From: Bobby Eshleman bobbyeshleman@meta.com

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 that accepts the "global" or "local" mode strings.

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 and net_mode will also be used for socket lookups in these functions.

Signed-off-by: Bobby Eshleman bobbyeshleman@meta.com --- 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 | 13 +- net/vmw_vsock/af_vsock.c | 272 +++++++++++++++++++++++++++++--- 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, 310 insertions(+), 44 deletions(-)

diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c index ae01457ea2cd..83937e1d63fa 100644 --- a/drivers/vhost/vsock.c +++ b/drivers/vhost/vsock.c @@ -404,7 +404,8 @@ 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 = { @@ -460,11 +461,15 @@ 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 (vsk->net_mode != 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 9b5bdd083b6f..d10e73cd7413 100644 --- a/include/net/af_vsock.h +++ b/include/net/af_vsock.h @@ -126,7 +126,7 @@ 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() */ @@ -138,14 +138,14 @@ 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. */ @@ -218,6 +218,13 @@ 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, + enum vsock_net_mode net_mode); +struct sock *vsock_find_connected_socket_net(struct sockaddr_vm *src, + struct sockaddr_vm *dst, + struct net *net, + enum vsock_net_mode net_mode); 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..6113c22db8dc 100644 --- a/net/vmw_vsock/af_vsock.c +++ b/net/vmw_vsock/af_vsock.c @@ -83,6 +83,46 @@ * 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 write-once, so that it may be configured + * and locked down by a namespace manager. The default is "global". The mode + * is set per-namespace. + * + * 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. + * + * - when a socket or device is initialized in a namespace with mode + * global, it will stay in global mode even if the namespace later + * changes to local. */

#include <linux/compat.h> @@ -100,6 +140,7 @@ #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 +152,18 @@ #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 +285,47 @@ 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, + enum vsock_net_mode net_mode) { 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), vsk->net_mode, net, + net_mode)) + 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), vsk->net_mode, net, + net_mode)) + 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, + enum vsock_net_mode net_mode) { 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), vsk->net_mode, net, + net_mode)) { + return sk; } }

@@ -304,12 +368,14 @@ 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, + enum vsock_net_mode net_mode) { struct sock *sk;

spin_lock_bh(&vsock_table_lock); - sk = __vsock_find_bound_socket(addr); + sk = __vsock_find_bound_socket_net(addr, net, net_mode); if (sk) sock_hold(sk);

@@ -317,15 +383,23 @@ 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, VSOCK_NET_MODE_GLOBAL); +} 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, + enum vsock_net_mode net_mode) { 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, net_mode); if (sk) sock_hold(sk);

@@ -333,6 +407,14 @@ 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, VSOCK_NET_MODE_GLOBAL); +} EXPORT_SYMBOL_GPL(vsock_find_connected_socket);

void vsock_remove_sock(struct vsock_sock *vsk) @@ -528,7 +610,7 @@ 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 +758,7 @@ 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 +778,8 @@ 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, + vsk->net_mode)) { found = true; break; } @@ -712,7 +796,8 @@ 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, + vsk->net_mode)) return -EADDRINUSE; }

@@ -836,6 +921,8 @@ static struct sock *__vsock_create(struct net *net, vsk->buffer_max_size = VSOCK_DEFAULT_BUFFER_MAX_SIZE; }

+ vsk->net_mode = vsock_net_mode(net); + return sk; }

@@ -1314,7 +1401,7 @@ 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 +1442,7 @@ 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 +1672,7 @@ 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 +2745,142 @@ 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) +{ + char data[VSOCK_NET_MODE_STR_MAX] = {0}; + enum vsock_net_mode mode; + struct ctl_table tmp; + struct net *net; + int ret; + + if (!table->data || !table->maxlen || !*lenp) { + *lenp = 0; + return 0; + } + + net = current->nsproxy->net_ns; + tmp = *table; + tmp.data = data; + + if (!write) { + const char *p; + + mode = vsock_net_mode(net); + + 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))) + mode = VSOCK_NET_MODE_GLOBAL; + else if (!strncmp(data, VSOCK_NET_MODE_STR_LOCAL, sizeof(data))) + mode = VSOCK_NET_MODE_LOCAL; + else + return -EINVAL; + + if (!vsock_net_write_mode(net, mode)) + return -EPERM; + + return 0; +} + +static struct ctl_table vsock_table[] = { + { + .procname = "ns_mode", + .data = &init_net.vsock.mode, + .maxlen = VSOCK_NET_MODE_STR_MAX, + .mode = 0644, + .proc_handler = vsock_net_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; + } + + 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) +{ + net->vsock.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 +2908,18 @@ static int __init vsock_init(void) goto err_unregister_proto; }

+ if (register_pernet_subsys(&vsock_sysctl_ops)) { + err = -ENOMEM; + goto err_unregister_sock; + } + + vsock_net_init(&init_net); 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 +2933,7 @@ 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..b2ade188c8c7 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 (vsk->net_mode != 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..f5123810192d 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 (vsk->net_mode != 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..e6391eb7cc1b 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 vsk->net_mode == 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..0ce44dc11708 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 (vsk->net_mode != 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 (vsk->net_mode != 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..afad27cf533a 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 vsk->net_mode == VSOCK_NET_MODE_GLOBAL; }

static void vsock_loopback_work(struct work_struct *work)

From: Bobby Eshleman bobbyeshleman@meta.com

Add the per-net vsock NS mode state. This only adds the structure for holding the mode and some of the functions for setting/getting and checking the mode, but does not integrate the functionality yet.

A "net_mode" field is added to vsock_sock to store the mode of the namespace when the vsock_sock was created. In order to evaluate namespace mode rules we need to know both a) which namespace the endpoints are in, and b) what mode that namespace had when the endpoints were created. This allows us to handle the changing of modes from global to local *after* a socket has been created by remembering that the mode was global when the socket was created. If we were to use the current net's mode instead, then the lookup would fail and the socket would break.

Reviewed-by: Stefano Garzarella sgarzare@redhat.com Signed-off-by: Bobby Eshleman bobbyeshleman@meta.com --- Changes in v10: - change mode_locked to int (Stefano)

Changes in v9: - use xchg(), WRITE_ONCE(), READ_ONCE() for mode and mode_locked (Stefano) - clarify mode0/mode1 meaning in vsock_net_check_mode() comment - remove spin lock in net->vsock (not used anymore) - change mode from u8 to enum vsock_net_mode in vsock_net_write_mode()

Changes in v7: - clarify vsock_net_check_mode() comments - change to `orig_net_mode == VSOCK_NET_MODE_GLOBAL && orig_net_mode == vsk->orig_net_mode` - remove extraneous explanation of `orig_net_mode` - rename `written` to `mode_locked` - rename `vsock_hdr` to `sysctl_hdr` - change `orig_net_mode` to `net_mode` - make vsock_net_check_mode() more generic by taking just net pointers and modes, instead of a vsock_sock ptr, for reuse by transports (e.g., vhost_vsock)

Changes in v6: - add orig_net_mode to store mode at creation time which will be used to avoid breakage when namespace changes mode during socket/VM lifespan

Changes in v5: - use /proc/sys/net/vsock/ns_mode instead of /proc/net/vsock_ns_mode - change from net->vsock.ns_mode to net->vsock.mode - change vsock_net_set_mode() to vsock_net_write_mode() - vsock_net_write_mode() returns bool for write success to avoid need to use vsock_net_mode_can_set() - remove vsock_net_mode_can_set() --- MAINTAINERS | 1 + include/net/af_vsock.h | 44 ++++++++++++++++++++++++++++++++++++++++++++ include/net/net_namespace.h | 4 ++++ include/net/netns/vsock.h | 17 +++++++++++++++++ 4 files changed, 66 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS index e9a8d945632b..b6ac6720d706 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -27105,6 +27105,7 @@ L: netdev@vger.kernel.org S: Maintained F: drivers/vhost/vsock.c F: include/linux/virtio_vsock.h +F: include/net/netns/vsock.h F: include/uapi/linux/virtio_vsock.h F: net/vmw_vsock/virtio_transport.c F: net/vmw_vsock/virtio_transport_common.c diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h index d40e978126e3..9b5bdd083b6f 100644 --- a/include/net/af_vsock.h +++ b/include/net/af_vsock.h @@ -10,6 +10,7 @@

#include <linux/kernel.h> #include <linux/workqueue.h> +#include <net/netns/vsock.h> #include <net/sock.h> #include <uapi/linux/vm_sockets.h>

@@ -65,6 +66,7 @@ struct vsock_sock { u32 peer_shutdown; bool sent_request; bool ignore_connecting_rst; + enum vsock_net_mode net_mode;

/* Protected by lock_sock(sk) */ u64 buffer_size; @@ -256,4 +258,46 @@ static inline bool vsock_msgzerocopy_allow(const struct vsock_transport *t) { return t->msgzerocopy_allow && t->msgzerocopy_allow(); } + +static inline enum vsock_net_mode vsock_net_mode(struct net *net) +{ + return READ_ONCE(net->vsock.mode); +} + +static inline bool vsock_net_write_mode(struct net *net, + enum vsock_net_mode mode) +{ + if (xchg(&net->vsock.mode_locked, 1)) + return false; + + WRITE_ONCE(net->vsock.mode, mode); + return true; +} + +/* Return true if two namespaces and modes pass the mode rules. Otherwise, + * return false. + * + * - ns0 and ns1 are the namespaces being checked. + * - mode0 and mode1 are the vsock namespace modes of ns0 and ns1 at the time + * the vsock objects were created. + * + * Read more about modes in the comment header of net/vmw_vsock/af_vsock.c. + */ +static inline bool vsock_net_check_mode(struct net *ns0, + enum vsock_net_mode mode0, + struct net *ns1, + enum vsock_net_mode mode1) +{ + /* Any vsocks within the same network namespace are always reachable, + * regardless of the mode. + */ + if (net_eq(ns0, ns1)) + return true; + + /* + * If the network namespaces differ, vsocks are only reachable if both + * were created in VSOCK_NET_MODE_GLOBAL mode. + */ + return mode0 == VSOCK_NET_MODE_GLOBAL && mode0 == mode1; +} #endif /* __AF_VSOCK_H__ */ diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h index cb664f6e3558..66d3de1d935f 100644 --- a/include/net/net_namespace.h +++ b/include/net/net_namespace.h @@ -37,6 +37,7 @@ #include <net/netns/smc.h> #include <net/netns/bpf.h> #include <net/netns/mctp.h> +#include <net/netns/vsock.h> #include <net/net_trackers.h> #include <linux/ns_common.h> #include <linux/idr.h> @@ -196,6 +197,9 @@ struct net { /* Move to a better place when the config guard is removed. */ struct mutex rtnl_mutex; #endif +#if IS_ENABLED(CONFIG_VSOCKETS) + struct netns_vsock vsock; +#endif } __randomize_layout;

#include <linux/seq_file_net.h> diff --git a/include/net/netns/vsock.h b/include/net/netns/vsock.h new file mode 100644 index 000000000000..c1a5e805949d --- /dev/null +++ b/include/net/netns/vsock.h @@ -0,0 +1,17 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __NET_NET_NAMESPACE_VSOCK_H +#define __NET_NET_NAMESPACE_VSOCK_H + +#include <linux/types.h> + +enum vsock_net_mode { + VSOCK_NET_MODE_GLOBAL, + VSOCK_NET_MODE_LOCAL, +}; + +struct netns_vsock { + struct ctl_table_header *sysctl_hdr; + enum vsock_net_mode mode; + int mode_locked; +}; +#endif /* __NET_NET_NAMESPACE_VSOCK_H */

From: Bobby Eshleman bobbyeshleman@meta.com

Add namespace support to vm management, ssh helpers, and vsock_test wrapper functions. This enables running VMs and test helpers in specific namespaces, which is required for upcoming namespace isolation tests.

