ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/gvpe/src/vpn_dns.C
(Generate patch)

Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.25 by pcg, Mon Mar 7 22:24:24 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
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;
… …
358 return true; 397 return true;
359} 398}
360 399
361vpn_packet *byte_stream::get () 400vpn_packet *byte_stream::get ()
362{ 401{
402 if (fill < 2)
403 return 0;
404
363 unsigned int len; 405 unsigned int len;
364 406
365 for (;;) 407 for (;;)
366 { 408 {
367 len = (data [0] << 8) | data [1]; 409 len = (data [0] << 8) | data [1];
368 410
369 if (len <= MAXSIZE || fill < 2) 411 if (len <= MAXSIZE)
370 break; 412 break;
371 413
372 // TODO: handle this better than skipping, e.g. by reset 414 // TODO: handle this better than skipping, e.g. by reset
373 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]);
374 remove (1); 416 remove (1);
375 } 417 }
376 418
377 if (fill < len + 2) 419 if (fill < len + 2)
378 return 0; 420 return 0;
… …
409 451
410struct dns_cfg 452struct dns_cfg
411{ 453{
412 static int next_uid; 454 static int next_uid;
413 455
414 u8 id1, id2, id3, id4; 456 u8 chksum;
457 u8 rrtype;
458 u16 uid; // to make request unique
415 459
416 u8 version; 460 u8 version;
417 u8 flags; 461 u8 flags;
418 u8 rrtype; 462 u16 max_size;
463
464 u8 id1, id2, id3, id4;
465
466 u16 client;
419 u8 def_ttl; 467 u8 def_ttl;
468 u8 r0;
420 469
421 u16 client; 470 u8 syn_cdc; // cdc en/decoder for syn (A?) requests
422 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
423 474
424 u16 max_size;
425 u8 seq_cdc;
426 u8 req_cdc;
427
428 u8 rep_cdc;
429 u8 r2, r3, r4; 475 u8 r1, r2, r3, r4;
430
431 u8 r5, r6, r7, r8;
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 = ntohs (MAX_PKT_SIZE); 502 max_size = htons (MAX_PKT_SIZE);
455 client = ntohs (clientid); 503 client = htons (clientid);
456 uid = next_uid++; 504 uid = ++next_uid;
457 505
458 r2 = r3 = r4 = 0; 506 r0 = r1 = r2 = r3 = r4 = 0;
459 r4 = r5 = r6 = r7 = 0;
460}
461 507
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
462bool dns_cfg::valid () 529dns_cfg::valid ()
463{ 530{
531 // although the protocol itself allows for some configurability,
532 // only the following encoding/decoding settings are implemented.
464 return id1 == 'G' 533 return id1 == 'G'
465 && id2 == 'V' 534 && id2 == 'V'
466 && id3 == 'P' 535 && id3 == 'P'
467 && id4 == 'E' 536 && id4 == 'E'
537 && version == 2
468 && seq_cdc == 26 538 && syn_cdc == 26
469 && req_cdc == 62 539 && hdr_cdc == 36
540 && (req_cdc == 36 || req_cdc == 62)
470 && rep_cdc == 0 541 && rep_cdc == 0
471 && version == 1 542 && chksum == get_chksum ();
472 && max_size == ntohs (MAX_PKT_SIZE);
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 = MIN_POLL_INTERVAL; 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
… …
894 pkt [offs++] = 0; pkt [offs++] = 0; 993 pkt [offs++] = 0; pkt [offs++] = 0;
895 pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL 994 pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL
896 995
897 int rdlen_offs = offs += 2; 996 int rdlen_offs = offs += 2;
898 997
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) 998 if (dns)
904 { 999 {
1000 int dlen = ntohs (dns->cfg.max_size) - offs;
1001
1002 // bind doesn't compress well, so reduce further by one label length
1003 dlen -= qlen;
1004
905 // only put data into in-order sequence packets, if 1005 // only put data into in-order sequence packets, if
906 // we receive out-of-order packets we generate empty 1006 // we receive out-of-order packets we generate empty
907 // replies 1007 // replies
908 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)
909 { 1010 {
1011 dns->repseq = seqno;
1012
1013 while (dlen > 1 && !dns->snddq.empty ())
1014 {
