This patch adds sockmap support for vsock sockets. It is intended to be usable by all transports, but only the virtio transport is implemented.
Signed-off-by: Bobby Eshleman bobby.eshleman@bytedance.com --- drivers/vhost/vsock.c | 1 + include/linux/virtio_vsock.h | 1 + include/net/af_vsock.h | 17 ++++ net/vmw_vsock/Makefile | 1 + net/vmw_vsock/af_vsock.c | 55 ++++++++-- net/vmw_vsock/virtio_transport.c | 2 + net/vmw_vsock/virtio_transport_common.c | 25 +++++ net/vmw_vsock/vsock_bpf.c | 174 ++++++++++++++++++++++++++++++++ net/vmw_vsock/vsock_loopback.c | 2 + 9 files changed, 272 insertions(+), 6 deletions(-)
diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c index 1f3b89c885cc..3c6dc036b904 100644 --- a/drivers/vhost/vsock.c +++ b/drivers/vhost/vsock.c @@ -439,6 +439,7 @@ static struct virtio_transport vhost_transport = { .notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue, .notify_buffer_size = virtio_transport_notify_buffer_size,
+ .read_skb = virtio_transport_read_skb, },
.send_pkt = vhost_transport_send_pkt, diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h index 3f9c16611306..c58453699ee9 100644 --- a/include/linux/virtio_vsock.h +++ b/include/linux/virtio_vsock.h @@ -245,4 +245,5 @@ u32 virtio_transport_get_credit(struct virtio_vsock_sock *vvs, u32 wanted); void virtio_transport_put_credit(struct virtio_vsock_sock *vvs, u32 credit); void virtio_transport_deliver_tap_pkt(struct sk_buff *skb); int virtio_transport_purge_skbs(void *vsk, struct sk_buff_head *list); +int virtio_transport_read_skb(struct vsock_sock *vsk, skb_read_actor_t read_actor); #endif /* _LINUX_VIRTIO_VSOCK_H */ diff --git a/include/net/af_vsock.h b/include/net/af_vsock.h index 568a87c5e0d0..a73f5fbd296a 100644 --- a/include/net/af_vsock.h +++ b/include/net/af_vsock.h @@ -75,6 +75,7 @@ struct vsock_sock { void *trans; };
+s64 vsock_connectible_has_data(struct vsock_sock *vsk); s64 vsock_stream_has_data(struct vsock_sock *vsk); s64 vsock_stream_has_space(struct vsock_sock *vsk); struct sock *vsock_create_connected(struct sock *parent); @@ -173,6 +174,9 @@ struct vsock_transport {
/* Addressing. */ u32 (*get_local_cid)(void); + + /* Read a single skb */ + int (*read_skb)(struct vsock_sock *, skb_read_actor_t); };
/**** CORE ****/ @@ -225,5 +229,18 @@ int vsock_init_tap(void); int vsock_add_tap(struct vsock_tap *vt); int vsock_remove_tap(struct vsock_tap *vt); void vsock_deliver_tap(struct sk_buff *build_skb(void *opaque), void *opaque); +int vsock_connectible_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, + int flags); +int vsock_dgram_recvmsg(struct socket *sock, struct msghdr *msg, + size_t len, int flags); + +#ifdef CONFIG_BPF_SYSCALL +extern struct proto vsock_proto; +int vsock_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore); +void __init vsock_bpf_build_proto(void); +#else +static inline void __init vsock_bpf_build_proto(void) +{} +#endif
#endif /* __AF_VSOCK_H__ */ diff --git a/net/vmw_vsock/Makefile b/net/vmw_vsock/Makefile index 6a943ec95c4a..5da74c4a9f1d 100644 --- a/net/vmw_vsock/Makefile +++ b/net/vmw_vsock/Makefile @@ -8,6 +8,7 @@ obj-$(CONFIG_HYPERV_VSOCKETS) += hv_sock.o obj-$(CONFIG_VSOCKETS_LOOPBACK) += vsock_loopback.o
vsock-y += af_vsock.o af_vsock_tap.o vsock_addr.o +vsock-$(CONFIG_BPF_SYSCALL) += vsock_bpf.o
vsock_diag-y += diag.o
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c index 19aea7cba26e..f2cc04fb8b13 100644 --- a/net/vmw_vsock/af_vsock.c +++ b/net/vmw_vsock/af_vsock.c @@ -116,10 +116,13 @@ static void vsock_sk_destruct(struct sock *sk); static int vsock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
