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Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.20 by pcg, Sun Mar 6 21:32:15 2005 UTC vs.
Revision 1.40 by pcg, Sat Jul 9 20:29:29 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
… …
44 48
45#include "netcompat.h" 49#include "netcompat.h"
46 50
47#include "vpn.h" 51#include "vpn.h"
48 52
49#define MIN_POLL_INTERVAL .02 // how often to poll minimally when the server has data
50#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
51#define ACTIVITY_INTERVAL 5. 54#define ACTIVITY_INTERVAL 5.
52 55
53#define INITIAL_TIMEOUT 0.1 // retry timeouts 56#define INITIAL_TIMEOUT 0.1 // retry timeouts
54#define INITIAL_SYN_TIMEOUT 10. // retry timeout for initial syn 57#define INITIAL_SYN_TIMEOUT 2. // retry timeout for initial syn
55 58
56#define MIN_SEND_INTERVAL 0.01 // wait at least this time between sending requests
57#define MAX_SEND_INTERVAL 0.5 // optimistic? 59#define MAX_SEND_INTERVAL 2. // optimistic?
58 60
59#define MAX_OUTSTANDING 10 // max. outstanding requests
60#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog 61#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 62#define MAX_BACKLOG (64*1024) // size of gvpe protocol backlog (bytes), must be > MAXSIZE
62 63
63#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
64// 240 leaves about 4 bytes of server reply data 65// 240 leaves about 4 bytes of server reply data
65// every two request bytes less give room for one reply byte 66// every request byte less give room for two reply bytes
66 67
67#define SEQNO_MASK 0x3fff 68#define SEQNO_MASK 0x3fff
68#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) ) 69#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )
69 70
70#define MAX_LBL_SIZE 63 71#define MAX_LBL_SIZE 63
… …
265static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO"); 266static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO");
266 267
267///////////////////////////////////////////////////////////////////////////// 268/////////////////////////////////////////////////////////////////////////////
268 269
269#define HDRSIZE 6 270#define HDRSIZE 6
270 271
271inline 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)
272{ 273{
273 seqno &= SEQNO_MASK; 274 seqno &= SEQNO_MASK;
274 275
275 u8 hdr[3] = { 276 u8 hdr[3] = {
… …
409struct dns_cfg 410struct dns_cfg
410{ 411{
411 static int next_uid; 412 static int next_uid;
412 413
413 u8 id1, id2, id3, id4; 414 u8 id1, id2, id3, id4;
415
414 u8 version; 416 u8 version;
417 u8 flags;
415 u8 rrtype; 418 u8 rrtype;
416 u8 flags;
417 u8 def_ttl; 419 u8 def_ttl;
418 u8 rcv_cdc; 420
419 u8 snd_cdc;
420 u16 max_size;
421 u16 client; 421 u16 client;
422 u16 uid; // to make request unique 422 u16 uid; // to make request unique
423 423
424 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;
425 433
426 void reset (int clientid); 434 void reset (int clientid);
427 bool valid (); 435 bool valid ();
428}; 436};
429 437
… …
438 446
439 version = 1; 447 version = 1;
440 448
441 rrtype = RR_TYPE_TXT; 449 rrtype = RR_TYPE_TXT;
442 flags = 0; 450 flags = 0;
443 def_ttl = 1; 451 def_ttl = 0;
452 seq_cdc = 26;
453 req_cdc = 62;
444 rcv_cdc = 0; 454 rep_cdc = 0;
445 snd_cdc = 62;
446 max_size = ntohs (MAX_PKT_SIZE); 455 max_size = htons (MAX_PKT_SIZE);
447 client = ntohs (clientid); 456 client = htons (clientid);
448 uid = next_uid++; 457 uid = next_uid++;
458 delay = 0;
449 459
450 memset (reserved, 0, 8); 460 r3 = r4 = 0;
461 r4 = r5 = r6 = r7 = 0;
451} 462}
452 463
453bool dns_cfg::valid () 464bool dns_cfg::valid ()
454{ 465{
466 // although the protocol itself allows for some configurability,
467 // only the following encoding/decoding settings are implemented.
