From: Theodore Ts'o <tytso@mit.edu>
Date: Mon, 12 Jun 2000 17:35:13 +0000 (+0000)
Subject: ChangeLog, gen_uuid.c:
X-Git-Tag: E2FSPROGS-1_19~26
X-Git-Url: https://git.whamcloud.com/?a=commitdiff_plain;h=5dd7ff07d032df32b018c0dfd1cbdf30bd7bf29f;p=tools%2Fe2fsprogs.git

ChangeLog, gen_uuid.c:
  gen_uuid.c (get_random_bytes): Use O_NONBLOCK when trying to open
  	/dev/random.  Break out the /dev/random initialization code into a
  	get_random_fd() function, and use that function in uuid_generate() to
  	determine whether to use uuid_generate_random() or
  	uuid_generate_time().
---

diff --git a/lib/uuid/ChangeLog b/lib/uuid/ChangeLog
index 6491656..b20ac32 100644
--- a/lib/uuid/ChangeLog
+++ b/lib/uuid/ChangeLog
@@ -1,3 +1,11 @@
+2000-06-12  Theodore Ts'o  <tytso@valinux.com>
+
+	* gen_uuid.c (get_random_bytes): Use O_NONBLOCK when trying to
+		open /dev/random.  Break out the /dev/random
+		initialization code into a get_random_fd() function, and
+		use that function in uuid_generate() to determine whether
+		to use uuid_generate_random()  or uuid_generate_time().
+
 2000-05-25    <tytso@snap.thunk.org>
 
 	* Makefile: Add hack dependency rule so that parallel makes work
diff --git a/lib/uuid/gen_uuid.c b/lib/uuid/gen_uuid.c
index 5fbb300..be1dbbb 100644
--- a/lib/uuid/gen_uuid.c
+++ b/lib/uuid/gen_uuid.c
@@ -41,23 +41,34 @@
 #define rand() 		random()
 #endif
 
+static int get_random_fd()
+{
+	static int fd = -2;
+	int	i;
+
+	if (fd == -2) {
+		fd = open("/dev/urandom", O_RDONLY);
+		if (fd == -1)
+			fd = open("/dev/random", O_RDONLY | O_NONBLOCK);
+		srand((getpid() << 16) ^ getuid() ^ time(0));
+	}
+	/* Crank the random number generator a few times */
+	for (i = time(0) & 0x1F; i > 0; i--)
+		rand();
+	return fd;
+}
+
+
 /*
  * Generate a series of random bytes.  Use /dev/urandom if possible,
  * and if not, use srandom/random.
  */
 static void get_random_bytes(void *buf, int nbytes)
 {
-	static int fd = -2;
-	int i;
+	int i, fd = get_random_fd();
 	int lose_counter = 0;
 	char *cp = (char *) buf;
 
-	if (fd == -2) {
-		fd = open("/dev/urandom", O_RDONLY);
-		if (fd == -1)
-			fd = open("/dev/random", O_RDONLY);
-		srand((getpid() << 16) ^ getuid() ^ time(0));
-	}
 	if (fd >= 0) {
 		while (nbytes > 0) {
 			i = read(fd, cp, nbytes);
@@ -252,15 +263,7 @@ void uuid_generate_random(uuid_t out)
  */
 void uuid_generate(uuid_t out)
 {
-	static int	has_random = -1;
-
-	if (has_random < 0) {
-		if (access("/dev/urandom", R_OK) == 0)
-			has_random = 1;
-		else
-			has_random = 0;
-	}
-	if (has_random)
+	if (get_random_fd() >= 0)
 		uuid_generate_random(out);
 	else
 		uuid_generate_time(out);