… | |
… | |
25 | |
25 | |
26 | // dns processing is EXTREMELY ugly. For obvious(?) reasons. |
26 | // dns processing is EXTREMELY ugly. For obvious(?) reasons. |
27 | // it's a hack, use only in emergency situations please. |
27 | // it's a hack, use only in emergency situations please. |
28 | |
28 | |
29 | #include <cstring> |
29 | #include <cstring> |
|
|
30 | #include <cassert> |
30 | |
31 | |
31 | #include <sys/types.h> |
32 | #include <sys/types.h> |
32 | #include <sys/socket.h> |
33 | #include <sys/socket.h> |
33 | #include <sys/wait.h> |
34 | #include <sys/wait.h> |
34 | #include <sys/uio.h> |
35 | #include <sys/uio.h> |
… | |
… | |
43 | |
44 | |
44 | #include "netcompat.h" |
45 | #include "netcompat.h" |
45 | |
46 | |
46 | #include "vpn.h" |
47 | #include "vpn.h" |
47 | |
48 | |
48 | #define MIN_POLL_INTERVAL .02 // how often to poll minimally when the server is having data |
|
|
49 | #define MAX_POLL_INTERVAL 6. // how often to poll minimally when the server has no data |
49 | #define MAX_POLL_INTERVAL 5. // how often to poll minimally when the server has no data |
50 | #define ACTIVITY_INTERVAL 5. |
50 | #define ACTIVITY_INTERVAL 5. |
51 | |
51 | |
52 | #define INITIAL_TIMEOUT 1. |
52 | #define INITIAL_TIMEOUT 0.1 // retry timeouts |
53 | #define INITIAL_SYN_TIMEOUT 2. |
53 | #define INITIAL_SYN_TIMEOUT 2. // retry timeout for initial syn |
54 | |
54 | |
55 | #define MIN_SEND_INTERVAL 0.01 |
|
|
56 | #define MAX_SEND_INTERVAL 0.5 // optimistic? |
55 | #define MAX_SEND_INTERVAL 2. // optimistic? |
57 | |
56 | |
58 | #define MAX_OUTSTANDING 800 // max. outstanding requests |
|
|
59 | #define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING |
57 | #define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog |
60 | #define MAX_BACKLOG (100*1024) // size of protocol backlog, must be > MAXSIZE |
58 | #define MAX_BACKLOG (64*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE |
61 | |
59 | |
62 | #define MAX_DOMAIN_SIZE 220 // 255 is legal limit, but bind doesn't compress well |
60 | #define MAX_DOMAIN_SIZE 240 // 255 is legal limit, but bind doesn't compress well |
63 | // 240 leaves about 4 bytes of server reply data |
61 | // 240 leaves about 4 bytes of server reply data |
64 | // every two request byte sless give room for one reply byte |
62 | // every request byte less give room for two reply bytes |
65 | |
63 | |
66 | #define SEQNO_MASK 0xffff |
64 | #define SEQNO_MASK 0x3fff |
67 | #define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) ) |
65 | #define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) ) |
68 | |
66 | |
69 | #define MAX_LBL_SIZE 63 |
67 | #define MAX_LBL_SIZE 63 |
70 | #define MAX_PKT_SIZE 512 |
68 | #define MAX_PKT_SIZE 512 |
71 | |
69 | |
… | |
… | |
264 | static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO"); |
262 | static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO"); |
265 | |
263 | |
266 | ///////////////////////////////////////////////////////////////////////////// |
264 | ///////////////////////////////////////////////////////////////////////////// |
267 | |
265 | |
268 | #define HDRSIZE 6 |
266 | #define HDRSIZE 6 |
269 | |
267 | |
270 | inline void encode_header (char *data, int clientid, int seqno) |
268 | inline void encode_header (char *data, int clientid, int seqno, int retry = 0) |
271 | { |
269 | { |
272 | u8 hdr[3] = { clientid, seqno >> 8, seqno }; |
270 | seqno &= SEQNO_MASK; |
|
|
271 | |
|
|
272 | u8 hdr[3] = { |
|
|
273 | clientid, |
|
|
274 | (seqno >> 8) | (retry << 6), |
|
|
275 | seqno, |
|
|
276 | }; |
273 | |
277 | |
274 | assert (clientid < 256); |
278 | assert (clientid < 256); |
275 | |
279 | |
276 | cdc26.encode (data, hdr, 3); |
280 | cdc26.encode (data, hdr, 3); |
277 | } |
281 | } |
… | |
… | |
281 | u8 hdr[3]; |
285 | u8 hdr[3]; |
282 | |
286 | |
283 | cdc26.decode (hdr, data, HDRSIZE); |
287 | cdc26.decode (hdr, data, HDRSIZE); |
284 | |
288 | |
285 | clientid = hdr[0]; |
289 | clientid = hdr[0]; |
286 | seqno = (hdr[1] << 8) | hdr[2]; |
290 | seqno = ((hdr[1] << 8) | hdr[2]) & SEQNO_MASK; |
287 | } |
291 | } |
288 | |
292 | |
289 | ///////////////////////////////////////////////////////////////////////////// |
293 | ///////////////////////////////////////////////////////////////////////////// |
290 | |
294 | |
291 | struct byte_stream |
295 | struct byte_stream |
… | |
… | |
320 | } |
324 | } |
321 | |
325 | |
322 | void byte_stream::remove (int count) |
326 | void byte_stream::remove (int count) |
323 | { |
327 | { |
324 | if (count > fill) |
328 | if (count > fill) |
325 | abort (); |
329 | assert (count <= fill); |
326 | |
330 | |
327 | memmove (data, data + count, fill -= count); |
331 | memmove (data, data + count, fill -= count); |
328 | } |
332 | } |
329 | |
333 | |
