Stefano Garzarella
2023-Feb-16 10:11 UTC
[PATCH RFC net-next v2 1/3] vsock: support sockmap
On Mon, Jan 30, 2023 at 08:35:12PM -0800, Bobby Eshleman wrote:>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 at 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 | 24 +++++ > net/vmw_vsock/vsock_bpf.c | 175 ++++++++++++++++++++++++++++++++ > 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);checkpatch complains: "CHECK: Alignment should match open parenthesis">+ >+#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..82bdaf61ee02 100644 >--- a/net/vmw_vsock/virtio_transport_common.c >+++ b/net/vmw_vsock/virtio_transport_common.c >@@ -1388,6 +1388,30 @@ 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. */Checkpatch: WARNING: Block comments use a trailing */ on a separate line Since we also use this convention in the other comments in this file, I would follow it.>+ 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..ee92a1f42031 >--- /dev/null >+++ b/net/vmw_vsock/vsock_bpf.c >@@ -0,0 +1,175 @@ >+// SPDX-License-Identifier: GPL-2.0 >+/* Copyright (c) 2022 Bobby Eshleman <bobby.eshleman at 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); \ >+ })Some suggestions from checkpatch that I would fix: CHECK: Macro argument '__sk' may be better as '(__sk)' to avoid precedence issues CHECK: Macro argument '__psock' may be better as '(__psock)' to avoid precedence issues>+ >+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 int vsock_msg_wait_data(struct sock *sk, struct sk_psock *psock, long timeo)IIUC now this function returns 0 when there isn't data and 1 when there is data, maybe better to change the return type to bool.>+{ >+ int ret = 0; >+ >+ DEFINE_WAIT_FUNC(wait, woken_wake_function); >+ >+ if (sk->sk_shutdown & RCV_SHUTDOWN) >+ return 1; >+ >+ if (!timeo) >+ return ret; >+ >+ 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); >+ lock_sock(sk); >+ if (unlikely(!psock)) { >+ release_sock(sk);I'm not sure we need the lock to check psock, so can we move this block before the lock_sock?>+ return __vsock_recvmsg(sk, msg, len, flags); >+ } >+ >+ 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); >+ } >+ >+msg_bytes_ready:I saw that this code is also in unix_bpf.c and tcp_bpf.c, so I guess it's acceptable, but I would have avoided using a label to go back. I prefer a to use goto only for centralized exiting of functions. One possible refactoring (not tested): copied = sk_msg_recvmsg(sk, psock, msg, len, flags); while (!copied) { 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); } ... I'm not sure why we need to call release_sock() and sk_psock_put() before __vsock_recvmsg(). If it is not needed we can simplify more the previous code. The rest LGTM. Thanks, Stefano>+ copied = sk_msg_recvmsg(sk, psock, msg, len, flags); >+ if (!copied) { >+ long timeo; >+ int data; >+ >+ timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); >+ data = vsock_msg_wait_data(sk, psock, timeo); >+ if (data) { >+ if (!sk_psock_queue_empty(psock)) >+ goto msg_bytes_ready; >+ release_sock(sk); >+ sk_psock_put(sk, psock); >+ return __vsock_recvmsg(sk, msg, len, flags); >+ } >+ copied = -EAGAIN; >+ } >+ 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, > >-- >2.35.1 >