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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 1.51 by root, Sun Mar 6 19:40:28 2011 UTC

1/* 1/*
2 vpn_dns.C -- handle the dns tunnel part of the protocol. 2 vpn_dns.C -- handle the dns tunnel part of the protocol.
3 Copyright (C) 2003-2005 Marc Lehmann <gvpe@schmorp.de> 3 Copyright (C) 2003-2011 Marc Lehmann <gvpe@schmorp.de>
4 4
5 This file is part of GVPE. 5 This file is part of GVPE.
6 6
7 GVPE is free software; you can redistribute it and/or modify 7 GVPE is free software; you can redistribute it and/or modify it
8 it under the terms of the GNU General Public License as published by 8 under the terms of the GNU General Public License as published by the
9 the Free Software Foundation; either version 2 of the License, or 9 Free Software Foundation; either version 3 of the License, or (at your
10 (at your option) any later version. 10 option) any later version.
11 11
12 This program is distributed in the hope that it will be useful, 12 This program is distributed in the hope that it will be useful, but
13 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
15 GNU General Public License for more details. 15 Public License for more details.
16 16
17 You should have received a copy of the GNU General Public License 17 You should have received a copy of the GNU General Public License along
18 along with gvpe; if not, write to the Free Software 18 with this program; if not, see <http://www.gnu.org/licenses/>.
19 Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 19
20 Additional permission under GNU GPL version 3 section 7
21
22 If you modify this Program, or any covered work, by linking or
23 combining it with the OpenSSL project's OpenSSL library (or a modified
24 version of that library), containing parts covered by the terms of the
25 OpenSSL or SSLeay licenses, the licensors of this Program grant you
26 additional permission to convey the resulting work. Corresponding
27 Source for a non-source form of such a combination shall include the
28 source code for the parts of OpenSSL used as well as that of the
29 covered work.
20*/ 30*/
31
32// TODO: EDNS0 option to increase dns mtu?
33// TODO: re-write dns packet parsing/creation using a safe mem-buffer
34// to ensure no buffer overflows or similar problems.
21 35
22#include "config.h" 36#include "config.h"
23 37
24#if ENABLE_DNS 38#if ENABLE_DNS
25 39
… …
38#include <unistd.h> 52#include <unistd.h>
39#include <fcntl.h> 53#include <fcntl.h>
40 54
41#include <map> 55#include <map>
42 56
57#include <cstdio> /* bug in libgmp: gmp.h relies on cstdio being included */
43#include <gmp.h> 58#include <gmp.h>
44 59
45#include "netcompat.h" 60#include "netcompat.h"
46 61
47#include "vpn.h" 62#include "vpn.h"
48 63
49#define MIN_POLL_INTERVAL .02 // how often to poll minimally when the server has data 64#define MIN_POLL_INTERVAL 0.1 // 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 2. // 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 240 // 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 ()
516{
517 if (!dns_id) 595 if (!dns_id)
518 dns_id = time (0); 596 dns_id = time (0);
519 597
520 // the simplest lsfr with periodicity 65535 i could find 598 // the simplest lsfr with periodicity 65535 i could find
521 dns_id = (dns_id << 1) 599 dns_id = (dns_id << 1)
… …
536 struct vpn *vpn; 614 struct vpn *vpn;
537 615
538 dns_cfg cfg; 616 dns_cfg cfg;
539 617
540 bool established; 618 bool established;
619 const basecoder *cdc;
541 620
542 tstamp last_received; 621 tstamp last_received;
543 tstamp last_sent; 622 tstamp last_sent;
544 double last_latency; 623 double min_latency;
545 double poll_interval, send_interval; 624 double poll_interval, send_interval;
546 625
547 vector<dns_rcv *> rcvpq; 626 vector<dns_rcv *> rcvpq;
