Beyond Linux® From Scratch (System V Edition) - Version r11.2-1338

Chapter 16. Networking Utilities

NetworkManager-1.42.0

Introduction to NetworkManager

NetworkManager is a set of co-operative tools that make networking simple and straightforward. Whether you use WiFi, wired, 3G, or Bluetooth, NetworkManager allows you to quickly move from one network to another: Once a network has been configured and joined once, it can be detected and re-joined automatically the next time it's available.

This package is known to build and work properly using an LFS 11.3 platform.

Package Information

NetworkManager Dependencies

Required

jansson-2.14 and libndp-1.8

Recommended

cURL-7.88.1, DHCP-4.4.3-P1 (client only), gobject-introspection-1.74.0, iptables-1.8.9, newt-0.52.23 (for nmtui), nss-3.88.1, Polkit-122, PyGObject-3.42.2, elogind-246.10, UPower-1.90.0, Vala-0.56.4, and wpa_supplicant-2.10 (runtime, built with D-Bus support)

Optional

BlueZ-5.66, D-Bus Python-1.3.2 (for the test suite), GnuTLS-3.8.0 (used if nss-3.88.1 is not found), GTK-Doc-1.33.2, libpsl-0.21.2, Qt-5.15.8 (for examples), ModemManager-1.18.12, Valgrind-3.20.0, dnsmasq, firewalld, libaudit, libteam, mobile-broadband-provider-info, PPP, and RP-PPPoE

User Notes: https://wiki.linuxfromscratch.org/blfs/wiki/NetworkManager

Kernel Configuration

If you wish to run the tests, check that at least the following options are enabled in the kernel configuration. Those options have been determined to be necessary, but may not be sufficient. Recompile the kernel if necessary: 

[*] Networking support--->                                [CONFIG_NET]
      Networking options--->
      [*] TCP/IP networking                               [CONFIG_INET]
      <*/M>   IP: tunelling                               [CONFIG_NET_IPIP]
      <*/M>   IP: GRE demultiplexer                       [CONFIG_NET_IPGRE_DEMUX]
      <*/M>   IP: GRE tunnels over IP                     [CONFIG_NET_IPGRE]
      <*>   The IPv6 protocol --->                        [CONFIG_IPV6]
        <*/M> IPv6: IPv6-in-IPv4 tunnel (SIT driver)      [CONFIG_IPV6_SIT]
        <*/M> IPv6: GRE tunnel                            [CONFIG_IPV6_GRE]
        [*] IPv6: Multiple Routing Tables                 [CONFIG_IPV6_MULTIPLE_TABLES]
      [*]   MPTCP:   Multipath TCP                        [CONFIG_MPTCP]
      [*]     MPTCP: IPv6 support for Multipath TCP       [CONFIG_MPTCP_IPV6]
      <*/M> 802.1Q/802.1ad VLAN Support                   [CONFIG_VLAN_8021Q]
      [*] QoS and/or fair queueing  --->                  [CONFIG_NET_SCHED]
        <*/M> Stochastic Fairness Queueing (SFQ)          [CONFIG_NET_SCH_SFQ]
        <*/M> Token Bucket Filter (TBF)                   [CONFIG_NET_SCH_TBF]
        <*/M> Fair Queue Controlled Delay AQM (FQ_CODEL)  [CONFIG_NET_SCH_FQ_CODEL]
        <*/M> Ingress/classifier-action Qdisc             [CONFIG_NET_SCH_INGRESS]
    Device Drivers --->
    [*] Network device support --->                       [CONFIG_NETDEVICES]
      [*] Network core driver support                     [CONFIG_NET_CORE]
      <*>   Bonding driver support                        [CONFIG_BONDING]
      <*>   Dummy net driver support                      [CONFIG_DUMMY]
      <*>   Ethernet team driver support --->             [CONFIG_NET_TEAM]
      <*>   MAC-VLAN support                              [CONFIG_MACVLAN]
      <*>     MAC-VLAN based tap driver                   [CONFIG_MACVTAP]
      <*>   IP-VLAN support                               [CONFIG_IPVLAN]
      <*>   Virtual eXtensible Local Area Network (VXLAN) [CONFIG_VXLAN]
      <*>   Virtual ethernet pair device                  [CONFIG_VETH]
      <*>   Virtual Routing and Forwarding (Lite)         [CONFIG_VRF]

Installation of NetworkManager

If Qt-5.15.8 is installed and the Qt based examples are desired, fix two meson.build files: 

sed -e 's/-qt4/-qt5/'              \
    -e 's/moc_location/host_bins/' \
    -i examples/C/qt/meson.build   &&

sed -e 's/Qt/&5/'                  \
    -i meson.build

Fix the python scripts so that they use Python 3: 

grep -rl '^#!.*python$' | xargs sed -i '1s/python/&3/'

Install NetworkManager by running the following commands: 

mkdir build &&
cd    build &&

CXXFLAGS+="-O2 -fPIC"            \
meson setup                      \
      --prefix=/usr              \
      --buildtype=release        \
      -Dlibaudit=no              \
      -Dlibpsl=false             \
      -Dnmtui=true               \
      -Dovs=false                \
      -Dppp=false                \
      -Dselinux=false            \
      -Dsession_tracking=elogind \
      -Dmodem_manager=false      \
      -Dsystemdsystemunitdir=no  \
      -Dsystemd_journal=false    \
      -Dqt=false                 \
      .. &&
ninja

An already active graphical session with a bus address is necessary to run the tests. To test the results, issue ninja test.

