dhcpcd is an implementation of the DHCP client specified in RFC2131. A DHCP client is useful for connecting your computer to a network which uses DHCP to assign network addresses. dhcpcd strives to be a fully featured, yet very lightweight DHCP client.
This package is known to build and work properly using an LFS 11.3 platform.
Download (HTTP): https://roy.marples.name/downloads/dhcpcd/dhcpcd-9.4.1.tar.xz
Download MD5 sum: 2b2f46648bc96979f96127f0e0e07d9b
Download size: 251 KB
Estimated disk space required: 3.6 MB (with tests)
Estimated build time: less than 0.1 SBU (with tests)
LLVM-15.0.7 (with Clang), ntp-4.2.8p15, chronyd, and ypbind
User Notes: https://wiki.linuxfromscratch.org/blfs/wiki/dhcpcd
Recent releases of dhcpcd optionally support privilege separation. As the practical security benefits of this are unclear for a program like dhcpcd and the setup is more complicated, the book currently defaults to disable it.
If you however would like to use privilege separation, additional
installation steps are necessary to set up the proper environment.
Issue the following commands as the root user:
install -v -m700 -d /var/lib/dhcpcd &&
groupadd -g 52 dhcpcd &&
useradd -c 'dhcpcd PrivSep' \
-d /var/lib/dhcpcd \
-g dhcpcd \
-s /bin/false \
-u 52 dhcpcd &&
chown -v dhcpcd:dhcpcd /var/lib/dhcpcd
Fix a runtime error caused by a change in glibc-2.36:
sed '/Deny everything else/i SECCOMP_ALLOW(__NR_getrandom),' \
-i src/privsep-linux.c
Build dhcpcd without privilege separation by running the following command:
./configure --prefix=/usr \
--sysconfdir=/etc \
--libexecdir=/usr/lib/dhcpcd \
--dbdir=/var/lib/dhcpcd \
--runstatedir=/run \
--disable-privsep &&
make
Build dhcpcd with privilege separation by running the following commands:
./configure --prefix=/usr \
--sysconfdir=/etc \
--libexecdir=/usr/lib/dhcpcd \
--dbdir=/var/lib/dhcpcd \
--runstatedir=/run \
--privsepuser=dhcpcd &&
make
To test the results, issue: make test.
Now, as the root user:
make install
--libexecdir=/usr/lib/dhcpcd: Set a
more proper location for dhcpcd internal libraries.
--dbdir=/var/lib/dhcpcd:
The default /var/db is not
FHS-compliant
--runstatedir=/run: The
default /var/run is a symbolic link
to /run.
--with-hook=...: You can optionally
install more hooks, for example to install some configuration files
such as ntp.conf. The set of hooks is
in the dhcpcd-hooks directory in the
build tree.
--disable-privsep: Do not
use privilege separation, which is the default.
--privsepuser=dhcpcd: Use
this unprivileged user in a privilege separation setup.
--with-hook=...: You can optionally
install more hooks, for example to install some configuration files
such as ntp.conf. The set of hooks is
in the dhcpcd-hooks directory in the
build tree.
To configure dhcpcd, you need to first
install the network service script, /usr/lib/services/dhcpcd included in the
blfs-bootscripts-20230101 package (as
user root):
make install-service-dhcpcd
![[Note]](../images/note.png)
the network
service script /usr/lib/services/dhcpcd contained in
bootscripts up to blfs-bootscripts-20191204 is not compatible
with latest dhcpcd, as the location of the pidfile changed. To
work around this, issue the following command:
sed -i "s;/run/dhcpcd-;/run/dhcpcd/;g" /lib/services/dhcpcd
The default
for dhcpcd is to
set the hostname and mtu. It also overwrites /etc/resolv.conf and /etc/ntp.conf. These modifications to system
files are done by hooks which are stored in /usr/lib/dhcpcd/dhcpcd-hooks. Set up
dhcpcd by
removing or adding hooks from/to that directory. The execution
of hooks can be disabled by using the --nohook (-C)
command line option or by the nohook option in the /etc/dhcpcd.conf file.
Finally, as the
root user create the /etc/sysconfig/ifconfig.eth0 configuration file
using the following commands. Adjust appropriately for additional
interfaces:
cat > /etc/sysconfig/ifconfig.eth0 << "EOF"
ONBOOT="yes"
IFACE="eth0"
SERVICE="dhcpcd"
DHCP_START="-b -q -h ''<insert appropriate start options here>"
DHCP_STOP="-k <insert additional stop options here>"
EOF
For more information on the appropriate DHCP_START and DHCP_STOP values, examine the man page for
dhcpcd.
Although not
usual, it is possible that you need to configure dhcpcd to use a fixed ip. Here, we give an
example. As the root user create
the /etc/sysconfig/ifconfig.eth0
configuration file using the following commands. Adjust
appropriately for additional interfaces and for the actual ip and
router you need:
cat > /etc/sysconfig/ifconfig.eth0 << "EOF"
ONBOOT="yes"
IFACE="eth0"
SERVICE="dhcpcd"
DHCP_START="-b -q -S ip_address=192.168.0.10/24 -S routers=192.168.0.1"
DHCP_STOP="-k"
EOF
You can either use DNS servers in /etc/resolv.conf from another system, your
preferred servers, or just the example /etc/resolv.conf.head file below as is:
cat > /etc/resolv.conf.head << "EOF"
# OpenDNS servers
nameserver 208.67.222.222
nameserver 208.67.220.220
EOF