330 | bool byte_stream::put (u8 *data, unsigned int datalen) |
334 | bool byte_stream::put (u8 *data, unsigned int datalen) |
… | |
… | |
350 | return true; |
354 | return true; |
351 | } |
355 | } |
352 | |
356 | |
353 | vpn_packet *byte_stream::get () |
357 | vpn_packet *byte_stream::get () |
354 | { |
358 | { |
|
|
359 | unsigned int len; |
|
|
360 | |
|
|
361 | for (;;) |
|
|
362 | { |
355 | unsigned int len = (data [0] << 8) | data [1]; |
363 | len = (data [0] << 8) | data [1]; |
356 | |
364 | |
357 | if (len > MAXSIZE && fill >= 2) |
365 | if (len <= MAXSIZE || fill < 2) |
358 | abort (); // TODO handle this gracefully, connection reset |
366 | break; |
359 | |
367 | |
|
|
368 | // TODO: handle this better than skipping, e.g. by reset |
|
|
369 | slog (L_DEBUG, _("DNS: corrupted packet stream skipping a byte...")); |
|
|
370 | remove (1); |
|
|
371 | } |
|
|
372 | |
360 | if (fill < len + 2) |
373 | if (fill < len + 2) |
361 | return 0; |
374 | return 0; |
362 | |
375 | |
363 | vpn_packet *pkt = new vpn_packet; |
376 | vpn_packet *pkt = new vpn_packet; |
364 | |
377 | |
… | |
… | |
393 | struct dns_cfg |
406 | struct dns_cfg |
394 | { |
407 | { |
395 | static int next_uid; |
408 | static int next_uid; |
396 | |
409 | |
397 | u8 id1, id2, id3, id4; |
410 | u8 id1, id2, id3, id4; |
|
|
411 | |
398 | u8 version; |
412 | u8 version; |
|
|
413 | u8 flags; |
399 | u8 rrtype; |
414 | u8 rrtype; |
400 | u8 flags; |
|
|
401 | u8 def_ttl; |
415 | u8 def_ttl; |
402 | u8 rcv_cdc; |
416 | |
403 | u8 snd_cdc; |
|
|
404 | u16 max_size; |
|
|
405 | u16 client; |
417 | u16 client; |
406 | u16 uid; // to make request unique |
418 | u16 uid; // to make request unique |
407 | |
419 | |
408 | u8 reserved[8]; |
420 | u16 max_size; |
|
|
421 | u8 seq_cdc; |
|
|
422 | u8 req_cdc; |
|
|
423 | |
|
|
424 | u8 rep_cdc; |
|
|
425 | u8 delay; // time in 0.01s units that the server may delay replying packets |
|
|
426 | u8 r3, r4; |
|
|
427 | |
|
|
428 | u8 r5, r6, r7, r8; |
409 | |
429 | |
410 | void reset (int clientid); |
430 | void reset (int clientid); |
411 | bool valid (); |
431 | bool valid (); |
412 | }; |
432 | }; |
413 | |
433 | |
… | |
… | |
423 | version = 1; |
443 | version = 1; |
424 | |
444 | |
425 | rrtype = RR_TYPE_TXT; |
445 | rrtype = RR_TYPE_TXT; |
426 | flags = 0; |
446 | flags = 0; |
427 | def_ttl = 0; |
447 | def_ttl = 0; |
|
|
448 | seq_cdc = 26; |
|
|
449 | req_cdc = 62; |
428 | rcv_cdc = 0; |
450 | rep_cdc = 0; |
429 | snd_cdc = 62; |
|
|
430 | max_size = ntohs (MAX_PKT_SIZE); |
451 | max_size = htons (MAX_PKT_SIZE); |
431 | client = ntohs (clientid); |
452 | client = htons (clientid); |
432 | uid = next_uid++; |
453 | uid = next_uid++; |
|
|
454 | delay = 0; |
433 | |
455 | |
434 | memset (reserved, 0, 8); |
456 | r3 = r4 = 0; |
|
|
457 | r4 = r5 = r6 = r7 = 0; |
435 | } |
458 | } |
436 | |
459 | |
437 | bool dns_cfg::valid () |
460 | bool dns_cfg::valid () |
438 | { |
461 | { |
439 | return id1 == 'G' |
462 | return id1 == 'G' |
440 | && id2 == 'V' |
463 | && id2 == 'V' |
441 | && id3 == 'P' |
464 | && id3 == 'P' |
442 | && id4 == 'E' |
465 | && id4 == 'E' |
|
|
466 | && seq_cdc == 26 |
|
|
467 | && req_cdc == 62 |
|
|
468 | && rep_cdc == 0 |
443 | && version == 1 |
469 | && version == 1; |
444 | && flags == 0 |
|
|
445 | && rcv_cdc == 0 |
|
|
446 | && snd_cdc == 62 |
|
|
447 | && max_size == ntohs (MAX_PKT_SIZE); |
|
|
448 | } |
470 | } |
449 | |
471 | |
450 | struct dns_packet : net_packet |
472 | struct dns_packet : net_packet |
451 | { |
473 | { |
452 | u16 id; |
474 | u16 id; |
453 | u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4 |
475 | u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4 |
454 | u16 qdcount, ancount, nscount, arcount; |
476 | u16 qdcount, ancount, nscount, arcount; |
455 | |
477 | |
456 | u8 data[MAXSIZE - 6 * 2]; |
478 | u8 data [MAXSIZE - 6 * 2]; |
457 | |
479 | |
458 | int decode_label (char *data, int size, int &offs); |
480 | int decode_label (char *data, int size, int &offs); |
459 | }; |
481 | }; |
460 | |
482 | |
461 | int dns_packet::decode_label (char *data, int size, int &offs) |
483 | int dns_packet::decode_label (char *data, int size, int &offs) |
… | |
… | |
492 | return data - orig; |
514 | return data - orig; |
493 | } |
515 | } |
494 | |
516 | |
495 | ///////////////////////////////////////////////////////////////////////////// |
517 | ///////////////////////////////////////////////////////////////////////////// |
496 | |
518 | |
497 | struct dns_snd |
|
|
498 | { |
|
|
499 | dns_packet *pkt; |
|
|
500 | tstamp timeout, sent; |
|
|
501 | int retry; |
|
|
502 | struct dns_connection *dns; |
|
|
503 | int seqno; |
|
|
504 | |
|
|
505 | void gen_stream_req (int seqno, byte_stream &stream); |
|
|
506 | void gen_syn_req (const dns_cfg &cfg); |
|
