Messages in this thread | | | Date | Thu, 19 Jan 2023 11:39:36 +0100 | From | Stefano Garzarella <> | Subject | Re: [PATCH RFC 1/3] vsock: support sockmap |
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On Wed, Jan 18, 2023 at 12:27:39PM -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@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 | 59 +++++++++-- > net/vmw_vsock/virtio_transport.c | 2 + > net/vmw_vsock/virtio_transport_common.c | 22 ++++ > net/vmw_vsock/vsock_bpf.c | 180 ++++++++++++++++++++++++++++++++ > net/vmw_vsock/vsock_loopback.c | 2 + > 9 files changed, 279 insertions(+), 6 deletions(-)
./scripts/checkpatch.pl --strict prints some simple warnings/checks that I suggest to fix :-)
> >diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c >index 1f3b89c885cca..3c6dc036b9044 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 3f9c166113063..c58453699ee98 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 568a87c5e0d0f..a73f5fbd296af 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 6a943ec95c4a5..5da74c4a9f1d1 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 d593d5b6d4b15..7081b3a992c1e 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 +1135,19 @@ 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); >+ >+ if (!vsk->transport) >+ return -ENODEV; >+ >+ if (!vsk->transport->read_skb) >+ return -EOPNOTSUPP; >+ >+ return vsk->transport->read_skb(vsk, read_actor); >+} >+ > static int vsock_dgram_sendmsg(struct socket *sock, struct msghdr *msg, > size_t len) > { >@@ -1241,19 +1258,32 @@ 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;
Why we need this change? If it's a fix, we should put it in another patch.
> > 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); >+ const struct proto *prot;
We should use the guard for this statement as in vsock_connectible_recvmsg().
>+ 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 +1302,7 @@ 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) >@@ -2085,13 +2116,16 @@ 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; >@@ -2138,6 +2172,14 @@ 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 >@@ -2147,6 +2189,7 @@ 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) > { >@@ -2187,6 +2230,7 @@ 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 = { >@@ -2208,6 +2252,7 @@ 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, >@@ -2347,6 +2392,8 @@ 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 28b5a8e8e0948..e95df847176b6 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 a1581c77cf84a..9a87ead5b1fc5 100644 >--- a/net/vmw_vsock/virtio_transport_common.c >+++ b/net/vmw_vsock/virtio_transport_common.c >@@ -1388,6 +1388,28 @@ 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 copied = 0;
We could avoid initializing `copied`, since it is overwritten later.
>+ int off = 0; >+ int err; >+ >+ spin_lock_bh(&vvs->rx_lock); >+ skb = __skb_recv_datagram(sk, &vvs->rx_queue, MSG_DONTWAIT, &off, &err);
Will this work also for STREAM and SEQPACKET sockets?
>+ spin_unlock_bh(&vvs->rx_lock); >+ >+ if (!skb) >+ return err; >+ >+ copied = recv_actor(sk, skb); >+ kfree_skb(skb);
I would have moved these steps to vsock_read_skb() to avoid duplicating these steps in each transport. Perhaps not all transports want to pass skb ownership to the caller, though, so maybe we can leave it that way for now.
