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[NETD-BPF#22] Move a few headers to frameworks/libs/net am: d568947cd7 am: d428cdb532 am: b6adf11ce6

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Original change: https://android-review.googlesource.com/c/platform/system/bpf/+/1928474

Change-Id: I4f09ab5b62c3b8d5a38d4d6d7b1cb8a851b3e51a
This commit is contained in:
Ken Chen 2021-12-23 17:38:26 +00:00 committed by Automerger Merge Worker
commit df41916a11
3 changed files with 1 additions and 394 deletions
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2
libbpf_android/Loader.cpp
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@ -33,8 +33,8 @@
#define BPFLOADER_VERSION_MINOR 8u
#define BPFLOADER_VERSION ((BPFLOADER_VERSION_MAJOR << 16) | BPFLOADER_VERSION_MINOR)
#include "../progs/include/bpf_map_def.h"
#include "bpf/BpfUtils.h"
#include "bpf/bpf_map_def.h"
#include "include/libbpf_android.h"
#include <cstdlib>

216
progs/include/bpf_helpers.h
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@ -1,216 +0,0 @@
/* Common BPF helpers to be used by all BPF programs loaded by Android */
#include <linux/bpf.h>
#include <stdbool.h>
#include <stdint.h>
#include "bpf_map_def.h"
/******************************************************************************
* WARNING: CHANGES TO THIS FILE OUTSIDE OF AOSP/MASTER ARE LIKELY TO BREAK *
* DEVICE COMPATIBILITY WITH MAINLINE MODULES SHIPPING EBPF CODE. *
* *
* THIS WILL LIKELY RESULT IN BRICKED DEVICES AT SOME ARBITRARY FUTURE TIME *
* *
* THAT GOES ESPECIALLY FOR THE 'SECTION' 'LICENSE' AND 'CRITICAL' MACROS *
* *
* We strongly suggest that if you need changes to bpfloader functionality *
* you get your changes reviewed and accepted into aosp/master. *
* *
******************************************************************************/
/* For mainline module use, you can #define BPFLOADER_{MIN/MAX}_VER
* before #include "bpf_helpers.h" to change which bpfloaders will
* process the resulting .o file.
*
* While this will work outside of mainline too, there just is no point to
* using it when the .o and the bpfloader ship in sync with each other.
*/
#ifndef BPFLOADER_MIN_VER
#define BPFLOADER_MIN_VER DEFAULT_BPFLOADER_MIN_VER
#endif
#ifndef BPFLOADER_MAX_VER
#define BPFLOADER_MAX_VER DEFAULT_BPFLOADER_MAX_VER
#endif
/* place things in different elf sections */
#define SECTION(NAME) __attribute__((section(NAME), used))
/* Must be present in every program, example usage:
* LICENSE("GPL"); or LICENSE("Apache 2.0");
*
* We also take this opportunity to embed a bunch of other useful values in
* the resulting .o (This is to enable some limited forward compatibility
* with mainline module shipped ebpf programs)
*
* The bpfloader_{min/max}_ver defines the [min, max) range of bpfloader
* versions that should load this .o file (bpfloaders outside of this range
* will simply ignore/skip this *entire* .o)
* The [inclusive,exclusive) matches what we do for kernel ver dependencies.
*
* The size_of_bpf_{map,prog}_def allow the bpfloader to load programs where
* these structures have been extended with additional fields (they will of
* course simply be ignored then).
*
* If missing, bpfloader_{min/max}_ver default to 0/0x10000 ie. [v0.0, v1.0),
* while size_of_bpf_{map/prog}_def default to 32/20 which are the v0.0 sizes.
*/
#define LICENSE(NAME) \
unsigned int _bpfloader_min_ver SECTION("bpfloader_min_ver") = BPFLOADER_MIN_VER; \
unsigned int _bpfloader_max_ver SECTION("bpfloader_max_ver") = BPFLOADER_MAX_VER; \
size_t _size_of_bpf_map_def SECTION("size_of_bpf_map_def") = sizeof(struct bpf_map_def); \
size_t _size_of_bpf_prog_def SECTION("size_of_bpf_prog_def") = sizeof(struct bpf_prog_def); \
char _license[] SECTION("license") = (NAME)
/* flag the resulting bpf .o file as critical to system functionality,
* loading all kernel version appropriate programs in it must succeed
* for bpfloader success
*/
#define CRITICAL(REASON) char _critical[] SECTION("critical") = (REASON)
/*
* Helper functions called from eBPF programs written in C. These are
* implemented in the kernel sources.
