Re: [PATCH] net: ipv6: fix __rt6_purge_dflt_routers when forwarding is not set on all ifaces
From: Eric Dumazet <edumazet@google.com>
Date: 2020-09-01 07:56:44
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On Tue, Sep 1, 2020 at 8:58 AM Brian Vazquez [off-list ref] wrote:
The problem is exposed when the system has multiple ifaces and
forwarding is enabled on a subset of them, __rt6_purge_dflt_routers will
clean the default route on all the ifaces which is not desired.
This patches fixes that by cleaning only the routes where the iface has
forwarding enabled.
Fixes: 830218c1add1 ("net: ipv6: Fix processing of RAs in presence of VRF")quoted hunk ↗ jump to hunk
Cc: David Ahern <redacted> Signed-off-by: Brian Vazquez <redacted> --- net/ipv6/route.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 5e7e25e2523a..41181cd489ea 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c@@ -4283,6 +4283,7 @@ static void __rt6_purge_dflt_routers(struct net *net, struct fib6_table *table) { struct fib6_info *rt; + bool deleted = false; restart: rcu_read_lock();@@ -4291,16 +4292,19 @@ static void __rt6_purge_dflt_routers(struct net *net, struct inet6_dev *idev = dev ? __in6_dev_get(dev) : NULL; if (rt->fib6_flags & (RTF_DEFAULT | RTF_ADDRCONF) && - (!idev || idev->cnf.accept_ra != 2) && + (!idev || (idev->cnf.forwarding == 1 && + idev->cnf.accept_ra != 2)) && fib6_info_hold_safe(rt)) { rcu_read_unlock(); ip6_del_rt(net, rt, false); + deleted = true; goto restart; } } rcu_read_unlock(); - table->flags &= ~RT6_TABLE_HAS_DFLT_ROUTER; + if (deleted) + table->flags &= ~RT6_TABLE_HAS_DFLT_ROUTER;
This seems wrong : We want to keep the flag set if at least one candidate route has not been deleted, so that next time rt6_purge_dflt_routers() is called, we can call __rt6_purge_dflt_routers() ?