From: Bobby Eshleman <[email protected]>

Add netns logic to vsock core. Additionally, modify transport hook
prototypes to be used by later transport-specific patches (e.g.,
*_seqpacket_allow()).

Namespaces are supported primarily by changing socket lookup functions
(e.g., vsock_find_connected_socket()) to take into account the socket
namespace and the namespace mode before considering a candidate socket a
"match".

This patch also introduces the sysctl /proc/sys/net/vsock/ns_mode to
report the mode and /proc/sys/net/vsock/child_ns_mode to set the mode
for new namespaces.

Add netns functionality (initialization, passing to transports, procfs,
etc...) to the af_vsock socket layer. Later patches that add netns
support to transports depend on this patch.

dgram_allow(), stream_allow(), and seqpacket_allow() callbacks are
modified to take a vsk in order to perform logic on namespace modes. In
future patches, the net will also be used for socket
lookups in these functions.

Signed-off-by: Bobby Eshleman <[email protected]>
---
Changes in v13:
- remove net_mode and replace with direct accesses to net->vsock.mode,
  since this is now immutable.
- update comments about mode behavior and mutability, and sysctl API
- only pass NULL for net when wanting global, instead of net_mode ==
  VSOCK_NET_MODE_GLOBAL. This reflects the new logic
  of vsock_net_check_mode() that only requires net pointers (not
  net_mode).
- refactor sysctl string code into a re-usable function, because
  child_ns_mode and ns_mode both handle the same strings.
- remove redundant vsock_net_init(&init_net) call in module init because
  pernet registration calls the callback on the init_net too

Changes in v12:
- return true in dgram_allow(), stream_allow(), and seqpacket_allow()
  only if net_mode == VSOCK_NET_MODE_GLOBAL (Stefano)
- document bind(VMADDR_CID_ANY) case in af_vsock.c (Stefano)
- change order of stream_allow() call in vmci so we can pass vsk
  to it

Changes in v10:
- add file-level comment about what happens to sockets/devices
  when the namespace mode changes (Stefano)
- change the 'if (write)' boolean in vsock_net_mode_string() to
  if (!write), this simplifies a later patch which adds "goto"
  for mutex unlocking on function exit.

Changes in v9:
- remove virtio_vsock_alloc_rx_skb() (Stefano)
- remove vsock_global_dummy_net, not needed as net=NULL +
  net_mode=VSOCK_NET_MODE_GLOBAL achieves identical result

Changes in v7:
- hv_sock: fix hyperv build error
- explain why vhost does not use the dummy
- explain usage of __vsock_global_dummy_net
- explain why VSOCK_NET_MODE_STR_MAX is 8 characters
- use switch-case in vsock_net_mode_string()
- avoid changing transports as much as possible
- add vsock_find_{bound,connected}_socket_net()
- rename `vsock_hdr` to `sysctl_hdr`
- add virtio_vsock_alloc_linear_skb() wrapper for setting dummy net and
  global mode for virtio-vsock, move skb->cb zero-ing into wrapper
- explain seqpacket_allow() change
- move net setting to __vsock_create() instead of vsock_create() so
  that child sockets also have their net assigned upon accept()

Changes in v6:
- unregister sysctl ops in vsock_exit()
- af_vsock: clarify description of CID behavior
- af_vsock: fix buf vs buffer naming, and length checking
- af_vsock: fix length checking w/ correct ctl_table->maxlen