|
507 | |
|
|
508 | dns_snd (dns_connection *dns); |
|
|
509 | ~dns_snd (); |
|
|
510 | }; |
|
|
511 | |
|
|
512 | static u16 dns_id = 12098; // TODO: should be per-vpn |
519 | static u16 dns_id = 0; // TODO: should be per-vpn |
513 | |
520 | |
514 | static u16 next_id () |
521 | static u16 next_id () |
515 | { |
522 | { |
|
|
523 | if (!dns_id) |
|
|
524 | dns_id = time (0); |
|
|
525 | |
516 | // the simplest lsfr with periodicity 65535 i could find |
526 | // the simplest lsfr with periodicity 65535 i could find |
517 | dns_id = (dns_id << 1) |
527 | dns_id = (dns_id << 1) |
518 | | (((dns_id >> 1) |
528 | | (((dns_id >> 1) |
519 | ^ (dns_id >> 2) |
529 | ^ (dns_id >> 2) |
520 | ^ (dns_id >> 4) |
530 | ^ (dns_id >> 4) |
521 | ^ (dns_id >> 15)) & 1); |
531 | ^ (dns_id >> 15)) & 1); |
522 | |
532 | |
523 | return dns_id; |
533 | return dns_id; |
524 | } |
534 | } |
525 | |
535 | |
|
|
536 | struct dns_rcv; |
|
|
537 | struct dns_snd; |
|
|
538 | |
|
|
539 | struct dns_connection |
|
|
540 | { |
|
|
541 | connection *c; |
|
|
542 | struct vpn *vpn; |
|
|
543 | |
|
|
544 | dns_cfg cfg; |
|
|
545 | |
|
|
546 | bool established; |
|
|
547 | |
|
|
548 | tstamp last_received; |
|
|
549 | tstamp last_sent; |
|
|
550 | double min_latency; |
|
|
551 | double poll_interval, send_interval; |
|
|
552 | |
|
|
553 | vector<dns_rcv *> rcvpq; |
|
|
554 | |
|
|
555 | byte_stream rcvdq; int rcvseq; int repseq; |
|
|
556 | byte_stream snddq; int sndseq; |
|
|
557 | |
|
|
558 | void time_cb (time_watcher &w); time_watcher tw; |
|
|
559 | void receive_rep (dns_rcv *r); |
|
|
560 | |
|
|
561 | dns_connection (connection *c); |
|
|
562 | ~dns_connection (); |
|
|
563 | }; |
|
|
564 | |
|
|
565 | struct dns_snd |
|
|
566 | { |
|
|
567 | dns_packet *pkt; |
|
|
568 | tstamp timeout, sent; |
|
|
569 | int retry; |
|
|
570 | struct dns_connection *dns; |
|
|
571 | int seqno; |
|
|
572 | bool stdhdr; |
|
|
573 | |
|
|
574 | void gen_stream_req (int seqno, byte_stream &stream); |
|
|
575 | void gen_syn_req (); |
|
|
576 | |
|
|
577 | dns_snd (dns_connection *dns); |
|
|
578 | ~dns_snd (); |
|
|
579 | }; |
|
|
580 | |
526 | dns_snd::dns_snd (dns_connection *dns) |
581 | dns_snd::dns_snd (dns_connection *dns) |
527 | : dns (dns) |
582 | : dns (dns) |
528 | { |
583 | { |
529 | timeout = 0; |
584 | timeout = 0; |
530 | retry = 0; |
585 | retry = 0; |
531 | seqno = 0; |
586 | seqno = 0; |
532 | sent = NOW; |
587 | sent = NOW; |
|
|
588 | stdhdr = false; |
533 | |
589 | |
534 | pkt = new dns_packet; |
590 | pkt = new dns_packet; |
535 | |
591 | |
536 | pkt->id = next_id (); |
592 | pkt->id = next_id (); |
537 | } |
593 | } |
… | |
… | |
564 | } |
620 | } |
565 | } |
621 | } |
566 | |
622 | |
567 | void dns_snd::gen_stream_req (int seqno, byte_stream &stream) |
623 | void dns_snd::gen_stream_req (int seqno, byte_stream &stream) |
568 | { |
624 | { |
|
|
625 | stdhdr = true; |
569 | this->seqno = seqno; |
626 | this->seqno = seqno; |
570 | |
627 | |
571 | timeout = NOW + INITIAL_TIMEOUT; |
628 | timeout = NOW + INITIAL_TIMEOUT; |
572 | |
629 | |
573 | pkt->flags = htons (DEFAULT_CLIENT_FLAGS); |
630 | pkt->flags = htons (DEFAULT_CLIENT_FLAGS); |
574 | pkt->qdcount = htons (1); |
631 | pkt->qdcount = htons (1); |
575 | |
632 | |
576 | int offs = 6*2; |
633 | int offs = 6*2; |
577 | int dlen = MAX_DOMAIN_SIZE - (strlen (THISNODE->domain) + 2); |
634 | int dlen = MAX_DOMAIN_SIZE - (strlen (dns->c->conf->domain) + 2); |
578 | // MAX_DOMAIN_SIZE is technically 255, but bind doesn't compress responses well, |
635 | // MAX_DOMAIN_SIZE is technically 255, but bind doesn't compress responses well, |
579 | // so we need to have space for 2*MAX_DOMAIN_SIZE + header + extra |
636 | // so we need to have space for 2*MAX_DOMAIN_SIZE + header + extra |
580 | |
637 | |
581 | char enc[256], *encp = enc; |
638 | char enc[256], *encp = enc; |
582 | encode_header (enc, THISNODE->id, seqno); |
639 | encode_header (enc, THISNODE->id, seqno); |
… | |
… | |
600 | encp += lbllen; |
657 | encp += lbllen; |
601 | |
658 | |
602 | enclen -= lbllen; |
659 | enclen -= lbllen; |
603 | } |
660 | } |
604 | |
661 | |
605 | append_domain (*pkt, offs, THISNODE->domain); |
662 | append_domain (*pkt, offs, dns->c->conf->domain); |
606 | |
663 | |
607 | (*pkt)[offs++] = 0; |
664 | (*pkt)[offs++] = 0; |
608 | (*pkt)[offs++] = RR_TYPE_ANY >> 8; (*pkt)[offs++] = RR_TYPE_ANY; |
665 | (*pkt)[offs++] = RR_TYPE_ANY >> 8; (*pkt)[offs++] = RR_TYPE_ANY; |
609 | (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN; |
666 | (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN; |
610 | |
667 | |
611 | pkt->len = offs; |
668 | pkt->len = offs; |
612 | } |
669 | } |
613 | |
670 | |
614 | void dns_snd::gen_syn_req (const dns_cfg &cfg) |
671 | void dns_snd::gen_syn_req () |
