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[NETD-BPF#14] Move BPF map definition and utils to frameworks/libs/net/ am: b1d4888ec2 am: 18af063372

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Original change: https://android-review.googlesource.com/c/platform/system/bpf/+/1869329

Change-Id: I64f1bd06f39157921b3fee08e18ed65eb770e65f
This commit is contained in:
Ken Chen 2021-12-04 13:47:08 +00:00 committed by Automerger Merge Worker
commit 8e2e81b87f
6 changed files with 10 additions and 443 deletions
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1
bpfloader/Android.bp
View file

@ -39,6 +39,7 @@ cc_binary {
memtag_heap: true,
},
clang: true,
header_libs: ["bpf_map_utils"],
shared_libs: [
"libcutils",
"libbpf_android",

9
libbpf_android/Android.bp
View file

@ -61,9 +61,13 @@ cc_library {
"libbpf",
],
header_libs: [
"libbpf_android_headers"
"bpf_map_utils",
"libbpf_android_headers",
],
export_header_lib_headers: [
"libbpf_android_headers",
"bpf_map_utils",
],
export_header_lib_headers: ["libbpf_android_headers"],
export_shared_lib_headers: ["libbpf"],
local_include_dirs: ["include"],
@ -77,6 +81,7 @@ cc_library {
cc_test {
name: "libbpf_load_test",
header_libs: ["bpf_map_utils"],
srcs: [
"BpfLoadTest.cpp",
],

4
libbpf_android/BpfLoadTest.cpp
View file

@ -19,8 +19,8 @@
#include <stdlib.h>
#include <unistd.h>
#include <iostream>
#include "include/bpf/BpfMap.h"
#include "include/bpf/BpfUtils.h"
#include "bpf/BpfMap.h"
#include "bpf/BpfUtils.h"
#include "include/libbpf_android.h"
using ::testing::Test;

39
libbpf_android/include/WaitForProgsLoaded.h
View file

@ -1,39 +0,0 @@
/*
* Copyright (C) 2021 The Android Open Source Project
* Android BPF library - public API
*
* 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.
*/
#pragma once
#include <log/log.h>
#include <android-base/properties.h>
namespace android {
namespace bpf {
// Wait for bpfloader to load BPF programs.
static inline void waitForProgsLoaded() {
// infinite loop until success with 5/10/20/40/60/60/60... delay
for (int delay = 5;; delay *= 2) {
if (delay > 60) delay = 60;
if (android::base::WaitForProperty("bpf.progs_loaded", "1", std::chrono::seconds(delay)))
return;
ALOGW("Waited %ds for bpf.progs_loaded, still waiting...", delay);
}
}
} // namespace bpf
} // namespace android

