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Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.19 by pcg, Sun Mar 6 18:34:46 2005 UTC vs.
Revision 1.42 by pcg, Sat Nov 10 05:14:22 2007 UTC

… …
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details. 15 GNU General 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
18 along with gvpe; if not, write to the Free Software 18 along with gvpe; if not, write to the Free Software
19 Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 19 Foundation, Inc. 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20*/ 20*/
21
22// TODO: EDNS0 option to increase dns mtu?
23// TODO: re-write dns packet parsing/creation using a safe mem-buffer
24// to ensure no buffer overflows or similar problems.
21 25
22#include "config.h" 26#include "config.h"
23 27
24#if ENABLE_DNS 28#if ENABLE_DNS
25 29
26// dns processing is EXTREMELY ugly. For obvious(?) reasons. 30// dns processing is EXTREMELY ugly. For obvious(?) reasons.
27// it's a hack, use only in emergency situations please. 31// it's a hack, use only in emergency situations please.
28 32
29#include <cstring> 33#include <cstring>
34#include <cassert>
30 35
31#include <sys/types.h> 36#include <sys/types.h>
32#include <sys/socket.h> 37#include <sys/socket.h>
33#include <sys/wait.h> 38#include <sys/wait.h>
34#include <sys/uio.h> 39#include <sys/uio.h>
… …
43 48
44#include "netcompat.h" 49#include "netcompat.h"
45 50
46#include "vpn.h" 51#include "vpn.h"
47 52
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 53#define MAX_POLL_INTERVAL 5. // how often to poll minimally when the server has no data
50#define ACTIVITY_INTERVAL 5. 54#define ACTIVITY_INTERVAL 5.
51 55
52#define INITIAL_TIMEOUT 0.1 // retry timeouts 56#define INITIAL_TIMEOUT 0.1 // retry timeouts
53#define INITIAL_SYN_TIMEOUT 10. // retry timeout for initial syn 57#define INITIAL_SYN_TIMEOUT 2. // retry timeout for initial syn
54 58
55#define MIN_SEND_INTERVAL 0.01 // wait at least this time between sending requests
56#define MAX_SEND_INTERVAL 0.5 // optimistic? 59#define MAX_SEND_INTERVAL 2. // optimistic?
57 60
58#define MAX_OUTSTANDING 10 // max. outstanding requests
59#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog 61#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 62#define MAX_BACKLOG (64*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE
61 63
62#define MAX_DOMAIN_SIZE 220 // 255 is legal limit, but bind doesn't compress well 64#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 65// 240 leaves about 4 bytes of server reply data
64// every two request bytes less give room for one reply byte 66// every request byte less give room for two reply bytes
65 67
66#define SEQNO_MASK 0x3fff 68#define SEQNO_MASK 0x3fff
67#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) ) 69#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )
68 70
69#define MAX_LBL_SIZE 63 71#define MAX_LBL_SIZE 63
… …
264static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO"); 266static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO");
265 267
266///////////////////////////////////////////////////////////////////////////// 268/////////////////////////////////////////////////////////////////////////////
267 269
268#define HDRSIZE 6 270#define HDRSIZE 6
269 271
270inline void encode_header (char *data, int clientid, int seqno, int retry = 0) 272inline void encode_header (char *data, int clientid, int seqno, int retry = 0)
