psyced/world/net/psyc/udp.c
2011-01-19 10:47:26 +01:00

100 lines
2.6 KiB
C

// vim:foldmethod=marker:syntax=lpc:noexpandtab
// $Id: udp.c,v 1.36 2008/08/05 12:21:34 lynx Exp $
//
#include "common.h"
#include <net.h>
#include <person.h>
#include <services.h>
#include <uniform.h>
#include <psyc.h>
// SECURITY CONCERN:
// originating udp host and port numbers can rather easily be spoofed
// and currently many routers/gateways won't bother delivering a packet which
// couldn't possibly have come from that direction. UDP may generally
// need to be considered not trustworthy, even if it apparently comes
// from localhost. okay, hopefully our kernel is smart enough not to
// believe an incoming packet to be from localhost. it's his job!
#ifdef __PIKE__
import net.psyc.common;
#else
inherit PSYC_PATH "common";
#endif
// network location of remote server (hostname or hostname:port)
volatile mapping namecache = ([]);
// volatile int timeoutPending;
// TODO? should keep caches of host:port per remote target somewhat like tcp
#include "parse.i"
object load() { return ME; } // avoid a find_object call in obj/master
parseUDP2(host, ip, port, msg) {
string *m;
int i, l;
unless (stringp(host)) host = ip;
P3(( "parseUDP(%O,%O): %O\n", ip,port,msg ))
pvars = ([ ]);
// this call is a performance killer
// should UDP get used heavily.. TODO
// needs hash-based host matching, not linear
unless (hostCheck(ip, port, 1)) {
log_file("PSYCBLOCK", "UDP from "+ip
+" ignored » "+msg+" «\n");
// netloc = "psyc://"+ip+":"+port;
// sendmsg(netloc, "_error_illegal_source",
// "Sorry, my configuration does not permit to talk to you.\n");
return;
}
//netloc = "psyc://"+ip;
peeraddr = peerhost = host;
if (port != PSYC_SERVICE) {
peerport = port;
peeraddr += ":"+port+"d"; // this is a UDP peerport
}
// else: we presume a UDP 4404 also listens on TCP
#if 0
P1(("./psyc/udp.c: paranoid extra restart\n"))
restart(); // leading . does that anyway
#endif
pvars["_INTERNAL_source"] = "psyc://"+peeraddr+"/";
// m = regexplode(msg, "\r?\n"); ?
m = explode(msg, "\n");
for (l=0; l<sizeof(m); l++) {
// i'd like to know why no-mc has to be an empty string
// rather than NULL from now on.
// should you find out, pls tell me.. -lynX
if (sizeof(mc)) getdata(m[l]);
else unless (parse(m[l])) {
log_file("PSYCHACK", "Can't parseUDP(%s): %O in %O\n",
peeraddr,m[l],msg );
return;
}
}
}
parseUDP(ip, port, msg) {
dns_rresolve(ip, #'parseUDP2, ip, port, msg);
}
#if 0
// in other words.. this shouldnt get called :)
pr(mc, fmt, a,b,c,d,e,f,g,h,i,j,k) {
D("PSYC/UDP pr("+mc+", "+S(fmt, a,b,c,d,e,f,g,h,i,j,k)+")\n");
}
#endif
// no syntax error messages via udp
croak(a,b,c,d,e,f) {}