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psyced/world/net/circuit.c

333 lines
11 KiB
C

// vim:foldmethod=marker:syntax=lpc:noexpandtab
// $Id: circuit.c,v 1.107 2008/07/04 18:37:21 lynx Exp $
//
// net/circuit - generic circuit manager
//
// net/circuit implementiert ein protokollabstrahiertes management von
// psyc objekten hinter TCP verbindungen (oder anderen virtual circuit
// technologien, die wir aber vermutlich nie sehen werden), es versucht
// nach verlorener verbindung diese evtl wieder aufbauen, bzw baut die
// erste verbindung auf wenn ein objekt auf dem server eine wünscht.
// aus diesem grund führt es eine message queue für noch auszuliefernde
// nachrichten. sollte die verbindung nicht herstellbar sein wird es
// den unglücklichen sources eine fehlermeldung zurückschicken (mailer
// daemon lässt grüssen).
//
// also.. maybe one day this object will take care of _context
// optimizations.. just maybe.. maybe the places will do..
// local debug messages - turn them on by using psyclpc -DDcircuit=<level>
#ifdef Dcircuit
# undef DEBUG
# define DEBUG Dcircuit
#endif
#if defined(DEBUG) && DEBUG > 1
# define CONNECT_RETRY 2 // seconds for testing
#else
# define CONNECT_RETRY 8 // = 8+8+random(8) to start with
#endif
#ifndef MAX_RETRY
# define MAX_RETRY 3 // retry in 1 + 3 + 9 minutes
#endif
#include <net.h>
#include <dns.h>
inherit NET_PATH "connect";
volatile mixed me;
volatile string host;
volatile int port;
volatile int retry;
volatile int waitforme;
volatile int time_of_connect_attempt;
inherit NET_PATH "queue";
#if 0 //def PSYC_SYNCHRONIZE
# define ISSYNC issync
volatile int issync;
#else
# define ISSYNC 0
#endif
#ifndef ERQ_WITHOUT_SRV
string hostname; // original hostname
mixed *srv_hostlist;
int srv_index;
srv_choose(mixed *hostlist, string transport) {
string srvhost;
int srvport;
unless (pointerp(hostlist)) {
return connect(hostname, port, transport);
}
// choose a host according to prio/weight/bla
// actually, the dns resolver should already order them
// in a load balancing way
srvhost = hostlist[0][DNS_SRV_NAME];
srvport = hostlist[0][DNS_SRV_PORT];
if (srvhost == "") {
// no such service offered at this domain
// _xmpp-server._tcp.no.such.xmpptest.com. 1195 IN SRV 0 0 0 .
return connect_failure("_failure_unavailable_service",
"No service offered by domain " + hostname);
}
srv_hostlist = hostlist;
srv_index = 0;
// we use other srv records for fallback..
// saga thinks we can use quote and pass an array into the lambda,
// but it works this way, too -fippo
string extra = "";
for (int i = 1; i < sizeof(hostlist); i++) {
extra += hostlist[i][DNS_SRV_NAME] +":"+
((string) hostlist[i][DNS_SRV_PORT]) + ";";
}
return connect(srvhost, srvport, transport, 0, extra);
}
#else
# echo Warning: No SRV enabled. Will not be able to talk to jabber.ccc.de etc.
#endif
void reconnect() {
P0(("reconnect %O:%d\n", host, port))
if (ISSYNC || retry++ < MAX_RETRY) {
waitforme = waitforme * 2 + random(waitforme);
call_out(#'connect, waitforme);
P2(("%O trying to reconnect in %d secs\n", ME, waitforme))
return;
}
connect_failure("_repeated",
"Could not establish a circuit to "
+ host +":"+ port);
}
void pushback(string failmc) {
mixed *t, o;
mapping vars;
P2(("%O pushback of queue(%O) (size %O).\n", failmc, me, qSize(me)))
while(qSize(me) && (t = shift(me))) {
// is it okay to append pushback mc?
