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ndb/dns: cleanup forwarding code (redistrib())

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instead of copying the whole packet, just save the
udp header and restore it aftwards. dont call redistrib()
when there are no forwards (this should be almost always
the case).
This commit is contained in:
cinap_lenrek 2015-06-14 21:31:44 +02:00
parent ffd294e0da
commit 65db705481
2 changed files with 15 additions and 13 deletions
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1
sys/src/cmd/ndb/dns.h
View file

@ -523,7 +523,6 @@ void initdnsmsg(DNSmsg *mp, RR *rp, int flags, ushort reqno);
/* dnserver.c */
void dnserver(DNSmsg*, DNSmsg*, Request*, uchar *, int);
void dnudpserver(char*);
void dntcpserver(char*);
/* dnnotify.c */
void dnnotify(DNSmsg*, DNSmsg*, Request*);

27
sys/src/cmd/ndb/dnudpserver.c
View file

@ -29,7 +29,7 @@ struct Forwtarg {
ulong lastdial;
};
Forwtarg forwtarg[10];
int currtarg;
int forwtcount;
static char *hmsg = "headers";
@ -75,11 +75,11 @@ addforwtarg(char *host)
{
Forwtarg *tp;
if (currtarg >= nelem(forwtarg)) {
if (forwtcount >= nelem(forwtarg)) {
dnslog("too many forwarding targets");
return -1;
}
tp = forwtarg + currtarg;
tp = forwtarg + forwtcount;
if (parseip(tp->addr, host) < 0) {
dnslog("can't parse ip %s", host);
return -1;
@ -91,7 +91,7 @@ addforwtarg(char *host)
free(tp->host);
tp->host = estrdup(host);
currtarg++;
forwtcount++;
return 0;
}
@ -102,18 +102,18 @@ addforwtarg(char *host)
static void
redistrib(uchar *buf, int len)
{
static uchar outpkt[Udphdrsize + Maxudp + 1024];
uchar save[Udphdrsize];
Forwtarg *tp;
Udphdr *uh;
assert(len <= sizeof outpkt);
memmove(outpkt, buf, len);
uh = (Udphdr *)outpkt;
for (tp = forwtarg; tp < forwtarg + currtarg; tp++)
memmove(save, buf, Udphdrsize);
uh = (Udphdr *)buf;
for (tp = forwtarg; tp < forwtarg + forwtcount; tp++)
if (tp->fd > 0) {
memmove(outpkt, tp->addr, sizeof tp->addr);
memmove(uh->raddr, tp->addr, sizeof tp->addr);
hnputs(uh->rport, 53); /* dns port */
if (write(tp->fd, outpkt, len) != len) {
if (write(tp->fd, buf, len) != len) {
close(tp->fd);
tp->fd = -1;
}
@ -121,6 +121,8 @@ redistrib(uchar *buf, int len)
tp->lastdial = time(nil);
tp->fd = udpport(mntpt);
}
memmove(buf, save, Udphdrsize);
}
/*
@ -180,7 +182,8 @@ restart:
if(len <= Udphdrsize)
goto restart;
redistrib(buf, len);
if(forwtcount > 0)
redistrib(buf, len);
uh = (Udphdr*)buf;
len -= Udphdrsize;