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Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.22 by pcg, Sun Mar 6 21:47:35 2005 UTC vs.
Revision 1.55 by root, Tue Oct 18 11:11:32 2011 UTC

1/* 1/*
2 vpn_dns.C -- handle the dns tunnel part of the protocol. 2 vpn_dns.C -- handle the dns tunnel part of the protocol.
3 Copyright (C) 2003-2005 Marc Lehmann <gvpe@schmorp.de> 3 Copyright (C) 2003-2011 Marc Lehmann <gvpe@schmorp.de>
4 4
5 This file is part of GVPE. 5 This file is part of GVPE.
6 6
7 GVPE is free software; you can redistribute it and/or modify 7 GVPE is free software; you can redistribute it and/or modify it
8 it under the terms of the GNU General Public License as published by 8 under the terms of the GNU General Public License as published by the
9 the Free Software Foundation; either version 2 of the License, or 9 Free Software Foundation; either version 3 of the License, or (at your
10 (at your option) any later version. 10 option) any later version.
11 11
12 This program is distributed in the hope that it will be useful, 12 This program is distributed in the hope that it will be useful, but
13 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
15 GNU General Public License for more details. 15 Public License for more details.
16 16
17 You should have received a copy of the GNU General Public License 17 You should have received a copy of the GNU General Public License along
18 along with gvpe; if not, write to the Free Software 18 with this program; if not, see <http://www.gnu.org/licenses/>.
19 Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 19
20 Additional permission under GNU GPL version 3 section 7
21
22 If you modify this Program, or any covered work, by linking or
23 combining it with the OpenSSL project's OpenSSL library (or a modified
24 version of that library), containing parts covered by the terms of the
25 OpenSSL or SSLeay licenses, the licensors of this Program grant you
26 additional permission to convey the resulting work. Corresponding
27 Source for a non-source form of such a combination shall include the
28 source code for the parts of OpenSSL used as well as that of the
29 covered work.
20*/ 30*/
31
32// TODO: EDNS0 option to increase dns mtu?
33// TODO: re-write dns packet parsing/creation using a safe mem-buffer
34// to ensure no buffer overflows or similar problems.
21 35
22#include "config.h" 36#include "config.h"
23 37
24#if ENABLE_DNS 38#if ENABLE_DNS
25 39
… …
38#include <unistd.h> 52#include <unistd.h>
39#include <fcntl.h> 53#include <fcntl.h>
40 54
41#include <map> 55#include <map>
42 56
57#include <cstdio> /* bug in libgmp: gmp.h relies on cstdio being included */
43#include <gmp.h> 58#include <gmp.h>
44 59
45#include "netcompat.h" 60#include "netcompat.h"
46 61
47#include "vpn.h" 62#include "vpn.h"
48 63
49#define MIN_POLL_INTERVAL .02 // how often to poll minimally when the server has data 64#define MIN_POLL_INTERVAL 0.025 // poll at most this often when no data received
50#define MAX_POLL_INTERVAL 6. // how often to poll minimally when the server has no data 65#define MAX_POLL_INTERVAL 1. // how often to poll minimally when the server has no data
51#define ACTIVITY_INTERVAL 5.
52 66
53#define INITIAL_TIMEOUT 0.1 // retry timeouts 67#define INITIAL_TIMEOUT 0.1 // retry timeouts
54#define INITIAL_SYN_TIMEOUT 10. // retry timeout for initial syn 68#define INITIAL_SYN_TIMEOUT 2. // retry timeout for initial syn
55 69
56#define MIN_SEND_INTERVAL 0.01 // wait at least this time between sending requests
57#define MAX_SEND_INTERVAL 0.5 // optimistic? 70#define MAX_SEND_INTERVAL 5. // optimistic?
58 71
59#define MAX_OUTSTANDING 10 // max. outstanding requests
60#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog 72#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog
61#define MAX_BACKLOG (100*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE 73#define MAX_BACKLOG (64*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE
62 74
63#define MAX_DOMAIN_SIZE 220 // 255 is legal limit, but bind doesn't compress well 75#define MAX_DOMAIN_SIZE 235 // 255 is legal limit, but bind doesn't compress well
64// 240 leaves about 4 bytes of server reply data 76// 240 leaves about 4 bytes of server reply data
65// every two request bytes less give room for one reply byte 77// every request byte less give room for two reply bytes
66 78
67#define SEQNO_MASK 0x3fff 79#define SEQNO_MASK 0x3fff
68#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) ) 80#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )
69 81
70#define MAX_LBL_SIZE 63 82#define MAX_LBL_SIZE 63
71#define MAX_PKT_SIZE 512 83#define MAX_PKT_SIZE 512
72 84
73#define RR_TYPE_A 1 85#define RR_TYPE_A 1
74#define RR_TYPE_NULL 10 86#define RR_TYPE_NULL 10
75#define RR_TYPE_TXT 16 87#define RR_TYPE_TXT 16
88#define RR_TYPE_AAAA 28
76#define RR_TYPE_ANY 255 89#define RR_TYPE_ANY 255
77 90
78#define RR_CLASS_IN 1 91#define RR_CLASS_IN 1
79 92
80#define CMD_IP_1 207 93#define CMD_IP_1 207
81#define CMD_IP_2 46 94#define CMD_IP_2 46
82#define CMD_IP_3 236 95#define CMD_IP_3 236
83#define CMD_IP_RST 29 96
84#define CMD_IP_SYN 113 97#define CMD_IP_RST 29 // some error, reset and retry
85#define CMD_IP_REJ 32 98#define CMD_IP_REJ 32 // do not want you
99#define CMD_IP_SYN 113 // connection established
100#define CMD_IP_CSE 213 // connection established, but likely case mismatch
101
102static bool
103is_uc (char c)
104{
105 return 'A' <= c && c <= 'Z';
106}
107
108static bool
109is_lc (char c)
110{
111 return 'a' <= c && c <= 'z';
112}
86 113
87// works for cmaps up to 255 (not 256!) 114// works for cmaps up to 255 (not 256!)
