Further work on term resizing platform support for Linux and Windows/mintty

This commit is contained in:
Russ Magee 2018-05-26 13:43:09 -07:00
parent 89dd225910
commit f92085bb86
4 changed files with 92 additions and 25 deletions

View File

@ -32,19 +32,21 @@ type cmdSpec struct {
status int
}
// get terminal size using 'stty' command
// (Most portable btwn Linux and MSYS/win32, but
// TODO: remove external dep on 'stty' utility)
func getTermSize() (rows int, cols int, err error) {
var (
wg sync.WaitGroup
)
// Get terminal size using 'stty' command
func GetSize() (cols, rows int, err error) {
cmd := exec.Command("stty", "size")
cmd.Stdin = os.Stdin
out, err := cmd.Output()
//fmt.Printf("out: %#v\n", string(out))
//fmt.Printf("err: %#v\n", err)
fmt.Sscanf(string(out), "%d %d\n", &rows, &cols)
if err != nil {
log.Fatal(err)
log.Println(err)
cols, rows = 80, 24 //failsafe
} else {
fmt.Sscanf(string(out), "%d %d\n", &rows, &cols)
}
return
}
@ -62,8 +64,6 @@ func getTermSize() (rows int, cols int, err error) {
// connection (app-specific, passed through to the server to use or
// ignore at its discretion).
func main() {
var wg sync.WaitGroup
version := "0.1pre (NO WARRANTY)"
var vopt bool
var dbg bool
@ -73,6 +73,7 @@ func main() {
var cmdStr string
var altUser string
var authCookie string
var chaffEnabled bool
var chaffFreqMin uint
var chaffFreqMax uint
var chaffBytesMax uint
@ -86,6 +87,7 @@ func main() {
flag.StringVar(&cmdStr, "x", "", "command to run (default empty - interactive shell)")
flag.StringVar(&altUser, "u", "", "specify alternate user")
flag.StringVar(&authCookie, "a", "", "auth cookie")
flag.BoolVar(&chaffEnabled, "cE", true, "enabled chaff pkts (default true)")
flag.UintVar(&chaffFreqMin, "cfm", 100, "chaff pkt freq min (msecs)")
flag.UintVar(&chaffFreqMax, "cfM", 5000, "chaff pkt freq max (msecs)")
flag.UintVar(&chaffBytesMax, "cbM", 64, "chaff pkt size max (bytes)")
@ -183,7 +185,9 @@ func main() {
// Set up chaffing to server
conn.Chaff(chaffFreqMin, chaffFreqMax, chaffBytesMax) // enable client->server chaffing
conn.EnableChaff()
if chaffEnabled {
conn.EnableChaff()
}
//client reader (from server) goroutine
wg.Add(1)
@ -218,7 +222,7 @@ func main() {
}()
if isInteractive {
handleTermResizes()
handleTermResizes(conn)
// client writer (to server) goroutine
wg.Add(1)

View File

@ -12,7 +12,7 @@ import (
)
// Handle pty resizes (notify server side)
func handleTermResizes() {
func handleTermResizes(conn *hkexsh.Conn) {
rows := 0
cols := 0
@ -25,10 +25,10 @@ func handleTermResizes() {
for range ch {
// Query client's term size so we can communicate it to server
// pty after interactive session starts
rows, cols, err = getTermSize()
cols, rows, err = GetSize()
log.Printf("[rows %v cols %v]\n", rows, cols)
if err != nil {
panic(err)
log.Println(err)
}
termSzPacket := fmt.Sprintf("%d %d", rows, cols)
conn.WritePacket([]byte(termSzPacket), hkexsh.CSOTermSize)

