Sams Teach Yourself Samba in 24 Hours		ContentsIndex
Hour 10: Server-Side Automation		Previous HourNext Hour
Sections in this Chapter: What Is Server-Side Automation? %d preexec and postexec Scripts Summary %U and %u, %G and %g Q&A %L, %m, and the include Parameters New Terms		Previous SectionNext Section

%d

I have included this last section in hopes that it will inspire your own creativity. One thing that can be difficult is determining which smbd processes are associated with which users. Hour 4, "Installing and Testing the Configuration," explains how to determine this information by using the smbstatus tool. In this section, I'm going to show you how to use root preexec and postexec scripts to implement the capability to kill all smbd processes that are running in the context of a particular user. The system comprises three basic parts:

• The root preexec and root postexec commands specified in the smb.conf file.



• The directory containing the output files from the root preexec and root postexec scripts.



• The shell script that actually kills the processes.

I'll examine each component one at a time. First, I'll examine the root preexec and root postexec commands. I want to associate a process ID with a username. This information is available in the %d and %U smb.conf variables respectively. The root preexec command creates a file with the name of the process ID for the connection and contains only the username sent by the client:

[apps]
     comment = global shared drive
     root preexec = echo %U > /usr/local/samba/lib/proc/%d
     root postexec = /bin/rm /usr/local/samba/lib/proc/%d
     path = /export/smb/apps

The assumption here is that every client connects to the [apps] share in addition to any other service. This is an easy assumption to work around if you check for the existence of /usr/local/samba/lib/proc/%d before attempting to create it. For now, assume that all clients connect to the [apps] share.

After the files are created, you can create a simple script to grep for the user's login name in the files. The located files will be the process IDs of the associated smbds.

#!/bin/sh
# set     the path
PATH=/usr/bin:/bin
export PATH
# set the location for the pid files
SMBD_DIR=/usr/local/samba/lib/proc
# the username should be passed as the single command line parameter
if [ "$1" eq "" ]; then
   echo `Usage : killsmbd <username>'
else
   username=$1
fi
for pid in `grep $username $SMBD_DIR/*`; do
   echo "Killing $pid"
   kill -9 $pid

done

If you want to kill all the smbd processes for the user jdoe, you can simply type

killsmbd jdoe

You can design a similar system to enable you to terminate smbd processes based on the connected machine name by creating files that contain the %m variable.

Sams Teach Yourself Samba in 24 Hours		ContentsIndex
Hour 10: Server-Side Automation		Previous HourNext Hour
Sections in this Chapter: What Is Server-Side Automation? %d preexec and postexec Scripts Summary %U and %u, %G and %g Q&A %L, %m, and the include Parameters New Terms		Previous SectionNext Section

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