88struct charmap 115struct charmap
89{ 116{
90 enum { INVALID = (u8)255 }; 117 enum { INVALID = (u8)255 };
… …
104 memset (enc, (char) 0, 256); 131 memset (enc, (char) 0, 256);
105 memset (dec, (char)INVALID, 256); 132 memset (dec, (char)INVALID, 256);
106 133
107 for (size = 0; cmap [size]; size++) 134 for (size = 0; cmap [size]; size++)
108 { 135 {
136 char c = cmap [size];
137
109 enc [size] = cmap [size]; 138 enc [size] = c;
110 dec [(u8)enc [size]] = size; 139 dec [(u8)c] = size;
140
141 // allow lowercase/uppercase aliases if possible
142 if (is_uc (c) && dec [c + ('a' - 'A')] == INVALID) dec [c + ('a' - 'A')] = size;
143 if (is_lc (c) && dec [c - ('a' - 'A')] == INVALID) dec [c - ('a' - 'A')] = size;
111 } 144 }
112 145
113 assert (size < 256); 146 assert (size < 256);
114} 147}
115 148
… …
122{ 155{
123 charmap cmap; 156 charmap cmap;
124 unsigned int enc_len [MAX_DEC_LEN]; 157 unsigned int enc_len [MAX_DEC_LEN];
125 unsigned int dec_len [MAX_ENC_LEN]; 158 unsigned int dec_len [MAX_ENC_LEN];
126 159
127 unsigned int encode_len (unsigned int len); 160 unsigned int encode_len (unsigned int len) const;
128 unsigned int decode_len (unsigned int len); 161 unsigned int decode_len (unsigned int len) const;
129 162
130 unsigned int encode (char *dst, u8 *src, unsigned int len); 163 unsigned int encode (char *dst, u8 *src, unsigned int len) const;
131 unsigned int decode (u8 *dst, char *src, unsigned int len); 164 unsigned int decode (u8 *dst, char *src, unsigned int len) const;
132 165
133 basecoder (const char *cmap); 166 basecoder (const char *cmap);
134}; 167};
135 168
136basecoder::basecoder (const char *cmap) 169basecoder::basecoder (const char *cmap)
… …
155 enc_len [len] = n; 188 enc_len [len] = n;
156 dec_len [n] = len; 189 dec_len [n] = len;
157 } 190 }
158} 191}
159 192
193unsigned int
160unsigned int basecoder::encode_len (unsigned int len) 194basecoder::encode_len (unsigned int len) const
161{ 195{
162 return enc_len [len]; 196 return enc_len [len];
163} 197}
164 198
199unsigned int
165unsigned int basecoder::decode_len (unsigned int len) 200basecoder::decode_len (unsigned int len) const
166{ 201{
167 while (len && !dec_len [len]) 202 while (len && !dec_len [len])
168 --len; 203 --len;
169 204
170 return dec_len [len]; 205 return dec_len [len];
171} 206}
172 207
208unsigned int
173unsigned int basecoder::encode (char *dst, u8 *src, unsigned int len) 209basecoder::encode (char *dst, u8 *src, unsigned int len) const
174{ 210{
175 if (!len || len > MAX_DEC_LEN) 211 if (!len || len > MAX_DEC_LEN)
176 return 0; 212 return 0;
177 213
178 int elen = encode_len (len); 214 int elen = encode_len (len);
… …
197 *dst++ = cmap.encode [dst_ [i]]; 233 *dst++ = cmap.encode [dst_ [i]];
198 234
199 return elen; 235 return elen;
200} 236}
201 237
238unsigned int
202unsigned int basecoder::decode (u8 *dst, char *src, unsigned int len) 239basecoder::decode (u8 *dst, char *src, unsigned int len) const
203{ 240{
204 if (!len || len > MAX_ENC_LEN) 241 if (!len || len > MAX_ENC_LEN)
205 return 0; 242 return 0;
206 243
207 u8 src_ [MAX_ENC_LEN]; 244 u8 src_ [MAX_ENC_LEN];
… …
256 } 293 }
257 abort (); 294 abort ();
258} 295}
259#endif 296#endif
260 297
261//static basecoder cdc64 ("_dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI-");
262//static basecoder cdc63 ("_dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI");
263static basecoder cdc62 ("dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI"); 298static basecoder cdc62 ("dDpPhHzZrR06QqMmjJkKBb34TtSsvVlL81xXaAeEFf92WwGgYyoO57UucCNniI"); // a-zA-Z0-9
264//static basecoder cdc36 ("dphzr06qmjkb34tsvl81xaef92wgyo57ucni"); // unused as of yet 299static basecoder cdc36 ("dPhZr06QmJkB34tSvL81xAeF92wGyO57uCnI"); // a-z0-9 for case-changers
265static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO"); 300static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyOuCnI"); // a-z
266 301
267///////////////////////////////////////////////////////////////////////////// 302/////////////////////////////////////////////////////////////////////////////
268 303
269#define HDRSIZE 6 304#define HDRSIZE 5
270 305
306inline void
271inline void encode_header (char *data, int clientid, int seqno, int retry = 0) 307encode_header (char *data, int clientid, int seqno, int retry = 0)
272{ 308{
309 assert (clientid < 256);
310
