When current dracut receives an ip with netmask of 255.255.255.255 via DHCP,
setting the also supplied default gateway fails (because it is obviously not
within the netmask).
The setup with a netmask of /32 is quite common in colocation datacenters
where you don't want the machines of two different customers to directly talk
to each other. At least two of the biggest colocation providers in Germany
(1&1 and Strato) do it that way. NetworkManager supports this kind of setup
and the dhclient-scripts of several distributions too.
In this patch I have implemented a simple approach very similar to what is
found in Debian. The dhclient-script from Fedora uses a more sophisticated
approach, but that relies on the ipcalc utility which would introduce a
dependency on Fedora-initscripts for dracut.
Signed-off-by: Gerd von Egidy <gerd.von.egidy@intra2net.com>
When you define the gateway for an interface, dracut sets it up with:
ip route add default via $gw dev $netif
If a default route is already set (e.g. if you have multiple NICs), this
will fail with the message "RTNETLINK answers: File exists".
So, if your first NIC isn't usable as a default route
Using "ip route replace default" instead allows ifup/dhclient-script to
correctly change the default route to the new interface.
The dracut dhclient-script.sh should set address lifetimes to the DHCP
lease time, so that other stuff (like NetworkManager!) knows that the
address is temporary and was created by DHCP.
https://bugzilla.redhat.com/show_bug.cgi?id=1058519
linkup is a wrapper function for waiting interface ready and up.
change to use linkup as what we do in ifup script.
Signed-off-by: Dave Young <dyoung@redhat.com>
dhclient initqueue hook fix
setup_net is scheduled in initqueue, sometimes it does not get chance to run
So the default route will not be set properly
Add a check in initqueue/finished to resolve this issue.
Signed-off-by: Dave Young <dyoung@redhat.com>
For kdump we need scp vmcore to remote machine, the nic to be used is
not limited to netroot one. we need a feature for manually bringing up
network interface. Also it is useful for emergency shell with
ssh-client for recovery or test purpose
I implement this by adding one argument to ifup script, user can use
`/sbin/ifup eth0 -m` to bring up eth0, note ifup will regard it a
manual operation for the nic specified in 1st argument if there's
the 2nd argument.
If same nic is used for netroot the 2nd argument will be ignored,
in this case we will leave netroot bring up it automatically to
avoid side effect. And in this case hooks such as kdump will need to
execute after netroot mounted.
`ifup eth0 -m` will create /tmp/net.eth0.manualup stamp file,
later dhclient-script can check this and pass $2 to netroot,
then netroot script will bring eth0 up
Thanks for comments and suggestions from David Dillow.
Signed-off-by: Dave Young <dyoung@redhat.com>
When booting with nfsroot, dracut doesn't necessarily set the initial
hostname correctly.
According to dhcp-options(5), the name may or may not be qualified with
the local domain. It goes on to say "it is preferable to use the
domain-name option to specify the domain name".
So dhclient-script needs to be able to handle the cases: a) where
host-name is fully qualified and domain name is also specified; b)
where hostname is fully qualified and the domain is not separately
specified; c) where host-name is "short" and domain-name is also
specified; and d) do its best where host-name is short but domain-name
is not specified.
The dhclient-script in initramfs does not handle case "c", apparently
the preferred situation properly, setting hostname to "short".
https://bugzilla.redhat.com/show_bug.cgi?id=756347
We want all "/var/run" information to live in /dev/.run, until the real
root is mounted.
Therefore we mount a tmpfs on /dev/.run, which can/will be bind/move mounted
on /var/run later on.
The manpage for dhclient-script says:
Before actually configuring the address, dhclient-script should
somehow ARP for it and exit with a nonzero status if it receives a
reply.
By using arping in dracut this is very easy, since arping has a
specific option to do just that.
The usual approach to setting mtus is to set the interface down,
set the mtu then set the interface back up again. Modern hardware
and/or drivers may support setting this on the fly, so we try
this and fall back to the old behaviour it it doesn't work.
In addition this patch only allows mtus greater than 576, this is
taken from debian/ubuntu dhclient-script.
The Bug causing dhclient to recall BIND has been identified:
dhclient-script runs with #!/bin/sh -e, causing setup_interface
to fail if no hostname is provided by dhcp as it is the last statement
in that function.
Instead of configuring devices when they are ready, ifup and
dhclient-script write script files which are then sourced by
netroot.
This solves the problem of having multiple interfaces and not knowing
which one to use for dhcp or default route. This way, netroot (which
is serialized anyway) configures the interface before calling the root
handler and deconfigures it if the handler failed.
Example: root=nfs:server:path and ip=dhcp with eth0 and eth1 receiving
a dhcp reply, but eth0 is the correct one to use.
Assuming eth1 is the first to receive the dhcp-reply, netroot starts
and configures eth1. nfsroot is run but fails, so eth1 is deconfigured. If
eth0 has received a dhcp-reply (or not, then we wait) the other locked
netroot process starts and tries with eth0 and succeeds.
Multiline conditionals ( && { ... } ) should use if, function
declarations go to the top of the file, add/update comments and remove
some unnecessary clutter.
Harald Hoyer