initial import

go.mod

@@ -0,0 +1,5 @@
+module codeberg.org/madmo/rdebug
+
+go 1.16
+
+require golang.org/x/crypto v0.0.0-20210921155107-089bfa567519 // indirect

go.sum

@@ -0,0 +1,9 @@
+golang.org/x/crypto v0.0.0-20210921155107-089bfa567519 h1:7I4JAnoQBe7ZtJcBaYHi5UtiO8tQHbUSXxL+pnGRANg=
+golang.org/x/crypto v0.0.0-20210921155107-089bfa567519/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
+golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
+golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1 h1:SrN+KX8Art/Sf4HNj6Zcz06G7VEz+7w9tdXTPOZ7+l4=
+golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
+golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=

rdebug.go

@@ -0,0 +1,125 @@
+// Helper script for remote gdb
+package main
+
+import (
+	"bufio"
+	"flag"
+	"fmt"
+	"io"
+	"os"
+	"path"
+	"strconv"
+	"strings"
+
+	"golang.org/x/crypto/ssh"
+)
+
+var (
+	optUser     = flag.String("user", "default", "username for ssh user")
+	optPassword = flag.String("pass", "", "password")
+	optGdbPort  = flag.Uint("port", 10001, "remote gdb port to use")
+)
+
+func main() {
+	flag.Usage = func() {
+		fmt.Fprintf(os.Stderr, "Usage: %s [OPTIONS] hostname program args\n", os.Args[0])
+		flag.PrintDefaults()
+	}
+
+	flag.Parse()
+
+	if flag.NArg() < 2 {
+		flag.Usage()
+		os.Exit(2)
+	}
+
+	connection, err := createConnection(flag.Arg(0), *optUser, *optPassword)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Can't connect to host: %s", err.Error())
+		os.Exit(1)
+	}
+	defer connection.Close()
+
+	err = deployFile(connection, flag.Arg(1), path.Base(flag.Arg(1)), "0755")
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Can't deploy file: %s", err.Error())
+		os.Exit(1)
+	}
+
+	session, err := startGDB(connection, "./"+path.Base(flag.Arg(1)))
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Can't start gdb: %s", err.Error())
+		os.Exit(1)
+	}
+	defer session.Close()
+}
+
+func startGDB(client *ssh.Client, remoteCommand string) (*ssh.Session, error) {
+	session, err := client.NewSession()
+	if err != nil {
+		return nil, err
+	}
+
+	output, err := session.StderrPipe()
+	if err != nil {
+		return nil, err
+	}
+
+	err = session.Start("exec nohup gdbserver --once :" + strconv.Itoa(int(*optGdbPort)) + " " + remoteCommand)
+	if err != nil {
+		return nil, err
+	}
+
+	reader := bufio.NewReader(output)
+
+	for line, err := reader.ReadString('\n'); err == nil; line, err = reader.ReadString('\n') {
+		if strings.HasPrefix(line, "Listening on port") {
+			println(line)
+			break
+		}
+	}
+
+	return session, nil
+}
+
+func deployFile(client *ssh.Client, localPath, remotePath string, permissions string) error {
+	reader, err := os.Open(localPath)
+	if err != nil {
+		return err
+	}
+	defer reader.Close()
+
+	st, err := reader.Stat()
+	if err != nil {
+		return err
+	}
+
+	session, err := client.NewSession()
+	if err != nil {
+		return err
+	}
+	defer session.Close()
+
+	writer, _ := session.StdinPipe()
+
+	go func() {
+		fmt.Fprintf(writer, "C%s %d %s\n", permissions, st.Size(), path.Base(remotePath))
+		io.Copy(writer, reader)
+		writer.Write([]byte{0x00})
+		writer.Close()
+	}()
+
+	return session.Run("/usr/bin/scp -t " + path.Dir(remotePath))
+}
+
+func createConnection(host string, username string, password string) (*ssh.Client, error) {
+	config := &ssh.ClientConfig{
+		User: username,
+		Auth: []ssh.AuthMethod{
+			ssh.Password(password),
+		},
+		HostKeyCallback: ssh.InsecureIgnoreHostKey(),
+	}
+
+	return ssh.Dial("tcp", host, config)
+}