Use pthread_atfork() and variants to detect fork

1 files changed, 105 insertions, 0 deletions

diff --git a/lib/atfork.c b/lib/atfork.c
new file mode 100644
index 0000000000..c1303d5534
--- /dev/null
+++ b/lib/atfork.c
@@ -0,0 +1,105 @@
+/*
+ * Copyright (C) 2010-2012 Free Software Foundation, Inc.
+ * Copyright (C) 2014 Red Hat
+ *
+ * Author: Nikos Mavrogiannopoulos
+ *
+ * This file is part of GnuTLS.
+ *
+ * The GnuTLS is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * as published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ *
+ */
+
+#include <config.h>
+#include <gnutls_int.h>
+#include <gnutls_errors.h>
+
+#include <sys/socket.h>
+#include <errno.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <atfork.h>
+
+#ifndef _WIN32
+
+# if defined(HAVE___REGISTER_ATFORK) || defined(HAVE_PTHREAD_ATFORK)
+#  define HAVE_ATFORK
+# endif
+
+/* The maximum number of users of the API */
+# define MAX_VALS 6
+
+static unsigned int * fvals[MAX_VALS];
+static unsigned int fvals_size = 0;
+
+# ifdef HAVE_ATFORK
+static void fork_handler(void)
+{
+	unsigned i;
+	for (i=0;i<fvals_size;i++)
+		*fvals[i] = 1;
+}
+# endif
+
+static void set_val_on_fork(unsigned int *val, unsigned int def)
+{
+fprintf(stderr, "fvals: %d\n", fvals_size);
+	if (fvals_size >= MAX_VALS)
+		abort(); /* internal error */
+	*val = def;
+	fvals[fvals_size++] = val;
+}
+
+void _gnutls_fork_set_val(unsigned int *val)
+{
+# ifdef HAVE_ATFORK
+	set_val_on_fork(val, 0);
+# else
+	set_val_on_fork(val, getpid());
+# endif
+}
+
+# if defined(HAVE_PTHREAD_ATFORK)
+
+#  include <pthread.h>
+
+int _gnutls_register_fork_handler(void)
+{
+	if (pthread_atfork(NULL, NULL, fork_handler) != 0)
+		return gnutls_assert_val(GNUTLS_E_INTERNAL_ERROR);
+	return 0;
+}
+
+# elif defined(HAVE___REGISTER_ATFORK)
+extern int __register_atfork(void (*)(void), void(*)(void), void (*)(void), void *);
+extern void *__dso_handle;
+
+int _gnutls_register_fork_handler(void)
+{
+	if (__register_atfork(NULL, NULL, fork_handler, __dso_handle) != 0)
+		return gnutls_assert_val(GNUTLS_E_INTERNAL_ERROR);
+	return 0;
+}
+
+# else
+
+/* we have to detect fork manually */
+int _gnutls_register_fork_handler(void)
+{
+	return 0;
+}
+
+# endif
+
+#endif /* !_WIN32 */