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Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.24 by pcg, Mon Mar 7 01:31:26 2005 UTC vs.
Revision 1.57 by root, Thu Oct 6 03:03:09 2022 UTC

1/* 1/*
2 vpn_dns.C -- handle the dns tunnel part of the protocol. 2 vpn_dns.C -- handle the dns tunnel part of the protocol.
3 Copyright (C) 2003-2005 Marc Lehmann <gvpe@schmorp.de> 3 Copyright (C) 2003-2011 Marc Lehmann <gvpe@schmorp.de>
4 4
5 This file is part of GVPE. 5 This file is part of GVPE.
6 6
7 GVPE is free software; you can redistribute it and/or modify 7 GVPE is free software; you can redistribute it and/or modify it
8 it under the terms of the GNU General Public License as published by 8 under the terms of the GNU General Public License as published by the
9 the Free Software Foundation; either version 2 of the License, or 9 Free Software Foundation; either version 3 of the License, or (at your
10 (at your option) any later version. 10 option) any later version.
11 11
12 This program is distributed in the hope that it will be useful, 12 This program is distributed in the hope that it will be useful, but
13 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
15 GNU General Public License for more details. 15 Public License for more details.
16 16
17 You should have received a copy of the GNU General Public License 17 You should have received a copy of the GNU General Public License along
18 along with gvpe; if not, write to the Free Software 18 with this program; if not, see <http://www.gnu.org/licenses/>.
19 Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 19
20 Additional permission under GNU GPL version 3 section 7
21
22 If you modify this Program, or any covered work, by linking or
23 combining it with the OpenSSL project's OpenSSL library (or a modified
24 version of that library), containing parts covered by the terms of the
25 OpenSSL or SSLeay licenses, the licensors of this Program grant you
26 additional permission to convey the resulting work. Corresponding
27 Source for a non-source form of such a combination shall include the
28 source code for the parts of OpenSSL used as well as that of the
29 covered work.
20*/ 30*/
31
32// TODO: EDNS0 option to increase dns mtu?
33// TODO: re-write dns packet parsing/creation using a safe mem-buffer
34// to ensure no buffer overflows or similar problems.
21 35
22#include "config.h" 36#include "config.h"
23 37
24#if ENABLE_DNS 38#if ENABLE_DNS
25 39
… …
38#include <unistd.h> 52#include <unistd.h>
39#include <fcntl.h> 53#include <fcntl.h>
40 54
41#include <map> 55#include <map>
42 56
57#include <cstdio> /* bug in libgmp: gmp.h relies on cstdio being included */
43#include <gmp.h> 58#include <gmp.h>
44 59
45#include "netcompat.h" 60#include "netcompat.h"
46 61
47#include "vpn.h" 62#include "vpn.h"
48 63
49#define MIN_POLL_INTERVAL .02 // how often to poll minimally when the server has data 64#define MIN_POLL_INTERVAL 0.025 // poll at most this often when no data received
50#define MAX_POLL_INTERVAL 6. // how often to poll minimally when the server has no data 65#define MAX_POLL_INTERVAL 1. // how often to poll minimally when the server has no data
51#define ACTIVITY_INTERVAL 5.
52 66
53#define INITIAL_TIMEOUT 0.1 // retry timeouts 67#define INITIAL_TIMEOUT 0.1 // retry timeouts
54#define INITIAL_SYN_TIMEOUT 10. // retry timeout for initial syn 68#define INITIAL_SYN_TIMEOUT 2. // retry timeout for initial syn
55 69
56#define MIN_SEND_INTERVAL 0.01 // wait at least this time between sending requests
57#define MAX_SEND_INTERVAL 0.5 // optimistic? 70#define MAX_SEND_INTERVAL 5. // optimistic?
58 71
59#define MAX_OUTSTANDING 10 // max. outstanding requests
60#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog 72#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog
61#define MAX_BACKLOG (100*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE 73#define MAX_BACKLOG (64*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE
62 74
63#define MAX_DOMAIN_SIZE 220 // 255 is legal limit, but bind doesn't compress well 75#define MAX_DOMAIN_SIZE 235 // 255 is legal limit, but bind doesn't compress well
64// 240 leaves about 4 bytes of server reply data 76// 240 leaves about 4 bytes of server reply data
65// every two request bytes less give room for one reply byte 77// every request byte less give room for two reply bytes
66 78
67#define SEQNO_MASK 0x3fff 79#define SEQNO_MASK 0x3fff
68#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) ) 80#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )
69 81
70#define MAX_LBL_SIZE 63 82#define MAX_LBL_SIZE 63
71#define MAX_PKT_SIZE 512 83#define MAX_PKT_SIZE 512
72 84
73#define RR_TYPE_A 1 85#define RR_TYPE_A 1
74#define RR_TYPE_NULL 10 86#define RR_TYPE_NULL 10
75#define RR_TYPE_TXT 16 87#define RR_TYPE_TXT 16
88#define RR_TYPE_AAAA 28
76#define RR_TYPE_ANY 255 89#define RR_TYPE_ANY 255
77 90
78#define RR_CLASS_IN 1 91#define RR_CLASS_IN 1
79 92
80#define CMD_IP_1 207 93#define CMD_IP_1 207
81#define CMD_IP_2 46 94#define CMD_IP_2 46
82#define CMD_IP_3 236 95#define CMD_IP_3 236
83#define CMD_IP_RST 29 96
84#define CMD_IP_SYN 113 97#define CMD_IP_RST 29 // some error, reset and retry
85#define CMD_IP_REJ 32 98#define CMD_IP_REJ 32 // do not want you
99#define CMD_IP_SYN 113 // connection established
100#define CMD_IP_CSE 213 // connection established, but likely case mismatch
101
102static bool
103is_uc (char c)
104{
105 return 'A' <= c && c <= 'Z';
106}
107
108static bool
109is_lc (char c)
110{
111 return 'a' <= c && c <= 'z';
112}
86 113
87// works for cmaps up to 255 (not 256!) 114// works for cmaps up to 255 (not 256!)