A few tests may fail, depending on enabled kernel options.

Now, as the root user: 

ninja install &&
mv -v /usr/share/doc/NetworkManager{,-1.42.0}

If you have not passed the -Ddocs=true option to meson, you can install the pregenerated manual pages with (as the root user): 

for file in $(echo ../man/*.[1578]); do
    section=${file##*.} &&
    install -vdm 755 /usr/share/man/man$section
    install -vm 644 $file /usr/share/man/man$section/
done

Still in case you have not used -Ddocs=true, the pregenerated HTML documentation can also be installed with (as the root user): 

cp -Rv ../docs/{api,libnm} /usr/share/doc/NetworkManager-1.42.0

Command Explanations

CXXFLAGS="-O2 -fPIC": These compiler options are necessary to build the Qt5 based examples.

--buildtype=release: Specify a buildtype suitable for stable releases of the package, as the default may produce unoptimized binaries.

-Ddocs=true: Use this switch to enable building man pages and documentation if GTK-Doc-1.33.2 is installed.

-Dnmtui=true: This parameter enables building nmtui.

-Dsystemdsystemunitdir=no and -Dsystemd_journal=false: systemd is not used for sysv init systems.

-Dlibpsl=false and -Dovs=false: These switches disable building with the respective libraries. Remove if you have the needed libraries installed.

-Dmodem_manager=false: This switch is required if ModemManager is not installed. Omit if you have built ModemManager and mobile-broadband-provider-info.

-Dsession_tracking=elogind: This switch is used to set elogind as the default program for session tracking.

-Dppp=false: This parameter disables PPP support in NetworkManager.

-Dlibaudit=no and -Dselinux=false: libaudit and SELinux are not used in BLFS.

-Dqt=false: disables the QT examples. Omit if you have QT available and wish to install the examples.

Configuring NetworkManager

Config Files

/etc/NetworkManager/NetworkManager.conf

Configuration Information

For NetworkManager to work, at least a minimal configuration file must be present. Such a file is not installed with make install. Issue the following command as the root user to create a minimal NetworkManager.conf file: 

cat >> /etc/NetworkManager/NetworkManager.conf << "EOF"
[main]
plugins=keyfile
EOF

This file should not be modified directly by users of the system. Instead, system specific changes should be made using configuration files in the /etc/NetworkManager/conf.d directory.

To allow polkit to manage authorizations, add the following configuration file: 

cat > /etc/NetworkManager/conf.d/polkit.conf << "EOF"
[main]
auth-polkit=true
EOF

To use something other than the built-in dhcp client (recommended if using only nmcli), use the following configuration (valid values include either dhclient or internal): 

cat > /etc/NetworkManager/conf.d/dhcp.conf << "EOF"
[main]
dhcp=dhclient
EOF

To prevent NetworkManager from updating the /etc/resolv.conf file, add the following configuration file: 

cat > /etc/NetworkManager/conf.d/no-dns-update.conf << "EOF"
[main]
dns=none
EOF

For additional configuration options, see man 5 NetworkManager.conf.

To allow regular users to configure network connections, you should add them to the netdev group, and create a polkit rule that grants access. Run the following commands as the root user: 

groupadd -fg 86 netdev &&
/usr/sbin/usermod -a -G netdev <username>

cat > /usr/share/polkit-1/rules.d/org.freedesktop.NetworkManager.rules << "EOF"
polkit.addRule(function(action, subject) {
    if (action.id.indexOf("org.freedesktop.NetworkManager.") == 0 && subject.isInGroup("netdev")) {
        return polkit.Result.YES;
    }
});
EOF

Boot Script

To automatically start the NetworkManager daemon when the system is rebooted, install the /etc/rc.d/init.d/networkmanagerbootscript from the blfs-bootscripts-20230101 package.

[Note]

Note

If using Network Manager to manage an interface, any previous configuration for that interface should be removed, and the interface brought down prior to starting Network Manager. 

make install-networkmanager

Contents

Installed Programs: NetworkManager, nmcli, nm-online, nmtui, and, symlinked to nmtui: nmtui-connect, nmtui-edit, and nmtui-hostname
Installed Libraries: libnm.so and several modules under /usr/lib/NetworkManager
Installed Directories: /etc/NetworkManager, /usr/include/libnm, /usr/lib/NetworkManager, /usr/share/doc/NetworkManager-1.42.0, /usr/share/gtk-doc/html/{libnm,NetworkManager} (if the documentation is built), and /var/lib/NetworkManager

Short Descriptions

nmcli

is a command-line tool for controlling NetworkManager and getting its status

nm-online

is an utility to determine whether you are online

nmtui

is an interactive ncurses-based user interface for nmcli

nmtui-connect

is an interactive ncurses-based user interface to activate/deactivate connections

nmtui-edit

is an interactive ncurses-based user interface to edit connections

nmtui-hostname

is an interactive ncurses-based user interface to edit the hostname

NetworkManager

is the network management daemon

libnm.so

contains functions used by NetworkManager