diff options
| author |   Michal Kalderon <mkalderon@marvell.com> | 2021-08-08 04:30:39 -0700 |
|---|---|---|
| committer |   Florin Coras <florin.coras@gmail.com> | 2021-10-25 15:46:23 +0000 |
| commit | 3effadc66ff8acb2e5c83645faec411de59332c2 (patch) | |
| tree | 8fe4e24bb21f471072a48f795f0efd8e0bc2e853 /src/vnet/tcp/tcp.c | |
| parent | 3265ec8cb12d94e91a38ac377e78970eb032d88c (diff) | |
tcp: fix: TCP timewait port reuse rfc compliance
This patch provides a fix for early-kill of timewait sockets that is based on
rfc's 1122, 6191.
The following commits provided a solution for port re-use. However, they
are not fully compliant with rfc 1122 4.2.2.13 ( Closing a connection )
and rfc 6191 (Reducing the TIME-WAIT State Using TCP Timestamps)
commit b092b77cf238ba ("tcp: Enable TCP timewait port use") introduced
a significant improvement by enabling TCP timewait port re-use.
commit ee1cb469b2dd ("tcp: fix port reuse with multiple listeners") fixed
usage of the wrong value for connection_index when searching for a
listener, by storing the state in tcp.flags.
Implementation details:
When a SYN is received during time-wait state, the code
checks whether all the requirements for accepting the SYN packet are
met. If they aren't, the SYN can't be accepted and the packet is dropped,
otherwise, connection is deleted and a new connection with same port
is opened.
Type: fix
Signed-off-by: Ofer Heifetz <oferh@marvell.com>
Signed-off-by: Yuval Caduri <cyuval@marvell.com>
Signed-off-by: Michal Kalderon <mkalderon@marvell.com>
Change-Id: I38a33c6e321c760d45ebec9154399e1c90dd0250
Diffstat (limited to 'src/vnet/tcp/tcp.c')
| -rw-r--r-- | src/vnet/tcp/tcp.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/src/vnet/tcp/tcp.c b/src/vnet/tcp/tcp.c index 62267bbdd1f..4825bf62856 100644 --- a/src/vnet/tcp/tcp.c +++ b/src/vnet/tcp/tcp.c @@ -702,7 +702,13 @@ tcp_init_snd_vars (tcp_connection_t * tc) tcp_update_time_now (tcp_get_worker (vlib_get_thread_index ())); tcp_init_rcv_mss (tc); - tc->iss = tcp_generate_random_iss (tc); + /* + * In special case of early-kill of timewait socket, the iss will already + * be initialized to ensure it is greater than the last incarnation of the + * connection. see syn_during_timewait() for more details. + */ + if (!tc->iss) + tc->iss = tcp_generate_random_iss (tc); tc->snd_una = tc->iss; tc->snd_nxt = tc->iss + 1; tc->srtt = 0.1 * THZ; /* 100 ms */ |