271{ 273{
272 seqno &= SEQNO_MASK; 274 seqno &= SEQNO_MASK;
273 275
274 u8 hdr[3] = { 276 u8 hdr[3] = {
… …
408struct dns_cfg 410struct dns_cfg
409{ 411{
410 static int next_uid; 412 static int next_uid;
411 413
412 u8 id1, id2, id3, id4; 414 u8 id1, id2, id3, id4;
415
413 u8 version; 416 u8 version;
417 u8 flags;
414 u8 rrtype; 418 u8 rrtype;
415 u8 flags;
416 u8 def_ttl; 419 u8 def_ttl;
417 u8 rcv_cdc; 420
418 u8 snd_cdc;
419 u16 max_size;
420 u16 client; 421 u16 client;
421 u16 uid; // to make request unique 422 u16 uid; // to make request unique
422 423
423 u8 reserved[8]; 424 u16 max_size;
425 u8 seq_cdc;
426 u8 req_cdc;
427
428 u8 rep_cdc;
429 u8 delay; // time in 0.01s units that the server may delay replying packets
430 u8 r3, r4;
431
432 u8 r5, r6, r7, r8;
424 433
425 void reset (int clientid); 434 void reset (int clientid);
426 bool valid (); 435 bool valid ();
427}; 436};
428 437
… …
437 446
438 version = 1; 447 version = 1;
439 448
440 rrtype = RR_TYPE_TXT; 449 rrtype = RR_TYPE_TXT;
441 flags = 0; 450 flags = 0;
442 def_ttl = 1; 451 def_ttl = 0;
452 seq_cdc = 26;
453 req_cdc = 62;
443 rcv_cdc = 0; 454 rep_cdc = 0;
444 snd_cdc = 62;
445 max_size = ntohs (MAX_PKT_SIZE); 455 max_size = htons (MAX_PKT_SIZE);
446 client = ntohs (clientid); 456 client = htons (clientid);
447 uid = next_uid++; 457 uid = next_uid++;
458 delay = 0;
448 459
449 memset (reserved, 0, 8); 460 r3 = r4 = 0;
461 r4 = r5 = r6 = r7 = 0;
450} 462}
451 463
452bool dns_cfg::valid () 464bool dns_cfg::valid ()
453{ 465{
466 // although the protocol itself allows for some configurability,
467 // only the following encoding/decoding settings are implemented.
454 return id1 == 'G' 468 return id1 == 'G'
455 && id2 == 'V' 469 && id2 == 'V'
456 && id3 == 'P' 470 && id3 == 'P'
457 && id4 == 'E' 471 && id4 == 'E'
472 && seq_cdc == 26
473 && req_cdc == 62
474 && rep_cdc == 0
458 && version == 1 475 && version == 1;
459 && flags == 0
460 && rcv_cdc == 0
461 && snd_cdc == 62
462 && max_size == ntohs (MAX_PKT_SIZE);
463} 476}
464 477
465struct dns_packet : net_packet 478struct dns_packet : net_packet
466{ 479{
467 u16 id; 480 u16 id;
468 u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4 481 u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4
469 u16 qdcount, ancount, nscount, arcount; 482 u16 qdcount, ancount, nscount, arcount;
470 483
471 u8 data[MAXSIZE - 6 * 2]; 484 u8 data [MAXSIZE - 6 * 2];
472 485
473 int decode_label (char *data, int size, int &offs); 486 int decode_label (char *data, int size, int &offs);
474}; 487};
475 488
476int dns_packet::decode_label (char *data, int size, int &offs) 489int dns_packet::decode_label (char *data, int size, int &offs)
… …
538 551
539 bool established; 552 bool established;
540 553
541 tstamp last_received; 554 tstamp last_received;
542 tstamp last_sent; 555 tstamp last_sent;
543 double last_latency; 556 double min_latency;
544 double poll_interval, send_interval; 557 double poll_interval, send_interval;
545 558
546 vector<dns_rcv *> rcvpq; 559 vector<dns_rcv *> rcvpq;
547 560
548 byte_stream rcvdq; int rcvseq; 561 byte_stream rcvdq; int rcvseq; int repseq;
549 byte_stream snddq; int sndseq; 562 byte_stream snddq; int sndseq;
550 563
551 void time_cb (time_watcher &w); time_watcher tw; 564 void time_cb (ev::timer &w, int revents); ev::timer tw;
552 void receive_rep (dns_rcv *r); 565 void receive_rep (dns_rcv *r);
553 566
554 dns_connection (connection *c); 567 dns_connection (connection *c);
