| 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) 2003-2008 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 | |
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20 | Additional permission under GNU GPL version 3 section 7 |
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21 | |
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22 | If you modify this Program, or any covered work, by linking or |
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23 | combining it with the OpenSSL project's OpenSSL library (or a modified |
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24 | version of that library), containing parts covered by the terms of the |
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25 | OpenSSL or SSLeay licenses, the licensors of this Program grant you |
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26 | additional permission to convey the resulting work. Corresponding |
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27 | Source for a non-source form of such a combination shall include the |
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28 | source code for the parts of OpenSSL used as well as that of the |
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29 | covered work. |
| 20 | */ |
30 | */ |
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31 | |
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32 | // TODO: EDNS0 option to increase dns mtu? |
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33 | // TODO: re-write dns packet parsing/creation using a safe mem-buffer |
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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 MAX_POLL_INTERVAL 5. // how often to poll minimally when the server has no data |
64 | #define MAX_POLL_INTERVAL 5. // how often to poll minimally when the server has no data |
| 50 | #define ACTIVITY_INTERVAL 5. |
65 | #define ACTIVITY_INTERVAL 5. |
| 51 | |
66 | |
| 52 | #define INITIAL_TIMEOUT 0.1 // retry timeouts |
67 | #define INITIAL_TIMEOUT 0.1 // retry timeouts |
| 53 | #define INITIAL_SYN_TIMEOUT 10. // retry timeout for initial syn |
68 | #define INITIAL_SYN_TIMEOUT 2. // retry timeout for initial syn |
| 54 | |
69 | |
| 55 | #define MIN_SEND_INTERVAL 0.001 // wait at least this time between sending requests |
|
|
| 56 | #define MAX_SEND_INTERVAL 2. // optimistic? |
70 | #define MAX_SEND_INTERVAL 2. // optimistic? |
| 57 | |
71 | |
| 58 | #define LATENCY_FACTOR 0.5 // RTT * LATENCY_FACTOR == sending rate |
|
|
| 59 | #define MAX_OUTSTANDING 2 // 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 240 // 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 |
| … | |
… | |
| 155 | enc_len [len] = n; |
168 | enc_len [len] = n; |
| 156 | dec_len [n] = len; |
169 | dec_len [n] = len; |
| 157 | } |
170 | } |
| 158 | } |
171 | } |
| 159 | |
172 | |
|
|
173 | unsigned int |
| 160 | unsigned int basecoder::encode_len (unsigned int len) |
174 | basecoder::encode_len (unsigned int len) |
| 161 | { |
175 | { |
| 162 | return enc_len [len]; |
176 | return enc_len [len]; |
| 163 | } |
177 | } |
| 164 | |
178 | |
|
|
179 | unsigned int |
| 165 | unsigned int basecoder::decode_len (unsigned int len) |
180 | basecoder::decode_len (unsigned int len) |
| 166 | { |
181 | { |
| 167 | while (len && !dec_len [len]) |
182 | while (len && !dec_len [len]) |
| 168 | --len; |
183 | --len; |
| 169 | |
184 | |
| 170 | return dec_len [len]; |
185 | return dec_len [len]; |
| 171 | } |
186 | } |
| 172 | |
187 | |
|
|
188 | unsigned int |
| 173 | unsigned int basecoder::encode (char *dst, u8 *src, unsigned int len) |
189 | basecoder::encode (char *dst, u8 *src, unsigned int len) |
| 174 | { |
190 | { |
| 175 | if (!len || len > MAX_DEC_LEN) |
