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 | |
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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 |
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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 |
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59 | #define MAX_OUTSTANDING 2 // max. outstanding requests |
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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 |
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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 |
… | |
… | |
460 | r4 = r5 = r6 = r7 = 0; |
473 | r4 = r5 = r6 = r7 = 0; |
461 | } |
474 | } |
462 | |
475 | |
463 | bool dns_cfg::valid () |
476 | bool dns_cfg::valid () |
464 | { |
477 | { |
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478 | // although the protocol itself allows for some configurability, |
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479 | // only the following encoding/decoding settings are implemented. |
465 | return id1 == 'G' |
480 | return id1 == 'G' |
466 | && id2 == 'V' |
481 | && id2 == 'V' |
467 | && id3 == 'P' |
482 | && id3 == 'P' |
468 | && id4 == 'E' |
483 | && id4 == 'E' |
469 | && seq_cdc == 26 |
484 | && seq_cdc == 26 |
… | |
… | |
553 | double min_latency; |
568 | double min_latency; |
554 | double poll_interval, send_interval; |
569 | double poll_interval, send_interval; |
555 | |
570 | |
556 | vector<dns_rcv *> rcvpq; |
571 | vector<dns_rcv *> rcvpq; |
557 | |
572 | |
558 | byte_stream rcvdq; int rcvseq; |
573 | byte_stream rcvdq; int rcvseq; int repseq; |
559 | byte_stream snddq; int sndseq; |
574 | byte_stream snddq; int sndseq; |
560 | |
575 | |
561 | void time_cb (time_watcher &w); time_watcher tw; |
576 | inline void time_cb (ev::timer &w, int revents); ev::timer tw; |
562 | void receive_rep (dns_rcv *r); |
577 | void receive_rep (dns_rcv *r); |
563 | |
578 | |
564 | dns_connection (connection *c); |
579 | dns_connection (connection *c); |
565 | ~dns_connection (); |
580 | ~dns_connection (); |
566 | }; |
581 | }; |
… | |
… | |
585 | : dns (dns) |
600 | : dns (dns) |
586 | { |
601 | { |
587 | timeout = 0; |
602 | timeout = 0; |
588 | retry = 0; |
603 | retry = 0; |
589 | seqno = 0; |
604 | seqno = 0; |
590 | sent = NOW; |
605 | sent = ev_now (); |
591 | stdhdr = false; |
606 | stdhdr = false; |
592 | |
607 | |
593 | pkt = new dns_packet; |
608 | pkt = new dns_packet; |
594 | |
609 | |
595 | pkt->id = next_id (); |
610 | pkt->id = next_id (); |
… | |
… | |
626 | void dns_snd::gen_stream_req (int seqno, byte_stream &stream) |
641 | void dns_snd::gen_stream_req (int seqno, byte_stream &stream) |
627 | { |
642 | { |
628 | stdhdr = true; |
643 | stdhdr = true; |
629 | this->seqno = seqno; |
644 | this->seqno = seqno; |
630 | |
645 | |
631 | timeout = NOW + INITIAL_TIMEOUT; |
646 | timeout = ev_now () + INITIAL_TIMEOUT; |
632 | |
647 | |
633 | pkt->flags = htons (DEFAULT_CLIENT_FLAGS); |
648 | pkt->flags = htons (DEFAULT_CLIENT_FLAGS); |
634 | pkt->qdcount = htons (1); |
649 | pkt->qdcount = htons (1); |
635 | |
650 | |
636 | int offs = 6*2; |
651 | int offs = 6*2; |
… | |
… | |
671 | pkt->len = offs; |
686 | pkt->len = offs; |
672 | } |
687 | } |
673 | |
688 | |
674 | void dns_snd::gen_syn_req () |
689 | void dns_snd::gen_syn_req () |
675 | { |
