ipv4: tcp: fix TOS value in ACK messages sent from TIME_WAIT
There is a long standing bug in linux tcp stack, about ACK messages sent
on behalf of TIME_WAIT sockets.
In the IP header of the ACK message, we choose to reflect TOS field of
incoming message, and this might break some setups.
Example of things that were broken :
- Routing using TOS as a selector
- Firewalls
- Trafic classification / shaping
We now remember in timewait structure the inet tos field and use it in
ACK generation, and route lookup.
Notes :
- We still reflect incoming TOS in RST messages.
- We could extend MuraliRaja Muniraju patch to report TOS value in
netlink messages for TIME_WAIT sockets.
- A patch is needed for IPv6
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/ip.h b/include/net/ip.h
index c7e066a..eca0ef7 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -165,6 +165,7 @@
int csumoffset; /* u16 offset of csum in iov[0].iov_base */
/* -1 if not needed */
int bound_dev_if;
+ u8 tos;
};
#define IP_REPLY_ARG_NOSRCCHECK 1
@@ -175,7 +176,7 @@
}
void ip_send_reply(struct sock *sk, struct sk_buff *skb, __be32 daddr,
- struct ip_reply_arg *arg, unsigned int len);
+ const struct ip_reply_arg *arg, unsigned int len);
struct ipv4_config {
int log_martians;