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 patch add support to enables to send User Class option code 77
RFC 3004.
This option MAY carry multiple User Classes.
The format of this option is as follows:
Code Len Value
+-----+-----+--------------------- . . . --+
| 77 | N | User Class Data ('Len' octets) |
+-----+-----+--------------------- . . . --+
where Value consists of one or more instances of User Class Data.
Each instance of User Class Data is formatted as follows:
UC_Len_i User_Class_Data_i
+--------+------------------------ . . . --+
| L_i | Opaque-Data ('UC_Len_i' octets) |
+--------+------------------------ . . . --+
UserClass=
A DHCPv4 client can use UserClass option to identify the type or category of user or applications
it represents. The information contained in this option is an string that represents the user class
of which the client is a member. Each class sets an identifying string of information to be used by the DHCP service to classify clients. Takes a whitespace-separated list.
UserClass= hello world how are you
Closes: RFC: #5134
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.
This makes users can configure DHCPv4 client with ClientIdentifier=duid-only.
If set so, then DHCP client sends only DUID as the client identifier.
This may not be RFC compliant, but some setups require this.
Closes#7828.
Technically DNS allows any ASCII character to be used in the
domain name. Also the DHCP specification for the FQDN option
(RFC 4702) does not put restriction on labels.
However, hostnames do have stricter requirements and typically
should only use characters from a-z (case insensitve), 0-9 and
minus.
Currently we require hostname/FQDN to be either a hostname or
a valid DNS name. Since dns_name_is_valid() allows any ASCII
characters this allows to specify hostnames which are typically
not valid.
Check hostname/FQDN more strictly and require them to pass both
tests. Specifically this requires the entire FQDN to be below 63.
All those uses were correct, but I think it's better to be explicit.
Using implicit errno is too error prone, and with this change we can require
(in the sense of a style guideline) that the code is always specified.
Helpful query: git grep -n -P 'log_[^s][a-z]+\(.*%m'
This changes the return value a bit: 1 will be returned if the value is
changed. But the return value was not documented, and the change should
be for the good anyway. Current callers don't care.
assert_return() should only be used to validate user-facing parameters and
state, assert() should be used for checking our own internal state and
parameters.
A field "index" is not particularly precise and also might conflict with libc's
index() function definition. Also, pretty much everywhere else we call this
concept "ifindex", including in networkd, the primary user of these libraries.
Hence, let's fix this up and call this "ifindex" everywhere here too.
According to recv(2) these should be the same, but that is not true.
Passing a buffer of length 0 to read is defined to be a noop according
to read(2), but passing a buffer of length 0 to recv will discard the
pending pacet.
We can easily hit this as we allocate our buffer size depending on
the size of the incoming packet (using FIONREAD). As pointed out in
issue #3299 simply sending an empty UDP packet to the DHCP client
port will trigger a busy loop in networkd as we are polling on the
socket but never discarding the empty packet.
This reverts ad5ae47a0d but fixes the
same issue.
Both versions of the code are changed to allow the caller to override
DUID using simple rules: duid type and value may be specified, in
which case the caller is responsible to providing the contents,
or just duid type may be specified as DUID_TYPE_EN, in which case we
we fill in the values. In the future more support for other types may
be added, e.g. DUID_TYPE_LLT.
There still remains and ugly discrepancy between dhcp4 and dhcp6 code:
dhcp6 has sd_dhcp6_client_set_duid and sd_dhcp6_client_set_iaid and
requires client->state to be DHCP6_STATE_STOPPED, while dhcp4 has
sd_dhcp_client_set_iaid_duid and will reconfigure the client if it
is not stopped. This commit doesn't touch that part.
This addresses #3127 § 2.
Initialize auto variables with cleanup attribute, otherwise we
get a compiler warning with -fexceptions.
./configure CFLAGS='-Wmaybe-uninitialized -fexceptions -O2'
The server might answer to a DHCPREQUEST with a NAK and currently the
client restarts the configuration process immediately. It was
observed that this can easily generate loops in which the network is
flooded with DISCOVER,OFFER,REQUEST,NAK sequences.
RFC 2131 only states that "if the client receives a DHCPNAK message,
the client restarts the configuration process" without further
details.
Add a delay with exponential backoff between retries after NAKs to
limit the number of requests and cap the delay to 30 minutes.
