--- /dev/null
+/*
+ * Unix: wrapper for getsockopt(SO_PEERCRED), conditionalised on
+ * appropriate autoconfery.
+ */
+
+#ifdef HAVE_CONFIG_H
+# include "uxconfig.h" /* leading space prevents mkfiles.pl trying to follow */
+#endif
+
+#ifdef HAVE_SO_PEERCRED
+#define _GNU_SOURCE
+#include <features.h>
+#endif
+
+#include <sys/socket.h>
+
+#include "putty.h"
+
+int so_peercred(int fd, int *pid, int *uid, int *gid)
+{
+#ifdef HAVE_SO_PEERCRED
+ struct ucred cr;
+ socklen_t crlen = sizeof(cr);
+ if (getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &cr, &crlen) == 0) {
+ *pid = cr.pid;
+ *uid = cr.uid;
+ *gid = cr.gid;
+ return TRUE;
+ }
+#endif
+ return FALSE;
+}