Add a simple srandomdev() implementation inspired by the one in FreeBSD.

git-svn-id: http://www.varnish-cache.org/svn/trunk/varnish-cache@766 d4fa192b-c00b-0410-8231-f00ffab90ce4

configure.ac

@@ -61,6 +61,7 @@ AC_FUNC_VPRINTF
 AC_CHECK_FUNCS([strerror])
 AC_FUNC_STRERROR_R
 AC_CHECK_FUNCS([socket])
+AC_CHECK_FUNCS([srandomdev])
 AC_CHECK_FUNCS([strlcat])
 AC_CHECK_FUNCS([strlcpy])
 

include/Makefile.am

@@ -6,6 +6,7 @@ noinst_HEADERS = \
 	cli_common.h \
 	cli_priv.h \
 	compat/asprintf.h \
+	compat/srandomdev.h \
 	compat/strlcat.h \
 	compat/strlcpy.h \
 	compat/vasprintf.h \

include/compat/srandomdev.h

+/*
+ * $Id$
+ */
+
+#ifndef COMPAT_SRANDOMDEV_H_INCLUDED
+#define COMPAT_SRANDOMDEV_H_INCLUDED
+
+#ifndef HAVE_SRANDOMDEV
+void srandomdev(void);
+#endif
+
+#endif

lib/libcompat/Makefile.am

@@ -7,6 +7,7 @@ lib_LIBRARIES = libcompat.a
 libcompat_a_SOURCES = \
 	asprintf.c \
 	vasprintf.c \
+	srandomdev.c \
 	strlcat.c \
 	strlcpy.c
 

lib/libcompat/srandomdev.c

+/*
+ * $Id$
+ */
+
+#ifndef HAVE_SRANDOMDEV
+
+#include <sys/time.h>
+
+#include <fcntl.h>
+#include <stdlib.h>
+#include <time.h>
+#include <unistd.h>
+
+#include "compat/srandomdev.h"
+
+void
+srandomdev(void)
+{
+	struct timeval tv;
+	unsigned int seed;
+	int fd;
+
+	if ((fd = open("/dev/random", O_RDONLY)) >= 0) {
+		read(fd, &seed, sizeof seed);
+		close(fd);
+	} else {
+		gettimeofday(&tv, NULL);
+		/* NOTE: intentional use of uninitialized variable */
+		seed ^= (getpid() << 16) ^ tv.tv_sec ^ tv.tv_usec;
+	}
+	srandom(seed);
+}
+#endif