockaddr_in sa;
1157 socklen_t sa_len = sizeof (sa); 1285 socklen_t sa_len = sizeof (sa);
1158 1286
… …
1174} 1302}
1175 1303
1176bool 1304bool
1177vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) 1305vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
1178{ 1306{
1179 int client = ntohs (si.port); 1307 int client = ntohl (si.host);
1180 1308
1181 assert (0 < client && client <= conns.size ()); 1309 assert (0 < client && client <= conns.size ());
1182 1310
1183 connection *c = conns [client - 1]; 1311 connection *c = conns [client - 1];
1184 1312
1185 if (!c->dns) 1313 if (!c->dns)
1186 c->dns = new dns_connection (c); 1314 c->dns = new dns_connection (c);
1187 1315
1188 if (!c->dns->snddq.put (pkt)) 1316 if (c->dns->snddq.put (pkt))
1189 return false; 1317 {
1318 min_it (c->dns->poll_interval, 0.25);
1319 c->dns->tw ();
1320 }
1190 1321
1191 c->dns->tw.trigger (); 1322 // always return true even if the buffer overflows
1192
1193 return true; 1323 return true;
1194} 1324}
1195 1325
1196void 1326void
1197connection::dnsv4_reset_connection () 1327dns_connection::time_cb (ev::timer &w, int revents)
1198{
1199 //delete dns; dns = 0; //TODO
1200}
1201
1202#define NEXT(w) do { if (next > (w)) next = w; } while (0)
1203
1204void
1205dns_connection::time_cb (time_watcher &w)
1206{ 1328{
1207 // servers have to be polled 1329 // servers have to be polled
1208 if (THISNODE->dns_port) 1330 if (THISNODE->dns_port)
1209 return; 1331 return;
1210 1332
1211 // check for timeouts and (re)transmit 1333 // check for timeouts and (re)transmit
1212 tstamp next = NOW + poll_interval; 1334 tstamp next = 86400 * 365;
1213 dns_snd *send = 0; 1335 dns_snd *send = 0;
1214 1336
1215 for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin (); 1337 for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin ();
1216 i != vpn->dns_sndpq.end (); 1338 i != vpn->dns_sndpq.end ();
1217 ++i) 1339 ++i)
1218 { 1340 {
1219 dns_snd *r = *i; 1341 dns_snd *r = *i;
1220 1342
1221 if (r->timeout <= NOW) 1343 if (r->timeout <= ev_now ())
1222 { 1344 {
1223 if (!send) 1345 if (!send)
1224 { 1346 {
1225 send = r; 1347 send = r;
1226 1348
1227 r->retry++; 1349 r->retry++;
1228 r->timeout = NOW + (r->retry * min_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
1229 1352
1230 // the following code changes the query section a bit, forcing 1353 // the following code changes the query section a bit, forcing
1231 // the forwarder to generate a new request 1354 // the forwarder to generate a new request
1232 if (r->stdhdr) 1355 if (r->stdhdr)
1233 {
1234 //printf ("reencoded header for ID %d retry %d:%d:%d\n", htons (r->pkt->id), THISNODE->id, r->seqno, r->retry);printf ("reencoded header for ID %d retry %d:%d:%d\n", htons (r->pkt->id), THISNODE->id, r->seqno, r->retry);
1235 //encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry); 1356 encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry);
1236 }
1237 } 1357 }
1238 } 1358 }
1239 else 1359 else
1240 NEXT (r->timeout); 1360 min_it (next, r->timeout - ev_now ());
1241 }
1242
1243 if (last_sent + send_interval <= NOW)
1244 { 1361 }
1362
1245 if (!send) 1363 if (!send)
1364 {
1365 // generate a new packet, if wise
1366
1367 if (!established)
1246 { 1368 {
1247 // generate a new packet, if wise 1369 if (vpn->dns_sndpq.empty ())
1248
1249 if (!established)
1250 { 1370 {
1251 if (vpn->dns_sndpq.empty ())
1252 {
1253 send = new dns_snd (this); 1371 send = new dns_snd (this);
1254 1372
1255 cfg.reset (THISNODE->id); 1373 cfg.reset (THISNODE->id);
1374 set_cfg ();
1256 send->gen_syn_req (); 1375 send->gen_syn_req ();
1257 }
1258 } 1376 }
1259 else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING 1377 }
1378 else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding
1260 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) 1379 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
1380 {
1381 if (last_sent + send_interval <= ev_now ())
1261 { 1382 {
1262 //printf ("sending data request etc.\n"); //D 1383 //printf ("sending data request etc.\n"); //D
1263 if (!snddq.empty () || last_received + 1. > NOW) 1384 if (!snddq.empty ())
1264 {
1265 poll_interval = send_interval;
1266 NEXT (NOW + send_interval); 1385 min_it (next, send_interval);
1267 }
1268 1386
1269 send = new dns_snd (this); 1387 send = new dns_snd (this);
1270 send->gen_stream_req (sndseq, snddq); 1388 send->gen_stream_req (sndseq, snddq);
1271 send->timeout = NOW + min_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
1272 1391
1273 sndseq = (sndseq + 1) & SEQNO_MASK; 1392 sndseq = (sndseq + 1) & SEQNO_MASK;
1274 } 1393 }
1275 1394 else
1276 if (send) 1395 min_it (next, last_sent + send_interval - ev_now ());
1277 vpn->dns_sndpq.push_back (send);
1278 } 1396 }
1279 1397
1280 if (send) 1398 if (send)
1281 { 1399 vpn->dns_sndpq.push_back (send);
1282 last_sent = NOW; 1400 }
1401
1402 if (send)
1403 {
1404 last_sent = ev_now ();
1283 sendto (vpn->dnsv4_fd, 1405 sendto (vpn->dnsv4_fd,
1284 send->pkt->at (0), send->pkt->len, 0, 1406 send->pkt->at (0), send->pkt->len, 0,
1285 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); 1407 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
1286 }
1287 } 1408 }
1288 else
1289 NEXT (last_sent + send_interval);
1290 1409
1410 min_it (next, last_sent + max (poll_interval, send_interval) - ev_now ());
1411
1291 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)",
1292 poll_interval, send_interval, next - NOW, 1413 poll_interval, send_interval, next - ev_now (),
1293 vpn->dns_sndpq.size (), snddq.size ()); 1414 vpn->dns_sndpq.size (), snddq.size (),
1294 1415 rcvpq.size ());
1295 // TODO: no idea when this happens, but when next < NOW, we have a problem
1296 if (next < NOW + 0.0001)
1297 next = NOW + 0.1;
1298 1416
1299 w.start (next); 1417 w.start (next);
1300} 1418}
1301 1419
1302#endif 1420#endif

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