910 int txtlen = dlen <= 255 ? dlen - 1 : 255; 1015 int txtlen = dlen <= 255 ? dlen - 1 : 255;
911 1016
912 if (txtlen > dns->snddq.size ()) 1017 if (txtlen > dns->snddq.size ())
913 txtlen = dns->snddq.size (); 1018 txtlen = dns->snddq.size ();
914 1019
915 pkt[offs++] = txtlen; 1020 pkt[offs++] = txtlen;
916 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen); 1021 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
917 offs += txtlen; 1022 offs += txtlen;
918 dns->snddq.remove (txtlen); 1023 dns->snddq.remove (txtlen);
919 1024
920 dlen -= txtlen + 1; 1025 dlen -= txtlen + 1;
1026 }
921 } 1027 }
922 1028
923 // avoid empty TXT rdata 1029 // avoid completely empty TXT rdata
924 if (offs == rdlen_offs) 1030 if (offs == rdlen_offs)
925 pkt[offs++] = 0; 1031 pkt[offs++] = 0;
926 1032
927 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ()); 1033 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
928 } 1034 }
… …
964 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
965 pkt [offs++] = 0; pkt [offs++] = 0; 1071 pkt [offs++] = 0; pkt [offs++] = 0;
966 pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL 1072 pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL
967 pkt [offs++] = 0; pkt [offs++] = 4; // rdlength 1073 pkt [offs++] = 0; pkt [offs++] = 4; // rdlength
968 1074
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; 1075 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
972 pkt [offs++] = CMD_IP_REJ; 1076 pkt [offs++] = CMD_IP_REJ;
973 1077
974 if (0 < client && client <= conns.size ()) 1078 if (0 < client && client <= conns.size ())
975 { 1079 {
976 connection *c = conns [client - 1]; 1080 connection *c = conns [client - 1];
977 1081
978 if (cfg.valid ()) 1082 if (cfg.valid ())
979 { 1083 {
980 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));
981 1089
982 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
983 c->dns = new dns_connection (c); 1095 c->dns = new dns_connection (c);
984 c->dns->cfg = cfg; 1096 c->dns->cfg = cfg;
1097 c->dns->set_cfg ();
985 } 1098 }
986 } 1099 }
987 } 1100 }
988 } 1101 }
989 1102
… …
1008 { 1121 {
1009 dns_connection *dns = (*i)->dns; 1122 dns_connection *dns = (*i)->dns;
1010 connection *c = dns->c; 1123 connection *c = dns->c;
1011 int seqno = (*i)->seqno; 1124 int seqno = (*i)->seqno;
1012 u8 data[MAXSIZE], *datap = data; 1125 u8 data[MAXSIZE], *datap = data;
1126 //printf ("rcv pkt %x\n", seqno);//D
1013 1127
1014 if ((*i)->retry) 1128 if ((*i)->retry)
1015 { 1129 {
1016 dns->send_interval *= 1.01; 1130 dns->send_interval *= 1.01;
1017 if (dns->send_interval > MAX_SEND_INTERVAL) 1131 if (dns->send_interval > MAX_SEND_INTERVAL)
1018 dns->send_interval = MAX_SEND_INTERVAL; 1132 dns->send_interval = MAX_SEND_INTERVAL;
1019 } 1133 }
1020 else 1134 else
1021 { 1135 {
1022#if 1 1136#if 0
1023 dns->send_interval *= 0.999; 1137 dns->send_interval *= 0.999;
1024#endif 1138#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 1139 // the latency surely puts an upper bound on
1029 // the minimum send interval 1140 // the minimum send interval
1030 double latency = NOW - (*i)->sent; 1141 double latency = ev_now () - (*i)->sent;
1031 1142
1032 if (latency < dns->min_latency) 1143 if (latency < dns->min_latency)
1033 dns->min_latency = latency; 1144 dns->min_latency = latency;
1034 1145
1035 if (dns->send_interval > dns->min_latency * LATENCY_FACTOR) 1146 if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor)
1036 dns->send_interval = dns->min_latency * LATENCY_FACTOR; 1147 dns->send_interval = dns->min_latency * conf.dns_overlap_factor;
1148
1149 if (dns->send_interval < conf.dns_send_interval)
1150 dns->send_interval = conf.dns_send_interval;
1037 } 1151 }
1038 1152
1039 delete *i; 1153 delete *i;
1040 dns_sndpq.erase (i); 1154 dns_sndpq.erase (i);
1041 1155
… …
1059 ttl |= pkt [offs++] << 16; 1173 ttl |= pkt [offs++] << 16;
