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/cvs/gvpe/src/vpn_dns.C
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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 1.24 by pcg, Mon Mar 7 01:31:26 2005 UTC

… …
265static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO"); 265static basecoder cdc26 ("dPhZrQmJkBtSvLxAeFwGyO");
266 266
267///////////////////////////////////////////////////////////////////////////// 267/////////////////////////////////////////////////////////////////////////////
268 268
269#define HDRSIZE 6 269#define HDRSIZE 6
270 270
271inline void encode_header (char *data, int clientid, int seqno, int retry = 0) 271inline void encode_header (char *data, int clientid, int seqno, int retry = 0)
272{ 272{
273 seqno &= SEQNO_MASK; 273 seqno &= SEQNO_MASK;
274 274
275 u8 hdr[3] = { 275 u8 hdr[3] = {
… …
409struct dns_cfg 409struct dns_cfg
410{ 410{
411 static int next_uid; 411 static int next_uid;
412 412
413 u8 id1, id2, id3, id4; 413 u8 id1, id2, id3, id4;
414
414 u8 version; 415 u8 version;
416 u8 flags;
415 u8 rrtype; 417 u8 rrtype;
416 u8 flags;
417 u8 def_ttl; 418 u8 def_ttl;
418 u8 rcv_cdc; 419
419 u8 snd_cdc;
420 u16 max_size;
421 u16 client; 420 u16 client;
422 u16 uid; // to make request unique 421 u16 uid; // to make request unique
423 422
424 u8 reserved[8]; 423 u16 max_size;
424 u8 seq_cdc;
425 u8 req_cdc;
426
427 u8 rep_cdc;
428 u8 r2, r3, r4;
429
430 u8 r5, r6, r7, r8;
425 431
426 void reset (int clientid); 432 void reset (int clientid);
427 bool valid (); 433 bool valid ();
428}; 434};
429 435
… …
438 444
439 version = 1; 445 version = 1;
440 446
441 rrtype = RR_TYPE_TXT; 447 rrtype = RR_TYPE_TXT;
442 flags = 0; 448 flags = 0;
443 def_ttl = 1; 449 def_ttl = 0;
450 seq_cdc = 26;
451 req_cdc = 62;
444 rcv_cdc = 0; 452 rep_cdc = 0;
445 snd_cdc = 62;
446 max_size = ntohs (MAX_PKT_SIZE); 453 max_size = ntohs (MAX_PKT_SIZE);
447 client = ntohs (clientid); 454 client = ntohs (clientid);
448 uid = next_uid++; 455 uid = next_uid++;
449 456
450 memset (reserved, 0, 8); 457 r2 = r3 = r4 = 0;
458 r4 = r5 = r6 = r7 = 0;
451} 459}
452 460
453bool dns_cfg::valid () 461bool dns_cfg::valid ()
454{ 462{
455 return id1 == 'G' 463 return id1 == 'G'
456 && id2 == 'V' 464 && id2 == 'V'
457 && id3 == 'P' 465 && id3 == 'P'
458 && id4 == 'E' 466 && id4 == 'E'
467 && seq_cdc == 26
468 && req_cdc == 62
469 && rep_cdc == 0
459 && version == 1 470 && version == 1
460 && flags == 0
461 && rcv_cdc == 0
462 && snd_cdc == 62
463 && max_size == ntohs (MAX_PKT_SIZE); 471 && max_size == ntohs (MAX_PKT_SIZE);
464} 472}
465 473
466struct dns_packet : net_packet 474struct dns_packet : net_packet
467{ 475{
468 u16 id; 476 u16 id;
469 u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4 477 u16 flags; // QR:1 Opcode:4 AA:1 TC:1 RD:1 RA:1 Z:3 RCODE:4
470 u16 qdcount, ancount, nscount, arcount; 478 u16 qdcount, ancount, nscount, arcount;
471 479
472 u8 data[MAXSIZE - 6 * 2]; 480 u8 data [MAXSIZE - 6 * 2];
473 481
474 int decode_label (char *data, int size, int &offs); 482 int decode_label (char *data, int size, int &offs);
475}; 483};
476 484
477int dns_packet::decode_label (char *data, int size, int &offs) 485int dns_packet::decode_label (char *data, int size, int &offs)
… …
663} 671}
664 672
665void dns_snd::gen_syn_req () 673void dns_snd::gen_syn_req ()
666{ 674{
667 timeout = NOW + INITIAL_SYN_TIMEOUT; 675 timeout = NOW + INITIAL_SYN_TIMEOUT;
668
669 printf ("send syn\n");//D
670 676
671 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 677 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