*/
#define KVER_NONE 0
#define KVER(a, b, c) (((a) << 24) + ((b) << 16) + (c))
#define KVER_INF 0xFFFFFFFFu
/* generic functions */
/*
* Type-unsafe bpf map functions - avoid if possible.
*
* Using these it is possible to pass in keys/values of the wrong type/size,
* or, for 'bpf_map_lookup_elem_unsafe' receive into a pointer to the wrong type.
* You will not get a compile time failure, and for certain types of errors you
* might not even get a failure from the kernel's ebpf verifier during program load,
* instead stuff might just not work right at runtime.
*
* Instead please use:
* DEFINE_BPF_MAP(foo_map, TYPE, KeyType, ValueType, num_entries)
* where TYPE can be something like HASH or ARRAY, and num_entries is an integer.
*
* This defines the map (hence this should not be used in a header file included
* from multiple locations) and provides type safe accessors:
* ValueType * bpf_foo_map_lookup_elem(const KeyType *)
* int bpf_foo_map_update_elem(const KeyType *, const ValueType *, flags)
* int bpf_foo_map_delete_elem(const KeyType *)
*
* This will make sure that if you change the type of a map you'll get compile
* errors at any spots you forget to update with the new type.
*
* Note: these all take pointers to const map because from the C/eBPF point of view
* the map struct is really just a readonly map definition of the in kernel object.
* Runtime modification of the map defining struct is meaningless, since
* the contents is only ever used during bpf program loading & map creation
* by the bpf loader, and not by the eBPF program itself.
*/
static void* (*bpf_map_lookup_elem_unsafe)(const struct bpf_map_def* map,
const void* key) = (void*)BPF_FUNC_map_lookup_elem;
static int (*bpf_map_update_elem_unsafe)(const struct bpf_map_def* map, const void* key,
const void* value, unsigned long long flags) = (void*)
BPF_FUNC_map_update_elem;
static int (*bpf_map_delete_elem_unsafe)(const struct bpf_map_def* map,
const void* key) = (void*)BPF_FUNC_map_delete_elem;
/* type safe macro to declare a map and related accessor functions */
#define DEFINE_BPF_MAP_UGM(the_map, TYPE, TypeOfKey, TypeOfValue, num_entries, usr, grp, md) \
const struct bpf_map_def SECTION("maps") the_map = { \
.type = BPF_MAP_TYPE_##TYPE, \
.key_size = sizeof(TypeOfKey), \
.value_size = sizeof(TypeOfValue), \
.max_entries = (num_entries), \
.map_flags = 0, \
.uid = (usr), \
.gid = (grp), \
.mode = (md), \
.bpfloader_min_ver = DEFAULT_BPFLOADER_MIN_VER, \
.bpfloader_max_ver = DEFAULT_BPFLOADER_MAX_VER, \
.min_kver = KVER_NONE, \
.max_kver = KVER_INF, \
}; \
\
static inline __always_inline __unused TypeOfValue* bpf_##the_map##_lookup_elem( \
const TypeOfKey* k) { \
return bpf_map_lookup_elem_unsafe(&the_map, k); \
}; \
\
static inline __always_inline __unused int bpf_##the_map##_update_elem( \
const TypeOfKey* k, const TypeOfValue* v, unsigned long long flags) { \
return bpf_map_update_elem_unsafe(&the_map, k, v, flags); \
}; \
\
static inline __always_inline __unused int bpf_##the_map##_delete_elem(const TypeOfKey* k) { \
return bpf_map_delete_elem_unsafe(&the_map, k); \
};
#define DEFINE_BPF_MAP(the_map, TYPE, TypeOfKey, TypeOfValue, num_entries) \
DEFINE_BPF_MAP_UGM(the_map, TYPE, TypeOfKey, TypeOfValue, num_entries, AID_ROOT, AID_ROOT, 0600)
#define DEFINE_BPF_MAP_GWO(the_map, TYPE, TypeOfKey, TypeOfValue, num_entries, gid) \
DEFINE_BPF_MAP_UGM(the_map, TYPE, TypeOfKey, TypeOfValue, num_entries, AID_ROOT, gid, 0620)
#define DEFINE_BPF_MAP_GRO(the_map, TYPE, TypeOfKey, TypeOfValue, num_entries, gid) \
DEFINE_BPF_MAP_UGM(the_map, TYPE, TypeOfKey, TypeOfValue, num_entries, AID_ROOT, gid, 0640)
#define DEFINE_BPF_MAP_GRW(the_map, TYPE, TypeOfKey, TypeOfValue, num_entries, gid) \
