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#!/usr/bin/env python
#
# USAGE: test_map_in_map.py
#
# Copyright 2019 Facebook, Inc
# Licensed under the Apache License, Version 2.0 (the "License")
from __future__ import print_function
from bcc import BPF
import distutils.version
from unittest import main, skipUnless, TestCase
import ctypes as ct
import os
def kernel_version_ge(major, minor):
# True if running kernel is >= X.Y
version = distutils.version.LooseVersion(os.uname()[2]).version
if version[0] > major:
return True
if version[0] < major:
return False
if minor and version[1] < minor:
return False
return True
@skipUnless(kernel_version_ge(4,11), "requires kernel >= 4.11")
class TestUDST(TestCase):
def test_hash_table(self):
bpf_text = """
BPF_ARRAY(cntl, int, 1);
BPF_TABLE("hash", int, int, ex1, 1024);
BPF_TABLE("hash", int, int, ex2, 1024);
BPF_HASH_OF_MAPS(maps_hash, "ex1", 10);
int syscall__getuid(void *ctx) {
int key = 0, data, *val, cntl_val;
void *inner_map;
val = cntl.lookup(&key);
if (!val || *val == 0)
return 0;
cntl_val = *val;
inner_map = maps_hash.lookup(&cntl_val);
if (!inner_map)
return 0;
val = bpf_map_lookup_elem(inner_map, &key);
if (!val) {
data = 1;
bpf_map_update_elem(inner_map, &key, &data, 0);
} else {
data = 1 + *val;
bpf_map_update_elem(inner_map, &key, &data, 0);
}
return 0;
}
"""
b = BPF(text=bpf_text)
cntl_map = b.get_table("cntl")
ex1_map = b.get_table("ex1")
ex2_map = b.get_table("ex2")
hash_maps = b.get_table("maps_hash")
hash_maps[ct.c_int(1)] = ct.c_int(ex1_map.get_fd())
hash_maps[ct.c_int(2)] = ct.c_int(ex2_map.get_fd())
syscall_fnname = b.get_syscall_fnname("getuid")
b.attach_kprobe(event=syscall_fnname, fn_name="syscall__getuid")
try:
ex1_map[ct.c_int(0)]
raise Exception("Unexpected success for ex1_map[0]")
except KeyError:
pass
cntl_map[0] = ct.c_int(1)
os.getuid()
assert(ex1_map[ct.c_int(0)] >= 1)
try:
ex2_map[ct.c_int(0)]
raise Exception("Unexpected success for ex2_map[0]")
except KeyError:
pass
cntl_map[0] = ct.c_int(2)
os.getuid()
assert(ex2_map[ct.c_int(0)] >= 1)
b.detach_kprobe(event=syscall_fnname)
del hash_maps[ct.c_int(1)]
del hash_maps[ct.c_int(2)]
def test_array_table(self):
bpf_text = """
BPF_ARRAY(cntl, int, 1);
BPF_ARRAY(ex1, int, 1024);
BPF_ARRAY(ex2, int, 1024);
BPF_ARRAY_OF_MAPS(maps_array, "ex1", 10);
int syscall__getuid(void *ctx) {
int key = 0, data, *val, cntl_val;
void *inner_map;
val = cntl.lookup(&key);
if (!val || *val == 0)
return 0;
cntl_val = *val;
inner_map = maps_array.lookup(&cntl_val);
if (!inner_map)
return 0;
val = bpf_map_lookup_elem(inner_map, &key);
if (val) {
data = 1 + *val;
bpf_map_update_elem(inner_map, &key, &data, 0);
}
return 0;
}
"""
b = BPF(text=bpf_text)
cntl_map = b.get_table("cntl")
ex1_map = b.get_table("ex1")
ex2_map = b.get_table("ex2")
array_maps = b.get_table("maps_array")
array_maps[ct.c_int(1)] = ct.c_int(ex1_map.get_fd())
array_maps[ct.c_int(2)] = ct.c_int(ex2_map.get_fd())
syscall_fnname = b.get_syscall_fnname("getuid")
b.attach_kprobe(event=syscall_fnname, fn_name="syscall__getuid")
cntl_map[0] = ct.c_int(1)
os.getuid()
assert(ex1_map[ct.c_int(0)] >= 1)
cntl_map[0] = ct.c_int(2)
os.getuid()
assert(ex2_map[ct.c_int(0)] >= 1)
b.detach_kprobe(event=syscall_fnname)
if __name__ == "__main__":
main()
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