88struct charmap 115struct charmap
89{ 116{
90 enum { INVALID = (u8)255 }; 117 enum { INVALID = (u8)255 };
… …
104 memset (enc, (char) 0, 256); 131 memset (enc, (char) 0, 256);
105 memset (dec, (char)INVALID, 256); 132 memset (dec, (char)INVALID, 256);
106 133
107 for (size = 0; cmap [size]; size++) 134 for (size = 0; cmap [size]; size++)
108 { 135 {
136 char c = cmap [size];
137
109 enc [size] = cmap [size]; 138 enc [size] = c;
110 dec [(u8)enc [size]] = size; 139 dec [(u8)c] = size;
140
141 // allow lowercase/uppercase aliases if possible
142 if (is_uc (c) && dec [c + ('a' - 'A')] == INVALID) dec [c + ('a' - 'A')] = size;
143 if (is_lc (c) && dec [c - ('a' - 'A')] == INVALID) dec [c - ('a' - 'A')] = size;
111 } 144 }
112 145
113 assert (size < 256); 146 assert (size < 256);
114} 147}
115 148
116#define MAX_DEC_LEN 500 149#define MAX_DEC_LEN 500
117#define MAX_ENC_LEN (MAX_DEC_LEN * 2) 150#define MAX_ENC_LEN (MAX_DEC_LEN * 2)
118#define MAX_LIMBS ((MAX_DEC_LEN * 8 + GMP_NUMB_BITS - 1) / GMP_NUMB_BITS) 151#define MAX_LIMBS ((MAX_DEC_LEN * 8 + GMP_NUMB_BITS - 1) / GMP_NUMB_BITS + 1)
119 152
120// ugly. minimum base is 16(!) 153// ugly. minimum base is 16(!)
121struct basecoder 154struct basecoder
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)
137: cmap (cmap) 170: cmap (cmap)
138{ 171{
172 int decn = -1;
173
139 for (unsigned int len = 0; len < MAX_DEC_LEN; ++len) 174 for (unsigned int len = 0; len < MAX_DEC_LEN; ++len)
140 { 175 {
141 u8 src [MAX_DEC_LEN]; 176 u8 src [MAX_DEC_LEN];
142 u8 dst [MAX_ENC_LEN]; 177 u8 dst [MAX_ENC_LEN];
143 178
… …
147 mp_size_t n; 182 mp_size_t n;
148 183
149 n = mpn_set_str (m, src, len, 256); 184 n = mpn_set_str (m, src, len, 256);
150 n = mpn_get_str (dst, this->cmap.size, m, n); 185 n = mpn_get_str (dst, this->cmap.size, m, n);
151 186
152 for (int i = 0; !dst [i]; ++i) 187 for (int i = 0; n && !dst [i]; ++i, --n)
153 n--; 188 ;
154 189
155 enc_len [len] = n; 190 enc_len [len] = n;
191 while (decn < n)
156 dec_len [n] = len; 192 dec_len [++decn] = len;
157 } 193 }
158} 194}
159 195
196unsigned int
160unsigned int basecoder::encode_len (unsigned int len) 197basecoder::encode_len (unsigned int len) const
161{ 198{
162 return enc_len [len]; 199 return enc_len [len];
163} 200}
164 201
202unsigned int
165unsigned int basecoder::decode_len (unsigned int len) 203basecoder::decode_len (unsigned int len) const
166{ 204{
167 while (len && !dec_len [len])
168 --len;
169
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] = {
276 clientid, 314 u8 (seqno),
277 (seqno >> 8) | (retry << 6), 315 u8 ((seqno >> 8) | (retry << 6)),
278 seqno, 316 u8 (clientid),
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)
332 assert (count <= fill); 369 assert (count <= fill);
333 370
334 memmove (data, data + count, fill -= count); 371 memmove (data, data + count, fill -= count);
335} 372}
336 373
374bool
337bool byte_stream::put (u8 *data, unsigned int datalen) 375byte_stream::put (u8 *data, unsigned int datalen)
338{ 376{
339 if (maxsize - fill < datalen) 377 if (maxsize - fill < datalen)
340 return false; 378 return false;
341 379
342 memcpy (this->data + fill, data, datalen); fill += datalen; 380 memcpy (this->data + fill, data, datalen); fill += datalen;
343 381
344 return true; 382 return true;
345} 383}
346 384
385bool
347bool byte_stream::put (vpn_packet *pkt) 386byte_stream::put (vpn_packet *pkt)
348{ 387{
349 if (maxsize - fill < pkt->len + 2) 388 if (maxsize - fill < pkt->len + 2)
350 return false; 389 return false;
351 390
352 data [fill++] = pkt->len >> 8; 391 data [fill++] = pkt->len >> 8;
… …
355 memcpy (data + fill, pkt->at (0), pkt->len); fill += pkt->len; 394 memcpy (data + fill, pkt->at (0), pkt->len); fill += pkt->len;
356 395
357 return true; 396 return true;
358} 397}
359 398
399vpn_packet *
360vpn_packet *byte_stream::get () 400byte_stream::get ()
361{ 401{
362 unsigned int len; 402 unsigned int len;
363 403
364 for (;;) 404 for (;;)
365 { 405 {
406 if (fill < 2)
407 return 0;
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 > %d) stream skipping a byte..."), data [0], data [1], MAXSIZE);
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 r2, r3, r4; 475 u8 r1, r2, r3, r4;
429
430 u8 r5, r6, r7, r8;
