X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=man%2Fsystemd.exec.xml;h=707d582b4f8c9537b78aead30ebc5a9539e11b5f;hp=22f076870f6f777ca3cbedf70e70d24b916c1471;hb=06b643e7f5a3b79005dd57497897ab7255fe3659;hpb=b8bde11658366290521e3d03316378b482600323 diff --git a/man/systemd.exec.xml b/man/systemd.exec.xml index 22f076870..707d582b4 100644 --- a/man/systemd.exec.xml +++ b/man/systemd.exec.xml @@ -103,7 +103,7 @@ directory path. Sets the root directory for executed processes, with the - chroot2 + chroot2 system call. If this is used, it must be ensured that the process and all its auxiliary files are available in @@ -304,7 +304,7 @@ See - environ7 + environ7 for details about environment variables. @@ -365,39 +365,47 @@ , , or - . If - is selected, - standard input will be connected to + . + + If is + selected, standard input will be + connected to /dev/null, i.e. all read attempts by the process - will result in immediate EOF. If - is selected, - standard input is connected to a TTY - (as configured by + will result in immediate EOF. + + If is + selected, standard input is connected + to a TTY (as configured by TTYPath=, see below) and the executed process becomes the controlling process of the terminal. If the terminal is already - being controlled by another process, the - executed process waits until the current - controlling process releases the - terminal. - - is similar to , - but the executed process is forcefully - and immediately made the controlling + being controlled by another process, + the executed process waits until the + current controlling process releases + the terminal. + + is similar + to , but the + executed process is forcefully and + immediately made the controlling process of the terminal, potentially removing previous controlling processes from the - terminal. is + terminal. + + is similar to but if the terminal already has a controlling process start-up of the executed - process fails. The - option is only - valid in socket-activated services, - and only when the socket configuration - file (see + process fails. + + The + option is only valid in + socket-activated services, and only + when the socket configuration file + (see systemd.socket5 for details) specifies a single socket only. If this option is set, standard @@ -407,7 +415,9 @@ with daemons designed for use with the traditional inetd8 - daemon. This setting defaults to + daemon. + + This setting defaults to . @@ -418,56 +428,84 @@ of , , , + , , , - , + , , - , - or - . If set to - , the file - descriptor of standard input is - duplicated for standard output. If set - to , standard - output will be connected to + or + . + + + duplicates the file descriptor of + standard input for standard + output. + + connects + standard output to /dev/null, i.e. everything written to it will be - lost. If set to , - standard output will be connected to a - tty (as configured via + lost. + + connects + standard output to a tty (as + configured via TTYPath=, see below). If the TTY is used for output only, the executed process will not become the controlling process of the terminal, and will not fail or wait for other processes to release the - terminal. - connects standard output to the - syslog3 - system syslog - service. - connects it with the kernel log buffer - which is accessible via - dmesg1. - connects it with the journal which is - accessible via - journalctl1 - (Note that everything that is written - to syslog or kmsg is implicitly stored - in the journal as well, those options - are hence supersets of this - one). , - and - work - similarly but copy the output to the - system console as - well. connects - standard output to a socket from - socket activation, semantics are - similar to the respective option of - StandardInput=. - This setting defaults to the value set - with + terminal. + + + connects standard output with the + journal which is accessible via + journalctl1. + Note that everything that is written + to syslog or kmsg (see below) is + implicitly stored in the journal as + well, the specific two options listed + below are hence supersets of this + one. + + connects + standard output to the syslog3 + system syslog service, in addition to + the journal. Note that the journal + daemon is usually configured to + forward everything it receives to + syslog anyway, in which case this + option is no different from + . + + connects + standard output with the kernel log + buffer which is accessible via + dmesg1, + in addition to the journal. The + journal daemon might be configured to + send all logs to kmsg anyway, in which + case this option is no different from + . + + , + and + work in + a similar way as the three options + above but copy the output to the + system console as well. + + connects + standard output to a socket acquired + via socket activation. The semantics + are similar to the