The functions still work correctly within the init ns, though the caller must now pass "init_ns" explicitly.

No functional changes for existing tests. All have been updated to pass "init_ns" explicitly.

Affected functions (such as vm_start() and vm_ssh()) now wrap their commands with 'ip netns exec' when executing commands in non-init namespaces.

Reviewed-by: Stefano Garzarella sgarzare@redhat.com Signed-off-by: Bobby Eshleman bobbyeshleman@meta.com --- tools/testing/selftests/vsock/vmtest.sh | 93 +++++++++++++++++++++++---------- 1 file changed, 65 insertions(+), 28 deletions(-)

diff --git a/tools/testing/selftests/vsock/vmtest.sh b/tools/testing/selftests/vsock/vmtest.sh index f78cc574c274..4da91828a6a0 100755 --- a/tools/testing/selftests/vsock/vmtest.sh +++ b/tools/testing/selftests/vsock/vmtest.sh @@ -144,7 +144,18 @@ ns_set_mode() { }

vm_ssh() { - ssh -q -o UserKnownHostsFile=/dev/null -p ${SSH_HOST_PORT} localhost "$@" + local ns_exec + + if [[ "${1}" == init_ns ]]; then + ns_exec="" + else + ns_exec="ip netns exec ${1}" + fi + + shift + + ${ns_exec} ssh -q -o UserKnownHostsFile=/dev/null -p "${SSH_HOST_PORT}" localhost "$@" + return $? }

@@ -267,10 +278,12 @@ terminate_pidfiles() {

vm_start() { local pidfile=$1 + local ns=$2 local logfile=/dev/null local verbose_opt="" local kernel_opt="" local qemu_opts="" + local ns_exec="" local qemu

qemu=$(command -v "${QEMU}") @@ -291,7 +304,11 @@ vm_start() { kernel_opt="${KERNEL_CHECKOUT}" fi

- vng \ + if [[ "${ns}" != "init_ns" ]]; then + ns_exec="ip netns exec ${ns}" + fi + + ${ns_exec} vng \ --run \ ${kernel_opt} \ ${verbose_opt} \ @@ -306,6 +323,7 @@ vm_start() { }

vm_wait_for_ssh() { + local ns=$1 local i

i=0 @@ -313,7 +331,8 @@ vm_wait_for_ssh() { if [[ ${i} -gt ${WAIT_PERIOD_MAX} ]]; then die "Timed out waiting for guest ssh" fi - if vm_ssh -- true; then + + if vm_ssh "${ns}" -- true; then break fi i=$(( i + 1 )) @@ -347,30 +366,41 @@ wait_for_listener() }

vm_wait_for_listener() { - local port=$1 + local ns=$1 + local port=$2

- vm_ssh <<EOF + vm_ssh "${ns}" <<EOF $(declare -f wait_for_listener) wait_for_listener ${port} ${WAIT_PERIOD} ${WAIT_PERIOD_MAX} EOF }

host_wait_for_listener() { - local port=$1 + local ns=$1 + local port=$2

- wait_for_listener "${port}" "${WAIT_PERIOD}" "${WAIT_PERIOD_MAX}" + if [[ "${ns}" == "init_ns" ]]; then + wait_for_listener "${port}" "${WAIT_PERIOD}" "${WAIT_PERIOD_MAX}" + else + ip netns exec "${ns}" bash <<-EOF + $(declare -f wait_for_listener) + wait_for_listener ${port} ${WAIT_PERIOD} ${WAIT_PERIOD_MAX} + EOF + fi }

+ vm_vsock_test() { - local host=$1 - local cid=$2 - local port=$3 + local ns=$1 + local host=$2 + local cid=$3 + local port=$4 local rc

# log output and use pipefail to respect vsock_test errors set -o pipefail if [[ "${host}" != server ]]; then - vm_ssh -- "${VSOCK_TEST}" \ + vm_ssh "${ns}" -- "${VSOCK_TEST}" \ --mode=client \ --control-host="${host}" \ --peer-cid="${cid}" \ @@ -378,7 +408,7 @@ vm_vsock_test() { 2>&1 | log_guest rc=$? else - vm_ssh -- "${VSOCK_TEST}" \ + vm_ssh "${ns}" -- "${VSOCK_TEST}" \ --mode=server \ --peer-cid="${cid}" \ --control-port="${port}" \ @@ -390,7 +420,7 @@ vm_vsock_test() { return $rc fi

- vm_wait_for_listener "${port}" + vm_wait_for_listener "${ns}" "${port}" rc=$? fi set +o pipefail @@ -399,22 +429,28 @@ vm_vsock_test() { }

host_vsock_test() { - local host=$1 - local cid=$2 - local port=$3 + local ns=$1 + local host=$2 + local cid=$3 + local port=$4 local rc

+ local cmd="${VSOCK_TEST}" + if [[ "${ns}" != "init_ns" ]]; then + cmd="ip netns exec ${ns} ${cmd}" + fi + # log output and use pipefail to respect vsock_test errors set -o pipefail if [[ "${host}" != server ]]; then - ${VSOCK_TEST} \ + ${cmd} \ --mode=client \ --peer-cid="${cid}" \ --control-host="${host}" \ --control-port="${port}" 2>&1 | log_host rc=$? else - ${VSOCK_TEST} \ + ${cmd} \ --mode=server \ --peer-cid="${cid}" \ --control-port="${port}" 2>&1 | log_host & @@ -425,7 +461,7 @@ host_vsock_test() { return $rc fi

- host_wait_for_listener "${port}" + host_wait_for_listener "${ns}" "${port}" rc=$? fi set +o pipefail @@ -469,11 +505,11 @@ log_guest() { }

test_vm_server_host_client() { - if ! vm_vsock_test "server" 2 "${TEST_GUEST_PORT}"; then + if ! vm_vsock_test "init_ns" "server" 2 "${TEST_GUEST_PORT}"; then return "${KSFT_FAIL}" fi

- if ! host_vsock_test "127.0.0.1" "${VSOCK_CID}" "${TEST_HOST_PORT}"; then + if ! host_vsock_test "init_ns" "127.0.0.1" "${VSOCK_CID}" "${TEST_HOST_PORT}"; then return "${KSFT_FAIL}" fi

@@ -481,11 +517,11 @@ test_vm_server_host_client() { }

test_vm_client_host_server() { - if ! host_vsock_test "server" "${VSOCK_CID}" "${TEST_HOST_PORT_LISTENER}"; then + if ! host_vsock_test "init_ns" "server" "${VSOCK_CID}" "${TEST_HOST_PORT_LISTENER}"; then return "${KSFT_FAIL}" fi

- if ! vm_vsock_test "10.0.2.2" 2 "${TEST_HOST_PORT_LISTENER}"; then + if ! vm_vsock_test "init_ns" "10.0.2.2" 2 "${TEST_HOST_PORT_LISTENER}"; then return "${KSFT_FAIL}" fi

@@ -495,13 +531,14 @@ test_vm_client_host_server() { test_vm_loopback() { local port=60000 # non-forwarded local port

- vm_ssh -- modprobe vsock_loopback &> /dev/null || : + vm_ssh "init_ns" -- modprobe vsock_loopback &> /dev/null || :

- if ! vm_vsock_test "server" 1 "${port}"; then + if ! vm_vsock_test "init_ns" "server" 1 "${port}"; then return "${KSFT_FAIL}" fi

- if ! vm_vsock_test "127.0.0.1" 1 "${port}"; then + + if ! vm_vsock_test "init_ns" "127.0.0.1" 1 "${port}"; then return "${KSFT_FAIL}" fi

@@ -630,8 +667,8 @@ cnt_total=0 if shared_vm_tests_requested "${ARGS[@]}"; then log_host "Booting up VM" pidfile="$(create_pidfile)" - vm_start "${pidfile}" - vm_wait_for_ssh + vm_start "${pidfile}" "init_ns" + vm_wait_for_ssh "init_ns" log_host "VM booted up"

run_shared_vm_tests "${ARGS[@]}"

From: Bobby Eshleman bobbyeshleman@meta.com

Add tests for the /proc/sys/net/vsock/ns_mode interface. Namely, that it accepts "global" and "local" strings and enforces a write-once policy.

Start a convention of commenting the test name over the test description. Add test name comments over test descriptions that existed before this convention.

Add a check_netns() function that checks if the test requires namespaces and if the current kernel supports namespaces. Skip tests that require namespaces if the system does not have namespace support.

Add a test to verify that guest VMs with an active G2H transport (virtio-vsock) cannot set namespace mode to 'local'. This validates the mutual exclusion between G2H transports and LOCAL mode.

This patch is the first to add tests that do *not* re-use the same shared VM. For that reason, it adds a run_tests() function to run these tests and filter out the shared VM tests.

Reviewed-by: Stefano Garzarella sgarzare@redhat.com Signed-off-by: Bobby Eshleman bobbyeshleman@meta.com --- Changes in v12: - remove ns_vm_local_mode_rejected test, due to dropping that constraint

Changes in v11: - Document ns_ prefix above TEST_NAMES (Stefano)

Changes in v10: - Remove extraneous add_namespaces/del_namespaces calls. - Rename run_tests() to run_ns_tests() since it is designed to only run ns tests.

