On Wed, Mar 19, 2025 at 02:02:32PM +0100, Stefano Garzarella wrote:
On Wed, Mar 12, 2025 at 01:59:35PM -0700, Bobby Eshleman wrote:
> From: Stefano Garzarella <sgarzare@xxxxxxxxxx>
>
> This patch adds a check of the "net" assigned to a socket during
> the vsock_find_bound_socket() and vsock_find_connected_socket()
> to support network namespace, allowing to share the same address
> (cid, port) across different network namespaces.
>
> This patch preserves old behavior, and does not yet bring up namespace
> support fully.
>
> Signed-off-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
I'd describe here a bit the new behaviour related to `fallback` that you
developed.
Or we can split this patch in two patches, one with my changes without
fallback, and another with fallback as you as author.
WDYT?
I like the idea of splitting it, that way any unforeseen issues in the
new logic can be isolated to the one patch.
> Signed-off-by: Bobby Eshleman <bobbyeshleman@xxxxxxxxx>
> ---
> v1 -> v2:
> * remove 'netns' module param
> * remove vsock_net_eq()
> * use vsock_global_net() for "global" namespace
> * use fallback logic in socket lookup functions, giving precedence to
> non-global vsock namespaces
>
> RFC -> v1
> * added 'netns' module param
> * added 'vsock_net_eq()' to check the "net" assigned to a socket
> only when 'netns' support is enabled
> ---
> include/net/af_vsock.h | 7 +++--
> net/vmw_vsock/af_vsock.c | 55 ++++++++++++++++++++++++---------
> net/vmw_vsock/hyperv_transport.c | 2 +-
> net/vmw_vsock/virtio_transport_common.c | 5 +--
> net/vmw_vsock/vmci_transport.c | 4 +--
> 5 files changed, 51 insertions(+), 22 deletions(-)
>
> diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h
> index 9e85424c834353d016a527070dd62e15ff3bfce1..41afbc18648c953da27a93571d408de968aa7668 100644
> --- a/include/net/af_vsock.h
> +++ b/include/net/af_vsock.h
> @@ -213,9 +213,10 @@ void vsock_enqueue_accept(struct sock *listener, struct sock *connected);
> void vsock_insert_connected(struct vsock_sock *vsk);
> void vsock_remove_bound(struct vsock_sock *vsk);
> void vsock_remove_connected(struct vsock_sock *vsk);
> -struct sock *vsock_find_bound_socket(struct sockaddr_vm *addr);
> +struct sock *vsock_find_bound_socket(struct sockaddr_vm *addr, struct net *net);
> struct sock *vsock_find_connected_socket(struct sockaddr_vm *src,
> - struct sockaddr_vm *dst);
> + struct sockaddr_vm *dst,
> + struct net *net);
> void vsock_remove_sock(struct vsock_sock *vsk);
> void vsock_for_each_connected_socket(struct vsock_transport *transport,
> void (*fn)(struct sock *sk));
> @@ -255,4 +256,6 @@ static inline bool vsock_msgzerocopy_allow(const struct vsock_transport *t)
> {
> return t->msgzerocopy_allow && t->msgzerocopy_allow();
> }
> +
> +struct net *vsock_global_net(void);
If it just returns null, maybe we can make it inline here.
Roger that.
> #endif /* __AF_VSOCK_H__ */
> diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
> index 7e3db87ae4333cf63327ec105ca99253569bb9fe..d206489bf0a81cf989387c7c8063be91a7c21a7d 100644
> --- a/net/vmw_vsock/af_vsock.c
> +++ b/net/vmw_vsock/af_vsock.c
> @@ -235,37 +235,60 @@ static void __vsock_remove_connected(struct vsock_sock *vsk)
> sock_put(&vsk->sk);
> }
>
> -static struct sock *__vsock_find_bound_socket(struct sockaddr_vm *addr)
> +struct net *vsock_global_net(void)
> {
> + return NULL;
> +}
> +EXPORT_SYMBOL_GPL(vsock_global_net);
> +
> +static struct sock *__vsock_find_bound_socket(struct sockaddr_vm *addr,
> + struct net *net)
> +{
Please add a comment here to describe what fallback is used for.
And I would suggest also something on top of this file to explain a bit
how netns are handled in AF_VSOCK.
sgtm!