191 | if (!len || len > MAX_DEC_LEN) |
| 176 | return 0; |
192 | return 0; |
| 177 | |
193 | |
| 178 | int elen = encode_len (len); |
194 | int elen = encode_len (len); |
| … | |
… | |
| 197 | *dst++ = cmap.encode [dst_ [i]]; |
213 | *dst++ = cmap.encode [dst_ [i]]; |
| 198 | |
214 | |
| 199 | return elen; |
215 | return elen; |
| 200 | } |
216 | } |
| 201 | |
217 | |
|
|
218 | unsigned int |
| 202 | unsigned int basecoder::decode (u8 *dst, char *src, unsigned int len) |
219 | basecoder::decode (u8 *dst, char *src, unsigned int len) |
| 203 | { |
220 | { |
| 204 | if (!len || len > MAX_ENC_LEN) |
221 | if (!len || len > MAX_ENC_LEN) |
| 205 | return 0; |
222 | return 0; |
| 206 | |
223 | |
| 207 | u8 src_ [MAX_ENC_LEN]; |
224 | u8 src_ [MAX_ENC_LEN]; |
| … | |
… | |
| 266 | |
283 | |
| 267 | ///////////////////////////////////////////////////////////////////////////// |
284 | ///////////////////////////////////////////////////////////////////////////// |
| 268 | |
285 | |
| 269 | #define HDRSIZE 6 |
286 | #define HDRSIZE 6 |
| 270 | |
287 | |
|
|
288 | inline void |
| 271 | inline void encode_header (char *data, int clientid, int seqno, int retry = 0) |
289 | encode_header (char *data, int clientid, int seqno, int retry = 0) |
| 272 | { |
290 | { |
| 273 | seqno &= SEQNO_MASK; |
291 | seqno &= SEQNO_MASK; |
| 274 | |
292 | |
| 275 | u8 hdr[3] = { |
293 | u8 hdr[3] = { |
| 276 | clientid, |
294 | clientid, |
| … | |
… | |
| 281 | assert (clientid < 256); |
299 | assert (clientid < 256); |
| 282 | |
300 | |
| 283 | cdc26.encode (data, hdr, 3); |
301 | cdc26.encode (data, hdr, 3); |
| 284 | } |
302 | } |
| 285 | |
303 | |
|
|
304 | inline void |
| 286 | inline void decode_header (char *data, int &clientid, int &seqno) |
305 | decode_header (char *data, int &clientid, int &seqno) |
| 287 | { |
306 | { |
| 288 | u8 hdr[3]; |
307 | u8 hdr[3]; |
| 289 | |
308 | |
| 290 | cdc26.decode (hdr, data, HDRSIZE); |
309 | cdc26.decode (hdr, data, HDRSIZE); |
| 291 | |
310 | |
| … | |
… | |
| 324 | byte_stream::~byte_stream () |
343 | byte_stream::~byte_stream () |
| 325 | { |
344 | { |
| 326 | delete data; |
345 | delete data; |
| 327 | } |
346 | } |
| 328 | |
347 | |
|
|
348 | void |
| 329 | void byte_stream::remove (int count) |
349 | byte_stream::remove (int count) |
| 330 | { |
350 | { |
| 331 | if (count > fill) |
351 | if (count > fill) |
| 332 | assert (count <= fill); |
352 | assert (count <= fill); |
| 333 | |
353 | |
| 334 | memmove (data, data + count, fill -= count); |
354 | memmove (data, data + count, fill -= count); |
| 335 | } |
355 | } |
| 336 | |
356 | |
|
|
357 | bool |
| 337 | bool byte_stream::put (u8 *data, unsigned int datalen) |
358 | byte_stream::put (u8 *data, unsigned int datalen) |
| 338 | { |
359 | { |
| 339 | if (maxsize - fill < datalen) |
360 | if (maxsize - fill < datalen) |
| 340 | return false; |
361 | return false; |
| 341 | |
362 | |
| 342 | memcpy (this->data + fill, data, datalen); fill += datalen; |
363 | memcpy (this->data + fill, data, datalen); fill += datalen; |
| 343 | |
364 | |
| 344 | return true; |
365 | return true; |
| 345 | } |
366 | } |
| 346 | |
367 | |
|
|
368 | bool |
| 347 | bool byte_stream::put (vpn_packet *pkt) |
369 | byte_stream::put (vpn_packet *pkt) |
| 348 | { |
370 | { |
| 349 | if (maxsize - fill < pkt->len + 2) |
371 | if (maxsize - fill < pkt->len + 2) |
| 350 | return false; |
372 | return false; |
| 351 | |
373 | |
| 352 | data [fill++] = pkt->len >> 8; |
374 | data [fill++] = pkt->len >> 8; |
| … | |
… | |
| 434 | bool valid (); |
456 | bool valid (); |
| 435 | }; |
457 | }; |
| 436 | |
458 | |
| 437 | int dns_cfg::next_uid; |
459 | int dns_cfg::next_uid; |
| 438 | |
460 | |
|
|
461 | void |