431 476
432 void reset (int clientid); 477 void reset (int clientid);
433 bool valid (); 478 bool valid ();
479 u8 get_chksum ();
434}; 480};
435 481
436int dns_cfg::next_uid; 482int dns_cfg::next_uid;
437 483
484void
438void dns_cfg::reset (int clientid) 485dns_cfg::reset (int clientid)
439{ 486{
487 // this ID must result in some mixed-case characters in cdc26-encoding
440 id1 = 'G'; 488 id1 = 'G';
441 id2 = 'V'; 489 id2 = 'V';
442 id3 = 'P'; 490 id3 = 'P';
443 id4 = 'E'; 491 id4 = 'E';
444 492
445 version = 1; 493 version = 2;
446 494
447 rrtype = RR_TYPE_TXT; 495 rrtype = RR_TYPE_TXT;
448 flags = 0; 496 flags = 0;
449 def_ttl = 0; 497 def_ttl = 0;
450 seq_cdc = 26; 498 syn_cdc = 26;
451 req_cdc = 62; 499 hdr_cdc = 36;
500 req_cdc = conf.dns_case_preserving ? 62 : 36;
452 rep_cdc = 0; 501 rep_cdc = 0;
453 max_size = ntohs (MAX_PKT_SIZE); 502 max_size = htons (MAX_PKT_SIZE);
454 client = ntohs (clientid); 503 client = htons (clientid);
455 uid = next_uid++; 504 uid = ++next_uid;
456 505
457 r2 = r3 = r4 = 0; 506 r0 = r1 = r2 = r3 = r4 = 0;
458 r4 = r5 = r6 = r7 = 0;
459}
460 507
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
461bool dns_cfg::valid () 529dns_cfg::valid ()
462{ 530{
531 // although the protocol itself allows for some configurability,
532 // only the following encoding/decoding settings are implemented.
463 return id1 == 'G' 533 return id1 == 'G'
464 && id2 == 'V' 534 && id2 == 'V'
465 && id3 == 'P' 535 && id3 == 'P'
466 && id4 == 'E' 536 && id4 == 'E'
537 && version == 2
467 && seq_cdc == 26 538 && syn_cdc == 26
468 && req_cdc == 62 539 && hdr_cdc == 36
540 && (req_cdc == 36 || req_cdc == 62)
469 && rep_cdc == 0 541 && rep_cdc == 0
470 && version == 1 542 && chksum == get_chksum ();
471 && max_size == ntohs (MAX_PKT_SIZE);
472} 543}
473 544
474struct dns_packet : net_packet 545struct dns_packet : net_packet
475{ 546{
476 u16 id; 547 u16 id;
… …
480 u8 data [MAXSIZE - 6 * 2]; 551 u8 data [MAXSIZE - 6 * 2];
481 552
482 int decode_label (char *data, int size, int &offs); 553 int decode_label (char *data, int size, int &offs);
483}; 554};
484 555
556int
485int dns_packet::decode_label (char *data, int size, int &offs) 557dns_packet::decode_label (char *data, int size, int &offs)
486{ 558{
487 char *orig = data; 559 char *orig = data;
488 560
489 memset (data, 0, size); 561 memset (data, 0, size);
490 562
… …
516 return data - orig; 588 return data - orig;
517} 589}
518 590
519///////////////////////////////////////////////////////////////////////////// 591/////////////////////////////////////////////////////////////////////////////
520 592
593static
594u16 next_id ()
595{
521static u16 dns_id = 0; // TODO: should be per-vpn 596 static u16 dns_id = 0; // TODO: should be per-vpn
522 597
523static u16 next_id () 598#if 1
524{
525 if (!dns_id) 599 if (!dns_id)
526 dns_id = time (0); 600 dns_id = time (0);
527 601
528 // the simplest lsfr with periodicity 65535 i could find 602 // the simplest lsfr with periodicity 65535 i could find
529 dns_id = (dns_id << 1) 603 dns_id = (dns_id << 1)
… …
531 ^ (dns_id >> 2) 605 ^ (dns_id >> 2)
532 ^ (dns_id >> 4) 606 ^ (dns_id >> 4)
533 ^ (dns_id >> 15)) & 1); 607 ^ (dns_id >> 15)) & 1);
534 608
535 return dns_id; 609 return dns_id;
610#else
611 dns_id++;//D
612
613 return htons (dns_id);
614#endif
536} 615}
537 616
538struct dns_rcv; 617struct dns_rcv;
539struct dns_snd; 618struct dns_snd;
540 619
… …
544 struct vpn *vpn; 623 struct vpn *vpn;
545 624
546 dns_cfg cfg; 625 dns_cfg cfg;
547 626
548 bool established; 627 bool established;
628 const basecoder *cdc;
549 629
550 tstamp last_received; 630 tstamp last_received;
551 tstamp last_sent; 631 tstamp last_sent;
552 double last_latency; 632 double min_latency;
553 double poll_interval, send_interval; 633 double poll_interval, send_interval;
554 634
555 vector<dns_rcv *> rcvpq; 635 vector<dns_rcv *> rcvpq;
556 636
557 byte_stream rcvdq; int rcvseq; 637 byte_stream rcvdq; int rcvseq; int repseq;
558 byte_stream snddq; int sndseq; 638 byte_stream snddq; int sndseq;
559 639
560 void time_cb (time_watcher &w); time_watcher tw; 640 inline void time_cb (ev::timer &w, int revents); ev::timer tw;
561 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
