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Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.21 by pcg, Sun Mar 6 21:33:40 2005 UTC vs.
Revision 1.53 by root, Tue Oct 18 10:54:17 2011 UTC

1/* 1/*
2 vpn_dns.C -- handle the dns tunnel part of the protocol. 2 vpn_dns.C -- handle the dns tunnel part of the protocol.
3 Copyright (C) 2003-2005 Marc Lehmann <gvpe@schmorp.de> 3 Copyright (C) 2003-2011 Marc Lehmann <gvpe@schmorp.de>
4 4
5 This file is part of GVPE. 5 This file is part of GVPE.
6 6
7 GVPE is free software; you can redistribute it and/or modify 7 GVPE is free software; you can redistribute it and/or modify it
8 it under the terms of the GNU General Public License as published by 8 under the terms of the GNU General Public License as published by the
9 the Free Software Foundation; either version 2 of the License, or 9 Free Software Foundation; either version 3 of the License, or (at your
10 (at your option) any later version. 10 option) any later version.
11 11
12 This program is distributed in the hope that it will be useful, 12 This program is distributed in the hope that it will be useful, but
13 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
15 GNU General Public License for more details. 15 Public License for more details.
16 16
17 You should have received a copy of the GNU General Public License 17 You should have received a copy of the GNU General Public License along
18 along with gvpe; if not, write to the Free Software 18 with this program; if not, see <http://www.gnu.org/licenses/>.
19 Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 19
20 Additional permission under GNU GPL version 3 section 7
21
22 If you modify this Program, or any covered work, by linking or
23 combining it with the OpenSSL project's OpenSSL library (or a modified
24 version of that library), containing parts covered by the terms of the
25 OpenSSL or SSLeay licenses, the licensors of this Program grant you
26 additional permission to convey the resulting work. Corresponding
27 Source for a non-source form of such a combination shall include the
28 source code for the parts of OpenSSL used as well as that of the
29 covered work.
20*/ 30*/
31
32// TODO: EDNS0 option to increase dns mtu?
33// TODO: re-write dns packet parsing/creation using a safe mem-buffer
34// to ensure no buffer overflows or similar problems.
21 35
22#include "config.h" 36#include "config.h"
23 37
24#if ENABLE_DNS 38#if ENABLE_DNS
25 39
… …
38#include <unistd.h> 52#include <unistd.h>
39#include <fcntl.h> 53#include <fcntl.h>
40 54
41#include <map> 55#include <map>
42 56
57#include <cstdio> /* bug in libgmp: gmp.h relies on cstdio being included */
43#include <gmp.h> 58#include <gmp.h>
44 59
45#include "netcompat.h" 60#include "netcompat.h"
46 61
47#include "vpn.h" 62#include "vpn.h"
48 63
49#define MIN_POLL_INTERVAL .02 // how often to poll minimally when the server has data 64#define MIN_POLL_INTERVAL 0.025 // poll at most this often when no data received
50#define MAX_POLL_INTERVAL 6. // how often to poll minimally when the server has no data 65#define MAX_POLL_INTERVAL 1. // how often to poll minimally when the server has no data
51#define ACTIVITY_INTERVAL 5.
52 66
53#define INITIAL_TIMEOUT 0.1 // retry timeouts 67#define INITIAL_TIMEOUT 0.1 // retry timeouts
54#define INITIAL_SYN_TIMEOUT 10. // retry timeout for initial syn 68#define INITIAL_SYN_TIMEOUT 2. // retry timeout for initial syn
55 69
56#define MIN_SEND_INTERVAL 0.01 // wait at least this time between sending requests
57#define MAX_SEND_INTERVAL 0.5 // optimistic? 70#define MAX_SEND_INTERVAL 5. // optimistic?
58 71
59#define 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;
… …
408 448
409struct dns_cfg 449struct dns_cfg
410{ 450{
411 static int next_uid; 451 static int next_uid;
412 452
453 u8 chksum;
454 u8 rrtype;
455 u16 uid; // to make request unique
456
457 u8 version;
458 u8 flags;
459 u16 max_size;
460
413 u8 id1, id2, id3, id4; 461 u8 id1, id2, id3, id4;
414 u8 version; 462
415 u8 rrtype; 463 u16 client;
416 u8 flags;
417 u8 def_ttl; 464 u8 def_ttl;
418 u8 rcv_cdc; 465 u8 r0;
419 u8 snd_cdc;
420 u16 max_size;
421 u16 client;
422 u16 uid; // to make request unique
423 466
424 u8 reserved[8]; 467 u8 syn_cdc; // cdc en/decoder for syn (A?) requests
468 u8 hdr_cdc; // cdc en/decoder for regular request headers
469 u8 req_cdc; // cdc en/decoder for regular (ANY?) request data
