Files
podman/vendor/github.com/hugelgupf/p9/vecnet/vecnet.go
Matthew Heon 642fa98976 Initial addition of 9p code to Podman
This includes two new hidden commands: a 9p server,
`podman machine server9p`, and a 9p client,
`podman machine client9p` with `server9p` currently only
configured to run on Windows and serve 9p via HyperV vsock, and
`client9p` only configured to run on Linux. The server is run by
`podman machine start` and has the same lifespan as gvproxy
(waits for the gvproxy PID to die before shutting down). The
client is run inside the VM, also by `podman machine start`, and
mounts uses kernel 9p mount code to complete the mount. It's
unfortunately not possible to use mount directly without the
wrapper; we need to set up the vsock and pass it to mount as an
FD.

In theory this can be generalized so that the server can run
anywhere and over almost any transport, but I haven't done this
here as I don't think we have a usecase other than HyperV right
now.

[NO NEW TESTS NEEDED] This requires changes to Podman in the VM,
so we need to wait until a build with this lands in FCOS to test.

Signed-off-by: Matthew Heon <matthew.heon@pm.me>
2023-10-31 10:14:02 -04:00

55 lines
1.6 KiB
Go

// Copyright 2018 The gVisor Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Package vecnet provides access to recvmsg syscalls on net.Conns.
package vecnet
import (
"io"
"net"
"syscall"
)
// Buffers points to zero or more buffers to read into.
//
// On connections that support it, ReadFrom is optimized into the batch read
// operation recvmsg.
type Buffers net.Buffers
// ReadFrom reads into the pre-allocated bufs. Returns bytes read.
//
// ReadFrom keeps reading until all bufs are filled or EOF is received.
//
// The pre-allocatted space used by ReadFrom is based upon slice lengths.
func (bufs Buffers) ReadFrom(r io.Reader) (int64, error) {
if conn, ok := r.(syscall.Conn); ok && readFromBuffers != nil {
return readFromBuffers(bufs, conn)
}
var total int64
for _, buf := range bufs {
for filled := 0; filled < len(buf); {
n, err := r.Read(buf[filled:])
total += int64(n)
filled += n
if (n == 0 && err == nil) || err == io.EOF {
return total, io.EOF
} else if err != nil {
return total, err
}
}
}
return total, nil
}