On Wed, Dec 5, 2018 at 3:07 PM yupeng <[email protected]> wrote:
>
> after set SO_DONTROUTE to 1, the IP layer should not route packets if
> the dest IP address is not in link scope. But if the socket has cached
> the dst_entry, such packets would be routed until the sk_dst_cache
> expires. So we should clean the sk_dst_cache when a user set
> SO_DONTROUTE option. Below are server/client python scripts which
> could reprodue this issue:
>
> server side code:
> ==========================================================================
> import socket
> import struct
>
> s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
> s.bind(('0.0.0.0', 9000))
> s.listen(1)
> sock, addr = s.accept()
> sock.setsockopt(socket.SOL_SOCKET, socket.SO_DONTROUTE, struct.pack('i', 1))
> while True:
> data = sock.recv(1024) # here the sock.recv should not return anything
Why is that so ?
What is the relation of input path with the SO_DONTROUTE which is for TX ?
sk_dst_reset(sk) should not impact receive side ?
Thanks for providing a test !
> print(data)
> ==========================================================================
>
> client side code:
> ==========================================================================
> import socket
> import time
>
> s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
> s.connect(('server_address', 9000))
> while True:
> s.send(b'foo')
> print('send foo')
> time.sleep(1)
> ==========================================================================
>
> Signed-off-by: yupeng <[email protected]>
> ---
> net/core/sock.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/net/core/sock.c b/net/core/sock.c
> index f5bb89785e47..f00902c532cc 100644
> --- a/net/core/sock.c
> +++ b/net/core/sock.c
> @@ -700,6 +700,7 @@ int sock_setsockopt(struct socket *sock, int level, int
> optname,
> break;
> case SO_DONTROUTE:
> sock_valbool_flag(sk, SOCK_LOCALROUTE, valbool);
> + sk_dst_reset(sk);
> break;
> case SO_BROADCAST:
> sock_valbool_flag(sk, SOCK_BROADCAST, valbool);
> --
> 2.17.1
>
