… | |
… | |
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 has 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 | |
|
|
52 | #define TIMEOUT_FACTOR 2. |
51 | |
53 | |
52 | #define INITIAL_TIMEOUT 0.1 // retry timeouts |
54 | #define INITIAL_TIMEOUT 0.1 // retry timeouts |
53 | #define INITIAL_SYN_TIMEOUT 10. // retry timeout for initial syn |
55 | #define INITIAL_SYN_TIMEOUT 10. // retry timeout for initial syn |
54 | |
56 | |
55 | #define MIN_SEND_INTERVAL 0.01 // wait at least this time between sending requests |
57 | #define MIN_SEND_INTERVAL 0.001 // wait at least this time between sending requests |
56 | #define MAX_SEND_INTERVAL 0.5 // optimistic? |
58 | #define MAX_SEND_INTERVAL 2. // optimistic? |
57 | |
59 | |
|
|
60 | #define LATENCY_FACTOR 0.5 // RTT * LATENCY_FACTOR == sending rate |
58 | #define MAX_OUTSTANDING 10 // max. outstanding requests |
61 | #define MAX_OUTSTANDING 100 // max. outstanding requests |
59 | #define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog |
62 | #define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog |
60 | #define MAX_BACKLOG (100*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE |
63 | #define MAX_BACKLOG (32*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE |
61 | |
64 | |
62 | #define MAX_DOMAIN_SIZE 220 // 255 is legal limit, but bind doesn't compress well |
65 | #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 |
66 | // 240 leaves about 4 bytes of server reply data |
64 | // every two request bytes less give room for one reply byte |
67 | // every two request bytes less give room for one reply byte |
65 | |
68 | |
66 | #define SEQNO_MASK 0x3fff |
69 | #define SEQNO_MASK 0x0fff |
67 | #define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) ) |
70 | #define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) ) |
68 | |
71 | |
69 | #define MAX_LBL_SIZE 63 |
72 | #define MAX_LBL_SIZE 63 |
70 | #define MAX_PKT_SIZE 512 |
73 | #define MAX_PKT_SIZE 512 |
71 | |
74 | |
… | |
… | |
264 | static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO"); |
267 | static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO"); |
265 | |
268 | |
266 | ///////////////////////////////////////////////////////////////////////////// |
269 | ///////////////////////////////////////////////////////////////////////////// |
267 | |
270 | |
268 | #define HDRSIZE 6 |
271 | #define HDRSIZE 6 |
269 | |
272 | |
270 | inline void encode_header (char *data, int clientid, int seqno, int retry = 0) |
273 | inline void encode_header (char *data, int clientid, int seqno, int retry = 0) |
271 | { |
274 | { |
272 | seqno &= SEQNO_MASK; |
275 | seqno &= SEQNO_MASK; |
273 | |
276 | |
274 | u8 hdr[3] = { |
277 | u8 hdr[3] = { |
… | |
… | |
408 | struct dns_cfg |
411 | struct dns_cfg |
409 | { |
412 | { |
410 | static int next_uid; |
413 | static int next_uid; |
411 | |
414 | |
412 | u8 id1, id2, id3, id4; |
415 | u8 id1, id2, id3, id4; |
|
|
416 | |
413 | u8 version; |
417 | u8 version; |
|
|
418 | u8 flags; |
414 | u8 rrtype; |
419 | u8 rrtype; |
415 | u8 flags; |
|
|
416 | u8 def_ttl; |
420 | u8 def_ttl; |
417 | u8 rcv_cdc; |
421 | |
418 | u8 snd_cdc; |
|
|
419 | u16 max_size; |
|
|
420 | u16 client; |
422 | u16 client; |
421 | u16 uid; // to make request unique |
423 | u16 uid; // to make request unique |
422 | |
424 | |
423 | u8 reserved[8]; |
425 | u16 max_size; |
|
|