690 | { |
676 | timeout = NOW + INITIAL_SYN_TIMEOUT; |
691 | timeout = ev_now () + INITIAL_SYN_TIMEOUT; |
677 | |
692 | |
678 | pkt->flags = htons (DEFAULT_CLIENT_FLAGS); |
693 | pkt->flags = htons (DEFAULT_CLIENT_FLAGS); |
679 | pkt->qdcount = htons (1); |
694 | pkt->qdcount = htons (1); |
680 | |
695 | |
681 | int offs = 6 * 2; |
696 | int offs = 6 * 2; |
… | |
… | |
720 | ///////////////////////////////////////////////////////////////////////////// |
735 | ///////////////////////////////////////////////////////////////////////////// |
721 | |
736 | |
722 | dns_connection::dns_connection (connection *c) |
737 | dns_connection::dns_connection (connection *c) |
723 | : c (c) |
738 | : c (c) |
724 | , rcvdq (MAX_BACKLOG * 2) |
739 | , rcvdq (MAX_BACKLOG * 2) |
725 | , snddq (MAX_BACKLOG * 2) |
740 | , snddq (MAX_BACKLOG) |
726 | , tw (this, &dns_connection::time_cb) |
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727 | { |
741 | { |
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742 | tw.set<dns_connection, &dns_connection::time_cb> (this); |
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743 | |
728 | vpn = c->vpn; |
744 | vpn = c->vpn; |
729 | |
745 | |
730 | established = false; |
746 | established = false; |
731 | |
747 | |
732 | rcvseq = sndseq = 0; |
748 | rcvseq = repseq = sndseq = 0; |
733 | |
749 | |
734 | last_sent = last_received = 0; |
750 | last_sent = last_received = 0; |
735 | poll_interval = 0.5; // starting here |
751 | poll_interval = 0.5; // starting here |
736 | send_interval = 0.5; // starting rate |
752 | send_interval = 0.5; // starting rate |
737 | min_latency = INITIAL_TIMEOUT; |
753 | min_latency = INITIAL_TIMEOUT; |
… | |
… | |
747 | |
763 | |
748 | void dns_connection::receive_rep (dns_rcv *r) |
764 | void dns_connection::receive_rep (dns_rcv *r) |
749 | { |
765 | { |
750 | if (r->datalen) |
766 | if (r->datalen) |
751 | { |
767 | { |
752 | last_received = NOW; |
768 | last_received = ev_now (); |
753 | tw.trigger (); |
769 | tw (); |
754 | |
770 | |
755 | poll_interval = send_interval; |
771 | poll_interval = send_interval; |
756 | } |
772 | } |
757 | else |
773 | else |
758 | { |
774 | { |
… | |
… | |
768 | |
784 | |
769 | // find next packet |
785 | // find next packet |
770 | for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); ) |
786 | for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); ) |
771 | if (SEQNO_EQ (rcvseq, (*i)->seqno)) |
787 | if (SEQNO_EQ (rcvseq, (*i)->seqno)) |
772 | { |
788 | { |
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789 | //printf ("seqno eq %x %x\n", rcvseq, (*i)->seqno);//D |
773 | // enter the packet into our input stream |
790 | // enter the packet into our input stream |
774 | r = *i; |
791 | r = *i; |
775 | |
792 | |
776 | // remove the oldest packet, look forward, as it's oldest first |
793 | // remove the oldest packet, look forward, as it's oldest first |
777 | for (vector<dns_rcv *>::iterator j = rcvpq.begin (); j != rcvpq.end (); ++j) |
794 | for (vector<dns_rcv *>::iterator j = rcvpq.begin (); j != rcvpq.end (); ++j) |
778 | if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW)) |
795 | if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW)) |
779 | { |
796 | { |
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797 | //printf ("seqno RR %x %x\n", (*j)->seqno, rcvseq - MAX_WINDOW);//D |
