[RFC PATCH net-next v6 01/14] af_vsock: generalize vsock_dgram_recvmsg() to all transports
From: Amery Hung <hidden>
Date: 2024-07-10 21:25:57
Also in:
bpf, kvm, linux-hyperv, lkml, virtualization
Subsystem:
hyper-v/azure core and drivers, networking [general], the rest, virtio and vhost vsock driver, virtio core, virtio host (vhost), vm sockets (af_vsock), vmware vsock vmci transport driver · Maintainers:
"K. Y. Srinivasan", Haiyang Zhang, Wei Liu, Dexuan Cui, Long Li, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Stefan Hajnoczi, Stefano Garzarella, "Michael S. Tsirkin", Jason Wang, Bryan Tan, Vishnu Dasa
From: Bobby Eshleman <redacted> This commit drops the transport->dgram_dequeue callback and makes vsock_dgram_recvmsg() generic to all transports. To make this possible, two transport-level changes are introduced: - transport in the receiving path now stores the cid and port into the control buffer of an skb when populating an skb. The information later is used to initialize sockaddr_vm structure in recvmsg() without referencing vsk->transport. - transport implementations set the skb->data pointer to the beginning of the payload prior to adding the skb to the socket's receive queue. That is, they must use skb_pull() before enqueuing. This is an agreement between the transport and the socket layer that skb->data always points to the beginning of the payload (and not, for example, the packet header). Signed-off-by: Bobby Eshleman <redacted> Signed-off-by: Amery Hung <redacted> --- drivers/vhost/vsock.c | 1 - include/linux/virtio_vsock.h | 5 --- include/net/af_vsock.h | 11 ++++- net/vmw_vsock/af_vsock.c | 42 +++++++++++++++++- net/vmw_vsock/hyperv_transport.c | 7 --- net/vmw_vsock/virtio_transport.c | 1 - net/vmw_vsock/virtio_transport_common.c | 9 ---- net/vmw_vsock/vmci_transport.c | 59 +++---------------------- net/vmw_vsock/vsock_loopback.c | 1 - 9 files changed, 55 insertions(+), 81 deletions(-)
diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
index ec20ecff85c7..97fffa914e66 100644
--- a/drivers/vhost/vsock.c
+++ b/drivers/vhost/vsock.c@@ -419,7 +419,6 @@ static struct virtio_transport vhost_transport = { .cancel_pkt = vhost_transport_cancel_pkt, .dgram_enqueue = virtio_transport_dgram_enqueue, - .dgram_dequeue = virtio_transport_dgram_dequeue, .dgram_bind = virtio_transport_dgram_bind, .dgram_allow = virtio_transport_dgram_allow,
diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h
index c82089dee0c8..8b56b8a19ddd 100644
--- a/include/linux/virtio_vsock.h
+++ b/include/linux/virtio_vsock.h@@ -177,11 +177,6 @@ virtio_transport_stream_dequeue(struct vsock_sock *vsk, size_t len, int type); int -virtio_transport_dgram_dequeue(struct vsock_sock *vsk, - struct msghdr *msg, - size_t len, int flags); - -int virtio_transport_seqpacket_enqueue(struct vsock_sock *vsk, struct msghdr *msg, size_t len);
diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h
index 535701efc1e5..7aa1f5f2b1a5 100644
--- a/include/net/af_vsock.h
+++ b/include/net/af_vsock.h@@ -120,8 +120,6 @@ struct vsock_transport { /* DGRAM. */ int (*dgram_bind)(struct vsock_sock *, struct sockaddr_vm *); - int (*dgram_dequeue)(struct vsock_sock *vsk, struct msghdr *msg, - 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);
@@ -219,6 +217,15 @@ void vsock_for_each_connected_socket(struct vsock_transport *transport, int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk); bool vsock_find_cid(unsigned int cid); +struct vsock_skb_cb { + unsigned int src_cid; + unsigned int src_port; +}; + +static inline struct vsock_skb_cb *vsock_skb_cb(struct sk_buff *skb) { + return (struct vsock_skb_cb *)skb->cb; +}; + /**** TAP ****/ struct vsock_tap {