455 return id1 == 'G' 468 return id1 == 'G'
456 && id2 == 'V' 469 && id2 == 'V'
457 && id3 == 'P' 470 && id3 == 'P'
458 && id4 == 'E' 471 && id4 == 'E'
472 && seq_cdc == 26
473 && req_cdc == 62
474 && rep_cdc == 0
459 && version == 1 475 && version == 1;
460 && flags == 0
461 && rcv_cdc == 0
462 && snd_cdc == 62
463 && max_size == ntohs (MAX_PKT_SIZE);
464} 476}
465 477
466struct dns_packet : net_packet 478struct dns_packet : net_packet
467{ 479{
468 u16 id; 480 u16 id;
469 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
470 u16 qdcount, ancount, nscount, arcount; 482 u16 qdcount, ancount, nscount, arcount;
471 483
472 u8 data[MAXSIZE - 6 * 2]; 484 u8 data [MAXSIZE - 6 * 2];
473 485
474 int decode_label (char *data, int size, int &offs); 486 int decode_label (char *data, int size, int &offs);
475}; 487};
476 488
477int dns_packet::decode_label (char *data, int size, int &offs) 489int dns_packet::decode_label (char *data, int size, int &offs)
… …
539 551
540 bool established; 552 bool established;
541 553
542 tstamp last_received; 554 tstamp last_received;
543 tstamp last_sent; 555 tstamp last_sent;
544 double last_latency; 556 double min_latency;
545 double poll_interval, send_interval; 557 double poll_interval, send_interval;
546 558
547 vector<dns_rcv *> rcvpq; 559 vector<dns_rcv *> rcvpq;
548 560
549 byte_stream rcvdq; int rcvseq; 561 byte_stream rcvdq; int rcvseq; int repseq;
550 byte_stream snddq; int sndseq; 562 byte_stream snddq; int sndseq;
551 563
552 void time_cb (time_watcher &w); time_watcher tw; 564 void time_cb (time_watcher &w); time_watcher tw;
553 void receive_rep (dns_rcv *r); 565 void receive_rep (dns_rcv *r);
554 566
… …
664 676
665void dns_snd::gen_syn_req () 677void dns_snd::gen_syn_req ()
666{ 678{
667 timeout = NOW + INITIAL_SYN_TIMEOUT; 679 timeout = NOW + INITIAL_SYN_TIMEOUT;
668 680
669 printf ("send syn\n");//D
670
671 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 681 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
672 pkt->qdcount = htons (1); 682 pkt->qdcount = htons (1);
673 683
674 int offs = 6 * 2; 684 int offs = 6 * 2;
675 685
… …
713///////////////////////////////////////////////////////////////////////////// 723/////////////////////////////////////////////////////////////////////////////
714 724
715dns_connection::dns_connection (connection *c) 725dns_connection::dns_connection (connection *c)
716: c (c) 726: c (c)
717, rcvdq (MAX_BACKLOG * 2) 727, rcvdq (MAX_BACKLOG * 2)
718, snddq (MAX_BACKLOG * 2) 728, snddq (MAX_BACKLOG)
719, tw (this, &dns_connection::time_cb) 729, tw (this, &dns_connection::time_cb)
720{ 730{
721 vpn = c->vpn; 731 vpn = c->vpn;
722 732
723 established = false; 733 established = false;
724 734
725 rcvseq = sndseq = 0; 735 rcvseq = repseq = sndseq = 0;
726 736
727 last_sent = last_received = 0; 737 last_sent = last_received = 0;
728 poll_interval = MIN_POLL_INTERVAL; 738 poll_interval = 0.5; // starting here
729 send_interval = 0.5; // starting rate 739 send_interval = 0.5; // starting rate
730 last_latency = INITIAL_TIMEOUT; 740 min_latency = INITIAL_TIMEOUT;
731} 741}
732 742
733dns_connection::~dns_connection () 743dns_connection::~dns_connection ()
734{ 744{
735 for (vector<dns_rcv *>::iterator i = rcvpq.begin (); 745 for (vector<dns_rcv *>::iterator i = rcvpq.begin ();
… …
748 poll_interval = send_interval; 758 poll_interval = send_interval;
749 } 759 }
750 else 760 else
751 { 761 {
752 poll_interval *= 1.5; 762 poll_interval *= 1.5;
763
753 if (poll_interval > MAX_POLL_INTERVAL) 764 if (poll_interval > MAX_POLL_INTERVAL)