780 | delete *j; |
798 | delete *j; |
781 | rcvpq.erase (j); |
799 | rcvpq.erase (j); |
782 | break; |
800 | break; |
783 | } |
801 | } |
784 | |
802 | |
… | |
… | |
791 | } |
809 | } |
792 | |
810 | |
793 | while (vpn_packet *pkt = rcvdq.get ()) |
811 | while (vpn_packet *pkt = rcvdq.get ()) |
794 | { |
812 | { |
795 | sockinfo si; |
813 | sockinfo si; |
796 | si.host = 0x01010101; si.port = htons (c->conf->id); si.prot = PROT_DNSv4; |
814 | si.host = htonl (c->conf->id); si.port = 0; si.prot = PROT_DNSv4; |
797 | |
815 | |
798 | vpn->recv_vpn_packet (pkt, si); |
816 | vpn->recv_vpn_packet (pkt, si); |
799 | |
817 | |
800 | delete pkt; |
818 | delete pkt; |
801 | } |
819 | } |
… | |
… | |
855 | if (0 < client && client <= conns.size ()) |
873 | if (0 < client && client <= conns.size ()) |
856 | { |
874 | { |
857 | connection *c = conns [client - 1]; |
875 | connection *c = conns [client - 1]; |
858 | dns_connection *dns = c->dns; |
876 | dns_connection *dns = c->dns; |
859 | dns_rcv *rcv; |
877 | dns_rcv *rcv; |
860 | bool in_seq; |
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861 | |
878 | |
862 | if (dns) |
879 | if (dns) |
863 | { |
880 | { |
864 | for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); ) |
881 | for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); ) |
865 | if (SEQNO_EQ ((*i)->seqno, seqno)) |
882 | if (SEQNO_EQ ((*i)->seqno, seqno)) |
… | |
… | |
876 | memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len); |
893 | memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len); |
877 | |
894 | |
878 | goto duplicate_request; |
895 | goto duplicate_request; |
879 | } |
896 | } |
880 | |
897 | |
881 | in_seq = dns->rcvseq == seqno; |
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882 | |
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883 | // new packet, queue |
898 | // new packet, queue |
884 | rcv = new dns_rcv (seqno, data, datalen); |
899 | rcv = new dns_rcv (seqno, data, datalen); |
885 | dns->receive_rep (rcv); |
900 | dns->receive_rep (rcv); |
886 | } |
901 | } |
887 | |
902 | |
… | |
… | |
904 | dlen -= qlen; |
919 | dlen -= qlen; |
905 | |
920 | |
906 | // only put data into in-order sequence packets, if |
921 | // only put data into in-order sequence packets, if |
907 | // we receive out-of-order packets we generate empty |
922 | // we receive out-of-order packets we generate empty |
908 | // replies |
923 | // replies |
909 | while (dlen > 1 && !dns->snddq.empty () && in_seq) |
924 | //printf ("%d - %d & %x (=%d) < %d\n", seqno, dns->repseq, SEQNO_MASK, (seqno - dns->repseq) & SEQNO_MASK, MAX_WINDOW);//D |
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925 | if (((seqno - dns->repseq) & SEQNO_MASK) <= MAX_WINDOW) |
910 | { |
926 | { |
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927 | dns->repseq = seqno; |
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928 | |
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929 | while (dlen > 1 && !dns->snddq.empty ()) |
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930 | { |
911 | int txtlen = dlen <= 255 ? dlen - 1 : 255; |
931 | int txtlen = dlen <= 255 ? dlen - 1 : 255; |
912 | |
932 | |
913 | if (txtlen > dns->snddq.size ()) |
933 | if (txtlen > dns->snddq.size ()) |
914 | txtlen = dns->snddq.size (); |
934 | txtlen = dns->snddq.size (); |