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index 4b040285aa78..5e7d4d99ea2c 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c@@ -1273,11 +1273,15 @@ static int vsock_dgram_connect(struct socket *sock, int vsock_dgram_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, int flags) { + struct vsock_skb_cb *vsock_cb; #ifdef CONFIG_BPF_SYSCALL const struct proto *prot; #endif struct vsock_sock *vsk; + struct sk_buff *skb; + size_t payload_len; struct sock *sk; + int err; sk = sock->sk; vsk = vsock_sk(sk);
@@ -1288,7 +1292,43 @@ int vsock_dgram_recvmsg(struct socket *sock, struct msghdr *msg, return prot->recvmsg(sk, msg, len, flags, NULL); #endif - return vsk->transport->dgram_dequeue(vsk, msg, len, flags); + if (flags & MSG_OOB || flags & MSG_ERRQUEUE) + return -EOPNOTSUPP; + + if (unlikely(flags & MSG_ERRQUEUE)) + return sock_recv_errqueue(sk, msg, len, SOL_VSOCK, 0); + + /* Retrieve the head sk_buff from the socket's receive queue. */ + err = 0; + skb = skb_recv_datagram(sk_vsock(vsk), flags, &err); + if (!skb) + return err; + + payload_len = skb->len; + + if (payload_len > len) { + payload_len = len; + msg->msg_flags |= MSG_TRUNC; + } + + /* Place the datagram payload in the user's iovec. */ + err = skb_copy_datagram_msg(skb, 0, msg, payload_len); + if (err) + goto out; + + if (msg->msg_name) { + /* Provide the address of the sender. */ + DECLARE_SOCKADDR(struct sockaddr_vm *, vm_addr, msg->msg_name); + + vsock_cb = vsock_skb_cb(skb); + vsock_addr_init(vm_addr, vsock_cb->src_cid, vsock_cb->src_port); + msg->msg_namelen = sizeof(*vm_addr); + } + err = payload_len; + +out: + skb_free_datagram(&vsk->sk, skb); + return err; } EXPORT_SYMBOL_GPL(vsock_dgram_recvmsg);
diff --git a/net/vmw_vsock/hyperv_transport.c b/net/vmw_vsock/hyperv_transport.c
index e2157e387217..326dd41ee2d5 100644
--- a/net/vmw_vsock/hyperv_transport.c
+++ b/net/vmw_vsock/hyperv_transport.c@@ -556,12 +556,6 @@ static int hvs_dgram_bind(struct vsock_sock *vsk, struct sockaddr_vm *addr) return -EOPNOTSUPP; } -static int hvs_dgram_dequeue(struct vsock_sock *vsk, struct msghdr *msg, - size_t len, int flags) -{ - return -EOPNOTSUPP; -} - static int hvs_dgram_enqueue(struct vsock_sock *vsk, struct sockaddr_vm *remote, struct msghdr *msg, size_t dgram_len)
@@ -833,7 +827,6 @@ static struct vsock_transport hvs_transport = { .shutdown = hvs_shutdown, .dgram_bind = hvs_dgram_bind, - .dgram_dequeue = hvs_dgram_dequeue, .dgram_enqueue = hvs_dgram_enqueue, .dgram_allow = hvs_dgram_allow,
diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
index 43d405298857..a8c97e95622a 100644
--- a/net/vmw_vsock/virtio_transport.c
+++ b/net/vmw_vsock/virtio_transport.c@@ -508,7 +508,6 @@ static struct virtio_transport virtio_transport = { .cancel_pkt = virtio_transport_cancel_pkt, .dgram_bind = virtio_transport_dgram_bind, - .dgram_dequeue = virtio_transport_dgram_dequeue, .dgram_enqueue = virtio_transport_dgram_enqueue, .dgram_allow = virtio_transport_dgram_allow,
diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
