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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /net/vmw_vsock/vsock_bpf.c
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'net/vmw_vsock/vsock_bpf.c')
-rw-r--r--net/vmw_vsock/vsock_bpf.c174
1 files changed, 174 insertions, 0 deletions
diff --git a/net/vmw_vsock/vsock_bpf.c b/net/vmw_vsock/vsock_bpf.c
new file mode 100644
index 0000000000..a3c97546ab
--- /dev/null
+++ b/net/vmw_vsock/vsock_bpf.c
@@ -0,0 +1,174 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2022 Bobby Eshleman <bobby.eshleman@bytedance.com>
+ *
+ * Based off of net/unix/unix_bpf.c
+ */
+
+#include <linux/bpf.h>
+#include <linux/module.h>
+#include <linux/skmsg.h>
+#include <linux/socket.h>
+#include <linux/wait.h>
+#include <net/af_vsock.h>
+#include <net/sock.h>
+
+#define vsock_sk_has_data(__sk, __psock) \
+ ({ !skb_queue_empty(&(__sk)->sk_receive_queue) || \
+ !skb_queue_empty(&(__psock)->ingress_skb) || \
+ !list_empty(&(__psock)->ingress_msg); \
+ })
+
+static struct proto *vsock_prot_saved __read_mostly;
+static DEFINE_SPINLOCK(vsock_prot_lock);
+static struct proto vsock_bpf_prot;
+
+static bool vsock_has_data(struct sock *sk, struct sk_psock *psock)
+{
+ struct vsock_sock *vsk = vsock_sk(sk);
+ s64 ret;
+
+ ret = vsock_connectible_has_data(vsk);
+ if (ret > 0)
+ return true;
+
+ return vsock_sk_has_data(sk, psock);
+}
+
+static bool vsock_msg_wait_data(struct sock *sk, struct sk_psock *psock, long timeo)
+{
+ bool ret;
+
+ DEFINE_WAIT_FUNC(wait, woken_wake_function);
+
+ if (sk->sk_shutdown & RCV_SHUTDOWN)
+ return true;
+
+ if (!timeo)
+ return false;
+
+ add_wait_queue(sk_sleep(sk), &wait);
+ sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
+ ret = vsock_has_data(sk, psock);
+ if (!ret) {
+ wait_woken(&wait, TASK_INTERRUPTIBLE, timeo);
+ ret = vsock_has_data(sk, psock);
+ }
+ sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
+ remove_wait_queue(sk_sleep(sk), &wait);
+ return ret;
+}
+
+static int __vsock_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int flags)
+{
+ struct socket *sock = sk->sk_socket;
+ int err;
+
+ if (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET)
+ err = vsock_connectible_recvmsg(sock, msg, len, flags);
+ else if (sk->sk_type == SOCK_DGRAM)
+ err = vsock_dgram_recvmsg(sock, msg, len, flags);
+ else
+ err = -EPROTOTYPE;
+
+ return err;
+}
+
+static int vsock_bpf_recvmsg(struct sock *sk, struct msghdr *msg,
+ size_t len, int flags, int *addr_len)
+{
+ struct sk_psock *psock;
+ int copied;
+
+ psock = sk_psock_get(sk);
+ if (unlikely(!psock))
+ return __vsock_recvmsg(sk, msg, len, flags);
+
+ lock_sock(sk);
+ if (vsock_has_data(sk, psock) && sk_psock_queue_empty(psock)) {
+ release_sock(sk);
+ sk_psock_put(sk, psock);
+ return __vsock_recvmsg(sk, msg, len, flags);
+ }
+
+ copied = sk_msg_recvmsg(sk, psock, msg, len, flags);
+ while (copied == 0) {
+ long timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
+
+ if (!vsock_msg_wait_data(sk, psock, timeo)) {
+ copied = -EAGAIN;
+ break;
+ }
+
+ if (sk_psock_queue_empty(psock)) {
+ release_sock(sk);
+ sk_psock_put(sk, psock);
+ return __vsock_recvmsg(sk, msg, len, flags);
+ }
+
+ copied = sk_msg_recvmsg(sk, psock, msg, len, flags);
+ }
+
+ release_sock(sk);
+ sk_psock_put(sk, psock);
+
+ return copied;
+}
+
+/* Copy of original proto with updated sock_map methods */
+static struct proto vsock_bpf_prot = {
+ .close = sock_map_close,
+ .recvmsg = vsock_bpf_recvmsg,
+ .sock_is_readable = sk_msg_is_readable,
+ .unhash = sock_map_unhash,
+};
+
+static void vsock_bpf_rebuild_protos(struct proto *prot, const struct proto *base)
+{
+ *prot = *base;
+ prot->close = sock_map_close;
+ prot->recvmsg = vsock_bpf_recvmsg;
+ prot->sock_is_readable = sk_msg_is_readable;
+}
+
+static void vsock_bpf_check_needs_rebuild(struct proto *ops)
+{
+ /* Paired with the smp_store_release() below. */
+ if (unlikely(ops != smp_load_acquire(&vsock_prot_saved))) {
+ spin_lock_bh(&vsock_prot_lock);
+ if (likely(ops != vsock_prot_saved)) {
+ vsock_bpf_rebuild_protos(&vsock_bpf_prot, ops);
+ /* Make sure proto function pointers are updated before publishing the
+ * pointer to the struct.
+ */
+ smp_store_release(&vsock_prot_saved, ops);
+ }
+ spin_unlock_bh(&vsock_prot_lock);
+ }
+}
+
+int vsock_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore)
+{
+ struct vsock_sock *vsk;
+
+ if (restore) {
+ sk->sk_write_space = psock->saved_write_space;
+ sock_replace_proto(sk, psock->sk_proto);
+ return 0;
+ }
+
+ vsk = vsock_sk(sk);
+ if (!vsk->transport)
+ return -ENODEV;
+
+ if (!vsk->transport->read_skb)
+ return -EOPNOTSUPP;
+
+ vsock_bpf_check_needs_rebuild(psock->sk_proto);
+ sock_replace_proto(sk, &vsock_bpf_prot);
+ return 0;
+}
+
+void __init vsock_bpf_build_proto(void)
+{
+ vsock_bpf_rebuild_protos(&vsock_bpf_prot, &vsock_proto);
+}