diff options
Diffstat (limited to 'vendor/github.com/containerd/go-runc/console.go')
-rw-r--r-- | vendor/github.com/containerd/go-runc/console.go | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/vendor/github.com/containerd/go-runc/console.go b/vendor/github.com/containerd/go-runc/console.go new file mode 100644 index 000000000..ff223e427 --- /dev/null +++ b/vendor/github.com/containerd/go-runc/console.go @@ -0,0 +1,165 @@ +// +build !windows + +/* + Copyright The containerd 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 runc + +import ( + "fmt" + "io/ioutil" + "net" + "os" + "path/filepath" + + "github.com/containerd/console" + "golang.org/x/sys/unix" +) + +// NewConsoleSocket creates a new unix socket at the provided path to accept a +// pty master created by runc for use by the container +func NewConsoleSocket(path string) (*Socket, error) { + abs, err := filepath.Abs(path) + if err != nil { + return nil, err + } + addr, err := net.ResolveUnixAddr("unix", abs) + if err != nil { + return nil, err + } + l, err := net.ListenUnix("unix", addr) + if err != nil { + return nil, err + } + return &Socket{ + l: l, + }, nil +} + +// NewTempConsoleSocket returns a temp console socket for use with a container +// On Close(), the socket is deleted +func NewTempConsoleSocket() (*Socket, error) { + runtimeDir := os.Getenv("XDG_RUNTIME_DIR") + dir, err := ioutil.TempDir(runtimeDir, "pty") + if err != nil { + return nil, err + } + abs, err := filepath.Abs(filepath.Join(dir, "pty.sock")) + if err != nil { + return nil, err + } + addr, err := net.ResolveUnixAddr("unix", abs) + if err != nil { + return nil, err + } + l, err := net.ListenUnix("unix", addr) + if err != nil { + return nil, err + } + if runtimeDir != "" { + if err := os.Chmod(abs, 0755|os.ModeSticky); err != nil { + return nil, err + } + } + return &Socket{ + l: l, + rmdir: true, + }, nil +} + +// Socket is a unix socket that accepts the pty master created by runc +type Socket struct { + rmdir bool + l *net.UnixListener +} + +// Path returns the path to the unix socket on disk +func (c *Socket) Path() string { + return c.l.Addr().String() +} + +// recvFd waits for a file descriptor to be sent over the given AF_UNIX +// socket. The file name of the remote file descriptor will be recreated +// locally (it is sent as non-auxiliary data in the same payload). +func recvFd(socket *net.UnixConn) (*os.File, error) { + const MaxNameLen = 4096 + var oobSpace = unix.CmsgSpace(4) + + name := make([]byte, MaxNameLen) + oob := make([]byte, oobSpace) + + n, oobn, _, _, err := socket.ReadMsgUnix(name, oob) + if err != nil { + return nil, err + } + + if n >= MaxNameLen || oobn != oobSpace { + return nil, fmt.Errorf("recvfd: incorrect number of bytes read (n=%d oobn=%d)", n, oobn) + } + + // Truncate. + name = name[:n] + oob = oob[:oobn] + + scms, err := unix.ParseSocketControlMessage(oob) + if err != nil { + return nil, err + } + if len(scms) != 1 { + return nil, fmt.Errorf("recvfd: number of SCMs is not 1: %d", len(scms)) + } + scm := scms[0] + + fds, err := unix.ParseUnixRights(&scm) + if err != nil { + return nil, err + } + if len(fds) != 1 { + return nil, fmt.Errorf("recvfd: number of fds is not 1: %d", len(fds)) + } + fd := uintptr(fds[0]) + + return os.NewFile(fd, string(name)), nil +} + +// ReceiveMaster blocks until the socket receives the pty master +func (c *Socket) ReceiveMaster() (console.Console, error) { + conn, err := c.l.Accept() + if err != nil { + return nil, err + } + defer conn.Close() + uc, ok := conn.(*net.UnixConn) + if !ok { + return nil, fmt.Errorf("received connection which was not a unix socket") + } + f, err := recvFd(uc) + if err != nil { + return nil, err + } + return console.ConsoleFromFile(f) +} + +// Close closes the unix socket +func (c *Socket) Close() error { + err := c.l.Close() + if c.rmdir { + if rerr := os.RemoveAll(filepath.Dir(c.Path())); err == nil { + err = rerr + } + } + return err +} |