From ac505f97f1e85d95c9fe2b0401a375c2c8cd1cb9 Mon Sep 17 00:00:00 2001 From: Josh Stone Date: Wed, 16 Sep 2009 15:52:17 -0700 Subject: Add the badname.stp example This is a toy script I wrote a while back to demonstrate how SystemTap could be used to enforce filesystem naming rules. --- testsuite/systemtap.examples/general/badname.meta | 13 +++++++++++ testsuite/systemtap.examples/general/badname.stp | 28 +++++++++++++++++++++++ testsuite/systemtap.examples/index.html | 3 +++ testsuite/systemtap.examples/index.txt | 7 ++++++ testsuite/systemtap.examples/keyword-index.html | 14 +++++++++++- testsuite/systemtap.examples/keyword-index.txt | 18 +++++++++++++++ 6 files changed, 82 insertions(+), 1 deletion(-) create mode 100644 testsuite/systemtap.examples/general/badname.meta create mode 100755 testsuite/systemtap.examples/general/badname.stp (limited to 'testsuite/systemtap.examples') diff --git a/testsuite/systemtap.examples/general/badname.meta b/testsuite/systemtap.examples/general/badname.meta new file mode 100644 index 00000000..9b4e7390 --- /dev/null +++ b/testsuite/systemtap.examples/general/badname.meta @@ -0,0 +1,13 @@ +title: Bad Filename Filter +name: badname.stp +version: 1.0 +keywords: filesystem hack +author: Josh Stone +subsystem: filesystem +status: experimental +exit: user-controlled +output: none +scope: system-wide +description: The badname.stp script shows how one could prevent the creation of files with undesirable names. +test_check: stap -p4 badname.stp +test_installcheck: stap badname.stp -c "sleep 0.2" diff --git a/testsuite/systemtap.examples/general/badname.stp b/testsuite/systemtap.examples/general/badname.stp new file mode 100755 index 00000000..153e08c5 --- /dev/null +++ b/testsuite/systemtap.examples/general/badname.stp @@ -0,0 +1,28 @@ +#!/usr/bin/stap -g +# badname.stp +# Prevent the creation of files with undesirable names. +# Source: http://blog.cuviper.com/2009/04/08/hacking-linux-filenames/ + +# return non-zero if the filename should be blocked +function filter:long (name:string) +{ + return euid() && isinstr(name, "XXX") +} + +global squash_inode_permission +probe kernel.function("may_create@fs/namei.c") +{ + # screen out the conditions which may_create will fail anyway + if ($child->d_inode || $dir->i_flags & 16) next + + # check that the new file meets our naming rules + if (filter(kernel_string($child->d_name->name))) + squash_inode_permission[tid()] = 1 +} +probe kernel.function("inode_permission@fs/namei.c").return !, + kernel.function("permission@fs/namei.c").return +{ + if (!$return && squash_inode_permission[tid()]) + $return = -13 # -EACCES (Permission denied) + delete squash_inode_permission[tid()] +} diff --git a/testsuite/systemtap.examples/index.html b/testsuite/systemtap.examples/index.html index 203bc5d4..cd2faadb 100644 --- a/testsuite/systemtap.examples/index.html +++ b/testsuite/systemtap.examples/index.html @@ -46,6 +46,9 @@ keywords: FORMAT
  • general/ansi_colors2.stp - Show Attribues in Table for ansi_set_color3()
    keywords: FORMAT

    The script prints a table showing the available attributes (bold, underline, and inverse) with color combinations for the ans_set_color3() function in the ansi.stp tapset.

    • +
  • general/badname.stp - Bad Filename Filter
    +keywords: FILESYSTEM HACK
    +

    The badname.stp script shows how one could prevent the creation of files with undesirable names.

  • general/graphs.stp - Graphing Disk and CPU Utilization
    keywords: DISK CPU USE GRAPH

    The script tracks the disk and CPU utilization. The resulting output of the script can be piped into gnuplot to generate a graph of disk and CPU USE.

    • diff --git a/testsuite/systemtap.examples/index.txt b/testsuite/systemtap.examples/index.txt index 20b4da4f..2e096ab1 100644 --- a/testsuite/systemtap.examples/index.txt +++ b/testsuite/systemtap.examples/index.txt @@ -17,6 +17,13 @@ keywords: format ans_set_color3() function in the ansi.stp tapset. +general/badname.stp - Bad Filename Filter +keywords: filesystem hack + + The badname.stp script shows how one could prevent the creation of + files with undesirable names. + + general/graphs.stp - Graphing Disk and CPU Utilization keywords: disk cpu use graph diff --git a/testsuite/systemtap.examples/keyword-index.html b/testsuite/systemtap.examples/keyword-index.html index b59ce4a8..fe8fcc4e 100644 --- a/testsuite/systemtap.examples/keyword-index.html +++ b/testsuite/systemtap.examples/keyword-index.html @@ -39,7 +39,7 @@

    Examples by Keyword

    -

    AUTOFS BACKTRACE BUFFER CALLGRAPH CPU DEVICE DISK FORMAT FREE FUNCTIONS FUTEX GRAPH INTERRUPT IO LOCKING MEMORY MONITOR NETWORK NFS NUMA PER-PROCESS PROCESS PROFILING READ SCHEDULER SCSI SIGNALS SIMPLE SLEEP SOCKET STATISTICS SYSCALL TCP TIME TRACE TRACEPOINT TRAFFIC TTY USE WAIT4 WRITE

    +

    AUTOFS BACKTRACE BUFFER CALLGRAPH CPU DEVICE DISK FILESYSTEM FORMAT FREE FUNCTIONS FUTEX GRAPH HACK INTERRUPT IO LOCKING MEMORY MONITOR NETWORK NFS NUMA PER-PROCESS PROCESS PROFILING READ SCHEDULER SCSI SIGNALS SIMPLE SLEEP SOCKET STATISTICS SYSCALL TCP TIME TRACE TRACEPOINT TRAFFIC TTY USE WAIT4 WRITE

    AUTOFS

    +

    FILESYSTEM

    +

    FORMAT

    +

    HACK

    +

    INTERRUPT