555 ~dns_connection (); 568 ~dns_connection ();
556}; 569};
… …
575: dns (dns) 588: dns (dns)
576{ 589{
577 timeout = 0; 590 timeout = 0;
578 retry = 0; 591 retry = 0;
579 seqno = 0; 592 seqno = 0;
580 sent = NOW; 593 sent = ev::ev_now ();
581 stdhdr = false; 594 stdhdr = false;
582 595
583 pkt = new dns_packet; 596 pkt = new dns_packet;
584 597
585 pkt->id = next_id (); 598 pkt->id = next_id ();
… …
616void dns_snd::gen_stream_req (int seqno, byte_stream &stream) 629void dns_snd::gen_stream_req (int seqno, byte_stream &stream)
617{ 630{
618 stdhdr = true; 631 stdhdr = true;
619 this->seqno = seqno; 632 this->seqno = seqno;
620 633
621 timeout = NOW + INITIAL_TIMEOUT; 634 timeout = ev::ev_now () + INITIAL_TIMEOUT;
622 635
623 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 636 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
624 pkt->qdcount = htons (1); 637 pkt->qdcount = htons (1);
625 638
626 int offs = 6*2; 639 int offs = 6*2;
… …
661 pkt->len = offs; 674 pkt->len = offs;
662} 675}
663 676
664void dns_snd::gen_syn_req () 677void dns_snd::gen_syn_req ()
665{ 678{
666 timeout = NOW + INITIAL_SYN_TIMEOUT; 679 timeout = ev::ev_now () + INITIAL_SYN_TIMEOUT;
667
668 printf ("send syn\n");//D
669 680
670 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 681 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
671 pkt->qdcount = htons (1); 682 pkt->qdcount = htons (1);
672 683
673 int offs = 6 * 2; 684 int offs = 6 * 2;
… …
712///////////////////////////////////////////////////////////////////////////// 723/////////////////////////////////////////////////////////////////////////////
713 724
714dns_connection::dns_connection (connection *c) 725dns_connection::dns_connection (connection *c)
715: c (c) 726: c (c)
716, rcvdq (MAX_BACKLOG * 2) 727, rcvdq (MAX_BACKLOG * 2)
717, snddq (MAX_BACKLOG * 2) 728, snddq (MAX_BACKLOG)
718, tw (this, &dns_connection::time_cb) 729, tw (this, &dns_connection::time_cb)
719{ 730{
720 vpn = c->vpn; 731 vpn = c->vpn;
721 732
722 established = false; 733 established = false;
723 734
724 rcvseq = sndseq = 0; 735 rcvseq = repseq = sndseq = 0;
725 736
726 last_sent = last_received = 0; 737 last_sent = last_received = 0;
727 poll_interval = MIN_POLL_INTERVAL; 738 poll_interval = 0.5; // starting here
728 send_interval = 0.5; // starting rate 739 send_interval = 0.5; // starting rate
729 last_latency = INITIAL_TIMEOUT; 740 min_latency = INITIAL_TIMEOUT;
730} 741}
731 742
732dns_connection::~dns_connection () 743dns_connection::~dns_connection ()
733{ 744{
734 for (vector<dns_rcv *>::iterator i = rcvpq.begin (); 745 for (vector<dns_rcv *>::iterator i = rcvpq.begin ();
… …
739 750
740void dns_connection::receive_rep (dns_rcv *r) 751void dns_connection::receive_rep (dns_rcv *r)
741{ 752{
742 if (r->datalen) 753 if (r->datalen)
743 { 754 {
744 last_received = NOW; 755 last_received = ev::ev_now ();
745 tw.trigger (); 756 tw ();
746 757
747 poll_interval = send_interval; 758 poll_interval = send_interval;
748 } 759 }
749 else 760 else
750 { 761 {
751 poll_interval *= 1.5; 762 poll_interval *= 1.5;
763
752 if (poll_interval > MAX_POLL_INTERVAL) 764 if (poll_interval > MAX_POLL_INTERVAL)
753 poll_interval = MAX_POLL_INTERVAL; 765 poll_interval = MAX_POLL_INTERVAL;
754 } 766 }
755 767
756 rcvpq.push_back (r); 768 rcvpq.push_back (r);
… …
759 771
760 // find next packet 772 // find next packet
761 for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); ) 773 for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); )