same option of + StandardInput=. + + This setting defaults to the + value set with in systemd-system.conf5, @@ -568,7 +606,7 @@ , or . See - syslog3 + syslog3 for details. This option is only useful when StandardOutput= or @@ -590,7 +628,7 @@ , , . See - syslog3 + syslog3 for details. This option is only useful when StandardOutput= or @@ -687,7 +725,7 @@ User= setting. If not set, no PAM session will be opened for the executed processes. See - pam8 + pam8 for details. @@ -698,7 +736,7 @@ capabilities to include in the capability bounding set for the executed process. See - capabilities7 + capabilities7 for details. Takes a whitespace-separated list of capability names as read by cap_from_name3, @@ -739,7 +777,7 @@ SecureBits= Controls the secure bits set for the executed process. See - capabilities7 + capabilities7 for details. Takes a list of strings: , , @@ -757,14 +795,14 @@ Capabilities= Controls the - capabilities7 + capabilities7 set for the executed process. Take a capability string describing the effective, permitted and inherited capability sets as documented in cap_from_text3. Note that these capability sets are - usually influenced by the capabilities + usually influenced (and filtered) by the capabilities attached to the executed file. Due to that CapabilityBoundingSet= @@ -777,8 +815,8 @@ ReadOnlyDirectories= InaccessibleDirectories= - Sets up a new - file system namespace for executed + Sets up a new file + system namespace for executed processes. These options may be used to limit access a process might have to the main file system @@ -799,16 +837,14 @@ processes inside the namespace. Note that restricting access with these options does not extend to submounts - of a directory. You must list - submounts separately in these settings - to ensure the same limited - access. These options may be specified + of a directory that are created later + on. These options may be specified more than once in which case all directories listed will have limited access from within the namespace. If the empty string is assigned to this - option, the specific list is reset, and - all prior assignments have no + option, the specific list is reset, + and all prior assignments have no effect. Paths in ReadOnlyDirectories= @@ -934,6 +970,67 @@ accessible). + + ProtectSystem= + + Takes a boolean + argument or + full. If true, + mounts the /usr + directory read-only for processes + invoked by this unit. If set to + full, the + /etc directory is mounted + read-only, too. This setting ensures + that any modification of the vendor + supplied operating system (and + optionally its configuration) is + prohibited for the service. It is + recommended to enable this setting for + all long-running services, unless they + are involved with system updates or + need to modify the operating system in + other ways. Note however that + processes retaining the CAP_SYS_ADMIN + capability can undo the effect of this + setting. This setting is hence + particularly useful for daemons which + have this capability removed, for + example with + CapabilityBoundingSet=. Defaults + to off. + + + + ProtectHome= + + Takes a boolean + argument or + read-only. If true, + the directories + /home and + /run/user are + made inaccessible and empty for + processes invoked by this unit. If set + to read-only, the + two directories are made read-only + instead. It is recommended to enable + this setting for all long-running + services (in particular network-facing + ones), to ensure they cannot get access + to private user data, unless the + services actually require access to + the user's private data. Note however + that processes retaining the + CAP_SYS_ADMIN capability can undo the + effect of this setting. This setting + is hence particularly useful for + daemons which have this capability + removed, for example with + CapabilityBoundingSet=. Defaults + to off. + + MountFlags= @@ -962,12 +1059,14 @@ namespace. Note that means that file systems mounted on the host might stay - mounted continously in the unit's + mounted continuously in the unit's namespace, and thus keep the device busy. Note that the file system namespace related options (PrivateTmp=, PrivateDevices=, + ProtectSystem=, + ProtectHome=, ReadOnlyDirectories=, InaccessibleDirectories= and @@ -1275,7 +1374,7 @@ /, i.e. must refer to simple directories to create or remove. This is particularly useful - for unpriviliges daemons that cannot + for unprivileged daemons that cannot create runtime directories in /run due to lack of privileges, and to make sure the @@ -1411,7 +1510,7 @@ or StandardError=tty). See - termcap5. + termcap5. @@ -1427,7 +1526,7 @@ systemd.setenv= (see systemd1). Additional variables may also be set through PAM, - cf. pam_env8. + cf. pam_env8. @@ -1445,7 +1544,7 @@ systemd.resource-control5, systemd.directives7, tmpfiles.d5, - exec3 + exec3