Plan 9 from Bell Labs 2011-04-12

sys/include/String.h

@@ -42,4 +42,4 @@ typedef struct Sinstack Sinstack;
 extern char	*s_rdinstack(Sinstack*, String*);
 extern Sinstack	*s_allocinstack(char*);
 extern void	s_freeinstack(Sinstack*);
-#endif BGETC
+#endif /* BGETC */

sys/lib/dist/pc/mkfile

@@ -1,6 +1,7 @@
 out=outside			# outside web server
 s=/sys/lib/dist/pc
 x=`{bind -b /sys/lib/dist/bin/$cputype /bin}
+
 default:V: ndisk
 	ls -l ndisk
 
@@ -55,9 +56,9 @@ root.bz2:Q: boot.bz2
 # generated fat filesystem.  the same is true for plan9.ini.cd and plan9.ini.
 
 9load: /386/9loadlite
-#	cp $prereq $target
-	if (test -e /386/9loadnousb)
-		cp  /386/9loadnousb $target	# cater to old bioses
+	cp $prereq $target
+#	if (test -e /386/9loadnousb)
+#		cp  /386/9loadnousb $target	# cater to old bioses
 	cp /386/9loadlitedebug 9loaddebug
 
 ndisk: 9load /sys/src/9/pc/9pcflop.gz plan9.ini /lib/vgadb

sys/src/cmd/ndb/dn.c

@@ -847,7 +847,7 @@ rrattach1(RR *new, int auth)
 void
 rrattach(RR *rp, int auth)
 {
-	RR *next;
+	RR *next, *tp;
 	DN *dp;
 
 	lock(&dnlock);
@@ -865,8 +865,9 @@ rrattach(RR *rp, int auth)
 			if (0 && rrlistlen(dp->rr) > 50 && !dp->keep) {
 				dnslog("rrattach(%s): rr list too long; "
 					"freeing it", dp->name);
-				rrfreelist(dp->rr);
+				tp = dp->rr;
 				dp->rr = nil;
+				rrfreelist(tp);
 			} else
 				USED(dp);
 			rrattach1(rp, auth);

sys/src/cmd/ndb/dnresolve.c

@@ -17,12 +17,23 @@ enum
 	Udp, Tcp,
 
 	Maxdest=	24,	/* maximum destinations for a request message */
-	Maxtrans=	3,	/* maximum transmissions to a server */
-	Maxretries=	3, /* cname+actual resends: was 32; have pity on user */
-	Maxwaitms=	1000,	/* wait no longer for a remote dns query */
-	Minwaitms=	100,	/* willing to wait for a remote dns query */
-	Remntretry=	15,	/* min. sec.s between /net.alt remount tries */
 	Maxoutstanding=	15,	/* max. outstanding queries per domain name */
+	Remntretry=	15,	/* min. sec.s between /net.alt remount tries */
+
+	/*
+	 * these are the old values; we're trying longer timeouts now
+	 * primarily for the benefit of remote nameservers querying us
+	 * during times of bad connectivity.
+	 */
+//	Maxtrans=	3,	/* maximum transmissions to a server */
+//	Maxretries=	3, /* cname+actual resends: was 32; have pity on user */
+//	Maxwaitms=	1000,	/* wait no longer for a remote dns query */
+//	Minwaitms=	100,	/* willing to wait for a remote dns query */
+
+	Maxtrans=	5,	/* maximum transmissions to a server */
+	Maxretries=	5, /* cname+actual resends: was 32; have pity on user */
+	Maxwaitms=	5000,	/* wait no longer for a remote dns query */
+	Minwaitms=	500,	/* willing to wait for a remote dns query */
 
 	Destmagic=	0xcafebabe,
 	Querymagic=	0xdeadbeef,
@@ -116,6 +127,18 @@ procgetname(void)
 	return strdup(lp+1);
 }
 
