From: Bobby Eshleman bobbyeshleman@meta.com
Add the ability to isolate vhost-vsock flows using namespaces.
The VM, via the vhost_vsock struct, inherits its namespace from the process that opens the vhost-vsock device. vhost_vsock lookup functions are modified to take into account the mode (e.g., if CIDs are matching but modes don't align, then return NULL).
vhost_vsock now acquires a reference to the namespace.
Signed-off-by: Bobby Eshleman bobbyeshleman@meta.com --- Changes in v7: - remove the check_global flag of vhost_vsock_get(), that logic was both wrong and not necessary, reuse vsock_net_check_mode() instead - remove 'delete me' comment Changes in v5: - respect pid namespaces when assigning namespace to vhost_vsock --- drivers/vhost/vsock.c | 44 ++++++++++++++++++++++++++++++++++---------- 1 file changed, 34 insertions(+), 10 deletions(-)
diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c index 34adf0cf9124..df6136633cd8 100644 --- a/drivers/vhost/vsock.c +++ b/drivers/vhost/vsock.c @@ -46,6 +46,11 @@ static DEFINE_READ_MOSTLY_HASHTABLE(vhost_vsock_hash, 8); struct vhost_vsock { struct vhost_dev dev; struct vhost_virtqueue vqs[2]; + struct net *net; + netns_tracker ns_tracker; + + /* The ns mode at the time vhost_vsock was created */ + enum vsock_net_mode net_mode;
/* Link to global vhost_vsock_hash, writes use vhost_vsock_mutex */ struct hlist_node hash; @@ -67,7 +72,8 @@ static u32 vhost_transport_get_local_cid(void) /* Callers that dereference the return value must hold vhost_vsock_mutex or the * RCU read lock. */ -static struct vhost_vsock *vhost_vsock_get(u32 guest_cid) +static struct vhost_vsock *vhost_vsock_get(u32 guest_cid, struct net *net, + enum vsock_net_mode mode) { struct vhost_vsock *vsock;
@@ -78,9 +84,9 @@ static struct vhost_vsock *vhost_vsock_get(u32 guest_cid) if (other_cid == 0) continue;
- if (other_cid == guest_cid) + if (other_cid == guest_cid && + vsock_net_check_mode(net, mode, vsock->net, vsock->net_mode)) return vsock; - }
return NULL; @@ -271,14 +277,16 @@ static void vhost_transport_send_pkt_work(struct vhost_work *work) static int vhost_transport_send_pkt(struct sk_buff *skb) { + enum vsock_net_mode mode = virtio_vsock_skb_net_mode(skb); struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb); + struct net *net = virtio_vsock_skb_net(skb); struct vhost_vsock *vsock; int len = skb->len;
rcu_read_lock();
/* Find the vhost_vsock according to guest context id */ - vsock = vhost_vsock_get(le64_to_cpu(hdr->dst_cid)); + vsock = vhost_vsock_get(le64_to_cpu(hdr->dst_cid), net, mode); if (!vsock) { rcu_read_unlock(); kfree_skb(skb); @@ -305,7 +313,8 @@ vhost_transport_cancel_pkt(struct vsock_sock *vsk) rcu_read_lock();
/* Find the vhost_vsock according to guest context id */ - vsock = vhost_vsock_get(vsk->remote_addr.svm_cid); + vsock = vhost_vsock_get(vsk->remote_addr.svm_cid, + sock_net(sk_vsock(vsk)), vsk->net_mode); if (!vsock) goto out;
@@ -327,7 +336,7 @@ vhost_transport_cancel_pkt(struct vsock_sock *vsk) }
static struct sk_buff * -vhost_vsock_alloc_skb(struct vhost_virtqueue *vq, +vhost_vsock_alloc_skb(struct vhost_vsock *vsock, struct vhost_virtqueue *vq, unsigned int out, unsigned int in) { struct virtio_vsock_hdr *hdr; @@ -353,6 +362,9 @@ vhost_vsock_alloc_skb(struct vhost_virtqueue *vq, if (!skb) return NULL;
+ virtio_vsock_skb_set_net(skb, vsock->net); + virtio_vsock_skb_set_net_mode(skb, vsock->net_mode); + iov_iter_init(&iov_iter, ITER_SOURCE, vq->iov, out, len);
hdr = virtio_vsock_hdr(skb); @@ -462,11 +474,12 @@ static struct virtio_transport vhost_transport = {
static bool vhost_transport_seqpacket_allow(struct vsock_sock *vsk, u32 remote_cid) { + struct net *net = sock_net(sk_vsock(vsk)); struct vhost_vsock *vsock; bool seqpacket_allow = false;
rcu_read_lock(); - vsock = vhost_vsock_get(remote_cid); + vsock = vhost_vsock_get(remote_cid, net, vsk->net_mode);
if (vsock) seqpacket_allow = vsock->seqpacket_allow; @@ -520,7 +533,7 @@ static void vhost_vsock_handle_tx_kick(struct vhost_work *work) break; }
- skb = vhost_vsock_alloc_skb(vq, out, in); + skb = vhost_vsock_alloc_skb(vsock, vq, out, in); if (!skb) { vq_err(vq, "Faulted on pkt\n"); continue; @@ -652,8 +665,10 @@ static void vhost_vsock_free(struct vhost_vsock *vsock)
static int vhost_vsock_dev_open(struct inode *inode, struct file *file) { + struct vhost_virtqueue **vqs; struct vhost_vsock *vsock; + struct net *net; int ret;
/* This struct is large and allocation could fail, fall back to vmalloc @@ -669,6 +684,14 @@ static int vhost_vsock_dev_open(struct inode *inode, struct file *file) goto out; }
+ net = current->nsproxy->net_ns; + vsock->net = get_net_track(net, &vsock->ns_tracker, GFP_KERNEL); + + /* Cache the mode of the namespace so that if that netns mode changes, + * the vhost_vsock will continue to function as expected. + */ + vsock->net_mode = vsock_net_mode(net); + vsock->guest_cid = 0; /* no CID assigned yet */ vsock->seqpacket_allow = false;
@@ -708,7 +731,7 @@ static void vhost_vsock_reset_orphans(struct sock *sk) */
/* If the peer is still valid, no need to reset connection */ - if (vhost_vsock_get(vsk->remote_addr.svm_cid)) + if (vhost_vsock_get(vsk->remote_addr.svm_cid, sock_net(sk), vsk->net_mode)) return;
/* If the close timeout is pending, let it expire. This avoids races @@ -753,6 +776,7 @@ static int vhost_vsock_dev_release(struct inode *inode, struct file *file) virtio_vsock_skb_queue_purge(&vsock->send_pkt_queue);
vhost_dev_cleanup(&vsock->dev); + put_net_track(vsock->net, &vsock->ns_tracker); kfree(vsock->dev.vqs); vhost_vsock_free(vsock); return 0; @@ -779,7 +803,7 @@ static int vhost_vsock_set_cid(struct vhost_vsock *vsock, u64 guest_cid)
/* Refuse if CID is already in use */ mutex_lock(&vhost_vsock_mutex); - other = vhost_vsock_get(guest_cid); + other = vhost_vsock_get(guest_cid, vsock->net, vsock->net_mode); if (other && other != vsock) { mutex_unlock(&vhost_vsock_mutex); return -EADDRINUSE;