672 pkt->qdcount = htons (1); 678 pkt->qdcount = htons (1);
673 679
674 int offs = 6 * 2; 680 int offs = 6 * 2;
… …
807 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR); 813 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR);
808 814
809 if (0 == (flags & (FLAG_RESPONSE | FLAG_OP_MASK)) 815 if (0 == (flags & (FLAG_RESPONSE | FLAG_OP_MASK))
810 && pkt.qdcount == htons (1)) 816 && pkt.qdcount == htons (1))
811 { 817 {
812 char qname[MAXSIZE]; 818 char qname [MAXSIZE];
813 int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs); 819 int qlen = pkt.decode_label ((char *)qname, MAXSIZE - offs, offs);
814 820
815 u16 qtype = pkt [offs++] << 8; qtype |= pkt [offs++]; 821 u16 qtype = pkt [offs++] << 8; qtype |= pkt [offs++];
816 u16 qclass = pkt [offs++] << 8; qclass |= pkt [offs++]; 822 u16 qclass = pkt [offs++] << 8; qclass |= pkt [offs++];
817 823
… …
824 830
825 int dlen = strlen (THISNODE->domain); 831 int dlen = strlen (THISNODE->domain);
826 832
827 if (qclass == RR_CLASS_IN 833 if (qclass == RR_CLASS_IN
828 && qlen > dlen + 1 834 && qlen > dlen + 1
829 && !memcmp (qname + qlen - dlen - 1, THISNODE->domain, dlen)) 835 && !memcmp (qname + qlen - (dlen + 1), THISNODE->domain, dlen))
830 { 836 {
831 // now generate reply 837 // now generate reply
832 pkt.ancount = htons (1); // one answer RR 838 pkt.ancount = htons (1); // one answer RR
833 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_OK); 839 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_OK);
834 840
… …
875 // new packet, queue 881 // new packet, queue
876 rcv = new dns_rcv (seqno, data, datalen); 882 rcv = new dns_rcv (seqno, data, datalen);
877 dns->receive_rep (rcv); 883 dns->receive_rep (rcv);
878 } 884 }
879 885
886 {
880 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
881 888
882 int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A; 889 int rtype = dns ? dns->cfg.rrtype : RR_TYPE_A;
883 pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type 890 pkt [offs++] = rtype >> 8; pkt [offs++] = rtype; // type
884 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
885 pkt [offs++] = 0; pkt [offs++] = 0; 892 pkt [offs++] = 0; pkt [offs++] = 0;
886 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
887 894
888 int rdlen_offs = offs += 2; 895 int rdlen_offs = offs += 2;
889 896
890 int dlen = (dns ? ntohs (dns->cfg.max_size) : MAX_PKT_SIZE) - offs; 897 int dlen = (dns ? ntohs (dns->cfg.max_size) : MAX_PKT_SIZE) - offs;
891 // bind doesn't compress well, so reduce further by one label length 898 // bind doesn't compress well, so reduce further by one label length
892 dlen -= qlen; 899 dlen -= qlen;
893 900
894 if (dns) 901 if (dns)
895 { 902 {
896 // only put data into in-order sequence packets, if 903 // only put data into in-order sequence packets, if
897 // we receive out-of-order packets we generate empty 904 // we receive out-of-order packets we generate empty
898 // replies 905 // replies
899 while (dlen > 1 && !dns->snddq.empty () && in_seq) 906 while (dlen > 1 && !dns->snddq.empty () && in_seq)
900 { 907 {
901 int txtlen = dlen <= 255 ? dlen - 1 : 255; 908 int txtlen = dlen <= 255 ? dlen - 1 : 255;
902 909
903 if (txtlen > dns->snddq.size ()) 910 if (txtlen > dns->snddq.size ())
904 txtlen = dns->snddq.size (); 911 txtlen = dns->snddq.size ();
905 912
906 pkt[offs++] = txtlen; 913 pkt[offs++] = txtlen;
907 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen); 914 memcpy (pkt.at (offs), dns->snddq.begin (), txtlen);
908 offs += txtlen; 915 offs += txtlen;
