The nft set backend doesn't support network masks, it works with
ranges. Inputs like dead::/64 thus need to be translated to two
'start' and 'end' elements.
The 'start' element is the first element in the range (i.e., dead::).
The 'stop' element is the first element *past* the range, (dead:0:0100::
in the example).
This adds a few test cases.
closely mirrors the existing ipv4 ruleset:
table ip6 io.systemd.nat {
set masq_saddr {
type ipv6_addr
flags interval
}
map map_port_ipport {
type inet_proto . inet_service : ipv6_addr . inet_service
}
chain prerouting {
type nat hook prerouting priority dstnat + 1; policy accept;
fib daddr type local dnat ip6 addr . port to meta l4proto . th dport map @map_port_ipport
}
chain output {
type nat hook output priority -99; policy accept;
ip6 daddr != ::1 oif "lo" dnat ip6 addr . port to meta l4proto . th dport map @map_port_ipport
}
chain postrouting {
type nat hook postrouting priority srcnat + 1; policy accept;
ip6 saddr @masq_saddr masquerade
}
}
Only difference is the use of ipv6 addresses instead of ipv4 ones.
Currently has no effect: all in-tree callers pass AF_INET exclusively.
Followup patches will make nspawn expose ipv6 too and rework
IPMasquerade option to support both/v4/v6.
So far, we would allow certain control characters (NL since
b4346b9a77, TAB since 6294aa76d8), but not others. Having
other control characters in environment variable *value* is expected and widely
used, for various prompts like $LESS, $LESS_TERMCAP_*, and other similar
variables. The typical environment exported by bash already contains a dozen or
so such variables, so programs need to handle them.
We handle then correctly too, for example in 'systemctl show-environment',
since 804ee07c13. But we would still disallow setting such variables
by the user, in unit file Environment= and in set-environment/import-environment
operations. This is unexpected and confusing and doesn't help with anything
because such variables are present in the environment through other means.
When printing such variables, 'show-environment' escapes all special
characters, so variables with control characters are plainly visible.
In other uses, e.g. 'cat -v' can be used in similar fashion. This would already
need to be done to suppress color codes starting with \[.
Note that we still forbid invalid utf-8 with this patch. (Control characters
are valid, since they are valid 7-bit ascii.) I'm not sure if we should do
that, but since people haven't been actually asking for invalid utf-8, and only
for control characters, and invalid utf-8 causes other issues, I think it's OK
to leave this unchanged.
Fixes#4446, https://gitlab.gnome.org/GNOME/gnome-session/-/issues/45.
offline-passwd.[ch] are only used by systemd-tmpfiles and the relevant
test. And are not included in libshared. So, it is not suitable to
located under src/shared.
Allow to setup new bind mounts for a service at runtime (via either
DBUS or a new 'systemctl bind' verb) with a new helper that forks into
the unit's mount namespace.
Add a new integration test to cover this.
Useful for zero-downtime addition to services that are running inside
mount namespaces, especially when using RootImage/RootDirectory.
If a service runs with a read-only root, a tmpfs is added on /run
to ensure we can create the airlock directory for incoming mounts
under /run/host/incoming.
This adds the ability to specify truncate:PATH for StandardOutput= and
StandardError=, similar to the existing append:PATH. The code is mostly
copied from the related append: code. Fixes#8983.
It looks like zero'ing the struct is not enough, and with some level
of optimizations there is still non-zero padding left over.
Switch to member-by-member initialization. Also convert all remaining
bpf_attr variables in other files.
When building with Clang and using structured initialization, the
bpf_attr union is not zero-padded, so the kernel misdetects it as
an unsupported extension.
zero it until Clang's behaviour matches GCC. Do not skip the test
on Github Actions anymore.
So the currentl and only fd_is_mount_point() check is actually entirely
bogus: it passes "/" as filename argument, but that's not actually a
a valid filename, but an absolute path.
fd_is_mount_point() is written in a way tha the fd refers to a directory
and the specified path is a file directly below it that shall be
checked. The test call actually violated that rule, but still expected
success.
