[experimental-ims] 939d229 Seed random() on startup from /dev/urandom so vtmpfile actually returns random file names

[Geoff Simmons]

commit 939d2299c51c8af03b663185b79c49e3d7833d86
Author: Martin Blix Grydeland <martin at varnish-software.com>
Date:   Fri Jun 10 09:43:48 2011 +0200

    Seed random() on startup from /dev/urandom so vtmpfile actually
    returns random file names

diff --git a/bin/varnishd/varnishd.c b/bin/varnishd/varnishd.c
index 9dae7d3..ded54ae 100644
--- a/bin/varnishd/varnishd.c
+++ b/bin/varnishd/varnishd.c
@@ -364,6 +364,8 @@ main(int argc, char * const *argv)
 	for (o = getdtablesize(); o > STDERR_FILENO; o--)
 		(void)close(o);
 
+	AZ(seed_random());
+
 	mgt_got_fd(STDERR_FILENO);
 
 	setbuf(stdout, NULL);
diff --git a/include/libvarnish.h b/include/libvarnish.h
index afa9f2f..317dc9e 100644
--- a/include/libvarnish.h
+++ b/include/libvarnish.h
@@ -99,6 +99,7 @@ struct timeval TIM_timeval(double t);
 void VCS_Message(const char *);
 
 /* from libvarnish/vtmpfile.c */
+int seed_random(void);
 int vtmpfile(char *);
 char *vreadfile(const char *pfx, const char *fn, ssize_t *sz);
 char *vreadfd(int fd, ssize_t *sz);
diff --git a/lib/libvarnish/vtmpfile.c b/lib/libvarnish/vtmpfile.c
index 63dde2d..60a9c21 100644
--- a/lib/libvarnish/vtmpfile.c
+++ b/lib/libvarnish/vtmpfile.c
@@ -41,6 +41,22 @@
 #include "libvarnish.h"
 
 int
+seed_random(void)
+{
+	int fd;
+	unsigned seed;
+
+	fd = open("/dev/urandom", O_RDONLY);
+	if (fd == -1)
+		return (1);
+	if (read(fd, &seed, sizeof seed) != sizeof seed)
+		return (1);
+	(void)close(fd);
+	srandom(seed);
+	return (0);
+}
+
+int
 vtmpfile(char *template)
 {
 	char *b, *e, *p;