ndb/dns: various changes

stop absolute/relative dual use of RR.ttl. now RR.ttl is
*always* the *relative* ttl value. we derive absolute
timeout in RR.expire.

remove unused lookuptime field in DN. replace refs and
keep with mark field in DN. we do not care about the
number of references. only *iff* it is referenced, so
use a single bit for that (bit 0). for keep, we use
bit 1.

remove dolock parameter in dnagenever(), it is not
needed. we always need to lock.

mark local dns servers and domains as never to be aged.

the keeper bit is *just* a cache optimization, preventing
the domain and the domains it points to from being flushed.
it should not be used as a write protect bit in rrattach()
for preventing spoofing as it will prevent updates of say,
cname domains.

remove "removing spam ..." message. these are usualy just
hints, so normal. still, remove the hint as we currently
do no check if the nameserver has authority over the
cname domain.

remove "mydnsquery: trying to send to myself (%s); bzzzt"
message. this can happen when myaddr() fails for other
reasons. myaddr() will print error for us anyway.

1 files changed, 40 insertions, 39 deletions

diff --git a/sys/src/cmd/ndb/dn.c b/sys/src/cmd/ndb/dn.c
index ffc55ef8f..7383c9e4b 100644
--- a/sys/src/cmd/ndb/dn.c
+++ b/sys/src/cmd/ndb/dn.c
@@ -14,14 +14,10 @@
  * figure it out.
  */
 enum {
-//	Deftarget	= 1<<30,	/* effectively disable aging */
-//	Minage		= 1<<30,
-//	Defagefreq	= 1<<30,	/* age names this often (seconds) */
-
 	/* these settings will trigger frequent aging */
 	Deftarget	= 4000,
-	Minage		=  5*60,
-	Defagefreq	= 15*60,	/* age names this often (seconds) */
+	Minage		=  5*Min,
+	Defagefreq	= 15*Min,	/* age names this often (seconds) */
 };
 
 /*
@@ -305,9 +301,9 @@ dndump(char *file)
 		for(dp = ht[i]; dp; dp = dp->next){
 			fprint(fd, "%s\n", dp->name);
 			for(rp = dp->rr; rp; rp = rp->next) {
-				fprint(fd, "\t%R %c%c %lud/%lud\n",
+				fprint(fd, "\t%R %c%c %ld/%lud\n",
 					rp, rp->auth? 'A': 'U',
-					rp->db? 'D': 'N', rp->expire, rp->ttl);
+					rp->db? 'D': 'N', (long)(rp->expire - now), rp->ttl);
 				if (rronlist(rp, rp->next))
 					fprint(fd, "*** duplicate:\n");
 			}
@@ -372,29 +368,28 @@ dnage(DN *dp)
 	if (canlock(&dnlock))
 		abort();	/* dnage called with dnlock not held */
 	diff = now - dp->referenced;
-	if(diff < Reserved || dp->keep)
+	if(diff < Reserved || dp->mark != 0)
 		return;
 
 	l = &dp->rr;
 	while ((rp = *l) != nil){
 		assert(rp->magic == RRmagic && rp->cached);
-		if(!rp->db && (rp->expire < now || diff > dnvars.oldest))
+		if(!rp->db && ((long)(rp->expire - now) <= 0 || diff > dnvars.oldest))
 			rrdelhead(l); /* rp == *l before; *l == rp->next after */
 		else
 			l = &rp->next;
 	}
 }
 
-#define MARK(dp)	{ if (dp) (dp)->keep = 1; }
+#define MARK(dp)	{ if (dp) (dp)->mark |= 2; }
 
 /* mark a domain name and those in its RRs as never to be aged */
 void
-dnagenever(DN *dp, int dolock)
+dnagenever(DN *dp)
 {
 	RR *rp;
 
-	if (dolock)
-		lock(&dnlock);
+	lock(&dnlock);
 
 	/* mark all referenced domain names */
 	MARK(dp);
@@ -449,11 +444,10 @@ dnagenever(DN *dp, int dolock)
 		}
 	}
 
-	if (dolock)
-		unlock(&dnlock);
+	unlock(&dnlock);
 }
 
-#define REF(dp)	{ if (dp) (dp)->refs++; }
+#define REF(dp)	{ if (dp) (dp)->mark |= 1; }
 
 /*
  *  periodicly sweep for old records and remove unreferenced domain names
@@ -468,7 +462,7 @@ dnageall(int doit)
 	RR *rp;
 	static ulong nextage;
 
-	if(dnvars.names < target || (now < nextage && !doit)){
+	if(dnvars.names < target || ((long)(nextage - now) > 0 && !doit)){
 		dnvars.oldest = maxage;
 		return;
 	}
@@ -483,14 +477,14 @@ dnageall(int doit)
 	if (agefreq > dnvars.oldest / 2)
 		nextage = now + dnvars.oldest / 2;
 	else
-		nextage = now + agefreq;
+		nextage = now + (ulong)agefreq;
 
 	lock(&dnlock);
 
