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/cvs/gvpe/src/vpn_dns.C
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Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.37 by pcg, Wed Mar 23 17:03:58 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
… …
457 r4 = r5 = r6 = r7 = 0; 461 r4 = r5 = r6 = r7 = 0;
458} 462}
459 463
460bool dns_cfg::valid () 464bool dns_cfg::valid ()
461{ 465{
466 // although the protocol itself allows for some configurability,
467 // only the following encoding/decoding settings are implemented.
462 return id1 == 'G' 468 return id1 == 'G'
463 && id2 == 'V' 469 && id2 == 'V'
464 && id3 == 'P' 470 && id3 == 'P'
465 && id4 == 'E' 471 && id4 == 'E'
466 && seq_cdc == 26 472 && seq_cdc == 26
… …
553 vector<dns_rcv *> rcvpq; 559 vector<dns_rcv *> rcvpq;
554 560
555 byte_stream rcvdq; int rcvseq; int repseq; 561 byte_stream rcvdq; int rcvseq; int repseq;
556 byte_stream snddq; int sndseq; 562 byte_stream snddq; int sndseq;
557 563
558 void time_cb (time_watcher &w); time_watcher tw; 564 void time_cb (ev::timer &w, int revents); ev::timer tw;
559 void receive_rep (dns_rcv *r); 565 void receive_rep (dns_rcv *r);
560 566
561 dns_connection (connection *c); 567 dns_connection (connection *c);
562 ~dns_connection (); 568 ~dns_connection ();
563}; 569};
… …
582: dns (dns) 588: dns (dns)
583{ 589{
584 timeout = 0; 590 timeout = 0;
585 retry = 0; 591 retry = 0;
586 seqno = 0; 592 seqno = 0;
587 sent = NOW; 593 sent = ev::ev_now ();
588 stdhdr = false; 594 stdhdr = false;
589 595
590 pkt = new dns_packet; 596 pkt = new dns_packet;
591 597
592 pkt->id = next_id (); 598 pkt->id = next_id ();
… …
623void dns_snd::gen_stream_req (int seqno, byte_stream &stream) 629void dns_snd::gen_stream_req (int seqno, byte_stream &stream)
624{ 630{
625 stdhdr = true; 631 stdhdr = true;
626 this->seqno = seqno; 632 this->seqno = seqno;
627 633
628 timeout = NOW + INITIAL_TIMEOUT; 634 timeout = ev::ev_now () + INITIAL_TIMEOUT;
629 635
630 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 636 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
631 pkt->qdcount = htons (1); 637 pkt->qdcount = htons (1);
632 638
633 int offs = 6*2; 639 int offs = 6*2;
… …
668 pkt->len = offs; 674 pkt->len = offs;
669} 675}
670 676
671void dns_snd::gen_syn_req () 677void dns_snd::gen_syn_req ()
672{ 678{
673 timeout = NOW + INITIAL_SYN_TIMEOUT; 679 timeout = ev::ev_now () + INITIAL_SYN_TIMEOUT;
674 680
675 pkt->flags = htons (DEFAULT_CLIENT_FLAGS); 681 pkt->flags = htons (DEFAULT_CLIENT_FLAGS);
676 pkt->qdcount = htons (1); 682 pkt->qdcount = htons (1);
677 683
678 int offs = 6 * 2; 684 int offs = 6 * 2;
… …
744 750
745void dns_connection::receive_rep (dns_rcv *r) 751void dns_connection::receive_rep (dns_rcv *r)
746{ 752{
747 if (r->datalen) 753 if (r->datalen)
748 { 754 {
749 last_received = NOW; 755 last_received = ev::ev_now ();
750 tw.trigger (); 756 tw ();
751 757
752 poll_interval = send_interval; 758 poll_interval = send_interval;
753 } 759 }
754 else 760 else
755 { 761 {
… …
765 771
766 // find next packet 772 // find next packet
767 for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); ) 773 for (vector<dns_rcv *>::iterator i = rcvpq.end (); i-- != rcvpq.begin (); )
768 if (SEQNO_EQ (rcvseq, (*i)->seqno)) 774 if (SEQNO_EQ (rcvseq, (*i)->seqno))
769 { 775 {
776 //printf ("seqno eq %x %x\n", rcvseq, (*i)->seqno);//D
770 // enter the packet into our input stream 777 // enter the packet into our input stream
771 r = *i; 778 r = *i;
772 779
