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

Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.20 by pcg, Sun Mar 6 21:32:15 2005 UTC vs.
Revision 1.52 by root, Sun Mar 6 21:01:37 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 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 = 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 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 852 else
751 { 853 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 }
756 854
757 rcvpq.push_back (r); 855 rcvpq.push_back (r);
758 856
759 redo: 857 redo:
760 858
761 // find next packet 859 // find next packet
762 for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); ) 860 for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); )
763 if (SEQNO_EQ (rcvseq, (*i)->seqno)) 861 if (SEQNO_EQ (rcvseq, (*i)->seqno))
764 { 862 {
863 //printf ("seqno eq %x %x\n", rcvseq, (*i)->seqno);//D
765 // enter the packet into our input stream 864 // enter the packet into our input stream
766 r = *i; 865 r = *i;
767 866
768 // remove the oldest packet, look forward, as it's oldest first 867 // remove the oldest packet, look forward, as it's oldest first
769 for (vector<dns_rcv *>::iterator j = rcvpq.begin (); j != rcvpq.end (); ++j) 868 for (vector<dns_rcv *>::iterator j = rcvpq.begin (); j != rcvpq.end (); ++j)
770 if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW)) 869 if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW))
771 { 870 {
871 //printf ("seqno RR %x %x\n", (*j)->seqno, rcvseq - MAX_WINDOW);//D
772 delete *j; 872 delete *j;
773 rcvpq.erase (j); 873 rcvpq.erase (j);
774 break; 874 break;
775 } 875 }
776 876
777 rcvseq = (rcvseq + 1) & SEQNO_MASK; 877 rcvseq = (rcvseq + 1) & SEQNO_MASK;
778 878
779 if (!rcvdq.put (r->data, r->datalen)) 879 if (!rcvdq.put (r->data, r->datalen))
780 { 880 {
881 // MUST never overflow, can be caused by data corruption, TODO
781 slog (L_ERR, "DNS: !rcvdq.put (r->data, r->datalen)"); 882 slog (L_CRIT, "DNS: !rcvdq.put (r->data, r->datalen)");
782 abort (); // MUST never overflow, can be caused by data corruption, TODO 883 reset ();
884 return;
783 } 885 }
784 886
785 while (vpn_packet *pkt = rcvdq.get ()) 887 while (vpn_packet *pkt = rcvdq.get ())
786 { 888 {
787 sockinfo si; 889 sockinfo si;
788 si.host = 0x01010101; si.port = htons (c->conf->id); si.prot = PROT_DNSv4; 890 si.host = htonl (c->conf->id); si.port = 0; si.prot = PROT_DNSv4;
789 891
790 vpn->recv_vpn_packet (pkt, si); 892 vpn->recv_vpn_packet (pkt, si);
791
792 delete pkt; 893 delete pkt;
793 } 894 }
794 895
795 // check for further packets 896 // check for further packets
796 goto redo; 897 goto redo;
… …
807 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR); 908 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR);
808 909
809 if (0 == (flags & (FLAG_RESPONSE | FLAG_OP_MASK)) 910 if (0 == (flags & (FLAG_RESPONSE | FLAG_OP_MASK))
810 && pkt.qdcount == htons (1)) 911 && pkt.qdcount == htons (1))
811 { 912 {
812 char qname[MAXSIZE]; 913 char qname [MAXSIZE];
813 int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs); 914 int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
814 915
815 u16 qtype = pkt [offs++] << 8; qtype |= pkt [offs++]; 916 u16 qtype = pkt [offs++] << 8; qtype |= pkt [offs++];
816 u16 qclass = pkt [offs++] << 8; qclass |= pkt [offs++]; 917 u16 qclass = pkt [offs++] << 8; qclass |= pkt [offs++];
817 918
… …
824 925
825 int dlen = strlen (THISNODE->domain); 926 int dlen = strlen (THISNODE->domain);
826 927
827 if (qclass == RR_CLASS_IN 928 if (qclass == RR_CLASS_IN
828 && qlen > dlen + 1 929 && qlen > dlen + 1
