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/*
* Copyright (C) 2017 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.
*/
#ifndef LOG_TAG
#define LOG_TAG "bpfloader"
#endif
#include <arpa/inet.h>
#include <dirent.h>
#include <elf.h>
#include <error.h>
#include <fcntl.h>
#include <inttypes.h>
#include <linux/bpf.h>
#include <linux/unistd.h>
#include <net/if.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <android-base/properties.h>
#include <android-base/stringprintf.h>
#include <android-base/strings.h>
#include <android-base/unique_fd.h>
#include <libbpf_android.h>
#include <log/log.h>
#include <netdutils/Misc.h>
#include <netdutils/Slice.h>
#include "bpf/BpfUtils.h"
using android::base::EndsWith;
using std::string;
struct {
const char* const dir;
const char* const prefix;
} locations[] = {
// Tethering mainline module
{
.dir = "/apex/com.android.tethering/etc/bpf/",
.prefix = "tethering/",
},
// Core operating system
{
.dir = "/system/etc/bpf/",
.prefix = "",
},
};
int loadAllElfObjects(const char* const progDir, const char* const prefix) {
int retVal = 0;
DIR* dir;
struct dirent* ent;
if ((dir = opendir(progDir)) != NULL) {
while ((ent = readdir(dir)) != NULL) {
string s = ent->d_name;
if (!EndsWith(s, ".o")) continue;
string progPath(progDir);
progPath += s;
bool critical;
int ret = android::bpf::loadProg(progPath.c_str(), &critical, prefix);
if (ret) {
if (critical) retVal = ret;
ALOGE("Failed to load object: %s, ret: %s", progPath.c_str(), std::strerror(-ret));
} else {
ALOGI("Loaded object: %s", progPath.c_str());
}
}
closedir(dir);
}
return retVal;
}
void createSysFsBpfSubDir(const char* const prefix) {
if (*prefix) {
mode_t prevUmask = umask(0);
string s = "/sys/fs/bpf/";
s += prefix;
errno = 0;
int ret = mkdir(s.c_str(), S_ISVTX | S_IRWXU | S_IRWXG | S_IRWXO);
if (ret && errno != EEXIST) {
ALOGW("Failed to create directory: %s, ret: %s", s.c_str(), std::strerror(errno));
}
umask(prevUmask);
}
}
int main() {
bool ebpf_supported = android::base::GetBoolProperty("ro.kernel.ebpf.supported", true);
if (ebpf_supported) {
// Load all ELF objects, create programs and maps, and pin them
for (const auto location : locations) {
createSysFsBpfSubDir(location.prefix);
if (loadAllElfObjects(location.dir, location.prefix) != 0) {
ALOGE("=== CRITICAL FAILURE LOADING BPF PROGRAMS FROM %s ===", location.dir);
ALOGE("If this triggers reliably, you're probably missing kernel options "
"or patches.");
ALOGE("If this triggers randomly, you might be hitting some memory allocation "
"problems or startup script race.");
ALOGE("--- DO NOT EXPECT SYSTEM TO BOOT SUCCESSFULLY ---");
sleep(20);
return 2;
}
}
}
if (android::base::SetProperty("bpf.progs_loaded", "1") == false) {
ALOGE("Failed to set bpf.progs_loaded property");
return 1;
}
return 0;
}
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