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/*
* Copyright (c) 2019 Facebook, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <linux/version.h>
#include <unistd.h>
#include <string>
#include "BPF.h"
#include "catch.hpp"
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
TEST_CASE("test hash of maps", "[hash_of_maps]") {
{
const std::string BPF_PROGRAM = R"(
BPF_ARRAY(cntl, int, 1);
BPF_ARRAY(ex1, int, 1024);
BPF_ARRAY(ex2, int, 1024);
BPF_ARRAY(ex3, u64, 1024);
BPF_HASH_OF_MAPS(maps_hash, int, "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 == 1 : lookup and update
cntl_val = *val;
inner_map = maps_hash.lookup(&key);
if (!inner_map)
return 0;
if (cntl_val == 1) {
val = bpf_map_lookup_elem(inner_map, &key);
if (val) {
data = 1;
bpf_map_update_elem(inner_map, &key, &data, 0);
}
}
return 0;
}
)";
ebpf::BPF bpf;
ebpf::StatusTuple res(0);
res = bpf.init(BPF_PROGRAM);
REQUIRE(res.ok());
auto t = bpf.get_map_in_map_table<int>("maps_hash");
auto ex1_table = bpf.get_array_table<int>("ex1");
auto ex2_table = bpf.get_array_table<int>("ex2");
auto ex3_table = bpf.get_array_table<unsigned long long>("ex3");
int ex1_fd = ex1_table.get_fd();
int ex2_fd = ex2_table.get_fd();
int ex3_fd = ex3_table.get_fd();
int key = 0, value = 0;
res = t.update_value(key, ex1_fd);
REQUIRE(res.ok());
// updating already-occupied slot will succeed.
res = t.update_value(key, ex2_fd);
REQUIRE(res.ok());
res = t.update_value(key, ex1_fd);
REQUIRE(res.ok());
// an in-compatible map
key = 1;
res = t.update_value(key, ex3_fd);
REQUIRE(res.code() == -1);
// hash table, any valid key should work as long
// as hash table is not full.
key = 10;
res = t.update_value(key, ex2_fd);
REQUIRE(res.ok());
res = t.remove_value(key);
REQUIRE(res.ok());
// test effectiveness of map-in-map
key = 0;
std::string getuid_fnname = bpf.get_syscall_fnname("getuid");
res = bpf.attach_kprobe(getuid_fnname, "syscall__getuid");
REQUIRE(res.ok());
auto cntl_table = bpf.get_array_table<int>("cntl");
cntl_table.update_value(0, 1);
REQUIRE(getuid() >= 0);
res = ex1_table.get_value(key, value);
REQUIRE(res.ok());
REQUIRE(value > 0);
res = bpf.detach_kprobe(getuid_fnname);
REQUIRE(res.ok());
res = t.remove_value(key);
REQUIRE(res.ok());
}
}
TEST_CASE("test hash of maps using custom key", "[hash_of_maps_custom_key]") {
{
const std::string BPF_PROGRAM = R"(
struct custom_key {
int value_1;
int value_2;
};
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, struct custom_key, "ex1", 10);
int syscall__getuid(void *ctx) {
struct custom_key hash_key = {1, 0};
int key = 0, data, *val, cntl_val;
void *inner_map;
val = cntl.lookup(&key);
if (!val || *val == 0)
return 0;
hash_key.value_2 = *val;
inner_map = maps_hash.lookup(&hash_key);
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;
}
)";
struct custom_key {
int value_1;
int value_2;
};
ebpf::BPF bpf;
ebpf::StatusTuple res(0);
res = bpf.init(BPF_PROGRAM);
REQUIRE(res.ok());
auto t = bpf.get_map_in_map_table<struct custom_key>("maps_hash");
auto ex1_table = bpf.get_hash_table<int, int>("ex1");
auto ex2_table = bpf.get_hash_table<int, int>("ex2");
auto cntl_table = bpf.get_array_table<int>("cntl");
int ex1_fd = ex1_table.get_fd();
int ex2_fd = ex2_table.get_fd();
// test effectiveness of map-in-map
std::string getuid_fnname = bpf.get_syscall_fnname("getuid");
res = bpf.attach_kprobe(getuid_fnname, "syscall__getuid");
REQUIRE(res.ok());
struct custom_key hash_key = {1, 1};
res = t.update_value(hash_key, ex1_fd);
REQUIRE(res.ok());
struct custom_key hash_key2 = {1, 2};
res = t.update_value(hash_key2, ex2_fd);
REQUIRE(res.ok());
int key = 0, value = 0, value2 = 0;
// Can't get value when value didn't set.