426 | u8 seq_cdc; |
|
|
427 | u8 req_cdc; |
|
|
428 | |
|
|
429 | u8 rep_cdc; |
|
|
430 | u8 delay; // time in 0.01s units that the server may delay replying packets |
|
|
431 | u8 r3, r4; |
|
|
432 | |
|
|
433 | u8 r5, r6, r7, r8; |
424 | |
434 | |
425 | void reset (int clientid); |
435 | void reset (int clientid); |
426 | bool valid (); |
436 | bool valid (); |
427 | }; |
437 | }; |
428 | |
438 | |
… | |
… | |
437 | |
447 | |
438 | version = 1; |
448 | version = 1; |
439 | |
449 | |
440 | rrtype = RR_TYPE_TXT; |
450 | rrtype = RR_TYPE_TXT; |
441 | flags = 0; |
451 | flags = 0; |
442 | def_ttl = 1; |
452 | def_ttl = 0; |
|
|
453 | seq_cdc = 26; |
|
|
454 | req_cdc = 62; |
443 | rcv_cdc = 0; |
455 | rep_cdc = 0; |
444 | snd_cdc = 62; |
|
|
445 | max_size = ntohs (MAX_PKT_SIZE); |
456 | max_size = htons (MAX_PKT_SIZE); |
446 | client = ntohs (clientid); |
457 | client = htons (clientid); |
447 | uid = next_uid++; |
458 | uid = next_uid++; |
|
|
459 | delay = 0; |
448 | |
460 | |
449 | memset (reserved, 0, 8); |
461 | r3 = r4 = 0; |
|
|
462 | r4 = r5 = r6 = r7 = 0; |
450 | } |
463 | } |
451 | |
464 | |
452 | bool dns_cfg::valid () |
465 | bool dns_cfg::valid () |
453 | { |
466 | { |
454 | return id1 == 'G' |
467 | return id1 == 'G' |
455 | && id2 == 'V' |
468 | && id2 == 'V' |
456 | && id3 == 'P' |
469 | && id3 == 'P' |
457 | && id4 == 'E' |
470 | && id4 == 'E' |
|
|
471 | && seq_cdc == 26 |
|
|
472 | && req_cdc == 62 |
|
|
473 | && rep_cdc == 0 |
458 | && version == 1 |
474 | && version == 1; |
459 | && flags == 0 |
|
|
460 | && rcv_cdc == 0 |
|
|
461 | && snd_cdc == 62 |
|
|
462 | && max_size == ntohs (MAX_PKT_SIZE); |
|
|
463 | } |
475 | } |
464 | |
476 | |
465 | struct dns_packet : net_packet |
477 | struct dns_packet : net_packet |
466 | { |
478 | { |
467 | u16 id; |
479 | u16 id; |
468 | u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4 |
480 | u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4 |
469 | u16 qdcount, ancount, nscount, arcount; |
481 | u16 qdcount, ancount, nscount, arcount; |
470 | |
482 | |
471 | u8 data[MAXSIZE - 6 * 2]; |
483 | u8 data [MAXSIZE - 6 * 2]; |
472 | |
484 | |
473 | int decode_label (char *data, int size, int &offs); |
485 | int decode_label (char *data, int size, int &offs); |
474 | }; |
486 | }; |
475 | |
487 | |
476 | int dns_packet::decode_label (char *data, int size, int &offs) |
488 | int dns_packet::decode_label (char *data, int size, int &offs) |
… | |
… | |
538 | |
550 | |
539 | bool established; |
551 | bool established; |
540 | |
552 | |
541 | tstamp last_received; |
553 | tstamp last_received; |
542 | tstamp last_sent; |
554 | tstamp last_sent; |
543 | double last_latency; |
555 | double min_latency; |
544 | double poll_interval, send_interval; |
556 | double poll_interval, send_interval; |
545 | |
557 | |
546 | vector<dns_rcv *> rcvpq; |
558 | vector<dns_rcv *> rcvpq; |
547 | |
559 | |
548 | byte_stream rcvdq; int rcvseq; |
560 | byte_stream rcvdq; int rcvseq; int repseq; |
549 | byte_stream snddq; int sndseq; |
561 | byte_stream snddq; int sndseq; |
550 | |
562 | |
551 | void time_cb (time_watcher &w); time_watcher tw; |
563 | void time_cb (time_watcher &w); time_watcher tw; |
552 | void receive_rep (dns_rcv *r); |
564 | void receive_rep (dns_rcv *r); |
553 | |
565 | |
… | |
… | |
622 | |
634 | |
623 | pkt->flags = htons (DEFAULT_CLIENT_FLAGS); |
635 | pkt->flags = htons (DEFAULT_CLIENT_FLAGS); |
