This reverts PR #23269 and its follow-up commit. Especially,
2299b1cae3 (partially), and
3cf63830ac.
The PR was merged without final approval, and has several issues:
- The NetLabel for static addresses are not assigned, as labels are
stored in the Address objects managed by Network, instead of Link.
- If NetLabel is specified for a static address, then the address
section will be invalid and the address will not be configured,
- It should be implemented with Request object,
- There is no test about the feature.
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.
Fixes build with musl:
| ../git/src/shared/dissect-image.c: In function 'mount_image_privately_interactively':
| ../git/src/shared/dissect-image.c:2986:34: error: 'LOCK_SH' undeclared (first use in this function)
| 2986 | r = loop_device_flock(d, LOCK_SH);
| | ^~~~~~~
Note, if `n != SIZE_MAX`, we cannot check the existence of the specified
string in the set without duplicating the string. And, set_consume() also
checks the existence of the string. Hence, it is not necessary to call
set_contains() if `n != SIZE_MAX`.
dns_label_unescape() does not nul-terminate the buffer if it does not
have enough space. Hence, if a lable is enough long, then strjoin()
triggers buffer-overflow.
Fixes#23705.
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 }
}
}
```
New directive `NetLabel=` provides a method for integrating dynamic network
configuration into Linux NetLabel subsystem rules, used by Linux security
modules (LSMs) for network access control. The option expects a whitespace
separated list of NetLabel labels. The labels must conform to lexical
restrictions of LSM labels. When an interface is configured with IP addresses,
the addresses and subnetwork masks will be appended to the NetLabel Fallback
Peer Labeling rules. They will be removed when the interface is
deconfigured. Failures to manage the labels will be ignored.
Example:
```
[DHCP]
NetLabel=system_u:object_r:localnet_peer_t:s0
```
With the above rules for interface `eth0`, when the interface is configured with
an IPv4 address of 10.0.0.0/8, `systemd-networkd` performs the equivalent of
`netlabelctl` operation
```
$ sudo netlabelctl unlbl add interface eth0 address:10.0.0.0/8 label:system_u:object_r:localnet_peer_t:s0
```
Result:
```
$ sudo netlabelctl -p unlbl list
...
interface: eth0
address: 10.0.0.0/8
label: "system_u:object_r:localnet_peer_t:s0"
...
```
We already store the dlopen() stuff for other libraries in util headers
as well so let's do the same for pcre2. We also move the definition of
some trivial cleanup functions from journalctl.c to pcre2-util.h
IIUC, with MAX() we get a VLA and the size is "decided" at runtime,
even though the result is always the same, but with CONST_MAX() we
get a normal stack variable.
The general rule should be to be strict when parsing data, but lenient
when printing it. Or in other words, we should verify data in verification
functions, but not when printing things. It doesn't make sense to refuse
to print a value that we are using internally.
We were tripping ourselves in some of the print functions:
we want to report than an address was configured with too-long prefix, but
the log line would use "n/a" if the prefix was too long. This is not useful.
Most of the time, the removal of the check doesn't make any difference,
because we verified the prefix length on input.
Since we don't need the error value, and the buffer is allocated with a fixed
size, the whole logic provided by in_addr_to_string() becomes unnecessary, so
it's enough to wrap inet_ntop() directly.
inet_ntop() can only fail with ENOSPC. But we specify a buffer that is supposed
to be large enough, so this should never fail. A bunch of tests of this are added.
This allows all the wrappers like strna(), strnull(), strempty() to be dropped.
The guard of 'if (DEBUG_LOGGING)' can be dropped from around log_debug(),
because log_debug() implements the check outside of the function call. But
log_link_debug() does not, so it we need it to avoid unnecessary evaluation of
the formatting.
Testing the error paths is very important. If we are not root, we should
try and get a failure, which we should report nicely and mark the test
as skipped. After those checks are removed, this is what seems to happen.
This way we can see what will happen e.g. in the user manager when we try
to perform some bpf ops.
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.
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().
Some compiler wrappers like honggfuzz pass -fno-builtin explicitly
and because of that the tests where fabs is used fail to compile
with something like
```
FAILED: test-bus-marshal
...
/usr/bin/ld: test-bus-marshal.p/src_libsystemd_sd-bus_test-bus-marshal.c.o: undefined reference to symbol 'fabs@@GLIBC_2.2.5'
/usr/bin/ld: /usr/lib64/libm.so.6: error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status
```
Fun fact: it took honggfuzz less than a minute to discover
https://github.com/advisories/GHSA-gmc7-pqv9-966m used by
systemd to compress/descompress some stuff.
The existing sd_hwdb_new function always initializes the hwdb from the
first successful hwdb.bin it finds from hwdb_bin_paths. This means there
is currently no way to initialize a hwdb from an explicit path, which
would be useful for systemd-hwdb query.
Add sd_hwdb_new_from_path to allow a sd_hwdb to be initialized from a
custom path outside of hwdb_bin_paths.
So far we had the rule that '' == '', '0_' == '0', but '_' > ''. This means
that the general rule that strings are compared iteratively, and each
segment that compares equal can be dropped and the comparison resumes at
the following characters wasn't true in such cases. Similarly, '0~' < '0',
but after dropping the common segment, '~' > ''.
The special handling of empty strings is dropped, and '_' == '' and
'~' < ''.
shmat() requires the CAP_IPC_OWNER capability. When running test-seccomp
in environments with root + CAP_SYS_ADMIN, but not CAP_IPC_OWNER,
memory_deny_write_execute_shmat would fail. This fixes it.
* Avoid traling slash as most links are defined without.
* Always use https:// protocol and www. subdomain
Allows for easier tree-wide linkvalidation
for our migration to systemd.io.
This will be helpful in cases where we are repeatedly adding entries
to a long strv and want to skip the iteration over old entries leading
to quadratic behaviour.
Note that we don't want to calculate the length if not necessary, so
the calculation is delayed until after we've checked that value is not
NULL.
The docs are not entirely clear what glyphs qualify as digits.
The function is supposed to be locale-dependent, but I couldn't
get it to return true on any non-ascii digits I tried.
But it's better to be safe than sorry, let's use our trivial
replacement instead.
