mptcp: remove thmac from subflow ctx

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>
Link: https://patch.msgid.link/20260926-net-next-mptcp-misc-feat-7-4-v1-1-67af4ab37406@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Matthieu Baerts (NGI0) authored and Jakub Kicinski committed 2026-09-29 19:09:18 -07:00
1 parent 3e6a0e83c9
commit 0cb6910130
2 files changed
+9 -10

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-1
View File
@@ -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 {
+9 -9
View File
@@ -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;