tcsd_selinux(8)

📦
version 20250627+git412.dbf877ab7 · 7 versions
, in opensuse-leap 16.0

💅 tcsd_selinux(8) — the SELinux policy tea for tcsd 🫶

okay so bestie, this is the manual page for tcsd_selinux, from the SELinux Policy tcsd section (section 8, iykyk). it's giving "niche but iconic" and honestly we're obsessed. let's get into it ✨

🌸 NAME 🌸

tcsd_selinux — Security Enhanced Linux Policy for the tcsd processes 💖

✨ DESCRIPTION ✨

so Security-Enhanced Linux secures the tcsd processes via flexible mandatory access control. that's the whole vibe. mandatory. access. control. periodt.

the tcsd processes execute with the tcsd_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 tcsd_t

no cap, that's how you find out if your tcsd friends are in the building 🕵️‍♀️

🚪 ENTRYPOINTS 🚪

the tcsd_t SELinux type can be entered via the tcsd_exec_t file type. like, that's the door 💅

the default entrypoint paths for the tcsd_t domain are the following:

/usr/bin/tcsd

that's it. one path. main character energy honestly 👑

🧬 PROCESS TYPES 🧬

SELinux defines process types (domains) for each process running on the system. lowkey a whole taxonomy situation.

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

policy governs the access confined processes have to files. SELinux tcsd policy is very flexible, allowing users to setup their tcsd processes in as secure a method as possible. flexible and secure — we love a both/and queen 🌈

the following process types are defined for tcsd:

  • tcsd_t
💀 note: semanage permissive -a tcsd_t can be used to make the process type tcsd_t permissive. SELinux does not deny access to permissive process types, but the AVC (SELinux denials) messages are still generated. so like, it stops blocking but it's still gonna be in your notifications, ngl. it's watching 👀

🎚️ BOOLEANS 🎚️

SELinux policy is customizable based on least access required. tcsd policy is extremely flexible and has several booleans that allow you to manipulate the policy and run tcsd with the tightest access possible. tightest access possible?? we stan a minimalist ✨

  • daemons_dontaudit_scheduling — if you want to dontaudit all daemons scheduling requests (setsched, sys_nice), you must turn on this 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 this 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 this boolean. disabled by default.
setsebool -P nis_enabled 1

okay so two are on out of the box, one is off, and that's the whole boolean roster. short and sweet, we love her 🍓

🔌 PORT TYPES 🔌

SELinux defines port types to represent TCP and UDP ports. ports are like, the doors of the network world, bestie 🚪

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 tcsd policy is very flexible, allowing users to setup their tcsd processes in as secure a method as possible. yes she said it again, because it's true 💅

the following port types are defined for tcsd:

  • tcs_port_t

Default Defined Ports:

tcp 30003

one port, one protocol, one slay 🔥

📂 MANAGED FILES 📂

the SELinux process type tcsd_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. so like, SELinux says yes but your UID might still say no — both bouncers have to check your ID 🙈

  • 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
  • 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
  • tcsd_var_lib_t
/var/lib/tpm(/.*)?

that's the whole list, no skips, no cuts 🎀

🏷️ FILE CONTEXTS 🏷️

SELinux requires files to have an extended attribute to define the file type. yes, files have vibes and the vibes are stored in an xattr ✨

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 tcsd policy is very flexible, allowing users to setup their tcsd processes in as secure a method as possible. (yes bestie, third time, she's consistent 💅)

📁 STANDARD FILE CONTEXT 📁

SELinux defines the file context types for the tcsd, 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. like, moving into a new apartment but you gotta relabel all your boxes 🫶

semanage fcontext -a -t tcsd_exec_t '/srv/tcsd/content(/.*)?'
restorecon -R -v /srv/mytcsd_content
💀 note: SELinux often uses regular expressions to specify labels that match multiple files. regex girlies rise 🙈

the following file types are defined for tcsd:

  • tcsd_exec_t — set files with the tcsd_exec_t type, if you want to transition an executable to the tcsd_t domain.
  • tcsd_initrc_exec_t — set files with the tcsd_initrc_exec_t type, if you want to transition an executable to the tcsd_initrc_t domain.
  • tcsd_var_lib_t — set files with the tcsd_var_lib_t type, if you want to store the tcsd files under the /var/lib 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. so chcon is the "for now" girlie and semanage fcontext + restorecon is the "forever" girlie, periodt 💍

🛠️ 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. GUI girlies, this one's for you 💖

✍️ AUTHOR ✍️

this manual page was auto-generated using sepolicy manpage. not me being auto-generated and still serving this hard 😭💅

👀 SEE ALSO 👀

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

and that's the whole page bestie, you ate it up 💜

this little number is brought to you by tcsd, dated 26-10-06, and it lives at tcsd_selinux(8) — go read the real one too, but like, you already know everything now 🦋✨🎀

📦 where this page comes from