dhcp: support endianness independent dhcp_identifier_set_iaid()

The previous code did htole64() followed by unaligned_write_be32() (the
XOR and shift in between is endianness agnostic). That means, on every
architeture there is always exactly one byte swap and the iaid is
dependent on endianness.

Since dhcp_identifier_set_iaid() is part of the DUID generation
algorithm, this cannot be fixed without changing the client-id.
In particular, as the client-id already depends on the machine-id (and
is thus inherrently host-specific), it is better to stick to the current
behavior.

However, add a parameter to switch between old and new behaviour.
Since the new behavior is unused, the only real purpose of this
change is to self-document the oddity of the function.

Fixes: 933f9caeeb2b3c1b951d330e04beb04226e5a890

1 files changed, 1 insertions, 1 deletions

diff --git a/src/libsystemd-network/dhcp-identifier.h b/src/libsystemd-network/dhcp-identifier.h
index 64315d3a3b..a544f38ab8 100644
--- a/src/libsystemd-network/dhcp-identifier.h
+++ b/src/libsystemd-network/dhcp-identifier.h
@@ -57,4 +57,4 @@ int dhcp_identifier_set_duid_llt(struct duid *duid, usec_t t, const uint8_t *add
 int dhcp_identifier_set_duid_ll(struct duid *duid, const uint8_t *addr, size_t addr_len, uint16_t arp_type, size_t *len);
 int dhcp_identifier_set_duid_en(struct duid *duid, size_t *len);
 int dhcp_identifier_set_duid_uuid(struct duid *duid, size_t *len);
-int dhcp_identifier_set_iaid(int ifindex, uint8_t *mac, size_t mac_len, void *_id);
+int dhcp_identifier_set_iaid(int ifindex, const uint8_t *mac, size_t mac_len, bool legacy_unstable_byteorder, void *_id);