networkd: rework duid_{type,duid_type,duid,duid_len} setting

Separate fields are replaced  with a struct.

Second second duid type field is removed. The first field was used to carry
the result of DUIDType= configuration, and the second was either a copy of
this, or contained the type extracted from DuidRawData. The semantics are changed
so that the type specified in DUIDType is always used. DUIDRawData= no longer
overrides the type setting.

The networkd code is now more constrained than the sd-dhcp code:
DUIDRawData cannot have 0 length, length 0 is treated the same as unsetting.
Likewise, it is not possible to set a DUIDType=0. If it ever becomes necessary
to set type=0 or a zero-length duid, the code can be changed to support that.
Nevertheless, I think that's unlikely.

This addresses #3127 § 1 and 3.

v2:
- rename DUID.duid, DUID.duid_len to DUID.raw_data, DUID.raw_data_len

1 files changed, 8 insertions, 6 deletions

diff --git a/src/network/networkd.h b/src/network/networkd.h
index 39826a440d..26d9e7d6e0 100644
--- a/src/network/networkd.h
+++ b/src/network/networkd.h
@@ -74,14 +74,16 @@ struct Manager {
 
         usec_t network_dirs_ts_usec;
 
-        /* Value of Type in [DUID] section */
-        DUIDType duid_type;
-        /* DUID type code - RFC 3315 */
-        uint16_t dhcp_duid_type;
-        size_t dhcp_duid_len;
-        uint8_t dhcp_duid[MAX_DUID_LEN];
+        DUID duid;
 };
 
+static inline const DUID* link_duid(const Link *link) {
+        if (link->network->duid.type != _DUID_TYPE_INVALID)
+                return &link->network->duid;
+        else
+                return &link->manager->duid;
+}
+
 extern const sd_bus_vtable manager_vtable[];
 
 int manager_new(Manager **ret);