res = ex1_table.get_value(key, value);
REQUIRE(!res.ok());
REQUIRE(value == 0);
// Call syscall__getuid, then set value to ex1_table
res = cntl_table.update_value(key, 1);
REQUIRE(res.ok());
REQUIRE(getuid() >= 0);
// Now we can get value from ex1_table
res = ex1_table.get_value(key, value);
REQUIRE(res.ok());
REQUIRE(value >= 1);
// Can't get value when value didn't set.
res = ex2_table.get_value(key, value2);
REQUIRE(!res.ok());
REQUIRE(value2 == 0);
// Call syscall__getuid, then set value to ex2_table
res = cntl_table.update_value(key, 2);
REQUIRE(res.ok());
REQUIRE(getuid() >= 0);
// Now we can get value from ex2_table
res = ex2_table.get_value(key, value2);
REQUIRE(res.ok());
REQUIRE(value > 0);
res = bpf.detach_kprobe(getuid_fnname);
REQUIRE(res.ok());
res = t.remove_value(hash_key);
REQUIRE(res.ok());
res = t.remove_value(hash_key2);
REQUIRE(res.ok());
}
}
TEST_CASE("test array of maps", "[array_of_maps]") {
{
const std::string BPF_PROGRAM = R"(
BPF_ARRAY(cntl, int, 1);
BPF_TABLE("hash", int, int, ex1, 1024);
BPF_TABLE("hash", int, int, ex2, 1024);
BPF_TABLE("hash", u64, u64, ex3, 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 == 1 : lookup and update
// cntl_val == 2 : delete
cntl_val = *val;
inner_map = maps_array.lookup(&key);
if (!inner_map)
return 0;
if (cntl_val == 1) {
val = bpf_map_lookup_elem(inner_map, &key);
if (!val) {
data = 1;
bpf_map_update_elem(inner_map, &key, &data, 0);
}
} else if (cntl_val == 2) {
bpf_map_delete_elem(inner_map, &key);
}
return 0;
}
)";
ebpf::BPF bpf;
ebpf::StatusTuple res(0);
res = bpf.init(BPF_PROGRAM);
REQUIRE(res.ok());
auto t = bpf.get_map_in_map_table<int>("maps_array");
auto ex1_table = bpf.get_hash_table<int, int>("ex1");
auto ex2_table = bpf.get_hash_table<int, int>("ex2");
auto ex3_table =
bpf.get_hash_table<unsigned long long, unsigned long long>("ex3");
int ex1_fd = ex1_table.get_fd();
int ex2_fd = ex2_table.get_fd();
int ex3_fd = ex3_table.get_fd();
int key = 0, value = 0;
res = t.update_value(key, ex1_fd);
REQUIRE(res.ok());
// updating already-occupied slot will succeed.
res = t.update_value(key, ex2_fd);
REQUIRE(res.ok());
res = t.update_value(key, ex1_fd);
REQUIRE(res.ok());
// an in-compatible map
key = 1;
res = t.update_value(key, ex3_fd);
REQUIRE(res.code() == -1);
// array table, out of bound access
key = 10;
res = t.update_value(key, ex2_fd);
REQUIRE(res.code() == -1);
// test effectiveness of map-in-map
key = 0;
std::string getuid_fnname = bpf.get_syscall_fnname("getuid");
res = bpf.attach_kprobe(getuid_fnname, "syscall__getuid");
REQUIRE(res.ok());
auto cntl_table = bpf.get_array_table<int>("cntl");
cntl_table.update_value(0, 1);
REQUIRE(getuid() >= 0);
res = ex1_table.get_value(key, value);
REQUIRE(res.ok());
REQUIRE(value == 1);
cntl_table.update_value(0, 2);
REQUIRE(getuid() >= 0);
res = ex1_table.get_value(key, value);
REQUIRE(res.code() == -1);
res = bpf.detach_kprobe(getuid_fnname);
REQUIRE(res.ok());
res = t.remove_value(key);
REQUIRE(res.ok());
}
}
#endif
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