Changes in v5:
- vsock_global_net() -> vsock_global_dummy_net()
- update comments for new uAPI
- use /proc/sys/net/vsock/ns_mode instead of /proc/net/vsock_ns_mode
- add prototype changes so patch remains compilable
---
 drivers/vhost/vsock.c                   |   9 +-
 include/linux/virtio_vsock.h            |   4 +-
 include/net/af_vsock.h                  |  11 +-
 net/vmw_vsock/af_vsock.c                | 296 +++++++++++++++++++++++++++++---
 net/vmw_vsock/hyperv_transport.c        |   7 +-
 net/vmw_vsock/virtio_transport.c        |   9 +-
 net/vmw_vsock/virtio_transport_common.c |   6 +-
 net/vmw_vsock/vmci_transport.c          |  26 ++-
 net/vmw_vsock/vsock_loopback.c          |   8 +-
 9 files changed, 332 insertions(+), 44 deletions(-)

diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
index 0298ddc34824..8eca59fd1afb 100644
--- a/drivers/vhost/vsock.c
+++ b/drivers/vhost/vsock.c
@@ -406,7 +406,8 @@ static bool vhost_transport_msgzerocopy_allow(void)
        return true;
 }
 
-static bool vhost_transport_seqpacket_allow(u32 remote_cid);
+static bool vhost_transport_seqpacket_allow(struct vsock_sock *vsk,
+                                           u32 remote_cid);
 
 static struct virtio_transport vhost_transport = {
        .transport = {
@@ -462,11 +463,15 @@ static struct virtio_transport vhost_transport = {
        .send_pkt = vhost_transport_send_pkt,
 };
 
-static bool vhost_transport_seqpacket_allow(u32 remote_cid)
+static bool vhost_transport_seqpacket_allow(struct vsock_sock *vsk,
+                                           u32 remote_cid)
 {
        struct vhost_vsock *vsock;
        bool seqpacket_allow = false;
 
+       if (vsock_net_mode(sock_net(sk_vsock(vsk))) != VSOCK_NET_MODE_GLOBAL)
+               return false;
+
        rcu_read_lock();
        vsock = vhost_vsock_get(remote_cid);
 
diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h
index 0c67543a45c8..1845e8d4f78d 100644
--- a/include/linux/virtio_vsock.h
+++ b/include/linux/virtio_vsock.h
@@ -256,10 +256,10 @@ void virtio_transport_notify_buffer_size(struct 
vsock_sock *vsk, u64 *val);
 
 u64 virtio_transport_stream_rcvhiwat(struct vsock_sock *vsk);
 bool virtio_transport_stream_is_active(struct vsock_sock *vsk);
-bool virtio_transport_stream_allow(u32 cid, u32 port);
+bool virtio_transport_stream_allow(struct vsock_sock *vsk, u32 cid, u32 port);
 int virtio_transport_dgram_bind(struct vsock_sock *vsk,
                                struct sockaddr_vm *addr);
-bool virtio_transport_dgram_allow(u32 cid, u32 port);
+bool virtio_transport_dgram_allow(struct vsock_sock *vsk, u32 cid, u32 port);
 
 int virtio_transport_connect(struct vsock_sock *vsk);
 
diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h
index 6f5bc9dbefa5..10c2846fcc58 100644
--- a/include/net/af_vsock.h
+++ b/include/net/af_vsock.h
@@ -125,7 +125,7 @@ struct vsock_transport {
                             size_t len, int flags);
        int (*dgram_enqueue)(struct vsock_sock *, struct sockaddr_vm *,
                             struct msghdr *, size_t len);
-       bool (*dgram_allow)(u32 cid, u32 port);
+       bool (*dgram_allow)(struct vsock_sock *vsk, u32 cid, u32 port);
 
        /* STREAM. */
        /* TODO: stream_bind() */
@@ -137,14 +137,14 @@ struct vsock_transport {
        s64 (*stream_has_space)(struct vsock_sock *);
        u64 (*stream_rcvhiwat)(struct vsock_sock *);
        bool (*stream_is_active)(struct vsock_sock *);
-       bool (*stream_allow)(u32 cid, u32 port);
+       bool (*stream_allow)(struct vsock_sock *vsk, u32 cid, u32 port);
 
        /* SEQ_PACKET. */
        ssize_t (*seqpacket_dequeue)(struct vsock_sock *vsk, struct msghdr *msg,
                                     int flags);
        int (*seqpacket_enqueue)(struct vsock_sock *vsk, struct msghdr *msg,
                                 size_t len);
-       bool (*seqpacket_allow)(u32 remote_cid);
+       bool (*seqpacket_allow)(struct vsock_sock *vsk, u32 remote_cid);
        u32 (*seqpacket_has_data)(struct vsock_sock *vsk);
 
