diff options
| author | Davide Caratti <dcaratti@redhat.com> | 2020-10-06 18:26:17 +0200 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2020-10-09 08:25:48 -0700 |
| commit | 37198e93ced70733f0b993dff28b7c33857e254f (patch) | |
| tree | 5efe9e0415abf424ed26afd3563052862864ebe4 /net | |
| parent | 0da1ccbbefb662915228bc17e1c7d4ad28b3ddab (diff) | |
| download | linux-37198e93ced70733f0b993dff28b7c33857e254f.tar.bz2 | |
net: mptcp: make DACK4/DACK8 usage consistent among all subflows
using packetdrill it's possible to observe the same MPTCP DSN being acked
by different subflows with DACK4 and DACK8. This is in contrast with what
specified in RFC8684 ยง3.3.2: if an MPTCP endpoint transmits a 64-bit wide
DSN, it MUST be acknowledged with a 64-bit wide DACK. Fix 'use_64bit_ack'
variable to make it a property of MPTCP sockets, not TCP subflows.
Fixes: a0c1d0eafd1e ("mptcp: Use 32-bit DATA_ACK when possible")
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/mptcp/options.c | 2 | ||||
| -rw-r--r-- | net/mptcp/protocol.h | 2 | ||||
| -rw-r--r-- | net/mptcp/subflow.c | 3 |
3 files changed, 3 insertions, 4 deletions
diff --git a/net/mptcp/options.c b/net/mptcp/options.c index 888bbbbb3e8a..9d7fa93fe0cf 100644 --- a/net/mptcp/options.c +++ b/net/mptcp/options.c @@ -516,7 +516,7 @@ static bool mptcp_established_options_dss(struct sock *sk, struct sk_buff *skb, return ret; } - if (subflow->use_64bit_ack) { + if (READ_ONCE(msk->use_64bit_ack)) { ack_size = TCPOLEN_MPTCP_DSS_ACK64; opts->ext_copy.data_ack = READ_ONCE(msk->ack_seq); opts->ext_copy.ack64 = 1; diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h index 20f04ac85409..285dd8b2b43a 100644 --- a/net/mptcp/protocol.h +++ b/net/mptcp/protocol.h @@ -202,6 +202,7 @@ struct mptcp_sock { bool fully_established; bool rcv_data_fin; bool snd_data_fin_enable; + bool use_64bit_ack; /* Set when we received a 64-bit DSN */ spinlock_t join_list_lock; struct work_struct work; struct list_head conn_list; @@ -294,7 +295,6 @@ struct mptcp_subflow_context { backup : 1, data_avail : 1, rx_eof : 1, - use_64bit_ack : 1, /* Set when we received a 64-bit DSN */ can_ack : 1; /* only after processing the remote a key */ u32 remote_nonce; u64 thmac; diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index 6f035af1c9d2..91bef7bfffa6 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -769,12 +769,11 @@ static enum mapping_status get_mapping_status(struct sock *ssk, if (!mpext->dsn64) { map_seq = expand_seq(subflow->map_seq, subflow->map_data_len, mpext->data_seq); - subflow->use_64bit_ack = 0; pr_debug("expanded seq=%llu", subflow->map_seq); } else { map_seq = mpext->data_seq; - subflow->use_64bit_ack = 1; } + WRITE_ONCE(mptcp_sk(subflow->conn)->use_64bit_ack, !!mpext->dsn64); if (subflow->map_valid) { /* Allow replacing only with an identical map */ |