548 627
549 byte_stream rcvdq; int rcvseq; 628 byte_stream rcvdq; int rcvseq; int repseq;
550 byte_stream snddq; int sndseq; 629 byte_stream snddq; int sndseq;
551 630
552 void time_cb (time_watcher &w); time_watcher tw; 631 inline void time_cb (ev::timer &w, int revents); ev::timer tw;
553 void receive_rep (dns_rcv *r); 632 void receive_rep (dns_rcv *r);
633
634 void reset (); // quite like tcp RST
635 void set_cfg (); // to be called after any cfg changes
554 636
555 dns_connection (connection *c); 637 dns_connection (connection *c);
556 ~dns_connection (); 638 ~dns_connection ();
557}; 639};
558 640
… …
576: dns (dns) 658: dns (dns)
577{ 659{
578 timeout = 0; 660 timeout = 0;
579 retry = 0; 661 retry = 0;
580 seqno = 0; 662 seqno = 0;
581 sent = NOW; 663 sent = ev_now ();
582 stdhdr = false; 664 stdhdr = false;
583 665
584 pkt = new dns_packet; 666 pkt = new dns_packet;
585 667
586 pkt->id = next_id (); 668 pkt->id = next_id ();
… …
589dns_snd::~dns_snd () 671dns_snd::~dns_snd ()
590{ 672{
591 delete pkt; 673 delete pkt;
592} 674}
593 675
676static void
594static void append_domain (dns_packet &pkt, int &offs, const char *domain) 677append_domain (dns_packet &pkt, int &offs, const char *domain)
595{ 678{
596 // add tunnel domain 679 // add tunnel domain
597 for (;;) 680 for (;;)
598 { 681 {
599 const char *end = strchr (domain, '.'); 682 const char *end = strchr (domain, '.');
… …
612 695
613 domain = end + 1; 696 domain = end + 1;
614 } 697 }
615} 698}
616 699
700void
617void dns_snd::gen_stream_req (int seqno, byte_stream &stream) 701dns_snd::gen_stream_req (int seqno, byte_stream &stream)
618{ 702{
619 stdhdr = true; 703 stdhdr = true;
620 this->seqno = seqno; 704 this->seqno = seqno;
621 705
622 timeout = NOW + INITIAL_TIMEOUT; 706 timeout = ev_now () + INITIAL_TIMEOUT;
623 707
624 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 708 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
625 pkt->qdcount = htons (1); 709 pkt->qdcount = htons (1);
626 710
627 int offs = 6*2; 711 int offs = 6*2;
… …
630 // so we need to have space for 2*MAX_DOMAIN_SIZE + header + extra 714 // so we need to have space for 2*MAX_DOMAIN_SIZE + header + extra
631 715
632 char enc[256], *encp = enc; 716 char enc[256], *encp = enc;
633 encode_header (enc, THISNODE->id, seqno); 717 encode_header (enc, THISNODE->id, seqno);
634 718
635 int datalen = cdc62.decode_len (dlen - (dlen + MAX_LBL_SIZE - 1) / MAX_LBL_SIZE - HDRSIZE); 719 int datalen = dns->cdc->decode_len (dlen - (dlen + MAX_LBL_SIZE - 1) / MAX_LBL_SIZE - HDRSIZE);
636 720
637 if (datalen > stream.size ()) 721 if (datalen > stream.size ())
638 datalen = stream.size (); 722 datalen = stream.size ();
639 723
640 int enclen = cdc62.encode (enc + HDRSIZE, stream.begin (), datalen) + HDRSIZE; 724 int enclen = dns->cdc->encode (enc + HDRSIZE, stream.begin (), datalen) + HDRSIZE;
641 stream.remove (datalen); 725 stream.remove (datalen);
642 726
643 while (enclen) 727 while (enclen)
644 { 728 {
645 int lbllen = enclen < MAX_LBL_SIZE ? enclen : MAX_LBL_SIZE; 729 int lbllen = enclen < MAX_LBL_SIZE ? enclen : MAX_LBL_SIZE;
… …
660 (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN; 744 (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN;
661 745
662 pkt->len = offs; 746 pkt->len = offs;
663} 747}
664 748
749void
665void dns_snd::gen_syn_req () 750dns_snd::gen_syn_req ()
666{ 751{
667 timeout = NOW + INITIAL_SYN_TIMEOUT; 752 timeout = ev_now () + INITIAL_SYN_TIMEOUT;
668
669 printf ("send syn\n");//D
670 753
671 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 754 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
672 pkt->qdcount = htons (1); 755 pkt->qdcount = htons (1);
673 756
674 int offs = 6 * 2; 757 int offs = 6 * 2;
… …
