/* notify a slave that an area has changed. */
static void
send_notify(char *slave, RR *soa, Request *req)
{
int i, len, n, reqno, status, fd;
char *err;
uchar ibuf[Maxudp+Udphdrsize], obuf[Maxudp+Udphdrsize];
RR *rp;
Udphdr *up = (Udphdr*)obuf;
DNSmsg repmsg;
/* create the request */
reqno = rand();
n = mkreq(soa->owner, Cin, obuf, Fauth | Onotify, reqno);
/* get an address */
if(strcmp(ipattr(slave), "ip") == 0) {
if (parseip(up->raddr, slave) == -1)
dnslog("bad address %s to notify", slave);
} else {
rp = dnresolve(slave, Cin, Ta, req, nil, 0, 1, 1, &status);
if(rp == nil)
rp = dnresolve(slave, Cin, Taaaa, req, nil, 0, 1, 1, &status);
if(rp == nil)
return;
parseip(up->raddr, rp->ip->name);
rrfreelist(rp); /* was rrfree */
}
fd = udpport(nil);
if(fd < 0)
return;
/* send 3 times or until we get anything back */
n += Udphdrsize;
for(i = 0; i < 3; i++, freeanswers(&repmsg)){
dnslog("sending %d byte notify to %s/%I.%d about %s", n, slave,
up->raddr, nhgets(up->rport), soa->owner->name);
memset(&repmsg, 0, sizeof repmsg);
if(write(fd, obuf, n) != n)
break;
alarm(2*1000);
len = read(fd, ibuf, sizeof ibuf);
alarm(0);
if(len <= Udphdrsize)
continue;
err = convM2DNS(&ibuf[Udphdrsize], len, &repmsg, nil);
if(err != nil) {
free(err);
continue;
}
if(repmsg.id == reqno && (repmsg.flags & Omask) == Onotify)
break;
}
if (i < 3)
freeanswers(&repmsg);
close(fd);
}
static int
p_seprint(Msg *m)
{
char *e;
if((e = convM2DNS(m->ps, m->pe-m->ps, &dm, nil)) != nil){
m->p = seprint(m->p, m->e, "error: %s", e);
return 0;
}
m->p = seprint(m->p, m->e, "id=%d flags=%#ux", dm.id, dm.flags);
donext(m);
return 0;
}
void
main(int argc, char *argv[])
{
int len, rcode;
char tname[32];
char *err, *ext = "";
unsigned char buf[64*1024], callip[IPaddrlen];
DNSmsg reqmsg, repmsg;
Request req;
alarm(2*60*1000);
cfg.cachedb = 1;
ARGBEGIN{
case 'd':
debug++;
break;
case 'f':
dbfile = EARGF(usage());
break;
case 'r':
cfg.resolver = 1;
break;
case 'R':
norecursion = 1;
break;
case 'x':
ext = EARGF(usage());
break;
default:
usage();
break;
}ARGEND
if(debug < 2)
debug = 0;
if(argc > 0)
getcaller(argv[0]);
cfg.inside = 1;
dninit();
snprint(mntpt, sizeof mntpt, "/net%s", ext);
if(myipaddr(ipaddr, mntpt) < 0)
sysfatal("can't read my ip address");
dnslog("dnstcp call from %s to %I", caller, ipaddr);
memset(callip, 0, sizeof callip);
parseip(callip, caller);
db2cache(1);
memset(&req, 0, sizeof req);
setjmp(req.mret);
req.isslave = 0;
procsetname("main loop");
/* loop on requests */
for(;; putactivity(0)){
now = time(nil);
memset(&repmsg, 0, sizeof repmsg);
len = readmsg(0, buf, sizeof buf);
if(len <= 0)
break;
getactivity(&req, 0);
req.aborttime = timems() + S2MS(15*Min);
rcode = 0;
memset(&reqmsg, 0, sizeof reqmsg);
err = convM2DNS(buf, len, &reqmsg, &rcode);
if(err){
dnslog("server: input error: %s from %s", err, caller);
free(err);
break;
}
if (rcode == 0) {
if(reqmsg.qdcount < 1){
dnslog("server: no questions from %s", caller);
break;
} else if(reqmsg.flags & Fresp){
dnslog("server: reply not request from %s",
caller);
break;
} else if((reqmsg.flags & Omask) != Oquery){
dnslog("server: op %d from %s",
reqmsg.flags & Omask, caller);
break;
}
}
if(debug)
dnslog("[%d] %d: serve (%s) %d %s %s",
getpid(), req.id, caller,
reqmsg.id, reqmsg.qd->owner->name,
rrname(reqmsg.qd->type, tname, sizeof tname));
/* loop through each question */
while(reqmsg.qd)
if(reqmsg.qd->type == Taxfr)
dnzone(&reqmsg, &repmsg, &req);
else {
dnserver(&reqmsg, &repmsg, &req, callip, rcode);
reply(1, &repmsg, &req);
rrfreelist(repmsg.qd);
rrfreelist(repmsg.an);
rrfreelist(repmsg.ns);
rrfreelist(repmsg.ar);
}
rrfreelist(reqmsg.qd); /* qd will be nil */
rrfreelist(reqmsg.an);
rrfreelist(reqmsg.ns);
rrfreelist(reqmsg.ar);
if(req.isslave){
putactivity(0);
_exits(0);
}
}
refreshmain(mntpt);
}
/*
* a process to act as a dns server for outside reqeusts
*/
void
dnudpserver(char *mntpt)
{
volatile int fd, len, op, rcode;
char *volatile err;
volatile char tname[32];
volatile uchar buf[Udphdrsize + Maxudp + 1024];
volatile DNSmsg reqmsg, repmsg;
Inprogress *volatile p;
volatile Request req;
Udphdr *volatile uh;
/*
* fork sharing text, data, and bss with parent.