624 | pkt->qdcount = htons (1); |
636 | pkt->qdcount = htons (1); |
625 | |
637 | |
626 | int offs = 6*2; |
638 | int offs = 6*2; |
627 | int dlen = MAX_DOMAIN_SIZE - (strlen (THISNODE->domain) + 2); |
639 | int dlen = MAX_DOMAIN_SIZE - (strlen (dns->c->conf->domain) + 2); |
628 | // MAX_DOMAIN_SIZE is technically 255, but bind doesn't compress responses well, |
640 | // MAX_DOMAIN_SIZE is technically 255, but bind doesn't compress responses well, |
629 | // so we need to have space for 2*MAX_DOMAIN_SIZE + header + extra |
641 | // so we need to have space for 2*MAX_DOMAIN_SIZE + header + extra |
630 | |
642 | |
631 | char enc[256], *encp = enc; |
643 | char enc[256], *encp = enc; |
632 | encode_header (enc, THISNODE->id, seqno); |
644 | encode_header (enc, THISNODE->id, seqno); |
… | |
… | |
650 | encp += lbllen; |
662 | encp += lbllen; |
651 | |
663 | |
652 | enclen -= lbllen; |
664 | enclen -= lbllen; |
653 | } |
665 | } |
654 | |
666 | |
655 | append_domain (*pkt, offs, THISNODE->domain); |
667 | append_domain (*pkt, offs, dns->c->conf->domain); |
656 | |
668 | |
657 | (*pkt)[offs++] = 0; |
669 | (*pkt)[offs++] = 0; |
658 | (*pkt)[offs++] = RR_TYPE_ANY >> 8; (*pkt)[offs++] = RR_TYPE_ANY; |
670 | (*pkt)[offs++] = RR_TYPE_ANY >> 8; (*pkt)[offs++] = RR_TYPE_ANY; |
659 | (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN; |
671 | (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN; |
660 | |
672 | |
… | |
… | |
663 | |
675 | |
664 | void dns_snd::gen_syn_req () |
676 | void dns_snd::gen_syn_req () |
665 | { |
677 | { |
666 | timeout = NOW + INITIAL_SYN_TIMEOUT; |
678 | timeout = NOW + INITIAL_SYN_TIMEOUT; |
667 | |
679 | |
668 | printf ("send syn\n");//D |
|
|
669 | |
|
|
670 | pkt->flags = htons (DEFAULT_CLIENT_FLAGS); |
680 | pkt->flags = htons (DEFAULT_CLIENT_FLAGS); |
671 | pkt->qdcount = htons (1); |
681 | pkt->qdcount = htons (1); |
672 | |
682 | |
673 | int offs = 6 * 2; |
683 | int offs = 6 * 2; |
674 | |
684 | |
… | |
… | |
676 | |
686 | |
677 | assert (elen <= MAX_LBL_SIZE); |
687 | assert (elen <= MAX_LBL_SIZE); |
678 | |
688 | |
679 | (*pkt)[offs] = elen; |
689 | (*pkt)[offs] = elen; |
680 | offs += elen + 1; |
690 | offs += elen + 1; |
681 | append_domain (*pkt, offs, THISNODE->domain); |
691 | append_domain (*pkt, offs, dns->c->conf->domain); |
682 | |
692 | |
683 | (*pkt)[offs++] = 0; |
693 | (*pkt)[offs++] = 0; |
684 | (*pkt)[offs++] = RR_TYPE_A >> 8; (*pkt)[offs++] = RR_TYPE_A; |
694 | (*pkt)[offs++] = RR_TYPE_A >> 8; (*pkt)[offs++] = RR_TYPE_A; |
685 | (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN; |
695 | (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN; |
686 | |
696 | |
… | |
… | |
712 | ///////////////////////////////////////////////////////////////////////////// |
722 | ///////////////////////////////////////////////////////////////////////////// |
713 | |
723 | |
714 | dns_connection::dns_connection (connection *c) |
724 | dns_connection::dns_connection (connection *c) |
715 | : c (c) |
725 | : c (c) |
716 | , rcvdq (MAX_BACKLOG * 2) |
726 | , rcvdq (MAX_BACKLOG * 2) |
717 | , snddq (MAX_BACKLOG * 2) |
727 | , snddq (MAX_BACKLOG) |
718 | , tw (this, &dns_connection::time_cb) |
728 | , tw (this, &dns_connection::time_cb) |
719 | { |
729 | { |
720 | vpn = c->vpn; |
730 | vpn = c->vpn; |
721 | |
731 | |
722 | established = false; |
732 | established = false; |
