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Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.18 by pcg, Sat Mar 5 19:13:16 2005 UTC vs.
Revision 1.39 by pcg, Tue Apr 26 00:55:56 2005 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{
454 return id1 == 'G' 466 return id1 == 'G'
455 && id2 == 'V' 467 && id2 == 'V'
456 && id3 == 'P' 468 && id3 == 'P'
457 && id4 == 'E' 469 && id4 == 'E'
470 && seq_cdc == 26
471 && req_cdc == 62
472 && rep_cdc == 0
458 && version == 1 473 && version == 1;
459 && flags == 0
460 && rcv_cdc == 0
461 && snd_cdc == 62
462 && max_size == ntohs (MAX_PKT_SIZE);
463} 474}
464 475
465struct dns_packet : net_packet 476struct dns_packet : net_packet
466{ 477{
467 u16 id; 478 u16 id;
468 u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4 479 u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4
469 u16 qdcount, ancount, nscount, arcount; 480 u16 qdcount, ancount, nscount, arcount;
470 481
471 u8 data[MAXSIZE - 6 * 2]; 482 u8 data [MAXSIZE - 6 * 2];
472 483
473 int decode_label (char *data, int size, int &offs); 484 int decode_label (char *data, int size, int &offs);
474}; 485};
475 486
476int dns_packet::decode_label (char *data, int size, int &offs) 487int dns_packet::decode_label (char *data, int size, int &offs)
… …
538 549
539 bool established; 550 bool established;
540 551
541 tstamp last_received; 552 tstamp last_received;
542 tstamp last_sent; 553 tstamp last_sent;
543 double last_latency; 554 double min_latency;
544 double poll_interval, send_interval; 555 double poll_interval, send_interval;
545 556
546 vector<dns_rcv *> rcvpq; 557 vector<dns_rcv *> rcvpq;
547 558
548 byte_stream rcvdq; int rcvseq; 559 byte_stream rcvdq; int rcvseq; int repseq;
549 byte_stream snddq; int sndseq; 560 byte_stream snddq; int sndseq;
550 561
551 void time_cb (time_watcher &w); time_watcher tw; 562 void time_cb (time_watcher &w); time_watcher tw;
552 void receive_rep (dns_rcv *r); 563 void receive_rep (dns_rcv *r);
553 564
… …
622 633
623 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 634 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
624 pkt->qdcount = htons (1); 635 pkt->qdcount = htons (1);
625 636
626 int offs = 6*2; 637 int offs = 6*2;
627 int dlen = MAX_DOMAIN_SIZE - (strlen (THISNODE->domain) + 2); 638 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, 639 // 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 640 // so we need to have space for 2*MAX_DOMAIN_SIZE + header + extra
630 641
631 char enc[256], *encp = enc; 642 char enc[256], *encp = enc;
632 encode_header (enc, THISNODE->id, seqno); 643 encode_header (enc, THISNODE->id, seqno);
… …
650 encp += lbllen; 661 encp += lbllen;
651 662
652 enclen -= lbllen; 663 enclen -= lbllen;
653 } 664 }
654 665
655 append_domain (*pkt, offs, THISNODE->domain); 666 append_domain (*pkt, offs, dns->c->conf->domain);
656 667
657 (*pkt)[offs++] = 0; 668 (*pkt)[offs++] = 0;
658 (*pkt)[offs++] = RR_TYPE_ANY >> 8; (*pkt)[offs++] = RR_TYPE_ANY; 669 (*pkt)[offs++] = RR_TYPE_ANY >> 8; (*pkt)[offs++] = RR_TYPE_ANY;
659 (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN; 670 (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN;
660 671
… …
663 674
664void dns_snd::gen_syn_req () 675void dns_snd::gen_syn_req ()
665{ 676{
666 timeout = NOW + INITIAL_SYN_TIMEOUT; 677 timeout = NOW + INITIAL_SYN_TIMEOUT;
667 678
668 printf ("send syn\n");//D
669
670 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 679 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
671 pkt->qdcount = htons (1); 680 pkt->qdcount = htons (1);
672 681
673 int offs = 6 * 2; 682 int offs = 6 * 2;
674 683
… …
676 685
677 assert (elen <= MAX_LBL_SIZE); 686 assert (elen <= MAX_LBL_SIZE);
678 687
679 (*pkt)[offs] = elen; 688 (*pkt)[offs] = elen;
680 offs += elen + 1; 689 offs += elen + 1;
681 append_domain (*pkt, offs, THISNODE->domain); 690 append_domain (*pkt, offs, dns->c->conf->domain);
682 691
683 (*pkt)[offs++] = 0; 692 (*pkt)[offs++] = 0;
