Those messages simply *feel* dated: "The system is going for suspend NOW!".
Let's say "The system will suspend|power off|hibernate|… now!" instead.
The exclamation mark is enough to show the urgency.
Also, the "the" seemed out of place. We're not talking about a specific reboot.
DnsPacket.ifindex=1 (loopback) is normalized to 0 whenever a message is
received on the loopback iface, so for both listeners, 127.0.0.53 and
127.0.0.54, the ifindex will be set to 0 by manager_recv() for queries
that have a local origin.
Replies to such local messages need to set a proper ifindex in any
case, as the supplied source-address would otherwise be ignored in
manager_ipv4_send() (CMSG generation is skipped due to ifindex > 0 check).
Note that this change only forces `ifindex` to loopback if it was actually
normalized to `0` before (due to a loopback detection) in order to keep the
nat-to-127.0.0.54-from-another-interface usecase that was described in
a8d0906344 intact.
Also note that nat is not supported for the main stub 127.0.0.53 which is
why forcing LOOPBACK_IFINDEX was/is fine for that case.
Fixes#23495
Fixes#23520. Replaces #23555.
The problem started with cdf370626f and
90b1ec03b2 which together started printing the
wall message in more cases. The motivation for those change was reasonable, but
this clearly causes problems described in #23520: users are getting unexpected
wall messages. Xterm, urxvt, (anything using libutempter?), and tmux (in some
configurations), register local pty sessions in utmp.
So let's try to suppress the message for local pseudo-terminal logins. This
patch based on #23538, but instead of filtering just on /dev/pts, it uses the
.ut_addr_v6 to only filter out local entries.
utmpdump doesn't print all the details. Looking at the list if useful
when trying to tweak the wall filtering logic.
This doesn't do much, but at least it serves as a smoke test for the cleanup
functions.
Otherwise, this easily trigger another exception:
```
======================================================================
ERROR: test_erspan_tunnel_v0 (__main__.NetworkdNetDevTests)
----------------------------------------------------------------------
Traceback (most recent call last):
File "./test/test-network/systemd-networkd-tests.py", line 686, in wait_online
check_output(*args, env=env)
File "./test/test-network/systemd-networkd-tests.py", line 65, in check_output
return subprocess.check_output(command, universal_newlines=True, **kwargs).rstrip()
File "/usr/lib64/python3.6/subprocess.py", line 356, in check_output
**kwargs).stdout
File "/usr/lib64/python3.6/subprocess.py", line 438, in run
output=stdout, stderr=stderr)
subprocess.CalledProcessError: Command '['/usr/lib/systemd/systemd-networkd-wait-online', '--timeout=20s', '--interface=erspan99:routable', '--interface=erspan98:routable', '--interface=dummy98:degraded']' returned non-zero exit status 1.
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "./test/test-network/systemd-networkd-tests.py", line 1808, in test_erspan_tunnel_v0
self.wait_online(['erspan99:routable', 'erspan98:routable', 'dummy98:degraded'])
File "./test/test-network/systemd-networkd-tests.py", line 689, in wait_online
output = check_output(*networkctl_cmd, '-n', '0', 'status', link.split(':')[0], env=env)
File "./test/test-network/systemd-networkd-tests.py", line 65, in check_output
return subprocess.check_output(command, universal_newlines=True, **kwargs).rstrip()
File "/usr/lib64/python3.6/subprocess.py", line 356, in check_output
**kwargs).stdout
File "/usr/lib64/python3.6/subprocess.py", line 438, in run
output=stdout, stderr=stderr)
subprocess.CalledProcessError: Command '['/usr/bin/networkctl', '-n', '0', 'status', 'erspan99']' returned non-zero exit status 1.
```
The casts in this and the next few commits are curently necessary
because CHAR8 is defined as uint8_t in gnu-efi, while char is signed.
Once we switch from gnu-efi typedefs to stdint types, the casts
will be dropped.
We currently have a convoluted and complex selection of which random
numbers to use. We can simplify this down to two functions that cover
all of our use cases:
1) Randomness for crypto: this one needs to wait until the RNG is
initialized. So it uses getrandom(0). If that's not available, it
polls on /dev/random, and then reads from /dev/urandom. This function
returns whether or not it was successful, as before.
2) Randomness for other things: this one uses getrandom(GRND_INSECURE).
If it's not available it uses getrandom(GRND_NONBLOCK). And if that
would block, then it falls back to /dev/urandom. And if /dev/urandom
isn't available, it uses the fallback code. It never fails and
doesn't return a value.
These two cases match all the uses of randomness inside of systemd.
I would prefer to make both of these return void, and get rid of the
fallback code, and simply assert in the incredibly unlikely case that
/dev/urandom doesn't exist. But Luca disagrees, so this commit attempts
to instead keep case (1) returning a return value, which all the callers
already check, and fix the fallback code in (2) to be less bad than
before.
For the less bad fallback code for (2), we now use auxval and some
timestamps, together with various counters representing the invocation,
hash it all together and provide the output. Provided that AT_RANDOM is
secure, this construction is probably okay too, though notably it
doesn't have any forward secrecy. Fortunately, it's only used by
random_bytes() and not by crypto_random_bytes().
Zbigniew Jędrzejewski-Szmek
Yu Watanabe
Benjamin Franzke
Alexander Shopov
Jan Janssen
Frantisek Sumsal
Matthias Lisin
Jason A. Donenfeld