>+ 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 0000000000000..9e11282d3bc1f >--- /dev/null >+++ b/net/vmw_vsock/vsock_bpf.c >@@ -0,0 +1,180 @@ >+// 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 <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_dgram_prot_saved __read_mostly; >+static DEFINE_SPINLOCK(vsock_dgram_prot_lock); >+static struct proto vsock_dgram_bpf_prot; >+ >+static bool vsock_has_data(struct vsock_sock *vsk, struct sk_psock *psock) >+{ >+ struct sock *sk = sk_vsock(vsk); >+ 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) >+{ >+ struct vsock_sock *vsk; >+ int err; >+ >+ DEFINE_WAIT(wait); >+ >+ vsk = vsock_sk(sk); >+ err = 0; >+ >+ while (vsock_has_data(vsk, psock)) { >+ prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); >+ >+ if (sk->sk_err != 0 || >+ (sk->sk_shutdown & RCV_SHUTDOWN) || >+ (vsk->peer_shutdown & SEND_SHUTDOWN)) { >+ break; >+ } >+ >+ if (timeo == 0) { >+ err = -EAGAIN; >+ break; >+ } >+ >+ release_sock(sk); >+ timeo = schedule_timeout(timeo); >+ lock_sock(sk); >+ >+ if (signal_pending(current)) { >+ err = sock_intr_errno(timeo); >+ break; >+ } else if (timeo == 0) { >+ err = -EAGAIN; >+ break; >+ } >+ } >+ >+ finish_wait(sk_sleep(sk), &wait); >+ >+ if (err) >+ return err; >+ >+ return 0; >+} >+ >+static int vsock_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int flags) >+{ >+ int err; >+ struct socket *sock = sk->sk_socket; >+ >+ if (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET) >+ err = vsock_connectible_recvmsg(sock, msg, len, flags); >+ else
Could it happen that it is not DGRAM and we should return an error in this case?
Thanks, Stefano
>+ err = vsock_dgram_recvmsg(sock, msg, len, flags); >+ >+ return err; >+} >+ >+static int vsock_bpf_recvmsg(struct sock *sk, struct msghdr *msg, >+ size_t len, int flags, int *addr_len) >+{ >+ int copied; >+ struct sk_psock *psock; >+ >+ lock_sock(sk); >+ psock = sk_psock_get(sk); >+ if (unlikely(!psock)) { >+ release_sock(sk); >+ return vsock_recvmsg(sk, msg, len, flags); >+ } >+ >+ if (vsock_has_data(vsock_sk(sk), psock) && sk_psock_queue_empty(psock)) { >+ sk_psock_put(sk, psock); >+ release_sock(sk); >+ return vsock_recvmsg(sk, msg, len, flags); >+ } >+ >+msg_bytes_ready: >+ 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; >+ sk_psock_put(sk, psock); >+ release_sock(sk); >+ return vsock_recvmsg(sk, msg, len, flags); >+ } >+ copied = -EAGAIN; >+ } >+ sk_psock_put(sk, psock); >+ release_sock(sk); >+ >+ return copied; >+} >+ >+/* Copy of original proto with updated sock_map methods */ >+static struct proto vsock_dgram_bpf_prot = { >+ .close = sock_map_close, >+ .recvmsg = vsock_bpf_recvmsg, >+ .sock_is_readable = sk_msg_is_readable, >+ .unhash = sock_map_unhash, >+}; >+ >+static void vsock_dgram_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_dgram_bpf_check_needs_rebuild(struct proto *ops) >+{ >+ if (unlikely(ops != smp_load_acquire(&vsock_dgram_prot_saved))) { >+ spin_lock_bh(&vsock_dgram_prot_lock); >+ if (likely(ops != vsock_dgram_prot_saved)) { >+ vsock_dgram_bpf_rebuild_protos(&vsock_dgram_bpf_prot, ops); >+ smp_store_release(&vsock_dgram_prot_saved, ops); >+ } >+ spin_unlock_bh(&vsock_dgram_prot_lock); >+ } >+} >+ >+int vsock_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore) >+{ >+ if (restore) { >+ sk->sk_write_space = psock->saved_write_space; >+ sock_replace_proto(sk, psock->sk_proto); >+ return 0; >+ } >+ >+ vsock_dgram_bpf_check_needs_rebuild(psock->sk_proto); >+ sock_replace_proto(sk, &vsock_dgram_bpf_prot); >+ return 0; >+} >+ >+void __init vsock_bpf_build_proto(void) >+{ >+ vsock_dgram_bpf_rebuild_protos(&vsock_dgram_bpf_prot, &vsock_proto); >+} >diff --git a/net/vmw_vsock/vsock_loopback.c b/net/vmw_vsock/vsock_loopback.c >index 671e03240fc52..40753b661c135 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, > >-- >2.30.2 >
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