[PATCH RFC net-next v4 09/12] vsock/loopback: add netns support

[Bobby Eshleman <bobbyeshleman@gmail.com>]

From: Bobby Eshleman <bobbyeshleman@meta.com>

Add NS support to vsock loopback. Sockets in a global mode netns
communicate with each other, regardless of namespace. Sockets in a local
mode netns may only communicate with other sockets within the same
namespace.

Signed-off-by: Bobby Eshleman <bobbyeshleman@meta.com>
---
 include/net/af_vsock.h         |  4 +++
 include/net/netns/vsock.h      |  3 +++
 net/vmw_vsock/af_vsock.c       |  8 +++++-
 net/vmw_vsock/vsock_loopback.c | 59 +++++++++++++++++++++++++++++++++++-------
 4 files changed, 63 insertions(+), 11 deletions(-)

diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h
index 0c0c351394de..aefff6e102e7 100644
--- a/include/net/af_vsock.h
+++ b/include/net/af_vsock.h
@@ -305,4 +305,8 @@ static inline bool vsock_net_check_mode(struct net *n1, struct net *n2)
 	       (vsock_net_mode(n1) == VSOCK_NET_MODE_GLOBAL &&
 		vsock_net_mode(n2) == VSOCK_NET_MODE_GLOBAL);
 }
+
+int vsock_loopback_init_net(struct net *net);
+void vsock_loopback_exit_net(struct net *net);
+
 #endif /* __AF_VSOCK_H__ */
diff --git a/include/net/netns/vsock.h b/include/net/netns/vsock.h
index 0bad4652815c..4420346e10a8 100644
--- a/include/net/netns/vsock.h
+++ b/include/net/netns/vsock.h
@@ -7,6 +7,8 @@
 #define VSOCK_NET_MODE_GLOBAL	1
 #define VSOCK_NET_MODE_LOCAL	(1 << 1)
 
+struct vsock_loopback;
+
 struct netns_vsock {
 	struct ctl_table_header *vsock_hdr;
 	spinlock_t lock;
@@ -14,5 +16,6 @@ struct netns_vsock {
 	/* protected by lock */
 	u8 ns_mode;
 	bool written;
+	struct vsock_loopback *loopback;
 };
 #endif /* __NET_NET_NAMESPACE_VSOCK_H */
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index c69c2db03162..5689ce7d5843 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -2778,9 +2778,12 @@ static __net_init int vsock_sysctl_init_net(struct net *net)
 {
 	vsock_net_init(net);
 
-	if (vsock_sysctl_register(net))
+	if (vsock_loopback_init_net(net))
 		return -ENOMEM;
 
+	if (vsock_sysctl_register(net))
+		goto err_loopback;
+
 #ifdef CONFIG_PROC_FS
 	if (!proc_create_net_single_write("vsock_ns_mode", 0644, net->proc_net,
 					  vsock_proc_ns_mode_show,
@@ -2793,12 +2796,15 @@ static __net_init int vsock_sysctl_init_net(struct net *net)
 
 err_sysctl:
 	vsock_sysctl_unregister(net);
+err_loopback:
+	vsock_loopback_exit_net(net);
 	return -ENOMEM;
 }
 
 static __net_exit void vsock_sysctl_exit_net(struct net *net)
 {
 	vsock_sysctl_unregister(net);
+	vsock_loopback_exit_net(net);
 }
 
 static struct pernet_operations vsock_sysctl_ops __net_initdata = {
diff --git a/net/vmw_vsock/vsock_loopback.c b/net/vmw_vsock/vsock_loopback.c
index 6e78927a598e..4fc07e3a1d2b 100644
--- a/net/vmw_vsock/vsock_loopback.c
+++ b/net/vmw_vsock/vsock_loopback.c
@@ -28,8 +28,19 @@ static u32 vsock_loopback_get_local_cid(void)
 
 static int vsock_loopback_send_pkt(struct sk_buff *skb)
 {
-	struct vsock_loopback *vsock = &the_vsock_loopback;
+	struct vsock_loopback *vsock;
 	int len = skb->len;
+	struct net *net;
+
+	if (skb->sk)
+		net = sock_net(skb->sk);
+	else
+		net = NULL;
+
+	if (net && net->vsock.ns_mode == VSOCK_NET_MODE_LOCAL)
+		vsock = net->vsock.loopback;
+	else
+		vsock = &the_vsock_loopback;
 
 	virtio_vsock_skb_queue_tail(&vsock->pkt_queue, skb);
 	queue_work(vsock->workqueue, &vsock->pkt_work);
@@ -46,7 +57,7 @@ static int vsock_loopback_cancel_pkt(struct vsock_sock *vsk)
 	return 0;
 }
 
-static bool vsock_loopback_seqpacket_allow(u32 remote_cid);
+static bool vsock_loopback_seqpacket_allow(struct vsock_sock *vsk, u32 remote_cid);
 static bool vsock_loopback_msgzerocopy_allow(void)
 {
 	return true;
@@ -106,7 +117,7 @@ static struct virtio_transport loopback_transport = {
 	.send_pkt = vsock_loopback_send_pkt,
 };
 
-static bool vsock_loopback_seqpacket_allow(u32 remote_cid)
+static bool vsock_loopback_seqpacket_allow(struct vsock_sock *vsk, u32 remote_cid)
 {
 	return true;
 }
@@ -134,27 +145,55 @@ static void vsock_loopback_work(struct work_struct *work)
 	}
 }
 
-static int __init vsock_loopback_init(void)
+static int vsock_loopback_init_vsock(struct vsock_loopback *vsock)
 {
-	struct vsock_loopback *vsock = &the_vsock_loopback;
-	int ret;
-
 	vsock->workqueue = alloc_workqueue("vsock-loopback", 0, 0);
 	if (!vsock->workqueue)
 		return -ENOMEM;
 
 	skb_queue_head_init(&vsock->pkt_queue);
 	INIT_WORK(&vsock->pkt_work, vsock_loopback_work);
+	return 0;
+}
+
+static void vsock_loopback_deinit_vsock(struct vsock_loopback *vsock)
+{
+	destroy_workqueue(vsock->workqueue);
+}
+
+int vsock_loopback_init_net(struct net *net)
+{
+	net->vsock.loopback = kmalloc(GFP_KERNEL, sizeof(struct vsock_loopback));
+	if (!net->vsock.loopback)
+		return -ENOMEM;
+
+	return vsock_loopback_init_vsock(net->vsock.loopback);
+}
+
+void vsock_loopback_exit_net(struct net *net)
+{
+	vsock_loopback_deinit_vsock(net->vsock.loopback);
+	kfree(net->vsock.loopback);
+}
+
+static int __init vsock_loopback_init(void)
+{
+	struct vsock_loopback *vsock = &the_vsock_loopback;
+	int ret;
+
+	ret = vsock_loopback_init_vsock(vsock);
+	if (ret < 0)
+		return ret;
 
 	ret = vsock_core_register(&loopback_transport.transport,
 				  VSOCK_TRANSPORT_F_LOCAL);
 	if (ret)
-		goto out_wq;
+		goto out_deinit;
 
 	return 0;
 
-out_wq:
-	destroy_workqueue(vsock->workqueue);
+out_deinit:
+	vsock_loopback_deinit_vsock(vsock);
 	return ret;
 }
 

-- 
2.47.3