Changes in v9: - add test ns_vm_local_mode_rejected to check that guests cannot use local mode --- tools/testing/selftests/vsock/vmtest.sh | 118 +++++++++++++++++++++++++++++++- 1 file changed, 116 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/vsock/vmtest.sh b/tools/testing/selftests/vsock/vmtest.sh index e32997db322d..28b91b906cdc 100755 --- a/tools/testing/selftests/vsock/vmtest.sh +++ b/tools/testing/selftests/vsock/vmtest.sh @@ -41,14 +41,38 @@ readonly KERNEL_CMDLINE="\ virtme.ssh virtme_ssh_channel=tcp virtme_ssh_user=$USER \ " readonly LOG=$(mktemp /tmp/vsock_vmtest_XXXX.log) -readonly TEST_NAMES=(vm_server_host_client vm_client_host_server vm_loopback) + +# Namespace tests must use the ns_ prefix. This is checked in check_netns() and +# is used to determine if a test needs namespace setup before test execution. +readonly TEST_NAMES=( + vm_server_host_client + vm_client_host_server + vm_loopback + ns_host_vsock_ns_mode_ok + ns_host_vsock_ns_mode_write_once_ok +) readonly TEST_DESCS=( + # vm_server_host_client "Run vsock_test in server mode on the VM and in client mode on the host." + + # vm_client_host_server "Run vsock_test in client mode on the VM and in server mode on the host." + + # vm_loopback "Run vsock_test using the loopback transport in the VM." + + # ns_host_vsock_ns_mode_ok + "Check /proc/sys/net/vsock/ns_mode strings on the host." + + # ns_host_vsock_ns_mode_write_once_ok + "Check /proc/sys/net/vsock/ns_mode is write-once on the host." )

-readonly USE_SHARED_VM=(vm_server_host_client vm_client_host_server vm_loopback) +readonly USE_SHARED_VM=( + vm_server_host_client + vm_client_host_server + vm_loopback +) readonly NS_MODES=("local" "global")

VERBOSE=0 @@ -205,6 +229,20 @@ check_deps() { fi }

+check_netns() { + local tname=$1 + + # If the test requires NS support, check if NS support exists + # using /proc/self/ns + if [[ "${tname}" =~ ^ns_ ]] && + [[ ! -e /proc/self/ns ]]; then + log_host "No NS support detected for test ${tname}" + return 1 + fi + + return 0 +} + check_vng() { local tested_versions local version @@ -528,6 +566,32 @@ log_guest() { LOG_PREFIX=guest log "$@" }

+test_ns_host_vsock_ns_mode_ok() { + for mode in "${NS_MODES[@]}"; do + if ! ns_set_mode "${mode}0" "${mode}"; then + return "${KSFT_FAIL}" + fi + done + + return "${KSFT_PASS}" +} + +test_ns_host_vsock_ns_mode_write_once_ok() { + for mode in "${NS_MODES[@]}"; do + local ns="${mode}0" + if ! ns_set_mode "${ns}" "${mode}"; then + return "${KSFT_FAIL}" + fi + + # try writing again and expect failure + if ns_set_mode "${ns}" "${mode}"; then + return "${KSFT_FAIL}" + fi + done + + return "${KSFT_PASS}" +} + test_vm_server_host_client() { if ! vm_vsock_test "init_ns" "server" 2 "${TEST_GUEST_PORT}"; then return "${KSFT_FAIL}" @@ -601,6 +665,11 @@ run_shared_vm_tests() { continue fi

+ if ! check_netns "${arg}"; then + check_result "${KSFT_SKIP}" "${arg}" + continue + fi + run_shared_vm_test "${arg}" check_result "$?" "${arg}" done @@ -654,6 +723,49 @@ run_shared_vm_test() { return "${rc}" }

+run_ns_tests() { + for arg in "${ARGS[@]}"; do + if shared_vm_test "${arg}"; then + continue + fi + + if ! check_netns "${arg}"; then + check_result "${KSFT_SKIP}" "${arg}" + continue + fi + + add_namespaces + + name=$(echo "${arg}" | awk '{ print $1 }') + log_host "Executing test_${name}" + + host_oops_before=$(dmesg 2>/dev/null | grep -c -i 'Oops') + host_warn_before=$(dmesg --level=warn 2>/dev/null | grep -c -i 'vsock') + eval test_"${name}" + rc=$? + + host_oops_after=$(dmesg 2>/dev/null | grep -c -i 'Oops') + if [[ "${host_oops_after}" -gt "${host_oops_before}" ]]; then + echo "FAIL: kernel oops detected on host" | log_host + check_result "${KSFT_FAIL}" "${name}" + del_namespaces + continue + fi + + host_warn_after=$(dmesg --level=warn 2>/dev/null | grep -c -i 'vsock') + if [[ "${host_warn_after}" -gt "${host_warn_before}" ]]; then + echo "FAIL: kernel warning detected on host" | log_host + check_result "${KSFT_FAIL}" "${name}" + del_namespaces + continue + fi + + check_result "${rc}" "${name}" + + del_namespaces + done +} + BUILD=0 QEMU="qemu-system-$(uname -m)"

@@ -699,6 +811,8 @@ if shared_vm_tests_requested "${ARGS[@]}"; then terminate_pidfiles "${pidfile}" fi

+run_ns_tests "${ARGS[@]}" + echo "SUMMARY: PASS=${cnt_pass} SKIP=${cnt_skip} FAIL=${cnt_fail}" echo "Log: ${LOG}"

From: Bobby Eshleman bobbyeshleman@meta.com

These functions are reused by the VM tests to collect and compare dmesg warnings and oops counts. The future VM-specific tests use them heavily. This patches relies on vm_ssh() already supporting namespaces.

Reviewed-by: Stefano Garzarella sgarzare@redhat.com Signed-off-by: Bobby Eshleman bobbyeshleman@meta.com --- Changes in v11: - break these out into an earlier patch so that they can be used directly in new patches (instead of causing churn by adding this later) --- tools/testing/selftests/vsock/vmtest.sh | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/vsock/vmtest.sh b/tools/testing/selftests/vsock/vmtest.sh index 4da91828a6a0..1623e4da15e2 100755 --- a/tools/testing/selftests/vsock/vmtest.sh +++ b/tools/testing/selftests/vsock/vmtest.sh @@ -389,6 +389,17 @@ host_wait_for_listener() { fi }

+vm_dmesg_oops_count() { + local ns=$1 + + vm_ssh "${ns}" -- dmesg 2>/dev/null | grep -c -i 'Oops' +} + +vm_dmesg_warn_count() { + local ns=$1 + + vm_ssh "${ns}" -- dmesg --level=warn 2>/dev/null | grep -c -i 'vsock' +}

vm_vsock_test() { local ns=$1 @@ -596,8 +607,8 @@ run_shared_vm_test() {

host_oops_cnt_before=$(dmesg | grep -c -i 'Oops') host_warn_cnt_before=$(dmesg --level=warn | grep -c -i 'vsock') - vm_oops_cnt_before=$(vm_ssh -- dmesg | grep -c -i 'Oops') - vm_warn_cnt_before=$(vm_ssh -- dmesg --level=warn | grep -c -i 'vsock') + vm_oops_cnt_before=$(vm_dmesg_oops_count "init_ns") + vm_warn_cnt_before=$(vm_dmesg_warn_count "init_ns")

name=$(echo "${1}" | awk '{ print $1 }') eval test_"${name}" @@ -615,13 +626,13 @@ run_shared_vm_test() { rc=$KSFT_FAIL fi

- vm_oops_cnt_after=$(vm_ssh -- dmesg | grep -i 'Oops' | wc -l) + vm_oops_cnt_after=$(vm_dmesg_oops_count "init_ns") if [[ ${vm_oops_cnt_after} -gt ${vm_oops_cnt_before} ]]; then echo "FAIL: kernel oops detected on vm" | log_host rc=$KSFT_FAIL fi

- vm_warn_cnt_after=$(vm_ssh -- dmesg --level=warn | grep -c -i 'vsock') + vm_warn_cnt_after=$(vm_dmesg_warn_count "init_ns") if [[ ${vm_warn_cnt_after} -gt ${vm_warn_cnt_before} ]]; then echo "FAIL: kernel warning detected on vm" | log_host rc=$KSFT_FAIL

From: Bobby Eshleman bobbyeshleman@meta.com

Add tests to validate namespace correctness using vsock_test and socat. The vsock_test tool is used to validate expected success tests, but socat is used for expected failure tests. socat is used to ensure that connections are rejected outright instead of failing due to some other socket behavior (as tested in vsock_test). Additionally, socat is already required for tunneling TCP traffic from vsock_test. Using only one of the vsock_test tests like 'test_stream_client_close_client' would have yielded a similar result, but doing so wouldn't remove the socat dependency.

Additionally, check for the dependency socat. socat needs special handling beyond just checking if it is on the path because it must be compiled with support for both vsock and unix. The function check_socat() checks that this support exists.

Add more padding to test name printf strings because the tests added in this patch would otherwise overflow.

Add vm_dmesg_* helpers to encapsulate checking dmesg for oops and warnings.

Add ability to pass extra args to host-side vsock_test so that tests that cause false positives may be skipped with arg --skip.

Signed-off-by: Bobby Eshleman bobbyeshleman@meta.com --- Changes in v12: - add test skip (vsock_test test 29) when host_vsock_test() uses client mode in a local namespace. Test 29 causes a false positive to trigger.

Changes in v11: - add 'sleep "${WAIT_PERIOD}"' after any non-TCP socat LISTEN cmd (Stefano) - add host_wait_for_listener() after any socat TCP-LISTEN (Stefano) - reuse vm_dmesg_{oops,warn}_count() inside vm_dmesg_check() - fix copy-paste in test_ns_same_local_vm_connect_to_local_host_ok() (Stefano)

Changes in v10: - add vm_dmesg_start() and vm_dmesg_check()

Changes in v9: - consistent variable quoting --- tools/testing/selftests/vsock/vmtest.sh | 572 +++++++++++++++++++++++++++++++- 1 file changed, 568 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/vsock/vmtest.sh b/tools/testing/selftests/vsock/vmtest.sh index ec18eb5b4ccd..da9198dc8ab5 100755 --- a/tools/testing/selftests/vsock/vmtest.sh +++ b/tools/testing/selftests/vsock/vmtest.sh @@ -7,6 +7,7 @@ # * virtme-ng # * busybox-static (used by virtme-ng) # * qemu (used by virtme-ng) +# * socat # # shellcheck disable=SC2317,SC2119

@@ -54,6 +55,19 @@ readonly TEST_NAMES=( ns_local_same_cid_ok ns_global_local_same_cid_ok ns_local_global_same_cid_ok + ns_diff_global_host_connect_to_global_vm_ok + ns_diff_global_host_connect_to_local_vm_fails + ns_diff_global_vm_connect_to_global_host_ok + ns_diff_global_vm_connect_to_local_host_fails + ns_diff_local_host_connect_to_local_vm_fails + ns_diff_local_vm_connect_to_local_host_fails + ns_diff_global_to_local_loopback_local_fails + ns_diff_local_to_global_loopback_fails + ns_diff_local_to_local_loopback_fails + ns_diff_global_to_global_loopback_ok + ns_same_local_loopback_ok + ns_same_local_host_connect_to_local_vm_ok + ns_same_local_vm_connect_to_local_host_ok ) readonly TEST_DESCS=( # vm_server_host_client @@ -82,6 +96,45 @@ readonly TEST_DESCS=(