DEFINE_BPF_MAP_UGM(the_map, TYPE, TypeOfKey, TypeOfValue, num_entries, AID_ROOT, gid, 0660)
static int (*bpf_probe_read)(void* dst, int size, void* unsafe_ptr) = (void*) BPF_FUNC_probe_read;
static int (*bpf_probe_read_str)(void* dst, int size, void* unsafe_ptr) = (void*) BPF_FUNC_probe_read_str;
static unsigned long long (*bpf_ktime_get_ns)(void) = (void*) BPF_FUNC_ktime_get_ns;
static unsigned long long (*bpf_ktime_get_boot_ns)(void) = (void*)BPF_FUNC_ktime_get_boot_ns;
static int (*bpf_trace_printk)(const char* fmt, int fmt_size, ...) = (void*) BPF_FUNC_trace_printk;
static unsigned long long (*bpf_get_current_pid_tgid)(void) = (void*) BPF_FUNC_get_current_pid_tgid;
static unsigned long long (*bpf_get_current_uid_gid)(void) = (void*) BPF_FUNC_get_current_uid_gid;
static unsigned long long (*bpf_get_smp_processor_id)(void) = (void*) BPF_FUNC_get_smp_processor_id;
#define DEFINE_BPF_PROG_KVER_RANGE_OPT(SECTION_NAME, prog_uid, prog_gid, the_prog, min_kv, max_kv, \
opt) \
const struct bpf_prog_def SECTION("progs") the_prog##_def = { \
.uid = (prog_uid), \
.gid = (prog_gid), \
.min_kver = (min_kv), \
.max_kver = (max_kv), \
.optional = (opt), \
.bpfloader_min_ver = DEFAULT_BPFLOADER_MIN_VER, \
.bpfloader_max_ver = DEFAULT_BPFLOADER_MAX_VER, \
}; \
SECTION(SECTION_NAME) \
int the_prog
// Programs (here used in the sense of functions/sections) marked optional are allowed to fail
// to load (for example due to missing kernel patches).
// The bpfloader will just ignore these failures and continue processing the next section.
//
// A non-optional program (function/section) failing to load causes a failure and aborts
// processing of the entire .o, if the .o is additionally marked critical, this will result
// in the entire bpfloader process terminating with a failure and not setting the bpf.progs_loaded
// system property. This in turn results in waitForProgsLoaded() never finishing.
//
// ie. a non-optional program in a critical .o is mandatory for kernels matching the min/max kver.
// programs requiring a kernel version >= min_kv && < max_kv
#define DEFINE_BPF_PROG_KVER_RANGE(SECTION_NAME, prog_uid, prog_gid, the_prog, min_kv, max_kv) \
DEFINE_BPF_PROG_KVER_RANGE_OPT(SECTION_NAME, prog_uid, prog_gid, the_prog, min_kv, max_kv, \
false)
#define DEFINE_OPTIONAL_BPF_PROG_KVER_RANGE(SECTION_NAME, prog_uid, prog_gid, the_prog, min_kv, \
max_kv) \
DEFINE_BPF_PROG_KVER_RANGE_OPT(SECTION_NAME, prog_uid, prog_gid, the_prog, min_kv, max_kv, true)
// programs requiring a kernel version >= min_kv
#define DEFINE_BPF_PROG_KVER(SECTION_NAME, prog_uid, prog_gid, the_prog, min_kv) \
DEFINE_BPF_PROG_KVER_RANGE_OPT(SECTION_NAME, prog_uid, prog_gid, the_prog, min_kv, KVER_INF, \
false)
#define DEFINE_OPTIONAL_BPF_PROG_KVER(SECTION_NAME, prog_uid, prog_gid, the_prog, min_kv) \
DEFINE_BPF_PROG_KVER_RANGE_OPT(SECTION_NAME, prog_uid, prog_gid, the_prog, min_kv, KVER_INF, \
true)
// programs with no kernel version requirements
#define DEFINE_BPF_PROG(SECTION_NAME, prog_uid, prog_gid, the_prog) \
DEFINE_BPF_PROG_KVER_RANGE_OPT(SECTION_NAME, prog_uid, prog_gid, the_prog, 0, KVER_INF, false)
#define DEFINE_OPTIONAL_BPF_PROG(SECTION_NAME, prog_uid, prog_gid, the_prog) \
DEFINE_BPF_PROG_KVER_RANGE_OPT(SECTION_NAME, prog_uid, prog_gid, the_prog, 0, KVER_INF, true)

177
progs/include/bpf_map_def.h
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@ -1,177 +0,0 @@
/*
* Copyright (C) 2020 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
/* This file is separate because it's included both by eBPF programs (via include
* in bpf_helpers.h) and directly by the boot time bpfloader (Loader.cpp).
*/
#include <linux/bpf.h>
// Pull in AID_* constants from //system/core/libcutils/include/private/android_filesystem_config.h
#include <private/android_filesystem_config.h>
/******************************************************************************
* *
* ! ! ! W A R N I N G ! ! ! *
* *
* CHANGES TO THESE STRUCTURE DEFINITIONS OUTSIDE OF AOSP/MASTER *WILL* BREAK *
* MAINLINE MODULE COMPATIBILITY *
* *
* AND THUS MAY RESULT IN YOUR DEVICE BRICKING AT SOME ARBITRARY POINT IN *
* THE FUTURE *
* *
* (and even in aosp/master you may only append new fields at the very end, *
* you may *never* delete fields, change their types, ordering, insert in *
* the middle, etc. If a mainline module using the old definition has *
* already shipped (which happens roughly monthly), then it's set in stone) *
* *
******************************************************************************/
// These are the values used if these fields are missing
#define DEFAULT_BPFLOADER_MIN_VER 0u // v0.0 (this is inclusive ie. >= v0.0)
#define DEFAULT_BPFLOADER_MAX_VER 0x10000u // v1.0 (this is exclusive ie. < v1.0)
#define DEFAULT_SIZEOF_BPF_MAP_DEF 32 // v0.0 struct: enum (uint sized) + 7 uint
#define DEFAULT_SIZEOF_BPF_PROG_DEF 20 // v0.0 struct: 4 uint + bool + 3 byte alignment pad
/*
* The bpf_{map,prog}_def structures are compiled for different architectures.
* Once by the BPF compiler for the BPF architecture, and once by a C++
* compiler for the native Android architecture for the bpfloader.
*
* For things to work, their layout must be the same between the two.
* The BPF architecture is platform independent ('64-bit LSB bpf').
* So this effectively means these structures must be the same layout
* on 5 architectures, all of them little endian:
* 64-bit BPF, x86_64, arm and 32-bit x86 and arm
*
* As such for any types we use inside of these structs we must make sure that
* the size and alignment are the same, so the same amount of padding is used.
*
* Currently we only use: bool, enum bpf_map_type and unsigned int.
* Additionally we use char for padding.
*
* !!! WARNING: HERE BE DRAGONS !!!
*
* Be particularly careful with 64-bit integers.
* You will need to manually override their alignment to 8 bytes.
*
* To quote some parts of https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69560
*
* Some types have weaker alignment requirements when they are structure members.
*
* unsigned long long on x86 is such a type.
*
* C distinguishes C11 _Alignof (the minimum alignment the type is guaranteed
* to have in all contexts, so 4, see min_align_of_type) from GNU C __alignof
* (the normal alignment of the type, so 8).
*
* alignof / _Alignof == minimum alignment required by target ABI
* __alignof / __alignof__ == preferred alignment
*
* When in a struct, apparently the minimum alignment is used.
