dhcpc_selinux(8)

✨ dhcpc_selinux(8) — the glow-up guide to SELinux for dhcpc ✨

Okay bestie, so like, this is the dhcpc_selinux(8) manual page! It's all about the Security Enhanced Linux Policy for the dhcpc processes. Fr fr, it's giving "I'm here to keep your DHCP client from doing sketchy stuff" and honestly? Iconic. 💅

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🌸 NAME 🌸

dhcpc_selinux — Security Enhanced Linux Policy for the dhcpc processes

🎀 DESCRIPTION 🎀

Security-Enhanced Linux secures the dhcpc processes via flexible mandatory access control. Periodt.

The dhcpc processes execute with the dhcpc_t SELinux type. You can check if you have these processes running by executing the ps command with the -Z qualifier.

For example (lowkey the cutest little check-in):

ps -eZ | grep dhcpc_t

🦋 ENTRYPOINTS 🦋

The dhcpc_t SELinux type can be entered via the dhcpc_exec_t file type. That's the vibe check for executables, iykyk.

The default entrypoint paths for the dhcpc_t domain are the following:

/usr/bin/dhclient.*, /usr/bin/dhcdbd, /usr/bin/dhcpcd

👑 PROCESS TYPES 👑

SELinux defines process types (domains) for each process running on the system. Yes bestie, every single one gets its own little category. Main character energy for processes, honestly.

You can see the context of a process using the -Z option to ps.

Policy governs the access confined processes have to files. SELinux dhcpc policy is very flexible allowing users to setup their dhcpc processes in as secure a method as possible. We love a flexible queen! ✨

The following process types are defined for dhcpc:

dhcpc_t

Note: semanage permissive -a dhcpc_t can be used to make the process type dhcpc_t permissive. SELinux does not deny access to permissive process types, but the AVC (SELinux denials) messages are still generated. It's literally like "you're on time-out but we're still logging everything you do." 😭

💖 BOOLEANS 💖

SELinux policy is customizable based on least access required. dhcpc policy is extremely flexible and has several booleans that allow you to manipulate the policy and run dhcpc with the tightest access possible. Slay for granular control! 🎀

• dhcpc_exec_iptables — If you want to allow dhcpc client applications to execute iptables commands, you must turn on the dhcpc_exec_iptables boolean. Disabled by default.

setsebool -P dhcpc_exec_iptables 1

• daemons_dontaudit_scheduling — If you want to dontaudit all daemons scheduling requests (setsched, sys_nice), you must turn on the daemons_dontaudit_scheduling boolean. Enabled by default.

setsebool -P daemons_dontaudit_scheduling 1

• fips_mode — If you want to allow all domains to execute in fips_mode, you must turn on the fips_mode boolean. Enabled by default.

setsebool -P fips_mode 1

• nis_enabled — If you want to allow system to run with NIS, you must turn on the nis_enabled boolean. Disabled by default.

setsebool -P nis_enabled 1

🌈 PORT TYPES 🌈

SELinux defines port types to represent TCP and UDP ports. No cap, they got types for everything.

You can see the types associated with a port by using the following command:

semanage port -l

Policy governs the access confined processes have to these ports. SELinux dhcpc policy is very flexible allowing users to setup their dhcpc processes in as secure a method as possible. Same energy as before, still iconic. 💅

The following port types are defined for dhcpc:

dhcpc_port_t

Default Defined Ports:

• tcp 68,546,5546
• udp 68,546,5546

💜 MANAGED FILES 💜

The SELinux process type dhcpc_t can manage files labeled with the following file types. The paths listed are the default paths for these file types. Note the processes UID still need to have DAC permissions. (DAC is like, the regular permission system, SELinux is the extra sprinkle on top bestie.) 🧚

NetworkManager_var_lib_t

/var/lib/wicd(/.*)?
/var/lib/NetworkManager(/.*)?
/etc/dhcp/wired-settings.conf
/etc/wicd/wired-settings.conf
/etc/dhcp/manager-settings.conf
/etc/wicd/manager-settings.conf
/etc/dhcp/wireless-settings.conf
/etc/wicd/wireless-settings.conf

NetworkManager_var_run_t

/run/teamd(/.*)?
/run/nm-xl2tpd.conf.*
/run/nm-dhclient.*
/run/NetworkManager(/.*)?
/run/wpa_supplicant(/.*)?
/run/wicd.pid
/run/NetworkManager.pid
/run/nm-dns-dnsmasq.conf
/run/wpa_supplicant-global

chronyd_var_run_t

/run/chrony(/.*)?
/run/chronyd(/.*)?
/run/chrony-dhcp(/.*)?
/run/chrony-helper(/.*)?
/run/chronyd.pid
/run/chronyd.sock

cluster_conf_t

/etc/cluster(/.*)?

cluster_var_lib_t

/var/lib/pcsd(/.*)?
/var/lib/cluster(/.*)?
/var/lib/openais(/.*)?
/var/lib/pengine(/.*)?
/var/lib/corosync(/.*)?
/usr/lib/heartbeat(/.*)?
/var/lib/heartbeat(/.*)?
/var/lib/pacemaker(/.*)?