| 439 | void dns_cfg::reset (int clientid) |
462 | dns_cfg::reset (int clientid) |
| 440 | { |
463 | { |
| 441 | id1 = 'G'; |
464 | id1 = 'G'; |
| 442 | id2 = 'V'; |
465 | id2 = 'V'; |
| 443 | id3 = 'P'; |
466 | id3 = 'P'; |
| 444 | id4 = 'E'; |
467 | id4 = 'E'; |
| … | |
… | |
| 458 | |
481 | |
| 459 | r3 = r4 = 0; |
482 | r3 = r4 = 0; |
| 460 | r4 = r5 = r6 = r7 = 0; |
483 | r4 = r5 = r6 = r7 = 0; |
| 461 | } |
484 | } |
| 462 | |
485 | |
|
|
486 | bool |
| 463 | bool dns_cfg::valid () |
487 | dns_cfg::valid () |
| 464 | { |
488 | { |
|
|
489 | // although the protocol itself allows for some configurability, |
|
|
490 | // only the following encoding/decoding settings are implemented. |
| 465 | return id1 == 'G' |
491 | return id1 == 'G' |
| 466 | && id2 == 'V' |
492 | && id2 == 'V' |
| 467 | && id3 == 'P' |
493 | && id3 == 'P' |
| 468 | && id4 == 'E' |
494 | && id4 == 'E' |
| 469 | && seq_cdc == 26 |
495 | && seq_cdc == 26 |
| … | |
… | |
| 481 | u8 data [MAXSIZE - 6 * 2]; |
507 | u8 data [MAXSIZE - 6 * 2]; |
| 482 | |
508 | |
| 483 | int decode_label (char *data, int size, int &offs); |
509 | int decode_label (char *data, int size, int &offs); |
| 484 | }; |
510 | }; |
| 485 | |
511 | |
|
|
512 | int |
| 486 | int dns_packet::decode_label (char *data, int size, int &offs) |
513 | dns_packet::decode_label (char *data, int size, int &offs) |
| 487 | { |
514 | { |
| 488 | char *orig = data; |
515 | char *orig = data; |
| 489 | |
516 | |
| 490 | memset (data, 0, size); |
517 | memset (data, 0, size); |
| 491 | |
518 | |
| … | |
… | |
| 517 | return data - orig; |
544 | return data - orig; |
| 518 | } |
545 | } |
| 519 | |
546 | |
| 520 | ///////////////////////////////////////////////////////////////////////////// |
547 | ///////////////////////////////////////////////////////////////////////////// |
| 521 | |
548 | |
|
|
549 | static |
|
|
550 | u16 next_id () |
|
|
551 | { |
| 522 | static u16 dns_id = 0; // TODO: should be per-vpn |
552 | static u16 dns_id = 0; // TODO: should be per-vpn |
| 523 | |
553 | |
| 524 | static u16 next_id () |
|
|
| 525 | { |
|
|
| 526 | if (!dns_id) |
554 | if (!dns_id) |
| 527 | dns_id = time (0); |
555 | dns_id = time (0); |
| 528 | |
556 | |
| 529 | // the simplest lsfr with periodicity 65535 i could find |
557 | // the simplest lsfr with periodicity 65535 i could find |
| 530 | dns_id = (dns_id << 1) |
558 | dns_id = (dns_id << 1) |
| … | |
… | |
| 553 | double min_latency; |
581 | double min_latency; |
| 554 | double poll_interval, send_interval; |
582 | double poll_interval, send_interval; |
| 555 | |
583 | |
| 556 | vector<dns_rcv *> rcvpq; |
584 | vector<dns_rcv *> rcvpq; |
| 557 | |
585 | |
| 558 | byte_stream rcvdq; int rcvseq; |
586 | byte_stream rcvdq; int rcvseq; int repseq; |
| 559 | byte_stream snddq; int sndseq; |
587 | byte_stream snddq; int sndseq; |
| 560 | |
588 | |
| 561 | void time_cb (time_watcher &w); time_watcher tw; |
589 | inline void time_cb (ev::timer &w, int revents); ev::timer tw; |
| 562 | void receive_rep (dns_rcv *r); |
590 | void receive_rep (dns_rcv *r); |
| 563 | |
591 | |
| 564 | dns_connection (connection *c); |
592 | dns_connection (connection *c); |
| 565 | ~dns_connection (); |
593 | ~dns_connection (); |
| 566 | }; |
594 | }; |
| … | |
… | |
| 585 | : dns (dns) |
613 | : dns (dns) |
| 586 | { |
614 | { |
| 587 | timeout = 0; |
615 | timeout = 0; |
| 588 | retry = 0; |
616 | retry = 0; |
| 589 | seqno = 0; |
617 | seqno = 0; |
| 590 | sent = NOW; |
618 | sent = ev_now (); |
| 591 | stdhdr = false; |
619 | stdhdr = false; |
| 592 | |
620 | |
| 593 | pkt = new dns_packet; |
621 | pkt = new dns_packet; |
| 594 | |
622 | |
| 595 | pkt->id = next_id (); |
623 | pkt->id = next_id (); |
| … | |
… | |
| 598 | dns_snd::~dns_snd () |