/* Protocol family. */ -static struct proto vsock_proto = { +struct proto vsock_proto = { .name = "AF_VSOCK", .owner = THIS_MODULE, .obj_size = sizeof(struct vsock_sock), +#ifdef CONFIG_BPF_SYSCALL + .psock_update_sk_prot = vsock_bpf_update_proto, +#endif };
/* The default peer timeout indicates how long we will wait for a peer response @@ -865,7 +868,7 @@ s64 vsock_stream_has_data(struct vsock_sock *vsk) } EXPORT_SYMBOL_GPL(vsock_stream_has_data);
-static s64 vsock_connectible_has_data(struct vsock_sock *vsk) +s64 vsock_connectible_has_data(struct vsock_sock *vsk) { struct sock *sk = sk_vsock(vsk);
@@ -874,6 +877,7 @@ static s64 vsock_connectible_has_data(struct vsock_sock *vsk) else return vsock_stream_has_data(vsk); } +EXPORT_SYMBOL_GPL(vsock_connectible_has_data);
s64 vsock_stream_has_space(struct vsock_sock *vsk) { @@ -1131,6 +1135,13 @@ static __poll_t vsock_poll(struct file *file, struct socket *sock, return mask; }
+static int vsock_read_skb(struct sock *sk, skb_read_actor_t read_actor) +{ + struct vsock_sock *vsk = vsock_sk(sk); + + return vsk->transport->read_skb(vsk, read_actor); +} + static int vsock_dgram_sendmsg(struct socket *sock, struct msghdr *msg, size_t len) { @@ -1241,19 +1252,34 @@ static int vsock_dgram_connect(struct socket *sock,
memcpy(&vsk->remote_addr, remote_addr, sizeof(vsk->remote_addr)); sock->state = SS_CONNECTED; + sk->sk_state = TCP_ESTABLISHED;
out: release_sock(sk); return err; }
-static int vsock_dgram_recvmsg(struct socket *sock, struct msghdr *msg, - size_t len, int flags) +int vsock_dgram_recvmsg(struct socket *sock, struct msghdr *msg, + size_t len, int flags) { - struct vsock_sock *vsk = vsock_sk(sock->sk); +#ifdef CONFIG_BPF_SYSCALL + const struct proto *prot; +#endif + struct vsock_sock *vsk; + struct sock *sk; + + sk = sock->sk; + vsk = vsock_sk(sk); + +#ifdef CONFIG_BPF_SYSCALL + prot = READ_ONCE(sk->sk_prot); + if (prot != &vsock_proto) + return prot->recvmsg(sk, msg, len, flags, NULL); +#endif
return vsk->transport->dgram_dequeue(vsk, msg, len, flags); } +EXPORT_SYMBOL_GPL(vsock_dgram_recvmsg);
static const struct proto_ops vsock_dgram_ops = { .family = PF_VSOCK, @@ -1272,6 +1298,7 @@ static const struct proto_ops vsock_dgram_ops = { .recvmsg = vsock_dgram_recvmsg, .mmap = sock_no_mmap, .sendpage = sock_no_sendpage, + .read_skb = vsock_read_skb, };
static int vsock_transport_cancel_pkt(struct vsock_sock *vsk) @@ -2086,13 +2113,16 @@ static int __vsock_seqpacket_recvmsg(struct sock *sk, struct msghdr *msg, return err; }
-static int +int vsock_connectible_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, int flags) { struct sock *sk; struct vsock_sock *vsk; const struct vsock_transport *transport; +#ifdef CONFIG_BPF_SYSCALL + const struct proto *prot; +#endif int err;
sk = sock->sk; @@ -2139,6 +2169,14 @@ vsock_connectible_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, goto out; }
+#ifdef CONFIG_BPF_SYSCALL + prot = READ_ONCE(sk->sk_prot); + if (prot != &vsock_proto) { + release_sock(sk); + return prot->recvmsg(sk, msg, len, flags, NULL); + } +#endif + if (sk->sk_type == SOCK_STREAM) err = __vsock_stream_recvmsg(sk, msg, len, flags); else @@ -2148,6 +2186,7 @@ vsock_connectible_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, release_sock(sk); return err; } +EXPORT_SYMBOL_GPL(vsock_connectible_recvmsg);
static int vsock_set_rcvlowat(struct sock *sk, int val) { @@ -2188,6 +2227,7 @@ static const struct proto_ops vsock_stream_ops = { .mmap = sock_no_mmap, .sendpage = sock_no_sendpage, .set_rcvlowat = vsock_set_rcvlowat, + .read_skb = vsock_read_skb, };
