New directives `NFTSet=`, `IPv4NFTSet=` and `IPv6NFTSet=` provide a method for
integrating configuration of dynamic networks into firewall rules with NFT
sets.
/etc/systemd/network/eth.network
```
[DHCPv4]
...
NFTSet=netdev:filter:eth_ipv4_address
```
```
table netdev filter {
set eth_ipv4_address {
type ipv4_addr
flags interval
}
chain eth_ingress {
type filter hook ingress device "eth0" priority filter; policy drop;
ip saddr != @eth_ipv4_address drop
accept
}
}
```
```
sudo nft list set netdev filter eth_ipv4_address
table netdev filter {
set eth_ipv4_address {
type ipv4_addr
flags interval
elements = { 10.0.0.0/24 }
}
}
```
New directive `NetLabel=` provides a method for integrating dynamic network
configuration into Linux NetLabel subsystem rules, used by Linux security
modules (LSMs) for network access control. The option expects a whitespace
separated list of NetLabel labels. The labels must conform to lexical
restrictions of LSM labels. When an interface is configured with IP addresses,
the addresses and subnetwork masks will be appended to the NetLabel Fallback
Peer Labeling rules. They will be removed when the interface is
deconfigured. Failures to manage the labels will be ignored.
Example:
```
[DHCP]
NetLabel=system_u:object_r:localnet_peer_t:s0
```
With the above rules for interface `eth0`, when the interface is configured with
an IPv4 address of 10.0.0.0/8, `systemd-networkd` performs the equivalent of
`netlabelctl` operation
```
$ sudo netlabelctl unlbl add interface eth0 address:10.0.0.0/8 label:system_u:object_r:localnet_peer_t:s0
```
Result:
```
$ sudo netlabelctl -p unlbl list
...
interface: eth0
address: 10.0.0.0/8
label: "system_u:object_r:localnet_peer_t:s0"
...
```
IN6_ADDR_TO_STRING(…) always returns something, so we can simplify the code a
lot. Also, let's not do step-wise concatenation, but instead handle everything
with one str_extendf() call.
Since we don't need the error value, and the buffer is allocated with a fixed
size, the whole logic provided by in_addr_to_string() becomes unnecessary, so
it's enough to wrap inet_ntop() directly.
inet_ntop() can only fail with ENOSPC. But we specify a buffer that is supposed
to be large enough, so this should never fail. A bunch of tests of this are added.
This allows all the wrappers like strna(), strnull(), strempty() to be dropped.
The guard of 'if (DEBUG_LOGGING)' can be dropped from around log_debug(),
because log_debug() implements the check outside of the function call. But
log_link_debug() does not, so it we need it to avoid unnecessary evaluation of
the formatting.
Not sure when the issue was fixed.
- kernel-3.10 on CentOS 7 has the issue,
- kernel-4.18 on CentOS 8 works fine.
Note, the workaround dropped by the commit is not incomplete:
with an old kernel which has the issue, all non-prefix routes are
configured on the specified route table, but the prefix route is
configured on the main table. That should not work for most cases,
hence, the workaround is mostly meaningless.
"left from <something>" is not correct. "left <something>" would be the
usual form, but "left master interface" is not clear at all. So reword
those messages totally.
Follow-up for 3881fd406b.
This fixes a minor bug introduced by 10af8bb24b.
Before the commit, the interface group was set only when Group= is explicitly
specified, otherwise the interface group was kept. However, after the commit,
we need to specify Group= with an empty string to keep the current interface
group.
Without the size limits, oss-fuzz creates huge samples that time out. Usually
this is because some of our code has bad algorithmic complexity. For data like
configuration samples we don't need to care about this: non-rogue configs are
rarely more than a few items, and a bit of a slowdown with a few hundred items
is acceptable. This wouldn't be OK for processing of untrusted data though.
We need to set the limit in two ways: through .options and in the code. The
first because it nicely allows libFuzzer to avoid wasting time, and the second
because fuzzers like hongfuzz and afl don't support .options.
While at it, let's fix an off-by-one (65535 is the largest offset for a
power-of-two size, but we're checking the size here).
Co-authored-by: Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>
In the documentation, using the term "managed" for both the RA flag and
the DHCPv6 mode is confusing because the mode is referred to as
"solicit" both in the official DHCPv6 documentation (see RFC 8415) and
in the WithoutRA option.
Furthermore, calling the other RA flag "other information" or "other
address configuration" is confusing because its official name is simply
"other configuration" (see RFC 4861 and RFC 5175) and it isn't used to
assign IP addresses.
