To make sure everything still compiles, we add a preliminary include
of forward.h to tests.h to make sure it is included in every test source
file. We'll clean up the tests.h includes in a later commit.
We also add a <errno.h> include to errno-list.h to keep test-errno-list.c
compiling. It'll be removed again when we clean up includes in src/basic.
Split out of #37344.
New directive `NFTSet=` provides a method for integrating dynamic cgroup IDs
into firewall rules with NFT sets. The benefit of using this setting is to be
able to use control group as a selector in firewall rules easily and this in
turn allows more fine grained filtering. Also, NFT rules for cgroup matching
use numeric cgroup IDs, which change every time a service is restarted, making
them hard to use in systemd environment.
This option expects a whitespace separated list of NFT set definitions. Each
definition consists of a colon-separated tuple of source type (only "cgroup"),
NFT address family (one of "arp", "bridge", "inet", "ip", "ip6", or "netdev"),
table name and set name. The names of tables and sets must conform to lexical
restrictions of NFT table names. The type of the element used in the NFT filter
must be "cgroupsv2". When a control group for a unit is realized, the cgroup ID
will be appended to the NFT sets and it will be be removed when the control
group is removed. systemd only inserts elements to (or removes from) the sets,
so the related NFT rules, tables and sets must be prepared elsewhere in
advance. Failures to manage the sets will be ignored.
If the firewall rules are reinstalled so that the contents of NFT sets are
destroyed, command systemctl daemon-reload can be used to refill the sets.
Example:
```
table inet filter {
...
set timesyncd {
type cgroupsv2
}
chain ntp_output {
socket cgroupv2 != @timesyncd counter drop
accept
}
...
}
```
/etc/systemd/system/systemd-timesyncd.service.d/override.conf
```
[Service]
NFTSet=cgroup:inet:filter:timesyncd
```
```
$ sudo nft list set inet filter timesyncd
table inet filter {
set timesyncd {
type cgroupsv2
elements = { "system.slice/systemd-timesyncd.service" }
}
}
```
New directive `NFTSet=` provides a method for integrating network configuration
into firewall rules with NFT sets. The benefit of using this setting is that
static network configuration or dynamically obtained network addresses can be
used in firewall rules with the indirection of NFT set types. For example,
access could be granted for hosts in the local subnetwork only. Firewall rules
using IP address of an interface are also instantly updated when the network
configuration changes, for example via DHCP.
This option expects a whitespace separated list of NFT set definitions. Each
definition consists of a colon-separated tuple of source type (one of
"address", "prefix", or "ifindex"), NFT address family (one of "arp", "bridge",
"inet", "ip", "ip6", or "netdev"), table name and set name. The names of tables
and sets must conform to lexical restrictions of NFT table names. The type of
the element used in the NFT filter must match the type implied by the
directive ("address", "prefix" or "ifindex") and address type (IPv4 or IPv6)
as shown type implied by the directive ("address", "prefix" or "ifindex") and
address type (IPv4 or IPv6) must also match the set definition.
When an interface is configured with IP addresses, the addresses, subnetwork
masks or interface index will be appended to the NFT sets. The information will
be removed when the interface is deconfigured. systemd-networkd only inserts
elements to (or removes from) the sets, so the related NFT rules, tables and
sets must be prepared elsewhere in advance. Failures to manage the sets will be
ignored.
/etc/systemd/network/eth.network
```
[DHCPv4]
...
NFTSet=prefix:netdev:filter:eth_ipv4_prefix
```
Example NFT rules:
```
table netdev filter {
set eth_ipv4_prefix {
type ipv4_addr
flags interval
}
chain eth_ingress {
type filter hook ingress device "eth0" priority filter; policy drop;
ip saddr != @eth_ipv4_prefix drop
accept
}
}
```
```
$ sudo nft list set netdev filter eth_ipv4_prefix
table netdev filter {
set eth_ipv4_prefix {
type ipv4_addr
flags interval
elements = { 10.0.0.0/24 }
}
}
```
This reverts PR #22587 and its follow-up commit. More specifically,
2299b1cae3 (partially),
e176f855278d5098d3fecc5aa24ba702147d42e0,
ceb46a31a01b3d3d1d6095d857e29ea214a2776b, and
51bb9076ab8c050bebb64db5035852385accda35.
The PR was merged without final approval, and has several issues:
- OSS fuzz reported issues in the conf parser,
- It calls synchrnous netlink call, it should not be especially in PID1,
- The importance of NFTSet for CGroup and DynamicUser may be
questionable, at least, there was no justification PID1 should support
it.
- For networkd, it should be implemented with Request object,
- There is no test for the feature.
Fixes#23711.
Fixes#23717.
Fixes#23719.
Fixes#23720.
Fixes#23721.
Fixes#23759.
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 }
}
}
```
Yu Watanabe
Daan De Meyer
Topi Miettinen