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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 Hiding a directory node effectively hides all of its child nodes.
194 .It Cm include Ar ruleset
195 Apply all the rules in ruleset number
198 This does not necessarily result in any changes to the node
199 (e.g., if none of the rules in the included ruleset match).
200 Include commands in the referenced
203 .It Cm mode Ar filemode
206 which is interpreted as in
211 which may be a user name
217 If the node resides in a subdirectory,
218 all parent directory nodes must be visible to be able to access the node.
220 .Sh IMPLEMENTATION NOTES
221 Rulesets are created by the kernel at the first reference
222 and destroyed when the last reference disappears.
223 E.g., a ruleset is created when a rule is added to it or when it is set
224 as the current ruleset for a mount-point, and
225 a ruleset is destroyed when the last rule in it is deleted
226 and no other references to it exist
227 (i.e., it is not included by any rules and it is not the current ruleset
228 for any mount-point).
230 Ruleset number 0 is the default ruleset for all new mount-points.
231 It is always empty, cannot be modified or deleted, and does not show up
235 Rules and rulesets are unique to the entire system,
236 not a particular mount-point.
239 will return the same information regardless of the mount-point specified with
241 The mount-point is only relevant when changing what its current ruleset is
242 or when using one of the apply commands.
245 .It Pa /etc/defaults/devfs.rules
249 .It Pa /etc/devfs.rules
252 configuration file. Rulesets in here override those in
253 .Pa /etc/defaults/devfs.rules
254 with the same ruleset number, otherwise the two files are effectively merged.
255 .It Pa /etc/devfs.conf
259 .It Pa /usr/share/examples/etc/devfs.conf
265 When the system boots,
266 the only ruleset that exists is ruleset number 0;
267 since the latter may not be modified, we have to create another ruleset
269 Note that since most of the following examples do not specify
271 the operations are performed on
273 (this only matters for things that might change the properties of nodes).
275 .Dl "devfs ruleset 10"
277 Specify that ruleset 10 should be the current ruleset for
279 (if it does not already exist, it is created).
281 .Dl "devfs rule add path speaker mode 666"
283 Add a rule that causes all nodes that have a path that matches
287 to have the file mode 666 (read and write for all).
288 Note that if any such nodes already exist, their mode will not be changed
289 unless this rule (or ruleset) is explicitly applied (see below).
292 be changed if the node is created
297 module is loaded after the above rule is added).
299 .Dl "devfs rule applyset"
301 Apply all the rules in the current ruleset to all the existing nodes.
302 E.g., if the above rule was added after
305 this command will cause its file mode to be changed to 666
306 as prescribed by the rule.
308 .Dl devfs rule add path "snp*" mode 660 group snoopers
310 (Quoting the argument to
312 is often necessary to disable the shell's globbing features.)
313 For all devices with a path that matches
315 set the file mode to 660 and the GID to
317 This permits users in the
323 .Dl "devfs rule -s 20 add type disk group wheel"
325 Add a rule to ruleset number 20.
326 Since this ruleset is not the current ruleset for any mount-points,
327 this rule is never applied automatically (unless ruleset 20 becomes
328 a current ruleset for some mount-point at a later time).
329 However, it can be applied explicitly, as such:
331 .Dl "devfs -m /my/jail/dev rule -s 20 applyset"
333 This will apply all rules in ruleset number 20 to the DEVFS mount on
335 It does not matter that ruleset 20 is not the current ruleset for that
336 mount-point; the rules are still applied.
338 .Dl "devfs rule apply hide"
340 Since this rule has no conditions, the action
342 will be applied to all nodes.
343 Since hiding all nodes is not very useful, we can undo it:
345 .Dl "devfs rule apply unhide"
350 causing them to reappear.
352 .Dl "devfs rule -s 10 add - < my_rules"
354 Add all the rules from the file
358 .Dl "devfs rule -s 20 show | devfs rule -s 10 add -"
363 this feature can be used to copy rulesets.
364 The above copies all the rules from ruleset 20 into ruleset 10.
365 The rule numbers are preserved,
366 but ruleset 10 may already have rules with non-conflicting numbers
367 (these will be preserved).
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