On Sat, Feb 26, 2022 at 9:53 AM Martin-Éric Racine
<martin-eric.rac...@iki.fi> wrote:
>
> On Fri, Feb 25, 2022 at 3:52 PM Roy Marples <r...@marples.name> wrote:
> >
> > On 25/02/2022 09:25, Martin-Éric Racine wrote:
> > > Right now, my personal experiements with dhcpcd indicate that
> > > something as simple as passing options to wpa_supplicant via dhcpcd's
> > > configuration file is not an easy task.
> >
> > Why would you want to? They have separate domains of responsibility. One
> > configures the addressing and routes and other misc related stuff and the
> > other
> > brings up the actual link to do this on.
>
> Because having the configuration data for all interfaces is
> /etc/network/interfaces' whole point.
>
> > dhcpcd's wpa_supplicant hook was written to solely support hotplugging a USB
> > wireless stick into a machine without any kind of hotplug support.
> > Since then I have added then -M flag to wpa_supplicant so it can do it by
> > itself.
>
> Which is a problem. dhcpcd and systemd currently compete for control
> of the wireless device. systemd tries to rename it to follow
> Predictable Network Interface Names at the same time as dhcpcd tries
> to to connect it to a network. It results in configuration failing.
> Also, unless I missed something, dhcpcd doesn't currently have the
> built-in logic to understand whether a device is wireless (needs WPA)
> or not (doesn't need anythign else than DHCP).
>
> > Now if you want to configure wpa_supplicant via dhcpcd for a specific
> > wireless
> > network then the dhcpcd-ui project exists for that and relies on the
> > wpa_supplicant config being writable via the wpa_supplicant control socket.
>
> Nice idea for laptops, not so good idea for hosts that need to
> repeatedly connect to the same AP and then perform otherws tasks such
> as serve as a bridge for a LAN. For instance:
>
> allow-hotplug enp9s0 wlp12s0
> iface enp9s0 inet dhcp
> iface enp9s0 inet6 auto
> privext 2
> dhcp 1
> iface wlp12s0 inet dhcp
> wpa-ssid <SSID>
> wpa-psk <password>
> iface wlp12s0 inet6 auto
> privext 2
> dhcp 1
>
> This results in the host always getting a connection. If just routes
> through whichever interface managed to get a DHCP configuration.
>
> > > Ditto for enabling prefix
> > > delegation to a second interface.
> >
> > Lets talk about this separately.
> > Please email me and I'll help you with your setup, no need to muddy an
> > unrelated
> > debian bug report about it.
>
> The point here was how not doing it in a flat file where all
> interfaces can be centrally configured is a distraction. The one file
> provides a centralized view and a uniform syntax.
>
> > > Via ifupdown's
> > > /etc/network/interfaces these follow a normalized syntax that is
> > > completely independant of which tools perform the actual network
> > > configuration under the hood.
> >
> > ifupdown is great for static configuration.
> > I would use it to configure links such as bonding, bridging, etc.
> > Anything dynamic, not so great.
> >
> > For example having ifupdown start separate instances of a DHCP client per
> > interface is not only a waste of resources it also introduces undefined
> > behaviour because only one of these can bind to the unspecified address. The
> > only way around this is opening a socket for every address on the interface.
> > If you have a lot of interfaces or addresses dhcpcd would rapidly drain
> > available resources just to guarantee a defined behaviour.
>
> The separate stanzas for inet and inet6 is something I've long
> wondered about. dhclient's man page has the answer:
>
> 4 Use the DHCPv4 protocol to obtain an IPv4 address and
> configuration parameters. This is the default and cannot be combined
> with -6.
>
> This is precisely why I want to replace dhclient with dhcpcd as the
> default DHCP client. If an interface is marked in
> /etc/network/interfaces as DHCP type, both IPv4 and IPv6 should be
> attempted in a transparent way, and dhcpcd does that wonderfully.
>
> > >>> Configure's upstream default paths make Lintian bark, so I've kept the
> > >>> overrides in debian/rules for now. It might be worth working with
> > >>> upstream on making the defaults do what FHS and current packaging
> > >>> practices want.
> > >>
> > >> The default upstream paths mirror that of a BSD system. I belive that is
> > >> in
> > >> conflict with FHS.
