To make sd-device properly usable for all programs we need to provide an
API for the "action" field of an event, it's one of the most relevant
ones, and it was so far missing.
This also adds sd_device_get_seqnum(), which isn't that interesting,
except for generating pretty debug output, which we use it ourselves
for.
This also makes device_new_from_stat_rdev() public, as it is truly
useful, as we can see in our own uses of it, and I think is fairly
generic to show up in the public APIs.
Apparently, in our current public headers (i.e. those called sd-*.h) we
suffixed typedefs that we use as values with _t, but we didn't do this
for enum typedefs. Fix that while this stuff is not actually public yet.
With this scheme "value typedefs" now end systematically in _t, and
"object typedefs" (i.e. structures that are typically passed around via
pointers and not values) do not.
No code changes, just some renaming.
Fragmenting sucks, let's avoid it. Thus let's start tracking the maximum
fragment size we receive.
Also, let's redo a transaction via TCP if we see fragmenting on UDP, as
effective mitigation against DNS fragment attacks.
Let's take all MTU info we possibly have into account, i.e. the one
reported via netlink, as before and the one the socket might now (from
PMTUD and such), clamped by our own ideas.
We can later use this to adapt our announced EDNS buffer size in order
to avoid fragmentation to make the best of large datagrams while still
avoiding he security weaknesses of it.
I'm seeing the following with kernel-core-5.10.16-200.fc33.x86_64:
$ sudo SYSTEMD_LOG_LEVEL=debug build/systemd-rfkill
Reading struct rfkill_event: got 8 bytes.
A new rfkill device has been added with index 0 and type bluetooth.
Found cgroup2 on /sys/fs/cgroup/, full unified hierarchy
Found container virtualization none.
rfkill0: Operating on rfkill device 'tpacpi_bluetooth_sw'.
Writing struct rfkill_event successful (8 of 9 bytes).
Loaded state '0' from /var/lib/systemd/rfkill/platform-thinkpad_acpi:bluetooth.
Reading struct rfkill_event: got 8 bytes.
A new rfkill device has been added with index 1 and type wwan.
rfkill1: Operating on rfkill device 'tpacpi_wwan_sw'.
Writing struct rfkill_event successful (8 of 9 bytes).
Loaded state '0' from /var/lib/systemd/rfkill/platform-thinkpad_acpi:wwan.
Reading struct rfkill_event: got 8 bytes.
A new rfkill device has been added with index 2 and type bluetooth.
rfkill2: Operating on rfkill device 'hci0'.
Writing struct rfkill_event successful (8 of 9 bytes).
Loaded state '0' from /var/lib/systemd/rfkill/pci-0000:00:14.0-usb-0:7:1.0:bluetooth.
Reading struct rfkill_event: got 8 bytes.
A new rfkill device has been added with index 3 and type wlan.
rfkill3: Operating on rfkill device 'phy0'.
Writing struct rfkill_event successful (8 of 9 bytes).
Loaded state '0' from /var/lib/systemd/rfkill/pci-0000:04:00.0:wlan.
All events read and idle, exiting.
We were expecting a read of exactly RFKILL_EVENT_SIZE_V1==8 bytes. But the
structure has 9 after [1].
[1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=14486c82612a177cb910980c70ba900827ca0894
For some reason the kernel does not accept the full structure size, but cuts
the write short after 8 bytes:
static ssize_t rfkill_fop_write(struct file *file, const char __user *buf,
size_t count, loff_t *pos)
{
struct rfkill_event ev;
/* we don't need the 'hard' variable but accept it */
if (count < RFKILL_EVENT_SIZE_V1 - 1)
return -EINVAL;
/*
* Copy as much data as we can accept into our 'ev' buffer,
* but tell userspace how much we've copied so it can determine
* our API version even in a write() call, if it cares.
*/
count = min(count, sizeof(ev));
if (copy_from_user(&ev, buf, count))
return -EFAULT;
... so it should accept the full size. I'm not sure what is going on here.
But we don't care about the extra fields, so let's accept a write as long as
it's at least RFKILL_EVENT_SIZE_V1.
Fixes#18677.
Our own config generates logs like this:
systemd-sysctl[1280]: Not setting net/ipv4/conf/all/rp_filter (explicit setting exists).
systemd-sysctl[1280]: Not setting net/ipv4/conf/default/rp_filter (explicit setting exists).
systemd-sysctl[1280]: Not setting net/ipv4/conf/all/accept_source_route (explicit setting exists).
systemd-sysctl[1280]: Not setting net/ipv4/conf/default/accept_source_route (explicit setting exists).
systemd-sysctl[1280]: Not setting net/ipv4/conf/all/promote_secondaries (explicit setting exists).
systemd-sysctl[1280]: Not setting net/ipv4/conf/default/promote_secondaries (explicit setting exists).
There is no error and nothing really to see.
Rolling releases, like ArchLinux, do not set VERSION_ID in
their os-release files, so allow matching simply on ID if the host
does not provide anything.
--no-legend is replaced by --legend=no.
--quiet now implies --legend=no, but --legend=yes may be used to override that.
--quiet controls hints and warnings and such, and --legend controls just the
legends. I think it makes sense to allow both to controlled independently, in
particular --quiet --legend makes sense when using systemctl in a script to
provide some user-visible output.
Fixes#18560.
We were passing a reference to 'int arg_seal' to config_parse_bool(),
which expects a 'bool *'. Luckily, this would work, because 'bool'
is smaller than 'int', so config_parse_bool() would set the least-significant
byte of arg_seal. At least I think so. But let's use consistent types ;)
Also, modernize style a bit and don't use integers in boolean context.
This nicely covers the case when optarg is optional. The same parser can be
used when the option string passed to getopt_long() requires a parameter and
when it doesn't.
The error messages are made consistent.
Also fixes a log error c&p in --crash-reboot message.
Lennart Poettering
Zbigniew Jędrzejewski-Szmek
Susant Sahani
Luca Boccassi
Yu Watanabe