273 seqno &= SEQNO_MASK; 311 seqno &= SEQNO_MASK;
274 312
275 u8 hdr[3] = { 313 u8 hdr[3] = {
314 seqno,
315 (seqno >> 8) | (retry << 6),
276 clientid, 316 clientid,
277 (seqno >> 8) | (retry << 6),
278 seqno,
279 }; 317 };
280 318
281 assert (clientid < 256);
282
283 cdc26.encode (data, hdr, 3); 319 cdc36.encode (data, hdr, 3);
284} 320}
285 321
322inline void
286inline void decode_header (char *data, int &clientid, int &seqno) 323decode_header (char *data, int &clientid, int &seqno)
287{ 324{
288 u8 hdr[3]; 325 u8 hdr[3];
289 326
290 cdc26.decode (hdr, data, HDRSIZE); 327 cdc36.decode (hdr, data, HDRSIZE);
291 328
292 clientid = hdr[0]; 329 clientid = hdr[2];
293 seqno = ((hdr[1] << 8) | hdr[2]) & SEQNO_MASK; 330 seqno = ((hdr[1] << 8) | hdr[0]) & SEQNO_MASK;
294} 331}
295 332
296///////////////////////////////////////////////////////////////////////////// 333/////////////////////////////////////////////////////////////////////////////
297 334
298struct byte_stream 335struct byte_stream
… …
324byte_stream::~byte_stream () 361byte_stream::~byte_stream ()
325{ 362{
326 delete data; 363 delete data;
327} 364}
328 365
366void
329void byte_stream::remove (int count) 367byte_stream::remove (int count)
330{ 368{
331 if (count > fill) 369 if (count > fill)
332 assert (count <= fill); 370 assert (count <= fill);
333 371
334 memmove (data, data + count, fill -= count); 372 memmove (data, data + count, fill -= count);
335} 373}
336 374
375bool
337bool byte_stream::put (u8 *data, unsigned int datalen) 376byte_stream::put (u8 *data, unsigned int datalen)
338{ 377{
339 if (maxsize - fill < datalen) 378 if (maxsize - fill < datalen)
340 return false; 379 return false;
341 380
342 memcpy (this->data + fill, data, datalen); fill += datalen; 381 memcpy (this->data + fill, data, datalen); fill += datalen;
343 382
344 return true; 383 return true;
345} 384}
346 385
386bool
347bool byte_stream::put (vpn_packet *pkt) 387byte_stream::put (vpn_packet *pkt)
348{ 388{
349 if (maxsize - fill < pkt->len + 2) 389 if (maxsize - fill < pkt->len + 2)
350 return false; 390 return false;
351 391
352 data [fill++] = pkt->len >> 8; 392 data [fill++] = pkt->len >> 8;
… …
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) stream skipping a byte..."), data [0], data [1]);
373 remove (1); 416 remove (1);
374 } 417 }
375 418
376 if (fill < len + 2) 419 if (fill < len + 2)
377 return 0; 420 return 0;
… …
408 451
409struct dns_cfg 452struct dns_cfg
410{ 453{
411 static int next_uid; 454 static int next_uid;
412 455
456 u8 chksum;
457 u8 rrtype;
458 u16 uid; // to make request unique
459
460 u8 version;
461 u8 flags;
462 u16 max_size;
463
413 u8 id1, id2, id3, id4; 464 u8 id1, id2, id3, id4;
414 u8 version; 465
415 u8 rrtype; 466 u16 client;
416 u8 flags;
417 u8 def_ttl; 467 u8 def_ttl;
418 u8 rcv_cdc; 468 u8 r0;
419 u8 snd_cdc;
420 u16 max_size;
421 u16 client;
422 u16 uid; // to make request unique
423 469
424 u8 reserved[8]; 470 u8 syn_cdc; // cdc en/decoder for syn (A?) requests
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
474
475 u8 r1, r2, r3, r4;
425 476
426 void reset (int clientid); 477 void reset (int clientid);
427 bool valid (); 478 bool valid ();
479 u8 get_chksum ();
428}; 480};
429 481
430int dns_cfg::next_uid; 482int dns_cfg::next_uid;
431 483
484void
432void dns_cfg::reset (int clientid) 485dns_cfg::reset (int clientid)
433{ 486{
487 // this ID must result in some mixed-case characters in cdc26-encoding
434 id1 = 'G'; 488 id1 = 'G';
435 id2 = 'V'; 489 id2 = 'V';
436 id3 = 'P'; 490 id3 = 'P';
437 id4 = 'E'; 491 id4 = 'E';
438 492
439 version = 1; 493 version = 2;
440 494
441 rrtype = RR_TYPE_TXT; 495 rrtype = RR_TYPE_TXT;
442 flags = 0; 496 flags = 0;
443 def_ttl = 1; 497 def_ttl = 0;
444 rcv_cdc = 0;
445 snd_cdc = 62; 498 syn_cdc = 26;
499 hdr_cdc = 36;
500 req_cdc = conf.dns_case_preserving ? 62 : 36;
501 rep_cdc = 0;
446 max_size = ntohs (MAX_PKT_SIZE); 502 max_size = htons (MAX_PKT_SIZE);
447 client = ntohs (clientid); 503 client = htons (clientid);
448 uid = next_uid++; 504 uid = ++next_uid;
449 505
450 memset (reserved, 0, 8); 506 r0 = r1 = r2 = r3 = r4 = 0;
451}
452 507
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
453bool dns_cfg::valid () 529dns_cfg::valid ()
454{ 530{
531 // although the protocol itself allows for some configurability,
532 // only the following encoding/decoding settings are implemented.
