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/cvs/gvpe/src/vpn_dns.C
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Comparing gvpe/src/vpn_dns.C (file contents):
Revision 1.32 by pcg, Tue Mar 15 18:15:39 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
… …
47#include "vpn.h" 51#include "vpn.h"
48 52
49#define MAX_POLL_INTERVAL 5. // 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 TIMEOUT_FACTOR 4.
53
54#define INITIAL_TIMEOUT 0.1 // retry timeouts 56#define INITIAL_TIMEOUT 0.1 // retry timeouts
55#define INITIAL_SYN_TIMEOUT 10. // retry timeout for initial syn 57#define INITIAL_SYN_TIMEOUT 2. // retry timeout for initial syn
56 58
57#define MIN_SEND_INTERVAL 0.001 // wait at least this time between sending requests
58#define MAX_SEND_INTERVAL 2. // optimistic? 59#define MAX_SEND_INTERVAL 2. // optimistic?
59 60
60#define LATENCY_FACTOR 0.5 // RTT * LATENCY_FACTOR == sending rate
61#define MAX_OUTSTANDING 100 // max. outstanding requests
62#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog 61#define MAX_WINDOW 1000 // max. for MAX_OUTSTANDING, and backlog
63#define MAX_BACKLOG (32*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
64 63
65#define MAX_DOMAIN_SIZE 240 // 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
66// 240 leaves about 4 bytes of server reply data 65// 240 leaves about 4 bytes of server reply data
67// every two request bytes less give room for one reply byte 66// every request byte less give room for two reply bytes
68 67
69#define SEQNO_MASK 0x3fff 68#define SEQNO_MASK 0x3fff
70#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) ) 69#define SEQNO_EQ(a,b) ( 0 == ( ((a) ^ (b)) & SEQNO_MASK) )
71 70
72#define MAX_LBL_SIZE 63 71#define MAX_LBL_SIZE 63
… …
793 } 792 }
794 793
795 while (vpn_packet *pkt = rcvdq.get ()) 794 while (vpn_packet *pkt = rcvdq.get ())
796 { 795 {
797 sockinfo si; 796 sockinfo si;
798 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;
799 798
800 vpn->recv_vpn_packet (pkt, si); 799 vpn->recv_vpn_packet (pkt, si);
801 800
802 delete pkt; 801 delete pkt;
803 } 802 }
… …
1033 double latency = NOW - (*i)->sent; 1032 double latency = NOW - (*i)->sent;
1034 1033
1035 if (latency < dns->min_latency) 1034 if (latency < dns->min_latency)
1036 dns->min_latency = latency; 1035 dns->min_latency = latency;
1037 1036
1038 if (dns->send_interval > dns->min_latency * LATENCY_FACTOR) 1037 if (dns->send_interval > dns->min_latency * conf.dns_overlap_factor)
1039 dns->send_interval = dns->min_latency * LATENCY_FACTOR; 1038 dns->send_interval = dns->min_latency * conf.dns_overlap_factor;
1040 1039
1041 if (dns->send_interval < MIN_SEND_INTERVAL) 1040 if (dns->send_interval < conf.dns_send_interval)
1042 dns->send_interval = MIN_SEND_INTERVAL; 1041 dns->send_interval = conf.dns_send_interval;
1043 } 1042 }
1044 1043
1045 delete *i; 1044 delete *i;
1046 dns_sndpq.erase (i); 1045 dns_sndpq.erase (i);
1047 1046
… …
1180} 1179}
1181 1180
1182bool 1181bool
1183vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) 1182vpn::send_dnsv4_packet (vpn_packet *pkt, const sockinfo &si, int tos)
1184{ 1183{
1185 int client = ntohs (si.port); 1184 int client = ntohl (si.host);
1186 1185
1187 assert (0 < client && client <= conns.size ()); 1186 assert (0 < client && client <= conns.size ());
1188 1187
1189 connection *c = conns [client - 1]; 1188 connection *c = conns [client - 1];
1190 1189
… …
1228 if (!send) 1227 if (!send)
1229 { 1228 {
1230 send = r; 1229 send = r;
1231 1230
1232 r->retry++; 1231 r->retry++;
1233 r->timeout = NOW + (r->retry * min_latency * TIMEOUT_FACTOR); 1232 r->timeout = NOW + (r->retry * min_latency * conf.dns_timeout_factor);
1234 1233
1235 // the following code changes the query section a bit, forcing 1234 // the following code changes the query section a bit, forcing
1236 // the forwarder to generate a new request 1235 // the forwarder to generate a new request
1237 if (r->stdhdr) 1236 if (r->stdhdr)
1238 { 1237 {
… …
1257 1256
1258 cfg.reset (THISNODE->id); 1257 cfg.reset (THISNODE->id);
1259 send->gen_syn_req (); 1258 send->gen_syn_req ();
1260 } 1259 }
1261 } 1260 }
1262 else if (vpn->dns_sndpq.size () < MAX_OUTSTANDING 1261 else if (vpn->dns_sndpq.size () < conf.dns_max_outstanding
1263 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1))) 1262 && !SEQNO_EQ (rcvseq, sndseq - (MAX_WINDOW - 1)))
1264 { 1263 {
1265 if (last_sent + send_interval <= NOW) 1264 if (last_sent + send_interval <= NOW)
1266 { 1265 {
1267 //printf ("sending data request etc.\n"); //D 1266 //printf ("sending data request etc.\n"); //D
… …
1271 NEXT (NOW + send_interval); 1270 NEXT (NOW + send_interval);
1272 } 1271 }
1273 1272
1274 send = new dns_snd (this); 1273 send = new dns_snd (this);
1275 send->gen_stream_req (sndseq, snddq); 1274 send->gen_stream_req (sndseq, snddq);
1276 send->timeout = NOW + min_latency * TIMEOUT_FACTOR; 1275 send->timeout = NOW + min_latency * conf.dns_timeout_factor;
1277 1276
1278 sndseq = (sndseq + 1) & SEQNO_MASK; 1277 sndseq = (sndseq + 1) & SEQNO_MASK;
1279 } 1278 }
1280 else 1279 else
1281 NEXT (last_sent + send_interval); 1280 NEXT (last_sent + send_interval);
… …
1286 } 1285 }
1287 1286
1288 if (send) 1287 if (send)
1289 { 1288 {
1290 last_sent = NOW; 1289 last_sent = NOW;
1291 if (rand () & 15 != 0)//D
1292 sendto (vpn->dnsv4_fd, 1290 sendto (vpn->dnsv4_fd,
1293 send->pkt->at (0), send->pkt->len, 0, 1291 send->pkt->at (0), send->pkt->len, 0,
1294 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ()); 1292 vpn->dns_forwarder.sav4 (), vpn->dns_forwarder.salenv4 ());
1295 } 1293 }
1296 1294
… …
1298 poll_interval, send_interval, next - NOW, 1296 poll_interval, send_interval, next - NOW,
1299 vpn->dns_sndpq.size (), snddq.size (), 1297 vpn->dns_sndpq.size (), snddq.size (),
1300 rcvpq.size ()); 1298 rcvpq.size ());
1301 1299
1302 // 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
1303 if (next < NOW + 0.001) 1302 if (next < NOW + 0.001)
1304 next = NOW + 0.1; 1303 next = NOW + 0.1;
1305 1304
1306 w.start (next); 1305 w.start (next);
1307} 1306}

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