615 | { |
672 | { |
616 | timeout = NOW + INITIAL_SYN_TIMEOUT; |
673 | timeout = NOW + INITIAL_SYN_TIMEOUT; |
617 | |
674 | |
618 | pkt->flags = htons (DEFAULT_CLIENT_FLAGS); |
675 | pkt->flags = htons (DEFAULT_CLIENT_FLAGS); |
619 | pkt->qdcount = htons (1); |
676 | pkt->qdcount = htons (1); |
620 | |
677 | |
621 | int offs = 6*2; |
678 | int offs = 6 * 2; |
622 | |
679 | |
623 | int elen = cdc26.encode ((char *)pkt->at (offs + 1), (u8 *)&cfg, sizeof (dns_cfg)); |
680 | int elen = cdc26.encode ((char *)pkt->at (offs + 1), (u8 *)&dns->cfg, sizeof (dns_cfg)); |
624 | |
681 | |
625 | assert (elen <= MAX_LBL_SIZE); |
682 | assert (elen <= MAX_LBL_SIZE); |
626 | |
683 | |
627 | (*pkt)[offs] = elen; |
684 | (*pkt)[offs] = elen; |
628 | offs += elen + 1; |
685 | offs += elen + 1; |
629 | append_domain (*pkt, offs, THISNODE->domain); |
686 | append_domain (*pkt, offs, dns->c->conf->domain); |
630 | |
687 | |
631 | (*pkt)[offs++] = 0; |
688 | (*pkt)[offs++] = 0; |
632 | (*pkt)[offs++] = RR_TYPE_A >> 8; (*pkt)[offs++] = RR_TYPE_A; |
689 | (*pkt)[offs++] = RR_TYPE_A >> 8; (*pkt)[offs++] = RR_TYPE_A; |
633 | (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN; |
690 | (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN; |
634 | |
691 | |
… | |
… | |
657 | delete pkt; |
714 | delete pkt; |
658 | } |
715 | } |
659 | |
716 | |
660 | ///////////////////////////////////////////////////////////////////////////// |
717 | ///////////////////////////////////////////////////////////////////////////// |
661 | |
718 | |
662 | struct dns_connection |
|
|
663 | { |
|
|
664 | connection *c; |
|
|
665 | struct vpn *vpn; |
|
|
666 | |
|
|
667 | dns_cfg cfg; |
|
|
668 | |
|
|
669 | bool established; |
|
|
670 | |
|
|
671 | tstamp last_received; |
|
|
672 | tstamp last_sent; |
|
|
673 | double poll_interval, send_interval; |
|
|
674 | |
|
|
675 | vector<dns_rcv *> rcvpq; |
|
|
676 | |
|
|
677 | byte_stream rcvdq; int rcvseq; |
|
|
678 | byte_stream snddq; int sndseq; |
|
|
679 | |
|
|
680 | void time_cb (time_watcher &w); time_watcher tw; |
|
|
681 | void receive_rep (dns_rcv *r); |
|
|
682 | |
|
|
683 | dns_connection (connection *c); |
|
|
684 | ~dns_connection (); |
|
|
685 | }; |
|
|
686 | |
|
|
687 | dns_connection::dns_connection (connection *c) |
719 | dns_connection::dns_connection (connection *c) |
688 | : c (c) |
720 | : c (c) |
689 | , rcvdq (MAX_BACKLOG * 2) |
721 | , rcvdq (MAX_BACKLOG * 2) |
690 | , snddq (MAX_BACKLOG * 2) |
722 | , snddq (MAX_BACKLOG) |
691 | , tw (this, &dns_connection::time_cb) |
723 | , tw (this, &dns_connection::time_cb) |
692 | { |
724 | { |
693 | vpn = c->vpn; |
725 | vpn = c->vpn; |
694 | |
726 | |
695 | established = false; |
727 | established = false; |
696 | |
728 | |
697 | rcvseq = sndseq = 0; |
729 | rcvseq = repseq = sndseq = 0; |
698 | |
730 | |
699 | last_sent = last_received = 0; |
731 | last_sent = last_received = 0; |
700 | poll_interval = MIN_POLL_INTERVAL; |
732 | poll_interval = 0.5; // starting here |
701 | send_interval = 0.2; // starting rate |
733 | send_interval = 0.5; // starting rate |
|
|
734 | min_latency = INITIAL_TIMEOUT; |
702 | } |
735 | } |
703 | |
736 | |
704 | dns_connection::~dns_connection () |
737 | dns_connection::~dns_connection () |
705 | { |
738 | { |
706 | for (vector<dns_rcv *>::iterator i = rcvpq.begin (); |
739 | for (vector<dns_rcv *>::iterator i = rcvpq.begin (); |
… | |
… | |
718 | |
751 | |
719 | poll_interval = send_interval; |
752 | poll_interval = send_interval; |
720 | } |
753 | } |
721 | else |
754 | else |
722 | { |
755 | { |
723 | poll_interval *= 1.1; |
756 | poll_interval *= 1.5; |
|
|
757 | |
724 | if (poll_interval > MAX_POLL_INTERVAL) |
758 | if (poll_interval > MAX_POLL_INTERVAL) |
725 | poll_interval = MAX_POLL_INTERVAL; |
759 | poll_interval = MAX_POLL_INTERVAL; |
726 | } |
760 | } |
727 | |
761 | |
728 | rcvpq.push_back (r); |
762 | rcvpq.push_back (r); |
… | |
… | |
746 | } |
780 | } |
747 | |
781 | |
748 | rcvseq = (rcvseq + 1) & SEQNO_MASK; |
782 | rcvseq = (rcvseq + 1) & SEQNO_MASK; |
749 | |
783 | |
750 | if (!rcvdq.put (r->data, r->datalen)) |
784 | if (!rcvdq.put (r->data, r->datalen)) |
|
|
785 | { |
|
|
786 | slog (L_ERR, "DNS: !rcvdq.put (r->data, r->datalen)"); |
751 | abort (); // MUST never overflow, can be caused by data corruption, TODO |
787 | abort (); // MUST never overflow, can be caused by data corruption, TODO |
|
|
788 | } |
752 | |
789 | |
753 | while (vpn_packet *pkt = rcvdq.get ()) |
790 | while (vpn_packet *pkt = rcvdq.get ()) |
754 | { |
791 | { |
755 | sockinfo si; |
792 | sockinfo si; |
756 | si.host = 0; si.port = 0; si.prot = PROT_DNSv4; |
793 | si.host = htonl (c->conf->id); si.port = 0; si.prot = PROT_DNSv4; |
757 | |
794 | |
758 | vpn->recv_vpn_packet (pkt, si); |