723 | |
733 | |
724 | rcvseq = sndseq = 0; |
734 | rcvseq = repseq = sndseq = 0; |
725 | |
735 | |
726 | last_sent = last_received = 0; |
736 | last_sent = last_received = 0; |
727 | poll_interval = MIN_POLL_INTERVAL; |
737 | poll_interval = 0.5; // starting here |
728 | send_interval = 0.5; // starting rate |
738 | send_interval = 0.5; // starting rate |
729 | last_latency = INITIAL_TIMEOUT; |
739 | min_latency = INITIAL_TIMEOUT; |
730 | } |
740 | } |
731 | |
741 | |
732 | dns_connection::~dns_connection () |
742 | dns_connection::~dns_connection () |
733 | { |
743 | { |
734 | for (vector<dns_rcv *>::iterator i = rcvpq.begin (); |
744 | for (vector<dns_rcv *>::iterator i = rcvpq.begin (); |
… | |
… | |
747 | poll_interval = send_interval; |
757 | poll_interval = send_interval; |
748 | } |
758 | } |
749 | else |
759 | else |
750 | { |
760 | { |
751 | poll_interval *= 1.5; |
761 | poll_interval *= 1.5; |
|
|
762 | |
752 | if (poll_interval > MAX_POLL_INTERVAL) |
763 | if (poll_interval > MAX_POLL_INTERVAL) |
753 | poll_interval = MAX_POLL_INTERVAL; |
764 | poll_interval = MAX_POLL_INTERVAL; |
754 | } |
765 | } |
755 | |
766 | |
756 | rcvpq.push_back (r); |
767 | rcvpq.push_back (r); |
… | |
… | |
806 | pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR); |
817 | pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR); |
807 | |
818 | |
808 | if (0 == (flags & (FLAG_RESPONSE | FLAG_OP_MASK)) |
819 | if (0 == (flags & (FLAG_RESPONSE | FLAG_OP_MASK)) |
809 | && pkt.qdcount == htons (1)) |
820 | && pkt.qdcount == htons (1)) |
810 | { |
821 | { |
811 | char qname[MAXSIZE]; |
822 | char qname [MAXSIZE]; |
812 | int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs); |
823 | int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs); |
813 | |
824 | |
814 | u16 qtype = pkt [offs++] << 8; qtype |= pkt [offs++]; |
825 | u16 qtype = pkt [offs++] << 8; qtype |= pkt [offs++]; |
815 | u16 qclass = pkt [offs++] << 8; qclass |= pkt [offs++]; |
826 | u16 qclass = pkt [offs++] << 8; qclass |= pkt [offs++]; |
816 | |
827 | |
… | |
… | |
823 | |
834 | |
824 | int dlen = strlen (THISNODE->domain); |
835 | int dlen = strlen (THISNODE->domain); |
825 | |
836 | |
826 | if (qclass == RR_CLASS_IN |
837 | if (qclass == RR_CLASS_IN |
827 | && qlen > dlen + 1 |
838 | && qlen > dlen + 1 |
828 | && !memcmp (qname + qlen - dlen - 1, THISNODE->domain, dlen)) |
839 | && !memcmp (qname + qlen - (dlen + 1), THISNODE->domain, dlen)) |
829 | { |
840 | { |
830 | // now generate reply |
841 | // now generate reply |
831 | pkt.ancount = htons (1); // one answer RR |
842 | pkt.ancount = htons (1); // one answer RR |
832 | pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_OK); |
843 | pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_OK); |
833 | |
844 | |
… | |
… | |
846 | if (0 < client && client <= conns.size ()) |
857 | if (0 < client && client <= conns.size ()) |
847 | { |
858 | { |
848 | connection *c = conns [client - 1]; |
859 | connection *c = conns [client - 1]; |
849 | dns_connection *dns = c->dns; |
860 | dns_connection *dns = c->dns; |
850 | dns_rcv *rcv; |
861 | dns_rcv *rcv; |
851 | bool in_seq; |
|
|
852 | |
862 | |
853 | if (dns) |
863 | if (dns) |
854 | { |
864 | { |
855 | for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); ) |
865 | for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); ) |
856 | if (SEQNO_EQ ((*i)->seqno, seqno)) |
