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-rw-r--r--lib/lib.c23
-rwxr-xr-xtests/uuidgen.test7
-rw-r--r--toys/pending/uuidgen.c25
3 files changed, 40 insertions, 15 deletions
diff --git a/lib/lib.c b/lib/lib.c
index 8c46678f..3bfe7fc4 100644
--- a/lib/lib.c
+++ b/lib/lib.c
@@ -1138,29 +1138,22 @@ int qstrcmp(const void *a, const void *b)
return strcmp(*(char **)a, *(char **)b);
}
-// According to http://www.opengroup.org/onlinepubs/9629399/apdxa.htm
-// we should generate a uuid structure by reading a clock with 100 nanosecond
-// precision, normalizing it to the start of the gregorian calendar in 1582,
-// and looking up our eth0 mac address.
-//
-// On the other hand, we have 128 bits to come up with a unique identifier, of
-// which 6 have a defined value. /dev/urandom it is.
-
+// See https://tools.ietf.org/html/rfc4122, specifically section 4.4
+// "Algorithms for Creating a UUID from Truly Random or Pseudo-Random
+// Numbers".
void create_uuid(char *uuid)
{
- // Read 128 random bits
+ // "Set all the ... bits to randomly (or pseudo-randomly) chosen values".
int fd = xopenro("/dev/urandom");
xreadall(fd, uuid, 16);
close(fd);
- // Claim to be a DCE format UUID.
+ // "Set the four most significant bits ... of the time_hi_and_version
+ // field to the 4-bit version number [4]".
uuid[6] = (uuid[6] & 0x0F) | 0x40;
+ // "Set the two most significant bits (bits 6 and 7) of
+ // clock_seq_hi_and_reserved to zero and one, respectively".
uuid[8] = (uuid[8] & 0x3F) | 0x80;
-
- // rfc2518 section 6.4.1 suggests if we're not using a macaddr, we should
- // set bit 1 of the node ID, which is the mac multicast bit. This means we
- // should never collide with anybody actually using a macaddr.
- uuid[11] |= 128;
}
char *show_uuid(char *uuid)
diff --git a/tests/uuidgen.test b/tests/uuidgen.test
new file mode 100755
index 00000000..2042a4b9
--- /dev/null
+++ b/tests/uuidgen.test
@@ -0,0 +1,7 @@
+#!/bin/bash
+
+[ -f testing.sh ] && . testing.sh
+
+#testing "name" "command" "result" "infile" "stdin"
+
+testing "smoke" "uuidgen | grep -Eq '[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}' && echo okay" "okay\n" "" ""
diff --git a/toys/pending/uuidgen.c b/toys/pending/uuidgen.c
new file mode 100644
index 00000000..682dec4c
--- /dev/null
+++ b/toys/pending/uuidgen.c
@@ -0,0 +1,25 @@
+/* uuidgen.c - Create a new random UUID
+ *
+ * Copyright 2018 The Android Open Source Project
+ *
+ * UUID RFC: https://tools.ietf.org/html/rfc4122
+
+USE_UUIDGEN(NEWTOY(uuidgen, ">0r(random)", TOYFLAG_USR|TOYFLAG_BIN))
+
+config UUIDGEN
+ bool "uuidgen"
+ default n
+ help
+ usage: uuidgen
+
+ Create and print a new RFC4122 random UUID.
+*/
+
+#define FOR_uuidgen
+#include "toys.h"
+
+void uuidgen_main(void)
+{
+ create_uuid(toybuf);
+ puts(show_uuid(toybuf));
+}