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#include <u.h>
#include <libc.h>
#include <ip.h>
#include <bio.h>
#include <ndb.h>
#include "dns.h"
/* get a notification from another system of a changed zone */
void
dnnotify(DNSmsg *reqp, DNSmsg *repp, Request *r)
{
RR *tp;
Area *a;
USED(r);
/* move one question from reqp to repp */
memset(repp, 0, sizeof(*repp));
tp = reqp->qd;
reqp->qd = tp->next;
tp->next = 0;
repp->qd = tp;
repp->id = reqp->id;
repp->flags = Fresp | Onotify | Fauth;
/* anything to do? */
if(zonerefreshprogram == nil)
return;
/* make sure its the right type */
if(repp->qd->type != Tsoa)
return;
syslog(0, logfile, "notification for %s", repp->qd->owner->name);
/* is it something we care about? */
a = inmyarea(repp->qd->owner->name);
if(a == nil)
return;
syslog(0, logfile, "serial old %lud new %lud", a->soarr->soa->serial, repp->qd->soa->serial);
/* do nothing if it didn't change */
if(a->soarr->soa->serial== repp->qd->soa->serial)
return;
a->needrefresh = 1;
}
static void
ding(void *u, char *msg)
{
USED(u);
if(strstr(msg, "alarm"))
noted(NCONT);
else
noted(NDFLT);
}
/* 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;
uchar obuf[Maxudp+OUdphdrsize];
uchar ibuf[Maxudp+OUdphdrsize];
RR *rp;
OUdphdr *up = (OUdphdr*)obuf;
char *err;
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) {
parseip(up->raddr, slave);
} else {
rp = dnresolve(slave, Cin, Ta, req, nil, 0, 1, 1, &status);
if(rp == nil)
return;
parseip(up->raddr, rp->ip->name);
rrfree(rp);
}
fd = udpport();
if(fd < 0)
return;
notify(ding);
/* send 3 times or until we get anything back */
for(i = 0; i < 3; i++){
syslog(0, logfile, "sending %d byte notify to %s/%I.%d about %s", n, slave, up->raddr, nhgets(up->rport), soa->owner->name);
if(udpwrite(fd, (OUdphdr*)obuf, obuf+OUdphdrsize, n) != n)
break;
alarm(2*1000);
len = udpread(fd, (Udphdr*)ibuf, ibuf+OUdphdrsize, Maxudp);
alarm(0);
if(len <= OUdphdrsize)
continue;
err = convM2DNS(&ibuf[OUdphdrsize], len, &repmsg);
if(err != nil)
continue;
if(repmsg.id == reqno && (repmsg.flags & Omask) == Onotify)
break;
}
close(fd);
}
/* send notifies for any updated areas */
static void
notify_areas(Area *a, Request *req)
{
Server *s;
for(; a != nil; a = a->next){
if(!a->neednotify)
continue;
/* send notifies to all slaves */
for(s = a->soarr->soa->slaves; s != nil; s = s->next)
send_notify(s->name, a->soarr, req);
a->neednotify = 0;
}
}
/*
* process to notify other servers of changes
* (also reads in new databases)
*/
void
notifyproc(void)
{
Request req;
static int already;
if(already)
return;
switch(rfork(RFPROC|RFNOTEG|RFMEM|RFNOWAIT)){
case -1:
return;
case 0:
break;
default:
return;
}
req.isslave = 1; /* son't fork off subprocesses */
for(;;){
getactivity(&req);
notify_areas(owned, &req);
putactivity();
sleep(60*1000);
}
}
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