762 if (SEQNO_EQ (rcvseq, (*i)->seqno)) 774 if (SEQNO_EQ (rcvseq, (*i)->seqno))
763 { 775 {
776 //printf ("seqno eq %x %x\n", rcvseq, (*i)->seqno);//D
764 // enter the packet into our input stream 777 // enter the packet into our input stream
765 r = *i; 778 r = *i;
766 779
767 // remove the oldest packet, look forward, as it's oldest first 780 // remove the oldest packet, look forward, as it's oldest first
768 for (vector<dns_rcv *>::iterator j = rcvpq.begin (); j != rcvpq.end (); ++j) 781 for (vector<dns_rcv *>::iterator j = rcvpq.begin (); j != rcvpq.end (); ++j)
769 if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW)) 782 if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW))
770 { 783 {
784 //printf ("seqno RR %x %x\n", (*j)->seqno, rcvseq - MAX_WINDOW);//D
771 delete *j; 785 delete *j;
772 rcvpq.erase (j); 786 rcvpq.erase (j);
773 break; 787 break;
774 } 788 }
775 789
… …
782 } 796 }
783 797
784 while (vpn_packet *pkt = rcvdq.get ()) 798 while (vpn_packet *pkt = rcvdq.get ())
785 { 799 {
786 sockinfo si; 800 sockinfo si;
787 si.host = 0x01010101; si.port = htons (c->conf->id); si.prot = PROT_DNSv4; 801 si.host = htonl (c->conf->id); si.port = 0; si.prot = PROT_DNSv4;
788 802
789 vpn->recv_vpn_packet (pkt, si); 803 vpn->recv_vpn_packet (pkt, si);
790 804
791 delete pkt; 805 delete pkt;
792 } 806 }
… …
806 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR); 820 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR);
807 821
808 if (0 == (flags & (FLAG_RESPONSE | FLAG_OP_MASK)) 822 if (0 == (flags & (FLAG_RESPONSE | FLAG_OP_MASK))
809 && pkt.qdcount == htons (1)) 823 && pkt.qdcount == htons (1))
810 { 824 {
811 char qname[MAXSIZE]; 825 char qname [MAXSIZE];
812 int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs); 826 int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
813 827
814 u16 qtype = pkt [offs++] << 8; qtype |= pkt [offs++]; 828 u16 qtype = pkt [offs++] << 8; qtype |= pkt [offs++];
815 u16 qclass = pkt [offs++] << 8; qclass |= pkt [offs++]; 829 u16 qclass = pkt [offs++] << 8; qclass |= pkt [offs++];
816 830
… …
823 837
824 int dlen = strlen (THISNODE->domain); 838 int dlen = strlen (THISNODE->domain);
825 839
826 if (qclass == RR_CLASS_IN 840 if (qclass == RR_CLASS_IN
827 && qlen > dlen + 1 841 && qlen > dlen + 1
828 && !memcmp (qname + qlen - dlen - 1, THISNODE->domain, dlen)) 842 && !memcmp (qname + qlen - (dlen + 1), THISNODE->domain, dlen))
829 { 843 {
830 // now generate reply 844 // now generate reply
831 pkt.ancount = htons (1); // one answer RR 845 pkt.ancount = htons (1); // one answer RR
832 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_OK); 846 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_OK);
833 847
… …
846 if (0 < client && client <= conns.size ()) 860 if (0 < client && client <= conns.size ())
847 { 861 {
848 connection *c = conns [client - 1]; 862 connection *c = conns [client - 1];
849 dns_connection *dns = c->dns; 863 dns_connection *dns = c->dns;
850 dns_rcv *rcv; 864 dns_rcv *rcv;
851 bool in_seq;
852 865
853 if (dns) 866 if (dns)
854 { 867 {
855 for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); ) 868 for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); )
856 if (SEQNO_EQ ((*i)->seqno, seqno)) 869 if (SEQNO_EQ ((*i)->seqno, seqno))
… …
867 memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len); 880 memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len);
