mptcp: pm: validate mandatory ops

This patch adds a helper mptcp_pm_validate() to check whether required
ops are defined. It will be invoked in .validate of struct bpf_struct_ops.

Currently mandatory ops of mptcp_pm_ops are get_local_id and get_priority.

Signed-off-by: Geliang Tang <[email protected]>

Author: Geliang Tang

net/mptcp/pm.c

@@ -1045,8 +1045,24 @@ struct mptcp_pm_ops *mptcp_pm_find(const char *name)
 	return NULL;
 }
 
+int mptcp_pm_validate(struct mptcp_pm_ops *pm_ops)
+{
+	if (!pm_ops->get_local_id || !pm_ops->get_priority) {
+		pr_err("%s does not implement required ops\n", pm_ops->name);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 int mptcp_pm_register(struct mptcp_pm_ops *pm_ops)
 {
+	int ret;
+
+	ret = mptcp_pm_validate(pm_ops);
+	if (ret)
+		return ret;
+
 	spin_lock(&mptcp_pm_list_lock);
 	if (mptcp_pm_find(pm_ops->name)) {
 		spin_unlock(&mptcp_pm_list_lock);

net/mptcp/protocol.h

@@ -1059,6 +1059,7 @@ extern struct mptcp_pm_ops mptcp_pm_kernel;
 struct mptcp_pm_ops *mptcp_pm_find(const char *name);
 int mptcp_pm_register(struct mptcp_pm_ops *pm_ops);
 void mptcp_pm_unregister(struct mptcp_pm_ops *pm_ops);
+int mptcp_pm_validate(struct mptcp_pm_ops *pm_ops);
 
 void mptcp_userspace_pm_free_local_addr_list(struct mptcp_sock *msk);