626 | dns_snd::~dns_snd () |
| 599 | { |
627 | { |
| 600 | delete pkt; |
628 | delete pkt; |
| 601 | } |
629 | } |
| 602 | |
630 | |
|
|
631 | static void |
| 603 | static void append_domain (dns_packet &pkt, int &offs, const char *domain) |
632 | append_domain (dns_packet &pkt, int &offs, const char *domain) |
| 604 | { |
633 | { |
| 605 | // add tunnel domain |
634 | // add tunnel domain |
| 606 | for (;;) |
635 | for (;;) |
| 607 | { |
636 | { |
| 608 | const char *end = strchr (domain, '.'); |
637 | const char *end = strchr (domain, '.'); |
| … | |
… | |
| 621 | |
650 | |
| 622 | domain = end + 1; |
651 | domain = end + 1; |
| 623 | } |
652 | } |
| 624 | } |
653 | } |
| 625 | |
654 | |
|
|
655 | void |
| 626 | void dns_snd::gen_stream_req (int seqno, byte_stream &stream) |
656 | dns_snd::gen_stream_req (int seqno, byte_stream &stream) |
| 627 | { |
657 | { |
| 628 | stdhdr = true; |
658 | stdhdr = true; |
| 629 | this->seqno = seqno; |
659 | this->seqno = seqno; |
| 630 | |
660 | |
| 631 | timeout = NOW + INITIAL_TIMEOUT; |
661 | timeout = ev_now () + INITIAL_TIMEOUT; |
| 632 | |
662 | |
| 633 | pkt->flags = htons (DEFAULT_CLIENT_FLAGS); |
663 | pkt->flags = htons (DEFAULT_CLIENT_FLAGS); |
| 634 | pkt->qdcount = htons (1); |
664 | pkt->qdcount = htons (1); |
| 635 | |
665 | |
| 636 | int offs = 6*2; |
666 | int offs = 6*2; |
| … | |
… | |
| 669 | (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN; |
699 | (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN; |
| 670 | |
700 | |
| 671 | pkt->len = offs; |
701 | pkt->len = offs; |
| 672 | } |
702 | } |
| 673 | |
703 | |
|
|
704 | void |
| 674 | void dns_snd::gen_syn_req () |
705 | dns_snd::gen_syn_req () |
| 675 | { |
706 | { |
| 676 | timeout = NOW + INITIAL_SYN_TIMEOUT; |
707 | timeout = ev_now () + INITIAL_SYN_TIMEOUT; |
| 677 | |
708 | |
| 678 | pkt->flags = htons (DEFAULT_CLIENT_FLAGS); |
709 | pkt->flags = htons (DEFAULT_CLIENT_FLAGS); |
| 679 | pkt->qdcount = htons (1); |
710 | pkt->qdcount = htons (1); |
| 680 | |
711 | |
| 681 | int offs = 6 * 2; |
712 | int offs = 6 * 2; |
| … | |
… | |
| 720 | ///////////////////////////////////////////////////////////////////////////// |
751 | ///////////////////////////////////////////////////////////////////////////// |
| 721 | |
752 | |
| 722 | dns_connection::dns_connection (connection *c) |
753 | dns_connection::dns_connection (connection *c) |
| 723 | : c (c) |
754 | : c (c) |
| 724 | , rcvdq (MAX_BACKLOG * 2) |
755 | , rcvdq (MAX_BACKLOG * 2) |
| 725 | , snddq (MAX_BACKLOG * 2) |
756 | , snddq (MAX_BACKLOG) |
| 726 | , tw (this, &dns_connection::time_cb) |
|
|
| 727 | { |
757 | { |
|
|
758 | tw.set<dns_connection, &dns_connection::time_cb> (this); |
|
|
759 | |
| 728 | vpn = c->vpn; |
760 | vpn = c->vpn; |
| 729 | |
761 | |
| 730 | established = false; |
762 | established = false; |
| 731 | |
763 | |
| 732 | rcvseq = sndseq = 0; |
764 | rcvseq = repseq = sndseq = 0; |
| 733 | |
765 | |
| 734 | last_sent = last_received = 0; |
766 | last_sent = last_received = 0; |
| 735 | poll_interval = 0.5; // starting here |
767 | poll_interval = 0.5; // starting here |
| 736 | send_interval = 0.5; // starting rate |
768 | send_interval = 0.5; // starting rate |
| 737 | min_latency = INITIAL_TIMEOUT; |
769 | min_latency = INITIAL_TIMEOUT; |
| … | |
… | |
| 743 | i != rcvpq.end (); |
775 | i != rcvpq.end (); |
| 744 | ++i) |
776 | ++i) |
| 745 | delete *i; |
777 | delete *i; |
| 746 | } |
778 | } |
| 747 | |
779 | |
|
|
780 | void |
| 748 | void dns_connection::receive_rep (dns_rcv *r) |
781 | dns_connection::receive_rep (dns_rcv *r) |
| 749 | { |
782 | { |
| 750 | if (r->datalen) |
783 | if (r->datalen) |
| 751 | { |
784 | { |
| 752 | last_received = NOW; |