713///////////////////////////////////////////////////////////////////////////// 796/////////////////////////////////////////////////////////////////////////////
714 797
715dns_connection::dns_connection (connection *c) 798dns_connection::dns_connection (connection *c)
716: c (c) 799: c (c)
717, rcvdq (MAX_BACKLOG * 2) 800, rcvdq (MAX_BACKLOG * 2)
718, snddq (MAX_BACKLOG * 2) 801, snddq (MAX_BACKLOG)
719, tw (this, &dns_connection::time_cb)
720{ 802{
803 tw.set<dns_connection, &dns_connection::time_cb> (this);
804
721 vpn = c->vpn; 805 vpn = c->vpn;
722 806
807 reset ();
808}
809
810dns_connection::~dns_connection ()
811{
812 reset ();
813}
814
815void
816dns_connection::reset ()
817{
818 while (!rcvpq.empty ())
819 {
820 delete rcvpq.back ();
821 rcvpq.pop_back ();
822 }
823
824 for (int i = vpn->dns_sndpq.size (); i--; )
825 if (vpn->dns_sndpq [i]->dns == this)
826 {
827 vpn->dns_sndpq [i] = vpn->dns_sndpq.back ();
828 vpn->dns_sndpq.pop_back ();
829 }
830
723 established = false; 831 established = false;
724 832
725 rcvseq = sndseq = 0; 833 rcvseq = repseq = sndseq = 0;
726 834
727 last_sent = last_received = 0; 835 last_sent = last_received = 0;
728 poll_interval = MIN_POLL_INTERVAL; 836 poll_interval = 0.5; // starting here
729 send_interval = 0.5; // starting rate 837 send_interval = 0.5; // starting rate
730 last_latency = INITIAL_TIMEOUT; 838 min_latency = INITIAL_TIMEOUT;
731} 839}
732 840
733dns_connection::~dns_connection () 841void
842dns_connection::set_cfg ()
734{ 843{
735 for (vector<dns_rcv *>::iterator i = rcvpq.begin (); 844 cdc = cfg.req_cdc == 36 ? &cdc36 : &cdc62;
736 i != rcvpq.end ();
737 ++i)
738 delete *i;
739} 845}
740 846
847void
741void dns_connection::receive_rep (dns_rcv *r) 848dns_connection::receive_rep (dns_rcv *r)
742{ 849{
743 if (r->datalen) 850 if (r->datalen)
744 { 851 {
745 last_received = NOW; 852 last_received = ev_now ();
746 tw.trigger (); 853 tw ();
747 854
748 poll_interval = send_interval; 855 poll_interval = send_interval;
749 } 856 }
750 else 857 else
751 { 858 {
752 poll_interval *= 1.5; 859 poll_interval *= 1.5;
860
753 if (poll_interval > MAX_POLL_INTERVAL) 861 if (poll_interval > MAX_POLL_INTERVAL)
754 poll_interval = MAX_POLL_INTERVAL; 862 poll_interval = MAX_POLL_INTERVAL;
755 } 863 }
756 864
757 rcvpq.push_back (r); 865 rcvpq.push_back (r);
… …
760 868
761 // find next packet 869 // find next packet
762 for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); ) 870 for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); )
763 if (SEQNO_EQ (rcvseq, (*i)->seqno)) 871 if (SEQNO_EQ (rcvseq, (*i)->seqno))
764 { 872 {
873 //printf ("seqno eq %x %x\n", rcvseq, (*i)->seqno);//D
765 // enter the packet into our input stream 874 // enter the packet into our input stream
766 r = *i; 875 r = *i;
767 876
768 // remove the oldest packet, look forward, as it's oldest first 877 // remove the oldest packet, look forward, as it's oldest first
769 for (vector<dns_rcv *>::iterator j = rcvpq.begin (); j != rcvpq.end (); ++j) 878 for (vector<dns_rcv *>::iterator j = rcvpq.begin (); j != rcvpq.end (); ++j)
770 if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW)) 879 if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW))
771 { 880 {
881 //printf ("seqno RR %x %x\n", (*j)->seqno, rcvseq - MAX_WINDOW);//D
772 delete *j; 882 delete *j;
773 rcvpq.erase (j); 883 rcvpq.erase (j);
774 break; 884 break;
775 } 885 }
776 886
777 rcvseq = (rcvseq + 1) & SEQNO_MASK; 887 rcvseq = (rcvseq + 1) & SEQNO_MASK;
778 888
779 if (!rcvdq.put (r->data, r->datalen)) 889 if (!rcvdq.put (r->data, r->datalen))
780 { 890 {
891 // MUST never overflow, can be caused by data corruption, TODO
781 slog (L_ERR, "DNS: !rcvdq.put (r->data, r->datalen)"); 892 slog (L_CRIT, "DNS: !rcvdq.put (r->data, r->datalen)");
782 abort (); // MUST never overflow, can be caused by data corruption, TODO 893 reset ();