754 poll_interval = MAX_POLL_INTERVAL; 765 poll_interval = MAX_POLL_INTERVAL;
755 } 766 }
756 767
757 rcvpq.push_back (r); 768 rcvpq.push_back (r);
… …
783 } 794 }
784 795
785 while (vpn_packet *pkt = rcvdq.get ()) 796 while (vpn_packet *pkt = rcvdq.get ())
786 { 797 {
787 sockinfo si; 798 sockinfo si;
788 si.host = 0x01010101; si.port = htons (c->conf->id); si.prot = PROT_DNSv4; 799 si.host = htonl (c->conf->id); si.port = 0; si.prot = PROT_DNSv4;
789 800
790 vpn->recv_vpn_packet (pkt, si); 801 vpn->recv_vpn_packet (pkt, si);
791 802
792 delete pkt; 803 delete pkt;
793 } 804 }
… …
807 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR); 818 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR);
808 819
809 if (0 == (flags & (FLAG_RESPONSE | FLAG_OP_MASK)) 820 if (0 == (flags & (FLAG_RESPONSE | FLAG_OP_MASK))
810 && pkt.qdcount == htons (1)) 821 && pkt.qdcount == htons (1))
811 { 822 {
812 char qname[MAXSIZE]; 823 char qname [MAXSIZE];
813 int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs); 824 int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
814 825
815 u16 qtype = pkt [offs++] << 8; qtype |= pkt [offs++]; 826 u16 qtype = pkt [offs++] << 8; qtype |= pkt [offs++];
816 u16 qclass = pkt [offs++] << 8; qclass |= pkt [offs++]; 827 u16 qclass = pkt [offs++] << 8; qclass |= pkt [offs++];
817 828
… …
824 835
825 int dlen = strlen (THISNODE->domain); 836 int dlen = strlen (THISNODE->domain);
826 837
827 if (qclass == RR_CLASS_IN 838 if (qclass == RR_CLASS_IN
828 && qlen > dlen + 1 839 && qlen > dlen + 1
829 && !memcmp (qname + qlen - dlen - 1, THISNODE->domain, dlen)) 840 && !memcmp (qname + qlen - (dlen + 1), THISNODE->domain, dlen))
830 { 841 {
831 // now generate reply 842 // now generate reply
832 pkt.ancount = htons (1); // one answer RR 843 pkt.ancount = htons (1); // one answer RR
833 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_OK); 844 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_OK);
834 845
… …
847 if (0 < client && client <= conns.size ()) 858 if (0 < client && client <= conns.size ())
848 { 859 {
849 connection *c = conns [client - 1]; 860 connection *c = conns [client - 1];
850 dns_connection *dns = c->dns; 861 dns_connection *dns = c->dns;
851 dns_rcv *rcv; 862 dns_rcv *rcv;
852 bool in_seq;
853 863
854 if (dns) 864 if (dns)
855 { 865 {
856 for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); ) 866 for (vector<dns_rcv *>::iterator i = dns->rcvpq.end (); i-- != dns->rcvpq.begin (); )
857 if (SEQNO_EQ ((*i)->seqno, seqno)) 867 if (SEQNO_EQ ((*i)->seqno, seqno))
… …
868 memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len); 878 memcpy (pkt.at (0), r->pkt->at (0), offs = r->pkt->len);
869 879
870 goto duplicate_request; 880 goto duplicate_request;
871 } 881 }
872 882
873 in_seq = dns->rcvseq == seqno;
874
875 // new packet, queue 883 // new packet, queue
876 rcv = new dns_rcv (seqno, data, datalen); 884 rcv = new dns_rcv (seqno, data, datalen);
877 dns->receive_rep (rcv); 885 dns->receive_rep (rcv);
878 } 886 }
879 887
888 {
880 pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section 889 pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section
881 890
882 int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A; 891 int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A;
883 pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type 892 pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type
884 pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class 893 pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