470 u8 rep_cdc; // cdc en/decoder for regular (TXT) replies, 0 == 8 bit encoding
471
472 u8 r1, r2, r3, r4;
425 473
426 void reset (int clientid); 474 void reset (int clientid);
427 bool valid (); 475 bool valid ();
476 u8 get_chksum ();
428}; 477};
429 478
430int dns_cfg::next_uid; 479int dns_cfg::next_uid;
431 480
481void
432void dns_cfg::reset (int clientid) 482dns_cfg::reset (int clientid)
433{ 483{
484 // this ID must result in some mixed-case characters in cdc26-encoding
434 id1 = 'G'; 485 id1 = 'G';
435 id2 = 'V'; 486 id2 = 'V';
436 id3 = 'P'; 487 id3 = 'P';
437 id4 = 'E'; 488 id4 = 'E';
438 489
439 version = 1; 490 version = 2;
440 491
441 rrtype = RR_TYPE_TXT; 492 rrtype = RR_TYPE_TXT;
442 flags = 0; 493 flags = 0;
443 def_ttl = 1; 494 def_ttl = 0;
444 rcv_cdc = 0;
445 snd_cdc = 62; 495 syn_cdc = 26;
496 hdr_cdc = 36;
497 req_cdc = conf.dns_case_preserving ? 62 : 36;
498 rep_cdc = 0;
446 max_size = ntohs (MAX_PKT_SIZE); 499 max_size = htons (MAX_PKT_SIZE);
447 client = ntohs (clientid); 500 client = htons (clientid);
448 uid = next_uid++; 501 uid = ++next_uid;
449 502
450 memset (reserved, 0, 8); 503 r0 = r1 = r2 = r3 = r4 = 0;
451}
452 504
505 chksum = get_chksum ();
506}
507
508// simple but not trivial chksum
509u8
510dns_cfg::get_chksum ()
511{
512 unsigned int sum = 0xff00; // only 16 bits required
513
514 u8 old_chksum = chksum;
515 chksum = 0;
516
517 for (unsigned int i = 0; i < sizeof (*this); ++i)
518 sum += ((u8 *)this)[i] * (i + 1);
519
520 chksum = old_chksum;
521
522 return sum + (sum >> 8);
523}
524
525bool
453bool dns_cfg::valid () 526dns_cfg::valid ()
454{ 527{
528 // although the protocol itself allows for some configurability,
529 // only the following encoding/decoding settings are implemented.
455 return id1 == 'G' 530 return id1 == 'G'
456 && id2 == 'V' 531 && id2 == 'V'
457 && id3 == 'P' 532 && id3 == 'P'
458 && id4 == 'E' 533 && id4 == 'E'
459 && version == 1 534 && version == 2
460 && flags == 0
461 && rcv_cdc == 0
462 && snd_cdc == 62 535 && syn_cdc == 26
463 && max_size == ntohs (MAX_PKT_SIZE); 536 && hdr_cdc == 36
537 && (req_cdc == 36 || req_cdc == 62)
538 && rep_cdc == 0
539 && chksum == get_chksum ();
464} 540}
465 541
466struct dns_packet : net_packet 542struct dns_packet : net_packet
467{ 543{
468 u16 id; 544 u16 id;
469 u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4 545 u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4
470 u16 qdcount, ancount, nscount, arcount; 546 u16 qdcount, ancount, nscount, arcount;
471 547
472 u8 data[MAXSIZE - 6 * 2]; 548 u8 data [MAXSIZE - 6 * 2];
473 549
474 int decode_label (char *data, int size, int &offs); 550 int decode_label (char *data, int size, int &offs);
475}; 551};
476 552
553int
477int dns_packet::decode_label (char *data, int size, int &offs) 554dns_packet::decode_label (char *data, int size, int &offs)
478{ 555{
479 char *orig = data; 556 char *orig = data;
480 557
481 memset (data, 0, size); 558 memset (data, 0, size);
482 559
… …
508 return data - orig; 585 return data - orig;
509} 586}
510 587
511///////////////////////////////////////////////////////////////////////////// 588/////////////////////////////////////////////////////////////////////////////
512 589
590static
591u16 next_id ()
592{
513static u16 dns_id = 0; // TODO: should be per-vpn 593 static u16 dns_id = 0; // TODO: should be per-vpn
514 594
515static u16 next_id () 595#if 1
516{
517 if (!dns_id) 596 if (!dns_id)
518 dns_id = time (0); 597 dns_id = time (0);
519 598
520 // the simplest lsfr with periodicity 65535 i could find 599 // the simplest lsfr with periodicity 65535 i could find
521 dns_id = (dns_id << 1) 600 dns_id = (dns_id << 1)
… …
523 ^ (dns_id >> 2) 602 ^ (dns_id >> 2)
524 ^ (dns_id >> 4) 603 ^ (dns_id >> 4)
525 ^ (dns_id >> 15)) & 1); 604 ^ (dns_id >> 15)) & 1);
526 605
527 return dns_id; 606 return dns_id;
607#else
608 dns_id++;//D
609
610 return htons (dns_id);
611#endif
528} 612}
529 613
530struct dns_rcv; 614struct dns_rcv;
531struct dns_snd; 615struct dns_snd;
532 616
… …
536 struct vpn *vpn; 620 struct vpn *vpn;
537 621
538 dns_cfg cfg; 622 dns_cfg cfg;
539 623
540 bool established; 624 bool established;
625 const basecoder *cdc;
541 626
542 tstamp last_received; 627 tstamp last_received;
543 tstamp last_sent; 628 tstamp last_sent;
544 double last_latency; 629 double min_latency;
545 double poll_interval, send_interval; 630 double poll_interval, send_interval;