894 return;
783 } 895 }
784 896
785 while (vpn_packet *pkt = rcvdq.get ()) 897 while (vpn_packet *pkt = rcvdq.get ())
786 { 898 {
787 sockinfo si; 899 sockinfo si;
788 si.host = 0x01010101; si.port = htons (c->conf->id); si.prot = PROT_DNSv4; 900 si.host = htonl (c->conf->id); si.port = 0; si.prot = PROT_DNSv4;
789 901
790 vpn->recv_vpn_packet (pkt, si); 902 vpn->recv_vpn_packet (pkt, si);
791
792 delete pkt; 903 delete pkt;
793 } 904 }
794 905
795 // check for further packets 906 // check for further packets
796 goto redo; 907 goto redo;
… …
807 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR); 918 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR);
808 919
809 if (0 == (flags & (FLAG_RESPONSE | FLAG_OP_MASK)) 920 if (0 == (flags & (FLAG_RESPONSE | FLAG_OP_MASK))
810 && pkt.qdcount == htons (1)) 921 && pkt.qdcount == htons (1))
811 { 922 {
812 char qname[MAXSIZE]; 923 char qname [MAXSIZE];
813 int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs); 924 int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
814 925
815 u16 qtype = pkt [offs++] << 8; qtype |= pkt [offs++]; 926 u16 qtype = pkt [offs++] << 8; qtype |= pkt [offs++];
816 u16 qclass = pkt [offs++] << 8; qclass |= pkt [offs++]; 927 u16 qclass = pkt [offs++] << 8; qclass |= pkt [offs++];
817 928
… …
824 935
825 int dlen = strlen (THISNODE->domain); 936 int dlen = strlen (THISNODE->domain);
826 937
827 if (qclass == RR_CLASS_IN 938 if (qclass == RR_CLASS_IN
828 && qlen > dlen + 1 939 && qlen > dlen + 1
829 && !memcmp (qname + qlen - dlen - 1, THISNODE->domain, dlen)) 940 && !memcmp (qname + qlen - (dlen + 1), THISNODE->domain, dlen))
830 { 941 {
831 // now generate reply 942 // now generate reply
832 pkt.ancount = htons (1); // one answer RR 943 pkt.ancount = htons (1); // one answer RR
833 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_OK); 944 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_OK);
834 945
… …
839 { 950 {
840 // correct class, domain: parse 951 // correct class, domain: parse
841 int client, seqno; 952 int client, seqno;
842 decode_header (qname, client, seqno); 953 decode_header (qname, client, seqno);
843 954
844 u8 data[MAXSIZE];
845 int datalen = cdc62.decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE));
846
847 if (0 < client && client <= conns.size ()) 955 if (0 < client && client <= conns.size ())
848 { 956 {
849 connection *c = conns [client - 1]; 957 connection *c = conns [client - 1];
850 dns_connection *dns = c->dns; 958 dns_connection *dns = c->dns;
851 dns_rcv *rcv; 959 dns_rcv *rcv;
852 bool in_seq;
853 960
854 if (dns) 961 if (dns)
855 { 962 {
963 u8 data[MAXSIZE];
964 int datalen = dns->cdc->decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE));
965
856 for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); ) 966 for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); )
857 if (SEQNO_EQ ((*i)->seqno, seqno)) 967 if (SEQNO_EQ ((*i)->seqno, seqno))
858 { 968 {
859 // already seen that request: simply reply with the cached reply 969 // already seen that request: simply reply with the cached reply
860 dns_rcv *r = *i; 970 dns_rcv *r = *i;
… …
868 memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len); 978 memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len);
869 979
870 goto duplicate_request; 980 goto duplicate_request;
871 } 981 }
872 982
873 in_seq = dns->rcvseq == seqno;
874
875 // new packet, queue 983 // new packet, queue
876 rcv = new dns_rcv (seqno, data, datalen); 984 rcv = new dns_rcv (seqno, data, datalen);
877 dns->receive_rep (rcv); 985 dns->receive_rep (rcv);
878 } 986 }
879 987
… …
886 pkt [offs++] = 0; pkt [offs++] = 0; 994 pkt [offs++] = 0; pkt [offs++] = 0;
887 pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL 995 pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL
