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| author | Lennart Poettering <lennart@poettering.net> | 2021-06-15 17:55:17 +0200 |
|---|---|---|
| committer | Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl> | 2021-06-15 20:58:56 +0200 |
| commit | 39d02a175f08c8cc9e4507e1abce26912d00fac3 (patch) | |
| tree | ccdc51852d56613ef11bdc2c3a999656e35189b4 /man/machine-id.xml | |
| parent | 9b682672e4b21e6325b48da3dcca4b4a479378a6 (diff) | |
| download | systemd-39d02a175f08c8cc9e4507e1abce26912d00fac3.tar.gz | |
sd-id128: document everywhere that we treat all UUIDs as Variant 1
So in theory UUID Variant 2 (i.e. microsoft GUIDs) are supposed to be
displayed in native endian. That is of course a bad idea, and Linux
userspace generally didn't implement that, i.e. uuidd and similar.
Hence, let's not bother either, but let's document that we treat
everything the same as Variant 1, even if it declares something else.
Diffstat (limited to 'man/machine-id.xml')
| -rw-r--r-- | man/machine-id.xml | 16 |
1 files changed, 7 insertions, 9 deletions
diff --git a/man/machine-id.xml b/man/machine-id.xml index f61634fde5..d5d3a1a299 100644 --- a/man/machine-id.xml +++ b/man/machine-id.xml @@ -147,15 +147,13 @@ <refsect1> <title>Relation to OSF UUIDs</title> - <para>Note that the machine ID historically is not an OSF UUID as - defined by <ulink url="https://tools.ietf.org/html/rfc4122">RFC - 4122</ulink>, nor a Microsoft GUID; however, starting with systemd - v30, newly generated machine IDs do qualify as v4 UUIDs.</para> - - <para>In order to maintain compatibility with existing - installations, an application requiring a UUID should decode the - machine ID, and then apply the following operations to turn it - into a valid OSF v4 UUID. With <literal>id</literal> being an + <para>Note that the machine ID historically is not an OSF UUID as defined by <ulink + url="https://tools.ietf.org/html/rfc4122">RFC 4122</ulink>, nor a Microsoft GUID; however, starting with + systemd v30, newly generated machine IDs do qualify as Variant 1 Version 4 UUIDs, as per RFC 4122.</para> + + <para>In order to maintain compatibility with existing installations, an application requiring a strictly + RFC 4122 compliant UUID should decode the machine ID, and then (non-reversibly) apply the following + operations to turn it into a valid RFC 4122 Variant 1 Version 4 UUID. With <literal>id</literal> being an unsigned character array:</para> <programlisting>/* Set UUID version to 4 --- truly random generation */ |