Let's fix this, and check for this explicitly, and refuse it.
Let's extend the test and move it to test-mountpoint-util.c where the
rest of the tests for related calls are placed.
Replaces: #18004Fixes: #17950
No functional change, just moving a bunch of things around. Before
we needed a rather complicated setup to test hostname_setup(), because
the code was in src/core/. When things are moved to src/shared/
we can just test it as any function.
The test is still "unsafe" because hostname_setup() may modify the
hostname.
Idea is to use a static ruleset, added when the first attempt to
add a masquerade or dnat rule is made.
The alternative would be to add the ruleset when the init function is called.
The disadvantage is that this enables connection tracking and NAT in the kernel
(as the ruleset needs this to work), which comes with some overhead that might
not be needed (no nspawn usage and no IPMasquerade option set).
There is no additional dependency on the 'nft' userspace binary or other libraries.
sd-netlinks nfnetlink backend is used to modify the nftables ruleset.
The commit message/comments still use nft syntax since that is what
users will see when they use the nft tool to list the ruleset.
The added initial skeleton (added on first fw_add_masquerade/local_dnat
call) looks like this:
table ip io.systemd.nat {
set masq_saddr {
type ipv4_addr
flags interval
elements = { 192.168.59.160/28 }
}
map map_port_ipport {
type inet_proto . inet_service : ipv4_addr . inet_service
elements = { tcp . 2222 : 192.168.59.169 . 22 }
}
chain prerouting {
type nat hook prerouting priority dstnat + 1; policy accept;
fib daddr type local dnat ip addr . port to meta l4proto . th dport map @map_port_ipport
}
chain output {
type nat hook output priority -99; policy accept;
ip daddr != 127.0.0.0/8 oif "lo" dnat ip addr . port to meta l4proto . th dport map @map_port_ipport
}
chain postrouting {
type nat hook postrouting priority srcnat + 1; policy accept;
ip saddr @masq_saddr masquerade
}
}
Next calls to fw_add_masquerade/add_local_dnat will then only add/delete the
element/mapping to masq_saddr and map_port_ipport, i.e. the ruleset doesn't
change -- only the set/map content does.
Running test-firewall-util with this backend gives following output
on a parallel 'nft monitor':
$ nft monitor
add table ip io.systemd.nat
add chain ip io.systemd.nat prerouting { type nat hook prerouting priority dstnat + 1; policy accept; }
add chain ip io.systemd.nat output { type nat hook output priority -99; policy accept; }
add chain ip io.systemd.nat postrouting { type nat hook postrouting priority srcnat + 1; policy accept; }
add set ip io.systemd.nat masq_saddr { type ipv4_addr; flags interval; }
add map ip io.systemd.nat map_port_ipport { type inet_proto . inet_service : ipv4_addr . inet_service; }
add rule ip io.systemd.nat prerouting fib daddr type local dnat ip addr . port to meta l4proto . th dport map @map_port_ipport
add rule ip io.systemd.nat output ip daddr != 127.0.0.0/8 fib daddr type local dnat ip addr . port to meta l4proto . th dport map @map_port_ipport
add rule ip io.systemd.nat postrouting ip saddr @masq_saddr masquerade
add element ip io.systemd.nat masq_saddr { 10.1.2.3 }
add element ip io.systemd.nat masq_saddr { 10.0.2.0/28 }
delete element ip io.systemd.nat masq_saddr { 10.0.2.0/28 }
delete element ip io.systemd.nat masq_saddr { 10.1.2.3 }
add element ip io.systemd.nat map_port_ipport { tcp . 4711 : 1.2.3.4 . 815 }
delete element ip io.systemd.nat map_port_ipport { tcp . 4711 : 1.2.3.4 . 815 }
add element ip io.systemd.nat map_port_ipport { tcp . 4711 : 1.2.3.5 . 815 }
delete element ip io.systemd.nat map_port_ipport { tcp . 4711 : 1.2.3.5 . 815 }
CTRL-C
Things not implemented/supported:
1. Change monitoring. The kernel allows userspace to learn about changes
made by other clients (using nfnetlink notifications). It would be
possible to detect when e.g. someone removes the systemd nat table.