 	/* time out all old entries (and set refs to 0) */
 	for(i = 0; i < HTLEN; i++)
 		for(dp = ht[i]; dp; dp = dp->next){
-			dp->refs = 0;
+			dp->mark &= ~1;
 			dnage(dp);
 		}
 
@@ -552,7 +546,7 @@ dnageall(int doit)
 	for(i = 0; i < HTLEN; i++){
 		l = &ht[i];
 		for(dp = *l; dp; dp = *l){
-			if(dp->rr == nil && dp->refs == 0 && dp->keep == 0){
+			if(dp->rr == nil && dp->mark == 0){
 				assert(dp->magic == DNmagic);
 				*l = dp->next;
 
@@ -586,7 +580,7 @@ dnagedb(void)
 	/* time out all database entries */
 	for(i = 0; i < HTLEN; i++)
 		for(dp = ht[i]; dp; dp = dp->next) {
-			dp->keep = 0;
+			dp->mark = 0;
 			for(rp = dp->rr; rp; rp = rp->next)
 				if(rp->db)
 					rp->expire = 0;
@@ -738,23 +732,29 @@ rrattach1(RR *new, int auth)
 	RR **l;
 	RR *rp;
 	DN *dp;
+	ulong ttl;
 
 	assert(new->magic == RRmagic && !new->cached);
-	if(!new->db) {
-		/*
-		 * try not to let responses expire before we
-		 * can use them to complete this query, by extending
-		 * past (or nearly past) expiration time.
-		 */
-		new->expire = new->ttl > now + Min? new->ttl: now + 10*Min;
-	} else
-		new->expire = now + Year;
+
 	dp = new->owner;
 	assert(dp != nil && dp->magic == DNmagic);
 	new->auth |= auth;
 	new->next = 0;
 
 	/*
+	 * try not to let responses expire before we
+	 * can use them to complete this query, by extending
+	 * past (or nearly past) expiration time.
+	 */
+	if(new->db)
+		ttl = Year;
+	else
+		ttl = new->ttl;
+	if(ttl <= Min)
+		ttl = 10*Min;
+	new->expire = now + ttl;
+
+	/*
 	 *  find first rr of the right type
 	 */
 	l = &dp->rr;
@@ -788,9 +788,8 @@ rrattach1(RR *new, int auth)
 			}
 			/* all things equal, pick the newer one */
 			else if(rp->arg0 == new->arg0 && rp->arg1 == new->arg1){
-				/* new drives out old */
-				if (new->ttl <= rp->ttl &&
-				    new->expire <= rp->expire) {
+				/* old drives out new */
+				if((long)(rp->expire - new->expire) > 0) {
 					rrfree(new);
 					return;
 				}
@@ -842,8 +841,8 @@ rrattach(RR *rp, int auth)
 		next = rp->next;
 		rp->next = nil;
 		dp = rp->owner;
-		/* avoid any outside spoofing; leave keepers alone */
-		if(cfg.cachedb && !rp->db && (dp->keep || inmyarea(dp->name)))
+		/* avoid any outside spoofing */
+		if(cfg.cachedb && !rp->db && inmyarea(dp->name))
 			rrfree(rp);
 		else
 			rrattach1(rp, auth);
@@ -974,8 +973,8 @@ rrlookup(DN *dp, int type, int flag)
 	for(rp = dp->rr; rp; rp = rp->next){
 		if(!rp->db)
 		if(rp->auth)
-		if(rp->ttl + 60 > now)
-		if(tsame(type, rp->type)){
+		if((long)(rp->expire - now) > 0)
+ 		if(tsame(type, rp->type)){
 			if(flag == NOneg && rp->negative)
 				goto out;
 			last = rrcopy(rp, last);
@@ -987,7 +986,7 @@ rrlookup(DN *dp, int type, int flag)
 	/* try for a living unauthoritative network entry */
 	for(rp = dp->rr; rp; rp = rp->next){
 		if(!rp->db)
-		if(rp->ttl + 60 > now)
+		if((long)(rp->expire - now) > 0)
 		if(tsame(type, rp->type)){
 			if(flag == NOneg && rp->negative)
 				goto out;
@@ -1822,7 +1821,9 @@ dnptr(uchar *net, uchar *mask, char *dom, int forwtype, int subdoms, int ttl)
 	for(rp = first; rp != nil; rp = nrp){
 		nrp = rp->next;
 		rp->next = nil;
+		dp = rp->owner;
 		rrattach(rp, Authoritative);
+		dnagenever(dp);
 	}
 }