1060 ttl |= pkt [offs++] << 8; 1174 ttl |= pkt [offs++] << 8;
1061 ttl |= pkt [offs++]; 1175 ttl |= pkt [offs++];
1062 u16 rdlen = pkt [offs++] << 8; rdlen |= pkt [offs++]; 1176 u16 rdlen = pkt [offs++] << 8; rdlen |= pkt [offs++];
1063 1177
1064 if (qtype == RR_TYPE_NULL || qtype == RR_TYPE_TXT) 1178 if (qtype == RR_TYPE_NULL || qtype == RR_TYPE_TXT || qtype == dns->cfg.rrtype)
1065 { 1179 {
1066 if (rdlen <= MAXSIZE - offs) 1180 if (rdlen <= MAXSIZE - offs)
1067 { 1181 {
1068 // decode bytes, finally 1182 // decode bytes, finally
1069 1183
… …
1095 { 1209 {
1096 slog (L_TRACE, _("DNS: got tunnel meta command %02x"), ip [3]); 1210 slog (L_TRACE, _("DNS: got tunnel meta command %02x"), ip [3]);
1097 1211
1098 if (ip [3] == CMD_IP_RST) 1212 if (ip [3] == CMD_IP_RST)
1099 { 1213 {
1100 slog (L_DEBUG, _("DNS: got tunnel RST request")); 1214 slog (L_DEBUG, _("DNS: got tunnel RST request."));
1101 1215
1102 delete dns; c->dns = 0; 1216 dns->reset ();
1103
1104 return; 1217 return;
1105 } 1218 }
1106 else if (ip [3] == CMD_IP_SYN) 1219 else if (ip [3] == CMD_IP_SYN)
1107 { 1220 {
1108 slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us.")); 1221 slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us."));
1109 dns->established = true; 1222 dns->established = true;
1110 } 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 }
1111 else if (ip [3] == CMD_IP_REJ) 1239 else if (ip [3] == CMD_IP_REJ)
1112 { 1240 {
1113 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."));
1114 abort (); 1242 dns->tw.start (60.);
1115 } 1243 }
1116 else 1244 else
1245 {
1117 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 }
1118 } 1249 }
1119 else 1250 else
1120 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"),
1121 ip [0], ip [1], ip [2], ip [3]); 1252 ip [0], ip [1], ip [2], ip [3]);
1122 1253
… …
1146 break; 1277 break;
1147 } 1278 }
1148} 1279}
1149 1280
1150void 1281void
1151vpn::dnsv4_ev (io_watcher &w, short revents) 1282vpn::dnsv4_ev (ev::io &w, int revents)
1152{ 1283{
1153 if (revents & EVENT_READ) 1284 if (revents & EV_READ)
1154 { 1285 {
1155 dns_packet *pkt = new dns_packet; 1286 dns_packet *pkt = new dns_packet;
1156 struct sockaddr_in sa; 1287 struct sockaddr_in sa;
1157 socklen_t sa_len = sizeof (sa); 1288 socklen_t sa_len = sizeof (sa);
1158 1289
… …
1174} 1305}
1175 1306
1176bool 1307bool
1177vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) 1308vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
1178{ 1309{
1179 int client = ntohs (si.port); 1310 int client = ntohl (si.host);
1180 1311
1181 assert (0 < client && client <= conns.size ()); 1312 assert (0 < client && client <= conns.size ());
1182 1313
1183 connection *c = conns [client - 1]; 1314 connection *c = conns [client - 1];
1184 1315
1185 if (!c->dns) 1316 if (!c->dns)
1186 c->dns = new dns_connection (c); 1317 c->dns = new dns_connection (c);
1187 1318
1188 if (!c->dns->snddq.put (pkt)) 1319 if (c->dns->snddq.put (pkt))
1189 return false; 1320 {
1321 min_it (c->dns->poll_interval, 0.25);
1322 c->dns->tw ();
1323 }
1190 1324
1191 c->dns->tw.trigger (); 1325 // always return true even if the buffer overflows
1192
1193 return true; 1326 return true;
1194} 1327}
1195 1328
1196void 1329void
1197connection::dnsv4_reset_connection () 1330dns_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{ 1331{
1207 // servers have to be polled 1332 // servers have to be polled
1208 if (THISNODE->dns_port) 1333 if (THISNODE->dns_port)
1209 return; 1334 return;
1210 1335
1211 // check for timeouts and (re)transmit 1336 // check for timeouts and (re)transmit
1212 tstamp next = NOW + poll_interval; 1337 tstamp next = 86400 * 365;
1213 dns_snd *send = 0; 1338 dns_snd *send = 0;
1214 1339