868 881
869 goto duplicate_request; 882 goto duplicate_request;
870 } 883 }
871 884
872 in_seq = dns->rcvseq == seqno;
873
874 // new packet, queue 885 // new packet, queue
875 rcv = new dns_rcv (seqno, data, datalen); 886 rcv = new dns_rcv (seqno, data, datalen);
876 dns->receive_rep (rcv); 887 dns->receive_rep (rcv);
877 } 888 }
878 889
890 {
879 pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section 891 pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section
880 892
881 int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A; 893 int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A;
882 pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type 894 pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type
883 pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class 895 pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
884 pkt [offs++] = 0; pkt [offs++] = 0; 896 pkt [offs++] = 0; pkt [offs++] = 0;
885 pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL 897 pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL
886 898
887 int rdlen_offs = offs += 2; 899 int rdlen_offs = offs += 2;
888 900
901 if (dns)
902 {
889 int dlen = (dns ? ntohs (dns->cfg.max_size) : MAX_PKT_SIZE) - offs; 903 int dlen = ntohs (dns->cfg.max_size) - offs;
904
890 // bind doesn't compress well, so reduce further by one label length 905 // bind doesn't compress well, so reduce further by one label length
891 dlen -= qlen; 906 dlen -= qlen;
892 907
893 if (dns)
894 {
895 // only put data into in-order sequence packets, if 908 // only put data into in-order sequence packets, if
896 // we receive out-of-order packets we generate empty 909 // we receive out-of-order packets we generate empty
897 // replies 910 // replies
898 while (dlen > 1 && !dns->snddq.empty () && in_seq) 911 //printf ("%d - %d & %x (=%d) < %d\n", seqno, dns->repseq, SEQNO_MASK, (seqno - dns->repseq) & SEQNO_MASK, MAX_WINDOW);//D
912 if (((seqno - dns->repseq) & SEQNO_MASK) <= MAX_WINDOW)
899 { 913 {
914 dns->repseq = seqno;
915
916 while (dlen > 1 && !dns->snddq.empty ())
917 {
900 int txtlen = dlen <= 255 ? dlen - 1 : 255; 918 int txtlen = dlen <= 255 ? dlen - 1 : 255;
901 919
902 if (txtlen > dns->snddq.size ()) 920 if (txtlen > dns->snddq.size ())
903 txtlen = dns->snddq.size (); 921 txtlen = dns->snddq.size ();
904 922
905 pkt[offs++] = txtlen; 923 pkt[offs++] = txtlen;
906 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen); 924 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
907 offs += txtlen; 925 offs += txtlen;
908 dns->snddq.remove (txtlen); 926 dns->snddq.remove (txtlen);
909 927
910 dlen -= txtlen + 1; 928 dlen -= txtlen + 1;
929 }
911 } 930 }
912 931
913 // avoid empty TXT rdata 932 // avoid completely empty TXT rdata
914 if (offs == rdlen_offs) 933 if (offs == rdlen_offs)
915 pkt[offs++] = 0; 934 pkt[offs++] = 0;
916 935
917 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ()); 936 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
918 } 937 }
919 else 938 else
920 { 939 {
921 // send RST 940 // send RST
922 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3; 941 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
923 pkt [offs++] = CMD_IP_RST; 942 pkt [offs++] = CMD_IP_RST;
924 } 943 }
925 944
926 int rdlen = offs - rdlen_offs; 945 int rdlen = offs - rdlen_offs;
927 946
928 pkt [rdlen_offs - 2] = rdlen >> 8; 947 pkt [rdlen_offs - 2] = rdlen >> 8;