829 && !memcmp (qname + qlen - dlen - 1, THISNODE->domain, dlen)) 930 && !memcmp (qname + qlen - (dlen + 1), THISNODE->domain, dlen))
830 { 931 {
831 // now generate reply 932 // now generate reply
832 pkt.ancount = htons (1); // one answer RR 933 pkt.ancount = htons (1); // one answer RR
833 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_OK); 934 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_OK);
834 935
… …
839 { 940 {
840 // correct class, domain: parse 941 // correct class, domain: parse
841 int client, seqno; 942 int client, seqno;
842 decode_header (qname, client, seqno); 943 decode_header (qname, client, seqno);
843 944
844 u8 data[MAXSIZE];
845 int datalen = cdc62.decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE));
846
847 if (0 < client && client <= conns.size ()) 945 if (0 < client && client <= conns.size ())
848 { 946 {
849 connection *c = conns [client - 1]; 947 connection *c = conns [client - 1];
850 dns_connection *dns = c->dns; 948 dns_connection *dns = c->dns;
851 dns_rcv *rcv; 949 dns_rcv *rcv;
852 bool in_seq;
853 950
854 if (dns) 951 if (dns)
855 { 952 {
953 u8 data[MAXSIZE];
954 int datalen = dns->cdc->decode (data, qname + HDRSIZE, qlen - (dlen + 1 + HDRSIZE));
955
856 for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); ) 956 for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); )
857 if (SEQNO_EQ ((*i)->seqno, seqno)) 957 if (SEQNO_EQ ((*i)->seqno, seqno))
858 { 958 {
859 // already seen that request: simply reply with the cached reply 959 // already seen that request: simply reply with the cached reply
860 dns_rcv *r = *i; 960 dns_rcv *r = *i;
… …
868 memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len); 968 memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len);
869 969
870 goto duplicate_request; 970 goto duplicate_request;
871 } 971 }
872 972
873 in_seq = dns->rcvseq == seqno;
874
875 // new packet, queue 973 // new packet, queue
876 rcv = new dns_rcv (seqno, data, datalen); 974 rcv = new dns_rcv (seqno, data, datalen);
877 dns->receive_rep (rcv); 975 dns->receive_rep (rcv);
878 } 976 }
879 977
978 {
880 pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section 979 pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section
881 980
882 int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A; 981 int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A;
883 pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type 982 pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type
884 pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class 983 pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
885 pkt [offs++] = 0; pkt [offs++] = 0; 984 pkt [offs++] = 0; pkt [offs++] = 0;
886 pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL 985 pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL
887 986
888 int rdlen_offs = offs += 2; 987 int rdlen_offs = offs += 2;
889 988
989 if (dns)
990 {
890 int dlen = (dns ? ntohs (dns->cfg.max_size) : MAX_PKT_SIZE) - offs; 991 int dlen = ntohs (dns->cfg.max_size) - offs;
992
891 // bind doesn't compress well, so reduce further by one label length 993 // bind doesn't compress well, so reduce further by one label length
892 dlen -= qlen; 994 dlen -= qlen;
893 995
894 if (dns)
895 {
896 // only put data into in-order sequence packets, if 996 // only put data into in-order sequence packets, if
897 // we receive out-of-order packets we generate empty 997 // we receive out-of-order packets we generate empty
898 // replies 998 // replies
899 while (dlen > 1 && !dns->snddq.empty () && in_seq) 999 //printf ("%d - %d & %x (=%d) < %d\n", seqno, dns->repseq, SEQNO_MASK, (seqno - dns->repseq) & SEQNO_MASK, MAX_WINDOW);//D