888 996
889 int rdlen_offs = offs += 2; 997 int rdlen_offs = offs += 2;
890 998
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) 999 if (dns)
896 { 1000 {
1001 int dlen = ntohs (dns->cfg.max_size) - offs;
1002
1003 // bind doesn't compress well, so reduce further by one label length
1004 dlen -= qlen;
1005
897 // only put data into in-order sequence packets, if 1006 // only put data into in-order sequence packets, if
898 // we receive out-of-order packets we generate empty 1007 // we receive out-of-order packets we generate empty
899 // replies 1008 // replies
900 while (dlen > 1 && !dns->snddq.empty () && in_seq) 1009 //printf ("%d - %d & %x (=%d) < %d\n", seqno, dns->repseq, SEQNO_MASK, (seqno - dns->repseq) & SEQNO_MASK, MAX_WINDOW);//D
1010 if (((seqno - dns->repseq) & SEQNO_MASK) <= MAX_WINDOW)
901 { 1011 {
1012 dns->repseq = seqno;
1013
1014 while (dlen > 1 && !dns->snddq.empty ())
1015 {
902 int txtlen = dlen <= 255 ? dlen - 1 : 255; 1016 int txtlen = dlen <= 255 ? dlen - 1 : 255;
903 1017
904 if (txtlen > dns->snddq.size ()) 1018 if (txtlen > dns->snddq.size ())
905 txtlen = dns->snddq.size (); 1019 txtlen = dns->snddq.size ();
906 1020
907 pkt[offs++] = txtlen; 1021 pkt[offs++] = txtlen;
908 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen); 1022 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
909 offs += txtlen; 1023 offs += txtlen;
910 dns->snddq.remove (txtlen); 1024 dns->snddq.remove (txtlen);
911 1025
912 dlen -= txtlen + 1; 1026 dlen -= txtlen + 1;
1027 }
913 } 1028 }
914 1029
915 // avoid empty TXT rdata 1030 // avoid completely empty TXT rdata
916 if (offs == rdlen_offs) 1031 if (offs == rdlen_offs)
917 pkt[offs++] = 0; 1032 pkt[offs++] = 0;
918 1033
919 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ()); 1034 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
920 } 1035 }
… …
956 pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class 1071 pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
957 pkt [offs++] = 0; pkt [offs++] = 0; 1072 pkt [offs++] = 0; pkt [offs++] = 0;
958 pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL 1073 pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL
959 pkt [offs++] = 0; pkt [offs++] = 4; // rdlength 1074 pkt [offs++] = 0; pkt [offs++] = 4; // rdlength
960 1075
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; 1076 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
964 pkt [offs++] = CMD_IP_REJ; 1077 pkt [offs++] = CMD_IP_REJ;
965 1078
966 if (0 < client && client <= conns.size ()) 1079 if (0 < client && client <= conns.size ())
967 { 1080 {
968 connection *c = conns [client - 1]; 1081 connection *c = conns [client - 1];
969 1082
970 if (cfg.valid ()) 1083 if (cfg.valid ())
971 { 1084 {
972 pkt [offs - 1] = CMD_IP_SYN; 1085 slog (L_INFO, _("DNS: client %d connects (version %d, req_cdc %d)"), client, cfg.version, cfg.req_cdc);
1086
1087 // check for any encoding mismatches - hints at a case problem
1088 char qname2 [MAX_ENC_LEN];
1089 cdc26.encode (qname2, (u8 *)&cfg, sizeof (dns_cfg));
973 1090
974 delete c->dns; 1091 delete c->dns;
1092
1093 pkt [offs - 1] = memcmp (qname, qname2, cdc26.encode_len (sizeof (dns_cfg)))
1094 ? CMD_IP_CSE : CMD_IP_SYN;
1095
975 c->dns = new dns_connection (c); 1096 c->dns = new dns_connection (c);
976 c->dns->cfg = cfg; 1097 c->dns->cfg = cfg;
1098 c->dns->set_cfg ();
977 } 1099 }
978 } 1100 }
979 } 1101 }
980 } 1102 }
981 1103
… …
1000 { 1122 {
1001 dns_connection *dns = (*i)->dns; 1123 dns_connection *dns = (*i)->dns;
1002 connection *c = dns->c; 1124 connection *c = dns->c;
1003 int seqno = (*i)->seqno; 1125 int seqno = (*i)->seqno;
1004 u8 data[MAXSIZE], *datap = data; 1126 u8 data[MAXSIZE], *datap = data;
1127 //printf ("rcv pkt %x\n", seqno);//D
1128 bool back_off = (*i)->retry;
1005 1129