546 631
547 vector<dns_rcv *> rcvpq; 632 vector<dns_rcv *> rcvpq;
548 633
549 byte_stream rcvdq; int rcvseq; 634 byte_stream rcvdq; int rcvseq; int repseq;
550 byte_stream snddq; int sndseq; 635 byte_stream snddq; int sndseq;
551 636
552 void time_cb (time_watcher &w); time_watcher tw; 637 inline void time_cb (ev::timer &w, int revents); ev::timer tw;
553 void receive_rep (dns_rcv *r); 638 void receive_rep (dns_rcv *r);
639
640 void reset (); // quite like tcp RST
641 void set_cfg (); // to be called after any cfg changes
554 642
555 dns_connection (connection *c); 643 dns_connection (connection *c);
556 ~dns_connection (); 644 ~dns_connection ();
557}; 645};
558 646
… …
576: dns (dns) 664: dns (dns)
577{ 665{
578 timeout = 0; 666 timeout = 0;
579 retry = 0; 667 retry = 0;
580 seqno = 0; 668 seqno = 0;
581 sent = NOW; 669 sent = ev_now ();
582 stdhdr = false; 670 stdhdr = false;
583 671
584 pkt = new dns_packet; 672 pkt = new dns_packet;
585 673
586 pkt->id = next_id (); 674 pkt->id = next_id ();
… …
589dns_snd::~dns_snd () 677dns_snd::~dns_snd ()
590{ 678{
591 delete pkt; 679 delete pkt;
592} 680}
593 681
682static void
594static void append_domain (dns_packet &pkt, int &offs, const char *domain) 683append_domain (dns_packet &pkt, int &offs, const char *domain)
595{ 684{
596 // add tunnel domain 685 // add tunnel domain
597 for (;;) 686 for (;;)
598 { 687 {
599 const char *end = strchr (domain, '.'); 688 const char *end = strchr (domain, '.');
… …
612 701
613 domain = end + 1; 702 domain = end + 1;
614 } 703 }
615} 704}
616 705
706void
617void dns_snd::gen_stream_req (int seqno, byte_stream &stream) 707dns_snd::gen_stream_req (int seqno, byte_stream &stream)
618{ 708{
619 stdhdr = true; 709 stdhdr = true;
620 this->seqno = seqno; 710 this->seqno = seqno;
621 711
622 timeout = NOW + INITIAL_TIMEOUT; 712 timeout = ev_now () + INITIAL_TIMEOUT;
623 713
624 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 714 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
625 pkt->qdcount = htons (1); 715 pkt->qdcount = htons (1);
626 716
627 int offs = 6*2; 717 int offs = 6*2;
… …
630 // so we need to have space for 2*MAX_DOMAIN_SIZE + header + extra 720 // so we need to have space for 2*MAX_DOMAIN_SIZE + header + extra
631 721
632 char enc[256], *encp = enc; 722 char enc[256], *encp = enc;
633 encode_header (enc, THISNODE->id, seqno); 723 encode_header (enc, THISNODE->id, seqno);
634 724
635 int datalen = cdc62.decode_len (dlen - (dlen + MAX_LBL_SIZE - 1) / MAX_LBL_SIZE - HDRSIZE); 725 int datalen = dns->cdc->decode_len (dlen - (dlen + MAX_LBL_SIZE - 1) / MAX_LBL_SIZE - HDRSIZE);
636 726
637 if (datalen > stream.size ()) 727 if (datalen > stream.size ())
638 datalen = stream.size (); 728 datalen = stream.size ();
639 729
640 int enclen = cdc62.encode (enc + HDRSIZE, stream.begin (), datalen) + HDRSIZE; 730 int enclen = dns->cdc->encode (enc + HDRSIZE, stream.begin (), datalen) + HDRSIZE;
641 stream.remove (datalen); 731 stream.remove (datalen);
642 732
643 while (enclen) 733 while (enclen)
644 { 734 {
645 int lbllen = enclen < MAX_LBL_SIZE ? enclen : MAX_LBL_SIZE; 735 int lbllen = enclen < MAX_LBL_SIZE ? enclen : MAX_LBL_SIZE;
… …
660 (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN; 750 (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN;
661 751
662 pkt->len = offs; 752 pkt->len = offs;
663} 753}
664 754
755void
665void dns_snd::gen_syn_req () 756dns_snd::gen_syn_req ()
666{ 757{
667 timeout = NOW + INITIAL_SYN_TIMEOUT; 758 timeout = ev_now () + INITIAL_SYN_TIMEOUT;
668
669 printf ("send syn\n");//D
670 759
671 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 760 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
672 pkt->qdcount = htons (1); 761 pkt->qdcount = htons (1);
673 762
674 int offs = 6 * 2; 763 int offs = 6 * 2;
… …
713///////////////////////////////////////////////////////////////////////////// 802/////////////////////////////////////////////////////////////////////////////
714 803
715dns_connection::dns_connection (connection *c) 804dns_connection::dns_connection (connection *c)
716: c (c) 805: c (c)
717, rcvdq (MAX_BACKLOG * 2) 806, rcvdq (MAX_BACKLOG * 2)
718, snddq (MAX_BACKLOG * 2) 807, snddq (MAX_BACKLOG)
719, tw (this, &dns_connection::time_cb)
720{ 808{
809 tw.set<dns_connection, &dns_connection::time_cb> (this);
810
721 vpn = c->vpn; 811 vpn = c->vpn;
722 812
813 reset ();
814}
815
816dns_connection::~dns_connection ()
817{
818 reset ();
819}
820
821void
822dns_connection::reset ()
823{
824 while (!rcvpq.empty ())
825 {
826 delete rcvpq.back ();
827 rcvpq.pop_back ();
828 }
829
830 for (int i = vpn->dns_sndpq.size (); i--; )
831 if (vpn->dns_sndpq [i]->dns == this)
832 {
833 vpn->dns_sndpq [i] = vpn->dns_sndpq.back ();
834 vpn->dns_sndpq.pop_back ();
835 }
836
723 established = false; 837 established = false;
724 838
725 rcvseq = sndseq = 0; 839 rcvseq = repseq = sndseq = 0;
726 840
727 last_sent = last_received = 0; 841 last_sent = 0;
728 poll_interval = MIN_POLL_INTERVAL; 842 poll_interval = 0.5; // starting here
729 send_interval = 0.5; // starting rate 843 send_interval = 0.5; // starting rate
730 last_latency = INITIAL_TIMEOUT; 844 min_latency = INITIAL_TIMEOUT;
731} 845}
732 846
733dns_connection::~dns_connection () 847void
848dns_connection::set_cfg ()
734{ 849{
735 for (vector<dns_rcv *>::iterator i = rcvpq.begin (); 850 cdc = cfg.req_cdc == 36 ? &cdc36 : &cdc62;
736 i != rcvpq.end ();
737 ++i)
738 delete *i;
739} 851}
740 852
853void
741void dns_connection::receive_rep (dns_rcv *r) 854dns_connection::receive_rep (dns_rcv *r)
742{ 855{
743 if (r->datalen) 856 if (r->datalen)
744 { 857 poll_interval = max (poll_interval * (1. / 1.2), MIN_POLL_INTERVAL);
745 last_received = NOW;
746 tw.trigger ();
747
748 poll_interval = send_interval;
749 }
750 else 858 else
751 { 859 poll_interval = min (poll_interval * 1.1, MAX_POLL_INTERVAL);
752 poll_interval *= 1.5;
753 if (poll_interval > MAX_POLL_INTERVAL)
754 poll_interval = MAX_POLL_INTERVAL;
755 }
756 860
757 rcvpq.push_back (r); 861 rcvpq.push_back (r);
758 862
759 redo: 863 redo:
760 864
761 // find next packet 865 // find next packet
762 for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); ) 866 for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); )
763 if (SEQNO_EQ (rcvseq, (*i)->seqno)) 867 if (SEQNO_EQ (rcvseq, (*i)->seqno))
764 { 868 {
869 //printf ("seqno eq %x %x\n", rcvseq, (*i)->seqno);//D
765 // enter the packet into our input stream 870 // enter the packet into our input stream
766 r = *i; 871 r = *i;
767 872
768 // remove the oldest packet, look forward, as it's oldest first 873 // remove the oldest packet, look forward, as it's oldest first
769 for (vector<dns_rcv *>::iterator j = rcvpq.begin (); j != rcvpq.end (); ++j) 874 for (vector<dns_rcv *>::iterator j = rcvpq.begin (); j != rcvpq.end (); ++j)
770 if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW)) 875 if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW))
771 { 876 {
877 //printf ("seqno RR %x %x\n", (*j)->seqno, rcvseq - MAX_WINDOW);//D
772 delete *j; 878 delete *j;
773 rcvpq.erase (j); 879 rcvpq.erase (j);
774 break; 880 break;
775 } 881 }
776 882
777 rcvseq = (rcvseq + 1) & SEQNO_MASK; 883 rcvseq = (rcvseq + 1) & SEQNO_MASK;
778 884
779 if (!rcvdq.put (r->data, r->datalen)) 885 if (!rcvdq.put (r->data, r->datalen))
780 { 886 {
887 // MUST never overflow, can be caused by data corruption, TODO
781 slog (L_ERR, "DNS: !rcvdq.put (r->data, r->datalen)"); 888 slog (L_CRIT, "DNS: !rcvdq.put (r->data, r->datalen)");
782 abort (); // MUST never overflow, can be caused by data corruption, TODO 889 reset ();
890 return;
783 } 891 }
784 892
785 while (vpn_packet *pkt = rcvdq.get ()) 893 while (vpn_packet *pkt = rcvdq.get ())
786 { 894 {
787 sockinfo si; 895 sockinfo si;
788 si.host = 0x01010101; si.port = htons (c->conf->id); si.prot = PROT_DNSv4; 896 si.host = htonl (c->conf->id); si.port = 0; si.prot = PROT_DNSv4;
789 897
790 vpn->recv_vpn_packet (pkt, si); 898 vpn->recv_vpn_packet (pkt, si);
791
792 delete pkt; 899 delete pkt;
793 } 900 }
794 901
795 // check for further packets 902 // check for further packets
796 goto redo; 903 goto redo;
… …
807 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR); 914 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR);
808 915
809 if (0 == (flags & (FLAG_RESPONSE | FLAG_OP_MASK)) 916 if (0 == (flags & (FLAG_RESPONSE | FLAG_OP_MASK))
810 && pkt.qdcount == htons (1)) 917 && pkt.qdcount == htons (1))
811 { 918 {
812 char qname[MAXSIZE]; 919 char qname [MAXSIZE];
813 int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs); 920 int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
814 921
815 u16 qtype = pkt [offs++] << 8; qtype |= pkt [offs++]; 922 u16 qtype = pkt [offs++] << 8; qtype |= pkt [offs++];
