[PATCH net-next 1/5] mptcp: remove thmac from subflow ctx
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COLD17d
IN NET-NEXT: 1 (1M)
From: "Matthieu Baerts (NGI0)" <matttbe@kernel.org>
Date: 2026-09-26 15:30:52
Also in:
lkml, mptcp
Subsystem:
networking [general], networking [mptcp], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Matthieu Baerts, Mat Martineau, Linus Torvalds
Revision v1 of 2 in this series; 1 review trailer (1 from subsystem maintainers); queued in net-next as 0cb6910130a3 on 2026-09-30.
Revisions (2)
- v1 current
- v1
This entry is only used in subflow_finish_connect(). Instead, use the original value from mp_opt, and pass it to subflow_thmac_valid() to do the validation with the given truncated hmac. While at it, rename the variables in subflow_thmac_valid() to avoid confusions about the received one vs the expected one. Reviewed-by: Geliang Tang <geliang@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> --- net/mptcp/protocol.h | 1 - net/mptcp/subflow.c | 18 +++++++++--------- 2 files changed, 9 insertions(+), 10 deletions(-)
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index 0384d6a023f9..dd9957d334b6 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h@@ -593,7 +593,6 @@ struct mptcp_subflow_context { bool fully_established; /* path validated */ u32 lent_mem_frag; u32 remote_nonce; - u64 thmac; u32 local_nonce; u32 remote_token; union {
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index f0a6725d2c37..14aa82647c3d 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c@@ -408,20 +408,21 @@ static struct dst_entry *subflow_v6_route_req(const struct sock *sk, #endif /* validate received truncated hmac and create hmac for third ACK */ -static bool subflow_thmac_valid(struct mptcp_subflow_context *subflow) +static bool subflow_thmac_valid(struct mptcp_subflow_context *subflow, + u64 thmac) { u8 hmac[SHA256_DIGEST_SIZE]; - u64 thmac; + u64 expected_thmac; subflow_generate_hmac(subflow->remote_key, subflow->local_key, subflow->remote_nonce, subflow->local_nonce, hmac); - thmac = get_unaligned_be64(hmac); - pr_debug("subflow=%p, token=%u, thmac=%llu, subflow->thmac=%llu\n", - subflow, subflow->token, thmac, subflow->thmac); + expected_thmac = get_unaligned_be64(hmac); + pr_debug("subflow=%p, token=%u, expected_thmac=%llu, thmac=%llu\n", + subflow, subflow->token, expected_thmac, thmac); - return thmac == subflow->thmac; + return expected_thmac == thmac; } void mptcp_subflow_reset(struct sock *ssk)
@@ -575,14 +576,13 @@ static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb) } subflow->backup = mp_opt.backup; - subflow->thmac = mp_opt.thmac; subflow->remote_nonce = mp_opt.nonce; WRITE_ONCE(subflow->remote_id, mp_opt.join_id); pr_debug("subflow=%p, thmac=%llu, remote_nonce=%u backup=%d\n", - subflow, subflow->thmac, subflow->remote_nonce, + subflow, mp_opt.thmac, subflow->remote_nonce, subflow->backup); - if (!subflow_thmac_valid(subflow)) { + if (!subflow_thmac_valid(subflow, mp_opt.thmac)) { MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_JOINSYNACKMAC); subflow->reset_reason = MPTCP_RST_EMPTCP; goto do_reset;
--
2.55.0