562 645
563 dns_connection (connection *c); 646 dns_connection (connection *c);
564 ~dns_connection (); 647 ~dns_connection ();
565}; 648};
566 649
… …
584: dns (dns) 667: dns (dns)
585{ 668{
586 timeout = 0; 669 timeout = 0;
587 retry = 0; 670 retry = 0;
588 seqno = 0; 671 seqno = 0;
589 sent = NOW; 672 sent = ev_now ();
590 stdhdr = false; 673 stdhdr = false;
591 674
592 pkt = new dns_packet; 675 pkt = new dns_packet;
593 676
594 pkt->id = next_id (); 677 pkt->id = next_id ();
… …
597dns_snd::~dns_snd () 680dns_snd::~dns_snd ()
598{ 681{
599 delete pkt; 682 delete pkt;
600} 683}
601 684
685static void
602static void append_domain (dns_packet &pkt, int &offs, const char *domain) 686append_domain (dns_packet &pkt, int &offs, const char *domain)
603{ 687{
604 // add tunnel domain 688 // add tunnel domain
605 for (;;) 689 for (;;)
606 { 690 {
607 const char *end = strchr (domain, '.'); 691 const char *end = strchr (domain, '.');
… …
620 704
621 domain = end + 1; 705 domain = end + 1;
622 } 706 }
623} 707}
624 708
709void
625void dns_snd::gen_stream_req (int seqno, byte_stream &stream) 710dns_snd::gen_stream_req (int seqno, byte_stream &stream)
626{ 711{
627 stdhdr = true; 712 stdhdr = true;
628 this->seqno = seqno; 713 this->seqno = seqno;
629 714
630 timeout = NOW + INITIAL_TIMEOUT; 715 timeout = ev_now () + INITIAL_TIMEOUT;
631 716
632 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 717 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
633 pkt->qdcount = htons (1); 718 pkt->qdcount = htons (1);
634 719
635 int offs = 6*2; 720 int offs = 6*2;
… …
638 // 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
639 724
640 char enc[256], *encp = enc; 725 char enc[256], *encp = enc;
641 encode_header (enc, THISNODE->id, seqno); 726 encode_header (enc, THISNODE->id, seqno);
642 727
643 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);
644 729
645 if (datalen > stream.size ()) 730 if (datalen > stream.size ())
646 datalen = stream.size (); 731 datalen = stream.size ();
647 732
648 int enclen = cdc62.encode (enc + HDRSIZE, stream.begin (), datalen) + HDRSIZE; 733 int enclen = dns->cdc->encode (enc + HDRSIZE, stream.begin (), datalen) + HDRSIZE;
649 stream.remove (datalen); 734 stream.remove (datalen);
650 735
651 while (enclen) 736 while (enclen)
652 { 737 {
653 int lbllen = enclen < MAX_LBL_SIZE ? enclen : MAX_LBL_SIZE; 738 int lbllen = enclen < MAX_LBL_SIZE ? enclen : MAX_LBL_SIZE;
… …
668 (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN; 753 (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN;
669 754
670 pkt->len = offs; 755 pkt->len = offs;
671} 756}
672 757
758void
673void dns_snd::gen_syn_req () 759dns_snd::gen_syn_req ()
674{ 760{
675 timeout = NOW + INITIAL_SYN_TIMEOUT; 761 timeout = ev_now () + INITIAL_SYN_TIMEOUT;
676 762
677 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 763 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
678 pkt->qdcount = htons (1); 764 pkt->qdcount = htons (1);
679 765
680 int offs = 6 * 2; 766 int offs = 6 * 2;
… …
719///////////////////////////////////////////////////////////////////////////// 805/////////////////////////////////////////////////////////////////////////////
720 806
721dns_connection::dns_connection (connection *c) 807dns_connection::dns_connection (connection *c)
722: c (c) 808: c (c)
723, rcvdq (MAX_BACKLOG * 2) 809, rcvdq (MAX_BACKLOG * 2)
724, snddq (MAX_BACKLOG * 2) 810, snddq (MAX_BACKLOG)
725, tw (this, &dns_connection::time_cb)
726{ 811{
812 tw.set<dns_connection, &dns_connection::time_cb> (this);
813
727 vpn = c->vpn; 814 vpn = c->vpn;
728 815
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
729 established = false; 840 established = false;
730 841
731 rcvseq = sndseq = 0; 842 rcvseq = repseq = sndseq = 0;
732 843
733 last_sent = last_received = 0; 844 last_sent = 0;
734 poll_interval = MIN_POLL_INTERVAL; 845 poll_interval = 0.5; // starting here
735 send_interval = 0.5; // starting rate 846 send_interval = 0.5; // starting rate
736 last_latency = INITIAL_TIMEOUT; 847 min_latency = INITIAL_TIMEOUT;
737} 848}
738 849
739dns_connection::~dns_connection () 850void
851dns_connection::set_cfg ()
740{ 852{
741 for (vector<dns_rcv *>::iterator i = rcvpq.begin (); 853 cdc = cfg.req_cdc == 36 ? &cdc36 : &cdc62;