        /* Notification. */
@@ -217,6 +217,11 @@ void vsock_remove_connected(struct vsock_sock *vsk);
 struct sock *vsock_find_bound_socket(struct sockaddr_vm *addr);
 struct sock *vsock_find_connected_socket(struct sockaddr_vm *src,
                                         struct sockaddr_vm *dst);
+struct sock *vsock_find_bound_socket_net(struct sockaddr_vm *addr,
+                                        struct net *net);
+struct sock *vsock_find_connected_socket_net(struct sockaddr_vm *src,
+                                            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));
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index adcba1b7bf74..0eb2364e09aa 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -83,6 +83,42 @@
  *   TCP_ESTABLISHED - connected
  *   TCP_CLOSING - disconnecting
  *   TCP_LISTEN - listening
+ *
+ * - Namespaces in vsock support two different modes configured
+ *   through /proc/sys/net/vsock/ns_mode. The modes are "local" and "global".
+ *   Each mode defines how the namespace interacts with CIDs.
+ *   /proc/sys/net/vsock/ns_mode is read-only and inherited from the
+ *   parent namespace's /proc/sys/net/vsock/child_ns_mode at creation
+ *   time and is immutable thereafter. The default is "global".
+ *
+ *   The modes affect the allocation and accessibility of CIDs as follows:
+ *
+ *   - global - access and allocation are all system-wide
+ *      - all CID allocation from global namespaces draw from the same
+ *        system-wide pool.
+ *      - if one global namespace has already allocated some CID, another
+ *        global namespace will not be able to allocate the same CID.
+ *      - global mode AF_VSOCK sockets can reach any VM or socket in any global
+ *        namespace, they are not contained to only their own namespace.
+ *      - AF_VSOCK sockets in a global mode namespace cannot reach VMs or
+ *        sockets in any local mode namespace.
+ *   - local - access and allocation are contained within the namespace
+ *     - CID allocation draws only from a private pool local only to the
+ *       namespace, and does not affect the CIDs available for allocation in 
any
+ *       other namespace (global or local).
+ *     - VMs in a local namespace do not collide with CIDs in any other local
+ *       namespace or any global namespace. For example, if a VM in a local 
mode
+ *       namespace is given CID 10, then CID 10 is still available for
+ *       allocation in any other namespace, but not in the same namespace.
+ *     - AF_VSOCK sockets in a local mode namespace can connect only to VMs or
+ *       other sockets within their own namespace.
+ *     - sockets bound to VMADDR_CID_ANY in local namespaces will never resolve
+ *       to any transport that is not compatible with local mode. There is no
+ *       error that propagates to the user (as there is for connection 
attempts)
+ *       because it is possible for some packet to reach this socket from
+ *       a different transport that *does* support local mode. For
+ *       example, virtio-vsock may not support local mode, but the socket
+ *       may still accept a connection from vhost-vsock which does.
  */
 
 #include <linux/compat.h>
@@ -100,6 +136,7 @@
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/net.h>
+#include <linux/proc_fs.h>
 #include <linux/poll.h>
 #include <linux/random.h>
 #include <linux/skbuff.h>
@@ -111,9 +148,18 @@
 #include <linux/workqueue.h>
 #include <net/sock.h>
 #include <net/af_vsock.h>
+#include <net/netns/vsock.h>
 #include <uapi/linux/vm_sockets.h>
 #include <uapi/asm-generic/ioctls.h>
 