929 pkt [rdlen_offs - 1] = rdlen; 948 pkt [rdlen_offs - 1] = rdlen;
930 949
931 if (dns) 950 if (dns)
932 { 951 {
933 // now update dns_rcv copy 952 // now update dns_rcv copy
934 rcv->pkt->len = offs; 953 rcv->pkt->len = offs;
935 memcpy (rcv->pkt->at (0), pkt.at (0), offs); 954 memcpy (rcv->pkt->at (0), pkt.at (0), offs);
936 } 955 }
956 }
937 957
938 duplicate_request: ; 958 duplicate_request: ;
939 } 959 }
940 else 960 else
941 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR); 961 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR);
… …
953 pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class 973 pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
954 pkt [offs++] = 0; pkt [offs++] = 0; 974 pkt [offs++] = 0; pkt [offs++] = 0;
955 pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL 975 pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL
956 pkt [offs++] = 0; pkt [offs++] = 4; // rdlength 976 pkt [offs++] = 0; pkt [offs++] = 4; // rdlength
957 977
958 slog (L_INFO, _("DNS: client %d tries to connect"), client); 978 slog (L_INFO, _("DNS: client %d connects"), client);
959 979
960 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3; 980 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
961 pkt [offs++] = CMD_IP_REJ; 981 pkt [offs++] = CMD_IP_REJ;
962 982
963 if (0 < client && client <= conns.size ()) 983 if (0 < client && client <= conns.size ())
… …
997 { 1017 {
998 dns_connection *dns = (*i)->dns; 1018 dns_connection *dns = (*i)->dns;
999 connection *c = dns->c; 1019 connection *c = dns->c;
1000 int seqno = (*i)->seqno; 1020 int seqno = (*i)->seqno;
1001 u8 data[MAXSIZE], *datap = data; 1021 u8 data[MAXSIZE], *datap = data;
1022 //printf ("rcv pkt %x\n", seqno);//D
1002 1023
1003 if ((*i)->retry) 1024 if ((*i)->retry)
1004 { 1025 {
1005 dns->send_interval *= 1.01; 1026 dns->send_interval *= 1.01;
1006 if (dns->send_interval > MAX_SEND_INTERVAL) 1027 if (dns->send_interval > MAX_SEND_INTERVAL)
1007 dns->send_interval = MAX_SEND_INTERVAL; 1028 dns->send_interval = MAX_SEND_INTERVAL;
1008 } 1029 }
1009 else 1030 else
1010 { 1031 {
1011#if 1 1032#if 0
1012 dns->send_interval *= 0.999; 1033 dns->send_interval *= 0.999;
1013#endif 1034#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 1035 // the latency surely puts an upper bound on
1018 // the minimum send interval 1036 // the minimum send interval
1019 double latency = NOW - (*i)->sent; 1037 double latency = ev::ev_now () - (*i)->sent;
1038
1039 if (latency < dns->min_latency)
1020 dns->last_latency = latency; 1040 dns->min_latency = latency;
1021 1041
1022 if (dns->send_interval > latency) 1042 if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor)
1043 dns->send_interval = dns->min_latency * conf.dns_overlap_factor;
1044
1045 if (dns->send_interval < conf.dns_send_interval)
1023 dns->send_interval = latency; 1046 dns->send_interval = conf.dns_send_interval;
1024 } 1047 }
1025 1048
1026 delete *i; 1049 delete *i;
1027 dns_sndpq.erase (i); 1050 dns_sndpq.erase (i);
1028 1051
… …
1133 break; 1156 break;
1134 } 1157 }
1135} 1158}
1136 1159
1137void 1160void
1138vpn::dnsv4_ev (io_watcher &w, short revents) 1161vpn::dnsv4_ev (ev::io &w, int revents)
1139{ 1162{
1140 if (revents & EVENT_READ) 1163 if (revents & EV_READ)
1141 { 1164 {
1142 dns_packet *pkt = new dns_packet; 1165 dns_packet *pkt = new dns_packet;
1143 struct sockaddr_in sa; 1166 struct sockaddr_in sa;
1144 socklen_t sa_len = sizeof (sa); 1167 socklen_t sa_len = sizeof (sa);
