[NETD-BPF#23] 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: Ie6f257b022cdea6bab3389a9fa41791f893e54c3
diff --git a/staticlibs/native/bpf_headers/include/bpf/bpf_helpers.h b/staticlibs/native/bpf_headers/include/bpf/bpf_helpers.h
new file mode 100644
index 0000000..878bb10
--- /dev/null
+++ b/staticlibs/native/bpf_headers/include/bpf/bpf_helpers.h
@@ -0,0 +1,216 @@
+/* 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)
diff --git a/staticlibs/native/bpf_headers/include/bpf/bpf_map_def.h b/staticlibs/native/bpf_headers/include/bpf/bpf_map_def.h
new file mode 100644
index 0000000..02b2096
--- /dev/null
+++ b/staticlibs/native/bpf_headers/include/bpf/bpf_map_def.h
@@ -0,0 +1,177 @@
+/*
+ * 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");