885 pkt [offs++] = 0; pkt [offs++] = 0; 894 pkt [offs++] = 0; pkt [offs++] = 0;
886 pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL 895 pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL
887 896
888 int rdlen_offs = offs += 2; 897 int rdlen_offs = offs += 2;
889 898
899 if (dns)
900 {
890 int dlen = (dns ? ntohs (dns->cfg.max_size) : MAX_PKT_SIZE) - offs; 901 int dlen = ntohs (dns->cfg.max_size) - offs;
902
891 // bind doesn't compress well, so reduce further by one label length 903 // bind doesn't compress well, so reduce further by one label length
892 dlen -= qlen; 904 dlen -= qlen;
893 905
894 if (dns)
895 {
896 // only put data into in-order sequence packets, if 906 // only put data into in-order sequence packets, if
897 // we receive out-of-order packets we generate empty 907 // we receive out-of-order packets we generate empty
898 // replies 908 // replies
899 while (dlen > 1 && !dns->snddq.empty () && in_seq) 909 //printf ("%d - %d & %x (=%d) < %d\n", seqno, dns->repseq, SEQNO_MASK, (seqno - dns->repseq) & SEQNO_MASK, MAX_WINDOW);//D
910 if (((seqno - dns->repseq) & SEQNO_MASK) <= MAX_WINDOW)
900 { 911 {
912 dns->repseq = seqno;
913
914 while (dlen > 1 && !dns->snddq.empty ())
915 {
901 int txtlen = dlen <= 255 ? dlen - 1 : 255; 916 int txtlen = dlen <= 255 ? dlen - 1 : 255;
902 917
903 if (txtlen > dns->snddq.size ()) 918 if (txtlen > dns->snddq.size ())
904 txtlen = dns->snddq.size (); 919 txtlen = dns->snddq.size ();
905 920
906 pkt[offs++] = txtlen; 921 pkt[offs++] = txtlen;
907 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen); 922 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
908 offs += txtlen; 923 offs += txtlen;
909 dns->snddq.remove (txtlen); 924 dns->snddq.remove (txtlen);
910 925
911 dlen -= txtlen + 1; 926 dlen -= txtlen + 1;
927 }
912 } 928 }
913 929
914 // avoid empty TXT rdata 930 // avoid completely empty TXT rdata
915 if (offs == rdlen_offs) 931 if (offs == rdlen_offs)
916 pkt[offs++] = 0; 932 pkt[offs++] = 0;
917 933
918 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ()); 934 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
919 } 935 }
920 else 936 else
921 { 937 {
922 // send RST 938 // send RST
923 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3; 939 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
924 pkt [offs++] = CMD_IP_RST; 940 pkt [offs++] = CMD_IP_RST;
925 } 941 }
926 942
927 int rdlen = offs - rdlen_offs; 943 int rdlen = offs - rdlen_offs;
928 944
929 pkt [rdlen_offs - 2] = rdlen >> 8; 945 pkt [rdlen_offs - 2] = rdlen >> 8;
930 pkt [rdlen_offs - 1] = rdlen; 946 pkt [rdlen_offs - 1] = rdlen;
931 947
932 if (dns) 948 if (dns)
933 { 949 {
934 // now update dns_rcv copy 950 // now update dns_rcv copy
935 rcv->pkt->len = offs; 951 rcv->pkt->len = offs;
936 memcpy (rcv->pkt->at (0), pkt.at (0), offs); 952 memcpy (rcv->pkt->at (0), pkt.at (0), offs);
937 } 953 }
954 }
938 955
939 duplicate_request: ; 956 duplicate_request: ;
940 } 957 }
941 else 958 else
942 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR); 959 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR);
… …
954 pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class 971 pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
955 pkt [offs++] = 0; pkt [offs++] = 0; 972 pkt [offs++] = 0; pkt [offs++] = 0;
956 pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL 973 pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL
957 pkt [offs++] = 0; pkt [offs++] = 4; // rdlength 974 pkt [offs++] = 0; pkt [offs++] = 4; // rdlength
958 975