684 (*pkt)[offs++] = RR_TYPE_A >> 8; (*pkt)[offs++] = RR_TYPE_A; 693 (*pkt)[offs++] = RR_TYPE_A >> 8; (*pkt)[offs++] = RR_TYPE_A;
685 (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN; 694 (*pkt)[offs++] = RR_CLASS_IN >> 8; (*pkt)[offs++] = RR_CLASS_IN;
686 695
… …
712///////////////////////////////////////////////////////////////////////////// 721/////////////////////////////////////////////////////////////////////////////
713 722
714dns_connection::dns_connection (connection *c) 723dns_connection::dns_connection (connection *c)
715: c (c) 724: c (c)
716, rcvdq (MAX_BACKLOG * 2) 725, rcvdq (MAX_BACKLOG * 2)
717, snddq (MAX_BACKLOG * 2) 726, snddq (MAX_BACKLOG)
718, tw (this, &dns_connection::time_cb) 727, tw (this, &dns_connection::time_cb)
719{ 728{
720 vpn = c->vpn; 729 vpn = c->vpn;
721 730
722 established = false; 731 established = false;
723 732
724 rcvseq = sndseq = 0; 733 rcvseq = repseq = sndseq = 0;
725 734
726 last_sent = last_received = 0; 735 last_sent = last_received = 0;
727 poll_interval = MIN_POLL_INTERVAL; 736 poll_interval = 0.5; // starting here
728 send_interval = 0.5; // starting rate 737 send_interval = 0.5; // starting rate
729 last_latency = INITIAL_TIMEOUT; 738 min_latency = INITIAL_TIMEOUT;
730} 739}
731 740
732dns_connection::~dns_connection () 741dns_connection::~dns_connection ()
733{ 742{
734 for (vector<dns_rcv *>::iterator i = rcvpq.begin (); 743 for (vector<dns_rcv *>::iterator i = rcvpq.begin ();
… …
747 poll_interval = send_interval; 756 poll_interval = send_interval;
748 } 757 }
749 else 758 else
750 { 759 {
751 poll_interval *= 1.5; 760 poll_interval *= 1.5;
761
752 if (poll_interval > MAX_POLL_INTERVAL) 762 if (poll_interval > MAX_POLL_INTERVAL)
753 poll_interval = MAX_POLL_INTERVAL; 763 poll_interval = MAX_POLL_INTERVAL;
754 } 764 }
755 765
756 rcvpq.push_back (r); 766 rcvpq.push_back (r);
… …
782 } 792 }
783 793
784 while (vpn_packet *pkt = rcvdq.get ()) 794 while (vpn_packet *pkt = rcvdq.get ())
785 { 795 {
786 sockinfo si; 796 sockinfo si;
787 si.host = 0x01010101; si.port = htons (c->conf->id); si.prot = PROT_DNSv4; 797 si.host = htonl (c->conf->id); si.port = 0; si.prot = PROT_DNSv4;
788 798
789 vpn->recv_vpn_packet (pkt, si); 799 vpn->recv_vpn_packet (pkt, si);
790 800
791 delete pkt; 801 delete pkt;
792 } 802 }
… …
806 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR); 816 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR);
807 817
808 if (0 == (flags & (FLAG_RESPONSE | FLAG_OP_MASK)) 818 if (0 == (flags & (FLAG_RESPONSE | FLAG_OP_MASK))
809 && pkt.qdcount == htons (1)) 819 && pkt.qdcount == htons (1))
810 { 820 {
811 char qname[MAXSIZE]; 821 char qname [MAXSIZE];
812 int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs); 822 int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
813 823
814 u16 qtype = pkt [offs++] << 8; qtype |= pkt [offs++]; 824 u16 qtype = pkt [offs++] << 8; qtype |= pkt [offs++];
815 u16 qclass = pkt [offs++] << 8; qclass |= pkt [offs++]; 825 u16 qclass = pkt [offs++] << 8; qclass |= pkt [offs++];
816 826
… …
823 833
824 int dlen = strlen (THISNODE->domain); 834 int dlen = strlen (THISNODE->domain);
825 835
826 if (qclass == RR_CLASS_IN 836 if (qclass == RR_CLASS_IN
827 && qlen > dlen + 1 837 && qlen > dlen + 1
828 && !memcmp (qname + qlen - dlen - 1, THISNODE->domain, dlen)) 838 && !memcmp (qname + qlen - (dlen + 1), THISNODE->domain, dlen))
829 { 839 {
830 // now generate reply 840 // now generate reply
831 pkt.ancount = htons (1); // one answer RR 841 pkt.ancount = htons (1); // one answer RR
832 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_OK); 842 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_OK);
833 843
… …
846 if (0 < client && client <= conns.size ()) 856 if (0 < client && client <= conns.size ())
847 { 857 {
848 connection *c = conns [client - 1]; 858 connection *c = conns [client - 1];
849 dns_connection *dns = c->dns; 859 dns_connection *dns = c->dns;
850 dns_rcv *rcv; 860 dns_rcv *rcv;