816 u16 qclass = pkt [offs++] << 8; qclass |= pkt [offs++]; 923 u16 qclass = pkt [offs++] << 8; qclass |= pkt [offs++];
817 924
… …
824 931
825 int dlen = strlen (THISNODE->domain); 932 int dlen = strlen (THISNODE->domain);
826 933
827 if (qclass == RR_CLASS_IN 934 if (qclass == RR_CLASS_IN
828 && qlen > dlen + 1 935 && qlen > dlen + 1
829 && !memcmp (qname + qlen - dlen - 1, THISNODE->domain, dlen)) 936 && !memcmp (qname + qlen - (dlen + 1), THISNODE->domain, dlen))
830 { 937 {
831 // now generate reply 938 // now generate reply
832 pkt.ancount = htons (1); // one answer RR 939 pkt.ancount = htons (1); // one answer RR
833 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_OK); 940 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_OK);
834 941
… …
839 { 946 {
840 // correct class, domain: parse 947 // correct class, domain: parse
841 int client, seqno; 948 int client, seqno;
842 decode_header (qname, client, seqno); 949 decode_header (qname, client, seqno);
843 950
844 u8 data[MAXSIZE];
845 int datalen = cdc62.decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE));
846
847 if (0 < client && client <= conns.size ()) 951 if (0 < client && client <= conns.size ())
848 { 952 {
849 connection *c = conns [client - 1]; 953 connection *c = conns [client - 1];
850 dns_connection *dns = c->dns; 954 dns_connection *dns = c->dns;
851 dns_rcv *rcv; 955 dns_rcv *rcv;
852 bool in_seq;
853 956
854 if (dns) 957 if (dns)
855 { 958 {
959 u8 data[MAXSIZE];
960 int datalen = dns->cdc->decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE));
961
856 for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); ) 962 for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); )
857 if (SEQNO_EQ ((*i)->seqno, seqno)) 963 if (SEQNO_EQ ((*i)->seqno, seqno))
858 { 964 {
859 // already seen that request: simply reply with the cached reply 965 // already seen that request: simply reply with the cached reply
860 dns_rcv *r = *i; 966 dns_rcv *r = *i;
… …
868 memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len); 974 memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len);
869 975
870 goto duplicate_request; 976 goto duplicate_request;
871 } 977 }
872 978
873 in_seq = dns->rcvseq == seqno;
874
875 // new packet, queue 979 // new packet, queue
876 rcv = new dns_rcv (seqno, data, datalen); 980 rcv = new dns_rcv (seqno, data, datalen);
877 dns->receive_rep (rcv); 981 dns->receive_rep (rcv);
878 } 982 }
879 983
… …
886 pkt [offs++] = 0; pkt [offs++] = 0; 990 pkt [offs++] = 0; pkt [offs++] = 0;
887 pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL 991 pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL
888 992
889 int rdlen_offs = offs += 2; 993 int rdlen_offs = offs += 2;
890 994
891 int dlen = (dns ? ntohs (dns->cfg.max_size) : MAX_PKT_SIZE) - offs;
892 // bind doesn't compress well, so reduce further by one label length
893 dlen -= qlen;
894
895 if (dns) 995 if (dns)
896 { 996 {
997 int dlen = ntohs (dns->cfg.max_size) - offs;
998
999 // bind doesn't compress well, so reduce further by one label length
1000 dlen -= qlen;
1001
897 // only put data into in-order sequence packets, if 1002 // only put data into in-order sequence packets, if
898 // we receive out-of-order packets we generate empty 1003 // we receive out-of-order packets we generate empty
899 // replies 1004 // replies
900 while (dlen > 1 && !dns->snddq.empty () && in_seq) 1005 //printf ("%d - %d & %x (=%d) < %d\n", seqno, dns->repseq, SEQNO_MASK, (seqno - dns->repseq) & SEQNO_MASK, MAX_WINDOW);//D
1006 if (((seqno - dns->repseq) & SEQNO_MASK) <= MAX_WINDOW)
901 { 1007 {
1008 dns->repseq = seqno;
1009
1010 while (dlen > 1 && !dns->snddq.empty ())
1011 {
902 int txtlen = dlen <= 255 ? dlen - 1 : 255; 1012 int txtlen = dlen <= 255 ? dlen - 1 : 255;
903 1013
904 if (txtlen > dns->snddq.size ()) 1014 if (txtlen > dns->snddq.size ())
905 txtlen = dns->snddq.size (); 1015 txtlen = dns->snddq.size ();
906 1016
907 pkt[offs++] = txtlen; 1017 pkt[offs++] = txtlen;
908 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen); 1018 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
909 offs += txtlen; 1019 offs += txtlen;
910 dns->snddq.remove (txtlen); 1020 dns->snddq.remove (txtlen);
911 1021
912 dlen -= txtlen + 1; 1022 dlen -= txtlen + 1;
1023 }
913 } 1024 }
914 1025
915 // avoid empty TXT rdata 1026 // avoid completely empty TXT rdata