+#define VSOCK_NET_MODE_STR_GLOBAL "global"
+#define VSOCK_NET_MODE_STR_LOCAL "local"
+
+/* 6 chars for "global", 1 for null-terminator, and 1 more for '\n'.
+ * The newline is added by proc_dostring() for read operations.
+ */
+#define VSOCK_NET_MODE_STR_MAX 8
+
 static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr);
 static void vsock_sk_destruct(struct sock *sk);
 static int vsock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
@@ -235,33 +281,42 @@ 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_net(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))
-                       return sk_vsock(vsk);
+               struct sock *sk = sk_vsock(vsk);
+
+               if (vsock_addr_equals_addr(addr, &vsk->local_addr) &&
+                   vsock_net_check_mode(sock_net(sk), net))
+                       return sk;
 
                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) &&
+                    vsock_net_check_mode(sock_net(sk), net))
+                       return sk;
        }
 
        return NULL;
 }
 
-static struct sock *__vsock_find_connected_socket(struct sockaddr_vm *src,
-                                                 struct sockaddr_vm *dst)
+static struct sock *
+__vsock_find_connected_socket_net(struct sockaddr_vm *src,
+                                 struct sockaddr_vm *dst, struct net *net)
 {
        struct vsock_sock *vsk;
 
        list_for_each_entry(vsk, vsock_connected_sockets(src, dst),
                            connected_table) {
+               struct sock *sk = sk_vsock(vsk);
+
                if (vsock_addr_equals_addr(src, &vsk->remote_addr) &&
-                   dst->svm_port == vsk->local_addr.svm_port) {
-                       return sk_vsock(vsk);
+                   dst->svm_port == vsk->local_addr.svm_port &&
+                   vsock_net_check_mode(sock_net(sk), net)) {
+                       return sk;
                }
        }
 
@@ -304,12 +359,13 @@ 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_net(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_net(addr, net);
        if (sk)
                sock_hold(sk);
 
@@ -317,15 +373,22 @@ struct sock *vsock_find_bound_socket(struct sockaddr_vm 
*addr)
 
        return sk;
 }
+EXPORT_SYMBOL_GPL(vsock_find_bound_socket_net);
+
+struct sock *vsock_find_bound_socket(struct sockaddr_vm *addr)
+{
+       return vsock_find_bound_socket_net(addr, NULL);
+}
 EXPORT_SYMBOL_GPL(vsock_find_bound_socket);
 
-struct sock *vsock_find_connected_socket(struct sockaddr_vm *src,
-                                        struct sockaddr_vm *dst)
+struct sock *vsock_find_connected_socket_net(struct sockaddr_vm *src,
+                                            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_net(src, dst, net);
        if (sk)
                sock_hold(sk);
 
@@ -333,6 +396,13 @@ struct sock *vsock_find_connected_socket(struct 
sockaddr_vm *src,
 
        return sk;
 }
+EXPORT_SYMBOL_GPL(vsock_find_connected_socket_net);
+
+struct sock *vsock_find_connected_socket(struct sockaddr_vm *src,
+                                        struct sockaddr_vm *dst)
+{
+       return vsock_find_connected_socket_net(src, dst, NULL);
+}
 EXPORT_SYMBOL_GPL(vsock_find_connected_socket);
 
 void vsock_remove_sock(struct vsock_sock *vsk)
@@ -528,7 +598,7 @@ int vsock_assign_transport(struct vsock_sock *vsk, struct 
vsock_sock *psk)
 
        if (sk->sk_type == SOCK_SEQPACKET) {
                if (!new_transport->seqpacket_allow ||
-                   !new_transport->seqpacket_allow(remote_cid)) {
+                   !new_transport->seqpacket_allow(vsk, remote_cid)) {
                        module_put(new_transport->module);
                        return -ESOCKTNOSUPPORT;
                }
@@ -676,6 +746,7 @@ static void vsock_pending_work(struct work_struct *work)
 static int __vsock_bind_connectible(struct vsock_sock *vsk,
                                    struct sockaddr_vm *addr)
 {
+       struct net *net = sock_net(sk_vsock(vsk));
        static u32 port;
        struct sockaddr_vm new_addr;
 
