In various tools and services we have a per-system and per-user concept.
So far we sometimes used a boolean indicating whether we are in system
mode, or a reversed boolean indicating whether we are in user mode, or
the LookupScope enum used by the lookup path logic.
Let's address that, in introduce a common enum for this, we can use all
across the board.
This is mostly just search/replace, no actual code changes.
Not wired in by any unit type yet, just the basic to allocate,
ref, deref and plug in to other unit types.
Includes recording the trigger unit name and passing it to the
triggered unit as TRIGGER_UNIT= env var.
bpf-firewall and bpf-devices do not have names. This complicates
debugging with bpftool(8).
Assign names starting with 'sd_' prefix:
* firewall program names are 'sd_fw_ingress' for ingress attach
point and 'sd_fw_egress' for egress.
* 'sd_devices' for devices prog
'sd_' prefix is already used in source-compiled programs, e.g.
sd_restrictif_i, sd_restrictif_e, sd_bind6.
The name must not be longer than 15 characters or BPF_OBJ_NAME_LEN - 1.
Assign names only to programs loaded to kernel by systemd since
programs pinned to bpffs are already loaded.
Currently ref count of bpf-program is kept in user space. However, the
kernel already implements its own ref count. Thus the ref count we keep for
bpf-program is redundant.
This PR removes ref count for bpf program as part of a task to simplify
bpf-program and remove redundancies, which will make the switch to
code-compiled BPF programs easier.
Part of #19270
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Example Run:
foobar.service created below is a service unit file that has a non-existing key-value
pairing (foo = bar) and is thus, syntactically invalid.
maanya-goenka@debian:~/systemd (img-support)$ cat <<EOF>img/usr/lib/systemd/system/foobar.service
> [Unit]
> foo = bar
>
> [Service]
> ExecStart = /opt/script0.sh
> EOF
The failure to create foobar.service because of the recursive dependency searching and verification has been addressed
in a different PR: systemd-analyze: add option to return an error value when unit verification fails #20233
maanya-goenka@debian:~/systemd (img-support)$ sudo build/systemd-analyze verify --root=img/ foobar.service
/home/maanya-goenka/systemd/img/usr/lib/systemd/system/foobar.service:2: Unknown key name 'foo' in section 'Unit', ignoring.
foobar.service: Failed to create foobar.service/start: Unit sysinit.target not found.
Let's assert if we ever happen to pass 0 to one of the log functions.
With the preceding commit to return -EIO from log_*(), passing 0 wouldn't
affect the return value any more, but it is still most likely an error.
The unit test code is an exception: we fairly often pass the return value
to print it, before checking what it is. So let's assert that we're not
passing 0 in non-test code. As with the previous check for %m, this is only
done in developer mode. We are depending on external code setting
errno correctly for us, which might not always be true, and which we can't
test, so we shouldn't assert, but just handle this gracefully.
I did a bunch of greps to try to figure out if there are any places where
we're passing 0 on purpose, and couldn't find any.
The one place that failed in tests is adjusted.
About "zerook" in the name: I wanted the suffix to be unambiguous. It's a
single "word" because each of the words in log_full_errno is also meaningful,
and having one term use two words would be confusing.
- Pin trivial bpf programs to bpf filesystem, compose BPFProgram= option
string and pass it to a unit. Programs store `0` in r0 BPF register for
denying action, e.g. drop a packet.
- Load trivial BPF programs
- Test is skipped if not run under root or if can not lock enough
memory.
- For egress and ingress hooks, test BPFProgram= option along with
with IP{Egress|Ingress}FilterPath=, expected result should not depend on
which rule is executed first.
Expected results for BPF_CGROUP_INET_INGRESS:
5 packets transmitted, 0 received, 100% packet loss, time 89ms
For BPF_CGROUP_INET_SOCK_CREATE:
ping: socket: Operation not permitted
Lennart Poettering
Luca Boccassi
Zbigniew Jędrzejewski-Szmek
Yu Watanabe
Julia Kartseva
alexlzhu
Luca Boccassi
Maanya Goenka