959 slog (L_INFO, _("DNS: client %d tries to connect"), client); 976 slog (L_INFO, _("DNS: client %d connects"), client);
960 977
961 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3; 978 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
962 pkt [offs++] = CMD_IP_REJ; 979 pkt [offs++] = CMD_IP_REJ;
963 980
964 if (0 < client && client <= conns.size ()) 981 if (0 < client && client <= conns.size ())
… …
1007 if (dns->send_interval > MAX_SEND_INTERVAL) 1024 if (dns->send_interval > MAX_SEND_INTERVAL)
1008 dns->send_interval = MAX_SEND_INTERVAL; 1025 dns->send_interval = MAX_SEND_INTERVAL;
1009 } 1026 }
1010 else 1027 else
1011 { 1028 {
1012#if 1 1029#if 0
1013 dns->send_interval *= 0.999; 1030 dns->send_interval *= 0.999;
1014#endif 1031#endif
1015 if (dns->send_interval < MIN_SEND_INTERVAL)
1016 dns->send_interval = MIN_SEND_INTERVAL;
1017
1018 // the latency surely puts an upper bound on 1032 // the latency surely puts an upper bound on
1019 // the minimum send interval 1033 // the minimum send interval
1020 double latency = NOW - (*i)->sent; 1034 double latency = NOW - (*i)->sent;
1035
1036 if (latency < dns->min_latency)
1021 dns->last_latency = latency; 1037 dns->min_latency = latency;
1022 1038
1023 if (dns->send_interval > latency) 1039 if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor)
1040 dns->send_interval = dns->min_latency * conf.dns_overlap_factor;
1041
1042 if (dns->send_interval < conf.dns_send_interval)
1024 dns->send_interval = latency; 1043 dns->send_interval = conf.dns_send_interval;
1025 } 1044 }
1026 1045
1027 delete *i; 1046 delete *i;
1028 dns_sndpq.erase (i); 1047 dns_sndpq.erase (i);
1029 1048
… …
1146 1165
1147 pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len); 1166 pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len);
1148 1167
1149 if (pkt->len > 0) 1168 if (pkt->len > 0)
1150 { 1169 {
1151 if (THISNODE->dns_port) 1170 if (ntohs (pkt->flags) & FLAG_RESPONSE)
1171 dnsv4_client (*pkt);
1172 else
1152 { 1173 {
1153 dnsv4_server (*pkt); 1174 dnsv4_server (*pkt);
1154 sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len); 1175 sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len);
1155 } 1176 }
1156 else
1157 dnsv4_client (*pkt);
1158 1177
1159 delete pkt; 1178 delete pkt;
1160 } 1179 }
1161 } 1180 }
1162} 1181}
1163 1182
1164bool 1183bool
1165vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) 1184vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
1166{ 1185{
1167 int client = ntohs (si.port); 1186 int client = ntohl (si.host);
1168 1187
1169 assert (0 < client && client <= conns.size ()); 1188 assert (0 < client && client <= conns.size ());
1170 1189
1171 connection *c = conns [client - 1]; 1190 connection *c = conns [client - 1];
1172 1191
1173 if (!c->dns) 1192 if (!c->dns)
1174 c->dns = new dns_connection (c); 1193 c->dns = new dns_connection (c);
1175 1194
1176 if (!c->dns->snddq.put (pkt)) 1195 if (c->dns->snddq.put (pkt))
1177 return false;
1178
1179 c->dns->tw.trigger (); 1196 c->dns->tw.trigger ();
1180 1197
1198 // always return true even if the buffer overflows
1181 return true; 1199 return true;
1182} 1200}
1183 1201
1184void 1202void
1185connection::dnsv4_reset_connection () 1203connection::dnsv4_reset_connection ()
… …
1211 if (!send) 1229 if (!send)
1212 { 1230 {
1213 send = r; 1231 send = r;
1214 1232
1215 r->retry++; 1233 r->retry++;
1216 r->timeout = NOW + (r->retry * last_latency * 8.); 1234 r->timeout = NOW + (r->retry * min_latency * conf.dns_timeout_factor);
1217 1235
1218 // the following code changes the query section a bit, forcing 1236 // the following code changes the query section a bit, forcing