@@ -695,7 +766,7 @@ 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_net(&new_addr, net)) {
                                found = true;
                                break;
                        }
@@ -712,7 +783,7 @@ static int __vsock_bind_connectible(struct vsock_sock *vsk,
                        return -EACCES;
                }
 
-               if (__vsock_find_bound_socket(&new_addr))
+               if (__vsock_find_bound_socket_net(&new_addr, net))
                        return -EADDRINUSE;
        }
 
@@ -1314,7 +1385,7 @@ static int vsock_dgram_sendmsg(struct socket *sock, 
struct msghdr *msg,
                goto out;
        }
 
-       if (!transport->dgram_allow(remote_addr->svm_cid,
+       if (!transport->dgram_allow(vsk, remote_addr->svm_cid,
                                    remote_addr->svm_port)) {
                err = -EINVAL;
                goto out;
@@ -1355,7 +1426,7 @@ static int vsock_dgram_connect(struct socket *sock,
        if (err)
                goto out;
 
-       if (!vsk->transport->dgram_allow(remote_addr->svm_cid,
+       if (!vsk->transport->dgram_allow(vsk, remote_addr->svm_cid,
                                         remote_addr->svm_port)) {
                err = -EINVAL;
                goto out;
@@ -1585,7 +1656,7 @@ static int vsock_connect(struct socket *sock, struct 
sockaddr_unsized *addr,
                 * endpoints.
                 */
                if (!transport ||
-                   !transport->stream_allow(remote_addr->svm_cid,
+                   !transport->stream_allow(vsk, remote_addr->svm_cid,
                                             remote_addr->svm_port)) {
                        err = -ENETUNREACH;
                        goto out;
@@ -2658,6 +2729,183 @@ static struct miscdevice vsock_device = {
        .fops           = &vsock_device_ops,
 };
 