index 16ff976a86e3..4bf73d20c12a 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c@@ -810,15 +810,6 @@ virtio_transport_seqpacket_enqueue(struct vsock_sock *vsk, } EXPORT_SYMBOL_GPL(virtio_transport_seqpacket_enqueue); -int -virtio_transport_dgram_dequeue(struct vsock_sock *vsk, - struct msghdr *msg, - size_t len, int flags) -{ - return -EOPNOTSUPP; -} -EXPORT_SYMBOL_GPL(virtio_transport_dgram_dequeue); - s64 virtio_transport_stream_has_data(struct vsock_sock *vsk) { struct virtio_vsock_sock *vvs = vsk->trans;
diff --git a/net/vmw_vsock/vmci_transport.c b/net/vmw_vsock/vmci_transport.c
index b370070194fa..b39df3ed8c8d 100644
--- a/net/vmw_vsock/vmci_transport.c
+++ b/net/vmw_vsock/vmci_transport.c@@ -610,6 +610,7 @@ vmci_transport_datagram_create_hnd(u32 resource_id, static int vmci_transport_recv_dgram_cb(void *data, struct vmci_datagram *dg) { + struct vsock_skb_cb *vsock_cb; struct sock *sk; size_t size; struct sk_buff *skb;
@@ -637,10 +638,14 @@ static int vmci_transport_recv_dgram_cb(void *data, struct vmci_datagram *dg) if (!skb) return VMCI_ERROR_NO_MEM; + vsock_cb = vsock_skb_cb(skb); + vsock_cb->src_cid = dg->src.context; + vsock_cb->src_port = dg->src.resource; /* sk_receive_skb() will do a sock_put(), so hold here. */ sock_hold(sk); skb_put(skb, size); memcpy(skb->data, dg, size); + skb_pull(skb, VMCI_DG_HEADERSIZE); sk_receive_skb(sk, skb, 0); return VMCI_SUCCESS;
@@ -1731,59 +1736,6 @@ static int vmci_transport_dgram_enqueue( return err - sizeof(*dg); } -static int vmci_transport_dgram_dequeue(struct vsock_sock *vsk, - struct msghdr *msg, size_t len, - int flags) -{ - int err; - struct vmci_datagram *dg; - size_t payload_len; - struct sk_buff *skb; - - if (flags & MSG_OOB || flags & MSG_ERRQUEUE) - return -EOPNOTSUPP; - - /* Retrieve the head sk_buff from the socket's receive queue. */ - err = 0; - skb = skb_recv_datagram(&vsk->sk, flags, &err); - if (!skb) - return err; - - dg = (struct vmci_datagram *)skb->data; - if (!dg) - /* err is 0, meaning we read zero bytes. */ - goto out; - - payload_len = dg->payload_size; - /* Ensure the sk_buff matches the payload size claimed in the packet. */ - if (payload_len != skb->len - sizeof(*dg)) { - err = -EINVAL; - goto out; - } - - if (payload_len > len) { - payload_len = len; - msg->msg_flags |= MSG_TRUNC; - } - - /* Place the datagram payload in the user's iovec. */ - err = skb_copy_datagram_msg(skb, sizeof(*dg), msg, payload_len); - if (err) - goto out; - - if (msg->msg_name) { - /* Provide the address of the sender. */ - DECLARE_SOCKADDR(struct sockaddr_vm *, vm_addr, msg->msg_name); - vsock_addr_init(vm_addr, dg->src.context, dg->src.resource); - msg->msg_namelen = sizeof(*vm_addr); - } - err = payload_len; - -out: - skb_free_datagram(&vsk->sk, skb); - return err; -} - static bool vmci_transport_dgram_allow(u32 cid, u32 port) { if (cid == VMADDR_CID_HYPERVISOR) {
@@ -2040,7 +1992,6 @@ static struct vsock_transport vmci_transport = { .release = vmci_transport_release, .connect = vmci_transport_connect, .dgram_bind = vmci_transport_dgram_bind, - .dgram_dequeue = vmci_transport_dgram_dequeue, .dgram_enqueue = vmci_transport_dgram_enqueue, .dgram_allow = vmci_transport_dgram_allow, .stream_dequeue = vmci_transport_stream_dequeue,
diff --git a/net/vmw_vsock/vsock_loopback.c b/net/vmw_vsock/vsock_loopback.c
index 6dea6119f5b2..11488887a5cc 100644
--- a/net/vmw_vsock/vsock_loopback.c
+++ b/net/vmw_vsock/vsock_loopback.c@@ -66,7 +66,6 @@ static struct virtio_transport loopback_transport = { .cancel_pkt = vsock_loopback_cancel_pkt, .dgram_bind = virtio_transport_dgram_bind, - .dgram_dequeue = virtio_transport_dgram_dequeue, .dgram_enqueue = virtio_transport_dgram_enqueue, .dgram_allow = virtio_transport_dgram_allow,
--
2.20.1