diff --git a/log.c b/log.c
new file mode 100644
index 0000000..3e840ec
--- /dev/null
+++ b/log.c
@@ -0,0 +1,135 @@
+/*
+
+Shared versions of debug(), log(), etc.
+
+*/
+
+#include "includes.h"
+RCSID("$OpenBSD: log.c,v 1.1 1999/11/10 23:36:44 markus Exp $");
+
+#include "ssh.h"
+#include "xmalloc.h"
+
+/* Fatal messages.  This function never returns. */
+
+void
+fatal(const char *fmt, ...)
+{
+  va_list args;
+  va_start(args, fmt);
+  do_log(SYSLOG_LEVEL_FATAL, fmt, args);
+  va_end(args);
+  fatal_cleanup();
+}
+
+/* Error messages that should be logged. */
+
+void
+error(const char *fmt, ...)
+{
+  va_list args;
+  va_start(args, fmt);
+  do_log(SYSLOG_LEVEL_ERROR, fmt, args);
+  va_end(args);
+}
+
+/* Log this message (information that usually should go to the log). */
+
+void
+log(const char *fmt, ...)
+{
+  va_list args;
+  va_start(args, fmt);
+  do_log(SYSLOG_LEVEL_INFO, fmt, args);
+  va_end(args);
+}
+
+/* More detailed messages (information that does not need to go to the log). */
+
+void
+chat(const char *fmt, ...)
+{
+  va_list args;
+  va_start(args, fmt);
+  do_log(SYSLOG_LEVEL_CHAT, fmt, args);
+  va_end(args);
+}
+
+/* Debugging messages that should not be logged during normal operation. */
+
+void
+debug(const char *fmt, ...)
+{
+  va_list args;
+  va_start(args, fmt);
+  do_log(SYSLOG_LEVEL_DEBUG, fmt, args);
+  va_end(args);
+}
+
+/* Fatal cleanup */
+
+struct fatal_cleanup
+{
+  struct fatal_cleanup *next;
+  void (*proc)(void *);
+  void *context;
+};
+
+static struct fatal_cleanup *fatal_cleanups = NULL;
+
+/* Registers a cleanup function to be called by fatal() before exiting. */
+
+void
+fatal_add_cleanup(void (*proc)(void *), void *context)
+{
+  struct fatal_cleanup *cu;
+
+  cu = xmalloc(sizeof(*cu));
+  cu->proc = proc;
+  cu->context = context;
+  cu->next = fatal_cleanups;
+  fatal_cleanups = cu;
+}
+
+/* Removes a cleanup frunction to be called at fatal(). */
+
+void
+fatal_remove_cleanup(void (*proc)(void *context), void *context)
+{
+  struct fatal_cleanup **cup, *cu;
+  
+  for (cup = &fatal_cleanups; *cup; cup = &cu->next)
+    {
+      cu = *cup;
+      if (cu->proc == proc && cu->context == context)
+	{
+	  *cup = cu->next;
+	  xfree(cu);
+	  return;
+	}
+    }
+  fatal("fatal_remove_cleanup: no such cleanup function: 0x%lx 0x%lx\n",
+	(unsigned long)proc, (unsigned long)context);
+}
+
+/* Cleanup and exit */
+void
+fatal_cleanup(void)
+{
+  struct fatal_cleanup *cu, *next_cu;
+  static int called = 0;
+  if (called)
+    exit(255);
+  called = 1;
+
+  /* Call cleanup functions. */
+  for (cu = fatal_cleanups; cu; cu = next_cu)
+    {
+      next_cu = cu->next;
+      debug("Calling cleanup 0x%lx(0x%lx)",
+	    (unsigned long)cu->proc, (unsigned long)cu->context);
+      (*cu->proc)(cu->context);
+    }
+
+  exit(255);
+}