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/cvs/gvpe/src/vpn_dns.C
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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 1.22 by pcg, Sun Mar 6 21:47:35 2005 UTC

… …
25 25
26// dns processing is EXTREMELY ugly. For obvious(?) reasons. 26// dns processing is EXTREMELY ugly. For obvious(?) reasons.
27// it's a hack, use only in emergency situations please. 27// it's a hack, use only in emergency situations please.
28 28
29#include <cstring> 29#include <cstring>
30#include <cassert>
30 31
31#include <sys/types.h> 32#include <sys/types.h>
32#include <sys/socket.h> 33#include <sys/socket.h>
33#include <sys/wait.h> 34#include <sys/wait.h>
34#include <sys/uio.h> 35#include <sys/uio.h>
… …
663 664
664void dns_snd::gen_syn_req () 665void dns_snd::gen_syn_req ()
665{ 666{
666 timeout = NOW + INITIAL_SYN_TIMEOUT; 667 timeout = NOW + INITIAL_SYN_TIMEOUT;
667 668
668 printf ("send syn\n");//D
669
670 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 669 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
671 pkt->qdcount = htons (1); 670 pkt->qdcount = htons (1);
672 671
673 int offs = 6 * 2; 672 int offs = 6 * 2;
674 673
… …
874 // new packet, queue 873 // new packet, queue
875 rcv = new dns_rcv (seqno, data, datalen); 874 rcv = new dns_rcv (seqno, data, datalen);
876 dns->receive_rep (rcv); 875 dns->receive_rep (rcv);
877 } 876 }
878 877
878 {
879 pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section 879 pkt [offs++] = 0xc0; pkt [offs++] = 6 * 2; // refer to name in query section
880 880
881 int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A; 881 int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A;
882 pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type 882 pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type
883 pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class 883 pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
884 pkt [offs++] = 0; pkt [offs++] = 0; 884 pkt [offs++] = 0; pkt [offs++] = 0;
885 pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL 885 pkt [offs++] = 0; pkt [offs++] = dns ? dns->cfg.def_ttl : 0; // TTL
886 886
887 int rdlen_offs = offs += 2; 887 int rdlen_offs = offs += 2;
888 888
889 int dlen = (dns ? ntohs (dns->cfg.max_size) : MAX_PKT_SIZE) - offs; 889 int dlen = (dns ? ntohs (dns->cfg.max_size) : MAX_PKT_SIZE) - offs;
890 // bind doesn't compress well, so reduce further by one label length 890 // bind doesn't compress well, so reduce further by one label length
891 dlen -= qlen; 891 dlen -= qlen;
892 892
893 if (dns) 893 if (dns)
894 { 894 {
895 // only put data into in-order sequence packets, if 895 // only put data into in-order sequence packets, if
896 // we receive out-of-order packets we generate empty 896 // we receive out-of-order packets we generate empty
897 // replies 897 // replies
898 while (dlen > 1 && !dns->snddq.empty () && in_seq) 898 while (dlen > 1 && !dns->snddq.empty () && in_seq)
899 { 899 {
900 int txtlen = dlen <= 255 ? dlen - 1 : 255; 900 int txtlen = dlen <= 255 ? dlen - 1 : 255;
901 901
902 if (txtlen > dns->snddq.size ()) 902 if (txtlen > dns->snddq.size ())
903 txtlen = dns->snddq.size (); 903 txtlen = dns->snddq.size ();
904 904
905 pkt[offs++] = txtlen; 905 pkt[offs++] = txtlen;
906 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen); 906 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
907 offs += txtlen; 907 offs += txtlen;
908 dns->snddq.remove (txtlen); 908 dns->snddq.remove (txtlen);
909 909
910 dlen -= txtlen + 1; 910 dlen -= txtlen + 1;
911 } 911 }
912 912
913 // avoid empty TXT rdata 913 // avoid empty TXT rdata
914 if (offs == rdlen_offs) 914 if (offs == rdlen_offs)
915 pkt[offs++] = 0; 915 pkt[offs++] = 0;
916 916
917 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ()); 917 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
918 } 918 }
919 else 919 else
920 { 920 {
921 // send RST 921 // send RST
922 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3; 922 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
923 pkt [offs++] = CMD_IP_RST; 923 pkt [offs++] = CMD_IP_RST;
924 } 924 }
925 925
926 int rdlen = offs - rdlen_offs; 926 int rdlen = offs - rdlen_offs;
927 927
928 pkt [rdlen_offs - 2] = rdlen >> 8; 928 pkt [rdlen_offs - 2] = rdlen >> 8;
929 pkt [rdlen_offs - 1] = rdlen; 929 pkt [rdlen_offs - 1] = rdlen;
930 930
931 if (dns) 931 if (dns)
932 { 932 {
933 // now update dns_rcv copy 933 // now update dns_rcv copy
934 rcv->pkt->len = offs; 934 rcv->pkt->len = offs;
935 memcpy (rcv->pkt->at (0), pkt.at (0), offs); 935 memcpy (rcv->pkt->at (0), pkt.at (0), offs);
936 } 936 }
937 }
937 938
938 duplicate_request: ; 939 duplicate_request: ;
939 } 940 }
940 else 941 else
941 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR); 942 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR);

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