795 | vpn->recv_vpn_packet (pkt, si); |
759 | |
796 | |
760 | delete pkt; |
797 | delete pkt; |
761 | } |
798 | } |
… | |
… | |
775 | pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR); |
812 | pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR); |
776 | |
813 | |
777 | if (0 == (flags & (FLAG_RESPONSE | FLAG_OP_MASK)) |
814 | if (0 == (flags & (FLAG_RESPONSE | FLAG_OP_MASK)) |
778 | && pkt.qdcount == htons (1)) |
815 | && pkt.qdcount == htons (1)) |
779 | { |
816 | { |
780 | char qname[MAXSIZE]; |
817 | char qname [MAXSIZE]; |
781 | int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs); |
818 | int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs); |
782 | |
819 | |
783 | u16 qtype = pkt [offs++] << 8; qtype |= pkt [offs++]; |
820 | u16 qtype = pkt [offs++] << 8; qtype |= pkt [offs++]; |
784 | u16 qclass = pkt [offs++] << 8; qclass |= pkt [offs++]; |
821 | u16 qclass = pkt [offs++] << 8; qclass |= pkt [offs++]; |
785 | |
822 | |
786 | pkt.qdcount = htons (1); |
823 | pkt.qdcount = htons (1); |
787 | pkt.ancount = 0; |
824 | pkt.ancount = 0; |
788 | pkt.nscount = 0; // should be self, as other nameservers reply like this |
825 | pkt.nscount = 0; // should be self, as other nameservers reply like this |
789 | pkt.arcount = 0; // a record for self, as other nameservers reply like this |
826 | pkt.arcount = 0; // a record for self, as other nameservers reply like this |
790 | |
827 | |
791 | pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_NXDOMAIN); |
828 | pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_SERVFAIL); |
792 | |
829 | |
793 | int dlen = strlen (THISNODE->domain); |
830 | int dlen = strlen (THISNODE->domain); |
794 | |
831 | |
795 | if (qclass == RR_CLASS_IN |
832 | if (qclass == RR_CLASS_IN |
796 | && qlen > dlen + 1 |
833 | && qlen > dlen + 1 |
797 | && !memcmp (qname + qlen - dlen - 1, THISNODE->domain, dlen)) |
834 | && !memcmp (qname + qlen - (dlen + 1), THISNODE->domain, dlen)) |
798 | { |
835 | { |
799 | // now generate reply |
836 | // now generate reply |
800 | pkt.ancount = htons (1); // one answer RR |
837 | pkt.ancount = htons (1); // one answer RR |
801 | pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_OK); |
838 | pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_OK); |
802 | |
839 | |
… | |
… | |
824 | if (SEQNO_EQ ((*i)->seqno, seqno)) |
861 | if (SEQNO_EQ ((*i)->seqno, seqno)) |
825 | { |
862 | { |
826 | // already seen that request: simply reply with the cached reply |
863 | // already seen that request: simply reply with the cached reply |
827 | dns_rcv *r = *i; |
864 | dns_rcv *r = *i; |
828 | |
865 | |
829 | printf ("DUPLICATE %d\n", htons (r->pkt->id));//D |
866 | slog (L_DEBUG, "DNS: duplicate packet received ID %d, SEQ %d", htons (r->pkt->id), seqno); |
|
|
867 | |
|
|
868 | // refresh header & id, as the retry count could have changed |
|
|
869 | memcpy (r->pkt->at (6 * 2 + 1), pkt.at (6 * 2 + 1), HDRSIZE); |
|
|
870 | r->pkt->id = pkt.id; |
830 | |
871 | |
831 | memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len); |
872 | memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len); |
832 | pkt.id = r->pkt->id; |
873 | |
833 | goto duplicate_request; |
874 | goto duplicate_request; |
834 | } |
875 | } |
835 | |
876 | |
836 | // new packet, queue |
877 | // new packet, queue |
837 | rcv = new dns_rcv (seqno, data, datalen); |
878 | rcv = new dns_rcv (seqno, data, datalen); |
838 | dns->receive_rep (rcv); |
879 | dns->receive_rep (rcv); |
839 | } |
880 | } |
840 | |
881 | |
|
|
882 | { |
841 | pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section |
883 | pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section |
842 | |
884 | |
843 | int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A; |
885 | int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A; |
844 | pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type |
886 | pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type |
845 | pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class |
887 | pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class |
846 | pkt [offs++] = 0; pkt [offs++] = 0; |
888 | pkt [offs++] = 0; pkt [offs++] = 0; |
847 | pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL |
889 | pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL |
848 | |
890 | |
849 | int rdlen_offs = offs += 2; |
891 | int rdlen_offs = offs += 2; |
850 | |
892 | |
|
|
893 | if (dns) |
|
|
894 | { |
851 | int dlen = (dns ? ntohs (dns->cfg.max_size) : MAX_PKT_SIZE) - offs; |
895 | int dlen = ntohs (dns->cfg.max_size) - offs; |
|
|
896 | |
852 | // bind doesn't compress well, so reduce further by one label length |
897 | // bind doesn't compress well, so reduce further by one label length |
853 | dlen -= qlen; |
898 | dlen -= qlen; |