View File

@ -1,8 +1,65 @@
// +build windows
package main
import (
"fmt"
"log"
"time"
hkexsh "blitter.com/go/hkexsh"
)
// Handle pty resizes (notify server side)
func handleTermResizes() {
func handleTermResizes(conn *hkexsh.Conn) {
var hasStty bool
curCols, curRows := 0, 0
_, _, err := GetSize()
// The above may fail if user doesn't have msys 'stty' util
// in PATH. GetSize() will log.Error() once here
if err != nil {
fmt.Println("[1st GetSize:", err, "]")
hasStty = false
} else {
hasStty = true
}
ch := make(chan bool, 1)
if hasStty {
wg.Add(1)
go func() {
defer wg.Done()
for {
ch <- true
time.Sleep(1 * time.Second)
}
}()
}
wg.Add(1)
go func() {
defer wg.Done()
rows := 0
cols := 0
for range ch {
// Query client's term size so we can communicate it to server
// pty after interactive session starts
cols, rows, err = GetSize()
if err == nil {
} else {
fmt.Println("[GetSize:", err, "]")
}
if (curRows != rows) || (curCols != curCols) {
curRows = rows
curCols = cols
if err != nil {
log.Println(err)
}
termSzPacket := fmt.Sprintf("%d %d", curRows, curCols)
conn.WritePacket([]byte(termSzPacket), hkexsh.CSOTermSize)
}
}
}()
ch <- true // Initial resize
}

View File

@ -79,7 +79,7 @@ func runCmdAs(who string, cmd string, conn hkex.Conn) (err error) {
// Run a command (via default shell) as a specific user
//
// Uses ptys to support commands which expect a terminal.
func runShellAs(who string, cmd string, interactive bool, conn hkexsh.Conn) (err error) {
func runShellAs(who string, cmd string, interactive bool, conn hkexsh.Conn, chaffing bool) (err error) {
u, _ := user.Lookup(who)
var uid, gid uint32
fmt.Sscanf(u.Uid, "%d", &uid)
@ -134,7 +134,9 @@ func runShellAs(who string, cmd string, interactive bool, conn hkexsh.Conn) (err
_, _ = io.Copy(ptmx, conn)
}()
conn.EnableChaff()
if chaffing {
conn.EnableChaff()
}
// ..and the pty to stdout.
_, _ = io.Copy(conn, ptmx)
@ -160,6 +162,7 @@ func rejectUserMsg() string {
func main() {
version := "0.1pre (NO WARRANTY)"
var vopt bool
var chaffEnabled bool
var chaffFreqMin uint
var chaffFreqMax uint
var chaffBytesMax uint
@ -168,6 +171,7 @@ func main() {
flag.BoolVar(&vopt, "v", false, "show version")
flag.StringVar(&laddr, "l", ":2000", "interface[:port] to listen")
flag.BoolVar(&chaffEnabled, "cE", true, "enabled chaff pkts (default true)")
flag.UintVar(&chaffFreqMin, "cfm", 100, "chaff pkt freq min (msecs)")
flag.UintVar(&chaffFreqMax, "cfM", 5000, "chaff pkt freq max (msecs)")
flag.UintVar(&chaffBytesMax, "cbM", 64, "chaff pkt size max (bytes)")
@ -175,7 +179,7 @@ func main() {
flag.Parse()
if vopt {
fmt.Printf("version v%s\n", version)
fmt.Printf("version v%s\n", version)
os.Exit(0)
}
@ -205,7 +209,9 @@ func main() {
log.Println("Accepted client")
// Set up chaffing to client
conn.Chaff(chaffFreqMin, chaffFreqMax, chaffBytesMax) // enable client->server chaffing
// Will only start when runShellAs() is called
// after stdin/stdout are hooked up
conn.Chaff(chaffFreqMin, chaffFreqMax, chaffBytesMax) // configure server->client chaffing
// Handle the connection in a new goroutine.
// The loop then returns to accepting, so that
@ -276,14 +282,14 @@ func main() {
if rec.op[0] == 'c' {
// Non-interactive command
log.Println("[Running command]")
runShellAs(string(rec.who), string(rec.cmd), false, conn)
runShellAs(string(rec.who), string(rec.cmd), false, conn, chaffEnabled)
// Returned hopefully via an EOF or exit/logout;
// Clear current op so user can enter next, or EOF
rec.op[0] = 0
log.Println("[Command complete]")
} else if rec.op[0] == 's' {
log.Println("[Running shell]")
runShellAs(string(rec.who), string(rec.cmd), true, conn)
runShellAs(string(rec.who), string(rec.cmd), true, conn, chaffEnabled)
// Returned hopefully via an EOF or exit/logout;
// Clear current op so user can enter next, or EOF
rec.op[0] = 0