# ns_local_global_same_cid_ok "Check QEMU successfully starts one VM in a local ns and then another VM in a global ns with the same CID." + + # ns_diff_global_host_connect_to_global_vm_ok + "Run vsock_test client in global ns with server in VM in another global ns." + + # ns_diff_global_host_connect_to_local_vm_fails + "Run socat to test a process in a global ns fails to connect to a VM in a local ns." + + # ns_diff_global_vm_connect_to_global_host_ok + "Run vsock_test client in VM in a global ns with server in another global ns." + + # ns_diff_global_vm_connect_to_local_host_fails + "Run socat to test a VM in a global ns fails to connect to a host process in a local ns." + + # ns_diff_local_host_connect_to_local_vm_fails + "Run socat to test a host process in a local ns fails to connect to a VM in another local ns." + + # ns_diff_local_vm_connect_to_local_host_fails + "Run socat to test a VM in a local ns fails to connect to a host process in another local ns." + + # ns_diff_global_to_local_loopback_local_fails + "Run socat to test a loopback vsock in a global ns fails to connect to a vsock in a local ns." + + # ns_diff_local_to_global_loopback_fails + "Run socat to test a loopback vsock in a local ns fails to connect to a vsock in a global ns." + + # ns_diff_local_to_local_loopback_fails + "Run socat to test a loopback vsock in a local ns fails to connect to a vsock in another local ns." + + # ns_diff_global_to_global_loopback_ok + "Run socat to test a loopback vsock in a global ns successfully connects to a vsock in another global ns." + + # ns_same_local_loopback_ok + "Run socat to test a loopback vsock in a local ns successfully connects to a vsock in the same ns." + + # ns_same_local_host_connect_to_local_vm_ok + "Run vsock_test client in a local ns with server in VM in same ns." + + # ns_same_local_vm_connect_to_local_host_ok + "Run vsock_test client in VM in a local ns with server in same ns." )

readonly USE_SHARED_VM=( @@ -112,7 +165,7 @@ usage() { for ((i = 0; i < ${#TEST_NAMES[@]}; i++)); do name=${TEST_NAMES[${i}]} desc=${TEST_DESCS[${i}]} - printf "\t%-35s%-35s\n" "${name}" "${desc}" + printf "\t%-55s%-35s\n" "${name}" "${desc}" done echo

@@ -231,7 +284,7 @@ check_args() { }

check_deps() { - for dep in vng ${QEMU} busybox pkill ssh ss; do + for dep in vng ${QEMU} busybox pkill ssh ss socat; do if [[ ! -x $(command -v "${dep}") ]]; then echo -e "skip: dependency ${dep} not found!\n" exit "${KSFT_SKIP}" @@ -282,6 +335,20 @@ check_vng() { fi }

+check_socat() { + local support_string + + support_string="$(socat -V)" + + if [[ "${support_string}" != *"WITH_VSOCK 1"* ]]; then + die "err: socat is missing vsock support" + fi + + if [[ "${support_string}" != *"WITH_UNIX 1"* ]]; then + die "err: socat is missing unix support" + fi +} + handle_build() { if [[ ! "${BUILD}" -eq 1 ]]; then return @@ -330,6 +397,14 @@ terminate_pidfiles() { done }

+terminate_pids() { + local pid + + for pid in "$@"; do + kill -SIGTERM "${pid}" &>/dev/null || : + done +} + vm_start() { local pidfile=$1 local ns=$2 @@ -468,6 +543,28 @@ vm_dmesg_warn_count() { vm_ssh "${ns}" -- dmesg --level=warn 2>/dev/null | grep -c -i 'vsock' }

+vm_dmesg_check() { + local pidfile=$1 + local ns=$2 + local oops_before=$3 + local warn_before=$4 + local oops_after warn_after + + oops_after=$(vm_dmesg_oops_count "${ns}") + if [[ "${oops_after}" -gt "${oops_before}" ]]; then + echo "FAIL: kernel oops detected on vm in ns ${ns}" | log_host + return 1 + fi + + warn_after=$(vm_dmesg_warn_count "${ns}") + if [[ "${warn_after}" -gt "${warn_before}" ]]; then + echo "FAIL: kernel warning detected on vm in ns ${ns}" | log_host + return 1 + fi + + return 0 +} + vm_vsock_test() { local ns=$1 local host=$2 @@ -511,6 +608,8 @@ host_vsock_test() { local host=$2 local cid=$3 local port=$4 + shift 4 + local extra_args=("$@") local rc

local cmd="${VSOCK_TEST}" @@ -525,13 +624,15 @@ host_vsock_test() { --mode=client \ --peer-cid="${cid}" \ --control-host="${host}" \ - --control-port="${port}" 2>&1 | log_host + --control-port="${port}" \ + "${extra_args[@]}" 2>&1 | log_host rc=$? else ${cmd} \ --mode=server \ --peer-cid="${cid}" \ - --control-port="${port}" 2>&1 | log_host & + --control-port="${port}" \ + "${extra_args[@]}" 2>&1 | log_host & rc=$?

if [[ $rc -ne 0 ]]; then @@ -592,6 +693,468 @@ test_ns_host_vsock_ns_mode_ok() { return "${KSFT_PASS}" }