854 | |
899 | |
855 | if (dns) |
900 | // only put data into in-order sequence packets, if |
856 | { |
901 | // we receive out-of-order packets we generate empty |
857 | while (dlen > 1 && !dns->snddq.empty ()) |
902 | // replies |
|
|
903 | //printf ("%d - %d & %x (=%d) < %d\n", seqno, dns->repseq, SEQNO_MASK, (seqno - dns->repseq) & SEQNO_MASK, MAX_WINDOW);//D |
|
|
904 | if (((seqno - dns->repseq) & SEQNO_MASK) <= MAX_WINDOW) |
858 | { |
905 | { |
|
|
906 | dns->repseq = seqno; |
|
|
907 | |
|
|
908 | while (dlen > 1 && !dns->snddq.empty ()) |
|
|
909 | { |
859 | int txtlen = dlen <= 255 ? dlen - 1 : 255; |
910 | int txtlen = dlen <= 255 ? dlen - 1 : 255; |
860 | |
911 | |
861 | if (txtlen > dns->snddq.size ()) |
912 | if (txtlen > dns->snddq.size ()) |
862 | txtlen = dns->snddq.size (); |
913 | txtlen = dns->snddq.size (); |
863 | |
914 | |
864 | pkt[offs++] = txtlen; |
915 | pkt[offs++] = txtlen; |
865 | memcpy (pkt.at (offs), dns->snddq.begin (), txtlen); |
916 | memcpy (pkt.at (offs), dns->snddq.begin (), txtlen); |
866 | offs += txtlen; |
917 | offs += txtlen; |
867 | dns->snddq.remove (txtlen); |
918 | dns->snddq.remove (txtlen); |
868 | |
919 | |
869 | dlen -= txtlen + 1; |
920 | dlen -= txtlen + 1; |
|
|
921 | } |
870 | } |
922 | } |
871 | |
923 | |
872 | // avoid empty TXT rdata |
924 | // avoid completely empty TXT rdata |
873 | if (offs == rdlen_offs) |
925 | if (offs == rdlen_offs) |
874 | pkt[offs++] = 0; |
926 | pkt[offs++] = 0; |
|
|
927 | |
|
|
928 | slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ()); |
875 | } |
929 | } |
876 | else |
930 | else |
877 | { |
931 | { |
878 | // send RST |
932 | // send RST |
879 | pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3; |
933 | pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3; |
880 | pkt [offs++] = CMD_IP_RST; |
934 | pkt [offs++] = CMD_IP_RST; |
881 | } |
935 | } |
882 | |
936 | |
883 | int rdlen = offs - rdlen_offs; |
937 | int rdlen = offs - rdlen_offs; |
884 | |
938 | |
885 | pkt [rdlen_offs - 2] = rdlen >> 8; |
939 | pkt [rdlen_offs - 2] = rdlen >> 8; |
886 | pkt [rdlen_offs - 1] = rdlen; |
940 | pkt [rdlen_offs - 1] = rdlen; |
887 | |
941 | |
888 | if (dns) |
942 | if (dns) |
889 | { |
943 | { |
890 | // now update dns_rcv copy |
944 | // now update dns_rcv copy |
891 | rcv->pkt->len = offs; |
945 | rcv->pkt->len = offs; |
892 | memcpy (rcv->pkt->at (0), pkt.at (0), offs); |
946 | memcpy (rcv->pkt->at (0), pkt.at (0), offs); |
893 | } |
947 | } |
|
|
948 | } |
894 | |
949 | |
895 | duplicate_request: ; |
950 | duplicate_request: ; |
896 | } |
951 | } |
897 | else |
952 | else |
898 | pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR); |
953 | pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR); |
… | |
… | |
910 | pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class |
965 | pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class |
911 | pkt [offs++] = 0; pkt [offs++] = 0; |
966 | pkt [offs++] = 0; pkt [offs++] = 0; |
912 | pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL |
967 | pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL |
913 | pkt [offs++] = 0; pkt [offs++] = 4; // rdlength |
968 | pkt [offs++] = 0; pkt [offs++] = 4; // rdlength |
914 | |
969 | |
915 | slog (L_INFO, _("DNS tunnel: client %d tries to connect"), client); |
970 | slog (L_INFO, _("DNS: client %d connects"), client); |
916 | |
971 | |
917 | pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3; |
972 | pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3; |
918 | pkt [offs++] = CMD_IP_REJ; |
973 | pkt [offs++] = CMD_IP_REJ; |
919 | |
974 | |
920 | if (0 < client && client <= conns.size ()) |
975 | if (0 < client && client <= conns.size ()) |
… | |
… | |
957 | int seqno = (*i)->seqno; |
1012 | int seqno = (*i)->seqno; |
958 | u8 data[MAXSIZE], *datap = data; |
1013 | u8 data[MAXSIZE], *datap = data; |
959 | |
1014 | |
960 | if ((*i)->retry) |
1015 | if ((*i)->retry) |
961 | { |
1016 | { |
962 | dns->send_interval *= 1.001; |
1017 | dns->send_interval *= 1.01; |
963 | if (dns->send_interval > MAX_SEND_INTERVAL) |
1018 | if (dns->send_interval > MAX_SEND_INTERVAL) |
964 | dns->send_interval = MAX_SEND_INTERVAL; |
1019 | dns->send_interval = MAX_SEND_INTERVAL; |
965 | } |
1020 | } |
966 | else |
1021 | else |
967 | { |
1022 | { |
968 | #if 1 |
1023 | #if 0 |
969 | dns->send_interval *= 0.9999; |
1024 | dns->send_interval *= 0.999; |
970 | #endif |
1025 | #endif |
971 | if (dns->send_interval < MIN_SEND_INTERVAL) |
|
|
972 | dns->send_interval = MIN_SEND_INTERVAL; |
|
|
973 | |
|
|
974 | // the latency surely puts an upper bound on |
1026 | // the latency surely puts an upper bound on |
975 | // the minimum send interval |
1027 | // the minimum send interval |
976 | double latency = NOW - (*i)->sent; |