866 | if (SEQNO_EQ ((*i)->seqno, seqno)) |
… | |
… | |
867 | memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len); |
877 | memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len); |
868 | |
878 | |
869 | goto duplicate_request; |
879 | goto duplicate_request; |
870 | } |
880 | } |
871 | |
881 | |
872 | in_seq = dns->rcvseq == seqno; |
|
|
873 | |
|
|
874 | // new packet, queue |
882 | // new packet, queue |
875 | rcv = new dns_rcv (seqno, data, datalen); |
883 | rcv = new dns_rcv (seqno, data, datalen); |
876 | dns->receive_rep (rcv); |
884 | dns->receive_rep (rcv); |
877 | } |
885 | } |
878 | |
886 | |
|
|
887 | { |
879 | pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section |
888 | pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section |
880 | |
889 | |
881 | int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A; |
890 | int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A; |
882 | pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type |
891 | pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type |
883 | pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class |
892 | pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class |
884 | pkt [offs++] = 0; pkt [offs++] = 0; |
893 | pkt [offs++] = 0; pkt [offs++] = 0; |
885 | pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL |
894 | pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL |
886 | |
895 | |
887 | int rdlen_offs = offs += 2; |
896 | int rdlen_offs = offs += 2; |
888 | |
897 | |
|
|
898 | if (dns) |
|
|
899 | { |
889 | int dlen = (dns ? ntohs (dns->cfg.max_size) : MAX_PKT_SIZE) - offs; |
900 | int dlen = ntohs (dns->cfg.max_size) - offs; |
|
|
901 | |
890 | // bind doesn't compress well, so reduce further by one label length |
902 | // bind doesn't compress well, so reduce further by one label length |
891 | dlen -= qlen; |
903 | dlen -= qlen; |
892 | |
904 | |
893 | if (dns) |
|
|
894 | { |
|
|
895 | // only put data into in-order sequence packets, if |
905 | // only put data into in-order sequence packets, if |
896 | // we receive out-of-order packets we generate empty |
906 | // we receive out-of-order packets we generate empty |
897 | // replies |
907 | // replies |
898 | while (dlen > 1 && !dns->snddq.empty () && in_seq) |
908 | //printf ("%d - %d & %x (=%d) < %d\n", seqno, dns->repseq, SEQNO_MASK, (seqno - dns->repseq) & SEQNO_MASK, MAX_WINDOW);//D |
|
|
909 | if (((seqno - dns->repseq) & SEQNO_MASK) <= MAX_WINDOW) |
899 | { |
910 | { |
|
|
911 | dns->repseq = seqno; |
|
|
912 | |
|
|
913 | while (dlen > 1 && !dns->snddq.empty ()) |
|
|
914 | { |
900 | int txtlen = dlen <= 255 ? dlen - 1 : 255; |
915 | int txtlen = dlen <= 255 ? dlen - 1 : 255; |
901 | |
916 | |
902 | if (txtlen > dns->snddq.size ()) |
917 | if (txtlen > dns->snddq.size ()) |
903 | txtlen = dns->snddq.size (); |
918 | txtlen = dns->snddq.size (); |
904 | |
919 | |
905 | pkt[offs++] = txtlen; |
920 | pkt[offs++] = txtlen; |
906 | memcpy (pkt.at (offs), dns->snddq.begin (), txtlen); |
921 | memcpy (pkt.at (offs), dns->snddq.begin (), txtlen); |
907 | offs += txtlen; |
922 | offs += txtlen; |
908 | dns->snddq.remove (txtlen); |
923 | dns->snddq.remove (txtlen); |
909 | |
924 | |
910 | dlen -= txtlen + 1; |
925 | dlen -= txtlen + 1; |
|
|
926 | } |
911 | } |
927 | } |
912 | |
928 | |
913 | // avoid empty TXT rdata |
929 | // avoid completely empty TXT rdata |