773 // remove the oldest packet, look forward, as it's oldest first 780 // remove the oldest packet, look forward, as it's oldest first
774 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)
775 if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW)) 782 if (SEQNO_EQ ((*j)->seqno, rcvseq - MAX_WINDOW))
776 { 783 {
784 //printf ("seqno RR %x %x\n", (*j)->seqno, rcvseq - MAX_WINDOW);//D
777 delete *j; 785 delete *j;
778 rcvpq.erase (j); 786 rcvpq.erase (j);
779 break; 787 break;
780 } 788 }
781 789
… …
1009 { 1017 {
1010 dns_connection *dns = (*i)->dns; 1018 dns_connection *dns = (*i)->dns;
1011 connection *c = dns->c; 1019 connection *c = dns->c;
1012 int seqno = (*i)->seqno; 1020 int seqno = (*i)->seqno;
1013 u8 data[MAXSIZE], *datap = data; 1021 u8 data[MAXSIZE], *datap = data;
1022 //printf ("rcv pkt %x\n", seqno);//D
1014 1023
1015 if ((*i)->retry) 1024 if ((*i)->retry)
1016 { 1025 {
1017 dns->send_interval *= 1.01; 1026 dns->send_interval *= 1.01;
1018 if (dns->send_interval > MAX_SEND_INTERVAL) 1027 if (dns->send_interval > MAX_SEND_INTERVAL)
… …
1023#if 0 1032#if 0
1024 dns->send_interval *= 0.999; 1033 dns->send_interval *= 0.999;
1025#endif 1034#endif
1026 // the latency surely puts an upper bound on 1035 // the latency surely puts an upper bound on
1027 // the minimum send interval 1036 // the minimum send interval
1028 double latency = NOW - (*i)->sent; 1037 double latency = ev::ev_now () - (*i)->sent;
1029 1038
1030 if (latency < dns->min_latency) 1039 if (latency < dns->min_latency)
1031 dns->min_latency = latency; 1040 dns->min_latency = latency;
1032 1041
1033 if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor) 1042 if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor)
… …
1147 break; 1156 break;
1148 } 1157 }
1149} 1158}
1150 1159
1151void 1160void
1152vpn::dnsv4_ev (io_watcher &w, short revents) 1161vpn::dnsv4_ev (ev::io &w, int revents)
1153{ 1162{
1154 if (revents & EVENT_READ) 1163 if (revents & EV_READ)
1155 { 1164 {
1156 dns_packet *pkt = new dns_packet; 1165 dns_packet *pkt = new dns_packet;
1157 struct sockaddr_in sa; 1166 struct sockaddr_in sa;
1158 socklen_t sa_len = sizeof (sa); 1167 socklen_t sa_len = sizeof (sa);
1159 1168
… …
1185 1194
1186 if (!c->dns) 1195 if (!c->dns)
1187 c->dns = new dns_connection (c); 1196 c->dns = new dns_connection (c);
1188 1197
1189 if (c->dns->snddq.put (pkt)) 1198 if (c->dns->snddq.put (pkt))
1190 c->dns->tw.trigger (); 1199 c->dns->tw ();
1191 1200
1192 // always return true even if the buffer overflows 1201 // always return true even if the buffer overflows
1193 return true; 1202 return true;
1194} 1203}
1195 1204
… …
1200} 1209}
1201 1210
1202#define NEXT(w) do { if (next > (w)) next = w; } while (0) 1211#define NEXT(w) do { if (next > (w)) next = w; } while (0)
1203 1212
1204void 1213void
1205dns_connection::time_cb (time_watcher &w) 1214dns_connection::time_cb (ev::timer &w, int revents)
1206{ 1215{
1207 // servers have to be polled 1216 // servers have to be polled
1208 if (THISNODE->dns_port) 1217 if (THISNODE->dns_port)
1209 return; 1218 return;
1210 1219
1211 // check for timeouts and (re)transmit 1220 // check for timeouts and (re)transmit
1212 tstamp next = NOW + poll_interval; 1221 tstamp next = ev::now () + poll_interval;
1213 dns_snd *send = 0; 1222 dns_snd *send = 0;
1214 1223
1215 for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin (); 1224 for (vector<dns_snd *>::iterator i = vpn->dns_sndpq.begin ();
1216 i != vpn->dns_sndpq.end (); 1225 i != vpn->dns_sndpq.end ();
1217 ++i) 1226 ++i)
1218 { 1227 {