This would need more work. Its also not clear on how to react to
external changes -- it doesn't seem like a good idea to just auto-undo
everthing.
2. 'set masq_saddr' doesn't handle overlaps.
Example:
fw_add_masquerade(true, AF_INET, "10.0.0.0" , 16);
fw_add_masquerade(true, AF_INET, "10.0.0.0" , 8); /* fails */
With the iptables backend the second call works, as it adds an
independent iptables rule.
With the nftables backend, the range 10.0.0.0-10.255.255.255 clashes with
the existing range of 10.0.0.0-10.0.255.255 so 2nd add gets rejected by the
kernel.
This will generate an error message from networkd ("Could not enable IP
masquerading: File exists").
To resolve this it would be needed to either keep track of the added elements
and perform range merging when overlaps are detected.
However, the add erquests are done using the configured network on a
device, so no overlaps should occur in normal setups.
IPv6 support is added in a extra changeset.
Fixes: #13307
for planned nft backend we have three choices:
- open/close a new nfnetlink socket for every operation
- keep a nfnetlink socket open internally
- expose a opaque fw_ctx and stash all internal data here.
Originally I opted for the 2nd option, but during review it was
suggested to avoid static storage duration because of perceived
problems with threaded applications.
This adds fw_ctx and new/free functions, then converts the existing api
and nspawn and networkd to use it.
Make sure we don't add masquerading rules without a explicitly
specified network range we should be masquerading for.
The only caller aside from test case is
networkd-address.c which never passes a NULL source.
As it also passes the network prefix, that should always be > 0 as well.
This causes expected test failure:
Failed to modify firewall: Invalid argument
Failed to modify firewall: Invalid argument
Failed to modify firewall: Invalid argument
Failed to modify firewall: Protocol not available
Failed to modify firewall: Protocol not available
Failed to modify firewall: Protocol not available
Failed to modify firewall: Protocol not available
The failing test cases are amended to expect failure on
NULL source or prefix instead of success.
Let's clean up hostname_is_valid() a bit: let's turn the second boolean
argument into a more explanatory flags field, and add a flag that
accepts the special name ".host" as valid. This is useful for the
container logic, where the special hostname ".host" refers to the "root
container", i.e. the host system itself, and can be specified at various
places.
let's also get rid of machine_name_is_valid(). It was just an alias,
which is confusing and even more so now that we have the flags param.
The commit 6f3ac0d517 drops the prefix and
suffix in TAGS= property. But there exists several rules that have like
`TAGS=="*:tag:*"`. So, the property must be always prefixed and suffixed
with ":".
Fixes#17930.
This test should ensure we notice if distros update shared libraries
that broke so name, and we still use the old soname.
(In contrast to what the commit summary says, this currently doesn#t
cover really all such deps, specifically xkbcommon and PCRE are missing,
since they currently aren't loaded from src/shared/. This is stuff to
fix later)
The BLKID and ELFUTILS strings were present twice. Let's reaarange things so that
each times requires definition in exactly one place.
Also let's sort things a bit:
the "heavy hitters" like PAM/MAC first,
then crypto libs,
then other libs, alphabetically,
compressors,
and external compat integrations.
I think it's useful for users to group similar concepts together to some extent.
For example, when checking what compression is available, it helps a lot to have
them listed together.
FDISK is renamed to LIBFDISK to make it clear that this is about he library and
the executable.
Florian Westphal
Zbigniew Jędrzejewski-Szmek
Yu Watanabe
Luca Boccassi
Lucas Werkmeister
Frantisek Sumsal
Luca Boccassi
Lennart Poettering
Yu Watanabe