patch-2.4.19 linux-2.4.19/net/ipv4/fib_semantics.c

• Lines: 120
• Date: Fri Aug 2 17:39:46 2002
• Orig file: linux-2.4.18/net/ipv4/fib_semantics.c
• Orig date: Mon Feb 25 11:38:14 2002

diff -urN linux-2.4.18/net/ipv4/fib_semantics.c linux-2.4.19/net/ipv4/fib_semantics.c
@@ -56,6 +56,8 @@
 
 #ifdef CONFIG_IP_ROUTE_MULTIPATH
 
+static spinlock_t fib_multipath_lock = SPIN_LOCK_UNLOCKED;
+
 #define for_nexthops(fi) { int nhsel; const struct fib_nh * nh; \
 for (nhsel=0, nh = (fi)->fib_nh; nhsel < (fi)->fib_nhs; nh++, nhsel++)
 
@@ -183,6 +185,7 @@
 			continue;
 		for_nexthops(fi) {
 			if (nh->nh_dev == dev && nh->nh_gw == gw &&
+			    nh->nh_scope == RT_SCOPE_LINK &&
 			    !(nh->nh_flags&RTNH_F_DEAD)) {
 				read_unlock(&fib_info_lock);
 				return 0;
@@ -377,15 +380,23 @@
 		/* It is not necessary, but requires a bit of thinking */
 		if (key.scope < RT_SCOPE_LINK)
 			key.scope = RT_SCOPE_LINK;
-
 		if ((err = fib_lookup(&key, &res)) != 0)
 			return err;
+		err = -EINVAL;
+		if (res.type != RTN_UNICAST && res.type != RTN_LOCAL)
+			goto out;
 		nh->nh_scope = res.scope;
 		nh->nh_oif = FIB_RES_OIF(res);
-		nh->nh_dev = FIB_RES_DEV(res);
-		if (nh->nh_dev)
-			atomic_inc(&nh->nh_dev->refcnt);
+		if ((nh->nh_dev = FIB_RES_DEV(res)) == NULL)
+			goto out;
+		atomic_inc(&nh->nh_dev->refcnt);
+		err = -ENETDOWN;
+		if (!(nh->nh_dev->flags & IFF_UP))
+			goto out;
+		err = 0;
+out:
 		fib_res_put(&res);
+		return err;
 	} else {
 		struct in_device *in_dev;
 
@@ -869,11 +880,19 @@
 					 nh->nh_scope != scope) {
 					nh->nh_flags |= RTNH_F_DEAD;
 #ifdef CONFIG_IP_ROUTE_MULTIPATH
+					spin_lock_bh(&fib_multipath_lock);
 					fi->fib_power -= nh->nh_power;
 					nh->nh_power = 0;
+					spin_unlock_bh(&fib_multipath_lock);
 #endif
 					dead++;
 				}
+#ifdef CONFIG_IP_ROUTE_MULTIPATH
+				if (force > 1 && nh->nh_dev == dev) {
+					dead = fi->fib_nhs;
+					break;
+				}
+#endif
 			} endfor_nexthops(fi)
 			if (dead == fi->fib_nhs) {
 				fi->fib_flags |= RTNH_F_DEAD;
@@ -911,8 +930,10 @@
 			if (nh->nh_dev != dev || __in_dev_get(dev) == NULL)
 				continue;
 			alive++;
+			spin_lock_bh(&fib_multipath_lock);
 			nh->nh_power = 0;
 			nh->nh_flags &= ~RTNH_F_DEAD;
+			spin_unlock_bh(&fib_multipath_lock);
 		} endfor_nexthops(fi)
 
 		if (alive > 0) {
@@ -933,6 +954,7 @@
 	struct fib_info *fi = res->fi;
 	int w;
 
+	spin_lock_bh(&fib_multipath_lock);
 	if (fi->fib_power <= 0) {
 		int power = 0;
 		change_nexthops(fi) {
@@ -942,12 +964,12 @@
 			}
 		} endfor_nexthops(fi);
 		fi->fib_power = power;
-#if 1
 		if (power <= 0) {
-			printk(KERN_CRIT "impossible 777\n");
+			spin_unlock_bh(&fib_multipath_lock);
+			/* Race condition: route has just become dead. */
+			res->nh_sel = 0;
 			return;
 		}
-#endif
 	}
 
 
@@ -963,15 +985,15 @@
 				nh->nh_power--;
 				fi->fib_power--;
 				res->nh_sel = nhsel;
+				spin_unlock_bh(&fib_multipath_lock);
 				return;
 			}
 		}
 	} endfor_nexthops(fi);
 
-#if 1
-	printk(KERN_CRIT "impossible 888\n");
-#endif
-	return;
+	/* Race condition: route has just become dead. */
+	res->nh_sel = 0;
+	spin_unlock_bh(&fib_multipath_lock);
 }
 #endif