+void
+rrfreelistptr(RR **rpp)
+{
+	RR *rp;
+
+	if (rpp == nil || *rpp == nil)
+		return;
+	rp = *rpp;
+	*rpp = nil;		/* update pointer in memory before freeing */
+	rrfreelist(rp);
+}
+
 /*
  *  lookup 'type' info for domain name 'name'.  If it doesn't exist, try
  *  looking it up as a canonical name.
@@ -608,11 +631,10 @@ mkreq(DN *dp, int type, uchar *buf, int flags, ushort reqno)
 void
 freeanswers(DNSmsg *mp)
 {
-	rrfreelist(mp->qd);
-	rrfreelist(mp->an);
-	rrfreelist(mp->ns);
-	rrfreelist(mp->ar);
-	mp->qd = mp->an = mp->ns = mp->ar = nil;
+	rrfreelistptr(&mp->qd);
+	rrfreelistptr(&mp->an);
+	rrfreelistptr(&mp->ns);
+	rrfreelistptr(&mp->ar);
 }
 
 /* timed read of reply.  sets srcip */
@@ -656,7 +678,7 @@ readnet(Query *qp, int medium, uchar *ibuf, uvlong endms, uchar **replyp,
 			dnslog("readnet: %s: tcp fd unset for dest %I",
 				qp->dp->name, qp->tcpip);
 		else if (readn(fd, lenbuf, 2) != 2) {
-			dnslog("readnet: short read of tcp size from %I",
+			dnslog("readnet: short read of 2-byte tcp msg size from %I",
 				qp->tcpip);
 			/* probably a time-out */
 			notestats(startns, 1, qp->type);
@@ -893,10 +915,8 @@ cacheneg(DN *dp, int type, int rcode, RR *soarr)
 
 	/* no cache time specified, don't make anything up */
 	if(soarr != nil){
-		if(soarr->next != nil){
-			rrfreelist(soarr->next);
-			soarr->next = nil;
-		}
+		if(soarr->next != nil)
+			rrfreelistptr(&soarr->next);
 		soaowner = soarr->owner;
 	} else
 		soaowner = nil;
@@ -1169,8 +1189,7 @@ procansw(Query *qp, DNSmsg *mp, uchar *srcip, int depth, Dest *p)
 				p->code = Rserver;
 			return -1;
 		}
-		rrfreelist(mp->ns);
-		mp->ns = nil;
+		rrfreelistptr(&mp->ns);
 	}
 
 	/* remove any soa's from the authority section */
@@ -1182,6 +1201,7 @@ procansw(Query *qp, DNSmsg *mp, uchar *srcip, int depth, Dest *p)
 	unique(mp->ns);
 	unique(mp->ar);
 	unlock(&dnlock);
+
 	if(mp->an)
 		rrattach(mp->an, (mp->flags & Fauth) != 0);
 	if(mp->ar)
@@ -1191,15 +1211,12 @@ procansw(Query *qp, DNSmsg *mp, uchar *srcip, int depth, Dest *p)
 		rrattach(mp->ns, Notauthoritative);
 	} else {
 		ndp = nil;
-		rrfreelist(mp->ns);
-		mp->ns = nil;
+		rrfreelistptr(&mp->ns);
 	}
 
 	/* free the question */
-	if(mp->qd) {
-		rrfreelist(mp->qd);
-		mp->qd = nil;
-	}
+	if(mp->qd)
+		rrfreelistptr(&mp->qd);
 
 	/*
 	 *  Any reply from an authoritative server,
@@ -1254,7 +1271,7 @@ procansw(Query *qp, DNSmsg *mp, uchar *srcip, int depth, Dest *p)
 	 *  netquery, which current holds qp->dp->querylck,
 	 *  so release it now and acquire it upon return.
 	 */
-//	lcktype = qtype2lck(qp->type);
+//	lcktype = qtype2lck(qp->type);		/* someday try this again */
 //	qunlock(&qp->dp->querylck[lcktype]);
 
 	nqp = emalloc(sizeof *nqp);

sys/src/cmd/ndb/dnserver.c

@@ -20,7 +20,7 @@ dnserver(DNSmsg *reqp, DNSmsg *repp, Request *req, uchar *srcip, int rcode)
 	char tname[32];
 	DN *nsdp, *dp;
 	Area *myarea;
-	RR *tp, *neg;
+	RR *tp, *neg, *rp;
 
 	dncheck(nil, 1);
 
@@ -109,8 +109,9 @@ dnserver(DNSmsg *reqp, DNSmsg *repp, Request *req, uchar *srcip, int rcode)
 			if(repp->ns){
 				/* don't pass on anything we know is wrong */
 				if(repp->ns->negative){
-					rrfreelist(repp->ns);
+					rp = repp->ns;
 					repp->ns = nil;
+					rrfreelist(rp);
 				}
 				break;
 			}