742 i != rcvpq.end ();
743 ++i)
744 delete *i;
745} 854}
746 855
856void
747void dns_connection::receive_rep (dns_rcv *r) 857dns_connection::receive_rep (dns_rcv *r)
748{ 858{
749 if (r->datalen) 859 if (r->datalen)
750 { 860 poll_interval = max (poll_interval * (1. / 1.2), MIN_POLL_INTERVAL);
751 last_received = NOW;
752 tw.trigger ();
753
754 poll_interval = send_interval;
755 }
756 else 861 else
757 { 862 poll_interval = min (poll_interval * 1.1, MAX_POLL_INTERVAL);
758 poll_interval *= 1.5;
759 if (poll_interval > MAX_POLL_INTERVAL)
760 poll_interval = MAX_POLL_INTERVAL;
761 }
762 863
763 rcvpq.push_back (r); 864 rcvpq.push_back (r);
764 865
765 redo: 866 redo:
766 867
767 // find next packet 868 // find next packet
768 for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); ) 869 for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); )
769 if (SEQNO_EQ (rcvseq, (*i)->seqno)) 870 if (SEQNO_EQ (rcvseq, (*i)->seqno))
770 { 871 {
872 //printf ("seqno eq %x %x\n", rcvseq, (*i)->seqno);//D
771 // enter the packet into our input stream 873 // enter the packet into our input stream
772 r = *i; 874 r = *i;
773 875
774 // remove the oldest packet, look forward, as it's oldest first 876 // remove the oldest packet, look forward, as it's oldest first
775 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)
776 if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW)) 878 if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW))
777 { 879 {
880 //printf ("seqno RR %x %x\n", (*j)->seqno, rcvseq - MAX_WINDOW);//D
778 delete *j; 881 delete *j;
779 rcvpq.erase (j); 882 rcvpq.erase (j);
780 break; 883 break;
781 } 884 }
782 885
783 rcvseq = (rcvseq + 1) & SEQNO_MASK; 886 rcvseq = (rcvseq + 1) & SEQNO_MASK;
784 887
785 if (!rcvdq.put (r->data, r->datalen)) 888 if (!rcvdq.put (r->data, r->datalen))
786 { 889 {
890 // MUST never overflow, can be caused by data corruption, TODO
787 slog (L_ERR, "DNS: !rcvdq.put (r->data, r->datalen)"); 891 slog (L_CRIT, "DNS: !rcvdq.put (r->data, r->datalen)");
788 abort (); // MUST never overflow, can be caused by data corruption, TODO 892 reset ();
893 return;
789 } 894 }
790 895
791 while (vpn_packet *pkt = rcvdq.get ()) 896 while (vpn_packet *pkt = rcvdq.get ())
792 { 897 {
793 sockinfo si; 898 sockinfo si;
794 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;
795 900
796 vpn->recv_vpn_packet (pkt, si); 901 vpn->recv_vpn_packet (pkt, si);
797
798 delete pkt; 902 delete pkt;
799 } 903 }
800 904
801 // check for further packets 905 // check for further packets
802 goto redo; 906 goto redo;
… …
845 { 949 {
846 // correct class, domain: parse 950 // correct class, domain: parse
847 int client, seqno; 951 int client, seqno;
848 decode_header (qname, client, seqno); 952 decode_header (qname, client, seqno);
849 953
850 u8 data[MAXSIZE];
851 int datalen = cdc62.decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE));
852
853 if (0 < client && client <= conns.size ()) 954 if (0 < client && client <= conns.size ())
854 { 955 {
855 connection *c = conns [client - 1]; 956 connection *c = conns [client - 1];
856 dns_connection *dns = c->dns; 957 dns_connection *dns = c->dns;
857 dns_rcv *rcv; 958 dns_rcv *rcv;
858 bool in_seq;
859 959
860 if (dns) 960 if (dns)
861 { 961 {
962 u8 data[MAXSIZE];
963 int datalen = dns->cdc->decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE));
964
862 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 (); )
863 if (SEQNO_EQ ((*i)->seqno, seqno)) 966 if (SEQNO_EQ ((*i)->seqno, seqno))
864 { 967 {
865 // already seen that request: simply reply with the cached reply 968 // already seen that request: simply reply with the cached reply
866 dns_rcv *r = *i; 969 dns_rcv *r = *i;
… …
874 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);
875 978
876 goto duplicate_request; 979 goto duplicate_request;
877 } 980 }
878 981
879 in_seq = dns->rcvseq == seqno;
880
881 // new packet, queue 982 // new packet, queue
882 rcv = new dns_rcv (seqno, data, datalen); 983 rcv = new dns_rcv (seqno, data, datalen);
883 dns->receive_rep (rcv); 984 dns->receive_rep (rcv);
884 } 985 }
885 986
… …
892 pkt [offs++] = 0; pkt [offs++] = 0; 993 pkt [offs++] = 0; pkt [offs++] = 0;
