Messages in this thread Patch in this message | | | Date | Fri, 20 Jan 2023 09:55:02 +0100 | From | Stefano Garzarella <> | Subject | Re: [PATCH RFC 1/3] vsock: support sockmap |
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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
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