> + struct sock *fallback = NULL;
> struct vsock_sock *vsk;
>
> list_for_each_entry(vsk, vsock_bound_sockets(addr), bound_table) {
> - if (vsock_addr_equals_addr(addr, &vsk->local_addr))
> - return sk_vsock(vsk);
> + if (vsock_addr_equals_addr(addr, &vsk->local_addr)) {
> + if (net_eq(net, sock_net(sk_vsock(vsk))))
> + return sk_vsock(vsk);
>
> + if (net_eq(net, vsock_global_net()))
> + fallback = sk_vsock(vsk);
> + }
> if (addr->svm_port == vsk->local_addr.svm_port &&
> (vsk->local_addr.svm_cid == VMADDR_CID_ANY ||
> - addr->svm_cid == VMADDR_CID_ANY))
> - return sk_vsock(vsk);
> + addr->svm_cid == VMADDR_CID_ANY)) {
> + if (net_eq(net, sock_net(sk_vsock(vsk))))
> + return sk_vsock(vsk);
> +
> + if (net_eq(net, vsock_global_net()))
> + fallback = sk_vsock(vsk);
> + }
> }
>
> - return NULL;
> + return fallback;
> }
>
> static struct sock *__vsock_find_connected_socket(struct sockaddr_vm *src,
> - struct sockaddr_vm *dst)
> + struct sockaddr_vm *dst,
> + struct net *net)
> {
> + struct sock *fallback = NULL;
> struct vsock_sock *vsk;
>
> list_for_each_entry(vsk, vsock_connected_sockets(src, dst),
> connected_table) {
> if (vsock_addr_equals_addr(src, &vsk->remote_addr) &&
> dst->svm_port == vsk->local_addr.svm_port) {
> - return sk_vsock(vsk);
> + if (net_eq(net, sock_net(sk_vsock(vsk))))
> + return sk_vsock(vsk);
> +
> + if (net_eq(net, vsock_global_net()))
> + fallback = sk_vsock(vsk);
This pattern seems to be repeated 3 times, can we make a function/macro?
yep, no problem!
> }
> }
>
> - return NULL;
> + return fallback;
> }
>
> static void vsock_insert_unbound(struct vsock_sock *vsk)
> @@ -304,12 +327,12 @@ void vsock_remove_connected(struct vsock_sock *vsk)
> }
> EXPORT_SYMBOL_GPL(vsock_remove_connected);
>
> -struct sock *vsock_find_bound_socket(struct sockaddr_vm *addr)
> +struct sock *vsock_find_bound_socket(struct sockaddr_vm *addr, struct net *net)
> {
> struct sock *sk;
>
> spin_lock_bh(&vsock_table_lock);
> - sk = __vsock_find_bound_socket(addr);
> + sk = __vsock_find_bound_socket(addr, net);
> if (sk)
> sock_hold(sk);
>
> @@ -320,12 +343,13 @@ struct sock *vsock_find_bound_socket(struct sockaddr_vm *addr)
> EXPORT_SYMBOL_GPL(vsock_find_bound_socket);
>
> struct sock *vsock_find_connected_socket(struct sockaddr_vm *src,
> - struct sockaddr_vm *dst)
> + struct sockaddr_vm *dst,
> + struct net *net)
> {
> struct sock *sk;
>
> spin_lock_bh(&vsock_table_lock);
> - sk = __vsock_find_connected_socket(src, dst);
> + sk = __vsock_find_connected_socket(src, dst, net);
> if (sk)
> sock_hold(sk);
>
> @@ -644,6 +668,7 @@ static int __vsock_bind_connectible(struct vsock_sock *vsk,
> {
> static u32 port;
> struct sockaddr_vm new_addr;
> + struct net *net = sock_net(sk_vsock(vsk));
>
> if (!port)
> port = get_random_u32_above(LAST_RESERVED_PORT);
> @@ -660,7 +685,7 @@ static int __vsock_bind_connectible(struct vsock_sock *vsk,
>
> new_addr.svm_port = port++;
>
> - if (!__vsock_find_bound_socket(&new_addr)) {
> + if (!__vsock_find_bound_socket(&new_addr, net)) {
> found = true;
> break;
> }
> @@ -677,7 +702,7 @@ static int __vsock_bind_connectible(struct vsock_sock *vsk,
> return -EACCES;
> }
>
> - if (__vsock_find_bound_socket(&new_addr))
> + if (__vsock_find_bound_socket(&new_addr, net))
> return -EADDRINUSE;
> }
>
> diff --git a/net/vmw_vsock/hyperv_transport.c b/net/vmw_vsock/hyperv_transport.c
> index 31342ab502b4fc35feb812d2c94e0e35ded73771..253609898d24f8a484fcfc3296011c6f501a72a8 100644
> --- a/net/vmw_vsock/hyperv_transport.c
> +++ b/net/vmw_vsock/hyperv_transport.c
> @@ -313,7 +313,7 @@ static void hvs_open_connection(struct vmbus_channel *chan)
> return;
>
> hvs_addr_init(&addr, conn_from_host ? if_type : if_instance);
> - sk = vsock_find_bound_socket(&addr);
> + sk = vsock_find_bound_socket(&addr, NULL);
> if (!sk)
> return;
>
> diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
> index 7f7de6d8809655fe522749fbbc9025df71f071bd..256d2a4fe482b3cb938a681b6924be69b2065616 100644
> --- a/net/vmw_vsock/virtio_transport_common.c
> +++ b/net/vmw_vsock/virtio_transport_common.c
> @@ -1590,6 +1590,7 @@ void virtio_transport_recv_pkt(struct virtio_transport *t,
> struct sk_buff *skb)
> {
> struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
> + struct net *net = vsock_global_net();
Why using vsock_global_net() in virtio and directly NULL in the others
transports?
This was an oversight on my part, I found an unnamed NULL harder to
reason about, switched to the func, but forgot to switch over the other
transports.
BTW, I was unsure about just making NULL a macro (e.g.,
VIRTIO_VSOCK_GLOBAL_NET?) instead of a function. I just used a function
because A) I noticed in the prior rev that the default net was a
function instead of some macro to &init_net, and B) the function seemed
a little more flexible for future changes. What are your thoughts here?
