This reverts commit 6b219b74de.
This commit doesn't look right to me. We have to unmount everything
recursively *before* we MS_MOVE because the MS_MOVE will not get rid of
it for us, and we simply cannot access these mounts after the MS_MOVE is
complete anymore.
This is a fundamental difference between MS_MOVE and pivot_root(). The
latter repivots the entire mount table getting rid of anything outside
of the new root. MS_MOVE otoh just mounts a bunch of mount points to the
top, leaving in place whatever might be underneath it.
Thus, if we go through the MS_MOVE codepath we must unmount everything
explicitly before doing so because otherwise the mounts will be pinned
forever, but be entirely invisble to userspace.
If pivot_root() fails, we'll fall back to switching root via MS_MOVE.
Unlike pivot_root() that won't place the old root fs anyway, but just
hide it. That's problematic during shutdown for example, since after all
we might still want to access it from the exitrd, to disassemble it
properly.
Hence let's make things somewhat systematic: regardless if pivot_root()
or MS_MOVE is used, always make the old root fs show up in the selected
new dir.
Negative flags always raise eyebrows. Let's normalize
SWITCH_ROOT_SKIP_RECURSIVE_RUN to become SWITCH_ROOT_RECURSIVE_RUN, i.e.
make recursive behaviour opt-in, rather than opt-out. We only want it
for the initrd→host transition, and in all other cases we'd prefer to
avoid it.
This allows us to simplify some code. Also, normalize the mount point
table in switch_root() a bit, to be static const, and then just select
between two mount flag sets via SWITCH_ROOT_RECURSIVE_RUN, where the
mount flag without MS_BIND (i.e. zero) just means "skip this entry".
This does not actually change anything in behaviour, it's just
refactoring.
Follow-up for: b12d41a8bb
No functional change. In config_parse_address_generation_type() we would set
the output parameter and then say it's ignored, so it _looked_ like an error in
the code, but the variable was always initialized to SD_ID128_NULL anyway, so
the code was actually fine.
Previously we only logged our measurements to the journal. This is not a
great solution though, since regular logs are subject to rotation, which
is something we really cannot have for measurements (as it means we can
never reproduce the PCR values from the data). Hence, let's maintain an
explicit log.
Ideally, we'd just use the TCG Canonical Event Log format 1:1
(https://trustedcomputinggroup.org/resource/canonical-event-log-format/).
However it's not a perfect fit fo us, for various reasons. But let's
follow it (in its JSON incantation) as closely at it makes sense, so
that it can easily be converted to the full format by programs consuming
it.
Code comments explain where we deviate from the TCG CEL-JSON, and what
to do about it when reading the data.
New directive `NFTSet=` provides a method for integrating network configuration
into firewall rules with NFT sets. The benefit of using this setting is that
static network configuration or dynamically obtained network addresses can be
used in firewall rules with the indirection of NFT set types. For example,
access could be granted for hosts in the local subnetwork only. Firewall rules
using IP address of an interface are also instantly updated when the network
configuration changes, for example via DHCP.
This option expects a whitespace separated list of NFT set definitions. Each
definition consists of a colon-separated tuple of source type (one of
"address", "prefix", or "ifindex"), NFT address family (one of "arp", "bridge",
"inet", "ip", "ip6", or "netdev"), table name and set name. The names of tables
and sets must conform to lexical restrictions of NFT table names. The type of
the element used in the NFT filter must match the type implied by the
directive ("address", "prefix" or "ifindex") and address type (IPv4 or IPv6)
as shown type implied by the directive ("address", "prefix" or "ifindex") and
address type (IPv4 or IPv6) must also match the set definition.
When an interface is configured with IP addresses, the addresses, subnetwork
masks or interface index will be appended to the NFT sets. The information will
be removed when the interface is deconfigured. systemd-networkd only inserts
elements to (or removes from) the sets, so the related NFT rules, tables and
sets must be prepared elsewhere in advance. Failures to manage the sets will be
ignored.
/etc/systemd/network/eth.network
```
[DHCPv4]
...
NFTSet=prefix:netdev:filter:eth_ipv4_prefix
```
Example NFT rules:
```
table netdev filter {
set eth_ipv4_prefix {
type ipv4_addr
flags interval
}
chain eth_ingress {
type filter hook ingress device "eth0" priority filter; policy drop;
ip saddr != @eth_ipv4_prefix drop
accept
}
}
```
```
$ sudo nft list set netdev filter eth_ipv4_prefix
table netdev filter {
set eth_ipv4_prefix {
type ipv4_addr
flags interval
elements = { 10.0.0.0/24 }
}
}
```
I always found it confusing that most of our TPM related definitions are
in tpm2-util.h, but the PCR names in tpm-pcr.h, without the "2". Let's
fix that and make this systematic, in particular as the definitions in
the file all start with TPM2_ already.
No code flow changes, just some renaming.
Mike Yuan
Lennart Poettering
Thorsten Kukuk
Luca Boccassi
Jan Janssen
Zbigniew Jędrzejewski-Szmek
Yu Watanabe
Malte PollandPaul Meyer
Topi Miettinen
Daan De Meyer
Dan Streetman