*/
_Static_assert(sizeof(bool) == 1, "sizeof bool != 1");
_Static_assert(__alignof__(bool) == 1, "__alignof__ bool != 1");
_Static_assert(_Alignof(bool) == 1, "_Alignof bool != 1");
_Static_assert(sizeof(char) == 1, "sizeof char != 1");
_Static_assert(__alignof__(char) == 1, "__alignof__ char != 1");
_Static_assert(_Alignof(char) == 1, "_Alignof char != 1");
// This basically verifies that an enum is 'just' a 32-bit int
_Static_assert(sizeof(enum bpf_map_type) == 4, "sizeof enum bpf_map_type != 4");
_Static_assert(__alignof__(enum bpf_map_type) == 4, "__alignof__ enum bpf_map_type != 4");
_Static_assert(_Alignof(enum bpf_map_type) == 4, "_Alignof enum bpf_map_type != 4");
// Linux kernel requires sizeof(int) == 4, sizeof(void*) == sizeof(long), sizeof(long long) == 8
_Static_assert(sizeof(unsigned int) == 4, "sizeof unsigned int != 4");
_Static_assert(__alignof__(unsigned int) == 4, "__alignof__ unsigned int != 4");
_Static_assert(_Alignof(unsigned int) == 4, "_Alignof unsigned int != 4");
// We don't currently use any 64-bit types in these structs, so this is purely to document issue.
// Here sizeof & __alignof__ are consistent, but _Alignof is not: compile for 'aosp_cf_x86_phone'
_Static_assert(sizeof(unsigned long long) == 8, "sizeof unsigned long long != 8");
_Static_assert(__alignof__(unsigned long long) == 8, "__alignof__ unsigned long long != 8");
// BPF wants 8, but 32-bit x86 wants 4
//_Static_assert(_Alignof(unsigned long long) == 8, "_Alignof unsigned long long != 8");
/*
* Map structure to be used by Android eBPF C programs. The Android eBPF loader
* uses this structure from eBPF object to create maps at boot time.
*
* The eBPF C program should define structure in the maps section using
* SECTION("maps") otherwise it will be ignored by the eBPF loader.
*
* For example:
* const struct bpf_map_def SECTION("maps") mymap { .type=... , .key_size=... }
*
* See 'bpf_helpers.h' for helpful macros for eBPF program use.
*/
struct bpf_map_def {
enum bpf_map_type type;
unsigned int key_size;
unsigned int value_size;
unsigned int max_entries;
unsigned int map_flags;
// The following are not supported by the Android bpfloader:
// unsigned int inner_map_idx;
// unsigned int numa_node;
unsigned int uid; // uid_t
unsigned int gid; // gid_t
unsigned int mode; // mode_t
// The following fields were added in version 0.1
unsigned int bpfloader_min_ver; // if missing, defaults to 0, ie. v0.0
unsigned int bpfloader_max_ver; // if missing, defaults to 0x10000, ie. v1.0
// The following fields were added in version 0.2
// kernelVersion() must be >= min_kver and < max_kver
unsigned int min_kver;
unsigned int max_kver;
};
// This needs to be updated whenever the above structure definition is expanded.
_Static_assert(sizeof(struct bpf_map_def) == 48, "sizeof struct bpf_map_def != 48");
_Static_assert(__alignof__(struct bpf_map_def) == 4, "__alignof__ struct bpf_map_def != 4");
_Static_assert(_Alignof(struct bpf_map_def) == 4, "_Alignof struct bpf_map_def != 4");
struct bpf_prog_def {
unsigned int uid;
unsigned int gid;
// kernelVersion() must be >= min_kver and < max_kver
unsigned int min_kver;
unsigned int max_kver;
bool optional; // program section (ie. function) may fail to load, continue onto next func.
char pad0[3];
// The following fields were added in version 0.1
unsigned int bpfloader_min_ver; // if missing, defaults to 0, ie. v0.0
unsigned int bpfloader_max_ver; // if missing, defaults to 0x10000, ie. v1.0
// No new fields in version 0.2
};
// This needs to be updated whenever the above structure definition is expanded.
_Static_assert(sizeof(struct bpf_prog_def) == 28, "sizeof struct bpf_prog_def != 28");
_Static_assert(__alignof__(struct bpf_prog_def) == 4, "__alignof__ struct bpf_prog_def != 4");
_Static_assert(_Alignof(struct bpf_prog_def) == 4, "_Alignof struct bpf_prog_def != 4");