+test_ns_diff_global_host_connect_to_global_vm_ok() { + local oops_before warn_before + local pids pid pidfile + local ns0 ns1 port + declare -a pids + local unixfile + ns0="global0" + ns1="global1" + port=1234 + local rc + + init_namespaces + + pidfile="$(create_pidfile)" + + if ! vm_start "${pidfile}" "${ns0}"; then + return "${KSFT_FAIL}" + fi + + vm_wait_for_ssh "${ns0}" + oops_before=$(vm_dmesg_oops_count "${ns0}") + warn_before=$(vm_dmesg_warn_count "${ns0}") + + unixfile=$(mktemp -u /tmp/XXXX.sock) + ip netns exec "${ns1}" \ + socat TCP-LISTEN:"${TEST_HOST_PORT}",fork \ + UNIX-CONNECT:"${unixfile}" & + pids+=($!) + host_wait_for_listener "${ns1}" "${TEST_HOST_PORT}" "tcp" + + ip netns exec "${ns0}" socat UNIX-LISTEN:"${unixfile}",fork \ + TCP-CONNECT:localhost:"${TEST_HOST_PORT}" & + pids+=($!) + host_wait_for_listener "${ns0}" "${unixfile}" "unix" + + vm_vsock_test "${ns0}" "server" 2 "${TEST_GUEST_PORT}" + vm_wait_for_listener "${ns0}" "${TEST_GUEST_PORT}" "tcp" + host_vsock_test "${ns1}" "127.0.0.1" "${VSOCK_CID}" "${TEST_HOST_PORT}" + rc=$? + + vm_dmesg_check "${pidfile}" "${ns0}" "${oops_before}" "${warn_before}" + dmesg_rc=$? + + terminate_pids "${pids[@]}" + terminate_pidfiles "${pidfile}" + + if [[ "${rc}" -ne 0 ]] || [[ "${dmesg_rc}" -ne 0 ]]; then + return "${KSFT_FAIL}" + fi + + return "${KSFT_PASS}" +} + +test_ns_diff_global_host_connect_to_local_vm_fails() { + local oops_before warn_before + local ns0="global0" + local ns1="local0" + local port=12345 + local dmesg_rc + local pidfile + local result + local pid + + init_namespaces + + outfile=$(mktemp) + + pidfile="$(create_pidfile)" + if ! vm_start "${pidfile}" "${ns1}"; then + log_host "failed to start vm (cid=${VSOCK_CID}, ns=${ns0})" + return "${KSFT_FAIL}" + fi + + vm_wait_for_ssh "${ns1}" + oops_before=$(vm_dmesg_oops_count "${ns1}") + warn_before=$(vm_dmesg_warn_count "${ns1}") + + vm_ssh "${ns1}" -- socat VSOCK-LISTEN:"${port}" STDOUT > "${outfile}" & + vm_wait_for_listener "${ns1}" "${port}" "vsock" + echo TEST | ip netns exec "${ns0}" \ + socat STDIN VSOCK-CONNECT:"${VSOCK_CID}":"${port}" 2>/dev/null + + vm_dmesg_check "${pidfile}" "${ns1}" "${oops_before}" "${warn_before}" + dmesg_rc=$? + + terminate_pidfiles "${pidfile}" + result=$(cat "${outfile}") + rm -f "${outfile}" + + if [[ "${result}" == "TEST" ]] || [[ "${dmesg_rc}" -ne 0 ]]; then + return "${KSFT_FAIL}" + fi + + return "${KSFT_PASS}" +} + +test_ns_diff_global_vm_connect_to_global_host_ok() { + local oops_before warn_before + local ns0="global0" + local ns1="global1" + local port=12345 + local unixfile + local dmesg_rc + local pidfile + local pids + local rc + + init_namespaces + + declare -a pids + + log_host "Setup socat bridge from ns ${ns0} to ns ${ns1} over port ${port}" + + unixfile=$(mktemp -u /tmp/XXXX.sock) + + ip netns exec "${ns0}" \ + socat TCP-LISTEN:"${port}" UNIX-CONNECT:"${unixfile}" & + pids+=($!) + host_wait_for_listener "${ns0}" "${port}" "tcp" + + ip netns exec "${ns1}" \ + socat UNIX-LISTEN:"${unixfile}" TCP-CONNECT:127.0.0.1:"${port}" & + pids+=($!) + host_wait_for_listener "${ns1}" "${unixfile}" "unix" + + log_host "Launching ${VSOCK_TEST} in ns ${ns1}" + host_vsock_test "${ns1}" "server" "${VSOCK_CID}" "${port}" + + pidfile="$(create_pidfile)" + if ! vm_start "${pidfile}" "${ns0}"; then + log_host "failed to start vm (cid=${cid}, ns=${ns0})" + terminate_pids "${pids[@]}" + rm -f "${unixfile}" + return "${KSFT_FAIL}" + fi + + vm_wait_for_ssh "${ns0}" + + oops_before=$(vm_dmesg_oops_count "${ns0}") + warn_before=$(vm_dmesg_warn_count "${ns0}") + + vm_vsock_test "${ns0}" "10.0.2.2" 2 "${port}" + rc=$? + + vm_dmesg_check "${pidfile}" "${ns0}" "${oops_before}" "${warn_before}" + dmesg_rc=$? + + terminate_pidfiles "${pidfile}" + terminate_pids "${pids[@]}" + rm -f "${unixfile}" + + if [[ "${rc}" -ne 0 ]] || [[ "${dmesg_rc}" -ne 0 ]]; then + return "${KSFT_FAIL}" + fi + + return "${KSFT_PASS}" + +} + +test_ns_diff_global_vm_connect_to_local_host_fails() { + local ns0="global0" + local ns1="local0" + local port=12345 + local oops_before warn_before + local dmesg_rc + local pidfile + local result + local pid + + init_namespaces + + log_host "Launching socat in ns ${ns1}" + outfile=$(mktemp) + + ip netns exec "${ns1}" socat VSOCK-LISTEN:"${port}" STDOUT &> "${outfile}" & + pid=$! + host_wait_for_listener "${ns1}" "${port}" "vsock" + + pidfile="$(create_pidfile)" + if ! vm_start "${pidfile}" "${ns0}"; then + log_host "failed to start vm (cid=${cid}, ns=${ns0})" + terminate_pids "${pid}" + rm -f "${outfile}" + return "${KSFT_FAIL}" + fi + + vm_wait_for_ssh "${ns0}" + + oops_before=$(vm_dmesg_oops_count "${ns0}") + warn_before=$(vm_dmesg_warn_count "${ns0}") + + vm_ssh "${ns0}" -- \ + bash -c "echo TEST | socat STDIN VSOCK-CONNECT:2:${port}" 2>&1 | log_guest + + vm_dmesg_check "${pidfile}" "${ns0}" "${oops_before}" "${warn_before}" + dmesg_rc=$? + + terminate_pidfiles "${pidfile}" + terminate_pids "${pid}" + + result=$(cat "${outfile}") + rm -f "${outfile}" + + if [[ "${result}" != TEST ]] && [[ "${dmesg_rc}" -eq 0 ]]; then + return "${KSFT_PASS}" + fi + + return "${KSFT_FAIL}" +} + +test_ns_diff_local_host_connect_to_local_vm_fails() { + local ns0="local0" + local ns1="local1" + local port=12345 + local oops_before warn_before + local dmesg_rc + local pidfile + local result + local pid + + init_namespaces + + outfile=$(mktemp) + + pidfile="$(create_pidfile)" + if ! vm_start "${pidfile}" "${ns1}"; then + log_host "failed to start vm (cid=${cid}, ns=${ns0})" + return "${KSFT_FAIL}" + fi + + vm_wait_for_ssh "${ns1}" + oops_before=$(vm_dmesg_oops_count "${ns1}") + warn_before=$(vm_dmesg_warn_count "${ns1}") + + vm_ssh "${ns1}" -- socat VSOCK-LISTEN:"${port}" STDOUT > "${outfile}" & + vm_wait_for_listener "${ns1}" "${port}" "vsock" + + echo TEST | ip netns exec "${ns0}" \ + socat STDIN VSOCK-CONNECT:"${VSOCK_CID}":"${port}" 2>/dev/null + + vm_dmesg_check "${pidfile}" "${ns1}" "${oops_before}" "${warn_before}" + dmesg_rc=$? + + terminate_pidfiles "${pidfile}" + + result=$(cat "${outfile}") + rm -f "${outfile}" + + if [[ "${result}" != TEST ]] && [[ "${dmesg_rc}" -eq 0 ]]; then + return "${KSFT_PASS}" + fi + + return "${KSFT_FAIL}" +} + +test_ns_diff_local_vm_connect_to_local_host_fails() { + local oops_before warn_before + local ns0="local0" + local ns1="local1" + local port=12345 + local dmesg_rc + local pidfile + local result + local pid + + init_namespaces + + log_host "Launching socat in ns ${ns1}" + outfile=$(mktemp) + ip netns exec "${ns1}" socat VSOCK-LISTEN:"${port}" STDOUT &> "${outfile}" & + pid=$! + host_wait_for_listener "${ns1}" "${port}" "vsock" + + pidfile="$(create_pidfile)" + if ! vm_start "${pidfile}" "${ns0}"; then + log_host "failed to start vm (cid=${cid}, ns=${ns0})" + rm -f "${outfile}" + return "${KSFT_FAIL}" + fi + + vm_wait_for_ssh "${ns0}" + oops_before=$(vm_dmesg_oops_count "${ns0}") + warn_before=$(vm_dmesg_warn_count "${ns0}") + + vm_ssh "${ns0}" -- \ + bash -c "echo TEST | socat STDIN VSOCK-CONNECT:2:${port}" 2>&1 | log_guest + + vm_dmesg_check "${pidfile}" "${ns0}" "${oops_before}" "${warn_before}" + dmesg_rc=$? + + terminate_pidfiles "${pidfile}" + terminate_pids "${pid}" + + result=$(cat "${outfile}") + rm -f "${outfile}" + + if [[ "${result}" != TEST ]] && [[ "${dmesg_rc}" -eq 0 ]]; then + return "${KSFT_PASS}" + fi + + return "${KSFT_FAIL}" +} + +__test_loopback_two_netns() { + local ns0=$1 + local ns1=$2 + local port=12345 + local result + local pid + + modprobe vsock_loopback &> /dev/null || : + + log_host "Launching socat in ns ${ns1}" + outfile=$(mktemp) + + ip netns exec "${ns1}" socat VSOCK-LISTEN:"${port}" STDOUT > "${outfile}" 2>/dev/null & + pid=$! + host_wait_for_listener "${ns1}" "${port}" "vsock" + + log_host "Launching socat in ns ${ns0}" + echo TEST | ip netns exec "${ns0}" socat STDIN VSOCK-CONNECT:1:"${port}" 2>/dev/null + terminate_pids "${pid}" + + result=$(cat "${outfile}") + rm -f "${outfile}" + + if [[ "${result}" == TEST ]]; then + return 0 + fi + + return 1 +} + +test_ns_diff_global_to_local_loopback_local_fails() { + init_namespaces + + if ! __test_loopback_two_netns "global0" "local0"; then + return "${KSFT_PASS}" + fi + + return "${KSFT_FAIL}" +} + +test_ns_diff_local_to_global_loopback_fails() { + init_namespaces + + if ! __test_loopback_two_netns "local0" "global0"; then + return "${KSFT_PASS}" + fi + + return "${KSFT_FAIL}" +} + +test_ns_diff_local_to_local_loopback_fails() { + init_namespaces + + if ! __test_loopback_two_netns "local0" "local1"; then + return "${KSFT_PASS}" + fi + + return "${KSFT_FAIL}" +} + +test_ns_diff_global_to_global_loopback_ok() { + init_namespaces + + if __test_loopback_two_netns "global0" "global1"; then + return "${KSFT_PASS}" + fi + + return "${KSFT_FAIL}" +} + +test_ns_same_local_loopback_ok() { + init_namespaces + + if __test_loopback_two_netns "local0" "local0"; then + return "${KSFT_PASS}" + fi + + return "${KSFT_FAIL}" +} + +test_ns_same_local_host_connect_to_local_vm_ok() { + local oops_before warn_before + local ns="local0" + local port=1234 + local dmesg_rc + local pidfile + local rc + + init_namespaces + + pidfile="$(create_pidfile)" + + if ! vm_start "${pidfile}" "${ns}"; then + return "${KSFT_FAIL}" + fi + + vm_wait_for_ssh "${ns}" + oops_before=$(vm_dmesg_oops_count "${ns}") + warn_before=$(vm_dmesg_warn_count "${ns}") + + vm_vsock_test "${ns}" "server" 2 "${TEST_GUEST_PORT}" + + # Skip test 29 (transport release use-after-free): This test attempts + # binding both G2H and H2G CIDs. Because virtio-vsock (G2H) doesn't + # support local namespaces the test will fail when + # transport_g2h->stream_allow() returns false. This edge case only + # happens for vsock_test in client mode on the host in a local + # namespace. This is a false positive. + host_vsock_test "${ns}" "127.0.0.1" "${VSOCK_CID}" "${TEST_HOST_PORT}" --skip=29 + rc=$? + + vm_dmesg_check "${pidfile}" "${ns}" "${oops_before}" "${warn_before}" + dmesg_rc=$? + + terminate_pidfiles "${pidfile}" + + if [[ "${rc}" -ne 0 ]] || [[ "${dmesg_rc}" -ne 0 ]]; then + return "${KSFT_FAIL}" + fi + + return "${KSFT_PASS}" +} + +test_ns_same_local_vm_connect_to_local_host_ok() { + local oops_before warn_before + local ns="local0" + local port=1234 + local dmesg_rc + local pidfile + local rc + + init_namespaces + + pidfile="$(create_pidfile)" + + if ! vm_start "${pidfile}" "${ns}"; then + return "${KSFT_FAIL}" + fi + + vm_wait_for_ssh "${ns}" + oops_before=$(vm_dmesg_oops_count "${ns}") + warn_before=$(vm_dmesg_warn_count "${ns}") + + host_vsock_test "${ns}" "server" "${VSOCK_CID}" "${port}" + vm_vsock_test "${ns}" "10.0.2.2" 2 "${port}" + rc=$? + + vm_dmesg_check "${pidfile}" "${ns}" "${oops_before}" "${warn_before}" + dmesg_rc=$? + + terminate_pidfiles "${pidfile}" + + if [[ "${rc}" -ne 0 ]] || [[ "${dmesg_rc}" -ne 0 ]]; then + return "${KSFT_FAIL}" + fi + + return "${KSFT_PASS}" +} + namespaces_can_boot_same_cid() { local ns0=$1 local ns1=$2 @@ -869,6 +1432,7 @@ fi check_args "${ARGS[@]}" check_deps check_vng +check_socat handle_build

echo "1..${#ARGS[@]}"

On Wed, Nov 26, 2025 at 11:47:33PM -0800, Bobby Eshleman wrote:

From: Bobby Eshleman bobbyeshleman@meta.com

Add netns support to loopback and vhost. Keep netns disabled for virtio-vsock, but add necessary changes to comply with common API updates.

This is the patch in the series when vhost-vsock namespaces actually come online. Hence, vhost_transport_supports_local_mode() is switched to return true.

Signed-off-by: Bobby Eshleman bobbyeshleman@meta.com

Changes in v12:

• change seqpacket_allow() and stream_allow() to return true for

loopback and vhost (Stefano)

Changes in v11:

• reorder with the skb ownership patch for loopback (Stefano)
• toggle vhost_transport_supports_local_mode() to true

Changes in v10:

• Splitting patches complicates the series with meaningless placeholder

values that eventually get replaced anyway, so to avoid that this patch combines into one. Links to previous patches here:

• Link: https://lore.kernel.org/all/20251111-vsock-vmtest-v9-3-852787a37bed@meta.com...
• Link: https://lore.kernel.org/all/20251111-vsock-vmtest-v9-6-852787a37bed@meta.com...
• Link: https://lore.kernel.org/all/20251111-vsock-vmtest-v9-7-852787a37bed@meta.com...
• remove placeholder values (Stefano)
• update comment describe net/net_mode for

virtio_transport_reset_no_sock()

drivers/vhost/vsock.c | 56 +++++++++++++++++++++-------- include/linux/virtio_vsock.h | 8 +++-- net/vmw_vsock/virtio_transport.c | 10 ++++-- net/vmw_vsock/virtio_transport_common.c | 63 ++++++++++++++++++++++++--------- net/vmw_vsock/vsock_loopback.c | 19 +++++++--- 5 files changed, 118 insertions(+), 38 deletions(-)

diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c index 83937e1d63fa..82cb9ec09e78 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 +84,10 @@ 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;

@@ -269,7 +276,8 @@ static void vhost_transport_send_pkt_work(struct vhost_work *work) }

static int -vhost_transport_send_pkt(struct sk_buff *skb) +vhost_transport_send_pkt(struct sk_buff *skb, struct net *net,

• 	 enum vsock_net_mode net_mode)
  

{ struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb); struct vhost_vsock *vsock; @@ -278,7 +286,7 @@ vhost_transport_send_pkt(struct sk_buff *skb) 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, 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;

