kern/183615: linprocfs: emulate /proc/sys/kernel/random/uuid

[Florian Heigl]

>Number:         183615
>Category:       kern
>Synopsis:       linprocfs: emulate /proc/sys/kernel/random/uuid
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Sun Nov 03 13:10:00 UTC 2013
>Closed-Date:
>Last-Modified:
>Originator:     Florian Heigl
>Release:        9.1-STABLE#0
>Organization:
>Environment:
FreeBSD freebsd1 9.1-STABLE FreeBSD 9.1-STABLE #0: Sun Jul  7 23:12:23 EEST 2013     root at freebsd:/usr/obj/usr/src/sys/XENHVM  amd64
FreeBSD freebsd1 9.1-STABLE FreeBSD 9.1-STABLE #0: Sun Jul  7 23:12:23 EEST 2013     root at freebsd:/usr/obj/usr/src/sys/XENHVM  amd64

>Description:
I followed (somewhat) the debian document about setting up a Debian Jail on FreeBSD at https://wiki.debian.org/Debian_GNU/kFreeBSD/Jails

Using the Linux module and mounting some filesystems I have this working OK and can ssh into it. With this, I'm trying to make some software available to FreeBSD.

linprocfs          4       4        0   100%    /srv/jail/debjail/proc
linsysfs           4       4        0   100%    /srv/jail/debjail/sys
tmpfs          36068      60    36008     0%    /srv/jail/debjail/run
devfs              1       1        0   100%    /srv/jail/debjail/dev
linprocfs          4       4        0   100%    /usr/compat/linux/proc

A problem I hit is that some application (in this case: Check_MK multisite) uses the procfs to gain easy access to uuid's for session handling and object id's.

What they do is: 
root at debjail:/omd/sites/freemon# grep -R "random/uuid" *
share/check_mk/web/htdocs/weblib.py:        sel_id = file('/proc/sys/kernel/random/uuid').read().strip()



In linprocfs we don't have this file available, or actually the whole directory ain't there:
builder at debjail:/build$ ls /proc/sys/kernel/
msgmni  osrelease  ostype  pid_max  sem  version


The following things are in there on Linux:
$ ls /proc/sys/kernel/random
boot_id        poolsize               uuid
entropy_avail  read_wakeup_threshold  write_wakeup_threshold

Could anyone look into this? 
in case of "uuid" it seems there's a FreeBSD system call that gives back an uuid.


Myself I'll try and see if i can create a pipe or something in that place that gives back a uuid on read?
>How-To-Repeat:
mount linux procfs, check for existance of /proc/sys/kernel/random/uuid

should be accessible like this:
$ cat /proc/sys/kernel/random/uuid 
bee78388-ce08-450a-be12-dcbbc6c4f3f1

(but isn't since we don't got it)
>Fix:


>Release-Note:
>Audit-Trail:
>Unformatted: