The time-based cache allows starting a new unit without an expensive
daemon-reload, unless there was already a reference to it because of
a dependency or ordering from another unit.
If the cache is out of date, check again if we can load the
fragment.
This is an attempt to clean-up the DHCP lease server type code a bit. We
now strictly use the same enum everywhere, and store server info in an
array. Moreover, we use the same nomenclature everywhere.
This only makes the changes in the sd-dhcp code. The networkd code is
untouched so far (but should be fixed up like this too. But it's more
complicated since this would then touch actual settings in .network
files).
Note that this also changes some field names in serialized lease files.
But given that these field names have not been part of a released
version of systemd yet, such a change should be ok.
This is pure renaming/refactoring, shouldn't actually change any
behaviour.
```
=220358== Invalid read of size 8
==220358== at 0x452F05: l2tp_session_free (l2tp-tunnel.c:46)
==220358== by 0x456926: l2tp_tunnel_done (l2tp-tunnel.c:725)
==220358== by 0x43CF4D: netdev_free (netdev.c:205)
==220358== by 0x43D045: netdev_unref (netdev.c:210)
==220358== by 0x4198B7: manager_free (networkd-manager.c:1877)
==220358== by 0x40D0B3: manager_freep (networkd-manager.h:105)
==220358== by 0x40DE1C: run (networkd.c:21)
==220358== by 0x40DE75: main (networkd.c:130)
==220358== Address 0x5c035d0 is 0 bytes inside a block of size 40 free'd
==220358== at 0x483A9F5: free (vg_replace_malloc.c:538)
==220358== by 0x452F87: l2tp_session_free (l2tp-tunnel.c:57)
==220358== by 0x456857: netdev_l2tp_tunnel_verify (l2tp-tunnel.c:710)
==220358== by 0x440947: netdev_load_one (netdev.c:738)
==220358== by 0x441222: netdev_load (netdev.c:851)
==220358== by 0x419C50: manager_load_config (networkd-manager.c:1934)
==220358== by 0x40D7BE: run (networkd.c:87)
==220358== by 0x40DE75: main (networkd.c:130)
==220358== Block was alloc'd at
==220358== at 0x4839809: malloc (vg_replace_malloc.c:307)
==220358== by 0x452A76: malloc_multiply (alloc-util.h:96)
==220358== by 0x4531E6: l2tp_session_new_static (l2tp-tunnel.c:82)
==220358== by 0x455C01: config_parse_l2tp_session_id (l2tp-tunnel.c:535)
==220358== by 0x48E6D72: next_assignment (conf-parser.c:133)
==220358== by 0x48E77A3: parse_line (conf-parser.c:271)
==220358== by 0x48E7E4F: config_parse (conf-parser.c:396)
==220358== by 0x48E80E5: config_parse_many_files (conf-parser.c:453)
==220358== by 0x48E8490: config_parse_many (conf-parser.c:512)
==220358== by 0x44089C: netdev_load_one (netdev.c:729)
==220358== by 0x441222: netdev_load (netdev.c:851)
==220358== by 0x419C50: manager_load_config (networkd-manager.c:1934)
```
"internal" is a lot of characters. Let's take a leaf out of the Python's book
and simply use _ to mean private. Much less verbose, but the meaning is just as
clear, or even more.
This is a safey net anyway, let's make it fully safe: if the data ends
on an uneven byte, then we need to complete the UTF-16 codepoint first,
before adding the final NUL byte pair. Hence let's suffix with three
NULs, instead of just two.
RFC: 8415
21.17. Vendor-specific Information Option
This option is used by clients and servers to exchange vendor-
specific information.
The format of the Vendor-specific Information option is:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| OPTION_VENDOR_OPTS | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| enterprise-number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. vendor-option-data .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 30: Vendor-specific Information Option Format
option-code OPTION_VENDOR_OPTS (17).
option-len 4 + length of vendor-option-data field.
enterprise-number The vendor's registered Enterprise Number as
maintained by IANA [IANA-PEN]. A 4-octet
field containing an unsigned integer.
vendor-option-data Vendor options, interpreted by
vendor-specific code on the clients and
servers. A variable-length field (4 octets
less than the value in the option-len field).
The definition of the information carried in this option is vendor
specific. The vendor is indicated in the enterprise-number field.
Use of vendor-specific information allows enhanced operation,
utilizing additional features in a vendor's DHCP implementation. A
DHCP client that does not receive requested vendor-specific
information will still configure the node's IPv6 stack to be
functional.
The vendor-option-data field MUST be encoded as a sequence of
code/length/value fields of format identical to the DHCP options (see
Section 21.1). The sub-option codes are defined by the vendor
identified in the enterprise-number field and are not managed by
IANA. Each of the sub-options is formatted as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| sub-opt-code | sub-option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. sub-option-data .
. .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 31: Vendor-specific Options Format
sub-opt-code The code for the sub-option. A 2-octet
field.
sub-option-len An unsigned integer giving the length of the
sub-option-data field in this sub-option in
octets. A 2-octet field.
sub-option-data The data area for the sub-option. The
length, in octets, is specified by
sub-option-len.
Multiple instances of the Vendor-specific Information option may
appear in a DHCP message. Each instance of the option is interpreted
according to the option codes defined by the vendor identified by the
Enterprise Number in that option. Servers and clients MUST NOT send
more than one instance of the Vendor-specific Information option with
the same Enterprise Number. Each instance of the Vendor-specific
Information option MAY contain multiple sub-options.
A client that is interested in receiving a Vendor-specific
Information option:
- MUST specify the Vendor-specific Information option in an Option
Request option.
- MAY specify an associated Vendor Class option (see Section 21.16).
- MAY specify the Vendor-specific Information option with
appropriate data.
Servers only return the Vendor-specific Information options if
specified in Option Request options from clients and:
- MAY use the Enterprise Numbers in the associated Vendor Class
options to restrict the set of Enterprise Numbers in the
Vendor-specific Information options returned.
- MAY return all configured Vendor-specific Information options.
- MAY use other information in the packet or in its configuration to
determine which set of Enterprise Numbers in the Vendor-specific
Information options to return.
Hans de Goede