1215 for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin (); 1340 for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin ();
1216 i != vpn->dns_sndpq.end (); 1341 i != vpn->dns_sndpq.end ();
1217 ++i) 1342 ++i)
1218 { 1343 {
1219 dns_snd *r = *i; 1344 dns_snd *r = *i;
1220 1345
1221 if (r->timeout <= NOW) 1346 if (r->timeout <= ev_now ())
1222 { 1347 {
1223 if (!send) 1348 if (!send)
1224 { 1349 {
1225 send = r; 1350 send = r;
1226 1351
1227 r->retry++; 1352 r->retry++;
1228 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
1229 1355
1230 // the following code changes the query section a bit, forcing 1356 // the following code changes the query section a bit, forcing
1231 // the forwarder to generate a new request 1357 // the forwarder to generate a new request
1232 if (r->stdhdr) 1358 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); 1359 encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry);
1236 }
1237 } 1360 }
1238 } 1361 }
1239 else 1362 else
1240 NEXT (r->timeout); 1363 min_it (next, r->timeout - ev_now ());
1241 }
1242
1243 if (last_sent + send_interval <= NOW)
1244 { 1364 }
1365
1245 if (!send) 1366 if (!send)
1367 {
1368 // generate a new packet, if wise
1369
1370 if (!established)
1246 { 1371 {
1247 // generate a new packet, if wise 1372 if (vpn->dns_sndpq.empty ())
1248
1249 if (!established)
1250 { 1373 {
1251 if (vpn->dns_sndpq.empty ())
1252 {
1253 send = new dns_snd (this); 1374 send = new dns_snd (this);
1254 1375
1255 cfg.reset (THISNODE->id); 1376 cfg.reset (THISNODE->id);
1377 set_cfg ();
1256 send->gen_syn_req (); 1378 send->gen_syn_req ();
1257 }
1258 } 1379 }
1259 else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING 1380 }
1381 else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding
1260 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) 1382 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
1383 {
1384 if (last_sent + send_interval <= ev_now ())
1261 { 1385 {
1262 //printf ("sending data request etc.\n"); //D 1386 //printf ("sending data request etc.\n"); //D
1263 if (!snddq.empty () || last_received + 1. > NOW) 1387 if (!snddq.empty ())
1264 {
1265 poll_interval = send_interval;
1266 NEXT (NOW + send_interval); 1388 min_it (next, send_interval);
1267 }
1268 1389
1269 send = new dns_snd (this); 1390 send = new dns_snd (this);
1270 send->gen_stream_req (sndseq, snddq); 1391 send->gen_stream_req (sndseq, snddq);
1271 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
1272 1394
1273 sndseq = (sndseq + 1) & SEQNO_MASK; 1395 sndseq = (sndseq + 1) & SEQNO_MASK;
1274 } 1396 }
1275 1397 else
1276 if (send) 1398 min_it (next, last_sent + send_interval - ev_now ());
1277 vpn->dns_sndpq.push_back (send);
1278 } 1399 }
1279 1400
1280 if (send) 1401 if (send)
1281 { 1402 vpn->dns_sndpq.push_back (send);
1282 last_sent = NOW; 1403 }
1404
1405 if (send)
1406 {
1407 last_sent = ev_now ();
1283 sendto (vpn->dnsv4_fd, 1408 sendto (vpn->dnsv4_fd,
1284 send->pkt->at (0), send->pkt->len, 0, 1409 send->pkt->at (0), send->pkt->len, 0,
1285 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); 1410 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
1286 }
1287 } 1411 }
1288 else
1289 NEXT (last_sent + send_interval);
1290 1412
1413 min_it (next, last_sent + max (poll_interval, send_interval) - ev_now ());
1414
1291 slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d)", 1415 slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)",
1292 poll_interval, send_interval, next - NOW, 1416 poll_interval, send_interval, next - ev_now (),
1293 vpn->dns_sndpq.size (), snddq.size ()); 1417 vpn->dns_sndpq.size (), snddq.size (),
1294 1418 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 1419
1299 w.start (next); 1420 w.start (next);
1300} 1421}
1301 1422
1302#endif 1423#endif

Diff Legend

– Removed lines
+ Added lines
< Changed lines
> Changed lines