cluster_var_run_t

/run/crm(/.*)?
/run/cman_.*
/run/rsctmp(/.*)?
/run/aisexec.*
/run/heartbeat(/.*)?
/run/pcsd-ruby.socket
/run/corosync-qnetd(/.*)?
/run/corosync-qdevice(/.*)?
/run/pcsd.socket
/run/corosync.pid
/run/cpglockd.pid
/run/rgmanager.pid
/run/cluster/rgmanager.sk

dhcpc_state_t

/var/lib/dhcp3?/dhclient.*
/var/lib/dhcpcd(/.*)?
/var/lib/dhclient(/.*)?
/var/lib/wifiroamd(/.*)?

dhcpc_var_run_t

/run/dhcpcd(/.*)?
/run/dhclient.*

initrc_var_run_t

/run/sysconfig(/.*)?
/run/utmp
/run/keymap
/run/numlock-on
/run/setleds-on
/run/runlevel.dir
/run/setmixer_flag
/run/bootsplashctl

krb5_host_rcache_t

/var/tmp/krb5_0.rcache2
/var/cache/krb5rcache(/.*)?
/var/tmp/nfs_0
/var/tmp/DNS_25
/var/tmp/host_0
/var/tmp/imap_0
/var/tmp/HTTP_23
/var/tmp/HTTP_48
/var/tmp/ldap_55
/var/tmp/ldap_487
/var/tmp/ldapmap1_0

root_t

/sysroot/.aleph-version.json
/sysroot/ostree/deploy/.*-atomic/deploy(/.*)?
/
/initrd
/var/lib/ntp

systemd_passwd_var_run_t

/run/systemd/ask-password(/.*)?
/run/systemd/ask-password-block(/.*)?

virt_driver_var_run

(no default paths listed in the original, bestie — it's just vibes)

virt_lxc_var_run_t

/run/libvirt/lxc(/.*)?
/run/libvirt-sandbox(/.*)?
/run/virtlxcd.pid
/run/libvirt/virtlxcd-sock
/run/libvirt/virtlxcd-sock-ro
/run/libvirt/virtlxcd-admin-sock

virt_var_run_t

/run/vdsm(/.*)?
/var/vdsm(/.*)?
/run/libvirt(/.*)?
/run/libvirtd.pid
/run/qemu-pr-helper.sock
/run/libvirt/libvirt-sock

🍓 FILE CONTEXTS 🍓

SELinux requires files to have an extended attribute to define the file type. It's like every file has a little name tag, so cute. 🎀

You can see the context of a file using the -Z option to ls.

Policy governs the access confined processes have to these files. SELinux dhcpc policy is very flexible allowing users to setup their dhcpc processes in as secure a method as possible.

STANDARD FILE CONTEXT

SELinux defines the file context types for the dhcpc, if you wanted to store files with these types in a different paths, you need to execute the semanage command to specify alternate labeling and then use restorecon to put the labels on disk.

semanage fcontext -a -t dhcpc_exec_t '/srv/dhcpc/content(/.*)?'
restorecon -R -v /srv/mydhcpc_content

Note: SELinux often uses regular expressions to specify labels that match multiple files. Regex said "I contain multitudes." 😭

The following file types are defined for dhcpc:

• dhcpc_exec_t — Set files with the dhcpc_exec_t type, if you want to transition an executable to the dhcpc_t domain.

Paths:

/usr/bin/dhclient.*, /usr/bin/dhcdbd, /usr/bin/dhcpcd

• dhcpc_helper_exec_t — Set files with the dhcpc_helper_exec_t type, if you want to transition an executable to the dhcpc_helper_t domain.
• dhcpc_state_t — Set files with the dhcpc_state_t type, if you want to treat the files as dhcpc state data.

Paths:

/var/lib/dhcp3?/dhclient.*, /var/lib/dhcpcd(/.*)?,
/var/lib/dhclient(/.*)?, /var/lib/wifiroamd(/.*)?

• dhcpc_tmp_t — Set files with the dhcpc_tmp_t type, if you want to store dhcpc temporary files in the /tmp directories.
• dhcpc_var_run_t — Set files with the dhcpc_var_run_t type, if you want to store the dhcpc files under the /run or /var/run directory.

Paths:

/run/dhcpcd(/.*)?, /run/dhclient.*

Note: File context can be temporarily modified with the chcon command. If you want to permanently change the file context you need to use the semanage fcontext command. This will modify the SELinux labeling database. You will need to use restorecon to apply the labels. Temporary vs permanent — know the difference bestie, it's giving "don't @ me when your labels disappear on reboot." 💀

🔥 COMMANDS 🔥

• semanage fcontext can also be used to manipulate default file context mappings.
• semanage permissive can also be used to manipulate whether or not a process type is permissive.
• semanage module can also be used to enable/disable/install/remove policy modules.
• semanage port can also be used to manipulate the port definitions.
• semanage boolean can also be used to manipulate the booleans.
• system-config-selinux is a GUI tool available to customize SELinux policy settings. (A GUI! For when you want to point and click instead of type, and honestly? Valid.) 🫶

⭐ AUTHOR ⭐

This manual page was auto-generated using sepolicy manpage. (Not me being auto-generated and still serving looks. 💅)

🦋 SEE ALSO 🦋

selinux(8), dhcpc(8), semanage(8), restorecon(8), chcon(1), sepolicy(8), setsebool(8)

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Alright bestie, that's the whole page! This one is from the dhcpc manual, version 26-10-06, dated 26-10-06 — so like, go forth and SELinux responsibly. Stay slay, stay secure, and remember: mandatory access control is just boundaries, and boundaries are hot. 🎀✨💖