1000 if (((seqno - dns->repseq) & SEQNO_MASK) <= MAX_WINDOW)
900 { 1001 {
1002 dns->repseq = seqno;
1003
1004 while (dlen > 1 && !dns->snddq.empty ())
1005 {
901 int txtlen = dlen <= 255 ? dlen - 1 : 255; 1006 int txtlen = dlen <= 255 ? dlen - 1 : 255;
902 1007
903 if (txtlen > dns->snddq.size ()) 1008 if (txtlen > dns->snddq.size ())
904 txtlen = dns->snddq.size (); 1009 txtlen = dns->snddq.size ();
905 1010
906 pkt[offs++] = txtlen; 1011 pkt[offs++] = txtlen;
907 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen); 1012 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
908 offs += txtlen; 1013 offs += txtlen;
909 dns->snddq.remove (txtlen); 1014 dns->snddq.remove (txtlen);
910 1015
911 dlen -= txtlen + 1; 1016 dlen -= txtlen + 1;
1017 }
912 } 1018 }
913 1019
914 // avoid empty TXT rdata 1020 // avoid completely empty TXT rdata
915 if (offs == rdlen_offs) 1021 if (offs == rdlen_offs)
916 pkt[offs++] = 0; 1022 pkt[offs++] = 0;
917 1023
918 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ()); 1024 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
919 } 1025 }
920 else 1026 else
921 { 1027 {
922 // send RST 1028 // send RST
923 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3; 1029 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
924 pkt [offs++] = CMD_IP_RST; 1030 pkt [offs++] = CMD_IP_RST;
925 } 1031 }
926 1032
927 int rdlen = offs - rdlen_offs; 1033 int rdlen = offs - rdlen_offs;
928 1034
929 pkt [rdlen_offs - 2] = rdlen >> 8; 1035 pkt [rdlen_offs - 2] = rdlen >> 8;
930 pkt [rdlen_offs - 1] = rdlen; 1036 pkt [rdlen_offs - 1] = rdlen;
931 1037
932 if (dns) 1038 if (dns)
933 { 1039 {
934 // now update dns_rcv copy 1040 // now update dns_rcv copy
935 rcv->pkt->len = offs; 1041 rcv->pkt->len = offs;
936 memcpy (rcv->pkt->at (0), pkt.at (0), offs); 1042 memcpy (rcv->pkt->at (0), pkt.at (0), offs);
937 } 1043 }
1044 }
938 1045
939 duplicate_request: ; 1046 duplicate_request: ;
940 } 1047 }
941 else 1048 else
942 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR); 1049 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR);
… …
954 pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class 1061 pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
955 pkt [offs++] = 0; pkt [offs++] = 0; 1062 pkt [offs++] = 0; pkt [offs++] = 0;
956 pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL 1063 pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL
957 pkt [offs++] = 0; pkt [offs++] = 4; // rdlength 1064 pkt [offs++] = 0; pkt [offs++] = 4; // rdlength
958 1065
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; 1066 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
962 pkt [offs++] = CMD_IP_REJ; 1067 pkt [offs++] = CMD_IP_REJ;
963 1068
964 if (0 < client && client <= conns.size ()) 1069 if (0 < client && client <= conns.size ())
965 { 1070 {
966 connection *c = conns [client - 1]; 1071 connection *c = conns [client - 1];
967 1072
968 if (cfg.valid ()) 1073 if (cfg.valid ())
969 { 1074 {
970 pkt [offs - 1] = CMD_IP_SYN; 1075 slog (L_INFO, _("DNS: client %d connects (version %d, req_cdc %d)"), client, cfg.version, cfg.req_cdc);
1076
1077 // check for any encoding mismatches - hints at a case problem
1078 char qname2 [MAX_ENC_LEN];
1079 cdc26.encode (qname2, (u8 *)&cfg, sizeof (dns_cfg));
971 1080
972 delete c->dns; 1081 delete c->dns;
1082
1083 pkt [offs - 1] = memcmp (qname, qname2, cdc26.encode_len (sizeof (dns_cfg)))
1084 ? CMD_IP_CSE : CMD_IP_SYN;
1085
973 c->dns = new dns_connection (c); 1086 c->dns = new dns_connection (c);
974 c->dns->cfg = cfg; 1087 c->dns->cfg = cfg;
1088 c->dns->set_cfg ();
975 } 1089 }