// or should we even append the mc of the respective message!?
string mc = "_failure_unsuccessful_delivery" + failmc;
P3(("failure... delivering queue(%O) back (%O to go). next: %O\n",
me, qSize(me), t))
// 0:source, 1:method, 2:data, 3:vars, 4:target
if (mappingp(t[3])) {
vars = t[3];
o = vars["_context"];
} else vars = ([]);
// is o || t[0] correct? the following can happen if
// we are using mcast:
// suppose we have some people from our host in a
// room on the remote server. If the connect fails
// we should notify them all that the communication
// is broken currently
// on the other hand, if this is used for persons
// it could possibly result something anti-privacy
//
// so do we want to search for a local handler of t[4] first?
if (t[1] == mc) {
// this happens when the place is stupid enough to
// castmsg the failure.
P1(("%O caught attempt to resend %O to %O || %O\n",
ME, mc, o, t[0]))
} else sendmsg(o || t[0], mc, // ok, should this message really
// have its original target as
// source, should _source be in
// the passed mapping vars
// additionaly to just being passed
// as source, and:
// rooms need to know ME for removing
// all users with this circuit from
// their mcast structueres, but is
// _INTERNAL_origin the correct
// name in this case (especially if
// we decide that source shouldn't
// be the original target)?
0, // "Could not establish a circuit to [_host] in order to deliver a [_method_relay] to [_source].",
([ "_method_relay": t[1],
"_data_relay" : t[2],
// we used to add the vars to the error message,
// but that causes a problem in places with nick
// apparently coming from a different source..
"_nick": vars["_nick_target"],
"_source": t[4],
"_host": host,
"_source_origin": SERVER_UNIFORM,
"_INTERNAL_origin" : ME,
// so that tag-operated queues can be rolled back
"_tag_reply" : t[3]["_tag"],
"_tag_relay" : t[3]["_tag"] || t[3]["_tag_reply"],
"_source_relay": t[0] || t[3]["_source"] ]), t[4]);
// + vars
}
// retry = 0;
// P2(("%O qDel(%O) and autodestruct\n", ME, me))
qDel(me); // not sure if this is necessary but looks safer
destruct(ME);
// alright. so this is where we want to do something
// differently, like remember that this host didn't work. TODO
}
// wouldn't it be nicer to also pass real vars here?
void connect_failure(string mc, string reason) {
::connect_failure(mc, reason);
if (abbrev("_attempt", mc)) {
#ifndef ERQ_WITHOUT_SRV
if (pointerp(srv_hostlist) && srv_index < sizeof(srv_hostlist)) {
srv_index++;
host = srv_hostlist[srv_index][DNS_SRV_NAME];
port = srv_hostlist[srv_index][DNS_SRV_PORT];
retry = 0;
waitforme = 0;
P0(("changing to srv target #%d: %O:%d\n", srv_index, host, port))
}
#endif
reconnect();
}
else pushback(mc);
}
int msg(string source, string method, string data,
mapping vars, int showingLog, mixed target) {
P1(("%O:msg() shouldn't get called. overload me!\n", ME))
return 0;
}
circuit(ho, po, transport, srv, whoami, sysQ, uniform) {
P2(("%O circuit(%O, %O, %O, %O)\n", ME, ho, po, transport, srv))
if (me) {
// happens apparently when a racing condition occurs
// during upgrade from xmpp to psyc.. hm! queue fails
// to deliver in that case and waits for next chance TODO
P1(("%O loaded twice for %O and %O\n", ME, me, whoami))
return ME;
}
q = mappingp(sysQ) ? sysQ : system_queue();
#if 0
unless(whoami) whoami = ME;
#else
unless(whoami) whoami = ho || ME;
#endif
qInit(me = whoami, 3303, 12);
D1( if (q[me]) PP(("%O using %O's queue: %O\n", ME, me, sizeof(q[me]) > 2 ? sizeof(q[me]) : q[me])); )
waitforme = CONNECT_RETRY;
retry = 0;
#if 0 //def PSYC_SYNCHRONIZE
issync = stringp(uniform) && abbrev(PSYC_SYNCHRONIZE, uniform);
D1( if (issync) PP(("The synchronizer, that's %O\n", uniform)); )
#endif
if (ho) connect(ho, po, transport, srv);
return ME;
}
// who needs this? who calls this? /rm and derivatives. shutdown() too.
