```
21.16. Vendor Class Option
This option is used by a client to identify the vendor that
manufactured the hardware on which the client is running. The
information contained in the data area of this option is contained in
one or more opaque fields that identify details of the hardware
configuration. The format of the Vendor Class 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_CLASS | option-len |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| enterprise-number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. vendor-class-data .
. . . . .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 28: Vendor Class Option Format
option-code OPTION_VENDOR_CLASS (16).
option-len 4 + length of vendor-class-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-class-data The hardware configuration of the node on
which the client is running. A
variable-length field (4 octets less than the
value in the option-len field).
The vendor-class-data field is composed of a series of separate
items, each of which describes some characteristic of the client's
hardware configuration. Examples of vendor-class-data instances
might include the version of the operating system the client is
running or the amount of memory installed on the client.
Each instance of vendor-class-data is formatted as follows:
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-...-+-+-+-+-+-+-+
| vendor-class-len | opaque-data |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-...-+-+-+-+-+-+-+
Figure 29: Format of vendor-class-data Field
The vendor-class-len field is 2 octets long and specifies the length
of the opaque vendor-class-data in network byte order.
Servers and clients MUST NOT include more than one instance of
OPTION_VENDOR_CLASS with the same Enterprise Number. Each instance
of OPTION_VENDOR_CLASS can carry multiple vendor-class-data
instances.
```
This reflect its role better.
(I didn't use …_persistent_name(), because which name is actually used
depends on the policy. So it's better not to make this sound like it returns
*the* persistent name.)
There are various functions to set the DUID of a DHCPv6 client.
However, none of them allows to set arbitrary data. The closest is
sd_dhcp6_client_set_duid(), which would still do validation of the
DUID's content via dhcp_validate_duid_len().
Relax the validation and only log a debug message if the DUID
does not validate.
Note that dhcp_validate_duid_len() already is not very strict. For example
with DUID_TYPE_LLT it only ensures that the length is suitable to contain
hwtype and time. It does not further check that the length of hwaddr is non-zero
or suitable for hwtype. Also, non-well-known DUID types are accepted for
extensibility. Why reject certain DUIDs but allowing clearly wrong formats
otherwise?
The validation and failure should happen earlier, when accepting the
unsuitable DUID. At that point, there is more context of what is wrong,
and a better failure reason (or warning) can be reported to the user. Rejecting
the DUID when setting up the DHCPv6 client seems not optimal, in particular
because the DHCPv6 client does not care about actual content of the
DUID and treats it as opaque blob.
Also, NetworkManager (which uses this code) allows to configure the entire
binary DUID in binary. It intentionally does not validate the binary
content any further. Hence, it needs to be able to set _invalid_ DUIDs,
provided that some basic constraints are satisfied (like the maximum length).
sd_dhcp6_client_set_duid() has two callers: both set the DUID obtained
from link_get_duid(), which comes from configuration.
`man networkd.conf` says: "The configured DHCP DUID should conform to
the specification in RFC 3315, RFC 6355.". It does not not state that
it MUST conform.
Note that dhcp_validate_duid_len() has another caller: DHCPv4's
dhcp_client_set_iaid_duid_internal(). In this case, continue with
strict validation, as the callers are more controlled. Also, there is
already sd_dhcp_client_set_client_id() which can be used to bypass
this check and set arbitrary client identifiers.
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: 933f9caeeb
This part of the copyright blurb stems from the GPL use recommendations:
https://www.gnu.org/licenses/gpl-howto.en.html
The concept appears to originate in times where version control was per
file, instead of per tree, and was a way to glue the files together.
Ultimately, we nowadays don't live in that world anymore, and this
information is entirely useless anyway, as people are very welcome to
copy these files into any projects they like, and they shouldn't have to
change bits that are part of our copyright header for that.
hence, let's just get rid of this old cruft, and shorten our codebase a
bit.
This drops a good number of type-specific _cleanup_ macros, and patches
all users to just use the generic ones.
In most recent code we abstained from defining type-specific macros, and
this basically removes all those added already, with the exception of
the really low-level ones.
Having explicit macros for this is not too useful, as the expression
without the extra macro is generally just 2ch wider. We should generally
emphesize generic code, unless there are really good reasons for
specific code, hence let's follow this in this case too.
Note that _cleanup_free_ and similar really low-level, libc'ish, Linux
API'ish macros continue to be defined, only the really high-level OO
ones are dropped. From now on this should really be the rule: for really
low-level stuff, such as memory allocation, fd handling and so one, go
ahead and define explicit per-type macros, but for high-level, specific
program code, just use the generic _cleanup_() macro directly, in order
to keep things simple and as readable as possible for the uninitiated.
Note that before this patch some of the APIs (notable libudev ones) were
already used with the high-level macros at some places and with the
generic _cleanup_ macro at others. With this patch we hence unify on the
latter.
Files which are installed as-is (any .service and other unit files, .conf
files, .policy files, etc), are left as is. My assumption is that SPDX
identifiers are not yet that well known, so it's better to retain the
extended header to avoid any doubt.
I also kept any copyright lines. We can probably remove them, but it'd nice to
obtain explicit acks from all involved authors before doing that.
After all it is used in more than one place and is not that short.
Also tweak the test a bit:
- do not check that duid_len > 0, because we want to allow unknown
duid types, and there might be some which are fine with 0 length data,
(also assert should not be called from library code),
- always check that duid_len <= MAX_DUID_LEN, because we could overwrite
available buffer space otherwise.
Rather than passing a pointer to return the result, return it directly
from the function calls.
Also, return the result in native endianess, and let the callers care
about the conversion. For hash tables and bloom filters, we don't care,
but in order to keep MAC addresses and DHCP client IDs stable, we
explicitly convert to LE.
Change the "out" parameter from uint8_t[8] to uint64_t. On architectures which
enforce pointer alignment this fixes crashes when we previously cast an
unaligned array to uint64_t*, and on others this should at least improve
performance as the compiler now aligns these properly.
This also simplifies the code in most cases by getting rid of typecasts. The
only place which we can't change is struct duid's en.id, as that is _packed_
and public API, so we can't enforce alignment of the "id" field and have to
use memcpy instead.
There are more than enough calls doing string manipulations to deserve
its own files, hence do something about it.
This patch also sorts the #include blocks of all files that needed to be
updated, according to the sorting suggestions from CODING_STYLE. Since
pretty much every file needs our string manipulation functions this
effectively means that most files have sorted #include blocks now.
Also touches a few unrelated include files.
Introduce a proper enum, and don't pass around string ids anymore. This
simplifies things quite a bit, and makes virtualization detection more
similar to architecture detection.
This patch removes includes that are not used. The removals were found with
include-what-you-use which checks if any of the symbols from a header is
in use.
