Re: PROBLEM: 2.4.37.9 destroying an Ethernet interface with permanent NUD leaves the kernels with undestroyable interfaces when ATM is compiled in

[Sylvain Rochet]

Hi,

On Wed, Apr 07, 2010 at 10:23:39PM +0200, Sylvain Rochet wrote:
> Hi,
> 
> (...)
> 
> I changed the family of the ATM table to AF_ATMPVC, of course it fixes 
> the issue but I guess this is the wrong way to fix that.

Finally made a patch that follows what Linux 2.6 does, which consists of 
having "netlink" and "no-netlink" tables.

Sylvain
diff -Nru linux-2.4.36.6.a/include/net/neighbour.h linux-2.4.36.6.b/include/net/neighbour.h
--- linux-2.4.36.6.a/include/net/neighbour.h	2008-06-06 16:25:34.000000000 +0000
+++ linux-2.4.36.6.b/include/net/neighbour.h	2010-04-08 13:36:12.000000000 +0000
@@ -192,6 +192,7 @@
 };
 
 extern void			neigh_table_init(struct neigh_table *tbl);
+extern void			neigh_table_init_no_netlink(struct neigh_table *tbl);
 extern int			neigh_table_clear(struct neigh_table *tbl);
 extern struct neighbour *	neigh_lookup(struct neigh_table *tbl,
 					     const void *pkey,
diff -Nru linux-2.4.36.6.a/net/atm/clip.c linux-2.4.36.6.b/net/atm/clip.c
--- linux-2.4.36.6.a/net/atm/clip.c	2008-06-06 16:25:34.000000000 +0000
+++ linux-2.4.36.6.b/net/atm/clip.c	2010-04-08 13:35:09.000000000 +0000
@@ -752,7 +752,7 @@
 
 static int __init atm_clip_init(void)
 {
-	neigh_table_init(&clip_tbl);
+	neigh_table_init_no_netlink(&clip_tbl);
 
 	clip_tbl_hook = &clip_tbl;
 	atm_clip_ops_set(&__atm_clip_ops);
diff -Nru linux-2.4.36.6.a/net/core/neighbour.c linux-2.4.36.6.b/net/core/neighbour.c
--- linux-2.4.36.6.a/net/core/neighbour.c	2008-06-06 16:25:34.000000000 +0000
+++ linux-2.4.36.6.b/net/core/neighbour.c	2010-04-08 13:33:40.000000000 +0000
@@ -1248,7 +1248,7 @@
 }
 
 
-void neigh_table_init(struct neigh_table *tbl)
+void neigh_table_init_no_netlink(struct neigh_table *tbl)
 {
 	unsigned long now = jiffies;
 	unsigned long phsize;
@@ -1302,10 +1302,27 @@
 
 	tbl->last_flush = now;
 	tbl->last_rand = now + tbl->parms.reachable_time*20;
+}
+
+void neigh_table_init(struct neigh_table *tbl)
+{
+	struct neigh_table *tmp;
+
+	neigh_table_init_no_netlink(tbl);
 	write_lock(&neigh_tbl_lock);
-	tbl->next = neigh_tables;
-	neigh_tables = tbl;
+	for (tmp = neigh_tables; tmp; tmp = tmp->next) {
+		if (tmp->family == tbl->family)
+		break;
+	}
+	tbl->next       = neigh_tables;
+	neigh_tables    = tbl;
 	write_unlock(&neigh_tbl_lock);
+
+	if (unlikely(tmp)) {
+		printk(KERN_ERR "NEIGH: Registering multiple tables for "
+			"family %d\n", tbl->family);
+		dump_stack();
+	}
 }
 
 int neigh_table_clear(struct neigh_table *tbl)

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