v1.0.0

internal/ssh/args.go

@@ -0,0 +1,76 @@
+// Package ssh builds and runs SSH port-forwarding commands.
+package ssh
+
+import (
+	"errors"
+	"fmt"
+
+	"git.scuroneko.dev/ScuroNeko/est/internal/config"
+)
+
+func buildRemoteToLocalString(sourceIP, remoteIP string, sourcePort, remotePort uint16) string {
+	if sourceIP == "" {
+		sourceIP = "127.0.0.1"
+	}
+	if remoteIP == "" {
+		remoteIP = "127.0.0.1"
+	}
+	return fmt.Sprintf("%s:%d:%s:%d", sourceIP, sourcePort, remoteIP, remotePort)
+}
+func buildLocalToRemoteString(sourceIP, remoteIP string, sourcePort, remotePort uint16) string {
+	if sourceIP == "" {
+		sourceIP = "127.0.0.1"
+	}
+	if remoteIP == "" {
+		remoteIP = "127.0.0.1"
+	}
+	return fmt.Sprintf("%s:%d:%s:%d", remoteIP, remotePort, sourceIP, sourcePort)
+}
+
+var (
+	// ErrEmptyHost is returned when a tunnel has no SSH destination.
+	ErrEmptyHost = errors.New("empty host")
+	// ErrEmptyLocalPort is returned when a tunnel has no local port.
+	ErrEmptyLocalPort = errors.New("empty local port")
+	// ErrEmptyRemotePort is returned when a tunnel has no remote port.
+	ErrEmptyRemotePort = errors.New("empty remote port")
+)
+
+func validateArgs(entry config.ProxyEntry) error {
+	if entry.Host == "" {
+		return ErrEmptyHost
+	}
+	if entry.LocalPort == 0 {
+		return ErrEmptyLocalPort
+	}
+	if entry.RemotePort == 0 {
+		return ErrEmptyRemotePort
+	}
+	return nil
+}
+func prepareArgs(configPath string, entry config.ProxyEntry) ([]string, error) {
+	if err := validateArgs(entry); err != nil {
+		return nil, err
+	}
+	args := []string{"-N", "-T", "-o", "ExitOnForwardFailure=yes"}
+	if configPath != "" {
+		args = append(args, "-F", configPath)
+	} else if configPath = getConfigOrEmpty(); configPath != "" {
+		args = append(args, "-F", configPath)
+	}
+	if entry.IdentityFile != "" {
+		args = append(args, "-i", entry.IdentityFile)
+	}
+	switch entry.Direction {
+	case config.LocalToRemote:
+		args = append(args, "-R", buildLocalToRemoteString(entry.LocalIP, entry.RemoteIP, entry.LocalPort, entry.RemotePort))
+	case config.RemoteToLocal:
+		args = append(args, "-L", buildRemoteToLocalString(entry.LocalIP, entry.RemoteIP, entry.LocalPort, entry.RemotePort))
+	default:
+		return nil, fmt.Errorf("invalid direction: %v; should be ltr on rtl", entry.Direction)
+	}
+	if entry.Host != "" {
+		args = append(args, entry.Host)
+	}
+	return args, nil
+}