zte's code,first commit

Change-Id: I9a04da59e459a9bc0d67f101f700d9d7dc8d681b
diff --git a/ap/app/clatd/arc4random.h b/ap/app/clatd/arc4random.h
new file mode 100755
index 0000000..ae76155
--- /dev/null
+++ b/ap/app/clatd/arc4random.h
@@ -0,0 +1,104 @@
+/*	$OpenBSD: arc4random_linux.h,v 1.7 2014/07/20 20:51:13 bcook Exp $	*/
+
+/*
+ * Copyright (c) 1996, David Mazieres <dm@uun.org>
+ * Copyright (c) 2008, Damien Miller <djm@openbsd.org>
+ * Copyright (c) 2013, Markus Friedl <markus@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*
+ * Stub functions for portability.
+ */
+
+#include <errno.h>
+#include <pthread.h>
+#include <signal.h>
+#include <sys/mman.h>
+
+//#include <async_safe/log.h>
+
+//#include "bionic_prctl.h"
+#include <sys/prctl.h>
+
+// This is only supported by Android kernels, so it's not in the uapi headers.
+#define PR_SET_VMA   0x53564d41
+#define PR_SET_VMA_ANON_NAME    0
+
+
+// Android gets these from "thread_private.h".
+//#include "thread_private.h"
+static pthread_mutex_t arc4random_mtx = PTHREAD_MUTEX_INITIALIZER;
+#define _ARC4_LOCK()   pthread_mutex_lock(&arc4random_mtx)
+#define _ARC4_UNLOCK() pthread_mutex_unlock(&arc4random_mtx)
+
+#ifdef __GLIBC__
+extern void *__dso_handle;
+extern int __register_atfork(void (*)(void), void(*)(void), void (*)(void), void *);
+#define _ARC4_ATFORK(f) __register_atfork(NULL, NULL, (f), __dso_handle)
+#else
+#define _ARC4_ATFORK(f) pthread_atfork(NULL, NULL, (f))
+#endif
+
+// Formats a message to the log (priority 'fatal'), then aborts.
+// Implemented as a macro so that async_safe_fatal isn't on the stack when we crash:
+// we appear to go straight from the caller to abort, saving an uninteresting stack
+// frame.
+#define async_safe_fatal(...) \
+  do { \
+    printf(__VA_ARGS__); \
+    abort(); \
+  } while (0) \
+
+static inline void _getentropy_fail(void) {
+    async_safe_fatal("getentropy failed: %s", strerror(errno));
+}
+
+volatile sig_atomic_t _rs_forked;
+
+static inline void
+_rs_forkdetect(void)
+{
+	static pid_t _rs_pid = 0;
+	pid_t pid = getpid();
+
+	if (_rs_pid == 0 || _rs_pid != pid || _rs_forked) {
+		_rs_pid = pid;
+		_rs_forked = 0;
+		if (rs)
+			memset(rs, 0, sizeof(*rs));
+	}
+}
+
+static inline int
+_rs_allocate(struct _rs **rsp, struct _rsx **rsxp)
+{
+	// OpenBSD's arc4random_linux.h allocates two separate mappings, but for
+	// themselves they just allocate both structs into one mapping like this.
+	struct {
+		struct _rs rs;
+		struct _rsx rsx;
+	} *p;
+
+	if ((p = mmap(NULL, sizeof(*p), PROT_READ|PROT_WRITE,
+	    MAP_ANON|MAP_PRIVATE, -1, 0)) == MAP_FAILED)
+		return (-1);
+
+	prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, p, sizeof(*p), "arc4random data");
+
+	*rsp = &p->rs;
+	*rsxp = &p->rsx;
+
+	return (0);
+}