785 | last_received = ev_now (); |
| 753 | tw.trigger (); |
786 | tw (); |
| 754 | |
787 | |
| 755 | poll_interval = send_interval; |
788 | poll_interval = send_interval; |
| 756 | } |
789 | } |
| 757 | else |
790 | else |
| 758 | { |
791 | { |
| … | |
… | |
| 768 | |
801 | |
| 769 | // find next packet |
802 | // find next packet |
| 770 | for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); ) |
803 | for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); ) |
| 771 | if (SEQNO_EQ (rcvseq, (*i)->seqno)) |
804 | if (SEQNO_EQ (rcvseq, (*i)->seqno)) |
| 772 | { |
805 | { |
|
|
806 | //printf ("seqno eq %x %x\n", rcvseq, (*i)->seqno);//D |
| 773 | // enter the packet into our input stream |
807 | // enter the packet into our input stream |
| 774 | r = *i; |
808 | r = *i; |
| 775 | |
809 | |
| 776 | // remove the oldest packet, look forward, as it's oldest first |
810 | // remove the oldest packet, look forward, as it's oldest first |
| 777 | for (vector<dns_rcv *>::iterator j = rcvpq.begin (); j != rcvpq.end (); ++j) |
811 | for (vector<dns_rcv *>::iterator j = rcvpq.begin (); j != rcvpq.end (); ++j) |
| 778 | if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW)) |
812 | if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW)) |
| 779 | { |
813 | { |
|
|
814 | //printf ("seqno RR %x %x\n", (*j)->seqno, rcvseq - MAX_WINDOW);//D |
| 780 | delete *j; |
815 | delete *j; |
| 781 | rcvpq.erase (j); |
816 | rcvpq.erase (j); |
| 782 | break; |
817 | break; |
| 783 | } |
818 | } |
| 784 | |
819 | |
| … | |
… | |
| 791 | } |
826 | } |
| 792 | |
827 | |
| 793 | while (vpn_packet *pkt = rcvdq.get ()) |
828 | while (vpn_packet *pkt = rcvdq.get ()) |
| 794 | { |
829 | { |
| 795 | sockinfo si; |
830 | sockinfo si; |
| 796 | si.host = 0x01010101; si.port = htons (c->conf->id); si.prot = PROT_DNSv4; |
831 | si.host = htonl (c->conf->id); si.port = 0; si.prot = PROT_DNSv4; |
| 797 | |
832 | |
| 798 | vpn->recv_vpn_packet (pkt, si); |
833 | vpn->recv_vpn_packet (pkt, si); |
| 799 | |
834 | |
| 800 | delete pkt; |
835 | delete pkt; |
| 801 | } |
836 | } |
| … | |
… | |
| 855 | if (0 < client && client <= conns.size ()) |
890 | if (0 < client && client <= conns.size ()) |
| 856 | { |
891 | { |
| 857 | connection *c = conns [client - 1]; |
892 | connection *c = conns [client - 1]; |
| 858 | dns_connection *dns = c->dns; |
893 | dns_connection *dns = c->dns; |
| 859 | dns_rcv *rcv; |
894 | dns_rcv *rcv; |
| 860 | bool in_seq; |
|
|
| 861 | |
895 | |
| 862 | if (dns) |
896 | if (dns) |
| 863 | { |
897 | { |
| 864 | for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); ) |
898 | for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); ) |
| 865 | if (SEQNO_EQ ((*i)->seqno, seqno)) |
899 | if (SEQNO_EQ ((*i)->seqno, seqno)) |
| … | |
… | |
| 876 | memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len); |
910 | memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len); |
| 877 | |
911 | |
| 878 | goto duplicate_request; |
912 | goto duplicate_request; |
| 879 | } |
913 | } |
| 880 | |
914 | |
| 881 | in_seq = dns->rcvseq == seqno; |
|
|
| 882 | |
|
|
| 883 | // new packet, queue |
915 | // new packet, queue |
| 884 | rcv = new dns_rcv (seqno, data, datalen); |
916 | rcv = new dns_rcv (seqno, data, datalen); |
| 885 | dns->receive_rep (rcv); |
917 | dns->receive_rep (rcv); |
| 886 | } |
918 | } |
| 887 | |
919 | |
| … | |
… | |
| 904 | dlen -= qlen; |
936 | dlen -= qlen; |
| 905 | |
937 | |
| 906 | // only put data into in-order sequence packets, if |
938 | // only put data into in-order sequence packets, if |
| 907 | // we receive out-of-order packets we generate empty |
939 | // we receive out-of-order packets we generate empty |
| 908 | // replies |
940 | // replies |
