From d568947cd742e5eeb1c53edc8e3853a85ed66865 Mon Sep 17 00:00:00 2001 From: Ken Chen Date: Mon, 20 Dec 2021 18:07:21 +0800 Subject: [PATCH] [NETD-BPF#22] Move a few headers to frameworks/libs/net BPF headers used by both platform and mainline modules should be in frameworks/libs/net. Bug: 202086915 Test: build and boot Test: cd packages/modules/Connectivity/netd; atest Change-Id: Id9ac888d5519b2a8663232610d36386cabfe4e94 --- libbpf_android/Loader.cpp | 2 +- progs/include/bpf_helpers.h | 216 ------------------------------------ progs/include/bpf_map_def.h | 177 ----------------------------- 3 files changed, 1 insertion(+), 394 deletions(-) delete mode 100644 progs/include/bpf_helpers.h delete mode 100644 progs/include/bpf_map_def.h diff --git a/libbpf_android/Loader.cpp b/libbpf_android/Loader.cpp index 1892fe2..abe1704 100644 --- a/libbpf_android/Loader.cpp +++ b/libbpf_android/Loader.cpp @@ -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 diff --git a/progs/include/bpf_helpers.h b/progs/include/bpf_helpers.h deleted file mode 100644 index 878bb10..0000000 --- a/progs/include/bpf_helpers.h +++ /dev/null @@ -1,216 +0,0 @@ -/* Common BPF helpers to be used by all BPF programs loaded by Android */ - -#include -#include -#include - -#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) diff --git a/progs/include/bpf_map_def.h b/progs/include/bpf_map_def.h deleted file mode 100644 index 02b2096..0000000 --- a/progs/include/bpf_map_def.h +++ /dev/null @@ -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 - -// Pull in AID_* constants from //system/core/libcutils/include/private/android_filesystem_config.h -#include - -/****************************************************************************** - * * - * ! ! ! 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");