1145 1168
1146 pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len); 1169 pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len);
1147 1170
1148 if (pkt->len > 0) 1171 if (pkt->len > 0)
1149 { 1172 {
1150 if (THISNODE->dns_port) 1173 if (ntohs (pkt->flags) & FLAG_RESPONSE)
1174 dnsv4_client (*pkt);
1175 else
1151 { 1176 {
1152 dnsv4_server (*pkt); 1177 dnsv4_server (*pkt);
1153 sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len); 1178 sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len);
1154 } 1179 }
1155 else
1156 dnsv4_client (*pkt);
1157 1180
1158 delete pkt; 1181 delete pkt;
1159 } 1182 }
1160 } 1183 }
1161} 1184}
1162 1185
1163bool 1186bool
1164vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) 1187vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
1165{ 1188{
1166 int client = ntohs (si.port); 1189 int client = ntohl (si.host);
1167 1190
1168 assert (0 < client && client <= conns.size ()); 1191 assert (0 < client && client <= conns.size ());
1169 1192
1170 connection *c = conns [client - 1]; 1193 connection *c = conns [client - 1];
1171 1194
1172 if (!c->dns) 1195 if (!c->dns)
1173 c->dns = new dns_connection (c); 1196 c->dns = new dns_connection (c);
1174 1197
1175 if (!c->dns->snddq.put (pkt)) 1198 if (c->dns->snddq.put (pkt))
1176 return false;
1177
1178 c->dns->tw.trigger (); 1199 c->dns->tw ();
1179 1200
1201 // always return true even if the buffer overflows
1180 return true; 1202 return true;
1181} 1203}
1182 1204
1183void 1205void
1184connection::dnsv4_reset_connection () 1206connection::dnsv4_reset_connection ()
… …
1187} 1209}
1188 1210
1189#define NEXT(w) do { if (next > (w)) next = w; } while (0) 1211#define NEXT(w) do { if (next > (w)) next = w; } while (0)
1190 1212
1191void 1213void
1192dns_connection::time_cb (time_watcher &w) 1214dns_connection::time_cb (ev::timer &w, int revents)
1193{ 1215{
1194 // servers have to be polled 1216 // servers have to be polled
1195 if (THISNODE->dns_port) 1217 if (THISNODE->dns_port)
1196 return; 1218 return;
1197 1219
1198 // check for timeouts and (re)transmit 1220 // check for timeouts and (re)transmit
1199 tstamp next = NOW + poll_interval; 1221 tstamp next = ev::now () + poll_interval;
1200 dns_snd *send = 0; 1222 dns_snd *send = 0;
1201 1223
1202 for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin (); 1224 for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin ();
1203 i != vpn->dns_sndpq.end (); 1225 i != vpn->dns_sndpq.end ();
1204 ++i) 1226 ++i)
1205 { 1227 {
1206 dns_snd *r = *i; 1228 dns_snd *r = *i;
1207 1229
1208 if (r->timeout <= NOW) 1230 if (r->timeout <= ev::ev_now ())
1209 { 1231 {
1210 if (!send) 1232 if (!send)
1211 { 1233 {
1212 send = r; 1234 send = r;
1213 1235
1214 r->retry++; 1236 r->retry++;
1215 r->timeout = NOW + (r->retry * last_latency * 8.); 1237 r->timeout = ev::ev_now () + (r->retry * min_latency * conf.dns_timeout_factor);
1238 //printf ("RETRY %x (%d, %f)\n", r->seqno, r->retry, r->timeout - ev::ev_now ());//D
1216 1239
1217 // the following code changes the query section a bit, forcing 1240 // the following code changes the query section a bit, forcing
1218 // the forwarder to generate a new request 1241 // the forwarder to generate a new request
1219 if (r->stdhdr) 1242 if (r->stdhdr)
1220 {
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);
1222 //encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry); 1243 encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry);
