[RFC,1/3] vsock: support sockmap
Commit Message
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(-)
Comments
On Thu, Jan 19, 2023 at 11:39:36AM +0100, Stefano Garzarella wrote:
> 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 :-)
>
Oops, thanks. New machine, forgot my pre-commit hook. Putting in place
now.
> >
> > 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.
>
This is just required by sockmap's function that determines if a socket
is a valid one to add to a map. It will refuse to add any socket that is
not TCP_ESTABLISHED to a sockmap.
This was the approach that unix dgrams took, so I followed here.
> >
> > 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().
>
Got it.
> > + 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.
>
Got it.
> > + 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?
>
Yep, it is used for non-datagram sockets as well because it is free of race
conditions, and handles waits/errors sensibly. For example, in
unix_accept():
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/net/unix/af_unix.c#n1696
> > + 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.
>
That is a good point though. I bet your initial hunch is the right one.
If even one other transport duplicates this, then I'd say it is worth
pulling up into vsock_read_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 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?
>
I'm not sure but for the sake of safety, I'll add that.
> Thanks,
> Stefano
>
Thanks for the review Stefano.
Best,
Bobby
On Sat, Jan 21, 2023 at 11:22:31AM -0800, Cong Wang wrote:
> On Wed, Jan 18, 2023 at 12:27:39PM -0800, Bobby Eshleman wrote:
> > +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;
>
> Can we move these two checks to sockmap update path? It would make
> vsock_read_skb() faster.
>
> > +
> > + return vsk->transport->read_skb(vsk, read_actor);
> > +}
>
> Essentially can be just this one line.
>
> Thanks.
That makes sense, will do.
Thanks,
Bobby
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
>
On Wed, Jan 18, 2023 at 03:08:11PM +0000, Bobby Eshleman wrote:
>On Thu, Jan 19, 2023 at 11:39:36AM +0100, Stefano Garzarella wrote:
>> 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 :-)
>>
>
>Oops, thanks. New machine, forgot my pre-commit hook. Putting in place
>now.
>
>> >
>> > 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.
>>
>
>This is just required by sockmap's function that determines if a socket
>is a valid one to add to a map. It will refuse to add any socket that is
>not TCP_ESTABLISHED to a sockmap.
>
>This was the approach that unix dgrams took, so I followed here.
Okay, make sense to me.
Maybe mention that in the commit message.
>
>> >
>> > 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().
>>
>
>Got it.
>
>> > + 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.
>>
>
>Got it.
>
>> > + 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?
>>
>
>Yep, it is used for non-datagram sockets as well because it is free of race
>conditions, and handles waits/errors sensibly. For example, in
>unix_accept():
>
>https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/net/unix/af_unix.c#n1696
Good to know :-)
I'd add a comment, just because the function name suggests something
else.
>
>> > + 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.
>>
>
>That is a good point though. I bet your initial hunch is the right one.
>If even one other transport duplicates this, then I'd say it is worth
>pulling up into vsock_read_skb().
Make sense to me :-)
>
>> > + 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?
>>
>
>I'm not sure but for the sake of safety, I'll add that.
Yep, I agree.
Thanks,
Stefano
On Wed, Jan 18, 2023 at 12:27:39PM -0800, Bobby Eshleman wrote:
> +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;
Can we move these two checks to sockmap update path? It would make
vsock_read_skb() faster.
> +
> + return vsk->transport->read_skb(vsk, read_actor);
> +}
Essentially can be just this one line.
Thanks.
@@ -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,
@@ -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 */
@@ -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__ */
@@ -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
@@ -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;
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;
+ 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:
@@ -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,
@@ -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;
+ int off = 0;
+ int err;
+
+ spin_lock_bh(&vvs->rx_lock);
+ 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");
new file mode 100644
@@ -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
+ 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);
+}
@@ -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,