[PATCH RFC net-next v4 03/11] vsock: add vsock net ns helpers

[Bobby Eshleman <bobbyeshleman@gmail.com>]

From: Bobby Eshleman <bobbyeshleman@meta.com>

Add helper functions for setting/getting vsock NS modes.  This commit is
in preparation for adding NS support to vsock.

Signed-off-by: Bobby Eshleman <bobbyeshleman@meta.com>
---
 include/net/af_vsock.h | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h
index d56e6e135158..e0b9e6732d53 100644
--- a/include/net/af_vsock.h
+++ b/include/net/af_vsock.h
@@ -10,6 +10,7 @@
 
 #include <linux/kernel.h>
 #include <linux/workqueue.h>
+#include <net/netns/vsock.h>
 #include <net/sock.h>
 #include <uapi/linux/vm_sockets.h>
 
@@ -256,4 +257,49 @@ static inline bool vsock_msgzerocopy_allow(const struct vsock_transport *t)
 {
 	return t->msgzerocopy_allow && t->msgzerocopy_allow();
 }
+
+extern struct net __vsock_global_net;
+static inline struct net *vsock_global_net(void)
+{
+	return &__vsock_global_net;
+}
+
+static inline u8 vsock_net_mode(struct net *net)
+{
+	u8 ret;
+
+	spin_lock_bh(&net->vsock.lock);
+	ret = net->vsock.ns_mode;
+	spin_unlock_bh(&net->vsock.lock);
+	return ret;
+}
+
+static inline void vsock_net_set_mode(struct net *net, u8 mode)
+{
+	spin_lock_bh(&net->vsock.lock);
+	net->vsock.ns_mode = mode | VSOCK_NS_MODE_WRITTEN_ONCE;
+	spin_unlock_bh(&net->vsock.lock);
+}
+
+/* Return true if mode has already been written once. Otherwise, return false. */
+static inline bool vsock_net_mode_can_set(struct net *net)
+{
+	bool ret;
+
+	spin_lock_bh(&net->vsock.lock);
+	ret = !(net->vsock.ns_mode & VSOCK_NS_MODE_WRITTEN_ONCE);
+	spin_unlock_bh(&net->vsock.lock);
+	return ret;
+}
+
+/* Return true if vsock net mode check passes. Otherwise, return false.
+ *
+ * Read more about modes in comment header of net/vmw_vsock/af_vsock.c.
+ */
+static inline bool vsock_net_check_mode(struct net *n1, struct net *n2)
+{
+	return net_eq(n1, n2) ||
+	       (vsock_net_mode(n1) & VSOCK_NS_MODE_GLOBAL &&
+		vsock_net_mode(n2) & VSOCK_NS_MODE_GLOBAL);
+}
 #endif /* __AF_VSOCK_H__ */

-- 
2.47.1