for planned nft backend we have three choices:
- open/close a new nfnetlink socket for every operation
- keep a nfnetlink socket open internally
- expose a opaque fw_ctx and stash all internal data here.
Originally I opted for the 2nd option, but during review it was
suggested to avoid static storage duration because of perceived
problems with threaded applications.
This adds fw_ctx and new/free functions, then converts the existing api
and nspawn and networkd to use it.
In a nutshell:
1. git mv firewall-util.c firewall-util-iptables.c
2. existing external functions gain _iptables_ in their names
3. firewall-util.c provides old function names
4. build system always compiles firewall-util.c,
firewall-util-iptables.c is conditional instead (libiptc).
5. On first call to any of the 'old' API functions performs
a probe that should return the preferred backend.
In a future step, can add firewall-util-FOOTYPE.c, add its
probe function to firewall-util.c and then have calls to
fw_add_masq/local_dnat handed to the detected backend.
For now, only iptables backend exists, and no special probing
takes place for it, i.e. when systemd was built with iptables,
that will be used. If not, requets to add masquerade/dnat will
fail with same error (-EOPNOTSUPP) as before this change.
For reference, the rules added by the libiptc/iptables backend look like this:
for service export (via systemd-nspawn):
[0:0] -A PREROUTING -p tcp -m tcp --dport $exportedport -m addrtype --dst-type LOCAL -j DNAT --to-destination $containerip:$port
[0:0] -A OUTPUT ! -d 127.0.0.0/8 -p tcp -m tcp --dport $exportedport -m addrtype --dst-type LOCAL -j DNAT --to-destination $containerip:$port
for ip masquerade:
[0:0] -A POSTROUTING -s network/prefix -j MASQUERADE
Similar to the previous commit. All callers pass NULL. This will
ease initial nftables backend implementation (less features to cover).
Add the function parameters as local variables and let compiler
remove branches. Followup patch can remove the if (NULL) conditionals.
All users pass a NULL/0 for those, things haven't changed since 2015
when this was added originally, so remove the arguments.
THe paramters are re-added as local function variables, initalised
to NULL or 0. A followup patch can then manually remove all
if (NULL) rather than leaving dead-branch optimization to compiler.
Reason for not doing it here is to ease patch review.
Not requiring support for this will ease initial nftables backend
implementation.
In case a use-case comues up later this feature can be re-added.
These lines are generally out-of-date, incomplete and unnecessary. With
SPDX and git repository much more accurate and fine grained information
about licensing and authorship is available, hence let's drop the
per-file copyright notice. Of course, removing copyright lines of others
is problematic, hence this commit only removes my own lines and leaves
all others untouched. It might be nicer if sooner or later those could
go away too, making git the only and accurate source of authorship
information.
This part of the copyright blurb stems from the GPL use recommendations:
https://www.gnu.org/licenses/gpl-howto.en.html
The concept appears to originate in times where version control was per
file, instead of per tree, and was a way to glue the files together.
Ultimately, we nowadays don't live in that world anymore, and this
information is entirely useless anyway, as people are very welcome to
copy these files into any projects they like, and they shouldn't have to
change bits that are part of our copyright header for that.
hence, let's just get rid of this old cruft, and shorten our codebase a
bit.
Files which are installed as-is (any .service and other unit files, .conf
files, .policy files, etc), are left as is. My assumption is that SPDX
identifiers are not yet that well known, so it's better to retain the
extended header to avoid any doubt.
I also kept any copyright lines. We can probably remove them, but it'd nice to
obtain explicit acks from all involved authors before doing that.
The advantage is that is the name is mispellt, cpp will warn us.
$ git grep -Ee "conf.set\('(HAVE|ENABLE)_" -l|xargs sed -r -i "s/conf.set\('(HAVE|ENABLE)_/conf.set10('\1_/"
$ git grep -Ee '#ifn?def (HAVE|ENABLE)' -l|xargs sed -r -i 's/#ifdef (HAVE|ENABLE)/#if \1/; s/#ifndef (HAVE|ENABLE)/#if ! \1/;'
$ git grep -Ee 'if.*defined\(HAVE' -l|xargs sed -i -r 's/defined\((HAVE_[A-Z0-9_]*)\)/\1/g'
$ git grep -Ee 'if.*defined\(ENABLE' -l|xargs sed -i -r 's/defined\((ENABLE_[A-Z0-9_]*)\)/\1/g'
+ manual changes to meson.build
squash! build-sys: use #if Y instead of #ifdef Y everywhere
v2:
- fix incorrect setting of HAVE_LIBIDN2
Florian Westphal