Archive for February, 2016

When looking at various tutorials on configuring postfix, it’s quite easy to configure a catch all for a certain domain. So any username at the said domain gets forwarded so a said maibox. However, I haven’t been able to find any article describing to do the reverse, catch a said username on any domain.

The reason for this is to catch abuse@, postmaster@, webmaster@ etc. any domain on my servers. When going through the postfix documentation another time I realised it support regular expressions. Using regular expressions this can be fixed

put a file /etc/postfix/regexp-aliases

^webmaster@/i  destination@email.address
^postmaster@/i destination@email.address
^abuse@/i      destination@email.address

Then open /etc/postfix/ and add


to virtual_alias_maps = .

Edit 05-03-2016: added the /i to the example. Email user names are supposed to be case insensitive.

For quite some time, I haven’t been able to use wireless communication on my HP EliteBook 8530w. All wireless communications (wifi, wwan, bluetooth) are listed as Hard Blocked by rfkill.

It appears, a kernel bug was introduces with Linux 3.13. This bug is in the hp-wmi kernel module, which controls the hardware buttons, including the wireless switch

My current kernel is 4.3.3, so,we obtain the source file for the hp-wmi for this kernel :
We obtain the patch file

We apply the patch to the file

patch -p 4 < hp_wmi.patch

We put a Makefile with this file in it

obj-$(CONFIG_HP_WMI)		+= hp-wmi.o

And we comile it

make -C /lib/modules/`uname -r`/build M=$PWD

Backup the original kernel module

mv /usr/lib/modules/`uname -r`/kernel/drivers/platform/x86/hp-wmi.ko.gz /usr/lib/modules/`uname -r`/kernel/drivers/platform/x86/hp-wmi.ko.gz.bak

And put the patched version in its place.

mv ./hp-wmi.ko.gz /usr/lib/modules/`uname -r`/kernel/drivers/platform/x86/hp-wmi.ko.gz

When we press the wireless button now, rfkill reports Hard Blocked: no and we're able to use WiFi, Bluetooth and 3G again.