1006 if ((*i)->retry) 1130 if (back_off)
1007 { 1131 {
1008 dns->send_interval *= 1.01; 1132 dns->send_interval *= 1.01;
1009 if (dns->send_interval > MAX_SEND_INTERVAL) 1133 if (dns->send_interval > MAX_SEND_INTERVAL)
1010 dns->send_interval = MAX_SEND_INTERVAL; 1134 dns->send_interval = MAX_SEND_INTERVAL;
1011 } 1135 }
1012 else 1136 else
1013 { 1137 {
1014#if 1 1138#if 0
1015 dns->send_interval *= 0.999; 1139 dns->send_interval *= 0.999;
1016#endif 1140#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 1141 // the latency surely puts an upper bound on
1021 // the minimum send interval 1142 // the minimum send interval
1022 double latency = NOW - (*i)->sent; 1143 double latency = ev_now () - (*i)->sent;
1144
1145 if (latency < dns->min_latency)
1023 dns->last_latency = latency; 1146 dns->min_latency = latency;
1024 1147
1025 if (dns->send_interval > latency) 1148 if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor)
1149 dns->send_interval = dns->min_latency * conf.dns_overlap_factor;
1150
1151 if (dns->send_interval < conf.dns_send_interval)
1026 dns->send_interval = latency; 1152 dns->send_interval = conf.dns_send_interval;
1027 } 1153 }
1028 1154
1029 delete *i; 1155 delete *i;
1030 dns_sndpq.erase (i); 1156 dns_sndpq.erase (i);
1031 1157
… …
1049 ttl |= pkt [offs++] << 16; 1175 ttl |= pkt [offs++] << 16;
1050 ttl |= pkt [offs++] << 8; 1176 ttl |= pkt [offs++] << 8;
1051 ttl |= pkt [offs++]; 1177 ttl |= pkt [offs++];
1052 u16 rdlen = pkt [offs++] << 8; rdlen |= pkt [offs++]; 1178 u16 rdlen = pkt [offs++] << 8; rdlen |= pkt [offs++];
1053 1179
1054 if (qtype == RR_TYPE_NULL || qtype == RR_TYPE_TXT) 1180 if (qtype == RR_TYPE_NULL || qtype == RR_TYPE_TXT || qtype == dns->cfg.rrtype)
1055 { 1181 {
1056 if (rdlen <= MAXSIZE - offs) 1182 if (rdlen <= MAXSIZE - offs)
1057 { 1183 {
1058 // decode bytes, finally 1184 // decode bytes, finally
1059 1185
… …
1085 { 1211 {
1086 slog (L_TRACE, _("DNS: got tunnel meta command %02x"), ip [3]); 1212 slog (L_TRACE, _("DNS: got tunnel meta command %02x"), ip [3]);
1087 1213
1088 if (ip [3] == CMD_IP_RST) 1214 if (ip [3] == CMD_IP_RST)
1089 { 1215 {
1090 slog (L_DEBUG, _("DNS: got tunnel RST request")); 1216 slog (L_DEBUG, _("DNS: got tunnel RST request."));
1091 1217
1092 delete dns; c->dns = 0; 1218 dns->reset ();
1093
1094 return; 1219 return;
1095 } 1220 }
1096 else if (ip [3] == CMD_IP_SYN) 1221 else if (ip [3] == CMD_IP_SYN)
1097 { 1222 {
1098 slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us.")); 1223 slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us."));
1099 dns->established = true; 1224 dns->established = true;
1100 } 1225 }
1226 else if (ip [3] == CMD_IP_CSE)
1227 {
1228 if (conf.dns_case_preserving)
1229 {
1230 slog (L_INFO, _("DNS: got tunnel CSE reply, globally downgrading to case-insensitive protocol."));
1231 conf.dns_case_preserving = false;
1232 dns->reset ();
1233 return;
1234 }
1235 else
1236 {
1237 slog (L_DEBUG, _("DNS: got tunnel CSE reply, server likes us."));
1238 dns->established = true;
1239 }
1240 }
1101 else if (ip [3] == CMD_IP_REJ) 1241 else if (ip [3] == CMD_IP_REJ)
1102 { 1242 {
1103 slog (L_DEBUG, _("DNS: got tunnel REJ reply, server does not like us, aborting.")); 1243 slog (L_ERR, _("DNS: got tunnel REJ reply, server does not like us."));
1104 abort (); 1244 dns->tw.start (60.);
1105 } 1245 }
1106 else 1246 else
1247 {
1107 slog (L_INFO, _("DNS: got unknown meta command %02x"), ip [3]); 1248 slog (L_INFO, _("DNS: got unknown meta command %02x"), ip [3]);
1249 dns->tw.start (60.);
1250 }
1108 } 1251 }
1109 else 1252 else
1110 slog (L_INFO, _("DNS: got spurious a record %d.%d.%d.%d"), 1253 slog (L_INFO, _("DNS: got spurious a record %d.%d.%d.%d"),
1111 ip [0], ip [1], ip [2], ip [3]); 1254 ip [0], ip [1], ip [2], ip [3]);
1112 1255
… …
1130 } 1273 }
