NAME¶

squid_selinux - Security Enhanced Linux Policy for the squid processes

DESCRIPTION¶

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

The squid processes execute with the squid_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 squid_t

ENTRYPOINTS¶

The squid_t SELinux type can be entered via the squid_exec_t file type.

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

/usr/sbin/squid, /usr/libexec/squid/cache_swap.sh

PROCESS TYPES¶

SELinux defines process types (domains) for each process running on the system

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

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

The following process types are defined for squid:

squid_t, squid_cron_t, squid_script_t

Note: semanage permissive -a squid_t can be used to make the process type squid_t permissive. SELinux does not deny access to permissive process types, but the AVC (SELinux denials) messages are still generated.

BOOLEANS¶

SELinux policy is customizable based on least access required. squid policy is extremely flexible and has several booleans that allow you to manipulate the policy and run squid with the tightest access possible.

If you want to determine whether squid can connect to all TCP ports, you must turn on the squid_connect_any boolean. Enabled by default.

setsebool -P squid_connect_any 1

If you want to determine whether squid can run as a transparent proxy, you must turn on the squid_use_tproxy boolean. Disabled by default.

setsebool -P squid_use_tproxy 1

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 daemons to write corefiles to /, you must turn on the daemons_dump_core boolean. Disabled by default.

setsebool -P daemons_dump_core 1

If you want to enable cluster mode for daemons, you must turn on the daemons_enable_cluster_mode boolean. Enabled by default.

setsebool -P daemons_enable_cluster_mode 1

If you want to allow all daemons to use tcp wrappers, you must turn on the daemons_use_tcp_wrapper boolean. Disabled by default.

setsebool -P daemons_use_tcp_wrapper 1

If you want to allow all daemons the ability to read/write terminals, you must turn on the daemons_use_tty boolean. Disabled by default.

setsebool -P daemons_use_tty 1

If you want to deny any process from ptracing or debugging any other processes, you must turn on the deny_ptrace boolean. Enabled by default.

setsebool -P deny_ptrace 1

If you want to allow any process to mmap any file on system with attribute file_type, you must turn on the domain_can_mmap_files boolean. Enabled by default.

setsebool -P domain_can_mmap_files 1

If you want to allow all domains write to kmsg_device, while kernel is executed with systemd.log_target=kmsg parameter, you must turn on the domain_can_write_kmsg boolean. Disabled by default.

setsebool -P domain_can_write_kmsg 1

If you want to allow all domains to use other domains file descriptors, you must turn on the domain_fd_use boolean. Enabled by default.

setsebool -P domain_fd_use 1

If you want to allow all domains to have the kernel load modules, you must turn on the domain_kernel_load_modules boolean. Disabled by default.

setsebool -P domain_kernel_load_modules 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 enable reading of urandom for all domains, you must turn on the global_ssp boolean. Disabled by default.

setsebool -P global_ssp 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. Disabled by default.

setsebool -P nscd_use_shm 1

PORT TYPES¶

SELinux defines port types to represent TCP and UDP ports.

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 squid policy is very flexible allowing users to setup their squid processes in as secure a method as possible.

The following port types are defined for squid:

squid_port_t

Default Defined Ports: tcp 3128,3401,4827 udp 3401,4827

MANAGED FILES¶

The SELinux process type squid_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.

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/cpglockd.pid
/var/run/corosync.pid
/var/run/rgmanager.pid
/var/run/cluster/rgmanager.sk

faillog_t

/var/log/btmp.*
/var/log/faillog.*
/var/log/tallylog.*
/var/run/faillock(/.*)?

krb5_host_rcache_t

/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/ostree/deploy/.*-atomic.*/deploy(/.*)?
/
/initrd

security_t

/selinux

squid_cache_t

/var/squidGuard(/.*)?
/var/lib/ssl_db(/.*)?
/var/lightsquid(/.*)?
/var/cache/squid(/.*)?
/var/spool/squid(/.*)?
/etc/squid/ssl_db(/.*)?

squid_log_t

/var/log/squid(/.*)?
/var/log/squidGuard(/.*)?

squid_tmp_t

squid_tmpfs_t

squid_var_run_t

/var/run/squid.*

FILE CONTEXTS¶

SELinux requires files to have an extended attribute to define the file type.

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 squid policy is very flexible allowing users to setup their squid processes in as secure a method as possible.

EQUIVALENCE DIRECTORIES

squid policy stores data with multiple different file context types under the /var/log/squid directory. If you would like to store the data in a different directory you can use the semanage command to create an equivalence mapping. If you wanted to store this data under the /srv dirctory you would execute the following command:

semanage fcontext -a -e /var/log/squid /srv/squid
restorecon -R -v /srv/squid

STANDARD FILE CONTEXT

SELinux defines the file context types for the squid, 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 squid_var_run_t '/srv/mysquid_content(/.*)?'
restorecon -R -v /srv/mysquid_content

Note: SELinux often uses regular expressions to specify labels that match multiple files.

The following file types are defined for squid:

squid_cache_t

- Set files with the squid_cache_t type, if you want to store the files under the /var/cache directory.

Paths:

/var/squidGuard(/.*)?, /var/lib/ssl_db(/.*)?, /var/lightsquid(/.*)?, /var/cache/squid(/.*)?, /var/spool/squid(/.*)?, /etc/squid/ssl_db(/.*)?

squid_conf_t

- Set files with the squid_conf_t type, if you want to treat the files as squid configuration data, usually stored under the /etc directory.

Paths:

/etc/squid(/.*)?, /etc/lightsquid(/.*)?, /usr/share/squid(/.*)?

squid_content_t

- Set files with the squid_content_t type, if you want to treat the files as squid content.

squid_cron_exec_t

- Set files with the squid_cron_exec_t type, if you want to transition an executable to the squid_cron_t domain.

squid_exec_t

- Set files with the squid_exec_t type, if you want to transition an executable to the squid_t domain.

Paths:

/usr/sbin/squid, /usr/libexec/squid/cache_swap.sh

squid_htaccess_t

- Set files with the squid_htaccess_t type, if you want to treat the file as a squid access file.

squid_initrc_exec_t

- Set files with the squid_initrc_exec_t type, if you want to transition an executable to the squid_initrc_t domain.

squid_log_t

- Set files with the squid_log_t type, if you want to treat the data as squid log data, usually stored under the /var/log directory.

Paths:

/var/log/squid(/.*)?, /var/log/squidGuard(/.*)?

squid_ra_content_t

- Set files with the squid_ra_content_t type, if you want to treat the files as squid read/append content.

squid_rw_content_t

- Set files with the squid_rw_content_t type, if you want to treat the files as squid read/write content.

squid_script_exec_t

- Set files with the squid_script_exec_t type, if you want to transition an executable to the squid_script_t domain.

Paths:

/usr/share/lightsquid/cgi(/.*)?, /usr/lib/squid/cachemgr.cgi

squid_tmp_t

- Set files with the squid_tmp_t type, if you want to store squid temporary files in the /tmp directories.

squid_tmpfs_t

- Set files with the squid_tmpfs_t type, if you want to store squid files on a tmpfs file system.

squid_var_run_t

- Set files with the squid_var_run_t type, if you want to store the squid 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.

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.

AUTHOR¶

This manual page was auto-generated using sepolicy manpage .

SEE ALSO¶

selinux(8), squid(8), semanage(8), restorecon(8), chcon(1), sepolicy(8) , setsebool(8), squid_cron_selinux(8), squid_script_selinux(8)