Re: [libvirt] [PATCH v4] npiv: Auto-generate WWN if it's not specified
On 02/03/2012 04:17 AM, Osier Yang wrote:
The auto-generated WWN comply with the new addressing schema of WWN:
<quote>
the first nibble is either hex 5 or 6 followed by a 3-byte vendor
identifier and 36 bits for a vendor-specified serial number.
</quote>
We choose hex 5 for the first nibble. And use Qumranet's OUI
(00:1A:4A) as the 3-byte vendor indentifier. The last 36 bits
are auto-generated.
+++ b/src/libvirt_private.syms
@@ -1374,6 +1374,7 @@ virPidFileDeletePath;
# virrandom.h
virRandomBits;
virRandomInitialize;
+virWWNGenerate;
This should be named with a virRandom prefix; I like
virRandomGenerateWWN
+#define QUMRANET_OUI "001a4a"
+
+int virWWNGenerate(char **wwn) {
Formatting, I would do:
int
virRandomGenerateWWN(char **wwn)
{
+ int suffix[5];
+
+ suffix[0] = virRandomBits(16);
Eep. That's a waste of random bits (generating a uint16_t for just 4 bits).
+ suffix[1] = virRandomBits(256);
And that's a usage error. virRandomBits takes an argument 1-64, not larger.
+ suffix[2] = virRandomBits(256);
+ suffix[3] = virRandomBits(256);
+ suffix[4] = virRandomBits(256);
+
+ if (virAsprintf(wwn, "%x%s%x%02x%02x%02x%02x", 0x5, QUMRANET_OUI,
Why not just:
if (virAsprintf(wwn, "5" QUMRANET_OUI "%010llx",
(unsigned long long) virRandomBits(36)) < 0)
and skip going through a temporary array.
--
Eric Blake eblake(a)redhat.com +1-919-301-3266
Libvirt virtualization library http://libvirt.org
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