1131 1274
1132 // todo: pkt now used 1275 // todo: pkt now used
1133 if (datap) 1276 if (datap)
1134 dns->receive_rep (new dns_rcv (seqno, data, datap - data)); 1277 dns->receive_rep (new dns_rcv (seqno, data, datap - data));
1278 else if (dns_sndpq.empty ()) // no data received, and nothing to send - idle
1279 {
1280 dns->send_interval *= 1.1;
1281
1282 if (dns->send_interval < MIN_POLL_INTERVAL)
1283 dns->send_interval = MIN_POLL_INTERVAL;
1284
1285 if (dns->send_interval > MAX_POLL_INTERVAL && !back_off)
1286 dns->send_interval = MAX_POLL_INTERVAL;
1287 }
1135 1288
1136 break; 1289 break;
1137 } 1290 }
1138} 1291}
1139 1292
1140void 1293void
1141vpn::dnsv4_ev (io_watcher &w, short revents) 1294vpn::dnsv4_ev (ev::io &w, int revents)
1142{ 1295{
1143 if (revents & EVENT_READ) 1296 if (revents & EV_READ)
1144 { 1297 {
1145 dns_packet *pkt = new dns_packet; 1298 dns_packet *pkt = new dns_packet;
1146 struct sockaddr_in sa; 1299 struct sockaddr_in sa;
1147 socklen_t sa_len = sizeof (sa); 1300 socklen_t sa_len = sizeof (sa);
1148 1301
1149 pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len); 1302 pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len);
1150 1303
1151 if (pkt->len > 0) 1304 if (pkt->len > 0)
1152 { 1305 {
1153 if (THISNODE->dns_port) 1306 if (ntohs (pkt->flags) & FLAG_RESPONSE)
1307 dnsv4_client (*pkt);
1308 else
1154 { 1309 {
1155 dnsv4_server (*pkt); 1310 dnsv4_server (*pkt);
1156 sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len); 1311 sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len);
1157 } 1312 }
1158 else
1159 dnsv4_client (*pkt);
1160 1313
1161 delete pkt; 1314 delete pkt;
1162 } 1315 }
1163 } 1316 }
1164} 1317}
1165 1318
1166bool 1319bool
1167vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) 1320vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
1168{ 1321{
1169 int client = ntohs (si.port); 1322 int client = ntohl (si.host);
1170 1323
1171 assert (0 < client && client <= conns.size ()); 1324 assert (0 < client && client <= conns.size ());
1172 1325
1173 connection *c = conns [client - 1]; 1326 connection *c = conns [client - 1];
1174 1327
1175 if (!c->dns) 1328 if (!c->dns)
1176 c->dns = new dns_connection (c); 1329 c->dns = new dns_connection (c);
1177 1330
1178 if (!c->dns->snddq.put (pkt)) 1331 if (c->dns->snddq.put (pkt))
1179 return false;
1180
1181 c->dns->tw.trigger (); 1332 c->dns->tw ();
1182 1333
1334 // always return true even if the buffer overflows
1183 return true; 1335 return true;
1184} 1336}
1185 1337
1338#define NEXT(w) do { if (next > (w)) next = w; } while (0)
1339
1186void 1340void
1187connection::dnsv4_reset_connection () 1341dns_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{ 1342{
1197 // servers have to be polled 1343 // servers have to be polled
1198 if (THISNODE->dns_port) 1344 if (THISNODE->dns_port)
1199 return; 1345 return;
1200 1346
1201 // check for timeouts and (re)transmit 1347 // check for timeouts and (re)transmit
1202 tstamp next = NOW + poll_interval; 1348 tstamp next = ev::now () + poll_interval;
1203 dns_snd *send = 0; 1349 dns_snd *send = 0;
1204 1350
1205 for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin (); 1351 for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin ();
1206 i != vpn->dns_sndpq.end (); 1352 i != vpn->dns_sndpq.end ();
1207 ++i) 1353 ++i)
1208 { 1354 {
1209 dns_snd *r = *i; 1355 dns_snd *r = *i;
1210 1356
1211 if (r->timeout <= NOW) 1357 if (r->timeout <= ev_now ())
1212 { 1358 {
1213 if (!send) 1359 if (!send)
1214 { 1360 {
1215 send = r; 1361 send = r;
1216 1362
1217 r->retry++; 1363 r->retry++;
1218 r->timeout = NOW + (r->retry * last_latency * 8.); 1364 r->timeout = ev_now () + (r->retry * min_latency * conf.dns_timeout_factor);
1365 //printf ("RETRY %x (%d, %f)\n", r->seqno, r->retry, r->timeout - ev_now ());//D