@@ -407,6 +416,12 @@ static bool vhost_transport_msgzerocopy_allow(void) static bool vhost_transport_seqpacket_allow(struct vsock_sock *vsk, u32 remote_cid);

+static bool +vhost_transport_stream_allow(struct vsock_sock *vsk, u32 cid, u32 port) +{

• return true;

+}

static struct virtio_transport vhost_transport = { .transport = { .module = THIS_MODULE, @@ -431,7 +446,7 @@ static struct virtio_transport vhost_transport = { .stream_has_space = virtio_transport_stream_has_space, .stream_rcvhiwat = virtio_transport_stream_rcvhiwat, .stream_is_active = virtio_transport_stream_is_active,

• .stream_allow             = virtio_transport_stream_allow,
  

• .stream_allow             = vhost_transport_stream_allow,
  
  

  .seqpacket_dequeue = virtio_transport_seqpacket_dequeue, .seqpacket_enqueue = virtio_transport_seqpacket_enqueue,

@@ -464,14 +479,12 @@ 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;

• if (vsk->net_mode != VSOCK_NET_MODE_GLOBAL)

• return 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;

@@ -542,7 +555,8 @@ static void vhost_vsock_handle_tx_kick(struct vhost_work *work) if (le64_to_cpu(hdr->src_cid) == vsock->guest_cid && le64_to_cpu(hdr->dst_cid) == vhost_transport_get_local_cid())

• 	virtio_transport_recv_pkt(&vhost_transport, skb);
  

• 	virtio_transport_recv_pkt(&vhost_transport, skb,
  

• 				  vsock->net, vsock->net_mode);
  

  else kfree_skb(skb);

@@ -659,6 +673,7 @@ 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

@@ -674,6 +689,17 @@ 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);
• /* Store the mode of the namespace at the time of creation. If this

• * namespace later changes from "global" to "local", we want this vsock
  

• * to continue operating normally and not suddenly break. For that
  

• * reason, we save the mode here and later use it when performing
  

• * socket lookups with vsock_net_check_mode() (see vhost_vsock_get()).
  

• */
  

• vsock->net_mode = vsock_net_mode(net);
• vsock->guest_cid = 0; /* no CID assigned yet */ vsock->seqpacket_allow = false;

@@ -713,7 +739,8 @@ 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

@@ -758,6 +785,7 @@ 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;

@@ -784,7 +812,7 @@ 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;

diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h index 1845e8d4f78d..7ea264dcfff7 100644 --- a/include/linux/virtio_vsock.h +++ b/include/linux/virtio_vsock.h @@ -173,6 +173,8 @@ struct virtio_vsock_pkt_info { u32 remote_cid, remote_port; struct vsock_sock *vsk; struct msghdr *msg;

• struct net *net;
• enum vsock_net_mode net_mode; u32 pkt_len; u16 type; u16 op;

@@ -185,7 +187,8 @@ struct virtio_transport { struct vsock_transport transport;

/* Takes ownership of the packet */

• int (*send_pkt)(struct sk_buff *skb);

• int (*send_pkt)(struct sk_buff *skb, struct net *net,

• 	enum vsock_net_mode net_mode);
  
  

  /* Used in MSG_ZEROCOPY mode. Checks, that provided data

  • (number of buffers) could be transmitted with zerocopy

@@ -280,7 +283,8 @@ virtio_transport_dgram_enqueue(struct vsock_sock *vsk, void virtio_transport_destruct(struct vsock_sock *vsk);

void virtio_transport_recv_pkt(struct virtio_transport *t,

• 	       struct sk_buff *skb);
  

• 	       struct sk_buff *skb, struct net *net,
  

• 	       enum vsock_net_mode net_mode);
  

void virtio_transport_inc_tx_pkt(struct virtio_vsock_sock *vvs, struct sk_buff *skb); u32 virtio_transport_get_credit(struct virtio_vsock_sock *vvs, u32 wanted); void virtio_transport_put_credit(struct virtio_vsock_sock *vvs, u32 credit); diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c index f5123810192d..3ff695740108 100644 --- a/net/vmw_vsock/virtio_transport.c +++ b/net/vmw_vsock/virtio_transport.c @@ -231,7 +231,8 @@ static int virtio_transport_send_skb_fast_path(struct virtio_vsock *vsock, struc }

static int -virtio_transport_send_pkt(struct sk_buff *skb) +virtio_transport_send_pkt(struct sk_buff *skb, struct net *net,

• 	  enum vsock_net_mode net_mode)
  

{ struct virtio_vsock_hdr *hdr; struct virtio_vsock *vsock; @@ -665,7 +666,12 @@ static void virtio_transport_rx_work(struct work_struct *work) virtio_vsock_skb_put(skb, payload_len);

	virtio_transport_deliver_tap_pkt(skb);

• 	virtio_transport_recv_pkt(&virtio_transport, skb);
  

• 	/* Force virtio-transport into global mode since it
  

• 	 * does not yet support local-mode namespacing.
  

• 	 */
  

• 	virtio_transport_recv_pkt(&virtio_transport, skb,
  

• 				  NULL, VSOCK_NET_MODE_GLOBAL);
  

This is related to the discussion of the previous patch I guess. So if I get it right, it LGTM!

}

} while (!virtqueue_enable_cb(vq));

diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c index de71e2b3f77e..a818152d8b79 100644 --- a/net/vmw_vsock/virtio_transport_common.c +++ b/net/vmw_vsock/virtio_transport_common.c @@ -413,7 +413,7 @@ static int virtio_transport_send_pkt_info(struct vsock_sock *vsk,

virtio_transport_inc_tx_pkt(vvs, skb);

• ret = t_ops->send_pkt(skb);
  

• ret = t_ops->send_pkt(skb, info->net, info->net_mode);
  

  if (ret < 0) break;

@@ -527,6 +527,8 @@ static int virtio_transport_send_credit_update(struct vsock_sock *vsk) struct virtio_vsock_pkt_info info = { .op = VIRTIO_VSOCK_OP_CREDIT_UPDATE, .vsk = vsk,

• .net = sock_net(sk_vsock(vsk)),
  

• .net_mode = vsk->net_mode,
  

  };

  return virtio_transport_send_pkt_info(vsk, &info);

@@ -1067,6 +1069,8 @@ int virtio_transport_connect(struct vsock_sock *vsk) struct virtio_vsock_pkt_info info = { .op = VIRTIO_VSOCK_OP_REQUEST, .vsk = vsk,

• .net = sock_net(sk_vsock(vsk)),
  

• .net_mode = vsk->net_mode,
  

  };

  return virtio_transport_send_pkt_info(vsk, &info);

@@ -1082,6 +1086,8 @@ int virtio_transport_shutdown(struct vsock_sock *vsk, int mode) (mode & SEND_SHUTDOWN ? VIRTIO_VSOCK_SHUTDOWN_SEND : 0), .vsk = vsk,

• .net = sock_net(sk_vsock(vsk)),
  

• .net_mode = vsk->net_mode,
  

  };

  return virtio_transport_send_pkt_info(vsk, &info);

@@ -1108,6 +1114,8 @@ virtio_transport_stream_enqueue(struct vsock_sock *vsk, .msg = msg, .pkt_len = len, .vsk = vsk,

• .net = sock_net(sk_vsock(vsk)),
  

• .net_mode = vsk->net_mode,
  

  };

  return virtio_transport_send_pkt_info(vsk, &info);

@@ -1145,6 +1153,8 @@ static int virtio_transport_reset(struct vsock_sock *vsk, .op = VIRTIO_VSOCK_OP_RST, .reply = !!skb, .vsk = vsk,

• .net = sock_net(sk_vsock(vsk)),
  

• .net_mode = vsk->net_mode,
  

  };

  /* Send RST only if the original pkt is not a RST pkt */

@@ -1156,9 +1166,14 @@ static int virtio_transport_reset(struct vsock_sock *vsk,

/* Normally packets are associated with a socket. There may be no socket if an

• attempt was made to connect to a socket that does not exist.

• • net and net_mode refer to the namespace of whoever sent the invalid message.
• • For loopback, this is the namespace of the socket. For vhost, this is the
• • namespace of the VM (i.e., vhost_vsock).

*/ static int virtio_transport_reset_no_sock(const struct virtio_transport *t,

• 			  struct sk_buff *skb)
  

• 			  struct sk_buff *skb, struct net *net,
  

• 			  enum vsock_net_mode net_mode)
  

{ struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb); struct virtio_vsock_pkt_info info = { @@ -1171,6 +1186,13 @@ static int virtio_transport_reset_no_sock(const struct virtio_transport *t, * sock_net(sk) until the reply skb is freed. */ .vsk = vsock_sk(skb->sk),

• /* net or net_mode are not defined here because we pass
  

•  * net and net_mode directly to t->send_pkt(), instead of
  

•  * relying on virtio_transport_send_pkt_info() to pass them to
  

•  * t->send_pkt(). They are not needed by
  

•  * virtio_transport_alloc_skb().
  

•  */
  

  }; struct sk_buff *reply;

@@ -1189,7 +1211,7 @@ static int virtio_transport_reset_no_sock(const struct virtio_transport *t, if (!reply) return -ENOMEM;

• return t->send_pkt(reply);

• return t->send_pkt(reply, net, net_mode);

}

/* This function should be called with sk_lock held and SOCK_DONE set */ @@ -1471,6 +1493,8 @@ virtio_transport_send_response(struct vsock_sock *vsk, .remote_port = le32_to_cpu(hdr->src_port), .reply = true, .vsk = vsk,

• .net = sock_net(sk_vsock(vsk)),
  

• .net_mode = vsk->net_mode,
  

  };

  return virtio_transport_send_pkt_info(vsk, &info);

@@ -1513,12 +1537,14 @@ virtio_transport_recv_listen(struct sock *sk, struct sk_buff *skb, int ret;

if (le16_to_cpu(hdr->op) != VIRTIO_VSOCK_OP_REQUEST) {

• virtio_transport_reset_no_sock(t, skb);
  

• virtio_transport_reset_no_sock(t, skb, sock_net(sk),
  

• 			       vsk->net_mode);
  

  return -EINVAL; }

  if (sk_acceptq_is_full(sk)) {

• virtio_transport_reset_no_sock(t, skb);
  

• virtio_transport_reset_no_sock(t, skb, sock_net(sk),
  

• 			       vsk->net_mode);
  

  return -ENOMEM; }

@@ -1526,13 +1552,15 @@ virtio_transport_recv_listen(struct sock *sk, struct sk_buff *skb, * Subsequent enqueues would lead to a memory leak. */ if (sk->sk_shutdown == SHUTDOWN_MASK) {

• virtio_transport_reset_no_sock(t, skb);
  

• virtio_transport_reset_no_sock(t, skb, sock_net(sk),
  

• 			       vsk->net_mode);
  

  return -ESHUTDOWN; }

  child = vsock_create_connected(sk); if (!child) {

• virtio_transport_reset_no_sock(t, skb);
  

• virtio_transport_reset_no_sock(t, skb, sock_net(sk),
  

• 			       vsk->net_mode);
  

  return -ENOMEM; }

@@ -1554,7 +1582,8 @@ virtio_transport_recv_listen(struct sock *sk, struct sk_buff *skb, */ if (ret || vchild->transport != &t->transport) { release_sock(child);

• virtio_transport_reset_no_sock(t, skb);
  

• virtio_transport_reset_no_sock(t, skb, sock_net(sk),
  

• 			       vsk->net_mode);
  

  sock_put(child); return ret; }

@@ -1582,7 +1611,8 @@ static bool virtio_transport_valid_type(u16 type)

• lock.