> > >
> > > There's more. For instance, manual pages canonically go to
> > > /usr/share/man/manX (or /usr/local/share/man/manX for locally-built
> > > packages). dhcpcd's Configure defaults put these in /share/man/manX if
> > > no prefix is passed to configure. Also hooks are currectly put in
> > > ${prefix}/libexec (which is the correct FHS location), but since they
> > > are not executable and lack the Bourne shell shebang, Lintian barks.
> >
> > dhcpcd's configure default puts them into /usr/share/man/manX if nothing is
> > passed to configure. Maybe the Debian package is doing something
> > differently?
> >
> > The hooks that dhcpcd-run-hooks calls make zero sense being executed
> > outside of
> > dhcpcd-run-hooks so being marked executable with a shell shebang also makes
> > zero
> > sense.
>
> Here's what I get on a build that uses the upstream configure defaults
> as-is (i.e.overrides in debian/rules disabled):
>
> SYSCONFDIR = /etc
> SBINDIR = /usr/sbin
> LIBDIR = /lib/i386-linux-gnu
> LIBEXECDIR = /usr/libexec
> DBDIR = /var/db/dhcpcd
> RUNDIR = /run/dhcpcd
> MANDIR = /share/man
> DATADIR = /usr/share
> HOOKSCRIPTS =
> EGHOOKSCRIPTS = 50-yp.conf
> STATUSARG =
> PRIVSEPUSER = dhcpcd
>
> E: dhcpcd5: non-standard-dir-in-var var/db/
> E: dhcpcd5: non-standard-toplevel-dir share/
> W: dhcpcd5-dbgsym: elf-error In program headers: Unable to find
> program interpreter name
> [usr/lib/debug/.build-id/df/5e855a885adce7a0063b55ff5f1e406f77cd48.debug]
> W: dhcpcd5: executable-not-elf-or-script usr/libexec/dhcpcd-hooks/01-test
> W: dhcpcd5: executable-not-elf-or-script
> usr/libexec/dhcpcd-hooks/20-resolv.conf
> W: dhcpcd5: executable-not-elf-or-script usr/libexec/dhcpcd-hooks/30-hostname
> W: dhcpcd5: file-in-unusual-dir share/man/man5/dhcpcd.conf.5
> W: dhcpcd5: file-in-unusual-dir share/man/man8/dhcpcd-run-hooks.8
> W: dhcpcd5: file-in-unusual-dir share/man/man8/dhcpcd.8
> W: dhcpcd5: no-manual-page usr/sbin/dhcpcd
>
> drwxr-xr-x root/root 0 2022-02-24 15:08 ./etc/
> -rw-r--r-- root/root 1429 2022-02-24 15:08 ./etc/dhcpcd.conf
> drwxr-xr-x root/root 0 2022-02-24 15:08 ./etc/init.d/
> -rwxr-xr-x root/root 1905 2019-05-03 16:14 ./etc/init.d/dhcpcd
> drwxr-xr-x root/root 0 2022-02-24 15:08 ./lib/
> drwxr-xr-x root/root 0 2022-02-24 15:08 ./lib/systemd/
> drwxr-xr-x root/root 0 2022-02-24 15:08 ./lib/systemd/system/
> -rw-r--r-- root/root 191 2019-05-03 16:14
> ./lib/systemd/system/dhcpcd.service
> drwxr-xr-x root/root 0 2022-02-24 15:08 ./share/
> drwxr-xr-x root/root 0 2022-02-24 15:08 ./share/man/
> drwxr-xr-x root/root 0 2022-02-24 15:08 ./share/man/man5/
> -rw-r--r-- root/root 30106 2022-02-24 15:08 ./share/man/man5/dhcpcd.conf.5
> drwxr-xr-x root/root 0 2022-02-24 15:08 ./share/man/man8/
> -rw-r--r-- root/root 7091 2022-02-24 15:08
> ./share/man/man8/dhcpcd-run-hooks.8
> -rw-r--r-- root/root 26559 2022-02-24 15:08 ./share/man/man8/dhcpcd.8
> drwxr-xr-x root/root 0 2022-02-24 15:08 ./usr/
> drwxr-xr-x root/root 0 2022-02-24 15:08 ./usr/lib/
> drwxr-xr-x root/root 0 2022-02-24 15:08 ./usr/lib/dhcpcd/