851 bool in_seq;
852 861
853 if (dns) 862 if (dns)
854 { 863 {
855 for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); ) 864 for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); )
856 if (SEQNO_EQ ((*i)->seqno, seqno)) 865 if (SEQNO_EQ ((*i)->seqno, seqno))
… …
867 memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len); 876 memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len);
868 877
869 goto duplicate_request; 878 goto duplicate_request;
870 } 879 }
871 880
872 in_seq = dns->rcvseq == seqno;
873
874 // new packet, queue 881 // new packet, queue
875 rcv = new dns_rcv (seqno, data, datalen); 882 rcv = new dns_rcv (seqno, data, datalen);
876 dns->receive_rep (rcv); 883 dns->receive_rep (rcv);
877 } 884 }
878 885
886 {
879 pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section 887 pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section
880 888
881 int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A; 889 int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A;
882 pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type 890 pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type
883 pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class 891 pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
884 pkt [offs++] = 0; pkt [offs++] = 0; 892 pkt [offs++] = 0; pkt [offs++] = 0;
885 pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL 893 pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL
886 894
887 int rdlen_offs = offs += 2; 895 int rdlen_offs = offs += 2;
888 896
897 if (dns)
898 {
889 int dlen = (dns ? ntohs (dns->cfg.max_size) : MAX_PKT_SIZE) - offs; 899 int dlen = ntohs (dns->cfg.max_size) - offs;
900
890 // bind doesn't compress well, so reduce further by one label length 901 // bind doesn't compress well, so reduce further by one label length
891 dlen -= qlen; 902 dlen -= qlen;
892 903
893 if (dns)
894 {
895 // only put data into in-order sequence packets, if 904 // only put data into in-order sequence packets, if
896 // we receive out-of-order packets we generate empty 905 // we receive out-of-order packets we generate empty
897 // replies 906 // replies
898 while (dlen > 1 && !dns->snddq.empty () && in_seq) 907 //printf ("%d - %d & %x (=%d) < %d\n", seqno, dns->repseq, SEQNO_MASK, (seqno - dns->repseq) & SEQNO_MASK, MAX_WINDOW);//D
908 if (((seqno - dns->repseq) & SEQNO_MASK) <= MAX_WINDOW)
899 { 909 {
910 dns->repseq = seqno;
911
912 while (dlen > 1 && !dns->snddq.empty ())
913 {
900 int txtlen = dlen <= 255 ? dlen - 1 : 255; 914 int txtlen = dlen <= 255 ? dlen - 1 : 255;
901 915
902 if (txtlen > dns->snddq.size ()) 916 if (txtlen > dns->snddq.size ())
903 txtlen = dns->snddq.size (); 917 txtlen = dns->snddq.size ();
904 918
905 pkt[offs++] = txtlen; 919 pkt[offs++] = txtlen;
906 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen); 920 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
907 offs += txtlen; 921 offs += txtlen;
908 dns->snddq.remove (txtlen); 922 dns->snddq.remove (txtlen);
909 923
910 dlen -= txtlen + 1; 924 dlen -= txtlen + 1;
925 }
911 } 926 }
912 927
913 // avoid empty TXT rdata 928 // avoid completely empty TXT rdata
914 if (offs == rdlen_offs) 929 if (offs == rdlen_offs)
915 pkt[offs++] = 0; 930 pkt[offs++] = 0;
916 931
917 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ()); 932 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
918 } 933 }
919 else 934 else
920 { 935 {
921 // send RST 936 // send RST
922 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3; 937 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
923 pkt [offs++] = CMD_IP_RST; 938 pkt [offs++] = CMD_IP_RST;
924 } 939 }
925 940
926 int rdlen = offs - rdlen_offs; 941 int rdlen = offs - rdlen_offs;
927 942
928 pkt [rdlen_offs - 2] = rdlen >> 8; 943 pkt [rdlen_offs - 2] = rdlen >> 8;
929 pkt [rdlen_offs - 1] = rdlen; 944 pkt [rdlen_offs - 1] = rdlen;
930 945
931 if (dns) 946 if (dns)
932 { 947 {