916 if (offs == rdlen_offs) 1027 if (offs == rdlen_offs)
917 pkt[offs++] = 0; 1028 pkt[offs++] = 0;
918 1029
919 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ()); 1030 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
920 } 1031 }
… …
956 pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class 1067 pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
957 pkt [offs++] = 0; pkt [offs++] = 0; 1068 pkt [offs++] = 0; pkt [offs++] = 0;
958 pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL 1069 pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL
959 pkt [offs++] = 0; pkt [offs++] = 4; // rdlength 1070 pkt [offs++] = 0; pkt [offs++] = 4; // rdlength
960 1071
961 slog (L_INFO, _("DNS: client %d tries to connect"), client);
962
963 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3; 1072 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
964 pkt [offs++] = CMD_IP_REJ; 1073 pkt [offs++] = CMD_IP_REJ;
965 1074
966 if (0 < client && client <= conns.size ()) 1075 if (0 < client && client <= conns.size ())
967 { 1076 {
968 connection *c = conns [client - 1]; 1077 connection *c = conns [client - 1];
969 1078
970 if (cfg.valid ()) 1079 if (cfg.valid ())
971 { 1080 {
972 pkt [offs - 1] = CMD_IP_SYN; 1081 slog (L_INFO, _("DNS: client %d connects (version %d, req_cdc %d)"), client, cfg.version, cfg.req_cdc);
1082
1083 // check for any encoding mismatches - hints at a case problem
1084 char qname2 [MAX_ENC_LEN];
1085 cdc26.encode (qname2, (u8 *)&cfg, sizeof (dns_cfg));
973 1086
974 delete c->dns; 1087 delete c->dns;
1088
1089 pkt [offs - 1] = memcmp (qname, qname2, cdc26.encode_len (sizeof (dns_cfg)))
1090 ? CMD_IP_CSE : CMD_IP_SYN;
1091
975 c->dns = new dns_connection (c); 1092 c->dns = new dns_connection (c);
976 c->dns->cfg = cfg; 1093 c->dns->cfg = cfg;
1094 c->dns->set_cfg ();
977 } 1095 }
978 } 1096 }
979 } 1097 }
980 } 1098 }
981 1099
… …
1000 { 1118 {
1001 dns_connection *dns = (*i)->dns; 1119 dns_connection *dns = (*i)->dns;
1002 connection *c = dns->c; 1120 connection *c = dns->c;
1003 int seqno = (*i)->seqno; 1121 int seqno = (*i)->seqno;
1004 u8 data[MAXSIZE], *datap = data; 1122 u8 data[MAXSIZE], *datap = data;
1123 //printf ("rcv pkt %x\n", seqno);//D
1005 1124
1006 if ((*i)->retry) 1125 if ((*i)->retry)
1007 { 1126 {
1008 dns->send_interval *= 1.01; 1127 dns->send_interval *= 1.01;
1009 if (dns->send_interval > MAX_SEND_INTERVAL) 1128 if (dns->send_interval > MAX_SEND_INTERVAL)
1010 dns->send_interval = MAX_SEND_INTERVAL; 1129 dns->send_interval = MAX_SEND_INTERVAL;
1011 } 1130 }
1012 else 1131 else
1013 { 1132 {
1014#if 1 1133#if 0
1015 dns->send_interval *= 0.999; 1134 dns->send_interval *= 0.999;
1016#endif 1135#endif
1017 if (dns->send_interval < MIN_SEND_INTERVAL)
1018 dns->send_interval = MIN_SEND_INTERVAL;
1019
1020 // the latency surely puts an upper bound on 1136 // the latency surely puts an upper bound on
1021 // the minimum send interval 1137 // the minimum send interval
1022 double latency = NOW - (*i)->sent; 1138 double latency = ev_now () - (*i)->sent;
1139
1140 if (latency < dns->min_latency)
1023 dns->last_latency = latency; 1141 dns->min_latency = latency;
1024 1142
1025 if (dns->send_interval > latency) 1143 if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor)
1144 dns->send_interval = dns->min_latency * conf.dns_overlap_factor;
1145
1146 if (dns->send_interval < conf.dns_send_interval)
1026 dns->send_interval = latency; 1147 dns->send_interval = conf.dns_send_interval;
1027 } 1148 }
1028 1149
1029 delete *i; 1150 delete *i;
1030 dns_sndpq.erase (i); 1151 dns_sndpq.erase (i);
1031 1152
… …
1049 ttl |= pkt [offs++] << 16; 1170 ttl |= pkt [offs++] << 16;
1050 ttl |= pkt [offs++] << 8; 1171 ttl |= pkt [offs++] << 8;
1051 ttl |= pkt [offs++]; 1172 ttl |= pkt [offs++];
1052 u16 rdlen = pkt [offs++] << 8; rdlen |= pkt [offs++]; 1173 u16 rdlen = pkt [offs++] << 8; rdlen |= pkt [offs++];
1053 1174
1054 if (qtype == RR_TYPE_NULL || qtype == RR_TYPE_TXT) 1175 if (qtype == RR_TYPE_NULL || qtype == RR_TYPE_TXT || qtype == dns->cfg.rrtype)
1055 { 1176 {
1056 if (rdlen <= MAXSIZE - offs) 1177 if (rdlen <= MAXSIZE - offs)
1057 { 1178 {
1058 // decode bytes, finally 1179 // decode bytes, finally
1059 1180
… …
1085 { 1206 {
1086 slog (L_TRACE, _("DNS: got tunnel meta command %02x"), ip [3]); 1207 slog (L_TRACE, _("DNS: got tunnel meta command %02x"), ip [3]);
1087 1208
1088 if (ip [3] == CMD_IP_RST) 1209 if (ip [3] == CMD_IP_RST)