| 909 | while (dlen > 1 && !dns->snddq.empty () && in_seq) |
941 | //printf ("%d - %d & %x (=%d) < %d\n", seqno, dns->repseq, SEQNO_MASK, (seqno - dns->repseq) & SEQNO_MASK, MAX_WINDOW);//D |
|
|
942 | if (((seqno - dns->repseq) & SEQNO_MASK) <= MAX_WINDOW) |
| 910 | { |
943 | { |
|
|
944 | dns->repseq = seqno; |
|
|
945 | |
|
|
946 | while (dlen > 1 && !dns->snddq.empty ()) |
|
|
947 | { |
| 911 | int txtlen = dlen <= 255 ? dlen - 1 : 255; |
948 | int txtlen = dlen <= 255 ? dlen - 1 : 255; |
| 912 | |
949 | |
| 913 | if (txtlen > dns->snddq.size ()) |
950 | if (txtlen > dns->snddq.size ()) |
| 914 | txtlen = dns->snddq.size (); |
951 | txtlen = dns->snddq.size (); |
| 915 | |
952 | |
| 916 | pkt[offs++] = txtlen; |
953 | pkt[offs++] = txtlen; |
| 917 | memcpy (pkt.at (offs), dns->snddq.begin (), txtlen); |
954 | memcpy (pkt.at (offs), dns->snddq.begin (), txtlen); |
| 918 | offs += txtlen; |
955 | offs += txtlen; |
| 919 | dns->snddq.remove (txtlen); |
956 | dns->snddq.remove (txtlen); |
| 920 | |
957 | |
| 921 | dlen -= txtlen + 1; |
958 | dlen -= txtlen + 1; |
|
|
959 | } |
| 922 | } |
960 | } |
| 923 | |
961 | |
| 924 | // avoid empty TXT rdata |
962 | // avoid completely empty TXT rdata |
| 925 | if (offs == rdlen_offs) |
963 | if (offs == rdlen_offs) |
| 926 | pkt[offs++] = 0; |
964 | pkt[offs++] = 0; |
| 927 | |
965 | |
| 928 | slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ()); |
966 | slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ()); |
| 929 | } |
967 | } |
| … | |
… | |
| 1009 | { |
1047 | { |
| 1010 | dns_connection *dns = (*i)->dns; |
1048 | dns_connection *dns = (*i)->dns; |
| 1011 | connection *c = dns->c; |
1049 | connection *c = dns->c; |
| 1012 | int seqno = (*i)->seqno; |
1050 | int seqno = (*i)->seqno; |
| 1013 | u8 data[MAXSIZE], *datap = data; |
1051 | u8 data[MAXSIZE], *datap = data; |
|
|
1052 | //printf ("rcv pkt %x\n", seqno);//D |
| 1014 | |
1053 | |
| 1015 | if ((*i)->retry) |
1054 | if ((*i)->retry) |
| 1016 | { |
1055 | { |
| 1017 | dns->send_interval *= 1.01; |
1056 | dns->send_interval *= 1.01; |
| 1018 | if (dns->send_interval > MAX_SEND_INTERVAL) |
1057 | if (dns->send_interval > MAX_SEND_INTERVAL) |
| … | |
… | |
| 1023 | #if 0 |
1062 | #if 0 |
| 1024 | dns->send_interval *= 0.999; |
1063 | dns->send_interval *= 0.999; |
| 1025 | #endif |
1064 | #endif |
| 1026 | // the latency surely puts an upper bound on |
1065 | // the latency surely puts an upper bound on |
| 1027 | // the minimum send interval |
1066 | // the minimum send interval |
| 1028 | double latency = NOW - (*i)->sent; |
1067 | double latency = ev_now () - (*i)->sent; |
| 1029 | |
1068 | |
| 1030 | if (latency < dns->min_latency) |
1069 | if (latency < dns->min_latency) |
| 1031 | dns->min_latency = latency; |
1070 | dns->min_latency = latency; |
| 1032 | |
1071 | |
| 1033 | if (dns->send_interval > dns->min_latency * LATENCY_FACTOR) |
1072 | if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor) |
| 1034 | dns->send_interval = dns->min_latency * LATENCY_FACTOR; |
1073 | dns->send_interval = dns->min_latency * conf.dns_overlap_factor; |
| 1035 | |
1074 | |
| 1036 | if (dns->send_interval < MIN_SEND_INTERVAL) |
1075 | if (dns->send_interval < conf.dns_send_interval) |
| 1037 | dns->send_interval = MIN_SEND_INTERVAL; |
1076 | dns->send_interval = conf.dns_send_interval; |
| 1038 | } |
1077 | } |
| 1039 | |
1078 | |
| 1040 | delete *i; |
1079 | delete *i; |
| 1041 | dns_sndpq.erase (i); |
1080 | dns_sndpq.erase (i); |
| 1042 | |
1081 | |
| … | |
… | |
| 1147 | break; |
1186 | break; |
| 1148 | } |
1187 | } |
| 1149 | } |
1188 | } |
| 1150 | |
1189 | |
| 1151 | void |
1190 | void |
| 1152 | vpn::dnsv4_ev (io_watcher &w, short revents) |
1191 | vpn::dnsv4_ev (ev::io &w, int revents) |
