- control information for system audit daemon
The audit_control file contains audit control information used by auditd(1M). Each line consists of a title and a string, separated by a colon. There are no restrictions on the order of lines in the file, although some lines must appear only once. A line beginning with `#' is a comment. A line can be continued with the use of the backslash (\) convention. (See EXAMPLES.)
Directory definition lines list the directories to be used when creating audit files, in the order in which they are to be used. The format of a directory line is:
directory-name is where the audit files will be created. Any valid writable directory can be specified.
The following configuration is recommended:
where server is the name of a central machine, since audit files belonging to different servers are usually stored in separate subdirectories of a single audit directory. The naming convention normally has server be a directory on a server machine, and all clients mount /etc/security/audit/server at the same location in their local file systems. If the same server exports several different file systems for auditing, their server names will, of course, be different.
There are several other ways for audit data to be arranged: some sites may have needs more in line with storing each host's audit data in separate subdirectories. The audit structure used will depend on each individual site.
The audit threshold line specifies the percentage of free space that must be present in the file system containing the current audit file. The format of the threshold line is:
where percentage is indicates the amount of free space required. If free space falls below this threshold, the audit daemon auditd(1M) invokes the shell script audit_warn(1M). If no threshold is specified, the default is 0%.
The plugin definition line selects a plugin to be loaded by the audit daemon for processing audit records.
The format of a plugin line is:
The following keywords are defined:
The value is the pathname of the plugin. This specification is required.
The value is the maximum number of records to queue for audit data sent to the plugin. If omitted, the current hiwater mark (see the -getqctrl of auditconfig(1M)) is used. When this maximum is reached, auditd will either block or discard data, depending on the audit policy cnt. See auditconfig(1M).
A keyword with the prefix p_ is passed to the plugin defined by the value associated with the name attribute. These attributes are defined for each plugin. By convention, if the value associated with a plugin attribute is a list, the list items are separated with commas.
If pathname is a relative path (it does not start with /) the library path will be taken as relative to /usr/lib/security/$ISA. The $ISA token is replaced by an implementation-defined directory name that defines the path relative to the auditd(1M) instruction set architecture.
See audit_syslog(5) for the attributes expected for plugin: name=audit_syslog.so.
No plugin specifier is required for generation of a binary audit log. However, to set a queue size of other than the default, a plugin line with name=audit_binfile.so can be used as described in audit_binfile(5).
You must specify one or more plugins. (In the case of audit_binfile.so, use of dir: or plugin: suffices.)
The audit flags line specifies the default system audit value. This value is combined with the user audit value read from audit_user(4) to form a user's process preselection mask.
The algorithm for obtaining the process preselection mask is as follows: the audit flags from the flags: line in the audit_control file are added to the flags from the always-audit field in the user's entry in the audit_user file. The flags from the never-audit field from the user's entry in the audit_user file are then subtracted from the total:
user's process preselection mask = (flags: line + always audit flags) - never audit flags
The format of a flags line is:
where audit-flags specifies which event classes are to be audited. The character string representation of audit-flags contains a series of flag names, each one identifying a single audit class, separated by commas. A name preceded by `-' means that the class should be audited for failure only; successful attempts are not audited. A name preceded by `+' means that the class should be audited for success only; failing attempts are not audited. Without a prefix, the name indicates that the class is to be audited for both successes and failures. The special string all indicates that all events should be audited; -all indicates that all failed attempts are to be audited, and +all all successful attempts. The prefixes ^, ^-, and ^+ turn off flags specified earlier in the string (^- and ^+ for failing and successful attempts, ^ for both). They are typically used to reset flags.
The non-attributable flags line is similar to the flags line, but this one contain the audit flags that define what classes of events are audited when an action cannot be attributed to a specific user. The format of a naflags line is:
A line can be continued by appending a backslash (\).
Example 1 Sample audit_control File for Specific Host
The following is a sample /etc/security/audit_control file for the machine eggplant.
The file's contents identify server jedgar with two file systems normally used for audit data, another server, global, used only when jedgar fills up or breaks, and specifies that the warning script is run when the file systems are 80% filled. It also specifies that all logins, administrative operations are to be audited, whether or not they succeed. All failures except failures to access object attributes are to be audited.
dir: /etc/security/jedgar/eggplant dir: /etc/security/jedgar.aux/eggplant # # Last-ditch audit file system when jedgar fills up. # dir: /etc/security/global/eggplant minfree: 20 flags: lo,ad,-all,^-fm naflags: lo,ad
Example 2 Sample audit_control File for syslog and Local Storage
Shown below is a sample /etc/security/audit_control file for syslog and local storage. For the binary log, the output is all lo and ad records, all failures of class fm and any classes specified by means of audit_user(4). For syslog output, all lo records are output, only failure ad records are output, and no fm records are output. The specification for the plugin is given in two lines.
dir: /etc/security/jedgar/eggplant dir: /etc/security/jedgar.aux/eggplant # # Last-ditch audit file system when jedgar fills up. # dir: /etc/security/global/eggplant minfree: 20 flags: lo,ad,-fm naflags: lo,ad plugin: name=audit_syslog.so;p_flags=lo,+ad;\ qsize=512
Example 3 Overriding the Default Queue Size
Shown below is a sample /etc/security/audit_control file that overrides the default queue size for binary audit log file generation.
dir: /etc/security/jedgar/eggplant dir: /etc/security/jedgar.aux/eggplant # # Last-ditch audit file system when jedgar fills up. # dir: /etc/security/global/eggplant minfree: 20 flags: lo,ad,-fm naflags: lo,ad plugin: name=audit_binfile.so; qsize=256
See attributes(5) for descriptions of the following attributes:
Use of the plugin configuration line to include audit_syslog.so requires that /etc/syslog.conf be configured for audit data. See audit_syslog(5) for more details.
Configuration changes do not affect audit sessions that are currently running, as the changes do not modify a process's preselection mask. To change the preselection mask on a running process, use the –setpmask option of the auditconfig command (see auditconfig(1M)). If the user logs out and logs back in, the new configuration changes will be reflected in the next audit session.
This file is Obsolete and may be removed and replaced with equivalent functionality in a future release of Solaris.