* stay in the same note group.
*/
switch(rfork(RFPROC|RFMEM|RFNOWAIT)){
case -1:
break;
case 0:
break;
default:
return;
}
fd = -1;
restart:
procsetname("udp server announcing");
if(fd >= 0)
close(fd);
while((fd = udpannounce(mntpt)) < 0)
sleep(5000);
// procsetname("udp server");
memset(&req, 0, sizeof req);
if(setjmp(req.mret))
putactivity(0);
req.isslave = 0;
req.id = 0;
req.aborttime = 0;
/* loop on requests */
for(;; putactivity(0)){
procsetname("served %d udp; %d alarms",
stats.qrecvdudp, stats.alarms);
memset(&repmsg, 0, sizeof repmsg);
memset(&reqmsg, 0, sizeof reqmsg);
alarm(60*1000);
len = read(fd, buf, sizeof buf);
alarm(0);
if(len <= Udphdrsize)
goto restart;
redistrib(buf, len);
uh = (Udphdr*)buf;
len -= Udphdrsize;
// dnslog("read received UDP from %I to %I",
// ((Udphdr*)buf)->raddr, ((Udphdr*)buf)->laddr);
getactivity(&req, 0);
req.aborttime = timems() + Maxreqtm;
// req.from = smprint("%I", ((Udphdr*)buf)->raddr);
req.from = smprint("%I", buf);
rcode = 0;
stats.qrecvdudp++;
err = convM2DNS(&buf[Udphdrsize], len, &reqmsg, &rcode);
if(err){
/* first bytes in buf are source IP addr */
dnslog("server: input error: %s from %I", err, buf);
free(err);
goto freereq;
}
if (rcode == 0)
if(reqmsg.qdcount < 1){
dnslog("server: no questions from %I", buf);
goto freereq;
} else if(reqmsg.flags & Fresp){
dnslog("server: reply not request from %I", buf);
goto freereq;
}
op = reqmsg.flags & Omask;
if(op != Oquery && op != Onotify){
dnslog("server: op %d from %I", reqmsg.flags & Omask,
buf);
goto freereq;
}
if(debug || (trace && subsume(trace, reqmsg.qd->owner->name)))
dnslog("%d: serve (%I/%d) %d %s %s",
req.id, buf, uh->rport[0]<<8 | uh->rport[1],
reqmsg.id, reqmsg.qd->owner->name,
rrname(reqmsg.qd->type, tname, sizeof tname));
p = clientrxmit(&reqmsg, buf);
if(p == nil){
if(debug)
dnslog("%d: duplicate", req.id);
goto freereq;
}
if (Logqueries) {
RR *rr;
for (rr = reqmsg.qd; rr; rr = rr->next)
syslog(0, "dnsq", "id %d: (%I/%d) %d %s %s",
req.id, buf, uh->rport[0]<<8 |
uh->rport[1], reqmsg.id,
reqmsg.qd->owner->name,
rrname(reqmsg.qd->type, tname,
sizeof tname));
}
/* loop through each question */
while(reqmsg.qd){
memset(&repmsg, 0, sizeof repmsg);
switch(op){
case Oquery:
dnserver(&reqmsg, &repmsg, &req, buf, rcode);
break;
case Onotify:
dnnotify(&reqmsg, &repmsg, &req);
break;
}
/* send reply on fd to address in buf's udp hdr */
reply(fd, buf, &repmsg, &req);
freeanswers(&repmsg);
}
p->inuse = 0;
freereq:
free(req.from);
req.from = nil;
freeanswers(&reqmsg);
if(req.isslave){
putactivity(0);
_exits(0);
}
}
}