455 return id1 == 'G' 533 return id1 == 'G'
456 && id2 == 'V' 534 && id2 == 'V'
457 && id3 == 'P' 535 && id3 == 'P'
458 && id4 == 'E' 536 && id4 == 'E'
459 && version == 1 537 && version == 2
460 && flags == 0
461 && rcv_cdc == 0
462 && snd_cdc == 62 538 && syn_cdc == 26
463 && max_size == ntohs (MAX_PKT_SIZE); 539 && hdr_cdc == 36
540 && (req_cdc == 36 || req_cdc == 62)
541 && rep_cdc == 0
542 && chksum == get_chksum ();
464} 543}
465 544
466struct dns_packet : net_packet 545struct dns_packet : net_packet
467{ 546{
468 u16 id; 547 u16 id;
469 u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4 548 u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4
470 u16 qdcount, ancount, nscount, arcount; 549 u16 qdcount, ancount, nscount, arcount;
471 550
472 u8 data[MAXSIZE - 6 * 2]; 551 u8 data [MAXSIZE - 6 * 2];
473 552
474 int decode_label (char *data, int size, int &offs); 553 int decode_label (char *data, int size, int &offs);
475}; 554};
476 555
556int
477int dns_packet::decode_label (char *data, int size, int &offs) 557dns_packet::decode_label (char *data, int size, int &offs)
478{ 558{
479 char *orig = data; 559 char *orig = data;
480 560
481 memset (data, 0, size); 561 memset (data, 0, size);
482 562
… …
508 return data - orig; 588 return data - orig;
509} 589}
510 590
511///////////////////////////////////////////////////////////////////////////// 591/////////////////////////////////////////////////////////////////////////////
512 592
593static
594u16 next_id ()
595{
513static u16 dns_id = 0; // TODO: should be per-vpn 596 static u16 dns_id = 0; // TODO: should be per-vpn
514 597
515static u16 next_id () 598#if 1
516{
517 if (!dns_id) 599 if (!dns_id)
518 dns_id = time (0); 600 dns_id = time (0);
519 601
520 // the simplest lsfr with periodicity 65535 i could find 602 // the simplest lsfr with periodicity 65535 i could find
521 dns_id = (dns_id << 1) 603 dns_id = (dns_id << 1)
… …
523 ^ (dns_id >> 2) 605 ^ (dns_id >> 2)
524 ^ (dns_id >> 4) 606 ^ (dns_id >> 4)
525 ^ (dns_id >> 15)) & 1); 607 ^ (dns_id >> 15)) & 1);
526 608
527 return dns_id; 609 return dns_id;
610#else
611 dns_id++;//D
612
613 return htons (dns_id);
614#endif
528} 615}
529 616
530struct dns_rcv; 617struct dns_rcv;
531struct dns_snd; 618struct dns_snd;
532 619
… …
536 struct vpn *vpn; 623 struct vpn *vpn;
537 624
538 dns_cfg cfg; 625 dns_cfg cfg;
539 626
540 bool established; 627 bool established;
628 const basecoder *cdc;
541 629
542 tstamp last_received; 630 tstamp last_received;
543 tstamp last_sent; 631 tstamp last_sent;
544 double last_latency; 632 double min_latency;
545 double poll_interval, send_interval; 633 double poll_interval, send_interval;
546 634
547 vector<dns_rcv *> rcvpq; 635 vector<dns_rcv *> rcvpq;
548 636
549 byte_stream rcvdq; int rcvseq; 637 byte_stream rcvdq; int rcvseq; int repseq;
550 byte_stream snddq; int sndseq; 638 byte_stream snddq; int sndseq;
551 639
552 void time_cb (time_watcher &w); time_watcher tw; 640 inline void time_cb (ev::timer &w, int revents); ev::timer tw;
553 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
554 645
555 dns_connection (connection *c); 646 dns_connection (connection *c);
556 ~dns_connection (); 647 ~dns_connection ();
557}; 648};
558 649
… …
576: dns (dns) 667: dns (dns)
577{ 668{
578 timeout = 0; 669 timeout = 0;
579 retry = 0; 670 retry = 0;
580 seqno = 0; 671 seqno = 0;
581 sent = NOW; 672 sent = ev_now ();
582 stdhdr = false; 673 stdhdr = false;
583 674
584 pkt = new dns_packet; 675 pkt = new dns_packet;
585 676
586 pkt->id = next_id (); 677 pkt->id = next_id ();
… …
589dns_snd::~dns_snd () 680dns_snd::~dns_snd ()
590{ 681{
591 delete pkt; 682 delete pkt;
592} 683}
593 684
685static void
594static void append_domain (dns_packet &pkt, int &offs, const char *domain) 686append_domain (dns_packet &pkt, int &offs, const char *domain)
595{ 687{
596 // add tunnel domain 688 // add tunnel domain
597 for (;;) 689 for (;;)
598 { 690 {
599 const char *end = strchr (domain, '.'); 691 const char *end = strchr (domain, '.');
… …
612 704
613 domain = end + 1; 705 domain = end + 1;
614 } 706 }
615} 707}
616 708
709void
617void dns_snd::gen_stream_req (int seqno, byte_stream &stream) 710dns_snd::gen_stream_req (int seqno, byte_stream &stream)
618{ 711{
619 stdhdr = true; 712 stdhdr = true;
620 this->seqno = seqno; 713 this->seqno = seqno;
621 714
622 timeout = NOW + INITIAL_TIMEOUT; 715 timeout = ev_now () + INITIAL_TIMEOUT;
623 716
624 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 717 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
625 pkt->qdcount = htons (1); 718 pkt->qdcount = htons (1);
626 719
627 int offs = 6*2; 720 int offs = 6*2;
… …
630 // 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
631 724
632 char enc[256], *encp = enc; 725 char enc[256], *encp = enc;
633 encode_header (enc, THISNODE->id, seqno); 726 encode_header (enc, THISNODE->id, seqno);
634 727
635 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);
636 729
637 if (datalen > stream.size ()) 730 if (datalen > stream.size ())
638 datalen = stream.size (); 731 datalen = stream.size ();
639 732