976 } 1090 }
977 } 1091 }
978 } 1092 }
979 1093
… …
998 { 1112 {
999 dns_connection *dns = (*i)->dns; 1113 dns_connection *dns = (*i)->dns;
1000 connection *c = dns->c; 1114 connection *c = dns->c;
1001 int seqno = (*i)->seqno; 1115 int seqno = (*i)->seqno;
1002 u8 data[MAXSIZE], *datap = data; 1116 u8 data[MAXSIZE], *datap = data;
1117 //printf ("rcv pkt %x\n", seqno);//D
1003 1118
1004 if ((*i)->retry) 1119 if ((*i)->retry)
1005 { 1120 {
1006 dns->send_interval *= 1.01; 1121 dns->send_interval *= 1.01;
1007 if (dns->send_interval > MAX_SEND_INTERVAL) 1122 if (dns->send_interval > MAX_SEND_INTERVAL)
1008 dns->send_interval = MAX_SEND_INTERVAL; 1123 dns->send_interval = MAX_SEND_INTERVAL;
1009 } 1124 }
1010 else 1125 else
1011 { 1126 {
1012#if 1 1127#if 0
1013 dns->send_interval *= 0.999; 1128 dns->send_interval *= 0.999;
1014#endif 1129#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 1130 // the latency surely puts an upper bound on
1019 // the minimum send interval 1131 // the minimum send interval
1020 double latency = NOW - (*i)->sent; 1132 double latency = ev_now () - (*i)->sent;
1133
1134 if (latency < dns->min_latency)
1021 dns->last_latency = latency; 1135 dns->min_latency = latency;
1022 1136
1023 if (dns->send_interval > latency) 1137 if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor)
1138 dns->send_interval = dns->min_latency * conf.dns_overlap_factor;
1139
1140 if (dns->send_interval < conf.dns_send_interval)
1024 dns->send_interval = latency; 1141 dns->send_interval = conf.dns_send_interval;
1025 } 1142 }
1026 1143
1027 delete *i; 1144 delete *i;
1028 dns_sndpq.erase (i); 1145 dns_sndpq.erase (i);
1029 1146
… …
1047 ttl |= pkt [offs++] << 16; 1164 ttl |= pkt [offs++] << 16;
1048 ttl |= pkt [offs++] << 8; 1165 ttl |= pkt [offs++] << 8;
1049 ttl |= pkt [offs++]; 1166 ttl |= pkt [offs++];
1050 u16 rdlen = pkt [offs++] << 8; rdlen |= pkt [offs++]; 1167 u16 rdlen = pkt [offs++] << 8; rdlen |= pkt [offs++];
1051 1168
1052 if (qtype == RR_TYPE_NULL || qtype == RR_TYPE_TXT) 1169 if (qtype == RR_TYPE_NULL || qtype == RR_TYPE_TXT || qtype == dns->cfg.rrtype)
1053 { 1170 {
1054 if (rdlen <= MAXSIZE - offs) 1171 if (rdlen <= MAXSIZE - offs)
1055 { 1172 {
1056 // decode bytes, finally 1173 // decode bytes, finally
1057 1174
… …
1083 { 1200 {
1084 slog (L_TRACE, _("DNS: got tunnel meta command %02x"), ip [3]); 1201 slog (L_TRACE, _("DNS: got tunnel meta command %02x"), ip [3]);
1085 1202
1086 if (ip [3] == CMD_IP_RST) 1203 if (ip [3] == CMD_IP_RST)
1087 { 1204 {
1088 slog (L_DEBUG, _("DNS: got tunnel RST request")); 1205 slog (L_DEBUG, _("DNS: got tunnel RST request."));
1089 1206
1090 delete dns; c->dns = 0; 1207 dns->reset ();
1091
1092 return; 1208 return;
1093 } 1209 }
1094 else if (ip [3] == CMD_IP_SYN) 1210 else if (ip [3] == CMD_IP_SYN)
1095 { 1211 {
1096 slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us.")); 1212 slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us."));
1097 dns->established = true; 1213 dns->established = true;
1098 } 1214 }
1215 else if (ip [3] == CMD_IP_CSE)
1216 {
1217 if (conf.dns_case_preserving)
1218 {
1219 slog (L_INFO, _("DNS: got tunnel CSE reply, globally downgrading to case-insensitive protocol."));
1220 conf.dns_case_preserving = false;
1221 dns->reset ();
1222 return;
1223 }
1224 else
1225 {
1226 slog (L_DEBUG, _("DNS: got tunnel CSE reply, server likes us."));
1227 dns->established = true;
1228 }
1229 }
1099 else if (ip [3] == CMD_IP_REJ) 1230 else if (ip [3] == CMD_IP_REJ)
1100 { 1231 {
1101 slog (L_DEBUG, _("DNS: got tunnel REJ reply, server does not like us, aborting.")); 1232 slog (L_ERR, _("DNS: got tunnel REJ reply, server does not like us."));