| 1153 | { |
1192 | { |
| 1154 | if (revents & EVENT_READ) |
1193 | if (revents & EV_READ) |
| 1155 | { |
1194 | { |
| 1156 | dns_packet *pkt = new dns_packet; |
1195 | dns_packet *pkt = new dns_packet; |
| 1157 | struct sockaddr_in sa; |
1196 | struct sockaddr_in sa; |
| 1158 | socklen_t sa_len = sizeof (sa); |
1197 | socklen_t sa_len = sizeof (sa); |
| 1159 | |
1198 | |
| … | |
… | |
| 1175 | } |
1214 | } |
| 1176 | |
1215 | |
| 1177 | bool |
1216 | bool |
| 1178 | vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) |
1217 | vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) |
| 1179 | { |
1218 | { |
| 1180 | int client = ntohs (si.port); |
1219 | int client = ntohl (si.host); |
| 1181 | |
1220 | |
| 1182 | assert (0 < client && client <= conns.size ()); |
1221 | assert (0 < client && client <= conns.size ()); |
| 1183 | |
1222 | |
| 1184 | connection *c = conns [client - 1]; |
1223 | connection *c = conns [client - 1]; |
| 1185 | |
1224 | |
| 1186 | if (!c->dns) |
1225 | if (!c->dns) |
| 1187 | c->dns = new dns_connection (c); |
1226 | c->dns = new dns_connection (c); |
| 1188 | |
1227 | |
| 1189 | if (!c->dns->snddq.put (pkt)) |
1228 | if (c->dns->snddq.put (pkt)) |
| 1190 | return false; |
|
|
| 1191 | |
|
|
| 1192 | c->dns->tw.trigger (); |
1229 | c->dns->tw (); |
| 1193 | |
1230 | |
|
|
1231 | // always return true even if the buffer overflows |
| 1194 | return true; |
1232 | return true; |
| 1195 | } |
1233 | } |
| 1196 | |
1234 | |
| 1197 | void |
1235 | void |
| 1198 | connection::dnsv4_reset_connection () |
1236 | connection::dnsv4_reset_connection () |
| … | |
… | |
| 1201 | } |
1239 | } |
| 1202 | |
1240 | |
| 1203 | #define NEXT(w) do { if (next > (w)) next = w; } while (0) |
1241 | #define NEXT(w) do { if (next > (w)) next = w; } while (0) |
| 1204 | |
1242 | |
| 1205 | void |
1243 | void |
| 1206 | dns_connection::time_cb (time_watcher &w) |
1244 | dns_connection::time_cb (ev::timer &w, int revents) |
| 1207 | { |
1245 | { |
| 1208 | // servers have to be polled |
1246 | // servers have to be polled |
| 1209 | if (THISNODE->dns_port) |
1247 | if (THISNODE->dns_port) |
| 1210 | return; |
1248 | return; |
| 1211 | |
1249 | |
| 1212 | // check for timeouts and (re)transmit |
1250 | // check for timeouts and (re)transmit |
| 1213 | tstamp next = NOW + poll_interval; |
1251 | tstamp next = ev::now () + poll_interval; |
| 1214 | dns_snd *send = 0; |
1252 | dns_snd *send = 0; |
| 1215 | |
1253 | |
| 1216 | for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin (); |
1254 | for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin (); |
| 1217 | i != vpn->dns_sndpq.end (); |
1255 | i != vpn->dns_sndpq.end (); |
| 1218 | ++i) |
1256 | ++i) |
| 1219 | { |
1257 | { |
| 1220 | dns_snd *r = *i; |
1258 | dns_snd *r = *i; |
| 1221 | |
1259 | |
| 1222 | if (r->timeout <= NOW) |
1260 | if (r->timeout <= ev_now ()) |
| 1223 | { |
1261 | { |
| 1224 | if (!send) |
1262 | if (!send) |
| 1225 | { |
1263 | { |
| 1226 | send = r; |
1264 | send = r; |
| 1227 | |
1265 | |
| 1228 | r->retry++; |
1266 | r->retry++; |
| 1229 | r->timeout = NOW + (r->retry * min_latency * 8.); |
1267 | r->timeout = ev_now () + (r->retry * min_latency * conf.dns_timeout_factor); |
|
|
1268 | //printf ("RETRY %x (%d, %f)\n", r->seqno, r->retry, r->timeout - ev_now ());//D |
| 1230 | |
1269 | |
| 1231 | // the following code changes the query section a bit, forcing |
1270 | // the following code changes the query section a bit, forcing |
| 1232 | // the forwarder to generate a new request |
1271 | // the forwarder to generate a new request |
| 1233 | if (r->stdhdr) |
1272 | if (r->stdhdr) |
| 1234 | { |
|
|
| 1235 | //printf ("reencoded header for ID %d retry %d:%d:%d (%p)\n", htons (r->pkt->id), THISNODE->id, r->seqno, r->retry); |