640 int enclen = cdc62.encode (enc + HDRSIZE, stream.begin (), datalen) + HDRSIZE; 733 int enclen = dns->cdc->encode (enc + HDRSIZE, stream.begin (), datalen) + HDRSIZE;
641 stream.remove (datalen); 734 stream.remove (datalen);
642 735
643 while (enclen) 736 while (enclen)
644 { 737 {
645 int lbllen = enclen < MAX_LBL_SIZE ? enclen : MAX_LBL_SIZE; 738 int lbllen = enclen < MAX_LBL_SIZE ? enclen : MAX_LBL_SIZE;
… …
660 (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN; 753 (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN;
661 754
662 pkt->len = offs; 755 pkt->len = offs;
663} 756}
664 757
758void
665void dns_snd::gen_syn_req () 759dns_snd::gen_syn_req ()
666{ 760{
667 timeout = NOW + INITIAL_SYN_TIMEOUT; 761 timeout = ev_now () + INITIAL_SYN_TIMEOUT;
668 762
669 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 763 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
670 pkt->qdcount = htons (1); 764 pkt->qdcount = htons (1);
671 765
672 int offs = 6 * 2; 766 int offs = 6 * 2;
… …
711///////////////////////////////////////////////////////////////////////////// 805/////////////////////////////////////////////////////////////////////////////
712 806
713dns_connection::dns_connection (connection *c) 807dns_connection::dns_connection (connection *c)
714: c (c) 808: c (c)
715, rcvdq (MAX_BACKLOG * 2) 809, rcvdq (MAX_BACKLOG * 2)
716, snddq (MAX_BACKLOG * 2) 810, snddq (MAX_BACKLOG)
717, tw (this, &dns_connection::time_cb)
718{ 811{
812 tw.set<dns_connection, &dns_connection::time_cb> (this);
813
719 vpn = c->vpn; 814 vpn = c->vpn;
720 815
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
721 established = false; 840 established = false;
722 841
723 rcvseq = sndseq = 0; 842 rcvseq = repseq = sndseq = 0;
724 843
725 last_sent = last_received = 0; 844 last_sent = 0;
726 poll_interval = MIN_POLL_INTERVAL; 845 poll_interval = 0.5; // starting here
727 send_interval = 0.5; // starting rate 846 send_interval = 0.5; // starting rate
728 last_latency = INITIAL_TIMEOUT; 847 min_latency = INITIAL_TIMEOUT;
729} 848}
730 849
731dns_connection::~dns_connection () 850void
851dns_connection::set_cfg ()
732{ 852{
733 for (vector<dns_rcv *>::iterator i = rcvpq.begin (); 853 cdc = cfg.req_cdc == 36 ? &cdc36 : &cdc62;
734 i != rcvpq.end ();
735 ++i)
736 delete *i;
737} 854}
738 855
856void
739void dns_connection::receive_rep (dns_rcv *r) 857dns_connection::receive_rep (dns_rcv *r)
740{ 858{
741 if (r->datalen) 859 if (r->datalen)
742 { 860 poll_interval = max (poll_interval * (1. / 1.2), MIN_POLL_INTERVAL);
743 last_received = NOW;
744 tw.trigger ();
745
746 poll_interval = send_interval;
747 }
748 else 861 else
749 { 862 poll_interval = min (poll_interval * 1.1, MAX_POLL_INTERVAL);
750 poll_interval *= 1.5;
751 if (poll_interval > MAX_POLL_INTERVAL)
752 poll_interval = MAX_POLL_INTERVAL;
753 }
754 863
755 rcvpq.push_back (r); 864 rcvpq.push_back (r);
756 865
757 redo: 866 redo:
758 867
759 // find next packet 868 // find next packet
760 for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); ) 869 for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); )
761 if (SEQNO_EQ (rcvseq, (*i)->seqno)) 870 if (SEQNO_EQ (rcvseq, (*i)->seqno))
762 { 871 {
872 //printf ("seqno eq %x %x\n", rcvseq, (*i)->seqno);//D
763 // enter the packet into our input stream 873 // enter the packet into our input stream
764 r = *i; 874 r = *i;
765 875
766 // remove the oldest packet, look forward, as it's oldest first 876 // remove the oldest packet, look forward, as it's oldest first
767 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)
768 if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW)) 878 if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW))
769 { 879 {
880 //printf ("seqno RR %x %x\n", (*j)->seqno, rcvseq - MAX_WINDOW);//D
770 delete *j; 881 delete *j;
771 rcvpq.erase (j); 882 rcvpq.erase (j);
772 break; 883 break;
773 } 884 }
774 885
775 rcvseq = (rcvseq + 1) & SEQNO_MASK; 886 rcvseq = (rcvseq + 1) & SEQNO_MASK;
776 887
777 if (!rcvdq.put (r->data, r->datalen)) 888 if (!rcvdq.put (r->data, r->datalen))
778 { 889 {
890 // MUST never overflow, can be caused by data corruption, TODO
779 slog (L_ERR, "DNS: !rcvdq.put (r->data, r->datalen)"); 891 slog (L_CRIT, "DNS: !rcvdq.put (r->data, r->datalen)");
780 abort (); // MUST never overflow, can be caused by data corruption, TODO 892 reset ();
893 return;
781 } 894 }
782 895
783 while (vpn_packet *pkt = rcvdq.get ()) 896 while (vpn_packet *pkt = rcvdq.get ())
784 { 897 {
785 sockinfo si; 898 sockinfo si;
786 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;
787 900
788 vpn->recv_vpn_packet (pkt, si); 901 vpn->recv_vpn_packet (pkt, si);
789
790 delete pkt; 902 delete pkt;
791 } 903 }
792 904
793 // check for further packets 905 // check for further packets
794 goto redo; 906 goto redo;
… …
805 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR); 917 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR);
806 918
807 if (0 == (flags & (FLAG_RESPONSE | FLAG_OP_MASK)) 919 if (0 == (flags & (FLAG_RESPONSE | FLAG_OP_MASK))
808 && pkt.qdcount == htons (1)) 920 && pkt.qdcount == htons (1))
809 { 921 {
810 char qname[MAXSIZE]; 922 char qname [MAXSIZE];
811 int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs); 923 int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
