ip/ipconfig: ignore default routes targeting ourselfs

when running ndb configuration, we might inherit the ipgw=
attribute from the ipnet pointing to our own ip address
(we are the default gateway). ignore such entries.

do not add default routes with gateway equal to our own
local (ip4) or link-local ip address (ipv6).

2 files changed, 34 insertions, 10 deletions

diff --git a/sys/src/cmd/ip/ipconfig/ipv6.c b/sys/src/cmd/ip/ipconfig/ipv6.c
index 7ea91599d..469501f5d 100644
--- a/sys/src/cmd/ip/ipconfig/ipv6.c
+++ b/sys/src/cmd/ip/ipconfig/ipv6.c
@@ -384,7 +384,9 @@ Again:
 	}
 
 	if(!tentative){
-		if(validip(conf.gaddr) && !isv4(conf.gaddr))
+		if(validip(conf.gaddr) && !isv4(conf.gaddr)
+		&& ipcmp(conf.gaddr, conf.laddr) != 0
+		&& ipcmp(conf.gaddr, conf.lladdr) != 0)
 			adddefroute(conf.gaddr, conf.laddr, conf.laddr, conf.mask);
 		return 0;
 	}
@@ -758,7 +760,9 @@ recvrahost(uchar buf[], int pktlen)
 		DEBUG("got RA from %I on %s; pfx %I %M",
 			ra->src, conf.dev, conf.v6pref, conf.mask);
 
-		if(validip(conf.gaddr))
+		if(validip(conf.gaddr)
+		&& ipcmp(conf.gaddr, conf.laddr) != 0
+		&& ipcmp(conf.gaddr, conf.lladdr) != 0)
 			adddefroute(conf.gaddr, conf.lladdr, conf.laddr, conf.mask);
 
 		if(noconfig)
diff --git a/sys/src/cmd/ip/ipconfig/main.c b/sys/src/cmd/ip/ipconfig/main.c
index 8ae24c5c0..e06b8404d 100644
--- a/sys/src/cmd/ip/ipconfig/main.c
+++ b/sys/src/cmd/ip/ipconfig/main.c
@@ -598,7 +598,8 @@ ip4cfg(void)
 		return -1;
 	}
 
-	if(validip(conf.gaddr) && isv4(conf.gaddr))
+	if(validip(conf.gaddr) && isv4(conf.gaddr)
+	&& ipcmp(conf.gaddr, conf.laddr) != 0)
 		adddefroute(conf.gaddr, conf.laddr, conf.laddr, conf.mask);
 
 	return 0;
@@ -987,6 +988,23 @@ uniquent(Ndbtuple *t)
 	return t;
 }
 
+/* my ips from ndb, read by ndbconfig() below */
+static uchar dbips[128*IPaddrlen];
+
+static int
+ipindb(uchar *ip)
+{
+	uchar *a;
+
+	for(a = dbips; a < &dbips[sizeof(dbips)]; a += IPaddrlen){
+		if(!validip(a))
+			break;
+		if(ipcmp(ip, a) == 0)
+			return 1;
+	}
+	return 0;
+}
+
 /* read configuration (except laddr) for myip from ndb */
 void
 ndb2conf(Ndb *db, uchar *myip)
@@ -1040,8 +1058,11 @@ ndb2conf(Ndb *db, uchar *myip)
 			continue;
 		}
 		if(strcmp(nt->attr, "ipgw") == 0) {
-			nt = uniquent(nt);
+			/* ignore in case we are the gateway */
+			if(ipindb(ip))
+				continue;
 			ipmove(conf.gaddr, ip);
+			nt = uniquent(nt);
 		} else if(strcmp(nt->attr, "dns") == 0) {
 			addaddrs(conf.dns, sizeof(conf.dns), ip, IPaddrlen);
 		} else if(strcmp(nt->attr, "ntp") == 0) {
@@ -1070,7 +1091,6 @@ opendatabase(void)
 static void
 ndbconfig(void)
 {
-	uchar ips[128*IPaddrlen];
 	char etheraddr[32], *attr;
 	Ndbtuple *t, *nt;
 	Ndb *db;
@@ -1086,7 +1106,7 @@ ndbconfig(void)
 		return;
 	}
 
-	memset(ips, 0, sizeof(ips));
+	memset(dbips, 0, sizeof(dbips));
 
 	if(conf.hwatype != 1)
 		sysfatal("can't read hardware address");
@@ -1100,18 +1120,18 @@ ndbconfig(void)
 				nt->attr, nt->val);
 			continue;
 		}
-		addaddrs(ips, sizeof(ips), conf.laddr, IPaddrlen);
+		addaddrs(dbips, sizeof(dbips), conf.laddr, IPaddrlen);
 	}
 	ndbfree(t);
 
-	n = countaddrs(ips, sizeof(ips));
+	n = countaddrs(dbips, sizeof(dbips));
 	if(n == 0)
 		sysfatal("no ip addresses found in ndb");
 
 	/* add link local address first, if not already done */
 	if(!findllip(conf.lladdr, ifc)){
 		for(i = 0; i < n; i++){
-			ipmove(conf.laddr, ips+i*IPaddrlen);
+			ipmove(conf.laddr, dbips+i*IPaddrlen);
 			if(ISIPV6LINKLOCAL(conf.laddr)){
 				ipv6auto = 0;
 				ipmove(conf.lladdr, conf.laddr);
@@ -1128,7 +1148,7 @@ ndbconfig(void)
 
 	/* add v4 addresses and v6 if link local address is available */
 	for(i = 0; i < n; i++){
-		ipmove(conf.laddr, ips+i*IPaddrlen);
+		ipmove(conf.laddr, dbips+i*IPaddrlen);
 		if(isv4(conf.laddr) || ipcmp(conf.laddr, conf.lladdr) != 0){
 			ndb2conf(db, conf.laddr);
 			doadd();