933 // now update dns_rcv copy 948 // now update dns_rcv copy
934 rcv->pkt->len = offs; 949 rcv->pkt->len = offs;
935 memcpy (rcv->pkt->at (0), pkt.at (0), offs); 950 memcpy (rcv->pkt->at (0), pkt.at (0), offs);
936 } 951 }
952 }
937 953
938 duplicate_request: ; 954 duplicate_request: ;
939 } 955 }
940 else 956 else
941 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR); 957 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR);
… …
953 pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class 969 pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
954 pkt [offs++] = 0; pkt [offs++] = 0; 970 pkt [offs++] = 0; pkt [offs++] = 0;
955 pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL 971 pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL
956 pkt [offs++] = 0; pkt [offs++] = 4; // rdlength 972 pkt [offs++] = 0; pkt [offs++] = 4; // rdlength
957 973
958 slog (L_INFO, _("DNS: client %d tries to connect"), client); 974 slog (L_INFO, _("DNS: client %d connects"), client);
959 975
960 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3; 976 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
961 pkt [offs++] = CMD_IP_REJ; 977 pkt [offs++] = CMD_IP_REJ;
962 978
963 if (0 < client && client <= conns.size ()) 979 if (0 < client && client <= conns.size ())
… …
1006 if (dns->send_interval > MAX_SEND_INTERVAL) 1022 if (dns->send_interval > MAX_SEND_INTERVAL)
1007 dns->send_interval = MAX_SEND_INTERVAL; 1023 dns->send_interval = MAX_SEND_INTERVAL;
1008 } 1024 }
1009 else 1025 else
1010 { 1026 {
1011#if 1 1027#if 0
1012 dns->send_interval *= 0.999; 1028 dns->send_interval *= 0.999;
1013#endif 1029#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 1030 // the latency surely puts an upper bound on
1018 // the minimum send interval 1031 // the minimum send interval
1019 double latency = NOW - (*i)->sent; 1032 double latency = NOW - (*i)->sent;
1033
1034 if (latency < dns->min_latency)
1020 dns->last_latency = latency; 1035 dns->min_latency = latency;
1021 1036
1022 if (dns->send_interval > latency) 1037 if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor)
1038 dns->send_interval = dns->min_latency * conf.dns_overlap_factor;
1039
1040 if (dns->send_interval < conf.dns_send_interval)
1023 dns->send_interval = latency; 1041 dns->send_interval = conf.dns_send_interval;
1024 } 1042 }
1025 1043
1026 delete *i; 1044 delete *i;
1027 dns_sndpq.erase (i); 1045 dns_sndpq.erase (i);
1028 1046
… …
1145 1163
1146 pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len); 1164 pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len);
1147 1165
1148 if (pkt->len > 0) 1166 if (pkt->len > 0)
1149 { 1167 {
1150 if (THISNODE->dns_port) 1168 if (ntohs (pkt->flags) & FLAG_RESPONSE)
1169 dnsv4_client (*pkt);
1170 else
1151 { 1171 {
1152 dnsv4_server (*pkt); 1172 dnsv4_server (*pkt);
1153 sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len); 1173 sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len);
1154 } 1174 }
1155 else
1156 dnsv4_client (*pkt);
1157 1175
1158 delete pkt; 1176 delete pkt;
1159 } 1177 }
1160 } 1178 }
1161} 1179}
1162 1180
1163bool 1181bool
1164vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) 1182vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
1165{ 1183{
1166 int client = ntohs (si.port); 1184 int client = ntohl (si.host);
1167 1185
1168 assert (0 < client && client <= conns.size ()); 1186 assert (0 < client && client <= conns.size ());
1169 1187
1170 connection *c = conns [client - 1]; 1188 connection *c = conns [client - 1];
1171 1189
1172 if (!c->dns) 1190 if (!c->dns)
1173 c->dns = new dns_connection (c); 1191 c->dns = new dns_connection (c);
1174 1192
1175 if (!c->dns->snddq.put (pkt)) 1193 if (c->dns->snddq.put (pkt))
1176 return false;
1177
1178 c->dns->tw.trigger (); 1194 c->dns->tw.trigger ();
1179 1195
1196 // always return true even if the buffer overflows
1180 return true; 1197 return true;
1181} 1198}
1182 1199
1183void 1200void