812 924
813 u16 qtype = pkt [offs++] << 8; qtype |= pkt [offs++]; 925 u16 qtype = pkt [offs++] << 8; qtype |= pkt [offs++];
814 u16 qclass = pkt [offs++] << 8; qclass |= pkt [offs++]; 926 u16 qclass = pkt [offs++] << 8; qclass |= pkt [offs++];
815 927
… …
822 934
823 int dlen = strlen (THISNODE->domain); 935 int dlen = strlen (THISNODE->domain);
824 936
825 if (qclass == RR_CLASS_IN 937 if (qclass == RR_CLASS_IN
826 && qlen > dlen + 1 938 && qlen > dlen + 1
827 && !memcmp (qname + qlen - dlen - 1, THISNODE->domain, dlen)) 939 && !memcmp (qname + qlen - (dlen + 1), THISNODE->domain, dlen))
828 { 940 {
829 // now generate reply 941 // now generate reply
830 pkt.ancount = htons (1); // one answer RR 942 pkt.ancount = htons (1); // one answer RR
831 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_OK); 943 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_OK);
832 944
… …
837 { 949 {
838 // correct class, domain: parse 950 // correct class, domain: parse
839 int client, seqno; 951 int client, seqno;
840 decode_header (qname, client, seqno); 952 decode_header (qname, client, seqno);
841 953
842 u8 data[MAXSIZE];
843 int datalen = cdc62.decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE));
844
845 if (0 < client && client <= conns.size ()) 954 if (0 < client && client <= conns.size ())
846 { 955 {
847 connection *c = conns [client - 1]; 956 connection *c = conns [client - 1];
848 dns_connection *dns = c->dns; 957 dns_connection *dns = c->dns;
849 dns_rcv *rcv; 958 dns_rcv *rcv;
850 bool in_seq;
851 959
852 if (dns) 960 if (dns)
853 { 961 {
962 u8 data[MAXSIZE];
963 int datalen = dns->cdc->decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE));
964
854 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 (); )
855 if (SEQNO_EQ ((*i)->seqno, seqno)) 966 if (SEQNO_EQ ((*i)->seqno, seqno))
856 { 967 {
857 // already seen that request: simply reply with the cached reply 968 // already seen that request: simply reply with the cached reply
858 dns_rcv *r = *i; 969 dns_rcv *r = *i;
… …
866 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);
867 978
868 goto duplicate_request; 979 goto duplicate_request;
869 } 980 }
870 981
871 in_seq = dns->rcvseq == seqno;
872
873 // new packet, queue 982 // new packet, queue
874 rcv = new dns_rcv (seqno, data, datalen); 983 rcv = new dns_rcv (seqno, data, datalen);
875 dns->receive_rep (rcv); 984 dns->receive_rep (rcv);
876 } 985 }
877 986
… …
884 pkt [offs++] = 0; pkt [offs++] = 0; 993 pkt [offs++] = 0; pkt [offs++] = 0;
885 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
886 995
887 int rdlen_offs = offs += 2; 996 int rdlen_offs = offs += 2;
888 997
889 int dlen = (dns ? ntohs (dns->cfg.max_size) : MAX_PKT_SIZE) - offs;
890 // bind doesn't compress well, so reduce further by one label length
891 dlen -= qlen;
892
893 if (dns) 998 if (dns)
894 { 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
895 // only put data into in-order sequence packets, if 1005 // only put data into in-order sequence packets, if
896 // we receive out-of-order packets we generate empty 1006 // we receive out-of-order packets we generate empty
897 // replies 1007 // replies
898 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)
899 { 1010 {
1011 dns->repseq = seqno;
1012
1013 while (dlen > 1 && !dns->snddq.empty ())
1014 {
900 int txtlen = dlen <= 255 ? dlen - 1 : 255; 1015 int txtlen = dlen <= 255 ? dlen - 1 : 255;
901 1016
902 if (txtlen > dns->snddq.size ()) 1017 if (txtlen > dns->snddq.size ())
903 txtlen = dns->snddq.size (); 1018 txtlen = dns->snddq.size ();
904 1019
905 pkt[offs++] = txtlen; 1020 pkt[offs++] = txtlen;
906 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen); 1021 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
907 offs += txtlen; 1022 offs += txtlen;
908 dns->snddq.remove (txtlen); 1023 dns->snddq.remove (txtlen);
909 1024
910 dlen -= txtlen + 1; 1025 dlen -= txtlen + 1;
1026 }
911 } 1027 }
912 1028
913 // avoid empty TXT rdata 1029 // avoid completely empty TXT rdata
914 if (offs == rdlen_offs) 1030 if (offs == rdlen_offs)
915 pkt[offs++] = 0; 1031 pkt[offs++] = 0;
916 1032
917 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ()); 1033 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
918 } 1034 }
… …
954 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
955 pkt [offs++] = 0; pkt [offs++] = 0; 1071 pkt [offs++] = 0; pkt [offs++] = 0;
956 pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL 1072 pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL
957 pkt [offs++] = 0; pkt [offs++] = 4; // rdlength 1073 pkt [offs++] = 0; pkt [offs++] = 4; // rdlength
958 1074
959 slog (L_INFO, _("DNS: client %d tries to connect"), client);
960
961 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;
962 pkt [offs++] = CMD_IP_REJ; 1076 pkt [offs++] = CMD_IP_REJ;
963 1077
964 if (0 < client && client <= conns.size ()) 1078 if (0 < client && client <= conns.size ())
965 { 1079 {
966 connection *c = conns [client - 1]; 1080 connection *c = conns [client - 1];
967 1081
968 if (cfg.valid ()) 1082 if (cfg.valid ())
969 { 1083 {
970 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));
