On 8/22/20 1:46 AM, guodeqing wrote:
> ie.,
> $ ifconfig eth0 9.9.9.9 netmask 255.255.255.0
>
> $ ping -I lo 9.9.9.9
> ping: Warning: source address might be selected on device other than lo.
> PING 9.9.9.9 (9.9.9.9) from 9.9.9.9 lo: 56(84) bytes of data.
>
> 4 packets transmitted, 0 received, 100% packet loss, time 3068ms
>
> This is because the return value of __raw_v4_lookup in raw_v4_input
> is null, the packets cannot be sent to the ping application.
> The reason of the __raw_v4_lookup failure is that sk_bound_dev_if and
> dif/sdif are not equal in raw_sk_bound_dev_eq.
>
> Here I add a check of whether the sk_bound_dev_if is LOOPBACK_IFINDEX
> to solve this problem.
>
> Fixes: 19e4e768064a8 ("ipv4: Fix raw socket lookup for local traffic")
> Signed-off-by: guodeqing <geffrey....@huawei.com>
> ---
> include/net/inet_sock.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h
> index a3702d1..7707b1d 100644
> --- a/include/net/inet_sock.h
> +++ b/include/net/inet_sock.h
> @@ -144,7 +144,7 @@ static inline bool inet_bound_dev_eq(bool l3mdev_accept,
> int bound_dev_if,
> {
> if (!bound_dev_if)
> return !sdif || l3mdev_accept;
> - return bound_dev_if == dif || bound_dev_if == sdif;
> + return bound_dev_if == dif || bound_dev_if == sdif || bound_dev_if ==
> LOOPBACK_IFINDEX;
> }
>
> struct inet_cork {
>
this is used by more than just raw socket lookups.
