recon_unix.go

// +build freebsd openbsd dragonfly netbsd darwin solaris illumos

package kitty

import (
	"bufio"
	"encoding/json"
	"io"
	"net"
	"syscall"

	"github.com/ftrvxmtrx/fd"
	"github.com/ugjka/ircmsg"
)

// startUnixListener starts up a unix domain socket listener for reconnects to
// be sent through
func (bot *Bot) startUnixListener() {
	defer bot.wg.Done()
	unaddr, err := net.ResolveUnixAddr("unix", bot.unixsock)
	if err != nil {
		panic(err)
	}

	// Unlink the socket so we don't have to worry about removing it
	// We can ignore any error here
	syscall.Unlink(bot.unixsock)

	list, err := net.ListenUnix("unix", unaddr)
	if err != nil {
		panic(err)
	}
	bot.mu.Lock()
	bot.unixlist = list
	bot.mu.Unlock()
	con, err := list.AcceptUnix()
	if err != nil {
		return
	}
	defer con.Close()
	list.Close()

	fi, err := bot.con.(*net.TCPConn).File()
	if err != nil {
		panic(err)
	}
	err = fd.Put(con, fi)
	if err != nil {
		panic(err)
	}

	// Send own prefix and CAPs
	_, err = io.WriteString(con, bot.Prefix().String()+"\n")
	if err != nil {
		panic(err)
	}
	err = json.NewEncoder(con).Encode(bot.capHandler.capsEnabled)
	if err != nil {
		panic(err)
	}
	bot.close("", nil)
	bot.hijacked = true
}

// Attempt to hijack session previously running bot
func (bot *Bot) hijackSession() bool {
	con, err := net.Dial("unix", bot.unixsock)
	if err != nil {
		bot.Info("Couldnt restablish connection, no prior bot.", "err", err)
		return false
	}
	defer con.Close()
	ncon, err := fd.Get(con.(*net.UnixConn), 1, nil)
	if err != nil {
		panic(err)
	}
	defer ncon[0].Close()

	netcon, err := net.FileConn(ncon[0])
	if err != nil {
		panic(err)
	}

	// Read the reminder which should be our prefix and CAPs
	sc := bufio.NewScanner(con)
	if !sc.Scan() {
		panic(sc.Err())
	}
	bot.prefixMu.Lock()
	bot.prefix = ircmsg.ParsePrefix(sc.Text())
	bot.prefixMu.Unlock()
	if !sc.Scan() {
		panic(sc.Err())
	}
	err = json.Unmarshal(sc.Bytes(), &bot.capHandler.capsEnabled)
	if err != nil {
		panic(err)
	}
	bot.reconnecting = true
	bot.con = netcon
	return true
}