1184connection::dnsv4_reset_connection () 1201connection::dnsv4_reset_connection ()
… …
1210 if (!send) 1227 if (!send)
1211 { 1228 {
1212 send = r; 1229 send = r;
1213 1230
1214 r->retry++; 1231 r->retry++;
1215 r->timeout = NOW + (r->retry * last_latency * 8.); 1232 r->timeout = NOW + (r->retry * min_latency * conf.dns_timeout_factor);
1216 1233
1217 // the following code changes the query section a bit, forcing 1234 // the following code changes the query section a bit, forcing
1218 // the forwarder to generate a new request 1235 // the forwarder to generate a new request
1219 if (r->stdhdr) 1236 if (r->stdhdr)
1220 { 1237 {
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); 1238 //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); 1239 //encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry);
1223 } 1240 }
1224 } 1241 }
1225 } 1242 }
1226 else 1243 else
1227 NEXT (r->timeout); 1244 NEXT (r->timeout);
1228 } 1245 }
1229 1246
1230 if (last_sent + send_interval <= NOW)
1231 {
1232 if (!send) 1247 if (!send)
1248 {
1249 // generate a new packet, if wise
1250
1251 if (!established)
1233 { 1252 {
1234 // generate a new packet, if wise 1253 if (vpn->dns_sndpq.empty ())
1235
1236 if (!established)
1237 { 1254 {
1238 if (vpn->dns_sndpq.empty ())
1239 {
1240 send = new dns_snd (this); 1255 send = new dns_snd (this);
1241 1256
1242 printf ("new conn %p %d\n", this, c->conf->id);//D
1243 cfg.reset (THISNODE->id); 1257 cfg.reset (THISNODE->id);
1244 send->gen_syn_req (); 1258 send->gen_syn_req ();
1245 }
1246 } 1259 }
1247 else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING 1260 }
1261 else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding
1248 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) 1262 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
1263 {
1264 if (last_sent + send_interval <= NOW)
1249 { 1265 {
1250 //printf ("sending data request etc.\n"); //D 1266 //printf ("sending data request etc.\n"); //D
1251 if (!snddq.empty ()) 1267 if (!snddq.empty () || last_received + 1. > NOW)
1252 { 1268 {
1253 poll_interval = send_interval; 1269 poll_interval = send_interval;
1254 NEXT (NOW + send_interval); 1270 NEXT (NOW + send_interval);
1255 } 1271 }
1256 1272
1257 send = new dns_snd (this); 1273 send = new dns_snd (this);
1258 send->gen_stream_req (sndseq, snddq); 1274 send->gen_stream_req (sndseq, snddq);
1259 send->timeout = NOW + last_latency * 8.; 1275 send->timeout = NOW + min_latency * conf.dns_timeout_factor;
1260 1276
1261 sndseq = (sndseq + 1) & SEQNO_MASK; 1277 sndseq = (sndseq + 1) & SEQNO_MASK;
1262 } 1278 }
1263 1279 else
1264 if (send) 1280 NEXT (last_sent + send_interval);
1265 vpn->dns_sndpq.push_back (send);
1266 } 1281 }
1267 1282
1268 if (send) 1283 if (send)
1269 { 1284 vpn->dns_sndpq.push_back (send);
1285 }
1286
1287 if (send)
1288 {
1270 last_sent = NOW; 1289 last_sent = NOW;
1271 sendto (vpn->dnsv4_fd, 1290 sendto (vpn->dnsv4_fd,
1272 send->pkt->at (0), send->pkt->len, 0, 1291 send->pkt->at (0), send->pkt->len, 0,
1273 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); 1292 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
1274 }
1275 } 1293 }
1276 else
1277 NEXT (last_sent + send_interval);
1278 1294
1279 slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d)", 1295 slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)",
1280 poll_interval, send_interval, next - NOW, 1296 poll_interval, send_interval, next - NOW,
1281 vpn->dns_sndpq.size (), snddq.size ()); 1297 vpn->dns_sndpq.size (), snddq.size (),
1298 rcvpq.size ());
1282 1299
1283 // TODO: no idea when this happens, but when next < NOW, we have a problem 1300 // TODO: no idea when this happens, but when next < NOW, we have a problem
1301 // doesn't seem to happen anymore
1284 if (next < NOW + 0.0001) 1302 if (next < NOW + 0.001)
1285 next = NOW + 0.1; 1303 next = NOW + 0.1;
1286 1304
1287 w.start (next); 1305 w.start (next);
1288} 1306}
1289 1307

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