260
libbpf_android/include/bpf/BpfMap.h
View file

@ -1,260 +0,0 @@
/*
* Copyright (C) 2018 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.
*/
#pragma once
#include <linux/bpf.h>
#include <android-base/result.h>
#include <android-base/stringprintf.h>
#include <android-base/unique_fd.h>
#include <utils/Log.h>
#include "bpf/BpfUtils.h"
namespace android {
namespace bpf {
// This is a class wrapper for eBPF maps. The eBPF map is a special in-kernel
// data structure that stores data in <Key, Value> pairs. It can be read/write
// from userspace by passing syscalls with the map file descriptor. This class
// is used to generalize the procedure of interacting with eBPF maps and hide
// the implementation detail from other process. Besides the basic syscalls
// wrapper, it also provides some useful helper functions as well as an iterator
// nested class to iterate the map more easily.
//
// NOTE: A kernel eBPF map may be accessed by both kernel and userspace
// processes at the same time. Or if the map is pinned as a virtual file, it can
// be obtained by multiple eBPF map class object and accessed concurrently.
// Though the map class object and the underlying kernel map are thread safe, it
// is not safe to iterate over a map while another thread or process is deleting
// from it. In this case the iteration can return duplicate entries.
template <class Key, class Value>
class BpfMap {
public:
BpfMap<Key, Value>() {};
protected:
// flag must be within BPF_OBJ_FLAG_MASK, ie. 0, BPF_F_RDONLY, BPF_F_WRONLY
BpfMap<Key, Value>(const char* pathname, uint32_t flags) {
int map_fd = mapRetrieve(pathname, flags);
if (map_fd >= 0) mMapFd.reset(map_fd);
}
public:
explicit BpfMap<Key, Value>(const char* pathname) : BpfMap<Key, Value>(pathname, 0) {}
BpfMap<Key, Value>(bpf_map_type map_type, uint32_t max_entries, uint32_t map_flags = 0) {
int map_fd = createMap(map_type, sizeof(Key), sizeof(Value), max_entries, map_flags);
if (map_fd >= 0) mMapFd.reset(map_fd);
}
base::Result<Key> getFirstKey() const {
Key firstKey;
if (getFirstMapKey(mMapFd, &firstKey)) {
return ErrnoErrorf("Get firstKey map {} failed", mMapFd.get());
}
return firstKey;
}
base::Result<Key> getNextKey(const Key& key) const {
Key nextKey;
if (getNextMapKey(mMapFd, &key, &nextKey)) {
return ErrnoErrorf("Get next key of map {} failed", mMapFd.get());
}
return nextKey;
}
base::Result<void> writeValue(const Key& key, const Value& value, uint64_t flags) {
if (writeToMapEntry(mMapFd, &key, &value, flags)) {
return ErrnoErrorf("Write to map {} failed", mMapFd.get());
}
return {};
}
base::Result<Value> readValue(const Key key) const {
Value value;
if (findMapEntry(mMapFd, &key, &value)) {
return ErrnoErrorf("Read value of map {} failed", mMapFd.get());
}
return value;
}
base::Result<void> deleteValue(const Key& key) {
if (deleteMapEntry(mMapFd, &key)) {
return ErrnoErrorf("Delete entry from map {} failed", mMapFd.get());
}
return {};
}
// Function that tries to get map from a pinned path.
base::Result<void> init(const char* path);
// Iterate through the map and handle each key retrieved based on the filter
// without modification of map content.
base::Result<void> iterate(
const std::function<base::Result<void>(const Key& key, const BpfMap<Key, Value>& map)>&
filter) const;
// Iterate through the map and get each <key, value> pair, handle each <key,
// value> pair based on the filter without modification of map content.
base::Result<void> iterateWithValue(
const std::function<base::Result<void>(const Key& key, const Value& value,
const BpfMap<Key, Value>& map)>& filter) const;
// Iterate through the map and handle each key retrieved based on the filter
base::Result<void> iterate(
const std::function<base::Result<void>(const Key& key, BpfMap<Key, Value>& map)>&
filter);
// Iterate through the map and get each <key, value> pair, handle each <key,
// value> pair based on the filter.
base::Result<void> iterateWithValue(
const std::function<base::Result<void>(const Key& key, const Value& value,