971 1089
972 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
973 c->dns = new dns_connection (c); 1095 c->dns = new dns_connection (c);
974 c->dns->cfg = cfg; 1096 c->dns->cfg = cfg;
1097 c->dns->set_cfg ();
975 } 1098 }
976 } 1099 }
977 } 1100 }
978 } 1101 }
979 1102
… …
998 { 1121 {
999 dns_connection *dns = (*i)->dns; 1122 dns_connection *dns = (*i)->dns;
1000 connection *c = dns->c; 1123 connection *c = dns->c;
1001 int seqno = (*i)->seqno; 1124 int seqno = (*i)->seqno;
1002 u8 data[MAXSIZE], *datap = data; 1125 u8 data[MAXSIZE], *datap = data;
1126 //printf ("rcv pkt %x\n", seqno);//D
1003 1127
1004 if ((*i)->retry) 1128 if ((*i)->retry)
1005 { 1129 {
1006 dns->send_interval *= 1.01; 1130 dns->send_interval *= 1.01;
1007 if (dns->send_interval > MAX_SEND_INTERVAL) 1131 if (dns->send_interval > MAX_SEND_INTERVAL)
1008 dns->send_interval = MAX_SEND_INTERVAL; 1132 dns->send_interval = MAX_SEND_INTERVAL;
1009 } 1133 }
1010 else 1134 else
1011 { 1135 {
1012#if 1 1136#if 0
1013 dns->send_interval *= 0.999; 1137 dns->send_interval *= 0.999;
1014#endif 1138#endif
1015 if (dns->send_interval < MIN_SEND_INTERVAL)
1016 dns->send_interval = MIN_SEND_INTERVAL;
1017
1018 // the latency surely puts an upper bound on 1139 // the latency surely puts an upper bound on
1019 // the minimum send interval 1140 // the minimum send interval
1020 double latency = NOW - (*i)->sent; 1141 double latency = ev_now () - (*i)->sent;
1142
1143 if (latency < dns->min_latency)
1021 dns->last_latency = latency; 1144 dns->min_latency = latency;
1022 1145
1023 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)
1024 dns->send_interval = latency; 1150 dns->send_interval = conf.dns_send_interval;
1025 } 1151 }
1026 1152
1027 delete *i; 1153 delete *i;
1028 dns_sndpq.erase (i); 1154 dns_sndpq.erase (i);
1029 1155
… …
1047 ttl |= pkt [offs++] << 16; 1173 ttl |= pkt [offs++] << 16;
1048 ttl |= pkt [offs++] << 8; 1174 ttl |= pkt [offs++] << 8;
1049 ttl |= pkt [offs++]; 1175 ttl |= pkt [offs++];
1050 u16 rdlen = pkt [offs++] << 8; rdlen |= pkt [offs++]; 1176 u16 rdlen = pkt [offs++] << 8; rdlen |= pkt [offs++];
1051 1177
1052 if (qtype == RR_TYPE_NULL || qtype == RR_TYPE_TXT) 1178 if (qtype == RR_TYPE_NULL || qtype == RR_TYPE_TXT || qtype == dns->cfg.rrtype)
1053 { 1179 {
1054 if (rdlen <= MAXSIZE - offs) 1180 if (rdlen <= MAXSIZE - offs)
1055 { 1181 {
1056 // decode bytes, finally 1182 // decode bytes, finally
1057 1183
… …
1083 { 1209 {
1084 slog (L_TRACE, _("DNS: got tunnel meta command %02x"), ip [3]); 1210 slog (L_TRACE, _("DNS: got tunnel meta command %02x"), ip [3]);
1085 1211
1086 if (ip [3] == CMD_IP_RST) 1212 if (ip [3] == CMD_IP_RST)
1087 { 1213 {
1088 slog (L_DEBUG, _("DNS: got tunnel RST request")); 1214 slog (L_DEBUG, _("DNS: got tunnel RST request."));
1089 1215
1090 delete dns; c->dns = 0; 1216 dns->reset ();
1091
1092 return; 1217 return;
1093 } 1218 }
1094 else if (ip [3] == CMD_IP_SYN) 1219 else if (ip [3] == CMD_IP_SYN)
1095 { 1220 {
1096 slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us.")); 1221 slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us."));
1097 dns->established = true; 1222 dns->established = true;
1098 } 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 }
1099 else if (ip [3] == CMD_IP_REJ) 1239 else if (ip [3] == CMD_IP_REJ)
1100 { 1240 {
1101 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."));
1102 abort (); 1242 dns->tw.start (60.);
1103 } 1243 }
1104 else 1244 else
1245 {
1105 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 }
1106 } 1249 }
1107 else 1250 else
1108 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"),
1109 ip [0], ip [1], ip [2], ip [3]); 1252 ip [0], ip [1], ip [2], ip [3]);
1110 1253
… …
1134 break; 1277 break;
1135 } 1278 }
1136} 1279}
1137 1280
1138void 1281void
1139vpn::dnsv4_ev (io_watcher &w, short revents) 1282vpn::dnsv4_ev (ev::io &w, int revents)
1140{ 1283{
1141 if (revents & EVENT_READ) 1284 if (revents & EV_READ)
1142 { 1285 {
1143 dns_packet *pkt = new dns_packet; 1286 dns_packet *pkt = new dns_packet;
1144 struct sockaddr_in sa; 1287 struct sockaddr_in sa;
1145 socklen_t sa_len = sizeof (sa); 1288 socklen_t sa_len = sizeof (sa);
1146 1289
1147 pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len); 1290 pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len);
1148 1291
1149 if (pkt->len > 0) 1292 if (pkt->len > 0)
1150 { 1293 {
1151 if (THISNODE->dns_port) 1294 if (ntohs (pkt->flags) & FLAG_RESPONSE)
1295 dnsv4_client (*pkt);
1296 else
1152 { 1297 {
1153 dnsv4_server (*pkt); 1298 dnsv4_server (*pkt);
1154 sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len); 1299 sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len);
1155 } 1300 }
1156 else
1157 dnsv4_client (*pkt);
1158 1301
1159 delete pkt; 1302 delete pkt;
1160 } 1303 }
1161 } 1304 }
1162} 1305}
1163 1306
1164bool 1307bool
1165vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) 1308vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
1166{ 1309{
1167 int client = ntohs (si.port); 1310 int client = ntohl (si.host);
1168 1311
1169 assert (0 < client && client <= conns.size ()); 1312 assert (0 < client && client <= conns.size ());
