tool.go

/*
Copyright (c) 2014 VMware, Inc. All Rights Reserved.

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 ipmi

import (
	"bytes"
	"encoding/hex"
	"fmt"
	"io"
	"os"
	"os/exec"
	"strconv"
	"strings"
)

type tool struct {
	*Connection
}

func newToolTransport(c *Connection) transport {
	return &tool{Connection: c}
}

func (t *tool) open() error {
	return nil
}

func (t *tool) close() error {
	return nil
}

func (t *tool) send(req *Request, res Response) error {
	// ipmitool ... raw .. .. ..
	args := append([]string{"raw"}, requestToStrings(req)...)

	output, err := t.run(args...)
	if err != nil {
		// TODO: parse CompletionCode from stderr
		return err
	}

	return responseFromString(output, res)
}

func (t *tool) Console(outWriter io.Writer, errWriter io.Writer) error {
	cmd := t.cmd("sol", "activate", "-e", "&")
	cmd.Stdin = os.Stdin
	cmd.Stdout = outWriter
	cmd.Stderr = errWriter
	return cmd.Run()
}

func (t *tool) options() []string {
	intf := t.Interface
	if intf == "" {
		intf = "lanplus"
	}

	options := []string{
		"-H", t.Hostname,
		"-U", t.Username,
		"-P", t.Password,
		"-I", intf,
	}

	if t.Port != 0 {
		options = append(options, "-p", strconv.Itoa(t.Port))
	}

	return options
}

func (t *tool) cmd(args ...string) *exec.Cmd {
	path := t.Path
	opts := append(t.options(), args...)

	if path == "" {
		path = "ipmitool"
	}

	return exec.Command(path, opts...)

}

func (t *tool) run(args ...string) (string, error) {
	cmd := t.cmd(args...)
	var stdout bytes.Buffer
	var stderr bytes.Buffer
	cmd.Stdout = &stdout
	cmd.Stderr = &stderr

	err := cmd.Run()
	if err != nil {
		return "", fmt.Errorf("run %s %s: %s (%s)",
			cmd.Path, strings.Join(cmd.Args, " "), stderr.String(), err)
	}

	return stdout.String(), err
}

func requestToBytes(r *Request) []byte {
	data := messageDataToBytes(r.Data)
	msg := make([]byte, 2+len(data))
	msg[0] = uint8(r.NetworkFunction)
	msg[1] = uint8(r.Command)
	copy(msg[2:], data)
	return msg
}

func requestToStrings(r *Request) []string {
	msg := requestToBytes(r)
	return rawEncode(msg)
}

func responseFromBytes(msg []byte, r Response) error {
	buf := make([]byte, 1+len(msg))
	buf[0] = uint8(CommandCompleted)
	copy(buf[1:], msg)
	return messageDataFromBytes(buf, r)
}

func responseFromString(s string, r Response) error {
	// Remove trailing spaces and newlines from string received.
	msg := rawDecode(strings.Replace(strings.TrimSpace(s), "\n", "", -1))
	return responseFromBytes(msg, r)
}

func rawDecode(data string) []byte {
	var buf bytes.Buffer

	for _, s := range strings.Split(data, " ") {
		b, err := hex.DecodeString(s)
		if err != nil {
			panic(err)
		}

		_, err = buf.Write(b)
		if err != nil {
			panic(err)
		}
	}

	return buf.Bytes()
}

func rawEncode(data []byte) []string {
	n := len(data)
	buf := make([]string, 0, n)

	// ipmitool needs every byte to be a separate argument
	for i := 0; i < n; i++ {
		buf = append(buf, "0x"+hex.EncodeToString(data[i:i+1]))
	}

	return buf
}