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36 .Op Fl m Ar mount-point
42 utility provides an interface to manipulate properties of
48 argument determines the context for
49 the rest of the arguments.
51 most of the commands related to the rule subsystem must be preceded by the
54 The following flags are common to all keywords:
55 .Bl -tag -offset indent
56 .It Fl m Ar mount-point
59 which is expected to be a
62 If this option is not specified,
70 rule subsystem provides a way for the administrator of a system to control
71 the attributes of DEVFS nodes.
72 .\" XXX devfs node? entry? what?
73 Each DEVFS mount-point has a
77 When a device driver creates a new node,
78 all the rules in the ruleset associated with each mount-point are applied
79 (see below) before the node becomes visible to the userland.
80 This permits the administrator to change the properties,
81 including the visibility,
83 For example, one might want to hide all disk nodes in a
87 Rule manipulation commands follow the
90 The following flags are common to all of the rule manipulation commands:
91 .Bl -tag -offset indent
93 Operate on the ruleset with the number
95 If this is not specified,
96 the commands operate on the ruleset currently associated with the
97 specified mount-point.
100 The following commands are recognized:
101 .Bl -tag -offset indent
102 .It Cm rule add Oo Ar rulenum Oc Ar rulespec
103 Add the rule described by
107 The rule has the number
109 if it is explicitly specified;
110 otherwise, the rule number is automatically determined by the kernel.
111 .It Cm rule apply Ar rulenum | rulespec
114 or the rule described by
119 have their conditions checked against all nodes
120 in the mount-point and the actions taken if they match.
122 Apply all the rules in the ruleset to the mount-point
123 (see above for the definition of
125 .It Cm rule del Ar rulenum
130 Delete all rules from the ruleset.
131 .It Cm rule show Op Ar rulenum
132 Display the rule number
134 or all the rules in the ruleset.
135 The output lines (one line per rule) are expected to be valid
138 Report the numbers of existing rulesets.
139 .It Cm ruleset Ar ruleset
142 as the current ruleset for the mount-point.
144 .Ss Rule Specification
145 Rules have two parts: the conditions and the actions.
146 The conditions determine which DEVFS nodes the rule matches
147 and the actions determine what should be done when a rule matches a node.
148 For example, a rule can be written that sets the GID to
150 for all devices of type tape.
151 If the first token of a rule specification is a single dash
153 rules are read from the standard input and the rest of the specification
156 The following conditions are recognized.
157 Conditions are ANDed together when matching a device;
158 if OR is desired, multiple rules can be written.
159 .Bl -tag -offset indent
160 .It Cm path Ar pattern
161 Matches any node with a path that matches
163 which is interpreted as a
166 .It Cm type Ar devtype
167 Matches any node that is of type
170 .Cm disk , mem , tape
175 The following actions are recognized.
176 Although there is no explicit delimiter between conditions and actions,
177 they may not be intermixed.
178 .Bl -tag -offset indent
180 Set the GID of the node to
182 which may be a group name
188 Nodes may later be revived manually with
193 .It Cm include Ar ruleset
194 Apply all the rules in ruleset number
197 This does not necessarily result in any changes to the node
198 (e.g., if none of the rules in the included ruleset match).
199 Include commands in the referenced
202 .It Cm mode Ar filemode
205 which is interpreted as in
210 which may be a user name
217 .Sh IMPLEMENTATION NOTES
218 Rulesets are created by the kernel at the first reference
219 and destroyed when the last reference disappears.
220 E.g., a ruleset is created when a rule is added to it or when it is set
221 as the current ruleset for a mount-point, and
222 a ruleset is destroyed when the last rule in it is deleted
223 and no other references to it exist
224 (i.e., it is not included by any rules and it is not the current ruleset
225 for any mount-point).
227 Ruleset number 0 is the default ruleset for all new mount-points.
228 It is always empty, cannot be modified or deleted, and does not show up
232 Rules and rulesets are unique to the entire system,
233 not a particular mount-point.
236 will return the same information regardless of the mount-point specified with
238 The mount-point is only relevant when changing what its current ruleset is
239 or when using one of the apply commands.
242 .It Pa /etc/defaults/devfs.rules
246 .It Pa /etc/devfs.rules
249 configuration file. Rulesets in here override those in
250 .Pa /etc/defaults/devfs.rules
251 with the same ruleset number, otherwise the two files are effectively merged.
252 .It Pa /etc/devfs.conf
256 .It Pa /usr/share/examples/etc/devfs.conf
262 When the system boots,
263 the only ruleset that exists is ruleset number 0;
264 since the latter may not be modified, we have to create another ruleset
266 Note that since most of the following examples do not specify
268 the operations are performed on
270 (this only matters for things that might change the properties of nodes).
272 .Dl "devfs ruleset 10"
274 Specify that ruleset 10 should be the current ruleset for
276 (if it does not already exist, it is created).
278 .Dl "devfs rule add path speaker mode 666"
280 Add a rule that causes all nodes that have a path that matches
284 to have the file mode 666 (read and write for all).
285 Note that if any such nodes already exist, their mode will not be changed
286 unless this rule (or ruleset) is explicitly applied (see below).
289 be changed if the node is created
294 module is loaded after the above rule is added).
296 .Dl "devfs rule applyset"
298 Apply all the rules in the current ruleset to all the existing nodes.
299 E.g., if the above rule was added after
302 this command will cause its file mode to be changed to 666
303 as prescribed by the rule.
305 .Dl devfs rule add path "snp*" mode 660 group snoopers
307 (Quoting the argument to
309 is often necessary to disable the shell's globbing features.)
310 For all devices with a path that matches
312 set the file mode to 660 and the GID to
314 This permits users in the
320 .Dl "devfs rule -s 20 add type disk group wheel"
322 Add a rule to ruleset number 20.
323 Since this ruleset is not the current ruleset for any mount-points,
324 this rule is never applied automatically (unless ruleset 20 becomes
325 a current ruleset for some mount-point at a later time).
326 However, it can be applied explicitly, as such:
328 .Dl "devfs -m /my/jail/dev rule -s 20 applyset"
330 This will apply all rules in ruleset number 20 to the DEVFS mount on
332 It does not matter that ruleset 20 is not the current ruleset for that
333 mount-point; the rules are still applied.
335 .Dl "devfs rule apply hide"
337 Since this rule has no conditions, the action
339 will be applied to all nodes.
340 Since hiding all nodes is not very useful, we can undo it:
342 .Dl "devfs rule apply unhide"
347 causing them to reappear.
349 .Dl "devfs rule -s 10 add - < my_rules"
351 Add all the rules from the file
355 .Dl "devfs rule -s 20 show | devfs rule -s 10 add -"
360 this feature can be used to copy rulesets.
361 The above copies all the rules from ruleset 20 into ruleset 10.
362 The rule numbers are preserved,
363 but ruleset 10 may already have rules with non-conflicting numbers
364 (these will be preserved).
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