1219 1366
1220 // the following code changes the query section a bit, forcing 1367 // the following code changes the query section a bit, forcing
1221 // the forwarder to generate a new request 1368 // the forwarder to generate a new request
1222 if (r->stdhdr) 1369 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); 1370 encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry);
1226 }
1227 } 1371 }
1228 } 1372 }
1229 else 1373 else
1230 NEXT (r->timeout); 1374 NEXT (r->timeout);
1231 } 1375 }
1232 1376
1233 if (last_sent + send_interval <= NOW)
1234 {
1235 if (!send) 1377 if (!send)
1378 {
1379 // generate a new packet, if wise
1380
1381 if (!established)
1236 { 1382 {
1237 // generate a new packet, if wise 1383 if (vpn->dns_sndpq.empty ())
1238
1239 if (!established)
1240 { 1384 {
1241 if (vpn->dns_sndpq.empty ())
1242 {
1243 send = new dns_snd (this); 1385 send = new dns_snd (this);
1244 1386
1245 printf ("new conn %p %d\n", this, c->conf->id);//D
1246 cfg.reset (THISNODE->id); 1387 cfg.reset (THISNODE->id);
1388 set_cfg ();
1247 send->gen_syn_req (); 1389 send->gen_syn_req ();
1248 }
1249 } 1390 }
1250 else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING 1391 }
1392 else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding
1251 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) 1393 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
1394 {
1395 if (last_sent + send_interval <= ev_now ())
1252 { 1396 {
1253 //printf ("sending data request etc.\n"); //D 1397 //printf ("sending data request etc.\n"); //D
1254 if (!snddq.empty ()) 1398 if (!snddq.empty () || last_received + 1. > ev_now ())
1255 { 1399 {
1256 poll_interval = send_interval; 1400 poll_interval = send_interval;
1257 NEXT (NOW + send_interval); 1401 NEXT (ev_now () + send_interval);
1258 } 1402 }
1259 1403
1260 send = new dns_snd (this); 1404 send = new dns_snd (this);
1261 send->gen_stream_req (sndseq, snddq); 1405 send->gen_stream_req (sndseq, snddq);
1262 send->timeout = NOW + last_latency * 8.; 1406 send->timeout = ev_now () + min_latency * conf.dns_timeout_factor;
1407 //printf ("SEND %x (%f)\n", send->seqno, send->timeout - ev_now (), min_latency, conf.dns_timeout_factor);//D
1263 1408
1264 sndseq = (sndseq + 1) & SEQNO_MASK; 1409 sndseq = (sndseq + 1) & SEQNO_MASK;
1265 } 1410 }
1266 1411 else
1267 if (send) 1412 NEXT (last_sent + send_interval);
1268 vpn->dns_sndpq.push_back (send);
1269 } 1413 }
1270 1414
1271 if (send) 1415 if (send)
1272 { 1416 vpn->dns_sndpq.push_back (send);
1273 last_sent = NOW; 1417 }
1418
1419 if (send)
1420 {
1421 last_sent = ev_now ();
1274 sendto (vpn->dnsv4_fd, 1422 sendto (vpn->dnsv4_fd,
1275 send->pkt->at (0), send->pkt->len, 0, 1423 send->pkt->at (0), send->pkt->len, 0,
1276 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); 1424 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
1277 }
1278 } 1425 }
1279 else
1280 NEXT (last_sent + send_interval);
1281 1426
1282 slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d)", 1427 slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)",
1283 poll_interval, send_interval, next - NOW, 1428 poll_interval, send_interval, next - ev_now (),
1284 vpn->dns_sndpq.size (), snddq.size ()); 1429 vpn->dns_sndpq.size (), snddq.size (),
1430 rcvpq.size ());
1285 1431
1286 // TODO: no idea when this happens, but when next < NOW, we have a problem 1432 // TODO: no idea when this happens, but when next < ev_now (), we have a problem
1433 // doesn't seem to happen anymore
1287 if (next < NOW + 0.0001) 1434 if (next < ev_now () + 0.001)
1288 next = NOW + 0.1; 1435 next = ev_now () + 0.1;
1289 1436
1290 w.start (next); 1437 w.start (next - ev_now ());
1291} 1438}
1292 1439
1293#endif 1440#endif
1294 1441

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