914 | if (offs == rdlen_offs) |
930 | if (offs == rdlen_offs) |
915 | pkt[offs++] = 0; |
931 | pkt[offs++] = 0; |
916 | |
932 | |
917 | slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ()); |
933 | slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ()); |
918 | } |
934 | } |
919 | else |
935 | else |
920 | { |
936 | { |
921 | // send RST |
937 | // send RST |
922 | pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3; |
938 | pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3; |
923 | pkt [offs++] = CMD_IP_RST; |
939 | pkt [offs++] = CMD_IP_RST; |
924 | } |
940 | } |
925 | |
941 | |
926 | int rdlen = offs - rdlen_offs; |
942 | int rdlen = offs - rdlen_offs; |
927 | |
943 | |
928 | pkt [rdlen_offs - 2] = rdlen >> 8; |
944 | pkt [rdlen_offs - 2] = rdlen >> 8; |
929 | pkt [rdlen_offs - 1] = rdlen; |
945 | pkt [rdlen_offs - 1] = rdlen; |
930 | |
946 | |
931 | if (dns) |
947 | if (dns) |
932 | { |
948 | { |
933 | // now update dns_rcv copy |
949 | // now update dns_rcv copy |
934 | rcv->pkt->len = offs; |
950 | rcv->pkt->len = offs; |
935 | memcpy (rcv->pkt->at (0), pkt.at (0), offs); |
951 | memcpy (rcv->pkt->at (0), pkt.at (0), offs); |
936 | } |
952 | } |
|
|
953 | } |
937 | |
954 | |
938 | duplicate_request: ; |
955 | duplicate_request: ; |
939 | } |
956 | } |
940 | else |
957 | else |
941 | pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR); |
958 | pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR); |
… | |
… | |
953 | pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class |
970 | pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class |
954 | pkt [offs++] = 0; pkt [offs++] = 0; |
971 | pkt [offs++] = 0; pkt [offs++] = 0; |
955 | pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL |
972 | pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL |
956 | pkt [offs++] = 0; pkt [offs++] = 4; // rdlength |
973 | pkt [offs++] = 0; pkt [offs++] = 4; // rdlength |
957 | |
974 | |
958 | slog (L_INFO, _("DNS: client %d tries to connect"), client); |
975 | slog (L_INFO, _("DNS: client %d connects"), client); |
959 | |
976 | |
960 | pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3; |
977 | pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3; |
961 | pkt [offs++] = CMD_IP_REJ; |
978 | pkt [offs++] = CMD_IP_REJ; |
962 | |
979 | |
963 | if (0 < client && client <= conns.size ()) |
980 | if (0 < client && client <= conns.size ()) |
… | |
… | |
1006 | if (dns->send_interval > MAX_SEND_INTERVAL) |
1023 | if (dns->send_interval > MAX_SEND_INTERVAL) |
1007 | dns->send_interval = MAX_SEND_INTERVAL; |
1024 | dns->send_interval = MAX_SEND_INTERVAL; |
1008 | } |
1025 | } |
1009 | else |
1026 | else |
1010 | { |
1027 | { |
1011 | #if 1 |
1028 | #if 0 |
1012 | dns->send_interval *= 0.999; |
1029 | dns->send_interval *= 0.999; |
1013 | #endif |
1030 | #endif |
1014 | if (dns->send_interval < MIN_SEND_INTERVAL) |
|
|
1015 | dns->send_interval = MIN_SEND_INTERVAL; |
|
|
1016 | |
|
|
1017 | // the latency surely puts an upper bound on |
1031 | // the latency surely puts an upper bound on |
1018 | // the minimum send interval |
1032 | // the minimum send interval |
1019 | double latency = NOW - (*i)->sent; |
1033 | double latency = NOW - (*i)->sent; |
|
|
1034 | |
|
|
1035 | if (latency < dns->min_latency) |
1020 | dns->last_latency = latency; |
1036 | dns->min_latency = latency; |
1021 | |
