Introduction to Avahi
The Avahi package is a system
which facilitates service discovery on a local network.
![[Note]](../images/note.png)
Note
Development versions of BLFS may not build or run some packages
properly if LFS or dependencies have been updated since the most
recent stable versions of the books.
Package Information
Additional Downloads
Avahi Dependencies
Required
GLib-2.84.4 (GObject Introspection recommended)
Recommended
GTK-3.24.50 and libdaemon-0.14
Optional
D-Bus Python-1.4.0, libevent-2.1.12,
Doxygen-1.14.0, GTK+-2
(deprecated), and xmltoman (for
generating documentation)
Installation of Avahi
There should be a dedicated user and group to take control of the
avahi-daemon daemon
after it is started. Issue the following commands as the
root user:
groupadd -fg 84 avahi &&
useradd -c "Avahi Daemon Owner" -d /run/avahi-daemon -u 84 \
-g avahi -s /bin/false avahi
There should also be a dedicated privileged access group for
Avahi clients. Issue the following
command as the root user:
groupadd -fg 86 netdev
Fix a regression that results in a race condition when IPv6 is in
use and multiple network adapters are present on the system:
patch -Np1 -i ../avahi-0.8-ipv6_race_condition_fix-1.patch
Fix a security vulnerability in avahi-daemon:
sed -i '426a if (events & AVAHI_WATCH_HUP) { \
client_free(c); \
return; \
}' avahi-daemon/simple-protocol.c
Install Avahi by running the
following commands:
./configure \
--prefix=/usr \
--sysconfdir=/etc \
--localstatedir=/var \
--disable-static \
--disable-libevent \
--disable-mono \
--disable-monodoc \
--disable-python \
--disable-qt3 \
--disable-qt4 \
--disable-qt5 \
--enable-core-docs \
--with-distro=none \
--with-dbus-system-address='unix:path=/run/dbus/system_bus_socket' &&
make
This package does not come with a test suite.
Now, as the root user:
make install
Command Explanations
--disable-static: This
switch prevents installation of static versions of the libraries.
--disable-libevent: This
parameter disables the use of libevent-2.1.12. Remove if you have it
installed.
--disable-mono: This
parameter disables the Mono
bindings.
--disable-monodoc: This
parameter disables documentation for the Mono bindings.
--disable-python: This
parameter disables the scripts that depend on Python. It also allows a regular install to
complete successfully.
--disable-qt3: This
parameter disables the attempt to build the obsolete Qt3 portions of the package.
--disable-qt4: This
parameter disables the attempt to build the obsolete Qt4Core portions of the package.
--enable-core-docs: This
parameter enables the building of documentation.
--with-distro=none: There
is an obsolete boot script in the distribution for LFS. This option
disables it.
--with-dbus-system-address=: This
option prevents the package from referring to the deprecated
/var/run directory.
--disable-dbus: This parameter disables
the use of D-Bus.
--disable-gtk: This parameter disables
the use of GTK+2.
--disable-gtk3: This parameter disables
the use of GTK+3.
--disable-qt5: This parameter disables
the use of Qt5, and allows
building without it.
--disable-libdaemon: This parameter
disables the use of libdaemon. If
you use this option, avahi-daemon won't be built.
--enable-tests: This option enables the
building of tests and examples.
--enable-compat-howl: This option
enables the compatibility layer for HOWL.
--enable-compat-libdns_sd: This option
enables the compatibility layer for libdns_sd.
Configuring avahi
Boot Script
The avahi-daemon
will conflict with systemd-resolved under the
default configuration if both are running simultaneously on a
system because both will act as a Multicast DNS resolver and
responder. If you must run the Avahi daemon (the BLFS editors
don't recommend to do that unless you really need its
functionality), disable the Multicast DNS support of systemd-resolved and enable the
previously installed systemd unit by running the following
command as the root user:
mkdir -pv /etc/systemd/resolved.conf.d &&
cat > /etc/systemd/resolved.conf.d/no-mdns.conf << EOF &&
[Resolve]
MulticastDNS=no
EOF
systemctl enable avahi-daemon
To start the avahi-dnsconfd daemon at boot,
enable the previously installed systemd unit by running the
following command as the root
user (note that the following command will also implicitly enable
avahi-daemon, so if
you are running it, you need to make sure you've disabled the
systemd-resolved
Multicast DNS support as mentioned above):
systemctl enable avahi-dnsconfd