m6220-proxy: make cli iface into library
Change-Id: Ieededb08a930d7b862575cc569d467cdd93e3e0d
Reviewed-on: https://gerrit.hackerspace.pl/c/hscloud/+/1156
Reviewed-by: q3k <q3k@hackerspace.pl>
diff --git a/dc/m6220-proxy/cli/cli.go b/dc/m6220-proxy/cli/cli.go
new file mode 100644
index 0000000..2e89ca8
--- /dev/null
+++ b/dc/m6220-proxy/cli/cli.go
@@ -0,0 +1,242 @@
+package cli
+
+import (
+ "context"
+ "fmt"
+ "strings"
+
+ "github.com/ziutek/telnet"
+ "golang.org/x/net/trace"
+)
+
+type Client struct {
+ conn *telnet.Conn
+
+ username string
+ password string
+
+ loggedIn bool
+ promptHostname string
+}
+
+func NewClient(c *telnet.Conn, username, password string) *Client {
+ return &Client{
+ conn: c,
+ username: username,
+ password: password,
+ }
+}
+
+func (c *Client) readUntil(ctx context.Context, delims ...string) (string, error) {
+ chStr := make(chan string, 1)
+ chErr := make(chan error, 1)
+ go func() {
+ s, err := c.conn.ReadUntil(delims...)
+ if err != nil {
+ chErr <- err
+ return
+ }
+ chStr <- string(s)
+ }()
+
+ select {
+ case <-ctx.Done():
+ return "", fmt.Errorf("context done")
+ case err := <-chErr:
+ c.trace(ctx, "readUntil failed: %v", err)
+ return "", err
+ case s := <-chStr:
+ c.trace(ctx, "readUntil <- %q", s)
+ return s, nil
+
+ }
+}
+
+func (c *Client) readString(ctx context.Context, delim byte) (string, error) {
+ chStr := make(chan string, 1)
+ chErr := make(chan error, 1)
+ go func() {
+ s, err := c.conn.ReadString(delim)
+ if err != nil {
+ chErr <- err
+ return
+ }
+ chStr <- s
+ }()
+
+ select {
+ case <-ctx.Done():
+ return "", fmt.Errorf("context done")
+ case err := <-chErr:
+ c.trace(ctx, "readString failed: %v", err)
+ return "", err
+ case s := <-chStr:
+ c.trace(ctx, "readString <- %q", s)
+ return s, nil
+
+ }
+}
+
+func (c *Client) writeLine(ctx context.Context, s string) error {
+ n, err := c.conn.Write([]byte(s + "\n"))
+ if got, want := n, len(s)+1; got != want {
+ err = fmt.Errorf("wrote %d bytes out of %d", got, want)
+ }
+ if err != nil {
+ c.trace(ctx, "writeLine failed: %v", err)
+ return err
+ }
+ c.trace(ctx, "writeLine -> %q", s)
+ return nil
+}
+
+func (c *Client) trace(ctx context.Context, f string, parts ...interface{}) {
+ tr, ok := trace.FromContext(ctx)
+ if !ok {
+ //fmted := fmt.Sprintf(f, parts...)
+ //glog.Infof("[no trace] %s", fmted)
+ return
+ }
+ tr.LazyPrintf(f, parts...)
+}
+
+func (c *Client) logIn(ctx context.Context) error {
+ if c.loggedIn {
+ return nil
+ }
+
+ // Provide username.
+ prompt, err := c.readString(ctx, ':')
+ if err != nil {
+ return fmt.Errorf("could not read username prompt: %v", err)
+ }
+ if !strings.HasSuffix(prompt, "User:") {
+ return fmt.Errorf("invalid username prompt: %v", err)
+ }
+ if err := c.writeLine(ctx, c.username); err != nil {
+ return fmt.Errorf("could not write username: %v")
+ }
+
+ // Provide password.
+ prompt, err = c.readString(ctx, ':')
+ if err != nil {
+ return fmt.Errorf("could not read password prompt: %v", err)
+ }
+ if !strings.HasSuffix(prompt, "Password:") {
+ return fmt.Errorf("invalid password prompt: %v", err)
+ }
+ if err := c.writeLine(ctx, c.password); err != nil {
+ return fmt.Errorf("could not write password: %v")
+ }
+
+ // Get unprivileged prompt.