*/ void virtio_transport_recv_pkt(struct virtio_transport *t,

• 	       struct sk_buff *skb)
  

• 	       struct sk_buff *skb, struct net *net,
  

• 	       enum vsock_net_mode net_mode)
  

{ struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb); struct sockaddr_vm src, dst; @@ -1605,24 +1635,25 @@ void virtio_transport_recv_pkt(struct virtio_transport *t, le32_to_cpu(hdr->fwd_cnt));

if (!virtio_transport_valid_type(le16_to_cpu(hdr->type))) {

• (void)virtio_transport_reset_no_sock(t, skb);
  

• (void)virtio_transport_reset_no_sock(t, skb, net, net_mode);
  

  goto free_pkt; }

  /* 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_net(&src, &dst, net, net_mode); if (!sk) {

• sk = vsock_find_bound_socket(&dst);
  

• sk = vsock_find_bound_socket_net(&dst, net, net_mode);
  

  if (!sk) {

• 	(void)virtio_transport_reset_no_sock(t, skb);
  

• 	(void)virtio_transport_reset_no_sock(t, skb, net,
  

• 					     net_mode);
  goto free_pkt;
  

  } }

  if (virtio_transport_get_type(sk) != le16_to_cpu(hdr->type)) {

• (void)virtio_transport_reset_no_sock(t, skb);
  

• (void)virtio_transport_reset_no_sock(t, skb, net, net_mode);
  

  sock_put(sk); goto free_pkt; }

@@ -1641,7 +1672,7 @@ void virtio_transport_recv_pkt(struct virtio_transport *t, */ if (sock_flag(sk, SOCK_DONE) || (sk->sk_state != TCP_LISTEN && vsk->transport != &t->transport)) {

• (void)virtio_transport_reset_no_sock(t, skb);
  

• (void)virtio_transport_reset_no_sock(t, skb, net, net_mode);
  

  release_sock(sk); sock_put(sk); goto free_pkt;

@@ -1673,7 +1704,7 @@ void virtio_transport_recv_pkt(struct virtio_transport *t, kfree_skb(skb); break; default:

• (void)virtio_transport_reset_no_sock(t, skb);
  

• (void)virtio_transport_reset_no_sock(t, skb, net, net_mode);
  

  kfree_skb(skb); break; }

diff --git a/net/vmw_vsock/vsock_loopback.c b/net/vmw_vsock/vsock_loopback.c index afad27cf533a..aef44d1631c3 100644 --- a/net/vmw_vsock/vsock_loopback.c +++ b/net/vmw_vsock/vsock_loopback.c @@ -26,7 +26,8 @@ static u32 vsock_loopback_get_local_cid(void) return VMADDR_CID_LOCAL; }

-static int vsock_loopback_send_pkt(struct sk_buff *skb) +static int vsock_loopback_send_pkt(struct sk_buff *skb, struct net *net,

• 		   enum vsock_net_mode net_mode)
  

{ struct vsock_loopback *vsock = &the_vsock_loopback; int len = skb->len; @@ -48,6 +49,13 @@ static int vsock_loopback_cancel_pkt(struct vsock_sock *vsk)

static bool vsock_loopback_seqpacket_allow(struct vsock_sock *vsk, u32 remote_cid);

+static bool vsock_loopback_stream_allow(struct vsock_sock *vsk, u32 cid,

• 			u32 port)
  

+{

• return true;

+}

static bool vsock_loopback_msgzerocopy_allow(void) { return true; @@ -77,7 +85,7 @@ static struct virtio_transport loopback_transport = { .stream_has_space = virtio_transport_stream_has_space, .stream_rcvhiwat = virtio_transport_stream_rcvhiwat, .stream_is_active = virtio_transport_stream_is_active,

• .stream_allow             = virtio_transport_stream_allow,
  

• .stream_allow             = vsock_loopback_stream_allow,
  

So after this change, there is only virtio_transport.c using the virtio_transport_stream_allow() defined in virtio_transport_common.c right?

At that point, we should move it in virtio_transport.c IMO.

That said, we can do it with a follow-up patch, since the behaviour is unchanged, so:

Reviewed-by: Stefano Garzarella sgarzare@redhat.com

.seqpacket_dequeue        = virtio_transport_seqpacket_dequeue,
.seqpacket_enqueue        = virtio_transport_seqpacket_enqueue,

@@ -110,7 +118,7 @@ static struct virtio_transport loopback_transport = { static bool vsock_loopback_seqpacket_allow(struct vsock_sock *vsk, u32 remote_cid) {

• return vsk->net_mode == VSOCK_NET_MODE_GLOBAL;

• return true;

}

static void vsock_loopback_work(struct work_struct *work) @@ -132,7 +140,10 @@ static void vsock_loopback_work(struct work_struct *work) */ virtio_transport_consume_skb_sent(skb, false); virtio_transport_deliver_tap_pkt(skb);

• virtio_transport_recv_pkt(&loopback_transport, skb);
  

• virtio_transport_recv_pkt(&loopback_transport, skb,
  

• 			  sock_net(skb->sk),
  

• 			  vsock_sk(skb->sk)->net_mode);
  

  }

}

-- 2.47.3

On Tue, Dec 02, 2025 at 11:18:14AM +0100, Paolo Abeni wrote:

On 11/27/25 8:47 AM, Bobby Eshleman wrote:

...

@@ -674,6 +689,17 @@ 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);
• /* Store the mode of the namespace at the time of creation. If this

• * namespace later changes from "global" to "local", we want this vsock
  

• * to continue operating normally and not suddenly break. For that
  

• * reason, we save the mode here and later use it when performing
  

• * socket lookups with vsock_net_check_mode() (see vhost_vsock_get()).
  

• */
  

• vsock->net_mode = vsock_net_mode(net);

I'm sorry for the very late feedback. I think that at very least the user-space needs a way to query if the given transport is in local or global mode, as AFAICS there is no way to tell that when socket creation races with mode change.

Are you thinking something along the lines of sockopt?

Also I'm a bit uneasy with the model implemented here, as 'local' socket may cross netns boundaris and connect to 'local' socket in other netns (if I read correctly patch 2/12). That in turns AFAICS break the netns isolation.

Local mode sockets are unable to communicate with local mode (and global mode too) sockets that are in other namespaces. The key piece of code for that is vsock_net_check_mode(), where if either modes is local the namespaces must be the same.

Have you considered instead a slightly different model, where the local/global model is set in stone at netns creation time - alike what /proc/sys/net/ipv4/tcp_child_ehash_entries is doing[1] - and inter-netns connectivity is explicitly granted by the admin (I guess you will need new transport operations for that)?

/P

[1] tcp allows using per-netns established socket lookup tables - as opposed to the default global lookup table (even if match always takes in account the netns obviously). The mentioned sysctl specify such configuration for the children namespaces, if any.

I'll save this discussion if the above doesn't resolve your concerns.

Best, Bobby

On 12/2/25 6:56 PM, Bobby Eshleman wrote:

On Tue, Dec 02, 2025 at 11:18:14AM +0100, Paolo Abeni wrote:

...

On 11/27/25 8:47 AM, Bobby Eshleman wrote:

...

@@ -674,6 +689,17 @@ 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);
• /* Store the mode of the namespace at the time of creation. If this

• * namespace later changes from "global" to "local", we want this vsock
  

• * to continue operating normally and not suddenly break. For that
  

• * reason, we save the mode here and later use it when performing
  

• * socket lookups with vsock_net_check_mode() (see vhost_vsock_get()).
  

• */
  

• vsock->net_mode = vsock_net_mode(net);

I'm sorry for the very late feedback. I think that at very least the user-space needs a way to query if the given transport is in local or global mode, as AFAICS there is no way to tell that when socket creation races with mode change.

Are you thinking something along the lines of sockopt?

I'd like to see a way for the user-space to query the socket 'namespace mode'.

sockopt could be an option; a possibly better one could be sock_diag. Or you could do both using dumping the info with a shared helper invoked by both code paths, alike what TCP is doing.

...

Also I'm a bit uneasy with the model implemented here, as 'local' socket may cross netns boundaris and connect to 'local' socket in other netns (if I read correctly patch 2/12). That in turns AFAICS break the netns isolation.

Local mode sockets are unable to communicate with local mode (and global mode too) sockets that are in other namespaces. The key piece of code for that is vsock_net_check_mode(), where if either modes is local the namespaces must be the same.

Sorry, I likely misread the large comment in patch 2:

https://lore.kernel.org/netdev/20251126-vsock-vmtest-v12-2-257ee21cd5de@meta...

...

Have you considered instead a slightly different model, where the local/global model is set in stone at netns creation time - alike what /proc/sys/net/ipv4/tcp_child_ehash_entries is doing[1] - and inter-netns connectivity is explicitly granted by the admin (I guess you will need new transport operations for that)?

/P

[1] tcp allows using per-netns established socket lookup tables - as opposed to the default global lookup table (even if match always takes in account the netns obviously). The mentioned sysctl specify such configuration for the children namespaces, if any.

I'll save this discussion if the above doesn't resolve your concerns.

I still have some concern WRT the dynamic mode change after netns creation. I fear some 'unsolvable' (or very hard to solve) race I can't see now. A tcp_child_ehash_entries-like model will avoid completely the issue, but I understand it would be a significant change over the current status.

"Luckily" the merge window is on us and we have some time to discuss. Do you have a specific use-case for the ability to change the netns mode after creation?

/P

On Tue, 2 Dec 2025 at 23:01, Bobby Eshleman bobbyeshleman@gmail.com wrote:

On Tue, Dec 02, 2025 at 09:47:19PM +0100, Paolo Abeni wrote:

...

On 12/2/25 6:56 PM, Bobby Eshleman wrote:

...

On Tue, Dec 02, 2025 at 11:18:14AM +0100, Paolo Abeni wrote:

...

On 11/27/25 8:47 AM, Bobby Eshleman wrote:

...

@@ -674,6 +689,17 @@ 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);
• /* Store the mode of the namespace at the time of creation. If this
• • namespace later changes from "global" to "local", we want this vsock
• • to continue operating normally and not suddenly break. For that
• • reason, we save the mode here and later use it when performing
• • socket lookups with vsock_net_check_mode() (see vhost_vsock_get()).
• */
• vsock->net_mode = vsock_net_mode(net);

I'm sorry for the very late feedback. I think that at very least the user-space needs a way to query if the given transport is in local or global mode, as AFAICS there is no way to tell that when socket creation races with mode change.

Are you thinking something along the lines of sockopt?