1089 { 1210 {
1090 slog (L_DEBUG, _("DNS: got tunnel RST request")); 1211 slog (L_DEBUG, _("DNS: got tunnel RST request."));
1091 1212
1092 delete dns; c->dns = 0; 1213 dns->reset ();
1093
1094 return; 1214 return;
1095 } 1215 }
1096 else if (ip [3] == CMD_IP_SYN) 1216 else if (ip [3] == CMD_IP_SYN)
1097 { 1217 {
1098 slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us.")); 1218 slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us."));
1099 dns->established = true; 1219 dns->established = true;
1100 } 1220 }
1221 else if (ip [3] == CMD_IP_CSE)
1222 {
1223 if (conf.dns_case_preserving)
1224 {
1225 slog (L_INFO, _("DNS: got tunnel CSE reply, globally downgrading to case-insensitive protocol."));
1226 conf.dns_case_preserving = false;
1227 dns->reset ();
1228 return;
1229 }
1230 else
1231 {
1232 slog (L_DEBUG, _("DNS: got tunnel CSE reply, server likes us."));
1233 dns->established = true;
1234 }
1235 }
1101 else if (ip [3] == CMD_IP_REJ) 1236 else if (ip [3] == CMD_IP_REJ)
1102 { 1237 {
1103 slog (L_DEBUG, _("DNS: got tunnel REJ reply, server does not like us, aborting.")); 1238 slog (L_ERR, _("DNS: got tunnel REJ reply, server does not like us."));
1104 abort (); 1239 dns->tw.start (60.);
1105 } 1240 }
1106 else 1241 else
1242 {
1107 slog (L_INFO, _("DNS: got unknown meta command %02x"), ip [3]); 1243 slog (L_INFO, _("DNS: got unknown meta command %02x"), ip [3]);
1244 dns->tw.start (60.);
1245 }
1108 } 1246 }
1109 else 1247 else
1110 slog (L_INFO, _("DNS: got spurious a record %d.%d.%d.%d"), 1248 slog (L_INFO, _("DNS: got spurious a record %d.%d.%d.%d"),
1111 ip [0], ip [1], ip [2], ip [3]); 1249 ip [0], ip [1], ip [2], ip [3]);
1112 1250
… …
1136 break; 1274 break;
1137 } 1275 }
1138} 1276}
1139 1277
1140void 1278void
1141vpn::dnsv4_ev (io_watcher &w, short revents) 1279vpn::dnsv4_ev (ev::io &w, int revents)
1142{ 1280{
1143 if (revents & EVENT_READ) 1281 if (revents & EV_READ)
1144 { 1282 {
1145 dns_packet *pkt = new dns_packet; 1283 dns_packet *pkt = new dns_packet;
1146 struct sockaddr_in sa; 1284 struct sockaddr_in sa;
1147 socklen_t sa_len = sizeof (sa); 1285 socklen_t sa_len = sizeof (sa);
1148 1286
1149 pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len); 1287 pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len);
1150 1288
1151 if (pkt->len > 0) 1289 if (pkt->len > 0)
1152 { 1290 {
1153 if (THISNODE->dns_port) 1291 if (ntohs (pkt->flags) & FLAG_RESPONSE)
1292 dnsv4_client (*pkt);
1293 else
1154 { 1294 {
1155 dnsv4_server (*pkt); 1295 dnsv4_server (*pkt);
1156 sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len); 1296 sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len);
1157 } 1297 }
1158 else
1159 dnsv4_client (*pkt);
1160 1298
1161 delete pkt; 1299 delete pkt;
1162 } 1300 }
1163 } 1301 }
1164} 1302}
1165 1303
1166bool 1304bool
1167vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) 1305vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
1168{ 1306{
1169 int client = ntohs (si.port); 1307 int client = ntohl (si.host);
1170 1308
1171 assert (0 < client && client <= conns.size ()); 1309 assert (0 < client && client <= conns.size ());
1172 1310
1173 connection *c = conns [client - 1]; 1311 connection *c = conns [client - 1];
1174 1312
1175 if (!c->dns) 1313 if (!c->dns)
1176 c->dns = new dns_connection (c); 1314 c->dns = new dns_connection (c);
1177 1315
1178 if (!c->dns->snddq.put (pkt)) 1316 if (c->dns->snddq.put (pkt))
1179 return false; 1317 {
1318 min_it (c->dns->poll_interval, 0.25);
1319 c->dns->tw ();
1320 }
1180 1321
1181 c->dns->tw.trigger (); 1322 // always return true even if the buffer overflows
1182
1183 return true; 1323 return true;
1184} 1324}
1185 1325
1186void 1326void
1187connection::dnsv4_reset_connection () 1327dns_connection::time_cb (ev::timer &w, int revents)
1188{
1189 //delete dns; dns = 0; //TODO
1190}
1191
1192#define NEXT(w) do { if (next > (w)) next = w; } while (0)
1193
1194void
1195dns_connection::time_cb (time_watcher &w)
1196{ 1328{
1197 // servers have to be polled 1329 // servers have to be polled
1198 if (THISNODE->dns_port) 1330 if (THISNODE->dns_port)
1199 return; 1331 return;
1200 1332
1201 // check for timeouts and (re)transmit 1333 // check for timeouts and (re)transmit
1202 tstamp next = NOW + poll_interval; 1334 tstamp next = 86400 * 365;
1203 dns_snd *send = 0; 1335 dns_snd *send = 0;
1204 1336
