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/*
* Copyright 2016, The Android Open Source Project
*
* 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 <nativehelper/JNIHelp.h>
#include <nativehelper/ScopedUtfChars.h>
#include <jni.h>
#include <pcap.h>
#include <stdlib.h>
#include <string>
#include <utils/Log.h>
#include "apf_interpreter.h"
#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
// JNI function acting as simply call-through to native APF interpreter.
static jint com_android_server_ApfTest_apfSimulate(
JNIEnv* env, jclass, jbyteArray program, jbyteArray packet, jint filter_age) {
return accept_packet(
(uint8_t*)env->GetByteArrayElements(program, NULL),
env->GetArrayLength(program),
(uint8_t*)env->GetByteArrayElements(packet, NULL),
env->GetArrayLength(packet),
nullptr,
0,
filter_age);
}
class ScopedPcap {
public:
explicit ScopedPcap(pcap_t* pcap) : pcap_ptr(pcap) {}
~ScopedPcap() {
pcap_close(pcap_ptr);
}
pcap_t* get() const { return pcap_ptr; };
private:
pcap_t* const pcap_ptr;
};
class ScopedFILE {
public:
explicit ScopedFILE(FILE* fp) : file(fp) {}
~ScopedFILE() {
fclose(file);
}
FILE* get() const { return file; };
private:
FILE* const file;
};
static void throwException(JNIEnv* env, const std::string& error) {
jclass newExcCls = env->FindClass("java/lang/IllegalStateException");
if (newExcCls == 0) {
abort();
return;
}
env->ThrowNew(newExcCls, error.c_str());
}
static jstring com_android_server_ApfTest_compileToBpf(JNIEnv* env, jclass, jstring jfilter) {
ScopedUtfChars filter(env, jfilter);
std::string bpf_string;
ScopedPcap pcap(pcap_open_dead(DLT_EN10MB, 65535));
if (pcap.get() == NULL) {
throwException(env, "pcap_open_dead failed");
return NULL;
}
// Compile "filter" to a BPF program
bpf_program bpf;
if (pcap_compile(pcap.get(), &bpf, filter.c_str(), 0, PCAP_NETMASK_UNKNOWN)) {
throwException(env, "pcap_compile failed");
return NULL;
}
// Translate BPF program to human-readable format
const struct bpf_insn* insn = bpf.bf_insns;
for (uint32_t i = 0; i < bpf.bf_len; i++) {
bpf_string += bpf_image(insn++, i);
bpf_string += "\n";
}
return env->NewStringUTF(bpf_string.c_str());
}
static jboolean com_android_server_ApfTest_compareBpfApf(JNIEnv* env, jclass, jstring jfilter,
jstring jpcap_filename, jbyteArray japf_program) {
ScopedUtfChars filter(env, jfilter);
ScopedUtfChars pcap_filename(env, jpcap_filename);
const uint8_t* apf_program = (uint8_t*)env->GetByteArrayElements(japf_program, NULL);
const uint32_t apf_program_len = env->GetArrayLength(japf_program);
// Open pcap file for BPF filtering
ScopedFILE bpf_fp(fopen(pcap_filename.c_str(), "rb"));
char pcap_error[PCAP_ERRBUF_SIZE];
ScopedPcap bpf_pcap(pcap_fopen_offline(bpf_fp.get(), pcap_error));
if (bpf_pcap.get() == NULL) {
throwException(env, "pcap_fopen_offline failed: " + std::string(pcap_error));
return false;
}
// Open pcap file for APF filtering
ScopedFILE apf_fp(fopen(pcap_filename.c_str(), "rb"));
ScopedPcap apf_pcap(pcap_fopen_offline(apf_fp.get(), pcap_error));
if (apf_pcap.get() == NULL) {
throwException(env, "pcap_fopen_offline failed: " + std::string(pcap_error));
return false;
}
// Compile "filter" to a BPF program
bpf_program bpf;
if (pcap_compile(bpf_pcap.get(), &bpf, filter.c_str(), 0, PCAP_NETMASK_UNKNOWN)) {
throwException(env, "pcap_compile failed");
return false;
}
// Install BPF filter on bpf_pcap
if (pcap_setfilter(bpf_pcap.get(), &bpf)) {
throwException(env, "pcap_setfilter failed");
return false;
}
while (1) {
pcap_pkthdr bpf_header, apf_header;
// Run BPF filter to the next matching packet.
const uint8_t* bpf_packet = pcap_next(bpf_pcap.get(), &bpf_header);
// Run APF filter to the next matching packet.
const uint8_t* apf_packet;
do {
apf_packet = pcap_next(apf_pcap.get(), &apf_header);
} while (apf_packet != NULL && !accept_packet(
apf_program, apf_program_len, apf_packet, apf_header.len,
nullptr, 0, 0));
// Make sure both filters matched the same packet.
if (apf_packet == NULL && bpf_packet == NULL)
break;
if (apf_packet == NULL || bpf_packet == NULL)
return false;
if (apf_header.len != bpf_header.len ||
apf_header.ts.tv_sec != bpf_header.ts.tv_sec ||
apf_header.ts.tv_usec != bpf_header.ts.tv_usec ||
memcmp(apf_packet, bpf_packet, apf_header.len))
return false;
}
return true;
}
extern "C" jint JNI_OnLoad(JavaVM* vm, void*) {
JNIEnv *env;
if (vm->GetEnv(reinterpret_cast<void**>(&env), JNI_VERSION_1_6) != JNI_OK) {
ALOGE("ERROR: GetEnv failed");
return -1;
}
static JNINativeMethod gMethods[] = {
{ "apfSimulate", "([B[BI)I",
(void*)com_android_server_ApfTest_apfSimulate },
{ "compileToBpf", "(Ljava/lang/String;)Ljava/lang/String;",
(void*)com_android_server_ApfTest_compileToBpf },
{ "compareBpfApf", "(Ljava/lang/String;Ljava/lang/String;[B)Z",
(void*)com_android_server_ApfTest_compareBpfApf },
};
jniRegisterNativeMethods(env, "android/net/apf/ApfTest",
gMethods, ARRAY_SIZE(gMethods));
return JNI_VERSION_1_6;
}
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