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;
}
--
2.47.3On Tue, Aug 05, 2025 at 02:49:17PM -0700, Bobby Eshleman wrote:
> 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>
...
> diff --git a/net/vmw_vsock/vsock_loopback.c b/net/vmw_vsock/vsock_loopback.c
...
> @@ -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);
This change needs to be squashed into
PATCH 3/12 vsock: add netns to af_vsock core
To avoid build breakage.
Likewise with the other change to vsock_loopback_seqpacket_allow below.
And I think also for a number of other changes made by PATCH 3/12.
Please make sure that patches don't introduce transient build failures.
It breaks bisection.
On the topic of vsock_loopback_seqpacket_allow, also:
* Please line wrap this so that the code is 80 columns wide or less,
as is still preferred for Networking code.
Flagged by checkpatch.pl --max-line-length=80
* Can we move the definition of vsock_loopback_seqpacket_allow() here?
The function itself is is trivial. And doing so would avoid a forward
declaration.
> static bool vsock_loopback_msgzerocopy_allow(void)
> {
> return true;
...
> +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);
> +}
I think EXPORT_SYMBOL_GPL is needed for both vsock_loopback_exit_net and
vsock_loopback_init_net for the case where CONFIG_VSOCKETS=m
Also, in Kconfig VSOCKETS_LOOPBACK depends on VSOCKETS. But this code adds
a reverse dependency. As it stands it's possible to configure VSOCKETS
without VSOCKETS_LOOPBACK, which will not compile.
Perhaps stub implementations of vsock_loopback_init_net and
vsock_loopback_exit_net should be implemented in af_vsock.h if
VSOCKETS_LOOPBACK is not enabled?
...
--
pw-bot: changes-requested
On Wed, Aug 06, 2025 at 08:12:39PM +0100, Simon Horman wrote:
> On Tue, Aug 05, 2025 at 02:49:17PM -0700, Bobby Eshleman wrote:
> > From: Bobby Eshleman <bobbyeshleman@meta.com>
> >
...
>
> This change needs to be squashed into
> PATCH 3/12 vsock: add netns to af_vsock core
>
> To avoid build breakage.
>
> Likewise with the other change to vsock_loopback_seqpacket_allow below.
> And I think also for a number of other changes made by PATCH 3/12.
>
> Please make sure that patches don't introduce transient build failures.
> It breaks bisection.
Will do, thanks!
>
>
> On the topic of vsock_loopback_seqpacket_allow, also:
>
> * Please line wrap this so that the code is 80 columns wide or less,
> as is still preferred for Networking code.
>
> Flagged by checkpatch.pl --max-line-length=80
>
> * Can we move the definition of vsock_loopback_seqpacket_allow() here?
> The function itself is is trivial. And doing so would avoid a forward
> declaration.
>
> > static bool vsock_loopback_msgzerocopy_allow(void)
> > {
> > return true;
>
> ...
>
> > +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);
> > +}
>
> I think EXPORT_SYMBOL_GPL is needed for both vsock_loopback_exit_net and
> vsock_loopback_init_net for the case where CONFIG_VSOCKETS=m
>
> Also, in Kconfig VSOCKETS_LOOPBACK depends on VSOCKETS. But this code adds
> a reverse dependency. As it stands it's possible to configure VSOCKETS
> without VSOCKETS_LOOPBACK, which will not compile.
>
> Perhaps stub implementations of vsock_loopback_init_net and
> vsock_loopback_exit_net should be implemented in af_vsock.h if
> VSOCKETS_LOOPBACK is not enabled?
>
Roger that, makes sense. Thanks for the review!
Best,
Bobby
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