[RFC PATCH 1/3] vsock: add network namespace support

Stefano Garzarella
Thu, 28 Nov 2019 17:15:17 -0000

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.

G2H transports will use the default network namepsace (init_net).
H2G transports can use different network namespace for different
VMs.

This patch uses default network namepsace (init_net) in all
transports.

Signed-off-by: Stefano Garzarella <sgarzare at redhat.com>
---
 include/net/af_vsock.h                  |  6 +++--
 net/vmw_vsock/af_vsock.c                | 31 ++++++++++++++++++-------
 net/vmw_vsock/hyperv_transport.c        |  5 ++--
 net/vmw_vsock/virtio_transport_common.c |  5 ++--
 net/vmw_vsock/vmci_transport.c          |  5 ++--
 5 files changed, 35 insertions(+), 17 deletions(-)

diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h
index b1c717286993..fb7dcf73af5b 100644
--- a/include/net/af_vsock.h
+++ b/include/net/af_vsock.h
@@ -193,13 +193,15 @@ 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(void (*fn)(struct sock *sk));
 int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk);
 bool vsock_find_cid(unsigned int cid);
+struct net *vsock_default_net(void);

 /**** TAP ****/

diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index 9c5b2a91baad..b485b4a4e3e9 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -226,15 +226,18 @@ static void __vsock_remove_connected(struct vsock_sock
*vsk)
 	sock_put(&vsk->sk);
 }

-static struct sock *__vsock_find_bound_socket(struct sockaddr_vm *addr)
+static struct sock *__vsock_find_bound_socket(struct sockaddr_vm *addr,
+					      struct net *net)
 {
 	struct vsock_sock *vsk;

 	list_for_each_entry(vsk, vsock_bound_sockets(addr), bound_table) {
-		if (vsock_addr_equals_addr(addr, &vsk->local_addr))
+		if (vsock_addr_equals_addr(addr, &vsk->local_addr) &&
+		    net_eq(net, sock_net(sk_vsock(vsk))))
 			return sk_vsock(vsk);

 		if (addr->svm_port == vsk->local_addr.svm_port &&
+		    net_eq(net, sock_net(sk_vsock(vsk))) &&
 		    (vsk->local_addr.svm_cid == VMADDR_CID_ANY ||
 		     addr->svm_cid == VMADDR_CID_ANY))
 			return sk_vsock(vsk);
@@ -244,13 +247,15 @@ static struct sock *__vsock_find_bound_socket(struct
sockaddr_vm *addr)
 }

 static struct sock *__vsock_find_connected_socket(struct sockaddr_vm *src,
-						  struct sockaddr_vm *dst)
+						  struct sockaddr_vm *dst,
+						  struct net *net)
 {
 	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) &&
+		    net_eq(net, sock_net(sk_vsock(vsk))) &&
 		    dst->svm_port == vsk->local_addr.svm_port) {
 			return sk_vsock(vsk);
 		}
@@ -295,12 +300,12 @@ 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);

@@ -311,12 +316,13 @@ 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);

@@ -488,6 +494,12 @@ bool vsock_find_cid(unsigned int cid)
 }
 EXPORT_SYMBOL_GPL(vsock_find_cid);

+struct net *vsock_default_net(void)
+{
+	return &init_net;
+}
+EXPORT_SYMBOL_GPL(vsock_default_net);
+
 static struct sock *vsock_dequeue_accept(struct sock *listener)
 {
 	struct vsock_sock *vlistener;
@@ -586,6 +598,7 @@ static int __vsock_bind_stream(struct vsock_sock *vsk,
 {
 	static u32 port;
 	struct sockaddr_vm new_addr;
+	struct net *net = sock_net(sk_vsock(vsk));

 	if (!port)
 		port = LAST_RESERVED_PORT + 1 +
@@ -603,7 +616,7 @@ static int __vsock_bind_stream(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;
 			}
@@ -620,7 +633,7 @@ static int __vsock_bind_stream(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 3c7d07a99fc5..fc48a861a0bc 100644
--- a/net/vmw_vsock/hyperv_transport.c
+++ b/net/vmw_vsock/hyperv_transport.c
@@ -201,7 +201,8 @@ static void hvs_remote_addr_init(struct sockaddr_vm *remote,

 		remote->svm_port = host_ephemeral_port++;

-		sk = vsock_find_connected_socket(remote, local);
+		sk = vsock_find_connected_socket(remote, local,
+						 vsock_default_net());
 		if (!sk) {
 			/* Found an available ephemeral port */
 			return;
@@ -350,7 +351,7 @@ 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, vsock_default_net());
 	if (!sk)
 		return;

diff --git a/net/vmw_vsock/virtio_transport_common.c
b/net/vmw_vsock/virtio_transport_common.c
index 0e20b0f6eb65..10a8cbe39f61 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c
@@ -1075,6 +1075,7 @@ virtio_transport_recv_listen(struct sock *sk, struct
virtio_vsock_pkt *pkt,
 void virtio_transport_recv_pkt(struct virtio_transport *t,
 			       struct virtio_vsock_pkt *pkt)
 {
+	struct net *net = vsock_default_net();
 	struct sockaddr_vm src, dst;
 	struct vsock_sock *vsk;
 	struct sock *sk;
@@ -1102,9 +1103,9 @@ void virtio_transport_recv_pkt(struct virtio_transport *t,
 	/* The socket must be in connected or bound table
 	 * otherwise send reset back
 	 */
-	sk = vsock_find_connected_socket(&src, &dst);
+	sk = vsock_find_connected_socket(&src, &dst, net);
 	if (!sk) {
-		sk = vsock_find_bound_socket(&dst);
+		sk = vsock_find_bound_socket(&dst, net);
 		if (!sk) {
 			(void)virtio_transport_reset_no_sock(t, pkt);
 			goto free_pkt;
diff --git a/net/vmw_vsock/vmci_transport.c b/net/vmw_vsock/vmci_transport.c
index 4b8b1150a738..3ad15d51b30b 100644
--- a/net/vmw_vsock/vmci_transport.c
+++ b/net/vmw_vsock/vmci_transport.c
@@ -669,6 +669,7 @@ static bool vmci_transport_stream_allow(u32 cid, u32 port)

 static int vmci_transport_recv_stream_cb(void *data, struct vmci_datagram *dg)
 {
+	struct net *net = vsock_default_net();
 	struct sock *sk;
 	struct sockaddr_vm dst;
 	struct sockaddr_vm src;
@@ -702,9 +703,9 @@ static int vmci_transport_recv_stream_cb(void *data, struct
vmci_datagram *dg)
 	vsock_addr_init(&src, pkt->dg.src.context, pkt->src_port);
 	vsock_addr_init(&dst, pkt->dg.dst.context, pkt->dst_port);

-	sk = vsock_find_connected_socket(&src, &dst);
+	sk = vsock_find_connected_socket(&src, &dst, net);
 	if (!sk) {
-		sk = vsock_find_bound_socket(&dst);
+		sk = vsock_find_bound_socket(&dst, net);
 		if (!sk) {
 			/* We could not find a socket for this specified
 			 * address.  If this packet is a RST, we just drop it.
--
2.23.0