1102 abort (); 1233 dns->tw.start (60.);
1103 } 1234 }
1104 else 1235 else
1236 {
1105 slog (L_INFO, _("DNS: got unknown meta command %02x"), ip [3]); 1237 slog (L_INFO, _("DNS: got unknown meta command %02x"), ip [3]);
1238 dns->tw.start (60.);
1239 }
1106 } 1240 }
1107 else 1241 else
1108 slog (L_INFO, _("DNS: got spurious a record %d.%d.%d.%d"), 1242 slog (L_INFO, _("DNS: got spurious a record %d.%d.%d.%d"),
1109 ip [0], ip [1], ip [2], ip [3]); 1243 ip [0], ip [1], ip [2], ip [3]);
1110 1244
… …
1134 break; 1268 break;
1135 } 1269 }
1136} 1270}
1137 1271
1138void 1272void
1139vpn::dnsv4_ev (io_watcher &w, short revents) 1273vpn::dnsv4_ev (ev::io &w, int revents)
1140{ 1274{
1141 if (revents & EVENT_READ) 1275 if (revents & EV_READ)
1142 { 1276 {
1143 dns_packet *pkt = new dns_packet; 1277 dns_packet *pkt = new dns_packet;
1144 struct sockaddr_in sa; 1278 struct sockaddr_in sa;
1145 socklen_t sa_len = sizeof (sa); 1279 socklen_t sa_len = sizeof (sa);
1146 1280
1147 pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len); 1281 pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len);
1148 1282
1149 if (pkt->len > 0) 1283 if (pkt->len > 0)
1150 { 1284 {
1151 if (THISNODE->dns_port) 1285 if (ntohs (pkt->flags) & FLAG_RESPONSE)
1286 dnsv4_client (*pkt);
1287 else
1152 { 1288 {
1153 dnsv4_server (*pkt); 1289 dnsv4_server (*pkt);
1154 sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len); 1290 sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len);
1155 } 1291 }
1156 else
1157 dnsv4_client (*pkt);
1158 1292
1159 delete pkt; 1293 delete pkt;
1160 } 1294 }
1161 } 1295 }
1162} 1296}
1163 1297
1164bool 1298bool
1165vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) 1299vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
1166{ 1300{
1167 int client = ntohs (si.port); 1301 int client = ntohl (si.host);
1168 1302
1169 assert (0 < client && client <= conns.size ()); 1303 assert (0 < client && client <= conns.size ());
1170 1304
1171 connection *c = conns [client - 1]; 1305 connection *c = conns [client - 1];
1172 1306
1173 if (!c->dns) 1307 if (!c->dns)
1174 c->dns = new dns_connection (c); 1308 c->dns = new dns_connection (c);
1175 1309
1176 if (!c->dns->snddq.put (pkt)) 1310 if (c->dns->snddq.put (pkt))
1177 return false; 1311 {
1312 min_it (c->dns->poll_interval, 0.25);
1313 c->dns->tw ();
1314 }
1178 1315
1179 c->dns->tw.trigger (); 1316 // always return true even if the buffer overflows
1180
1181 return true; 1317 return true;
1182} 1318}
1183 1319
1184void 1320void
1185connection::dnsv4_reset_connection () 1321dns_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{ 1322{
1195 // servers have to be polled 1323 // servers have to be polled
1196 if (THISNODE->dns_port) 1324 if (THISNODE->dns_port)
1197 return; 1325 return;
1198 1326
1199 // check for timeouts and (re)transmit 1327 // check for timeouts and (re)transmit
1200 tstamp next = NOW + poll_interval; 1328 tstamp next = 86400 * 365;
1201 dns_snd *send = 0; 1329 dns_snd *send = 0;
1202 1330
1203 for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin (); 1331 for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin ();
1204 i != vpn->dns_sndpq.end (); 1332 i != vpn->dns_sndpq.end ();
1205 ++i) 1333 ++i)
1206 { 1334 {
1207 dns_snd *r = *i; 1335 dns_snd *r = *i;
1208 1336
1209 if (r->timeout <= NOW) 1337 if (r->timeout <= ev_now ())
1210 { 1338 {
1211 if (!send) 1339 if (!send)
1212 { 1340 {
1213 send = r; 1341 send = r;
1214 1342
1215 r->retry++; 1343 r->retry++;
1216 r->timeout = NOW + (r->retry * last_latency * 8.); 1344 r->timeout = ev_now () + r->retry * min_latency * conf.dns_timeout_factor;