+static int __vsock_net_mode_string(const struct ctl_table *table, int write,
+                                  void *buffer, size_t *lenp, loff_t *ppos,
+                                  enum vsock_net_mode mode,
+                                  enum vsock_net_mode *new_mode)
+{
+       char data[VSOCK_NET_MODE_STR_MAX] = {0};
+       struct ctl_table tmp;
+       int ret;
+
+       if (!table->data || !table->maxlen || !*lenp) {
+               *lenp = 0;
+               return 0;
+       }
+
+       tmp = *table;
+       tmp.data = data;
+
+       if (!write) {
+               const char *p;
+
+               switch (mode) {
+               case VSOCK_NET_MODE_GLOBAL:
+                       p = VSOCK_NET_MODE_STR_GLOBAL;
+                       break;
+               case VSOCK_NET_MODE_LOCAL:
+                       p = VSOCK_NET_MODE_STR_LOCAL;
+                       break;
+               default:
+                       WARN_ONCE(true, "netns has invalid vsock mode");
+                       *lenp = 0;
+                       return 0;
+               }
+
+               strscpy(data, p, sizeof(data));
+               tmp.maxlen = strlen(p);
+       }
+
+       ret = proc_dostring(&tmp, write, buffer, lenp, ppos);
+       if (ret)
+               return ret;
+
+       if (!write)
+               return 0;
+
+       if (*lenp >= sizeof(data))
+               return -EINVAL;
+
+       if (!strncmp(data, VSOCK_NET_MODE_STR_GLOBAL, sizeof(data)))
+               *new_mode = VSOCK_NET_MODE_GLOBAL;
+       else if (!strncmp(data, VSOCK_NET_MODE_STR_LOCAL, sizeof(data)))
+               *new_mode = VSOCK_NET_MODE_LOCAL;
+       else
+               return -EINVAL;
+
+       return 0;
+}
+
+static int vsock_net_mode_string(const struct ctl_table *table, int write,
+                                void *buffer, size_t *lenp, loff_t *ppos)
+{
+       struct net *net;
+
+       if (write)
+               return -EPERM;
+
+       net = current->nsproxy->net_ns;
+
+       return __vsock_net_mode_string(table, write, buffer, lenp, ppos,
+                                      vsock_net_mode(net), NULL);
+}
+
+static int vsock_net_child_mode_string(const struct ctl_table *table, int 
write,
+                                      void *buffer, size_t *lenp, loff_t *ppos)
+{
+       enum vsock_net_mode new_mode;
+       struct net *net;
+       int ret;
+
+       net = current->nsproxy->net_ns;
+
+       ret = __vsock_net_mode_string(table, write, buffer, lenp, ppos,
+                                     vsock_net_child_mode(net), &new_mode);
+       if (ret)
+               return ret;
+
+       if (write)
+               vsock_net_set_child_mode(net, new_mode);
+
+       return 0;
+}
+
+static struct ctl_table vsock_table[] = {
+       {
+               .procname       = "ns_mode",
+               .data           = &init_net.vsock.mode,
+               .maxlen         = VSOCK_NET_MODE_STR_MAX,
+               .mode           = 0444,
+               .proc_handler   = vsock_net_mode_string
+       },
+       {
+               .procname       = "child_ns_mode",
+               .data           = &init_net.vsock.child_ns_mode,
+               .maxlen         = VSOCK_NET_MODE_STR_MAX,
+               .mode           = 0644,
+               .proc_handler   = vsock_net_child_mode_string
+       },
+};
+
+static int __net_init vsock_sysctl_register(struct net *net)
+{
+       struct ctl_table *table;
+
+       if (net_eq(net, &init_net)) {
+               table = vsock_table;
+       } else {
+               table = kmemdup(vsock_table, sizeof(vsock_table), GFP_KERNEL);
+               if (!table)
+                       goto err_alloc;
+
+               table[0].data = &net->vsock.mode;
+               table[1].data = &net->vsock.child_ns_mode;
+       }
+
+       net->vsock.sysctl_hdr = register_net_sysctl_sz(net, "net/vsock", table,
+                                                      ARRAY_SIZE(vsock_table));
+       if (!net->vsock.sysctl_hdr)
+               goto err_reg;
+
+       return 0;
+
+err_reg:
+       if (!net_eq(net, &init_net))
+               kfree(table);
+err_alloc:
+       return -ENOMEM;
+}
+
+static void vsock_sysctl_unregister(struct net *net)
+{
+       const struct ctl_table *table;
+
+       table = net->vsock.sysctl_hdr->ctl_table_arg;
+       unregister_net_sysctl_table(net->vsock.sysctl_hdr);
+       if (!net_eq(net, &init_net))
+               kfree(table);
+}
+
+static void vsock_net_init(struct net *net)
+{
+       if (net_eq(net, &init_net))
+               net->vsock.mode = VSOCK_NET_MODE_GLOBAL;
+       else
+               net->vsock.mode = 
vsock_net_child_mode(current->nsproxy->net_ns);
+
+       net->vsock.child_ns_mode = VSOCK_NET_MODE_GLOBAL;
+}
+
+static __net_init int vsock_sysctl_init_net(struct net *net)
+{
+       vsock_net_init(net);
+
+       if (vsock_sysctl_register(net))
+               return -ENOMEM;
+
+       return 0;
+}
+
+static __net_exit void vsock_sysctl_exit_net(struct net *net)
+{
+       vsock_sysctl_unregister(net);
+}
+
+static struct pernet_operations vsock_sysctl_ops __net_initdata = {
+       .init = vsock_sysctl_init_net,
+       .exit = vsock_sysctl_exit_net,
+};
+
 static int __init vsock_init(void)
 {
        int err = 0;
@@ -2685,10 +2933,17 @@ static int __init vsock_init(void)
                goto err_unregister_proto;
        }
 
+       if (register_pernet_subsys(&vsock_sysctl_ops)) {
+               err = -ENOMEM;
+               goto err_unregister_sock;
+       }
+
        vsock_bpf_build_proto();
 
        return 0;
 