|
|
| 1236 | //encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry); |
1273 | encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry); |
| 1237 | } |
|
|
| 1238 | } |
1274 | } |
| 1239 | } |
1275 | } |
| 1240 | else |
1276 | else |
| 1241 | NEXT (r->timeout); |
1277 | NEXT (r->timeout); |
| 1242 | } |
1278 | } |
| … | |
… | |
| 1253 | |
1289 | |
| 1254 | cfg.reset (THISNODE->id); |
1290 | cfg.reset (THISNODE->id); |
| 1255 | send->gen_syn_req (); |
1291 | send->gen_syn_req (); |
| 1256 | } |
1292 | } |
| 1257 | } |
1293 | } |
| 1258 | else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING |
1294 | else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding |
| 1259 | && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) |
1295 | && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) |
| 1260 | { |
1296 | { |
| 1261 | if (last_sent + send_interval <= NOW) |
1297 | if (last_sent + send_interval <= ev_now ()) |
| 1262 | { |
1298 | { |
| 1263 | //printf ("sending data request etc.\n"); //D |
1299 | //printf ("sending data request etc.\n"); //D |
| 1264 | if (!snddq.empty () || last_received + 1. > NOW) |
1300 | if (!snddq.empty () || last_received + 1. > ev_now ()) |
| 1265 | { |
1301 | { |
| 1266 | poll_interval = send_interval; |
1302 | poll_interval = send_interval; |
| 1267 | NEXT (NOW + send_interval); |
1303 | NEXT (ev_now () + send_interval); |
| 1268 | } |
1304 | } |
| 1269 | |
1305 | |
| 1270 | send = new dns_snd (this); |
1306 | send = new dns_snd (this); |
| 1271 | send->gen_stream_req (sndseq, snddq); |
1307 | send->gen_stream_req (sndseq, snddq); |
| 1272 | send->timeout = NOW + min_latency * 8.; |
1308 | send->timeout = ev_now () + min_latency * conf.dns_timeout_factor; |
|
|
1309 | //printf ("SEND %x (%f)\n", send->seqno, send->timeout - ev_now (), min_latency, conf.dns_timeout_factor);//D |
| 1273 | |
1310 | |
| 1274 | sndseq = (sndseq + 1) & SEQNO_MASK; |
1311 | sndseq = (sndseq + 1) & SEQNO_MASK; |
| 1275 | } |
1312 | } |
| 1276 | else |
1313 | else |
| 1277 | NEXT (last_sent + send_interval); |
1314 | NEXT (last_sent + send_interval); |
| … | |
… | |
| 1281 | vpn->dns_sndpq.push_back (send); |
1318 | vpn->dns_sndpq.push_back (send); |
| 1282 | } |
1319 | } |
| 1283 | |
1320 | |
| 1284 | if (send) |
1321 | if (send) |
| 1285 | { |
1322 | { |
| 1286 | last_sent = NOW; |
1323 | last_sent = ev_now (); |
| 1287 | sendto (vpn->dnsv4_fd, |
1324 | sendto (vpn->dnsv4_fd, |
| 1288 | send->pkt->at (0), send->pkt->len, 0, |
1325 | send->pkt->at (0), send->pkt->len, 0, |
| 1289 | vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); |
1326 | vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); |
| 1290 | } |
1327 | } |
| 1291 | |
1328 | |
| 1292 | slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)", |
1329 | slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)", |
| 1293 | poll_interval, send_interval, next - NOW, |
1330 | poll_interval, send_interval, next - ev_now (), |
| 1294 | vpn->dns_sndpq.size (), snddq.size (), |
1331 | vpn->dns_sndpq.size (), snddq.size (), |
| 1295 | rcvpq.size ()); |
1332 | rcvpq.size ()); |
| 1296 | |
1333 | |
| 1297 | // TODO: no idea when this happens, but when next < NOW, we have a problem |
1334 | // TODO: no idea when this happens, but when next < ev_now (), we have a problem |
|
|
1335 | // doesn't seem to happen anymore |
| 1298 | if (next < NOW + 0.001) |
1336 | if (next < ev_now () + 0.001) |
| 1299 | next = NOW + 0.1; |
1337 | next = ev_now () + 0.1; |
| 1300 | |
1338 | |
| 1301 | w.start (next); |
1339 | w.start (next - ev_now ()); |
| 1302 | } |
1340 | } |
| 1303 | |
1341 | |
| 1304 | #endif |
1342 | #endif |
| 1305 | |
1343 | |