static const struct proto_ops vsock_seqpacket_ops = { @@ -2209,6 +2249,7 @@ static const struct proto_ops vsock_seqpacket_ops = { .recvmsg = vsock_connectible_recvmsg, .mmap = sock_no_mmap, .sendpage = sock_no_sendpage, + .read_skb = vsock_read_skb, };
static int vsock_create(struct net *net, struct socket *sock, @@ -2348,6 +2389,8 @@ static int __init vsock_init(void) goto err_unregister_proto; }
+ vsock_bpf_build_proto(); + return 0;
err_unregister_proto: diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c index 28b5a8e8e094..e95df847176b 100644 --- a/net/vmw_vsock/virtio_transport.c +++ b/net/vmw_vsock/virtio_transport.c @@ -457,6 +457,8 @@ static struct virtio_transport virtio_transport = { .notify_send_pre_enqueue = virtio_transport_notify_send_pre_enqueue, .notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue, .notify_buffer_size = virtio_transport_notify_buffer_size, + + .read_skb = virtio_transport_read_skb, },
.send_pkt = virtio_transport_send_pkt, diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c index a1581c77cf84..f64527f32385 100644 --- a/net/vmw_vsock/virtio_transport_common.c +++ b/net/vmw_vsock/virtio_transport_common.c @@ -1388,6 +1388,31 @@ int virtio_transport_purge_skbs(void *vsk, struct sk_buff_head *queue) } EXPORT_SYMBOL_GPL(virtio_transport_purge_skbs);
+int virtio_transport_read_skb(struct vsock_sock *vsk, skb_read_actor_t recv_actor) +{ + struct virtio_vsock_sock *vvs = vsk->trans; + struct sock *sk = sk_vsock(vsk); + struct sk_buff *skb; + int off = 0; + int copied; + int err; + + spin_lock_bh(&vvs->rx_lock); + /* Use __skb_recv_datagram() for race-free handling of the receive. It + * works for types other than dgrams. + */ + skb = __skb_recv_datagram(sk, &vvs->rx_queue, MSG_DONTWAIT, &off, &err); + spin_unlock_bh(&vvs->rx_lock); + + if (!skb) + return err; + + copied = recv_actor(sk, skb); + kfree_skb(skb); + return copied; +} +EXPORT_SYMBOL_GPL(virtio_transport_read_skb); + MODULE_LICENSE("GPL v2"); MODULE_AUTHOR("Asias He"); MODULE_DESCRIPTION("common code for virtio vsock"); diff --git a/net/vmw_vsock/vsock_bpf.c b/net/vmw_vsock/vsock_bpf.c new file mode 100644 index 000000000000..9c71c163c684 --- /dev/null +++ b/net/vmw_vsock/vsock_bpf.c @@ -0,0 +1,174 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2022 Bobby Eshleman bobby.eshleman@bytedance.com + * + * Based off of net/unix/unix_bpf.c + */ + +#include <linux/bpf.h> +#include <linux/module.h> +#include <linux/skmsg.h> +#include <linux/socket.h> +#include <linux/wait.h> +#include <net/af_vsock.h> +#include <net/sock.h> + +#define vsock_sk_has_data(__sk, __psock) \ + ({ !skb_queue_empty(&(__sk)->sk_receive_queue) || \ + !skb_queue_empty(&(__psock)->ingress_skb) || \ + !list_empty(&(__psock)->ingress_msg); \ + }) + +static struct proto *vsock_prot_saved __read_mostly; +static DEFINE_SPINLOCK(vsock_prot_lock); +static struct proto vsock_bpf_prot; + +static bool vsock_has_data(struct sock *sk, struct sk_psock *psock) +{ + struct vsock_sock *vsk = vsock_sk(sk); + s64 ret; + + ret = vsock_connectible_has_data(vsk); + if (ret > 0) + return true; + + return vsock_sk_has_data(sk, psock); +} + +static bool vsock_msg_wait_data(struct sock *sk, struct sk_psock *psock, long timeo) +{ + int ret; + + DEFINE_WAIT_FUNC(wait, woken_wake_function); + + if (sk->sk_shutdown & RCV_SHUTDOWN) + return true; + + if (!timeo) + return false; + + add_wait_queue(sk_sleep(sk), &wait); + sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk); + ret = vsock_has_data(sk, psock); + if (!ret) { + wait_woken(&wait, TASK_INTERRUPTIBLE, timeo); + ret = vsock_has_data(sk, psock); + } + sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk); + remove_wait_queue(sk_sleep(sk), &wait); + return ret; +} + +static int __vsock_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int flags) +{ + struct socket *sock = sk->sk_socket; + int err; + + if (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) + err = vsock_connectible_recvmsg(sock, msg, len, flags); + else if (sk->sk_type == SOCK_DGRAM) + err = vsock_dgram_recvmsg(sock, msg, len, flags); + else + err = -EPROTOTYPE; + + return err; +} + +static int vsock_bpf_recvmsg(struct sock *sk, struct msghdr *msg, + size_t len, int flags, int *addr_len) +{ + struct sk_psock *psock; + int copied; + + psock = sk_psock_get(sk); + if (unlikely(!psock)) + return __vsock_recvmsg(sk, msg, len, flags); + + lock_sock(sk); + if (vsock_has_data(sk, psock) && sk_psock_queue_empty(psock)) { + release_sock(sk); + sk_psock_put(sk, psock); + return __vsock_recvmsg(sk, msg, len, flags); + } + + copied = sk_msg_recvmsg(sk, psock, msg, len, flags); + while (copied == 0) { + long timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); + + if (!vsock_msg_wait_data(sk, psock, timeo)) { + copied = -EAGAIN; + break; + } + + if (sk_psock_queue_empty(psock)) { + release_sock(sk); + sk_psock_put(sk, psock); + return __vsock_recvmsg(sk, msg, len, flags); + } + + copied = sk_msg_recvmsg(sk, psock, msg, len, flags); + } + + release_sock(sk); + sk_psock_put(sk, psock); + + return copied; +} + +/* Copy of original proto with updated sock_map methods */ +static struct proto vsock_bpf_prot = { + .close = sock_map_close, + .recvmsg = vsock_bpf_recvmsg, + .sock_is_readable = sk_msg_is_readable, + .unhash = sock_map_unhash, +}; + +static void vsock_bpf_rebuild_protos(struct proto *prot, const struct proto *base) +{ + *prot = *base; + prot->close = sock_map_close; + prot->recvmsg = vsock_bpf_recvmsg; + prot->sock_is_readable = sk_msg_is_readable; +} + +static void vsock_bpf_check_needs_rebuild(struct proto *ops) +{ + /* Paired with the smp_store_release() below. */ + if (unlikely(ops != smp_load_acquire(&vsock_prot_saved))) { + spin_lock_bh(&vsock_prot_lock); + if (likely(ops != vsock_prot_saved)) { + vsock_bpf_rebuild_protos(&vsock_bpf_prot, ops); + /* Make sure proto function pointers are updated before publishing the + * pointer to the struct. + */ + smp_store_release(&vsock_prot_saved, ops); + } + spin_unlock_bh(&vsock_prot_lock); + } +} + +int vsock_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore) +{ + struct vsock_sock *vsk; + + if (restore) { + sk->sk_write_space = psock->saved_write_space; + sock_replace_proto(sk, psock->sk_proto); + return 0; + } + + vsk = vsock_sk(sk); + if (!vsk->transport) + return -ENODEV; + + if (!vsk->transport->read_skb) + return -EOPNOTSUPP; + + vsock_bpf_check_needs_rebuild(psock->sk_proto); + sock_replace_proto(sk, &vsock_bpf_prot); + return 0; +} + +void __init vsock_bpf_build_proto(void) +{ + vsock_bpf_rebuild_protos(&vsock_bpf_prot, &vsock_proto); +} diff --git a/net/vmw_vsock/vsock_loopback.c b/net/vmw_vsock/vsock_loopback.c index 671e03240fc5..40753b661c13 100644 --- a/net/vmw_vsock/vsock_loopback.c +++ b/net/vmw_vsock/vsock_loopback.c @@ -94,6 +94,8 @@ static struct virtio_transport loopback_transport = { .notify_send_pre_enqueue = virtio_transport_notify_send_pre_enqueue, .notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue, .notify_buffer_size = virtio_transport_notify_buffer_size, + + .read_skb = virtio_transport_read_skb, },
.send_pkt = vsock_loopback_send_pkt,