1219 // the forwarder to generate a new request 1237 // the forwarder to generate a new request
1220 if (r->stdhdr) 1238 if (r->stdhdr)
1221 { 1239 {
1222 //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); 1240 //printf ("reencoded header for ID %d retry %d:%d:%d (%p)\n", htons (r->pkt->id), THISNODE->id, r->seqno, r->retry);
1223 //encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry); 1241 //encode_header ((char *)r->pkt->at (6 * 2 + 1), THISNODE->id, r->seqno, r->retry);
1224 } 1242 }
1225 } 1243 }
1226 } 1244 }
1227 else 1245 else
1228 NEXT (r->timeout); 1246 NEXT (r->timeout);
1229 } 1247 }
1230 1248
1231 if (last_sent + send_interval <= NOW)
1232 {
1233 if (!send) 1249 if (!send)
1250 {
1251 // generate a new packet, if wise
1252
1253 if (!established)
1234 { 1254 {
1235 // generate a new packet, if wise 1255 if (vpn->dns_sndpq.empty ())
1236
1237 if (!established)
1238 { 1256 {
1239 if (vpn->dns_sndpq.empty ())
1240 {
1241 send = new dns_snd (this); 1257 send = new dns_snd (this);
1242 1258
1243 printf ("new conn %p %d\n", this, c->conf->id);//D
1244 cfg.reset (THISNODE->id); 1259 cfg.reset (THISNODE->id);
1245 send->gen_syn_req (); 1260 send->gen_syn_req ();
1246 }
1247 } 1261 }
1248 else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING 1262 }
1263 else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding
1249 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) 1264 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
1265 {
1266 if (last_sent + send_interval <= NOW)
1250 { 1267 {
1251 //printf ("sending data request etc.\n"); //D 1268 //printf ("sending data request etc.\n"); //D
1252 if (!snddq.empty ()) 1269 if (!snddq.empty () || last_received + 1. > NOW)
1253 { 1270 {
1254 poll_interval = send_interval; 1271 poll_interval = send_interval;
1255 NEXT (NOW + send_interval); 1272 NEXT (NOW + send_interval);
1256 } 1273 }
1257 1274
1258 send = new dns_snd (this); 1275 send = new dns_snd (this);
1259 send->gen_stream_req (sndseq, snddq); 1276 send->gen_stream_req (sndseq, snddq);
1260 send->timeout = NOW + last_latency * 8.; 1277 send->timeout = NOW + min_latency * conf.dns_timeout_factor;
1261 1278
1262 sndseq = (sndseq + 1) & SEQNO_MASK; 1279 sndseq = (sndseq + 1) & SEQNO_MASK;
1263 } 1280 }
1264 1281 else
1265 if (send) 1282 NEXT (last_sent + send_interval);
1266 vpn->dns_sndpq.push_back (send);
1267 } 1283 }
1268 1284
1269 if (send) 1285 if (send)
1270 { 1286 vpn->dns_sndpq.push_back (send);
1287 }
1288
1289 if (send)
1290 {
1271 last_sent = NOW; 1291 last_sent = NOW;
1272 sendto (vpn->dnsv4_fd, 1292 sendto (vpn->dnsv4_fd,
1273 send->pkt->at (0), send->pkt->len, 0, 1293 send->pkt->at (0), send->pkt->len, 0,
1274 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); 1294 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
1275 }
1276 } 1295 }
1277 else
1278 NEXT (last_sent + send_interval);
1279 1296
1280 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)",
1281 poll_interval, send_interval, next - NOW, 1298 poll_interval, send_interval, next - NOW,
1282 vpn->dns_sndpq.size (), snddq.size ()); 1299 vpn->dns_sndpq.size (), snddq.size (),
1300 rcvpq.size ());
1283 1301
1284 // 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
1303 // doesn't seem to happen anymore
1285 if (next < NOW + 0.0001) 1304 if (next < NOW + 0.001)
1286 next = NOW + 0.1; 1305 next = NOW + 0.1;
1287 1306
1288 w.start (next); 1307 w.start (next);
1289} 1308}
1290 1309

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