1219 dns_snd *r = *i; 1228 dns_snd *r = *i;
1220 1229
1221 if (r->timeout <= NOW) 1230 if (r->timeout <= ev::ev_now ())
1222 { 1231 {
1223 if (!send) 1232 if (!send)
1224 { 1233 {
1225 send = r; 1234 send = r;
1226 1235
1227 r->retry++; 1236 r->retry++;
1228 r->timeout = NOW + (r->retry * min_latency * conf.dns_timeout_factor); 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
1229 1239
1230 // the following code changes the query section a bit, forcing 1240 // the following code changes the query section a bit, forcing
1231 // the forwarder to generate a new request 1241 // the forwarder to generate a new request
1232 if (r->stdhdr) 1242 if (r->stdhdr)
1233 {
1234 //printf ("reencoded header for ID %d retry %d:%d:%d (%p)\n", htons (r->pkt->id), THISNODE->id, r->seqno, r->retry);
1235 //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);
1236 }
1237 } 1244 }
1238 } 1245 }
1239 else 1246 else
1240 NEXT (r->timeout); 1247 NEXT (r->timeout);
1241 } 1248 }
… …
1255 } 1262 }
1256 } 1263 }
1257 else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding 1264 else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding
1258 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) 1265 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
1259 { 1266 {
1260 if (last_sent + send_interval <= NOW) 1267 if (last_sent + send_interval <= ev::ev_now ())
1261 { 1268 {
1262 //printf ("sending data request etc.\n"); //D 1269 //printf ("sending data request etc.\n"); //D
1263 if (!snddq.empty () || last_received + 1. > NOW) 1270 if (!snddq.empty () || last_received + 1. > ev::ev_now ())
1264 { 1271 {
1265 poll_interval = send_interval; 1272 poll_interval = send_interval;
1266 NEXT (NOW + send_interval); 1273 NEXT (ev::ev_now () + send_interval);
1267 } 1274 }
1268 1275
1269 send = new dns_snd (this); 1276 send = new dns_snd (this);
1270 send->gen_stream_req (sndseq, snddq); 1277 send->gen_stream_req (sndseq, snddq);
1271 send->timeout = NOW + min_latency * conf.dns_timeout_factor; 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
1272 1280
1273 sndseq = (sndseq + 1) & SEQNO_MASK; 1281 sndseq = (sndseq + 1) & SEQNO_MASK;
1274 } 1282 }
1275 else 1283 else
1276 NEXT (last_sent + send_interval); 1284 NEXT (last_sent + send_interval);
… …
1280 vpn->dns_sndpq.push_back (send); 1288 vpn->dns_sndpq.push_back (send);
1281 } 1289 }
1282 1290
1283 if (send) 1291 if (send)
1284 { 1292 {
1285 last_sent = NOW; 1293 last_sent = ev::ev_now ();
1286 sendto (vpn->dnsv4_fd, 1294 sendto (vpn->dnsv4_fd,
1287 send->pkt->at (0), send->pkt->len, 0, 1295 send->pkt->at (0), send->pkt->len, 0,
1288 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); 1296 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
1289 } 1297 }
1290 1298
1291 slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)", 1299 slog (L_NOISE, "DNS: pi %f si %f N %f (%d:%d %d)",
1292 poll_interval, send_interval, next - NOW, 1300 poll_interval, send_interval, next - ev::ev_now (),
1293 vpn->dns_sndpq.size (), snddq.size (), 1301 vpn->dns_sndpq.size (), snddq.size (),
1294 rcvpq.size ()); 1302 rcvpq.size ());
1295 1303
1296 // 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
1297 // doesn't seem to happen anymore 1305 // doesn't seem to happen anymore
1298 if (next < NOW + 0.001) 1306 if (next < ev::ev_now () + 0.001)
1299 next = NOW + 0.1; 1307 next = ev::ev_now () + 0.1;
1300 1308
1301 w.start (next); 1309 w.start (next - ev::ev_now ());
1302} 1310}
1303 1311
1304#endif 1312#endif
1305 1313

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