1028 | double latency = NOW - (*i)->sent; |
977 | |
1029 | |
978 | if (dns->send_interval > latency) |
1030 | if (latency < dns->min_latency) |
979 | dns->send_interval = latency; |
1031 | dns->min_latency = latency; |
|
|
1032 | |
|
|
1033 | if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor) |
|
|
1034 | dns->send_interval = dns->min_latency * conf.dns_overlap_factor; |
|
|
1035 | |
|
|
1036 | if (dns->send_interval < conf.dns_send_interval) |
|
|
1037 | dns->send_interval = conf.dns_send_interval; |
980 | } |
1038 | } |
981 | |
1039 | |
982 | delete *i; |
1040 | delete *i; |
983 | dns_sndpq.erase (i); |
1041 | dns_sndpq.erase (i); |
984 | |
1042 | |
… | |
… | |
1034 | |
1092 | |
1035 | if (ip [0] == CMD_IP_1 |
1093 | if (ip [0] == CMD_IP_1 |
1036 | && ip [1] == CMD_IP_2 |
1094 | && ip [1] == CMD_IP_2 |
1037 | && ip [2] == CMD_IP_3) |
1095 | && ip [2] == CMD_IP_3) |
1038 | { |
1096 | { |
1039 | slog (L_TRACE, _("got tunnel meta command %02x"), ip [3]); |
1097 | slog (L_TRACE, _("DNS: got tunnel meta command %02x"), ip [3]); |
1040 | |
1098 | |
1041 | if (ip [3] == CMD_IP_RST) |
1099 | if (ip [3] == CMD_IP_RST) |
1042 | { |
1100 | { |
1043 | slog (L_DEBUG, _("got tunnel RST request")); |
1101 | slog (L_DEBUG, _("DNS: got tunnel RST request")); |
1044 | |
1102 | |
1045 | delete dns; c->dns = 0; |
1103 | delete dns; c->dns = 0; |
1046 | |
1104 | |
1047 | return; |
1105 | return; |
1048 | } |
1106 | } |
1049 | else if (ip [3] == CMD_IP_SYN) |
1107 | else if (ip [3] == CMD_IP_SYN) |
1050 | { |
1108 | { |
1051 | slog (L_DEBUG, _("got tunnel SYN reply, server likes us.")); |
1109 | slog (L_DEBUG, _("DNS: got tunnel SYN reply, server likes us.")); |
1052 | dns->established = true; |
1110 | dns->established = true; |
1053 | } |
1111 | } |
1054 | else if (ip [3] == CMD_IP_REJ) |
1112 | else if (ip [3] == CMD_IP_REJ) |
1055 | { |
1113 | { |
1056 | slog (L_DEBUG, _("got tunnel REJ reply, server does not like us, aborting.")); |
1114 | slog (L_DEBUG, _("DNS: got tunnel REJ reply, server does not like us, aborting.")); |
1057 | abort (); |
1115 | abort (); |
1058 | } |
1116 | } |
1059 | else |
1117 | else |
1060 | slog (L_INFO, _("got unknown meta command %02x"), ip [3]); |
1118 | slog (L_INFO, _("DNS: got unknown meta command %02x"), ip [3]); |
1061 | } |
1119 | } |
1062 | else |
1120 | else |
1063 | slog (L_INFO, _("got spurious a record %d.%d.%d.%d"), |
1121 | slog (L_INFO, _("DNS: got spurious a record %d.%d.%d.%d"), |
1064 | ip [0], ip [1], ip [2], ip [3]); |
1122 | ip [0], ip [1], ip [2], ip [3]); |
1065 | |
1123 | |
1066 | return; |
1124 | return; |
1067 | } |
1125 | } |
1068 | |
1126 | |
1069 | int client, rseqno; |
1127 | int client, rseqno; |
1070 | decode_header (qname, client, rseqno); |
1128 | decode_header (qname, client, rseqno); |
1071 | |
1129 | |
1072 | if (client != THISNODE->id) |
1130 | if (client != THISNODE->id) |
1073 | { |
1131 | { |
1074 | slog (L_INFO, _("got dns tunnel response with wrong clientid, ignoring")); |
1132 | slog (L_INFO, _("DNS: got dns tunnel response with wrong clientid, ignoring")); |
1075 | datap = 0; |
1133 | datap = 0; |
1076 | } |
1134 | } |
1077 | else if (rseqno != seqno) |
1135 | else if (rseqno != seqno) |
1078 | { |
1136 | { |
1079 | slog (L_DEBUG, _("got dns tunnel response with wrong seqno, badly caching nameserver?")); |
1137 | slog (L_DEBUG, _("DNS: got dns tunnel response with wrong seqno, badly caching nameserver?")); |
1080 | datap = 0; |
1138 | datap = 0; |
1081 | } |
1139 | } |
1082 | } |
1140 | } |
1083 | } |
1141 | } |
1084 | |
1142 | |
… | |
… | |
1101 | |
1159 | |
1102 | pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len); |
1160 | pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len); |
1103 | |
1161 | |
1104 | if (pkt->len > 0) |
1162 | if (pkt->len > 0) |
1105 | { |
1163 | { |
1106 | if (THISNODE->dns_port) |
1164 | if (ntohs (pkt->flags) & FLAG_RESPONSE) |
|
|
1165 | dnsv4_client (*pkt); |
|
|
1166 | else |
1107 | { |
1167 | { |
1108 | dnsv4_server (*pkt); |
1168 | dnsv4_server (*pkt); |
1109 | sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len); |
1169 | sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len); |
1110 | } |
1170 | } |
1111 | else |
|
|
1112 | dnsv4_client (*pkt); |
|
|
1113 | |
1171 | |
1114 | delete pkt; |
1172 | delete pkt; |
1115 | } |
1173 | } |
1116 | } |
1174 | } |
1117 | } |
1175 | } |
1118 | |
1176 | |
1119 | bool |
1177 | bool |
1120 | connection::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) |
1178 | vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) |
1121 | { |
1179 | { |
|
|
1180 | int client = ntohl (si.host); |
|
|
1181 | |
|
|
1182 | assert (0 < client && client <= conns.size ()); |
|
|
1183 | |
|
|
1184 | connection *c = conns [client - 1]; |