915 | |
935 | |
916 | pkt[offs++] = txtlen; |
936 | pkt[offs++] = txtlen; |
917 | memcpy (pkt.at (offs), dns->snddq.begin (), txtlen); |
937 | memcpy (pkt.at (offs), dns->snddq.begin (), txtlen); |
918 | offs += txtlen; |
938 | offs += txtlen; |
919 | dns->snddq.remove (txtlen); |
939 | dns->snddq.remove (txtlen); |
920 | |
940 | |
921 | dlen -= txtlen + 1; |
941 | dlen -= txtlen + 1; |
|
|
942 | } |
922 | } |
943 | } |
923 | |
944 | |
924 | // avoid empty TXT rdata |
945 | // avoid completely empty TXT rdata |
925 | if (offs == rdlen_offs) |
946 | if (offs == rdlen_offs) |
926 | pkt[offs++] = 0; |
947 | pkt[offs++] = 0; |
927 | |
948 | |
928 | slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ()); |
949 | slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ()); |
929 | } |
950 | } |
… | |
… | |
1009 | { |
1030 | { |
1010 | dns_connection *dns = (*i)->dns; |
1031 | dns_connection *dns = (*i)->dns; |
1011 | connection *c = dns->c; |
1032 | connection *c = dns->c; |
1012 | int seqno = (*i)->seqno; |
1033 | int seqno = (*i)->seqno; |
1013 | u8 data[MAXSIZE], *datap = data; |
1034 | u8 data[MAXSIZE], *datap = data; |
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1035 | //printf ("rcv pkt %x\n", seqno);//D |
1014 | |
1036 | |
1015 | if ((*i)->retry) |
1037 | if ((*i)->retry) |
1016 | { |
1038 | { |
1017 | dns->send_interval *= 1.01; |
1039 | dns->send_interval *= 1.01; |
1018 | if (dns->send_interval > MAX_SEND_INTERVAL) |
1040 | if (dns->send_interval > MAX_SEND_INTERVAL) |
… | |
… | |
1023 | #if 0 |
1045 | #if 0 |
1024 | dns->send_interval *= 0.999; |
1046 | dns->send_interval *= 0.999; |
1025 | #endif |
1047 | #endif |
1026 | // the latency surely puts an upper bound on |
1048 | // the latency surely puts an upper bound on |
1027 | // the minimum send interval |
1049 | // the minimum send interval |
1028 | double latency = NOW - (*i)->sent; |
1050 | double latency = ev_now () - (*i)->sent; |
1029 | |
1051 | |
1030 | if (latency < dns->min_latency) |
1052 | if (latency < dns->min_latency) |
1031 | dns->min_latency = latency; |
1053 | dns->min_latency = latency; |
1032 | |
1054 | |
1033 | if (dns->send_interval > dns->min_latency * LATENCY_FACTOR) |
1055 | if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor) |
1034 | dns->send_interval = dns->min_latency * LATENCY_FACTOR; |
1056 | dns->send_interval = dns->min_latency * conf.dns_overlap_factor; |
1035 | |
1057 | |
1036 | if (dns->send_interval < MIN_SEND_INTERVAL) |
1058 | if (dns->send_interval < conf.dns_send_interval) |
1037 | dns->send_interval = MIN_SEND_INTERVAL; |
1059 | dns->send_interval = conf.dns_send_interval; |
1038 | } |
1060 | } |
1039 | |
1061 | |
1040 | delete *i; |
1062 | delete *i; |
1041 | dns_sndpq.erase (i); |
1063 | dns_sndpq.erase (i); |
1042 | |
1064 | |
… | |
… | |
1147 | break; |
1169 | break; |
1148 | } |
1170 | } |
1149 | } |
1171 | } |
1150 | |
1172 | |
1151 | void |
1173 | void |
1152 | vpn::dnsv4_ev (io_watcher &w, short revents) |
1174 | vpn::dnsv4_ev (ev::io &w, int revents) |
1153 | { |
1175 | { |
1154 | if (revents & EVENT_READ) |
1176 | if (revents & EV_READ) |
1155 | { |
1177 | { |
1156 | dns_packet *pkt = new dns_packet; |
1178 | dns_packet *pkt = new dns_packet; |
1157 | struct sockaddr_in sa; |
1179 | struct sockaddr_in sa; |
1158 | socklen_t sa_len = sizeof (sa); |
1180 | socklen_t sa_len = sizeof (sa); |