+err_unregister_sock:
+       sock_unregister(AF_VSOCK);
 err_unregister_proto:
        proto_unregister(&vsock_proto);
 err_deregister_misc:
@@ -2702,6 +2957,7 @@ static void __exit vsock_exit(void)
        misc_deregister(&vsock_device);
        sock_unregister(AF_VSOCK);
        proto_unregister(&vsock_proto);
+       unregister_pernet_subsys(&vsock_sysctl_ops);
 }
 
 const struct vsock_transport *vsock_core_get_transport(struct vsock_sock *vsk)
diff --git a/net/vmw_vsock/hyperv_transport.c b/net/vmw_vsock/hyperv_transport.c
index 432fcbbd14d4..4d6d7807f152 100644
--- a/net/vmw_vsock/hyperv_transport.c
+++ b/net/vmw_vsock/hyperv_transport.c
@@ -570,7 +570,7 @@ static int hvs_dgram_enqueue(struct vsock_sock *vsk,
        return -EOPNOTSUPP;
 }
 
-static bool hvs_dgram_allow(u32 cid, u32 port)
+static bool hvs_dgram_allow(struct vsock_sock *vsk, u32 cid, u32 port)
 {
        return false;
 }
@@ -745,8 +745,11 @@ static bool hvs_stream_is_active(struct vsock_sock *vsk)
        return hvs->chan != NULL;
 }
 
-static bool hvs_stream_allow(u32 cid, u32 port)
+static bool hvs_stream_allow(struct vsock_sock *vsk, u32 cid, u32 port)
 {
+       if (vsock_net_mode(sock_net(sk_vsock(vsk))) != VSOCK_NET_MODE_GLOBAL)
+               return false;
+
        if (cid == VMADDR_CID_HOST)
                return true;
 
diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
index 8c867023a2e5..37eeefddb48c 100644
--- a/net/vmw_vsock/virtio_transport.c
+++ b/net/vmw_vsock/virtio_transport.c
@@ -536,7 +536,8 @@ static bool virtio_transport_msgzerocopy_allow(void)
        return true;
 }
 
-static bool virtio_transport_seqpacket_allow(u32 remote_cid);
+static bool virtio_transport_seqpacket_allow(struct vsock_sock *vsk,
+                                            u32 remote_cid);
 
 static struct virtio_transport virtio_transport = {
        .transport = {
@@ -593,11 +594,15 @@ static struct virtio_transport virtio_transport = {
        .can_msgzerocopy = virtio_transport_can_msgzerocopy,
 };
 
-static bool virtio_transport_seqpacket_allow(u32 remote_cid)
+static bool
+virtio_transport_seqpacket_allow(struct vsock_sock *vsk, u32 remote_cid)
 {
        struct virtio_vsock *vsock;
        bool seqpacket_allow;
 
+       if (vsock_net_mode(sock_net(sk_vsock(vsk))) != VSOCK_NET_MODE_GLOBAL)
+               return false;
+
        seqpacket_allow = false;
        rcu_read_lock();
        vsock = rcu_dereference(the_virtio_vsock);
diff --git a/net/vmw_vsock/virtio_transport_common.c 
b/net/vmw_vsock/virtio_transport_common.c
index dcc8a1d5851e..fdb8f5b3fa60 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c
@@ -1043,9 +1043,9 @@ bool virtio_transport_stream_is_active(struct vsock_sock 
*vsk)
 }
 EXPORT_SYMBOL_GPL(virtio_transport_stream_is_active);
 
-bool virtio_transport_stream_allow(u32 cid, u32 port)
+bool virtio_transport_stream_allow(struct vsock_sock *vsk, u32 cid, u32 port)
 {
-       return true;
+       return vsock_net_mode(sock_net(sk_vsock(vsk))) == VSOCK_NET_MODE_GLOBAL;
 }
 EXPORT_SYMBOL_GPL(virtio_transport_stream_allow);
 
@@ -1056,7 +1056,7 @@ int virtio_transport_dgram_bind(struct vsock_sock *vsk,
 }
 EXPORT_SYMBOL_GPL(virtio_transport_dgram_bind);
 