|
|
1185 | |
1122 | if (!dns) |
1186 | if (!c->dns) |
1123 | dns = new dns_connection (this); |
1187 | c->dns = new dns_connection (c); |
1124 | |
1188 | |
1125 | if (!dns->snddq.put (pkt)) |
1189 | if (c->dns->snddq.put (pkt)) |
1126 | return false; |
|
|
1127 | |
|
|
1128 | dns->tw.trigger (); |
1190 | c->dns->tw.trigger (); |
1129 | |
1191 | |
|
|
1192 | // always return true even if the buffer overflows |
1130 | return true; |
1193 | return true; |
1131 | } |
1194 | } |
1132 | |
1195 | |
1133 | void |
1196 | void |
1134 | connection::dnsv4_reset_connection () |
1197 | connection::dnsv4_reset_connection () |
… | |
… | |
1160 | if (!send) |
1223 | if (!send) |
1161 | { |
1224 | { |
1162 | send = r; |
1225 | send = r; |
1163 | |
1226 | |
1164 | r->retry++; |
1227 | r->retry++; |
1165 | r->timeout = NOW + r->retry; |
1228 | r->timeout = NOW + (r->retry * min_latency * conf.dns_timeout_factor); |
|
|
1229 | |
|
|
1230 | // the following code changes the query section a bit, forcing |
|
|
1231 | // the forwarder to generate a new request |
|
|
1232 | if (r->stdhdr) |
|
|
1233 | { |
|
|
1234 | //printf ("reencoded header for ID %d retry %d:%d:%d (%p)\n", htons (r->pkt->id), THISNODE->id, r->seqno, r->retry); |
|
|
1235 | //encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry); |
|
|
1236 | } |
1166 | } |
1237 | } |
1167 | } |
1238 | } |
1168 | else |
1239 | else |
1169 | NEXT (r->timeout); |
1240 | NEXT (r->timeout); |
1170 | } |
1241 | } |
1171 | |
1242 | |
1172 | if (last_sent + send_interval <= NOW) |
|
|
1173 | { |
|
|
1174 | if (!send) |
1243 | if (!send) |
|
|
1244 | { |
|
|
1245 | // generate a new packet, if wise |
|
|
1246 | |
|
|
1247 | if (!established) |
1175 | { |
1248 | { |
1176 | // generate a new packet, if wise |
|
|
1177 | |
|
|
1178 | if (!established) |
|
|
1179 | { |
|
|
1180 | if (vpn->dns_sndpq.empty ()) |
1249 | if (vpn->dns_sndpq.empty ()) |
1181 | { |
|
|
1182 | send = new dns_snd (this); |
|
|
1183 | |
|
|
1184 | cfg.reset (THISNODE->id); |
|
|
1185 | send->gen_syn_req (cfg); |
|
|
1186 | } |
|
|
1187 | } |
|
|
1188 | else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING) |
|
|
1189 | { |
1250 | { |
1190 | send = new dns_snd (this); |
1251 | send = new dns_snd (this); |
|
|
1252 | |
|
|
1253 | cfg.reset (THISNODE->id); |
|
|
1254 | send->gen_syn_req (); |
|
|
1255 | } |
|
|
1256 | } |
|
|
1257 | else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding |
|
|
1258 | && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) |
|
|
1259 | { |
|
|
1260 | if (last_sent + send_interval <= NOW) |
|
|
1261 | { |
|
|
1262 | //printf ("sending data request etc.\n"); //D |
|
|
1263 | if (!snddq.empty () || last_received + 1. > NOW) |
|
|
1264 | { |
|
|
1265 | poll_interval = send_interval; |
|
|
1266 | NEXT (NOW + send_interval); |
|
|
1267 | } |
|
|
1268 | |
|
|
1269 | send = new dns_snd (this); |
1191 | send->gen_stream_req (sndseq, snddq); |
1270 | send->gen_stream_req (sndseq, snddq); |
|
|
1271 | send->timeout = NOW + min_latency * conf.dns_timeout_factor; |
1192 | |
1272 | |
1193 | sndseq = (sndseq + 1) & SEQNO_MASK; |
1273 | sndseq = (sndseq + 1) & SEQNO_MASK; |
1194 | } |
1274 | } |
1195 | |
1275 | else |
1196 | if (send) |
1276 | NEXT (last_sent + send_interval); |
1197 | vpn->dns_sndpq.push_back (send); |
|
|
1198 | } |
1277 | } |
1199 | |
1278 | |
1200 | if (send) |
1279 | if (send) |
1201 | { |
1280 | vpn->dns_sndpq.push_back (send); |
|
|
1281 | } |
|
|
1282 | |
|
|
1283 | if (send) |
|
|
1284 | { |
1202 | last_sent = NOW; |
1285 | last_sent = NOW; |
1203 | sendto (vpn->dnsv4_fd, |
1286 | sendto (vpn->dnsv4_fd, |
1204 | send->pkt->at (0), send->pkt->len, 0, |
1287 | send->pkt->at (0), send->pkt->len, 0, |
1205 | vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); |
1288 | vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); |
1206 | } |
|
|
1207 | } |
1289 | } |
1208 | else |
|
|
1209 | NEXT (last_sent + send_interval); |
|
|
1210 | |
1290 | |
1211 | slog (L_NOISE, "pi %f si %f N %f (%d:%d)", |
1291 | slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)", |
1212 | poll_interval, send_interval, next - NOW, |
1292 | poll_interval, send_interval, next - NOW, |
1213 | vpn->dns_sndpq.size (), snddq.size ()); |
1293 | vpn->dns_sndpq.size (), snddq.size (), |
|
|
1294 | rcvpq.size ()); |
1214 | |
1295 | |
1215 | // TODO: no idea when this happens, but when next < NOW, we have a problem |
1296 | // TODO: no idea when this happens, but when next < NOW, we have a problem |
|
|
1297 | // doesn't seem to happen anymore |
1216 | if (next < NOW + 0.0001) |
1298 | if (next < NOW + 0.001) |
1217 | next = NOW + 0.1; |
1299 | next = NOW + 0.1; |
1218 | |
1300 | |
1219 | w.start (next); |
1301 | w.start (next); |
1220 | } |
1302 | } |
1221 | |
1303 | |