Rewrite the documentation for DHCPv6Client and WithoutRA to make it
clear that getting the "managed" RA flag triggers the same kind of DHCP
request as WithoutRA=solicit, whereas getting the "other configuration"
RA flag triggers the same kind of DHCP request as
WithoutRA=information-request.
This is a high-level function, and it belongs in libsystemd-shared. This way we
don't end up linking a separate copy into various binaries. It would even end
up in libsystemd, where it is not needed. (Maybe it'd be removed in some
optimization phase, but it's better to not rely on that.)
$ grep -l -r -a 'path is not absolute%s' build/
build/libnss_systemd.so.2
build/pam_systemd_home.so
build/test-dlopen
build/src/basic/libbasic.a.p/path-util.c.o
build/src/basic/libbasic.a
build/src/shared/libsystemd-shared-249.so
build/test-bus-error
build/libnss_mymachines.so.2
build/pam_systemd.so
build/libnss_resolve.so.2
build/libnss_myhostname.so.2
build/libsystemd.so.0.32.0
build/libudev.so.1.7.2
$ grep -l -r -a 'path is not absolute%s' build/
build/src/shared/libsystemd-shared-251.a.p/parse-helpers.c.o
build/src/shared/libsystemd-shared-251.a
build/src/shared/libsystemd-shared-251.so
No functional change.
"Link-local" and "link local" are used throughout man pages and program
output, with the former used far more than the latter. This commit makes
it consistent throughout the project.
Currently, there exist only two MTU sources, static and DHCPv4, and they
are exclusive. Hence, it is not necessary to check the existence of the
MTU option in the acquired DHCP lease. Let's unconditionally reset the
MTU. Note that, if the current and original MTU are equivalent, then
link_request_to_set_mtu() handles that gracefully.
The commit 6706ce2fd2 made
IgnoreCarrierLoss= setting also take timespan, to make users handle
issues like #18738 or #20887. But still users needed to explicitly set
a timespan.
This makes networkd automatically determine the timeout when the
situations #18738 or #19832 is detected. Unfortunately, still users have
issue #20887 need to specify a value.
Closes#19832.
Let's raise our supported baseline a bit: CLOCK_BOOTTIME started to work
with timerfd in kernel 3.15 (i.e. back in 2014), let's require support
for it now.
This will raise our baseline only modestly from 3.13 → 3.15.
The commit 1cf4ed142d makes the IPv4 ACD
enabled unconditionally for IPv4 link-local addresses even if users
explicitly disable ACD.
This makes the IPv4 ACD is enabled by default, but honor user setting.
Fixes#22763.
If the prefix is only referenced by sd_radv, then the returned pointer
is already freed.
networkd does not uses the returned value. Let's voidify the function.
This makes Request object takes hash, compare, free, and process functions.
With this change, the logic in networkd-queue.c can be mostly
independent of the type of the request or the object (e.g. Address) assigned
to the request, and it becomes simpler.
The condition should be satisfied only when users request to reconfigure
the link, and in that case, all request will be cancelled. Hence, it is
not necessary to process the request.
In most netlink handlers, we do the following,
1. decrease the message counter,
2. check the link state,
3. error handling,
4. update link state via e.g. link_check_ready().
The first two steps are mostly common, hence let's extract it.
Moreover, this is not only extracting the common logic, but provide a
strong advantage; `request_call_netlink_async()` assigns the relevant
Request object to the userdata of the netlink slot, and the request object
has full information about the message we sent. Hence, in the future,
netlink handler can print more detailed error message. E.g. when
an address is failed to configure, then currently we only show an
address is failed to configure, but with this commit, potentially we can
show which address is failed explicitly.
This does not change such error handling yet. But let's do that later.
Previously, even though all Request object are owned by Manager, they
do not have direct reference to Manager, but through Link or NetDev
object. But, as Link or NetDev can be NULL, we need to conditionalize
how to access Manager from Request with the type of the request.
This makes the way simpler, as now Request object has direct reference
to Manager.
This also rename request_drop() -> request_detach(), as in the previous
commit, the reference counter is introduced, so even if a reference of
a Request object from Manager is dropped, the object may still alive.
The naming `request_drop()` sounds the object will freed by the
function. But it may not. And `request_detach()` suggests the object
will not be managed by Manager any more, and I think it is more
appropreate.
This is just a cleanup, and should not change any behavior.
Yu Watanabe
Topi Miettinen
Zbigniew Jędrzejewski-Szmek
Alex Henrie
Simon Ellmann
Lennart Poettering
Sebastian Pucilowski
Luca Boccassi
Jan Janssen