1345 //printf ("RETRY %x (%d, %f)\n", r->seqno, r->retry, r->timeout - ev_now ());//D
1217 1346
1218 // the following code changes the query section a bit, forcing 1347 // the following code changes the query section a bit, forcing
1219 // the forwarder to generate a new request 1348 // the forwarder to generate a new request
1220 if (r->stdhdr) 1349 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); 1350 encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry);
1224 }
1225 } 1351 }
1226 } 1352 }
1227 else 1353 else
1228 NEXT (r->timeout); 1354 min_it (next, r->timeout - ev_now ());
1229 }
1230
1231 if (last_sent + send_interval <= NOW)
1232 { 1355 }
1356
1233 if (!send) 1357 if (!send)
1358 {
1359 // generate a new packet, if wise
1360
1361 if (!established)
1234 { 1362 {
1235 // generate a new packet, if wise 1363 if (vpn->dns_sndpq.empty ())
1236
1237 if (!established)
1238 { 1364 {
1239 if (vpn->dns_sndpq.empty ())
1240 {
1241 send = new dns_snd (this); 1365 send = new dns_snd (this);
1242 1366
1243 printf ("new conn %p %d\n", this, c->conf->id);//D
1244 cfg.reset (THISNODE->id); 1367 cfg.reset (THISNODE->id);
1368 set_cfg ();
1245 send->gen_syn_req (); 1369 send->gen_syn_req ();
1246 }
1247 } 1370 }
1248 else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING 1371 }
1372 else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding
1249 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) 1373 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
1374 {
1375 if (last_sent + send_interval <= ev_now ())
1250 { 1376 {
1251 //printf ("sending data request etc.\n"); //D 1377 //printf ("sending data request etc.\n"); //D
1252 if (!snddq.empty ()) 1378 if (!snddq.empty ())
1253 {
1254 poll_interval = send_interval;
1255 NEXT (NOW + send_interval); 1379 min_it (next, send_interval);
1256 }
1257 1380
1258 send = new dns_snd (this); 1381 send = new dns_snd (this);
1259 send->gen_stream_req (sndseq, snddq); 1382 send->gen_stream_req (sndseq, snddq);
1260 send->timeout = NOW + last_latency * 8.; 1383 send->timeout = ev_now () + min_latency * conf.dns_timeout_factor;
1384 //printf ("SEND %x (%f)\n", send->seqno, send->timeout - ev_now (), min_latency, conf.dns_timeout_factor);//D
1261 1385
1262 sndseq = (sndseq + 1) & SEQNO_MASK; 1386 sndseq = (sndseq + 1) & SEQNO_MASK;
1263 } 1387 }
1264 1388 else
1265 if (send) 1389 min_it (next, last_sent + send_interval - ev_now ());
1266 vpn->dns_sndpq.push_back (send);
1267 } 1390 }
1268 1391
1269 if (send) 1392 if (send)
1270 { 1393 vpn->dns_sndpq.push_back (send);
1271 last_sent = NOW; 1394 }
1395
1396 if (send)
1397 {
1398 last_sent = ev_now ();
1272 sendto (vpn->dnsv4_fd, 1399 sendto (vpn->dnsv4_fd,
1273 send->pkt->at (0), send->pkt->len, 0, 1400 send->pkt->at (0), send->pkt->len, 0,
1274 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); 1401 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
1275 }
1276 } 1402 }
1277 else
1278 NEXT (last_sent + send_interval);
1279 1403
1404 min_it (next, last_sent + max (poll_interval, send_interval) - ev_now ());
1405
1280 slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d)", 1406 slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)",
1281 poll_interval, send_interval, next - NOW, 1407 poll_interval, send_interval, next - ev_now (),
1282 vpn->dns_sndpq.size (), snddq.size ()); 1408 vpn->dns_sndpq.size (), snddq.size (),
1283 1409 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 1410
1288 w.start (next); 1411 w.start (next);
1289} 1412}
1290 1413
1291#endif 1414#endif

Diff Legend

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