1223 }
1224 } 1244 }
1225 } 1245 }
1226 else 1246 else
1227 NEXT (r->timeout); 1247 NEXT (r->timeout);
1228 } 1248 }
1229 1249
1230 if (last_sent + send_interval <= NOW)
1231 {
1232 if (!send) 1250 if (!send)
1251 {
1252 // generate a new packet, if wise
1253
1254 if (!established)
1233 { 1255 {
1234 // generate a new packet, if wise 1256 if (vpn->dns_sndpq.empty ())
1235
1236 if (!established)
1237 { 1257 {
1238 if (vpn->dns_sndpq.empty ())
1239 {
1240 send = new dns_snd (this); 1258 send = new dns_snd (this);
1241 1259
1242 printf ("new conn %p %d\n", this, c->conf->id);//D
1243 cfg.reset (THISNODE->id); 1260 cfg.reset (THISNODE->id);
1244 send->gen_syn_req (); 1261 send->gen_syn_req ();
1245 }
1246 } 1262 }
1247 else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING 1263 }
1264 else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding
1248 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) 1265 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
1266 {
1267 if (last_sent + send_interval <= ev::ev_now ())
1249 { 1268 {
1250 //printf ("sending data request etc.\n"); //D 1269 //printf ("sending data request etc.\n"); //D
1251 if (!snddq.empty ()) 1270 if (!snddq.empty () || last_received + 1. > ev::ev_now ())
1252 { 1271 {
1253 poll_interval = send_interval; 1272 poll_interval = send_interval;
1254 NEXT (NOW + send_interval); 1273 NEXT (ev::ev_now () + send_interval);
1255 } 1274 }
1256 1275
1257 send = new dns_snd (this); 1276 send = new dns_snd (this);
1258 send->gen_stream_req (sndseq, snddq); 1277 send->gen_stream_req (sndseq, snddq);
1259 send->timeout = NOW + last_latency * 8.; 1278 send->timeout = ev::ev_now () + min_latency * conf.dns_timeout_factor;
1279 //printf ("SEND %x (%f)\n", send->seqno, send->timeout - ev::ev_now (), min_latency, conf.dns_timeout_factor);//D
1260 1280
1261 sndseq = (sndseq + 1) & SEQNO_MASK; 1281 sndseq = (sndseq + 1) & SEQNO_MASK;
1262 } 1282 }
1263 1283 else
1264 if (send) 1284 NEXT (last_sent + send_interval);
1265 vpn->dns_sndpq.push_back (send);
1266 } 1285 }
1267 1286
1268 if (send) 1287 if (send)
1269 { 1288 vpn->dns_sndpq.push_back (send);
1270 last_sent = NOW; 1289 }
1290
1291 if (send)
1292 {
1293 last_sent = ev::ev_now ();
1271 sendto (vpn->dnsv4_fd, 1294 sendto (vpn->dnsv4_fd,
1272 send->pkt->at (0), send->pkt->len, 0, 1295 send->pkt->at (0), send->pkt->len, 0,
1273 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); 1296 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
1274 }
1275 } 1297 }
1276 else
1277 NEXT (last_sent + send_interval);
1278 1298
1279 slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d)", 1299 slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)",
1280 poll_interval, send_interval, next - NOW, 1300 poll_interval, send_interval, next - ev::ev_now (),
1281 vpn->dns_sndpq.size (), snddq.size ()); 1301 vpn->dns_sndpq.size (), snddq.size (),
1302 rcvpq.size ());
1282 1303
1283 // TODO: no idea when this happens, but when next < NOW, we have a problem 1304 // TODO: no idea when this happens, but when next < ev::ev_now (), we have a problem
1284 if (next < NOW + 0.0001) 1305 // doesn't seem to happen anymore
1285 next = NOW + 0.1; 1306 if (next < ev::ev_now () + 0.001)
1307 next = ev::ev_now () + 0.1;
1286 1308
1287 w.start (next); 1309 w.start (next - ev::ev_now ());
1288} 1310}
1289 1311
1290#endif 1312#endif
1291 1313

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