Security-Enhanced Linux secures the dnsmasq processes via flexible mandatory access control.
The dnsmasq processes execute with the dnsmasq_t SELinux type. You can check if you have these processes running by executing the ps command with the -Z qualifier.
For example:
ps -eZ | grep dnsmasq_t
The dnsmasq_t SELinux type can be entered via the dnsmasq_exec_t file type.
The default entrypoint paths for the dnsmasq_t domain are the following:
You can see the context of a process using the -Z option to psP Policy governs the access confined processes have to files. SELinux dnsmasq policy is very flexible allowing users to setup their dnsmasq processes in as secure a method as possible.
The following process types are defined for dnsmasq:
dnsmasq_t
Note: semanage permissive -a dnsmasq_t can be used to make the process type dnsmasq_t permissive. SELinux does not deny access to permissive process types, but the AVC (SELinux denials) messages are still generated.
If you want to allow users to resolve user passwd entries directly from ldap rather then using a sssd server, you must turn on the authlogin_nsswitch_use_ldap boolean. Disabled by default.
setsebool -P authlogin_nsswitch_use_ldap 1
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
If you want to allow confined applications to run with kerberos, you must turn on the kerberos_enabled boolean. Enabled by default.
setsebool -P kerberos_enabled 1
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
If you want to allow confined applications to use nscd shared memory, you must turn on the nscd_use_shm boolean. Enabled by default.
setsebool -P nscd_use_shm 1
The SELinux process type dnsmasq_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.
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
/var/run/teamd(/.*)?
/var/run/nm-xl2tpd.conf.*
/var/run/nm-dhclient.*
/var/run/NetworkManager(/.*)?
/var/run/wpa_supplicant(/.*)?
/var/run/wicd.pid
/var/run/NetworkManager.pid
/var/run/nm-dns-dnsmasq.conf
/var/run/wpa_supplicant-global
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
/var/run/crm(/.*)?
/var/run/cman_.*
/var/run/rsctmp(/.*)?
/var/run/aisexec.*
/var/run/heartbeat(/.*)?
/var/run/corosync-qnetd(/.*)?
/var/run/corosync-qdevice(/.*)?
/var/run/corosync.pid
/var/run/cpglockd.pid
/var/run/rgmanager.pid
/var/run/cluster/rgmanager.sk
crond_var_run_t
/var/run/.*cron.*
/var/run/crond?.pid
/var/run/crond?.reboot
/var/run/atd.pid
/var/run/fcron.pid
/var/run/fcron.fifo
/var/run/anacron.pid
dnsmasq_lease_t
/var/lib/dnsmasq(/.*)?
/var/lib/misc/dnsmasq.leases
dnsmasq_tmp_t
dnsmasq_var_run_t
/var/run/dnsmasq.*
/var/run/libvirt/network(/.*)?
mnt_t
/mnt(/[^/]*)?
/mnt(/[^/]*)?
/rhev(/[^/]*)?
/rhev/[^/]*/.*
/media(/[^/]*)?
/media(/[^/]*)?
/media/.hal-.*
/var/run/media(/[^/]*)?
/afs
/net
/misc
/rhev
neutron_var_lib_t
/var/lib/neutron(/.*)?
/var/lib/quantum(/.*)?
root_t
/sysroot/ostree/deploy/.*-atomic/deploy(/.*)?
/
/initrd
virt_var_lib_t
/var/lib/oz(/.*)?
/var/lib/libvirt(/.*)?
You can see the context of a file using the -Z option to lsP Policy governs the access confined processes have to these files. SELinux dnsmasq policy is very flexible allowing users to setup their dnsmasq processes in as secure a method as possible.
STANDARD FILE CONTEXT
SELinux defines the file context types for the dnsmasq, if you wanted to store files with these types in a diffent paths, you need to execute the semanage command to sepecify alternate labeling and then use restorecon to put the labels on disk.
semanage fcontext -a -t dnsmasq_tmp_t '/srv/mydnsmasq_content(/.*)?'
restorecon -R -v /srv/mydnsmasq_content
Note: SELinux often uses regular expressions to specify labels that match multiple files.
The following file types are defined for dnsmasq:
dnsmasq_etc_t
- Set files with the dnsmasq_etc_t type, if you want to store dnsmasq files in the /etc directories.
dnsmasq_exec_t
- Set files with the dnsmasq_exec_t type, if you want to transition an executable to the dnsmasq_t domain.
dnsmasq_initrc_exec_t
- Set files with the dnsmasq_initrc_exec_t type, if you want to transition an executable to the dnsmasq_initrc_t domain.
dnsmasq_lease_t
- Set files with the dnsmasq_lease_t type, if you want to treat the files as dnsmasq lease data.
dnsmasq_tmp_t
- Set files with the dnsmasq_tmp_t type, if you want to store dnsmasq temporary files in the /tmp directories.
dnsmasq_unit_file_t
- Set files with the dnsmasq_unit_file_t type, if you want to treat the files as dnsmasq unit content.
dnsmasq_var_log_t
- Set files with the dnsmasq_var_log_t type, if you want to treat the data as dnsmasq var log data, usually stored under the /var/log directory.
dnsmasq_var_run_t
- Set files with the dnsmasq_var_run_t type, if you want to store the dnsmasq files under the /run or /var/run directory.
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.
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 boolean can also be used to manipulate the booleans
system-config-selinux is a GUI tool available to customize SELinux policy settings.