1159 | |
1181 | |
… | |
… | |
1175 | } |
1197 | } |
1176 | |
1198 | |
1177 | bool |
1199 | bool |
1178 | vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) |
1200 | vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) |
1179 | { |
1201 | { |
1180 | int client = ntohs (si.port); |
1202 | int client = ntohl (si.host); |
1181 | |
1203 | |
1182 | assert (0 < client && client <= conns.size ()); |
1204 | assert (0 < client && client <= conns.size ()); |
1183 | |
1205 | |
1184 | connection *c = conns [client - 1]; |
1206 | connection *c = conns [client - 1]; |
1185 | |
1207 | |
1186 | if (!c->dns) |
1208 | if (!c->dns) |
1187 | c->dns = new dns_connection (c); |
1209 | c->dns = new dns_connection (c); |
1188 | |
1210 | |
1189 | if (!c->dns->snddq.put (pkt)) |
1211 | if (c->dns->snddq.put (pkt)) |
1190 | return false; |
|
|
1191 | |
|
|
1192 | c->dns->tw.trigger (); |
1212 | c->dns->tw (); |
1193 | |
1213 | |
|
|
1214 | // always return true even if the buffer overflows |
1194 | return true; |
1215 | return true; |
1195 | } |
1216 | } |
1196 | |
1217 | |
1197 | void |
1218 | void |
1198 | connection::dnsv4_reset_connection () |
1219 | connection::dnsv4_reset_connection () |
… | |
… | |
1201 | } |
1222 | } |
1202 | |
1223 | |
1203 | #define NEXT(w) do { if (next > (w)) next = w; } while (0) |
1224 | #define NEXT(w) do { if (next > (w)) next = w; } while (0) |
1204 | |
1225 | |
1205 | void |
1226 | void |
1206 | dns_connection::time_cb (time_watcher &w) |
1227 | dns_connection::time_cb (ev::timer &w, int revents) |
1207 | { |
1228 | { |
1208 | // servers have to be polled |
1229 | // servers have to be polled |
1209 | if (THISNODE->dns_port) |
1230 | if (THISNODE->dns_port) |
1210 | return; |
1231 | return; |
1211 | |
1232 | |
1212 | // check for timeouts and (re)transmit |
1233 | // check for timeouts and (re)transmit |
1213 | tstamp next = NOW + poll_interval; |
1234 | tstamp next = ev::now () + poll_interval; |
1214 | dns_snd *send = 0; |
1235 | dns_snd *send = 0; |
1215 | |
1236 | |
1216 | for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin (); |
1237 | for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin (); |
1217 | i != vpn->dns_sndpq.end (); |
1238 | i != vpn->dns_sndpq.end (); |
1218 | ++i) |
1239 | ++i) |
1219 | { |
1240 | { |
1220 | dns_snd *r = *i; |
1241 | dns_snd *r = *i; |
1221 | |
1242 | |
1222 | if (r->timeout <= NOW) |
1243 | if (r->timeout <= ev_now ()) |
1223 | { |
1244 | { |
1224 | if (!send) |
1245 | if (!send) |
1225 | { |
1246 | { |
1226 | send = r; |
1247 | send = r; |
1227 | |
1248 | |
1228 | r->retry++; |
1249 | r->retry++; |
1229 | r->timeout = NOW + (r->retry * min_latency * 8.); |
1250 | r->timeout = ev_now () + (r->retry * min_latency * conf.dns_timeout_factor); |
|
|
1251 | //printf ("RETRY %x (%d, %f)\n", r->seqno, r->retry, r->timeout - ev_now ());//D |
1230 | |
1252 | |
1231 | // the following code changes the query section a bit, forcing |
1253 | // the following code changes the query section a bit, forcing |
1232 | // the forwarder to generate a new request |
1254 | // the forwarder to generate a new request |
1233 | if (r->stdhdr) |
1255 | 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); |
1256 | encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry); |
1237 | } |
|
|
1238 | } |
1257 | } |
1239 | } |
1258 | } |