-bool virtio_transport_dgram_allow(u32 cid, u32 port)
+bool virtio_transport_dgram_allow(struct vsock_sock *vsk, u32 cid, u32 port)
 {
        return false;
 }
diff --git a/net/vmw_vsock/vmci_transport.c b/net/vmw_vsock/vmci_transport.c
index 7eccd6708d66..d5ce39ea5a1b 100644
--- a/net/vmw_vsock/vmci_transport.c
+++ b/net/vmw_vsock/vmci_transport.c
@@ -646,13 +646,17 @@ static int vmci_transport_recv_dgram_cb(void *data, 
struct vmci_datagram *dg)
        return VMCI_SUCCESS;
 }
 
-static bool vmci_transport_stream_allow(u32 cid, u32 port)
+static bool vmci_transport_stream_allow(struct vsock_sock *vsk, u32 cid,
+                                       u32 port)
 {
        static const u32 non_socket_contexts[] = {
                VMADDR_CID_LOCAL,
        };
        int i;
 
+       if (vsock_net_mode(sock_net(sk_vsock(vsk))) != VSOCK_NET_MODE_GLOBAL)
+               return false;
+
        BUILD_BUG_ON(sizeof(cid) != sizeof(*non_socket_contexts));
 
        for (i = 0; i < ARRAY_SIZE(non_socket_contexts); i++) {
@@ -682,12 +686,10 @@ static int vmci_transport_recv_stream_cb(void *data, 
struct vmci_datagram *dg)
        err = VMCI_SUCCESS;
        bh_process_pkt = false;
 
-       /* Ignore incoming packets from contexts without sockets, or resources
-        * that aren't vsock implementations.
+       /* Ignore incoming packets from resources that aren't vsock
+        * implementations.
         */
-
-       if (!vmci_transport_stream_allow(dg->src.context, -1)
-           || vmci_transport_peer_rid(dg->src.context) != dg->src.resource)
+       if (vmci_transport_peer_rid(dg->src.context) != dg->src.resource)
                return VMCI_ERROR_NO_ACCESS;
 
        if (VMCI_DG_SIZE(dg) < sizeof(*pkt))
@@ -749,6 +751,12 @@ static int vmci_transport_recv_stream_cb(void *data, 
struct vmci_datagram *dg)
                goto out;
        }
 
+       /* Ignore incoming packets from contexts without sockets. */
+       if (!vmci_transport_stream_allow(vsk, dg->src.context, -1)) {
+               err = VMCI_ERROR_NO_ACCESS;
+               goto out;
+       }
+
        /* We do most everything in a work queue, but let's fast path the
         * notification of reads and writes to help data transfer performance.
         * We can only do this if there is no process context code executing
@@ -1784,8 +1792,12 @@ static int vmci_transport_dgram_dequeue(struct 
vsock_sock *vsk,
        return err;
 }
 
-static bool vmci_transport_dgram_allow(u32 cid, u32 port)
+static bool vmci_transport_dgram_allow(struct vsock_sock *vsk, u32 cid,
+                                      u32 port)
 {
+       if (vsock_net_mode(sock_net(sk_vsock(vsk))) != VSOCK_NET_MODE_GLOBAL)
+               return false;
+
        if (cid == VMADDR_CID_HYPERVISOR) {
                /* Registrations of PBRPC Servers do not modify VMX/Hypervisor
                 * state and are allowed.
diff --git a/net/vmw_vsock/vsock_loopback.c b/net/vmw_vsock/vsock_loopback.c
index bc2ff918b315..378a96dcb666 100644
--- a/net/vmw_vsock/vsock_loopback.c
+++ b/net/vmw_vsock/vsock_loopback.c
@@ -46,7 +46,8 @@ 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;
@@ -106,9 +107,10 @@ 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;
+       return vsock_net_mode(sock_net(sk_vsock(vsk))) == VSOCK_NET_MODE_GLOBAL;
 }
 
 static void vsock_loopback_work(struct work_struct *work)

-- 
2.47.3


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