> drwxr-xr-x root/root 0 2022-02-24 15:08 ./usr/lib/dhcpcd/dhcpcd-hooks/
> -rw-r--r-- root/root 2496 2019-05-03 16:14
> ./usr/lib/dhcpcd/dhcpcd-hooks/60-ntp-common.conf
> -rw-r--r-- root/root 380 2019-05-03 16:14
> ./usr/lib/dhcpcd/dhcpcd-hooks/62-chrony.conf
> -rw-r--r-- root/root 466 2019-05-03 16:14
> ./usr/lib/dhcpcd/dhcpcd-hooks/64-timesyncd.conf
> -rw-r--r-- root/root 546 2019-05-03 16:14
> ./usr/lib/dhcpcd/dhcpcd-hooks/66-ntp.conf
> -rw-r--r-- root/root 549 2019-05-03 16:14
> ./usr/lib/dhcpcd/dhcpcd-hooks/68-openntpd.conf
> drwxr-xr-x root/root 0 2022-02-24 15:08 ./usr/libexec/
> drwxr-xr-x root/root 0 2022-02-24 15:08 ./usr/libexec/dhcpcd-hooks/
> -rwxr-xr-x root/root 734 2022-02-24 15:08
> ./usr/libexec/dhcpcd-hooks/01-test
> -rwxr-xr-x root/root 6164 2022-02-24 15:08
> ./usr/libexec/dhcpcd-hooks/20-resolv.conf
> -rwxr-xr-x root/root 3762 2022-02-24 15:08
> ./usr/libexec/dhcpcd-hooks/30-hostname
> -rwxr-xr-x root/root 8163 2022-02-24 15:08 ./usr/libexec/dhcpcd-run-hooks
> drwxr-xr-x root/root 0 2022-02-24 15:08 ./usr/sbin/
> -rwxr-xr-x root/root 404904 2022-02-24 15:08 ./usr/sbin/dhcpcd
> drwxr-xr-x root/root 0 2022-02-24 15:08 ./usr/share/
> drwxr-xr-x root/root 0 2022-02-24 15:08 ./usr/share/dhcpcd/
> drwxr-xr-x root/root 0 2022-02-24 15:08 ./usr/share/dhcpcd/hooks/
> -rw-r--r-- root/root 2832 2022-02-24 15:08
> ./usr/share/dhcpcd/hooks/10-wpa_supplicant
> -rw-r--r-- root/root 885 2022-02-24 15:08
> ./usr/share/dhcpcd/hooks/15-timezone
> -rw-r--r-- root/root 814 2022-02-24 15:08
> ./usr/share/dhcpcd/hooks/29-lookup-hostname
> -rw-r--r-- root/root 1163 2022-02-24 15:08
> ./usr/share/dhcpcd/hooks/50-yp.conf
> drwxr-xr-x root/root 0 2022-02-24 15:08 ./usr/share/doc/
> drwxr-xr-x root/root 0 2022-02-24 15:08 ./usr/share/doc/dhcpcd5/
> -rw-r--r-- root/root 2619 2022-02-24 15:08
> ./usr/share/doc/dhcpcd5/changelog.Debian.gz
> -rw-r--r-- root/root 7966 2022-02-24 09:34
> ./usr/share/doc/dhcpcd5/copyright
> drwxr-xr-x root/root 0 2022-02-24 15:08 ./var/
> drwxr-xr-x root/root 0 2022-02-24 15:08 ./var/db/
> drwxr-xr-x root/root 0 2022-02-24 15:08 ./var/db/dhcpcd/
>
> Martin-Éric
I forgot to include the actual configure stanza that gets issued. Here
it is, straight from the build log:
dh_auto_configure
./configure --build=i686-linux-gnu --prefix=/usr
--includedir=\${prefix}/include --mandir=\${prefix}/share/man
--infodir=\${prefix}/share/info --sysconfdir=/etc --localstatedir=/var
--disable-option-checking --disable-silent-rules
--libdir=\${prefix}/lib/i386-linux-gnu --runstatedir=/run
--disable-maintainer-mode --disable-dependency-tracking
configure args: --build=i686-linux-gnu --prefix=/usr
--includedir=${prefix}/include --mandir=${prefix}/share/man
--infodir=${prefix}/share/info --sysconfdir=/etc --localstatedir=/var
--disable-option-checking --disable-silent-rules
--libdir=${prefix}/lib/i386-linux-gnu --runstatedir=/run
--disable-maintainer-mode --disable-dependency-tracking
./configure: WARNING: unknown option --disable-option-checking
Martin-Éric
