| Message ID | 1592030995-111190-1-git-send-email-geffrey.guo@huawei.com |
|---|---|
| State | Changes Requested |
| Delegated to: | David Miller |
| Headers | show |
| Series | net: Fix the arp error in some cases | expand |
On 6/13/20 12:49 AM, guodeqing wrote: > ie., > $ ifconfig eth0 6.6.6.6 netmask 255.255.255.0 > > $ ip rule add from 6.6.6.6 table 6666 without a default entry in table 6666 the lookup proceeds to the next table - which by default is the main table. > > $ ip route add 9.9.9.9 via 6.6.6.6 > > $ ping -I 6.6.6.6 9.9.9.9 > PING 9.9.9.9 (9.9.9.9) from 6.6.6.6 : 56(84) bytes of data. > > ^C > --- 9.9.9.9 ping statistics --- > 3 packets transmitted, 0 received, 100% packet loss, time 2079ms > > $ arp > Address HWtype HWaddress Flags Mask Iface > 6.6.6.6 (incomplete) eth0 > > The arp request address is error, this problem can be reproduced easily. > > Fixes: 3bfd847203c6("net: Use passed in table for nexthop lookups") > Signed-off-by: guodeqing <geffrey.guo@huawei.com> > --- > net/ipv4/fib_semantics.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c > index e53871e..1f75dc6 100644 > --- a/net/ipv4/fib_semantics.c > +++ b/net/ipv4/fib_semantics.c > @@ -1109,7 +1109,7 @@ static int fib_check_nh_v4_gw(struct net *net, struct fib_nh *nh, u32 table, > if (fl4.flowi4_scope < RT_SCOPE_LINK) > fl4.flowi4_scope = RT_SCOPE_LINK; > > - if (table) > + if (table && table != RT_TABLE_MAIN) > tbl = fib_get_table(net, table); > > if (tbl) > how does gateway validation when the route is installed affect arp resolution? you are missing something in explaining the problem you are seeing.
-----邮件原件----- 发件人: David Ahern [mailto:dsahern@gmail.com] 发送时间: Saturday, June 13, 2020 22:32 收件人: Guodeqing (A) <geffrey.guo@huawei.com>; davem@davemloft.net 抄送: kuznet@ms2.inr.ac.ru; netdev@vger.kernel.org; dsa@cumulusnetworks.com; kuba@kernel.org 主题: Re: [PATCH] net: Fix the arp error in some cases On 6/13/20 12:49 AM, guodeqing wrote: > ie., > $ ifconfig eth0 6.6.6.6 netmask 255.255.255.0 > > $ ip rule add from 6.6.6.6 table 6666 without a default entry in table 6666 the lookup proceeds to the next table - which by default is the main table. ---yes，if without the rule，this problem will not happen. Follow the steps: $ ifconfig eth0 6.6.6.6 netmask 255.255.255.0 $ ip route add 9.9.9.9 via 6.6.6.6 $ ping -I 6.6.6.6 9.9.9.9 And The arp request address is 9.9.9.9 and is right.(" gateway can be actually local interface address, * so that gatewayed route is direct") > > $ ip route add 9.9.9.9 via 6.6.6.6 > > $ ping -I 6.6.6.6 9.9.9.9 > PING 9.9.9.9 (9.9.9.9) from 6.6.6.6 : 56(84) bytes of data. > > ^C > --- 9.9.9.9 ping statistics --- > 3 packets transmitted, 0 received, 100% packet loss, time 2079ms > > $ arp > Address HWtype HWaddress Flags Mask Iface > 6.6.6.6 (incomplete) eth0 > > The arp request address is error, this problem can be reproduced easily. > > Fixes: 3bfd847203c6("net: Use passed in table for nexthop lookups") > Signed-off-by: guodeqing <geffrey.guo@huawei.com> > --- > net/ipv4/fib_semantics.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c index > e53871e..1f75dc6 100644 > --- a/net/ipv4/fib_semantics.c > +++ b/net/ipv4/fib_semantics.c > @@ -1109,7 +1109,7 @@ static int fib_check_nh_v4_gw(struct net *net, struct fib_nh *nh, u32 table, > if (fl4.flowi4_scope < RT_SCOPE_LINK) > fl4.flowi4_scope = RT_SCOPE_LINK; > > - if (table) > + if (table && table != RT_TABLE_MAIN) > tbl = fib_get_table(net, table); > > if (tbl) > how does gateway validation when the route is installed affect arp resolution? you are missing something in explaining the problem you are seeing. -- This problem can only happen in some cases,this 3bfd847203c6 patch will do the main table lookup error in some cases, and I think it should not do the main table lookup because the next function fib_lookup does the maintable lookup.
On Sat, 13 Jun 2020 14:49:55 +0800 guodeqing wrote: > ie., > $ ifconfig eth0 6.6.6.6 netmask 255.255.255.0 > > $ ip rule add from 6.6.6.6 table 6666 > > $ ip route add 9.9.9.9 via 6.6.6.6 > > $ ping -I 6.6.6.6 9.9.9.9 > PING 9.9.9.9 (9.9.9.9) from 6.6.6.6 : 56(84) bytes of data. > > ^C > --- 9.9.9.9 ping statistics --- Please don't put --- in the commit message like this, git will cut off the message here, since this is a footer separator. > 3 packets transmitted, 0 received, 100% packet loss, time 2079ms > > $ arp > Address HWtype HWaddress Flags Mask Iface > 6.6.6.6 (incomplete) eth0 > > The arp request address is error, this problem can be reproduced easily. > > Fixes: 3bfd847203c6("net: Use passed in table for nexthop lookups") > Signed-off-by: guodeqing <geffrey.guo@huawei.com>
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c index e53871e..1f75dc6 100644 --- a/net/ipv4/fib_semantics.c +++ b/net/ipv4/fib_semantics.c @@ -1109,7 +1109,7 @@ static int fib_check_nh_v4_gw(struct net *net, struct fib_nh *nh, u32 table, if (fl4.flowi4_scope < RT_SCOPE_LINK) fl4.flowi4_scope = RT_SCOPE_LINK; - if (table) + if (table && table != RT_TABLE_MAIN) tbl = fib_get_table(net, table); if (tbl)
ie., $ ifconfig eth0 6.6.6.6 netmask 255.255.255.0 $ ip rule add from 6.6.6.6 table 6666 $ ip route add 9.9.9.9 via 6.6.6.6 $ ping -I 6.6.6.6 9.9.9.9 PING 9.9.9.9 (9.9.9.9) from 6.6.6.6 : 56(84) bytes of data. ^C --- 9.9.9.9 ping statistics --- 3 packets transmitted, 0 received, 100% packet loss, time 2079ms $ arp Address HWtype HWaddress Flags Mask Iface 6.6.6.6 (incomplete) eth0 The arp request address is error, this problem can be reproduced easily. Fixes: 3bfd847203c6("net: Use passed in table for nexthop lookups") Signed-off-by: guodeqing <geffrey.guo@huawei.com> --- net/ipv4/fib_semantics.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)