+ prompt, err = c.readString(ctx, '>')
+ if err != nil {
+ return fmt.Errorf("could not read unprivileged prompt: %v", err)
+ }
+
+ parts := strings.Split(prompt, "\r\n")
+ c.promptHostname = strings.TrimSuffix(parts[len(parts)-1], ">")
+
+ // Enable privileged mode.
+
+ if err := c.writeLine(ctx, "enable"); err != nil {
+ return fmt.Errorf("could not write enable: %v")
+ }
+
+ // Provide password (again)
+ prompt, err = c.readString(ctx, ':')
+ if err != nil {
+ return fmt.Errorf("could not read password prompt: %v", err)
+ }
+ if !strings.HasSuffix(prompt, "Password:") {
+ return fmt.Errorf("invalid password prompt: %v", err)
+ }
+ if err := c.writeLine(ctx, c.password); err != nil {
+ return fmt.Errorf("could not write password: %v")
+ }
+
+ // Get privileged prompt.
+ prompt, err = c.readString(ctx, '#')
+ if err != nil {
+ return fmt.Errorf("could not read privileged prompt: %v", err)
+ }
+
+ if !strings.HasSuffix(prompt, c.promptHostname+"#") {
+ return fmt.Errorf("unexpected privileged prompt: %v", prompt)
+ }
+
+ // Disable pager.
+ if err := c.writeLine(ctx, "terminal length 0"); err != nil {
+ return fmt.Errorf("could not diable pager: %v", err)
+ }
+ prompt, err = c.readString(ctx, '#')
+ if err != nil {
+ return fmt.Errorf("could not disable pager: %v", err)
+ }
+ if !strings.HasSuffix(prompt, c.promptHostname+"#") {
+ return fmt.Errorf("unexpected privileged prompt: %v", prompt)
+ }
+
+ // Success!
+ c.loggedIn = true
+ c.trace(ctx, "logged into %v", c.promptHostname)
+ return nil
+}
+
+func (c *Client) RunCommand(ctx context.Context, command string) ([]string, string, error) {
+ if err := c.logIn(ctx); err != nil {
+ return nil, "", fmt.Errorf("could not log in: %v", err)
+ }
+
+ // First, synchronize to prompt.
+ attempts := 3
+ for {
+ c.writeLine(ctx, "")
+ line, err := c.readString(ctx, '\n')
+ if err != nil {
+ return nil, "", fmt.Errorf("while synchronizing to prompt: %v", err)
+ }
+ line = strings.Trim(line, "\r\n")
+ if strings.HasSuffix(line, c.promptHostname+"#") {
+ break
+ }
+
+ attempts -= 1
+ if attempts == 0 {
+ return nil, "", fmt.Errorf("could not find prompt, last result %q", line)
+ }
+ }
+
+ // Send comand.
+ c.writeLine(ctx, command)
+
+ // First, read until prompt again.
+ if _, err := c.readUntil(ctx, c.promptHostname+"#"); err != nil {
+ return nil, "", fmt.Errorf("could not get command hostname echo: %v", err)
+ }
+
+ loopback, err := c.readUntil(ctx, "\r\n")
+ if err != nil {
+ return nil, "", fmt.Errorf("could not get command loopback: %v", err)
+ }
+ loopback = strings.Trim(loopback, "\r\n")
+ c.trace(ctx, "effective command: %q", loopback)
+
+ // Read until we have a standalone prompt with no newline afterwards.
+ data, err := c.readUntil(ctx, c.promptHostname+"#")
+ if err != nil {
+ return nil, "", fmt.Errorf("could not get command results: %v", err)
+ }
+
+ lines := []string{}
+ for _, line := range strings.Split(data, "\r\n") {
+ if line == c.promptHostname+"#" {
+ break
+ }
+ lines = append(lines, line)
+ }
+ c.trace(ctx, "command %q returned lines: %v", command, lines)
+
+ return lines, loopback, nil
+}