893 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
894 995
895 int rdlen_offs = offs += 2; 996 int rdlen_offs = offs += 2;
896 997
897 int dlen = (dns ? ntohs (dns->cfg.max_size) : MAX_PKT_SIZE) - offs;
898 // bind doesn't compress well, so reduce further by one label length
899 dlen -= qlen;
900
901 if (dns) 998 if (dns)
902 { 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
903 // only put data into in-order sequence packets, if 1005 // only put data into in-order sequence packets, if
904 // we receive out-of-order packets we generate empty 1006 // we receive out-of-order packets we generate empty
905 // replies 1007 // replies
906 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)
907 { 1010 {
1011 dns->repseq = seqno;
1012
1013 while (dlen > 1 && !dns->snddq.empty ())
1014 {
908 int txtlen = dlen <= 255 ? dlen - 1 : 255; 1015 int txtlen = dlen <= 255 ? dlen - 1 : 255;
909 1016
910 if (txtlen > dns->snddq.size ()) 1017 if (txtlen > dns->snddq.size ())
911 txtlen = dns->snddq.size (); 1018 txtlen = dns->snddq.size ();
912 1019
913 pkt[offs++] = txtlen; 1020 pkt[offs++] = txtlen;
914 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen); 1021 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
915 offs += txtlen; 1022 offs += txtlen;
916 dns->snddq.remove (txtlen); 1023 dns->snddq.remove (txtlen);
917 1024
918 dlen -= txtlen + 1; 1025 dlen -= txtlen + 1;
1026 }
919 } 1027 }
920 1028
921 // avoid empty TXT rdata 1029 // avoid completely empty TXT rdata
922 if (offs == rdlen_offs) 1030 if (offs == rdlen_offs)
923 pkt[offs++] = 0; 1031 pkt[offs++] = 0;
924 1032
925 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ()); 1033 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
926 } 1034 }
… …
962 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
963 pkt [offs++] = 0; pkt [offs++] = 0; 1071 pkt [offs++] = 0; pkt [offs++] = 0;
964 pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL 1072 pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL
965 pkt [offs++] = 0; pkt [offs++] = 4; // rdlength 1073 pkt [offs++] = 0; pkt [offs++] = 4; // rdlength
966 1074
967 slog (L_INFO, _("DNS: client %d connects"), client);
968
969 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3; 1075 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
970 pkt [offs++] = CMD_IP_REJ; 1076 pkt [offs++] = CMD_IP_REJ;
971 1077
972 if (0 < client && client <= conns.size ()) 1078 if (0 < client && client <= conns.size ())
973 { 1079 {
974 connection *c = conns [client - 1]; 1080 connection *c = conns [client - 1];
975 1081
976 if (cfg.valid ()) 1082 if (cfg.valid ())
977 { 1083 {
978 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));
979 1089
980 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
981 c->dns = new dns_connection (c); 1095 c->dns = new dns_connection (c);
982 c->dns->cfg = cfg; 1096 c->dns->cfg = cfg;
1097 c->dns->set_cfg ();
983 } 1098 }
984 } 1099 }
985 } 1100 }
986 } 1101 }
987 1102
… …
1006 { 1121 {
1007 dns_connection *dns = (*i)->dns; 1122 dns_connection *dns = (*i)->dns;
1008 connection *c = dns->c; 1123 connection *c = dns->c;
1009 int seqno = (*i)->seqno; 1124 int seqno = (*i)->seqno;
1010 u8 data[MAXSIZE], *datap = data; 1125 u8 data[MAXSIZE], *datap = data;
1126 //printf ("rcv pkt %x\n", seqno);//D
1011 1127
1012 if ((*i)->retry) 1128 if ((*i)->retry)
1013 { 1129 {
1014 dns->send_interval *= 1.01; 1130 dns->send_interval *= 1.01;
1015 if (dns->send_interval > MAX_SEND_INTERVAL) 1131 if (dns->send_interval > MAX_SEND_INTERVAL)
1016 dns->send_interval = MAX_SEND_INTERVAL; 1132 dns->send_interval = MAX_SEND_INTERVAL;
1017 } 1133 }
1018 else 1134 else
1019 { 1135 {
1020#if 1 1136#if 0
1021 dns->send_interval *= 0.999; 1137 dns->send_interval *= 0.999;
1022#endif 1138#endif
1023 if (dns->send_interval < MIN_SEND_INTERVAL)
1024 dns->send_interval = MIN_SEND_INTERVAL;
1025
1026 // the latency surely puts an upper bound on 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;
1142
1143 if (latency < dns->min_latency)
1029 dns->last_latency = latency; 1144 dns->min_latency = latency;
1030 1145
1031 if (dns->send_interval > latency) 1146 if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor)