1205 for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin (); 1337 for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin ();
1206 i != vpn->dns_sndpq.end (); 1338 i != vpn->dns_sndpq.end ();
1207 ++i) 1339 ++i)
1208 { 1340 {
1209 dns_snd *r = *i; 1341 dns_snd *r = *i;
1210 1342
1211 if (r->timeout <= NOW) 1343 if (r->timeout <= ev_now ())
1212 { 1344 {
1213 if (!send) 1345 if (!send)
1214 { 1346 {
1215 send = r; 1347 send = r;
1216 1348
1217 r->retry++; 1349 r->retry++;
1218 r->timeout = NOW + (r->retry * last_latency * 8.); 1350 r->timeout = ev_now () + r->retry * min_latency * conf.dns_timeout_factor;
1351 //printf ("RETRY %x (%d, %f)\n", r->seqno, r->retry, r->timeout - ev_now ());//D
1219 1352
1220 // the following code changes the query section a bit, forcing 1353 // the following code changes the query section a bit, forcing
1221 // the forwarder to generate a new request 1354 // the forwarder to generate a new request
1222 if (r->stdhdr) 1355 if (r->stdhdr)
1223 {
1224 //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);
1225 //encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry); 1356 encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry);
1226 }
1227 } 1357 }
1228 } 1358 }
1229 else 1359 else
1230 NEXT (r->timeout); 1360 min_it (next, r->timeout - ev_now ());
1231 }
1232
1233 if (last_sent + send_interval <= NOW)
1234 { 1361 }
1362
1235 if (!send) 1363 if (!send)
1364 {
1365 // generate a new packet, if wise
1366
1367 if (!established)
1236 { 1368 {
1237 // generate a new packet, if wise 1369 if (vpn->dns_sndpq.empty ())
1238
1239 if (!established)
1240 { 1370 {
1241 if (vpn->dns_sndpq.empty ())
1242 {
1243 send = new dns_snd (this); 1371 send = new dns_snd (this);
1244 1372
1245 printf ("new conn %p %d\n", this, c->conf->id);//D
1246 cfg.reset (THISNODE->id); 1373 cfg.reset (THISNODE->id);
1374 set_cfg ();
1247 send->gen_syn_req (); 1375 send->gen_syn_req ();
1248 }
1249 } 1376 }
1250 else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING 1377 }
1378 else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding
1251 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) 1379 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
1380 {
1381 if (last_sent + send_interval <= ev_now ())
1252 { 1382 {
1253 //printf ("sending data request etc.\n"); //D 1383 //printf ("sending data request etc.\n"); //D
1254 if (!snddq.empty ()) 1384 if (!snddq.empty ())
1255 {
1256 poll_interval = send_interval;
1257 NEXT (NOW + send_interval); 1385 min_it (next, send_interval);
1258 }
1259 1386
1260 send = new dns_snd (this); 1387 send = new dns_snd (this);
1261 send->gen_stream_req (sndseq, snddq); 1388 send->gen_stream_req (sndseq, snddq);
1262 send->timeout = NOW + last_latency * 8.; 1389 send->timeout = ev_now () + min_latency * conf.dns_timeout_factor;
1390 //printf ("SEND %x (%f)\n", send->seqno, send->timeout - ev_now (), min_latency, conf.dns_timeout_factor);//D
1263 1391
1264 sndseq = (sndseq + 1) & SEQNO_MASK; 1392 sndseq = (sndseq + 1) & SEQNO_MASK;
1265 } 1393 }
1266 1394 else
1267 if (send) 1395 min_it (next, last_sent + send_interval - ev_now ());
1268 vpn->dns_sndpq.push_back (send);
1269 } 1396 }
1270 1397
1271 if (send) 1398 if (send)
1272 { 1399 vpn->dns_sndpq.push_back (send);
1273 last_sent = NOW; 1400 }
1401
1402 if (send)
1403 {
1404 last_sent = ev_now ();
1274 sendto (vpn->dnsv4_fd, 1405 sendto (vpn->dnsv4_fd,
1275 send->pkt->at (0), send->pkt->len, 0, 1406 send->pkt->at (0), send->pkt->len, 0,
1276 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); 1407 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
1277 }
1278 } 1408 }
1279 else
1280 NEXT (last_sent + send_interval);
1281 1409
1410 min_it (next, last_sent + max (poll_interval, send_interval) - ev_now ());
1411
1282 slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d)", 1412 slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)",
1283 poll_interval, send_interval, next - NOW, 1413 poll_interval, send_interval, next - ev_now (),
1284 vpn->dns_sndpq.size (), snddq.size ()); 1414 vpn->dns_sndpq.size (), snddq.size (),
1285 1415 rcvpq.size ());
1286 // TODO: no idea when this happens, but when next < NOW, we have a problem
1287 if (next < NOW + 0.0001)
1288 next = NOW + 0.1;
1289 1416
1290 w.start (next); 1417 w.start (next);
1291} 1418}
1292 1419
1293#endif 1420#endif

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