BpfMap<Key, Value>& map)>& filter);
const base::unique_fd& getMap() const { return mMapFd; };
// Copy assignment operator
BpfMap<Key, Value>& operator=(const BpfMap<Key, Value>& other) {
if (this != &other) mMapFd.reset(fcntl(other.mMapFd.get(), F_DUPFD_CLOEXEC, 0));
return *this;
}
// Move assignment operator
BpfMap<Key, Value>& operator=(BpfMap<Key, Value>&& other) noexcept {
mMapFd = std::move(other.mMapFd);
other.reset(-1);
return *this;
}
void reset(base::unique_fd fd) = delete;
void reset(int fd) { mMapFd.reset(fd); }
bool isValid() const { return mMapFd != -1; }
base::Result<void> clear() {
while (true) {
auto key = getFirstKey();
if (!key.ok()) {
if (key.error().code() == ENOENT) return {}; // empty: success
return key.error(); // Anything else is an error
}
auto res = deleteValue(key.value());
if (!res.ok()) {
// Someone else could have deleted the key, so ignore ENOENT
if (res.error().code() == ENOENT) continue;
ALOGE("Failed to delete data %s", strerror(res.error().code()));
return res.error();
}
}
}
base::Result<bool> isEmpty() const {
auto key = getFirstKey();
if (!key.ok()) {
// Return error code ENOENT means the map is empty
if (key.error().code() == ENOENT) return true;
return key.error();
}
return false;
}
private:
base::unique_fd mMapFd;
};
template <class Key, class Value>
base::Result<void> BpfMap<Key, Value>::init(const char* path) {
mMapFd = base::unique_fd(mapRetrieveRW(path));
if (mMapFd == -1) {
return ErrnoErrorf("Pinned map not accessible or does not exist: ({})", path);
}
return {};
}
template <class Key, class Value>
base::Result<void> BpfMap<Key, Value>::iterate(
const std::function<base::Result<void>(const Key& key, const BpfMap<Key, Value>& map)>&
filter) const {
base::Result<Key> curKey = getFirstKey();
while (curKey.ok()) {
const base::Result<Key>& nextKey = getNextKey(curKey.value());
base::Result<void> status = filter(curKey.value(), *this);
if (!status.ok()) return status;
curKey = nextKey;
}
if (curKey.error().code() == ENOENT) return {};
return curKey.error();
}
template <class Key, class Value>
base::Result<void> BpfMap<Key, Value>::iterateWithValue(
const std::function<base::Result<void>(const Key& key, const Value& value,
const BpfMap<Key, Value>& map)>& filter) const {
base::Result<Key> curKey = getFirstKey();
while (curKey.ok()) {
const base::Result<Key>& nextKey = getNextKey(curKey.value());
base::Result<Value> curValue = readValue(curKey.value());
if (!curValue.ok()) return curValue.error();
base::Result<void> status = filter(curKey.value(), curValue.value(), *this);
if (!status.ok()) return status;
curKey = nextKey;
}
if (curKey.error().code() == ENOENT) return {};
return curKey.error();
}
template <class Key, class Value>
base::Result<void> BpfMap<Key, Value>::iterate(
const std::function<base::Result<void>(const Key& key, BpfMap<Key, Value>& map)>& filter) {
base::Result<Key> curKey = getFirstKey();
while (curKey.ok()) {
const base::Result<Key>& nextKey = getNextKey(curKey.value());
base::Result<void> status = filter(curKey.value(), *this);
if (!status.ok()) return status;
curKey = nextKey;
}
if (curKey.error().code() == ENOENT) return {};
return curKey.error();
}
template <class Key, class Value>
base::Result<void> BpfMap<Key, Value>::iterateWithValue(
const std::function<base::Result<void>(const Key& key, const Value& value,
BpfMap<Key, Value>& map)>& filter) {
base::Result<Key> curKey = getFirstKey();
while (curKey.ok()) {
const base::Result<Key>& nextKey = getNextKey(curKey.value());
base::Result<Value> curValue = readValue(curKey.value());
if (!curValue.ok()) return curValue.error();
base::Result<void> status = filter(curKey.value(), curValue.value(), *this);
if (!status.ok()) return status;
curKey = nextKey;
}
if (curKey.error().code() == ENOENT) return {};
return curKey.error();
}
template <class Key, class Value>
class BpfMapRO : public BpfMap<Key, Value> {
public:
explicit BpfMapRO<Key, Value>(const char* pathname)
: BpfMap<Key, Value>(pathname, BPF_F_RDONLY) {}
};
} // namespace bpf
} // namespace android