1147 dns->send_interval = dns->min_latency * conf.dns_overlap_factor;
1148
1149 if (dns->send_interval < conf.dns_send_interval)
1032 dns->send_interval = latency; 1150 dns->send_interval = conf.dns_send_interval;
1033 } 1151 }
1034 1152
1035 delete *i; 1153 delete *i;
1036 dns_sndpq.erase (i); 1154 dns_sndpq.erase (i);
1037 1155
… …
1055 ttl |= pkt [offs++] << 16; 1173 ttl |= pkt [offs++] << 16;
1056 ttl |= pkt [offs++] << 8; 1174 ttl |= pkt [offs++] << 8;
1057 ttl |= pkt [offs++]; 1175 ttl |= pkt [offs++];
1058 u16 rdlen = pkt [offs++] << 8; rdlen |= pkt [offs++]; 1176 u16 rdlen = pkt [offs++] << 8; rdlen |= pkt [offs++];
1059 1177
1060 if (qtype == RR_TYPE_NULL || qtype == RR_TYPE_TXT) 1178 if (qtype == RR_TYPE_NULL || qtype == RR_TYPE_TXT || qtype == dns->cfg.rrtype)
1061 { 1179 {
1062 if (rdlen <= MAXSIZE - offs) 1180 if (rdlen <= MAXSIZE - offs)
1063 { 1181 {
1064 // decode bytes, finally 1182 // decode bytes, finally
1065 1183
… …
1091 { 1209 {
1092 slog (L_TRACE, _("DNS: got tunnel meta command %02x"), ip [3]); 1210 slog (L_TRACE, _("DNS: got tunnel meta command %02x"), ip [3]);
1093 1211
1094 if (ip [3] == CMD_IP_RST) 1212 if (ip [3] == CMD_IP_RST)
1095 { 1213 {
1096 slog (L_DEBUG, _("DNS: got tunnel RST request")); 1214 slog (L_DEBUG, _("DNS: got tunnel RST request."));
1097 1215
1098 delete dns; c->dns = 0; 1216 dns->reset ();
1099
1100 return; 1217 return;
1101 } 1218 }
1102 else if (ip [3] == CMD_IP_SYN) 1219 else if (ip [3] == CMD_IP_SYN)
1103 { 1220 {
1104 slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us.")); 1221 slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us."));
1105 dns->established = true; 1222 dns->established = true;
1106 } 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 }
1107 else if (ip [3] == CMD_IP_REJ) 1239 else if (ip [3] == CMD_IP_REJ)
1108 { 1240 {
1109 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."));
1110 abort (); 1242 dns->tw.start (60.);
1111 } 1243 }
1112 else 1244 else
1245 {
1113 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 }
1114 } 1249 }
1115 else 1250 else
1116 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"),
1117 ip [0], ip [1], ip [2], ip [3]); 1252 ip [0], ip [1], ip [2], ip [3]);
1118 1253
… …
1142 break; 1277 break;
1143 } 1278 }
1144} 1279}
1145 1280
1146void 1281void
1147vpn::dnsv4_ev (io_watcher &w, short revents) 1282vpn::dnsv4_ev (ev::io &w, int revents)
1148{ 1283{
1149 if (revents & EVENT_READ) 1284 if (revents & EV_READ)
1150 { 1285 {
1151 dns_packet *pkt = new dns_packet; 1286 dns_packet *pkt = new dns_packet;
1152 struct sockaddr_in sa; 1287 struct sockaddr_in sa;
1153 socklen_t sa_len = sizeof (sa); 1288 socklen_t sa_len = sizeof (sa);
1154 1289
… …
1170} 1305}
1171 1306
1172bool 1307bool
1173vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) 1308vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
1174{ 1309{
1175 int client = ntohs (si.port); 1310 int client = ntohl (si.host);
1176 1311
1177 assert (0 < client && client <= conns.size ()); 1312 assert (0 < client && client <= conns.size ());
1178 1313
1179 connection *c = conns [client - 1]; 1314 connection *c = conns [client - 1];
1180 1315
1181 if (!c->dns) 1316 if (!c->dns)
1182 c->dns = new dns_connection (c); 1317 c->dns = new dns_connection (c);
1183 1318
1184 if (!c->dns->snddq.put (pkt)) 1319 if (c->dns->snddq.put (pkt))
1185 return false; 1320 {
1321 min_it (c->dns->poll_interval, 0.25);
1322 c->dns->tw ();
1323 }
1186 1324
1187 c->dns->tw.trigger (); 1325 // always return true even if the buffer overflows
1188
1189 return true; 1326 return true;
1190} 1327}
1191 1328
1192void 1329void
1193connection::dnsv4_reset_connection () 1330dns_connection::time_cb (ev::timer &w, int revents)
1194{
1195 //delete dns; dns = 0; //TODO
1196}
1197
1198#define NEXT(w) do { if (next > (w)) next = w; } while (0)
1199
1200void
1201dns_connection::time_cb (time_watcher &w)
1202{ 1331{
1203 // servers have to be polled 1332 // servers have to be polled
1204 if (THISNODE->dns_port) 1333 if (THISNODE->dns_port)
1205 return; 1334 return;
1206 1335
1207 // check for timeouts and (re)transmit 1336 // check for timeouts and (re)transmit
1208 tstamp next = NOW + poll_interval; 1337 tstamp next = 86400 * 365;
