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|
#!/bin/sh
# Test getting and setting of capabilities using getcap(8) and setcap(8).
# a simple test program. Assumes AUTOPKGTEST_TMP is set, see
# /usr/share/doc/autopkgtest/README.package-tests.gz
set -e
echo "@@@ Running test for getcap/setcap... @@@"
#########
# Preconditions
#########
if [ `id -u` -ne 0 ]
then
echo "This test must be run as root" >&2
exit 1
elif [ -z "$AUTOPKGTEST_TMP" ]
then
echo "This test requires that \$AUTOPKGTEST_TMP be set" >&2
exit 1
fi
# We will mount a tmpfs within AUTOPKGTEST_TMP. This is the only way to be sure that we
# are on a filesystem mounted without the nosuid option
test_tmpfs="$AUTOPKGTEST_TMP/tmpfs_executables"
# Make sure that we undo all our changes to the system
cleanup_testenv() {
cd /
if mountpoint -q "$test_tmpfs"
then
umount "$test_tmpfs"
fi
rmdir "$test_tmpfs"
}
trap cleanup_testenv EXIT HUP INT QUIT TERM
#########
# Set some names. We are modifying capabilities, so paths should be absolute.
#########
testuser=nobody
testfile="$test_tmpfs/testfile"
testprog="$test_tmpfs/chown_testfile"
testprog_src="${testprog}.c"
#########
# Step 1: Mount out tmpfs, and cd to it
#########
mkdir -p "$test_tmpfs"
mount -t tmpfs -o size=10m tmpfs "$test_tmpfs"
cd "$tmpfs"
#########
# Step 2: Prepare a trivial program that changes permissions of file $testfile
#########
cat > "$testprog_src" <<EOF
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <unistd.h>
int main(int argc, char **argv)
{
/* See if we can chown the given file */
if (chown("$testfile", getuid(), getgid()) != 0) {
perror("chown");
exit(EXIT_FAILURE);
}
printf("OK\n");
exit(EXIT_SUCCESS);
}
EOF
gcc -Wall -o "$testprog" "$testprog_src"
chmod 755 "$testprog"
#########
# Step 3: Ceate a file with root ownership
#########
touch "$testfile"
#########
# Step 4: Verify that our test program fails to chown the file due to
# insufficient permissions
#########
echo "Attempt to chown *without* CAP_CHOWN should fail:"
if su -c "$testprog" -s /bin/sh nobody 2>&1
then
echo "Test file chown was successful although it shouldn't have been" >&2
exit 1
else
echo "OK, failed"
fi
#########
# Step 5: Set CAP_CHOWN and ensure that our test program succeeds this time
#########
echo "Set CAP_CHOWN on test file:"
if ! setcap cap_chown+ep "$testprog" 2>&1
then
echo "Failed to set CAP_CHOWN on $testprog" >&2
exit 1
elif ! setcap -v cap_chown+ep "$testprog" 2>&1
then
echo "Setting CAP_CHOWN on $testprog succeeded but verification failed" >&2
exit 1
else
echo "OK, set"
fi
echo "Attempt to chown *with* CAP_CHOWN should succeed:"
if ! su -c "$testprog" -s /bin/sh nobody 2>&1
then
echo "Test file chown failed although it shouldn't have" >&2
exit 1
else
echo "OK, chown succeeded"
fi
#########
# Step 6:
# Final verification
#########
if [ `stat -c '%u:%g' "$testfile"` != "`id -u $testuser`:`id -g $testuser`" ]
then
echo "chown succeeded but resulting ownership doesn't match expecation" >&2
exit 1
fi
# End of test
echo "@@@ Test: OK @@@"
|
