1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
|
[[!meta copyright="Copyright © 2011 Free Software Foundation, Inc."]]
[[!meta license="""[[!toggle id="license" text="GFDL 1.2+"]][[!toggleable
id="license" text="Permission is granted to copy, distribute and/or modify this
document under the terms of the GNU Free Documentation License, Version 1.2 or
any later version published by the Free Software Foundation; with no Invariant
Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license
is included in the section entitled [[GNU Free Documentation
License|/fdl]]."]]"""]]
[[!tag open_issue_documentation]]
IRC, freenode, #hurd, 2011-10-31:
<pinotree> is there some example of translator replying to custom ioctl's?
<pinotree> let's say you define some ioctl (those which can be represented)
using the _IOW etc macros; how would a translator (or something else)
"register" and reply to them?
<youpi> it's not an easy thing
<youpi> see hurd/hurd/tioctl.defs for instance
<youpi> that's where the 't' ioctls end up
<youpi> ('t' being the group in the _IOW macro)
<braunr> it's not that hard either
<pinotree> youpi: so you "roll" the ioctl to an ipc call with proper
parameters?
<braunr> yes
<pinotree> ah ok, i thought there was some way to hook new ioctl's, and
have libc send the whole stuff at once
<braunr> and the proper number (with a clear name)
<braunr> hm
<braunr> for many ioctls, you don't have to change libc
<youpi> yes, there's a script which produces the .defs from _IOW calls,
iirc
<youpi> or something like this
<youpi> there's also a hook thing in glibc, but for "sane" ioctls, that's
not needed
<youpi> (_hurd_lookup_ioctl_handler called by ioctl())
<youpi> yes, see the rules in hurd/hurd/Makefile
<youpi> "The following rules assist in creating an `Xioctl.defs' file to
define RPCs that are sent primarily by ioctl commands."
<antrik> well, you can have perfectly sane ioctl()s that still can't be
expressed within the constraints of the IO* macros... but admittedly
that's rather uncommon
<antrik> (unless you consider passing of structs generally insane...)
<youpi> I didn't want to spend time on finding an appropriate adjective
instaed of "sane"
<youpi> while I knew he would understand what I meant (and you did)
<youpi> (though maybe not actually)
<youpi> by "sane", I mean, which use _IOW properly
<youpi> i.e. with a group, proper numbers, etc.
<youpi> (the imposed contraints on the parameters is obviously a flaw in
the hurdish ioctl design, and not insanity from structures)
|