[PATCH net-next 3/6] vsock: add local transport support in the vsock core

Stefano Garzarella
2019-11-19T11:02:09Z

This patch allows to register a transport able to handle
local communication (loopback).

Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
---
include/net/af_vsock.h | 2 ++
net/vmw_vsock/af_vsock.c | 17 ++++++++++++++++-
2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h
index 4206dc6d813f..b1c717286993 100644
--- a/include/net/af_vsock.h
+++ b/include/net/af_vsock.h
@@ -98,6 +98,8 @@ struct vsock_transport_send_notify_data {
#define VSOCK_TRANSPORT_F_G2H 0x00000002
/* Transport provides DGRAM communication */
#define VSOCK_TRANSPORT_F_DGRAM 0x00000004
+/* Transport provides local (loopback) communication */
+#define VSOCK_TRANSPORT_F_LOCAL 0x00000008

struct vsock_transport {
struct module *module;
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index cc8659838bf2..c9e5bad59dc1 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -136,6 +136,8 @@ static const struct vsock_transport *transport_h2g;
static const struct vsock_transport *transport_g2h;
/* Transport used for DGRAM communication */
static const struct vsock_transport *transport_dgram;
+/* Transport used for local communication */
+static const struct vsock_transport *transport_local;
static DEFINE_MUTEX(vsock_register_mutex);

/**** UTILS ****/
@@ -2130,7 +2132,7 @@ EXPORT_SYMBOL_GPL(vsock_core_get_transport);

int vsock_core_register(const struct vsock_transport *t, int features)
{
- const struct vsock_transport *t_h2g, *t_g2h, *t_dgram;
+ const struct vsock_transport *t_h2g, *t_g2h, *t_dgram, *t_local;
int err = mutex_lock_interruptible(&vsock_register_mutex);

if (err)
@@ -2139,6 +2141,7 @@ int vsock_core_register(const struct vsock_transport *t, int features)
t_h2g = transport_h2g;
t_g2h = transport_g2h;
t_dgram = transport_dgram;
+ t_local = transport_local;

if (features & VSOCK_TRANSPORT_F_H2G) {
if (t_h2g) {
@@ -2164,9 +2167,18 @@ int vsock_core_register(const struct vsock_transport *t, int features)
t_dgram = t;
}

+ if (features & VSOCK_TRANSPORT_F_LOCAL) {
+ if (t_local) {
+ err = -EBUSY;
+ goto err_busy;
+ }
+ t_local = t;
+ }
+
transport_h2g = t_h2g;
transport_g2h = t_g2h;
transport_dgram = t_dgram;
+ transport_local = t_local;

err_busy:
mutex_unlock(&vsock_register_mutex);
@@ -2187,6 +2199,9 @@ void vsock_core_unregister(const struct vsock_transport *t)
if (transport_dgram == t)
transport_dgram = NULL;

+ if (transport_local == t)
+ transport_local = NULL;
+
mutex_unlock(&vsock_register_mutex);
}
EXPORT_SYMBOL_GPL(vsock_core_unregister);
--
2.21.0