1209 dns_snd *send = 0; 1338 dns_snd *send = 0;
1210 1339
1211 for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin (); 1340 for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin ();
1212 i != vpn->dns_sndpq.end (); 1341 i != vpn->dns_sndpq.end ();
1213 ++i) 1342 ++i)
1214 { 1343 {
1215 dns_snd *r = *i; 1344 dns_snd *r = *i;
1216 1345
1217 if (r->timeout <= NOW) 1346 if (r->timeout <= ev_now ())
1218 { 1347 {
1219 if (!send) 1348 if (!send)
1220 { 1349 {
1221 send = r; 1350 send = r;
1222 1351
1223 r->retry++; 1352 r->retry++;
1224 r->timeout = NOW + (r->retry * last_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
1225 1355
1226 // the following code changes the query section a bit, forcing 1356 // the following code changes the query section a bit, forcing
1227 // the forwarder to generate a new request 1357 // the forwarder to generate a new request
1228 if (r->stdhdr) 1358 if (r->stdhdr)
1229 {
1230 //printf ("reencoded header for ID %d retry %d:%d:%d\n", htons (r->pkt->id), THISNODE->id, r->seqno, r->retry);printf ("reencoded header for ID %d retry %d:%d:%d\n", htons (r->pkt->id), THISNODE->id, r->seqno, r->retry);
1231 //encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry); 1359 encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry);
1232 }
1233 } 1360 }
1234 } 1361 }
1235 else 1362 else
1236 NEXT (r->timeout); 1363 min_it (next, r->timeout - ev_now ());
1237 }
1238
1239 if (last_sent + send_interval <= NOW)
1240 { 1364 }
1365
1241 if (!send) 1366 if (!send)
1367 {
1368 // generate a new packet, if wise
1369
1370 if (!established)
1242 { 1371 {
1243 // generate a new packet, if wise 1372 if (vpn->dns_sndpq.empty ())
1244
1245 if (!established)
1246 { 1373 {
1247 if (vpn->dns_sndpq.empty ())
1248 {
1249 send = new dns_snd (this); 1374 send = new dns_snd (this);
1250 1375
1251 cfg.reset (THISNODE->id); 1376 cfg.reset (THISNODE->id);
1377 set_cfg ();
1252 send->gen_syn_req (); 1378 send->gen_syn_req ();
1253 }
1254 } 1379 }
1255 else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING 1380 }
1381 else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding
1256 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) 1382 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
1383 {
1384 if (last_sent + send_interval <= ev_now ())
1257 { 1385 {
1258 //printf ("sending data request etc.\n"); //D 1386 //printf ("sending data request etc.\n"); //D
1259 if (!snddq.empty ()) 1387 if (!snddq.empty ())
1260 {
1261 poll_interval = send_interval;
1262 NEXT (NOW + send_interval); 1388 min_it (next, send_interval);
1263 }
1264 1389
1265 send = new dns_snd (this); 1390 send = new dns_snd (this);
1266 send->gen_stream_req (sndseq, snddq); 1391 send->gen_stream_req (sndseq, snddq);
1267 send->timeout = NOW + last_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
1268 1394
1269 sndseq = (sndseq + 1) & SEQNO_MASK; 1395 sndseq = (sndseq + 1) & SEQNO_MASK;
1270 } 1396 }
1271 1397 else
1272 if (send) 1398 min_it (next, last_sent + send_interval - ev_now ());
1273 vpn->dns_sndpq.push_back (send);
1274 } 1399 }
1275 1400
1276 if (send) 1401 if (send)
1277 { 1402 vpn->dns_sndpq.push_back (send);
1278 last_sent = NOW; 1403 }
1404
1405 if (send)
1406 {
1407 last_sent = ev_now ();
1279 sendto (vpn->dnsv4_fd, 1408 sendto (vpn->dnsv4_fd,
1280 send->pkt->at (0), send->pkt->len, 0, 1409 send->pkt->at (0), send->pkt->len, 0,
1281 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); 1410 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
1282 }
1283 } 1411 }
1284 else
1285 NEXT (last_sent + send_interval);
1286 1412
1413 min_it (next, last_sent + max (poll_interval, send_interval) - ev_now ());
1414
1287 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)",
1288 poll_interval, send_interval, next - NOW, 1416 poll_interval, send_interval, next - ev_now (),
1289 vpn->dns_sndpq.size (), snddq.size ()); 1417 vpn->dns_sndpq.size (), snddq.size (),
1290 1418 rcvpq.size ());
1291 // TODO: no idea when this happens, but when next < NOW, we have a problem
1292 if (next < NOW + 0.0001)
1293 next = NOW + 0.1;
1294 1419
1295 w.start (next); 1420 w.start (next);
1296} 1421}
1297 1422
1298#endif 1423#endif

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