// net/psyc/active because net/psyc/server has its own
quit() {
P2(("%O quit.\n", ME))
remove_interactive(ME);
//destruct(ME);
}
runQ() {
mixed *t, source;
D2(unless (me) raise_error("unitialized circuit\n");)
P3(( "%O runQ of size %O\n", ME, qSize(me)))
// causes an exception when q is too big
P4(( "%O\n", q))
while (qSize(me) && (t = shift(me))) {
// 0:source, 1:method, 2:data, 3:vars, 4:target
// revert to string source if the object has destructed
source = t[0] || t[3]["_source"];
msg(source, t[1], t[2], t[3], 0, t[4]);
#if 1
// <lynX> i need to know if this could ever happen, and if so
// if it is harmless anyhow. see below.
D1( if (member(t[3], "_source_relay") &&! t[3]["_source_relay"])
PP(("runQ in %O: lost _source_relay for %O from %O to %O\n",
ME, t[1], source, t[4])); )
#endif
}
retry = 0; // should we get disconnected restart from 8 seconds
waitforme = CONNECT_RETRY;
}
connect(ho, po, transport, srv, extra) {
#ifndef _flag_disable_network_circuit_connect
if (interactive()) return -8;
P3(("connect: %O, %O, %O, %O for %O\n", ho, po, transport, srv, ME))
if (time() < time_of_connect_attempt + waitforme) return -2;
if (ho) { // paranoid: stringp(ho) && strlen(ho)) {
if (po) port = po;
# ifndef ERQ_WITHOUT_SRV
if (srv) {
hostname = lower_case(ho);
host = 0;
} else
# endif
host = lower_case(ho);
P2(("connect.%s:\t%O, %O, %O\t%O\n", srv || "to",
ho, po, transport, ME))
}
# ifndef ERQ_WITHOUT_SRV
P4(("connect->srv_choose? depends on srv %O\n", srv))
if (srv) return dns_srv_resolve(hostname, srv, // _psyc._tls.domain
transport == "s" ? "tls" : "tcp", #'srv_choose,
transport);
# endif
if (::connect(host, port, transport, extra) >= 0)
time_of_connect_attempt = time();
#endif
}
disconnected(remaining) {
int rc = 0; // unexpected
if (qSize(me)) {
rc = ::disconnected(remaining);
reconnect();
}
else {
P2(("%O circuit to %O disconnected and terminated\n", ME, me))
// we should unregister all our hostnames and ip numbers
// so that they get checked again once when a new circuit
// is established... TODO
destruct(ME);
}
return rc;
}
// varargs just to support mvars in FORK mode
varargs int enqueue(mixed source, string method, string data,
mapping vars, int showingLog, mixed target, mapping mvars) {
// psyc_sendmsg() sets vars["_source"] in case
// the source got destructed in the meantime.
// other enqueuers should do the same i guess.
// in fact it would be nicer to do it here at
// enqueue, but psyc_sendmsg() has already done
// the psyc_name calculation, so better use that.
// let's see if this code gets used.. yep it does
#if 0 // DEBUG > 0
// with proper routing it is now quite common to have a public message
// with a context *instead* of a source, so it's pointless to complain...
//
// unless (vars["_source"]) {
// P1(("tell lynX: enqueue without _source for %O from %O in %O\n",
// method, source, ME))
// //vars["_source"] = psyc_name(source);
// raise_error("tell lynX where it happened!!\n");
// }
#endif
P4(("enqueue for %O\n", source))
connect(); // will only connect if we once had been connected before
return ::enqueue(me, ({ source, method, data, vars, target, mvars }) );
}