1037 | |
1022 | if (dns->send_interval > latency) |
1038 | if (dns->send_interval > dns->min_latency * LATENCY_FACTOR) |
1023 | dns->send_interval = latency; |
1039 | dns->send_interval = dns->min_latency * LATENCY_FACTOR; |
|
|
1040 | |
|
|
1041 | if (dns->send_interval < MIN_SEND_INTERVAL) |
|
|
1042 | dns->send_interval = MIN_SEND_INTERVAL; |
1024 | } |
1043 | } |
1025 | |
1044 | |
1026 | delete *i; |
1045 | delete *i; |
1027 | dns_sndpq.erase (i); |
1046 | dns_sndpq.erase (i); |
1028 | |
1047 | |
… | |
… | |
1145 | |
1164 | |
1146 | pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len); |
1165 | pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len); |
1147 | |
1166 | |
1148 | if (pkt->len > 0) |
1167 | if (pkt->len > 0) |
1149 | { |
1168 | { |
1150 | if (THISNODE->dns_port) |
1169 | if (ntohs (pkt->flags) & FLAG_RESPONSE) |
|
|
1170 | dnsv4_client (*pkt); |
|
|
1171 | else |
1151 | { |
1172 | { |
1152 | dnsv4_server (*pkt); |
1173 | dnsv4_server (*pkt); |
1153 | sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len); |
1174 | sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len); |
1154 | } |
1175 | } |
1155 | else |
|
|
1156 | dnsv4_client (*pkt); |
|
|
1157 | |
1176 | |
1158 | delete pkt; |
1177 | delete pkt; |
1159 | } |
1178 | } |
1160 | } |
1179 | } |
1161 | } |
1180 | } |
… | |
… | |
1170 | connection *c = conns [client - 1]; |
1189 | connection *c = conns [client - 1]; |
1171 | |
1190 | |
1172 | if (!c->dns) |
1191 | if (!c->dns) |
1173 | c->dns = new dns_connection (c); |
1192 | c->dns = new dns_connection (c); |
1174 | |
1193 | |
1175 | if (!c->dns->snddq.put (pkt)) |
1194 | if (c->dns->snddq.put (pkt)) |
1176 | return false; |
|
|
1177 | |
|
|
1178 | c->dns->tw.trigger (); |
1195 | c->dns->tw.trigger (); |
1179 | |
1196 | |
|
|
1197 | // always return true even if the buffer overflows |
1180 | return true; |
1198 | return true; |
1181 | } |
1199 | } |
1182 | |
1200 | |
1183 | void |
1201 | void |
1184 | connection::dnsv4_reset_connection () |
1202 | connection::dnsv4_reset_connection () |
… | |
… | |
1210 | if (!send) |
1228 | if (!send) |
1211 | { |
1229 | { |
1212 | send = r; |
1230 | send = r; |
1213 | |
1231 | |
1214 | r->retry++; |
1232 | r->retry++; |
1215 | r->timeout = NOW + (r->retry * last_latency * 8.); |
1233 | r->timeout = NOW + (r->retry * min_latency * TIMEOUT_FACTOR); |
1216 | |
1234 | |
1217 | // the following code changes the query section a bit, forcing |
1235 | // the following code changes the query section a bit, forcing |
1218 | // the forwarder to generate a new request |
1236 | // the forwarder to generate a new request |
1219 | if (r->stdhdr) |
1237 | if (r->stdhdr) |
1220 | { |
1238 | { |
1221 | //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); |
1239 | //printf ("reencoded header for ID %d retry %d:%d:%d (%p)\n", htons (r->pkt->id), THISNODE->id, r->seqno, r->retry); |
1222 | //encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry); |
1240 | //encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry); |
1223 | } |
1241 | } |
1224 | } |
1242 | } |
1225 | } |
1243 | } |
1226 | else |
1244 | else |
1227 | NEXT (r->timeout); |
1245 | NEXT (r->timeout); |
1228 | } |
1246 | } |
1229 | |
1247 | |
1230 | if (last_sent + send_interval <= NOW) |
|
|
1231 | { |
|
|
1232 | if (!send) |
1248 | if (!send) |
|
|
1249 | { |
|
|
1250 | // generate a new packet, if wise |
|
|