909 dns->snddq.remove (txtlen); 916 dns->snddq.remove (txtlen);
910 917
911 dlen -= txtlen + 1; 918 dlen -= txtlen + 1;
912 } 919 }
913 920
914 // avoid empty TXT rdata 921 // avoid empty TXT rdata
915 if (offs == rdlen_offs) 922 if (offs == rdlen_offs)
916 pkt[offs++] = 0; 923 pkt[offs++] = 0;
917 924
918 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ()); 925 slog (L_NOISE, "DNS: snddq %d", dns->snddq.size ());
919 } 926 }
920 else 927 else
921 { 928 {
922 // send RST 929 // send RST
923 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3; 930 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
924 pkt [offs++] = CMD_IP_RST; 931 pkt [offs++] = CMD_IP_RST;
925 } 932 }
926 933
927 int rdlen = offs - rdlen_offs; 934 int rdlen = offs - rdlen_offs;
928 935
929 pkt [rdlen_offs - 2] = rdlen >> 8; 936 pkt [rdlen_offs - 2] = rdlen >> 8;
930 pkt [rdlen_offs - 1] = rdlen; 937 pkt [rdlen_offs - 1] = rdlen;
931 938
932 if (dns) 939 if (dns)
933 { 940 {
934 // now update dns_rcv copy 941 // now update dns_rcv copy
935 rcv->pkt->len = offs; 942 rcv->pkt->len = offs;
936 memcpy (rcv->pkt->at (0), pkt.at (0), offs); 943 memcpy (rcv->pkt->at (0), pkt.at (0), offs);
937 } 944 }
945 }
938 946
939 duplicate_request: ; 947 duplicate_request: ;
940 } 948 }
941 else 949 else
942 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR); 950 pkt.flags = htons (DEFAULT_SERVER_FLAGS | FLAG_RCODE_FORMERR);
… …
954 pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class 962 pkt [offs++] = RR_CLASS_IN >> 8; pkt [offs++] = RR_CLASS_IN; // class
955 pkt [offs++] = 0; pkt [offs++] = 0; 963 pkt [offs++] = 0; pkt [offs++] = 0;
956 pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL 964 pkt [offs++] = 0; pkt [offs++] = cfg.def_ttl; // TTL
957 pkt [offs++] = 0; pkt [offs++] = 4; // rdlength 965 pkt [offs++] = 0; pkt [offs++] = 4; // rdlength
958 966
959 slog (L_INFO, _("DNS: client %d tries to connect"), client); 967 slog (L_INFO, _("DNS: client %d connects"), client);
960 968
961 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3; 969 pkt [offs++] = CMD_IP_1; pkt [offs++] = CMD_IP_2; pkt [offs++] = CMD_IP_3;
962 pkt [offs++] = CMD_IP_REJ; 970 pkt [offs++] = CMD_IP_REJ;
963 971
964 if (0 < client && client <= conns.size ()) 972 if (0 < client && client <= conns.size ())
… …
1146 1154
1147 pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len); 1155 pkt->len = recvfrom (w.fd, pkt->at (0), MAXSIZE, 0, (sockaddr *)&sa, &sa_len);
1148 1156
1149 if (pkt->len > 0) 1157 if (pkt->len > 0)
1150 { 1158 {
1151 if (THISNODE->dns_port) 1159 if (ntohs (pkt->flags) & FLAG_RESPONSE)
1160 dnsv4_client (*pkt);
1161 else
1152 { 1162 {
1153 dnsv4_server (*pkt); 1163 dnsv4_server (*pkt);
1154 sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len); 1164 sendto (w.fd, pkt->at (0), pkt->len, 0, (sockaddr *)&sa, sa_len);
1155 } 1165 }
1156 else
1157 dnsv4_client (*pkt);
1158 1166
1159 delete pkt; 1167 delete pkt;
1160 } 1168 }
1161 } 1169 }
1162} 1170}
… …
1238 { 1246 {
1239 if (vpn->dns_sndpq.empty ()) 1247 if (vpn->dns_sndpq.empty ())
1240 { 1248 {
1241 send = new dns_snd (this); 1249 send = new dns_snd (this);
1242 1250
1243 printf ("new conn %p %d\n", this, c->conf->id);//D
1244 cfg.reset (THISNODE->id); 1251 cfg.reset (THISNODE->id);
1245 send->gen_syn_req (); 1252 send->gen_syn_req ();
1246 } 1253 }
1247 } 1254 }
1248 else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING 1255 else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING

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