I'd like to see a way for the user-space to query the socket 'namespace mode'.

sockopt could be an option; a possibly better one could be sock_diag. Or you could do both using dumping the info with a shared helper invoked by both code paths, alike what TCP is doing.

...

...

Also I'm a bit uneasy with the model implemented here, as 'local' socket may cross netns boundaris and connect to 'local' socket in other netns (if I read correctly patch 2/12). That in turns AFAICS break the netns isolation.

Local mode sockets are unable to communicate with local mode (and global mode too) sockets that are in other namespaces. The key piece of code for that is vsock_net_check_mode(), where if either modes is local the namespaces must be the same.

Sorry, I likely misread the large comment in patch 2:

https://lore.kernel.org/netdev/20251126-vsock-vmtest-v12-2-257ee21cd5de@meta...

...

...

Have you considered instead a slightly different model, where the local/global model is set in stone at netns creation time - alike what /proc/sys/net/ipv4/tcp_child_ehash_entries is doing[1] - and inter-netns connectivity is explicitly granted by the admin (I guess you will need new transport operations for that)?

/P

[1] tcp allows using per-netns established socket lookup tables - as opposed to the default global lookup table (even if match always takes in account the netns obviously). The mentioned sysctl specify such configuration for the children namespaces, if any.

I'll save this discussion if the above doesn't resolve your concerns.

I still have some concern WRT the dynamic mode change after netns creation. I fear some 'unsolvable' (or very hard to solve) race I can't see now. A tcp_child_ehash_entries-like model will avoid completely the issue, but I understand it would be a significant change over the current status.

"Luckily" the merge window is on us and we have some time to discuss. Do you have a specific use-case for the ability to change the netns mode after creation?

/P

I don't think there is a hard requirement that the mode be change-able after creation. Though I'd love to avoid such a big change... or at least leave unchanged as much of what we've already reviewed as possible.

I think the big part is done, IIUC this should just be a change to the uAPI and maybe simplify what we have a little (e.g., avoid saving the mode each socket had when it was created).

In the scheme of defining the mode at creation and following the tcp_child_ehash_entries-ish model, what I'm imagining is:

• /proc/sys/net/vsock/child_ns_mode can be set to "local" or "global"

• /proc/sys/net/vsock/child_ns_mode is not immutable, can change any number of times

• when a netns is created, the new netns mode is inherited from child_ns_mode, being assigned using something like:

      net->vsock.ns_mode =
            get_net_ns_by_pid(current->pid)->child_ns_mode
  
  

• /proc/sys/net/vsock/ns_mode queries the current mode, returning "local" or "global", returning value of net->vsock.ns_mode

• /proc/sys/net/vsock/ns_mode and net->vsock.ns_mode are immutable and reject writes

Does that align with what you have in mind?

Stefano, what are your thoughts?

If we can avoid having sockets in a namespace that can be both global and local, perhaps it makes a lot of sense to make this change.

My only concern is that there is still a small window where the mode can change, but we are sure that only one is picked during creation and then within the namespace this can be easily checked and give us the assurance that all sockets comply with it, right?

Thanks, Stefano

On Tue, Dec 02, 2025 at 02:01:04PM -0800, Bobby Eshleman wrote:

On Tue, Dec 02, 2025 at 09:47:19PM +0100, Paolo Abeni wrote:

...

On 12/2/25 6:56 PM, Bobby Eshleman wrote:

...

On Tue, Dec 02, 2025 at 11:18:14AM +0100, Paolo Abeni wrote:

...

On 11/27/25 8:47 AM, Bobby Eshleman wrote:

...

@@ -674,6 +689,17 @@ 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);
• /* Store the mode of the namespace at the time of creation. If this

• * namespace later changes from "global" to "local", we want this vsock
  

• * to continue operating normally and not suddenly break. For that
  

• * reason, we save the mode here and later use it when performing
  

• * socket lookups with vsock_net_check_mode() (see vhost_vsock_get()).
  

• */
  

• vsock->net_mode = vsock_net_mode(net);

I'm sorry for the very late feedback. I think that at very least the user-space needs a way to query if the given transport is in local or global mode, as AFAICS there is no way to tell that when socket creation races with mode change.

Are you thinking something along the lines of sockopt?

I'd like to see a way for the user-space to query the socket 'namespace mode'.

sockopt could be an option; a possibly better one could be sock_diag. Or you could do both using dumping the info with a shared helper invoked by both code paths, alike what TCP is doing.

...

...

Also I'm a bit uneasy with the model implemented here, as 'local' socket may cross netns boundaris and connect to 'local' socket in other netns (if I read correctly patch 2/12). That in turns AFAICS break the netns isolation.

Local mode sockets are unable to communicate with local mode (and global mode too) sockets that are in other namespaces. The key piece of code for that is vsock_net_check_mode(), where if either modes is local the namespaces must be the same.

Sorry, I likely misread the large comment in patch 2:

https://lore.kernel.org/netdev/20251126-vsock-vmtest-v12-2-257ee21cd5de@meta...

...

...

Have you considered instead a slightly different model, where the local/global model is set in stone at netns creation time - alike what /proc/sys/net/ipv4/tcp_child_ehash_entries is doing[1] - and inter-netns connectivity is explicitly granted by the admin (I guess you will need new transport operations for that)?

/P

[1] tcp allows using per-netns established socket lookup tables - as opposed to the default global lookup table (even if match always takes in account the netns obviously). The mentioned sysctl specify such configuration for the children namespaces, if any.

I'll save this discussion if the above doesn't resolve your concerns.

I still have some concern WRT the dynamic mode change after netns creation. I fear some 'unsolvable' (or very hard to solve) race I can't see now. A tcp_child_ehash_entries-like model will avoid completely the issue, but I understand it would be a significant change over the current status.

"Luckily" the merge window is on us and we have some time to discuss. Do you have a specific use-case for the ability to change the netns mode after creation?

/P

I don't think there is a hard requirement that the mode be change-able after creation. Though I'd love to avoid such a big change... or at least leave unchanged as much of what we've already reviewed as possible.

In the scheme of defining the mode at creation and following the tcp_child_ehash_entries-ish model, what I'm imagining is:

• /proc/sys/net/vsock/child_ns_mode can be set to "local" or "global"

• /proc/sys/net/vsock/child_ns_mode is not immutable, can change any number of times

• when a netns is created, the new netns mode is inherited from child_ns_mode, being assigned using something like:

  net->vsock.ns_mode = get_net_ns_by_pid(current->pid)->child_ns_mode

• /proc/sys/net/vsock/ns_mode queries the current mode, returning "local" or "global", returning value of net->vsock.ns_mode

• /proc/sys/net/vsock/ns_mode and net->vsock.ns_mode are immutable and reject writes

Does that align with what you have in mind?

Hey Paolo, I just wanted to sync up on this one. Does the above align with what you envision?

Best, Bobby

On Mon, Dec 15, 2025 at 03:11:22PM +0100, Stefano Garzarella wrote:

On Fri, Dec 12, 2025 at 07:26:15AM -0800, Bobby Eshleman wrote:

...

On Tue, Dec 02, 2025 at 02:01:04PM -0800, Bobby Eshleman wrote:

...

On Tue, Dec 02, 2025 at 09:47:19PM +0100, Paolo Abeni wrote:

...

On 12/2/25 6:56 PM, Bobby Eshleman wrote:

...

On Tue, Dec 02, 2025 at 11:18:14AM +0100, Paolo Abeni wrote:

...

On 11/27/25 8:47 AM, Bobby Eshleman wrote: > @@ -674,6 +689,17 @@ 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); > + > + /* Store the mode of the namespace at the time of creation. If this > + * namespace later changes from "global" to "local", we want this vsock > + * to continue operating normally and not suddenly break. For that > + * reason, we save the mode here and later use it when performing > + * socket lookups with vsock_net_check_mode() (see vhost_vsock_get()). > + */ > + vsock->net_mode = vsock_net_mode(net);

I'm sorry for the very late feedback. I think that at very least the user-space needs a way to query if the given transport is in local or global mode, as AFAICS there is no way to tell that when socket creation races with mode change.

Are you thinking something along the lines of sockopt?

I'd like to see a way for the user-space to query the socket 'namespace mode'.

sockopt could be an option; a possibly better one could be sock_diag. Or you could do both using dumping the info with a shared helper invoked by both code paths, alike what TCP is doing.

...

...

Also I'm a bit uneasy with the model implemented here, as 'local' socket may cross netns boundaris and connect to 'local' socket in other netns (if I read correctly patch 2/12). That in turns AFAICS break the netns isolation.

Local mode sockets are unable to communicate with local mode (and global mode too) sockets that are in other namespaces. The key piece of code for that is vsock_net_check_mode(), where if either modes is local the namespaces must be the same.

Sorry, I likely misread the large comment in patch 2:

https://lore.kernel.org/netdev/20251126-vsock-vmtest-v12-2-257ee21cd5de@meta...

...

...

Have you considered instead a slightly different model, where the local/global model is set in stone at netns creation time - alike what /proc/sys/net/ipv4/tcp_child_ehash_entries is doing[1] - and inter-netns connectivity is explicitly granted by the admin (I guess you will need new transport operations for that)?

/P

[1] tcp allows using per-netns established socket lookup tables - as opposed to the default global lookup table (even if match always takes in account the netns obviously). The mentioned sysctl specify such configuration for the children namespaces, if any.

I'll save this discussion if the above doesn't resolve your concerns.

I still have some concern WRT the dynamic mode change after netns creation. I fear some 'unsolvable' (or very hard to solve) race I can't see now. A tcp_child_ehash_entries-like model will avoid completely the issue, but I understand it would be a significant change over the current status.

"Luckily" the merge window is on us and we have some time to discuss. Do you have a specific use-case for the ability to change the netns >

mode

...

after creation?

/P

I don't think there is a hard requirement that the mode be change-able after creation. Though I'd love to avoid such a big change... or at least leave unchanged as much of what we've already reviewed as possible.

In the scheme of defining the mode at creation and following the tcp_child_ehash_entries-ish model, what I'm imagining is:

• /proc/sys/net/vsock/child_ns_mode can be set to "local" or "global"

• /proc/sys/net/vsock/child_ns_mode is not immutable, can change any number of times

• when a netns is created, the new netns mode is inherited from child_ns_mode, being assigned using something like:

  net->vsock.ns_mode = get_net_ns_by_pid(current->pid)->child_ns_mode

• /proc/sys/net/vsock/ns_mode queries the current mode, returning "local" or "global", returning value of net->vsock.ns_mode

• /proc/sys/net/vsock/ns_mode and net->vsock.ns_mode are immutable and reject writes

Does that align with what you have in mind?

Hey Paolo, I just wanted to sync up on this one. Does the above align with what you envision?

Hi Bobby, AFAIK Paolo was at LPC, so there could be some delay.

FYI I'll be off from Dec 25 to Jan 6, so if we want to do an RFC in the middle, I'll do my best to take a look before my time off.

Thanks, Stefano

Sounds like a plan, thanks!

Best, Bobby