140
libbpf_android/include/bpf/BpfUtils.h
View file

@ -1,140 +0,0 @@
/*
* 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.
*/
#pragma once
#include <linux/if_ether.h>
#include <linux/pfkeyv2.h>
#include <net/if.h>
#include <stdlib.h>
#include <string.h>
#include <sys/resource.h>
#include <sys/socket.h>
#include <sys/utsname.h>
#include <string>
#include <android-base/unique_fd.h>
#include <log/log.h>
#include "BpfSyscallWrappers.h"
// The buffer size for the buffer that records program loading logs, needs to be large enough for
// the largest kernel program.
namespace android {
namespace bpf {
constexpr const int OVERFLOW_COUNTERSET = 2;
constexpr const uint64_t NONEXISTENT_COOKIE = 0;
static inline uint64_t getSocketCookie(int sockFd) {
uint64_t sock_cookie;
socklen_t cookie_len = sizeof(sock_cookie);
int res = getsockopt(sockFd, SOL_SOCKET, SO_COOKIE, &sock_cookie, &cookie_len);
if (res < 0) {
res = -errno;
ALOGE("Failed to get socket cookie: %s\n", strerror(errno));
errno = -res;
// 0 is an invalid cookie. See sock_gen_cookie.
return NONEXISTENT_COOKIE;
}
return sock_cookie;
}
static inline int synchronizeKernelRCU() {
// This is a temporary hack for network stats map swap on devices running
// 4.9 kernels. The kernel code of socket release on pf_key socket will
// explicitly call synchronize_rcu() which is exactly what we need.
int pfSocket = socket(AF_KEY, SOCK_RAW | SOCK_CLOEXEC, PF_KEY_V2);
if (pfSocket < 0) {
int ret = -errno;
ALOGE("create PF_KEY socket failed: %s", strerror(errno));
return ret;
}
// When closing socket, synchronize_rcu() gets called in sock_release().
if (close(pfSocket)) {
int ret = -errno;
ALOGE("failed to close the PF_KEY socket: %s", strerror(errno));
return ret;
}
return 0;
}
static inline int setrlimitForTest() {
// Set the memory rlimit for the test process if the default MEMLOCK rlimit is not enough.
struct rlimit limit = {
.rlim_cur = 1073741824, // 1 GiB
.rlim_max = 1073741824, // 1 GiB
};
int res = setrlimit(RLIMIT_MEMLOCK, &limit);
if (res) {
ALOGE("Failed to set the default MEMLOCK rlimit: %s", strerror(errno));
}
return res;
}
#define KVER(a, b, c) (((a) << 24) + ((b) << 16) + (c))
static inline unsigned kernelVersion() {
struct utsname buf;
int ret = uname(&buf);
if (ret) return 0;
unsigned kver_major;
unsigned kver_minor;
unsigned kver_sub;
char unused;
ret = sscanf(buf.release, "%u.%u.%u%c", &kver_major, &kver_minor, &kver_sub, &unused);
// Check the device kernel version
if (ret < 3) return 0;
return KVER(kver_major, kver_minor, kver_sub);
}
static inline bool isAtLeastKernelVersion(unsigned major, unsigned minor, unsigned sub) {
return kernelVersion() >= KVER(major, minor, sub);
}
#define SKIP_IF_BPF_SUPPORTED \
do { \
if (android::bpf::isAtLeastKernelVersion(4, 9, 0)) \
GTEST_SKIP() << "Skip: bpf is supported."; \
} while (0)
#define SKIP_IF_BPF_NOT_SUPPORTED \
do { \
if (!android::bpf::isAtLeastKernelVersion(4, 9, 0)) \
GTEST_SKIP() << "Skip: bpf is not supported."; \
} while (0)
#define SKIP_IF_EXTENDED_BPF_NOT_SUPPORTED \
do { \
if (!android::bpf::isAtLeastKernelVersion(4, 14, 0)) \
GTEST_SKIP() << "Skip: extended bpf feature not supported."; \
} while (0)
#define SKIP_IF_XDP_NOT_SUPPORTED \
do { \
if (!android::bpf::isAtLeastKernelVersion(5, 9, 0)) \
GTEST_SKIP() << "Skip: xdp not supported."; \
} while (0)
} // namespace bpf
} // namespace android