From: Geliang Tang tanggeliang@kylinos.cn
commit f5ce0714623cffd00bf2a83e890d09c609b7f50a upstream.
When add_addr_timeout was set to 0, this caused the ADD_ADDR to be retransmitted immediately, which looks like a buggy behaviour. Instead, interpret 0 as "no retransmissions needed".
The documentation is updated to explicitly state that setting the timeout to 0 disables retransmission.
Fixes: 93f323b9cccc ("mptcp: add a new sysctl add_addr_timeout") Cc: stable@vger.kernel.org Suggested-by: Matthieu Baerts matttbe@kernel.org Signed-off-by: Geliang Tang tanggeliang@kylinos.cn Reviewed-by: Matthieu Baerts (NGI0) matttbe@kernel.org Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org Link: https://patch.msgid.link/20250815-net-mptcp-misc-fixes-6-17-rc2-v1-5-521fe99... Signed-off-by: Jakub Kicinski kuba@kernel.org [ Before commit e4c28e3d5c09 ("mptcp: pm: move generic PM helpers to pm.c"), mptcp_pm_alloc_anno_list() was in pm_netlink.c. The same patch can be applied there without conflicts. ] Signed-off-by: Matthieu Baerts (NGI0) matttbe@kernel.org --- Documentation/networking/mptcp-sysctl.rst | 2 ++ net/mptcp/pm_netlink.c | 13 ++++++++++--- 2 files changed, 12 insertions(+), 3 deletions(-)
diff --git a/Documentation/networking/mptcp-sysctl.rst b/Documentation/networking/mptcp-sysctl.rst index 213510698014..722b4395e91b 100644 --- a/Documentation/networking/mptcp-sysctl.rst +++ b/Documentation/networking/mptcp-sysctl.rst @@ -20,6 +20,8 @@ add_addr_timeout - INTEGER (seconds) resent to an MPTCP peer that has not acknowledged a previous ADD_ADDR message.
+ Do not retransmit if set to 0. + The default value matches TCP_RTO_MAX. This is a per-namespace sysctl.
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c index 59d6e701d854..cf9244a3644f 100644 --- a/net/mptcp/pm_netlink.c +++ b/net/mptcp/pm_netlink.c @@ -304,6 +304,7 @@ static void mptcp_pm_add_timer(struct timer_list *timer) struct mptcp_pm_add_entry *entry = from_timer(entry, timer, add_timer); struct mptcp_sock *msk = entry->sock; struct sock *sk = (struct sock *)msk; + unsigned int timeout;
pr_debug("msk=%p\n", msk);
@@ -321,6 +322,10 @@ static void mptcp_pm_add_timer(struct timer_list *timer) goto out; }
+ timeout = mptcp_get_add_addr_timeout(sock_net(sk)); + if (!timeout) + goto out; + spin_lock_bh(&msk->pm.lock);
if (!mptcp_pm_should_add_signal_addr(msk)) { @@ -332,7 +337,7 @@ static void mptcp_pm_add_timer(struct timer_list *timer)
if (entry->retrans_times < ADD_ADDR_RETRANS_MAX) sk_reset_timer(sk, timer, - jiffies + mptcp_get_add_addr_timeout(sock_net(sk))); + jiffies + timeout);
spin_unlock_bh(&msk->pm.lock);
@@ -374,6 +379,7 @@ bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk, struct mptcp_pm_add_entry *add_entry = NULL; struct sock *sk = (struct sock *)msk; struct net *net = sock_net(sk); + unsigned int timeout;
lockdep_assert_held(&msk->pm.lock);
@@ -398,8 +404,9 @@ bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk,
timer_setup(&add_entry->add_timer, mptcp_pm_add_timer, 0); reset_timer: - sk_reset_timer(sk, &add_entry->add_timer, - jiffies + mptcp_get_add_addr_timeout(net)); + timeout = mptcp_get_add_addr_timeout(net); + if (timeout) + sk_reset_timer(sk, &add_entry->add_timer, jiffies + timeout);
return true; }