1240 | else |
1259 | else |
1241 | NEXT (r->timeout); |
1260 | NEXT (r->timeout); |
1242 | } |
1261 | } |
… | |
… | |
1253 | |
1272 | |
1254 | cfg.reset (THISNODE->id); |
1273 | cfg.reset (THISNODE->id); |
1255 | send->gen_syn_req (); |
1274 | send->gen_syn_req (); |
1256 | } |
1275 | } |
1257 | } |
1276 | } |
1258 | else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING |
1277 | else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding |
1259 | && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) |
1278 | && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) |
1260 | { |
1279 | { |
1261 | if (last_sent + send_interval <= NOW) |
1280 | if (last_sent + send_interval <= ev_now ()) |
1262 | { |
1281 | { |
1263 | //printf ("sending data request etc.\n"); //D |
1282 | //printf ("sending data request etc.\n"); //D |
1264 | if (!snddq.empty () || last_received + 1. > NOW) |
1283 | if (!snddq.empty () || last_received + 1. > ev_now ()) |
1265 | { |
1284 | { |
1266 | poll_interval = send_interval; |
1285 | poll_interval = send_interval; |
1267 | NEXT (NOW + send_interval); |
1286 | NEXT (ev_now () + send_interval); |
1268 | } |
1287 | } |
1269 | |
1288 | |
1270 | send = new dns_snd (this); |
1289 | send = new dns_snd (this); |
1271 | send->gen_stream_req (sndseq, snddq); |
1290 | send->gen_stream_req (sndseq, snddq); |
1272 | send->timeout = NOW + min_latency * 8.; |
1291 | send->timeout = ev_now () + min_latency * conf.dns_timeout_factor; |
|
|
1292 | //printf ("SEND %x (%f)\n", send->seqno, send->timeout - ev_now (), min_latency, conf.dns_timeout_factor);//D |
1273 | |
1293 | |
1274 | sndseq = (sndseq + 1) & SEQNO_MASK; |
1294 | sndseq = (sndseq + 1) & SEQNO_MASK; |
1275 | } |
1295 | } |
1276 | else |
1296 | else |
1277 | NEXT (last_sent + send_interval); |
1297 | NEXT (last_sent + send_interval); |
… | |
… | |
1281 | vpn->dns_sndpq.push_back (send); |
1301 | vpn->dns_sndpq.push_back (send); |
1282 | } |
1302 | } |
1283 | |
1303 | |
1284 | if (send) |
1304 | if (send) |
1285 | { |
1305 | { |
1286 | last_sent = NOW; |
1306 | last_sent = ev_now (); |
1287 | sendto (vpn->dnsv4_fd, |
1307 | sendto (vpn->dnsv4_fd, |
1288 | send->pkt->at (0), send->pkt->len, 0, |
1308 | send->pkt->at (0), send->pkt->len, 0, |
1289 | vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); |
1309 | vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); |
1290 | } |
1310 | } |
1291 | |
1311 | |
1292 | slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)", |
1312 | slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)", |
1293 | poll_interval, send_interval, next - NOW, |
1313 | poll_interval, send_interval, next - ev_now (), |
1294 | vpn->dns_sndpq.size (), snddq.size (), |
1314 | vpn->dns_sndpq.size (), snddq.size (), |
1295 | rcvpq.size ()); |
1315 | rcvpq.size ()); |
1296 | |
1316 | |
1297 | // TODO: no idea when this happens, but when next < NOW, we have a problem |
1317 | // TODO: no idea when this happens, but when next < ev_now (), we have a problem |
|
|
1318 | // doesn't seem to happen anymore |
1298 | if (next < NOW + 0.001) |
1319 | if (next < ev_now () + 0.001) |
1299 | next = NOW + 0.1; |
1320 | next = ev_now () + 0.1; |
1300 | |
1321 | |
1301 | w.start (next); |
1322 | w.start (next - ev_now ()); |
1302 | } |
1323 | } |
1303 | |
1324 | |
1304 | #endif |
1325 | #endif |
1305 | |
1326 | |