1170 1313
1171 connection *c = conns [client - 1]; 1314 connection *c = conns [client - 1];
1172 1315
1173 if (!c->dns) 1316 if (!c->dns)
1174 c->dns = new dns_connection (c); 1317 c->dns = new dns_connection (c);
1175 1318
1176 if (!c->dns->snddq.put (pkt)) 1319 if (c->dns->snddq.put (pkt))
1177 return false; 1320 {
1321 min_it (c->dns->poll_interval, 0.25);
1322 c->dns->tw ();
1323 }
1178 1324
1179 c->dns->tw.trigger (); 1325 // always return true even if the buffer overflows
1180
1181 return true; 1326 return true;
1182} 1327}
1183 1328
1184void 1329void
1185connection::dnsv4_reset_connection () 1330dns_connection::time_cb (ev::timer &w, int revents)
1186{
1187 //delete dns; dns = 0; //TODO
1188}
1189
1190#define NEXT(w) do { if (next > (w)) next = w; } while (0)
1191
1192void
1193dns_connection::time_cb (time_watcher &w)
1194{ 1331{
1195 // servers have to be polled 1332 // servers have to be polled
1196 if (THISNODE->dns_port) 1333 if (THISNODE->dns_port)
1197 return; 1334 return;
1198 1335
1199 // check for timeouts and (re)transmit 1336 // check for timeouts and (re)transmit
1200 tstamp next = NOW + poll_interval; 1337 tstamp next = 86400 * 365;
1201 dns_snd *send = 0; 1338 dns_snd *send = 0;
1202 1339
1203 for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin (); 1340 for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin ();
1204 i != vpn->dns_sndpq.end (); 1341 i != vpn->dns_sndpq.end ();
1205 ++i) 1342 ++i)
1206 { 1343 {
1207 dns_snd *r = *i; 1344 dns_snd *r = *i;
1208 1345
1209 if (r->timeout <= NOW) 1346 if (r->timeout <= ev_now ())
1210 { 1347 {
1211 if (!send) 1348 if (!send)
1212 { 1349 {
1213 send = r; 1350 send = r;
1214 1351
1215 r->retry++; 1352 r->retry++;
1216 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
1217 1355
1218 // the following code changes the query section a bit, forcing 1356 // the following code changes the query section a bit, forcing
1219 // the forwarder to generate a new request 1357 // the forwarder to generate a new request
1220 if (r->stdhdr) 1358 if (r->stdhdr)
1221 {
1222 //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);
1223 //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);
1224 }
1225 } 1360 }
1226 } 1361 }
1227 else 1362 else
1228 NEXT (r->timeout); 1363 min_it (next, r->timeout - ev_now ());
1229 }
1230
1231 if (last_sent + send_interval <= NOW)
1232 { 1364 }
1365
1233 if (!send) 1366 if (!send)
1367 {
1368 // generate a new packet, if wise
1369
1370 if (!established)
1234 { 1371 {
1235 // generate a new packet, if wise 1372 if (vpn->dns_sndpq.empty ())
1236
1237 if (!established)
1238 { 1373 {
1239 if (vpn->dns_sndpq.empty ())
1240 {
1241 send = new dns_snd (this); 1374 send = new dns_snd (this);
1242 1375
1243 printf ("new conn %p %d\n", this, c->conf->id);//D
1244 cfg.reset (THISNODE->id); 1376 cfg.reset (THISNODE->id);
1377 set_cfg ();
1245 send->gen_syn_req (); 1378 send->gen_syn_req ();
1246 }
1247 } 1379 }
1248 else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING 1380 }
1381 else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding
1249 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) 1382 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
1383 {
1384 if (last_sent + send_interval <= ev_now ())
1250 { 1385 {
1251 //printf ("sending data request etc.\n"); //D 1386 //printf ("sending data request etc.\n"); //D
1252 if (!snddq.empty ()) 1387 if (!snddq.empty ())
1253 {
1254 poll_interval = send_interval;
1255 NEXT (NOW + send_interval); 1388 min_it (next, send_interval);
1256 }
1257 1389
1258 send = new dns_snd (this); 1390 send = new dns_snd (this);
1259 send->gen_stream_req (sndseq, snddq); 1391 send->gen_stream_req (sndseq, snddq);
1260 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
1261 1394
1262 sndseq = (sndseq + 1) & SEQNO_MASK; 1395 sndseq = (sndseq + 1) & SEQNO_MASK;
1263 } 1396 }
1264 1397 else
1265 if (send) 1398 min_it (next, last_sent + send_interval - ev_now ());
1266 vpn->dns_sndpq.push_back (send);
1267 } 1399 }
1268 1400
1269 if (send) 1401 if (send)
1270 { 1402 vpn->dns_sndpq.push_back (send);
1271 last_sent = NOW; 1403 }
1404
1405 if (send)
1406 {
1407 last_sent = ev_now ();
1272 sendto (vpn->dnsv4_fd, 1408 sendto (vpn->dnsv4_fd,
1273 send->pkt->at (0), send->pkt->len, 0, 1409 send->pkt->at (0), send->pkt->len, 0,
1274 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); 1410 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
1275 }
1276 } 1411 }
1277 else
1278 NEXT (last_sent + send_interval);
1279 1412
1413 min_it (next, last_sent + max (poll_interval, send_interval) - ev_now ());
1414
1280 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)",
1281 poll_interval, send_interval, next - NOW, 1416 poll_interval, send_interval, next - ev_now (),
1282 vpn->dns_sndpq.size (), snddq.size ()); 1417 vpn->dns_sndpq.size (), snddq.size (),
1283 1418 rcvpq.size ());
1284 // TODO: no idea when this happens, but when next < NOW, we have a problem
1285 if (next < NOW + 0.0001)
1286 next = NOW + 0.1;
1287 1419
1288 w.start (next); 1420 w.start (next);
1289} 1421}
1290 1422
1291#endif 1423#endif

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