diff mbox series

[mptcp-next,v5,1/8] mptcp: bypass in-kernel PM restrictions for non-kernel PMs

Message ID 20220203072508.3072309-2-kishen.maloor@intel.com (mailing list archive)
State Superseded, archived
Headers show
Series mptcp: fixes and enhancements related to path management | expand

Checks

Context Check Description
matttbe/checkpatch success total: 0 errors, 0 warnings, 0 checks, 52 lines checked
matttbe/build success Build and static analysis OK
matttbe/KVM_Validation__normal warning Unstable: 1 failed test(s): selftest_mptcp_join
matttbe/KVM_Validation__debug warning Unstable: 2 failed test(s): selftest_diag selftest_mptcp_join

Commit Message

Kishen Maloor Feb. 3, 2022, 7:25 a.m. UTC 
Current limits on the # of addresses/subflows must apply only to
in-kernel PM managed sockets. Thus this change removes such
restrictions for connections overseen by non-kernel (e.g. userspace)
PMs.

This change also ensures that the kernel does not record stats inside
struct mptcp_pm_data updated along kernel code paths when exercised
by non-kernel PMs.

Signed-off-by: Kishen Maloor <kishen.maloor@intel.com>
---
v4: rephrased commit message, add API mptcp_pm_is_kernel(), bypass
accounting fo non-kernel PM managed connections
---
 net/mptcp/pm.c         | 6 +++++-
 net/mptcp/pm_netlink.c | 3 +++
 net/mptcp/protocol.h   | 9 +++++++--
 net/mptcp/subflow.c    | 3 ++-
 4 files changed, 17 insertions(+), 4 deletions(-)
diff mbox series

Patch

diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index 1f8878cc29e3..3e053b759181 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -87,6 +87,9 @@  bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk)
 	unsigned int subflows_max;
 	int ret = 0;
 
+	if (!mptcp_pm_is_kernel(msk))
+		return true;
+
 	subflows_max = mptcp_pm_get_subflows_max(msk);
 
 	pr_debug("msk=%p subflows=%d max=%d allow=%d", msk, pm->subflows,
@@ -179,7 +182,8 @@  void mptcp_pm_subflow_check_next(struct mptcp_sock *msk, const struct sock *ssk,
 	bool update_subflows;
 
 	update_subflows = (ssk->sk_state == TCP_CLOSE) &&
-			  (subflow->request_join || subflow->mp_join);
+			  (subflow->request_join || subflow->mp_join) &&
+			  mptcp_pm_is_kernel(msk);
 	if (!READ_ONCE(pm->work_pending) && !update_subflows)
 		return;
 
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index 93800f32fcb6..bf24c1a74e1d 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -795,6 +795,9 @@  static void mptcp_pm_nl_rm_addr_or_subflow(struct mptcp_sock *msk,
 		if (!removed)
 			continue;
 
+		if (!mptcp_pm_is_kernel(msk))
+			continue;
+
 		if (rm_type == MPTCP_MIB_RMADDR) {
 			msk->pm.add_addr_accepted--;
 			WRITE_ONCE(msk->pm.accept_addr, true);
diff --git a/net/mptcp/protocol.h b/net/mptcp/protocol.h
index f37f087caab3..ac8b57d4f853 100644
--- a/net/mptcp/protocol.h
+++ b/net/mptcp/protocol.h
@@ -804,9 +804,14 @@  static inline bool mptcp_pm_should_rm_signal(struct mptcp_sock *msk)
 	return READ_ONCE(msk->pm.addr_signal) & BIT(MPTCP_RM_ADDR_SIGNAL);
 }
 
-static inline bool mptcp_pm_is_userspace(struct mptcp_sock *msk)
+static inline bool mptcp_pm_is_userspace(const struct mptcp_sock *msk)
 {
-	return READ_ONCE(msk->pm.pm_type) != MPTCP_PM_TYPE_KERNEL;
+	return READ_ONCE(msk->pm.pm_type) == MPTCP_PM_TYPE_USERSPACE;
+}
+
+static inline bool mptcp_pm_is_kernel(const struct mptcp_sock *msk)
+{
+	return READ_ONCE(msk->pm.pm_type) == MPTCP_PM_TYPE_KERNEL;
 }
 
 static inline unsigned int mptcp_add_addr_len(int family, bool echo, bool port)
diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c
index 88ee94adc38c..8c25a1122bfd 100644
--- a/net/mptcp/subflow.c
+++ b/net/mptcp/subflow.c
@@ -62,7 +62,8 @@  static void subflow_generate_hmac(u64 key1, u64 key2, u32 nonce1, u32 nonce2,
 static bool mptcp_can_accept_new_subflow(const struct mptcp_sock *msk)
 {
 	return mptcp_is_fully_established((void *)msk) &&
-	       READ_ONCE(msk->pm.accept_subflow);
+		(!mptcp_pm_is_kernel(msk) ||
+		READ_ONCE(msk->pm.accept_subflow));
 }
 
 /* validate received token and create truncated hmac and nonce for SYN-ACK */