1251 | |
|
|
1252 | if (!established) |
1233 | { |
1253 | { |
1234 | // generate a new packet, if wise |
1254 | if (vpn->dns_sndpq.empty ()) |
1235 | |
|
|
1236 | if (!established) |
|
|
1237 | { |
1255 | { |
1238 | if (vpn->dns_sndpq.empty ()) |
|
|
1239 | { |
|
|
1240 | send = new dns_snd (this); |
1256 | send = new dns_snd (this); |
1241 | |
1257 | |
1242 | printf ("new conn %p %d\n", this, c->conf->id);//D |
|
|
1243 | cfg.reset (THISNODE->id); |
1258 | cfg.reset (THISNODE->id); |
1244 | send->gen_syn_req (); |
1259 | send->gen_syn_req (); |
1245 | } |
|
|
1246 | } |
1260 | } |
|
|
1261 | } |
1247 | else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING |
1262 | else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING |
1248 | && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) |
1263 | && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) |
|
|
1264 | { |
|
|
1265 | if (last_sent + send_interval <= NOW) |
1249 | { |
1266 | { |
1250 | //printf ("sending data request etc.\n"); //D |
1267 | //printf ("sending data request etc.\n"); //D |
1251 | if (!snddq.empty ()) |
1268 | if (!snddq.empty () || last_received + 1. > NOW) |
1252 | { |
1269 | { |
1253 | poll_interval = send_interval; |
1270 | poll_interval = send_interval; |
1254 | NEXT (NOW + send_interval); |
1271 | NEXT (NOW + send_interval); |
1255 | } |
1272 | } |
1256 | |
1273 | |
1257 | send = new dns_snd (this); |
1274 | send = new dns_snd (this); |
1258 | send->gen_stream_req (sndseq, snddq); |
1275 | send->gen_stream_req (sndseq, snddq); |
1259 | send->timeout = NOW + last_latency * 8.; |
1276 | send->timeout = NOW + min_latency * TIMEOUT_FACTOR; |
1260 | |
1277 | |
1261 | sndseq = (sndseq + 1) & SEQNO_MASK; |
1278 | sndseq = (sndseq + 1) & SEQNO_MASK; |
1262 | } |
1279 | } |
1263 | |
1280 | else |
1264 | if (send) |
1281 | NEXT (last_sent + send_interval); |
1265 | vpn->dns_sndpq.push_back (send); |
|
|
1266 | } |
1282 | } |
1267 | |
1283 | |
1268 | if (send) |
1284 | if (send) |
1269 | { |
1285 | vpn->dns_sndpq.push_back (send); |
|
|
1286 | } |
|
|
1287 | |
|
|
1288 | if (send) |
|
|
1289 | { |
1270 | last_sent = NOW; |
1290 | last_sent = NOW; |
|
|
1291 | if (rand () & 15 != 0)//D |
1271 | sendto (vpn->dnsv4_fd, |
1292 | sendto (vpn->dnsv4_fd, |
1272 | send->pkt->at (0), send->pkt->len, 0, |
1293 | send->pkt->at (0), send->pkt->len, 0, |
1273 | vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); |
1294 | vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); |
1274 | } |
|
|
1275 | } |
1295 | } |
1276 | else |
|
|
1277 | NEXT (last_sent + send_interval); |
|
|
1278 | |
1296 | |
1279 | slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d)", |
1297 | slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)", |
1280 | poll_interval, send_interval, next - NOW, |
1298 | poll_interval, send_interval, next - NOW, |
1281 | vpn->dns_sndpq.size (), snddq.size ()); |
1299 | vpn->dns_sndpq.size (), snddq.size (), |
|
|
1300 | rcvpq.size ()); |
1282 | |
1301 | |
1283 | // TODO: no idea when this happens, but when next < NOW, we have a problem |
1302 | // TODO: no idea when this happens, but when next < NOW, we have a problem |
1284 | if (next < NOW + 0.0001) |
1303 | if (next < NOW + 0.001) |
1285 | next = NOW + 0.1; |
1304 | next = NOW + 0.1; |
1286 | |
1305 | |
1287 | w.start (next); |
1306 | w.start (next); |
1288 | } |
1307 | } |
1289 | |
1308 | |